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-rw-r--r--hw/intc/arm_gic.c103
-rw-r--r--hw/intc/arm_gic_common.c7
-rw-r--r--include/hw/intc/arm_gic_common.h10
3 files changed, 76 insertions, 44 deletions
diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
index 34f781f189..9daa8cd44f 100644
--- a/hw/intc/arm_gic.c
+++ b/hw/intc/arm_gic.c
@@ -245,15 +245,72 @@ static int gic_get_group_priority(GICState *s, int cpu, int irq)
return GIC_GET_PRIORITY(irq, cpu) & mask;
}
-static void gic_set_running_irq(GICState *s, int cpu, int irq)
+static void gic_activate_irq(GICState *s, int cpu, int irq)
{
- s->running_irq[cpu] = irq;
- if (irq == 1023) {
- s->running_priority[cpu] = 0x100;
+ /* Set the appropriate Active Priority Register bit for this IRQ,
+ * and update the running priority.
+ */
+ int prio = gic_get_group_priority(s, cpu, irq);
+ int preemption_level = prio >> (GIC_MIN_BPR + 1);
+ int regno = preemption_level / 32;
+ int bitno = preemption_level % 32;
+
+ if (gic_has_groups(s) && GIC_TEST_GROUP(irq, (1 << cpu))) {
+ s->nsapr[regno][cpu] &= (1 << bitno);
} else {
- s->running_priority[cpu] = gic_get_group_priority(s, cpu, irq);
+ s->apr[regno][cpu] &= (1 << bitno);
}
- gic_update(s);
+
+ s->running_priority[cpu] = prio;
+}
+
+static int gic_get_prio_from_apr_bits(GICState *s, int cpu)
+{
+ /* Recalculate the current running priority for this CPU based
+ * on the set bits in the Active Priority Registers.
+ */
+ int i;
+ for (i = 0; i < GIC_NR_APRS; i++) {
+ uint32_t apr = s->apr[i][cpu] | s->nsapr[i][cpu];
+ if (!apr) {
+ continue;
+ }
+ return (i * 32 + ctz32(apr)) << (GIC_MIN_BPR + 1);
+ }
+ return 0x100;
+}
+
+static void gic_drop_prio(GICState *s, int cpu, int group)
+{
+ /* Drop the priority of the currently active interrupt in the
+ * specified group.
+ *
+ * Note that we can guarantee (because of the requirement to nest
+ * GICC_IAR reads [which activate an interrupt and raise priority]
+ * with GICC_EOIR writes [which drop the priority for the interrupt])
+ * that the interrupt we're being called for is the highest priority
+ * active interrupt, meaning that it has the lowest set bit in the
+ * APR registers.
+ *
+ * If the guest does not honour the ordering constraints then the
+ * behaviour of the GIC is UNPREDICTABLE, which for us means that
+ * the values of the APR registers might become incorrect and the
+ * running priority will be wrong, so interrupts that should preempt
+ * might not do so, and interrupts that should not preempt might do so.
+ */
+ int i;
+
+ for (i = 0; i < GIC_NR_APRS; i++) {
+ uint32_t *papr = group ? &s->nsapr[i][cpu] : &s->apr[i][cpu];
+ if (!*papr) {
+ continue;
+ }
+ /* Clear lowest set bit */
+ *papr &= *papr - 1;
+ break;
+ }
+
+ s->running_priority[cpu] = gic_get_prio_from_apr_bits(s, cpu);
}
uint32_t gic_acknowledge_irq(GICState *s, int cpu, MemTxAttrs attrs)
@@ -276,7 +333,6 @@ uint32_t gic_acknowledge_irq(GICState *s, int cpu, MemTxAttrs attrs)
DPRINTF("ACK, pending interrupt (%d) has insufficient priority\n", irq);
return 1023;
}
- s->last_active[irq][cpu] = s->running_irq[cpu];
if (s->revision == REV_11MPCORE || s->revision == REV_NVIC) {
/* Clear pending flags for both level and edge triggered interrupts.
@@ -307,7 +363,8 @@ uint32_t gic_acknowledge_irq(GICState *s, int cpu, MemTxAttrs attrs)
}
}
- gic_set_running_irq(s, cpu, irq);
+ gic_activate_irq(s, cpu, irq);
+ gic_update(s);
DPRINTF("ACK %d\n", irq);
return ret;
}
@@ -437,8 +494,9 @@ static uint8_t gic_get_running_priority(GICState *s, int cpu, MemTxAttrs attrs)
void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs)
{
- int update = 0;
int cm = 1 << cpu;
+ int group;
+
DPRINTF("EOI %d\n", irq);
if (irq >= s->num_irq) {
/* This handles two cases:
@@ -451,8 +509,9 @@ void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs)
*/
return;
}
- if (s->running_irq[cpu] == 1023)
+ if (s->running_priority[cpu] == 0x100) {
return; /* No active IRQ. */
+ }
if (s->revision == REV_11MPCORE || s->revision == REV_NVIC) {
/* Mark level triggered interrupts as pending if they are still
@@ -461,11 +520,12 @@ void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs)
&& GIC_TEST_LEVEL(irq, cm) && (GIC_TARGET(irq) & cm) != 0) {
DPRINTF("Set %d pending mask %x\n", irq, cm);
GIC_SET_PENDING(irq, cm);
- update = 1;
}
}
- if (s->security_extn && !attrs.secure && !GIC_TEST_GROUP(irq, cm)) {
+ group = gic_has_groups(s) && GIC_TEST_GROUP(irq, cm);
+
+ if (s->security_extn && !attrs.secure && !group) {
DPRINTF("Non-secure EOI for Group0 interrupt %d ignored\n", irq);
return;
}
@@ -475,23 +535,8 @@ void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs)
* i.e. go ahead and complete the irq anyway.
*/
- if (irq != s->running_irq[cpu]) {
- /* Complete an IRQ that is not currently running. */
- int tmp = s->running_irq[cpu];
- while (s->last_active[tmp][cpu] != 1023) {
- if (s->last_active[tmp][cpu] == irq) {
- s->last_active[tmp][cpu] = s->last_active[irq][cpu];
- break;
- }
- tmp = s->last_active[tmp][cpu];
- }
- if (update) {
- gic_update(s);
- }
- } else {
- /* Complete the current running IRQ. */
- gic_set_running_irq(s, cpu, s->last_active[s->running_irq[cpu]][cpu]);
- }
+ gic_drop_prio(s, cpu, group);
+ gic_update(s);
}
static uint32_t gic_dist_readb(void *opaque, hwaddr offset, MemTxAttrs attrs)
diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c
index 43c103e280..aa0e7d8dc2 100644
--- a/hw/intc/arm_gic_common.c
+++ b/hw/intc/arm_gic_common.c
@@ -59,8 +59,8 @@ static const VMStateDescription vmstate_gic_irq_state = {
static const VMStateDescription vmstate_gic = {
.name = "arm_gic",
- .version_id = 11,
- .minimum_version_id = 11,
+ .version_id = 12,
+ .minimum_version_id = 12,
.pre_save = gic_pre_save,
.post_load = gic_post_load,
.fields = (VMStateField[]) {
@@ -71,10 +71,8 @@ static const VMStateDescription vmstate_gic = {
VMSTATE_UINT8_ARRAY(irq_target, GICState, GIC_MAXIRQ),
VMSTATE_UINT8_2DARRAY(priority1, GICState, GIC_INTERNAL, GIC_NCPU),
VMSTATE_UINT8_ARRAY(priority2, GICState, GIC_MAXIRQ - GIC_INTERNAL),
- VMSTATE_UINT16_2DARRAY(last_active, GICState, GIC_MAXIRQ, GIC_NCPU),
VMSTATE_UINT8_2DARRAY(sgi_pending, GICState, GIC_NR_SGIS, GIC_NCPU),
VMSTATE_UINT16_ARRAY(priority_mask, GICState, GIC_NCPU),
- VMSTATE_UINT16_ARRAY(running_irq, GICState, GIC_NCPU),
VMSTATE_UINT16_ARRAY(running_priority, GICState, GIC_NCPU),
VMSTATE_UINT16_ARRAY(current_pending, GICState, GIC_NCPU),
VMSTATE_UINT8_ARRAY(bpr, GICState, GIC_NCPU),
@@ -174,7 +172,6 @@ static void arm_gic_common_reset(DeviceState *dev)
s->priority_mask[i] = 0;
}
s->current_pending[i] = 1023;
- s->running_irq[i] = 1023;
s->running_priority[i] = 0x100;
s->cpu_ctlr[i] = 0;
s->bpr[i] = GIC_MIN_BPR;
diff --git a/include/hw/intc/arm_gic_common.h b/include/hw/intc/arm_gic_common.h
index c4ec2c3dea..b9dfe05c6e 100644
--- a/include/hw/intc/arm_gic_common.h
+++ b/include/hw/intc/arm_gic_common.h
@@ -68,7 +68,6 @@ typedef struct GICState {
uint8_t irq_target[GIC_MAXIRQ];
uint8_t priority1[GIC_INTERNAL][GIC_NCPU];
uint8_t priority2[GIC_MAXIRQ - GIC_INTERNAL];
- uint16_t last_active[GIC_MAXIRQ][GIC_NCPU];
/* For each SGI on the target CPU, we store 8 bits
* indicating which source CPUs have made this SGI
* pending on the target CPU. These correspond to
@@ -78,7 +77,6 @@ typedef struct GICState {
uint8_t sgi_pending[GIC_NR_SGIS][GIC_NCPU];
uint16_t priority_mask[GIC_NCPU];
- uint16_t running_irq[GIC_NCPU];
uint16_t running_priority[GIC_NCPU];
uint16_t current_pending[GIC_NCPU];
@@ -96,14 +94,6 @@ typedef struct GICState {
* If an interrupt for preemption level X is active, then
* APRn[X mod 32] == 0b1, where n = X / 32
* otherwise the bit is clear.
- *
- * TODO: rewrite the interrupt acknowlege/complete routines to use
- * the APR registers to track the necessary information to update
- * s->running_priority[] on interrupt completion (ie completely remove
- * last_active[][] and running_irq[]). This will be necessary if we ever
- * want to support TCG<->KVM migration, or TCG guests which can
- * do power management involving powering down and restarting
- * the GIC.
*/
uint32_t apr[GIC_NR_APRS][GIC_NCPU];
uint32_t nsapr[GIC_NR_APRS][GIC_NCPU];
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-27 17:09:25 +0000