273 lines
7.4 KiB
C
273 lines
7.4 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* Copyright (C) 2019 Linaro Limited.
|
||
|
|
*
|
||
|
|
* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
#define pr_fmt(fmt) "cpuidle cooling: " fmt
|
||
|
|
|
||
|
|
#include <linux/cpu_cooling.h>
|
||
|
|
#include <linux/cpuidle.h>
|
||
|
|
#include <linux/device.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
#include <linux/idle_inject.h>
|
||
|
|
#include <linux/of_device.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
#include <linux/thermal.h>
|
||
|
|
|
||
|
|
/**
|
||
|
|
* struct cpuidle_cooling_device - data for the idle cooling device
|
||
|
|
* @ii_dev: an atomic to keep track of the last task exiting the idle cycle
|
||
|
|
* @state: a normalized integer giving the state of the cooling device
|
||
|
|
*/
|
||
|
|
struct cpuidle_cooling_device {
|
||
|
|
struct idle_inject_device *ii_dev;
|
||
|
|
unsigned long state;
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* cpuidle_cooling_runtime - Running time computation
|
||
|
|
* @idle_duration_us: CPU idle time to inject in microseconds
|
||
|
|
* @state: a percentile based number
|
||
|
|
*
|
||
|
|
* The running duration is computed from the idle injection duration
|
||
|
|
* which is fixed. If we reach 100% of idle injection ratio, that
|
||
|
|
* means the running duration is zero. If we have a 50% ratio
|
||
|
|
* injection, that means we have equal duration for idle and for
|
||
|
|
* running duration.
|
||
|
|
*
|
||
|
|
* The formula is deduced as follows:
|
||
|
|
*
|
||
|
|
* running = idle x ((100 / ratio) - 1)
|
||
|
|
*
|
||
|
|
* For precision purpose for integer math, we use the following:
|
||
|
|
*
|
||
|
|
* running = (idle x 100) / ratio - idle
|
||
|
|
*
|
||
|
|
* For example, if we have an injected duration of 50%, then we end up
|
||
|
|
* with 10ms of idle injection and 10ms of running duration.
|
||
|
|
*
|
||
|
|
* Return: An unsigned int for a usec based runtime duration.
|
||
|
|
*/
|
||
|
|
static unsigned int cpuidle_cooling_runtime(unsigned int idle_duration_us,
|
||
|
|
unsigned long state)
|
||
|
|
{
|
||
|
|
if (!state)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
return ((idle_duration_us * 100) / state) - idle_duration_us;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* cpuidle_cooling_get_max_state - Get the maximum state
|
||
|
|
* @cdev : the thermal cooling device
|
||
|
|
* @state : a pointer to the state variable to be filled
|
||
|
|
*
|
||
|
|
* The function always returns 100 as the injection ratio. It is
|
||
|
|
* percentile based for consistency accross different platforms.
|
||
|
|
*
|
||
|
|
* Return: The function can not fail, it is always zero
|
||
|
|
*/
|
||
|
|
static int cpuidle_cooling_get_max_state(struct thermal_cooling_device *cdev,
|
||
|
|
unsigned long *state)
|
||
|
|
{
|
||
|
|
/*
|
||
|
|
* Depending on the configuration or the hardware, the running
|
||
|
|
* cycle and the idle cycle could be different. We want to
|
||
|
|
* unify that to an 0..100 interval, so the set state
|
||
|
|
* interface will be the same whatever the platform is.
|
||
|
|
*
|
||
|
|
* The state 100% will make the cluster 100% ... idle. A 0%
|
||
|
|
* injection ratio means no idle injection at all and 50%
|
||
|
|
* means for 10ms of idle injection, we have 10ms of running
|
||
|
|
* time.
|
||
|
|
*/
|
||
|
|
*state = 100;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* cpuidle_cooling_get_cur_state - Get the current cooling state
|
||
|
|
* @cdev: the thermal cooling device
|
||
|
|
* @state: a pointer to the state
|
||
|
|
*
|
||
|
|
* The function just copies the state value from the private thermal
|
||
|
|
* cooling device structure, the mapping is 1 <-> 1.
|
||
|
|
*
|
||
|
|
* Return: The function can not fail, it is always zero
|
||
|
|
*/
|
||
|
|
static int cpuidle_cooling_get_cur_state(struct thermal_cooling_device *cdev,
|
||
|
|
unsigned long *state)
|
||
|
|
{
|
||
|
|
struct cpuidle_cooling_device *idle_cdev = cdev->devdata;
|
||
|
|
|
||
|
|
*state = idle_cdev->state;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* cpuidle_cooling_set_cur_state - Set the current cooling state
|
||
|
|
* @cdev: the thermal cooling device
|
||
|
|
* @state: the target state
|
||
|
|
*
|
||
|
|
* The function checks first if we are initiating the mitigation which
|
||
|
|
* in turn wakes up all the idle injection tasks belonging to the idle
|
||
|
|
* cooling device. In any case, it updates the internal state for the
|
||
|
|
* cooling device.
|
||
|
|
*
|
||
|
|
* Return: The function can not fail, it is always zero
|
||
|
|
*/
|
||
|
|
static int cpuidle_cooling_set_cur_state(struct thermal_cooling_device *cdev,
|
||
|
|
unsigned long state)
|
||
|
|
{
|
||
|
|
struct cpuidle_cooling_device *idle_cdev = cdev->devdata;
|
||
|
|
struct idle_inject_device *ii_dev = idle_cdev->ii_dev;
|
||
|
|
unsigned long current_state = idle_cdev->state;
|
||
|
|
unsigned int runtime_us, idle_duration_us;
|
||
|
|
|
||
|
|
idle_cdev->state = state;
|
||
|
|
|
||
|
|
idle_inject_get_duration(ii_dev, &runtime_us, &idle_duration_us);
|
||
|
|
|
||
|
|
runtime_us = cpuidle_cooling_runtime(idle_duration_us, state);
|
||
|
|
|
||
|
|
idle_inject_set_duration(ii_dev, runtime_us, idle_duration_us);
|
||
|
|
|
||
|
|
if (current_state == 0 && state > 0) {
|
||
|
|
idle_inject_start(ii_dev);
|
||
|
|
} else if (current_state > 0 && !state) {
|
||
|
|
idle_inject_stop(ii_dev);
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* cpuidle_cooling_ops - thermal cooling device ops
|
||
|
|
*/
|
||
|
|
static struct thermal_cooling_device_ops cpuidle_cooling_ops = {
|
||
|
|
.get_max_state = cpuidle_cooling_get_max_state,
|
||
|
|
.get_cur_state = cpuidle_cooling_get_cur_state,
|
||
|
|
.set_cur_state = cpuidle_cooling_set_cur_state,
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* __cpuidle_cooling_register: register the cooling device
|
||
|
|
* @drv: a cpuidle driver structure pointer
|
||
|
|
* @np: a device node structure pointer used for the thermal binding
|
||
|
|
*
|
||
|
|
* This function is in charge of allocating the cpuidle cooling device
|
||
|
|
* structure, the idle injection, initialize them and register the
|
||
|
|
* cooling device to the thermal framework.
|
||
|
|
*
|
||
|
|
* Return: zero on success, a negative value returned by one of the
|
||
|
|
* underlying subsystem in case of error
|
||
|
|
*/
|
||
|
|
static int __cpuidle_cooling_register(struct device_node *np,
|
||
|
|
struct cpuidle_driver *drv)
|
||
|
|
{
|
||
|
|
struct idle_inject_device *ii_dev;
|
||
|
|
struct cpuidle_cooling_device *idle_cdev;
|
||
|
|
struct thermal_cooling_device *cdev;
|
||
|
|
struct device *dev;
|
||
|
|
unsigned int idle_duration_us = TICK_USEC;
|
||
|
|
unsigned int latency_us = UINT_MAX;
|
||
|
|
char *name;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
idle_cdev = kzalloc(sizeof(*idle_cdev), GFP_KERNEL);
|
||
|
|
if (!idle_cdev) {
|
||
|
|
ret = -ENOMEM;
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
ii_dev = idle_inject_register(drv->cpumask);
|
||
|
|
if (!ii_dev) {
|
||
|
|
ret = -EINVAL;
|
||
|
|
goto out_kfree;
|
||
|
|
}
|
||
|
|
|
||
|
|
of_property_read_u32(np, "duration-us", &idle_duration_us);
|
||
|
|
of_property_read_u32(np, "exit-latency-us", &latency_us);
|
||
|
|
|
||
|
|
idle_inject_set_duration(ii_dev, TICK_USEC, idle_duration_us);
|
||
|
|
idle_inject_set_latency(ii_dev, latency_us);
|
||
|
|
|
||
|
|
idle_cdev->ii_dev = ii_dev;
|
||
|
|
|
||
|
|
dev = get_cpu_device(cpumask_first(drv->cpumask));
|
||
|
|
|
||
|
|
name = kasprintf(GFP_KERNEL, "idle-%s", dev_name(dev));
|
||
|
|
if (!name) {
|
||
|
|
ret = -ENOMEM;
|
||
|
|
goto out_unregister;
|
||
|
|
}
|
||
|
|
|
||
|
|
cdev = thermal_of_cooling_device_register(np, name, idle_cdev,
|
||
|
|
&cpuidle_cooling_ops);
|
||
|
|
if (IS_ERR(cdev)) {
|
||
|
|
ret = PTR_ERR(cdev);
|
||
|
|
goto out_kfree_name;
|
||
|
|
}
|
||
|
|
|
||
|
|
pr_debug("%s: Idle injection set with idle duration=%u, latency=%u\n",
|
||
|
|
name, idle_duration_us, latency_us);
|
||
|
|
|
||
|
|
kfree(name);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
out_kfree_name:
|
||
|
|
kfree(name);
|
||
|
|
out_unregister:
|
||
|
|
idle_inject_unregister(ii_dev);
|
||
|
|
out_kfree:
|
||
|
|
kfree(idle_cdev);
|
||
|
|
out:
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* cpuidle_cooling_register - Idle cooling device initialization function
|
||
|
|
* @drv: a cpuidle driver structure pointer
|
||
|
|
*
|
||
|
|
* This function is in charge of creating a cooling device per cpuidle
|
||
|
|
* driver and register it to the thermal framework.
|
||
|
|
*
|
||
|
|
* Return: zero on success, or negative value corresponding to the
|
||
|
|
* error detected in the underlying subsystems.
|
||
|
|
*/
|
||
|
|
void cpuidle_cooling_register(struct cpuidle_driver *drv)
|
||
|
|
{
|
||
|
|
struct device_node *cooling_node;
|
||
|
|
struct device_node *cpu_node;
|
||
|
|
int cpu, ret;
|
||
|
|
|
||
|
|
for_each_cpu(cpu, drv->cpumask) {
|
||
|
|
|
||
|
|
cpu_node = of_cpu_device_node_get(cpu);
|
||
|
|
|
||
|
|
cooling_node = of_get_child_by_name(cpu_node, "thermal-idle");
|
||
|
|
|
||
|
|
of_node_put(cpu_node);
|
||
|
|
|
||
|
|
if (!cooling_node) {
|
||
|
|
pr_debug("'thermal-idle' node not found for cpu%d\n", cpu);
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = __cpuidle_cooling_register(cooling_node, drv);
|
||
|
|
|
||
|
|
of_node_put(cooling_node);
|
||
|
|
|
||
|
|
if (ret) {
|
||
|
|
pr_err("Failed to register the cpuidle cooling device" \
|
||
|
|
"for cpu%d: %d\n", cpu, ret);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|