iokit/IOKit/IOMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
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   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
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  22  */
  23 #ifndef _IOMEMORYDESCRIPTOR_H
  24 #define _IOMEMORYDESCRIPTOR_H
  25
  26 #include <sys/cdefs.h>
  27
  28 #include <IOKit/IOTypes.h>
  29 #include <libkern/c++/OSContainers.h>
  30
  31 __BEGIN_DECLS
  32 #include <mach/memory_object_types.h>
  33 __END_DECLS
  34
  35 struct IOPhysicalRange
  36 {
  37     IOPhysicalAddress   address;
  38     IOByteCount         length;
  39 };
  40
  41 class IOMemoryMap;
  42 class IOMapper;
  43
  44 /*
  45  * Direction of transfer, with respect to the described memory.
  46  */
  47 enum IODirection
  48 {
  49     kIODirectionNone  = 0x0,    //                    same as VM_PROT_NONE
  50     kIODirectionIn    = 0x1,    // User land 'read',  same as VM_PROT_READ
  51     kIODirectionOut   = 0x2,    // User land 'write', same as VM_PROT_WRITE
  52     kIODirectionOutIn = kIODirectionOut | kIODirectionIn,
  53     kIODirectionInOut = kIODirectionIn  | kIODirectionOut
  54 };
  55
  56 /*
  57  * IOOptionBits used in the withOptions variant
  58  */
  59 enum {
  60     kIOMemoryDirectionMask      = 0x00000007,
  61     kIOMemoryAutoPrepare        = 0x00000008,   // Shared with Buffer MD
  62
  63     kIOMemoryTypeVirtual        = 0x00000010,
  64     kIOMemoryTypePhysical       = 0x00000020,
  65     kIOMemoryTypeUPL            = 0x00000030,
  66     kIOMemoryTypePersistentMD   = 0x00000040,   // Persistent Memory Descriptor
  67     kIOMemoryTypeUIO            = 0x00000050,
  68     kIOMemoryTypeMask           = 0x000000f0,
  69
  70     kIOMemoryAsReference        = 0x00000100,
  71     kIOMemoryBufferPageable     = 0x00000400,
  72     kIOMemoryDontMap            = 0x00000800,
  73     kIOMemoryPersistent         = 0x00010000
  74 };
  75
  76 #define kIOMapperNone   ((IOMapper *) -1)
  77 #define kIOMapperSystem ((IOMapper *) 0)
  78
  79 enum
  80 {
  81     kIOMemoryPurgeableKeepCurrent = 1,
  82     kIOMemoryPurgeableNonVolatile = 2,
  83     kIOMemoryPurgeableVolatile    = 3,
  84     kIOMemoryPurgeableEmpty       = 4
  85 };
  86 enum
  87 {
  88     kIOMemoryIncoherentIOFlush   = 1,
  89     kIOMemoryIncoherentIOStore   = 2,
  90 };
  91
  92 /*! @class IOMemoryDescriptor : public OSObject
  93     @abstract An abstract base class defining common methods for describing physical or virtual memory.
  94     @discussion The IOMemoryDescriptor object represents a buffer or range of memory, specified as one or more physical or virtual address ranges. It contains methods to return the memory's physically contiguous segments (fragments), for use with the IOMemoryCursor, and methods to map the memory into any address space with caching and placed mapping options. */
  95
  96 class IOMemoryDescriptor : public OSObject
  97 {
  98     friend class _IOMemoryMap;
  99     friend class IOSubMemoryDescriptor;
 100
 101     OSDeclareDefaultStructors(IOMemoryDescriptor);
 102
 103 protected:
 104 /*! @struct ExpansionData
 105     @discussion This structure will be used to expand the capablilties of this class in the future.
 106     */
 107     struct ExpansionData {
 108         void *                          devicePager;
 109         unsigned int                    pagerContig:1;
 110         unsigned int                    unused:31;
 111         IOMemoryDescriptor *            memory;
 112     };
 113
 114 /*! @var reserved
 115     Reserved for future use.  (Internal use only)  */
 116     ExpansionData * reserved;
 117
 118 protected:
 119     OSSet *             _mappings;
 120     IOOptionBits        _flags;
 121     void *              _memEntry;
 122
 123     IODirection         _direction;        /* DEPRECATED: use _flags instead. direction of transfer */
 124     IOByteCount         _length;           /* length of all ranges */
 125     IOOptionBits        _tag;
 126
 127 public:
 128
 129     virtual IOPhysicalAddress getSourceSegment( IOByteCount offset,
 130                                                 IOByteCount * length );
 131     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 0);
 132
 133 /*! @function initWithOptions
 134     @abstract Master initialiser for all variants of memory descriptors.  For a more complete description see IOMemoryDescriptor::withOptions.
 135     @discussion Note this function can be used to re-init a previously created memory descriptor.
 136     @result true on success, false on failure. */
 137     virtual bool initWithOptions(void *         buffers,
 138                                  UInt32         count,
 139                                  UInt32         offset,
 140                                  task_t         task,
 141                                  IOOptionBits   options,
 142                                  IOMapper *     mapper = 0);
 143     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 1);
 144
 145     virtual addr64_t getPhysicalSegment64( IOByteCount offset,
 146                                             IOByteCount * length );
 147     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 2);
 148
 149
 150 /*! @function setPurgeable
 151     @abstract Control the purgeable status of a memory descriptors memory.
 152     @discussion Buffers may be allocated with the ability to have their purgeable status changed - IOBufferMemoryDescriptor with the kIOMemoryPurgeable option, VM_FLAGS_PURGEABLE may be passed to vm_allocate() in user space to allocate such buffers. The purgeable status of such a buffer may be controlled with setPurgeable(). The process of making a purgeable memory descriptor non-volatile and determining its previous state is atomic - if a purgeable memory descriptor is made nonvolatile and the old state is returned as kIOMemoryPurgeableVolatile, then the memory's previous contents are completely intact and will remain so until the memory is made volatile again.  If the old state is returned as kIOMemoryPurgeableEmpty then the memory was reclaimed while it was in a volatile state and its previous contents have been lost.
 153     @param newState - the desired new purgeable state of the memory:<br>
 154     kIOMemoryPurgeableKeepCurrent - make no changes to the memory's purgeable state.<br>
 155     kIOMemoryPurgeableVolatile    - make the memory volatile - the memory may be reclaimed by the VM system without saving its contents to backing store.<br>
 156     kIOMemoryPurgeableNonVolatile - make the memory nonvolatile - the memory is treated as with usual allocations and must be saved to backing store if paged.<br>
 157     kIOMemoryPurgeableEmpty       - make the memory volatile, and discard any pages allocated to it.
 158     @param oldState - if non-NULL, the previous purgeable state of the memory is returned here:<br>
 159     kIOMemoryPurgeableNonVolatile - the memory was nonvolatile.<br>
 160     kIOMemoryPurgeableVolatile    - the memory was volatile but its content has not been discarded by the VM system.<br>
 161     kIOMemoryPurgeableEmpty       - the memory was volatile and has been discarded by the VM system.<br>
 162     @result An IOReturn code. */
 163
 164     virtual IOReturn setPurgeable( IOOptionBits newState,
 165                                     IOOptionBits * oldState );
 166     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 3);
 167
 168 /*! @function performOperation
 169     @abstract Perform an operation on the memory descriptor's memory.
 170     @discussion This method performs some operation on a range of the memory descriptor's memory. When a memory descriptor's memory is not mapped, it should be more efficient to use this method than mapping the memory to perform the operation virtually.
 171     @param options The operation to perform on the memory:<br>
 172     kIOMemoryIncoherentIOFlush - pass this option to store to memory and flush any data in the processor cache for the memory range, with synchronization to ensure the data has passed through all levels of processor cache. It may not be supported on all architectures. This type of flush may be used for non-coherent I/O such as AGP - it is NOT required for PCI coherent operations. The memory descriptor must have been previously prepared.<br>
 173     kIOMemoryIncoherentIOStore - pass this option to store to memory any data in the processor cache for the memory range, with synchronization to ensure the data has passed through all levels of processor cache. It may not be supported on all architectures. This type of flush may be used for non-coherent I/O such as AGP - it is NOT required for PCI coherent operations. The memory descriptor must have been previously prepared.
 174     @param offset A byte offset into the memory descriptor's memory.
 175     @param length The length of the data range.
 176     @result An IOReturn code. */
 177
 178     virtual IOReturn performOperation( IOOptionBits options,
 179                                         IOByteCount offset, IOByteCount length );
 180     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 4);
 181
 182 private:
 183
 184     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 5);
 185     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 6);
 186     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 7);
 187     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 8);
 188     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 9);
 189     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 10);
 190     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 11);
 191     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 12);
 192     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 13);
 193     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 14);
 194     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 15);
 195
 196 protected:
 197     virtual void free();
 198 public:
 199     static void initialize( void );
 200
 201 public:
 202 /*! @function withAddress
 203     @abstract Create an IOMemoryDescriptor to describe one virtual range of the kernel task.
 204     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the kernel map.
 205     @param address The virtual address of the first byte in the memory.
 206     @param withLength The length of memory.
 207     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 208     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 209
 210     static IOMemoryDescriptor * withAddress(void *       address,
 211                                             IOByteCount  withLength,
 212                                             IODirection  withDirection);
 213
 214 /*! @function withAddress
 215     @abstract Create an IOMemoryDescriptor to describe one virtual range of the specified map.
 216     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the specified map.
 217     @param address The virtual address of the first byte in the memory.
 218     @param withLength The length of memory.
 219     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 220     @param withTask The task the virtual ranges are mapped into.
 221     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 222
 223     static IOMemoryDescriptor * withAddress(vm_address_t address,
 224                                             IOByteCount  withLength,
 225                                             IODirection  withDirection,
 226                                             task_t       withTask);
 227
 228 /*! @function withPhysicalAddress
 229     @abstract Create an IOMemoryDescriptor to describe one physical range.
 230     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single physical memory range.
 231     @param address The physical address of the first byte in the memory.
 232     @param withLength The length of memory.
 233     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 234     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 235
 236     static IOMemoryDescriptor * withPhysicalAddress(
 237                                 IOPhysicalAddress       address,
 238                                 IOByteCount             withLength,
 239                                 IODirection             withDirection );
 240
 241 /*! @function withRanges
 242     @abstract Create an IOMemoryDescriptor to describe one or more virtual ranges.
 243     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of an array of virtual memory ranges each mapped into a specified source task.
 244     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 245     @param withCount The member count of the ranges array.
 246     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 247     @param withTask The task each of the virtual ranges are mapped into.
 248     @param asReference If false, the IOMemoryDescriptor object will make a copy of the ranges array, otherwise, the array will be used in situ, avoiding an extra allocation.
 249     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 250
 251      static IOMemoryDescriptor * withRanges(IOVirtualRange * ranges,
 252                                             UInt32           withCount,
 253                                             IODirection      withDirection,
 254                                             task_t           withTask,
 255                                             bool             asReference = false);
 256
 257 /*! @function withOptions
 258     @abstract Master initialiser for all variants of memory descriptors.
 259     @discussion This method creates and initializes an IOMemoryDescriptor for memory it has three main variants: Virtual, Physical & mach UPL.  These variants are selected with the options parameter, see below.  This memory descriptor needs to be prepared before it can be used to extract data from the memory described.  However we temporarily have setup a mechanism that automatically prepares kernel_task memory descriptors at creation time.
 260
 261
 262     @param buffers A pointer to an array of IOVirtualRanges or IOPhysicalRanges if the options:type is Virtual or Physical.  For type UPL it is a upl_t returned by the mach/memory_object_types.h apis, primarily used internally by the UBC.
 263
 264     @param count options:type = Virtual or Physical count contains a count of the number of entires in the buffers array.  For options:type = UPL this field contains a total length.
 265
 266     @param offset Only used when options:type = UPL, in which case this field contains an offset for the memory within the buffers upl.
 267
 268     @param task Only used options:type = Virtual, The task each of the virtual ranges are mapped into.
 269
 270     @param options
 271         kIOMemoryDirectionMask (options:direction)      This nibble indicates the I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 272         kIOMemoryTypeMask (options:type)        kIOMemoryTypeVirtual, kIOMemoryTypePhysical, kIOMemoryTypeUPL Indicates that what type of memory basic memory descriptor to use.  This sub-field also controls the interpretation of the buffers, count, offset & task parameters.
 273         kIOMemoryAsReference    For options:type = Virtual or Physical this indicate that the memory descriptor need not copy the ranges array into local memory.  This is an optimisation to try to minimise unnecessary allocations.
 274         kIOMemoryBufferPageable Only used by the IOBufferMemoryDescriptor as an indication that the kernel virtual memory is in fact pageable and we need to use the kernel pageable submap rather than the default map.
 275         kIOMemoryNoAutoPrepare  Indicates that the temporary AutoPrepare of kernel_task memory should not be performed.
 276
 277     @param mapper Which IOMapper should be used to map the in-memory physical addresses into I/O space addresses.  Defaults to 0 which indicates that the system mapper is to be used, if present.
 278
 279     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 280
 281     static IOMemoryDescriptor *withOptions(void *       buffers,
 282                                            UInt32       count,
 283                                            UInt32       offset,
 284                                            task_t       task,
 285                                            IOOptionBits options,
 286                                            IOMapper *   mapper = 0);
 287
 288 /*! @function withPhysicalRanges
 289     @abstract Create an IOMemoryDescriptor to describe one or more physical ranges.
 290     @discussion  This method creates and initializes an IOMemoryDescriptor for memory consisting of an array of physical memory ranges.
 291     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 292     @param withCount The member count of the ranges array.
 293     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 294     @param asReference If false, the IOMemoryDescriptor object will make a copy of the ranges array, otherwise, the array will be used in situ, avoiding an extra allocation.
 295     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 296
 297     static IOMemoryDescriptor * withPhysicalRanges(
 298                                             IOPhysicalRange *   ranges,
 299                                             UInt32              withCount,
 300                                             IODirection         withDirection,
 301                                             bool                asReference = false);
 302
 303 /*! @function withSubRange
 304     @abstract Create an IOMemoryDescriptor to describe a subrange of an existing descriptor.
 305     @discussion  This method creates and initializes an IOMemoryDescriptor for memory consisting of a subrange of the specified memory descriptor. The parent memory descriptor is retained by the new descriptor.
 306     @param of The parent IOMemoryDescriptor of which a subrange is to be used for the new descriptor, which will be retained by the subrange IOMemoryDescriptor.
 307     @param offset A byte offset into the parent memory descriptor's memory.
 308     @param length The length of the subrange.
 309     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures. This is used over the direction of the parent descriptor.
 310     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 311
 312     static IOMemoryDescriptor * withSubRange(IOMemoryDescriptor *of,
 313                                              IOByteCount offset,
 314                                              IOByteCount length,
 315                                              IODirection withDirection);
 316
 317 /*! @function withPersistentMemoryDescriptor
 318     @abstract Copy constructor that generates a new memory descriptor if the backing memory for the same task's virtual address and length has changed.
 319     @discussion If the original memory descriptor's address and length is still backed by the same real memory, i.e. the user hasn't deallocated and the reallocated memory at the same address then the original memory descriptor is returned with a additional reference.  Otherwise we build a totally new memory descriptor with the same characteristics as the previous one but with a new view of the vm.  Note not legal to call this function with anything except an IOGeneralMemoryDescriptor that was created with the kIOMemoryPersistent option.
 320     @param originalMD The memory descriptor to be duplicated.
 321     @result Either the original memory descriptor with an additional retain or a new memory descriptor, 0 for a bad original memory descriptor or some other resource shortage. */
 322     static IOMemoryDescriptor *
 323         withPersistentMemoryDescriptor(IOMemoryDescriptor *originalMD);
 324
 325 /*! @function initWithAddress
 326     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the kernel task.
 327     @discussion This method initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the kernel map. An IOMemoryDescriptor can be re-used by calling initWithAddress or initWithRanges again on an existing instance -- note this behavior is not commonly supported in other IOKit classes, although it is supported here.
 328     @param address The virtual address of the first byte in the memory.
 329     @param withLength The length of memory.
 330     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 331     @result true on success, false on failure. */
 332
 333     virtual bool initWithAddress(void *       address,
 334                                  IOByteCount  withLength,
 335                                  IODirection  withDirection) = 0;
 336
 337 /*! @function initWithAddress
 338     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the specified map.
 339     @discussion This method initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the specified map. An IOMemoryDescriptor can be re-used by calling initWithAddress or initWithRanges again on an existing instance -- note this behavior is not commonly supported in other IOKit classes, although it is supported here.
 340     @param address The virtual address of the first byte in the memory.
 341     @param withLength The length of memory.
 342     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 343     @param withTask The task the virtual ranges are mapped into.
 344     @result true on success, false on failure. */
 345
 346     virtual bool initWithAddress(vm_address_t address,
 347                                  IOByteCount  withLength,
 348                                  IODirection  withDirection,
 349                                  task_t       withTask) = 0;
 350
 351 /*! @function initWithPhysicalAddress
 352     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one physical range.
 353     @discussion This method initializes an IOMemoryDescriptor for memory consisting of a single physical memory range. An IOMemoryDescriptor can be re-used by calling initWithAddress or initWithRanges again on an existing instance -- note this behavior is not commonly supported in other IOKit classes, although it is supported here.
 354     @param address The physical address of the first byte in the memory.
 355     @param withLength The length of memory.
 356     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 357     @result true on success, false on failure. */
 358
 359     virtual bool initWithPhysicalAddress(
 360                                  IOPhysicalAddress      address,
 361                                  IOByteCount            withLength,
 362                                  IODirection            withDirection ) = 0;
 363
 364 /*! @function initWithRanges
 365     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more virtual ranges.
 366     @discussion This method initializes an IOMemoryDescriptor for memory consisting of an array of virtual memory ranges each mapped into a specified source task. An IOMemoryDescriptor can be re-used by calling initWithAddress or initWithRanges again on an existing instance -- note this behavior is not commonly supported in other IOKit classes, although it is supported here.
 367     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 368     @param withCount The member count of the ranges array.
 369     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 370     @param withTask The task each of the virtual ranges are mapped into.
 371     @param asReference If false, the IOMemoryDescriptor object will make a copy of the ranges array, otherwise, the array will be used in situ, avoiding an extra allocation.
 372     @result true on success, false on failure. */
 373
 374     virtual bool initWithRanges(IOVirtualRange * ranges,
 375                                 UInt32           withCount,
 376                                 IODirection      withDirection,
 377                                 task_t           withTask,
 378                                 bool             asReference = false) = 0;
 379
 380 /*! @function initWithPhysicalRanges
 381     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more physical ranges.
 382     @discussion  This method initializes an IOMemoryDescriptor for memory consisting of an array of physical memory ranges. An IOMemoryDescriptor can be re-used by calling initWithAddress or initWithRanges again on an existing instance -- note this behavior is not commonly supported in other IOKit classes, although it is supported here.
 383     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 384     @param withCount The member count of the ranges array.
 385     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 386     @param asReference If false, the IOMemoryDescriptor object will make a copy of the ranges array, otherwise, the array will be used in situ, avoiding an extra allocation.
 387     @result true on success, false on failure. */
 388
 389     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 390                                         UInt32           withCount,
 391                                         IODirection      withDirection,
 392                                         bool             asReference = false) = 0;
 393
 394 /*! @function getDirection
 395     @abstract Accessor to get the direction the memory descriptor was created with.
 396     @discussion This method returns the direction the memory descriptor was created with.
 397     @result The direction. */
 398
 399     virtual IODirection getDirection() const;
 400
 401 /*! @function getLength
 402     @abstract Accessor to get the length of the memory descriptor (over all its ranges).
 403     @discussion This method returns the total length of the memory described by the descriptor, ie. the sum of its ranges' lengths.
 404     @result The byte count. */
 405
 406     virtual IOByteCount getLength() const;
 407
 408 /*! @function setTag
 409     @abstract Set the tag for the memory descriptor.
 410     @discussion This method sets the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 411     @param tag The tag. */
 412
 413     virtual void setTag( IOOptionBits tag );
 414
 415 /*! @function getTag
 416     @abstract Accessor to the retrieve the tag for the memory descriptor.
 417     @discussion This method returns the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 418     @result The tag. */
 419
 420     virtual IOOptionBits getTag( void );
 421
 422 /*! @function readBytes
 423     @abstract Copy data from the memory descriptor's buffer to the specified buffer.
 424     @discussion This method copies data from the memory descriptor's memory at the given offset, to the caller's buffer.
 425     @param offset A byte offset into the memory descriptor's memory.
 426     @param bytes The caller supplied buffer to copy the data to.
 427     @param withLength The length of the data to copy.
 428     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 429
 430     virtual IOByteCount readBytes(IOByteCount offset,
 431                                 void * bytes, IOByteCount withLength);
 432
 433 /*! @function writeBytes
 434     @abstract Copy data to the memory descriptor's buffer from the specified buffer.
 435     @discussion This method copies data to the memory descriptor's memory at the given offset, from the caller's buffer.
 436     @param offset A byte offset into the memory descriptor's memory.
 437     @param bytes The caller supplied buffer to copy the data from.
 438     @param withLength The length of the data to copy.
 439     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 440
 441     virtual IOByteCount writeBytes(IOByteCount offset,
 442                                 const void * bytes, IOByteCount withLength);
 443
 444 /*! @function getPhysicalSegment
 445     @abstract Break a memory descriptor into its physically contiguous segments.
 446     @discussion This method returns the physical address of the byte at the given offset into the memory, and optionally the length of the physically contiguous segment from that offset.
 447     @param offset A byte offset into the memory whose physical address to return.
 448     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 449     @result A physical address, or zero if the offset is beyond the length of the memory. */
 450
 451     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 452                                                  IOByteCount * length) = 0;
 453
 454 /*! @function getPhysicalAddress
 455     @abstract Return the physical address of the first byte in the memory.
 456     @discussion This method returns the physical address of the  first byte in the memory. It is most useful on memory known to be physically contiguous.
 457     @result A physical address. */
 458
 459     /* inline */ IOPhysicalAddress getPhysicalAddress();
 460         /* { return( getPhysicalSegment( 0, 0 )); } */
 461
 462     /* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
 463     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 464     /* DEPRECATED */                                    IOByteCount * length) = 0;
 465     /* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
 466
 467 /*! @function prepare
 468     @abstract Prepare the memory for an I/O transfer.
 469     @discussion This involves paging in the memory, if necessary, and wiring it down for the duration of the transfer.  The complete() method completes the processing of the memory after the I/O transfer finishes.  Note that the prepare call is not thread safe and it is expected that the client will more easily be able to guarantee single threading a particular memory descriptor.
 470     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 471     @result An IOReturn code. */
 472
 473     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) = 0;
 474
 475 /*! @function complete
 476     @abstract Complete processing of the memory after an I/O transfer finishes.
 477     @discussion This method should not be called unless a prepare was previously issued; the prepare() and complete() must occur in pairs, before and after an I/O transfer involving pageable memory.  In 10.3 or greater systems the direction argument to complete is not longer respected.  The direction is totally determined at prepare() time.
 478     @param forDirection DEPRECATED The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 479     @result An IOReturn code. */
 480
 481     virtual IOReturn complete(IODirection forDirection = kIODirectionNone) = 0;
 482
 483     /*
 484      * Mapping functions.
 485      */
 486
 487 /*! @function map
 488     @abstract Maps a IOMemoryDescriptor into a task.
 489     @discussion This is the general purpose method to map all or part of the memory described by a memory descriptor into a task at any available address, or at a fixed address if possible. Caching & read-only options may be set for the mapping. The mapping is represented as a returned reference to a IOMemoryMap object, which may be shared if the mapping is compatible with an existing mapping of the IOMemoryDescriptor. The IOMemoryMap object returned should be released only when the caller has finished accessing the mapping, as freeing the object destroys the mapping.
 490     @param intoTask Sets the target task for the mapping. Pass kernel_task for the kernel address space.
 491     @param atAddress If a placed mapping is requested, atAddress specifies its address, and the kIOMapAnywhere should not be set. Otherwise, atAddress is ignored.
 492     @param options Mapping options are defined in IOTypes.h,<br>
 493         kIOMapAnywhere should be passed if the mapping can be created anywhere. If not set, the atAddress parameter sets the location of the mapping, if it is available in the target map.<br>
 494         kIOMapDefaultCache to inhibit the cache in I/O areas, kIOMapCopybackCache in general purpose RAM.<br>
 495         kIOMapInhibitCache, kIOMapWriteThruCache, kIOMapCopybackCache to set the appropriate caching.<br>
 496         kIOMapReadOnly to allow only read only accesses to the memory - writes will cause and access fault.<br>
 497         kIOMapReference will only succeed if the mapping already exists, and the IOMemoryMap object is just an extra reference, ie. no new mapping will be created.<br>
 498         kIOMapUnique allows a special kind of mapping to be created that may be used with the IOMemoryMap::redirect() API. These mappings will not be shared as is the default - there will always be a unique mapping created for the caller, not an existing mapping with an extra reference.<br>
 499     @param offset Is a beginning offset into the IOMemoryDescriptor's memory where the mapping starts. Zero is the default to map all the memory.
 500     @param length Is the length of the mapping requested for a subset of the IOMemoryDescriptor. Zero is the default to map all the memory.
 501     @result A reference to an IOMemoryMap object representing the mapping, which can supply the virtual address of the mapping and other information. The mapping may be shared with multiple callers - multiple maps are avoided if a compatible one exists. The IOMemoryMap object returned should be released only when the caller has finished accessing the mapping, as freeing the object destroys the mapping. The IOMemoryMap instance also retains the IOMemoryDescriptor it maps while it exists. */
 502
 503     virtual IOMemoryMap *       map(
 504         task_t          intoTask,
 505         IOVirtualAddress        atAddress,
 506         IOOptionBits            options,
 507         IOByteCount             offset = 0,
 508         IOByteCount             length = 0 );
 509
 510 /*! @function map
 511     @abstract Maps a IOMemoryDescriptor into the kernel map.
 512     @discussion This is a shortcut method to map all the memory described by a memory descriptor into the kernel map at any available address. See the full version of the map method for further details.
 513     @param options Mapping options as in the full version of the map method, with kIOMapAnywhere assumed.
 514     @result See the full version of the map method. */
 515
 516     virtual IOMemoryMap *       map(
 517         IOOptionBits            options = 0 );
 518
 519 /*! @function setMapping
 520     @abstract Establishes an already existing mapping.
 521     @discussion This method tells the IOMemoryDescriptor about a mapping that exists, but was created elsewhere. It allows later callers of the map method to share this externally created mapping. The IOMemoryMap object returned is created to represent it. This method is not commonly needed.
 522     @param task Address space in which the mapping exists.
 523     @param mapAddress Virtual address of the mapping.
 524     @param options Caching and read-only attributes of the mapping.
 525     @result A IOMemoryMap object created to represent the mapping. */
 526
 527     virtual IOMemoryMap *       setMapping(
 528         task_t          task,
 529         IOVirtualAddress        mapAddress,
 530         IOOptionBits            options = 0 );
 531
 532     // Following methods are private implementation
 533
 534     // make virtual
 535     IOReturn redirect( task_t safeTask, bool redirect );
 536
 537     IOReturn handleFault(
 538         void *                  pager,
 539         vm_map_t                addressMap,
 540         IOVirtualAddress        address,
 541         IOByteCount             sourceOffset,
 542         IOByteCount             length,
 543         IOOptionBits            options );
 544
 545 protected:
 546     virtual IOMemoryMap *       makeMapping(
 547         IOMemoryDescriptor *    owner,
 548         task_t          intoTask,
 549         IOVirtualAddress        atAddress,
 550         IOOptionBits            options,
 551         IOByteCount             offset,
 552         IOByteCount             length );
 553
 554     virtual void                addMapping(
 555         IOMemoryMap *           mapping );
 556
 557     virtual void                removeMapping(
 558         IOMemoryMap *           mapping );
 559
 560     virtual IOReturn doMap(
 561         vm_map_t                addressMap,
 562         IOVirtualAddress *      atAddress,
 563         IOOptionBits            options,
 564         IOByteCount             sourceOffset = 0,
 565         IOByteCount             length = 0 );
 566
 567     virtual IOReturn doUnmap(
 568         vm_map_t                addressMap,
 569         IOVirtualAddress        logical,
 570         IOByteCount             length );
 571 };
 572
 573 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 574
 575 /*! @class IOMemoryMap : public OSObject
 576     @abstract An abstract base class defining common methods for describing a memory mapping.
 577     @discussion The IOMemoryMap object represents a mapped range of memory, described by a IOMemoryDescriptor. The mapping may be in the kernel or a non-kernel task and has processor cache mode attributes. IOMemoryMap instances are created by IOMemoryDescriptor when it creates mappings in its map method, and returned to the caller. */
 578
 579 class IOMemoryMap : public OSObject
 580 {
 581     OSDeclareAbstractStructors(IOMemoryMap)
 582
 583 public:
 584 /*! @function getVirtualAddress
 585     @abstract Accessor to the virtual address of the first byte in the mapping.
 586     @discussion This method returns the virtual address of the first byte in the mapping.
 587     @result A virtual address. */
 588
 589     virtual IOVirtualAddress    getVirtualAddress() = 0;
 590
 591 /*! @function getPhysicalSegment
 592     @abstract Break a mapping into its physically contiguous segments.
 593     @discussion This method returns the physical address of the byte at the given offset into the mapping, and optionally the length of the physically contiguous segment from that offset. It functions similarly to IOMemoryDescriptor::getPhysicalSegment.
 594     @param offset A byte offset into the mapping whose physical address to return.
 595     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 596     @result A physical address, or zero if the offset is beyond the length of the mapping. */
 597
 598     virtual IOPhysicalAddress   getPhysicalSegment(IOByteCount offset,
 599                                                    IOByteCount * length) = 0;
 600
 601 /*! @function getPhysicalAddress
 602     @abstract Return the physical address of the first byte in the mapping.
 603     @discussion This method returns the physical address of the  first byte in the mapping. It is most useful on mappings known to be physically contiguous.
 604     @result A physical address. */
 605
 606     /* inline */ IOPhysicalAddress getPhysicalAddress();
 607         /* { return( getPhysicalSegment( 0, 0 )); } */
 608
 609 /*! @function getLength
 610     @abstract Accessor to the length of the mapping.
 611     @discussion This method returns the length of the mapping.
 612     @result A byte count. */
 613
 614     virtual IOByteCount         getLength() = 0;
 615
 616 /*! @function getAddressTask
 617     @abstract Accessor to the task of the mapping.
 618     @discussion This method returns the mach task the mapping exists in.
 619     @result A mach task_t. */
 620
 621     virtual task_t              getAddressTask() = 0;
 622
 623 /*! @function getMemoryDescriptor
 624     @abstract Accessor to the IOMemoryDescriptor the mapping was created from.
 625     @discussion This method returns the IOMemoryDescriptor the mapping was created from.
 626     @result An IOMemoryDescriptor reference, which is valid while the IOMemoryMap object is retained. It should not be released by the caller. */
 627
 628     virtual IOMemoryDescriptor * getMemoryDescriptor() = 0;
 629
 630 /*! @function getMapOptions
 631     @abstract Accessor to the options the mapping was created with.
 632     @discussion This method returns the options to IOMemoryDescriptor::map the mapping was created with.
 633     @result Options for the mapping, including cache settings. */
 634
 635     virtual IOOptionBits        getMapOptions() = 0;
 636
 637 /*! @function unmap
 638     @abstract Force the IOMemoryMap to unmap, without destroying the object.
 639     @discussion IOMemoryMap instances will unmap themselves upon free, ie. when the last client with a reference calls release. This method forces the IOMemoryMap to destroy the mapping it represents, regardless of the number of clients. It is not generally used.
 640     @result An IOReturn code. */
 641
 642     virtual IOReturn            unmap() = 0;
 643
 644     virtual void                taskDied() = 0;
 645
 646 /*! @function redirect
 647     @abstract Replace the memory mapped in a process with new backing memory.
 648     @discussion An IOMemoryMap created with the kIOMapUnique option to IOMemoryDescriptor::map() can remapped to a new IOMemoryDescriptor backing object. If the new IOMemoryDescriptor is specified as NULL, client access to the memory map is blocked until a new backing object has been set. By blocking access and copying data, the caller can create atomic copies of the memory while the client is potentially reading or writing the memory.
 649     @param newBackingMemory The IOMemoryDescriptor that represents the physical memory that is to be now mapped in the virtual range the IOMemoryMap represents. If newBackingMemory is NULL, any access to the mapping will hang (in vm_fault()) until access has been restored by a new call to redirect() with non-NULL newBackingMemory argument.
 650     @param options Mapping options are defined in IOTypes.h, and are documented in IOMemoryDescriptor::map()
 651     @param offset As with IOMemoryDescriptor::map(), a beginning offset into the IOMemoryDescriptor's memory where the mapping starts. Zero is the default.
 652     @result An IOReturn code. */
 653
 654     virtual IOReturn            redirect(IOMemoryDescriptor * newBackingMemory,
 655                                          IOOptionBits         options,
 656                                          IOByteCount          offset = 0) = 0;
 657 };
 658
 659 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 660
 661 // The following classes are private implementation of IOMemoryDescriptor - they
 662 // should not be referenced directly, just through the public API's in the
 663 // IOMemoryDescriptor class. For example, an IOGeneralMemoryDescriptor instance
 664 // might be created by IOMemoryDescriptor::withAddress(), but there should be
 665 // no need to reference as anything but a generic IOMemoryDescriptor *.
 666
 667 // Also these flags should not overlap with the options to
 668 //      IOMemoryDescriptor::initWithRanges(... IOOptionsBits options);
 669
 670 enum {
 671     kIOMemoryPreparedReadOnly   = 0x00008000,
 672 };
 673
 674 class IOGeneralMemoryDescriptor : public IOMemoryDescriptor
 675 {
 676     OSDeclareDefaultStructors(IOGeneralMemoryDescriptor);
 677
 678 public:
 679     union Ranges {
 680         IOVirtualRange *  v;
 681         IOPhysicalRange * p;
 682         void             *uio;
 683     };
 684 protected:
 685     Ranges              _ranges;
 686     unsigned            _rangesCount;       /* number of address ranges in list */
 687     bool                _rangesIsAllocated; /* is list allocated by us? */
 688
 689     task_t              _task;               /* task where all ranges are mapped to */
 690
 691     union {
 692         IOVirtualRange  v;
 693         IOPhysicalRange p;
 694     }                   _singleRange;      /* storage space for a single range */
 695
 696     unsigned            _wireCount;        /* number of outstanding wires */
 697
 698     /* DEPRECATED */ vm_address_t _cachedVirtualAddress;  /* a cached virtual-to-physical */
 699
 700     /* DEPRECATED */ IOPhysicalAddress  _cachedPhysicalAddress;
 701
 702     bool                _initialized;      /* has superclass been initialized? */
 703
 704     virtual void free();
 705
 706
 707 private:
 708     // Internal APIs may be made virtual at some time in the future.
 709     IOReturn wireVirtual(IODirection forDirection);
 710     void *createNamedEntry();
 711
 712
 713     /* DEPRECATED */ IOByteCount _position; /* absolute position over all ranges */
 714     /* DEPRECATED */ virtual void setPosition(IOByteCount position);
 715
 716 /*
 717  * DEPRECATED IOByteCount _positionAtIndex; // relative position within range #n
 718  *
 719  * Re-use the _positionAtIndex as a count of the number of pages in
 720  * this memory descriptor.  Convieniently vm_address_t is an unsigned integer
 721  * type so I can get away without having to change the type.
 722  */
 723     unsigned int                _pages;
 724
 725 /* DEPRECATED */ unsigned    _positionAtOffset;  //range #n in which position is now
 726
 727     OSData *_memoryEntries;
 728
 729     /* DEPRECATED */ vm_offset_t _kernPtrAligned;
 730     /* DEPRECATED */ unsigned    _kernPtrAtIndex;
 731     /* DEPRECATED */ IOByteCount  _kernSize;
 732
 733     /* DEPRECATED */ virtual void mapIntoKernel(unsigned rangeIndex);
 734     /* DEPRECATED */ virtual void unmapFromKernel();
 735
 736 public:
 737     /*
 738      * IOMemoryDescriptor required methods
 739      */
 740
 741     // Master initaliser
 742     virtual bool initWithOptions(void *         buffers,
 743                                  UInt32         count,
 744                                  UInt32         offset,
 745                                  task_t         task,
 746                                  IOOptionBits   options,
 747                                  IOMapper *     mapper = 0);
 748
 749     // Secondary initialisers
 750     virtual bool initWithAddress(void *         address,
 751                                  IOByteCount    withLength,
 752                                  IODirection    withDirection);
 753
 754     virtual bool initWithAddress(vm_address_t   address,
 755                                  IOByteCount    withLength,
 756                                  IODirection    withDirection,
 757                                  task_t         withTask);
 758
 759     virtual bool initWithPhysicalAddress(
 760                                  IOPhysicalAddress      address,
 761                                  IOByteCount            withLength,
 762                                  IODirection            withDirection );
 763
 764     virtual bool initWithRanges(        IOVirtualRange * ranges,
 765                                         UInt32           withCount,
 766                                         IODirection      withDirection,
 767                                         task_t           withTask,
 768                                         bool             asReference = false);
 769
 770     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 771                                         UInt32           withCount,
 772                                         IODirection      withDirection,
 773                                         bool             asReference = false);
 774
 775     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 776                                                  IOByteCount * length);
 777
 778     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 779                                                IOByteCount * length);
 780
 781     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 782     /* DEPRECATED */                                    IOByteCount * length);
 783
 784     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 785
 786     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 787
 788     virtual IOReturn doMap(
 789         vm_map_t                addressMap,
 790         IOVirtualAddress *      atAddress,
 791         IOOptionBits            options,
 792         IOByteCount             sourceOffset = 0,
 793         IOByteCount             length = 0 );
 794
 795     virtual IOReturn doUnmap(
 796         vm_map_t                addressMap,
 797         IOVirtualAddress        logical,
 798         IOByteCount             length );
 799     virtual bool serialize(OSSerialize *s) const;
 800
 801     // Factory method for cloning a persistent IOMD, see IOMemoryDescriptor
 802     static IOMemoryDescriptor *
 803         withPersistentMemoryDescriptor(IOGeneralMemoryDescriptor *originalMD);
 804 };
 805
 806 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 807
 808 class IOSubMemoryDescriptor : public IOMemoryDescriptor
 809 {
 810     friend class IOMemoryDescriptor;
 811
 812     OSDeclareDefaultStructors(IOSubMemoryDescriptor);
 813
 814 protected:
 815     IOMemoryDescriptor * _parent;
 816     IOByteCount          _start;
 817
 818     virtual void free();
 819
 820     virtual bool initWithAddress(void *       address,
 821                                  IOByteCount    withLength,
 822                                  IODirection  withDirection);
 823
 824     virtual bool initWithAddress(vm_address_t address,
 825                                  IOByteCount    withLength,
 826                                  IODirection  withDirection,
 827                                  task_t       withTask);
 828
 829     virtual bool initWithPhysicalAddress(
 830                                  IOPhysicalAddress      address,
 831                                  IOByteCount            withLength,
 832                                  IODirection            withDirection );
 833
 834     virtual bool initWithRanges(        IOVirtualRange * ranges,
 835                                         UInt32           withCount,
 836                                         IODirection      withDirection,
 837                                         task_t           withTask,
 838                                         bool             asReference = false);
 839
 840     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 841                                         UInt32           withCount,
 842                                         IODirection      withDirection,
 843                                         bool             asReference = false);
 844
 845     IOMemoryDescriptor::withAddress;
 846     IOMemoryDescriptor::withPhysicalAddress;
 847     IOMemoryDescriptor::withPhysicalRanges;
 848     IOMemoryDescriptor::withRanges;
 849     IOMemoryDescriptor::withSubRange;
 850
 851 public:
 852     /*
 853      * Initialize or reinitialize an IOSubMemoryDescriptor to describe
 854      * a subrange of an existing descriptor.
 855      *
 856      * An IOSubMemoryDescriptor can be re-used by calling initSubRange
 857      * again on an existing instance -- note that this behavior is not
 858      * commonly supported in other IOKit classes, although it is here.
 859      */
 860     virtual bool initSubRange( IOMemoryDescriptor * parent,
 861                                 IOByteCount offset, IOByteCount length,
 862                                 IODirection withDirection );
 863
 864     /*
 865      * IOMemoryDescriptor required methods
 866      */
 867
 868     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 869                                                  IOByteCount * length);
 870
 871     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 872                                                IOByteCount * length);
 873
 874     virtual IOByteCount readBytes(IOByteCount offset,
 875                                 void * bytes, IOByteCount withLength);
 876
 877     virtual IOByteCount writeBytes(IOByteCount offset,
 878                                 const void * bytes, IOByteCount withLength);
 879
 880     virtual void * getVirtualSegment(IOByteCount offset,
 881                                         IOByteCount * length);
 882
 883     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 884
 885     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 886
 887     // make virtual
 888     IOReturn redirect( task_t safeTask, bool redirect );
 889
 890     virtual bool serialize(OSSerialize *s) const;
 891
 892     virtual IOReturn setPurgeable( IOOptionBits newState,
 893                                     IOOptionBits * oldState );
 894     virtual IOReturn performOperation( IOOptionBits options,
 895                                         IOByteCount offset, IOByteCount length );
 896
 897 protected:
 898     virtual IOMemoryMap *       makeMapping(
 899         IOMemoryDescriptor *    owner,
 900         task_t          intoTask,
 901         IOVirtualAddress        atAddress,
 902         IOOptionBits            options,
 903         IOByteCount             offset,
 904         IOByteCount             length );
 905
 906     virtual IOReturn doMap(
 907         vm_map_t                addressMap,
 908         IOVirtualAddress *      atAddress,
 909         IOOptionBits            options,
 910         IOByteCount             sourceOffset = 0,
 911         IOByteCount             length = 0 );
 912 };
 913
 914 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 915
 916 #endif /* !_IOMEMORYDESCRIPTOR_H */