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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2015-11-09 13:28:17 +0000
committerabiesheuvel <abiesheuvel@Edk2>2015-11-09 13:28:17 +0000
commitc653fc2a91a946ea249e5d6161bca84f6c824f09 (patch)
treed7f4d81b5b674fdc1bdf02ec67a38ab8a08d5462 /ArmPkg
parent8c5ac451d570f0a5680dd7614eb19404feb717d9 (diff)
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ArmPkg/ArmLib: add accessor function for Cache Writeback Granule
Add a function to ArmLib that provides access to the Cache Writeback Granule (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 <ard.biesheuvel@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18758 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'ArmPkg')
-rw-r--r--ArmPkg/Include/Library/ArmLib.h6
-rw-r--r--ArmPkg/Library/ArmLib/Common/ArmLib.c17
2 files changed, 23 insertions, 0 deletions
diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h
index 2059a67bbf..a328146b69 100644
--- a/ArmPkg/Include/Library/ArmLib.h
+++ b/ArmPkg/Include/Library/ArmLib.h
@@ -116,6 +116,12 @@ ArmInstructionCacheLineLength (
UINTN
EFIAPI
+ArmCacheWritebackGranule (
+ VOID
+ );
+
+UINTN
+EFIAPI
ArmIsArchTimerImplemented (
VOID
);
diff --git a/ArmPkg/Library/ArmLib/Common/ArmLib.c b/ArmPkg/Library/ArmLib/Common/ArmLib.c
index ad0a265e9f..7e227936fa 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
+ArmCacheWritebackGranule (
+ VOID
+ )
+{
+ UINTN CWG;
+
+ CWG = (ArmCacheInfo () >> 24) & 0xf; // CTR_EL0.CWG
+
+ if (CWG == 0) {
+ return SIZE_2KB;
+ }
+
+ return 4 << CWG;
+}