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
   9  * License.  Please obtain a copy of the License at
  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
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 #ifndef _IOMEMORYDESCRIPTOR_H
  23 #define _IOMEMORYDESCRIPTOR_H
  24
  25 #include <IOKit/IOTypes.h>
  26 #include <libkern/c++/OSContainers.h>
  27
  28 struct IOPhysicalRange
  29 {
  30     IOPhysicalAddress   address;
  31     IOByteCount         length;
  32 };
  33
  34 class IOMemoryMap;
  35
  36 /*
  37  * Direction of transfer, with respect to the described memory.
  38  */
  39 enum IODirection
  40 {
  41     kIODirectionNone  = 0x0,    //                    same as VM_PROT_NONE
  42     kIODirectionIn    = 0x1,    // User land 'read',  same as VM_PROT_READ
  43     kIODirectionOut   = 0x2,    // User land 'write', same as VM_PROT_WRITE
  44     kIODirectionOutIn = kIODirectionIn | kIODirectionOut,
  45 };
  46
  47 /*! @class IOMemoryDescriptor : public OSObject
  48     @abstract An abstract base class defining common methods for describing physical or virtual memory.
  49     @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. */
  50
  51 class IOMemoryDescriptor : public OSObject
  52 {
  53     friend class _IOMemoryMap;
  54     friend class IOSubMemoryDescriptor;
  55
  56     OSDeclareDefaultStructors(IOMemoryDescriptor);
  57
  58 protected:
  59 /*! @struct ExpansionData
  60     @discussion This structure will be used to expand the capablilties of this class in the future.
  61     */
  62     struct ExpansionData { };
  63
  64 /*! @var reserved
  65     Reserved for future use.  (Internal use only)  */
  66     ExpansionData * reserved;
  67
  68 protected:
  69     OSSet *             _mappings;
  70     IOOptionBits        _flags;
  71     void *              _memEntry;
  72
  73     IODirection         _direction;        /* direction of transfer */
  74     IOByteCount         _length;           /* length of all ranges */
  75     IOOptionBits        _tag;
  76
  77 private:
  78     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 0);
  79     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 1);
  80     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 2);
  81     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 3);
  82     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 4);
  83     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 5);
  84     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 6);
  85     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 7);
  86     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 8);
  87     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 9);
  88     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 10);
  89     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 11);
  90     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 12);
  91     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 13);
  92     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 14);
  93     OSMetaClassDeclareReservedUnused(IOMemoryDescriptor, 15);
  94
  95 protected:
  96     virtual void free();
  97 public:
  98     static void initialize( void );
  99
 100 public:
 101 /*! @function withAddress
 102     @abstract Create an IOMemoryDescriptor to describe one virtual range of the kernel task.
 103     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the kernel map.
 104     @param address The virtual address of the first byte in the memory.
 105     @param withLength The length of memory.
 106     @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.
 107     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 108
 109     static IOMemoryDescriptor * withAddress(void *       address,
 110                                             IOByteCount  withLength,
 111                                             IODirection  withDirection);
 112
 113 /*! @function withAddress
 114     @abstract Create an IOMemoryDescriptor to describe one virtual range of the specified map.
 115     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single virtual memory range mapped into the specified map.
 116     @param address The virtual address of the first byte in the memory.
 117     @param withLength The length of memory.
 118     @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.
 119     @param withTask The task the virtual ranges are mapped into.
 120     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 121
 122     static IOMemoryDescriptor * withAddress(vm_address_t address,
 123                                             IOByteCount  withLength,
 124                                             IODirection  withDirection,
 125                                             task_t       withTask);
 126
 127 /*! @function withPhysicalAddress
 128     @abstract Create an IOMemoryDescriptor to describe one physical range.
 129     @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a single physical memory range.
 130     @param address The physical address of the first byte in the memory.
 131     @param withLength The length of memory.
 132     @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.
 133     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 134
 135     static IOMemoryDescriptor * withPhysicalAddress(
 136                                 IOPhysicalAddress       address,
 137                                 IOByteCount             withLength,
 138                                 IODirection             withDirection );
 139
 140 /*! @function withRanges
 141     @abstract Create an IOMemoryDescriptor to describe one or more virtual ranges.
 142     @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.
 143     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 144     @param withCount The member count of the ranges array.
 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     @param withTask The task each of the virtual ranges are mapped into.
 147     @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.
 148     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 149
 150      static IOMemoryDescriptor * withRanges(IOVirtualRange *    ranges,
 151                                             UInt32              withCount,
 152                                             IODirection         withDirection,
 153                                             task_t            withTask,
 154                                             bool                asReference = false);
 155
 156 /*! @function withPhysicalRanges
 157     @abstract Create an IOMemoryDescriptor to describe one or more physical ranges.
 158     @discussion  This method creates and initializes an IOMemoryDescriptor for memory consisting of an array of physical memory ranges.
 159     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 160     @param withCount The member count of the ranges array.
 161     @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.
 162     @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.
 163     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 164
 165     static IOMemoryDescriptor * withPhysicalRanges(
 166                                             IOPhysicalRange *   ranges,
 167                                             UInt32              withCount,
 168                                             IODirection         withDirection,
 169                                             bool                asReference = false);
 170
 171 /*! @function withSubRange
 172     @abstract Create an IOMemoryDescriptor to describe a subrange of an existing descriptor.
 173     @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.
 174     @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.
 175     @param offset A byte offset into the parent memory descriptor's memory.
 176     @param length The length of the subrange.
 177     @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.
 178     @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 179
 180     static IOMemoryDescriptor * withSubRange(IOMemoryDescriptor *       of,
 181                                              IOByteCount                offset,
 182                                              IOByteCount                length,
 183                                              IODirection                withDirection);
 184
 185 /*! @function initWithAddress
 186     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the kernel task.
 187     @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.
 188     @param address The virtual address of the first byte in the memory.
 189     @param withLength The length of memory.
 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.
 191     @result true on success, false on failure. */
 192
 193     virtual bool initWithAddress(void *       address,
 194                                  IOByteCount  withLength,
 195                                  IODirection  withDirection) = 0;
 196
 197 /*! @function initWithAddress
 198     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one virtual range of the specified map.
 199     @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.
 200     @param address The virtual address of the first byte in the memory.
 201     @param withLength The length of memory.
 202     @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.
 203     @param withTask The task the virtual ranges are mapped into.
 204     @result true on success, false on failure. */
 205
 206     virtual bool initWithAddress(vm_address_t address,
 207                                  IOByteCount  withLength,
 208                                  IODirection  withDirection,
 209                                  task_t       withTask) = 0;
 210
 211 /*! @function initWithPhysicalAddress
 212     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one physical range.
 213     @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.
 214     @param address The physical address of the first byte in the memory.
 215     @param withLength The length of memory.
 216     @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.
 217     @result true on success, false on failure. */
 218
 219     virtual bool initWithPhysicalAddress(
 220                                  IOPhysicalAddress      address,
 221                                  IOByteCount            withLength,
 222                                  IODirection            withDirection ) = 0;
 223
 224 /*! @function initWithRanges
 225     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more virtual ranges.
 226     @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.
 227     @param ranges An array of IOVirtualRange structures which specify the virtual ranges in the specified map which make up the memory to be described.
 228     @param withCount The member count of the ranges array.
 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     @param withTask The task each of the virtual ranges are mapped into.
 231     @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.
 232     @result true on success, false on failure. */
 233
 234     virtual bool initWithRanges(        IOVirtualRange * ranges,
 235                                         UInt32           withCount,
 236                                         IODirection      withDirection,
 237                                         task_t           withTask,
 238                                         bool             asReference = false) = 0;
 239
 240 /*! @function initWithPhysicalRanges
 241     @abstract Initialize or reinitialize an IOMemoryDescriptor to describe one or more physical ranges.
 242     @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.
 243     @param ranges An array of IOPhysicalRange structures which specify the physical ranges which make up the memory to be described.
 244     @param withCount The member count of the ranges array.
 245     @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
 246     @param 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.
 247     @result true on success, false on failure. */
 248
 249     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 250                                         UInt32           withCount,
 251                                         IODirection      withDirection,
 252                                         bool             asReference = false) = 0;
 253
 254 /*! @function getDirection
 255     @abstract Accessor to get the direction the memory descriptor was created with.
 256     @discussion This method returns the direction the memory descriptor was created with.
 257     @result The direction. */
 258
 259     virtual IODirection getDirection() const;
 260
 261 /*! @function getLength
 262     @abstract Accessor to get the length of the memory descriptor (over all its ranges).
 263     @discussion This method returns the total length of the memory described by the descriptor, ie. the sum of its ranges' lengths.
 264     @result The byte count. */
 265
 266     virtual IOByteCount getLength() const;
 267
 268 /*! @function setTag
 269     @abstract Set the tag for the memory descriptor.
 270     @discussion This method sets the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 271     @param tag The tag. */
 272
 273     virtual void setTag( IOOptionBits tag );
 274
 275 /*! @function getTag
 276     @abstract Accessor to the retrieve the tag for the memory descriptor.
 277     @discussion This method returns the tag for the memory descriptor. Tag bits are not interpreted by IOMemoryDescriptor.
 278     @result The tag. */
 279
 280     virtual IOOptionBits getTag( void );
 281
 282 /*! @function readBytes
 283     @abstract Copy data from the memory descriptor's buffer to the specified buffer.
 284     @discussion This method copies data from the memory descriptor's memory at the given offset, to the caller's buffer.
 285     @param offset A byte offset into the memory descriptor's memory.
 286     @param bytes The caller supplied buffer to copy the data to.
 287     @param withLength The length of the data to copy.
 288     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 289
 290     virtual IOByteCount readBytes(IOByteCount offset,
 291                                 void * bytes, IOByteCount withLength) = 0;
 292
 293 /*! @function writeBytes
 294     @abstract Copy data to the memory descriptor's buffer from the specified buffer.
 295     @discussion This method copies data to the memory descriptor's memory at the given offset, from the caller's buffer.
 296     @param offset A byte offset into the memory descriptor's memory.
 297     @param bytes The caller supplied buffer to copy the data from.
 298     @param withLength The length of the data to copy.
 299     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 300
 301     virtual IOByteCount writeBytes(IOByteCount offset,
 302                                 const void * bytes, IOByteCount withLength) = 0;
 303
 304 /*! @function getPhysicalSegment
 305     @abstract Break a memory descriptor into its physically contiguous segments.
 306     @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.
 307     @param offset A byte offset into the memory whose physical address to return.
 308     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 309     @result A physical address, or zero if the offset is beyond the length of the memory. */
 310
 311     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 312                                                  IOByteCount * length) = 0;
 313
 314 /*! @function getPhysicalAddress
 315     @abstract Return the physical address of the first byte in the memory.
 316     @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.
 317     @result A physical address. */
 318
 319     inline IOPhysicalAddress    getPhysicalAddress()
 320                                 { return( getPhysicalSegment( 0, 0 )); }
 321
 322     /*
 323      * getVirtualSegment:
 324      *
 325      * Get the virtual address of the buffer, relative to the given offset.
 326      * If the memory wasn't mapped into the caller's address space, it will be
 327      * mapped in now.   If the current position is at the end of the buffer, a
 328      * null is returned.
 329      */
 330     virtual void * getVirtualSegment(IOByteCount offset,
 331                                         IOByteCount * length) = 0;
 332
 333 /*! @function prepare
 334     @abstract Prepare the memory for an I/O transfer.
 335     @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.
 336     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 337     @result An IOReturn code. */
 338
 339     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) = 0;
 340
 341 /*! @function complete
 342     @abstract Complete processing of the memory after an I/O transfer finishes.
 343     @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.
 344     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 345     @result An IOReturn code. */
 346
 347     virtual IOReturn complete(IODirection forDirection = kIODirectionNone) = 0;
 348
 349     /*
 350      * Mapping functions.
 351      */
 352
 353 /*! @function map
 354     @abstract Maps a IOMemoryDescriptor into a task.
 355     @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.
 356     @param intoTask Sets the target task for the mapping. Pass kernel_task for the kernel address space.
 357     @param atAddress If a placed mapping is requested, atAddress specifies its address, and the kIOMapAnywhere should not be set. Otherwise, atAddress is ignored.
 358     @param options Mapping options are defined in IOTypes.h,<br>
 359         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>
 360         kIOMapDefaultCache to inhibit the cache in I/O areas, kIOMapCopybackCache in general purpose RAM.<br>
 361         kIOMapInhibitCache, kIOMapWriteThruCache, kIOMapCopybackCache to set the appropriate caching.<br>
 362         kIOMapReadOnly to allow only read only accesses to the memory - writes will cause and access fault.<br>
 363         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>
 364     @param offset Is a beginning offset into the IOMemoryDescriptor's memory where the mapping starts. Zero is the default to map all the memory.
 365     @param length Is the length of the mapping requested for a subset of the IOMemoryDescriptor. Zero is the default to map all the memory.
 366     @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. */
 367
 368     virtual IOMemoryMap *       map(
 369         task_t          intoTask,
 370         IOVirtualAddress        atAddress,
 371         IOOptionBits            options,
 372         IOByteCount             offset = 0,
 373         IOByteCount             length = 0 );
 374
 375 /*! @function map
 376     @abstract Maps a IOMemoryDescriptor into the kernel map.
 377     @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.
 378     @param options Mapping options as in the full version of the map method, with kIOMapAnywhere assumed.
 379     @result See the full version of the map method. */
 380
 381     virtual IOMemoryMap *       map(
 382         IOOptionBits            options = 0 );
 383
 384 /*! @function setMapping
 385     @abstract Establishes an already existing mapping.
 386     @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.
 387     @param task Address space in which the mapping exists.
 388     @param mapAddress Virtual address of the mapping.
 389     @param options Caching and read-only attributes of the mapping.
 390     @result A IOMemoryMap object created to represent the mapping. */
 391
 392     virtual IOMemoryMap *       setMapping(
 393         task_t          task,
 394         IOVirtualAddress        mapAddress,
 395         IOOptionBits            options = 0 );
 396
 397 protected:
 398     virtual IOMemoryMap *       makeMapping(
 399         IOMemoryDescriptor *    owner,
 400         task_t          intoTask,
 401         IOVirtualAddress        atAddress,
 402         IOOptionBits            options,
 403         IOByteCount             offset,
 404         IOByteCount             length );
 405
 406     virtual void                addMapping(
 407         IOMemoryMap *           mapping );
 408
 409     virtual void                removeMapping(
 410         IOMemoryMap *           mapping );
 411
 412     virtual IOReturn doMap(
 413         vm_map_t                addressMap,
 414         IOVirtualAddress *      atAddress,
 415         IOOptionBits            options,
 416         IOByteCount             sourceOffset = 0,
 417         IOByteCount             length = 0 );
 418
 419     virtual IOReturn doUnmap(
 420         vm_map_t                addressMap,
 421         IOVirtualAddress        logical,
 422         IOByteCount             length );
 423 };
 424
 425 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 426
 427 /*! @class IOMemoryMap : public OSObject
 428     @abstract An abstract base class defining common methods for describing a memory mapping.
 429     @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. */
 430
 431 class IOMemoryMap : public OSObject
 432 {
 433     OSDeclareAbstractStructors(IOMemoryMap)
 434
 435 public:
 436 /*! @function getVirtualAddress
 437     @abstract Accessor to the virtual address of the first byte in the mapping.
 438     @discussion This method returns the virtual address of the first byte in the mapping.
 439     @result A virtual address. */
 440
 441     virtual IOVirtualAddress    getVirtualAddress() = 0;
 442
 443 /*! @function getPhysicalSegment
 444     @abstract Break a mapping into its physically contiguous segments.
 445     @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.
 446     @param offset A byte offset into the mapping whose physical address to return.
 447     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 448     @result A physical address, or zero if the offset is beyond the length of the mapping. */
 449
 450     virtual IOPhysicalAddress   getPhysicalSegment(IOByteCount offset,
 451                                                    IOByteCount * length) = 0;
 452
 453 /*! @function getPhysicalAddress
 454     @abstract Return the physical address of the first byte in the mapping.
 455     @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.
 456     @result A physical address. */
 457
 458     inline IOPhysicalAddress    getPhysicalAddress()
 459                                 { return( getPhysicalSegment( 0, 0 )); }
 460
 461 /*! @function getLength
 462     @abstract Accessor to the length of the mapping.
 463     @discussion This method returns the length of the mapping.
 464     @result A byte count. */
 465
 466     virtual IOByteCount         getLength() = 0;
 467
 468 /*! @function getAddressTask
 469     @abstract Accessor to the task of the mapping.
 470     @discussion This method returns the mach task the mapping exists in.
 471     @result A mach task_t. */
 472
 473     virtual task_t              getAddressTask() = 0;
 474
 475 /*! @function getMemoryDescriptor
 476     @abstract Accessor to the IOMemoryDescriptor the mapping was created from.
 477     @discussion This method returns the IOMemoryDescriptor the mapping was created from.
 478     @result An IOMemoryDescriptor reference, which is valid while the IOMemoryMap object is retained. It should not be released by the caller. */
 479
 480     virtual IOMemoryDescriptor * getMemoryDescriptor() = 0;
 481
 482 /*! @function getMapOptions
 483     @abstract Accessor to the options the mapping was created with.
 484     @discussion This method returns the options to IOMemoryDescriptor::map the mapping was created with.
 485     @result Options for the mapping, including cache settings. */
 486
 487     virtual IOOptionBits        getMapOptions() = 0;
 488
 489 /*! @function unmap
 490     @abstract Force the IOMemoryMap to unmap, without destroying the object.
 491     @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.
 492     @result An IOReturn code. */
 493
 494     virtual IOReturn            unmap() = 0;
 495
 496     virtual void                        taskDied() = 0;
 497 };
 498
 499 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 500
 501 enum {
 502     kIOMemoryRequiresWire       = 0x00000001
 503 };
 504
 505 class IOGeneralMemoryDescriptor : public IOMemoryDescriptor
 506 {
 507     OSDeclareDefaultStructors(IOGeneralMemoryDescriptor);
 508
 509 protected:
 510     union {
 511     IOVirtualRange *    v;
 512     IOPhysicalRange *   p;
 513     }                   _ranges;            /* list of address ranges */
 514     unsigned            _rangesCount;       /* number of address ranges in list */
 515     bool                _rangesIsAllocated; /* is list allocated by us? */
 516
 517     task_t              _task;               /* task where all ranges are mapped to */
 518
 519     union {
 520     IOVirtualRange      v;
 521     IOPhysicalRange     p;
 522     }                   _singleRange;      /* storage space for a single range */
 523
 524     unsigned            _wireCount;        /* number of outstanding wires */
 525
 526     vm_address_t        _cachedVirtualAddress;  /* a cached virtual-to-physical */
 527     IOPhysicalAddress   _cachedPhysicalAddress; /*    mapping, for optimization */
 528
 529     bool                _initialized;      /* has superclass been initialized? */
 530
 531     virtual void free();
 532
 533 protected: /* (to be deprecated) */
 534     IOByteCount         _position;         /* absolute position over all ranges */
 535     virtual void setPosition(IOByteCount position);
 536
 537 private:
 538     unsigned            _positionAtIndex;  /* range #n in which position is now */
 539     IOByteCount         _positionAtOffset; /* relative position within range #n */
 540     OSData *_memoryEntries;
 541
 542     vm_offset_t _kernPtrAligned;
 543     unsigned    _kernPtrAtIndex;
 544     IOByteCount  _kernSize;
 545     virtual void mapIntoKernel(unsigned rangeIndex);
 546     virtual void unmapFromKernel();
 547     inline vm_map_t getMapForTask( task_t task, vm_address_t address );
 548
 549 public:
 550     /*
 551      * IOMemoryDescriptor required methods
 552      */
 553
 554     virtual bool initWithAddress(void *       address,
 555                                  IOByteCount    withLength,
 556                                  IODirection  withDirection);
 557
 558     virtual bool initWithAddress(vm_address_t address,
 559                                  IOByteCount    withLength,
 560                                  IODirection  withDirection,
 561                                  task_t       withTask);
 562
 563     virtual bool initWithPhysicalAddress(
 564                                  IOPhysicalAddress      address,
 565                                  IOByteCount            withLength,
 566                                  IODirection            withDirection );
 567
 568     virtual bool initWithRanges(        IOVirtualRange * ranges,
 569                                         UInt32           withCount,
 570                                         IODirection      withDirection,
 571                                         task_t           withTask,
 572                                         bool             asReference = false);
 573
 574     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 575                                         UInt32           withCount,
 576                                         IODirection      withDirection,
 577                                         bool             asReference = false);
 578
 579     virtual IOByteCount readBytes(IOByteCount offset,
 580                                 void * bytes, IOByteCount withLength);
 581
 582     virtual IOByteCount writeBytes(IOByteCount offset,
 583                                 const void * bytes, IOByteCount withLength);
 584
 585     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 586                                                  IOByteCount * length);
 587
 588     virtual void * getVirtualSegment(IOByteCount offset,
 589                                         IOByteCount * length);
 590
 591     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 592
 593     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 594
 595     virtual IOReturn doMap(
 596         vm_map_t                addressMap,
 597         IOVirtualAddress *      atAddress,
 598         IOOptionBits            options,
 599         IOByteCount             sourceOffset = 0,
 600         IOByteCount             length = 0 );
 601
 602     virtual IOReturn doUnmap(
 603         vm_map_t                addressMap,
 604         IOVirtualAddress        logical,
 605         IOByteCount             length );
 606 };
 607
 608 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 609
 610 class IOSubMemoryDescriptor : public IOMemoryDescriptor
 611 {
 612     friend IOMemoryDescriptor;
 613
 614     OSDeclareDefaultStructors(IOSubMemoryDescriptor);
 615
 616 protected:
 617     IOMemoryDescriptor * _parent;
 618     IOByteCount          _start;
 619
 620     virtual void free();
 621
 622     virtual bool initSubRange( IOMemoryDescriptor * parent,
 623                                 IOByteCount offset, IOByteCount length,
 624                                 IODirection withDirection );
 625
 626     virtual bool initWithAddress(void *       address,
 627                                  IOByteCount    withLength,
 628                                  IODirection  withDirection);
 629
 630     virtual bool initWithAddress(vm_address_t address,
 631                                  IOByteCount    withLength,
 632                                  IODirection  withDirection,
 633                                  task_t       withTask);
 634
 635     virtual bool initWithPhysicalAddress(
 636                                  IOPhysicalAddress      address,
 637                                  IOByteCount            withLength,
 638                                  IODirection            withDirection );
 639
 640     virtual bool initWithRanges(        IOVirtualRange * ranges,
 641                                         UInt32           withCount,
 642                                         IODirection      withDirection,
 643                                         task_t           withTask,
 644                                         bool             asReference = false);
 645
 646     virtual bool initWithPhysicalRanges(IOPhysicalRange * ranges,
 647                                         UInt32           withCount,
 648                                         IODirection      withDirection,
 649                                         bool             asReference = false);
 650
 651     IOMemoryDescriptor::withAddress;
 652     IOMemoryDescriptor::withPhysicalAddress;
 653     IOMemoryDescriptor::withPhysicalRanges;
 654     IOMemoryDescriptor::withRanges;
 655     IOMemoryDescriptor::withSubRange;
 656
 657 public:
 658     /*
 659      * IOMemoryDescriptor required methods
 660      */
 661
 662     virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
 663                                                  IOByteCount * length);
 664
 665     virtual IOByteCount readBytes(IOByteCount offset,
 666                                 void * bytes, IOByteCount withLength);
 667
 668     virtual IOByteCount writeBytes(IOByteCount offset,
 669                                 const void * bytes, IOByteCount withLength);
 670
 671     virtual void * getVirtualSegment(IOByteCount offset,
 672                                         IOByteCount * length);
 673
 674     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 675
 676     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 677
 678 protected:
 679     virtual IOMemoryMap *       makeMapping(
 680         IOMemoryDescriptor *    owner,
 681         task_t          intoTask,
 682         IOVirtualAddress        atAddress,
 683         IOOptionBits            options,
 684         IOByteCount             offset,
 685         IOByteCount             length );
 686 };
 687
 688 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 689
 690 #endif /* !_IOMEMORYDESCRIPTOR_H */