diff mbox

[RFC,v3,06/10] arm_gic: Keep track of GICD_CPENDR and GICD_SPENDR

Message ID 1384841896-19566-7-git-send-email-christoffer.dall@linaro.org
State New
Headers show

Commit Message

Christoffer Dall Nov. 19, 2013, 6:18 a.m. UTC
If software writes to the ISPENDR and sets the pending state of a
level-triggered interrupt, the falling edge of the hardware input must
not clear the pending state.  Conversely, if software writes to the
ICPENDR, the pending state of a level-triggered interrupt should only be
cleared if the hardware input is not asserted.

This requires an extra state variable to keep track of software writes.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 hw/intc/arm_gic.c                | 20 +++++++++++++++++---
 hw/intc/arm_gic_common.c         |  5 +++--
 hw/intc/gic_internal.h           |  3 +++
 include/hw/intc/arm_gic_common.h |  1 +
 4 files changed, 24 insertions(+), 5 deletions(-)
diff mbox

Patch

diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
index 5736b95..9811161 100644
--- a/hw/intc/arm_gic.c
+++ b/hw/intc/arm_gic.c
@@ -119,6 +119,12 @@  static void gic_clear_pending(GICState *s, int irq, int cm, uint8_t src)
             GIC_CLEAR_PENDING(irq, cm);
         }
     } else {
+        /* If a level-triggered interrupt has been set to pending through the
+         * GICD_SPENDR, then a falling edge does not clear the pending state.
+         */
+        if (GIC_TEST_SW_PENDING(irq, cm))
+            return;
+
         GIC_CLEAR_PENDING(irq, cm);
     }
 }
@@ -189,8 +195,9 @@  uint32_t gic_acknowledge_irq(GICState *s, int cpu)
     s->last_active[new_irq][cpu] = s->running_irq[cpu];
     /* Clear pending flags for both level and edge triggered interrupts.
        Level triggered IRQs will be reasserted once they become inactive.  */
-    gic_clear_pending(s, new_irq, GIC_TEST_MODEL(new_irq) ? ALL_CPU_MASK : cm,
-                                  GIC_SGI_SRC(new_irq, cpu));
+    cm = GIC_TEST_MODEL(new_irq) ? ALL_CPU_MASK : cm;
+    GIC_CLEAR_SW_PENDING(new_irq, cm);
+    gic_clear_pending(s, new_irq, cm, GIC_SGI_SRC(new_irq, cpu));
     gic_set_running_irq(s, cpu, new_irq);
     DPRINTF("ACK %d\n", new_irq);
     return new_irq;
@@ -454,16 +461,23 @@  static void gic_dist_writeb(void *opaque, hwaddr offset,
         for (i = 0; i < 8; i++, irq++) {
             if (irq >= GIC_NR_SGIS && value & (1 << i)) {
                 GIC_SET_PENDING(irq, GIC_TARGET(irq));
+                if (!GIC_TEST_EDGE_TRIGGER(irq)) {
+                    GIC_SET_SW_PENDING(irq, GIC_TARGET(irq));
+                }
             }
         }
     } else if (offset < 0x300) {
+        int cm = (1 << cpu);
         /* Interrupt Clear Pending.  */
         irq = (offset - 0x280) * 8 + GIC_BASE_IRQ;
         if (irq >= s->num_irq)
             goto bad_reg;
         for (i = 0; i < 8; i++, irq++) {
             if (irq >= GIC_NR_SGIS && value & (1 << i)) {
-                gic_clear_pending(s, irq, 1 << cpu, 0);
+                GIC_CLEAR_SW_PENDING(irq, cm);
+                if (GIC_TEST_EDGE_TRIGGER(irq) || !GIC_TEST_LEVEL(irq, cm)) {
+                    GIC_CLEAR_PENDING(irq, cm);
+                }
             }
         }
     } else if (offset < 0x400) {
diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c
index 41ddc9b..65e3dc8 100644
--- a/hw/intc/arm_gic_common.c
+++ b/hw/intc/arm_gic_common.c
@@ -43,11 +43,12 @@  static int gic_post_load(void *opaque, int version_id)
 
 static const VMStateDescription vmstate_gic_irq_state = {
     .name = "arm_gic_irq_state",
-    .version_id = 1,
-    .minimum_version_id = 1,
+    .version_id = 2,
+    .minimum_version_id = 2,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(enabled, gic_irq_state),
         VMSTATE_UINT8(pending, gic_irq_state),
+        VMSTATE_UINT8(sw_pending, gic_irq_state),
         VMSTATE_UINT8(active, gic_irq_state),
         VMSTATE_UINT8(level, gic_irq_state),
         VMSTATE_BOOL(model, gic_irq_state),
diff --git a/hw/intc/gic_internal.h b/hw/intc/gic_internal.h
index 5471749..b04cb50 100644
--- a/hw/intc/gic_internal.h
+++ b/hw/intc/gic_internal.h
@@ -35,6 +35,9 @@ 
 #define GIC_SET_PENDING(irq, cm) s->irq_state[irq].pending |= (cm)
 #define GIC_CLEAR_PENDING(irq, cm) s->irq_state[irq].pending &= ~(cm)
 #define GIC_TEST_PENDING(irq, cm) ((s->irq_state[irq].pending & (cm)) != 0)
+#define GIC_SET_SW_PENDING(irq, cm) (s->irq_state[irq].sw_pending |= (cm))
+#define GIC_CLEAR_SW_PENDING(irq, cm) (s->irq_state[irq].sw_pending &= ~(cm))
+#define GIC_TEST_SW_PENDING(irq, cm) ((s->irq_state[irq].sw_pending & (cm)) != 0)
 #define GIC_SET_ACTIVE(irq, cm) s->irq_state[irq].active |= (cm)
 #define GIC_CLEAR_ACTIVE(irq, cm) s->irq_state[irq].active &= ~(cm)
 #define GIC_TEST_ACTIVE(irq, cm) ((s->irq_state[irq].active & (cm)) != 0)
diff --git a/include/hw/intc/arm_gic_common.h b/include/hw/intc/arm_gic_common.h
index 120d6b2..2d6c23f 100644
--- a/include/hw/intc/arm_gic_common.h
+++ b/include/hw/intc/arm_gic_common.h
@@ -35,6 +35,7 @@  typedef struct gic_irq_state {
     /* The enable bits are only banked for per-cpu interrupts.  */
     uint8_t enabled;
     uint8_t pending;
+    uint8_t sw_pending; /* keep track of GICD_ISPENDR and GICD_ICPENDR writes */
     uint8_t active;
     uint8_t level;
     bool model; /* 0 = N:N, 1 = 1:N */