hw/intc/armv7m_nvic: for v8.1M VECTPENDING hides S exceptions from NS

In Arm v8.1M the VECTPENDING field in the ICSR has new behaviour: if
the register is accessed NonSecure and the highest priority pending
enabled exception (that would be returned in the VECTPENDING field)
targets Secure, then the VECTPENDING field must read 1 rather than
the exception number of the pending exception. Implement this.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210723162146.5167-7-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2021-07-23 17:21:46 +01:00
parent 7caad65756
commit 845d27a913

View file

@ -804,6 +804,16 @@ void armv7m_nvic_acknowledge_irq(void *opaque)
nvic_irq_update(s);
}
static bool vectpending_targets_secure(NVICState *s)
{
/* Return true if s->vectpending targets Secure state */
if (s->vectpending_is_s_banked) {
return true;
}
return !exc_is_banked(s->vectpending) &&
exc_targets_secure(s, s->vectpending);
}
void armv7m_nvic_get_pending_irq_info(void *opaque,
int *pirq, bool *ptargets_secure)
{
@ -813,12 +823,7 @@ void armv7m_nvic_get_pending_irq_info(void *opaque,
assert(pending > ARMV7M_EXCP_RESET && pending < s->num_irq);
if (s->vectpending_is_s_banked) {
targets_secure = true;
} else {
targets_secure = !exc_is_banked(pending) &&
exc_targets_secure(s, pending);
}
targets_secure = vectpending_targets_secure(s);
trace_nvic_get_pending_irq_info(pending, targets_secure);
@ -1039,7 +1044,19 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset, MemTxAttrs attrs)
/* VECTACTIVE */
val = cpu->env.v7m.exception;
/* VECTPENDING */
val |= (s->vectpending & 0x1ff) << 12;
if (s->vectpending) {
/*
* From v8.1M VECTPENDING must read as 1 if accessed as
* NonSecure and the highest priority pending and enabled
* exception targets Secure.
*/
int vp = s->vectpending;
if (!attrs.secure && arm_feature(&cpu->env, ARM_FEATURE_V8_1M) &&
vectpending_targets_secure(s)) {
vp = 1;
}
val |= (vp & 0x1ff) << 12;
}
/* ISRPENDING - set if any external IRQ is pending */
if (nvic_isrpending(s)) {
val |= (1 << 22);