[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 at linux.intel.com>
>Acked-by: Jani Nikula <jani.nikula at intel.com>


Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

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
>