+/** @file
+ DMA abstraction library APIs. Based on UEFI PCI IO protocol DMA abstractions.
+ At some point these functions will probably end up in a non PCI protocol
+ for embedded systems.
+
+ DMA Bus Master Read Operation:\r
+ Call DmaMap() for MapOperationBusMasterRead.
+ Program the DMA Bus Master with the DeviceAddress returned by DmaMap().
+ Start the DMA Bus Master.
+ Wait for DMA Bus Master to complete the read operation.
+ Call DmaUnmap().
+
+ DMA Bus Master Write Operation:
+ Call DmaMap() for MapOperationBusMasterWrite.\r
+ Program the DMA Bus Master with the DeviceAddress returned by DmaMap().\r
+ Start the DMA Bus Master.\r
+ Wait for DMA Bus Master to complete the write operation.\r
+ Call DmaUnmap().
+
+ DMA Bus Master Common Buffer Operation:
+ Call DmaAllocateBuffer() to allocate a common buffer.
+ Call DmaMap() for MapOperationBusMasterCommonBuffer.
+ Program the DMA Bus Master with the DeviceAddress returned by DmaMap().
+ The common buffer can now be accessed equally by the processor and the DMA bus master.
+ Call DmaUnmap().
+ Call DmaFreeBuffer().
+
+ Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
+
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef __DMA_LIB_H__
+#define __DMA_LIB_H__
+
+typedef enum {\r
+ ///\r
+ /// A read operation from system memory by a bus master.\r
+ ///\r
+ MapOperationBusMasterRead,\r
+ ///\r
+ /// A write operation from system memory by a bus master.\r
+ ///\r
+ MapOperationBusMasterWrite,\r
+ ///\r
+ /// Provides both read and write access to system memory by both the processor and a\r
+ /// bus master. The buffer is coherent from both the processor's and the bus master's point of view.\r
+ ///\r
+ MapOperationBusMasterCommonBuffer,\r
+ MapOperationMaximum\r
+} DMA_MAP_OPERATION;\r
+
+
+
+
+/** \r
+ Provides the DMA controller-specific addresses needed to access system memory.\r
+ \r
+ Operation is relative to the DMA bus master.\r
+ \r
+ @param Operation Indicates if the bus master is going to read or write to system memory.\r
+ @param HostAddress The system memory address to map to the DMA controller.\r
+ @param NumberOfBytes On input the number of bytes to map. On output the number of bytes\r
+ that were mapped. \r
+ @param DeviceAddress The resulting map address for the bus master controller to use to\r
+ access the hosts HostAddress. \r
+ @param Mapping A resulting value to pass to DmaUnmap().\r
+ \r
+ @retval EFI_SUCCESS The range was mapped for the returned NumberOfBytes.\r
+ @retval EFI_UNSUPPORTED The HostAddress cannot be mapped as a common buffer. \r
+ @retval EFI_INVALID_PARAMETER One or more parameters are invalid.\r
+ @retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.\r
+ @retval EFI_DEVICE_ERROR The system hardware could not map the requested address.\r
+ \r
+**/
+EFI_STATUS
+EFIAPI
+DmaMap (
+ IN DMA_MAP_OPERATION Operation,
+ IN VOID *HostAddress,\r
+ IN OUT UINTN *NumberOfBytes,\r
+ OUT PHYSICAL_ADDRESS *DeviceAddress,\r
+ OUT VOID **Mapping\r
+ );
+
+
+
+
+/** \r
+ Completes the DmaMapBusMasterRead, DmaMapBusMasterWrite, or DmaMapBusMasterCommonBuffer\r
+ operation and releases any corresponding resources.\r
+ \r
+ @param Mapping The mapping value returned from DmaMap().\r
+ \r
+ @retval EFI_SUCCESS The range was unmapped.\r
+ @retval EFI_DEVICE_ERROR The data was not committed to the target system memory.\r
+ \r
+**/
+EFI_STATUS
+EFIAPI
+DmaUnmap (
+ IN VOID *Mapping\r
+ );
+
+
+/** \r
+ Allocates pages that are suitable for an DmaMap() of type MapOperationBusMasterCommonBuffer.\r
+ mapping. \r
+ \r
+ @param MemoryType The type of memory to allocate, EfiBootServicesData or\r
+ EfiRuntimeServicesData. \r
+ @param Pages The number of pages to allocate. \r
+ @param HostAddress A pointer to store the base system memory address of the\r
+ allocated range. \r
+\r
+ @retval EFI_SUCCESS The requested memory pages were allocated.\r
+ @retval EFI_UNSUPPORTED Attributes is unsupported. The only legal attribute bits are\r
+ MEMORY_WRITE_COMBINE and MEMORY_CACHED. \r
+ @retval EFI_INVALID_PARAMETER One or more parameters are invalid.\r
+ @retval EFI_OUT_OF_RESOURCES The memory pages could not be allocated. \r
+ \r
+**/
+EFI_STATUS
+EFIAPI
+DmaAllocateBuffer (
+ IN EFI_MEMORY_TYPE MemoryType,
+ IN UINTN Pages,\r
+ OUT VOID **HostAddress\r
+ );\r
+
+
+/** \r
+ Frees memory that was allocated with DmaAllocateBuffer().\r
+ \r
+ @param Pages The number of pages to free. \r
+ @param HostAddress The base system memory address of the allocated range. \r
+ \r
+ @retval EFI_SUCCESS The requested memory pages were freed.\r
+ @retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and Pages\r
+ was not allocated with DmaAllocateBuffer().\r
+ \r
+**/\r
+EFI_STATUS
+EFIAPI
+DmaFreeBuffer (
+ IN UINTN Pages,\r
+ IN VOID *HostAddress\r
+ );\r
+
+
+#endif
+
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