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openpic: fix CTPR and de-assertion of interrupts 

Properly implement level-triggered interrupts by withdrawing an
interrupt from the raised queue if the interrupt source de-asserts.
Also withdraw from the raised queue if the interrupt becomes masked.

When CTPR is written, check whether we need to raise or lower the
interrupt output.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Scott Wood 2013-01-03 13:25:40 +00:00 committed by Alexander Graf
parent a898a8fc96
commit 9f1d4b1d69
1 changed files with 124 additions and 59 deletions
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183
hw/openpic.c
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@ -213,6 +213,9 @@ typedef struct IRQDest {
IRQQueue raised;
IRQQueue servicing;
qemu_irq *irqs;
/* Count of IRQ sources asserting on non-INT outputs */
uint32_t outputs_active[OPENPIC_OUTPUT_NB];
} IRQDest;
typedef struct OpenPICState {
@ -308,7 +311,8 @@ static int IRQ_get_next(OpenPICState *opp, IRQQueue *q)
return q->next;
}
static void IRQ_local_pipe(OpenPICState *opp, int n_CPU, int n_IRQ)
static void IRQ_local_pipe(OpenPICState *opp, int n_CPU, int n_IRQ,
bool active, bool was_active)
{
IRQDest *dst;
IRQSource *src;
@ -317,79 +321,113 @@ static void IRQ_local_pipe(OpenPICState *opp, int n_CPU, int n_IRQ)
dst = &opp->dst[n_CPU];
src = &opp->src[n_IRQ];
DPRINTF("%s: IRQ %d active %d was %d\n",
__func__, n_IRQ, active, was_active);
if (src->output != OPENPIC_OUTPUT_INT) {
DPRINTF("%s: output %d irq %d active %d was %d count %d\n",
__func__, src->output, n_IRQ, active, was_active,
dst->outputs_active[src->output]);
/* On Freescale MPIC, critical interrupts ignore priority,
* IACK, EOI, etc. Before MPIC v4.1 they also ignore
* masking.
*/
src->ivpr |= IVPR_ACTIVITY_MASK;
DPRINTF("%s: Raise OpenPIC output %d cpu %d irq %d\n",
__func__, src->output, n_CPU, n_IRQ);
qemu_irq_raise(opp->dst[n_CPU].irqs[src->output]);
if (active) {
if (!was_active && dst->outputs_active[src->output]++ == 0) {
DPRINTF("%s: Raise OpenPIC output %d cpu %d irq %d\n",
__func__, src->output, n_CPU, n_IRQ);
qemu_irq_raise(dst->irqs[src->output]);
}
} else {
if (was_active && --dst->outputs_active[src->output] == 0) {
DPRINTF("%s: Lower OpenPIC output %d cpu %d irq %d\n",
__func__, src->output, n_CPU, n_IRQ);
qemu_irq_lower(dst->irqs[src->output]);
}
}
return;
}
priority = IVPR_PRIORITY(src->ivpr);
if (priority <= dst->ctpr) {
/* Too low priority */
DPRINTF("%s: IRQ %d has too low priority on CPU %d\n",
__func__, n_IRQ, n_CPU);
return;
}
if (IRQ_testbit(&dst->raised, n_IRQ)) {
/* Interrupt miss */
DPRINTF("%s: IRQ %d was missed on CPU %d\n",
__func__, n_IRQ, n_CPU);
return;
}
src->ivpr |= IVPR_ACTIVITY_MASK;
IRQ_setbit(&dst->raised, n_IRQ);
if (priority < dst->raised.priority) {
/* An higher priority IRQ is already raised */
DPRINTF("%s: IRQ %d is hidden by raised IRQ %d on CPU %d\n",
__func__, n_IRQ, dst->raised.next, n_CPU);
return;
/* Even if the interrupt doesn't have enough priority,
* it is still raised, in case ctpr is lowered later.
*/
if (active) {
IRQ_setbit(&dst->raised, n_IRQ);
} else {
IRQ_resetbit(&dst->raised, n_IRQ);
}
IRQ_check(opp, &dst->raised);
if (IRQ_get_next(opp, &dst->servicing) != -1 &&
priority <= dst->servicing.priority) {
DPRINTF("%s: IRQ %d is hidden by servicing IRQ %d on CPU %d\n",
__func__, n_IRQ, dst->servicing.next, n_CPU);
/* Already servicing a higher priority IRQ */
return;
if (active && priority <= dst->ctpr) {
DPRINTF("%s: IRQ %d priority %d too low for ctpr %d on CPU %d\n",
__func__, n_IRQ, priority, dst->ctpr, n_CPU);
active = 0;
}
if (active) {
if (IRQ_get_next(opp, &dst->servicing) >= 0 &&
priority <= dst->servicing.priority) {
DPRINTF("%s: IRQ %d is hidden by servicing IRQ %d on CPU %d\n",
__func__, n_IRQ, dst->servicing.next, n_CPU);
} else {
DPRINTF("%s: Raise OpenPIC INT output cpu %d irq %d/%d\n",
__func__, n_CPU, n_IRQ, dst->raised.next);
qemu_irq_raise(opp->dst[n_CPU].irqs[OPENPIC_OUTPUT_INT]);
}
} else {
IRQ_get_next(opp, &dst->servicing);
if (dst->raised.priority > dst->ctpr &&
dst->raised.priority > dst->servicing.priority) {
DPRINTF("%s: IRQ %d inactive, IRQ %d prio %d above %d/%d, CPU %d\n",
__func__, n_IRQ, dst->raised.next, dst->raised.priority,
dst->ctpr, dst->servicing.priority, n_CPU);
/* IRQ line stays asserted */
} else {
DPRINTF("%s: IRQ %d inactive, current prio %d/%d, CPU %d\n",
__func__, n_IRQ, dst->ctpr, dst->servicing.priority, n_CPU);
qemu_irq_lower(opp->dst[n_CPU].irqs[OPENPIC_OUTPUT_INT]);
}
}
DPRINTF("Raise OpenPIC INT output cpu %d irq %d\n", n_CPU, n_IRQ);
qemu_irq_raise(opp->dst[n_CPU].irqs[OPENPIC_OUTPUT_INT]);
}
/* update pic state because registers for n_IRQ have changed value */
static void openpic_update_irq(OpenPICState *opp, int n_IRQ)
{
IRQSource *src;
bool active, was_active;
int i;
src = &opp->src[n_IRQ];
active = src->pending;
if (!src->pending) {
/* no irq pending */
DPRINTF("%s: IRQ %d is not pending\n", __func__, n_IRQ);
return;
}
if ((src->ivpr & IVPR_MASK_MASK) && !src->nomask) {
/* Interrupt source is disabled */
DPRINTF("%s: IRQ %d is disabled\n", __func__, n_IRQ);
active = false;
}
was_active = !!(src->ivpr & IVPR_ACTIVITY_MASK);
/*
* We don't have a similar check for already-active because
* ctpr may have changed and we need to withdraw the interrupt.
*/
if (!active && !was_active) {
DPRINTF("%s: IRQ %d is already inactive\n", __func__, n_IRQ);
return;
}
if (IVPR_PRIORITY(src->ivpr) == 0) {
/* Priority set to zero */
DPRINTF("%s: IRQ %d has 0 priority\n", __func__, n_IRQ);
return;
}
if (src->ivpr & IVPR_ACTIVITY_MASK) {
/* IRQ already active */
DPRINTF("%s: IRQ %d is already active\n", __func__, n_IRQ);
return;
if (active) {
src->ivpr |= IVPR_ACTIVITY_MASK;
} else {
src->ivpr &= ~IVPR_ACTIVITY_MASK;
}
if (src->idr == 0) {
/* No target */
DPRINTF("%s: IRQ %d has no target\n", __func__, n_IRQ);
@ -398,12 +436,12 @@ static void openpic_update_irq(OpenPICState *opp, int n_IRQ)
if (src->idr == (1 << src->last_cpu)) {
/* Only one CPU is allowed to receive this IRQ */
IRQ_local_pipe(opp, src->last_cpu, n_IRQ);
IRQ_local_pipe(opp, src->last_cpu, n_IRQ, active, was_active);
} else if (!(src->ivpr & IVPR_MODE_MASK)) {
/* Directed delivery mode */
for (i = 0; i < opp->nb_cpus; i++) {
if (src->destmask & (1 << i)) {
IRQ_local_pipe(opp, i, n_IRQ);
IRQ_local_pipe(opp, i, n_IRQ, active, was_active);
}
}
} else {
@ -413,7 +451,7 @@ static void openpic_update_irq(OpenPICState *opp, int n_IRQ)
i = 0;
}
if (src->destmask & (1 << i)) {
IRQ_local_pipe(opp, i, n_IRQ);
IRQ_local_pipe(opp, i, n_IRQ, active, was_active);
src->last_cpu = i;
break;
}
@ -437,16 +475,25 @@ static void openpic_set_irq(void *opaque, int n_IRQ, int level)
if (src->level) {
/* level-sensitive irq */
src->pending = level;
if (!level) {
src->ivpr &= ~IVPR_ACTIVITY_MASK;
}
openpic_update_irq(opp, n_IRQ);
} else {
/* edge-sensitive irq */
if (level) {
src->pending = 1;
openpic_update_irq(opp, n_IRQ);
}
if (src->output != OPENPIC_OUTPUT_INT) {
/* Edge-triggered interrupts shouldn't be used
* with non-INT delivery, but just in case,
* try to make it do something sane rather than
* cause an interrupt storm. This is close to
* what you'd probably see happen in real hardware.
*/
src->pending = 0;
openpic_update_irq(opp, n_IRQ);
}
}
openpic_update_irq(opp, n_IRQ);
}
static void openpic_reset(DeviceState *d)
@ -934,6 +981,21 @@ static void openpic_cpu_write_internal(void *opaque, hwaddr addr,
break;
case 0x80: /* CTPR */
dst->ctpr = val & 0x0000000F;
DPRINTF("%s: set CPU %d ctpr to %d, raised %d servicing %d\n",
__func__, idx, dst->ctpr, dst->raised.priority,
dst->servicing.priority);
if (dst->raised.priority <= dst->ctpr) {
DPRINTF("%s: Lower OpenPIC INT output cpu %d due to ctpr\n",
__func__, idx);
qemu_irq_lower(dst->irqs[OPENPIC_OUTPUT_INT]);
} else if (dst->raised.priority > dst->servicing.priority) {
DPRINTF("%s: Raise OpenPIC INT output cpu %d irq %d\n",
__func__, idx, dst->raised.next);
qemu_irq_raise(dst->irqs[OPENPIC_OUTPUT_INT]);
}
break;
case 0x90: /* WHOAMI */
/* Read-only register */
@ -995,22 +1057,21 @@ static uint32_t openpic_iack(OpenPICState *opp, IRQDest *dst, int cpu)
src = &opp->src[irq];
if (!(src->ivpr & IVPR_ACTIVITY_MASK) ||
!(IVPR_PRIORITY(src->ivpr) > dst->ctpr)) {
/* - Spurious level-sensitive IRQ
* - Priorities has been changed
* and the pending IRQ isn't allowed anymore
*/
src->ivpr &= ~IVPR_ACTIVITY_MASK;
fprintf(stderr, "%s: bad raised IRQ %d ctpr %d ivpr 0x%08x\n",
__func__, irq, dst->ctpr, src->ivpr);
openpic_update_irq(opp, irq);
retval = opp->spve;
} else {
/* IRQ enter servicing state */
IRQ_setbit(&dst->servicing, irq);
retval = IVPR_VECTOR(opp, src->ivpr);
}
IRQ_resetbit(&dst->raised, irq);
if (!src->level) {
/* edge-sensitive IRQ */
src->ivpr &= ~IVPR_ACTIVITY_MASK;
src->pending = 0;
IRQ_resetbit(&dst->raised, irq);
}
if ((irq >= opp->irq_ipi0) && (irq < (opp->irq_ipi0 + MAX_IPI))) {
@ -1208,6 +1269,8 @@ static void openpic_save(QEMUFile* f, void *opaque)
qemu_put_sbe32s(f, &opp->dst[i].ctpr);
openpic_save_IRQ_queue(f, &opp->dst[i].raised);
openpic_save_IRQ_queue(f, &opp->dst[i].servicing);
qemu_put_buffer(f, (uint8_t *)&opp->dst[i].outputs_active,
sizeof(opp->dst[i].outputs_active));
}
for (i = 0; i < MAX_TMR; i++) {
@ -1264,6 +1327,8 @@ static int openpic_load(QEMUFile* f, void *opaque, int version_id)
qemu_get_sbe32s(f, &opp->dst[i].ctpr);
openpic_load_IRQ_queue(f, &opp->dst[i].raised);
openpic_load_IRQ_queue(f, &opp->dst[i].servicing);
qemu_get_buffer(f, (uint8_t *)&opp->dst[i].outputs_active,
sizeof(opp->dst[i].outputs_active));
}
for (i = 0; i < MAX_TMR; i++) {