iokit/IOKit/IOMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   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.
  11  *
  12  * This Original Code and all software distributed under the License are
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  21  */
  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 second withRanges 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     kIOMemoryTypeMask           = 0x000000f0,
  66
  67     kIOMemoryAsReference        = 0x00000100,
  68     kIOMemoryBufferPageable     = 0x00000400,
  69     kIOMemoryDontMap            = 0x00000800,
  70     kIOMemoryPersistent         = 0x00010000
  71 };
  72
  73 #define kIOMapperNone   ((IOMapper *) -1)
  74 #define kIOMapperSystem ((IOMapper *) 0)
  75
  76 /*! @class IOMemoryDescriptor : public OSObject
  77     @abstract An abstract base class defining common methods for describing physical or virtual memory.
  78     @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. */
  79
  80 class IOMemoryDescriptor : public OSObject
  81 {
  82     friend class _IOMemoryMap;
  83     friend class IOSubMemoryDescriptor;
  84
  85     OSDeclareDefaultStructors(IOMemoryDescriptor);
  86
  87 protected:
  88 /*! @struct ExpansionData
  89     @discussion This structure will be used to expand the capablilties of this class in the future.
  90     */
  91     struct ExpansionData {
  92         void *                          devicePager;
  93         unsigned int                    pagerContig:1;
  94         unsigned int                    unused:31;
  95         IOMemoryDescriptor *            memory;
  96     };
  97
  98 /*! @var reserved
  99     Reserved for future use.  (Internal use only)  */
 100     ExpansionData * reserved;
 101
 102 protected:
 103     OSSet *             _mappings;
 104     IOOptionBits        _flags;
 105     void *              _memEntry;
 106
 107     IODirection         _direction;        /* DEPRECATED: use _flags instead. direction of transfer */
 108     IOByteCount         _length;           /* length of all ranges */
 109     IOOptionBits        _tag;
 110
 111 public:
 112
 113 /*! @function getBackingID
 114     @abstract Get an unique identifier for the virtual memory systems backing memory object.
 115     @discussion For memory descriptors that are directly mapped by real memory, IOGeneralMemoryDescriptors that are also persistent (kIOMemoryPersistent) return the id of the backing vm object.  This returned value can be tested to see if 2 memory persistent memory descriptors share the same backing.  The call itself is fairly heavy weight and can only be applied to persistent memory descriptors so it is not generally useful.  This function is NOT virtual at the moment.  We may choose to make it virtual in the future however.
 116     @result 0 on non-persistent or non IOGeneralMemoryDescriptors, unique id if not. */
 117     // See implementation at end of file
 118     inline void * getBackingID() const;
 119
 120     virtual IOPhysicalAddress getSourceSegment( IOByteCount offset,
 121                                                 IOByteCount * length );
 122     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 0);
 123
 124 /*! @function initWithOptions
 125     @abstract Master initialiser for all variants of memory descriptors.  For a more complete description see IOMemoryDescriptor::withOptions.
 126     @discussion Note this function can be used to re-init a previously created memory descriptor.
 127     @result true on success, false on failure. */
 128     virtual bool initWithOptions(void *         buffers,
 129                                  UInt32         count,
 130                                  UInt32         offset,
 131                                  task_t         task,
 132                                  IOOptionBits   options,
 133                                  IOMapper *     mapper = 0);
 134     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 1);
 135
 136     virtual addr64_t IOMemoryDescriptor::getPhysicalSegment64( IOByteCount offset,
 137                                                                 IOByteCount * length );
 138     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 2);
 139
 140 private:
 141
 142     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 3);
 143     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 4);
 144     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 5);
 145     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 6);
 146     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 7);
 147     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 8);
 148     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 9);
 149     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 10);
 150     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 11);
 151     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 12);
 152     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 13);
 153     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 14);
 154     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 15);
 155
 156 protected:
 157     virtual void free();
 158 public:
 159     static void initialize( void );
 160
 161 public:
 162 /*! @function withAddress
 163     @abstract Create an IOMemoryDescriptor to describe one virtual range of the kernel task.
 164     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the kernel map.
 165     @param address The virtual address of the first byte in the memory.
 166     @param withLength The length of memory.
 167     @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.
 168     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 169
 170     static IOMemoryDescriptor * withAddress(void *       address,
 171                                             IOByteCount  withLength,
 172                                             IODirection  withDirection);
 173
 174 /*! @function withAddress
 175     @abstract Create an IOMemoryDescriptor to describe one virtual range of the specified map.
 176     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the specified map.
 177     @param address The virtual address of the first byte in the memory.
 178     @param withLength The length of memory.
 179     @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.
 180     @param withTask The task the virtual ranges are mapped into.
 181     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 182
 183     static IOMemoryDescriptor * withAddress(vm_address_t address,
 184                                             IOByteCount  withLength,
 185                                             IODirection  withDirection,
 186                                             task_t       withTask);
 187
 188 /*! @function withPhysicalAddress
 189     @abstract Create an IOMemoryDescriptor to describe one physical range.
 190     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single physical memory range.
 191     @param address The physical address of the first byte in the memory.
 192     @param withLength The length of memory.
 193     @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.
 194     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 195
 196     static IOMemoryDescriptor * withPhysicalAddress(
 197                                 IOPhysicalAddress       address,
 198                                 IOByteCount             withLength,
 199                                 IODirection             withDirection );
 200
 201 /*! @function withRanges
 202     @abstract Create an IOMemoryDescriptor to describe one or more virtual ranges.
 203     @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.
 204     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 205     @param withCount The member count of the ranges array.
 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     @param withTask The task each of the virtual ranges are mapped into.
 208     @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.
 209     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 210
 211      static IOMemoryDescriptor * withRanges(IOVirtualRange * ranges,
 212                                             UInt32           withCount,
 213                                             IODirection      withDirection,
 214                                             task_t           withTask,
 215                                             bool             asReference = false);
 216
 217 /*! @function withOptions
 218     @abstract Master initialiser for all variants of memory descriptors.
 219     @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.
 220
 221
 222     @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.
 223
 224     @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.
 225
 226     @param offset Only used when options:type = UPL, in which case this field contains an offset for the memory within the buffers upl.
 227
 228     @param task Only used options:type = Virtual, The task each of the virtual ranges are mapped into.
 229
 230     @param options
 231         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.
 232         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.
 233         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.
 234         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.
 235         kIOMemoryNoAutoPrepare  Indicates that the temporary AutoPrepare of kernel_task memory should not be performed.
 236
 237     @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.
 238
 239     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 240
 241     static IOMemoryDescriptor *withOptions(void *       buffers,
 242                                            UInt32       count,
 243                                            UInt32       offset,
 244                                            task_t       task,
 245                                            IOOptionBits options,
 246                                            IOMapper *   mapper = 0);
 247
 248 /*! @function withPhysicalRanges
 249     @abstract Create an IOMemoryDescriptor to describe one or more physical ranges.
 250     @discussion  This method creates and initializes an IOMemoryDescriptor for memory consisting of an array of physical memory ranges.
 251     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 252     @param withCount The member count of the ranges array.
 253     @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.
 254     @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.
 255     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 256
 257     static IOMemoryDescriptor * withPhysicalRanges(
 258                                             IOPhysicalRange *   ranges,
 259                                             UInt32              withCount,
 260                                             IODirection         withDirection,
 261                                             bool                asReference = false);
 262
 263 /*! @function withSubRange
 264     @abstract Create an IOMemoryDescriptor to describe a subrange of an existing descriptor.
 265     @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.
 266     @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.
 267     @param offset A byte offset into the parent memory descriptor's memory.
 268     @param length The length of the subrange.
 269     @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.
 270     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 271
 272     static IOMemoryDescriptor * withSubRange(IOMemoryDescriptor *of,
 273                                              IOByteCount offset,
 274                                              IOByteCount length,
 275                                              IODirection withDirection);
 276
 277 /*! @function initWithAddress
 278     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the kernel task.
 279     @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.
 280     @param address The virtual address of the first byte in the memory.
 281     @param withLength The length of memory.
 282     @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.
 283     @result true on success, false on failure. */
 284
 285     virtual bool initWithAddress(void *       address,
 286                                  IOByteCount  withLength,
 287                                  IODirection  withDirection) = 0;
 288
 289 /*! @function initWithAddress
 290     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the specified map.
 291     @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.
 292     @param address The virtual address of the first byte in the memory.
 293     @param withLength The length of memory.
 294     @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.
 295     @param withTask The task the virtual ranges are mapped into.
 296     @result true on success, false on failure. */
 297
 298     virtual bool initWithAddress(vm_address_t address,
 299                                  IOByteCount  withLength,
 300                                  IODirection  withDirection,
 301                                  task_t       withTask) = 0;
 302
 303 /*! @function initWithPhysicalAddress
 304     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one physical range.
 305     @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.
 306     @param address The physical address of the first byte in the memory.
 307     @param withLength The length of memory.
 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.
 309     @result true on success, false on failure. */
 310
 311     virtual bool initWithPhysicalAddress(
 312                                  IOPhysicalAddress      address,
 313                                  IOByteCount            withLength,
 314                                  IODirection            withDirection ) = 0;
 315
 316 /*! @function initWithRanges
 317     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more virtual ranges.
 318     @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.
 319     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 320     @param withCount The member count of the ranges array.
 321     @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.
 322     @param withTask The task each of the virtual ranges are mapped into.
 323     @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.
 324     @result true on success, false on failure. */
 325
 326     virtual bool initWithRanges(IOVirtualRange * ranges,
 327                                 UInt32           withCount,
 328                                 IODirection      withDirection,
 329                                 task_t           withTask,
 330                                 bool             asReference = false) = 0;
 331
 332 /*! @function initWithPhysicalRanges
 333     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more physical ranges.
 334     @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.
 335     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 336     @param withCount The member count of the ranges array.
 337     @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.
 338     @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.
 339     @result true on success, false on failure. */
 340
 341     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 342                                         UInt32           withCount,
 343                                         IODirection      withDirection,
 344                                         bool             asReference = false) = 0;
 345
 346 /*! @function getDirection
 347     @abstract Accessor to get the direction the memory descriptor was created with.
 348     @discussion This method returns the direction the memory descriptor was created with.
 349     @result The direction. */
 350
 351     virtual IODirection getDirection() const;
 352
 353 /*! @function getLength
 354     @abstract Accessor to get the length of the memory descriptor (over all its ranges).
 355     @discussion This method returns the total length of the memory described by the descriptor, ie. the sum of its ranges' lengths.
 356     @result The byte count. */
 357
 358     virtual IOByteCount getLength() const;
 359
 360 /*! @function setTag
 361     @abstract Set the tag for the memory descriptor.
 362     @discussion This method sets the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 363     @param tag The tag. */
 364
 365     virtual void setTag( IOOptionBits tag );
 366
 367 /*! @function getTag
 368     @abstract Accessor to the retrieve the tag for the memory descriptor.
 369     @discussion This method returns the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 370     @result The tag. */
 371
 372     virtual IOOptionBits getTag( void );
 373
 374 /*! @function readBytes
 375     @abstract Copy data from the memory descriptor's buffer to the specified buffer.
 376     @discussion This method copies data from the memory descriptor's memory at the given offset, to the caller's buffer.
 377     @param offset A byte offset into the memory descriptor's memory.
 378     @param bytes The caller supplied buffer to copy the data to.
 379     @param withLength The length of the data to copy.
 380     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 381
 382     virtual IOByteCount readBytes(IOByteCount offset,
 383                                 void * bytes, IOByteCount withLength);
 384
 385 /*! @function writeBytes
 386     @abstract Copy data to the memory descriptor's buffer from the specified buffer.
 387     @discussion This method copies data to the memory descriptor's memory at the given offset, from the caller's buffer.
 388     @param offset A byte offset into the memory descriptor's memory.
 389     @param bytes The caller supplied buffer to copy the data from.
 390     @param withLength The length of the data to copy.
 391     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 392
 393     virtual IOByteCount writeBytes(IOByteCount offset,
 394                                 const void * bytes, IOByteCount withLength);
 395
 396 /*! @function getPhysicalSegment
 397     @abstract Break a memory descriptor into its physically contiguous segments.
 398     @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.
 399     @param offset A byte offset into the memory whose physical address to return.
 400     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 401     @result A physical address, or zero if the offset is beyond the length of the memory. */
 402
 403     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 404                                                  IOByteCount * length) = 0;
 405
 406 /*! @function getPhysicalAddress
 407     @abstract Return the physical address of the first byte in the memory.
 408     @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.
 409     @result A physical address. */
 410
 411     /* inline */ IOPhysicalAddress getPhysicalAddress();
 412         /* { return( getPhysicalSegment( 0, 0 )); } */
 413
 414     /* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
 415     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 416     /* DEPRECATED */                                    IOByteCount * length) = 0;
 417     /* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
 418
 419 /*! @function prepare
 420     @abstract Prepare the memory for an I/O transfer.
 421     @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.
 422     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 423     @result An IOReturn code. */
 424
 425     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) = 0;
 426
 427 /*! @function complete
 428     @abstract Complete processing of the memory after an I/O transfer finishes.
 429     @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.
 430     @param forDirection DEPRECATED The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 431     @result An IOReturn code. */
 432
 433     virtual IOReturn complete(IODirection forDirection = kIODirectionNone) = 0;
 434
 435     /*
 436      * Mapping functions.
 437      */
 438
 439 /*! @function map
 440     @abstract Maps a IOMemoryDescriptor into a task.
 441     @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.
 442     @param intoTask Sets the target task for the mapping. Pass kernel_task for the kernel address space.
 443     @param atAddress If a placed mapping is requested, atAddress specifies its address, and the kIOMapAnywhere should not be set. Otherwise, atAddress is ignored.
 444     @param options Mapping options are defined in IOTypes.h,<br>
 445         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>
 446         kIOMapDefaultCache to inhibit the cache in I/O areas, kIOMapCopybackCache in general purpose RAM.<br>
 447         kIOMapInhibitCache, kIOMapWriteThruCache, kIOMapCopybackCache to set the appropriate caching.<br>
 448         kIOMapReadOnly to allow only read only accesses to the memory - writes will cause and access fault.<br>
 449         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>
 450     @param offset Is a beginning offset into the IOMemoryDescriptor's memory where the mapping starts. Zero is the default to map all the memory.
 451     @param length Is the length of the mapping requested for a subset of the IOMemoryDescriptor. Zero is the default to map all the memory.
 452     @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. */
 453
 454     virtual IOMemoryMap *       map(
 455         task_t          intoTask,
 456         IOVirtualAddress        atAddress,
 457         IOOptionBits            options,
 458         IOByteCount             offset = 0,
 459         IOByteCount             length = 0 );
 460
 461 /*! @function map
 462     @abstract Maps a IOMemoryDescriptor into the kernel map.
 463     @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.
 464     @param options Mapping options as in the full version of the map method, with kIOMapAnywhere assumed.
 465     @result See the full version of the map method. */
 466
 467     virtual IOMemoryMap *       map(
 468         IOOptionBits            options = 0 );
 469
 470 /*! @function setMapping
 471     @abstract Establishes an already existing mapping.
 472     @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.
 473     @param task Address space in which the mapping exists.
 474     @param mapAddress Virtual address of the mapping.
 475     @param options Caching and read-only attributes of the mapping.
 476     @result A IOMemoryMap object created to represent the mapping. */
 477
 478     virtual IOMemoryMap *       setMapping(
 479         task_t          task,
 480         IOVirtualAddress        mapAddress,
 481         IOOptionBits            options = 0 );
 482
 483     // Following methods are private implementation
 484
 485     // make virtual
 486     IOReturn redirect( task_t safeTask, bool redirect );
 487
 488     IOReturn handleFault(
 489         void *                  pager,
 490         vm_map_t                addressMap,
 491         IOVirtualAddress        address,
 492         IOByteCount             sourceOffset,
 493         IOByteCount             length,
 494         IOOptionBits            options );
 495
 496 protected:
 497     virtual IOMemoryMap *       makeMapping(
 498         IOMemoryDescriptor *    owner,
 499         task_t          intoTask,
 500         IOVirtualAddress        atAddress,
 501         IOOptionBits            options,
 502         IOByteCount             offset,
 503         IOByteCount             length );
 504
 505     virtual void                addMapping(
 506         IOMemoryMap *           mapping );
 507
 508     virtual void                removeMapping(
 509         IOMemoryMap *           mapping );
 510
 511     virtual IOReturn doMap(
 512         vm_map_t                addressMap,
 513         IOVirtualAddress *      atAddress,
 514         IOOptionBits            options,
 515         IOByteCount             sourceOffset = 0,
 516         IOByteCount             length = 0 );
 517
 518     virtual IOReturn doUnmap(
 519         vm_map_t                addressMap,
 520         IOVirtualAddress        logical,
 521         IOByteCount             length );
 522 };
 523
 524 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 525
 526 /*! @class IOMemoryMap : public OSObject
 527     @abstract An abstract base class defining common methods for describing a memory mapping.
 528     @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. */
 529
 530 class IOMemoryMap : public OSObject
 531 {
 532     OSDeclareAbstractStructors(IOMemoryMap)
 533
 534 public:
 535 /*! @function getVirtualAddress
 536     @abstract Accessor to the virtual address of the first byte in the mapping.
 537     @discussion This method returns the virtual address of the first byte in the mapping.
 538     @result A virtual address. */
 539
 540     virtual IOVirtualAddress    getVirtualAddress() = 0;
 541
 542 /*! @function getPhysicalSegment
 543     @abstract Break a mapping into its physically contiguous segments.
 544     @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.
 545     @param offset A byte offset into the mapping whose physical address to return.
 546     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 547     @result A physical address, or zero if the offset is beyond the length of the mapping. */
 548
 549     virtual IOPhysicalAddress   getPhysicalSegment(IOByteCount offset,
 550                                                    IOByteCount * length) = 0;
 551
 552 /*! @function getPhysicalAddress
 553     @abstract Return the physical address of the first byte in the mapping.
 554     @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.
 555     @result A physical address. */
 556
 557     /* inline */ IOPhysicalAddress getPhysicalAddress();
 558         /* { return( getPhysicalSegment( 0, 0 )); } */
 559
 560 /*! @function getLength
 561     @abstract Accessor to the length of the mapping.
 562     @discussion This method returns the length of the mapping.
 563     @result A byte count. */
 564
 565     virtual IOByteCount         getLength() = 0;
 566
 567 /*! @function getAddressTask
 568     @abstract Accessor to the task of the mapping.
 569     @discussion This method returns the mach task the mapping exists in.
 570     @result A mach task_t. */
 571
 572     virtual task_t              getAddressTask() = 0;
 573
 574 /*! @function getMemoryDescriptor
 575     @abstract Accessor to the IOMemoryDescriptor the mapping was created from.
 576     @discussion This method returns the IOMemoryDescriptor the mapping was created from.
 577     @result An IOMemoryDescriptor reference, which is valid while the IOMemoryMap object is retained. It should not be released by the caller. */
 578
 579     virtual IOMemoryDescriptor * getMemoryDescriptor() = 0;
 580
 581 /*! @function getMapOptions
 582     @abstract Accessor to the options the mapping was created with.
 583     @discussion This method returns the options to IOMemoryDescriptor::map the mapping was created with.
 584     @result Options for the mapping, including cache settings. */
 585
 586     virtual IOOptionBits        getMapOptions() = 0;
 587
 588 /*! @function unmap
 589     @abstract Force the IOMemoryMap to unmap, without destroying the object.
 590     @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.
 591     @result An IOReturn code. */
 592
 593     virtual IOReturn            unmap() = 0;
 594
 595     virtual void                taskDied() = 0;
 596 };
 597
 598 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 599
 600 // The following classes are private implementation of IOMemoryDescriptor - they
 601 // should not be referenced directly, just through the public API's in the
 602 // IOMemoryDescriptor class. For example, an IOGeneralMemoryDescriptor instance
 603 // might be created by IOMemoryDescriptor::withAddress(), but there should be
 604 // no need to reference as anything but a generic IOMemoryDescriptor *.
 605
 606 // Also these flags should not overlap with the options to
 607 //      IOMemoryDescriptor::initWithRanges(... IOOptionsBits options);
 608
 609 enum {
 610     kIOMemoryPreparedReadOnly   = 0x00008000,
 611 };
 612
 613 class IOGeneralMemoryDescriptor : public IOMemoryDescriptor
 614 {
 615     OSDeclareDefaultStructors(IOGeneralMemoryDescriptor);
 616
 617 protected:
 618     union {
 619         IOVirtualRange *  v;
 620         IOPhysicalRange * p;
 621     }                   _ranges;            /* list of address ranges */
 622     unsigned            _rangesCount;       /* number of address ranges in list */
 623     bool                _rangesIsAllocated; /* is list allocated by us? */
 624
 625     task_t              _task;               /* task where all ranges are mapped to */
 626
 627     union {
 628         IOVirtualRange  v;
 629         IOPhysicalRange p;
 630     }                   _singleRange;      /* storage space for a single range */
 631
 632     unsigned            _wireCount;        /* number of outstanding wires */
 633
 634     /* DEPRECATED */ vm_address_t _cachedVirtualAddress;  /* a cached virtual-to-physical */
 635
 636     /* DEPRECATED */ IOPhysicalAddress  _cachedPhysicalAddress;
 637
 638     bool                _initialized;      /* has superclass been initialized? */
 639
 640     virtual void free();
 641
 642
 643 private:
 644     // Internal API may be made virtual at some time in the future.
 645     IOReturn wireVirtual(IODirection forDirection);
 646
 647     /* DEPRECATED */ IOByteCount _position; /* absolute position over all ranges */
 648     /* DEPRECATED */ virtual void setPosition(IOByteCount position);
 649
 650 /*
 651  * DEPRECATED IOByteCount _positionAtIndex; // relative position within range #n
 652  *
 653  * Re-use the _positionAtIndex as a count of the number of pages in
 654  * this memory descriptor.  Convieniently vm_address_t is an unsigned integer
 655  * type so I can get away without having to change the type.
 656  */
 657     unsigned int                _pages;
 658
 659 /* DEPRECATED */ unsigned    _positionAtOffset;  //range #n in which position is now
 660
 661     OSData *_memoryEntries;
 662
 663     /* DEPRECATED */ vm_offset_t _kernPtrAligned;
 664     /* DEPRECATED */ unsigned    _kernPtrAtIndex;
 665     /* DEPRECATED */ IOByteCount  _kernSize;
 666
 667     /* DEPRECATED */ virtual void mapIntoKernel(unsigned rangeIndex);
 668     /* DEPRECATED */ virtual void unmapFromKernel();
 669
 670 public:
 671     /*
 672      * IOMemoryDescriptor required methods
 673      */
 674
 675 /*! @function getBackingID
 676     @abstract Returns the vm systems unique id for the memory backing this IOGeneralMemoryDescriptor.  See IOMemoryDescriptor::getBackingID for details.
 677     @result 0 on non-persistent or non IOGeneralMemoryDescriptors, unique id if not. */
 678     void * getBackingID() const;
 679
 680     // Master initaliser
 681     virtual bool initWithOptions(void *         buffers,
 682                                  UInt32         count,
 683                                  UInt32         offset,
 684                                  task_t         task,
 685                                  IOOptionBits   options,
 686                                  IOMapper *     mapper = 0);
 687
 688     // Secondary initialisers
 689     virtual bool initWithAddress(void *         address,
 690                                  IOByteCount    withLength,
 691                                  IODirection    withDirection);
 692
 693     virtual bool initWithAddress(vm_address_t   address,
 694                                  IOByteCount    withLength,
 695                                  IODirection    withDirection,
 696                                  task_t         withTask);
 697
 698     virtual bool initWithPhysicalAddress(
 699                                  IOPhysicalAddress      address,
 700                                  IOByteCount            withLength,
 701                                  IODirection            withDirection );
 702
 703     virtual bool initWithRanges(        IOVirtualRange * ranges,
 704                                         UInt32           withCount,
 705                                         IODirection      withDirection,
 706                                         task_t           withTask,
 707                                         bool             asReference = false);
 708
 709     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 710                                         UInt32           withCount,
 711                                         IODirection      withDirection,
 712                                         bool             asReference = false);
 713
 714     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 715                                                  IOByteCount * length);
 716
 717     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 718                                                IOByteCount * length);
 719
 720     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 721     /* DEPRECATED */                                    IOByteCount * length);
 722
 723     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 724
 725     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 726
 727     virtual IOReturn doMap(
 728         vm_map_t                addressMap,
 729         IOVirtualAddress *      atAddress,
 730         IOOptionBits            options,
 731         IOByteCount             sourceOffset = 0,
 732         IOByteCount             length = 0 );
 733
 734     virtual IOReturn doUnmap(
 735         vm_map_t                addressMap,
 736         IOVirtualAddress        logical,
 737         IOByteCount             length );
 738     virtual bool serialize(OSSerialize *s) const;
 739 };
 740
 741 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 742
 743 class IOSubMemoryDescriptor : public IOMemoryDescriptor
 744 {
 745     friend class IOMemoryDescriptor;
 746
 747     OSDeclareDefaultStructors(IOSubMemoryDescriptor);
 748
 749 protected:
 750     IOMemoryDescriptor * _parent;
 751     IOByteCount          _start;
 752
 753     virtual void free();
 754
 755     virtual bool initWithAddress(void *       address,
 756                                  IOByteCount    withLength,
 757                                  IODirection  withDirection);
 758
 759     virtual bool initWithAddress(vm_address_t address,
 760                                  IOByteCount    withLength,
 761                                  IODirection  withDirection,
 762                                  task_t       withTask);
 763
 764     virtual bool initWithPhysicalAddress(
 765                                  IOPhysicalAddress      address,
 766                                  IOByteCount            withLength,
 767                                  IODirection            withDirection );
 768
 769     virtual bool initWithRanges(        IOVirtualRange * ranges,
 770                                         UInt32           withCount,
 771                                         IODirection      withDirection,
 772                                         task_t           withTask,
 773                                         bool             asReference = false);
 774
 775     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 776                                         UInt32           withCount,
 777                                         IODirection      withDirection,
 778                                         bool             asReference = false);
 779
 780     IOMemoryDescriptor::withAddress;
 781     IOMemoryDescriptor::withPhysicalAddress;
 782     IOMemoryDescriptor::withPhysicalRanges;
 783     IOMemoryDescriptor::withRanges;
 784     IOMemoryDescriptor::withSubRange;
 785
 786 public:
 787     /*
 788      * Initialize or reinitialize an IOSubMemoryDescriptor to describe
 789      * a subrange of an existing descriptor.
 790      *
 791      * An IOSubMemoryDescriptor can be re-used by calling initSubRange
 792      * again on an existing instance -- note that this behavior is not
 793      * commonly supported in other IOKit classes, although it is here.
 794      */
 795     virtual bool initSubRange( IOMemoryDescriptor * parent,
 796                                 IOByteCount offset, IOByteCount length,
 797                                 IODirection withDirection );
 798
 799     /*
 800      * IOMemoryDescriptor required methods
 801      */
 802
 803     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 804                                                  IOByteCount * length);
 805
 806     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 807                                                IOByteCount * length);
 808
 809     virtual IOByteCount readBytes(IOByteCount offset,
 810                                 void * bytes, IOByteCount withLength);
 811
 812     virtual IOByteCount writeBytes(IOByteCount offset,
 813                                 const void * bytes, IOByteCount withLength);
 814
 815     virtual void * getVirtualSegment(IOByteCount offset,
 816                                         IOByteCount * length);
 817
 818     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 819
 820     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 821
 822     // make virtual
 823     IOReturn redirect( task_t safeTask, bool redirect );
 824
 825     virtual bool serialize(OSSerialize *s) const;
 826
 827 protected:
 828     virtual IOMemoryMap *       makeMapping(
 829         IOMemoryDescriptor *    owner,
 830         task_t          intoTask,
 831         IOVirtualAddress        atAddress,
 832         IOOptionBits            options,
 833         IOByteCount             offset,
 834         IOByteCount             length );
 835 };
 836
 837 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 838
 839 // Implementation of inline functions
 840 void * IOMemoryDescriptor::getBackingID() const
 841 {
 842     const IOGeneralMemoryDescriptor *genMD = (const IOGeneralMemoryDescriptor *)
 843         OSDynamicCast(IOGeneralMemoryDescriptor, this);
 844
 845     if (genMD)
 846         return genMD->getBackingID();
 847     else
 848         return 0;
 849 }
 850
 851 #endif /* !_IOMEMORYDESCRIPTOR_H */