drm/fb-helper: Add drm_fb_helper_defio_init()

Add helper for initializing fbdev deferred I/O.

The cleanup could have happened in drm_fb_helper_fini(), but that would
have required me to set fb_info->fbdefio to NULL in a couple of drivers
before they call _fini() to avoid double defio cleanup. The problem is
that one of those is vboxvideo which lives in Greg's staging tree.
So I put the cleanup in drm_fb_helper_fbdev_teardown(), not perfect
but not that bad either.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171215175119.36181-6-noralf@tronnes.org
This commit is contained in:
Noralf Trønnes 2017-12-15 18:51:17 +01:00
parent 95b0137f28
commit 48c9571c34
2 changed files with 59 additions and 1 deletions

View File

@ -107,7 +107,8 @@ static DEFINE_MUTEX(kernel_fb_helper_lock);
* always run in process context since the fb_*() function could be running in
* atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
* callback it will also schedule dirty_work with the damage collected from the
* mmap page writes.
* mmap page writes. Drivers can use drm_fb_helper_defio_init() to setup
* deferred I/O (coupled with drm_fb_helper_fbdev_teardown()).
*/
#define drm_fb_helper_for_each_connector(fbh, i__) \
@ -1028,6 +1029,49 @@ void drm_fb_helper_deferred_io(struct fb_info *info,
}
EXPORT_SYMBOL(drm_fb_helper_deferred_io);
/**
* drm_fb_helper_defio_init - fbdev deferred I/O initialization
* @fb_helper: driver-allocated fbdev helper
*
* This function allocates &fb_deferred_io, sets callback to
* drm_fb_helper_deferred_io(), delay to 50ms and calls fb_deferred_io_init().
* It should be called from the &drm_fb_helper_funcs->fb_probe callback.
* drm_fb_helper_fbdev_teardown() cleans up deferred I/O.
*
* NOTE: A copy of &fb_ops is made and assigned to &info->fbops. This is done
* because fb_deferred_io_cleanup() clears &fbops->fb_mmap and would thereby
* affect other instances of that &fb_ops.
*
* Returns:
* 0 on success or a negative error code on failure.
*/
int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
{
struct fb_info *info = fb_helper->fbdev;
struct fb_deferred_io *fbdefio;
struct fb_ops *fbops;
fbdefio = kzalloc(sizeof(*fbdefio), GFP_KERNEL);
fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
if (!fbdefio || !fbops) {
kfree(fbdefio);
kfree(fbops);
return -ENOMEM;
}
info->fbdefio = fbdefio;
fbdefio->delay = msecs_to_jiffies(50);
fbdefio->deferred_io = drm_fb_helper_deferred_io;
*fbops = *info->fbops;
info->fbops = fbops;
fb_deferred_io_init(info);
return 0;
}
EXPORT_SYMBOL(drm_fb_helper_defio_init);
/**
* drm_fb_helper_sys_read - wrapper around fb_sys_read
* @info: fb_info struct pointer
@ -2824,6 +2868,7 @@ EXPORT_SYMBOL(drm_fb_helper_fbdev_setup);
void drm_fb_helper_fbdev_teardown(struct drm_device *dev)
{
struct drm_fb_helper *fb_helper = dev->fb_helper;
struct fb_ops *fbops = NULL;
if (!fb_helper)
return;
@ -2832,7 +2877,14 @@ void drm_fb_helper_fbdev_teardown(struct drm_device *dev)
if (fb_helper->fbdev && fb_helper->fbdev->dev)
drm_fb_helper_unregister_fbi(fb_helper);
if (fb_helper->fbdev && fb_helper->fbdev->fbdefio) {
fb_deferred_io_cleanup(fb_helper->fbdev);
kfree(fb_helper->fbdev->fbdefio);
fbops = fb_helper->fbdev->fbops;
}
drm_fb_helper_fini(fb_helper);
kfree(fbops);
if (fb_helper->fb)
drm_framebuffer_remove(fb_helper->fb);

View File

@ -276,6 +276,7 @@ void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);
void drm_fb_helper_deferred_io(struct fb_info *info,
struct list_head *pagelist);
int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper);
ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
size_t count, loff_t *ppos);
@ -423,6 +424,11 @@ static inline void drm_fb_helper_deferred_io(struct fb_info *info,
{
}
static inline int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
{
return -ENODEV;
}
static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
char __user *buf, size_t count,
loff_t *ppos)