iokit/IOKit/IODeviceMemory.h

   1 /*
   2  * Copyright (c) 1998-2016 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  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
  30  *
  31  * HISTORY
  32  *
  33  */
  34
  35 #ifndef _IOKIT_IODEVICEMEMORY_H
  36 #define _IOKIT_IODEVICEMEMORY_H
  37
  38 #include <IOKit/IOMemoryDescriptor.h>
  39
  40 /*! @class IODeviceMemory
  41  *   @abstract An IOMemoryDescriptor used for device physical memory ranges.
  42  *   @discussion The IODeviceMemory class is a simple subclass of IOMemoryDescriptor that uses its methods to describe a single range of physical memory on a device. IODeviceMemory objects are usually looked up with IOService or IOPCIDevice accessors, and are created by memory-mapped bus families. IODeviceMemory implements only some factory methods in addition to the methods of IOMemoryDescriptor.
  43  */
  44
  45 class IODeviceMemory : public IOMemoryDescriptor
  46 {
  47         OSDeclareDefaultStructors(IODeviceMemory)
  48
  49 public:
  50
  51 /*! @struct InitElement
  52  *   @field start First physical address in the range.
  53  *   @field length Length of the range.
  54  *   @field tag 32-bit value not interpreted by IODeviceMemory or IOMemoryDescriptor, for use by the bus family. */
  55
  56         struct InitElement {
  57                 IOPhysicalAddress       start;
  58                 IOPhysicalLength        length;
  59                 IOOptionBits            tag;
  60         };
  61
  62 /*! @function arrayFromList
  63  *   @abstract Constructs an OSArray of IODeviceMemory instances, each describing one physical range, and a tag value.
  64  *   @discussion This method creates IODeviceMemory instances for each physical range passed in an IODeviceMemory::InitElement array. Each element consists of a physical address, length and tag value for the IODeviceMemory. The instances are returned as a created OSArray.
  65  *   @param list An array of IODeviceMemory::InitElement structures.
  66  *   @param count The number of elements in the list.
  67  *   @result Returns a created OSArray of IODeviceMemory objects, to be released by the caller, or zero on failure. */
  68
  69         static OSArray *            arrayFromList(
  70                 InitElement             list[],
  71                 IOItemCount             count );
  72
  73 /*! @function withRange
  74  *   @abstract Constructs an IODeviceMemory instance, describing one physical range.
  75  *   @discussion This method creates an IODeviceMemory instance for one physical range passed as a physical address and length. It just calls IOMemoryDescriptor::withPhysicalAddress.
  76  *   @param start The physical address of the first byte in the memory.
  77  *   @param length The length of memory.
  78  *   @result Returns the created IODeviceMemory on success, to be released by the caller, or zero on failure. */
  79
  80         static IODeviceMemory *     withRange(
  81                 IOPhysicalAddress       start,
  82                 IOPhysicalLength        length );
  83
  84 /*! @function withSubRange
  85  *   @abstract Constructs an IODeviceMemory instance, describing a subset of an existing IODeviceMemory range.
  86  *   @discussion This method creates an IODeviceMemory instance for a subset of an existing IODeviceMemory range, passed as a physical address offset and length. It just calls IOMemoryDescriptor::withSubRange.
  87  *   @param of The parent IODeviceMemory of which a subrange is to be used for the new descriptor, which will be retained by the subrange IODeviceMemory.
  88  *   @param offset A byte offset into the parent's memory.
  89  *   @param length The length of the subrange.
  90  *   @result Returns the created IODeviceMemory on success, to be released by the caller, or zero on failure. */
  91
  92         static IODeviceMemory *     withSubRange(
  93                 IODeviceMemory *        of,
  94                 IOPhysicalAddress       offset,
  95                 IOPhysicalLength        length );
  96 };
  97
  98 #endif /* ! _IOKIT_IODEVICEMEMORY_H */