Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756550AbaLILAw (ORCPT ); Tue, 9 Dec 2014 06:00:52 -0500 Received: from service87.mimecast.com ([91.220.42.44]:42854 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756176AbaLILAt convert rfc822-to-8bit (ORCPT ); Tue, 9 Dec 2014 06:00:49 -0500 From: "Javi Merino" Date: Tue, 9 Dec 2014 11:00:43 +0000 To: Viresh Kumar Cc: Linux PM list , "linux-kernel@vger.kernel.org" , Punit Agrawal , Mark Brown , Zhang Rui , Eduardo Valentin Subject: Re: [RFC PATCH v6 6/9] thermal: cpu_cooling: implement the power cooling device API Message-ID: <20141209110043.GD2891@e104805> References: <1417806260-9264-1-git-send-email-javi.merino@arm.com> <1417806260-9264-7-git-send-email-javi.merino@arm.com> <20141208125033.GB2980@e104805> <20141208142217.GA1831@e104805> <20141209103249.GB2891@e104805> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginalArrivalTime: 09 Dec 2014 11:00:43.0786 (UTC) FILETIME=[60C2EEA0:01D0139F] X-MC-Unique: 114120911004700501 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 09, 2014 at 10:36:46AM +0000, Viresh Kumar wrote: > On 9 December 2014 at 16:02, Javi Merino wrote: > > Sorry but I don't follow. __cpufreq_cooling_register() is passed a > > clip_cpus mask, not a single cpu. How do I get "the cpu for which > > __cpufreq_cooling_register() is called" if not by looping through all > > the cpus in the mask? > > Yeah, its np that is passed instead of cpu number. So, that wouldn't > be usable. Also because of the limitations I explained earlier, it makes > sense to iterate over all clip_cpus and finding which one owns OPPs. Ok, how about this then? I've pasted the whole commit so as to avoid confusion. diff --git a/Documentation/thermal/cpu-cooling-api.txt b/Documentation/thermal/cpu-cooling-api.txt index fca24c931ec8..d438a900e374 100644 --- a/Documentation/thermal/cpu-cooling-api.txt +++ b/Documentation/thermal/cpu-cooling-api.txt @@ -25,8 +25,150 @@ the user. The registration APIs returns the cooling device pointer. clip_cpus: cpumask of cpus where the frequency constraints will happen. -1.1.2 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) +1.1.2 struct thermal_cooling_device *cpufreq_power_cooling_register( + const struct cpumask *clip_cpus, u32 capacitance, + get_static_t plat_static_func) + +Similar to cpufreq_cooling_register, this function registers a cpufreq +cooling device. Using this function, the cooling device will +implement the power extensions by using a simple cpu power model. The +cpus must have registered their OPPs using the OPP library. + +The additional parameters are needed for the power model (See 2. Power +models). "capacitance" is the dynamic power coefficient (See 2.1 +Dynamic power). "plat_static_func" is a function to calculate the +static power consumed by these cpus (See 2.2 Static power). + +1.1.3 struct thermal_cooling_device *of_cpufreq_power_cooling_register( + struct device_node *np, const struct cpumask *clip_cpus, u32 capacitance, + get_static_t plat_static_func) + +Similar to cpufreq_power_cooling_register, this function register a +cpufreq cooling device with power extensions using the device tree +information supplied by the np parameter. + +1.1.4 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. + +2. Power models + +The power API registration functions provide a simple power model for +CPUs. The current power is calculated as dynamic + (optionally) +static power. This power model requires that the operating-points of +the CPUs are registered using the kernel's opp library and the +`cpufreq_frequency_table` is assigned to the `struct device` of the +cpu. If you are using the `cpufreq-cpu0.c` driver then the +`cpufreq_frequency_table` should already be assigned to the cpu +device. + +The `plat_static_func` parameter of `cpufreq_power_cooling_register()` +and `of_cpufreq_power_cooling_register()` is optional. If you don't +provide it, only dynamic power will be considered. + +2.1 Dynamic power + +The dynamic power consumption of a processor depends on many factors. +For a given processor implementation the primary factors are: + +- The time the processor spends running, consuming dynamic power, as + compared to the time in idle states where dynamic consumption is + negligible. Herein we refer to this as 'utilisation'. +- The voltage and frequency levels as a result of DVFS. The DVFS + level is a dominant factor governing power consumption. +- In running time the 'execution' behaviour (instruction types, memory + access patterns and so forth) causes, in most cases, a second order + variation. In pathological cases this variation can be significant, + but typically it is of a much lesser impact than the factors above. + +A high level dynamic power consumption model may then be represented as: + +Pdyn = f(run) * Voltage^2 * Frequency * Utilisation + +f(run) here represents the described execution behaviour and its +result has a units of Watts/Hz/Volt^2 (this often expressed in +mW/MHz/uVolt^2) + +The detailed behaviour for f(run) could be modelled on-line. However, +in practice, such an on-line model has dependencies on a number of +implementation specific processor support and characterisation +factors. Therefore, in initial implementation that contribution is +represented as a constant coefficient. This is a simplification +consistent with the relative contribution to overall power variation. + +In this simplified representation our model becomes: + +Pdyn = Kd * Voltage^2 * Frequency * Utilisation + +Where Kd (capacitance) represents an indicative running time dynamic +power coefficient in fundamental units of mW/MHz/uVolt^2 + +2.2 Static power + +Static leakage power consumption depends on a number of factors. For a +given circuit implementation the primary factors are: + +- Time the circuit spends in each 'power state' +- Temperature +- Operating voltage +- Process grade + +The time the circuit spends in each 'power state' for a given +evaluation period at first order means OFF or ON. However, +'retention' states can also be supported that reduce power during +inactive periods without loss of context. + +Note: The visibility of state entries to the OS can vary, according to +platform specifics, and this can then impact the accuracy of a model +based on OS state information alone. It might be possible in some +cases to extract more accurate information from system resources. + +The temperature, operating voltage and process 'grade' (slow to fast) +of the circuit are all significant factors in static leakage power +consumption. All of these have complex relationships to static power. + +Circuit implementation specific factors include the chosen silicon +process as well as the type, number and size of transistors in both +the logic gates and any RAM elements included. + +The static power consumption modelling must take into account the +power managed regions that are implemented. Taking the example of an +ARM processor cluster, the modelling would take into account whether +each CPU can be powered OFF separately or if only a single power +region is implemented for the complete cluster. + +In one view, there are others, a static power consumption model can +then start from a set of reference values for each power managed +region (e.g. CPU, Cluster/L2) in each state (e.g. ON, OFF) at an +arbitrary process grade, voltage and temperature point. These values +are then scaled for all of the following: the time in each state, the +process grade, the current temperature and the operating voltage. +However, since both implementation specific and complex relationships +dominate the estimate, the appropriate interface to the model from the +cpu cooling device is to provide a function callback that calculates +the static power in this platform. When registering the cpu cooling +device pass a function pointer that follows the `get_static_t` +prototype: + + u32 plat_get_static(cpumask_t *cpumask, unsigned long voltage); + +with `cpumask` a cpumask of the cpus involved in the calculation and +`voltage` the voltage at which they are operating. + +If `plat_static_func` is NULL, static power is considered to be +negligible for this platform and only dynamic power is considered. + +The platform specific callback can then use any combination of tables +and/or equations to permute the estimated value. Process grade +information is not passed to the model since access to such data, from +on-chip measurement capability or manufacture time data, is platform +specific. + +Note: the significance of static power for CPUs in comparison to +dynamic power is highly dependent on implementation. Given the +potential complexity in implementation, the importance and accuracy of +its inclusion when using cpu cooling devices should be assessed on a +case by cases basis. + diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c index ad09e51ffae4..959a103d18ba 100644 --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -24,11 +24,25 @@ #include #include #include +#include #include #include #include /** + * struct power_table - frequency to power conversion + * @frequency: frequency in KHz + * @power: power in mW + * + * This structure is built when the cooling device registers and helps + * in translating frequency to power and viceversa. + */ +struct power_table { + u32 frequency; + u32 power; +}; + +/** * struct cpufreq_cooling_device - data for cooling device with cpufreq * @id: unique integer value corresponding to each cpufreq_cooling_device * registered. @@ -39,6 +53,15 @@ * @cpufreq_val: integer value representing the absolute value of the clipped * frequency. * @allowed_cpus: all the cpus involved for this cpufreq_cooling_device. + * @last_load: load measured by the latest call to cpufreq_get_actual_power() + * @time_in_idle: previous reading of the absolute time that this cpu was idle + * @time_in_idle_timestamp: wall time of the last invocation of + * get_cpu_idle_time_us() + * @dyn_power_table: array of struct power_table for frequency to power + * conversion + * @dyn_power_table_entries: number of entries in the @dyn_power_table array + * @cpu_dev: the first cpu_device from @allowed_cpus that has OPPs registered + * @plat_get_static_power: callback to calculate the static power * * This structure is required for keeping information of each * cpufreq_cooling_device registered. In order to prevent corruption of this a @@ -51,6 +74,13 @@ struct cpufreq_cooling_device { unsigned int cpufreq_val; struct cpumask allowed_cpus; struct list_head node; + u32 last_load; + u64 time_in_idle[NR_CPUS]; + u64 time_in_idle_timestamp[NR_CPUS]; + struct power_table *dyn_power_table; + int dyn_power_table_entries; + struct device *cpu_dev; + get_static_t plat_get_static_power; }; static DEFINE_IDR(cpufreq_idr); static DEFINE_MUTEX(cooling_cpufreq_lock); @@ -338,6 +368,204 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb, return 0; } +/** + * build_dyn_power_table() - create a dynamic power to frequency table + * @cpufreq_device: the cpufreq cooling device in which to store the table + * @capacitance: dynamic power coefficient for these cpus + * + * Build a dynamic power to frequency table for this cpu and store it + * in @cpufreq_device. This table will be used in cpu_power_to_freq() and + * cpu_freq_to_power() to convert between power and frequency + * efficiently. Power is stored in mW, frequency in KHz. The + * resulting table is in ascending order. + * + * Return: 0 on success, -E* on error. + */ +static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device, + u32 capacitance) +{ + struct power_table *power_table; + struct dev_pm_opp *opp; + struct device *dev = NULL; + int num_opps = 0, cpu, i, ret = 0; + unsigned long freq; + + rcu_read_lock(); + + for_each_cpu(cpu, &cpufreq_device->allowed_cpus) { + dev = get_cpu_device(cpu); + if (!dev) { + dev_warn(&cpufreq_device->cool_dev->device, + "No cpu device for cpu %d\n", cpu); + continue; + } + + num_opps = dev_pm_opp_get_opp_count(dev); + if (num_opps > 0) { + break; + } else if (num_opps < 0) { + ret = num_opps; + goto unlock; + } + } + + if (num_opps == 0) { + ret = -EINVAL; + goto unlock; + } + + power_table = devm_kcalloc(&cpufreq_device->cool_dev->device, num_opps, + sizeof(*power_table), GFP_KERNEL); + + for (freq = 0, i = 0; + opp = dev_pm_opp_find_freq_ceil(dev, &freq), !IS_ERR(opp); + freq++, i++) { + u32 freq_mhz, voltage_mv; + u64 power; + + freq_mhz = freq / 1000000; + voltage_mv = dev_pm_opp_get_voltage(opp) / 1000; + + /* + * Do the multiplication with MHz and millivolt so as + * to not overflow. + */ + power = (u64)capacitance * freq_mhz * voltage_mv * voltage_mv; + do_div(power, 1000000000); + + /* frequency is stored in power_table in KHz */ + power_table[i].frequency = freq / 1000; + power_table[i].power = power; + } + + if (i == 0) { + ret = PTR_ERR(opp); + goto unlock; + } + + cpufreq_device->cpu_dev = dev; + cpufreq_device->dyn_power_table = power_table; + cpufreq_device->dyn_power_table_entries = i; + +unlock: + rcu_read_unlock(); + return ret; +} + +static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_device, + u32 freq) +{ + int i; + struct power_table *pt = cpufreq_device->dyn_power_table; + + for (i = 1; i < cpufreq_device->dyn_power_table_entries; i++) + if (freq < pt[i].frequency) + break; + + return pt[i - 1].power; +} + +static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_device, + u32 power) +{ + int i; + struct power_table *pt = cpufreq_device->dyn_power_table; + + for (i = 1; i < cpufreq_device->dyn_power_table_entries; i++) + if (power < pt[i].power) + break; + + return pt[i - 1].frequency; +} + +/** + * get_load() - get load for a cpu since last updated + * @cpufreq_device: &struct cpufreq_cooling_device for this cpu + * @cpu: cpu number + * + * Return: The average load of cpu @cpu in percentage since this + * function was last called. + */ +static u32 get_load(struct cpufreq_cooling_device *cpufreq_device, int cpu) +{ + u32 load; + u64 now, now_idle, delta_time, delta_idle; + + now_idle = get_cpu_idle_time(cpu, &now, 0); + delta_idle = now_idle - cpufreq_device->time_in_idle[cpu]; + delta_time = now - cpufreq_device->time_in_idle_timestamp[cpu]; + + if (delta_time <= delta_idle) + load = 0; + else + load = div64_u64(100 * (delta_time - delta_idle), delta_time); + + cpufreq_device->time_in_idle[cpu] = now_idle; + cpufreq_device->time_in_idle_timestamp[cpu] = now; + + return load; +} + +/** + * get_static_power() - calculate the static power consumed by the cpus + * @cpufreq_device: struct &cpufreq_cooling_device for this cpu cdev + * @freq: frequency in KHz + * + * Calculate the static power consumed by the cpus described by + * @cpu_actor running at frequency @freq. This function relies on a + * platform specific function that should have been provided when the + * actor was registered. If it wasn't, the static power is assumed to + * be negligible. + * + * Return: The static power consumed by the cpus. It returns 0 on + * error or if there is no plat_get_static_power(). + */ +static u32 get_static_power(struct cpufreq_cooling_device *cpufreq_device, + unsigned long freq) +{ + struct dev_pm_opp *opp; + unsigned long voltage; + struct cpumask *cpumask = &cpufreq_device->allowed_cpus; + unsigned long freq_hz = freq * 1000; + + if (!cpufreq_device->plat_get_static_power) + return 0; + + rcu_read_lock(); + + opp = dev_pm_opp_find_freq_exact(cpufreq_device->cpu_dev, freq_hz, + true); + voltage = dev_pm_opp_get_voltage(opp); + + rcu_read_unlock(); + + if (voltage == 0) { + dev_warn_ratelimited(cpufreq_device->cpu_dev, + "Failed to get voltage for frequency %lu: %ld\n", + freq_hz, IS_ERR(opp) ? PTR_ERR(opp) : 0); + return 0; + } + + return cpufreq_device->plat_get_static_power(cpumask, voltage); +} + +/** + * get_dynamic_power() - calculate the dynamic power + * @cpufreq_device: &cpufreq_cooling_device for this cdev + * @freq: current frequency + * + * Return: the dynamic power consumed by the cpus described by + * @cpufreq_device. + */ +static u32 get_dynamic_power(struct cpufreq_cooling_device *cpufreq_device, + unsigned long freq) +{ + u32 raw_cpu_power; + + raw_cpu_power = cpu_freq_to_power(cpufreq_device, freq); + return (raw_cpu_power * cpufreq_device->last_load) / 100; +} + /* cpufreq cooling device callback functions are defined below */ /** @@ -407,8 +635,106 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, return cpufreq_apply_cooling(cpufreq_device, state); } +/** + * cpufreq_get_actual_power() - get the current power + * @cdev: &thermal_cooling_device pointer + * + * Return the current power consumption of the cpus in milliwatts. + */ +static u32 cpufreq_get_actual_power(struct thermal_cooling_device *cdev) +{ + unsigned long freq; + int cpu; + u32 static_power, dynamic_power, total_load = 0; + struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; + + freq = cpufreq_quick_get(cpumask_any(&cpufreq_device->allowed_cpus)); + + for_each_cpu(cpu, &cpufreq_device->allowed_cpus) { + u32 load; + + if (cpu_online(cpu)) + load = get_load(cpufreq_device, cpu); + else + load = 0; + + total_load += load; + } + + cpufreq_device->last_load = total_load; + + static_power = get_static_power(cpufreq_device, freq); + dynamic_power = get_dynamic_power(cpufreq_device, freq); + + return static_power + dynamic_power; +} + +/** + * cpufreq_state2power() - convert a cpu cdev state to power consumed + * @cdev: &thermal_cooling_device pointer + * @state: cooling device state to be converted + * + * Convert cooling device state @state into power consumption in milliwatts. + */ +static u32 cpufreq_state2power(struct thermal_cooling_device *cdev, + unsigned long state) +{ + unsigned int freq, num_cpus; + cpumask_t cpumask; + u32 static_power, dynamic_power; + struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; + + cpumask_and(&cpumask, &cpufreq_device->allowed_cpus, cpu_online_mask); + num_cpus = cpumask_weight(&cpumask); + + freq = get_cpu_frequency(cpumask_any(&cpumask), state); + if (!freq) + return 0; + + static_power = get_static_power(cpufreq_device, freq); + dynamic_power = cpu_freq_to_power(cpufreq_device, freq) * num_cpus; + + return static_power + dynamic_power; +} + +/** + * cpufreq_power2state() - convert power to a cooling device state + * @cdev: &thermal_cooling_device pointer + * @power: power in milliwatts to be converted + * + * Calculate a cooling device state for the cpus described by @cdev + * that would allow them to consume at most @power mW. + */ +static unsigned long cpufreq_power2state(struct thermal_cooling_device *cdev, + u32 power) +{ + unsigned int cpu, cur_freq, target_freq; + s32 dyn_power; + u32 last_load, normalised_power; + unsigned long cdev_state; + struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; + + cpu = cpumask_any_and(&cpufreq_device->allowed_cpus, cpu_online_mask); + + cur_freq = cpufreq_quick_get(cpu); + dyn_power = power - get_static_power(cpufreq_device, cur_freq); + dyn_power = dyn_power > 0 ? dyn_power : 0; + last_load = cpufreq_device->last_load ?: 1; + normalised_power = (dyn_power * 100) / last_load; + target_freq = cpu_power_to_freq(cpufreq_device, normalised_power); + + cdev_state = cpufreq_cooling_get_level(cpu, target_freq); + if (cdev_state == THERMAL_CSTATE_INVALID) { + pr_err_ratelimited("Failed to convert %dKHz for cpu %d into a cdev state\n", + target_freq, cpu); + return 0; + } + + return cdev_state; +} + /* Bind cpufreq callbacks to thermal cooling device ops */ -static struct thermal_cooling_device_ops const cpufreq_cooling_ops = { +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, @@ -434,7 +760,8 @@ static struct notifier_block thermal_cpufreq_notifier_block = { */ static struct thermal_cooling_device * __cpufreq_cooling_register(struct device_node *np, - const struct cpumask *clip_cpus) + const struct cpumask *clip_cpus, u32 capacitance, + get_static_t plat_static_func) { struct thermal_cooling_device *cool_dev; struct cpufreq_cooling_device *cpufreq_dev = NULL; @@ -464,10 +791,23 @@ __cpufreq_cooling_register(struct device_node *np, cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus); + if (capacitance) { + cpufreq_cooling_ops.get_actual_power = cpufreq_get_actual_power; + cpufreq_cooling_ops.state2power = cpufreq_state2power; + cpufreq_cooling_ops.power2state = cpufreq_power2state; + cpufreq_dev->plat_get_static_power = plat_static_func; + + ret = build_dyn_power_table(cpufreq_dev, capacitance); + if (ret) { + cool_dev = ERR_PTR(ret); + goto free; + } + } + ret = get_idr(&cpufreq_idr, &cpufreq_dev->id); if (ret) { - kfree(cpufreq_dev); - return ERR_PTR(-EINVAL); + cool_dev = ERR_PTR(-EINVAL); + goto free; } snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d", @@ -475,11 +815,8 @@ __cpufreq_cooling_register(struct device_node *np, 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 cool_dev; - } + if (IS_ERR(cool_dev)) + goto release_idr; cpufreq_dev->cool_dev = cool_dev; cpufreq_dev->cpufreq_state = 0; mutex_lock(&cooling_cpufreq_lock); @@ -494,6 +831,12 @@ __cpufreq_cooling_register(struct device_node *np, mutex_unlock(&cooling_cpufreq_lock); return cool_dev; + +release_idr: + release_idr(&cpufreq_idr, cpufreq_dev->id); +free: + kfree(cpufreq_dev); + return cool_dev; } /** @@ -510,7 +853,7 @@ __cpufreq_cooling_register(struct device_node *np, struct thermal_cooling_device * cpufreq_cooling_register(const struct cpumask *clip_cpus) { - return __cpufreq_cooling_register(NULL, clip_cpus); + return __cpufreq_cooling_register(NULL, clip_cpus, 0, NULL); } EXPORT_SYMBOL_GPL(cpufreq_cooling_register); @@ -534,11 +877,77 @@ of_cpufreq_cooling_register(struct device_node *np, if (!np) return ERR_PTR(-EINVAL); - return __cpufreq_cooling_register(np, clip_cpus); + return __cpufreq_cooling_register(np, clip_cpus, 0, NULL); } EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register); /** + * cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions + * @clip_cpus: cpumask of cpus where the frequency constraints will happen + * @capacitance: dynamic power coefficient for these cpus + * @plat_static_func: function to calculate the static power consumed by these + * cpus (optional) + * + * 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 function, the + * cooling device will implement the power extensions by using a + * simple cpu power model. The cpus must have registered their OPPs + * using the OPP library. + * + * An optional @plat_static_func may be provided to calculate the + * static power consumed by these cpus. If the platform's static + * power consumption is unknown or negligible, make it NULL. + * + * Return: a valid struct thermal_cooling_device pointer on success, + * on failure, it returns a corresponding ERR_PTR(). + */ +struct thermal_cooling_device * +cpufreq_power_cooling_register(const struct cpumask *clip_cpus, u32 capacitance, + get_static_t plat_static_func) +{ + return __cpufreq_cooling_register(NULL, clip_cpus, capacitance, + plat_static_func); +} +EXPORT_SYMBOL(cpufreq_power_cooling_register); + +/** + * of_cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions + * @np: a valid struct device_node to the cooling device device tree node + * @clip_cpus: cpumask of cpus where the frequency constraints will happen + * @capacitance: dynamic power coefficient for these cpus + * @plat_static_func: function to calculate the static power consumed by these + * cpus (optional) + * + * 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. + * Using this function, the cooling device will implement the power + * extensions by using a simple cpu power model. The cpus must have + * registered their OPPs using the OPP library. + * + * An optional @plat_static_func may be provided to calculate the + * static power consumed by these cpus. If the platform's static + * power consumption is unknown or negligible, make it NULL. + * + * Return: a valid struct thermal_cooling_device pointer on success, + * on failure, it returns a corresponding ERR_PTR(). + */ +struct thermal_cooling_device * +of_cpufreq_power_cooling_register(struct device_node *np, + const struct cpumask *clip_cpus, u32 capacitance, + get_static_t plat_static_func) +{ + if (!np) + return ERR_PTR(-EINVAL); + + return __cpufreq_cooling_register(np, clip_cpus, capacitance, + plat_static_func); +} +EXPORT_SYMBOL(of_cpufreq_power_cooling_register); + +/** * cpufreq_cooling_unregister - function to remove cpufreq cooling device. * @cdev: thermal cooling device pointer. * diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h index c303d383def1..5c4f4567acf0 100644 --- a/include/linux/cpu_cooling.h +++ b/include/linux/cpu_cooling.h @@ -28,6 +28,8 @@ #include #include +typedef u32 (*get_static_t)(cpumask_t *cpumask, unsigned long voltage); + #ifdef CONFIG_CPU_THERMAL /** * cpufreq_cooling_register - function to create cpufreq cooling device. @@ -37,14 +39,38 @@ struct thermal_cooling_device * cpufreq_cooling_register(const struct cpumask *clip_cpus); /** + * cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions + * @clip_cpus: cpumask of cpus where the frequency constraints will happen + * @capacitance: dynamic power coefficient for these cpus + * @plat_static_func: function to calculate the static power consumed by these + * cpus (optional) + */ +struct thermal_cooling_device * +cpufreq_power_cooling_register(const struct cpumask *clip_cpus, + u32 capacitance, get_static_t plat_static_func); + +#ifdef CONFIG_THERMAL_OF +/** * of_cpufreq_cooling_register - create cpufreq cooling device based on DT. * @np: a valid struct device_node to the cooling device device tree node. * @clip_cpus: cpumask of cpus where the frequency constraints will happen */ -#ifdef CONFIG_THERMAL_OF struct thermal_cooling_device * of_cpufreq_cooling_register(struct device_node *np, const struct cpumask *clip_cpus); + +/** + * of_cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions + * @np: a valid struct device_node to the cooling device device tree node + * @clip_cpus: cpumask of cpus where the frequency constraints will happen + * @capacitance: dynamic power coefficient for these cpus + * @plat_static_func: function to calculate the static power consumed by these + * cpus (optional) + */ +struct thermal_cooling_device * +of_cpufreq_power_cooling_register(struct device_node *np, + const struct cpumask *clip_cpus, + u32 capacitance, get_static_t plat_static_func); #else static inline struct thermal_cooling_device * of_cpufreq_cooling_register(struct device_node *np, @@ -52,6 +78,14 @@ of_cpufreq_cooling_register(struct device_node *np, { return NULL; } + +struct thermal_cooling_device * +of_cpufreq_power_cooling_register(struct device_node *np, + const struct cpumask *clip_cpus, + u32 capacitance, get_static_t plat_static_func) +{ + return NULL; +} #endif /** @@ -68,11 +102,24 @@ cpufreq_cooling_register(const struct cpumask *clip_cpus) return NULL; } static inline struct thermal_cooling_device * +cpufreq_power_cooling_register(const struct cpumask *clip_cpus, + u32 capacitance, get_static_t plat_static_func) +{ + return NULL; +} +static inline struct thermal_cooling_device * of_cpufreq_cooling_register(struct device_node *np, const struct cpumask *clip_cpus) { return NULL; } +static inline struct thermal_cooling_device * +of_cpufreq_power_cooling_register(struct device_node *np, + const struct cpumask *clip_cpus, + u32 capacitance, get_static_t plat_static_func) +{ + return NULL; +} static inline void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) { -- 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/