[PULL 04/61] hw/intc/arm_gicv3: Report correct PIDR0 values for ID registers

[Peter Maydell <peter.maydell@linaro.org>]

We use the common function gicv3_idreg() to supply the CoreSight ID
register values for the GICv3 for the copies of these ID registers in
the distributor, redistributor and ITS register frames.  This isn't
quite correct, because while most of the register values are the
same, the PIDR0 value should vary to indicate which of these three
frames it is.  (You can see this and also the correct values of these
PIDR0 registers by looking at the GIC-600 or GIC-700 TRMs, for
example.)

Make gicv3_idreg() take an extra argument for the PIDR0 value.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220408141550.1271295-5-peter.maydell@linaro.org
---
 hw/intc/gicv3_internal.h   | 15 +++++++++++++--
 hw/intc/arm_gicv3_dist.c   |  2 +-
 hw/intc/arm_gicv3_its.c    |  2 +-
 hw/intc/arm_gicv3_redist.c |  2 +-
 4 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/hw/intc/gicv3_internal.h b/hw/intc/gicv3_internal.h
index 2bf1baef047..dec413f7cfa 100644
--- a/hw/intc/gicv3_internal.h
+++ b/hw/intc/gicv3_internal.h
@@ -555,7 +555,12 @@ static inline uint32_t gicv3_iidr(void)
     return 0x43b;
 }
 
-static inline uint32_t gicv3_idreg(int regoffset)
+/* CoreSight PIDR0 values for ARM GICv3 implementations */
+#define GICV3_PIDR0_DIST 0x92
+#define GICV3_PIDR0_REDIST 0x93
+#define GICV3_PIDR0_ITS 0x94
+
+static inline uint32_t gicv3_idreg(int regoffset, uint8_t pidr0)
 {
     /* Return the value of the CoreSight ID register at the specified
      * offset from the first ID register (as found in the distributor
@@ -565,7 +570,13 @@ static inline uint32_t gicv3_idreg(int regoffset)
     static const uint8_t gicd_ids[] = {
         0x44, 0x00, 0x00, 0x00, 0x92, 0xB4, 0x3B, 0x00, 0x0D, 0xF0, 0x05, 0xB1
     };
-    return gicd_ids[regoffset / 4];
+
+    regoffset /= 4;
+
+    if (regoffset == 4) {
+        return pidr0;
+    }
+    return gicd_ids[regoffset];
 }
 
 /**
diff --git a/hw/intc/arm_gicv3_dist.c b/hw/intc/arm_gicv3_dist.c
index 28d913b2114..7f6275363ea 100644
--- a/hw/intc/arm_gicv3_dist.c
+++ b/hw/intc/arm_gicv3_dist.c
@@ -557,7 +557,7 @@ static bool gicd_readl(GICv3State *s, hwaddr offset,
     }
     case GICD_IDREGS ... GICD_IDREGS + 0x2f:
         /* ID registers */
-        *data = gicv3_idreg(offset - GICD_IDREGS);
+        *data = gicv3_idreg(offset - GICD_IDREGS, GICV3_PIDR0_DIST);
         return true;
     case GICD_SGIR:
         /* WO registers, return unknown value */
diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
index 44914f25780..f8467b61ec5 100644
--- a/hw/intc/arm_gicv3_its.c
+++ b/hw/intc/arm_gicv3_its.c
@@ -1161,7 +1161,7 @@ static bool its_readl(GICv3ITSState *s, hwaddr offset,
         break;
     case GITS_IDREGS ... GITS_IDREGS + 0x2f:
         /* ID registers */
-        *data = gicv3_idreg(offset - GITS_IDREGS);
+        *data = gicv3_idreg(offset - GITS_IDREGS, GICV3_PIDR0_ITS);
         break;
     case GITS_TYPER:
         *data = extract64(s->typer, 0, 32);
diff --git a/hw/intc/arm_gicv3_redist.c b/hw/intc/arm_gicv3_redist.c
index 412a04f59cf..dc9729e8395 100644
--- a/hw/intc/arm_gicv3_redist.c
+++ b/hw/intc/arm_gicv3_redist.c
@@ -234,7 +234,7 @@ static MemTxResult gicr_readl(GICv3CPUState *cs, hwaddr offset,
         *data = cs->gicr_nsacr;
         return MEMTX_OK;
     case GICR_IDREGS ... GICR_IDREGS + 0x2f:
-        *data = gicv3_idreg(offset - GICR_IDREGS);
+        *data = gicv3_idreg(offset - GICR_IDREGS, GICV3_PIDR0_REDIST);
         return MEMTX_OK;
     default:
         return MEMTX_ERROR;
-- 
2.25.1