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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/devfreq/governor_simpleondemand.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/devfreq/governor_simpleondemand.c')
-rw-r--r-- | kernel/drivers/devfreq/governor_simpleondemand.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/kernel/drivers/devfreq/governor_simpleondemand.c b/kernel/drivers/devfreq/governor_simpleondemand.c new file mode 100644 index 000000000..0720ba84c --- /dev/null +++ b/kernel/drivers/devfreq/governor_simpleondemand.c @@ -0,0 +1,147 @@ +/* + * linux/drivers/devfreq/governor_simpleondemand.c + * + * Copyright (C) 2011 Samsung Electronics + * MyungJoo Ham <myungjoo.ham@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/devfreq.h> +#include <linux/math64.h> +#include "governor.h" + +/* Default constants for DevFreq-Simple-Ondemand (DFSO) */ +#define DFSO_UPTHRESHOLD (90) +#define DFSO_DOWNDIFFERENCTIAL (5) +static int devfreq_simple_ondemand_func(struct devfreq *df, + unsigned long *freq) +{ + struct devfreq_dev_status stat; + int err = df->profile->get_dev_status(df->dev.parent, &stat); + unsigned long long a, b; + unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD; + unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL; + struct devfreq_simple_ondemand_data *data = df->data; + unsigned long max = (df->max_freq) ? df->max_freq : UINT_MAX; + + if (err) + return err; + + if (data) { + if (data->upthreshold) + dfso_upthreshold = data->upthreshold; + if (data->downdifferential) + dfso_downdifferential = data->downdifferential; + } + if (dfso_upthreshold > 100 || + dfso_upthreshold < dfso_downdifferential) + return -EINVAL; + + /* Assume MAX if it is going to be divided by zero */ + if (stat.total_time == 0) { + *freq = max; + return 0; + } + + /* Prevent overflow */ + if (stat.busy_time >= (1 << 24) || stat.total_time >= (1 << 24)) { + stat.busy_time >>= 7; + stat.total_time >>= 7; + } + + /* Set MAX if it's busy enough */ + if (stat.busy_time * 100 > + stat.total_time * dfso_upthreshold) { + *freq = max; + return 0; + } + + /* Set MAX if we do not know the initial frequency */ + if (stat.current_frequency == 0) { + *freq = max; + return 0; + } + + /* Keep the current frequency */ + if (stat.busy_time * 100 > + stat.total_time * (dfso_upthreshold - dfso_downdifferential)) { + *freq = stat.current_frequency; + return 0; + } + + /* Set the desired frequency based on the load */ + a = stat.busy_time; + a *= stat.current_frequency; + b = div_u64(a, stat.total_time); + b *= 100; + b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2)); + *freq = (unsigned long) b; + + if (df->min_freq && *freq < df->min_freq) + *freq = df->min_freq; + if (df->max_freq && *freq > df->max_freq) + *freq = df->max_freq; + + return 0; +} + +static int devfreq_simple_ondemand_handler(struct devfreq *devfreq, + unsigned int event, void *data) +{ + switch (event) { + case DEVFREQ_GOV_START: + devfreq_monitor_start(devfreq); + break; + + case DEVFREQ_GOV_STOP: + devfreq_monitor_stop(devfreq); + break; + + case DEVFREQ_GOV_INTERVAL: + devfreq_interval_update(devfreq, (unsigned int *)data); + break; + + case DEVFREQ_GOV_SUSPEND: + devfreq_monitor_suspend(devfreq); + break; + + case DEVFREQ_GOV_RESUME: + devfreq_monitor_resume(devfreq); + break; + + default: + break; + } + + return 0; +} + +static struct devfreq_governor devfreq_simple_ondemand = { + .name = "simple_ondemand", + .get_target_freq = devfreq_simple_ondemand_func, + .event_handler = devfreq_simple_ondemand_handler, +}; + +static int __init devfreq_simple_ondemand_init(void) +{ + return devfreq_add_governor(&devfreq_simple_ondemand); +} +subsys_initcall(devfreq_simple_ondemand_init); + +static void __exit devfreq_simple_ondemand_exit(void) +{ + int ret; + + ret = devfreq_remove_governor(&devfreq_simple_ondemand); + if (ret) + pr_err("%s: failed remove governor %d\n", __func__, ret); + + return; +} +module_exit(devfreq_simple_ondemand_exit); +MODULE_LICENSE("GPL"); |