[Qemu-devel] [PATCH v2 10/16] hw/intc/arm_gic: Implement Non-secure view of RPR

[Greg Bellows <greg.bellows@linaro.org>]

From: Fabian Aggeler <aggelerf@ethz.ch>

For GICs with Security Extensions Non-secure reads have a restricted
view on the current running priority.

Signed-off-by: Fabian Aggeler <aggelerf@ethz.ch>
---
 hw/intc/arm_gic.c      | 17 ++++++++++++++++-
 hw/intc/gic_internal.h |  1 +
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
index 3761d12..9b021d7 100644
--- a/hw/intc/arm_gic.c
+++ b/hw/intc/arm_gic.c
@@ -314,6 +314,21 @@ void gic_set_cpu_control(GICState *s, int cpu, uint32_t value)
     }
 }
 
+uint8_t gic_get_running_priority(GICState *s, int cpu)
+{
+    if (s->security_extn && ns_access()) {
+        if (s->running_priority[cpu] & 0x80) {
+            /* Running priority in upper half, return Non-secure view */
+            return s->running_priority[cpu] << 1;
+        } else {
+            /* Running priority in lower half, RAZ */
+            return 0;
+        }
+    } else {
+        return s->running_priority[cpu];
+    }
+}
+
 void gic_complete_irq(GICState *s, int cpu, int irq)
 {
     int update = 0;
@@ -849,7 +864,7 @@ static uint32_t gic_cpu_read(GICState *s, int cpu, int offset)
     case 0x0c: /* Acknowledge */
         return gic_acknowledge_irq(s, cpu);
     case 0x14: /* Running Priority */
-        return s->running_priority[cpu];
+        return gic_get_running_priority(s, cpu);
     case 0x18: /* Highest Pending Interrupt */
         return s->current_pending[cpu];
     case 0x1c: /* Aliased Binary Point */
diff --git a/hw/intc/gic_internal.h b/hw/intc/gic_internal.h
index e360de6..821ce16 100644
--- a/hw/intc/gic_internal.h
+++ b/hw/intc/gic_internal.h
@@ -78,6 +78,7 @@ void gic_init_irqs_and_distributor(GICState *s);
 void gic_set_priority(GICState *s, int cpu, int irq, uint8_t val);
 uint32_t gic_get_cpu_control(GICState *s, int cpu);
 void gic_set_cpu_control(GICState *s, int cpu, uint32_t value);
+uint8_t gic_get_running_priority(GICState *s, int cpu);
 
 
 static inline bool gic_test_pending(GICState *s, int irq, int cm)
-- 
1.8.3.2