| Message ID | 20190605210856.20677-3-bjorn.andersson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,1/2] iommu: arm-smmu: Handoff SMR registers and context banks | expand |
On Wed, Jun 5, 2019 at 3:09 PM Bjorn Andersson <bjorn.andersson@linaro.org> wrote: > > With the SMRs inherited from the bootloader the first SMR might actually > be valid and in use. As such probing the SMR mask using the first SMR > might break a stream in use. Search for an unused stream and use this to > probe the SMR mask. > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> I don't quite like the situation where the is no SMR to compute the mask, but I think the way you've handled it is the best option/ I'm curious, why is this not included in patch #1? Seems like patch #1 introduces the issue, yet doesn't also fix it. > --- > drivers/iommu/arm-smmu.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index c8629a656b42..0c6f5fe6f382 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -1084,23 +1084,35 @@ static void arm_smmu_test_smr_masks(struct arm_smmu_device *smmu) > { > void __iomem *gr0_base = ARM_SMMU_GR0(smmu); > u32 smr; > + int idx; > > if (!smmu->smrs) > return; > > + for (idx = 0; idx < smmu->num_mapping_groups; idx++) { > + smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx)); > + if (!(smr & SMR_VALID)) > + break; > + } > + > + if (idx == smmu->num_mapping_groups) { > + dev_err(smmu->dev, "Unable to compute streamid_mask\n"); > + return; > + } > + > /* > * SMR.ID bits may not be preserved if the corresponding MASK > * bits are set, so check each one separately. We can reject > * masters later if they try to claim IDs outside these masks. > */ > smr = smmu->streamid_mask << SMR_ID_SHIFT; > - writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0)); > - smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0)); > + writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(idx)); > + smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx)); > smmu->streamid_mask = smr >> SMR_ID_SHIFT; > > smr = smmu->streamid_mask << SMR_MASK_SHIFT; > - writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0)); > - smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0)); > + writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(idx)); > + smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx)); > smmu->smr_mask_mask = smr >> SMR_MASK_SHIFT; > } > > -- > 2.18.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index c8629a656b42..0c6f5fe6f382 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1084,23 +1084,35 @@ static void arm_smmu_test_smr_masks(struct arm_smmu_device *smmu) { void __iomem *gr0_base = ARM_SMMU_GR0(smmu); u32 smr; + int idx; if (!smmu->smrs) return; + for (idx = 0; idx < smmu->num_mapping_groups; idx++) { + smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx)); + if (!(smr & SMR_VALID)) + break; + } + + if (idx == smmu->num_mapping_groups) { + dev_err(smmu->dev, "Unable to compute streamid_mask\n"); + return; + } + /* * SMR.ID bits may not be preserved if the corresponding MASK * bits are set, so check each one separately. We can reject * masters later if they try to claim IDs outside these masks. */ smr = smmu->streamid_mask << SMR_ID_SHIFT; - writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0)); - smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0)); + writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(idx)); + smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx)); smmu->streamid_mask = smr >> SMR_ID_SHIFT; smr = smmu->streamid_mask << SMR_MASK_SHIFT; - writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0)); - smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0)); + writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(idx)); + smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx)); smmu->smr_mask_mask = smr >> SMR_MASK_SHIFT; }
With the SMRs inherited from the bootloader the first SMR might actually be valid and in use. As such probing the SMR mask using the first SMR might break a stream in use. Search for an unused stream and use this to probe the SMR mask. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> --- drivers/iommu/arm-smmu.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) -- 2.18.0