1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/blk-mq.h>
4 #include <linux/blk-pm.h>
7 #include "blk-mq.h"
8 #include "blk-mq-tag.h"
11  * blk_pm_runtime_init - Block layer runtime PM initialization routine
16  *    Initialize runtime-PM-related fields for @q and start auto suspend for
17  *    @dev. Drivers that want to take advantage of request-based runtime PM
24  *    the autosuspend delay is set to -1 to make runtime suspend impossible
26  *    not need to touch other autosuspend settings.
33 	q->dev = dev;  in blk_pm_runtime_init()
34 	q->rpm_status = RPM_ACTIVE;  in blk_pm_runtime_init()
35 	pm_runtime_set_autosuspend_delay(q->dev, -1);  in blk_pm_runtime_init()
36 	pm_runtime_use_autosuspend(q->dev);  in blk_pm_runtime_init()
41  * blk_pre_runtime_suspend - Pre runtime suspend check
52  *    runtime PM core will try to autosuspend it some time later.
58  *    0		- OK to runtime suspend the device
59  *    -EBUSY	- Device should not be runtime suspended
65 	if (!q->dev)  in blk_pre_runtime_suspend()
68 	WARN_ON_ONCE(q->rpm_status != RPM_ACTIVE);  in blk_pre_runtime_suspend()
72 	 * non-PM blk_queue_enter() calls are in progress to avoid that any  in blk_pre_runtime_suspend()
73 	 * new non-PM blk_queue_enter() calls succeed before the pm_only  in blk_pre_runtime_suspend()
77 	ret = -EBUSY;  in blk_pre_runtime_suspend()
78 	/* Switch q_usage_counter from per-cpu to atomic mode. */  in blk_pre_runtime_suspend()
83 	 * blk_queue_enter() calls see the pm-only state. See also  in blk_pre_runtime_suspend()
86 	percpu_ref_switch_to_atomic_sync(&q->q_usage_counter);  in blk_pre_runtime_suspend()
87 	if (percpu_ref_is_zero(&q->q_usage_counter))  in blk_pre_runtime_suspend()
89 	/* Switch q_usage_counter back to per-cpu mode. */  in blk_pre_runtime_suspend()
92 	spin_lock_irq(&q->queue_lock);  in blk_pre_runtime_suspend()
94 		pm_runtime_mark_last_busy(q->dev);  in blk_pre_runtime_suspend()
96 		q->rpm_status = RPM_SUSPENDING;  in blk_pre_runtime_suspend()
97 	spin_unlock_irq(&q->queue_lock);  in blk_pre_runtime_suspend()
107  * blk_post_runtime_suspend - Post runtime suspend processing
121 	if (!q->dev)  in blk_post_runtime_suspend()
124 	spin_lock_irq(&q->queue_lock);  in blk_post_runtime_suspend()
126 		q->rpm_status = RPM_SUSPENDED;  in blk_post_runtime_suspend()
128 		q->rpm_status = RPM_ACTIVE;  in blk_post_runtime_suspend()
129 		pm_runtime_mark_last_busy(q->dev);  in blk_post_runtime_suspend()
131 	spin_unlock_irq(&q->queue_lock);  in blk_post_runtime_suspend()
139  * blk_pre_runtime_resume - Pre runtime resume processing
151 	if (!q->dev)  in blk_pre_runtime_resume()
154 	spin_lock_irq(&q->queue_lock);  in blk_pre_runtime_resume()
155 	q->rpm_status = RPM_RESUMING;  in blk_pre_runtime_resume()
156 	spin_unlock_irq(&q->queue_lock);  in blk_pre_runtime_resume()
161  * blk_post_runtime_resume - Post runtime resume processing
175 	if (!q->dev)  in blk_post_runtime_resume()
180 		spin_lock_irq(&q->queue_lock);  in blk_post_runtime_resume()
181 		q->rpm_status = RPM_SUSPENDED;  in blk_post_runtime_resume()
182 		spin_unlock_irq(&q->queue_lock);  in blk_post_runtime_resume()
188  * blk_set_runtime_active - Force runtime status of the queue to be active
198  * runtime PM status and re-enable peeking requests from the queue. It
208 	if (!q->dev)  in blk_set_runtime_active()
211 	spin_lock_irq(&q->queue_lock);  in blk_set_runtime_active()
212 	old_status = q->rpm_status;  in blk_set_runtime_active()
213 	q->rpm_status = RPM_ACTIVE;  in blk_set_runtime_active()
214 	pm_runtime_mark_last_busy(q->dev);  in blk_set_runtime_active()
215 	pm_request_autosuspend(q->dev);  in blk_set_runtime_active()
216 	spin_unlock_irq(&q->queue_lock);  in blk_set_runtime_active()