EmbeddedPkg/Include/Library/DmaLib.h

   1 /** @file
   2   DMA abstraction library APIs. Based on UEFI PCI IO protocol DMA abstractions.
   3   At some point these functions will probably end up in a non PCI protocol
   4   for embedded systems.
   5
   6   DMA Bus Master Read Operation:
   7     Call DmaMap() for MapOperationBusMasterRead.
   8     Program the DMA Bus Master with the DeviceAddress returned by DmaMap().
   9     Start the DMA Bus Master.
  10     Wait for DMA Bus Master to complete the read operation.
  11     Call DmaUnmap().
  12
  13   DMA Bus Master Write Operation:
  14     Call DmaMap() for MapOperationBusMasterWrite.
  15     Program the DMA Bus Master with the DeviceAddress returned by DmaMap().
  16     Start the DMA Bus Master.
  17     Wait for DMA Bus Master to complete the write operation.
  18     Call DmaUnmap().
  19
  20   DMA Bus Master Common Buffer Operation:
  21     Call DmaAllocateBuffer() to allocate a common buffer.
  22     Call DmaMap() for MapOperationBusMasterCommonBuffer.
  23     Program the DMA Bus Master with the DeviceAddress returned by DmaMap().
  24     The common buffer can now be accessed equally by the processor and the DMA bus master.
  25     Call DmaUnmap().
  26     Call DmaFreeBuffer().
  27
  28   Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
  29
  30   This program and the accompanying materials
  31   are licensed and made available under the terms and conditions of the BSD License
  32   which accompanies this distribution.  The full text of the license may be found at
  33   http://opensource.org/licenses/bsd-license.php
  34
  35   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  36   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  37
  38 **/
  39
  40 #ifndef __DMA_LIB_H__
  41 #define __DMA_LIB_H__
  42
  43 typedef enum {
  44   ///
  45   /// A read operation from system memory by a bus master.
  46   ///
  47   MapOperationBusMasterRead,
  48   ///
  49   /// A write operation from system memory by a bus master.
  50   ///
  51   MapOperationBusMasterWrite,
  52   ///
  53   /// Provides both read and write access to system memory by both the processor and a
  54   /// bus master. The buffer is coherent from both the processor's and the bus master's point of view.
  55   ///
  56   MapOperationBusMasterCommonBuffer,
  57   MapOperationMaximum
  58 } DMA_MAP_OPERATION;
  59
  60
  61
  62
  63 /**
  64   Provides the DMA controller-specific addresses needed to access system memory.
  65
  66   Operation is relative to the DMA bus master.
  67
  68   @param  Operation             Indicates if the bus master is going to read or write to system memory.
  69   @param  HostAddress           The system memory address to map to the DMA controller.
  70   @param  NumberOfBytes         On input the number of bytes to map. On output the number of bytes
  71                                 that were mapped.
  72   @param  DeviceAddress         The resulting map address for the bus master controller to use to
  73                                 access the hosts HostAddress.
  74   @param  Mapping               A resulting value to pass to DmaUnmap().
  75
  76   @retval EFI_SUCCESS           The range was mapped for the returned NumberOfBytes.
  77   @retval EFI_UNSUPPORTED       The HostAddress cannot be mapped as a common buffer.
  78   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
  79   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.
  80   @retval EFI_DEVICE_ERROR      The system hardware could not map the requested address.
  81
  82 **/
  83 EFI_STATUS
  84 EFIAPI
  85 DmaMap (
  86   IN     DMA_MAP_OPERATION              Operation,
  87   IN     VOID                           *HostAddress,
  88   IN OUT UINTN                          *NumberOfBytes,
  89   OUT    PHYSICAL_ADDRESS               *DeviceAddress,
  90   OUT    VOID                           **Mapping
  91   );
  92
  93
  94
  95
  96 /**
  97   Completes the DmaMapBusMasterRead, DmaMapBusMasterWrite, or DmaMapBusMasterCommonBuffer
  98   operation and releases any corresponding resources.
  99
 100   @param  Mapping               The mapping value returned from DmaMap().
 101
 102   @retval EFI_SUCCESS           The range was unmapped.
 103   @retval EFI_DEVICE_ERROR      The data was not committed to the target system memory.
 104
 105 **/
 106 EFI_STATUS
 107 EFIAPI
 108 DmaUnmap (
 109   IN  VOID                         *Mapping
 110   );
 111
 112
 113 /**
 114   Allocates pages that are suitable for an DmaMap() of type MapOperationBusMasterCommonBuffer.
 115   mapping.
 116
 117   @param  MemoryType            The type of memory to allocate, EfiBootServicesData or
 118                                 EfiRuntimeServicesData.
 119   @param  Pages                 The number of pages to allocate.
 120   @param  HostAddress           A pointer to store the base system memory address of the
 121                                 allocated range.
 122
 123                                 @retval EFI_SUCCESS           The requested memory pages were allocated.
 124   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
 125                                 MEMORY_WRITE_COMBINE and MEMORY_CACHED.
 126   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
 127   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 128
 129 **/
 130 EFI_STATUS
 131 EFIAPI
 132 DmaAllocateBuffer (
 133   IN  EFI_MEMORY_TYPE              MemoryType,
 134   IN  UINTN                        Pages,
 135   OUT VOID                         **HostAddress
 136   );
 137
 138
 139 /**
 140   Frees memory that was allocated with DmaAllocateBuffer().
 141
 142   @param  Pages                 The number of pages to free.
 143   @param  HostAddress           The base system memory address of the allocated range.
 144
 145   @retval EFI_SUCCESS           The requested memory pages were freed.
 146   @retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and Pages
 147                                 was not allocated with DmaAllocateBuffer().
 148
 149 **/
 150 EFI_STATUS
 151 EFIAPI
 152 DmaFreeBuffer (
 153   IN  UINTN                        Pages,
 154   IN  VOID                         *HostAddress
 155   );
 156
 157
 158 #endif
 159