diff options
Diffstat (limited to 'drivers/hwmon/amd_energy.c')
| -rw-r--r-- | drivers/hwmon/amd_energy.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/drivers/hwmon/amd_energy.c b/drivers/hwmon/amd_energy.c new file mode 100644 index 000000000..f22154863 --- /dev/null +++ b/drivers/hwmon/amd_energy.c @@ -0,0 +1,377 @@ +// 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"); |