From 3f5aa1932f6a453981d9cab353b0340268b97808 Mon Sep 17 00:00:00 2001
From: oliviermartin <oliviermartin@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 31 Aug 2012 16:24:01 +0000
Subject: [PATCH] ArmPkg: Changed Uncached System Memory from EFI_MEMORY_UC to
 EFI_MEMORY_WC

EFI_MEMORY_UC is mapped to Strongly Ordered memory while EFI_MEMORY_WC is
mapped to Uncached Normal/System memory.
This change improve performance while accessing uncached regions in the
System Memory.


Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Eugene Cohen <eugene@hp.com>
Reviewed-by: Olivier Martin <oliviermartin@arm.com



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13693 6f19259b-4bc3-4df7-8a09-765794883524
---
 ArmPkg/Library/ArmDmaLib/ArmDmaLib.c                        | 6 ++++--
 .../UncachedMemoryAllocationLib.c                           | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
index 4764b4237a..074e3c1255 100755
--- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
+++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
@@ -102,7 +102,9 @@ DmaMap (
     }
 
     // If the mapped buffer is not an uncached buffer
-    if (GcdDescriptor.Attributes != EFI_MEMORY_UC) {
+    if ( (GcdDescriptor.Attributes != EFI_MEMORY_WC) &&
+         (GcdDescriptor.Attributes != EFI_MEMORY_UC) )
+    {
       //
       // If the buffer does not fill entire cache lines we must double buffer into
       // uncached memory. Device (PCI) address becomes uncached page.
@@ -129,7 +131,7 @@ DmaMap (
 
     if ((Operation == MapOperationBusMasterRead) || (Operation == MapOperationBusMasterCommonBuffer)) {
       // In case the buffer is used for instance to send command to a PCI controller, we must ensure the memory is uncached
-      Status = gDS->SetMemorySpaceAttributes (ALIGN_VALUE(*DeviceAddress - BASE_4KB - 1,BASE_4KB), ALIGN_VALUE(*NumberOfBytes,BASE_4KB), EFI_MEMORY_UC);
+      Status = gDS->SetMemorySpaceAttributes (ALIGN_VALUE(*DeviceAddress - BASE_4KB - 1,BASE_4KB), ALIGN_VALUE(*NumberOfBytes,BASE_4KB), EFI_MEMORY_WC);
       ASSERT_EFI_ERROR (Status);
     }
   }
diff --git a/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c b/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c
index 657268a288..4db93dbd2d 100644
--- a/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c
+++ b/ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c
@@ -245,7 +245,7 @@ UncachedInternalAllocateAlignedPages (
     gAttributes = Descriptor.Attributes;
   }
   
-  Status = gDS->SetMemorySpaceAttributes (Memory, EFI_PAGES_TO_SIZE (Pages), EFI_MEMORY_UC);
+  Status = gDS->SetMemorySpaceAttributes (Memory, EFI_PAGES_TO_SIZE (Pages), EFI_MEMORY_WC);
   ASSERT_EFI_ERROR (Status);
   
   return (VOID *)(UINTN)Memory;