[PATCH 2/2] ArmPlatformPkg/PL111LcdArmVExpressLib: use write-combine mapping for VRAM

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

Replace the uncached memory mapping of the framebuffer with a write-
combining one. This improves performance, and avoids issues with
unaligned accesses and DC ZVA instructions performed by the accelerated
memcpy/memset routines.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c b/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c
index 2000c9bdf436..d18d6b3e1665 100644
--- a/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c
+++ b/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c
@@ -192,7 +192,7 @@ LcdPlatformGetVram (
     ASSERT_EFI_ERROR(Status);
 
     // Mark the VRAM as un-cachable. The VRAM is inside the DRAM, which is cachable.
-    Status = Cpu->SetMemoryAttributes(Cpu, *VramBaseAddress, *VramSize, EFI_MEMORY_UC);
+    Status = Cpu->SetMemoryAttributes(Cpu, *VramBaseAddress, *VramSize, EFI_MEMORY_WC);
     ASSERT_EFI_ERROR(Status);
     if (EFI_ERROR(Status)) {
       gBS->FreePool(VramBaseAddress);
-- 
2.7.4