iommu/tegra-smmu: Respect IOMMU API read-write protections

Set PTE read/write attributes accordingly to the the protections requested
by IOMMU API.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/tegra-smmu.c

@@ -145,8 +145,6 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
 
 #define SMMU_PDE_ATTR		(SMMU_PDE_READABLE | SMMU_PDE_WRITABLE | \
 				 SMMU_PDE_NONSECURE)
-#define SMMU_PTE_ATTR		(SMMU_PTE_READABLE | SMMU_PTE_WRITABLE | \
-				 SMMU_PTE_NONSECURE)
 
 static unsigned int iova_pd_index(unsigned long iova)
 {
@@ -659,6 +657,7 @@ static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
 {
 	struct tegra_smmu_as *as = to_smmu_as(domain);
 	dma_addr_t pte_dma;
+	u32 pte_attrs;
 	u32 *pte;
 
 	pte = as_get_pte(as, iova, &pte_dma);
@@ -669,8 +668,16 @@ static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
 	if (*pte == 0)
 		tegra_smmu_pte_get_use(as, iova);
 
+	pte_attrs = SMMU_PTE_NONSECURE;
+
+	if (prot & IOMMU_READ)
+		pte_attrs |= SMMU_PTE_READABLE;
+
+	if (prot & IOMMU_WRITE)
+		pte_attrs |= SMMU_PTE_WRITABLE;
+
 	tegra_smmu_set_pte(as, iova, pte, pte_dma,
-			   __phys_to_pfn(paddr) | SMMU_PTE_ATTR);
+			   __phys_to_pfn(paddr) | pte_attrs);
 
 	return 0;
 }