From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/kernel/power/energy_model.c | 348 +++++++++++++++++++++++++++++++++++++--------------------
1 files changed, 226 insertions(+), 122 deletions(-)
diff --git a/kernel/kernel/power/energy_model.c b/kernel/kernel/power/energy_model.c
index b72f1af..c2c858c 100644
--- a/kernel/kernel/power/energy_model.c
+++ b/kernel/kernel/power/energy_model.c
@@ -1,9 +1,10 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Energy Model of CPUs
+ * Energy Model of devices
*
- * Copyright (c) 2018, Arm ltd.
+ * Copyright (c) 2018-2020, Arm ltd.
* Written by: Quentin Perret, Arm ltd.
+ * Improvements provided by: Lukasz Luba, Arm ltd.
*/
#define pr_fmt(fmt) "energy_model: " fmt
@@ -15,30 +16,32 @@
#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 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)
+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)
@@ -49,22 +52,40 @@
}
DEFINE_SHOW_ATTRIBUTE(em_debug_cpus);
-static void em_debug_create_pd(struct em_perf_domain *pd, int cpu)
+static int em_debug_units_show(struct seq_file *s, void *unused)
+{
+ struct em_perf_domain *pd = s->private;
+ char *units = pd->milliwatts ? "milliWatts" : "bogoWatts";
+
+ seq_printf(s, "%s\n", units);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(em_debug_units);
+
+static void em_debug_create_pd(struct device *dev)
{
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);
- debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops);
+ if (_is_cpu_device(dev))
+ debugfs_create_file("cpus", 0444, d, dev->em_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);
+ debugfs_create_file("units", 0444, d, dev->em_pd, &em_debug_units_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->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)
@@ -74,140 +95,189 @@
return 0;
}
-#ifdef CONFIG_ROCKCHIP_THUNDER_BOOT
-core_initcall_sync(em_debug_init);
-#else
-core_initcall(em_debug_init);
-#endif
+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 int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
+ int nr_states, struct em_data_callback *cb)
{
- 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;
+ unsigned long power, freq, prev_freq = 0, prev_cost = ULONG_MAX;
+ struct em_perf_state *table;
+ int i, ret;
u64 fmax;
-
- if (!cb->active_power)
- return NULL;
-
- pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL);
- if (!pd)
- return NULL;
table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL);
if (!table)
- goto free_pd;
+ return -ENOMEM;
- /* 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 'dev' 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 cap. state: %d\n", cpu, ret);
- goto free_cs_table;
+ dev_err(dev, "EM: invalid perf. state: %d\n",
+ 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;
+ dev_err(dev, "EM: non-increasing freq: %lu\n",
+ freq);
+ goto free_ps_table;
}
/*
* 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) {
- 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);
+ goto free_ps_table;
}
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. */
+ /* 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,
+ for (i = nr_states - 1; i >= 0; i--) {
+ unsigned long power_res = em_scale_power(table[i].power);
+
+ table[i].cost = div64_u64(fmax * power_res,
table[i].frequency);
+ if (table[i].cost >= prev_cost) {
+ dev_dbg(dev, "EM: OPP:%lu is inefficient\n",
+ table[i].frequency);
+ } else {
+ prev_cost = table[i].cost;
+ }
}
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);
+ return 0;
- return pd;
-
-free_cs_table:
+free_ps_table:
kfree(table);
-free_pd:
- kfree(pd);
-
- return NULL;
+ return -EINVAL;
}
+
+static int em_create_pd(struct device *dev, int nr_states,
+ struct em_data_callback *cb, cpumask_t *cpus)
+{
+ struct em_perf_domain *pd;
+ struct device *cpu_dev;
+ int cpu, ret;
+
+ if (_is_cpu_device(dev)) {
+ 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;
+ }
+
+ ret = em_create_perf_table(dev, pd, nr_states, cb);
+ if (ret) {
+ kfree(pd);
+ return ret;
+ }
+
+ 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;
+}
+
+/**
+ * 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
*
- * 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.
+ * @milliwatts : Flag indicating that the power values are in milliWatts or
+ * in some other scale. It must be set properly.
*
* Create Energy Model tables for a performance domain using the callbacks
* defined in cb.
+ *
+ * The @milliwatts is important to set with correct value. Some kernel
+ * 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 milliwatts)
{
unsigned long cap, prev_cap = 0;
- struct em_perf_domain *pd;
- int cpu, ret = 0;
+ int cpu, ret;
- if (!span || !nr_states || !cb)
+ if (!dev || !nr_states || !cb)
return -EINVAL;
/*
@@ -216,47 +286,81 @@
*/
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;
- }
-
- /*
- * All CPUs of a domain must have the same micro-architecture
- * since they all share the same table.
- */
- cap = arch_scale_cpu_capacity(NULL, cpu);
- if (prev_cap && prev_cap != cap) {
- pr_err("CPUs of %*pbl must have the same capacity\n",
- cpumask_pr_args(span));
- 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) {
- ret = -EINVAL;
+ if (dev->em_pd) {
+ ret = -EEXIST;
goto unlock;
}
- for_each_cpu(cpu, span) {
- /*
- * 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.
- */
- smp_store_release(per_cpu_ptr(&em_data, cpu), pd);
+ 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;
+ }
}
- pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span));
+ ret = em_create_pd(dev, nr_states, cb, cpus);
+ if (ret)
+ goto unlock;
+
+ dev->em_pd->milliwatts = milliwatts;
+
+ em_debug_create_pd(dev);
+ dev_info(dev, "EM: created perf domain\n");
+
unlock:
mutex_unlock(&em_pd_mutex);
-
return ret;
}
-EXPORT_SYMBOL_GPL(em_register_perf_domain);
+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);
+
+ kfree(dev->em_pd->table);
+ kfree(dev->em_pd);
+ dev->em_pd = NULL;
+ mutex_unlock(&em_pd_mutex);
+}
+EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain);
--
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