diff mbox

[for-2.4] hw/intc/arm_gic_common.c: Reset all registers

Message ID 1435602345-32210-1-git-send-email-peter.maydell@linaro.org
State Superseded
Headers show

Commit Message

Peter Maydell June 29, 2015, 6:25 p.m. UTC
The arm_gic_common reset function was missing reset code for
several of the GIC's state fields:
 * bpr[]
 * abpr[]
 * priority1[]
 * priority2[]
 * sgi_pending[]
 * irq_target[] (SMP configurations only)

These probably went unnoticed because most guests will either
never touch them, or will write to them in the process of
configuring the GIC before enabling interrupts.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
The reason for using loops to set these array elements to 0 rather
than using memset() is that to support "directly boot a kernel in
NS on a TZ-aware GIC and CPU" we need to support resetting the
priority registers (most notably the CPU priority mask) to 0x80
rather than 0.

I found this via code review rather than because it triggered
any kind of misbehaviour.

last_active[] does not need any reset, I believe.

 hw/intc/arm_gic_common.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

Comments

Peter Maydell July 3, 2015, 5:03 p.m. UTC | #1
On 29 June 2015 at 19:25, Peter Maydell <peter.maydell@linaro.org> wrote:
> The arm_gic_common reset function was missing reset code for
> several of the GIC's state fields:
>  * bpr[]
>  * abpr[]
>  * priority1[]
>  * priority2[]
>  * sgi_pending[]
>  * irq_target[] (SMP configurations only)
>
> These probably went unnoticed because most guests will either
> never touch them, or will write to them in the process of
> configuring the GIC before enabling interrupts.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> The reason for using loops to set these array elements to 0 rather
> than using memset() is that to support "directly boot a kernel in
> NS on a TZ-aware GIC and CPU" we need to support resetting the
> priority registers (most notably the CPU priority mask) to 0x80
> rather than 0.
>
> I found this via code review rather than because it triggered
> any kind of misbehaviour.
>
> last_active[] does not need any reset, I believe.
>
>  hw/intc/arm_gic_common.c | 21 ++++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)

I'd like to get this in before hardfreeze, ideally, so if
anybody has time to review it on Monday that would be great.

thanks
-- PMM
diff mbox

Patch

diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c
index 044ad66..a64d071 100644
--- a/hw/intc/arm_gic_common.c
+++ b/hw/intc/arm_gic_common.c
@@ -123,7 +123,7 @@  static void arm_gic_common_realize(DeviceState *dev, Error **errp)
 static void arm_gic_common_reset(DeviceState *dev)
 {
     GICState *s = ARM_GIC_COMMON(dev);
-    int i;
+    int i, j;
     memset(s->irq_state, 0, GIC_MAXIRQ * sizeof(gic_irq_state));
     for (i = 0 ; i < s->num_cpu; i++) {
         if (s->revision == REV_11MPCORE) {
@@ -135,15 +135,30 @@  static void arm_gic_common_reset(DeviceState *dev)
         s->running_irq[i] = 1023;
         s->running_priority[i] = 0x100;
         s->cpu_ctlr[i] = 0;
+        s->bpr[i] = GIC_MIN_BPR;
+        s->abpr[i] = GIC_MIN_ABPR;
+        for (j = 0; j < GIC_INTERNAL; j++) {
+            s->priority1[j][i] = 0;
+        }
+        for (j = 0; j < GIC_NR_SGIS; j++) {
+            s->sgi_pending[j][i] = 0;
+        }
     }
     for (i = 0; i < GIC_NR_SGIS; i++) {
         GIC_SET_ENABLED(i, ALL_CPU_MASK);
         GIC_SET_EDGE_TRIGGER(i);
     }
-    if (s->num_cpu == 1) {
+
+    for (i = 0; i < ARRAY_SIZE(s->priority2); i++) {
+        s->priority2[i] = 0;
+    }
+
+    for (i = 0; i < GIC_MAXIRQ; i++) {
         /* For uniprocessor GICs all interrupts always target the sole CPU */
-        for (i = 0; i < GIC_MAXIRQ; i++) {
+        if (s->num_cpu == 1) {
             s->irq_target[i] = 1;
+        } else {
+            s->irq_target[i] = 0;
         }
     }
     s->ctlr = 0;