blob: d06597303d5aeb79755b0ad285b4a5dd89df936c [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Advanced Micro Devices, Inc.
*/
#include <asm/cpu_device_id.h>
#include <linux/bits.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/processor.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/topology.h>
#include <linux/types.h>
#define DRVNAME "amd_energy"
#define ENERGY_PWR_UNIT_MSR 0xC0010299
#define ENERGY_CORE_MSR 0xC001029A
#define ENERGY_PKG_MSR 0xC001029B
#define AMD_ENERGY_UNIT_MASK 0x01F00
#define AMD_ENERGY_MASK 0xFFFFFFFF
struct sensor_accumulator {
u64 energy_ctr;
u64 prev_value;
};
struct amd_energy_data {
struct hwmon_channel_info energy_info;
const struct hwmon_channel_info *info[2];
struct hwmon_chip_info chip;
struct task_struct *wrap_accumulate;
/* Lock around the accumulator */
struct mutex lock;
/* An accumulator for each core and socket */
struct sensor_accumulator *accums;
unsigned int timeout_ms;
/* Energy Status Units */
int energy_units;
int nr_cpus;
int nr_socks;
int core_id;
char (*label)[10];
};
static int amd_energy_read_labels(struct device *dev,
enum hwmon_sensor_types type,
u32 attr, int channel,
const char **str)
{
struct amd_energy_data *data = dev_get_drvdata(dev);
*str = data->label[channel];
return 0;
}
static void get_energy_units(struct amd_energy_data *data)
{
u64 rapl_units;
rdmsrl_safe(ENERGY_PWR_UNIT_MSR, &rapl_units);
data->energy_units = (rapl_units & AMD_ENERGY_UNIT_MASK) >> 8;
}
static void accumulate_delta(struct amd_energy_data *data,
int channel, int cpu, u32 reg)
{
struct sensor_accumulator *accum;
u64 input;
mutex_lock(&data->lock);
rdmsrl_safe_on_cpu(cpu, reg, &input);
input &= AMD_ENERGY_MASK;
accum = &data->accums[channel];
if (input >= accum->prev_value)
accum->energy_ctr +=
input - accum->prev_value;
else
accum->energy_ctr += UINT_MAX -
accum->prev_value + input;
accum->prev_value = input;
mutex_unlock(&data->lock);
}
static void read_accumulate(struct amd_energy_data *data)
{
int sock, scpu, cpu;
for (sock = 0; sock < data->nr_socks; sock++) {
scpu = cpumask_first_and(cpu_online_mask,
cpumask_of_node(sock));
accumulate_delta(data, data->nr_cpus + sock,
scpu, ENERGY_PKG_MSR);
}
if (data->core_id >= data->nr_cpus)
data->core_id = 0;
cpu = data->core_id;
if (cpu_online(cpu))
accumulate_delta(data, cpu, cpu, ENERGY_CORE_MSR);
data->core_id++;
}
static void amd_add_delta(struct amd_energy_data *data, int ch,
int cpu, long *val, u32 reg)
{
struct sensor_accumulator *accum;
u64 input;
mutex_lock(&data->lock);
rdmsrl_safe_on_cpu(cpu, reg, &input);
input &= AMD_ENERGY_MASK;
accum = &data->accums[ch];
if (input >= accum->prev_value)
input += accum->energy_ctr -
accum->prev_value;
else
input += UINT_MAX - accum->prev_value +
accum->energy_ctr;
/* Energy consumed = (1/(2^ESU) * RAW * 1000000UL) μJoules */
*val = div64_ul(input * 1000000UL, BIT(data->energy_units));
mutex_unlock(&data->lock);
}
static int amd_energy_read(struct device *dev,
enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct amd_energy_data *data = dev_get_drvdata(dev);
u32 reg;
int cpu;
if (channel >= data->nr_cpus) {
cpu = cpumask_first_and(cpu_online_mask,
cpumask_of_node
(channel - data->nr_cpus));
reg = ENERGY_PKG_MSR;
} else {
cpu = channel;
if (!cpu_online(cpu))
return -ENODEV;
reg = ENERGY_CORE_MSR;
}
amd_add_delta(data, channel, cpu, val, reg);
return 0;
}
static umode_t amd_energy_is_visible(const void *_data,
enum hwmon_sensor_types type,
u32 attr, int channel)
{
return 0444;
}
static int energy_accumulator(void *p)
{
struct amd_energy_data *data = (struct amd_energy_data *)p;
unsigned int timeout = data->timeout_ms;
while (!kthread_should_stop()) {
/*
* Ignoring the conditions such as
* cpu being offline or rdmsr failure
*/
read_accumulate(data);
set_current_state(TASK_INTERRUPTIBLE);
if (kthread_should_stop())
break;
schedule_timeout(msecs_to_jiffies(timeout));
}
return 0;
}
static const struct hwmon_ops amd_energy_ops = {
.is_visible = amd_energy_is_visible,
.read = amd_energy_read,
.read_string = amd_energy_read_labels,
};
static int amd_create_sensor(struct device *dev,
struct amd_energy_data *data,
enum hwmon_sensor_types type, u32 config)
{
struct hwmon_channel_info *info = &data->energy_info;
struct sensor_accumulator *accums;
int i, num_siblings, cpus, sockets;
u32 *s_config;
char (*label_l)[10];
/* Identify the number of siblings per core */
num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;
sockets = num_possible_nodes();
/*
* Energy counter register is accessed at core level.
* Hence, filterout the siblings.
*/
cpus = num_present_cpus() / num_siblings;
s_config = devm_kcalloc(dev, cpus + sockets,
sizeof(u32), GFP_KERNEL);
if (!s_config)
return -ENOMEM;
accums = devm_kcalloc(dev, cpus + sockets,
sizeof(struct sensor_accumulator),
GFP_KERNEL);
if (!accums)
return -ENOMEM;
label_l = devm_kcalloc(dev, cpus + sockets,
sizeof(*label_l), GFP_KERNEL);
if (!label_l)
return -ENOMEM;
info->type = type;
info->config = s_config;
data->nr_cpus = cpus;
data->nr_socks = sockets;
data->accums = accums;
data->label = label_l;
for (i = 0; i < cpus + sockets; i++) {
s_config[i] = config;
if (i < cpus)
scnprintf(label_l[i], 10, "Ecore%03u", i);
else
scnprintf(label_l[i], 10, "Esocket%u", (i - cpus));
}
return 0;
}
static int amd_energy_probe(struct platform_device *pdev)
{
struct device *hwmon_dev;
struct amd_energy_data *data;
struct device *dev = &pdev->dev;
int ret;
data = devm_kzalloc(dev,
sizeof(struct amd_energy_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->chip.ops = &amd_energy_ops;
data->chip.info = data->info;
dev_set_drvdata(dev, data);
/* Populate per-core energy reporting */
data->info[0] = &data->energy_info;
ret = amd_create_sensor(dev, data, hwmon_energy,
HWMON_E_INPUT | HWMON_E_LABEL);
if (ret)
return ret;
mutex_init(&data->lock);
get_energy_units(data);
hwmon_dev = devm_hwmon_device_register_with_info(dev, DRVNAME,
data,
&data->chip,
NULL);
if (IS_ERR(hwmon_dev))
return PTR_ERR(hwmon_dev);
/*
* On a system with peak wattage of 250W
* timeout = 2 ^ 32 / 2 ^ energy_units / 250 secs
*/
data->timeout_ms = 1000 *
BIT(min(28, 31 - data->energy_units)) / 250;
data->wrap_accumulate = kthread_run(energy_accumulator, data,
"%s", dev_name(hwmon_dev));
return PTR_ERR_OR_ZERO(data->wrap_accumulate);
}
static int amd_energy_remove(struct platform_device *pdev)
{
struct amd_energy_data *data = dev_get_drvdata(&pdev->dev);
if (data && data->wrap_accumulate)
kthread_stop(data->wrap_accumulate);
return 0;
}
static const struct platform_device_id amd_energy_ids[] = {
{ .name = DRVNAME, },
{}
};
MODULE_DEVICE_TABLE(platform, amd_energy_ids);
static struct platform_driver amd_energy_driver = {
.probe = amd_energy_probe,
.remove = amd_energy_remove,
.id_table = amd_energy_ids,
.driver = {
.name = DRVNAME,
},
};
static struct platform_device *amd_energy_platdev;
static const struct x86_cpu_id cpu_ids[] __initconst = {
X86_MATCH_VENDOR_FAM_MODEL(AMD, 0x17, 0x31, NULL),
{}
};
MODULE_DEVICE_TABLE(x86cpu, cpu_ids);
static int __init amd_energy_init(void)
{
int ret;
if (!x86_match_cpu(cpu_ids))
return -ENODEV;
ret = platform_driver_register(&amd_energy_driver);
if (ret)
return ret;
amd_energy_platdev = platform_device_alloc(DRVNAME, 0);
if (!amd_energy_platdev) {
platform_driver_unregister(&amd_energy_driver);
return -ENOMEM;
}
ret = platform_device_add(amd_energy_platdev);
if (ret) {
platform_device_put(amd_energy_platdev);
platform_driver_unregister(&amd_energy_driver);
return ret;
}
return ret;
}
static void __exit amd_energy_exit(void)
{
platform_device_unregister(amd_energy_platdev);
platform_driver_unregister(&amd_energy_driver);
}
module_init(amd_energy_init);
module_exit(amd_energy_exit);
MODULE_DESCRIPTION("Driver for AMD Energy reporting from RAPL MSR via HWMON interface");
MODULE_AUTHOR("Naveen Krishna Chatradhi <nchatrad@amd.com>");
MODULE_LICENSE("GPL");