block: Move power management code into a new source file

Move the code for runtime power management from blk-core.c into the
new source file blk-pm.c. Move the corresponding declarations from
<linux/blkdev.h> into <linux/blk-pm.h>. For CONFIG_PM=n, leave out
the declarations of the functions that are not used in that mode.
This patch not only reduces the number of #ifdefs in the block layer
core code but also reduces the size of header file <linux/blkdev.h>
and hence should help to reduce the build time of the Linux kernel
if CONFIG_PM is not defined.

Signed-off-by: Bart Van Assche <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Jianchao Wang <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Johannes Thumshirn <[email protected]>
Cc: Alan Stern <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Bart Van Assche 2018-09-26 14:01:03 -07:00 • committed by Jens Axboe
commit bca6b067b0
11 changed files with 264 additions and 239 deletions

43
block/blk-pm.h Normal file
View file

@ -0,0 +1,43 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BLOCK_BLK_PM_H_
#define _BLOCK_BLK_PM_H_
#include <linux/pm_runtime.h>
#ifdef CONFIG_PM
static inline void blk_pm_requeue_request(struct request *rq)
{
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)
{
if (q->dev && !(rq->rq_flags & RQF_PM) && q->nr_pending++ == 0 &&
(q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING))
pm_request_resume(q->dev);
}
static inline void blk_pm_put_request(struct request *rq)
{
if (rq->q->dev && !(rq->rq_flags & RQF_PM) && !--rq->q->nr_pending)
pm_runtime_mark_last_busy(rq->q->dev);
}
#else
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_ */