iommu/arm-smmu: Support DMA-API domains
With DMA mapping ops provided by the iommu-dma code, only a minimal
contribution from the IOMMU driver is needed to create a suitable
DMA-API domain for them to use. Implement this for the ARM SMMUs.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 1f9093d..e8e7bcc 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -29,6 +29,7 @@
#define pr_fmt(fmt) "arm-smmu: " fmt
#include <linux/delay.h>
+#include <linux/dma-iommu.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/interrupt.h>
@@ -966,7 +967,7 @@
{
struct arm_smmu_domain *smmu_domain;
- if (type != IOMMU_DOMAIN_UNMANAGED)
+ if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
return NULL;
/*
* Allocate the domain and initialise some of its data structures.
@@ -977,6 +978,12 @@
if (!smmu_domain)
return NULL;
+ if (type == IOMMU_DOMAIN_DMA &&
+ iommu_get_dma_cookie(&smmu_domain->domain)) {
+ kfree(smmu_domain);
+ return NULL;
+ }
+
mutex_init(&smmu_domain->init_mutex);
spin_lock_init(&smmu_domain->pgtbl_lock);
@@ -991,6 +998,7 @@
* Free the domain resources. We assume that all devices have
* already been detached.
*/
+ iommu_put_dma_cookie(domain);
arm_smmu_destroy_domain_context(domain);
kfree(smmu_domain);
}