Add a function to ArmLib that provides access to the Cache Writeback Granularity (CWG) field in CTR_EL0. This information is required when performing non-coherent DMA.
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <[email protected]> --- ArmPkg/Include/Library/ArmLib.h | 6 ++++++ ArmPkg/Library/ArmLib/Common/ArmLib.c | 17 +++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h index 2059a67bbf3c..6a52006b504e 100644 --- a/ArmPkg/Include/Library/ArmLib.h +++ b/ArmPkg/Include/Library/ArmLib.h @@ -116,6 +116,12 @@ ArmInstructionCacheLineLength ( UINTN EFIAPI +ArmCacheWritebackGranularity ( + VOID + ); + +UINTN +EFIAPI ArmIsArchTimerImplemented ( VOID ); diff --git a/ArmPkg/Library/ArmLib/Common/ArmLib.c b/ArmPkg/Library/ArmLib/Common/ArmLib.c index ad0a265e9f59..0de323a30ff1 100644 --- a/ArmPkg/Library/ArmLib/Common/ArmLib.c +++ b/ArmPkg/Library/ArmLib/Common/ArmLib.c @@ -88,3 +88,20 @@ ArmInstructionCacheLineLength ( { return 4 << (ArmCacheInfo () & 0xf); // CTR_EL0.IminLine } + +UINTN +EFIAPI +ArmCacheWritebackGranularity ( + VOID + ) +{ + UINTN CWG; + + CWG = (ArmCacheInfo () >> 24) & 0xf; // CTR_EL0.CWG + + if (CWG == 0) { + return SIZE_512KB; + } + + return 4 << CWG; +} -- 1.9.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
