The Energy Model uses concept of performance domain and capacity states in order to calculate power used by CPUs. Change naming convention from capacity to performance state would enable wider usage in future, e.g. upcoming support for other devices other than CPUs.

Acked-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- drivers/thermal/cpufreq_cooling.c | 12 ++--- include/linux/energy_model.h | 86 +++++++++++++++++-------------- kernel/power/energy_model.c | 44 ++++++++-------- kernel/sched/topology.c | 20 +++---- 4 files changed, 84 insertions(+), 78 deletions(-)

diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c index e297e135c031..ad8971e26538 100644 --- a/drivers/thermal/cpufreq_cooling.c +++ b/drivers/thermal/cpufreq_cooling.c @@ -333,18 +333,18 @@ static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev, return false;

policy = cpufreq_cdev->policy; - if (!cpumask_equal(policy->related_cpus, to_cpumask(em->cpus))) { + if (!cpumask_equal(policy->related_cpus, em_span_cpus(em))) { pr_err("The span of pd %*pbl is misaligned with cpufreq policy %*pbl\n", - cpumask_pr_args(to_cpumask(em->cpus)), + cpumask_pr_args(em_span_cpus(em)), cpumask_pr_args(policy->related_cpus)); return false; }

nr_levels = cpufreq_cdev->max_level + 1; - if (em->nr_cap_states != nr_levels) { - pr_err("The number of cap states in pd %*pbl (%u) doesn't match the number of cooling levels (%u)\n", - cpumask_pr_args(to_cpumask(em->cpus)), - em->nr_cap_states, nr_levels); + if (em_pd_nr_perf_states(em) != nr_levels) { + pr_err("The number of performance states in pd %*pbl (%u) doesn't match the number of cooling levels (%u)\n", + cpumask_pr_args(em_span_cpus(em)), + em_pd_nr_perf_states(em), nr_levels); return false; }

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index ade6486a3382..fe336a9eb5d4 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -10,13 +10,13 @@ #include <linux/types.h>

/** - * em_cap_state - Capacity state of a performance domain + * em_perf_state - Performance state of a performance domain * @frequency: The CPU frequency in KHz, for consistency with CPUFreq * @power: The power consumed by 1 CPU at this level, in milli-watts * @cost: The cost coefficient associated with this level, used during * energy calculation. Equal to: power * max_frequency / frequency */ -struct em_cap_state { +struct em_perf_state { unsigned long frequency; unsigned long power; unsigned long cost; @@ -24,8 +24,8 @@ struct em_cap_state {

/** * em_perf_domain - Performance domain - * @table: List of capacity states, in ascending order - * @nr_cap_states: Number of capacity states + * @table: List of performance states, in ascending order + * @nr_perf_states: Number of performance states * @cpus: Cpumask covering the CPUs of the domain * * A "performance domain" represents a group of CPUs whose performance is @@ -34,22 +34,27 @@ struct em_cap_state { * CPUFreq policies. */ struct em_perf_domain { - struct em_cap_state *table; - int nr_cap_states; + struct em_perf_state *table; + int nr_perf_states; unsigned long cpus[]; };

+#define em_span_cpus(em) (to_cpumask((em)->cpus)) + #ifdef CONFIG_ENERGY_MODEL #define EM_CPU_MAX_POWER 0xFFFF

struct em_data_callback { /** - * active_power() - Provide power at the next capacity state of a CPU - * @power : Active power at the capacity state in mW (modified) - * @freq : Frequency at the capacity state in kHz (modified) + * active_power() - Provide power at the next performance state of + * a CPU + * @power : Active power at the performance state in mW + * (modified) + * @freq : Frequency at the performance state in kHz + * (modified) * @cpu : CPU for which we do this operation * - * active_power() must find the lowest capacity state of 'cpu' above + * active_power() must find the lowest performance state of 'cpu' above * 'freq' and update 'power' and 'freq' to the matching active power * and frequency. * @@ -80,46 +85,46 @@ static inline unsigned long em_pd_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util) { unsigned long freq, scale_cpu; - struct em_cap_state *cs; + struct em_perf_state *ps; int i, cpu;

/* - * In order to predict the capacity state, map the utilization of the - * most utilized CPU of the performance domain to a requested frequency, - * like schedutil. + * In order to predict the performance state, map the utilization of + * the most utilized CPU of the performance domain to a requested + * frequency, like schedutil. */ cpu = cpumask_first(to_cpumask(pd->cpus)); scale_cpu = arch_scale_cpu_capacity(cpu); - cs = &pd->table[pd->nr_cap_states - 1]; - freq = map_util_freq(max_util, cs->frequency, scale_cpu); + ps = &pd->table[pd->nr_perf_states - 1]; + freq = map_util_freq(max_util, ps->frequency, scale_cpu);

/* - * Find the lowest capacity state of the Energy Model above the + * Find the lowest performance state of the Energy Model above the * requested frequency. */ - for (i = 0; i < pd->nr_cap_states; i++) { - cs = &pd->table[i]; - if (cs->frequency >= freq) + for (i = 0; i < pd->nr_perf_states; i++) { + ps = &pd->table[i]; + if (ps->frequency >= freq) break; }

/* - * The capacity of a CPU in the domain at that capacity state (cs) + * The capacity of a CPU in the domain at the performance state (ps) * can be computed as: * - * cs->freq * scale_cpu - * cs->cap = -------------------- (1) + * ps->freq * scale_cpu + * ps->cap = -------------------- (1) * cpu_max_freq * * So, ignoring the costs of idle states (which are not available in - * the EM), the energy consumed by this CPU at that capacity state is - * estimated as: + * the EM), the energy consumed by this CPU at that performance state + * is estimated as: * - * cs->power * cpu_util + * ps->power * cpu_util * cpu_nrg = -------------------- (2) - * cs->cap + * ps->cap * - * since 'cpu_util / cs->cap' represents its percentage of busy time. + * since 'cpu_util / ps->cap' represents its percentage of busy time. * * NOTE: Although the result of this computation actually is in * units of power, it can be manipulated as an energy value @@ -129,34 +134,35 @@ static inline unsigned long em_pd_energy(struct em_perf_domain *pd, * By injecting (1) in (2), 'cpu_nrg' can be re-expressed as a product * of two terms: * - * cs->power * cpu_max_freq cpu_util + * ps->power * cpu_max_freq cpu_util * cpu_nrg = ------------------------ * --------- (3) - * cs->freq scale_cpu + * ps->freq scale_cpu * - * The first term is static, and is stored in the em_cap_state struct - * as 'cs->cost'. + * The first term is static, and is stored in the em_perf_state struct + * as 'ps->cost'. * * Since all CPUs of the domain have the same micro-architecture, they - * share the same 'cs->cost', and the same CPU capacity. Hence, the + * share the same 'ps->cost', and the same CPU capacity. Hence, the * total energy of the domain (which is the simple sum of the energy of * all of its CPUs) can be factorized as: * - * cs->cost * \Sum cpu_util + * ps->cost * \Sum cpu_util * pd_nrg = ------------------------ (4) * scale_cpu */ - return cs->cost * sum_util / scale_cpu; + return ps->cost * sum_util / scale_cpu; }

/** - * em_pd_nr_cap_states() - Get the number of capacity states of a perf. domain + * em_pd_nr_perf_states() - Get the number of performance states of a perf. + * domain * @pd : performance domain for which this must be done * - * Return: the number of capacity states in the performance domain table + * Return: the number of performance states in the performance domain table */ -static inline int em_pd_nr_cap_states(struct em_perf_domain *pd) +static inline int em_pd_nr_perf_states(struct em_perf_domain *pd) { - return pd->nr_cap_states; + return pd->nr_perf_states; }

#else @@ -177,7 +183,7 @@ static inline unsigned long em_pd_energy(struct em_perf_domain *pd, { return 0; } -static inline int em_pd_nr_cap_states(struct em_perf_domain *pd) +static inline int em_pd_nr_perf_states(struct em_perf_domain *pd) { return 0; } diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 0a9326f5f421..9892d548a0fa 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -27,18 +27,18 @@ static DEFINE_MUTEX(em_pd_mutex); #ifdef CONFIG_DEBUG_FS static struct dentry *rootdir;

-static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd) +static void em_debug_create_ps(struct em_perf_state *ps, struct dentry *pd) { struct dentry *d; char name[24];

- snprintf(name, sizeof(name), "cs:%lu", cs->frequency); + snprintf(name, sizeof(name), "ps:%lu", ps->frequency);

- /* Create per-cs directory */ + /* Create per-ps directory */ d = debugfs_create_dir(name, pd); - debugfs_create_ulong("frequency", 0444, d, &cs->frequency); - debugfs_create_ulong("power", 0444, d, &cs->power); - debugfs_create_ulong("cost", 0444, d, &cs->cost); + debugfs_create_ulong("frequency", 0444, d, &ps->frequency); + debugfs_create_ulong("power", 0444, d, &ps->power); + debugfs_create_ulong("cost", 0444, d, &ps->cost); }

static int em_debug_cpus_show(struct seq_file *s, void *unused) @@ -62,9 +62,9 @@ static void em_debug_create_pd(struct em_perf_domain *pd, int cpu)

debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops);

- /* Create a sub-directory for each capacity state */ - for (i = 0; i < pd->nr_cap_states; i++) - em_debug_create_cs(&pd->table[i], d); + /* Create a sub-directory for each performance state */ + for (i = 0; i < pd->nr_perf_states; i++) + em_debug_create_ps(&pd->table[i], d); }

static int __init em_debug_init(void) @@ -84,7 +84,7 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, unsigned long opp_eff, prev_opp_eff = ULONG_MAX; unsigned long power, freq, prev_freq = 0; int i, ret, cpu = cpumask_first(span); - struct em_cap_state *table; + struct em_perf_state *table; struct em_perf_domain *pd; u64 fmax;

@@ -99,26 +99,26 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, if (!table) goto free_pd;

- /* Build the list of capacity states for this performance domain */ + /* Build the list of performance states for this performance domain */ for (i = 0, freq = 0; i < nr_states; i++, freq++) { /* * active_power() is a driver callback which ceils 'freq' to - * lowest capacity state of 'cpu' above 'freq' and updates + * lowest performance state of 'cpu' above 'freq' and updates * 'power' and 'freq' accordingly. */ ret = cb->active_power(&power, &freq, cpu); if (ret) { - pr_err("pd%d: invalid cap. state: %d\n", cpu, ret); - goto free_cs_table; + pr_err("pd%d: invalid perf. state: %d\n", cpu, ret); + goto free_ps_table; }

/* * We expect the driver callback to increase the frequency for - * higher capacity states. + * higher performance states. */ if (freq <= prev_freq) { pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq); - goto free_cs_table; + goto free_ps_table; }

/* @@ -127,7 +127,7 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, */ if (!power || power > EM_CPU_MAX_POWER) { pr_err("pd%d: invalid power: %lu\n", cpu, power); - goto free_cs_table; + goto free_ps_table; }

table[i].power = power; @@ -141,12 +141,12 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, */ opp_eff = freq / power; if (opp_eff >= prev_opp_eff) - pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_cap_state %d >= em_cap_state%d\n", + pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", cpu, i, i - 1); prev_opp_eff = opp_eff; }

- /* Compute the cost of each capacity_state. */ + /* Compute the cost of each performance state. */ fmax = (u64) table[nr_states - 1].frequency; for (i = 0; i < nr_states; i++) { table[i].cost = div64_u64(fmax * table[i].power, @@ -154,14 +154,14 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, }

pd->table = table; - pd->nr_cap_states = nr_states; + pd->nr_perf_states = nr_states; cpumask_copy(to_cpumask(pd->cpus), span);

em_debug_create_pd(pd, cpu);

return pd;

-free_cs_table: +free_ps_table: kfree(table); free_pd: kfree(pd); @@ -185,7 +185,7 @@ EXPORT_SYMBOL_GPL(em_cpu_get); /** * em_register_perf_domain() - Register the Energy Model of a performance domain * @span : Mask of CPUs in the performance domain - * @nr_states : Number of capacity states to register + * @nr_states : Number of performance states to register * @cb : Callback functions providing the data of the Energy Model * * Create Energy Model tables for a performance domain using the callbacks diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index ba81187bb7af..2f91d3126365 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -272,10 +272,10 @@ static void perf_domain_debug(const struct cpumask *cpu_map, printk(KERN_DEBUG "root_domain %*pbl:", cpumask_pr_args(cpu_map));

while (pd) { - printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_cstate=%d }", + printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_pstate=%d }", cpumask_first(perf_domain_span(pd)), cpumask_pr_args(perf_domain_span(pd)), - em_pd_nr_cap_states(pd->em_pd)); + em_pd_nr_perf_states(pd->em_pd)); pd = pd->next; }

@@ -313,26 +313,26 @@ static void sched_energy_set(bool has_eas) * * The complexity of the Energy Model is defined as: * - * C = nr_pd * (nr_cpus + nr_cs) + * C = nr_pd * (nr_cpus + nr_ps) * * with parameters defined as: * - nr_pd: the number of performance domains * - nr_cpus: the number of CPUs - * - nr_cs: the sum of the number of capacity states of all performance + * - nr_ps: the sum of the number of performance states of all performance * domains (for example, on a system with 2 performance domains, - * with 10 capacity states each, nr_cs = 2 * 10 = 20). + * with 10 performance states each, nr_ps = 2 * 10 = 20). * * It is generally not a good idea to use such a model in the wake-up path on * very complex platforms because of the associated scheduling overheads. The * arbitrary constraint below prevents that. It makes EAS usable up to 16 CPUs - * with per-CPU DVFS and less than 8 capacity states each, for example. + * with per-CPU DVFS and less than 8 performance states each, for example. */ #define EM_MAX_COMPLEXITY 2048

extern struct cpufreq_governor schedutil_gov; static bool build_perf_domains(const struct cpumask *cpu_map) { - int i, nr_pd = 0, nr_cs = 0, nr_cpus = cpumask_weight(cpu_map); + int i, nr_pd = 0, nr_ps = 0, nr_cpus = cpumask_weight(cpu_map); struct perf_domain *pd = NULL, *tmp; int cpu = cpumask_first(cpu_map); struct root_domain *rd = cpu_rq(cpu)->rd; @@ -384,15 +384,15 @@ static bool build_perf_domains(const struct cpumask *cpu_map) pd = tmp;

/* - * Count performance domains and capacity states for the + * Count performance domains and performance states for the * complexity check. */ nr_pd++; - nr_cs += em_pd_nr_cap_states(pd->em_pd); + nr_ps += em_pd_nr_perf_states(pd->em_pd); }

/* Bail out if the Energy Model complexity is too high. */ - if (nr_pd * (nr_cs + nr_cpus) > EM_MAX_COMPLEXITY) { + if (nr_pd * (nr_ps + nr_cpus) > EM_MAX_COMPLEXITY) { WARN(1, "rd %*pbl: Failed to start EAS, EM complexity is too high\n", cpumask_pr_args(cpu_map)); goto free;

Add now function in the Energy Model framework which is going to support new devices. This function will help in transition and make it smoother. For now it still checks if the cpumask is a valid pointer, which will be removed later when the new structures and infrastructure will be ready.

Acked-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- include/linux/energy_model.h | 13 ++++++++++-- kernel/power/energy_model.c | 40 ++++++++++++++++++++++++++++++------ 2 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index fe336a9eb5d4..7c048df98447 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -2,6 +2,7 @@ #ifndef _LINUX_ENERGY_MODEL_H #define _LINUX_ENERGY_MODEL_H #include <linux/cpumask.h> +#include <linux/device.h> #include <linux/jump_label.h> #include <linux/kobject.h> #include <linux/rcupdate.h> @@ -42,7 +43,7 @@ struct em_perf_domain { #define em_span_cpus(em) (to_cpumask((em)->cpus))

#ifdef CONFIG_ENERGY_MODEL -#define EM_CPU_MAX_POWER 0xFFFF +#define EM_MAX_POWER 0xFFFF

struct em_data_callback { /** @@ -59,7 +60,7 @@ struct em_data_callback { * and frequency. * * The power is the one of a single CPU in the domain, expressed in - * milli-watts. It is expected to fit in the [0, EM_CPU_MAX_POWER] + * milli-watts. It is expected to fit in the [0, EM_MAX_POWER] * range. * * Return 0 on success. @@ -71,6 +72,8 @@ struct em_data_callback { struct em_perf_domain *em_cpu_get(int cpu); int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, struct em_data_callback *cb); +int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, + struct em_data_callback *cb, cpumask_t *span);

/** * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain @@ -174,6 +177,12 @@ static inline int em_register_perf_domain(cpumask_t *span, { return -EINVAL; } +static inline +int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, + struct em_data_callback *cb, cpumask_t *span) +{ + return -EINVAL; +} static inline struct em_perf_domain *em_cpu_get(int cpu) { return NULL; diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 9892d548a0fa..875b163e54ab 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -125,7 +125,7 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, * The power returned by active_state() is expected to be * positive, in milli-watts and to fit into 16 bits. */ - if (!power || power > EM_CPU_MAX_POWER) { + if (!power || power > EM_MAX_POWER) { pr_err("pd%d: invalid power: %lu\n", cpu, power); goto free_ps_table; } @@ -183,10 +183,13 @@ struct em_perf_domain *em_cpu_get(int cpu) EXPORT_SYMBOL_GPL(em_cpu_get);

/** - * em_register_perf_domain() - Register the Energy Model of a performance domain - * @span : Mask of CPUs in the performance domain + * em_dev_register_perf_domain() - Register the Energy Model (EM) for a device + * @dev : Device for which the EM is to register * @nr_states : Number of performance states to register * @cb : Callback functions providing the data of the Energy Model + * @span : 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. * * Create Energy Model tables for a performance domain using the callbacks * defined in cb. @@ -196,14 +199,14 @@ EXPORT_SYMBOL_GPL(em_cpu_get); * * Return 0 on success */ -int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, - struct em_data_callback *cb) +int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, + struct em_data_callback *cb, cpumask_t *span) { unsigned long cap, prev_cap = 0; struct em_perf_domain *pd; int cpu, ret = 0;

- if (!span || !nr_states || !cb) + if (!dev || !span || !nr_states || !cb) return -EINVAL;

/* @@ -255,4 +258,29 @@ int em_register_perf_domain(cpumask_t *span, unsigned int nr_states,

return ret; } +EXPORT_SYMBOL_GPL(em_dev_register_perf_domain); + +/** + * em_register_perf_domain() - Register the Energy Model of a performance domain + * @span : Mask of CPUs in the performance domain + * @nr_states : Number of capacity states to register + * @cb : Callback functions providing the data of the Energy Model + * + * Create Energy Model tables for a performance domain using the callbacks + * defined in cb. + * + * If multiple clients register the same performance domain, all but the first + * registration will be ignored. + * + * Return 0 on success + */ +int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, + struct em_data_callback *cb) +{ + struct device *cpu_dev; + + cpu_dev = get_cpu_device(cpumask_first(span)); + + return em_dev_register_perf_domain(cpu_dev, nr_states, cb, span); +} EXPORT_SYMBOL_GPL(em_register_perf_domain);

The Energy Model framework is going to support devices other that CPUs. In order to make this happen change the callback function and add pointer to a device as an argument.

Update the related users to use new function and new callback from the Energy Model.

Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- drivers/cpufreq/scmi-cpufreq.c | 11 +++-------- drivers/opp/of.c | 9 ++------- include/linux/energy_model.h | 15 ++++++++------- kernel/power/energy_model.c | 9 +++++---- 4 files changed, 18 insertions(+), 26 deletions(-)

diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c index 61623e2ff149..11ee24e06d12 100644 --- a/drivers/cpufreq/scmi-cpufreq.c +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -103,17 +103,12 @@ scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) }

static int __maybe_unused -scmi_get_cpu_power(unsigned long *power, unsigned long *KHz, int cpu) +scmi_get_cpu_power(unsigned long *power, unsigned long *KHz, + struct device *cpu_dev) { - struct device *cpu_dev = get_cpu_device(cpu); unsigned long Hz; int ret, domain;

- if (!cpu_dev) { - pr_err("failed to get cpu%d device\n", cpu); - return -ENODEV; - } - domain = handle->perf_ops->device_domain_id(cpu_dev); if (domain < 0) return domain; @@ -200,7 +195,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)

policy->fast_switch_possible = true;

- em_register_perf_domain(policy->cpus, nr_opp, &em_cb); + em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus);

return 0;

diff --git a/drivers/opp/of.c b/drivers/opp/of.c index 9cd8f0adacae..5b75829a915d 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -1047,9 +1047,8 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node); * calculation failed because of missing parameters, 0 otherwise. */ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz, - int cpu) + struct device *cpu_dev) { - struct device *cpu_dev; struct dev_pm_opp *opp; struct device_node *np; unsigned long mV, Hz; @@ -1057,10 +1056,6 @@ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz, u64 tmp; int ret;

- cpu_dev = get_cpu_device(cpu); - if (!cpu_dev) - return -ENODEV; - np = of_node_get(cpu_dev->of_node); if (!np) return -EINVAL; @@ -1128,6 +1123,6 @@ void dev_pm_opp_of_register_em(struct cpumask *cpus) if (ret || !cap) return;

- em_register_perf_domain(cpus, nr_opp, &em_cb); + em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, cpus); } EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em); diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index 7c048df98447..7076cb22b247 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -48,24 +48,25 @@ struct em_perf_domain { struct em_data_callback { /** * active_power() - Provide power at the next performance state of - * a CPU + * a device * @power : Active power at the performance state in mW * (modified) * @freq : Frequency at the performance state in kHz * (modified) - * @cpu : CPU for which we do this operation + * @dev : Device for which we do this operation (can be a CPU) * - * active_power() must find the lowest performance state of 'cpu' above + * active_power() must find the lowest performance state of 'dev' above * 'freq' and update 'power' and 'freq' to the matching active power * and frequency. * - * The power is the one of a single CPU in the domain, expressed in - * milli-watts. It is expected to fit in the [0, EM_MAX_POWER] - * range. + * In case of CPUs, the power is the one of a single CPU in the domain, + * expressed in milli-watts. It is expected to fit in the + * [0, EM_MAX_POWER] range. * * Return 0 on success. */ - int (*active_power)(unsigned long *power, unsigned long *freq, int cpu); + int (*active_power)(unsigned long *power, unsigned long *freq, + struct device *dev); }; #define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb }

diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 875b163e54ab..5b8a1566526a 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -78,8 +78,9 @@ core_initcall(em_debug_init); #else /* CONFIG_DEBUG_FS */ static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} #endif -static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, - struct em_data_callback *cb) +static struct em_perf_domain * +em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, + cpumask_t *span) { unsigned long opp_eff, prev_opp_eff = ULONG_MAX; unsigned long power, freq, prev_freq = 0; @@ -106,7 +107,7 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, * lowest performance state of 'cpu' above 'freq' and updates * 'power' and 'freq' accordingly. */ - ret = cb->active_power(&power, &freq, cpu); + ret = cb->active_power(&power, &freq, dev); if (ret) { pr_err("pd%d: invalid perf. state: %d\n", cpu, ret); goto free_ps_table; @@ -237,7 +238,7 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, }

/* Create the performance domain and add it to the Energy Model. */ - pd = em_create_pd(span, nr_states, cb); + pd = em_create_pd(dev, nr_states, cb, span); if (!pd) { ret = -EINVAL; goto unlock;

Remove old function em_register_perf_domain which is no longer needed. There is em_dev_register_perf_domain that covers old use cases and new as well.

Acked-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- include/linux/energy_model.h | 7 ------- kernel/power/energy_model.c | 25 ------------------------- 2 files changed, 32 deletions(-)

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index f5a88486d1c4..6b56ae6c6a89 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -77,8 +77,6 @@ struct em_data_callback {

struct em_perf_domain *em_cpu_get(int cpu); struct em_perf_domain *em_pd_get(struct device *dev); -int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, - struct em_data_callback *cb); int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, struct em_data_callback *cb, cpumask_t *span); void em_dev_unregister_perf_domain(struct device *dev); @@ -180,11 +178,6 @@ static inline int em_pd_nr_perf_states(struct em_perf_domain *pd) struct em_data_callback {}; #define EM_DATA_CB(_active_power_cb) { }

-static inline int em_register_perf_domain(cpumask_t *span, - unsigned int nr_states, struct em_data_callback *cb) -{ - return -EINVAL; -} static inline int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, struct em_data_callback *cb, cpumask_t *span) diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 9cc7f2973600..3c5c579ad2c2 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -322,31 +322,6 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, } EXPORT_SYMBOL_GPL(em_dev_register_perf_domain);

-/** - * em_register_perf_domain() - Register the Energy Model of a performance domain - * @span : Mask of CPUs in the performance domain - * @nr_states : Number of capacity states to register - * @cb : Callback functions providing the data of the Energy Model - * - * Create Energy Model tables for a performance domain using the callbacks - * defined in cb. - * - * If multiple clients register the same performance domain, all but the first - * registration will be ignored. - * - * Return 0 on success - */ -int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, - struct em_data_callback *cb) -{ - struct device *cpu_dev; - - cpu_dev = get_cpu_device(cpumask_first(span)); - - return em_dev_register_perf_domain(cpu_dev, nr_states, cb, span); -} -EXPORT_SYMBOL_GPL(em_register_perf_domain); - /** * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device * @dev : Device for which the EM is registered

Energy Model framework supports now other devices than CPUs. Refactor some of the functions in order to prevent wrong usage. The old function em_pd_energy has to generic name. It must not be used without proper cpumask pointer, which is possible only for CPU devices. Thus, rename it and add proper description to warn of potential wrong usage for other devices.

Acked-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- include/linux/energy_model.h | 11 ++++++++--- kernel/sched/fair.c | 2 +- 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index 6b56ae6c6a89..c92e3ee15245 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -82,15 +82,20 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, void em_dev_unregister_perf_domain(struct device *dev);

/** - * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain + * em_cpu_energy() - Estimates the energy consumed by the CPUs of a + performance domain * @pd : performance domain for which energy has to be estimated * @max_util : highest utilization among CPUs of the domain * @sum_util : sum of the utilization of all CPUs in the domain * + * This function must be used only for CPU devices. There is no validation, + * i.e. if the EM is a CPU type and has cpumask allocated. It is called from + * the scheduler code quite frequently and that is why there is not checks. + * * Return: the sum of the energy consumed by the CPUs of the domain assuming * a capacity state satisfying the max utilization of the domain. */ -static inline unsigned long em_pd_energy(struct em_perf_domain *pd, +static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util) { unsigned long freq, scale_cpu; @@ -195,7 +200,7 @@ static inline struct em_perf_domain *em_pd_get(struct device *dev) { return NULL; } -static inline unsigned long em_pd_energy(struct em_perf_domain *pd, +static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util) { return 0; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b3bb4d6e49c3..7700e97af52f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6468,7 +6468,7 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) max_util = max(max_util, cpu_util); }

- return em_pd_energy(pd->em_pd, max_util, sum_util); + return em_cpu_energy(pd->em_pd, max_util, sum_util); }

/*

The Energy Model framework supports also other devices than CPUs. Update related information and add description for the new usage.

Acked-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- Documentation/power/energy-model.rst | 135 +++++++++++++++------------ 1 file changed, 75 insertions(+), 60 deletions(-)

diff --git a/Documentation/power/energy-model.rst b/Documentation/power/energy-model.rst index 90a345d57ae9..a6fb986abe3c 100644 --- a/Documentation/power/energy-model.rst +++ b/Documentation/power/energy-model.rst @@ -1,15 +1,17 @@ -==================== -Energy Model of CPUs -==================== +.. SPDX-License-Identifier: GPL-2.0 + +======================= +Energy Model of devices +=======================

1. Overview -----------

The Energy Model (EM) framework serves as an interface between drivers knowing -the power consumed by CPUs at various performance levels, and the kernel +the power consumed by devices at various performance levels, and the kernel subsystems willing to use that information to make energy-aware decisions.

-The source of the information about the power consumed by CPUs can vary greatly +The source of the information about the power consumed by devices can vary greatly from one platform to another. These power costs can be estimated using devicetree data in some cases. In others, the firmware will know better. Alternatively, userspace might be best positioned. And so on. In order to avoid @@ -25,7 +27,7 @@ framework, and interested clients reading the data from it:: +---------------+ +-----------------+ +---------------+ | Thermal (IPA) | | Scheduler (EAS) | | Other | +---------------+ +-----------------+ +---------------+ - | | em_pd_energy() | + | | em_cpu_energy() | | | em_cpu_get() | +---------+ | +---------+ | | | @@ -35,7 +37,7 @@ framework, and interested clients reading the data from it:: | Framework | +---------------------+ ^ ^ ^ - | | | em_register_perf_domain() + | | | em_dev_register_perf_domain() +----------+ | +---------+ | | | +---------------+ +---------------+ +--------------+ @@ -47,12 +49,12 @@ framework, and interested clients reading the data from it:: | Device Tree | | Firmware | | ? | +--------------+ +---------------+ +--------------+

-The EM framework manages power cost tables per 'performance domain' in the -system. A performance domain is a group of CPUs whose performance is scaled -together. Performance domains generally have a 1-to-1 mapping with CPUFreq -policies. All CPUs in a performance domain are required to have the same -micro-architecture. CPUs in different performance domains can have different -micro-architectures. +In case of CPU devices the EM framework manages power cost tables per +'performance domain' in the system. A performance domain is a group of CPUs +whose performance is scaled together. Performance domains generally have a +1-to-1 mapping with CPUFreq policies. All CPUs in a performance domain are +required to have the same micro-architecture. CPUs in different performance +domains can have different micro-architectures.

2. Core APIs @@ -70,14 +72,16 @@ CONFIG_ENERGY_MODEL must be enabled to use the EM framework. Drivers are expected to register performance domains into the EM framework by calling the following API::

- int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, - struct em_data_callback *cb); + int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, + struct em_data_callback *cb, cpumask_t *cpus);

-Drivers must specify the CPUs of the performance domains using the cpumask -argument, and provide a callback function returning <frequency, power> tuples -for each capacity state. The callback function provided by the driver is free +Drivers must provide a callback function returning <frequency, power> tuples +for each performance state. The callback function provided by the driver is free to fetch data from any relevant location (DT, firmware, ...), and by any mean -deemed necessary. See Section 3. for an example of driver implementing this +deemed necessary. Only for CPU devices, drivers must specify the CPUs of the +performance domains using cpumask. For other devices than CPUs the last +argument must be set to NULL. +See Section 3. for an example of driver implementing this callback, and kernel/power/energy_model.c for further documentation on this API.

@@ -85,13 +89,20 @@ API. 2.3 Accessing performance domains ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+There are two API functions which provide the access to the energy model: +em_cpu_get() which takes CPU id as an argument and em_pd_get() with device +pointer as an argument. It depends on the subsystem which interface it is +going to use, but in case of CPU devices both functions return the same +performance domain. + Subsystems interested in the energy model of a CPU can retrieve it using the em_cpu_get() API. The energy model tables are allocated once upon creation of the performance domains, and kept in memory untouched.

The energy consumed by a performance domain can be estimated using the -em_pd_energy() API. The estimation is performed assuming that the schedutil -CPUfreq governor is in use. +em_cpu_energy() API. The estimation is performed assuming that the schedutil +CPUfreq governor is in use in case of CPU device. Currently this calculation is +not provided for other type of devices.

More details about the above APIs can be found in include/linux/energy_model.h.

@@ -106,42 +117,46 @@ EM framework::

-> drivers/cpufreq/foo_cpufreq.c

- 01 static int est_power(unsigned long *mW, unsigned long *KHz, int cpu) - 02 { - 03 long freq, power; - 04 - 05 /* Use the 'foo' protocol to ceil the frequency */ - 06 freq = foo_get_freq_ceil(cpu, *KHz); - 07 if (freq < 0); - 08 return freq; - 09 - 10 /* Estimate the power cost for the CPU at the relevant freq. */ - 11 power = foo_estimate_power(cpu, freq); - 12 if (power < 0); - 13 return power; - 14 - 15 /* Return the values to the EM framework */ - 16 *mW = power; - 17 *KHz = freq; - 18 - 19 return 0; - 20 } - 21 - 22 static int foo_cpufreq_init(struct cpufreq_policy *policy) - 23 { - 24 struct em_data_callback em_cb = EM_DATA_CB(est_power); - 25 int nr_opp, ret; - 26 - 27 /* Do the actual CPUFreq init work ... */ - 28 ret = do_foo_cpufreq_init(policy); - 29 if (ret) - 30 return ret; - 31 - 32 /* Find the number of OPPs for this policy */ - 33 nr_opp = foo_get_nr_opp(policy); - 34 - 35 /* And register the new performance domain */ - 36 em_register_perf_domain(policy->cpus, nr_opp, &em_cb); - 37 - 38 return 0; - 39 } + 01 static int est_power(unsigned long *mW, unsigned long *KHz, + 02 struct device *dev) + 03 { + 04 long freq, power; + 05 + 06 /* Use the 'foo' protocol to ceil the frequency */ + 07 freq = foo_get_freq_ceil(dev, *KHz); + 08 if (freq < 0); + 09 return freq; + 10 + 11 /* Estimate the power cost for the dev at the relevant freq. */ + 12 power = foo_estimate_power(dev, freq); + 13 if (power < 0); + 14 return power; + 15 + 16 /* Return the values to the EM framework */ + 17 *mW = power; + 18 *KHz = freq; + 19 + 20 return 0; + 21 } + 22 + 23 static int foo_cpufreq_init(struct cpufreq_policy *policy) + 24 { + 25 struct em_data_callback em_cb = EM_DATA_CB(est_power); + 26 struct device *cpu_dev; + 27 int nr_opp, ret; + 28 + 29 cpu_dev = get_cpu_device(cpumask_first(policy->cpus)); + 30 + 31 /* Do the actual CPUFreq init work ... */ + 32 ret = do_foo_cpufreq_init(policy); + 33 if (ret) + 34 return ret; + 35 + 36 /* Find the number of OPPs for this policy */ + 37 nr_opp = foo_get_nr_opp(policy); + 38 + 39 /* And register the new performance domain */ + 40 em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus); + 41 + 42 return 0; + 43 }

The Energy Model framework supports not only CPU devices. Drop the CPU specific interface with cpumask and add struct device. Add also a return value, user might use it. This new interface provides easy way to create a simple Energy Model, which then might be used by e.g. thermal subsystem.

Acked-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- drivers/cpufreq/cpufreq-dt.c | 2 +- drivers/cpufreq/imx6q-cpufreq.c | 2 +- drivers/cpufreq/mediatek-cpufreq.c | 2 +- drivers/cpufreq/omap-cpufreq.c | 2 +- drivers/cpufreq/qcom-cpufreq-hw.c | 2 +- drivers/cpufreq/scpi-cpufreq.c | 2 +- drivers/cpufreq/vexpress-spc-cpufreq.c | 2 +- drivers/opp/of.c | 71 ++++++++++++++++---------- include/linux/pm_opp.h | 15 +++++- 9 files changed, 65 insertions(+), 35 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c index 26fe8dfb9ce6..f9f03fd49b83 100644 --- a/drivers/cpufreq/cpufreq-dt.c +++ b/drivers/cpufreq/cpufreq-dt.c @@ -275,7 +275,7 @@ static int cpufreq_init(struct cpufreq_policy *policy) policy->cpuinfo.transition_latency = transition_latency; policy->dvfs_possible_from_any_cpu = true;

- dev_pm_opp_of_register_em(policy->cpus); + dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

return 0;

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c index fdb2ffffbd15..ef7b34c1fd2b 100644 --- a/drivers/cpufreq/imx6q-cpufreq.c +++ b/drivers/cpufreq/imx6q-cpufreq.c @@ -193,7 +193,7 @@ static int imx6q_cpufreq_init(struct cpufreq_policy *policy) policy->clk = clks[ARM].clk; cpufreq_generic_init(policy, freq_table, transition_latency); policy->suspend_freq = max_freq; - dev_pm_opp_of_register_em(policy->cpus); + dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

return 0; } diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c index 0c98dd08273d..7d1212c9b7c8 100644 --- a/drivers/cpufreq/mediatek-cpufreq.c +++ b/drivers/cpufreq/mediatek-cpufreq.c @@ -448,7 +448,7 @@ static int mtk_cpufreq_init(struct cpufreq_policy *policy) policy->driver_data = info; policy->clk = info->cpu_clk;

- dev_pm_opp_of_register_em(policy->cpus); + dev_pm_opp_of_register_em(info->cpu_dev, policy->cpus);

return 0; } diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c index 8d14b42a8c6f..3694bb030df3 100644 --- a/drivers/cpufreq/omap-cpufreq.c +++ b/drivers/cpufreq/omap-cpufreq.c @@ -131,7 +131,7 @@ static int omap_cpu_init(struct cpufreq_policy *policy)

/* FIXME: what's the actual transition time? */ cpufreq_generic_init(policy, freq_table, 300 * 1000); - dev_pm_opp_of_register_em(policy->cpus); + dev_pm_opp_of_register_em(mpu_dev, policy->cpus);

return 0; } diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c index fc92a8842e25..0a04b6f03b9a 100644 --- a/drivers/cpufreq/qcom-cpufreq-hw.c +++ b/drivers/cpufreq/qcom-cpufreq-hw.c @@ -238,7 +238,7 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) goto error; }

- dev_pm_opp_of_register_em(policy->cpus); + dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

policy->fast_switch_possible = true;

diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c index 20d1f85d5f5a..b0f5388b8854 100644 --- a/drivers/cpufreq/scpi-cpufreq.c +++ b/drivers/cpufreq/scpi-cpufreq.c @@ -167,7 +167,7 @@ static int scpi_cpufreq_init(struct cpufreq_policy *policy)

policy->fast_switch_possible = false;

- dev_pm_opp_of_register_em(policy->cpus); + dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

return 0;

diff --git a/drivers/cpufreq/vexpress-spc-cpufreq.c b/drivers/cpufreq/vexpress-spc-cpufreq.c index 83c85d3d67e3..4e8b1dee7c9a 100644 --- a/drivers/cpufreq/vexpress-spc-cpufreq.c +++ b/drivers/cpufreq/vexpress-spc-cpufreq.c @@ -450,7 +450,7 @@ static int ve_spc_cpufreq_init(struct cpufreq_policy *policy) policy->freq_table = freq_table[cur_cluster]; policy->cpuinfo.transition_latency = 1000000; /* 1 ms */

- dev_pm_opp_of_register_em(policy->cpus); + dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

if (is_bL_switching_enabled()) per_cpu(cpu_last_req_freq, policy->cpu) = diff --git a/drivers/opp/of.c b/drivers/opp/of.c index 5b75829a915d..4500ce46d476 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -1036,18 +1036,18 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);

/* * Callback function provided to the Energy Model framework upon registration. - * This computes the power estimated by @CPU at @kHz if it is the frequency + * 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 - * P = C * V^2 * f with C being the CPU's capacitance and V and f respectively - * the voltage and frequency of the OPP. + * 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 -ENODEV if the CPU device cannot be found, -EINVAL if the power - * calculation failed because of missing parameters, 0 otherwise. + * Returns -EINVAL if the power calculation failed because of missing + * parameters, 0 otherwise. */ -static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz, - struct device *cpu_dev) +static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz, + struct device *dev) { struct dev_pm_opp *opp; struct device_node *np; @@ -1056,7 +1056,7 @@ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz, u64 tmp; int ret;

- np = of_node_get(cpu_dev->of_node); + np = of_node_get(dev->of_node); if (!np) return -EINVAL;

@@ -1066,7 +1066,7 @@ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz, return -EINVAL;

Hz = *kHz * 1000; - opp = dev_pm_opp_find_freq_ceil(cpu_dev, &Hz); + opp = dev_pm_opp_find_freq_ceil(dev, &Hz); if (IS_ERR(opp)) return -EINVAL;

@@ -1086,30 +1086,38 @@ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,

/** * dev_pm_opp_of_register_em() - Attempt to register an Energy Model - * @cpus : CPUs for which an Energy Model has to be registered + * @dev : Device for which an Energy Model has to be registered + * @cpus : CPUs for which an Energy Model has to be registered. For + * other type of devices it should be set to NULL. * * This checks whether the "dynamic-power-coefficient" devicetree property has * been specified, and tries to register an Energy Model with it if it has. + * Having this property means the voltages are known for OPPs and the EM + * might be calculated. */ -void dev_pm_opp_of_register_em(struct cpumask *cpus) +int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus) { - struct em_data_callback em_cb = EM_DATA_CB(_get_cpu_power); - int ret, nr_opp, cpu = cpumask_first(cpus); - struct device *cpu_dev; + struct em_data_callback em_cb = EM_DATA_CB(_get_power); struct device_node *np; + int ret, nr_opp; u32 cap;

- cpu_dev = get_cpu_device(cpu); - if (!cpu_dev) - return; + if (IS_ERR_OR_NULL(dev)) { + ret = -EINVAL; + goto failed; + }

- nr_opp = dev_pm_opp_get_opp_count(cpu_dev); - if (nr_opp <= 0) - return; + nr_opp = dev_pm_opp_get_opp_count(dev); + if (nr_opp <= 0) { + ret = -EINVAL; + goto failed; + }

- np = of_node_get(cpu_dev->of_node); - if (!np) - return; + np = of_node_get(dev->of_node); + if (!np) { + ret = -EINVAL; + goto failed; + }

/* * Register an EM only if the 'dynamic-power-coefficient' property is @@ -1120,9 +1128,20 @@ void dev_pm_opp_of_register_em(struct cpumask *cpus) */ ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap); of_node_put(np); - if (ret || !cap) - return; + if (ret || !cap) { + dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n"); + ret = -EINVAL; + goto failed; + }

- em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, cpus); + ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus); + if (ret) + goto failed; + + return 0; + +failed: + dev_dbg(dev, "Couldn't register Energy Model %d\n", ret); + return ret; } EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em); diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 747861816f4f..8df8b82054e5 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -11,6 +11,7 @@ #ifndef __LINUX_OPP_H__ #define __LINUX_OPP_H__

+#include <linux/energy_model.h> #include <linux/err.h> #include <linux/notifier.h>

@@ -360,7 +361,11 @@ int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpuma struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev); struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp); int of_get_required_opp_performance_state(struct device_node *np, int index); -void dev_pm_opp_of_register_em(struct cpumask *cpus); +int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus); +static inline void dev_pm_opp_of_unregister_em(struct device *dev) +{ + em_dev_unregister_perf_domain(dev); +} #else static inline int dev_pm_opp_of_add_table(struct device *dev) { @@ -400,7 +405,13 @@ static inline struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp) return NULL; }

-static inline void dev_pm_opp_of_register_em(struct cpumask *cpus) +static inline int dev_pm_opp_of_register_em(struct device *dev, + struct cpumask *cpus) +{ + return -ENOTSUPP; +} + +static inline void dev_pm_opp_of_unregister_em(struct device *dev) { }

Devfreq cooling needs to now the correct status of the device in order to operate. Do not rely on Devfreq last_status which might be a stale data and get more up-to-date values of load and frequency.

In addition this patch adds normalization function, which also makes sure that whatever data comes from the device, it is in a sane range.

Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- drivers/thermal/devfreq_cooling.c | 38 +++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c index 52694d4bd819..396f16bb6566 100644 --- a/drivers/thermal/devfreq_cooling.c +++ b/drivers/thermal/devfreq_cooling.c @@ -235,6 +235,24 @@ static inline unsigned long get_total_power(struct devfreq_cooling_device *dfc, voltage); }

+static void _normalize_load(struct devfreq_dev_status *status) +{ + /* Make some space if needed */ + if (status->busy_time > 0xffff) { + status->busy_time >>= 10; + status->total_time >>= 10; + } + + if (status->busy_time > status->total_time) + status->busy_time = status->total_time; + + status->busy_time *= 100; + status->busy_time /= status->total_time ? : 1; + + /* Avoid division by 0 */ + status->busy_time = status->busy_time ? : 1; + status->total_time = 100; +}

static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev, struct thermal_zone_device *tz, @@ -242,14 +260,22 @@ static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cd { struct devfreq_cooling_device *dfc = cdev->devdata; struct devfreq *df = dfc->devfreq; - struct devfreq_dev_status *status = &df->last_status; + struct devfreq_dev_status status; unsigned long state; - unsigned long freq = status->current_frequency; + unsigned long freq; unsigned long voltage; u32 dyn_power = 0; u32 static_power = 0; int res;

+ 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; + state = freq_get_state(dfc, freq); if (state == THERMAL_CSTATE_INVALID) { res = -EAGAIN; @@ -277,16 +303,18 @@ static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cd } else { dyn_power = dfc->power_table[state];

+ _normalize_load(&status); + /* Scale dynamic power for utilization */ - dyn_power *= status->busy_time; - dyn_power /= status->total_time; + 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, *power); + trace_thermal_power_devfreq_get_power(cdev, &status, freq, *power);

return 0; fail:

The Energy Model (EM) framework supports devices such as Devfreq. Create new registration functions which automatically register EM for the thermal devfreq_cooling devices. This patch prepares the code for coming changes which are going to replace old power model with the new EM.

Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- drivers/thermal/devfreq_cooling.c | 99 ++++++++++++++++++++++++++++++- include/linux/devfreq_cooling.h | 22 +++++++ 2 files changed, 120 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c index 36ec6a48606c..c7ffed2d6ee0 100644 --- a/drivers/thermal/devfreq_cooling.c +++ b/drivers/thermal/devfreq_cooling.c @@ -58,6 +58,8 @@ static DEFINE_IDA(devfreq_ida); * @capped_state: index to cooling state with in dynamic power budget * @req_max_freq: PM QoS request for limiting the maximum frequency * of the devfreq device. + * @em: Energy Model which represents the associated Devfreq device + * @em_registered: Devfreq cooling registered the EM and should free it. */ struct devfreq_cooling_device { int id; @@ -71,6 +73,8 @@ struct devfreq_cooling_device { u32 res_util; int capped_state; struct dev_pm_qos_request req_max_freq; + struct em_perf_domain *em; + bool em_registered; };

static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev, @@ -594,22 +598,115 @@ struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df) } EXPORT_SYMBOL_GPL(devfreq_cooling_register);

+/** + * devfreq_cooling_em_register_power() - Register devfreq cooling device with + * power information and attempt to register Energy Model (EM) + * @df: Pointer to devfreq device. + * @dfc_power: Pointer to devfreq_cooling_power. + * @em_cb: Callback functions providing the data of the EM + * + * Register a devfreq cooling device and attempt to register Energy Model. The + * available OPPs must be registered for the device. + * + * If @dfc_power is provided, the cooling device is registered with the + * power extensions. If @em_cb is provided it will be called for each OPP to + * calculate power value and cost. If @em_cb is not provided then simple Energy + * Model is going to be used, which requires "dynamic-power-coefficient" a + * devicetree property. + */ +struct thermal_cooling_device * +devfreq_cooling_em_register_power(struct devfreq *df, + struct devfreq_cooling_power *dfc_power, + struct em_data_callback *em_cb) +{ + struct thermal_cooling_device *cdev; + struct devfreq_cooling_device *dfc; + struct device_node *np = NULL; + struct device *dev; + int nr_opp, ret; + + if (IS_ERR_OR_NULL(df)) + return ERR_PTR(-EINVAL); + + dev = df->dev.parent; + + if (em_cb) { + nr_opp = dev_pm_opp_get_opp_count(dev); + if (nr_opp <= 0) { + dev_err(dev, "No valid OPPs found\n"); + return ERR_PTR(-EINVAL); + } + + ret = em_dev_register_perf_domain(dev, nr_opp, em_cb, NULL); + } else { + ret = dev_pm_opp_of_register_em(dev, NULL); + } + + if (ret) + dev_warn(dev, "Unable to register EM for devfreq cooling device (%d)\n", + ret); + + if (dev->of_node) + np = of_node_get(dev->of_node); + + cdev = of_devfreq_cooling_register_power(np, df, dfc_power); + + if (np) + of_node_put(np); + + if (IS_ERR_OR_NULL(cdev)) { + if (!ret) + em_dev_unregister_perf_domain(dev); + } else { + dfc = cdev->devdata; + dfc->em_registered = !ret; + } + + return cdev; +} +EXPORT_SYMBOL_GPL(devfreq_cooling_em_register_power); + +/** + * devfreq_cooling_em_register() - Register devfreq cooling device together + * with Energy Model. + * @df: Pointer to devfreq device. + * @em_cb: Callback functions providing the data of the Energy Model + * + * This function attempts to register Energy Model for devfreq device and then + * register the devfreq cooling device. + */ +struct thermal_cooling_device * +devfreq_cooling_em_register(struct devfreq *df, struct em_data_callback *em_cb) +{ + return devfreq_cooling_em_register_power(df, NULL, em_cb); +} +EXPORT_SYMBOL_GPL(devfreq_cooling_em_register); + /** * devfreq_cooling_unregister() - Unregister devfreq cooling device. * @cdev: Pointer to devfreq cooling device to unregister. + * + * Unregisters devfreq cooling device and related Energy Model if it was + * present. */ void devfreq_cooling_unregister(struct thermal_cooling_device *cdev) { struct devfreq_cooling_device *dfc; + struct device *dev;

- if (!cdev) + if (IS_ERR_OR_NULL(cdev)) return;

dfc = cdev->devdata; + dev = dfc->devfreq->dev.parent;

thermal_cooling_device_unregister(dfc->cdev); ida_simple_remove(&devfreq_ida, dfc->id); dev_pm_qos_remove_request(&dfc->req_max_freq); + + if (dfc->em_registered) + em_dev_unregister_perf_domain(dev); + kfree(dfc->power_table); kfree(dfc->freq_table);

diff --git a/include/linux/devfreq_cooling.h b/include/linux/devfreq_cooling.h index 79a6e37a1d6f..07df019fcb66 100644 --- a/include/linux/devfreq_cooling.h +++ b/include/linux/devfreq_cooling.h @@ -18,6 +18,7 @@ #define __DEVFREQ_COOLING_H__

#include <linux/devfreq.h> +#include <linux/energy_model.h> #include <linux/thermal.h>

@@ -72,6 +73,13 @@ struct thermal_cooling_device * of_devfreq_cooling_register(struct device_node *np, struct devfreq *df); struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df); void devfreq_cooling_unregister(struct thermal_cooling_device *dfc); +struct thermal_cooling_device * +devfreq_cooling_em_register_power(struct devfreq *df, + struct devfreq_cooling_power *dfc_power, + struct em_data_callback *em_cb); +struct thermal_cooling_device * +devfreq_cooling_em_register(struct devfreq *df, + struct em_data_callback *em_cb);

#else /* !CONFIG_DEVFREQ_THERMAL */

@@ -94,6 +102,20 @@ devfreq_cooling_register(struct devfreq *df) return ERR_PTR(-EINVAL); }

+static inline struct thermal_cooling_device * +devfreq_cooling_em_register_power(struct devfreq *df, + struct devfreq_cooling_power *dfc_power, + struct em_data_callback *em_cb) +{ + return ERR_PTR(-EINVAL); +} + +static inline struct thermal_cooling_device * +devfreq_cooling_em_register(struct devfreq *df, struct em_data_callback *em_cb) +{ + return ERR_PTR(-EINVAL); +} + static inline void devfreq_cooling_unregister(struct thermal_cooling_device *dfc) {

Change the license headers and use SPDX standard.

Signed-off-by: Lukasz Luba lukasz.luba@arm.com --- drivers/thermal/devfreq_cooling.c | 12 ++---------- include/linux/devfreq_cooling.h | 12 ++---------- 2 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c index 79dcef3dbeeb..77d996fd82d2 100644 --- a/drivers/thermal/devfreq_cooling.c +++ b/drivers/thermal/devfreq_cooling.c @@ -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 diff --git a/include/linux/devfreq_cooling.h b/include/linux/devfreq_cooling.h index 613678ce23df..1f5c07c78f0f 100644 --- a/include/linux/devfreq_cooling.h +++ b/include/linux/devfreq_cooling.h @@ -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 */

#ifndef __DEVFREQ_COOLING_H__