hw/intc/arm_gic: Make ICDDCR/GICD_CTLR banked

ICDDCR/GICD_CTLR is banked if the GIC has the security extensions,
and the S (or only) copy has separate enable bits for Group0 and
Group1 enable if the GIC implements interrupt groups.

EnableGroup0 (Bit [1]) in GICv1 is architecturally IMPDEF. Since this
bit (Enable Non-secure) is present in the integrated GIC of the Cortex-A9
MPCore, we support this bit in our GICv1 implementation too.

Signed-off-by: Fabian Aggeler <aggelerf@ethz.ch>
Signed-off-by: Greg Bellows <greg.bellows@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1430502643-25909-7-git-send-email-peter.maydell@linaro.org
Message-id: 1429113742-8371-8-git-send-email-greg.bellows@linaro.org
[PMM: rewritten to store the state in a single s->ctlr uint32,
 with the NS register handled as an alias of bit 1 in that value;
 added vmstate version bump]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 38 insertions, 15 deletions

diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
index 1aa45209ce..4f13ff2c90 100644
--- a/hw/intc/arm_gic.c
+++ b/hw/intc/arm_gic.c
@@ -67,7 +67,8 @@ void gic_update(GICState *s)
     for (cpu = 0; cpu < NUM_CPU(s); cpu++) {
         cm = 1 << cpu;
         s->current_pending[cpu] = 1023;
-        if (!s->enabled || !s->cpu_enabled[cpu]) {
+        if (!(s->ctlr & (GICD_CTLR_EN_GRP0 | GICD_CTLR_EN_GRP1))
+            || !s->cpu_enabled[cpu]) {
             qemu_irq_lower(s->parent_irq[cpu]);
             return;
         }
@@ -303,8 +304,16 @@ static uint32_t gic_dist_readb(void *opaque, hwaddr offset, MemTxAttrs attrs)
     cpu = gic_get_current_cpu(s);
     cm = 1 << cpu;
     if (offset < 0x100) {
-        if (offset == 0)
-            return s->enabled;
+        if (offset == 0) {      /* GICD_CTLR */
+            if (s->security_extn && !attrs.secure) {
+                /* The NS bank of this register is just an alias of the
+                 * EnableGrp1 bit in the S bank version.
+                 */
+                return extract32(s->ctlr, 1, 1);
+            } else {
+                return s->ctlr;
+            }
+        }
         if (offset == 4)
             /* Interrupt Controller Type Register */
             return ((s->num_irq / 32) - 1)
@@ -475,8 +484,17 @@ static void gic_dist_writeb(void *opaque, hwaddr offset,
     cpu = gic_get_current_cpu(s);
     if (offset < 0x100) {
         if (offset == 0) {
-            s->enabled = (value & 1);
-            DPRINTF("Distribution %sabled\n", s->enabled ? "En" : "Dis");
+            if (s->security_extn && !attrs.secure) {
+                /* NS version is just an alias of the S version's bit 1 */
+                s->ctlr = deposit32(s->ctlr, 1, 1, value);
+            } else if (gic_has_groups(s)) {
+                s->ctlr = value & (GICD_CTLR_EN_GRP0 | GICD_CTLR_EN_GRP1);
+            } else {
+                s->ctlr = value & GICD_CTLR_EN_GRP0;
+            }
+            DPRINTF("Distributor: Group0 %sabled; Group 1 %sabled\n",
+                    s->ctlr & GICD_CTLR_EN_GRP0 ? "En" : "Dis",
+                    s->ctlr & GICD_CTLR_EN_GRP1 ? "En" : "Dis");
         } else if (offset < 4) {
             /* ignored.  */
         } else if (offset >= 0x80) {
diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c
index b5a85e5673..bef76fc474 100644
--- a/hw/intc/arm_gic_common.c
+++ b/hw/intc/arm_gic_common.c
@@ -59,12 +59,12 @@ static const VMStateDescription vmstate_gic_irq_state = {
 
 static const VMStateDescription vmstate_gic = {
     .name = "arm_gic",
-    .version_id = 8,
-    .minimum_version_id = 8,
+    .version_id = 9,
+    .minimum_version_id = 9,
     .pre_save = gic_pre_save,
     .post_load = gic_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_BOOL(enabled, GICState),
+        VMSTATE_UINT32(ctlr, GICState),
         VMSTATE_BOOL_ARRAY(cpu_enabled, GICState, GIC_NCPU),
         VMSTATE_STRUCT_ARRAY(irq_state, GICState, GIC_MAXIRQ, 1,
                              vmstate_gic_irq_state, gic_irq_state),
@@ -146,7 +146,7 @@ static void arm_gic_common_reset(DeviceState *dev)
             s->irq_target[i] = 1;
         }
     }
-    s->enabled = false;
+    s->ctlr = 0;
 }
 
 static Property arm_gic_common_properties[] = {
diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c
index 3591ca7d5d..4260fd8f04 100644
--- a/hw/intc/arm_gic_kvm.c
+++ b/hw/intc/arm_gic_kvm.c
@@ -353,8 +353,8 @@ static void kvm_arm_gic_put(GICState *s)
      * Distributor State
      */
 
-    /* s->enabled -> GICD_CTLR */
-    reg = s->enabled;
+    /* s->ctlr -> GICD_CTLR */
+    reg = s->ctlr;
     kvm_gicd_access(s, 0x0, 0, &reg, true);
 
     /* Sanity checking on GICD_TYPER and s->num_irq, s->num_cpu */
@@ -453,9 +453,9 @@ static void kvm_arm_gic_get(GICState *s)
      * Distributor State
      */
 
-    /* GICD_CTLR -> s->enabled */
+    /* GICD_CTLR -> s->ctlr */
     kvm_gicd_access(s, 0x0, 0, &reg, false);
-    s->enabled = reg & 1;
+    s->ctlr = reg;
 
     /* Sanity checking on GICD_TYPER -> s->num_irq, s->num_cpu */
     kvm_gicd_access(s, 0x4, 0, &reg, false);
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index ca19157c1e..16f0dca2d4 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -477,7 +477,7 @@ static void armv7m_nvic_reset(DeviceState *dev)
     s->gic.cpu_enabled[0] = true;
     s->gic.priority_mask[0] = 0x100;
     /* The NVIC as a whole is always enabled. */
-    s->gic.enabled = true;
+    s->gic.ctlr = 1;
     systick_reset(s);
 }
 
diff --git a/hw/intc/gic_internal.h b/hw/intc/gic_internal.h
index e8cf773e73..3b4b3fbc0e 100644
--- a/hw/intc/gic_internal.h
+++ b/hw/intc/gic_internal.h
@@ -54,6 +54,8 @@
 #define GIC_SET_GROUP(irq, cm) (s->irq_state[irq].group |= (cm))
 #define GIC_TEST_GROUP(irq, cm) ((s->irq_state[irq].group & (cm)) != 0)
 
+#define GICD_CTLR_EN_GRP0 (1U << 0)
+#define GICD_CTLR_EN_GRP1 (1U << 1)
 
 /* The special cases for the revision property: */
 #define REV_11MPCORE 0
diff --git a/include/hw/intc/arm_gic_common.h b/include/hw/intc/arm_gic_common.h
index b78981ed58..d5d38772c2 100644
--- a/include/hw/intc/arm_gic_common.h
+++ b/include/hw/intc/arm_gic_common.h
@@ -52,7 +52,10 @@ typedef struct GICState {
 
     qemu_irq parent_irq[GIC_NCPU];
     qemu_irq parent_fiq[GIC_NCPU];
-    bool enabled;
+    /* GICD_CTLR; for a GIC with the security extensions the NS banked version
+     * of this register is just an alias of bit 1 of the S banked version.
+     */
+    uint32_t ctlr;
     bool cpu_enabled[GIC_NCPU];
 
     gic_irq_state irq_state[GIC_MAXIRQ];