[PATCH 12/18] iommu/tegra-gart: Add IOMMU_DOMAIN_DMA support

[Robin Murphy]

Now that arch/arm is wired up for default domains and iommu-dma,
implement the corresponding driver-side support for DMA domains.

Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
 drivers/iommu/tegra-gart.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index fac720273889..e081387080f6 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -9,6 +9,7 @@
 
 #define dev_fmt(fmt)	"gart: " fmt
 
+#include <linux/dma-iommu.h>
 #include <linux/io.h>
 #include <linux/iommu.h>
 #include <linux/moduleparam.h>
@@ -145,16 +146,22 @@ static struct iommu_domain *gart_iommu_domain_alloc(unsigned type)
 {
 	struct iommu_domain *domain;
 
-	if (type != IOMMU_DOMAIN_UNMANAGED)
+	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
 		return NULL;
 
 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
-	if (domain) {
-		domain->geometry.aperture_start = gart_handle->iovmm_base;
-		domain->geometry.aperture_end = gart_handle->iovmm_end - 1;
-		domain->geometry.force_aperture = true;
+	if (!domain)
+		return NULL;
+
+	if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(domain)) {
+		kfree(domain);
+		return NULL;
 	}
 
+	domain->geometry.aperture_start = gart_handle->iovmm_base;
+	domain->geometry.aperture_end = gart_handle->iovmm_end - 1;
+	domain->geometry.force_aperture = true;
+
 	return domain;
 }
 
-- 
2.28.0.dirty