linux-stable/drivers/cpufreq/scmi-cpufreq.c
Sibi Sankar a8e949d41c cpufreq: scmi: Enable boost support
Certain platforms host a number of higher OPPs that are exclusive to
CPUs within specific CPUfreq policies and not all CPUs within that
CPUfreq policy are able to achieve those higher OPPs due to power
constraints. These OPPs are marked as turbo in the freq_table and in
the presence of such OPPs, let's enable boost by default.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2024-03-15 11:19:27 +05:30

418 lines
10 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>
#include <linux/units.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 struct cpufreq_driver scmi_cpufreq_driver;
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_cpu_domain_id(struct device *cpu_dev)
{
struct device_node *np = cpu_dev->of_node;
struct of_phandle_args domain_id;
int index;
if (of_parse_phandle_with_args(np, "clocks", "#clock-cells", 0,
&domain_id)) {
/* Find the corresponding index for power-domain "perf". */
index = of_property_match_string(np, "power-domain-names",
"perf");
if (index < 0)
return -EINVAL;
if (of_parse_phandle_with_args(np, "power-domains",
"#power-domain-cells", index,
&domain_id))
return -EINVAL;
}
return domain_id.args[0];
}
static int
scmi_get_sharing_cpus(struct device *cpu_dev, int domain,
struct cpumask *cpumask)
{
int cpu, tdomain;
struct device *tcpu_dev;
for_each_possible_cpu(cpu) {
if (cpu == cpu_dev->id)
continue;
tcpu_dev = get_cpu_device(cpu);
if (!tcpu_dev)
continue;
tdomain = scmi_cpu_domain_id(tcpu_dev);
if (tdomain == domain)
cpumask_set_cpu(cpu, cpumask);
}
return 0;
}
static int __maybe_unused
scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
unsigned long *KHz)
{
enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
unsigned long Hz;
int ret, domain;
domain = scmi_cpu_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;
/* Convert the power to uW if it is mW (ignore bogoW) */
if (power_scale == SCMI_POWER_MILLIWATTS)
*power *= MICROWATT_PER_MILLIWATT;
/* The EM framework specifies the frequency in KHz. */
*KHz = Hz / 1000;
return 0;
}
static int
scmi_get_rate_limit(u32 domain, bool has_fast_switch)
{
int ret, rate_limit;
if (has_fast_switch) {
/*
* Fast channels are used whenever available,
* so use their rate_limit value if populated.
*/
ret = perf_ops->fast_switch_rate_limit(ph, domain,
&rate_limit);
if (!ret && rate_limit)
return rate_limit;
}
ret = perf_ops->rate_limit_get(ph, domain, &rate_limit);
if (ret)
return 0;
return rate_limit;
}
static struct freq_attr *scmi_cpufreq_hw_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
NULL,
};
static int scmi_cpufreq_init(struct cpufreq_policy *policy)
{
int ret, nr_opp, domain;
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;
}
domain = scmi_cpu_domain_id(cpu_dev);
if (domain < 0)
return domain;
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, domain, 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_empty(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, domain);
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 = domain;
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, domain);
if (!latency)
latency = CPUFREQ_ETERNAL;
policy->cpuinfo.transition_latency = latency;
policy->fast_switch_possible =
perf_ops->fast_switch_possible(ph, domain);
policy->transition_delay_us =
scmi_get_rate_limit(domain, policy->fast_switch_possible);
if (policy_has_boost_freq(policy)) {
ret = cpufreq_enable_boost_support();
if (ret) {
dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
goto out_free_opp;
} else {
scmi_cpufreq_hw_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
scmi_cpufreq_driver.boost_enabled = true;
}
}
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);
enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
struct scmi_data *priv = policy->driver_data;
bool em_power_scale = false;
/*
* 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;
if (power_scale == SCMI_POWER_MILLIWATTS
|| power_scale == SCMI_POWER_MICROWATTS)
em_power_scale = true;
em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp,
&em_cb, priv->opp_shared_cpus,
em_power_scale);
}
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 = scmi_cpufreq_hw_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_property_present(dev->of_node, "#clock-cells")) {
ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL);
if (ret)
return dev_err_probe(dev, ret, "%s: registering clock provider failed\n", __func__);
}
#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");