linux-stable/include/linux/pm_runtime.h
Vincent Guittot 8234f6734c PM-runtime: Switch autosuspend over to using hrtimers
PM-runtime uses the timer infrastructure for autosuspend. This implies
that the minimum time before autosuspending a device is in the range
of 1 tick included to 2 ticks excluded
 -On arm64 this means between 4ms and 8ms with default jiffies
  configuration
 -And on arm, it is between 10ms and 20ms

These values are quite high for embedded systems which sometimes want
the duration to be in the range of 1 ms.

It is possible to switch autosuspend over to using hrtimers to get
finer granularity for short durations and take advantage of slack to
retain some margins and get long timeouts with minimum wakeups.

On an arm64 platform that uses 1ms for autosuspending timeout of its
GPU, idle power is reduced by 10% with hrtimer.

The latency impact on arm64 hikey octo cores is:
 - mark_last_busy: from 1.11 us to 1.25 us
 - rpm_suspend: from 15.54 us to 15.38 us
[Only the code path of rpm_suspend() that starts hrtimer has been
measured.]

arm64 image (arm64 default defconfig) decreases by around 3KB
with following details:

$ size vmlinux-timer
   text	   data	    bss	    dec	    hex	filename
12034646	6869268	 386840	19290754	1265a82	vmlinux

$ size vmlinux-hrtimer
   text	   data	    bss	    dec	    hex	filename
12030550	6870164	 387032	19287746	1264ec2	vmlinux

The latency impact on arm 32bits snowball dual cores is :
 - mark_last_busy: from 0.31 us usec to 0.77 us
 - rpm_suspend: from 6.83 us to 6.67 usec

The increase of the image for snowball platform that I used for
testing performance impact, is neglictable (244B).

$ size vmlinux-timer
   text	   data	    bss	    dec	    hex	filename
7157961	2119580	 264120	9541661	 91981d	build-ux500/vmlinux

size vmlinux-hrtimer
   text	   data	    bss	    dec	    hex	filename
7157773	2119884	 264248	9541905	 919911	vmlinux-hrtimer

And arm 32bits image (multi_v7_defconfig) increases by around 1.7KB
with following details:

$ size vmlinux-timer
   text	   data	    bss	    dec	    hex	filename
13304443	6803420	 402768	20510631	138f7a7	vmlinux

$ size vmlinux-hrtimer
   text	   data	    bss	    dec	    hex	filename
13304299	6805276	 402768	20512343	138fe57	vmlinux

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-19 10:31:50 +01:00

279 lines
8.5 KiB
C

/*
* pm_runtime.h - Device run-time power management helper functions.
*
* Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>
*
* This file is released under the GPLv2.
*/
#ifndef _LINUX_PM_RUNTIME_H
#define _LINUX_PM_RUNTIME_H
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/pm.h>
#include <linux/jiffies.h>
/* Runtime PM flag argument bits */
#define RPM_ASYNC 0x01 /* Request is asynchronous */
#define RPM_NOWAIT 0x02 /* Don't wait for concurrent
state change */
#define RPM_GET_PUT 0x04 /* Increment/decrement the
usage_count */
#define RPM_AUTO 0x08 /* Use autosuspend_delay */
#ifdef CONFIG_PM
extern struct workqueue_struct *pm_wq;
static inline bool queue_pm_work(struct work_struct *work)
{
return queue_work(pm_wq, work);
}
extern int pm_generic_runtime_suspend(struct device *dev);
extern int pm_generic_runtime_resume(struct device *dev);
extern int pm_runtime_force_suspend(struct device *dev);
extern int pm_runtime_force_resume(struct device *dev);
extern int __pm_runtime_idle(struct device *dev, int rpmflags);
extern int __pm_runtime_suspend(struct device *dev, int rpmflags);
extern int __pm_runtime_resume(struct device *dev, int rpmflags);
extern int pm_runtime_get_if_in_use(struct device *dev);
extern int pm_schedule_suspend(struct device *dev, unsigned int delay);
extern int __pm_runtime_set_status(struct device *dev, unsigned int status);
extern int pm_runtime_barrier(struct device *dev);
extern void pm_runtime_enable(struct device *dev);
extern void __pm_runtime_disable(struct device *dev, bool check_resume);
extern void pm_runtime_allow(struct device *dev);
extern void pm_runtime_forbid(struct device *dev);
extern void pm_runtime_no_callbacks(struct device *dev);
extern void pm_runtime_irq_safe(struct device *dev);
extern void __pm_runtime_use_autosuspend(struct device *dev, bool use);
extern void pm_runtime_set_autosuspend_delay(struct device *dev, int delay);
extern u64 pm_runtime_autosuspend_expiration(struct device *dev);
extern void pm_runtime_update_max_time_suspended(struct device *dev,
s64 delta_ns);
extern void pm_runtime_set_memalloc_noio(struct device *dev, bool enable);
extern void pm_runtime_clean_up_links(struct device *dev);
extern void pm_runtime_get_suppliers(struct device *dev);
extern void pm_runtime_put_suppliers(struct device *dev);
extern void pm_runtime_new_link(struct device *dev);
extern void pm_runtime_drop_link(struct device *dev);
static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
{
dev->power.ignore_children = enable;
}
static inline void pm_runtime_get_noresume(struct device *dev)
{
atomic_inc(&dev->power.usage_count);
}
static inline void pm_runtime_put_noidle(struct device *dev)
{
atomic_add_unless(&dev->power.usage_count, -1, 0);
}
static inline bool pm_runtime_suspended(struct device *dev)
{
return dev->power.runtime_status == RPM_SUSPENDED
&& !dev->power.disable_depth;
}
static inline bool pm_runtime_active(struct device *dev)
{
return dev->power.runtime_status == RPM_ACTIVE
|| dev->power.disable_depth;
}
static inline bool pm_runtime_status_suspended(struct device *dev)
{
return dev->power.runtime_status == RPM_SUSPENDED;
}
static inline bool pm_runtime_enabled(struct device *dev)
{
return !dev->power.disable_depth;
}
static inline bool pm_runtime_callbacks_present(struct device *dev)
{
return !dev->power.no_callbacks;
}
static inline void pm_runtime_mark_last_busy(struct device *dev)
{
WRITE_ONCE(dev->power.last_busy, ktime_to_ns(ktime_get()));
}
static inline bool pm_runtime_is_irq_safe(struct device *dev)
{
return dev->power.irq_safe;
}
#else /* !CONFIG_PM */
static inline bool queue_pm_work(struct work_struct *work) { return false; }
static inline int pm_generic_runtime_suspend(struct device *dev) { return 0; }
static inline int pm_generic_runtime_resume(struct device *dev) { return 0; }
static inline int pm_runtime_force_suspend(struct device *dev) { return 0; }
static inline int pm_runtime_force_resume(struct device *dev) { return 0; }
static inline int __pm_runtime_idle(struct device *dev, int rpmflags)
{
return -ENOSYS;
}
static inline int __pm_runtime_suspend(struct device *dev, int rpmflags)
{
return -ENOSYS;
}
static inline int __pm_runtime_resume(struct device *dev, int rpmflags)
{
return 1;
}
static inline int pm_schedule_suspend(struct device *dev, unsigned int delay)
{
return -ENOSYS;
}
static inline int pm_runtime_get_if_in_use(struct device *dev)
{
return -EINVAL;
}
static inline int __pm_runtime_set_status(struct device *dev,
unsigned int status) { return 0; }
static inline int pm_runtime_barrier(struct device *dev) { return 0; }
static inline void pm_runtime_enable(struct device *dev) {}
static inline void __pm_runtime_disable(struct device *dev, bool c) {}
static inline void pm_runtime_allow(struct device *dev) {}
static inline void pm_runtime_forbid(struct device *dev) {}
static inline void pm_suspend_ignore_children(struct device *dev, bool enable) {}
static inline void pm_runtime_get_noresume(struct device *dev) {}
static inline void pm_runtime_put_noidle(struct device *dev) {}
static inline bool pm_runtime_suspended(struct device *dev) { return false; }
static inline bool pm_runtime_active(struct device *dev) { return true; }
static inline bool pm_runtime_status_suspended(struct device *dev) { return false; }
static inline bool pm_runtime_enabled(struct device *dev) { return false; }
static inline void pm_runtime_no_callbacks(struct device *dev) {}
static inline void pm_runtime_irq_safe(struct device *dev) {}
static inline bool pm_runtime_is_irq_safe(struct device *dev) { return false; }
static inline bool pm_runtime_callbacks_present(struct device *dev) { return false; }
static inline void pm_runtime_mark_last_busy(struct device *dev) {}
static inline void __pm_runtime_use_autosuspend(struct device *dev,
bool use) {}
static inline void pm_runtime_set_autosuspend_delay(struct device *dev,
int delay) {}
static inline u64 pm_runtime_autosuspend_expiration(
struct device *dev) { return 0; }
static inline void pm_runtime_set_memalloc_noio(struct device *dev,
bool enable){}
static inline void pm_runtime_clean_up_links(struct device *dev) {}
static inline void pm_runtime_get_suppliers(struct device *dev) {}
static inline void pm_runtime_put_suppliers(struct device *dev) {}
static inline void pm_runtime_new_link(struct device *dev) {}
static inline void pm_runtime_drop_link(struct device *dev) {}
#endif /* !CONFIG_PM */
static inline int pm_runtime_idle(struct device *dev)
{
return __pm_runtime_idle(dev, 0);
}
static inline int pm_runtime_suspend(struct device *dev)
{
return __pm_runtime_suspend(dev, 0);
}
static inline int pm_runtime_autosuspend(struct device *dev)
{
return __pm_runtime_suspend(dev, RPM_AUTO);
}
static inline int pm_runtime_resume(struct device *dev)
{
return __pm_runtime_resume(dev, 0);
}
static inline int pm_request_idle(struct device *dev)
{
return __pm_runtime_idle(dev, RPM_ASYNC);
}
static inline int pm_request_resume(struct device *dev)
{
return __pm_runtime_resume(dev, RPM_ASYNC);
}
static inline int pm_request_autosuspend(struct device *dev)
{
return __pm_runtime_suspend(dev, RPM_ASYNC | RPM_AUTO);
}
static inline int pm_runtime_get(struct device *dev)
{
return __pm_runtime_resume(dev, RPM_GET_PUT | RPM_ASYNC);
}
static inline int pm_runtime_get_sync(struct device *dev)
{
return __pm_runtime_resume(dev, RPM_GET_PUT);
}
static inline int pm_runtime_put(struct device *dev)
{
return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC);
}
static inline int pm_runtime_put_autosuspend(struct device *dev)
{
return __pm_runtime_suspend(dev,
RPM_GET_PUT | RPM_ASYNC | RPM_AUTO);
}
static inline int pm_runtime_put_sync(struct device *dev)
{
return __pm_runtime_idle(dev, RPM_GET_PUT);
}
static inline int pm_runtime_put_sync_suspend(struct device *dev)
{
return __pm_runtime_suspend(dev, RPM_GET_PUT);
}
static inline int pm_runtime_put_sync_autosuspend(struct device *dev)
{
return __pm_runtime_suspend(dev, RPM_GET_PUT | RPM_AUTO);
}
static inline int pm_runtime_set_active(struct device *dev)
{
return __pm_runtime_set_status(dev, RPM_ACTIVE);
}
static inline int pm_runtime_set_suspended(struct device *dev)
{
return __pm_runtime_set_status(dev, RPM_SUSPENDED);
}
static inline void pm_runtime_disable(struct device *dev)
{
__pm_runtime_disable(dev, true);
}
static inline void pm_runtime_use_autosuspend(struct device *dev)
{
__pm_runtime_use_autosuspend(dev, true);
}
static inline void pm_runtime_dont_use_autosuspend(struct device *dev)
{
__pm_runtime_use_autosuspend(dev, false);
}
#endif