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authorRobin Murphy <robin.murphy@arm.com>2021-08-11 13:21:34 +0100
committerJoerg Roedel <jroedel@suse.de>2021-08-18 13:27:49 +0200
commitc208916fe6c7b84e3ec95cd91853039596eeb2cf (patch)
tree735bb051c9c011787d0e9f34c0a6f9ce1d89b67d /drivers/iommu
parent78ca078459d779319a22a8e2a18fc491da8a229b (diff)
downloadlinux-c208916fe6c7b84e3ec95cd91853039596eeb2cf.tar.bz2
iommu: Express DMA strictness via the domain type
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.lu@linux.intel.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/47083d69155577f1367877b1594921948c366eb3.1628682049.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/dma-iommu.c10
-rw-r--r--drivers/iommu/iommu.c14
2 files changed, 11 insertions, 13 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 17ac3dd4f23e..b7ae855c1e89 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -370,13 +370,15 @@ 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 the FQ fails we can simply fall back to strict mode */
+ 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 17d6728f5a09..e09f0d433683 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)
{