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 end up using flush queues for drivers
which are aware of them and can actually benefit.
- Allows us to handle flush queue init failure by falling back
to strict mode instead of leaving it to possibly blow up later.
Reviewed-by: Lu Baolu <baolu...@linux.intel.com>
Signed-off-by: Robin Murphy <robin.mur...@arm.com>
---
v3: Remember to update iommu_def_domain_type accordingly from
iommu_set_dma_strict() too
---
drivers/iommu/dma-iommu.c | 9 +++++----
drivers/iommu/iommu.c | 14 +++++---------
include/linux/iommu.h | 1 -
3 files changed, 10 insertions(+), 14 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 207c8febdac9..2e19505dddf9 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -363,13 +363,14 @@ 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) {
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 982545234cf3..55ca5bf3cafc 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -136,6 +136,9 @@ 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) ?
@@ -355,17 +358,10 @@ early_param("iommu.strict", iommu_dma_setup);
void iommu_set_dma_strict(void)
{
iommu_dma_strict = true;
+ if (iommu_def_domain_type == IOMMU_DOMAIN_DMA_FQ)
+ iommu_def_domain_type = IOMMU_DOMAIN_DMA;
}
-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)
{
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 5629ae42951f..923a8d1c5e39 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -504,7 +504,6 @@ int iommu_set_pgtable_quirks(struct iommu_domain *domain,
unsigned long quirks);
void iommu_set_dma_strict(void);
-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);
--
2.25.1
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