[PATCH] ArmPkg: Update Redistributor granularity for GICv4

[evan.lloyd@arm.com]

From: Sami Mujawar <sami.mujawar@arm.com>

Updated Redistributor base calculation to allow for the fact that
GICv4 has 2 additional 64KB frames (for VLPI and a reserved frame).
The code now tests the VLPIS bit in the GICR_TYPER register
and calculates the Redistributor granularity accordingly.

The code changes are:
  GICR_TYPER register fields, etc, added to the header.
  Loop updated to pay attention to GICR_TYPER.Last.
  Derive frame "stride" size from GICR_TYPER.VLPIS.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Evan Lloyd <evan.lloydr@arm.com>
---
Code is available at:
https://github.com/EvanLloyd/tianocore/tree/639_gicv4_v1

 ArmPkg/Include/Library/ArmGicLib.h | 17 ++++++++-
 ArmPkg/Drivers/ArmGic/ArmGicLib.c  | 40 +++++++++++++-------
 2 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/ArmPkg/Include/Library/ArmGicLib.h b/ArmPkg/Include/Library/ArmGicLib.h
index 4364f3ffef464596f64cf59881d703cf54cf0ddd..079489fe76ab481915ce9da3702d351fd3cb5f0e 100644
--- a/ArmPkg/Include/Library/ArmGicLib.h
+++ b/ArmPkg/Include/Library/ArmGicLib.h
@@ -55,12 +55,25 @@
 // GIC Redistributor
 //
 
-#define ARM_GICR_CTLR_FRAME_SIZE    SIZE_64KB
-#define ARM_GICR_SGI_PPI_FRAME_SIZE SIZE_64KB
+#define ARM_GICR_CTLR_FRAME_SIZE         SIZE_64KB
+#define ARM_GICR_SGI_PPI_FRAME_SIZE      SIZE_64KB
+#define ARM_GICR_SGI_VLPI_FRAME_SIZE     SIZE_64KB
+#define ARM_GICR_SGI_RESERVED_FRAME_SIZE SIZE_64KB
 
 // GIC Redistributor Control frame
 #define ARM_GICR_TYPER          0x0008  // Redistributor Type Register
 
+// GIC Redistributor TYPER bit assignments
+#define ARM_GICR_TYPER_PLPIS        (1 << 0)    // Physical LPIs
+#define ARM_GICR_TYPER_VLPIS        (1 << 1)    // Virtual LPIs
+#define ARM_GICR_TYPER_DIRECTLPI    (1 << 3)    // Direct LPIs
+#define ARM_GICR_TYPER_LAST         (1 << 4)    // Last Redistributor in series
+#define ARM_GICR_TYPER_DPGS         (1 << 5)    // Disable Processor Group
+                                                // Selection Support
+#define ARM_GICR_TYPER_PROCNO       (0xFFFF << 8)      // Processor Number
+#define ARM_GICR_TYPER_COMMONLPIAFF (0x3 << 24)        // Common LPI Affinity
+#define ARM_GICR_TYPER_AFFINITY     (0xFFFFFFFF << 32) // Redistributor Affinity
+
 // GIC SGI & PPI Redistributor frame
 #define ARM_GICR_ISENABLER      0x0100  // Interrupt Set-Enable Registers
 #define ARM_GICR_ICENABLER      0x0180  // Interrupt Clear-Enable Registers
diff --git a/ArmPkg/Drivers/ArmGic/ArmGicLib.c b/ArmPkg/Drivers/ArmGic/ArmGicLib.c
index e658e9bff5d8107b3914bdf1e9e1e51a4e4d4cd7..b51d2b3ec55d277e36835669956b4dd866cfc5c6 100644
--- a/ArmPkg/Drivers/ArmGic/ArmGicLib.c
+++ b/ArmPkg/Drivers/ArmGic/ArmGicLib.c
@@ -1,6 +1,6 @@
 /** @file
 *
-*  Copyright (c) 2011-2015, ARM Limited. All rights reserved.
+*  Copyright (c) 2011-2016, ARM Limited. All rights reserved.
 *
 *  This program and the accompanying materials
 *  are licensed and made available under the terms and conditions of the BSD License
@@ -19,6 +19,16 @@
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
 
+// In GICv3, there are 2 x 64KB frames:
+// Redistributor control frame + SGI Control & Generation frame
+#define GIC_V3_REDISTRIBUTOR_GRANULARITY  (ARM_GICR_CTLR_FRAME_SIZE \
+                                           + ARM_GICR_SGI_PPI_FRAME_SIZE)
+// In GICv4, there are an additional 2 x 64KB frames:
+// VLPI frame + Reserved page frame
+#define GIC_V4_REDISTRIBUTOR_GRANULARITY  (GIC_V3_REDISTRIBUTOR_GRANULARITY \
+                                           + ARM_GICR_SGI_VLPI_FRAME_SIZE \
+                                           + ARM_GICR_SGI_RESERVED_FRAME_SIZE)
+
 /**
  *
  * Return whether the Source interrupt index refers to a shared interrupt (SPI)
@@ -40,6 +50,7 @@ SourceIsSpi (
  *
  * @retval Base address of the associated GIC Redistributor
  */
+
 STATIC
 UINTN
 GicGetCpuRedistributorBase (
@@ -47,37 +58,38 @@ GicGetCpuRedistributorBase (
   IN ARM_GIC_ARCH_REVISION Revision
   )
 {
-  UINTN Index;
   UINTN MpId;
-  UINTN CpuAffinity;
-  UINTN Affinity;
-  UINTN GicRedistributorGranularity;
+  UINT32 CpuAffinity;
+  UINT32 Affinity;
   UINTN GicCpuRedistributorBase;
+  UINT64 GicRTyper;
 
   MpId = ArmReadMpidr ();
   // Define CPU affinity as Affinity0[0:8], Affinity1[9:15], Affinity2[16:23], Affinity3[24:32]
   // whereas Affinity3 is defined at [32:39] in MPIDR
   CpuAffinity = (MpId & (ARM_CORE_AFF0 | ARM_CORE_AFF1 | ARM_CORE_AFF2)) | ((MpId & ARM_CORE_AFF3) >> 8);
 
-  if (Revision == ARM_GIC_ARCH_REVISION_3) {
-    // 2 x 64KB frame: Redistributor control frame + SGI Control & Generation frame
-    GicRedistributorGranularity = ARM_GICR_CTLR_FRAME_SIZE + ARM_GICR_SGI_PPI_FRAME_SIZE;
-  } else {
+  if (Revision < ARM_GIC_ARCH_REVISION_3) {
     ASSERT_EFI_ERROR (EFI_UNSUPPORTED);
     return 0;
   }
 
   GicCpuRedistributorBase = GicRedistributorBase;
 
-  for (Index = 0; Index < PcdGet32 (PcdCoreCount); Index++) {
-    Affinity = MmioRead64 (GicCpuRedistributorBase + ARM_GICR_TYPER) >> 32;
+  do {
+    GicRTyper = MmioRead64 (GicCpuRedistributorBase + ARM_GICR_TYPER);
+    Affinity = GicRTyper >> 32;
     if (Affinity == CpuAffinity) {
       return GicCpuRedistributorBase;
     }
 
-    // Move to the next GIC Redistributor frame
-    GicCpuRedistributorBase += GicRedistributorGranularity;
-  }
+    // Move to the next GIC Redistributor frame.
+    // The GIC specification does not forbid a mixture of v3 and v4 frames,
+    // so we test VLPIS for each frame.
+    GicCpuRedistributorBase += ((ARM_GICR_TYPER_VLPIS & GicRTyper)
+                                ? GIC_V4_REDISTRIBUTOR_GRANULARITY
+                                : GIC_V3_REDISTRIBUTOR_GRANULARITY);
+  } while (0 == (GicRTyper & ARM_GICR_TYPER_LAST));
 
   // The Redistributor has not been found for the current CPU
   ASSERT_EFI_ERROR (EFI_NOT_FOUND);
-- 
Guid("CE165669-3EF3-493F-B85D-6190EE5B9759")