1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/blk-pm.h>
6 #include "blk-mq.h"
9  * blk_pm_runtime_init - Block layer runtime PM initialization routine
14  *    Initialize runtime-PM-related fields for @q and start auto suspend for
15  *    @dev. Drivers that want to take advantage of request-based runtime PM
22  *    the autosuspend delay is set to -1 to make runtime suspend impossible
31 	q->dev = dev;  in blk_pm_runtime_init()
32 	q->rpm_status = RPM_ACTIVE;  in blk_pm_runtime_init()
33 	pm_runtime_set_autosuspend_delay(q->dev, -1);  in blk_pm_runtime_init()
34 	pm_runtime_use_autosuspend(q->dev);  in blk_pm_runtime_init()
39  * blk_pre_runtime_suspend - Pre runtime suspend check
56  *    0		- OK to runtime suspend the device
57  *    -EBUSY	- Device should not be runtime suspended
63 	if (!q->dev)  in blk_pre_runtime_suspend()
66 	WARN_ON_ONCE(q->rpm_status != RPM_ACTIVE);  in blk_pre_runtime_suspend()
68 	spin_lock_irq(&q->queue_lock);  in blk_pre_runtime_suspend()
69 	q->rpm_status = RPM_SUSPENDING;  in blk_pre_runtime_suspend()
70 	spin_unlock_irq(&q->queue_lock);  in blk_pre_runtime_suspend()
74 	 * non-PM blk_queue_enter() calls are in progress to avoid that any  in blk_pre_runtime_suspend()
75 	 * new non-PM blk_queue_enter() calls succeed before the pm_only  in blk_pre_runtime_suspend()
79 	ret = -EBUSY;  in blk_pre_runtime_suspend()
80 	/* Switch q_usage_counter from per-cpu to atomic mode. */  in blk_pre_runtime_suspend()
85 	 * blk_queue_enter() calls see the pm-only state. See also  in blk_pre_runtime_suspend()
88 	percpu_ref_switch_to_atomic_sync(&q->q_usage_counter);  in blk_pre_runtime_suspend()
89 	if (percpu_ref_is_zero(&q->q_usage_counter))  in blk_pre_runtime_suspend()
91 	/* Switch q_usage_counter back to per-cpu mode. */  in blk_pre_runtime_suspend()
95 		spin_lock_irq(&q->queue_lock);  in blk_pre_runtime_suspend()
96 		q->rpm_status = RPM_ACTIVE;  in blk_pre_runtime_suspend()
97 		pm_runtime_mark_last_busy(q->dev);  in blk_pre_runtime_suspend()
98 		spin_unlock_irq(&q->queue_lock);  in blk_pre_runtime_suspend()
108  * blk_post_runtime_suspend - Post runtime suspend processing
122 	if (!q->dev)  in blk_post_runtime_suspend()
125 	spin_lock_irq(&q->queue_lock);  in blk_post_runtime_suspend()
127 		q->rpm_status = RPM_SUSPENDED;  in blk_post_runtime_suspend()
129 		q->rpm_status = RPM_ACTIVE;  in blk_post_runtime_suspend()
130 		pm_runtime_mark_last_busy(q->dev);  in blk_post_runtime_suspend()
132 	spin_unlock_irq(&q->queue_lock);  in blk_post_runtime_suspend()
140  * blk_pre_runtime_resume - Pre runtime resume processing
152 	if (!q->dev)  in blk_pre_runtime_resume()
155 	spin_lock_irq(&q->queue_lock);  in blk_pre_runtime_resume()
156 	q->rpm_status = RPM_RESUMING;  in blk_pre_runtime_resume()
157 	spin_unlock_irq(&q->queue_lock);  in blk_pre_runtime_resume()
162  * blk_post_runtime_resume - Post runtime resume processing
167  *    of whether the device's runtime-resume succeeded; even if it failed the
171  *    runtime_resume callback to correct queue runtime PM status and re-enable
178 	if (!q->dev)  in blk_post_runtime_resume()
181 	spin_lock_irq(&q->queue_lock);  in blk_post_runtime_resume()
182 	old_status = q->rpm_status;  in blk_post_runtime_resume()
183 	q->rpm_status = RPM_ACTIVE;  in blk_post_runtime_resume()
184 	pm_runtime_mark_last_busy(q->dev);  in blk_post_runtime_resume()
185 	pm_request_autosuspend(q->dev);  in blk_post_runtime_resume()
186 	spin_unlock_irq(&q->queue_lock);  in blk_post_runtime_resume()