| Message ID | 1505137930-13255-5-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ARMv8M: some bugfixes and prep. cleanup | expand |
On 09/11/2017 06:52 AM, Peter Maydell wrote: > In several places we were unconditionally applying the > nvic_gprio_mask() to a priority value. This is incorrect > if the priority is one of the fixed negative priority > values (for NMI and HardFault), so don't do it. > > This bug would have caused both NMI and HardFault to be > considered as the same priority and so NMI wouldn't > correctly preempt HardFault. > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > hw/intc/armv7m_nvic.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 1fecfd6..d3e2056 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -152,8 +152,12 @@ static void nvic_recompute_state(NVICState *s) } } + if (active_prio > 0) { + active_prio &= nvic_gprio_mask(s); + } + s->vectpending = pend_irq; - s->exception_prio = active_prio & nvic_gprio_mask(s); + s->exception_prio = active_prio; trace_nvic_recompute_state(s->vectpending, s->exception_prio); } @@ -329,7 +333,10 @@ void armv7m_nvic_acknowledge_irq(void *opaque) assert(vec->enabled); assert(vec->pending); - pendgroupprio = vec->prio & nvic_gprio_mask(s); + pendgroupprio = vec->prio; + if (pendgroupprio > 0) { + pendgroupprio &= nvic_gprio_mask(s); + } assert(pendgroupprio < running); trace_nvic_acknowledge_irq(pending, vec->prio);
In several places we were unconditionally applying the nvic_gprio_mask() to a priority value. This is incorrect if the priority is one of the fixed negative priority values (for NMI and HardFault), so don't do it. This bug would have caused both NMI and HardFault to be considered as the same priority and so NMI wouldn't correctly preempt HardFault. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- hw/intc/armv7m_nvic.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) -- 2.7.4