drm/selftests: Add tests for drm_internal_framebuffer_create

Add tests that verify that drm_internal_framebuffer_create creates
buffers correctly by creating a dummy drm_device with a mock function
for the fb_create callback.

To decide if a buffer has been created or not it just checks if
fb_create callback has been called for the particular drm_mode_fb_cmd2
that's being tested.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181101151051.1509-8-alexandru-cosmin.gheorghe@arm.com

drivers/gpu/drm/selftests/Makefile

 test-drm_modeset-y := test-drm_modeset_common.o test-drm_plane_helper.o \
-                      test-drm_format.o
+                      test-drm_format.o test-drm_framebuffer.o
 
 obj-$(CONFIG_DRM_DEBUG_SELFTEST) += test-drm_mm.o test-drm_modeset.o

drivers/gpu/drm/selftests/drm_modeset_selftests.h

@@ -10,3 +10,4 @@ selftest(check_plane_state, igt_check_plane_state)
 selftest(check_drm_format_block_width, igt_check_drm_format_block_width)
 selftest(check_drm_format_block_height, igt_check_drm_format_block_height)
 selftest(check_drm_format_min_pitch, igt_check_drm_format_min_pitch)
+selftest(check_drm_framebuffer_create, igt_check_drm_framebuffer_create)

drivers/gpu/drm/selftests/test-drm_modeset_common.h

@@ -17,5 +17,6 @@ int igt_check_plane_state(void *ignored);
 int igt_check_drm_format_block_width(void *ignored);
 int igt_check_drm_format_block_height(void *ignored);
 int igt_check_drm_format_min_pitch(void *ignored);
+int igt_check_drm_framebuffer_create(void *ignored);
 
 #endif