linux/drivers/acpi/processor_thermal.c
Thomas Gleixner c942fddf87 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

260 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* processor_thermal.c - Passive cooling submodule of the ACPI processor driver
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* - Added processor hotplug support
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/acpi.h>
#include <acpi/processor.h>
#include <linux/uaccess.h>
#define PREFIX "ACPI: "
#define ACPI_PROCESSOR_CLASS "processor"
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_thermal");
#ifdef CONFIG_CPU_FREQ
/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
* offers (in most cases) voltage scaling in addition to frequency scaling, and
* thus a cubic (instead of linear) reduction of energy. Also, we allow for
* _any_ cpufreq driver and not only the acpi-cpufreq driver.
*/
#define CPUFREQ_THERMAL_MIN_STEP 0
#define CPUFREQ_THERMAL_MAX_STEP 3
static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
static unsigned int acpi_thermal_cpufreq_is_init = 0;
#define reduction_pctg(cpu) \
per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
/*
* Emulate "per package data" using per cpu data (which should really be
* provided elsewhere)
*
* Note we can lose a CPU on cpu hotunplug, in this case we forget the state
* temporarily. Fortunately that's not a big issue here (I hope)
*/
static int phys_package_first_cpu(int cpu)
{
int i;
int id = topology_physical_package_id(cpu);
for_each_online_cpu(i)
if (topology_physical_package_id(i) == id)
return i;
return 0;
}
static int cpu_has_cpufreq(unsigned int cpu)
{
struct cpufreq_policy policy;
if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
return 0;
return 1;
}
static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
unsigned long event, void *data)
{
struct cpufreq_policy *policy = data;
unsigned long max_freq = 0;
if (event != CPUFREQ_ADJUST)
goto out;
max_freq = (
policy->cpuinfo.max_freq *
(100 - reduction_pctg(policy->cpu) * 20)
) / 100;
cpufreq_verify_within_limits(policy, 0, max_freq);
out:
return 0;
}
static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
.notifier_call = acpi_thermal_cpufreq_notifier,
};
static int cpufreq_get_max_state(unsigned int cpu)
{
if (!cpu_has_cpufreq(cpu))
return 0;
return CPUFREQ_THERMAL_MAX_STEP;
}
static int cpufreq_get_cur_state(unsigned int cpu)
{
if (!cpu_has_cpufreq(cpu))
return 0;
return reduction_pctg(cpu);
}
static int cpufreq_set_cur_state(unsigned int cpu, int state)
{
int i;
if (!cpu_has_cpufreq(cpu))
return 0;
reduction_pctg(cpu) = state;
/*
* Update all the CPUs in the same package because they all
* contribute to the temperature and often share the same
* frequency.
*/
for_each_online_cpu(i) {
if (topology_physical_package_id(i) ==
topology_physical_package_id(cpu))
cpufreq_update_policy(i);
}
return 0;
}
void acpi_thermal_cpufreq_init(void)
{
int i;
i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
CPUFREQ_POLICY_NOTIFIER);
if (!i)
acpi_thermal_cpufreq_is_init = 1;
}
void acpi_thermal_cpufreq_exit(void)
{
if (acpi_thermal_cpufreq_is_init)
cpufreq_unregister_notifier
(&acpi_thermal_cpufreq_notifier_block,
CPUFREQ_POLICY_NOTIFIER);
acpi_thermal_cpufreq_is_init = 0;
}
#else /* ! CONFIG_CPU_FREQ */
static int cpufreq_get_max_state(unsigned int cpu)
{
return 0;
}
static int cpufreq_get_cur_state(unsigned int cpu)
{
return 0;
}
static int cpufreq_set_cur_state(unsigned int cpu, int state)
{
return 0;
}
#endif
/* thermal cooling device callbacks */
static int acpi_processor_max_state(struct acpi_processor *pr)
{
int max_state = 0;
/*
* There exists four states according to
* cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
*/
max_state += cpufreq_get_max_state(pr->id);
if (pr->flags.throttling)
max_state += (pr->throttling.state_count -1);
return max_state;
}
static int
processor_get_max_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
struct acpi_device *device = cdev->devdata;
struct acpi_processor *pr;
if (!device)
return -EINVAL;
pr = acpi_driver_data(device);
if (!pr)
return -EINVAL;
*state = acpi_processor_max_state(pr);
return 0;
}
static int
processor_get_cur_state(struct thermal_cooling_device *cdev,
unsigned long *cur_state)
{
struct acpi_device *device = cdev->devdata;
struct acpi_processor *pr;
if (!device)
return -EINVAL;
pr = acpi_driver_data(device);
if (!pr)
return -EINVAL;
*cur_state = cpufreq_get_cur_state(pr->id);
if (pr->flags.throttling)
*cur_state += pr->throttling.state;
return 0;
}
static int
processor_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)
{
struct acpi_device *device = cdev->devdata;
struct acpi_processor *pr;
int result = 0;
int max_pstate;
if (!device)
return -EINVAL;
pr = acpi_driver_data(device);
if (!pr)
return -EINVAL;
max_pstate = cpufreq_get_max_state(pr->id);
if (state > acpi_processor_max_state(pr))
return -EINVAL;
if (state <= max_pstate) {
if (pr->flags.throttling && pr->throttling.state)
result = acpi_processor_set_throttling(pr, 0, false);
cpufreq_set_cur_state(pr->id, state);
} else {
cpufreq_set_cur_state(pr->id, max_pstate);
result = acpi_processor_set_throttling(pr,
state - max_pstate, false);
}
return result;
}
const struct thermal_cooling_device_ops processor_cooling_ops = {
.get_max_state = processor_get_max_state,
.get_cur_state = processor_get_cur_state,
.set_cur_state = processor_set_cur_state,
};