Loading...
--- xnu/xnu-12377.101.15/iokit/IOKit/IOBufferMemoryDescriptor.h
+++ xnu/xnu-201/iokit/IOKit/IOBufferMemoryDescriptor.h
@@ -1,359 +1,224 @@
/*
- * Copyright (c) 1998-2016 Apple Inc. All rights reserved.
+ * 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@
*/
#ifndef _IOBUFFERMEMORYDESCRIPTOR_H
#define _IOBUFFERMEMORYDESCRIPTOR_H
-#include <libkern/c++/OSPtr.h>
#include <IOKit/IOMemoryDescriptor.h>
-#include <DriverKit/IOBufferMemoryDescriptor.h>
enum {
- kIOMemoryPhysicallyContiguous = 0x00000010,
- kIOMemoryPageable = 0x00000020,
- kIOMemoryPurgeable = 0x00000040,
- kIOMemoryHostPhysicallyContiguous = 0x00000080,
- kIOMemorySharingTypeMask = 0x000f0000,
- kIOMemoryUnshared = 0x00000000,
- kIOMemoryKernelUserShared = 0x00010000,
- // shared IOMemoryDescriptor options for IOBufferMemoryDescriptor:
- kIOBufferDescriptorMemoryFlags = kIOMemoryDirectionMask
-#ifdef XNU_KERNEL_PRIVATE
- | kIOMemoryAutoPrepare
-#endif
- | kIOMemoryThreadSafe
- | kIOMemoryClearEncrypt
- | kIOMemoryMapperNone
- | kIOMemoryUseReserve
+ kIOMemoryDirectionMask = 0x0000000f,
+ kIOMemoryPhysicallyContiguous = 0x00000010,
+ kIOMemoryPageable = 0x00000020,
+ kIOMemorySharingTypeMask = 0x000f0000,
+ kIOMemoryUnshared = 0x00000000,
+ kIOMemoryKernelUserShared = 0x00010000,
};
-#define _IOBUFFERMEMORYDESCRIPTOR_INTASKWITHOPTIONS_ 1
-#define _IOBUFFERMEMORYDESCRIPTOR_HOSTPHYSICALLYCONTIGUOUS_ 1
-#define IOBUFFERMEMORYDESCRIPTOR_SUPPORTS_INTASKWITHOPTIONS_TAGS 1
-/*!
- * @class IOBufferMemoryDescriptor
- * @abstract Provides a simple memory descriptor that allocates its own buffer memory.
- */
class IOBufferMemoryDescriptor : public IOGeneralMemoryDescriptor
{
- OSDeclareDefaultStructorsWithDispatch(IOBufferMemoryDescriptor);
+ OSDeclareDefaultStructors(IOBufferMemoryDescriptor);
+
+protected:
+/*! @struct ExpansionData
+ @discussion This structure will be used to expand the capablilties of this class in the future.
+ */
+ struct ExpansionData { };
+
+/*! @var reserved
+ Reserved for future use. (Internal use only) */
+ ExpansionData * reserved;
+
+protected:
+ void * _buffer;
+ vm_size_t _capacity;
+ vm_offset_t _alignment;
+ IOOptionBits _options;
+ IOPhysicalAddress * _physAddrs;
+ unsigned _physSegCount;
private:
-/*! @struct ExpansionData
- * @discussion This structure will be used to expand the capablilties of this class in the future.
- */
- struct ExpansionData {
- IOMemoryMap * map;
- };
-
-/*! @var reserved
- * Reserved for future use. (Internal use only) */
- APPLE_KEXT_WSHADOW_PUSH;
- ExpansionData * reserved;
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 0);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 1);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 4);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 5);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 6);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 7);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 8);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 9);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 10);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 11);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 12);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 13);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 14);
+ OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 15);
protected:
- void * _buffer;
- vm_size_t _capacity;
- vm_offset_t _alignment;
- IOOptionBits _options;
-private:
- uintptr_t _internalReserved;
- unsigned _internalFlags;
- APPLE_KEXT_WSHADOW_POP;
-
-private:
-#ifndef __LP64__
- virtual bool initWithOptions(
- IOOptionBits options,
- vm_size_t capacity,
- vm_offset_t alignment,
- task_t inTask) APPLE_KEXT_DEPRECATED; /* use withOptions() instead */
-#endif /* !__LP64__ */
+ virtual void free();
+
+ virtual bool initWithAddress( void * address, /* not supported */
+ IOByteCount withLength,
+ IODirection withDirection );
+
+ virtual bool initWithAddress( vm_address_t address, /* not supported */
+ IOByteCount withLength,
+ IODirection withDirection,
+ task_t withTask );
+
+ virtual bool initWithPhysicalAddress(
+ IOPhysicalAddress address, /* not supported */
+ IOByteCount withLength,
+ IODirection withDirection );
+
+ virtual bool initWithPhysicalRanges(
+ IOPhysicalRange * ranges, /* not supported */
+ UInt32 withCount,
+ IODirection withDirection,
+ bool asReference = false );
+
+ virtual bool initWithRanges( IOVirtualRange * ranges, /* not supported */
+ UInt32 withCount,
+ IODirection withDirection,
+ task_t withTask,
+ bool asReference = false );
+
+ IOGeneralMemoryDescriptor::withAddress; /* not supported */
+ IOGeneralMemoryDescriptor::withPhysicalAddress; /* not supported */
+ IOGeneralMemoryDescriptor::withPhysicalRanges; /* not supported */
+ IOGeneralMemoryDescriptor::withRanges; /* not supported */
+ IOGeneralMemoryDescriptor::withSubRange; /* not supported */
public:
- virtual bool initWithPhysicalMask(
- task_t inTask,
- IOOptionBits options,
- mach_vm_size_t capacity,
- mach_vm_address_t alignment,
- mach_vm_address_t physicalMask);
-
-#ifdef XNU_KERNEL_PRIVATE
-/*
- * By default the buffer allocated in IOBufferMemoryDescriptor is
- * considered to contain "pure data" and no kernel pointers. It
- * is therefore colocated with other data buffers.
- *
- * This API allows to create a buffer that contains pointers and
- * will not be redirected to the data heap/map.
- */
- bool initControlWithPhysicalMask(
- task_t inTask,
- IOOptionBits options,
- mach_vm_size_t capacity,
- mach_vm_address_t alignment,
- mach_vm_address_t physicalMask);
-#endif
-
-#ifdef KERNEL_PRIVATE
- /*
- * Create an IOBufferMemoryDescriptor with guard pages on each side of the buffer allocation.
- * @param inTask The task the buffer will be allocated in. Pass NULL to allocate unmapped memory.
- * @param options Options for the IOBufferMemoryDescriptor. See inTaskWithOptions for a description of available options.
- * Some options are not available when using guard pages. Specifically, physically contiguous memory and pageable memory
- * options are not supported. If these options are used, this will fail to create the memory descriptor and return NULL.
- * @param capacity The number of bytes to allocate. Due to how memory with guard pages is allocated, this will be rounded up to page size.
- * The buffer will also always be aligned to the page size.
- * @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory descriptor and associated buffer.
- */
- static OSPtr<IOBufferMemoryDescriptor> inTaskWithGuardPages(
- task_t inTask,
- IOOptionBits options,
- mach_vm_size_t capacity);
-
- bool initWithGuardPages(
- task_t inTask,
- IOOptionBits options,
- mach_vm_size_t capacity);
-#endif
-
-#ifdef __LP64__
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 0);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 1);
-#else /* !__LP64__ */
- OSMetaClassDeclareReservedUsedX86(IOBufferMemoryDescriptor, 0);
- OSMetaClassDeclareReservedUsedX86(IOBufferMemoryDescriptor, 1);
-#endif /* !__LP64__ */
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 2);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 3);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 4);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 5);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 6);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 7);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 8);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 9);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 10);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 11);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 12);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 13);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 14);
- OSMetaClassDeclareReservedUnused(IOBufferMemoryDescriptor, 15);
-
-protected:
- virtual void free() APPLE_KEXT_OVERRIDE;
-
-public:
-
-/*
- * withOptions:
- *
- * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
- * hold capacity bytes. The descriptor's length is initially set to the
- * capacity.
- */
-#ifndef __LP64__
- virtual bool initWithOptions( IOOptionBits options,
- vm_size_t capacity,
- vm_offset_t alignment) APPLE_KEXT_DEPRECATED; /* use withOptions() instead */
-#endif /* !__LP64__ */
-
- static OSPtr<IOBufferMemoryDescriptor> withCopy(
- task_t inTask,
- IOOptionBits options,
- vm_map_t sourceMap,
- mach_vm_address_t source,
- mach_vm_size_t size);
-
- static OSPtr<IOBufferMemoryDescriptor> withOptions( IOOptionBits options,
- vm_size_t capacity,
- vm_offset_t alignment = 1);
-
-/*! @function inTaskWithOptions
- * @abstract Creates a memory buffer with memory descriptor for that buffer.
- * @discussion Added in Mac OS X 10.2, this method allocates a memory buffer with a given size and alignment in the task's address space specified, and returns a memory descriptor instance representing the memory. It is recommended that memory allocated for I/O or sharing via mapping be created via IOBufferMemoryDescriptor. Options passed with the request specify the kind of memory to be allocated - pageablity and sharing are specified with option bits. This function may block and so should not be called from interrupt level or while a simple lock is held.
- * @param inTask The task the buffer will be allocated in. Pass NULL to allocate unmapped memory.
- * @param options Options for the allocation:<br>
- * kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
- * kIOMemoryPhysicallyContiguous - pass to request memory be physically contiguous. This option is heavily discouraged. The request may fail if memory is fragmented, may cause large amounts of paging activity, and may take a very long time to execute.<br>
- * kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
- * kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
- * kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.<br>
- * kIOMapInhibitCache - allocate memory with inhibited cache setting. <br>
- * kIOMapWriteThruCache - allocate memory with writethru cache setting. <br>
- * kIOMapCopybackCache - allocate memory with copyback cache setting. <br>
- * kIOMapWriteCombineCache - allocate memory with writecombined cache setting.
- * @param capacity The number of bytes to allocate.
- * @param alignment The minimum required alignment of the buffer in bytes - 1 is the default for no required alignment. For example, pass 256 to get memory allocated at an address with bits 0-7 zero.
- * @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
-
- static OSPtr<IOBufferMemoryDescriptor> inTaskWithOptions(
- task_t inTask,
- IOOptionBits options,
- vm_size_t capacity,
- vm_offset_t alignment = 1);
-
-/*! @function inTaskWithOptions
- * @abstract Creates a memory buffer with memory descriptor for that buffer.
- * @discussion Added in Mac OS X 10.2, this method allocates a memory buffer with a given size and alignment in the task's address space specified, and returns a memory descriptor instance representing the memory. It is recommended that memory allocated for I/O or sharing via mapping be created via IOBufferMemoryDescriptor. Options passed with the request specify the kind of memory to be allocated - pageablity and sharing are specified with option bits. This function may block and so should not be called from interrupt level or while a simple lock is held.
- * @param inTask The task the buffer will be allocated in. Pass NULL to allocate unmapped memory.
- * @param options Options for the allocation:<br>
- * kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
- * kIOMemoryPhysicallyContiguous - pass to request memory be physically contiguous. This option is heavily discouraged. The request may fail if memory is fragmented, may cause large amounts of paging activity, and may take a very long time to execute.<br>
- * kIOMemoryPageable - pass to request memory be non-wired - the default for kernel allocated memory is wired.<br>
- * kIOMemoryPurgeable - pass to request memory that may later have its purgeable state set with IOMemoryDescriptor::setPurgeable. Only supported for kIOMemoryPageable allocations.<br>
- * kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.<br>
- * kIOMapInhibitCache - allocate memory with inhibited cache setting. <br>
- * kIOMapWriteThruCache - allocate memory with writethru cache setting. <br>
- * kIOMapCopybackCache - allocate memory with copyback cache setting. <br>
- * kIOMapWriteCombineCache - allocate memory with writecombined cache setting.
- * @param capacity The number of bytes to allocate.
- * @param alignment The minimum required alignment of the buffer in bytes - 1 is the default for no required alignment. For example, pass 256 to get memory allocated at an address with bits 0-7 zero.
- * @param kernTag The kernel memory tag
- * @param userTag The user memory tag
- * @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
-
- static OSPtr<IOBufferMemoryDescriptor> inTaskWithOptions(
- task_t inTask,
- IOOptionBits options,
- vm_size_t capacity,
- vm_offset_t alignment,
- uint32_t kernTag,
- uint32_t userTag);
-
-/*! @function inTaskWithPhysicalMask
- * @abstract Creates a memory buffer with memory descriptor for that buffer.
- * @discussion Added in Mac OS X 10.5, this method allocates a memory buffer with a given size and alignment in the task's address space specified, and returns a memory descriptor instance representing the memory. It is recommended that memory allocated for I/O or sharing via mapping be created via IOBufferMemoryDescriptor. Options passed with the request specify the kind of memory to be allocated - pageablity and sharing are specified with option bits. This function may block and so should not be called from interrupt level or while a simple lock is held.
- * @param inTask The task the buffer will be mapped in. Pass NULL to create memory unmapped in any task (eg. for use as a DMA buffer).
- * @param options Options for the allocation:<br>
- * kIODirectionOut, kIODirectionIn - set the direction of the I/O transfer.<br>
- * kIOMemoryPhysicallyContiguous - pass to request memory be physically contiguous. This option is heavily discouraged. The request may fail if memory is fragmented, may cause large amounts of paging activity, and may take a very long time to execute.<br>
- * kIOMemoryKernelUserShared - pass to request memory that will be mapped into both the kernel and client applications.<br>
- * kIOMapInhibitCache - allocate memory with inhibited cache setting. <br>
- * kIOMapWriteThruCache - allocate memory with writethru cache setting. <br>
- * kIOMapCopybackCache - allocate memory with copyback cache setting. <br>
- * kIOMapWriteCombineCache - allocate memory with writecombined cache setting.
- * @param capacity The number of bytes to allocate.
- * @param physicalMask The buffer will be allocated with pages such that physical addresses will only have bits set present in physicalMask. For example, pass 0x00000000FFFFFFFFULL for a buffer to be accessed by hardware that has 32 address bits.
- * @result Returns an instance of class IOBufferMemoryDescriptor to be released by the caller, which will free the memory desriptor and associated buffer. */
-
- static OSPtr<IOBufferMemoryDescriptor> inTaskWithPhysicalMask(
- task_t inTask,
- IOOptionBits options,
- mach_vm_size_t capacity,
- mach_vm_address_t physicalMask);
-
-/*
- * withCapacity:
- *
- * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
- * hold capacity bytes. The descriptor's length is initially set to the
- * capacity.
- */
- static OSPtr<IOBufferMemoryDescriptor> withCapacity(
- vm_size_t capacity __xnu_data_size,
- IODirection withDirection,
- bool withContiguousMemory = false);
-#ifndef __LP64__
- virtual bool initWithBytes(const void * bytes,
- vm_size_t withLength,
- IODirection withDirection,
- bool withContiguousMemory = false) APPLE_KEXT_DEPRECATED; /* use withBytes() instead */
-#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.
- */
- static OSPtr<IOBufferMemoryDescriptor> withBytes(
- const void * bytes,
- vm_size_t withLength __xnu_data_size,
- IODirection withDirection,
- bool withContiguousMemory = false);
-
-/*
- * 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.
- */
- virtual void setLength(vm_size_t 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.
- */
- virtual void setDirection(IODirection direction);
-
-/*
- * getCapacity:
- *
- * Get the buffer capacity
- */
- virtual vm_size_t getCapacity() const;
-
-/*
- * getBytesNoCopy:
- *
- * Return the virtual address of the beginning of the buffer
- */
- __xnu_returns_data_pointer
- virtual void *getBytesNoCopy();
-
-/*
- * getBytesNoCopy:
- *
- * Return the virtual address of an offset from the beginning of the buffer
- */
- __xnu_returns_data_pointer
- virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
-
-/*
- * 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.
- */
- virtual bool appendBytes(const void *bytes, vm_size_t withLength __xnu_data_size);
-
-#ifndef __LP64__
- virtual void * getVirtualSegment(IOByteCount offset,
- IOByteCount * length) APPLE_KEXT_OVERRIDE APPLE_KEXT_DEPRECATED; /* use getBytesNoCopy() instead */
-#endif /* !__LP64__ */
+
+ /*
+ * withOptions:
+ *
+ * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
+ * hold capacity bytes. The descriptor's length is initially set to the
+ * capacity.
+ */
+ virtual bool initWithOptions( IOOptionBits options,
+ vm_size_t capacity,
+ vm_offset_t alignment);
+
+ static IOBufferMemoryDescriptor * withOptions( IOOptionBits options,
+ vm_size_t capacity,
+ vm_offset_t alignment = 1);
+
+ /*
+ * withCapacity:
+ *
+ * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
+ * hold capacity bytes. The descriptor's length is initially set to the
+ * capacity.
+ */
+ static IOBufferMemoryDescriptor * withCapacity(
+ vm_size_t capacity,
+ IODirection withDirection,
+ bool withContiguousMemory = false);
+ /*
+ * initWithBytes:
+ *
+ * Initialize a new IOBufferMemoryDescriptor preloaded with bytes (copied).
+ * The descriptor's length and capacity are set to the input buffer's size.
+ */
+ virtual bool initWithBytes(const void * bytes,
+ vm_size_t withLength,
+ IODirection withDirection,
+ bool withContiguousMemory = false);
+
+ /*
+ * withBytes:
+ *
+ * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
+ * The descriptor's length and capacity are set to the input buffer's size.
+ */
+ static IOBufferMemoryDescriptor * withBytes(
+ const void * bytes,
+ vm_size_t withLength,
+ IODirection withDirection,
+ bool withContiguousMemory = false);
+
+ /*
+ * 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.
+ */
+ virtual void setLength(vm_size_t 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.
+ */
+ virtual void setDirection(IODirection direction);
+
+ /*
+ * getCapacity:
+ *
+ * Get the buffer capacity
+ */
+ virtual vm_size_t getCapacity() const;
+
+ /*
+ * getBytesNoCopy:
+ *
+ * Return the virtual address of the beginning of the buffer
+ */
+ virtual void *getBytesNoCopy();
+
+ /*
+ * getBytesNoCopy:
+ *
+ * Return the virtual address of an offset from the beginning of the buffer
+ */
+ virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
+
+ /*
+ * 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.
+ */
+ virtual bool appendBytes(const void *bytes, vm_size_t withLength);
+
+ /*
+ * 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.
+ */
+ virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
+ IOByteCount * length);
};
#endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */