drm/vram: Set GEM object functions for PRIME

PRIME functionality is now provided via the callback functions in
struct drm_gem_object_funcs. The driver-structure functions are obsolete.
As a side effect of this patch, VRAM-based drivers get basic PRIME
support automatically without having to set any flags or additional
fields.

v2:
	- use existing PRIME functions for object's table
v3:
	- move object table to EOF so it can refer to internal interfaces
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190702115012.4418-2-tzimmermann@suse.de

drivers/gpu/drm/drm_gem_vram_helper.c

@@ -7,6 +7,8 @@
 #include <drm/drm_vram_mm_helper.h>
 #include <drm/ttm/ttm_page_alloc.h>
 
+static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
+
 /**
  * DOC: overview
  *
@@ -80,6 +82,9 @@ static int drm_gem_vram_init(struct drm_device *dev,
 	int ret;
 	size_t acc_size;
 
+	if (!gbo->gem.funcs)
+		gbo->gem.funcs = &drm_gem_vram_object_funcs;
+
 	ret = drm_gem_object_init(dev, &gbo->gem, size);
 	if (ret)
 		return ret;
@@ -639,3 +644,15 @@ int drm_gem_vram_driver_gem_prime_mmap(struct drm_gem_object *gem,
 	return drm_gem_prime_mmap(gem, vma);
 }
 EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_mmap);
+
+/*
+ * GEM object funcs
+ */
+
+static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
+	.free	= drm_gem_vram_driver_gem_free_object_unlocked,
+	.pin	= drm_gem_vram_driver_gem_prime_pin,
+	.unpin	= drm_gem_vram_driver_gem_prime_unpin,
+	.vmap	= drm_gem_vram_driver_gem_prime_vmap,
+	.vunmap	= drm_gem_vram_driver_gem_prime_vunmap
+};

include/drm/drm_gem_vram_helper.h

@@ -127,7 +127,8 @@ int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
 	.gem_free_object_unlocked = \
 		drm_gem_vram_driver_gem_free_object_unlocked, \
 	.dumb_create		  = drm_gem_vram_driver_dumb_create, \
-	.dumb_map_offset	  = drm_gem_vram_driver_dumb_mmap_offset
+	.dumb_map_offset	  = drm_gem_vram_driver_dumb_mmap_offset, \
+	.gem_prime_mmap		  = drm_gem_prime_mmap
 
 /*
  * PRIME helpers for struct drm_driver