[PATCH AUTOSEL 5.14 018/252] drm/vkms: Let shadow-plane helpers prepare the plane's FB

Sasha Levin
2021-09-09T11:42:33Z

From: Thomas Zimmermann <tzimmermann@suse.de>

[ Upstream commit b43e2ec03b0de040d536591713ea9c875ff34ba9 ]

Replace vkms' prepare_fb and cleanup_fb functions with the generic
code for shadow-buffered planes. No functional changes.

This change also fixes a problem where IGT kms_flip tests would
create a segmentation fault within vkms. The driver's prepare_fb
function did not report an error if a BO's vmap operation failed.
The kernel later tried to operate on the non-mapped memory areas.
The shared shadow-plane helpers handle errors correctly, so that
the driver now avoids the segmantation fault.

v2:
* include paragraph about IGT tests in commit message (Melissa)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210705074633.9425-4-tzimmermann@suse.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/vkms/vkms_plane.c | 38 +------------------------------
1 file changed, 1 insertion(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 107521ace597..092514a2155f 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -8,7 +8,6 @@
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_plane_helper.h>
-#include <drm/drm_gem_shmem_helper.h>

#include "vkms_drv.h"

@@ -150,45 +149,10 @@ static int vkms_plane_atomic_check(struct drm_plane *plane,
return 0;
}

-static int vkms_prepare_fb(struct drm_plane *plane,
- struct drm_plane_state *state)
-{
- struct drm_gem_object *gem_obj;
- struct dma_buf_map map;
- int ret;
-
- if (!state->fb)
- return 0;
-
- gem_obj = drm_gem_fb_get_obj(state->fb, 0);
- ret = drm_gem_shmem_vmap(gem_obj, &map);
- if (ret)
- DRM_ERROR("vmap failed: %d\n", ret);
-
- return drm_gem_plane_helper_prepare_fb(plane, state);
-}
-
-static void vkms_cleanup_fb(struct drm_plane *plane,
- struct drm_plane_state *old_state)
-{
- struct drm_gem_object *gem_obj;
- struct drm_gem_shmem_object *shmem_obj;
- struct dma_buf_map map;
-
- if (!old_state->fb)
- return;
-
- gem_obj = drm_gem_fb_get_obj(old_state->fb, 0);
- shmem_obj = to_drm_gem_shmem_obj(drm_gem_fb_get_obj(old_state->fb, 0));
- dma_buf_map_set_vaddr(&map, shmem_obj->vaddr);
- drm_gem_shmem_vunmap(gem_obj, &map);
-}
-
static const struct drm_plane_helper_funcs vkms_primary_helper_funcs = {
.atomic_update = vkms_plane_atomic_update,
.atomic_check = vkms_plane_atomic_check,
- .prepare_fb = vkms_prepare_fb,
- .cleanup_fb = vkms_cleanup_fb,
+ DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
};

struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
--
2.30.2