On Fri, 13 Jan 2017 16:03:48 +0000 Will Deacon <will.dea...@arm.com> wrote:
> +#define DRVNAME "arm_spe_pmu" PMU is implied. "arm_spe"? > +static int arm_spe_pmu_event_init(struct perf_event *event) > +{ > + u64 reg; > + struct perf_event_attr *attr = &event->attr; > + struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu); > + > + /* This is, of course, deeply driver-specific */ > + if (attr->type != event->pmu->type) > + return -ENOENT; > + > + if (event->cpu >= 0 && > + !cpumask_test_cpu(event->cpu, &spe_pmu->supported_cpus)) > + return -ENOENT; > + > + if (arm_spe_event_to_pmsevfr(event) & PMSEVFR_EL1_RES0) > + return -EOPNOTSUPP; > + > + if (event->hw.sample_period < spe_pmu->min_period || > + event->hw.sample_period & PMSIRR_EL1_IVAL_MASK) > + return -EOPNOTSUPP; > + > + if (attr->exclude_idle) > + return -EOPNOTSUPP; > + > + /* > + * Feedback-directed frequency throttling doesn't work when we > + * have a buffer of samples. We'd need to manually count the > + * samples in the buffer when it fills up and adjust the event > + * count to reflect that. Instead, force the user to specify a > + * sample period instead. > + */ > + if (attr->freq) > + return -EINVAL; > + > + if (is_kernel_in_hyp_mode()) { > + if (attr->exclude_kernel != attr->exclude_hv) > + return -EOPNOTSUPP; > + } else if (!attr->exclude_hv) { > + return -EOPNOTSUPP; > + } > + > + reg = arm_spe_event_to_pmsfcr(event); > + if ((reg & BIT(PMSFCR_EL1_FE_SHIFT)) && > + !(spe_pmu->features & SPE_PMU_FEAT_FILT_EVT)) > + return -EOPNOTSUPP; > + > + if ((reg & BIT(PMSFCR_EL1_FT_SHIFT)) && > + !(spe_pmu->features & SPE_PMU_FEAT_FILT_TYP)) > + return -EOPNOTSUPP; > + > + if ((reg & BIT(PMSFCR_EL1_FL_SHIFT)) && > + !(spe_pmu->features & SPE_PMU_FEAT_FILT_LAT)) > + return -EOPNOTSUPP; > + > + return 0; > +} Please insert pr_* statements before blindly returning errors before a better facility becomes available. Thanks, Kim