2008-07-15 19:51:43 +00:00
|
|
|
/*
|
|
|
|
* spu aware cpufreq governor for the cell processor
|
|
|
|
*
|
|
|
|
* © Copyright IBM Corporation 2006-2008
|
|
|
|
*
|
|
|
|
* Author: Christian Krafft <krafft@de.ibm.com>
|
|
|
|
*
|
|
|
|
* 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.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <linux/cpufreq.h>
|
|
|
|
#include <linux/sched.h>
|
|
|
|
#include <linux/timer.h>
|
|
|
|
#include <linux/workqueue.h>
|
|
|
|
#include <asm/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 struct workqueue_struct *kspugov_wq;
|
|
|
|
|
|
|
|
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);
|
|
|
|
|
|
|
|
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);
|
|
|
|
queue_delayed_work_on(info->policy->cpu, kspugov_wq, &info->work, delay);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void spu_gov_init_work(struct spu_gov_info_struct *info)
|
|
|
|
{
|
|
|
|
int delay = usecs_to_jiffies(info->poll_int);
|
|
|
|
INIT_DELAYED_WORK_DEFERRABLE(&info->work, spu_gov_work);
|
|
|
|
queue_delayed_work_on(info->policy->cpu, kspugov_wq, &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_govern(struct cpufreq_policy *policy, unsigned int event)
|
|
|
|
{
|
|
|
|
unsigned int cpu = policy->cpu;
|
|
|
|
struct spu_gov_info_struct *info, *affected_info;
|
|
|
|
int i;
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
info = &per_cpu(spu_gov_info, cpu);
|
|
|
|
|
|
|
|
switch (event) {
|
|
|
|
case CPUFREQ_GOV_START:
|
|
|
|
if (!cpu_online(cpu)) {
|
|
|
|
printk(KERN_ERR "cpu %d is not online\n", cpu);
|
|
|
|
ret = -EINVAL;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!policy->cur) {
|
|
|
|
printk(KERN_ERR "no cpu specified in policy\n");
|
|
|
|
ret = -EINVAL;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* initialize spu_gov_info for all affected cpus */
|
2009-01-12 00:22:01 +00:00
|
|
|
for_each_cpu(i, policy->cpus) {
|
2008-07-15 19:51:43 +00:00
|
|
|
affected_info = &per_cpu(spu_gov_info, i);
|
|
|
|
affected_info->policy = policy;
|
|
|
|
}
|
|
|
|
|
|
|
|
info->poll_int = POLL_TIME;
|
|
|
|
|
|
|
|
/* setup timer */
|
|
|
|
spu_gov_init_work(info);
|
|
|
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
case CPUFREQ_GOV_STOP:
|
|
|
|
/* cancel timer */
|
|
|
|
spu_gov_cancel_work(info);
|
|
|
|
|
|
|
|
/* clean spu_gov_info for all affected cpus */
|
2009-01-12 00:22:01 +00:00
|
|
|
for_each_cpu (i, policy->cpus) {
|
2008-07-15 19:51:43 +00:00
|
|
|
info = &per_cpu(spu_gov_info, i);
|
|
|
|
info->policy = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct cpufreq_governor spu_governor = {
|
|
|
|
.name = "spudemand",
|
|
|
|
.governor = spu_gov_govern,
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
};
|
|
|
|
|
|
|
|
/*
|
|
|
|
* module init and destoy
|
|
|
|
*/
|
|
|
|
|
|
|
|
static int __init spu_gov_init(void)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
kspugov_wq = create_workqueue("kspugov");
|
|
|
|
if (!kspugov_wq) {
|
|
|
|
printk(KERN_ERR "creation of kspugov failed\n");
|
|
|
|
ret = -EFAULT;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
ret = cpufreq_register_governor(&spu_governor);
|
|
|
|
if (ret) {
|
|
|
|
printk(KERN_ERR "registration of governor failed\n");
|
|
|
|
destroy_workqueue(kspugov_wq);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
out:
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit spu_gov_exit(void)
|
|
|
|
{
|
|
|
|
cpufreq_unregister_governor(&spu_governor);
|
|
|
|
destroy_workqueue(kspugov_wq);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
module_init(spu_gov_init);
|
|
|
|
module_exit(spu_gov_exit);
|
|
|
|
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
|
|
|
|
|