drm: Add default instance for VRAM MM callback functions

VRAM MM is most likely be used with GEM VRAM. The latter now provides the
required instance of struct drm_vram_mm_funcs for drivers to use.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-8-tzimmermann@suse.deSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/drm_gem_vram_helper.c

@@ -3,6 +3,7 @@
 #include <drm/drm_gem_vram_helper.h>
 #include <drm/drm_mode.h>
 #include <drm/drm_prime.h>
+#include <drm/drm_vram_mm_helper.h>
 #include <drm/ttm/ttm_page_alloc.h>
 
 /**
@@ -524,6 +525,19 @@ int drm_gem_vram_bo_driver_verify_access(struct ttm_buffer_object *bo,
 }
 EXPORT_SYMBOL(drm_gem_vram_bo_driver_verify_access);
 
+/**
+ * drm_gem_vram_mm_funcs - Functions for &struct drm_vram_mm
+ *
+ * Most users of @struct drm_gem_vram_object will also use
+ * @struct drm_vram_mm. This instance of &struct drm_vram_mm_funcs
+ * can be used to connect both.
+ */
+const struct drm_vram_mm_funcs drm_gem_vram_mm_funcs = {
+	.evict_flags = drm_gem_vram_bo_driver_evict_flags,
+	.verify_access = drm_gem_vram_bo_driver_verify_access
+};
+EXPORT_SYMBOL(drm_gem_vram_mm_funcs);
+
 /*
  * Helpers for struct drm_driver
  */

include/drm/drm_gem_vram_helper.h

@@ -9,6 +9,7 @@
 #include <linux/kernel.h> /* for container_of() */
 
 struct drm_mode_create_dumb;
+struct drm_vram_mm_funcs;
 struct filp;
 
 #define DRM_GEM_VRAM_PL_FLAG_VRAM	TTM_PL_FLAG_VRAM
@@ -107,6 +108,8 @@ void drm_gem_vram_bo_driver_evict_flags(struct ttm_buffer_object *bo,
 int drm_gem_vram_bo_driver_verify_access(struct ttm_buffer_object *bo,
 					 struct file *filp);
 
+extern const struct drm_vram_mm_funcs drm_gem_vram_mm_funcs;
+
 /*
  * Helpers for struct drm_driver
  */