diff options
| -rw-r--r-- | drivers/thermal/devfreq_cooling.c | 105 | ||||
| -rw-r--r-- | include/linux/devfreq_cooling.h | 19 |
2 files changed, 101 insertions, 23 deletions
diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c index af9d32837a3a..26c31571a12c 100644 --- a/drivers/thermal/devfreq_cooling.c +++ b/drivers/thermal/devfreq_cooling.c @@ -28,6 +28,8 @@ #include <trace/events/thermal.h> +#define SCALE_ERROR_MITIGATION 100 + static DEFINE_IDA(devfreq_ida); /** @@ -45,6 +47,12 @@ static DEFINE_IDA(devfreq_ida); * @freq_table_size: Size of the @freq_table and @power_table * @power_ops: Pointer to devfreq_cooling_power, used to generate the * @power_table. + * @res_util: Resource utilization scaling factor for the power. + * It is multiplied by 100 to minimize the error. It is used + * for estimation of the power budget instead of using + * 'utilization' (which is 'busy_time / 'total_time'). + * The 'res_util' range is from 100 to (power_table[state] * 100) + * for the corresponding 'state'. */ struct devfreq_cooling_device { int id; @@ -55,6 +63,8 @@ struct devfreq_cooling_device { u32 *freq_table; size_t freq_table_size; struct devfreq_cooling_power *power_ops; + u32 res_util; + int capped_state; }; /** @@ -250,6 +260,16 @@ get_dynamic_power(struct devfreq_cooling_device *dfc, unsigned long freq, return power; } + +static inline unsigned long get_total_power(struct devfreq_cooling_device *dfc, + unsigned long freq, + unsigned long voltage) +{ + return get_static_power(dfc, freq) + get_dynamic_power(dfc, freq, + voltage); +} + + static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev, struct thermal_zone_device *tz, u32 *power) @@ -259,27 +279,55 @@ static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cd struct devfreq_dev_status *status = &df->last_status; unsigned long state; unsigned long freq = status->current_frequency; - u32 dyn_power, static_power; + unsigned long voltage; + u32 dyn_power = 0; + u32 static_power = 0; + int res; - /* Get dynamic power for state */ state = freq_get_state(dfc, freq); - if (state == THERMAL_CSTATE_INVALID) - return -EAGAIN; + if (state == THERMAL_CSTATE_INVALID) { + res = -EAGAIN; + goto fail; + } - dyn_power = dfc->power_table[state]; + if (dfc->power_ops->get_real_power) { + voltage = get_voltage(df, freq); + if (voltage == 0) { + res = -EINVAL; + goto fail; + } - /* Scale dynamic power for utilization */ - dyn_power = (dyn_power * status->busy_time) / status->total_time; + res = dfc->power_ops->get_real_power(df, power, freq, voltage); + if (!res) { + state = dfc->capped_state; + dfc->res_util = dfc->power_table[state]; + dfc->res_util *= SCALE_ERROR_MITIGATION; - /* Get static power */ - static_power = get_static_power(dfc, freq); + if (*power > 1) + dfc->res_util /= *power; + } else { + goto fail; + } + } else { + dyn_power = dfc->power_table[state]; + + /* Scale dynamic power for utilization */ + dyn_power *= status->busy_time; + dyn_power /= status->total_time; + /* Get static power */ + static_power = get_static_power(dfc, freq); + + *power = dyn_power + static_power; + } trace_thermal_power_devfreq_get_power(cdev, status, freq, dyn_power, static_power); - *power = dyn_power + static_power; - return 0; +fail: + /* It is safe to set max in this case */ + dfc->res_util = SCALE_ERROR_MITIGATION; + return res; } static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev, @@ -312,26 +360,34 @@ static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev, unsigned long busy_time; s32 dyn_power; u32 static_power; + s32 est_power; int i; - static_power = get_static_power(dfc, freq); + if (dfc->power_ops->get_real_power) { + /* Scale for resource utilization */ + est_power = power * dfc->res_util; + est_power /= SCALE_ERROR_MITIGATION; + } else { + static_power = get_static_power(dfc, freq); - dyn_power = power - static_power; - dyn_power = dyn_power > 0 ? dyn_power : 0; + dyn_power = power - static_power; + dyn_power = dyn_power > 0 ? dyn_power : 0; - /* Scale dynamic power for utilization */ - busy_time = status->busy_time ?: 1; - dyn_power = (dyn_power * status->total_time) / busy_time; + /* Scale dynamic power for utilization */ + busy_time = status->busy_time ?: 1; + est_power = (dyn_power * status->total_time) / busy_time; + } /* * Find the first cooling state that is within the power * budget for dynamic power. */ for (i = 0; i < dfc->freq_table_size - 1; i++) - if (dyn_power >= dfc->power_table[i]) + if (est_power >= dfc->power_table[i]) break; *state = i; + dfc->capped_state = i; trace_thermal_power_devfreq_limit(cdev, freq, *state, power); return 0; } @@ -387,7 +443,7 @@ static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc) } for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) { - unsigned long power_dyn, voltage; + unsigned long power, voltage; struct dev_pm_opp *opp; opp = dev_pm_opp_find_freq_floor(dev, &freq); @@ -400,12 +456,15 @@ static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc) dev_pm_opp_put(opp); if (dfc->power_ops) { - power_dyn = get_dynamic_power(dfc, freq, voltage); + if (dfc->power_ops->get_real_power) + power = get_total_power(dfc, freq, voltage); + else + power = get_dynamic_power(dfc, freq, voltage); - dev_dbg(dev, "Dynamic power table: %lu MHz @ %lu mV: %lu = %lu mW\n", - freq / 1000000, voltage, power_dyn, power_dyn); + dev_dbg(dev, "Power table: %lu MHz @ %lu mV: %lu = %lu mW\n", + freq / 1000000, voltage, power, power); - power_table[i] = power_dyn; + power_table[i] = power; } freq_table[i] = freq; diff --git a/include/linux/devfreq_cooling.h b/include/linux/devfreq_cooling.h index c35d0c0e0ada..4635f95000a4 100644 --- a/include/linux/devfreq_cooling.h +++ b/include/linux/devfreq_cooling.h @@ -34,6 +34,23 @@ * If get_dynamic_power() is NULL, then the * dynamic power is calculated as * @dyn_power_coeff * frequency * voltage^2 + * @get_real_power: When this is set, the framework uses it to ask the + * device driver for the actual power. + * Some devices have more sophisticated methods + * (like power counters) to approximate the actual power + * that they use. + * This function provides more accurate data to the + * thermal governor. When the driver does not provide + * such function, framework just uses pre-calculated + * table and scale the power by 'utilization' + * (based on 'busy_time' and 'total_time' taken from + * devfreq 'last_status'). + * The value returned by this function must be lower + * or equal than the maximum power value + * for the current state + * (which can be found in power_table[state]). + * When this interface is used, the power_table holds + * max total (static + dynamic) power value for each OPP. */ struct devfreq_cooling_power { unsigned long (*get_static_power)(struct devfreq *devfreq, @@ -41,6 +58,8 @@ struct devfreq_cooling_power { unsigned long (*get_dynamic_power)(struct devfreq *devfreq, unsigned long freq, unsigned long voltage); + int (*get_real_power)(struct devfreq *df, u32 *power, + unsigned long freq, unsigned long voltage); unsigned long dyn_power_coeff; }; |