iokit/IOKit/IOBufferMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 #ifndef _IOBUFFERMEMORYDESCRIPTOR_H
  29 #define _IOBUFFERMEMORYDESCRIPTOR_H
  30
  31 #include <IOKit/IOMemoryDescriptor.h>
  32
  33 enum {
  34         kIOMemoryPhysicallyContiguous       = 0x00000010,
  35         kIOMemoryPageable                   = 0x00000020,
  36         kIOMemoryPurgeable                  = 0x00000040,
  37         kIOMemoryHostPhysicallyContiguous   = 0x00000080,
  38         kIOMemorySharingTypeMask            = 0x000f0000,
  39         kIOMemoryUnshared                   = 0x00000000,
  40         kIOMemoryKernelUserShared           = 0x00010000,
  41         // shared IOMemoryDescriptor options for IOBufferMemoryDescriptor:
  42         kIOBufferDescriptorMemoryFlags      = kIOMemoryDirectionMask
  43 #ifdef XNU_KERNEL_PRIVATE
  44             | kIOMemoryAutoPrepare
  45 #endif
  46             | kIOMemoryThreadSafe
  47             | kIOMemoryClearEncrypt
  48             | kIOMemoryMapperNone
  49             | kIOMemoryUseReserve
  50 };
  51
  52 #define _IOBUFFERMEMORYDESCRIPTOR_INTASKWITHOPTIONS_            1
  53 #define _IOBUFFERMEMORYDESCRIPTOR_HOSTPHYSICALLYCONTIGUOUS_     1
  54 /*!
  55  *   @class IOBufferMemoryDescriptor
  56  *   @abstract Provides a simple memory descriptor that allocates its own buffer memory.
  57  */
  58
  59 class IOBufferMemoryDescriptor : public IOGeneralMemoryDescriptor
  60 {
  61         OSDeclareDefaultStructors(IOBufferMemoryDescriptor);
  62
  63 private:
  64 /*! @struct ExpansionData
  65  *   @discussion This structure will be used to expand the capablilties of this class in the future.
  66  */
  67         struct ExpansionData {
  68                 IOMemoryMap *   map;
  69         };
  70
  71 /*! @var reserved
  72  *   Reserved for future use.  (Internal use only)  */
  73         APPLE_KEXT_WSHADOW_PUSH;
  74         ExpansionData * reserved;
  75
  76 protected:
  77         void *               _buffer;
  78         vm_size_t            _capacity;
  79         vm_offset_t          _alignment;
  80         IOOptionBits         _options;
  81 private:
  82         uintptr_t            _internalReserved;
  83         unsigned             _internalFlags;
  84         APPLE_KEXT_WSHADOW_POP;
  85
  86 private:
  87 #ifndef __LP64__
  88         virtual bool initWithOptions(
  89                 IOOptionBits options,
  90                 vm_size_t    capacity,
  91                 vm_offset_t  alignment,
  92                 task_t       inTask) APPLE_KEXT_DEPRECATED;                /* use withOptions() instead */
  93 #endif /* !__LP64__ */
  94
  95 public:
  96         virtual bool initWithPhysicalMask(
  97                 task_t            inTask,
  98                 IOOptionBits      options,
  99                 mach_vm_size_t    capacity,
 100                 mach_vm_address_t alignment,
 101                 mach_vm_address_t physicalMask);
 102
 103 #ifdef __LP64__
 104         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 0);
 105         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 1);
 106 #else /* !__LP64__ */
 107         OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 0);
 108         OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 1);
 109 #endif /* !__LP64__ */
 110         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
 111         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
 112         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 4);
 113         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 5);
 114         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 6);
 115         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 7);
 116         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 8);
 117         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 9);
 118         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 10);
 119         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 11);
 120         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 12);
 121         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 13);
 122         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 14);
 123         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 15);
 124
 125 protected:
 126         virtual void free() APPLE_KEXT_OVERRIDE;
 127
 128 public:
 129
 130 /*
 131  * withOptions:
 132  *
 133  * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 134  * hold capacity bytes.  The descriptor's length is initially set to the
 135  * capacity.
 136  */
 137 #ifndef __LP64__
 138         virtual bool initWithOptions(   IOOptionBits options,
 139             vm_size_t    capacity,
 140             vm_offset_t  alignment) APPLE_KEXT_DEPRECATED;                         /* use withOptions() instead */
 141 #endif /* !__LP64__ */
 142
 143         static IOBufferMemoryDescriptor * withOptions(  IOOptionBits options,
 144             vm_size_t    capacity,
 145             vm_offset_t  alignment = 1);
 146
 147 /*! @function inTaskWithOptions
 148  *   @abstract Creates a memory buffer with memory descriptor for that buffer.
 149  *   @discussion Added in Mac OS X 10.2, this method allocates a memory buffer with a given size and alignment in the task's address space specified, and returns a memory descriptor instance representing the memory. It is recommended that memory allocated for I/O or sharing via mapping be created via IOBufferMemoryDescriptor. Options passed with the request specify the kind of memory to be allocated - pageablity and sharing are specified with option bits. This function may block and so should not be called from interrupt level or while a simple lock is held.
 150  *   @param inTask The task the buffer will be allocated in.
 151  *   @param options Options for the allocation:<br>
 152  *   kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 153  *   kIOMemoryPhysicallyContiguous - pass to request memory be physically contiguous. This option is heavily discouraged. The request may fail if memory is fragmented, may cause large amounts of paging activity, and may take a very long time to execute.<br>
 154  *   kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
 155  *   kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
 156  *   kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.<br>
 157  *   kIOMapInhibitCache - allocate memory with inhibited cache setting. <br>
 158  *   kIOMapWriteThruCache - allocate memory with writethru cache setting. <br>
 159  *   kIOMapCopybackCache - allocate memory with copyback cache setting. <br>
 160  *   kIOMapWriteCombineCache - allocate memory with writecombined cache setting.
 161  *   @param capacity The number of bytes to allocate.
 162  *   @param alignment The minimum required alignment of the buffer in bytes - 1 is the default for no required alignment. For example, pass 256 to get memory allocated at an address with bits 0-7 zero.
 163  *   @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 164
 165         static IOBufferMemoryDescriptor * inTaskWithOptions(
 166                 task_t       inTask,
 167                 IOOptionBits options,
 168                 vm_size_t    capacity,
 169                 vm_offset_t  alignment = 1);
 170
 171 /*! @function inTaskWithPhysicalMask
 172  *   @abstract Creates a memory buffer with memory descriptor for that buffer.
 173  *   @discussion Added in Mac OS X 10.5, this method allocates a memory buffer with a given size and alignment in the task's address space specified, and returns a memory descriptor instance representing the memory. It is recommended that memory allocated for I/O or sharing via mapping be created via IOBufferMemoryDescriptor. Options passed with the request specify the kind of memory to be allocated - pageablity and sharing are specified with option bits. This function may block and so should not be called from interrupt level or while a simple lock is held.
 174  *   @param inTask The task the buffer will be mapped in. Pass NULL to create memory unmapped in any task (eg. for use as a DMA buffer).
 175  *   @param options Options for the allocation:<br>
 176  *   kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 177  *   kIOMemoryPhysicallyContiguous - pass to request memory be physically contiguous. This option is heavily discouraged. The request may fail if memory is fragmented, may cause large amounts of paging activity, and may take a very long time to execute.<br>
 178  *   kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.<br>
 179  *   kIOMapInhibitCache - allocate memory with inhibited cache setting. <br>
 180  *   kIOMapWriteThruCache - allocate memory with writethru cache setting. <br>
 181  *   kIOMapCopybackCache - allocate memory with copyback cache setting. <br>
 182  *   kIOMapWriteCombineCache - allocate memory with writecombined cache setting.
 183  *   @param capacity The number of bytes to allocate.
 184  *   @param physicalMask The buffer will be allocated with pages such that physical addresses will only have bits set present in physicalMask. For example, pass 0x00000000FFFFFFFFULL for a buffer to be accessed by hardware that has 32 address bits.
 185  *   @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 186
 187         static IOBufferMemoryDescriptor * inTaskWithPhysicalMask(
 188                 task_t            inTask,
 189                 IOOptionBits      options,
 190                 mach_vm_size_t    capacity,
 191                 mach_vm_address_t physicalMask);
 192
 193 /*
 194  * withCapacity:
 195  *
 196  * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 197  * hold capacity bytes.  The descriptor's length is initially set to the
 198  * capacity.
 199  */
 200         static IOBufferMemoryDescriptor * withCapacity(
 201                 vm_size_t    capacity,
 202                 IODirection  withDirection,
 203                 bool         withContiguousMemory = false);
 204 #ifndef __LP64__
 205         virtual bool initWithBytes(const void * bytes,
 206             vm_size_t    withLength,
 207             IODirection  withDirection,
 208             bool         withContiguousMemory = false) APPLE_KEXT_DEPRECATED;                    /* use withBytes() instead */
 209 #endif /* !__LP64__ */
 210
 211 /*
 212  * withBytes:
 213  *
 214  * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 215  * The descriptor's length and capacity are set to the input buffer's size.
 216  */
 217         static IOBufferMemoryDescriptor * withBytes(
 218                 const void * bytes,
 219                 vm_size_t    withLength,
 220                 IODirection  withDirection,
 221                 bool         withContiguousMemory = false);
 222
 223 /*
 224  * setLength:
 225  *
 226  * Change the buffer length of the memory descriptor.  When a new buffer
 227  * is created, the initial length of the buffer is set to be the same as
 228  * the capacity.  The length can be adjusted via setLength for a shorter
 229  * transfer (there is no need to create more buffer descriptors when you
 230  * can reuse an existing one, even for different transfer sizes).   Note
 231  * that the specified length must not exceed the capacity of the buffer.
 232  */
 233         virtual void setLength(vm_size_t length);
 234
 235 /*
 236  * setDirection:
 237  *
 238  * Change the direction of the transfer.  This method allows one to redirect
 239  * the descriptor's transfer direction.  This eliminates the need to destroy
 240  * and create new buffers when different transfer directions are needed.
 241  */
 242         virtual void setDirection(IODirection direction);
 243
 244 /*
 245  * getCapacity:
 246  *
 247  * Get the buffer capacity
 248  */
 249         virtual vm_size_t getCapacity() const;
 250
 251 /*
 252  * getBytesNoCopy:
 253  *
 254  * Return the virtual address of the beginning of the buffer
 255  */
 256         virtual void *getBytesNoCopy();
 257
 258 /*
 259  * getBytesNoCopy:
 260  *
 261  * Return the virtual address of an offset from the beginning of the buffer
 262  */
 263         virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
 264
 265 /*
 266  * appendBytes:
 267  *
 268  * Add some data to the end of the buffer.  This method automatically
 269  * maintains the memory descriptor buffer length.  Note that appendBytes
 270  * will not copy past the end of the memory descriptor's current capacity.
 271  */
 272         virtual bool appendBytes(const void *bytes, vm_size_t withLength);
 273
 274 #ifndef __LP64__
 275         virtual void * getVirtualSegment(IOByteCount offset,
 276             IOByteCount * length) APPLE_KEXT_OVERRIDE APPLE_KEXT_DEPRECATED;                             /* use getBytesNoCopy() instead */
 277 #endif /* !__LP64__ */
 278 };
 279
 280 #endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */