linux-stable/include/linux/pm_qos.h
Rafael J. Wysocki 00dc9ad18d PM / Runtime: Use device PM QoS constraints (v2)
Make the runtime PM core use device PM QoS constraints to check if
it is allowed to suspend a given device, so that an error code is
returned if the device's own PM QoS constraint is negative or one of
its children has already been suspended for too long.  If this is
not the case, the maximum estimated time the device is allowed to be
suspended, computed as the minimum of the device's PM QoS constraint
and the PM QoS constraints of its children (reduced by the difference
between the current time and their suspend times) is stored in a new
device's PM field power.max_time_suspended_ns that can be used by
the device's subsystem or PM domain to decide whether or not to put
the device into lower-power (and presumably higher-latency) states
later (if the constraint is 0, which means "no constraint", the
power.max_time_suspended_ns is set to -1).

Additionally, the time of execution of the subsystem-level
.runtime_suspend() callback for the device is recorded in the new
power.suspend_time field for later use by the device's subsystem or
PM domain along with power.max_time_suspended_ns (it also is used
by the core code when the device's parent is suspended).

Introduce a new helper function,
pm_runtime_update_max_time_suspended(), allowing subsystems and PM
domains (or device drivers) to update the power.max_time_suspended_ns
field, for example after changing the power state of a suspended
device.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01 21:46:42 +01:00

158 lines
5.1 KiB
C

#ifndef _LINUX_PM_QOS_H
#define _LINUX_PM_QOS_H
/* interface for the pm_qos_power infrastructure of the linux kernel.
*
* Mark Gross <mgross@linux.intel.com>
*/
#include <linux/plist.h>
#include <linux/notifier.h>
#include <linux/miscdevice.h>
#include <linux/device.h>
#define PM_QOS_RESERVED 0
#define PM_QOS_CPU_DMA_LATENCY 1
#define PM_QOS_NETWORK_LATENCY 2
#define PM_QOS_NETWORK_THROUGHPUT 3
#define PM_QOS_NUM_CLASSES 4
#define PM_QOS_DEFAULT_VALUE -1
#define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0
#define PM_QOS_DEV_LAT_DEFAULT_VALUE 0
struct pm_qos_request {
struct plist_node node;
int pm_qos_class;
};
struct dev_pm_qos_request {
struct plist_node node;
struct device *dev;
};
enum pm_qos_type {
PM_QOS_UNITIALIZED,
PM_QOS_MAX, /* return the largest value */
PM_QOS_MIN /* return the smallest value */
};
/*
* Note: The lockless read path depends on the CPU accessing
* target_value atomically. Atomic access is only guaranteed on all CPU
* types linux supports for 32 bit quantites
*/
struct pm_qos_constraints {
struct plist_head list;
s32 target_value; /* Do not change to 64 bit */
s32 default_value;
enum pm_qos_type type;
struct blocking_notifier_head *notifiers;
};
/* Action requested to pm_qos_update_target */
enum pm_qos_req_action {
PM_QOS_ADD_REQ, /* Add a new request */
PM_QOS_UPDATE_REQ, /* Update an existing request */
PM_QOS_REMOVE_REQ /* Remove an existing request */
};
static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
{
return req->dev != 0;
}
#ifdef CONFIG_PM
int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
enum pm_qos_req_action action, int value);
void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
s32 value);
void pm_qos_update_request(struct pm_qos_request *req,
s32 new_value);
void pm_qos_remove_request(struct pm_qos_request *req);
int pm_qos_request(int pm_qos_class);
int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_request_active(struct pm_qos_request *req);
s32 pm_qos_read_value(struct pm_qos_constraints *c);
s32 __dev_pm_qos_read_value(struct device *dev);
s32 dev_pm_qos_read_value(struct device *dev);
int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
s32 value);
int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
int dev_pm_qos_add_notifier(struct device *dev,
struct notifier_block *notifier);
int dev_pm_qos_remove_notifier(struct device *dev,
struct notifier_block *notifier);
int dev_pm_qos_add_global_notifier(struct notifier_block *notifier);
int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier);
void dev_pm_qos_constraints_init(struct device *dev);
void dev_pm_qos_constraints_destroy(struct device *dev);
#else
static inline int pm_qos_update_target(struct pm_qos_constraints *c,
struct plist_node *node,
enum pm_qos_req_action action,
int value)
{ return 0; }
static inline void pm_qos_add_request(struct pm_qos_request *req,
int pm_qos_class, s32 value)
{ return; }
static inline void pm_qos_update_request(struct pm_qos_request *req,
s32 new_value)
{ return; }
static inline void pm_qos_remove_request(struct pm_qos_request *req)
{ return; }
static inline int pm_qos_request(int pm_qos_class)
{ return 0; }
static inline int pm_qos_add_notifier(int pm_qos_class,
struct notifier_block *notifier)
{ return 0; }
static inline int pm_qos_remove_notifier(int pm_qos_class,
struct notifier_block *notifier)
{ return 0; }
static inline int pm_qos_request_active(struct pm_qos_request *req)
{ return 0; }
static inline s32 pm_qos_read_value(struct pm_qos_constraints *c)
{ return 0; }
static inline s32 __dev_pm_qos_read_value(struct device *dev)
{ return 0; }
static inline s32 dev_pm_qos_read_value(struct device *dev)
{ return 0; }
static inline int dev_pm_qos_add_request(struct device *dev,
struct dev_pm_qos_request *req,
s32 value)
{ return 0; }
static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
s32 new_value)
{ return 0; }
static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
{ return 0; }
static inline int dev_pm_qos_add_notifier(struct device *dev,
struct notifier_block *notifier)
{ return 0; }
static inline int dev_pm_qos_remove_notifier(struct device *dev,
struct notifier_block *notifier)
{ return 0; }
static inline int dev_pm_qos_add_global_notifier(
struct notifier_block *notifier)
{ return 0; }
static inline int dev_pm_qos_remove_global_notifier(
struct notifier_block *notifier)
{ return 0; }
static inline void dev_pm_qos_constraints_init(struct device *dev)
{
dev->power.power_state = PMSG_ON;
}
static inline void dev_pm_qos_constraints_destroy(struct device *dev)
{
dev->power.power_state = PMSG_INVALID;
}
#endif
#endif