[PATCH] drivers/perf: arm-pmu: Fix handling of SPI lacking "interrupt-affinity" property

Patch 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt
affinity mask") added support for partitionned PPI setups, but
inadvertently broke setups using SPIs without the "interrupt-affinity"
property (which is the case for UP platforms).

This patch restore the broken functionnality by testing whether the
interrupt is percpu or not instead of relying on the using_spi flag
that really means "SPI *and* interrupt-affinity property".

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt affinity mask")
Signed-off-by: Marc Zyngier <redacted>
---
 drivers/perf/arm_pmu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 2513365..9275e08 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c

@@ -958,11 +958,12 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
 
 	/* If we didn't manage to parse anything, try the interrupt affinity */
 	if (cpumask_weight(&pmu->supported_cpus) == 0) {
-		if (!using_spi) {
+		int irq = platform_get_irq(pdev, 0);
+
+		if (irq_is_percpu(irq)) {
 			/* If using PPIs, check the affinity of the partition */
-			int ret, irq;
+			int ret;
 
-			irq = platform_get_irq(pdev, 0);
 			ret = irq_get_percpu_devid_partition(irq, &pmu->supported_cpus);
 			if (ret) {
 				kfree(irqs);

-- 
2.1.4

On Tue, Jul 19, 2016 at 03:39:02PM +0100, Marc Zyngier wrote:

Patch 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt
affinity mask") added support for partitionned PPI setups, but
inadvertently broke setups using SPIs without the "interrupt-affinity"
property (which is the case for UP platforms).

This patch restore the broken functionnality by testing whether the
interrupt is percpu or not instead of relying on the using_spi flag
that really means "SPI *and* interrupt-affinity property".

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt affinity mask")
Signed-off-by: Marc Zyngier <redacted>
---
 drivers/perf/arm_pmu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Thanks, looks good to me:

Acked-by: Will Deacon <redacted>

Catalin, can you pick this up, please?

Will

Hi Marc,

On Tue, Jul 19, 2016 at 9:39 AM, Marc Zyngier [off-list ref] wrote:

Patch 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt
affinity mask") added support for partitionned PPI setups, but
inadvertently broke setups using SPIs without the "interrupt-affinity"
property (which is the case for UP platforms).

This patch restore the broken functionnality by testing whether the
interrupt is percpu or not instead of relying on the using_spi flag
that really means "SPI *and* interrupt-affinity property".

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt affinity mask")
Signed-off-by: Marc Zyngier <redacted>

kernelci.org detected boot failures on bcm2835-rpi-b in mainline[1]
and was bisected down to this patch.  I verified that reverting this
patch on top of mainline gets bcm2835-rpi-b booting again.

I haven't been closely tracking this change, but a quick glance and it
looks like this platform is possibly missing IRQ properties from its
PMU node?  The DT for this platform simply has:

        arm-pmu {
            compatible = "arm,arm1176-pmu";
        };

Kevin

[1] https://kernelci.org/boot/id/57bb4d9259b514895348b564/

Hi Kevin,

Thanks for reporting this.

On Fri, Aug 26, 2016 at 12:11:55PM -0500, Kevin Hilman wrote:

On Tue, Jul 19, 2016 at 9:39 AM, Marc Zyngier [off-list ref] wrote:

quoted

Patch 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt
affinity mask") added support for partitionned PPI setups, but
inadvertently broke setups using SPIs without the "interrupt-affinity"
property (which is the case for UP platforms).

This patch restore the broken functionnality by testing whether the
interrupt is percpu or not instead of relying on the using_spi flag
that really means "SPI *and* interrupt-affinity property".

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt affinity mask")
Signed-off-by: Marc Zyngier <redacted>

kernelci.org detected boot failures on bcm2835-rpi-b in mainline[1]
and was bisected down to this patch.  I verified that reverting this
patch on top of mainline gets bcm2835-rpi-b booting again.

I haven't been closely tracking this change, but a quick glance and it
looks like this platform is possibly missing IRQ properties from its
PMU node?  The DT for this platform simply has:

        arm-pmu {
            compatible = "arm,arm1176-pmu";
        };

Stefan Wahren posted a fix for this, so I've queued it locally and plan
to send via Catalin:

  http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/452475.html

Will