On 2021-08-11 11:30, Will Deacon wrote:
On Wed, Aug 11, 2021 at 11:37:25AM +0530, Sai Prakash Ranjan wrote:diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index f7da8953afbe..3904b598e0f9 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -327,9 +327,16 @@ static void arm_smmu_tlb_inv_range_s2(unsigned long iova, size_t size, static void arm_smmu_tlb_inv_walk_s1(unsigned long iova, size_t size, size_t granule, void *cookie) { - arm_smmu_tlb_inv_range_s1(iova, size, granule, cookie, - ARM_SMMU_CB_S1_TLBIVA); - arm_smmu_tlb_sync_context(cookie); + struct arm_smmu_domain *smmu_domain = cookie; + struct arm_smmu_cfg *cfg = &smmu_domain->cfg; + + if (cfg->flush_walk_prefer_tlbiasid) { + arm_smmu_tlb_inv_context_s1(cookie);Hmm, this introduces an unconditional wmb() if tlbiasid is preferred. I think that should be predicated on ARM_SMMU_FEAT_COHERENT_WALK like it is for the by-VA ops. Worth doing as a separate patch.+ } else { + arm_smmu_tlb_inv_range_s1(iova, size, granule, cookie, + ARM_SMMU_CB_S1_TLBIVA); + arm_smmu_tlb_sync_context(cookie); + } }static void arm_smmu_tlb_add_page_s1(struct iommu_iotlb_gather *gather,@@ -765,8 +772,10 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain, .iommu_dev = smmu->dev, };- if (!iommu_get_dma_strict(domain))+ if (!iommu_get_dma_strict(domain)) { pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; + cfg->flush_walk_prefer_tlbiasid = true;This is going to interact badly with Robin's series to allow dynamic transition to non-strict mode, as we don't have a mechanism to switch over to the by-ASID behaviour. Yes, it should _work_, but it's ugly having different TLBI behaviour just because of the how the domain became non-strict. Robin -- I think this originated from your idea at [1]. Any idea how to make it work with your other series, or shall we drop this part for now and leave the TLB invalidation behaviour the same for now?
Yeah, I'd say drop it - I'm currently half an hour into a first attempt at removing io_pgtable_tlb_flush_walk() entirely, which would make it moot for non-strict anyway.
Robin. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
