With the IOMMU core now taking care of default domains for groups
regardless of bus type, we can gleefully rip out this stop-gap, as
slight recompense for having to expand the other one.
CC: Catalin Marinas <catalin.marinas@xxxxxxx>
CC: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
arch/arm64/mm/dma-mapping.c | 52 +++++++--------------------------------------
1 file changed, 8 insertions(+), 44 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 607e709..fd8b942 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -804,57 +804,24 @@ struct iommu_dma_notifier_data {
static LIST_HEAD(iommu_dma_masters);
static DEFINE_MUTEX(iommu_dma_notifier_lock);
-/*
- * Temporarily "borrow" a domain feature flag to to tell if we had to resort
- * to creating our own domain here, in case we need to clean it up again.
- */
-#define __IOMMU_DOMAIN_FAKE_DEFAULT (1U << 31)
-
static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,
u64 dma_base, u64 size)
{
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
/*
- * Best case: The device is either part of a group which was
- * already attached to a domain in a previous call, or it's
- * been put in a default DMA domain by the IOMMU core.
+ * If the IOMMU driver has the DMA domain support that we require,
+ * then the IOMMU core will have already configured a group for this
+ * device, and allocated the default domain for that group.
*/
- if (!domain) {
- /*
- * Urgh. The IOMMU core isn't going to do default domains
- * for non-PCI devices anyway, until it has some means of
- * abstracting the entirely implementation-specific
- * sideband data/SoC topology/unicorn dust that may or
- * may not differentiate upstream masters.
- * So until then, HORRIBLE HACKS!
- */
- domain = ops->domain_alloc(IOMMU_DOMAIN_DMA);
- if (!domain)
- goto out_no_domain;
-
- domain->ops = ops;
- domain->type = IOMMU_DOMAIN_DMA | __IOMMU_DOMAIN_FAKE_DEFAULT;
-
- if (iommu_attach_device(domain, dev))
- goto out_put_domain;
+ if (!domain || iommu_dma_init_domain(domain, dma_base, size)) {
+ pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
+ dev_name(dev));
+ return false;
}
- if (iommu_dma_init_domain(domain, dma_base, size))
- goto out_detach;
-
dev->archdata.dma_ops = &iommu_dma_ops;
return true;
-
-out_detach:
- iommu_detach_device(domain, dev);
-out_put_domain:
- if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT)
- iommu_domain_free(domain);
-out_no_domain:
- pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
- dev_name(dev));
- return false;
}
static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops,
@@ -971,11 +938,8 @@ void arch_teardown_dma_ops(struct device *dev)
{
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
- if (domain) {
+ if (WARN_ON(domain))
iommu_detach_device(domain, dev);
- if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT)
- iommu_domain_free(domain);
- }
dev->archdata.dma_ops = NULL;
}
--
2.7.2.333.g70bd996.dirty
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