linux/drivers/idle/intel_idle.c
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   1/*
   2 * intel_idle.c - native hardware idle loop for modern Intel processors
   3 *
   4 * Copyright (c) 2013, Intel Corporation.
   5 * Len Brown <len.brown@intel.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify it
   8 * under the terms and conditions of the GNU General Public License,
   9 * version 2, as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope it will be useful, but WITHOUT
  12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14 * more details.
  15 *
  16 * You should have received a copy of the GNU General Public License along with
  17 * this program; if not, write to the Free Software Foundation, Inc.,
  18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21/*
  22 * intel_idle is a cpuidle driver that loads on specific Intel processors
  23 * in lieu of the legacy ACPI processor_idle driver.  The intent is to
  24 * make Linux more efficient on these processors, as intel_idle knows
  25 * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
  26 */
  27
  28/*
  29 * Design Assumptions
  30 *
  31 * All CPUs have same idle states as boot CPU
  32 *
  33 * Chipset BM_STS (bus master status) bit is a NOP
  34 *      for preventing entry into deep C-stats
  35 */
  36
  37/*
  38 * Known limitations
  39 *
  40 * The driver currently initializes for_each_online_cpu() upon modprobe.
  41 * It it unaware of subsequent processors hot-added to the system.
  42 * This means that if you boot with maxcpus=n and later online
  43 * processors above n, those processors will use C1 only.
  44 *
  45 * ACPI has a .suspend hack to turn off deep c-statees during suspend
  46 * to avoid complications with the lapic timer workaround.
  47 * Have not seen issues with suspend, but may need same workaround here.
  48 *
  49 * There is currently no kernel-based automatic probing/loading mechanism
  50 * if the driver is built as a module.
  51 */
  52
  53/* un-comment DEBUG to enable pr_debug() statements */
  54#define DEBUG
  55
  56#include <linux/kernel.h>
  57#include <linux/cpuidle.h>
  58#include <linux/tick.h>
  59#include <trace/events/power.h>
  60#include <linux/sched.h>
  61#include <linux/notifier.h>
  62#include <linux/cpu.h>
  63#include <linux/module.h>
  64#include <asm/cpu_device_id.h>
  65#include <asm/mwait.h>
  66#include <asm/msr.h>
  67
  68#define INTEL_IDLE_VERSION "0.4.1"
  69#define PREFIX "intel_idle: "
  70
  71static struct cpuidle_driver intel_idle_driver = {
  72        .name = "intel_idle",
  73        .owner = THIS_MODULE,
  74};
  75/* intel_idle.max_cstate=0 disables driver */
  76static int max_cstate = CPUIDLE_STATE_MAX - 1;
  77
  78static unsigned int mwait_substates;
  79
  80#define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
  81/* Reliable LAPIC Timer States, bit 1 for C1 etc.  */
  82static unsigned int lapic_timer_reliable_states = (1 << 1);      /* Default to only C1 */
  83
  84struct idle_cpu {
  85        struct cpuidle_state *state_table;
  86
  87        /*
  88         * Hardware C-state auto-demotion may not always be optimal.
  89         * Indicate which enable bits to clear here.
  90         */
  91        unsigned long auto_demotion_disable_flags;
  92        bool byt_auto_demotion_disable_flag;
  93        bool disable_promotion_to_c1e;
  94};
  95
  96static const struct idle_cpu *icpu;
  97static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
  98static int intel_idle(struct cpuidle_device *dev,
  99                        struct cpuidle_driver *drv, int index);
 100static void intel_idle_freeze(struct cpuidle_device *dev,
 101                              struct cpuidle_driver *drv, int index);
 102static int intel_idle_cpu_init(int cpu);
 103
 104static struct cpuidle_state *cpuidle_state_table;
 105
 106/*
 107 * Set this flag for states where the HW flushes the TLB for us
 108 * and so we don't need cross-calls to keep it consistent.
 109 * If this flag is set, SW flushes the TLB, so even if the
 110 * HW doesn't do the flushing, this flag is safe to use.
 111 */
 112#define CPUIDLE_FLAG_TLB_FLUSHED        0x10000
 113
 114/*
 115 * MWAIT takes an 8-bit "hint" in EAX "suggesting"
 116 * the C-state (top nibble) and sub-state (bottom nibble)
 117 * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
 118 *
 119 * We store the hint at the top of our "flags" for each state.
 120 */
 121#define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
 122#define MWAIT2flg(eax) ((eax & 0xFF) << 24)
 123
 124/*
 125 * States are indexed by the cstate number,
 126 * which is also the index into the MWAIT hint array.
 127 * Thus C0 is a dummy.
 128 */
 129static struct cpuidle_state nehalem_cstates[] = {
 130        {
 131                .name = "C1-NHM",
 132                .desc = "MWAIT 0x00",
 133                .flags = MWAIT2flg(0x00),
 134                .exit_latency = 3,
 135                .target_residency = 6,
 136                .enter = &intel_idle,
 137                .enter_freeze = intel_idle_freeze, },
 138        {
 139                .name = "C1E-NHM",
 140                .desc = "MWAIT 0x01",
 141                .flags = MWAIT2flg(0x01),
 142                .exit_latency = 10,
 143                .target_residency = 20,
 144                .enter = &intel_idle,
 145                .enter_freeze = intel_idle_freeze, },
 146        {
 147                .name = "C3-NHM",
 148                .desc = "MWAIT 0x10",
 149                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 150                .exit_latency = 20,
 151                .target_residency = 80,
 152                .enter = &intel_idle,
 153                .enter_freeze = intel_idle_freeze, },
 154        {
 155                .name = "C6-NHM",
 156                .desc = "MWAIT 0x20",
 157                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 158                .exit_latency = 200,
 159                .target_residency = 800,
 160                .enter = &intel_idle,
 161                .enter_freeze = intel_idle_freeze, },
 162        {
 163                .enter = NULL }
 164};
 165
 166static struct cpuidle_state snb_cstates[] = {
 167        {
 168                .name = "C1-SNB",
 169                .desc = "MWAIT 0x00",
 170                .flags = MWAIT2flg(0x00),
 171                .exit_latency = 2,
 172                .target_residency = 2,
 173                .enter = &intel_idle,
 174                .enter_freeze = intel_idle_freeze, },
 175        {
 176                .name = "C1E-SNB",
 177                .desc = "MWAIT 0x01",
 178                .flags = MWAIT2flg(0x01),
 179                .exit_latency = 10,
 180                .target_residency = 20,
 181                .enter = &intel_idle,
 182                .enter_freeze = intel_idle_freeze, },
 183        {
 184                .name = "C3-SNB",
 185                .desc = "MWAIT 0x10",
 186                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 187                .exit_latency = 80,
 188                .target_residency = 211,
 189                .enter = &intel_idle,
 190                .enter_freeze = intel_idle_freeze, },
 191        {
 192                .name = "C6-SNB",
 193                .desc = "MWAIT 0x20",
 194                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 195                .exit_latency = 104,
 196                .target_residency = 345,
 197                .enter = &intel_idle,
 198                .enter_freeze = intel_idle_freeze, },
 199        {
 200                .name = "C7-SNB",
 201                .desc = "MWAIT 0x30",
 202                .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
 203                .exit_latency = 109,
 204                .target_residency = 345,
 205                .enter = &intel_idle,
 206                .enter_freeze = intel_idle_freeze, },
 207        {
 208                .enter = NULL }
 209};
 210
 211static struct cpuidle_state byt_cstates[] = {
 212        {
 213                .name = "C1-BYT",
 214                .desc = "MWAIT 0x00",
 215                .flags = MWAIT2flg(0x00),
 216                .exit_latency = 1,
 217                .target_residency = 1,
 218                .enter = &intel_idle,
 219                .enter_freeze = intel_idle_freeze, },
 220        {
 221                .name = "C6N-BYT",
 222                .desc = "MWAIT 0x58",
 223                .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
 224                .exit_latency = 300,
 225                .target_residency = 275,
 226                .enter = &intel_idle,
 227                .enter_freeze = intel_idle_freeze, },
 228        {
 229                .name = "C6S-BYT",
 230                .desc = "MWAIT 0x52",
 231                .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
 232                .exit_latency = 500,
 233                .target_residency = 560,
 234                .enter = &intel_idle,
 235                .enter_freeze = intel_idle_freeze, },
 236        {
 237                .name = "C7-BYT",
 238                .desc = "MWAIT 0x60",
 239                .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
 240                .exit_latency = 1200,
 241                .target_residency = 4000,
 242                .enter = &intel_idle,
 243                .enter_freeze = intel_idle_freeze, },
 244        {
 245                .name = "C7S-BYT",
 246                .desc = "MWAIT 0x64",
 247                .flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
 248                .exit_latency = 10000,
 249                .target_residency = 20000,
 250                .enter = &intel_idle,
 251                .enter_freeze = intel_idle_freeze, },
 252        {
 253                .enter = NULL }
 254};
 255
 256static struct cpuidle_state cht_cstates[] = {
 257        {
 258                .name = "C1-CHT",
 259                .desc = "MWAIT 0x00",
 260                .flags = MWAIT2flg(0x00),
 261                .exit_latency = 1,
 262                .target_residency = 1,
 263                .enter = &intel_idle,
 264                .enter_freeze = intel_idle_freeze, },
 265        {
 266                .name = "C6N-CHT",
 267                .desc = "MWAIT 0x58",
 268                .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
 269                .exit_latency = 80,
 270                .target_residency = 275,
 271                .enter = &intel_idle,
 272                .enter_freeze = intel_idle_freeze, },
 273        {
 274                .name = "C6S-CHT",
 275                .desc = "MWAIT 0x52",
 276                .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
 277                .exit_latency = 200,
 278                .target_residency = 560,
 279                .enter = &intel_idle,
 280                .enter_freeze = intel_idle_freeze, },
 281        {
 282                .name = "C7-CHT",
 283                .desc = "MWAIT 0x60",
 284                .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
 285                .exit_latency = 1200,
 286                .target_residency = 4000,
 287                .enter = &intel_idle,
 288                .enter_freeze = intel_idle_freeze, },
 289        {
 290                .name = "C7S-CHT",
 291                .desc = "MWAIT 0x64",
 292                .flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
 293                .exit_latency = 10000,
 294                .target_residency = 20000,
 295                .enter = &intel_idle,
 296                .enter_freeze = intel_idle_freeze, },
 297        {
 298                .enter = NULL }
 299};
 300
 301static struct cpuidle_state ivb_cstates[] = {
 302        {
 303                .name = "C1-IVB",
 304                .desc = "MWAIT 0x00",
 305                .flags = MWAIT2flg(0x00),
 306                .exit_latency = 1,
 307                .target_residency = 1,
 308                .enter = &intel_idle,
 309                .enter_freeze = intel_idle_freeze, },
 310        {
 311                .name = "C1E-IVB",
 312                .desc = "MWAIT 0x01",
 313                .flags = MWAIT2flg(0x01),
 314                .exit_latency = 10,
 315                .target_residency = 20,
 316                .enter = &intel_idle,
 317                .enter_freeze = intel_idle_freeze, },
 318        {
 319                .name = "C3-IVB",
 320                .desc = "MWAIT 0x10",
 321                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 322                .exit_latency = 59,
 323                .target_residency = 156,
 324                .enter = &intel_idle,
 325                .enter_freeze = intel_idle_freeze, },
 326        {
 327                .name = "C6-IVB",
 328                .desc = "MWAIT 0x20",
 329                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 330                .exit_latency = 80,
 331                .target_residency = 300,
 332                .enter = &intel_idle,
 333                .enter_freeze = intel_idle_freeze, },
 334        {
 335                .name = "C7-IVB",
 336                .desc = "MWAIT 0x30",
 337                .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
 338                .exit_latency = 87,
 339                .target_residency = 300,
 340                .enter = &intel_idle,
 341                .enter_freeze = intel_idle_freeze, },
 342        {
 343                .enter = NULL }
 344};
 345
 346static struct cpuidle_state ivt_cstates[] = {
 347        {
 348                .name = "C1-IVT",
 349                .desc = "MWAIT 0x00",
 350                .flags = MWAIT2flg(0x00),
 351                .exit_latency = 1,
 352                .target_residency = 1,
 353                .enter = &intel_idle,
 354                .enter_freeze = intel_idle_freeze, },
 355        {
 356                .name = "C1E-IVT",
 357                .desc = "MWAIT 0x01",
 358                .flags = MWAIT2flg(0x01),
 359                .exit_latency = 10,
 360                .target_residency = 80,
 361                .enter = &intel_idle,
 362                .enter_freeze = intel_idle_freeze, },
 363        {
 364                .name = "C3-IVT",
 365                .desc = "MWAIT 0x10",
 366                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 367                .exit_latency = 59,
 368                .target_residency = 156,
 369                .enter = &intel_idle,
 370                .enter_freeze = intel_idle_freeze, },
 371        {
 372                .name = "C6-IVT",
 373                .desc = "MWAIT 0x20",
 374                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 375                .exit_latency = 82,
 376                .target_residency = 300,
 377                .enter = &intel_idle,
 378                .enter_freeze = intel_idle_freeze, },
 379        {
 380                .enter = NULL }
 381};
 382
 383static struct cpuidle_state ivt_cstates_4s[] = {
 384        {
 385                .name = "C1-IVT-4S",
 386                .desc = "MWAIT 0x00",
 387                .flags = MWAIT2flg(0x00),
 388                .exit_latency = 1,
 389                .target_residency = 1,
 390                .enter = &intel_idle,
 391                .enter_freeze = intel_idle_freeze, },
 392        {
 393                .name = "C1E-IVT-4S",
 394                .desc = "MWAIT 0x01",
 395                .flags = MWAIT2flg(0x01),
 396                .exit_latency = 10,
 397                .target_residency = 250,
 398                .enter = &intel_idle,
 399                .enter_freeze = intel_idle_freeze, },
 400        {
 401                .name = "C3-IVT-4S",
 402                .desc = "MWAIT 0x10",
 403                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 404                .exit_latency = 59,
 405                .target_residency = 300,
 406                .enter = &intel_idle,
 407                .enter_freeze = intel_idle_freeze, },
 408        {
 409                .name = "C6-IVT-4S",
 410                .desc = "MWAIT 0x20",
 411                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 412                .exit_latency = 84,
 413                .target_residency = 400,
 414                .enter = &intel_idle,
 415                .enter_freeze = intel_idle_freeze, },
 416        {
 417                .enter = NULL }
 418};
 419
 420static struct cpuidle_state ivt_cstates_8s[] = {
 421        {
 422                .name = "C1-IVT-8S",
 423                .desc = "MWAIT 0x00",
 424                .flags = MWAIT2flg(0x00),
 425                .exit_latency = 1,
 426                .target_residency = 1,
 427                .enter = &intel_idle,
 428                .enter_freeze = intel_idle_freeze, },
 429        {
 430                .name = "C1E-IVT-8S",
 431                .desc = "MWAIT 0x01",
 432                .flags = MWAIT2flg(0x01),
 433                .exit_latency = 10,
 434                .target_residency = 500,
 435                .enter = &intel_idle,
 436                .enter_freeze = intel_idle_freeze, },
 437        {
 438                .name = "C3-IVT-8S",
 439                .desc = "MWAIT 0x10",
 440                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 441                .exit_latency = 59,
 442                .target_residency = 600,
 443                .enter = &intel_idle,
 444                .enter_freeze = intel_idle_freeze, },
 445        {
 446                .name = "C6-IVT-8S",
 447                .desc = "MWAIT 0x20",
 448                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 449                .exit_latency = 88,
 450                .target_residency = 700,
 451                .enter = &intel_idle,
 452                .enter_freeze = intel_idle_freeze, },
 453        {
 454                .enter = NULL }
 455};
 456
 457static struct cpuidle_state hsw_cstates[] = {
 458        {
 459                .name = "C1-HSW",
 460                .desc = "MWAIT 0x00",
 461                .flags = MWAIT2flg(0x00),
 462                .exit_latency = 2,
 463                .target_residency = 2,
 464                .enter = &intel_idle,
 465                .enter_freeze = intel_idle_freeze, },
 466        {
 467                .name = "C1E-HSW",
 468                .desc = "MWAIT 0x01",
 469                .flags = MWAIT2flg(0x01),
 470                .exit_latency = 10,
 471                .target_residency = 20,
 472                .enter = &intel_idle,
 473                .enter_freeze = intel_idle_freeze, },
 474        {
 475                .name = "C3-HSW",
 476                .desc = "MWAIT 0x10",
 477                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 478                .exit_latency = 33,
 479                .target_residency = 100,
 480                .enter = &intel_idle,
 481                .enter_freeze = intel_idle_freeze, },
 482        {
 483                .name = "C6-HSW",
 484                .desc = "MWAIT 0x20",
 485                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 486                .exit_latency = 133,
 487                .target_residency = 400,
 488                .enter = &intel_idle,
 489                .enter_freeze = intel_idle_freeze, },
 490        {
 491                .name = "C7s-HSW",
 492                .desc = "MWAIT 0x32",
 493                .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
 494                .exit_latency = 166,
 495                .target_residency = 500,
 496                .enter = &intel_idle,
 497                .enter_freeze = intel_idle_freeze, },
 498        {
 499                .name = "C8-HSW",
 500                .desc = "MWAIT 0x40",
 501                .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
 502                .exit_latency = 300,
 503                .target_residency = 900,
 504                .enter = &intel_idle,
 505                .enter_freeze = intel_idle_freeze, },
 506        {
 507                .name = "C9-HSW",
 508                .desc = "MWAIT 0x50",
 509                .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
 510                .exit_latency = 600,
 511                .target_residency = 1800,
 512                .enter = &intel_idle,
 513                .enter_freeze = intel_idle_freeze, },
 514        {
 515                .name = "C10-HSW",
 516                .desc = "MWAIT 0x60",
 517                .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
 518                .exit_latency = 2600,
 519                .target_residency = 7700,
 520                .enter = &intel_idle,
 521                .enter_freeze = intel_idle_freeze, },
 522        {
 523                .enter = NULL }
 524};
 525static struct cpuidle_state bdw_cstates[] = {
 526        {
 527                .name = "C1-BDW",
 528                .desc = "MWAIT 0x00",
 529                .flags = MWAIT2flg(0x00),
 530                .exit_latency = 2,
 531                .target_residency = 2,
 532                .enter = &intel_idle,
 533                .enter_freeze = intel_idle_freeze, },
 534        {
 535                .name = "C1E-BDW",
 536                .desc = "MWAIT 0x01",
 537                .flags = MWAIT2flg(0x01),
 538                .exit_latency = 10,
 539                .target_residency = 20,
 540                .enter = &intel_idle,
 541                .enter_freeze = intel_idle_freeze, },
 542        {
 543                .name = "C3-BDW",
 544                .desc = "MWAIT 0x10",
 545                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 546                .exit_latency = 40,
 547                .target_residency = 100,
 548                .enter = &intel_idle,
 549                .enter_freeze = intel_idle_freeze, },
 550        {
 551                .name = "C6-BDW",
 552                .desc = "MWAIT 0x20",
 553                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 554                .exit_latency = 133,
 555                .target_residency = 400,
 556                .enter = &intel_idle,
 557                .enter_freeze = intel_idle_freeze, },
 558        {
 559                .name = "C7s-BDW",
 560                .desc = "MWAIT 0x32",
 561                .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
 562                .exit_latency = 166,
 563                .target_residency = 500,
 564                .enter = &intel_idle,
 565                .enter_freeze = intel_idle_freeze, },
 566        {
 567                .name = "C8-BDW",
 568                .desc = "MWAIT 0x40",
 569                .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
 570                .exit_latency = 300,
 571                .target_residency = 900,
 572                .enter = &intel_idle,
 573                .enter_freeze = intel_idle_freeze, },
 574        {
 575                .name = "C9-BDW",
 576                .desc = "MWAIT 0x50",
 577                .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
 578                .exit_latency = 600,
 579                .target_residency = 1800,
 580                .enter = &intel_idle,
 581                .enter_freeze = intel_idle_freeze, },
 582        {
 583                .name = "C10-BDW",
 584                .desc = "MWAIT 0x60",
 585                .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
 586                .exit_latency = 2600,
 587                .target_residency = 7700,
 588                .enter = &intel_idle,
 589                .enter_freeze = intel_idle_freeze, },
 590        {
 591                .enter = NULL }
 592};
 593
 594static struct cpuidle_state skl_cstates[] = {
 595        {
 596                .name = "C1-SKL",
 597                .desc = "MWAIT 0x00",
 598                .flags = MWAIT2flg(0x00),
 599                .exit_latency = 2,
 600                .target_residency = 2,
 601                .enter = &intel_idle,
 602                .enter_freeze = intel_idle_freeze, },
 603        {
 604                .name = "C1E-SKL",
 605                .desc = "MWAIT 0x01",
 606                .flags = MWAIT2flg(0x01),
 607                .exit_latency = 10,
 608                .target_residency = 20,
 609                .enter = &intel_idle,
 610                .enter_freeze = intel_idle_freeze, },
 611        {
 612                .name = "C3-SKL",
 613                .desc = "MWAIT 0x10",
 614                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 615                .exit_latency = 70,
 616                .target_residency = 100,
 617                .enter = &intel_idle,
 618                .enter_freeze = intel_idle_freeze, },
 619        {
 620                .name = "C6-SKL",
 621                .desc = "MWAIT 0x20",
 622                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 623                .exit_latency = 85,
 624                .target_residency = 200,
 625                .enter = &intel_idle,
 626                .enter_freeze = intel_idle_freeze, },
 627        {
 628                .name = "C7s-SKL",
 629                .desc = "MWAIT 0x33",
 630                .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
 631                .exit_latency = 124,
 632                .target_residency = 800,
 633                .enter = &intel_idle,
 634                .enter_freeze = intel_idle_freeze, },
 635        {
 636                .name = "C8-SKL",
 637                .desc = "MWAIT 0x40",
 638                .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
 639                .exit_latency = 200,
 640                .target_residency = 800,
 641                .enter = &intel_idle,
 642                .enter_freeze = intel_idle_freeze, },
 643        {
 644                .name = "C9-SKL",
 645                .desc = "MWAIT 0x50",
 646                .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
 647                .exit_latency = 480,
 648                .target_residency = 5000,
 649                .enter = &intel_idle,
 650                .enter_freeze = intel_idle_freeze, },
 651        {
 652                .name = "C10-SKL",
 653                .desc = "MWAIT 0x60",
 654                .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
 655                .exit_latency = 890,
 656                .target_residency = 5000,
 657                .enter = &intel_idle,
 658                .enter_freeze = intel_idle_freeze, },
 659        {
 660                .enter = NULL }
 661};
 662
 663static struct cpuidle_state skx_cstates[] = {
 664        {
 665                .name = "C1-SKX",
 666                .desc = "MWAIT 0x00",
 667                .flags = MWAIT2flg(0x00),
 668                .exit_latency = 2,
 669                .target_residency = 2,
 670                .enter = &intel_idle,
 671                .enter_freeze = intel_idle_freeze, },
 672        {
 673                .name = "C1E-SKX",
 674                .desc = "MWAIT 0x01",
 675                .flags = MWAIT2flg(0x01),
 676                .exit_latency = 10,
 677                .target_residency = 20,
 678                .enter = &intel_idle,
 679                .enter_freeze = intel_idle_freeze, },
 680        {
 681                .name = "C6-SKX",
 682                .desc = "MWAIT 0x20",
 683                .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
 684                .exit_latency = 133,
 685                .target_residency = 600,
 686                .enter = &intel_idle,
 687                .enter_freeze = intel_idle_freeze, },
 688        {
 689                .enter = NULL }
 690};
 691
 692static struct cpuidle_state atom_cstates[] = {
 693        {
 694                .name = "C1E-ATM",
 695                .desc = "MWAIT 0x00",
 696                .flags = MWAIT2flg(0x00),
 697                .exit_latency = 10,
 698                .target_residency = 20,
 699                .enter = &intel_idle,
 700                .enter_freeze = intel_idle_freeze, },
 701        {
 702                .name = "C2-ATM",
 703                .desc = "MWAIT 0x10",
 704                .flags = MWAIT2flg(0x10),
 705                .exit_latency = 20,
 706                .target_residency = 80,
 707                .enter = &intel_idle,
 708                .enter_freeze = intel_idle_freeze, },
 709        {
 710                .name = "C4-ATM",
 711                .desc = "MWAIT 0x30",
 712                .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
 713                .exit_latency = 100,
 714                .target_residency = 400,
 715                .enter = &intel_idle,
 716                .enter_freeze = intel_idle_freeze, },
 717        {
 718                .name = "C6-ATM",
 719                .desc = "MWAIT 0x52",
 720                .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
 721                .exit_latency = 140,
 722                .target_residency = 560,
 723                .enter = &intel_idle,
 724                .enter_freeze = intel_idle_freeze, },
 725        {
 726                .enter = NULL }
 727};
 728static struct cpuidle_state avn_cstates[] = {
 729        {
 730                .name = "C1-AVN",
 731                .desc = "MWAIT 0x00",
 732                .flags = MWAIT2flg(0x00),
 733                .exit_latency = 2,
 734                .target_residency = 2,
 735                .enter = &intel_idle,
 736                .enter_freeze = intel_idle_freeze, },
 737        {
 738                .name = "C6-AVN",
 739                .desc = "MWAIT 0x51",
 740                .flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
 741                .exit_latency = 15,
 742                .target_residency = 45,
 743                .enter = &intel_idle,
 744                .enter_freeze = intel_idle_freeze, },
 745        {
 746                .enter = NULL }
 747};
 748static struct cpuidle_state knl_cstates[] = {
 749        {
 750                .name = "C1-KNL",
 751                .desc = "MWAIT 0x00",
 752                .flags = MWAIT2flg(0x00),
 753                .exit_latency = 1,
 754                .target_residency = 2,
 755                .enter = &intel_idle,
 756                .enter_freeze = intel_idle_freeze },
 757        {
 758                .name = "C6-KNL",
 759                .desc = "MWAIT 0x10",
 760                .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
 761                .exit_latency = 120,
 762                .target_residency = 500,
 763                .enter = &intel_idle,
 764                .enter_freeze = intel_idle_freeze },
 765        {
 766                .enter = NULL }
 767};
 768
 769/**
 770 * intel_idle
 771 * @dev: cpuidle_device
 772 * @drv: cpuidle driver
 773 * @index: index of cpuidle state
 774 *
 775 * Must be called under local_irq_disable().
 776 */
 777static int intel_idle(struct cpuidle_device *dev,
 778                struct cpuidle_driver *drv, int index)
 779{
 780        unsigned long ecx = 1; /* break on interrupt flag */
 781        struct cpuidle_state *state = &drv->states[index];
 782        unsigned long eax = flg2MWAIT(state->flags);
 783        unsigned int cstate;
 784        int cpu = smp_processor_id();
 785
 786        cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
 787
 788        /*
 789         * leave_mm() to avoid costly and often unnecessary wakeups
 790         * for flushing the user TLB's associated with the active mm.
 791         */
 792        if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
 793                leave_mm(cpu);
 794
 795        if (!(lapic_timer_reliable_states & (1 << (cstate))))
 796                tick_broadcast_enter();
 797
 798        mwait_idle_with_hints(eax, ecx);
 799
 800        if (!(lapic_timer_reliable_states & (1 << (cstate))))
 801                tick_broadcast_exit();
 802
 803        return index;
 804}
 805
 806/**
 807 * intel_idle_freeze - simplified "enter" callback routine for suspend-to-idle
 808 * @dev: cpuidle_device
 809 * @drv: cpuidle driver
 810 * @index: state index
 811 */
 812static void intel_idle_freeze(struct cpuidle_device *dev,
 813                             struct cpuidle_driver *drv, int index)
 814{
 815        unsigned long ecx = 1; /* break on interrupt flag */
 816        unsigned long eax = flg2MWAIT(drv->states[index].flags);
 817
 818        mwait_idle_with_hints(eax, ecx);
 819}
 820
 821static void __setup_broadcast_timer(void *arg)
 822{
 823        unsigned long on = (unsigned long)arg;
 824
 825        if (on)
 826                tick_broadcast_enable();
 827        else
 828                tick_broadcast_disable();
 829}
 830
 831static int cpu_hotplug_notify(struct notifier_block *n,
 832                              unsigned long action, void *hcpu)
 833{
 834        int hotcpu = (unsigned long)hcpu;
 835        struct cpuidle_device *dev;
 836
 837        switch (action & ~CPU_TASKS_FROZEN) {
 838        case CPU_ONLINE:
 839
 840                if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
 841                        smp_call_function_single(hotcpu, __setup_broadcast_timer,
 842                                                 (void *)true, 1);
 843
 844                /*
 845                 * Some systems can hotplug a cpu at runtime after
 846                 * the kernel has booted, we have to initialize the
 847                 * driver in this case
 848                 */
 849                dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
 850                if (dev->registered)
 851                        break;
 852
 853                if (intel_idle_cpu_init(hotcpu))
 854                        return NOTIFY_BAD;
 855
 856                break;
 857        }
 858        return NOTIFY_OK;
 859}
 860
 861static struct notifier_block cpu_hotplug_notifier = {
 862        .notifier_call = cpu_hotplug_notify,
 863};
 864
 865static void auto_demotion_disable(void *dummy)
 866{
 867        unsigned long long msr_bits;
 868
 869        rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
 870        msr_bits &= ~(icpu->auto_demotion_disable_flags);
 871        wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
 872}
 873static void c1e_promotion_disable(void *dummy)
 874{
 875        unsigned long long msr_bits;
 876
 877        rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
 878        msr_bits &= ~0x2;
 879        wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
 880}
 881
 882static const struct idle_cpu idle_cpu_nehalem = {
 883        .state_table = nehalem_cstates,
 884        .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
 885        .disable_promotion_to_c1e = true,
 886};
 887
 888static const struct idle_cpu idle_cpu_atom = {
 889        .state_table = atom_cstates,
 890};
 891
 892static const struct idle_cpu idle_cpu_lincroft = {
 893        .state_table = atom_cstates,
 894        .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
 895};
 896
 897static const struct idle_cpu idle_cpu_snb = {
 898        .state_table = snb_cstates,
 899        .disable_promotion_to_c1e = true,
 900};
 901
 902static const struct idle_cpu idle_cpu_byt = {
 903        .state_table = byt_cstates,
 904        .disable_promotion_to_c1e = true,
 905        .byt_auto_demotion_disable_flag = true,
 906};
 907
 908static const struct idle_cpu idle_cpu_cht = {
 909        .state_table = cht_cstates,
 910        .disable_promotion_to_c1e = true,
 911        .byt_auto_demotion_disable_flag = true,
 912};
 913
 914static const struct idle_cpu idle_cpu_ivb = {
 915        .state_table = ivb_cstates,
 916        .disable_promotion_to_c1e = true,
 917};
 918
 919static const struct idle_cpu idle_cpu_ivt = {
 920        .state_table = ivt_cstates,
 921        .disable_promotion_to_c1e = true,
 922};
 923
 924static const struct idle_cpu idle_cpu_hsw = {
 925        .state_table = hsw_cstates,
 926        .disable_promotion_to_c1e = true,
 927};
 928
 929static const struct idle_cpu idle_cpu_bdw = {
 930        .state_table = bdw_cstates,
 931        .disable_promotion_to_c1e = true,
 932};
 933
 934static const struct idle_cpu idle_cpu_skl = {
 935        .state_table = skl_cstates,
 936        .disable_promotion_to_c1e = true,
 937};
 938
 939static const struct idle_cpu idle_cpu_skx = {
 940        .state_table = skx_cstates,
 941        .disable_promotion_to_c1e = true,
 942};
 943
 944static const struct idle_cpu idle_cpu_avn = {
 945        .state_table = avn_cstates,
 946        .disable_promotion_to_c1e = true,
 947};
 948
 949static const struct idle_cpu idle_cpu_knl = {
 950        .state_table = knl_cstates,
 951};
 952
 953#define ICPU(model, cpu) \
 954        { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
 955
 956static const struct x86_cpu_id intel_idle_ids[] __initconst = {
 957        ICPU(0x1a, idle_cpu_nehalem),
 958        ICPU(0x1e, idle_cpu_nehalem),
 959        ICPU(0x1f, idle_cpu_nehalem),
 960        ICPU(0x25, idle_cpu_nehalem),
 961        ICPU(0x2c, idle_cpu_nehalem),
 962        ICPU(0x2e, idle_cpu_nehalem),
 963        ICPU(0x1c, idle_cpu_atom),
 964        ICPU(0x26, idle_cpu_lincroft),
 965        ICPU(0x2f, idle_cpu_nehalem),
 966        ICPU(0x2a, idle_cpu_snb),
 967        ICPU(0x2d, idle_cpu_snb),
 968        ICPU(0x36, idle_cpu_atom),
 969        ICPU(0x37, idle_cpu_byt),
 970        ICPU(0x4c, idle_cpu_cht),
 971        ICPU(0x3a, idle_cpu_ivb),
 972        ICPU(0x3e, idle_cpu_ivt),
 973        ICPU(0x3c, idle_cpu_hsw),
 974        ICPU(0x3f, idle_cpu_hsw),
 975        ICPU(0x45, idle_cpu_hsw),
 976        ICPU(0x46, idle_cpu_hsw),
 977        ICPU(0x4d, idle_cpu_avn),
 978        ICPU(0x3d, idle_cpu_bdw),
 979        ICPU(0x47, idle_cpu_bdw),
 980        ICPU(0x4f, idle_cpu_bdw),
 981        ICPU(0x56, idle_cpu_bdw),
 982        ICPU(0x4e, idle_cpu_skl),
 983        ICPU(0x5e, idle_cpu_skl),
 984        ICPU(0x8e, idle_cpu_skl),
 985        ICPU(0x9e, idle_cpu_skl),
 986        ICPU(0x55, idle_cpu_skx),
 987        ICPU(0x57, idle_cpu_knl),
 988        {}
 989};
 990MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
 991
 992/*
 993 * intel_idle_probe()
 994 */
 995static int __init intel_idle_probe(void)
 996{
 997        unsigned int eax, ebx, ecx;
 998        const struct x86_cpu_id *id;
 999
1000        if (max_cstate == 0) {
1001                pr_debug(PREFIX "disabled\n");
1002                return -EPERM;
1003        }
1004
1005        id = x86_match_cpu(intel_idle_ids);
1006        if (!id) {
1007                if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
1008                    boot_cpu_data.x86 == 6)
1009                        pr_debug(PREFIX "does not run on family %d model %d\n",
1010                                boot_cpu_data.x86, boot_cpu_data.x86_model);
1011                return -ENODEV;
1012        }
1013
1014        if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1015                return -ENODEV;
1016
1017        cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1018
1019        if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1020            !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1021            !mwait_substates)
1022                        return -ENODEV;
1023
1024        pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
1025
1026        icpu = (const struct idle_cpu *)id->driver_data;
1027        cpuidle_state_table = icpu->state_table;
1028
1029        pr_debug(PREFIX "v" INTEL_IDLE_VERSION
1030                " model 0x%X\n", boot_cpu_data.x86_model);
1031
1032        return 0;
1033}
1034
1035/*
1036 * intel_idle_cpuidle_devices_uninit()
1037 * Unregisters the cpuidle devices.
1038 */
1039static void intel_idle_cpuidle_devices_uninit(void)
1040{
1041        int i;
1042        struct cpuidle_device *dev;
1043
1044        for_each_online_cpu(i) {
1045                dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1046                cpuidle_unregister_device(dev);
1047        }
1048}
1049
1050/*
1051 * ivt_idle_state_table_update(void)
1052 *
1053 * Tune IVT multi-socket targets
1054 * Assumption: num_sockets == (max_package_num + 1)
1055 */
1056static void ivt_idle_state_table_update(void)
1057{
1058        /* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1059        int cpu, package_num, num_sockets = 1;
1060
1061        for_each_online_cpu(cpu) {
1062                package_num = topology_physical_package_id(cpu);
1063                if (package_num + 1 > num_sockets) {
1064                        num_sockets = package_num + 1;
1065
1066                        if (num_sockets > 4) {
1067                                cpuidle_state_table = ivt_cstates_8s;
1068                                return;
1069                        }
1070                }
1071        }
1072
1073        if (num_sockets > 2)
1074                cpuidle_state_table = ivt_cstates_4s;
1075
1076        /* else, 1 and 2 socket systems use default ivt_cstates */
1077}
1078/*
1079 * sklh_idle_state_table_update(void)
1080 *
1081 * On SKL-H (model 0x5e) disable C8 and C9 if:
1082 * C10 is enabled and SGX disabled
1083 */
1084static void sklh_idle_state_table_update(void)
1085{
1086        unsigned long long msr;
1087        unsigned int eax, ebx, ecx, edx;
1088
1089
1090        /* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1091        if (max_cstate <= 7)
1092                return;
1093
1094        /* if PC10 not present in CPUID.MWAIT.EDX */
1095        if ((mwait_substates & (0xF << 28)) == 0)
1096                return;
1097
1098        rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr);
1099
1100        /* PC10 is not enabled in PKG C-state limit */
1101        if ((msr & 0xF) != 8)
1102                return;
1103
1104        ecx = 0;
1105        cpuid(7, &eax, &ebx, &ecx, &edx);
1106
1107        /* if SGX is present */
1108        if (ebx & (1 << 2)) {
1109
1110                rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
1111
1112                /* if SGX is enabled */
1113                if (msr & (1 << 18))
1114                        return;
1115        }
1116
1117        skl_cstates[5].disabled = 1;    /* C8-SKL */
1118        skl_cstates[6].disabled = 1;    /* C9-SKL */
1119}
1120/*
1121 * intel_idle_state_table_update()
1122 *
1123 * Update the default state_table for this CPU-id
1124 */
1125
1126static void intel_idle_state_table_update(void)
1127{
1128        switch (boot_cpu_data.x86_model) {
1129
1130        case 0x3e: /* IVT */
1131                ivt_idle_state_table_update();
1132                break;
1133        case 0x5e: /* SKL-H */
1134                sklh_idle_state_table_update();
1135                break;
1136        }
1137}
1138
1139/*
1140 * intel_idle_cpuidle_driver_init()
1141 * allocate, initialize cpuidle_states
1142 */
1143static void __init intel_idle_cpuidle_driver_init(void)
1144{
1145        int cstate;
1146        struct cpuidle_driver *drv = &intel_idle_driver;
1147
1148        intel_idle_state_table_update();
1149
1150        drv->state_count = 1;
1151
1152        for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1153                int num_substates, mwait_hint, mwait_cstate;
1154
1155                if ((cpuidle_state_table[cstate].enter == NULL) &&
1156                    (cpuidle_state_table[cstate].enter_freeze == NULL))
1157                        break;
1158
1159                if (cstate + 1 > max_cstate) {
1160                        printk(PREFIX "max_cstate %d reached\n",
1161                                max_cstate);
1162                        break;
1163                }
1164
1165                mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1166                mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
1167
1168                /* number of sub-states for this state in CPUID.MWAIT */
1169                num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
1170                                        & MWAIT_SUBSTATE_MASK;
1171
1172                /* if NO sub-states for this state in CPUID, skip it */
1173                if (num_substates == 0)
1174                        continue;
1175
1176                /* if state marked as disabled, skip it */
1177                if (cpuidle_state_table[cstate].disabled != 0) {
1178                        pr_debug(PREFIX "state %s is disabled",
1179                                cpuidle_state_table[cstate].name);
1180                        continue;
1181                }
1182
1183
1184                if (((mwait_cstate + 1) > 2) &&
1185                        !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1186                        mark_tsc_unstable("TSC halts in idle"
1187                                        " states deeper than C2");
1188
1189                drv->states[drv->state_count] = /* structure copy */
1190                        cpuidle_state_table[cstate];
1191
1192                drv->state_count += 1;
1193        }
1194
1195        if (icpu->byt_auto_demotion_disable_flag) {
1196                wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1197                wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1198        }
1199}
1200
1201
1202/*
1203 * intel_idle_cpu_init()
1204 * allocate, initialize, register cpuidle_devices
1205 * @cpu: cpu/core to initialize
1206 */
1207static int intel_idle_cpu_init(int cpu)
1208{
1209        struct cpuidle_device *dev;
1210
1211        dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1212
1213        dev->cpu = cpu;
1214
1215        if (cpuidle_register_device(dev)) {
1216                pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
1217                return -EIO;
1218        }
1219
1220        if (icpu->auto_demotion_disable_flags)
1221                smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
1222
1223        if (icpu->disable_promotion_to_c1e)
1224                smp_call_function_single(cpu, c1e_promotion_disable, NULL, 1);
1225
1226        return 0;
1227}
1228
1229static int __init intel_idle_init(void)
1230{
1231        int retval, i;
1232
1233        /* Do not load intel_idle at all for now if idle= is passed */
1234        if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1235                return -ENODEV;
1236
1237        retval = intel_idle_probe();
1238        if (retval)
1239                return retval;
1240
1241        intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1242        if (intel_idle_cpuidle_devices == NULL)
1243                return -ENOMEM;
1244
1245        intel_idle_cpuidle_driver_init();
1246        retval = cpuidle_register_driver(&intel_idle_driver);
1247        if (retval) {
1248                struct cpuidle_driver *drv = cpuidle_get_driver();
1249                printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
1250                        drv ? drv->name : "none");
1251                free_percpu(intel_idle_cpuidle_devices);
1252                return retval;
1253        }
1254
1255        cpu_notifier_register_begin();
1256
1257        for_each_online_cpu(i) {
1258                retval = intel_idle_cpu_init(i);
1259                if (retval) {
1260                        intel_idle_cpuidle_devices_uninit();
1261                        cpu_notifier_register_done();
1262                        cpuidle_unregister_driver(&intel_idle_driver);
1263                        free_percpu(intel_idle_cpuidle_devices);
1264                        return retval;
1265                }
1266        }
1267        __register_cpu_notifier(&cpu_hotplug_notifier);
1268
1269        if (boot_cpu_has(X86_FEATURE_ARAT))     /* Always Reliable APIC Timer */
1270                lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
1271        else
1272                on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
1273
1274        cpu_notifier_register_done();
1275
1276        pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
1277                lapic_timer_reliable_states);
1278
1279        return 0;
1280}
1281
1282static void __exit intel_idle_exit(void)
1283{
1284        struct cpuidle_device *dev;
1285        int i;
1286
1287        cpu_notifier_register_begin();
1288
1289        if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
1290                on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
1291        __unregister_cpu_notifier(&cpu_hotplug_notifier);
1292
1293        for_each_possible_cpu(i) {
1294                dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1295                cpuidle_unregister_device(dev);
1296        }
1297
1298        cpu_notifier_register_done();
1299
1300        cpuidle_unregister_driver(&intel_idle_driver);
1301        free_percpu(intel_idle_cpuidle_devices);
1302}
1303
1304module_init(intel_idle_init);
1305module_exit(intel_idle_exit);
1306
1307module_param(max_cstate, int, 0444);
1308
1309MODULE_AUTHOR("Len Brown <len.brown@intel.com>");
1310MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION);
1311MODULE_LICENSE("GPL");
1312