From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754158AbdA3T3f (ORCPT ); Mon, 30 Jan 2017 14:29:35 -0500 Received: from foss.arm.com ([217.140.101.70]:51176 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754037AbdA3T3d (ORCPT ); Mon, 30 Jan 2017 14:29:33 -0500 Date: Mon, 30 Jan 2017 13:03:12 -0600 From: Kim Phillips To: Will Deacon Cc: , , , , , , , , , , , , , Subject: Re: [PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Message-Id: <20170130130312.09e4aef34c685f4c228aba50@arm.com> In-Reply-To: <1485540470-11469-10-git-send-email-will.deacon@arm.com> References: <1485540470-11469-1-git-send-email-will.deacon@arm.com> <1485540470-11469-10-git-send-email-will.deacon@arm.com> Organization: ARM X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 27 Jan 2017 18:07:48 +0000 Will Deacon wrote: > +/* Perf callbacks */ > +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 add below messaging such as to avoid users having to do so themselves: diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c index b4906c3..7c2635c 100644 --- a/drivers/perf/arm_spe_pmu.c +++ b/drivers/perf/arm_spe_pmu.c @@ -655,24 +655,33 @@ 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); + struct device *dev = &spe_pmu->pdev->dev; /* 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)) + !cpumask_test_cpu(event->cpu, &spe_pmu->supported_cpus)) { + dev_err_ratelimited(dev, "CPU not supported by SPE\n"); return -ENOENT; + } - if (arm_spe_event_to_pmsevfr(event) & PMSEVFR_EL1_RES0) + if (arm_spe_event_to_pmsevfr(event) & PMSEVFR_EL1_RES0) { + dev_err_ratelimited(dev, "Unsupported event filter\n"); return -EOPNOTSUPP; + } if (event->hw.sample_period < spe_pmu->min_period || - event->hw.sample_period & PMSIRR_EL1_IVAL_MASK) + event->hw.sample_period & PMSIRR_EL1_IVAL_MASK) { + dev_err_ratelimited(dev, "Cannot set sample period below the minimum interval\n"); return -EOPNOTSUPP; + } - if (attr->exclude_idle) + if (attr->exclude_idle) { + dev_err_ratelimited(dev, "Cannot exclude profiling when idle\n"); return -EOPNOTSUPP; + } /* * Feedback-directed frequency throttling doesn't work when we @@ -681,28 +690,39 @@ static int arm_spe_pmu_event_init(struct perf_event *event) * count to reflect that. Instead, force the user to specify a * sample period instead. */ - if (attr->freq) + if (attr->freq) { + dev_err_ratelimited(dev, "a sample period must be specified\n"); return -EINVAL; + } if (is_kernel_in_hyp_mode()) { - if (attr->exclude_kernel != attr->exclude_hv) + if (attr->exclude_kernel != attr->exclude_hv) { + dev_err_ratelimited(dev, "VHE is enabled but exclude_kernel and exclude_hv do not match\n"); return -EOPNOTSUPP; + } } else if (!attr->exclude_hv) { + dev_err_ratelimited(dev, "VHE is disabled but exclude_hv is not set\n"); return -EOPNOTSUPP; } reg = arm_spe_event_to_pmsfcr(event); if ((reg & BIT(PMSFCR_EL1_FE_SHIFT)) && - !(spe_pmu->features & SPE_PMU_FEAT_FILT_EVT)) + !(spe_pmu->features & SPE_PMU_FEAT_FILT_EVT)) { + dev_err_ratelimited(dev, "event filter feature not supported\n"); return -EOPNOTSUPP; + } if ((reg & BIT(PMSFCR_EL1_FT_SHIFT)) && - !(spe_pmu->features & SPE_PMU_FEAT_FILT_TYP)) + !(spe_pmu->features & SPE_PMU_FEAT_FILT_TYP)) { + dev_err_ratelimited(dev, "event type filter feature not supported\n"); return -EOPNOTSUPP; + } if ((reg & BIT(PMSFCR_EL1_FL_SHIFT)) && - !(spe_pmu->features & SPE_PMU_FEAT_FILT_LAT)) + !(spe_pmu->features & SPE_PMU_FEAT_FILT_LAT)) { + dev_err_ratelimited(dev, "latency filter feature not supported\n"); return -EOPNOTSUPP; + } return 0; } Thanks, Kim