qemu

arm_gicv3.c (13335B)

---

 /*
  * ARM Generic Interrupt Controller v3 (emulation)
  *
  * Copyright (c) 2015 Huawei.
  * Copyright (c) 2016 Linaro Limited
  * Written by Shlomo Pongratz, Peter Maydell
  *
  * This code is licensed under the GPL, version 2 or (at your option)
  * any later version.
  */
 
 /* This file contains implementation code for an interrupt controller
  * which implements the GICv3 architecture. Specifically this is where
  * the device class itself and the functions for handling interrupts
  * coming in and going out live.
  */
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qemu/module.h"
 #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
      *  + its ACTIVE bit is not set (otherwise it would be Active+Pending)
      * 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);
     uint32_t active = *gic_bmp_ptr32(s->active, irq);
 
     pend = pending | (~edge_trigger & level);
     pend &= enable;
     pend &= ~active;
 
     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
      *  + its ACTIVE bit is not set (otherwise it would be Active+Pending)
      * 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;
     pend &= ~cs->gicr_iactiver0;
 
     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 ((cs->gicr_ctlr & GICR_CTLR_ENABLE_LPIS) && cs->gic->lpi_enable &&
         (cs->gic->gicd_ctlr & GICD_CTLR_EN_GRP1NS) &&
         (cs->hpplpi.prio != 0xff)) {
         if (irqbetter(cs, cs->hpplpi.irq, cs->hpplpi.prio)) {
             cs->hppi.irq = cs->hpplpi.irq;
             cs->hppi.prio = cs->hpplpi.prio;
             cs->hppi.grp = cs->hpplpi.grp;
             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).
      */
     if (!seenbetter && cs->hppi.prio != 0xff &&
         (cs->hppi.irq < GIC_INTERNAL ||
          cs->hppi.irq >= GICV3_LPI_INTID_START)) {
         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)
 {
     /* Meaning of the 'irq' parameter:
      *  [0..N-1] : external interrupts
      *  [N..N+31] : PPI (internal) interrupts for CPU 0
      *  [N+32..N+63] : PPI (internal interrupts for CPU 1
      *  ...
      */
     GICv3State *s = opaque;
 
     if (irq < (s->num_irq - GIC_INTERNAL)) {
         /* external interrupt (SPI) */
         gicv3_dist_set_irq(s, irq + GIC_INTERNAL, level);
     } else {
         /* per-cpu interrupt (PPI) */
         int cpu;
 
         irq -= (s->num_irq - GIC_INTERNAL);
         cpu = irq / GIC_INTERNAL;
         irq %= GIC_INTERNAL;
         assert(cpu < s->num_cpu);
         /* Raising SGIs via this function would be a bug in how the board
          * model wires up interrupts.
          */
         assert(irq >= GIC_NR_SGIS);
         gicv3_redist_set_irq(&s->cpu[cpu], irq, level);
     }
 }
 
 static void arm_gicv3_post_load(GICv3State *s)
 {
     int i;
     /* Recalculate our cached idea of the current highest priority
      * pending interrupt, but don't set IRQ or FIQ lines.
      */
     for (i = 0; i < s->num_cpu; i++) {
         gicv3_redist_update_lpi_only(&s->cpu[i]);
     }
     gicv3_full_update_noirqset(s);
     /* Repopulate the cache of GICv3CPUState pointers for target CPUs */
     gicv3_cache_all_target_cpustates(s);
 }
 
 static const MemoryRegionOps gic_ops[] = {
     {
         .read_with_attrs = gicv3_dist_read,
         .write_with_attrs = gicv3_dist_write,
         .endianness = DEVICE_NATIVE_ENDIAN,
         .valid.min_access_size = 1,
         .valid.max_access_size = 8,
         .impl.min_access_size = 1,
         .impl.max_access_size = 8,
     },
     {
         .read_with_attrs = gicv3_redist_read,
         .write_with_attrs = gicv3_redist_write,
         .endianness = DEVICE_NATIVE_ENDIAN,
         .valid.min_access_size = 1,
         .valid.max_access_size = 8,
         .impl.min_access_size = 1,
         .impl.max_access_size = 8,
     }
 };
 
 static void arm_gic_realize(DeviceState *dev, Error **errp)
 {
     /* Device instance realize function for the GIC sysbus device */
     GICv3State *s = ARM_GICV3(dev);
     ARMGICv3Class *agc = ARM_GICV3_GET_CLASS(s);
     Error *local_err = NULL;
 
     agc->parent_realize(dev, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }
 
     gicv3_init_irqs_and_mmio(s, gicv3_set_irq, gic_ops);
 
     gicv3_init_cpuif(s);
 }
 
 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;
     device_class_set_parent_realize(dc, arm_gic_realize, &agc->parent_realize);
 }
 
 static const TypeInfo arm_gicv3_info = {
     .name = TYPE_ARM_GICV3,
     .parent = TYPE_ARM_GICV3_COMMON,
     .instance_size = sizeof(GICv3State),
     .class_init = arm_gicv3_class_init,
     .class_size = sizeof(ARMGICv3Class),
 };
 
 static void arm_gicv3_register_types(void)
 {
     type_register_static(&arm_gicv3_info);
 }
 
 type_init(arm_gicv3_register_types)