| Message ID | 1471985280-2243-8-git-send-email-jeremy.linton@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Jeremy Linton <jeremy.linton@arm.com> writes: > On systems with multiple PMU types the PMU to CPU affinity > needs to be detected and set. The CPU to interrupt affinity > should also be set. > > Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> > --- > drivers/perf/arm_pmu.c | 53 ++++++++++++++++++++++++++++++++++++++++---------- > 1 file changed, 43 insertions(+), 10 deletions(-) > > diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c > index f1aee26..ee9e301 100644 > --- a/drivers/perf/arm_pmu.c > +++ b/drivers/perf/arm_pmu.c [...] > @@ -876,25 +878,57 @@ static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu) > } > > /* > - * CPU PMU identification and probing. > + * CPU PMU identification and probing. Its possible to have > + * multiple CPU types in an ARM machine. Assure that we are > + * picking the right PMU types based on the CPU in question > */ > -static int probe_current_pmu(struct arm_pmu *pmu, > - const struct pmu_probe_info *info) > +static int probe_plat_pmu(struct arm_pmu *pmu, > + const struct pmu_probe_info *info, > + unsigned int pmuid) > { > - int cpu = get_cpu(); > - unsigned int cpuid = read_cpuid_id(); > int ret = -ENODEV; > + int cpu; > + int aff_ctr = 0; > + static int duplicate_pmus; > + struct platform_device *pdev = pmu->plat_device; > + int irq = platform_get_irq(pdev, 0); > + > + if (irq >= 0 && !irq_is_percpu(irq)) { > + pmu->irq_affinity = kcalloc(pdev->num_resources, sizeof(int), > + GFP_KERNEL); > + if (!pmu->irq_affinity) > + return -ENOMEM; > + } > > - pr_info("probing PMU on CPU %d\n", cpu); > + for_each_possible_cpu(cpu) { > + unsigned int cpuid = read_specific_cpuid(cpu); > > + if (cpuid == pmuid) { > + cpumask_set_cpu(cpu, &pmu->supported_cpus); > + if (pmu->irq_affinity) { > + pmu->irq_affinity[aff_ctr] = cpu; > + aff_ctr++; > + } > + } > + } > + > + /* find the type of PMU given the CPU */ > for (; info->init != NULL; info++) { > - if ((cpuid & info->mask) != info->cpuid) > + if ((pmuid & info->mask) != info->cpuid) > continue; > ret = info->init(pmu); > + if ((!info->cpuid) && (duplicate_pmus)) { It's not obvious what the condition "!info->cpuid" implies. Please add a comment explaining the rationale. Also, the parenthesis around the two parts of the logical operation can be dropped. > + pmu->name = kasprintf(GFP_KERNEL, "%s_%d", > + pmu->name, duplicate_pmus); > + if (!pmu->name) { > + kfree(pmu->irq_affinity); > + ret = -ENOMEM; > + } > + } > + duplicate_pmus++; > break; > } > > - put_cpu(); > return ret; > } > [...]
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index f1aee26..ee9e301 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -11,6 +11,7 @@ */ #define pr_fmt(fmt) "hw perfevents: " fmt +#include <linux/acpi.h> #include <linux/bitmap.h> #include <linux/cpumask.h> #include <linux/cpu_pm.h> @@ -24,6 +25,7 @@ #include <linux/irq.h> #include <linux/irqdesc.h> +#include <asm/cpu.h> #include <asm/cputype.h> #include <asm/irq_regs.h> @@ -876,25 +878,57 @@ static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu) } /* - * CPU PMU identification and probing. + * CPU PMU identification and probing. Its possible to have + * multiple CPU types in an ARM machine. Assure that we are + * picking the right PMU types based on the CPU in question */ -static int probe_current_pmu(struct arm_pmu *pmu, - const struct pmu_probe_info *info) +static int probe_plat_pmu(struct arm_pmu *pmu, + const struct pmu_probe_info *info, + unsigned int pmuid) { - int cpu = get_cpu(); - unsigned int cpuid = read_cpuid_id(); int ret = -ENODEV; + int cpu; + int aff_ctr = 0; + static int duplicate_pmus; + struct platform_device *pdev = pmu->plat_device; + int irq = platform_get_irq(pdev, 0); + + if (irq >= 0 && !irq_is_percpu(irq)) { + pmu->irq_affinity = kcalloc(pdev->num_resources, sizeof(int), + GFP_KERNEL); + if (!pmu->irq_affinity) + return -ENOMEM; + } - pr_info("probing PMU on CPU %d\n", cpu); + for_each_possible_cpu(cpu) { + unsigned int cpuid = read_specific_cpuid(cpu); + if (cpuid == pmuid) { + cpumask_set_cpu(cpu, &pmu->supported_cpus); + if (pmu->irq_affinity) { + pmu->irq_affinity[aff_ctr] = cpu; + aff_ctr++; + } + } + } + + /* find the type of PMU given the CPU */ for (; info->init != NULL; info++) { - if ((cpuid & info->mask) != info->cpuid) + if ((pmuid & info->mask) != info->cpuid) continue; ret = info->init(pmu); + if ((!info->cpuid) && (duplicate_pmus)) { + pmu->name = kasprintf(GFP_KERNEL, "%s_%d", + pmu->name, duplicate_pmus); + if (!pmu->name) { + kfree(pmu->irq_affinity); + ret = -ENOMEM; + } + } + duplicate_pmus++; break; } - put_cpu(); return ret; } @@ -1029,8 +1063,7 @@ int arm_pmu_device_probe(struct platform_device *pdev, if (!ret) ret = init_fn(pmu); } else if (probe_table) { - cpumask_setall(&pmu->supported_cpus); - ret = probe_current_pmu(pmu, probe_table); + ret = probe_plat_pmu(pmu, probe_table, read_cpuid_id()); } if (ret) {
On systems with multiple PMU types the PMU to CPU affinity needs to be detected and set. The CPU to interrupt affinity should also be set. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> --- drivers/perf/arm_pmu.c | 53 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 43 insertions(+), 10 deletions(-)