Re: [PATCH 1/3] drm: Add DRM-managed mutex_init()

[Daniel Vetter <daniel@ffwll.ch>]

On Mon, May 02, 2022 at 04:25:12PM +0200, Thomas Zimmermann wrote:
> Add drmm_mutex_init(), a helper that provides managed mutex cleanup. The
> mutex will be destroyed with the final reference of the DRM device.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> on this one, ack for
the other two driver patches.
-Daniel

> ---
>  drivers/gpu/drm/drm_managed.c | 27 +++++++++++++++++++++++++++
>  include/drm/drm_managed.h     |  3 +++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c
> index 37d7db6223be6..4cf214de50c40 100644
> --- a/drivers/gpu/drm/drm_managed.c
> +++ b/drivers/gpu/drm/drm_managed.c
> @@ -8,6 +8,7 @@
>  #include <drm/drm_managed.h>
>  
>  #include <linux/list.h>
> +#include <linux/mutex.h>
>  #include <linux/slab.h>
>  #include <linux/spinlock.h>
>  
> @@ -262,3 +263,29 @@ void drmm_kfree(struct drm_device *dev, void *data)
>  	free_dr(dr_match);
>  }
>  EXPORT_SYMBOL(drmm_kfree);
> +
> +static void drmm_mutex_release(struct drm_device *dev, void *res)
> +{
> +	struct mutex *lock = res;
> +
> +	mutex_destroy(lock);
> +}
> +
> +/**
> + * drmm_mutex_init - &drm_device-managed mutex_init()
> + * @dev: DRM device
> + * @lock: lock to be initialized
> + *
> + * Returns:
> + * 0 on success, or a negative errno code otherwise.
> + *
> + * This is a &drm_device-managed version of mutex_init(). The initialized
> + * lock is automatically destroyed on the final drm_dev_put().
> + */
> +int drmm_mutex_init(struct drm_device *dev, struct mutex *lock)
> +{
> +	mutex_init(lock);
> +
> +	return drmm_add_action_or_reset(dev, drmm_mutex_release, lock);
> +}
> +EXPORT_SYMBOL(drmm_mutex_init);
> diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h
> index b45c6fbf53ac4..359883942612e 100644
> --- a/include/drm/drm_managed.h
> +++ b/include/drm/drm_managed.h
> @@ -8,6 +8,7 @@
>  #include <linux/types.h>
>  
>  struct drm_device;
> +struct mutex;
>  
>  typedef void (*drmres_release_t)(struct drm_device *dev, void *res);
>  
> @@ -104,4 +105,6 @@ char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp);
>  
>  void drmm_kfree(struct drm_device *dev, void *data);
>  
> +int drmm_mutex_init(struct drm_device *dev, struct mutex *lock);
> +
>  #endif
> -- 
> 2.36.0
> 

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