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 <[email protected]> --- 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 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
