drivers/hwmon/amd_energy.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 /*
   4  * Copyright (C) 2020 Advanced Micro Devices, Inc.
   5  */
   6 #include <asm/cpu_device_id.h>
   7
   8 #include <linux/bits.h>
   9 #include <linux/cpu.h>
  10 #include <linux/cpumask.h>
  11 #include <linux/delay.h>
  12 #include <linux/device.h>
  13 #include <linux/hwmon.h>
  14 #include <linux/kernel.h>
  15 #include <linux/kthread.h>
  16 #include <linux/list.h>
  17 #include <linux/module.h>
  18 #include <linux/mutex.h>
  19 #include <linux/processor.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/sched.h>
  22 #include <linux/slab.h>
  23 #include <linux/topology.h>
  24 #include <linux/types.h>
  25
  26 #define DRVNAME                 "amd_energy"
  27
  28 #define ENERGY_PWR_UNIT_MSR     0xC0010299
  29 #define ENERGY_CORE_MSR         0xC001029A
  30 #define ENERGY_PKG_MSR          0xC001029B
  31
  32 #define AMD_ENERGY_UNIT_MASK    0x01F00
  33 #define AMD_ENERGY_MASK         0xFFFFFFFF
  34
  35 struct sensor_accumulator {
  36         u64 energy_ctr;
  37         u64 prev_value;
  38 };
  39
  40 struct amd_energy_data {
  41         struct hwmon_channel_info energy_info;
  42         const struct hwmon_channel_info *info[2];
  43         struct hwmon_chip_info chip;
  44         struct task_struct *wrap_accumulate;
  45         /* Lock around the accumulator */
  46         struct mutex lock;
  47         /* An accumulator for each core and socket */
  48         struct sensor_accumulator *accums;
  49         unsigned int timeout_ms;
  50         /* Energy Status Units */
  51         int energy_units;
  52         int nr_cpus;
  53         int nr_socks;
  54         int core_id;
  55         char (*label)[10];
  56 };
  57
  58 static int amd_energy_read_labels(struct device *dev,
  59                                   enum hwmon_sensor_types type,
  60                                   u32 attr, int channel,
  61                                   const char **str)
  62 {
  63         struct amd_energy_data *data = dev_get_drvdata(dev);
  64
  65         *str = data->label[channel];
  66         return 0;
  67 }
  68
  69 static void get_energy_units(struct amd_energy_data *data)
  70 {
  71         u64 rapl_units;
  72
  73         rdmsrl_safe(ENERGY_PWR_UNIT_MSR, &rapl_units);
  74         data->energy_units = (rapl_units & AMD_ENERGY_UNIT_MASK) >> 8;
  75 }
  76
  77 static void accumulate_delta(struct amd_energy_data *data,
  78                              int channel, int cpu, u32 reg)
  79 {
  80         struct sensor_accumulator *accum;
  81         u64 input;
  82
  83         mutex_lock(&data->lock);
  84         rdmsrl_safe_on_cpu(cpu, reg, &input);
  85         input &= AMD_ENERGY_MASK;
  86
  87         accum = &data->accums[channel];
  88         if (input >= accum->prev_value)
  89                 accum->energy_ctr +=
  90                         input - accum->prev_value;
  91         else
  92                 accum->energy_ctr += UINT_MAX -
  93                         accum->prev_value + input;
  94
  95         accum->prev_value = input;
  96         mutex_unlock(&data->lock);
  97 }
  98
  99 static void read_accumulate(struct amd_energy_data *data)
 100 {
 101         int sock, scpu, cpu;
 102
 103         for (sock = 0; sock < data->nr_socks; sock++) {
 104                 scpu = cpumask_first_and(cpu_online_mask,
 105                                          cpumask_of_node(sock));
 106
 107                 accumulate_delta(data, data->nr_cpus + sock,
 108                                  scpu, ENERGY_PKG_MSR);
 109         }
 110
 111         if (data->core_id >= data->nr_cpus)
 112                 data->core_id = 0;
 113
 114         cpu = data->core_id;
 115         if (cpu_online(cpu))
 116                 accumulate_delta(data, cpu, cpu, ENERGY_CORE_MSR);
 117
 118         data->core_id++;
 119 }
 120
 121 static void amd_add_delta(struct amd_energy_data *data, int ch,
 122                           int cpu, long *val, u32 reg)
 123 {
 124         struct sensor_accumulator *accum;
 125         u64 input;
 126
 127         mutex_lock(&data->lock);
 128         rdmsrl_safe_on_cpu(cpu, reg, &input);
 129         input &= AMD_ENERGY_MASK;
 130
 131         accum = &data->accums[ch];
 132         if (input >= accum->prev_value)
 133                 input += accum->energy_ctr -
 134                                 accum->prev_value;
 135         else
 136                 input += UINT_MAX - accum->prev_value +
 137                                 accum->energy_ctr;
 138
 139         /* Energy consumed = (1/(2^ESU) * RAW * 1000000UL) μJoules */
 140         *val = div64_ul(input * 1000000UL, BIT(data->energy_units));
 141
 142         mutex_unlock(&data->lock);
 143 }
 144
 145 static int amd_energy_read(struct device *dev,
 146                            enum hwmon_sensor_types type,
 147                            u32 attr, int channel, long *val)
 148 {
 149         struct amd_energy_data *data = dev_get_drvdata(dev);
 150         u32 reg;
 151         int cpu;
 152
 153         if (channel >= data->nr_cpus) {
 154                 cpu = cpumask_first_and(cpu_online_mask,
 155                                         cpumask_of_node
 156                                         (channel - data->nr_cpus));
 157                 reg = ENERGY_PKG_MSR;
 158         } else {
 159                 cpu = channel;
 160                 if (!cpu_online(cpu))
 161                         return -ENODEV;
 162
 163                 reg = ENERGY_CORE_MSR;
 164         }
 165         amd_add_delta(data, channel, cpu, val, reg);
 166
 167         return 0;
 168 }
 169
 170 static umode_t amd_energy_is_visible(const void *_data,
 171                                      enum hwmon_sensor_types type,
 172                                      u32 attr, int channel)
 173 {
 174         return 0440;
 175 }
 176
 177 static int energy_accumulator(void *p)
 178 {
 179         struct amd_energy_data *data = (struct amd_energy_data *)p;
 180         unsigned int timeout = data->timeout_ms;
 181
 182         while (!kthread_should_stop()) {
 183                 /*
 184                  * Ignoring the conditions such as
 185                  * cpu being offline or rdmsr failure
 186                  */
 187                 read_accumulate(data);
 188
 189                 set_current_state(TASK_INTERRUPTIBLE);
 190                 if (kthread_should_stop())
 191                         break;
 192
 193                 schedule_timeout(msecs_to_jiffies(timeout));
 194         }
 195         return 0;
 196 }
 197
 198 static const struct hwmon_ops amd_energy_ops = {
 199         .is_visible = amd_energy_is_visible,
 200         .read = amd_energy_read,
 201         .read_string = amd_energy_read_labels,
 202 };
 203
 204 static int amd_create_sensor(struct device *dev,
 205                              struct amd_energy_data *data,
 206                              enum hwmon_sensor_types type, u32 config)
 207 {
 208         struct hwmon_channel_info *info = &data->energy_info;
 209         struct sensor_accumulator *accums;
 210         int i, num_siblings, cpus, sockets;
 211         u32 *s_config;
 212         char (*label_l)[10];
 213
 214         /* Identify the number of siblings per core */
 215         num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;
 216
 217         sockets = num_possible_nodes();
 218
 219         /*
 220          * Energy counter register is accessed at core level.
 221          * Hence, filterout the siblings.
 222          */
 223         cpus = num_present_cpus() / num_siblings;
 224
 225         s_config = devm_kcalloc(dev, cpus + sockets,
 226                                 sizeof(u32), GFP_KERNEL);
 227         if (!s_config)
 228                 return -ENOMEM;
 229
 230         accums = devm_kcalloc(dev, cpus + sockets,
 231                               sizeof(struct sensor_accumulator),
 232                               GFP_KERNEL);
 233         if (!accums)
 234                 return -ENOMEM;
 235
 236         label_l = devm_kcalloc(dev, cpus + sockets,
 237                                sizeof(*label_l), GFP_KERNEL);
 238         if (!label_l)
 239                 return -ENOMEM;
 240
 241         info->type = type;
 242         info->config = s_config;
 243
 244         data->nr_cpus = cpus;
 245         data->nr_socks = sockets;
 246         data->accums = accums;
 247         data->label = label_l;
 248
 249         for (i = 0; i < cpus + sockets; i++) {
 250                 s_config[i] = config;
 251                 if (i < cpus)
 252                         scnprintf(label_l[i], 10, "Ecore%03u", i);
 253                 else
 254                         scnprintf(label_l[i], 10, "Esocket%u", (i - cpus));
 255         }
 256
 257         return 0;
 258 }
 259
 260 static int amd_energy_probe(struct platform_device *pdev)
 261 {
 262         struct device *hwmon_dev;
 263         struct amd_energy_data *data;
 264         struct device *dev = &pdev->dev;
 265         int ret;
 266
 267         data = devm_kzalloc(dev,
 268                             sizeof(struct amd_energy_data), GFP_KERNEL);
 269         if (!data)
 270                 return -ENOMEM;
 271
 272         data->chip.ops = &amd_energy_ops;
 273         data->chip.info = data->info;
 274
 275         dev_set_drvdata(dev, data);
 276         /* Populate per-core energy reporting */
 277         data->info[0] = &data->energy_info;
 278         ret = amd_create_sensor(dev, data, hwmon_energy,
 279                                 HWMON_E_INPUT | HWMON_E_LABEL);
 280         if (ret)
 281                 return ret;
 282
 283         mutex_init(&data->lock);
 284         get_energy_units(data);
 285
 286         hwmon_dev = devm_hwmon_device_register_with_info(dev, DRVNAME,
 287                                                          data,
 288                                                          &data->chip,
 289                                                          NULL);
 290         if (IS_ERR(hwmon_dev))
 291                 return PTR_ERR(hwmon_dev);
 292
 293         /*
 294          * On a system with peak wattage of 250W
 295          * timeout = 2 ^ 32 / 2 ^ energy_units / 250 secs
 296          */
 297         data->timeout_ms = 1000 *
 298                            BIT(min(28, 31 - data->energy_units)) / 250;
 299
 300         data->wrap_accumulate = kthread_run(energy_accumulator, data,
 301                                             "%s", dev_name(hwmon_dev));
 302         return PTR_ERR_OR_ZERO(data->wrap_accumulate);
 303 }
 304
 305 static int amd_energy_remove(struct platform_device *pdev)
 306 {
 307         struct amd_energy_data *data = dev_get_drvdata(&pdev->dev);
 308
 309         if (data && data->wrap_accumulate)
 310                 kthread_stop(data->wrap_accumulate);
 311
 312         return 0;
 313 }
 314
 315 static const struct platform_device_id amd_energy_ids[] = {
 316         { .name = DRVNAME, },
 317         {}
 318 };
 319 MODULE_DEVICE_TABLE(platform, amd_energy_ids);
 320
 321 static struct platform_driver amd_energy_driver = {
 322         .probe = amd_energy_probe,
 323         .remove = amd_energy_remove,
 324         .id_table = amd_energy_ids,
 325         .driver = {
 326                 .name = DRVNAME,
 327         },
 328 };
 329
 330 static struct platform_device *amd_energy_platdev;
 331
 332 static const struct x86_cpu_id cpu_ids[] __initconst = {
 333         X86_MATCH_VENDOR_FAM_MODEL(AMD, 0x17, 0x31, NULL),
 334         X86_MATCH_VENDOR_FAM_MODEL(AMD, 0x19, 0x01, NULL),
 335         {}
 336 };
 337 MODULE_DEVICE_TABLE(x86cpu, cpu_ids);
 338
 339 static int __init amd_energy_init(void)
 340 {
 341         int ret;
 342
 343         if (!x86_match_cpu(cpu_ids))
 344                 return -ENODEV;
 345
 346         ret = platform_driver_register(&amd_energy_driver);
 347         if (ret)
 348                 return ret;
 349
 350         amd_energy_platdev = platform_device_alloc(DRVNAME, 0);
 351         if (!amd_energy_platdev) {
 352                 platform_driver_unregister(&amd_energy_driver);
 353                 return -ENOMEM;
 354         }
 355
 356         ret = platform_device_add(amd_energy_platdev);
 357         if (ret) {
 358                 platform_device_put(amd_energy_platdev);
 359                 platform_driver_unregister(&amd_energy_driver);
 360                 return ret;
 361         }
 362
 363         return ret;
 364 }
 365
 366 static void __exit amd_energy_exit(void)
 367 {
 368         platform_device_unregister(amd_energy_platdev);
 369         platform_driver_unregister(&amd_energy_driver);
 370 }
 371
 372 module_init(amd_energy_init);
 373 module_exit(amd_energy_exit);
 374
 375 MODULE_DESCRIPTION("Driver for AMD Energy reporting from RAPL MSR via HWMON interface");
 376 MODULE_AUTHOR("Naveen Krishna Chatradhi <nchatrad@amd.com>");
 377 MODULE_LICENSE("GPL");