diff options
| -rw-r--r-- | hw/intc/armv7m_nvic.c | 53 | ||||
| -rw-r--r-- | target/arm/helper.c | 2 |
2 files changed, 53 insertions, 2 deletions
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 6a03e2c..479acfc 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -352,6 +352,59 @@ void armv7m_nvic_set_pending(void *opaque, int irq) vec = &s->vectors[irq]; trace_nvic_set_pending(irq, vec->enabled, vec->prio); + + + if (irq >= ARMV7M_EXCP_HARD && irq < ARMV7M_EXCP_PENDSV) { + /* If a synchronous exception is pending then it may be + * escalated to HardFault if: + * * it is equal or lower priority to current execution + * * it is disabled + * (ie we need to take it immediately but we can't do so). + * Asynchronous exceptions (and interrupts) simply remain pending. + * + * For QEMU, we don't have any imprecise (asynchronous) faults, + * so we can assume that PREFETCH_ABORT and DATA_ABORT are always + * synchronous. + * Debug exceptions are awkward because only Debug exceptions + * resulting from the BKPT instruction should be escalated, + * but we don't currently implement any Debug exceptions other + * than those that result from BKPT, so we treat all debug exceptions + * as needing escalation. + * + * This all means we can identify whether to escalate based only on + * the exception number and don't (yet) need the caller to explicitly + * tell us whether this exception is synchronous or not. + */ + int running = nvic_exec_prio(s); + bool escalate = false; + + if (vec->prio >= running) { + trace_nvic_escalate_prio(irq, vec->prio, running); + escalate = true; + } else if (!vec->enabled) { + trace_nvic_escalate_disabled(irq); + escalate = true; + } + + if (escalate) { + if (running < 0) { + /* We want to escalate to HardFault but we can't take a + * synchronous HardFault at this point either. This is a + * Lockup condition due to a guest bug. We don't model + * Lockup, so report via cpu_abort() instead. + */ + cpu_abort(&s->cpu->parent_obj, + "Lockup: can't escalate %d to HardFault " + "(current priority %d)\n", irq, running); + } + + /* We can do the escalation, so we take HardFault instead */ + irq = ARMV7M_EXCP_HARD; + vec = &s->vectors[irq]; + s->cpu->env.v7m.hfsr |= R_V7M_HFSR_FORCED_MASK; + } + } + if (!vec->pending) { vec->pending = 1; nvic_irq_update(s); diff --git a/target/arm/helper.c b/target/arm/helper.c index bcedb4a..2fc6802 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6106,8 +6106,6 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) /* For exceptions we just mark as pending on the NVIC, and let that handle it. */ - /* TODO: Need to escalate if the current priority is higher than the - one we're raising. */ switch (cs->exception_index) { case EXCP_UDEF: armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE); |