iokit/DriverKit/IOBufferMemoryDescriptor.iig

   1 /*
   2  * Copyright (c) 2019-2019 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 #if !__IIG
  30 #if KERNEL
  31 #include <IOKit/IOBufferMemoryDescriptor.h>
  32 #endif
  33 #endif
  34
  35
  36 #ifndef _IOKIT_UIOBUFFERMEMORYDESCRIPTOR_H
  37 #define _IOKIT_UIOBUFFERMEMORYDESCRIPTOR_H
  38
  39 #include <DriverKit/IOMemoryDescriptor.iig>
  40
  41 /*!
  42  * @class IOBufferMemoryDescriptor
  43  *
  44  * @abstract
  45  * IOBufferMemoryDescriptor describes a memory buffer allocated in the callers address space.
  46  *
  47  * @discussion
  48  * To allocate memory for I/O or sharing, use IOBufferMemoryDescriptor::Create()
  49  * Methods in this class are used for memory that was supplied as a parameter.
  50  * IOBufferMemoryDescriptor can be handed to any API that expects an IOMemoryDescriptor.
  51  */
  52
  53 class KERNEL IOBufferMemoryDescriptor : public IOMemoryDescriptor
  54 {
  55 public:
  56
  57     /*!
  58      * @brief       Create an IOBufferMemoryDescriptor.
  59      * @param       options Pass the flags      kIOMemoryDirectionIn, kIOMemoryDirectionOut or kIOMemoryDirectionOutIn
  60      *              to set the direction of the i/o
  61      * @param       capacity Maximum length of the memory buffer. The descriptor has no valid data
  62      *              and zero length until set with SetLength().
  63      * @param       memory Created descriptor with +1 retain count to be released by the caller.
  64      * @param       alignment For small less-than-page-size buffers, control the alignment of the memory buffer.
  65      *              Pass zero for no guaranteed alignment.
  66      * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
  67      */
  68         static kern_return_t
  69         Create(
  70                 uint64_t options,
  71                 uint64_t capacity,
  72                 uint64_t alignment,
  73                 IOBufferMemoryDescriptor ** memory);
  74
  75         virtual bool
  76         init() override;
  77
  78         virtual void
  79         free() override;
  80
  81     /*!
  82      * @brief       Obtain the address and length of the memory buffer.
  83      * @param       range An IOAddressSegment structure filled out with the address and length of the memory buffer.
  84      * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
  85      */
  86         kern_return_t
  87         GetAddressRange(IOAddressSegment * range) LOCALONLY;
  88
  89     /*!
  90      * @brief       Set the valid length of the memory buffer.
  91      * @discussion  IOBufferMemoryDescriptor have capacity allocated at Create() but no valid data until set
  92      *              with this method.
  93      * @param       length New valid length of the memory described.
  94      * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
  95      */
  96         virtual kern_return_t
  97         SetLength(uint64_t length);
  98 };
  99
 100 #endif /* ! _IOKIT_UIOBUFFERMEMORYDESCRIPTOR_H */