From e58a71d9c50ba641b5ab19f5ce2cbf772187de4d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 5 Sep 2016 09:55:16 +0100 Subject: MdeModulePkg/PciHostBridgeDxe: restrict 64-bit DMA to devices that support it 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|CommonBuffer}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 Reviewed-by: Ruiyu Ni --- MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'MdeModulePkg/Bus/Pci') diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c index b2d76d67af..8af131b0af 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 // -- cgit v1.2.3