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EmbeddedPkg/NonCoherentDmaLib: implement support for DMA range limits
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Implement support for driving peripherals with limited DMA ranges to
NonCoherentDmaLib, by adding a device address limit, and taking it,
along with the device offset, into account when allocating or mapping
DMA buffers.

Signed-off-by: Ard Biesheuvel <[email protected]>
Tested-by: Pete Batard <[email protected]>
Acked-by: Philippe Mathieu-Daude <[email protected]>
Acked-by: Leif Lindholm <[email protected]>
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@mergify
Ard Biesheuvel authored and mergify[bot] committed Dec 6, 2019
1 parent 9caaa79 commit 62a7565
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Showing 3 changed files with 160 additions and 12 deletions.
6 changes: 6 additions & 0 deletions EmbeddedPkg/EmbeddedPkg.dec
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Original file line number Diff line number Diff line change
Expand Up @@ -186,6 +186,12 @@
#
gEmbeddedTokenSpaceGuid.PcdDmaDeviceOffset|0x0|UINT64|0x0000058

#
# Highest address value supported by the device for DMA addressing. Note
# that this value should be strictly greater than PcdDmaDeviceOffset.
#
gEmbeddedTokenSpaceGuid.PcdDmaDeviceLimit|0xFFFFFFFFFFFFFFFF|UINT64|0x000005A

#
# Selection between DT and ACPI as a default
#
Expand Down
165 changes: 153 additions & 12 deletions EmbeddedPkg/Library/NonCoherentDmaLib/NonCoherentDmaLib.c
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Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,8 @@ typedef struct {
STATIC EFI_CPU_ARCH_PROTOCOL *mCpu;
STATIC LIST_ENTRY UncachedAllocationList;

STATIC PHYSICAL_ADDRESS mDmaHostAddressLimit;

STATIC
PHYSICAL_ADDRESS
HostToDeviceAddress (
Expand All @@ -49,6 +51,102 @@ HostToDeviceAddress (
return (PHYSICAL_ADDRESS)(UINTN)Address + PcdGet64 (PcdDmaDeviceOffset);
}

/**
Allocates one or more 4KB pages of a certain memory type at a specified
alignment.
Allocates the number of 4KB pages specified by Pages of a certain memory type
with an alignment specified by Alignment. The allocated buffer is returned.
If Pages is 0, then NULL is returned. If there is not enough memory at the
specified alignment remaining to satisfy the request, then NULL is returned.
If Alignment is not a power of two and Alignment is not zero, then ASSERT().
If Pages plus EFI_SIZE_TO_PAGES (Alignment) overflows, then ASSERT().
@param MemoryType The type of memory to allocate.
@param Pages The number of 4 KB pages to allocate.
@param Alignment The requested alignment of the allocation.
Must be a power of two.
If Alignment is zero, then byte alignment is
used.
@return A pointer to the allocated buffer or NULL if allocation fails.
**/
STATIC
VOID *
InternalAllocateAlignedPages (
IN EFI_MEMORY_TYPE MemoryType,
IN UINTN Pages,
IN UINTN Alignment
)
{
EFI_STATUS Status;
EFI_PHYSICAL_ADDRESS Memory;
UINTN AlignedMemory;
UINTN AlignmentMask;
UINTN UnalignedPages;
UINTN RealPages;

//
// Alignment must be a power of two or zero.
//
ASSERT ((Alignment & (Alignment - 1)) == 0);

if (Pages == 0) {
return NULL;
}
if (Alignment > EFI_PAGE_SIZE) {
//
// Calculate the total number of pages since alignment is larger than page
// size.
//
AlignmentMask = Alignment - 1;
RealPages = Pages + EFI_SIZE_TO_PAGES (Alignment);
//
// Make sure that Pages plus EFI_SIZE_TO_PAGES (Alignment) does not
// overflow.
//
ASSERT (RealPages > Pages);

Memory = mDmaHostAddressLimit;
Status = gBS->AllocatePages (AllocateMaxAddress, MemoryType, RealPages,
&Memory);
if (EFI_ERROR (Status)) {
return NULL;
}
AlignedMemory = ((UINTN)Memory + AlignmentMask) & ~AlignmentMask;
UnalignedPages = EFI_SIZE_TO_PAGES (AlignedMemory - (UINTN)Memory);
if (UnalignedPages > 0) {
//
// Free first unaligned page(s).
//
Status = gBS->FreePages (Memory, UnalignedPages);
ASSERT_EFI_ERROR (Status);
}
Memory = AlignedMemory + EFI_PAGES_TO_SIZE (Pages);
UnalignedPages = RealPages - Pages - UnalignedPages;
if (UnalignedPages > 0) {
//
// Free last unaligned page(s).
//
Status = gBS->FreePages (Memory, UnalignedPages);
ASSERT_EFI_ERROR (Status);
}
} else {
//
// Do not over-allocate pages in this case.
//
Memory = mDmaHostAddressLimit;
Status = gBS->AllocatePages (AllocateMaxAddress, MemoryType, Pages,
&Memory);
if (EFI_ERROR (Status)) {
return NULL;
}
AlignedMemory = (UINTN)Memory;
}
return (VOID *)AlignedMemory;
}

/**
Provides the DMA controller-specific addresses needed to access system memory.
Expand Down Expand Up @@ -111,7 +209,30 @@ DmaMap (
return EFI_OUT_OF_RESOURCES;
}

if (Operation != MapOperationBusMasterRead &&
if (((UINTN)HostAddress + *NumberOfBytes) > mDmaHostAddressLimit) {

if (Operation == MapOperationBusMasterCommonBuffer) {
goto CommonBufferError;
}

AllocSize = ALIGN_VALUE (*NumberOfBytes, mCpu->DmaBufferAlignment);
Map->BufferAddress = InternalAllocateAlignedPages (EfiBootServicesData,
EFI_SIZE_TO_PAGES (AllocSize),
mCpu->DmaBufferAlignment);
if (Map->BufferAddress == NULL) {
Status = EFI_OUT_OF_RESOURCES;
goto FreeMapInfo;
}

if (Map->Operation == MapOperationBusMasterRead) {
CopyMem (Map->BufferAddress, (VOID *)(UINTN)Map->HostAddress,
*NumberOfBytes);
}
mCpu->FlushDataCache (mCpu, (UINTN)Map->BufferAddress, AllocSize,
EfiCpuFlushTypeWriteBack);

*DeviceAddress = HostToDeviceAddress (Map->BufferAddress);
} else if (Operation != MapOperationBusMasterRead &&
((((UINTN)HostAddress & (mCpu->DmaBufferAlignment - 1)) != 0) ||
((*NumberOfBytes & (mCpu->DmaBufferAlignment - 1)) != 0))) {

Expand All @@ -128,12 +249,7 @@ DmaMap (
// on uncached buffers.
//
if (Operation == MapOperationBusMasterCommonBuffer) {
DEBUG ((DEBUG_ERROR,
"%a: Operation type 'MapOperationBusMasterCommonBuffer' is only "
"supported\non memory regions that were allocated using "
"DmaAllocateBuffer ()\n", __FUNCTION__));
Status = EFI_UNSUPPORTED;
goto FreeMapInfo;
goto CommonBufferError;
}

//
Expand Down Expand Up @@ -199,6 +315,12 @@ DmaMap (

return EFI_SUCCESS;

CommonBufferError:
DEBUG ((DEBUG_ERROR,
"%a: Operation type 'MapOperationBusMasterCommonBuffer' is only "
"supported\non memory regions that were allocated using "
"DmaAllocateBuffer ()\n", __FUNCTION__));
Status = EFI_UNSUPPORTED;
FreeMapInfo:
FreePool (Map);

Expand Down Expand Up @@ -229,6 +351,7 @@ DmaUnmap (
MAP_INFO_INSTANCE *Map;
EFI_STATUS Status;
VOID *Buffer;
UINTN AllocSize;

if (Mapping == NULL) {
ASSERT (FALSE);
Expand All @@ -238,7 +361,17 @@ DmaUnmap (
Map = (MAP_INFO_INSTANCE *)Mapping;

Status = EFI_SUCCESS;
if (Map->DoubleBuffer) {
if (((UINTN)Map->HostAddress + Map->NumberOfBytes) > mDmaHostAddressLimit) {
AllocSize = ALIGN_VALUE (Map->NumberOfBytes, mCpu->DmaBufferAlignment);
if (Map->Operation == MapOperationBusMasterWrite) {
mCpu->FlushDataCache (mCpu, (UINTN)Map->BufferAddress, AllocSize,
EfiCpuFlushTypeInvalidate);
CopyMem ((VOID *)(UINTN)Map->HostAddress, Map->BufferAddress,
Map->NumberOfBytes);
}
FreePages (Map->BufferAddress, EFI_SIZE_TO_PAGES (AllocSize));
} else if (Map->DoubleBuffer) {

ASSERT (Map->Operation == MapOperationBusMasterWrite);

if (Map->Operation != MapOperationBusMasterWrite) {
Expand Down Expand Up @@ -335,10 +468,9 @@ DmaAllocateAlignedBuffer (
return EFI_INVALID_PARAMETER;
}

if (MemoryType == EfiBootServicesData) {
Allocation = AllocateAlignedPages (Pages, Alignment);
} else if (MemoryType == EfiRuntimeServicesData) {
Allocation = AllocateAlignedRuntimePages (Pages, Alignment);
if (MemoryType == EfiBootServicesData ||
MemoryType == EfiRuntimeServicesData) {
Allocation = InternalAllocateAlignedPages (MemoryType, Pages, Alignment);
} else {
return EFI_INVALID_PARAMETER;
}
Expand Down Expand Up @@ -479,6 +611,15 @@ NonCoherentDmaLibConstructor (
{
InitializeListHead (&UncachedAllocationList);

//
// Ensure that the combination of DMA addressing offset and limit produces
// a sane value.
//
ASSERT (PcdGet64 (PcdDmaDeviceLimit) > PcdGet64 (PcdDmaDeviceOffset));

mDmaHostAddressLimit = PcdGet64 (PcdDmaDeviceLimit) -
PcdGet64 (PcdDmaDeviceOffset);

// Get the Cpu protocol for later use
return gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&mCpu);
}
1 change: 1 addition & 0 deletions EmbeddedPkg/Library/NonCoherentDmaLib/NonCoherentDmaLib.inf
View file
Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,7 @@

[Pcd]
gEmbeddedTokenSpaceGuid.PcdDmaDeviceOffset
gEmbeddedTokenSpaceGuid.PcdDmaDeviceLimit

[Depex]
gEfiCpuArchProtocolGuid

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