[PATCH 00/13] video, drm: constify fbops in struct fb_info

[PATCH 00/13] video, drm: constify fbops in struct fb_info

[Jani Nikula]

So I wanted to quickly move our struct fb_ops to const data because we
don't modify it... and this series is where the rabbit hole ends. Ugh.

The main pain point is deferred IO, which is covered in patch
1. Everything gets easier after that. The last 5 could be merged at
leisure.

BR,
Jani.


Jani Nikula (13):
  video: fb_defio: preserve user fb_ops
  drm/fb-helper: don't preserve fb_ops across deferred IO use
  video: smscufx: don't restore fb_mmap after deferred IO cleanup
  video: udlfb: don't restore fb_mmap after deferred IO cleanup
  video: fbdev: vesafb: modify the static fb_ops directly
  video: fbmem: use const pointer for fb_ops
  video: omapfb: use const pointer for fb_ops
  video: fbdev: make fbops member of struct fb_info a const pointer
  drm: constify fb ops across all drivers
  video: constify fb ops across all drivers
  HID: picoLCD: constify fb ops
  media: constify fb ops across all drivers
  samples: vfio-mdev: constify fb ops

 drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c        |  2 +-
 drivers/gpu/drm/armada/armada_fbdev.c         |  2 +-
 drivers/gpu/drm/drm_fb_helper.c               | 20 +++------------
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c     |  2 +-
 .../gpu/drm/hisilicon/hibmc/hibmc_drm_fbdev.c |  2 +-
 drivers/gpu/drm/i915/display/intel_fbdev.c    |  2 +-
 drivers/gpu/drm/msm/msm_fbdev.c               |  2 +-
 drivers/gpu/drm/nouveau/nouveau_fbcon.c       |  4 +--
 drivers/gpu/drm/omapdrm/omap_fbdev.c          |  2 +-
 drivers/gpu/drm/radeon/radeon_fb.c            |  2 +-
 drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c |  2 +-
 drivers/gpu/drm/tegra/fb.c                    |  2 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_fb.c            |  2 +-
 drivers/hid/hid-picolcd_fb.c                  |  3 +--
 drivers/media/pci/ivtv/ivtvfb.c               |  3 +--
 drivers/media/platform/vivid/vivid-osd.c      |  1 -
 drivers/video/fbdev/68328fb.c                 |  2 +-
 drivers/video/fbdev/acornfb.c                 |  2 +-
 drivers/video/fbdev/amba-clcd.c               |  2 +-
 drivers/video/fbdev/amifb.c                   |  2 +-
 drivers/video/fbdev/arcfb.c                   |  2 +-
 drivers/video/fbdev/arkfb.c                   |  2 +-
 drivers/video/fbdev/asiliantfb.c              |  2 +-
 drivers/video/fbdev/atmel_lcdfb.c             |  2 +-
 drivers/video/fbdev/aty/aty128fb.c            |  2 +-
 drivers/video/fbdev/aty/atyfb_base.c          |  2 +-
 drivers/video/fbdev/aty/radeon_base.c         |  2 +-
 drivers/video/fbdev/au1100fb.c                |  2 +-
 drivers/video/fbdev/au1200fb.c                |  2 +-
 drivers/video/fbdev/broadsheetfb.c            |  2 +-
 drivers/video/fbdev/bw2.c                     |  2 +-
 drivers/video/fbdev/carminefb.c               |  2 +-
 drivers/video/fbdev/cg14.c                    |  2 +-
 drivers/video/fbdev/cg3.c                     |  2 +-
 drivers/video/fbdev/cg6.c                     |  2 +-
 drivers/video/fbdev/chipsfb.c                 |  2 +-
 drivers/video/fbdev/cirrusfb.c                |  2 +-
 drivers/video/fbdev/clps711x-fb.c             |  2 +-
 drivers/video/fbdev/cobalt_lcdfb.c            |  2 +-
 drivers/video/fbdev/controlfb.c               |  2 +-
 drivers/video/fbdev/core/fb_defio.c           | 25 ++++++++++++++++---
 drivers/video/fbdev/core/fbmem.c              |  6 ++---
 drivers/video/fbdev/cyber2000fb.c             |  2 +-
 drivers/video/fbdev/da8xx-fb.c                |  2 +-
 drivers/video/fbdev/dnfb.c                    |  2 +-
 drivers/video/fbdev/efifb.c                   |  2 +-
 drivers/video/fbdev/ep93xx-fb.c               |  2 +-
 drivers/video/fbdev/fb-puv3.c                 |  2 +-
 drivers/video/fbdev/ffb.c                     |  2 +-
 drivers/video/fbdev/fm2fb.c                   |  2 +-
 drivers/video/fbdev/fsl-diu-fb.c              |  2 +-
 drivers/video/fbdev/g364fb.c                  |  2 +-
 drivers/video/fbdev/gbefb.c                   |  2 +-
 drivers/video/fbdev/geode/gx1fb_core.c        |  2 +-
 drivers/video/fbdev/geode/gxfb_core.c         |  2 +-
 drivers/video/fbdev/geode/lxfb_core.c         |  2 +-
 drivers/video/fbdev/goldfishfb.c              |  2 +-
 drivers/video/fbdev/grvga.c                   |  2 +-
 drivers/video/fbdev/gxt4500.c                 |  2 +-
 drivers/video/fbdev/hecubafb.c                |  2 +-
 drivers/video/fbdev/hgafb.c                   |  2 +-
 drivers/video/fbdev/hitfb.c                   |  2 +-
 drivers/video/fbdev/hpfb.c                    |  2 +-
 drivers/video/fbdev/hyperv_fb.c               |  2 +-
 drivers/video/fbdev/i740fb.c                  |  2 +-
 drivers/video/fbdev/imsttfb.c                 |  2 +-
 drivers/video/fbdev/imxfb.c                   |  2 +-
 drivers/video/fbdev/intelfb/intelfbdrv.c      |  2 +-
 drivers/video/fbdev/kyro/fbdev.c              |  2 +-
 drivers/video/fbdev/leo.c                     |  2 +-
 drivers/video/fbdev/macfb.c                   |  2 +-
 drivers/video/fbdev/matrox/matroxfb_crtc2.c   |  2 +-
 drivers/video/fbdev/maxinefb.c                |  2 +-
 drivers/video/fbdev/mb862xx/mb862xxfbdrv.c    |  2 +-
 drivers/video/fbdev/mbx/mbxfb.c               |  2 +-
 drivers/video/fbdev/metronomefb.c             |  2 +-
 drivers/video/fbdev/mmp/fb/mmpfb.c            |  2 +-
 drivers/video/fbdev/mx3fb.c                   |  5 ++--
 drivers/video/fbdev/neofb.c                   |  2 +-
 drivers/video/fbdev/nvidia/nvidia.c           |  2 +-
 drivers/video/fbdev/ocfb.c                    |  2 +-
 drivers/video/fbdev/offb.c                    |  2 +-
 drivers/video/fbdev/omap/omapfb_main.c        |  2 +-
 .../video/fbdev/omap2/omapfb/omapfb-main.c    |  2 +-
 drivers/video/fbdev/p9100.c                   |  2 +-
 drivers/video/fbdev/platinumfb.c              |  2 +-
 drivers/video/fbdev/pm2fb.c                   |  2 +-
 drivers/video/fbdev/pm3fb.c                   |  2 +-
 drivers/video/fbdev/pmag-aa-fb.c              |  2 +-
 drivers/video/fbdev/pmag-ba-fb.c              |  2 +-
 drivers/video/fbdev/pmagb-b-fb.c              |  2 +-
 drivers/video/fbdev/ps3fb.c                   |  2 +-
 drivers/video/fbdev/pvr2fb.c                  |  2 +-
 drivers/video/fbdev/pxa168fb.c                |  2 +-
 drivers/video/fbdev/pxafb.c                   |  4 +--
 drivers/video/fbdev/q40fb.c                   |  2 +-
 drivers/video/fbdev/riva/fbdev.c              |  2 +-
 drivers/video/fbdev/s3c-fb.c                  |  2 +-
 drivers/video/fbdev/s3c2410fb.c               |  2 +-
 drivers/video/fbdev/s3fb.c                    |  2 +-
 drivers/video/fbdev/sa1100fb.c                |  2 +-
 drivers/video/fbdev/savage/savagefb_driver.c  |  2 +-
 drivers/video/fbdev/sh7760fb.c                |  2 +-
 drivers/video/fbdev/sh_mobile_lcdcfb.c        |  4 +--
 drivers/video/fbdev/simplefb.c                |  2 +-
 drivers/video/fbdev/sis/sis_main.c            |  2 +-
 drivers/video/fbdev/skeletonfb.c              |  2 +-
 drivers/video/fbdev/sm712fb.c                 |  2 +-
 drivers/video/fbdev/smscufx.c                 |  1 -
 drivers/video/fbdev/ssd1307fb.c               |  2 +-
 drivers/video/fbdev/sstfb.c                   |  2 +-
 drivers/video/fbdev/stifb.c                   |  2 +-
 drivers/video/fbdev/sunxvr1000.c              |  2 +-
 drivers/video/fbdev/sunxvr2500.c              |  2 +-
 drivers/video/fbdev/sunxvr500.c               |  2 +-
 drivers/video/fbdev/tcx.c                     |  2 +-
 drivers/video/fbdev/tdfxfb.c                  |  2 +-
 drivers/video/fbdev/tgafb.c                   |  2 +-
 drivers/video/fbdev/tmiofb.c                  |  2 +-
 drivers/video/fbdev/tridentfb.c               |  2 +-
 drivers/video/fbdev/udlfb.c                   |  1 -
 drivers/video/fbdev/uvesafb.c                 |  2 +-
 drivers/video/fbdev/valkyriefb.c              |  2 +-
 drivers/video/fbdev/vesafb.c                  |  6 ++---
 drivers/video/fbdev/vfb.c                     |  2 +-
 drivers/video/fbdev/vga16fb.c                 |  2 +-
 drivers/video/fbdev/vt8500lcdfb.c             |  2 +-
 drivers/video/fbdev/vt8623fb.c                |  2 +-
 drivers/video/fbdev/w100fb.c                  |  2 +-
 drivers/video/fbdev/wm8505fb.c                |  2 +-
 drivers/video/fbdev/xen-fbfront.c             |  2 +-
 drivers/video/fbdev/xilinxfb.c                |  2 +-
 include/linux/fb.h                            |  5 ++--
 samples/vfio-mdev/mdpy-fb.c                   |  2 +-
 134 files changed, 165 insertions(+), 163 deletions(-)

-- 
2.20.1

[PATCH 01/13] video: fb_defio: preserve user fb_ops

[Jani Nikula]

Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
and then resetting it to NULL afterwards causes problems all over the
place. First, it prevents making the fbops member of struct fb_info a
const pointer, which means we can't make struct fb_ops const
anywhere. Second, a few places have to go out of their way to restore
the original fb_mmap pointer that gets reset to NULL.

Preserve the passed in fb_ops by making a copy of it and modifying that
instead. Add a deferred_io_private member to struct fb_info to store the
pointer to the old fb_ops, and restore that at cleanup.

Cc: Jaya Kumar <jayalk@intworks.biz>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Note: If the approach is acceptable, we'll also need to handle the error
returns on memory allocation failures at fb_deferred_io_init() call
sites. There are 13.
---
 drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
 include/linux/fb.h                  |  3 ++-
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index 82c20c6047b0..36697844c1e0 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
 	mutex_unlock(&fbdefio->lock);
 }
 
-void fb_deferred_io_init(struct fb_info *info)
+int fb_deferred_io_init(struct fb_info *info)
 {
 	struct fb_deferred_io *fbdefio = info->fbdefio;
+	struct fb_ops *fbops;
 
 	BUG_ON(!fbdefio);
+
+	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
+	if (!fbops)
+		return -ENOMEM;
+
+	fbops->fb_mmap = fb_deferred_io_mmap;
+	info->deferred_io_private = info->fbops;
+	info->fbops = fbops;
+
 	mutex_init(&fbdefio->lock);
-	info->fbops->fb_mmap = fb_deferred_io_mmap;
+
 	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
 	INIT_LIST_HEAD(&fbdefio->pagelist);
 	if (fbdefio->delay = 0) /* set a default of 1 s */
@@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
 	int i;
 
 	BUG_ON(!fbdefio);
+
+	/* sanity check against misuse */
+	if (WARN_ON(!info->deferred_io_private ||
+		    info->fbops->fb_mmap != fb_deferred_io_mmap))
+		return;
+
 	cancel_delayed_work_sync(&info->deferred_work);
 
 	/* clear out the mapping that we setup */
@@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
 		page->mapping = NULL;
 	}
 
-	info->fbops->fb_mmap = NULL;
+	kfree(info->fbops);
+	info->fbops = info->deferred_io_private;
+	info->deferred_io_private = NULL;
+
 	mutex_destroy(&fbdefio->lock);
 }
 EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
diff --git a/include/linux/fb.h b/include/linux/fb.h
index a6ad528990de..65f2abd47745 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -470,6 +470,7 @@ struct fb_info {
 #ifdef CONFIG_FB_DEFERRED_IO
 	struct delayed_work deferred_work;
 	struct fb_deferred_io *fbdefio;
+	void *deferred_io_private;
 #endif
 
 	struct fb_ops *fbops;
@@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
 
 /* drivers/video/fb_defio.c */
 int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
-extern void fb_deferred_io_init(struct fb_info *info);
+extern int fb_deferred_io_init(struct fb_info *info);
 extern void fb_deferred_io_open(struct fb_info *info,
 				struct inode *inode,
 				struct file *file);
-- 
2.20.1

Re: [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Ville Syrjälä]

On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
> Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
> and then resetting it to NULL afterwards causes problems all over the
> place. First, it prevents making the fbops member of struct fb_info a
> const pointer, which means we can't make struct fb_ops const
> anywhere. Second, a few places have to go out of their way to restore
> the original fb_mmap pointer that gets reset to NULL.
> 
> Preserve the passed in fb_ops by making a copy of it and modifying that
> instead. Add a deferred_io_private member to struct fb_info to store the
> pointer to the old fb_ops, and restore that at cleanup.

Quite the horror show. I wonder how hard it would be to just have each
driver that can use defio provide a mmap hook that either dispatches
to the defio one or the native one depending if defio is used or not...

A few drivers at least seem to always use defio so those should be
trivial. Some others seem to make the decision dynamically, which
would require custom .mmap(). Though I suppose all of them could just
be of the form
foo_mmap_wrap{)
{
	if (info->defio)
		defio_mmap()
	else
		foo_mmap();
}

Hmm. Actually is .fb_mmap() called from anywhere but fb_mmap()? If not
we could just shove the defio check there? Or if it's called from
several places we could try to wrap all calls in _fb_mmap() or somesuch.

> 
> Cc: Jaya Kumar <jayalk@intworks.biz>
> Cc: linux-fbdev@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> 
> ---
> 
> Note: If the approach is acceptable, we'll also need to handle the error
> returns on memory allocation failures at fb_deferred_io_init() call
> sites. There are 13.
> ---
>  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
>  include/linux/fb.h                  |  3 ++-
>  2 files changed, 24 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
> index 82c20c6047b0..36697844c1e0 100644
> --- a/drivers/video/fbdev/core/fb_defio.c
> +++ b/drivers/video/fbdev/core/fb_defio.c
> @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
>  	mutex_unlock(&fbdefio->lock);
>  }
>  
> -void fb_deferred_io_init(struct fb_info *info)
> +int fb_deferred_io_init(struct fb_info *info)
>  {
>  	struct fb_deferred_io *fbdefio = info->fbdefio;
> +	struct fb_ops *fbops;
>  
>  	BUG_ON(!fbdefio);
> +
> +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
> +	if (!fbops)
> +		return -ENOMEM;
> +
> +	fbops->fb_mmap = fb_deferred_io_mmap;
> +	info->deferred_io_private = info->fbops;
> +	info->fbops = fbops;
> +
>  	mutex_init(&fbdefio->lock);
> -	info->fbops->fb_mmap = fb_deferred_io_mmap;
> +
>  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
>  	INIT_LIST_HEAD(&fbdefio->pagelist);
>  	if (fbdefio->delay = 0) /* set a default of 1 s */
> @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>  	int i;
>  
>  	BUG_ON(!fbdefio);
> +
> +	/* sanity check against misuse */
> +	if (WARN_ON(!info->deferred_io_private ||
> +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
> +		return;
> +
>  	cancel_delayed_work_sync(&info->deferred_work);
>  
>  	/* clear out the mapping that we setup */
> @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>  		page->mapping = NULL;
>  	}
>  
> -	info->fbops->fb_mmap = NULL;
> +	kfree(info->fbops);
> +	info->fbops = info->deferred_io_private;
> +	info->deferred_io_private = NULL;
> +
>  	mutex_destroy(&fbdefio->lock);
>  }
>  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index a6ad528990de..65f2abd47745 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -470,6 +470,7 @@ struct fb_info {
>  #ifdef CONFIG_FB_DEFERRED_IO
>  	struct delayed_work deferred_work;
>  	struct fb_deferred_io *fbdefio;
> +	void *deferred_io_private;
>  #endif
>  
>  	struct fb_ops *fbops;
> @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
>  
>  /* drivers/video/fb_defio.c */
>  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
> -extern void fb_deferred_io_init(struct fb_info *info);
> +extern int fb_deferred_io_init(struct fb_info *info);
>  extern void fb_deferred_io_open(struct fb_info *info,
>  				struct inode *inode,
>  				struct file *file);
> -- 
> 2.20.1

-- 
Ville Syrjälä
Intel

Re: [Intel-gfx] [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Daniel Vetter]

On Wed, Nov 27, 2019 at 07:01:16PM +0200, Ville Syrjälä wrote:
> On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
> > Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
> > and then resetting it to NULL afterwards causes problems all over the
> > place. First, it prevents making the fbops member of struct fb_info a
> > const pointer, which means we can't make struct fb_ops const
> > anywhere. Second, a few places have to go out of their way to restore
> > the original fb_mmap pointer that gets reset to NULL.
> > 
> > Preserve the passed in fb_ops by making a copy of it and modifying that
> > instead. Add a deferred_io_private member to struct fb_info to store the
> > pointer to the old fb_ops, and restore that at cleanup.
> 
> Quite the horror show. I wonder how hard it would be to just have each
> driver that can use defio provide a mmap hook that either dispatches
> to the defio one or the native one depending if defio is used or not...
> 
> A few drivers at least seem to always use defio so those should be
> trivial. Some others seem to make the decision dynamically, which
> would require custom .mmap(). Though I suppose all of them could just
> be of the form
> foo_mmap_wrap{)
> {
> 	if (info->defio)
> 		defio_mmap()
> 	else
> 		foo_mmap();
> }
> 
> Hmm. Actually is .fb_mmap() called from anywhere but fb_mmap()? If not
> we could just shove the defio check there? Or if it's called from
> several places we could try to wrap all calls in _fb_mmap() or somesuch.

While we're spinning this garn about fb_mmap improvements: My cunning
plan, documented in todo.rst even, is to have our own fb_mmap
implementation for the drm fbdev helper, which will handle all this
internally.

And then just quietly burn down the fbdev defio stuff to the ground,
because it's the stuff for nightmares.

https://dri.freedesktop.org/docs/drm/gpu/todo.html#generic-fbdev-defio-support

tldr; Imo no point investing too much in polishing the defio stuff.
-Daniel

> 
> > 
> > Cc: Jaya Kumar <jayalk@intworks.biz>
> > Cc: linux-fbdev@vger.kernel.org
> > Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> > 
> > ---
> > 
> > Note: If the approach is acceptable, we'll also need to handle the error
> > returns on memory allocation failures at fb_deferred_io_init() call
> > sites. There are 13.
> > ---
> >  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
> >  include/linux/fb.h                  |  3 ++-
> >  2 files changed, 24 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
> > index 82c20c6047b0..36697844c1e0 100644
> > --- a/drivers/video/fbdev/core/fb_defio.c
> > +++ b/drivers/video/fbdev/core/fb_defio.c
> > @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
> >  	mutex_unlock(&fbdefio->lock);
> >  }
> >  
> > -void fb_deferred_io_init(struct fb_info *info)
> > +int fb_deferred_io_init(struct fb_info *info)
> >  {
> >  	struct fb_deferred_io *fbdefio = info->fbdefio;
> > +	struct fb_ops *fbops;
> >  
> >  	BUG_ON(!fbdefio);
> > +
> > +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
> > +	if (!fbops)
> > +		return -ENOMEM;
> > +
> > +	fbops->fb_mmap = fb_deferred_io_mmap;
> > +	info->deferred_io_private = info->fbops;
> > +	info->fbops = fbops;
> > +
> >  	mutex_init(&fbdefio->lock);
> > -	info->fbops->fb_mmap = fb_deferred_io_mmap;
> > +
> >  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
> >  	INIT_LIST_HEAD(&fbdefio->pagelist);
> >  	if (fbdefio->delay = 0) /* set a default of 1 s */
> > @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> >  	int i;
> >  
> >  	BUG_ON(!fbdefio);
> > +
> > +	/* sanity check against misuse */
> > +	if (WARN_ON(!info->deferred_io_private ||
> > +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
> > +		return;
> > +
> >  	cancel_delayed_work_sync(&info->deferred_work);
> >  
> >  	/* clear out the mapping that we setup */
> > @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> >  		page->mapping = NULL;
> >  	}
> >  
> > -	info->fbops->fb_mmap = NULL;
> > +	kfree(info->fbops);
> > +	info->fbops = info->deferred_io_private;
> > +	info->deferred_io_private = NULL;
> > +
> >  	mutex_destroy(&fbdefio->lock);
> >  }
> >  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
> > diff --git a/include/linux/fb.h b/include/linux/fb.h
> > index a6ad528990de..65f2abd47745 100644
> > --- a/include/linux/fb.h
> > +++ b/include/linux/fb.h
> > @@ -470,6 +470,7 @@ struct fb_info {
> >  #ifdef CONFIG_FB_DEFERRED_IO
> >  	struct delayed_work deferred_work;
> >  	struct fb_deferred_io *fbdefio;
> > +	void *deferred_io_private;
> >  #endif
> >  
> >  	struct fb_ops *fbops;
> > @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
> >  
> >  /* drivers/video/fb_defio.c */
> >  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
> > -extern void fb_deferred_io_init(struct fb_info *info);
> > +extern int fb_deferred_io_init(struct fb_info *info);
> >  extern void fb_deferred_io_open(struct fb_info *info,
> >  				struct inode *inode,
> >  				struct file *file);
> > -- 
> > 2.20.1
> 
> -- 
> Ville Syrjälä
> Intel
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [Intel-gfx] [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Daniel Vetter]

On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
> Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
> and then resetting it to NULL afterwards causes problems all over the
> place. First, it prevents making the fbops member of struct fb_info a
> const pointer, which means we can't make struct fb_ops const
> anywhere. Second, a few places have to go out of their way to restore
> the original fb_mmap pointer that gets reset to NULL.
> 
> Preserve the passed in fb_ops by making a copy of it and modifying that
> instead. Add a deferred_io_private member to struct fb_info to store the
> pointer to the old fb_ops, and restore that at cleanup.
> 
> Cc: Jaya Kumar <jayalk@intworks.biz>
> Cc: linux-fbdev@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> 
> ---
> 
> Note: If the approach is acceptable, we'll also need to handle the error
> returns on memory allocation failures at fb_deferred_io_init() call
> sites. There are 13.

it's fbdev defio, I think we can do worse with less effort. Just embed a
copy of fb_ops into fb_info, and use that, and tada! no memory allocation
needed :-)

I'd totally r-b that patch.

Or do what Ville suggested, add an fb_info->fbdefio.enabled, set that in
the _init function and in fb_mmap call fb_deferred_io_mmap for that case
instead of the driver's fb_ops->fb_mmap. There's only one caller of that
in the entire tree, in fbmem.c. Also, we could/should nuke the
EXPORT_SYMBOL(fb_deferred_io_mmap) I think.

That version would also get my r-b stamp. So up to you what you prefer.
-Daniel

> ---
>  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
>  include/linux/fb.h                  |  3 ++-
>  2 files changed, 24 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
> index 82c20c6047b0..36697844c1e0 100644
> --- a/drivers/video/fbdev/core/fb_defio.c
> +++ b/drivers/video/fbdev/core/fb_defio.c
> @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
>  	mutex_unlock(&fbdefio->lock);
>  }
>  
> -void fb_deferred_io_init(struct fb_info *info)
> +int fb_deferred_io_init(struct fb_info *info)
>  {
>  	struct fb_deferred_io *fbdefio = info->fbdefio;
> +	struct fb_ops *fbops;
>  
>  	BUG_ON(!fbdefio);
> +
> +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
> +	if (!fbops)
> +		return -ENOMEM;
> +
> +	fbops->fb_mmap = fb_deferred_io_mmap;
> +	info->deferred_io_private = info->fbops;
> +	info->fbops = fbops;
> +
>  	mutex_init(&fbdefio->lock);
> -	info->fbops->fb_mmap = fb_deferred_io_mmap;
> +
>  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
>  	INIT_LIST_HEAD(&fbdefio->pagelist);
>  	if (fbdefio->delay = 0) /* set a default of 1 s */
> @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>  	int i;
>  
>  	BUG_ON(!fbdefio);
> +
> +	/* sanity check against misuse */
> +	if (WARN_ON(!info->deferred_io_private ||
> +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
> +		return;
> +
>  	cancel_delayed_work_sync(&info->deferred_work);
>  
>  	/* clear out the mapping that we setup */
> @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>  		page->mapping = NULL;
>  	}
>  
> -	info->fbops->fb_mmap = NULL;
> +	kfree(info->fbops);
> +	info->fbops = info->deferred_io_private;
> +	info->deferred_io_private = NULL;
> +
>  	mutex_destroy(&fbdefio->lock);
>  }
>  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index a6ad528990de..65f2abd47745 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -470,6 +470,7 @@ struct fb_info {
>  #ifdef CONFIG_FB_DEFERRED_IO
>  	struct delayed_work deferred_work;
>  	struct fb_deferred_io *fbdefio;
> +	void *deferred_io_private;
>  #endif
>  
>  	struct fb_ops *fbops;
> @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
>  
>  /* drivers/video/fb_defio.c */
>  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
> -extern void fb_deferred_io_init(struct fb_info *info);
> +extern int fb_deferred_io_init(struct fb_info *info);
>  extern void fb_deferred_io_open(struct fb_info *info,
>  				struct inode *inode,
>  				struct file *file);
> -- 
> 2.20.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [Intel-gfx] [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Daniel Vetter]

On Wed, Nov 27, 2019 at 07:17:41PM +0100, Daniel Vetter wrote:
> On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
> > Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
> > and then resetting it to NULL afterwards causes problems all over the
> > place. First, it prevents making the fbops member of struct fb_info a
> > const pointer, which means we can't make struct fb_ops const
> > anywhere. Second, a few places have to go out of their way to restore
> > the original fb_mmap pointer that gets reset to NULL.
> > 
> > Preserve the passed in fb_ops by making a copy of it and modifying that
> > instead. Add a deferred_io_private member to struct fb_info to store the
> > pointer to the old fb_ops, and restore that at cleanup.
> > 
> > Cc: Jaya Kumar <jayalk@intworks.biz>
> > Cc: linux-fbdev@vger.kernel.org
> > Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> > 
> > ---
> > 
> > Note: If the approach is acceptable, we'll also need to handle the error
> > returns on memory allocation failures at fb_deferred_io_init() call
> > sites. There are 13.
> 
> it's fbdev defio, I think we can do worse with less effort. Just embed a
> copy of fb_ops into fb_info, and use that, and tada! no memory allocation
> needed :-)
> 
> I'd totally r-b that patch.
> 
> Or do what Ville suggested, add an fb_info->fbdefio.enabled, set that in
> the _init function and in fb_mmap call fb_deferred_io_mmap for that case
> instead of the driver's fb_ops->fb_mmap. There's only one caller of that
> in the entire tree, in fbmem.c. Also, we could/should nuke the
> EXPORT_SYMBOL(fb_deferred_io_mmap) I think.

I just realized that fb_info->fbdefio is a pointer, so this would be
really simple to pull off I think.
-Daniel

> 
> That version would also get my r-b stamp. So up to you what you prefer.
> -Daniel
> 
> > ---
> >  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
> >  include/linux/fb.h                  |  3 ++-
> >  2 files changed, 24 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
> > index 82c20c6047b0..36697844c1e0 100644
> > --- a/drivers/video/fbdev/core/fb_defio.c
> > +++ b/drivers/video/fbdev/core/fb_defio.c
> > @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
> >  	mutex_unlock(&fbdefio->lock);
> >  }
> >  
> > -void fb_deferred_io_init(struct fb_info *info)
> > +int fb_deferred_io_init(struct fb_info *info)
> >  {
> >  	struct fb_deferred_io *fbdefio = info->fbdefio;
> > +	struct fb_ops *fbops;
> >  
> >  	BUG_ON(!fbdefio);
> > +
> > +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
> > +	if (!fbops)
> > +		return -ENOMEM;
> > +
> > +	fbops->fb_mmap = fb_deferred_io_mmap;
> > +	info->deferred_io_private = info->fbops;
> > +	info->fbops = fbops;
> > +
> >  	mutex_init(&fbdefio->lock);
> > -	info->fbops->fb_mmap = fb_deferred_io_mmap;
> > +
> >  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
> >  	INIT_LIST_HEAD(&fbdefio->pagelist);
> >  	if (fbdefio->delay = 0) /* set a default of 1 s */
> > @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> >  	int i;
> >  
> >  	BUG_ON(!fbdefio);
> > +
> > +	/* sanity check against misuse */
> > +	if (WARN_ON(!info->deferred_io_private ||
> > +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
> > +		return;
> > +
> >  	cancel_delayed_work_sync(&info->deferred_work);
> >  
> >  	/* clear out the mapping that we setup */
> > @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> >  		page->mapping = NULL;
> >  	}
> >  
> > -	info->fbops->fb_mmap = NULL;
> > +	kfree(info->fbops);
> > +	info->fbops = info->deferred_io_private;
> > +	info->deferred_io_private = NULL;
> > +
> >  	mutex_destroy(&fbdefio->lock);
> >  }
> >  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
> > diff --git a/include/linux/fb.h b/include/linux/fb.h
> > index a6ad528990de..65f2abd47745 100644
> > --- a/include/linux/fb.h
> > +++ b/include/linux/fb.h
> > @@ -470,6 +470,7 @@ struct fb_info {
> >  #ifdef CONFIG_FB_DEFERRED_IO
> >  	struct delayed_work deferred_work;
> >  	struct fb_deferred_io *fbdefio;
> > +	void *deferred_io_private;
> >  #endif
> >  
> >  	struct fb_ops *fbops;
> > @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
> >  
> >  /* drivers/video/fb_defio.c */
> >  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
> > -extern void fb_deferred_io_init(struct fb_info *info);
> > +extern int fb_deferred_io_init(struct fb_info *info);
> >  extern void fb_deferred_io_open(struct fb_info *info,
> >  				struct inode *inode,
> >  				struct file *file);
> > -- 
> > 2.20.1
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [Intel-gfx] [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Jani Nikula]

On Wed, 27 Nov 2019, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Wed, Nov 27, 2019 at 07:17:41PM +0100, Daniel Vetter wrote:
>> On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
>> > Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
>> > and then resetting it to NULL afterwards causes problems all over the
>> > place. First, it prevents making the fbops member of struct fb_info a
>> > const pointer, which means we can't make struct fb_ops const
>> > anywhere. Second, a few places have to go out of their way to restore
>> > the original fb_mmap pointer that gets reset to NULL.
>> > 
>> > Preserve the passed in fb_ops by making a copy of it and modifying that
>> > instead. Add a deferred_io_private member to struct fb_info to store the
>> > pointer to the old fb_ops, and restore that at cleanup.
>> > 
>> > Cc: Jaya Kumar <jayalk@intworks.biz>
>> > Cc: linux-fbdev@vger.kernel.org
>> > Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> > 
>> > ---
>> > 
>> > Note: If the approach is acceptable, we'll also need to handle the error
>> > returns on memory allocation failures at fb_deferred_io_init() call
>> > sites. There are 13.
>> 
>> it's fbdev defio, I think we can do worse with less effort. Just embed a
>> copy of fb_ops into fb_info, and use that, and tada! no memory allocation
>> needed :-)
>> 
>> I'd totally r-b that patch.
>> 
>> Or do what Ville suggested, add an fb_info->fbdefio.enabled, set that in
>> the _init function and in fb_mmap call fb_deferred_io_mmap for that case
>> instead of the driver's fb_ops->fb_mmap. There's only one caller of that
>> in the entire tree, in fbmem.c. Also, we could/should nuke the
>> EXPORT_SYMBOL(fb_deferred_io_mmap) I think.
>
> I just realized that fb_info->fbdefio is a pointer, so this would be
> really simple to pull off I think.

Heh, having a

	int (*fb_deferred_io_mmap)(struct fb_info *, struct vm_area_struct *);

member in struct fb_info, and using that in fbmem.c if non-NULL, was
actually my first idea. I didn't think it was particularly pretty, but
if we don't care about aesthetics...

Would you like that instead of the patch at hand?


BR,
Jani.


> -Daniel
>
>> 
>> That version would also get my r-b stamp. So up to you what you prefer.
>> -Daniel
>> 
>> > ---
>> >  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
>> >  include/linux/fb.h                  |  3 ++-
>> >  2 files changed, 24 insertions(+), 4 deletions(-)
>> > 
>> > diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
>> > index 82c20c6047b0..36697844c1e0 100644
>> > --- a/drivers/video/fbdev/core/fb_defio.c
>> > +++ b/drivers/video/fbdev/core/fb_defio.c
>> > @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
>> >  	mutex_unlock(&fbdefio->lock);
>> >  }
>> >  
>> > -void fb_deferred_io_init(struct fb_info *info)
>> > +int fb_deferred_io_init(struct fb_info *info)
>> >  {
>> >  	struct fb_deferred_io *fbdefio = info->fbdefio;
>> > +	struct fb_ops *fbops;
>> >  
>> >  	BUG_ON(!fbdefio);
>> > +
>> > +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
>> > +	if (!fbops)
>> > +		return -ENOMEM;
>> > +
>> > +	fbops->fb_mmap = fb_deferred_io_mmap;
>> > +	info->deferred_io_private = info->fbops;
>> > +	info->fbops = fbops;
>> > +
>> >  	mutex_init(&fbdefio->lock);
>> > -	info->fbops->fb_mmap = fb_deferred_io_mmap;
>> > +
>> >  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
>> >  	INIT_LIST_HEAD(&fbdefio->pagelist);
>> >  	if (fbdefio->delay = 0) /* set a default of 1 s */
>> > @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>> >  	int i;
>> >  
>> >  	BUG_ON(!fbdefio);
>> > +
>> > +	/* sanity check against misuse */
>> > +	if (WARN_ON(!info->deferred_io_private ||
>> > +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
>> > +		return;
>> > +
>> >  	cancel_delayed_work_sync(&info->deferred_work);
>> >  
>> >  	/* clear out the mapping that we setup */
>> > @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>> >  		page->mapping = NULL;
>> >  	}
>> >  
>> > -	info->fbops->fb_mmap = NULL;
>> > +	kfree(info->fbops);
>> > +	info->fbops = info->deferred_io_private;
>> > +	info->deferred_io_private = NULL;
>> > +
>> >  	mutex_destroy(&fbdefio->lock);
>> >  }
>> >  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
>> > diff --git a/include/linux/fb.h b/include/linux/fb.h
>> > index a6ad528990de..65f2abd47745 100644
>> > --- a/include/linux/fb.h
>> > +++ b/include/linux/fb.h
>> > @@ -470,6 +470,7 @@ struct fb_info {
>> >  #ifdef CONFIG_FB_DEFERRED_IO
>> >  	struct delayed_work deferred_work;
>> >  	struct fb_deferred_io *fbdefio;
>> > +	void *deferred_io_private;
>> >  #endif
>> >  
>> >  	struct fb_ops *fbops;
>> > @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
>> >  
>> >  /* drivers/video/fb_defio.c */
>> >  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
>> > -extern void fb_deferred_io_init(struct fb_info *info);
>> > +extern int fb_deferred_io_init(struct fb_info *info);
>> >  extern void fb_deferred_io_open(struct fb_info *info,
>> >  				struct inode *inode,
>> >  				struct file *file);
>> > -- 
>> > 2.20.1
>> > 
>> > _______________________________________________
>> > Intel-gfx mailing list
>> > Intel-gfx@lists.freedesktop.org
>> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> 
>> -- 
>> Daniel Vetter
>> Software Engineer, Intel Corporation
>> http://blog.ffwll.ch

-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [Intel-gfx] [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Daniel Vetter]

On Thu, Nov 28, 2019 at 11:09:46AM +0200, Jani Nikula wrote:
> On Wed, 27 Nov 2019, Daniel Vetter <daniel@ffwll.ch> wrote:
> > On Wed, Nov 27, 2019 at 07:17:41PM +0100, Daniel Vetter wrote:
> >> On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
> >> > Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
> >> > and then resetting it to NULL afterwards causes problems all over the
> >> > place. First, it prevents making the fbops member of struct fb_info a
> >> > const pointer, which means we can't make struct fb_ops const
> >> > anywhere. Second, a few places have to go out of their way to restore
> >> > the original fb_mmap pointer that gets reset to NULL.
> >> > 
> >> > Preserve the passed in fb_ops by making a copy of it and modifying that
> >> > instead. Add a deferred_io_private member to struct fb_info to store the
> >> > pointer to the old fb_ops, and restore that at cleanup.
> >> > 
> >> > Cc: Jaya Kumar <jayalk@intworks.biz>
> >> > Cc: linux-fbdev@vger.kernel.org
> >> > Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> >> > 
> >> > ---
> >> > 
> >> > Note: If the approach is acceptable, we'll also need to handle the error
> >> > returns on memory allocation failures at fb_deferred_io_init() call
> >> > sites. There are 13.
> >> 
> >> it's fbdev defio, I think we can do worse with less effort. Just embed a
> >> copy of fb_ops into fb_info, and use that, and tada! no memory allocation
> >> needed :-)
> >> 
> >> I'd totally r-b that patch.
> >> 
> >> Or do what Ville suggested, add an fb_info->fbdefio.enabled, set that in
> >> the _init function and in fb_mmap call fb_deferred_io_mmap for that case
> >> instead of the driver's fb_ops->fb_mmap. There's only one caller of that
> >> in the entire tree, in fbmem.c. Also, we could/should nuke the
> >> EXPORT_SYMBOL(fb_deferred_io_mmap) I think.
> >
> > I just realized that fb_info->fbdefio is a pointer, so this would be
> > really simple to pull off I think.
> 
> Heh, having a
> 
> 	int (*fb_deferred_io_mmap)(struct fb_info *, struct vm_area_struct *);
> 
> member in struct fb_info, and using that in fbmem.c if non-NULL, was
> actually my first idea. I didn't think it was particularly pretty, but
> if we don't care about aesthetics...
> 
> Would you like that instead of the patch at hand?


diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index 82c20c6047b0..9275c6bd71da 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -206,13 +206,11 @@ void fb_deferred_io_init(struct fb_info *info)
 
 	BUG_ON(!fbdefio);
 	mutex_init(&fbdefio->lock);
-	info->fbops->fb_mmap = fb_deferred_io_mmap;
 	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
 	INIT_LIST_HEAD(&fbdefio->pagelist);
 	if (fbdefio->delay = 0) /* set a default of 1 s */
 		fbdefio->delay = HZ;
 }
-EXPORT_SYMBOL_GPL(fb_deferred_io_init);
 
 void fb_deferred_io_open(struct fb_info *info,
 			 struct inode *inode,
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 86b06a599f96..6af627f281c3 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1341,7 +1341,16 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
 		return -ENODEV;
 	fb = info->fbops;
 	mutex_lock(&info->mm_lock);
-	if (fb->fb_mmap) {
+	if (fb->fbdefio) {
+		/*
+		 * The framebuffer needs to be accessed decrypted, be sure
+		 * SME protection is removed ahead of the call
+		 */
+		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
+		res = fb_deferred_io_mmap(info, vma);
+		mutex_unlock(&info->mm_lock);
+		return res;
+	} else if (fb->fb_mmap) {
 		int res;
 
 		/*

Is what I was thinking off as the pretty solution. Add an explicit
fb_info->fbdefio_enabled boolean if you don't feel like auditing all the
drivers for whether they really call defio_init() every time they assign
something to that pointer. A quick scan brought some nasties to light in
that area.

I think a function pointer here is pointless because we clearly don't need
it, and with all the panic around function pointers a direct call feels
much better :-)
-Daniel

> 
> BR,
> Jani.
> 
> 
> > -Daniel
> >
> >> 
> >> That version would also get my r-b stamp. So up to you what you prefer.
> >> -Daniel
> >> 
> >> > ---
> >> >  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
> >> >  include/linux/fb.h                  |  3 ++-
> >> >  2 files changed, 24 insertions(+), 4 deletions(-)
> >> > 
> >> > diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
> >> > index 82c20c6047b0..36697844c1e0 100644
> >> > --- a/drivers/video/fbdev/core/fb_defio.c
> >> > +++ b/drivers/video/fbdev/core/fb_defio.c
> >> > @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
> >> >  	mutex_unlock(&fbdefio->lock);
> >> >  }
> >> >  
> >> > -void fb_deferred_io_init(struct fb_info *info)
> >> > +int fb_deferred_io_init(struct fb_info *info)
> >> >  {
> >> >  	struct fb_deferred_io *fbdefio = info->fbdefio;
> >> > +	struct fb_ops *fbops;
> >> >  
> >> >  	BUG_ON(!fbdefio);
> >> > +
> >> > +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
> >> > +	if (!fbops)
> >> > +		return -ENOMEM;
> >> > +
> >> > +	fbops->fb_mmap = fb_deferred_io_mmap;
> >> > +	info->deferred_io_private = info->fbops;
> >> > +	info->fbops = fbops;
> >> > +
> >> >  	mutex_init(&fbdefio->lock);
> >> > -	info->fbops->fb_mmap = fb_deferred_io_mmap;
> >> > +
> >> >  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
> >> >  	INIT_LIST_HEAD(&fbdefio->pagelist);
> >> >  	if (fbdefio->delay = 0) /* set a default of 1 s */
> >> > @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> >> >  	int i;
> >> >  
> >> >  	BUG_ON(!fbdefio);
> >> > +
> >> > +	/* sanity check against misuse */
> >> > +	if (WARN_ON(!info->deferred_io_private ||
> >> > +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
> >> > +		return;
> >> > +
> >> >  	cancel_delayed_work_sync(&info->deferred_work);
> >> >  
> >> >  	/* clear out the mapping that we setup */
> >> > @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> >> >  		page->mapping = NULL;
> >> >  	}
> >> >  
> >> > -	info->fbops->fb_mmap = NULL;
> >> > +	kfree(info->fbops);
> >> > +	info->fbops = info->deferred_io_private;
> >> > +	info->deferred_io_private = NULL;
> >> > +
> >> >  	mutex_destroy(&fbdefio->lock);
> >> >  }
> >> >  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
> >> > diff --git a/include/linux/fb.h b/include/linux/fb.h
> >> > index a6ad528990de..65f2abd47745 100644
> >> > --- a/include/linux/fb.h
> >> > +++ b/include/linux/fb.h
> >> > @@ -470,6 +470,7 @@ struct fb_info {
> >> >  #ifdef CONFIG_FB_DEFERRED_IO
> >> >  	struct delayed_work deferred_work;
> >> >  	struct fb_deferred_io *fbdefio;
> >> > +	void *deferred_io_private;
> >> >  #endif
> >> >  
> >> >  	struct fb_ops *fbops;
> >> > @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
> >> >  
> >> >  /* drivers/video/fb_defio.c */
> >> >  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
> >> > -extern void fb_deferred_io_init(struct fb_info *info);
> >> > +extern int fb_deferred_io_init(struct fb_info *info);
> >> >  extern void fb_deferred_io_open(struct fb_info *info,
> >> >  				struct inode *inode,
> >> >  				struct file *file);
> >> > -- 
> >> > 2.20.1
> >> > 
> >> > _______________________________________________
> >> > Intel-gfx mailing list
> >> > Intel-gfx@lists.freedesktop.org
> >> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >> 
> >> -- 
> >> Daniel Vetter
> >> Software Engineer, Intel Corporation
> >> http://blog.ffwll.ch
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [Intel-gfx] [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Daniel Vetter]

On Thu, Nov 28, 2019 at 11:05:57AM +0100, Daniel Vetter wrote:
> On Thu, Nov 28, 2019 at 11:09:46AM +0200, Jani Nikula wrote:
> > On Wed, 27 Nov 2019, Daniel Vetter <daniel@ffwll.ch> wrote:
> > > On Wed, Nov 27, 2019 at 07:17:41PM +0100, Daniel Vetter wrote:
> > >> On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
> > >> > Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
> > >> > and then resetting it to NULL afterwards causes problems all over the
> > >> > place. First, it prevents making the fbops member of struct fb_info a
> > >> > const pointer, which means we can't make struct fb_ops const
> > >> > anywhere. Second, a few places have to go out of their way to restore
> > >> > the original fb_mmap pointer that gets reset to NULL.
> > >> > 
> > >> > Preserve the passed in fb_ops by making a copy of it and modifying that
> > >> > instead. Add a deferred_io_private member to struct fb_info to store the
> > >> > pointer to the old fb_ops, and restore that at cleanup.
> > >> > 
> > >> > Cc: Jaya Kumar <jayalk@intworks.biz>
> > >> > Cc: linux-fbdev@vger.kernel.org
> > >> > Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> > >> > 
> > >> > ---
> > >> > 
> > >> > Note: If the approach is acceptable, we'll also need to handle the error
> > >> > returns on memory allocation failures at fb_deferred_io_init() call
> > >> > sites. There are 13.
> > >> 
> > >> it's fbdev defio, I think we can do worse with less effort. Just embed a
> > >> copy of fb_ops into fb_info, and use that, and tada! no memory allocation
> > >> needed :-)
> > >> 
> > >> I'd totally r-b that patch.
> > >> 
> > >> Or do what Ville suggested, add an fb_info->fbdefio.enabled, set that in
> > >> the _init function and in fb_mmap call fb_deferred_io_mmap for that case
> > >> instead of the driver's fb_ops->fb_mmap. There's only one caller of that
> > >> in the entire tree, in fbmem.c. Also, we could/should nuke the
> > >> EXPORT_SYMBOL(fb_deferred_io_mmap) I think.
> > >
> > > I just realized that fb_info->fbdefio is a pointer, so this would be
> > > really simple to pull off I think.
> > 
> > Heh, having a
> > 
> > 	int (*fb_deferred_io_mmap)(struct fb_info *, struct vm_area_struct *);
> > 
> > member in struct fb_info, and using that in fbmem.c if non-NULL, was
> > actually my first idea. I didn't think it was particularly pretty, but
> > if we don't care about aesthetics...
> > 
> > Would you like that instead of the patch at hand?
> 
> 
> diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
> index 82c20c6047b0..9275c6bd71da 100644
> --- a/drivers/video/fbdev/core/fb_defio.c
> +++ b/drivers/video/fbdev/core/fb_defio.c
> @@ -206,13 +206,11 @@ void fb_deferred_io_init(struct fb_info *info)
>  
>  	BUG_ON(!fbdefio);
>  	mutex_init(&fbdefio->lock);
> -	info->fbops->fb_mmap = fb_deferred_io_mmap;
>  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
>  	INIT_LIST_HEAD(&fbdefio->pagelist);
>  	if (fbdefio->delay = 0) /* set a default of 1 s */
>  		fbdefio->delay = HZ;
>  }
> -EXPORT_SYMBOL_GPL(fb_deferred_io_init);
>  
>  void fb_deferred_io_open(struct fb_info *info,
>  			 struct inode *inode,
> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
> index 86b06a599f96..6af627f281c3 100644
> --- a/drivers/video/fbdev/core/fbmem.c
> +++ b/drivers/video/fbdev/core/fbmem.c
> @@ -1341,7 +1341,16 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
>  		return -ENODEV;
>  	fb = info->fbops;
>  	mutex_lock(&info->mm_lock);
> -	if (fb->fb_mmap) {
> +	if (fb->fbdefio) {
> +		/*
> +		 * The framebuffer needs to be accessed decrypted, be sure
> +		 * SME protection is removed ahead of the call
> +		 */
> +		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
> +		res = fb_deferred_io_mmap(info, vma);
> +		mutex_unlock(&info->mm_lock);
> +		return res;
> +	} else if (fb->fb_mmap) {
>  		int res;
>  
>  		/*
> 
> Is what I was thinking off as the pretty solution. Add an explicit
> fb_info->fbdefio_enabled boolean if you don't feel like auditing all the
> drivers for whether they really call defio_init() every time they assign
> something to that pointer. A quick scan brought some nasties to light in
> that area.

Correction, brain wasn't awake yet, I've done the audit and the above diff
should work afaict.
-Daniel

> 
> I think a function pointer here is pointless because we clearly don't need
> it, and with all the panic around function pointers a direct call feels
> much better :-)
> -Daniel
> 
> > 
> > BR,
> > Jani.
> > 
> > 
> > > -Daniel
> > >
> > >> 
> > >> That version would also get my r-b stamp. So up to you what you prefer.
> > >> -Daniel
> > >> 
> > >> > ---
> > >> >  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
> > >> >  include/linux/fb.h                  |  3 ++-
> > >> >  2 files changed, 24 insertions(+), 4 deletions(-)
> > >> > 
> > >> > diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
> > >> > index 82c20c6047b0..36697844c1e0 100644
> > >> > --- a/drivers/video/fbdev/core/fb_defio.c
> > >> > +++ b/drivers/video/fbdev/core/fb_defio.c
> > >> > @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
> > >> >  	mutex_unlock(&fbdefio->lock);
> > >> >  }
> > >> >  
> > >> > -void fb_deferred_io_init(struct fb_info *info)
> > >> > +int fb_deferred_io_init(struct fb_info *info)
> > >> >  {
> > >> >  	struct fb_deferred_io *fbdefio = info->fbdefio;
> > >> > +	struct fb_ops *fbops;
> > >> >  
> > >> >  	BUG_ON(!fbdefio);
> > >> > +
> > >> > +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
> > >> > +	if (!fbops)
> > >> > +		return -ENOMEM;
> > >> > +
> > >> > +	fbops->fb_mmap = fb_deferred_io_mmap;
> > >> > +	info->deferred_io_private = info->fbops;
> > >> > +	info->fbops = fbops;
> > >> > +
> > >> >  	mutex_init(&fbdefio->lock);
> > >> > -	info->fbops->fb_mmap = fb_deferred_io_mmap;
> > >> > +
> > >> >  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
> > >> >  	INIT_LIST_HEAD(&fbdefio->pagelist);
> > >> >  	if (fbdefio->delay = 0) /* set a default of 1 s */
> > >> > @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> > >> >  	int i;
> > >> >  
> > >> >  	BUG_ON(!fbdefio);
> > >> > +
> > >> > +	/* sanity check against misuse */
> > >> > +	if (WARN_ON(!info->deferred_io_private ||
> > >> > +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
> > >> > +		return;
> > >> > +
> > >> >  	cancel_delayed_work_sync(&info->deferred_work);
> > >> >  
> > >> >  	/* clear out the mapping that we setup */
> > >> > @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
> > >> >  		page->mapping = NULL;
> > >> >  	}
> > >> >  
> > >> > -	info->fbops->fb_mmap = NULL;
> > >> > +	kfree(info->fbops);
> > >> > +	info->fbops = info->deferred_io_private;
> > >> > +	info->deferred_io_private = NULL;
> > >> > +
> > >> >  	mutex_destroy(&fbdefio->lock);
> > >> >  }
> > >> >  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
> > >> > diff --git a/include/linux/fb.h b/include/linux/fb.h
> > >> > index a6ad528990de..65f2abd47745 100644
> > >> > --- a/include/linux/fb.h
> > >> > +++ b/include/linux/fb.h
> > >> > @@ -470,6 +470,7 @@ struct fb_info {
> > >> >  #ifdef CONFIG_FB_DEFERRED_IO
> > >> >  	struct delayed_work deferred_work;
> > >> >  	struct fb_deferred_io *fbdefio;
> > >> > +	void *deferred_io_private;
> > >> >  #endif
> > >> >  
> > >> >  	struct fb_ops *fbops;
> > >> > @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
> > >> >  
> > >> >  /* drivers/video/fb_defio.c */
> > >> >  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
> > >> > -extern void fb_deferred_io_init(struct fb_info *info);
> > >> > +extern int fb_deferred_io_init(struct fb_info *info);
> > >> >  extern void fb_deferred_io_open(struct fb_info *info,
> > >> >  				struct inode *inode,
> > >> >  				struct file *file);
> > >> > -- 
> > >> > 2.20.1
> > >> > 
> > >> > _______________________________________________
> > >> > Intel-gfx mailing list
> > >> > Intel-gfx@lists.freedesktop.org
> > >> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > >> 
> > >> -- 
> > >> Daniel Vetter
> > >> Software Engineer, Intel Corporation
> > >> http://blog.ffwll.ch
> > 
> > -- 
> > Jani Nikula, Intel Open Source Graphics Center
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [Intel-gfx] [PATCH 01/13] video: fb_defio: preserve user fb_ops

[Jani Nikula]

On Thu, 28 Nov 2019, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Thu, Nov 28, 2019 at 11:05:57AM +0100, Daniel Vetter wrote:
>> On Thu, Nov 28, 2019 at 11:09:46AM +0200, Jani Nikula wrote:
>> > On Wed, 27 Nov 2019, Daniel Vetter <daniel@ffwll.ch> wrote:
>> > > On Wed, Nov 27, 2019 at 07:17:41PM +0100, Daniel Vetter wrote:
>> > >> On Wed, Nov 27, 2019 at 06:31:57PM +0200, Jani Nikula wrote:
>> > >> > Modifying fb_ops directly to override fb_mmap with fb_deferred_io_mmap
>> > >> > and then resetting it to NULL afterwards causes problems all over the
>> > >> > place. First, it prevents making the fbops member of struct fb_info a
>> > >> > const pointer, which means we can't make struct fb_ops const
>> > >> > anywhere. Second, a few places have to go out of their way to restore
>> > >> > the original fb_mmap pointer that gets reset to NULL.
>> > >> > 
>> > >> > Preserve the passed in fb_ops by making a copy of it and modifying that
>> > >> > instead. Add a deferred_io_private member to struct fb_info to store the
>> > >> > pointer to the old fb_ops, and restore that at cleanup.
>> > >> > 
>> > >> > Cc: Jaya Kumar <jayalk@intworks.biz>
>> > >> > Cc: linux-fbdev@vger.kernel.org
>> > >> > Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> > >> > 
>> > >> > ---
>> > >> > 
>> > >> > Note: If the approach is acceptable, we'll also need to handle the error
>> > >> > returns on memory allocation failures at fb_deferred_io_init() call
>> > >> > sites. There are 13.
>> > >> 
>> > >> it's fbdev defio, I think we can do worse with less effort. Just embed a
>> > >> copy of fb_ops into fb_info, and use that, and tada! no memory allocation
>> > >> needed :-)
>> > >> 
>> > >> I'd totally r-b that patch.
>> > >> 
>> > >> Or do what Ville suggested, add an fb_info->fbdefio.enabled, set that in
>> > >> the _init function and in fb_mmap call fb_deferred_io_mmap for that case
>> > >> instead of the driver's fb_ops->fb_mmap. There's only one caller of that
>> > >> in the entire tree, in fbmem.c. Also, we could/should nuke the
>> > >> EXPORT_SYMBOL(fb_deferred_io_mmap) I think.
>> > >
>> > > I just realized that fb_info->fbdefio is a pointer, so this would be
>> > > really simple to pull off I think.
>> > 
>> > Heh, having a
>> > 
>> > 	int (*fb_deferred_io_mmap)(struct fb_info *, struct vm_area_struct *);
>> > 
>> > member in struct fb_info, and using that in fbmem.c if non-NULL, was
>> > actually my first idea. I didn't think it was particularly pretty, but
>> > if we don't care about aesthetics...
>> > 
>> > Would you like that instead of the patch at hand?
>> 
>> 
>> diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
>> index 82c20c6047b0..9275c6bd71da 100644
>> --- a/drivers/video/fbdev/core/fb_defio.c
>> +++ b/drivers/video/fbdev/core/fb_defio.c
>> @@ -206,13 +206,11 @@ void fb_deferred_io_init(struct fb_info *info)
>>  
>>  	BUG_ON(!fbdefio);
>>  	mutex_init(&fbdefio->lock);
>> -	info->fbops->fb_mmap = fb_deferred_io_mmap;
>>  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
>>  	INIT_LIST_HEAD(&fbdefio->pagelist);
>>  	if (fbdefio->delay = 0) /* set a default of 1 s */
>>  		fbdefio->delay = HZ;
>>  }
>> -EXPORT_SYMBOL_GPL(fb_deferred_io_init);
>>  
>>  void fb_deferred_io_open(struct fb_info *info,
>>  			 struct inode *inode,
>> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
>> index 86b06a599f96..6af627f281c3 100644
>> --- a/drivers/video/fbdev/core/fbmem.c
>> +++ b/drivers/video/fbdev/core/fbmem.c
>> @@ -1341,7 +1341,16 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
>>  		return -ENODEV;
>>  	fb = info->fbops;
>>  	mutex_lock(&info->mm_lock);
>> -	if (fb->fb_mmap) {
>> +	if (fb->fbdefio) {
>> +		/*
>> +		 * The framebuffer needs to be accessed decrypted, be sure
>> +		 * SME protection is removed ahead of the call
>> +		 */
>> +		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
>> +		res = fb_deferred_io_mmap(info, vma);
>> +		mutex_unlock(&info->mm_lock);
>> +		return res;
>> +	} else if (fb->fb_mmap) {
>>  		int res;
>>  
>>  		/*
>> 
>> Is what I was thinking off as the pretty solution. Add an explicit
>> fb_info->fbdefio_enabled boolean if you don't feel like auditing all the
>> drivers for whether they really call defio_init() every time they assign
>> something to that pointer. A quick scan brought some nasties to light in
>> that area.
>
> Correction, brain wasn't awake yet, I've done the audit and the above diff
> should work afaict.

It just felt sketchy to me to depend on that pointer being set as the
decider, independent of defio init. But if you think that's the way to
go, I'm not going to argue. I'll bet it won't go unnoticed if
fb_deferred_io_mmap() gets called without the init. ;)

BR,
Jani.



> -Daniel
>
>> 
>> I think a function pointer here is pointless because we clearly don't need
>> it, and with all the panic around function pointers a direct call feels
>> much better :-)
>> -Daniel
>> 
>> > 
>> > BR,
>> > Jani.
>> > 
>> > 
>> > > -Daniel
>> > >
>> > >> 
>> > >> That version would also get my r-b stamp. So up to you what you prefer.
>> > >> -Daniel
>> > >> 
>> > >> > ---
>> > >> >  drivers/video/fbdev/core/fb_defio.c | 25 ++++++++++++++++++++++---
>> > >> >  include/linux/fb.h                  |  3 ++-
>> > >> >  2 files changed, 24 insertions(+), 4 deletions(-)
>> > >> > 
>> > >> > diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
>> > >> > index 82c20c6047b0..36697844c1e0 100644
>> > >> > --- a/drivers/video/fbdev/core/fb_defio.c
>> > >> > +++ b/drivers/video/fbdev/core/fb_defio.c
>> > >> > @@ -200,13 +200,23 @@ static void fb_deferred_io_work(struct work_struct *work)
>> > >> >  	mutex_unlock(&fbdefio->lock);
>> > >> >  }
>> > >> >  
>> > >> > -void fb_deferred_io_init(struct fb_info *info)
>> > >> > +int fb_deferred_io_init(struct fb_info *info)
>> > >> >  {
>> > >> >  	struct fb_deferred_io *fbdefio = info->fbdefio;
>> > >> > +	struct fb_ops *fbops;
>> > >> >  
>> > >> >  	BUG_ON(!fbdefio);
>> > >> > +
>> > >> > +	fbops = kmemdup(info->fbops, sizeof(*fbops), GFP_KERNEL);
>> > >> > +	if (!fbops)
>> > >> > +		return -ENOMEM;
>> > >> > +
>> > >> > +	fbops->fb_mmap = fb_deferred_io_mmap;
>> > >> > +	info->deferred_io_private = info->fbops;
>> > >> > +	info->fbops = fbops;
>> > >> > +
>> > >> >  	mutex_init(&fbdefio->lock);
>> > >> > -	info->fbops->fb_mmap = fb_deferred_io_mmap;
>> > >> > +
>> > >> >  	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
>> > >> >  	INIT_LIST_HEAD(&fbdefio->pagelist);
>> > >> >  	if (fbdefio->delay = 0) /* set a default of 1 s */
>> > >> > @@ -229,6 +239,12 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>> > >> >  	int i;
>> > >> >  
>> > >> >  	BUG_ON(!fbdefio);
>> > >> > +
>> > >> > +	/* sanity check against misuse */
>> > >> > +	if (WARN_ON(!info->deferred_io_private ||
>> > >> > +		    info->fbops->fb_mmap != fb_deferred_io_mmap))
>> > >> > +		return;
>> > >> > +
>> > >> >  	cancel_delayed_work_sync(&info->deferred_work);
>> > >> >  
>> > >> >  	/* clear out the mapping that we setup */
>> > >> > @@ -237,7 +253,10 @@ void fb_deferred_io_cleanup(struct fb_info *info)
>> > >> >  		page->mapping = NULL;
>> > >> >  	}
>> > >> >  
>> > >> > -	info->fbops->fb_mmap = NULL;
>> > >> > +	kfree(info->fbops);
>> > >> > +	info->fbops = info->deferred_io_private;
>> > >> > +	info->deferred_io_private = NULL;
>> > >> > +
>> > >> >  	mutex_destroy(&fbdefio->lock);
>> > >> >  }
>> > >> >  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
>> > >> > diff --git a/include/linux/fb.h b/include/linux/fb.h
>> > >> > index a6ad528990de..65f2abd47745 100644
>> > >> > --- a/include/linux/fb.h
>> > >> > +++ b/include/linux/fb.h
>> > >> > @@ -470,6 +470,7 @@ struct fb_info {
>> > >> >  #ifdef CONFIG_FB_DEFERRED_IO
>> > >> >  	struct delayed_work deferred_work;
>> > >> >  	struct fb_deferred_io *fbdefio;
>> > >> > +	void *deferred_io_private;
>> > >> >  #endif
>> > >> >  
>> > >> >  	struct fb_ops *fbops;
>> > >> > @@ -658,7 +659,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
>> > >> >  
>> > >> >  /* drivers/video/fb_defio.c */
>> > >> >  int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
>> > >> > -extern void fb_deferred_io_init(struct fb_info *info);
>> > >> > +extern int fb_deferred_io_init(struct fb_info *info);
>> > >> >  extern void fb_deferred_io_open(struct fb_info *info,
>> > >> >  				struct inode *inode,
>> > >> >  				struct file *file);
>> > >> > -- 
>> > >> > 2.20.1
>> > >> > 
>> > >> > _______________________________________________
>> > >> > Intel-gfx mailing list
>> > >> > Intel-gfx@lists.freedesktop.org
>> > >> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> > >> 
>> > >> -- 
>> > >> Daniel Vetter
>> > >> Software Engineer, Intel Corporation
>> > >> http://blog.ffwll.ch
>> > 
>> > -- 
>> > Jani Nikula, Intel Open Source Graphics Center
>> 
>> -- 
>> Daniel Vetter
>> Software Engineer, Intel Corporation
>> http://blog.ffwll.ch

-- 
Jani Nikula, Intel Open Source Graphics Center

[PATCH 02/13] drm/fb-helper: don't preserve fb_ops across deferred IO use

[Jani Nikula]

Deferred IO now preserves the fb_ops.

Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 0c088ea70ad0..a5a2a538d085 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1954,7 +1954,6 @@ static int drm_fbdev_fb_release(struct fb_info *info, int user)
 static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
 {
 	struct fb_info *fbi = fb_helper->fbdev;
-	struct fb_ops *fbops = NULL;
 	void *shadow = NULL;
 
 	if (!fb_helper->dev)
@@ -1963,15 +1962,11 @@ static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
 	if (fbi && fbi->fbdefio) {
 		fb_deferred_io_cleanup(fbi);
 		shadow = fbi->screen_buffer;
-		fbops = fbi->fbops;
 	}
 
 	drm_fb_helper_fini(fb_helper);
 
-	if (shadow) {
-		vfree(shadow);
-		kfree(fbops);
-	}
+	vfree(shadow);
 
 	drm_client_framebuffer_delete(fb_helper->buffer);
 }
@@ -2062,23 +2057,14 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
 	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
 
 	if (drm_fbdev_use_shadow_fb(fb_helper)) {
-		struct fb_ops *fbops;
 		void *shadow;
 
-		/*
-		 * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
-		 * instance version is necessary.
-		 */
-		fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
 		shadow = vzalloc(fbi->screen_size);
-		if (!fbops || !shadow) {
-			kfree(fbops);
+		if (!shadow) {
 			vfree(shadow);
 			return -ENOMEM;
 		}
 
-		*fbops = *fbi->fbops;
-		fbi->fbops = fbops;
 		fbi->screen_buffer = shadow;
 		fbi->fbdefio = &drm_fbdev_defio;
 
-- 
2.20.1

Re: [Intel-gfx] [PATCH 02/13] drm/fb-helper: don't preserve fb_ops across deferred IO use

[Daniel Vetter]

On Wed, Nov 27, 2019 at 06:31:58PM +0200, Jani Nikula wrote:
> Deferred IO now preserves the fb_ops.
> 
> Cc: Noralf Trønnes <noralf@tronnes.org>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
>  drivers/gpu/drm/drm_fb_helper.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 0c088ea70ad0..a5a2a538d085 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -1954,7 +1954,6 @@ static int drm_fbdev_fb_release(struct fb_info *info, int user)
>  static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>  {
>  	struct fb_info *fbi = fb_helper->fbdev;
> -	struct fb_ops *fbops = NULL;
>  	void *shadow = NULL;
>  
>  	if (!fb_helper->dev)
> @@ -1963,15 +1962,11 @@ static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>  	if (fbi && fbi->fbdefio) {
>  		fb_deferred_io_cleanup(fbi);
>  		shadow = fbi->screen_buffer;
> -		fbops = fbi->fbops;
>  	}
>  
>  	drm_fb_helper_fini(fb_helper);
>  
> -	if (shadow) {
> -		vfree(shadow);
> -		kfree(fbops);
> -	}
> +	vfree(shadow);
>  
>  	drm_client_framebuffer_delete(fb_helper->buffer);
>  }
> @@ -2062,23 +2057,14 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>  	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
>  
>  	if (drm_fbdev_use_shadow_fb(fb_helper)) {
> -		struct fb_ops *fbops;
>  		void *shadow;
>  
> -		/*
> -		 * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
> -		 * instance version is necessary.
> -		 */
> -		fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
>  		shadow = vzalloc(fbi->screen_size);
> -		if (!fbops || !shadow) {
> -			kfree(fbops);
> +		if (!shadow) {
>  			vfree(shadow);
>  			return -ENOMEM;
>  		}
>  
> -		*fbops = *fbi->fbops;
> -		fbi->fbops = fbops;
>  		fbi->screen_buffer = shadow;
>  		fbi->fbdefio = &drm_fbdev_defio;
>  
> -- 
> 2.20.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 02/13] drm/fb-helper: don't preserve fb_ops across deferred IO use

[Noralf Trønnes]

Den 27.11.2019 17.31, skrev Jani Nikula:
> Deferred IO now preserves the fb_ops.
> 
> Cc: Noralf Trønnes <noralf@tronnes.org>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/drm_fb_helper.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 0c088ea70ad0..a5a2a538d085 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -1954,7 +1954,6 @@ static int drm_fbdev_fb_release(struct fb_info *info, int user)
>  static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>  {
>  	struct fb_info *fbi = fb_helper->fbdev;
> -	struct fb_ops *fbops = NULL;
>  	void *shadow = NULL;
>  
>  	if (!fb_helper->dev)
> @@ -1963,15 +1962,11 @@ static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>  	if (fbi && fbi->fbdefio) {
>  		fb_deferred_io_cleanup(fbi);
>  		shadow = fbi->screen_buffer;
> -		fbops = fbi->fbops;
>  	}
>  
>  	drm_fb_helper_fini(fb_helper);
>  
> -	if (shadow) {
> -		vfree(shadow);
> -		kfree(fbops);
> -	}
> +	vfree(shadow);
>  
>  	drm_client_framebuffer_delete(fb_helper->buffer);
>  }
> @@ -2062,23 +2057,14 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>  	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
>  
>  	if (drm_fbdev_use_shadow_fb(fb_helper)) {
> -		struct fb_ops *fbops;
>  		void *shadow;
>  
> -		/*
> -		 * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
> -		 * instance version is necessary.
> -		 */
> -		fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
>  		shadow = vzalloc(fbi->screen_size);
> -		if (!fbops || !shadow) {
> -			kfree(fbops);
> +		if (!shadow) {
>  			vfree(shadow);

This vfree can is a no-op now and can be dropped. With that:

Reviewed-by: Noralf Trønnes <noralf@tronnes.org>

>  			return -ENOMEM;
>  		}
>  
> -		*fbops = *fbi->fbops;
> -		fbi->fbops = fbops;
>  		fbi->screen_buffer = shadow;
>  		fbi->fbdefio = &drm_fbdev_defio;
>  
> 

Re: [Intel-gfx] [PATCH 02/13] drm/fb-helper: don't preserve fb_ops across deferred IO use

[Jani Nikula]

On Thu, 28 Nov 2019, Noralf Trønnes <noralf@tronnes.org> wrote:
> Den 27.11.2019 17.31, skrev Jani Nikula:
>> Deferred IO now preserves the fb_ops.
>> 
>> Cc: Noralf Trønnes <noralf@tronnes.org>
>> Cc: dri-devel@lists.freedesktop.org
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> ---
>>  drivers/gpu/drm/drm_fb_helper.c | 18 ++----------------
>>  1 file changed, 2 insertions(+), 16 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>> index 0c088ea70ad0..a5a2a538d085 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -1954,7 +1954,6 @@ static int drm_fbdev_fb_release(struct fb_info *info, int user)
>>  static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>>  {
>>  	struct fb_info *fbi = fb_helper->fbdev;
>> -	struct fb_ops *fbops = NULL;
>>  	void *shadow = NULL;
>>  
>>  	if (!fb_helper->dev)
>> @@ -1963,15 +1962,11 @@ static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>>  	if (fbi && fbi->fbdefio) {
>>  		fb_deferred_io_cleanup(fbi);
>>  		shadow = fbi->screen_buffer;
>> -		fbops = fbi->fbops;
>>  	}
>>  
>>  	drm_fb_helper_fini(fb_helper);
>>  
>> -	if (shadow) {
>> -		vfree(shadow);
>> -		kfree(fbops);
>> -	}
>> +	vfree(shadow);
>>  
>>  	drm_client_framebuffer_delete(fb_helper->buffer);
>>  }
>> @@ -2062,23 +2057,14 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>>  	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
>>  
>>  	if (drm_fbdev_use_shadow_fb(fb_helper)) {
>> -		struct fb_ops *fbops;
>>  		void *shadow;
>>  
>> -		/*
>> -		 * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
>> -		 * instance version is necessary.
>> -		 */
>> -		fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
>>  		shadow = vzalloc(fbi->screen_size);
>> -		if (!fbops || !shadow) {
>> -			kfree(fbops);
>> +		if (!shadow) {
>>  			vfree(shadow);
>
> This vfree can is a no-op now and can be dropped. With that:

D'oh!

With that I think I'd also drop the shadow local variable and assign to
fbi->screen_buffer directly. Fine with that?

Thanks.

BR,
Jani.

>
> Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
>
>>  			return -ENOMEM;
>>  		}
>>  
>> -		*fbops = *fbi->fbops;
>> -		fbi->fbops = fbops;
>>  		fbi->screen_buffer = shadow;
>>  		fbi->fbdefio = &drm_fbdev_defio;
>>  
>> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [Intel-gfx] [PATCH 02/13] drm/fb-helper: don't preserve fb_ops across deferred IO use

[Noralf Trønnes]

Den 28.11.2019 13.05, skrev Jani Nikula:
> On Thu, 28 Nov 2019, Noralf Trønnes <noralf@tronnes.org> wrote:
>> Den 27.11.2019 17.31, skrev Jani Nikula:
>>> Deferred IO now preserves the fb_ops.
>>>
>>> Cc: Noralf Trønnes <noralf@tronnes.org>
>>> Cc: dri-devel@lists.freedesktop.org
>>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>>> ---
>>>  drivers/gpu/drm/drm_fb_helper.c | 18 ++----------------
>>>  1 file changed, 2 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>>> index 0c088ea70ad0..a5a2a538d085 100644
>>> --- a/drivers/gpu/drm/drm_fb_helper.c
>>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>>> @@ -1954,7 +1954,6 @@ static int drm_fbdev_fb_release(struct fb_info *info, int user)
>>>  static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>>>  {
>>>  	struct fb_info *fbi = fb_helper->fbdev;
>>> -	struct fb_ops *fbops = NULL;
>>>  	void *shadow = NULL;
>>>  
>>>  	if (!fb_helper->dev)
>>> @@ -1963,15 +1962,11 @@ static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>>>  	if (fbi && fbi->fbdefio) {
>>>  		fb_deferred_io_cleanup(fbi);
>>>  		shadow = fbi->screen_buffer;
>>> -		fbops = fbi->fbops;
>>>  	}
>>>  
>>>  	drm_fb_helper_fini(fb_helper);
>>>  
>>> -	if (shadow) {
>>> -		vfree(shadow);
>>> -		kfree(fbops);
>>> -	}
>>> +	vfree(shadow);
>>>  
>>>  	drm_client_framebuffer_delete(fb_helper->buffer);
>>>  }
>>> @@ -2062,23 +2057,14 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>>>  	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
>>>  
>>>  	if (drm_fbdev_use_shadow_fb(fb_helper)) {
>>> -		struct fb_ops *fbops;
>>>  		void *shadow;
>>>  
>>> -		/*
>>> -		 * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
>>> -		 * instance version is necessary.
>>> -		 */
>>> -		fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
>>>  		shadow = vzalloc(fbi->screen_size);
>>> -		if (!fbops || !shadow) {
>>> -			kfree(fbops);
>>> +		if (!shadow) {
>>>  			vfree(shadow);
>>
>> This vfree can is a no-op now and can be dropped. With that:
> 
> D'oh!
> 
> With that I think I'd also drop the shadow local variable and assign to
> fbi->screen_buffer directly. Fine with that?

Sure, that's even better.

Noralf.

> 
> Thanks.
> 
> BR,
> Jani.
> 
>>
>> Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
>>
>>>  			return -ENOMEM;
>>>  		}
>>>  
>>> -		*fbops = *fbi->fbops;
>>> -		fbi->fbops = fbops;
>>>  		fbi->screen_buffer = shadow;
>>>  		fbi->fbdefio = &drm_fbdev_defio;
>>>  
>>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 

[PATCH 03/13] video: smscufx: don't restore fb_mmap after deferred IO cleanup

[Jani Nikula]

Deferred IO now preserves the fb_ops.

Cc: Steve Glendinning <steve.glendinning@shawell.net>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/video/fbdev/smscufx.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c
index 0e0f5bbfc5ef..e362d7da87fc 100644
--- a/drivers/video/fbdev/smscufx.c
+++ b/drivers/video/fbdev/smscufx.c
@@ -1170,7 +1170,6 @@ static int ufx_ops_release(struct fb_info *info, int user)
 		fb_deferred_io_cleanup(info);
 		kfree(info->fbdefio);
 		info->fbdefio = NULL;
-		info->fbops->fb_mmap = ufx_ops_mmap;
 	}
 
 	pr_debug("released /dev/fb%d user=%d count=%d",
-- 
2.20.1

Re: [Intel-gfx] [PATCH 03/13] video: smscufx: don't restore fb_mmap after deferred IO cleanup

[Daniel Vetter]

On Wed, Nov 27, 2019 at 06:31:59PM +0200, Jani Nikula wrote:
> Deferred IO now preserves the fb_ops.
> 
> Cc: Steve Glendinning <steve.glendinning@shawell.net>
> Cc: linux-fbdev@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/video/fbdev/smscufx.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c
> index 0e0f5bbfc5ef..e362d7da87fc 100644
> --- a/drivers/video/fbdev/smscufx.c
> +++ b/drivers/video/fbdev/smscufx.c
> @@ -1170,7 +1170,6 @@ static int ufx_ops_release(struct fb_info *info, int user)
>  		fb_deferred_io_cleanup(info);
>  		kfree(info->fbdefio);
>  		info->fbdefio = NULL;
> -		info->fbops->fb_mmap = ufx_ops_mmap;

Also totally pointless to restore this here, since if you have indeed
loaded the driver twice shit has hit the fan already. I guess that was for
the module option .... wtf.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

>  	}
>  
>  	pr_debug("released /dev/fb%d user=%d count=%d",
> -- 
> 2.20.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

[PATCH 04/13] video: udlfb: don't restore fb_mmap after deferred IO cleanup

[Jani Nikula]

Deferred IO now preserves the fb_ops.

Cc: Bernie Thompson <bernie@plugable.com>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/video/fbdev/udlfb.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
index fe373b63ddd6..07905d385949 100644
--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -1037,7 +1037,6 @@ static int dlfb_ops_release(struct fb_info *info, int user)
 		fb_deferred_io_cleanup(info);
 		kfree(info->fbdefio);
 		info->fbdefio = NULL;
-		info->fbops->fb_mmap = dlfb_ops_mmap;
 	}
 
 	dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count);
-- 
2.20.1

Re: [PATCH 04/13] video: udlfb: don't restore fb_mmap after deferred IO cleanup

[Daniel Vetter]

On Wed, Nov 27, 2019 at 06:32:00PM +0200, Jani Nikula wrote:
> Deferred IO now preserves the fb_ops.
> 
> Cc: Bernie Thompson <bernie@plugable.com>
> Cc: linux-fbdev@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Aside: I wonder whether we should start retiring all the fbdev drivers
which have kms drivers already ... you get fbdev for free with the latter.
-Daniel

> ---
>  drivers/video/fbdev/udlfb.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
> index fe373b63ddd6..07905d385949 100644
> --- a/drivers/video/fbdev/udlfb.c
> +++ b/drivers/video/fbdev/udlfb.c
> @@ -1037,7 +1037,6 @@ static int dlfb_ops_release(struct fb_info *info, int user)
>  		fb_deferred_io_cleanup(info);
>  		kfree(info->fbdefio);
>  		info->fbdefio = NULL;
> -		info->fbops->fb_mmap = dlfb_ops_mmap;
>  	}
>  
>  	dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count);
> -- 
> 2.20.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

[PATCH 05/13] video: fbdev: vesafb: modify the static fb_ops directly

[Jani Nikula]

Avoid modifying the fb_ops via info->fbops to let us make the pointer
const in the future.

Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/video/fbdev/vesafb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/video/fbdev/vesafb.c b/drivers/video/fbdev/vesafb.c
index d9c08f6c2155..a1fe24ea869b 100644
--- a/drivers/video/fbdev/vesafb.c
+++ b/drivers/video/fbdev/vesafb.c
@@ -447,15 +447,15 @@ static int vesafb_probe(struct platform_device *dev)
 	       vesafb_fix.smem_start, info->screen_base,
 	       size_remap/1024, size_total/1024);
 
+	if (!ypan)
+		vesafb_ops.fb_pan_display = NULL;
+
 	info->fbops = &vesafb_ops;
 	info->var = vesafb_defined;
 	info->fix = vesafb_fix;
 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE |
 		(ypan ? FBINFO_HWACCEL_YPAN : 0);
 
-	if (!ypan)
-		info->fbops->fb_pan_display = NULL;
-
 	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
 		err = -ENOMEM;
 		goto err;
-- 
2.20.1

Re: [PATCH 05/13] video: fbdev: vesafb: modify the static fb_ops directly

[Daniel Vetter]

On Wed, Nov 27, 2019 at 06:32:01PM +0200, Jani Nikula wrote:
> Avoid modifying the fb_ops via info->fbops to let us make the pointer
> const in the future.
> 
> Cc: linux-fbdev@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/video/fbdev/vesafb.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/video/fbdev/vesafb.c b/drivers/video/fbdev/vesafb.c
> index d9c08f6c2155..a1fe24ea869b 100644
> --- a/drivers/video/fbdev/vesafb.c
> +++ b/drivers/video/fbdev/vesafb.c
> @@ -447,15 +447,15 @@ static int vesafb_probe(struct platform_device *dev)
>  	       vesafb_fix.smem_start, info->screen_base,
>  	       size_remap/1024, size_total/1024);
>  
> +	if (!ypan)
> +		vesafb_ops.fb_pan_display = NULL;

vesafb at least has a guarantee that there's only ever one ...

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> +
>  	info->fbops = &vesafb_ops;
>  	info->var = vesafb_defined;
>  	info->fix = vesafb_fix;
>  	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE |
>  		(ypan ? FBINFO_HWACCEL_YPAN : 0);
>  
> -	if (!ypan)
> -		info->fbops->fb_pan_display = NULL;
> -
>  	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
>  		err = -ENOMEM;
>  		goto err;
> -- 
> 2.20.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

[PATCH 06/13] video: fbmem: use const pointer for fb_ops

[Jani Nikula]

Use const for fb_ops to let us make the info->fbops pointer const in the
future.

Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/video/fbdev/core/fbmem.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 86b06a599f96..003f494ccaba 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1079,7 +1079,7 @@ EXPORT_SYMBOL(fb_blank);
 static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
 			unsigned long arg)
 {
-	struct fb_ops *fb;
+	const struct fb_ops *fb;
 	struct fb_var_screeninfo var;
 	struct fb_fix_screeninfo fix;
 	struct fb_cmap cmap_from;
@@ -1292,7 +1292,7 @@ static long fb_compat_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg)
 {
 	struct fb_info *info = file_fb_info(file);
-	struct fb_ops *fb;
+	const struct fb_ops *fb;
 	long ret = -ENOIOCTLCMD;
 
 	if (!info)
@@ -1332,7 +1332,7 @@ static int
 fb_mmap(struct file *file, struct vm_area_struct * vma)
 {
 	struct fb_info *info = file_fb_info(file);
-	struct fb_ops *fb;
+	const struct fb_ops *fb;
 	unsigned long mmio_pgoff;
 	unsigned long start;
 	u32 len;
-- 
2.20.1

[PATCH 07/13] video: omapfb: use const pointer for fb_ops

[Jani Nikula]

Use const for fb_ops to let us make the info->fbops pointer const in the
future.

Cc: linux-fbdev@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/video/fbdev/omap/omapfb_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/omap/omapfb_main.c b/drivers/video/fbdev/omap/omapfb_main.c
index 702cca59bda1..e8a304f84ea8 100644
--- a/drivers/video/fbdev/omap/omapfb_main.c
+++ b/drivers/video/fbdev/omap/omapfb_main.c
@@ -1052,7 +1052,7 @@ static int omapfb_ioctl(struct fb_info *fbi, unsigned int cmd,
 {
 	struct omapfb_plane_struct *plane = fbi->par;
 	struct omapfb_device	*fbdev = plane->fbdev;
-	struct fb_ops		*ops = fbi->fbops;
+	const struct fb_ops *ops = fbi->fbops;
 	union {
 		struct omapfb_update_window	update_window;
 		struct omapfb_plane_info	plane_info;
-- 
2.20.1

[PATCH 08/13] video: fbdev: make fbops member of struct fb_info a const pointer

[Jani Nikula]

Now that we no longer modify the fbops, or hold non-const pointers to
it, we can make it const. With that, also deferred_io_private needs to
be const. After this, we can start making the fbops const all over the
place.

Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 include/linux/fb.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/fb.h b/include/linux/fb.h
index 65f2abd47745..efc5376c243a 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -470,10 +470,10 @@ struct fb_info {
 #ifdef CONFIG_FB_DEFERRED_IO
 	struct delayed_work deferred_work;
 	struct fb_deferred_io *fbdefio;
-	void *deferred_io_private;
+	const void *deferred_io_private;
 #endif
 
-	struct fb_ops *fbops;
+	const struct fb_ops *fbops;
 	struct device *device;		/* This is the parent */
 	struct device *dev;		/* This is this fb device */
 	int class_flag;                    /* private sysfs flags */
-- 
2.20.1

Re: [PATCH 08/13] video: fbdev: make fbops member of struct fb_info a const pointer

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 14728 bytes --]

Hi Jani,

I love your patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on v5.4 next-20191127]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Jani-Nikula/video-drm-constify-fbops-in-struct-fb_info/20191128-022047
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: x86_64-randconfig-s1-20191128 (attached as .config)
compiler: gcc-7 (Debian 7.4.0-14) 7.4.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/video/fbdev/uvesafb.c: In function 'uvesafb_init_info':
>> drivers/video/fbdev/uvesafb.c:1443:25: error: assignment of member 'fb_blank' in read-only object
      info->fbops->fb_blank = NULL;
                            ^
>> drivers/video/fbdev/uvesafb.c:1513:31: error: assignment of member 'fb_pan_display' in read-only object
      info->fbops->fb_pan_display = NULL;
                                  ^
--
   drivers/video/fbdev/mb862xx/mb862xxfb_accel.c: In function 'mb862xxfb_init_accel':
>> drivers/video/fbdev/mb862xx/mb862xxfb_accel.c:311:28: error: assignment of member 'fb_fillrect' in read-only object
      info->fbops->fb_fillrect = cfb_fillrect;
                               ^
>> drivers/video/fbdev/mb862xx/mb862xxfb_accel.c:312:28: error: assignment of member 'fb_copyarea' in read-only object
      info->fbops->fb_copyarea = cfb_copyarea;
                               ^
>> drivers/video/fbdev/mb862xx/mb862xxfb_accel.c:313:29: error: assignment of member 'fb_imageblit' in read-only object
      info->fbops->fb_imageblit = cfb_imageblit;
                                ^
   drivers/video/fbdev/mb862xx/mb862xxfb_accel.c:316:28: error: assignment of member 'fb_fillrect' in read-only object
      info->fbops->fb_fillrect = mb86290fb_fillrect;
                               ^
   drivers/video/fbdev/mb862xx/mb862xxfb_accel.c:317:28: error: assignment of member 'fb_copyarea' in read-only object
      info->fbops->fb_copyarea = mb86290fb_copyarea;
                               ^
   drivers/video/fbdev/mb862xx/mb862xxfb_accel.c:318:29: error: assignment of member 'fb_imageblit' in read-only object
      info->fbops->fb_imageblit = mb86290fb_imageblit;
                                ^
--
   drivers/video/fbdev/nvidia/nvidia.c: In function 'nvidiafb_set_par':
>> drivers/video/fbdev/nvidia/nvidia.c:663:29: error: assignment of member 'fb_imageblit' in read-only object
      info->fbops->fb_imageblit = nvidiafb_imageblit;
                                ^
>> drivers/video/fbdev/nvidia/nvidia.c:664:28: error: assignment of member 'fb_fillrect' in read-only object
      info->fbops->fb_fillrect = nvidiafb_fillrect;
                               ^
>> drivers/video/fbdev/nvidia/nvidia.c:665:28: error: assignment of member 'fb_copyarea' in read-only object
      info->fbops->fb_copyarea = nvidiafb_copyarea;
                               ^
>> drivers/video/fbdev/nvidia/nvidia.c:666:24: error: assignment of member 'fb_sync' in read-only object
      info->fbops->fb_sync = nvidiafb_sync;
                           ^
   drivers/video/fbdev/nvidia/nvidia.c:672:29: error: assignment of member 'fb_imageblit' in read-only object
      info->fbops->fb_imageblit = cfb_imageblit;
                                ^
   drivers/video/fbdev/nvidia/nvidia.c:673:28: error: assignment of member 'fb_fillrect' in read-only object
      info->fbops->fb_fillrect = cfb_fillrect;
                               ^
   drivers/video/fbdev/nvidia/nvidia.c:674:28: error: assignment of member 'fb_copyarea' in read-only object
      info->fbops->fb_copyarea = cfb_copyarea;
                               ^
   drivers/video/fbdev/nvidia/nvidia.c:675:24: error: assignment of member 'fb_sync' in read-only object
      info->fbops->fb_sync = NULL;
                           ^
   drivers/video/fbdev/nvidia/nvidia.c: In function 'nvidia_set_fbinfo':
>> drivers/video/fbdev/nvidia/nvidia.c:1168:29: error: assignment of member 'fb_cursor' in read-only object
         info->fbops->fb_cursor = NULL;
                                ^

vim +/fb_blank +1443 drivers/video/fbdev/uvesafb.c

8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1427  
48c68c4f1b5424 drivers/video/uvesafb.c       Greg Kroah-Hartman 2012-12-21  1428  static void uvesafb_init_info(struct fb_info *info, struct vbe_mode_ib *mode)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1429  {
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1430  	unsigned int size_vmode;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1431  	unsigned int size_remap;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1432  	unsigned int size_total;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1433  	struct uvesafb_par *par = info->par;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1434  	int i, h;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1435  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1436  	info->pseudo_palette = ((u8 *)info->par + sizeof(struct uvesafb_par));
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1437  	info->fix = uvesafb_fix;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1438  	info->fix.ypanstep = par->ypan ? 1 : 0;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1439  	info->fix.ywrapstep = (par->ypan > 1) ? 1 : 0;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1440  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1441  	/* Disable blanking if the user requested so. */
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1442  	if (!blank)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16 @1443  		info->fbops->fb_blank = NULL;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1444  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1445  	/*
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1446  	 * Find out how much IO memory is required for the mode with
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1447  	 * the highest resolution.
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1448  	 */
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1449  	size_remap = 0;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1450  	for (i = 0; i < par->vbe_modes_cnt; i++) {
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1451  		h = par->vbe_modes[i].bytes_per_scan_line *
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1452  					par->vbe_modes[i].y_res;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1453  		if (h > size_remap)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1454  			size_remap = h;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1455  	}
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1456  	size_remap *= 2;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1457  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1458  	/*
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1459  	 *   size_vmode -- that is the amount of memory needed for the
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1460  	 *                 used video mode, i.e. the minimum amount of
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1461  	 *                 memory we need.
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1462  	 */
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1463  	size_vmode = info->var.yres * mode->bytes_per_scan_line;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1464  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1465  	/*
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1466  	 *   size_total -- all video memory we have. Used for mtrr
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1467  	 *                 entries, resource allocation and bounds
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1468  	 *                 checking.
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1469  	 */
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1470  	size_total = par->vbe_ib.total_memory * 65536;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1471  	if (vram_total)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1472  		size_total = vram_total * 1024 * 1024;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1473  	if (size_total < size_vmode)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1474  		size_total = size_vmode;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1475  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1476  	/*
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1477  	 *   size_remap -- the amount of video memory we are going to
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1478  	 *                 use for vesafb.  With modern cards it is no
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1479  	 *                 option to simply use size_total as th
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1480  	 *                 wastes plenty of kernel address space.
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1481  	 */
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1482  	if (vram_remap)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1483  		size_remap = vram_remap * 1024 * 1024;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1484  	if (size_remap < size_vmode)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1485  		size_remap = size_vmode;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1486  	if (size_remap > size_total)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1487  		size_remap = size_total;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1488  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1489  	info->fix.smem_len = size_remap;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1490  	info->fix.smem_start = mode->phys_base_ptr;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1491  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1492  	/*
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1493  	 * We have to set yres_virtual here because when setup_var() was
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1494  	 * called, smem_len wasn't defined yet.
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1495  	 */
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1496  	info->var.yres_virtual = info->fix.smem_len /
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1497  				 mode->bytes_per_scan_line;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1498  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1499  	if (par->ypan && info->var.yres_virtual > info->var.yres) {
a8feae09110675 drivers/video/fbdev/uvesafb.c Joe Perches        2017-06-14  1500  		pr_info("scrolling: %s using protected mode interface, yres_virtual=%d\n",
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1501  			(par->ypan > 1) ? "ywrap" : "ypan",
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1502  			info->var.yres_virtual);
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1503  	} else {
a8feae09110675 drivers/video/fbdev/uvesafb.c Joe Perches        2017-06-14  1504  		pr_info("scrolling: redraw\n");
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1505  		info->var.yres_virtual = info->var.yres;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1506  		par->ypan = 0;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1507  	}
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1508  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1509  	info->flags = FBINFO_FLAG_DEFAULT |
1cc9fb6dbf915e drivers/video/uvesafb.c       Roel Kluin         2009-03-31  1510  			(par->ypan ? FBINFO_HWACCEL_YPAN : 0);
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1511  
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1512  	if (!par->ypan)
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16 @1513  		info->fbops->fb_pan_display = NULL;
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1514  }
8bdb3a2d7df48b drivers/video/uvesafb.c       Michal Januszewski 2007-10-16  1515  

:::::: The code at line 1443 was first introduced by commit
:::::: 8bdb3a2d7df48b861972c4bfb58490853a228f51 uvesafb: the driver core

:::::: TO: Michal Januszewski <spock@gentoo.org>
:::::: CC: Linus Torvalds <torvalds@woody.linux-foundation.org>

---
0-DAY kernel test infrastructure                 Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation

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Re: [PATCH 08/13] video: fbdev: make fbops member of struct fb_info a const pointer

[kbuild test robot]

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Hi Jani,

I love your patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on v5.4 next-20191127]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Jani-Nikula/video-drm-constify-fbops-in-struct-fb_info/20191128-022047
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: x86_64-allyesconfig (attached as .config)
compiler: gcc-7 (Debian 7.4.0-14) 7.4.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/gpu/drm/udl/udl_fb.c: In function 'udl_fb_release':
>> drivers/gpu/drm/udl/udl_fb.c:256:24: error: assignment of member 'fb_mmap' in read-only object
      info->fbops->fb_mmap = udl_fb_mmap;
                           ^

vim +/fb_mmap +256 drivers/gpu/drm/udl/udl_fb.c

5320918b9a8786 Dave Airlie     2010-12-15  240  
5320918b9a8786 Dave Airlie     2010-12-15  241  
5320918b9a8786 Dave Airlie     2010-12-15  242  /*
5320918b9a8786 Dave Airlie     2010-12-15  243   * Assumes caller is holding info->lock mutex (for open and release at least)
5320918b9a8786 Dave Airlie     2010-12-15  244   */
5320918b9a8786 Dave Airlie     2010-12-15  245  static int udl_fb_release(struct fb_info *info, int user)
5320918b9a8786 Dave Airlie     2010-12-15  246  {
5320918b9a8786 Dave Airlie     2010-12-15  247  	struct udl_fbdev *ufbdev = info->par;
5320918b9a8786 Dave Airlie     2010-12-15  248  
5320918b9a8786 Dave Airlie     2010-12-15  249  	ufbdev->fb_count--;
5320918b9a8786 Dave Airlie     2010-12-15  250  
2b721f20770ccb Daniel Vetter   2016-08-10  251  #ifdef CONFIG_DRM_FBDEV_EMULATION
5320918b9a8786 Dave Airlie     2010-12-15  252  	if ((ufbdev->fb_count == 0) && (info->fbdefio)) {
5320918b9a8786 Dave Airlie     2010-12-15  253  		fb_deferred_io_cleanup(info);
5320918b9a8786 Dave Airlie     2010-12-15  254  		kfree(info->fbdefio);
5320918b9a8786 Dave Airlie     2010-12-15  255  		info->fbdefio = NULL;
5320918b9a8786 Dave Airlie     2010-12-15 @256  		info->fbops->fb_mmap = udl_fb_mmap;
5320918b9a8786 Dave Airlie     2010-12-15  257  	}
2b721f20770ccb Daniel Vetter   2016-08-10  258  #endif
5320918b9a8786 Dave Airlie     2010-12-15  259  
90991209837ab6 Mikulas Patocka 2018-06-03  260  	pr_debug("released /dev/fb%d user=%d count=%d\n",
5320918b9a8786 Dave Airlie     2010-12-15  261  		info->node, user, ufbdev->fb_count);
5320918b9a8786 Dave Airlie     2010-12-15  262  
5320918b9a8786 Dave Airlie     2010-12-15  263  	return 0;
5320918b9a8786 Dave Airlie     2010-12-15  264  }
5320918b9a8786 Dave Airlie     2010-12-15  265  

:::::: The code at line 256 was first introduced by commit
:::::: 5320918b9a87865223fd6b228e530bf30bc64d9d drm/udl: initial UDL driver (v4)

:::::: TO: Dave Airlie <airlied@gmail.com>
:::::: CC: Dave Airlie <airlied@redhat.com>

---
0-DAY kernel test infrastructure                 Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation

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[PATCH 09/13] drm: constify fb ops across all drivers

[Jani Nikula]

Now that the fbops member of struct fb_info is const, we can start
making the ops const as well.

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c            | 2 +-
 drivers/gpu/drm/armada/armada_fbdev.c             | 2 +-
 drivers/gpu/drm/drm_fb_helper.c                   | 2 +-
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c         | 2 +-
 drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_fbdev.c | 2 +-
 drivers/gpu/drm/i915/display/intel_fbdev.c        | 2 +-
 drivers/gpu/drm/msm/msm_fbdev.c                   | 2 +-
 drivers/gpu/drm/nouveau/nouveau_fbcon.c           | 4 ++--
 drivers/gpu/drm/omapdrm/omap_fbdev.c              | 2 +-
 drivers/gpu/drm/radeon/radeon_fb.c                | 2 +-
 drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c     | 2 +-
 drivers/gpu/drm/tegra/fb.c                        | 2 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_fb.c                | 2 +-
 13 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c
index 143753d237e7..2672dc64a310 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c
@@ -69,7 +69,7 @@ amdgpufb_release(struct fb_info *info, int user)
 	return 0;
 }
 
-static struct fb_ops amdgpufb_ops = {
+static const struct fb_ops amdgpufb_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_open = amdgpufb_open,
diff --git a/drivers/gpu/drm/armada/armada_fbdev.c b/drivers/gpu/drm/armada/armada_fbdev.c
index 090cc0d699ae..ac8a78bfda03 100644
--- a/drivers/gpu/drm/armada/armada_fbdev.c
+++ b/drivers/gpu/drm/armada/armada_fbdev.c
@@ -16,7 +16,7 @@
 #include "armada_fb.h"
 #include "armada_gem.h"
 
-static /*const*/ struct fb_ops armada_fb_ops = {
+static const struct fb_ops armada_fb_ops = {
 	.owner		= THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_fillrect	= drm_fb_helper_cfb_fillrect,
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index a5a2a538d085..f895d6570923 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1997,7 +1997,7 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 		return -ENODEV;
 }
 
-static struct fb_ops drm_fbdev_fb_ops = {
+static const struct fb_ops drm_fbdev_fb_ops = {
 	.owner		= THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_open	= drm_fbdev_fb_open,
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index b0877b97291c..647a1fd1d815 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -60,7 +60,7 @@ static int exynos_drm_fb_mmap(struct fb_info *info,
 	return 0;
 }
 
-static struct fb_ops exynos_drm_fb_ops = {
+static const struct fb_ops exynos_drm_fb_ops = {
 	.owner		= THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_mmap        = exynos_drm_fb_mmap,
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_fbdev.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_fbdev.c
index b4c1cea051e8..1d15560ccb6e 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_fbdev.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_fbdev.c
@@ -38,7 +38,7 @@ static int hibmcfb_create_object(
 	return ret;
 }
 
-static struct fb_ops hibmc_drm_fb_ops = {
+static const struct fb_ops hibmc_drm_fb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = drm_fb_helper_check_var,
 	.fb_set_par = drm_fb_helper_set_par,
diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
index 48c960ca12fb..1e98e432c9fa 100644
--- a/drivers/gpu/drm/i915/display/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
@@ -100,7 +100,7 @@ static int intel_fbdev_pan_display(struct fb_var_screeninfo *var,
 	return ret;
 }
 
-static struct fb_ops intelfb_ops = {
+static const struct fb_ops intelfb_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_set_par = intel_fbdev_set_par,
diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
index cff198b2f470..db48867df47d 100644
--- a/drivers/gpu/drm/msm/msm_fbdev.c
+++ b/drivers/gpu/drm/msm/msm_fbdev.c
@@ -26,7 +26,7 @@ struct msm_fbdev {
 	struct drm_framebuffer *fb;
 };
 
-static struct fb_ops msm_fb_ops = {
+static const struct fb_ops msm_fb_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 
diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index f439f0a5b43a..0c5cdda3c336 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -203,7 +203,7 @@ nouveau_fbcon_release(struct fb_info *info, int user)
 	return 0;
 }
 
-static struct fb_ops nouveau_fbcon_ops = {
+static const struct fb_ops nouveau_fbcon_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_open = nouveau_fbcon_open,
@@ -214,7 +214,7 @@ static struct fb_ops nouveau_fbcon_ops = {
 	.fb_sync = nouveau_fbcon_sync,
 };
 
-static struct fb_ops nouveau_fbcon_sw_ops = {
+static const struct fb_ops nouveau_fbcon_sw_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_open = nouveau_fbcon_open,
diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
index 58f53946ee4d..b06e5cbfd03a 100644
--- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
+++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
@@ -70,7 +70,7 @@ static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
 	return drm_fb_helper_pan_display(var, fbi);
 }
 
-static struct fb_ops omap_fb_ops = {
+static const struct fb_ops omap_fb_ops = {
 	.owner = THIS_MODULE,
 
 	.fb_check_var	= drm_fb_helper_check_var,
diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c
index 2c564f4f3468..8a93fcce40e5 100644
--- a/drivers/gpu/drm/radeon/radeon_fb.c
+++ b/drivers/gpu/drm/radeon/radeon_fb.c
@@ -73,7 +73,7 @@ radeonfb_release(struct fb_info *info, int user)
 	return 0;
 }
 
-static struct fb_ops radeonfb_ops = {
+static const struct fb_ops radeonfb_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_open = radeonfb_open,
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c b/drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c
index 02be6c5ff857..521fe42ac5e2 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_fbdev.c
@@ -27,7 +27,7 @@ static int rockchip_fbdev_mmap(struct fb_info *info,
 	return rockchip_gem_mmap_buf(private->fbdev_bo, vma);
 }
 
-static struct fb_ops rockchip_drm_fbdev_ops = {
+static const struct fb_ops rockchip_drm_fbdev_ops = {
 	.owner		= THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_mmap	= rockchip_fbdev_mmap,
diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index 7cea89f29a5c..84f0e01e3428 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -192,7 +192,7 @@ static int tegra_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	return __tegra_gem_mmap(&bo->gem, vma);
 }
 
-static struct fb_ops tegra_fb_ops = {
+static const struct fb_ops tegra_fb_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_fillrect = drm_fb_helper_sys_fillrect,
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index ea29953e0b08..c59806d40e15 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
@@ -624,7 +624,7 @@ static int vmw_fb_set_par(struct fb_info *info)
 }
 
 
-static struct fb_ops vmw_fb_ops = {
+static const struct fb_ops vmw_fb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = vmw_fb_check_var,
 	.fb_set_par = vmw_fb_set_par,
-- 
2.20.1

[PATCH 10/13] video: constify fb ops across all drivers

[Jani Nikula]

Now that the fbops member of struct fb_info is const, we can star making
the ops const as well.

Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/video/fbdev/68328fb.c                  | 2 +-
 drivers/video/fbdev/acornfb.c                  | 2 +-
 drivers/video/fbdev/amba-clcd.c                | 2 +-
 drivers/video/fbdev/amifb.c                    | 2 +-
 drivers/video/fbdev/arcfb.c                    | 2 +-
 drivers/video/fbdev/arkfb.c                    | 2 +-
 drivers/video/fbdev/asiliantfb.c               | 2 +-
 drivers/video/fbdev/atmel_lcdfb.c              | 2 +-
 drivers/video/fbdev/aty/aty128fb.c             | 2 +-
 drivers/video/fbdev/aty/atyfb_base.c           | 2 +-
 drivers/video/fbdev/aty/radeon_base.c          | 2 +-
 drivers/video/fbdev/au1100fb.c                 | 2 +-
 drivers/video/fbdev/au1200fb.c                 | 2 +-
 drivers/video/fbdev/broadsheetfb.c             | 2 +-
 drivers/video/fbdev/bw2.c                      | 2 +-
 drivers/video/fbdev/carminefb.c                | 2 +-
 drivers/video/fbdev/cg14.c                     | 2 +-
 drivers/video/fbdev/cg3.c                      | 2 +-
 drivers/video/fbdev/cg6.c                      | 2 +-
 drivers/video/fbdev/chipsfb.c                  | 2 +-
 drivers/video/fbdev/cirrusfb.c                 | 2 +-
 drivers/video/fbdev/clps711x-fb.c              | 2 +-
 drivers/video/fbdev/cobalt_lcdfb.c             | 2 +-
 drivers/video/fbdev/controlfb.c                | 2 +-
 drivers/video/fbdev/cyber2000fb.c              | 2 +-
 drivers/video/fbdev/da8xx-fb.c                 | 2 +-
 drivers/video/fbdev/dnfb.c                     | 2 +-
 drivers/video/fbdev/efifb.c                    | 2 +-
 drivers/video/fbdev/ep93xx-fb.c                | 2 +-
 drivers/video/fbdev/fb-puv3.c                  | 2 +-
 drivers/video/fbdev/ffb.c                      | 2 +-
 drivers/video/fbdev/fm2fb.c                    | 2 +-
 drivers/video/fbdev/fsl-diu-fb.c               | 2 +-
 drivers/video/fbdev/g364fb.c                   | 2 +-
 drivers/video/fbdev/gbefb.c                    | 2 +-
 drivers/video/fbdev/geode/gx1fb_core.c         | 2 +-
 drivers/video/fbdev/geode/gxfb_core.c          | 2 +-
 drivers/video/fbdev/geode/lxfb_core.c          | 2 +-
 drivers/video/fbdev/goldfishfb.c               | 2 +-
 drivers/video/fbdev/grvga.c                    | 2 +-
 drivers/video/fbdev/gxt4500.c                  | 2 +-
 drivers/video/fbdev/hecubafb.c                 | 2 +-
 drivers/video/fbdev/hgafb.c                    | 2 +-
 drivers/video/fbdev/hitfb.c                    | 2 +-
 drivers/video/fbdev/hpfb.c                     | 2 +-
 drivers/video/fbdev/hyperv_fb.c                | 2 +-
 drivers/video/fbdev/i740fb.c                   | 2 +-
 drivers/video/fbdev/imsttfb.c                  | 2 +-
 drivers/video/fbdev/imxfb.c                    | 2 +-
 drivers/video/fbdev/intelfb/intelfbdrv.c       | 2 +-
 drivers/video/fbdev/kyro/fbdev.c               | 2 +-
 drivers/video/fbdev/leo.c                      | 2 +-
 drivers/video/fbdev/macfb.c                    | 2 +-
 drivers/video/fbdev/matrox/matroxfb_crtc2.c    | 2 +-
 drivers/video/fbdev/maxinefb.c                 | 2 +-
 drivers/video/fbdev/mb862xx/mb862xxfbdrv.c     | 2 +-
 drivers/video/fbdev/mbx/mbxfb.c                | 2 +-
 drivers/video/fbdev/metronomefb.c              | 2 +-
 drivers/video/fbdev/mmp/fb/mmpfb.c             | 2 +-
 drivers/video/fbdev/mx3fb.c                    | 5 +++--
 drivers/video/fbdev/neofb.c                    | 2 +-
 drivers/video/fbdev/nvidia/nvidia.c            | 2 +-
 drivers/video/fbdev/ocfb.c                     | 2 +-
 drivers/video/fbdev/offb.c                     | 2 +-
 drivers/video/fbdev/omap2/omapfb/omapfb-main.c | 2 +-
 drivers/video/fbdev/p9100.c                    | 2 +-
 drivers/video/fbdev/platinumfb.c               | 2 +-
 drivers/video/fbdev/pm2fb.c                    | 2 +-
 drivers/video/fbdev/pm3fb.c                    | 2 +-
 drivers/video/fbdev/pmag-aa-fb.c               | 2 +-
 drivers/video/fbdev/pmag-ba-fb.c               | 2 +-
 drivers/video/fbdev/pmagb-b-fb.c               | 2 +-
 drivers/video/fbdev/ps3fb.c                    | 2 +-
 drivers/video/fbdev/pvr2fb.c                   | 2 +-
 drivers/video/fbdev/pxa168fb.c                 | 2 +-
 drivers/video/fbdev/pxafb.c                    | 4 ++--
 drivers/video/fbdev/q40fb.c                    | 2 +-
 drivers/video/fbdev/riva/fbdev.c               | 2 +-
 drivers/video/fbdev/s3c-fb.c                   | 2 +-
 drivers/video/fbdev/s3c2410fb.c                | 2 +-
 drivers/video/fbdev/s3fb.c                     | 2 +-
 drivers/video/fbdev/sa1100fb.c                 | 2 +-
 drivers/video/fbdev/savage/savagefb_driver.c   | 2 +-
 drivers/video/fbdev/sh7760fb.c                 | 2 +-
 drivers/video/fbdev/sh_mobile_lcdcfb.c         | 4 ++--
 drivers/video/fbdev/simplefb.c                 | 2 +-
 drivers/video/fbdev/sis/sis_main.c             | 2 +-
 drivers/video/fbdev/skeletonfb.c               | 2 +-
 drivers/video/fbdev/sm712fb.c                  | 2 +-
 drivers/video/fbdev/ssd1307fb.c                | 2 +-
 drivers/video/fbdev/sstfb.c                    | 2 +-
 drivers/video/fbdev/stifb.c                    | 2 +-
 drivers/video/fbdev/sunxvr1000.c               | 2 +-
 drivers/video/fbdev/sunxvr2500.c               | 2 +-
 drivers/video/fbdev/sunxvr500.c                | 2 +-
 drivers/video/fbdev/tcx.c                      | 2 +-
 drivers/video/fbdev/tdfxfb.c                   | 2 +-
 drivers/video/fbdev/tgafb.c                    | 2 +-
 drivers/video/fbdev/tmiofb.c                   | 2 +-
 drivers/video/fbdev/tridentfb.c                | 2 +-
 drivers/video/fbdev/uvesafb.c                  | 2 +-
 drivers/video/fbdev/valkyriefb.c               | 2 +-
 drivers/video/fbdev/vfb.c                      | 2 +-
 drivers/video/fbdev/vga16fb.c                  | 2 +-
 drivers/video/fbdev/vt8500lcdfb.c              | 2 +-
 drivers/video/fbdev/vt8623fb.c                 | 2 +-
 drivers/video/fbdev/w100fb.c                   | 2 +-
 drivers/video/fbdev/wm8505fb.c                 | 2 +-
 drivers/video/fbdev/xen-fbfront.c              | 2 +-
 drivers/video/fbdev/xilinxfb.c                 | 2 +-
 110 files changed, 114 insertions(+), 113 deletions(-)

diff --git a/drivers/video/fbdev/68328fb.c b/drivers/video/fbdev/68328fb.c
index d48e96088f76..491fd5a82993 100644
--- a/drivers/video/fbdev/68328fb.c
+++ b/drivers/video/fbdev/68328fb.c
@@ -96,7 +96,7 @@ static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
 			   struct fb_info *info);
 static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma);
 
-static struct fb_ops mc68x328fb_ops = {
+static const struct fb_ops mc68x328fb_ops = {
 	.fb_check_var	= mc68x328fb_check_var,
 	.fb_set_par	= mc68x328fb_set_par,
 	.fb_setcolreg	= mc68x328fb_setcolreg,
diff --git a/drivers/video/fbdev/acornfb.c b/drivers/video/fbdev/acornfb.c
index 7cacae5a8797..a3af49529173 100644
--- a/drivers/video/fbdev/acornfb.c
+++ b/drivers/video/fbdev/acornfb.c
@@ -604,7 +604,7 @@ acornfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops acornfb_ops = {
+static const struct fb_ops acornfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= acornfb_check_var,
 	.fb_set_par	= acornfb_set_par,
diff --git a/drivers/video/fbdev/amba-clcd.c b/drivers/video/fbdev/amba-clcd.c
index 7de43be6ef2c..c3d55fc6c4e0 100644
--- a/drivers/video/fbdev/amba-clcd.c
+++ b/drivers/video/fbdev/amba-clcd.c
@@ -423,7 +423,7 @@ static int clcdfb_mmap(struct fb_info *info,
 	return ret;
 }
 
-static struct fb_ops clcdfb_ops = {
+static const struct fb_ops clcdfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= clcdfb_check_var,
 	.fb_set_par	= clcdfb_set_par,
diff --git a/drivers/video/fbdev/amifb.c b/drivers/video/fbdev/amifb.c
index 91ddc9602014..20e03e00b66d 100644
--- a/drivers/video/fbdev/amifb.c
+++ b/drivers/video/fbdev/amifb.c
@@ -3493,7 +3493,7 @@ static irqreturn_t amifb_interrupt(int irq, void *dev_id)
 }
 
 
-static struct fb_ops amifb_ops = {
+static const struct fb_ops amifb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= amifb_check_var,
 	.fb_set_par	= amifb_set_par,
diff --git a/drivers/video/fbdev/arcfb.c b/drivers/video/fbdev/arcfb.c
index a48741aab240..314ab82e01c0 100644
--- a/drivers/video/fbdev/arcfb.c
+++ b/drivers/video/fbdev/arcfb.c
@@ -491,7 +491,7 @@ static ssize_t arcfb_write(struct fb_info *info, const char __user *buf,
 	return err;
 }
 
-static struct fb_ops arcfb_ops = {
+static const struct fb_ops arcfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= arcfb_open,
 	.fb_read        = fb_sys_read,
diff --git a/drivers/video/fbdev/arkfb.c b/drivers/video/fbdev/arkfb.c
index f940e8b66b85..11ab9a153860 100644
--- a/drivers/video/fbdev/arkfb.c
+++ b/drivers/video/fbdev/arkfb.c
@@ -917,7 +917,7 @@ static int arkfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info
 
 /* Frame buffer operations */
 
-static struct fb_ops arkfb_ops = {
+static const struct fb_ops arkfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= arkfb_open,
 	.fb_release	= arkfb_release,
diff --git a/drivers/video/fbdev/asiliantfb.c b/drivers/video/fbdev/asiliantfb.c
index ea31054a28ca..3e006da47752 100644
--- a/drivers/video/fbdev/asiliantfb.c
+++ b/drivers/video/fbdev/asiliantfb.c
@@ -95,7 +95,7 @@ static int asiliantfb_set_par(struct fb_info *info);
 static int asiliantfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
 				u_int transp, struct fb_info *info);
 
-static struct fb_ops asiliantfb_ops = {
+static const struct fb_ops asiliantfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= asiliantfb_check_var,
 	.fb_set_par	= asiliantfb_set_par,
diff --git a/drivers/video/fbdev/atmel_lcdfb.c b/drivers/video/fbdev/atmel_lcdfb.c
index 5ff8e0320d95..d567f5d56c13 100644
--- a/drivers/video/fbdev/atmel_lcdfb.c
+++ b/drivers/video/fbdev/atmel_lcdfb.c
@@ -824,7 +824,7 @@ static int atmel_lcdfb_blank(int blank_mode, struct fb_info *info)
 	return ((blank_mode = FB_BLANK_NORMAL) ? 1 : 0);
 }
 
-static struct fb_ops atmel_lcdfb_ops = {
+static const struct fb_ops atmel_lcdfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= atmel_lcdfb_check_var,
 	.fb_set_par	= atmel_lcdfb_set_par,
diff --git a/drivers/video/fbdev/aty/aty128fb.c b/drivers/video/fbdev/aty/aty128fb.c
index fc1e45d44719..d7e41c8dd533 100644
--- a/drivers/video/fbdev/aty/aty128fb.c
+++ b/drivers/video/fbdev/aty/aty128fb.c
@@ -509,7 +509,7 @@ static void aty128_bl_set_power(struct fb_info *info, int power);
 			  (readb(bios + (v) + 3) << 24))
 
 
-static struct fb_ops aty128fb_ops = {
+static const struct fb_ops aty128fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= aty128fb_check_var,
 	.fb_set_par	= aty128fb_set_par,
diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
index 6dda5d885a03..9c57370596f1 100644
--- a/drivers/video/fbdev/aty/atyfb_base.c
+++ b/drivers/video/fbdev/aty/atyfb_base.c
@@ -280,7 +280,7 @@ static const struct fb_videomode defmode = {
 	0, FB_VMODE_NONINTERLACED
 };
 
-static struct fb_ops atyfb_ops = {
+static const struct fb_ops atyfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= atyfb_open,
 	.fb_release	= atyfb_release,
diff --git a/drivers/video/fbdev/aty/radeon_base.c b/drivers/video/fbdev/aty/radeon_base.c
index 4ca07866f2f6..3af00e3b965e 100644
--- a/drivers/video/fbdev/aty/radeon_base.c
+++ b/drivers/video/fbdev/aty/radeon_base.c
@@ -1965,7 +1965,7 @@ static int radeonfb_set_par(struct fb_info *info)
 }
 
 
-static struct fb_ops radeonfb_ops = {
+static const struct fb_ops radeonfb_ops = {
 	.owner			= THIS_MODULE,
 	.fb_check_var		= radeonfb_check_var,
 	.fb_set_par		= radeonfb_set_par,
diff --git a/drivers/video/fbdev/au1100fb.c b/drivers/video/fbdev/au1100fb.c
index 99941ae1f3a1..37a6512feda0 100644
--- a/drivers/video/fbdev/au1100fb.c
+++ b/drivers/video/fbdev/au1100fb.c
@@ -348,7 +348,7 @@ int au1100fb_fb_mmap(struct fb_info *fbi, struct vm_area_struct *vma)
 			fbdev->fb_len);
 }
 
-static struct fb_ops au1100fb_ops +static const struct fb_ops au1100fb_ops  {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= au1100fb_fb_setcolreg,
diff --git a/drivers/video/fbdev/au1200fb.c b/drivers/video/fbdev/au1200fb.c
index 265d3b45efd0..c00e01a17368 100644
--- a/drivers/video/fbdev/au1200fb.c
+++ b/drivers/video/fbdev/au1200fb.c
@@ -1483,7 +1483,7 @@ static int au1200fb_ioctl(struct fb_info *info, unsigned int cmd,
 }
 
 
-static struct fb_ops au1200fb_fb_ops = {
+static const struct fb_ops au1200fb_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= au1200fb_fb_check_var,
 	.fb_set_par	= au1200fb_fb_set_par,
diff --git a/drivers/video/fbdev/broadsheetfb.c b/drivers/video/fbdev/broadsheetfb.c
index d6ba348deb9f..fd66f4d4a621 100644
--- a/drivers/video/fbdev/broadsheetfb.c
+++ b/drivers/video/fbdev/broadsheetfb.c
@@ -1048,7 +1048,7 @@ static ssize_t broadsheetfb_write(struct fb_info *info, const char __user *buf,
 	return (err) ? err : count;
 }
 
-static struct fb_ops broadsheetfb_ops = {
+static const struct fb_ops broadsheetfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_read        = fb_sys_read,
 	.fb_write	= broadsheetfb_write,
diff --git a/drivers/video/fbdev/bw2.c b/drivers/video/fbdev/bw2.c
index 436f10f3d375..0d9a6bb57a09 100644
--- a/drivers/video/fbdev/bw2.c
+++ b/drivers/video/fbdev/bw2.c
@@ -37,7 +37,7 @@ static int bw2_ioctl(struct fb_info *, unsigned int, unsigned long);
  *  Frame buffer operations
  */
 
-static struct fb_ops bw2_ops = {
+static const struct fb_ops bw2_ops = {
 	.owner			= THIS_MODULE,
 	.fb_blank		= bw2_blank,
 	.fb_fillrect		= cfb_fillrect,
diff --git a/drivers/video/fbdev/carminefb.c b/drivers/video/fbdev/carminefb.c
index 9f3be0258623..bf3f2a9598b1 100644
--- a/drivers/video/fbdev/carminefb.c
+++ b/drivers/video/fbdev/carminefb.c
@@ -527,7 +527,7 @@ static int init_hardware(struct carmine_hw *hw)
 	return 0;
 }
 
-static struct fb_ops carminefb_ops = {
+static const struct fb_ops carminefb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_fillrect	= cfb_fillrect,
 	.fb_copyarea	= cfb_copyarea,
diff --git a/drivers/video/fbdev/cg14.c b/drivers/video/fbdev/cg14.c
index d80d99db3a46..a620b51cf7d0 100644
--- a/drivers/video/fbdev/cg14.c
+++ b/drivers/video/fbdev/cg14.c
@@ -39,7 +39,7 @@ static int cg14_pan_display(struct fb_var_screeninfo *, struct fb_info *);
  *  Frame buffer operations
  */
 
-static struct fb_ops cg14_ops = {
+static const struct fb_ops cg14_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= cg14_setcolreg,
 	.fb_pan_display		= cg14_pan_display,
diff --git a/drivers/video/fbdev/cg3.c b/drivers/video/fbdev/cg3.c
index 09f616dddfd7..77f6470ce665 100644
--- a/drivers/video/fbdev/cg3.c
+++ b/drivers/video/fbdev/cg3.c
@@ -39,7 +39,7 @@ static int cg3_ioctl(struct fb_info *, unsigned int, unsigned long);
  *  Frame buffer operations
  */
 
-static struct fb_ops cg3_ops = {
+static const struct fb_ops cg3_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= cg3_setcolreg,
 	.fb_blank		= cg3_blank,
diff --git a/drivers/video/fbdev/cg6.c b/drivers/video/fbdev/cg6.c
index d5888aecc2fb..a1c68cd48d7e 100644
--- a/drivers/video/fbdev/cg6.c
+++ b/drivers/video/fbdev/cg6.c
@@ -44,7 +44,7 @@ static int cg6_pan_display(struct fb_var_screeninfo *, struct fb_info *);
  *  Frame buffer operations
  */
 
-static struct fb_ops cg6_ops = {
+static const struct fb_ops cg6_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= cg6_setcolreg,
 	.fb_blank		= cg6_blank,
diff --git a/drivers/video/fbdev/chipsfb.c b/drivers/video/fbdev/chipsfb.c
index f4dc320dcafe..998067b701fa 100644
--- a/drivers/video/fbdev/chipsfb.c
+++ b/drivers/video/fbdev/chipsfb.c
@@ -79,7 +79,7 @@ static int chipsfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
 			     u_int transp, struct fb_info *info);
 static int chipsfb_blank(int blank, struct fb_info *info);
 
-static struct fb_ops chipsfb_ops = {
+static const struct fb_ops chipsfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= chipsfb_check_var,
 	.fb_set_par	= chipsfb_set_par,
diff --git a/drivers/video/fbdev/cirrusfb.c b/drivers/video/fbdev/cirrusfb.c
index e4ce5667b125..c3a3e344cee3 100644
--- a/drivers/video/fbdev/cirrusfb.c
+++ b/drivers/video/fbdev/cirrusfb.c
@@ -1956,7 +1956,7 @@ static void cirrusfb_zorro_unmap(struct fb_info *info)
 #endif /* CONFIG_ZORRO */
 
 /* function table of the above functions */
-static struct fb_ops cirrusfb_ops = {
+static const struct fb_ops cirrusfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= cirrusfb_open,
 	.fb_release	= cirrusfb_release,
diff --git a/drivers/video/fbdev/clps711x-fb.c b/drivers/video/fbdev/clps711x-fb.c
index cabbc721f894..c5d15c6db287 100644
--- a/drivers/video/fbdev/clps711x-fb.c
+++ b/drivers/video/fbdev/clps711x-fb.c
@@ -153,7 +153,7 @@ static int clps711x_fb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops clps711x_fb_ops = {
+static const struct fb_ops clps711x_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= clps711x_fb_setcolreg,
 	.fb_check_var	= clps711x_fb_check_var,
diff --git a/drivers/video/fbdev/cobalt_lcdfb.c b/drivers/video/fbdev/cobalt_lcdfb.c
index 544946901e8b..5f8b6324d2e8 100644
--- a/drivers/video/fbdev/cobalt_lcdfb.c
+++ b/drivers/video/fbdev/cobalt_lcdfb.c
@@ -269,7 +269,7 @@ static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
 	return 0;
 }
 
-static struct fb_ops cobalt_lcd_fbops = {
+static const struct fb_ops cobalt_lcd_fbops = {
 	.owner		= THIS_MODULE,
 	.fb_read	= cobalt_lcdfb_read,
 	.fb_write	= cobalt_lcdfb_write,
diff --git a/drivers/video/fbdev/controlfb.c b/drivers/video/fbdev/controlfb.c
index 9a680ef3ffc3..38b61cdb5ca4 100644
--- a/drivers/video/fbdev/controlfb.c
+++ b/drivers/video/fbdev/controlfb.c
@@ -157,7 +157,7 @@ static int default_vmode __initdata = VMODE_NVRAM;
 static int default_cmode __initdata = CMODE_NVRAM;
 
 
-static struct fb_ops controlfb_ops = {
+static const struct fb_ops controlfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= controlfb_check_var,
 	.fb_set_par	= controlfb_set_par,
diff --git a/drivers/video/fbdev/cyber2000fb.c b/drivers/video/fbdev/cyber2000fb.c
index 3a2d9ff0aa42..460826a7ad55 100644
--- a/drivers/video/fbdev/cyber2000fb.c
+++ b/drivers/video/fbdev/cyber2000fb.c
@@ -1060,7 +1060,7 @@ static int cyber2000fb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops cyber2000fb_ops = {
+static const struct fb_ops cyber2000fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= cyber2000fb_check_var,
 	.fb_set_par	= cyber2000fb_set_par,
diff --git a/drivers/video/fbdev/da8xx-fb.c b/drivers/video/fbdev/da8xx-fb.c
index 2d3dcc52fcf3..73c3c4c8cc12 100644
--- a/drivers/video/fbdev/da8xx-fb.c
+++ b/drivers/video/fbdev/da8xx-fb.c
@@ -1294,7 +1294,7 @@ static int da8xxfb_set_par(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops da8xx_fb_ops = {
+static const struct fb_ops da8xx_fb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = fb_check_var,
 	.fb_set_par = da8xxfb_set_par,
diff --git a/drivers/video/fbdev/dnfb.c b/drivers/video/fbdev/dnfb.c
index 8da517eaa4a3..3688f9165848 100644
--- a/drivers/video/fbdev/dnfb.c
+++ b/drivers/video/fbdev/dnfb.c
@@ -108,7 +108,7 @@
 static int dnfb_blank(int blank, struct fb_info *info);
 static void dnfb_copyarea(struct fb_info *info, const struct fb_copyarea *area);
 
-static struct fb_ops dn_fb_ops = {
+static const struct fb_ops dn_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_blank	= dnfb_blank,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index 51d97ec4f58f..f03f9fb60c26 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -255,7 +255,7 @@ static void efifb_destroy(struct fb_info *info)
 	fb_dealloc_cmap(&info->cmap);
 }
 
-static struct fb_ops efifb_ops = {
+static const struct fb_ops efifb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_destroy	= efifb_destroy,
 	.fb_setcolreg	= efifb_setcolreg,
diff --git a/drivers/video/fbdev/ep93xx-fb.c b/drivers/video/fbdev/ep93xx-fb.c
index d04a047094fc..cda2ef337423 100644
--- a/drivers/video/fbdev/ep93xx-fb.c
+++ b/drivers/video/fbdev/ep93xx-fb.c
@@ -402,7 +402,7 @@ static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
 	return 0;
 }
 
-static struct fb_ops ep93xxfb_ops = {
+static const struct fb_ops ep93xxfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= ep93xxfb_check_var,
 	.fb_set_par	= ep93xxfb_set_par,
diff --git a/drivers/video/fbdev/fb-puv3.c b/drivers/video/fbdev/fb-puv3.c
index fa62c4dff7d1..75df6aabac21 100644
--- a/drivers/video/fbdev/fb-puv3.c
+++ b/drivers/video/fbdev/fb-puv3.c
@@ -644,7 +644,7 @@ int unifb_mmap(struct fb_info *info,
 	return vm_iomap_memory(vma, info->fix.smem_start, info->fix.smem_len);
 }
 
-static struct fb_ops unifb_ops = {
+static const struct fb_ops unifb_ops = {
 	.fb_read        = fb_sys_read,
 	.fb_write       = fb_sys_write,
 	.fb_check_var	= unifb_check_var,
diff --git a/drivers/video/fbdev/ffb.c b/drivers/video/fbdev/ffb.c
index cd2d1db239a2..948b73184433 100644
--- a/drivers/video/fbdev/ffb.c
+++ b/drivers/video/fbdev/ffb.c
@@ -44,7 +44,7 @@ static int ffb_pan_display(struct fb_var_screeninfo *, struct fb_info *);
  *  Frame buffer operations
  */
 
-static struct fb_ops ffb_ops = {
+static const struct fb_ops ffb_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= ffb_setcolreg,
 	.fb_blank		= ffb_blank,
diff --git a/drivers/video/fbdev/fm2fb.c b/drivers/video/fbdev/fm2fb.c
index ac7a4ebfd390..3b727d528fde 100644
--- a/drivers/video/fbdev/fm2fb.c
+++ b/drivers/video/fbdev/fm2fb.c
@@ -165,7 +165,7 @@ static int fm2fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                            u_int transp, struct fb_info *info);
 static int fm2fb_blank(int blank, struct fb_info *info);
 
-static struct fb_ops fm2fb_ops = {
+static const struct fb_ops fm2fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= fm2fb_setcolreg,
 	.fb_blank	= fm2fb_blank,
diff --git a/drivers/video/fbdev/fsl-diu-fb.c b/drivers/video/fbdev/fsl-diu-fb.c
index d19f58263b4e..7cacabdd5f12 100644
--- a/drivers/video/fbdev/fsl-diu-fb.c
+++ b/drivers/video/fbdev/fsl-diu-fb.c
@@ -1448,7 +1448,7 @@ static int fsl_diu_release(struct fb_info *info, int user)
 	return res;
 }
 
-static struct fb_ops fsl_diu_ops = {
+static const struct fb_ops fsl_diu_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = fsl_diu_check_var,
 	.fb_set_par = fsl_diu_set_par,
diff --git a/drivers/video/fbdev/g364fb.c b/drivers/video/fbdev/g364fb.c
index 223896cc5f7d..845b79da2a7c 100644
--- a/drivers/video/fbdev/g364fb.c
+++ b/drivers/video/fbdev/g364fb.c
@@ -111,7 +111,7 @@ static int g364fb_setcolreg(u_int regno, u_int red, u_int green,
 static int g364fb_cursor(struct fb_info *info, struct fb_cursor *cursor);
 static int g364fb_blank(int blank, struct fb_info *info);
 
-static struct fb_ops g364fb_ops = {
+static const struct fb_ops g364fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= g364fb_setcolreg,
 	.fb_pan_display	= g364fb_pan_display,
diff --git a/drivers/video/fbdev/gbefb.c b/drivers/video/fbdev/gbefb.c
index b9f6a82a0495..31270a8986e8 100644
--- a/drivers/video/fbdev/gbefb.c
+++ b/drivers/video/fbdev/gbefb.c
@@ -1044,7 +1044,7 @@ static int gbefb_mmap(struct fb_info *info,
 	return 0;
 }
 
-static struct fb_ops gbefb_ops = {
+static const struct fb_ops gbefb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= gbefb_check_var,
 	.fb_set_par	= gbefb_set_par,
diff --git a/drivers/video/fbdev/geode/gx1fb_core.c b/drivers/video/fbdev/geode/gx1fb_core.c
index 737e472fac14..5d34d89fb665 100644
--- a/drivers/video/fbdev/geode/gx1fb_core.c
+++ b/drivers/video/fbdev/geode/gx1fb_core.c
@@ -252,7 +252,7 @@ static int parse_panel_option(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops gx1fb_ops = {
+static const struct fb_ops gx1fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= gx1fb_check_var,
 	.fb_set_par	= gx1fb_set_par,
diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
index 435ce2aa4240..d38a148d4746 100644
--- a/drivers/video/fbdev/geode/gxfb_core.c
+++ b/drivers/video/fbdev/geode/gxfb_core.c
@@ -265,7 +265,7 @@ static int gxfb_map_video_memory(struct fb_info *info, struct pci_dev *dev)
 	return 0;
 }
 
-static struct fb_ops gxfb_ops = {
+static const struct fb_ops gxfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= gxfb_check_var,
 	.fb_set_par	= gxfb_set_par,
diff --git a/drivers/video/fbdev/geode/lxfb_core.c b/drivers/video/fbdev/geode/lxfb_core.c
index b0f07d676eb3..adc2d9c2395e 100644
--- a/drivers/video/fbdev/geode/lxfb_core.c
+++ b/drivers/video/fbdev/geode/lxfb_core.c
@@ -386,7 +386,7 @@ static int lxfb_map_video_memory(struct fb_info *info, struct pci_dev *dev)
 	return 0;
 }
 
-static struct fb_ops lxfb_ops = {
+static const struct fb_ops lxfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= lxfb_check_var,
 	.fb_set_par	= lxfb_set_par,
diff --git a/drivers/video/fbdev/goldfishfb.c b/drivers/video/fbdev/goldfishfb.c
index f60ac276703d..9c83ec3f8e1f 100644
--- a/drivers/video/fbdev/goldfishfb.c
+++ b/drivers/video/fbdev/goldfishfb.c
@@ -160,7 +160,7 @@ static int goldfish_fb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops goldfish_fb_ops = {
+static const struct fb_ops goldfish_fb_ops = {
 	.owner          = THIS_MODULE,
 	.fb_check_var   = goldfish_fb_check_var,
 	.fb_set_par     = goldfish_fb_set_par,
diff --git a/drivers/video/fbdev/grvga.c b/drivers/video/fbdev/grvga.c
index d22e8b0c906d..07dda03e0957 100644
--- a/drivers/video/fbdev/grvga.c
+++ b/drivers/video/fbdev/grvga.c
@@ -251,7 +251,7 @@ static int grvga_pan_display(struct fb_var_screeninfo *var,
 	return 0;
 }
 
-static struct fb_ops grvga_ops = {
+static const struct fb_ops grvga_ops = {
 	.owner          = THIS_MODULE,
 	.fb_check_var   = grvga_check_var,
 	.fb_set_par	= grvga_set_par,
diff --git a/drivers/video/fbdev/gxt4500.c b/drivers/video/fbdev/gxt4500.c
index c7502fd8f447..13ded3a10708 100644
--- a/drivers/video/fbdev/gxt4500.c
+++ b/drivers/video/fbdev/gxt4500.c
@@ -599,7 +599,7 @@ static const struct fb_fix_screeninfo gxt4500_fix = {
 	.mmio_len = 0x20000,
 };
 
-static struct fb_ops gxt4500_ops = {
+static const struct fb_ops gxt4500_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = gxt4500_check_var,
 	.fb_set_par = gxt4500_set_par,
diff --git a/drivers/video/fbdev/hecubafb.c b/drivers/video/fbdev/hecubafb.c
index 8577195cb533..00d77105161a 100644
--- a/drivers/video/fbdev/hecubafb.c
+++ b/drivers/video/fbdev/hecubafb.c
@@ -197,7 +197,7 @@ static ssize_t hecubafb_write(struct fb_info *info, const char __user *buf,
 	return (err) ? err : count;
 }
 
-static struct fb_ops hecubafb_ops = {
+static const struct fb_ops hecubafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_read        = fb_sys_read,
 	.fb_write	= hecubafb_write,
diff --git a/drivers/video/fbdev/hgafb.c b/drivers/video/fbdev/hgafb.c
index 59e1cae57948..a45fcff1461f 100644
--- a/drivers/video/fbdev/hgafb.c
+++ b/drivers/video/fbdev/hgafb.c
@@ -523,7 +523,7 @@ static void hgafb_imageblit(struct fb_info *info, const struct fb_image *image)
 	}
 }
 
-static struct fb_ops hgafb_ops = {
+static const struct fb_ops hgafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= hgafb_open,
 	.fb_release	= hgafb_release,
diff --git a/drivers/video/fbdev/hitfb.c b/drivers/video/fbdev/hitfb.c
index abe3e54d4506..009e5d2aa100 100644
--- a/drivers/video/fbdev/hitfb.c
+++ b/drivers/video/fbdev/hitfb.c
@@ -311,7 +311,7 @@ static int hitfb_set_par(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops hitfb_ops = {
+static const struct fb_ops hitfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= hitfb_check_var,
 	.fb_set_par		= hitfb_set_par,
diff --git a/drivers/video/fbdev/hpfb.c b/drivers/video/fbdev/hpfb.c
index a79af8f069d1..f02be0db335e 100644
--- a/drivers/video/fbdev/hpfb.c
+++ b/drivers/video/fbdev/hpfb.c
@@ -184,7 +184,7 @@ static int hpfb_sync(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops hpfb_ops = {
+static const struct fb_ops hpfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= hpfb_setcolreg,
 	.fb_blank	= hpfb_blank,
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index 2dcb7c58b31e..fcd546e5c031 100644
--- a/drivers/video/fbdev/hyperv_fb.c
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -623,7 +623,7 @@ static void hvfb_cfb_imageblit(struct fb_info *p,
 		synthvid_update(p);
 }
 
-static struct fb_ops hvfb_ops = {
+static const struct fb_ops hvfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = hvfb_check_var,
 	.fb_set_par = hvfb_set_par,
diff --git a/drivers/video/fbdev/i740fb.c b/drivers/video/fbdev/i740fb.c
index 347cf8babc3e..c65ec7386e87 100644
--- a/drivers/video/fbdev/i740fb.c
+++ b/drivers/video/fbdev/i740fb.c
@@ -981,7 +981,7 @@ static int i740fb_blank(int blank_mode, struct fb_info *info)
 	return (blank_mode = FB_BLANK_NORMAL) ? 1 : 0;
 }
 
-static struct fb_ops i740fb_ops = {
+static const struct fb_ops i740fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= i740fb_open,
 	.fb_release	= i740fb_release,
diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c
index 58b01c7d9056..3ac053b88495 100644
--- a/drivers/video/fbdev/imsttfb.c
+++ b/drivers/video/fbdev/imsttfb.c
@@ -1333,7 +1333,7 @@ static struct pci_driver imsttfb_pci_driver = {
 	.remove =	imsttfb_remove,
 };
 
-static struct fb_ops imsttfb_ops = {
+static const struct fb_ops imsttfb_ops = {
 	.owner 		= THIS_MODULE,
 	.fb_check_var	= imsttfb_check_var,
 	.fb_set_par 	= imsttfb_set_par,
diff --git a/drivers/video/fbdev/imxfb.c b/drivers/video/fbdev/imxfb.c
index b3286d1fa543..08a17eb2a5c7 100644
--- a/drivers/video/fbdev/imxfb.c
+++ b/drivers/video/fbdev/imxfb.c
@@ -566,7 +566,7 @@ static int imxfb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops imxfb_ops = {
+static const struct fb_ops imxfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= imxfb_check_var,
 	.fb_set_par	= imxfb_set_par,
diff --git a/drivers/video/fbdev/intelfb/intelfbdrv.c b/drivers/video/fbdev/intelfb/intelfbdrv.c
index a76c61512c60..c744891781a5 100644
--- a/drivers/video/fbdev/intelfb/intelfbdrv.c
+++ b/drivers/video/fbdev/intelfb/intelfbdrv.c
@@ -193,7 +193,7 @@ static const struct pci_device_id intelfb_pci_table[] = {
 static int num_registered = 0;
 
 /* fb ops */
-static struct fb_ops intel_fb_ops = {
+static const struct fb_ops intel_fb_ops = {
 	.owner =		THIS_MODULE,
 	.fb_open =              intelfb_open,
 	.fb_release =           intelfb_release,
diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c
index a7bd9f25911b..72dff2e42e3a 100644
--- a/drivers/video/fbdev/kyro/fbdev.c
+++ b/drivers/video/fbdev/kyro/fbdev.c
@@ -648,7 +648,7 @@ static struct pci_driver kyrofb_pci_driver = {
 	.remove		= kyrofb_remove,
 };
 
-static struct fb_ops kyrofb_ops = {
+static const struct fb_ops kyrofb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= kyrofb_check_var,
 	.fb_set_par	= kyrofb_set_par,
diff --git a/drivers/video/fbdev/leo.c b/drivers/video/fbdev/leo.c
index 5b1141ac182b..40b11cce0ad6 100644
--- a/drivers/video/fbdev/leo.c
+++ b/drivers/video/fbdev/leo.c
@@ -39,7 +39,7 @@ static int leo_pan_display(struct fb_var_screeninfo *, struct fb_info *);
  *  Frame buffer operations
  */
 
-static struct fb_ops leo_ops = {
+static const struct fb_ops leo_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= leo_setcolreg,
 	.fb_blank		= leo_blank,
diff --git a/drivers/video/fbdev/macfb.c b/drivers/video/fbdev/macfb.c
index 9a6feee96133..e05a97662ca8 100644
--- a/drivers/video/fbdev/macfb.c
+++ b/drivers/video/fbdev/macfb.c
@@ -496,7 +496,7 @@ static int macfb_setcolreg(unsigned regno, unsigned red, unsigned green,
 	return 0;
 }
 
-static struct fb_ops macfb_ops = {
+static const struct fb_ops macfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= macfb_setcolreg,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/matrox/matroxfb_crtc2.c b/drivers/video/fbdev/matrox/matroxfb_crtc2.c
index d2a81a2c3ac0..7655afa3fd50 100644
--- a/drivers/video/fbdev/matrox/matroxfb_crtc2.c
+++ b/drivers/video/fbdev/matrox/matroxfb_crtc2.c
@@ -563,7 +563,7 @@ static int matroxfb_dh_blank(int blank, struct fb_info* info) {
 #undef m2info
 }
 
-static struct fb_ops matroxfb_dh_ops = {
+static const struct fb_ops matroxfb_dh_ops = {
 	.owner =	THIS_MODULE,
 	.fb_open =	matroxfb_dh_open,
 	.fb_release =	matroxfb_dh_release,
diff --git a/drivers/video/fbdev/maxinefb.c b/drivers/video/fbdev/maxinefb.c
index 5bb1b5c308a7..ae1a42bcb0ea 100644
--- a/drivers/video/fbdev/maxinefb.c
+++ b/drivers/video/fbdev/maxinefb.c
@@ -105,7 +105,7 @@ static int maxinefb_setcolreg(unsigned regno, unsigned red, unsigned green,
 	return 0;
 }
 
-static struct fb_ops maxinefb_ops = {
+static const struct fb_ops maxinefb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= maxinefb_setcolreg,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/mb862xx/mb862xxfbdrv.c b/drivers/video/fbdev/mb862xx/mb862xxfbdrv.c
index 962c0171d271..298e10fe0408 100644
--- a/drivers/video/fbdev/mb862xx/mb862xxfbdrv.c
+++ b/drivers/video/fbdev/mb862xx/mb862xxfbdrv.c
@@ -401,7 +401,7 @@ static int mb862xxfb_ioctl(struct fb_info *fbi, unsigned int cmd,
 }
 
 /* framebuffer ops */
-static struct fb_ops mb862xxfb_ops = {
+static const struct fb_ops mb862xxfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= mb862xxfb_check_var,
 	.fb_set_par	= mb862xxfb_set_par,
diff --git a/drivers/video/fbdev/mbx/mbxfb.c b/drivers/video/fbdev/mbx/mbxfb.c
index 50935252b50b..25dad4507d77 100644
--- a/drivers/video/fbdev/mbx/mbxfb.c
+++ b/drivers/video/fbdev/mbx/mbxfb.c
@@ -671,7 +671,7 @@ static int mbxfb_ioctl(struct fb_info *info, unsigned int cmd,
 	return -EINVAL;
 }
 
-static struct fb_ops mbxfb_ops = {
+static const struct fb_ops mbxfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = mbxfb_check_var,
 	.fb_set_par = mbxfb_set_par,
diff --git a/drivers/video/fbdev/metronomefb.c b/drivers/video/fbdev/metronomefb.c
index bb4fee52e501..a42e2eceee48 100644
--- a/drivers/video/fbdev/metronomefb.c
+++ b/drivers/video/fbdev/metronomefb.c
@@ -558,7 +558,7 @@ static ssize_t metronomefb_write(struct fb_info *info, const char __user *buf,
 	return (err) ? err : count;
 }
 
-static struct fb_ops metronomefb_ops = {
+static const struct fb_ops metronomefb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_write	= metronomefb_write,
 	.fb_fillrect	= metronomefb_fillrect,
diff --git a/drivers/video/fbdev/mmp/fb/mmpfb.c b/drivers/video/fbdev/mmp/fb/mmpfb.c
index 47bc7c59bbd8..33db0850086f 100644
--- a/drivers/video/fbdev/mmp/fb/mmpfb.c
+++ b/drivers/video/fbdev/mmp/fb/mmpfb.c
@@ -454,7 +454,7 @@ static int mmpfb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops mmpfb_ops = {
+static const struct fb_ops mmpfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_blank	= mmpfb_blank,
 	.fb_check_var	= mmpfb_check_var,
diff --git a/drivers/video/fbdev/mx3fb.c b/drivers/video/fbdev/mx3fb.c
index bafd5f5fac5a..9486ada8b20b 100644
--- a/drivers/video/fbdev/mx3fb.c
+++ b/drivers/video/fbdev/mx3fb.c
@@ -1249,7 +1249,7 @@ static int mx3fb_pan_display(struct fb_var_screeninfo *var,
  * invoked by the core framebuffer driver to perform operations like
  * blitting, rectangle filling, copy regions and cursor definition.
  */
-static struct fb_ops mx3fb_ops = {
+const static struct fb_ops mx3fb_ops = {
 	.owner = THIS_MODULE,
 	.fb_set_par = mx3fb_set_par,
 	.fb_check_var = mx3fb_check_var,
@@ -1389,7 +1389,8 @@ static int mx3fb_unmap_video_memory(struct fb_info *fbi)
  * mx3fb_init_fbinfo() - initialize framebuffer information object.
  * @return:	initialized framebuffer structure.
  */
-static struct fb_info *mx3fb_init_fbinfo(struct device *dev, struct fb_ops *ops)
+static struct fb_info *mx3fb_init_fbinfo(struct device *dev,
+					 const struct fb_ops *ops)
 {
 	struct fb_info *fbi;
 	struct mx3fb_info *mx3fbi;
diff --git a/drivers/video/fbdev/neofb.c b/drivers/video/fbdev/neofb.c
index b770946a0920..e6ea853c1723 100644
--- a/drivers/video/fbdev/neofb.c
+++ b/drivers/video/fbdev/neofb.c
@@ -1610,7 +1610,7 @@ neofb_cursor(struct fb_info *info, struct fb_cursor *cursor)
 }
 */
 
-static struct fb_ops neofb_ops = {
+static const struct fb_ops neofb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= neofb_open,
 	.fb_release	= neofb_release,
diff --git a/drivers/video/fbdev/nvidia/nvidia.c b/drivers/video/fbdev/nvidia/nvidia.c
index fbeeed5afe35..8a2527b0fd27 100644
--- a/drivers/video/fbdev/nvidia/nvidia.c
+++ b/drivers/video/fbdev/nvidia/nvidia.c
@@ -1024,7 +1024,7 @@ static int nvidiafb_release(struct fb_info *info, int user)
 	return err;
 }
 
-static struct fb_ops nvidia_fb_ops = {
+static const struct fb_ops nvidia_fb_ops = {
 	.owner          = THIS_MODULE,
 	.fb_open        = nvidiafb_open,
 	.fb_release     = nvidiafb_release,
diff --git a/drivers/video/fbdev/ocfb.c b/drivers/video/fbdev/ocfb.c
index a970edc2a6f8..c8cee2d890dc 100644
--- a/drivers/video/fbdev/ocfb.c
+++ b/drivers/video/fbdev/ocfb.c
@@ -285,7 +285,7 @@ static int ocfb_init_var(struct ocfb_dev *fbdev)
 	return 0;
 }
 
-static struct fb_ops ocfb_ops = {
+static const struct fb_ops ocfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= ocfb_setcolreg,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/offb.c b/drivers/video/fbdev/offb.c
index fbc6eafb63c7..5cd0f5f6a4ae 100644
--- a/drivers/video/fbdev/offb.c
+++ b/drivers/video/fbdev/offb.c
@@ -286,7 +286,7 @@ static void offb_destroy(struct fb_info *info)
 	framebuffer_release(info);
 }
 
-static struct fb_ops offb_ops = {
+static const struct fb_ops offb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_destroy	= offb_destroy,
 	.fb_setcolreg	= offb_setcolreg,
diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-main.c b/drivers/video/fbdev/omap2/omapfb/omapfb-main.c
index 858c2c011d19..8dfa9158ba78 100644
--- a/drivers/video/fbdev/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/fbdev/omap2/omapfb/omapfb-main.c
@@ -1280,7 +1280,7 @@ ssize_t omapfb_write(struct fb_info *info, const char __user *buf,
 }
 #endif
 
-static struct fb_ops omapfb_ops = {
+static const struct fb_ops omapfb_ops = {
 	.owner          = THIS_MODULE,
 	.fb_open        = omapfb_open,
 	.fb_release     = omapfb_release,
diff --git a/drivers/video/fbdev/p9100.c b/drivers/video/fbdev/p9100.c
index 8c18cc51aae2..6da672e92643 100644
--- a/drivers/video/fbdev/p9100.c
+++ b/drivers/video/fbdev/p9100.c
@@ -37,7 +37,7 @@ static int p9100_ioctl(struct fb_info *, unsigned int, unsigned long);
  *  Frame buffer operations
  */
 
-static struct fb_ops p9100_ops = {
+static const struct fb_ops p9100_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= p9100_setcolreg,
 	.fb_blank		= p9100_blank,
diff --git a/drivers/video/fbdev/platinumfb.c b/drivers/video/fbdev/platinumfb.c
index 632b246ca35f..ce413a9df06e 100644
--- a/drivers/video/fbdev/platinumfb.c
+++ b/drivers/video/fbdev/platinumfb.c
@@ -96,7 +96,7 @@ static int platinum_var_to_par(struct fb_var_screeninfo *var,
  * Interface used by the world
  */
 
-static struct fb_ops platinumfb_ops = {
+static const struct fb_ops platinumfb_ops = {
 	.owner =	THIS_MODULE,
 	.fb_check_var	= platinumfb_check_var,
 	.fb_set_par	= platinumfb_set_par,
diff --git a/drivers/video/fbdev/pm2fb.c b/drivers/video/fbdev/pm2fb.c
index 1dcf02e12af4..8f933bad461c 100644
--- a/drivers/video/fbdev/pm2fb.c
+++ b/drivers/video/fbdev/pm2fb.c
@@ -1483,7 +1483,7 @@ static int pm2fb_cursor(struct fb_info *info, struct fb_cursor *cursor)
  *  Frame buffer operations
  */
 
-static struct fb_ops pm2fb_ops = {
+static const struct fb_ops pm2fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= pm2fb_check_var,
 	.fb_set_par	= pm2fb_set_par,
diff --git a/drivers/video/fbdev/pm3fb.c b/drivers/video/fbdev/pm3fb.c
index 6130aa56a1e9..15a2b495235b 100644
--- a/drivers/video/fbdev/pm3fb.c
+++ b/drivers/video/fbdev/pm3fb.c
@@ -1200,7 +1200,7 @@ static int pm3fb_blank(int blank_mode, struct fb_info *info)
 	 *  Frame buffer operations
 	 */
 
-static struct fb_ops pm3fb_ops = {
+static const struct fb_ops pm3fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= pm3fb_check_var,
 	.fb_set_par	= pm3fb_set_par,
diff --git a/drivers/video/fbdev/pmag-aa-fb.c b/drivers/video/fbdev/pmag-aa-fb.c
index d1e78ce3a9c2..7b33b52b2526 100644
--- a/drivers/video/fbdev/pmag-aa-fb.c
+++ b/drivers/video/fbdev/pmag-aa-fb.c
@@ -147,7 +147,7 @@ static int aafb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops aafb_ops = {
+static const struct fb_ops aafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_blank	= aafb_blank,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/pmag-ba-fb.c b/drivers/video/fbdev/pmag-ba-fb.c
index 56b912bb28de..a60e56d8980b 100644
--- a/drivers/video/fbdev/pmag-ba-fb.c
+++ b/drivers/video/fbdev/pmag-ba-fb.c
@@ -117,7 +117,7 @@ static int pmagbafb_setcolreg(unsigned int regno, unsigned int red,
 	return 0;
 }
 
-static struct fb_ops pmagbafb_ops = {
+static const struct fb_ops pmagbafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= pmagbafb_setcolreg,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/pmagb-b-fb.c b/drivers/video/fbdev/pmagb-b-fb.c
index 2822b2225924..f02080f21077 100644
--- a/drivers/video/fbdev/pmagb-b-fb.c
+++ b/drivers/video/fbdev/pmagb-b-fb.c
@@ -121,7 +121,7 @@ static int pmagbbfb_setcolreg(unsigned int regno, unsigned int red,
 	return 0;
 }
 
-static struct fb_ops pmagbbfb_ops = {
+static const struct fb_ops pmagbbfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= pmagbbfb_setcolreg,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/ps3fb.c b/drivers/video/fbdev/ps3fb.c
index 5ed2db39d823..834f63edf700 100644
--- a/drivers/video/fbdev/ps3fb.c
+++ b/drivers/video/fbdev/ps3fb.c
@@ -934,7 +934,7 @@ static irqreturn_t ps3fb_vsync_interrupt(int irq, void *ptr)
 }
 
 
-static struct fb_ops ps3fb_ops = {
+static const struct fb_ops ps3fb_ops = {
 	.fb_open	= ps3fb_open,
 	.fb_release	= ps3fb_release,
 	.fb_read        = fb_sys_read,
diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c
index 0a3b2b7c7891..fcb16eabbb0d 100644
--- a/drivers/video/fbdev/pvr2fb.c
+++ b/drivers/video/fbdev/pvr2fb.c
@@ -707,7 +707,7 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
 }
 #endif /* CONFIG_PVR2_DMA */
 
-static struct fb_ops pvr2fb_ops = {
+static const struct fb_ops pvr2fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= pvr2fb_setcolreg,
 	.fb_blank	= pvr2fb_blank,
diff --git a/drivers/video/fbdev/pxa168fb.c b/drivers/video/fbdev/pxa168fb.c
index 1410f476e135..c672c3354a2c 100644
--- a/drivers/video/fbdev/pxa168fb.c
+++ b/drivers/video/fbdev/pxa168fb.c
@@ -545,7 +545,7 @@ static irqreturn_t pxa168fb_handle_irq(int irq, void *dev_id)
 	return IRQ_NONE;
 }
 
-static struct fb_ops pxa168fb_ops = {
+static const struct fb_ops pxa168fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= pxa168fb_check_var,
 	.fb_set_par	= pxa168fb_set_par,
diff --git a/drivers/video/fbdev/pxafb.c b/drivers/video/fbdev/pxafb.c
index f70c9f79622e..6f7e9fb63190 100644
--- a/drivers/video/fbdev/pxafb.c
+++ b/drivers/video/fbdev/pxafb.c
@@ -597,7 +597,7 @@ static int pxafb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops pxafb_ops = {
+static const struct fb_ops pxafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= pxafb_check_var,
 	.fb_set_par	= pxafb_set_par,
@@ -865,7 +865,7 @@ static int overlayfb_set_par(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops overlay_fb_ops = {
+static const struct fb_ops overlay_fb_ops = {
 	.owner			= THIS_MODULE,
 	.fb_open		= overlayfb_open,
 	.fb_release		= overlayfb_release,
diff --git a/drivers/video/fbdev/q40fb.c b/drivers/video/fbdev/q40fb.c
index 0b93aa964d43..79ff14a35c85 100644
--- a/drivers/video/fbdev/q40fb.c
+++ b/drivers/video/fbdev/q40fb.c
@@ -75,7 +75,7 @@ static int q40fb_setcolreg(unsigned regno, unsigned red, unsigned green,
     return 0;
 }
 
-static struct fb_ops q40fb_ops = {
+static const struct fb_ops q40fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= q40fb_setcolreg,
 	.fb_fillrect	= cfb_fillrect,
diff --git a/drivers/video/fbdev/riva/fbdev.c b/drivers/video/fbdev/riva/fbdev.c
index ca593a3e41d7..764ec3285e62 100644
--- a/drivers/video/fbdev/riva/fbdev.c
+++ b/drivers/video/fbdev/riva/fbdev.c
@@ -1673,7 +1673,7 @@ static int rivafb_sync(struct fb_info *info)
  * ------------------------------------------------------------------------- */
 
 /* kernel interface */
-static struct fb_ops riva_fb_ops = {
+static const struct fb_ops riva_fb_ops = {
 	.owner 		= THIS_MODULE,
 	.fb_open	= rivafb_open,
 	.fb_release	= rivafb_release,
diff --git a/drivers/video/fbdev/s3c-fb.c b/drivers/video/fbdev/s3c-fb.c
index ba04d7a67829..f4871c430f8d 100644
--- a/drivers/video/fbdev/s3c-fb.c
+++ b/drivers/video/fbdev/s3c-fb.c
@@ -1035,7 +1035,7 @@ static int s3c_fb_ioctl(struct fb_info *info, unsigned int cmd,
 	return ret;
 }
 
-static struct fb_ops s3c_fb_ops = {
+static const struct fb_ops s3c_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= s3c_fb_check_var,
 	.fb_set_par	= s3c_fb_set_par,
diff --git a/drivers/video/fbdev/s3c2410fb.c b/drivers/video/fbdev/s3c2410fb.c
index a702da89910b..2fb15a540167 100644
--- a/drivers/video/fbdev/s3c2410fb.c
+++ b/drivers/video/fbdev/s3c2410fb.c
@@ -618,7 +618,7 @@ static int s3c2410fb_debug_store(struct device *dev,
 
 static DEVICE_ATTR(debug, 0664, s3c2410fb_debug_show, s3c2410fb_debug_store);
 
-static struct fb_ops s3c2410fb_ops = {
+static const struct fb_ops s3c2410fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= s3c2410fb_check_var,
 	.fb_set_par	= s3c2410fb_set_par,
diff --git a/drivers/video/fbdev/s3fb.c b/drivers/video/fbdev/s3fb.c
index be16c349c10f..60c424fae988 100644
--- a/drivers/video/fbdev/s3fb.c
+++ b/drivers/video/fbdev/s3fb.c
@@ -1037,7 +1037,7 @@ static int s3fb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
 
 /* Frame buffer operations */
 
-static struct fb_ops s3fb_ops = {
+static const struct fb_ops s3fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= s3fb_open,
 	.fb_release	= s3fb_release,
diff --git a/drivers/video/fbdev/sa1100fb.c b/drivers/video/fbdev/sa1100fb.c
index 81ad3aa1ca06..4680cc3efb81 100644
--- a/drivers/video/fbdev/sa1100fb.c
+++ b/drivers/video/fbdev/sa1100fb.c
@@ -574,7 +574,7 @@ static int sa1100fb_mmap(struct fb_info *info,
 	return vm_iomap_memory(vma, info->fix.mmio_start, info->fix.mmio_len);
 }
 
-static struct fb_ops sa1100fb_ops = {
+static const struct fb_ops sa1100fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= sa1100fb_check_var,
 	.fb_set_par	= sa1100fb_set_par,
diff --git a/drivers/video/fbdev/savage/savagefb_driver.c b/drivers/video/fbdev/savage/savagefb_driver.c
index 512789f5f884..aab312a7d9da 100644
--- a/drivers/video/fbdev/savage/savagefb_driver.c
+++ b/drivers/video/fbdev/savage/savagefb_driver.c
@@ -1637,7 +1637,7 @@ static int savagefb_release(struct fb_info *info, int user)
 	return 0;
 }
 
-static struct fb_ops savagefb_ops = {
+static const struct fb_ops savagefb_ops = {
 	.owner          = THIS_MODULE,
 	.fb_open        = savagefb_open,
 	.fb_release     = savagefb_release,
diff --git a/drivers/video/fbdev/sh7760fb.c b/drivers/video/fbdev/sh7760fb.c
index ab8fe838c776..b8ec8d9bb4c8 100644
--- a/drivers/video/fbdev/sh7760fb.c
+++ b/drivers/video/fbdev/sh7760fb.c
@@ -341,7 +341,7 @@ static int sh7760fb_set_par(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops sh7760fb_ops = {
+static const struct fb_ops sh7760fb_ops = {
 	.owner = THIS_MODULE,
 	.fb_blank = sh7760fb_blank,
 	.fb_check_var = sh7760fb_check_var,
diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c
index c249763dbf0b..25f119efebc0 100644
--- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
+++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
@@ -1490,7 +1490,7 @@ sh_mobile_lcdc_overlay_mmap(struct fb_info *info, struct vm_area_struct *vma)
 				 ovl->dma_handle, ovl->fb_size);
 }
 
-static struct fb_ops sh_mobile_lcdc_overlay_ops = {
+static const struct fb_ops sh_mobile_lcdc_overlay_ops = {
 	.owner          = THIS_MODULE,
 	.fb_read        = fb_sys_read,
 	.fb_write       = fb_sys_write,
@@ -1964,7 +1964,7 @@ sh_mobile_lcdc_mmap(struct fb_info *info, struct vm_area_struct *vma)
 				 ch->dma_handle, ch->fb_size);
 }
 
-static struct fb_ops sh_mobile_lcdc_ops = {
+static const struct fb_ops sh_mobile_lcdc_ops = {
 	.owner          = THIS_MODULE,
 	.fb_setcolreg	= sh_mobile_lcdc_setcolreg,
 	.fb_read        = fb_sys_read,
diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c
index 7dc0105f700d..533a047d07a2 100644
--- a/drivers/video/fbdev/simplefb.c
+++ b/drivers/video/fbdev/simplefb.c
@@ -78,7 +78,7 @@ static void simplefb_destroy(struct fb_info *info)
 		iounmap(info->screen_base);
 }
 
-static struct fb_ops simplefb_ops = {
+static const struct fb_ops simplefb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_destroy	= simplefb_destroy,
 	.fb_setcolreg	= simplefb_setcolreg,
diff --git a/drivers/video/fbdev/sis/sis_main.c b/drivers/video/fbdev/sis/sis_main.c
index b443a8ed4600..ac140962b1bf 100644
--- a/drivers/video/fbdev/sis/sis_main.c
+++ b/drivers/video/fbdev/sis/sis_main.c
@@ -1906,7 +1906,7 @@ sisfb_get_fix(struct fb_fix_screeninfo *fix, int con, struct fb_info *info)
 
 /* ----------------  fb_ops structures ----------------- */
 
-static struct fb_ops sisfb_ops = {
+static const struct fb_ops sisfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= sisfb_open,
 	.fb_release	= sisfb_release,
diff --git a/drivers/video/fbdev/skeletonfb.c b/drivers/video/fbdev/skeletonfb.c
index 812a36cb60c3..bcacfb6934fa 100644
--- a/drivers/video/fbdev/skeletonfb.c
+++ b/drivers/video/fbdev/skeletonfb.c
@@ -634,7 +634,7 @@ int xxxfb_sync(struct fb_info *info)
      *  Frame buffer operations
      */
 
-static struct fb_ops xxxfb_ops = {
+static const struct fb_ops xxxfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= xxxfb_open,
 	.fb_read	= xxxfb_read,
diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c
index 207d0add684b..6a1b4a853d9e 100644
--- a/drivers/video/fbdev/sm712fb.c
+++ b/drivers/video/fbdev/sm712fb.c
@@ -1369,7 +1369,7 @@ static int smtc_set_par(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops smtcfb_ops = {
+static const struct fb_ops smtcfb_ops = {
 	.owner        = THIS_MODULE,
 	.fb_check_var = smtc_check_var,
 	.fb_set_par   = smtc_set_par,
diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index 78ca7ffc40c2..142535267fec 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -280,7 +280,7 @@ static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *ima
 	ssd1307fb_update_display(par);
 }
 
-static struct fb_ops ssd1307fb_ops = {
+static const struct fb_ops ssd1307fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_read	= fb_sys_read,
 	.fb_write	= ssd1307fb_write,
diff --git a/drivers/video/fbdev/sstfb.c b/drivers/video/fbdev/sstfb.c
index 4e22ae383c87..82e707a48e4e 100644
--- a/drivers/video/fbdev/sstfb.c
+++ b/drivers/video/fbdev/sstfb.c
@@ -1307,7 +1307,7 @@ static int sstfb_setup(char *options)
 }
 
 
-static struct fb_ops sstfb_ops = {
+static const struct fb_ops sstfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= sstfb_check_var,
 	.fb_set_par	= sstfb_set_par,
diff --git a/drivers/video/fbdev/stifb.c b/drivers/video/fbdev/stifb.c
index 9e88e3f594c2..5400ab79fbbd 100644
--- a/drivers/video/fbdev/stifb.c
+++ b/drivers/video/fbdev/stifb.c
@@ -1101,7 +1101,7 @@ stifb_init_display(struct stifb_info *fb)
 
 /* ------------ Interfaces to hardware functions ------------ */
 
-static struct fb_ops stifb_ops = {
+static const struct fb_ops stifb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= stifb_setcolreg,
 	.fb_blank	= stifb_blank,
diff --git a/drivers/video/fbdev/sunxvr1000.c b/drivers/video/fbdev/sunxvr1000.c
index 784c9bd5d502..15b079505a00 100644
--- a/drivers/video/fbdev/sunxvr1000.c
+++ b/drivers/video/fbdev/sunxvr1000.c
@@ -59,7 +59,7 @@ static int gfb_setcolreg(unsigned regno,
 	return 0;
 }
 
-static struct fb_ops gfb_ops = {
+static const struct fb_ops gfb_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= gfb_setcolreg,
 	.fb_fillrect		= cfb_fillrect,
diff --git a/drivers/video/fbdev/sunxvr2500.c b/drivers/video/fbdev/sunxvr2500.c
index 31683e5a8b79..1d3bacd9d5ac 100644
--- a/drivers/video/fbdev/sunxvr2500.c
+++ b/drivers/video/fbdev/sunxvr2500.c
@@ -63,7 +63,7 @@ static int s3d_setcolreg(unsigned regno,
 	return 0;
 }
 
-static struct fb_ops s3d_ops = {
+static const struct fb_ops s3d_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= s3d_setcolreg,
 	.fb_fillrect		= cfb_fillrect,
diff --git a/drivers/video/fbdev/sunxvr500.c b/drivers/video/fbdev/sunxvr500.c
index d392976126a6..9daf17b11106 100644
--- a/drivers/video/fbdev/sunxvr500.c
+++ b/drivers/video/fbdev/sunxvr500.c
@@ -186,7 +186,7 @@ static void e3d_copyarea(struct fb_info *info, const struct fb_copyarea *area)
 	spin_unlock_irqrestore(&ep->lock, flags);
 }
 
-static struct fb_ops e3d_ops = {
+static const struct fb_ops e3d_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= e3d_setcolreg,
 	.fb_fillrect		= e3d_fillrect,
diff --git a/drivers/video/fbdev/tcx.c b/drivers/video/fbdev/tcx.c
index 7897f86fb23e..34b2e5b6e84a 100644
--- a/drivers/video/fbdev/tcx.c
+++ b/drivers/video/fbdev/tcx.c
@@ -40,7 +40,7 @@ static int tcx_pan_display(struct fb_var_screeninfo *, struct fb_info *);
  *  Frame buffer operations
  */
 
-static struct fb_ops tcx_ops = {
+static const struct fb_ops tcx_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= tcx_setcolreg,
 	.fb_blank		= tcx_blank,
diff --git a/drivers/video/fbdev/tdfxfb.c b/drivers/video/fbdev/tdfxfb.c
index fdbb1ea66e6c..0349cf69652f 100644
--- a/drivers/video/fbdev/tdfxfb.c
+++ b/drivers/video/fbdev/tdfxfb.c
@@ -1141,7 +1141,7 @@ static int tdfxfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
 	return 0;
 }
 
-static struct fb_ops tdfxfb_ops = {
+static const struct fb_ops tdfxfb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= tdfxfb_check_var,
 	.fb_set_par	= tdfxfb_set_par,
diff --git a/drivers/video/fbdev/tgafb.c b/drivers/video/fbdev/tgafb.c
index 286b2371c7dd..7cd262858241 100644
--- a/drivers/video/fbdev/tgafb.c
+++ b/drivers/video/fbdev/tgafb.c
@@ -70,7 +70,7 @@ static struct tc_driver tgafb_tc_driver;
  *  Frame buffer operations
  */
 
-static struct fb_ops tgafb_ops = {
+static const struct fb_ops tgafb_ops = {
 	.owner			= THIS_MODULE,
 	.fb_check_var		= tgafb_check_var,
 	.fb_set_par		= tgafb_set_par,
diff --git a/drivers/video/fbdev/tmiofb.c b/drivers/video/fbdev/tmiofb.c
index 4f2fcea10d2b..50111966c981 100644
--- a/drivers/video/fbdev/tmiofb.c
+++ b/drivers/video/fbdev/tmiofb.c
@@ -646,7 +646,7 @@ static int tmiofb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops tmiofb_ops = {
+static const struct fb_ops tmiofb_ops = {
 	.owner		= THIS_MODULE,
 
 	.fb_ioctl	= tmiofb_ioctl,
diff --git a/drivers/video/fbdev/tridentfb.c b/drivers/video/fbdev/tridentfb.c
index da74bf6c5996..715509917eaa 100644
--- a/drivers/video/fbdev/tridentfb.c
+++ b/drivers/video/fbdev/tridentfb.c
@@ -1443,7 +1443,7 @@ static int tridentfb_blank(int blank_mode, struct fb_info *info)
 	return (blank_mode = FB_BLANK_NORMAL) ? 1 : 0;
 }
 
-static struct fb_ops tridentfb_ops = {
+static const struct fb_ops tridentfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_setcolreg = tridentfb_setcolreg,
 	.fb_pan_display = tridentfb_pan_display,
diff --git a/drivers/video/fbdev/uvesafb.c b/drivers/video/fbdev/uvesafb.c
index 439565cae7ab..fb30e6c28afb 100644
--- a/drivers/video/fbdev/uvesafb.c
+++ b/drivers/video/fbdev/uvesafb.c
@@ -1410,7 +1410,7 @@ static int uvesafb_check_var(struct fb_var_screeninfo *var,
 	return 0;
 }
 
-static struct fb_ops uvesafb_ops = {
+static const struct fb_ops uvesafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= uvesafb_open,
 	.fb_release	= uvesafb_release,
diff --git a/drivers/video/fbdev/valkyriefb.c b/drivers/video/fbdev/valkyriefb.c
index e04fde9c1fcd..ca8d7343aaa1 100644
--- a/drivers/video/fbdev/valkyriefb.c
+++ b/drivers/video/fbdev/valkyriefb.c
@@ -113,7 +113,7 @@ static int valkyrie_init_info(struct fb_info *info, struct fb_info_valkyrie *p);
 static void valkyrie_par_to_fix(struct fb_par_valkyrie *par, struct fb_fix_screeninfo *fix);
 static void valkyrie_init_fix(struct fb_fix_screeninfo *fix, struct fb_info_valkyrie *p);
 
-static struct fb_ops valkyriefb_ops = {
+static const struct fb_ops valkyriefb_ops = {
 	.owner =	THIS_MODULE,
 	.fb_check_var =	valkyriefb_check_var,
 	.fb_set_par =	valkyriefb_set_par,
diff --git a/drivers/video/fbdev/vfb.c b/drivers/video/fbdev/vfb.c
index 54127905bfe7..95d3c59867d0 100644
--- a/drivers/video/fbdev/vfb.c
+++ b/drivers/video/fbdev/vfb.c
@@ -78,7 +78,7 @@ static int vfb_pan_display(struct fb_var_screeninfo *var,
 static int vfb_mmap(struct fb_info *info,
 		    struct vm_area_struct *vma);
 
-static struct fb_ops vfb_ops = {
+static const struct fb_ops vfb_ops = {
 	.fb_read        = fb_sys_read,
 	.fb_write       = fb_sys_write,
 	.fb_check_var	= vfb_check_var,
diff --git a/drivers/video/fbdev/vga16fb.c b/drivers/video/fbdev/vga16fb.c
index 2c6a576ed84c..a20eeb8308ff 100644
--- a/drivers/video/fbdev/vga16fb.c
+++ b/drivers/video/fbdev/vga16fb.c
@@ -1270,7 +1270,7 @@ static void vga16fb_destroy(struct fb_info *info)
 	framebuffer_release(info);
 }
 
-static struct fb_ops vga16fb_ops = {
+static const struct fb_ops vga16fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open        = vga16fb_open,
 	.fb_release     = vga16fb_release,
diff --git a/drivers/video/fbdev/vt8500lcdfb.c b/drivers/video/fbdev/vt8500lcdfb.c
index be8d9702cbb2..f744479dc7df 100644
--- a/drivers/video/fbdev/vt8500lcdfb.c
+++ b/drivers/video/fbdev/vt8500lcdfb.c
@@ -238,7 +238,7 @@ static int vt8500lcd_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops vt8500lcd_ops = {
+static const struct fb_ops vt8500lcd_ops = {
 	.owner		= THIS_MODULE,
 	.fb_set_par	= vt8500lcd_set_par,
 	.fb_setcolreg	= vt8500lcd_setcolreg,
diff --git a/drivers/video/fbdev/vt8623fb.c b/drivers/video/fbdev/vt8623fb.c
index c339a8fbad81..7b3eef1b893f 100644
--- a/drivers/video/fbdev/vt8623fb.c
+++ b/drivers/video/fbdev/vt8623fb.c
@@ -634,7 +634,7 @@ static int vt8623fb_pan_display(struct fb_var_screeninfo *var, struct fb_info *i
 
 /* Frame buffer operations */
 
-static struct fb_ops vt8623fb_ops = {
+static const struct fb_ops vt8623fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_open	= vt8623fb_open,
 	.fb_release	= vt8623fb_release,
diff --git a/drivers/video/fbdev/w100fb.c b/drivers/video/fbdev/w100fb.c
index 3be07807edcd..fe628ec20149 100644
--- a/drivers/video/fbdev/w100fb.c
+++ b/drivers/video/fbdev/w100fb.c
@@ -549,7 +549,7 @@ static int w100fb_set_par(struct fb_info *info)
 /*
  *  Frame buffer operations
  */
-static struct fb_ops w100fb_ops = {
+static const struct fb_ops w100fb_ops = {
 	.owner        = THIS_MODULE,
 	.fb_check_var = w100fb_check_var,
 	.fb_set_par   = w100fb_set_par,
diff --git a/drivers/video/fbdev/wm8505fb.c b/drivers/video/fbdev/wm8505fb.c
index 17c780315ca5..b656eff58c23 100644
--- a/drivers/video/fbdev/wm8505fb.c
+++ b/drivers/video/fbdev/wm8505fb.c
@@ -246,7 +246,7 @@ static int wm8505fb_blank(int blank, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops wm8505fb_ops = {
+static const struct fb_ops wm8505fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_set_par	= wm8505fb_set_par,
 	.fb_setcolreg	= wm8505fb_setcolreg,
diff --git a/drivers/video/fbdev/xen-fbfront.c b/drivers/video/fbdev/xen-fbfront.c
index a3d6b6db221b..00307b8693bf 100644
--- a/drivers/video/fbdev/xen-fbfront.c
+++ b/drivers/video/fbdev/xen-fbfront.c
@@ -328,7 +328,7 @@ static int xenfb_set_par(struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops xenfb_fb_ops = {
+static const struct fb_ops xenfb_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_read	= fb_sys_read,
 	.fb_write	= xenfb_write,
diff --git a/drivers/video/fbdev/xilinxfb.c b/drivers/video/fbdev/xilinxfb.c
index 8628829b470d..ca4ff658cad0 100644
--- a/drivers/video/fbdev/xilinxfb.c
+++ b/drivers/video/fbdev/xilinxfb.c
@@ -247,7 +247,7 @@ xilinx_fb_blank(int blank_mode, struct fb_info *fbi)
 	return 0; /* success */
 }
 
-static struct fb_ops xilinxfb_ops = {
+static const struct fb_ops xilinxfb_ops = {
 	.owner			= THIS_MODULE,
 	.fb_setcolreg		= xilinx_fb_setcolreg,
 	.fb_blank		= xilinx_fb_blank,
-- 
2.20.1

[PATCH 11/13] HID: picoLCD: constify fb ops

[Jani Nikula]

Now that the fbops member of struct fb_info is const, we can star making
the ops const as well.

Cc: Bruno Prémont <bonbons@linux-vserver.org>
Cc: linux-input@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/hid/hid-picolcd_fb.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/hid/hid-picolcd_fb.c b/drivers/hid/hid-picolcd_fb.c
index e162a668fb7e..a549c42e8c90 100644
--- a/drivers/hid/hid-picolcd_fb.c
+++ b/drivers/hid/hid-picolcd_fb.c
@@ -417,8 +417,7 @@ static int picolcd_set_par(struct fb_info *info)
 	return 0;
 }
 
-/* Note this can't be const because of struct fb_info definition */
-static struct fb_ops picolcdfb_ops = {
+static const struct fb_ops picolcdfb_ops = {
 	.owner        = THIS_MODULE,
 	.fb_destroy   = picolcd_fb_destroy,
 	.fb_read      = fb_sys_read,
-- 
2.20.1

[PATCH 12/13] media: constify fb ops across all drivers

[Jani Nikula]

Now that the fbops member of struct fb_info is const, we can star making
the ops const as well.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: linux-media@vger.kernel.org
Cc: ivtv-devel@ivtvdriver.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/media/pci/ivtv/ivtvfb.c          | 3 +--
 drivers/media/platform/vivid/vivid-osd.c | 1 -
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c
index 95a56cce9b65..f2922b554b09 100644
--- a/drivers/media/pci/ivtv/ivtvfb.c
+++ b/drivers/media/pci/ivtv/ivtvfb.c
@@ -925,7 +925,7 @@ static int ivtvfb_blank(int blank_mode, struct fb_info *info)
 	return 0;
 }
 
-static struct fb_ops ivtvfb_ops = {
+static const struct fb_ops ivtvfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_write       = ivtvfb_write,
 	.fb_check_var   = ivtvfb_check_var,
@@ -1049,7 +1049,6 @@ static int ivtvfb_init_vidmode(struct ivtv *itv)
 
 	oi->ivtvfb_info.node = -1;
 	oi->ivtvfb_info.flags = FBINFO_FLAG_DEFAULT;
-	oi->ivtvfb_info.fbops = &ivtvfb_ops;
 	oi->ivtvfb_info.par = itv;
 	oi->ivtvfb_info.var = oi->ivtvfb_defined;
 	oi->ivtvfb_info.fix = oi->ivtvfb_fix;
diff --git a/drivers/media/platform/vivid/vivid-osd.c b/drivers/media/platform/vivid/vivid-osd.c
index f2e789bdf4a6..2160a4d3c2f2 100644
--- a/drivers/media/platform/vivid/vivid-osd.c
+++ b/drivers/media/platform/vivid/vivid-osd.c
@@ -311,7 +311,6 @@ static int vivid_fb_init_vidmode(struct vivid_dev *dev)
 
 	dev->fb_info.node = -1;
 	dev->fb_info.flags = FBINFO_FLAG_DEFAULT;
-	dev->fb_info.fbops = &vivid_fb_ops;
 	dev->fb_info.par = dev;
 	dev->fb_info.var = dev->fb_defined;
 	dev->fb_info.fix = dev->fb_fix;
-- 
2.20.1

[PATCH 13/13] samples: vfio-mdev: constify fb ops

[Jani Nikula]

Now that the fbops member of struct fb_info is const, we can star making
the ops const as well.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 samples/vfio-mdev/mdpy-fb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
index 2719bb259653..21dbf63d6e41 100644
--- a/samples/vfio-mdev/mdpy-fb.c
+++ b/samples/vfio-mdev/mdpy-fb.c
@@ -86,7 +86,7 @@ static void mdpy_fb_destroy(struct fb_info *info)
 		iounmap(info->screen_base);
 }
 
-static struct fb_ops mdpy_fb_ops = {
+static const struct fb_ops mdpy_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_destroy	= mdpy_fb_destroy,
 	.fb_setcolreg	= mdpy_fb_setcolreg,
-- 
2.20.1

Re: [PATCH 13/13] samples: vfio-mdev: constify fb ops

[Daniel Vetter]

On Wed, Nov 27, 2019 at 06:32:09PM +0200, Jani Nikula wrote:
> Now that the fbops member of struct fb_info is const, we can star making
> the ops const as well.
> 
> Cc: Kirti Wankhede <kwankhede@nvidia.com>
> Cc: kvm@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

You've missed at least drivers/staging/fbtft in your search. I guess you
need to do a full make allyesconfig on x86/arm and arm64 (the latter
because some stupid drivers only compile there, not on arm, don't ask).
Still misses a pile of mips/ppc only stuff and maybe the sparcs and
alphas, but should be good enough.

With that done, on the remaining patches:

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
>  samples/vfio-mdev/mdpy-fb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
> index 2719bb259653..21dbf63d6e41 100644
> --- a/samples/vfio-mdev/mdpy-fb.c
> +++ b/samples/vfio-mdev/mdpy-fb.c
> @@ -86,7 +86,7 @@ static void mdpy_fb_destroy(struct fb_info *info)
>  		iounmap(info->screen_base);
>  }
>  
> -static struct fb_ops mdpy_fb_ops = {
> +static const struct fb_ops mdpy_fb_ops = {
>  	.owner		= THIS_MODULE,
>  	.fb_destroy	= mdpy_fb_destroy,
>  	.fb_setcolreg	= mdpy_fb_setcolreg,
> -- 
> 2.20.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 13/13] samples: vfio-mdev: constify fb ops

[Jani Nikula]

On Wed, 27 Nov 2019, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Wed, Nov 27, 2019 at 06:32:09PM +0200, Jani Nikula wrote:
>> Now that the fbops member of struct fb_info is const, we can star making
>> the ops const as well.
>> 
>> Cc: Kirti Wankhede <kwankhede@nvidia.com>
>> Cc: kvm@vger.kernel.org
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> You've missed at least drivers/staging/fbtft in your search. I guess you
> need to do a full make allyesconfig on x86/arm and arm64 (the latter
> because some stupid drivers only compile there, not on arm, don't ask).
> Still misses a pile of mips/ppc only stuff and maybe the sparcs and
> alphas, but should be good enough.

fbtft dynamically allocates the fbops, for whatever reason. There were
others like that too. Some of the drivers modify the fbops runtime to
choose different hooks for different configurations. Can't change them
all anyway.

Facilitating making the fbops const is one thing (patches 1-8), but I'm
not really sure I want to sign up for exhaustively moving fbops to
rodata on anything beyond drivers/gpu/drm. It's not like I leave stuff
broken. Besides I am trying to cover all the low hanging fruit where I
can simply add the "const" and be done with it.

BR,
Jani.

>
> With that done, on the remaining patches:
>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
>> ---
>>  samples/vfio-mdev/mdpy-fb.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
>> index 2719bb259653..21dbf63d6e41 100644
>> --- a/samples/vfio-mdev/mdpy-fb.c
>> +++ b/samples/vfio-mdev/mdpy-fb.c
>> @@ -86,7 +86,7 @@ static void mdpy_fb_destroy(struct fb_info *info)
>>  		iounmap(info->screen_base);
>>  }
>>  
>> -static struct fb_ops mdpy_fb_ops = {
>> +static const struct fb_ops mdpy_fb_ops = {
>>  	.owner		= THIS_MODULE,
>>  	.fb_destroy	= mdpy_fb_destroy,
>>  	.fb_setcolreg	= mdpy_fb_setcolreg,
>> -- 
>> 2.20.1
>> 
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [PATCH 13/13] samples: vfio-mdev: constify fb ops

[Daniel Vetter]

On Thu, Nov 28, 2019 at 11:22:23AM +0200, Jani Nikula wrote:
> On Wed, 27 Nov 2019, Daniel Vetter <daniel@ffwll.ch> wrote:
> > On Wed, Nov 27, 2019 at 06:32:09PM +0200, Jani Nikula wrote:
> >> Now that the fbops member of struct fb_info is const, we can star making
> >> the ops const as well.
> >> 
> >> Cc: Kirti Wankhede <kwankhede@nvidia.com>
> >> Cc: kvm@vger.kernel.org
> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> >
> > You've missed at least drivers/staging/fbtft in your search. I guess you
> > need to do a full make allyesconfig on x86/arm and arm64 (the latter
> > because some stupid drivers only compile there, not on arm, don't ask).
> > Still misses a pile of mips/ppc only stuff and maybe the sparcs and
> > alphas, but should be good enough.
> 
> fbtft dynamically allocates the fbops, for whatever reason. There were
> others like that too. Some of the drivers modify the fbops runtime to
> choose different hooks for different configurations. Can't change them
> all anyway.
> 
> Facilitating making the fbops const is one thing (patches 1-8), but I'm
> not really sure I want to sign up for exhaustively moving fbops to
> rodata on anything beyond drivers/gpu/drm. It's not like I leave stuff
> broken. Besides I am trying to cover all the low hanging fruit where I
> can simply add the "const" and be done with it.

Uh indeed, I didn't check the output of my grep with sufficient finesses.
r-b as-is on that pile.

Since fbdev is officially in drm-misc you can just merge it all once the
prep is done - feels silly not to when you've done the work already.
-Daniel

> 
> BR,
> Jani.
> 
> >
> > With that done, on the remaining patches:
> >
> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> >
> >> ---
> >>  samples/vfio-mdev/mdpy-fb.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >> 
> >> diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
> >> index 2719bb259653..21dbf63d6e41 100644
> >> --- a/samples/vfio-mdev/mdpy-fb.c
> >> +++ b/samples/vfio-mdev/mdpy-fb.c
> >> @@ -86,7 +86,7 @@ static void mdpy_fb_destroy(struct fb_info *info)
> >>  		iounmap(info->screen_base);
> >>  }
> >>  
> >> -static struct fb_ops mdpy_fb_ops = {
> >> +static const struct fb_ops mdpy_fb_ops = {
> >>  	.owner		= THIS_MODULE,
> >>  	.fb_destroy	= mdpy_fb_destroy,
> >>  	.fb_setcolreg	= mdpy_fb_setcolreg,
> >> -- 
> >> 2.20.1
> >> 
> >> _______________________________________________
> >> dri-devel mailing list
> >> dri-devel@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 13/13] samples: vfio-mdev: constify fb ops

[Christophe de Dinechin]

> On 27 Nov 2019, at 17:32, Jani Nikula <jani.nikula@intel.com> wrote:
> 
> Now that the fbops member of struct fb_info is const, we can star making
s/star/start/

> the ops const as well.
> 
> Cc: Kirti Wankhede <kwankhede@nvidia.com>
> Cc: kvm@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
> samples/vfio-mdev/mdpy-fb.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
> index 2719bb259653..21dbf63d6e41 100644
> --- a/samples/vfio-mdev/mdpy-fb.c
> +++ b/samples/vfio-mdev/mdpy-fb.c
> @@ -86,7 +86,7 @@ static void mdpy_fb_destroy(struct fb_info *info)
> 		iounmap(info->screen_base);
> }
> 
> -static struct fb_ops mdpy_fb_ops = {
> +static const struct fb_ops mdpy_fb_ops = {
> 	.owner		= THIS_MODULE,
> 	.fb_destroy	= mdpy_fb_destroy,
> 	.fb_setcolreg	= mdpy_fb_setcolreg,
> -- 
> 2.20.1
> 

Re: [PATCH 13/13] samples: vfio-mdev: constify fb ops

[Jani Nikula]

On Thu, 28 Nov 2019, Christophe de Dinechin <christophe.de.dinechin@gmail.com> wrote:
>> On 27 Nov 2019, at 17:32, Jani Nikula <jani.nikula@intel.com> wrote:
>> 
>> Now that the fbops member of struct fb_info is const, we can star making
> s/star/start/

Ooops, thanks.

BR,
Jani.

>
>> the ops const as well.
>> 
>> Cc: Kirti Wankhede <kwankhede@nvidia.com>
>> Cc: kvm@vger.kernel.org
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> ---
>> samples/vfio-mdev/mdpy-fb.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
>> index 2719bb259653..21dbf63d6e41 100644
>> --- a/samples/vfio-mdev/mdpy-fb.c
>> +++ b/samples/vfio-mdev/mdpy-fb.c
>> @@ -86,7 +86,7 @@ static void mdpy_fb_destroy(struct fb_info *info)
>> 		iounmap(info->screen_base);
>> }
>> 
>> -static struct fb_ops mdpy_fb_ops = {
>> +static const struct fb_ops mdpy_fb_ops = {
>> 	.owner		= THIS_MODULE,
>> 	.fb_destroy	= mdpy_fb_destroy,
>> 	.fb_setcolreg	= mdpy_fb_setcolreg,
>> -- 
>> 2.20.1
>> 
>

-- 
Jani Nikula, Intel Open Source Graphics Center