iokit/IOKit/IOMemoryDescriptor.h

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