From 0811ef7e2f5470833a353426a6fbe0b845aea926 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 11 Aug 2016 10:50:41 +0100 Subject: [PATCH] bus: arm-ccn: fix PMU interrupt flags Currently the IRQ core is permitted to make the CCN PMU IRQ handler threaded, and will allow userspace to change the CPU affinity of the interrupt behind our back. Both of these could violate our synchronisation requirements with the core perf code, which relies upon strict CPU affinity and disabling of interrupts to guarantee mutual exclusion in some cases. As with the CPU PMU drivers, we should request the interrupt with IRQF_NOBALANCING and IRQF_NO_THREAD, to avoid these issues. Signed-off-by: Mark Rutland Acked-by: Pawel Moll Reviewed-by: Will Deacon Signed-off-by: Pawel Moll --- drivers/bus/arm-ccn.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index 02f81e308dff..c826bb286054 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -1496,8 +1496,9 @@ static int arm_ccn_probe(struct platform_device *pdev) /* Can set 'disable' bits, so can acknowledge interrupts */ writel(CCN_MN_ERRINT_STATUS__PMU_EVENTS__ENABLE, ccn->base + CCN_MN_ERRINT_STATUS); - err = devm_request_irq(ccn->dev, irq, arm_ccn_irq_handler, 0, - dev_name(ccn->dev), ccn); + err = devm_request_irq(ccn->dev, irq, arm_ccn_irq_handler, + IRQF_NOBALANCING | IRQF_NO_THREAD, + dev_name(ccn->dev), ccn); if (err) return err; -- 2.20.1