iokit/Kernel/IOSubMemoryDescriptor.cpp

   1 /*
   2  * Copyright (c) 1998-2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <IOKit/IOSubMemoryDescriptor.h>
  30
  31 #include "IOKitKernelInternal.h"
  32
  33 #define super IOMemoryDescriptor
  34
  35 OSDefineMetaClassAndStructors(IOSubMemoryDescriptor, IOMemoryDescriptor)
  36
  37 IOReturn
  38 IOSubMemoryDescriptor::redirect( task_t safeTask, bool doRedirect )
  39 {
  40 #ifdef __LP64__
  41         super::redirect( safeTask, doRedirect );
  42 #endif /* __LP64__ */
  43         return _parent->redirect( safeTask, doRedirect );
  44 }
  45
  46 IOSubMemoryDescriptor *
  47 IOSubMemoryDescriptor::withSubRange(IOMemoryDescriptor *        of,
  48     IOByteCount             offset,
  49     IOByteCount             length,
  50     IOOptionBits            options)
  51 {
  52         IOSubMemoryDescriptor *self = new IOSubMemoryDescriptor;
  53
  54         if (self && !self->initSubRange(of, offset, length, (IODirection) options)) {
  55                 self->release();
  56                 self = 0;
  57         }
  58         return self;
  59 }
  60
  61 bool
  62 IOSubMemoryDescriptor::initSubRange( IOMemoryDescriptor * parent,
  63     IOByteCount offset, IOByteCount length,
  64     IODirection direction )
  65 {
  66         if (parent && ((offset + length) > parent->getLength())) {
  67                 return false;
  68         }
  69
  70         /*
  71          * We can check the _parent instance variable before having ever set it
  72          * to an initial value because I/O Kit guarantees that all our instance
  73          * variables are zeroed on an object's allocation.
  74          */
  75
  76         if (!_parent) {
  77                 if (!super::init()) {
  78                         return false;
  79                 }
  80         } else {
  81                 /*
  82                  * An existing memory descriptor is being retargeted to
  83                  * point to somewhere else.  Clean up our present state.
  84                  */
  85
  86                 _parent->release();
  87         }
  88
  89         if (parent) {
  90                 parent->retain();
  91                 _tag    = parent->getTag();
  92         } else {
  93                 _tag    = 0;
  94         }
  95         _parent     = parent;
  96         _start      = offset;
  97         _length     = length;
  98         _flags      = direction;
  99         _flags |= kIOMemoryThreadSafe;
 100
 101 #ifndef __LP64__
 102         _direction  = (IODirection) (_flags & kIOMemoryDirectionMask);
 103 #endif /* !__LP64__ */
 104
 105         return true;
 106 }
 107
 108 void
 109 IOSubMemoryDescriptor::free( void )
 110 {
 111         if (_parent) {
 112                 _parent->release();
 113         }
 114
 115         super::free();
 116 }
 117
 118 addr64_t
 119 IOSubMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount * length, IOOptionBits options)
 120 {
 121         addr64_t    address;
 122         IOByteCount actualLength;
 123
 124         assert(offset <= _length);
 125
 126         if (length) {
 127                 *length = 0;
 128         }
 129
 130         if (offset >= _length) {
 131                 return 0;
 132         }
 133
 134         address = _parent->getPhysicalSegment( offset + _start, &actualLength, options );
 135
 136         if (address && length) {
 137                 *length = min( _length - offset, actualLength );
 138         }
 139
 140         return address;
 141 }
 142
 143 IOReturn
 144 IOSubMemoryDescriptor::setPurgeable( IOOptionBits newState,
 145     IOOptionBits * oldState )
 146 {
 147         IOReturn err;
 148
 149         err = _parent->setPurgeable( newState, oldState );
 150
 151         return err;
 152 }
 153
 154 IOReturn
 155 IOSubMemoryDescriptor::prepare(
 156         IODirection forDirection)
 157 {
 158         IOReturn    err;
 159
 160         err = _parent->prepare( forDirection);
 161
 162         return err;
 163 }
 164
 165 IOReturn
 166 IOSubMemoryDescriptor::complete(
 167         IODirection forDirection)
 168 {
 169         IOReturn    err;
 170
 171         err = _parent->complete( forDirection);
 172
 173         return err;
 174 }
 175
 176 IOMemoryMap *
 177 IOSubMemoryDescriptor::makeMapping(
 178         IOMemoryDescriptor *    owner,
 179         task_t                  intoTask,
 180         IOVirtualAddress        address,
 181         IOOptionBits            options,
 182         IOByteCount             offset,
 183         IOByteCount             length )
 184 {
 185         IOMemoryMap * mapping = 0;
 186
 187 #ifndef __LP64__
 188         if (!(kIOMap64Bit & options)) {
 189                 panic("IOSubMemoryDescriptor::makeMapping !64bit");
 190         }
 191 #endif /* !__LP64__ */
 192
 193         mapping = (IOMemoryMap *) _parent->makeMapping(
 194                 owner,
 195                 intoTask,
 196                 address,
 197                 options, _start + offset, length );
 198
 199         return mapping;
 200 }
 201
 202 uint64_t
 203 IOSubMemoryDescriptor::getPreparationID( void )
 204 {
 205         uint64_t pID;
 206
 207         if (!super::getKernelReserved()) {
 208                 return kIOPreparationIDUnsupported;
 209         }
 210
 211         pID = _parent->getPreparationID();
 212         if (reserved->kernReserved[0] != pID) {
 213                 reserved->kernReserved[0] = pID;
 214                 reserved->preparationID   = kIOPreparationIDUnprepared;
 215                 super::setPreparationID();
 216         }
 217
 218         return super::getPreparationID();
 219 }
 220
 221 IOReturn
 222 IOSubMemoryDescriptor::getPageCounts(IOByteCount * residentPageCount,
 223     IOByteCount * dirtyPageCount)
 224 {
 225         return _parent->getPageCounts(residentPageCount, dirtyPageCount);
 226 }