From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41632) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1drP83-0001cu-02 for qemu-devel@nongnu.org; Mon, 11 Sep 2017 09:52:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1drP82-0002AW-7K for qemu-devel@nongnu.org; Mon, 11 Sep 2017 09:51:59 -0400 From: Peter Maydell Date: Mon, 11 Sep 2017 14:52:07 +0100 Message-Id: <1505137930-13255-5-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1505137930-13255-1-git-send-email-peter.maydell@linaro.org> References: <1505137930-13255-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PATCH 4/7] nvic: Don't apply group priority mask to negative priorities List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Cc: patches@linaro.org 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 --- hw/intc/armv7m_nvic.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) 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); -- 2.7.4