drm/etnaviv: implement dma-buf mmap

This adds the required boilerplate to allow direct mmap of exported
etnaviv BOs.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_drv.c

@@ -505,6 +505,7 @@ static struct drm_driver etnaviv_drm_driver = {
 	.gem_prime_import_sg_table = etnaviv_gem_prime_import_sg_table,
 	.gem_prime_vmap     = etnaviv_gem_prime_vmap,
 	.gem_prime_vunmap   = etnaviv_gem_prime_vunmap,
+	.gem_prime_mmap     = etnaviv_gem_prime_mmap,
 #ifdef CONFIG_DEBUG_FS
 	.debugfs_init       = etnaviv_debugfs_init,
 	.debugfs_cleanup    = etnaviv_debugfs_cleanup,

drivers/gpu/drm/etnaviv/etnaviv_drv.h

@@ -78,6 +78,8 @@ int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, u64 *offset);
 struct sg_table *etnaviv_gem_prime_get_sg_table(struct drm_gem_object *obj);
 void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj);
 void etnaviv_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
+int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
+			   struct vm_area_struct *vma);
 struct drm_gem_object *etnaviv_gem_prime_import_sg_table(struct drm_device *dev,
 	struct dma_buf_attachment *attach, struct sg_table *sg);
 int etnaviv_gem_prime_pin(struct drm_gem_object *obj);

drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c

@@ -39,6 +39,19 @@ void etnaviv_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 	/* TODO msm_gem_vunmap() */
 }
 
+int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
+			   struct vm_area_struct *vma)
+{
+	struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
+	int ret;
+
+	ret = drm_gem_mmap_obj(obj, obj->size, vma);
+	if (ret < 0)
+		return ret;
+
+	return etnaviv_obj->ops->mmap(etnaviv_obj, vma);
+}
+
 int etnaviv_gem_prime_pin(struct drm_gem_object *obj)
 {
 	if (!obj->import_attach) {