[PATCH v2 1/4] i915: Move list_count() to list.h for broader use

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

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>
---
v2: dropped the duplicate code in i915 (LKP)
 drivers/gpu/drm/i915/gt/intel_engine_cs.c | 13 +------------
 include/linux/list.h                      | 13 +++++++++++++
 2 files changed, 14 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 6ae8b07cfaa1..b5d474be564d 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -2085,17 +2085,6 @@ 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);
@@ -2270,7 +2259,7 @@ 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..098eccf8c1b6 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -655,6 +655,19 @@ 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.
+ */
+#define list_count(head)		\
+({					\
+	struct list_head *__tmp;	\
+	size_t __i = 0;			\
+	list_for_each(__tmp, head)	\
+		__i++;			\
+	__i;				\
+})
+
 /**
  * list_entry_is_head - test if the entry points to the head of the list
  * @pos:	the type * to cursor
-- 
2.35.1