diff mbox series

[edk2,v2,5/5] ArmPlatformPkg/PL111LcdArmVExpressLib: use write-combine mapping for VRAM

Message ID 20170406131551.3322-6-ard.biesheuvel@linaro.org
State Accepted
Commit a30d5f9f90e64c25eb1d4c6adad1ccae682ca59f
Headers show
Series ArmPlatformPkg: map VRAM using memory semantics | expand

Commit Message

Ard Biesheuvel April 6, 2017, 1:15 p.m. UTC 
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.

Instead of manipulating the memory attributes directly, use the
SetMemorySpaceAttributes() DXE services, which validates the attributes
against the capabilities of the region before making the actual change.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c      | 12 ++++--------
 ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpressLib.inf |  3 ++-
 2 files changed, 6 insertions(+), 9 deletions(-)

-- 
2.9.3

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diff mbox series

Patch

diff --git a/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c b/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c
index a8125e81daac..3f3ceb3d2fa8 100644
--- a/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c
+++ b/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpress.c
@@ -17,10 +17,10 @@ 
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
 #include <Library/DebugLib.h>
+#include <Library/DxeServicesTableLib.h>
 #include <Library/LcdPlatformLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 
-#include <Protocol/Cpu.h>
 #include <Protocol/EdidDiscovered.h>
 #include <Protocol/EdidActive.h>
 
@@ -165,7 +165,6 @@  LcdPlatformGetVram (
   )
 {
   EFI_STATUS              Status;
-  EFI_CPU_ARCH_PROTOCOL  *Cpu;
 
   Status = EFI_SUCCESS;
 
@@ -187,12 +186,9 @@  LcdPlatformGetVram (
       return Status;
     }
 
-    // Ensure the Cpu architectural protocol is already installed
-    Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&Cpu);
-    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);
+    // Mark the VRAM as write-combining. The VRAM is inside the DRAM, which is cacheable.
+    Status = gDS->SetMemorySpaceAttributes (*VramBaseAddress, *VramSize,
+                    EFI_MEMORY_WC);
     ASSERT_EFI_ERROR(Status);
     if (EFI_ERROR(Status)) {
       gBS->FreePages (*VramBaseAddress, EFI_SIZE_TO_PAGES(*VramSize));
diff --git a/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpressLib.inf b/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpressLib.inf
index d1978e7110d5..658558ab1523 100644
--- a/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpressLib.inf
+++ b/ArmPlatformPkg/ArmVExpressPkg/Library/PL111LcdArmVExpressLib/PL111LcdArmVExpressLib.inf
@@ -31,8 +31,9 @@  [Packages]
   ArmPlatformPkg/ArmPlatformPkg.dec
 
 [LibraryClasses]
-  BaseLib
   ArmPlatformSysConfigLib
+  BaseLib
+  DxeServicesTableLib
 
 [Protocols]
   gEfiEdidDiscoveredProtocolGuid                # Produced