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--- xnu/xnu-2050.9.2/iokit/Kernel/IOBufferMemoryDescriptor.cpp
+++ xnu/xnu-344.12.2/iokit/Kernel/IOBufferMemoryDescriptor.cpp
@@ -1,286 +1,206 @@
/*
* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * @APPLE_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.
+ * 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.
*
- * 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
+ * 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.
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
*
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
- */
-
-#define _IOMEMORYDESCRIPTOR_INTERNAL_
-
+ * @APPLE_LICENSE_HEADER_END@
+ */
#include <IOKit/assert.h>
#include <IOKit/system.h>
#include <IOKit/IOLib.h>
-#include <IOKit/IOMapper.h>
#include <IOKit/IOBufferMemoryDescriptor.h>
-#include <libkern/OSDebug.h>
-
-#include "IOKitKernelInternal.h"
__BEGIN_DECLS
void ipc_port_release_send(ipc_port_t port);
#include <vm/pmap.h>
-
__END_DECLS
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-enum
-{
- kInternalFlagPhysical = 0x00000001,
- kInternalFlagPageSized = 0x00000002
-};
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+extern "C" vm_map_t IOPageableMapForAddress( vm_address_t address );
#define super IOGeneralMemoryDescriptor
OSDefineMetaClassAndStructors(IOBufferMemoryDescriptor,
IOGeneralMemoryDescriptor);
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-#ifndef __LP64__
+bool IOBufferMemoryDescriptor::initWithAddress(
+ void * /* address */ ,
+ IOByteCount /* withLength */ ,
+ IODirection /* withDirection */ )
+{
+ return false;
+}
+
+bool IOBufferMemoryDescriptor::initWithAddress(
+ vm_address_t /* address */ ,
+ IOByteCount /* withLength */ ,
+ IODirection /* withDirection */ ,
+ task_t /* withTask */ )
+{
+ return false;
+}
+
+bool IOBufferMemoryDescriptor::initWithPhysicalAddress(
+ IOPhysicalAddress /* address */ ,
+ IOByteCount /* withLength */ ,
+ IODirection /* withDirection */ )
+{
+ return false;
+}
+
+bool IOBufferMemoryDescriptor::initWithPhysicalRanges(
+ IOPhysicalRange * /* ranges */ ,
+ UInt32 /* withCount */ ,
+ IODirection /* withDirection */ ,
+ bool /* asReference */ )
+{
+ return false;
+}
+
+bool IOBufferMemoryDescriptor::initWithRanges(
+ IOVirtualRange * /* ranges */ ,
+ UInt32 /* withCount */ ,
+ IODirection /* withDirection */ ,
+ task_t /* withTask */ ,
+ bool /* asReference */ )
+{
+ return false;
+}
+
bool IOBufferMemoryDescriptor::initWithOptions(
IOOptionBits options,
vm_size_t capacity,
vm_offset_t alignment,
task_t inTask)
{
- mach_vm_address_t physicalMask = 0;
- return (initWithPhysicalMask(inTask, options, capacity, alignment, physicalMask));
-}
-#endif /* !__LP64__ */
-
-bool IOBufferMemoryDescriptor::initWithPhysicalMask(
- task_t inTask,
- IOOptionBits options,
- mach_vm_size_t capacity,
- mach_vm_address_t alignment,
- mach_vm_address_t physicalMask)
-{
- kern_return_t kr;
- task_t mapTask = NULL;
- vm_map_t vmmap = NULL;
- mach_vm_address_t highestMask = 0;
- IOOptionBits iomdOptions = kIOMemoryTypeVirtual64 | kIOMemoryAsReference;
+ vm_map_t map = 0;
if (!capacity)
return false;
- _options = options;
- _capacity = capacity;
- _internalFlags = 0;
- _internalReserved = 0;
- _buffer = 0;
-
- _ranges.v64 = IONew(IOAddressRange, 1);
- if (!_ranges.v64)
- return (false);
- _ranges.v64->address = 0;
- _ranges.v64->length = 0;
- // make sure super::free doesn't dealloc _ranges before super::init
- _flags = kIOMemoryAsReference;
-
- // Grab IOMD bits from the Buffer MD options
- iomdOptions |= (options & kIOBufferDescriptorMemoryFlags);
-
- if (physicalMask && (alignment <= 1))
- {
- alignment = ((physicalMask ^ (-1ULL)) & (physicalMask - 1));
- highestMask = (physicalMask | alignment);
- alignment++;
- if (alignment < page_size)
- alignment = page_size;
- }
-
- if ((options & (kIOMemorySharingTypeMask | kIOMapCacheMask | kIOMemoryClearEncrypt)) && (alignment < page_size))
- alignment = page_size;
-
- if (alignment >= page_size)
- capacity = round_page(capacity);
-
- if (alignment > page_size)
- options |= kIOMemoryPhysicallyContiguous;
+ _options = options;
+ _capacity = capacity;
+ _physAddrs = 0;
+ _physSegCount = 0;
+ _buffer = 0;
+
+ if ((options & kIOMemorySharingTypeMask) && (alignment < page_size))
+ alignment = page_size;
+
+ if ((inTask != kernel_task) && !(options & kIOMemoryPageable))
+ return false;
_alignment = alignment;
-
- if ((inTask != kernel_task) && !(options & kIOMemoryPageable))
- return false;
-
- // set flags for entry + object create
- vm_prot_t memEntryCacheMode = VM_PROT_READ | VM_PROT_WRITE;
-
- // set memory entry cache mode
- switch (options & kIOMapCacheMask)
- {
- case kIOMapInhibitCache:
- SET_MAP_MEM(MAP_MEM_IO, memEntryCacheMode);
- break;
-
- case kIOMapWriteThruCache:
- SET_MAP_MEM(MAP_MEM_WTHRU, memEntryCacheMode);
- break;
-
- case kIOMapWriteCombineCache:
- SET_MAP_MEM(MAP_MEM_WCOMB, memEntryCacheMode);
- break;
-
- case kIOMapCopybackCache:
- SET_MAP_MEM(MAP_MEM_COPYBACK, memEntryCacheMode);
- break;
-
- case kIOMapCopybackInnerCache:
- SET_MAP_MEM(MAP_MEM_INNERWBACK, memEntryCacheMode);
- break;
-
- case kIOMapDefaultCache:
- default:
- SET_MAP_MEM(MAP_MEM_NOOP, memEntryCacheMode);
- break;
- }
-
if (options & kIOMemoryPageable)
{
- iomdOptions |= kIOMemoryBufferPageable;
-
- // must create the entry before any pages are allocated
-
- // set flags for entry + object create
- memEntryCacheMode |= MAP_MEM_NAMED_CREATE;
-
- if (options & kIOMemoryPurgeable)
- memEntryCacheMode |= MAP_MEM_PURGABLE;
- }
- else
- {
- memEntryCacheMode |= MAP_MEM_NAMED_REUSE;
- vmmap = kernel_map;
-
- // Buffer shouldn't auto prepare they should be prepared explicitly
- // But it never was enforced so what are you going to do?
- iomdOptions |= kIOMemoryAutoPrepare;
-
- /* Allocate a wired-down buffer inside kernel space. */
-
- if ((options & kIOMemoryPhysicallyContiguous) || highestMask || (alignment > page_size))
+ if (inTask == kernel_task)
{
- _internalFlags |= kInternalFlagPhysical;
- if (highestMask)
- {
- _internalFlags |= kInternalFlagPageSized;
- capacity = round_page(capacity);
- }
- _buffer = (void *) IOKernelAllocateWithPhysicalRestrict(capacity, highestMask, alignment,
- (0 != (options & kIOMemoryPhysicallyContiguous)));
- }
- else if (alignment > 1)
- {
- _buffer = IOMallocAligned(capacity, alignment);
+ /* Allocate some kernel address space. */
+ _buffer = IOMallocPageable(capacity, alignment);
+ if (_buffer)
+ map = IOPageableMapForAddress((vm_address_t) _buffer);
}
else
{
- _buffer = IOMalloc(capacity);
- }
-
- if (!_buffer)
- {
- return false;
- }
- }
-
- if( (options & (kIOMemoryPageable | kIOMapCacheMask))) {
- ipc_port_t sharedMem;
- vm_size_t size = round_page(capacity);
-
- kr = mach_make_memory_entry(vmmap,
- &size, (vm_offset_t)_buffer,
- memEntryCacheMode, &sharedMem,
- NULL );
-
- if( (KERN_SUCCESS == kr) && (size != round_page(capacity))) {
- ipc_port_release_send( sharedMem );
- kr = kIOReturnVMError;
- }
- if( KERN_SUCCESS != kr)
- return( false );
-
- _memEntry = (void *) sharedMem;
-
- if( options & kIOMemoryPageable) {
-#if IOALLOCDEBUG
- debug_iomallocpageable_size += size;
-#endif
- mapTask = inTask;
- if (NULL == inTask)
- inTask = kernel_task;
- }
- else if (options & kIOMapCacheMask)
- {
- // Prefetch each page to put entries into the pmap
- volatile UInt8 * startAddr = (UInt8 *)_buffer;
- volatile UInt8 * endAddr = (UInt8 *)_buffer + capacity;
-
- while (startAddr < endAddr)
- {
- *startAddr;
- startAddr += page_size;
+ kern_return_t kr;
+
+ if( !reserved) {
+ reserved = IONew( ExpansionData, 1 );
+ if( !reserved)
+ return( false );
}
- }
- }
-
- _ranges.v64->address = (mach_vm_address_t) _buffer;;
- _ranges.v64->length = _capacity;
-
- if (!super::initWithOptions(_ranges.v64, 1, 0,
- inTask, iomdOptions, /* System mapper */ 0))
- return false;
-
- if (mapTask)
- {
- if (!reserved) {
- reserved = IONew( ExpansionData, 1 );
- if( !reserved)
+ map = get_task_map(inTask);
+ vm_map_reference(map);
+ reserved->map = map;
+ kr = vm_allocate( map, (vm_address_t *) &_buffer, round_page(capacity),
+ VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_MEMORY_IOKIT) );
+ if( KERN_SUCCESS != kr)
+ return( false );
+
+ // we have to make sure that these pages don't get copied on fork.
+ kr = vm_inherit( map, (vm_address_t) _buffer, round_page(capacity), VM_INHERIT_NONE);
+ if( KERN_SUCCESS != kr)
return( false );
}
- reserved->map = createMappingInTask(mapTask, 0,
- kIOMapAnywhere | (options & kIOMapCacheMask), 0, 0);
- if (!reserved->map)
- {
- _buffer = 0;
- return( false );
- }
- release(); // map took a retain on this
- reserved->map->retain();
- removeMapping(reserved->map);
- mach_vm_address_t buffer = reserved->map->getAddress();
- _buffer = (void *) buffer;
- if (kIOMemoryTypeVirtual64 == (kIOMemoryTypeMask & iomdOptions))
- _ranges.v64->address = buffer;
- }
-
- setLength(_capacity);
-
+ }
+ else
+ {
+ /* Allocate a wired-down buffer inside kernel space. */
+ if (options & kIOMemoryPhysicallyContiguous)
+ _buffer = IOMallocContiguous(capacity, alignment, 0);
+ else if (alignment > 1)
+ _buffer = IOMallocAligned(capacity, alignment);
+ else
+ _buffer = IOMalloc(capacity);
+ }
+
+ if (!_buffer)
+ return false;
+
+ _singleRange.v.address = (vm_address_t) _buffer;
+ _singleRange.v.length = capacity;
+
+ if (!super::initWithRanges(&_singleRange.v, 1,
+ (IODirection) (options & kIOMemoryDirectionMask),
+ inTask, true))
+ return false;
+
+ if (options & kIOMemoryPageable)
+ {
+ _flags |= kIOMemoryRequiresWire;
+
+ kern_return_t kr;
+ ipc_port_t sharedMem = (ipc_port_t) _memEntry;
+ vm_size_t size = round_page(_ranges.v[0].length);
+
+ // must create the entry before any pages are allocated
+ if( 0 == sharedMem) {
+ kr = mach_make_memory_entry( map,
+ &size, _ranges.v[0].address,
+ VM_PROT_READ | VM_PROT_WRITE, &sharedMem,
+ NULL );
+ if( (KERN_SUCCESS == kr) && (size != round_page(_ranges.v[0].length))) {
+ ipc_port_release_send( sharedMem );
+ kr = kIOReturnVMError;
+ }
+ if( KERN_SUCCESS != kr)
+ sharedMem = 0;
+ _memEntry = (void *) sharedMem;
+ }
+ }
+ else
+ {
+ /* Precompute virtual-to-physical page mappings. */
+ vm_address_t inBuffer = (vm_address_t) _buffer;
+ _physSegCount = atop(trunc_page(inBuffer + capacity - 1) -
+ trunc_page(inBuffer)) + 1;
+ _physAddrs = IONew(IOPhysicalAddress, _physSegCount);
+ if (!_physAddrs)
+ return false;
+
+ inBuffer = trunc_page(inBuffer);
+ for (unsigned i = 0; i < _physSegCount; i++) {
+ _physAddrs[i] = pmap_extract(get_task_pmap(kernel_task), inBuffer);
+ assert(_physAddrs[i]); /* supposed to be wired */
+ inBuffer += page_size;
+ }
+ }
+
+ setLength(capacity);
+
return true;
}
@@ -288,51 +208,33 @@
task_t inTask,
IOOptionBits options,
vm_size_t capacity,
- vm_offset_t alignment)
+ vm_offset_t alignment = 1)
{
IOBufferMemoryDescriptor *me = new IOBufferMemoryDescriptor;
- if (me && !me->initWithPhysicalMask(inTask, options, capacity, alignment, 0)) {
+ if (me && !me->initWithOptions(options, capacity, alignment, inTask)) {
me->release();
me = 0;
}
return me;
}
-IOBufferMemoryDescriptor * IOBufferMemoryDescriptor::inTaskWithPhysicalMask(
- task_t inTask,
- IOOptionBits options,
- mach_vm_size_t capacity,
- mach_vm_address_t physicalMask)
-{
- IOBufferMemoryDescriptor *me = new IOBufferMemoryDescriptor;
-
- if (me && !me->initWithPhysicalMask(inTask, options, capacity, 1, physicalMask))
- {
- me->release();
- me = 0;
- }
- return me;
-}
-
-#ifndef __LP64__
bool IOBufferMemoryDescriptor::initWithOptions(
IOOptionBits options,
vm_size_t capacity,
vm_offset_t alignment)
{
- return (initWithPhysicalMask(kernel_task, options, capacity, alignment, (mach_vm_address_t)0));
-}
-#endif /* !__LP64__ */
+ return( initWithOptions(options, capacity, alignment, kernel_task) );
+}
IOBufferMemoryDescriptor * IOBufferMemoryDescriptor::withOptions(
IOOptionBits options,
vm_size_t capacity,
- vm_offset_t alignment)
+ vm_offset_t alignment = 1)
{
IOBufferMemoryDescriptor *me = new IOBufferMemoryDescriptor;
- if (me && !me->initWithPhysicalMask(kernel_task, options, capacity, alignment, 0)) {
+ if (me && !me->initWithOptions(options, capacity, alignment, kernel_task)) {
me->release();
me = 0;
}
@@ -357,7 +259,6 @@
inCapacity, inContiguous ? inCapacity : 1 ));
}
-#ifndef __LP64__
/*
* initWithBytes:
*
@@ -369,9 +270,10 @@
IODirection inDirection,
bool inContiguous)
{
- if (!initWithPhysicalMask(kernel_task, inDirection | kIOMemoryUnshared
- | (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
- inLength, inLength, (mach_vm_address_t)0))
+ if (!initWithOptions(
+ inDirection | kIOMemoryUnshared
+ | (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
+ inLength, inLength ))
return false;
// start out with no data
@@ -382,7 +284,6 @@
return true;
}
-#endif /* !__LP64__ */
/*
* withBytes:
@@ -398,25 +299,9 @@
{
IOBufferMemoryDescriptor *me = new IOBufferMemoryDescriptor;
- if (me && !me->initWithPhysicalMask(
- kernel_task, inDirection | kIOMemoryUnshared
- | (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
- inLength, inLength, 0 ))
- {
- me->release();
- me = 0;
- }
-
- if (me)
- {
- // start out with no data
- me->setLength(0);
-
- if (!me->appendBytes(inBytes, inLength))
- {
- me->release();
- me = 0;
- }
+ if (me && !me->initWithBytes(inBytes, inLength, inDirection, inContiguous)){
+ me->release();
+ me = 0;
}
return me;
}
@@ -428,52 +313,45 @@
*/
void IOBufferMemoryDescriptor::free()
{
- // Cache all of the relevant information on the stack for use
- // after we call super::free()!
- IOOptionBits flags = _flags;
- IOOptionBits internalFlags = _internalFlags;
- IOOptionBits options = _options;
- vm_size_t size = _capacity;
- void * buffer = _buffer;
- IOMemoryMap * map = 0;
- IOAddressRange * range = _ranges.v64;
- vm_offset_t alignment = _alignment;
-
- if (alignment >= page_size)
- size = round_page(size);
+ IOOptionBits options = _options;
+ vm_size_t size = _capacity;
+ void * buffer = _buffer;
+ vm_map_t map = 0;
+ vm_offset_t alignment = _alignment;
+
+ if (_physAddrs)
+ IODelete(_physAddrs, IOPhysicalAddress, _physSegCount);
if (reserved)
{
map = reserved->map;
IODelete( reserved, ExpansionData, 1 );
- if (map)
- map->release();
}
/* super::free may unwire - deallocate buffer afterwards */
super::free();
- if (options & kIOMemoryPageable)
+ if (buffer)
{
-#if IOALLOCDEBUG
- debug_iomallocpageable_size -= round_page(size);
-#endif
- }
- else if (buffer)
- {
- if (internalFlags & kInternalFlagPhysical)
- {
- if (kInternalFlagPageSized & internalFlags)
- size = round_page(size);
- IOKernelFreePhysical((mach_vm_address_t) buffer, size);
+ if (options & kIOMemoryPageable)
+ {
+ if (map)
+ vm_deallocate(map, (vm_address_t) buffer, round_page(size));
+ else
+ IOFreePageable(buffer, size);
+ }
+ else
+ {
+ if (options & kIOMemoryPhysicallyContiguous)
+ IOFreeContiguous(buffer, size);
+ else if (alignment > 1)
+ IOFreeAligned(buffer, size);
+ else
+ IOFree(buffer, size);
}
- else if (alignment > 1)
- IOFreeAligned(buffer, size);
- else
- IOFree(buffer, size);
- }
- if (range && (kIOMemoryAsReference & flags))
- IODelete(range, IOAddressRange, 1);
+ }
+ if (map)
+ vm_map_deallocate(map);
}
/*
@@ -501,7 +379,7 @@
assert(length <= _capacity);
_length = length;
- _ranges.v64->length = length;
+ _singleRange.v.length = length;
}
/*
@@ -513,10 +391,7 @@
*/
void IOBufferMemoryDescriptor::setDirection(IODirection direction)
{
- _flags = (_flags & ~kIOMemoryDirectionMask) | direction;
-#ifndef __LP64__
- _direction = (IODirection) (_flags & kIOMemoryDirectionMask);
-#endif /* !__LP64__ */
+ _direction = direction;
}
/*
@@ -529,20 +404,13 @@
bool
IOBufferMemoryDescriptor::appendBytes(const void * bytes, vm_size_t withLength)
{
- vm_size_t actualBytesToCopy = min(withLength, _capacity - _length);
- IOByteCount offset;
+ vm_size_t actualBytesToCopy = min(withLength, _capacity - _length);
assert(_length <= _capacity);
-
- offset = _length;
+ bcopy(/* from */ bytes, (void *)(_singleRange.v.address + _length),
+ actualBytesToCopy);
_length += actualBytesToCopy;
- _ranges.v64->length += actualBytesToCopy;
-
- if (_task == kernel_task)
- bcopy(/* from */ bytes, (void *)(_ranges.v64->address + offset),
- actualBytesToCopy);
- else
- writeBytes(offset, bytes, actualBytesToCopy);
+ _singleRange.v.length += actualBytesToCopy;
return true;
}
@@ -554,12 +422,8 @@
*/
void * IOBufferMemoryDescriptor::getBytesNoCopy()
{
- if (kIOMemoryTypePhysical64 == (_flags & kIOMemoryTypeMask))
- return _buffer;
- else
- return (void *)_ranges.v64->address;
-}
-
+ return (void *)_singleRange.v.address;
+}
/*
* getBytesNoCopy:
@@ -569,37 +433,62 @@
void *
IOBufferMemoryDescriptor::getBytesNoCopy(vm_size_t start, vm_size_t withLength)
{
- IOVirtualAddress address;
- if (kIOMemoryTypePhysical64 == (_flags & kIOMemoryTypeMask))
- address = (IOVirtualAddress) _buffer;
- else
- address = _ranges.v64->address;
-
- if (start < _length && (start + withLength) <= _length)
- return (void *)(address + start);
+ if (start < _length && (start + withLength) <= _length)
+ return (void *)(_singleRange.v.address + start);
return 0;
}
-#ifndef __LP64__
-void * IOBufferMemoryDescriptor::getVirtualSegment(IOByteCount offset,
- IOByteCount * lengthOfSegment)
-{
- void * bytes = getBytesNoCopy(offset, 0);
-
- if (bytes && lengthOfSegment)
- *lengthOfSegment = _length - offset;
-
- return bytes;
-}
-#endif /* !__LP64__ */
-
-#ifdef __LP64__
-OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 0);
+/*
+ * getPhysicalSegment:
+ *
+ * Get the physical address of the buffer, relative to the current position.
+ * If the current position is at the end of the buffer, a zero is returned.
+ */
+IOPhysicalAddress
+IOBufferMemoryDescriptor::getPhysicalSegment(IOByteCount offset,
+ IOByteCount * lengthOfSegment)
+{
+ IOPhysicalAddress physAddr;
+
+ if( offset != _position)
+ setPosition( offset );
+
+ assert(_position <= _length);
+
+ /* Fail gracefully if the position is at (or past) the end-of-buffer. */
+ if (_position >= _length) {
+ *lengthOfSegment = 0;
+ return 0;
+ }
+
+ if (_options & kIOMemoryPageable) {
+ physAddr = super::getPhysicalSegment(offset, lengthOfSegment);
+
+ } else {
+ /* Compute the largest contiguous physical length possible. */
+ vm_address_t actualPos = _singleRange.v.address + _position;
+ vm_address_t actualPage = trunc_page(actualPos);
+ unsigned physInd = atop(actualPage-trunc_page(_singleRange.v.address));
+
+ vm_size_t physicalLength = actualPage + page_size - actualPos;
+ for (unsigned index = physInd + 1; index < _physSegCount &&
+ _physAddrs[index] == _physAddrs[index-1] + page_size; index++) {
+ physicalLength += page_size;
+ }
+
+ /* Clip contiguous physical length at the end-of-buffer. */
+ if (physicalLength > _length - _position)
+ physicalLength = _length - _position;
+
+ *lengthOfSegment = physicalLength;
+ physAddr = _physAddrs[physInd] + (actualPos - actualPage);
+ }
+
+ return physAddr;
+}
+
+OSMetaClassDefineReservedUsed(IOBufferMemoryDescriptor, 0);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 1);
-#else /* !__LP64__ */
-OSMetaClassDefineReservedUsed(IOBufferMemoryDescriptor, 0);
-OSMetaClassDefineReservedUsed(IOBufferMemoryDescriptor, 1);
-#endif /* !__LP64__ */
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 2);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 3);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 4);