ArmPkg/Drivers/ArmGicDxe: Add ESPI support for GICv3

- Add ESPI configuration to GICv3.
- Remove mNumGicInterrupts and replace with GicIsValidSource(),
  GicGetGreatestIntid() APIs. mNumGicInterrupts is still used internally
  in GICv2.
- Tested on qemu with the BSA test suite.

Signed-off-by: Nick Graves <[email protected]>

Author: NicholasGraves

ArmPkg/Drivers/ArmGicDxe/ArmGicCommonDxe.c

@@ -14,12 +14,23 @@ EFI_HANDLE  gHardwareInterruptHandle = NULL;
 // Notifications
 EFI_EVENT  EfiExitBootServicesEvent = (EFI_EVENT)NULL;
 
-// Maximum Number of Interrupts
-UINTN  mGicNumInterrupts = 0;
-
 HARDWARE_INTERRUPT_HANDLER  *gRegisteredInterruptHandlers = NULL;
 EFI_CPU_ARCH_PROTOCOL       *gCpuArch;
 
+/**
+ *
+ * Return whether the Source interrupt index refers to an extended shared
+ * interrupt (ESPI)
+ */
+STATIC
+BOOLEAN
+SourceIsEspi (
+  IN UINTN  Source
+  )
+{
+  return Source >= ARM_GIC_ARCH_EXT_SPI_MIN && Source <= ARM_GIC_ARCH_EXT_SPI_MAX;
+}
+
 /**
   Calculate GICD_ICFGRn base address and corresponding bit
   field Int_config[1] of the GIC distributor register.
@@ -38,18 +49,25 @@ GicGetDistributorIcfgBaseAndBit (
   OUT UINTN                     *Config1Bit
   )
 {
-  UINTN  RegIndex;
-  UINTN  Field;
+  UINTN                      RegIndex;
+  UINTN                      Field;
+  UINTN                      RegOffset;
+  HARDWARE_INTERRUPT_SOURCE  AdjustedSource;
 
-  if (Source >= mGicNumInterrupts) {
-    ASSERT (Source < mGicNumInterrupts);
+  if (!GicIsValidSource (Source)) {
+    ASSERT (FALSE);
     return EFI_UNSUPPORTED;
   }
 
-  RegIndex    = Source / ARM_GIC_ICDICFR_F_STRIDE; // NOTE: truncation is significant
-  Field       = Source % ARM_GIC_ICDICFR_F_STRIDE;
+  // Translate ESPI sources into the SPI range for indexing purposes.
+  AdjustedSource = Source & ~(ARM_GIC_ARCH_EXT_SPI_MIN);
+
+  RegOffset = (SourceIsEspi (Source)) ? ARM_GIC_ICDICFR_E : ARM_GIC_ICDICFR;
+
+  RegIndex    = AdjustedSource / ARM_GIC_ICDICFR_F_STRIDE; // NOTE: truncation is significant
+  Field       = AdjustedSource % ARM_GIC_ICDICFR_F_STRIDE;
   *RegAddress = (UINTN)PcdGet64 (PcdGicDistributorBase)
-                + ARM_GIC_ICDICFR
+                + RegOffset
                 + (ARM_GIC_ICDICFR_BYTES * RegIndex);
   *Config1Bit = ((Field * ARM_GIC_ICDICFR_F_WIDTH)
                  + ARM_GIC_ICDICFR_F_CONFIG1_BIT);
@@ -76,7 +94,7 @@ RegisterInterruptSource (
   IN HARDWARE_INTERRUPT_HANDLER       Handler
   )
 {
-  if (Source >= mGicNumInterrupts) {
+  if (!GicIsValidSource (Source)) {
     ASSERT (FALSE);
     return EFI_UNSUPPORTED;
   }
@@ -107,9 +125,12 @@ InstallAndRegisterInterruptService (
   IN EFI_EVENT_NOTIFY                  ExitBootServicesEvent
   )
 {
-  EFI_STATUS   Status;
+  EFI_STATUS  Status;
+
+  UINTN  NumIntids = GicGetGreatestIntid () + 1;
+
   CONST UINTN  RihArraySize =
-    (sizeof (HARDWARE_INTERRUPT_HANDLER) * mGicNumInterrupts);
+    (sizeof (HARDWARE_INTERRUPT_HANDLER) * NumIntids);
 
   // Initialize the array for the Interrupt Handlers
   gRegisteredInterruptHandlers = AllocateZeroPool (RihArraySize);

ArmPkg/Drivers/ArmGicDxe/ArmGicDxe.h

@@ -21,7 +21,6 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Protocol/HardwareInterrupt.h>
 #include <Protocol/HardwareInterrupt2.h>
 
-extern UINTN                       mGicNumInterrupts;
 extern HARDWARE_INTERRUPT_HANDLER  *gRegisteredInterruptHandlers;
 extern EFI_CPU_ARCH_PROTOCOL       *gCpuArch;
 
@@ -76,6 +75,30 @@ GicGetDistributorIcfgBaseAndBit (
   OUT UINTN                     *Config1Bit
   );
 
+/**
+  Returns true if the Source is valid.
+
+  @param Source       Hardware source of the interrupt.
+
+  @retval True if valid, false otherwise.
+ */
+BOOLEAN
+EFIAPI
+GicIsValidSource (
+  IN HARDWARE_INTERRUPT_SOURCE  Source
+  );
+
+/**
+  Returns the greatest valid intid.
+
+  @retval The greatest valid intid.
+ */
+HARDWARE_INTERRUPT_SOURCE
+EFIAPI
+GicGetGreatestIntid (
+  VOID
+  );
+
 UINT32
 EFIAPI
 ArmGicGetInterfaceIdentification (

ArmPkg/Drivers/ArmGicDxe/GicV2/ArmGicV2Dxe.c

@@ -19,6 +19,7 @@ Module Name:
 #include <Library/ArmGicLib.h>
 
 #include "ArmGicDxe.h"
+#include "Protocol/HardwareInterrupt.h"
 
 #define ARM_GIC_DEFAULT_PRIORITY  0x80
 
@@ -36,6 +37,9 @@ extern EFI_HARDWARE_INTERRUPT2_PROTOCOL  gHardwareInterrupt2V2Protocol;
 STATIC UINTN  mGicInterruptInterfaceBase;
 STATIC UINTN  mGicDistributorBase;
 
+// Maximum Number of Interrupts
+STATIC UINTN  mGicNumInterrupts;
+
 STATIC
 VOID
 ArmGicEnableInterrupt (
@@ -613,3 +617,21 @@ GicV2DxeInitialize (
 
   return Status;
 }
+
+BOOLEAN
+EFIAPI
+GicIsValidSource (
+  IN HARDWARE_INTERRUPT_SOURCE  Source
+  )
+{
+  return Source < mGicNumInterrupts;
+}
+
+HARDWARE_INTERRUPT_SOURCE
+EFIAPI
+GicGetGreatestIntid (
+  VOID
+  )
+{
+  return mGicNumInterrupts - 1;
+}