Commit 0811ef7e authored by Mark Rutland's avatar Mark Rutland Committed by Pawel Moll

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: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarPawel Moll <pawel.moll@arm.com>
Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
parent 3249bce4
...@@ -1496,8 +1496,9 @@ static int arm_ccn_probe(struct platform_device *pdev) ...@@ -1496,8 +1496,9 @@ static int arm_ccn_probe(struct platform_device *pdev)
/* Can set 'disable' bits, so can acknowledge interrupts */ /* Can set 'disable' bits, so can acknowledge interrupts */
writel(CCN_MN_ERRINT_STATUS__PMU_EVENTS__ENABLE, writel(CCN_MN_ERRINT_STATUS__PMU_EVENTS__ENABLE,
ccn->base + CCN_MN_ERRINT_STATUS); ccn->base + CCN_MN_ERRINT_STATUS);
err = devm_request_irq(ccn->dev, irq, arm_ccn_irq_handler, 0, err = devm_request_irq(ccn->dev, irq, arm_ccn_irq_handler,
dev_name(ccn->dev), ccn); IRQF_NOBALANCING | IRQF_NO_THREAD,
dev_name(ccn->dev), ccn);
if (err) if (err)
return err; return err;
......
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