Fix issue in DmaMap with buffers that are smaller than a cache line. Also make any buffer that is not an even quanta of cache lines double buffer.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10654 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 6 insertions, 3 deletions

diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
index 9467fa5b4..7fef208c7 100755
--- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
+++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
@@ -95,7 +95,12 @@ DmaMap (
   

   *Mapping = Map;

 

-  if (((UINTN)HostAddress & (gCacheAlignment - 1)) != 0) {

+  if ((((UINTN)HostAddress & (gCacheAlignment - 1)) != 0) ||

+      ((*NumberOfBytes % gCacheAlignment) != 0)) {

+    //

+    // If the buffer does not fill entire cache lines we must double buffer into 

+    // uncached memory. Device (PCI) address becomes uncached page.

+    //

     Map->DoubleBuffer  = TRUE;

     Status = DmaAllocateBuffer (EfiBootServicesData, EFI_SIZE_TO_PAGES (*NumberOfBytes), &Buffer);

     if (EFI_ERROR (Status)) {

@@ -108,8 +113,6 @@ DmaMap (
     Map->DoubleBuffer  = FALSE;

   }

 

-  *NumberOfBytes &= *NumberOfBytes & ~(gCacheAlignment - 1); // Only do it on full cache lines

-  

   Map->HostAddress   = (UINTN)HostAddress;

   Map->DeviceAddress = *DeviceAddress;

   Map->NumberOfBytes = *NumberOfBytes;