Re: [PATCH 18/23] iommu: Express DMA strictness via the domain type
From: Lu Baolu <baolu.lu@linux.intel.com>
Date: 2021-07-24 05:30:02
Also in:
linux-iommu, lkml
Hi Robin, On 2021/7/22 2:20, Robin Murphy wrote:
Eliminate the iommu_get_dma_strict() indirection and pipe the
information through the domain type from the beginning. Besides
the flow simplification this also has several nice side-effects:
- Automatically implies strict mode for untrusted devices by
virtue of their IOMMU_DOMAIN_DMA override.
- Ensures that we only ends up using flush queues for drivers
which are aware of them and can actually benefit.Is this expressed by vendor iommu driver has ops->flush_iotlb_all?
quoted hunk ↗ jump to hunk
- Allows us to handle flush queue init failure by falling back to strict mode instead of leaving it to possibly blow up later. Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +- drivers/iommu/arm/arm-smmu/arm-smmu.c | 2 +- drivers/iommu/dma-iommu.c | 10 ++++++---- drivers/iommu/iommu.c | 14 ++++---------- include/linux/iommu.h | 1 - 5 files changed, 12 insertions(+), 17 deletions(-)diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index fa41026d272e..260b560d0075 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c@@ -2175,7 +2175,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain, .iommu_dev = smmu->dev, }; - if (!iommu_get_dma_strict(domain)) + if (domain->type == IOMMU_DOMAIN_DMA_FQ) pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index dbc14c265b15..2c717f3be056 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c@@ -765,7 +765,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain, .iommu_dev = smmu->dev, }; - if (!iommu_get_dma_strict(domain)) + if (domain->type == IOMMU_DOMAIN_DMA_FQ) pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; if (smmu->impl && smmu->impl->init_context) {diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index b1af1ff324c5..a114a7ad88ec 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c@@ -363,13 +363,15 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, init_iova_domain(iovad, 1UL << order, base_pfn); - if (!cookie->fq_domain && !dev_is_untrusted(dev) && - domain->ops->flush_iotlb_all && !iommu_get_dma_strict(domain)) { + if (domain->type == IOMMU_DOMAIN_DMA_FQ && !cookie->fq_domain && + domain->ops->flush_iotlb_all) { if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, - iommu_dma_entry_dtor)) + iommu_dma_entry_dtor)) { pr_warn("iova flush queue initialization failed\n"); - else + domain->type = IOMMU_DOMAIN_DMA; + } else { cookie->fq_domain = domain; + } } return iova_reserve_iommu_regions(dev, domain);diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 8333c334891e..d7eaacae0944 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c@@ -135,6 +135,9 @@ static int __init iommu_subsys_init(void) } } + if (!iommu_default_passthrough() && !iommu_dma_strict) + iommu_def_domain_type = IOMMU_DOMAIN_DMA_FQ; + pr_info("Default domain type: %s %s\n", iommu_domain_type_str(iommu_def_domain_type), (iommu_cmd_line & IOMMU_CMD_LINE_DMA_API) ?@@ -352,15 +355,6 @@ void iommu_set_dma_strict(bool strict) iommu_dma_strict = strict; } -bool iommu_get_dma_strict(struct iommu_domain *domain) -{ - /* only allow lazy flushing for DMA domains */ - if (domain->type == IOMMU_DOMAIN_DMA) - return iommu_dma_strict; - return true; -} -EXPORT_SYMBOL_GPL(iommu_get_dma_strict); - static ssize_t iommu_group_attr_show(struct kobject *kobj, struct attribute *__attr, char *buf) {@@ -764,7 +758,7 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group, unsigned long pg_size; int ret = 0; - if (!domain || domain->type != IOMMU_DOMAIN_DMA) + if (!domain || !(domain->type & __IOMMU_DOMAIN_DMA_API))
Nit: probably move above change to patch 14?
quoted hunk ↗ jump to hunk
return 0; BUG_ON(!domain->pgsize_bitmap);diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 56519110d43f..557c4c12e2cf 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h@@ -484,7 +484,6 @@ int iommu_set_pgtable_quirks(struct iommu_domain *domain, unsigned long quirks); void iommu_set_dma_strict(bool val); -bool iommu_get_dma_strict(struct iommu_domain *domain); extern int report_iommu_fault(struct iommu_domain *domain, struct device *dev, unsigned long iova, int flags);
Best regards, baolu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel