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-rw-r--r--kernel/power/energy_model.c891
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);