[RFC,2/4] hw/intc: add helper function to determine gicv3 redistributor size

Commit Message

Leif Lindholm Jan. 24, 2021, 2:53 a.m. UTC

GICv3 sets aside 128K for each redistributor block, whereas GICv4 sets
aside 256K. To enable use of the gicv3 model for gicv4, abstract this
away as the helper function gicv3_redist_size() and replace the current
hardcoded locations with calls to this function.

Signed-off-by: Leif Lindholm <[e-mail]>
---
 hw/intc/arm_gicv3_common.c         |  2 +-
 hw/intc/arm_gicv3_redist.c         | 13 +++++++++----
 include/hw/intc/arm_gicv3_common.h |  3 +++
 3 files changed, 13 insertions(+), 5 deletions(-)

Comments

Peter Maydell Feb. 2, 2021, 10:27 a.m. UTC | #1

On Sun, 24 Jan 2021 at 02:53, Leif Lindholm <[e-mail]> wrote:
>
> GICv3 sets aside 128K for each redistributor block, whereas GICv4 sets
> aside 256K. To enable use of the gicv3 model for gicv4, abstract this
> away as the helper function gicv3_redist_size() and replace the current
> hardcoded locations with calls to this function.
>
> Signed-off-by: Leif Lindholm <[e-mail]>
> ---

We're going to need this at some point and it's nicer than those
hard-coded 0x20000s.

Reviewed-by: Peter Maydell <[e-mail]>

thanks
-- PMM

Patch

diff --git a/hw/intc/arm_gicv3_common.c b/hw/intc/arm_gicv3_common.c
index 7365d24873..a8510b39a1 100644
--- a/hw/intc/arm_gicv3_common.c
+++ b/hw/intc/arm_gicv3_common.c
@@ -299,7 +299,7 @@  void gicv3_init_irqs_and_mmio(GICv3State *s, qemu_irq_handler handler,
 
         memory_region_init_io(&s->iomem_redist[i], OBJECT(s),
                               ops ? &ops[1] : NULL, s, name,
-                              s->redist_region_count[i] * GICV3_REDIST_SIZE);
+                              s->redist_region_count[i] * gicv3_redist_size(s));
         sysbus_init_mmio(sbd, &s->iomem_redist[i]);
         g_free(name);
     }
diff --git a/hw/intc/arm_gicv3_redist.c b/hw/intc/arm_gicv3_redist.c
index 8645220d61..544f4d82ff 100644
--- a/hw/intc/arm_gicv3_redist.c
+++ b/hw/intc/arm_gicv3_redist.c
@@ -14,6 +14,11 @@ 
 #include "trace.h"
 #include "gicv3_internal.h"
 
+int gicv3_redist_size(GICv3State *s)
+{
+    return (s->revision == 3 ? GICV3_REDIST_SIZE : GICV4_REDIST_SIZE);
+}
+
 static uint32_t mask_group(GICv3CPUState *cs, MemTxAttrs attrs)
 {
     /* Return a 32-bit mask which should be applied for this set of 32
@@ -429,8 +434,8 @@  MemTxResult gicv3_redist_read(void *opaque, hwaddr offset, uint64_t *data,
      * want to allow splitting of redistributor pages into several
      * blocks so we can support more CPUs.
      */
-    cpuidx = offset / 0x20000;
-    offset %= 0x20000;
+    cpuidx = offset / gicv3_redist_size(s);
+    offset %= gicv3_redist_size(s);
     assert(cpuidx < s->num_cpu);
 
     cs = &s->cpu[cpuidx];
@@ -486,8 +491,8 @@  MemTxResult gicv3_redist_write(void *opaque, hwaddr offset, uint64_t data,
      * want to allow splitting of redistributor pages into several
      * blocks so we can support more CPUs.
      */
-    cpuidx = offset / 0x20000;
-    offset %= 0x20000;
+    cpuidx = offset / gicv3_redist_size(s);
+    offset %= gicv3_redist_size(s);
     assert(cpuidx < s->num_cpu);
 
     cs = &s->cpu[cpuidx];
diff --git a/include/hw/intc/arm_gicv3_common.h b/include/hw/intc/arm_gicv3_common.h
index 91491a2f66..ab88d14867 100644
--- a/include/hw/intc/arm_gicv3_common.h
+++ b/include/hw/intc/arm_gicv3_common.h
@@ -37,6 +37,7 @@ 
 #define GICV3_MAXSPI (GICV3_MAXIRQ - GIC_INTERNAL)
 
 #define GICV3_REDIST_SIZE 0x20000
+#define GICV4_REDIST_SIZE (GICV3_REDIST_SIZE + 0x20000)
 
 /* Number of SGI target-list bits */
 #define GICV3_TARGETLIST_BITS 16
@@ -295,4 +296,6 @@  struct ARMGICv3CommonClass {
 void gicv3_init_irqs_and_mmio(GICv3State *s, qemu_irq_handler handler,
                               const MemoryRegionOps *ops, Error **errp);
 
+int gicv3_redist_size(GICv3State *s);
+
 #endif