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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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SPDX-License-Identifier: GPL-2.0/* * 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> */#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 <linux/rculist.h>#include <trace/events/rpm.h>
#include "../base.h"#include "power.h"
typedef int (*pm_callback_t)(struct device *);
static inline pm_callback_t get_callback_ptr(const void *start, size_t offset){ return *(pm_callback_t *)(start + offset);}
static pm_callback_t __rpm_get_driver_callback(struct device *dev, size_t cb_offset){ if (dev->driver && dev->driver->pm) return get_callback_ptr(dev->driver->pm, cb_offset);
return NULL;}
static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset){ const struct dev_pm_ops *ops; pm_callback_t cb = NULL;
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 = get_callback_ptr(ops, cb_offset);
if (!cb) cb = __rpm_get_driver_callback(dev, 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. */static void update_pm_runtime_accounting(struct device *dev){ u64 now, last, delta;
if (dev->power.disable_depth > 0) return;
last = dev->power.accounting_timestamp;
now = ktime_get_mono_fast_ns(); dev->power.accounting_timestamp = now;
/* * Because ktime_get_mono_fast_ns() is not monotonic during * timekeeping updates, ensure that 'now' is after the last saved * timestamp. */ if (now < last) return;
delta = now - last;
if (dev->power.runtime_status == RPM_SUSPENDED) dev->power.suspended_time += delta; else dev->power.active_time += delta;}
static void __update_runtime_status(struct device *dev, enum rpm_status status){ update_pm_runtime_accounting(dev); trace_rpm_status(dev, status); dev->power.runtime_status = status;}
static u64 rpm_get_accounted_time(struct device *dev, bool suspended){ u64 time; unsigned long flags;
spin_lock_irqsave(&dev->power.lock, flags);
update_pm_runtime_accounting(dev); time = suspended ? dev->power.suspended_time : dev->power.active_time;
spin_unlock_irqrestore(&dev->power.lock, flags);
return time;}
u64 pm_runtime_active_time(struct device *dev){ return rpm_get_accounted_time(dev, false);}
u64 pm_runtime_suspended_time(struct device *dev){ return rpm_get_accounted_time(dev, true);}EXPORT_SYMBOL_GPL(pm_runtime_suspended_time);
/** * 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_try_to_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 nanoseconds (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 expires;
if (!dev->power.use_autosuspend) return 0;
autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay); if (autosuspend_delay < 0) return 0;
expires = READ_ONCE(dev->power.last_busy); expires += (u64)autosuspend_delay * NSEC_PER_MSEC; if (expires > ktime_get_mono_fast_ns()) return expires; /* Expires in the future */
return 0;}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 involved 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)) 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_resume_latency(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, device_links_read_lock_held()) { int retval;
if (!device_link_test(link, DL_FLAG_PM_RUNTIME)) 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; } refcount_inc(&link->rpm_active); } return 0;}
/** * pm_runtime_release_supplier - Drop references to device link's supplier. * @link: Target device link. * * Drop all runtime PM references associated with @link to its supplier device. */void pm_runtime_release_supplier(struct device_link *link){ struct device *supplier = link->supplier;
/* * The additional power.usage_count check is a safety net in case * the rpm_active refcount becomes saturated, in which case * refcount_dec_not_one() would return true forever, but it is not * strictly necessary. */ while (refcount_dec_not_one(&link->rpm_active) && atomic_read(&supplier->power.usage_count) > 0) pm_runtime_put_noidle(supplier);}
static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend){ struct device_link *link;
list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, device_links_read_lock_held()) { pm_runtime_release_supplier(link); if (try_to_suspend) pm_request_idle(link->supplier); }}
static void rpm_put_suppliers(struct device *dev){ __rpm_put_suppliers(dev, true);}
static void rpm_suspend_suppliers(struct device *dev){ struct device_link *link; int idx = device_links_read_lock();
list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, device_links_read_lock_held()) pm_request_idle(link->supplier);
device_links_read_unlock(idx);}
/** * __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 = 0, 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) { rpm_put_suppliers(dev); goto fail; }
device_links_read_unlock(idx); } }
if (cb) 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();
__rpm_put_suppliers(dev, false);
fail: device_links_read_unlock(idx); }
spin_lock_irq(&dev->power.lock); }
return retval;}
/** * 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 (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); }
/* * Since -EACCES means that runtime PM is disabled for the given device, * it should not be returned by runtime PM callbacks. If it is returned * nevertheless, assume it to be a transient error and convert it to * -EAGAIN. */ if (retval == -EACCES) retval = -EAGAIN;
if (retval != -EAGAIN && retval != -EBUSY) dev->power.runtime_error = retval;
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(dev, rpmflags); retval = rpm_check_suspend_allowed(dev); if (retval < 0) ; /* Conditions are wrong. */
else if ((rpmflags & RPM_GET_PUT) && retval == 1) ; /* put() is allowed in RPM_SUSPENDED */
/* 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;
callback = RPM_GET_CALLBACK(dev, runtime_idle);
/* If no callback assume success. */ if (!callback || 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(dev, _THIS_IP_, 0); return 0; }
dev->power.idle_notification = true;
if (dev->power.irq_safe) spin_unlock(&dev->power.lock); else spin_unlock_irq(&dev->power.lock);
retval = callback(dev);
if (dev->power.irq_safe) spin_lock(&dev->power.lock); else spin_lock_irq(&dev->power.lock);
dev->power.idle_notification = false; wake_up_all(&dev->power.wait_queue);
out: trace_rpm_return_int(dev, _THIS_IP_, retval); return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);}
/** * 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(dev, rpmflags);
repeat: retval = rpm_check_suspend_allowed(dev); if (retval < 0) goto out; /* Conditions are wrong. */
/* Synchronous suspends are not allowed in the RPM_RESUMING state. */ 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 = (u64)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;
dev_pm_enable_wake_irq_complete(dev);
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; }
if (dev->power.irq_safe) goto out;
/* Maybe the parent is now able to suspend. */ if (parent && !parent->power.ignore_children) { 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); } /* Maybe the suppliers are now able to suspend. */ if (dev->power.links_count > 0) { spin_unlock_irq(&dev->power.lock);
rpm_suspend_suppliers(dev);
spin_lock_irq(&dev->power.lock); }
out: trace_rpm_return_int(dev, _THIS_IP_, retval);
return retval;
fail: dev_pm_disable_wake_irq_check(dev, true); __update_runtime_status(dev, RPM_ACTIVE); dev->power.deferred_resume = false; wake_up_all(&dev->power.wait_queue);
/* * On transient errors, 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 (!dev->power.runtime_error && (rpmflags & RPM_AUTO) && pm_runtime_autosuspend_expiration(dev) != 0) goto repeat;
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(dev, rpmflags);
repeat: if (dev->power.runtime_error) { retval = -EINVAL; } else if (dev->power.disable_depth > 0) { if (dev->power.runtime_status == RPM_ACTIVE && dev->power.last_status == RPM_ACTIVE) retval = 1; else if (rpmflags & RPM_TRANSPARENT) goto out; else 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; if (rpmflags & RPM_NOWAIT) retval = -EINPROGRESS; } 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, false); 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(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(). * @timer: hrtimer used 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 'expires' is after the current time, we've been called * too early. */ if (expires > 0 && expires <= ktime_get_mono_fast_ns()) { 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; u64 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_get_mono_fast_ns() + (u64)delay * NSEC_PER_MSEC; dev->power.timer_expires = 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);
static int rpm_drop_usage_count(struct device *dev){ int ret;
ret = atomic_sub_return(1, &dev->power.usage_count); if (ret >= 0) return ret;
/* * Because rpm_resume() does not check the usage counter, it will resume * the device even if the usage counter is 0 or negative, so it is * sufficient to increment the usage counter here to reverse the change * made above. */ atomic_inc(&dev->power.usage_count); dev_warn(dev, "Runtime PM usage count underflow!\n"); return -EINVAL;}
/** * __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 (if it becomes negative, log a * warning, increment it, and return an error). 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) { retval = rpm_drop_usage_count(dev); if (retval < 0) { return retval; } else if (retval > 0) { trace_rpm_usage(dev, rpmflags); 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 (if it becomes negative, log a * warning, increment it, and return an error). 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) { retval = rpm_drop_usage_count(dev); if (retval < 0) { return retval; } else if (retval > 0) { trace_rpm_usage(dev, rpmflags); 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_conditional - Conditionally bump up device usage counter. * @dev: Device to handle. * @ign_usage_count: Whether or not to look at the current usage counter value. * * Return -EINVAL if runtime PM is disabled for @dev. * * Otherwise, if its runtime PM status is %RPM_ACTIVE and (1) @ign_usage_count * is set, or (2) @dev is not ignoring children and its active child count is * nonzero, or (3) the runtime PM usage counter of @dev is not zero, increment * the usage counter of @dev and return 1. * * Otherwise, return 0 without changing the usage counter. * * If @ign_usage_count is %true, this function can be used to prevent suspending * the device when its runtime PM status is %RPM_ACTIVE. * * If @ign_usage_count is %false, this function can be used to prevent * suspending the device when both its runtime PM status is %RPM_ACTIVE and its * runtime PM usage counter is not zero. * * The caller is responsible for decrementing the runtime PM usage counter of * @dev after this function has returned a positive value for it. */static int pm_runtime_get_conditional(struct device *dev, bool ign_usage_count){ unsigned long flags; int retval;
spin_lock_irqsave(&dev->power.lock, flags); if (dev->power.disable_depth > 0) { retval = -EINVAL; } else if (dev->power.runtime_status != RPM_ACTIVE) { retval = 0; } else if (ign_usage_count || (!dev->power.ignore_children && atomic_read(&dev->power.child_count) > 0)) { retval = 1; atomic_inc(&dev->power.usage_count); } else { retval = atomic_inc_not_zero(&dev->power.usage_count); } trace_rpm_usage(dev, 0); spin_unlock_irqrestore(&dev->power.lock, flags);
return retval;}
/** * pm_runtime_get_if_active - Bump up runtime PM usage counter if the device is * in active state * @dev: Target device. * * Increment the runtime PM usage counter of @dev if its runtime PM status is * %RPM_ACTIVE, in which case it returns 1. If the device is in a different * state, 0 is returned. -EINVAL is returned if runtime PM is disabled for the * device, in which case also the usage_count will remain unmodified. */int pm_runtime_get_if_active(struct device *dev){ return pm_runtime_get_conditional(dev, true);}EXPORT_SYMBOL_GPL(pm_runtime_get_if_active);
/** * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter. * @dev: Target device. * * Increment the runtime PM usage counter of @dev if its runtime PM status is * %RPM_ACTIVE and its runtime PM usage counter is greater than 0 or it is not * ignoring children and its active child count is nonzero. 1 is returned in * this case. * * If @dev is in a different state or it is not in use (that is, its usage * counter is 0, or it is ignoring children, or its active child count is 0), * 0 is returned. * * -EINVAL is returned if runtime PM is disabled for the device, in which case * also the usage counter of @dev is not updated. */int pm_runtime_get_if_in_use(struct device *dev){ return pm_runtime_get_conditional(dev, false);}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. * * If @dev has any suppliers (as reflected by device links to them), and @status * is RPM_ACTIVE, they will be activated upfront and if the activation of one * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead * of the @status value) and the suppliers will be deacticated on exit. The * error returned by the failing supplier activation will be returned in that * case. */int __pm_runtime_set_status(struct device *dev, unsigned int status){ struct device *parent = dev->parent; bool notify_parent = false; unsigned long flags; int error = 0;
if (status != RPM_ACTIVE && status != RPM_SUSPENDED) return -EINVAL;
spin_lock_irqsave(&dev->power.lock, flags);
/* * Prevent PM-runtime from being enabled for the device or return an * error if it is enabled already and working. */ if (dev->power.runtime_error || dev->power.disable_depth) dev->power.disable_depth++; else error = -EAGAIN;
spin_unlock_irqrestore(&dev->power.lock, flags);
if (error) return error;
/* * If the new status is RPM_ACTIVE, the suppliers can be activated * upfront regardless of the current status, because next time * rpm_put_suppliers() runs, the rpm_active refcounts of the links * involved will be dropped down to one anyway. */ if (status == RPM_ACTIVE) { int idx = device_links_read_lock();
error = rpm_get_suppliers(dev); if (error) status = RPM_SUSPENDED;
device_links_read_unlock(idx); }
spin_lock_irqsave(&dev->power.lock, flags);
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) { status = RPM_SUSPENDED; goto out; } }
out_set: __update_runtime_status(dev, status); if (!error) dev->power.runtime_error = 0;
out: spin_unlock_irqrestore(&dev->power.lock, flags);
if (notify_parent) pm_request_idle(parent);
if (status == RPM_SUSPENDED) { int idx = device_links_read_lock();
rpm_put_suppliers(dev);
device_links_read_unlock(idx); }
pm_runtime_enable(dev);
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. */void pm_runtime_barrier(struct device *dev){ 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);
__pm_runtime_barrier(dev);
spin_unlock_irq(&dev->power.lock); pm_runtime_put_noidle(dev);}EXPORT_SYMBOL_GPL(pm_runtime_barrier);
bool pm_runtime_block_if_disabled(struct device *dev){ bool ret;
spin_lock_irq(&dev->power.lock);
ret = !pm_runtime_enabled(dev); if (ret && dev->power.last_status == RPM_INVALID) dev->power.last_status = RPM_BLOCKED;
spin_unlock_irq(&dev->power.lock);
return ret;}
void pm_runtime_unblock(struct device *dev){ spin_lock_irq(&dev->power.lock);
if (dev->power.last_status == RPM_BLOCKED) dev->power.last_status = RPM_INVALID;
spin_unlock_irq(&dev->power.lock);}
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); }
/* Update time accounting before disabling PM-runtime. */ update_pm_runtime_accounting(dev);
if (!dev->power.disable_depth++) { __pm_runtime_barrier(dev); dev->power.last_status = dev->power.runtime_status; }
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) { dev_warn(dev, "Unbalanced %s!\n", __func__); goto out; }
if (--dev->power.disable_depth > 0) goto out;
if (dev->power.last_status == RPM_BLOCKED) { dev_warn(dev, "Attempt to enable runtime PM when it is blocked\n"); dump_stack(); } dev->power.last_status = RPM_INVALID; dev->power.accounting_timestamp = ktime_get_mono_fast_ns();
if (dev->power.runtime_status == RPM_SUSPENDED && !dev->power.ignore_children && atomic_read(&dev->power.child_count) > 0) dev_warn(dev, "Enabling runtime PM for inactive device with active children\n");
out: spin_unlock_irqrestore(&dev->power.lock, flags);}EXPORT_SYMBOL_GPL(pm_runtime_enable);
static void pm_runtime_set_suspended_action(void *data){ pm_runtime_set_suspended(data);}
/** * devm_pm_runtime_set_active_enabled - set_active version of devm_pm_runtime_enable. * * @dev: Device to handle. */int devm_pm_runtime_set_active_enabled(struct device *dev){ int err;
err = pm_runtime_set_active(dev); if (err) return err;
err = devm_add_action_or_reset(dev, pm_runtime_set_suspended_action, dev); if (err) return err;
return devm_pm_runtime_enable(dev);}EXPORT_SYMBOL_GPL(devm_pm_runtime_set_active_enabled);
static void pm_runtime_disable_action(void *data){ pm_runtime_dont_use_autosuspend(data); pm_runtime_disable(data);}
/** * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable. * * NOTE: this will also handle calling pm_runtime_dont_use_autosuspend() for * you at driver exit time if needed. * * @dev: Device to handle. */int devm_pm_runtime_enable(struct device *dev){ pm_runtime_enable(dev);
return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev);}EXPORT_SYMBOL_GPL(devm_pm_runtime_enable);
static void pm_runtime_put_noidle_action(void *data){ pm_runtime_put_noidle(data);}
/** * devm_pm_runtime_get_noresume - devres-enabled version of pm_runtime_get_noresume. * * @dev: Device to handle. */int devm_pm_runtime_get_noresume(struct device *dev){ pm_runtime_get_noresume(dev);
return devm_add_action_or_reset(dev, pm_runtime_put_noidle_action, dev);}EXPORT_SYMBOL_GPL(devm_pm_runtime_get_noresume);
/** * pm_runtime_forbid - Block runtime PM of a device. * @dev: Device to handle. * * Resume @dev if already suspended and block runtime suspend of @dev in such * a way that it can be unblocked via the /sys/devices/.../power/control * interface, or otherwise by calling pm_runtime_allow(). * * Calling this function many times in a row has the same effect as calling it * once. */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. * * Unblock runtime suspend of @dev after it has been blocked by * pm_runtime_forbid() (for instance, if it has been blocked via the * /sys/devices/.../power/control interface), check if @dev can be * suspended and suspend it in that case. * * Calling this function many times in a row has the same effect as calling it * once. */void pm_runtime_allow(struct device *dev){ int ret;
spin_lock_irq(&dev->power.lock); if (dev->power.runtime_auto) goto out;
dev->power.runtime_auto = true; ret = rpm_drop_usage_count(dev); if (ret == 0) rpm_idle(dev, RPM_AUTO | RPM_ASYNC); else if (ret > 0) trace_rpm_usage(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); } else { trace_rpm_usage(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.last_status = RPM_INVALID; 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.needs_force_resume = false; INIT_WORK(&dev->power.work, pm_runtime_work);
dev->power.timer_expires = 0; hrtimer_setup(&dev->power.suspend_timer, pm_suspend_timer_fn, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
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)) return;
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); } /* * Clear power.needs_force_resume in case it has been set by * pm_runtime_force_suspend() invoked from a driver remove callback. */ dev->power.needs_force_resume = false;}
/** * 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); flush_work(&dev->power.work); pm_runtime_reinit(dev);}
/** * 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();
dev_for_each_link_to_supplier(link, dev) if (device_link_test(link, DL_FLAG_PM_RUNTIME)) { link->supplier_preactivated = true; 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, device_links_read_lock_held()) if (link->supplier_preactivated) { link->supplier_preactivated = false; 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);}
static void pm_runtime_drop_link_count(struct device *dev){ spin_lock_irq(&dev->power.lock); WARN_ON(dev->power.links_count == 0); dev->power.links_count--; spin_unlock_irq(&dev->power.lock);}
/** * pm_runtime_drop_link - Prepare for device link removal. * @link: Device link going away. * * Drop the link count of the consumer end of @link and decrement the supplier * device's runtime PM usage counter as many times as needed to drop all of the * PM runtime reference to it from the consumer. */void pm_runtime_drop_link(struct device_link *link){ if (!device_link_test(link, DL_FLAG_PM_RUNTIME)) return;
pm_runtime_drop_link_count(link->consumer); pm_runtime_release_supplier(link); pm_request_idle(link->supplier);}
static pm_callback_t get_callback(struct device *dev, size_t cb_offset){ /* * Setting power.strict_midlayer means that the middle layer * code does not want its runtime PM callbacks to be invoked via * pm_runtime_force_suspend() and pm_runtime_force_resume(), so * return a direct pointer to the driver callback in that case. */ if (dev_pm_strict_midlayer_is_set(dev)) return __rpm_get_driver_callback(dev, cb_offset);
return __rpm_get_callback(dev, cb_offset);}
#define GET_CALLBACK(dev, callback) \ get_callback(dev, offsetof(struct dev_pm_ops, callback))
/** * 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) || dev->power.needs_force_resume) return 0;
callback = GET_CALLBACK(dev, runtime_suspend);
dev_pm_enable_wake_irq_check(dev, true); ret = callback ? callback(dev) : 0; if (ret) goto err;
dev_pm_enable_wake_irq_complete(dev);
/* * 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 and the usage counters of its suppliers. Otherwise, set * power.needs_force_resume to let pm_runtime_force_resume() know that * the device needs to be taken care of and to prevent this function * from handling the device again in case the device is passed to it * once more subsequently. */ if (pm_runtime_need_not_resume(dev)) pm_runtime_set_suspended(dev); else dev->power.needs_force_resume = true;
return 0;
err: dev_pm_disable_wake_irq_check(dev, true); pm_runtime_enable(dev); return ret;}EXPORT_SYMBOL_GPL(pm_runtime_force_suspend);
#ifdef CONFIG_PM_SLEEP
/** * pm_runtime_force_resume - Force a device into resume state if needed. * @dev: Device to resume. * * This function expects that either pm_runtime_force_suspend() has put the * device into a low-power state prior to calling it, or the device had been * runtime-suspended before the preceding system-wide suspend transition and it * was left in suspend during that transition. * * The actions carried out by pm_runtime_force_suspend(), or by a runtime * suspend in general, are reversed and the device is brought back into full * power if it is expected to be used on system resume, which is the case when * its needs_force_resume flag is set or when its smart_suspend flag is set and * its runtime PM status is "active". * * In other cases, the resume is deferred 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 (!dev->power.needs_force_resume && (!dev_pm_smart_suspend(dev) || pm_runtime_status_suspended(dev))) goto out;
callback = GET_CALLBACK(dev, runtime_resume);
dev_pm_disable_wake_irq_check(dev, false); ret = callback ? callback(dev) : 0; if (ret) { pm_runtime_set_suspended(dev); dev_pm_enable_wake_irq_check(dev, false); goto out; }
pm_runtime_mark_last_busy(dev);
out: /* * The smart_suspend flag can be cleared here because it is not going * to be necessary until the next system-wide suspend transition that * will update it again. */ dev->power.smart_suspend = false; /* * Also clear needs_force_resume to make this function skip devices that * have been seen by it once. */ dev->power.needs_force_resume = false;
pm_runtime_enable(dev); return ret;}EXPORT_SYMBOL_GPL(pm_runtime_force_resume);
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);}
#endif /* CONFIG_PM_SLEEP */