diff options
Diffstat (limited to 'kernel/power/energy_model.c')
| -rw-r--r-- | kernel/power/energy_model.c | 1046 |
1 files changed, 1046 insertions, 0 deletions
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c new file mode 100644 index 000000000000..11af9f64aa82 --- /dev/null +++ b/kernel/power/energy_model.c @@ -0,0 +1,1046 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Energy Model of devices + * + * 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> + +#include "em_netlink.h" + +/* + * Mutex serializing the registrations of performance domains and letting + * callbacks defined by drivers sleep. + */ +static DEFINE_MUTEX(em_pd_mutex); + +/* + * Manage performance domains with IDs. One can iterate the performance domains + * through the list and pick one with their associated ID. The mutex serializes + * the list access. When holding em_pd_list_mutex, em_pd_mutex should not be + * taken to avoid potential deadlock. + */ +static DEFINE_IDA(em_pd_ida); +static LIST_HEAD(em_pd_list); +static DEFINE_MUTEX(em_pd_list_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; + +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]; + + 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(); + + snprintf(name, sizeof(name), "ps:%lu", freq); + + /* Create per-ps directory */ + d = debugfs_create_dir(name, pd); + 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) +{ + seq_printf(s, "%*pbl\n", cpumask_pr_args(to_cpumask(s->private))); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); + +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 int em_debug_id_show(struct seq_file *s, void *unused) +{ + struct em_perf_domain *pd = s->private; + + seq_printf(s, "%d\n", pd->id); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(em_debug_id); + +static void em_debug_create_pd(struct device *dev) +{ + struct em_dbg_info *em_dbg; + struct dentry *d; + int i; + + /* Create the directory of the performance domain */ + 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); + + debugfs_create_file("id", 0444, d, dev->em_pd, &em_debug_id_fops); + + em_dbg = devm_kcalloc(dev, dev->em_pd->nr_perf_states, + sizeof(*em_dbg), GFP_KERNEL); + if (!em_dbg) + return; + + /* 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); + +} + +static void em_debug_remove_pd(struct device *dev) +{ + debugfs_lookup_and_remove(dev_name(dev), rootdir); +} + +static int __init em_debug_init(void) +{ + /* Create /sys/kernel/debug/energy_model directory */ + rootdir = debugfs_create_dir("energy_model", NULL); + + return 0; +} +fs_initcall(em_debug_init); +#else /* CONFIG_DEBUG_FS */ +static void em_debug_create_pd(struct device *dev) {} +static void em_debug_remove_pd(struct device *dev) {} +#endif + +static void em_release_table_kref(struct kref *kref) +{ + /* It was the last owner of this table so we can free */ + kfree_rcu(container_of(kref, struct em_perf_table, kref), 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 *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 *em_table_alloc(struct em_perf_domain *pd) +{ + struct em_perf_table *table; + int table_size; + + table_size = sizeof(struct em_perf_state) * pd->nr_perf_states; + + table = kzalloc(sizeof(*table) + table_size, GFP_KERNEL); + if (!table) + 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, + const struct em_data_callback *cb, int nr_states, + unsigned long flags) +{ + unsigned long prev_cost = ULONG_MAX; + int i, ret; + + /* This is needed only for CPUs and EAS skip other devices */ + if (!_is_cpu_device(dev)) + return 0; + + /* 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 *new_table) +{ + struct em_perf_table *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 = rcu_dereference_protected(pd->em_table, + lockdep_is_held(&em_pd_mutex)); + 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); + + em_notify_pd_updated(pd); + return 0; +} +EXPORT_SYMBOL_GPL(em_dev_update_perf_domain); + +static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, + struct em_perf_state *table, + const 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 performance state of 'dev' above 'freq' and updates + * 'power' and 'freq' accordingly. + */ + ret = cb->active_power(dev, &power, &freq); + if (ret) { + dev_err(dev, "EM: invalid perf. state: %d\n", + ret); + return -EINVAL; + } + + /* + * We expect the driver callback to increase the frequency for + * higher performance states. + */ + if (freq <= prev_freq) { + dev_err(dev, "EM: non-increasing freq: %lu\n", + freq); + return -EINVAL; + } + + /* + * The power returned by active_state() is expected to be + * positive and be in range. + */ + 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; + } + + 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, + const struct em_data_callback *cb, + const cpumask_t *cpus, + unsigned long flags) +{ + struct em_perf_table *em_table; + struct em_perf_domain *pd; + struct device *cpu_dev; + int cpu, ret, num_cpus, id; + + 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->nr_perf_states = nr_states; + + INIT_LIST_HEAD(&pd->node); + + id = ida_alloc(&em_pd_ida, GFP_KERNEL); + if (id < 0) + return -ENOMEM; + pd->id = id; + + em_table = em_table_alloc(pd); + if (!em_table) + goto free_pd; + + ret = em_create_perf_table(dev, pd, em_table->state, cb, flags); + if (ret) + goto free_pd_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); + ida_free(&em_pd_ida, id); + 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 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 + * + * Returns the performance domain to which @cpu belongs, or NULL if it doesn't + * exist. + */ +struct em_perf_domain *em_cpu_get(int 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_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_dev_register_perf_domain(struct device *dev, unsigned int nr_states, + const struct em_data_callback *cb, + const cpumask_t *cpus, bool microwatts) +{ + int ret = em_dev_register_pd_no_update(dev, nr_states, cb, cpus, microwatts); + + if (_is_cpu_device(dev)) + em_check_capacity_update(); + + return ret; +} +EXPORT_SYMBOL_GPL(em_dev_register_perf_domain); + +/** + * em_dev_register_pd_no_update() - Register a perf domain for a device + * @dev : Device to register the PD for + * @nr_states : Number of performance states in the new PD + * @cb : Callback functions for populating the energy model + * @cpus : CPUs to include in the new PD (mandatory if @dev is a CPU device) + * @microwatts : Whether or not the power values in the EM will be in uW + * + * Like em_dev_register_perf_domain(), but does not trigger a CPU capacity + * update after registering the PD, even if @dev is a CPU device. + */ +int em_dev_register_pd_no_update(struct device *dev, unsigned int nr_states, + const struct em_data_callback *cb, + const cpumask_t *cpus, bool microwatts) +{ + struct em_perf_table *em_table; + unsigned long cap, prev_cap = 0; + unsigned long flags = 0; + int cpu, ret; + + if (!dev || !nr_states || !cb) + return -EINVAL; + + /* + * Use a mutex to serialize the registration of performance domains and + * let the driver-defined callback functions sleep. + */ + mutex_lock(&em_pd_mutex); + + if (dev->em_pd) { + ret = -EEXIST; + goto unlock; + } + + if (_is_cpu_device(dev)) { + if (!cpus) { + dev_err(dev, "EM: invalid CPU mask\n"); + ret = -EINVAL; + goto unlock; + } + + 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; + } + } + + 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; + } + + 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_table = rcu_dereference_protected(dev->em_pd->em_table, + lockdep_is_held(&em_pd_mutex)); + em_cpufreq_update_efficiencies(dev, em_table->state); + + em_debug_create_pd(dev); + dev_info(dev, "EM: created perf domain\n"); + +unlock: + mutex_unlock(&em_pd_mutex); + if (ret) + return ret; + + mutex_lock(&em_pd_list_mutex); + list_add_tail(&dev->em_pd->node, &em_pd_list); + mutex_unlock(&em_pd_list_mutex); + + em_notify_pd_created(dev->em_pd); + + return 0; +} +EXPORT_SYMBOL_GPL(em_dev_register_pd_no_update); + +/** + * 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; + + mutex_lock(&em_pd_list_mutex); + list_del_init(&dev->em_pd->node); + mutex_unlock(&em_pd_list_mutex); + + em_notify_pd_deleted(dev->em_pd); + + /* + * 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(rcu_dereference_protected(dev->em_pd->em_table, + lockdep_is_held(&em_pd_mutex))); + + ida_free(&em_pd_ida, dev->em_pd->id); + + 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 *em_table_dup(struct em_perf_domain *pd) +{ + struct em_perf_table *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 *em_table) +{ + int ret; + + if (!em_is_artificial(pd)) { + 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(unsigned int cpu, struct device *dev, + struct em_perf_domain *pd) +{ + unsigned long cpu_capacity = arch_scale_cpu_capacity(cpu); + struct em_perf_table *em_table; + struct em_perf_state *table; + unsigned long em_max_perf; + + rcu_read_lock(); + table = em_perf_state_from_pd(pd); + em_max_perf = table[pd->nr_perf_states - 1].performance; + rcu_read_unlock(); + + if (em_max_perf == cpu_capacity) + return; + + pr_debug("updating cpu%d cpu_cap=%lu old capacity=%lu\n", cpu, + cpu_capacity, em_max_perf); + + 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); +} + +/** + * em_adjust_cpu_capacity() - Adjust the EM for a CPU after a capacity update. + * @cpu: Target CPU. + * + * Adjust the existing EM for @cpu after a capacity update under the assumption + * that the capacity has been updated in the same way for all of the CPUs in + * the same perf domain. + */ +void em_adjust_cpu_capacity(unsigned int cpu) +{ + struct device *dev = get_cpu_device(cpu); + struct em_perf_domain *pd; + + pd = em_pd_get(dev); + if (pd) + em_adjust_new_capacity(cpu, dev, pd); +} + +static void em_check_capacity_update(void) +{ + cpumask_var_t cpu_done_mask; + int cpu, failed_cpus = 0; + + 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; + struct em_perf_domain *pd; + struct device *dev; + + if (cpumask_test_cpu(cpu, cpu_done_mask)) + continue; + + policy = cpufreq_cpu_get(cpu); + if (!policy) { + failed_cpus++; + continue; + } + cpufreq_cpu_put(policy); + + dev = get_cpu_device(cpu); + pd = em_pd_get(dev); + if (!pd || em_is_artificial(pd)) + continue; + + cpumask_or(cpu_done_mask, cpu_done_mask, + em_span_cpus(pd)); + + em_adjust_new_capacity(cpu, dev, pd); + } + + if (failed_cpus) + schedule_delayed_work(&em_update_work, msecs_to_jiffies(1000)); + + 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 *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 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); +} + +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_NET) +int for_each_em_perf_domain(int (*cb)(struct em_perf_domain*, void *), + void *data) +{ + struct em_perf_domain *pd; + + lockdep_assert_not_held(&em_pd_mutex); + guard(mutex)(&em_pd_list_mutex); + + list_for_each_entry(pd, &em_pd_list, node) { + int ret; + + ret = cb(pd, data); + if (ret) + return ret; + } + + return 0; +} + +struct em_perf_domain *em_perf_domain_get_by_id(int id) +{ + struct em_perf_domain *pd; + + lockdep_assert_not_held(&em_pd_mutex); + guard(mutex)(&em_pd_list_mutex); + + list_for_each_entry(pd, &em_pd_list, node) { + if (pd->id == id) + return pd; + } + + return NULL; +} +#endif |