diff options
| -rw-r--r-- | ArmPkg/Library/ArmDmaLib/ArmDmaLib.c | 55 |
1 files changed, 36 insertions, 19 deletions
diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c index f4ee9e4c5e..566f77d03f 100644 --- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c +++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c @@ -2,6 +2,7 @@ Generic ARM implementation of DmaLib.h
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
+ Copyright (c) 2015 - 2017, Linaro, Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
@@ -80,6 +81,7 @@ DmaMap ( MAP_INFO_INSTANCE *Map;
VOID *Buffer;
EFI_GCD_MEMORY_SPACE_DESCRIPTOR GcdDescriptor;
+ UINTN AllocSize;
if (HostAddress == NULL || NumberOfBytes == NULL || DeviceAddress == NULL || Mapping == NULL ) {
return EFI_INVALID_PARAMETER;
@@ -104,8 +106,9 @@ DmaMap ( return EFI_OUT_OF_RESOURCES;
}
- if ((((UINTN)HostAddress & (mCpu->DmaBufferAlignment - 1)) != 0) ||
- ((*NumberOfBytes & (mCpu->DmaBufferAlignment - 1)) != 0)) {
+ if (Operation != MapOperationBusMasterRead &&
+ ((((UINTN)HostAddress & (mCpu->DmaBufferAlignment - 1)) != 0) ||
+ ((*NumberOfBytes & (mCpu->DmaBufferAlignment - 1)) != 0))) {
// Get the cacheability of the region
Status = gDS->GetMemorySpaceDescriptor ((UINTN)HostAddress, &GcdDescriptor);
@@ -129,21 +132,31 @@ DmaMap ( }
//
- // If the buffer does not fill entire cache lines we must double buffer into
- // uncached memory. Device (PCI) address becomes uncached page.
+ // If the buffer does not fill entire cache lines we must double buffer
+ // into a suitably aligned allocation that allows us to invalidate the
+ // cache without running the risk of corrupting adjacent unrelated data.
+ // Note that pool allocations are guaranteed to be 8 byte aligned, so
+ // we only have to add (alignment - 8) worth of padding.
//
- Map->DoubleBuffer = TRUE;
- Status = DmaAllocateBuffer (EfiBootServicesData, EFI_SIZE_TO_PAGES (*NumberOfBytes), &Buffer);
- if (EFI_ERROR (Status)) {
+ Map->DoubleBuffer = TRUE;
+ AllocSize = ALIGN_VALUE (*NumberOfBytes, mCpu->DmaBufferAlignment) +
+ (mCpu->DmaBufferAlignment - 8);
+ Map->BufferAddress = AllocatePool (AllocSize);
+ if (Map->BufferAddress == NULL) {
+ Status = EFI_OUT_OF_RESOURCES;
goto FreeMapInfo;
}
- if (Operation == MapOperationBusMasterRead) {
- CopyMem (Buffer, HostAddress, *NumberOfBytes);
- }
-
+ Buffer = ALIGN_POINTER (Map->BufferAddress, mCpu->DmaBufferAlignment);
*DeviceAddress = HostToDeviceAddress (ConvertToPhysicalAddress (Buffer));
- Map->BufferAddress = Buffer;
+
+ //
+ // Get rid of any dirty cachelines covering the double buffer. This
+ // prevents them from being written back unexpectedly, potentially
+ // overwriting the data we receive from the device.
+ //
+ mCpu->FlushDataCache (mCpu, (UINTN)Buffer, *NumberOfBytes,
+ EfiCpuFlushTypeWriteBack);
} else {
Map->DoubleBuffer = FALSE;
}
@@ -207,6 +220,7 @@ DmaUnmap ( {
MAP_INFO_INSTANCE *Map;
EFI_STATUS Status;
+ VOID *Buffer;
if (Mapping == NULL) {
ASSERT (FALSE);
@@ -217,17 +231,20 @@ DmaUnmap ( Status = EFI_SUCCESS;
if (Map->DoubleBuffer) {
- ASSERT (Map->Operation != MapOperationBusMasterCommonBuffer);
+ ASSERT (Map->Operation == MapOperationBusMasterWrite);
- if (Map->Operation == MapOperationBusMasterCommonBuffer) {
+ if (Map->Operation != MapOperationBusMasterWrite) {
Status = EFI_INVALID_PARAMETER;
- } else if (Map->Operation == MapOperationBusMasterWrite) {
- CopyMem ((VOID *)(UINTN)Map->HostAddress, Map->BufferAddress,
- Map->NumberOfBytes);
- }
+ } else {
+ Buffer = ALIGN_POINTER (Map->BufferAddress, mCpu->DmaBufferAlignment);
- DmaFreeBuffer (EFI_SIZE_TO_PAGES (Map->NumberOfBytes), Map->BufferAddress);
+ mCpu->FlushDataCache (mCpu, (UINTN)Buffer, Map->NumberOfBytes,
+ EfiCpuFlushTypeInvalidate);
+ CopyMem ((VOID *)(UINTN)Map->HostAddress, Buffer, Map->NumberOfBytes);
+
+ FreePool (Map->BufferAddress);
+ }
} else {
if (Map->Operation == MapOperationBusMasterWrite) {
//
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