Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758360Ab2FZHmt (ORCPT ); Tue, 26 Jun 2012 03:42:49 -0400 Received: from na3sys009aog137.obsmtp.com ([74.125.149.18]:53445 "EHLO na3sys009aog137.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754808Ab2FZHmo convert rfc822-to-8bit (ORCPT ); Tue, 26 Jun 2012 03:42:44 -0400 MIME-Version: 1.0 In-Reply-To: References: <1336815645-29625-1-git-send-email-amit.kachhap@linaro.org> <1336815645-29625-2-git-send-email-amit.kachhap@linaro.org> Date: Tue, 26 Jun 2012 10:42:43 +0300 Message-ID: Subject: Re: [PATCH v4 1/5] thermal: Add generic cpufreq cooling implementation From: "Valentin, Eduardo" To: Rob Lee Cc: Amit Daniel Kachhap , linux-pm@lists.linux-foundation.org, akpm@linux-foundation.org, linux-samsung-soc@vger.kernel.org, durgadoss.r@intel.com, patches@linaro.org, linux-kernel@vger.kernel.org, lm-sensors@lm-sensors.org, linux-acpi@vger.kernel.org, khali@linux-fr.org, linaro-dev@lists.linaro.org, rui.zhang@intel.com, guenter.roeck@ericsson.com, lenb@kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 31856 Lines: 818 Hey Rob and Amit, On Tue, Jun 26, 2012 at 6:12 AM, Rob Lee wrote: > Hey Amit, > > I was just re-organizing the imx thermal driver that uses this cpu > cooling interface and noticed a couple of small issues here. ? If While rewriting the OMAP BG driver on top of this series I noticed similar issues. Apart from those pointed by Rob, I have another minor fix. > these suggestions are agreed upon and if it's too late for these > issues be changed with this patchset, I can submit them separately > unless you'd prefer to. > > On Sat, May 12, 2012 at 4:40 AM, Amit Daniel Kachhap > wrote: >> This patch adds support for generic cpu thermal cooling low level >> implementations using frequency scaling up/down based on the registration >> parameters. 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 APIs return the >> cooling device pointer. The user of these APIs are responsible for >> passing clipping frequency . The drivers can also register to recieve >> notification about any cooling action called. >> >> Signed-off-by: Amit Daniel Kachhap >> --- >> ?Documentation/thermal/cpu-cooling-api.txt | ? 60 ++++ >> ?drivers/thermal/Kconfig ? ? ? ? ? ? ? ? ? | ? 11 + >> ?drivers/thermal/Makefile ? ? ? ? ? ? ? ? ?| ? ?3 +- >> ?drivers/thermal/cpu_cooling.c ? ? ? ? ? ? | ?483 +++++++++++++++++++++++++++++ >> ?include/linux/cpu_cooling.h ? ? ? ? ? ? ? | ? 99 ++++++ >> ?5 files changed, 655 insertions(+), 1 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..557adb8 >> --- /dev/null >> +++ b/Documentation/thermal/cpu-cooling-api.txt >> @@ -0,0 +1,60 @@ >> +CPU cooling APIs How To >> +=================================== >> + >> +Written by Amit Daniel Kachhap >> + >> +Updated: 12 May 2012 >> + >> +Copyright (c) ?2012 Samsung Electronics Co., Ltd(http://www.samsung.com) >> + >> +0. Introduction >> + >> +The generic cpu cooling(freq clipping, cpuhotplug etc) provides >> +registration/unregistration APIs to the caller. The binding of the cooling >> +devices to the trip point is left for the user. The registration APIs returns >> +the cooling device pointer. >> + >> +1. cpu cooling APIs >> + >> +1.1 cpufreq registration/unregistration APIs >> +1.1.1 struct thermal_cooling_device *cpufreq_cooling_register( >> + ? ? ? struct freq_clip_table *tab_ptr, unsigned int tab_size) >> + >> + ? ?This interface function registers the cpufreq cooling device with the name >> + ? ?"thermal-cpufreq-%x". This api can support multiple instances of cpufreq >> + ? ?cooling devices. >> + >> + ? ?tab_ptr: The table containing the maximum value of frequency to be clipped >> + ? ?for each cooling state. >> + ? ? ? .freq_clip_max: Value of frequency to be clipped for each allowed >> + ? ? ? ?cpus. >> + ? ? ? .temp_level: Temperature level at which the frequency clamping will >> + ? ? ? happen. >> + ? ? ? .mask_val: cpumask of the allowed cpu's >> + ? ?tab_size: the total number of cpufreq cooling states. >> + >> +1.1.2 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) >> + >> + ? ?This interface function unregisters the "thermal-cpufreq-%x" cooling device. >> + >> + ? ?cdev: Cooling device pointer which has to be unregistered. >> + >> + >> +1.2 CPU cooling action notifier register/unregister interface >> +1.2.1 int cputherm_register_notifier(struct notifier_block *nb, >> + ? ? ? unsigned int list) >> + >> + ? ?This interface registers a driver with cpu cooling layer. The driver will >> + ? ?be notified when any cpu cooling action is called. >> + >> + ? ?nb: notifier function to register >> + ? ?list: CPUFREQ_COOLING_START or CPUFREQ_COOLING_STOP >> + >> +1.2.2 int cputherm_unregister_notifier(struct notifier_block *nb, >> + ? ? ? unsigned int list) >> + >> + ? ?This interface registers a driver with cpu cooling layer. The driver will >> + ? ?be notified when any cpu cooling action is called. >> + >> + ? ?nb: notifier function to register >> + ? ?list: CPUFREQ_COOLING_START or CPUFREQ_COOLING_STOP >> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig >> index 514a691..d9c529f 100644 >> --- a/drivers/thermal/Kconfig >> +++ b/drivers/thermal/Kconfig >> @@ -19,6 +19,17 @@ config THERMAL_HWMON >> ? ? ? ?depends on HWMON=y || HWMON=THERMAL >> ? ? ? ?default y >> >> +config CPU_THERMAL > > Perhaps the name CPU_COOLING or CPUFREQ_COOLING would more accurately > describe this functionality? ?I like the latter since now this > mechanism only supports cooling by using cpufreq. > >> + ? ? ? bool "generic cpu cooling support" > > If we use CPUFREQ_COOLING, then perhaps this could say: > > bool "cpu cooling through cpufreq frequency limiting" > >> + ? ? ? depends on THERMAL && CPU_FREQ >> + ? ? ? 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. >> + > > Currently, only the "frequency reduction" method exists so perhaps > it's best to remove mention of "cpu hotplug and any other ways of > reducing temperature"? ?Here'as a version for cpufreq only: > > config CPUFREQ_COOLING > ? ? ? ?bool "cpu cooling through cpufreq frequency limiting" > ? ? ? ?depends on THERMAL && CPU_FREQ > ? ? ? ?help > ? ? ? ? ?This implements a generic cpu cooling mechanism through cpufreq > ? ? ? ? ?frequency limiting. 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. > >> ?config SPEAR_THERMAL >> ? ? ? ?bool "SPEAr thermal sensor driver" >> ? ? ? ?depends on THERMAL >> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile >> index a9fff0b..30c456c 100644 >> --- a/drivers/thermal/Makefile >> +++ b/drivers/thermal/Makefile >> @@ -3,4 +3,5 @@ >> ?# >> >> ?obj-$(CONFIG_THERMAL) ? ? ? ? ?+= thermal_sys.o >> -obj-$(CONFIG_SPEAR_THERMAL) ? ? ? ? ? ?+= spear_thermal.o >> \ No newline at end of file >> +obj-$(CONFIG_CPU_THERMAL) ? ? ? += cpu_cooling.o >> +obj-$(CONFIG_SPEAR_THERMAL) ? ? ? ? ? ?+= spear_thermal.o >> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c >> new file mode 100644 >> index 0000000..c40d9a0 >> --- /dev/null >> +++ b/drivers/thermal/cpu_cooling.c >> @@ -0,0 +1,483 @@ >> +/* >> + * ?linux/drivers/thermal/cpu_cooling.c >> + * >> + * ?Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) >> + * ?Copyright (C) 2012 ?Amit Daniel >> + * >> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> + * ?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 >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +/** >> + * struct cpufreq_cooling_device >> + * @id: unique integer value corresponding to each cpufreq_cooling_device >> + * ? ? registered. >> + * @cool_dev: thermal_cooling_device pointer to keep track of the the >> + * ? ? egistered cooling device. >> + * @tab_ptr: freq_clip_table table containing the maximum value of frequency to >> + * ? ? be set for different cooling state. >> + * @tab_size: integer value representing a count of the above table. >> + * @cpufreq_state: integer value representing the current state of cpufreq >> + * ? ? cooling devices. >> + * @allowed_cpus: all the cpus involved for this cpufreq_cooling_device. >> + * @node: list_head to link all cpufreq_cooling_device together. >> + * >> + * This structure is required for keeping information of each >> + * cpufreq_cooling_device registered as a list whose head is represented by >> + * cooling_cpufreq_list. In order to prevent corruption of this list a >> + * mutex lock cooling_cpufreq_lock is used. >> + */ >> +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_state; >> + ? ? ? struct cpumask allowed_cpus; >> + ? ? ? struct list_head node; >> +}; >> +static LIST_HEAD(cooling_cpufreq_list); >> +static DEFINE_MUTEX(cooling_cpufreq_lock); >> +static DEFINE_IDR(cpufreq_idr); >> + >> +/*per cpu variable to store the previous max frequency allowed*/ >> +static DEFINE_PER_CPU(unsigned int, max_policy_freq); >> + >> +/*notify_table passes value to the CPUFREQ_ADJUST callback function.*/ >> +#define NOTIFY_INVALID NULL >> +static struct freq_clip_table *notify_table; >> + >> +/*Head of the blocking notifier chain to inform about frequency clamping*/ >> +static BLOCKING_NOTIFIER_HEAD(cputherm_state_notifier_list); >> + >> +/** >> + * get_idr - function to get a unique id. >> + * @idr: struct idr * handle used to create a id. >> + * @id: int * value generated by this function. >> + */ >> +static int get_idr(struct idr *idr, int *id) >> +{ >> + ? ? ? int err; >> +again: >> + ? ? ? if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0)) >> + ? ? ? ? ? ? ? return -ENOMEM; >> + >> + ? ? ? mutex_lock(&cooling_cpufreq_lock); >> + ? ? ? err = idr_get_new(idr, NULL, id); >> + ? ? ? mutex_unlock(&cooling_cpufreq_lock); >> + >> + ? ? ? if (unlikely(err == -EAGAIN)) >> + ? ? ? ? ? ? ? goto again; >> + ? ? ? else if (unlikely(err)) >> + ? ? ? ? ? ? ? return err; >> + >> + ? ? ? *id = *id & MAX_ID_MASK; >> + ? ? ? return 0; >> +} >> + >> +/** >> + * release_idr - function to free the unique id. >> + * @idr: struct idr * handle used for creating the id. >> + * @id: int value representing the unique id. >> + */ >> +static void release_idr(struct idr *idr, int id) >> +{ >> + ? ? ? mutex_lock(&cooling_cpufreq_lock); >> + ? ? ? idr_remove(idr, id); >> + ? ? ? mutex_unlock(&cooling_cpufreq_lock); >> +} >> + >> +/** >> + * cputherm_register_notifier - Register a notifier with cpu cooling interface. >> + * @nb: ? ? ? ?struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. possible values are >> + * ? ? CPUFREQ_COOLING_START and CPUFREQ_COOLING_STOP. >> + * >> + * This exported function registers a driver with cpu cooling layer. The driver >> + * will be notified when any cpu cooling action is called. >> + */ >> +int cputherm_register_notifier(struct notifier_block *nb, unsigned int list) >> +{ >> + ? ? ? int ret = 0; >> + >> + ? ? ? switch (list) { >> + ? ? ? case CPUFREQ_COOLING_START: >> + ? ? ? case CPUFREQ_COOLING_STOP: >> + ? ? ? ? ? ? ? ret = blocking_notifier_chain_register( >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? &cputherm_state_notifier_list, nb); >> + ? ? ? ? ? ? ? break; >> + ? ? ? default: >> + ? ? ? ? ? ? ? ret = -EINVAL; >> + ? ? ? } >> + ? ? ? return ret; >> +} >> +EXPORT_SYMBOL(cputherm_register_notifier); >> + >> +/** >> + * cputherm_unregister_notifier - Un-register a notifier. >> + * @nb: ? ? ? ?struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. values possible are >> + * ? ? CPUFREQ_COOLING_START or CPUFREQ_COOLING_STOP. >> + * >> + * This exported function un-registers a driver with cpu cooling layer. >> + */ >> +int cputherm_unregister_notifier(struct notifier_block *nb, unsigned int list) >> +{ >> + ? ? ? int ret = 0; >> + >> + ? ? ? switch (list) { >> + ? ? ? case CPUFREQ_COOLING_START: >> + ? ? ? case CPUFREQ_COOLING_STOP: >> + ? ? ? ? ? ? ? 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*/ >> + >> +/** >> + * is_cpufreq_valid - function to check if a cpu has frequency transition policy. >> + * @cpu: cpu for which check is needed. >> + */ >> +static int is_cpufreq_valid(int cpu) >> +{ >> + ? ? ? struct cpufreq_policy policy; >> + ? ? ? return !cpufreq_get_policy(&policy, cpu); >> +} >> + >> +/** >> + * cpufreq_apply_cooling - function to apply frequency clipping. >> + * @cpufreq_device: cpufreq_cooling_device pointer containing frequency >> + * ? ? clipping data. >> + * @cooling_state: value of the cooling state. >> + */ >> +static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? unsigned long cooling_state) >> +{ >> + ? ? ? unsigned int event, cpuid, state; >> + ? ? ? struct freq_clip_table *th_table, *table_ptr; >> + ? ? ? const struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; >> + ? ? ? struct cpufreq_cooling_device *cpufreq_ptr; >> + >> + ? ? ? if (cooling_state > cpufreq_device->tab_size) >> + ? ? ? ? ? ? ? return -EINVAL; >> + >> + ? ? ? /*Check if the old cooling action is same as new cooling action*/ >> + ? ? ? if (cpufreq_device->cpufreq_state == cooling_state) >> + ? ? ? ? ? ? ? return 0; >> + >> + ? ? ? /*pass cooling table info to the cpufreq_thermal_notifier callback*/ >> + ? ? ? notify_table = NOTIFY_INVALID; >> + >> + ? ? ? if (cooling_state > 0) { >> + ? ? ? ? ? ? ? th_table = &(cpufreq_device->tab_ptr[cooling_state - 1]); >> + ? ? ? ? ? ? ? notify_table = th_table; >> + ? ? ? } >> + >> + ? ? ? /*check if any lower clip frequency active in other cpufreq_device's*/ >> + ? ? ? list_for_each_entry(cpufreq_ptr, &cooling_cpufreq_list, node) { >> + >> + ? ? ? ? ? ? ? state = cpufreq_ptr->cpufreq_state; >> + ? ? ? ? ? ? ? if (state == 0 || cpufreq_ptr == cpufreq_device) >> + ? ? ? ? ? ? ? ? ? ? ? continue; >> + >> + ? ? ? ? ? ? ? if (!cpumask_equal(&cpufreq_ptr->allowed_cpus, >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? &cpufreq_device->allowed_cpus)) >> + ? ? ? ? ? ? ? ? ? ? ? continue; >> + >> + ? ? ? ? ? ? ? table_ptr = &(cpufreq_ptr->tab_ptr[state - 1]); >> + ? ? ? ? ? ? ? if (notify_table == NULL || >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? (table_ptr->freq_clip_max < >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? notify_table->freq_clip_max)) >> + ? ? ? ? ? ? ? ? ? ? ? notify_table = ?table_ptr; >> + ? ? ? } >> + >> + ? ? ? cpufreq_device->cpufreq_state = cooling_state; >> + >> + ? ? ? if (notify_table != NOTIFY_INVALID) { >> + ? ? ? ? ? ? ? event = CPUFREQ_COOLING_START; >> + ? ? ? ? ? ? ? maskPtr = notify_table->mask_val; >> + ? ? ? } else { >> + ? ? ? ? ? ? ? event = CPUFREQ_COOLING_STOP; >> + ? ? ? } >> + >> + ? ? ? blocking_notifier_call_chain(&cputherm_state_notifier_list, >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? event, notify_table); >> + >> + ? ? ? for_each_cpu(cpuid, maskPtr) { >> + ? ? ? ? ? ? ? if (is_cpufreq_valid(cpuid)) >> + ? ? ? ? ? ? ? ? ? ? ? cpufreq_update_policy(cpuid); >> + ? ? ? } >> + >> + ? ? ? notify_table = NOTIFY_INVALID; >> + >> + ? ? ? return 0; >> +} >> + >> +/** >> + * cpufreq_thermal_notifier - notifier callback for cpufreq policy change. >> + * @nb: ? ? ? ?struct notifier_block * with callback info. >> + * @event: value showing cpufreq event for which this function invoked. >> + * @data: callback-specific data >> + */ >> +static int cpufreq_thermal_notifier(struct notifier_block *nb, >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? unsigned long event, void *data) >> +{ >> + ? ? ? struct cpufreq_policy *policy = data; >> + ? ? ? unsigned long max_freq = 0; >> + >> + ? ? ? if (event != CPUFREQ_ADJUST) >> + ? ? ? ? ? ? ? return 0; >> + >> + ? ? ? if (notify_table != NOTIFY_INVALID) { >> + ? ? ? ? ? ? ? max_freq = notify_table->freq_clip_max; >> + >> + ? ? ? ? ? ? ? if (!per_cpu(max_policy_freq, policy->cpu)) >> + ? ? ? ? ? ? ? ? ? ? ? per_cpu(max_policy_freq, policy->cpu) = policy->max; >> + ? ? ? } else { >> + ? ? ? ? ? ? ? if (per_cpu(max_policy_freq, policy->cpu)) { >> + ? ? ? ? ? ? ? ? ? ? ? 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 are defined below >> + */ >> + >> +/** >> + * cpufreq_get_max_state - callback function to get the max cooling state. >> + * @cdev: thermal cooling device pointer. >> + * @state: fill this variable with the max cooling state. >> + */ >> +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 = cpufreq_device->tab_size; >> + ? ? ? ? ? ? ? ? ? ? ? ret = 0; >> + ? ? ? ? ? ? ? ? ? ? ? break; >> + ? ? ? ? ? ? ? } >> + ? ? ? } >> + ? ? ? mutex_unlock(&cooling_cpufreq_lock); >> + ? ? ? return ret; >> +} >> + >> +/** >> + * cpufreq_get_cur_state - callback function to get the current cooling state. >> + * @cdev: thermal cooling device pointer. >> + * @state: fill this variable with the current cooling state. >> + */ >> +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_state; >> + ? ? ? ? ? ? ? ? ? ? ? ret = 0; >> + ? ? ? ? ? ? ? ? ? ? ? break; >> + ? ? ? ? ? ? ? } >> + ? ? ? } >> + ? ? ? mutex_unlock(&cooling_cpufreq_lock); >> + ? ? ? return ret; >> +} >> + >> +/** >> + * cpufreq_set_cur_state - callback function to set the current cooling state. >> + * @cdev: thermal cooling device pointer. >> + * @state: set this variable to the current cooling state. >> + */ >> +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; >> + ? ? ? ? ? ? ? } >> + ? ? ? } >> + ? ? ? if (!ret) >> + ? ? ? ? ? ? ? ret = cpufreq_apply_cooling(cpufreq_device, state); >> + >> + ? ? ? mutex_unlock(&cooling_cpufreq_lock); >> + >> + ? ? ? return ret; >> +} >> + >> +/*Bind cpufreq callbacks to thermal cooling device ops*/ >> +static struct thermal_cooling_device_ops const cpufreq_cooling_ops = { >> + ? ? ? .get_max_state = cpufreq_get_max_state, >> + ? ? ? .get_cur_state = cpufreq_get_cur_state, >> + ? ? ? .set_cur_state = cpufreq_set_cur_state, >> +}; >> + >> +/*Notifier for cpufreq policy change*/ >> +static struct notifier_block thermal_cpufreq_notifier_block = { >> + ? ? ? .notifier_call = cpufreq_thermal_notifier, >> +}; >> + >> +/** >> + * cpufreq_cooling_register - function to create cpufreq cooling device. >> + * @tab_ptr: table ptr containing the maximum value of frequency to be clipped >> + * ? ? for each cooling state. >> + * @tab_size: count of entries in the above table. >> + * ? ? happen. >> + */ >> +struct thermal_cooling_device *cpufreq_cooling_register( >> + ? ? ? struct freq_clip_table *tab_ptr, unsigned int tab_size) >> +{ >> + ? ? ? struct thermal_cooling_device *cool_dev; >> + ? ? ? struct cpufreq_cooling_device *cpufreq_dev = NULL; >> + ? ? ? struct freq_clip_table *clip_tab; >> + ? ? ? 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) >> + ? ? ? ? ? ? ? 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); >> + >> + ? ? ? /*Verify that all the entries of freq_clip_table are present*/ >> + ? ? ? for (i = 0; i < tab_size; i++) { >> + ? ? ? ? ? ? ? clip_tab = ((struct freq_clip_table *)&tab_ptr[i]); >> + ? ? ? ? ? ? ? if (!clip_tab->freq_clip_max || !clip_tab->mask_val >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? || !clip_tab->temp_level) { >> + ? ? ? ? ? ? ? ? ? ? ? kfree(cpufreq_dev); >> + ? ? ? ? ? ? ? ? ? ? ? return ERR_PTR(-EINVAL); >> + ? ? ? ? ? ? ? } >> + ? ? ? ? ? ? ? /* >> + ? ? ? ? ? ? ? ?*Consolidate all the cpumask for all the individual entries >> + ? ? ? ? ? ? ? ?*of the trip table. This is useful in resetting all the >> + ? ? ? ? ? ? ? ?*clipped frequencies to the normal level for each cpufreq >> + ? ? ? ? ? ? ? ?*cooling device. >> + ? ? ? ? ? ? ? ?*/ >> + ? ? ? ? ? ? ? cpumask_or(&cpufreq_dev->allowed_cpus, >> + ? ? ? ? ? ? ? ? ? ? ? &cpufreq_dev->allowed_cpus, clip_tab->mask_val); >> + ? ? ? } >> + >> + ? ? ? cpufreq_dev->tab_ptr = tab_ptr; >> + ? ? ? cpufreq_dev->tab_size = tab_size; >> + >> + ? ? ? ret = get_idr(&cpufreq_idr, &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, 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); >> + >> + ? ? ? /*Register the notifier for first cpufreq cooling device*/ >> + ? ? ? if (cpufreq_dev_count == 0) >> + ? ? ? ? ? ? ? cpufreq_register_notifier(&thermal_cpufreq_notifier_block, >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? CPUFREQ_POLICY_NOTIFIER); >> + >> + ? ? ? mutex_unlock(&cooling_cpufreq_lock); >> + ? ? ? return cool_dev; >> +} >> +EXPORT_SYMBOL(cpufreq_cooling_register); >> + >> +/** >> + * cpufreq_cooling_unregister - function to remove cpufreq cooling device. >> + * @cdev: thermal cooling device pointer. >> + */ >> +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); >> + >> + ? ? ? /*Unregister the notifier for the last cpufreq cooling device*/ >> + ? ? ? if (cpufreq_dev_count == 1) { >> + ? ? ? ? ? ? ? cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? CPUFREQ_POLICY_NOTIFIER); >> + ? ? ? } >> + ? ? ? mutex_unlock(&cooling_cpufreq_lock); >> + ? ? ? thermal_cooling_device_unregister(cpufreq_dev->cool_dev); >> + ? ? ? release_idr(&cpufreq_idr, cpufreq_dev->id); >> + ? ? ? kfree(cpufreq_dev); >> +} >> +EXPORT_SYMBOL(cpufreq_cooling_unregister); >> diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h >> new file mode 100644 >> index 0000000..ed6c096 >> --- /dev/null >> +++ b/include/linux/cpu_cooling.h >> @@ -0,0 +1,99 @@ >> +/* >> + * ?linux/include/linux/cpu_cooling.h >> + * >> + * ?Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) >> + * ?Copyright (C) 2012 ?Amit Daniel >> + * >> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> + * ?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 >> + >> +#define CPUFREQ_COOLING_START ? ? ? ? ?0 >> +#define CPUFREQ_COOLING_STOP ? ? ? ? ? 1 >> + >> +/** >> + * struct freq_clip_table >> + * @freq_clip_max: maximum frequency allowed for this cooling state. >> + * @temp_level: Temperature level at which the temperature clipping will >> + * ? ? happen. >> + * @mask_val: cpumask of the allowed cpu's where the clipping will take place. >> + * >> + * This structure is required to be filled and passed to the >> + * cpufreq_cooling_unregister function. >> + */ >> +struct freq_clip_table { >> + ? ? ? unsigned int freq_clip_max; >> + ? ? ? unsigned int temp_level; >> + ? ? ? const struct cpumask *mask_val; >> +}; >> + >> +/** >> + * cputherm_register_notifier - Register a notifier with cpu cooling interface. >> + * @nb: ? ? ? ?struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. possible values are >> + * ? ? CPUFREQ_COOLING_TYPE and CPUHOTPLUG_COOLING_TYPE. > > CPUFREQ_COOLING_TYPE and CPUHOTPLUG_COOLING_TYPE should be changed to > CPUFREQ_COOLING_START CPUFREQ_COOLING_STOP, right? > >> + * >> + * This exported function registers a driver with cpu cooling layer. The driver >> + * will be notified when any cpu cooling action is called. >> + */ >> +int cputherm_register_notifier(struct notifier_block *nb, unsigned int list); >> + >> +/** >> + * cputherm_unregister_notifier - Un-register a notifier. >> + * @nb: ? ? ? ?struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. values possible are >> + * ? ? CPUFREQ_COOLING_TYPE. > > Should be changed to CPUFREQ_COOLING_START, CPUFREQ_COOLING_STOP, right? > >> + * >> + * This exported function un-registers a driver with cpu cooling layer. >> + */ >> +int cputherm_unregister_notifier(struct notifier_block *nb, unsigned int list); >> + >> +#ifdef CONFIG_CPU_FREQ > > Consider changing this to "#ifdef CPU_THERMAL" ?A platform thermal > driver may want to always call this function as its cpu cooling > mechanism but it should still function without the cpu_cooling being > enabled. ?In this case, the platform thermal driver would only provide > temperature readings and critical trip point handling. ?But if the > platform happened may have CONFIG_CPU_FREQ enabled, a build error > would occur in the current implementation. I agree here. It makes more sense to have the check against CPU_THERMAL > > (the CONFIG_CPU_FREQ requirement will be met by CPU_THERMAL being > enabled since it also implies CONFIG_CPU_FREQ being enabled per the > Kconfig dependency) True. > >> +/** >> + * cpufreq_cooling_register - function to create cpufreq cooling device. >> + * @tab_ptr: table ptr containing the maximum value of frequency to be clipped >> + * ? ? for each cooling state. >> + * @tab_size: count of entries in the above table. >> + * @mask_val: cpumask containing the allowed cpu's where frequency clipping can >> + * ? ? happen. >> + */ >> +struct thermal_cooling_device *cpufreq_cooling_register( >> + ? ? ? struct freq_clip_table *tab_ptr, unsigned int tab_size); >> + >> +/** >> + * cpufreq_cooling_unregister - function to remove cpufreq cooling device. >> + * @cdev: thermal cooling device pointer. >> + */ >> +void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev); >> +#else /*!CONFIG_CPU_FREQ*/ > > Modify comment if above suggestion is taken. > >> +static inline struct thermal_cooling_device *cpufreq_cooling_register( >> + ? ? ? struct freq_clip_table *tab_ptr, unsigned int tab_size); The above semicollon will cause a build error in case this path of the ifdef is taken. >> +{ >> + ? ? ? return NULL; >> +} >> +static inline void cpufreq_cooling_unregister( >> + ? ? ? ? ? ? ? struct thermal_cooling_device *cdev) >> +{ >> + ? ? ? return; >> +} >> +#endif /*CONFIG_CPU_FREQ*/ > > Modify comment if above suggestion is taken. > >> + >> +#endif /* __CPU_COOLING_H__ */ >> -- >> 1.7.1 >> >> >> _______________________________________________ >> linaro-dev mailing list >> linaro-dev@lists.linaro.org >> http://lists.linaro.org/mailman/listinfo/linaro-dev > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at ?http://vger.kernel.org/majordomo-info.html -- Eduardo Valentin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/