};
static int __maybe_unused
-mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *mW,
+mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *uW,
unsigned long *KHz)
{
struct mtk_cpufreq_data *data;
i--;
*KHz = data->table[i].frequency;
- *mW = readl_relaxed(data->reg_bases[REG_EM_POWER_TBL] +
- i * LUT_ROW_SIZE) / 1000;
+ /* Provide micro-Watts value to the Energy Model */
+ *uW = readl_relaxed(data->reg_bases[REG_EM_POWER_TBL] +
+ i * LUT_ROW_SIZE);
return 0;
}
#include <linux/slab.h>
#include <linux/scmi_protocol.h>
#include <linux/types.h>
+#include <linux/units.h>
struct scmi_data {
int domain_id;
scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
unsigned long *KHz)
{
+ bool power_scale_mw = perf_ops->power_scale_mw_get(ph);
unsigned long Hz;
int ret, domain;
if (ret)
return ret;
+ /* Provide bigger resolution power to the Energy Model */
+ if (power_scale_mw)
+ *power *= MICROWATT_PER_MILLIWATT;
+
/* The EM framework specifies the frequency in KHz. */
*KHz = Hz / 1000;
* It provides the power used by @dev at @kHz if it is the frequency of an
* existing OPP, or at the frequency of the first OPP above @kHz otherwise
* (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
- * frequency and @mW to the associated power.
+ * frequency and @uW to the associated power.
*
* Returns 0 on success or a proper -EINVAL value in case of error.
*/
static int __maybe_unused
-_get_dt_power(struct device *dev, unsigned long *mW, unsigned long *kHz)
+_get_dt_power(struct device *dev, unsigned long *uW, unsigned long *kHz)
{
struct dev_pm_opp *opp;
unsigned long opp_freq, opp_power;
return -EINVAL;
*kHz = opp_freq / 1000;
- *mW = opp_power / 1000;
+ *uW = opp_power;
return 0;
}
* This computes the power estimated by @dev at @kHz if it is the frequency
* of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
* (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
- * frequency and @mW to the associated power. The power is estimated as
+ * frequency and @uW to the associated power. The power is estimated as
* P = C * V^2 * f with C being the device's capacitance and V and f
* respectively the voltage and frequency of the OPP.
*
* Returns -EINVAL if the power calculation failed because of missing
* parameters, 0 otherwise.
*/
-static int __maybe_unused _get_power(struct device *dev, unsigned long *mW,
+static int __maybe_unused _get_power(struct device *dev, unsigned long *uW,
unsigned long *kHz)
{
struct dev_pm_opp *opp;
return -EINVAL;
tmp = (u64)cap * mV * mV * (Hz / 1000000);
- do_div(tmp, 1000000000);
+ /* Provide power in micro-Watts */
+ do_div(tmp, 1000000);
- *mW = (unsigned long)tmp;
+ *uW = (unsigned long)tmp;
*kHz = Hz / 1000;
return 0;
for (i = 0; i < pd->nr_perf_states; i++) {
- power = pd->table[i].power * MICROWATT_PER_MILLIWATT * nr_cpus;
+ power = pd->table[i].power * nr_cpus;
if (power > power_limit)
break;
freq_qos_update_request(&dtpm_cpu->qos_req, freq);
- power_limit = pd->table[i - 1].power *
- MICROWATT_PER_MILLIWATT * nr_cpus;
+ power_limit = pd->table[i - 1].power * nr_cpus;
return power_limit;
}
#include <linux/pm_qos.h>
#include <linux/slab.h>
#include <linux/thermal.h>
+#include <linux/units.h>
#include <trace/events/thermal.h>
static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev,
u32 freq)
{
+ unsigned long power_mw;
int i;
for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) {
break;
}
- return cpufreq_cdev->em->table[i + 1].power;
+ power_mw = cpufreq_cdev->em->table[i + 1].power;
+ power_mw /= MICROWATT_PER_MILLIWATT;
+
+ return power_mw;
}
static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev,
u32 power)
{
+ unsigned long em_power_mw;
int i;
for (i = cpufreq_cdev->max_level; i > 0; i--) {
- if (power >= cpufreq_cdev->em->table[i].power)
+ /* Convert EM power to milli-Watts to make safe comparison */
+ em_power_mw = cpufreq_cdev->em->table[i].power;
+ em_power_mw /= MICROWATT_PER_MILLIWATT;
+ if (power >= em_power_mw)
break;
}
res = dfc->power_ops->get_real_power(df, power, freq, voltage);
if (!res) {
state = dfc->capped_state;
+
+ /* Convert EM power into milli-Watts first */
dfc->res_util = dfc->em_pd->table[state].power;
+ dfc->res_util /= MICROWATT_PER_MILLIWATT;
+
dfc->res_util *= SCALE_ERROR_MITIGATION;
if (*power > 1)
_normalize_load(&status);
- /* Scale power for utilization */
+ /* Convert EM power into milli-Watts first */
*power = dfc->em_pd->table[perf_idx].power;
+ *power /= MICROWATT_PER_MILLIWATT;
+ /* Scale power for utilization */
*power *= status.busy_time;
*power >>= 10;
}
perf_idx = dfc->max_state - state;
*power = dfc->em_pd->table[perf_idx].power;
+ *power /= MICROWATT_PER_MILLIWATT;
return 0;
}
struct devfreq_cooling_device *dfc = cdev->devdata;
struct devfreq *df = dfc->devfreq;
struct devfreq_dev_status status;
- unsigned long freq;
+ unsigned long freq, em_power_mw;
s32 est_power;
int i;
* Find the first cooling state that is within the power
* budget. The EM power table is sorted ascending.
*/
- for (i = dfc->max_state; i > 0; i--)
- if (est_power >= dfc->em_pd->table[i].power)
+ for (i = dfc->max_state; i > 0; i--) {
+ /* Convert EM power to milli-Watts to make safe comparison */
+ em_power_mw = dfc->em_pd->table[i].power;
+ em_power_mw /= MICROWATT_PER_MILLIWATT;
+ if (est_power >= em_power_mw)
break;
+ }
*state = dfc->max_state - i;
dfc->capped_state = *state;
/*
* em_perf_domain flags:
*
- * EM_PERF_DOMAIN_MILLIWATTS: The power values are in milli-Watts or some
+ * EM_PERF_DOMAIN_MICROWATTS: The power values are in micro-Watts or some
* other scale.
*
* EM_PERF_DOMAIN_SKIP_INEFFICIENCIES: Skip inefficient states when estimating
* EM_PERF_DOMAIN_ARTIFICIAL: The power values are artificial and might be
* created by platform missing real power information
*/
-#define EM_PERF_DOMAIN_MILLIWATTS BIT(0)
+#define EM_PERF_DOMAIN_MICROWATTS BIT(0)
#define EM_PERF_DOMAIN_SKIP_INEFFICIENCIES BIT(1)
#define EM_PERF_DOMAIN_ARTIFICIAL BIT(2)
#define em_is_artificial(em) ((em)->flags & EM_PERF_DOMAIN_ARTIFICIAL)
#ifdef CONFIG_ENERGY_MODEL
-#define EM_MAX_POWER 0xFFFF
+/*
+ * The max power value in micro-Watts. The limit of 64 Watts is set as
+ * a safety net to not overflow multiplications on 32bit platforms. The
+ * 32bit value limit for total Perf Domain power implies a limit of
+ * maximum CPUs in such domain to 64.
+ */
+#define EM_MAX_POWER (64000000) /* 64 Watts */
+
+/*
+ * To avoid possible energy estimation overflow on 32bit machines add
+ * limits to number of CPUs in the Perf. Domain.
+ * We are safe on 64bit machine, thus some big number.
+ */
+#ifdef CONFIG_64BIT
+#define EM_MAX_NUM_CPUS 4096
+#else
+#define EM_MAX_NUM_CPUS 16
+#endif
/*
- * Increase resolution of energy estimation calculations for 64-bit
- * architectures. The extra resolution improves decision made by EAS for the
- * task placement when two Performance Domains might provide similar energy
- * estimation values (w/o better resolution the values could be equal).
+ * To avoid an overflow on 32bit machines while calculating the energy
+ * use a different order in the operation. First divide by the 'cpu_scale'
+ * which would reduce big value stored in the 'cost' field, then multiply by
+ * the 'sum_util'. This would allow to handle existing platforms, which have
+ * e.g. power ~1.3 Watt at max freq, so the 'cost' value > 1mln micro-Watts.
+ * In such scenario, where there are 4 CPUs in the Perf. Domain the 'sum_util'
+ * could be 4096, then multiplication: 'cost' * 'sum_util' would overflow.
+ * This reordering of operations has some limitations, we lose small
+ * precision in the estimation (comparing to 64bit platform w/o reordering).
*
- * We increase resolution only if we have enough bits to allow this increased
- * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
- * are pretty high and the returns do not justify the increased costs.
+ * We are safe on 64bit machine.
*/
#ifdef CONFIG_64BIT
-#define em_scale_power(p) ((p) * 1000)
+#define em_estimate_energy(cost, sum_util, scale_cpu) \
+ (((cost) * (sum_util)) / (scale_cpu))
#else
-#define em_scale_power(p) (p)
+#define em_estimate_energy(cost, sum_util, scale_cpu) \
+ (((cost) / (scale_cpu)) * (sum_util))
#endif
struct em_data_callback {
* and frequency.
*
* In case of CPUs, the power is the one of a single CPU in the domain,
- * expressed in milli-Watts or an abstract scale. It is expected to
+ * expressed in micro-Watts or an abstract scale. It is expected to
* fit in the [0, EM_MAX_POWER] range.
*
* Return 0 on success.
struct em_perf_domain *em_pd_get(struct device *dev);
int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
struct em_data_callback *cb, cpumask_t *span,
- bool milliwatts);
+ bool microwatts);
void em_dev_unregister_perf_domain(struct device *dev);
/**
* pd_nrg = ------------------------ (4)
* scale_cpu
*/
- return ps->cost * sum_util / scale_cpu;
+ return em_estimate_energy(ps->cost, sum_util, scale_cpu);
}
/**
static inline
int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
struct em_data_callback *cb, cpumask_t *span,
- bool milliwatts)
+ bool microwatts)
{
return -EINVAL;
}
/*
* The power returned by active_state() is expected to be
- * positive and to fit into 16 bits.
+ * positive and be in range.
*/
if (!power || power > EM_MAX_POWER) {
dev_err(dev, "EM: invalid power: %lu\n",
goto free_ps_table;
}
} else {
- power_res = em_scale_power(table[i].power);
+ power_res = table[i].power;
cost = div64_u64(fmax * power_res, table[i].frequency);
}
{
struct em_perf_domain *pd;
struct device *cpu_dev;
- int cpu, ret;
+ int cpu, ret, num_cpus;
if (_is_cpu_device(dev)) {
+ num_cpus = cpumask_weight(cpus);
+
+ /* Prevent max possible energy calculation to not overflow */
+ if (num_cpus > EM_MAX_NUM_CPUS) {
+ dev_err(dev, "EM: too many CPUs, overflow possible\n");
+ return -EINVAL;
+ }
+
pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL);
if (!pd)
return -ENOMEM;
* @cpus : Pointer to cpumask_t, which in case of a CPU device is
* obligatory. It can be taken from i.e. 'policy->cpus'. For other
* type of devices this should be set to NULL.
- * @milliwatts : Flag indicating that the power values are in milliWatts or
+ * @microwatts : Flag indicating that the power values are in micro-Watts or
* in some other scale. It must be set properly.
*
* Create Energy Model tables for a performance domain using the callbacks
* defined in cb.
*
- * The @milliwatts is important to set with correct value. Some kernel
+ * The @microwatts is important to set with correct value. Some kernel
* sub-systems might rely on this flag and check if all devices in the EM are
* using the same scale.
*
*/
int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
struct em_data_callback *cb, cpumask_t *cpus,
- bool milliwatts)
+ bool microwatts)
{
unsigned long cap, prev_cap = 0;
unsigned long flags = 0;
}
}
- if (milliwatts)
- flags |= EM_PERF_DOMAIN_MILLIWATTS;
+ if (microwatts)
+ flags |= EM_PERF_DOMAIN_MICROWATTS;
else if (cb->get_cost)
flags |= EM_PERF_DOMAIN_ARTIFICIAL;
projects / linux.git / commitdiff