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 <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph 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: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-core.c b/block/blk-core.c
index 4dbc93f..6d4dd17 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -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));