From 0b589741b8b83a33e25fb32bb714ea1b972af5aa Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rjw@sisk.pl> Date: Sat, 16 Jun 2012 00:02:22 +0200 Subject: PM / Domains: Use subsystem runtime suspend/resume callbacks by default Currently, the default "save state" and "restore state" routines for generic PM domains, pm_genpd_default_save_state() and pm_genpd_default_restore_state(), respectively, only use runtime PM callbacks provided by device drivers, but in general those callbacks need not provide the entire necessary functionality. Namely, in general it may be necessary to execute subsystem (i.e. device type, device class or bus type) callbacks that will carry out all of the necessary operations. For this reason, modify pm_genpd_default_save_state() and pm_genpd_default_restore_state() to execute subsystem callbacks, if they are provided, and fall back to driver callbacks otherwise. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 83aa694a8efe..49fdd4002b9f 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1615,16 +1615,24 @@ EXPORT_SYMBOL_GPL(__pm_genpd_remove_callbacks); static int pm_genpd_default_save_state(struct device *dev) { int (*cb)(struct device *__dev); - struct device_driver *drv = dev->driver; cb = dev_gpd_data(dev)->ops.save_state; if (cb) return cb(dev); - if (drv && drv->pm && drv->pm->runtime_suspend) - return drv->pm->runtime_suspend(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; - return 0; + if (!cb && dev->driver && dev->driver->pm) + cb = dev->driver->pm->runtime_suspend; + + return cb ? cb(dev) : 0; } /** @@ -1634,16 +1642,24 @@ static int pm_genpd_default_save_state(struct device *dev) static int pm_genpd_default_restore_state(struct device *dev) { int (*cb)(struct device *__dev); - struct device_driver *drv = dev->driver; cb = dev_gpd_data(dev)->ops.restore_state; if (cb) return cb(dev); - if (drv && drv->pm && drv->pm->runtime_resume) - return drv->pm->runtime_resume(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; - return 0; + if (!cb && dev->driver && dev->driver->pm) + cb = dev->driver->pm->runtime_resume; + + return cb ? cb(dev) : 0; } #ifdef CONFIG_PM_SLEEP -- cgit v1.2.3 From 80de3d7f416f1accd03f2e519ead32d6fde4fcf4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rjw@sisk.pl> Date: Sat, 16 Jun 2012 00:02:34 +0200 Subject: PM / Domains: Do not stop devices after restoring their states While resuming a device belonging to a PM domain, pm_genpd_runtime_resume() calls __pm_genpd_restore_device() to restore its state, if necessary. The latter starts the device, using genpd_start_dev(), restores its state, using genpd_restore_dev(), and then stops it, using genpd_stop_dev(). However, this last operation is not necessary, because the device is supposed to be operational after pm_genpd_runtime_resume() has returned and because of it pm_genpd_runtime_resume() has to call genpd_start_dev() once again for the "restored" device, which is inefficient. To make things more efficient, remove the call to genpd_stop_dev() from __pm_genpd_restore_device() and the direct call to genpd_start_dev() from pm_genpd_runtime_resume(). [Of course, genpd_start_dev() still has to be called by it for devices with the power.irq_safe flag set, because __pm_genpd_restore_device() is not executed for them.] This change has been tested on the SH7372 Mackerel board. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 49fdd4002b9f..da1d52576ec9 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -339,19 +339,16 @@ static void __pm_genpd_restore_device(struct pm_domain_data *pdd, { struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); struct device *dev = pdd->dev; + bool need_restore = gpd_data->need_restore; - if (!gpd_data->need_restore) - return; - + gpd_data->need_restore = false; mutex_unlock(&genpd->lock); genpd_start_dev(genpd, dev); - genpd_restore_dev(genpd, dev); - genpd_stop_dev(genpd, dev); + if (need_restore) + genpd_restore_dev(genpd, dev); mutex_lock(&genpd->lock); - - gpd_data->need_restore = false; } /** @@ -595,7 +592,7 @@ static int pm_genpd_runtime_resume(struct device *dev) /* If power.irq_safe, the PM domain is never powered off. */ if (dev->power.irq_safe) - goto out; + return genpd_start_dev(genpd, dev); mutex_lock(&genpd->lock); ret = __pm_genpd_poweron(genpd); @@ -628,9 +625,6 @@ static int pm_genpd_runtime_resume(struct device *dev) wake_up_all(&genpd->status_wait_queue); mutex_unlock(&genpd->lock); - out: - genpd_start_dev(genpd, dev); - return 0; } -- cgit v1.2.3 From cbc9ef0287ab764d3da0129efa673808df641fe3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rjw@sisk.pl> Date: Tue, 3 Jul 2012 19:07:42 +0200 Subject: PM / Domains: Add preliminary support for cpuidle, v2 On some systems there are CPU cores located in the same power domains as I/O devices. Then, power can only be removed from the domain if all I/O devices in it are not in use and the CPU core is idle. Add preliminary support for that to the generic PM domains framework. First, the platform is expected to provide a cpuidle driver with one extra state designated for use with the generic PM domains code. This state should be initially disabled and its exit_latency value should be set to whatever time is needed to bring up the CPU core itself after restoring power to it, not including the domain's power on latency. Its .enter() callback should point to a procedure that will remove power from the domain containing the CPU core at the end of the CPU power transition. The remaining characteristics of the extra cpuidle state, referred to as the "domain" cpuidle state below, (e.g. power usage, target residency) should be populated in accordance with the properties of the hardware. Next, the platform should execute genpd_attach_cpuidle() on the PM domain containing the CPU core. That will cause the generic PM domains framework to treat that domain in a special way such that: * When all devices in the domain have been suspended and it is about to be turned off, the states of the devices will be saved, but power will not be removed from the domain. Instead, the "domain" cpuidle state will be enabled so that power can be removed from the domain when the CPU core is idle and the state has been chosen as the target by the cpuidle governor. * When the first I/O device in the domain is resumed and __pm_genpd_poweron(() is called for the first time after power has been removed from the domain, the "domain" cpuidle state will be disabled to avoid subsequent surprise power removals via cpuidle. The effective exit_latency value of the "domain" cpuidle state depends on the time needed to bring up the CPU core itself after restoring power to it as well as on the power on latency of the domain containing the CPU core. Thus the "domain" cpuidle state's exit_latency has to be recomputed every time the domain's power on latency is updated, which may happen every time power is restored to the domain, if the measured power on latency is greater than the latency stored in the corresponding generic_pm_domain structure. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com> --- drivers/base/power/domain.c | 117 +++++++++++++++++++++++++++++++++++++++ drivers/cpuidle/cpuidle.c | 1 + drivers/cpuidle/governors/menu.c | 3 +- include/linux/cpuidle.h | 1 + include/linux/pm_domain.h | 17 ++++++ 5 files changed, 138 insertions(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index da1d52576ec9..4b5f090fccb6 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -139,6 +139,19 @@ static void genpd_set_active(struct generic_pm_domain *genpd) genpd->status = GPD_STATE_ACTIVE; } +static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd) +{ + s64 usecs64; + + if (!genpd->cpu_data) + return; + + usecs64 = genpd->power_on_latency_ns; + do_div(usecs64, NSEC_PER_USEC); + usecs64 += genpd->cpu_data->saved_exit_latency; + genpd->cpu_data->idle_state->exit_latency = usecs64; +} + /** * __pm_genpd_poweron - Restore power to a given PM domain and its masters. * @genpd: PM domain to power up. @@ -176,6 +189,13 @@ int __pm_genpd_poweron(struct generic_pm_domain *genpd) return 0; } + if (genpd->cpu_data) { + cpuidle_pause_and_lock(); + genpd->cpu_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 @@ -215,6 +235,7 @@ int __pm_genpd_poweron(struct generic_pm_domain *genpd) if (elapsed_ns > genpd->power_on_latency_ns) { genpd->power_on_latency_ns = elapsed_ns; genpd->max_off_time_changed = true; + genpd_recalc_cpu_exit_latency(genpd); if (genpd->name) pr_warning("%s: Power-on latency exceeded, " "new value %lld ns\n", genpd->name, @@ -222,6 +243,7 @@ int __pm_genpd_poweron(struct generic_pm_domain *genpd) } } + out: genpd_set_active(genpd); return 0; @@ -455,6 +477,21 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) } } + if (genpd->cpu_data) { + /* + * If cpu_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->cpu_data->idle_state->disabled = false; + cpuidle_resume_and_unlock(); + goto out; + } + if (genpd->power_off) { ktime_t time_start; s64 elapsed_ns; @@ -1600,6 +1637,86 @@ int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td) } EXPORT_SYMBOL_GPL(__pm_genpd_remove_callbacks); +int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state) +{ + struct cpuidle_driver *cpuidle_drv; + struct gpd_cpu_data *cpu_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->cpu_data) { + ret = -EEXIST; + goto out; + } + cpu_data = kzalloc(sizeof(*cpu_data), GFP_KERNEL); + if (!cpu_data) { + ret = -ENOMEM; + goto out; + } + cpuidle_drv = cpuidle_driver_ref(); + if (!cpuidle_drv) { + ret = -ENODEV; + goto out; + } + if (cpuidle_drv->state_count <= state) { + ret = -EINVAL; + goto err; + } + idle_state = &cpuidle_drv->states[state]; + if (!idle_state->disabled) { + ret = -EAGAIN; + goto err; + } + cpu_data->idle_state = idle_state; + cpu_data->saved_exit_latency = idle_state->exit_latency; + genpd->cpu_data = cpu_data; + genpd_recalc_cpu_exit_latency(genpd); + + out: + genpd_release_lock(genpd); + return ret; + + err: + cpuidle_driver_unref(); + goto out; +} + +int genpd_detach_cpuidle(struct generic_pm_domain *genpd) +{ + struct gpd_cpu_data *cpu_data; + struct cpuidle_state *idle_state; + int ret = 0; + + if (IS_ERR_OR_NULL(genpd)) + return -EINVAL; + + genpd_acquire_lock(genpd); + + cpu_data = genpd->cpu_data; + if (!cpu_data) { + ret = -ENODEV; + goto out; + } + idle_state = cpu_data->idle_state; + if (!idle_state->disabled) { + ret = -EAGAIN; + goto out; + } + idle_state->exit_latency = cpu_data->saved_exit_latency; + cpuidle_driver_unref(); + genpd->cpu_data = NULL; + kfree(cpu_data); + + out: + genpd_release_lock(genpd); + return ret; +} + /* Default device callbacks for generic PM domains. */ /** diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 04e4b7674a47..0132706251df 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -265,6 +265,7 @@ static void poll_idle_init(struct cpuidle_driver *drv) state->power_usage = -1; state->flags = 0; state->enter = poll_idle; + state->disabled = false; } #else static void poll_idle_init(struct cpuidle_driver *drv) {} diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 8391d93f57d5..5b1f2c372c1f 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -281,6 +281,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) * unless the timer is happening really really soon. */ if (data->expected_us > 5 && + !drv->states[CPUIDLE_DRIVER_STATE_START].disabled && dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0) data->last_state_idx = CPUIDLE_DRIVER_STATE_START; @@ -292,7 +293,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) struct cpuidle_state *s = &drv->states[i]; struct cpuidle_state_usage *su = &dev->states_usage[i]; - if (su->disable) + if (s->disabled || su->disable) continue; if (s->target_residency > data->predicted_us) continue; diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 27cfced7b57b..8684a0d07b87 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -47,6 +47,7 @@ struct cpuidle_state { unsigned int exit_latency; /* in US */ int power_usage; /* in mW */ unsigned int target_residency; /* in US */ + bool disabled; /* disabled on all CPUs */ int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 30f794eb3826..2febe31d2675 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -15,6 +15,7 @@ #include <linux/err.h> #include <linux/of.h> #include <linux/notifier.h> +#include <linux/cpuidle.h> enum gpd_status { GPD_STATE_ACTIVE = 0, /* PM domain is active */ @@ -45,6 +46,11 @@ struct gpd_dev_ops { bool (*active_wakeup)(struct device *dev); }; +struct gpd_cpu_data { + unsigned int saved_exit_latency; + struct cpuidle_state *idle_state; +}; + struct generic_pm_domain { struct dev_pm_domain domain; /* PM domain operations */ struct list_head gpd_list_node; /* Node in the global PM domains list */ @@ -75,6 +81,7 @@ struct generic_pm_domain { bool max_off_time_changed; bool cached_power_down_ok; struct device_node *of_node; /* Node in device tree */ + struct gpd_cpu_data *cpu_data; }; static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd) @@ -155,6 +162,8 @@ extern int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops, struct gpd_timing_data *td); extern int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td); +extern int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state); +extern int genpd_detach_cpuidle(struct generic_pm_domain *genpd); extern void pm_genpd_init(struct generic_pm_domain *genpd, struct dev_power_governor *gov, bool is_off); @@ -211,6 +220,14 @@ static inline int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td) { return -ENOSYS; } +static inline int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int st) +{ + return -ENOSYS; +} +static inline int genpd_detach_cpuidle(struct generic_pm_domain *genpd) +{ + return -ENOSYS; +} static inline void pm_genpd_init(struct generic_pm_domain *genpd, struct dev_power_governor *gov, bool is_off) { -- cgit v1.2.3 From 1d5fcfec22ce5f69db0d29284d2b65ff8ab1bfaa Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rjw@sisk.pl> Date: Thu, 5 Jul 2012 22:12:32 +0200 Subject: PM / Domains: Add device domain data reference counter Add a mechanism for counting references to the struct generic_pm_domain_data object pointed to by dev->power.subsys_data->domain_data if the device in question belongs to a generic PM domain. This change is necessary for a subsequent patch making it possible to allocate that object from within pm_genpd_add_callbacks(), so that drivers can attach their PM domain device callbacks to devices before those devices are added to PM domains. This patch has been tested on the SH7372 Mackerel board. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 83 +++++++++++++++++++++++++++++++-------------- include/linux/pm_domain.h | 1 + 2 files changed, 58 insertions(+), 26 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 4b5f090fccb6..45eb3b155b6d 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -297,7 +297,7 @@ static int genpd_dev_pm_qos_notifier(struct notifier_block *nb, pdd = dev->power.subsys_data ? dev->power.subsys_data->domain_data : NULL; - if (pdd) { + if (pdd && pdd->dev) { to_gpd_data(pdd)->td.constraint_changed = true; genpd = dev_to_genpd(dev); } else { @@ -1266,6 +1266,27 @@ static void pm_genpd_complete(struct device *dev) #endif /* CONFIG_PM_SLEEP */ +static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev) +{ + struct generic_pm_domain_data *gpd_data; + + gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL); + if (!gpd_data) + return NULL; + + mutex_init(&gpd_data->lock); + gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; + dev_pm_qos_add_notifier(dev, &gpd_data->nb); + return gpd_data; +} + +static void __pm_genpd_free_dev_data(struct device *dev, + struct generic_pm_domain_data *gpd_data) +{ + dev_pm_qos_remove_notifier(dev, &gpd_data->nb); + kfree(gpd_data); +} + /** * __pm_genpd_add_device - Add a device to an I/O PM domain. * @genpd: PM domain to add the device to. @@ -1275,7 +1296,7 @@ static void pm_genpd_complete(struct device *dev) 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; + struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL; struct pm_domain_data *pdd; int ret = 0; @@ -1284,14 +1305,10 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) return -EINVAL; - gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL); - if (!gpd_data) + gpd_data_new = __pm_genpd_alloc_dev_data(dev); + if (!gpd_data_new) return -ENOMEM; - mutex_init(&gpd_data->lock); - gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; - dev_pm_qos_add_notifier(dev, &gpd_data->nb); - genpd_acquire_lock(genpd); if (genpd->prepared_count > 0) { @@ -1305,35 +1322,42 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, goto out; } + ret = dev_pm_get_subsys_data(dev); + if (ret) + goto out; + genpd->device_count++; genpd->max_off_time_changed = true; - dev_pm_get_subsys_data(dev); - - mutex_lock(&gpd_data->lock); spin_lock_irq(&dev->power.lock); + dev->pm_domain = &genpd->domain; - dev->power.subsys_data->domain_data = &gpd_data->base; - gpd_data->base.dev = dev; - list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); - gpd_data->need_restore = genpd->status == GPD_STATE_POWER_OFF; + if (dev->power.subsys_data->domain_data) { + gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); + } else { + gpd_data = gpd_data_new; + dev->power.subsys_data->domain_data = &gpd_data->base; + } + gpd_data->refcount++; if (td) gpd_data->td = *td; + spin_unlock_irq(&dev->power.lock); + + mutex_lock(&gpd_data->lock); + gpd_data->base.dev = dev; + list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); + gpd_data->need_restore = genpd->status == GPD_STATE_POWER_OFF; gpd_data->td.constraint_changed = true; gpd_data->td.effective_constraint_ns = -1; - spin_unlock_irq(&dev->power.lock); mutex_unlock(&gpd_data->lock); - genpd_release_lock(genpd); - - return 0; - out: genpd_release_lock(genpd); - dev_pm_qos_remove_notifier(dev, &gpd_data->nb); - kfree(gpd_data); + if (gpd_data != gpd_data_new) + __pm_genpd_free_dev_data(dev, gpd_data_new); + return ret; } @@ -1379,6 +1403,7 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, { struct generic_pm_domain_data *gpd_data; struct pm_domain_data *pdd; + bool remove = false; int ret = 0; dev_dbg(dev, "%s()\n", __func__); @@ -1399,22 +1424,28 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, genpd->max_off_time_changed = true; spin_lock_irq(&dev->power.lock); + dev->pm_domain = NULL; pdd = dev->power.subsys_data->domain_data; list_del_init(&pdd->list_node); - dev->power.subsys_data->domain_data = NULL; + gpd_data = to_gpd_data(pdd); + if (--gpd_data->refcount == 0) { + dev->power.subsys_data->domain_data = NULL; + remove = true; + } + spin_unlock_irq(&dev->power.lock); - gpd_data = to_gpd_data(pdd); mutex_lock(&gpd_data->lock); pdd->dev = NULL; mutex_unlock(&gpd_data->lock); genpd_release_lock(genpd); - dev_pm_qos_remove_notifier(dev, &gpd_data->nb); - kfree(gpd_data); dev_pm_put_subsys_data(dev); + if (remove) + __pm_genpd_free_dev_data(dev, gpd_data); + return 0; out: diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 2febe31d2675..a7d6172922d4 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -112,6 +112,7 @@ struct generic_pm_domain_data { struct gpd_timing_data td; struct notifier_block nb; struct mutex lock; + unsigned int refcount; bool need_restore; bool always_on; }; -- cgit v1.2.3 From 62d4490294e3de7015f715c00af992d7b6a6e22c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rjw@sisk.pl> Date: Thu, 5 Jul 2012 22:12:54 +0200 Subject: PM / Domains: Allow device callbacks to be added at any time Make it possible to modify device callbacks used by the generic PM domains core code at any time, not only after the device has been added to a domain. This will allow device drivers to provide their own device PM domain callbacks even if they are registered before adding the devices to PM domains. For this purpose, use the observation that the struct generic_pm_domain_data object containing the relevant callback pointers may be allocated by pm_genpd_add_callbacks() and the callbacks may be set before __pm_genpd_add_device() is run for the given device. This object will then be used by __pm_genpd_add_device(), but it has to be protected from premature removal by reference counting. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 64 +++++++++++++++++++++++++++++++++++---------- 1 file changed, 50 insertions(+), 14 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 45eb3b155b6d..9727bc56320a 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1603,33 +1603,52 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, * @dev: Device to add the callbacks to. * @ops: Set of callbacks to add. * @td: Timing data to add to the device along with the callbacks (optional). + * + * Every call to this routine should be balanced with a call to + * __pm_genpd_remove_callbacks() and they must not be nested. */ int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops, struct gpd_timing_data *td) { - struct pm_domain_data *pdd; + struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL; int ret = 0; - if (!(dev && dev->power.subsys_data && ops)) + if (!(dev && ops)) return -EINVAL; + gpd_data_new = __pm_genpd_alloc_dev_data(dev); + if (!gpd_data_new) + return -ENOMEM; + pm_runtime_disable(dev); device_pm_lock(); - pdd = dev->power.subsys_data->domain_data; - if (pdd) { - struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); + ret = dev_pm_get_subsys_data(dev); + if (ret) + goto out; + + spin_lock_irq(&dev->power.lock); - gpd_data->ops = *ops; - if (td) - gpd_data->td = *td; + if (dev->power.subsys_data->domain_data) { + gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); } else { - ret = -EINVAL; + gpd_data = gpd_data_new; + dev->power.subsys_data->domain_data = &gpd_data->base; } + gpd_data->refcount++; + gpd_data->ops = *ops; + if (td) + gpd_data->td = *td; + spin_unlock_irq(&dev->power.lock); + + out: device_pm_unlock(); pm_runtime_enable(dev); + if (gpd_data != gpd_data_new) + __pm_genpd_free_dev_data(dev, gpd_data_new); + return ret; } EXPORT_SYMBOL_GPL(pm_genpd_add_callbacks); @@ -1638,10 +1657,13 @@ EXPORT_SYMBOL_GPL(pm_genpd_add_callbacks); * __pm_genpd_remove_callbacks - Remove PM domain callbacks from a given device. * @dev: Device to remove the callbacks from. * @clear_td: If set, clear the device's timing data too. + * + * This routine can only be called after pm_genpd_add_callbacks(). */ int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td) { - struct pm_domain_data *pdd; + struct generic_pm_domain_data *gpd_data = NULL; + bool remove = false; int ret = 0; if (!(dev && dev->power.subsys_data)) @@ -1650,21 +1672,35 @@ int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td) pm_runtime_disable(dev); device_pm_lock(); - pdd = dev->power.subsys_data->domain_data; - if (pdd) { - struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); + spin_lock_irq(&dev->power.lock); + if (dev->power.subsys_data->domain_data) { + gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); gpd_data->ops = (struct gpd_dev_ops){ 0 }; if (clear_td) gpd_data->td = (struct gpd_timing_data){ 0 }; + + if (--gpd_data->refcount == 0) { + dev->power.subsys_data->domain_data = NULL; + remove = true; + } } else { ret = -EINVAL; } + spin_unlock_irq(&dev->power.lock); + device_pm_unlock(); pm_runtime_enable(dev); - return ret; + if (ret) + return ret; + + dev_pm_put_subsys_data(dev); + if (remove) + __pm_genpd_free_dev_data(dev, gpd_data); + + return 0; } EXPORT_SYMBOL_GPL(__pm_genpd_remove_callbacks); -- cgit v1.2.3 From 8951ef021904752a843a81fee785f1b180f31c07 Mon Sep 17 00:00:00 2001 From: Sachin Kamat <sachin.kamat@linaro.org> Date: Tue, 10 Jul 2012 21:47:07 +0200 Subject: PM / Domains: Add missing static storage class specifier in domain.c file Fixes the folloiwng sparse warning: drivers/base/power/domain.c:149:5: warning: symbol '__pm_genpd_poweron' was not declared. Should it be static? Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 9727bc56320a..4f8e0d2e7780 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -159,7 +159,7 @@ static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd) * Restore power to @genpd and all of its masters so that it is possible to * resume a device belonging to it. */ -int __pm_genpd_poweron(struct generic_pm_domain *genpd) +static int __pm_genpd_poweron(struct generic_pm_domain *genpd) __releases(&genpd->lock) __acquires(&genpd->lock) { struct gpd_link *link; -- cgit v1.2.3 From db79e53dd5957321ca78efe6c0cda578034e381b Mon Sep 17 00:00:00 2001 From: Sachin Kamat <sachin.kamat@linaro.org> Date: Wed, 11 Jul 2012 12:25:49 +0200 Subject: PM / Domains: Replace plain integer with NULL pointer in domain.c file Fixes the following sparse warning: drivers/base/power/domain.c:1679:55: warning: Using plain integer as NULL pointer Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 4f8e0d2e7780..8d6741780b0f 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1676,7 +1676,7 @@ int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td) if (dev->power.subsys_data->domain_data) { gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); - gpd_data->ops = (struct gpd_dev_ops){ 0 }; + gpd_data->ops = (struct gpd_dev_ops){ NULL }; if (clear_td) gpd_data->td = (struct gpd_timing_data){ 0 }; -- cgit v1.2.3 From 8e9afafdad59f5973a5e72e05db9802f82091398 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rjw@sisk.pl> Date: Wed, 11 Jul 2012 22:42:52 +0200 Subject: PM / Domains: Fix build warning for CONFIG_PM_RUNTIME unset The functions genpd_save_dev() and genpd_restore_dev() are not used for CONFIG_PM_RUNTIME unset, so move them under an appropriate #ifdef. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 8d6741780b0f..ba3487c9835b 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -75,19 +75,6 @@ static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev) start_latency_ns, "start"); } -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 bool genpd_sd_counter_dec(struct generic_pm_domain *genpd) { bool ret = false; @@ -273,6 +260,19 @@ int pm_genpd_poweron(struct generic_pm_domain *genpd) #ifdef CONFIG_PM_RUNTIME +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) { -- cgit v1.2.3