[mirror_edk2.git] / ArmPkg / Library / ArmDmaLib / ArmDmaLib.c

/** @file\r
  Generic ARM implementation of DmaLib.h\r
\r
  Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>\r
  \r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include <PiDxe.h>\r
#include <Library/DebugLib.h>\r
#include <Library/DmaLib.h>\r
#include <Library/DxeServicesTableLib.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/UncachedMemoryAllocationLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/ArmLib.h>\r
\r
#include <Protocol/Cpu.h>\r
\r
typedef struct {\r
  EFI_PHYSICAL_ADDRESS      HostAddress;\r
  EFI_PHYSICAL_ADDRESS      DeviceAddress;\r
  UINTN                     NumberOfBytes;\r
  DMA_MAP_OPERATION         Operation;\r
  BOOLEAN                   DoubleBuffer;\r
} MAP_INFO_INSTANCE;\r
\r
\r
\r
EFI_CPU_ARCH_PROTOCOL      *gCpu;\r
UINTN                      gCacheAlignment = 0;\r
\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 Unmap().\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
**/\r
EFI_STATUS\r
EFIAPI\r
DmaMap (\r
  IN     DMA_MAP_OPERATION              Operation,\r
  IN     VOID                           *HostAddress,\r
  IN OUT UINTN                          *NumberOfBytes,\r
  OUT    PHYSICAL_ADDRESS               *DeviceAddress,\r
  OUT    VOID                           **Mapping\r
  )\r
{\r
  EFI_STATUS                      Status;\r
  MAP_INFO_INSTANCE               *Map;\r
  VOID                            *Buffer;\r
  EFI_GCD_MEMORY_SPACE_DESCRIPTOR GcdDescriptor;\r
\r
  if (HostAddress == NULL || NumberOfBytes == NULL || DeviceAddress == NULL || Mapping == NULL ) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (Operation >= MapOperationMaximum) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  *DeviceAddress = ConvertToPhysicalAddress (HostAddress);\r
\r
  // Remember range so we can flush on the other side\r
  Map = AllocatePool (sizeof (MAP_INFO_INSTANCE));\r
  if (Map == NULL) {\r
    return  EFI_OUT_OF_RESOURCES;\r
  }\r
  \r
  *Mapping = Map;\r
\r
  if ((((UINTN)HostAddress & (gCacheAlignment - 1)) != 0) ||\r
      ((*NumberOfBytes % gCacheAlignment) != 0)) {\r
\r
    // Get the cacheability of the region\r
    Status = gDS->GetMemorySpaceDescriptor (*DeviceAddress, &GcdDescriptor);\r
    if (EFI_ERROR(Status)) {\r
      return Status;\r
    }\r
\r
    // If the mapped buffer is not an uncached buffer\r
    if ( (GcdDescriptor.Attributes != EFI_MEMORY_WC) &&\r
         (GcdDescriptor.Attributes != EFI_MEMORY_UC) )\r
    {\r
      //\r
      // If the buffer does not fill entire cache lines we must double buffer into\r
      // uncached memory. Device (PCI) address becomes uncached page.\r
      //\r
      Map->DoubleBuffer  = TRUE;\r
      Status = DmaAllocateBuffer (EfiBootServicesData, EFI_SIZE_TO_PAGES (*NumberOfBytes), &Buffer);\r
      if (EFI_ERROR (Status)) {\r
        return Status;\r
      }\r
\r
      if ((Operation == MapOperationBusMasterRead) || (Operation == MapOperationBusMasterCommonBuffer)) {\r
        CopyMem (Buffer, HostAddress, *NumberOfBytes);\r
      }\r
\r
      *DeviceAddress = (PHYSICAL_ADDRESS)(UINTN)Buffer;\r
    } else {\r
      Map->DoubleBuffer  = FALSE;\r
    }\r
  } else {\r
    Map->DoubleBuffer  = FALSE;\r
\r
    // Flush the Data Cache (should not have any effect if the memory region is uncached)\r
    gCpu->FlushDataCache (gCpu, *DeviceAddress, *NumberOfBytes, EfiCpuFlushTypeWriteBackInvalidate);\r
\r
    if ((Operation == MapOperationBusMasterRead) || (Operation == MapOperationBusMasterCommonBuffer)) {\r
      // In case the buffer is used for instance to send command to a PCI controller, we must ensure the memory is uncached\r
      Status = gDS->SetMemorySpaceAttributes (*DeviceAddress & ~(BASE_4KB - 1), ALIGN_VALUE (*NumberOfBytes, BASE_4KB), EFI_MEMORY_WC);\r
      ASSERT_EFI_ERROR (Status);\r
    }\r
  }\r
\r
  Map->HostAddress   = (UINTN)HostAddress;\r
  Map->DeviceAddress = *DeviceAddress;\r
  Map->NumberOfBytes = *NumberOfBytes;\r
  Map->Operation     = Operation;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
\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
**/\r
EFI_STATUS\r
EFIAPI\r
DmaUnmap (\r
  IN  VOID                         *Mapping\r
  )\r
{\r
  MAP_INFO_INSTANCE *Map;\r
  \r
  if (Mapping == NULL) {\r
    ASSERT (FALSE);\r
    return EFI_INVALID_PARAMETER;\r
  }\r
  \r
  Map = (MAP_INFO_INSTANCE *)Mapping;\r
  \r
  if (Map->DoubleBuffer) {\r
    if ((Map->Operation == MapOperationBusMasterWrite) || (Map->Operation == MapOperationBusMasterCommonBuffer)) {\r
      CopyMem ((VOID *)(UINTN)Map->HostAddress, (VOID *)(UINTN)Map->DeviceAddress, Map->NumberOfBytes);\r
    }\r
    \r
    DmaFreeBuffer (EFI_SIZE_TO_PAGES (Map->NumberOfBytes), (VOID *)(UINTN)Map->DeviceAddress);\r
  \r
  } else {\r
    if (Map->Operation == MapOperationBusMasterWrite) {\r
      //\r
      // Make sure we read buffer from uncached memory and not the cache\r
      //\r
      gCpu->FlushDataCache (gCpu, Map->HostAddress, Map->NumberOfBytes, EfiCpuFlushTypeInvalidate);\r
    }\r
  }\r
  \r
  FreePool (Map);\r
\r
  return EFI_SUCCESS;\r
}\r
\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
**/\r
EFI_STATUS\r
EFIAPI\r
DmaAllocateBuffer (\r
  IN  EFI_MEMORY_TYPE              MemoryType,\r
  IN  UINTN                        Pages,\r
  OUT VOID                         **HostAddress\r
  )\r
{\r
  if (HostAddress == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // The only valid memory types are EfiBootServicesData and EfiRuntimeServicesData\r
  //\r
  // We used uncached memory to keep coherency\r
  //\r
  if (MemoryType == EfiBootServicesData) {\r
    *HostAddress = UncachedAllocatePages (Pages);\r
  } else if (MemoryType == EfiRuntimeServicesData) {\r
    *HostAddress = UncachedAllocateRuntimePages (Pages);\r
  } else {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\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\r
EFIAPI\r
DmaFreeBuffer (\r
  IN  UINTN                        Pages,\r
  IN  VOID                         *HostAddress\r
  )\r
{\r
  if (HostAddress == NULL) {\r
     return EFI_INVALID_PARAMETER;\r
  } \r
  \r
  UncachedFreePages (HostAddress, Pages);\r
  return EFI_SUCCESS;\r
}\r
\r
\r
EFI_STATUS\r
EFIAPI\r
ArmDmaLibConstructor (\r
  IN EFI_HANDLE       ImageHandle,\r
  IN EFI_SYSTEM_TABLE *SystemTable\r
  )\r
{\r
  EFI_STATUS              Status;\r
\r
  // Get the Cpu protocol for later use\r
  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&gCpu);\r
  ASSERT_EFI_ERROR(Status);\r
\r
  gCacheAlignment = ArmDataCacheLineLength ();\r
  \r
  return Status;\r
}\r
\r
Commit	Line	Data
938f46b4	1	/** @file\r
	2	Generic ARM implementation of DmaLib.h\r
	3	\r
	4	Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>\r
	5	\r
	6	This program and the accompanying materials\r
	7	are licensed and made available under the terms and conditions of the BSD License\r
	8	which accompanies this distribution. The full text of the license may be found at\r
	9	http://opensource.org/licenses/bsd-license.php\r
	10	\r
	11	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	12	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	13	\r
	14	**/\r
	15	\r
e6d572ba	16	#include <PiDxe.h>\r
938f46b4	17	#include <Library/DebugLib.h>\r
938f46b4	18	#include <Library/DmaLib.h>\r
e6d572ba	19	#include <Library/DxeServicesTableLib.h>\r
938f46b4	20	#include <Library/MemoryAllocationLib.h>\r
	21	#include <Library/UefiBootServicesTableLib.h>\r
	22	#include <Library/UncachedMemoryAllocationLib.h>\r
	23	#include <Library/IoLib.h>\r
	24	#include <Library/BaseMemoryLib.h>\r
	25	#include <Library/ArmLib.h>\r
	26	\r
	27	#include <Protocol/Cpu.h>\r
	28	\r
	29	typedef struct {\r
	30	EFI_PHYSICAL_ADDRESS HostAddress;\r
	31	EFI_PHYSICAL_ADDRESS DeviceAddress;\r
	32	UINTN NumberOfBytes;\r
	33	DMA_MAP_OPERATION Operation;\r
	34	BOOLEAN DoubleBuffer;\r
	35	} MAP_INFO_INSTANCE;\r
	36	\r
	37	\r
	38	\r
	39	EFI_CPU_ARCH_PROTOCOL *gCpu;\r
	40	UINTN gCacheAlignment = 0;\r
	41	\r
938f46b4	42	/** \r
	43	Provides the DMA controller-specific addresses needed to access system memory.\r
	44	\r
	45	Operation is relative to the DMA bus master.\r
	46	\r
	47	@param Operation Indicates if the bus master is going to read or write to system memory.\r
	48	@param HostAddress The system memory address to map to the DMA controller.\r
	49	@param NumberOfBytes On input the number of bytes to map. On output the number of bytes\r
	50	that were mapped. \r
	51	@param DeviceAddress The resulting map address for the bus master controller to use to\r
	52	access the hosts HostAddress. \r
	53	@param Mapping A resulting value to pass to Unmap().\r
	54	\r
	55	@retval EFI_SUCCESS The range was mapped for the returned NumberOfBytes.\r
	56	@retval EFI_UNSUPPORTED The HostAddress cannot be mapped as a common buffer. \r
	57	@retval EFI_INVALID_PARAMETER One or more parameters are invalid.\r
	58	@retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.\r
	59	@retval EFI_DEVICE_ERROR The system hardware could not map the requested address.\r
	60	\r
	61	**/\r
	62	EFI_STATUS\r
	63	EFIAPI\r
	64	DmaMap (\r
	65	IN DMA_MAP_OPERATION Operation,\r
	66	IN VOID *HostAddress,\r
	67	IN OUT UINTN *NumberOfBytes,\r
	68	OUT PHYSICAL_ADDRESS *DeviceAddress,\r
	69	OUT VOID **Mapping\r
	70	)\r
	71	{\r
e6d572ba	72	EFI_STATUS Status;\r
	73	MAP_INFO_INSTANCE *Map;\r
	74	VOID *Buffer;\r
	75	EFI_GCD_MEMORY_SPACE_DESCRIPTOR GcdDescriptor;\r
938f46b4	76	\r
e6d572ba	77	if (HostAddress == NULL \|\| NumberOfBytes == NULL \|\| DeviceAddress == NULL \|\| Mapping == NULL ) {\r
938f46b4	78	return EFI_INVALID_PARAMETER;\r
938f46b4	79	}\r
938f46b4	80	\r
	81	if (Operation >= MapOperationMaximum) {\r
	82	return EFI_INVALID_PARAMETER;\r
	83	}\r
	84	\r
	85	*DeviceAddress = ConvertToPhysicalAddress (HostAddress);\r
	86	\r
	87	// Remember range so we can flush on the other side\r
	88	Map = AllocatePool (sizeof (MAP_INFO_INSTANCE));\r
	89	if (Map == NULL) {\r
	90	return EFI_OUT_OF_RESOURCES;\r
	91	}\r
	92	\r
	93	*Mapping = Map;\r
	94	\r
3ea3ff88	95	if ((((UINTN)HostAddress & (gCacheAlignment - 1)) != 0) \|\|\r
3ea3ff88	96	((*NumberOfBytes % gCacheAlignment) != 0)) {\r
e6d572ba	97	\r
e6d572ba	98	// Get the cacheability of the region\r
151acec6	99	Status = gDS->GetMemorySpaceDescriptor (*DeviceAddress, &GcdDescriptor);\r
e6d572ba	100	if (EFI_ERROR(Status)) {\r
938f46b4	101	return Status;\r
938f46b4	102	}\r
e6d572ba	103	\r
e6d572ba	104	// If the mapped buffer is not an uncached buffer\r
3f5aa193	105	if ( (GcdDescriptor.Attributes != EFI_MEMORY_WC) &&\r
	106	(GcdDescriptor.Attributes != EFI_MEMORY_UC) )\r
	107	{\r
e6d572ba	108	//\r
	109	// If the buffer does not fill entire cache lines we must double buffer into\r
	110	// uncached memory. Device (PCI) address becomes uncached page.\r
	111	//\r
	112	Map->DoubleBuffer = TRUE;\r
	113	Status = DmaAllocateBuffer (EfiBootServicesData, EFI_SIZE_TO_PAGES (*NumberOfBytes), &Buffer);\r
	114	if (EFI_ERROR (Status)) {\r
	115	return Status;\r
	116	}\r
	117	\r
	118	if ((Operation == MapOperationBusMasterRead) \|\| (Operation == MapOperationBusMasterCommonBuffer)) {\r
	119	CopyMem (Buffer, HostAddress, *NumberOfBytes);\r
	120	}\r
	121	\r
	122	*DeviceAddress = (PHYSICAL_ADDRESS)(UINTN)Buffer;\r
	123	} else {\r
	124	Map->DoubleBuffer = FALSE;\r
	125	}\r
938f46b4	126	} else {\r
938f46b4	127	Map->DoubleBuffer = FALSE;\r
e6d572ba	128	\r
	129	// Flush the Data Cache (should not have any effect if the memory region is uncached)\r
	130	gCpu->FlushDataCache (gCpu, DeviceAddress, NumberOfBytes, EfiCpuFlushTypeWriteBackInvalidate);\r
	131	\r
	132	if ((Operation == MapOperationBusMasterRead) \|\| (Operation == MapOperationBusMasterCommonBuffer)) {\r
	133	// In case the buffer is used for instance to send command to a PCI controller, we must ensure the memory is uncached\r
db06c2d7	134	Status = gDS->SetMemorySpaceAttributes (DeviceAddress & ~(BASE_4KB - 1), ALIGN_VALUE (NumberOfBytes, BASE_4KB), EFI_MEMORY_WC);\r
e6d572ba	135	ASSERT_EFI_ERROR (Status);\r
e6d572ba	136	}\r
938f46b4	137	}\r
938f46b4	138	\r
938f46b4	139	Map->HostAddress = (UINTN)HostAddress;\r
	140	Map->DeviceAddress = *DeviceAddress;\r
	141	Map->NumberOfBytes = *NumberOfBytes;\r
	142	Map->Operation = Operation;\r
	143	\r
938f46b4	144	return EFI_SUCCESS;\r
	145	}\r
	146	\r
	147	\r
	148	/** \r
	149	Completes the DmaMapBusMasterRead(), DmaMapBusMasterWrite(), or DmaMapBusMasterCommonBuffer()\r
	150	operation and releases any corresponding resources.\r
	151	\r
	152	@param Mapping The mapping value returned from DmaMap*().\r
	153	\r
	154	@retval EFI_SUCCESS The range was unmapped.\r
	155	@retval EFI_DEVICE_ERROR The data was not committed to the target system memory.\r
	156	\r
	157	**/\r
	158	EFI_STATUS\r
	159	EFIAPI\r
	160	DmaUnmap (\r
	161	IN VOID *Mapping\r
	162	)\r
	163	{\r
	164	MAP_INFO_INSTANCE *Map;\r
	165	\r
	166	if (Mapping == NULL) {\r
	167	ASSERT (FALSE);\r
	168	return EFI_INVALID_PARAMETER;\r
	169	}\r
	170	\r
	171	Map = (MAP_INFO_INSTANCE *)Mapping;\r
	172	\r
	173	if (Map->DoubleBuffer) {\r
e6d572ba	174	if ((Map->Operation == MapOperationBusMasterWrite) \|\| (Map->Operation == MapOperationBusMasterCommonBuffer)) {\r
938f46b4	175	CopyMem ((VOID )(UINTN)Map->HostAddress, (VOID )(UINTN)Map->DeviceAddress, Map->NumberOfBytes);\r
	176	}\r
	177	\r
	178	DmaFreeBuffer (EFI_SIZE_TO_PAGES (Map->NumberOfBytes), (VOID *)(UINTN)Map->DeviceAddress);\r
	179	\r
	180	} else {\r
	181	if (Map->Operation == MapOperationBusMasterWrite) {\r
	182	//\r
	183	// Make sure we read buffer from uncached memory and not the cache\r
	184	//\r
	185	gCpu->FlushDataCache (gCpu, Map->HostAddress, Map->NumberOfBytes, EfiCpuFlushTypeInvalidate);\r
	186	}\r
	187	}\r
	188	\r
	189	FreePool (Map);\r
	190	\r
	191	return EFI_SUCCESS;\r
	192	}\r
	193	\r
	194	/** \r
	195	Allocates pages that are suitable for an DmaMap() of type MapOperationBusMasterCommonBuffer.\r
	196	mapping. \r
	197	\r
	198	@param MemoryType The type of memory to allocate, EfiBootServicesData or\r
	199	EfiRuntimeServicesData. \r
	200	@param Pages The number of pages to allocate. \r
	201	@param HostAddress A pointer to store the base system memory address of the\r
	202	allocated range. \r
	203	\r
	204	@retval EFI_SUCCESS The requested memory pages were allocated.\r
	205	@retval EFI_UNSUPPORTED Attributes is unsupported. The only legal attribute bits are\r
	206	MEMORY_WRITE_COMBINE and MEMORY_CACHED. \r
	207	@retval EFI_INVALID_PARAMETER One or more parameters are invalid.\r
	208	@retval EFI_OUT_OF_RESOURCES The memory pages could not be allocated. \r
	209	\r
	210	**/\r
	211	EFI_STATUS\r
	212	EFIAPI\r
	213	DmaAllocateBuffer (\r
	214	IN EFI_MEMORY_TYPE MemoryType,\r
	215	IN UINTN Pages,\r
	216	OUT VOID **HostAddress\r
	217	)\r
	218	{\r
	219	if (HostAddress == NULL) {\r
	220	return EFI_INVALID_PARAMETER;\r
	221	}\r
	222	\r
	223	//\r
	224	// The only valid memory types are EfiBootServicesData and EfiRuntimeServicesData\r
	225	//\r
	226	// We used uncached memory to keep coherency\r
	227	//\r
	228	if (MemoryType == EfiBootServicesData) {\r
	229	*HostAddress = UncachedAllocatePages (Pages);\r
1bfda055	230	} else if (MemoryType == EfiRuntimeServicesData) {\r
938f46b4	231	*HostAddress = UncachedAllocateRuntimePages (Pages);\r
	232	} else {\r
	233	return EFI_INVALID_PARAMETER;\r
	234	}\r
	235	\r
	236	return EFI_SUCCESS;\r
	237	}\r
	238	\r
	239	\r
	240	/** \r
	241	Frees memory that was allocated with DmaAllocateBuffer().\r
	242	\r
	243	@param Pages The number of pages to free. \r
	244	@param HostAddress The base system memory address of the allocated range. \r
	245	\r
	246	@retval EFI_SUCCESS The requested memory pages were freed.\r
	247	@retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and Pages\r
	248	was not allocated with DmaAllocateBuffer().\r
	249	\r
	250	**/\r
	251	EFI_STATUS\r
	252	EFIAPI\r
	253	DmaFreeBuffer (\r
	254	IN UINTN Pages,\r
	255	IN VOID *HostAddress\r
	256	)\r
	257	{\r
	258	if (HostAddress == NULL) {\r
	259	return EFI_INVALID_PARAMETER;\r
	260	} \r
	261	\r
	262	UncachedFreePages (HostAddress, Pages);\r
	263	return EFI_SUCCESS;\r
	264	}\r
	265	\r
	266	\r
	267	EFI_STATUS\r
	268	EFIAPI\r
	269	ArmDmaLibConstructor (\r
	270	IN EFI_HANDLE ImageHandle,\r
	271	IN EFI_SYSTEM_TABLE *SystemTable\r
	272	)\r
	273	{\r
	274	EFI_STATUS Status;\r
	275	\r
	276	// Get the Cpu protocol for later use\r
	277	Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&gCpu);\r
	278	ASSERT_EFI_ERROR(Status);\r
	279	\r
	280	gCacheAlignment = ArmDataCacheLineLength ();\r
	281	\r
	282	return Status;\r
	283	}\r
	284	\r