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

Lucas De Marchi
2022-11-23T15:06:29Z

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

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