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 #include <DriverKit/IOBufferMemoryDescriptor.h>
  33
  34 enum {
  35         kIOMemoryPhysicallyContiguous       = 0x00000010,
  36         kIOMemoryPageable                   = 0x00000020,
  37         kIOMemoryPurgeable                  = 0x00000040,
  38         kIOMemoryHostPhysicallyContiguous   = 0x00000080,
  39         kIOMemorySharingTypeMask            = 0x000f0000,
  40         kIOMemoryUnshared                   = 0x00000000,
  41         kIOMemoryKernelUserShared           = 0x00010000,
  42         // shared IOMemoryDescriptor options for IOBufferMemoryDescriptor:
  43         kIOBufferDescriptorMemoryFlags      = kIOMemoryDirectionMask
  44 #ifdef XNU_KERNEL_PRIVATE
  45             | kIOMemoryAutoPrepare
  46 #endif
  47             | kIOMemoryThreadSafe
  48             | kIOMemoryClearEncrypt
  49             | kIOMemoryMapperNone
  50             | kIOMemoryUseReserve
  51 };
  52
  53 #define _IOBUFFERMEMORYDESCRIPTOR_INTASKWITHOPTIONS_            1
  54 #define _IOBUFFERMEMORYDESCRIPTOR_HOSTPHYSICALLYCONTIGUOUS_     1
  55 /*!
  56  *   @class IOBufferMemoryDescriptor
  57  *   @abstract Provides a simple memory descriptor that allocates its own buffer memory.
  58  */
  59
  60 class IOBufferMemoryDescriptor : public IOGeneralMemoryDescriptor
  61 {
  62         OSDeclareDefaultStructorsWithDispatch(IOBufferMemoryDescriptor);
  63
  64 private:
  65 /*! @struct ExpansionData
  66  *   @discussion This structure will be used to expand the capablilties of this class in the future.
  67  */
  68         struct ExpansionData {
  69                 IOMemoryMap *   map;
  70         };
  71
  72 /*! @var reserved
  73  *   Reserved for future use.  (Internal use only)  */
  74         APPLE_KEXT_WSHADOW_PUSH;
  75         ExpansionData * reserved;
  76
  77 protected:
  78         void *               _buffer;
  79         vm_size_t            _capacity;
  80         vm_offset_t          _alignment;
  81         IOOptionBits         _options;
  82 private:
  83         uintptr_t            _internalReserved;
  84         unsigned             _internalFlags;
  85         APPLE_KEXT_WSHADOW_POP;
  86
  87 private:
  88 #ifndef __LP64__
  89         virtual bool initWithOptions(
  90                 IOOptionBits options,
  91                 vm_size_t    capacity,
  92                 vm_offset_t  alignment,
  93                 task_t       inTask) APPLE_KEXT_DEPRECATED;                /* use withOptions() instead */
  94 #endif /* !__LP64__ */
  95
  96 public:
  97         virtual bool initWithPhysicalMask(
  98                 task_t            inTask,
  99                 IOOptionBits      options,
 100                 mach_vm_size_t    capacity,
 101                 mach_vm_address_t alignment,
 102                 mach_vm_address_t physicalMask);
 103
 104 #ifdef __LP64__
 105         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 0);
 106         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 1);
 107 #else /* !__LP64__ */
 108         OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 0);
 109         OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 1);
 110 #endif /* !__LP64__ */
 111         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
 112         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
 113         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 4);
 114         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 5);
 115         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 6);
 116         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 7);
 117         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 8);
 118         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 9);
 119         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 10);
 120         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 11);
 121         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 12);
 122         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 13);
 123         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 14);
 124         OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 15);
 125
 126 protected:
 127         virtual void free() APPLE_KEXT_OVERRIDE;
 128
 129 public:
 130
 131 /*
 132  * withOptions:
 133  *
 134  * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 135  * hold capacity bytes.  The descriptor's length is initially set to the
 136  * capacity.
 137  */
 138 #ifndef __LP64__
 139         virtual bool initWithOptions(   IOOptionBits options,
 140             vm_size_t    capacity,
 141             vm_offset_t  alignment) APPLE_KEXT_DEPRECATED;                         /* use withOptions() instead */
 142 #endif /* !__LP64__ */
 143
 144         static IOBufferMemoryDescriptor * withCopy(
 145                 task_t            inTask,
 146                 IOOptionBits      options,
 147                 vm_map_t          sourceMap,
 148                 mach_vm_address_t source,
 149                 mach_vm_size_t    size);
 150
 151         static IOBufferMemoryDescriptor * withOptions(  IOOptionBits options,
 152             vm_size_t    capacity,
 153             vm_offset_t  alignment = 1);
 154
 155 /*! @function inTaskWithOptions
 156  *   @abstract Creates a memory buffer with memory descriptor for that buffer.
 157  *   @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.
 158  *   @param inTask The task the buffer will be allocated in.
 159  *   @param options Options for the allocation:<br>
 160  *   kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 161  *   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>
 162  *   kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
 163  *   kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
 164  *   kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.<br>
 165  *   kIOMapInhibitCache - allocate memory with inhibited cache setting. <br>
 166  *   kIOMapWriteThruCache - allocate memory with writethru cache setting. <br>
 167  *   kIOMapCopybackCache - allocate memory with copyback cache setting. <br>
 168  *   kIOMapWriteCombineCache - allocate memory with writecombined cache setting.
 169  *   @param capacity The number of bytes to allocate.
 170  *   @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.
 171  *   @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 172
 173         static IOBufferMemoryDescriptor * inTaskWithOptions(
 174                 task_t       inTask,
 175                 IOOptionBits options,
 176                 vm_size_t    capacity,
 177                 vm_offset_t  alignment = 1);
 178
 179 /*! @function inTaskWithPhysicalMask
 180  *   @abstract Creates a memory buffer with memory descriptor for that buffer.
 181  *   @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.
 182  *   @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).
 183  *   @param options Options for the allocation:<br>
 184  *   kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 185  *   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>
 186  *   kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.<br>
 187  *   kIOMapInhibitCache - allocate memory with inhibited cache setting. <br>
 188  *   kIOMapWriteThruCache - allocate memory with writethru cache setting. <br>
 189  *   kIOMapCopybackCache - allocate memory with copyback cache setting. <br>
 190  *   kIOMapWriteCombineCache - allocate memory with writecombined cache setting.
 191  *   @param capacity The number of bytes to allocate.
 192  *   @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.
 193  *   @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 194
 195         static IOBufferMemoryDescriptor * inTaskWithPhysicalMask(
 196                 task_t            inTask,
 197                 IOOptionBits      options,
 198                 mach_vm_size_t    capacity,
 199                 mach_vm_address_t physicalMask);
 200
 201 /*
 202  * withCapacity:
 203  *
 204  * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 205  * hold capacity bytes.  The descriptor's length is initially set to the
 206  * capacity.
 207  */
 208         static IOBufferMemoryDescriptor * withCapacity(
 209                 vm_size_t    capacity,
 210                 IODirection  withDirection,
 211                 bool         withContiguousMemory = false);
 212 #ifndef __LP64__
 213         virtual bool initWithBytes(const void * bytes,
 214             vm_size_t    withLength,
 215             IODirection  withDirection,
 216             bool         withContiguousMemory = false) APPLE_KEXT_DEPRECATED;                    /* use withBytes() instead */
 217 #endif /* !__LP64__ */
 218
 219 /*
 220  * withBytes:
 221  *
 222  * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 223  * The descriptor's length and capacity are set to the input buffer's size.
 224  */
 225         static IOBufferMemoryDescriptor * withBytes(
 226                 const void * bytes,
 227                 vm_size_t    withLength,
 228                 IODirection  withDirection,
 229                 bool         withContiguousMemory = false);
 230
 231 /*
 232  * setLength:
 233  *
 234  * Change the buffer length of the memory descriptor.  When a new buffer
 235  * is created, the initial length of the buffer is set to be the same as
 236  * the capacity.  The length can be adjusted via setLength for a shorter
 237  * transfer (there is no need to create more buffer descriptors when you
 238  * can reuse an existing one, even for different transfer sizes).   Note
 239  * that the specified length must not exceed the capacity of the buffer.
 240  */
 241         virtual void setLength(vm_size_t length);
 242
 243 /*
 244  * setDirection:
 245  *
 246  * Change the direction of the transfer.  This method allows one to redirect
 247  * the descriptor's transfer direction.  This eliminates the need to destroy
 248  * and create new buffers when different transfer directions are needed.
 249  */
 250         virtual void setDirection(IODirection direction);
 251
 252 /*
 253  * getCapacity:
 254  *
 255  * Get the buffer capacity
 256  */
 257         virtual vm_size_t getCapacity() const;
 258
 259 /*
 260  * getBytesNoCopy:
 261  *
 262  * Return the virtual address of the beginning of the buffer
 263  */
 264         virtual void *getBytesNoCopy();
 265
 266 /*
 267  * getBytesNoCopy:
 268  *
 269  * Return the virtual address of an offset from the beginning of the buffer
 270  */
 271         virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
 272
 273 /*
 274  * appendBytes:
 275  *
 276  * Add some data to the end of the buffer.  This method automatically
 277  * maintains the memory descriptor buffer length.  Note that appendBytes
 278  * will not copy past the end of the memory descriptor's current capacity.
 279  */
 280         virtual bool appendBytes(const void *bytes, vm_size_t withLength);
 281
 282 #ifndef __LP64__
 283         virtual void * getVirtualSegment(IOByteCount offset,
 284             IOByteCount * length) APPLE_KEXT_OVERRIDE APPLE_KEXT_DEPRECATED;                             /* use getBytesNoCopy() instead */
 285 #endif /* !__LP64__ */
 286 };
 287
 288 #endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */