* pmu: armv7_a9_pmu_init() fails with -ENXIO
@ 2015-10-21 13:01 Mason
2015-10-21 13:46 ` Mason
0 siblings, 1 reply; 5+ messages in thread
From: Mason @ 2015-10-21 13:01 UTC (permalink / raw)
To: linux-arm-kernel
Hello,
On my (dual-core) system, armv7_a9_pmu_init() fails with -ENXIO
(I'm running v4.2)
[ 0.090148] cpu=4 nr_cpu_ids=2
[ 0.090164] armv7_a9_pmu_init: ret=-6
[ 0.090171] hw perfevents: failed to probe PMU!
[ 0.090175] hw perfevents: failed to register PMU devices!
armv7_a9_pmu_init() eventually calls generic_exec_single()
which fails this test:
if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu))
cpu = 4 looks fishy, doesn't it?
<grasping@straws> I'm wondering if commit 0e3038d18adce or
commit cc88116da0d18 might be related at all?
The value 4 comes from smp_call_function_any()
/* Any online will do: smp_call_function_single handles nr_cpu_ids. */
cpu = cpumask_any_and(mask, cpu_online_mask);
mask = &arm_pmu->supported_cpus
p arm_pmu->supported_cpus
$3 = {bits = {0}}
/**
* cpumask_next_and - get the next cpu in *src1p & *src2p
* @n: the cpu prior to the place to search (ie. return will be > @n)
* @src1p: the first cpumask pointer
* @src2p: the second cpumask pointer
*
* Returns >= nr_cpu_ids if no further cpus set in both.
*/
Shouldn't cpu_pmu->supported_cpus be cpu_present_mask or cpu_possible_mask?
Shouldn't armv7pmu_init() set arm_pmu->supported_cpus?
Regards.
^ permalink raw reply [flat|nested] 5+ messages in thread* pmu: armv7_a9_pmu_init() fails with -ENXIO 2015-10-21 13:01 pmu: armv7_a9_pmu_init() fails with -ENXIO Mason @ 2015-10-21 13:46 ` Mason 2015-10-21 14:27 ` Sudeep Holla 0 siblings, 1 reply; 5+ messages in thread From: Mason @ 2015-10-21 13:46 UTC (permalink / raw) To: linux-arm-kernel On 21/10/2015 15:01, Mason wrote: > On my (dual-core) system, armv7_a9_pmu_init() fails with -ENXIO > (I'm running v4.2) > > [ 0.090148] cpu=4 nr_cpu_ids=2 > [ 0.090164] armv7_a9_pmu_init: ret=-6 > [ 0.090171] hw perfevents: failed to probe PMU! > [ 0.090175] hw perfevents: failed to register PMU devices! > > armv7_a9_pmu_init() eventually calls generic_exec_single() > which fails this test: > > if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu)) > > cpu = 4 looks fishy, doesn't it? > <grasping@straws> I'm wondering if commit 0e3038d18adce or > commit cc88116da0d18 might be related at all? > > The value 4 comes from smp_call_function_any() > > /* Any online will do: smp_call_function_single handles nr_cpu_ids. */ > cpu = cpumask_any_and(mask, cpu_online_mask); > > mask = &arm_pmu->supported_cpus > p arm_pmu->supported_cpus > $3 = {bits = {0}} > > /** > * cpumask_next_and - get the next cpu in *src1p & *src2p > * @n: the cpu prior to the place to search (ie. return will be > @n) > * @src1p: the first cpumask pointer > * @src2p: the second cpumask pointer > * > * Returns >= nr_cpu_ids if no further cpus set in both. > */ > > Shouldn't cpu_pmu->supported_cpus be cpu_present_mask or cpu_possible_mask? > Shouldn't armv7pmu_init() set arm_pmu->supported_cpus? Looking more closely at Documentation/devicetree/bindings/arm/pmu.txt I now see commit 71bbf038eaa44 - interrupt-affinity : Valid only when using SPIs, specifies a list of phandles to CPU nodes corresponding directly to the affinity of the SPIs listed in the interrupts property. This property should be present when there is more than a single SPI. I currently have pmu { compatible = "arm,cortex-a9-pmu"; interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>, <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>; }; <confused> I wrote the above node by sampling other platforms, and they don't define any interrupt-affinity property, e.g. exynos4415.dtsi: pmu { compatible = "arm,cortex-a9-pmu"; interrupts = <0 18 0>, <0 19 0>, <0 20 0>, <0 21 0>; }; exynos5440.dtsi: arm-pmu { compatible = "arm,cortex-a15-pmu", "arm,cortex-a9-pmu"; interrupts = <0 52 4>, <0 53 4>, <0 54 4>, <0 55 4>; }; highbank.dts: pmu { compatible = "arm,cortex-a9-pmu"; interrupts = <0 76 4 0 75 4 0 74 4 0 73 4>; }; omap4460.dtsi: pmu { compatible = "arm,cortex-a9-pmu"; interrupts = <GIC_SPI 54 IRQ_TYPE_LEVEL_HIGH>, <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>; ti,hwmods = "debugss"; }; I also looked more closely at of_pmu_irq_cfg() platform_get_irq(pdev, 0); returns -6 pdev->num_resources is 0 therefore... if (i == pdev->num_resources) { pmu->irq_affinity = irqs; } else { kfree(irqs); cpumask_setall(&pmu->supported_cpus); } pmu->irq_affinity gets set to an invalid pointer (0x00000010) and cpumask_setall() is not called. Something is not working as expected, right? Regards. ^ permalink raw reply [flat|nested] 5+ messages in thread
* pmu: armv7_a9_pmu_init() fails with -ENXIO 2015-10-21 13:46 ` Mason @ 2015-10-21 14:27 ` Sudeep Holla 2015-10-21 15:44 ` Mason 0 siblings, 1 reply; 5+ messages in thread From: Sudeep Holla @ 2015-10-21 14:27 UTC (permalink / raw) To: linux-arm-kernel On 21/10/15 14:46, Mason wrote: [...] > > I also looked more closely at of_pmu_irq_cfg() > > platform_get_irq(pdev, 0); returns -6 Won't it return here ? Though you must first check why is that returning error. irq = platform_get_irq(pdev, 0); if (irq >= 0 && irq_is_percpu(irq)) return 0; > pdev->num_resources is 0 therefore... > > if (i == pdev->num_resources) { > pmu->irq_affinity = irqs; > } else { > kfree(irqs); > cpumask_setall(&pmu->supported_cpus); > } > > pmu->irq_affinity gets set to an invalid pointer (0x00000010) > and cpumask_setall() is not called. > > Something is not working as expected, right? > So you won't execute this in that case. Sorry if I missed something, I briefly checked v4.2 Code have been changed and even moved since then. -- Regards, Sudeep ^ permalink raw reply [flat|nested] 5+ messages in thread
* pmu: armv7_a9_pmu_init() fails with -ENXIO 2015-10-21 14:27 ` Sudeep Holla @ 2015-10-21 15:44 ` Mason 2015-10-21 16:26 ` Sudeep Holla 0 siblings, 1 reply; 5+ messages in thread From: Mason @ 2015-10-21 15:44 UTC (permalink / raw) To: linux-arm-kernel On 21/10/2015 16:27, Sudeep Holla wrote: > On 21/10/15 14:46, Mason wrote: > >> I also looked more closely at of_pmu_irq_cfg() >> >> platform_get_irq(pdev, 0); returns -6 > > Won't it return here ? > Though you must first check why is that returning error. > > irq = platform_get_irq(pdev, 0); > if (irq >= 0 && irq_is_percpu(irq)) > return 0; Thanks for prodding me in the right direction. platform_get_irq() was failing because I hadn't properly defined the node's interrupt-parent... I've added interrupt-parent = <&gic>; at the root of my DT, and things now work as expected. (Haven't tested actually using the counters yet.) [ 0.090058] irq=212 irqs=e7603400 pdev->num_resources=2 [ 0.090091] hw perfevents: Failed to parse /pmu/interrupt-affinity[0] [ 0.090103] armv7_a9_pmu_init: ret=0 [ 0.090145] hw perfevents: enabled with armv7_cortex_a9 PMU driver, 7 counters available Thanks again. Regards. ^ permalink raw reply [flat|nested] 5+ messages in thread
* pmu: armv7_a9_pmu_init() fails with -ENXIO 2015-10-21 15:44 ` Mason @ 2015-10-21 16:26 ` Sudeep Holla 0 siblings, 0 replies; 5+ messages in thread From: Sudeep Holla @ 2015-10-21 16:26 UTC (permalink / raw) To: linux-arm-kernel On 21/10/15 16:44, Mason wrote: > On 21/10/2015 16:27, Sudeep Holla wrote: > >> On 21/10/15 14:46, Mason wrote: >> >>> I also looked more closely at of_pmu_irq_cfg() >>> >>> platform_get_irq(pdev, 0); returns -6 >> >> Won't it return here ? >> Though you must first check why is that returning error. >> >> irq = platform_get_irq(pdev, 0); >> if (irq >= 0 && irq_is_percpu(irq)) >> return 0; > > Thanks for prodding me in the right direction. > platform_get_irq() was failing because I hadn't properly defined > the node's interrupt-parent... > Yes that's what I guessed seeing of_irq_get. > I've added > interrupt-parent = <&gic>; > at the root of my DT, and things now work as expected. > (Haven't tested actually using the counters yet.) > > [ 0.090058] irq=212 irqs=e7603400 pdev->num_resources=2 > [ 0.090091] hw perfevents: Failed to parse /pmu/interrupt-affinity[0] Better to add this property. It assigns the cpu affinity in logical order which might break if your logical and physical cpu ordering differs.(e.g. you boot on CPU#1 instead of CPU#0) > [ 0.090103] armv7_a9_pmu_init: ret=0 > [ 0.090145] hw perfevents: enabled with armv7_cortex_a9 PMU driver, 7 counters available > Cool -- Regards, Sudeep ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-10-21 16:26 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2015-10-21 13:01 pmu: armv7_a9_pmu_init() fails with -ENXIO Mason 2015-10-21 13:46 ` Mason 2015-10-21 14:27 ` Sudeep Holla 2015-10-21 15:44 ` Mason 2015-10-21 16:26 ` Sudeep Holla
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