block: Remove unused blk_pm_*() function definitions

Commit a1ce35fa ("block: remove dead elevator code") removed the last
callers of blk_pm_requeue_request(), blk_pm_add_request() and
blk_pm_put_request(). Hence remove the definitions of these functions.
Removing these functions removes all users of the struct request nr_pending
member. Hence also remove 'nr_pending'. Note: 'nr_pending' is no longer
used since commit 7cedffec ("block: Make blk_get_request() block for
non-PM requests while suspended").

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-pm.h

@@ -21,31 +21,6 @@ static inline void blk_pm_mark_last_busy(struct request *rq)
 	if (rq->q->dev && !(rq->rq_flags & RQF_PM))
 		pm_runtime_mark_last_busy(rq->q->dev);
 }
-
-static inline void blk_pm_requeue_request(struct request *rq)
-{
-	lockdep_assert_held(&rq->q->queue_lock);
-
-	if (rq->q->dev && !(rq->rq_flags & RQF_PM))
-		rq->q->nr_pending--;
-}
-
-static inline void blk_pm_add_request(struct request_queue *q,
-				      struct request *rq)
-{
-	lockdep_assert_held(&q->queue_lock);
-
-	if (q->dev && !(rq->rq_flags & RQF_PM))
-		q->nr_pending++;
-}
-
-static inline void blk_pm_put_request(struct request *rq)
-{
-	lockdep_assert_held(&rq->q->queue_lock);
-
-	if (rq->q->dev && !(rq->rq_flags & RQF_PM))
-		--rq->q->nr_pending;
-}
 #else
 static inline int blk_pm_resume_queue(const bool pm, struct request_queue *q)
 {
@@ -55,19 +30,6 @@ static inline int blk_pm_resume_queue(const bool pm, struct request_queue *q)
 static inline void blk_pm_mark_last_busy(struct request *rq)
 {
 }
-
-static inline void blk_pm_requeue_request(struct request *rq)
-{
-}
-
-static inline void blk_pm_add_request(struct request_queue *q,
-				      struct request *rq)
-{
-}
-
-static inline void blk_pm_put_request(struct request *rq)
-{
-}
 #endif
 
 #endif /* _BLOCK_BLK_PM_H_ */

include/linux/blkdev.h

@@ -462,7 +462,6 @@ struct request_queue {
 #ifdef CONFIG_PM
 	struct device		*dev;
 	enum rpm_status		rpm_status;
-	unsigned int		nr_pending;
 #endif
 
 	/*