[PATCH v7 5/6] iommu/arm-smmu-v3: Add support for non-strict mode
From: Will Deacon <hidden>
Date: 2018-09-18 17:10:00
Also in:
linux-iommu, lkml
On Fri, Sep 14, 2018 at 03:30:23PM +0100, Robin Murphy wrote:
From: Zhen Lei <redacted> Dynamically choose strict or non-strict mode for page table config based on the iommu domain type.
It's the domain type in conjunction with the attribute that determines whether we use lazy or strict invalidation.
quoted hunk ↗ jump to hunk
Signed-off-by: Zhen Lei <redacted> [rm: convert to domain attribute] Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/arm-smmu-v3.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-)diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index f10c852479fc..7bbfa5f7ce8e 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 {@@ -1633,6 +1634,9 @@ 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;@@ -1934,13 +1938,17 @@ 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: + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -EINVAL; *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED); return 0; + case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE: + if (domain->type != IOMMU_DOMAIN_DMA) + return -EINVAL; + *(int *)data = smmu_domain->non_strict; + return 0; default: return -ENODEV;
Hmm, there's a change in behaviour here (and also in the set function) which is that unknown attributes now return -ENODEV for managed domains instead of -EINVAL. I don't know if that's a problem, but I'd be inclined to switch on the domain type and then have a nested switch for the supported attributes. Will