perf/arm-cmn: Initialise cmn->cpu earlier

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.1747069914.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
[ backport past NUMA changes in 5.17 ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index ac4428e8fae929e9db98a2945058b8bab2444615..4294ba946b9c8682c7116ef185dd91767f491594 100644 (file)
--- 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,