iokit/IOKit/IOBufferMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, 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,
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  23  * Please see the License for the specific language governing rights and
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  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     kIOMemorySharingTypeMask            = 0x000f0000,
  38     kIOMemoryUnshared                   = 0x00000000,
  39     kIOMemoryKernelUserShared           = 0x00010000,
  40     // shared IOMemoryDescriptor options for IOBufferMemoryDescriptor:
  41     kIOBufferDescriptorMemoryFlags      = kIOMemoryDirectionMask
  42 #ifdef XNU_KERNEL_PRIVATE
  43                                         | kIOMemoryAutoPrepare
  44 #endif
  45                                         | kIOMemoryThreadSafe
  46 };
  47
  48 #define _IOBUFFERMEMORYDESCRIPTOR_INTASKWITHOPTIONS_    1
  49 /*!
  50     @class IOBufferMemoryDescriptor
  51     @abstract Provides a simple memory descriptor that allocates its own buffer memory.
  52 */
  53
  54 class IOBufferMemoryDescriptor : public IOGeneralMemoryDescriptor
  55 {
  56     OSDeclareDefaultStructors(IOBufferMemoryDescriptor);
  57
  58 private:
  59 /*! @struct ExpansionData
  60     @discussion This structure will be used to expand the capablilties of this class in the future.
  61     */
  62     struct ExpansionData {
  63         IOMemoryMap *   map;
  64     };
  65
  66 /*! @var reserved
  67     Reserved for future use.  (Internal use only)  */
  68     ExpansionData * reserved;
  69
  70 protected:
  71     void *               _buffer;
  72     vm_size_t            _capacity;
  73     vm_offset_t          _alignment;
  74     IOOptionBits         _options;
  75 private:
  76     uintptr_t            _internalReserved;
  77     unsigned             _internalFlags;
  78
  79 private:
  80 #ifndef __LP64__
  81     virtual bool initWithOptions(
  82                                IOOptionBits options,
  83                                vm_size_t    capacity,
  84                                vm_offset_t  alignment,
  85                                task_t       inTask) APPLE_KEXT_DEPRECATED; /* use withOptions() instead */
  86 #endif /* !__LP64__ */
  87
  88     virtual bool initWithPhysicalMask(
  89                                 task_t            inTask,
  90                                 IOOptionBits      options,
  91                                 mach_vm_size_t    capacity,
  92                                 mach_vm_address_t alignment,
  93                                 mach_vm_address_t physicalMask);
  94
  95 #ifdef __LP64__
  96     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 0);
  97     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 1);
  98 #else /* !__LP64__ */
  99     OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 0);
 100     OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 1);
 101 #endif /* !__LP64__ */
 102     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
 103     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
 104     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 4);
 105     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 5);
 106     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 6);
 107     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 7);
 108     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 8);
 109     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 9);
 110     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 10);
 111     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 11);
 112     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 12);
 113     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 13);
 114     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 14);
 115     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 15);
 116
 117 protected:
 118     virtual void free();
 119
 120 public:
 121
 122     /*
 123      * withOptions:
 124      *
 125      * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 126      * hold capacity bytes.  The descriptor's length is initially set to the
 127      * capacity.
 128      */
 129 #ifndef __LP64__
 130     virtual bool initWithOptions(   IOOptionBits options,
 131                                     vm_size_t    capacity,
 132                                     vm_offset_t  alignment) APPLE_KEXT_DEPRECATED; /* use withOptions() instead */
 133 #endif /* !__LP64__ */
 134
 135     static IOBufferMemoryDescriptor * withOptions(  IOOptionBits options,
 136                                                     vm_size_t    capacity,
 137                                                     vm_offset_t  alignment = 1);
 138
 139 /*! @function inTaskWithOptions
 140     @abstract Creates a memory buffer with memory descriptor for that buffer.
 141     @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.
 142     @param inTask The task the buffer will be allocated in.
 143     @param options Options for the allocation:<br>
 144     kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 145     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>
 146     kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
 147     kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
 148     kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.
 149     @param capacity The number of bytes to allocate.
 150     @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.
 151     @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 152
 153     static IOBufferMemoryDescriptor * inTaskWithOptions(
 154                                             task_t       inTask,
 155                                             IOOptionBits options,
 156                                             vm_size_t    capacity,
 157                                             vm_offset_t  alignment = 1);
 158
 159 /*! @function inTaskWithPhysicalMask
 160     @abstract Creates a memory buffer with memory descriptor for that buffer.
 161     @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.
 162     @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).
 163     @param options Options for the allocation:<br>
 164     kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 165     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>
 166     kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.
 167     @param capacity The number of bytes to allocate.
 168     @param mask 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.
 169     @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 170
 171     static IOBufferMemoryDescriptor * inTaskWithPhysicalMask(
 172                                             task_t            inTask,
 173                                             IOOptionBits      options,
 174                                             mach_vm_size_t    capacity,
 175                                             mach_vm_address_t physicalMask);
 176
 177     /*
 178      * withCapacity:
 179      *
 180      * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 181      * hold capacity bytes.  The descriptor's length is initially set to the
 182      * capacity.
 183      */
 184     static IOBufferMemoryDescriptor * withCapacity(
 185                                      vm_size_t    capacity,
 186                                      IODirection  withDirection,
 187                                      bool         withContiguousMemory = false);
 188 #ifndef __LP64__
 189     virtual bool initWithBytes(const void * bytes,
 190                                vm_size_t    withLength,
 191                                IODirection  withDirection,
 192                                bool         withContiguousMemory = false) APPLE_KEXT_DEPRECATED; /* use withBytes() instead */
 193 #endif /* !__LP64__ */
 194
 195     /*
 196      * withBytes:
 197      *
 198      * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 199      * The descriptor's length and capacity are set to the input buffer's size.
 200      */
 201     static IOBufferMemoryDescriptor * withBytes(
 202                                      const void * bytes,
 203                                      vm_size_t    withLength,
 204                                      IODirection  withDirection,
 205                                      bool         withContiguousMemory = false);
 206
 207     /*
 208      * setLength:
 209      *
 210      * Change the buffer length of the memory descriptor.  When a new buffer
 211      * is created, the initial length of the buffer is set to be the same as
 212      * the capacity.  The length can be adjusted via setLength for a shorter
 213      * transfer (there is no need to create more buffer descriptors when you
 214      * can reuse an existing one, even for different transfer sizes).   Note
 215      * that the specified length must not exceed the capacity of the buffer.
 216      */
 217     virtual void setLength(vm_size_t length);
 218
 219     /*
 220      * setDirection:
 221      *
 222      * Change the direction of the transfer.  This method allows one to redirect
 223      * the descriptor's transfer direction.  This eliminates the need to destroy
 224      * and create new buffers when different transfer directions are needed.
 225      */
 226     virtual void setDirection(IODirection direction);
 227
 228     /*
 229      * getCapacity:
 230      *
 231      * Get the buffer capacity
 232      */
 233     virtual vm_size_t getCapacity() const;
 234
 235     /*
 236      * getBytesNoCopy:
 237      *
 238      * Return the virtual address of the beginning of the buffer
 239      */
 240     virtual void *getBytesNoCopy();
 241
 242     /*
 243      * getBytesNoCopy:
 244      *
 245      * Return the virtual address of an offset from the beginning of the buffer
 246      */
 247     virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
 248
 249     /*
 250      * appendBytes:
 251      *
 252      * Add some data to the end of the buffer.  This method automatically
 253      * maintains the memory descriptor buffer length.  Note that appendBytes
 254      * will not copy past the end of the memory descriptor's current capacity.
 255      */
 256     virtual bool appendBytes(const void *bytes, vm_size_t withLength);
 257
 258 #ifndef __LP64__
 259     virtual void * getVirtualSegment(IOByteCount offset,
 260                                         IOByteCount * length) APPLE_KEXT_DEPRECATED; /* use getBytesNoCopy() instead */
 261 #endif /* !__LP64__ */
 262 };
 263
 264 #endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */