1 files changed, 29 insertions, 241 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index cff0a60ee200..f12d2b65e5a5 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
@@ -421,24 +422,25 @@ void blk_sync_queue(struct request_queue *q)
 EXPORT_SYMBOL(blk_sync_queue);
 
 /**
- * blk_set_preempt_only - set QUEUE_FLAG_PREEMPT_ONLY
+ * blk_set_pm_only - increment pm_only counter
  * @q: request queue pointer
- *
- * Returns the previous value of the PREEMPT_ONLY flag - 0 if the flag was not
- * set and 1 if the flag was already set.
  */
-int blk_set_preempt_only(struct request_queue *q)
+void blk_set_pm_only(struct request_queue *q)
 {
-	return blk_queue_flag_test_and_set(QUEUE_FLAG_PREEMPT_ONLY, q);
+	atomic_inc(&q->pm_only);
 }
-EXPORT_SYMBOL_GPL(blk_set_preempt_only);
+EXPORT_SYMBOL_GPL(blk_set_pm_only);
 
-void blk_clear_preempt_only(struct request_queue *q)
+void blk_clear_pm_only(struct request_queue *q)
 {
-	blk_queue_flag_clear(QUEUE_FLAG_PREEMPT_ONLY, q);
-	wake_up_all(&q->mq_freeze_wq);
+	int pm_only;
+
+	pm_only = atomic_dec_return(&q->pm_only);
+	WARN_ON_ONCE(pm_only < 0);
+	if (pm_only == 0)
+		wake_up_all(&q->mq_freeze_wq);
 }
-EXPORT_SYMBOL_GPL(blk_clear_preempt_only);
+EXPORT_SYMBOL_GPL(blk_clear_pm_only);
 
 /**
  * __blk_run_queue_uncond - run a queue whether or not it has been stopped
@@ -917,7 +919,7 @@ EXPORT_SYMBOL(blk_alloc_queue);
  */
 int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 {
-	const bool preempt = flags & BLK_MQ_REQ_PREEMPT;
+	const bool pm = flags & BLK_MQ_REQ_PREEMPT;
 
 	while (true) {
 		bool success = false;
@@ -925,11 +927,11 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 		rcu_read_lock();
 		if (percpu_ref_tryget_live(&q->q_usage_counter)) {
 			/*
-			 * The code that sets the PREEMPT_ONLY flag is
-			 * responsible for ensuring that that flag is globally
-			 * visible before the queue is unfrozen.
+			 * The code that increments the pm_only counter is
+			 * responsible for ensuring that that counter is
+			 * globally visible before the queue is unfrozen.
 			 */
-			if (preempt || !blk_queue_preempt_only(q)) {
+			if (pm || !blk_queue_pm_only(q)) {
 				success = true;
 			} else {
 				percpu_ref_put(&q->q_usage_counter);
@@ -954,7 +956,8 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 
 		wait_event(q->mq_freeze_wq,
 			   (atomic_read(&q->mq_freeze_depth) == 0 &&
-			    (preempt || !blk_queue_preempt_only(q))) ||
+			    (pm || (blk_pm_request_resume(q),
+				    !blk_queue_pm_only(q)))) ||
 			   blk_queue_dying(q));
 		if (blk_queue_dying(q))
 			return -ENODEV;
@@ -1726,16 +1729,6 @@ 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;
@@ -1752,6 +1745,7 @@ void __blk_put_request(struct request_queue *q, struct request *req)
 
 	blk_req_zone_write_unlock(req);
 	blk_pm_put_request(req);
+	blk_pm_mark_last_busy(req);
 
 	elv_completed_request(q, req);
 
@@ -2750,30 +2744,6 @@ void blk_account_io_done(struct request *req, u64 now)
 	}
 }
 
-#ifdef CONFIG_PM
-/*
- * Don't process normal requests when queue is suspended
- * or in the process of suspending/resuming
- */
-static bool blk_pm_allow_request(struct request *rq)
-{
-	switch (rq->q->rpm_status) {
-	case RPM_RESUMING:
-	case RPM_SUSPENDING:
-		return rq->rq_flags & RQF_PM;
-	case RPM_SUSPENDED:
-		return false;
-	default:
-		return true;
-	}
-}
-#else
-static bool blk_pm_allow_request(struct request *rq)
-{
-	return true;
-}
-#endif
-
 void blk_account_io_start(struct request *rq, bool new_io)
 {
 	struct hd_struct *part;
@@ -2819,11 +2789,14 @@ static struct request *elv_next_request(struct request_queue *q)
 
 	while (1) {
 		list_for_each_entry(rq, &q->queue_head, queuelist) {
-			if (blk_pm_allow_request(rq))
-				return rq;
-
-			if (rq->rq_flags & RQF_SOFTBARRIER)
-				break;
+#ifdef CONFIG_PM
+			/*
+			 * If a request gets queued in state RPM_SUSPENDED
+			 * then that's a kernel bug.
+			 */
+			WARN_ON_ONCE(q->rpm_status == RPM_SUSPENDED);
+#endif
+			return rq;
 		}
 
 		/*
@@ -3755,191 +3728,6 @@ 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));