iokit/IOKit/IOBufferMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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  25  * Please see the License for the specific language governing rights and
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  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 #ifndef _IOBUFFERMEMORYDESCRIPTOR_H
  31 #define _IOBUFFERMEMORYDESCRIPTOR_H
  32
  33 #include <IOKit/IOMemoryDescriptor.h>
  34
  35 enum {
  36     kIOMemoryPhysicallyContiguous       = 0x00000010,
  37     kIOMemoryPageable                   = 0x00000020,
  38     kIOMemoryPurgeable                  = 0x00000040,
  39     kIOMemorySharingTypeMask            = 0x000f0000,
  40     kIOMemoryUnshared                   = 0x00000000,
  41     kIOMemoryKernelUserShared           = 0x00010000
  42 };
  43
  44 #define _IOBUFFERMEMORYDESCRIPTOR_INTASKWITHOPTIONS_    1
  45 /*!
  46     @class IOBufferMemoryDescriptor
  47     @abstract Provides a simple memory descriptor that allocates its own buffer memory.
  48 */
  49
  50 class IOBufferMemoryDescriptor : public IOGeneralMemoryDescriptor
  51 {
  52     OSDeclareDefaultStructors(IOBufferMemoryDescriptor);
  53
  54 protected:
  55 /*! @struct ExpansionData
  56     @discussion This structure will be used to expand the capablilties of this class in the future.
  57     */
  58     struct ExpansionData {
  59         vm_map_t        map;
  60     };
  61
  62 /*! @var reserved
  63     Reserved for future use.  (Internal use only)  */
  64     ExpansionData * reserved;
  65
  66 protected:
  67     void *               _buffer;
  68     vm_size_t            _capacity;
  69     vm_offset_t          _alignment;
  70     IOOptionBits         _options;
  71     IOPhysicalAddress *  _physAddrs;
  72     unsigned             _physSegCount;
  73
  74 private:
  75     virtual bool initWithOptions(
  76                                IOOptionBits options,
  77                                vm_size_t    capacity,
  78                                vm_offset_t  alignment,
  79                                task_t       inTask);
  80     OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 0);
  81
  82 #if !(defined(__ppc__) && defined(KPI_10_4_0_PPC_COMPAT))
  83     virtual bool initWithPhysicalMask(
  84                                 task_t            inTask,
  85                                 IOOptionBits      options,
  86                                 mach_vm_size_t    capacity,
  87                                 mach_vm_address_t alignment,
  88                                 mach_vm_address_t physicalMask);
  89     OSMetaClassDeclareReservedUsed(IOBufferMemoryDescriptor, 1);
  90 #else
  91     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 1);
  92 #endif
  93     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
  94     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
  95     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 4);
  96     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 5);
  97     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 6);
  98     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 7);
  99     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 8);
 100     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 9);
 101     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 10);
 102     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 11);
 103     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 12);
 104     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 13);
 105     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 14);
 106     OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 15);
 107
 108 protected:
 109     virtual void free();
 110
 111     virtual bool initWithAddress( void *      address,       /* not supported */
 112                                   IOByteCount withLength,
 113                                   IODirection withDirection );
 114
 115     virtual bool initWithAddress( vm_address_t address,      /* not supported */
 116                                   IOByteCount  withLength,
 117                                   IODirection  withDirection,
 118                                   task_t       withTask );
 119
 120     virtual bool initWithPhysicalAddress(
 121                                   IOPhysicalAddress address, /* not supported */
 122                                   IOByteCount       withLength,
 123                                   IODirection       withDirection );
 124
 125     virtual bool initWithPhysicalRanges(
 126                                   IOPhysicalRange * ranges,  /* not supported */
 127                                   UInt32            withCount,
 128                                   IODirection       withDirection,
 129                                   bool              asReference = false );
 130
 131     virtual bool initWithRanges(  IOVirtualRange * ranges,   /* not supported */
 132                                   UInt32           withCount,
 133                                   IODirection      withDirection,
 134                                   task_t           withTask,
 135                                   bool             asReference = false );
 136
 137     IOGeneralMemoryDescriptor::withAddress;                  /* not supported */
 138     IOGeneralMemoryDescriptor::withPhysicalAddress;          /* not supported */
 139     IOGeneralMemoryDescriptor::withPhysicalRanges;           /* not supported */
 140     IOGeneralMemoryDescriptor::withRanges;                   /* not supported */
 141     IOGeneralMemoryDescriptor::withSubRange;                 /* not supported */
 142
 143 public:
 144
 145     /*
 146      * withOptions:
 147      *
 148      * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 149      * hold capacity bytes.  The descriptor's length is initially set to the
 150      * capacity.
 151      */
 152     virtual bool initWithOptions(   IOOptionBits options,
 153                                     vm_size_t    capacity,
 154                                     vm_offset_t  alignment);
 155
 156     static IOBufferMemoryDescriptor * withOptions(  IOOptionBits options,
 157                                                     vm_size_t    capacity,
 158                                                     vm_offset_t  alignment = 1);
 159
 160 /*! @function inTaskWithOptions
 161     @abstract Creates a memory buffer with memory descriptor for that buffer.
 162     @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.
 163     @param inTask The task the buffer will be allocated in.
 164     @param options Options for the allocation:<br>
 165     kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
 166     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>
 167     kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
 168     kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
 169     kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.
 170     @param capacity The number of bytes to allocate.
 171     @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.
 172     @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
 173
 174     static IOBufferMemoryDescriptor * inTaskWithOptions(
 175                                             task_t       inTask,
 176                                             IOOptionBits options,
 177                                             vm_size_t    capacity,
 178                                             vm_offset_t  alignment = 1);
 179
 180 #if !(defined(__ppc__) && defined(KPI_10_4_0_PPC_COMPAT))
 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 #endif
 199
 200     /*
 201      * withCapacity:
 202      *
 203      * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 204      * hold capacity bytes.  The descriptor's length is initially set to the
 205      * capacity.
 206      */
 207     static IOBufferMemoryDescriptor * withCapacity(
 208                                      vm_size_t    capacity,
 209                                      IODirection  withDirection,
 210                                      bool         withContiguousMemory = false);
 211     /*
 212      * initWithBytes:
 213      *
 214      * Initialize a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 215      * The descriptor's length and capacity are set to the input buffer's size.
 216      */
 217     virtual bool initWithBytes(const void * bytes,
 218                                vm_size_t    withLength,
 219                                IODirection  withDirection,
 220                                bool         withContiguousMemory = false);
 221
 222     /*
 223      * withBytes:
 224      *
 225      * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 226      * The descriptor's length and capacity are set to the input buffer's size.
 227      */
 228     static IOBufferMemoryDescriptor * withBytes(
 229                                      const void * bytes,
 230                                      vm_size_t    withLength,
 231                                      IODirection  withDirection,
 232                                      bool         withContiguousMemory = false);
 233
 234     /*
 235      * setLength:
 236      *
 237      * Change the buffer length of the memory descriptor.  When a new buffer
 238      * is created, the initial length of the buffer is set to be the same as
 239      * the capacity.  The length can be adjusted via setLength for a shorter
 240      * transfer (there is no need to create more buffer descriptors when you
 241      * can reuse an existing one, even for different transfer sizes).   Note
 242      * that the specified length must not exceed the capacity of the buffer.
 243      */
 244     virtual void setLength(vm_size_t length);
 245
 246     /*
 247      * setDirection:
 248      *
 249      * Change the direction of the transfer.  This method allows one to redirect
 250      * the descriptor's transfer direction.  This eliminates the need to destroy
 251      * and create new buffers when different transfer directions are needed.
 252      */
 253     virtual void setDirection(IODirection direction);
 254
 255     /*
 256      * getCapacity:
 257      *
 258      * Get the buffer capacity
 259      */
 260     virtual vm_size_t getCapacity() const;
 261
 262     /*
 263      * getBytesNoCopy:
 264      *
 265      * Return the virtual address of the beginning of the buffer
 266      */
 267     virtual void *getBytesNoCopy();
 268
 269     /*
 270      * getBytesNoCopy:
 271      *
 272      * Return the virtual address of an offset from the beginning of the buffer
 273      */
 274     virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
 275
 276     /*
 277      * appendBytes:
 278      *
 279      * Add some data to the end of the buffer.  This method automatically
 280      * maintains the memory descriptor buffer length.  Note that appendBytes
 281      * will not copy past the end of the memory descriptor's current capacity.
 282      */
 283     virtual bool appendBytes(const void *bytes, vm_size_t withLength);
 284
 285 #if !(defined(__ppc__) && defined(KPI_10_4_0_PPC_COMPAT))
 286     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 287     /* DEPRECATED */                                    IOByteCount * length);
 288 #endif
 289 };
 290
 291 #endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */