drivers/powercap/intel_rapl.c

   1 /*
   2  * Intel Running Average Power Limit (RAPL) Driver
   3  * Copyright (c) 2013, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.
  16  *
  17  */
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/list.h>
  23 #include <linux/types.h>
  24 #include <linux/device.h>
  25 #include <linux/slab.h>
  26 #include <linux/log2.h>
  27 #include <linux/bitmap.h>
  28 #include <linux/delay.h>
  29 #include <linux/sysfs.h>
  30 #include <linux/cpu.h>
  31 #include <linux/powercap.h>
  32
  33 #include <asm/processor.h>
  34 #include <asm/cpu_device_id.h>
  35
  36 /* bitmasks for RAPL MSRs, used by primitive access functions */
  37 #define ENERGY_STATUS_MASK      0xffffffff
  38
  39 #define POWER_LIMIT1_MASK       0x7FFF
  40 #define POWER_LIMIT1_ENABLE     BIT(15)
  41 #define POWER_LIMIT1_CLAMP      BIT(16)
  42
  43 #define POWER_LIMIT2_MASK       (0x7FFFULL<<32)
  44 #define POWER_LIMIT2_ENABLE     BIT_ULL(47)
  45 #define POWER_LIMIT2_CLAMP      BIT_ULL(48)
  46 #define POWER_PACKAGE_LOCK      BIT_ULL(63)
  47 #define POWER_PP_LOCK           BIT(31)
  48
  49 #define TIME_WINDOW1_MASK       (0x7FULL<<17)
  50 #define TIME_WINDOW2_MASK       (0x7FULL<<49)
  51
  52 #define POWER_UNIT_OFFSET       0
  53 #define POWER_UNIT_MASK         0x0F
  54
  55 #define ENERGY_UNIT_OFFSET      0x08
  56 #define ENERGY_UNIT_MASK        0x1F00
  57
  58 #define TIME_UNIT_OFFSET        0x10
  59 #define TIME_UNIT_MASK          0xF0000
  60
  61 #define POWER_INFO_MAX_MASK     (0x7fffULL<<32)
  62 #define POWER_INFO_MIN_MASK     (0x7fffULL<<16)
  63 #define POWER_INFO_MAX_TIME_WIN_MASK     (0x3fULL<<48)
  64 #define POWER_INFO_THERMAL_SPEC_MASK     0x7fff
  65
  66 #define PERF_STATUS_THROTTLE_TIME_MASK 0xffffffff
  67 #define PP_POLICY_MASK         0x1F
  68
  69 /* Non HW constants */
  70 #define RAPL_PRIMITIVE_DERIVED       BIT(1) /* not from raw data */
  71 #define RAPL_PRIMITIVE_DUMMY         BIT(2)
  72
  73 /* scale RAPL units to avoid floating point math inside kernel */
  74 #define POWER_UNIT_SCALE     (1000000)
  75 #define ENERGY_UNIT_SCALE    (1000000)
  76 #define TIME_UNIT_SCALE      (1000000)
  77
  78 #define TIME_WINDOW_MAX_MSEC 40000
  79 #define TIME_WINDOW_MIN_MSEC 250
  80
  81 enum unit_type {
  82         ARBITRARY_UNIT, /* no translation */
  83         POWER_UNIT,
  84         ENERGY_UNIT,
  85         TIME_UNIT,
  86 };
  87
  88 enum rapl_domain_type {
  89         RAPL_DOMAIN_PACKAGE, /* entire package/socket */
  90         RAPL_DOMAIN_PP0, /* core power plane */
  91         RAPL_DOMAIN_PP1, /* graphics uncore */
  92         RAPL_DOMAIN_DRAM,/* DRAM control_type */
  93         RAPL_DOMAIN_MAX,
  94 };
  95
  96 enum rapl_domain_msr_id {
  97         RAPL_DOMAIN_MSR_LIMIT,
  98         RAPL_DOMAIN_MSR_STATUS,
  99         RAPL_DOMAIN_MSR_PERF,
 100         RAPL_DOMAIN_MSR_POLICY,
 101         RAPL_DOMAIN_MSR_INFO,
 102         RAPL_DOMAIN_MSR_MAX,
 103 };
 104
 105 /* per domain data, some are optional */
 106 enum rapl_primitives {
 107         ENERGY_COUNTER,
 108         POWER_LIMIT1,
 109         POWER_LIMIT2,
 110         FW_LOCK,
 111
 112         PL1_ENABLE,  /* power limit 1, aka long term */
 113         PL1_CLAMP,   /* allow frequency to go below OS request */
 114         PL2_ENABLE,  /* power limit 2, aka short term, instantaneous */
 115         PL2_CLAMP,
 116
 117         TIME_WINDOW1, /* long term */
 118         TIME_WINDOW2, /* short term */
 119         THERMAL_SPEC_POWER,
 120         MAX_POWER,
 121
 122         MIN_POWER,
 123         MAX_TIME_WINDOW,
 124         THROTTLED_TIME,
 125         PRIORITY_LEVEL,
 126
 127         /* below are not raw primitive data */
 128         AVERAGE_POWER,
 129         NR_RAPL_PRIMITIVES,
 130 };
 131
 132 #define NR_RAW_PRIMITIVES (NR_RAPL_PRIMITIVES - 2)
 133
 134 /* Can be expanded to include events, etc.*/
 135 struct rapl_domain_data {
 136         u64 primitives[NR_RAPL_PRIMITIVES];
 137         unsigned long timestamp;
 138 };
 139
 140
 141 #define DOMAIN_STATE_INACTIVE           BIT(0)
 142 #define DOMAIN_STATE_POWER_LIMIT_SET    BIT(1)
 143 #define DOMAIN_STATE_BIOS_LOCKED        BIT(2)
 144
 145 #define NR_POWER_LIMITS (2)
 146 struct rapl_power_limit {
 147         struct powercap_zone_constraint *constraint;
 148         int prim_id; /* primitive ID used to enable */
 149         struct rapl_domain *domain;
 150         const char *name;
 151 };
 152
 153 static const char pl1_name[] = "long_term";
 154 static const char pl2_name[] = "short_term";
 155
 156 struct rapl_domain {
 157         const char *name;
 158         enum rapl_domain_type id;
 159         int msrs[RAPL_DOMAIN_MSR_MAX];
 160         struct powercap_zone power_zone;
 161         struct rapl_domain_data rdd;
 162         struct rapl_power_limit rpl[NR_POWER_LIMITS];
 163         u64 attr_map; /* track capabilities */
 164         unsigned int state;
 165         int package_id;
 166 };
 167 #define power_zone_to_rapl_domain(_zone) \
 168         container_of(_zone, struct rapl_domain, power_zone)
 169
 170
 171 /* Each physical package contains multiple domains, these are the common
 172  * data across RAPL domains within a package.
 173  */
 174 struct rapl_package {
 175         unsigned int id; /* physical package/socket id */
 176         unsigned int nr_domains;
 177         unsigned long domain_map; /* bit map of active domains */
 178         unsigned int power_unit_divisor;
 179         unsigned int energy_unit_divisor;
 180         unsigned int time_unit_divisor;
 181         struct rapl_domain *domains; /* array of domains, sized at runtime */
 182         struct powercap_zone *power_zone; /* keep track of parent zone */
 183         int nr_cpus; /* active cpus on the package, topology info is lost during
 184                       * cpu hotplug. so we have to track ourselves.
 185                       */
 186         unsigned long power_limit_irq; /* keep track of package power limit
 187                                         * notify interrupt enable status.
 188                                         */
 189         struct list_head plist;
 190 };
 191 #define PACKAGE_PLN_INT_SAVED   BIT(0)
 192 #define MAX_PRIM_NAME (32)
 193
 194 /* per domain data. used to describe individual knobs such that access function
 195  * can be consolidated into one instead of many inline functions.
 196  */
 197 struct rapl_primitive_info {
 198         const char *name;
 199         u64 mask;
 200         int shift;
 201         enum rapl_domain_msr_id id;
 202         enum unit_type unit;
 203         u32 flag;
 204 };
 205
 206 #define PRIMITIVE_INFO_INIT(p, m, s, i, u, f) { \
 207                 .name = #p,                     \
 208                 .mask = m,                      \
 209                 .shift = s,                     \
 210                 .id = i,                        \
 211                 .unit = u,                      \
 212                 .flag = f                       \
 213         }
 214
 215 static void rapl_init_domains(struct rapl_package *rp);
 216 static int rapl_read_data_raw(struct rapl_domain *rd,
 217                         enum rapl_primitives prim,
 218                         bool xlate, u64 *data);
 219 static int rapl_write_data_raw(struct rapl_domain *rd,
 220                         enum rapl_primitives prim,
 221                         unsigned long long value);
 222 static u64 rapl_unit_xlate(int package, enum unit_type type, u64 value,
 223                         int to_raw);
 224 static void package_power_limit_irq_save(int package_id);
 225
 226 static LIST_HEAD(rapl_packages); /* guarded by CPU hotplug lock */
 227
 228 static const char * const rapl_domain_names[] = {
 229         "package",
 230         "core",
 231         "uncore",
 232         "dram",
 233 };
 234
 235 static struct powercap_control_type *control_type; /* PowerCap Controller */
 236
 237 /* caller to ensure CPU hotplug lock is held */
 238 static struct rapl_package *find_package_by_id(int id)
 239 {
 240         struct rapl_package *rp;
 241
 242         list_for_each_entry(rp, &rapl_packages, plist) {
 243                 if (rp->id == id)
 244                         return rp;
 245         }
 246
 247         return NULL;
 248 }
 249
 250 /* caller to ensure CPU hotplug lock is held */
 251 static int find_active_cpu_on_package(int package_id)
 252 {
 253         int i;
 254
 255         for_each_online_cpu(i) {
 256                 if (topology_physical_package_id(i) == package_id)
 257                         return i;
 258         }
 259         /* all CPUs on this package are offline */
 260
 261         return -ENODEV;
 262 }
 263
 264 /* caller must hold cpu hotplug lock */
 265 static void rapl_cleanup_data(void)
 266 {
 267         struct rapl_package *p, *tmp;
 268
 269         list_for_each_entry_safe(p, tmp, &rapl_packages, plist) {
 270                 kfree(p->domains);
 271                 list_del(&p->plist);
 272                 kfree(p);
 273         }
 274 }
 275
 276 static int get_energy_counter(struct powercap_zone *power_zone, u64 *energy_raw)
 277 {
 278         struct rapl_domain *rd;
 279         u64 energy_now;
 280
 281         /* prevent CPU hotplug, make sure the RAPL domain does not go
 282          * away while reading the counter.
 283          */
 284         get_online_cpus();
 285         rd = power_zone_to_rapl_domain(power_zone);
 286
 287         if (!rapl_read_data_raw(rd, ENERGY_COUNTER, true, &energy_now)) {
 288                 *energy_raw = energy_now;
 289                 put_online_cpus();
 290
 291                 return 0;
 292         }
 293         put_online_cpus();
 294
 295         return -EIO;
 296 }
 297
 298 static int get_max_energy_counter(struct powercap_zone *pcd_dev, u64 *energy)
 299 {
 300         *energy = rapl_unit_xlate(0, ENERGY_UNIT, ENERGY_STATUS_MASK, 0);
 301         return 0;
 302 }
 303
 304 static int release_zone(struct powercap_zone *power_zone)
 305 {
 306         struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
 307         struct rapl_package *rp;
 308
 309         /* package zone is the last zone of a package, we can free
 310          * memory here since all children has been unregistered.
 311          */
 312         if (rd->id == RAPL_DOMAIN_PACKAGE) {
 313                 rp = find_package_by_id(rd->package_id);
 314                 if (!rp) {
 315                         dev_warn(&power_zone->dev, "no package id %s\n",
 316                                 rd->name);
 317                         return -ENODEV;
 318                 }
 319                 kfree(rd);
 320                 rp->domains = NULL;
 321         }
 322
 323         return 0;
 324
 325 }
 326
 327 static int find_nr_power_limit(struct rapl_domain *rd)
 328 {
 329         int i;
 330
 331         for (i = 0; i < NR_POWER_LIMITS; i++) {
 332                 if (rd->rpl[i].name == NULL)
 333                         break;
 334         }
 335
 336         return i;
 337 }
 338
 339 static int set_domain_enable(struct powercap_zone *power_zone, bool mode)
 340 {
 341         struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
 342         int nr_powerlimit;
 343
 344         if (rd->state & DOMAIN_STATE_BIOS_LOCKED)
 345                 return -EACCES;
 346         get_online_cpus();
 347         nr_powerlimit = find_nr_power_limit(rd);
 348         /* here we activate/deactivate the hardware for power limiting */
 349         rapl_write_data_raw(rd, PL1_ENABLE, mode);
 350         /* always enable clamp such that p-state can go below OS requested
 351          * range. power capping priority over guranteed frequency.
 352          */
 353         rapl_write_data_raw(rd, PL1_CLAMP, mode);
 354         /* some domains have pl2 */
 355         if (nr_powerlimit > 1) {
 356                 rapl_write_data_raw(rd, PL2_ENABLE, mode);
 357                 rapl_write_data_raw(rd, PL2_CLAMP, mode);
 358         }
 359         put_online_cpus();
 360
 361         return 0;
 362 }
 363
 364 static int get_domain_enable(struct powercap_zone *power_zone, bool *mode)
 365 {
 366         struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
 367         u64 val;
 368
 369         if (rd->state & DOMAIN_STATE_BIOS_LOCKED) {
 370                 *mode = false;
 371                 return 0;
 372         }
 373         get_online_cpus();
 374         if (rapl_read_data_raw(rd, PL1_ENABLE, true, &val)) {
 375                 put_online_cpus();
 376                 return -EIO;
 377         }
 378         *mode = val;
 379         put_online_cpus();
 380
 381         return 0;
 382 }
 383
 384 /* per RAPL domain ops, in the order of rapl_domain_type */
 385 static struct powercap_zone_ops zone_ops[] = {
 386         /* RAPL_DOMAIN_PACKAGE */
 387         {
 388                 .get_energy_uj = get_energy_counter,
 389                 .get_max_energy_range_uj = get_max_energy_counter,
 390                 .release = release_zone,
 391                 .set_enable = set_domain_enable,
 392                 .get_enable = get_domain_enable,
 393         },
 394         /* RAPL_DOMAIN_PP0 */
 395         {
 396                 .get_energy_uj = get_energy_counter,
 397                 .get_max_energy_range_uj = get_max_energy_counter,
 398                 .release = release_zone,
 399                 .set_enable = set_domain_enable,
 400                 .get_enable = get_domain_enable,
 401         },
 402         /* RAPL_DOMAIN_PP1 */
 403         {
 404                 .get_energy_uj = get_energy_counter,
 405                 .get_max_energy_range_uj = get_max_energy_counter,
 406                 .release = release_zone,
 407                 .set_enable = set_domain_enable,
 408                 .get_enable = get_domain_enable,
 409         },
 410         /* RAPL_DOMAIN_DRAM */
 411         {
 412                 .get_energy_uj = get_energy_counter,
 413                 .get_max_energy_range_uj = get_max_energy_counter,
 414                 .release = release_zone,
 415                 .set_enable = set_domain_enable,
 416                 .get_enable = get_domain_enable,
 417         },
 418 };
 419
 420 static int set_power_limit(struct powercap_zone *power_zone, int id,
 421                         u64 power_limit)
 422 {
 423         struct rapl_domain *rd;
 424         struct rapl_package *rp;
 425         int ret = 0;
 426
 427         get_online_cpus();
 428         rd = power_zone_to_rapl_domain(power_zone);
 429         rp = find_package_by_id(rd->package_id);
 430         if (!rp) {
 431                 ret = -ENODEV;
 432                 goto set_exit;
 433         }
 434
 435         if (rd->state & DOMAIN_STATE_BIOS_LOCKED) {
 436                 dev_warn(&power_zone->dev, "%s locked by BIOS, monitoring only\n",
 437                         rd->name);
 438                 ret = -EACCES;
 439                 goto set_exit;
 440         }
 441
 442         switch (rd->rpl[id].prim_id) {
 443         case PL1_ENABLE:
 444                 rapl_write_data_raw(rd, POWER_LIMIT1, power_limit);
 445                 break;
 446         case PL2_ENABLE:
 447                 rapl_write_data_raw(rd, POWER_LIMIT2, power_limit);
 448                 break;
 449         default:
 450                 ret = -EINVAL;
 451         }
 452         if (!ret)
 453                 package_power_limit_irq_save(rd->package_id);
 454 set_exit:
 455         put_online_cpus();
 456         return ret;
 457 }
 458
 459 static int get_current_power_limit(struct powercap_zone *power_zone, int id,
 460                                         u64 *data)
 461 {
 462         struct rapl_domain *rd;
 463         u64 val;
 464         int prim;
 465         int ret = 0;
 466
 467         get_online_cpus();
 468         rd = power_zone_to_rapl_domain(power_zone);
 469         switch (rd->rpl[id].prim_id) {
 470         case PL1_ENABLE:
 471                 prim = POWER_LIMIT1;
 472                 break;
 473         case PL2_ENABLE:
 474                 prim = POWER_LIMIT2;
 475                 break;
 476         default:
 477                 put_online_cpus();
 478                 return -EINVAL;
 479         }
 480         if (rapl_read_data_raw(rd, prim, true, &val))
 481                 ret = -EIO;
 482         else
 483                 *data = val;
 484
 485         put_online_cpus();
 486
 487         return ret;
 488 }
 489
 490 static int set_time_window(struct powercap_zone *power_zone, int id,
 491                                                                 u64 window)
 492 {
 493         struct rapl_domain *rd;
 494         int ret = 0;
 495
 496         get_online_cpus();
 497         rd = power_zone_to_rapl_domain(power_zone);
 498         switch (rd->rpl[id].prim_id) {
 499         case PL1_ENABLE:
 500                 rapl_write_data_raw(rd, TIME_WINDOW1, window);
 501                 break;
 502         case PL2_ENABLE:
 503                 rapl_write_data_raw(rd, TIME_WINDOW2, window);
 504                 break;
 505         default:
 506                 ret = -EINVAL;
 507         }
 508         put_online_cpus();
 509         return ret;
 510 }
 511
 512 static int get_time_window(struct powercap_zone *power_zone, int id, u64 *data)
 513 {
 514         struct rapl_domain *rd;
 515         u64 val;
 516         int ret = 0;
 517
 518         get_online_cpus();
 519         rd = power_zone_to_rapl_domain(power_zone);
 520         switch (rd->rpl[id].prim_id) {
 521         case PL1_ENABLE:
 522                 ret = rapl_read_data_raw(rd, TIME_WINDOW1, true, &val);
 523                 break;
 524         case PL2_ENABLE:
 525                 ret = rapl_read_data_raw(rd, TIME_WINDOW2, true, &val);
 526                 break;
 527         default:
 528                 put_online_cpus();
 529                 return -EINVAL;
 530         }
 531         if (!ret)
 532                 *data = val;
 533         put_online_cpus();
 534
 535         return ret;
 536 }
 537
 538 static const char *get_constraint_name(struct powercap_zone *power_zone, int id)
 539 {
 540         struct rapl_power_limit *rpl;
 541         struct rapl_domain *rd;
 542
 543         rd = power_zone_to_rapl_domain(power_zone);
 544         rpl = (struct rapl_power_limit *) &rd->rpl[id];
 545
 546         return rpl->name;
 547 }
 548
 549
 550 static int get_max_power(struct powercap_zone *power_zone, int id,
 551                                         u64 *data)
 552 {
 553         struct rapl_domain *rd;
 554         u64 val;
 555         int prim;
 556         int ret = 0;
 557
 558         get_online_cpus();
 559         rd = power_zone_to_rapl_domain(power_zone);
 560         switch (rd->rpl[id].prim_id) {
 561         case PL1_ENABLE:
 562                 prim = THERMAL_SPEC_POWER;
 563                 break;
 564         case PL2_ENABLE:
 565                 prim = MAX_POWER;
 566                 break;
 567         default:
 568                 put_online_cpus();
 569                 return -EINVAL;
 570         }
 571         if (rapl_read_data_raw(rd, prim, true, &val))
 572                 ret = -EIO;
 573         else
 574                 *data = val;
 575
 576         put_online_cpus();
 577
 578         return ret;
 579 }
 580
 581 static struct powercap_zone_constraint_ops constraint_ops = {
 582         .set_power_limit_uw = set_power_limit,
 583         .get_power_limit_uw = get_current_power_limit,
 584         .set_time_window_us = set_time_window,
 585         .get_time_window_us = get_time_window,
 586         .get_max_power_uw = get_max_power,
 587         .get_name = get_constraint_name,
 588 };
 589
 590 /* called after domain detection and package level data are set */
 591 static void rapl_init_domains(struct rapl_package *rp)
 592 {
 593         int i;
 594         struct rapl_domain *rd = rp->domains;
 595
 596         for (i = 0; i < RAPL_DOMAIN_MAX; i++) {
 597                 unsigned int mask = rp->domain_map & (1 << i);
 598                 switch (mask) {
 599                 case BIT(RAPL_DOMAIN_PACKAGE):
 600                         rd->name = rapl_domain_names[RAPL_DOMAIN_PACKAGE];
 601                         rd->id = RAPL_DOMAIN_PACKAGE;
 602                         rd->msrs[0] = MSR_PKG_POWER_LIMIT;
 603                         rd->msrs[1] = MSR_PKG_ENERGY_STATUS;
 604                         rd->msrs[2] = MSR_PKG_PERF_STATUS;
 605                         rd->msrs[3] = 0;
 606                         rd->msrs[4] = MSR_PKG_POWER_INFO;
 607                         rd->rpl[0].prim_id = PL1_ENABLE;
 608                         rd->rpl[0].name = pl1_name;
 609                         rd->rpl[1].prim_id = PL2_ENABLE;
 610                         rd->rpl[1].name = pl2_name;
 611                         break;
 612                 case BIT(RAPL_DOMAIN_PP0):
 613                         rd->name = rapl_domain_names[RAPL_DOMAIN_PP0];
 614                         rd->id = RAPL_DOMAIN_PP0;
 615                         rd->msrs[0] = MSR_PP0_POWER_LIMIT;
 616                         rd->msrs[1] = MSR_PP0_ENERGY_STATUS;
 617                         rd->msrs[2] = 0;
 618                         rd->msrs[3] = MSR_PP0_POLICY;
 619                         rd->msrs[4] = 0;
 620                         rd->rpl[0].prim_id = PL1_ENABLE;
 621                         rd->rpl[0].name = pl1_name;
 622                         break;
 623                 case BIT(RAPL_DOMAIN_PP1):
 624                         rd->name = rapl_domain_names[RAPL_DOMAIN_PP1];
 625                         rd->id = RAPL_DOMAIN_PP1;
 626                         rd->msrs[0] = MSR_PP1_POWER_LIMIT;
 627                         rd->msrs[1] = MSR_PP1_ENERGY_STATUS;
 628                         rd->msrs[2] = 0;
 629                         rd->msrs[3] = MSR_PP1_POLICY;
 630                         rd->msrs[4] = 0;
 631                         rd->rpl[0].prim_id = PL1_ENABLE;
 632                         rd->rpl[0].name = pl1_name;
 633                         break;
 634                 case BIT(RAPL_DOMAIN_DRAM):
 635                         rd->name = rapl_domain_names[RAPL_DOMAIN_DRAM];
 636                         rd->id = RAPL_DOMAIN_DRAM;
 637                         rd->msrs[0] = MSR_DRAM_POWER_LIMIT;
 638                         rd->msrs[1] = MSR_DRAM_ENERGY_STATUS;
 639                         rd->msrs[2] = MSR_DRAM_PERF_STATUS;
 640                         rd->msrs[3] = 0;
 641                         rd->msrs[4] = MSR_DRAM_POWER_INFO;
 642                         rd->rpl[0].prim_id = PL1_ENABLE;
 643                         rd->rpl[0].name = pl1_name;
 644                         break;
 645                 }
 646                 if (mask) {
 647                         rd->package_id = rp->id;
 648                         rd++;
 649                 }
 650         }
 651 }
 652
 653 static u64 rapl_unit_xlate(int package, enum unit_type type, u64 value,
 654                         int to_raw)
 655 {
 656         u64 divisor = 1;
 657         int scale = 1; /* scale to user friendly data without floating point */
 658         u64 f, y; /* fraction and exp. used for time unit */
 659         struct rapl_package *rp;
 660
 661         rp = find_package_by_id(package);
 662         if (!rp)
 663                 return value;
 664
 665         switch (type) {
 666         case POWER_UNIT:
 667                 divisor = rp->power_unit_divisor;
 668                 scale = POWER_UNIT_SCALE;
 669                 break;
 670         case ENERGY_UNIT:
 671                 scale = ENERGY_UNIT_SCALE;
 672                 divisor = rp->energy_unit_divisor;
 673                 break;
 674         case TIME_UNIT:
 675                 divisor = rp->time_unit_divisor;
 676                 scale = TIME_UNIT_SCALE;
 677                 /* special processing based on 2^Y*(1+F)/4 = val/divisor, refer
 678                  * to Intel Software Developer's manual Vol. 3a, CH 14.7.4.
 679                  */
 680                 if (!to_raw) {
 681                         f = (value & 0x60) >> 5;
 682                         y = value & 0x1f;
 683                         value = (1 << y) * (4 + f) * scale / 4;
 684                         return div64_u64(value, divisor);
 685                 } else {
 686                         do_div(value, scale);
 687                         value *= divisor;
 688                         y = ilog2(value);
 689                         f = div64_u64(4 * (value - (1 << y)), 1 << y);
 690                         value = (y & 0x1f) | ((f & 0x3) << 5);
 691                         return value;
 692                 }
 693                 break;
 694         case ARBITRARY_UNIT:
 695         default:
 696                 return value;
 697         };
 698
 699         if (to_raw)
 700                 return div64_u64(value * divisor, scale);
 701         else
 702                 return div64_u64(value * scale, divisor);
 703 }
 704
 705 /* in the order of enum rapl_primitives */
 706 static struct rapl_primitive_info rpi[] = {
 707         /* name, mask, shift, msr index, unit divisor */
 708         PRIMITIVE_INFO_INIT(ENERGY_COUNTER, ENERGY_STATUS_MASK, 0,
 709                                 RAPL_DOMAIN_MSR_STATUS, ENERGY_UNIT, 0),
 710         PRIMITIVE_INFO_INIT(POWER_LIMIT1, POWER_LIMIT1_MASK, 0,
 711                                 RAPL_DOMAIN_MSR_LIMIT, POWER_UNIT, 0),
 712         PRIMITIVE_INFO_INIT(POWER_LIMIT2, POWER_LIMIT2_MASK, 32,
 713                                 RAPL_DOMAIN_MSR_LIMIT, POWER_UNIT, 0),
 714         PRIMITIVE_INFO_INIT(FW_LOCK, POWER_PP_LOCK, 31,
 715                                 RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
 716         PRIMITIVE_INFO_INIT(PL1_ENABLE, POWER_LIMIT1_ENABLE, 15,
 717                                 RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
 718         PRIMITIVE_INFO_INIT(PL1_CLAMP, POWER_LIMIT1_CLAMP, 16,
 719                                 RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
 720         PRIMITIVE_INFO_INIT(PL2_ENABLE, POWER_LIMIT2_ENABLE, 47,
 721                                 RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
 722         PRIMITIVE_INFO_INIT(PL2_CLAMP, POWER_LIMIT2_CLAMP, 48,
 723                                 RAPL_DOMAIN_MSR_LIMIT, ARBITRARY_UNIT, 0),
 724         PRIMITIVE_INFO_INIT(TIME_WINDOW1, TIME_WINDOW1_MASK, 17,
 725                                 RAPL_DOMAIN_MSR_LIMIT, TIME_UNIT, 0),
 726         PRIMITIVE_INFO_INIT(TIME_WINDOW2, TIME_WINDOW2_MASK, 49,
 727                                 RAPL_DOMAIN_MSR_LIMIT, TIME_UNIT, 0),
 728         PRIMITIVE_INFO_INIT(THERMAL_SPEC_POWER, POWER_INFO_THERMAL_SPEC_MASK,
 729                                 0, RAPL_DOMAIN_MSR_INFO, POWER_UNIT, 0),
 730         PRIMITIVE_INFO_INIT(MAX_POWER, POWER_INFO_MAX_MASK, 32,
 731                                 RAPL_DOMAIN_MSR_INFO, POWER_UNIT, 0),
 732         PRIMITIVE_INFO_INIT(MIN_POWER, POWER_INFO_MIN_MASK, 16,
 733                                 RAPL_DOMAIN_MSR_INFO, POWER_UNIT, 0),
 734         PRIMITIVE_INFO_INIT(MAX_TIME_WINDOW, POWER_INFO_MAX_TIME_WIN_MASK, 48,
 735                                 RAPL_DOMAIN_MSR_INFO, TIME_UNIT, 0),
 736         PRIMITIVE_INFO_INIT(THROTTLED_TIME, PERF_STATUS_THROTTLE_TIME_MASK, 0,
 737                                 RAPL_DOMAIN_MSR_PERF, TIME_UNIT, 0),
 738         PRIMITIVE_INFO_INIT(PRIORITY_LEVEL, PP_POLICY_MASK, 0,
 739                                 RAPL_DOMAIN_MSR_POLICY, ARBITRARY_UNIT, 0),
 740         /* non-hardware */
 741         PRIMITIVE_INFO_INIT(AVERAGE_POWER, 0, 0, 0, POWER_UNIT,
 742                                 RAPL_PRIMITIVE_DERIVED),
 743         {NULL, 0, 0, 0},
 744 };
 745
 746 /* Read primitive data based on its related struct rapl_primitive_info.
 747  * if xlate flag is set, return translated data based on data units, i.e.
 748  * time, energy, and power.
 749  * RAPL MSRs are non-architectual and are laid out not consistently across
 750  * domains. Here we use primitive info to allow writing consolidated access
 751  * functions.
 752  * For a given primitive, it is processed by MSR mask and shift. Unit conversion
 753  * is pre-assigned based on RAPL unit MSRs read at init time.
 754  * 63-------------------------- 31--------------------------- 0
 755  * |                           xxxxx (mask)                   |
 756  * |                                |<- shift ----------------|
 757  * 63-------------------------- 31--------------------------- 0
 758  */
 759 static int rapl_read_data_raw(struct rapl_domain *rd,
 760                         enum rapl_primitives prim,
 761                         bool xlate, u64 *data)
 762 {
 763         u64 value, final;
 764         u32 msr;
 765         struct rapl_primitive_info *rp = &rpi[prim];
 766         int cpu;
 767
 768         if (!rp->name || rp->flag & RAPL_PRIMITIVE_DUMMY)
 769                 return -EINVAL;
 770
 771         msr = rd->msrs[rp->id];
 772         if (!msr)
 773                 return -EINVAL;
 774         /* use physical package id to look up active cpus */
 775         cpu = find_active_cpu_on_package(rd->package_id);
 776         if (cpu < 0)
 777                 return cpu;
 778
 779         /* special-case package domain, which uses a different bit*/
 780         if (prim == FW_LOCK && rd->id == RAPL_DOMAIN_PACKAGE) {
 781                 rp->mask = POWER_PACKAGE_LOCK;
 782                 rp->shift = 63;
 783         }
 784         /* non-hardware data are collected by the polling thread */
 785         if (rp->flag & RAPL_PRIMITIVE_DERIVED) {
 786                 *data = rd->rdd.primitives[prim];
 787                 return 0;
 788         }
 789
 790         if (rdmsrl_safe_on_cpu(cpu, msr, &value)) {
 791                 pr_debug("failed to read msr 0x%x on cpu %d\n", msr, cpu);
 792                 return -EIO;
 793         }
 794
 795         final = value & rp->mask;
 796         final = final >> rp->shift;
 797         if (xlate)
 798                 *data = rapl_unit_xlate(rd->package_id, rp->unit, final, 0);
 799         else
 800                 *data = final;
 801
 802         return 0;
 803 }
 804
 805 /* Similar use of primitive info in the read counterpart */
 806 static int rapl_write_data_raw(struct rapl_domain *rd,
 807                         enum rapl_primitives prim,
 808                         unsigned long long value)
 809 {
 810         u64 msr_val;
 811         u32 msr;
 812         struct rapl_primitive_info *rp = &rpi[prim];
 813         int cpu;
 814
 815         cpu = find_active_cpu_on_package(rd->package_id);
 816         if (cpu < 0)
 817                 return cpu;
 818         msr = rd->msrs[rp->id];
 819         if (rdmsrl_safe_on_cpu(cpu, msr, &msr_val)) {
 820                 dev_dbg(&rd->power_zone.dev,
 821                         "failed to read msr 0x%x on cpu %d\n", msr, cpu);
 822                 return -EIO;
 823         }
 824         value = rapl_unit_xlate(rd->package_id, rp->unit, value, 1);
 825         msr_val &= ~rp->mask;
 826         msr_val |= value << rp->shift;
 827         if (wrmsrl_safe_on_cpu(cpu, msr, msr_val)) {
 828                 dev_dbg(&rd->power_zone.dev,
 829                         "failed to write msr 0x%x on cpu %d\n", msr, cpu);
 830                 return -EIO;
 831         }
 832
 833         return 0;
 834 }
 835
 836 static int rapl_check_unit(struct rapl_package *rp, int cpu)
 837 {
 838         u64 msr_val;
 839         u32 value;
 840
 841         if (rdmsrl_safe_on_cpu(cpu, MSR_RAPL_POWER_UNIT, &msr_val)) {
 842                 pr_err("Failed to read power unit MSR 0x%x on CPU %d, exit.\n",
 843                         MSR_RAPL_POWER_UNIT, cpu);
 844                 return -ENODEV;
 845         }
 846
 847         /* Raw RAPL data stored in MSRs are in certain scales. We need to
 848          * convert them into standard units based on the divisors reported in
 849          * the RAPL unit MSRs.
 850          * i.e.
 851          * energy unit: 1/enery_unit_divisor Joules
 852          * power unit: 1/power_unit_divisor Watts
 853          * time unit: 1/time_unit_divisor Seconds
 854          */
 855         value = (msr_val & ENERGY_UNIT_MASK) >> ENERGY_UNIT_OFFSET;
 856         rp->energy_unit_divisor = 1 << value;
 857
 858
 859         value = (msr_val & POWER_UNIT_MASK) >> POWER_UNIT_OFFSET;
 860         rp->power_unit_divisor = 1 << value;
 861
 862         value = (msr_val & TIME_UNIT_MASK) >> TIME_UNIT_OFFSET;
 863         rp->time_unit_divisor = 1 << value;
 864
 865         pr_debug("Physical package %d units: energy=%d, time=%d, power=%d\n",
 866                 rp->id,
 867                 rp->energy_unit_divisor,
 868                 rp->time_unit_divisor,
 869                 rp->power_unit_divisor);
 870
 871         return 0;
 872 }
 873
 874 /* REVISIT:
 875  * When package power limit is set artificially low by RAPL, LVT
 876  * thermal interrupt for package power limit should be ignored
 877  * since we are not really exceeding the real limit. The intention
 878  * is to avoid excessive interrupts while we are trying to save power.
 879  * A useful feature might be routing the package_power_limit interrupt
 880  * to userspace via eventfd. once we have a usecase, this is simple
 881  * to do by adding an atomic notifier.
 882  */
 883
 884 static void package_power_limit_irq_save(int package_id)
 885 {
 886         u32 l, h = 0;
 887         int cpu;
 888         struct rapl_package *rp;
 889
 890         rp = find_package_by_id(package_id);
 891         if (!rp)
 892                 return;
 893
 894         if (!boot_cpu_has(X86_FEATURE_PTS) || !boot_cpu_has(X86_FEATURE_PLN))
 895                 return;
 896
 897         cpu = find_active_cpu_on_package(package_id);
 898         if (cpu < 0)
 899                 return;
 900         /* save the state of PLN irq mask bit before disabling it */
 901         rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
 902         if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED)) {
 903                 rp->power_limit_irq = l & PACKAGE_THERM_INT_PLN_ENABLE;
 904                 rp->power_limit_irq |= PACKAGE_PLN_INT_SAVED;
 905         }
 906         l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
 907         wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 908 }
 909
 910 /* restore per package power limit interrupt enable state */
 911 static void package_power_limit_irq_restore(int package_id)
 912 {
 913         u32 l, h;
 914         int cpu;
 915         struct rapl_package *rp;
 916
 917         rp = find_package_by_id(package_id);
 918         if (!rp)
 919                 return;
 920
 921         if (!boot_cpu_has(X86_FEATURE_PTS) || !boot_cpu_has(X86_FEATURE_PLN))
 922                 return;
 923
 924         cpu = find_active_cpu_on_package(package_id);
 925         if (cpu < 0)
 926                 return;
 927
 928         /* irq enable state not saved, nothing to restore */
 929         if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED))
 930                 return;
 931         rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
 932
 933         if (rp->power_limit_irq & PACKAGE_THERM_INT_PLN_ENABLE)
 934                 l |= PACKAGE_THERM_INT_PLN_ENABLE;
 935         else
 936                 l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
 937
 938         wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 939 }
 940
 941 static const struct x86_cpu_id rapl_ids[] = {
 942         { X86_VENDOR_INTEL, 6, 0x2a},/* SNB */
 943         { X86_VENDOR_INTEL, 6, 0x2d},/* SNB EP */
 944         { X86_VENDOR_INTEL, 6, 0x3a},/* IVB */
 945         { X86_VENDOR_INTEL, 6, 0x45},/* HSW */
 946         /* TODO: Add more CPU IDs after testing */
 947         {}
 948 };
 949 MODULE_DEVICE_TABLE(x86cpu, rapl_ids);
 950
 951 /* read once for all raw primitive data for all packages, domains */
 952 static void rapl_update_domain_data(void)
 953 {
 954         int dmn, prim;
 955         u64 val;
 956         struct rapl_package *rp;
 957
 958         list_for_each_entry(rp, &rapl_packages, plist) {
 959                 for (dmn = 0; dmn < rp->nr_domains; dmn++) {
 960                         pr_debug("update package %d domain %s data\n", rp->id,
 961                                 rp->domains[dmn].name);
 962                         /* exclude non-raw primitives */
 963                         for (prim = 0; prim < NR_RAW_PRIMITIVES; prim++)
 964                                 if (!rapl_read_data_raw(&rp->domains[dmn], prim,
 965                                                                 rpi[prim].unit,
 966                                                                 &val))
 967                                         rp->domains[dmn].rdd.primitives[prim] =
 968                                                                         val;
 969                 }
 970         }
 971
 972 }
 973
 974 static int rapl_unregister_powercap(void)
 975 {
 976         struct rapl_package *rp;
 977         struct rapl_domain *rd, *rd_package = NULL;
 978
 979         /* unregister all active rapl packages from the powercap layer,
 980          * hotplug lock held
 981          */
 982         list_for_each_entry(rp, &rapl_packages, plist) {
 983                 package_power_limit_irq_restore(rp->id);
 984
 985                 for (rd = rp->domains; rd < rp->domains + rp->nr_domains;
 986                      rd++) {
 987                         pr_debug("remove package, undo power limit on %d: %s\n",
 988                                 rp->id, rd->name);
 989                         rapl_write_data_raw(rd, PL1_ENABLE, 0);
 990                         rapl_write_data_raw(rd, PL2_ENABLE, 0);
 991                         rapl_write_data_raw(rd, PL1_CLAMP, 0);
 992                         rapl_write_data_raw(rd, PL2_CLAMP, 0);
 993                         if (rd->id == RAPL_DOMAIN_PACKAGE) {
 994                                 rd_package = rd;
 995                                 continue;
 996                         }
 997                         powercap_unregister_zone(control_type, &rd->power_zone);
 998                 }
 999                 /* do the package zone last */
1000                 if (rd_package)
1001                         powercap_unregister_zone(control_type,
1002                                                 &rd_package->power_zone);
1003         }
1004         powercap_unregister_control_type(control_type);
1005
1006         return 0;
1007 }
1008
1009 static int rapl_package_register_powercap(struct rapl_package *rp)
1010 {
1011         struct rapl_domain *rd;
1012         int ret = 0;
1013         char dev_name[17]; /* max domain name = 7 + 1 + 8 for int + 1 for null*/
1014         struct powercap_zone *power_zone = NULL;
1015         int nr_pl;
1016
1017         /* first we register package domain as the parent zone*/
1018         for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
1019                 if (rd->id == RAPL_DOMAIN_PACKAGE) {
1020                         nr_pl = find_nr_power_limit(rd);
1021                         pr_debug("register socket %d package domain %s\n",
1022                                 rp->id, rd->name);
1023                         memset(dev_name, 0, sizeof(dev_name));
1024                         snprintf(dev_name, sizeof(dev_name), "%s-%d",
1025                                 rd->name, rp->id);
1026                         power_zone = powercap_register_zone(&rd->power_zone,
1027                                                         control_type,
1028                                                         dev_name, NULL,
1029                                                         &zone_ops[rd->id],
1030                                                         nr_pl,
1031                                                         &constraint_ops);
1032                         if (IS_ERR(power_zone)) {
1033                                 pr_debug("failed to register package, %d\n",
1034                                         rp->id);
1035                                 ret = PTR_ERR(power_zone);
1036                                 goto exit_package;
1037                         }
1038                         /* track parent zone in per package/socket data */
1039                         rp->power_zone = power_zone;
1040                         /* done, only one package domain per socket */
1041                         break;
1042                 }
1043         }
1044         if (!power_zone) {
1045                 pr_err("no package domain found, unknown topology!\n");
1046                 ret = -ENODEV;
1047                 goto exit_package;
1048         }
1049         /* now register domains as children of the socket/package*/
1050         for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
1051                 if (rd->id == RAPL_DOMAIN_PACKAGE)
1052                         continue;
1053                 /* number of power limits per domain varies */
1054                 nr_pl = find_nr_power_limit(rd);
1055                 power_zone = powercap_register_zone(&rd->power_zone,
1056                                                 control_type, rd->name,
1057                                                 rp->power_zone,
1058                                                 &zone_ops[rd->id], nr_pl,
1059                                                 &constraint_ops);
1060
1061                 if (IS_ERR(power_zone)) {
1062                         pr_debug("failed to register power_zone, %d:%s:%s\n",
1063                                 rp->id, rd->name, dev_name);
1064                         ret = PTR_ERR(power_zone);
1065                         goto err_cleanup;
1066                 }
1067         }
1068
1069 exit_package:
1070         return ret;
1071 err_cleanup:
1072         /* clean up previously initialized domains within the package if we
1073          * failed after the first domain setup.
1074          */
1075         while (--rd >= rp->domains) {
1076                 pr_debug("unregister package %d domain %s\n", rp->id, rd->name);
1077                 powercap_unregister_zone(control_type, &rd->power_zone);
1078         }
1079
1080         return ret;
1081 }
1082
1083 static int rapl_register_powercap(void)
1084 {
1085         struct rapl_domain *rd;
1086         struct rapl_package *rp;
1087         int ret = 0;
1088
1089         control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
1090         if (IS_ERR(control_type)) {
1091                 pr_debug("failed to register powercap control_type.\n");
1092                 return PTR_ERR(control_type);
1093         }
1094         /* read the initial data */
1095         rapl_update_domain_data();
1096         list_for_each_entry(rp, &rapl_packages, plist)
1097                 if (rapl_package_register_powercap(rp))
1098                         goto err_cleanup_package;
1099         return ret;
1100
1101 err_cleanup_package:
1102         /* clean up previously initialized packages */
1103         list_for_each_entry_continue_reverse(rp, &rapl_packages, plist) {
1104                 for (rd = rp->domains; rd < rp->domains + rp->nr_domains;
1105                      rd++) {
1106                         pr_debug("unregister zone/package %d, %s domain\n",
1107                                 rp->id, rd->name);
1108                         powercap_unregister_zone(control_type, &rd->power_zone);
1109                 }
1110         }
1111
1112         return ret;
1113 }
1114
1115 static int rapl_check_domain(int cpu, int domain)
1116 {
1117         unsigned msr;
1118         u64 val1, val2 = 0;
1119         int retry = 0;
1120
1121         switch (domain) {
1122         case RAPL_DOMAIN_PACKAGE:
1123                 msr = MSR_PKG_ENERGY_STATUS;
1124                 break;
1125         case RAPL_DOMAIN_PP0:
1126                 msr = MSR_PP0_ENERGY_STATUS;
1127                 break;
1128         case RAPL_DOMAIN_PP1:
1129                 msr = MSR_PP1_ENERGY_STATUS;
1130                 break;
1131         case RAPL_DOMAIN_DRAM:
1132                 msr = MSR_DRAM_ENERGY_STATUS;
1133                 break;
1134         default:
1135                 pr_err("invalid domain id %d\n", domain);
1136                 return -EINVAL;
1137         }
1138         if (rdmsrl_safe_on_cpu(cpu, msr, &val1))
1139                 return -ENODEV;
1140
1141         /* energy counters roll slowly on some domains */
1142         while (++retry < 10) {
1143                 usleep_range(10000, 15000);
1144                 rdmsrl_safe_on_cpu(cpu, msr, &val2);
1145                 if ((val1 & ENERGY_STATUS_MASK) != (val2 & ENERGY_STATUS_MASK))
1146                         return 0;
1147         }
1148         /* if energy counter does not change, report as bad domain */
1149         pr_info("domain %s energy ctr %llu:%llu not working, skip\n",
1150                 rapl_domain_names[domain], val1, val2);
1151
1152         return -ENODEV;
1153 }
1154
1155 /* Detect active and valid domains for the given CPU, caller must
1156  * ensure the CPU belongs to the targeted package and CPU hotlug is disabled.
1157  */
1158 static int rapl_detect_domains(struct rapl_package *rp, int cpu)
1159 {
1160         int i;
1161         int ret = 0;
1162         struct rapl_domain *rd;
1163         u64 locked;
1164
1165         for (i = 0; i < RAPL_DOMAIN_MAX; i++) {
1166                 /* use physical package id to read counters */
1167                 if (!rapl_check_domain(cpu, i))
1168                         rp->domain_map |= 1 << i;
1169         }
1170         rp->nr_domains = bitmap_weight(&rp->domain_map, RAPL_DOMAIN_MAX);
1171         if (!rp->nr_domains) {
1172                 pr_err("no valid rapl domains found in package %d\n", rp->id);
1173                 ret = -ENODEV;
1174                 goto done;
1175         }
1176         pr_debug("found %d domains on package %d\n", rp->nr_domains, rp->id);
1177
1178         rp->domains = kcalloc(rp->nr_domains + 1, sizeof(struct rapl_domain),
1179                         GFP_KERNEL);
1180         if (!rp->domains) {
1181                 ret = -ENOMEM;
1182                 goto done;
1183         }
1184         rapl_init_domains(rp);
1185
1186         for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
1187                 /* check if the domain is locked by BIOS */
1188                 if (rapl_read_data_raw(rd, FW_LOCK, false, &locked)) {
1189                         pr_info("RAPL package %d domain %s locked by BIOS\n",
1190                                 rp->id, rd->name);
1191                                 rd->state |= DOMAIN_STATE_BIOS_LOCKED;
1192                 }
1193         }
1194
1195
1196 done:
1197         return ret;
1198 }
1199
1200 static bool is_package_new(int package)
1201 {
1202         struct rapl_package *rp;
1203
1204         /* caller prevents cpu hotplug, there will be no new packages added
1205          * or deleted while traversing the package list, no need for locking.
1206          */
1207         list_for_each_entry(rp, &rapl_packages, plist)
1208                 if (package == rp->id)
1209                         return false;
1210
1211         return true;
1212 }
1213
1214 /* RAPL interface can be made of a two-level hierarchy: package level and domain
1215  * level. We first detect the number of packages then domains of each package.
1216  * We have to consider the possiblity of CPU online/offline due to hotplug and
1217  * other scenarios.
1218  */
1219 static int rapl_detect_topology(void)
1220 {
1221         int i;
1222         int phy_package_id;
1223         struct rapl_package *new_package, *rp;
1224
1225         for_each_online_cpu(i) {
1226                 phy_package_id = topology_physical_package_id(i);
1227                 if (is_package_new(phy_package_id)) {
1228                         new_package = kzalloc(sizeof(*rp), GFP_KERNEL);
1229                         if (!new_package) {
1230                                 rapl_cleanup_data();
1231                                 return -ENOMEM;
1232                         }
1233                         /* add the new package to the list */
1234                         new_package->id = phy_package_id;
1235                         new_package->nr_cpus = 1;
1236
1237                         /* check if the package contains valid domains */
1238                         if (rapl_detect_domains(new_package, i) ||
1239                                 rapl_check_unit(new_package, i)) {
1240                                 kfree(new_package->domains);
1241                                 kfree(new_package);
1242                                 /* free up the packages already initialized */
1243                                 rapl_cleanup_data();
1244                                 return -ENODEV;
1245                         }
1246                         INIT_LIST_HEAD(&new_package->plist);
1247                         list_add(&new_package->plist, &rapl_packages);
1248                 } else {
1249                         rp = find_package_by_id(phy_package_id);
1250                         if (rp)
1251                                 ++rp->nr_cpus;
1252                 }
1253         }
1254
1255         return 0;
1256 }
1257
1258 /* called from CPU hotplug notifier, hotplug lock held */
1259 static void rapl_remove_package(struct rapl_package *rp)
1260 {
1261         struct rapl_domain *rd, *rd_package = NULL;
1262
1263         for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
1264                 if (rd->id == RAPL_DOMAIN_PACKAGE) {
1265                         rd_package = rd;
1266                         continue;
1267                 }
1268                 pr_debug("remove package %d, %s domain\n", rp->id, rd->name);
1269                 powercap_unregister_zone(control_type, &rd->power_zone);
1270         }
1271         /* do parent zone last */
1272         powercap_unregister_zone(control_type, &rd_package->power_zone);
1273         list_del(&rp->plist);
1274         kfree(rp);
1275 }
1276
1277 /* called from CPU hotplug notifier, hotplug lock held */
1278 static int rapl_add_package(int cpu)
1279 {
1280         int ret = 0;
1281         int phy_package_id;
1282         struct rapl_package *rp;
1283
1284         phy_package_id = topology_physical_package_id(cpu);
1285         rp = kzalloc(sizeof(struct rapl_package), GFP_KERNEL);
1286         if (!rp)
1287                 return -ENOMEM;
1288
1289         /* add the new package to the list */
1290         rp->id = phy_package_id;
1291         rp->nr_cpus = 1;
1292         /* check if the package contains valid domains */
1293         if (rapl_detect_domains(rp, cpu) ||
1294                 rapl_check_unit(rp, cpu)) {
1295                 ret = -ENODEV;
1296                 goto err_free_package;
1297         }
1298         if (!rapl_package_register_powercap(rp)) {
1299                 INIT_LIST_HEAD(&rp->plist);
1300                 list_add(&rp->plist, &rapl_packages);
1301                 return ret;
1302         }
1303
1304 err_free_package:
1305         kfree(rp->domains);
1306         kfree(rp);
1307
1308         return ret;
1309 }
1310
1311 /* Handles CPU hotplug on multi-socket systems.
1312  * If a CPU goes online as the first CPU of the physical package
1313  * we add the RAPL package to the system. Similarly, when the last
1314  * CPU of the package is removed, we remove the RAPL package and its
1315  * associated domains. Cooling devices are handled accordingly at
1316  * per-domain level.
1317  */
1318 static int rapl_cpu_callback(struct notifier_block *nfb,
1319                                 unsigned long action, void *hcpu)
1320 {
1321         unsigned long cpu = (unsigned long)hcpu;
1322         int phy_package_id;
1323         struct rapl_package *rp;
1324
1325         phy_package_id = topology_physical_package_id(cpu);
1326         switch (action) {
1327         case CPU_ONLINE:
1328         case CPU_ONLINE_FROZEN:
1329         case CPU_DOWN_FAILED:
1330         case CPU_DOWN_FAILED_FROZEN:
1331                 rp = find_package_by_id(phy_package_id);
1332                 if (rp)
1333                         ++rp->nr_cpus;
1334                 else
1335                         rapl_add_package(cpu);
1336                 break;
1337         case CPU_DOWN_PREPARE:
1338         case CPU_DOWN_PREPARE_FROZEN:
1339                 rp = find_package_by_id(phy_package_id);
1340                 if (!rp)
1341                         break;
1342                 if (--rp->nr_cpus == 0)
1343                         rapl_remove_package(rp);
1344         }
1345
1346         return NOTIFY_OK;
1347 }
1348
1349 static struct notifier_block rapl_cpu_notifier = {
1350         .notifier_call = rapl_cpu_callback,
1351 };
1352
1353 static int __init rapl_init(void)
1354 {
1355         int ret = 0;
1356
1357         if (!x86_match_cpu(rapl_ids)) {
1358                 pr_err("driver does not support CPU family %d model %d\n",
1359                         boot_cpu_data.x86, boot_cpu_data.x86_model);
1360
1361                 return -ENODEV;
1362         }
1363         /* prevent CPU hotplug during detection */
1364         get_online_cpus();
1365         ret = rapl_detect_topology();
1366         if (ret)
1367                 goto done;
1368
1369         if (rapl_register_powercap()) {
1370                 rapl_cleanup_data();
1371                 ret = -ENODEV;
1372                 goto done;
1373         }
1374         register_hotcpu_notifier(&rapl_cpu_notifier);
1375 done:
1376         put_online_cpus();
1377
1378         return ret;
1379 }
1380
1381 static void __exit rapl_exit(void)
1382 {
1383         get_online_cpus();
1384         unregister_hotcpu_notifier(&rapl_cpu_notifier);
1385         rapl_unregister_powercap();
1386         rapl_cleanup_data();
1387         put_online_cpus();
1388 }
1389
1390 module_init(rapl_init);
1391 module_exit(rapl_exit);
1392
1393 MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit)");
1394 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>");
1395 MODULE_LICENSE("GPL v2");