[2/5] drm: Compile out legacy chunks from struct drm_device

Commit Message

Daniel Vetter Oct. 23, 2020, 12:28 p.m. UTC

This means some very few #ifdef in code, but it allows us to
enlist the compiler to make sure this stuff isn't used anymore.

More important, only legacy drivers change drm_device (for the
legacy_dev_list shadow attach management), therefore this is
prep to allow modern drivers to have a const driver struct. Which
is nice, because there's a ton of function pointers in there.

Signed-off-by: Daniel Vetter <[e-mail]>
Cc: Maarten Lankhorst <[e-mail]>
Cc: Maxime Ripard <[e-mail]>
Cc: Thomas Zimmermann <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>
---
 drivers/gpu/drm/drm_file.c   |  2 ++
 drivers/gpu/drm/drm_vblank.c | 15 ++++++++++++---
 include/drm/drm_drv.h        |  2 ++
 3 files changed, 16 insertions(+), 3 deletions(-)

Comments

Maxime Ripard Oct. 23, 2020, 3:10 p.m. UTC | #1

On Fri, Oct 23, 2020 at 02:28:08PM +0200, Daniel Vetter wrote:
> This means some very few #ifdef in code, but it allows us to
> enlist the compiler to make sure this stuff isn't used anymore.
> 
> More important, only legacy drivers change drm_device (for the
> legacy_dev_list shadow attach management), therefore this is
> prep to allow modern drivers to have a const driver struct. Which
> is nice, because there's a ton of function pointers in there.
> 
> Signed-off-by: Daniel Vetter <[e-mail]>
> Cc: Maarten Lankhorst <[e-mail]>
> Cc: Maxime Ripard <[e-mail]>
> Cc: Thomas Zimmermann <[e-mail]>
> Cc: David Airlie <[e-mail]>
> Cc: Daniel Vetter <[e-mail]>
> Signed-off-by: Daniel Vetter <[e-mail]>

Acked-by: Maxime Ripard <[e-mail]>

Maxime

Sam Ravnborg Oct. 25, 2020, 10:08 p.m. UTC | #2

On Fri, Oct 23, 2020 at 02:28:08PM +0200, Daniel Vetter wrote:
> This means some very few #ifdef in code, but it allows us to
> enlist the compiler to make sure this stuff isn't used anymore.
> 
> More important, only legacy drivers change drm_device (for the
> legacy_dev_list shadow attach management), therefore this is
> prep to allow modern drivers to have a const driver struct. Which
> is nice, because there's a ton of function pointers in there.
> 
> Signed-off-by: Daniel Vetter <[e-mail]>
> Cc: Maarten Lankhorst <[e-mail]>
> Cc: Maxime Ripard <[e-mail]>
> Cc: Thomas Zimmermann <[e-mail]>
> Cc: David Airlie <[e-mail]>
> Cc: Daniel Vetter <[e-mail]>
> Signed-off-by: Daniel Vetter <[e-mail]>

Some of the conditionals does not help the readability :-(
But they are better than exposing legacy stuff to non-legacy drivers.
And it is a suprising fews that are required.
So legacy seems to be factored out well from the core.

Reviewed-by: Sam Ravnborg <[e-mail]>
> ---
>  drivers/gpu/drm/drm_file.c   |  2 ++
>  drivers/gpu/drm/drm_vblank.c | 15 ++++++++++++---
>  include/drm/drm_drv.h        |  2 ++
>  3 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 0ac4566ae3f4..b50380fa80ce 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -258,9 +258,11 @@ void drm_file_free(struct drm_file *file)
>  		  (long)old_encode_dev(file->minor->kdev->devt),
>  		  atomic_read(&dev->open_count));
>  
> +#ifdef CONFIG_DRM_LEGACY
>  	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
>  	    dev->driver->preclose)
>  		dev->driver->preclose(dev, file);
> +#endif
>  
>  	if (drm_core_check_feature(dev, DRIVER_LEGACY))
>  		drm_legacy_lock_release(dev, file->filp);
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index ba7e741764aa..15e5ea436434 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -210,9 +210,12 @@ static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
>  
>  		if (crtc->funcs->get_vblank_counter)
>  			return crtc->funcs->get_vblank_counter(crtc);
> -	} else if (dev->driver->get_vblank_counter) {
> +	}
> +#ifdef CONFIG_DRM_LEGACY
> +	else if (dev->driver->get_vblank_counter) {
>  		return dev->driver->get_vblank_counter(dev, pipe);
>  	}
> +#endif
>  
>  	return drm_vblank_no_hw_counter(dev, pipe);
>  }
> @@ -430,9 +433,12 @@ static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
>  
>  		if (crtc->funcs->disable_vblank)
>  			crtc->funcs->disable_vblank(crtc);
> -	} else {
> +	}
> +#ifdef CONFIG_DRM_LEGACY
> +	else {
>  		dev->driver->disable_vblank(dev, pipe);
>  	}
> +#endif
>  }
>  
>  /*
> @@ -1097,9 +1103,12 @@ static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
>  
>  		if (crtc->funcs->enable_vblank)
>  			return crtc->funcs->enable_vblank(crtc);
> -	} else if (dev->driver->enable_vblank) {
> +	}
> +#ifdef CONFIG_DRM_LEGACY
> +	else if (dev->driver->enable_vblank) {
>  		return dev->driver->enable_vblank(dev, pipe);
>  	}
> +#endif
>  
>  	return -EINVAL;
>  }
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index c6d17550efc9..7af220226a25 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -498,6 +498,7 @@ struct drm_driver {
>  	 */
>  	const struct file_operations *fops;
>  
> +#ifdef CONFIG_DRM_LEGACY
>  	/* Everything below here is for legacy driver, never use! */
>  	/* private: */
>  
> @@ -512,6 +513,7 @@ struct drm_driver {
>  	int (*enable_vblank)(struct drm_device *dev, unsigned int pipe);
>  	void (*disable_vblank)(struct drm_device *dev, unsigned int pipe);
>  	int dev_priv_size;
> +#endif
>  };
>  
>  void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
> -- 
> 2.28.0
> 
> _______________________________________________
> dri-devel mailing list
> [e-mail]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

Thomas Zimmermann Oct. 26, 2020, 8:37 a.m. UTC | #3

Hi

Am 23.10.20 um 14:28 schrieb Daniel Vetter:
> This means some very few #ifdef in code, but it allows us to
> enlist the compiler to make sure this stuff isn't used anymore.
> 
> More important, only legacy drivers change drm_device (for the
> legacy_dev_list shadow attach management), therefore this is
> prep to allow modern drivers to have a const driver struct. Which
> is nice, because there's a ton of function pointers in there.
> 
> Signed-off-by: Daniel Vetter <[e-mail]>
> Cc: Maarten Lankhorst <[e-mail]>
> Cc: Maxime Ripard <[e-mail]>
> Cc: Thomas Zimmermann <[e-mail]>
> Cc: David Airlie <[e-mail]>
> Cc: Daniel Vetter <[e-mail]>
> Signed-off-by: Daniel Vetter <[e-mail]>

Review-by: Thomas Zimmermann <[e-mail]>

Sort of related: the implementation for KMS and UMS devices is more and
more distinct from each other. Did you ever consider going for separate
legacy helpers instead of mixing-in all these ifdefs?

Best regards
Thomas

> ---
>  drivers/gpu/drm/drm_file.c   |  2 ++
>  drivers/gpu/drm/drm_vblank.c | 15 ++++++++++++---
>  include/drm/drm_drv.h        |  2 ++
>  3 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 0ac4566ae3f4..b50380fa80ce 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -258,9 +258,11 @@ void drm_file_free(struct drm_file *file)
>  		  (long)old_encode_dev(file->minor->kdev->devt),
>  		  atomic_read(&dev->open_count));
>  
> +#ifdef CONFIG_DRM_LEGACY
>  	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
>  	    dev->driver->preclose)
>  		dev->driver->preclose(dev, file);
> +#endif
>  
>  	if (drm_core_check_feature(dev, DRIVER_LEGACY))
>  		drm_legacy_lock_release(dev, file->filp);
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index ba7e741764aa..15e5ea436434 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -210,9 +210,12 @@ static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
>  
>  		if (crtc->funcs->get_vblank_counter)
>  			return crtc->funcs->get_vblank_counter(crtc);
> -	} else if (dev->driver->get_vblank_counter) {
> +	}
> +#ifdef CONFIG_DRM_LEGACY
> +	else if (dev->driver->get_vblank_counter) {
>  		return dev->driver->get_vblank_counter(dev, pipe);
>  	}
> +#endif
>  
>  	return drm_vblank_no_hw_counter(dev, pipe);
>  }
> @@ -430,9 +433,12 @@ static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
>  
>  		if (crtc->funcs->disable_vblank)
>  			crtc->funcs->disable_vblank(crtc);
> -	} else {
> +	}
> +#ifdef CONFIG_DRM_LEGACY
> +	else {
>  		dev->driver->disable_vblank(dev, pipe);
>  	}
> +#endif
>  }
>  
>  /*
> @@ -1097,9 +1103,12 @@ static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
>  
>  		if (crtc->funcs->enable_vblank)
>  			return crtc->funcs->enable_vblank(crtc);
> -	} else if (dev->driver->enable_vblank) {
> +	}
> +#ifdef CONFIG_DRM_LEGACY
> +	else if (dev->driver->enable_vblank) {
>  		return dev->driver->enable_vblank(dev, pipe);
>  	}
> +#endif
>  
>  	return -EINVAL;
>  }
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index c6d17550efc9..7af220226a25 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -498,6 +498,7 @@ struct drm_driver {
>  	 */
>  	const struct file_operations *fops;
>  
> +#ifdef CONFIG_DRM_LEGACY
>  	/* Everything below here is for legacy driver, never use! */
>  	/* private: */
>  
> @@ -512,6 +513,7 @@ struct drm_driver {
>  	int (*enable_vblank)(struct drm_device *dev, unsigned int pipe);
>  	void (*disable_vblank)(struct drm_device *dev, unsigned int pipe);
>  	int dev_priv_size;
> +#endif
>  };
>  
>  void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
>

Daniel Vetter Oct. 26, 2020, 9:17 a.m. UTC | #4

On Mon, Oct 26, 2020 at 9:37 AM Thomas Zimmermann <[e-mail]> wrote:
>
> Hi
>
> Am 23.10.20 um 14:28 schrieb Daniel Vetter:
> > This means some very few #ifdef in code, but it allows us to
> > enlist the compiler to make sure this stuff isn't used anymore.
> >
> > More important, only legacy drivers change drm_device (for the
> > legacy_dev_list shadow attach management), therefore this is
> > prep to allow modern drivers to have a const driver struct. Which
> > is nice, because there's a ton of function pointers in there.
> >
> > Signed-off-by: Daniel Vetter <[e-mail]>
> > Cc: Maarten Lankhorst <[e-mail]>
> > Cc: Maxime Ripard <[e-mail]>
> > Cc: Thomas Zimmermann <[e-mail]>
> > Cc: David Airlie <[e-mail]>
> > Cc: Daniel Vetter <[e-mail]>
> > Signed-off-by: Daniel Vetter <[e-mail]>
>
> Review-by: Thomas Zimmermann <[e-mail]>
>
> Sort of related: the implementation for KMS and UMS devices is more and
> more distinct from each other. Did you ever consider going for separate
> legacy helpers instead of mixing-in all these ifdefs?

I think we could split out drm_pci_legacy.c. Everything else is
already split out into separate files and made optional at the
Makefile level, it's really only in oddball places around the shared
drm_device where there's any #ifdef at all.
-Daniel

>
> Best regards
> Thomas
>
> > ---
> >  drivers/gpu/drm/drm_file.c   |  2 ++
> >  drivers/gpu/drm/drm_vblank.c | 15 ++++++++++++---
> >  include/drm/drm_drv.h        |  2 ++
> >  3 files changed, 16 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> > index 0ac4566ae3f4..b50380fa80ce 100644
> > --- a/drivers/gpu/drm/drm_file.c
> > +++ b/drivers/gpu/drm/drm_file.c
> > @@ -258,9 +258,11 @@ void drm_file_free(struct drm_file *file)
> >                 (long)old_encode_dev(file->minor->kdev->devt),
> >                 atomic_read(&dev->open_count));
> >
> > +#ifdef CONFIG_DRM_LEGACY
> >       if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
> >           dev->driver->preclose)
> >               dev->driver->preclose(dev, file);
> > +#endif
> >
> >       if (drm_core_check_feature(dev, DRIVER_LEGACY))
> >               drm_legacy_lock_release(dev, file->filp);
> > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> > index ba7e741764aa..15e5ea436434 100644
> > --- a/drivers/gpu/drm/drm_vblank.c
> > +++ b/drivers/gpu/drm/drm_vblank.c
> > @@ -210,9 +210,12 @@ static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
> >
> >               if (crtc->funcs->get_vblank_counter)
> >                       return crtc->funcs->get_vblank_counter(crtc);
> > -     } else if (dev->driver->get_vblank_counter) {
> > +     }
> > +#ifdef CONFIG_DRM_LEGACY
> > +     else if (dev->driver->get_vblank_counter) {
> >               return dev->driver->get_vblank_counter(dev, pipe);
> >       }
> > +#endif
> >
> >       return drm_vblank_no_hw_counter(dev, pipe);
> >  }
> > @@ -430,9 +433,12 @@ static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
> >
> >               if (crtc->funcs->disable_vblank)
> >                       crtc->funcs->disable_vblank(crtc);
> > -     } else {
> > +     }
> > +#ifdef CONFIG_DRM_LEGACY
> > +     else {
> >               dev->driver->disable_vblank(dev, pipe);
> >       }
> > +#endif
> >  }
> >
> >  /*
> > @@ -1097,9 +1103,12 @@ static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
> >
> >               if (crtc->funcs->enable_vblank)
> >                       return crtc->funcs->enable_vblank(crtc);
> > -     } else if (dev->driver->enable_vblank) {
> > +     }
> > +#ifdef CONFIG_DRM_LEGACY
> > +     else if (dev->driver->enable_vblank) {
> >               return dev->driver->enable_vblank(dev, pipe);
> >       }
> > +#endif
> >
> >       return -EINVAL;
> >  }
> > diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> > index c6d17550efc9..7af220226a25 100644
> > --- a/include/drm/drm_drv.h
> > +++ b/include/drm/drm_drv.h
> > @@ -498,6 +498,7 @@ struct drm_driver {
> >        */
> >       const struct file_operations *fops;
> >
> > +#ifdef CONFIG_DRM_LEGACY
> >       /* Everything below here is for legacy driver, never use! */
> >       /* private: */
> >
> > @@ -512,6 +513,7 @@ struct drm_driver {
> >       int (*enable_vblank)(struct drm_device *dev, unsigned int pipe);
> >       void (*disable_vblank)(struct drm_device *dev, unsigned int pipe);
> >       int dev_priv_size;
> > +#endif
> >  };
> >
> >  void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Felix Imendörffer

Patch

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 0ac4566ae3f4..b50380fa80ce 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -258,9 +258,11 @@  void drm_file_free(struct drm_file *file)
 		  (long)old_encode_dev(file->minor->kdev->devt),
 		  atomic_read(&dev->open_count));
 
+#ifdef CONFIG_DRM_LEGACY
 	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
 	    dev->driver->preclose)
 		dev->driver->preclose(dev, file);
+#endif
 
 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 		drm_legacy_lock_release(dev, file->filp);
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index ba7e741764aa..15e5ea436434 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -210,9 +210,12 @@  static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
 
 		if (crtc->funcs->get_vblank_counter)
 			return crtc->funcs->get_vblank_counter(crtc);
-	} else if (dev->driver->get_vblank_counter) {
+	}
+#ifdef CONFIG_DRM_LEGACY
+	else if (dev->driver->get_vblank_counter) {
 		return dev->driver->get_vblank_counter(dev, pipe);
 	}
+#endif
 
 	return drm_vblank_no_hw_counter(dev, pipe);
 }
@@ -430,9 +433,12 @@  static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
 
 		if (crtc->funcs->disable_vblank)
 			crtc->funcs->disable_vblank(crtc);
-	} else {
+	}
+#ifdef CONFIG_DRM_LEGACY
+	else {
 		dev->driver->disable_vblank(dev, pipe);
 	}
+#endif
 }
 
 /*
@@ -1097,9 +1103,12 @@  static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
 
 		if (crtc->funcs->enable_vblank)
 			return crtc->funcs->enable_vblank(crtc);
-	} else if (dev->driver->enable_vblank) {
+	}
+#ifdef CONFIG_DRM_LEGACY
+	else if (dev->driver->enable_vblank) {
 		return dev->driver->enable_vblank(dev, pipe);
 	}
+#endif
 
 	return -EINVAL;
 }
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index c6d17550efc9..7af220226a25 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -498,6 +498,7 @@  struct drm_driver {
 	 */
 	const struct file_operations *fops;
 
+#ifdef CONFIG_DRM_LEGACY
 	/* Everything below here is for legacy driver, never use! */
 	/* private: */
 
@@ -512,6 +513,7 @@  struct drm_driver {
 	int (*enable_vblank)(struct drm_device *dev, unsigned int pipe);
 	void (*disable_vblank)(struct drm_device *dev, unsigned int pipe);
 	int dev_priv_size;
+#endif
 };
 
 void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,