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- // 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 0440;
- }
- 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 + 1,
- 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));
- }
- s_config[i] = 0;
- 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");
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