[PATCH 2/3] ArmPkg/UncachedMemoryAllocationLib: use CWG value to align pool allocations

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Uncached pool allocations are aligned to the data cache line length under
the assumption that this is sufficient to prevent cache maintenance from
corrupting adjacent allocations. However, the value to use in such cases
is architecturally called the Cache Writeback Granule (CWG), which is
essentially the maximum Dcache line length rather than the minimum.

Note that this is mostly a cosmetical fix, given that the pool allocation
is turned into a page allocation later, and rounded up accordingly.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c b/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c
index cd13a7da92e0..0d8abad23433 100644
--- a/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c
+++ b/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c
@@ -545,7 +545,7 @@ UncachedInternalAllocatePool (
   IN UINTN            AllocationSize
   )
 {
-  UINTN CacheLineLength = ArmDataCacheLineLength ();
+  UINTN CacheLineLength = ArmCacheWritebackGranule ();
   return UncachedInternalAllocateAlignedPool (MemoryType, AllocationSize, CacheLineLength);
 }
 
-- 
2.7.4