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Commit bca6b067 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe
Browse files

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: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3cfa210b

block/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -228,4 +228,7 @@ config BLK_MQ_RDMA 
	depends on BLOCK && INFINIBAND

	default y



config BLK_PM

	def_bool BLOCK && PM



source block/Kconfig.iosched

block/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -37,3 +37,4 @@ obj-$(CONFIG_BLK_WBT) += blk-wbt.o 
obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o

obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o

obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o

obj-$(CONFIG_BLK_PM)		+= blk-pm.o

block/blk-core.c

+1 −195
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#include "blk.h"

#include "blk-mq.h"

#include "blk-mq-sched.h"

#include "blk-pm.h"

#include "blk-rq-qos.h"



#ifdef CONFIG_DEBUG_FS
@@ -1726,16 +1727,6 @@ void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part) 
}

EXPORT_SYMBOL_GPL(part_round_stats);



#ifdef CONFIG_PM

static 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_put_request(struct request *rq) {}

#endif



void __blk_put_request(struct request_queue *q, struct request *req)

{

	req_flags_t rq_flags = req->rq_flags;
@@ -3757,191 +3748,6 @@ void blk_finish_plug(struct blk_plug *plug) 
}

EXPORT_SYMBOL(blk_finish_plug);



#ifdef CONFIG_PM

/**

 * blk_pm_runtime_init - Block layer runtime PM initialization routine

 * @q: the queue of the device

 * @dev: the device the queue belongs to

 *

 * Description:

 *    Initialize runtime-PM-related fields for @q and start auto suspend for

 *    @dev. Drivers that want to take advantage of request-based runtime PM

 *    should call this function after @dev has been initialized, and its

 *    request queue @q has been allocated, and runtime PM for it can not happen

 *    yet(either due to disabled/forbidden or its usage_count > 0). In most

 *    cases, driver should call this function before any I/O has taken place.

 *

 *    This function takes care of setting up using auto suspend for the device,

 *    the autosuspend delay is set to -1 to make runtime suspend impossible

 *    until an updated value is either set by user or by driver. Drivers do

 *    not need to touch other autosuspend settings.

 *

 *    The block layer runtime PM is request based, so only works for drivers

 *    that use request as their IO unit instead of those directly use bio's.

 */

void blk_pm_runtime_init(struct request_queue *q, struct device *dev)

{

	/* Don't enable runtime PM for blk-mq until it is ready */

	if (q->mq_ops) {

		pm_runtime_disable(dev);

		return;

	}



	q->dev = dev;

	q->rpm_status = RPM_ACTIVE;

	pm_runtime_set_autosuspend_delay(q->dev, -1);

	pm_runtime_use_autosuspend(q->dev);

}

EXPORT_SYMBOL(blk_pm_runtime_init);



/**

 * blk_pre_runtime_suspend - Pre runtime suspend check

 * @q: the queue of the device

 *

 * Description:

 *    This function will check if runtime suspend is allowed for the device

 *    by examining if there are any requests pending in the queue. If there

 *    are requests pending, the device can not be runtime suspended; otherwise,

 *    the queue's status will be updated to SUSPENDING and the driver can

 *    proceed to suspend the device.

 *

 *    For the not allowed case, we mark last busy for the device so that

 *    runtime PM core will try to autosuspend it some time later.

 *

 *    This function should be called near the start of the device's

 *    runtime_suspend callback.

 *

 * Return:

 *    0		- OK to runtime suspend the device

 *    -EBUSY	- Device should not be runtime suspended

 */

int blk_pre_runtime_suspend(struct request_queue *q)

{

	int ret = 0;



	if (!q->dev)

		return ret;



	spin_lock_irq(q->queue_lock);

	if (q->nr_pending) {

		ret = -EBUSY;

		pm_runtime_mark_last_busy(q->dev);

	} else {

		q->rpm_status = RPM_SUSPENDING;

	}

	spin_unlock_irq(q->queue_lock);

	return ret;

}

EXPORT_SYMBOL(blk_pre_runtime_suspend);



/**

 * blk_post_runtime_suspend - Post runtime suspend processing

 * @q: the queue of the device

 * @err: return value of the device's runtime_suspend function

 *

 * Description:

 *    Update the queue's runtime status according to the return value of the

 *    device's runtime suspend function and mark last busy for the device so

 *    that PM core will try to auto suspend the device at a later time.

 *

 *    This function should be called near the end of the device's

 *    runtime_suspend callback.

 */

void blk_post_runtime_suspend(struct request_queue *q, int err)

{

	if (!q->dev)

		return;



	spin_lock_irq(q->queue_lock);

	if (!err) {

		q->rpm_status = RPM_SUSPENDED;

	} else {

		q->rpm_status = RPM_ACTIVE;

		pm_runtime_mark_last_busy(q->dev);

	}

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_post_runtime_suspend);



/**

 * blk_pre_runtime_resume - Pre runtime resume processing

 * @q: the queue of the device

 *

 * Description:

 *    Update the queue's runtime status to RESUMING in preparation for the

 *    runtime resume of the device.

 *

 *    This function should be called near the start of the device's

 *    runtime_resume callback.

 */

void blk_pre_runtime_resume(struct request_queue *q)

{

	if (!q->dev)

		return;



	spin_lock_irq(q->queue_lock);

	q->rpm_status = RPM_RESUMING;

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_pre_runtime_resume);



/**

 * blk_post_runtime_resume - Post runtime resume processing

 * @q: the queue of the device

 * @err: return value of the device's runtime_resume function

 *

 * Description:

 *    Update the queue's runtime status according to the return value of the

 *    device's runtime_resume function. If it is successfully resumed, process

 *    the requests that are queued into the device's queue when it is resuming

 *    and then mark last busy and initiate autosuspend for it.

 *

 *    This function should be called near the end of the device's

 *    runtime_resume callback.

 */

void blk_post_runtime_resume(struct request_queue *q, int err)

{

	if (!q->dev)

		return;



	spin_lock_irq(q->queue_lock);

	if (!err) {

		q->rpm_status = RPM_ACTIVE;

		__blk_run_queue(q);

		pm_runtime_mark_last_busy(q->dev);

		pm_request_autosuspend(q->dev);

	} else {

		q->rpm_status = RPM_SUSPENDED;

	}

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_post_runtime_resume);



/**

 * blk_set_runtime_active - Force runtime status of the queue to be active

 * @q: the queue of the device

 *

 * If the device is left runtime suspended during system suspend the resume

 * hook typically resumes the device and corrects runtime status

 * accordingly. However, that does not affect the queue runtime PM status

 * which is still "suspended". This prevents processing requests from the

 * queue.

 *

 * This function can be used in driver's resume hook to correct queue

 * runtime PM status and re-enable peeking requests from the queue. It

 * should be called before first request is added to the queue.

 */

void blk_set_runtime_active(struct request_queue *q)

{

	spin_lock_irq(q->queue_lock);

	q->rpm_status = RPM_ACTIVE;

	pm_runtime_mark_last_busy(q->dev);

	pm_request_autosuspend(q->dev);

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_set_runtime_active);

#endif



int __init blk_dev_init(void)

{

	BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS));

block/blk-pm.c

0 → 100644
+188 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include <linux/blk-pm.h>

#include <linux/blkdev.h>

#include <linux/pm_runtime.h>



/**

 * blk_pm_runtime_init - Block layer runtime PM initialization routine

 * @q: the queue of the device

 * @dev: the device the queue belongs to

 *

 * Description:

 *    Initialize runtime-PM-related fields for @q and start auto suspend for

 *    @dev. Drivers that want to take advantage of request-based runtime PM

 *    should call this function after @dev has been initialized, and its

 *    request queue @q has been allocated, and runtime PM for it can not happen

 *    yet(either due to disabled/forbidden or its usage_count > 0). In most

 *    cases, driver should call this function before any I/O has taken place.

 *

 *    This function takes care of setting up using auto suspend for the device,

 *    the autosuspend delay is set to -1 to make runtime suspend impossible

 *    until an updated value is either set by user or by driver. Drivers do

 *    not need to touch other autosuspend settings.

 *

 *    The block layer runtime PM is request based, so only works for drivers

 *    that use request as their IO unit instead of those directly use bio's.

 */

void blk_pm_runtime_init(struct request_queue *q, struct device *dev)

{

	/* Don't enable runtime PM for blk-mq until it is ready */

	if (q->mq_ops) {

		pm_runtime_disable(dev);

		return;

	}



	q->dev = dev;

	q->rpm_status = RPM_ACTIVE;

	pm_runtime_set_autosuspend_delay(q->dev, -1);

	pm_runtime_use_autosuspend(q->dev);

}

EXPORT_SYMBOL(blk_pm_runtime_init);



/**

 * blk_pre_runtime_suspend - Pre runtime suspend check

 * @q: the queue of the device

 *

 * Description:

 *    This function will check if runtime suspend is allowed for the device

 *    by examining if there are any requests pending in the queue. If there

 *    are requests pending, the device can not be runtime suspended; otherwise,

 *    the queue's status will be updated to SUSPENDING and the driver can

 *    proceed to suspend the device.

 *

 *    For the not allowed case, we mark last busy for the device so that

 *    runtime PM core will try to autosuspend it some time later.

 *

 *    This function should be called near the start of the device's

 *    runtime_suspend callback.

 *

 * Return:

 *    0		- OK to runtime suspend the device

 *    -EBUSY	- Device should not be runtime suspended

 */

int blk_pre_runtime_suspend(struct request_queue *q)

{

	int ret = 0;



	if (!q->dev)

		return ret;



	spin_lock_irq(q->queue_lock);

	if (q->nr_pending) {

		ret = -EBUSY;

		pm_runtime_mark_last_busy(q->dev);

	} else {

		q->rpm_status = RPM_SUSPENDING;

	}

	spin_unlock_irq(q->queue_lock);

	return ret;

}

EXPORT_SYMBOL(blk_pre_runtime_suspend);



/**

 * blk_post_runtime_suspend - Post runtime suspend processing

 * @q: the queue of the device

 * @err: return value of the device's runtime_suspend function

 *

 * Description:

 *    Update the queue's runtime status according to the return value of the

 *    device's runtime suspend function and mark last busy for the device so

 *    that PM core will try to auto suspend the device at a later time.

 *

 *    This function should be called near the end of the device's

 *    runtime_suspend callback.

 */

void blk_post_runtime_suspend(struct request_queue *q, int err)

{

	if (!q->dev)

		return;



	spin_lock_irq(q->queue_lock);

	if (!err) {

		q->rpm_status = RPM_SUSPENDED;

	} else {

		q->rpm_status = RPM_ACTIVE;

		pm_runtime_mark_last_busy(q->dev);

	}

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_post_runtime_suspend);



/**

 * blk_pre_runtime_resume - Pre runtime resume processing

 * @q: the queue of the device

 *

 * Description:

 *    Update the queue's runtime status to RESUMING in preparation for the

 *    runtime resume of the device.

 *

 *    This function should be called near the start of the device's

 *    runtime_resume callback.

 */

void blk_pre_runtime_resume(struct request_queue *q)

{

	if (!q->dev)

		return;



	spin_lock_irq(q->queue_lock);

	q->rpm_status = RPM_RESUMING;

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_pre_runtime_resume);



/**

 * blk_post_runtime_resume - Post runtime resume processing

 * @q: the queue of the device

 * @err: return value of the device's runtime_resume function

 *

 * Description:

 *    Update the queue's runtime status according to the return value of the

 *    device's runtime_resume function. If it is successfully resumed, process

 *    the requests that are queued into the device's queue when it is resuming

 *    and then mark last busy and initiate autosuspend for it.

 *

 *    This function should be called near the end of the device's

 *    runtime_resume callback.

 */

void blk_post_runtime_resume(struct request_queue *q, int err)

{

	if (!q->dev)

		return;



	spin_lock_irq(q->queue_lock);

	if (!err) {

		q->rpm_status = RPM_ACTIVE;

		__blk_run_queue(q);

		pm_runtime_mark_last_busy(q->dev);

		pm_request_autosuspend(q->dev);

	} else {

		q->rpm_status = RPM_SUSPENDED;

	}

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_post_runtime_resume);



/**

 * blk_set_runtime_active - Force runtime status of the queue to be active

 * @q: the queue of the device

 *

 * If the device is left runtime suspended during system suspend the resume

 * hook typically resumes the device and corrects runtime status

 * accordingly. However, that does not affect the queue runtime PM status

 * which is still "suspended". This prevents processing requests from the

 * queue.

 *

 * This function can be used in driver's resume hook to correct queue

 * runtime PM status and re-enable peeking requests from the queue. It

 * should be called before first request is added to the queue.

 */

void blk_set_runtime_active(struct request_queue *q)

{

	spin_lock_irq(q->queue_lock);

	q->rpm_status = RPM_ACTIVE;

	pm_runtime_mark_last_busy(q->dev);

	pm_request_autosuspend(q->dev);

	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL(blk_set_runtime_active);

block/blk-pm.h

0 → 100644
+43 −0
Original line number Diff line number Diff line 
/* 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_ */