Hey Amit, I was able to use your code on an i.MX6Q thermal implementation and it seemed to work pretty well. Thanks for adding this. A couple of comments below. On Tue, Dec 13, 2011 at 9:13 AM, Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx> wrote: > This patch adds support for generic cpu thermal cooling low level > implementations using frequency scaling and cpuhotplugg currently. > Different cpu related cooling devices can be registered by the > user and the binding of these cooling devices to the corresponding > trip points can be easily done as the registration API's return the > cooling device pointer. > > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx> > --- > Documentation/thermal/cpu-cooling-api.txt | 52 +++++ > drivers/thermal/Kconfig | 11 + > drivers/thermal/Makefile | 1 + > drivers/thermal/cpu_cooling.c | 302 +++++++++++++++++++++++++++++ > include/linux/cpu_cooling.h | 45 +++++ > 5 files changed, 411 insertions(+), 0 deletions(-) > create mode 100644 Documentation/thermal/cpu-cooling-api.txt > create mode 100644 drivers/thermal/cpu_cooling.c > create mode 100644 include/linux/cpu_cooling.h > > diff --git a/Documentation/thermal/cpu-cooling-api.txt b/Documentation/thermal/cpu-cooling-api.txt > new file mode 100644 > index 0000000..d30b4f2 > --- /dev/null > +++ b/Documentation/thermal/cpu-cooling-api.txt > @@ -0,0 +1,52 @@ > +CPU cooling api's How To > +=================================== > + > +Written by Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx> > + > +Updated: 13 Dec 2011 > + > +Copyright (c) 2011 Samsung Electronics Co., Ltd(http://www.samsung.com) > + > +0. Introduction > + > +The generic cpu cooling(freq clipping, cpuhotplug) provides > +registration/unregistration api's to the user. The binding of the cooling > +devices to the trip types is left for the user. The registration api's returns > +the cooling device pointer. > + > +1. cpufreq cooling api's > + > +1.1 cpufreq registration api's > +1.1.1 struct thermal_cooling_device *cpufreq_cooling_register( > + struct freq_pctg_table *tab_ptr, unsigned int tab_size, > + const struct cpumask *mask_val) > + > + This interface function registers the cpufreq cooling device with the name > + "thermal-cpufreq". > + > + tab_ptr: The table containing the percentage of frequency to be clipped for > + each cooling state. > + .freq_clip_pctg[NR_CPUS]:Percentage of frequency to be clipped for each > + cpu. > + .polling_interval: polling interval for this cooling state. > + tab_size: the total number of cooling state. > + mask_val: all the allowed cpu's where frequency clipping can happen. > + > +1.1.2 void cpufreq_cooling_unregister(void) > + > + This interface function unregisters the "thermal-cpufreq" cooling device. > + > + > +1.2 cpuhotplug registration api's > + > +1.2.1 struct thermal_cooling_device *cpuhotplug_cooling_register( > + const struct cpumask *mask_val) > + > + This interface function registers the cpuhotplug cooling device with the name > + "thermal-cpuhotplug". > + > + mask_val: all the allowed cpu's which can be hotplugged out. > + > +1.1.2 void cpuhotplug_cooling_unregister(void) > + > + This interface function unregisters the "thermal-cpuhotplug" cooling device. > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index f7f71b2..298c1cd 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -18,3 +18,14 @@ config THERMAL_HWMON > depends on THERMAL > depends on HWMON=y || HWMON=THERMAL > default y > + > +config CPU_THERMAL > + bool "generic cpu cooling support" > + depends on THERMAL > + help > + This implements the generic cpu cooling mechanism through frequency > + reduction, cpu hotplug and any other ways of reducing temperature. An > + ACPI version of this already exists(drivers/acpi/processor_thermal.c). > + This will be useful for platforms using the generic thermal interface > + and not the ACPI interface. > + If you want this support, you should say Y or M here. > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index 31108a0..655cbc4 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -3,3 +3,4 @@ > # > > obj-$(CONFIG_THERMAL) += thermal_sys.o > +obj-$(CONFIG_CPU_THERMAL) += cpu_cooling.o > diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c > new file mode 100644 > index 0000000..cdd148c > --- /dev/null > +++ b/drivers/thermal/cpu_cooling.c > @@ -0,0 +1,302 @@ > +/* > + * linux/drivers/thermal/cpu_cooling.c > + * > + * Copyright (C) 2011 Samsung Electronics Co., Ltd(http://www.samsung.com) > + * Copyright (C) 2011 Amit Daniel <amit.kachhap@xxxxxxxxxx> > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + * 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; version 2 of the License. > + * > + * 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., > + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + */ > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/thermal.h> > +#include <linux/platform_device.h> > +#include <linux/cpufreq.h> > +#include <linux/err.h> > +#include <linux/slab.h> > +#include <linux/cpu.h> > +#include <linux/cpu_cooling.h> > + > +#ifdef CONFIG_CPU_FREQ > +struct cpufreq_cooling_device { > + struct thermal_cooling_device *cool_dev; > + struct freq_pctg_table *tab_ptr; > + unsigned int tab_size; > + unsigned int cpufreq_state; > + const struct cpumask *allowed_cpus; > +}; > + > +static struct cpufreq_cooling_device *cpufreq_device; > + > +/*Below codes defines functions to be used for cpufreq as cooling device*/ > +static bool is_cpufreq_valid(int cpu) > +{ > + struct cpufreq_policy policy; > + if (!cpufreq_get_policy(&policy, cpu)) > + return true; > + return false; > +} > + > +static int cpufreq_apply_cooling(int cooling_state) > +{ > + int cpuid, this_cpu = smp_processor_id(); > + > + if (!is_cpufreq_valid(this_cpu)) > + return 0; > + > + if (cooling_state > cpufreq_device->tab_size) > + return -EINVAL; > + > + /*Check if last cooling level is same as current cooling level*/ > + if (cpufreq_device->cpufreq_state == cooling_state) > + return 0; > + > + cpufreq_device->cpufreq_state = cooling_state; > + > + for_each_cpu(cpuid, cpufreq_device->allowed_cpus) { > + if (is_cpufreq_valid(cpuid)) > + cpufreq_update_policy(cpuid); > + } > + > + return 0; > +} > + > +static int thermal_cpufreq_notifier(struct notifier_block *nb, > + unsigned long event, void *data) > +{ > + struct cpufreq_policy *policy = data; > + struct freq_pctg_table *th_table; > + unsigned long max_freq = 0; > + unsigned int cpu = policy->cpu, th_pctg = 0, level; > + > + if (event != CPUFREQ_ADJUST) > + return 0; > + > + level = cpufreq_device->cpufreq_state; > + > + if (level > 0) { > + th_table = > + &(cpufreq_device->tab_ptr[level - 1]); > + th_pctg = th_table->freq_clip_pctg[cpu]; > + } > + > + max_freq = > + (policy->cpuinfo.max_freq * (100 - th_pctg)) / 100; > + > + cpufreq_verify_within_limits(policy, 0, max_freq); > + > + return 0; > +} > + > +/* > + * cpufreq cooling device callback functions > + */ > +static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, > + unsigned long *state) > +{ > + *state = cpufreq_device->tab_size; > + return 0; > +} > + > +static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, > + unsigned long *state) > +{ > + *state = cpufreq_device->cpufreq_state; > + return 0; > +} > + > +/*This cooling may be as PASSIVE/STATE_ACTIVE type*/ > +static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, > + unsigned long state) > +{ > + cpufreq_apply_cooling(state); > + return 0; > +} > + > +/* bind cpufreq callbacks to cpufreq cooling device */ > +static struct thermal_cooling_device_ops cpufreq_cooling_ops = { > + .get_max_state = cpufreq_get_max_state, > + .get_cur_state = cpufreq_get_cur_state, > + .set_cur_state = cpufreq_set_cur_state, > +}; > + > +static struct notifier_block thermal_cpufreq_notifier_block = { > + .notifier_call = thermal_cpufreq_notifier, > +}; > + > +struct thermal_cooling_device *cpufreq_cooling_register( > + struct freq_pctg_table *tab_ptr, unsigned int tab_size, > + const struct cpumask *mask_val) > +{ > + struct thermal_cooling_device *cool_dev; > + > + if (tab_ptr == NULL || tab_size == 0) > + return ERR_PTR(-EINVAL); > + > + cpufreq_device = > + kzalloc(sizeof(struct cpufreq_cooling_device), GFP_KERNEL); > + > + if (!cpufreq_device) > + return ERR_PTR(-ENOMEM); > + > + cool_dev = thermal_cooling_device_register("thermal-cpufreq", NULL, > + &cpufreq_cooling_ops); > + if (!cool_dev) { > + kfree(cpufreq_device); > + return ERR_PTR(-EINVAL); > + } > + > + cpufreq_device->tab_ptr = tab_ptr; > + cpufreq_device->tab_size = tab_size; > + cpufreq_device->cool_dev = cool_dev; > + cpufreq_device->allowed_cpus = mask_val; > + > + cpufreq_register_notifier(&thermal_cpufreq_notifier_block, > + CPUFREQ_POLICY_NOTIFIER); > + return cool_dev; > +} > +EXPORT_SYMBOL(cpufreq_cooling_register); > + > +void cpufreq_cooling_unregister(void) > +{ > + cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, > + CPUFREQ_POLICY_NOTIFIER); > + thermal_cooling_device_unregister(cpufreq_device->cool_dev); > + kfree(cpufreq_device); > +} > +EXPORT_SYMBOL(cpufreq_cooling_unregister); > +#else /*!CONFIG_CPU_FREQ*/ > +struct thermal_cooling_device *cpufreq_cooling_register( > + struct freq_pctg_table *tab_ptr, unsigned int tab_size) Need to add the "const struct cpumask *mask_val" parameter to this function like it's used above and prototyped in the heard or else it causes a build error when building without CONFIG_CPU_FREQ defined. > +{ > + return NULL; > +} > +EXPORT_SYMBOL(cpufreq_cooling_register); > +void cpufreq_cooling_unregister(void) > +{ > + return; > +} > +EXPORT_SYMBOL(cpufreq_cooling_unregister); > +#endif /*CONFIG_CPU_FREQ*/ > + > +#ifdef CONFIG_HOTPLUG_CPU > + > +struct hotplug_cooling_device { > + struct thermal_cooling_device *cool_dev; > + unsigned int hotplug_state; > + const struct cpumask *allowed_cpus; > +}; > +static struct hotplug_cooling_device *hotplug_device; > + > +/* > + * cpu hotplug cooling device callback functions > + */ > +static int cpuhotplug_get_max_state(struct thermal_cooling_device *cdev, > + unsigned long *state) > +{ > + *state = 1; > + return 0; > +} > + > +static int cpuhotplug_get_cur_state(struct thermal_cooling_device *cdev, > + unsigned long *state) > +{ > + /*This cooling device may be of type ACTIVE, so state field > + can be 0 or 1*/ > + *state = hotplug_device->hotplug_state; > + return 0; > +} > + > +/*This cooling may be as PASSIVE/STATE_ACTIVE type*/ > +static int cpuhotplug_set_cur_state(struct thermal_cooling_device *cdev, > + unsigned long state) > +{ > + int cpuid, this_cpu = smp_processor_id(); > + > + if (hotplug_device->hotplug_state == state) > + return 0; > + > + /*This cooling device may be of type ACTIVE, so state field > + can be 0 or 1*/ > + if (state == 1) { > + for_each_cpu(cpuid, hotplug_device->allowed_cpus) { > + if (cpu_online(cpuid) && (cpuid != this_cpu)) > + cpu_down(cpuid); > + } > + } else if (state == 0) { > + for_each_cpu(cpuid, hotplug_device->allowed_cpus) { > + if (!cpu_online(cpuid) && (cpuid != this_cpu)) > + cpu_up(cpuid); > + } > + } else > + return -EINVAL; > + I don't like how ACTIVE does not have available notification callbacks like HOT and CRITICAL do. Perhaps I fail to grasp why they aren't there but besides just applying a cooling device, one might want to do something else as well upon hitting these trip points. So that said, it might be nice to add a notification to STATE_ACTIVE as well. > + hotplug_device->hotplug_state = state; > + > + return 0; > +} > +/* bind hotplug callbacks to cpu hotplug cooling device */ > +static struct thermal_cooling_device_ops cpuhotplug_cooling_ops = { > + .get_max_state = cpuhotplug_get_max_state, > + .get_cur_state = cpuhotplug_get_cur_state, > + .set_cur_state = cpuhotplug_set_cur_state, > +}; > + > +struct thermal_cooling_device *cpuhotplug_cooling_register( > + const struct cpumask *mask_val) > +{ > + struct thermal_cooling_device *cool_dev; > + > + hotplug_device = > + kzalloc(sizeof(struct hotplug_cooling_device), GFP_KERNEL); > + > + if (!hotplug_device) > + return ERR_PTR(-ENOMEM); > + > + cool_dev = thermal_cooling_device_register("thermal-cpuhotplug", NULL, > + &cpuhotplug_cooling_ops); > + if (!cool_dev) { > + kfree(hotplug_device); > + return ERR_PTR(-EINVAL); > + } > + > + hotplug_device->cool_dev = cool_dev; > + hotplug_device->hotplug_state = 0; > + hotplug_device->allowed_cpus = mask_val; > + > + return cool_dev; > +} > +EXPORT_SYMBOL(cpuhotplug_cooling_register); > + > +void cpuhotplug_cooling_unregister(void) > +{ > + thermal_cooling_device_unregister(hotplug_device->cool_dev); > + kfree(hotplug_device); > +} > +EXPORT_SYMBOL(cpuhotplug_cooling_unregister); > +#else /*!CONFIG_HOTPLUG_CPU*/ > +struct thermal_cooling_device *cpuhotplug_cooling_register( > + const struct cpumask *mask_val) > +{ > + return NULL; > +} > +EXPORT_SYMBOL(cpuhotplug_cooling_register); > +void cpuhotplug_cooling_unregister(void) > +{ > + return; > +} > +EXPORT_SYMBOL(cpuhotplug_cooling_unregister); > +#endif /*CONFIG_HOTPLUG_CPU*/ > diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h > new file mode 100644 > index 0000000..0c57375 > --- /dev/null > +++ b/include/linux/cpu_cooling.h > @@ -0,0 +1,45 @@ > +/* > + * linux/include/linux/cpu_cooling.h > + * > + * Copyright (C) 2011 Samsung Electronics Co., Ltd(http://www.samsung.com) > + * Copyright (C) 2011 Amit Daniel <amit.kachhap@xxxxxxxxxx> > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + * 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; version 2 of the License. > + * > + * 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., > + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + */ > + > +#ifndef __CPU_COOLING_H__ > +#define __CPU_COOLING_H__ > + > +#include <linux/thermal.h> > + > +struct freq_pctg_table { > + unsigned int freq_clip_pctg[NR_CPUS]; > + unsigned int polling_interval; > +}; > + > +extern struct thermal_cooling_device *cpufreq_cooling_register( > + struct freq_pctg_table *tab_ptr, unsigned int tab_size, > + const struct cpumask *mask_val); > + > +extern void cpufreq_cooling_unregister(void); > + > +extern struct thermal_cooling_device *cpuhotplug_cooling_register( > + const struct cpumask *mask_val); > + > +extern void cpuhotplug_cooling_unregister(void); > + > +#endif /* __CPU_COOLING_H__ */ > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
