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     IOPhysicalAddress *  _physAddrs;
  76     unsigned             _physSegCount;
  77
  78 private:
  79     virtual bool initWithOptions(
  80                                IOOptionBits options,
  81                                vm_size_t    capacity,
  82                                vm_offset_t  alignment,
  83                                task_t       inTask);
  84
  85     virtual bool initWithPhysicalMask(
  86                                 task_t            inTask,
  87                                 IOOptionBits      options,
  88                                 mach_vm_size_t    capacity,
  89                                 mach_vm_address_t alignment,
  90                                 mach_vm_address_t physicalMask);
  91
  92     OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 0);
  93     OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 1);
  94     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
  95     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
  96     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 4);
  97     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 5);
  98     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 6);
  99     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 7);
 100     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 8);
 101     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 9);
 102     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 10);
 103     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 11);
 104     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 12);
 105     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 13);
 106     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 14);
 107     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 15);
 108
 109 protected:
 110     virtual void free();
 111
 112     virtual bool initWithAddress( void *      address,       /* not supported */
 113                                   IOByteCount withLength,
 114                                   IODirection withDirection );
 115
 116     virtual bool initWithAddress( vm_address_t address,      /* not supported */
 117                                   IOByteCount  withLength,
 118                                   IODirection  withDirection,
 119                                   task_t       withTask );
 120
 121     virtual bool initWithPhysicalAddress(
 122                                   IOPhysicalAddress address, /* not supported */
 123                                   IOByteCount       withLength,
 124                                   IODirection       withDirection );
 125
 126     virtual bool initWithPhysicalRanges(
 127                                   IOPhysicalRange * ranges,  /* not supported */
 128                                   UInt32            withCount,
 129                                   IODirection       withDirection,
 130                                   bool              asReference = false );
 131
 132     virtual bool initWithRanges(  IOVirtualRange * ranges,   /* not supported */
 133                                   UInt32           withCount,
 134                                   IODirection      withDirection,
 135                                   task_t           withTask,
 136                                   bool             asReference = false );
 137
 138     IOGeneralMemoryDescriptor::withAddress;                  /* not supported */
 139     IOGeneralMemoryDescriptor::withPhysicalAddress;          /* not supported */
 140     IOGeneralMemoryDescriptor::withPhysicalRanges;           /* not supported */
 141     IOGeneralMemoryDescriptor::withRanges;                   /* not supported */
 142     IOGeneralMemoryDescriptor::withSubRange;                 /* not supported */
 143
 144 public:
 145
 146     /*
 147      * withOptions:
 148      *
 149      * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 150      * hold capacity bytes.  The descriptor's length is initially set to the
 151      * capacity.
 152      */
 153     virtual bool initWithOptions(   IOOptionBits options,
 154                                     vm_size_t    capacity,
 155                                     vm_offset_t  alignment);
 156
 157     static IOBufferMemoryDescriptor * withOptions(  IOOptionBits options,
 158                                                     vm_size_t    capacity,
 159                                                     vm_offset_t  alignment = 1);
 160
 161 /*! @function inTaskWithOptions
 162     @abstract Creates a memory buffer with memory descriptor for that buffer.
 163     @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.
 164     @param inTask The task the buffer will be allocated in.
 165     @param options Options for the allocation:<br>
 166     kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 167     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>
 168     kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
 169     kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
 170     kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.
 171     @param capacity The number of bytes to allocate.
 172     @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.
 173     @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 174
 175     static IOBufferMemoryDescriptor * inTaskWithOptions(
 176                                             task_t       inTask,
 177                                             IOOptionBits options,
 178                                             vm_size_t    capacity,
 179                                             vm_offset_t  alignment = 1);
 180
 181 /*! @function inTaskWithPhysicalMask
 182     @abstract Creates a memory buffer with memory descriptor for that buffer.
 183     @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.
 184     @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).
 185     @param options Options for the allocation:<br>
 186     kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 187     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>
 188     kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.
 189     @param capacity The number of bytes to allocate.
 190     @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.
 191     @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 192
 193     static IOBufferMemoryDescriptor * inTaskWithPhysicalMask(
 194                                             task_t            inTask,
 195                                             IOOptionBits      options,
 196                                             mach_vm_size_t    capacity,
 197                                             mach_vm_address_t physicalMask);
 198
 199     /*
 200      * withCapacity:
 201      *
 202      * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 203      * hold capacity bytes.  The descriptor's length is initially set to the
 204      * capacity.
 205      */
 206     static IOBufferMemoryDescriptor * withCapacity(
 207                                      vm_size_t    capacity,
 208                                      IODirection  withDirection,
 209                                      bool         withContiguousMemory = false);
 210     /*
 211      * initWithBytes:
 212      *
 213      * Initialize a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 214      * The descriptor's length and capacity are set to the input buffer's size.
 215      */
 216     virtual bool initWithBytes(const void * bytes,
 217                                vm_size_t    withLength,
 218                                IODirection  withDirection,
 219                                bool         withContiguousMemory = false);
 220
 221     /*
 222      * withBytes:
 223      *
 224      * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 225      * The descriptor's length and capacity are set to the input buffer's size.
 226      */
 227     static IOBufferMemoryDescriptor * withBytes(
 228                                      const void * bytes,
 229                                      vm_size_t    withLength,
 230                                      IODirection  withDirection,
 231                                      bool         withContiguousMemory = false);
 232
 233     /*
 234      * setLength:
 235      *
 236      * Change the buffer length of the memory descriptor.  When a new buffer
 237      * is created, the initial length of the buffer is set to be the same as
 238      * the capacity.  The length can be adjusted via setLength for a shorter
 239      * transfer (there is no need to create more buffer descriptors when you
 240      * can reuse an existing one, even for different transfer sizes).   Note
 241      * that the specified length must not exceed the capacity of the buffer.
 242      */
 243     virtual void setLength(vm_size_t length);
 244
 245     /*
 246      * setDirection:
 247      *
 248      * Change the direction of the transfer.  This method allows one to redirect
 249      * the descriptor's transfer direction.  This eliminates the need to destroy
 250      * and create new buffers when different transfer directions are needed.
 251      */
 252     virtual void setDirection(IODirection direction);
 253
 254     /*
 255      * getCapacity:
 256      *
 257      * Get the buffer capacity
 258      */
 259     virtual vm_size_t getCapacity() const;
 260
 261     /*
 262      * getBytesNoCopy:
 263      *
 264      * Return the virtual address of the beginning of the buffer
 265      */
 266     virtual void *getBytesNoCopy();
 267
 268     /*
 269      * getBytesNoCopy:
 270      *
 271      * Return the virtual address of an offset from the beginning of the buffer
 272      */
 273     virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
 274
 275     /*
 276      * appendBytes:
 277      *
 278      * Add some data to the end of the buffer.  This method automatically
 279      * maintains the memory descriptor buffer length.  Note that appendBytes
 280      * will not copy past the end of the memory descriptor's current capacity.
 281      */
 282     virtual bool appendBytes(const void *bytes, vm_size_t withLength);
 283
 284     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 285     /* DEPRECATED */                                    IOByteCount * length);
 286 };
 287
 288 #endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */