From f797c07507b4af66ae6817390001dbc1036591ef Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 28 Feb 2017 12:08:16 +0000 Subject: armv7m: Rename nvic_state to NVICState Rename the nvic_state struct to NVICState, to match our naming conventions. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 44 ++++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index fe5c303de9..09975f3c62 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -21,7 +21,7 @@ #include "gic_internal.h" #include "qemu/log.h" -typedef struct { +typedef struct NVICState { GICState gic; ARMCPU *cpu; struct { @@ -35,7 +35,7 @@ typedef struct { MemoryRegion container; uint32_t num_irq; qemu_irq sysresetreq; -} nvic_state; +} NVICState; #define TYPE_NVIC "armv7m_nvic" /** @@ -57,7 +57,7 @@ typedef struct NVICClass { #define NVIC_GET_CLASS(obj) \ OBJECT_GET_CLASS(NVICClass, (obj), TYPE_NVIC) #define NVIC(obj) \ - OBJECT_CHECK(nvic_state, (obj), TYPE_NVIC) + OBJECT_CHECK(NVICState, (obj), TYPE_NVIC) static const uint8_t nvic_id[] = { 0x00, 0xb0, 0x1b, 0x00, 0x0d, 0xe0, 0x05, 0xb1 @@ -74,7 +74,7 @@ static const uint8_t nvic_id[] = { int system_clock_scale; /* Conversion factor from qemu timer to SysTick frequencies. */ -static inline int64_t systick_scale(nvic_state *s) +static inline int64_t systick_scale(NVICState *s) { if (s->systick.control & SYSTICK_CLKSOURCE) return system_clock_scale; @@ -82,7 +82,7 @@ static inline int64_t systick_scale(nvic_state *s) return 1000; } -static void systick_reload(nvic_state *s, int reset) +static void systick_reload(NVICState *s, int reset) { /* The Cortex-M3 Devices Generic User Guide says that "When the * ENABLE bit is set to 1, the counter loads the RELOAD value from the @@ -101,7 +101,7 @@ static void systick_reload(nvic_state *s, int reset) static void systick_timer_tick(void * opaque) { - nvic_state *s = (nvic_state *)opaque; + NVICState *s = (NVICState *)opaque; s->systick.control |= SYSTICK_COUNTFLAG; if (s->systick.control & SYSTICK_TICKINT) { /* Trigger the interrupt. */ @@ -114,7 +114,7 @@ static void systick_timer_tick(void * opaque) } } -static void systick_reset(nvic_state *s) +static void systick_reset(NVICState *s) { s->systick.control = 0; s->systick.reload = 0; @@ -126,7 +126,7 @@ static void systick_reset(nvic_state *s) IRQ is #16. The internal GIC routines use #32 as the first IRQ. */ void armv7m_nvic_set_pending(void *opaque, int irq) { - nvic_state *s = (nvic_state *)opaque; + NVICState *s = (NVICState *)opaque; if (irq >= 16) irq += 16; gic_set_pending_private(&s->gic, 0, irq); @@ -135,7 +135,7 @@ void armv7m_nvic_set_pending(void *opaque, int irq) /* Make pending IRQ active. */ int armv7m_nvic_acknowledge_irq(void *opaque) { - nvic_state *s = (nvic_state *)opaque; + NVICState *s = (NVICState *)opaque; uint32_t irq; irq = gic_acknowledge_irq(&s->gic, 0, MEMTXATTRS_UNSPECIFIED); @@ -148,13 +148,13 @@ int armv7m_nvic_acknowledge_irq(void *opaque) void armv7m_nvic_complete_irq(void *opaque, int irq) { - nvic_state *s = (nvic_state *)opaque; + NVICState *s = (NVICState *)opaque; if (irq >= 16) irq += 16; gic_complete_irq(&s->gic, 0, irq, MEMTXATTRS_UNSPECIFIED); } -static uint32_t nvic_readl(nvic_state *s, uint32_t offset) +static uint32_t nvic_readl(NVICState *s, uint32_t offset) { ARMCPU *cpu = s->cpu; uint32_t val; @@ -294,7 +294,7 @@ static uint32_t nvic_readl(nvic_state *s, uint32_t offset) } } -static void nvic_writel(nvic_state *s, uint32_t offset, uint32_t value) +static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) { ARMCPU *cpu = s->cpu; uint32_t oldval; @@ -425,7 +425,7 @@ static void nvic_writel(nvic_state *s, uint32_t offset, uint32_t value) static uint64_t nvic_sysreg_read(void *opaque, hwaddr addr, unsigned size) { - nvic_state *s = (nvic_state *)opaque; + NVICState *s = (NVICState *)opaque; uint32_t offset = addr; int i; uint32_t val; @@ -454,7 +454,7 @@ static uint64_t nvic_sysreg_read(void *opaque, hwaddr addr, static void nvic_sysreg_write(void *opaque, hwaddr addr, uint64_t value, unsigned size) { - nvic_state *s = (nvic_state *)opaque; + NVICState *s = (NVICState *)opaque; uint32_t offset = addr; int i; @@ -486,17 +486,17 @@ static const VMStateDescription vmstate_nvic = { .version_id = 1, .minimum_version_id = 1, .fields = (VMStateField[]) { - VMSTATE_UINT32(systick.control, nvic_state), - VMSTATE_UINT32(systick.reload, nvic_state), - VMSTATE_INT64(systick.tick, nvic_state), - VMSTATE_TIMER_PTR(systick.timer, nvic_state), + VMSTATE_UINT32(systick.control, NVICState), + VMSTATE_UINT32(systick.reload, NVICState), + VMSTATE_INT64(systick.tick, NVICState), + VMSTATE_TIMER_PTR(systick.timer, NVICState), VMSTATE_END_OF_LIST() } }; static void armv7m_nvic_reset(DeviceState *dev) { - nvic_state *s = NVIC(dev); + NVICState *s = NVIC(dev); NVICClass *nc = NVIC_GET_CLASS(s); nc->parent_reset(dev); /* Common GIC reset resets to disabled; the NVIC doesn't have @@ -513,7 +513,7 @@ static void armv7m_nvic_reset(DeviceState *dev) static void armv7m_nvic_realize(DeviceState *dev, Error **errp) { - nvic_state *s = NVIC(dev); + NVICState *s = NVIC(dev); NVICClass *nc = NVIC_GET_CLASS(s); Error *local_err = NULL; @@ -569,7 +569,7 @@ static void armv7m_nvic_instance_init(Object *obj) */ GICState *s = ARM_GIC_COMMON(obj); DeviceState *dev = DEVICE(obj); - nvic_state *nvic = NVIC(obj); + NVICState *nvic = NVIC(obj); /* The ARM v7m may have anything from 0 to 496 external interrupt * IRQ lines. We default to 64. Other boards may differ and should * set the num-irq property appropriately. @@ -594,7 +594,7 @@ static const TypeInfo armv7m_nvic_info = { .name = TYPE_NVIC, .parent = TYPE_ARM_GIC_COMMON, .instance_init = armv7m_nvic_instance_init, - .instance_size = sizeof(nvic_state), + .instance_size = sizeof(NVICState), .class_init = armv7m_nvic_class_init, .class_size = sizeof(NVICClass), }; -- cgit v1.2.3-55-g7522 From 1004102a772744fbb31d8001ade0090be8b02a93 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 28 Feb 2017 12:08:16 +0000 Subject: armv7m: Implement reading and writing of PRIGROUP Add a state field for the v7M PRIGROUP register and implent reading and writing it. The current NVIC doesn't honour the values written, but the new version will. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 09975f3c62..ce22001b6c 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -24,6 +24,9 @@ typedef struct NVICState { GICState gic; ARMCPU *cpu; + + uint32_t prigroup; + struct { uint32_t control; uint32_t reload; @@ -223,7 +226,7 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset) case 0xd08: /* Vector Table Offset. */ return cpu->env.v7m.vecbase; case 0xd0c: /* Application Interrupt/Reset Control. */ - return 0xfa050000; + return 0xfa050000 | (s->prigroup << 8); case 0xd10: /* System Control. */ /* TODO: Implement SLEEPONEXIT. */ return 0; @@ -362,9 +365,7 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) if (value & 1) { qemu_log_mask(LOG_UNIMP, "AIRCR system reset unimplemented\n"); } - if (value & 0x700) { - qemu_log_mask(LOG_UNIMP, "PRIGROUP unimplemented\n"); - } + s->prigroup = extract32(value, 8, 3); } break; case 0xd10: /* System Control. */ @@ -483,13 +484,14 @@ static const MemoryRegionOps nvic_sysreg_ops = { static const VMStateDescription vmstate_nvic = { .name = "armv7m_nvic", - .version_id = 1, - .minimum_version_id = 1, + .version_id = 2, + .minimum_version_id = 2, .fields = (VMStateField[]) { VMSTATE_UINT32(systick.control, NVICState), VMSTATE_UINT32(systick.reload, NVICState), VMSTATE_INT64(systick.tick, NVICState), VMSTATE_TIMER_PTR(systick.timer, NVICState), + VMSTATE_UINT32(prigroup, NVICState), VMSTATE_END_OF_LIST() } }; -- cgit v1.2.3-55-g7522 From da6d674e509f0939b2960eef2ce1c3443e9736df Mon Sep 17 00:00:00 2001 From: Michael Davidsaver Date: Tue, 28 Feb 2017 12:08:17 +0000 Subject: armv7m: Rewrite NVIC to not use any GIC code Despite some superficial similarities of register layout, the M-profile NVIC is really very different from the A-profile GIC. Our current attempt to reuse the GIC code means that we have significant bugs in our NVIC. Implement the NVIC as an entirely separate device, to give us somewhere we can get the behaviour correct. This initial commit does not attempt to implement exception priority escalation, since the GIC-based code didn't either. It does fix a few bugs in passing: * ICSR.RETTOBASE polarity was wrong and didn't account for internal exceptions * ICSR.VECTPENDING was 16 too high if the pending exception was for an external interrupt * UsageFault, BusFault and MemFault were not disabled on reset as they are supposed to be Signed-off-by: Michael Davidsaver [PMM: reworked, various bugs and stylistic cleanups] Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 738 ++++++++++++++++++++++++++++++++++++++++---------- hw/intc/trace-events | 15 + 2 files changed, 609 insertions(+), 144 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index ce22001b6c..fb4c985c54 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -17,48 +17,88 @@ #include "hw/sysbus.h" #include "qemu/timer.h" #include "hw/arm/arm.h" +#include "target/arm/cpu.h" #include "exec/address-spaces.h" -#include "gic_internal.h" #include "qemu/log.h" +#include "trace.h" + +/* IRQ number counting: + * + * the num-irq property counts the number of external IRQ lines + * + * NVICState::num_irq counts the total number of exceptions + * (external IRQs, the 15 internal exceptions including reset, + * and one for the unused exception number 0). + * + * NVIC_MAX_IRQ is the highest permitted number of external IRQ lines. + * + * NVIC_MAX_VECTORS is the highest permitted number of exceptions. + * + * Iterating through all exceptions should typically be done with + * for (i = 1; i < s->num_irq; i++) to avoid the unused slot 0. + * + * The external qemu_irq lines are the NVIC's external IRQ lines, + * so line 0 is exception 16. + * + * In the terminology of the architecture manual, "interrupts" are + * a subcategory of exception referring to the external interrupts + * (which are exception numbers NVIC_FIRST_IRQ and upward). + * For historical reasons QEMU tends to use "interrupt" and + * "exception" more or less interchangeably. + */ +#define NVIC_FIRST_IRQ 16 +#define NVIC_MAX_VECTORS 512 +#define NVIC_MAX_IRQ (NVIC_MAX_VECTORS - NVIC_FIRST_IRQ) + +/* Effective running priority of the CPU when no exception is active + * (higher than the highest possible priority value) + */ +#define NVIC_NOEXC_PRIO 0x100 + +typedef struct VecInfo { + /* Exception priorities can range from -3 to 255; only the unmodifiable + * priority values for RESET, NMI and HardFault can be negative. + */ + int16_t prio; + uint8_t enabled; + uint8_t pending; + uint8_t active; + uint8_t level; /* exceptions <=15 never set level */ +} VecInfo; typedef struct NVICState { - GICState gic; + /*< private >*/ + SysBusDevice parent_obj; + /*< public >*/ + ARMCPU *cpu; + VecInfo vectors[NVIC_MAX_VECTORS]; uint32_t prigroup; + /* vectpending and exception_prio are both cached state that can + * be recalculated from the vectors[] array and the prigroup field. + */ + unsigned int vectpending; /* highest prio pending enabled exception */ + int exception_prio; /* group prio of the highest prio active exception */ + struct { uint32_t control; uint32_t reload; int64_t tick; QEMUTimer *timer; } systick; + MemoryRegion sysregmem; - MemoryRegion gic_iomem_alias; MemoryRegion container; + uint32_t num_irq; + qemu_irq excpout; qemu_irq sysresetreq; } NVICState; #define TYPE_NVIC "armv7m_nvic" -/** - * NVICClass: - * @parent_reset: the parent class' reset handler. - * - * A model of the v7M NVIC and System Controller - */ -typedef struct NVICClass { - /*< private >*/ - ARMGICClass parent_class; - /*< public >*/ - DeviceRealize parent_realize; - void (*parent_reset)(DeviceState *dev); -} NVICClass; - -#define NVIC_CLASS(klass) \ - OBJECT_CLASS_CHECK(NVICClass, (klass), TYPE_NVIC) -#define NVIC_GET_CLASS(obj) \ - OBJECT_GET_CLASS(NVICClass, (obj), TYPE_NVIC) + #define NVIC(obj) \ OBJECT_CHECK(NVICState, (obj), TYPE_NVIC) @@ -125,47 +165,283 @@ static void systick_reset(NVICState *s) timer_del(s->systick.timer); } -/* The external routines use the hardware vector numbering, ie. the first - IRQ is #16. The internal GIC routines use #32 as the first IRQ. */ +static int nvic_pending_prio(NVICState *s) +{ + /* return the priority of the current pending interrupt, + * or NVIC_NOEXC_PRIO if no interrupt is pending + */ + return s->vectpending ? s->vectors[s->vectpending].prio : NVIC_NOEXC_PRIO; +} + +/* Return the value of the ISCR RETTOBASE bit: + * 1 if there is exactly one active exception + * 0 if there is more than one active exception + * UNKNOWN if there are no active exceptions (we choose 1, + * which matches the choice Cortex-M3 is documented as making). + * + * NB: some versions of the documentation talk about this + * counting "active exceptions other than the one shown by IPSR"; + * this is only different in the obscure corner case where guest + * code has manually deactivated an exception and is about + * to fail an exception-return integrity check. The definition + * above is the one from the v8M ARM ARM and is also in line + * with the behaviour documented for the Cortex-M3. + */ +static bool nvic_rettobase(NVICState *s) +{ + int irq, nhand = 0; + + for (irq = ARMV7M_EXCP_RESET; irq < s->num_irq; irq++) { + if (s->vectors[irq].active) { + nhand++; + if (nhand == 2) { + return 0; + } + } + } + + return 1; +} + +/* Return the value of the ISCR ISRPENDING bit: + * 1 if an external interrupt is pending + * 0 if no external interrupt is pending + */ +static bool nvic_isrpending(NVICState *s) +{ + int irq; + + /* We can shortcut if the highest priority pending interrupt + * happens to be external or if there is nothing pending. + */ + if (s->vectpending > NVIC_FIRST_IRQ) { + return true; + } + if (s->vectpending == 0) { + return false; + } + + for (irq = NVIC_FIRST_IRQ; irq < s->num_irq; irq++) { + if (s->vectors[irq].pending) { + return true; + } + } + return false; +} + +/* Return a mask word which clears the subpriority bits from + * a priority value for an M-profile exception, leaving only + * the group priority. + */ +static inline uint32_t nvic_gprio_mask(NVICState *s) +{ + return ~0U << (s->prigroup + 1); +} + +/* Recompute vectpending and exception_prio */ +static void nvic_recompute_state(NVICState *s) +{ + int i; + int pend_prio = NVIC_NOEXC_PRIO; + int active_prio = NVIC_NOEXC_PRIO; + int pend_irq = 0; + + for (i = 1; i < s->num_irq; i++) { + VecInfo *vec = &s->vectors[i]; + + if (vec->enabled && vec->pending && vec->prio < pend_prio) { + pend_prio = vec->prio; + pend_irq = i; + } + if (vec->active && vec->prio < active_prio) { + active_prio = vec->prio; + } + } + + s->vectpending = pend_irq; + s->exception_prio = active_prio & nvic_gprio_mask(s); + + trace_nvic_recompute_state(s->vectpending, s->exception_prio); +} + +/* Return the current execution priority of the CPU + * (equivalent to the pseudocode ExecutionPriority function). + * This is a value between -2 (NMI priority) and NVIC_NOEXC_PRIO. + */ +static inline int nvic_exec_prio(NVICState *s) +{ + CPUARMState *env = &s->cpu->env; + int running; + + if (env->daif & PSTATE_F) { /* FAULTMASK */ + running = -1; + } else if (env->daif & PSTATE_I) { /* PRIMASK */ + running = 0; + } else if (env->v7m.basepri > 0) { + running = env->v7m.basepri & nvic_gprio_mask(s); + } else { + running = NVIC_NOEXC_PRIO; /* lower than any possible priority */ + } + /* consider priority of active handler */ + return MIN(running, s->exception_prio); +} + +/* caller must call nvic_irq_update() after this */ +static void set_prio(NVICState *s, unsigned irq, uint8_t prio) +{ + assert(irq > ARMV7M_EXCP_NMI); /* only use for configurable prios */ + assert(irq < s->num_irq); + + s->vectors[irq].prio = prio; + + trace_nvic_set_prio(irq, prio); +} + +/* Recompute state and assert irq line accordingly. + * Must be called after changes to: + * vec->active, vec->enabled, vec->pending or vec->prio for any vector + * prigroup + */ +static void nvic_irq_update(NVICState *s) +{ + int lvl; + int pend_prio; + + nvic_recompute_state(s); + pend_prio = nvic_pending_prio(s); + + /* Raise NVIC output if this IRQ would be taken, except that we + * ignore the effects of the BASEPRI, FAULTMASK and PRIMASK (which + * will be checked for in arm_v7m_cpu_exec_interrupt()); changes + * to those CPU registers don't cause us to recalculate the NVIC + * pending info. + */ + lvl = (pend_prio < s->exception_prio); + trace_nvic_irq_update(s->vectpending, pend_prio, s->exception_prio, lvl); + qemu_set_irq(s->excpout, lvl); +} + +static void armv7m_nvic_clear_pending(void *opaque, int irq) +{ + NVICState *s = (NVICState *)opaque; + VecInfo *vec; + + assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq); + + vec = &s->vectors[irq]; + trace_nvic_clear_pending(irq, vec->enabled, vec->prio); + if (vec->pending) { + vec->pending = 0; + nvic_irq_update(s); + } +} + void armv7m_nvic_set_pending(void *opaque, int irq) { NVICState *s = (NVICState *)opaque; - if (irq >= 16) - irq += 16; - gic_set_pending_private(&s->gic, 0, irq); + VecInfo *vec; + + assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq); + + vec = &s->vectors[irq]; + trace_nvic_set_pending(irq, vec->enabled, vec->prio); + if (!vec->pending) { + vec->pending = 1; + nvic_irq_update(s); + } } /* Make pending IRQ active. */ int armv7m_nvic_acknowledge_irq(void *opaque) { NVICState *s = (NVICState *)opaque; - uint32_t irq; - - irq = gic_acknowledge_irq(&s->gic, 0, MEMTXATTRS_UNSPECIFIED); - if (irq == 1023) - hw_error("Interrupt but no vector\n"); - if (irq >= 32) - irq -= 16; - return irq; + CPUARMState *env = &s->cpu->env; + const int pending = s->vectpending; + const int running = nvic_exec_prio(s); + int pendgroupprio; + VecInfo *vec; + + assert(pending > ARMV7M_EXCP_RESET && pending < s->num_irq); + + vec = &s->vectors[pending]; + + assert(vec->enabled); + assert(vec->pending); + + pendgroupprio = vec->prio & nvic_gprio_mask(s); + assert(pendgroupprio < running); + + trace_nvic_acknowledge_irq(pending, vec->prio); + + vec->active = 1; + vec->pending = 0; + + env->v7m.exception = s->vectpending; + + nvic_irq_update(s); + + return env->v7m.exception; } void armv7m_nvic_complete_irq(void *opaque, int irq) { NVICState *s = (NVICState *)opaque; - if (irq >= 16) - irq += 16; - gic_complete_irq(&s->gic, 0, irq, MEMTXATTRS_UNSPECIFIED); + VecInfo *vec; + + assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq); + + vec = &s->vectors[irq]; + + trace_nvic_complete_irq(irq); + + vec->active = 0; + if (vec->level) { + /* Re-pend the exception if it's still held high; only + * happens for extenal IRQs + */ + assert(irq >= NVIC_FIRST_IRQ); + vec->pending = 1; + } + + nvic_irq_update(s); +} + +/* callback when external interrupt line is changed */ +static void set_irq_level(void *opaque, int n, int level) +{ + NVICState *s = opaque; + VecInfo *vec; + + n += NVIC_FIRST_IRQ; + + assert(n >= NVIC_FIRST_IRQ && n < s->num_irq); + + trace_nvic_set_irq_level(n, level); + + /* The pending status of an external interrupt is + * latched on rising edge and exception handler return. + * + * Pulsing the IRQ will always run the handler + * once, and the handler will re-run until the + * level is low when the handler completes. + */ + vec = &s->vectors[n]; + if (level != vec->level) { + vec->level = level; + if (level) { + armv7m_nvic_set_pending(s, n); + } + } } static uint32_t nvic_readl(NVICState *s, uint32_t offset) { ARMCPU *cpu = s->cpu; uint32_t val; - int irq; switch (offset) { case 4: /* Interrupt Control Type. */ - return (s->num_irq / 32) - 1; + return ((s->num_irq - NVIC_FIRST_IRQ) / 32) - 1; case 0x10: /* SysTick Control and Status. */ val = s->systick.control; s->systick.control &= ~SYSTICK_COUNTFLAG; @@ -195,33 +471,29 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset) case 0xd04: /* Interrupt Control State. */ /* VECTACTIVE */ val = cpu->env.v7m.exception; - if (val == 1023) { - val = 0; - } else if (val >= 32) { - val -= 16; - } /* VECTPENDING */ - if (s->gic.current_pending[0] != 1023) - val |= (s->gic.current_pending[0] << 12); - /* ISRPENDING and RETTOBASE */ - for (irq = 32; irq < s->num_irq; irq++) { - if (s->gic.irq_state[irq].pending) { - val |= (1 << 22); - break; - } - if (irq != cpu->env.v7m.exception && s->gic.irq_state[irq].active) { - val |= (1 << 11); - } + val |= (s->vectpending & 0xff) << 12; + /* ISRPENDING - set if any external IRQ is pending */ + if (nvic_isrpending(s)) { + val |= (1 << 22); + } + /* RETTOBASE - set if only one handler is active */ + if (nvic_rettobase(s)) { + val |= (1 << 11); } /* PENDSTSET */ - if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending) + if (s->vectors[ARMV7M_EXCP_SYSTICK].pending) { val |= (1 << 26); + } /* PENDSVSET */ - if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending) + if (s->vectors[ARMV7M_EXCP_PENDSV].pending) { val |= (1 << 28); + } /* NMIPENDSET */ - if (s->gic.irq_state[ARMV7M_EXCP_NMI].pending) + if (s->vectors[ARMV7M_EXCP_NMI].pending) { val |= (1 << 31); + } + /* ISRPREEMPT not implemented */ return val; case 0xd08: /* Vector Table Offset. */ return cpu->env.v7m.vecbase; @@ -234,20 +506,48 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset) return cpu->env.v7m.ccr; case 0xd24: /* System Handler Status. */ val = 0; - if (s->gic.irq_state[ARMV7M_EXCP_MEM].active) val |= (1 << 0); - if (s->gic.irq_state[ARMV7M_EXCP_BUS].active) val |= (1 << 1); - if (s->gic.irq_state[ARMV7M_EXCP_USAGE].active) val |= (1 << 3); - if (s->gic.irq_state[ARMV7M_EXCP_SVC].active) val |= (1 << 7); - if (s->gic.irq_state[ARMV7M_EXCP_DEBUG].active) val |= (1 << 8); - if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].active) val |= (1 << 10); - if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].active) val |= (1 << 11); - if (s->gic.irq_state[ARMV7M_EXCP_USAGE].pending) val |= (1 << 12); - if (s->gic.irq_state[ARMV7M_EXCP_MEM].pending) val |= (1 << 13); - if (s->gic.irq_state[ARMV7M_EXCP_BUS].pending) val |= (1 << 14); - if (s->gic.irq_state[ARMV7M_EXCP_SVC].pending) val |= (1 << 15); - if (s->gic.irq_state[ARMV7M_EXCP_MEM].enabled) val |= (1 << 16); - if (s->gic.irq_state[ARMV7M_EXCP_BUS].enabled) val |= (1 << 17); - if (s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled) val |= (1 << 18); + if (s->vectors[ARMV7M_EXCP_MEM].active) { + val |= (1 << 0); + } + if (s->vectors[ARMV7M_EXCP_BUS].active) { + val |= (1 << 1); + } + if (s->vectors[ARMV7M_EXCP_USAGE].active) { + val |= (1 << 3); + } + if (s->vectors[ARMV7M_EXCP_SVC].active) { + val |= (1 << 7); + } + if (s->vectors[ARMV7M_EXCP_DEBUG].active) { + val |= (1 << 8); + } + if (s->vectors[ARMV7M_EXCP_PENDSV].active) { + val |= (1 << 10); + } + if (s->vectors[ARMV7M_EXCP_SYSTICK].active) { + val |= (1 << 11); + } + if (s->vectors[ARMV7M_EXCP_USAGE].pending) { + val |= (1 << 12); + } + if (s->vectors[ARMV7M_EXCP_MEM].pending) { + val |= (1 << 13); + } + if (s->vectors[ARMV7M_EXCP_BUS].pending) { + val |= (1 << 14); + } + if (s->vectors[ARMV7M_EXCP_SVC].pending) { + val |= (1 << 15); + } + if (s->vectors[ARMV7M_EXCP_MEM].enabled) { + val |= (1 << 16); + } + if (s->vectors[ARMV7M_EXCP_BUS].enabled) { + val |= (1 << 17); + } + if (s->vectors[ARMV7M_EXCP_USAGE].enabled) { + val |= (1 << 18); + } return val; case 0xd28: /* Configurable Fault Status. */ return cpu->env.v7m.cfsr; @@ -341,14 +641,12 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) if (value & (1 << 28)) { armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV); } else if (value & (1 << 27)) { - s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending = 0; - gic_update(&s->gic); + armv7m_nvic_clear_pending(s, ARMV7M_EXCP_PENDSV); } if (value & (1 << 26)) { armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK); } else if (value & (1 << 25)) { - s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending = 0; - gic_update(&s->gic); + armv7m_nvic_clear_pending(s, ARMV7M_EXCP_SYSTICK); } break; case 0xd08: /* Vector Table Offset. */ @@ -366,6 +664,7 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) qemu_log_mask(LOG_UNIMP, "AIRCR system reset unimplemented\n"); } s->prigroup = extract32(value, 8, 3); + nvic_irq_update(s); } break; case 0xd10: /* System Control. */ @@ -386,9 +685,10 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) case 0xd24: /* System Handler Control. */ /* TODO: Real hardware allows you to set/clear the active bits under some circumstances. We don't implement this. */ - s->gic.irq_state[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0; - s->gic.irq_state[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0; - s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0; + s->vectors[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0; + s->vectors[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0; + s->vectors[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0; + nvic_irq_update(s); break; case 0xd28: /* Configurable Fault Status. */ cpu->env.v7m.cfsr &= ~value; /* W1C */ @@ -410,13 +710,16 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) "NVIC: Aux fault status registers unimplemented\n"); break; case 0xf00: /* Software Triggered Interrupt Register */ + { /* user mode can only write to STIR if CCR.USERSETMPEND permits it */ - if ((value & 0x1ff) < s->num_irq && + int excnum = (value & 0x1ff) + NVIC_FIRST_IRQ; + if (excnum < s->num_irq && (arm_current_el(&cpu->env) || (cpu->env.v7m.ccr & R_V7M_CCR_USERSETMPEND_MASK))) { - gic_set_pending_private(&s->gic, 0, value & 0x1ff); + armv7m_nvic_set_pending(s, excnum); } break; + } default: qemu_log_mask(LOG_GUEST_ERROR, "NVIC: Bad write offset 0x%x\n", offset); @@ -428,28 +731,80 @@ static uint64_t nvic_sysreg_read(void *opaque, hwaddr addr, { NVICState *s = (NVICState *)opaque; uint32_t offset = addr; - int i; + unsigned i, startvec, end; uint32_t val; switch (offset) { + /* reads of set and clear both return the status */ + case 0x100 ... 0x13f: /* NVIC Set enable */ + offset += 0x80; + /* fall through */ + case 0x180 ... 0x1bf: /* NVIC Clear enable */ + val = 0; + startvec = offset - 0x180 + NVIC_FIRST_IRQ; /* vector # */ + + for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) { + if (s->vectors[startvec + i].enabled) { + val |= (1 << i); + } + } + break; + case 0x200 ... 0x23f: /* NVIC Set pend */ + offset += 0x80; + /* fall through */ + case 0x280 ... 0x2bf: /* NVIC Clear pend */ + val = 0; + startvec = offset - 0x280 + NVIC_FIRST_IRQ; /* vector # */ + for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) { + if (s->vectors[startvec + i].pending) { + val |= (1 << i); + } + } + break; + case 0x300 ... 0x33f: /* NVIC Active */ + val = 0; + startvec = offset - 0x300 + NVIC_FIRST_IRQ; /* vector # */ + + for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) { + if (s->vectors[startvec + i].active) { + val |= (1 << i); + } + } + break; + case 0x400 ... 0x5ef: /* NVIC Priority */ + val = 0; + startvec = offset - 0x400 + NVIC_FIRST_IRQ; /* vector # */ + + for (i = 0; i < size && startvec + i < s->num_irq; i++) { + val |= s->vectors[startvec + i].prio << (8 * i); + } + break; case 0xd18 ... 0xd23: /* System Handler Priority. */ val = 0; for (i = 0; i < size; i++) { - val |= s->gic.priority1[(offset - 0xd14) + i][0] << (i * 8); + val |= s->vectors[(offset - 0xd14) + i].prio << (i * 8); } - return val; + break; case 0xfe0 ... 0xfff: /* ID. */ if (offset & 3) { - return 0; + val = 0; + } else { + val = nvic_id[(offset - 0xfe0) >> 2]; + } + break; + default: + if (size == 4) { + val = nvic_readl(s, offset); + } else { + qemu_log_mask(LOG_GUEST_ERROR, + "NVIC: Bad read of size %d at offset 0x%x\n", + size, offset); + val = 0; } - return nvic_id[(offset - 0xfe0) >> 2]; - } - if (size == 4) { - return nvic_readl(s, offset); } - qemu_log_mask(LOG_GUEST_ERROR, - "NVIC: Bad read of size %d at offset 0x%x\n", size, offset); - return 0; + + trace_nvic_sysreg_read(addr, val, size); + return val; } static void nvic_sysreg_write(void *opaque, hwaddr addr, @@ -457,15 +812,59 @@ static void nvic_sysreg_write(void *opaque, hwaddr addr, { NVICState *s = (NVICState *)opaque; uint32_t offset = addr; - int i; + unsigned i, startvec, end; + unsigned setval = 0; + + trace_nvic_sysreg_write(addr, value, size); switch (offset) { + case 0x100 ... 0x13f: /* NVIC Set enable */ + offset += 0x80; + setval = 1; + /* fall through */ + case 0x180 ... 0x1bf: /* NVIC Clear enable */ + startvec = 8 * (offset - 0x180) + NVIC_FIRST_IRQ; + + for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) { + if (value & (1 << i)) { + s->vectors[startvec + i].enabled = setval; + } + } + nvic_irq_update(s); + return; + case 0x200 ... 0x23f: /* NVIC Set pend */ + /* the special logic in armv7m_nvic_set_pending() + * is not needed since IRQs are never escalated + */ + offset += 0x80; + setval = 1; + /* fall through */ + case 0x280 ... 0x2bf: /* NVIC Clear pend */ + startvec = 8 * (offset - 0x280) + NVIC_FIRST_IRQ; /* vector # */ + + for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) { + if (value & (1 << i)) { + s->vectors[startvec + i].pending = setval; + } + } + nvic_irq_update(s); + return; + case 0x300 ... 0x33f: /* NVIC Active */ + return; /* R/O */ + case 0x400 ... 0x5ef: /* NVIC Priority */ + startvec = 8 * (offset - 0x400) + NVIC_FIRST_IRQ; /* vector # */ + + for (i = 0; i < size && startvec + i < s->num_irq; i++) { + set_prio(s, startvec + i, (value >> (i * 8)) & 0xff); + } + nvic_irq_update(s); + return; case 0xd18 ... 0xd23: /* System Handler Priority. */ for (i = 0; i < size; i++) { - s->gic.priority1[(offset - 0xd14) + i][0] = - (value >> (i * 8)) & 0xff; + unsigned hdlidx = (offset - 0xd14) + i; + set_prio(s, hdlidx, (value >> (i * 8)) & 0xff); } - gic_update(&s->gic); + nvic_irq_update(s); return; } if (size == 4) { @@ -482,11 +881,50 @@ static const MemoryRegionOps nvic_sysreg_ops = { .endianness = DEVICE_NATIVE_ENDIAN, }; +static int nvic_post_load(void *opaque, int version_id) +{ + NVICState *s = opaque; + unsigned i; + + /* Check for out of range priority settings */ + if (s->vectors[ARMV7M_EXCP_RESET].prio != -3 || + s->vectors[ARMV7M_EXCP_NMI].prio != -2 || + s->vectors[ARMV7M_EXCP_HARD].prio != -1) { + return 1; + } + for (i = ARMV7M_EXCP_MEM; i < s->num_irq; i++) { + if (s->vectors[i].prio & ~0xff) { + return 1; + } + } + + nvic_recompute_state(s); + + return 0; +} + +static const VMStateDescription vmstate_VecInfo = { + .name = "armv7m_nvic_info", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_INT16(prio, VecInfo), + VMSTATE_UINT8(enabled, VecInfo), + VMSTATE_UINT8(pending, VecInfo), + VMSTATE_UINT8(active, VecInfo), + VMSTATE_UINT8(level, VecInfo), + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_nvic = { .name = "armv7m_nvic", - .version_id = 2, - .minimum_version_id = 2, + .version_id = 3, + .minimum_version_id = 3, + .post_load = &nvic_post_load, .fields = (VMStateField[]) { + VMSTATE_STRUCT_ARRAY(vectors, NVICState, NVIC_MAX_VECTORS, 1, + vmstate_VecInfo, VecInfo), VMSTATE_UINT32(systick.control, NVICState), VMSTATE_UINT32(systick.reload, NVICState), VMSTATE_INT64(systick.tick, NVICState), @@ -496,48 +934,72 @@ static const VMStateDescription vmstate_nvic = { } }; +static Property props_nvic[] = { + /* Number of external IRQ lines (so excluding the 16 internal exceptions) */ + DEFINE_PROP_UINT32("num-irq", NVICState, num_irq, 64), + DEFINE_PROP_END_OF_LIST() +}; + static void armv7m_nvic_reset(DeviceState *dev) { NVICState *s = NVIC(dev); - NVICClass *nc = NVIC_GET_CLASS(s); - nc->parent_reset(dev); - /* Common GIC reset resets to disabled; the NVIC doesn't have - * per-CPU interfaces so mark our non-existent CPU interface - * as enabled by default, and with a priority mask which allows - * all interrupts through. + + s->vectors[ARMV7M_EXCP_NMI].enabled = 1; + s->vectors[ARMV7M_EXCP_HARD].enabled = 1; + /* MEM, BUS, and USAGE are enabled through + * the System Handler Control register */ - s->gic.cpu_ctlr[0] = GICC_CTLR_EN_GRP0; - s->gic.priority_mask[0] = 0x100; - /* The NVIC as a whole is always enabled. */ - s->gic.ctlr = 1; + s->vectors[ARMV7M_EXCP_SVC].enabled = 1; + s->vectors[ARMV7M_EXCP_DEBUG].enabled = 1; + s->vectors[ARMV7M_EXCP_PENDSV].enabled = 1; + s->vectors[ARMV7M_EXCP_SYSTICK].enabled = 1; + + s->vectors[ARMV7M_EXCP_RESET].prio = -3; + s->vectors[ARMV7M_EXCP_NMI].prio = -2; + s->vectors[ARMV7M_EXCP_HARD].prio = -1; + + /* Strictly speaking the reset handler should be enabled. + * However, we don't simulate soft resets through the NVIC, + * and the reset vector should never be pended. + * So we leave it disabled to catch logic errors. + */ + + s->exception_prio = NVIC_NOEXC_PRIO; + s->vectpending = 0; + systick_reset(s); } static void armv7m_nvic_realize(DeviceState *dev, Error **errp) { NVICState *s = NVIC(dev); - NVICClass *nc = NVIC_GET_CLASS(s); - Error *local_err = NULL; s->cpu = ARM_CPU(qemu_get_cpu(0)); assert(s->cpu); - /* The NVIC always has only one CPU */ - s->gic.num_cpu = 1; - /* Tell the common code we're an NVIC */ - s->gic.revision = 0xffffffff; - s->num_irq = s->gic.num_irq; - nc->parent_realize(dev, &local_err); - if (local_err) { - error_propagate(errp, local_err); + + if (s->num_irq > NVIC_MAX_IRQ) { + error_setg(errp, "num-irq %d exceeds NVIC maximum", s->num_irq); return; } - gic_init_irqs_and_distributor(&s->gic); - /* The NVIC and system controller register area looks like this: - * 0..0xff : system control registers, including systick - * 0x100..0xcff : GIC-like registers - * 0xd00..0xfff : system control registers - * We use overlaying to put the GIC like registers - * over the top of the system control register region. + + qdev_init_gpio_in(dev, set_irq_level, s->num_irq); + + /* include space for internal exception vectors */ + s->num_irq += NVIC_FIRST_IRQ; + + /* The NVIC and System Control Space (SCS) starts at 0xe000e000 + * and looks like this: + * 0x004 - ICTR + * 0x010 - 0x1c - systick + * 0x100..0x7ec - NVIC + * 0x7f0..0xcff - Reserved + * 0xd00..0xd3c - SCS registers + * 0xd40..0xeff - Reserved or Not implemented + * 0xf00 - STIR + * + * At the moment there is only one thing in the container region, + * but we leave it in place to allow us to pull systick out into + * its own device object later. */ memory_region_init(&s->container, OBJECT(s), "nvic", 0x1000); /* The system register region goes at the bottom of the priority @@ -546,14 +1008,7 @@ static void armv7m_nvic_realize(DeviceState *dev, Error **errp) memory_region_init_io(&s->sysregmem, OBJECT(s), &nvic_sysreg_ops, s, "nvic_sysregs", 0x1000); memory_region_add_subregion(&s->container, 0, &s->sysregmem); - /* Alias the GIC region so we can get only the section of it - * we need, and layer it on top of the system register region. - */ - memory_region_init_alias(&s->gic_iomem_alias, OBJECT(s), - "nvic-gic", &s->gic.iomem, - 0x100, 0xc00); - memory_region_add_subregion_overlap(&s->container, 0x100, - &s->gic_iomem_alias, 1); + /* Map the whole thing into system memory at the location required * by the v7M architecture. */ @@ -569,36 +1024,31 @@ static void armv7m_nvic_instance_init(Object *obj) * any user-specified property setting, so just modify the * value in the GICState struct. */ - GICState *s = ARM_GIC_COMMON(obj); DeviceState *dev = DEVICE(obj); NVICState *nvic = NVIC(obj); - /* The ARM v7m may have anything from 0 to 496 external interrupt - * IRQ lines. We default to 64. Other boards may differ and should - * set the num-irq property appropriately. - */ - s->num_irq = 64; + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + + sysbus_init_irq(sbd, &nvic->excpout); qdev_init_gpio_out_named(dev, &nvic->sysresetreq, "SYSRESETREQ", 1); } static void armv7m_nvic_class_init(ObjectClass *klass, void *data) { - NVICClass *nc = NVIC_CLASS(klass); DeviceClass *dc = DEVICE_CLASS(klass); - nc->parent_reset = dc->reset; - nc->parent_realize = dc->realize; dc->vmsd = &vmstate_nvic; + dc->props = props_nvic; dc->reset = armv7m_nvic_reset; dc->realize = armv7m_nvic_realize; } static const TypeInfo armv7m_nvic_info = { .name = TYPE_NVIC, - .parent = TYPE_ARM_GIC_COMMON, + .parent = TYPE_SYS_BUS_DEVICE, .instance_init = armv7m_nvic_instance_init, .instance_size = sizeof(NVICState), .class_init = armv7m_nvic_class_init, - .class_size = sizeof(NVICClass), + .class_size = sizeof(SysBusDeviceClass), }; static void armv7m_nvic_register_types(void) diff --git a/hw/intc/trace-events b/hw/intc/trace-events index 39a538d048..729c1288f1 100644 --- a/hw/intc/trace-events +++ b/hw/intc/trace-events @@ -161,3 +161,18 @@ gicv3_redist_write(uint32_t cpu, uint64_t offset, uint64_t data, unsigned size, gicv3_redist_badwrite(uint32_t cpu, uint64_t offset, uint64_t data, unsigned size, bool secure) "GICv3 redistributor %x write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u secure %d: error" gicv3_redist_set_irq(uint32_t cpu, int irq, int level) "GICv3 redistributor %x interrupt %d level changed to %d" gicv3_redist_send_sgi(uint32_t cpu, int irq) "GICv3 redistributor %x pending SGI %d" + +# hw/intc/armv7m_nvic.c +nvic_recompute_state(int vectpending, int exception_prio) "NVIC state recomputed: vectpending %d exception_prio %d" +nvic_set_prio(int irq, uint8_t prio) "NVIC set irq %d priority %d" +nvic_irq_update(int vectpending, int pendprio, int exception_prio, int level) "NVIC vectpending %d pending prio %d exception_prio %d: setting irq line to %d" +nvic_escalate_prio(int irq, int irqprio, int runprio) "NVIC escalating irq %d to HardFault: insufficient priority %d >= %d" +nvic_escalate_disabled(int irq) "NVIC escalating irq %d to HardFault: disabled" +nvic_set_pending(int irq, int en, int prio) "NVIC set pending irq %d (enabled: %d priority %d)" +nvic_clear_pending(int irq, int en, int prio) "NVIC clear pending irq %d (enabled: %d priority %d)" +nvic_set_pending_level(int irq) "NVIC set pending: irq %d higher prio than vectpending: setting irq line to 1" +nvic_acknowledge_irq(int irq, int prio) "NVIC acknowledge IRQ: %d now active (prio %d)" +nvic_complete_irq(int irq) "NVIC complete IRQ %d" +nvic_set_irq_level(int irq, int level) "NVIC external irq %d level set to %d" +nvic_sysreg_read(uint64_t addr, uint32_t value, unsigned size) "NVIC sysreg read addr 0x%" PRIx64 " data 0x%" PRIx32 " size %u" +nvic_sysreg_write(uint64_t addr, uint32_t value, unsigned size) "NVIC sysreg write addr 0x%" PRIx64 " data 0x%" PRIx32 " size %u" -- cgit v1.2.3-55-g7522 From 7ecdaa4a9635f1ded0dfa9218c25273b6d4dcd44 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 28 Feb 2017 12:08:17 +0000 Subject: armv7m: Fix condition check for taking exceptions The M profile condition for when we can take a pending exception or interrupt is not the same as that for A/R profile. The code originally copied from the A/R profile version of the cpu_exec_interrupt function only worked by chance for the very simple case of exceptions being masked by PRIMASK. Replace it with a call to a function in the NVIC code that correctly compares the priority of the pending exception against the current execution priority of the CPU. [Michael Davidsaver's patchset had a patch to do something similar but the implementation ended up being a rewrite.] Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 7 +++++++ target/arm/cpu.c | 16 ++++++++-------- target/arm/cpu.h | 8 ++++++++ 3 files changed, 23 insertions(+), 8 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index fb4c985c54..6a03e2c4c2 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -286,6 +286,13 @@ static inline int nvic_exec_prio(NVICState *s) return MIN(running, s->exception_prio); } +bool armv7m_nvic_can_take_pending_exception(void *opaque) +{ + NVICState *s = opaque; + + return nvic_exec_prio(s) > nvic_pending_prio(s); +} + /* caller must call nvic_irq_update() after this */ static void set_prio(NVICState *s, unsigned irq, uint8_t prio) { diff --git a/target/arm/cpu.c b/target/arm/cpu.c index f7157dc0e5..04b062cb7e 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -338,13 +338,6 @@ static bool arm_v7m_cpu_exec_interrupt(CPUState *cs, int interrupt_request) 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 @@ -354,9 +347,16 @@ static bool arm_v7m_cpu_exec_interrupt(CPUState *cs, int interrupt_request) * the stack if an interrupt occurred at the wrong time. * We avoid this by disabling interrupts when * pc contains a magic address. + * + * ARMv7-M interrupt masking works differently than -A or -R. + * There is no FIQ/IRQ distinction. Instead of I and F bits + * masking FIQ and IRQ interrupts, an exception is taken only + * if it is higher priority than the current execution priority + * (which depends on state like BASEPRI, FAULTMASK and the + * currently active exception). */ if (interrupt_request & CPU_INTERRUPT_HARD - && !(env->daif & PSTATE_I) + && (armv7m_nvic_can_take_pending_exception(env->nvic)) && (env->regs[15] < 0xfffffff0)) { cs->exception_index = EXCP_IRQ; cc->do_interrupt(cs); diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 38a8e00908..649f237561 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1356,6 +1356,14 @@ uint32_t arm_phys_excp_target_el(CPUState *cs, uint32_t excp_idx, uint32_t cur_el, bool secure); /* Interface between CPU and Interrupt controller. */ +#ifndef CONFIG_USER_ONLY +bool armv7m_nvic_can_take_pending_exception(void *opaque); +#else +static inline bool armv7m_nvic_can_take_pending_exception(void *opaque) +{ + return true; +} +#endif void armv7m_nvic_set_pending(void *opaque, int irq); int armv7m_nvic_acknowledge_irq(void *opaque); void armv7m_nvic_complete_irq(void *opaque, int irq); -- cgit v1.2.3-55-g7522 From 7c14b3ac072c48614ca888e101d17ee64312c89f Mon Sep 17 00:00:00 2001 From: Michael Davidsaver Date: Tue, 28 Feb 2017 12:08:17 +0000 Subject: arm: gic: Remove references to NVIC Now that the NVIC is its own separate implementation, we can clean up the GIC code by removing REV_NVIC and conditionals which use it. Signed-off-by: Michael Davidsaver Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée --- hw/intc/arm_gic.c | 31 +++++-------------------------- hw/intc/arm_gic_common.c | 23 ++++++++--------------- hw/intc/gic_internal.h | 7 ++----- 3 files changed, 15 insertions(+), 46 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c index 521aac3cc6..8e5a9d8a3e 100644 --- a/hw/intc/arm_gic.c +++ b/hw/intc/arm_gic.c @@ -156,17 +156,6 @@ static void gic_set_irq_11mpcore(GICState *s, int irq, int level, } } -static void gic_set_irq_nvic(GICState *s, int irq, int level, - int cm, int target) -{ - if (level) { - GIC_SET_LEVEL(irq, cm); - GIC_SET_PENDING(irq, target); - } else { - GIC_CLEAR_LEVEL(irq, cm); - } -} - static void gic_set_irq_generic(GICState *s, int irq, int level, int cm, int target) { @@ -214,8 +203,6 @@ static void gic_set_irq(void *opaque, int irq, int level) if (s->revision == REV_11MPCORE) { gic_set_irq_11mpcore(s, irq, level, cm, target); - } else if (s->revision == REV_NVIC) { - gic_set_irq_nvic(s, irq, level, cm, target); } else { gic_set_irq_generic(s, irq, level, cm, target); } @@ -367,7 +354,7 @@ uint32_t gic_acknowledge_irq(GICState *s, int cpu, MemTxAttrs attrs) return 1023; } - if (s->revision == REV_11MPCORE || s->revision == REV_NVIC) { + if (s->revision == REV_11MPCORE) { /* Clear pending flags for both level and edge triggered interrupts. * Level triggered IRQs will be reasserted once they become inactive. */ @@ -589,11 +576,6 @@ void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs) DPRINTF("Set %d pending mask %x\n", irq, cm); GIC_SET_PENDING(irq, cm); } - } else if (s->revision == REV_NVIC) { - if (GIC_TEST_LEVEL(irq, cm)) { - DPRINTF("Set nvic %d pending mask %x\n", irq, cm); - GIC_SET_PENDING(irq, cm); - } } group = gic_has_groups(s) && GIC_TEST_GROUP(irq, cm); @@ -768,7 +750,7 @@ static uint32_t gic_dist_readb(void *opaque, hwaddr offset, MemTxAttrs attrs) } else if (offset < 0xf10) { goto bad_reg; } else if (offset < 0xf30) { - if (s->revision == REV_11MPCORE || s->revision == REV_NVIC) { + if (s->revision == REV_11MPCORE) { goto bad_reg; } @@ -802,9 +784,6 @@ static uint32_t gic_dist_readb(void *opaque, hwaddr offset, MemTxAttrs attrs) case 2: res = gic_id_gicv2[(offset - 0xfd0) >> 2]; break; - case REV_NVIC: - /* Shouldn't be able to get here */ - abort(); default: res = 0; } @@ -1028,7 +1007,7 @@ static void gic_dist_writeb(void *opaque, hwaddr offset, continue; /* Ignore Non-secure access of Group0 IRQ */ } - if (s->revision == REV_11MPCORE || s->revision == REV_NVIC) { + if (s->revision == REV_11MPCORE) { if (value & (1 << (i * 2))) { GIC_SET_MODEL(irq + i); } else { @@ -1046,7 +1025,7 @@ static void gic_dist_writeb(void *opaque, hwaddr offset, goto bad_reg; } else if (offset < 0xf20) { /* GICD_CPENDSGIRn */ - if (s->revision == REV_11MPCORE || s->revision == REV_NVIC) { + if (s->revision == REV_11MPCORE) { goto bad_reg; } irq = (offset - 0xf10); @@ -1060,7 +1039,7 @@ static void gic_dist_writeb(void *opaque, hwaddr offset, } } else if (offset < 0xf30) { /* GICD_SPENDSGIRn */ - if (s->revision == REV_11MPCORE || s->revision == REV_NVIC) { + if (s->revision == REV_11MPCORE) { goto bad_reg; } irq = (offset - 0xf20); diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c index 4a8df44fb1..70f1134823 100644 --- a/hw/intc/arm_gic_common.c +++ b/hw/intc/arm_gic_common.c @@ -99,9 +99,7 @@ void gic_init_irqs_and_mmio(GICState *s, qemu_irq_handler handler, * [N+32..N+63] PPIs for CPU 1 * ... */ - if (s->revision != REV_NVIC) { - i += (GIC_INTERNAL * s->num_cpu); - } + i += (GIC_INTERNAL * s->num_cpu); qdev_init_gpio_in(DEVICE(s), handler, i); for (i = 0; i < s->num_cpu; i++) { @@ -121,16 +119,12 @@ void gic_init_irqs_and_mmio(GICState *s, qemu_irq_handler handler, memory_region_init_io(&s->iomem, OBJECT(s), ops, s, "gic_dist", 0x1000); sysbus_init_mmio(sbd, &s->iomem); - if (s->revision != REV_NVIC) { - /* This is the main CPU interface "for this core". It is always - * present because it is required by both software emulation and KVM. - * NVIC is not handled here because its CPU interface is different, - * neither it can use KVM. - */ - memory_region_init_io(&s->cpuiomem[0], OBJECT(s), ops ? &ops[1] : NULL, - s, "gic_cpu", s->revision == 2 ? 0x2000 : 0x100); - sysbus_init_mmio(sbd, &s->cpuiomem[0]); - } + /* This is the main CPU interface "for this core". It is always + * present because it is required by both software emulation and KVM. + */ + memory_region_init_io(&s->cpuiomem[0], OBJECT(s), ops ? &ops[1] : NULL, + s, "gic_cpu", s->revision == 2 ? 0x2000 : 0x100); + sysbus_init_mmio(sbd, &s->cpuiomem[0]); } static void arm_gic_common_realize(DeviceState *dev, Error **errp) @@ -162,7 +156,7 @@ static void arm_gic_common_realize(DeviceState *dev, Error **errp) } if (s->security_extn && - (s->revision == REV_11MPCORE || s->revision == REV_NVIC)) { + (s->revision == REV_11MPCORE)) { error_setg(errp, "this GIC revision does not implement " "the security extensions"); return; @@ -255,7 +249,6 @@ static Property arm_gic_common_properties[] = { DEFINE_PROP_UINT32("num-irq", GICState, num_irq, 32), /* Revision can be 1 or 2 for GIC architecture specification * versions 1 or 2, or 0 to indicate the legacy 11MPCore GIC. - * (Internally, 0xffffffff also indicates "not a GIC but an NVIC".) */ DEFINE_PROP_UINT32("revision", GICState, revision, 1), /* True if the GIC should implement the security extensions */ diff --git a/hw/intc/gic_internal.h b/hw/intc/gic_internal.h index 3f311740da..7fe87b13de 100644 --- a/hw/intc/gic_internal.h +++ b/hw/intc/gic_internal.h @@ -25,9 +25,7 @@ #define ALL_CPU_MASK ((unsigned)(((1 << GIC_NCPU) - 1))) -/* The NVIC has 16 internal vectors. However these are not exposed - through the normal GIC interface. */ -#define GIC_BASE_IRQ ((s->revision == REV_NVIC) ? 32 : 0) +#define GIC_BASE_IRQ 0 #define GIC_SET_ENABLED(irq, cm) s->irq_state[irq].enabled |= (cm) #define GIC_CLEAR_ENABLED(irq, cm) s->irq_state[irq].enabled &= ~(cm) @@ -75,7 +73,6 @@ /* The special cases for the revision property: */ #define REV_11MPCORE 0 -#define REV_NVIC 0xffffffff void gic_set_pending_private(GICState *s, int cpu, int irq); uint32_t gic_acknowledge_irq(GICState *s, int cpu, MemTxAttrs attrs); @@ -87,7 +84,7 @@ void gic_set_priority(GICState *s, int cpu, int irq, uint8_t val, static inline bool gic_test_pending(GICState *s, int irq, int cm) { - if (s->revision == REV_NVIC || s->revision == REV_11MPCORE) { + if (s->revision == REV_11MPCORE) { return s->irq_state[irq].pending & cm; } else { /* Edge-triggered interrupts are marked pending on a rising edge, but -- cgit v1.2.3-55-g7522 From a73c98e159d18155445d29b6044be6ad49fd802f Mon Sep 17 00:00:00 2001 From: Michael Davidsaver Date: Tue, 28 Feb 2017 12:08:17 +0000 Subject: armv7m: Escalate exceptions to HardFault if necessary The v7M exception architecture requires that if a synchronous exception cannot be taken immediately (because it is disabled or at too low a priority) then it should be escalated to HardFault (and the HardFault exception is then taken). Implement this escalation logic. Signed-off-by: Michael Davidsaver [PMM: extracted from another patch] Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++ target/arm/helper.c | 2 -- 2 files changed, 53 insertions(+), 2 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 6a03e2c4c2..479acfcae9 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 bcedb4a808..2fc6802028 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); -- cgit v1.2.3-55-g7522 From a5d8235545e98c1ce02560d5f4f57552d937efe9 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 28 Feb 2017 12:08:18 +0000 Subject: armv7m: Remove unused armv7m_nvic_acknowledge_irq() return value Having armv7m_nvic_acknowledge_irq() return the new value of env->v7m.exception and its one caller assign the return value back to env->v7m.exception is pointless. Just make the return type void instead. Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 4 +--- target/arm/cpu.h | 2 +- target/arm/helper.c | 2 +- 3 files changed, 3 insertions(+), 5 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 479acfcae9..9336bca142 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -412,7 +412,7 @@ void armv7m_nvic_set_pending(void *opaque, int irq) } /* Make pending IRQ active. */ -int armv7m_nvic_acknowledge_irq(void *opaque) +void armv7m_nvic_acknowledge_irq(void *opaque) { NVICState *s = (NVICState *)opaque; CPUARMState *env = &s->cpu->env; @@ -439,8 +439,6 @@ int armv7m_nvic_acknowledge_irq(void *opaque) env->v7m.exception = s->vectpending; nvic_irq_update(s); - - return env->v7m.exception; } void armv7m_nvic_complete_irq(void *opaque, int irq) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 649f237561..68ad00c480 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1365,7 +1365,7 @@ static inline bool armv7m_nvic_can_take_pending_exception(void *opaque) } #endif void armv7m_nvic_set_pending(void *opaque, int irq); -int armv7m_nvic_acknowledge_irq(void *opaque); +void armv7m_nvic_acknowledge_irq(void *opaque); void armv7m_nvic_complete_irq(void *opaque, int irq); /* Interface for defining coprocessor registers. diff --git a/target/arm/helper.c b/target/arm/helper.c index 2fc6802028..85d13647cd 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6142,7 +6142,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_DEBUG); return; case EXCP_IRQ: - env->v7m.exception = armv7m_nvic_acknowledge_irq(env->nvic); + armv7m_nvic_acknowledge_irq(env->nvic); break; case EXCP_EXCEPTION_EXIT: do_v7m_exception_exit(env); -- cgit v1.2.3-55-g7522 From 14790f730a9b7da026f5562505d1004f67abebf5 Mon Sep 17 00:00:00 2001 From: Michael Davidsaver Date: Tue, 28 Feb 2017 12:08:18 +0000 Subject: armv7m: VECTCLRACTIVE and VECTRESET are UNPREDICTABLE The VECTCLRACTIVE and VECTRESET bits in the AIRCR are both documented as UNPREDICTABLE if you write a 1 to them when the processor is not halted in Debug state (ie stopped and under the control of an external JTAG debugger). Since we don't implement Debug state or emulated JTAG these bits are always UNPREDICTABLE for us. Instead of logging them as unimplemented we can simply log writes as guest errors and ignore them. Signed-off-by: Michael Davidsaver [PMM: change extracted from another patch; commit message constructed from scratch] Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 9336bca142..456480a3f2 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -716,10 +716,14 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) qemu_irq_pulse(s->sysresetreq); } if (value & 2) { - qemu_log_mask(LOG_UNIMP, "VECTCLRACTIVE unimplemented\n"); + qemu_log_mask(LOG_GUEST_ERROR, + "Setting VECTCLRACTIVE when not in DEBUG mode " + "is UNPREDICTABLE\n"); } if (value & 1) { - qemu_log_mask(LOG_UNIMP, "AIRCR system reset unimplemented\n"); + qemu_log_mask(LOG_GUEST_ERROR, + "Setting VECTRESET when not in DEBUG mode " + "is UNPREDICTABLE\n"); } s->prigroup = extract32(value, 8, 3); nvic_irq_update(s); -- cgit v1.2.3-55-g7522 From aa488fe3bb5460c6675800ccd80f6dccbbd70159 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 28 Feb 2017 12:08:19 +0000 Subject: armv7m: Check exception return consistency Implement the exception return consistency checks described in the v7M pseudocode ExceptionReturn(). Inspired by a patch from Michael Davidsaver's series, but this is a reimplementation from scratch based on the ARM ARM pseudocode. Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 12 +++++- target/arm/cpu.h | 12 +++++- target/arm/helper.c | 112 +++++++++++++++++++++++++++++++++++++++++++++----- 3 files changed, 123 insertions(+), 13 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 456480a3f2..718b1a1034 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -441,10 +441,11 @@ void armv7m_nvic_acknowledge_irq(void *opaque) nvic_irq_update(s); } -void armv7m_nvic_complete_irq(void *opaque, int irq) +int armv7m_nvic_complete_irq(void *opaque, int irq) { NVICState *s = (NVICState *)opaque; VecInfo *vec; + int ret; assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq); @@ -452,6 +453,13 @@ void armv7m_nvic_complete_irq(void *opaque, int irq) trace_nvic_complete_irq(irq); + if (!vec->active) { + /* Tell the caller this was an illegal exception return */ + return -1; + } + + ret = nvic_rettobase(s); + vec->active = 0; if (vec->level) { /* Re-pend the exception if it's still held high; only @@ -462,6 +470,8 @@ void armv7m_nvic_complete_irq(void *opaque, int irq) } nvic_irq_update(s); + + return ret; } /* callback when external interrupt line is changed */ diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 68ad00c480..045830aeae 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1366,7 +1366,17 @@ static inline bool armv7m_nvic_can_take_pending_exception(void *opaque) #endif void armv7m_nvic_set_pending(void *opaque, int irq); void armv7m_nvic_acknowledge_irq(void *opaque); -void armv7m_nvic_complete_irq(void *opaque, int irq); +/** + * armv7m_nvic_complete_irq: complete specified interrupt or exception + * @opaque: the NVIC + * @irq: the exception number to complete + * + * Returns: -1 if the irq was not active + * 1 if completing this irq brought us back to base (no active irqs) + * 0 if there is still an irq active after this one was completed + * (Ignoring -1, this is the same as the RETTOBASE value before completion.) + */ +int armv7m_nvic_complete_irq(void *opaque, int irq); /* Interface for defining coprocessor registers. * Registers are defined in tables of arm_cp_reginfo structs diff --git a/target/arm/helper.c b/target/arm/helper.c index be731dce54..9081771656 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6068,22 +6068,99 @@ static void v7m_push_stack(ARMCPU *cpu) v7m_push(env, env->regs[0]); } -static void do_v7m_exception_exit(CPUARMState *env) +static void do_v7m_exception_exit(ARMCPU *cpu) { + CPUARMState *env = &cpu->env; uint32_t type; uint32_t xpsr; - + bool ufault = false; + bool return_to_sp_process = false; + bool return_to_handler = false; + bool rettobase = false; + + /* We can only get here from an EXCP_EXCEPTION_EXIT, and + * arm_v7m_do_unassigned_access() enforces the architectural rule + * that jumps to magic addresses don't have magic behaviour unless + * we're in Handler mode (compare pseudocode BXWritePC()). + */ + assert(env->v7m.exception != 0); + + /* In the spec pseudocode ExceptionReturn() is called directly + * from BXWritePC() and gets the full target PC value including + * bit zero. In QEMU's implementation we treat it as a normal + * jump-to-register (which is then caught later on), and so split + * the target value up between env->regs[15] and env->thumb in + * gen_bx(). Reconstitute it. + */ type = env->regs[15]; + if (env->thumb) { + type |= 1; + } + + qemu_log_mask(CPU_LOG_INT, "Exception return: magic PC %" PRIx32 + " previous exception %d\n", + type, env->v7m.exception); + + if (extract32(type, 5, 23) != extract32(-1, 5, 23)) { + qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero high bits in exception " + "exit PC value 0x%" PRIx32 " are UNPREDICTABLE\n", type); + } + if (env->v7m.exception != ARMV7M_EXCP_NMI) { /* Auto-clear FAULTMASK on return from other than NMI */ env->daif &= ~PSTATE_F; } - if (env->v7m.exception != 0) { - armv7m_nvic_complete_irq(env->nvic, env->v7m.exception); + + switch (armv7m_nvic_complete_irq(env->nvic, env->v7m.exception)) { + case -1: + /* attempt to exit an exception that isn't active */ + ufault = true; + break; + case 0: + /* still an irq active now */ + break; + case 1: + /* we returned to base exception level, no nesting. + * (In the pseudocode this is written using "NestedActivation != 1" + * where we have 'rettobase == false'.) + */ + rettobase = true; + break; + default: + g_assert_not_reached(); + } + + switch (type & 0xf) { + case 1: /* Return to Handler */ + return_to_handler = true; + break; + case 13: /* Return to Thread using Process stack */ + return_to_sp_process = true; + /* fall through */ + case 9: /* Return to Thread using Main stack */ + if (!rettobase && + !(env->v7m.ccr & R_V7M_CCR_NONBASETHRDENA_MASK)) { + ufault = true; + } + break; + default: + ufault = true; + } + + if (ufault) { + /* Bad exception return: instead of popping the exception + * stack, directly take a usage fault on the current stack. + */ + env->v7m.cfsr |= R_V7M_CFSR_INVPC_MASK; + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE); + v7m_exception_taken(cpu, type | 0xf0000000); + qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing " + "stackframe: failed exception return integrity check\n"); + return; } /* Switch to the target stack. */ - switch_v7m_sp(env, (type & 4) != 0); + switch_v7m_sp(env, return_to_sp_process); /* Pop registers. */ env->regs[0] = v7m_pop(env); env->regs[1] = v7m_pop(env); @@ -6107,11 +6184,24 @@ static void do_v7m_exception_exit(CPUARMState *env) /* Undo stack alignment. */ if (xpsr & 0x200) env->regs[13] |= 4; - /* ??? The exception return type specifies Thread/Handler mode. However - this is also implied by the xPSR value. Not sure what to do - if there is a mismatch. */ - /* ??? Likewise for mismatches between the CONTROL register and the stack - pointer. */ + + /* The restored xPSR exception field will be zero if we're + * resuming in Thread mode. If that doesn't match what the + * exception return type specified then this is a UsageFault. + */ + if (return_to_handler == (env->v7m.exception == 0)) { + /* Take an INVPC UsageFault by pushing the stack again. */ + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE); + env->v7m.cfsr |= R_V7M_CFSR_INVPC_MASK; + v7m_push_stack(cpu); + v7m_exception_taken(cpu, type | 0xf0000000); + qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on new stackframe: " + "failed exception return integrity check\n"); + return; + } + + /* Otherwise, we have a successful exception exit. */ + qemu_log_mask(CPU_LOG_INT, "...successful exception return\n"); } static void arm_log_exception(int idx) @@ -6184,7 +6274,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) case EXCP_IRQ: break; case EXCP_EXCEPTION_EXIT: - do_v7m_exception_exit(env); + do_v7m_exception_exit(cpu); return; default: cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index); -- cgit v1.2.3-55-g7522 From 5db53e353dfe08492aca793b4748d8182f9780b3 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 28 Feb 2017 12:08:19 +0000 Subject: armv7m: Allow SHCSR writes to change pending and active bits Implement the NVIC SHCSR write behaviour which allows pending and active status of some exceptions to be changed. Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée --- hw/intc/armv7m_nvic.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'hw/intc') diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 718b1a1034..76097b4830 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -755,8 +755,17 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value) cpu->env.v7m.ccr = value; break; case 0xd24: /* System Handler Control. */ - /* TODO: Real hardware allows you to set/clear the active bits - under some circumstances. We don't implement this. */ + s->vectors[ARMV7M_EXCP_MEM].active = (value & (1 << 0)) != 0; + s->vectors[ARMV7M_EXCP_BUS].active = (value & (1 << 1)) != 0; + s->vectors[ARMV7M_EXCP_USAGE].active = (value & (1 << 3)) != 0; + s->vectors[ARMV7M_EXCP_SVC].active = (value & (1 << 7)) != 0; + s->vectors[ARMV7M_EXCP_DEBUG].active = (value & (1 << 8)) != 0; + s->vectors[ARMV7M_EXCP_PENDSV].active = (value & (1 << 10)) != 0; + s->vectors[ARMV7M_EXCP_SYSTICK].active = (value & (1 << 11)) != 0; + s->vectors[ARMV7M_EXCP_USAGE].pending = (value & (1 << 12)) != 0; + s->vectors[ARMV7M_EXCP_MEM].pending = (value & (1 << 13)) != 0; + s->vectors[ARMV7M_EXCP_BUS].pending = (value & (1 << 14)) != 0; + s->vectors[ARMV7M_EXCP_SVC].pending = (value & (1 << 15)) != 0; s->vectors[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0; s->vectors[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0; s->vectors[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0; -- cgit v1.2.3-55-g7522