iokit/IOKit/IOMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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  20  * Please see the License for the specific language governing rights and
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  24  */
  25 #ifndef _IOMEMORYDESCRIPTOR_H
  26 #define _IOMEMORYDESCRIPTOR_H
  27
  28 #include <IOKit/IOTypes.h>
  29 #include <libkern/c++/OSContainers.h>
  30
  31 struct IOPhysicalRange
  32 {
  33     IOPhysicalAddress   address;
  34     IOByteCount         length;
  35 };
  36
  37 class IOMemoryMap;
  38
  39 /*
  40  * Direction of transfer, with respect to the described memory.
  41  */
  42 enum IODirection
  43 {
  44     kIODirectionNone  = 0x0,    //                    same as VM_PROT_NONE
  45     kIODirectionIn    = 0x1,    // User land 'read',  same as VM_PROT_READ
  46     kIODirectionOut   = 0x2,    // User land 'write', same as VM_PROT_WRITE
  47     kIODirectionOutIn = kIODirectionIn | kIODirectionOut,
  48 };
  49
  50 /*! @class IOMemoryDescriptor : public OSObject
  51     @abstract An abstract base class defining common methods for describing physical or virtual memory.
  52     @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. */
  53
  54 class IOMemoryDescriptor : public OSObject
  55 {
  56     friend class _IOMemoryMap;
  57     friend class IOSubMemoryDescriptor;
  58
  59     OSDeclareDefaultStructors(IOMemoryDescriptor);
  60
  61 protected:
  62 /*! @struct ExpansionData
  63     @discussion This structure will be used to expand the capablilties of this class in the future.
  64     */
  65     struct ExpansionData {
  66         void *                          devicePager;
  67         unsigned int                    pagerContig:1;
  68         unsigned int                    unused:31;
  69         IOMemoryDescriptor *            memory;
  70     };
  71
  72 /*! @var reserved
  73     Reserved for future use.  (Internal use only)  */
  74     ExpansionData * reserved;
  75
  76 protected:
  77     OSSet *             _mappings;
  78     IOOptionBits        _flags;
  79     void *              _memEntry;
  80
  81     IODirection         _direction;        /* direction of transfer */
  82     IOByteCount         _length;           /* length of all ranges */
  83     IOOptionBits        _tag;
  84
  85 public:
  86
  87     virtual IOPhysicalAddress getSourceSegment( IOByteCount offset,
  88                                                 IOByteCount * length );
  89
  90 private:
  91     OSMetaClassDeclareReservedUsed(IOMemoryDescriptor, 0);
  92     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 1);
  93     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 2);
  94     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 3);
  95     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 4);
  96     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 5);
  97     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 6);
  98     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 7);
  99     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 8);
 100     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 9);
 101     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 10);
 102     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 11);
 103     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 12);
 104     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 13);
 105     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 14);
 106     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 15);
 107
 108 protected:
 109     virtual void free();
 110 public:
 111     static void initialize( void );
 112
 113 public:
 114 /*! @function withAddress
 115     @abstract Create an IOMemoryDescriptor to describe one virtual range of the kernel task.
 116     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the kernel map.
 117     @param address The virtual address of the first byte in the memory.
 118     @param withLength The length of memory.
 119     @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.
 120     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 121
 122     static IOMemoryDescriptor * withAddress(void *       address,
 123                                             IOByteCount  withLength,
 124                                             IODirection  withDirection);
 125
 126 /*! @function withAddress
 127     @abstract Create an IOMemoryDescriptor to describe one virtual range of the specified map.
 128     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the specified map.
 129     @param address The virtual address of the first byte in the memory.
 130     @param withLength The length of memory.
 131     @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.
 132     @param withTask The task the virtual ranges are mapped into.
 133     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 134
 135     static IOMemoryDescriptor * withAddress(vm_address_t address,
 136                                             IOByteCount  withLength,
 137                                             IODirection  withDirection,
 138                                             task_t       withTask);
 139
 140 /*! @function withPhysicalAddress
 141     @abstract Create an IOMemoryDescriptor to describe one physical range.
 142     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single physical memory range.
 143     @param address The physical address of the first byte in the memory.
 144     @param withLength The length of memory.
 145     @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.
 146     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 147
 148     static IOMemoryDescriptor * withPhysicalAddress(
 149                                 IOPhysicalAddress       address,
 150                                 IOByteCount             withLength,
 151                                 IODirection             withDirection );
 152
 153 /*! @function withRanges
 154     @abstract Create an IOMemoryDescriptor to describe one or more virtual ranges.
 155     @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.
 156     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 157     @param withCount The member count of the ranges array.
 158     @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.
 159     @param withTask The task each of the virtual ranges are mapped into.
 160     @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.
 161     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 162
 163      static IOMemoryDescriptor * withRanges(IOVirtualRange *    ranges,
 164                                             UInt32              withCount,
 165                                             IODirection         withDirection,
 166                                             task_t            withTask,
 167                                             bool                asReference = false);
 168
 169 /*! @function withPhysicalRanges
 170     @abstract Create an IOMemoryDescriptor to describe one or more physical ranges.
 171     @discussion  This method creates and initializes an IOMemoryDescriptor for memory consisting of an array of physical memory ranges.
 172     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 173     @param withCount The member count of the ranges array.
 174     @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.
 175     @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.
 176     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 177
 178     static IOMemoryDescriptor * withPhysicalRanges(
 179                                             IOPhysicalRange *   ranges,
 180                                             UInt32              withCount,
 181                                             IODirection         withDirection,
 182                                             bool                asReference = false);
 183
 184 /*! @function withSubRange
 185     @abstract Create an IOMemoryDescriptor to describe a subrange of an existing descriptor.
 186     @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.
 187     @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.
 188     @param offset A byte offset into the parent memory descriptor's memory.
 189     @param length The length of the subrange.
 190     @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.
 191     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 192
 193     static IOMemoryDescriptor * withSubRange(IOMemoryDescriptor *       of,
 194                                              IOByteCount                offset,
 195                                              IOByteCount                length,
 196                                              IODirection                withDirection);
 197
 198 /*! @function initWithAddress
 199     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the kernel task.
 200     @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.
 201     @param address The virtual address of the first byte in the memory.
 202     @param withLength The length of memory.
 203     @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.
 204     @result true on success, false on failure. */
 205
 206     virtual bool initWithAddress(void *       address,
 207                                  IOByteCount  withLength,
 208                                  IODirection  withDirection) = 0;
 209
 210 /*! @function initWithAddress
 211     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the specified map.
 212     @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.
 213     @param address The virtual address of the first byte in the memory.
 214     @param withLength The length of memory.
 215     @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.
 216     @param withTask The task the virtual ranges are mapped into.
 217     @result true on success, false on failure. */
 218
 219     virtual bool initWithAddress(vm_address_t address,
 220                                  IOByteCount  withLength,
 221                                  IODirection  withDirection,
 222                                  task_t       withTask) = 0;
 223
 224 /*! @function initWithPhysicalAddress
 225     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one physical range.
 226     @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.
 227     @param address The physical address of the first byte in the memory.
 228     @param withLength The length of memory.
 229     @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.
 230     @result true on success, false on failure. */
 231
 232     virtual bool initWithPhysicalAddress(
 233                                  IOPhysicalAddress      address,
 234                                  IOByteCount            withLength,
 235                                  IODirection            withDirection ) = 0;
 236
 237 /*! @function initWithRanges
 238     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more virtual ranges.
 239     @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.
 240     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 241     @param withCount The member count of the ranges array.
 242     @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.
 243     @param withTask The task each of the virtual ranges are mapped into.
 244     @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.
 245     @result true on success, false on failure. */
 246
 247     virtual bool initWithRanges(        IOVirtualRange * ranges,
 248                                         UInt32           withCount,
 249                                         IODirection      withDirection,
 250                                         task_t           withTask,
 251                                         bool             asReference = false) = 0;
 252
 253 /*! @function initWithPhysicalRanges
 254     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more physical ranges.
 255     @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.
 256     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 257     @param withCount The member count of the ranges array.
 258     @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.
 259     @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.
 260     @result true on success, false on failure. */
 261
 262     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 263                                         UInt32           withCount,
 264                                         IODirection      withDirection,
 265                                         bool             asReference = false) = 0;
 266
 267 /*! @function getDirection
 268     @abstract Accessor to get the direction the memory descriptor was created with.
 269     @discussion This method returns the direction the memory descriptor was created with.
 270     @result The direction. */
 271
 272     virtual IODirection getDirection() const;
 273
 274 /*! @function getLength
 275     @abstract Accessor to get the length of the memory descriptor (over all its ranges).
 276     @discussion This method returns the total length of the memory described by the descriptor, ie. the sum of its ranges' lengths.
 277     @result The byte count. */
 278
 279     virtual IOByteCount getLength() const;
 280
 281 /*! @function setTag
 282     @abstract Set the tag for the memory descriptor.
 283     @discussion This method sets the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 284     @param tag The tag. */
 285
 286     virtual void setTag( IOOptionBits tag );
 287
 288 /*! @function getTag
 289     @abstract Accessor to the retrieve the tag for the memory descriptor.
 290     @discussion This method returns the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 291     @result The tag. */
 292
 293     virtual IOOptionBits getTag( void );
 294
 295 /*! @function readBytes
 296     @abstract Copy data from the memory descriptor's buffer to the specified buffer.
 297     @discussion This method copies data from the memory descriptor's memory at the given offset, to the caller's buffer.
 298     @param offset A byte offset into the memory descriptor's memory.
 299     @param bytes The caller supplied buffer to copy the data to.
 300     @param withLength The length of the data to copy.
 301     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 302
 303     virtual IOByteCount readBytes(IOByteCount offset,
 304                                 void * bytes, IOByteCount withLength);
 305
 306 /*! @function writeBytes
 307     @abstract Copy data to the memory descriptor's buffer from the specified buffer.
 308     @discussion This method copies data to the memory descriptor's memory at the given offset, from the caller's buffer.
 309     @param offset A byte offset into the memory descriptor's memory.
 310     @param bytes The caller supplied buffer to copy the data from.
 311     @param withLength The length of the data to copy.
 312     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 313
 314     virtual IOByteCount writeBytes(IOByteCount offset,
 315                                 const void * bytes, IOByteCount withLength);
 316
 317 /*! @function getPhysicalSegment
 318     @abstract Break a memory descriptor into its physically contiguous segments.
 319     @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.
 320     @param offset A byte offset into the memory whose physical address to return.
 321     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 322     @result A physical address, or zero if the offset is beyond the length of the memory. */
 323
 324     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 325                                                  IOByteCount * length) = 0;
 326
 327 /*! @function getPhysicalAddress
 328     @abstract Return the physical address of the first byte in the memory.
 329     @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.
 330     @result A physical address. */
 331
 332     /* inline */ IOPhysicalAddress getPhysicalAddress();
 333         /* { return( getPhysicalSegment( 0, 0 )); } */
 334
 335     /* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
 336     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 337     /* DEPRECATED */                                    IOByteCount * length) = 0;
 338     /* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
 339
 340 /*! @function prepare
 341     @abstract Prepare the memory for an I/O transfer.
 342     @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.  This method needn't called for non-pageable memory.
 343     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 344     @result An IOReturn code. */
 345
 346     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) = 0;
 347
 348 /*! @function complete
 349     @abstract Complete processing of the memory after an I/O transfer finishes.
 350     @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.
 351     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 352     @result An IOReturn code. */
 353
 354     virtual IOReturn complete(IODirection forDirection = kIODirectionNone) = 0;
 355
 356     /*
 357      * Mapping functions.
 358      */
 359
 360 /*! @function map
 361     @abstract Maps a IOMemoryDescriptor into a task.
 362     @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.
 363     @param intoTask Sets the target task for the mapping. Pass kernel_task for the kernel address space.
 364     @param atAddress If a placed mapping is requested, atAddress specifies its address, and the kIOMapAnywhere should not be set. Otherwise, atAddress is ignored.
 365     @param options Mapping options are defined in IOTypes.h,<br>
 366         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>
 367         kIOMapDefaultCache to inhibit the cache in I/O areas, kIOMapCopybackCache in general purpose RAM.<br>
 368         kIOMapInhibitCache, kIOMapWriteThruCache, kIOMapCopybackCache to set the appropriate caching.<br>
 369         kIOMapReadOnly to allow only read only accesses to the memory - writes will cause and access fault.<br>
 370         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>
 371     @param offset Is a beginning offset into the IOMemoryDescriptor's memory where the mapping starts. Zero is the default to map all the memory.
 372     @param length Is the length of the mapping requested for a subset of the IOMemoryDescriptor. Zero is the default to map all the memory.
 373     @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. */
 374
 375     virtual IOMemoryMap *       map(
 376         task_t          intoTask,
 377         IOVirtualAddress        atAddress,
 378         IOOptionBits            options,
 379         IOByteCount             offset = 0,
 380         IOByteCount             length = 0 );
 381
 382 /*! @function map
 383     @abstract Maps a IOMemoryDescriptor into the kernel map.
 384     @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.
 385     @param options Mapping options as in the full version of the map method, with kIOMapAnywhere assumed.
 386     @result See the full version of the map method. */
 387
 388     virtual IOMemoryMap *       map(
 389         IOOptionBits            options = 0 );
 390
 391 /*! @function setMapping
 392     @abstract Establishes an already existing mapping.
 393     @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.
 394     @param task Address space in which the mapping exists.
 395     @param mapAddress Virtual address of the mapping.
 396     @param options Caching and read-only attributes of the mapping.
 397     @result A IOMemoryMap object created to represent the mapping. */
 398
 399     virtual IOMemoryMap *       setMapping(
 400         task_t          task,
 401         IOVirtualAddress        mapAddress,
 402         IOOptionBits            options = 0 );
 403
 404     // Following methods are private implementation
 405
 406     // make virtual
 407     IOReturn redirect( task_t safeTask, bool redirect );
 408
 409     IOReturn handleFault(
 410         void *                  pager,
 411         vm_map_t                addressMap,
 412         IOVirtualAddress        address,
 413         IOByteCount             sourceOffset,
 414         IOByteCount             length,
 415         IOOptionBits            options );
 416
 417 protected:
 418     virtual IOMemoryMap *       makeMapping(
 419         IOMemoryDescriptor *    owner,
 420         task_t          intoTask,
 421         IOVirtualAddress        atAddress,
 422         IOOptionBits            options,
 423         IOByteCount             offset,
 424         IOByteCount             length );
 425
 426     virtual void                addMapping(
 427         IOMemoryMap *           mapping );
 428
 429     virtual void                removeMapping(
 430         IOMemoryMap *           mapping );
 431
 432     virtual IOReturn doMap(
 433         vm_map_t                addressMap,
 434         IOVirtualAddress *      atAddress,
 435         IOOptionBits            options,
 436         IOByteCount             sourceOffset = 0,
 437         IOByteCount             length = 0 );
 438
 439     virtual IOReturn doUnmap(
 440         vm_map_t                addressMap,
 441         IOVirtualAddress        logical,
 442         IOByteCount             length );
 443 };
 444
 445 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 446
 447 /*! @class IOMemoryMap : public OSObject
 448     @abstract An abstract base class defining common methods for describing a memory mapping.
 449     @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. */
 450
 451 class IOMemoryMap : public OSObject
 452 {
 453     OSDeclareAbstractStructors(IOMemoryMap)
 454
 455 public:
 456 /*! @function getVirtualAddress
 457     @abstract Accessor to the virtual address of the first byte in the mapping.
 458     @discussion This method returns the virtual address of the first byte in the mapping.
 459     @result A virtual address. */
 460
 461     virtual IOVirtualAddress    getVirtualAddress() = 0;
 462
 463 /*! @function getPhysicalSegment
 464     @abstract Break a mapping into its physically contiguous segments.
 465     @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.
 466     @param offset A byte offset into the mapping whose physical address to return.
 467     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 468     @result A physical address, or zero if the offset is beyond the length of the mapping. */
 469
 470     virtual IOPhysicalAddress   getPhysicalSegment(IOByteCount offset,
 471                                                    IOByteCount * length) = 0;
 472
 473 /*! @function getPhysicalAddress
 474     @abstract Return the physical address of the first byte in the mapping.
 475     @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.
 476     @result A physical address. */
 477
 478     /* inline */ IOPhysicalAddress getPhysicalAddress();
 479         /* { return( getPhysicalSegment( 0, 0 )); } */
 480
 481 /*! @function getLength
 482     @abstract Accessor to the length of the mapping.
 483     @discussion This method returns the length of the mapping.
 484     @result A byte count. */
 485
 486     virtual IOByteCount         getLength() = 0;
 487
 488 /*! @function getAddressTask
 489     @abstract Accessor to the task of the mapping.
 490     @discussion This method returns the mach task the mapping exists in.
 491     @result A mach task_t. */
 492
 493     virtual task_t              getAddressTask() = 0;
 494
 495 /*! @function getMemoryDescriptor
 496     @abstract Accessor to the IOMemoryDescriptor the mapping was created from.
 497     @discussion This method returns the IOMemoryDescriptor the mapping was created from.
 498     @result An IOMemoryDescriptor reference, which is valid while the IOMemoryMap object is retained. It should not be released by the caller. */
 499
 500     virtual IOMemoryDescriptor * getMemoryDescriptor() = 0;
 501
 502 /*! @function getMapOptions
 503     @abstract Accessor to the options the mapping was created with.
 504     @discussion This method returns the options to IOMemoryDescriptor::map the mapping was created with.
 505     @result Options for the mapping, including cache settings. */
 506
 507     virtual IOOptionBits        getMapOptions() = 0;
 508
 509 /*! @function unmap
 510     @abstract Force the IOMemoryMap to unmap, without destroying the object.
 511     @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.
 512     @result An IOReturn code. */
 513
 514     virtual IOReturn            unmap() = 0;
 515
 516     virtual void                        taskDied() = 0;
 517 };
 518
 519 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 520
 521 // The following classes are private implementation of IOMemoryDescriptor - they
 522 // should not be referenced directly, just through the public API's in the
 523 // IOMemoryDescriptor class. For example, an IOGeneralMemoryDescriptor instance
 524 // might be created by IOMemoryDescriptor::withAddress(), but there should be
 525 // no need to reference as anything but a generic IOMemoryDescriptor *.
 526
 527 enum {
 528     kIOMemoryRequiresWire       = 0x00000001
 529 };
 530
 531 class IOGeneralMemoryDescriptor : public IOMemoryDescriptor
 532 {
 533     OSDeclareDefaultStructors(IOGeneralMemoryDescriptor);
 534
 535 protected:
 536     union {
 537     IOVirtualRange *    v;
 538     IOPhysicalRange *   p;
 539     }                   _ranges;            /* list of address ranges */
 540     unsigned            _rangesCount;       /* number of address ranges in list */
 541     bool                _rangesIsAllocated; /* is list allocated by us? */
 542
 543     task_t              _task;               /* task where all ranges are mapped to */
 544
 545     union {
 546     IOVirtualRange      v;
 547     IOPhysicalRange     p;
 548     }                   _singleRange;      /* storage space for a single range */
 549
 550     unsigned            _wireCount;        /* number of outstanding wires */
 551
 552     vm_address_t        _cachedVirtualAddress;  /* a cached virtual-to-physical */
 553     IOPhysicalAddress   _cachedPhysicalAddress; /*    mapping, for optimization */
 554
 555     bool                _initialized;      /* has superclass been initialized? */
 556
 557     virtual void free();
 558
 559 protected:
 560     /* DEPRECATED */ IOByteCount _position; /* absolute position over all ranges */
 561     /* DEPRECATED */ virtual void setPosition(IOByteCount position);
 562
 563 private:
 564     /* DEPRECATED */ unsigned    _positionAtIndex;  /* range #n in which position is now */
 565     /* DEPRECATED */ IOByteCount _positionAtOffset; /* relative position within range #n */
 566     OSData *_memoryEntries;
 567
 568     /* DEPRECATED */ vm_offset_t _kernPtrAligned;
 569     /* DEPRECATED */ unsigned    _kernPtrAtIndex;
 570     /* DEPRECATED */ IOByteCount  _kernSize;
 571     /* DEPRECATED */ virtual void mapIntoKernel(unsigned rangeIndex);
 572     /* DEPRECATED */ virtual void unmapFromKernel();
 573     inline vm_map_t getMapForTask( task_t task, vm_address_t address );
 574
 575 public:
 576     /*
 577      * IOMemoryDescriptor required methods
 578      */
 579
 580     virtual bool initWithAddress(void *       address,
 581                                  IOByteCount    withLength,
 582                                  IODirection  withDirection);
 583
 584     virtual bool initWithAddress(vm_address_t address,
 585                                  IOByteCount    withLength,
 586                                  IODirection  withDirection,
 587                                  task_t       withTask);
 588
 589     virtual bool initWithPhysicalAddress(
 590                                  IOPhysicalAddress      address,
 591                                  IOByteCount            withLength,
 592                                  IODirection            withDirection );
 593
 594     virtual bool initWithRanges(        IOVirtualRange * ranges,
 595                                         UInt32           withCount,
 596                                         IODirection      withDirection,
 597                                         task_t           withTask,
 598                                         bool             asReference = false);
 599
 600     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 601                                         UInt32           withCount,
 602                                         IODirection      withDirection,
 603                                         bool             asReference = false);
 604
 605     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 606                                                  IOByteCount * length);
 607
 608     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 609                                                IOByteCount * length);
 610
 611     /* DEPRECATED */ virtual void * getVirtualSegment(IOByteCount offset,
 612     /* DEPRECATED */                                    IOByteCount * length);
 613
 614     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 615
 616     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 617
 618     virtual IOReturn doMap(
 619         vm_map_t                addressMap,
 620         IOVirtualAddress *      atAddress,
 621         IOOptionBits            options,
 622         IOByteCount             sourceOffset = 0,
 623         IOByteCount             length = 0 );
 624
 625     virtual IOReturn doUnmap(
 626         vm_map_t                addressMap,
 627         IOVirtualAddress        logical,
 628         IOByteCount             length );
 629     virtual bool serialize(OSSerialize *s) const;
 630 };
 631
 632 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 633
 634 class IOSubMemoryDescriptor : public IOMemoryDescriptor
 635 {
 636     friend class IOMemoryDescriptor;
 637
 638     OSDeclareDefaultStructors(IOSubMemoryDescriptor);
 639
 640 protected:
 641     IOMemoryDescriptor * _parent;
 642     IOByteCount          _start;
 643
 644     virtual void free();
 645
 646     virtual bool initSubRange( IOMemoryDescriptor * parent,
 647                                 IOByteCount offset, IOByteCount length,
 648                                 IODirection withDirection );
 649
 650     virtual bool initWithAddress(void *       address,
 651                                  IOByteCount    withLength,
 652                                  IODirection  withDirection);
 653
 654     virtual bool initWithAddress(vm_address_t address,
 655                                  IOByteCount    withLength,
 656                                  IODirection  withDirection,
 657                                  task_t       withTask);
 658
 659     virtual bool initWithPhysicalAddress(
 660                                  IOPhysicalAddress      address,
 661                                  IOByteCount            withLength,
 662                                  IODirection            withDirection );
 663
 664     virtual bool initWithRanges(        IOVirtualRange * ranges,
 665                                         UInt32           withCount,
 666                                         IODirection      withDirection,
 667                                         task_t           withTask,
 668                                         bool             asReference = false);
 669
 670     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 671                                         UInt32           withCount,
 672                                         IODirection      withDirection,
 673                                         bool             asReference = false);
 674
 675     IOMemoryDescriptor::withAddress;
 676     IOMemoryDescriptor::withPhysicalAddress;
 677     IOMemoryDescriptor::withPhysicalRanges;
 678     IOMemoryDescriptor::withRanges;
 679     IOMemoryDescriptor::withSubRange;
 680
 681 public:
 682     /*
 683      * IOMemoryDescriptor required methods
 684      */
 685
 686     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 687                                                  IOByteCount * length);
 688
 689     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 690                                                IOByteCount * length);
 691
 692     virtual IOByteCount readBytes(IOByteCount offset,
 693                                 void * bytes, IOByteCount withLength);
 694
 695     virtual IOByteCount writeBytes(IOByteCount offset,
 696                                 const void * bytes, IOByteCount withLength);
 697
 698     virtual void * getVirtualSegment(IOByteCount offset,
 699                                         IOByteCount * length);
 700
 701     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 702
 703     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 704
 705     // make virtual
 706     IOReturn redirect( task_t safeTask, bool redirect );
 707
 708     virtual bool serialize(OSSerialize *s) const;
 709
 710 protected:
 711     virtual IOMemoryMap *       makeMapping(
 712         IOMemoryDescriptor *    owner,
 713         task_t          intoTask,
 714         IOVirtualAddress        atAddress,
 715         IOOptionBits            options,
 716         IOByteCount             offset,
 717         IOByteCount             length );
 718 };
 719
 720 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 721
 722 #endif /* !_IOMEMORYDESCRIPTOR_H */