mm: vma_adjust: remove superfluous check for next not NULL
[linux/fpc-iii.git] / drivers / idle / intel_idle.c
blob67ec58f9ef99f7c2fbc2115a8d6e8804a37327e1
1 /*
2 * intel_idle.c - native hardware idle loop for modern Intel processors
4 * Copyright (c) 2013, Intel Corporation.
5 * Len Brown <len.brown@intel.com>
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.
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.
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.
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.
29 * Design Assumptions
31 * All CPUs have same idle states as boot CPU
33 * Chipset BM_STS (bus master status) bit is a NOP
34 * for preventing entry into deep C-stats
38 * Known limitations
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.
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.
51 /* un-comment DEBUG to enable pr_debug() statements */
52 #define DEBUG
54 #include <linux/kernel.h>
55 #include <linux/cpuidle.h>
56 #include <linux/tick.h>
57 #include <trace/events/power.h>
58 #include <linux/sched.h>
59 #include <linux/notifier.h>
60 #include <linux/cpu.h>
61 #include <linux/moduleparam.h>
62 #include <asm/cpu_device_id.h>
63 #include <asm/intel-family.h>
64 #include <asm/mwait.h>
65 #include <asm/msr.h>
67 #define INTEL_IDLE_VERSION "0.4.1"
68 #define PREFIX "intel_idle: "
70 static struct cpuidle_driver intel_idle_driver = {
71 .name = "intel_idle",
72 .owner = THIS_MODULE,
74 /* intel_idle.max_cstate=0 disables driver */
75 static int max_cstate = CPUIDLE_STATE_MAX - 1;
77 static unsigned int mwait_substates;
79 #define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
80 /* Reliable LAPIC Timer States, bit 1 for C1 etc. */
81 static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */
83 struct idle_cpu {
84 struct cpuidle_state *state_table;
87 * Hardware C-state auto-demotion may not always be optimal.
88 * Indicate which enable bits to clear here.
90 unsigned long auto_demotion_disable_flags;
91 bool byt_auto_demotion_disable_flag;
92 bool disable_promotion_to_c1e;
95 static const struct idle_cpu *icpu;
96 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
97 static int intel_idle(struct cpuidle_device *dev,
98 struct cpuidle_driver *drv, int index);
99 static void intel_idle_freeze(struct cpuidle_device *dev,
100 struct cpuidle_driver *drv, int index);
101 static int intel_idle_cpu_init(int cpu);
103 static struct cpuidle_state *cpuidle_state_table;
106 * Set this flag for states where the HW flushes the TLB for us
107 * and so we don't need cross-calls to keep it consistent.
108 * If this flag is set, SW flushes the TLB, so even if the
109 * HW doesn't do the flushing, this flag is safe to use.
111 #define CPUIDLE_FLAG_TLB_FLUSHED 0x10000
114 * MWAIT takes an 8-bit "hint" in EAX "suggesting"
115 * the C-state (top nibble) and sub-state (bottom nibble)
116 * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
118 * We store the hint at the top of our "flags" for each state.
120 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
121 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
124 * States are indexed by the cstate number,
125 * which is also the index into the MWAIT hint array.
126 * Thus C0 is a dummy.
128 static struct cpuidle_state nehalem_cstates[] = {
130 .name = "C1-NHM",
131 .desc = "MWAIT 0x00",
132 .flags = MWAIT2flg(0x00),
133 .exit_latency = 3,
134 .target_residency = 6,
135 .enter = &intel_idle,
136 .enter_freeze = intel_idle_freeze, },
138 .name = "C1E-NHM",
139 .desc = "MWAIT 0x01",
140 .flags = MWAIT2flg(0x01),
141 .exit_latency = 10,
142 .target_residency = 20,
143 .enter = &intel_idle,
144 .enter_freeze = intel_idle_freeze, },
146 .name = "C3-NHM",
147 .desc = "MWAIT 0x10",
148 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
149 .exit_latency = 20,
150 .target_residency = 80,
151 .enter = &intel_idle,
152 .enter_freeze = intel_idle_freeze, },
154 .name = "C6-NHM",
155 .desc = "MWAIT 0x20",
156 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
157 .exit_latency = 200,
158 .target_residency = 800,
159 .enter = &intel_idle,
160 .enter_freeze = intel_idle_freeze, },
162 .enter = NULL }
165 static struct cpuidle_state snb_cstates[] = {
167 .name = "C1-SNB",
168 .desc = "MWAIT 0x00",
169 .flags = MWAIT2flg(0x00),
170 .exit_latency = 2,
171 .target_residency = 2,
172 .enter = &intel_idle,
173 .enter_freeze = intel_idle_freeze, },
175 .name = "C1E-SNB",
176 .desc = "MWAIT 0x01",
177 .flags = MWAIT2flg(0x01),
178 .exit_latency = 10,
179 .target_residency = 20,
180 .enter = &intel_idle,
181 .enter_freeze = intel_idle_freeze, },
183 .name = "C3-SNB",
184 .desc = "MWAIT 0x10",
185 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
186 .exit_latency = 80,
187 .target_residency = 211,
188 .enter = &intel_idle,
189 .enter_freeze = intel_idle_freeze, },
191 .name = "C6-SNB",
192 .desc = "MWAIT 0x20",
193 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
194 .exit_latency = 104,
195 .target_residency = 345,
196 .enter = &intel_idle,
197 .enter_freeze = intel_idle_freeze, },
199 .name = "C7-SNB",
200 .desc = "MWAIT 0x30",
201 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
202 .exit_latency = 109,
203 .target_residency = 345,
204 .enter = &intel_idle,
205 .enter_freeze = intel_idle_freeze, },
207 .enter = NULL }
210 static struct cpuidle_state byt_cstates[] = {
212 .name = "C1-BYT",
213 .desc = "MWAIT 0x00",
214 .flags = MWAIT2flg(0x00),
215 .exit_latency = 1,
216 .target_residency = 1,
217 .enter = &intel_idle,
218 .enter_freeze = intel_idle_freeze, },
220 .name = "C6N-BYT",
221 .desc = "MWAIT 0x58",
222 .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
223 .exit_latency = 300,
224 .target_residency = 275,
225 .enter = &intel_idle,
226 .enter_freeze = intel_idle_freeze, },
228 .name = "C6S-BYT",
229 .desc = "MWAIT 0x52",
230 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
231 .exit_latency = 500,
232 .target_residency = 560,
233 .enter = &intel_idle,
234 .enter_freeze = intel_idle_freeze, },
236 .name = "C7-BYT",
237 .desc = "MWAIT 0x60",
238 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
239 .exit_latency = 1200,
240 .target_residency = 4000,
241 .enter = &intel_idle,
242 .enter_freeze = intel_idle_freeze, },
244 .name = "C7S-BYT",
245 .desc = "MWAIT 0x64",
246 .flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
247 .exit_latency = 10000,
248 .target_residency = 20000,
249 .enter = &intel_idle,
250 .enter_freeze = intel_idle_freeze, },
252 .enter = NULL }
255 static struct cpuidle_state cht_cstates[] = {
257 .name = "C1-CHT",
258 .desc = "MWAIT 0x00",
259 .flags = MWAIT2flg(0x00),
260 .exit_latency = 1,
261 .target_residency = 1,
262 .enter = &intel_idle,
263 .enter_freeze = intel_idle_freeze, },
265 .name = "C6N-CHT",
266 .desc = "MWAIT 0x58",
267 .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
268 .exit_latency = 80,
269 .target_residency = 275,
270 .enter = &intel_idle,
271 .enter_freeze = intel_idle_freeze, },
273 .name = "C6S-CHT",
274 .desc = "MWAIT 0x52",
275 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
276 .exit_latency = 200,
277 .target_residency = 560,
278 .enter = &intel_idle,
279 .enter_freeze = intel_idle_freeze, },
281 .name = "C7-CHT",
282 .desc = "MWAIT 0x60",
283 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
284 .exit_latency = 1200,
285 .target_residency = 4000,
286 .enter = &intel_idle,
287 .enter_freeze = intel_idle_freeze, },
289 .name = "C7S-CHT",
290 .desc = "MWAIT 0x64",
291 .flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
292 .exit_latency = 10000,
293 .target_residency = 20000,
294 .enter = &intel_idle,
295 .enter_freeze = intel_idle_freeze, },
297 .enter = NULL }
300 static struct cpuidle_state ivb_cstates[] = {
302 .name = "C1-IVB",
303 .desc = "MWAIT 0x00",
304 .flags = MWAIT2flg(0x00),
305 .exit_latency = 1,
306 .target_residency = 1,
307 .enter = &intel_idle,
308 .enter_freeze = intel_idle_freeze, },
310 .name = "C1E-IVB",
311 .desc = "MWAIT 0x01",
312 .flags = MWAIT2flg(0x01),
313 .exit_latency = 10,
314 .target_residency = 20,
315 .enter = &intel_idle,
316 .enter_freeze = intel_idle_freeze, },
318 .name = "C3-IVB",
319 .desc = "MWAIT 0x10",
320 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
321 .exit_latency = 59,
322 .target_residency = 156,
323 .enter = &intel_idle,
324 .enter_freeze = intel_idle_freeze, },
326 .name = "C6-IVB",
327 .desc = "MWAIT 0x20",
328 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
329 .exit_latency = 80,
330 .target_residency = 300,
331 .enter = &intel_idle,
332 .enter_freeze = intel_idle_freeze, },
334 .name = "C7-IVB",
335 .desc = "MWAIT 0x30",
336 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
337 .exit_latency = 87,
338 .target_residency = 300,
339 .enter = &intel_idle,
340 .enter_freeze = intel_idle_freeze, },
342 .enter = NULL }
345 static struct cpuidle_state ivt_cstates[] = {
347 .name = "C1-IVT",
348 .desc = "MWAIT 0x00",
349 .flags = MWAIT2flg(0x00),
350 .exit_latency = 1,
351 .target_residency = 1,
352 .enter = &intel_idle,
353 .enter_freeze = intel_idle_freeze, },
355 .name = "C1E-IVT",
356 .desc = "MWAIT 0x01",
357 .flags = MWAIT2flg(0x01),
358 .exit_latency = 10,
359 .target_residency = 80,
360 .enter = &intel_idle,
361 .enter_freeze = intel_idle_freeze, },
363 .name = "C3-IVT",
364 .desc = "MWAIT 0x10",
365 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
366 .exit_latency = 59,
367 .target_residency = 156,
368 .enter = &intel_idle,
369 .enter_freeze = intel_idle_freeze, },
371 .name = "C6-IVT",
372 .desc = "MWAIT 0x20",
373 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
374 .exit_latency = 82,
375 .target_residency = 300,
376 .enter = &intel_idle,
377 .enter_freeze = intel_idle_freeze, },
379 .enter = NULL }
382 static struct cpuidle_state ivt_cstates_4s[] = {
384 .name = "C1-IVT-4S",
385 .desc = "MWAIT 0x00",
386 .flags = MWAIT2flg(0x00),
387 .exit_latency = 1,
388 .target_residency = 1,
389 .enter = &intel_idle,
390 .enter_freeze = intel_idle_freeze, },
392 .name = "C1E-IVT-4S",
393 .desc = "MWAIT 0x01",
394 .flags = MWAIT2flg(0x01),
395 .exit_latency = 10,
396 .target_residency = 250,
397 .enter = &intel_idle,
398 .enter_freeze = intel_idle_freeze, },
400 .name = "C3-IVT-4S",
401 .desc = "MWAIT 0x10",
402 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
403 .exit_latency = 59,
404 .target_residency = 300,
405 .enter = &intel_idle,
406 .enter_freeze = intel_idle_freeze, },
408 .name = "C6-IVT-4S",
409 .desc = "MWAIT 0x20",
410 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
411 .exit_latency = 84,
412 .target_residency = 400,
413 .enter = &intel_idle,
414 .enter_freeze = intel_idle_freeze, },
416 .enter = NULL }
419 static struct cpuidle_state ivt_cstates_8s[] = {
421 .name = "C1-IVT-8S",
422 .desc = "MWAIT 0x00",
423 .flags = MWAIT2flg(0x00),
424 .exit_latency = 1,
425 .target_residency = 1,
426 .enter = &intel_idle,
427 .enter_freeze = intel_idle_freeze, },
429 .name = "C1E-IVT-8S",
430 .desc = "MWAIT 0x01",
431 .flags = MWAIT2flg(0x01),
432 .exit_latency = 10,
433 .target_residency = 500,
434 .enter = &intel_idle,
435 .enter_freeze = intel_idle_freeze, },
437 .name = "C3-IVT-8S",
438 .desc = "MWAIT 0x10",
439 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
440 .exit_latency = 59,
441 .target_residency = 600,
442 .enter = &intel_idle,
443 .enter_freeze = intel_idle_freeze, },
445 .name = "C6-IVT-8S",
446 .desc = "MWAIT 0x20",
447 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
448 .exit_latency = 88,
449 .target_residency = 700,
450 .enter = &intel_idle,
451 .enter_freeze = intel_idle_freeze, },
453 .enter = NULL }
456 static struct cpuidle_state hsw_cstates[] = {
458 .name = "C1-HSW",
459 .desc = "MWAIT 0x00",
460 .flags = MWAIT2flg(0x00),
461 .exit_latency = 2,
462 .target_residency = 2,
463 .enter = &intel_idle,
464 .enter_freeze = intel_idle_freeze, },
466 .name = "C1E-HSW",
467 .desc = "MWAIT 0x01",
468 .flags = MWAIT2flg(0x01),
469 .exit_latency = 10,
470 .target_residency = 20,
471 .enter = &intel_idle,
472 .enter_freeze = intel_idle_freeze, },
474 .name = "C3-HSW",
475 .desc = "MWAIT 0x10",
476 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
477 .exit_latency = 33,
478 .target_residency = 100,
479 .enter = &intel_idle,
480 .enter_freeze = intel_idle_freeze, },
482 .name = "C6-HSW",
483 .desc = "MWAIT 0x20",
484 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
485 .exit_latency = 133,
486 .target_residency = 400,
487 .enter = &intel_idle,
488 .enter_freeze = intel_idle_freeze, },
490 .name = "C7s-HSW",
491 .desc = "MWAIT 0x32",
492 .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
493 .exit_latency = 166,
494 .target_residency = 500,
495 .enter = &intel_idle,
496 .enter_freeze = intel_idle_freeze, },
498 .name = "C8-HSW",
499 .desc = "MWAIT 0x40",
500 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
501 .exit_latency = 300,
502 .target_residency = 900,
503 .enter = &intel_idle,
504 .enter_freeze = intel_idle_freeze, },
506 .name = "C9-HSW",
507 .desc = "MWAIT 0x50",
508 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
509 .exit_latency = 600,
510 .target_residency = 1800,
511 .enter = &intel_idle,
512 .enter_freeze = intel_idle_freeze, },
514 .name = "C10-HSW",
515 .desc = "MWAIT 0x60",
516 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
517 .exit_latency = 2600,
518 .target_residency = 7700,
519 .enter = &intel_idle,
520 .enter_freeze = intel_idle_freeze, },
522 .enter = NULL }
524 static struct cpuidle_state bdw_cstates[] = {
526 .name = "C1-BDW",
527 .desc = "MWAIT 0x00",
528 .flags = MWAIT2flg(0x00),
529 .exit_latency = 2,
530 .target_residency = 2,
531 .enter = &intel_idle,
532 .enter_freeze = intel_idle_freeze, },
534 .name = "C1E-BDW",
535 .desc = "MWAIT 0x01",
536 .flags = MWAIT2flg(0x01),
537 .exit_latency = 10,
538 .target_residency = 20,
539 .enter = &intel_idle,
540 .enter_freeze = intel_idle_freeze, },
542 .name = "C3-BDW",
543 .desc = "MWAIT 0x10",
544 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
545 .exit_latency = 40,
546 .target_residency = 100,
547 .enter = &intel_idle,
548 .enter_freeze = intel_idle_freeze, },
550 .name = "C6-BDW",
551 .desc = "MWAIT 0x20",
552 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
553 .exit_latency = 133,
554 .target_residency = 400,
555 .enter = &intel_idle,
556 .enter_freeze = intel_idle_freeze, },
558 .name = "C7s-BDW",
559 .desc = "MWAIT 0x32",
560 .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
561 .exit_latency = 166,
562 .target_residency = 500,
563 .enter = &intel_idle,
564 .enter_freeze = intel_idle_freeze, },
566 .name = "C8-BDW",
567 .desc = "MWAIT 0x40",
568 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
569 .exit_latency = 300,
570 .target_residency = 900,
571 .enter = &intel_idle,
572 .enter_freeze = intel_idle_freeze, },
574 .name = "C9-BDW",
575 .desc = "MWAIT 0x50",
576 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
577 .exit_latency = 600,
578 .target_residency = 1800,
579 .enter = &intel_idle,
580 .enter_freeze = intel_idle_freeze, },
582 .name = "C10-BDW",
583 .desc = "MWAIT 0x60",
584 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
585 .exit_latency = 2600,
586 .target_residency = 7700,
587 .enter = &intel_idle,
588 .enter_freeze = intel_idle_freeze, },
590 .enter = NULL }
593 static struct cpuidle_state skl_cstates[] = {
595 .name = "C1-SKL",
596 .desc = "MWAIT 0x00",
597 .flags = MWAIT2flg(0x00),
598 .exit_latency = 2,
599 .target_residency = 2,
600 .enter = &intel_idle,
601 .enter_freeze = intel_idle_freeze, },
603 .name = "C1E-SKL",
604 .desc = "MWAIT 0x01",
605 .flags = MWAIT2flg(0x01),
606 .exit_latency = 10,
607 .target_residency = 20,
608 .enter = &intel_idle,
609 .enter_freeze = intel_idle_freeze, },
611 .name = "C3-SKL",
612 .desc = "MWAIT 0x10",
613 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
614 .exit_latency = 70,
615 .target_residency = 100,
616 .enter = &intel_idle,
617 .enter_freeze = intel_idle_freeze, },
619 .name = "C6-SKL",
620 .desc = "MWAIT 0x20",
621 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
622 .exit_latency = 85,
623 .target_residency = 200,
624 .enter = &intel_idle,
625 .enter_freeze = intel_idle_freeze, },
627 .name = "C7s-SKL",
628 .desc = "MWAIT 0x33",
629 .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
630 .exit_latency = 124,
631 .target_residency = 800,
632 .enter = &intel_idle,
633 .enter_freeze = intel_idle_freeze, },
635 .name = "C8-SKL",
636 .desc = "MWAIT 0x40",
637 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
638 .exit_latency = 200,
639 .target_residency = 800,
640 .enter = &intel_idle,
641 .enter_freeze = intel_idle_freeze, },
643 .name = "C9-SKL",
644 .desc = "MWAIT 0x50",
645 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
646 .exit_latency = 480,
647 .target_residency = 5000,
648 .enter = &intel_idle,
649 .enter_freeze = intel_idle_freeze, },
651 .name = "C10-SKL",
652 .desc = "MWAIT 0x60",
653 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
654 .exit_latency = 890,
655 .target_residency = 5000,
656 .enter = &intel_idle,
657 .enter_freeze = intel_idle_freeze, },
659 .enter = NULL }
662 static struct cpuidle_state skx_cstates[] = {
664 .name = "C1-SKX",
665 .desc = "MWAIT 0x00",
666 .flags = MWAIT2flg(0x00),
667 .exit_latency = 2,
668 .target_residency = 2,
669 .enter = &intel_idle,
670 .enter_freeze = intel_idle_freeze, },
672 .name = "C1E-SKX",
673 .desc = "MWAIT 0x01",
674 .flags = MWAIT2flg(0x01),
675 .exit_latency = 10,
676 .target_residency = 20,
677 .enter = &intel_idle,
678 .enter_freeze = intel_idle_freeze, },
680 .name = "C6-SKX",
681 .desc = "MWAIT 0x20",
682 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
683 .exit_latency = 133,
684 .target_residency = 600,
685 .enter = &intel_idle,
686 .enter_freeze = intel_idle_freeze, },
688 .enter = NULL }
691 static struct cpuidle_state atom_cstates[] = {
693 .name = "C1E-ATM",
694 .desc = "MWAIT 0x00",
695 .flags = MWAIT2flg(0x00),
696 .exit_latency = 10,
697 .target_residency = 20,
698 .enter = &intel_idle,
699 .enter_freeze = intel_idle_freeze, },
701 .name = "C2-ATM",
702 .desc = "MWAIT 0x10",
703 .flags = MWAIT2flg(0x10),
704 .exit_latency = 20,
705 .target_residency = 80,
706 .enter = &intel_idle,
707 .enter_freeze = intel_idle_freeze, },
709 .name = "C4-ATM",
710 .desc = "MWAIT 0x30",
711 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
712 .exit_latency = 100,
713 .target_residency = 400,
714 .enter = &intel_idle,
715 .enter_freeze = intel_idle_freeze, },
717 .name = "C6-ATM",
718 .desc = "MWAIT 0x52",
719 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
720 .exit_latency = 140,
721 .target_residency = 560,
722 .enter = &intel_idle,
723 .enter_freeze = intel_idle_freeze, },
725 .enter = NULL }
727 static struct cpuidle_state avn_cstates[] = {
729 .name = "C1-AVN",
730 .desc = "MWAIT 0x00",
731 .flags = MWAIT2flg(0x00),
732 .exit_latency = 2,
733 .target_residency = 2,
734 .enter = &intel_idle,
735 .enter_freeze = intel_idle_freeze, },
737 .name = "C6-AVN",
738 .desc = "MWAIT 0x51",
739 .flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
740 .exit_latency = 15,
741 .target_residency = 45,
742 .enter = &intel_idle,
743 .enter_freeze = intel_idle_freeze, },
745 .enter = NULL }
747 static struct cpuidle_state knl_cstates[] = {
749 .name = "C1-KNL",
750 .desc = "MWAIT 0x00",
751 .flags = MWAIT2flg(0x00),
752 .exit_latency = 1,
753 .target_residency = 2,
754 .enter = &intel_idle,
755 .enter_freeze = intel_idle_freeze },
757 .name = "C6-KNL",
758 .desc = "MWAIT 0x10",
759 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
760 .exit_latency = 120,
761 .target_residency = 500,
762 .enter = &intel_idle,
763 .enter_freeze = intel_idle_freeze },
765 .enter = NULL }
768 static struct cpuidle_state bxt_cstates[] = {
770 .name = "C1-BXT",
771 .desc = "MWAIT 0x00",
772 .flags = MWAIT2flg(0x00),
773 .exit_latency = 2,
774 .target_residency = 2,
775 .enter = &intel_idle,
776 .enter_freeze = intel_idle_freeze, },
778 .name = "C1E-BXT",
779 .desc = "MWAIT 0x01",
780 .flags = MWAIT2flg(0x01),
781 .exit_latency = 10,
782 .target_residency = 20,
783 .enter = &intel_idle,
784 .enter_freeze = intel_idle_freeze, },
786 .name = "C6-BXT",
787 .desc = "MWAIT 0x20",
788 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
789 .exit_latency = 133,
790 .target_residency = 133,
791 .enter = &intel_idle,
792 .enter_freeze = intel_idle_freeze, },
794 .name = "C7s-BXT",
795 .desc = "MWAIT 0x31",
796 .flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
797 .exit_latency = 155,
798 .target_residency = 155,
799 .enter = &intel_idle,
800 .enter_freeze = intel_idle_freeze, },
802 .name = "C8-BXT",
803 .desc = "MWAIT 0x40",
804 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
805 .exit_latency = 1000,
806 .target_residency = 1000,
807 .enter = &intel_idle,
808 .enter_freeze = intel_idle_freeze, },
810 .name = "C9-BXT",
811 .desc = "MWAIT 0x50",
812 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
813 .exit_latency = 2000,
814 .target_residency = 2000,
815 .enter = &intel_idle,
816 .enter_freeze = intel_idle_freeze, },
818 .name = "C10-BXT",
819 .desc = "MWAIT 0x60",
820 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
821 .exit_latency = 10000,
822 .target_residency = 10000,
823 .enter = &intel_idle,
824 .enter_freeze = intel_idle_freeze, },
826 .enter = NULL }
829 static struct cpuidle_state dnv_cstates[] = {
831 .name = "C1-DNV",
832 .desc = "MWAIT 0x00",
833 .flags = MWAIT2flg(0x00),
834 .exit_latency = 2,
835 .target_residency = 2,
836 .enter = &intel_idle,
837 .enter_freeze = intel_idle_freeze, },
839 .name = "C1E-DNV",
840 .desc = "MWAIT 0x01",
841 .flags = MWAIT2flg(0x01),
842 .exit_latency = 10,
843 .target_residency = 20,
844 .enter = &intel_idle,
845 .enter_freeze = intel_idle_freeze, },
847 .name = "C6-DNV",
848 .desc = "MWAIT 0x20",
849 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
850 .exit_latency = 50,
851 .target_residency = 500,
852 .enter = &intel_idle,
853 .enter_freeze = intel_idle_freeze, },
855 .enter = NULL }
859 * intel_idle
860 * @dev: cpuidle_device
861 * @drv: cpuidle driver
862 * @index: index of cpuidle state
864 * Must be called under local_irq_disable().
866 static int intel_idle(struct cpuidle_device *dev,
867 struct cpuidle_driver *drv, int index)
869 unsigned long ecx = 1; /* break on interrupt flag */
870 struct cpuidle_state *state = &drv->states[index];
871 unsigned long eax = flg2MWAIT(state->flags);
872 unsigned int cstate;
873 int cpu = smp_processor_id();
875 cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
878 * leave_mm() to avoid costly and often unnecessary wakeups
879 * for flushing the user TLB's associated with the active mm.
881 if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
882 leave_mm(cpu);
884 if (!(lapic_timer_reliable_states & (1 << (cstate))))
885 tick_broadcast_enter();
887 mwait_idle_with_hints(eax, ecx);
889 if (!(lapic_timer_reliable_states & (1 << (cstate))))
890 tick_broadcast_exit();
892 return index;
896 * intel_idle_freeze - simplified "enter" callback routine for suspend-to-idle
897 * @dev: cpuidle_device
898 * @drv: cpuidle driver
899 * @index: state index
901 static void intel_idle_freeze(struct cpuidle_device *dev,
902 struct cpuidle_driver *drv, int index)
904 unsigned long ecx = 1; /* break on interrupt flag */
905 unsigned long eax = flg2MWAIT(drv->states[index].flags);
907 mwait_idle_with_hints(eax, ecx);
910 static void __setup_broadcast_timer(void *arg)
912 unsigned long on = (unsigned long)arg;
914 if (on)
915 tick_broadcast_enable();
916 else
917 tick_broadcast_disable();
920 static int cpu_hotplug_notify(struct notifier_block *n,
921 unsigned long action, void *hcpu)
923 int hotcpu = (unsigned long)hcpu;
924 struct cpuidle_device *dev;
926 switch (action & ~CPU_TASKS_FROZEN) {
927 case CPU_ONLINE:
929 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
930 smp_call_function_single(hotcpu, __setup_broadcast_timer,
931 (void *)true, 1);
934 * Some systems can hotplug a cpu at runtime after
935 * the kernel has booted, we have to initialize the
936 * driver in this case
938 dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
939 if (dev->registered)
940 break;
942 if (intel_idle_cpu_init(hotcpu))
943 return NOTIFY_BAD;
945 break;
947 return NOTIFY_OK;
950 static struct notifier_block cpu_hotplug_notifier = {
951 .notifier_call = cpu_hotplug_notify,
954 static void auto_demotion_disable(void *dummy)
956 unsigned long long msr_bits;
958 rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
959 msr_bits &= ~(icpu->auto_demotion_disable_flags);
960 wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
962 static void c1e_promotion_disable(void *dummy)
964 unsigned long long msr_bits;
966 rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
967 msr_bits &= ~0x2;
968 wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
971 static const struct idle_cpu idle_cpu_nehalem = {
972 .state_table = nehalem_cstates,
973 .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
974 .disable_promotion_to_c1e = true,
977 static const struct idle_cpu idle_cpu_atom = {
978 .state_table = atom_cstates,
981 static const struct idle_cpu idle_cpu_lincroft = {
982 .state_table = atom_cstates,
983 .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
986 static const struct idle_cpu idle_cpu_snb = {
987 .state_table = snb_cstates,
988 .disable_promotion_to_c1e = true,
991 static const struct idle_cpu idle_cpu_byt = {
992 .state_table = byt_cstates,
993 .disable_promotion_to_c1e = true,
994 .byt_auto_demotion_disable_flag = true,
997 static const struct idle_cpu idle_cpu_cht = {
998 .state_table = cht_cstates,
999 .disable_promotion_to_c1e = true,
1000 .byt_auto_demotion_disable_flag = true,
1003 static const struct idle_cpu idle_cpu_ivb = {
1004 .state_table = ivb_cstates,
1005 .disable_promotion_to_c1e = true,
1008 static const struct idle_cpu idle_cpu_ivt = {
1009 .state_table = ivt_cstates,
1010 .disable_promotion_to_c1e = true,
1013 static const struct idle_cpu idle_cpu_hsw = {
1014 .state_table = hsw_cstates,
1015 .disable_promotion_to_c1e = true,
1018 static const struct idle_cpu idle_cpu_bdw = {
1019 .state_table = bdw_cstates,
1020 .disable_promotion_to_c1e = true,
1023 static const struct idle_cpu idle_cpu_skl = {
1024 .state_table = skl_cstates,
1025 .disable_promotion_to_c1e = true,
1028 static const struct idle_cpu idle_cpu_skx = {
1029 .state_table = skx_cstates,
1030 .disable_promotion_to_c1e = true,
1033 static const struct idle_cpu idle_cpu_avn = {
1034 .state_table = avn_cstates,
1035 .disable_promotion_to_c1e = true,
1038 static const struct idle_cpu idle_cpu_knl = {
1039 .state_table = knl_cstates,
1042 static const struct idle_cpu idle_cpu_bxt = {
1043 .state_table = bxt_cstates,
1044 .disable_promotion_to_c1e = true,
1047 static const struct idle_cpu idle_cpu_dnv = {
1048 .state_table = dnv_cstates,
1049 .disable_promotion_to_c1e = true,
1052 #define ICPU(model, cpu) \
1053 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
1055 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1056 ICPU(INTEL_FAM6_NEHALEM_EP, idle_cpu_nehalem),
1057 ICPU(INTEL_FAM6_NEHALEM, idle_cpu_nehalem),
1058 ICPU(INTEL_FAM6_NEHALEM_G, idle_cpu_nehalem),
1059 ICPU(INTEL_FAM6_WESTMERE, idle_cpu_nehalem),
1060 ICPU(INTEL_FAM6_WESTMERE_EP, idle_cpu_nehalem),
1061 ICPU(INTEL_FAM6_NEHALEM_EX, idle_cpu_nehalem),
1062 ICPU(INTEL_FAM6_ATOM_PINEVIEW, idle_cpu_atom),
1063 ICPU(INTEL_FAM6_ATOM_LINCROFT, idle_cpu_lincroft),
1064 ICPU(INTEL_FAM6_WESTMERE_EX, idle_cpu_nehalem),
1065 ICPU(INTEL_FAM6_SANDYBRIDGE, idle_cpu_snb),
1066 ICPU(INTEL_FAM6_SANDYBRIDGE_X, idle_cpu_snb),
1067 ICPU(INTEL_FAM6_ATOM_CEDARVIEW, idle_cpu_atom),
1068 ICPU(INTEL_FAM6_ATOM_SILVERMONT1, idle_cpu_byt),
1069 ICPU(INTEL_FAM6_ATOM_AIRMONT, idle_cpu_cht),
1070 ICPU(INTEL_FAM6_IVYBRIDGE, idle_cpu_ivb),
1071 ICPU(INTEL_FAM6_IVYBRIDGE_X, idle_cpu_ivt),
1072 ICPU(INTEL_FAM6_HASWELL_CORE, idle_cpu_hsw),
1073 ICPU(INTEL_FAM6_HASWELL_X, idle_cpu_hsw),
1074 ICPU(INTEL_FAM6_HASWELL_ULT, idle_cpu_hsw),
1075 ICPU(INTEL_FAM6_HASWELL_GT3E, idle_cpu_hsw),
1076 ICPU(INTEL_FAM6_ATOM_SILVERMONT2, idle_cpu_avn),
1077 ICPU(INTEL_FAM6_BROADWELL_CORE, idle_cpu_bdw),
1078 ICPU(INTEL_FAM6_BROADWELL_GT3E, idle_cpu_bdw),
1079 ICPU(INTEL_FAM6_BROADWELL_X, idle_cpu_bdw),
1080 ICPU(INTEL_FAM6_BROADWELL_XEON_D, idle_cpu_bdw),
1081 ICPU(INTEL_FAM6_SKYLAKE_MOBILE, idle_cpu_skl),
1082 ICPU(INTEL_FAM6_SKYLAKE_DESKTOP, idle_cpu_skl),
1083 ICPU(INTEL_FAM6_KABYLAKE_MOBILE, idle_cpu_skl),
1084 ICPU(INTEL_FAM6_KABYLAKE_DESKTOP, idle_cpu_skl),
1085 ICPU(INTEL_FAM6_SKYLAKE_X, idle_cpu_skx),
1086 ICPU(INTEL_FAM6_XEON_PHI_KNL, idle_cpu_knl),
1087 ICPU(INTEL_FAM6_ATOM_GOLDMONT, idle_cpu_bxt),
1088 ICPU(INTEL_FAM6_ATOM_DENVERTON, idle_cpu_dnv),
1093 * intel_idle_probe()
1095 static int __init intel_idle_probe(void)
1097 unsigned int eax, ebx, ecx;
1098 const struct x86_cpu_id *id;
1100 if (max_cstate == 0) {
1101 pr_debug(PREFIX "disabled\n");
1102 return -EPERM;
1105 id = x86_match_cpu(intel_idle_ids);
1106 if (!id) {
1107 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
1108 boot_cpu_data.x86 == 6)
1109 pr_debug(PREFIX "does not run on family %d model %d\n",
1110 boot_cpu_data.x86, boot_cpu_data.x86_model);
1111 return -ENODEV;
1114 if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1115 return -ENODEV;
1117 cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1119 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1120 !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1121 !mwait_substates)
1122 return -ENODEV;
1124 pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
1126 icpu = (const struct idle_cpu *)id->driver_data;
1127 cpuidle_state_table = icpu->state_table;
1129 pr_debug(PREFIX "v" INTEL_IDLE_VERSION
1130 " model 0x%X\n", boot_cpu_data.x86_model);
1132 return 0;
1136 * intel_idle_cpuidle_devices_uninit()
1137 * Unregisters the cpuidle devices.
1139 static void intel_idle_cpuidle_devices_uninit(void)
1141 int i;
1142 struct cpuidle_device *dev;
1144 for_each_online_cpu(i) {
1145 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1146 cpuidle_unregister_device(dev);
1151 * ivt_idle_state_table_update(void)
1153 * Tune IVT multi-socket targets
1154 * Assumption: num_sockets == (max_package_num + 1)
1156 static void ivt_idle_state_table_update(void)
1158 /* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1159 int cpu, package_num, num_sockets = 1;
1161 for_each_online_cpu(cpu) {
1162 package_num = topology_physical_package_id(cpu);
1163 if (package_num + 1 > num_sockets) {
1164 num_sockets = package_num + 1;
1166 if (num_sockets > 4) {
1167 cpuidle_state_table = ivt_cstates_8s;
1168 return;
1173 if (num_sockets > 2)
1174 cpuidle_state_table = ivt_cstates_4s;
1176 /* else, 1 and 2 socket systems use default ivt_cstates */
1180 * Translate IRTL (Interrupt Response Time Limit) MSR to usec
1183 static unsigned int irtl_ns_units[] = {
1184 1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
1186 static unsigned long long irtl_2_usec(unsigned long long irtl)
1188 unsigned long long ns;
1190 if (!irtl)
1191 return 0;
1193 ns = irtl_ns_units[(irtl >> 10) & 0x7];
1195 return div64_u64((irtl & 0x3FF) * ns, 1000);
1198 * bxt_idle_state_table_update(void)
1200 * On BXT, we trust the IRTL to show the definitive maximum latency
1201 * We use the same value for target_residency.
1203 static void bxt_idle_state_table_update(void)
1205 unsigned long long msr;
1206 unsigned int usec;
1208 rdmsrl(MSR_PKGC6_IRTL, msr);
1209 usec = irtl_2_usec(msr);
1210 if (usec) {
1211 bxt_cstates[2].exit_latency = usec;
1212 bxt_cstates[2].target_residency = usec;
1215 rdmsrl(MSR_PKGC7_IRTL, msr);
1216 usec = irtl_2_usec(msr);
1217 if (usec) {
1218 bxt_cstates[3].exit_latency = usec;
1219 bxt_cstates[3].target_residency = usec;
1222 rdmsrl(MSR_PKGC8_IRTL, msr);
1223 usec = irtl_2_usec(msr);
1224 if (usec) {
1225 bxt_cstates[4].exit_latency = usec;
1226 bxt_cstates[4].target_residency = usec;
1229 rdmsrl(MSR_PKGC9_IRTL, msr);
1230 usec = irtl_2_usec(msr);
1231 if (usec) {
1232 bxt_cstates[5].exit_latency = usec;
1233 bxt_cstates[5].target_residency = usec;
1236 rdmsrl(MSR_PKGC10_IRTL, msr);
1237 usec = irtl_2_usec(msr);
1238 if (usec) {
1239 bxt_cstates[6].exit_latency = usec;
1240 bxt_cstates[6].target_residency = usec;
1245 * sklh_idle_state_table_update(void)
1247 * On SKL-H (model 0x5e) disable C8 and C9 if:
1248 * C10 is enabled and SGX disabled
1250 static void sklh_idle_state_table_update(void)
1252 unsigned long long msr;
1253 unsigned int eax, ebx, ecx, edx;
1256 /* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1257 if (max_cstate <= 7)
1258 return;
1260 /* if PC10 not present in CPUID.MWAIT.EDX */
1261 if ((mwait_substates & (0xF << 28)) == 0)
1262 return;
1264 rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr);
1266 /* PC10 is not enabled in PKG C-state limit */
1267 if ((msr & 0xF) != 8)
1268 return;
1270 ecx = 0;
1271 cpuid(7, &eax, &ebx, &ecx, &edx);
1273 /* if SGX is present */
1274 if (ebx & (1 << 2)) {
1276 rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
1278 /* if SGX is enabled */
1279 if (msr & (1 << 18))
1280 return;
1283 skl_cstates[5].disabled = 1; /* C8-SKL */
1284 skl_cstates[6].disabled = 1; /* C9-SKL */
1287 * intel_idle_state_table_update()
1289 * Update the default state_table for this CPU-id
1292 static void intel_idle_state_table_update(void)
1294 switch (boot_cpu_data.x86_model) {
1296 case INTEL_FAM6_IVYBRIDGE_X:
1297 ivt_idle_state_table_update();
1298 break;
1299 case INTEL_FAM6_ATOM_GOLDMONT:
1300 bxt_idle_state_table_update();
1301 break;
1302 case INTEL_FAM6_SKYLAKE_DESKTOP:
1303 sklh_idle_state_table_update();
1304 break;
1309 * intel_idle_cpuidle_driver_init()
1310 * allocate, initialize cpuidle_states
1312 static void __init intel_idle_cpuidle_driver_init(void)
1314 int cstate;
1315 struct cpuidle_driver *drv = &intel_idle_driver;
1317 intel_idle_state_table_update();
1319 drv->state_count = 1;
1321 for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1322 int num_substates, mwait_hint, mwait_cstate;
1324 if ((cpuidle_state_table[cstate].enter == NULL) &&
1325 (cpuidle_state_table[cstate].enter_freeze == NULL))
1326 break;
1328 if (cstate + 1 > max_cstate) {
1329 printk(PREFIX "max_cstate %d reached\n",
1330 max_cstate);
1331 break;
1334 mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1335 mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
1337 /* number of sub-states for this state in CPUID.MWAIT */
1338 num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
1339 & MWAIT_SUBSTATE_MASK;
1341 /* if NO sub-states for this state in CPUID, skip it */
1342 if (num_substates == 0)
1343 continue;
1345 /* if state marked as disabled, skip it */
1346 if (cpuidle_state_table[cstate].disabled != 0) {
1347 pr_debug(PREFIX "state %s is disabled",
1348 cpuidle_state_table[cstate].name);
1349 continue;
1353 if (((mwait_cstate + 1) > 2) &&
1354 !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1355 mark_tsc_unstable("TSC halts in idle"
1356 " states deeper than C2");
1358 drv->states[drv->state_count] = /* structure copy */
1359 cpuidle_state_table[cstate];
1361 drv->state_count += 1;
1364 if (icpu->byt_auto_demotion_disable_flag) {
1365 wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1366 wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1372 * intel_idle_cpu_init()
1373 * allocate, initialize, register cpuidle_devices
1374 * @cpu: cpu/core to initialize
1376 static int intel_idle_cpu_init(int cpu)
1378 struct cpuidle_device *dev;
1380 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1382 dev->cpu = cpu;
1384 if (cpuidle_register_device(dev)) {
1385 pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
1386 return -EIO;
1389 if (icpu->auto_demotion_disable_flags)
1390 smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
1392 if (icpu->disable_promotion_to_c1e)
1393 smp_call_function_single(cpu, c1e_promotion_disable, NULL, 1);
1395 return 0;
1398 static int __init intel_idle_init(void)
1400 int retval, i;
1402 /* Do not load intel_idle at all for now if idle= is passed */
1403 if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1404 return -ENODEV;
1406 retval = intel_idle_probe();
1407 if (retval)
1408 return retval;
1410 intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1411 if (intel_idle_cpuidle_devices == NULL)
1412 return -ENOMEM;
1414 intel_idle_cpuidle_driver_init();
1415 retval = cpuidle_register_driver(&intel_idle_driver);
1416 if (retval) {
1417 struct cpuidle_driver *drv = cpuidle_get_driver();
1418 printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
1419 drv ? drv->name : "none");
1420 free_percpu(intel_idle_cpuidle_devices);
1421 return retval;
1424 cpu_notifier_register_begin();
1426 for_each_online_cpu(i) {
1427 retval = intel_idle_cpu_init(i);
1428 if (retval) {
1429 intel_idle_cpuidle_devices_uninit();
1430 cpu_notifier_register_done();
1431 cpuidle_unregister_driver(&intel_idle_driver);
1432 free_percpu(intel_idle_cpuidle_devices);
1433 return retval;
1436 __register_cpu_notifier(&cpu_hotplug_notifier);
1438 if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
1439 lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
1440 else
1441 on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
1443 cpu_notifier_register_done();
1445 pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
1446 lapic_timer_reliable_states);
1448 return 0;
1450 device_initcall(intel_idle_init);
1453 * We are not really modular, but we used to support that. Meaning we also
1454 * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1455 * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1456 * is the easiest way (currently) to continue doing that.
1458 module_param(max_cstate, int, 0444);