[Intel-gfx] [RFC v2 4/8] drm/fb-helper: Ensure driver module is pinned in fb_open()
If struct fb_ops is defined in a library like cma, fb_open() and fbcon takes a ref on the library instead of the driver module. Use fb_ops.fb_open/fb_release to ensure that the driver module is pinned. Signed-off-by: Noralf Trønnes --- drivers/gpu/drm/drm_fb_helper.c | 40 include/drm/drm_fb_helper.h | 13 + 2 files changed, 53 insertions(+) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 035784ddd133..2c6adf1d80c2 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1207,6 +1207,46 @@ void drm_fb_helper_cfb_imageblit(struct fb_info *info, } EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit); +/** + * drm_fb_helper_fb_open - implementation for &fb_ops.fb_open + * @info: fbdev registered by the helper + * @user: 1=userspace, 0=fbcon + * + * If &fb_ops is wrapped in a library, pin the driver module. + */ +int drm_fb_helper_fb_open(struct fb_info *info, int user) +{ + struct drm_fb_helper *fb_helper = info->par; + struct drm_device *dev = fb_helper->dev; + + if (info->fbops->owner != dev->driver->fops->owner) { + if (!try_module_get(dev->driver->fops->owner)) + return -ENODEV; + } + + return 0; +} +EXPORT_SYMBOL(drm_fb_helper_fb_open); + +/** + * drm_fb_helper_fb_release - implementation for &fb_ops.fb_release + * @info: fbdev registered by the helper + * @user: 1=userspace, 0=fbcon + * + * If &fb_ops is wrapped in a library, unpin the driver module. + */ +int drm_fb_helper_fb_release(struct fb_info *info, int user) +{ + struct drm_fb_helper *fb_helper = info->par; + struct drm_device *dev = fb_helper->dev; + + if (info->fbops->owner != dev->driver->fops->owner) + module_put(dev->driver->fops->owner); + + return 0; +} +EXPORT_SYMBOL(drm_fb_helper_fb_release); + /** * drm_fb_helper_set_suspend - wrapper around fb_set_suspend * @fb_helper: driver-allocated fbdev helper, can be NULL diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index b069433e7fc1..a593f01ff69e 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -297,6 +297,9 @@ void drm_fb_helper_cfb_copyarea(struct fb_info *info, void drm_fb_helper_cfb_imageblit(struct fb_info *info, const struct fb_image *image); +int drm_fb_helper_fb_open(struct fb_info *info, int user); +int drm_fb_helper_fb_release(struct fb_info *info, int user); + void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend); void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend); @@ -473,6 +476,16 @@ static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info, { } +static inline int drm_fb_helper_fb_open(struct fb_info *info, int user) +{ + return -ENODEV; +} + +static inline int drm_fb_helper_fb_release(struct fb_info *info, int user) +{ + return -ENODEV; +} + static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend) { -- 2.14.2 ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [RFC v2 4/8] drm/fb-helper: Ensure driver module is pinned in fb_open()
On Wed, Jan 03, 2018 at 11:21:06PM +0100, Noralf Trønnes wrote: > If struct fb_ops is defined in a library like cma, fb_open() and fbcon > takes a ref on the library instead of the driver module. Use > fb_ops.fb_open/fb_release to ensure that the driver module is pinned. > > Signed-off-by: Noralf Trønnes Reviewed-by: Daniel Vetter ... I guess the patch to roll it out to the various vfun tables and macros comes later? -Daniel > --- > drivers/gpu/drm/drm_fb_helper.c | 40 > include/drm/drm_fb_helper.h | 13 + > 2 files changed, 53 insertions(+) > > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > index 035784ddd133..2c6adf1d80c2 100644 > --- a/drivers/gpu/drm/drm_fb_helper.c > +++ b/drivers/gpu/drm/drm_fb_helper.c > @@ -1207,6 +1207,46 @@ void drm_fb_helper_cfb_imageblit(struct fb_info *info, > } > EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit); > > +/** > + * drm_fb_helper_fb_open - implementation for &fb_ops.fb_open > + * @info: fbdev registered by the helper > + * @user: 1=userspace, 0=fbcon > + * > + * If &fb_ops is wrapped in a library, pin the driver module. > + */ > +int drm_fb_helper_fb_open(struct fb_info *info, int user) > +{ > + struct drm_fb_helper *fb_helper = info->par; > + struct drm_device *dev = fb_helper->dev; > + > + if (info->fbops->owner != dev->driver->fops->owner) { > + if (!try_module_get(dev->driver->fops->owner)) > + return -ENODEV; > + } > + > + return 0; > +} > +EXPORT_SYMBOL(drm_fb_helper_fb_open); > + > +/** > + * drm_fb_helper_fb_release - implementation for &fb_ops.fb_release > + * @info: fbdev registered by the helper > + * @user: 1=userspace, 0=fbcon > + * > + * If &fb_ops is wrapped in a library, unpin the driver module. > + */ > +int drm_fb_helper_fb_release(struct fb_info *info, int user) > +{ > + struct drm_fb_helper *fb_helper = info->par; > + struct drm_device *dev = fb_helper->dev; > + > + if (info->fbops->owner != dev->driver->fops->owner) > + module_put(dev->driver->fops->owner); > + > + return 0; > +} > +EXPORT_SYMBOL(drm_fb_helper_fb_release); > + > /** > * drm_fb_helper_set_suspend - wrapper around fb_set_suspend > * @fb_helper: driver-allocated fbdev helper, can be NULL > diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h > index b069433e7fc1..a593f01ff69e 100644 > --- a/include/drm/drm_fb_helper.h > +++ b/include/drm/drm_fb_helper.h > @@ -297,6 +297,9 @@ void drm_fb_helper_cfb_copyarea(struct fb_info *info, > void drm_fb_helper_cfb_imageblit(struct fb_info *info, >const struct fb_image *image); > > +int drm_fb_helper_fb_open(struct fb_info *info, int user); > +int drm_fb_helper_fb_release(struct fb_info *info, int user); > + > void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool > suspend); > void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, > bool suspend); > @@ -473,6 +476,16 @@ static inline void drm_fb_helper_cfb_imageblit(struct > fb_info *info, > { > } > > +static inline int drm_fb_helper_fb_open(struct fb_info *info, int user) > +{ > + return -ENODEV; > +} > + > +static inline int drm_fb_helper_fb_release(struct fb_info *info, int user) > +{ > + return -ENODEV; > +} > + > static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, >bool suspend) > { > -- > 2.14.2 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [RFC v2 4/8] drm/fb-helper: Ensure driver module is pinned in fb_open()
On Wed, Jan 03, 2018 at 11:21:06PM +0100, Noralf Trønnes wrote: > If struct fb_ops is defined in a library like cma, fb_open() and fbcon > takes a ref on the library instead of the driver module. Use > fb_ops.fb_open/fb_release to ensure that the driver module is pinned. > > Signed-off-by: Noralf Trønnes > --- > drivers/gpu/drm/drm_fb_helper.c | 40 > include/drm/drm_fb_helper.h | 13 + > 2 files changed, 53 insertions(+) > > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > index 035784ddd133..2c6adf1d80c2 100644 > --- a/drivers/gpu/drm/drm_fb_helper.c > +++ b/drivers/gpu/drm/drm_fb_helper.c > @@ -1207,6 +1207,46 @@ void drm_fb_helper_cfb_imageblit(struct fb_info *info, > } > EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit); > > +/** > + * drm_fb_helper_fb_open - implementation for &fb_ops.fb_open > + * @info: fbdev registered by the helper > + * @user: 1=userspace, 0=fbcon > + * > + * If &fb_ops is wrapped in a library, pin the driver module. > + */ > +int drm_fb_helper_fb_open(struct fb_info *info, int user) > +{ > + struct drm_fb_helper *fb_helper = info->par; > + struct drm_device *dev = fb_helper->dev; > + > + if (info->fbops->owner != dev->driver->fops->owner) { Actually bikeshed potential here: I'd just unconditionally grab the module reference, makes the code simpler. Or is there a reason not to? -Daniel > + if (!try_module_get(dev->driver->fops->owner)) > + return -ENODEV; > + } > + > + return 0; > +} > +EXPORT_SYMBOL(drm_fb_helper_fb_open); > + > +/** > + * drm_fb_helper_fb_release - implementation for &fb_ops.fb_release > + * @info: fbdev registered by the helper > + * @user: 1=userspace, 0=fbcon > + * > + * If &fb_ops is wrapped in a library, unpin the driver module. > + */ > +int drm_fb_helper_fb_release(struct fb_info *info, int user) > +{ > + struct drm_fb_helper *fb_helper = info->par; > + struct drm_device *dev = fb_helper->dev; > + > + if (info->fbops->owner != dev->driver->fops->owner) > + module_put(dev->driver->fops->owner); > + > + return 0; > +} > +EXPORT_SYMBOL(drm_fb_helper_fb_release); > + > /** > * drm_fb_helper_set_suspend - wrapper around fb_set_suspend > * @fb_helper: driver-allocated fbdev helper, can be NULL > diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h > index b069433e7fc1..a593f01ff69e 100644 > --- a/include/drm/drm_fb_helper.h > +++ b/include/drm/drm_fb_helper.h > @@ -297,6 +297,9 @@ void drm_fb_helper_cfb_copyarea(struct fb_info *info, > void drm_fb_helper_cfb_imageblit(struct fb_info *info, >const struct fb_image *image); > > +int drm_fb_helper_fb_open(struct fb_info *info, int user); > +int drm_fb_helper_fb_release(struct fb_info *info, int user); > + > void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool > suspend); > void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, > bool suspend); > @@ -473,6 +476,16 @@ static inline void drm_fb_helper_cfb_imageblit(struct > fb_info *info, > { > } > > +static inline int drm_fb_helper_fb_open(struct fb_info *info, int user) > +{ > + return -ENODEV; > +} > + > +static inline int drm_fb_helper_fb_release(struct fb_info *info, int user) > +{ > + return -ENODEV; > +} > + > static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, >bool suspend) > { > -- > 2.14.2 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx