> -----Original Message----- > From: Robin Murphy [mailto:robin.murphy@xxxxxxx] > Sent: 10 September 2018 12:15 > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>; > lorenzo.pieralisi@xxxxxxx > Cc: will.deacon@xxxxxxx; mark.rutland@xxxxxxx; Guohanjun (Hanjun Guo) > <guohanjun@xxxxxxxxxx>; John Garry <john.garry@xxxxxxxxxx>; > pabba@xxxxxxxxxxxxxx; vkilari@xxxxxxxxxxxxxx; rruigrok@xxxxxxxxxxxxxx; > linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; Linuxarm <linuxarm@xxxxxxxxxx>; > neil.m.leeder@xxxxxxxxx > Subject: Re: [PATCH v2 4/4] perf/smmuv3: Add MSI irq support > > On 2018-07-24 12:45 PM, Shameer Kolothum wrote: > > This adds support for MSI based counter overflow interrupt. > > > > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> > > --- > > drivers/perf/arm_smmuv3_pmu.c | 105 > +++++++++++++++++++++++++++++++++--------- > > 1 file changed, 84 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/perf/arm_smmuv3_pmu.c > b/drivers/perf/arm_smmuv3_pmu.c > > index b3dc394..ca69813 100644 > > --- a/drivers/perf/arm_smmuv3_pmu.c > > +++ b/drivers/perf/arm_smmuv3_pmu.c > > @@ -94,6 +94,10 @@ > > #define SMMU_PMCG_IRQ_CFG2 0xE64 > > #define SMMU_PMCG_IRQ_STATUS 0xE68 > > > > +/* MSI config fields */ > > +#define MSI_CFG0_ADDR_MASK GENMASK_ULL(51, 2) > > +#define MSI_CFG2_MEMATTR_DEVICE_nGnRE 0x1 > > + > > #define SMMU_COUNTER_RELOAD BIT(31) > > #define SMMU_DEFAULT_FILTER_SEC 0 > > #define SMMU_DEFAULT_FILTER_SPAN 1 > > @@ -657,14 +661,89 @@ static irqreturn_t smmu_pmu_handle_irq(int > irq_num, void *data) > > return IRQ_HANDLED; > > } > > > > +static void smmu_pmu_free_msis(void *data) > > +{ > > + struct device *dev = data; > > + > > + platform_msi_domain_free_irqs(dev); > > +} > > + > > +static void smmu_pmu_write_msi_msg(struct msi_desc *desc, struct > msi_msg *msg) > > +{ > > + phys_addr_t doorbell; > > + struct device *dev = msi_desc_to_dev(desc); > > + struct smmu_pmu *pmu = dev_get_drvdata(dev); > > + > > + doorbell = (((u64)msg->address_hi) << 32) | msg->address_lo; > > + doorbell &= MSI_CFG0_ADDR_MASK; > > + > > + writeq_relaxed(doorbell, pmu->reg_base + SMMU_PMCG_IRQ_CFG0); > > + writel_relaxed(msg->data, pmu->reg_base + > SMMU_PMCG_IRQ_CFG1); > > + writel_relaxed(MSI_CFG2_MEMATTR_DEVICE_nGnRE, > > + pmu->reg_base + SMMU_PMCG_IRQ_CFG2); > > +} > > + > > +static void smmu_pmu_setup_msi(struct smmu_pmu *pmu) > > +{ > > + struct msi_desc *desc; > > + struct device *dev = pmu->dev; > > + int ret; > > + > > + /* Clear MSI address reg */ > > + writeq_relaxed(0, pmu->reg_base + SMMU_PMCG_IRQ_CFG0); > > + > > + /* MSI supported or not */ > > + if (!(readl(pmu->reg_base + SMMU_PMCG_CFGR) & > SMMU_PMCG_CFGR_MSI)) > > + return; > > + > > + ret = platform_msi_domain_alloc_irqs(dev, 1, > smmu_pmu_write_msi_msg); > > + if (ret) { > > + dev_warn(dev, "failed to allocate MSIs\n"); > > + return; > > + } > > + > > + desc = first_msi_entry(dev); > > + if (desc) > > + pmu->irq = desc->irq; > > + > > + /* Add callback to free MSIs on teardown */ > > + devm_add_action(dev, smmu_pmu_free_msis, dev); > > +} > > + > > +static int smmu_pmu_setup_irq(struct smmu_pmu *pmu) > > +{ > > + int irq, ret = -ENXIO; > > + > > + smmu_pmu_setup_msi(pmu); > > + > > + irq = pmu->irq; > > + if (irq) > > + ret = devm_request_irq(pmu->dev, irq, > smmu_pmu_handle_irq, > > + IRQF_NOBALANCING | IRQF_SHARED | > IRQF_NO_THREAD, > > + "smmu-v3-pmu", pmu); > > + return ret; > > +} > > + > > static int smmu_pmu_reset(struct smmu_pmu *smmu_pmu) > > { > > + int ret; > > + > > /* Disable counter and interrupt */ > > writeq(smmu_pmu->counter_present_mask, > > smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0); > > writeq(smmu_pmu->counter_present_mask, > > smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0); > > > > + ret = smmu_pmu_setup_irq(smmu_pmu); > > Why are we moving this out of probe? We may perform a reset more than > once (e.g. if we get round to system PM support), at which point this > looks logically wrong. I didn’t consider that scenario. I will modify this in next. Thanks, Shameer > Robin. > > > + if (ret) { > > + dev_err(smmu_pmu->dev, "failed to setup irqs\n"); > > + return ret; > > + } > > + > > + /* Pick one CPU to be the preferred one to use */ > > + smmu_pmu->on_cpu = smp_processor_id(); > > + WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu- > >on_cpu))); > > + > > smmu_pmu_disable(&smmu_pmu->pmu); > > return 0; > > } > > @@ -738,26 +817,8 @@ static int smmu_pmu_probe(struct platform_device > *pdev) > > } > > > > irq = platform_get_irq(pdev, 0); > > - if (irq < 0) { > > - dev_err(dev, "Failed to get valid irq for smmu @%pa\n", > > - &mem_resource_0->start); > > - return irq; > > - } > > - > > - err = devm_request_irq(dev, irq, smmu_pmu_handle_irq, > > - IRQF_NOBALANCING | IRQF_SHARED | > IRQF_NO_THREAD, > > - "smmu-pmu", smmu_pmu); > > - if (err) { > > - dev_err(dev, > > - "Unable to request IRQ%d for SMMU PMU > counters\n", irq); > > - return err; > > - } > > - > > - smmu_pmu->irq = irq; > > - > > - /* Pick one CPU to be the preferred one to use */ > > - smmu_pmu->on_cpu = smp_processor_id(); > > - WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu- > >on_cpu))); > > + if (irq > 0) > > + smmu_pmu->irq = irq; > > > > smmu_pmu->num_counters = get_num_counters(smmu_pmu); > > smmu_pmu->counter_present_mask = GENMASK(smmu_pmu- > >num_counters - 1, 0); > > @@ -765,7 +826,9 @@ static int smmu_pmu_probe(struct platform_device > *pdev) > > SMMU_PMCG_CFGR_SIZE_MASK) >> > SMMU_PMCG_CFGR_SIZE_SHIFT; > > smmu_pmu->counter_mask = GENMASK_ULL(reg_size, 0); > > > > - smmu_pmu_reset(smmu_pmu); > > + err = smmu_pmu_reset(smmu_pmu); > > + if (err) > > + return err; > > > > err = cpuhp_state_add_instance_nocalls(cpuhp_state_num, > > &smmu_pmu->node); > >
