linux_dsm_epyc7002/arch/powerpc/platforms/cell/cpufreq_spudemand.c
Thomas Gleixner de6cc6515a treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 153
Based on 1 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 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 you should have received a
  copy of the gnu general public license along with this program if
  not write to the free software foundation inc 675 mass ave cambridge
  ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 77 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.837555891@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

156 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* spu aware cpufreq governor for the cell processor
*
* © Copyright IBM Corporation 2006-2008
*
* Author: Christian Krafft <krafft@de.ibm.com>
*/
#include <linux/cpufreq.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>
#include <asm/machdep.h>
#include <asm/spu.h>
#define POLL_TIME 100000 /* in µs */
#define EXP 753 /* exp(-1) in fixed-point */
struct spu_gov_info_struct {
unsigned long busy_spus; /* fixed-point */
struct cpufreq_policy *policy;
struct delayed_work work;
unsigned int poll_int; /* µs */
};
static DEFINE_PER_CPU(struct spu_gov_info_struct, spu_gov_info);
static int calc_freq(struct spu_gov_info_struct *info)
{
int cpu;
int busy_spus;
cpu = info->policy->cpu;
busy_spus = atomic_read(&cbe_spu_info[cpu_to_node(cpu)].busy_spus);
info->busy_spus = calc_load(info->busy_spus, EXP, busy_spus * FIXED_1);
pr_debug("cpu %d: busy_spus=%d, info->busy_spus=%ld\n",
cpu, busy_spus, info->busy_spus);
return info->policy->max * info->busy_spus / FIXED_1;
}
static void spu_gov_work(struct work_struct *work)
{
struct spu_gov_info_struct *info;
int delay;
unsigned long target_freq;
info = container_of(work, struct spu_gov_info_struct, work.work);
/* after cancel_delayed_work_sync we unset info->policy */
BUG_ON(info->policy == NULL);
target_freq = calc_freq(info);
__cpufreq_driver_target(info->policy, target_freq, CPUFREQ_RELATION_H);
delay = usecs_to_jiffies(info->poll_int);
schedule_delayed_work_on(info->policy->cpu, &info->work, delay);
}
static void spu_gov_init_work(struct spu_gov_info_struct *info)
{
int delay = usecs_to_jiffies(info->poll_int);
INIT_DEFERRABLE_WORK(&info->work, spu_gov_work);
schedule_delayed_work_on(info->policy->cpu, &info->work, delay);
}
static void spu_gov_cancel_work(struct spu_gov_info_struct *info)
{
cancel_delayed_work_sync(&info->work);
}
static int spu_gov_start(struct cpufreq_policy *policy)
{
unsigned int cpu = policy->cpu;
struct spu_gov_info_struct *info = &per_cpu(spu_gov_info, cpu);
struct spu_gov_info_struct *affected_info;
int i;
if (!cpu_online(cpu)) {
printk(KERN_ERR "cpu %d is not online\n", cpu);
return -EINVAL;
}
if (!policy->cur) {
printk(KERN_ERR "no cpu specified in policy\n");
return -EINVAL;
}
/* initialize spu_gov_info for all affected cpus */
for_each_cpu(i, policy->cpus) {
affected_info = &per_cpu(spu_gov_info, i);
affected_info->policy = policy;
}
info->poll_int = POLL_TIME;
/* setup timer */
spu_gov_init_work(info);
return 0;
}
static void spu_gov_stop(struct cpufreq_policy *policy)
{
unsigned int cpu = policy->cpu;
struct spu_gov_info_struct *info = &per_cpu(spu_gov_info, cpu);
int i;
/* cancel timer */
spu_gov_cancel_work(info);
/* clean spu_gov_info for all affected cpus */
for_each_cpu (i, policy->cpus) {
info = &per_cpu(spu_gov_info, i);
info->policy = NULL;
}
}
static struct cpufreq_governor spu_governor = {
.name = "spudemand",
.start = spu_gov_start,
.stop = spu_gov_stop,
.owner = THIS_MODULE,
};
/*
* module init and destoy
*/
static int __init spu_gov_init(void)
{
int ret;
ret = cpufreq_register_governor(&spu_governor);
if (ret)
printk(KERN_ERR "registration of governor failed\n");
return ret;
}
static void __exit spu_gov_exit(void)
{
cpufreq_unregister_governor(&spu_governor);
}
module_init(spu_gov_init);
module_exit(spu_gov_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");