From bfe34275a9bf56a7f8ea9d19fe10cbbee599148d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 12 Nov 2016 14:02:28 +0100 Subject: [PATCH] ArmPkg/ArmDmaLib: add support for fixed host-to-device DMA offset Some devices, such as the Raspberry Pi3, have a fixed offset between memory addresses as seen by the host and as seen by the other bus masters. So add a new PCD that allows this fixed offset to be recorded, and to be used when returning device addresses from the DmaLib mapping routines. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel Tested-by: Ryan Harkin Reviewed-by: Leif Lindholm --- ArmPkg/ArmPkg.dec | 8 ++++++++ ArmPkg/Library/ArmDmaLib/ArmDmaLib.c | 20 ++++++++++++++++++-- ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf | 1 + 3 files changed, 27 insertions(+), 2 deletions(-) diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec index 3cdb5da3d4..090ed99513 100644 --- a/ArmPkg/ArmPkg.dec +++ b/ArmPkg/ArmPkg.dec @@ -134,6 +134,14 @@ gArmTokenSpaceGuid.PcdFdSize|0|UINT32|0x0000002C gArmTokenSpaceGuid.PcdFvSize|0|UINT32|0x0000002E + # + # Value to add to a host address to obtain a device address, using + # unsigned 64-bit integer arithmetic on both ARM and AArch64. This + # means we can rely on truncation on overflow to specify negative + # offsets. + # + gArmTokenSpaceGuid.PcdArmDmaDeviceOffset|0x0|UINT64|0x0000044 + [PcdsFixedAtBuild.common, PcdsPatchableInModule.common] gArmTokenSpaceGuid.PcdFdBaseAddress|0|UINT64|0x0000002B gArmTokenSpaceGuid.PcdFvBaseAddress|0|UINT64|0x0000002D diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c index f39d30c44e..acc106bcf4 100644 --- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c +++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c @@ -37,6 +37,15 @@ typedef struct { STATIC EFI_CPU_ARCH_PROTOCOL *mCpu; +STATIC +PHYSICAL_ADDRESS +HostToDeviceAddress ( + IN PHYSICAL_ADDRESS HostAddress + ) +{ + return HostAddress + PcdGet64 (PcdArmDmaDeviceOffset); +} + /** Provides the DMA controller-specific addresses needed to access system memory. @@ -80,7 +89,14 @@ DmaMap ( return EFI_INVALID_PARAMETER; } - *DeviceAddress = ConvertToPhysicalAddress (HostAddress); + // + // The debug implementation of UncachedMemoryAllocationLib in ArmPkg returns + // a virtual uncached alias, and unmaps the cached ID mapping of the buffer, + // in order to catch inadvertent references to the cached mapping. + // Since HostToDeviceAddress () expects ID mapped input addresses, convert + // the host address to an ID mapped address first. + // + *DeviceAddress = HostToDeviceAddress (ConvertToPhysicalAddress (HostAddress)); // Remember range so we can flush on the other side Map = AllocatePool (sizeof (MAP_INFO_INSTANCE)); @@ -126,7 +142,7 @@ DmaMap ( CopyMem (Buffer, HostAddress, *NumberOfBytes); } - *DeviceAddress = ConvertToPhysicalAddress ((UINTN)Buffer); + *DeviceAddress = HostToDeviceAddress (ConvertToPhysicalAddress ((UINTN)Buffer)); Map->BufferAddress = Buffer; } else { Map->DoubleBuffer = FALSE; diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf index 31de3cfd82..9b7dad114b 100644 --- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf +++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf @@ -44,6 +44,7 @@ [Guids] [Pcd] + gArmTokenSpaceGuid.PcdArmDmaDeviceOffset [Depex] gEfiCpuArchProtocolGuid -- 2.39.2