@@ -1,17 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* devfreq_cooling: Thermal cooling device implementation for devices using
* devfreq
*
- * Copyright (C) 2014-2015 ARM Limited
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * Copyright (C) 2014-2020 ARM Limited
*
* TODO:
* - If OPPs are added or removed after devfreq cooling has
@@ -20,6 +12,7 @@
#include <linux/devfreq.h>
#include <linux/devfreq_cooling.h>
+#include <linux/energy_model.h>
#include <linux/export.h>
#include <linux/idr.h>
#include <linux/slab.h>
@@ -39,37 +32,56 @@ static DEFINE_IDA(devfreq_ida);
* @cdev: Pointer to associated thermal cooling device.
* @devfreq: Pointer to associated devfreq device.
* @cooling_state: Current cooling state.
- * @power_table: Pointer to table with maximum power draw for each
- * cooling state. State is the index into the table, and
- * the power is in mW.
- * @freq_table: Pointer to a table with the frequencies sorted in descending
- * order. You can index the table by cooling device state
- * @freq_table_size: Size of the @freq_table and @power_table
- * @power_ops: Pointer to devfreq_cooling_power, used to generate the
- * @power_table.
+ * @freq_table: Pointer to a table with the frequencies.
+ * @max_level: It is the last index, that is, one less than the number of the
+ * OPPs
+ * @power_ops: Pointer to devfreq_cooling_power, a more precised model.
* @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'.
- * @capped_state: index to cooling state with in dynamic power budget
+ * The 'res_util' range is from 100 to power * 100 for the
+ * corresponding 'state'.
+ * @em: Energy Model which represents the associated Devfreq device
*/
struct devfreq_cooling_device {
int id;
struct thermal_cooling_device *cdev;
struct devfreq *devfreq;
unsigned long cooling_state;
- u32 *power_table;
u32 *freq_table;
- size_t freq_table_size;
+ size_t max_level;
struct devfreq_cooling_power *power_ops;
u32 res_util;
- int capped_state;
+ struct em_perf_domain *em;
};
+static unsigned long _find_freq_for_state(struct devfreq_cooling_device *dfc,
+ unsigned long cdev_state)
+{
+ unsigned long freq;
+
+ if (dfc->em) {
+ freq = dfc->em->table[dfc->max_level - cdev_state].frequency;
+ /* Energy Model frequencies are in kHz */
+ return freq * 1000;
+ } else {
+ return dfc->freq_table[cdev_state];
+ }
+}
+
+static void _update_devfreq_max_freq(struct devfreq *df, unsigned long max_freq)
+{
+ dev_dbg(df->dev.parent, "devfreq_cooling: max_freq=%luHz\n", max_freq);
+
+ mutex_lock(&df->lock);
+ df->scaling_max_freq = max_freq;
+ update_devfreq(df);
+ mutex_unlock(&df->lock);
+}
+
/**
- * partition_enable_opps() - disable all opps above a given state
+ * partition_enable_opps() - disable all OPPs above a given state
* @dfc: Pointer to devfreq we are operating on
* @cdev_state: cooling device state we're setting
*
@@ -79,16 +91,33 @@ struct devfreq_cooling_device {
static int partition_enable_opps(struct devfreq_cooling_device *dfc,
unsigned long cdev_state)
{
- int i;
struct device *dev = dfc->devfreq->dev.parent;
+ bool want_enable, available;
+ struct dev_pm_opp *opp;
+ unsigned long freq;
+ int i, ret;
- for (i = 0; i < dfc->freq_table_size; i++) {
- struct dev_pm_opp *opp;
- int ret = 0;
- unsigned int freq = dfc->freq_table[i];
- bool want_enable = i >= cdev_state ? true : false;
+ /*
+ * Avoid race with devfreq governors trying to use OPPs which are
+ * going to be disabled. Update devfreq upfront when previous cooling
+ * state had higher frequency or do it later in opposite case.
+ */
+ freq = _find_freq_for_state(dfc, cdev_state);
+
+ if (dfc->cooling_state < cdev_state)
+ _update_devfreq_max_freq(dfc->devfreq, freq);
- opp = dev_pm_opp_find_freq_exact(dev, freq, !want_enable);
+ dev_dbg(dev, "devfreq_cooling: updating OPPs\n");
+ for (i = 0; i <= dfc->max_level; i++) {
+ available = (i >= dfc->cooling_state);
+ want_enable = (i >= cdev_state);
+
+ if (available == want_enable)
+ continue;
+
+ freq = _find_freq_for_state(dfc, i);
+
+ opp = dev_pm_opp_find_freq_exact(dev, freq, available);
if (PTR_ERR(opp) == -ERANGE)
continue;
@@ -106,6 +135,9 @@ static int partition_enable_opps(struct devfreq_cooling_device *dfc,
return ret;
}
+ if (dfc->cooling_state > cdev_state)
+ _update_devfreq_max_freq(dfc->devfreq, freq);
+
return 0;
}
@@ -114,7 +146,7 @@ static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev,
{
struct devfreq_cooling_device *dfc = cdev->devdata;
- *state = dfc->freq_table_size - 1;
+ *state = dfc->max_level;
return 0;
}
@@ -142,7 +174,7 @@ static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev,
dev_dbg(dev, "Setting cooling state %lu\n", state);
- if (state >= dfc->freq_table_size)
+ if (state > dfc->max_level)
return -EINVAL;
ret = partition_enable_opps(dfc, state);
@@ -155,20 +187,20 @@ static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev,
}
/**
- * freq_get_state() - get the cooling state corresponding to a frequency
+ * freq_get_state() - get the performance index corresponding to a frequency
* @dfc: Pointer to devfreq cooling device
- * @freq: frequency in Hz
+ * @freq: frequency in kHz
*
- * Return: the cooling state associated with the @freq, or
+ * Return: the performance index associated with the @freq, or
* THERMAL_CSTATE_INVALID if it wasn't found.
*/
-static unsigned long
+static int
freq_get_state(struct devfreq_cooling_device *dfc, unsigned long freq)
{
int i;
- for (i = 0; i < dfc->freq_table_size; i++) {
- if (dfc->freq_table[i] == freq)
+ for (i = 0; i <= dfc->max_level; i++) {
+ if (dfc->em->table[i].frequency == freq)
return i;
}
@@ -203,132 +235,79 @@ static unsigned long get_voltage(struct devfreq *df, unsigned long freq)
return voltage;
}
-/**
- * get_static_power() - calculate the static power
- * @dfc: Pointer to devfreq cooling device
- * @freq: Frequency in Hz
- *
- * Calculate the static power in milliwatts using the supplied
- * get_static_power(). The current voltage is calculated using the
- * OPP library. If no get_static_power() was supplied, assume the
- * static power is negligible.
- */
-static unsigned long
-get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq)
-{
- struct devfreq *df = dfc->devfreq;
- unsigned long voltage;
-
- if (!dfc->power_ops->get_static_power)
- return 0;
-
- voltage = get_voltage(df, freq);
-
- if (voltage == 0)
- return 0;
-
- return dfc->power_ops->get_static_power(df, voltage);
-}
-
-/**
- * get_dynamic_power - calculate the dynamic power
- * @dfc: Pointer to devfreq cooling device
- * @freq: Frequency in Hz
- * @voltage: Voltage in millivolts
- *
- * Calculate the dynamic power in milliwatts consumed by the device at
- * frequency @freq and voltage @voltage. If the get_dynamic_power()
- * was supplied as part of the devfreq_cooling_power struct, then that
- * function is used. Otherwise, a simple power model (Pdyn = Coeff *
- * Voltage^2 * Frequency) is used.
- */
-static unsigned long
-get_dynamic_power(struct devfreq_cooling_device *dfc, unsigned long freq,
- unsigned long voltage)
+static void dfc_em_get_requested_power(struct em_perf_domain *em,
+ struct devfreq_dev_status *status,
+ u32 *power, int em_perf_idx)
{
- u64 power;
- u32 freq_mhz;
- struct devfreq_cooling_power *dfc_power = dfc->power_ops;
+ unsigned long total_time;
+ u64 current_power;
- if (dfc_power->get_dynamic_power)
- return dfc_power->get_dynamic_power(dfc->devfreq, freq,
- voltage);
+ total_time = status->total_time ?: 1;
- freq_mhz = freq / 1000000;
- power = (u64)dfc_power->dyn_power_coeff * freq_mhz * voltage * voltage;
- do_div(power, 1000000000);
-
- return power;
-}
+ current_power = em->table[em_perf_idx].power;
+ /* Scale power for utilization */
+ current_power *= status->busy_time;
+ current_power = do_div(current_power, total_time);
-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);
+ *power = current_power;
}
-
static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev,
struct thermal_zone_device *tz,
u32 *power)
{
struct devfreq_cooling_device *dfc = cdev->devdata;
struct devfreq *df = dfc->devfreq;
- struct devfreq_dev_status *status = &df->last_status;
- unsigned long state;
- unsigned long freq = status->current_frequency;
- unsigned long voltage;
- u32 dyn_power = 0;
- u32 static_power = 0;
+ struct devfreq_dev_status status;
+ unsigned long voltage, freq;
+ int em_perf_idx;
int res;
- state = freq_get_state(dfc, freq);
- if (state == THERMAL_CSTATE_INVALID) {
- res = -EAGAIN;
- goto fail;
- }
+ mutex_lock(&df->lock);
+ res = df->profile->get_dev_status(df->dev.parent, &status);
+ mutex_unlock(&df->lock);
+ if (res)
+ return res;
+
+ freq = status.current_frequency;
- if (dfc->power_ops->get_real_power) {
+ /* Energy Model frequencies are in kHz */
+ em_perf_idx = freq_get_state(dfc, freq / 1000);
+ if (em_perf_idx == THERMAL_CSTATE_INVALID)
+ return -EAGAIN;
+
+ /*
+ * If a more sophisticated cooling device model was not provided by the
+ * driver, use simple Energy Model power calculation.
+ */
+ if (!dfc->power_ops || !dfc->power_ops->get_real_power) {
+ dfc_em_get_requested_power(dfc->em, &status, power,
+ em_perf_idx);
+ } else {
voltage = get_voltage(df, freq);
if (voltage == 0) {
- res = -EINVAL;
- goto fail;
+ dfc->res_util = SCALE_ERROR_MITIGATION;
+ return -EINVAL;
}
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 = dfc->em->table[em_perf_idx].power;
dfc->res_util *= SCALE_ERROR_MITIGATION;
if (*power > 1)
dfc->res_util /= *power;
} else {
- goto fail;
+ /* It is safe to set max in this case */
+ dfc->res_util = SCALE_ERROR_MITIGATION;
+ return res;
}
- } 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);
+ trace_thermal_power_devfreq_get_power(cdev, &status, freq, *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,
@@ -337,16 +316,14 @@ static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev,
u32 *power)
{
struct devfreq_cooling_device *dfc = cdev->devdata;
- unsigned long freq;
- u32 static_power;
+ int idx;
- if (state >= dfc->freq_table_size)
+ if (state > dfc->max_level)
return -EINVAL;
- freq = dfc->freq_table[state];
- static_power = get_static_power(dfc, freq);
+ idx = dfc->max_level - state;
+ *power = dfc->em->table[idx].power;
- *power = dfc->power_table[state] + static_power;
return 0;
}
@@ -359,36 +336,34 @@ static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev,
struct devfreq_dev_status *status = &df->last_status;
unsigned long freq = status->current_frequency;
unsigned long busy_time;
- s32 dyn_power;
- u32 static_power;
- s32 est_power;
+ u64 est_power;
int i;
- 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;
-
- /* Scale dynamic power for utilization */
+ /*
+ * Scale for resource utilization. Use simple Energy Model power
+ * calculation if a more sophisticated cooling device model does
+ * not exist.
+ */
+ if (!dfc->power_ops || !dfc->power_ops->get_real_power) {
busy_time = status->busy_time ?: 1;
- est_power = (dyn_power * status->total_time) / busy_time;
+
+ est_power = power * status->total_time;
+ est_power = do_div(est_power, busy_time);
+ } else {
+ est_power = power * dfc->res_util;
+ est_power = do_div(est_power, SCALE_ERROR_MITIGATION);
}
/*
* Find the first cooling state that is within the power
- * budget for dynamic power.
+ * budget. The EM power table is sorted ascending.
*/
- for (i = 0; i < dfc->freq_table_size - 1; i++)
- if (est_power >= dfc->power_table[i])
+ for (i = dfc->max_level; i > 0; i--)
+ if (est_power >= dfc->em->table[i].power)
break;
- *state = i;
- dfc->capped_state = i;
+ *state = dfc->max_level - i;
+
trace_thermal_power_devfreq_limit(cdev, freq, *state, power);
return 0;
}
@@ -400,91 +375,43 @@ static struct thermal_cooling_device_ops devfreq_cooling_ops = {
};
/**
- * devfreq_cooling_gen_tables() - Generate power and freq tables.
- * @dfc: Pointer to devfreq cooling device.
- *
- * Generate power and frequency tables: the power table hold the
- * device's maximum power usage at each cooling state (OPP). The
- * static and dynamic power using the appropriate voltage and
- * frequency for the state, is acquired from the struct
- * devfreq_cooling_power, and summed to make the maximum power draw.
- *
- * The frequency table holds the frequencies in descending order.
- * That way its indexed by cooling device state.
+ * devfreq_cooling_gen_tables() - Generate frequency table.
+ * @dfc: Pointer to devfreq cooling device.
+ * @num_opps: Number of OPPs
*
- * The tables are malloced, and pointers put in dfc. They must be
- * freed when unregistering the devfreq cooling device.
+ * Generate frequency table which holds the frequencies in descending
+ * order. That way its indexed by cooling device state. This is for
+ * compatibility with drivers which do not register Energy Model.
*
* Return: 0 on success, negative error code on failure.
*/
-static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc)
+static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc,
+ int num_opps)
{
struct devfreq *df = dfc->devfreq;
struct device *dev = df->dev.parent;
- int ret, num_opps;
unsigned long freq;
- u32 *power_table = NULL;
- u32 *freq_table;
int i;
- num_opps = dev_pm_opp_get_opp_count(dev);
-
- if (dfc->power_ops) {
- power_table = kcalloc(num_opps, sizeof(*power_table),
- GFP_KERNEL);
- if (!power_table)
- return -ENOMEM;
- }
-
- freq_table = kcalloc(num_opps, sizeof(*freq_table),
+ dfc->freq_table = kcalloc(num_opps, sizeof(*dfc->freq_table),
GFP_KERNEL);
- if (!freq_table) {
- ret = -ENOMEM;
- goto free_power_table;
- }
+ if (!dfc->freq_table)
+ return -ENOMEM;
for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) {
- unsigned long power, voltage;
struct dev_pm_opp *opp;
opp = dev_pm_opp_find_freq_floor(dev, &freq);
if (IS_ERR(opp)) {
- ret = PTR_ERR(opp);
- goto free_tables;
+ kfree(dfc->freq_table);
+ return PTR_ERR(opp);
}
- voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */
dev_pm_opp_put(opp);
-
- if (dfc->power_ops) {
- 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, "Power table: %lu MHz @ %lu mV: %lu = %lu mW\n",
- freq / 1000000, voltage, power, power);
-
- power_table[i] = power;
- }
-
- freq_table[i] = freq;
+ dfc->freq_table[i] = freq;
}
- if (dfc->power_ops)
- dfc->power_table = power_table;
-
- dfc->freq_table = freq_table;
- dfc->freq_table_size = num_opps;
-
return 0;
-
-free_tables:
- kfree(freq_table);
-free_power_table:
- kfree(power_table);
-
- return ret;
}
/**
@@ -509,7 +436,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
struct thermal_cooling_device *cdev;
struct devfreq_cooling_device *dfc;
char dev_name[THERMAL_NAME_LENGTH];
- int err;
+ int err, num_opps;
dfc = kzalloc(sizeof(*dfc), GFP_KERNEL);
if (!dfc)
@@ -517,22 +444,38 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
dfc->devfreq = df;
- if (dfc_power) {
- dfc->power_ops = dfc_power;
-
+ dfc->em = em_get_pd(df->dev.parent);
+ if (dfc->em) {
devfreq_cooling_ops.get_requested_power =
devfreq_cooling_get_requested_power;
devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
devfreq_cooling_ops.power2state = devfreq_cooling_power2state;
+
+ dfc->power_ops = dfc_power;
+
+ num_opps = em_pd_nr_perf_states(dfc->em);
+ } else {
+ /* Backward compatibility for drivers which do not use IPA */
+ dev_dbg(df->dev.parent, "missing EM for cooling device\n");
+
+ num_opps = dev_pm_opp_get_opp_count(df->dev.parent);
+
+ err = devfreq_cooling_gen_tables(dfc, num_opps);
+ if (err)
+ goto free_dfc;
}
- err = devfreq_cooling_gen_tables(dfc);
- if (err)
+ if (num_opps <= 0) {
+ err = -EINVAL;
goto free_dfc;
+ }
+
+ /* max_level is an index, not a counter */
+ dfc->max_level = num_opps - 1;
err = ida_simple_get(&devfreq_ida, 0, 0, GFP_KERNEL);
if (err < 0)
- goto free_tables;
+ goto free_table;
dfc->id = err;
snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id);
@@ -553,8 +496,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
release_ida:
ida_simple_remove(&devfreq_ida, dfc->id);
-free_tables:
- kfree(dfc->power_table);
+free_table:
kfree(dfc->freq_table);
free_dfc:
kfree(dfc);
@@ -582,7 +524,24 @@ EXPORT_SYMBOL_GPL(of_devfreq_cooling_register);
*/
struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df)
{
- return of_devfreq_cooling_register(NULL, df);
+ struct thermal_cooling_device *dfc;
+ struct device_node *np = NULL;
+ struct device *dev;
+
+ if (IS_ERR_OR_NULL(df))
+ return ERR_PTR(-EINVAL);
+
+ dev = df->dev.parent;
+
+ if (dev && dev->of_node)
+ np = of_node_get(dev->of_node);
+
+ dfc = of_devfreq_cooling_register(np, df);
+
+ if (np)
+ of_node_put(np);
+
+ return dfc;
}
EXPORT_SYMBOL_GPL(devfreq_cooling_register);
@@ -594,14 +553,14 @@ void devfreq_cooling_unregister(struct thermal_cooling_device *cdev)
{
struct devfreq_cooling_device *dfc;
- if (!cdev)
+ if (IS_ERR_OR_NULL(cdev))
return;
dfc = cdev->devdata;
thermal_cooling_device_unregister(dfc->cdev);
ida_simple_remove(&devfreq_ida, dfc->id);
- kfree(dfc->power_table);
+
kfree(dfc->freq_table);
kfree(dfc);
@@ -23,17 +23,6 @@
/**
* struct devfreq_cooling_power - Devfreq cooling power ops
- * @get_static_power: Take voltage, in mV, and return the static power
- * in mW. If NULL, the static power is assumed
- * to be 0.
- * @get_dynamic_power: Take voltage, in mV, and frequency, in HZ, and
- * return the dynamic power draw in mW. If NULL,
- * a simple power model is used.
- * @dyn_power_coeff: Coefficient for the simple dynamic power model in
- * mW/(MHz mV mV).
- * 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
@@ -53,14 +42,8 @@
* max total (static + dynamic) power value for each OPP.
*/
struct devfreq_cooling_power {
- unsigned long (*get_static_power)(struct devfreq *devfreq,
- unsigned long voltage);
- 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;
};
#ifdef CONFIG_DEVFREQ_THERMAL
@@ -153,31 +153,30 @@ TRACE_EVENT(thermal_power_cpu_limit,
TRACE_EVENT(thermal_power_devfreq_get_power,
TP_PROTO(struct thermal_cooling_device *cdev,
struct devfreq_dev_status *status, unsigned long freq,
- u32 dynamic_power, u32 static_power, u32 power),
+ u32 power),
- TP_ARGS(cdev, status, freq, dynamic_power, static_power, power),
+ TP_ARGS(cdev, status, freq, power),
TP_STRUCT__entry(
__string(type, cdev->type )
__field(unsigned long, freq )
- __field(u32, load )
- __field(u32, dynamic_power )
- __field(u32, static_power )
+ __field(u32, busy_time)
+ __field(u32, total_time)
__field(u32, power)
),
TP_fast_assign(
__assign_str(type, cdev->type);
__entry->freq = freq;
- __entry->load = (100 * status->busy_time) / status->total_time;
- __entry->dynamic_power = dynamic_power;
- __entry->static_power = static_power;
+ __entry->busy_time = status->busy_time;
+ __entry->total_time = status->total_time;
__entry->power = power;
),
- TP_printk("type=%s freq=%lu load=%u dynamic_power=%u static_power=%u power=%u",
+ TP_printk("type=%s freq=%lu load=%u power=%u",
__get_str(type), __entry->freq,
- __entry->load, __entry->dynamic_power, __entry->static_power,
+ __entry->total_time == 0 ? 0 :
+ (100 * __entry->busy_time) / __entry->total_time,
__entry->power)
);