drm/radeon: add PRIME support (v2)

This adds prime->fd and fd->prime support to radeon.
It passes the sg object to ttm and then populates
the gart entries using it.

Compile tested only.

v2: stub kmap + use new helpers + add reimporting

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index 1affbc9..830f1a7 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -104,7 +104,7 @@
 
 int radeon_bo_create(struct radeon_device *rdev,
 		     unsigned long size, int byte_align, bool kernel, u32 domain,
-		     struct radeon_bo **bo_ptr)
+		     struct sg_table *sg, struct radeon_bo **bo_ptr)
 {
 	struct radeon_bo *bo;
 	enum ttm_bo_type type;
@@ -120,6 +120,8 @@
 	}
 	if (kernel) {
 		type = ttm_bo_type_kernel;
+	} else if (sg) {
+		type = ttm_bo_type_sg;
 	} else {
 		type = ttm_bo_type_device;
 	}
@@ -155,7 +157,7 @@
 	mutex_lock(&rdev->vram_mutex);
 	r = ttm_bo_init(&rdev->mman.bdev, &bo->tbo, size, type,
 			&bo->placement, page_align, 0, !kernel, NULL,
-			acc_size, NULL, &radeon_ttm_bo_destroy);
+			acc_size, sg, &radeon_ttm_bo_destroy);
 	mutex_unlock(&rdev->vram_mutex);
 	if (unlikely(r != 0)) {
 		if (r != -ERESTARTSYS) {