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--- xnu/xnu-12377.101.15/iokit/Kernel/IOMultiMemoryDescriptor.cpp
+++ xnu/xnu-201/iokit/Kernel/IOMultiMemoryDescriptor.cpp
@@ -1,29 +1,23 @@
/*
* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. The rights granted to you under the License
- * may not be used to create, or enable the creation or redistribution of,
- * unlawful or unlicensed copies of an Apple operating system, or to
- * circumvent, violate, or enable the circumvention or violation of, any
- * terms of an Apple operating system software license agreement.
- *
- * Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License"). You may not use this file except in compliance with the
+ * License. Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ *
+ * This Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
*/
#include <IOKit/IOLib.h>
@@ -32,446 +26,371 @@
#define super IOMemoryDescriptor
OSDefineMetaClassAndStructors(IOMultiMemoryDescriptor, IOMemoryDescriptor)
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+bool IOMultiMemoryDescriptor::initWithAddress(
+ void * /* address */ ,
+ IOByteCount /* withLength */ ,
+ IODirection /* withDirection */ )
+{
+ return false;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+bool IOMultiMemoryDescriptor::initWithAddress(
+ vm_address_t /* address */ ,
+ IOByteCount /* withLength */ ,
+ IODirection /* withDirection */ ,
+ task_t /* withTask */ )
+{
+ return false;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+bool IOMultiMemoryDescriptor::initWithPhysicalAddress(
+ IOPhysicalAddress /* address */ ,
+ IOByteCount /* withLength */ ,
+ IODirection /* withDirection */ )
+{
+ return false;
+}
+
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+bool IOMultiMemoryDescriptor::initWithPhysicalRanges(
+ IOPhysicalRange * /* ranges */ ,
+ UInt32 /* withCount */ ,
+ IODirection /* withDirection */ ,
+ bool /* asReference */ )
+{
+ return false;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+bool IOMultiMemoryDescriptor::initWithRanges(
+ IOVirtualRange * /* ranges */ ,
+ UInt32 /* withCount */ ,
+ IODirection /* withDirection */ ,
+ task_t /* withTask */ ,
+ bool /* asReference */ )
+{
+ return false;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
IOMultiMemoryDescriptor * IOMultiMemoryDescriptor::withDescriptors(
- IOMemoryDescriptor * *descriptors,
- UInt32 withCount,
- IODirection withDirection,
- bool asReference )
-{
- //
- // Create a new IOMultiMemoryDescriptor. The "buffer" is made up of several
- // memory descriptors, that are to be chained end-to-end to make up a single
- // memory descriptor.
- //
- // Passing the ranges as a reference will avoid an extra allocation.
- //
-
- IOMultiMemoryDescriptor * me = new IOMultiMemoryDescriptor;
-
- if (me && me->initWithDescriptors(
- /* descriptors */ descriptors,
- /* withCount */ withCount,
- /* withDirection */ withDirection,
- /* asReference */ asReference ) == false) {
- me->release();
- me = NULL;
- }
-
- return me;
-}
-
-bool
-IOMultiMemoryDescriptor::initWithDescriptors(
- IOMemoryDescriptor ** descriptors,
- UInt32 withCount,
- IODirection withDirection,
- bool asReference )
-{
- unsigned index;
- IOOptionBits copyFlags;
- //
- // Initialize an IOMultiMemoryDescriptor. The "buffer" is made up of several
- // memory descriptors, that are to be chained end-to-end to make up a single
- // memory descriptor.
- //
- // Passing the ranges as a reference will avoid an extra allocation.
- //
-
- assert(descriptors);
-
- // Release existing descriptors, if any
- if (_descriptors) {
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- _descriptors[index]->release();
- }
-
- if (_descriptorsIsAllocated) {
- IODelete(_descriptors, IOMemoryDescriptor *, _descriptorsCount);
- }
- } else {
- // Ask our superclass' opinion.
- if (super::init() == false) {
- return false;
- }
- }
-
- // Initialize our minimal state.
-
- _descriptors = NULL;
- _descriptorsCount = withCount;
- _descriptorsIsAllocated = asReference ? false : true;
- _flags = withDirection;
-#ifndef __LP64__
- _direction = (IODirection) (_flags & kIOMemoryDirectionMask);
-#endif /* !__LP64__ */
- _length = 0;
- _mappings = NULL;
- _tag = 0;
-
- if (asReference) {
- _descriptors = descriptors;
- } else {
- _descriptors = IONew(IOMemoryDescriptor *, withCount);
- if (_descriptors == NULL) {
- return false;
- }
-
- bcopy( /* from */ descriptors,
- /* to */ _descriptors,
- /* bytes */ withCount * sizeof(IOMemoryDescriptor *));
- }
-
- for (index = 0; index < withCount; index++) {
- descriptors[index]->retain();
- _length += descriptors[index]->getLength();
- if (_tag == 0) {
- _tag = descriptors[index]->getTag();
- }
- assert(descriptors[index]->getDirection() ==
- (withDirection & kIOMemoryDirectionMask));
- }
-
- enum { kCopyFlags = kIOMemoryBufferPageable };
- copyFlags = 0;
- for (index = 0; index < withCount; index++) {
- if (!index) {
- copyFlags = (kCopyFlags & descriptors[index]->_flags);
- } else if (copyFlags != (kCopyFlags & descriptors[index]->_flags)) {
- break;
- }
- }
- if (index < withCount) {
- return false;
- }
- _flags |= copyFlags;
-
- return true;
-}
-
-void
-IOMultiMemoryDescriptor::free()
-{
- //
- // Free all of this object's outstanding resources.
- //
-
- if (_descriptors) {
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- _descriptors[index]->release();
- }
-
- if (_descriptorsIsAllocated) {
- IODelete(_descriptors, IOMemoryDescriptor *, _descriptorsCount);
- }
- }
-
- super::free();
-}
-
-IOReturn
-IOMultiMemoryDescriptor::prepare(IODirection forDirection)
-{
- //
- // Prepare the memory for an I/O transfer.
- //
- // This involves paging in the memory and wiring it down for the duration
- // of the transfer. The complete() method finishes the processing of the
- // memory after the I/O transfer finishes.
- //
-
- unsigned index;
- IOReturn status = kIOReturnInternalError;
- IOReturn statusUndo;
-
- if (forDirection == kIODirectionNone) {
- forDirection = getDirection();
- }
-
- for (index = 0; index < _descriptorsCount; index++) {
- status = _descriptors[index]->prepare(forDirection);
- if (status != kIOReturnSuccess) {
- break;
- }
- }
-
- if (status != kIOReturnSuccess) {
- for (unsigned indexUndo = 0; indexUndo < index; indexUndo++) {
- statusUndo = _descriptors[indexUndo]->complete(forDirection);
- assert(statusUndo == kIOReturnSuccess);
- }
- }
-
- return status;
-}
-
-IOReturn
-IOMultiMemoryDescriptor::complete(IODirection forDirection)
-{
- //
- // Complete processing of the memory after an I/O transfer finishes.
- //
- // This method shouldn't be called unless a prepare() was previously issued;
- // the prepare() and complete() must occur in pairs, before and after an I/O
- // transfer.
- //
-
- IOReturn status;
- IOReturn statusFinal = kIOReturnSuccess;
-
- if (forDirection == kIODirectionNone) {
- forDirection = getDirection();
- }
-
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- status = _descriptors[index]->complete(forDirection);
- if (status != kIOReturnSuccess) {
- statusFinal = status;
- }
- assert(status == kIOReturnSuccess);
- }
-
- return statusFinal;
-}
-
-addr64_t
-IOMultiMemoryDescriptor::getPhysicalSegment(IOByteCount offset,
- IOByteCount * length,
- IOOptionBits options)
-{
- //
- // 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.
- //
-
- assert(offset <= _length);
-
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- if (offset < _descriptors[index]->getLength()) {
- return _descriptors[index]->getPhysicalSegment(offset, length, options);
- }
- offset -= _descriptors[index]->getLength();
- }
-
- if (length) {
- *length = 0;
- }
-
- return 0;
-}
-
-#include "IOKitKernelInternal.h"
-
-IOReturn
-IOMultiMemoryDescriptor::doMap(vm_map_t __addressMap,
- IOVirtualAddress * __address,
- IOOptionBits options,
- IOByteCount __offset,
- IOByteCount __length)
-{
- IOMemoryMap * mapping = (IOMemoryMap *) *__address;
- vm_map_t map = mapping->fAddressMap;
- mach_vm_size_t offset = mapping->fOffset;
- mach_vm_size_t length = mapping->fLength;
- mach_vm_address_t address = mapping->fAddress;
-
- kern_return_t err;
- IOOptionBits subOptions;
- mach_vm_size_t mapOffset;
- mach_vm_size_t bytesRemaining, chunk;
- mach_vm_address_t nextAddress;
- IOMemoryDescriptorMapAllocRef ref;
- vm_prot_t prot;
-
- do{
- prot = VM_PROT_READ;
- if (!(kIOMapReadOnly & options)) {
- prot |= VM_PROT_WRITE;
- }
-
- if (kIOMapOverwrite & options) {
- if ((map == kernel_map) && (kIOMemoryBufferPageable & _flags)) {
- map = IOPageableMapForAddress(address);
- }
- err = KERN_SUCCESS;
- } else {
- ref.map = map;
- ref.tag = IOMemoryTag(map);
- ref.options = options;
- ref.size = length;
- ref.prot = prot;
- if (options & kIOMapAnywhere) {
- // vm_map looks for addresses above here, even when VM_FLAGS_ANYWHERE
- ref.mapped = 0;
- } else {
- ref.mapped = mapping->fAddress;
- }
-
- if ((ref.map == kernel_map) && (kIOMemoryBufferPageable & _flags)) {
- err = IOIteratePageableMaps(ref.size, &IOMemoryDescriptorMapAlloc, &ref);
- } else {
- err = IOMemoryDescriptorMapAlloc(ref.map, &ref);
- }
-
- if (KERN_SUCCESS != err) {
- break;
- }
-
- address = ref.mapped;
- mapping->fAddress = address;
- }
-
- mapOffset = offset;
- bytesRemaining = length;
- nextAddress = address;
- assert(mapOffset <= _length);
- subOptions = (options & ~kIOMapAnywhere) | kIOMapOverwrite;
-
- for (unsigned index = 0; bytesRemaining && (index < _descriptorsCount); index++) {
- chunk = _descriptors[index]->getLength();
- if (mapOffset >= chunk) {
- mapOffset -= chunk;
- continue;
- }
- chunk -= mapOffset;
- if (chunk > bytesRemaining) {
- chunk = bytesRemaining;
- }
- IOMemoryMap * subMap;
- subMap = _descriptors[index]->createMappingInTask(mapping->fAddressTask, nextAddress, subOptions, mapOffset, chunk );
- if (!subMap) {
- break;
- }
- subMap->release(); // kIOMapOverwrite means it will not deallocate
-
- bytesRemaining -= chunk;
- nextAddress += chunk;
- mapOffset = 0;
- }
- if (bytesRemaining) {
- err = kIOReturnUnderrun;
- }
- }while (false);
-
- return err;
-}
-
-IOReturn
-IOMultiMemoryDescriptor::setPurgeable( IOOptionBits newState,
- IOOptionBits * oldState )
-{
- IOReturn err;
- IOOptionBits totalState, state;
-
- totalState = kIOMemoryPurgeableNonVolatile;
- err = kIOReturnSuccess;
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- err = _descriptors[index]->setPurgeable(newState, &state);
- if (kIOReturnSuccess != err) {
- break;
- }
-
- if (kIOMemoryPurgeableEmpty == state) {
- totalState = kIOMemoryPurgeableEmpty;
- } else if (kIOMemoryPurgeableEmpty == totalState) {
- continue;
- } else if (kIOMemoryPurgeableVolatile == totalState) {
- continue;
- } else if (kIOMemoryPurgeableVolatile == state) {
- totalState = kIOMemoryPurgeableVolatile;
- } else {
- totalState = kIOMemoryPurgeableNonVolatile;
- }
- }
- if (oldState) {
- *oldState = totalState;
- }
-
- return err;
-}
-
-IOReturn
-IOMultiMemoryDescriptor::setOwnership( task_t newOwner,
- int newLedgerTag,
- IOOptionBits newLedgerOptions )
-{
- IOReturn err;
-
- if (iokit_iomd_setownership_enabled == FALSE) {
- return kIOReturnUnsupported;
- }
-
- err = kIOReturnSuccess;
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- err = _descriptors[index]->setOwnership(newOwner, newLedgerTag, newLedgerOptions);
- if (kIOReturnSuccess != err) {
- break;
- }
- }
-
- return err;
-}
-
-IOReturn
-IOMultiMemoryDescriptor::getPageCounts(IOByteCount * pResidentPageCount,
- IOByteCount * pDirtyPageCount, IOByteCount * pSwappedPageCount)
-{
- IOReturn err;
- IOByteCount totalResidentPageCount, totalDirtyPageCount, totalSwappedPageCount;
- IOByteCount residentPageCount, dirtyPageCount, swappedPageCount;
-
- err = kIOReturnSuccess;
- totalResidentPageCount = totalDirtyPageCount = totalSwappedPageCount = 0;
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- err = _descriptors[index]->getPageCounts(&residentPageCount, &dirtyPageCount, &swappedPageCount);
- if (kIOReturnSuccess != err) {
- break;
- }
- totalResidentPageCount += residentPageCount;
- totalDirtyPageCount += dirtyPageCount;
- totalSwappedPageCount += swappedPageCount;
- }
-
- if (pResidentPageCount) {
- *pResidentPageCount = totalResidentPageCount;
- }
- if (pDirtyPageCount) {
- *pDirtyPageCount = totalDirtyPageCount;
- }
- if (pSwappedPageCount) {
- *pSwappedPageCount = totalSwappedPageCount;
- }
-
- return err;
-}
-
-IOReturn
-IOMultiMemoryDescriptor::getPageCounts(IOByteCount * pResidentPageCount,
- IOByteCount * pDirtyPageCount)
-{
- return getPageCounts(pResidentPageCount, pDirtyPageCount, NULL);
-}
-
-uint64_t
-IOMultiMemoryDescriptor::getPreparationID( void )
-{
- if (!super::getKernelReserved()) {
- return kIOPreparationIDUnsupported;
- }
-
- for (unsigned index = 0; index < _descriptorsCount; index++) {
- uint64_t preparationID = _descriptors[index]->getPreparationID();
-
- if (preparationID == kIOPreparationIDUnsupported) {
- return kIOPreparationIDUnsupported;
- }
-
- if (preparationID == kIOPreparationIDUnprepared) {
- return kIOPreparationIDUnprepared;
- }
- }
-
- super::setPreparationID();
-
- return super::getPreparationID();
-}
+ IOMemoryDescriptor ** descriptors,
+ UInt32 withCount,
+ IODirection withDirection,
+ bool asReference = false )
+{
+ //
+ // Create a new IOMultiMemoryDescriptor. The "buffer" is made up of several
+ // memory descriptors, that are to be chained end-to-end to make up a single
+ // memory descriptor.
+ //
+ // Passing the ranges as a reference will avoid an extra allocation.
+ //
+
+ IOMultiMemoryDescriptor * me = new IOMultiMemoryDescriptor;
+
+ if ( me && me->initWithDescriptors(
+ /* descriptors */ descriptors,
+ /* withCount */ withCount,
+ /* withDirection */ withDirection,
+ /* asReference */ asReference ) == false )
+ {
+ me->release();
+ me = 0;
+ }
+
+ return me;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+bool IOMultiMemoryDescriptor::initWithDescriptors(
+ IOMemoryDescriptor ** descriptors,
+ UInt32 withCount,
+ IODirection withDirection,
+ bool asReference = false )
+{
+ //
+ // Initialize an IOMultiMemoryDescriptor. The "buffer" is made up of several
+ // memory descriptors, that are to be chained end-to-end to make up a single
+ // memory descriptor.
+ //
+ // Passing the ranges as a reference will avoid an extra allocation.
+ //
+
+ assert(descriptors);
+ assert(withCount);
+
+ // Ask our superclass' opinion.
+
+ if ( super::init() == false ) return false;
+
+ // Initialize our minimal state.
+
+ _descriptors = 0;
+ _descriptorsCount = withCount;
+ _descriptorsIsAllocated = asReference ? false : true;
+ _direction = withDirection;
+ _length = 0;
+ _mappings = 0;
+ _tag = 0;
+
+ if ( asReference )
+ {
+ _descriptors = descriptors;
+ }
+ else
+ {
+ _descriptors = IONew(IOMemoryDescriptor *, withCount);
+ if ( _descriptors == 0 ) return false;
+
+ bcopy( /* from */ descriptors,
+ /* to */ _descriptors,
+ /* bytes */ withCount * sizeof(IOMemoryDescriptor *) );
+ }
+
+ for ( unsigned index = 0; index < withCount; index++ )
+ {
+ descriptors[index]->retain();
+ _length += descriptors[index]->getLength();
+ if ( _tag == 0 ) _tag = descriptors[index]->getTag();
+ assert(descriptors[index]->getDirection() == withDirection);
+ }
+
+ return true;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+void IOMultiMemoryDescriptor::free()
+{
+ //
+ // Free all of this object's outstanding resources.
+ //
+
+ if ( _descriptors )
+ {
+ for ( unsigned index = 0; index < _descriptorsCount; index++ )
+ _descriptors[index]->release();
+
+ if ( _descriptorsIsAllocated )
+ IODelete(_descriptors, IOMemoryDescriptor *, _descriptorsCount);
+ }
+
+ super::free();
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+IOReturn IOMultiMemoryDescriptor::prepare(IODirection forDirection)
+{
+ //
+ // Prepare the memory for an I/O transfer.
+ //
+ // This involves paging in the memory and wiring it down for the duration
+ // of the transfer. The complete() method finishes the processing of the
+ // memory after the I/O transfer finishes.
+ //
+
+ unsigned index;
+ IOReturn status = kIOReturnInternalError;
+ IOReturn statusUndo;
+
+ if ( forDirection == kIODirectionNone )
+ {
+ forDirection = _direction;
+ }
+
+ for ( index = 0; index < _descriptorsCount; index++ )
+ {
+ status = _descriptors[index]->prepare(forDirection);
+ if ( status != kIOReturnSuccess ) break;
+ }
+
+ if ( status != kIOReturnSuccess )
+ {
+ for ( unsigned indexUndo = 0; indexUndo <= index; indexUndo++ )
+ {
+ statusUndo = _descriptors[index]->complete(forDirection);
+ assert(statusUndo == kIOReturnSuccess);
+ }
+ }
+
+ return status;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+IOReturn IOMultiMemoryDescriptor::complete(IODirection forDirection)
+{
+ //
+ // Complete processing of the memory after an I/O transfer finishes.
+ //
+ // This method shouldn't be called unless a prepare() was previously issued;
+ // the prepare() and complete() must occur in pairs, before and after an I/O
+ // transfer.
+ //
+
+ IOReturn status;
+ IOReturn statusFinal = kIOReturnSuccess;
+
+ if ( forDirection == kIODirectionNone )
+ {
+ forDirection = _direction;
+ }
+
+ for ( unsigned index = 0; index < _descriptorsCount; index++ )
+ {
+ status = _descriptors[index]->complete(forDirection);
+ if ( status != kIOReturnSuccess ) statusFinal = status;
+ assert(status == kIOReturnSuccess);
+ }
+
+ return statusFinal;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+IOPhysicalAddress IOMultiMemoryDescriptor::getPhysicalSegment(
+ IOByteCount offset,
+ IOByteCount * length )
+{
+ //
+ // 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.
+ //
+
+ assert(offset <= _length);
+
+ for ( unsigned index = 0; index < _descriptorsCount; index++ )
+ {
+ if ( offset < _descriptors[index]->getLength() )
+ {
+ return _descriptors[index]->getPhysicalSegment(offset, length);
+ }
+ offset -= _descriptors[index]->getLength();
+ }
+
+ if ( length ) *length = 0;
+
+ return 0;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+IOPhysicalAddress IOMultiMemoryDescriptor::getSourceSegment(
+ IOByteCount offset,
+ IOByteCount * length )
+{
+ //
+ // 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.
+ //
+
+ assert(offset <= _length);
+
+ for ( unsigned index = 0; index < _descriptorsCount; index++ )
+ {
+ if ( offset < _descriptors[index]->getLength() )
+ {
+ return _descriptors[index]->getSourceSegment(offset, length);
+ }
+ offset -= _descriptors[index]->getLength();
+ }
+
+ if ( length ) *length = 0;
+
+ return 0;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+void * IOMultiMemoryDescriptor::getVirtualSegment( IOByteCount /* offset */ ,
+ IOByteCount * /* length */ )
+{
+ return 0;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+IOByteCount IOMultiMemoryDescriptor::readBytes( IOByteCount offset,
+ void * bytes,
+ IOByteCount withLength )
+{
+ //
+ // Copies data from the memory descriptor's buffer at the given offset, to
+ // the specified buffer. Returns the number of bytes copied.
+ //
+
+ IOByteCount bytesCopied = 0;
+ unsigned index;
+
+ for ( index = 0; index < _descriptorsCount; index++ )
+ {
+ if ( offset < _descriptors[index]->getLength() ) break;
+ offset -= _descriptors[index]->getLength();
+ }
+
+ for ( ; index < _descriptorsCount && withLength; index++)
+ {
+ IOByteCount copy = min(_descriptors[index]->getLength(), withLength);
+ IOByteCount copied = _descriptors[index]->readBytes(offset,bytes,copy);
+
+ bytesCopied += copied;
+ if ( copied != copy ) break;
+
+ bytes = ((UInt8 *) bytes) + copied;
+ withLength -= copied;
+ offset = 0;
+ }
+
+ return bytesCopied;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+IOByteCount IOMultiMemoryDescriptor::writeBytes( IOByteCount offset,
+ const void * bytes,
+ IOByteCount withLength )
+{
+ //
+ // Copies data to the memory descriptor's buffer at the given offset, from
+ // the specified buffer. Returns the number of bytes copied.
+ //
+
+ IOByteCount bytesCopied = 0;
+ unsigned index;
+
+ for ( index = 0; index < _descriptorsCount; index++ )
+ {
+ if ( offset < _descriptors[index]->getLength() ) break;
+ offset -= _descriptors[index]->getLength();
+ }
+
+ for ( ; index < _descriptorsCount && withLength; index++)
+ {
+ IOByteCount copy = min(_descriptors[index]->getLength(), withLength);
+ IOByteCount copied = _descriptors[index]->writeBytes(offset,bytes,copy);
+
+ bytesCopied += copied;
+ if ( copied != copy ) break;
+
+ bytes = ((UInt8 *) bytes) + copied;
+ withLength -= copied;
+ offset = 0;
+ }
+
+ return bytesCopied;
+}