linux_dsm_epyc7002/include/linux/idle_inject.h
Daniel Lezcano 333cff6c96 powercap/drivers/idle_inject: Specify idle state max latency
Currently the idle injection framework uses the play_idle() function
which puts the current CPU in an idle state. The idle state is the
deepest one, as specified by the latency constraint when calling the
subsequent play_idle_precise() function with the INT_MAX.

The idle_injection is used by the cpuidle_cooling device which
computes the idle / run duration to mitigate the temperature by
injecting idle cycles. The cooling device has no control on the depth
of the idle state.

Allow finer control of the idle injection mechanism by allowing to
specify the latency for the idle state. Thus the cooling device has
the ability to have a guarantee on the exit latency of the idle states
it is injecting.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Link: https://lore.kernel.org/r/20200429103644.5492-1-daniel.lezcano@linaro.org
2020-05-19 12:54:05 +02:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2018 Linaro Ltd
*
* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
*
*/
#ifndef __IDLE_INJECT_H__
#define __IDLE_INJECT_H__
/* private idle injection device structure */
struct idle_inject_device;
struct idle_inject_device *idle_inject_register(struct cpumask *cpumask);
void idle_inject_unregister(struct idle_inject_device *ii_dev);
int idle_inject_start(struct idle_inject_device *ii_dev);
void idle_inject_stop(struct idle_inject_device *ii_dev);
void idle_inject_set_duration(struct idle_inject_device *ii_dev,
unsigned int run_duration_us,
unsigned int idle_duration_us);
void idle_inject_get_duration(struct idle_inject_device *ii_dev,
unsigned int *run_duration_us,
unsigned int *idle_duration_us);
void idle_inject_set_latency(struct idle_inject_device *ii_dev,
unsigned int latency_ns);
#endif /* __IDLE_INJECT_H__ */