[PATCH 13/18] iommu/tegra: 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@xxxxxxx>
---
 drivers/iommu/tegra-smmu.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 124c8848ab7e..8e276eac84d9 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -5,6 +5,7 @@
 
 #include <linux/bitops.h>
 #include <linux/debugfs.h>
+#include <linux/dma-iommu.h>
 #include <linux/err.h>
 #include <linux/iommu.h>
 #include <linux/kernel.h>
@@ -278,7 +279,7 @@ static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
 {
 	struct tegra_smmu_as *as;
 
-	if (type != IOMMU_DOMAIN_UNMANAGED)
+	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
 		return NULL;
 
 	as = kzalloc(sizeof(*as), GFP_KERNEL);
@@ -288,25 +289,19 @@ static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
 	as->attr = SMMU_PD_READABLE | SMMU_PD_WRITABLE | SMMU_PD_NONSECURE;
 
 	as->pd = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
-	if (!as->pd) {
-		kfree(as);
-		return NULL;
-	}
+	if (!as->pd)
+		goto out_free_as;
 
 	as->count = kcalloc(SMMU_NUM_PDE, sizeof(u32), GFP_KERNEL);
-	if (!as->count) {
-		__free_page(as->pd);
-		kfree(as);
-		return NULL;
-	}
+	if (!as->count)
+		goto out_free_all;
 
 	as->pts = kcalloc(SMMU_NUM_PDE, sizeof(*as->pts), GFP_KERNEL);
-	if (!as->pts) {
-		kfree(as->count);
-		__free_page(as->pd);
-		kfree(as);
-		return NULL;
-	}
+	if (!as->pts)
+		goto out_free_all;
+
+	if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(&as->domain))
+		goto out_free_all;
 
 	/* setup aperture */
 	as->domain.geometry.aperture_start = 0;
@@ -314,12 +309,22 @@ static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
 	as->domain.geometry.force_aperture = true;
 
 	return &as->domain;
+
+out_free_all:
+	kfree(as->pts);
+	kfree(as->count);
+	__free_page(as->pd);
+out_free_as:
+	kfree(as);
+	return NULL;
 }
 
 static void tegra_smmu_domain_free(struct iommu_domain *domain)
 {
 	struct tegra_smmu_as *as = to_smmu_as(domain);
 
+	iommu_put_dma_cookie(domain);
+
 	/* TODO: free page directory and page tables */
 
 	WARN_ON_ONCE(as->use_count);
-- 
2.28.0.dirty