diff mbox

[1/3] arm-ccn: fix PMU interrupt flags

Message ID 1470909043-7663-2-git-send-email-mark.rutland@arm.com
State Accepted
Commit 0811ef7e2f5470833a353426a6fbe0b845aea926
Headers show

Commit Message

Mark Rutland Aug. 11, 2016, 9:50 a.m. UTC 
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 <mark.rutland@arm.com>

Acked-by: Pawel Moll <pawel.moll@arm.com>

Reviewed-by: Will Deacon <will.deacon@arm.com>

---
 drivers/bus/arm-ccn.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

-- 
1.9.1


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diff mbox

Patch

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index cbb2771..28b1d66 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -1475,8 +1475,9 @@  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;