diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-power | 18 | ||||
| -rw-r--r-- | drivers/base/power/power.h | 4 | ||||
| -rw-r--r-- | drivers/base/power/qos.c | 61 | ||||
| -rw-r--r-- | drivers/base/power/sysfs.c | 47 | ||||
| -rw-r--r-- | include/linux/pm.h | 1 | ||||
| -rw-r--r-- | include/linux/pm_qos.h | 9 |
6 files changed, 140 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index 8ffbc25..840f7d6 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -165,3 +165,21 @@ Description: Not all drivers support this attribute. If it isn't supported, attempts to read or write it will yield I/O errors. + +What: /sys/devices/.../power/pm_qos_latency_us +Date: March 2012 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/devices/.../power/pm_qos_resume_latency_us attribute + contains the PM QoS resume latency limit for the given device, + which is the maximum allowed time it can take to resume the + device, after it has been suspended at run time, from a resume + request to the moment the device will be ready to process I/O, + in microseconds. If it is equal to 0, however, this means that + the PM QoS resume latency may be arbitrary. + + Not all drivers support this attribute. If it isn't supported, + it is not present. + + This attribute has no effect on system-wide suspend/resume and + hibernation. diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index 9bf6232..eeb4bff 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -71,6 +71,8 @@ extern void dpm_sysfs_remove(struct device *dev); extern void rpm_sysfs_remove(struct device *dev); extern int wakeup_sysfs_add(struct device *dev); extern void wakeup_sysfs_remove(struct device *dev); +extern int pm_qos_sysfs_add(struct device *dev); +extern void pm_qos_sysfs_remove(struct device *dev); #else /* CONFIG_PM */ @@ -79,5 +81,7 @@ static inline void dpm_sysfs_remove(struct device *dev) {} static inline void rpm_sysfs_remove(struct device *dev) {} static inline int wakeup_sysfs_add(struct device *dev) { return 0; } static inline void wakeup_sysfs_remove(struct device *dev) {} +static inline int pm_qos_sysfs_add(struct device *dev) { return 0; } +static inline void pm_qos_sysfs_remove(struct device *dev) {} #endif diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index c5d3588..7185557 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -41,6 +41,7 @@ #include <linux/mutex.h> #include <linux/export.h> +#include "power.h" static DEFINE_MUTEX(dev_pm_qos_mtx); @@ -166,6 +167,12 @@ void dev_pm_qos_constraints_destroy(struct device *dev) struct dev_pm_qos_request *req, *tmp; struct pm_qos_constraints *c; + /* + * If the device's PM QoS resume latency limit has been exposed to user + * space, it has to be hidden at this point. + */ + dev_pm_qos_hide_latency_limit(dev); + mutex_lock(&dev_pm_qos_mtx); dev->power.power_state = PMSG_INVALID; @@ -445,3 +452,57 @@ int dev_pm_qos_add_ancestor_request(struct device *dev, return error; } EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request); + +#ifdef CONFIG_PM_RUNTIME +static void __dev_pm_qos_drop_user_request(struct device *dev) +{ + dev_pm_qos_remove_request(dev->power.pq_req); + dev->power.pq_req = 0; +} + +/** + * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space. + * @dev: Device whose PM QoS latency limit is to be exposed to user space. + * @value: Initial value of the latency limit. + */ +int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) +{ + struct dev_pm_qos_request *req; + int ret; + + if (!device_is_registered(dev) || value < 0) + return -EINVAL; + + if (dev->power.pq_req) + return -EEXIST; + + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return -ENOMEM; + + ret = dev_pm_qos_add_request(dev, req, value); + if (ret < 0) + return ret; + + dev->power.pq_req = req; + ret = pm_qos_sysfs_add(dev); + if (ret) + __dev_pm_qos_drop_user_request(dev); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit); + +/** + * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space. + * @dev: Device whose PM QoS latency limit is to be hidden from user space. + */ +void dev_pm_qos_hide_latency_limit(struct device *dev) +{ + if (dev->power.pq_req) { + pm_qos_sysfs_remove(dev); + __dev_pm_qos_drop_user_request(dev); + } +} +EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit); +#endif /* CONFIG_PM_RUNTIME */ diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index adf41be0..95c12f6 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -5,6 +5,7 @@ #include <linux/device.h> #include <linux/string.h> #include <linux/export.h> +#include <linux/pm_qos.h> #include <linux/pm_runtime.h> #include <linux/atomic.h> #include <linux/jiffies.h> @@ -217,6 +218,31 @@ static ssize_t autosuspend_delay_ms_store(struct device *dev, static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show, autosuspend_delay_ms_store); +static ssize_t pm_qos_latency_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", dev->power.pq_req->node.prio); +} + +static ssize_t pm_qos_latency_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t n) +{ + s32 value; + int ret; + + if (kstrtos32(buf, 0, &value)) + return -EINVAL; + + if (value < 0) + return -EINVAL; + + ret = dev_pm_qos_update_request(dev->power.pq_req, value); + return ret < 0 ? ret : n; +} + +static DEVICE_ATTR(pm_qos_resume_latency_us, 0644, + pm_qos_latency_show, pm_qos_latency_store); #endif /* CONFIG_PM_RUNTIME */ #ifdef CONFIG_PM_SLEEP @@ -490,6 +516,17 @@ static struct attribute_group pm_runtime_attr_group = { .attrs = runtime_attrs, }; +static struct attribute *pm_qos_attrs[] = { +#ifdef CONFIG_PM_RUNTIME + &dev_attr_pm_qos_resume_latency_us.attr, +#endif /* CONFIG_PM_RUNTIME */ + NULL, +}; +static struct attribute_group pm_qos_attr_group = { + .name = power_group_name, + .attrs = pm_qos_attrs, +}; + int dpm_sysfs_add(struct device *dev) { int rc; @@ -530,6 +567,16 @@ void wakeup_sysfs_remove(struct device *dev) sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group); } +int pm_qos_sysfs_add(struct device *dev) +{ + return sysfs_merge_group(&dev->kobj, &pm_qos_attr_group); +} + +void pm_qos_sysfs_remove(struct device *dev) +{ + sysfs_unmerge_group(&dev->kobj, &pm_qos_attr_group); +} + void rpm_sysfs_remove(struct device *dev) { sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group); diff --git a/include/linux/pm.h b/include/linux/pm.h index 73c6105..4db39ed 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -537,6 +537,7 @@ struct dev_pm_info { unsigned long accounting_timestamp; ktime_t suspend_time; s64 max_time_suspended_ns; + struct dev_pm_qos_request *pq_req; #endif struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */ struct pm_qos_constraints *constraints; diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index c8a541e..2e9191a 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -137,4 +137,13 @@ static inline int dev_pm_qos_add_ancestor_request(struct device *dev, { return 0; } #endif +#ifdef CONFIG_PM_RUNTIME +int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value); +void dev_pm_qos_hide_latency_limit(struct device *dev); +#else +static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) + { return 0; } +static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {} +#endif + #endif |