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
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.
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
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 */
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>
67 #define INTEL_IDLE_VERSION "0.4.1"
68 #define PREFIX "intel_idle: "
70 static struct cpuidle_driver intel_idle_driver
= {
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 */
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
[] = {
131 .desc
= "MWAIT 0x00",
132 .flags
= MWAIT2flg(0x00),
134 .target_residency
= 6,
135 .enter
= &intel_idle
,
136 .enter_freeze
= intel_idle_freeze
, },
139 .desc
= "MWAIT 0x01",
140 .flags
= MWAIT2flg(0x01),
142 .target_residency
= 20,
143 .enter
= &intel_idle
,
144 .enter_freeze
= intel_idle_freeze
, },
147 .desc
= "MWAIT 0x10",
148 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
150 .target_residency
= 80,
151 .enter
= &intel_idle
,
152 .enter_freeze
= intel_idle_freeze
, },
155 .desc
= "MWAIT 0x20",
156 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
158 .target_residency
= 800,
159 .enter
= &intel_idle
,
160 .enter_freeze
= intel_idle_freeze
, },
165 static struct cpuidle_state snb_cstates
[] = {
168 .desc
= "MWAIT 0x00",
169 .flags
= MWAIT2flg(0x00),
171 .target_residency
= 2,
172 .enter
= &intel_idle
,
173 .enter_freeze
= intel_idle_freeze
, },
176 .desc
= "MWAIT 0x01",
177 .flags
= MWAIT2flg(0x01),
179 .target_residency
= 20,
180 .enter
= &intel_idle
,
181 .enter_freeze
= intel_idle_freeze
, },
184 .desc
= "MWAIT 0x10",
185 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
187 .target_residency
= 211,
188 .enter
= &intel_idle
,
189 .enter_freeze
= intel_idle_freeze
, },
192 .desc
= "MWAIT 0x20",
193 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
195 .target_residency
= 345,
196 .enter
= &intel_idle
,
197 .enter_freeze
= intel_idle_freeze
, },
200 .desc
= "MWAIT 0x30",
201 .flags
= MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED
,
203 .target_residency
= 345,
204 .enter
= &intel_idle
,
205 .enter_freeze
= intel_idle_freeze
, },
210 static struct cpuidle_state byt_cstates
[] = {
213 .desc
= "MWAIT 0x00",
214 .flags
= MWAIT2flg(0x00),
216 .target_residency
= 1,
217 .enter
= &intel_idle
,
218 .enter_freeze
= intel_idle_freeze
, },
221 .desc
= "MWAIT 0x58",
222 .flags
= MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED
,
224 .target_residency
= 275,
225 .enter
= &intel_idle
,
226 .enter_freeze
= intel_idle_freeze
, },
229 .desc
= "MWAIT 0x52",
230 .flags
= MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED
,
232 .target_residency
= 560,
233 .enter
= &intel_idle
,
234 .enter_freeze
= intel_idle_freeze
, },
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
, },
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
, },
255 static struct cpuidle_state cht_cstates
[] = {
258 .desc
= "MWAIT 0x00",
259 .flags
= MWAIT2flg(0x00),
261 .target_residency
= 1,
262 .enter
= &intel_idle
,
263 .enter_freeze
= intel_idle_freeze
, },
266 .desc
= "MWAIT 0x58",
267 .flags
= MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED
,
269 .target_residency
= 275,
270 .enter
= &intel_idle
,
271 .enter_freeze
= intel_idle_freeze
, },
274 .desc
= "MWAIT 0x52",
275 .flags
= MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED
,
277 .target_residency
= 560,
278 .enter
= &intel_idle
,
279 .enter_freeze
= intel_idle_freeze
, },
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
, },
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
, },
300 static struct cpuidle_state ivb_cstates
[] = {
303 .desc
= "MWAIT 0x00",
304 .flags
= MWAIT2flg(0x00),
306 .target_residency
= 1,
307 .enter
= &intel_idle
,
308 .enter_freeze
= intel_idle_freeze
, },
311 .desc
= "MWAIT 0x01",
312 .flags
= MWAIT2flg(0x01),
314 .target_residency
= 20,
315 .enter
= &intel_idle
,
316 .enter_freeze
= intel_idle_freeze
, },
319 .desc
= "MWAIT 0x10",
320 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
322 .target_residency
= 156,
323 .enter
= &intel_idle
,
324 .enter_freeze
= intel_idle_freeze
, },
327 .desc
= "MWAIT 0x20",
328 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
330 .target_residency
= 300,
331 .enter
= &intel_idle
,
332 .enter_freeze
= intel_idle_freeze
, },
335 .desc
= "MWAIT 0x30",
336 .flags
= MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED
,
338 .target_residency
= 300,
339 .enter
= &intel_idle
,
340 .enter_freeze
= intel_idle_freeze
, },
345 static struct cpuidle_state ivt_cstates
[] = {
348 .desc
= "MWAIT 0x00",
349 .flags
= MWAIT2flg(0x00),
351 .target_residency
= 1,
352 .enter
= &intel_idle
,
353 .enter_freeze
= intel_idle_freeze
, },
356 .desc
= "MWAIT 0x01",
357 .flags
= MWAIT2flg(0x01),
359 .target_residency
= 80,
360 .enter
= &intel_idle
,
361 .enter_freeze
= intel_idle_freeze
, },
364 .desc
= "MWAIT 0x10",
365 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
367 .target_residency
= 156,
368 .enter
= &intel_idle
,
369 .enter_freeze
= intel_idle_freeze
, },
372 .desc
= "MWAIT 0x20",
373 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
375 .target_residency
= 300,
376 .enter
= &intel_idle
,
377 .enter_freeze
= intel_idle_freeze
, },
382 static struct cpuidle_state ivt_cstates_4s
[] = {
385 .desc
= "MWAIT 0x00",
386 .flags
= MWAIT2flg(0x00),
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),
396 .target_residency
= 250,
397 .enter
= &intel_idle
,
398 .enter_freeze
= intel_idle_freeze
, },
401 .desc
= "MWAIT 0x10",
402 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
404 .target_residency
= 300,
405 .enter
= &intel_idle
,
406 .enter_freeze
= intel_idle_freeze
, },
409 .desc
= "MWAIT 0x20",
410 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
412 .target_residency
= 400,
413 .enter
= &intel_idle
,
414 .enter_freeze
= intel_idle_freeze
, },
419 static struct cpuidle_state ivt_cstates_8s
[] = {
422 .desc
= "MWAIT 0x00",
423 .flags
= MWAIT2flg(0x00),
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),
433 .target_residency
= 500,
434 .enter
= &intel_idle
,
435 .enter_freeze
= intel_idle_freeze
, },
438 .desc
= "MWAIT 0x10",
439 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
441 .target_residency
= 600,
442 .enter
= &intel_idle
,
443 .enter_freeze
= intel_idle_freeze
, },
446 .desc
= "MWAIT 0x20",
447 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
449 .target_residency
= 700,
450 .enter
= &intel_idle
,
451 .enter_freeze
= intel_idle_freeze
, },
456 static struct cpuidle_state hsw_cstates
[] = {
459 .desc
= "MWAIT 0x00",
460 .flags
= MWAIT2flg(0x00),
462 .target_residency
= 2,
463 .enter
= &intel_idle
,
464 .enter_freeze
= intel_idle_freeze
, },
467 .desc
= "MWAIT 0x01",
468 .flags
= MWAIT2flg(0x01),
470 .target_residency
= 20,
471 .enter
= &intel_idle
,
472 .enter_freeze
= intel_idle_freeze
, },
475 .desc
= "MWAIT 0x10",
476 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
478 .target_residency
= 100,
479 .enter
= &intel_idle
,
480 .enter_freeze
= intel_idle_freeze
, },
483 .desc
= "MWAIT 0x20",
484 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
486 .target_residency
= 400,
487 .enter
= &intel_idle
,
488 .enter_freeze
= intel_idle_freeze
, },
491 .desc
= "MWAIT 0x32",
492 .flags
= MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED
,
494 .target_residency
= 500,
495 .enter
= &intel_idle
,
496 .enter_freeze
= intel_idle_freeze
, },
499 .desc
= "MWAIT 0x40",
500 .flags
= MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED
,
502 .target_residency
= 900,
503 .enter
= &intel_idle
,
504 .enter_freeze
= intel_idle_freeze
, },
507 .desc
= "MWAIT 0x50",
508 .flags
= MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED
,
510 .target_residency
= 1800,
511 .enter
= &intel_idle
,
512 .enter_freeze
= intel_idle_freeze
, },
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
, },
524 static struct cpuidle_state bdw_cstates
[] = {
527 .desc
= "MWAIT 0x00",
528 .flags
= MWAIT2flg(0x00),
530 .target_residency
= 2,
531 .enter
= &intel_idle
,
532 .enter_freeze
= intel_idle_freeze
, },
535 .desc
= "MWAIT 0x01",
536 .flags
= MWAIT2flg(0x01),
538 .target_residency
= 20,
539 .enter
= &intel_idle
,
540 .enter_freeze
= intel_idle_freeze
, },
543 .desc
= "MWAIT 0x10",
544 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
546 .target_residency
= 100,
547 .enter
= &intel_idle
,
548 .enter_freeze
= intel_idle_freeze
, },
551 .desc
= "MWAIT 0x20",
552 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
554 .target_residency
= 400,
555 .enter
= &intel_idle
,
556 .enter_freeze
= intel_idle_freeze
, },
559 .desc
= "MWAIT 0x32",
560 .flags
= MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED
,
562 .target_residency
= 500,
563 .enter
= &intel_idle
,
564 .enter_freeze
= intel_idle_freeze
, },
567 .desc
= "MWAIT 0x40",
568 .flags
= MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED
,
570 .target_residency
= 900,
571 .enter
= &intel_idle
,
572 .enter_freeze
= intel_idle_freeze
, },
575 .desc
= "MWAIT 0x50",
576 .flags
= MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED
,
578 .target_residency
= 1800,
579 .enter
= &intel_idle
,
580 .enter_freeze
= intel_idle_freeze
, },
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
, },
593 static struct cpuidle_state skl_cstates
[] = {
596 .desc
= "MWAIT 0x00",
597 .flags
= MWAIT2flg(0x00),
599 .target_residency
= 2,
600 .enter
= &intel_idle
,
601 .enter_freeze
= intel_idle_freeze
, },
604 .desc
= "MWAIT 0x01",
605 .flags
= MWAIT2flg(0x01),
607 .target_residency
= 20,
608 .enter
= &intel_idle
,
609 .enter_freeze
= intel_idle_freeze
, },
612 .desc
= "MWAIT 0x10",
613 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
615 .target_residency
= 100,
616 .enter
= &intel_idle
,
617 .enter_freeze
= intel_idle_freeze
, },
620 .desc
= "MWAIT 0x20",
621 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
623 .target_residency
= 200,
624 .enter
= &intel_idle
,
625 .enter_freeze
= intel_idle_freeze
, },
628 .desc
= "MWAIT 0x33",
629 .flags
= MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED
,
631 .target_residency
= 800,
632 .enter
= &intel_idle
,
633 .enter_freeze
= intel_idle_freeze
, },
636 .desc
= "MWAIT 0x40",
637 .flags
= MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED
,
639 .target_residency
= 800,
640 .enter
= &intel_idle
,
641 .enter_freeze
= intel_idle_freeze
, },
644 .desc
= "MWAIT 0x50",
645 .flags
= MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED
,
647 .target_residency
= 5000,
648 .enter
= &intel_idle
,
649 .enter_freeze
= intel_idle_freeze
, },
652 .desc
= "MWAIT 0x60",
653 .flags
= MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED
,
655 .target_residency
= 5000,
656 .enter
= &intel_idle
,
657 .enter_freeze
= intel_idle_freeze
, },
662 static struct cpuidle_state skx_cstates
[] = {
665 .desc
= "MWAIT 0x00",
666 .flags
= MWAIT2flg(0x00),
668 .target_residency
= 2,
669 .enter
= &intel_idle
,
670 .enter_freeze
= intel_idle_freeze
, },
673 .desc
= "MWAIT 0x01",
674 .flags
= MWAIT2flg(0x01),
676 .target_residency
= 20,
677 .enter
= &intel_idle
,
678 .enter_freeze
= intel_idle_freeze
, },
681 .desc
= "MWAIT 0x20",
682 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
684 .target_residency
= 600,
685 .enter
= &intel_idle
,
686 .enter_freeze
= intel_idle_freeze
, },
691 static struct cpuidle_state atom_cstates
[] = {
694 .desc
= "MWAIT 0x00",
695 .flags
= MWAIT2flg(0x00),
697 .target_residency
= 20,
698 .enter
= &intel_idle
,
699 .enter_freeze
= intel_idle_freeze
, },
702 .desc
= "MWAIT 0x10",
703 .flags
= MWAIT2flg(0x10),
705 .target_residency
= 80,
706 .enter
= &intel_idle
,
707 .enter_freeze
= intel_idle_freeze
, },
710 .desc
= "MWAIT 0x30",
711 .flags
= MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED
,
713 .target_residency
= 400,
714 .enter
= &intel_idle
,
715 .enter_freeze
= intel_idle_freeze
, },
718 .desc
= "MWAIT 0x52",
719 .flags
= MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED
,
721 .target_residency
= 560,
722 .enter
= &intel_idle
,
723 .enter_freeze
= intel_idle_freeze
, },
727 static struct cpuidle_state avn_cstates
[] = {
730 .desc
= "MWAIT 0x00",
731 .flags
= MWAIT2flg(0x00),
733 .target_residency
= 2,
734 .enter
= &intel_idle
,
735 .enter_freeze
= intel_idle_freeze
, },
738 .desc
= "MWAIT 0x51",
739 .flags
= MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED
,
741 .target_residency
= 45,
742 .enter
= &intel_idle
,
743 .enter_freeze
= intel_idle_freeze
, },
747 static struct cpuidle_state knl_cstates
[] = {
750 .desc
= "MWAIT 0x00",
751 .flags
= MWAIT2flg(0x00),
753 .target_residency
= 2,
754 .enter
= &intel_idle
,
755 .enter_freeze
= intel_idle_freeze
},
758 .desc
= "MWAIT 0x10",
759 .flags
= MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED
,
761 .target_residency
= 500,
762 .enter
= &intel_idle
,
763 .enter_freeze
= intel_idle_freeze
},
768 static struct cpuidle_state bxt_cstates
[] = {
771 .desc
= "MWAIT 0x00",
772 .flags
= MWAIT2flg(0x00),
774 .target_residency
= 2,
775 .enter
= &intel_idle
,
776 .enter_freeze
= intel_idle_freeze
, },
779 .desc
= "MWAIT 0x01",
780 .flags
= MWAIT2flg(0x01),
782 .target_residency
= 20,
783 .enter
= &intel_idle
,
784 .enter_freeze
= intel_idle_freeze
, },
787 .desc
= "MWAIT 0x20",
788 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
790 .target_residency
= 133,
791 .enter
= &intel_idle
,
792 .enter_freeze
= intel_idle_freeze
, },
795 .desc
= "MWAIT 0x31",
796 .flags
= MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED
,
798 .target_residency
= 155,
799 .enter
= &intel_idle
,
800 .enter_freeze
= intel_idle_freeze
, },
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
, },
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
, },
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
, },
829 static struct cpuidle_state dnv_cstates
[] = {
832 .desc
= "MWAIT 0x00",
833 .flags
= MWAIT2flg(0x00),
835 .target_residency
= 2,
836 .enter
= &intel_idle
,
837 .enter_freeze
= intel_idle_freeze
, },
840 .desc
= "MWAIT 0x01",
841 .flags
= MWAIT2flg(0x01),
843 .target_residency
= 20,
844 .enter
= &intel_idle
,
845 .enter_freeze
= intel_idle_freeze
, },
848 .desc
= "MWAIT 0x20",
849 .flags
= MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED
,
851 .target_residency
= 500,
852 .enter
= &intel_idle
,
853 .enter_freeze
= intel_idle_freeze
, },
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
);
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
)
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();
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
;
915 tick_broadcast_enable();
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
) {
929 if (lapic_timer_reliable_states
!= LAPIC_TIMER_ALWAYS_RELIABLE
)
930 smp_call_function_single(hotcpu
, __setup_broadcast_timer
,
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
);
942 if (intel_idle_cpu_init(hotcpu
))
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
);
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");
1105 id
= x86_match_cpu(intel_idle_ids
);
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
);
1114 if (boot_cpu_data
.cpuid_level
< CPUID_MWAIT_LEAF
)
1117 cpuid(CPUID_MWAIT_LEAF
, &eax
, &ebx
, &ecx
, &mwait_substates
);
1119 if (!(ecx
& CPUID5_ECX_EXTENSIONS_SUPPORTED
) ||
1120 !(ecx
& CPUID5_ECX_INTERRUPT_BREAK
) ||
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
);
1136 * intel_idle_cpuidle_devices_uninit()
1137 * Unregisters the cpuidle devices.
1139 static void intel_idle_cpuidle_devices_uninit(void)
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
;
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
;
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
;
1208 rdmsrl(MSR_PKGC6_IRTL
, msr
);
1209 usec
= irtl_2_usec(msr
);
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
);
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
);
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
);
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
);
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)
1260 /* if PC10 not present in CPUID.MWAIT.EDX */
1261 if ((mwait_substates
& (0xF << 28)) == 0)
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)
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))
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();
1299 case INTEL_FAM6_ATOM_GOLDMONT
:
1300 bxt_idle_state_table_update();
1302 case INTEL_FAM6_SKYLAKE_DESKTOP
:
1303 sklh_idle_state_table_update();
1309 * intel_idle_cpuidle_driver_init()
1310 * allocate, initialize cpuidle_states
1312 static void __init
intel_idle_cpuidle_driver_init(void)
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
))
1328 if (cstate
+ 1 > max_cstate
) {
1329 printk(PREFIX
"max_cstate %d reached\n",
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)
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
);
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
);
1384 if (cpuidle_register_device(dev
)) {
1385 pr_debug(PREFIX
"cpuidle_register_device %d failed!\n", cpu
);
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);
1398 static int __init
intel_idle_init(void)
1402 /* Do not load intel_idle at all for now if idle= is passed */
1403 if (boot_option_idle_override
!= IDLE_NO_OVERRIDE
)
1406 retval
= intel_idle_probe();
1410 intel_idle_cpuidle_devices
= alloc_percpu(struct cpuidle_device
);
1411 if (intel_idle_cpuidle_devices
== NULL
)
1414 intel_idle_cpuidle_driver_init();
1415 retval
= cpuidle_register_driver(&intel_idle_driver
);
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
);
1424 cpu_notifier_register_begin();
1426 for_each_online_cpu(i
) {
1427 retval
= intel_idle_cpu_init(i
);
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
);
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
;
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
);
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);