From 9662b99a19abccb0b7bfc91abb3fec1447c35bf0 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Thu, 20 Sep 2018 17:10:25 +0100 Subject: [PATCH] iommu/arm-smmu-v3: Add support for non-strict mode Now that io-pgtable knows how to dodge strict TLB maintenance, all that's left to do is bridge the gap between the IOMMU core requesting DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE for default domains, and showing the appropriate IO_PGTABLE_QUIRK_NON_STRICT flag to alloc_io_pgtable_ops(). Signed-off-by: Zhen Lei [rm: convert to domain attribute, tweak commit message] Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- drivers/iommu/arm-smmu-v3.c | 79 ++++++++++++++++++++++++++++++++------------- 1 file changed, 56 insertions(+), 23 deletions(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index f10c852..db402e8 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -612,6 +612,7 @@ struct arm_smmu_domain { struct mutex init_mutex; /* Protects smmu pointer */ struct io_pgtable_ops *pgtbl_ops; + bool non_strict; enum arm_smmu_domain_stage stage; union { @@ -1407,6 +1408,12 @@ static void arm_smmu_tlb_inv_context(void *cookie) cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid; } + /* + * NOTE: when io-pgtable is in non-strict mode, we may get here with + * PTEs previously cleared by unmaps on the current CPU not yet visible + * to the SMMU. We are relying on the DSB implicit in queue_inc_prod() + * to guarantee those are observed before the TLBI. Do be careful, 007. + */ arm_smmu_cmdq_issue_cmd(smmu, &cmd); __arm_smmu_tlb_sync(smmu); } @@ -1633,6 +1640,9 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain) if (smmu->features & ARM_SMMU_FEAT_COHERENCY) pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA; + if (smmu_domain->non_strict) + pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; + pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain); if (!pgtbl_ops) return -ENOMEM; @@ -1934,15 +1944,27 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain, { struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); - if (domain->type != IOMMU_DOMAIN_UNMANAGED) - return -EINVAL; - - switch (attr) { - case DOMAIN_ATTR_NESTING: - *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED); - return 0; + switch (domain->type) { + case IOMMU_DOMAIN_UNMANAGED: + switch (attr) { + case DOMAIN_ATTR_NESTING: + *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED); + return 0; + default: + return -ENODEV; + } + break; + case IOMMU_DOMAIN_DMA: + switch (attr) { + case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE: + *(int *)data = smmu_domain->non_strict; + return 0; + default: + return -ENODEV; + } + break; default: - return -ENODEV; + return -EINVAL; } } @@ -1952,26 +1974,37 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain, int ret = 0; struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); - if (domain->type != IOMMU_DOMAIN_UNMANAGED) - return -EINVAL; - mutex_lock(&smmu_domain->init_mutex); - switch (attr) { - case DOMAIN_ATTR_NESTING: - if (smmu_domain->smmu) { - ret = -EPERM; - goto out_unlock; + switch (domain->type) { + case IOMMU_DOMAIN_UNMANAGED: + switch (attr) { + case DOMAIN_ATTR_NESTING: + if (smmu_domain->smmu) { + ret = -EPERM; + goto out_unlock; + } + + if (*(int *)data) + smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED; + else + smmu_domain->stage = ARM_SMMU_DOMAIN_S1; + break; + default: + ret = -ENODEV; + } + break; + case IOMMU_DOMAIN_DMA: + switch(attr) { + case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE: + smmu_domain->non_strict = *(int *)data; + break; + default: + ret = -ENODEV; } - - if (*(int *)data) - smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED; - else - smmu_domain->stage = ARM_SMMU_DOMAIN_S1; - break; default: - ret = -ENODEV; + ret = -EINVAL; } out_unlock: -- 2.7.4