bochs: convert to drm_fb_helper_fbdev_setup/teardown

Currently unloading bochs_drm (after unbinding the vtconsole) results in
a warning about a leaked connector:

    [drm:drm_mode_config_cleanup] *ERROR* connector Virtual-3 leaked!

While investigating a potential fix I noticed that a lot of open-coded
functionality is already implemented elsewhere, so start converting it:
bochs_fbdev_init -> drm_fb_helper_fbdev_setup: trivial (similar impl).
bochs_fbdev_fini -> drm_fb_helper_fbdev_teardown: requires unembedding
"struct drm_framebuffer" from "struct bochs_framebuffer".

Unembedding drm_framebuffer is made easy using drm_gem_fbdev_fb_create
which can replace bochs_fbdev_destroy and custom routines in bochs_mm.c.
For this to work, the GEM object is moved into "drm_framebuffer". After
that, "bochs_framebuffer" is no longer needed and therefore removed.

Remove the unused "size" and "initialized" fields from fb, the latter is
not necessary as drm_fb_helper_fbdev_teardown can be called even if
bochsfb_create fails. This theory was tested by returning early and
late (just before drm_gem_fbdev_fb_create). Both scenarios fail
gracefully although the latter seems to leak the object from
bochsfb_create_object (not a regression).

Guess on the reason for the encoder leak: drm_framebuffer_cleanup was
previously used, but did not destroy much. drm_fb_helper_fbdev_teardown
is now used and calls drm_framebuffer_remove which does a bit more work.

Tested with 'echo 0 > /sys/class/vtconsole/vtcon1/bind; rmmod bochs_drm'
and also with Xorg + fbdev (startx -> xterm). The latter triggered a
warning in ttm_bo_vm_open that existed before, see
https://lkml.kernel.org/r/1464000533-13140-4-git-send-email-mstaudt@suse.de

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Link: http://patchwork.freedesktop.org/patch/msgid/20180906221810.20170-3-peter@lekensteyn.nl
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 0 insertions, 74 deletions

diff --git a/drivers/gpu/drm/bochs/bochs_mm.c b/drivers/gpu/drm/bochs/bochs_mm.c
index c9c7097030ca..a61c1ecb2bdc 100644
--- a/drivers/gpu/drm/bochs/bochs_mm.c
+++ b/drivers/gpu/drm/bochs/bochs_mm.c
@@ -457,77 +457,3 @@ int bochs_dumb_mmap_offset(struct drm_file *file, struct drm_device *dev,
 	drm_gem_object_unreference_unlocked(obj);
 	return 0;
 }
-
-/* ---------------------------------------------------------------------- */
-
-static void bochs_user_framebuffer_destroy(struct drm_framebuffer *fb)
-{
-	struct bochs_framebuffer *bochs_fb = to_bochs_framebuffer(fb);
-
-	drm_gem_object_unreference_unlocked(bochs_fb->obj);
-	drm_framebuffer_cleanup(fb);
-	kfree(fb);
-}
-
-static const struct drm_framebuffer_funcs bochs_fb_funcs = {
-	.destroy = bochs_user_framebuffer_destroy,
-};
-
-int bochs_framebuffer_init(struct drm_device *dev,
-			   struct bochs_framebuffer *gfb,
-			   const struct drm_mode_fb_cmd2 *mode_cmd,
-			   struct drm_gem_object *obj)
-{
-	int ret;
-
-	drm_helper_mode_fill_fb_struct(dev, &gfb->base, mode_cmd);
-	gfb->obj = obj;
-	ret = drm_framebuffer_init(dev, &gfb->base, &bochs_fb_funcs);
-	if (ret) {
-		DRM_ERROR("drm_framebuffer_init failed: %d\n", ret);
-		return ret;
-	}
-	return 0;
-}
-
-static struct drm_framebuffer *
-bochs_user_framebuffer_create(struct drm_device *dev,
-			      struct drm_file *filp,
-			      const struct drm_mode_fb_cmd2 *mode_cmd)
-{
-	struct drm_gem_object *obj;
-	struct bochs_framebuffer *bochs_fb;
-	int ret;
-
-	DRM_DEBUG_DRIVER("%dx%d, format %c%c%c%c\n",
-	       mode_cmd->width, mode_cmd->height,
-	       (mode_cmd->pixel_format)       & 0xff,
-	       (mode_cmd->pixel_format >> 8)  & 0xff,
-	       (mode_cmd->pixel_format >> 16) & 0xff,
-	       (mode_cmd->pixel_format >> 24) & 0xff);
-
-	if (mode_cmd->pixel_format != DRM_FORMAT_XRGB8888)
-		return ERR_PTR(-ENOENT);
-
-	obj = drm_gem_object_lookup(filp, mode_cmd->handles[0]);
-	if (obj == NULL)
-		return ERR_PTR(-ENOENT);
-
-	bochs_fb = kzalloc(sizeof(*bochs_fb), GFP_KERNEL);
-	if (!bochs_fb) {
-		drm_gem_object_unreference_unlocked(obj);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	ret = bochs_framebuffer_init(dev, bochs_fb, mode_cmd, obj);
-	if (ret) {
-		drm_gem_object_unreference_unlocked(obj);
-		kfree(bochs_fb);
-		return ERR_PTR(ret);
-	}
-	return &bochs_fb->base;
-}
-
-const struct drm_mode_config_funcs bochs_mode_funcs = {
-	.fb_create = bochs_user_framebuffer_create,
-};