| // SPDX-License-Identifier: GPL-2.0 |
| |
| #include <linux/blk-mq.h> |
| #include <linux/blk-pm.h> |
| #include <linux/blkdev.h> |
| #include <linux/pm_runtime.h> |
| #include "blk-mq.h" |
| #include "blk-mq-tag.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) |
| { |
| 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; |
| |
| WARN_ON_ONCE(q->rpm_status != RPM_ACTIVE); |
| |
| spin_lock_irq(&q->queue_lock); |
| q->rpm_status = RPM_SUSPENDING; |
| spin_unlock_irq(&q->queue_lock); |
| |
| /* |
| * Increase the pm_only counter before checking whether any |
| * non-PM blk_queue_enter() calls are in progress to avoid that any |
| * new non-PM blk_queue_enter() calls succeed before the pm_only |
| * counter is decreased again. |
| */ |
| blk_set_pm_only(q); |
| ret = -EBUSY; |
| /* Switch q_usage_counter from per-cpu to atomic mode. */ |
| blk_freeze_queue_start(q); |
| /* |
| * Wait until atomic mode has been reached. Since that |
| * involves calling call_rcu(), it is guaranteed that later |
| * blk_queue_enter() calls see the pm-only state. See also |
| * http://lwn.net/Articles/573497/. |
| */ |
| percpu_ref_switch_to_atomic_sync(&q->q_usage_counter); |
| if (percpu_ref_is_zero(&q->q_usage_counter)) |
| ret = 0; |
| /* Switch q_usage_counter back to per-cpu mode. */ |
| blk_mq_unfreeze_queue(q); |
| |
| if (ret < 0) { |
| spin_lock_irq(&q->queue_lock); |
| q->rpm_status = RPM_ACTIVE; |
| pm_runtime_mark_last_busy(q->dev); |
| spin_unlock_irq(&q->queue_lock); |
| |
| blk_clear_pm_only(q); |
| } |
| |
| 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); |
| |
| if (err) |
| blk_clear_pm_only(q); |
| } |
| 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; |
| pm_runtime_mark_last_busy(q->dev); |
| pm_request_autosuspend(q->dev); |
| } else { |
| q->rpm_status = RPM_SUSPENDED; |
| } |
| spin_unlock_irq(&q->queue_lock); |
| |
| if (!err) |
| blk_clear_pm_only(q); |
| } |
| 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) |
| { |
| if (q->dev) { |
| 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); |