X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/5d5c5d0d5b79ade9a973d55186ffda2638ba2b6e..94ff46dc2849db4d43eaaf144872decc522aafb4:/iokit/Kernel/IOMemoryDescriptor.cpp

diff --git a/iokit/Kernel/IOMemoryDescriptor.cpp b/iokit/Kernel/IOMemoryDescriptor.cpp
index 0e1873b30..d73a4343b 100644
--- a/iokit/Kernel/IOMemoryDescriptor.cpp
+++ b/iokit/Kernel/IOMemoryDescriptor.cpp
@@ -1,39 +1,32 @@
 /*
- * Copyright (c) 1998-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1998-2016 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
- * 
- * This file contains Original Code and/or Modifications of Original Code 
- * as defined in and that are subject to the Apple Public Source License 
- * Version 2.0 (the 'License'). You may not use this file except in 
- * compliance with the License.  The rights granted to you under the 
- * License may not be used to create, or enable the creation or 
- * redistribution of, unlawful or unlicensed copies of an Apple operating 
- * system, or to circumvent, violate, or enable the circumvention or 
- * violation of, any terms of an Apple operating system software license 
- * agreement.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
- * Please obtain a copy of the License at 
- * http://www.opensource.apple.com/apsl/ and read it before using this 
- * file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  *
- * The Original Code and all software distributed under the License are 
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
- * Please see the License for the specific language governing rights and 
- * limitations under the License.
- *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
- */
-/*
- * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved. 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  *
- * HISTORY
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
-// 45678901234567890123456789012345678901234567890123456789012345678901234567890
+
+
 #include <sys/cdefs.h>
 
 #include <IOKit/assert.h>
@@ -41,75 +34,49 @@
 #include <IOKit/IOLib.h>
 #include <IOKit/IOMemoryDescriptor.h>
 #include <IOKit/IOMapper.h>
+#include <IOKit/IODMACommand.h>
 #include <IOKit/IOKitKeysPrivate.h>
 
+#include <IOKit/IOSubMemoryDescriptor.h>
+#include <IOKit/IOMultiMemoryDescriptor.h>
+
 #include <IOKit/IOKitDebug.h>
+#include <libkern/OSDebug.h>
+#include <libkern/OSKextLibPrivate.h>
 
 #include "IOKitKernelInternal.h"
-#include "IOCopyMapper.h"
 
 #include <libkern/c++/OSContainers.h>
 #include <libkern/c++/OSDictionary.h>
 #include <libkern/c++/OSArray.h>
 #include <libkern/c++/OSSymbol.h>
 #include <libkern/c++/OSNumber.h>
+#include <os/overflow.h>
 
 #include <sys/uio.h>
 
 __BEGIN_DECLS
 #include <vm/pmap.h>
 #include <vm/vm_pageout.h>
-#include <vm/vm_shared_memory_server.h>
 #include <mach/memory_object_types.h>
 #include <device/device_port.h>
 
 #include <mach/vm_prot.h>
+#include <mach/mach_vm.h>
+#include <mach/memory_entry.h>
 #include <vm/vm_fault.h>
+#include <vm/vm_protos.h>
 
 extern ppnum_t pmap_find_phys(pmap_t pmap, addr64_t va);
-void ipc_port_release_send(ipc_port_t port);
-
-/* Copy between a physical page and a virtual address in the given vm_map */
-kern_return_t copypv(addr64_t source, addr64_t sink, unsigned int size, int which);
-
-memory_object_t
-device_pager_setup(
-	memory_object_t	pager,
-	int		device_handle,
-	vm_size_t	size,
-	int		flags);
-void
-device_pager_deallocate(
-        memory_object_t);
-kern_return_t
-device_pager_populate_object(
-	memory_object_t		pager,
-	vm_object_offset_t	offset,
-	ppnum_t			phys_addr,
-	vm_size_t		size);
-kern_return_t
-memory_object_iopl_request(
-	ipc_port_t		port,
-	memory_object_offset_t	offset,
-	vm_size_t		*upl_size,
-	upl_t			*upl_ptr,
-	upl_page_info_array_t	user_page_list,
-	unsigned int		*page_list_count,
-	int			*flags);
-
-unsigned int  IOTranslateCacheBits(struct phys_entry *pp);
+extern void ipc_port_release_send(ipc_port_t port);
 
 __END_DECLS
 
-#define kIOMaximumMappedIOByteCount	(512*1024*1024)
+#define kIOMapperWaitSystem     ((IOMapper *) 1)
 
 static IOMapper * gIOSystemMapper = NULL;
 
-IOCopyMapper *	  gIOCopyMapper = NULL;
-
-static ppnum_t	  gIOMaximumMappedIOPageCount = atop_32(kIOMaximumMappedIOByteCount);
-
-ppnum_t		  gIOLastPage;
+ppnum_t           gIOLastPage;
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
@@ -123,1846 +90,3624 @@ OSDefineMetaClassAndStructors(IOGeneralMemoryDescriptor, IOMemoryDescriptor)
 
 static IORecursiveLock * gIOMemoryLock;
 
-#define LOCK	IORecursiveLockLock( gIOMemoryLock)
-#define UNLOCK	IORecursiveLockUnlock( gIOMemoryLock)
-#define SLEEP	IORecursiveLockSleep( gIOMemoryLock, (void *)this, THREAD_UNINT)
-#define WAKEUP	\
+#define LOCK    IORecursiveLockLock( gIOMemoryLock)
+#define UNLOCK  IORecursiveLockUnlock( gIOMemoryLock)
+#define SLEEP   IORecursiveLockSleep( gIOMemoryLock, (void *)this, THREAD_UNINT)
+#define WAKEUP  \
     IORecursiveLockWakeup( gIOMemoryLock, (void *)this, /* one-thread */ false)
 
 #if 0
-#define DEBG(fmt, args...)  	{ kprintf(fmt, ## args); }
+#define DEBG(fmt, args...)      { kprintf(fmt, ## args); }
 #else
-#define DEBG(fmt, args...)  	{}
+#define DEBG(fmt, args...)      {}
 #endif
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-class _IOMemoryMap : public IOMemoryMap
-{
-    OSDeclareDefaultStructors(_IOMemoryMap)
-public:
-    IOMemoryDescriptor * memory;
-    IOMemoryMap *	superMap;
-    IOByteCount		offset;
-    IOByteCount		length;
-    IOVirtualAddress	logical;
-    task_t		addressTask;
-    vm_map_t		addressMap;
-    IOOptionBits	options;
-    upl_t		redirUPL;
-    ipc_port_t		redirEntry;
-    IOMemoryDescriptor * owner;
-
-protected:
-    virtual void taggedRelease(const void *tag = 0) const;
-    virtual void free();
-
-public:
-
-    // IOMemoryMap methods
-    virtual IOVirtualAddress 	getVirtualAddress();
-    virtual IOByteCount 	getLength();
-    virtual task_t		getAddressTask();
-    virtual IOMemoryDescriptor * getMemoryDescriptor();
-    virtual IOOptionBits 	getMapOptions();
-
-    virtual IOReturn 		unmap();
-    virtual void 		taskDied();
-
-    virtual IOReturn		redirect(IOMemoryDescriptor * newBackingMemory,
-					 IOOptionBits         options,
-					 IOByteCount          offset = 0);
-
-    virtual IOPhysicalAddress 	getPhysicalSegment(IOByteCount offset,
-	       					   IOByteCount * length);
-
-    // for IOMemoryDescriptor use
-    _IOMemoryMap * copyCompatible(
-		IOMemoryDescriptor *	owner,
-                task_t			intoTask,
-                IOVirtualAddress	toAddress,
-                IOOptionBits		options,
-                IOByteCount		offset,
-                IOByteCount		length );
-
-    bool initCompatible(
-	IOMemoryDescriptor *	memory,
-	IOMemoryMap *		superMap,
-        IOByteCount		offset,
-        IOByteCount		length );
-
-    bool initWithDescriptor(
-	IOMemoryDescriptor *	memory,
-	task_t			intoTask,
-	IOVirtualAddress	toAddress,
-	IOOptionBits		options,
-        IOByteCount		offset,
-        IOByteCount		length );
-
-    IOReturn redirect(
-	task_t			intoTask, bool redirect );
-};
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
 // Some data structures and accessor macros used by the initWithOptions
 // Function
 
 enum ioPLBlockFlags {
-    kIOPLOnDevice  = 0x00000001,
-    kIOPLExternUPL = 0x00000002,
+	kIOPLOnDevice  = 0x00000001,
+	kIOPLExternUPL = 0x00000002,
 };
 
-struct typePersMDData
-{
-    const IOGeneralMemoryDescriptor *fMD;
-    ipc_port_t fMemEntry;
+struct IOMDPersistentInitData {
+	const IOGeneralMemoryDescriptor * fMD;
+	IOMemoryReference               * fMemRef;
 };
 
 struct ioPLBlock {
-    upl_t fIOPL;
-    vm_address_t fIOMDOffset;	// The offset of this iopl in descriptor
-    vm_offset_t fPageInfo;	// Pointer to page list or index into it
-    ppnum_t fMappedBase;	// Page number of first page in this iopl
-    unsigned int fPageOffset;	// Offset within first page of iopl
-    unsigned int fFlags;	// Flags
+	upl_t fIOPL;
+	vm_address_t fPageInfo; // Pointer to page list or index into it
+	uint32_t fIOMDOffset;       // The offset of this iopl in descriptor
+	ppnum_t fMappedPage;        // Page number of first page in this iopl
+	unsigned int fPageOffset;   // Offset within first page of iopl
+	unsigned int fFlags;        // Flags
 };
 
+enum { kMaxWireTags = 6 };
+
 struct ioGMDData {
-    IOMapper *fMapper;
-    unsigned int fPageCnt;
-    upl_page_info_t fPageList[];
-    ioPLBlock fBlocks[];
+	IOMapper *  fMapper;
+	uint64_t    fDMAMapAlignment;
+	uint64_t    fMappedBase;
+	uint64_t    fMappedLength;
+	uint64_t    fPreparationID;
+#if IOTRACKING
+	IOTracking  fWireTracking;
+#endif /* IOTRACKING */
+	unsigned int      fPageCnt;
+	uint8_t           fDMAMapNumAddressBits;
+	unsigned char     fDiscontig:1;
+	unsigned char     fCompletionError:1;
+	unsigned char     fMappedBaseValid:1;
+	unsigned char     _resv:3;
+	unsigned char     fDMAAccess:2;
+
+	/* variable length arrays */
+	upl_page_info_t fPageList[1]
+#if __LP64__
+	// align fPageList as for ioPLBlock
+	__attribute__((aligned(sizeof(upl_t))))
+#endif
+	;
+	//ioPLBlock fBlocks[1];
 };
 
-#define getDataP(osd)	((ioGMDData *) (osd)->getBytesNoCopy())
-#define getIOPLList(d)	((ioPLBlock *) &(d->fPageList[d->fPageCnt]))
-#define getNumIOPL(osd, d)	\
+#define getDataP(osd)   ((ioGMDData *) (osd)->getBytesNoCopy())
+#define getIOPLList(d)  ((ioPLBlock *) (void *)&(d->fPageList[d->fPageCnt]))
+#define getNumIOPL(osd, d)      \
     (((osd)->getLength() - ((char *) getIOPLList(d) - (char *) d)) / sizeof(ioPLBlock))
-#define getPageList(d)	(&(d->fPageList[0]))
+#define getPageList(d)  (&(d->fPageList[0]))
 #define computeDataSize(p, u) \
-    (sizeof(ioGMDData) + p * sizeof(upl_page_info_t) + u * sizeof(ioPLBlock))
+    (offsetof(ioGMDData, fPageList) + p * sizeof(upl_page_info_t) + u * sizeof(ioPLBlock))
 
+enum { kIOMemoryHostOrRemote = kIOMemoryHostOnly | kIOMemoryRemote };
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#define next_page(a) ( trunc_page_32(a) + PAGE_SIZE )
-
+#define next_page(a) ( trunc_page(a) + PAGE_SIZE )
 
 extern "C" {
+kern_return_t
+device_data_action(
+	uintptr_t               device_handle,
+	ipc_port_t              device_pager,
+	vm_prot_t               protection,
+	vm_object_offset_t      offset,
+	vm_size_t               size)
+{
+	kern_return_t        kr;
+	IOMemoryDescriptorReserved * ref = (IOMemoryDescriptorReserved *) device_handle;
+	IOMemoryDescriptor * memDesc;
+
+	LOCK;
+	memDesc = ref->dp.memory;
+	if (memDesc) {
+		memDesc->retain();
+		kr = memDesc->handleFault(device_pager, offset, size);
+		memDesc->release();
+	} else {
+		kr = KERN_ABORTED;
+	}
+	UNLOCK;
+
+	return kr;
+}
+
+kern_return_t
+device_close(
+	uintptr_t     device_handle)
+{
+	IOMemoryDescriptorReserved * ref = (IOMemoryDescriptorReserved *) device_handle;
+
+	IODelete( ref, IOMemoryDescriptorReserved, 1 );
+
+	return kIOReturnSuccess;
+}
+};      // end extern "C"
 
-kern_return_t device_data_action(
-               int                     device_handle, 
-               ipc_port_t              device_pager,
-               vm_prot_t               protection, 
-               vm_object_offset_t      offset, 
-               vm_size_t               size)
-{
-    struct ExpansionData {
-        void *				devicePager;
-        unsigned int			pagerContig:1;
-        unsigned int			unused:31;
-	IOMemoryDescriptor *		memory;
-    };
-    kern_return_t	 kr;
-    ExpansionData *      ref = (ExpansionData *) device_handle;
-    IOMemoryDescriptor * memDesc;
-
-    LOCK;
-    memDesc = ref->memory;
-    if( memDesc)
-    {
-	memDesc->retain();
-	kr = memDesc->handleFault( device_pager, 0, 0,
-                offset, size, kIOMapDefaultCache /*?*/);
-	memDesc->release();
-    }
-    else
-	kr = KERN_ABORTED;
-    UNLOCK;
-
-    return( kr );
-}
-
-kern_return_t device_close(
-               int     device_handle)
-{
-    struct ExpansionData {
-        void *				devicePager;
-        unsigned int			pagerContig:1;
-        unsigned int			unused:31;
-	IOMemoryDescriptor *		memory;
-    };
-    ExpansionData *   ref = (ExpansionData *) device_handle;
-
-    IODelete( ref, ExpansionData, 1 );
-
-    return( kIOReturnSuccess );
-}
-};	// end extern "C"
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 // Note this inline function uses C++ reference arguments to return values
 // This means that pointers are not passed and NULLs don't have to be
 // checked for as a NULL reference is illegal.
 static inline void
-getAddrLenForInd(addr64_t &addr, IOPhysicalLength &len, // Output variables
-     UInt32 type, IOGeneralMemoryDescriptor::Ranges r, UInt32 ind)
-{
-    assert(kIOMemoryTypeUIO       == type
-	|| kIOMemoryTypeVirtual   == type || kIOMemoryTypeVirtual64 == type
-	|| kIOMemoryTypePhysical  == type || kIOMemoryTypePhysical64 == type);
-    if (kIOMemoryTypeUIO == type) {
-	user_size_t us;
-	uio_getiov((uio_t) r.uio, ind, &addr, &us); len = us;
-    }
-    else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type)) {
-	IOAddressRange cur = r.v64[ind];
-	addr = cur.address;
-	len  = cur.length;
-    }
-    else {
-	IOVirtualRange cur = r.v[ind];
-	addr = cur.address;
-	len  = cur.length;
-    }
+getAddrLenForInd(mach_vm_address_t &addr, mach_vm_size_t &len, // Output variables
+    UInt32 type, IOGeneralMemoryDescriptor::Ranges r, UInt32 ind)
+{
+	assert(kIOMemoryTypeUIO == type
+	    || kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type
+	    || kIOMemoryTypePhysical == type || kIOMemoryTypePhysical64 == type);
+	if (kIOMemoryTypeUIO == type) {
+		user_size_t us;
+		user_addr_t ad;
+		uio_getiov((uio_t) r.uio, ind, &ad, &us); addr = ad; len = us;
+	}
+#ifndef __LP64__
+	else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type)) {
+		IOAddressRange cur = r.v64[ind];
+		addr = cur.address;
+		len  = cur.length;
+	}
+#endif /* !__LP64__ */
+	else {
+		IOVirtualRange cur = r.v[ind];
+		addr = cur.address;
+		len  = cur.length;
+	}
 }
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/*
- * withAddress:
- *
- * Create a new IOMemoryDescriptor.  The buffer is a virtual address
- * relative to the specified task.  If no task is supplied, the kernel
- * task is implied.
- */
-IOMemoryDescriptor *
-IOMemoryDescriptor::withAddress(void *      address,
-                                IOByteCount   length,
-                                IODirection direction)
+static IOReturn
+purgeableControlBits(IOOptionBits newState, vm_purgable_t * control, int * state)
 {
-    return IOMemoryDescriptor::
-        withAddress((vm_address_t) address, length, direction, kernel_task);
-}
+	IOReturn err = kIOReturnSuccess;
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withAddress(vm_address_t address,
-                                IOByteCount  length,
-                                IODirection  direction,
-                                task_t       task)
-{
-#if TEST_V64
-    if (task)
-    {
-	IOOptionBits options = (IOOptionBits) direction;
-	if (task == kernel_task)
-	    options |= kIOMemoryAutoPrepare;
-	return (IOMemoryDescriptor::withAddressRange(address, length, options, task));
-    }
-#endif
-    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
-    if (that)
-    {
-	if (that->initWithAddress(address, length, direction, task))
-	    return that;
+	*control = VM_PURGABLE_SET_STATE;
 
-        that->release();
-    }
-    return 0;
-}
+	enum { kIOMemoryPurgeableControlMask = 15 };
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withPhysicalAddress(
-				IOPhysicalAddress	address,
-				IOByteCount		length,
-				IODirection      	direction )
-{
-#if TEST_P64
-    return (IOMemoryDescriptor::withAddressRange(address, length, (IOOptionBits) direction, NULL));
-#endif
-    IOGeneralMemoryDescriptor *self = new IOGeneralMemoryDescriptor;
-    if (self
-    && !self->initWithPhysicalAddress(address, length, direction)) {
-        self->release();
-        return 0;
-    }
+	switch (kIOMemoryPurgeableControlMask & newState) {
+	case kIOMemoryPurgeableKeepCurrent:
+		*control = VM_PURGABLE_GET_STATE;
+		break;
+
+	case kIOMemoryPurgeableNonVolatile:
+		*state = VM_PURGABLE_NONVOLATILE;
+		break;
+	case kIOMemoryPurgeableVolatile:
+		*state = VM_PURGABLE_VOLATILE | (newState & ~kIOMemoryPurgeableControlMask);
+		break;
+	case kIOMemoryPurgeableEmpty:
+		*state = VM_PURGABLE_EMPTY | (newState & ~kIOMemoryPurgeableControlMask);
+		break;
+	default:
+		err = kIOReturnBadArgument;
+		break;
+	}
 
-    return self;
+	if (*control == VM_PURGABLE_SET_STATE) {
+		// let VM know this call is from the kernel and is allowed to alter
+		// the volatility of the memory entry even if it was created with
+		// MAP_MEM_PURGABLE_KERNEL_ONLY
+		*control = VM_PURGABLE_SET_STATE_FROM_KERNEL;
+	}
+
+	return err;
 }
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withRanges(	IOVirtualRange * ranges,
-				UInt32           withCount,
-				IODirection      direction,
-				task_t           task,
-				bool             asReference)
+static IOReturn
+purgeableStateBits(int * state)
 {
-    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
-    if (that)
-    {
-	if (that->initWithRanges(ranges, withCount, direction, task, asReference))
-	    return that;
+	IOReturn err = kIOReturnSuccess;
 
-        that->release();
-    }
-    return 0;
+	switch (VM_PURGABLE_STATE_MASK & *state) {
+	case VM_PURGABLE_NONVOLATILE:
+		*state = kIOMemoryPurgeableNonVolatile;
+		break;
+	case VM_PURGABLE_VOLATILE:
+		*state = kIOMemoryPurgeableVolatile;
+		break;
+	case VM_PURGABLE_EMPTY:
+		*state = kIOMemoryPurgeableEmpty;
+		break;
+	default:
+		*state = kIOMemoryPurgeableNonVolatile;
+		err = kIOReturnNotReady;
+		break;
+	}
+	return err;
 }
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withAddressRange(mach_vm_address_t address,
-                                       mach_vm_size_t length,
-                                       IOOptionBits   options,
-                                       task_t         task)
+typedef struct {
+	unsigned int wimg;
+	unsigned int object_type;
+} iokit_memtype_entry;
+
+static const iokit_memtype_entry iomd_mem_types[] = {
+	[kIODefaultCache] = {VM_WIMG_DEFAULT, MAP_MEM_NOOP},
+	[kIOInhibitCache] = {VM_WIMG_IO, MAP_MEM_IO},
+	[kIOWriteThruCache] = {VM_WIMG_WTHRU, MAP_MEM_WTHRU},
+	[kIOWriteCombineCache] = {VM_WIMG_WCOMB, MAP_MEM_WCOMB},
+	[kIOCopybackCache] = {VM_WIMG_COPYBACK, MAP_MEM_COPYBACK},
+	[kIOCopybackInnerCache] = {VM_WIMG_INNERWBACK, MAP_MEM_INNERWBACK},
+	[kIOPostedWrite] = {VM_WIMG_POSTED, MAP_MEM_POSTED},
+	[kIORealTimeCache] = {VM_WIMG_RT, MAP_MEM_RT},
+	[kIOPostedReordered] = {VM_WIMG_POSTED_REORDERED, MAP_MEM_POSTED_REORDERED},
+	[kIOPostedCombinedReordered] = {VM_WIMG_POSTED_COMBINED_REORDERED, MAP_MEM_POSTED_COMBINED_REORDERED},
+};
+
+static vm_prot_t
+vmProtForCacheMode(IOOptionBits cacheMode)
 {
-    IOAddressRange range = { address, length };
-    return (IOMemoryDescriptor::withAddressRanges(&range, 1, options, task));
+	assert(cacheMode < (sizeof(iomd_mem_types) / sizeof(iomd_mem_types[0])));
+	vm_prot_t prot = 0;
+	SET_MAP_MEM(iomd_mem_types[cacheMode].object_type, prot);
+	return prot;
 }
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withAddressRanges(IOAddressRange *   ranges,
-                                       UInt32           rangeCount,
-                                       IOOptionBits     options,
-                                       task_t           task)
+static unsigned int
+pagerFlagsForCacheMode(IOOptionBits cacheMode)
 {
-    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
-    if (that)
-    {
-	if (task)
-	    options |= kIOMemoryTypeVirtual64;
-	else
-	    options |= kIOMemoryTypePhysical64;
-
-       if (that->initWithOptions(ranges, rangeCount, 0, task, options, /* mapper */ 0))
-           return that;
-
-       that->release();
-    }
+	assert(cacheMode < (sizeof(iomd_mem_types) / sizeof(iomd_mem_types[0])));
+	if (cacheMode == kIODefaultCache) {
+		return -1U;
+	}
+	return iomd_mem_types[cacheMode].wimg;
+}
 
-    return 0;
+static IOOptionBits
+cacheModeForPagerFlags(unsigned int pagerFlags)
+{
+	pagerFlags &= VM_WIMG_MASK;
+	IOOptionBits cacheMode = kIODefaultCache;
+	for (IOOptionBits i = 0; i < (sizeof(iomd_mem_types) / sizeof(iomd_mem_types[0])); ++i) {
+		if (iomd_mem_types[i].wimg == pagerFlags) {
+			cacheMode = i;
+			break;
+		}
+	}
+	return (cacheMode == kIODefaultCache) ? kIOCopybackCache : cacheMode;
 }
 
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/*
- * withRanges:
- *
- * Create a new IOMemoryDescriptor. The buffer is made up of several
- * virtual address ranges, from a given task.
- *
- * Passing the ranges as a reference will avoid an extra allocation.
- */
-IOMemoryDescriptor *
-IOMemoryDescriptor::withOptions(void *		buffers,
-                                UInt32		count,
-                                UInt32		offset,
-                                task_t		task,
-                                IOOptionBits	opts,
-                                IOMapper *	mapper)
-{
-    IOGeneralMemoryDescriptor *self = new IOGeneralMemoryDescriptor;
+struct IOMemoryEntry {
+	ipc_port_t entry;
+	int64_t    offset;
+	uint64_t   size;
+};
 
-    if (self
-    && !self->initWithOptions(buffers, count, offset, task, opts, mapper))
-    {
-        self->release();
-        return 0;
-    }
+struct IOMemoryReference {
+	volatile SInt32             refCount;
+	vm_prot_t                   prot;
+	uint32_t                    capacity;
+	uint32_t                    count;
+	struct IOMemoryReference  * mapRef;
+	IOMemoryEntry               entries[0];
+};
 
-    return self;
-}
+enum{
+	kIOMemoryReferenceReuse = 0x00000001,
+	kIOMemoryReferenceWrite = 0x00000002,
+	kIOMemoryReferenceCOW   = 0x00000004,
+};
+
+SInt32 gIOMemoryReferenceCount;
 
-// Can't leave abstract but this should never be used directly,
-bool IOMemoryDescriptor::initWithOptions(void *		buffers,
-                                         UInt32		count,
-                                         UInt32		offset,
-                                         task_t		task,
-                                         IOOptionBits	options,
-                                         IOMapper *	mapper)
+IOMemoryReference *
+IOGeneralMemoryDescriptor::memoryReferenceAlloc(uint32_t capacity, IOMemoryReference * realloc)
 {
-    // @@@ gvdl: Should I panic?
-    panic("IOMD::initWithOptions called\n");
-    return 0;
+	IOMemoryReference * ref;
+	size_t              newSize, oldSize, copySize;
+
+	newSize = (sizeof(IOMemoryReference)
+	    - sizeof(ref->entries)
+	    + capacity * sizeof(ref->entries[0]));
+	ref = (typeof(ref))IOMalloc(newSize);
+	if (realloc) {
+		oldSize = (sizeof(IOMemoryReference)
+		    - sizeof(realloc->entries)
+		    + realloc->capacity * sizeof(realloc->entries[0]));
+		copySize = oldSize;
+		if (copySize > newSize) {
+			copySize = newSize;
+		}
+		if (ref) {
+			bcopy(realloc, ref, copySize);
+		}
+		IOFree(realloc, oldSize);
+	} else if (ref) {
+		bzero(ref, sizeof(*ref));
+		ref->refCount = 1;
+		OSIncrementAtomic(&gIOMemoryReferenceCount);
+	}
+	if (!ref) {
+		return NULL;
+	}
+	ref->capacity = capacity;
+	return ref;
 }
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withPhysicalRanges(	IOPhysicalRange * ranges,
-                                        UInt32          withCount,
-                                        IODirection     direction,
-                                        bool            asReference)
+void
+IOGeneralMemoryDescriptor::memoryReferenceFree(IOMemoryReference * ref)
 {
-    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
-    if (that)
-    {
-	if (that->initWithPhysicalRanges(ranges, withCount, direction, asReference))
-	    return that;
+	IOMemoryEntry * entries;
+	size_t          size;
 
-        that->release();
-    }
-    return 0;
-}
+	if (ref->mapRef) {
+		memoryReferenceFree(ref->mapRef);
+		ref->mapRef = NULL;
+	}
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withSubRange(IOMemoryDescriptor *	of,
-				IOByteCount		offset,
-				IOByteCount		length,
-				IODirection		direction)
-{
-    IOSubMemoryDescriptor *self = new IOSubMemoryDescriptor;
+	entries = ref->entries + ref->count;
+	while (entries > &ref->entries[0]) {
+		entries--;
+		ipc_port_release_send(entries->entry);
+	}
+	size = (sizeof(IOMemoryReference)
+	    - sizeof(ref->entries)
+	    + ref->capacity * sizeof(ref->entries[0]));
+	IOFree(ref, size);
 
-    if (self && !self->initSubRange(of, offset, length, direction)) {
-        self->release();
-	self = 0;
-    }
-    return self;
+	OSDecrementAtomic(&gIOMemoryReferenceCount);
 }
 
-IOMemoryDescriptor *
-IOMemoryDescriptor::withPersistentMemoryDescriptor(IOMemoryDescriptor *originalMD)
+void
+IOGeneralMemoryDescriptor::memoryReferenceRelease(IOMemoryReference * ref)
 {
-    IOGeneralMemoryDescriptor *origGenMD = 
-	OSDynamicCast(IOGeneralMemoryDescriptor, originalMD);
-
-    if (origGenMD)
-	return IOGeneralMemoryDescriptor::
-	    withPersistentMemoryDescriptor(origGenMD);
-    else
-	return 0;
+	if (1 == OSDecrementAtomic(&ref->refCount)) {
+		memoryReferenceFree(ref);
+	}
 }
 
-IOMemoryDescriptor *
-IOGeneralMemoryDescriptor::withPersistentMemoryDescriptor(IOGeneralMemoryDescriptor *originalMD)
+
+IOReturn
+IOGeneralMemoryDescriptor::memoryReferenceCreate(
+	IOOptionBits         options,
+	IOMemoryReference ** reference)
 {
-    ipc_port_t sharedMem = (ipc_port_t) originalMD->createNamedEntry();
+	enum { kCapacity = 4, kCapacityInc = 4 };
+
+	kern_return_t        err;
+	IOMemoryReference *  ref;
+	IOMemoryEntry *      entries;
+	IOMemoryEntry *      cloneEntries;
+	vm_map_t             map;
+	ipc_port_t           entry, cloneEntry;
+	vm_prot_t            prot;
+	memory_object_size_t actualSize;
+	uint32_t             rangeIdx;
+	uint32_t             count;
+	mach_vm_address_t    entryAddr, endAddr, entrySize;
+	mach_vm_size_t       srcAddr, srcLen;
+	mach_vm_size_t       nextAddr, nextLen;
+	mach_vm_size_t       offset, remain;
+	IOByteCount          physLen;
+	IOOptionBits         type = (_flags & kIOMemoryTypeMask);
+	IOOptionBits         cacheMode;
+	unsigned int         pagerFlags;
+	vm_tag_t             tag;
+	vm_named_entry_kernel_flags_t vmne_kflags;
+
+	ref = memoryReferenceAlloc(kCapacity, NULL);
+	if (!ref) {
+		return kIOReturnNoMemory;
+	}
 
-    if (!sharedMem)
-	return 0;
-   
-    if (sharedMem == originalMD->_memEntry) {
-	originalMD->retain();		    // Add a new reference to ourselves
-	ipc_port_release_send(sharedMem);   // Remove extra send right
-	return originalMD;
-    }
+	tag = getVMTag(kernel_map);
+	vmne_kflags = VM_NAMED_ENTRY_KERNEL_FLAGS_NONE;
+	entries = &ref->entries[0];
+	count = 0;
+	err = KERN_SUCCESS;
 
-    IOGeneralMemoryDescriptor * self = new IOGeneralMemoryDescriptor;
-    typePersMDData initData = { originalMD, sharedMem };
+	offset = 0;
+	rangeIdx = 0;
+	if (_task) {
+		getAddrLenForInd(nextAddr, nextLen, type, _ranges, rangeIdx);
+	} else {
+		nextAddr = getPhysicalSegment(offset, &physLen, kIOMemoryMapperNone);
+		nextLen = physLen;
 
-    if (self
-    && !self->initWithOptions(&initData, 1, 0, 0, kIOMemoryTypePersistentMD, 0)) {
-        self->release();
-	self = 0;
-    }
-    return self;
-}
+		// default cache mode for physical
+		if (kIODefaultCache == ((_flags & kIOMemoryBufferCacheMask) >> kIOMemoryBufferCacheShift)) {
+			IOOptionBits mode = cacheModeForPagerFlags(IODefaultCacheBits(nextAddr));
+			_flags |= (mode << kIOMemoryBufferCacheShift);
+		}
+	}
 
-void *IOGeneralMemoryDescriptor::createNamedEntry()
-{
-    kern_return_t error;
-    ipc_port_t sharedMem;
+	// cache mode & vm_prot
+	prot = VM_PROT_READ;
+	cacheMode = ((_flags & kIOMemoryBufferCacheMask) >> kIOMemoryBufferCacheShift);
+	prot |= vmProtForCacheMode(cacheMode);
+	// VM system requires write access to change cache mode
+	if (kIODefaultCache != cacheMode) {
+		prot |= VM_PROT_WRITE;
+	}
+	if (kIODirectionOut != (kIODirectionOutIn & _flags)) {
+		prot |= VM_PROT_WRITE;
+	}
+	if (kIOMemoryReferenceWrite & options) {
+		prot |= VM_PROT_WRITE;
+	}
+	if (kIOMemoryReferenceCOW   & options) {
+		prot |= MAP_MEM_VM_COPY;
+	}
 
-    IOOptionBits type = _flags & kIOMemoryTypeMask;
+	if (kIOMemoryUseReserve & _flags) {
+		prot |= MAP_MEM_GRAB_SECLUDED;
+	}
+
+	if ((kIOMemoryReferenceReuse & options) && _memRef) {
+		cloneEntries = &_memRef->entries[0];
+		prot |= MAP_MEM_NAMED_REUSE;
+	}
 
-    user_addr_t range0Addr;
-    IOByteCount range0Len;
-    getAddrLenForInd(range0Addr, range0Len, type, _ranges, 0);
-    range0Addr = trunc_page_64(range0Addr);
+	if (_task) {
+		// virtual ranges
+
+		if (kIOMemoryBufferPageable & _flags) {
+			int ledger_tag, ledger_no_footprint;
+
+			// IOBufferMemoryDescriptor alloc - set flags for entry + object create
+			prot |= MAP_MEM_NAMED_CREATE;
+
+			// default accounting settings:
+			//   + "none" ledger tag
+			//   + include in footprint
+			// can be changed later with ::setOwnership()
+			ledger_tag = VM_LEDGER_TAG_NONE;
+			ledger_no_footprint = 0;
+
+			if (kIOMemoryBufferPurgeable & _flags) {
+				prot |= (MAP_MEM_PURGABLE | MAP_MEM_PURGABLE_KERNEL_ONLY);
+				if (VM_KERN_MEMORY_SKYWALK == tag) {
+					// Skywalk purgeable memory accounting:
+					//    + "network" ledger tag
+					//    + not included in footprint
+					ledger_tag = VM_LEDGER_TAG_NETWORK;
+					ledger_no_footprint = 1;
+				} else {
+					// regular purgeable memory accounting:
+					//    + no ledger tag
+					//    + included in footprint
+					ledger_tag = VM_LEDGER_TAG_NONE;
+					ledger_no_footprint = 0;
+				}
+			}
+			vmne_kflags.vmnekf_ledger_tag = ledger_tag;
+			vmne_kflags.vmnekf_ledger_no_footprint = ledger_no_footprint;
+			if (kIOMemoryUseReserve & _flags) {
+				prot |= MAP_MEM_GRAB_SECLUDED;
+			}
+
+			prot |= VM_PROT_WRITE;
+			map = NULL;
+		} else {
+			map = get_task_map(_task);
+		}
 
-    vm_size_t size = ptoa_32(_pages);
-    vm_address_t kernelPage = (vm_address_t) range0Addr;
+		remain = _length;
+		while (remain) {
+			srcAddr  = nextAddr;
+			srcLen   = nextLen;
+			nextAddr = 0;
+			nextLen  = 0;
+			// coalesce addr range
+			for (++rangeIdx; rangeIdx < _rangesCount; rangeIdx++) {
+				getAddrLenForInd(nextAddr, nextLen, type, _ranges, rangeIdx);
+				if ((srcAddr + srcLen) != nextAddr) {
+					break;
+				}
+				srcLen += nextLen;
+			}
+			entryAddr = trunc_page_64(srcAddr);
+			endAddr   = round_page_64(srcAddr + srcLen);
+			do{
+				entrySize = (endAddr - entryAddr);
+				if (!entrySize) {
+					break;
+				}
+				actualSize = entrySize;
+
+				cloneEntry = MACH_PORT_NULL;
+				if (MAP_MEM_NAMED_REUSE & prot) {
+					if (cloneEntries < &_memRef->entries[_memRef->count]) {
+						cloneEntry = cloneEntries->entry;
+					} else {
+						prot &= ~MAP_MEM_NAMED_REUSE;
+					}
+				}
+
+				err = mach_make_memory_entry_internal(map,
+				    &actualSize, entryAddr, prot, vmne_kflags, &entry, cloneEntry);
+
+				if (KERN_SUCCESS != err) {
+					break;
+				}
+				if (actualSize > entrySize) {
+					panic("mach_make_memory_entry_64 actualSize");
+				}
+
+				if (count >= ref->capacity) {
+					ref = memoryReferenceAlloc(ref->capacity + kCapacityInc, ref);
+					entries = &ref->entries[count];
+				}
+				entries->entry  = entry;
+				entries->size   = actualSize;
+				entries->offset = offset + (entryAddr - srcAddr);
+				entryAddr += actualSize;
+				if (MAP_MEM_NAMED_REUSE & prot) {
+					if ((cloneEntries->entry == entries->entry)
+					    && (cloneEntries->size == entries->size)
+					    && (cloneEntries->offset == entries->offset)) {
+						cloneEntries++;
+					} else {
+						prot &= ~MAP_MEM_NAMED_REUSE;
+					}
+				}
+				entries++;
+				count++;
+			}while (true);
+			offset += srcLen;
+			remain -= srcLen;
+		}
+	} else {
+		// _task == 0, physical or kIOMemoryTypeUPL
+		memory_object_t pager;
+		vm_size_t       size = ptoa_64(_pages);
 
-    vm_map_t theMap = ((_task == kernel_task)
-			&& (kIOMemoryBufferPageable & _flags)) 
-		    ? IOPageableMapForAddress(kernelPage)
-		    : get_task_map(_task);
+		if (!getKernelReserved()) {
+			panic("getKernelReserved");
+		}
 
-    memory_object_size_t  actualSize = size;
-    vm_prot_t prot = VM_PROT_READ | VM_PROT_WRITE;
-    if (_memEntry)
-	prot |= MAP_MEM_NAMED_REUSE;
+		reserved->dp.pagerContig = (1 == _rangesCount);
+		reserved->dp.memory      = this;
 
-    error = mach_make_memory_entry_64(theMap,
-	    &actualSize, range0Addr, prot, &sharedMem, (ipc_port_t) _memEntry);
+		pagerFlags = pagerFlagsForCacheMode(cacheMode);
+		if (-1U == pagerFlags) {
+			panic("phys is kIODefaultCache");
+		}
+		if (reserved->dp.pagerContig) {
+			pagerFlags |= DEVICE_PAGER_CONTIGUOUS;
+		}
 
-    if (KERN_SUCCESS == error) {
-	if (actualSize == size) {
-	    return sharedMem;
-	} else {
-#if IOASSERT
-	    IOLog("IOGMD::mach_make_memory_entry_64 (%08llx) size (%08lx:%08x)\n",
-			(UInt64)range0Addr, (UInt32)actualSize, size);
-#endif    
-	    ipc_port_release_send( sharedMem );
+		pager = device_pager_setup((memory_object_t) NULL, (uintptr_t) reserved,
+		    size, pagerFlags);
+		assert(pager);
+		if (!pager) {
+			err = kIOReturnVMError;
+		} else {
+			srcAddr  = nextAddr;
+			entryAddr = trunc_page_64(srcAddr);
+			err = mach_memory_object_memory_entry_64((host_t) 1, false /*internal*/,
+			    size, VM_PROT_READ | VM_PROT_WRITE, pager, &entry);
+			assert(KERN_SUCCESS == err);
+			if (KERN_SUCCESS != err) {
+				device_pager_deallocate(pager);
+			} else {
+				reserved->dp.devicePager = pager;
+				entries->entry  = entry;
+				entries->size   = size;
+				entries->offset = offset + (entryAddr - srcAddr);
+				entries++;
+				count++;
+			}
+		}
 	}
-    }
 
-    return MACH_PORT_NULL;
-}
+	ref->count = count;
+	ref->prot  = prot;
 
-/*
- * initWithAddress:
- *
- * Initialize an IOMemoryDescriptor. The buffer is a virtual address
- * relative to the specified task.  If no task is supplied, the kernel
- * task is implied.
- *
- * An IOMemoryDescriptor can be re-used by calling initWithAddress or
- * initWithRanges again on an existing instance -- note this behavior
- * is not commonly supported in other I/O Kit classes, although it is
- * supported here.
- */
-bool
-IOGeneralMemoryDescriptor::initWithAddress(void *      address,
-                                    IOByteCount   withLength,
-                                    IODirection withDirection)
-{
-    _singleRange.v.address = (vm_address_t) address;
-    _singleRange.v.length  = withLength;
+	if (_task && (KERN_SUCCESS == err)
+	    && (kIOMemoryMapCopyOnWrite & _flags)
+	    && !(kIOMemoryReferenceCOW & options)) {
+		err = memoryReferenceCreate(options | kIOMemoryReferenceCOW, &ref->mapRef);
+	}
 
-    return initWithRanges(&_singleRange.v, 1, withDirection, kernel_task, true);
-}
+	if (KERN_SUCCESS == err) {
+		if (MAP_MEM_NAMED_REUSE & prot) {
+			memoryReferenceFree(ref);
+			OSIncrementAtomic(&_memRef->refCount);
+			ref = _memRef;
+		}
+	} else {
+		memoryReferenceFree(ref);
+		ref = NULL;
+	}
 
-bool
-IOGeneralMemoryDescriptor::initWithAddress(vm_address_t address,
-                                    IOByteCount    withLength,
-                                    IODirection  withDirection,
-                                    task_t       withTask)
-{
-    _singleRange.v.address = address;
-    _singleRange.v.length  = withLength;
+	*reference = ref;
 
-    return initWithRanges(&_singleRange.v, 1, withDirection, withTask, true);
+	return err;
 }
 
-bool
-IOGeneralMemoryDescriptor::initWithPhysicalAddress(
-				 IOPhysicalAddress	address,
-				 IOByteCount		withLength,
-				 IODirection      	withDirection )
+kern_return_t
+IOMemoryDescriptorMapAlloc(vm_map_t map, void * _ref)
 {
-    _singleRange.p.address = address;
-    _singleRange.p.length  = withLength;
+	IOMemoryDescriptorMapAllocRef * ref = (typeof(ref))_ref;
+	IOReturn                        err;
+	vm_map_offset_t                 addr;
+
+	addr = ref->mapped;
+
+	err = vm_map_enter_mem_object(map, &addr, ref->size,
+	    (vm_map_offset_t) 0,
+	    (((ref->options & kIOMapAnywhere)
+	    ? VM_FLAGS_ANYWHERE
+	    : VM_FLAGS_FIXED)),
+	    VM_MAP_KERNEL_FLAGS_NONE,
+	    ref->tag,
+	    IPC_PORT_NULL,
+	    (memory_object_offset_t) 0,
+	    false,                       /* copy */
+	    ref->prot,
+	    ref->prot,
+	    VM_INHERIT_NONE);
+	if (KERN_SUCCESS == err) {
+		ref->mapped = (mach_vm_address_t) addr;
+		ref->map = map;
+	}
 
-    return initWithPhysicalRanges( &_singleRange.p, 1, withDirection, true);
+	return err;
 }
 
-bool
-IOGeneralMemoryDescriptor::initWithPhysicalRanges(
-                                IOPhysicalRange * ranges,
-                                UInt32            count,
-                                IODirection       direction,
-                                bool              reference)
+IOReturn
+IOGeneralMemoryDescriptor::memoryReferenceMap(
+	IOMemoryReference * ref,
+	vm_map_t            map,
+	mach_vm_size_t      inoffset,
+	mach_vm_size_t      size,
+	IOOptionBits        options,
+	mach_vm_address_t * inaddr)
 {
-    IOOptionBits mdOpts = direction | kIOMemoryTypePhysical;
+	IOReturn        err;
+	int64_t         offset = inoffset;
+	uint32_t        rangeIdx, entryIdx;
+	vm_map_offset_t addr, mapAddr;
+	vm_map_offset_t pageOffset, entryOffset, remain, chunk;
+
+	mach_vm_address_t nextAddr;
+	mach_vm_size_t    nextLen;
+	IOByteCount       physLen;
+	IOMemoryEntry   * entry;
+	vm_prot_t         prot, memEntryCacheMode;
+	IOOptionBits      type;
+	IOOptionBits      cacheMode;
+	vm_tag_t          tag;
+	// for the kIOMapPrefault option.
+	upl_page_info_t * pageList = NULL;
+	UInt              currentPageIndex = 0;
+	bool              didAlloc;
+
+	if (ref->mapRef) {
+		err = memoryReferenceMap(ref->mapRef, map, inoffset, size, options, inaddr);
+		return err;
+	}
 
-    if (reference)
-        mdOpts |= kIOMemoryAsReference;
+	type = _flags & kIOMemoryTypeMask;
 
-    return initWithOptions(ranges, count, 0, 0, mdOpts, /* mapper */ 0);
-}
+	prot = VM_PROT_READ;
+	if (!(kIOMapReadOnly & options)) {
+		prot |= VM_PROT_WRITE;
+	}
+	prot &= ref->prot;
 
-bool
-IOGeneralMemoryDescriptor::initWithRanges(
-                                   IOVirtualRange * ranges,
-                                   UInt32           count,
-                                   IODirection      direction,
-                                   task_t           task,
-                                   bool             reference)
-{
-    IOOptionBits mdOpts = direction;
+	cacheMode = ((options & kIOMapCacheMask) >> kIOMapCacheShift);
+	if (kIODefaultCache != cacheMode) {
+		// VM system requires write access to update named entry cache mode
+		memEntryCacheMode = (MAP_MEM_ONLY | VM_PROT_WRITE | prot | vmProtForCacheMode(cacheMode));
+	}
 
-    if (reference)
-        mdOpts |= kIOMemoryAsReference;
+	tag = getVMTag(map);
 
-    if (task) {
-        mdOpts |= kIOMemoryTypeVirtual;
+	if (_task) {
+		// Find first range for offset
+		if (!_rangesCount) {
+			return kIOReturnBadArgument;
+		}
+		for (remain = offset, rangeIdx = 0; rangeIdx < _rangesCount; rangeIdx++) {
+			getAddrLenForInd(nextAddr, nextLen, type, _ranges, rangeIdx);
+			if (remain < nextLen) {
+				break;
+			}
+			remain -= nextLen;
+		}
+	} else {
+		rangeIdx = 0;
+		remain   = 0;
+		nextAddr = getPhysicalSegment(offset, &physLen, kIOMemoryMapperNone);
+		nextLen  = size;
+	}
 
-	// Auto-prepare if this is a kernel memory descriptor as very few
-	// clients bother to prepare() kernel memory.
-	// But it was not  enforced so what are you going to do?
-        if (task == kernel_task)
-            mdOpts |= kIOMemoryAutoPrepare;
-    }
-    else
-        mdOpts |= kIOMemoryTypePhysical;
-    
-    return initWithOptions(ranges, count, 0, task, mdOpts, /* mapper */ 0);
-}
+	assert(remain < nextLen);
+	if (remain >= nextLen) {
+		return kIOReturnBadArgument;
+	}
 
-/*
- * initWithOptions:
- *
- *  IOMemoryDescriptor. The buffer is made up of several virtual address ranges,
- * from a given task, several physical ranges, an UPL from the ubc
- * system or a uio (may be 64bit) from the BSD subsystem.
- *
- * Passing the ranges as a reference will avoid an extra allocation.
- *
- * An IOMemoryDescriptor can be re-used by calling initWithOptions again on an
- * existing instance -- note this behavior is not commonly supported in other
- * I/O Kit classes, although it is supported here.
- */
+	nextAddr  += remain;
+	nextLen   -= remain;
+	pageOffset = (page_mask & nextAddr);
+	addr       = 0;
+	didAlloc   = false;
 
-bool
-IOGeneralMemoryDescriptor::initWithOptions(void *	buffers,
-                                           UInt32	count,
-                                           UInt32	offset,
-                                           task_t	task,
-                                           IOOptionBits	options,
-                                           IOMapper *	mapper)
-{
-    IOOptionBits type = options & kIOMemoryTypeMask;
-
-    // Grab the original MD's configuation data to initialse the
-    // arguments to this function.
-    if (kIOMemoryTypePersistentMD == type) {
-
-	typePersMDData *initData = (typePersMDData *) buffers;
-	const IOGeneralMemoryDescriptor *orig = initData->fMD;
-	ioGMDData *dataP = getDataP(orig->_memoryEntries);
-
-	// Only accept persistent memory descriptors with valid dataP data.
-	assert(orig->_rangesCount == 1);
-	if ( !(orig->_flags & kIOMemoryPersistent) || !dataP)
-	    return false;
-
-	_memEntry = initData->fMemEntry;	// Grab the new named entry
-	options = orig->_flags | kIOMemoryAsReference; 
-	_singleRange = orig->_singleRange;	// Initialise our range
-	buffers = &_singleRange;
-	count = 1;
-
-	// Now grab the original task and whatever mapper was previously used
-	task = orig->_task;
-	mapper = dataP->fMapper;
-
-	// We are ready to go through the original initialisation now
-    }
-
-    switch (type) {
-    case kIOMemoryTypeUIO:
-    case kIOMemoryTypeVirtual:
-    case kIOMemoryTypeVirtual64:
-        assert(task);
-        if (!task)
-            return false;
-        else
-            break;
-
-    case kIOMemoryTypePhysical:		// Neither Physical nor UPL should have a task
-    case kIOMemoryTypePhysical64:
-	mapper = kIOMapperNone;
-
-    case kIOMemoryTypeUPL:
-        assert(!task);
-        break;
-    default:
-        return false;	/* bad argument */
-    }
-
-    assert(buffers);
-    assert(count);
-
-    /*
-     * We can check the _initialized  instance variable before having ever set
-     * it to an initial value because I/O Kit guarantees that all our instance
-     * variables are zeroed on an object's allocation.
-     */
-
-    if (_initialized) {
-        /*
-         * An existing memory descriptor is being retargeted to point to
-         * somewhere else.  Clean up our present state.
-         */
-
-        while (_wireCount)
-            complete();
-        if (_ranges.v && _rangesIsAllocated)
-	{
-	    if (kIOMemoryTypeUIO == type)
-		uio_free((uio_t) _ranges.v);
-	    else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type))
-		IODelete(_ranges.v64, IOAddressRange, _rangesCount);
-	    else
-		IODelete(_ranges.v, IOVirtualRange, _rangesCount);
-	}
-	if (_memEntry)
-	    { ipc_port_release_send((ipc_port_t) _memEntry); _memEntry = 0; }
-    }
-    else {
-        if (!super::init())
-            return false;
-        _initialized = true;
-    }
-
-    // Grab the appropriate mapper
-    if (mapper == kIOMapperNone)
-        mapper = 0;	// No Mapper
-    else if (mapper == kIOMapperSystem) {
-        IOMapper::checkForSystemMapper();
-        gIOSystemMapper = mapper = IOMapper::gSystem;
-    }
-
-    // Remove the dynamic internal use flags from the initial setting
-    options 		  &= ~(kIOMemoryPreparedReadOnly);
-    _flags		   = options;
-    _task                  = task;
-
-    // DEPRECATED variable initialisation
-    _direction             = (IODirection) (_flags & kIOMemoryDirectionMask);
-
-    __iomd_reservedA = 0;
-    __iomd_reservedB = 0;
-    __iomd_reservedC = 0;
-
-    _highestPage = 0;
-
-    if (kIOMemoryTypeUPL == type) {
-
-        ioGMDData *dataP;
-        unsigned int dataSize = computeDataSize(/* pages */ 0, /* upls */ 1);
-
-        if (!_memoryEntries) {
-            _memoryEntries = OSData::withCapacity(dataSize);
-            if (!_memoryEntries)
-                return false;
-        }
-        else if (!_memoryEntries->initWithCapacity(dataSize))
-            return false;
-
-        _memoryEntries->appendBytes(0, sizeof(ioGMDData));
-        dataP = getDataP(_memoryEntries);
-        dataP->fMapper = mapper;
-        dataP->fPageCnt = 0;
-
- //       _wireCount++;	// UPLs start out life wired
-
-        _length    = count;
-        _pages    += atop_32(offset + count + PAGE_MASK) - atop_32(offset);
-
-        ioPLBlock iopl;
-        upl_page_info_t *pageList = UPL_GET_INTERNAL_PAGE_LIST((upl_t) buffers);
-
-        iopl.fIOPL = (upl_t) buffers;
-        // Set the flag kIOPLOnDevice convieniently equal to 1
-        iopl.fFlags  = pageList->device | kIOPLExternUPL;
-        iopl.fIOMDOffset = 0;
-
-        _highestPage = upl_get_highest_page(iopl.fIOPL);
-
-        if (!pageList->device) {
-            // Pre-compute the offset into the UPL's page list
-            pageList = &pageList[atop_32(offset)];
-            offset &= PAGE_MASK;
-            if (mapper) {
-                iopl.fMappedBase = mapper->iovmAlloc(_pages);
-                mapper->iovmInsert(iopl.fMappedBase, 0, pageList, _pages);
-            }
-	    else
-		iopl.fMappedBase = 0;
-        }
-	else
-	    iopl.fMappedBase = 0;
-        iopl.fPageInfo = (vm_address_t) pageList;
-        iopl.fPageOffset = offset;
-
-        _memoryEntries->appendBytes(&iopl, sizeof(iopl));
-    }
-    else {
-	// kIOMemoryTypeVirtual  | kIOMemoryTypeVirtual64 | kIOMemoryTypeUIO 
-	// kIOMemoryTypePhysical | kIOMemoryTypePhysical64
-	
-	// Initialize the memory descriptor
-	if (options & kIOMemoryAsReference) {
-	    _rangesIsAllocated = false;
-
-	    // Hack assignment to get the buffer arg into _ranges.
-	    // I'd prefer to do _ranges = (Ranges) buffers, but that doesn't
-	    // work, C++ sigh.
-	    // This also initialises the uio & physical ranges.
-	    _ranges.v = (IOVirtualRange *) buffers;
+	if (!(options & kIOMapAnywhere)) {
+		addr = *inaddr;
+		if (pageOffset != (page_mask & addr)) {
+			return kIOReturnNotAligned;
+		}
+		addr -= pageOffset;
 	}
-	else {
-	    _rangesIsAllocated = true;
-	    switch (_flags & kIOMemoryTypeMask)
-	    {
-	      case kIOMemoryTypeUIO:
-		_ranges.v = (IOVirtualRange *) uio_duplicate((uio_t) buffers);
-		break;
 
-	      case kIOMemoryTypeVirtual64:
-	      case kIOMemoryTypePhysical64:
-		_ranges.v64 = IONew(IOAddressRange, count);
-		if (!_ranges.v64)
-		    return false;
-		bcopy(buffers, _ranges.v, count * sizeof(IOAddressRange));
-		break;
-	      case kIOMemoryTypeVirtual:
-		_ranges.v = IONew(IOVirtualRange, count);
-		if (!_ranges.v)
-		    return false;
-		bcopy(buffers, _ranges.v, count * sizeof(IOVirtualRange));
-		break;
-	    }
-	} 
+	// find first entry for offset
+	for (entryIdx = 0;
+	    (entryIdx < ref->count) && (offset >= ref->entries[entryIdx].offset);
+	    entryIdx++) {
+	}
+	entryIdx--;
+	entry = &ref->entries[entryIdx];
+
+	// allocate VM
+	size = round_page_64(size + pageOffset);
+	if (kIOMapOverwrite & options) {
+		if ((map == kernel_map) && (kIOMemoryBufferPageable & _flags)) {
+			map = IOPageableMapForAddress(addr);
+		}
+		err = KERN_SUCCESS;
+	} else {
+		IOMemoryDescriptorMapAllocRef ref;
+		ref.map     = map;
+		ref.tag     = tag;
+		ref.options = options;
+		ref.size    = size;
+		ref.prot    = prot;
+		if (options & kIOMapAnywhere) {
+			// vm_map looks for addresses above here, even when VM_FLAGS_ANYWHERE
+			ref.mapped = 0;
+		} else {
+			ref.mapped = addr;
+		}
+		if ((ref.map == kernel_map) && (kIOMemoryBufferPageable & _flags)) {
+			err = IOIteratePageableMaps( ref.size, &IOMemoryDescriptorMapAlloc, &ref );
+		} else {
+			err = IOMemoryDescriptorMapAlloc(ref.map, &ref);
+		}
+		if (KERN_SUCCESS == err) {
+			addr     = ref.mapped;
+			map      = ref.map;
+			didAlloc = true;
+		}
+	}
 
-	// Find starting address within the vector of ranges
-	Ranges vec = _ranges;
-	UInt32 length = 0;
-	UInt32 pages = 0;
-	for (unsigned ind = 0; ind < count;  ind++) {
-	    user_addr_t addr;
-	    UInt32 len;
-
-	    // addr & len are returned by this function
-	    getAddrLenForInd(addr, len, type, vec, ind);
-	    pages += (atop_64(addr + len + PAGE_MASK) - atop_64(addr));
-	    len += length;
-	    assert(len >= length);	// Check for 32 bit wrap around
-	    length = len;
-
-	    if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type))
-	    {
-		ppnum_t highPage = atop_64(addr + len - 1);
-		if (highPage > _highestPage)
-		    _highestPage = highPage;
-	    }
-	} 
-	_length      = length;
-	_pages       = pages;
-	_rangesCount = count;
-
-        // Auto-prepare memory at creation time.
-        // Implied completion when descriptor is free-ed
-        if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type))
-            _wireCount++;	// Physical MDs are, by definition, wired
-        else { /* kIOMemoryTypeVirtual | kIOMemoryTypeVirtual64 | kIOMemoryTypeUIO */
-            ioGMDData *dataP;
-            unsigned dataSize = computeDataSize(_pages, /* upls */ count * 2);
-
-            if (!_memoryEntries) {
-                _memoryEntries = OSData::withCapacity(dataSize);
-                if (!_memoryEntries)
-		    return false;
-            }
-            else if (!_memoryEntries->initWithCapacity(dataSize))
-                return false;
-    
-            _memoryEntries->appendBytes(0, sizeof(ioGMDData));
-            dataP = getDataP(_memoryEntries);
-            dataP->fMapper = mapper;
-            dataP->fPageCnt = _pages;
-
-	    if ( (kIOMemoryPersistent & _flags) && !_memEntry)
-		_memEntry = createNamedEntry();
-
-            if ((_flags & kIOMemoryAutoPrepare)
-             && prepare() != kIOReturnSuccess)
-                return false;
-        }
-    }
-
-    return true;
-}
+	/*
+	 * If the memory is associated with a device pager but doesn't have a UPL,
+	 * it will be immediately faulted in through the pager via populateDevicePager().
+	 * kIOMapPrefault is redundant in that case, so don't try to use it for UPL
+	 * operations.
+	 */
+	if ((reserved != NULL) && (reserved->dp.devicePager) && (_wireCount != 0)) {
+		options &= ~kIOMapPrefault;
+	}
 
-/*
- * free
- *
- * Free resources.
- */
-void IOGeneralMemoryDescriptor::free()
-{
-    LOCK;
-    if( reserved)
-	reserved->memory = 0;
-    UNLOCK;
+	/*
+	 * Prefaulting is only possible if we wired the memory earlier. Check the
+	 * memory type, and the underlying data.
+	 */
+	if (options & kIOMapPrefault) {
+		/*
+		 * The memory must have been wired by calling ::prepare(), otherwise
+		 * we don't have the UPL. Without UPLs, pages cannot be pre-faulted
+		 */
+		assert(_wireCount != 0);
+		assert(_memoryEntries != NULL);
+		if ((_wireCount == 0) ||
+		    (_memoryEntries == NULL)) {
+			return kIOReturnBadArgument;
+		}
 
-    while (_wireCount)
-        complete();
-    if (_memoryEntries)
-        _memoryEntries->release();
+		// Get the page list.
+		ioGMDData* dataP = getDataP(_memoryEntries);
+		ioPLBlock const* ioplList = getIOPLList(dataP);
+		pageList = getPageList(dataP);
+
+		// Get the number of IOPLs.
+		UInt numIOPLs = getNumIOPL(_memoryEntries, dataP);
+
+		/*
+		 * Scan through the IOPL Info Blocks, looking for the first block containing
+		 * the offset. The research will go past it, so we'll need to go back to the
+		 * right range at the end.
+		 */
+		UInt ioplIndex = 0;
+		while (ioplIndex < numIOPLs && offset >= ioplList[ioplIndex].fIOMDOffset) {
+			ioplIndex++;
+		}
+		ioplIndex--;
+
+		// Retrieve the IOPL info block.
+		ioPLBlock ioplInfo = ioplList[ioplIndex];
+
+		/*
+		 * For external UPLs, the fPageInfo points directly to the UPL's page_info_t
+		 * array.
+		 */
+		if (ioplInfo.fFlags & kIOPLExternUPL) {
+			pageList = (upl_page_info_t*) ioplInfo.fPageInfo;
+		} else {
+			pageList = &pageList[ioplInfo.fPageInfo];
+		}
 
-    if (_ranges.v && _rangesIsAllocated)
-    {
-	IOOptionBits type = _flags & kIOMemoryTypeMask;
-	if (kIOMemoryTypeUIO == type)
-	    uio_free((uio_t) _ranges.v);
-	else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type))
-	    IODelete(_ranges.v64, IOAddressRange, _rangesCount);
-	else
-	    IODelete(_ranges.v, IOVirtualRange, _rangesCount);
-    }
-
-    if (reserved && reserved->devicePager)
-	device_pager_deallocate( (memory_object_t) reserved->devicePager );
-
-    // memEntry holds a ref on the device pager which owns reserved
-    // (ExpansionData) so no reserved access after this point
-    if (_memEntry)
-        ipc_port_release_send( (ipc_port_t) _memEntry );
-
-    super::free();
-}
-
-/* DEPRECATED */ void IOGeneralMemoryDescriptor::unmapFromKernel()
-/* DEPRECATED */ {
-                    panic("IOGMD::unmapFromKernel deprecated");
-/* DEPRECATED */ }
-/* DEPRECATED */ 
-/* DEPRECATED */ void IOGeneralMemoryDescriptor::mapIntoKernel(unsigned rangeIndex)
-/* DEPRECATED */ {
-                    panic("IOGMD::mapIntoKernel deprecated");
-/* DEPRECATED */ }
+		// Rebase [offset] into the IOPL in order to looks for the first page index.
+		mach_vm_size_t offsetInIOPL = offset - ioplInfo.fIOMDOffset + ioplInfo.fPageOffset;
 
-/*
- * getDirection:
- *
- * Get the direction of the transfer.
- */
-IODirection IOMemoryDescriptor::getDirection() const
-{
-    return _direction;
-}
+		// Retrieve the index of the first page corresponding to the offset.
+		currentPageIndex = atop_32(offsetInIOPL);
+	}
 
-/*
- * getLength:
- *
- * Get the length of the transfer (over all ranges).
- */
-IOByteCount IOMemoryDescriptor::getLength() const
-{
-    return _length;
-}
+	// enter mappings
+	remain  = size;
+	mapAddr = addr;
+	addr    += pageOffset;
 
-void IOMemoryDescriptor::setTag( IOOptionBits tag )
-{
-    _tag = tag;    
-}
+	while (remain && (KERN_SUCCESS == err)) {
+		entryOffset = offset - entry->offset;
+		if ((page_mask & entryOffset) != pageOffset) {
+			err = kIOReturnNotAligned;
+			break;
+		}
 
-IOOptionBits IOMemoryDescriptor::getTag( void )
-{
-    return( _tag);
-}
+		if (kIODefaultCache != cacheMode) {
+			vm_size_t unused = 0;
+			err = mach_make_memory_entry(NULL /*unused*/, &unused, 0 /*unused*/,
+			    memEntryCacheMode, NULL, entry->entry);
+			assert(KERN_SUCCESS == err);
+		}
 
-// @@@ gvdl: who is using this API?  Seems like a wierd thing to implement.
-IOPhysicalAddress
-IOMemoryDescriptor::getSourceSegment( IOByteCount   offset, IOByteCount * length )
-{
-    addr64_t physAddr = 0;
+		entryOffset -= pageOffset;
+		if (entryOffset >= entry->size) {
+			panic("entryOffset");
+		}
+		chunk = entry->size - entryOffset;
+		if (chunk) {
+			vm_map_kernel_flags_t vmk_flags;
+
+			vmk_flags = VM_MAP_KERNEL_FLAGS_NONE;
+			vmk_flags.vmkf_iokit_acct = TRUE; /* iokit accounting */
+
+			if (chunk > remain) {
+				chunk = remain;
+			}
+			if (options & kIOMapPrefault) {
+				UInt nb_pages = round_page(chunk) / PAGE_SIZE;
+
+				err = vm_map_enter_mem_object_prefault(map,
+				    &mapAddr,
+				    chunk, 0 /* mask */,
+				    (VM_FLAGS_FIXED
+				    | VM_FLAGS_OVERWRITE),
+				    vmk_flags,
+				    tag,
+				    entry->entry,
+				    entryOffset,
+				    prot,                        // cur
+				    prot,                        // max
+				    &pageList[currentPageIndex],
+				    nb_pages);
+
+				// Compute the next index in the page list.
+				currentPageIndex += nb_pages;
+				assert(currentPageIndex <= _pages);
+			} else {
+				err = vm_map_enter_mem_object(map,
+				    &mapAddr,
+				    chunk, 0 /* mask */,
+				    (VM_FLAGS_FIXED
+				    | VM_FLAGS_OVERWRITE),
+				    vmk_flags,
+				    tag,
+				    entry->entry,
+				    entryOffset,
+				    false,               // copy
+				    prot,               // cur
+				    prot,               // max
+				    VM_INHERIT_NONE);
+			}
+			if (KERN_SUCCESS != err) {
+				break;
+			}
+			remain -= chunk;
+			if (!remain) {
+				break;
+			}
+			mapAddr  += chunk;
+			offset   += chunk - pageOffset;
+		}
+		pageOffset = 0;
+		entry++;
+		entryIdx++;
+		if (entryIdx >= ref->count) {
+			err = kIOReturnOverrun;
+			break;
+		}
+	}
 
-    if( prepare() == kIOReturnSuccess) {
-        physAddr = getPhysicalSegment64( offset, length );
-        complete();
-    }
+	if ((KERN_SUCCESS != err) && didAlloc) {
+		(void) mach_vm_deallocate(map, trunc_page_64(addr), size);
+		addr = 0;
+	}
+	*inaddr = addr;
 
-    return( (IOPhysicalAddress) physAddr ); // truncated but only page offset is used
+	return err;
 }
 
-IOByteCount IOMemoryDescriptor::readBytes
-                (IOByteCount offset, void *bytes, IOByteCount length)
+IOReturn
+IOGeneralMemoryDescriptor::memoryReferenceGetPageCounts(
+	IOMemoryReference * ref,
+	IOByteCount       * residentPageCount,
+	IOByteCount       * dirtyPageCount)
 {
-    addr64_t dstAddr = (addr64_t) (UInt32) bytes;
-    IOByteCount remaining;
-
-    // Assert that this entire I/O is withing the available range
-    assert(offset < _length);
-    assert(offset + length <= _length);
-    if (offset >= _length) {
-IOLog("IOGMD(%p): rB = o%lx, l%lx\n", this, offset, length);	// @@@ gvdl
-        return 0;
-    }
+	IOReturn        err;
+	IOMemoryEntry * entries;
+	unsigned int resident, dirty;
+	unsigned int totalResident, totalDirty;
 
-    remaining = length = min(length, _length - offset);
-    while (remaining) {	// (process another target segment?)
-        addr64_t	srcAddr64;
-        IOByteCount	srcLen;
+	totalResident = totalDirty = 0;
+	err = kIOReturnSuccess;
+	entries = ref->entries + ref->count;
+	while (entries > &ref->entries[0]) {
+		entries--;
+		err = mach_memory_entry_get_page_counts(entries->entry, &resident, &dirty);
+		if (KERN_SUCCESS != err) {
+			break;
+		}
+		totalResident += resident;
+		totalDirty    += dirty;
+	}
+
+	if (residentPageCount) {
+		*residentPageCount = totalResident;
+	}
+	if (dirtyPageCount) {
+		*dirtyPageCount    = totalDirty;
+	}
+	return err;
+}
+
+IOReturn
+IOGeneralMemoryDescriptor::memoryReferenceSetPurgeable(
+	IOMemoryReference * ref,
+	IOOptionBits        newState,
+	IOOptionBits      * oldState)
+{
+	IOReturn        err;
+	IOMemoryEntry * entries;
+	vm_purgable_t   control;
+	int             totalState, state;
+
+	totalState = kIOMemoryPurgeableNonVolatile;
+	err = kIOReturnSuccess;
+	entries = ref->entries + ref->count;
+	while (entries > &ref->entries[0]) {
+		entries--;
+
+		err = purgeableControlBits(newState, &control, &state);
+		if (KERN_SUCCESS != err) {
+			break;
+		}
+		err = memory_entry_purgeable_control_internal(entries->entry, control, &state);
+		if (KERN_SUCCESS != err) {
+			break;
+		}
+		err = purgeableStateBits(&state);
+		if (KERN_SUCCESS != err) {
+			break;
+		}
+
+		if (kIOMemoryPurgeableEmpty == state) {
+			totalState = kIOMemoryPurgeableEmpty;
+		} else if (kIOMemoryPurgeableEmpty == totalState) {
+			continue;
+		} else if (kIOMemoryPurgeableVolatile == totalState) {
+			continue;
+		} else if (kIOMemoryPurgeableVolatile == state) {
+			totalState = kIOMemoryPurgeableVolatile;
+		} else {
+			totalState = kIOMemoryPurgeableNonVolatile;
+		}
+	}
+
+	if (oldState) {
+		*oldState = totalState;
+	}
+	return err;
+}
+
+IOReturn
+IOGeneralMemoryDescriptor::memoryReferenceSetOwnership(
+	IOMemoryReference * ref,
+	task_t              newOwner,
+	int                 newLedgerTag,
+	IOOptionBits        newLedgerOptions)
+{
+	IOReturn        err, totalErr;
+	IOMemoryEntry * entries;
+
+	totalErr = kIOReturnSuccess;
+	entries = ref->entries + ref->count;
+	while (entries > &ref->entries[0]) {
+		entries--;
+
+		err = mach_memory_entry_ownership(entries->entry, newOwner, newLedgerTag, newLedgerOptions);
+		if (KERN_SUCCESS != err) {
+			totalErr = err;
+		}
+	}
+
+	return totalErr;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withAddress(void *      address,
+    IOByteCount   length,
+    IODirection direction)
+{
+	return IOMemoryDescriptor::
+	       withAddressRange((IOVirtualAddress) address, length, direction | kIOMemoryAutoPrepare, kernel_task);
+}
+
+#ifndef __LP64__
+IOMemoryDescriptor *
+IOMemoryDescriptor::withAddress(IOVirtualAddress address,
+    IOByteCount  length,
+    IODirection  direction,
+    task_t       task)
+{
+	IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
+	if (that) {
+		if (that->initWithAddress(address, length, direction, task)) {
+			return that;
+		}
+
+		that->release();
+	}
+	return NULL;
+}
+#endif /* !__LP64__ */
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withPhysicalAddress(
+	IOPhysicalAddress       address,
+	IOByteCount             length,
+	IODirection             direction )
+{
+	return IOMemoryDescriptor::withAddressRange(address, length, direction, TASK_NULL);
+}
+
+#ifndef __LP64__
+IOMemoryDescriptor *
+IOMemoryDescriptor::withRanges( IOVirtualRange * ranges,
+    UInt32           withCount,
+    IODirection      direction,
+    task_t           task,
+    bool             asReference)
+{
+	IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
+	if (that) {
+		if (that->initWithRanges(ranges, withCount, direction, task, asReference)) {
+			return that;
+		}
+
+		that->release();
+	}
+	return NULL;
+}
+#endif /* !__LP64__ */
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withAddressRange(mach_vm_address_t address,
+    mach_vm_size_t length,
+    IOOptionBits   options,
+    task_t         task)
+{
+	IOAddressRange range = { address, length };
+	return IOMemoryDescriptor::withAddressRanges(&range, 1, options, task);
+}
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withAddressRanges(IOAddressRange *   ranges,
+    UInt32           rangeCount,
+    IOOptionBits     options,
+    task_t           task)
+{
+	IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
+	if (that) {
+		if (task) {
+			options |= kIOMemoryTypeVirtual64;
+		} else {
+			options |= kIOMemoryTypePhysical64;
+		}
+
+		if (that->initWithOptions(ranges, rangeCount, 0, task, options, /* mapper */ NULL)) {
+			return that;
+		}
+
+		that->release();
+	}
+
+	return NULL;
+}
+
+
+/*
+ * withOptions:
+ *
+ * Create a new IOMemoryDescriptor. The buffer is made up of several
+ * virtual address ranges, from a given task.
+ *
+ * Passing the ranges as a reference will avoid an extra allocation.
+ */
+IOMemoryDescriptor *
+IOMemoryDescriptor::withOptions(void *          buffers,
+    UInt32          count,
+    UInt32          offset,
+    task_t          task,
+    IOOptionBits    opts,
+    IOMapper *      mapper)
+{
+	IOGeneralMemoryDescriptor *self = new IOGeneralMemoryDescriptor;
+
+	if (self
+	    && !self->initWithOptions(buffers, count, offset, task, opts, mapper)) {
+		self->release();
+		return NULL;
+	}
+
+	return self;
+}
+
+bool
+IOMemoryDescriptor::initWithOptions(void *         buffers,
+    UInt32         count,
+    UInt32         offset,
+    task_t         task,
+    IOOptionBits   options,
+    IOMapper *     mapper)
+{
+	return false;
+}
+
+#ifndef __LP64__
+IOMemoryDescriptor *
+IOMemoryDescriptor::withPhysicalRanges( IOPhysicalRange * ranges,
+    UInt32          withCount,
+    IODirection     direction,
+    bool            asReference)
+{
+	IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
+	if (that) {
+		if (that->initWithPhysicalRanges(ranges, withCount, direction, asReference)) {
+			return that;
+		}
+
+		that->release();
+	}
+	return NULL;
+}
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withSubRange(IOMemoryDescriptor *   of,
+    IOByteCount             offset,
+    IOByteCount             length,
+    IODirection             direction)
+{
+	return IOSubMemoryDescriptor::withSubRange(of, offset, length, direction);
+}
+#endif /* !__LP64__ */
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withPersistentMemoryDescriptor(IOMemoryDescriptor *originalMD)
+{
+	IOGeneralMemoryDescriptor *origGenMD =
+	    OSDynamicCast(IOGeneralMemoryDescriptor, originalMD);
+
+	if (origGenMD) {
+		return IOGeneralMemoryDescriptor::
+		       withPersistentMemoryDescriptor(origGenMD);
+	} else {
+		return NULL;
+	}
+}
+
+IOMemoryDescriptor *
+IOGeneralMemoryDescriptor::withPersistentMemoryDescriptor(IOGeneralMemoryDescriptor *originalMD)
+{
+	IOMemoryReference * memRef;
+
+	if (kIOReturnSuccess != originalMD->memoryReferenceCreate(kIOMemoryReferenceReuse, &memRef)) {
+		return NULL;
+	}
+
+	if (memRef == originalMD->_memRef) {
+		originalMD->retain();       // Add a new reference to ourselves
+		originalMD->memoryReferenceRelease(memRef);
+		return originalMD;
+	}
+
+	IOGeneralMemoryDescriptor * self = new IOGeneralMemoryDescriptor;
+	IOMDPersistentInitData initData = { originalMD, memRef };
+
+	if (self
+	    && !self->initWithOptions(&initData, 1, 0, NULL, kIOMemoryTypePersistentMD, NULL)) {
+		self->release();
+		self = NULL;
+	}
+	return self;
+}
+
+#ifndef __LP64__
+bool
+IOGeneralMemoryDescriptor::initWithAddress(void *      address,
+    IOByteCount   withLength,
+    IODirection withDirection)
+{
+	_singleRange.v.address = (vm_offset_t) address;
+	_singleRange.v.length  = withLength;
+
+	return initWithRanges(&_singleRange.v, 1, withDirection, kernel_task, true);
+}
+
+bool
+IOGeneralMemoryDescriptor::initWithAddress(IOVirtualAddress address,
+    IOByteCount    withLength,
+    IODirection  withDirection,
+    task_t       withTask)
+{
+	_singleRange.v.address = address;
+	_singleRange.v.length  = withLength;
+
+	return initWithRanges(&_singleRange.v, 1, withDirection, withTask, true);
+}
+
+bool
+IOGeneralMemoryDescriptor::initWithPhysicalAddress(
+	IOPhysicalAddress      address,
+	IOByteCount            withLength,
+	IODirection            withDirection )
+{
+	_singleRange.p.address = address;
+	_singleRange.p.length  = withLength;
+
+	return initWithPhysicalRanges( &_singleRange.p, 1, withDirection, true);
+}
+
+bool
+IOGeneralMemoryDescriptor::initWithPhysicalRanges(
+	IOPhysicalRange * ranges,
+	UInt32            count,
+	IODirection       direction,
+	bool              reference)
+{
+	IOOptionBits mdOpts = direction | kIOMemoryTypePhysical;
+
+	if (reference) {
+		mdOpts |= kIOMemoryAsReference;
+	}
+
+	return initWithOptions(ranges, count, 0, NULL, mdOpts, /* mapper */ NULL);
+}
+
+bool
+IOGeneralMemoryDescriptor::initWithRanges(
+	IOVirtualRange * ranges,
+	UInt32           count,
+	IODirection      direction,
+	task_t           task,
+	bool             reference)
+{
+	IOOptionBits mdOpts = direction;
+
+	if (reference) {
+		mdOpts |= kIOMemoryAsReference;
+	}
+
+	if (task) {
+		mdOpts |= kIOMemoryTypeVirtual;
+
+		// Auto-prepare if this is a kernel memory descriptor as very few
+		// clients bother to prepare() kernel memory.
+		// But it was not enforced so what are you going to do?
+		if (task == kernel_task) {
+			mdOpts |= kIOMemoryAutoPrepare;
+		}
+	} else {
+		mdOpts |= kIOMemoryTypePhysical;
+	}
+
+	return initWithOptions(ranges, count, 0, task, mdOpts, /* mapper */ NULL);
+}
+#endif /* !__LP64__ */
+
+/*
+ * initWithOptions:
+ *
+ *  IOMemoryDescriptor. The buffer is made up of several virtual address ranges,
+ * from a given task, several physical ranges, an UPL from the ubc
+ * system or a uio (may be 64bit) from the BSD subsystem.
+ *
+ * Passing the ranges as a reference will avoid an extra allocation.
+ *
+ * An IOMemoryDescriptor can be re-used by calling initWithOptions again on an
+ * existing instance -- note this behavior is not commonly supported in other
+ * I/O Kit classes, although it is supported here.
+ */
+
+bool
+IOGeneralMemoryDescriptor::initWithOptions(void *       buffers,
+    UInt32       count,
+    UInt32       offset,
+    task_t       task,
+    IOOptionBits options,
+    IOMapper *   mapper)
+{
+	IOOptionBits type = options & kIOMemoryTypeMask;
+
+#ifndef __LP64__
+	if (task
+	    && (kIOMemoryTypeVirtual == type)
+	    && vm_map_is_64bit(get_task_map(task))
+	    && ((IOVirtualRange *) buffers)->address) {
+		OSReportWithBacktrace("IOMemoryDescriptor: attempt to create 32b virtual in 64b task, use ::withAddressRange()");
+		return false;
+	}
+#endif /* !__LP64__ */
+
+	// Grab the original MD's configuation data to initialse the
+	// arguments to this function.
+	if (kIOMemoryTypePersistentMD == type) {
+		IOMDPersistentInitData *initData = (typeof(initData))buffers;
+		const IOGeneralMemoryDescriptor *orig = initData->fMD;
+		ioGMDData *dataP = getDataP(orig->_memoryEntries);
+
+		// Only accept persistent memory descriptors with valid dataP data.
+		assert(orig->_rangesCount == 1);
+		if (!(orig->_flags & kIOMemoryPersistent) || !dataP) {
+			return false;
+		}
+
+		_memRef = initData->fMemRef; // Grab the new named entry
+		options = orig->_flags & ~kIOMemoryAsReference;
+		type = options & kIOMemoryTypeMask;
+		buffers = orig->_ranges.v;
+		count = orig->_rangesCount;
+
+		// Now grab the original task and whatever mapper was previously used
+		task = orig->_task;
+		mapper = dataP->fMapper;
+
+		// We are ready to go through the original initialisation now
+	}
+
+	switch (type) {
+	case kIOMemoryTypeUIO:
+	case kIOMemoryTypeVirtual:
+#ifndef __LP64__
+	case kIOMemoryTypeVirtual64:
+#endif /* !__LP64__ */
+		assert(task);
+		if (!task) {
+			return false;
+		}
+		break;
+
+	case kIOMemoryTypePhysical:     // Neither Physical nor UPL should have a task
+#ifndef __LP64__
+	case kIOMemoryTypePhysical64:
+#endif /* !__LP64__ */
+	case kIOMemoryTypeUPL:
+		assert(!task);
+		break;
+	default:
+		return false; /* bad argument */
+	}
+
+	assert(buffers);
+	assert(count);
+
+	/*
+	 * We can check the _initialized  instance variable before having ever set
+	 * it to an initial value because I/O Kit guarantees that all our instance
+	 * variables are zeroed on an object's allocation.
+	 */
+
+	if (_initialized) {
+		/*
+		 * An existing memory descriptor is being retargeted to point to
+		 * somewhere else.  Clean up our present state.
+		 */
+		IOOptionBits type = _flags & kIOMemoryTypeMask;
+		if ((kIOMemoryTypePhysical != type) && (kIOMemoryTypePhysical64 != type)) {
+			while (_wireCount) {
+				complete();
+			}
+		}
+		if (_ranges.v && !(kIOMemoryAsReference & _flags)) {
+			if (kIOMemoryTypeUIO == type) {
+				uio_free((uio_t) _ranges.v);
+			}
+#ifndef __LP64__
+			else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type)) {
+				IODelete(_ranges.v64, IOAddressRange, _rangesCount);
+			}
+#endif /* !__LP64__ */
+			else {
+				IODelete(_ranges.v, IOVirtualRange, _rangesCount);
+			}
+		}
+
+		options |= (kIOMemoryRedirected & _flags);
+		if (!(kIOMemoryRedirected & options)) {
+			if (_memRef) {
+				memoryReferenceRelease(_memRef);
+				_memRef = NULL;
+			}
+			if (_mappings) {
+				_mappings->flushCollection();
+			}
+		}
+	} else {
+		if (!super::init()) {
+			return false;
+		}
+		_initialized = true;
+	}
+
+	// Grab the appropriate mapper
+	if (kIOMemoryHostOrRemote & options) {
+		options |= kIOMemoryMapperNone;
+	}
+	if (kIOMemoryMapperNone & options) {
+		mapper = NULL; // No Mapper
+	} else if (mapper == kIOMapperSystem) {
+		IOMapper::checkForSystemMapper();
+		gIOSystemMapper = mapper = IOMapper::gSystem;
+	}
+
+	// Remove the dynamic internal use flags from the initial setting
+	options               &= ~(kIOMemoryPreparedReadOnly);
+	_flags                 = options;
+	_task                  = task;
+
+#ifndef __LP64__
+	_direction             = (IODirection) (_flags & kIOMemoryDirectionMask);
+#endif /* !__LP64__ */
+
+	_dmaReferences = 0;
+	__iomd_reservedA = 0;
+	__iomd_reservedB = 0;
+	_highestPage = 0;
+
+	if (kIOMemoryThreadSafe & options) {
+		if (!_prepareLock) {
+			_prepareLock = IOLockAlloc();
+		}
+	} else if (_prepareLock) {
+		IOLockFree(_prepareLock);
+		_prepareLock = NULL;
+	}
+
+	if (kIOMemoryTypeUPL == type) {
+		ioGMDData *dataP;
+		unsigned int dataSize = computeDataSize(/* pages */ 0, /* upls */ 1);
+
+		if (!initMemoryEntries(dataSize, mapper)) {
+			return false;
+		}
+		dataP = getDataP(_memoryEntries);
+		dataP->fPageCnt = 0;
+		switch (kIOMemoryDirectionMask & options) {
+		case kIODirectionOut:
+			dataP->fDMAAccess = kIODMAMapReadAccess;
+			break;
+		case kIODirectionIn:
+			dataP->fDMAAccess = kIODMAMapWriteAccess;
+			break;
+		case kIODirectionNone:
+		case kIODirectionOutIn:
+		default:
+			panic("bad dir for upl 0x%x\n", (int) options);
+			break;
+		}
+		//       _wireCount++;	// UPLs start out life wired
+
+		_length    = count;
+		_pages    += atop_32(offset + count + PAGE_MASK) - atop_32(offset);
+
+		ioPLBlock iopl;
+		iopl.fIOPL = (upl_t) buffers;
+		upl_set_referenced(iopl.fIOPL, true);
+		upl_page_info_t *pageList = UPL_GET_INTERNAL_PAGE_LIST(iopl.fIOPL);
+
+		if (upl_get_size(iopl.fIOPL) < (count + offset)) {
+			panic("short external upl");
+		}
+
+		_highestPage = upl_get_highest_page(iopl.fIOPL);
+
+		// Set the flag kIOPLOnDevice convieniently equal to 1
+		iopl.fFlags  = pageList->device | kIOPLExternUPL;
+		if (!pageList->device) {
+			// Pre-compute the offset into the UPL's page list
+			pageList = &pageList[atop_32(offset)];
+			offset &= PAGE_MASK;
+		}
+		iopl.fIOMDOffset = 0;
+		iopl.fMappedPage = 0;
+		iopl.fPageInfo = (vm_address_t) pageList;
+		iopl.fPageOffset = offset;
+		_memoryEntries->appendBytes(&iopl, sizeof(iopl));
+	} else {
+		// kIOMemoryTypeVirtual  | kIOMemoryTypeVirtual64 | kIOMemoryTypeUIO
+		// kIOMemoryTypePhysical | kIOMemoryTypePhysical64
+
+		// Initialize the memory descriptor
+		if (options & kIOMemoryAsReference) {
+#ifndef __LP64__
+			_rangesIsAllocated = false;
+#endif /* !__LP64__ */
+
+			// Hack assignment to get the buffer arg into _ranges.
+			// I'd prefer to do _ranges = (Ranges) buffers, but that doesn't
+			// work, C++ sigh.
+			// This also initialises the uio & physical ranges.
+			_ranges.v = (IOVirtualRange *) buffers;
+		} else {
+#ifndef __LP64__
+			_rangesIsAllocated = true;
+#endif /* !__LP64__ */
+			switch (type) {
+			case kIOMemoryTypeUIO:
+				_ranges.v = (IOVirtualRange *) uio_duplicate((uio_t) buffers);
+				break;
+
+#ifndef __LP64__
+			case kIOMemoryTypeVirtual64:
+			case kIOMemoryTypePhysical64:
+				if (count == 1
+#ifndef __arm__
+				    && (((IOAddressRange *) buffers)->address + ((IOAddressRange *) buffers)->length) <= 0x100000000ULL
+#endif
+				    ) {
+					if (kIOMemoryTypeVirtual64 == type) {
+						type = kIOMemoryTypeVirtual;
+					} else {
+						type = kIOMemoryTypePhysical;
+					}
+					_flags = (_flags & ~kIOMemoryTypeMask) | type | kIOMemoryAsReference;
+					_rangesIsAllocated = false;
+					_ranges.v = &_singleRange.v;
+					_singleRange.v.address = ((IOAddressRange *) buffers)->address;
+					_singleRange.v.length  = ((IOAddressRange *) buffers)->length;
+					break;
+				}
+				_ranges.v64 = IONew(IOAddressRange, count);
+				if (!_ranges.v64) {
+					return false;
+				}
+				bcopy(buffers, _ranges.v, count * sizeof(IOAddressRange));
+				break;
+#endif /* !__LP64__ */
+			case kIOMemoryTypeVirtual:
+			case kIOMemoryTypePhysical:
+				if (count == 1) {
+					_flags |= kIOMemoryAsReference;
+#ifndef __LP64__
+					_rangesIsAllocated = false;
+#endif /* !__LP64__ */
+					_ranges.v = &_singleRange.v;
+				} else {
+					_ranges.v = IONew(IOVirtualRange, count);
+					if (!_ranges.v) {
+						return false;
+					}
+				}
+				bcopy(buffers, _ranges.v, count * sizeof(IOVirtualRange));
+				break;
+			}
+		}
+		_rangesCount = count;
+
+		// Find starting address within the vector of ranges
+		Ranges vec = _ranges;
+		mach_vm_size_t totalLength = 0;
+		unsigned int ind, pages = 0;
+		for (ind = 0; ind < count; ind++) {
+			mach_vm_address_t addr;
+			mach_vm_address_t endAddr;
+			mach_vm_size_t    len;
+
+			// addr & len are returned by this function
+			getAddrLenForInd(addr, len, type, vec, ind);
+			if (os_add3_overflow(addr, len, PAGE_MASK, &endAddr)) {
+				break;
+			}
+			if (os_add_overflow(pages, (atop_64(endAddr) - atop_64(addr)), &pages)) {
+				break;
+			}
+			if (os_add_overflow(totalLength, len, &totalLength)) {
+				break;
+			}
+			if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type)) {
+				ppnum_t highPage = atop_64(addr + len - 1);
+				if (highPage > _highestPage) {
+					_highestPage = highPage;
+				}
+			}
+		}
+		if ((ind < count)
+		    || (totalLength != ((IOByteCount) totalLength))) {
+			return false;                                   /* overflow */
+		}
+		_length      = totalLength;
+		_pages       = pages;
+
+		// Auto-prepare memory at creation time.
+		// Implied completion when descriptor is free-ed
+
+
+		if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type)) {
+			_wireCount++; // Physical MDs are, by definition, wired
+		} else { /* kIOMemoryTypeVirtual | kIOMemoryTypeVirtual64 | kIOMemoryTypeUIO */
+			ioGMDData *dataP;
+			unsigned dataSize;
+
+			if (_pages > atop_64(max_mem)) {
+				return false;
+			}
+
+			dataSize = computeDataSize(_pages, /* upls */ count * 2);
+			if (!initMemoryEntries(dataSize, mapper)) {
+				return false;
+			}
+			dataP = getDataP(_memoryEntries);
+			dataP->fPageCnt = _pages;
+
+			if (((_task != kernel_task) || (kIOMemoryBufferPageable & _flags))
+			    && (VM_KERN_MEMORY_NONE == _kernelTag)) {
+				_kernelTag = IOMemoryTag(kernel_map);
+				if (_kernelTag == gIOSurfaceTag) {
+					_userTag = VM_MEMORY_IOSURFACE;
+				}
+			}
+
+			if ((kIOMemoryPersistent & _flags) && !_memRef) {
+				IOReturn
+				    err = memoryReferenceCreate(0, &_memRef);
+				if (kIOReturnSuccess != err) {
+					return false;
+				}
+			}
+
+			if ((_flags & kIOMemoryAutoPrepare)
+			    && prepare() != kIOReturnSuccess) {
+				return false;
+			}
+		}
+	}
+
+	return true;
+}
+
+/*
+ * free
+ *
+ * Free resources.
+ */
+void
+IOGeneralMemoryDescriptor::free()
+{
+	IOOptionBits type = _flags & kIOMemoryTypeMask;
+
+	if (reserved) {
+		LOCK;
+		reserved->dp.memory = NULL;
+		UNLOCK;
+	}
+	if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type)) {
+		ioGMDData * dataP;
+		if (_memoryEntries && (dataP = getDataP(_memoryEntries)) && dataP->fMappedBaseValid) {
+			dmaUnmap(dataP->fMapper, NULL, 0, dataP->fMappedBase, dataP->fMappedLength);
+			dataP->fMappedBaseValid = dataP->fMappedBase = 0;
+		}
+	} else {
+		while (_wireCount) {
+			complete();
+		}
+	}
+
+	if (_memoryEntries) {
+		_memoryEntries->release();
+	}
+
+	if (_ranges.v && !(kIOMemoryAsReference & _flags)) {
+		if (kIOMemoryTypeUIO == type) {
+			uio_free((uio_t) _ranges.v);
+		}
+#ifndef __LP64__
+		else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type)) {
+			IODelete(_ranges.v64, IOAddressRange, _rangesCount);
+		}
+#endif /* !__LP64__ */
+		else {
+			IODelete(_ranges.v, IOVirtualRange, _rangesCount);
+		}
+
+		_ranges.v = NULL;
+	}
+
+	if (reserved) {
+		cleanKernelReserved(reserved);
+		if (reserved->dp.devicePager) {
+			// memEntry holds a ref on the device pager which owns reserved
+			// (IOMemoryDescriptorReserved) so no reserved access after this point
+			device_pager_deallocate((memory_object_t) reserved->dp.devicePager );
+		} else {
+			IODelete(reserved, IOMemoryDescriptorReserved, 1);
+		}
+		reserved = NULL;
+	}
+
+	if (_memRef) {
+		memoryReferenceRelease(_memRef);
+	}
+	if (_prepareLock) {
+		IOLockFree(_prepareLock);
+	}
+
+	super::free();
+}
+
+#ifndef __LP64__
+void
+IOGeneralMemoryDescriptor::unmapFromKernel()
+{
+	panic("IOGMD::unmapFromKernel deprecated");
+}
+
+void
+IOGeneralMemoryDescriptor::mapIntoKernel(unsigned rangeIndex)
+{
+	panic("IOGMD::mapIntoKernel deprecated");
+}
+#endif /* !__LP64__ */
+
+/*
+ * getDirection:
+ *
+ * Get the direction of the transfer.
+ */
+IODirection
+IOMemoryDescriptor::getDirection() const
+{
+#ifndef __LP64__
+	if (_direction) {
+		return _direction;
+	}
+#endif /* !__LP64__ */
+	return (IODirection) (_flags & kIOMemoryDirectionMask);
+}
+
+/*
+ * getLength:
+ *
+ * Get the length of the transfer (over all ranges).
+ */
+IOByteCount
+IOMemoryDescriptor::getLength() const
+{
+	return _length;
+}
+
+void
+IOMemoryDescriptor::setTag( IOOptionBits tag )
+{
+	_tag = tag;
+}
+
+IOOptionBits
+IOMemoryDescriptor::getTag( void )
+{
+	return _tag;
+}
+
+uint64_t
+IOMemoryDescriptor::getFlags(void)
+{
+	return _flags;
+}
+
+#ifndef __LP64__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+
+// @@@ gvdl: who is using this API?  Seems like a wierd thing to implement.
+IOPhysicalAddress
+IOMemoryDescriptor::getSourceSegment( IOByteCount   offset, IOByteCount * length )
+{
+	addr64_t physAddr = 0;
+
+	if (prepare() == kIOReturnSuccess) {
+		physAddr = getPhysicalSegment64( offset, length );
+		complete();
+	}
+
+	return (IOPhysicalAddress) physAddr; // truncated but only page offset is used
+}
+
+#pragma clang diagnostic pop
+
+#endif /* !__LP64__ */
+
+IOByteCount
+IOMemoryDescriptor::readBytes
+(IOByteCount offset, void *bytes, IOByteCount length)
+{
+	addr64_t dstAddr = CAST_DOWN(addr64_t, bytes);
+	IOByteCount remaining;
+
+	// Assert that this entire I/O is withing the available range
+	assert(offset <= _length);
+	assert(offset + length <= _length);
+	if ((offset >= _length)
+	    || ((offset + length) > _length)) {
+		return 0;
+	}
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return 0;
+	}
+
+	if (kIOMemoryThreadSafe & _flags) {
+		LOCK;
+	}
+
+	remaining = length = min(length, _length - offset);
+	while (remaining) { // (process another target segment?)
+		addr64_t        srcAddr64;
+		IOByteCount     srcLen;
+
+		srcAddr64 = getPhysicalSegment(offset, &srcLen, kIOMemoryMapperNone);
+		if (!srcAddr64) {
+			break;
+		}
+
+		// Clip segment length to remaining
+		if (srcLen > remaining) {
+			srcLen = remaining;
+		}
+
+		copypv(srcAddr64, dstAddr, srcLen,
+		    cppvPsrc | cppvNoRefSrc | cppvFsnk | cppvKmap);
+
+		dstAddr   += srcLen;
+		offset    += srcLen;
+		remaining -= srcLen;
+	}
+
+	if (kIOMemoryThreadSafe & _flags) {
+		UNLOCK;
+	}
+
+	assert(!remaining);
+
+	return length - remaining;
+}
+
+IOByteCount
+IOMemoryDescriptor::writeBytes
+(IOByteCount inoffset, const void *bytes, IOByteCount length)
+{
+	addr64_t srcAddr = CAST_DOWN(addr64_t, bytes);
+	IOByteCount remaining;
+	IOByteCount offset = inoffset;
+
+	// Assert that this entire I/O is withing the available range
+	assert(offset <= _length);
+	assert(offset + length <= _length);
+
+	assert( !(kIOMemoryPreparedReadOnly & _flags));
+
+	if ((kIOMemoryPreparedReadOnly & _flags)
+	    || (offset >= _length)
+	    || ((offset + length) > _length)) {
+		return 0;
+	}
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return 0;
+	}
+
+	if (kIOMemoryThreadSafe & _flags) {
+		LOCK;
+	}
+
+	remaining = length = min(length, _length - offset);
+	while (remaining) { // (process another target segment?)
+		addr64_t    dstAddr64;
+		IOByteCount dstLen;
+
+		dstAddr64 = getPhysicalSegment(offset, &dstLen, kIOMemoryMapperNone);
+		if (!dstAddr64) {
+			break;
+		}
+
+		// Clip segment length to remaining
+		if (dstLen > remaining) {
+			dstLen = remaining;
+		}
+
+		if (!srcAddr) {
+			bzero_phys(dstAddr64, dstLen);
+		} else {
+			copypv(srcAddr, (addr64_t) dstAddr64, dstLen,
+			    cppvPsnk | cppvFsnk | cppvNoRefSrc | cppvNoModSnk | cppvKmap);
+			srcAddr   += dstLen;
+		}
+		offset    += dstLen;
+		remaining -= dstLen;
+	}
+
+	if (kIOMemoryThreadSafe & _flags) {
+		UNLOCK;
+	}
+
+	assert(!remaining);
+
+#if defined(__x86_64__)
+	// copypv does not cppvFsnk on intel
+#else
+	if (!srcAddr) {
+		performOperation(kIOMemoryIncoherentIOFlush, inoffset, length);
+	}
+#endif
+
+	return length - remaining;
+}
+
+#ifndef __LP64__
+void
+IOGeneralMemoryDescriptor::setPosition(IOByteCount position)
+{
+	panic("IOGMD::setPosition deprecated");
+}
+#endif /* !__LP64__ */
+
+static volatile SInt64 gIOMDPreparationID __attribute__((aligned(8))) = (1ULL << 32);
+
+uint64_t
+IOGeneralMemoryDescriptor::getPreparationID( void )
+{
+	ioGMDData *dataP;
+
+	if (!_wireCount) {
+		return kIOPreparationIDUnprepared;
+	}
+
+	if (((kIOMemoryTypeMask & _flags) == kIOMemoryTypePhysical)
+	    || ((kIOMemoryTypeMask & _flags) == kIOMemoryTypePhysical64)) {
+		IOMemoryDescriptor::setPreparationID();
+		return IOMemoryDescriptor::getPreparationID();
+	}
+
+	if (!_memoryEntries || !(dataP = getDataP(_memoryEntries))) {
+		return kIOPreparationIDUnprepared;
+	}
+
+	if (kIOPreparationIDUnprepared == dataP->fPreparationID) {
+		SInt64 newID = OSIncrementAtomic64(&gIOMDPreparationID);
+		OSCompareAndSwap64(kIOPreparationIDUnprepared, newID, &dataP->fPreparationID);
+	}
+	return dataP->fPreparationID;
+}
+
+void
+IOMemoryDescriptor::cleanKernelReserved( IOMemoryDescriptorReserved * reserved )
+{
+	if (reserved->creator) {
+		task_deallocate(reserved->creator);
+		reserved->creator = NULL;
+	}
+}
+
+IOMemoryDescriptorReserved *
+IOMemoryDescriptor::getKernelReserved( void )
+{
+	if (!reserved) {
+		reserved = IONewZero(IOMemoryDescriptorReserved, 1);
+	}
+	return reserved;
+}
+
+void
+IOMemoryDescriptor::setPreparationID( void )
+{
+	if (getKernelReserved() && (kIOPreparationIDUnprepared == reserved->preparationID)) {
+		SInt64 newID = OSIncrementAtomic64(&gIOMDPreparationID);
+		OSCompareAndSwap64(kIOPreparationIDUnprepared, newID, &reserved->preparationID);
+	}
+}
+
+uint64_t
+IOMemoryDescriptor::getPreparationID( void )
+{
+	if (reserved) {
+		return reserved->preparationID;
+	} else {
+		return kIOPreparationIDUnsupported;
+	}
+}
+
+void
+IOMemoryDescriptor::setVMTags(uint32_t kernelTag, uint32_t userTag)
+{
+	_kernelTag = (vm_tag_t) kernelTag;
+	_userTag   = (vm_tag_t) userTag;
+}
+
+uint32_t
+IOMemoryDescriptor::getVMTag(vm_map_t map)
+{
+	if (vm_kernel_map_is_kernel(map)) {
+		if (VM_KERN_MEMORY_NONE != _kernelTag) {
+			return (uint32_t) _kernelTag;
+		}
+	} else {
+		if (VM_KERN_MEMORY_NONE != _userTag) {
+			return (uint32_t) _userTag;
+		}
+	}
+	return IOMemoryTag(map);
+}
+
+IOReturn
+IOGeneralMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
+{
+	IOReturn err = kIOReturnSuccess;
+	DMACommandOps params;
+	IOGeneralMemoryDescriptor * md = const_cast<IOGeneralMemoryDescriptor *>(this);
+	ioGMDData *dataP;
+
+	params = (op & ~kIOMDDMACommandOperationMask & op);
+	op &= kIOMDDMACommandOperationMask;
+
+	if (kIOMDDMAMap == op) {
+		if (dataSize < sizeof(IOMDDMAMapArgs)) {
+			return kIOReturnUnderrun;
+		}
+
+		IOMDDMAMapArgs * data = (IOMDDMAMapArgs *) vData;
+
+		if (!_memoryEntries
+		    && !md->initMemoryEntries(computeDataSize(0, 0), kIOMapperWaitSystem)) {
+			return kIOReturnNoMemory;
+		}
+
+		if (_memoryEntries && data->fMapper) {
+			bool remap, keepMap;
+			dataP = getDataP(_memoryEntries);
+
+			if (data->fMapSpec.numAddressBits < dataP->fDMAMapNumAddressBits) {
+				dataP->fDMAMapNumAddressBits = data->fMapSpec.numAddressBits;
+			}
+			if (data->fMapSpec.alignment > dataP->fDMAMapAlignment) {
+				dataP->fDMAMapAlignment      = data->fMapSpec.alignment;
+			}
+
+			keepMap = (data->fMapper == gIOSystemMapper);
+			keepMap &= ((data->fOffset == 0) && (data->fLength == _length));
+
+			if ((data->fMapper == gIOSystemMapper) && _prepareLock) {
+				IOLockLock(_prepareLock);
+			}
+
+			remap = (!keepMap);
+			remap |= (dataP->fDMAMapNumAddressBits < 64)
+			    && ((dataP->fMappedBase + _length) > (1ULL << dataP->fDMAMapNumAddressBits));
+			remap |= (dataP->fDMAMapAlignment > page_size);
+
+			if (remap || !dataP->fMappedBaseValid) {
+//		if (dataP->fMappedBaseValid) OSReportWithBacktrace("kIOMDDMAMap whole %d remap %d params %d\n", whole, remap, params);
+				err = md->dmaMap(data->fMapper, data->fCommand, &data->fMapSpec, data->fOffset, data->fLength, &data->fAlloc, &data->fAllocLength);
+				if (keepMap && (kIOReturnSuccess == err) && !dataP->fMappedBaseValid) {
+					dataP->fMappedBase      = data->fAlloc;
+					dataP->fMappedBaseValid = true;
+					dataP->fMappedLength    = data->fAllocLength;
+					data->fAllocLength      = 0;    // IOMD owns the alloc now
+				}
+			} else {
+				data->fAlloc = dataP->fMappedBase;
+				data->fAllocLength = 0;         // give out IOMD map
+				md->dmaMapRecord(data->fMapper, data->fCommand, dataP->fMappedLength);
+			}
+			data->fMapContig = !dataP->fDiscontig;
+
+			if ((data->fMapper == gIOSystemMapper) && _prepareLock) {
+				IOLockUnlock(_prepareLock);
+			}
+		}
+		return err;
+	}
+	if (kIOMDDMAUnmap == op) {
+		if (dataSize < sizeof(IOMDDMAMapArgs)) {
+			return kIOReturnUnderrun;
+		}
+		IOMDDMAMapArgs * data = (IOMDDMAMapArgs *) vData;
+
+		err = md->dmaUnmap(data->fMapper, data->fCommand, data->fOffset, data->fAlloc, data->fAllocLength);
+
+		return kIOReturnSuccess;
+	}
+
+	if (kIOMDAddDMAMapSpec == op) {
+		if (dataSize < sizeof(IODMAMapSpecification)) {
+			return kIOReturnUnderrun;
+		}
+
+		IODMAMapSpecification * data = (IODMAMapSpecification *) vData;
+
+		if (!_memoryEntries
+		    && !md->initMemoryEntries(computeDataSize(0, 0), kIOMapperWaitSystem)) {
+			return kIOReturnNoMemory;
+		}
+
+		if (_memoryEntries) {
+			dataP = getDataP(_memoryEntries);
+			if (data->numAddressBits < dataP->fDMAMapNumAddressBits) {
+				dataP->fDMAMapNumAddressBits = data->numAddressBits;
+			}
+			if (data->alignment > dataP->fDMAMapAlignment) {
+				dataP->fDMAMapAlignment = data->alignment;
+			}
+		}
+		return kIOReturnSuccess;
+	}
+
+	if (kIOMDGetCharacteristics == op) {
+		if (dataSize < sizeof(IOMDDMACharacteristics)) {
+			return kIOReturnUnderrun;
+		}
+
+		IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
+		data->fLength = _length;
+		data->fSGCount = _rangesCount;
+		data->fPages = _pages;
+		data->fDirection = getDirection();
+		if (!_wireCount) {
+			data->fIsPrepared = false;
+		} else {
+			data->fIsPrepared = true;
+			data->fHighestPage = _highestPage;
+			if (_memoryEntries) {
+				dataP = getDataP(_memoryEntries);
+				ioPLBlock *ioplList = getIOPLList(dataP);
+				UInt count = getNumIOPL(_memoryEntries, dataP);
+				if (count == 1) {
+					data->fPageAlign = (ioplList[0].fPageOffset & PAGE_MASK) | ~PAGE_MASK;
+				}
+			}
+		}
+
+		return kIOReturnSuccess;
+	} else if (kIOMDDMAActive == op) {
+		if (params) {
+			int16_t prior;
+			prior = OSAddAtomic16(1, &md->_dmaReferences);
+			if (!prior) {
+				md->_mapName = NULL;
+			}
+		} else {
+			if (md->_dmaReferences) {
+				OSAddAtomic16(-1, &md->_dmaReferences);
+			} else {
+				panic("_dmaReferences underflow");
+			}
+		}
+	} else if (kIOMDWalkSegments != op) {
+		return kIOReturnBadArgument;
+	}
+
+	// Get the next segment
+	struct InternalState {
+		IOMDDMAWalkSegmentArgs fIO;
+		mach_vm_size_t fOffset2Index;
+		mach_vm_size_t fNextOffset;
+		UInt fIndex;
+	} *isP;
+
+	// Find the next segment
+	if (dataSize < sizeof(*isP)) {
+		return kIOReturnUnderrun;
+	}
+
+	isP = (InternalState *) vData;
+	mach_vm_size_t offset = isP->fIO.fOffset;
+	uint8_t mapped = isP->fIO.fMapped;
+	uint64_t mappedBase;
+
+	if (mapped && (kIOMemoryRemote & _flags)) {
+		return kIOReturnNotAttached;
+	}
+
+	if (IOMapper::gSystem && mapped
+	    && (!(kIOMemoryHostOnly & _flags))
+	    && (!_memoryEntries || !getDataP(_memoryEntries)->fMappedBaseValid)) {
+//	&& (_memoryEntries && !getDataP(_memoryEntries)->fMappedBaseValid))
+		if (!_memoryEntries
+		    && !md->initMemoryEntries(computeDataSize(0, 0), kIOMapperWaitSystem)) {
+			return kIOReturnNoMemory;
+		}
+
+		dataP = getDataP(_memoryEntries);
+		if (dataP->fMapper) {
+			IODMAMapSpecification mapSpec;
+			bzero(&mapSpec, sizeof(mapSpec));
+			mapSpec.numAddressBits = dataP->fDMAMapNumAddressBits;
+			mapSpec.alignment = dataP->fDMAMapAlignment;
+			err = md->dmaMap(dataP->fMapper, NULL, &mapSpec, 0, _length, &dataP->fMappedBase, &dataP->fMappedLength);
+			if (kIOReturnSuccess != err) {
+				return err;
+			}
+			dataP->fMappedBaseValid = true;
+		}
+	}
+
+	if (kIOMDDMAWalkMappedLocal == mapped) {
+		mappedBase = isP->fIO.fMappedBase;
+	} else if (mapped) {
+		if (IOMapper::gSystem
+		    && (!(kIOMemoryHostOnly & _flags))
+		    && _memoryEntries
+		    && (dataP = getDataP(_memoryEntries))
+		    && dataP->fMappedBaseValid) {
+			mappedBase = dataP->fMappedBase;
+		} else {
+			mapped = 0;
+		}
+	}
+
+	if (offset >= _length) {
+		return (offset == _length)? kIOReturnOverrun : kIOReturnInternalError;
+	}
+
+	// Validate the previous offset
+	UInt ind;
+	mach_vm_size_t off2Ind = isP->fOffset2Index;
+	if (!params
+	    && offset
+	    && (offset == isP->fNextOffset || off2Ind <= offset)) {
+		ind = isP->fIndex;
+	} else {
+		ind = off2Ind = 0; // Start from beginning
+	}
+	mach_vm_size_t length;
+	UInt64 address;
+
+	if ((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical) {
+		// Physical address based memory descriptor
+		const IOPhysicalRange *physP = (IOPhysicalRange *) &_ranges.p[0];
+
+		// Find the range after the one that contains the offset
+		mach_vm_size_t len;
+		for (len = 0; off2Ind <= offset; ind++) {
+			len = physP[ind].length;
+			off2Ind += len;
+		}
+
+		// Calculate length within range and starting address
+		length   = off2Ind - offset;
+		address  = physP[ind - 1].address + len - length;
+
+		if (true && mapped) {
+			address = mappedBase + offset;
+		} else {
+			// see how far we can coalesce ranges
+			while (ind < _rangesCount && address + length == physP[ind].address) {
+				len = physP[ind].length;
+				length += len;
+				off2Ind += len;
+				ind++;
+			}
+		}
+
+		// correct contiguous check overshoot
+		ind--;
+		off2Ind -= len;
+	}
+#ifndef __LP64__
+	else if ((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64) {
+		// Physical address based memory descriptor
+		const IOAddressRange *physP = (IOAddressRange *) &_ranges.v64[0];
+
+		// Find the range after the one that contains the offset
+		mach_vm_size_t len;
+		for (len = 0; off2Ind <= offset; ind++) {
+			len = physP[ind].length;
+			off2Ind += len;
+		}
+
+		// Calculate length within range and starting address
+		length   = off2Ind - offset;
+		address  = physP[ind - 1].address + len - length;
+
+		if (true && mapped) {
+			address = mappedBase + offset;
+		} else {
+			// see how far we can coalesce ranges
+			while (ind < _rangesCount && address + length == physP[ind].address) {
+				len = physP[ind].length;
+				length += len;
+				off2Ind += len;
+				ind++;
+			}
+		}
+		// correct contiguous check overshoot
+		ind--;
+		off2Ind -= len;
+	}
+#endif /* !__LP64__ */
+	else {
+		do {
+			if (!_wireCount) {
+				panic("IOGMD: not wired for the IODMACommand");
+			}
+
+			assert(_memoryEntries);
+
+			dataP = getDataP(_memoryEntries);
+			const ioPLBlock *ioplList = getIOPLList(dataP);
+			UInt numIOPLs = getNumIOPL(_memoryEntries, dataP);
+			upl_page_info_t *pageList = getPageList(dataP);
+
+			assert(numIOPLs > 0);
+
+			// Scan through iopl info blocks looking for block containing offset
+			while (ind < numIOPLs && offset >= ioplList[ind].fIOMDOffset) {
+				ind++;
+			}
+
+			// Go back to actual range as search goes past it
+			ioPLBlock ioplInfo = ioplList[ind - 1];
+			off2Ind = ioplInfo.fIOMDOffset;
+
+			if (ind < numIOPLs) {
+				length = ioplList[ind].fIOMDOffset;
+			} else {
+				length = _length;
+			}
+			length -= offset;       // Remainder within iopl
+
+			// Subtract offset till this iopl in total list
+			offset -= off2Ind;
+
+			// If a mapped address is requested and this is a pre-mapped IOPL
+			// then just need to compute an offset relative to the mapped base.
+			if (mapped) {
+				offset += (ioplInfo.fPageOffset & PAGE_MASK);
+				address = trunc_page_64(mappedBase) + ptoa_64(ioplInfo.fMappedPage) + offset;
+				continue; // Done leave do/while(false) now
+			}
+
+			// The offset is rebased into the current iopl.
+			// Now add the iopl 1st page offset.
+			offset += ioplInfo.fPageOffset;
+
+			// For external UPLs the fPageInfo field points directly to
+			// the upl's upl_page_info_t array.
+			if (ioplInfo.fFlags & kIOPLExternUPL) {
+				pageList = (upl_page_info_t *) ioplInfo.fPageInfo;
+			} else {
+				pageList = &pageList[ioplInfo.fPageInfo];
+			}
+
+			// Check for direct device non-paged memory
+			if (ioplInfo.fFlags & kIOPLOnDevice) {
+				address = ptoa_64(pageList->phys_addr) + offset;
+				continue; // Done leave do/while(false) now
+			}
+
+			// Now we need compute the index into the pageList
+			UInt pageInd = atop_32(offset);
+			offset &= PAGE_MASK;
+
+			// Compute the starting address of this segment
+			IOPhysicalAddress pageAddr = pageList[pageInd].phys_addr;
+			if (!pageAddr) {
+				panic("!pageList phys_addr");
+			}
+
+			address = ptoa_64(pageAddr) + offset;
+
+			// length is currently set to the length of the remainider of the iopl.
+			// We need to check that the remainder of the iopl is contiguous.
+			// This is indicated by pageList[ind].phys_addr being sequential.
+			IOByteCount contigLength = PAGE_SIZE - offset;
+			while (contigLength < length
+			    && ++pageAddr == pageList[++pageInd].phys_addr) {
+				contigLength += PAGE_SIZE;
+			}
+
+			if (contigLength < length) {
+				length = contigLength;
+			}
+
+
+			assert(address);
+			assert(length);
+		} while (false);
+	}
+
+	// Update return values and state
+	isP->fIO.fIOVMAddr = address;
+	isP->fIO.fLength   = length;
+	isP->fIndex        = ind;
+	isP->fOffset2Index = off2Ind;
+	isP->fNextOffset   = isP->fIO.fOffset + length;
+
+	return kIOReturnSuccess;
+}
+
+addr64_t
+IOGeneralMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount *lengthOfSegment, IOOptionBits options)
+{
+	IOReturn          ret;
+	mach_vm_address_t address = 0;
+	mach_vm_size_t    length  = 0;
+	IOMapper *        mapper  = gIOSystemMapper;
+	IOOptionBits      type    = _flags & kIOMemoryTypeMask;
+
+	if (lengthOfSegment) {
+		*lengthOfSegment = 0;
+	}
+
+	if (offset >= _length) {
+		return 0;
+	}
+
+	// IOMemoryDescriptor::doMap() cannot use getPhysicalSegment() to obtain the page offset, since it must
+	// support the unwired memory case in IOGeneralMemoryDescriptor, and hibernate_write_image() cannot use
+	// map()->getVirtualAddress() to obtain the kernel pointer, since it must prevent the memory allocation
+	// due to IOMemoryMap, so _kIOMemorySourceSegment is a necessary evil until all of this gets cleaned up
+
+	if ((options & _kIOMemorySourceSegment) && (kIOMemoryTypeUPL != type)) {
+		unsigned rangesIndex = 0;
+		Ranges vec = _ranges;
+		mach_vm_address_t addr;
+
+		// Find starting address within the vector of ranges
+		for (;;) {
+			getAddrLenForInd(addr, length, type, vec, rangesIndex);
+			if (offset < length) {
+				break;
+			}
+			offset -= length; // (make offset relative)
+			rangesIndex++;
+		}
+
+		// Now that we have the starting range,
+		// lets find the last contiguous range
+		addr   += offset;
+		length -= offset;
+
+		for (++rangesIndex; rangesIndex < _rangesCount; rangesIndex++) {
+			mach_vm_address_t newAddr;
+			mach_vm_size_t    newLen;
+
+			getAddrLenForInd(newAddr, newLen, type, vec, rangesIndex);
+			if (addr + length != newAddr) {
+				break;
+			}
+			length += newLen;
+		}
+		if (addr) {
+			address = (IOPhysicalAddress) addr; // Truncate address to 32bit
+		}
+	} else {
+		IOMDDMAWalkSegmentState _state;
+		IOMDDMAWalkSegmentArgs * state = (IOMDDMAWalkSegmentArgs *) (void *)&_state;
+
+		state->fOffset = offset;
+		state->fLength = _length - offset;
+		state->fMapped = (0 == (options & kIOMemoryMapperNone)) && !(_flags & kIOMemoryHostOrRemote);
+
+		ret = dmaCommandOperation(kIOMDFirstSegment, _state, sizeof(_state));
+
+		if ((kIOReturnSuccess != ret) && (kIOReturnOverrun != ret)) {
+			DEBG("getPhysicalSegment dmaCommandOperation(%lx), %p, offset %qx, addr %qx, len %qx\n",
+			    ret, this, state->fOffset,
+			    state->fIOVMAddr, state->fLength);
+		}
+		if (kIOReturnSuccess == ret) {
+			address = state->fIOVMAddr;
+			length  = state->fLength;
+		}
+
+		// dmaCommandOperation() does not distinguish between "mapped" and "unmapped" physical memory, even
+		// with fMapped set correctly, so we must handle the transformation here until this gets cleaned up
+
+		if (mapper && ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type))) {
+			if ((options & kIOMemoryMapperNone) && !(_flags & kIOMemoryMapperNone)) {
+				addr64_t    origAddr = address;
+				IOByteCount origLen  = length;
+
+				address = mapper->mapToPhysicalAddress(origAddr);
+				length = page_size - (address & (page_size - 1));
+				while ((length < origLen)
+				    && ((address + length) == mapper->mapToPhysicalAddress(origAddr + length))) {
+					length += page_size;
+				}
+				if (length > origLen) {
+					length = origLen;
+				}
+			}
+		}
+	}
+
+	if (!address) {
+		length = 0;
+	}
+
+	if (lengthOfSegment) {
+		*lengthOfSegment = length;
+	}
+
+	return address;
+}
+
+#ifndef __LP64__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+
+addr64_t
+IOMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount *lengthOfSegment, IOOptionBits options)
+{
+	addr64_t address = 0;
+
+	if (options & _kIOMemorySourceSegment) {
+		address = getSourceSegment(offset, lengthOfSegment);
+	} else if (options & kIOMemoryMapperNone) {
+		address = getPhysicalSegment64(offset, lengthOfSegment);
+	} else {
+		address = getPhysicalSegment(offset, lengthOfSegment);
+	}
+
+	return address;
+}
+#pragma clang diagnostic pop
+
+addr64_t
+IOGeneralMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+	return getPhysicalSegment(offset, lengthOfSegment, kIOMemoryMapperNone);
+}
+
+IOPhysicalAddress
+IOGeneralMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+	addr64_t    address = 0;
+	IOByteCount length  = 0;
+
+	address = getPhysicalSegment(offset, lengthOfSegment, 0);
+
+	if (lengthOfSegment) {
+		length = *lengthOfSegment;
+	}
+
+	if ((address + length) > 0x100000000ULL) {
+		panic("getPhysicalSegment() out of 32b range 0x%qx, len 0x%lx, class %s",
+		    address, (long) length, (getMetaClass())->getClassName());
+	}
+
+	return (IOPhysicalAddress) address;
+}
+
+addr64_t
+IOMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+	IOPhysicalAddress phys32;
+	IOByteCount       length;
+	addr64_t          phys64;
+	IOMapper *        mapper = NULL;
+
+	phys32 = getPhysicalSegment(offset, lengthOfSegment);
+	if (!phys32) {
+		return 0;
+	}
+
+	if (gIOSystemMapper) {
+		mapper = gIOSystemMapper;
+	}
+
+	if (mapper) {
+		IOByteCount origLen;
+
+		phys64 = mapper->mapToPhysicalAddress(phys32);
+		origLen = *lengthOfSegment;
+		length = page_size - (phys64 & (page_size - 1));
+		while ((length < origLen)
+		    && ((phys64 + length) == mapper->mapToPhysicalAddress(phys32 + length))) {
+			length += page_size;
+		}
+		if (length > origLen) {
+			length = origLen;
+		}
+
+		*lengthOfSegment = length;
+	} else {
+		phys64 = (addr64_t) phys32;
+	}
+
+	return phys64;
+}
+
+IOPhysicalAddress
+IOMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+	return (IOPhysicalAddress) getPhysicalSegment(offset, lengthOfSegment, 0);
+}
+
+IOPhysicalAddress
+IOGeneralMemoryDescriptor::getSourceSegment(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+	return (IOPhysicalAddress) getPhysicalSegment(offset, lengthOfSegment, _kIOMemorySourceSegment);
+}
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+
+void *
+IOGeneralMemoryDescriptor::getVirtualSegment(IOByteCount offset,
+    IOByteCount * lengthOfSegment)
+{
+	if (_task == kernel_task) {
+		return (void *) getSourceSegment(offset, lengthOfSegment);
+	} else {
+		panic("IOGMD::getVirtualSegment deprecated");
+	}
+
+	return NULL;
+}
+#pragma clang diagnostic pop
+#endif /* !__LP64__ */
+
+IOReturn
+IOMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
+{
+	IOMemoryDescriptor *md = const_cast<IOMemoryDescriptor *>(this);
+	DMACommandOps params;
+	IOReturn err;
+
+	params = (op & ~kIOMDDMACommandOperationMask & op);
+	op &= kIOMDDMACommandOperationMask;
+
+	if (kIOMDGetCharacteristics == op) {
+		if (dataSize < sizeof(IOMDDMACharacteristics)) {
+			return kIOReturnUnderrun;
+		}
+
+		IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
+		data->fLength = getLength();
+		data->fSGCount = 0;
+		data->fDirection = getDirection();
+		data->fIsPrepared = true; // Assume prepared - fails safe
+	} else if (kIOMDWalkSegments == op) {
+		if (dataSize < sizeof(IOMDDMAWalkSegmentArgs)) {
+			return kIOReturnUnderrun;
+		}
+
+		IOMDDMAWalkSegmentArgs *data = (IOMDDMAWalkSegmentArgs *) vData;
+		IOByteCount offset  = (IOByteCount) data->fOffset;
+
+		IOPhysicalLength length;
+		if (data->fMapped && IOMapper::gSystem) {
+			data->fIOVMAddr = md->getPhysicalSegment(offset, &length);
+		} else {
+			data->fIOVMAddr = md->getPhysicalSegment(offset, &length, kIOMemoryMapperNone);
+		}
+		data->fLength = length;
+	} else if (kIOMDAddDMAMapSpec == op) {
+		return kIOReturnUnsupported;
+	} else if (kIOMDDMAMap == op) {
+		if (dataSize < sizeof(IOMDDMAMapArgs)) {
+			return kIOReturnUnderrun;
+		}
+		IOMDDMAMapArgs * data = (IOMDDMAMapArgs *) vData;
+
+		if (params) {
+			panic("class %s does not support IODMACommand::kIterateOnly", getMetaClass()->getClassName());
+		}
+
+		data->fMapContig = true;
+		err = md->dmaMap(data->fMapper, data->fCommand, &data->fMapSpec, data->fOffset, data->fLength, &data->fAlloc, &data->fAllocLength);
+
+		return err;
+	} else if (kIOMDDMAUnmap == op) {
+		if (dataSize < sizeof(IOMDDMAMapArgs)) {
+			return kIOReturnUnderrun;
+		}
+		IOMDDMAMapArgs * data = (IOMDDMAMapArgs *) vData;
+
+		err = md->dmaUnmap(data->fMapper, data->fCommand, data->fOffset, data->fAlloc, data->fAllocLength);
+
+		return kIOReturnSuccess;
+	} else {
+		return kIOReturnBadArgument;
+	}
+
+	return kIOReturnSuccess;
+}
+
+IOReturn
+IOGeneralMemoryDescriptor::setPurgeable( IOOptionBits newState,
+    IOOptionBits * oldState )
+{
+	IOReturn      err = kIOReturnSuccess;
+
+	vm_purgable_t control;
+	int           state;
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
+
+	if (_memRef) {
+		err = super::setPurgeable(newState, oldState);
+	} else {
+		if (kIOMemoryThreadSafe & _flags) {
+			LOCK;
+		}
+		do{
+			// Find the appropriate vm_map for the given task
+			vm_map_t curMap;
+			if (_task == kernel_task && (kIOMemoryBufferPageable & _flags)) {
+				err = kIOReturnNotReady;
+				break;
+			} else if (!_task) {
+				err = kIOReturnUnsupported;
+				break;
+			} else {
+				curMap = get_task_map(_task);
+				if (NULL == curMap) {
+					err = KERN_INVALID_ARGUMENT;
+					break;
+				}
+			}
+
+			// can only do one range
+			Ranges vec = _ranges;
+			IOOptionBits type = _flags & kIOMemoryTypeMask;
+			mach_vm_address_t addr;
+			mach_vm_size_t    len;
+			getAddrLenForInd(addr, len, type, vec, 0);
+
+			err = purgeableControlBits(newState, &control, &state);
+			if (kIOReturnSuccess != err) {
+				break;
+			}
+			err = vm_map_purgable_control(curMap, addr, control, &state);
+			if (oldState) {
+				if (kIOReturnSuccess == err) {
+					err = purgeableStateBits(&state);
+					*oldState = state;
+				}
+			}
+		}while (false);
+		if (kIOMemoryThreadSafe & _flags) {
+			UNLOCK;
+		}
+	}
+
+	return err;
+}
+
+IOReturn
+IOMemoryDescriptor::setPurgeable( IOOptionBits newState,
+    IOOptionBits * oldState )
+{
+	IOReturn err = kIOReturnNotReady;
+
+	if (kIOMemoryThreadSafe & _flags) {
+		LOCK;
+	}
+	if (_memRef) {
+		err = IOGeneralMemoryDescriptor::memoryReferenceSetPurgeable(_memRef, newState, oldState);
+	}
+	if (kIOMemoryThreadSafe & _flags) {
+		UNLOCK;
+	}
+
+	return err;
+}
+
+IOReturn
+IOGeneralMemoryDescriptor::setOwnership( task_t newOwner,
+    int newLedgerTag,
+    IOOptionBits newLedgerOptions )
+{
+	IOReturn      err = kIOReturnSuccess;
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
+
+	if (iokit_iomd_setownership_enabled == FALSE) {
+		return kIOReturnUnsupported;
+	}
+
+	if (_memRef) {
+		err = super::setOwnership(newOwner, newLedgerTag, newLedgerOptions);
+	} else {
+		err = kIOReturnUnsupported;
+	}
+
+	return err;
+}
+
+IOReturn
+IOMemoryDescriptor::setOwnership( task_t newOwner,
+    int newLedgerTag,
+    IOOptionBits newLedgerOptions )
+{
+	IOReturn err = kIOReturnNotReady;
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
+
+	if (iokit_iomd_setownership_enabled == FALSE) {
+		return kIOReturnUnsupported;
+	}
+
+	if (kIOMemoryThreadSafe & _flags) {
+		LOCK;
+	}
+	if (_memRef) {
+		err = IOGeneralMemoryDescriptor::memoryReferenceSetOwnership(_memRef, newOwner, newLedgerTag, newLedgerOptions);
+	} else {
+		IOMultiMemoryDescriptor * mmd;
+		IOSubMemoryDescriptor   * smd;
+		if ((smd = OSDynamicCast(IOSubMemoryDescriptor, this))) {
+			err = smd->setOwnership(newOwner, newLedgerTag, newLedgerOptions);
+		} else if ((mmd = OSDynamicCast(IOMultiMemoryDescriptor, this))) {
+			err = mmd->setOwnership(newOwner, newLedgerTag, newLedgerOptions);
+		}
+	}
+	if (kIOMemoryThreadSafe & _flags) {
+		UNLOCK;
+	}
+
+	return err;
+}
+
+IOReturn
+IOMemoryDescriptor::getPageCounts( IOByteCount * residentPageCount,
+    IOByteCount * dirtyPageCount )
+{
+	IOReturn err = kIOReturnNotReady;
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
+
+	if (kIOMemoryThreadSafe & _flags) {
+		LOCK;
+	}
+	if (_memRef) {
+		err = IOGeneralMemoryDescriptor::memoryReferenceGetPageCounts(_memRef, residentPageCount, dirtyPageCount);
+	} else {
+		IOMultiMemoryDescriptor * mmd;
+		IOSubMemoryDescriptor   * smd;
+		if ((smd = OSDynamicCast(IOSubMemoryDescriptor, this))) {
+			err = smd->getPageCounts(residentPageCount, dirtyPageCount);
+		} else if ((mmd = OSDynamicCast(IOMultiMemoryDescriptor, this))) {
+			err = mmd->getPageCounts(residentPageCount, dirtyPageCount);
+		}
+	}
+	if (kIOMemoryThreadSafe & _flags) {
+		UNLOCK;
+	}
+
+	return err;
+}
 
-        srcAddr64 = getPhysicalSegment64(offset, &srcLen);
-        if (!srcAddr64)
-            break;
 
-        // Clip segment length to remaining
-        if (srcLen > remaining)
-            srcLen = remaining;
+#if defined(__arm__) || defined(__arm64__)
+extern "C" void dcache_incoherent_io_flush64(addr64_t pa, unsigned int count, unsigned int remaining, unsigned int *res);
+extern "C" void dcache_incoherent_io_store64(addr64_t pa, unsigned int count, unsigned int remaining, unsigned int *res);
+#else /* defined(__arm__) || defined(__arm64__) */
+extern "C" void dcache_incoherent_io_flush64(addr64_t pa, unsigned int count);
+extern "C" void dcache_incoherent_io_store64(addr64_t pa, unsigned int count);
+#endif /* defined(__arm__) || defined(__arm64__) */
 
-        copypv(srcAddr64, dstAddr, srcLen,
-                            cppvPsrc | cppvNoRefSrc | cppvFsnk | cppvKmap);
+static void
+SetEncryptOp(addr64_t pa, unsigned int count)
+{
+	ppnum_t page, end;
 
-        dstAddr   += srcLen;
-        offset    += srcLen;
-        remaining -= srcLen;
-    }
+	page = atop_64(round_page_64(pa));
+	end  = atop_64(trunc_page_64(pa + count));
+	for (; page < end; page++) {
+		pmap_clear_noencrypt(page);
+	}
+}
 
-    assert(!remaining);
+static void
+ClearEncryptOp(addr64_t pa, unsigned int count)
+{
+	ppnum_t page, end;
 
-    return length - remaining;
+	page = atop_64(round_page_64(pa));
+	end  = atop_64(trunc_page_64(pa + count));
+	for (; page < end; page++) {
+		pmap_set_noencrypt(page);
+	}
 }
 
-IOByteCount IOMemoryDescriptor::writeBytes
-                (IOByteCount offset, const void *bytes, IOByteCount length)
-{
-    addr64_t srcAddr = (addr64_t) (UInt32) bytes;
-    IOByteCount remaining;
+IOReturn
+IOMemoryDescriptor::performOperation( IOOptionBits options,
+    IOByteCount offset, IOByteCount length )
+{
+	IOByteCount remaining;
+	unsigned int res;
+	void (*func)(addr64_t pa, unsigned int count) = NULL;
+#if defined(__arm__) || defined(__arm64__)
+	void (*func_ext)(addr64_t pa, unsigned int count, unsigned int remaining, unsigned int *result) = NULL;
+#endif
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
+
+	switch (options) {
+	case kIOMemoryIncoherentIOFlush:
+#if defined(__arm__) || defined(__arm64__)
+		func_ext = &dcache_incoherent_io_flush64;
+#if __ARM_COHERENT_IO__
+		func_ext(0, 0, 0, &res);
+		return kIOReturnSuccess;
+#else /* __ARM_COHERENT_IO__ */
+		break;
+#endif /* __ARM_COHERENT_IO__ */
+#else /* defined(__arm__) || defined(__arm64__) */
+		func = &dcache_incoherent_io_flush64;
+		break;
+#endif /* defined(__arm__) || defined(__arm64__) */
+	case kIOMemoryIncoherentIOStore:
+#if defined(__arm__) || defined(__arm64__)
+		func_ext = &dcache_incoherent_io_store64;
+#if __ARM_COHERENT_IO__
+		func_ext(0, 0, 0, &res);
+		return kIOReturnSuccess;
+#else /* __ARM_COHERENT_IO__ */
+		break;
+#endif /* __ARM_COHERENT_IO__ */
+#else /* defined(__arm__) || defined(__arm64__) */
+		func = &dcache_incoherent_io_store64;
+		break;
+#endif /* defined(__arm__) || defined(__arm64__) */
+
+	case kIOMemorySetEncrypted:
+		func = &SetEncryptOp;
+		break;
+	case kIOMemoryClearEncrypted:
+		func = &ClearEncryptOp;
+		break;
+	}
+
+#if defined(__arm__) || defined(__arm64__)
+	if ((func == NULL) && (func_ext == NULL)) {
+		return kIOReturnUnsupported;
+	}
+#else /* defined(__arm__) || defined(__arm64__) */
+	if (!func) {
+		return kIOReturnUnsupported;
+	}
+#endif /* defined(__arm__) || defined(__arm64__) */
+
+	if (kIOMemoryThreadSafe & _flags) {
+		LOCK;
+	}
+
+	res = 0x0UL;
+	remaining = length = min(length, getLength() - offset);
+	while (remaining) {
+		// (process another target segment?)
+		addr64_t    dstAddr64;
+		IOByteCount dstLen;
+
+		dstAddr64 = getPhysicalSegment(offset, &dstLen, kIOMemoryMapperNone);
+		if (!dstAddr64) {
+			break;
+		}
+
+		// Clip segment length to remaining
+		if (dstLen > remaining) {
+			dstLen = remaining;
+		}
 
-    // Assert that this entire I/O is withing the available range
-    assert(offset < _length);
-    assert(offset + length <= _length);
+#if defined(__arm__) || defined(__arm64__)
+		if (func) {
+			(*func)(dstAddr64, dstLen);
+		}
+		if (func_ext) {
+			(*func_ext)(dstAddr64, dstLen, remaining, &res);
+			if (res != 0x0UL) {
+				remaining = 0;
+				break;
+			}
+		}
+#else /* defined(__arm__) || defined(__arm64__) */
+		(*func)(dstAddr64, dstLen);
+#endif /* defined(__arm__) || defined(__arm64__) */
 
-    assert( !(kIOMemoryPreparedReadOnly & _flags) );
+		offset    += dstLen;
+		remaining -= dstLen;
+	}
 
-    if ( (kIOMemoryPreparedReadOnly & _flags) || offset >= _length) {
-IOLog("IOGMD(%p): wB = o%lx, l%lx\n", this, offset, length);	// @@@ gvdl
-        return 0;
-    }
+	if (kIOMemoryThreadSafe & _flags) {
+		UNLOCK;
+	}
 
-    remaining = length = min(length, _length - offset);
-    while (remaining) {	// (process another target segment?)
-        addr64_t    dstAddr64;
-        IOByteCount dstLen;
+	return remaining ? kIOReturnUnderrun : kIOReturnSuccess;
+}
 
-        dstAddr64 = getPhysicalSegment64(offset, &dstLen);
-        if (!dstAddr64)
-            break;
+/*
+ *
+ */
 
-        // Clip segment length to remaining
-        if (dstLen > remaining)
-            dstLen = remaining;
+#if defined(__i386__) || defined(__x86_64__)
 
-        copypv(srcAddr, (addr64_t) dstAddr64, dstLen,
-                            cppvPsnk | cppvFsnk | cppvNoRefSrc | cppvNoModSnk | cppvKmap);
+#define io_kernel_static_start  vm_kernel_stext
+#define io_kernel_static_end    vm_kernel_etext
 
-        srcAddr   += dstLen;
-        offset    += dstLen;
-        remaining -= dstLen;
-    }
+#elif defined(__arm__) || defined(__arm64__)
 
-    assert(!remaining);
+extern vm_offset_t              static_memory_end;
 
-    return length - remaining;
-}
+#if defined(__arm64__)
+#define io_kernel_static_start vm_kext_base
+#else /* defined(__arm64__) */
+#define io_kernel_static_start vm_kernel_stext
+#endif /* defined(__arm64__) */
 
-// osfmk/device/iokit_rpc.c
-extern "C" unsigned int IODefaultCacheBits(addr64_t pa);
+#define io_kernel_static_end    static_memory_end
 
-/* DEPRECATED */ void IOGeneralMemoryDescriptor::setPosition(IOByteCount position)
-/* DEPRECATED */ {
-                    panic("IOGMD::setPosition deprecated");
-/* DEPRECATED */ }
+#else
+#error io_kernel_static_end is undefined for this architecture
+#endif
 
-IOReturn IOGeneralMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
+static kern_return_t
+io_get_kernel_static_upl(
+	vm_map_t                /* map */,
+	uintptr_t               offset,
+	upl_size_t              *upl_size,
+	upl_t                   *upl,
+	upl_page_info_array_t   page_list,
+	unsigned int            *count,
+	ppnum_t                 *highest_page)
 {
-    if (kIOMDGetCharacteristics == op) {
+	unsigned int pageCount, page;
+	ppnum_t phys;
+	ppnum_t highestPage = 0;
 
-	if (dataSize < sizeof(IOMDDMACharacteristics))
-	    return kIOReturnUnderrun;
-
-	IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
-	data->fLength = _length;
-	data->fSGCount = _rangesCount;
-	data->fPages = _pages;
-	data->fDirection = _direction;
-	if (!_wireCount)
-	    data->fIsPrepared = false;
-	else {
-	    data->fIsPrepared = true;
-	    data->fHighestPage = _highestPage;
-	    if (_memoryEntries) {
-		ioGMDData *gmdData = getDataP(_memoryEntries);
-		ioPLBlock *ioplList = getIOPLList(gmdData);
-		UInt count = getNumIOPL(_memoryEntries, gmdData);
-
-		data->fIsMapped = (gmdData->fMapper && _pages && (count > 0)
-			       && ioplList[0].fMappedBase);
-		if (count == 1)
-		    data->fPageAlign = (ioplList[0].fPageOffset & PAGE_MASK) | ~PAGE_MASK;
-	    }
-	    else
-		data->fIsMapped = false;
+	pageCount = atop_32(*upl_size);
+	if (pageCount > *count) {
+		pageCount = *count;
 	}
 
-	return kIOReturnSuccess;
-    }
-    else if (!(kIOMDWalkSegments & op))
-	return kIOReturnBadArgument;
-
-    // Get the next segment
-    struct InternalState {
-	IOMDDMAWalkSegmentArgs fIO;
-	UInt fOffset2Index;
-	UInt fIndex;
-	UInt fNextOffset;
-    } *isP;
-
-    // Find the next segment
-    if (dataSize < sizeof(*isP))
-	return kIOReturnUnderrun;
-
-    isP = (InternalState *) vData;
-    UInt offset = isP->fIO.fOffset;
-    bool mapped = isP->fIO.fMapped;
-
-    if (offset >= _length)
-	return (offset == _length)? kIOReturnOverrun : kIOReturnInternalError;
-
-    // Validate the previous offset
-    UInt ind, off2Ind = isP->fOffset2Index;
-    if ((kIOMDFirstSegment != op) 
-	&& offset 
-	&& (offset == isP->fNextOffset || off2Ind <= offset))
-	ind = isP->fIndex;
-    else
-	ind = off2Ind = 0;	// Start from beginning
-
-    UInt length;
-    UInt64 address;
-    if ( (_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical) {
-
-	// Physical address based memory descriptor
-	const IOPhysicalRange *physP = (IOPhysicalRange *) &_ranges.p[0];
-
-	// Find the range after the one that contains the offset
-	UInt len;
-	for (len = 0; off2Ind <= offset; ind++) {
-	    len = physP[ind].length;
-	    off2Ind += len;
-	}
-
-	// Calculate length within range and starting address
-	length   = off2Ind - offset;
-	address  = physP[ind - 1].address + len - length;
-
-	// see how far we can coalesce ranges
-	while (ind < _rangesCount && address + length == physP[ind].address) {
-	    len = physP[ind].length;
-	    length += len;
-	    off2Ind += len;
-	    ind++;
-	}
-
-	// correct contiguous check overshoot
-	ind--;
-	off2Ind -= len;
-    }
-    else if ( (_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64) {
-
-	// Physical address based memory descriptor
-	const IOAddressRange *physP = (IOAddressRange *) &_ranges.v64[0];
-
-	// Find the range after the one that contains the offset
-	mach_vm_size_t len;
-	for (len = 0; off2Ind <= offset; ind++) {
-	    len = physP[ind].length;
-	    off2Ind += len;
-	}
-
-	// Calculate length within range and starting address
-	length   = off2Ind - offset;
-	address  = physP[ind - 1].address + len - length;
-
-	// see how far we can coalesce ranges
-	while (ind < _rangesCount && address + length == physP[ind].address) {
-	    len = physP[ind].length;
-	    length += len;
-	    off2Ind += len;
-	    ind++;
-	}
-
-	// correct contiguous check overshoot
-	ind--;
-	off2Ind -= len;
-    }
-    else do {
-	if (!_wireCount)
-	    panic("IOGMD: not wired for the IODMACommand");
-
-	assert(_memoryEntries);
-
-	ioGMDData * dataP = getDataP(_memoryEntries);
-	const ioPLBlock *ioplList = getIOPLList(dataP);
-	UInt numIOPLs = getNumIOPL(_memoryEntries, dataP);
-	upl_page_info_t *pageList = getPageList(dataP);
-
-	assert(numIOPLs > 0);
-
-	// Scan through iopl info blocks looking for block containing offset
-	while (ind < numIOPLs && offset >= ioplList[ind].fIOMDOffset)
-	    ind++;
-
-	// Go back to actual range as search goes past it
-	ioPLBlock ioplInfo = ioplList[ind - 1];
-	off2Ind = ioplInfo.fIOMDOffset;
-
-	if (ind < numIOPLs)
-	    length = ioplList[ind].fIOMDOffset;
-	else
-	    length = _length;
-	length -= offset;			// Remainder within iopl
-
-	// Subtract offset till this iopl in total list
-	offset -= off2Ind;
-
-	// If a mapped address is requested and this is a pre-mapped IOPL
-	// then just need to compute an offset relative to the mapped base.
-	if (mapped && ioplInfo.fMappedBase) {
-	    offset += (ioplInfo.fPageOffset & PAGE_MASK);
-	    address = ptoa_64(ioplInfo.fMappedBase) + offset;
-	    continue;	// Done leave do/while(false) now
-	}
-
-	// The offset is rebased into the current iopl.
-	// Now add the iopl 1st page offset.
-	offset += ioplInfo.fPageOffset;
-
-	// For external UPLs the fPageInfo field points directly to
-	// the upl's upl_page_info_t array.
-	if (ioplInfo.fFlags & kIOPLExternUPL)
-	    pageList = (upl_page_info_t *) ioplInfo.fPageInfo;
-	else
-	    pageList = &pageList[ioplInfo.fPageInfo];
-
-	// Check for direct device non-paged memory
-	if ( ioplInfo.fFlags & kIOPLOnDevice ) {
-	    address = ptoa_64(pageList->phys_addr) + offset;
-	    continue;	// Done leave do/while(false) now
-	}
+	*upl = NULL;
 
-	// Now we need compute the index into the pageList
-	UInt pageInd = atop_32(offset);
-	offset &= PAGE_MASK;
-
-	// Compute the starting address of this segment
-	IOPhysicalAddress pageAddr = pageList[pageInd].phys_addr;
-	address = ptoa_64(pageAddr) + offset;
-
-	// length is currently set to the length of the remainider of the iopl.
-	// We need to check that the remainder of the iopl is contiguous.
-	// This is indicated by pageList[ind].phys_addr being sequential.
-	IOByteCount contigLength = PAGE_SIZE - offset;
-	while (contigLength < length
-		&& ++pageAddr == pageList[++pageInd].phys_addr)
-	{
-	    contigLength += PAGE_SIZE;
+	for (page = 0; page < pageCount; page++) {
+		phys = pmap_find_phys(kernel_pmap, ((addr64_t)offset) + ptoa_64(page));
+		if (!phys) {
+			break;
+		}
+		page_list[page].phys_addr = phys;
+		page_list[page].free_when_done = 0;
+		page_list[page].absent    = 0;
+		page_list[page].dirty     = 0;
+		page_list[page].precious  = 0;
+		page_list[page].device    = 0;
+		if (phys > highestPage) {
+			highestPage = phys;
+		}
 	}
 
-	if (contigLength < length)
-	    length = contigLength;
-	
-
-	assert(address);
-	assert(length);
+	*highest_page = highestPage;
 
-    } while (false);
-
-    // Update return values and state
-    isP->fIO.fIOVMAddr = address;
-    isP->fIO.fLength   = length;
-    isP->fIndex        = ind;
-    isP->fOffset2Index = off2Ind;
-    isP->fNextOffset   = isP->fIO.fOffset + length;
-
-    return kIOReturnSuccess;
+	return (page >= pageCount) ? kIOReturnSuccess : kIOReturnVMError;
 }
 
-addr64_t
-IOGeneralMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount *lengthOfSegment)
+IOReturn
+IOGeneralMemoryDescriptor::wireVirtual(IODirection forDirection)
 {
-    IOReturn    ret;
-    IOByteCount length  = 0;
-    addr64_t    address = 0;
-
-    if (offset < _length) // (within bounds?)
-    {
-	IOMDDMAWalkSegmentState _state;
-	IOMDDMAWalkSegmentArgs * state = (IOMDDMAWalkSegmentArgs *) &_state;
-
-	state->fOffset = offset;
-	state->fLength = _length - offset;
-	state->fMapped = false;
+	IOOptionBits type = _flags & kIOMemoryTypeMask;
+	IOReturn error = kIOReturnSuccess;
+	ioGMDData *dataP;
+	upl_page_info_array_t pageInfo;
+	ppnum_t mapBase;
+	vm_tag_t tag = VM_KERN_MEMORY_NONE;
 
-	ret = dmaCommandOperation(kIOMDFirstSegment, _state, sizeof(_state));
+	assert(kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type);
 
-	if ((kIOReturnSuccess != ret) && (kIOReturnOverrun != ret))
-		DEBG("getPhysicalSegment64 dmaCommandOperation(%lx), %p, offset %qx, addr %qx, len %qx\n", 
-					ret, this, state->fOffset,
-					state->fIOVMAddr, state->fLength);
-	if (kIOReturnSuccess == ret)
-	{
-	    address = state->fIOVMAddr;
-	    length  = state->fLength;
+	if ((kIODirectionOutIn & forDirection) == kIODirectionNone) {
+		forDirection = (IODirection) (forDirection | getDirection());
 	}
-        if (!address)
-            length = 0;
-    }
 
-    if (lengthOfSegment)
-        *lengthOfSegment = length;
+	dataP = getDataP(_memoryEntries);
+	upl_control_flags_t uplFlags; // This Mem Desc's default flags for upl creation
+	switch (kIODirectionOutIn & forDirection) {
+	case kIODirectionOut:
+		// Pages do not need to be marked as dirty on commit
+		uplFlags = UPL_COPYOUT_FROM;
+		dataP->fDMAAccess = kIODMAMapReadAccess;
+		break;
 
-    return (address);
-}
+	case kIODirectionIn:
+		dataP->fDMAAccess = kIODMAMapWriteAccess;
+		uplFlags = 0;   // i.e. ~UPL_COPYOUT_FROM
+		break;
 
-IOPhysicalAddress
-IOGeneralMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount *lengthOfSegment)
-{
-    IOReturn          ret;
-    IOByteCount       length  = 0;
-    addr64_t	      address = 0;
+	default:
+		dataP->fDMAAccess = kIODMAMapReadAccess | kIODMAMapWriteAccess;
+		uplFlags = 0;   // i.e. ~UPL_COPYOUT_FROM
+		break;
+	}
 
-//  assert(offset <= _length);
+	if (_wireCount) {
+		if ((kIOMemoryPreparedReadOnly & _flags) && !(UPL_COPYOUT_FROM & uplFlags)) {
+			OSReportWithBacktrace("IOMemoryDescriptor 0x%lx prepared read only", VM_KERNEL_ADDRPERM(this));
+			error = kIOReturnNotWritable;
+		}
+	} else {
+		IOMapper *mapper;
 
-    if (offset < _length) // (within bounds?)
-    {
-	IOMDDMAWalkSegmentState _state;
-	IOMDDMAWalkSegmentArgs * state = (IOMDDMAWalkSegmentArgs *) &_state;
+		mapper = dataP->fMapper;
+		dataP->fMappedBaseValid = dataP->fMappedBase = 0;
 
-	state->fOffset = offset;
-	state->fLength = _length - offset;
-	state->fMapped = true;
+		uplFlags |= UPL_SET_IO_WIRE | UPL_SET_LITE;
+		tag = _kernelTag;
+		if (VM_KERN_MEMORY_NONE == tag) {
+			tag = IOMemoryTag(kernel_map);
+		}
 
-	ret = dmaCommandOperation(
-		kIOMDFirstSegment, _state, sizeof(_state));
+		if (kIODirectionPrepareToPhys32 & forDirection) {
+			if (!mapper) {
+				uplFlags |= UPL_NEED_32BIT_ADDR;
+			}
+			if (dataP->fDMAMapNumAddressBits > 32) {
+				dataP->fDMAMapNumAddressBits = 32;
+			}
+		}
+		if (kIODirectionPrepareNoFault    & forDirection) {
+			uplFlags |= UPL_REQUEST_NO_FAULT;
+		}
+		if (kIODirectionPrepareNoZeroFill & forDirection) {
+			uplFlags |= UPL_NOZEROFILLIO;
+		}
+		if (kIODirectionPrepareNonCoherent & forDirection) {
+			uplFlags |= UPL_REQUEST_FORCE_COHERENCY;
+		}
 
-	if ((kIOReturnSuccess != ret) && (kIOReturnOverrun != ret))
-	    DEBG("getPhysicalSegment dmaCommandOperation(%lx), %p, offset %qx, addr %qx, len %qx\n", 
-				    ret, this, state->fOffset,
-				    state->fIOVMAddr, state->fLength);
-	if (kIOReturnSuccess == ret)
-	{
-	    address = state->fIOVMAddr;
-	    length  = state->fLength;
-	}
+		mapBase = 0;
 
-        if (!address)
-            length = 0;
-    }
+		// Note that appendBytes(NULL) zeros the data up to the desired length
+		//           and the length parameter is an unsigned int
+		size_t uplPageSize = dataP->fPageCnt * sizeof(upl_page_info_t);
+		if (uplPageSize > ((unsigned int)uplPageSize)) {
+			return kIOReturnNoMemory;
+		}
+		if (!_memoryEntries->appendBytes(NULL, uplPageSize)) {
+			return kIOReturnNoMemory;
+		}
+		dataP = NULL;
+
+		// Find the appropriate vm_map for the given task
+		vm_map_t curMap;
+		if ((NULL != _memRef) || ((_task == kernel_task && (kIOMemoryBufferPageable & _flags)))) {
+			curMap = NULL;
+		} else {
+			curMap = get_task_map(_task);
+		}
 
-    if ((address + length) > 0x100000000ULL)
-    {
-	panic("getPhysicalSegment() out of 32b range 0x%qx, len 0x%x, class %s",
-		    address, length, (getMetaClass())->getClassName());
-    }
+		// Iterate over the vector of virtual ranges
+		Ranges vec = _ranges;
+		unsigned int pageIndex  = 0;
+		IOByteCount mdOffset    = 0;
+		ppnum_t highestPage     = 0;
 
-    if (lengthOfSegment)
-        *lengthOfSegment = length;
+		IOMemoryEntry * memRefEntry = NULL;
+		if (_memRef) {
+			memRefEntry = &_memRef->entries[0];
+		}
 
-    return ((IOPhysicalAddress) address);
-}
+		for (UInt range = 0; range < _rangesCount; range++) {
+			ioPLBlock iopl;
+			mach_vm_address_t startPage, startPageOffset;
+			mach_vm_size_t    numBytes;
+			ppnum_t highPage = 0;
+
+			// Get the startPage address and length of vec[range]
+			getAddrLenForInd(startPage, numBytes, type, vec, range);
+			startPageOffset = startPage & PAGE_MASK;
+			iopl.fPageOffset = startPageOffset;
+			numBytes += startPageOffset;
+			startPage = trunc_page_64(startPage);
+
+			if (mapper) {
+				iopl.fMappedPage = mapBase + pageIndex;
+			} else {
+				iopl.fMappedPage = 0;
+			}
+
+			// Iterate over the current range, creating UPLs
+			while (numBytes) {
+				vm_address_t kernelStart = (vm_address_t) startPage;
+				vm_map_t theMap;
+				if (curMap) {
+					theMap = curMap;
+				} else if (_memRef) {
+					theMap = NULL;
+				} else {
+					assert(_task == kernel_task);
+					theMap = IOPageableMapForAddress(kernelStart);
+				}
+
+				// ioplFlags is an in/out parameter
+				upl_control_flags_t ioplFlags = uplFlags;
+				dataP = getDataP(_memoryEntries);
+				pageInfo = getPageList(dataP);
+				upl_page_list_ptr_t baseInfo = &pageInfo[pageIndex];
+
+				mach_vm_size_t _ioplSize    = round_page(numBytes);
+				upl_size_t          ioplSize    = (_ioplSize <= MAX_UPL_SIZE_BYTES) ? _ioplSize : MAX_UPL_SIZE_BYTES;
+				unsigned int    numPageInfo = atop_32(ioplSize);
+
+				if ((theMap == kernel_map)
+				    && (kernelStart >= io_kernel_static_start)
+				    && (kernelStart < io_kernel_static_end)) {
+					error = io_get_kernel_static_upl(theMap,
+					    kernelStart,
+					    &ioplSize,
+					    &iopl.fIOPL,
+					    baseInfo,
+					    &numPageInfo,
+					    &highPage);
+				} else if (_memRef) {
+					memory_object_offset_t entryOffset;
+
+					entryOffset = mdOffset;
+					entryOffset = (entryOffset - iopl.fPageOffset - memRefEntry->offset);
+					if (entryOffset >= memRefEntry->size) {
+						memRefEntry++;
+						if (memRefEntry >= &_memRef->entries[_memRef->count]) {
+							panic("memRefEntry");
+						}
+						entryOffset = 0;
+					}
+					if (ioplSize > (memRefEntry->size - entryOffset)) {
+						ioplSize = (memRefEntry->size - entryOffset);
+					}
+					error = memory_object_iopl_request(memRefEntry->entry,
+					    entryOffset,
+					    &ioplSize,
+					    &iopl.fIOPL,
+					    baseInfo,
+					    &numPageInfo,
+					    &ioplFlags,
+					    tag);
+				} else {
+					assert(theMap);
+					error = vm_map_create_upl(theMap,
+					    startPage,
+					    (upl_size_t*)&ioplSize,
+					    &iopl.fIOPL,
+					    baseInfo,
+					    &numPageInfo,
+					    &ioplFlags,
+					    tag);
+				}
+
+				if (error != KERN_SUCCESS) {
+					goto abortExit;
+				}
+
+				assert(ioplSize);
+
+				if (iopl.fIOPL) {
+					highPage = upl_get_highest_page(iopl.fIOPL);
+				}
+				if (highPage > highestPage) {
+					highestPage = highPage;
+				}
+
+				if (baseInfo->device) {
+					numPageInfo = 1;
+					iopl.fFlags = kIOPLOnDevice;
+				} else {
+					iopl.fFlags = 0;
+				}
+
+				iopl.fIOMDOffset = mdOffset;
+				iopl.fPageInfo = pageIndex;
+				if (mapper && pageIndex && (page_mask & (mdOffset + startPageOffset))) {
+					dataP->fDiscontig = true;
+				}
+
+				if (!_memoryEntries->appendBytes(&iopl, sizeof(iopl))) {
+					// Clean up partial created and unsaved iopl
+					if (iopl.fIOPL) {
+						upl_abort(iopl.fIOPL, 0);
+						upl_deallocate(iopl.fIOPL);
+					}
+					goto abortExit;
+				}
+				dataP = NULL;
+
+				// Check for a multiple iopl's in one virtual range
+				pageIndex += numPageInfo;
+				mdOffset -= iopl.fPageOffset;
+				if (ioplSize < numBytes) {
+					numBytes -= ioplSize;
+					startPage += ioplSize;
+					mdOffset += ioplSize;
+					iopl.fPageOffset = 0;
+					if (mapper) {
+						iopl.fMappedPage = mapBase + pageIndex;
+					}
+				} else {
+					mdOffset += numBytes;
+					break;
+				}
+			}
+		}
 
-addr64_t
-IOMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount *lengthOfSegment)
-{
-    IOPhysicalAddress phys32;
-    IOByteCount	      length;
-    addr64_t 	      phys64;
-    IOMapper *        mapper = 0;
+		_highestPage = highestPage;
 
-    phys32 = getPhysicalSegment(offset, lengthOfSegment);
-    if (!phys32)
-	return 0;
+		if (UPL_COPYOUT_FROM & uplFlags) {
+			_flags |= kIOMemoryPreparedReadOnly;
+		}
+	}
 
-    if (gIOSystemMapper)
-	mapper = gIOSystemMapper;
+#if IOTRACKING
+	if (!(_flags & kIOMemoryAutoPrepare) && (kIOReturnSuccess == error)) {
+		dataP = getDataP(_memoryEntries);
+		if (!dataP->fWireTracking.link.next) {
+			IOTrackingAdd(gIOWireTracking, &dataP->fWireTracking, ptoa(_pages), false, tag);
+		}
+	}
+#endif /* IOTRACKING */
 
-    if (mapper)
-    {
-	IOByteCount origLen;
+	return error;
 
-	phys64 = mapper->mapAddr(phys32);
-	origLen = *lengthOfSegment;
-	length = page_size - (phys64 & (page_size - 1));
-	while ((length < origLen)
-	    && ((phys64 + length) == mapper->mapAddr(phys32 + length)))
-	    length += page_size;
-	if (length > origLen)
-	    length = origLen;
+abortExit:
+	{
+		dataP = getDataP(_memoryEntries);
+		UInt done = getNumIOPL(_memoryEntries, dataP);
+		ioPLBlock *ioplList = getIOPLList(dataP);
+
+		for (UInt range = 0; range < done; range++) {
+			if (ioplList[range].fIOPL) {
+				upl_abort(ioplList[range].fIOPL, 0);
+				upl_deallocate(ioplList[range].fIOPL);
+			}
+		}
+		(void) _memoryEntries->initWithBytes(dataP, computeDataSize(0, 0)); // == setLength()
+	}
 
-	*lengthOfSegment = length;
-    }
-    else
-	phys64 = (addr64_t) phys32;
+	if (error == KERN_FAILURE) {
+		error = kIOReturnCannotWire;
+	} else if (error == KERN_MEMORY_ERROR) {
+		error = kIOReturnNoResources;
+	}
 
-    return phys64;
+	return error;
 }
 
-IOPhysicalAddress
-IOGeneralMemoryDescriptor::getSourceSegment(IOByteCount offset, IOByteCount *lengthOfSegment)
+bool
+IOGeneralMemoryDescriptor::initMemoryEntries(size_t size, IOMapper * mapper)
 {
-    IOPhysicalAddress address = 0;
-    IOPhysicalLength  length  = 0;
-    IOOptionBits      type    = _flags & kIOMemoryTypeMask;
+	ioGMDData * dataP;
+	unsigned    dataSize = size;
 
-    assert(offset <= _length);
+	if (!_memoryEntries) {
+		_memoryEntries = OSData::withCapacity(dataSize);
+		if (!_memoryEntries) {
+			return false;
+		}
+	} else if (!_memoryEntries->initWithCapacity(dataSize)) {
+		return false;
+	}
 
-    if ( type == kIOMemoryTypeUPL)
-	return super::getSourceSegment( offset, lengthOfSegment );
-    else if ( offset < _length ) // (within bounds?)
-    {
-        unsigned rangesIndex = 0;
-	Ranges vec = _ranges;
-	user_addr_t addr;
+	_memoryEntries->appendBytes(NULL, computeDataSize(0, 0));
+	dataP = getDataP(_memoryEntries);
 
-	// Find starting address within the vector of ranges
-	for (;;) {
-	    getAddrLenForInd(addr, length, type, vec, rangesIndex);
-	    if (offset < length)
-		break;
-	    offset -= length; // (make offset relative)
-	    rangesIndex++;
-	} 
+	if (mapper == kIOMapperWaitSystem) {
+		IOMapper::checkForSystemMapper();
+		mapper = IOMapper::gSystem;
+	}
+	dataP->fMapper               = mapper;
+	dataP->fPageCnt              = 0;
+	dataP->fMappedBase           = 0;
+	dataP->fDMAMapNumAddressBits = 64;
+	dataP->fDMAMapAlignment      = 0;
+	dataP->fPreparationID        = kIOPreparationIDUnprepared;
+	dataP->fDiscontig            = false;
+	dataP->fCompletionError      = false;
+	dataP->fMappedBaseValid      = false;
+
+	return true;
+}
 
-	// Now that we have the starting range,
-	// lets find the last contiguous range
-        addr   += offset;
-        length -= offset;
+IOReturn
+IOMemoryDescriptor::dmaMap(
+	IOMapper                    * mapper,
+	IODMACommand                * command,
+	const IODMAMapSpecification * mapSpec,
+	uint64_t                      offset,
+	uint64_t                      length,
+	uint64_t                    * mapAddress,
+	uint64_t                    * mapLength)
+{
+	IOReturn err;
+	uint32_t mapOptions;
 
-        for ( ++rangesIndex; rangesIndex < _rangesCount; rangesIndex++ ) {
-	    user_addr_t      newAddr;
-	    IOPhysicalLength newLen;
+	mapOptions = 0;
+	mapOptions |= kIODMAMapReadAccess;
+	if (!(kIOMemoryPreparedReadOnly & _flags)) {
+		mapOptions |= kIODMAMapWriteAccess;
+	}
 
-	    getAddrLenForInd(newAddr, newLen, type, vec, rangesIndex);
-	    if (addr + length != newAddr)
-		break;
-	    length += newLen;
-	} 
-        if (addr)
-	    address = (IOPhysicalAddress) addr;	// Truncate address to 32bit
-	else
-	    length = 0;
-    }
+	err = mapper->iovmMapMemory(this, offset, length, mapOptions,
+	    mapSpec, command, NULL, mapAddress, mapLength);
 
-    if ( lengthOfSegment )  *lengthOfSegment = length;
+	if (kIOReturnSuccess == err) {
+		dmaMapRecord(mapper, command, *mapLength);
+	}
 
-    return address;
+	return err;
 }
 
-/* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
-/* DEPRECATED */ void * IOGeneralMemoryDescriptor::getVirtualSegment(IOByteCount offset,
-/* DEPRECATED */ 							IOByteCount * lengthOfSegment)
-/* DEPRECATED */ {
-                    if (_task == kernel_task)
-                        return (void *) getSourceSegment(offset, lengthOfSegment);
-                    else
-                        panic("IOGMD::getVirtualSegment deprecated");
-
-                    return 0;
-/* DEPRECATED */ }
-/* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
-
+void
+IOMemoryDescriptor::dmaMapRecord(
+	IOMapper                    * mapper,
+	IODMACommand                * command,
+	uint64_t                      mapLength)
+{
+	kern_allocation_name_t alloc;
+	int16_t                prior;
 
+	if ((alloc = mapper->fAllocName) /* && mapper != IOMapper::gSystem */) {
+		kern_allocation_update_size(mapper->fAllocName, mapLength);
+	}
 
-IOReturn 
-IOMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
-{
-    if (kIOMDGetCharacteristics == op) {
-	if (dataSize < sizeof(IOMDDMACharacteristics))
-	    return kIOReturnUnderrun;
-
-	IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
-	data->fLength = getLength();
-	data->fSGCount = 0;
-	data->fDirection = _direction;
-	if (IOMapper::gSystem)
-	    data->fIsMapped = true;
-	data->fIsPrepared = true;	// Assume prepared - fails safe
-    }
-    else if (kIOMDWalkSegments & op) {
-	if (dataSize < sizeof(IOMDDMAWalkSegmentArgs))
-	    return kIOReturnUnderrun;
-
-	IOMDDMAWalkSegmentArgs *data = (IOMDDMAWalkSegmentArgs *) vData;
-	IOByteCount offset  = (IOByteCount) data->fOffset;
-
-	IOPhysicalLength length;
-	IOMemoryDescriptor *ncmd = const_cast<IOMemoryDescriptor *>(this);
-	if (data->fMapped && IOMapper::gSystem)
-	    data->fIOVMAddr = ncmd->getPhysicalSegment(offset, &length);
-	else
-	    data->fIOVMAddr = ncmd->getPhysicalSegment64(offset, &length);
-	data->fLength = length;
-    }
-    else
-	return kIOReturnBadArgument;
-
-    return kIOReturnSuccess;
-}
-
-IOReturn IOMemoryDescriptor::setPurgeable( IOOptionBits newState,
-                                           IOOptionBits * oldState )
-{
-    IOReturn	  err = kIOReturnSuccess;
-    vm_purgable_t control;
-    int           state;
-
-    do 
-    {
-        if (!_memEntry)
-        {
-            err = kIOReturnNotReady;
-            break;
-        }
-
-        control = VM_PURGABLE_SET_STATE;
-        switch (newState)
-        {
-            case kIOMemoryPurgeableKeepCurrent:
-                control = VM_PURGABLE_GET_STATE;
-                break;
-
-            case kIOMemoryPurgeableNonVolatile:
-                state = VM_PURGABLE_NONVOLATILE;
-                break;
-            case kIOMemoryPurgeableVolatile:
-                state = VM_PURGABLE_VOLATILE;
-                break;
-            case kIOMemoryPurgeableEmpty:
-                state = VM_PURGABLE_EMPTY;
-                break;
-            default:
-                err = kIOReturnBadArgument;
-                break;
-        }
-
-        if (kIOReturnSuccess != err)
-            break;
-
-        err = mach_memory_entry_purgable_control((ipc_port_t) _memEntry, control, &state);
-
-        if (oldState)
-        {
-            if (kIOReturnSuccess == err)
-            {
-                switch (state)
-                {
-                    case VM_PURGABLE_NONVOLATILE:
-                        state = kIOMemoryPurgeableNonVolatile;
-                        break;
-                    case VM_PURGABLE_VOLATILE:
-                        state = kIOMemoryPurgeableVolatile;
-                        break;
-                    case VM_PURGABLE_EMPTY:
-                        state = kIOMemoryPurgeableEmpty;
-                        break;
-                    default:
-                        state = kIOMemoryPurgeableNonVolatile;
-                        err = kIOReturnNotReady;
-                        break;
-                }
-                *oldState = state;
-            }
-        }
-    }
-    while (false);
-
-    return (err);
+	if (!command) {
+		return;
+	}
+	prior = OSAddAtomic16(1, &_dmaReferences);
+	if (!prior) {
+		if (alloc && (VM_KERN_MEMORY_NONE != _kernelTag)) {
+			_mapName  = alloc;
+			mapLength = _length;
+			kern_allocation_update_subtotal(alloc, _kernelTag, mapLength);
+		} else {
+			_mapName = NULL;
+		}
+	}
 }
 
-extern "C" void dcache_incoherent_io_flush64(addr64_t pa, unsigned int count);
-extern "C" void dcache_incoherent_io_store64(addr64_t pa, unsigned int count);
-
-IOReturn IOMemoryDescriptor::performOperation( IOOptionBits options,
-                                                IOByteCount offset, IOByteCount length )
+IOReturn
+IOMemoryDescriptor::dmaUnmap(
+	IOMapper                    * mapper,
+	IODMACommand                * command,
+	uint64_t                      offset,
+	uint64_t                      mapAddress,
+	uint64_t                      mapLength)
 {
-    IOByteCount remaining;
-    void (*func)(addr64_t pa, unsigned int count) = 0;
-
-    switch (options)
-    {
-        case kIOMemoryIncoherentIOFlush:
-            func = &dcache_incoherent_io_flush64;
-            break;
-        case kIOMemoryIncoherentIOStore:
-            func = &dcache_incoherent_io_store64;
-            break;
-    }
+	IOReturn ret;
+	kern_allocation_name_t alloc;
+	kern_allocation_name_t mapName;
+	int16_t prior;
+
+	mapName = NULL;
+	prior = 0;
+	if (command) {
+		mapName = _mapName;
+		if (_dmaReferences) {
+			prior = OSAddAtomic16(-1, &_dmaReferences);
+		} else {
+			panic("_dmaReferences underflow");
+		}
+	}
 
-    if (!func)
-        return (kIOReturnUnsupported);
+	if (!mapLength) {
+		return kIOReturnSuccess;
+	}
 
-    remaining = length = min(length, getLength() - offset);
-    while (remaining)
-    // (process another target segment?)
-    {
-        addr64_t    dstAddr64;
-        IOByteCount dstLen;
+	ret = mapper->iovmUnmapMemory(this, command, mapAddress, mapLength);
 
-        dstAddr64 = getPhysicalSegment64(offset, &dstLen);
-        if (!dstAddr64)
-            break;
+	if ((alloc = mapper->fAllocName)) {
+		kern_allocation_update_size(alloc, -mapLength);
+		if ((1 == prior) && mapName && (VM_KERN_MEMORY_NONE != _kernelTag)) {
+			mapLength = _length;
+			kern_allocation_update_subtotal(mapName, _kernelTag, -mapLength);
+		}
+	}
 
-        // Clip segment length to remaining
-        if (dstLen > remaining)
-            dstLen = remaining;
+	return ret;
+}
 
-	(*func)(dstAddr64, dstLen);
+IOReturn
+IOGeneralMemoryDescriptor::dmaMap(
+	IOMapper                    * mapper,
+	IODMACommand                * command,
+	const IODMAMapSpecification * mapSpec,
+	uint64_t                      offset,
+	uint64_t                      length,
+	uint64_t                    * mapAddress,
+	uint64_t                    * mapLength)
+{
+	IOReturn          err = kIOReturnSuccess;
+	ioGMDData *       dataP;
+	IOOptionBits      type = _flags & kIOMemoryTypeMask;
 
-        offset    += dstLen;
-        remaining -= dstLen;
-    }
+	*mapAddress = 0;
+	if (kIOMemoryHostOnly & _flags) {
+		return kIOReturnSuccess;
+	}
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
 
-    return (remaining ? kIOReturnUnderrun : kIOReturnSuccess);
-}
+	if ((type == kIOMemoryTypePhysical) || (type == kIOMemoryTypePhysical64)
+	    || offset || (length != _length)) {
+		err = super::dmaMap(mapper, command, mapSpec, offset, length, mapAddress, mapLength);
+	} else if (_memoryEntries && _pages && (dataP = getDataP(_memoryEntries))) {
+		const ioPLBlock * ioplList = getIOPLList(dataP);
+		upl_page_info_t * pageList;
+		uint32_t          mapOptions = 0;
+
+		IODMAMapSpecification mapSpec;
+		bzero(&mapSpec, sizeof(mapSpec));
+		mapSpec.numAddressBits = dataP->fDMAMapNumAddressBits;
+		mapSpec.alignment = dataP->fDMAMapAlignment;
+
+		// For external UPLs the fPageInfo field points directly to
+		// the upl's upl_page_info_t array.
+		if (ioplList->fFlags & kIOPLExternUPL) {
+			pageList = (upl_page_info_t *) ioplList->fPageInfo;
+			mapOptions |= kIODMAMapPagingPath;
+		} else {
+			pageList = getPageList(dataP);
+		}
 
-#ifdef __ppc__
-extern vm_offset_t		static_memory_end;
-#define io_kernel_static_end	static_memory_end
-#else
-extern vm_offset_t		first_avail;
-#define io_kernel_static_end	first_avail
-#endif
+		if ((_length == ptoa_64(_pages)) && !(page_mask & ioplList->fPageOffset)) {
+			mapOptions |= kIODMAMapPageListFullyOccupied;
+		}
 
-static kern_return_t
-io_get_kernel_static_upl(
-	vm_map_t		/* map */,
-	vm_address_t		offset,
-	vm_size_t		*upl_size,
-	upl_t			*upl,
-	upl_page_info_array_t	page_list,
-	unsigned int		*count,
-	ppnum_t			*highest_page)
-{
-    unsigned int pageCount, page;
-    ppnum_t phys;
-    ppnum_t highestPage = 0;
-
-    pageCount = atop_32(*upl_size);
-    if (pageCount > *count)
-	pageCount = *count;
-
-    *upl = NULL;
-
-    for (page = 0; page < pageCount; page++)
-    {
-	phys = pmap_find_phys(kernel_pmap, ((addr64_t)offset) + ptoa_64(page));
-	if (!phys)
-	    break;
-	page_list[page].phys_addr = phys;
-	page_list[page].pageout	  = 0;
-	page_list[page].absent	  = 0;
-	page_list[page].dirty	  = 0;
-	page_list[page].precious  = 0;
-	page_list[page].device	  = 0;
-	if (phys > highestPage)
-	    highestPage = page;
-    }
-
-    *highest_page = highestPage;
-
-    return ((page >= pageCount) ? kIOReturnSuccess : kIOReturnVMError);
-}
-
-IOReturn IOGeneralMemoryDescriptor::wireVirtual(IODirection forDirection)
-{
-    IOOptionBits type = _flags & kIOMemoryTypeMask;
-    IOReturn error = kIOReturnNoMemory;
-    ioGMDData *dataP;
-    ppnum_t mapBase = 0;
-    IOMapper *mapper;
-    ipc_port_t sharedMem = (ipc_port_t) _memEntry;
-
-    assert(!_wireCount);
-    assert(kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type);
-
-    if (_pages >= gIOMaximumMappedIOPageCount)
-	return kIOReturnNoResources;
-
-    dataP = getDataP(_memoryEntries);
-    mapper = dataP->fMapper;
-    if (mapper && _pages)
-        mapBase = mapper->iovmAlloc(_pages);
-
-    // Note that appendBytes(NULL) zeros the data up to the
-    // desired length.
-    _memoryEntries->appendBytes(0, dataP->fPageCnt * sizeof(upl_page_info_t));
-    dataP = 0;	// May no longer be valid so lets not get tempted.
-
-    if (forDirection == kIODirectionNone)
-        forDirection = _direction;
-
-    int uplFlags;    // This Mem Desc's default flags for upl creation
-    switch (kIODirectionOutIn & forDirection)
-    {
-    case kIODirectionOut:
-        // Pages do not need to be marked as dirty on commit
-        uplFlags = UPL_COPYOUT_FROM;
-        _flags |= kIOMemoryPreparedReadOnly;
-        break;
-
-    case kIODirectionIn:
-    default:
-        uplFlags = 0;	// i.e. ~UPL_COPYOUT_FROM
-        break;
-    }
-    uplFlags |= UPL_SET_IO_WIRE | UPL_SET_LITE;
-
-#ifdef UPL_NEED_32BIT_ADDR
-    if (kIODirectionPrepareToPhys32 & forDirection) 
-	uplFlags |= UPL_NEED_32BIT_ADDR;
-#endif
+		assert(dataP->fDMAAccess);
+		mapOptions |= dataP->fDMAAccess;
 
-    // Find the appropriate vm_map for the given task
-    vm_map_t curMap;
-    if (_task == kernel_task && (kIOMemoryBufferPageable & _flags))
-        curMap = 0;
-    else
-        { curMap = get_task_map(_task); }
-
-    // Iterate over the vector of virtual ranges
-    Ranges vec = _ranges;
-    unsigned int pageIndex = 0;
-    IOByteCount mdOffset = 0;
-    ppnum_t highestPage = 0;
-    for (UInt range = 0; range < _rangesCount; range++) {
-        ioPLBlock iopl;
-	user_addr_t startPage;
-        IOByteCount numBytes;
-	ppnum_t highPage = 0;
-
-	// Get the startPage address and length of vec[range]
-	getAddrLenForInd(startPage, numBytes, type, vec, range);
-	iopl.fPageOffset = (short) startPage & PAGE_MASK;
-	numBytes += iopl.fPageOffset;
-	startPage = trunc_page_64(startPage);
-
-	if (mapper)
-	    iopl.fMappedBase = mapBase + pageIndex;
-	else
-	    iopl.fMappedBase = 0;
-
-	// Iterate over the current range, creating UPLs
-        while (numBytes) {
-            dataP = getDataP(_memoryEntries);
-	    vm_address_t kernelStart = (vm_address_t) startPage;
-            vm_map_t theMap;
-	    if (curMap)
-		theMap = curMap;
-	    else if (!sharedMem) {
-		assert(_task == kernel_task);
-		theMap = IOPageableMapForAddress(kernelStart);
-	    }
-	    else
-		theMap = NULL;
-
-            upl_page_info_array_t pageInfo = getPageList(dataP);
-            int ioplFlags = uplFlags;
-            upl_page_list_ptr_t baseInfo = &pageInfo[pageIndex];
-
-            vm_size_t ioplSize = round_page_32(numBytes);
-            unsigned int numPageInfo = atop_32(ioplSize);
-
-	    if (theMap == kernel_map && kernelStart < io_kernel_static_end) {
-		error = io_get_kernel_static_upl(theMap, 
-						kernelStart,
-						&ioplSize,
-						&iopl.fIOPL,
-						baseInfo,
-						&numPageInfo,
-						&highPage);
-	    }
-	    else if (sharedMem) {
-		error = memory_object_iopl_request(sharedMem, 
-						ptoa_32(pageIndex),
-						&ioplSize,
-						&iopl.fIOPL,
-						baseInfo,
-						&numPageInfo,
-						&ioplFlags);
-	    }
-	    else {
-		assert(theMap);
-		error = vm_map_create_upl(theMap,
-						startPage,
-						&ioplSize,
-						&iopl.fIOPL,
-						baseInfo,
-						&numPageInfo,
-						&ioplFlags);
-	    }
-
-            assert(ioplSize);
-            if (error != KERN_SUCCESS)
-                goto abortExit;
-
-	    if (iopl.fIOPL)
-		highPage = upl_get_highest_page(iopl.fIOPL);
-	    if (highPage > highestPage)
-		highestPage = highPage;
-
-            error = kIOReturnNoMemory;
-
-            if (baseInfo->device) {
-                numPageInfo = 1;
-                iopl.fFlags  = kIOPLOnDevice;
-                // Don't translate device memory at all 
-		if (mapper && mapBase) {
-		    mapper->iovmFree(mapBase, _pages);
-		    mapBase = 0;
-		    iopl.fMappedBase = 0;
-		}
-            }
-            else {
-                iopl.fFlags = 0;
-		if (mapper)
-                    mapper->iovmInsert(mapBase, pageIndex,
-                                       baseInfo, numPageInfo);
-            }
-
-            iopl.fIOMDOffset = mdOffset;
-            iopl.fPageInfo = pageIndex;
-
-	    if ((_flags & kIOMemoryAutoPrepare) && iopl.fIOPL)
-	    {
-		upl_commit(iopl.fIOPL, 0, 0);
-		upl_deallocate(iopl.fIOPL);
-		iopl.fIOPL = 0;
-	    }
-
-            if (!_memoryEntries->appendBytes(&iopl, sizeof(iopl))) {
-                // Clean up partial created and unsaved iopl
-                if (iopl.fIOPL) {
-                    upl_abort(iopl.fIOPL, 0);
-                    upl_deallocate(iopl.fIOPL);
-                }
-                goto abortExit;
-            }
-
-            // Check for a multiple iopl's in one virtual range
-            pageIndex += numPageInfo;
-            mdOffset -= iopl.fPageOffset;
-            if (ioplSize < numBytes) {
-                numBytes -= ioplSize;
-                startPage += ioplSize;
-                mdOffset += ioplSize;
-                iopl.fPageOffset = 0;
-		if (mapper)
-		    iopl.fMappedBase = mapBase + pageIndex;
-            }
-            else {
-                mdOffset += numBytes;
-                break;
-            }
-        }
-    }
-
-    _highestPage = highestPage;
-
-    return kIOReturnSuccess;
+		// Check for direct device non-paged memory
+		if (ioplList->fFlags & kIOPLOnDevice) {
+			mapOptions |= kIODMAMapPhysicallyContiguous;
+		}
 
-abortExit:
-    {
-        dataP = getDataP(_memoryEntries);
-        UInt done = getNumIOPL(_memoryEntries, dataP);
-        ioPLBlock *ioplList = getIOPLList(dataP);
-    
-        for (UInt range = 0; range < done; range++)
-	{
-	    if (ioplList[range].fIOPL) {
-             upl_abort(ioplList[range].fIOPL, 0);
-             upl_deallocate(ioplList[range].fIOPL);
-	    }
+		IODMAMapPageList dmaPageList =
+		{
+			.pageOffset    = (uint32_t)(ioplList->fPageOffset & page_mask),
+			.pageListCount = _pages,
+			.pageList      = &pageList[0]
+		};
+		err = mapper->iovmMapMemory(this, offset, length, mapOptions, &mapSpec,
+		    command, &dmaPageList, mapAddress, mapLength);
+
+		if (kIOReturnSuccess == err) {
+			dmaMapRecord(mapper, command, *mapLength);
+		}
 	}
-	(void) _memoryEntries->initWithBytes(dataP, sizeof(ioGMDData)); // == setLength()
 
-        if (mapper && mapBase)
-            mapper->iovmFree(mapBase, _pages);
-    }
-
-    return error;
+	return err;
 }
 
 /*
@@ -1974,21 +3719,43 @@ abortExit:
  * the memory after the I/O transfer finishes.  This method needn't
  * called for non-pageable memory.
  */
-IOReturn IOGeneralMemoryDescriptor::prepare(IODirection forDirection)
+
+IOReturn
+IOGeneralMemoryDescriptor::prepare(IODirection forDirection)
 {
-    IOReturn error    = kIOReturnSuccess;
-    IOOptionBits type = _flags & kIOMemoryTypeMask;
+	IOReturn     error    = kIOReturnSuccess;
+	IOOptionBits type = _flags & kIOMemoryTypeMask;
+
+	if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type)) {
+		return kIOReturnSuccess;
+	}
+
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
 
-    if (!_wireCount
-    && (kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type) ) {
-        error = wireVirtual(forDirection);
-        if (error)
-            return error;
-    }
+	if (_prepareLock) {
+		IOLockLock(_prepareLock);
+	}
+
+	if (kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type) {
+		error = wireVirtual(forDirection);
+	}
+
+	if (kIOReturnSuccess == error) {
+		if (1 == ++_wireCount) {
+			if (kIOMemoryClearEncrypt & _flags) {
+				performOperation(kIOMemoryClearEncrypted, 0, _length);
+			}
+		}
+	}
 
-    _wireCount++;
+	if (_prepareLock) {
+		IOLockUnlock(_prepareLock);
+	}
 
-    return kIOReturnSuccess;
+	return error;
 }
 
 /*
@@ -1999,1745 +3766,1387 @@ IOReturn IOGeneralMemoryDescriptor::prepare(IODirection forDirection)
  * issued; the prepare() and complete() must occur in pairs, before
  * before and after an I/O transfer involving pageable memory.
  */
- 
-IOReturn IOGeneralMemoryDescriptor::complete(IODirection /* forDirection */)
-{
-    assert(_wireCount);
 
-    if (!_wireCount)
-        return kIOReturnSuccess;
-
-    _wireCount--;
-    if (!_wireCount) {
+IOReturn
+IOGeneralMemoryDescriptor::complete(IODirection forDirection)
+{
 	IOOptionBits type = _flags & kIOMemoryTypeMask;
+	ioGMDData  * dataP;
 
-        if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type)) {
-            /* kIOMemoryTypePhysical */
-            // DO NOTHING
-        }
-        else {
-            ioGMDData * dataP = getDataP(_memoryEntries);
-            ioPLBlock *ioplList = getIOPLList(dataP);
-	    UInt count = getNumIOPL(_memoryEntries, dataP);
-
-            if (dataP->fMapper && _pages && ioplList[0].fMappedBase)
-                dataP->fMapper->iovmFree(ioplList[0].fMappedBase, _pages);
-
-            // Only complete iopls that we created which are for TypeVirtual
-            if (kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type) {
-                for (UInt ind = 0; ind < count; ind++)
-		    if (ioplList[ind].fIOPL) {
-			 upl_commit(ioplList[ind].fIOPL, 0, 0);
-			 upl_deallocate(ioplList[ind].fIOPL);
-		    }
-            }
-
-            (void) _memoryEntries->initWithBytes(dataP, sizeof(ioGMDData)); // == setLength()
-        }
-    }
-    return kIOReturnSuccess;
-}
-
-IOReturn IOGeneralMemoryDescriptor::doMap(
-	vm_map_t		addressMap,
-	IOVirtualAddress *	atAddress,
-	IOOptionBits		options,
-	IOByteCount		sourceOffset,
-	IOByteCount		length )
-{
-    kern_return_t kr;
-    ipc_port_t sharedMem = (ipc_port_t) _memEntry;
-
-    IOOptionBits type = _flags & kIOMemoryTypeMask;
-    Ranges vec = _ranges;
-
-    user_addr_t range0Addr = 0;
-    IOByteCount range0Len = 0;
-
-    if (vec.v)
-	getAddrLenForInd(range0Addr, range0Len, type, vec, 0);
-
-    // mapping source == dest? (could be much better)
-    if( _task
-    && (addressMap == get_task_map(_task)) && (options & kIOMapAnywhere)
-    && (1 == _rangesCount) && (0 == sourceOffset)
-    && range0Addr && (length <= range0Len) ) {
-	if (sizeof(user_addr_t) > 4 && ((UInt64) range0Addr) >> 32)
-	    return kIOReturnOverrun;	// Doesn't fit in 32bit return field
-	else {
-	    *atAddress = range0Addr;
-	    return( kIOReturnSuccess );
+	if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type)) {
+		return kIOReturnSuccess;
 	}
-    }
-
-    if( 0 == sharedMem) {
-
-        vm_size_t size = ptoa_32(_pages);
-
-        if( _task) {
-
-            memory_object_size_t actualSize = size;
-            kr = mach_make_memory_entry_64(get_task_map(_task),
-                        &actualSize, range0Addr,
-                        VM_PROT_READ | VM_PROT_WRITE, &sharedMem,
-                        NULL );
-
-            if( (KERN_SUCCESS == kr) && (actualSize != round_page_32(size))) {
-#if IOASSERT
-                IOLog("mach_make_memory_entry_64 (%08llx) size (%08lx:%08x)\n",
-                            range0Addr, (UInt32) actualSize, size);
-#endif
-                kr = kIOReturnVMError;
-                ipc_port_release_send( sharedMem );
-            }
-
-            if( KERN_SUCCESS != kr)
-                sharedMem = MACH_PORT_NULL;
-
-        } else do {	// _task == 0, must be physical
-
-            memory_object_t 	pager;
-	    unsigned int    	flags = 0;
-    	    addr64_t		pa;
-    	    IOPhysicalLength	segLen;
-
-	    pa = getPhysicalSegment64( sourceOffset, &segLen );
-
-            if( !reserved) {
-                reserved = IONew( ExpansionData, 1 );
-                if( !reserved)
-                    continue;
-            }
-            reserved->pagerContig = (1 == _rangesCount);
-	    reserved->memory = this;
-
-	    /*What cache mode do we need*/
-            switch(options & kIOMapCacheMask ) {
-
-		case kIOMapDefaultCache:
-		default:
-		    flags = IODefaultCacheBits(pa);
-		    break;
-	
-		case kIOMapInhibitCache:
-		    flags = DEVICE_PAGER_CACHE_INHIB | 
-				    DEVICE_PAGER_COHERENT | DEVICE_PAGER_GUARDED;
-		    break;
-	
-		case kIOMapWriteThruCache:
-		    flags = DEVICE_PAGER_WRITE_THROUGH |
-				    DEVICE_PAGER_COHERENT | DEVICE_PAGER_GUARDED;
-		    break;
-
-		case kIOMapCopybackCache:
-		    flags = DEVICE_PAGER_COHERENT;
-		    break;
-
-		case kIOMapWriteCombineCache:
-		    flags = DEVICE_PAGER_CACHE_INHIB |
-				    DEVICE_PAGER_COHERENT;
-		    break;
-            }
-
-	    flags |= reserved->pagerContig ? DEVICE_PAGER_CONTIGUOUS : 0;
-
-            pager = device_pager_setup( (memory_object_t) 0, (int) reserved, 
-								size, flags);
-            assert( pager );
-
-            if( pager) {
-                kr = mach_memory_object_memory_entry_64( (host_t) 1, false /*internal*/, 
-                            size, VM_PROT_READ | VM_PROT_WRITE, pager, &sharedMem );
-
-                assert( KERN_SUCCESS == kr );
-                if( KERN_SUCCESS != kr) {
-		    device_pager_deallocate( pager );
-                    pager = MACH_PORT_NULL;
-                    sharedMem = MACH_PORT_NULL;
-                }
-            }
-	    if( pager && sharedMem)
-		reserved->devicePager    = pager;
-	    else {
-		IODelete( reserved, ExpansionData, 1 );
-		reserved = 0;
-	    }
-
-        } while( false );
-
-        _memEntry = (void *) sharedMem;
-    }
-
-
-    if( 0 == sharedMem)
-      kr = kIOReturnVMError;
-    else
-      kr = super::doMap( addressMap, atAddress,
-                           options, sourceOffset, length );
-
-    return( kr );
-}
-
-IOReturn IOGeneralMemoryDescriptor::doUnmap(
-	vm_map_t		addressMap,
-	IOVirtualAddress	logical,
-	IOByteCount		length )
-{
-    // could be much better
-    if( _task && (addressMap == get_task_map(_task)) && (1 == _rangesCount)) {
-
-	IOOptionBits type = _flags & kIOMemoryTypeMask;
-	user_addr_t range0Addr;
-	IOByteCount range0Len;
-
-	getAddrLenForInd(range0Addr, range0Len, type, _ranges, 0);
-	if (logical == range0Addr && length <= range0Len)
-	    return( kIOReturnSuccess );
-    }
-
-    return( super::doUnmap( addressMap, logical, length ));
-}
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-OSDefineMetaClassAndAbstractStructors( IOMemoryMap, OSObject )
 
-/* inline function implementation */
-IOPhysicalAddress IOMemoryMap::getPhysicalAddress()
-    { return( getPhysicalSegment( 0, 0 )); }
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return kIOReturnNotAttached;
+	}
 
+	if (_prepareLock) {
+		IOLockLock(_prepareLock);
+	}
+	do{
+		assert(_wireCount);
+		if (!_wireCount) {
+			break;
+		}
+		dataP = getDataP(_memoryEntries);
+		if (!dataP) {
+			break;
+		}
 
-#undef super
-#define super IOMemoryMap
+		if (kIODirectionCompleteWithError & forDirection) {
+			dataP->fCompletionError = true;
+		}
 
-OSDefineMetaClassAndStructors(_IOMemoryMap, IOMemoryMap)
+		if ((kIOMemoryClearEncrypt & _flags) && (1 == _wireCount)) {
+			performOperation(kIOMemorySetEncrypted, 0, _length);
+		}
 
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+		_wireCount--;
+		if (!_wireCount || (kIODirectionCompleteWithDataValid & forDirection)) {
+			ioPLBlock *ioplList = getIOPLList(dataP);
+			UInt ind, count = getNumIOPL(_memoryEntries, dataP);
+
+			if (_wireCount) {
+				// kIODirectionCompleteWithDataValid & forDirection
+				if (kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type) {
+					vm_tag_t tag;
+					tag = getVMTag(kernel_map);
+					for (ind = 0; ind < count; ind++) {
+						if (ioplList[ind].fIOPL) {
+							iopl_valid_data(ioplList[ind].fIOPL, tag);
+						}
+					}
+				}
+			} else {
+				if (_dmaReferences) {
+					panic("complete() while dma active");
+				}
+
+				if (dataP->fMappedBaseValid) {
+					dmaUnmap(dataP->fMapper, NULL, 0, dataP->fMappedBase, dataP->fMappedLength);
+					dataP->fMappedBaseValid = dataP->fMappedBase = 0;
+				}
+#if IOTRACKING
+				if (dataP->fWireTracking.link.next) {
+					IOTrackingRemove(gIOWireTracking, &dataP->fWireTracking, ptoa(_pages));
+				}
+#endif /* IOTRACKING */
+				// Only complete iopls that we created which are for TypeVirtual
+				if (kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type) {
+					for (ind = 0; ind < count; ind++) {
+						if (ioplList[ind].fIOPL) {
+							if (dataP->fCompletionError) {
+								upl_abort(ioplList[ind].fIOPL, 0 /*!UPL_ABORT_DUMP_PAGES*/);
+							} else {
+								upl_commit(ioplList[ind].fIOPL, NULL, 0);
+							}
+							upl_deallocate(ioplList[ind].fIOPL);
+						}
+					}
+				} else if (kIOMemoryTypeUPL == type) {
+					upl_set_referenced(ioplList[0].fIOPL, false);
+				}
+
+				(void) _memoryEntries->initWithBytes(dataP, computeDataSize(0, 0)); // == setLength()
+
+				dataP->fPreparationID = kIOPreparationIDUnprepared;
+				_flags &= ~kIOMemoryPreparedReadOnly;
+			}
+		}
+	}while (false);
 
-bool _IOMemoryMap::initCompatible(
-	IOMemoryDescriptor *	_memory,
-	IOMemoryMap *		_superMap,
-        IOByteCount		_offset,
-        IOByteCount		_length )
-{
-
-    if( !super::init())
-	return( false);
-
-    if( (_offset + _length) > _superMap->getLength())
-	return( false);
-
-    _memory->retain();
-    memory	= _memory;
-    _superMap->retain();
-    superMap 	= _superMap;
-
-    offset	= _offset;
-    if( _length)
-        length	= _length;
-    else
-        length	= _memory->getLength();
-
-    options	= superMap->getMapOptions();
-    logical	= superMap->getVirtualAddress() + offset;
-
-    return( true );
-}
-
-bool _IOMemoryMap::initWithDescriptor(
-        IOMemoryDescriptor *	_memory,
-        task_t			intoTask,
-        IOVirtualAddress	toAddress,
-        IOOptionBits		_options,
-        IOByteCount		_offset,
-        IOByteCount		_length )
-{
-    bool ok;
-    bool redir = ((kIOMapUnique|kIOMapReference) == ((kIOMapUnique|kIOMapReference) & _options));
-
-    if ((!_memory) || (!intoTask))
-	return( false);
-
-    if( (_offset + _length) > _memory->getLength())
-	return( false);
-
-    if (!redir)
-    {
-	if (!super::init())
-	    return(false);
-	addressMap  = get_task_map(intoTask);
-	if( !addressMap)
-	    return( false);
-	vm_map_reference(addressMap);
-	addressTask = intoTask;
-	logical	    = toAddress;
-	options     = _options;
-    }
-
-    _memory->retain();
-
-    offset	= _offset;
-    if( _length)
-        length	= _length;
-    else
-        length	= _memory->getLength();
-
-    if( options & kIOMapStatic)
-	ok = true;
-    else
-	ok = (kIOReturnSuccess == _memory->doMap( addressMap, &toAddress,
-						  _options, offset, length ));
-    if (ok || redir)
-    {
-	if (memory)
-	    memory->release();
-	memory	= _memory;
-	logical = toAddress;
-    }
-    else
-    {
-        _memory->release();
-	if (!redir)
-	{
-	    logical = 0;
-	    memory = 0;
-	    vm_map_deallocate(addressMap);
-	    addressMap = 0;
+	if (_prepareLock) {
+		IOLockUnlock(_prepareLock);
 	}
-    }
 
-    return( ok );
+	return kIOReturnSuccess;
 }
 
-/* LP64todo - these need to expand */
-struct IOMemoryDescriptorMapAllocRef
+IOReturn
+IOGeneralMemoryDescriptor::doMap(
+	vm_map_t                __addressMap,
+	IOVirtualAddress *      __address,
+	IOOptionBits            options,
+	IOByteCount             __offset,
+	IOByteCount             __length )
 {
-    ipc_port_t		sharedMem;
-    vm_size_t		size;
-    vm_offset_t		mapped;
-    IOByteCount		sourceOffset;
-    IOOptionBits	options;
-};
-
-static kern_return_t IOMemoryDescriptorMapAlloc(vm_map_t map, void * _ref)
-{
-    IOMemoryDescriptorMapAllocRef * ref = (IOMemoryDescriptorMapAllocRef *)_ref;
-    IOReturn			    err;
-
-    do {
-        if( ref->sharedMem) {
-            vm_prot_t prot = VM_PROT_READ
-                            | ((ref->options & kIOMapReadOnly) ? 0 : VM_PROT_WRITE);
-
-            // set memory entry cache
-            vm_prot_t memEntryCacheMode = prot | MAP_MEM_ONLY;
-            switch (ref->options & kIOMapCacheMask)
-            {
-		case kIOMapInhibitCache:
-                    SET_MAP_MEM(MAP_MEM_IO, memEntryCacheMode);
-                    break;
-	
-		case kIOMapWriteThruCache:
-                    SET_MAP_MEM(MAP_MEM_WTHRU, memEntryCacheMode);
-                    break;
-
-		case kIOMapWriteCombineCache:
-                    SET_MAP_MEM(MAP_MEM_WCOMB, memEntryCacheMode);
-                    break;
-
-		case kIOMapCopybackCache:
-                    SET_MAP_MEM(MAP_MEM_COPYBACK, memEntryCacheMode);
-                    break;
-
-		case kIOMapDefaultCache:
-		default:
-                    SET_MAP_MEM(MAP_MEM_NOOP, memEntryCacheMode);
-                    break;
-            }
-
-            vm_size_t unused = 0;
-
-            err = mach_make_memory_entry( NULL /*unused*/, &unused, 0 /*unused*/, 
-                                            memEntryCacheMode, NULL, ref->sharedMem );
-            if (KERN_SUCCESS != err)
-                IOLog("MAP_MEM_ONLY failed %d\n", err);
-
-            err = vm_map( map,
-                            &ref->mapped,
-                            ref->size, 0 /* mask */, 
-                            (( ref->options & kIOMapAnywhere ) ? VM_FLAGS_ANYWHERE : VM_FLAGS_FIXED)
-                            | VM_MAKE_TAG(VM_MEMORY_IOKIT), 
-                            ref->sharedMem, ref->sourceOffset,
-                            false, // copy
-                            prot, // cur
-                            prot, // max
-                            VM_INHERIT_NONE);
-
-            if( KERN_SUCCESS != err) {
-                ref->mapped = 0;
-                continue;
-            }
-    
-        } else {
-    
-            err = vm_allocate( map, &ref->mapped, ref->size,
-                            ((ref->options & kIOMapAnywhere) ? VM_FLAGS_ANYWHERE : VM_FLAGS_FIXED)
-                            | VM_MAKE_TAG(VM_MEMORY_IOKIT) );
-    
-            if( KERN_SUCCESS != err) {
-                ref->mapped = 0;
-                continue;
-            }
-    
-            // we have to make sure that these guys don't get copied if we fork.
-            err = vm_inherit( map, ref->mapped, ref->size, VM_INHERIT_NONE);
-            assert( KERN_SUCCESS == err );
-        }
-
-    } while( false );
-
-    return( err );
-}
-
-
-IOReturn IOMemoryDescriptor::doMap(
-	vm_map_t		addressMap,
-	IOVirtualAddress *	atAddress,
-	IOOptionBits		options,
-	IOByteCount		sourceOffset,
-	IOByteCount		length )
-{
-    IOReturn		err = kIOReturnSuccess;
-    memory_object_t	pager;
-    vm_address_t	logical;
-    IOByteCount		pageOffset;
-    IOPhysicalAddress	sourceAddr;
-    IOMemoryDescriptorMapAllocRef	ref;
-
-    ref.sharedMem	= (ipc_port_t) _memEntry;
-    ref.sourceOffset	= sourceOffset;
-    ref.options		= options;
-
-    do {
-
-        if( 0 == length)
-            length = getLength();
-
-	sourceAddr = getSourceSegment( sourceOffset, NULL );
-	pageOffset = sourceAddr - trunc_page_32( sourceAddr );
-
-	ref.size = round_page_32( length + pageOffset );
-
-	if ((kIOMapReference|kIOMapUnique) == ((kIOMapReference|kIOMapUnique) & options))
-	{
-	    upl_t	  redirUPL2;
-	    vm_size_t	  size;
-	    int		  flags;
-
-	    _IOMemoryMap * mapping = (_IOMemoryMap *) *atAddress;
-	    ref.mapped = mapping->getVirtualAddress();
-    
-	    if (!_memEntry)
-	    {
-		err = kIOReturnNotReadable;
-		continue;
-	    }
-
-	    size = length;
-	    flags = UPL_COPYOUT_FROM | UPL_SET_INTERNAL 
-			| UPL_SET_LITE | UPL_SET_IO_WIRE | UPL_BLOCK_ACCESS;
-
-	    if (KERN_SUCCESS != memory_object_iopl_request((ipc_port_t) _memEntry, 0, &size, &redirUPL2,
-					    NULL, NULL,
-					    &flags))
-		redirUPL2 = NULL;
-
-	    err = upl_transpose(redirUPL2, mapping->redirUPL);
-	    if (kIOReturnSuccess != err)
-	    {
-		IOLog("upl_transpose(%x)\n", err);
-		err = kIOReturnSuccess;
-	    }
-
-	    if (redirUPL2)
-	    {
-		upl_commit(redirUPL2, NULL, 0);
-		upl_deallocate(redirUPL2);
-		redirUPL2 = 0;
-	    }
-	    {
-		// swap the memEntries since they now refer to different vm_objects
-		void * me = _memEntry;
-		_memEntry = mapping->memory->_memEntry;
-		mapping->memory->_memEntry = me;
-	    }
-	}
-	else
-	{
-    
-	    logical = *atAddress;
-	    if( options & kIOMapAnywhere) 
-		// vm_map looks for addresses above here, even when VM_FLAGS_ANYWHERE
-		ref.mapped = 0;
-	    else {
-		ref.mapped = trunc_page_32( logical );
-		if( (logical - ref.mapped) != pageOffset) {
-		    err = kIOReturnVMError;
-		    continue;
-		}
-	    }
-    
-	    if( ref.sharedMem && (addressMap == kernel_map) && (kIOMemoryBufferPageable & _flags))
-		err = IOIteratePageableMaps( ref.size, &IOMemoryDescriptorMapAlloc, &ref );
-	    else
-		err = IOMemoryDescriptorMapAlloc( addressMap, &ref );
-	}
-
-        if( err != KERN_SUCCESS)
-            continue;
-
-        if( reserved)
-            pager = (memory_object_t) reserved->devicePager;
-        else
-            pager = MACH_PORT_NULL;
-
-        if( !ref.sharedMem || pager )
-            err = handleFault( pager, addressMap, ref.mapped, sourceOffset, length, options );
-
-    } while( false );
-
-    if( err != KERN_SUCCESS) {
-        if( ref.mapped)
-            doUnmap( addressMap, ref.mapped, ref.size );
-        *atAddress = NULL;
-    } else
-        *atAddress = ref.mapped + pageOffset;
-
-    return( err );
-}
-
-enum {
-    kIOMemoryRedirected	= 0x00010000
-};
-
-IOReturn IOMemoryDescriptor::handleFault(
-        void *			_pager,
-	vm_map_t		addressMap,
-	IOVirtualAddress	address,
-	IOByteCount		sourceOffset,
-	IOByteCount		length,
-        IOOptionBits		options )
-{
-    IOReturn		err = kIOReturnSuccess;
-    memory_object_t	pager = (memory_object_t) _pager;
-    vm_size_t		size;
-    vm_size_t		bytes;
-    vm_size_t		page;
-    IOByteCount		pageOffset;
-    IOByteCount		pagerOffset;
-    IOPhysicalLength	segLen;
-    addr64_t		physAddr;
-
-    if( !addressMap) {
-
-        if( kIOMemoryRedirected & _flags) {
-#ifdef DEBUG
-            IOLog("sleep mem redirect %p, %lx\n", this, sourceOffset);
-#endif
-            do {
-	    	SLEEP;
-            } while( kIOMemoryRedirected & _flags );
-        }
-
-        return( kIOReturnSuccess );
-    }
-
-    physAddr = getPhysicalSegment64( sourceOffset, &segLen );
-    assert( physAddr );
-    pageOffset = physAddr - trunc_page_64( physAddr );
-    pagerOffset = sourceOffset;
-
-    size = length + pageOffset;
-    physAddr -= pageOffset;
-
-    segLen += pageOffset;
-    bytes = size;
-    do {
-	// in the middle of the loop only map whole pages
-	if( segLen >= bytes)
-	    segLen = bytes;
-	else if( segLen != trunc_page_32( segLen))
-	    err = kIOReturnVMError;
-        if( physAddr != trunc_page_64( physAddr))
-	    err = kIOReturnBadArgument;
-
-#ifdef DEBUG
-	if( kIOLogMapping & gIOKitDebug)
-	    IOLog("_IOMemoryMap::map(%p) %08lx->%08qx:%08lx\n",
-                addressMap, address + pageOffset, physAddr + pageOffset,
-		segLen - pageOffset);
-#endif
-
-        if( pager) {
-            if( reserved && reserved->pagerContig) {
-                IOPhysicalLength	allLen;
-                addr64_t		allPhys;
-
-                allPhys = getPhysicalSegment64( 0, &allLen );
-                assert( allPhys );
-                err = device_pager_populate_object( pager, 0, allPhys >> PAGE_SHIFT, round_page_32(allLen) );
-
-            } else {
-
-	    for( page = 0;
-                     (page < segLen) && (KERN_SUCCESS == err);
-                     page += page_size) {
-                        err = device_pager_populate_object(pager, pagerOffset,
-                        	(ppnum_t)((physAddr + page) >> PAGE_SHIFT), page_size);
-			pagerOffset += page_size;
-                }
-            }
-            assert( KERN_SUCCESS == err );
-            if( err)
-                break;
-        }
-
-	/*  *** ALERT *** */
-	/*  *** Temporary Workaround *** */
-
-	/* This call to vm_fault causes an early pmap level resolution	*/
-	/* of the mappings created above.  Need for this is in absolute	*/
-	/* violation of the basic tenet that the pmap layer is a cache.	*/
-	/* Further, it implies a serious I/O architectural violation on	*/
-	/* the part of some user of the mapping.  As of this writing, 	*/
-	/* the call to vm_fault is needed because the NVIDIA driver 	*/
-	/* makes a call to pmap_extract.  The NVIDIA driver needs to be	*/
-	/* fixed as soon as possible.  The NVIDIA driver should not 	*/
-	/* need to query for this info as it should know from the doMap	*/
-	/* call where the physical memory is mapped.  When a query is 	*/
-	/* necessary to find a physical mapping, it should be done 	*/
-	/* through an iokit call which includes the mapped memory 	*/
-	/* handle.  This is required for machine architecture independence.*/
-
-	if(!(kIOMemoryRedirected & _flags)) {
-		vm_fault(addressMap, 
-			 (vm_map_offset_t)address, 
-			 VM_PROT_READ|VM_PROT_WRITE, 
-			 FALSE, THREAD_UNINT, NULL, 
-			 (vm_map_offset_t)0);
-	}
-
-	/*  *** Temporary Workaround *** */
-	/*  *** ALERT *** */
-
-	sourceOffset += segLen - pageOffset;
-	address += segLen;
-	bytes -= segLen;
-	pageOffset = 0;
-
-    } while( bytes
-	&& (physAddr = getPhysicalSegment64( sourceOffset, &segLen )));
-
-    if( bytes)
-        err = kIOReturnBadArgument;
-
-    return( err );
-}
-
-IOReturn IOMemoryDescriptor::doUnmap(
-	vm_map_t		addressMap,
-	IOVirtualAddress	logical,
-	IOByteCount		length )
-{
-    IOReturn	err;
-
-#ifdef DEBUG
-    if( kIOLogMapping & gIOKitDebug)
-	kprintf("IOMemoryDescriptor::doUnmap(%x) %08x:%08x\n",
-                addressMap, logical, length );
-#endif
-
-    if( true /* && (addressMap == kernel_map) || (addressMap == get_task_map(current_task()))*/) {
-
-        if( _memEntry && (addressMap == kernel_map) && (kIOMemoryBufferPageable & _flags))
-            addressMap = IOPageableMapForAddress( logical );
-
-        err = vm_deallocate( addressMap, logical, length );
-
-    } else
-        err = kIOReturnSuccess;
+#ifndef __LP64__
+	if (!(kIOMap64Bit & options)) {
+		panic("IOGeneralMemoryDescriptor::doMap !64bit");
+	}
+#endif /* !__LP64__ */
 
-    return( err );
-}
+	kern_return_t  err;
 
-IOReturn IOMemoryDescriptor::redirect( task_t safeTask, bool doRedirect )
-{
-    IOReturn		err = kIOReturnSuccess;
-    _IOMemoryMap *	mapping = 0;
-    OSIterator *	iter;
+	IOMemoryMap *  mapping = (IOMemoryMap *) *__address;
+	mach_vm_size_t offset  = mapping->fOffset + __offset;
+	mach_vm_size_t length  = mapping->fLength;
 
-    LOCK;
+	IOOptionBits type = _flags & kIOMemoryTypeMask;
+	Ranges vec = _ranges;
 
-    if( doRedirect)
-        _flags |= kIOMemoryRedirected;
-    else
-        _flags &= ~kIOMemoryRedirected;
+	mach_vm_address_t range0Addr = 0;
+	mach_vm_size_t    range0Len = 0;
 
-    do {
-	if( (iter = OSCollectionIterator::withCollection( _mappings))) {
-	    while( (mapping = (_IOMemoryMap *) iter->getNextObject()))
-		mapping->redirect( safeTask, doRedirect );
+	if ((offset >= _length) || ((offset + length) > _length)) {
+		return kIOReturnBadArgument;
+	}
 
-	    iter->release();
+	assert(!(kIOMemoryRemote & _flags));
+	if (kIOMemoryRemote & _flags) {
+		return 0;
 	}
-    } while( false );
 
-    if (!doRedirect)
-    {
-        WAKEUP;
-    }
+	if (vec.v) {
+		getAddrLenForInd(range0Addr, range0Len, type, vec, 0);
+	}
 
-    UNLOCK;
+	// mapping source == dest? (could be much better)
+	if (_task
+	    && (mapping->fAddressTask == _task)
+	    && (mapping->fAddressMap == get_task_map(_task))
+	    && (options & kIOMapAnywhere)
+	    && (!(kIOMapUnique & options))
+	    && (1 == _rangesCount)
+	    && (0 == offset)
+	    && range0Addr
+	    && (length <= range0Len)) {
+		mapping->fAddress = range0Addr;
+		mapping->fOptions |= kIOMapStatic;
+
+		return kIOReturnSuccess;
+	}
 
-    // temporary binary compatibility
-    IOSubMemoryDescriptor * subMem;
-    if( (subMem = OSDynamicCast( IOSubMemoryDescriptor, this)))
-	err = subMem->redirect( safeTask, doRedirect );
-    else
-	err = kIOReturnSuccess;
+	if (!_memRef) {
+		IOOptionBits createOptions = 0;
+		if (!(kIOMapReadOnly & options)) {
+			createOptions |= kIOMemoryReferenceWrite;
+#if DEVELOPMENT || DEBUG
+			if ((kIODirectionOut == (kIODirectionOutIn & _flags))
+			    && (!reserved || (reserved->creator != mapping->fAddressTask))) {
+				OSReportWithBacktrace("warning: creating writable mapping from IOMemoryDescriptor(kIODirectionOut) - use kIOMapReadOnly or change direction");
+			}
+#endif
+		}
+		err = memoryReferenceCreate(createOptions, &_memRef);
+		if (kIOReturnSuccess != err) {
+			return err;
+		}
+	}
 
-    return( err );
-}
+	memory_object_t pager;
+	pager = (memory_object_t) (reserved ? reserved->dp.devicePager : NULL);
+
+	// <upl_transpose //
+	if ((kIOMapReference | kIOMapUnique) == ((kIOMapReference | kIOMapUnique) & options)) {
+		do{
+			upl_t               redirUPL2;
+			upl_size_t          size;
+			upl_control_flags_t flags;
+			unsigned int        lock_count;
+
+			if (!_memRef || (1 != _memRef->count)) {
+				err = kIOReturnNotReadable;
+				break;
+			}
+
+			size = round_page(mapping->fLength);
+			flags = UPL_COPYOUT_FROM | UPL_SET_INTERNAL
+			    | UPL_SET_LITE | UPL_SET_IO_WIRE | UPL_BLOCK_ACCESS;
+
+			if (KERN_SUCCESS != memory_object_iopl_request(_memRef->entries[0].entry, 0, &size, &redirUPL2,
+			    NULL, NULL,
+			    &flags, getVMTag(kernel_map))) {
+				redirUPL2 = NULL;
+			}
+
+			for (lock_count = 0;
+			    IORecursiveLockHaveLock(gIOMemoryLock);
+			    lock_count++) {
+				UNLOCK;
+			}
+			err = upl_transpose(redirUPL2, mapping->fRedirUPL);
+			for (;
+			    lock_count;
+			    lock_count--) {
+				LOCK;
+			}
+
+			if (kIOReturnSuccess != err) {
+				IOLog("upl_transpose(%x)\n", err);
+				err = kIOReturnSuccess;
+			}
+
+			if (redirUPL2) {
+				upl_commit(redirUPL2, NULL, 0);
+				upl_deallocate(redirUPL2);
+				redirUPL2 = NULL;
+			}
+			{
+				// swap the memEntries since they now refer to different vm_objects
+				IOMemoryReference * me = _memRef;
+				_memRef = mapping->fMemory->_memRef;
+				mapping->fMemory->_memRef = me;
+			}
+			if (pager) {
+				err = populateDevicePager( pager, mapping->fAddressMap, mapping->fAddress, offset, length, options );
+			}
+		}while (false);
+	}
+	// upl_transpose> //
+	else {
+		err = memoryReferenceMap(_memRef, mapping->fAddressMap, offset, length, options, &mapping->fAddress);
+#if IOTRACKING
+		if ((err == KERN_SUCCESS) && ((kIOTracking & gIOKitDebug) || _task)) {
+			// only dram maps in the default on developement case
+			IOTrackingAddUser(gIOMapTracking, &mapping->fTracking, mapping->fLength);
+		}
+#endif /* IOTRACKING */
+		if ((err == KERN_SUCCESS) && pager) {
+			err = populateDevicePager(pager, mapping->fAddressMap, mapping->fAddress, offset, length, options);
+
+			if (err != KERN_SUCCESS) {
+				doUnmap(mapping->fAddressMap, (IOVirtualAddress) mapping, 0);
+			} else if (kIOMapDefaultCache == (options & kIOMapCacheMask)) {
+				mapping->fOptions |= ((_flags & kIOMemoryBufferCacheMask) >> kIOMemoryBufferCacheShift);
+			}
+		}
+	}
 
-IOReturn IOSubMemoryDescriptor::redirect( task_t safeTask, bool doRedirect )
-{
-    return( _parent->redirect( safeTask, doRedirect ));
+	return err;
 }
 
-IOReturn _IOMemoryMap::redirect( task_t safeTask, bool doRedirect )
+#if IOTRACKING
+IOReturn
+IOMemoryMapTracking(IOTrackingUser * tracking, task_t * task,
+    mach_vm_address_t * address, mach_vm_size_t * size)
 {
-    IOReturn err = kIOReturnSuccess;
-
-    if( superMap) {
-//        err = ((_IOMemoryMap *)superMap)->redirect( safeTask, doRedirect );
-    } else {
+#define iomap_offsetof(type, field) ((size_t)(&((type *)NULL)->field))
 
-        LOCK;
-
-	do
-	{
-	    if (!logical)
-		break;
-	    if (!addressMap)
-		break;
+	IOMemoryMap * map = (typeof(map))(((uintptr_t) tracking) - iomap_offsetof(IOMemoryMap, fTracking));
 
-	    if ((!safeTask || (get_task_map(safeTask) != addressMap))
-	      && (0 == (options & kIOMapStatic)))
-	    {
-		IOUnmapPages( addressMap, logical, length );
-		if(!doRedirect && safeTask
-		 && (((memory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical) 
-		    || ((memory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64)))
-		 {
-		    err = vm_deallocate( addressMap, logical, length );
-		    err = memory->doMap( addressMap, &logical,
-					 (options & ~kIOMapAnywhere) /*| kIOMapReserve*/,
-					 offset, length );
-		} else
-		    err = kIOReturnSuccess;
-#ifdef DEBUG
-		IOLog("IOMemoryMap::redirect(%d, %p) %x:%lx from %p\n", doRedirect, this, logical, length, addressMap);
-#endif
-	    }
-	    else if (kIOMapWriteCombineCache == (options & kIOMapCacheMask))
-	    {
-		IOOptionBits newMode;
-		newMode = (options & ~kIOMapCacheMask) | (doRedirect ? kIOMapInhibitCache : kIOMapWriteCombineCache);
-		IOProtectCacheMode(addressMap, logical, length, newMode);
-	    }
+	if (!map->fAddressMap || (map->fAddressMap != get_task_map(map->fAddressTask))) {
+		return kIOReturnNotReady;
 	}
-	while (false);
-
-	UNLOCK;
-    }
 
-    if ((((memory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
-	 || ((memory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64))
-     && safeTask
-     && (doRedirect != (0 != (memory->_flags & kIOMemoryRedirected))))
-	memory->redirect(safeTask, doRedirect);
+	*task    = map->fAddressTask;
+	*address = map->fAddress;
+	*size    = map->fLength;
 
-    return( err );
+	return kIOReturnSuccess;
 }
+#endif /* IOTRACKING */
 
-IOReturn _IOMemoryMap::unmap( void )
+IOReturn
+IOGeneralMemoryDescriptor::doUnmap(
+	vm_map_t                addressMap,
+	IOVirtualAddress        __address,
+	IOByteCount             __length )
 {
-    IOReturn	err;
-
-    LOCK;
-
-    if( logical && addressMap && (0 == superMap)
-	&& (0 == (options & kIOMapStatic))) {
-
-        err = memory->doUnmap( addressMap, logical, length );
-        vm_map_deallocate(addressMap);
-        addressMap = 0;
+	return super::doUnmap(addressMap, __address, __length);
+}
 
-    } else
-	err = kIOReturnSuccess;
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-    logical = 0;
+#undef super
+#define super OSObject
 
-    UNLOCK;
+OSDefineMetaClassAndStructors( IOMemoryMap, OSObject )
 
-    return( err );
-}
+OSMetaClassDefineReservedUnused(IOMemoryMap, 0);
+OSMetaClassDefineReservedUnused(IOMemoryMap, 1);
+OSMetaClassDefineReservedUnused(IOMemoryMap, 2);
+OSMetaClassDefineReservedUnused(IOMemoryMap, 3);
+OSMetaClassDefineReservedUnused(IOMemoryMap, 4);
+OSMetaClassDefineReservedUnused(IOMemoryMap, 5);
+OSMetaClassDefineReservedUnused(IOMemoryMap, 6);
+OSMetaClassDefineReservedUnused(IOMemoryMap, 7);
 
-void _IOMemoryMap::taskDied( void )
+/* ex-inline function implementation */
+IOPhysicalAddress
+IOMemoryMap::getPhysicalAddress()
 {
-    LOCK;
-    if( addressMap) {
-        vm_map_deallocate(addressMap);
-        addressMap = 0;
-    }
-    addressTask	= 0;
-    logical	= 0;
-    UNLOCK;
+	return getPhysicalSegment( 0, NULL );
 }
 
-// Overload the release mechanism.  All mappings must be a member
-// of a memory descriptors _mappings set.  This means that we
-// always have 2 references on a mapping.  When either of these mappings
-// are released we need to free ourselves.
-void _IOMemoryMap::taggedRelease(const void *tag) const
-{
-    LOCK;
-    super::taggedRelease(tag, 2);
-    UNLOCK;
-}
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-void _IOMemoryMap::free()
+bool
+IOMemoryMap::init(
+	task_t                  intoTask,
+	mach_vm_address_t       toAddress,
+	IOOptionBits            _options,
+	mach_vm_size_t          _offset,
+	mach_vm_size_t          _length )
 {
-    unmap();
-
-    if( memory) {
-        LOCK;
-	memory->removeMapping( this);
-	UNLOCK;
-	memory->release();
-    }
+	if (!intoTask) {
+		return false;
+	}
 
-    if (owner && (owner != memory))
-    {
-        LOCK;
-	owner->removeMapping(this);
-	UNLOCK;
-    }
+	if (!super::init()) {
+		return false;
+	}
 
-    if( superMap)
-	superMap->release();
+	fAddressMap  = get_task_map(intoTask);
+	if (!fAddressMap) {
+		return false;
+	}
+	vm_map_reference(fAddressMap);
 
-    if (redirUPL) {
-	upl_commit(redirUPL, NULL, 0);
-	upl_deallocate(redirUPL);
-    }
+	fAddressTask = intoTask;
+	fOptions     = _options;
+	fLength      = _length;
+	fOffset      = _offset;
+	fAddress     = toAddress;
 
-    super::free();
+	return true;
 }
 
-IOByteCount _IOMemoryMap::getLength()
+bool
+IOMemoryMap::setMemoryDescriptor(IOMemoryDescriptor * _memory, mach_vm_size_t _offset)
 {
-    return( length );
-}
+	if (!_memory) {
+		return false;
+	}
 
-IOVirtualAddress _IOMemoryMap::getVirtualAddress()
-{
-    return( logical);
-}
+	if (!fSuperMap) {
+		if ((_offset + fLength) > _memory->getLength()) {
+			return false;
+		}
+		fOffset = _offset;
+	}
+
+	_memory->retain();
+	if (fMemory) {
+		if (fMemory != _memory) {
+			fMemory->removeMapping(this);
+		}
+		fMemory->release();
+	}
+	fMemory = _memory;
 
-task_t _IOMemoryMap::getAddressTask()
-{
-    if( superMap)
-	return( superMap->getAddressTask());
-    else
-        return( addressTask);
+	return true;
 }
 
-IOOptionBits _IOMemoryMap::getMapOptions()
+IOReturn
+IOMemoryDescriptor::doMap(
+	vm_map_t                __addressMap,
+	IOVirtualAddress *      __address,
+	IOOptionBits            options,
+	IOByteCount             __offset,
+	IOByteCount             __length )
 {
-    return( options);
+	return kIOReturnUnsupported;
 }
 
-IOMemoryDescriptor * _IOMemoryMap::getMemoryDescriptor()
+IOReturn
+IOMemoryDescriptor::handleFault(
+	void *                  _pager,
+	mach_vm_size_t          sourceOffset,
+	mach_vm_size_t          length)
 {
-    return( memory );
+	if (kIOMemoryRedirected & _flags) {
+#if DEBUG
+		IOLog("sleep mem redirect %p, %qx\n", this, sourceOffset);
+#endif
+		do {
+			SLEEP;
+		} while (kIOMemoryRedirected & _flags);
+	}
+	return kIOReturnSuccess;
 }
 
-_IOMemoryMap * _IOMemoryMap::copyCompatible(
-		IOMemoryDescriptor *	owner,
-                task_t			task,
-                IOVirtualAddress	toAddress,
-                IOOptionBits		_options,
-                IOByteCount		_offset,
-                IOByteCount		_length )
+IOReturn
+IOMemoryDescriptor::populateDevicePager(
+	void *                  _pager,
+	vm_map_t                addressMap,
+	mach_vm_address_t       address,
+	mach_vm_size_t          sourceOffset,
+	mach_vm_size_t          length,
+	IOOptionBits            options )
 {
-    _IOMemoryMap * mapping;
+	IOReturn            err = kIOReturnSuccess;
+	memory_object_t     pager = (memory_object_t) _pager;
+	mach_vm_size_t      size;
+	mach_vm_size_t      bytes;
+	mach_vm_size_t      page;
+	mach_vm_size_t      pageOffset;
+	mach_vm_size_t      pagerOffset;
+	IOPhysicalLength    segLen, chunk;
+	addr64_t            physAddr;
+	IOOptionBits        type;
+
+	type = _flags & kIOMemoryTypeMask;
+
+	if (reserved->dp.pagerContig) {
+		sourceOffset = 0;
+		pagerOffset  = 0;
+	}
 
-    if( (!task) || (!addressMap) || (addressMap != get_task_map(task)))
-	return( 0 );
-    if( options & kIOMapUnique)
-	return( 0 );
-    if( (options ^ _options) & kIOMapReadOnly)
-	return( 0 );
-    if( (kIOMapDefaultCache != (_options & kIOMapCacheMask)) 
-     && ((options ^ _options) & kIOMapCacheMask))
-	return( 0 );
+	physAddr = getPhysicalSegment( sourceOffset, &segLen, kIOMemoryMapperNone );
+	assert( physAddr );
+	pageOffset = physAddr - trunc_page_64( physAddr );
+	pagerOffset = sourceOffset;
+
+	size = length + pageOffset;
+	physAddr -= pageOffset;
+
+	segLen += pageOffset;
+	bytes = size;
+	do{
+		// in the middle of the loop only map whole pages
+		if (segLen >= bytes) {
+			segLen = bytes;
+		} else if (segLen != trunc_page_64(segLen)) {
+			err = kIOReturnVMError;
+		}
+		if (physAddr != trunc_page_64(physAddr)) {
+			err = kIOReturnBadArgument;
+		}
 
-    if( (0 == (_options & kIOMapAnywhere)) && (logical != toAddress))
-	return( 0 );
+		if (kIOReturnSuccess != err) {
+			break;
+		}
 
-    if( _offset < offset)
-	return( 0 );
+#if DEBUG || DEVELOPMENT
+		if ((kIOMemoryTypeUPL != type)
+		    && pmap_has_managed_page(atop_64(physAddr), atop_64(physAddr + segLen - 1))) {
+			OSReportWithBacktrace("IOMemoryDescriptor physical with managed page 0x%qx:0x%qx", physAddr, segLen);
+		}
+#endif /* DEBUG || DEVELOPMENT */
+
+		chunk = (reserved->dp.pagerContig ? round_page(segLen) : page_size);
+		for (page = 0;
+		    (page < segLen) && (KERN_SUCCESS == err);
+		    page += chunk) {
+			err = device_pager_populate_object(pager, pagerOffset,
+			    (ppnum_t)(atop_64(physAddr + page)), chunk);
+			pagerOffset += chunk;
+		}
 
-    _offset -= offset;
+		assert(KERN_SUCCESS == err);
+		if (err) {
+			break;
+		}
 
-    if( (_offset + _length) > length)
-	return( 0 );
+		// This call to vm_fault causes an early pmap level resolution
+		// of the mappings created above for kernel mappings, since
+		// faulting in later can't take place from interrupt level.
+		if ((addressMap == kernel_map) && !(kIOMemoryRedirected & _flags)) {
+			err = vm_fault(addressMap,
+			    (vm_map_offset_t)trunc_page_64(address),
+			    options & kIOMapReadOnly ? VM_PROT_READ : VM_PROT_READ | VM_PROT_WRITE,
+			    FALSE, VM_KERN_MEMORY_NONE,
+			    THREAD_UNINT, NULL,
+			    (vm_map_offset_t)0);
+
+			if (KERN_SUCCESS != err) {
+				break;
+			}
+		}
 
-    if( (length == _length) && (!_offset)) {
-        retain();
-	mapping = this;
+		sourceOffset += segLen - pageOffset;
+		address += segLen;
+		bytes -= segLen;
+		pageOffset = 0;
+	}while (bytes && (physAddr = getPhysicalSegment( sourceOffset, &segLen, kIOMemoryMapperNone )));
 
-    } else {
-        mapping = new _IOMemoryMap;
-        if( mapping
-        && !mapping->initCompatible( owner, this, _offset, _length )) {
-            mapping->release();
-            mapping = 0;
-        }
-    }
+	if (bytes) {
+		err = kIOReturnBadArgument;
+	}
 
-    return( mapping );
+	return err;
 }
 
-IOPhysicalAddress 
-_IOMemoryMap::getPhysicalSegment( IOByteCount _offset, IOPhysicalLength * _length)
+IOReturn
+IOMemoryDescriptor::doUnmap(
+	vm_map_t                addressMap,
+	IOVirtualAddress        __address,
+	IOByteCount             __length )
 {
-    IOPhysicalAddress	address;
-
-    LOCK;
-    address = memory->getPhysicalSegment( offset + _offset, _length );
-    UNLOCK;
-
-    return( address );
-}
+	IOReturn          err;
+	IOMemoryMap *     mapping;
+	mach_vm_address_t address;
+	mach_vm_size_t    length;
 
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-#undef super
-#define super OSObject
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+	if (__length) {
+		panic("doUnmap");
+	}
 
-void IOMemoryDescriptor::initialize( void )
-{
-    if( 0 == gIOMemoryLock)
-	gIOMemoryLock = IORecursiveLockAlloc();
+	mapping = (IOMemoryMap *) __address;
+	addressMap = mapping->fAddressMap;
+	address    = mapping->fAddress;
+	length     = mapping->fLength;
 
-    IORegistryEntry::getRegistryRoot()->setProperty(kIOMaximumMappedIOByteCountKey,
-						    ptoa_64(gIOMaximumMappedIOPageCount), 64);
-    if (!gIOCopyMapper)
-    {
-    	IOMapper *
-	mapper = new IOCopyMapper;
-	if (mapper)
-	{
-	    if (mapper->init() && mapper->start(NULL))
-		gIOCopyMapper = (IOCopyMapper *) mapper;
-	    else
-		mapper->release();
+	if (kIOMapOverwrite & mapping->fOptions) {
+		err = KERN_SUCCESS;
+	} else {
+		if ((addressMap == kernel_map) && (kIOMemoryBufferPageable & _flags)) {
+			addressMap = IOPageableMapForAddress( address );
+		}
+#if DEBUG
+		if (kIOLogMapping & gIOKitDebug) {
+			IOLog("IOMemoryDescriptor::doUnmap map %p, 0x%qx:0x%qx\n",
+			    addressMap, address, length );
+		}
+#endif
+		err = mach_vm_deallocate( addressMap, address, length );
 	}
-    }
-
-    gIOLastPage = IOGetLastPageNumber();
-}
 
-void IOMemoryDescriptor::free( void )
-{
-    if( _mappings)
-	_mappings->release();
+#if IOTRACKING
+	IOTrackingRemoveUser(gIOMapTracking, &mapping->fTracking);
+#endif /* IOTRACKING */
 
-    super::free();
+	return err;
 }
 
-IOMemoryMap * IOMemoryDescriptor::setMapping(
-	task_t			intoTask,
-	IOVirtualAddress	mapAddress,
-	IOOptionBits		options )
+IOReturn
+IOMemoryDescriptor::redirect( task_t safeTask, bool doRedirect )
 {
-    _IOMemoryMap *		newMap;
+	IOReturn            err = kIOReturnSuccess;
+	IOMemoryMap *       mapping = NULL;
+	OSIterator *        iter;
 
-    newMap = new _IOMemoryMap;
+	LOCK;
 
-    LOCK;
+	if (doRedirect) {
+		_flags |= kIOMemoryRedirected;
+	} else {
+		_flags &= ~kIOMemoryRedirected;
+	}
 
-    if( newMap
-     && !newMap->initWithDescriptor( this, intoTask, mapAddress,
-                    options | kIOMapStatic, 0, getLength() )) {
-	newMap->release();
-	newMap = 0;
-    }
+	do {
+		if ((iter = OSCollectionIterator::withCollection( _mappings))) {
+			memory_object_t   pager;
 
-    addMapping( newMap);
+			if (reserved) {
+				pager = (memory_object_t) reserved->dp.devicePager;
+			} else {
+				pager = MACH_PORT_NULL;
+			}
 
-    UNLOCK;
+			while ((mapping = (IOMemoryMap *) iter->getNextObject())) {
+				mapping->redirect( safeTask, doRedirect );
+				if (!doRedirect && !safeTask && pager && (kernel_map == mapping->fAddressMap)) {
+					err = populateDevicePager(pager, mapping->fAddressMap, mapping->fAddress, mapping->fOffset, mapping->fLength, kIOMapDefaultCache );
+				}
+			}
 
-    return( newMap);
-}
+			iter->release();
+		}
+	} while (false);
 
-IOMemoryMap * IOMemoryDescriptor::map( 
-	IOOptionBits		options )
-{
+	if (!doRedirect) {
+		WAKEUP;
+	}
 
-    return( makeMapping( this, kernel_task, 0,
-			options | kIOMapAnywhere,
-			0, getLength() ));
-}
+	UNLOCK;
 
-IOMemoryMap * IOMemoryDescriptor::map(
-	task_t			intoTask,
-	IOVirtualAddress	toAddress,
-	IOOptionBits		options,
-	IOByteCount		offset,
-	IOByteCount		length )
-{
-    if( 0 == length)
-	length = getLength();
+#ifndef __LP64__
+	// temporary binary compatibility
+	IOSubMemoryDescriptor * subMem;
+	if ((subMem = OSDynamicCast( IOSubMemoryDescriptor, this))) {
+		err = subMem->redirect( safeTask, doRedirect );
+	} else {
+		err = kIOReturnSuccess;
+	}
+#endif /* !__LP64__ */
 
-    return( makeMapping( this, intoTask, toAddress, options, offset, length ));
+	return err;
 }
 
-IOReturn _IOMemoryMap::redirect(IOMemoryDescriptor * newBackingMemory,
-			        IOOptionBits         options,
-			        IOByteCount          offset)
+IOReturn
+IOMemoryMap::redirect( task_t safeTask, bool doRedirect )
 {
-    IOReturn err = kIOReturnSuccess;
-    IOMemoryDescriptor * physMem = 0;
-
-    LOCK;
-
-    if (logical && addressMap) do 
-    {
-	if (((memory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
-	    || ((memory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64))
-	{
-	    physMem = memory;
-	    physMem->retain();
-	}
-
-	if (!redirUPL)
-	{
-	    vm_size_t size = length;
-	    int flags = UPL_COPYOUT_FROM | UPL_SET_INTERNAL 
-			| UPL_SET_LITE | UPL_SET_IO_WIRE | UPL_BLOCK_ACCESS;
-	    if (KERN_SUCCESS != memory_object_iopl_request((ipc_port_t) memory->_memEntry, 0, &size, &redirUPL,
-					    NULL, NULL,
-					    &flags))
-		redirUPL = 0;
-
-	    if (physMem)
-	    {
-		IOUnmapPages( addressMap, logical, length );
-		physMem->redirect(0, true);
-	    }
-	}
-
-	if (newBackingMemory)
-	{
-	    if (newBackingMemory != memory)
-	    {
-		if (this != newBackingMemory->makeMapping(newBackingMemory, addressTask, (IOVirtualAddress) this, 
-							    options | kIOMapUnique | kIOMapReference,
-							    offset, length))
-		    err = kIOReturnError;
-	    }
-	    if (redirUPL)
-	    {
-		upl_commit(redirUPL, NULL, 0);
-		upl_deallocate(redirUPL);
-		redirUPL = 0;
-	    }
-	    if (physMem)
-		physMem->redirect(0, false);
-	}
-    }
-    while (false);
-
-    UNLOCK;
-
-    if (physMem)
-	physMem->release();
-
-    return (err);
-}
-
-IOMemoryMap * IOMemoryDescriptor::makeMapping(
-	IOMemoryDescriptor *	owner,
-	task_t			intoTask,
-	IOVirtualAddress	toAddress,
-	IOOptionBits		options,
-	IOByteCount		offset,
-	IOByteCount		length )
-{
-    IOMemoryDescriptor * mapDesc = 0;
-    _IOMemoryMap *	mapping = 0;
-    OSIterator *	iter;
-
-    LOCK;
-
-    do
-    {
-	if (kIOMapUnique & options)
-	{
-	    IOPhysicalAddress phys;
-	    IOByteCount       physLen;
-
-	    if (owner != this)
-		continue;
-
-	    if (((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
-		|| ((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64))
-	    {
-		phys = getPhysicalSegment(offset, &physLen);
-		if (!phys || (physLen < length))
-		    continue;
-    
-		mapDesc = IOMemoryDescriptor::withPhysicalAddress(
-				phys, length, _direction);
-		if (!mapDesc)
-		    continue;
-		offset = 0;
-	    }
-	    else
-	    {
-		mapDesc = this;
-		mapDesc->retain();
-	    }
-
-	    if (kIOMapReference & options)
-	    {
-		mapping = (_IOMemoryMap *) toAddress;
-		mapping->retain();
-
-#if 1
-		uint32_t pageOffset1 = mapDesc->getSourceSegment( offset, NULL );
-		pageOffset1 -= trunc_page_32( pageOffset1 );
-
-		uint32_t pageOffset2 = mapping->getVirtualAddress();
-		pageOffset2 -= trunc_page_32( pageOffset2 );
-		
-		if (pageOffset1 != pageOffset2)
-		    IOLog("::redirect can't map offset %x to addr %x\n", 
-			    pageOffset1, mapping->getVirtualAddress());
-#endif
-
+	IOReturn err = kIOReturnSuccess;
 
-		if (!mapping->initWithDescriptor( mapDesc, intoTask, toAddress, options,
-						    offset, length ))
-		{
-#ifdef DEBUG
-		    IOLog("Didn't redirect map %08lx : %08lx\n", offset, length );
+	if (fSuperMap) {
+//        err = ((IOMemoryMap *)superMap)->redirect( safeTask, doRedirect );
+	} else {
+		LOCK;
+
+		do{
+			if (!fAddress) {
+				break;
+			}
+			if (!fAddressMap) {
+				break;
+			}
+
+			if ((!safeTask || (get_task_map(safeTask) != fAddressMap))
+			    && (0 == (fOptions & kIOMapStatic))) {
+				IOUnmapPages( fAddressMap, fAddress, fLength );
+				err = kIOReturnSuccess;
+#if DEBUG
+				IOLog("IOMemoryMap::redirect(%d, %p) 0x%qx:0x%qx from %p\n", doRedirect, this, fAddress, fLength, fAddressMap);
 #endif
-		}
+			} else if (kIOMapWriteCombineCache == (fOptions & kIOMapCacheMask)) {
+				IOOptionBits newMode;
+				newMode = (fOptions & ~kIOMapCacheMask) | (doRedirect ? kIOMapInhibitCache : kIOMapWriteCombineCache);
+				IOProtectCacheMode(fAddressMap, fAddress, fLength, newMode);
+			}
+		}while (false);
+		UNLOCK;
+	}
 
-		if (mapping->owner)
-		    mapping->owner->removeMapping(mapping);
-		continue;
-	    }
+	if ((((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
+	    || ((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64))
+	    && safeTask
+	    && (doRedirect != (0 != (fMemory->_flags & kIOMemoryRedirected)))) {
+		fMemory->redirect(safeTask, doRedirect);
 	}
-	else
-	{
-	    // look for an existing mapping
-	    if( (iter = OSCollectionIterator::withCollection( _mappings))) {
-    
-		while( (mapping = (_IOMemoryMap *) iter->getNextObject())) {
-    
-		    if( (mapping = mapping->copyCompatible( 
-					    owner, intoTask, toAddress,
-					    options | kIOMapReference,
-					    offset, length )))
-			break;
-		}
-		iter->release();
-	    }
 
+	return err;
+}
 
-	if (mapping)
-	    mapping->retain();
+IOReturn
+IOMemoryMap::unmap( void )
+{
+	IOReturn    err;
 
-	    if( mapping || (options & kIOMapReference))
-		continue;
+	LOCK;
 
-	    mapDesc = owner;
-	    mapDesc->retain();
+	if (fAddress && fAddressMap && (NULL == fSuperMap) && fMemory
+	    && (0 == (kIOMapStatic & fOptions))) {
+		err = fMemory->doUnmap(fAddressMap, (IOVirtualAddress) this, 0);
+	} else {
+		err = kIOReturnSuccess;
 	}
-	owner = this;
 
-        mapping = new _IOMemoryMap;
-	if( mapping
-	&& !mapping->initWithDescriptor( mapDesc, intoTask, toAddress, options,
-			   offset, length )) {
-#ifdef DEBUG
-	    IOLog("Didn't make map %08lx : %08lx\n", offset, length );
-#endif
-	    mapping->release();
-            mapping = 0;
+	if (fAddressMap) {
+		vm_map_deallocate(fAddressMap);
+		fAddressMap = NULL;
 	}
 
-	if (mapping)
-	    mapping->retain();
-
-    } while( false );
+	fAddress = 0;
 
-    if (mapping)
-    {
-	mapping->owner = owner;
-	owner->addMapping( mapping);
-	mapping->release();
-    }
+	UNLOCK;
 
-    UNLOCK;
+	return err;
+}
 
-    if (mapDesc)
-	mapDesc->release();
+void
+IOMemoryMap::taskDied( void )
+{
+	LOCK;
+	if (fUserClientUnmap) {
+		unmap();
+	}
+#if IOTRACKING
+	else {
+		IOTrackingRemoveUser(gIOMapTracking, &fTracking);
+	}
+#endif /* IOTRACKING */
 
-    return( mapping);
+	if (fAddressMap) {
+		vm_map_deallocate(fAddressMap);
+		fAddressMap = NULL;
+	}
+	fAddressTask = NULL;
+	fAddress     = 0;
+	UNLOCK;
 }
 
-void IOMemoryDescriptor::addMapping(
-	IOMemoryMap * mapping )
+IOReturn
+IOMemoryMap::userClientUnmap( void )
 {
-    if( mapping) {
-        if( 0 == _mappings)
-            _mappings = OSSet::withCapacity(1);
-	if( _mappings )
-	    _mappings->setObject( mapping );
-    }
+	fUserClientUnmap = true;
+	return kIOReturnSuccess;
 }
 
-void IOMemoryDescriptor::removeMapping(
-	IOMemoryMap * mapping )
+// Overload the release mechanism.  All mappings must be a member
+// of a memory descriptors _mappings set.  This means that we
+// always have 2 references on a mapping.  When either of these mappings
+// are released we need to free ourselves.
+void
+IOMemoryMap::taggedRelease(const void *tag) const
 {
-    if( _mappings)
-        _mappings->removeObject( mapping);
+	LOCK;
+	super::taggedRelease(tag, 2);
+	UNLOCK;
 }
 
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+void
+IOMemoryMap::free()
+{
+	unmap();
 
-#undef super
-#define super IOMemoryDescriptor
+	if (fMemory) {
+		LOCK;
+		fMemory->removeMapping(this);
+		UNLOCK;
+		fMemory->release();
+	}
 
-OSDefineMetaClassAndStructors(IOSubMemoryDescriptor, IOMemoryDescriptor)
+	if (fOwner && (fOwner != fMemory)) {
+		LOCK;
+		fOwner->removeMapping(this);
+		UNLOCK;
+	}
 
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+	if (fSuperMap) {
+		fSuperMap->release();
+	}
 
-bool IOSubMemoryDescriptor::initSubRange( IOMemoryDescriptor * parent,
-					IOByteCount offset, IOByteCount length,
-					IODirection direction )
-{
-    if( !parent)
-	return( false);
+	if (fRedirUPL) {
+		upl_commit(fRedirUPL, NULL, 0);
+		upl_deallocate(fRedirUPL);
+	}
 
-    if( (offset + length) > parent->getLength())
-	return( false);
+	super::free();
+}
 
-    /*
-     * We can check the _parent instance variable before having ever set it
-     * to an initial value because I/O Kit guarantees that all our instance
-     * variables are zeroed on an object's allocation.
-     */
+IOByteCount
+IOMemoryMap::getLength()
+{
+	return fLength;
+}
 
-    if( !_parent) {
-	if( !super::init())
-	    return( false );
-    } else {
-	/*
-	 * An existing memory descriptor is being retargeted to
-	 * point to somewhere else.  Clean up our present state.
-	 */
+IOVirtualAddress
+IOMemoryMap::getVirtualAddress()
+{
+#ifndef __LP64__
+	if (fSuperMap) {
+		fSuperMap->getVirtualAddress();
+	} else if (fAddressMap
+	    && vm_map_is_64bit(fAddressMap)
+	    && (sizeof(IOVirtualAddress) < 8)) {
+		OSReportWithBacktrace("IOMemoryMap::getVirtualAddress(0x%qx) called on 64b map; use ::getAddress()", fAddress);
+	}
+#endif /* !__LP64__ */
 
-	_parent->release();
-	_parent = 0;
-    }
+	return fAddress;
+}
 
-    parent->retain();
-    _parent	= parent;
-    _start	= offset;
-    _length	= length;
-    _direction  = direction;
-    _tag	= parent->getTag();
+#ifndef __LP64__
+mach_vm_address_t
+IOMemoryMap::getAddress()
+{
+	return fAddress;
+}
 
-    return( true );
+mach_vm_size_t
+IOMemoryMap::getSize()
+{
+	return fLength;
 }
+#endif /* !__LP64__ */
+
 
-void IOSubMemoryDescriptor::free( void )
+task_t
+IOMemoryMap::getAddressTask()
 {
-    if( _parent)
-	_parent->release();
+	if (fSuperMap) {
+		return fSuperMap->getAddressTask();
+	} else {
+		return fAddressTask;
+	}
+}
 
-    super::free();
+IOOptionBits
+IOMemoryMap::getMapOptions()
+{
+	return fOptions;
 }
 
+IOMemoryDescriptor *
+IOMemoryMap::getMemoryDescriptor()
+{
+	return fMemory;
+}
 
-IOReturn
-IOSubMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
+IOMemoryMap *
+IOMemoryMap::copyCompatible(
+	IOMemoryMap * newMapping )
 {
-    IOReturn rtn;
+	task_t              task      = newMapping->getAddressTask();
+	mach_vm_address_t   toAddress = newMapping->fAddress;
+	IOOptionBits        _options  = newMapping->fOptions;
+	mach_vm_size_t      _offset   = newMapping->fOffset;
+	mach_vm_size_t      _length   = newMapping->fLength;
+
+	if ((!task) || (!fAddressMap) || (fAddressMap != get_task_map(task))) {
+		return NULL;
+	}
+	if ((fOptions ^ _options) & kIOMapReadOnly) {
+		return NULL;
+	}
+	if ((kIOMapDefaultCache != (_options & kIOMapCacheMask))
+	    && ((fOptions ^ _options) & kIOMapCacheMask)) {
+		return NULL;
+	}
 
-    if (kIOMDGetCharacteristics == op) {
+	if ((0 == (_options & kIOMapAnywhere)) && (fAddress != toAddress)) {
+		return NULL;
+	}
 
-	rtn = _parent->dmaCommandOperation(op, vData, dataSize);
-	if (kIOReturnSuccess == rtn) {
-	    IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
-	    data->fLength = _length;
-	    data->fSGCount = 0;	// XXX gvdl: need to compute and pages
-	    data->fPages = 0;
-	    data->fPageAlign = 0;
+	if (_offset < fOffset) {
+		return NULL;
 	}
 
-	return rtn;
-    }
-    else if (kIOMDWalkSegments & op) {
-	if (dataSize < sizeof(IOMDDMAWalkSegmentArgs))
-	    return kIOReturnUnderrun;
+	_offset -= fOffset;
 
-	IOMDDMAWalkSegmentArgs *data =
-	    reinterpret_cast<IOMDDMAWalkSegmentArgs *>(vData);
-	UInt offset = data->fOffset;
-	UInt remain = _length - offset;
-	if ((int) remain <= 0)
-	    return (!remain)? kIOReturnOverrun : kIOReturnInternalError;
+	if ((_offset + _length) > fLength) {
+		return NULL;
+	}
 
-	data->fOffset = offset + _start;
-	rtn = _parent->dmaCommandOperation(op, vData, dataSize);
-	if (data->fLength > remain)
-	    data->fLength = remain;
-	data->fOffset  = offset;
+	retain();
+	if ((fLength == _length) && (!_offset)) {
+		newMapping = this;
+	} else {
+		newMapping->fSuperMap = this;
+		newMapping->fOffset   = fOffset + _offset;
+		newMapping->fAddress  = fAddress + _offset;
+	}
 
-	return rtn;
-    }
-    else
-	return kIOReturnBadArgument;
+	return newMapping;
 }
 
-addr64_t
-IOSubMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount * length)
+IOReturn
+IOMemoryMap::wireRange(
+	uint32_t                options,
+	mach_vm_size_t          offset,
+	mach_vm_size_t          length)
 {
-    addr64_t	address;
-    IOByteCount	actualLength;
-
-    assert(offset <= _length);
-
-    if( length)
-        *length = 0;
+	IOReturn kr;
+	mach_vm_address_t start = trunc_page_64(fAddress + offset);
+	mach_vm_address_t end   = round_page_64(fAddress + offset + length);
+	vm_prot_t prot;
+
+	prot = (kIODirectionOutIn & options);
+	if (prot) {
+		kr = vm_map_wire_kernel(fAddressMap, start, end, prot, fMemory->getVMTag(kernel_map), FALSE);
+	} else {
+		kr = vm_map_unwire(fAddressMap, start, end, FALSE);
+	}
 
-    if( offset >= _length)
-        return( 0 );
+	return kr;
+}
 
-    address = _parent->getPhysicalSegment64( offset + _start, &actualLength );
 
-    if( address && length)
-	*length = min( _length - offset, actualLength );
+IOPhysicalAddress
+#ifdef __LP64__
+IOMemoryMap::getPhysicalSegment( IOByteCount _offset, IOPhysicalLength * _length, IOOptionBits _options)
+#else /* !__LP64__ */
+IOMemoryMap::getPhysicalSegment( IOByteCount _offset, IOPhysicalLength * _length)
+#endif /* !__LP64__ */
+{
+	IOPhysicalAddress   address;
+
+	LOCK;
+#ifdef __LP64__
+	address = fMemory->getPhysicalSegment( fOffset + _offset, _length, _options );
+#else /* !__LP64__ */
+	address = fMemory->getPhysicalSegment( fOffset + _offset, _length );
+#endif /* !__LP64__ */
+	UNLOCK;
 
-    return( address );
+	return address;
 }
 
-IOPhysicalAddress
-IOSubMemoryDescriptor::getPhysicalSegment( IOByteCount offset, IOByteCount * length )
-{
-    IOPhysicalAddress	address;
-    IOByteCount		actualLength;
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-    assert(offset <= _length);
+#undef super
+#define super OSObject
 
-    if( length)
-        *length = 0;
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-    if( offset >= _length)
-        return( 0 );
+void
+IOMemoryDescriptor::initialize( void )
+{
+	if (NULL == gIOMemoryLock) {
+		gIOMemoryLock = IORecursiveLockAlloc();
+	}
 
-    address = _parent->getPhysicalSegment( offset + _start, &actualLength );
+	gIOLastPage = IOGetLastPageNumber();
+}
 
-    if( address && length)
-	*length = min( _length - offset, actualLength );
+void
+IOMemoryDescriptor::free( void )
+{
+	if (_mappings) {
+		_mappings->release();
+	}
 
-    return( address );
+	if (reserved) {
+		cleanKernelReserved(reserved);
+		IODelete(reserved, IOMemoryDescriptorReserved, 1);
+		reserved = NULL;
+	}
+	super::free();
 }
 
+IOMemoryMap *
+IOMemoryDescriptor::setMapping(
+	task_t                  intoTask,
+	IOVirtualAddress        mapAddress,
+	IOOptionBits            options )
+{
+	return createMappingInTask( intoTask, mapAddress,
+	           options | kIOMapStatic,
+	           0, getLength());
+}
 
-IOReturn IOSubMemoryDescriptor::doMap(
-	vm_map_t		addressMap,
-	IOVirtualAddress *	atAddress,
-	IOOptionBits		options,
-	IOByteCount		sourceOffset,
-	IOByteCount		length )
+IOMemoryMap *
+IOMemoryDescriptor::map(
+	IOOptionBits            options )
 {
-    if( sourceOffset >= _length)
-        return( kIOReturnOverrun );
-    return (_parent->doMap(addressMap, atAddress, options, sourceOffset + _start, length));
+	return createMappingInTask( kernel_task, 0,
+	           options | kIOMapAnywhere,
+	           0, getLength());
 }
 
-IOPhysicalAddress 
-IOSubMemoryDescriptor::getSourceSegment( IOByteCount offset, IOByteCount * length )
+#ifndef __LP64__
+IOMemoryMap *
+IOMemoryDescriptor::map(
+	task_t                  intoTask,
+	IOVirtualAddress        atAddress,
+	IOOptionBits            options,
+	IOByteCount             offset,
+	IOByteCount             length )
+{
+	if ((!(kIOMapAnywhere & options)) && vm_map_is_64bit(get_task_map(intoTask))) {
+		OSReportWithBacktrace("IOMemoryDescriptor::map() in 64b task, use ::createMappingInTask()");
+		return NULL;
+	}
+
+	return createMappingInTask(intoTask, atAddress,
+	           options, offset, length);
+}
+#endif /* !__LP64__ */
+
+IOMemoryMap *
+IOMemoryDescriptor::createMappingInTask(
+	task_t                  intoTask,
+	mach_vm_address_t       atAddress,
+	IOOptionBits            options,
+	mach_vm_size_t          offset,
+	mach_vm_size_t          length)
 {
-    IOPhysicalAddress	address;
-    IOByteCount		actualLength;
+	IOMemoryMap * result;
+	IOMemoryMap * mapping;
 
-    assert(offset <= _length);
+	if (0 == length) {
+		length = getLength();
+	}
 
-    if( length)
-        *length = 0;
+	mapping = new IOMemoryMap;
 
-    if( offset >= _length)
-        return( 0 );
+	if (mapping
+	    && !mapping->init( intoTask, atAddress,
+	    options, offset, length )) {
+		mapping->release();
+		mapping = NULL;
+	}
 
-    address = _parent->getSourceSegment( offset + _start, &actualLength );
+	if (mapping) {
+		result = makeMapping(this, intoTask, (IOVirtualAddress) mapping, options | kIOMap64Bit, 0, 0);
+	} else {
+		result = NULL;
+	}
 
-    if( address && length)
-	*length = min( _length - offset, actualLength );
+#if DEBUG
+	if (!result) {
+		IOLog("createMappingInTask failed desc %p, addr %qx, options %x, offset %qx, length %llx\n",
+		    this, atAddress, (uint32_t) options, offset, length);
+	}
+#endif
 
-    return( address );
+	return result;
 }
 
-void * IOSubMemoryDescriptor::getVirtualSegment(IOByteCount offset,
-					IOByteCount * lengthOfSegment)
+#ifndef __LP64__ // there is only a 64 bit version for LP64
+IOReturn
+IOMemoryMap::redirect(IOMemoryDescriptor * newBackingMemory,
+    IOOptionBits         options,
+    IOByteCount          offset)
 {
-    return( 0 );
+	return redirect(newBackingMemory, options, (mach_vm_size_t)offset);
 }
+#endif
 
-IOByteCount IOSubMemoryDescriptor::readBytes(IOByteCount offset,
-					void * bytes, IOByteCount length)
+IOReturn
+IOMemoryMap::redirect(IOMemoryDescriptor * newBackingMemory,
+    IOOptionBits         options,
+    mach_vm_size_t       offset)
 {
-    IOByteCount	byteCount;
-
-    assert(offset <= _length);
+	IOReturn err = kIOReturnSuccess;
+	IOMemoryDescriptor * physMem = NULL;
+
+	LOCK;
+
+	if (fAddress && fAddressMap) {
+		do{
+			if (((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
+			    || ((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64)) {
+				physMem = fMemory;
+				physMem->retain();
+			}
+
+			if (!fRedirUPL && fMemory->_memRef && (1 == fMemory->_memRef->count)) {
+				upl_size_t          size = round_page(fLength);
+				upl_control_flags_t flags = UPL_COPYOUT_FROM | UPL_SET_INTERNAL
+				    | UPL_SET_LITE | UPL_SET_IO_WIRE | UPL_BLOCK_ACCESS;
+				if (KERN_SUCCESS != memory_object_iopl_request(fMemory->_memRef->entries[0].entry, 0, &size, &fRedirUPL,
+				    NULL, NULL,
+				    &flags, fMemory->getVMTag(kernel_map))) {
+					fRedirUPL = NULL;
+				}
+
+				if (physMem) {
+					IOUnmapPages( fAddressMap, fAddress, fLength );
+					if ((false)) {
+						physMem->redirect(NULL, true);
+					}
+				}
+			}
+
+			if (newBackingMemory) {
+				if (newBackingMemory != fMemory) {
+					fOffset = 0;
+					if (this != newBackingMemory->makeMapping(newBackingMemory, fAddressTask, (IOVirtualAddress) this,
+					    options | kIOMapUnique | kIOMapReference | kIOMap64Bit,
+					    offset, fLength)) {
+						err = kIOReturnError;
+					}
+				}
+				if (fRedirUPL) {
+					upl_commit(fRedirUPL, NULL, 0);
+					upl_deallocate(fRedirUPL);
+					fRedirUPL = NULL;
+				}
+				if ((false) && physMem) {
+					physMem->redirect(NULL, false);
+				}
+			}
+		}while (false);
+	}
 
-    if( offset >= _length)
-        return( 0 );
+	UNLOCK;
 
-    LOCK;
-    byteCount = _parent->readBytes( _start + offset, bytes,
-				min(length, _length - offset) );
-    UNLOCK;
+	if (physMem) {
+		physMem->release();
+	}
 
-    return( byteCount );
+	return err;
 }
 
-IOByteCount IOSubMemoryDescriptor::writeBytes(IOByteCount offset,
-				const void* bytes, IOByteCount length)
+IOMemoryMap *
+IOMemoryDescriptor::makeMapping(
+	IOMemoryDescriptor *    owner,
+	task_t                  __intoTask,
+	IOVirtualAddress        __address,
+	IOOptionBits            options,
+	IOByteCount             __offset,
+	IOByteCount             __length )
 {
-    IOByteCount	byteCount;
-
-    assert(offset <= _length);
-
-    if( offset >= _length)
-        return( 0 );
+#ifndef __LP64__
+	if (!(kIOMap64Bit & options)) {
+		panic("IOMemoryDescriptor::makeMapping !64bit");
+	}
+#endif /* !__LP64__ */
 
-    LOCK;
-    byteCount = _parent->writeBytes( _start + offset, bytes,
-				min(length, _length - offset) );
-    UNLOCK;
+	IOMemoryDescriptor *  mapDesc = NULL;
+	__block IOMemoryMap * result  = NULL;
 
-    return( byteCount );
-}
+	IOMemoryMap *  mapping = (IOMemoryMap *) __address;
+	mach_vm_size_t offset  = mapping->fOffset + __offset;
+	mach_vm_size_t length  = mapping->fLength;
 
-IOReturn IOSubMemoryDescriptor::setPurgeable( IOOptionBits newState,
-                                    IOOptionBits * oldState )
-{
-    IOReturn err;
+	mapping->fOffset = offset;
 
-    LOCK;
-    err = _parent->setPurgeable( newState, oldState );
-    UNLOCK;
+	LOCK;
 
-    return( err );
-}
+	do{
+		if (kIOMapStatic & options) {
+			result = mapping;
+			addMapping(mapping);
+			mapping->setMemoryDescriptor(this, 0);
+			continue;
+		}
 
-IOReturn IOSubMemoryDescriptor::performOperation( IOOptionBits options,
-                                        IOByteCount offset, IOByteCount length )
-{
-    IOReturn err;
+		if (kIOMapUnique & options) {
+			addr64_t phys;
+			IOByteCount       physLen;
+
+//	    if (owner != this)		continue;
+
+			if (((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
+			    || ((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64)) {
+				phys = getPhysicalSegment(offset, &physLen, kIOMemoryMapperNone);
+				if (!phys || (physLen < length)) {
+					continue;
+				}
+
+				mapDesc = IOMemoryDescriptor::withAddressRange(
+					phys, length, getDirection() | kIOMemoryMapperNone, NULL);
+				if (!mapDesc) {
+					continue;
+				}
+				offset = 0;
+				mapping->fOffset = offset;
+			}
+		} else {
+			// look for a compatible existing mapping
+			if (_mappings) {
+				_mappings->iterateObjects(^(OSObject * object)
+				{
+					IOMemoryMap * lookMapping = (IOMemoryMap *) object;
+					if ((result = lookMapping->copyCompatible(mapping))) {
+					        addMapping(result);
+					        result->setMemoryDescriptor(this, offset);
+					        return true;
+					}
+					return false;
+				});
+			}
+			if (result || (options & kIOMapReference)) {
+				if (result != mapping) {
+					mapping->release();
+					mapping = NULL;
+				}
+				continue;
+			}
+		}
 
-    assert(offset <= _length);
+		if (!mapDesc) {
+			mapDesc = this;
+			mapDesc->retain();
+		}
+		IOReturn
+		    kr = mapDesc->doMap( NULL, (IOVirtualAddress *) &mapping, options, 0, 0 );
+		if (kIOReturnSuccess == kr) {
+			result = mapping;
+			mapDesc->addMapping(result);
+			result->setMemoryDescriptor(mapDesc, offset);
+		} else {
+			mapping->release();
+			mapping = NULL;
+		}
+	}while (false);
 
-    if( offset >= _length)
-        return( kIOReturnOverrun );
+	UNLOCK;
 
-    LOCK;
-    err = _parent->performOperation( options, _start + offset,
-                                      min(length, _length - offset) );
-    UNLOCK;
+	if (mapDesc) {
+		mapDesc->release();
+	}
 
-    return( err );
+	return result;
 }
 
-IOReturn IOSubMemoryDescriptor::prepare(
-		IODirection forDirection)
+void
+IOMemoryDescriptor::addMapping(
+	IOMemoryMap * mapping )
 {
-    IOReturn	err;
-
-    LOCK;
-    err = _parent->prepare( forDirection);
-    UNLOCK;
-
-    return( err );
+	if (mapping) {
+		if (NULL == _mappings) {
+			_mappings = OSSet::withCapacity(1);
+		}
+		if (_mappings) {
+			_mappings->setObject( mapping );
+		}
+	}
 }
 
-IOReturn IOSubMemoryDescriptor::complete(
-		IODirection forDirection)
+void
+IOMemoryDescriptor::removeMapping(
+	IOMemoryMap * mapping )
 {
-    IOReturn	err;
-
-    LOCK;
-    err = _parent->complete( forDirection);
-    UNLOCK;
-
-    return( err );
+	if (_mappings) {
+		_mappings->removeObject( mapping);
+	}
 }
 
-IOMemoryMap * IOSubMemoryDescriptor::makeMapping(
-	IOMemoryDescriptor *	owner,
-	task_t			intoTask,
-	IOVirtualAddress	toAddress,
-	IOOptionBits		options,
-	IOByteCount		offset,
-	IOByteCount		length )
+#ifndef __LP64__
+// obsolete initializers
+// - initWithOptions is the designated initializer
+bool
+IOMemoryDescriptor::initWithAddress(void *      address,
+    IOByteCount   length,
+    IODirection direction)
 {
-    IOMemoryMap * mapping = 0;
-
-    if (!(kIOMapUnique & options))
-	mapping = (IOMemoryMap *) _parent->makeMapping(
-					_parent, intoTask,
-					toAddress - (_start + offset),
-					options | kIOMapReference,
-					_start + offset, length );
-
-    if( !mapping)
-        mapping = (IOMemoryMap *) _parent->makeMapping(
-					_parent, intoTask,
-					toAddress,
-					options, _start + offset, length );
-
-    if( !mapping)
-	mapping = super::makeMapping( owner, intoTask, toAddress, options,
-					offset, length );
-
-    return( mapping );
+	return false;
 }
 
-/* ick */
-
 bool
-IOSubMemoryDescriptor::initWithAddress(void *      address,
-                                    IOByteCount   length,
-                                    IODirection direction)
+IOMemoryDescriptor::initWithAddress(IOVirtualAddress address,
+    IOByteCount    length,
+    IODirection  direction,
+    task_t       task)
 {
-    return( false );
+	return false;
 }
 
 bool
-IOSubMemoryDescriptor::initWithAddress(vm_address_t address,
-                                    IOByteCount    length,
-                                    IODirection  direction,
-                                    task_t       task)
+IOMemoryDescriptor::initWithPhysicalAddress(
+	IOPhysicalAddress      address,
+	IOByteCount            length,
+	IODirection            direction )
 {
-    return( false );
+	return false;
 }
 
 bool
-IOSubMemoryDescriptor::initWithPhysicalAddress(
-				 IOPhysicalAddress	address,
-				 IOByteCount		length,
-				 IODirection      	direction )
+IOMemoryDescriptor::initWithRanges(
+	IOVirtualRange * ranges,
+	UInt32           withCount,
+	IODirection      direction,
+	task_t           task,
+	bool             asReference)
 {
-    return( false );
+	return false;
 }
 
 bool
-IOSubMemoryDescriptor::initWithRanges(
-                                   	IOVirtualRange * ranges,
-                                   	UInt32           withCount,
-                                   	IODirection      direction,
-                                   	task_t           task,
-                                  	bool             asReference)
+IOMemoryDescriptor::initWithPhysicalRanges(     IOPhysicalRange * ranges,
+    UInt32           withCount,
+    IODirection      direction,
+    bool             asReference)
 {
-    return( false );
+	return false;
 }
 
-bool
-IOSubMemoryDescriptor::initWithPhysicalRanges(	IOPhysicalRange * ranges,
-                                        	UInt32           withCount,
-                                        	IODirection      direction,
-                                        	bool             asReference)
+void *
+IOMemoryDescriptor::getVirtualSegment(IOByteCount offset,
+    IOByteCount * lengthOfSegment)
 {
-    return( false );
+	return NULL;
 }
+#endif /* !__LP64__ */
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-bool IOGeneralMemoryDescriptor::serialize(OSSerialize * s) const
+bool
+IOGeneralMemoryDescriptor::serialize(OSSerialize * s) const
 {
-    OSSymbol const *keys[2];
-    OSObject *values[2];
-    struct SerData {
-	user_addr_t address;
-	user_size_t length;
-    } *vcopy;
-    unsigned int index, nRanges;
-    bool result;
-
-    IOOptionBits type = _flags & kIOMemoryTypeMask;
-
-    if (s == NULL) return false;
-    if (s->previouslySerialized(this)) return true;
-
-    // Pretend we are an array.
-    if (!s->addXMLStartTag(this, "array")) return false;
+	OSSymbol const *keys[2] = {NULL};
+	OSObject *values[2] = {NULL};
+	OSArray * array;
+	vm_size_t vcopy_size;
+
+	struct SerData {
+		user_addr_t address;
+		user_size_t length;
+	} *vcopy = NULL;
+	unsigned int index, nRanges;
+	bool result = false;
 
-    nRanges = _rangesCount;
-    vcopy = (SerData *) IOMalloc(sizeof(SerData) * nRanges);
-    if (vcopy == 0) return false;
-
-    keys[0] = OSSymbol::withCString("address");
-    keys[1] = OSSymbol::withCString("length");
-
-    result = false;
-    values[0] = values[1] = 0;
+	IOOptionBits type = _flags & kIOMemoryTypeMask;
 
-    // From this point on we can go to bail.
+	if (s == NULL) {
+		return false;
+	}
 
-    // Copy the volatile data so we don't have to allocate memory
-    // while the lock is held.
-    LOCK;
-    if (nRanges == _rangesCount) {
-	Ranges vec = _ranges;
-        for (index = 0; index < nRanges; index++) {
-	    user_addr_t addr; IOByteCount len;
-	    getAddrLenForInd(addr, len, type, vec, index);
-            vcopy[index].address = addr;
-            vcopy[index].length  = len;
-        }
-    } else {
-	// The descriptor changed out from under us.  Give up.
-        UNLOCK;
-	result = false;
-        goto bail;
-    }
-    UNLOCK;
-
-    for (index = 0; index < nRanges; index++)
-    {
-	user_addr_t addr = vcopy[index].address;
-	IOByteCount len = (IOByteCount) vcopy[index].length;
-	values[0] =
-	    OSNumber::withNumber(addr, (((UInt64) addr) >> 32)? 64 : 32);
-	if (values[0] == 0) {
-	  result = false;
-	  goto bail;
-	}
-	values[1] = OSNumber::withNumber(len, sizeof(len) * 8);
-	if (values[1] == 0) {
-	  result = false;
-	  goto bail;
-	}
-        OSDictionary *dict = OSDictionary::withObjects((const OSObject **)values, (const OSSymbol **)keys, 2);
-	if (dict == 0) {
-	  result = false;
-	  goto bail;
-	}
-	values[0]->release();
-	values[1]->release();
-	values[0] = values[1] = 0;
-
-	result = dict->serialize(s);
-	dict->release();
-	if (!result) {
-	  goto bail;
+	array = OSArray::withCapacity(4);
+	if (!array) {
+		return false;
 	}
-    }
-    result = s->addXMLEndTag("array");
 
- bail:
-    if (values[0])
-      values[0]->release();
-    if (values[1])
-      values[1]->release();
-    if (keys[0])
-      keys[0]->release();
-    if (keys[1])
-      keys[1]->release();
-    if (vcopy)
-        IOFree(vcopy, sizeof(IOVirtualRange) * nRanges);
-    return result;
-}
+	nRanges = _rangesCount;
+	if (os_mul_overflow(sizeof(SerData), nRanges, &vcopy_size)) {
+		result = false;
+		goto bail;
+	}
+	vcopy = (SerData *) IOMalloc(vcopy_size);
+	if (vcopy == NULL) {
+		result = false;
+		goto bail;
+	}
 
-bool IOSubMemoryDescriptor::serialize(OSSerialize * s) const
-{
-    if (!s) {
-	return (false);
-    }
-    if (s->previouslySerialized(this)) return true;
+	keys[0] = OSSymbol::withCString("address");
+	keys[1] = OSSymbol::withCString("length");
+
+	// Copy the volatile data so we don't have to allocate memory
+	// while the lock is held.
+	LOCK;
+	if (nRanges == _rangesCount) {
+		Ranges vec = _ranges;
+		for (index = 0; index < nRanges; index++) {
+			mach_vm_address_t addr; mach_vm_size_t len;
+			getAddrLenForInd(addr, len, type, vec, index);
+			vcopy[index].address = addr;
+			vcopy[index].length  = len;
+		}
+	} else {
+		// The descriptor changed out from under us.  Give up.
+		UNLOCK;
+		result = false;
+		goto bail;
+	}
+	UNLOCK;
 
-    // Pretend we are a dictionary.
-    // We must duplicate the functionality of OSDictionary here
-    // because otherwise object references will not work;
-    // they are based on the value of the object passed to
-    // previouslySerialized and addXMLStartTag.
+	for (index = 0; index < nRanges; index++) {
+		user_addr_t addr = vcopy[index].address;
+		IOByteCount len = (IOByteCount) vcopy[index].length;
+		values[0] = OSNumber::withNumber(addr, sizeof(addr) * 8);
+		if (values[0] == NULL) {
+			result = false;
+			goto bail;
+		}
+		values[1] = OSNumber::withNumber(len, sizeof(len) * 8);
+		if (values[1] == NULL) {
+			result = false;
+			goto bail;
+		}
+		OSDictionary *dict = OSDictionary::withObjects((const OSObject **)values, (const OSSymbol **)keys, 2);
+		if (dict == NULL) {
+			result = false;
+			goto bail;
+		}
+		array->setObject(dict);
+		dict->release();
+		values[0]->release();
+		values[1]->release();
+		values[0] = values[1] = NULL;
+	}
 
-    if (!s->addXMLStartTag(this, "dict")) return false;
+	result = array->serialize(s);
 
-    char const *keys[3] = {"offset", "length", "parent"};
+bail:
+	if (array) {
+		array->release();
+	}
+	if (values[0]) {
+		values[0]->release();
+	}
+	if (values[1]) {
+		values[1]->release();
+	}
+	if (keys[0]) {
+		keys[0]->release();
+	}
+	if (keys[1]) {
+		keys[1]->release();
+	}
+	if (vcopy) {
+		IOFree(vcopy, vcopy_size);
+	}
 
-    OSObject *values[3];
-    values[0] = OSNumber::withNumber(_start, sizeof(_start) * 8);
-    if (values[0] == 0)
-	return false;
-    values[1] = OSNumber::withNumber(_length, sizeof(_length) * 8);
-    if (values[1] == 0) {
-	values[0]->release();
-	return false;
-    }
-    values[2] = _parent;
-
-    bool result = true;
-    for (int i=0; i<3; i++) {
-        if (!s->addString("<key>") ||
-	    !s->addString(keys[i]) ||
-	    !s->addXMLEndTag("key") ||
-	    !values[i]->serialize(s)) {
-	  result = false;
-	  break;
-        }
-    }
-    values[0]->release();
-    values[1]->release();
-    if (!result) {
-      return false;
-    }
-
-    return s->addXMLEndTag("dict");
+	return result;
 }
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 0);
+#ifdef __LP64__
+OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 1);
+OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 2);
+OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 3);
+OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 4);
+OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 5);
+OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 6);
+OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 7);
+#else /* !__LP64__ */
 OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 1);
 OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 2);
 OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 3);
 OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 4);
 OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 5);
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 6);
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 7);
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 6);
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 7);
+#endif /* !__LP64__ */
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 8);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 9);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 10);
@@ -3748,9 +5157,8 @@ OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 14);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 15);
 
 /* ex-inline function implementation */
-IOPhysicalAddress 
+IOPhysicalAddress
 IOMemoryDescriptor::getPhysicalAddress()
-        { return( getPhysicalSegment( 0, 0 )); }
-
-
-
+{
+	return getPhysicalSegment( 0, NULL );
+}