This patch adds notification support for those clients of cpu_cooling APIs which may want to do something interesting after receiving these cpu_cooling events. The notifier structure passed is of both Set/Get type. The notfications events can be of type, 1. CPU_COOLING_SET_STATE_PRE 2. CPU_COOLING_SET_STATE_POST 3. CPU_COOLING_GET_CUR_STATE 4. CPU_COOLING_GET_MAX_STATE
The advantages of these notfications is to differentiate between different P states in the cpufreq table and the cooling states. The clients of these events may group few P states into 1 cooling states. Also some more cooling states can be enabled when the maximum of P state is reached. Post notifications can be used for those cases. Signed-off-by: Amit Daniel Kachhap <[email protected]> --- drivers/thermal/cpu_cooling.c | 99 +++++++++++++++++++++++++++++++++++++++- include/linux/cpu_cooling.h | 55 +++++++++++++++++++++++ 2 files changed, 151 insertions(+), 3 deletions(-) diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c index 21f44d4..e2aeb36 100644 --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -50,6 +50,7 @@ struct cpufreq_cooling_device { unsigned int cpufreq_state; unsigned int cpufreq_val; struct cpumask allowed_cpus; + struct cpufreq_cooling_status request_status; struct list_head node; }; static DEFINE_IDR(cpufreq_idr); @@ -59,6 +60,8 @@ static DEFINE_MUTEX(cooling_cpufreq_lock); #define NOTIFY_INVALID NULL static struct cpufreq_cooling_device *notify_device; +/* Notfier list to validates/updates the cpufreq cooling states */ +static BLOCKING_NOTIFIER_HEAD(cpufreq_cooling_state_notifier_list); /* A list to hold all the cpufreq cooling devices registered */ static LIST_HEAD(cpufreq_cooling_list); @@ -266,6 +269,21 @@ static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) return freq; } +static int +cpufreq_cooling_notify_states(struct cpufreq_cooling_status *request, + enum cpu_cooling_state_ops op) +{ + /* Invoke the notifiers which have registered for this state change */ + if (op == CPU_COOLING_SET_STATE_PRE || + op == CPU_COOLING_SET_STATE_POST || + op == CPU_COOLING_GET_MAX_STATE || + op == CPU_COOLING_GET_CUR_STATE) { + blocking_notifier_call_chain( + &cpufreq_cooling_state_notifier_list, op, request); + } + return 0; +} + /** * cpufreq_apply_cooling - function to apply frequency clipping. * @cpufreq_device: cpufreq_cooling_device pointer containing frequency @@ -285,9 +303,18 @@ static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, struct cpumask *mask = &cpufreq_device->allowed_cpus; unsigned int cpu = cpumask_any(mask); + cpufreq_device->request_status.cur_state = + cpufreq_device->cpufreq_state; + cpufreq_device->request_status.new_state = cooling_state; + + cpufreq_cooling_notify_states(&cpufreq_device->request_status, + CPU_COOLING_SET_STATE_PRE); + + cooling_state = cpufreq_device->request_status.new_state; /* Check if the old cooling action is same as new cooling action */ - if (cpufreq_device->cpufreq_state == cooling_state) + if (cpufreq_device->cpufreq_state == + cpufreq_device->request_status.new_state) return 0; clip_freq = get_cpu_frequency(cpu, cooling_state); @@ -304,7 +331,8 @@ static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, } notify_device = NOTIFY_INVALID; - + cpufreq_cooling_notify_states(&cpufreq_device->request_status, + CPU_COOLING_SET_STATE_POST); return 0; } @@ -383,6 +411,11 @@ static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, if (count > 0) *state = count; + cpufreq_device->request_status.max_state = count; + cpufreq_cooling_notify_states(&cpufreq_device->request_status, + CPU_COOLING_GET_MAX_STATE); + *state = cpufreq_device->request_status.max_state; + return ret; } @@ -410,8 +443,12 @@ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, /* Cooling device pointer not found */ return -EINVAL; } + cpufreq_device->request_status.cur_state = + cpufreq_device->cpufreq_state; + cpufreq_cooling_notify_states(&cpufreq_device->request_status, + CPU_COOLING_GET_CUR_STATE); - *state = cpufreq_device->cpufreq_state; + *state = cpufreq_device->request_status.cur_state; return 0; } @@ -520,6 +557,7 @@ __cpufreq_cooling_register(struct device_node *np, } cpufreq_dev->cool_dev = cool_dev; cpufreq_dev->cpufreq_state = 0; + cpufreq_dev->request_status.devdata = devdata; mutex_lock(&cooling_cpufreq_lock); /* Register the notifier for first cpufreq cooling device */ @@ -614,3 +652,58 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) kfree(cpufreq_dev); } EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister); + +/** + * cpufreq_cooling_register_notifier - register a driver with cpufreq cooling. + * @nb: notifier function to register. + * @list: CPU_COOLING_STATE_NOTIFIER type. + * + * Add a driver to receive cpufreq cooling notifications like current state, + * max state and set state. The drivers after reading the events can perform + * some mapping between the P states and cooling states like grouping some P + * states into 1 cooling state. + * + * Return: 0 (success) + */ +int cpufreq_cooling_register_notifier(struct notifier_block *nb, + unsigned int list) +{ + int ret = 0; + switch (list) { + case CPU_COOLING_STATE_NOTIFIER: + ret = blocking_notifier_chain_register( + &cpufreq_cooling_state_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + return ret; +} +EXPORT_SYMBOL_GPL(cpufreq_cooling_register_notifier); + +/** + * cpufreq_cooling_unregister_notifier - unregisters a driver with cpufreq + * cooling. + * @nb: notifier function to unregister. + * @list: CPU_COOLING_STATE_NOTIFIER type. + * + * Removes a driver to receive further cpufreq cooling notifications. + * + * Return: 0 (success) + */ +int cpufreq_cooling_unregister_notifier(struct notifier_block *nb, + unsigned int list) +{ + int ret = 0; + switch (list) { + case CPU_COOLING_STATE_NOTIFIER: + ret = blocking_notifier_chain_unregister( + &cpufreq_cooling_state_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister_notifier); diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h index aaef7d8..f786935 100644 --- a/include/linux/cpu_cooling.h +++ b/include/linux/cpu_cooling.h @@ -28,6 +28,22 @@ #include <linux/thermal.h> #include <linux/cpumask.h> +#define CPU_COOLING_STATE_NOTIFIER (0) + +enum cpu_cooling_state_ops { + CPU_COOLING_SET_STATE_PRE, + CPU_COOLING_SET_STATE_POST, + CPU_COOLING_GET_CUR_STATE, + CPU_COOLING_GET_MAX_STATE, +}; + +struct cpufreq_cooling_status { + unsigned long cur_state; + unsigned long new_state; + unsigned long max_state; + void *devdata; +}; + #ifdef CONFIG_CPU_THERMAL /** * cpufreq_cooling_register - function to create cpufreq cooling device. @@ -62,6 +78,34 @@ of_cpufreq_cooling_register(struct device_node *np, void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev); unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq); + +/** + * cpufreq_cooling_register_notifier - register a driver with cpufreq cooling. + * @nb: notifier function to register. + * @list: CPU_COOLING_STATE_NOTIFIER type. + * + * Add a driver to receive cpufreq cooling notifications like current state, + * max state and set state. The drivers after reading the events can perform + * some mapping between the P states and cooling states like grouping some P + * states into 1 cooling state. + * + * Return: 0 (success) + */ +int cpufreq_cooling_register_notifier(struct notifier_block *nb, + unsigned int list); + +/** + * cpufreq_cooling_unregister_notifier - unregisters a driver with cpufreq + * cooling. + * @nb: notifier function to unregister. + * @list: CPU_COOLING_STATE_NOTIFIER type. + * + * Removes a driver to receive further cpufreq cooling notifications. + * + * Return: 0 (success) + */ +int cpufreq_cooling_unregister_notifier(struct notifier_block *nb, + unsigned int list); #else /* !CONFIG_CPU_THERMAL */ static inline struct thermal_cooling_device * cpufreq_cooling_register(const struct cpumask *clip_cpus, void *devdata) @@ -84,6 +128,17 @@ unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq) { return THERMAL_CSTATE_INVALID; } +static inline int +cpufreq_cooling_register_notifier(struct notifier_block *nb, unsigned int list) +{ + return 0; +} +static inline int +cpufreq_cooling_unregister_notifier(struct notifier_block *nb, + unsigned int list) +{ + return 0; +} #endif /* CONFIG_CPU_THERMAL */ #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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
