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-rw-r--r--Documentation/ABI/testing/sysfs-devices-power18
-rw-r--r--drivers/base/power/power.h4
-rw-r--r--drivers/base/power/qos.c61
-rw-r--r--drivers/base/power/sysfs.c47
-rw-r--r--include/linux/pm.h1
-rw-r--r--include/linux/pm_qos.h9
6 files changed, 140 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index 8ffbc25376a0..840f7d64d483 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 9bf62323aaf3..eeb4bff9505c 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 c5d358837461..71855570922d 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 adf41be0ea66..95c12f6cb5b9 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 73c610573a74..4db39ed1a6ef 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 c8a541e13380..2e9191a712f3 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
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-31 11:05:02 +0000