diff options
Diffstat (limited to 'kernel/power/energy_model.c')
-rw-r--r-- | kernel/power/energy_model.c | 891 |
1 files changed, 780 insertions, 111 deletions
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 0a9326f5f421..3874f0e97651 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -1,44 +1,101 @@ // SPDX-License-Identifier: GPL-2.0 /* - * Energy Model of CPUs + * Energy Model of devices * - * Copyright (c) 2018, Arm ltd. + * Copyright (c) 2018-2021, Arm ltd. * Written by: Quentin Perret, Arm ltd. + * Improvements provided by: Lukasz Luba, Arm ltd. */ #define pr_fmt(fmt) "energy_model: " fmt #include <linux/cpu.h> +#include <linux/cpufreq.h> #include <linux/cpumask.h> #include <linux/debugfs.h> #include <linux/energy_model.h> #include <linux/sched/topology.h> #include <linux/slab.h> -/* Mapping of each CPU to the performance domain to which it belongs. */ -static DEFINE_PER_CPU(struct em_perf_domain *, em_data); - /* * Mutex serializing the registrations of performance domains and letting * callbacks defined by drivers sleep. */ static DEFINE_MUTEX(em_pd_mutex); +static void em_cpufreq_update_efficiencies(struct device *dev, + struct em_perf_state *table); +static void em_check_capacity_update(void); +static void em_update_workfn(struct work_struct *work); +static DECLARE_DELAYED_WORK(em_update_work, em_update_workfn); + +static bool _is_cpu_device(struct device *dev) +{ + return (dev->bus == &cpu_subsys); +} + #ifdef CONFIG_DEBUG_FS static struct dentry *rootdir; -static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd) +struct em_dbg_info { + struct em_perf_domain *pd; + int ps_id; +}; + +#define DEFINE_EM_DBG_SHOW(name, fname) \ +static int em_debug_##fname##_show(struct seq_file *s, void *unused) \ +{ \ + struct em_dbg_info *em_dbg = s->private; \ + struct em_perf_state *table; \ + unsigned long val; \ + \ + rcu_read_lock(); \ + table = em_perf_state_from_pd(em_dbg->pd); \ + val = table[em_dbg->ps_id].name; \ + rcu_read_unlock(); \ + \ + seq_printf(s, "%lu\n", val); \ + return 0; \ +} \ +DEFINE_SHOW_ATTRIBUTE(em_debug_##fname) + +DEFINE_EM_DBG_SHOW(frequency, frequency); +DEFINE_EM_DBG_SHOW(power, power); +DEFINE_EM_DBG_SHOW(cost, cost); +DEFINE_EM_DBG_SHOW(performance, performance); +DEFINE_EM_DBG_SHOW(flags, inefficiency); + +static void em_debug_create_ps(struct em_perf_domain *em_pd, + struct em_dbg_info *em_dbg, int i, + struct dentry *pd) { + struct em_perf_state *table; + unsigned long freq; struct dentry *d; char name[24]; - snprintf(name, sizeof(name), "cs:%lu", cs->frequency); + em_dbg[i].pd = em_pd; + em_dbg[i].ps_id = i; + + rcu_read_lock(); + table = em_perf_state_from_pd(em_pd); + freq = table[i].frequency; + rcu_read_unlock(); - /* Create per-cs directory */ + snprintf(name, sizeof(name), "ps:%lu", freq); + + /* 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_file("frequency", 0444, d, &em_dbg[i], + &em_debug_frequency_fops); + debugfs_create_file("power", 0444, d, &em_dbg[i], + &em_debug_power_fops); + debugfs_create_file("cost", 0444, d, &em_dbg[i], + &em_debug_cost_fops); + debugfs_create_file("performance", 0444, d, &em_dbg[i], + &em_debug_performance_fops); + debugfs_create_file("inefficient", 0444, d, &em_dbg[i], + &em_debug_inefficiency_fops); } static int em_debug_cpus_show(struct seq_file *s, void *unused) @@ -49,22 +106,46 @@ static int em_debug_cpus_show(struct seq_file *s, void *unused) } DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) +static int em_debug_flags_show(struct seq_file *s, void *unused) +{ + struct em_perf_domain *pd = s->private; + + seq_printf(s, "%#lx\n", pd->flags); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(em_debug_flags); + +static void em_debug_create_pd(struct device *dev) { + struct em_dbg_info *em_dbg; struct dentry *d; - char name[8]; int i; - snprintf(name, sizeof(name), "pd%d", cpu); - /* Create the directory of the performance domain */ - d = debugfs_create_dir(name, rootdir); + d = debugfs_create_dir(dev_name(dev), rootdir); + + if (_is_cpu_device(dev)) + debugfs_create_file("cpus", 0444, d, dev->em_pd->cpus, + &em_debug_cpus_fops); + + debugfs_create_file("flags", 0444, d, dev->em_pd, + &em_debug_flags_fops); + + em_dbg = devm_kcalloc(dev, dev->em_pd->nr_perf_states, + sizeof(*em_dbg), GFP_KERNEL); + if (!em_dbg) + return; - debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); + /* Create a sub-directory for each performance state */ + for (i = 0; i < dev->em_pd->nr_perf_states; i++) + em_debug_create_ps(dev->em_pd, em_dbg, i, d); - /* 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); +} + +static void em_debug_remove_pd(struct device *dev) +{ + debugfs_lookup_and_remove(dev_name(dev), rootdir); } static int __init em_debug_init(void) @@ -74,136 +155,415 @@ static int __init em_debug_init(void) return 0; } -core_initcall(em_debug_init); +fs_initcall(em_debug_init); #else /* CONFIG_DEBUG_FS */ -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} +static void em_debug_create_pd(struct device *dev) {} +static void em_debug_remove_pd(struct device *dev) {} #endif -static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, - struct em_data_callback *cb) + +static void em_destroy_table_rcu(struct rcu_head *rp) { - 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_domain *pd; - u64 fmax; + struct em_perf_table __rcu *table; - if (!cb->active_power) - return NULL; + table = container_of(rp, struct em_perf_table, rcu); + kfree(table); +} - pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); - if (!pd) - return NULL; +static void em_release_table_kref(struct kref *kref) +{ + struct em_perf_table __rcu *table; + + /* It was the last owner of this table so we can free */ + table = container_of(kref, struct em_perf_table, kref); + + call_rcu(&table->rcu, em_destroy_table_rcu); +} + +/** + * em_table_free() - Handles safe free of the EM table when needed + * @table : EM table which is going to be freed + * + * No return values. + */ +void em_table_free(struct em_perf_table __rcu *table) +{ + kref_put(&table->kref, em_release_table_kref); +} + +/** + * em_table_alloc() - Allocate a new EM table + * @pd : EM performance domain for which this must be done + * + * Allocate a new EM table and initialize its kref to indicate that it + * has a user. + * Returns allocated table or NULL. + */ +struct em_perf_table __rcu *em_table_alloc(struct em_perf_domain *pd) +{ + struct em_perf_table __rcu *table; + int table_size; + + table_size = sizeof(struct em_perf_state) * pd->nr_perf_states; - table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL); + table = kzalloc(sizeof(*table) + table_size, GFP_KERNEL); if (!table) - goto free_pd; + return NULL; + + kref_init(&table->kref); + + return table; +} + +static void em_init_performance(struct device *dev, struct em_perf_domain *pd, + struct em_perf_state *table, int nr_states) +{ + u64 fmax, max_cap; + int i, cpu; + + /* This is needed only for CPUs and EAS skip other devices */ + if (!_is_cpu_device(dev)) + return; + + cpu = cpumask_first(em_span_cpus(pd)); + + /* + * Calculate the performance value for each frequency with + * linear relationship. The final CPU capacity might not be ready at + * boot time, but the EM will be updated a bit later with correct one. + */ + fmax = (u64) table[nr_states - 1].frequency; + max_cap = (u64) arch_scale_cpu_capacity(cpu); + for (i = 0; i < nr_states; i++) + table[i].performance = div64_u64(max_cap * table[i].frequency, + fmax); +} + +static int em_compute_costs(struct device *dev, struct em_perf_state *table, + struct em_data_callback *cb, int nr_states, + unsigned long flags) +{ + unsigned long prev_cost = ULONG_MAX; + int i, ret; + + /* Compute the cost of each performance state. */ + for (i = nr_states - 1; i >= 0; i--) { + unsigned long power_res, cost; + + if ((flags & EM_PERF_DOMAIN_ARTIFICIAL) && cb->get_cost) { + ret = cb->get_cost(dev, table[i].frequency, &cost); + if (ret || !cost || cost > EM_MAX_POWER) { + dev_err(dev, "EM: invalid cost %lu %d\n", + cost, ret); + return -EINVAL; + } + } else { + /* increase resolution of 'cost' precision */ + power_res = table[i].power * 10; + cost = power_res / table[i].performance; + } + + table[i].cost = cost; + + if (table[i].cost >= prev_cost) { + table[i].flags = EM_PERF_STATE_INEFFICIENT; + dev_dbg(dev, "EM: OPP:%lu is inefficient\n", + table[i].frequency); + } else { + prev_cost = table[i].cost; + } + } + + return 0; +} + +/** + * em_dev_compute_costs() - Calculate cost values for new runtime EM table + * @dev : Device for which the EM table is to be updated + * @table : The new EM table that is going to get the costs calculated + * @nr_states : Number of performance states + * + * Calculate the em_perf_state::cost values for new runtime EM table. The + * values are used for EAS during task placement. It also calculates and sets + * the efficiency flag for each performance state. When the function finish + * successfully the EM table is ready to be updated and used by EAS. + * + * Return 0 on success or a proper error in case of failure. + */ +int em_dev_compute_costs(struct device *dev, struct em_perf_state *table, + int nr_states) +{ + return em_compute_costs(dev, table, NULL, nr_states, 0); +} + +/** + * em_dev_update_perf_domain() - Update runtime EM table for a device + * @dev : Device for which the EM is to be updated + * @new_table : The new EM table that is going to be used from now + * + * Update EM runtime modifiable table for the @dev using the provided @table. + * + * This function uses a mutex to serialize writers, so it must not be called + * from a non-sleeping context. + * + * Return 0 on success or an error code on failure. + */ +int em_dev_update_perf_domain(struct device *dev, + struct em_perf_table __rcu *new_table) +{ + struct em_perf_table __rcu *old_table; + struct em_perf_domain *pd; + + if (!dev) + return -EINVAL; + + /* Serialize update/unregister or concurrent updates */ + mutex_lock(&em_pd_mutex); + + if (!dev->em_pd) { + mutex_unlock(&em_pd_mutex); + return -EINVAL; + } + pd = dev->em_pd; + + kref_get(&new_table->kref); + + old_table = pd->em_table; + rcu_assign_pointer(pd->em_table, new_table); + + em_cpufreq_update_efficiencies(dev, new_table->state); + + em_table_free(old_table); + + mutex_unlock(&em_pd_mutex); + return 0; +} +EXPORT_SYMBOL_GPL(em_dev_update_perf_domain); - /* Build the list of capacity states for this performance domain */ +static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, + struct em_perf_state *table, + struct em_data_callback *cb, + unsigned long flags) +{ + unsigned long power, freq, prev_freq = 0; + int nr_states = pd->nr_perf_states; + int i, ret; + + /* 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 'dev' above 'freq' and updates * 'power' and 'freq' accordingly. */ - ret = cb->active_power(&power, &freq, cpu); + ret = cb->active_power(dev, &power, &freq); if (ret) { - pr_err("pd%d: invalid cap. state: %d\n", cpu, ret); - goto free_cs_table; + dev_err(dev, "EM: invalid perf. state: %d\n", + ret); + return -EINVAL; } /* * 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; + dev_err(dev, "EM: non-increasing freq: %lu\n", + freq); + return -EINVAL; } /* * The power returned by active_state() is expected to be - * positive, in milli-watts and to fit into 16 bits. + * positive and be in range. */ - if (!power || power > EM_CPU_MAX_POWER) { - pr_err("pd%d: invalid power: %lu\n", cpu, power); - goto free_cs_table; + if (!power || power > EM_MAX_POWER) { + dev_err(dev, "EM: invalid power: %lu\n", + power); + return -EINVAL; } table[i].power = power; table[i].frequency = prev_freq = freq; - - /* - * The hertz/watts efficiency ratio should decrease as the - * frequency grows on sane platforms. But this isn't always - * true in practice so warn the user if a higher OPP is more - * power efficient than a lower one. - */ - 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", - cpu, i, i - 1); - prev_opp_eff = opp_eff; } - /* Compute the cost of each capacity_state. */ - fmax = (u64) table[nr_states - 1].frequency; - for (i = 0; i < nr_states; i++) { - table[i].cost = div64_u64(fmax * table[i].power, - table[i].frequency); + em_init_performance(dev, pd, table, nr_states); + + ret = em_compute_costs(dev, table, cb, nr_states, flags); + if (ret) + return -EINVAL; + + return 0; +} + +static int em_create_pd(struct device *dev, int nr_states, + struct em_data_callback *cb, cpumask_t *cpus, + unsigned long flags) +{ + struct em_perf_table __rcu *em_table; + struct em_perf_domain *pd; + struct device *cpu_dev; + 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; + + cpumask_copy(em_span_cpus(pd), cpus); + } else { + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) + return -ENOMEM; } - pd->table = table; - pd->nr_cap_states = nr_states; - cpumask_copy(to_cpumask(pd->cpus), span); + pd->nr_perf_states = nr_states; - em_debug_create_pd(pd, cpu); + em_table = em_table_alloc(pd); + if (!em_table) + goto free_pd; - return pd; + ret = em_create_perf_table(dev, pd, em_table->state, cb, flags); + if (ret) + goto free_pd_table; -free_cs_table: - kfree(table); + rcu_assign_pointer(pd->em_table, em_table); + + if (_is_cpu_device(dev)) + for_each_cpu(cpu, cpus) { + cpu_dev = get_cpu_device(cpu); + cpu_dev->em_pd = pd; + } + + dev->em_pd = pd; + + return 0; + +free_pd_table: + kfree(em_table); free_pd: kfree(pd); + return -EINVAL; +} + +static void +em_cpufreq_update_efficiencies(struct device *dev, struct em_perf_state *table) +{ + struct em_perf_domain *pd = dev->em_pd; + struct cpufreq_policy *policy; + int found = 0; + int i, cpu; + + if (!_is_cpu_device(dev)) + return; + + /* Try to get a CPU which is active and in this PD */ + cpu = cpumask_first_and(em_span_cpus(pd), cpu_active_mask); + if (cpu >= nr_cpu_ids) { + dev_warn(dev, "EM: No online CPU for CPUFreq policy\n"); + return; + } + + policy = cpufreq_cpu_get(cpu); + if (!policy) { + dev_warn(dev, "EM: Access to CPUFreq policy failed\n"); + return; + } + + for (i = 0; i < pd->nr_perf_states; i++) { + if (!(table[i].flags & EM_PERF_STATE_INEFFICIENT)) + continue; + + if (!cpufreq_table_set_inefficient(policy, table[i].frequency)) + found++; + } + + cpufreq_cpu_put(policy); + + if (!found) + return; + + /* + * Efficiencies have been installed in CPUFreq, inefficient frequencies + * will be skipped. The EM can do the same. + */ + pd->flags |= EM_PERF_DOMAIN_SKIP_INEFFICIENCIES; +} + +/** + * em_pd_get() - Return the performance domain for a device + * @dev : Device to find the performance domain for + * + * Returns the performance domain to which @dev belongs, or NULL if it doesn't + * exist. + */ +struct em_perf_domain *em_pd_get(struct device *dev) +{ + if (IS_ERR_OR_NULL(dev)) + return NULL; - return NULL; + return dev->em_pd; } +EXPORT_SYMBOL_GPL(em_pd_get); /** * em_cpu_get() - Return the performance domain for a CPU * @cpu : CPU to find the performance domain for * - * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't + * Returns the performance domain to which @cpu belongs, or NULL if it doesn't * exist. */ struct em_perf_domain *em_cpu_get(int cpu) { - return READ_ONCE(per_cpu(em_data, cpu)); + struct device *cpu_dev; + + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) + return NULL; + + return em_pd_get(cpu_dev); } 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 + * 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 + * @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. + * @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 @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. + * * 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) +int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, + struct em_data_callback *cb, cpumask_t *cpus, + bool microwatts) { unsigned long cap, prev_cap = 0; - struct em_perf_domain *pd; - int cpu, ret = 0; + unsigned long flags = 0; + int cpu, ret; - if (!span || !nr_states || !cb) + if (!dev || !nr_states || !cb) return -EINVAL; /* @@ -212,47 +572,356 @@ int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, */ mutex_lock(&em_pd_mutex); - for_each_cpu(cpu, span) { - /* Make sure we don't register again an existing domain. */ - if (READ_ONCE(per_cpu(em_data, cpu))) { - ret = -EEXIST; - goto unlock; - } + if (dev->em_pd) { + ret = -EEXIST; + goto unlock; + } - /* - * All CPUs of a domain must have the same micro-architecture - * since they all share the same table. - */ - cap = arch_scale_cpu_capacity(cpu); - if (prev_cap && prev_cap != cap) { - pr_err("CPUs of %*pbl must have the same capacity\n", - cpumask_pr_args(span)); + if (_is_cpu_device(dev)) { + if (!cpus) { + dev_err(dev, "EM: invalid CPU mask\n"); ret = -EINVAL; goto unlock; } - prev_cap = cap; + + for_each_cpu(cpu, cpus) { + if (em_cpu_get(cpu)) { + dev_err(dev, "EM: exists for CPU%d\n", cpu); + ret = -EEXIST; + goto unlock; + } + /* + * All CPUs of a domain must have the same + * micro-architecture since they all share the same + * table. + */ + cap = arch_scale_cpu_capacity(cpu); + if (prev_cap && prev_cap != cap) { + dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n", + cpumask_pr_args(cpus)); + + ret = -EINVAL; + goto unlock; + } + prev_cap = cap; + } } - /* Create the performance domain and add it to the Energy Model. */ - pd = em_create_pd(span, nr_states, cb); - if (!pd) { + if (microwatts) + flags |= EM_PERF_DOMAIN_MICROWATTS; + else if (cb->get_cost) + flags |= EM_PERF_DOMAIN_ARTIFICIAL; + + /* + * EM only supports uW (exception is artificial EM). + * Therefore, check and force the drivers to provide + * power in uW. + */ + if (!microwatts && !(flags & EM_PERF_DOMAIN_ARTIFICIAL)) { + dev_err(dev, "EM: only supports uW power values\n"); ret = -EINVAL; goto unlock; } - for_each_cpu(cpu, span) { + ret = em_create_pd(dev, nr_states, cb, cpus, flags); + if (ret) + goto unlock; + + dev->em_pd->flags |= flags; + dev->em_pd->min_perf_state = 0; + dev->em_pd->max_perf_state = nr_states - 1; + + em_cpufreq_update_efficiencies(dev, dev->em_pd->em_table->state); + + em_debug_create_pd(dev); + dev_info(dev, "EM: created perf domain\n"); + +unlock: + mutex_unlock(&em_pd_mutex); + + if (_is_cpu_device(dev)) + em_check_capacity_update(); + + return ret; +} +EXPORT_SYMBOL_GPL(em_dev_register_perf_domain); + +/** + * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device + * @dev : Device for which the EM is registered + * + * Unregister the EM for the specified @dev (but not a CPU device). + */ +void em_dev_unregister_perf_domain(struct device *dev) +{ + if (IS_ERR_OR_NULL(dev) || !dev->em_pd) + return; + + if (_is_cpu_device(dev)) + return; + + /* + * The mutex separates all register/unregister requests and protects + * from potential clean-up/setup issues in the debugfs directories. + * The debugfs directory name is the same as device's name. + */ + mutex_lock(&em_pd_mutex); + em_debug_remove_pd(dev); + + em_table_free(dev->em_pd->em_table); + + kfree(dev->em_pd); + dev->em_pd = NULL; + mutex_unlock(&em_pd_mutex); +} +EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain); + +static struct em_perf_table __rcu *em_table_dup(struct em_perf_domain *pd) +{ + struct em_perf_table __rcu *em_table; + struct em_perf_state *ps, *new_ps; + int ps_size; + + em_table = em_table_alloc(pd); + if (!em_table) + return NULL; + + new_ps = em_table->state; + + rcu_read_lock(); + ps = em_perf_state_from_pd(pd); + /* Initialize data based on old table */ + ps_size = sizeof(struct em_perf_state) * pd->nr_perf_states; + memcpy(new_ps, ps, ps_size); + + rcu_read_unlock(); + + return em_table; +} + +static int em_recalc_and_update(struct device *dev, struct em_perf_domain *pd, + struct em_perf_table __rcu *em_table) +{ + int ret; + + ret = em_compute_costs(dev, em_table->state, NULL, pd->nr_perf_states, + pd->flags); + if (ret) + goto free_em_table; + + ret = em_dev_update_perf_domain(dev, em_table); + if (ret) + goto free_em_table; + + /* + * This is one-time-update, so give up the ownership in this updater. + * The EM framework has incremented the usage counter and from now + * will keep the reference (then free the memory when needed). + */ +free_em_table: + em_table_free(em_table); + return ret; +} + +/* + * Adjustment of CPU performance values after boot, when all CPUs capacites + * are correctly calculated. + */ +static void em_adjust_new_capacity(struct device *dev, + struct em_perf_domain *pd, + u64 max_cap) +{ + struct em_perf_table __rcu *em_table; + + em_table = em_table_dup(pd); + if (!em_table) { + dev_warn(dev, "EM: allocation failed\n"); + return; + } + + em_init_performance(dev, pd, em_table->state, pd->nr_perf_states); + + em_recalc_and_update(dev, pd, em_table); +} + +static void em_check_capacity_update(void) +{ + cpumask_var_t cpu_done_mask; + struct em_perf_state *table; + struct em_perf_domain *pd; + unsigned long cpu_capacity; + int cpu; + + if (!zalloc_cpumask_var(&cpu_done_mask, GFP_KERNEL)) { + pr_warn("no free memory\n"); + return; + } + + /* Check if CPUs capacity has changed than update EM */ + for_each_possible_cpu(cpu) { + struct cpufreq_policy *policy; + unsigned long em_max_perf; + struct device *dev; + + if (cpumask_test_cpu(cpu, cpu_done_mask)) + continue; + + policy = cpufreq_cpu_get(cpu); + if (!policy) { + pr_debug("Accessing cpu%d policy failed\n", cpu); + schedule_delayed_work(&em_update_work, + msecs_to_jiffies(1000)); + break; + } + cpufreq_cpu_put(policy); + + pd = em_cpu_get(cpu); + if (!pd || em_is_artificial(pd)) + continue; + + cpumask_or(cpu_done_mask, cpu_done_mask, + em_span_cpus(pd)); + + cpu_capacity = arch_scale_cpu_capacity(cpu); + + rcu_read_lock(); + table = em_perf_state_from_pd(pd); + em_max_perf = table[pd->nr_perf_states - 1].performance; + rcu_read_unlock(); + /* - * The per-cpu array can be read concurrently from em_cpu_get(). - * The barrier enforces the ordering needed to make sure readers - * can only access well formed em_perf_domain structs. + * Check if the CPU capacity has been adjusted during boot + * and trigger the update for new performance values. */ - smp_store_release(per_cpu_ptr(&em_data, cpu), pd); + if (em_max_perf == cpu_capacity) + continue; + + pr_debug("updating cpu%d cpu_cap=%lu old capacity=%lu\n", + cpu, cpu_capacity, em_max_perf); + + dev = get_cpu_device(cpu); + em_adjust_new_capacity(dev, pd, cpu_capacity); } - pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span)); -unlock: + free_cpumask_var(cpu_done_mask); +} + +static void em_update_workfn(struct work_struct *work) +{ + em_check_capacity_update(); +} + +/** + * em_dev_update_chip_binning() - Update Energy Model after the new voltage + * information is present in the OPPs. + * @dev : Device for which the Energy Model has to be updated. + * + * This function allows to update easily the EM with new values available in + * the OPP framework and DT. It can be used after the chip has been properly + * verified by device drivers and the voltages adjusted for the 'chip binning'. + */ +int em_dev_update_chip_binning(struct device *dev) +{ + struct em_perf_table __rcu *em_table; + struct em_perf_domain *pd; + int i, ret; + + if (IS_ERR_OR_NULL(dev)) + return -EINVAL; + + pd = em_pd_get(dev); + if (!pd) { + dev_warn(dev, "Couldn't find Energy Model\n"); + return -EINVAL; + } + + em_table = em_table_dup(pd); + if (!em_table) { + dev_warn(dev, "EM: allocation failed\n"); + return -ENOMEM; + } + + /* Update power values which might change due to new voltage in OPPs */ + for (i = 0; i < pd->nr_perf_states; i++) { + unsigned long freq = em_table->state[i].frequency; + unsigned long power; + + ret = dev_pm_opp_calc_power(dev, &power, &freq); + if (ret) { + em_table_free(em_table); + return ret; + } + + em_table->state[i].power = power; + } + + return em_recalc_and_update(dev, pd, em_table); +} +EXPORT_SYMBOL_GPL(em_dev_update_chip_binning); + + +/** + * em_update_performance_limits() - Update Energy Model with performance + * limits information. + * @pd : Performance Domain with EM that has to be updated. + * @freq_min_khz : New minimum allowed frequency for this device. + * @freq_max_khz : New maximum allowed frequency for this device. + * + * This function allows to update the EM with information about available + * performance levels. It takes the minimum and maximum frequency in kHz + * and does internal translation to performance levels. + * Returns 0 on success or -EINVAL when failed. + */ +int em_update_performance_limits(struct em_perf_domain *pd, + unsigned long freq_min_khz, unsigned long freq_max_khz) +{ + struct em_perf_state *table; + int min_ps = -1; + int max_ps = -1; + int i; + + if (!pd) + return -EINVAL; + + rcu_read_lock(); + table = em_perf_state_from_pd(pd); + + for (i = 0; i < pd->nr_perf_states; i++) { + if (freq_min_khz == table[i].frequency) + min_ps = i; + if (freq_max_khz == table[i].frequency) + max_ps = i; + } + rcu_read_unlock(); + + /* Only update when both are found and sane */ + if (min_ps < 0 || max_ps < 0 || max_ps < min_ps) + return -EINVAL; + + + /* Guard simultaneous updates and make them atomic */ + mutex_lock(&em_pd_mutex); + pd->min_perf_state = min_ps; + pd->max_perf_state = max_ps; mutex_unlock(&em_pd_mutex); - return ret; + return 0; +} +EXPORT_SYMBOL_GPL(em_update_performance_limits); + +static void rebuild_sd_workfn(struct work_struct *work) +{ + rebuild_sched_domains_energy(); +} + +void em_rebuild_sched_domains(void) +{ + static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); + + /* + * When called from the cpufreq_register_driver() path, the + * cpu_hotplug_lock is already held, so use a work item to + * avoid nested locking in rebuild_sched_domains(). + */ + schedule_work(&rebuild_sd_work); } -EXPORT_SYMBOL_GPL(em_register_perf_domain); |