diff options
Diffstat (limited to 'drivers/thermal/cpu_cooling.c')
| -rw-r--r-- | drivers/thermal/cpu_cooling.c | 376 |
1 files changed, 271 insertions, 105 deletions
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c index 836828e29a8..84a75f89bf7 100644 --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -20,10 +20,8 @@ * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ -#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> @@ -31,21 +29,19 @@ #include <linux/cpu_cooling.h> /** - * struct cpufreq_cooling_device + * struct cpufreq_cooling_device - data for cooling device with cpufreq * @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. + * @cool_dev: thermal_cooling_device pointer to keep track of the + * registered cooling device. * @cpufreq_state: integer value representing the current state of cpufreq * cooling devices. * @cpufreq_val: integer value representing the absolute value of the clipped * frequency. * @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 + * cpufreq_cooling_device registered. In order to prevent corruption of this a * mutex lock cooling_cpufreq_lock is used. */ struct cpufreq_cooling_device { @@ -54,9 +50,7 @@ struct cpufreq_cooling_device { unsigned int cpufreq_state; unsigned int cpufreq_val; struct cpumask allowed_cpus; - struct list_head node; }; -static LIST_HEAD(cooling_cpufreq_list); static DEFINE_IDR(cpufreq_idr); static DEFINE_MUTEX(cooling_cpufreq_lock); @@ -70,24 +64,23 @@ static struct cpufreq_cooling_device *notify_device; * get_idr - function to get a unique id. * @idr: struct idr * handle used to create a id. * @id: int * value generated by this function. + * + * This function will populate @id with an unique + * id, using the idr API. + * + * Return: 0 on success, an error code on failure. */ static int get_idr(struct idr *idr, int *id) { - int err; -again: - if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0)) - return -ENOMEM; + int ret; mutex_lock(&cooling_cpufreq_lock); - err = idr_get_new(idr, NULL, id); + ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL); mutex_unlock(&cooling_cpufreq_lock); + if (unlikely(ret < 0)) + return ret; + *id = ret; - if (unlikely(err == -EAGAIN)) - goto again; - else if (unlikely(err)) - return err; - - *id = *id & MAX_IDR_MASK; return 0; } @@ -106,63 +99,162 @@ static void release_idr(struct idr *idr, int id) /* Below code defines functions to be used for cpufreq as cooling device */ /** - * is_cpufreq_valid - function to check if a cpu has frequency transition policy. + * is_cpufreq_valid - function to check frequency transitioning capability. * @cpu: cpu for which check is needed. + * + * This function will check the current state of the system if + * it is capable of changing the frequency for a given @cpu. + * + * Return: 0 if the system is not currently capable of changing + * the frequency of given cpu. !0 in case the frequency is changeable. */ static int is_cpufreq_valid(int cpu) { struct cpufreq_policy policy; + return !cpufreq_get_policy(&policy, cpu); } +enum cpufreq_cooling_property { + GET_LEVEL, + GET_FREQ, + GET_MAXL, +}; + /** - * get_cpu_frequency - get the absolute value of frequency from level. - * @cpu: cpu for which frequency is fetched. - * @level: level of frequency of the CPU - * e.g level=1 --> 1st MAX FREQ, LEVEL=2 ---> 2nd MAX FREQ, .... etc + * get_property - fetch a property of interest for a give cpu. + * @cpu: cpu for which the property is required + * @input: query parameter + * @output: query return + * @property: type of query (frequency, level, max level) + * + * This is the common function to + * 1. get maximum cpu cooling states + * 2. translate frequency to cooling state + * 3. translate cooling state to frequency + * Note that the code may be not in good shape + * but it is written in this way in order to: + * a) reduce duplicate code as most of the code can be shared. + * b) make sure the logic is consistent when translating between + * cooling states and frequencies. + * + * Return: 0 on success, -EINVAL when invalid parameters are passed. */ -static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) +static int get_property(unsigned int cpu, unsigned long input, + unsigned int *output, + enum cpufreq_cooling_property property) { - int ret = 0, i = 0; - unsigned long level_index; - bool descend = false; - struct cpufreq_frequency_table *table = + int i; + unsigned long max_level = 0, level = 0; + unsigned int freq = CPUFREQ_ENTRY_INVALID; + int descend = -1; + struct cpufreq_frequency_table *pos, *table = cpufreq_frequency_get_table(cpu); + + if (!output) + return -EINVAL; + if (!table) - return ret; + return -EINVAL; - while (table[i].frequency != CPUFREQ_TABLE_END) { - if (table[i].frequency == CPUFREQ_ENTRY_INVALID) + cpufreq_for_each_valid_entry(pos, table) { + /* ignore duplicate entry */ + if (freq == pos->frequency) continue; - /*check if table in ascending or descending order*/ - if ((table[i + 1].frequency != CPUFREQ_TABLE_END) && - (table[i + 1].frequency < table[i].frequency) - && !descend) { - descend = true; - } + /* get the frequency order */ + if (freq != CPUFREQ_ENTRY_INVALID && descend == -1) + descend = freq > pos->frequency; - /*return if level matched and table in descending order*/ - if (descend && i == level) - return table[i].frequency; - i++; + freq = pos->frequency; + max_level++; } - i--; - if (level > i || descend) - return ret; - level_index = i - level; + /* No valid cpu frequency entry */ + if (max_level == 0) + return -EINVAL; + + /* max_level is an index, not a counter */ + max_level--; + + /* get max level */ + if (property == GET_MAXL) { + *output = (unsigned int)max_level; + return 0; + } + + if (property == GET_FREQ) + level = descend ? input : (max_level - input); - /*Scan the table in reverse order and match the level*/ - while (i >= 0) { - if (table[i].frequency == CPUFREQ_ENTRY_INVALID) + i = 0; + cpufreq_for_each_valid_entry(pos, table) { + /* ignore duplicate entry */ + if (freq == pos->frequency) continue; - /*return if level matched*/ - if (i == level_index) - return table[i].frequency; - i--; + + /* now we have a valid frequency entry */ + freq = pos->frequency; + + if (property == GET_LEVEL && (unsigned int)input == freq) { + /* get level by frequency */ + *output = descend ? i : (max_level - i); + return 0; + } + if (property == GET_FREQ && level == i) { + /* get frequency by level */ + *output = freq; + return 0; + } + i++; } - return ret; + + return -EINVAL; +} + +/** + * cpufreq_cooling_get_level - for a give cpu, return the cooling level. + * @cpu: cpu for which the level is required + * @freq: the frequency of interest + * + * This function will match the cooling level corresponding to the + * requested @freq and return it. + * + * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID + * otherwise. + */ +unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq) +{ + unsigned int val; + + if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL)) + return THERMAL_CSTATE_INVALID; + + return (unsigned long)val; +} +EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level); + +/** + * get_cpu_frequency - get the absolute value of frequency from level. + * @cpu: cpu for which frequency is fetched. + * @level: cooling level + * + * This function matches cooling level with frequency. Based on a cooling level + * of frequency, equals cooling state of cpu cooling device, it will return + * the corresponding frequency. + * e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc + * + * Return: 0 on error, the corresponding frequency otherwise. + */ +static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) +{ + int ret = 0; + unsigned int freq; + + ret = get_property(cpu, level, &freq, GET_FREQ); + if (ret) + return 0; + + return freq; } /** @@ -170,13 +262,19 @@ static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) * @cpufreq_device: cpufreq_cooling_device pointer containing frequency * clipping data. * @cooling_state: value of the cooling state. + * + * Function used to make sure the cpufreq layer is aware of current thermal + * limits. The limits are applied by updating the cpufreq policy. + * + * Return: 0 on success, an error code otherwise (-EINVAL in case wrong + * cooling state). */ static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, - unsigned long cooling_state) + unsigned long cooling_state) { unsigned int cpuid, clip_freq; - struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; - unsigned int cpu = cpumask_any(maskPtr); + struct cpumask *mask = &cpufreq_device->allowed_cpus; + unsigned int cpu = cpumask_any(mask); /* Check if the old cooling action is same as new cooling action */ @@ -191,7 +289,7 @@ static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, cpufreq_device->cpufreq_val = clip_freq; notify_device = cpufreq_device; - for_each_cpu(cpuid, maskPtr) { + for_each_cpu(cpuid, mask) { if (is_cpufreq_valid(cpuid)) cpufreq_update_policy(cpuid); } @@ -206,9 +304,15 @@ static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, * @nb: struct notifier_block * with callback info. * @event: value showing cpufreq event for which this function invoked. * @data: callback-specific data + * + * Callback to highjack the notification on cpufreq policy transition. + * Every time there is a change in policy, we will intercept and + * update the cpufreq policy with thermal constraints. + * + * Return: 0 (success) */ static int cpufreq_thermal_notifier(struct notifier_block *nb, - unsigned long event, void *data) + unsigned long event, void *data) { struct cpufreq_policy *policy = data; unsigned long max_freq = 0; @@ -218,8 +322,10 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb, if (cpumask_test_cpu(policy->cpu, ¬ify_device->allowed_cpus)) max_freq = notify_device->cpufreq_val; + else + return 0; - /* Never exceed user_policy.max*/ + /* Never exceed user_policy.max */ if (max_freq > policy->user_policy.max) max_freq = policy->user_policy.max; @@ -229,50 +335,46 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb, return 0; } -/* - * cpufreq cooling device callback functions are defined below - */ +/* 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. + * + * Callback for the thermal cooling device to return the cpufreq + * max cooling state. + * + * Return: 0 on success, an error code otherwise. */ static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state) { struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; - struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; + struct cpumask *mask = &cpufreq_device->allowed_cpus; unsigned int cpu; - struct cpufreq_frequency_table *table; - unsigned long count = 0; - int i = 0; - - cpu = cpumask_any(maskPtr); - table = cpufreq_frequency_get_table(cpu); - if (!table) { - *state = 0; - return 0; - } + unsigned int count = 0; + int ret; - for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { - if (table[i].frequency == CPUFREQ_ENTRY_INVALID) - continue; - count++; - } + cpu = cpumask_any(mask); - if (count > 0) { - *state = --count; - return 0; - } + ret = get_property(cpu, 0, &count, GET_MAXL); - return -EINVAL; + if (count > 0) + *state = count; + + 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. + * + * Callback for the thermal cooling device to return the cpufreq + * current cooling state. + * + * Return: 0 on success, an error code otherwise. */ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state) @@ -280,6 +382,7 @@ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; *state = cpufreq_device->cpufreq_state; + return 0; } @@ -287,6 +390,11 @@ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, * 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. + * + * Callback for the thermal cooling device to change the cpufreq + * current cooling state. + * + * Return: 0 on success, an error code otherwise. */ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) @@ -309,11 +417,21 @@ static struct notifier_block thermal_cpufreq_notifier_block = { }; /** - * cpufreq_cooling_register - function to create cpufreq cooling device. + * __cpufreq_cooling_register - helper function to create cpufreq cooling device + * @np: a valid struct device_node to the cooling device device tree node * @clip_cpus: cpumask of cpus where the frequency constraints will happen. + * + * This interface function registers the cpufreq cooling device with the name + * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq + * cooling devices. It also gives the opportunity to link the cooling device + * with a device tree node, in order to bind it via the thermal DT code. + * + * Return: a valid struct thermal_cooling_device pointer on success, + * on failure, it returns a corresponding ERR_PTR(). */ -struct thermal_cooling_device *cpufreq_cooling_register( - const struct cpumask *clip_cpus) +static struct thermal_cooling_device * +__cpufreq_cooling_register(struct device_node *np, + const struct cpumask *clip_cpus) { struct thermal_cooling_device *cool_dev; struct cpufreq_cooling_device *cpufreq_dev = NULL; @@ -322,9 +440,9 @@ struct thermal_cooling_device *cpufreq_cooling_register( int ret = 0, i; struct cpufreq_policy policy; - /*Verify that all the clip cpus have same freq_min, freq_max limit*/ + /* Verify that all the clip cpus have same freq_min, freq_max limit */ for_each_cpu(i, clip_cpus) { - /*continue if cpufreq policy not found and not return error*/ + /* continue if cpufreq policy not found and not return error */ if (!cpufreq_get_policy(&policy, i)) continue; if (min == 0 && max == 0) { @@ -332,12 +450,12 @@ struct thermal_cooling_device *cpufreq_cooling_register( max = policy.cpuinfo.max_freq; } else { if (min != policy.cpuinfo.min_freq || - max != policy.cpuinfo.max_freq) + max != policy.cpuinfo.max_freq) return ERR_PTR(-EINVAL); } } cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device), - GFP_KERNEL); + GFP_KERNEL); if (!cpufreq_dev) return ERR_PTR(-ENOMEM); @@ -349,14 +467,15 @@ struct thermal_cooling_device *cpufreq_cooling_register( return ERR_PTR(-EINVAL); } - sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id); + snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d", + cpufreq_dev->id); - cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev, - &cpufreq_cooling_ops); - if (!cool_dev) { + cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev, + &cpufreq_cooling_ops); + if (IS_ERR(cool_dev)) { release_idr(&cpufreq_idr, cpufreq_dev->id); kfree(cpufreq_dev); - return ERR_PTR(-EINVAL); + return cool_dev; } cpufreq_dev->cool_dev = cool_dev; cpufreq_dev->cpufreq_state = 0; @@ -365,34 +484,81 @@ struct thermal_cooling_device *cpufreq_cooling_register( /* Register the notifier for first cpufreq cooling device */ if (cpufreq_dev_count == 0) cpufreq_register_notifier(&thermal_cpufreq_notifier_block, - CPUFREQ_POLICY_NOTIFIER); + CPUFREQ_POLICY_NOTIFIER); cpufreq_dev_count++; mutex_unlock(&cooling_cpufreq_lock); + return cool_dev; } -EXPORT_SYMBOL(cpufreq_cooling_register); + +/** + * cpufreq_cooling_register - function to create cpufreq cooling device. + * @clip_cpus: cpumask of cpus where the frequency constraints will happen. + * + * This interface function registers the cpufreq cooling device with the name + * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq + * cooling devices. + * + * Return: a valid struct thermal_cooling_device pointer on success, + * on failure, it returns a corresponding ERR_PTR(). + */ +struct thermal_cooling_device * +cpufreq_cooling_register(const struct cpumask *clip_cpus) +{ + return __cpufreq_cooling_register(NULL, clip_cpus); +} +EXPORT_SYMBOL_GPL(cpufreq_cooling_register); + +/** + * of_cpufreq_cooling_register - function to create cpufreq cooling device. + * @np: a valid struct device_node to the cooling device device tree node + * @clip_cpus: cpumask of cpus where the frequency constraints will happen. + * + * This interface function registers the cpufreq cooling device with the name + * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq + * cooling devices. Using this API, the cpufreq cooling device will be + * linked to the device tree node provided. + * + * Return: a valid struct thermal_cooling_device pointer on success, + * on failure, it returns a corresponding ERR_PTR(). + */ +struct thermal_cooling_device * +of_cpufreq_cooling_register(struct device_node *np, + const struct cpumask *clip_cpus) +{ + if (!np) + return ERR_PTR(-EINVAL); + + return __cpufreq_cooling_register(np, clip_cpus); +} +EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register); /** * cpufreq_cooling_unregister - function to remove cpufreq cooling device. * @cdev: thermal cooling device pointer. + * + * This interface function unregisters the "thermal-cpufreq-%x" cooling device. */ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) { - struct cpufreq_cooling_device *cpufreq_dev = cdev->devdata; + struct cpufreq_cooling_device *cpufreq_dev; + if (!cdev) + return; + + cpufreq_dev = cdev->devdata; mutex_lock(&cooling_cpufreq_lock); cpufreq_dev_count--; /* Unregister the notifier for the last cpufreq cooling device */ - if (cpufreq_dev_count == 0) { + if (cpufreq_dev_count == 0) cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, - CPUFREQ_POLICY_NOTIFIER); - } + 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); +EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister); |