drm/msm: honor GPU_READONLY flag

Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_drv.h

@@ -250,7 +250,8 @@ void msm_gem_purge_vma(struct msm_gem_address_space *aspace,
 void msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
 		struct msm_gem_vma *vma);
 int msm_gem_map_vma(struct msm_gem_address_space *aspace,
-		struct msm_gem_vma *vma, struct sg_table *sgt, int npages);
+		struct msm_gem_vma *vma, int prot,
+		struct sg_table *sgt, int npages);
 void msm_gem_close_vma(struct msm_gem_address_space *aspace,
 		struct msm_gem_vma *vma);
 

drivers/gpu/drm/msm/msm_gem.c

@@ -391,6 +391,10 @@ static int msm_gem_pin_iova(struct drm_gem_object *obj,
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_gem_vma *vma;
 	struct page **pages;
+	int prot = IOMMU_READ;
+
+	if (!(msm_obj->flags & MSM_BO_GPU_READONLY))
+		prot |= IOMMU_WRITE;
 
 	WARN_ON(!mutex_is_locked(&msm_obj->lock));
 
@@ -405,8 +409,8 @@ static int msm_gem_pin_iova(struct drm_gem_object *obj,
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);
 
-	return msm_gem_map_vma(aspace, vma, msm_obj->sgt,
-			obj->size >> PAGE_SHIFT);
+	return msm_gem_map_vma(aspace, vma, prot,
+			msm_obj->sgt, obj->size >> PAGE_SHIFT);
 }
 
 /* get iova and pin it. Should have a matching put */

drivers/gpu/drm/msm/msm_gem_vma.c

@@ -68,7 +68,8 @@ void msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
 
 int
 msm_gem_map_vma(struct msm_gem_address_space *aspace,
-		struct msm_gem_vma *vma, struct sg_table *sgt, int npages)
+		struct msm_gem_vma *vma, int prot,
+		struct sg_table *sgt, int npages)
 {
 	unsigned size = npages << PAGE_SHIFT;
 	int ret = 0;
@@ -86,7 +87,7 @@ msm_gem_map_vma(struct msm_gem_address_space *aspace,
 
 	if (aspace->mmu)
 		ret = aspace->mmu->funcs->map(aspace->mmu, vma->iova, sgt,
-				size, IOMMU_READ | IOMMU_WRITE);
+				size, prot);
 
 	if (ret)
 		vma->mapped = false;