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   SPDX-License-Identifier: BSD-2-Clause-Patent
  31
  32 **/
  33
  34 #ifndef __DMA_LIB_H__
  35 #define __DMA_LIB_H__
  36
  37 typedef enum {
  38   ///
  39   /// A read operation from system memory by a bus master.
  40   ///
  41   MapOperationBusMasterRead,
  42   ///
  43   /// A write operation from system memory by a bus master.
  44   ///
  45   MapOperationBusMasterWrite,
  46   ///
  47   /// Provides both read and write access to system memory by both the processor and a
  48   /// bus master. The buffer is coherent from both the processor's and the bus master's point of view.
  49   ///
  50   MapOperationBusMasterCommonBuffer,
  51   MapOperationMaximum
  52 } DMA_MAP_OPERATION;
  53
  54
  55
  56
  57 /**
  58   Provides the DMA controller-specific addresses needed to access system memory.
  59
  60   Operation is relative to the DMA bus master.
  61
  62   @param  Operation             Indicates if the bus master is going to read or write to system memory.
  63   @param  HostAddress           The system memory address to map to the DMA controller.
  64   @param  NumberOfBytes         On input the number of bytes to map. On output the number of bytes
  65                                 that were mapped.
  66   @param  DeviceAddress         The resulting map address for the bus master controller to use to
  67                                 access the hosts HostAddress.
  68   @param  Mapping               A resulting value to pass to DmaUnmap().
  69
  70   @retval EFI_SUCCESS           The range was mapped for the returned NumberOfBytes.
  71   @retval EFI_UNSUPPORTED       The HostAddress cannot be mapped as a common buffer.
  72   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
  73   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.
  74   @retval EFI_DEVICE_ERROR      The system hardware could not map the requested address.
  75
  76 **/
  77 EFI_STATUS
  78 EFIAPI
  79 DmaMap (
  80   IN     DMA_MAP_OPERATION              Operation,
  81   IN     VOID                           *HostAddress,
  82   IN OUT UINTN                          *NumberOfBytes,
  83   OUT    PHYSICAL_ADDRESS               *DeviceAddress,
  84   OUT    VOID                           **Mapping
  85   );
  86
  87
  88
  89
  90 /**
  91   Completes the DmaMapBusMasterRead, DmaMapBusMasterWrite, or DmaMapBusMasterCommonBuffer
  92   operation and releases any corresponding resources.
  93
  94   @param  Mapping               The mapping value returned from DmaMap().
  95
  96   @retval EFI_SUCCESS           The range was unmapped.
  97   @retval EFI_DEVICE_ERROR      The data was not committed to the target system memory.
  98
  99 **/
 100 EFI_STATUS
 101 EFIAPI
 102 DmaUnmap (
 103   IN  VOID                         *Mapping
 104   );
 105
 106
 107 /**
 108   Allocates pages that are suitable for an DmaMap() of type MapOperationBusMasterCommonBuffer.
 109   mapping.
 110
 111   @param  MemoryType            The type of memory to allocate, EfiBootServicesData or
 112                                 EfiRuntimeServicesData.
 113   @param  Pages                 The number of pages to allocate.
 114   @param  HostAddress           A pointer to store the base system memory address of the
 115                                 allocated range.
 116
 117                                 @retval EFI_SUCCESS           The requested memory pages were allocated.
 118   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
 119                                 MEMORY_WRITE_COMBINE and MEMORY_CACHED.
 120   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
 121   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 122
 123 **/
 124 EFI_STATUS
 125 EFIAPI
 126 DmaAllocateBuffer (
 127   IN  EFI_MEMORY_TYPE              MemoryType,
 128   IN  UINTN                        Pages,
 129   OUT VOID                         **HostAddress
 130   );
 131
 132
 133 /**
 134   Frees memory that was allocated with DmaAllocateBuffer().
 135
 136   @param  Pages                 The number of pages to free.
 137   @param  HostAddress           The base system memory address of the allocated range.
 138
 139   @retval EFI_SUCCESS           The requested memory pages were freed.
 140   @retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and Pages
 141                                 was not allocated with DmaAllocateBuffer().
 142
 143 **/
 144 EFI_STATUS
 145 EFIAPI
 146 DmaFreeBuffer (
 147   IN  UINTN                        Pages,
 148   IN  VOID                         *HostAddress
 149   );
 150
 151
 152 /**
 153   Allocates pages that are suitable for an DmaMap() of type
 154   MapOperationBusMasterCommonBuffer mapping, at the requested alignment.
 155
 156   @param  MemoryType            The type of memory to allocate, EfiBootServicesData or
 157                                 EfiRuntimeServicesData.
 158   @param  Pages                 The number of pages to allocate.
 159   @param  Alignment             Alignment in bytes of the base of the returned
 160                                 buffer (must be a power of 2)
 161   @param  HostAddress           A pointer to store the base system memory address of the
 162                                 allocated range.
 163
 164   @retval EFI_SUCCESS           The requested memory pages were allocated.
 165   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
 166                                 MEMORY_WRITE_COMBINE and MEMORY_CACHED.
 167   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
 168   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 169
 170 **/
 171 EFI_STATUS
 172 EFIAPI
 173 DmaAllocateAlignedBuffer (
 174   IN  EFI_MEMORY_TYPE              MemoryType,
 175   IN  UINTN                        Pages,
 176   IN  UINTN                        Alignment,
 177   OUT VOID                         **HostAddress
 178   );
 179
 180
 181 #endif