diff options
Diffstat (limited to 'kernel/drivers/base/power/domain.c')
| -rw-r--r-- | kernel/drivers/base/power/domain.c | 2381 |
1 files changed, 2381 insertions, 0 deletions
diff --git a/kernel/drivers/base/power/domain.c b/kernel/drivers/base/power/domain.c new file mode 100644 index 000000000..2327613d4 --- /dev/null +++ b/kernel/drivers/base/power/domain.c @@ -0,0 +1,2381 @@ +/* + * drivers/base/power/domain.c - Common code related to device power domains. + * + * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. + * + * This file is released under the GPLv2. + */ + +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/pm_domain.h> +#include <linux/pm_qos.h> +#include <linux/pm_clock.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/sched.h> +#include <linux/suspend.h> +#include <linux/export.h> + +#define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \ +({ \ + type (*__routine)(struct device *__d); \ + type __ret = (type)0; \ + \ + __routine = genpd->dev_ops.callback; \ + if (__routine) { \ + __ret = __routine(dev); \ + } \ + __ret; \ +}) + +#define GENPD_DEV_TIMED_CALLBACK(genpd, type, callback, dev, field, name) \ +({ \ + ktime_t __start = ktime_get(); \ + type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev); \ + s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start)); \ + struct gpd_timing_data *__td = &dev_gpd_data(dev)->td; \ + if (!__retval && __elapsed > __td->field) { \ + __td->field = __elapsed; \ + dev_dbg(dev, name " latency exceeded, new value %lld ns\n", \ + __elapsed); \ + genpd->max_off_time_changed = true; \ + __td->constraint_changed = true; \ + } \ + __retval; \ +}) + +static LIST_HEAD(gpd_list); +static DEFINE_MUTEX(gpd_list_lock); + +static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name) +{ + struct generic_pm_domain *genpd = NULL, *gpd; + + if (IS_ERR_OR_NULL(domain_name)) + return NULL; + + mutex_lock(&gpd_list_lock); + list_for_each_entry(gpd, &gpd_list, gpd_list_node) { + if (!strcmp(gpd->name, domain_name)) { + genpd = gpd; + break; + } + } + mutex_unlock(&gpd_list_lock); + return genpd; +} + +/* + * Get the generic PM domain for a particular struct device. + * This validates the struct device pointer, the PM domain pointer, + * and checks that the PM domain pointer is a real generic PM domain. + * Any failure results in NULL being returned. + */ +struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev) +{ + struct generic_pm_domain *genpd = NULL, *gpd; + + if (IS_ERR_OR_NULL(dev) || IS_ERR_OR_NULL(dev->pm_domain)) + return NULL; + + mutex_lock(&gpd_list_lock); + list_for_each_entry(gpd, &gpd_list, gpd_list_node) { + if (&gpd->domain == dev->pm_domain) { + genpd = gpd; + break; + } + } + mutex_unlock(&gpd_list_lock); + + return genpd; +} + +/* + * This should only be used where we are certain that the pm_domain + * attached to the device is a genpd domain. + */ +static struct generic_pm_domain *dev_to_genpd(struct device *dev) +{ + if (IS_ERR_OR_NULL(dev->pm_domain)) + return ERR_PTR(-EINVAL); + + return pd_to_genpd(dev->pm_domain); +} + +static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev) +{ + return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev, + stop_latency_ns, "stop"); +} + +static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev) +{ + return GENPD_DEV_TIMED_CALLBACK(genpd, int, start, dev, + start_latency_ns, "start"); +} + +static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd) +{ + bool ret = false; + + if (!WARN_ON(atomic_read(&genpd->sd_count) == 0)) + ret = !!atomic_dec_and_test(&genpd->sd_count); + + return ret; +} + +static void genpd_sd_counter_inc(struct generic_pm_domain *genpd) +{ + atomic_inc(&genpd->sd_count); + smp_mb__after_atomic(); +} + +static void genpd_acquire_lock(struct generic_pm_domain *genpd) +{ + DEFINE_WAIT(wait); + + mutex_lock(&genpd->lock); + /* + * Wait for the domain to transition into either the active, + * or the power off state. + */ + for (;;) { + prepare_to_wait(&genpd->status_wait_queue, &wait, + TASK_UNINTERRUPTIBLE); + if (genpd->status == GPD_STATE_ACTIVE + || genpd->status == GPD_STATE_POWER_OFF) + break; + mutex_unlock(&genpd->lock); + + schedule(); + + mutex_lock(&genpd->lock); + } + finish_wait(&genpd->status_wait_queue, &wait); +} + +static void genpd_release_lock(struct generic_pm_domain *genpd) +{ + mutex_unlock(&genpd->lock); +} + +static void genpd_set_active(struct generic_pm_domain *genpd) +{ + if (genpd->resume_count == 0) + genpd->status = GPD_STATE_ACTIVE; +} + +static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd) +{ + s64 usecs64; + + if (!genpd->cpuidle_data) + return; + + usecs64 = genpd->power_on_latency_ns; + do_div(usecs64, NSEC_PER_USEC); + usecs64 += genpd->cpuidle_data->saved_exit_latency; + genpd->cpuidle_data->idle_state->exit_latency = usecs64; +} + +static int genpd_power_on(struct generic_pm_domain *genpd) +{ + ktime_t time_start; + s64 elapsed_ns; + int ret; + + if (!genpd->power_on) + return 0; + + time_start = ktime_get(); + ret = genpd->power_on(genpd); + if (ret) + return ret; + + elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); + if (elapsed_ns <= genpd->power_on_latency_ns) + return ret; + + genpd->power_on_latency_ns = elapsed_ns; + genpd->max_off_time_changed = true; + genpd_recalc_cpu_exit_latency(genpd); + pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n", + genpd->name, "on", elapsed_ns); + + return ret; +} + +static int genpd_power_off(struct generic_pm_domain *genpd) +{ + ktime_t time_start; + s64 elapsed_ns; + int ret; + + if (!genpd->power_off) + return 0; + + time_start = ktime_get(); + ret = genpd->power_off(genpd); + if (ret == -EBUSY) + return ret; + + elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); + if (elapsed_ns <= genpd->power_off_latency_ns) + return ret; + + genpd->power_off_latency_ns = elapsed_ns; + genpd->max_off_time_changed = true; + pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n", + genpd->name, "off", elapsed_ns); + + return ret; +} + +/** + * __pm_genpd_poweron - Restore power to a given PM domain and its masters. + * @genpd: PM domain to power up. + * + * Restore power to @genpd and all of its masters so that it is possible to + * resume a device belonging to it. + */ +static int __pm_genpd_poweron(struct generic_pm_domain *genpd) + __releases(&genpd->lock) __acquires(&genpd->lock) +{ + struct gpd_link *link; + DEFINE_WAIT(wait); + int ret = 0; + + /* If the domain's master is being waited for, we have to wait too. */ + for (;;) { + prepare_to_wait(&genpd->status_wait_queue, &wait, + TASK_UNINTERRUPTIBLE); + if (genpd->status != GPD_STATE_WAIT_MASTER) + break; + mutex_unlock(&genpd->lock); + + schedule(); + + mutex_lock(&genpd->lock); + } + finish_wait(&genpd->status_wait_queue, &wait); + + if (genpd->status == GPD_STATE_ACTIVE + || (genpd->prepared_count > 0 && genpd->suspend_power_off)) + return 0; + + if (genpd->status != GPD_STATE_POWER_OFF) { + genpd_set_active(genpd); + return 0; + } + + if (genpd->cpuidle_data) { + cpuidle_pause_and_lock(); + genpd->cpuidle_data->idle_state->disabled = true; + cpuidle_resume_and_unlock(); + goto out; + } + + /* + * The list is guaranteed not to change while the loop below is being + * executed, unless one of the masters' .power_on() callbacks fiddles + * with it. + */ + list_for_each_entry(link, &genpd->slave_links, slave_node) { + genpd_sd_counter_inc(link->master); + genpd->status = GPD_STATE_WAIT_MASTER; + + mutex_unlock(&genpd->lock); + + ret = pm_genpd_poweron(link->master); + + mutex_lock(&genpd->lock); + + /* + * The "wait for parent" status is guaranteed not to change + * while the master is powering on. + */ + genpd->status = GPD_STATE_POWER_OFF; + wake_up_all(&genpd->status_wait_queue); + if (ret) { + genpd_sd_counter_dec(link->master); + goto err; + } + } + + ret = genpd_power_on(genpd); + if (ret) + goto err; + + out: + genpd_set_active(genpd); + + return 0; + + err: + list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node) + genpd_sd_counter_dec(link->master); + + return ret; +} + +/** + * pm_genpd_poweron - Restore power to a given PM domain and its masters. + * @genpd: PM domain to power up. + */ +int pm_genpd_poweron(struct generic_pm_domain *genpd) +{ + int ret; + + mutex_lock(&genpd->lock); + ret = __pm_genpd_poweron(genpd); + mutex_unlock(&genpd->lock); + return ret; +} + +/** + * pm_genpd_name_poweron - Restore power to a given PM domain and its masters. + * @domain_name: Name of the PM domain to power up. + */ +int pm_genpd_name_poweron(const char *domain_name) +{ + struct generic_pm_domain *genpd; + + genpd = pm_genpd_lookup_name(domain_name); + return genpd ? pm_genpd_poweron(genpd) : -EINVAL; +} + +static int genpd_start_dev_no_timing(struct generic_pm_domain *genpd, + struct device *dev) +{ + return GENPD_DEV_CALLBACK(genpd, int, start, dev); +} + +static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev) +{ + return GENPD_DEV_TIMED_CALLBACK(genpd, int, save_state, dev, + save_state_latency_ns, "state save"); +} + +static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev) +{ + return GENPD_DEV_TIMED_CALLBACK(genpd, int, restore_state, dev, + restore_state_latency_ns, + "state restore"); +} + +static int genpd_dev_pm_qos_notifier(struct notifier_block *nb, + unsigned long val, void *ptr) +{ + struct generic_pm_domain_data *gpd_data; + struct device *dev; + + gpd_data = container_of(nb, struct generic_pm_domain_data, nb); + dev = gpd_data->base.dev; + + for (;;) { + struct generic_pm_domain *genpd; + struct pm_domain_data *pdd; + + spin_lock_irq(&dev->power.lock); + + pdd = dev->power.subsys_data ? + dev->power.subsys_data->domain_data : NULL; + if (pdd && pdd->dev) { + to_gpd_data(pdd)->td.constraint_changed = true; + genpd = dev_to_genpd(dev); + } else { + genpd = ERR_PTR(-ENODATA); + } + + spin_unlock_irq(&dev->power.lock); + + if (!IS_ERR(genpd)) { + mutex_lock(&genpd->lock); + genpd->max_off_time_changed = true; + mutex_unlock(&genpd->lock); + } + + dev = dev->parent; + if (!dev || dev->power.ignore_children) + break; + } + + return NOTIFY_DONE; +} + +/** + * __pm_genpd_save_device - Save the pre-suspend state of a device. + * @pdd: Domain data of the device to save the state of. + * @genpd: PM domain the device belongs to. + */ +static int __pm_genpd_save_device(struct pm_domain_data *pdd, + struct generic_pm_domain *genpd) + __releases(&genpd->lock) __acquires(&genpd->lock) +{ + struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); + struct device *dev = pdd->dev; + int ret = 0; + + if (gpd_data->need_restore > 0) + return 0; + + /* + * If the value of the need_restore flag is still unknown at this point, + * we trust that pm_genpd_poweroff() has verified that the device is + * already runtime PM suspended. + */ + if (gpd_data->need_restore < 0) { + gpd_data->need_restore = 1; + return 0; + } + + mutex_unlock(&genpd->lock); + + genpd_start_dev(genpd, dev); + ret = genpd_save_dev(genpd, dev); + genpd_stop_dev(genpd, dev); + + mutex_lock(&genpd->lock); + + if (!ret) + gpd_data->need_restore = 1; + + return ret; +} + +/** + * __pm_genpd_restore_device - Restore the pre-suspend state of a device. + * @pdd: Domain data of the device to restore the state of. + * @genpd: PM domain the device belongs to. + */ +static void __pm_genpd_restore_device(struct pm_domain_data *pdd, + struct generic_pm_domain *genpd) + __releases(&genpd->lock) __acquires(&genpd->lock) +{ + struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); + struct device *dev = pdd->dev; + int need_restore = gpd_data->need_restore; + + gpd_data->need_restore = 0; + mutex_unlock(&genpd->lock); + + genpd_start_dev(genpd, dev); + + /* + * Call genpd_restore_dev() for recently added devices too (need_restore + * is negative then). + */ + if (need_restore) + genpd_restore_dev(genpd, dev); + + mutex_lock(&genpd->lock); +} + +/** + * genpd_abort_poweroff - Check if a PM domain power off should be aborted. + * @genpd: PM domain to check. + * + * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during + * a "power off" operation, which means that a "power on" has occured in the + * meantime, or if its resume_count field is different from zero, which means + * that one of its devices has been resumed in the meantime. + */ +static bool genpd_abort_poweroff(struct generic_pm_domain *genpd) +{ + return genpd->status == GPD_STATE_WAIT_MASTER + || genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0; +} + +/** + * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff(). + * @genpd: PM domait to power off. + * + * Queue up the execution of pm_genpd_poweroff() unless it's already been done + * before. + */ +static void genpd_queue_power_off_work(struct generic_pm_domain *genpd) +{ + queue_work(pm_wq, &genpd->power_off_work); +} + +/** + * pm_genpd_poweroff - Remove power from a given PM domain. + * @genpd: PM domain to power down. + * + * If all of the @genpd's devices have been suspended and all of its subdomains + * have been powered down, run the runtime suspend callbacks provided by all of + * the @genpd's devices' drivers and remove power from @genpd. + */ +static int pm_genpd_poweroff(struct generic_pm_domain *genpd) + __releases(&genpd->lock) __acquires(&genpd->lock) +{ + struct pm_domain_data *pdd; + struct gpd_link *link; + unsigned int not_suspended; + int ret = 0; + + start: + /* + * Do not try to power off the domain in the following situations: + * (1) The domain is already in the "power off" state. + * (2) The domain is waiting for its master to power up. + * (3) One of the domain's devices is being resumed right now. + * (4) System suspend is in progress. + */ + if (genpd->status == GPD_STATE_POWER_OFF + || genpd->status == GPD_STATE_WAIT_MASTER + || genpd->resume_count > 0 || genpd->prepared_count > 0) + return 0; + + if (atomic_read(&genpd->sd_count) > 0) + return -EBUSY; + + not_suspended = 0; + list_for_each_entry(pdd, &genpd->dev_list, list_node) { + enum pm_qos_flags_status stat; + + stat = dev_pm_qos_flags(pdd->dev, + PM_QOS_FLAG_NO_POWER_OFF + | PM_QOS_FLAG_REMOTE_WAKEUP); + if (stat > PM_QOS_FLAGS_NONE) + return -EBUSY; + + if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev) + || pdd->dev->power.irq_safe)) + not_suspended++; + } + + if (not_suspended > genpd->in_progress) + return -EBUSY; + + if (genpd->poweroff_task) { + /* + * Another instance of pm_genpd_poweroff() is executing + * callbacks, so tell it to start over and return. + */ + genpd->status = GPD_STATE_REPEAT; + return 0; + } + + if (genpd->gov && genpd->gov->power_down_ok) { + if (!genpd->gov->power_down_ok(&genpd->domain)) + return -EAGAIN; + } + + genpd->status = GPD_STATE_BUSY; + genpd->poweroff_task = current; + + list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) { + ret = atomic_read(&genpd->sd_count) == 0 ? + __pm_genpd_save_device(pdd, genpd) : -EBUSY; + + if (genpd_abort_poweroff(genpd)) + goto out; + + if (ret) { + genpd_set_active(genpd); + goto out; + } + + if (genpd->status == GPD_STATE_REPEAT) { + genpd->poweroff_task = NULL; + goto start; + } + } + + if (genpd->cpuidle_data) { + /* + * If cpuidle_data is set, cpuidle should turn the domain off + * when the CPU in it is idle. In that case we don't decrement + * the subdomain counts of the master domains, so that power is + * not removed from the current domain prematurely as a result + * of cutting off the masters' power. + */ + genpd->status = GPD_STATE_POWER_OFF; + cpuidle_pause_and_lock(); + genpd->cpuidle_data->idle_state->disabled = false; + cpuidle_resume_and_unlock(); + goto out; + } + + if (genpd->power_off) { + if (atomic_read(&genpd->sd_count) > 0) { + ret = -EBUSY; + goto out; + } + + /* + * If sd_count > 0 at this point, one of the subdomains hasn't + * managed to call pm_genpd_poweron() for the master yet after + * incrementing it. In that case pm_genpd_poweron() will wait + * for us to drop the lock, so we can call .power_off() and let + * the pm_genpd_poweron() restore power for us (this shouldn't + * happen very often). + */ + ret = genpd_power_off(genpd); + if (ret == -EBUSY) { + genpd_set_active(genpd); + goto out; + } + } + + genpd->status = GPD_STATE_POWER_OFF; + + list_for_each_entry(link, &genpd->slave_links, slave_node) { + genpd_sd_counter_dec(link->master); + genpd_queue_power_off_work(link->master); + } + + out: + genpd->poweroff_task = NULL; + wake_up_all(&genpd->status_wait_queue); + return ret; +} + +/** + * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0. + * @work: Work structure used for scheduling the execution of this function. + */ +static void genpd_power_off_work_fn(struct work_struct *work) +{ + struct generic_pm_domain *genpd; + + genpd = container_of(work, struct generic_pm_domain, power_off_work); + + genpd_acquire_lock(genpd); + pm_genpd_poweroff(genpd); + genpd_release_lock(genpd); +} + +/** + * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain. + * @dev: Device to suspend. + * + * Carry out a runtime suspend of a device under the assumption that its + * pm_domain field points to the domain member of an object of type + * struct generic_pm_domain representing a PM domain consisting of I/O devices. + */ +static int pm_genpd_runtime_suspend(struct device *dev) +{ + struct generic_pm_domain *genpd; + struct generic_pm_domain_data *gpd_data; + bool (*stop_ok)(struct device *__dev); + int ret; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL; + if (stop_ok && !stop_ok(dev)) + return -EBUSY; + + ret = genpd_stop_dev(genpd, dev); + if (ret) + return ret; + + /* + * If power.irq_safe is set, this routine will be run with interrupts + * off, so it can't use mutexes. + */ + if (dev->power.irq_safe) + return 0; + + mutex_lock(&genpd->lock); + + /* + * If we have an unknown state of the need_restore flag, it means none + * of the runtime PM callbacks has been invoked yet. Let's update the + * flag to reflect that the current state is active. + */ + gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); + if (gpd_data->need_restore < 0) + gpd_data->need_restore = 0; + + genpd->in_progress++; + pm_genpd_poweroff(genpd); + genpd->in_progress--; + mutex_unlock(&genpd->lock); + + return 0; +} + +/** + * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain. + * @dev: Device to resume. + * + * Carry out a runtime resume of a device under the assumption that its + * pm_domain field points to the domain member of an object of type + * struct generic_pm_domain representing a PM domain consisting of I/O devices. + */ +static int pm_genpd_runtime_resume(struct device *dev) +{ + struct generic_pm_domain *genpd; + DEFINE_WAIT(wait); + int ret; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + /* If power.irq_safe, the PM domain is never powered off. */ + if (dev->power.irq_safe) + return genpd_start_dev_no_timing(genpd, dev); + + mutex_lock(&genpd->lock); + ret = __pm_genpd_poweron(genpd); + if (ret) { + mutex_unlock(&genpd->lock); + return ret; + } + genpd->status = GPD_STATE_BUSY; + genpd->resume_count++; + for (;;) { + prepare_to_wait(&genpd->status_wait_queue, &wait, + TASK_UNINTERRUPTIBLE); + /* + * If current is the powering off task, we have been called + * reentrantly from one of the device callbacks, so we should + * not wait. + */ + if (!genpd->poweroff_task || genpd->poweroff_task == current) + break; + mutex_unlock(&genpd->lock); + + schedule(); + + mutex_lock(&genpd->lock); + } + finish_wait(&genpd->status_wait_queue, &wait); + __pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd); + genpd->resume_count--; + genpd_set_active(genpd); + wake_up_all(&genpd->status_wait_queue); + mutex_unlock(&genpd->lock); + + return 0; +} + +static bool pd_ignore_unused; +static int __init pd_ignore_unused_setup(char *__unused) +{ + pd_ignore_unused = true; + return 1; +} +__setup("pd_ignore_unused", pd_ignore_unused_setup); + +/** + * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use. + */ +void pm_genpd_poweroff_unused(void) +{ + struct generic_pm_domain *genpd; + + if (pd_ignore_unused) { + pr_warn("genpd: Not disabling unused power domains\n"); + return; + } + + mutex_lock(&gpd_list_lock); + + list_for_each_entry(genpd, &gpd_list, gpd_list_node) + genpd_queue_power_off_work(genpd); + + mutex_unlock(&gpd_list_lock); +} + +static int __init genpd_poweroff_unused(void) +{ + pm_genpd_poweroff_unused(); + return 0; +} +late_initcall(genpd_poweroff_unused); + +#ifdef CONFIG_PM_SLEEP + +/** + * pm_genpd_present - Check if the given PM domain has been initialized. + * @genpd: PM domain to check. + */ +static bool pm_genpd_present(const struct generic_pm_domain *genpd) +{ + const struct generic_pm_domain *gpd; + + if (IS_ERR_OR_NULL(genpd)) + return false; + + list_for_each_entry(gpd, &gpd_list, gpd_list_node) + if (gpd == genpd) + return true; + + return false; +} + +static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd, + struct device *dev) +{ + return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev); +} + +/** + * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters. + * @genpd: PM domain to power off, if possible. + * + * Check if the given PM domain can be powered off (during system suspend or + * hibernation) and do that if so. Also, in that case propagate to its masters. + * + * This function is only called in "noirq" and "syscore" stages of system power + * transitions, so it need not acquire locks (all of the "noirq" callbacks are + * executed sequentially, so it is guaranteed that it will never run twice in + * parallel). + */ +static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd) +{ + struct gpd_link *link; + + if (genpd->status == GPD_STATE_POWER_OFF) + return; + + if (genpd->suspended_count != genpd->device_count + || atomic_read(&genpd->sd_count) > 0) + return; + + genpd_power_off(genpd); + + genpd->status = GPD_STATE_POWER_OFF; + + list_for_each_entry(link, &genpd->slave_links, slave_node) { + genpd_sd_counter_dec(link->master); + pm_genpd_sync_poweroff(link->master); + } +} + +/** + * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters. + * @genpd: PM domain to power on. + * + * This function is only called in "noirq" and "syscore" stages of system power + * transitions, so it need not acquire locks (all of the "noirq" callbacks are + * executed sequentially, so it is guaranteed that it will never run twice in + * parallel). + */ +static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd) +{ + struct gpd_link *link; + + if (genpd->status != GPD_STATE_POWER_OFF) + return; + + list_for_each_entry(link, &genpd->slave_links, slave_node) { + pm_genpd_sync_poweron(link->master); + genpd_sd_counter_inc(link->master); + } + + genpd_power_on(genpd); + + genpd->status = GPD_STATE_ACTIVE; +} + +/** + * resume_needed - Check whether to resume a device before system suspend. + * @dev: Device to check. + * @genpd: PM domain the device belongs to. + * + * There are two cases in which a device that can wake up the system from sleep + * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled + * to wake up the system and it has to remain active for this purpose while the + * system is in the sleep state and (2) if the device is not enabled to wake up + * the system from sleep states and it generally doesn't generate wakeup signals + * by itself (those signals are generated on its behalf by other parts of the + * system). In the latter case it may be necessary to reconfigure the device's + * wakeup settings during system suspend, because it may have been set up to + * signal remote wakeup from the system's working state as needed by runtime PM. + * Return 'true' in either of the above cases. + */ +static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd) +{ + bool active_wakeup; + + if (!device_can_wakeup(dev)) + return false; + + active_wakeup = genpd_dev_active_wakeup(genpd, dev); + return device_may_wakeup(dev) ? active_wakeup : !active_wakeup; +} + +/** + * pm_genpd_prepare - Start power transition of a device in a PM domain. + * @dev: Device to start the transition of. + * + * Start a power transition of a device (during a system-wide power transition) + * under the assumption that its pm_domain field points to the domain member of + * an object of type struct generic_pm_domain representing a PM domain + * consisting of I/O devices. + */ +static int pm_genpd_prepare(struct device *dev) +{ + struct generic_pm_domain *genpd; + int ret; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + /* + * If a wakeup request is pending for the device, it should be woken up + * at this point and a system wakeup event should be reported if it's + * set up to wake up the system from sleep states. + */ + pm_runtime_get_noresume(dev); + if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) + pm_wakeup_event(dev, 0); + + if (pm_wakeup_pending()) { + pm_runtime_put(dev); + return -EBUSY; + } + + if (resume_needed(dev, genpd)) + pm_runtime_resume(dev); + + genpd_acquire_lock(genpd); + + if (genpd->prepared_count++ == 0) { + genpd->suspended_count = 0; + genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF; + } + + genpd_release_lock(genpd); + + if (genpd->suspend_power_off) { + pm_runtime_put_noidle(dev); + return 0; + } + + /* + * The PM domain must be in the GPD_STATE_ACTIVE state at this point, + * so pm_genpd_poweron() will return immediately, but if the device + * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need + * to make it operational. + */ + pm_runtime_resume(dev); + __pm_runtime_disable(dev, false); + + ret = pm_generic_prepare(dev); + if (ret) { + mutex_lock(&genpd->lock); + + if (--genpd->prepared_count == 0) + genpd->suspend_power_off = false; + + mutex_unlock(&genpd->lock); + pm_runtime_enable(dev); + } + + pm_runtime_put(dev); + return ret; +} + +/** + * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain. + * @dev: Device to suspend. + * + * Suspend a device under the assumption that its pm_domain field points to the + * domain member of an object of type struct generic_pm_domain representing + * a PM domain consisting of I/O devices. + */ +static int pm_genpd_suspend(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev); +} + +/** + * pm_genpd_suspend_late - Late suspend of a device from an I/O PM domain. + * @dev: Device to suspend. + * + * Carry out a late suspend of a device under the assumption that its + * pm_domain field points to the domain member of an object of type + * struct generic_pm_domain representing a PM domain consisting of I/O devices. + */ +static int pm_genpd_suspend_late(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_suspend_late(dev); +} + +/** + * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain. + * @dev: Device to suspend. + * + * Stop the device and remove power from the domain if all devices in it have + * been stopped. + */ +static int pm_genpd_suspend_noirq(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + if (genpd->suspend_power_off + || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev))) + return 0; + + genpd_stop_dev(genpd, dev); + + /* + * Since all of the "noirq" callbacks are executed sequentially, it is + * guaranteed that this function will never run twice in parallel for + * the same PM domain, so it is not necessary to use locking here. + */ + genpd->suspended_count++; + pm_genpd_sync_poweroff(genpd); + + return 0; +} + +/** + * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain. + * @dev: Device to resume. + * + * Restore power to the device's PM domain, if necessary, and start the device. + */ +static int pm_genpd_resume_noirq(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + if (genpd->suspend_power_off + || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev))) + return 0; + + /* + * Since all of the "noirq" callbacks are executed sequentially, it is + * guaranteed that this function will never run twice in parallel for + * the same PM domain, so it is not necessary to use locking here. + */ + pm_genpd_sync_poweron(genpd); + genpd->suspended_count--; + + return genpd_start_dev(genpd, dev); +} + +/** + * pm_genpd_resume_early - Early resume of a device in an I/O PM domain. + * @dev: Device to resume. + * + * Carry out an early resume of a device under the assumption that its + * pm_domain field points to the domain member of an object of type + * struct generic_pm_domain representing a power domain consisting of I/O + * devices. + */ +static int pm_genpd_resume_early(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_resume_early(dev); +} + +/** + * pm_genpd_resume - Resume of device in an I/O PM domain. + * @dev: Device to resume. + * + * Resume a device under the assumption that its pm_domain field points to the + * domain member of an object of type struct generic_pm_domain representing + * a power domain consisting of I/O devices. + */ +static int pm_genpd_resume(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_resume(dev); +} + +/** + * pm_genpd_freeze - Freezing a device in an I/O PM domain. + * @dev: Device to freeze. + * + * Freeze a device under the assumption that its pm_domain field points to the + * domain member of an object of type struct generic_pm_domain representing + * a power domain consisting of I/O devices. + */ +static int pm_genpd_freeze(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev); +} + +/** + * pm_genpd_freeze_late - Late freeze of a device in an I/O PM domain. + * @dev: Device to freeze. + * + * Carry out a late freeze of a device under the assumption that its + * pm_domain field points to the domain member of an object of type + * struct generic_pm_domain representing a power domain consisting of I/O + * devices. + */ +static int pm_genpd_freeze_late(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_freeze_late(dev); +} + +/** + * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain. + * @dev: Device to freeze. + * + * Carry out a late freeze of a device under the assumption that its + * pm_domain field points to the domain member of an object of type + * struct generic_pm_domain representing a power domain consisting of I/O + * devices. + */ +static int pm_genpd_freeze_noirq(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev); +} + +/** + * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain. + * @dev: Device to thaw. + * + * Start the device, unless power has been removed from the domain already + * before the system transition. + */ +static int pm_genpd_thaw_noirq(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev); +} + +/** + * pm_genpd_thaw_early - Early thaw of device in an I/O PM domain. + * @dev: Device to thaw. + * + * Carry out an early thaw of a device under the assumption that its + * pm_domain field points to the domain member of an object of type + * struct generic_pm_domain representing a power domain consisting of I/O + * devices. + */ +static int pm_genpd_thaw_early(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_thaw_early(dev); +} + +/** + * pm_genpd_thaw - Thaw a device belonging to an I/O power domain. + * @dev: Device to thaw. + * + * Thaw a device under the assumption that its pm_domain field points to the + * domain member of an object of type struct generic_pm_domain representing + * a power domain consisting of I/O devices. + */ +static int pm_genpd_thaw(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev); +} + +/** + * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain. + * @dev: Device to resume. + * + * Make sure the domain will be in the same power state as before the + * hibernation the system is resuming from and start the device if necessary. + */ +static int pm_genpd_restore_noirq(struct device *dev) +{ + struct generic_pm_domain *genpd; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return -EINVAL; + + /* + * Since all of the "noirq" callbacks are executed sequentially, it is + * guaranteed that this function will never run twice in parallel for + * the same PM domain, so it is not necessary to use locking here. + * + * At this point suspended_count == 0 means we are being run for the + * first time for the given domain in the present cycle. + */ + if (genpd->suspended_count++ == 0) { + /* + * The boot kernel might put the domain into arbitrary state, + * so make it appear as powered off to pm_genpd_sync_poweron(), + * so that it tries to power it on in case it was really off. + */ + genpd->status = GPD_STATE_POWER_OFF; + if (genpd->suspend_power_off) { + /* + * If the domain was off before the hibernation, make + * sure it will be off going forward. + */ + genpd_power_off(genpd); + + return 0; + } + } + + if (genpd->suspend_power_off) + return 0; + + pm_genpd_sync_poweron(genpd); + + return genpd_start_dev(genpd, dev); +} + +/** + * pm_genpd_complete - Complete power transition of a device in a power domain. + * @dev: Device to complete the transition of. + * + * Complete a power transition of a device (during a system-wide power + * transition) under the assumption that its pm_domain field points to the + * domain member of an object of type struct generic_pm_domain representing + * a power domain consisting of I/O devices. + */ +static void pm_genpd_complete(struct device *dev) +{ + struct generic_pm_domain *genpd; + bool run_complete; + + dev_dbg(dev, "%s()\n", __func__); + + genpd = dev_to_genpd(dev); + if (IS_ERR(genpd)) + return; + + mutex_lock(&genpd->lock); + + run_complete = !genpd->suspend_power_off; + if (--genpd->prepared_count == 0) + genpd->suspend_power_off = false; + + mutex_unlock(&genpd->lock); + + if (run_complete) { + pm_generic_complete(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + pm_request_idle(dev); + } +} + +/** + * genpd_syscore_switch - Switch power during system core suspend or resume. + * @dev: Device that normally is marked as "always on" to switch power for. + * + * This routine may only be called during the system core (syscore) suspend or + * resume phase for devices whose "always on" flags are set. + */ +static void genpd_syscore_switch(struct device *dev, bool suspend) +{ + struct generic_pm_domain *genpd; + + genpd = dev_to_genpd(dev); + if (!pm_genpd_present(genpd)) + return; + + if (suspend) { + genpd->suspended_count++; + pm_genpd_sync_poweroff(genpd); + } else { + pm_genpd_sync_poweron(genpd); + genpd->suspended_count--; + } +} + +void pm_genpd_syscore_poweroff(struct device *dev) +{ + genpd_syscore_switch(dev, true); +} +EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff); + +void pm_genpd_syscore_poweron(struct device *dev) +{ + genpd_syscore_switch(dev, false); +} +EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron); + +#else /* !CONFIG_PM_SLEEP */ + +#define pm_genpd_prepare NULL +#define pm_genpd_suspend NULL +#define pm_genpd_suspend_late NULL +#define pm_genpd_suspend_noirq NULL +#define pm_genpd_resume_early NULL +#define pm_genpd_resume_noirq NULL +#define pm_genpd_resume NULL +#define pm_genpd_freeze NULL +#define pm_genpd_freeze_late NULL +#define pm_genpd_freeze_noirq NULL +#define pm_genpd_thaw_early NULL +#define pm_genpd_thaw_noirq NULL +#define pm_genpd_thaw NULL +#define pm_genpd_restore_noirq NULL +#define pm_genpd_complete NULL + +#endif /* CONFIG_PM_SLEEP */ + +static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev, + struct generic_pm_domain *genpd, + struct gpd_timing_data *td) +{ + struct generic_pm_domain_data *gpd_data; + int ret; + + ret = dev_pm_get_subsys_data(dev); + if (ret) + return ERR_PTR(ret); + + gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL); + if (!gpd_data) { + ret = -ENOMEM; + goto err_put; + } + + if (td) + gpd_data->td = *td; + + gpd_data->base.dev = dev; + gpd_data->need_restore = -1; + gpd_data->td.constraint_changed = true; + gpd_data->td.effective_constraint_ns = -1; + gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; + + spin_lock_irq(&dev->power.lock); + + if (dev->power.subsys_data->domain_data) { + ret = -EINVAL; + goto err_free; + } + + dev->power.subsys_data->domain_data = &gpd_data->base; + dev->pm_domain = &genpd->domain; + + spin_unlock_irq(&dev->power.lock); + + return gpd_data; + + err_free: + spin_unlock_irq(&dev->power.lock); + kfree(gpd_data); + err_put: + dev_pm_put_subsys_data(dev); + return ERR_PTR(ret); +} + +static void genpd_free_dev_data(struct device *dev, + struct generic_pm_domain_data *gpd_data) +{ + spin_lock_irq(&dev->power.lock); + + dev->pm_domain = NULL; + dev->power.subsys_data->domain_data = NULL; + + spin_unlock_irq(&dev->power.lock); + + kfree(gpd_data); + dev_pm_put_subsys_data(dev); +} + +/** + * __pm_genpd_add_device - Add a device to an I/O PM domain. + * @genpd: PM domain to add the device to. + * @dev: Device to be added. + * @td: Set of PM QoS timing parameters to attach to the device. + */ +int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, + struct gpd_timing_data *td) +{ + struct generic_pm_domain_data *gpd_data; + int ret = 0; + + dev_dbg(dev, "%s()\n", __func__); + + if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) + return -EINVAL; + + gpd_data = genpd_alloc_dev_data(dev, genpd, td); + if (IS_ERR(gpd_data)) + return PTR_ERR(gpd_data); + + genpd_acquire_lock(genpd); + + if (genpd->prepared_count > 0) { + ret = -EAGAIN; + goto out; + } + + ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0; + if (ret) + goto out; + + genpd->device_count++; + genpd->max_off_time_changed = true; + + list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); + + out: + genpd_release_lock(genpd); + + if (ret) + genpd_free_dev_data(dev, gpd_data); + else + dev_pm_qos_add_notifier(dev, &gpd_data->nb); + + return ret; +} + +/** + * __pm_genpd_name_add_device - Find I/O PM domain and add a device to it. + * @domain_name: Name of the PM domain to add the device to. + * @dev: Device to be added. + * @td: Set of PM QoS timing parameters to attach to the device. + */ +int __pm_genpd_name_add_device(const char *domain_name, struct device *dev, + struct gpd_timing_data *td) +{ + return __pm_genpd_add_device(pm_genpd_lookup_name(domain_name), dev, td); +} + +/** + * pm_genpd_remove_device - Remove a device from an I/O PM domain. + * @genpd: PM domain to remove the device from. + * @dev: Device to be removed. + */ +int pm_genpd_remove_device(struct generic_pm_domain *genpd, + struct device *dev) +{ + struct generic_pm_domain_data *gpd_data; + struct pm_domain_data *pdd; + int ret = 0; + + dev_dbg(dev, "%s()\n", __func__); + + if (!genpd || genpd != pm_genpd_lookup_dev(dev)) + return -EINVAL; + + /* The above validation also means we have existing domain_data. */ + pdd = dev->power.subsys_data->domain_data; + gpd_data = to_gpd_data(pdd); + dev_pm_qos_remove_notifier(dev, &gpd_data->nb); + + genpd_acquire_lock(genpd); + + if (genpd->prepared_count > 0) { + ret = -EAGAIN; + goto out; + } + + genpd->device_count--; + genpd->max_off_time_changed = true; + + if (genpd->detach_dev) + genpd->detach_dev(genpd, dev); + + list_del_init(&pdd->list_node); + + genpd_release_lock(genpd); + + genpd_free_dev_data(dev, gpd_data); + + return 0; + + out: + genpd_release_lock(genpd); + dev_pm_qos_add_notifier(dev, &gpd_data->nb); + + return ret; +} + +/** + * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain. + * @genpd: Master PM domain to add the subdomain to. + * @subdomain: Subdomain to be added. + */ +int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, + struct generic_pm_domain *subdomain) +{ + struct gpd_link *link; + int ret = 0; + + if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain) + || genpd == subdomain) + return -EINVAL; + + start: + genpd_acquire_lock(genpd); + mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING); + + if (subdomain->status != GPD_STATE_POWER_OFF + && subdomain->status != GPD_STATE_ACTIVE) { + mutex_unlock(&subdomain->lock); + genpd_release_lock(genpd); + goto start; + } + + if (genpd->status == GPD_STATE_POWER_OFF + && subdomain->status != GPD_STATE_POWER_OFF) { + ret = -EINVAL; + goto out; + } + + list_for_each_entry(link, &genpd->master_links, master_node) { + if (link->slave == subdomain && link->master == genpd) { + ret = -EINVAL; + goto out; + } + } + + link = kzalloc(sizeof(*link), GFP_KERNEL); + if (!link) { + ret = -ENOMEM; + goto out; + } + link->master = genpd; + list_add_tail(&link->master_node, &genpd->master_links); + link->slave = subdomain; + list_add_tail(&link->slave_node, &subdomain->slave_links); + if (subdomain->status != GPD_STATE_POWER_OFF) + genpd_sd_counter_inc(genpd); + + out: + mutex_unlock(&subdomain->lock); + genpd_release_lock(genpd); + + return ret; +} + +/** + * pm_genpd_add_subdomain_names - Add a subdomain to an I/O PM domain. + * @master_name: Name of the master PM domain to add the subdomain to. + * @subdomain_name: Name of the subdomain to be added. + */ +int pm_genpd_add_subdomain_names(const char *master_name, + const char *subdomain_name) +{ + struct generic_pm_domain *master = NULL, *subdomain = NULL, *gpd; + + if (IS_ERR_OR_NULL(master_name) || IS_ERR_OR_NULL(subdomain_name)) + return -EINVAL; + + mutex_lock(&gpd_list_lock); + list_for_each_entry(gpd, &gpd_list, gpd_list_node) { + if (!master && !strcmp(gpd->name, master_name)) + master = gpd; + + if (!subdomain && !strcmp(gpd->name, subdomain_name)) + subdomain = gpd; + + if (master && subdomain) + break; + } + mutex_unlock(&gpd_list_lock); + + return pm_genpd_add_subdomain(master, subdomain); +} + +/** + * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain. + * @genpd: Master PM domain to remove the subdomain from. + * @subdomain: Subdomain to be removed. + */ +int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, + struct generic_pm_domain *subdomain) +{ + struct gpd_link *link; + int ret = -EINVAL; + + if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)) + return -EINVAL; + + start: + genpd_acquire_lock(genpd); + + list_for_each_entry(link, &genpd->master_links, master_node) { + if (link->slave != subdomain) + continue; + + mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING); + + if (subdomain->status != GPD_STATE_POWER_OFF + && subdomain->status != GPD_STATE_ACTIVE) { + mutex_unlock(&subdomain->lock); + genpd_release_lock(genpd); + goto start; + } + + list_del(&link->master_node); + list_del(&link->slave_node); + kfree(link); + if (subdomain->status != GPD_STATE_POWER_OFF) + genpd_sd_counter_dec(genpd); + + mutex_unlock(&subdomain->lock); + + ret = 0; + break; + } + + genpd_release_lock(genpd); + + return ret; +} + +/** + * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle. + * @genpd: PM domain to be connected with cpuidle. + * @state: cpuidle state this domain can disable/enable. + * + * Make a PM domain behave as though it contained a CPU core, that is, instead + * of calling its power down routine it will enable the given cpuidle state so + * that the cpuidle subsystem can power it down (if possible and desirable). + */ +int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state) +{ + struct cpuidle_driver *cpuidle_drv; + struct gpd_cpuidle_data *cpuidle_data; + struct cpuidle_state *idle_state; + int ret = 0; + + if (IS_ERR_OR_NULL(genpd) || state < 0) + return -EINVAL; + + genpd_acquire_lock(genpd); + + if (genpd->cpuidle_data) { + ret = -EEXIST; + goto out; + } + cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL); + if (!cpuidle_data) { + ret = -ENOMEM; + goto out; + } + cpuidle_drv = cpuidle_driver_ref(); + if (!cpuidle_drv) { + ret = -ENODEV; + goto err_drv; + } + if (cpuidle_drv->state_count <= state) { + ret = -EINVAL; + goto err; + } + idle_state = &cpuidle_drv->states[state]; + if (!idle_state->disabled) { + ret = -EAGAIN; + goto err; + } + cpuidle_data->idle_state = idle_state; + cpuidle_data->saved_exit_latency = idle_state->exit_latency; + genpd->cpuidle_data = cpuidle_data; + genpd_recalc_cpu_exit_latency(genpd); + + out: + genpd_release_lock(genpd); + return ret; + + err: + cpuidle_driver_unref(); + + err_drv: + kfree(cpuidle_data); + goto out; +} + +/** + * pm_genpd_name_attach_cpuidle - Find PM domain and connect cpuidle to it. + * @name: Name of the domain to connect to cpuidle. + * @state: cpuidle state this domain can manipulate. + */ +int pm_genpd_name_attach_cpuidle(const char *name, int state) +{ + return pm_genpd_attach_cpuidle(pm_genpd_lookup_name(name), state); +} + +/** + * pm_genpd_detach_cpuidle - Remove the cpuidle connection from a PM domain. + * @genpd: PM domain to remove the cpuidle connection from. + * + * Remove the cpuidle connection set up by pm_genpd_attach_cpuidle() from the + * given PM domain. + */ +int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd) +{ + struct gpd_cpuidle_data *cpuidle_data; + struct cpuidle_state *idle_state; + int ret = 0; + + if (IS_ERR_OR_NULL(genpd)) + return -EINVAL; + + genpd_acquire_lock(genpd); + + cpuidle_data = genpd->cpuidle_data; + if (!cpuidle_data) { + ret = -ENODEV; + goto out; + } + idle_state = cpuidle_data->idle_state; + if (!idle_state->disabled) { + ret = -EAGAIN; + goto out; + } + idle_state->exit_latency = cpuidle_data->saved_exit_latency; + cpuidle_driver_unref(); + genpd->cpuidle_data = NULL; + kfree(cpuidle_data); + + out: + genpd_release_lock(genpd); + return ret; +} + +/** + * pm_genpd_name_detach_cpuidle - Find PM domain and disconnect cpuidle from it. + * @name: Name of the domain to disconnect cpuidle from. + */ +int pm_genpd_name_detach_cpuidle(const char *name) +{ + return pm_genpd_detach_cpuidle(pm_genpd_lookup_name(name)); +} + +/* Default device callbacks for generic PM domains. */ + +/** + * pm_genpd_default_save_state - Default "save device state" for PM domains. + * @dev: Device to handle. + */ +static int pm_genpd_default_save_state(struct device *dev) +{ + int (*cb)(struct device *__dev); + + if (dev->type && dev->type->pm) + cb = dev->type->pm->runtime_suspend; + else if (dev->class && dev->class->pm) + cb = dev->class->pm->runtime_suspend; + else if (dev->bus && dev->bus->pm) + cb = dev->bus->pm->runtime_suspend; + else + cb = NULL; + + if (!cb && dev->driver && dev->driver->pm) + cb = dev->driver->pm->runtime_suspend; + + return cb ? cb(dev) : 0; +} + +/** + * pm_genpd_default_restore_state - Default PM domains "restore device state". + * @dev: Device to handle. + */ +static int pm_genpd_default_restore_state(struct device *dev) +{ + int (*cb)(struct device *__dev); + + if (dev->type && dev->type->pm) + cb = dev->type->pm->runtime_resume; + else if (dev->class && dev->class->pm) + cb = dev->class->pm->runtime_resume; + else if (dev->bus && dev->bus->pm) + cb = dev->bus->pm->runtime_resume; + else + cb = NULL; + + if (!cb && dev->driver && dev->driver->pm) + cb = dev->driver->pm->runtime_resume; + + return cb ? cb(dev) : 0; +} + +/** + * pm_genpd_init - Initialize a generic I/O PM domain object. + * @genpd: PM domain object to initialize. + * @gov: PM domain governor to associate with the domain (may be NULL). + * @is_off: Initial value of the domain's power_is_off field. + */ +void pm_genpd_init(struct generic_pm_domain *genpd, + struct dev_power_governor *gov, bool is_off) +{ + if (IS_ERR_OR_NULL(genpd)) + return; + + INIT_LIST_HEAD(&genpd->master_links); + INIT_LIST_HEAD(&genpd->slave_links); + INIT_LIST_HEAD(&genpd->dev_list); + mutex_init(&genpd->lock); + genpd->gov = gov; + INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn); + genpd->in_progress = 0; + atomic_set(&genpd->sd_count, 0); + genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE; + init_waitqueue_head(&genpd->status_wait_queue); + genpd->poweroff_task = NULL; + genpd->resume_count = 0; + genpd->device_count = 0; + genpd->max_off_time_ns = -1; + genpd->max_off_time_changed = true; + genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; + genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume; + genpd->domain.ops.prepare = pm_genpd_prepare; + genpd->domain.ops.suspend = pm_genpd_suspend; + genpd->domain.ops.suspend_late = pm_genpd_suspend_late; + genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq; + genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq; + genpd->domain.ops.resume_early = pm_genpd_resume_early; + genpd->domain.ops.resume = pm_genpd_resume; + genpd->domain.ops.freeze = pm_genpd_freeze; + genpd->domain.ops.freeze_late = pm_genpd_freeze_late; + genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq; + genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq; + genpd->domain.ops.thaw_early = pm_genpd_thaw_early; + genpd->domain.ops.thaw = pm_genpd_thaw; + genpd->domain.ops.poweroff = pm_genpd_suspend; + genpd->domain.ops.poweroff_late = pm_genpd_suspend_late; + genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq; + genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq; + genpd->domain.ops.restore_early = pm_genpd_resume_early; + genpd->domain.ops.restore = pm_genpd_resume; + genpd->domain.ops.complete = pm_genpd_complete; + genpd->dev_ops.save_state = pm_genpd_default_save_state; + genpd->dev_ops.restore_state = pm_genpd_default_restore_state; + + if (genpd->flags & GENPD_FLAG_PM_CLK) { + genpd->dev_ops.stop = pm_clk_suspend; + genpd->dev_ops.start = pm_clk_resume; + } + + mutex_lock(&gpd_list_lock); + list_add(&genpd->gpd_list_node, &gpd_list); + mutex_unlock(&gpd_list_lock); +} + +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF +/* + * Device Tree based PM domain providers. + * + * The code below implements generic device tree based PM domain providers that + * bind device tree nodes with generic PM domains registered in the system. + * + * Any driver that registers generic PM domains and needs to support binding of + * devices to these domains is supposed to register a PM domain provider, which + * maps a PM domain specifier retrieved from the device tree to a PM domain. + * + * Two simple mapping functions have been provided for convenience: + * - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping. + * - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by + * index. + */ + +/** + * struct of_genpd_provider - PM domain provider registration structure + * @link: Entry in global list of PM domain providers + * @node: Pointer to device tree node of PM domain provider + * @xlate: Provider-specific xlate callback mapping a set of specifier cells + * into a PM domain. + * @data: context pointer to be passed into @xlate callback + */ +struct of_genpd_provider { + struct list_head link; + struct device_node *node; + genpd_xlate_t xlate; + void *data; +}; + +/* List of registered PM domain providers. */ +static LIST_HEAD(of_genpd_providers); +/* Mutex to protect the list above. */ +static DEFINE_MUTEX(of_genpd_mutex); + +/** + * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping + * @genpdspec: OF phandle args to map into a PM domain + * @data: xlate function private data - pointer to struct generic_pm_domain + * + * This is a generic xlate function that can be used to model PM domains that + * have their own device tree nodes. The private data of xlate function needs + * to be a valid pointer to struct generic_pm_domain. + */ +struct generic_pm_domain *__of_genpd_xlate_simple( + struct of_phandle_args *genpdspec, + void *data) +{ + if (genpdspec->args_count != 0) + return ERR_PTR(-EINVAL); + return data; +} +EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple); + +/** + * __of_genpd_xlate_onecell() - Xlate function using a single index. + * @genpdspec: OF phandle args to map into a PM domain + * @data: xlate function private data - pointer to struct genpd_onecell_data + * + * This is a generic xlate function that can be used to model simple PM domain + * controllers that have one device tree node and provide multiple PM domains. + * A single cell is used as an index into an array of PM domains specified in + * the genpd_onecell_data struct when registering the provider. + */ +struct generic_pm_domain *__of_genpd_xlate_onecell( + struct of_phandle_args *genpdspec, + void *data) +{ + struct genpd_onecell_data *genpd_data = data; + unsigned int idx = genpdspec->args[0]; + + if (genpdspec->args_count != 1) + return ERR_PTR(-EINVAL); + + if (idx >= genpd_data->num_domains) { + pr_err("%s: invalid domain index %u\n", __func__, idx); + return ERR_PTR(-EINVAL); + } + + if (!genpd_data->domains[idx]) + return ERR_PTR(-ENOENT); + + return genpd_data->domains[idx]; +} +EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell); + +/** + * __of_genpd_add_provider() - Register a PM domain provider for a node + * @np: Device node pointer associated with the PM domain provider. + * @xlate: Callback for decoding PM domain from phandle arguments. + * @data: Context pointer for @xlate callback. + */ +int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate, + void *data) +{ + struct of_genpd_provider *cp; + + cp = kzalloc(sizeof(*cp), GFP_KERNEL); + if (!cp) + return -ENOMEM; + + cp->node = of_node_get(np); + cp->data = data; + cp->xlate = xlate; + + mutex_lock(&of_genpd_mutex); + list_add(&cp->link, &of_genpd_providers); + mutex_unlock(&of_genpd_mutex); + pr_debug("Added domain provider from %s\n", np->full_name); + + return 0; +} +EXPORT_SYMBOL_GPL(__of_genpd_add_provider); + +/** + * of_genpd_del_provider() - Remove a previously registered PM domain provider + * @np: Device node pointer associated with the PM domain provider + */ +void of_genpd_del_provider(struct device_node *np) +{ + struct of_genpd_provider *cp; + + mutex_lock(&of_genpd_mutex); + list_for_each_entry(cp, &of_genpd_providers, link) { + if (cp->node == np) { + list_del(&cp->link); + of_node_put(cp->node); + kfree(cp); + break; + } + } + mutex_unlock(&of_genpd_mutex); +} +EXPORT_SYMBOL_GPL(of_genpd_del_provider); + +/** + * of_genpd_get_from_provider() - Look-up PM domain + * @genpdspec: OF phandle args to use for look-up + * + * Looks for a PM domain provider under the node specified by @genpdspec and if + * found, uses xlate function of the provider to map phandle args to a PM + * domain. + * + * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR() + * on failure. + */ +struct generic_pm_domain *of_genpd_get_from_provider( + struct of_phandle_args *genpdspec) +{ + struct generic_pm_domain *genpd = ERR_PTR(-ENOENT); + struct of_genpd_provider *provider; + + mutex_lock(&of_genpd_mutex); + + /* Check if we have such a provider in our array */ + list_for_each_entry(provider, &of_genpd_providers, link) { + if (provider->node == genpdspec->np) + genpd = provider->xlate(genpdspec, provider->data); + if (!IS_ERR(genpd)) + break; + } + + mutex_unlock(&of_genpd_mutex); + + return genpd; +} +EXPORT_SYMBOL_GPL(of_genpd_get_from_provider); + +/** + * genpd_dev_pm_detach - Detach a device from its PM domain. + * @dev: Device to attach. + * @power_off: Currently not used + * + * Try to locate a corresponding generic PM domain, which the device was + * attached to previously. If such is found, the device is detached from it. + */ +static void genpd_dev_pm_detach(struct device *dev, bool power_off) +{ + struct generic_pm_domain *pd; + int ret = 0; + + pd = pm_genpd_lookup_dev(dev); + if (!pd) + return; + + dev_dbg(dev, "removing from PM domain %s\n", pd->name); + + while (1) { + ret = pm_genpd_remove_device(pd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } + + if (ret < 0) { + dev_err(dev, "failed to remove from PM domain %s: %d", + pd->name, ret); + return; + } + + /* Check if PM domain can be powered off after removing this device. */ + genpd_queue_power_off_work(pd); +} + +static void genpd_dev_pm_sync(struct device *dev) +{ + struct generic_pm_domain *pd; + + pd = dev_to_genpd(dev); + if (IS_ERR(pd)) + return; + + genpd_queue_power_off_work(pd); +} + +/** + * genpd_dev_pm_attach - Attach a device to its PM domain using DT. + * @dev: Device to attach. + * + * Parse device's OF node to find a PM domain specifier. If such is found, + * attaches the device to retrieved pm_domain ops. + * + * Both generic and legacy Samsung-specific DT bindings are supported to keep + * backwards compatibility with existing DTBs. + * + * Returns 0 on successfully attached PM domain or negative error code. + */ +int genpd_dev_pm_attach(struct device *dev) +{ + struct of_phandle_args pd_args; + struct generic_pm_domain *pd; + int ret; + + if (!dev->of_node) + return -ENODEV; + + if (dev->pm_domain) + return -EEXIST; + + ret = of_parse_phandle_with_args(dev->of_node, "power-domains", + "#power-domain-cells", 0, &pd_args); + if (ret < 0) { + if (ret != -ENOENT) + return ret; + + /* + * Try legacy Samsung-specific bindings + * (for backwards compatibility of DT ABI) + */ + pd_args.args_count = 0; + pd_args.np = of_parse_phandle(dev->of_node, + "samsung,power-domain", 0); + if (!pd_args.np) + return -ENOENT; + } + + pd = of_genpd_get_from_provider(&pd_args); + if (IS_ERR(pd)) { + dev_dbg(dev, "%s() failed to find PM domain: %ld\n", + __func__, PTR_ERR(pd)); + of_node_put(dev->of_node); + return PTR_ERR(pd); + } + + dev_dbg(dev, "adding to PM domain %s\n", pd->name); + + while (1) { + ret = pm_genpd_add_device(pd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } + + if (ret < 0) { + dev_err(dev, "failed to add to PM domain %s: %d", + pd->name, ret); + of_node_put(dev->of_node); + return ret; + } + + dev->pm_domain->detach = genpd_dev_pm_detach; + dev->pm_domain->sync = genpd_dev_pm_sync; + pm_genpd_poweron(pd); + + return 0; +} +EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); +#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */ + + +/*** debugfs support ***/ + +#ifdef CONFIG_PM_ADVANCED_DEBUG +#include <linux/pm.h> +#include <linux/device.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <linux/init.h> +#include <linux/kobject.h> +static struct dentry *pm_genpd_debugfs_dir; + +/* + * TODO: This function is a slightly modified version of rtpm_status_show + * from sysfs.c, so generalize it. + */ +static void rtpm_status_str(struct seq_file *s, struct device *dev) +{ + static const char * const status_lookup[] = { + [RPM_ACTIVE] = "active", + [RPM_RESUMING] = "resuming", + [RPM_SUSPENDED] = "suspended", + [RPM_SUSPENDING] = "suspending" + }; + const char *p = ""; + + if (dev->power.runtime_error) + p = "error"; + else if (dev->power.disable_depth) + p = "unsupported"; + else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup)) + p = status_lookup[dev->power.runtime_status]; + else + WARN_ON(1); + + seq_puts(s, p); +} + +static int pm_genpd_summary_one(struct seq_file *s, + struct generic_pm_domain *genpd) +{ + static const char * const status_lookup[] = { + [GPD_STATE_ACTIVE] = "on", + [GPD_STATE_WAIT_MASTER] = "wait-master", + [GPD_STATE_BUSY] = "busy", + [GPD_STATE_REPEAT] = "off-in-progress", + [GPD_STATE_POWER_OFF] = "off" + }; + struct pm_domain_data *pm_data; + const char *kobj_path; + struct gpd_link *link; + int ret; + + ret = mutex_lock_interruptible(&genpd->lock); + if (ret) + return -ERESTARTSYS; + + if (WARN_ON(genpd->status >= ARRAY_SIZE(status_lookup))) + goto exit; + seq_printf(s, "%-30s %-15s ", genpd->name, status_lookup[genpd->status]); + + /* + * Modifications on the list require holding locks on both + * master and slave, so we are safe. + * Also genpd->name is immutable. + */ + list_for_each_entry(link, &genpd->master_links, master_node) { + seq_printf(s, "%s", link->slave->name); + if (!list_is_last(&link->master_node, &genpd->master_links)) + seq_puts(s, ", "); + } + + list_for_each_entry(pm_data, &genpd->dev_list, list_node) { + kobj_path = kobject_get_path(&pm_data->dev->kobj, GFP_KERNEL); + if (kobj_path == NULL) + continue; + + seq_printf(s, "\n %-50s ", kobj_path); + rtpm_status_str(s, pm_data->dev); + kfree(kobj_path); + } + + seq_puts(s, "\n"); +exit: + mutex_unlock(&genpd->lock); + + return 0; +} + +static int pm_genpd_summary_show(struct seq_file *s, void *data) +{ + struct generic_pm_domain *genpd; + int ret = 0; + + seq_puts(s, " domain status slaves\n"); + seq_puts(s, " /device runtime status\n"); + seq_puts(s, "----------------------------------------------------------------------\n"); + + ret = mutex_lock_interruptible(&gpd_list_lock); + if (ret) + return -ERESTARTSYS; + + list_for_each_entry(genpd, &gpd_list, gpd_list_node) { + ret = pm_genpd_summary_one(s, genpd); + if (ret) + break; + } + mutex_unlock(&gpd_list_lock); + + return ret; +} + +static int pm_genpd_summary_open(struct inode *inode, struct file *file) +{ + return single_open(file, pm_genpd_summary_show, NULL); +} + +static const struct file_operations pm_genpd_summary_fops = { + .open = pm_genpd_summary_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init pm_genpd_debug_init(void) +{ + struct dentry *d; + + pm_genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL); + + if (!pm_genpd_debugfs_dir) + return -ENOMEM; + + d = debugfs_create_file("pm_genpd_summary", S_IRUGO, + pm_genpd_debugfs_dir, NULL, &pm_genpd_summary_fops); + if (!d) + return -ENOMEM; + + return 0; +} +late_initcall(pm_genpd_debug_init); + +static void __exit pm_genpd_debug_exit(void) +{ + debugfs_remove_recursive(pm_genpd_debugfs_dir); +} +__exitcall(pm_genpd_debug_exit); +#endif /* CONFIG_PM_ADVANCED_DEBUG */ |