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.anders...@linaro.org>
---
Changes since RFC:
- Deal with EXIDS
- Use arm_smmu_gr0_read/write()
drivers/iommu/arm-smmu.c | 27 +++++++++++++++++++++++----
1 file changed, 23 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 4f1a350d9529..6ca6a4e072c8 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -945,24 +945,43 @@ static void arm_smmu_write_sme(struct arm_smmu_device
*smmu, int idx)
*/
static void arm_smmu_test_smr_masks(struct arm_smmu_device *smmu)
{
+ u32 s2cr;
u32 smr;
+ int idx;
if (!smmu->smrs)
return;
+ for (idx = 0; idx < smmu->num_mapping_groups; idx++) {
+ if (smmu->features & ARM_SMMU_FEAT_EXIDS) {
+ s2cr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_S2CR(idx));
+ if (!FIELD_GET(S2CR_EXIDVALID, s2cr))
+ break;
+ } else {
+ smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(idx));
+ if (!FIELD_GET(SMR_VALID, smr))
+ 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 = FIELD_PREP(SMR_ID, smmu->streamid_mask);
- arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_SMR(0), smr);
- smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(0));
+ arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_SMR(idx), smr);
+ smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(idx));
smmu->streamid_mask = FIELD_GET(SMR_ID, smr);
smr = FIELD_PREP(SMR_MASK, smmu->streamid_mask);
- arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_SMR(0), smr);
- smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(0));
+ arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_SMR(idx), smr);
+ smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(idx));
smmu->smr_mask_mask = FIELD_GET(SMR_MASK, smr);
}
--
2.24.0
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