ArmPkg/ArmDmaLib: use DMA buffer alignment from CPU arch protocol

Instead of depending on ArmLib to retrieve the CWG directly, use
the DMA buffer alignment exposed by the CPU arch protocol. This
removes our dependency on ArmLib, which makes the library a bit
more architecture independent.

While we're in there, rename gCpu to mCpu to better reflect its
local scope, and reflow some lines that we're modifying anyway.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

2 files changed, 8 insertions, 12 deletions

diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
index 4476e8b46..e836feff1 100644
--- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
+++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c
@@ -22,7 +22,6 @@
 #include <Library/UncachedMemoryAllocationLib.h>

 #include <Library/IoLib.h>

 #include <Library/BaseMemoryLib.h>

-#include <Library/ArmLib.h>

 

 #include <Protocol/Cpu.h>

 

@@ -36,8 +35,7 @@ typedef struct {
 

 

 

-EFI_CPU_ARCH_PROTOCOL      *gCpu;

-UINTN                      gCacheAlignment = 0;

+STATIC EFI_CPU_ARCH_PROTOCOL      *mCpu;

 

 /**

   Provides the DMA controller-specific addresses needed to access system memory.

@@ -90,8 +88,8 @@ DmaMap (
     return  EFI_OUT_OF_RESOURCES;

   }

 

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

-      ((*NumberOfBytes & (gCacheAlignment - 1)) != 0)) {

+  if ((((UINTN)HostAddress & (mCpu->DmaBufferAlignment - 1)) != 0) ||

+      ((*NumberOfBytes & (mCpu->DmaBufferAlignment - 1)) != 0)) {

 

     // Get the cacheability of the region

     Status = gDS->GetMemorySpaceDescriptor (*DeviceAddress, &GcdDescriptor);

@@ -153,7 +151,8 @@ DmaMap (
     DEBUG_CODE_END ();

 

     // Flush the Data Cache (should not have any effect if the memory region is uncached)

-    gCpu->FlushDataCache (gCpu, *DeviceAddress, *NumberOfBytes, EfiCpuFlushTypeWriteBackInvalidate);

+    mCpu->FlushDataCache (mCpu, *DeviceAddress, *NumberOfBytes,

+            EfiCpuFlushTypeWriteBackInvalidate);

   }

 

   Map->HostAddress   = (UINTN)HostAddress;

@@ -217,7 +216,8 @@ DmaUnmap (
       //

       // Make sure we read buffer from uncached memory and not the cache

       //

-      gCpu->FlushDataCache (gCpu, Map->HostAddress, Map->NumberOfBytes, EfiCpuFlushTypeInvalidate);

+      mCpu->FlushDataCache (mCpu, Map->HostAddress, Map->NumberOfBytes,

+              EfiCpuFlushTypeInvalidate);

     }

   }

 

@@ -317,11 +317,9 @@ ArmDmaLibConstructor (
   EFI_STATUS              Status;

 

   // Get the Cpu protocol for later use

-  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&gCpu);

+  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&mCpu);

   ASSERT_EFI_ERROR(Status);

 

-  gCacheAlignment = ArmCacheWritebackGranule ();

-

   return Status;

 }

 

diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf
index 95c13006e..31de3cfd8 100644
--- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf
+++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.inf
@@ -37,8 +37,6 @@
   UncachedMemoryAllocationLib

   IoLib

   BaseMemoryLib

-  ArmLib

-

 

 [Protocols]

   gEfiCpuArchProtocolGuid