diff options
Diffstat (limited to 'drivers/base/power/main.c')
| -rw-r--r-- | drivers/base/power/main.c | 2015 |
1 files changed, 2015 insertions, 0 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c new file mode 100644 index 000000000..1dbaaddf5 --- /dev/null +++ b/drivers/base/power/main.c @@ -0,0 +1,2015 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * drivers/base/power/main.c - Where the driver meets power management. + * + * Copyright (c) 2003 Patrick Mochel + * Copyright (c) 2003 Open Source Development Lab + * + * The driver model core calls device_pm_add() when a device is registered. + * This will initialize the embedded device_pm_info object in the device + * and add it to the list of power-controlled devices. sysfs entries for + * controlling device power management will also be added. + * + * A separate list is used for keeping track of power info, because the power + * domain dependencies may differ from the ancestral dependencies that the + * subsystem list maintains. + */ + +#define pr_fmt(fmt) "PM: " fmt + +#include <linux/device.h> +#include <linux/export.h> +#include <linux/mutex.h> +#include <linux/pm.h> +#include <linux/pm_runtime.h> +#include <linux/pm-trace.h> +#include <linux/pm_wakeirq.h> +#include <linux/interrupt.h> +#include <linux/sched.h> +#include <linux/sched/debug.h> +#include <linux/async.h> +#include <linux/suspend.h> +#include <trace/events/power.h> +#include <linux/cpufreq.h> +#include <linux/cpuidle.h> +#include <linux/devfreq.h> +#include <linux/timer.h> + +#include "../base.h" +#include "power.h" + +typedef int (*pm_callback_t)(struct device *); + +#define list_for_each_entry_rcu_locked(pos, head, member) \ + list_for_each_entry_rcu(pos, head, member, \ + device_links_read_lock_held()) + +/* + * The entries in the dpm_list list are in a depth first order, simply + * because children are guaranteed to be discovered after parents, and + * are inserted at the back of the list on discovery. + * + * Since device_pm_add() may be called with a device lock held, + * we must never try to acquire a device lock while holding + * dpm_list_mutex. + */ + +LIST_HEAD(dpm_list); +static LIST_HEAD(dpm_prepared_list); +static LIST_HEAD(dpm_suspended_list); +static LIST_HEAD(dpm_late_early_list); +static LIST_HEAD(dpm_noirq_list); + +struct suspend_stats suspend_stats; +static DEFINE_MUTEX(dpm_list_mtx); +static pm_message_t pm_transition; + +static int async_error; + +static const char *pm_verb(int event) +{ + switch (event) { + case PM_EVENT_SUSPEND: + return "suspend"; + case PM_EVENT_RESUME: + return "resume"; + case PM_EVENT_FREEZE: + return "freeze"; + case PM_EVENT_QUIESCE: + return "quiesce"; + case PM_EVENT_HIBERNATE: + return "hibernate"; + case PM_EVENT_THAW: + return "thaw"; + case PM_EVENT_RESTORE: + return "restore"; + case PM_EVENT_RECOVER: + return "recover"; + default: + return "(unknown PM event)"; + } +} + +/** + * device_pm_sleep_init - Initialize system suspend-related device fields. + * @dev: Device object being initialized. + */ +void device_pm_sleep_init(struct device *dev) +{ + dev->power.is_prepared = false; + dev->power.is_suspended = false; + dev->power.is_noirq_suspended = false; + dev->power.is_late_suspended = false; + init_completion(&dev->power.completion); + complete_all(&dev->power.completion); + dev->power.wakeup = NULL; + INIT_LIST_HEAD(&dev->power.entry); +} + +/** + * device_pm_lock - Lock the list of active devices used by the PM core. + */ +void device_pm_lock(void) +{ + mutex_lock(&dpm_list_mtx); +} + +/** + * device_pm_unlock - Unlock the list of active devices used by the PM core. + */ +void device_pm_unlock(void) +{ + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_pm_add - Add a device to the PM core's list of active devices. + * @dev: Device to add to the list. + */ +void device_pm_add(struct device *dev) +{ + /* Skip PM setup/initialization. */ + if (device_pm_not_required(dev)) + return; + + pr_debug("Adding info for %s:%s\n", + dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); + device_pm_check_callbacks(dev); + mutex_lock(&dpm_list_mtx); + if (dev->parent && dev->parent->power.is_prepared) + dev_warn(dev, "parent %s should not be sleeping\n", + dev_name(dev->parent)); + list_add_tail(&dev->power.entry, &dpm_list); + dev->power.in_dpm_list = true; + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_pm_remove - Remove a device from the PM core's list of active devices. + * @dev: Device to be removed from the list. + */ +void device_pm_remove(struct device *dev) +{ + if (device_pm_not_required(dev)) + return; + + pr_debug("Removing info for %s:%s\n", + dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); + complete_all(&dev->power.completion); + mutex_lock(&dpm_list_mtx); + list_del_init(&dev->power.entry); + dev->power.in_dpm_list = false; + mutex_unlock(&dpm_list_mtx); + device_wakeup_disable(dev); + pm_runtime_remove(dev); + device_pm_check_callbacks(dev); +} + +/** + * device_pm_move_before - Move device in the PM core's list of active devices. + * @deva: Device to move in dpm_list. + * @devb: Device @deva should come before. + */ +void device_pm_move_before(struct device *deva, struct device *devb) +{ + pr_debug("Moving %s:%s before %s:%s\n", + deva->bus ? deva->bus->name : "No Bus", dev_name(deva), + devb->bus ? devb->bus->name : "No Bus", dev_name(devb)); + /* Delete deva from dpm_list and reinsert before devb. */ + list_move_tail(&deva->power.entry, &devb->power.entry); +} + +/** + * device_pm_move_after - Move device in the PM core's list of active devices. + * @deva: Device to move in dpm_list. + * @devb: Device @deva should come after. + */ +void device_pm_move_after(struct device *deva, struct device *devb) +{ + pr_debug("Moving %s:%s after %s:%s\n", + deva->bus ? deva->bus->name : "No Bus", dev_name(deva), + devb->bus ? devb->bus->name : "No Bus", dev_name(devb)); + /* Delete deva from dpm_list and reinsert after devb. */ + list_move(&deva->power.entry, &devb->power.entry); +} + +/** + * device_pm_move_last - Move device to end of the PM core's list of devices. + * @dev: Device to move in dpm_list. + */ +void device_pm_move_last(struct device *dev) +{ + pr_debug("Moving %s:%s to end of list\n", + dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); + list_move_tail(&dev->power.entry, &dpm_list); +} + +static ktime_t initcall_debug_start(struct device *dev, void *cb) +{ + if (!pm_print_times_enabled) + return 0; + + dev_info(dev, "calling %pS @ %i, parent: %s\n", cb, + task_pid_nr(current), + dev->parent ? dev_name(dev->parent) : "none"); + return ktime_get(); +} + +static void initcall_debug_report(struct device *dev, ktime_t calltime, + void *cb, int error) +{ + ktime_t rettime; + s64 nsecs; + + if (!pm_print_times_enabled) + return; + + rettime = ktime_get(); + nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime)); + + dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error, + (unsigned long long)nsecs >> 10); +} + +/** + * dpm_wait - Wait for a PM operation to complete. + * @dev: Device to wait for. + * @async: If unset, wait only if the device's power.async_suspend flag is set. + */ +static void dpm_wait(struct device *dev, bool async) +{ + if (!dev) + return; + + if (async || (pm_async_enabled && dev->power.async_suspend)) + wait_for_completion(&dev->power.completion); +} + +static int dpm_wait_fn(struct device *dev, void *async_ptr) +{ + dpm_wait(dev, *((bool *)async_ptr)); + return 0; +} + +static void dpm_wait_for_children(struct device *dev, bool async) +{ + device_for_each_child(dev, &async, dpm_wait_fn); +} + +static void dpm_wait_for_suppliers(struct device *dev, bool async) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + /* + * If the supplier goes away right after we've checked the link to it, + * we'll wait for its completion to change the state, but that's fine, + * because the only things that will block as a result are the SRCU + * callbacks freeing the link objects for the links in the list we're + * walking. + */ + list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) + if (READ_ONCE(link->status) != DL_STATE_DORMANT) + dpm_wait(link->supplier, async); + + device_links_read_unlock(idx); +} + +static bool dpm_wait_for_superior(struct device *dev, bool async) +{ + struct device *parent; + + /* + * If the device is resumed asynchronously and the parent's callback + * deletes both the device and the parent itself, the parent object may + * be freed while this function is running, so avoid that by reference + * counting the parent once more unless the device has been deleted + * already (in which case return right away). + */ + mutex_lock(&dpm_list_mtx); + + if (!device_pm_initialized(dev)) { + mutex_unlock(&dpm_list_mtx); + return false; + } + + parent = get_device(dev->parent); + + mutex_unlock(&dpm_list_mtx); + + dpm_wait(parent, async); + put_device(parent); + + dpm_wait_for_suppliers(dev, async); + + /* + * If the parent's callback has deleted the device, attempting to resume + * it would be invalid, so avoid doing that then. + */ + return device_pm_initialized(dev); +} + +static void dpm_wait_for_consumers(struct device *dev, bool async) +{ + struct device_link *link; + int idx; + + idx = device_links_read_lock(); + + /* + * The status of a device link can only be changed from "dormant" by a + * probe, but that cannot happen during system suspend/resume. In + * theory it can change to "dormant" at that time, but then it is + * reasonable to wait for the target device anyway (eg. if it goes + * away, it's better to wait for it to go away completely and then + * continue instead of trying to continue in parallel with its + * unregistration). + */ + list_for_each_entry_rcu_locked(link, &dev->links.consumers, s_node) + if (READ_ONCE(link->status) != DL_STATE_DORMANT) + dpm_wait(link->consumer, async); + + device_links_read_unlock(idx); +} + +static void dpm_wait_for_subordinate(struct device *dev, bool async) +{ + dpm_wait_for_children(dev, async); + dpm_wait_for_consumers(dev, async); +} + +/** + * pm_op - Return the PM operation appropriate for given PM event. + * @ops: PM operations to choose from. + * @state: PM transition of the system being carried out. + */ +static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state) +{ + switch (state.event) { +#ifdef CONFIG_SUSPEND + case PM_EVENT_SUSPEND: + return ops->suspend; + case PM_EVENT_RESUME: + return ops->resume; +#endif /* CONFIG_SUSPEND */ +#ifdef CONFIG_HIBERNATE_CALLBACKS + case PM_EVENT_FREEZE: + case PM_EVENT_QUIESCE: + return ops->freeze; + case PM_EVENT_HIBERNATE: + return ops->poweroff; + case PM_EVENT_THAW: + case PM_EVENT_RECOVER: + return ops->thaw; + case PM_EVENT_RESTORE: + return ops->restore; +#endif /* CONFIG_HIBERNATE_CALLBACKS */ + } + + return NULL; +} + +/** + * pm_late_early_op - Return the PM operation appropriate for given PM event. + * @ops: PM operations to choose from. + * @state: PM transition of the system being carried out. + * + * Runtime PM is disabled for @dev while this function is being executed. + */ +static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops, + pm_message_t state) +{ + switch (state.event) { +#ifdef CONFIG_SUSPEND + case PM_EVENT_SUSPEND: + return ops->suspend_late; + case PM_EVENT_RESUME: + return ops->resume_early; +#endif /* CONFIG_SUSPEND */ +#ifdef CONFIG_HIBERNATE_CALLBACKS + case PM_EVENT_FREEZE: + case PM_EVENT_QUIESCE: + return ops->freeze_late; + case PM_EVENT_HIBERNATE: + return ops->poweroff_late; + case PM_EVENT_THAW: + case PM_EVENT_RECOVER: + return ops->thaw_early; + case PM_EVENT_RESTORE: + return ops->restore_early; +#endif /* CONFIG_HIBERNATE_CALLBACKS */ + } + + return NULL; +} + +/** + * pm_noirq_op - Return the PM operation appropriate for given PM event. + * @ops: PM operations to choose from. + * @state: PM transition of the system being carried out. + * + * The driver of @dev will not receive interrupts while this function is being + * executed. + */ +static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state) +{ + switch (state.event) { +#ifdef CONFIG_SUSPEND + case PM_EVENT_SUSPEND: + return ops->suspend_noirq; + case PM_EVENT_RESUME: + return ops->resume_noirq; +#endif /* CONFIG_SUSPEND */ +#ifdef CONFIG_HIBERNATE_CALLBACKS + case PM_EVENT_FREEZE: + case PM_EVENT_QUIESCE: + return ops->freeze_noirq; + case PM_EVENT_HIBERNATE: + return ops->poweroff_noirq; + case PM_EVENT_THAW: + case PM_EVENT_RECOVER: + return ops->thaw_noirq; + case PM_EVENT_RESTORE: + return ops->restore_noirq; +#endif /* CONFIG_HIBERNATE_CALLBACKS */ + } + + return NULL; +} + +static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info) +{ + dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event), + ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ? + ", may wakeup" : ""); +} + +static void pm_dev_err(struct device *dev, pm_message_t state, const char *info, + int error) +{ + pr_err("Device %s failed to %s%s: error %d\n", + dev_name(dev), pm_verb(state.event), info, error); +} + +static void dpm_show_time(ktime_t starttime, pm_message_t state, int error, + const char *info) +{ + ktime_t calltime; + u64 usecs64; + int usecs; + + calltime = ktime_get(); + usecs64 = ktime_to_ns(ktime_sub(calltime, starttime)); + do_div(usecs64, NSEC_PER_USEC); + usecs = usecs64; + if (usecs == 0) + usecs = 1; + + pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n", + info ?: "", info ? " " : "", pm_verb(state.event), + error ? "aborted" : "complete", + usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC); +} + +static int dpm_run_callback(pm_callback_t cb, struct device *dev, + pm_message_t state, const char *info) +{ + ktime_t calltime; + int error; + + if (!cb) + return 0; + + calltime = initcall_debug_start(dev, cb); + + pm_dev_dbg(dev, state, info); + trace_device_pm_callback_start(dev, info, state.event); + error = cb(dev); + trace_device_pm_callback_end(dev, error); + suspend_report_result(cb, error); + + initcall_debug_report(dev, calltime, cb, error); + + return error; +} + +#ifdef CONFIG_DPM_WATCHDOG +struct dpm_watchdog { + struct device *dev; + struct task_struct *tsk; + struct timer_list timer; +}; + +#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \ + struct dpm_watchdog wd + +/** + * dpm_watchdog_handler - Driver suspend / resume watchdog handler. + * @t: The timer that PM watchdog depends on. + * + * Called when a driver has timed out suspending or resuming. + * There's not much we can do here to recover so panic() to + * capture a crash-dump in pstore. + */ +static void dpm_watchdog_handler(struct timer_list *t) +{ + struct dpm_watchdog *wd = from_timer(wd, t, timer); + + dev_emerg(wd->dev, "**** DPM device timeout ****\n"); + show_stack(wd->tsk, NULL, KERN_EMERG); + panic("%s %s: unrecoverable failure\n", + dev_driver_string(wd->dev), dev_name(wd->dev)); +} + +/** + * dpm_watchdog_set - Enable pm watchdog for given device. + * @wd: Watchdog. Must be allocated on the stack. + * @dev: Device to handle. + */ +static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev) +{ + struct timer_list *timer = &wd->timer; + + wd->dev = dev; + wd->tsk = current; + + timer_setup_on_stack(timer, dpm_watchdog_handler, 0); + /* use same timeout value for both suspend and resume */ + timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT; + add_timer(timer); +} + +/** + * dpm_watchdog_clear - Disable suspend/resume watchdog. + * @wd: Watchdog to disable. + */ +static void dpm_watchdog_clear(struct dpm_watchdog *wd) +{ + struct timer_list *timer = &wd->timer; + + del_timer_sync(timer); + destroy_timer_on_stack(timer); +} +#else +#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) +#define dpm_watchdog_set(x, y) +#define dpm_watchdog_clear(x) +#endif + +/*------------------------- Resume routines -------------------------*/ + +/** + * dev_pm_skip_resume - System-wide device resume optimization check. + * @dev: Target device. + * + * Return: + * - %false if the transition under way is RESTORE. + * - Return value of dev_pm_skip_suspend() if the transition under way is THAW. + * - The logical negation of %power.must_resume otherwise (that is, when the + * transition under way is RESUME). + */ +bool dev_pm_skip_resume(struct device *dev) +{ + if (pm_transition.event == PM_EVENT_RESTORE) + return false; + + if (pm_transition.event == PM_EVENT_THAW) + return dev_pm_skip_suspend(dev); + + return !dev->power.must_resume; +} + +/** + * device_resume_noirq - Execute a "noirq resume" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * @async: If true, the device is being resumed asynchronously. + * + * The driver of @dev will not receive interrupts while this function is being + * executed. + */ +static int device_resume_noirq(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + const char *info = NULL; + bool skip_resume; + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + if (dev->power.syscore || dev->power.direct_complete) + goto Out; + + if (!dev->power.is_noirq_suspended) + goto Out; + + if (!dpm_wait_for_superior(dev, async)) + goto Out; + + skip_resume = dev_pm_skip_resume(dev); + /* + * If the driver callback is skipped below or by the middle layer + * callback and device_resume_early() also skips the driver callback for + * this device later, it needs to appear as "suspended" to PM-runtime, + * so change its status accordingly. + * + * Otherwise, the device is going to be resumed, so set its PM-runtime + * status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set + * to avoid confusing drivers that don't use it. + */ + if (skip_resume) + pm_runtime_set_suspended(dev); + else if (dev_pm_skip_suspend(dev)) + pm_runtime_set_active(dev); + + if (dev->pm_domain) { + info = "noirq power domain "; + callback = pm_noirq_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "noirq type "; + callback = pm_noirq_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "noirq class "; + callback = pm_noirq_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "noirq bus "; + callback = pm_noirq_op(dev->bus->pm, state); + } + if (callback) + goto Run; + + if (skip_resume) + goto Skip; + + if (dev->driver && dev->driver->pm) { + info = "noirq driver "; + callback = pm_noirq_op(dev->driver->pm, state); + } + +Run: + error = dpm_run_callback(callback, dev, state, info); + +Skip: + dev->power.is_noirq_suspended = false; + +Out: + complete_all(&dev->power.completion); + TRACE_RESUME(error); + return error; +} + +static bool is_async(struct device *dev) +{ + return dev->power.async_suspend && pm_async_enabled + && !pm_trace_is_enabled(); +} + +static bool dpm_async_fn(struct device *dev, async_func_t func) +{ + reinit_completion(&dev->power.completion); + + if (is_async(dev)) { + get_device(dev); + async_schedule_dev(func, dev); + return true; + } + + return false; +} + +static void async_resume_noirq(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = device_resume_noirq(dev, pm_transition, true); + if (error) + pm_dev_err(dev, pm_transition, " async", error); + + put_device(dev); +} + +static void dpm_noirq_resume_devices(pm_message_t state) +{ + struct device *dev; + ktime_t starttime = ktime_get(); + + trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true); + mutex_lock(&dpm_list_mtx); + pm_transition = state; + + /* + * Advanced the async threads upfront, + * in case the starting of async threads is + * delayed by non-async resuming devices. + */ + list_for_each_entry(dev, &dpm_noirq_list, power.entry) + dpm_async_fn(dev, async_resume_noirq); + + while (!list_empty(&dpm_noirq_list)) { + dev = to_device(dpm_noirq_list.next); + get_device(dev); + list_move_tail(&dev->power.entry, &dpm_late_early_list); + mutex_unlock(&dpm_list_mtx); + + if (!is_async(dev)) { + int error; + + error = device_resume_noirq(dev, state, false); + if (error) { + suspend_stats.failed_resume_noirq++; + dpm_save_failed_step(SUSPEND_RESUME_NOIRQ); + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, state, " noirq", error); + } + } + + mutex_lock(&dpm_list_mtx); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + dpm_show_time(starttime, state, 0, "noirq"); + trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false); +} + +/** + * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices. + * @state: PM transition of the system being carried out. + * + * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and + * allow device drivers' interrupt handlers to be called. + */ +void dpm_resume_noirq(pm_message_t state) +{ + dpm_noirq_resume_devices(state); + + resume_device_irqs(); + device_wakeup_disarm_wake_irqs(); + + cpuidle_resume(); +} + +/** + * device_resume_early - Execute an "early resume" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * @async: If true, the device is being resumed asynchronously. + * + * Runtime PM is disabled for @dev while this function is being executed. + */ +static int device_resume_early(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + const char *info = NULL; + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + if (dev->power.syscore || dev->power.direct_complete) + goto Out; + + if (!dev->power.is_late_suspended) + goto Out; + + if (!dpm_wait_for_superior(dev, async)) + goto Out; + + if (dev->pm_domain) { + info = "early power domain "; + callback = pm_late_early_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "early type "; + callback = pm_late_early_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "early class "; + callback = pm_late_early_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "early bus "; + callback = pm_late_early_op(dev->bus->pm, state); + } + if (callback) + goto Run; + + if (dev_pm_skip_resume(dev)) + goto Skip; + + if (dev->driver && dev->driver->pm) { + info = "early driver "; + callback = pm_late_early_op(dev->driver->pm, state); + } + +Run: + error = dpm_run_callback(callback, dev, state, info); + +Skip: + dev->power.is_late_suspended = false; + +Out: + TRACE_RESUME(error); + + pm_runtime_enable(dev); + complete_all(&dev->power.completion); + return error; +} + +static void async_resume_early(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = device_resume_early(dev, pm_transition, true); + if (error) + pm_dev_err(dev, pm_transition, " async", error); + + put_device(dev); +} + +/** + * dpm_resume_early - Execute "early resume" callbacks for all devices. + * @state: PM transition of the system being carried out. + */ +void dpm_resume_early(pm_message_t state) +{ + struct device *dev; + ktime_t starttime = ktime_get(); + + trace_suspend_resume(TPS("dpm_resume_early"), state.event, true); + mutex_lock(&dpm_list_mtx); + pm_transition = state; + + /* + * Advanced the async threads upfront, + * in case the starting of async threads is + * delayed by non-async resuming devices. + */ + list_for_each_entry(dev, &dpm_late_early_list, power.entry) + dpm_async_fn(dev, async_resume_early); + + while (!list_empty(&dpm_late_early_list)) { + dev = to_device(dpm_late_early_list.next); + get_device(dev); + list_move_tail(&dev->power.entry, &dpm_suspended_list); + mutex_unlock(&dpm_list_mtx); + + if (!is_async(dev)) { + int error; + + error = device_resume_early(dev, state, false); + if (error) { + suspend_stats.failed_resume_early++; + dpm_save_failed_step(SUSPEND_RESUME_EARLY); + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, state, " early", error); + } + } + mutex_lock(&dpm_list_mtx); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + dpm_show_time(starttime, state, 0, "early"); + trace_suspend_resume(TPS("dpm_resume_early"), state.event, false); +} + +/** + * dpm_resume_start - Execute "noirq" and "early" device callbacks. + * @state: PM transition of the system being carried out. + */ +void dpm_resume_start(pm_message_t state) +{ + dpm_resume_noirq(state); + dpm_resume_early(state); +} +EXPORT_SYMBOL_GPL(dpm_resume_start); + +/** + * device_resume - Execute "resume" callbacks for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * @async: If true, the device is being resumed asynchronously. + */ +static int device_resume(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + const char *info = NULL; + int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + if (dev->power.syscore) + goto Complete; + + if (dev->power.direct_complete) { + /* Match the pm_runtime_disable() in __device_suspend(). */ + pm_runtime_enable(dev); + goto Complete; + } + + if (!dpm_wait_for_superior(dev, async)) + goto Complete; + + dpm_watchdog_set(&wd, dev); + device_lock(dev); + + /* + * This is a fib. But we'll allow new children to be added below + * a resumed device, even if the device hasn't been completed yet. + */ + dev->power.is_prepared = false; + + if (!dev->power.is_suspended) + goto Unlock; + + if (dev->pm_domain) { + info = "power domain "; + callback = pm_op(&dev->pm_domain->ops, state); + goto Driver; + } + + if (dev->type && dev->type->pm) { + info = "type "; + callback = pm_op(dev->type->pm, state); + goto Driver; + } + + if (dev->class && dev->class->pm) { + info = "class "; + callback = pm_op(dev->class->pm, state); + goto Driver; + } + + if (dev->bus) { + if (dev->bus->pm) { + info = "bus "; + callback = pm_op(dev->bus->pm, state); + } else if (dev->bus->resume) { + info = "legacy bus "; + callback = dev->bus->resume; + goto End; + } + } + + Driver: + if (!callback && dev->driver && dev->driver->pm) { + info = "driver "; + callback = pm_op(dev->driver->pm, state); + } + + End: + error = dpm_run_callback(callback, dev, state, info); + dev->power.is_suspended = false; + + Unlock: + device_unlock(dev); + dpm_watchdog_clear(&wd); + + Complete: + complete_all(&dev->power.completion); + + TRACE_RESUME(error); + + return error; +} + +static void async_resume(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = device_resume(dev, pm_transition, true); + if (error) + pm_dev_err(dev, pm_transition, " async", error); + put_device(dev); +} + +/** + * dpm_resume - Execute "resume" callbacks for non-sysdev devices. + * @state: PM transition of the system being carried out. + * + * Execute the appropriate "resume" callback for all devices whose status + * indicates that they are suspended. + */ +void dpm_resume(pm_message_t state) +{ + struct device *dev; + ktime_t starttime = ktime_get(); + + trace_suspend_resume(TPS("dpm_resume"), state.event, true); + might_sleep(); + + mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; + + list_for_each_entry(dev, &dpm_suspended_list, power.entry) + dpm_async_fn(dev, async_resume); + + while (!list_empty(&dpm_suspended_list)) { + dev = to_device(dpm_suspended_list.next); + get_device(dev); + if (!is_async(dev)) { + int error; + + mutex_unlock(&dpm_list_mtx); + + error = device_resume(dev, state, false); + if (error) { + suspend_stats.failed_resume++; + dpm_save_failed_step(SUSPEND_RESUME); + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, state, "", error); + } + + mutex_lock(&dpm_list_mtx); + } + if (!list_empty(&dev->power.entry)) + list_move_tail(&dev->power.entry, &dpm_prepared_list); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + dpm_show_time(starttime, state, 0, NULL); + + cpufreq_resume(); + devfreq_resume(); + trace_suspend_resume(TPS("dpm_resume"), state.event, false); +} + +/** + * device_complete - Complete a PM transition for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + */ +static void device_complete(struct device *dev, pm_message_t state) +{ + void (*callback)(struct device *) = NULL; + const char *info = NULL; + + if (dev->power.syscore) + goto out; + + device_lock(dev); + + if (dev->pm_domain) { + info = "completing power domain "; + callback = dev->pm_domain->ops.complete; + } else if (dev->type && dev->type->pm) { + info = "completing type "; + callback = dev->type->pm->complete; + } else if (dev->class && dev->class->pm) { + info = "completing class "; + callback = dev->class->pm->complete; + } else if (dev->bus && dev->bus->pm) { + info = "completing bus "; + callback = dev->bus->pm->complete; + } + + if (!callback && dev->driver && dev->driver->pm) { + info = "completing driver "; + callback = dev->driver->pm->complete; + } + + if (callback) { + pm_dev_dbg(dev, state, info); + callback(dev); + } + + device_unlock(dev); + +out: + pm_runtime_put(dev); +} + +/** + * dpm_complete - Complete a PM transition for all non-sysdev devices. + * @state: PM transition of the system being carried out. + * + * Execute the ->complete() callbacks for all devices whose PM status is not + * DPM_ON (this allows new devices to be registered). + */ +void dpm_complete(pm_message_t state) +{ + struct list_head list; + + trace_suspend_resume(TPS("dpm_complete"), state.event, true); + might_sleep(); + + INIT_LIST_HEAD(&list); + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_prepared_list)) { + struct device *dev = to_device(dpm_prepared_list.prev); + + get_device(dev); + dev->power.is_prepared = false; + list_move(&dev->power.entry, &list); + mutex_unlock(&dpm_list_mtx); + + trace_device_pm_callback_start(dev, "", state.event); + device_complete(dev, state); + trace_device_pm_callback_end(dev, 0); + + mutex_lock(&dpm_list_mtx); + put_device(dev); + } + list_splice(&list, &dpm_list); + mutex_unlock(&dpm_list_mtx); + + /* Allow device probing and trigger re-probing of deferred devices */ + device_unblock_probing(); + trace_suspend_resume(TPS("dpm_complete"), state.event, false); +} + +/** + * dpm_resume_end - Execute "resume" callbacks and complete system transition. + * @state: PM transition of the system being carried out. + * + * Execute "resume" callbacks for all devices and complete the PM transition of + * the system. + */ +void dpm_resume_end(pm_message_t state) +{ + dpm_resume(state); + dpm_complete(state); +} +EXPORT_SYMBOL_GPL(dpm_resume_end); + + +/*------------------------- Suspend routines -------------------------*/ + +/** + * resume_event - Return a "resume" message for given "suspend" sleep state. + * @sleep_state: PM message representing a sleep state. + * + * Return a PM message representing the resume event corresponding to given + * sleep state. + */ +static pm_message_t resume_event(pm_message_t sleep_state) +{ + switch (sleep_state.event) { + case PM_EVENT_SUSPEND: + return PMSG_RESUME; + case PM_EVENT_FREEZE: + case PM_EVENT_QUIESCE: + return PMSG_RECOVER; + case PM_EVENT_HIBERNATE: + return PMSG_RESTORE; + } + return PMSG_ON; +} + +static void dpm_superior_set_must_resume(struct device *dev) +{ + struct device_link *link; + int idx; + + if (dev->parent) + dev->parent->power.must_resume = true; + + idx = device_links_read_lock(); + + list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) + link->supplier->power.must_resume = true; + + device_links_read_unlock(idx); +} + +/** + * __device_suspend_noirq - Execute a "noirq suspend" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * @async: If true, the device is being suspended asynchronously. + * + * The driver of @dev will not receive interrupts while this function is being + * executed. + */ +static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + const char *info = NULL; + int error = 0; + + TRACE_DEVICE(dev); + TRACE_SUSPEND(0); + + dpm_wait_for_subordinate(dev, async); + + if (async_error) + goto Complete; + + if (dev->power.syscore || dev->power.direct_complete) + goto Complete; + + if (dev->pm_domain) { + info = "noirq power domain "; + callback = pm_noirq_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "noirq type "; + callback = pm_noirq_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "noirq class "; + callback = pm_noirq_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "noirq bus "; + callback = pm_noirq_op(dev->bus->pm, state); + } + if (callback) + goto Run; + + if (dev_pm_skip_suspend(dev)) + goto Skip; + + if (dev->driver && dev->driver->pm) { + info = "noirq driver "; + callback = pm_noirq_op(dev->driver->pm, state); + } + +Run: + error = dpm_run_callback(callback, dev, state, info); + if (error) { + async_error = error; + goto Complete; + } + +Skip: + dev->power.is_noirq_suspended = true; + + /* + * Skipping the resume of devices that were in use right before the + * system suspend (as indicated by their PM-runtime usage counters) + * would be suboptimal. Also resume them if doing that is not allowed + * to be skipped. + */ + if (atomic_read(&dev->power.usage_count) > 1 || + !(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME) && + dev->power.may_skip_resume)) + dev->power.must_resume = true; + + if (dev->power.must_resume) + dpm_superior_set_must_resume(dev); + +Complete: + complete_all(&dev->power.completion); + TRACE_SUSPEND(error); + return error; +} + +static void async_suspend_noirq(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = __device_suspend_noirq(dev, pm_transition, true); + if (error) { + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, pm_transition, " async", error); + } + + put_device(dev); +} + +static int device_suspend_noirq(struct device *dev) +{ + if (dpm_async_fn(dev, async_suspend_noirq)) + return 0; + + return __device_suspend_noirq(dev, pm_transition, false); +} + +static int dpm_noirq_suspend_devices(pm_message_t state) +{ + ktime_t starttime = ktime_get(); + int error = 0; + + trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true); + mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; + + while (!list_empty(&dpm_late_early_list)) { + struct device *dev = to_device(dpm_late_early_list.prev); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = device_suspend_noirq(dev); + + mutex_lock(&dpm_list_mtx); + if (error) { + pm_dev_err(dev, state, " noirq", error); + dpm_save_failed_dev(dev_name(dev)); + put_device(dev); + break; + } + if (!list_empty(&dev->power.entry)) + list_move(&dev->power.entry, &dpm_noirq_list); + put_device(dev); + + if (async_error) + break; + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + if (!error) + error = async_error; + + if (error) { + suspend_stats.failed_suspend_noirq++; + dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ); + } + dpm_show_time(starttime, state, error, "noirq"); + trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false); + return error; +} + +/** + * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices. + * @state: PM transition of the system being carried out. + * + * Prevent device drivers' interrupt handlers from being called and invoke + * "noirq" suspend callbacks for all non-sysdev devices. + */ +int dpm_suspend_noirq(pm_message_t state) +{ + int ret; + + cpuidle_pause(); + + device_wakeup_arm_wake_irqs(); + suspend_device_irqs(); + + ret = dpm_noirq_suspend_devices(state); + if (ret) + dpm_resume_noirq(resume_event(state)); + + return ret; +} + +static void dpm_propagate_wakeup_to_parent(struct device *dev) +{ + struct device *parent = dev->parent; + + if (!parent) + return; + + spin_lock_irq(&parent->power.lock); + + if (dev->power.wakeup_path && !parent->power.ignore_children) + parent->power.wakeup_path = true; + + spin_unlock_irq(&parent->power.lock); +} + +/** + * __device_suspend_late - Execute a "late suspend" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * @async: If true, the device is being suspended asynchronously. + * + * Runtime PM is disabled for @dev while this function is being executed. + */ +static int __device_suspend_late(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + const char *info = NULL; + int error = 0; + + TRACE_DEVICE(dev); + TRACE_SUSPEND(0); + + __pm_runtime_disable(dev, false); + + dpm_wait_for_subordinate(dev, async); + + if (async_error) + goto Complete; + + if (pm_wakeup_pending()) { + async_error = -EBUSY; + goto Complete; + } + + if (dev->power.syscore || dev->power.direct_complete) + goto Complete; + + if (dev->pm_domain) { + info = "late power domain "; + callback = pm_late_early_op(&dev->pm_domain->ops, state); + } else if (dev->type && dev->type->pm) { + info = "late type "; + callback = pm_late_early_op(dev->type->pm, state); + } else if (dev->class && dev->class->pm) { + info = "late class "; + callback = pm_late_early_op(dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + info = "late bus "; + callback = pm_late_early_op(dev->bus->pm, state); + } + if (callback) + goto Run; + + if (dev_pm_skip_suspend(dev)) + goto Skip; + + if (dev->driver && dev->driver->pm) { + info = "late driver "; + callback = pm_late_early_op(dev->driver->pm, state); + } + +Run: + error = dpm_run_callback(callback, dev, state, info); + if (error) { + async_error = error; + goto Complete; + } + dpm_propagate_wakeup_to_parent(dev); + +Skip: + dev->power.is_late_suspended = true; + +Complete: + TRACE_SUSPEND(error); + complete_all(&dev->power.completion); + return error; +} + +static void async_suspend_late(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = __device_suspend_late(dev, pm_transition, true); + if (error) { + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, pm_transition, " async", error); + } + put_device(dev); +} + +static int device_suspend_late(struct device *dev) +{ + if (dpm_async_fn(dev, async_suspend_late)) + return 0; + + return __device_suspend_late(dev, pm_transition, false); +} + +/** + * dpm_suspend_late - Execute "late suspend" callbacks for all devices. + * @state: PM transition of the system being carried out. + */ +int dpm_suspend_late(pm_message_t state) +{ + ktime_t starttime = ktime_get(); + int error = 0; + + trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true); + mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; + + while (!list_empty(&dpm_suspended_list)) { + struct device *dev = to_device(dpm_suspended_list.prev); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = device_suspend_late(dev); + + mutex_lock(&dpm_list_mtx); + if (!list_empty(&dev->power.entry)) + list_move(&dev->power.entry, &dpm_late_early_list); + + if (error) { + pm_dev_err(dev, state, " late", error); + dpm_save_failed_dev(dev_name(dev)); + put_device(dev); + break; + } + put_device(dev); + + if (async_error) + break; + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + if (!error) + error = async_error; + if (error) { + suspend_stats.failed_suspend_late++; + dpm_save_failed_step(SUSPEND_SUSPEND_LATE); + dpm_resume_early(resume_event(state)); + } + dpm_show_time(starttime, state, error, "late"); + trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false); + return error; +} + +/** + * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks. + * @state: PM transition of the system being carried out. + */ +int dpm_suspend_end(pm_message_t state) +{ + ktime_t starttime = ktime_get(); + int error; + + error = dpm_suspend_late(state); + if (error) + goto out; + + error = dpm_suspend_noirq(state); + if (error) + dpm_resume_early(resume_event(state)); + +out: + dpm_show_time(starttime, state, error, "end"); + return error; +} +EXPORT_SYMBOL_GPL(dpm_suspend_end); + +/** + * legacy_suspend - Execute a legacy (bus or class) suspend callback for device. + * @dev: Device to suspend. + * @state: PM transition of the system being carried out. + * @cb: Suspend callback to execute. + * @info: string description of caller. + */ +static int legacy_suspend(struct device *dev, pm_message_t state, + int (*cb)(struct device *dev, pm_message_t state), + const char *info) +{ + int error; + ktime_t calltime; + + calltime = initcall_debug_start(dev, cb); + + trace_device_pm_callback_start(dev, info, state.event); + error = cb(dev, state); + trace_device_pm_callback_end(dev, error); + suspend_report_result(cb, error); + + initcall_debug_report(dev, calltime, cb, error); + + return error; +} + +static void dpm_clear_superiors_direct_complete(struct device *dev) +{ + struct device_link *link; + int idx; + + if (dev->parent) { + spin_lock_irq(&dev->parent->power.lock); + dev->parent->power.direct_complete = false; + spin_unlock_irq(&dev->parent->power.lock); + } + + idx = device_links_read_lock(); + + list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) { + spin_lock_irq(&link->supplier->power.lock); + link->supplier->power.direct_complete = false; + spin_unlock_irq(&link->supplier->power.lock); + } + + device_links_read_unlock(idx); +} + +/** + * __device_suspend - Execute "suspend" callbacks for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * @async: If true, the device is being suspended asynchronously. + */ +static int __device_suspend(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + const char *info = NULL; + int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); + + TRACE_DEVICE(dev); + TRACE_SUSPEND(0); + + dpm_wait_for_subordinate(dev, async); + + if (async_error) { + dev->power.direct_complete = false; + goto Complete; + } + + /* + * Wait for possible runtime PM transitions of the device in progress + * to complete and if there's a runtime resume request pending for it, + * resume it before proceeding with invoking the system-wide suspend + * callbacks for it. + * + * If the system-wide suspend callbacks below change the configuration + * of the device, they must disable runtime PM for it or otherwise + * ensure that its runtime-resume callbacks will not be confused by that + * change in case they are invoked going forward. + */ + pm_runtime_barrier(dev); + + if (pm_wakeup_pending()) { + dev->power.direct_complete = false; + async_error = -EBUSY; + goto Complete; + } + + if (dev->power.syscore) + goto Complete; + + /* Avoid direct_complete to let wakeup_path propagate. */ + if (device_may_wakeup(dev) || dev->power.wakeup_path) + dev->power.direct_complete = false; + + if (dev->power.direct_complete) { + if (pm_runtime_status_suspended(dev)) { + pm_runtime_disable(dev); + if (pm_runtime_status_suspended(dev)) { + pm_dev_dbg(dev, state, "direct-complete "); + goto Complete; + } + + pm_runtime_enable(dev); + } + dev->power.direct_complete = false; + } + + dev->power.may_skip_resume = true; + dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME); + + dpm_watchdog_set(&wd, dev); + device_lock(dev); + + if (dev->pm_domain) { + info = "power domain "; + callback = pm_op(&dev->pm_domain->ops, state); + goto Run; + } + + if (dev->type && dev->type->pm) { + info = "type "; + callback = pm_op(dev->type->pm, state); + goto Run; + } + + if (dev->class && dev->class->pm) { + info = "class "; + callback = pm_op(dev->class->pm, state); + goto Run; + } + + if (dev->bus) { + if (dev->bus->pm) { + info = "bus "; + callback = pm_op(dev->bus->pm, state); + } else if (dev->bus->suspend) { + pm_dev_dbg(dev, state, "legacy bus "); + error = legacy_suspend(dev, state, dev->bus->suspend, + "legacy bus "); + goto End; + } + } + + Run: + if (!callback && dev->driver && dev->driver->pm) { + info = "driver "; + callback = pm_op(dev->driver->pm, state); + } + + error = dpm_run_callback(callback, dev, state, info); + + End: + if (!error) { + dev->power.is_suspended = true; + if (device_may_wakeup(dev)) + dev->power.wakeup_path = true; + + dpm_propagate_wakeup_to_parent(dev); + dpm_clear_superiors_direct_complete(dev); + } + + device_unlock(dev); + dpm_watchdog_clear(&wd); + + Complete: + if (error) + async_error = error; + + complete_all(&dev->power.completion); + TRACE_SUSPEND(error); + return error; +} + +static void async_suspend(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = __device_suspend(dev, pm_transition, true); + if (error) { + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, pm_transition, " async", error); + } + + put_device(dev); +} + +static int device_suspend(struct device *dev) +{ + if (dpm_async_fn(dev, async_suspend)) + return 0; + + return __device_suspend(dev, pm_transition, false); +} + +/** + * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices. + * @state: PM transition of the system being carried out. + */ +int dpm_suspend(pm_message_t state) +{ + ktime_t starttime = ktime_get(); + int error = 0; + + trace_suspend_resume(TPS("dpm_suspend"), state.event, true); + might_sleep(); + + devfreq_suspend(); + cpufreq_suspend(); + + mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; + while (!list_empty(&dpm_prepared_list)) { + struct device *dev = to_device(dpm_prepared_list.prev); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = device_suspend(dev); + + mutex_lock(&dpm_list_mtx); + if (error) { + pm_dev_err(dev, state, "", error); + dpm_save_failed_dev(dev_name(dev)); + put_device(dev); + break; + } + if (!list_empty(&dev->power.entry)) + list_move(&dev->power.entry, &dpm_suspended_list); + put_device(dev); + if (async_error) + break; + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + if (!error) + error = async_error; + if (error) { + suspend_stats.failed_suspend++; + dpm_save_failed_step(SUSPEND_SUSPEND); + } + dpm_show_time(starttime, state, error, NULL); + trace_suspend_resume(TPS("dpm_suspend"), state.event, false); + return error; +} + +/** + * device_prepare - Prepare a device for system power transition. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * + * Execute the ->prepare() callback(s) for given device. No new children of the + * device may be registered after this function has returned. + */ +static int device_prepare(struct device *dev, pm_message_t state) +{ + int (*callback)(struct device *) = NULL; + int ret = 0; + + /* + * If a device's parent goes into runtime suspend at the wrong time, + * it won't be possible to resume the device. To prevent this we + * block runtime suspend here, during the prepare phase, and allow + * it again during the complete phase. + */ + pm_runtime_get_noresume(dev); + + if (dev->power.syscore) + return 0; + + device_lock(dev); + + dev->power.wakeup_path = false; + + if (dev->power.no_pm_callbacks) + goto unlock; + + if (dev->pm_domain) + callback = dev->pm_domain->ops.prepare; + else if (dev->type && dev->type->pm) + callback = dev->type->pm->prepare; + else if (dev->class && dev->class->pm) + callback = dev->class->pm->prepare; + else if (dev->bus && dev->bus->pm) + callback = dev->bus->pm->prepare; + + if (!callback && dev->driver && dev->driver->pm) + callback = dev->driver->pm->prepare; + + if (callback) + ret = callback(dev); + +unlock: + device_unlock(dev); + + if (ret < 0) { + suspend_report_result(callback, ret); + pm_runtime_put(dev); + return ret; + } + /* + * A positive return value from ->prepare() means "this device appears + * to be runtime-suspended and its state is fine, so if it really is + * runtime-suspended, you can leave it in that state provided that you + * will do the same thing with all of its descendants". This only + * applies to suspend transitions, however. + */ + spin_lock_irq(&dev->power.lock); + dev->power.direct_complete = state.event == PM_EVENT_SUSPEND && + (ret > 0 || dev->power.no_pm_callbacks) && + !dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE); + spin_unlock_irq(&dev->power.lock); + return 0; +} + +/** + * dpm_prepare - Prepare all non-sysdev devices for a system PM transition. + * @state: PM transition of the system being carried out. + * + * Execute the ->prepare() callback(s) for all devices. + */ +int dpm_prepare(pm_message_t state) +{ + int error = 0; + + trace_suspend_resume(TPS("dpm_prepare"), state.event, true); + might_sleep(); + + /* + * Give a chance for the known devices to complete their probes, before + * disable probing of devices. This sync point is important at least + * at boot time + hibernation restore. + */ + wait_for_device_probe(); + /* + * It is unsafe if probing of devices will happen during suspend or + * hibernation and system behavior will be unpredictable in this case. + * So, let's prohibit device's probing here and defer their probes + * instead. The normal behavior will be restored in dpm_complete(). + */ + device_block_probing(); + + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_list)) { + struct device *dev = to_device(dpm_list.next); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + trace_device_pm_callback_start(dev, "", state.event); + error = device_prepare(dev, state); + trace_device_pm_callback_end(dev, error); + + mutex_lock(&dpm_list_mtx); + if (error) { + if (error == -EAGAIN) { + put_device(dev); + error = 0; + continue; + } + pr_info("Device %s not prepared for power transition: code %d\n", + dev_name(dev), error); + put_device(dev); + break; + } + dev->power.is_prepared = true; + if (!list_empty(&dev->power.entry)) + list_move_tail(&dev->power.entry, &dpm_prepared_list); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); + trace_suspend_resume(TPS("dpm_prepare"), state.event, false); + return error; +} + +/** + * dpm_suspend_start - Prepare devices for PM transition and suspend them. + * @state: PM transition of the system being carried out. + * + * Prepare all non-sysdev devices for system PM transition and execute "suspend" + * callbacks for them. + */ +int dpm_suspend_start(pm_message_t state) +{ + ktime_t starttime = ktime_get(); + int error; + + error = dpm_prepare(state); + if (error) { + suspend_stats.failed_prepare++; + dpm_save_failed_step(SUSPEND_PREPARE); + } else + error = dpm_suspend(state); + dpm_show_time(starttime, state, error, "start"); + return error; +} +EXPORT_SYMBOL_GPL(dpm_suspend_start); + +void __suspend_report_result(const char *function, void *fn, int ret) +{ + if (ret) + pr_err("%s(): %pS returns %d\n", function, fn, ret); +} +EXPORT_SYMBOL_GPL(__suspend_report_result); + +/** + * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete. + * @subordinate: Device that needs to wait for @dev. + * @dev: Device to wait for. + */ +int device_pm_wait_for_dev(struct device *subordinate, struct device *dev) +{ + dpm_wait(dev, subordinate->power.async_suspend); + return async_error; +} +EXPORT_SYMBOL_GPL(device_pm_wait_for_dev); + +/** + * dpm_for_each_dev - device iterator. + * @data: data for the callback. + * @fn: function to be called for each device. + * + * Iterate over devices in dpm_list, and call @fn for each device, + * passing it @data. + */ +void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *)) +{ + struct device *dev; + + if (!fn) + return; + + device_pm_lock(); + list_for_each_entry(dev, &dpm_list, power.entry) + fn(dev, data); + device_pm_unlock(); +} +EXPORT_SYMBOL_GPL(dpm_for_each_dev); + +static bool pm_ops_is_empty(const struct dev_pm_ops *ops) +{ + if (!ops) + return true; + + return !ops->prepare && + !ops->suspend && + !ops->suspend_late && + !ops->suspend_noirq && + !ops->resume_noirq && + !ops->resume_early && + !ops->resume && + !ops->complete; +} + +void device_pm_check_callbacks(struct device *dev) +{ + unsigned long flags; + + spin_lock_irqsave(&dev->power.lock, flags); + dev->power.no_pm_callbacks = + (!dev->bus || (pm_ops_is_empty(dev->bus->pm) && + !dev->bus->suspend && !dev->bus->resume)) && + (!dev->class || pm_ops_is_empty(dev->class->pm)) && + (!dev->type || pm_ops_is_empty(dev->type->pm)) && + (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) && + (!dev->driver || (pm_ops_is_empty(dev->driver->pm) && + !dev->driver->suspend && !dev->driver->resume)); + spin_unlock_irqrestore(&dev->power.lock, flags); +} + +bool dev_pm_skip_suspend(struct device *dev) +{ + return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) && + pm_runtime_status_suspended(dev); +} |