| /* |
| * drivers/base/power/runtime.c - Helper functions for device runtime PM |
| * |
| * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. |
| * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu> |
| * |
| * This file is released under the GPLv2. |
| */ |
| |
| #include <linux/sched/mm.h> |
| #include <linux/ktime.h> |
| #include <linux/hrtimer.h> |
| #include <linux/export.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/pm_wakeirq.h> |
| #include <trace/events/rpm.h> |
| |
| #include "../base.h" |
| #include "power.h" |
| |
| typedef int (*pm_callback_t)(struct device *); |
| |
| static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset) |
| { |
| pm_callback_t cb; |
| const struct dev_pm_ops *ops; |
| |
| if (dev->pm_domain) |
| ops = &dev->pm_domain->ops; |
| else if (dev->type && dev->type->pm) |
| ops = dev->type->pm; |
| else if (dev->class && dev->class->pm) |
| ops = dev->class->pm; |
| else if (dev->bus && dev->bus->pm) |
| ops = dev->bus->pm; |
| else |
| ops = NULL; |
| |
| if (ops) |
| cb = *(pm_callback_t *)((void *)ops + cb_offset); |
| else |
| cb = NULL; |
| |
| if (!cb && dev->driver && dev->driver->pm) |
| cb = *(pm_callback_t *)((void *)dev->driver->pm + cb_offset); |
| |
| return cb; |
| } |
| |
| #define RPM_GET_CALLBACK(dev, callback) \ |
| __rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback)) |
| |
| static int rpm_resume(struct device *dev, int rpmflags); |
| static int rpm_suspend(struct device *dev, int rpmflags); |
| |
| /** |
| * update_pm_runtime_accounting - Update the time accounting of power states |
| * @dev: Device to update the accounting for |
| * |
| * In order to be able to have time accounting of the various power states |
| * (as used by programs such as PowerTOP to show the effectiveness of runtime |
| * PM), we need to track the time spent in each state. |
| * update_pm_runtime_accounting must be called each time before the |
| * runtime_status field is updated, to account the time in the old state |
| * correctly. |
| */ |
| void update_pm_runtime_accounting(struct device *dev) |
| { |
| unsigned long now = jiffies; |
| unsigned long delta; |
| |
| delta = now - dev->power.accounting_timestamp; |
| |
| dev->power.accounting_timestamp = now; |
| |
| if (dev->power.disable_depth > 0) |
| return; |
| |
| if (dev->power.runtime_status == RPM_SUSPENDED) |
| dev->power.suspended_jiffies += delta; |
| else |
| dev->power.active_jiffies += delta; |
| } |
| |
| static void __update_runtime_status(struct device *dev, enum rpm_status status) |
| { |
| update_pm_runtime_accounting(dev); |
| dev->power.runtime_status = status; |
| } |
| |
| /** |
| * pm_runtime_deactivate_timer - Deactivate given device's suspend timer. |
| * @dev: Device to handle. |
| */ |
| static void pm_runtime_deactivate_timer(struct device *dev) |
| { |
| if (dev->power.timer_expires > 0) { |
| hrtimer_cancel(&dev->power.suspend_timer); |
| dev->power.timer_expires = 0; |
| } |
| } |
| |
| /** |
| * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests. |
| * @dev: Device to handle. |
| */ |
| static void pm_runtime_cancel_pending(struct device *dev) |
| { |
| pm_runtime_deactivate_timer(dev); |
| /* |
| * In case there's a request pending, make sure its work function will |
| * return without doing anything. |
| */ |
| dev->power.request = RPM_REQ_NONE; |
| } |
| |
| /* |
| * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time. |
| * @dev: Device to handle. |
| * |
| * Compute the autosuspend-delay expiration time based on the device's |
| * power.last_busy time. If the delay has already expired or is disabled |
| * (negative) or the power.use_autosuspend flag isn't set, return 0. |
| * Otherwise return the expiration time in jiffies (adjusted to be nonzero). |
| * |
| * This function may be called either with or without dev->power.lock held. |
| * Either way it can be racy, since power.last_busy may be updated at any time. |
| */ |
| u64 pm_runtime_autosuspend_expiration(struct device *dev) |
| { |
| int autosuspend_delay; |
| u64 last_busy, expires = 0; |
| u64 now = ktime_to_ns(ktime_get()); |
| |
| if (!dev->power.use_autosuspend) |
| goto out; |
| |
| autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay); |
| if (autosuspend_delay < 0) |
| goto out; |
| |
| last_busy = READ_ONCE(dev->power.last_busy); |
| |
| expires = last_busy + autosuspend_delay * NSEC_PER_MSEC; |
| if (expires <= now) |
| expires = 0; /* Already expired. */ |
| |
| out: |
| return expires; |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration); |
| |
| static int dev_memalloc_noio(struct device *dev, void *data) |
| { |
| return dev->power.memalloc_noio; |
| } |
| |
| /* |
| * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag. |
| * @dev: Device to handle. |
| * @enable: True for setting the flag and False for clearing the flag. |
| * |
| * Set the flag for all devices in the path from the device to the |
| * root device in the device tree if @enable is true, otherwise clear |
| * the flag for devices in the path whose siblings don't set the flag. |
| * |
| * The function should only be called by block device, or network |
| * device driver for solving the deadlock problem during runtime |
| * resume/suspend: |
| * |
| * If memory allocation with GFP_KERNEL is called inside runtime |
| * resume/suspend callback of any one of its ancestors(or the |
| * block device itself), the deadlock may be triggered inside the |
| * memory allocation since it might not complete until the block |
| * device becomes active and the involed page I/O finishes. The |
| * situation is pointed out first by Alan Stern. Network device |
| * are involved in iSCSI kind of situation. |
| * |
| * The lock of dev_hotplug_mutex is held in the function for handling |
| * hotplug race because pm_runtime_set_memalloc_noio() may be called |
| * in async probe(). |
| * |
| * The function should be called between device_add() and device_del() |
| * on the affected device(block/network device). |
| */ |
| void pm_runtime_set_memalloc_noio(struct device *dev, bool enable) |
| { |
| static DEFINE_MUTEX(dev_hotplug_mutex); |
| |
| mutex_lock(&dev_hotplug_mutex); |
| for (;;) { |
| bool enabled; |
| |
| /* hold power lock since bitfield is not SMP-safe. */ |
| spin_lock_irq(&dev->power.lock); |
| enabled = dev->power.memalloc_noio; |
| dev->power.memalloc_noio = enable; |
| spin_unlock_irq(&dev->power.lock); |
| |
| /* |
| * not need to enable ancestors any more if the device |
| * has been enabled. |
| */ |
| if (enabled && enable) |
| break; |
| |
| dev = dev->parent; |
| |
| /* |
| * clear flag of the parent device only if all the |
| * children don't set the flag because ancestor's |
| * flag was set by any one of the descendants. |
| */ |
| if (!dev || (!enable && |
| device_for_each_child(dev, NULL, |
| dev_memalloc_noio))) |
| break; |
| } |
| mutex_unlock(&dev_hotplug_mutex); |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio); |
| |
| /** |
| * rpm_check_suspend_allowed - Test whether a device may be suspended. |
| * @dev: Device to test. |
| */ |
| static int rpm_check_suspend_allowed(struct device *dev) |
| { |
| int retval = 0; |
| |
| if (dev->power.runtime_error) |
| retval = -EINVAL; |
| else if (dev->power.disable_depth > 0) |
| retval = -EACCES; |
| else if (atomic_read(&dev->power.usage_count) > 0) |
| retval = -EAGAIN; |
| else if (!dev->power.ignore_children && |
| atomic_read(&dev->power.child_count)) |
| retval = -EBUSY; |
| |
| /* Pending resume requests take precedence over suspends. */ |
| else if ((dev->power.deferred_resume |
| && dev->power.runtime_status == RPM_SUSPENDING) |
| || (dev->power.request_pending |
| && dev->power.request == RPM_REQ_RESUME)) |
| retval = -EAGAIN; |
| else if (__dev_pm_qos_read_value(dev) == 0) |
| retval = -EPERM; |
| else if (dev->power.runtime_status == RPM_SUSPENDED) |
| retval = 1; |
| |
| return retval; |
| } |
| |
| static int rpm_get_suppliers(struct device *dev) |
| { |
| struct device_link *link; |
| |
| list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) { |
| int retval; |
| |
| if (!(link->flags & DL_FLAG_PM_RUNTIME)) |
| continue; |
| |
| if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND || |
| link->rpm_active) |
| continue; |
| |
| retval = pm_runtime_get_sync(link->supplier); |
| /* Ignore suppliers with disabled runtime PM. */ |
| if (retval < 0 && retval != -EACCES) { |
| pm_runtime_put_noidle(link->supplier); |
| return retval; |
| } |
| link->rpm_active = true; |
| } |
| return 0; |
| } |
| |
| static void rpm_put_suppliers(struct device *dev) |
| { |
| struct device_link *link; |
| |
| list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) |
| if (link->rpm_active && |
| READ_ONCE(link->status) != DL_STATE_SUPPLIER_UNBIND) { |
| pm_runtime_put(link->supplier); |
| link->rpm_active = false; |
| } |
| } |
| |
| /** |
| * __rpm_callback - Run a given runtime PM callback for a given device. |
| * @cb: Runtime PM callback to run. |
| * @dev: Device to run the callback for. |
| */ |
| static int __rpm_callback(int (*cb)(struct device *), struct device *dev) |
| __releases(&dev->power.lock) __acquires(&dev->power.lock) |
| { |
| int retval, idx; |
| bool use_links = dev->power.links_count > 0; |
| |
| if (dev->power.irq_safe) { |
| spin_unlock(&dev->power.lock); |
| } else { |
| spin_unlock_irq(&dev->power.lock); |
| |
| /* |
| * Resume suppliers if necessary. |
| * |
| * The device's runtime PM status cannot change until this |
| * routine returns, so it is safe to read the status outside of |
| * the lock. |
| */ |
| if (use_links && dev->power.runtime_status == RPM_RESUMING) { |
| idx = device_links_read_lock(); |
| |
| retval = rpm_get_suppliers(dev); |
| if (retval) |
| goto fail; |
| |
| device_links_read_unlock(idx); |
| } |
| } |
| |
| retval = cb(dev); |
| |
| if (dev->power.irq_safe) { |
| spin_lock(&dev->power.lock); |
| } else { |
| /* |
| * If the device is suspending and the callback has returned |
| * success, drop the usage counters of the suppliers that have |
| * been reference counted on its resume. |
| * |
| * Do that if resume fails too. |
| */ |
| if (use_links |
| && ((dev->power.runtime_status == RPM_SUSPENDING && !retval) |
| || (dev->power.runtime_status == RPM_RESUMING && retval))) { |
| idx = device_links_read_lock(); |
| |
| fail: |
| rpm_put_suppliers(dev); |
| |
| device_links_read_unlock(idx); |
| } |
| |
| spin_lock_irq(&dev->power.lock); |
| } |
| |
| return retval; |
| } |
| |
| /** |
| * rpm_idle - Notify device bus type if the device can be suspended. |
| * @dev: Device to notify the bus type about. |
| * @rpmflags: Flag bits. |
| * |
| * Check if the device's runtime PM status allows it to be suspended. If |
| * another idle notification has been started earlier, return immediately. If |
| * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise |
| * run the ->runtime_idle() callback directly. If the ->runtime_idle callback |
| * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag. |
| * |
| * This function must be called under dev->power.lock with interrupts disabled. |
| */ |
| static int rpm_idle(struct device *dev, int rpmflags) |
| { |
| int (*callback)(struct device *); |
| int retval; |
| |
| trace_rpm_idle_rcuidle(dev, rpmflags); |
| retval = rpm_check_suspend_allowed(dev); |
| if (retval < 0) |
| ; /* Conditions are wrong. */ |
| |
| /* Idle notifications are allowed only in the RPM_ACTIVE state. */ |
| else if (dev->power.runtime_status != RPM_ACTIVE) |
| retval = -EAGAIN; |
| |
| /* |
| * Any pending request other than an idle notification takes |
| * precedence over us, except that the timer may be running. |
| */ |
| else if (dev->power.request_pending && |
| dev->power.request > RPM_REQ_IDLE) |
| retval = -EAGAIN; |
| |
| /* Act as though RPM_NOWAIT is always set. */ |
| else if (dev->power.idle_notification) |
| retval = -EINPROGRESS; |
| if (retval) |
| goto out; |
| |
| /* Pending requests need to be canceled. */ |
| dev->power.request = RPM_REQ_NONE; |
| |
| if (dev->power.no_callbacks) |
| goto out; |
| |
| /* Carry out an asynchronous or a synchronous idle notification. */ |
| if (rpmflags & RPM_ASYNC) { |
| dev->power.request = RPM_REQ_IDLE; |
| if (!dev->power.request_pending) { |
| dev->power.request_pending = true; |
| queue_work(pm_wq, &dev->power.work); |
| } |
| trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0); |
| return 0; |
| } |
| |
| dev->power.idle_notification = true; |
| |
| callback = RPM_GET_CALLBACK(dev, runtime_idle); |
| |
| if (callback) |
| retval = __rpm_callback(callback, dev); |
| |
| dev->power.idle_notification = false; |
| wake_up_all(&dev->power.wait_queue); |
| |
| out: |
| trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval); |
| return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO); |
| } |
| |
| /** |
| * rpm_callback - Run a given runtime PM callback for a given device. |
| * @cb: Runtime PM callback to run. |
| * @dev: Device to run the callback for. |
| */ |
| static int rpm_callback(int (*cb)(struct device *), struct device *dev) |
| { |
| int retval; |
| |
| if (!cb) |
| return -ENOSYS; |
| |
| if (dev->power.memalloc_noio) { |
| unsigned int noio_flag; |
| |
| /* |
| * Deadlock might be caused if memory allocation with |
| * GFP_KERNEL happens inside runtime_suspend and |
| * runtime_resume callbacks of one block device's |
| * ancestor or the block device itself. Network |
| * device might be thought as part of iSCSI block |
| * device, so network device and its ancestor should |
| * be marked as memalloc_noio too. |
| */ |
| noio_flag = memalloc_noio_save(); |
| retval = __rpm_callback(cb, dev); |
| memalloc_noio_restore(noio_flag); |
| } else { |
| retval = __rpm_callback(cb, dev); |
| } |
| |
| dev->power.runtime_error = retval; |
| return retval != -EACCES ? retval : -EIO; |
| } |
| |
| /** |
| * rpm_suspend - Carry out runtime suspend of given device. |
| * @dev: Device to suspend. |
| * @rpmflags: Flag bits. |
| * |
| * Check if the device's runtime PM status allows it to be suspended. |
| * Cancel a pending idle notification, autosuspend or suspend. If |
| * another suspend has been started earlier, either return immediately |
| * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC |
| * flags. If the RPM_ASYNC flag is set then queue a suspend request; |
| * otherwise run the ->runtime_suspend() callback directly. When |
| * ->runtime_suspend succeeded, if a deferred resume was requested while |
| * the callback was running then carry it out, otherwise send an idle |
| * notification for its parent (if the suspend succeeded and both |
| * ignore_children of parent->power and irq_safe of dev->power are not set). |
| * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO |
| * flag is set and the next autosuspend-delay expiration time is in the |
| * future, schedule another autosuspend attempt. |
| * |
| * This function must be called under dev->power.lock with interrupts disabled. |
| */ |
| static int rpm_suspend(struct device *dev, int rpmflags) |
| __releases(&dev->power.lock) __acquires(&dev->power.lock) |
| { |
| int (*callback)(struct device *); |
| struct device *parent = NULL; |
| int retval; |
| |
| trace_rpm_suspend_rcuidle(dev, rpmflags); |
| |
| repeat: |
| retval = rpm_check_suspend_allowed(dev); |
| |
| if (retval < 0) |
| ; /* Conditions are wrong. */ |
| |
| /* Synchronous suspends are not allowed in the RPM_RESUMING state. */ |
| else if (dev->power.runtime_status == RPM_RESUMING && |
| !(rpmflags & RPM_ASYNC)) |
| retval = -EAGAIN; |
| if (retval) |
| goto out; |
| |
| /* If the autosuspend_delay time hasn't expired yet, reschedule. */ |
| if ((rpmflags & RPM_AUTO) |
| && dev->power.runtime_status != RPM_SUSPENDING) { |
| u64 expires = pm_runtime_autosuspend_expiration(dev); |
| |
| if (expires != 0) { |
| /* Pending requests need to be canceled. */ |
| dev->power.request = RPM_REQ_NONE; |
| |
| /* |
| * Optimization: If the timer is already running and is |
| * set to expire at or before the autosuspend delay, |
| * avoid the overhead of resetting it. Just let it |
| * expire; pm_suspend_timer_fn() will take care of the |
| * rest. |
| */ |
| if (!(dev->power.timer_expires && |
| dev->power.timer_expires <= expires)) { |
| /* |
| * We add a slack of 25% to gather wakeups |
| * without sacrificing the granularity. |
| */ |
| u64 slack = READ_ONCE(dev->power.autosuspend_delay) * |
| (NSEC_PER_MSEC >> 2); |
| |
| dev->power.timer_expires = expires; |
| hrtimer_start_range_ns(&dev->power.suspend_timer, |
| ns_to_ktime(expires), |
| slack, |
| HRTIMER_MODE_ABS); |
| } |
| dev->power.timer_autosuspends = 1; |
| goto out; |
| } |
| } |
| |
| /* Other scheduled or pending requests need to be canceled. */ |
| pm_runtime_cancel_pending(dev); |
| |
| if (dev->power.runtime_status == RPM_SUSPENDING) { |
| DEFINE_WAIT(wait); |
| |
| if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { |
| retval = -EINPROGRESS; |
| goto out; |
| } |
| |
| if (dev->power.irq_safe) { |
| spin_unlock(&dev->power.lock); |
| |
| cpu_relax(); |
| |
| spin_lock(&dev->power.lock); |
| goto repeat; |
| } |
| |
| /* Wait for the other suspend running in parallel with us. */ |
| for (;;) { |
| prepare_to_wait(&dev->power.wait_queue, &wait, |
| TASK_UNINTERRUPTIBLE); |
| if (dev->power.runtime_status != RPM_SUSPENDING) |
| break; |
| |
| spin_unlock_irq(&dev->power.lock); |
| |
| schedule(); |
| |
| spin_lock_irq(&dev->power.lock); |
| } |
| finish_wait(&dev->power.wait_queue, &wait); |
| goto repeat; |
| } |
| |
| if (dev->power.no_callbacks) |
| goto no_callback; /* Assume success. */ |
| |
| /* Carry out an asynchronous or a synchronous suspend. */ |
| if (rpmflags & RPM_ASYNC) { |
| dev->power.request = (rpmflags & RPM_AUTO) ? |
| RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND; |
| if (!dev->power.request_pending) { |
| dev->power.request_pending = true; |
| queue_work(pm_wq, &dev->power.work); |
| } |
| goto out; |
| } |
| |
| __update_runtime_status(dev, RPM_SUSPENDING); |
| |
| callback = RPM_GET_CALLBACK(dev, runtime_suspend); |
| |
| dev_pm_enable_wake_irq_check(dev, true); |
| retval = rpm_callback(callback, dev); |
| if (retval) |
| goto fail; |
| |
| no_callback: |
| __update_runtime_status(dev, RPM_SUSPENDED); |
| pm_runtime_deactivate_timer(dev); |
| |
| if (dev->parent) { |
| parent = dev->parent; |
| atomic_add_unless(&parent->power.child_count, -1, 0); |
| } |
| wake_up_all(&dev->power.wait_queue); |
| |
| if (dev->power.deferred_resume) { |
| dev->power.deferred_resume = false; |
| rpm_resume(dev, 0); |
| retval = -EAGAIN; |
| goto out; |
| } |
| |
| /* Maybe the parent is now able to suspend. */ |
| if (parent && !parent->power.ignore_children && !dev->power.irq_safe) { |
| spin_unlock(&dev->power.lock); |
| |
| spin_lock(&parent->power.lock); |
| rpm_idle(parent, RPM_ASYNC); |
| spin_unlock(&parent->power.lock); |
| |
| spin_lock(&dev->power.lock); |
| } |
| |
| out: |
| trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval); |
| |
| return retval; |
| |
| fail: |
| dev_pm_disable_wake_irq_check(dev); |
| __update_runtime_status(dev, RPM_ACTIVE); |
| dev->power.deferred_resume = false; |
| wake_up_all(&dev->power.wait_queue); |
| |
| if (retval == -EAGAIN || retval == -EBUSY) { |
| dev->power.runtime_error = 0; |
| |
| /* |
| * If the callback routine failed an autosuspend, and |
| * if the last_busy time has been updated so that there |
| * is a new autosuspend expiration time, automatically |
| * reschedule another autosuspend. |
| */ |
| if ((rpmflags & RPM_AUTO) && |
| pm_runtime_autosuspend_expiration(dev) != 0) |
| goto repeat; |
| } else { |
| pm_runtime_cancel_pending(dev); |
| } |
| goto out; |
| } |
| |
| /** |
| * rpm_resume - Carry out runtime resume of given device. |
| * @dev: Device to resume. |
| * @rpmflags: Flag bits. |
| * |
| * Check if the device's runtime PM status allows it to be resumed. Cancel |
| * any scheduled or pending requests. If another resume has been started |
| * earlier, either return immediately or wait for it to finish, depending on the |
| * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in |
| * parallel with this function, either tell the other process to resume after |
| * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC |
| * flag is set then queue a resume request; otherwise run the |
| * ->runtime_resume() callback directly. Queue an idle notification for the |
| * device if the resume succeeded. |
| * |
| * This function must be called under dev->power.lock with interrupts disabled. |
| */ |
| static int rpm_resume(struct device *dev, int rpmflags) |
| __releases(&dev->power.lock) __acquires(&dev->power.lock) |
| { |
| int (*callback)(struct device *); |
| struct device *parent = NULL; |
| int retval = 0; |
| |
| trace_rpm_resume_rcuidle(dev, rpmflags); |
| |
| repeat: |
| if (dev->power.runtime_error) |
| retval = -EINVAL; |
| else if (dev->power.disable_depth == 1 && dev->power.is_suspended |
| && dev->power.runtime_status == RPM_ACTIVE) |
| retval = 1; |
| else if (dev->power.disable_depth > 0) |
| retval = -EACCES; |
| if (retval) |
| goto out; |
| |
| /* |
| * Other scheduled or pending requests need to be canceled. Small |
| * optimization: If an autosuspend timer is running, leave it running |
| * rather than cancelling it now only to restart it again in the near |
| * future. |
| */ |
| dev->power.request = RPM_REQ_NONE; |
| if (!dev->power.timer_autosuspends) |
| pm_runtime_deactivate_timer(dev); |
| |
| if (dev->power.runtime_status == RPM_ACTIVE) { |
| retval = 1; |
| goto out; |
| } |
| |
| if (dev->power.runtime_status == RPM_RESUMING |
| || dev->power.runtime_status == RPM_SUSPENDING) { |
| DEFINE_WAIT(wait); |
| |
| if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { |
| if (dev->power.runtime_status == RPM_SUSPENDING) |
| dev->power.deferred_resume = true; |
| else |
| retval = -EINPROGRESS; |
| goto out; |
| } |
| |
| if (dev->power.irq_safe) { |
| spin_unlock(&dev->power.lock); |
| |
| cpu_relax(); |
| |
| spin_lock(&dev->power.lock); |
| goto repeat; |
| } |
| |
| /* Wait for the operation carried out in parallel with us. */ |
| for (;;) { |
| prepare_to_wait(&dev->power.wait_queue, &wait, |
| TASK_UNINTERRUPTIBLE); |
| if (dev->power.runtime_status != RPM_RESUMING |
| && dev->power.runtime_status != RPM_SUSPENDING) |
| break; |
| |
| spin_unlock_irq(&dev->power.lock); |
| |
| schedule(); |
| |
| spin_lock_irq(&dev->power.lock); |
| } |
| finish_wait(&dev->power.wait_queue, &wait); |
| goto repeat; |
| } |
| |
| /* |
| * See if we can skip waking up the parent. This is safe only if |
| * power.no_callbacks is set, because otherwise we don't know whether |
| * the resume will actually succeed. |
| */ |
| if (dev->power.no_callbacks && !parent && dev->parent) { |
| spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING); |
| if (dev->parent->power.disable_depth > 0 |
| || dev->parent->power.ignore_children |
| || dev->parent->power.runtime_status == RPM_ACTIVE) { |
| atomic_inc(&dev->parent->power.child_count); |
| spin_unlock(&dev->parent->power.lock); |
| retval = 1; |
| goto no_callback; /* Assume success. */ |
| } |
| spin_unlock(&dev->parent->power.lock); |
| } |
| |
| /* Carry out an asynchronous or a synchronous resume. */ |
| if (rpmflags & RPM_ASYNC) { |
| dev->power.request = RPM_REQ_RESUME; |
| if (!dev->power.request_pending) { |
| dev->power.request_pending = true; |
| queue_work(pm_wq, &dev->power.work); |
| } |
| retval = 0; |
| goto out; |
| } |
| |
| if (!parent && dev->parent) { |
| /* |
| * Increment the parent's usage counter and resume it if |
| * necessary. Not needed if dev is irq-safe; then the |
| * parent is permanently resumed. |
| */ |
| parent = dev->parent; |
| if (dev->power.irq_safe) |
| goto skip_parent; |
| spin_unlock(&dev->power.lock); |
| |
| pm_runtime_get_noresume(parent); |
| |
| spin_lock(&parent->power.lock); |
| /* |
| * Resume the parent if it has runtime PM enabled and not been |
| * set to ignore its children. |
| */ |
| if (!parent->power.disable_depth |
| && !parent->power.ignore_children) { |
| rpm_resume(parent, 0); |
| if (parent->power.runtime_status != RPM_ACTIVE) |
| retval = -EBUSY; |
| } |
| spin_unlock(&parent->power.lock); |
| |
| spin_lock(&dev->power.lock); |
| if (retval) |
| goto out; |
| goto repeat; |
| } |
| skip_parent: |
| |
| if (dev->power.no_callbacks) |
| goto no_callback; /* Assume success. */ |
| |
| __update_runtime_status(dev, RPM_RESUMING); |
| |
| callback = RPM_GET_CALLBACK(dev, runtime_resume); |
| |
| dev_pm_disable_wake_irq_check(dev); |
| retval = rpm_callback(callback, dev); |
| if (retval) { |
| __update_runtime_status(dev, RPM_SUSPENDED); |
| pm_runtime_cancel_pending(dev); |
| dev_pm_enable_wake_irq_check(dev, false); |
| } else { |
| no_callback: |
| __update_runtime_status(dev, RPM_ACTIVE); |
| pm_runtime_mark_last_busy(dev); |
| if (parent) |
| atomic_inc(&parent->power.child_count); |
| } |
| wake_up_all(&dev->power.wait_queue); |
| |
| if (retval >= 0) |
| rpm_idle(dev, RPM_ASYNC); |
| |
| out: |
| if (parent && !dev->power.irq_safe) { |
| spin_unlock_irq(&dev->power.lock); |
| |
| pm_runtime_put(parent); |
| |
| spin_lock_irq(&dev->power.lock); |
| } |
| |
| trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval); |
| |
| return retval; |
| } |
| |
| /** |
| * pm_runtime_work - Universal runtime PM work function. |
| * @work: Work structure used for scheduling the execution of this function. |
| * |
| * Use @work to get the device object the work is to be done for, determine what |
| * is to be done and execute the appropriate runtime PM function. |
| */ |
| static void pm_runtime_work(struct work_struct *work) |
| { |
| struct device *dev = container_of(work, struct device, power.work); |
| enum rpm_request req; |
| |
| spin_lock_irq(&dev->power.lock); |
| |
| if (!dev->power.request_pending) |
| goto out; |
| |
| req = dev->power.request; |
| dev->power.request = RPM_REQ_NONE; |
| dev->power.request_pending = false; |
| |
| switch (req) { |
| case RPM_REQ_NONE: |
| break; |
| case RPM_REQ_IDLE: |
| rpm_idle(dev, RPM_NOWAIT); |
| break; |
| case RPM_REQ_SUSPEND: |
| rpm_suspend(dev, RPM_NOWAIT); |
| break; |
| case RPM_REQ_AUTOSUSPEND: |
| rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO); |
| break; |
| case RPM_REQ_RESUME: |
| rpm_resume(dev, RPM_NOWAIT); |
| break; |
| } |
| |
| out: |
| spin_unlock_irq(&dev->power.lock); |
| } |
| |
| /** |
| * pm_suspend_timer_fn - Timer function for pm_schedule_suspend(). |
| * @data: Device pointer passed by pm_schedule_suspend(). |
| * |
| * Check if the time is right and queue a suspend request. |
| */ |
| static enum hrtimer_restart pm_suspend_timer_fn(struct hrtimer *timer) |
| { |
| struct device *dev = container_of(timer, struct device, power.suspend_timer); |
| unsigned long flags; |
| u64 expires; |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| |
| expires = dev->power.timer_expires; |
| /* If 'expire' is after 'jiffies' we've been called too early. */ |
| if (expires > 0 && expires < ktime_to_ns(ktime_get())) { |
| dev->power.timer_expires = 0; |
| rpm_suspend(dev, dev->power.timer_autosuspends ? |
| (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC); |
| } |
| |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| |
| return HRTIMER_NORESTART; |
| } |
| |
| /** |
| * pm_schedule_suspend - Set up a timer to submit a suspend request in future. |
| * @dev: Device to suspend. |
| * @delay: Time to wait before submitting a suspend request, in milliseconds. |
| */ |
| int pm_schedule_suspend(struct device *dev, unsigned int delay) |
| { |
| unsigned long flags; |
| ktime_t expires; |
| int retval; |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| |
| if (!delay) { |
| retval = rpm_suspend(dev, RPM_ASYNC); |
| goto out; |
| } |
| |
| retval = rpm_check_suspend_allowed(dev); |
| if (retval) |
| goto out; |
| |
| /* Other scheduled or pending requests need to be canceled. */ |
| pm_runtime_cancel_pending(dev); |
| |
| expires = ktime_add(ktime_get(), ms_to_ktime(delay)); |
| dev->power.timer_expires = ktime_to_ns(expires); |
| dev->power.timer_autosuspends = 0; |
| hrtimer_start(&dev->power.suspend_timer, expires, HRTIMER_MODE_ABS); |
| |
| out: |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(pm_schedule_suspend); |
| |
| /** |
| * __pm_runtime_idle - Entry point for runtime idle operations. |
| * @dev: Device to send idle notification for. |
| * @rpmflags: Flag bits. |
| * |
| * If the RPM_GET_PUT flag is set, decrement the device's usage count and |
| * return immediately if it is larger than zero. Then carry out an idle |
| * notification, either synchronous or asynchronous. |
| * |
| * This routine may be called in atomic context if the RPM_ASYNC flag is set, |
| * or if pm_runtime_irq_safe() has been called. |
| */ |
| int __pm_runtime_idle(struct device *dev, int rpmflags) |
| { |
| unsigned long flags; |
| int retval; |
| |
| if (rpmflags & RPM_GET_PUT) { |
| if (!atomic_dec_and_test(&dev->power.usage_count)) |
| return 0; |
| } |
| |
| might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| retval = rpm_idle(dev, rpmflags); |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(__pm_runtime_idle); |
| |
| /** |
| * __pm_runtime_suspend - Entry point for runtime put/suspend operations. |
| * @dev: Device to suspend. |
| * @rpmflags: Flag bits. |
| * |
| * If the RPM_GET_PUT flag is set, decrement the device's usage count and |
| * return immediately if it is larger than zero. Then carry out a suspend, |
| * either synchronous or asynchronous. |
| * |
| * This routine may be called in atomic context if the RPM_ASYNC flag is set, |
| * or if pm_runtime_irq_safe() has been called. |
| */ |
| int __pm_runtime_suspend(struct device *dev, int rpmflags) |
| { |
| unsigned long flags; |
| int retval; |
| |
| if (rpmflags & RPM_GET_PUT) { |
| if (!atomic_dec_and_test(&dev->power.usage_count)) |
| return 0; |
| } |
| |
| might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| retval = rpm_suspend(dev, rpmflags); |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(__pm_runtime_suspend); |
| |
| /** |
| * __pm_runtime_resume - Entry point for runtime resume operations. |
| * @dev: Device to resume. |
| * @rpmflags: Flag bits. |
| * |
| * If the RPM_GET_PUT flag is set, increment the device's usage count. Then |
| * carry out a resume, either synchronous or asynchronous. |
| * |
| * This routine may be called in atomic context if the RPM_ASYNC flag is set, |
| * or if pm_runtime_irq_safe() has been called. |
| */ |
| int __pm_runtime_resume(struct device *dev, int rpmflags) |
| { |
| unsigned long flags; |
| int retval; |
| |
| might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe && |
| dev->power.runtime_status != RPM_ACTIVE); |
| |
| if (rpmflags & RPM_GET_PUT) |
| atomic_inc(&dev->power.usage_count); |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| retval = rpm_resume(dev, rpmflags); |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(__pm_runtime_resume); |
| |
| /** |
| * pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter. |
| * @dev: Device to handle. |
| * |
| * Return -EINVAL if runtime PM is disabled for the device. |
| * |
| * If that's not the case and if the device's runtime PM status is RPM_ACTIVE |
| * and the runtime PM usage counter is nonzero, increment the counter and |
| * return 1. Otherwise return 0 without changing the counter. |
| */ |
| int pm_runtime_get_if_in_use(struct device *dev) |
| { |
| unsigned long flags; |
| int retval; |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| retval = dev->power.disable_depth > 0 ? -EINVAL : |
| dev->power.runtime_status == RPM_ACTIVE |
| && atomic_inc_not_zero(&dev->power.usage_count); |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use); |
| |
| /** |
| * __pm_runtime_set_status - Set runtime PM status of a device. |
| * @dev: Device to handle. |
| * @status: New runtime PM status of the device. |
| * |
| * If runtime PM of the device is disabled or its power.runtime_error field is |
| * different from zero, the status may be changed either to RPM_ACTIVE, or to |
| * RPM_SUSPENDED, as long as that reflects the actual state of the device. |
| * However, if the device has a parent and the parent is not active, and the |
| * parent's power.ignore_children flag is unset, the device's status cannot be |
| * set to RPM_ACTIVE, so -EBUSY is returned in that case. |
| * |
| * If successful, __pm_runtime_set_status() clears the power.runtime_error field |
| * and the device parent's counter of unsuspended children is modified to |
| * reflect the new status. If the new status is RPM_SUSPENDED, an idle |
| * notification request for the parent is submitted. |
| */ |
| int __pm_runtime_set_status(struct device *dev, unsigned int status) |
| { |
| struct device *parent = dev->parent; |
| unsigned long flags; |
| bool notify_parent = false; |
| int error = 0; |
| |
| if (status != RPM_ACTIVE && status != RPM_SUSPENDED) |
| return -EINVAL; |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| |
| if (!dev->power.runtime_error && !dev->power.disable_depth) { |
| error = -EAGAIN; |
| goto out; |
| } |
| |
| if (dev->power.runtime_status == status || !parent) |
| goto out_set; |
| |
| if (status == RPM_SUSPENDED) { |
| atomic_add_unless(&parent->power.child_count, -1, 0); |
| notify_parent = !parent->power.ignore_children; |
| } else { |
| spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING); |
| |
| /* |
| * It is invalid to put an active child under a parent that is |
| * not active, has runtime PM enabled and the |
| * 'power.ignore_children' flag unset. |
| */ |
| if (!parent->power.disable_depth |
| && !parent->power.ignore_children |
| && parent->power.runtime_status != RPM_ACTIVE) { |
| dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n", |
| dev_name(dev), |
| dev_name(parent)); |
| error = -EBUSY; |
| } else if (dev->power.runtime_status == RPM_SUSPENDED) { |
| atomic_inc(&parent->power.child_count); |
| } |
| |
| spin_unlock(&parent->power.lock); |
| |
| if (error) |
| goto out; |
| } |
| |
| out_set: |
| __update_runtime_status(dev, status); |
| dev->power.runtime_error = 0; |
| out: |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| |
| if (notify_parent) |
| pm_request_idle(parent); |
| |
| return error; |
| } |
| EXPORT_SYMBOL_GPL(__pm_runtime_set_status); |
| |
| /** |
| * __pm_runtime_barrier - Cancel pending requests and wait for completions. |
| * @dev: Device to handle. |
| * |
| * Flush all pending requests for the device from pm_wq and wait for all |
| * runtime PM operations involving the device in progress to complete. |
| * |
| * Should be called under dev->power.lock with interrupts disabled. |
| */ |
| static void __pm_runtime_barrier(struct device *dev) |
| { |
| pm_runtime_deactivate_timer(dev); |
| |
| if (dev->power.request_pending) { |
| dev->power.request = RPM_REQ_NONE; |
| spin_unlock_irq(&dev->power.lock); |
| |
| cancel_work_sync(&dev->power.work); |
| |
| spin_lock_irq(&dev->power.lock); |
| dev->power.request_pending = false; |
| } |
| |
| if (dev->power.runtime_status == RPM_SUSPENDING |
| || dev->power.runtime_status == RPM_RESUMING |
| || dev->power.idle_notification) { |
| DEFINE_WAIT(wait); |
| |
| /* Suspend, wake-up or idle notification in progress. */ |
| for (;;) { |
| prepare_to_wait(&dev->power.wait_queue, &wait, |
| TASK_UNINTERRUPTIBLE); |
| if (dev->power.runtime_status != RPM_SUSPENDING |
| && dev->power.runtime_status != RPM_RESUMING |
| && !dev->power.idle_notification) |
| break; |
| spin_unlock_irq(&dev->power.lock); |
| |
| schedule(); |
| |
| spin_lock_irq(&dev->power.lock); |
| } |
| finish_wait(&dev->power.wait_queue, &wait); |
| } |
| } |
| |
| /** |
| * pm_runtime_barrier - Flush pending requests and wait for completions. |
| * @dev: Device to handle. |
| * |
| * Prevent the device from being suspended by incrementing its usage counter and |
| * if there's a pending resume request for the device, wake the device up. |
| * Next, make sure that all pending requests for the device have been flushed |
| * from pm_wq and wait for all runtime PM operations involving the device in |
| * progress to complete. |
| * |
| * Return value: |
| * 1, if there was a resume request pending and the device had to be woken up, |
| * 0, otherwise |
| */ |
| int pm_runtime_barrier(struct device *dev) |
| { |
| int retval = 0; |
| |
| pm_runtime_get_noresume(dev); |
| spin_lock_irq(&dev->power.lock); |
| |
| if (dev->power.request_pending |
| && dev->power.request == RPM_REQ_RESUME) { |
| rpm_resume(dev, 0); |
| retval = 1; |
| } |
| |
| __pm_runtime_barrier(dev); |
| |
| spin_unlock_irq(&dev->power.lock); |
| pm_runtime_put_noidle(dev); |
| |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_barrier); |
| |
| /** |
| * __pm_runtime_disable - Disable runtime PM of a device. |
| * @dev: Device to handle. |
| * @check_resume: If set, check if there's a resume request for the device. |
| * |
| * Increment power.disable_depth for the device and if it was zero previously, |
| * cancel all pending runtime PM requests for the device and wait for all |
| * operations in progress to complete. The device can be either active or |
| * suspended after its runtime PM has been disabled. |
| * |
| * If @check_resume is set and there's a resume request pending when |
| * __pm_runtime_disable() is called and power.disable_depth is zero, the |
| * function will wake up the device before disabling its runtime PM. |
| */ |
| void __pm_runtime_disable(struct device *dev, bool check_resume) |
| { |
| spin_lock_irq(&dev->power.lock); |
| |
| if (dev->power.disable_depth > 0) { |
| dev->power.disable_depth++; |
| goto out; |
| } |
| |
| /* |
| * Wake up the device if there's a resume request pending, because that |
| * means there probably is some I/O to process and disabling runtime PM |
| * shouldn't prevent the device from processing the I/O. |
| */ |
| if (check_resume && dev->power.request_pending |
| && dev->power.request == RPM_REQ_RESUME) { |
| /* |
| * Prevent suspends and idle notifications from being carried |
| * out after we have woken up the device. |
| */ |
| pm_runtime_get_noresume(dev); |
| |
| rpm_resume(dev, 0); |
| |
| pm_runtime_put_noidle(dev); |
| } |
| |
| if (!dev->power.disable_depth++) |
| __pm_runtime_barrier(dev); |
| |
| out: |
| spin_unlock_irq(&dev->power.lock); |
| } |
| EXPORT_SYMBOL_GPL(__pm_runtime_disable); |
| |
| /** |
| * pm_runtime_enable - Enable runtime PM of a device. |
| * @dev: Device to handle. |
| */ |
| void pm_runtime_enable(struct device *dev) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&dev->power.lock, flags); |
| |
| if (dev->power.disable_depth > 0) |
| dev->power.disable_depth--; |
| else |
| dev_warn(dev, "Unbalanced %s!\n", __func__); |
| |
| WARN(!dev->power.disable_depth && |
| dev->power.runtime_status == RPM_SUSPENDED && |
| !dev->power.ignore_children && |
| atomic_read(&dev->power.child_count) > 0, |
| "Enabling runtime PM for inactive device (%s) with active children\n", |
| dev_name(dev)); |
| |
| spin_unlock_irqrestore(&dev->power.lock, flags); |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_enable); |
| |
| /** |
| * pm_runtime_forbid - Block runtime PM of a device. |
| * @dev: Device to handle. |
| * |
| * Increase the device's usage count and clear its power.runtime_auto flag, |
| * so that it cannot be suspended at run time until pm_runtime_allow() is called |
| * for it. |
| */ |
| void pm_runtime_forbid(struct device *dev) |
| { |
| spin_lock_irq(&dev->power.lock); |
| if (!dev->power.runtime_auto) |
| goto out; |
| |
| dev->power.runtime_auto = false; |
| atomic_inc(&dev->power.usage_count); |
| rpm_resume(dev, 0); |
| |
| out: |
| spin_unlock_irq(&dev->power.lock); |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_forbid); |
| |
| /** |
| * pm_runtime_allow - Unblock runtime PM of a device. |
| * @dev: Device to handle. |
| * |
| * Decrease the device's usage count and set its power.runtime_auto flag. |
| */ |
| void pm_runtime_allow(struct device *dev) |
| { |
| spin_lock_irq(&dev->power.lock); |
| if (dev->power.runtime_auto) |
| goto out; |
| |
| dev->power.runtime_auto = true; |
| if (atomic_dec_and_test(&dev->power.usage_count)) |
| rpm_idle(dev, RPM_AUTO | RPM_ASYNC); |
| |
| out: |
| spin_unlock_irq(&dev->power.lock); |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_allow); |
| |
| /** |
| * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device. |
| * @dev: Device to handle. |
| * |
| * Set the power.no_callbacks flag, which tells the PM core that this |
| * device is power-managed through its parent and has no runtime PM |
| * callbacks of its own. The runtime sysfs attributes will be removed. |
| */ |
| void pm_runtime_no_callbacks(struct device *dev) |
| { |
| spin_lock_irq(&dev->power.lock); |
| dev->power.no_callbacks = 1; |
| spin_unlock_irq(&dev->power.lock); |
| if (device_is_registered(dev)) |
| rpm_sysfs_remove(dev); |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks); |
| |
| /** |
| * pm_runtime_irq_safe - Leave interrupts disabled during callbacks. |
| * @dev: Device to handle |
| * |
| * Set the power.irq_safe flag, which tells the PM core that the |
| * ->runtime_suspend() and ->runtime_resume() callbacks for this device should |
| * always be invoked with the spinlock held and interrupts disabled. It also |
| * causes the parent's usage counter to be permanently incremented, preventing |
| * the parent from runtime suspending -- otherwise an irq-safe child might have |
| * to wait for a non-irq-safe parent. |
| */ |
| void pm_runtime_irq_safe(struct device *dev) |
| { |
| if (dev->parent) |
| pm_runtime_get_sync(dev->parent); |
| spin_lock_irq(&dev->power.lock); |
| dev->power.irq_safe = 1; |
| spin_unlock_irq(&dev->power.lock); |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_irq_safe); |
| |
| /** |
| * update_autosuspend - Handle a change to a device's autosuspend settings. |
| * @dev: Device to handle. |
| * @old_delay: The former autosuspend_delay value. |
| * @old_use: The former use_autosuspend value. |
| * |
| * Prevent runtime suspend if the new delay is negative and use_autosuspend is |
| * set; otherwise allow it. Send an idle notification if suspends are allowed. |
| * |
| * This function must be called under dev->power.lock with interrupts disabled. |
| */ |
| static void update_autosuspend(struct device *dev, int old_delay, int old_use) |
| { |
| int delay = dev->power.autosuspend_delay; |
| |
| /* Should runtime suspend be prevented now? */ |
| if (dev->power.use_autosuspend && delay < 0) { |
| |
| /* If it used to be allowed then prevent it. */ |
| if (!old_use || old_delay >= 0) { |
| atomic_inc(&dev->power.usage_count); |
| rpm_resume(dev, 0); |
| } |
| } |
| |
| /* Runtime suspend should be allowed now. */ |
| else { |
| |
| /* If it used to be prevented then allow it. */ |
| if (old_use && old_delay < 0) |
| atomic_dec(&dev->power.usage_count); |
| |
| /* Maybe we can autosuspend now. */ |
| rpm_idle(dev, RPM_AUTO); |
| } |
| } |
| |
| /** |
| * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value. |
| * @dev: Device to handle. |
| * @delay: Value of the new delay in milliseconds. |
| * |
| * Set the device's power.autosuspend_delay value. If it changes to negative |
| * and the power.use_autosuspend flag is set, prevent runtime suspends. If it |
| * changes the other way, allow runtime suspends. |
| */ |
| void pm_runtime_set_autosuspend_delay(struct device *dev, int delay) |
| { |
| int old_delay, old_use; |
| |
| spin_lock_irq(&dev->power.lock); |
| old_delay = dev->power.autosuspend_delay; |
| old_use = dev->power.use_autosuspend; |
| dev->power.autosuspend_delay = delay; |
| update_autosuspend(dev, old_delay, old_use); |
| spin_unlock_irq(&dev->power.lock); |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay); |
| |
| /** |
| * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag. |
| * @dev: Device to handle. |
| * @use: New value for use_autosuspend. |
| * |
| * Set the device's power.use_autosuspend flag, and allow or prevent runtime |
| * suspends as needed. |
| */ |
| void __pm_runtime_use_autosuspend(struct device *dev, bool use) |
| { |
| int old_delay, old_use; |
| |
| spin_lock_irq(&dev->power.lock); |
| old_delay = dev->power.autosuspend_delay; |
| old_use = dev->power.use_autosuspend; |
| dev->power.use_autosuspend = use; |
| update_autosuspend(dev, old_delay, old_use); |
| spin_unlock_irq(&dev->power.lock); |
| } |
| EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend); |
| |
| /** |
| * pm_runtime_init - Initialize runtime PM fields in given device object. |
| * @dev: Device object to initialize. |
| */ |
| void pm_runtime_init(struct device *dev) |
| { |
| dev->power.runtime_status = RPM_SUSPENDED; |
| dev->power.idle_notification = false; |
| |
| dev->power.disable_depth = 1; |
| atomic_set(&dev->power.usage_count, 0); |
| |
| dev->power.runtime_error = 0; |
| |
| atomic_set(&dev->power.child_count, 0); |
| pm_suspend_ignore_children(dev, false); |
| dev->power.runtime_auto = true; |
| |
| dev->power.request_pending = false; |
| dev->power.request = RPM_REQ_NONE; |
| dev->power.deferred_resume = false; |
| dev->power.accounting_timestamp = jiffies; |
| INIT_WORK(&dev->power.work, pm_runtime_work); |
| |
| dev->power.timer_expires = 0; |
| hrtimer_init(&dev->power.suspend_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); |
| dev->power.suspend_timer.function = pm_suspend_timer_fn; |
| |
| init_waitqueue_head(&dev->power.wait_queue); |
| } |
| |
| /** |
| * pm_runtime_reinit - Re-initialize runtime PM fields in given device object. |
| * @dev: Device object to re-initialize. |
| */ |
| void pm_runtime_reinit(struct device *dev) |
| { |
| if (!pm_runtime_enabled(dev)) { |
| if (dev->power.runtime_status == RPM_ACTIVE) |
| pm_runtime_set_suspended(dev); |
| if (dev->power.irq_safe) { |
| spin_lock_irq(&dev->power.lock); |
| dev->power.irq_safe = 0; |
| spin_unlock_irq(&dev->power.lock); |
| if (dev->parent) |
| pm_runtime_put(dev->parent); |
| } |
| } |
| } |
| |
| /** |
| * pm_runtime_remove - Prepare for removing a device from device hierarchy. |
| * @dev: Device object being removed from device hierarchy. |
| */ |
| void pm_runtime_remove(struct device *dev) |
| { |
| __pm_runtime_disable(dev, false); |
| pm_runtime_reinit(dev); |
| } |
| |
| /** |
| * pm_runtime_clean_up_links - Prepare links to consumers for driver removal. |
| * @dev: Device whose driver is going to be removed. |
| * |
| * Check links from this device to any consumers and if any of them have active |
| * runtime PM references to the device, drop the usage counter of the device |
| * (once per link). |
| * |
| * Links with the DL_FLAG_STATELESS flag set are ignored. |
| * |
| * Since the device is guaranteed to be runtime-active at the point this is |
| * called, nothing else needs to be done here. |
| * |
| * Moreover, this is called after device_links_busy() has returned 'false', so |
| * the status of each link is guaranteed to be DL_STATE_SUPPLIER_UNBIND and |
| * therefore rpm_active can't be manipulated concurrently. |
| */ |
| void pm_runtime_clean_up_links(struct device *dev) |
| { |
| struct device_link *link; |
| int idx; |
| |
| idx = device_links_read_lock(); |
| |
| list_for_each_entry_rcu(link, &dev->links.consumers, s_node) { |
| if (link->flags & DL_FLAG_STATELESS) |
| continue; |
| |
| if (link->rpm_active) { |
| pm_runtime_put_noidle(dev); |
| link->rpm_active = false; |
| } |
| } |
| |
| device_links_read_unlock(idx); |
| } |
| |
| /** |
| * pm_runtime_get_suppliers - Resume and reference-count supplier devices. |
| * @dev: Consumer device. |
| */ |
| void pm_runtime_get_suppliers(struct device *dev) |
| { |
| struct device_link *link; |
| int idx; |
| |
| idx = device_links_read_lock(); |
| |
| list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) |
| if (link->flags & DL_FLAG_PM_RUNTIME) |
| pm_runtime_get_sync(link->supplier); |
| |
| device_links_read_unlock(idx); |
| } |
| |
| /** |
| * pm_runtime_put_suppliers - Drop references to supplier devices. |
| * @dev: Consumer device. |
| */ |
| void pm_runtime_put_suppliers(struct device *dev) |
| { |
| struct device_link *link; |
| int idx; |
| |
| idx = device_links_read_lock(); |
| |
| list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) |
| if (link->flags & DL_FLAG_PM_RUNTIME) |
| pm_runtime_put(link->supplier); |
| |
| device_links_read_unlock(idx); |
| } |
| |
| void pm_runtime_new_link(struct device *dev) |
| { |
| spin_lock_irq(&dev->power.lock); |
| dev->power.links_count++; |
| spin_unlock_irq(&dev->power.lock); |
| } |
| |
| void pm_runtime_drop_link(struct device *dev) |
| { |
| rpm_put_suppliers(dev); |
| |
| spin_lock_irq(&dev->power.lock); |
| WARN_ON(dev->power.links_count == 0); |
| dev->power.links_count--; |
| spin_unlock_irq(&dev->power.lock); |
| } |
| |
| static bool pm_runtime_need_not_resume(struct device *dev) |
| { |
| return atomic_read(&dev->power.usage_count) <= 1 && |
| (atomic_read(&dev->power.child_count) == 0 || |
| dev->power.ignore_children); |
| } |
| |
| /** |
| * pm_runtime_force_suspend - Force a device into suspend state if needed. |
| * @dev: Device to suspend. |
| * |
| * Disable runtime PM so we safely can check the device's runtime PM status and |
| * if it is active, invoke its ->runtime_suspend callback to suspend it and |
| * change its runtime PM status field to RPM_SUSPENDED. Also, if the device's |
| * usage and children counters don't indicate that the device was in use before |
| * the system-wide transition under way, decrement its parent's children counter |
| * (if there is a parent). Keep runtime PM disabled to preserve the state |
| * unless we encounter errors. |
| * |
| * Typically this function may be invoked from a system suspend callback to make |
| * sure the device is put into low power state and it should only be used during |
| * system-wide PM transitions to sleep states. It assumes that the analogous |
| * pm_runtime_force_resume() will be used to resume the device. |
| */ |
| int pm_runtime_force_suspend(struct device *dev) |
| { |
| int (*callback)(struct device *); |
| int ret; |
| |
| pm_runtime_disable(dev); |
| if (pm_runtime_status_suspended(dev)) |
| return 0; |
| |
| callback = RPM_GET_CALLBACK(dev, runtime_suspend); |
| |
| ret = callback ? callback(dev) : 0; |
| if (ret) |
| goto err; |
| |
| /* |
| * If the device can stay in suspend after the system-wide transition |
| * to the working state that will follow, drop the children counter of |
| * its parent, but set its status to RPM_SUSPENDED anyway in case this |
| * function will be called again for it in the meantime. |
| */ |
| if (pm_runtime_need_not_resume(dev)) |
| pm_runtime_set_suspended(dev); |
| else |
| __update_runtime_status(dev, RPM_SUSPENDED); |
| |
| return 0; |
| |
| err: |
| pm_runtime_enable(dev); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_force_suspend); |
| |
| /** |
| * pm_runtime_force_resume - Force a device into resume state if needed. |
| * @dev: Device to resume. |
| * |
| * Prior invoking this function we expect the user to have brought the device |
| * into low power state by a call to pm_runtime_force_suspend(). Here we reverse |
| * those actions and bring the device into full power, if it is expected to be |
| * used on system resume. In the other case, we defer the resume to be managed |
| * via runtime PM. |
| * |
| * Typically this function may be invoked from a system resume callback. |
| */ |
| int pm_runtime_force_resume(struct device *dev) |
| { |
| int (*callback)(struct device *); |
| int ret = 0; |
| |
| if (!pm_runtime_status_suspended(dev) || pm_runtime_need_not_resume(dev)) |
| goto out; |
| |
| /* |
| * The value of the parent's children counter is correct already, so |
| * just update the status of the device. |
| */ |
| __update_runtime_status(dev, RPM_ACTIVE); |
| |
| callback = RPM_GET_CALLBACK(dev, runtime_resume); |
| |
| ret = callback ? callback(dev) : 0; |
| if (ret) { |
| pm_runtime_set_suspended(dev); |
| goto out; |
| } |
| |
| pm_runtime_mark_last_busy(dev); |
| out: |
| pm_runtime_enable(dev); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(pm_runtime_force_resume); |