diff options
Diffstat (limited to 'drivers/thermal/cpu_cooling.c')
| -rw-r--r-- | drivers/thermal/cpu_cooling.c | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c new file mode 100644 index 000000000000..429f4fde8f32 --- /dev/null +++ b/drivers/thermal/cpu_cooling.c @@ -0,0 +1,571 @@ +/* + * linux/drivers/thermal/cpu_cooling.c + * + * Copyright (C) 2011 Samsung Electronics Co., Ltd(http://www.samsung.com) + * Copyright (C) 2011 Amit Daniel <amit.kachhap@linaro.org> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * 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> + +struct cpufreq_cooling_device { + int id; + struct thermal_cooling_device *cool_dev; + struct freq_clip_table *tab_ptr; + unsigned int tab_size; + unsigned int cpufreq_cur_state; + unsigned int cpufreq_max_state; + const struct cpumask *allowed_cpus; + enum thermal_trip_type type; + struct list_head node; +}; + +static LIST_HEAD(cooling_cpufreq_list); +static DEFINE_MUTEX(cooling_cpufreq_lock); +static DEFINE_IDR(cpufreq_idr); +static DEFINE_PER_CPU(unsigned int, max_policy_freq); +static struct freq_clip_table *notify_table; +static int notify_state; +static struct cpufreq_cooling_device *notify_dev; + +struct hotplug_cooling_device { + int id; + struct thermal_cooling_device *cool_dev; + unsigned int hotplug_state; + const struct cpumask *allowed_cpus; + struct list_head node; +}; + +static LIST_HEAD(cooling_cpuhotplug_list); +static DEFINE_MUTEX(cooling_cpuhotplug_lock); +static DEFINE_IDR(cpuhotplug_idr); + +static BLOCKING_NOTIFIER_HEAD(cputherm_state_notifier_list); + +static int get_idr(struct idr *idr, struct mutex *lock, int *id) +{ + int err; +again: + if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0)) + return -ENOMEM; + + if (lock) + mutex_lock(lock); + err = idr_get_new(idr, NULL, id); + if (lock) + mutex_unlock(lock); + if (unlikely(err == -EAGAIN)) + goto again; + else if (unlikely(err)) + return err; + + *id = *id & MAX_ID_MASK; + return 0; +} + +static void release_idr(struct idr *idr, struct mutex *lock, int id) +{ + if (lock) + mutex_lock(lock); + idr_remove(idr, id); + if (lock) + mutex_unlock(lock); +} + +int cputherm_register_notifier(struct notifier_block *nb, unsigned int list) +{ + int ret = 0; + + switch (list) { + case CPUFREQ_COOLING_TYPE: + case CPUHOTPLUG_COOLING_TYPE: + ret = blocking_notifier_chain_register( + &cputherm_state_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + return ret; +} +EXPORT_SYMBOL(cputherm_register_notifier); + +int cputherm_unregister_notifier(struct notifier_block *nb, unsigned int list) +{ + int ret = 0; + + switch (list) { + case CPUFREQ_COOLING_TYPE: + case CPUHOTPLUG_COOLING_TYPE: + ret = blocking_notifier_chain_unregister( + &cputherm_state_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + return ret; +} +EXPORT_SYMBOL(cputherm_unregister_notifier); + +/*Below codes defines functions to be used for cpufreq as cooling device*/ +static bool is_cpufreq_valid(int cpu) +{ + struct cpufreq_policy policy; + return !cpufreq_get_policy(&policy, cpu) ? true : false; +} + +static int get_freq_state_count(struct cpufreq_cooling_device *cpufreq_dev) +{ + struct cpufreq_frequency_table *table; + int i = 0, cpu, max_count = 0; + + if (cpufreq_dev->type != THERMAL_TRIP_PASSIVE) + return cpufreq_dev->cpufreq_max_state; + + for_each_cpu(cpu, cpufreq_dev->allowed_cpus) { + table = cpufreq_frequency_get_table(cpu); + i = 0; + if (table) + while (table[i].frequency != CPUFREQ_TABLE_END) + i++; + if (i > max_count) + max_count = i; + } + return max_count; +} + +static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, + unsigned long cooling_state) +{ + unsigned int event, cpuid; + struct freq_clip_table *th_table; + + if (cooling_state > get_freq_state_count(cpufreq_device)) + return -EINVAL; + + cpufreq_device->cpufreq_cur_state = cooling_state; + + /*cpufreq thermal notifier uses this cpufreq device pointer*/ + notify_state = cooling_state; + notify_dev = cpufreq_device; + + if (notify_state > 0 && cpufreq_device->type != THERMAL_TRIP_PASSIVE) { + th_table = &(cpufreq_device->tab_ptr[cooling_state - 1]); + memcpy(notify_table, th_table, sizeof(struct freq_clip_table)); + event = CPUFREQ_COOLING_TYPE; + blocking_notifier_call_chain(&cputherm_state_notifier_list, + event, notify_table); + } + + for_each_cpu(cpuid, cpufreq_device->allowed_cpus) { + if (is_cpufreq_valid(cpuid)) + cpufreq_update_policy(cpuid); + } + + notify_state = -1; + notify_dev = NULL; + + return 0; +} + +static int cpufreq_thermal_notifier(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct cpufreq_policy *policy = data; + unsigned long max_freq = 0; + struct cpufreq_frequency_table *table; + int ret; + + if ((event != CPUFREQ_ADJUST) || (notify_state == -1)) + return 0; + + if (notify_state > 0) { + if (notify_dev->type == THERMAL_TRIP_PASSIVE) { + table = cpufreq_frequency_get_table(policy->cpu); + ret = get_freq_state_count(notify_dev); + if (notify_state < ret) + max_freq = table[notify_state - 1].frequency; + } else { + max_freq = notify_table->freq_clip_max; + } + + if (per_cpu(max_policy_freq, policy->cpu) == 0) + per_cpu(max_policy_freq, policy->cpu) = policy->max; + } else { + if (per_cpu(max_policy_freq, policy->cpu) != 0) { + max_freq = per_cpu(max_policy_freq, policy->cpu); + per_cpu(max_policy_freq, policy->cpu) = 0; + } else { + max_freq = policy->max; + } + } + + /* Never exceed user_policy.max*/ + if (max_freq > policy->user_policy.max) + max_freq = policy->user_policy.max; + + if (policy->max != max_freq) + 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) +{ + int ret = -EINVAL; + struct cpufreq_cooling_device *cpufreq_device; + + mutex_lock(&cooling_cpufreq_lock); + list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { + if (cpufreq_device && cpufreq_device->cool_dev == cdev) { + *state = get_freq_state_count(cpufreq_device); + ret = 0; + break; + } + } + mutex_unlock(&cooling_cpufreq_lock); + return ret; +} + +static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + int ret = -EINVAL; + struct cpufreq_cooling_device *cpufreq_device; + + mutex_lock(&cooling_cpufreq_lock); + list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { + if (cpufreq_device && cpufreq_device->cool_dev == cdev) { + *state = cpufreq_device->cpufreq_cur_state; + ret = 0; + break; + } + } + mutex_unlock(&cooling_cpufreq_lock); + return ret; +} + +/*This cooling may be as PASSIVE/ACTIVE type*/ +static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, + unsigned long state) +{ + int ret = -EINVAL; + struct cpufreq_cooling_device *cpufreq_device; + + mutex_lock(&cooling_cpufreq_lock); + list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { + if (cpufreq_device && cpufreq_device->cool_dev == cdev) { + ret = 0; + break; + } + } + mutex_unlock(&cooling_cpufreq_lock); + + if (!ret) + ret = cpufreq_apply_cooling(cpufreq_device, state); + + return ret; +} + +/* 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 = cpufreq_thermal_notifier, +}; + +struct thermal_cooling_device *cpufreq_cooling_register( + struct freq_clip_table *tab_ptr, unsigned int tab_size, + const struct cpumask *mask_val, enum thermal_trip_type type) +{ + struct thermal_cooling_device *cool_dev; + struct cpufreq_cooling_device *cpufreq_dev = NULL; + unsigned int cpufreq_dev_count = 0; + char dev_name[THERMAL_NAME_LENGTH]; + int ret = 0, id = 0, i; + + if ((tab_ptr == NULL || tab_size == 0) && type != THERMAL_TRIP_PASSIVE) + return ERR_PTR(-EINVAL); + + if ((tab_ptr != NULL || tab_size != 0) && type == THERMAL_TRIP_PASSIVE) + return ERR_PTR(-EINVAL); + + list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) + cpufreq_dev_count++; + + cpufreq_dev = + kzalloc(sizeof(struct cpufreq_cooling_device), GFP_KERNEL); + + if (!cpufreq_dev) + return ERR_PTR(-ENOMEM); + + if (cpufreq_dev_count == 0) { + notify_table = kzalloc(sizeof(struct freq_clip_table), + GFP_KERNEL); + if (!notify_table) { + kfree(cpufreq_dev); + return ERR_PTR(-ENOMEM); + } + } + + cpufreq_dev->tab_ptr = tab_ptr; + cpufreq_dev->tab_size = tab_size; + cpufreq_dev->allowed_cpus = mask_val; + cpufreq_dev->type = type; + cpufreq_dev->cpufreq_max_state = 0; + + if (type != THERMAL_TRIP_PASSIVE) + cpufreq_dev->cpufreq_max_state = tab_size; + + /* Initialize all the tab_ptr->mask_val to the passed mask_val */ + for (i = 0; i < tab_size; i++) + ((struct freq_clip_table *)&tab_ptr[i])->mask_val = mask_val; + + ret = get_idr(&cpufreq_idr, &cooling_cpufreq_lock, &cpufreq_dev->id); + if (ret) { + kfree(cpufreq_dev); + return ERR_PTR(-EINVAL); + } + + sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id); + + cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev, + &cpufreq_cooling_ops); + if (!cool_dev) { + release_idr(&cpufreq_idr, &cooling_cpufreq_lock, + cpufreq_dev->id); + kfree(cpufreq_dev); + return ERR_PTR(-EINVAL); + } + cpufreq_dev->id = id; + cpufreq_dev->cool_dev = cool_dev; + mutex_lock(&cooling_cpufreq_lock); + list_add_tail(&cpufreq_dev->node, &cooling_cpufreq_list); + mutex_unlock(&cooling_cpufreq_lock); + + /*Register the notifier for first cpufreq cooling device*/ + if (cpufreq_dev_count == 0) + cpufreq_register_notifier(&thermal_cpufreq_notifier_block, + CPUFREQ_POLICY_NOTIFIER); + return cool_dev; +} +EXPORT_SYMBOL(cpufreq_cooling_register); + +void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) +{ + struct cpufreq_cooling_device *cpufreq_dev = NULL; + unsigned int cpufreq_dev_count = 0; + + mutex_lock(&cooling_cpufreq_lock); + list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) { + if (cpufreq_dev && cpufreq_dev->cool_dev == cdev) + break; + cpufreq_dev_count++; + } + + if (!cpufreq_dev || cpufreq_dev->cool_dev != cdev) { + mutex_unlock(&cooling_cpufreq_lock); + return; + } + + list_del(&cpufreq_dev->node); + mutex_unlock(&cooling_cpufreq_lock); + + /*Unregister the notifier for the last cpufreq cooling device*/ + if (cpufreq_dev_count == 1) { + cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, + CPUFREQ_POLICY_NOTIFIER); + kfree(notify_table); + } + + thermal_cooling_device_unregister(cpufreq_dev->cool_dev); + release_idr(&cpufreq_idr, &cooling_cpufreq_lock, cpufreq_dev->id); + kfree(cpufreq_dev); +} +EXPORT_SYMBOL(cpufreq_cooling_unregister); + +/* + * cpu hotplug cooling device callback functions + */ +static int cpuhotplug_get_max_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + int ret = -EINVAL; + struct hotplug_cooling_device *hotplug_dev; + + /* + * This cooling device may be of type ACTIVE, so state field can + * be 0 or 1 + */ + mutex_lock(&cooling_cpuhotplug_lock); + list_for_each_entry(hotplug_dev, &cooling_cpuhotplug_list, node) { + if (hotplug_dev && hotplug_dev->cool_dev == cdev) { + *state = 1; + ret = 0; + break; + } + } + mutex_unlock(&cooling_cpuhotplug_lock); + return ret; +} + +static int cpuhotplug_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + int ret = -EINVAL; + struct hotplug_cooling_device *hotplug_dev; + + mutex_lock(&cooling_cpuhotplug_lock); + list_for_each_entry(hotplug_dev, &cooling_cpuhotplug_list, node) { + if (hotplug_dev && hotplug_dev->cool_dev == cdev) { + *state = hotplug_dev->hotplug_state; + ret = 0; + break; + } + } + mutex_unlock(&cooling_cpuhotplug_lock); + return ret; +} + +/*This cooling may be as ACTIVE type*/ +static int cpuhotplug_set_cur_state(struct thermal_cooling_device *cdev, + unsigned long state) +{ + int cpuid, this_cpu = smp_processor_id(); + struct hotplug_cooling_device *hotplug_dev; + + mutex_lock(&cooling_cpuhotplug_lock); + list_for_each_entry(hotplug_dev, &cooling_cpuhotplug_list, node) + if (hotplug_dev && hotplug_dev->cool_dev == cdev) + break; + + mutex_unlock(&cooling_cpuhotplug_lock); + if (!hotplug_dev || hotplug_dev->cool_dev != cdev) + return -EINVAL; + + if (hotplug_dev->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_dev->allowed_cpus) { + if (cpu_online(cpuid) && (cpuid != this_cpu)) + cpu_down(cpuid); + } + } else if (state == 0) { + for_each_cpu(cpuid, hotplug_dev->allowed_cpus) { + if (!cpu_online(cpuid) && (cpuid != this_cpu)) + cpu_up(cpuid); + } + } else { + return -EINVAL; + } + + hotplug_dev->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; + struct hotplug_cooling_device *hotplug_dev; + int ret = 0; + char dev_name[THERMAL_NAME_LENGTH]; + + hotplug_dev = + kzalloc(sizeof(struct hotplug_cooling_device), GFP_KERNEL); + + if (!hotplug_dev) + return ERR_PTR(-ENOMEM); + + ret = get_idr(&cpuhotplug_idr, &cooling_cpuhotplug_lock, + &hotplug_dev->id); + if (ret) { + kfree(hotplug_dev); + return ERR_PTR(-EINVAL); + } + + sprintf(dev_name, "cpu-hotplug-%u", hotplug_dev->id); + + hotplug_dev->hotplug_state = 0; + hotplug_dev->allowed_cpus = mask_val; + cool_dev = thermal_cooling_device_register(dev_name, hotplug_dev, + &cpuhotplug_cooling_ops); + if (!cool_dev) { + release_idr(&cpuhotplug_idr, &cooling_cpuhotplug_lock, + hotplug_dev->id); + kfree(hotplug_dev); + return ERR_PTR(-EINVAL); + } + + hotplug_dev->cool_dev = cool_dev; + mutex_lock(&cooling_cpuhotplug_lock); + list_add_tail(&hotplug_dev->node, &cooling_cpuhotplug_list); + mutex_unlock(&cooling_cpuhotplug_lock); + + return cool_dev; +} +EXPORT_SYMBOL(cpuhotplug_cooling_register); + +void cpuhotplug_cooling_unregister(struct thermal_cooling_device *cdev) +{ + struct hotplug_cooling_device *hotplug_dev = NULL; + + mutex_lock(&cooling_cpuhotplug_lock); + list_for_each_entry(hotplug_dev, &cooling_cpuhotplug_list, node) + if (hotplug_dev && hotplug_dev->cool_dev == cdev) + break; + + if (!hotplug_dev || hotplug_dev->cool_dev != cdev) { + mutex_unlock(&cooling_cpuhotplug_lock); + return; + } + + list_del(&hotplug_dev->node); + mutex_unlock(&cooling_cpuhotplug_lock); + thermal_cooling_device_unregister(hotplug_dev->cool_dev); + release_idr(&cpuhotplug_idr, &cooling_cpuhotplug_lock, + hotplug_dev->id); + kfree(hotplug_dev); +} +EXPORT_SYMBOL(cpuhotplug_cooling_unregister); |