Currently, the EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE attribute is completely
ignored by the PCI host bridge driver, which means that, on an implementation
that supports DMA above 4 GB, allocations above 4 GB may be provided to
devices that have not expressed support for it.
So in addition to checking 'RootBridge->DmaAbove4G' to establish whether the
root bridge itself supports DMA above 4 GB, we must also take into account
the operation type (EfiPciOperationBusMaster{Read|Write|CommBuffer}64),
and the EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE attribute, when mapping and
allocating DMA memory, respectively.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <[email protected]>
---
MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
index b2d76d67afa2..8af131b0af37 100644
--- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
+++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
@@ -1073,10 +1073,15 @@ RootBridgeIoMap (
RootBridge = ROOT_BRIDGE_FROM_THIS (This);
PhysicalAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress;
- if (!RootBridge->DmaAbove4G && ((PhysicalAddress + *NumberOfBytes) >
SIZE_4GB)) {
+ if ((!RootBridge->DmaAbove4G ||
+ (Operation != EfiPciOperationBusMasterRead64 &&
+ Operation != EfiPciOperationBusMasterWrite64 &&
+ Operation != EfiPciOperationBusMasterCommonBuffer64)) &&
+ ((PhysicalAddress + *NumberOfBytes) > SIZE_4GB)) {
+
//
- // If the root bridge can not handle performing DMA above 4GB but
- // any part of the DMA transfer being mapped is above 4GB, then
+ // If the root bridge or the device cannot handle performing DMA above
+ // 4GB but any part of the DMA transfer being mapped is above 4GB, then
// map the DMA transfer to a buffer below 4GB.
//
@@ -1308,7 +1313,8 @@ RootBridgeIoAllocateBuffer (
RootBridge = ROOT_BRIDGE_FROM_THIS (This);
AllocateType = AllocateAnyPages;
- if (!RootBridge->DmaAbove4G) {
+ if (!RootBridge->DmaAbove4G ||
+ (Attributes & EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE) == 0) {
//
// Limit allocations to memory below 4GB
//
--
2.7.4
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