commit 597704e201068db3d104de3c7a4d447ff8209127 upstream.

For all the complexity of handling affinity for CPU hotplug, what we've apparently managed to overlook is that arm_cmn_init_irqs() has in fact always been setting the *initial* affinity of all IRQs to CPU 0, not the CPU we subsequently choose for event scheduling. Oh dear.

Cc: stable@vger.kernel.org Fixes: 0ba64770a2f2 ("perf: Add Arm CMN-600 PMU driver") Signed-off-by: Robin Murphy robin.murphy@arm.com Reviewed-by: Ilkka Koskinen ilkka@os.amperecomputing.com Link: https://lore.kernel.org/r/b12fccba6b5b4d2674944f59e4daad91cd63420b.174706991... Signed-off-by: Will Deacon will@kernel.org [ backport past NUMA changes in 5.17 ] Signed-off-by: Robin Murphy robin.murphy@arm.com --- drivers/perf/arm-cmn.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c index e2a055ba0b7a..cabeff8c944b 100644 --- a/drivers/perf/arm-cmn.c +++ b/drivers/perf/arm-cmn.c @@ -1512,6 +1512,7 @@ static int arm_cmn_probe(struct platform_device *pdev) return -ENOMEM;

cmn->dev = &pdev->dev; + cmn->cpu = raw_smp_processor_id(); platform_set_drvdata(pdev, cmn);

if (has_acpi_companion(cmn->dev)) @@ -1533,7 +1534,6 @@ static int arm_cmn_probe(struct platform_device *pdev) if (err) return err;

- cmn->cpu = raw_smp_processor_id(); cmn->pmu = (struct pmu) { .module = THIS_MODULE, .attr_groups = arm_cmn_attr_groups,