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.
49 * There is currently no kernel-based automatic probing/loading mechanism
50 * if the driver is built as a module.
53 /* un-comment DEBUG to enable pr_debug() statements */
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>
68 #define INTEL_IDLE_VERSION "0.4.1"
69 #define PREFIX "intel_idle: "
71 static struct cpuidle_driver intel_idle_driver = {
75 /* intel_idle.max_cstate=0 disables driver */
76 static int max_cstate = CPUIDLE_STATE_MAX - 1;
78 static unsigned int mwait_substates;
80 #define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
81 /* Reliable LAPIC Timer States, bit 1 for C1 etc. */
82 static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */
85 struct cpuidle_state *state_table;
88 * Hardware C-state auto-demotion may not always be optimal.
89 * Indicate which enable bits to clear here.
91 unsigned long auto_demotion_disable_flags;
92 bool byt_auto_demotion_disable_flag;
93 bool disable_promotion_to_c1e;
96 static const struct idle_cpu *icpu;
97 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
98 static int intel_idle(struct cpuidle_device *dev,
99 struct cpuidle_driver *drv, int index);
100 static void intel_idle_freeze(struct cpuidle_device *dev,
101 struct cpuidle_driver *drv, int index);
102 static int intel_idle_cpu_init(int cpu);
104 static struct cpuidle_state *cpuidle_state_table;
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.
112 #define CPUIDLE_FLAG_TLB_FLUSHED 0x10000
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.
119 * We store the hint at the top of our "flags" for each state.
121 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
122 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
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.
129 static struct cpuidle_state nehalem_cstates[] = {
132 .desc = "MWAIT 0x00",
133 .flags = MWAIT2flg(0x00),
135 .target_residency = 6,
136 .enter = &intel_idle,
137 .enter_freeze = intel_idle_freeze, },
140 .desc = "MWAIT 0x01",
141 .flags = MWAIT2flg(0x01),
143 .target_residency = 20,
144 .enter = &intel_idle,
145 .enter_freeze = intel_idle_freeze, },
148 .desc = "MWAIT 0x10",
149 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
151 .target_residency = 80,
152 .enter = &intel_idle,
153 .enter_freeze = intel_idle_freeze, },
156 .desc = "MWAIT 0x20",
157 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
159 .target_residency = 800,
160 .enter = &intel_idle,
161 .enter_freeze = intel_idle_freeze, },
166 static struct cpuidle_state snb_cstates[] = {
169 .desc = "MWAIT 0x00",
170 .flags = MWAIT2flg(0x00),
172 .target_residency = 2,
173 .enter = &intel_idle,
174 .enter_freeze = intel_idle_freeze, },
177 .desc = "MWAIT 0x01",
178 .flags = MWAIT2flg(0x01),
180 .target_residency = 20,
181 .enter = &intel_idle,
182 .enter_freeze = intel_idle_freeze, },
185 .desc = "MWAIT 0x10",
186 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
188 .target_residency = 211,
189 .enter = &intel_idle,
190 .enter_freeze = intel_idle_freeze, },
193 .desc = "MWAIT 0x20",
194 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
196 .target_residency = 345,
197 .enter = &intel_idle,
198 .enter_freeze = intel_idle_freeze, },
201 .desc = "MWAIT 0x30",
202 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
204 .target_residency = 345,
205 .enter = &intel_idle,
206 .enter_freeze = intel_idle_freeze, },
211 static struct cpuidle_state byt_cstates[] = {
214 .desc = "MWAIT 0x00",
215 .flags = MWAIT2flg(0x00),
217 .target_residency = 1,
218 .enter = &intel_idle,
219 .enter_freeze = intel_idle_freeze, },
222 .desc = "MWAIT 0x58",
223 .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
225 .target_residency = 275,
226 .enter = &intel_idle,
227 .enter_freeze = intel_idle_freeze, },
230 .desc = "MWAIT 0x52",
231 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
233 .target_residency = 560,
234 .enter = &intel_idle,
235 .enter_freeze = intel_idle_freeze, },
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, },
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, },
256 static struct cpuidle_state cht_cstates[] = {
259 .desc = "MWAIT 0x00",
260 .flags = MWAIT2flg(0x00),
262 .target_residency = 1,
263 .enter = &intel_idle,
264 .enter_freeze = intel_idle_freeze, },
267 .desc = "MWAIT 0x58",
268 .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
270 .target_residency = 275,
271 .enter = &intel_idle,
272 .enter_freeze = intel_idle_freeze, },
275 .desc = "MWAIT 0x52",
276 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
278 .target_residency = 560,
279 .enter = &intel_idle,
280 .enter_freeze = intel_idle_freeze, },
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, },
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, },
301 static struct cpuidle_state ivb_cstates[] = {
304 .desc = "MWAIT 0x00",
305 .flags = MWAIT2flg(0x00),
307 .target_residency = 1,
308 .enter = &intel_idle,
309 .enter_freeze = intel_idle_freeze, },
312 .desc = "MWAIT 0x01",
313 .flags = MWAIT2flg(0x01),
315 .target_residency = 20,
316 .enter = &intel_idle,
317 .enter_freeze = intel_idle_freeze, },
320 .desc = "MWAIT 0x10",
321 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
323 .target_residency = 156,
324 .enter = &intel_idle,
325 .enter_freeze = intel_idle_freeze, },
328 .desc = "MWAIT 0x20",
329 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
331 .target_residency = 300,
332 .enter = &intel_idle,
333 .enter_freeze = intel_idle_freeze, },
336 .desc = "MWAIT 0x30",
337 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
339 .target_residency = 300,
340 .enter = &intel_idle,
341 .enter_freeze = intel_idle_freeze, },
346 static struct cpuidle_state ivt_cstates[] = {
349 .desc = "MWAIT 0x00",
350 .flags = MWAIT2flg(0x00),
352 .target_residency = 1,
353 .enter = &intel_idle,
354 .enter_freeze = intel_idle_freeze, },
357 .desc = "MWAIT 0x01",
358 .flags = MWAIT2flg(0x01),
360 .target_residency = 80,
361 .enter = &intel_idle,
362 .enter_freeze = intel_idle_freeze, },
365 .desc = "MWAIT 0x10",
366 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
368 .target_residency = 156,
369 .enter = &intel_idle,
370 .enter_freeze = intel_idle_freeze, },
373 .desc = "MWAIT 0x20",
374 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
376 .target_residency = 300,
377 .enter = &intel_idle,
378 .enter_freeze = intel_idle_freeze, },
383 static struct cpuidle_state ivt_cstates_4s[] = {
386 .desc = "MWAIT 0x00",
387 .flags = MWAIT2flg(0x00),
389 .target_residency = 1,
390 .enter = &intel_idle,
391 .enter_freeze = intel_idle_freeze, },
393 .name = "C1E-IVT-4S",
394 .desc = "MWAIT 0x01",
395 .flags = MWAIT2flg(0x01),
397 .target_residency = 250,
398 .enter = &intel_idle,
399 .enter_freeze = intel_idle_freeze, },
402 .desc = "MWAIT 0x10",
403 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
405 .target_residency = 300,
406 .enter = &intel_idle,
407 .enter_freeze = intel_idle_freeze, },
410 .desc = "MWAIT 0x20",
411 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
413 .target_residency = 400,
414 .enter = &intel_idle,
415 .enter_freeze = intel_idle_freeze, },
420 static struct cpuidle_state ivt_cstates_8s[] = {
423 .desc = "MWAIT 0x00",
424 .flags = MWAIT2flg(0x00),
426 .target_residency = 1,
427 .enter = &intel_idle,
428 .enter_freeze = intel_idle_freeze, },
430 .name = "C1E-IVT-8S",
431 .desc = "MWAIT 0x01",
432 .flags = MWAIT2flg(0x01),
434 .target_residency = 500,
435 .enter = &intel_idle,
436 .enter_freeze = intel_idle_freeze, },
439 .desc = "MWAIT 0x10",
440 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
442 .target_residency = 600,
443 .enter = &intel_idle,
444 .enter_freeze = intel_idle_freeze, },
447 .desc = "MWAIT 0x20",
448 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
450 .target_residency = 700,
451 .enter = &intel_idle,
452 .enter_freeze = intel_idle_freeze, },
457 static struct cpuidle_state hsw_cstates[] = {
460 .desc = "MWAIT 0x00",
461 .flags = MWAIT2flg(0x00),
463 .target_residency = 2,
464 .enter = &intel_idle,
465 .enter_freeze = intel_idle_freeze, },
468 .desc = "MWAIT 0x01",
469 .flags = MWAIT2flg(0x01),
471 .target_residency = 20,
472 .enter = &intel_idle,
473 .enter_freeze = intel_idle_freeze, },
476 .desc = "MWAIT 0x10",
477 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
479 .target_residency = 100,
480 .enter = &intel_idle,
481 .enter_freeze = intel_idle_freeze, },
484 .desc = "MWAIT 0x20",
485 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
487 .target_residency = 400,
488 .enter = &intel_idle,
489 .enter_freeze = intel_idle_freeze, },
492 .desc = "MWAIT 0x32",
493 .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
495 .target_residency = 500,
496 .enter = &intel_idle,
497 .enter_freeze = intel_idle_freeze, },
500 .desc = "MWAIT 0x40",
501 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
503 .target_residency = 900,
504 .enter = &intel_idle,
505 .enter_freeze = intel_idle_freeze, },
508 .desc = "MWAIT 0x50",
509 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
511 .target_residency = 1800,
512 .enter = &intel_idle,
513 .enter_freeze = intel_idle_freeze, },
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, },
525 static struct cpuidle_state bdw_cstates[] = {
528 .desc = "MWAIT 0x00",
529 .flags = MWAIT2flg(0x00),
531 .target_residency = 2,
532 .enter = &intel_idle,
533 .enter_freeze = intel_idle_freeze, },
536 .desc = "MWAIT 0x01",
537 .flags = MWAIT2flg(0x01),
539 .target_residency = 20,
540 .enter = &intel_idle,
541 .enter_freeze = intel_idle_freeze, },
544 .desc = "MWAIT 0x10",
545 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
547 .target_residency = 100,
548 .enter = &intel_idle,
549 .enter_freeze = intel_idle_freeze, },
552 .desc = "MWAIT 0x20",
553 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
555 .target_residency = 400,
556 .enter = &intel_idle,
557 .enter_freeze = intel_idle_freeze, },
560 .desc = "MWAIT 0x32",
561 .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
563 .target_residency = 500,
564 .enter = &intel_idle,
565 .enter_freeze = intel_idle_freeze, },
568 .desc = "MWAIT 0x40",
569 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
571 .target_residency = 900,
572 .enter = &intel_idle,
573 .enter_freeze = intel_idle_freeze, },
576 .desc = "MWAIT 0x50",
577 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
579 .target_residency = 1800,
580 .enter = &intel_idle,
581 .enter_freeze = intel_idle_freeze, },
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, },
594 static struct cpuidle_state skl_cstates[] = {
597 .desc = "MWAIT 0x00",
598 .flags = MWAIT2flg(0x00),
600 .target_residency = 2,
601 .enter = &intel_idle,
602 .enter_freeze = intel_idle_freeze, },
605 .desc = "MWAIT 0x01",
606 .flags = MWAIT2flg(0x01),
608 .target_residency = 20,
609 .enter = &intel_idle,
610 .enter_freeze = intel_idle_freeze, },
613 .desc = "MWAIT 0x10",
614 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
616 .target_residency = 100,
617 .enter = &intel_idle,
618 .enter_freeze = intel_idle_freeze, },
621 .desc = "MWAIT 0x20",
622 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
624 .target_residency = 200,
625 .enter = &intel_idle,
626 .enter_freeze = intel_idle_freeze, },
629 .desc = "MWAIT 0x33",
630 .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
632 .target_residency = 800,
633 .enter = &intel_idle,
634 .enter_freeze = intel_idle_freeze, },
637 .desc = "MWAIT 0x40",
638 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
640 .target_residency = 800,
641 .enter = &intel_idle,
642 .enter_freeze = intel_idle_freeze, },
645 .desc = "MWAIT 0x50",
646 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
648 .target_residency = 5000,
649 .enter = &intel_idle,
650 .enter_freeze = intel_idle_freeze, },
653 .desc = "MWAIT 0x60",
654 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
656 .target_residency = 5000,
657 .enter = &intel_idle,
658 .enter_freeze = intel_idle_freeze, },
663 static struct cpuidle_state skx_cstates[] = {
666 .desc = "MWAIT 0x00",
667 .flags = MWAIT2flg(0x00),
669 .target_residency = 2,
670 .enter = &intel_idle,
671 .enter_freeze = intel_idle_freeze, },
674 .desc = "MWAIT 0x01",
675 .flags = MWAIT2flg(0x01),
677 .target_residency = 20,
678 .enter = &intel_idle,
679 .enter_freeze = intel_idle_freeze, },
682 .desc = "MWAIT 0x20",
683 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
685 .target_residency = 600,
686 .enter = &intel_idle,
687 .enter_freeze = intel_idle_freeze, },
692 static struct cpuidle_state atom_cstates[] = {
695 .desc = "MWAIT 0x00",
696 .flags = MWAIT2flg(0x00),
698 .target_residency = 20,
699 .enter = &intel_idle,
700 .enter_freeze = intel_idle_freeze, },
703 .desc = "MWAIT 0x10",
704 .flags = MWAIT2flg(0x10),
706 .target_residency = 80,
707 .enter = &intel_idle,
708 .enter_freeze = intel_idle_freeze, },
711 .desc = "MWAIT 0x30",
712 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
714 .target_residency = 400,
715 .enter = &intel_idle,
716 .enter_freeze = intel_idle_freeze, },
719 .desc = "MWAIT 0x52",
720 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
722 .target_residency = 560,
723 .enter = &intel_idle,
724 .enter_freeze = intel_idle_freeze, },
728 static struct cpuidle_state avn_cstates[] = {
731 .desc = "MWAIT 0x00",
732 .flags = MWAIT2flg(0x00),
734 .target_residency = 2,
735 .enter = &intel_idle,
736 .enter_freeze = intel_idle_freeze, },
739 .desc = "MWAIT 0x51",
740 .flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
742 .target_residency = 45,
743 .enter = &intel_idle,
744 .enter_freeze = intel_idle_freeze, },
748 static struct cpuidle_state knl_cstates[] = {
751 .desc = "MWAIT 0x00",
752 .flags = MWAIT2flg(0x00),
754 .target_residency = 2,
755 .enter = &intel_idle,
756 .enter_freeze = intel_idle_freeze },
759 .desc = "MWAIT 0x10",
760 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
762 .target_residency = 500,
763 .enter = &intel_idle,
764 .enter_freeze = intel_idle_freeze },
771 * @dev: cpuidle_device
772 * @drv: cpuidle driver
773 * @index: index of cpuidle state
775 * Must be called under local_irq_disable().
777 static int intel_idle(struct cpuidle_device *dev,
778 struct cpuidle_driver *drv, int index)
780 unsigned long ecx = 1; /* break on interrupt flag */
781 struct cpuidle_state *state = &drv->states[index];
782 unsigned long eax = flg2MWAIT(state->flags);
784 int cpu = smp_processor_id();
786 cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
789 * leave_mm() to avoid costly and often unnecessary wakeups
790 * for flushing the user TLB's associated with the active mm.
792 if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
795 if (!(lapic_timer_reliable_states & (1 << (cstate))))
796 tick_broadcast_enter();
798 mwait_idle_with_hints(eax, ecx);
800 if (!(lapic_timer_reliable_states & (1 << (cstate))))
801 tick_broadcast_exit();
807 * intel_idle_freeze - simplified "enter" callback routine for suspend-to-idle
808 * @dev: cpuidle_device
809 * @drv: cpuidle driver
810 * @index: state index
812 static void intel_idle_freeze(struct cpuidle_device *dev,
813 struct cpuidle_driver *drv, int index)
815 unsigned long ecx = 1; /* break on interrupt flag */
816 unsigned long eax = flg2MWAIT(drv->states[index].flags);
818 mwait_idle_with_hints(eax, ecx);
821 static void __setup_broadcast_timer(void *arg)
823 unsigned long on = (unsigned long)arg;
826 tick_broadcast_enable();
828 tick_broadcast_disable();
831 static int cpu_hotplug_notify(struct notifier_block *n,
832 unsigned long action, void *hcpu)
834 int hotcpu = (unsigned long)hcpu;
835 struct cpuidle_device *dev;
837 switch (action & ~CPU_TASKS_FROZEN) {
840 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
841 smp_call_function_single(hotcpu, __setup_broadcast_timer,
845 * Some systems can hotplug a cpu at runtime after
846 * the kernel has booted, we have to initialize the
847 * driver in this case
849 dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
853 if (intel_idle_cpu_init(hotcpu))
861 static struct notifier_block cpu_hotplug_notifier = {
862 .notifier_call = cpu_hotplug_notify,
865 static void auto_demotion_disable(void *dummy)
867 unsigned long long msr_bits;
869 rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
870 msr_bits &= ~(icpu->auto_demotion_disable_flags);
871 wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
873 static void c1e_promotion_disable(void *dummy)
875 unsigned long long msr_bits;
877 rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
879 wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
882 static const struct idle_cpu idle_cpu_nehalem = {
883 .state_table = nehalem_cstates,
884 .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
885 .disable_promotion_to_c1e = true,
888 static const struct idle_cpu idle_cpu_atom = {
889 .state_table = atom_cstates,
892 static const struct idle_cpu idle_cpu_lincroft = {
893 .state_table = atom_cstates,
894 .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
897 static const struct idle_cpu idle_cpu_snb = {
898 .state_table = snb_cstates,
899 .disable_promotion_to_c1e = true,
902 static const struct idle_cpu idle_cpu_byt = {
903 .state_table = byt_cstates,
904 .disable_promotion_to_c1e = true,
905 .byt_auto_demotion_disable_flag = true,
908 static const struct idle_cpu idle_cpu_cht = {
909 .state_table = cht_cstates,
910 .disable_promotion_to_c1e = true,
911 .byt_auto_demotion_disable_flag = true,
914 static const struct idle_cpu idle_cpu_ivb = {
915 .state_table = ivb_cstates,
916 .disable_promotion_to_c1e = true,
919 static const struct idle_cpu idle_cpu_ivt = {
920 .state_table = ivt_cstates,
921 .disable_promotion_to_c1e = true,
924 static const struct idle_cpu idle_cpu_hsw = {
925 .state_table = hsw_cstates,
926 .disable_promotion_to_c1e = true,
929 static const struct idle_cpu idle_cpu_bdw = {
930 .state_table = bdw_cstates,
931 .disable_promotion_to_c1e = true,
934 static const struct idle_cpu idle_cpu_skl = {
935 .state_table = skl_cstates,
936 .disable_promotion_to_c1e = true,
939 static const struct idle_cpu idle_cpu_skx = {
940 .state_table = skx_cstates,
941 .disable_promotion_to_c1e = true,
944 static const struct idle_cpu idle_cpu_avn = {
945 .state_table = avn_cstates,
946 .disable_promotion_to_c1e = true,
949 static const struct idle_cpu idle_cpu_knl = {
950 .state_table = knl_cstates,
953 #define ICPU(model, cpu) \
954 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
956 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
957 ICPU(0x1a, idle_cpu_nehalem),
958 ICPU(0x1e, idle_cpu_nehalem),
959 ICPU(0x1f, idle_cpu_nehalem),
960 ICPU(0x25, idle_cpu_nehalem),
961 ICPU(0x2c, idle_cpu_nehalem),
962 ICPU(0x2e, idle_cpu_nehalem),
963 ICPU(0x1c, idle_cpu_atom),
964 ICPU(0x26, idle_cpu_lincroft),
965 ICPU(0x2f, idle_cpu_nehalem),
966 ICPU(0x2a, idle_cpu_snb),
967 ICPU(0x2d, idle_cpu_snb),
968 ICPU(0x36, idle_cpu_atom),
969 ICPU(0x37, idle_cpu_byt),
970 ICPU(0x4c, idle_cpu_cht),
971 ICPU(0x3a, idle_cpu_ivb),
972 ICPU(0x3e, idle_cpu_ivt),
973 ICPU(0x3c, idle_cpu_hsw),
974 ICPU(0x3f, idle_cpu_hsw),
975 ICPU(0x45, idle_cpu_hsw),
976 ICPU(0x46, idle_cpu_hsw),
977 ICPU(0x4d, idle_cpu_avn),
978 ICPU(0x3d, idle_cpu_bdw),
979 ICPU(0x47, idle_cpu_bdw),
980 ICPU(0x4f, idle_cpu_bdw),
981 ICPU(0x56, idle_cpu_bdw),
982 ICPU(0x4e, idle_cpu_skl),
983 ICPU(0x5e, idle_cpu_skl),
984 ICPU(0x8e, idle_cpu_skl),
985 ICPU(0x9e, idle_cpu_skl),
986 ICPU(0x55, idle_cpu_skx),
987 ICPU(0x57, idle_cpu_knl),
990 MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
995 static int __init intel_idle_probe(void)
997 unsigned int eax, ebx, ecx;
998 const struct x86_cpu_id *id;
1000 if (max_cstate == 0) {
1001 pr_debug(PREFIX "disabled\n");
1005 id = x86_match_cpu(intel_idle_ids);
1007 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
1008 boot_cpu_data.x86 == 6)
1009 pr_debug(PREFIX "does not run on family %d model %d\n",
1010 boot_cpu_data.x86, boot_cpu_data.x86_model);
1014 if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1017 cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1019 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1020 !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1024 pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
1026 icpu = (const struct idle_cpu *)id->driver_data;
1027 cpuidle_state_table = icpu->state_table;
1029 pr_debug(PREFIX "v" INTEL_IDLE_VERSION
1030 " model 0x%X\n", boot_cpu_data.x86_model);
1036 * intel_idle_cpuidle_devices_uninit()
1037 * Unregisters the cpuidle devices.
1039 static void intel_idle_cpuidle_devices_uninit(void)
1042 struct cpuidle_device *dev;
1044 for_each_online_cpu(i) {
1045 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1046 cpuidle_unregister_device(dev);
1051 * ivt_idle_state_table_update(void)
1053 * Tune IVT multi-socket targets
1054 * Assumption: num_sockets == (max_package_num + 1)
1056 static void ivt_idle_state_table_update(void)
1058 /* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1059 int cpu, package_num, num_sockets = 1;
1061 for_each_online_cpu(cpu) {
1062 package_num = topology_physical_package_id(cpu);
1063 if (package_num + 1 > num_sockets) {
1064 num_sockets = package_num + 1;
1066 if (num_sockets > 4) {
1067 cpuidle_state_table = ivt_cstates_8s;
1073 if (num_sockets > 2)
1074 cpuidle_state_table = ivt_cstates_4s;
1076 /* else, 1 and 2 socket systems use default ivt_cstates */
1079 * sklh_idle_state_table_update(void)
1081 * On SKL-H (model 0x5e) disable C8 and C9 if:
1082 * C10 is enabled and SGX disabled
1084 static void sklh_idle_state_table_update(void)
1086 unsigned long long msr;
1087 unsigned int eax, ebx, ecx, edx;
1090 /* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1091 if (max_cstate <= 7)
1094 /* if PC10 not present in CPUID.MWAIT.EDX */
1095 if ((mwait_substates & (0xF << 28)) == 0)
1098 rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr);
1100 /* PC10 is not enabled in PKG C-state limit */
1101 if ((msr & 0xF) != 8)
1105 cpuid(7, &eax, &ebx, &ecx, &edx);
1107 /* if SGX is present */
1108 if (ebx & (1 << 2)) {
1110 rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
1112 /* if SGX is enabled */
1113 if (msr & (1 << 18))
1117 skl_cstates[5].disabled = 1; /* C8-SKL */
1118 skl_cstates[6].disabled = 1; /* C9-SKL */
1121 * intel_idle_state_table_update()
1123 * Update the default state_table for this CPU-id
1126 static void intel_idle_state_table_update(void)
1128 switch (boot_cpu_data.x86_model) {
1130 case 0x3e: /* IVT */
1131 ivt_idle_state_table_update();
1133 case 0x5e: /* SKL-H */
1134 sklh_idle_state_table_update();
1140 * intel_idle_cpuidle_driver_init()
1141 * allocate, initialize cpuidle_states
1143 static void __init intel_idle_cpuidle_driver_init(void)
1146 struct cpuidle_driver *drv = &intel_idle_driver;
1148 intel_idle_state_table_update();
1150 drv->state_count = 1;
1152 for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1153 int num_substates, mwait_hint, mwait_cstate;
1155 if ((cpuidle_state_table[cstate].enter == NULL) &&
1156 (cpuidle_state_table[cstate].enter_freeze == NULL))
1159 if (cstate + 1 > max_cstate) {
1160 printk(PREFIX "max_cstate %d reached\n",
1165 mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1166 mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
1168 /* number of sub-states for this state in CPUID.MWAIT */
1169 num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
1170 & MWAIT_SUBSTATE_MASK;
1172 /* if NO sub-states for this state in CPUID, skip it */
1173 if (num_substates == 0)
1176 /* if state marked as disabled, skip it */
1177 if (cpuidle_state_table[cstate].disabled != 0) {
1178 pr_debug(PREFIX "state %s is disabled",
1179 cpuidle_state_table[cstate].name);
1184 if (((mwait_cstate + 1) > 2) &&
1185 !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1186 mark_tsc_unstable("TSC halts in idle"
1187 " states deeper than C2");
1189 drv->states[drv->state_count] = /* structure copy */
1190 cpuidle_state_table[cstate];
1192 drv->state_count += 1;
1195 if (icpu->byt_auto_demotion_disable_flag) {
1196 wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1197 wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1203 * intel_idle_cpu_init()
1204 * allocate, initialize, register cpuidle_devices
1205 * @cpu: cpu/core to initialize
1207 static int intel_idle_cpu_init(int cpu)
1209 struct cpuidle_device *dev;
1211 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1215 if (cpuidle_register_device(dev)) {
1216 pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
1220 if (icpu->auto_demotion_disable_flags)
1221 smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
1223 if (icpu->disable_promotion_to_c1e)
1224 smp_call_function_single(cpu, c1e_promotion_disable, NULL, 1);
1229 static int __init intel_idle_init(void)
1233 /* Do not load intel_idle at all for now if idle= is passed */
1234 if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1237 retval = intel_idle_probe();
1241 intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1242 if (intel_idle_cpuidle_devices == NULL)
1245 intel_idle_cpuidle_driver_init();
1246 retval = cpuidle_register_driver(&intel_idle_driver);
1248 struct cpuidle_driver *drv = cpuidle_get_driver();
1249 printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
1250 drv ? drv->name : "none");
1251 free_percpu(intel_idle_cpuidle_devices);
1255 cpu_notifier_register_begin();
1257 for_each_online_cpu(i) {
1258 retval = intel_idle_cpu_init(i);
1260 intel_idle_cpuidle_devices_uninit();
1261 cpu_notifier_register_done();
1262 cpuidle_unregister_driver(&intel_idle_driver);
1263 free_percpu(intel_idle_cpuidle_devices);
1267 __register_cpu_notifier(&cpu_hotplug_notifier);
1269 if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
1270 lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
1272 on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
1274 cpu_notifier_register_done();
1276 pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
1277 lapic_timer_reliable_states);
1282 static void __exit intel_idle_exit(void)
1284 struct cpuidle_device *dev;
1287 cpu_notifier_register_begin();
1289 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
1290 on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
1291 __unregister_cpu_notifier(&cpu_hotplug_notifier);
1293 for_each_possible_cpu(i) {
1294 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1295 cpuidle_unregister_device(dev);
1298 cpu_notifier_register_done();
1300 cpuidle_unregister_driver(&intel_idle_driver);
1301 free_percpu(intel_idle_cpuidle_devices);
1304 module_init(intel_idle_init);
1305 module_exit(intel_idle_exit);
1307 module_param(max_cstate, int, 0444);
1309 MODULE_AUTHOR("Len Brown <len.brown@intel.com>");
1310 MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION);
1311 MODULE_LICENSE("GPL");