ArmPkg/ArmGic: Introduced ArmGicGetSupportedArchRevision()

This function returns the revision of the GIC Architecture.
Some GICv3 controllers can work in GICv2 mode. Switching to an
older GIC revision is driven by the higher level exception level.
This function allows code to support any GIC revision at runtime.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16231 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 10 insertions, 2 deletions

diff --git a/ArmPkg/Drivers/ArmGic/ArmGicDxe.c b/ArmPkg/Drivers/ArmGic/ArmGicDxe.c
index 37c32504a5..8be2d6fe5e 100644
--- a/ArmPkg/Drivers/ArmGic/ArmGicDxe.c
+++ b/ArmPkg/Drivers/ArmGic/ArmGicDxe.c
@@ -33,6 +33,7 @@ Abstract:
   @retval EFI_SUCCESS           Protocol registered

   @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure

   @retval EFI_DEVICE_ERROR      Hardware problems

+  @retval EFI_UNSUPPORTED       GIC version not supported

 

 **/

 EFI_STATUS

@@ -41,9 +42,16 @@ InterruptDxeInitialize (
   IN EFI_SYSTEM_TABLE   *SystemTable

   )

 {

-  EFI_STATUS  Status;

+  EFI_STATUS            Status;

+  ARM_GIC_ARCH_REVISION Revision;

 

-  Status = GicV2DxeInitialize (ImageHandle, SystemTable);

+  Revision = ArmGicGetSupportedArchRevision ();

+

+  if (Revision == ARM_GIC_ARCH_REVISION_2) {

+    Status = GicV2DxeInitialize (ImageHandle, SystemTable);

+  } else {

+    Status = EFI_UNSUPPORTED;

+  }

 

   return Status;

 }