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 #include <IOKit/IOLib.h>
  31
  32 #include "IOKitKernelInternal.h"
  33
  34 #define super IOMemoryDescriptor
  35
  36 OSDefineMetaClassAndStructors(IOSubMemoryDescriptor, IOMemoryDescriptor)
  37
  38 IOReturn
  39 IOSubMemoryDescriptor::redirect( task_t safeTask, bool doRedirect )
  40 {
  41 #ifdef __LP64__
  42         super::redirect( safeTask, doRedirect );
  43 #endif /* __LP64__ */
  44         return _parent->redirect( safeTask, doRedirect );
  45 }
  46
  47 IOSubMemoryDescriptor *
  48 IOSubMemoryDescriptor::withSubRange(IOMemoryDescriptor *        of,
  49     IOByteCount             offset,
  50     IOByteCount             length,
  51     IOOptionBits            options)
  52 {
  53         IOSubMemoryDescriptor *self = new IOSubMemoryDescriptor;
  54
  55         if (self && !self->initSubRange(of, offset, length, (IODirection) options)) {
  56                 self->release();
  57                 self = NULL;
  58         }
  59         return self;
  60 }
  61
  62 bool
  63 IOSubMemoryDescriptor::initSubRange( IOMemoryDescriptor * parent,
  64     IOByteCount offset, IOByteCount length,
  65     IODirection direction )
  66 {
  67         if (parent && ((offset + length) > parent->getLength())) {
  68                 return false;
  69         }
  70
  71         /*
  72          * We can check the _parent instance variable before having ever set it
  73          * to an initial value because I/O Kit guarantees that all our instance
  74          * variables are zeroed on an object's allocation.
  75          */
  76
  77         if (!_parent) {
  78                 if (!super::init()) {
  79                         return false;
  80                 }
  81         } else {
  82                 /*
  83                  * An existing memory descriptor is being retargeted to
  84                  * point to somewhere else.  Clean up our present state.
  85                  */
  86
  87                 _parent->release();
  88         }
  89
  90         if (parent) {
  91                 parent->retain();
  92                 _tag    = parent->getTag();
  93         } else {
  94                 _tag    = 0;
  95         }
  96         _parent     = parent;
  97         _start      = offset;
  98         _length     = length;
  99         _flags      = direction;
 100         _flags |= kIOMemoryThreadSafe;
 101
 102 #ifndef __LP64__
 103         _direction  = (IODirection) (_flags & kIOMemoryDirectionMask);
 104 #endif /* !__LP64__ */
 105
 106         return true;
 107 }
 108
 109 void
 110 IOSubMemoryDescriptor::free( void )
 111 {
 112         if (_parent) {
 113                 _parent->release();
 114         }
 115
 116         super::free();
 117 }
 118
 119 addr64_t
 120 IOSubMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount * length, IOOptionBits options)
 121 {
 122         addr64_t    address;
 123         IOByteCount actualLength;
 124
 125         assert(offset <= _length);
 126
 127         if (length) {
 128                 *length = 0;
 129         }
 130
 131         if (offset >= _length) {
 132                 return 0;
 133         }
 134
 135         address = _parent->getPhysicalSegment( offset + _start, &actualLength, options );
 136
 137         if (address && length) {
 138                 *length = min( _length - offset, actualLength );
 139         }
 140
 141         return address;
 142 }
 143
 144 IOReturn
 145 IOSubMemoryDescriptor::setPurgeable( IOOptionBits newState,
 146     IOOptionBits * oldState )
 147 {
 148         IOReturn err;
 149
 150         err = _parent->setPurgeable( newState, oldState );
 151
 152         return err;
 153 }
 154
 155 IOReturn
 156 IOSubMemoryDescriptor::setOwnership( task_t newOwner,
 157     int newLedgerTag,
 158     IOOptionBits newLedgerOptions )
 159 {
 160         IOReturn err;
 161
 162         if (iokit_iomd_setownership_enabled == FALSE) {
 163                 return kIOReturnUnsupported;
 164         }
 165
 166         err = _parent->setOwnership( newOwner, newLedgerTag, newLedgerOptions );
 167
 168         return err;
 169 }
 170
 171 IOReturn
 172 IOSubMemoryDescriptor::prepare(
 173         IODirection forDirection)
 174 {
 175         IOReturn    err;
 176
 177         err = _parent->prepare( forDirection);
 178
 179         return err;
 180 }
 181
 182 IOReturn
 183 IOSubMemoryDescriptor::complete(
 184         IODirection forDirection)
 185 {
 186         IOReturn    err;
 187
 188         err = _parent->complete( forDirection);
 189
 190         return err;
 191 }
 192
 193 IOMemoryMap *
 194 IOSubMemoryDescriptor::makeMapping(
 195         IOMemoryDescriptor *    owner,
 196         task_t                  intoTask,
 197         IOVirtualAddress        address,
 198         IOOptionBits            options,
 199         IOByteCount             offset,
 200         IOByteCount             length )
 201 {
 202         IOMemoryMap * mapping = NULL;
 203
 204 #ifndef __LP64__
 205         if (!(kIOMap64Bit & options)) {
 206                 panic("IOSubMemoryDescriptor::makeMapping !64bit");
 207         }
 208 #endif /* !__LP64__ */
 209
 210         mapping = (IOMemoryMap *) _parent->makeMapping(
 211                 owner,
 212                 intoTask,
 213                 address,
 214                 options, _start + offset, length );
 215
 216         return mapping;
 217 }
 218
 219 uint64_t
 220 IOSubMemoryDescriptor::getPreparationID( void )
 221 {
 222         uint64_t pID;
 223
 224         if (!super::getKernelReserved()) {
 225                 return kIOPreparationIDUnsupported;
 226         }
 227
 228         pID = _parent->getPreparationID();
 229         if (reserved->kernReserved[0] != pID) {
 230                 reserved->kernReserved[0] = pID;
 231                 reserved->preparationID   = kIOPreparationIDUnprepared;
 232                 super::setPreparationID();
 233         }
 234
 235         return super::getPreparationID();
 236 }
 237
 238 IOReturn
 239 IOSubMemoryDescriptor::getPageCounts(IOByteCount * residentPageCount,
 240     IOByteCount * dirtyPageCount)
 241 {
 242         return _parent->getPageCounts(residentPageCount, dirtyPageCount);
 243 }