diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 53b4631dac..fff6e694e6 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -655,6 +655,102 @@ void armv7m_nvic_set_pending_derived(void *opaque, int irq, bool secure) do_armv7m_nvic_set_pending(opaque, irq, secure, true); } +void armv7m_nvic_set_pending_lazyfp(void *opaque, int irq, bool secure) +{ + /* + * Pend an exception during lazy FP stacking. This differs + * from the usual exception pending because the logic for + * whether we should escalate depends on the saved context + * in the FPCCR register, not on the current state of the CPU/NVIC. + */ + NVICState *s = (NVICState *)opaque; + bool banked = exc_is_banked(irq); + VecInfo *vec; + bool targets_secure; + bool escalate = false; + /* + * We will only look at bits in fpccr if this is a banked exception + * (in which case 'secure' tells us whether it is the S or NS version). + * All the bits for the non-banked exceptions are in fpccr_s. + */ + uint32_t fpccr_s = s->cpu->env.v7m.fpccr[M_REG_S]; + uint32_t fpccr = s->cpu->env.v7m.fpccr[secure]; + + assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq); + assert(!secure || banked); + + vec = (banked && secure) ? &s->sec_vectors[irq] : &s->vectors[irq]; + + targets_secure = banked ? secure : exc_targets_secure(s, irq); + + switch (irq) { + case ARMV7M_EXCP_DEBUG: + if (!(fpccr_s & R_V7M_FPCCR_MONRDY_MASK)) { + /* Ignore DebugMonitor exception */ + return; + } + break; + case ARMV7M_EXCP_MEM: + escalate = !(fpccr & R_V7M_FPCCR_MMRDY_MASK); + break; + case ARMV7M_EXCP_USAGE: + escalate = !(fpccr & R_V7M_FPCCR_UFRDY_MASK); + break; + case ARMV7M_EXCP_BUS: + escalate = !(fpccr_s & R_V7M_FPCCR_BFRDY_MASK); + break; + case ARMV7M_EXCP_SECURE: + escalate = !(fpccr_s & R_V7M_FPCCR_SFRDY_MASK); + break; + default: + g_assert_not_reached(); + } + + if (escalate) { + /* + * Escalate to HardFault: faults that initially targeted Secure + * continue to do so, even if HF normally targets NonSecure. + */ + irq = ARMV7M_EXCP_HARD; + if (arm_feature(&s->cpu->env, ARM_FEATURE_M_SECURITY) && + (targets_secure || + !(s->cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK))) { + vec = &s->sec_vectors[irq]; + } else { + vec = &s->vectors[irq]; + } + } + + if (!vec->enabled || + nvic_exec_prio(s) <= exc_group_prio(s, vec->prio, secure)) { + if (!(fpccr_s & R_V7M_FPCCR_HFRDY_MASK)) { + /* + * We want to escalate to HardFault but the context the + * FP state belongs to prevents the exception pre-empting. + */ + cpu_abort(&s->cpu->parent_obj, + "Lockup: can't escalate to HardFault during " + "lazy FP register stacking\n"); + } + } + + if (escalate) { + s->cpu->env.v7m.hfsr |= R_V7M_HFSR_FORCED_MASK; + } + if (!vec->pending) { + vec->pending = 1; + /* + * We do not call nvic_irq_update(), because we know our caller + * is going to handle causing us to take the exception by + * raising EXCP_LAZYFP, so raising the IRQ line would be + * pointless extra work. We just need to recompute the + * priorities so that armv7m_nvic_can_take_pending_exception() + * returns the right answer. + */ + nvic_recompute_state(s); + } +} + /* Make pending IRQ active. */ void armv7m_nvic_acknowledge_irq(void *opaque) { diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 920cf36702..ed3069341d 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2008,6 +2008,18 @@ void armv7m_nvic_set_pending(void *opaque, int irq, bool secure); * a different exception). */ void armv7m_nvic_set_pending_derived(void *opaque, int irq, bool secure); +/** + * armv7m_nvic_set_pending_lazyfp: mark this lazy FP exception as pending + * @opaque: the NVIC + * @irq: the exception number to mark pending + * @secure: false for non-banked exceptions or for the nonsecure + * version of a banked exception, true for the secure version of a banked + * exception. + * + * Similar to armv7m_nvic_set_pending(), but specifically for exceptions + * generated in the course of lazy stacking of FP registers. + */ +void armv7m_nvic_set_pending_lazyfp(void *opaque, int irq, bool secure); /** * armv7m_nvic_get_pending_irq_info: return highest priority pending * exception, and whether it targets Secure state