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
This commit is contained in:
oliviermartin 2012-08-31 16:24:01 +00:00
parent f1660263de
commit 3f5aa1932f
2 changed files with 5 additions and 3 deletions

View File

@ -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);
}
}

View File

@ -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;