From b5c633c5bd6993df1bf3401d94042fb8a910a92a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 30 Oct 2014 15:48:51 +0000 Subject: [PATCH] target-arm: Separate out M profile cpu_exec_interrupt handling The M profile cpu_exec_interrupt handling is fairly simple but does include an M profile specific oddity (disabling interrupts for certain PC values). A/R profile handling on the other hand is getting rapidly more complicated with the support for EL2 and EL3. Split the M profile code out into its own implementation of cpu_exec_interrupt to keep these two things out of each others' way. Signed-off-by: Peter Maydell Reviewed-by: Edgar E. Iglesias Message-id: 1414684132-23971-2-git-send-email-peter.maydell@linaro.org --- target-arm/cpu.c | 49 ++++++++++++++++++++++++++++++++++++++---------- target-arm/cpu.h | 16 ++-------------- 2 files changed, 41 insertions(+), 24 deletions(-) diff --git a/target-arm/cpu.c b/target-arm/cpu.c index e0b82a6704..5ce7350ce6 100644 --- a/target-arm/cpu.c +++ b/target-arm/cpu.c @@ -203,15 +203,6 @@ bool arm_cpu_exec_interrupt(CPUState *cs, int interrupt_request) cc->do_interrupt(cs); ret = true; } - /* ARMv7-M interrupt return works by loading a magic value - into the PC. On real hardware the load causes the - return to occur. The qemu implementation performs the - jump normally, then does the exception return when the - CPU tries to execute code at the magic address. - This will cause the magic PC value to be pushed to - the stack if an interrupt occurred at the wrong time. - We avoid this by disabling interrupts when - pc contains a magic address. */ if (interrupt_request & CPU_INTERRUPT_HARD && arm_excp_unmasked(cs, EXCP_IRQ)) { cs->exception_index = EXCP_IRQ; @@ -234,6 +225,42 @@ bool arm_cpu_exec_interrupt(CPUState *cs, int interrupt_request) return ret; } +#if !defined(CONFIG_USER_ONLY) || !defined(TARGET_AARCH64) +static bool arm_v7m_cpu_exec_interrupt(CPUState *cs, int interrupt_request) +{ + CPUClass *cc = CPU_GET_CLASS(cs); + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; + bool ret = false; + + + if (interrupt_request & CPU_INTERRUPT_FIQ + && !(env->daif & PSTATE_F)) { + cs->exception_index = EXCP_FIQ; + cc->do_interrupt(cs); + ret = true; + } + /* ARMv7-M interrupt return works by loading a magic value + * into the PC. On real hardware the load causes the + * return to occur. The qemu implementation performs the + * jump normally, then does the exception return when the + * CPU tries to execute code at the magic address. + * This will cause the magic PC value to be pushed to + * the stack if an interrupt occurred at the wrong time. + * We avoid this by disabling interrupts when + * pc contains a magic address. + */ + if (interrupt_request & CPU_INTERRUPT_HARD + && !(env->daif & PSTATE_I) + && (env->regs[15] < 0xfffffff0)) { + cs->exception_index = EXCP_IRQ; + cc->do_interrupt(cs); + ret = true; + } + return ret; +} +#endif + #ifndef CONFIG_USER_ONLY static void arm_cpu_set_irq(void *opaque, int irq, int level) { @@ -670,11 +697,13 @@ static void cortex_m3_initfn(Object *obj) static void arm_v7m_class_init(ObjectClass *oc, void *data) { -#ifndef CONFIG_USER_ONLY CPUClass *cc = CPU_CLASS(oc); +#ifndef CONFIG_USER_ONLY cc->do_interrupt = arm_v7m_cpu_do_interrupt; #endif + + cc->cpu_exec_interrupt = arm_v7m_cpu_exec_interrupt; } static const ARMCPRegInfo cortexa8_cp_reginfo[] = { diff --git a/target-arm/cpu.h b/target-arm/cpu.h index cb6ec5c59f..97eaf79696 100644 --- a/target-arm/cpu.h +++ b/target-arm/cpu.h @@ -1251,18 +1251,6 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx) bool secure = false; /* If in EL1/0, Physical IRQ routing to EL2 only happens from NS state. */ bool irq_can_hyp = !secure && cur_el < 2 && target_el == 2; - /* ARMv7-M interrupt return works by loading a magic value - * into the PC. On real hardware the load causes the - * return to occur. The qemu implementation performs the - * jump normally, then does the exception return when the - * CPU tries to execute code at the magic address. - * This will cause the magic PC value to be pushed to - * the stack if an interrupt occurred at the wrong time. - * We avoid this by disabling interrupts when - * pc contains a magic address. - */ - bool irq_unmasked = !(env->daif & PSTATE_I) - && (!IS_M(env) || env->regs[15] < 0xfffffff0); /* Don't take exceptions if they target a lower EL. */ if (cur_el > target_el) { @@ -1279,7 +1267,7 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx) if (irq_can_hyp && (env->cp15.hcr_el2 & HCR_IMO)) { return true; } - return irq_unmasked; + return !(env->daif & PSTATE_I); case EXCP_VFIQ: if (!secure && !(env->cp15.hcr_el2 & HCR_FMO)) { /* VFIQs are only taken when hypervized and non-secure. */ @@ -1291,7 +1279,7 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx) /* VIRQs are only taken when hypervized and non-secure. */ return false; } - return irq_unmasked; + return !(env->daif & PSTATE_I); default: g_assert_not_reached(); }