Re: [PATCH v4 1/4] i915: Move list_count() to list.h for broader use

[Lucas De Marchi]

On Wed, Nov 23, 2022 at 04:48:58PM +0200, Andy Shevchenko wrote:
> Some of the existing users, and definitely will be new ones, want to
> count existing nodes in the list. Provide a generic API for that by
> moving code from i915 to list.h.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx>


Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>

thanks
Lucas De Marchi

> ---
> v4: fixed prototype when converting to static inline
> v3: added tag (Jani), changed to be static inline (Mike)
> v2: dropped the duplicate code in i915 (LKP)
> drivers/gpu/drm/i915/gt/intel_engine_cs.c | 13 +------------
> include/linux/list.h                      | 15 +++++++++++++++
> 2 files changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> index c33e0d72d670..b96c8217743c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> @@ -2094,17 +2094,6 @@ static void print_request_ring(struct drm_printer *m, struct i915_request *rq)
> 	}
> }
>
> -static unsigned long list_count(struct list_head *list)
> -{
> -	struct list_head *pos;
> -	unsigned long count = 0;
> -
> -	list_for_each(pos, list)
> -		count++;
> -
> -	return count;
> -}
> -
> static unsigned long read_ul(void *p, size_t x)
> {
> 	return *(unsigned long *)(p + x);
> @@ -2279,7 +2268,7 @@ void intel_engine_dump(struct intel_engine_cs *engine,
> 	spin_lock_irqsave(&engine->sched_engine->lock, flags);
> 	engine_dump_active_requests(engine, m);
>
> -	drm_printf(m, "\tOn hold?: %lu\n",
> +	drm_printf(m, "\tOn hold?: %zu\n",
> 		   list_count(&engine->sched_engine->hold));
> 	spin_unlock_irqrestore(&engine->sched_engine->lock, flags);
>
> diff --git a/include/linux/list.h b/include/linux/list.h
> index 61762054b4be..632a298c7018 100644
> --- a/include/linux/list.h
> +++ b/include/linux/list.h
> @@ -655,6 +655,21 @@ static inline void list_splice_tail_init(struct list_head *list,
> 	     !list_is_head(pos, (head)); \
> 	     pos = n, n = pos->prev)
>
> +/**
> + * list_count - count nodes in the list
> + * @head:	the head for your list.
> + */
> +static inline size_t list_count(struct list_head *head)
> +{
> +	struct list_head *pos;
> +	size_t count = 0;
> +
> +	list_for_each(pos, head)
> +		count++;
> +
> +	return count;
> +}
> +
> /**
>  * list_entry_is_head - test if the entry points to the head of the list
>  * @pos:	the type * to cursor
> --
> 2.35.1