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

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
@@ -42,8 +43,15 @@ InterruptDxeInitialize (
   )
 {
   EFI_STATUS            Status;
+  ARM_GIC_ARCH_REVISION Revision;
 
+  Revision = ArmGicGetSupportedArchRevision ();
+
+  if (Revision == ARM_GIC_ARCH_REVISION_2) {
     Status = GicV2DxeInitialize (ImageHandle, SystemTable);
+  } else {
+    Status = EFI_UNSUPPORTED;
+  }
 
   return Status;
 }

ArmPkg/Drivers/ArmGic/ArmGicLib.c

@@ -19,6 +19,15 @@
 
 #include "GicV2/ArmGicV2Lib.h"
 
+ARM_GIC_ARCH_REVISION
+EFIAPI
+ArmGicGetSupportedArchRevision (
+  VOID
+  )
+{
+  return ARM_GIC_ARCH_REVISION_2;
+}
+
 UINTN
 EFIAPI
 ArmGicGetInterfaceIdentification (
@@ -71,16 +80,23 @@ ArmGicAcknowledgeInterrupt (
   )
 {
   UINTN Value;
+  ARM_GIC_ARCH_REVISION Revision;
 
+  Revision = ArmGicGetSupportedArchRevision ();
+  if (Revision == ARM_GIC_ARCH_REVISION_2) {
     Value = ArmGicV2AcknowledgeInterrupt (GicInterruptInterfaceBase);
-
     // InterruptId is required for the caller to know if a valid or spurious
     // interrupt has been read
     ASSERT (InterruptId != NULL);
-
     if (InterruptId != NULL) {
       *InterruptId = Value & ARM_GIC_ICCIAR_ACKINTID;
     }
+  } else {
+    ASSERT_EFI_ERROR (EFI_UNSUPPORTED);
+    // Report Spurious interrupt which is what the above controllers would
+    // return if no interrupt was available
+    Value = 1023;
+  }
 
   return Value;
 }
@@ -92,7 +108,14 @@ ArmGicEndOfInterrupt (
   IN UINTN                  Source
   )
 {
+  ARM_GIC_ARCH_REVISION Revision;
+
+  Revision = ArmGicGetSupportedArchRevision ();
+  if (Revision == ARM_GIC_ARCH_REVISION_2) {
     ArmGicV2EndOfInterrupt (GicInterruptInterfaceBase, Source);
+  } else {
+    ASSERT_EFI_ERROR (EFI_UNSUPPORTED);
+  }
 }
 
 VOID
@@ -164,7 +187,14 @@ ArmGicEnableInterruptInterface (
   IN  INTN          GicInterruptInterfaceBase
   )
 {
-  return ArmGicV2EnableInterruptInterface (GicInterruptInterfaceBase);
+  ARM_GIC_ARCH_REVISION Revision;
+
+  Revision = ArmGicGetSupportedArchRevision ();
+  if (Revision == ARM_GIC_ARCH_REVISION_2) {
+    ArmGicV2EnableInterruptInterface (GicInterruptInterfaceBase);
+  } else {
+    ASSERT_EFI_ERROR (EFI_UNSUPPORTED);
+  }
 }
 
 VOID
@@ -173,5 +203,12 @@ ArmGicDisableInterruptInterface (
   IN  INTN          GicInterruptInterfaceBase
   )
 {
-  return ArmGicV2DisableInterruptInterface (GicInterruptInterfaceBase);
+  ARM_GIC_ARCH_REVISION Revision;
+
+  Revision = ArmGicGetSupportedArchRevision ();
+  if (Revision == ARM_GIC_ARCH_REVISION_2) {
+    ArmGicV2DisableInterruptInterface (GicInterruptInterfaceBase);
+  } else {
+    ASSERT_EFI_ERROR (EFI_UNSUPPORTED);
+  }
 }

ArmPkg/Drivers/ArmGic/ArmGicLib.inf

@@ -27,6 +27,7 @@
   GicV2/ArmGicV2NonSecLib.c
 
 [LibraryClasses]
+  DebugLib
   IoLib
 
 [Packages]

ArmPkg/Include/Library/ArmGicLib.h

@@ -18,6 +18,9 @@
 //
 // GIC definitions
 //
+typedef enum {
+  ARM_GIC_ARCH_REVISION_2
+} ARM_GIC_ARCH_REVISION;
 
 //
 // GIC Distributor
@@ -76,6 +79,12 @@
 #define ARM_GIC_ICCIIDR_GET_REVISION(IccIidr)     (((IccIidr) >> 12) & 0xF)
 #define ARM_GIC_ICCIIDR_GET_IMPLEMENTER(IccIidr)  ((IccIidr) & 0xFFF)
 
+ARM_GIC_ARCH_REVISION
+EFIAPI
+ArmGicGetSupportedArchRevision (
+  VOID
+  );
+
 UINTN
 EFIAPI
 ArmGicGetInterfaceIdentification (