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" 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 atom_cstates[] = { 595 { 596 .name = "C1E-ATM", 597 .desc = "MWAIT 0x00", 598 .flags = MWAIT2flg(0x00), 599 .exit_latency = 10, 600 .target_residency = 20, 601 .enter = &intel_idle, 602 .enter_freeze = intel_idle_freeze, }, 603 { 604 .name = "C2-ATM", 605 .desc = "MWAIT 0x10", 606 .flags = MWAIT2flg(0x10), 607 .exit_latency = 20, 608 .target_residency = 80, 609 .enter = &intel_idle, 610 .enter_freeze = intel_idle_freeze, }, 611 { 612 .name = "C4-ATM", 613 .desc = "MWAIT 0x30", 614 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED, 615 .exit_latency = 100, 616 .target_residency = 400, 617 .enter = &intel_idle, 618 .enter_freeze = intel_idle_freeze, }, 619 { 620 .name = "C6-ATM", 621 .desc = "MWAIT 0x52", 622 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED, 623 .exit_latency = 140, 624 .target_residency = 560, 625 .enter = &intel_idle, 626 .enter_freeze = intel_idle_freeze, }, 627 { 628 .enter = NULL } 629}; 630static struct cpuidle_state avn_cstates[] = { 631 { 632 .name = "C1-AVN", 633 .desc = "MWAIT 0x00", 634 .flags = MWAIT2flg(0x00), 635 .exit_latency = 2, 636 .target_residency = 2, 637 .enter = &intel_idle, 638 .enter_freeze = intel_idle_freeze, }, 639 { 640 .name = "C6-AVN", 641 .desc = "MWAIT 0x51", 642 .flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED, 643 .exit_latency = 15, 644 .target_residency = 45, 645 .enter = &intel_idle, 646 .enter_freeze = intel_idle_freeze, }, 647 { 648 .enter = NULL } 649}; 650 651/** 652 * intel_idle 653 * @dev: cpuidle_device 654 * @drv: cpuidle driver 655 * @index: index of cpuidle state 656 * 657 * Must be called under local_irq_disable(). 658 */ 659static int intel_idle(struct cpuidle_device *dev, 660 struct cpuidle_driver *drv, int index) 661{ 662 unsigned long ecx = 1; /* break on interrupt flag */ 663 struct cpuidle_state *state = &drv->states[index]; 664 unsigned long eax = flg2MWAIT(state->flags); 665 unsigned int cstate; 666 int cpu = smp_processor_id(); 667 668 cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1; 669 670 /* 671 * leave_mm() to avoid costly and often unnecessary wakeups 672 * for flushing the user TLB's associated with the active mm. 673 */ 674 if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED) 675 leave_mm(cpu); 676 677 if (!(lapic_timer_reliable_states & (1 << (cstate)))) 678 tick_broadcast_enter(); 679 680 mwait_idle_with_hints(eax, ecx); 681 682 if (!(lapic_timer_reliable_states & (1 << (cstate)))) 683 tick_broadcast_exit(); 684 685 return index; 686} 687 688/** 689 * intel_idle_freeze - simplified "enter" callback routine for suspend-to-idle 690 * @dev: cpuidle_device 691 * @drv: cpuidle driver 692 * @index: state index 693 */ 694static void intel_idle_freeze(struct cpuidle_device *dev, 695 struct cpuidle_driver *drv, int index) 696{ 697 unsigned long ecx = 1; /* break on interrupt flag */ 698 unsigned long eax = flg2MWAIT(drv->states[index].flags); 699 700 mwait_idle_with_hints(eax, ecx); 701} 702 703static void __setup_broadcast_timer(void *arg) 704{ 705 unsigned long on = (unsigned long)arg; 706 707 if (on) 708 tick_broadcast_enable(); 709 else 710 tick_broadcast_disable(); 711} 712 713static int cpu_hotplug_notify(struct notifier_block *n, 714 unsigned long action, void *hcpu) 715{ 716 int hotcpu = (unsigned long)hcpu; 717 struct cpuidle_device *dev; 718 719 switch (action & ~CPU_TASKS_FROZEN) { 720 case CPU_ONLINE: 721 722 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) 723 smp_call_function_single(hotcpu, __setup_broadcast_timer, 724 (void *)true, 1); 725 726 /* 727 * Some systems can hotplug a cpu at runtime after 728 * the kernel has booted, we have to initialize the 729 * driver in this case 730 */ 731 dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu); 732 if (!dev->registered) 733 intel_idle_cpu_init(hotcpu); 734 735 break; 736 } 737 return NOTIFY_OK; 738} 739 740static struct notifier_block cpu_hotplug_notifier = { 741 .notifier_call = cpu_hotplug_notify, 742}; 743 744static void auto_demotion_disable(void *dummy) 745{ 746 unsigned long long msr_bits; 747 748 rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits); 749 msr_bits &= ~(icpu->auto_demotion_disable_flags); 750 wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits); 751} 752static void c1e_promotion_disable(void *dummy) 753{ 754 unsigned long long msr_bits; 755 756 rdmsrl(MSR_IA32_POWER_CTL, msr_bits); 757 msr_bits &= ~0x2; 758 wrmsrl(MSR_IA32_POWER_CTL, msr_bits); 759} 760 761static const struct idle_cpu idle_cpu_nehalem = { 762 .state_table = nehalem_cstates, 763 .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE, 764 .disable_promotion_to_c1e = true, 765}; 766 767static const struct idle_cpu idle_cpu_atom = { 768 .state_table = atom_cstates, 769}; 770 771static const struct idle_cpu idle_cpu_lincroft = { 772 .state_table = atom_cstates, 773 .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE, 774}; 775 776static const struct idle_cpu idle_cpu_snb = { 777 .state_table = snb_cstates, 778 .disable_promotion_to_c1e = true, 779}; 780 781static const struct idle_cpu idle_cpu_byt = { 782 .state_table = byt_cstates, 783 .disable_promotion_to_c1e = true, 784 .byt_auto_demotion_disable_flag = true, 785}; 786 787static const struct idle_cpu idle_cpu_cht = { 788 .state_table = cht_cstates, 789 .disable_promotion_to_c1e = true, 790 .byt_auto_demotion_disable_flag = true, 791}; 792 793static const struct idle_cpu idle_cpu_ivb = { 794 .state_table = ivb_cstates, 795 .disable_promotion_to_c1e = true, 796}; 797 798static const struct idle_cpu idle_cpu_ivt = { 799 .state_table = ivt_cstates, 800 .disable_promotion_to_c1e = true, 801}; 802 803static const struct idle_cpu idle_cpu_hsw = { 804 .state_table = hsw_cstates, 805 .disable_promotion_to_c1e = true, 806}; 807 808static const struct idle_cpu idle_cpu_bdw = { 809 .state_table = bdw_cstates, 810 .disable_promotion_to_c1e = true, 811}; 812 813static const struct idle_cpu idle_cpu_avn = { 814 .state_table = avn_cstates, 815 .disable_promotion_to_c1e = true, 816}; 817 818#define ICPU(model, cpu) \ 819 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu } 820 821static const struct x86_cpu_id intel_idle_ids[] __initconst = { 822 ICPU(0x1a, idle_cpu_nehalem), 823 ICPU(0x1e, idle_cpu_nehalem), 824 ICPU(0x1f, idle_cpu_nehalem), 825 ICPU(0x25, idle_cpu_nehalem), 826 ICPU(0x2c, idle_cpu_nehalem), 827 ICPU(0x2e, idle_cpu_nehalem), 828 ICPU(0x1c, idle_cpu_atom), 829 ICPU(0x26, idle_cpu_lincroft), 830 ICPU(0x2f, idle_cpu_nehalem), 831 ICPU(0x2a, idle_cpu_snb), 832 ICPU(0x2d, idle_cpu_snb), 833 ICPU(0x36, idle_cpu_atom), 834 ICPU(0x37, idle_cpu_byt), 835 ICPU(0x4c, idle_cpu_cht), 836 ICPU(0x3a, idle_cpu_ivb), 837 ICPU(0x3e, idle_cpu_ivt), 838 ICPU(0x3c, idle_cpu_hsw), 839 ICPU(0x3f, idle_cpu_hsw), 840 ICPU(0x45, idle_cpu_hsw), 841 ICPU(0x46, idle_cpu_hsw), 842 ICPU(0x4d, idle_cpu_avn), 843 ICPU(0x3d, idle_cpu_bdw), 844 ICPU(0x47, idle_cpu_bdw), 845 ICPU(0x4f, idle_cpu_bdw), 846 ICPU(0x56, idle_cpu_bdw), 847 {} 848}; 849MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids); 850 851/* 852 * intel_idle_probe() 853 */ 854static int __init intel_idle_probe(void) 855{ 856 unsigned int eax, ebx, ecx; 857 const struct x86_cpu_id *id; 858 859 if (max_cstate == 0) { 860 pr_debug(PREFIX "disabled\n"); 861 return -EPERM; 862 } 863 864 id = x86_match_cpu(intel_idle_ids); 865 if (!id) { 866 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && 867 boot_cpu_data.x86 == 6) 868 pr_debug(PREFIX "does not run on family %d model %d\n", 869 boot_cpu_data.x86, boot_cpu_data.x86_model); 870 return -ENODEV; 871 } 872 873 if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) 874 return -ENODEV; 875 876 cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates); 877 878 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) || 879 !(ecx & CPUID5_ECX_INTERRUPT_BREAK) || 880 !mwait_substates) 881 return -ENODEV; 882 883 pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates); 884 885 icpu = (const struct idle_cpu *)id->driver_data; 886 cpuidle_state_table = icpu->state_table; 887 888 if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */ 889 lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE; 890 else 891 on_each_cpu(__setup_broadcast_timer, (void *)true, 1); 892 893 pr_debug(PREFIX "v" INTEL_IDLE_VERSION 894 " model 0x%X\n", boot_cpu_data.x86_model); 895 896 pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n", 897 lapic_timer_reliable_states); 898 return 0; 899} 900 901/* 902 * intel_idle_cpuidle_devices_uninit() 903 * unregister, free cpuidle_devices 904 */ 905static void intel_idle_cpuidle_devices_uninit(void) 906{ 907 int i; 908 struct cpuidle_device *dev; 909 910 for_each_online_cpu(i) { 911 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i); 912 cpuidle_unregister_device(dev); 913 } 914 915 free_percpu(intel_idle_cpuidle_devices); 916 return; 917} 918 919/* 920 * intel_idle_state_table_update() 921 * 922 * Update the default state_table for this CPU-id 923 * 924 * Currently used to access tuned IVT multi-socket targets 925 * Assumption: num_sockets == (max_package_num + 1) 926 */ 927void intel_idle_state_table_update(void) 928{ 929 /* IVT uses a different table for 1-2, 3-4, and > 4 sockets */ 930 if (boot_cpu_data.x86_model == 0x3e) { /* IVT */ 931 int cpu, package_num, num_sockets = 1; 932 933 for_each_online_cpu(cpu) { 934 package_num = topology_physical_package_id(cpu); 935 if (package_num + 1 > num_sockets) { 936 num_sockets = package_num + 1; 937 938 if (num_sockets > 4) { 939 cpuidle_state_table = ivt_cstates_8s; 940 return; 941 } 942 } 943 } 944 945 if (num_sockets > 2) 946 cpuidle_state_table = ivt_cstates_4s; 947 /* else, 1 and 2 socket systems use default ivt_cstates */ 948 } 949 return; 950} 951 952/* 953 * intel_idle_cpuidle_driver_init() 954 * allocate, initialize cpuidle_states 955 */ 956static int __init intel_idle_cpuidle_driver_init(void) 957{ 958 int cstate; 959 struct cpuidle_driver *drv = &intel_idle_driver; 960 961 intel_idle_state_table_update(); 962 963 drv->state_count = 1; 964 965 for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) { 966 int num_substates, mwait_hint, mwait_cstate; 967 968 if (cpuidle_state_table[cstate].enter == NULL) 969 break; 970 971 if (cstate + 1 > max_cstate) { 972 printk(PREFIX "max_cstate %d reached\n", 973 max_cstate); 974 break; 975 } 976 977 mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags); 978 mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint); 979 980 /* number of sub-states for this state in CPUID.MWAIT */ 981 num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4)) 982 & MWAIT_SUBSTATE_MASK; 983 984 /* if NO sub-states for this state in CPUID, skip it */ 985 if (num_substates == 0) 986 continue; 987 988 if (((mwait_cstate + 1) > 2) && 989 !boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 990 mark_tsc_unstable("TSC halts in idle" 991 " states deeper than C2"); 992 993 drv->states[drv->state_count] = /* structure copy */ 994 cpuidle_state_table[cstate]; 995 996 drv->state_count += 1; 997 } 998 999 if (icpu->auto_demotion_disable_flags) 1000 on_each_cpu(auto_demotion_disable, NULL, 1); 1001 1002 if (icpu->byt_auto_demotion_disable_flag) { 1003 wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0); 1004 wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0); 1005 } 1006 1007 if (icpu->disable_promotion_to_c1e) /* each-cpu is redundant */ 1008 on_each_cpu(c1e_promotion_disable, NULL, 1); 1009 1010 return 0; 1011} 1012 1013 1014/* 1015 * intel_idle_cpu_init() 1016 * allocate, initialize, register cpuidle_devices 1017 * @cpu: cpu/core to initialize 1018 */ 1019static int intel_idle_cpu_init(int cpu) 1020{ 1021 struct cpuidle_device *dev; 1022 1023 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu); 1024 1025 dev->cpu = cpu; 1026 1027 if (cpuidle_register_device(dev)) { 1028 pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu); 1029 intel_idle_cpuidle_devices_uninit(); 1030 return -EIO; 1031 } 1032 1033 if (icpu->auto_demotion_disable_flags) 1034 smp_call_function_single(cpu, auto_demotion_disable, NULL, 1); 1035 1036 if (icpu->disable_promotion_to_c1e) 1037 smp_call_function_single(cpu, c1e_promotion_disable, NULL, 1); 1038 1039 return 0; 1040} 1041 1042static int __init intel_idle_init(void) 1043{ 1044 int retval, i; 1045 1046 /* Do not load intel_idle at all for now if idle= is passed */ 1047 if (boot_option_idle_override != IDLE_NO_OVERRIDE) 1048 return -ENODEV; 1049 1050 retval = intel_idle_probe(); 1051 if (retval) 1052 return retval; 1053 1054 intel_idle_cpuidle_driver_init(); 1055 retval = cpuidle_register_driver(&intel_idle_driver); 1056 if (retval) { 1057 struct cpuidle_driver *drv = cpuidle_get_driver(); 1058 printk(KERN_DEBUG PREFIX "intel_idle yielding to %s", 1059 drv ? drv->name : "none"); 1060 return retval; 1061 } 1062 1063 intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device); 1064 if (intel_idle_cpuidle_devices == NULL) 1065 return -ENOMEM; 1066 1067 cpu_notifier_register_begin(); 1068 1069 for_each_online_cpu(i) { 1070 retval = intel_idle_cpu_init(i); 1071 if (retval) { 1072 cpu_notifier_register_done(); 1073 cpuidle_unregister_driver(&intel_idle_driver); 1074 return retval; 1075 } 1076 } 1077 __register_cpu_notifier(&cpu_hotplug_notifier); 1078 1079 cpu_notifier_register_done(); 1080 1081 return 0; 1082} 1083 1084static void __exit intel_idle_exit(void) 1085{ 1086 intel_idle_cpuidle_devices_uninit(); 1087 cpuidle_unregister_driver(&intel_idle_driver); 1088 1089 cpu_notifier_register_begin(); 1090 1091 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) 1092 on_each_cpu(__setup_broadcast_timer, (void *)false, 1); 1093 __unregister_cpu_notifier(&cpu_hotplug_notifier); 1094 1095 cpu_notifier_register_done(); 1096 1097 return; 1098} 1099 1100module_init(intel_idle_init); 1101module_exit(intel_idle_exit); 1102 1103module_param(max_cstate, int, 0444); 1104 1105MODULE_AUTHOR("Len Brown <len.brown@intel.com>"); 1106MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION); 1107MODULE_LICENSE("GPL"); 1108