This is xnu-11215.1.10. See this file in:
/*
* 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
* 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@
*/
#define IOKIT_ENABLE_SHARED_PTR
#define _IOMEMORYDESCRIPTOR_INTERNAL_
#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 <mach/mach_vm.h>
#include <vm/vm_kern_xnu.h>
#include "IOKitKernelInternal.h"
#ifdef IOALLOCDEBUG
#include <libkern/c++/OSCPPDebug.h>
#endif
#include <IOKit/IOStatisticsPrivate.h>
#if IOKITSTATS
#define IOStatisticsAlloc(type, size) \
do { \
IOStatistics::countAlloc(type, size); \
} while (0)
#else
#define IOStatisticsAlloc(type, size)
#endif /* IOKITSTATS */
__BEGIN_DECLS
void ipc_port_release_send(ipc_port_t port);
#include <vm/pmap.h>
KALLOC_HEAP_DEFINE(KHEAP_IOBMD_CONTROL, "IOBMD_control", KHEAP_ID_KT_VAR);
__END_DECLS
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
enum{
kInternalFlagPhysical = 0x00000001,
kInternalFlagPageSized = 0x00000002,
kInternalFlagPageAllocated = 0x00000004,
kInternalFlagInit = 0x00000008,
kInternalFlagHasPointers = 0x00000010,
kInternalFlagGuardPages = 0x00000020,
};
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#define super IOGeneralMemoryDescriptor
OSDefineMetaClassAndStructorsWithZone(IOBufferMemoryDescriptor,
IOGeneralMemoryDescriptor, ZC_ZFREE_CLEARMEM);
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#if defined(__x86_64__)
static uintptr_t
IOBMDPageProc(kalloc_heap_t kheap, iopa_t * a)
{
kern_return_t kr;
vm_address_t vmaddr = 0;
kma_flags_t kma_flags = KMA_ZERO;
if (kheap == KHEAP_DATA_BUFFERS) {
kma_flags = (kma_flags_t) (kma_flags | KMA_DATA);
}
kr = kmem_alloc(kernel_map, &vmaddr, page_size,
kma_flags, VM_KERN_MEMORY_IOKIT);
if (KERN_SUCCESS != kr) {
vmaddr = 0;
}
return (uintptr_t) vmaddr;
}
#endif /* defined(__x86_64__) */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#ifndef __LP64__
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__ */
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::withCopy(
task_t inTask,
IOOptionBits options,
vm_map_t sourceMap,
mach_vm_address_t source,
mach_vm_size_t size)
{
OSSharedPtr<IOBufferMemoryDescriptor> inst;
kern_return_t err;
vm_map_copy_t copy;
vm_map_address_t address;
copy = NULL;
do {
err = kIOReturnNoMemory;
inst = OSMakeShared<IOBufferMemoryDescriptor>();
if (!inst) {
break;
}
inst->_ranges.v64 = IOMallocType(IOAddressRange);
err = vm_map_copyin(sourceMap, source, size,
false /* src_destroy */, ©);
if (KERN_SUCCESS != err) {
break;
}
err = vm_map_copyout(get_task_map(inTask), &address, copy);
if (KERN_SUCCESS != err) {
break;
}
copy = NULL;
inst->_ranges.v64->address = address;
inst->_ranges.v64->length = size;
if (!inst->initWithPhysicalMask(inTask, options, size, page_size, 0)) {
err = kIOReturnError;
}
} while (false);
if (KERN_SUCCESS == err) {
return inst;
}
if (copy) {
vm_map_copy_discard(copy);
}
return nullptr;
}
bool
IOBufferMemoryDescriptor::initWithPhysicalMask(
task_t inTask,
IOOptionBits options,
mach_vm_size_t capacity,
mach_vm_address_t alignment,
mach_vm_address_t physicalMask)
{
task_t mapTask = NULL;
kalloc_heap_t kheap = KHEAP_DATA_BUFFERS;
mach_vm_address_t highestMask = 0;
IOOptionBits iomdOptions = kIOMemoryTypeVirtual64 | kIOMemoryAsReference;
IODMAMapSpecification mapSpec;
bool mapped = false;
bool withCopy = false;
bool mappedOrShared = false;
if (!capacity) {
return false;
}
/*
* The IOKit constructor requests the allocator for zeroed memory
* so the members of the class do not need to be explicitly zeroed.
*/
_options = options;
_capacity = capacity;
if (!_ranges.v64) {
_ranges.v64 = IOMallocType(IOAddressRange);
_ranges.v64->address = 0;
_ranges.v64->length = 0;
} else {
if (!_ranges.v64->address) {
return false;
}
if (!(kIOMemoryPageable & options)) {
return false;
}
if (!inTask) {
return false;
}
_buffer = (void *) _ranges.v64->address;
withCopy = true;
}
/*
* Set kalloc_heap to KHEAP_IOBMD_CONTROL if allocation contains pointers
*/
if (kInternalFlagHasPointers & _internalFlags) {
kheap = KHEAP_IOBMD_CONTROL;
}
// 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 (!(kIOMemoryMapperNone & options)) {
IOMapper::checkForSystemMapper();
mapped = (NULL != IOMapper::gSystem);
}
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) {
if (round_page_overflow(capacity, &capacity)) {
return false;
}
}
if (alignment > page_size) {
options |= kIOMemoryPhysicallyContiguous;
}
_alignment = alignment;
if ((capacity + alignment) < _capacity) {
return false;
}
if ((inTask != kernel_task) && !(options & kIOMemoryPageable)) {
return false;
}
bzero(&mapSpec, sizeof(mapSpec));
mapSpec.alignment = _alignment;
mapSpec.numAddressBits = 64;
if (highestMask && mapped) {
if (highestMask <= 0xFFFFFFFF) {
mapSpec.numAddressBits = (uint8_t)(32 - __builtin_clz((unsigned int) highestMask));
} else {
mapSpec.numAddressBits = (uint8_t)(64 - __builtin_clz((unsigned int) (highestMask >> 32)));
}
highestMask = 0;
}
// set memory entry cache mode, pageable, purgeable
iomdOptions |= ((options & kIOMapCacheMask) >> kIOMapCacheShift) << kIOMemoryBufferCacheShift;
if (options & kIOMemoryPageable) {
if (_internalFlags & kInternalFlagGuardPages) {
printf("IOBMD: Unsupported use of guard pages with pageable memory.\n");
return false;
}
iomdOptions |= kIOMemoryBufferPageable;
if (options & kIOMemoryPurgeable) {
iomdOptions |= kIOMemoryBufferPurgeable;
}
} else {
// 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. */
bool contig = (0 != (options & kIOMemoryHostPhysicallyContiguous));
if (!contig && (0 != (options & kIOMemoryPhysicallyContiguous))) {
contig |= (!mapped);
contig |= (0 != (kIOMemoryMapperNone & options));
#if 0
// treat kIOMemoryPhysicallyContiguous as kIOMemoryHostPhysicallyContiguous for now
contig |= true;
#endif
}
mappedOrShared = (mapped || (0 != (kIOMemorySharingTypeMask & options)));
if (contig || highestMask || (alignment > page_size)) {
if (_internalFlags & kInternalFlagGuardPages) {
printf("IOBMD: Unsupported use of guard pages with physical mask or contiguous memory.\n");
return false;
}
_internalFlags |= kInternalFlagPhysical;
if (highestMask) {
_internalFlags |= kInternalFlagPageSized;
if (round_page_overflow(capacity, &capacity)) {
return false;
}
}
_buffer = (void *) IOKernelAllocateWithPhysicalRestrict(kheap,
capacity, highestMask, alignment, contig);
} else if (_internalFlags & kInternalFlagGuardPages) {
vm_offset_t address = 0;
kern_return_t kr;
uintptr_t alignMask;
kma_flags_t kma_flags = (kma_flags_t) (KMA_GUARD_FIRST |
KMA_GUARD_LAST | KMA_ZERO);
if (((uint32_t) alignment) != alignment) {
return false;
}
if (kheap == KHEAP_DATA_BUFFERS) {
kma_flags = (kma_flags_t) (kma_flags | KMA_DATA);
}
alignMask = (1UL << log2up((uint32_t) alignment)) - 1;
kr = kernel_memory_allocate(kernel_map, &address,
capacity + page_size * 2, alignMask, kma_flags,
IOMemoryTag(kernel_map));
if (kr != KERN_SUCCESS || address == 0) {
return false;
}
#if IOALLOCDEBUG
OSAddAtomicLong(capacity, &debug_iomalloc_size);
#endif
IOStatisticsAlloc(kIOStatisticsMallocAligned, capacity);
_buffer = (void *)(address + page_size);
#if defined(__x86_64__)
} else if (mappedOrShared
&& (capacity + alignment) <= (page_size - gIOPageAllocChunkBytes)) {
_internalFlags |= kInternalFlagPageAllocated;
_buffer = (void *) iopa_alloc(&gIOBMDPageAllocator,
&IOBMDPageProc, kheap, capacity, alignment);
if (_buffer) {
bzero(_buffer, capacity);
IOStatisticsAlloc(kIOStatisticsMallocAligned, capacity);
#if IOALLOCDEBUG
OSAddAtomicLong(capacity, &debug_iomalloc_size);
#endif
}
#endif /* defined(__x86_64__) */
} else if (alignment > 1) {
/* BEGIN IGNORE CODESTYLE */
__typed_allocators_ignore_push
_buffer = IOMallocAligned_internal(kheap, capacity, alignment,
Z_ZERO_VM_TAG_BT_BIT);
} else {
_buffer = IOMalloc_internal(kheap, capacity, Z_ZERO_VM_TAG_BT_BIT);
__typed_allocators_ignore_pop
/* END IGNORE CODESTYLE */
}
if (!_buffer) {
return false;
}
}
if ((options & (kIOMemoryPageable | kIOMapCacheMask))) {
vm_size_t size = round_page(capacity);
// initWithOptions will create memory entry
if (!withCopy) {
iomdOptions |= kIOMemoryPersistent;
}
if (options & kIOMemoryPageable) {
#if IOALLOCDEBUG
OSAddAtomicLong(size, &debug_iomallocpageable_size);
#endif
if (!withCopy) {
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) {
UInt8 dummyVar = *startAddr;
(void) dummyVar;
startAddr += page_size;
}
}
}
_ranges.v64->address = (mach_vm_address_t) pgz_decode(_buffer, _capacity);
_ranges.v64->length = _capacity;
if (!super::initWithOptions(_ranges.v64, 1, 0,
inTask, iomdOptions, /* System mapper */ NULL)) {
return false;
}
_internalFlags |= kInternalFlagInit;
#if IOTRACKING
if (!(options & kIOMemoryPageable)) {
trackingAccumSize(capacity);
}
#endif /* IOTRACKING */
// give any system mapper the allocation params
if (kIOReturnSuccess != dmaCommandOperation(kIOMDAddDMAMapSpec,
&mapSpec, sizeof(mapSpec))) {
return false;
}
if (mapTask) {
if (!reserved) {
reserved = IOMallocType(ExpansionData);
if (!reserved) {
return false;
}
}
reserved->map = createMappingInTask(mapTask, 0,
kIOMapAnywhere | (options & kIOMapPrefault) | (options & kIOMapCacheMask), 0, 0).detach();
if (!reserved->map) {
_buffer = NULL;
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);
return true;
}
bool
IOBufferMemoryDescriptor::initControlWithPhysicalMask(
task_t inTask,
IOOptionBits options,
mach_vm_size_t capacity,
mach_vm_address_t alignment,
mach_vm_address_t physicalMask)
{
_internalFlags = kInternalFlagHasPointers;
return initWithPhysicalMask(inTask, options, capacity, alignment,
physicalMask);
}
bool
IOBufferMemoryDescriptor::initWithGuardPages(
task_t inTask,
IOOptionBits options,
mach_vm_size_t capacity)
{
mach_vm_size_t roundedCapacity;
_internalFlags = kInternalFlagGuardPages;
if (round_page_overflow(capacity, &roundedCapacity)) {
return false;
}
return initWithPhysicalMask(inTask, options, roundedCapacity, page_size,
(mach_vm_address_t)0);
}
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::inTaskWithOptions(
task_t inTask,
IOOptionBits options,
vm_size_t capacity,
vm_offset_t alignment)
{
OSSharedPtr<IOBufferMemoryDescriptor> me = OSMakeShared<IOBufferMemoryDescriptor>();
if (me && !me->initWithPhysicalMask(inTask, options, capacity, alignment, 0)) {
me.reset();
}
return me;
}
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::inTaskWithOptions(
task_t inTask,
IOOptionBits options,
vm_size_t capacity,
vm_offset_t alignment,
uint32_t kernTag,
uint32_t userTag)
{
OSSharedPtr<IOBufferMemoryDescriptor> me = OSMakeShared<IOBufferMemoryDescriptor>();
if (me) {
me->setVMTags(kernTag, userTag);
if (!me->initWithPhysicalMask(inTask, options, capacity, alignment, 0)) {
me.reset();
}
}
return me;
}
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::inTaskWithPhysicalMask(
task_t inTask,
IOOptionBits options,
mach_vm_size_t capacity,
mach_vm_address_t physicalMask)
{
OSSharedPtr<IOBufferMemoryDescriptor> me = OSMakeShared<IOBufferMemoryDescriptor>();
if (me && !me->initWithPhysicalMask(inTask, options, capacity, 1, physicalMask)) {
me.reset();
}
return me;
}
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::inTaskWithGuardPages(
task_t inTask,
IOOptionBits options,
mach_vm_size_t capacity)
{
OSSharedPtr<IOBufferMemoryDescriptor> me = OSMakeShared<IOBufferMemoryDescriptor>();
if (me && !me->initWithGuardPages(inTask, options, capacity)) {
me.reset();
}
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__ */
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::withOptions(
IOOptionBits options,
vm_size_t capacity,
vm_offset_t alignment)
{
OSSharedPtr<IOBufferMemoryDescriptor> me = OSMakeShared<IOBufferMemoryDescriptor>();
if (me && !me->initWithPhysicalMask(kernel_task, options, capacity, alignment, 0)) {
me.reset();
}
return me;
}
/*
* withCapacity:
*
* Returns a new IOBufferMemoryDescriptor with a buffer large enough to
* hold capacity bytes. The descriptor's length is initially set to the capacity.
*/
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::withCapacity(vm_size_t inCapacity,
IODirection inDirection,
bool inContiguous)
{
return IOBufferMemoryDescriptor::withOptions(
inDirection | kIOMemoryUnshared
| (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
inCapacity, inContiguous ? inCapacity : 1 );
}
#ifndef __LP64__
/*
* initWithBytes:
*
* Initialize a new IOBufferMemoryDescriptor preloaded with bytes (copied).
* The descriptor's length and capacity are set to the input buffer's size.
*/
bool
IOBufferMemoryDescriptor::initWithBytes(const void * inBytes,
vm_size_t inLength,
IODirection inDirection,
bool inContiguous)
{
if (!initWithPhysicalMask(kernel_task, inDirection | kIOMemoryUnshared
| (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
inLength, inLength, (mach_vm_address_t)0)) {
return false;
}
// start out with no data
setLength(0);
if (!appendBytes(inBytes, inLength)) {
return false;
}
return true;
}
#endif /* !__LP64__ */
/*
* withBytes:
*
* Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
* The descriptor's length and capacity are set to the input buffer's size.
*/
OSSharedPtr<IOBufferMemoryDescriptor>
IOBufferMemoryDescriptor::withBytes(const void * inBytes,
vm_size_t inLength,
IODirection inDirection,
bool inContiguous)
{
OSSharedPtr<IOBufferMemoryDescriptor> me = OSMakeShared<IOBufferMemoryDescriptor>();
mach_vm_address_t alignment;
alignment = (inLength <= page_size) ? inLength : page_size;
if (me && !me->initWithPhysicalMask(
kernel_task, inDirection | kIOMemoryUnshared
| (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
inLength, alignment, 0 )) {
me.reset();
}
if (me) {
// start out with no data
me->setLength(0);
if (!me->appendBytes(inBytes, inLength)) {
me.reset();
}
}
return me;
}
/*
* free:
*
* Free resources
*/
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 = NULL;
IOAddressRange * range = _ranges.v64;
vm_offset_t alignment = _alignment;
kalloc_heap_t kheap = KHEAP_DATA_BUFFERS;
vm_size_t rsize;
if (alignment >= page_size) {
if (!round_page_overflow(size, &rsize)) {
size = rsize;
}
}
if (reserved) {
map = reserved->map;
IOFreeType(reserved, ExpansionData);
if (map) {
map->release();
}
}
if ((options & kIOMemoryPageable)
|| (kInternalFlagPageSized & internalFlags)) {
if (!round_page_overflow(size, &rsize)) {
size = rsize;
}
}
if (internalFlags & kInternalFlagHasPointers) {
kheap = KHEAP_IOBMD_CONTROL;
}
#if IOTRACKING
if (!(options & kIOMemoryPageable)
&& buffer
&& (kInternalFlagInit & _internalFlags)) {
trackingAccumSize(-size);
}
#endif /* IOTRACKING */
/* super::free may unwire - deallocate buffer afterwards */
super::free();
if (options & kIOMemoryPageable) {
#if IOALLOCDEBUG
OSAddAtomicLong(-size, &debug_iomallocpageable_size);
#endif
} else if (buffer) {
if (kInternalFlagPhysical & internalFlags) {
IOKernelFreePhysical(kheap, (mach_vm_address_t) buffer, size);
} else if (kInternalFlagPageAllocated & internalFlags) {
#if defined(__x86_64__)
uintptr_t page;
page = iopa_free(&gIOBMDPageAllocator, (uintptr_t) buffer, size);
if (page) {
kmem_free(kernel_map, page, page_size);
}
#if IOALLOCDEBUG
OSAddAtomicLong(-size, &debug_iomalloc_size);
#endif
IOStatisticsAlloc(kIOStatisticsFreeAligned, size);
#else /* !defined(__x86_64__) */
/* should be unreachable */
panic("Attempting to free IOBMD with page allocated flag");
#endif /* defined(__x86_64__) */
} else if (kInternalFlagGuardPages & internalFlags) {
vm_offset_t allocation = (vm_offset_t)buffer - page_size;
kmem_free(kernel_map, allocation, size + page_size * 2);
#if IOALLOCDEBUG
OSAddAtomicLong(-size, &debug_iomalloc_size);
#endif
IOStatisticsAlloc(kIOStatisticsFreeAligned, size);
} else if (alignment > 1) {
/* BEGIN IGNORE CODESTYLE */
__typed_allocators_ignore_push
IOFreeAligned_internal(kheap, buffer, size);
} else {
IOFree_internal(kheap, buffer, size);
__typed_allocators_ignore_pop
/* END IGNORE CODESTYLE */
}
}
if (range && (kIOMemoryAsReference & flags)) {
IOFreeType(range, IOAddressRange);
}
}
/*
* getCapacity:
*
* Get the buffer capacity
*/
vm_size_t
IOBufferMemoryDescriptor::getCapacity() const
{
return _capacity;
}
/*
* setLength:
*
* Change the buffer length of the memory descriptor. When a new buffer
* is created, the initial length of the buffer is set to be the same as
* the capacity. The length can be adjusted via setLength for a shorter
* transfer (there is no need to create more buffer descriptors when you
* can reuse an existing one, even for different transfer sizes). Note
* that the specified length must not exceed the capacity of the buffer.
*/
void
IOBufferMemoryDescriptor::setLength(vm_size_t length)
{
assert(length <= _capacity);
if (length > _capacity) {
return;
}
_length = length;
_ranges.v64->length = length;
}
/*
* setDirection:
*
* Change the direction of the transfer. This method allows one to redirect
* the descriptor's transfer direction. This eliminates the need to destroy
* and create new buffers when different transfer directions are needed.
*/
void
IOBufferMemoryDescriptor::setDirection(IODirection direction)
{
_flags = (_flags & ~kIOMemoryDirectionMask) | direction;
#ifndef __LP64__
_direction = (IODirection) (_flags & kIOMemoryDirectionMask);
#endif /* !__LP64__ */
}
/*
* appendBytes:
*
* Add some data to the end of the buffer. This method automatically
* maintains the memory descriptor buffer length. Note that appendBytes
* will not copy past the end of the memory descriptor's current capacity.
*/
bool
IOBufferMemoryDescriptor::appendBytes(const void * bytes, vm_size_t withLength)
{
vm_size_t actualBytesToCopy = min(withLength, _capacity - _length);
IOByteCount offset;
assert(_length <= _capacity);
offset = _length;
_length += actualBytesToCopy;
_ranges.v64->length += actualBytesToCopy;
if (_task == kernel_task) {
bcopy(/* from */ bytes, (void *)(_ranges.v64->address + offset),
actualBytesToCopy);
} else {
writeBytes(offset, bytes, actualBytesToCopy);
}
return true;
}
/*
* getBytesNoCopy:
*
* Return the virtual address of the beginning of the buffer
*/
void *
IOBufferMemoryDescriptor::getBytesNoCopy()
{
if (kIOMemoryTypePhysical64 == (_flags & kIOMemoryTypeMask)) {
return _buffer;
} else {
return (void *)_ranges.v64->address;
}
}
/*
* getBytesNoCopy:
*
* Return the virtual address of an offset from the beginning of the buffer
*/
void *
IOBufferMemoryDescriptor::getBytesNoCopy(vm_size_t start, vm_size_t withLength)
{
IOVirtualAddress address;
if ((start + withLength) < start) {
return NULL;
}
if (kIOMemoryTypePhysical64 == (_flags & kIOMemoryTypeMask)) {
address = (IOVirtualAddress) _buffer;
} else {
address = _ranges.v64->address;
}
if (start < _length && (start + withLength) <= _length) {
return (void *)(address + start);
}
return NULL;
}
#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);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 1);
#else /* !__LP64__ */
OSMetaClassDefineReservedUsedX86(IOBufferMemoryDescriptor, 0);
OSMetaClassDefineReservedUsedX86(IOBufferMemoryDescriptor, 1);
#endif /* !__LP64__ */
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 2);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 3);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 4);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 5);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 6);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 7);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 8);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 9);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 10);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 11);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 12);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 13);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 14);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 15);