diff options
Diffstat (limited to 'hw/intc/arm_gicv3.c')
| -rw-r--r-- | hw/intc/arm_gicv3.c | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/hw/intc/arm_gicv3.c b/hw/intc/arm_gicv3.c index 96e0d2ffcc..171d58728c 100644 --- a/hw/intc/arm_gicv3.c +++ b/hw/intc/arm_gicv3.c @@ -21,6 +21,287 @@ #include "hw/intc/arm_gicv3.h" #include "gicv3_internal.h" +static bool irqbetter(GICv3CPUState *cs, int irq, uint8_t prio) +{ + /* Return true if this IRQ at this priority should take + * precedence over the current recorded highest priority + * pending interrupt for this CPU. We also return true if + * the current recorded highest priority pending interrupt + * is the same as this one (a property which the calling code + * relies on). + */ + if (prio < cs->hppi.prio) { + return true; + } + /* If multiple pending interrupts have the same priority then it is an + * IMPDEF choice which of them to signal to the CPU. We choose to + * signal the one with the lowest interrupt number. + */ + if (prio == cs->hppi.prio && irq <= cs->hppi.irq) { + return true; + } + return false; +} + +static uint32_t gicd_int_pending(GICv3State *s, int irq) +{ + /* Recalculate which distributor interrupts are actually pending + * in the group of 32 interrupts starting at irq (which should be a multiple + * of 32), and return a 32-bit integer which has a bit set for each + * interrupt that is eligible to be signaled to the CPU interface. + * + * An interrupt is pending if: + * + the PENDING latch is set OR it is level triggered and the input is 1 + * + its ENABLE bit is set + * + the GICD enable bit for its group is set + * Conveniently we can bulk-calculate this with bitwise operations. + */ + uint32_t pend, grpmask; + uint32_t pending = *gic_bmp_ptr32(s->pending, irq); + uint32_t edge_trigger = *gic_bmp_ptr32(s->edge_trigger, irq); + uint32_t level = *gic_bmp_ptr32(s->level, irq); + uint32_t group = *gic_bmp_ptr32(s->group, irq); + uint32_t grpmod = *gic_bmp_ptr32(s->grpmod, irq); + uint32_t enable = *gic_bmp_ptr32(s->enabled, irq); + + pend = pending | (~edge_trigger & level); + pend &= enable; + + if (s->gicd_ctlr & GICD_CTLR_DS) { + grpmod = 0; + } + + grpmask = 0; + if (s->gicd_ctlr & GICD_CTLR_EN_GRP1NS) { + grpmask |= group; + } + if (s->gicd_ctlr & GICD_CTLR_EN_GRP1S) { + grpmask |= (~group & grpmod); + } + if (s->gicd_ctlr & GICD_CTLR_EN_GRP0) { + grpmask |= (~group & ~grpmod); + } + pend &= grpmask; + + return pend; +} + +static uint32_t gicr_int_pending(GICv3CPUState *cs) +{ + /* Recalculate which redistributor interrupts are actually pending, + * and return a 32-bit integer which has a bit set for each interrupt + * that is eligible to be signaled to the CPU interface. + * + * An interrupt is pending if: + * + the PENDING latch is set OR it is level triggered and the input is 1 + * + its ENABLE bit is set + * + the GICD enable bit for its group is set + * Conveniently we can bulk-calculate this with bitwise operations. + */ + uint32_t pend, grpmask, grpmod; + + pend = cs->gicr_ipendr0 | (~cs->edge_trigger & cs->level); + pend &= cs->gicr_ienabler0; + + if (cs->gic->gicd_ctlr & GICD_CTLR_DS) { + grpmod = 0; + } else { + grpmod = cs->gicr_igrpmodr0; + } + + grpmask = 0; + if (cs->gic->gicd_ctlr & GICD_CTLR_EN_GRP1NS) { + grpmask |= cs->gicr_igroupr0; + } + if (cs->gic->gicd_ctlr & GICD_CTLR_EN_GRP1S) { + grpmask |= (~cs->gicr_igroupr0 & grpmod); + } + if (cs->gic->gicd_ctlr & GICD_CTLR_EN_GRP0) { + grpmask |= (~cs->gicr_igroupr0 & ~grpmod); + } + pend &= grpmask; + + return pend; +} + +/* Update the interrupt status after state in a redistributor + * or CPU interface has changed, but don't tell the CPU i/f. + */ +static void gicv3_redist_update_noirqset(GICv3CPUState *cs) +{ + /* Find the highest priority pending interrupt among the + * redistributor interrupts (SGIs and PPIs). + */ + bool seenbetter = false; + uint8_t prio; + int i; + uint32_t pend; + + /* Find out which redistributor interrupts are eligible to be + * signaled to the CPU interface. + */ + pend = gicr_int_pending(cs); + + if (pend) { + for (i = 0; i < GIC_INTERNAL; i++) { + if (!(pend & (1 << i))) { + continue; + } + prio = cs->gicr_ipriorityr[i]; + if (irqbetter(cs, i, prio)) { + cs->hppi.irq = i; + cs->hppi.prio = prio; + seenbetter = true; + } + } + } + + if (seenbetter) { + cs->hppi.grp = gicv3_irq_group(cs->gic, cs, cs->hppi.irq); + } + + /* If the best interrupt we just found would preempt whatever + * was the previous best interrupt before this update, then + * we know it's definitely the best one now. + * If we didn't find an interrupt that would preempt the previous + * best, and the previous best is outside our range (or there was no + * previous pending interrupt at all), then that is still valid, and + * we leave it as the best. + * Otherwise, we need to do a full update (because the previous best + * interrupt has reduced in priority and any other interrupt could + * now be the new best one). + */ + if (!seenbetter && cs->hppi.prio != 0xff && cs->hppi.irq < GIC_INTERNAL) { + gicv3_full_update_noirqset(cs->gic); + } +} + +/* Update the GIC status after state in a redistributor or + * CPU interface has changed, and inform the CPU i/f of + * its new highest priority pending interrupt. + */ +void gicv3_redist_update(GICv3CPUState *cs) +{ + gicv3_redist_update_noirqset(cs); + gicv3_cpuif_update(cs); +} + +/* Update the GIC status after state in the distributor has + * changed affecting @len interrupts starting at @start, + * but don't tell the CPU i/f. + */ +static void gicv3_update_noirqset(GICv3State *s, int start, int len) +{ + int i; + uint8_t prio; + uint32_t pend = 0; + + assert(start >= GIC_INTERNAL); + assert(len > 0); + + for (i = 0; i < s->num_cpu; i++) { + s->cpu[i].seenbetter = false; + } + + /* Find the highest priority pending interrupt in this range. */ + for (i = start; i < start + len; i++) { + GICv3CPUState *cs; + + if (i == start || (i & 0x1f) == 0) { + /* Calculate the next 32 bits worth of pending status */ + pend = gicd_int_pending(s, i & ~0x1f); + } + + if (!(pend & (1 << (i & 0x1f)))) { + continue; + } + cs = s->gicd_irouter_target[i]; + if (!cs) { + /* Interrupts targeting no implemented CPU should remain pending + * and not be forwarded to any CPU. + */ + continue; + } + prio = s->gicd_ipriority[i]; + if (irqbetter(cs, i, prio)) { + cs->hppi.irq = i; + cs->hppi.prio = prio; + cs->seenbetter = true; + } + } + + /* If the best interrupt we just found would preempt whatever + * was the previous best interrupt before this update, then + * we know it's definitely the best one now. + * If we didn't find an interrupt that would preempt the previous + * best, and the previous best is outside our range (or there was + * no previous pending interrupt at all), then that + * is still valid, and we leave it as the best. + * Otherwise, we need to do a full update (because the previous best + * interrupt has reduced in priority and any other interrupt could + * now be the new best one). + */ + for (i = 0; i < s->num_cpu; i++) { + GICv3CPUState *cs = &s->cpu[i]; + + if (cs->seenbetter) { + cs->hppi.grp = gicv3_irq_group(cs->gic, cs, cs->hppi.irq); + } + + if (!cs->seenbetter && cs->hppi.prio != 0xff && + cs->hppi.irq >= start && cs->hppi.irq < start + len) { + gicv3_full_update_noirqset(s); + break; + } + } +} + +void gicv3_update(GICv3State *s, int start, int len) +{ + int i; + + gicv3_update_noirqset(s, start, len); + for (i = 0; i < s->num_cpu; i++) { + gicv3_cpuif_update(&s->cpu[i]); + } +} + +void gicv3_full_update_noirqset(GICv3State *s) +{ + /* Completely recalculate the GIC status from scratch, but + * don't update any outbound IRQ lines. + */ + int i; + + for (i = 0; i < s->num_cpu; i++) { + s->cpu[i].hppi.prio = 0xff; + } + + /* Note that we can guarantee that these functions will not + * recursively call back into gicv3_full_update(), because + * at each point the "previous best" is always outside the + * range we ask them to update. + */ + gicv3_update_noirqset(s, GIC_INTERNAL, s->num_irq - GIC_INTERNAL); + + for (i = 0; i < s->num_cpu; i++) { + gicv3_redist_update_noirqset(&s->cpu[i]); + } +} + +void gicv3_full_update(GICv3State *s) +{ + /* Completely recalculate the GIC status from scratch, including + * updating outbound IRQ lines. + */ + int i; + + gicv3_full_update_noirqset(s); + for (i = 0; i < s->num_cpu; i++) { + gicv3_cpuif_update(&s->cpu[i]); + } +} + /* Process a change in an external IRQ input. */ static void gicv3_set_irq(void *opaque, int irq, int level) { @@ -33,6 +314,16 @@ static void gicv3_set_irq(void *opaque, int irq, int level) /* Do nothing for now */ } +static void arm_gicv3_post_load(GICv3State *s) +{ + /* Recalculate our cached idea of the current highest priority + * pending interrupt, but don't set IRQ or FIQ lines. + */ + gicv3_full_update_noirqset(s); + /* Repopulate the cache of GICv3CPUState pointers for target CPUs */ + gicv3_cache_all_target_cpustates(s); +} + static void arm_gic_realize(DeviceState *dev, Error **errp) { /* Device instance realize function for the GIC sysbus device */ @@ -52,8 +343,10 @@ static void arm_gic_realize(DeviceState *dev, Error **errp) static void arm_gicv3_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); + ARMGICv3CommonClass *agcc = ARM_GICV3_COMMON_CLASS(klass); ARMGICv3Class *agc = ARM_GICV3_CLASS(klass); + agcc->post_load = arm_gicv3_post_load; agc->parent_realize = dc->realize; dc->realize = arm_gic_realize; } |