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