Hi

Am 23.03.20 um 15:49 schrieb Daniel Vetter:
> The cleanup here is somewhat tricky, since we can't tell apart the
> allocated minor index from 0. So register a cleanup action first, and
> if the index allocation fails, unregister that cleanup action again to
> avoid bad mistakes.
> 
> The kdev for the minor already handles NULL, so no problem there.
> 
> Hence add drmm_remove_action() to the drm_managed library.
> 
> v2: Make pointer math around void ** consistent with what Laurent
> suggested.
> 
> v3: Use drmm_add_action_or_reset and remove drmm_remove_action. Noticed
> because of some questions from Thomas. This also means we need to move
> the drmm_add_action_or_reset helper earlier in the series.
> 
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

This code looks easier to understand than the previous patch.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>

> ---
>  drivers/gpu/drm/drm_drv.c     | 70 ++++++++++++-----------------------
>  drivers/gpu/drm/drm_managed.c | 14 +++++++
>  include/drm/drm_managed.h     |  9 ++++-
>  3 files changed, 46 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index a710c53d13a8..25fc2107057c 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -93,13 +93,25 @@ static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
>  	}
>  }
>  
> +static void drm_minor_alloc_release(struct drm_device *dev, void *data)
> +{
> +	struct drm_minor *minor = data;
> +	unsigned long flags;
> +
> +	put_device(minor->kdev);
> +
> +	spin_lock_irqsave(&drm_minor_lock, flags);
> +	idr_remove(&drm_minors_idr, minor->index);
> +	spin_unlock_irqrestore(&drm_minor_lock, flags);
> +}
> +
>  static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
>  {
>  	struct drm_minor *minor;
>  	unsigned long flags;
>  	int r;
>  
> -	minor = kzalloc(sizeof(*minor), GFP_KERNEL);
> +	minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
>  	if (!minor)
>  		return -ENOMEM;
>  
> @@ -117,46 +129,19 @@ static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
>  	idr_preload_end();
>  
>  	if (r < 0)
> -		goto err_free;
> +		return r;
>  
> -	minor->index = r;
> +	r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
> +	if (r)
> +		return r;
>  
> +	minor->index = r;
>  	minor->kdev = drm_sysfs_minor_alloc(minor);
> -	if (IS_ERR(minor->kdev)) {
> -		r = PTR_ERR(minor->kdev);
> -		goto err_index;
> -	}
> +	if (IS_ERR(minor->kdev))
> +		return PTR_ERR(minor->kdev);
>  
>  	*drm_minor_get_slot(dev, type) = minor;
>  	return 0;
> -
> -err_index:
> -	spin_lock_irqsave(&drm_minor_lock, flags);
> -	idr_remove(&drm_minors_idr, minor->index);
> -	spin_unlock_irqrestore(&drm_minor_lock, flags);
> -err_free:
> -	kfree(minor);
> -	return r;
> -}
> -
> -static void drm_minor_free(struct drm_device *dev, unsigned int type)
> -{
> -	struct drm_minor **slot, *minor;
> -	unsigned long flags;
> -
> -	slot = drm_minor_get_slot(dev, type);
> -	minor = *slot;
> -	if (!minor)
> -		return;
> -
> -	put_device(minor->kdev);
> -
> -	spin_lock_irqsave(&drm_minor_lock, flags);
> -	idr_remove(&drm_minors_idr, minor->index);
> -	spin_unlock_irqrestore(&drm_minor_lock, flags);
> -
> -	kfree(minor);
> -	*slot = NULL;
>  }
>  
>  static int drm_minor_register(struct drm_device *dev, unsigned int type)
> @@ -678,16 +663,16 @@ int drm_dev_init(struct drm_device *dev,
>  	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
>  		ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
>  		if (ret)
> -			goto err_minors;
> +			goto err;
>  	}
>  
>  	ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
>  	if (ret)
> -		goto err_minors;
> +		goto err;
>  
>  	ret = drm_legacy_create_map_hash(dev);
>  	if (ret)
> -		goto err_minors;
> +		goto err;
>  
>  	drm_legacy_ctxbitmap_init(dev);
>  
> @@ -695,7 +680,7 @@ int drm_dev_init(struct drm_device *dev,
>  		ret = drm_gem_init(dev);
>  		if (ret) {
>  			DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
> -			goto err_ctxbitmap;
> +			goto err;
>  		}
>  	}
>  
> @@ -708,10 +693,6 @@ int drm_dev_init(struct drm_device *dev,
>  err_setunique:
>  	if (drm_core_check_feature(dev, DRIVER_GEM))
>  		drm_gem_destroy(dev);
> -err_ctxbitmap:
> -err_minors:
> -	drm_minor_free(dev, DRM_MINOR_PRIMARY);
> -	drm_minor_free(dev, DRM_MINOR_RENDER);
>  err:
>  	drm_managed_release(dev);
>  
> @@ -776,9 +757,6 @@ void drm_dev_fini(struct drm_device *dev)
>  
>  	if (drm_core_check_feature(dev, DRIVER_GEM))
>  		drm_gem_destroy(dev);
> -
> -	drm_minor_free(dev, DRM_MINOR_PRIMARY);
> -	drm_minor_free(dev, DRM_MINOR_RENDER);
>  }
>  EXPORT_SYMBOL(drm_dev_fini);
>  
> diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c
> index c633c2ef5269..8abf3a53aeb5 100644
> --- a/drivers/gpu/drm/drm_managed.c
> +++ b/drivers/gpu/drm/drm_managed.c
> @@ -149,6 +149,20 @@ int __drmm_add_action(struct drm_device *dev,
>  }
>  EXPORT_SYMBOL(__drmm_add_action);
>  
> +int __drmm_add_action_or_reset(struct drm_device *dev,
> +			       drmres_release_t action,
> +			       void *data, const char *name)
> +{
> +	int ret;
> +
> +	ret = __drmm_add_action(dev, action, data, name);
> +	if (ret)
> +		action(dev, data);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(__drmm_add_action_or_reset);
> +
>  void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp)
>  {
>  	struct drmres *dr;
> diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h
> index 89e6fce9f689..2d1e29a2200c 100644
> --- a/include/drm/drm_managed.h
> +++ b/include/drm/drm_managed.h
> @@ -17,7 +17,14 @@ int __must_check __drmm_add_action(struct drm_device *dev,
>  				   drmres_release_t action,
>  				   void *data, const char *name);
>  
> -void drmm_add_final_kfree(struct drm_device *dev, void *parent);
> +#define drmm_add_action_or_reset(dev, action, data) \
> +	__drmm_add_action_or_reset(dev, action, data, #action)
> +
> +int __must_check __drmm_add_action_or_reset(struct drm_device *dev,
> +					    drmres_release_t action,
> +					    void *data, const char *name);
> +
> +void drmm_add_final_kfree(struct drm_device *dev, void *container);
>  
>  void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp) __malloc;
>  static inline void *drmm_kzalloc(struct drm_device *dev, size_t size, gfp_t gfp)
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer