Hi, Robin: Can you review this patch again?
On 2021/1/30 15:14, Zhen Lei wrote: > According to the SMMUv3 specification: > Each PMCG counter group is represented by one 4KB page (Page 0) with one > optional additional 4KB page (Page 1), both of which are at IMPLEMENTATION > DEFINED base addresses. > > This means that the PMCG register spaces may be within the 64KB pages of > the SMMUv3 register space. When both the SMMU and PMCG drivers reserve > their own resources, a resource conflict occurs. > > To avoid this conflict, don't reserve the PMCG regions. > > Suggested-by: Robin Murphy <robin.mur...@arm.com> > Signed-off-by: Zhen Lei <thunder.leiz...@huawei.com> > --- > drivers/perf/arm_smmuv3_pmu.c | 25 +++++++++++++++++++------ > 1 file changed, 19 insertions(+), 6 deletions(-) > > diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c > index 74474bb322c3f26..5e894f957c7b935 100644 > --- a/drivers/perf/arm_smmuv3_pmu.c > +++ b/drivers/perf/arm_smmuv3_pmu.c > @@ -793,17 +793,30 @@ static int smmu_pmu_probe(struct platform_device *pdev) > .capabilities = PERF_PMU_CAP_NO_EXCLUDE, > }; > > - smmu_pmu->reg_base = devm_platform_get_and_ioremap_resource(pdev, 0, > &res_0); > - if (IS_ERR(smmu_pmu->reg_base)) > - return PTR_ERR(smmu_pmu->reg_base); > + /* > + * The register spaces of the PMCG may be in the register space of > + * other devices. For example, SMMU. Therefore, the PMCG resources are > + * not reserved to avoid resource conflicts with other drivers. > + */ > + res_0 = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res_0) > + return ERR_PTR(-EINVAL); > + smmu_pmu->reg_base = devm_ioremap(dev, res_0->start, > resource_size(res_0)); > + if (!smmu_pmu->reg_base) > + return ERR_PTR(-ENOMEM); > > cfgr = readl_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CFGR); > > /* Determine if page 1 is present */ > if (cfgr & SMMU_PMCG_CFGR_RELOC_CTRS) { > - smmu_pmu->reloc_base = devm_platform_ioremap_resource(pdev, 1); > - if (IS_ERR(smmu_pmu->reloc_base)) > - return PTR_ERR(smmu_pmu->reloc_base); > + struct resource *res_1; > + > + res_1 = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + if (!res_1) > + return ERR_PTR(-EINVAL); > + smmu_pmu->reloc_base = devm_ioremap(dev, res_1->start, > resource_size(res_1)); > + if (!smmu_pmu->reloc_base) > + return ERR_PTR(-ENOMEM); > } else { > smmu_pmu->reloc_base = smmu_pmu->reg_base; > } >