mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
37f188318e
Set the newly added .register_em() callback to register with the EM after the cpufreq policy is properly initialized. Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
337 lines
8.2 KiB
C
337 lines
8.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* System Control and Power Interface (SCMI) based CPUFreq Interface driver
|
|
*
|
|
* Copyright (C) 2018-2021 ARM Ltd.
|
|
* Sudeep Holla <sudeep.holla@arm.com>
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/clk-provider.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/cpufreq.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/energy_model.h>
|
|
#include <linux/export.h>
|
|
#include <linux/module.h>
|
|
#include <linux/pm_opp.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/scmi_protocol.h>
|
|
#include <linux/types.h>
|
|
|
|
struct scmi_data {
|
|
int domain_id;
|
|
int nr_opp;
|
|
struct device *cpu_dev;
|
|
cpumask_var_t opp_shared_cpus;
|
|
};
|
|
|
|
static struct scmi_protocol_handle *ph;
|
|
static const struct scmi_perf_proto_ops *perf_ops;
|
|
|
|
static unsigned int scmi_cpufreq_get_rate(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
|
|
struct scmi_data *priv = policy->driver_data;
|
|
unsigned long rate;
|
|
int ret;
|
|
|
|
ret = perf_ops->freq_get(ph, priv->domain_id, &rate, false);
|
|
if (ret)
|
|
return 0;
|
|
return rate / 1000;
|
|
}
|
|
|
|
/*
|
|
* perf_ops->freq_set is not a synchronous, the actual OPP change will
|
|
* happen asynchronously and can get notified if the events are
|
|
* subscribed for by the SCMI firmware
|
|
*/
|
|
static int
|
|
scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
|
|
{
|
|
struct scmi_data *priv = policy->driver_data;
|
|
u64 freq = policy->freq_table[index].frequency;
|
|
|
|
return perf_ops->freq_set(ph, priv->domain_id, freq * 1000, false);
|
|
}
|
|
|
|
static unsigned int scmi_cpufreq_fast_switch(struct cpufreq_policy *policy,
|
|
unsigned int target_freq)
|
|
{
|
|
struct scmi_data *priv = policy->driver_data;
|
|
|
|
if (!perf_ops->freq_set(ph, priv->domain_id,
|
|
target_freq * 1000, true))
|
|
return target_freq;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
|
|
{
|
|
int cpu, domain, tdomain;
|
|
struct device *tcpu_dev;
|
|
|
|
domain = perf_ops->device_domain_id(cpu_dev);
|
|
if (domain < 0)
|
|
return domain;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
if (cpu == cpu_dev->id)
|
|
continue;
|
|
|
|
tcpu_dev = get_cpu_device(cpu);
|
|
if (!tcpu_dev)
|
|
continue;
|
|
|
|
tdomain = perf_ops->device_domain_id(tcpu_dev);
|
|
if (tdomain == domain)
|
|
cpumask_set_cpu(cpu, cpumask);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __maybe_unused
|
|
scmi_get_cpu_power(unsigned long *power, unsigned long *KHz,
|
|
struct device *cpu_dev)
|
|
{
|
|
unsigned long Hz;
|
|
int ret, domain;
|
|
|
|
domain = perf_ops->device_domain_id(cpu_dev);
|
|
if (domain < 0)
|
|
return domain;
|
|
|
|
/* Get the power cost of the performance domain. */
|
|
Hz = *KHz * 1000;
|
|
ret = perf_ops->est_power_get(ph, domain, &Hz, power);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* The EM framework specifies the frequency in KHz. */
|
|
*KHz = Hz / 1000;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int scmi_cpufreq_init(struct cpufreq_policy *policy)
|
|
{
|
|
int ret, nr_opp;
|
|
unsigned int latency;
|
|
struct device *cpu_dev;
|
|
struct scmi_data *priv;
|
|
struct cpufreq_frequency_table *freq_table;
|
|
|
|
cpu_dev = get_cpu_device(policy->cpu);
|
|
if (!cpu_dev) {
|
|
pr_err("failed to get cpu%d device\n", policy->cpu);
|
|
return -ENODEV;
|
|
}
|
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
if (!zalloc_cpumask_var(&priv->opp_shared_cpus, GFP_KERNEL)) {
|
|
ret = -ENOMEM;
|
|
goto out_free_priv;
|
|
}
|
|
|
|
/* Obtain CPUs that share SCMI performance controls */
|
|
ret = scmi_get_sharing_cpus(cpu_dev, policy->cpus);
|
|
if (ret) {
|
|
dev_warn(cpu_dev, "failed to get sharing cpumask\n");
|
|
goto out_free_cpumask;
|
|
}
|
|
|
|
/*
|
|
* Obtain CPUs that share performance levels.
|
|
* The OPP 'sharing cpus' info may come from DT through an empty opp
|
|
* table and opp-shared.
|
|
*/
|
|
ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
|
|
if (ret || !cpumask_weight(priv->opp_shared_cpus)) {
|
|
/*
|
|
* Either opp-table is not set or no opp-shared was found.
|
|
* Use the CPU mask from SCMI to designate CPUs sharing an OPP
|
|
* table.
|
|
*/
|
|
cpumask_copy(priv->opp_shared_cpus, policy->cpus);
|
|
}
|
|
|
|
/*
|
|
* A previous CPU may have marked OPPs as shared for a few CPUs, based on
|
|
* what OPP core provided. If the current CPU is part of those few, then
|
|
* there is no need to add OPPs again.
|
|
*/
|
|
nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
|
|
if (nr_opp <= 0) {
|
|
ret = perf_ops->device_opps_add(ph, cpu_dev);
|
|
if (ret) {
|
|
dev_warn(cpu_dev, "failed to add opps to the device\n");
|
|
goto out_free_cpumask;
|
|
}
|
|
|
|
nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
|
|
if (nr_opp <= 0) {
|
|
dev_err(cpu_dev, "%s: No OPPs for this device: %d\n",
|
|
__func__, nr_opp);
|
|
|
|
ret = -ENODEV;
|
|
goto out_free_opp;
|
|
}
|
|
|
|
ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
|
|
if (ret) {
|
|
dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
|
|
__func__, ret);
|
|
|
|
goto out_free_opp;
|
|
}
|
|
|
|
priv->nr_opp = nr_opp;
|
|
}
|
|
|
|
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
|
|
if (ret) {
|
|
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
|
|
goto out_free_opp;
|
|
}
|
|
|
|
priv->cpu_dev = cpu_dev;
|
|
priv->domain_id = perf_ops->device_domain_id(cpu_dev);
|
|
|
|
policy->driver_data = priv;
|
|
policy->freq_table = freq_table;
|
|
|
|
/* SCMI allows DVFS request for any domain from any CPU */
|
|
policy->dvfs_possible_from_any_cpu = true;
|
|
|
|
latency = perf_ops->transition_latency_get(ph, cpu_dev);
|
|
if (!latency)
|
|
latency = CPUFREQ_ETERNAL;
|
|
|
|
policy->cpuinfo.transition_latency = latency;
|
|
|
|
policy->fast_switch_possible =
|
|
perf_ops->fast_switch_possible(ph, cpu_dev);
|
|
|
|
return 0;
|
|
|
|
out_free_opp:
|
|
dev_pm_opp_remove_all_dynamic(cpu_dev);
|
|
|
|
out_free_cpumask:
|
|
free_cpumask_var(priv->opp_shared_cpus);
|
|
|
|
out_free_priv:
|
|
kfree(priv);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int scmi_cpufreq_exit(struct cpufreq_policy *policy)
|
|
{
|
|
struct scmi_data *priv = policy->driver_data;
|
|
|
|
dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
|
|
dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
|
|
free_cpumask_var(priv->opp_shared_cpus);
|
|
kfree(priv);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void scmi_cpufreq_register_em(struct cpufreq_policy *policy)
|
|
{
|
|
struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
|
|
bool power_scale_mw = perf_ops->power_scale_mw_get(ph);
|
|
struct scmi_data *priv = policy->driver_data;
|
|
|
|
/*
|
|
* This callback will be called for each policy, but we don't need to
|
|
* register with EM every time. Despite not being part of the same
|
|
* policy, some CPUs may still share their perf-domains, and a CPU from
|
|
* another policy may already have registered with EM on behalf of CPUs
|
|
* of this policy.
|
|
*/
|
|
if (!priv->nr_opp)
|
|
return;
|
|
|
|
em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp,
|
|
&em_cb, priv->opp_shared_cpus,
|
|
power_scale_mw);
|
|
}
|
|
|
|
static struct cpufreq_driver scmi_cpufreq_driver = {
|
|
.name = "scmi",
|
|
.flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
|
|
CPUFREQ_NEED_INITIAL_FREQ_CHECK |
|
|
CPUFREQ_IS_COOLING_DEV,
|
|
.verify = cpufreq_generic_frequency_table_verify,
|
|
.attr = cpufreq_generic_attr,
|
|
.target_index = scmi_cpufreq_set_target,
|
|
.fast_switch = scmi_cpufreq_fast_switch,
|
|
.get = scmi_cpufreq_get_rate,
|
|
.init = scmi_cpufreq_init,
|
|
.exit = scmi_cpufreq_exit,
|
|
.register_em = scmi_cpufreq_register_em,
|
|
};
|
|
|
|
static int scmi_cpufreq_probe(struct scmi_device *sdev)
|
|
{
|
|
int ret;
|
|
struct device *dev = &sdev->dev;
|
|
const struct scmi_handle *handle;
|
|
|
|
handle = sdev->handle;
|
|
|
|
if (!handle)
|
|
return -ENODEV;
|
|
|
|
perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph);
|
|
if (IS_ERR(perf_ops))
|
|
return PTR_ERR(perf_ops);
|
|
|
|
#ifdef CONFIG_COMMON_CLK
|
|
/* dummy clock provider as needed by OPP if clocks property is used */
|
|
if (of_find_property(dev->of_node, "#clock-cells", NULL))
|
|
devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL);
|
|
#endif
|
|
|
|
ret = cpufreq_register_driver(&scmi_cpufreq_driver);
|
|
if (ret) {
|
|
dev_err(dev, "%s: registering cpufreq failed, err: %d\n",
|
|
__func__, ret);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void scmi_cpufreq_remove(struct scmi_device *sdev)
|
|
{
|
|
cpufreq_unregister_driver(&scmi_cpufreq_driver);
|
|
}
|
|
|
|
static const struct scmi_device_id scmi_id_table[] = {
|
|
{ SCMI_PROTOCOL_PERF, "cpufreq" },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(scmi, scmi_id_table);
|
|
|
|
static struct scmi_driver scmi_cpufreq_drv = {
|
|
.name = "scmi-cpufreq",
|
|
.probe = scmi_cpufreq_probe,
|
|
.remove = scmi_cpufreq_remove,
|
|
.id_table = scmi_id_table,
|
|
};
|
|
module_scmi_driver(scmi_cpufreq_drv);
|
|
|
|
MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
|
|
MODULE_DESCRIPTION("ARM SCMI CPUFreq interface driver");
|
|
MODULE_LICENSE("GPL v2");
|