Messages in this thread Patch in this message | | | Subject | Re: [PATCH v3 1/4] iommu/arm-smmu: Add SMMU ID2 register fixup hook | From | Robin Murphy <> | Date | Fri, 3 Jul 2020 09:24:24 +0100 |
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On 2020-07-02 21:16, Tomasz Nowicki wrote: > We already have 'cfg_probe' hook which meant to override and apply > workarounds while probing ID registers. However, 'cfg_probe' is called > at the very end and therefore for some cases fixing up things becomes complex > or requires exporting of SMMU driver structures. Hence, seems it is better and > cleaner to do ID fixup right away. In preparation for adding Marvell > errata add an extra ID2 fixup hook.
Hmm, the intent of ->cfg_probe was very much to give impl a chance to adjust the detected features before we start consuming them, with this exact case in mind. Since the Cavium quirk isn't actually doing that - it just needs to run *anywhere* in the whole probe process - I'm under no illusion that I put the hook in exactly the right place first time around ;)
The diff below should be more on the mark...
Robin.
----->8----- diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 243bc4cb2705..884ffca5b1eb 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1891,6 +1891,9 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) smmu->features |= ARM_SMMU_FEAT_FMT_AARCH64_64K; }
+ if (smmu->impl && smmu->impl->cfg_probe) + return smmu->impl->cfg_probe(smmu); + /* Now we've corralled the various formats, what'll it do? */ if (smmu->features & ARM_SMMU_FEAT_FMT_AARCH32_S) smmu->pgsize_bitmap |= SZ_4K | SZ_64K | SZ_1M | SZ_16M; @@ -1909,7 +1912,6 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) dev_notice(smmu->dev, "\tSupported page sizes: 0x%08lx\n", smmu->pgsize_bitmap);
- if (smmu->features & ARM_SMMU_FEAT_TRANS_S1) dev_notice(smmu->dev, "\tStage-1: %lu-bit VA -> %lu-bit IPA\n", smmu->va_size, smmu->ipa_size); @@ -1918,9 +1920,6 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) dev_notice(smmu->dev, "\tStage-2: %lu-bit IPA -> %lu-bit PA\n", smmu->ipa_size, smmu->pa_size);
- if (smmu->impl && smmu->impl->cfg_probe) - return smmu->impl->cfg_probe(smmu); - return 0; }
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