[PATCH 1/2] ArmPlatformPkg/HdLcdArmVExpressLib: 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/HdLcdArmVExpressLib/HdLcdArmVExpress.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ArmPlatformPkg/ArmVExpressPkg/Library/HdLcdArmVExpressLib/HdLcdArmVExpress.c b/ArmPlatformPkg/ArmVExpressPkg/Library/HdLcdArmVExpressLib/HdLcdArmVExpress.c
index a57846715ed7..d6d47545c824 100644
--- a/ArmPlatformPkg/ArmVExpressPkg/Library/HdLcdArmVExpressLib/HdLcdArmVExpress.c
+++ b/ArmPlatformPkg/ArmVExpressPkg/Library/HdLcdArmVExpressLib/HdLcdArmVExpress.c
@@ -143,7 +143,7 @@ LcdPlatformGetVram (
   ASSERT_EFI_ERROR(Status);
 
   // Mark the VRAM as un-cacheable. The VRAM is inside the DRAM, which is cacheable.
-  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