xref: /linux/drivers/idle/intel_idle.c (revision f7af616c632ee2ac3af0876fe33bf9e0232e665a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * intel_idle.c - native hardware idle loop for modern Intel processors
4  *
5  * Copyright (c) 2013 - 2020, Intel Corporation.
6  * Len Brown <len.brown@intel.com>
7  * Rafael J. Wysocki <rafael.j.wysocki@intel.com>
8  */
9 
10 /*
11  * intel_idle is a cpuidle driver that loads on all Intel CPUs with MWAIT
12  * in lieu of the legacy ACPI processor_idle driver.  The intent is to
13  * make Linux more efficient on these processors, as intel_idle knows
14  * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
15  */
16 
17 /*
18  * Design Assumptions
19  *
20  * All CPUs have same idle states as boot CPU
21  *
22  * Chipset BM_STS (bus master status) bit is a NOP
23  *	for preventing entry into deep C-states
24  *
25  * CPU will flush caches as needed when entering a C-state via MWAIT
26  *	(in contrast to entering ACPI C3, in which case the WBINVD
27  *	instruction needs to be executed to flush the caches)
28  */
29 
30 /*
31  * Known limitations
32  *
33  * ACPI has a .suspend hack to turn off deep c-statees during suspend
34  * to avoid complications with the lapic timer workaround.
35  * Have not seen issues with suspend, but may need same workaround here.
36  *
37  */
38 
39 /* un-comment DEBUG to enable pr_debug() statements */
40 /* #define DEBUG */
41 
42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
43 
44 #include <linux/acpi.h>
45 #include <linux/kernel.h>
46 #include <linux/cpuidle.h>
47 #include <linux/tick.h>
48 #include <trace/events/power.h>
49 #include <linux/sched.h>
50 #include <linux/notifier.h>
51 #include <linux/cpu.h>
52 #include <linux/moduleparam.h>
53 #include <asm/cpu_device_id.h>
54 #include <asm/intel-family.h>
55 #include <asm/mwait.h>
56 #include <asm/msr.h>
57 
58 #define INTEL_IDLE_VERSION "0.5.1"
59 
60 static struct cpuidle_driver intel_idle_driver = {
61 	.name = "intel_idle",
62 	.owner = THIS_MODULE,
63 };
64 /* intel_idle.max_cstate=0 disables driver */
65 static int max_cstate = CPUIDLE_STATE_MAX - 1;
66 static unsigned int disabled_states_mask;
67 
68 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
69 
70 static unsigned long auto_demotion_disable_flags;
71 static bool disable_promotion_to_c1e;
72 
73 struct idle_cpu {
74 	struct cpuidle_state *state_table;
75 
76 	/*
77 	 * Hardware C-state auto-demotion may not always be optimal.
78 	 * Indicate which enable bits to clear here.
79 	 */
80 	unsigned long auto_demotion_disable_flags;
81 	bool byt_auto_demotion_disable_flag;
82 	bool disable_promotion_to_c1e;
83 	bool use_acpi;
84 };
85 
86 static const struct idle_cpu *icpu __initdata;
87 static struct cpuidle_state *cpuidle_state_table __initdata;
88 
89 static unsigned int mwait_substates __initdata;
90 
91 /*
92  * Enable this state by default even if the ACPI _CST does not list it.
93  */
94 #define CPUIDLE_FLAG_ALWAYS_ENABLE	BIT(15)
95 
96 /*
97  * MWAIT takes an 8-bit "hint" in EAX "suggesting"
98  * the C-state (top nibble) and sub-state (bottom nibble)
99  * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
100  *
101  * We store the hint at the top of our "flags" for each state.
102  */
103 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
104 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
105 
106 /**
107  * intel_idle - Ask the processor to enter the given idle state.
108  * @dev: cpuidle device of the target CPU.
109  * @drv: cpuidle driver (assumed to point to intel_idle_driver).
110  * @index: Target idle state index.
111  *
112  * Use the MWAIT instruction to notify the processor that the CPU represented by
113  * @dev is idle and it can try to enter the idle state corresponding to @index.
114  *
115  * If the local APIC timer is not known to be reliable in the target idle state,
116  * enable one-shot tick broadcasting for the target CPU before executing MWAIT.
117  *
118  * Optionally call leave_mm() for the target CPU upfront to avoid wakeups due to
119  * flushing user TLBs.
120  *
121  * Must be called under local_irq_disable().
122  */
123 static __cpuidle int intel_idle(struct cpuidle_device *dev,
124 				struct cpuidle_driver *drv, int index)
125 {
126 	struct cpuidle_state *state = &drv->states[index];
127 	unsigned long eax = flg2MWAIT(state->flags);
128 	unsigned long ecx = 1; /* break on interrupt flag */
129 
130 	mwait_idle_with_hints(eax, ecx);
131 
132 	return index;
133 }
134 
135 /**
136  * intel_idle_s2idle - Ask the processor to enter the given idle state.
137  * @dev: cpuidle device of the target CPU.
138  * @drv: cpuidle driver (assumed to point to intel_idle_driver).
139  * @index: Target idle state index.
140  *
141  * Use the MWAIT instruction to notify the processor that the CPU represented by
142  * @dev is idle and it can try to enter the idle state corresponding to @index.
143  *
144  * Invoked as a suspend-to-idle callback routine with frozen user space, frozen
145  * scheduler tick and suspended scheduler clock on the target CPU.
146  */
147 static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev,
148 				       struct cpuidle_driver *drv, int index)
149 {
150 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
151 	unsigned long ecx = 1; /* break on interrupt flag */
152 
153 	mwait_idle_with_hints(eax, ecx);
154 
155 	return 0;
156 }
157 
158 /*
159  * States are indexed by the cstate number,
160  * which is also the index into the MWAIT hint array.
161  * Thus C0 is a dummy.
162  */
163 static struct cpuidle_state nehalem_cstates[] __initdata = {
164 	{
165 		.name = "C1",
166 		.desc = "MWAIT 0x00",
167 		.flags = MWAIT2flg(0x00),
168 		.exit_latency = 3,
169 		.target_residency = 6,
170 		.enter = &intel_idle,
171 		.enter_s2idle = intel_idle_s2idle, },
172 	{
173 		.name = "C1E",
174 		.desc = "MWAIT 0x01",
175 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
176 		.exit_latency = 10,
177 		.target_residency = 20,
178 		.enter = &intel_idle,
179 		.enter_s2idle = intel_idle_s2idle, },
180 	{
181 		.name = "C3",
182 		.desc = "MWAIT 0x10",
183 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
184 		.exit_latency = 20,
185 		.target_residency = 80,
186 		.enter = &intel_idle,
187 		.enter_s2idle = intel_idle_s2idle, },
188 	{
189 		.name = "C6",
190 		.desc = "MWAIT 0x20",
191 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
192 		.exit_latency = 200,
193 		.target_residency = 800,
194 		.enter = &intel_idle,
195 		.enter_s2idle = intel_idle_s2idle, },
196 	{
197 		.enter = NULL }
198 };
199 
200 static struct cpuidle_state snb_cstates[] __initdata = {
201 	{
202 		.name = "C1",
203 		.desc = "MWAIT 0x00",
204 		.flags = MWAIT2flg(0x00),
205 		.exit_latency = 2,
206 		.target_residency = 2,
207 		.enter = &intel_idle,
208 		.enter_s2idle = intel_idle_s2idle, },
209 	{
210 		.name = "C1E",
211 		.desc = "MWAIT 0x01",
212 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
213 		.exit_latency = 10,
214 		.target_residency = 20,
215 		.enter = &intel_idle,
216 		.enter_s2idle = intel_idle_s2idle, },
217 	{
218 		.name = "C3",
219 		.desc = "MWAIT 0x10",
220 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
221 		.exit_latency = 80,
222 		.target_residency = 211,
223 		.enter = &intel_idle,
224 		.enter_s2idle = intel_idle_s2idle, },
225 	{
226 		.name = "C6",
227 		.desc = "MWAIT 0x20",
228 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
229 		.exit_latency = 104,
230 		.target_residency = 345,
231 		.enter = &intel_idle,
232 		.enter_s2idle = intel_idle_s2idle, },
233 	{
234 		.name = "C7",
235 		.desc = "MWAIT 0x30",
236 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
237 		.exit_latency = 109,
238 		.target_residency = 345,
239 		.enter = &intel_idle,
240 		.enter_s2idle = intel_idle_s2idle, },
241 	{
242 		.enter = NULL }
243 };
244 
245 static struct cpuidle_state byt_cstates[] __initdata = {
246 	{
247 		.name = "C1",
248 		.desc = "MWAIT 0x00",
249 		.flags = MWAIT2flg(0x00),
250 		.exit_latency = 1,
251 		.target_residency = 1,
252 		.enter = &intel_idle,
253 		.enter_s2idle = intel_idle_s2idle, },
254 	{
255 		.name = "C6N",
256 		.desc = "MWAIT 0x58",
257 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
258 		.exit_latency = 300,
259 		.target_residency = 275,
260 		.enter = &intel_idle,
261 		.enter_s2idle = intel_idle_s2idle, },
262 	{
263 		.name = "C6S",
264 		.desc = "MWAIT 0x52",
265 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
266 		.exit_latency = 500,
267 		.target_residency = 560,
268 		.enter = &intel_idle,
269 		.enter_s2idle = intel_idle_s2idle, },
270 	{
271 		.name = "C7",
272 		.desc = "MWAIT 0x60",
273 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
274 		.exit_latency = 1200,
275 		.target_residency = 4000,
276 		.enter = &intel_idle,
277 		.enter_s2idle = intel_idle_s2idle, },
278 	{
279 		.name = "C7S",
280 		.desc = "MWAIT 0x64",
281 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
282 		.exit_latency = 10000,
283 		.target_residency = 20000,
284 		.enter = &intel_idle,
285 		.enter_s2idle = intel_idle_s2idle, },
286 	{
287 		.enter = NULL }
288 };
289 
290 static struct cpuidle_state cht_cstates[] __initdata = {
291 	{
292 		.name = "C1",
293 		.desc = "MWAIT 0x00",
294 		.flags = MWAIT2flg(0x00),
295 		.exit_latency = 1,
296 		.target_residency = 1,
297 		.enter = &intel_idle,
298 		.enter_s2idle = intel_idle_s2idle, },
299 	{
300 		.name = "C6N",
301 		.desc = "MWAIT 0x58",
302 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
303 		.exit_latency = 80,
304 		.target_residency = 275,
305 		.enter = &intel_idle,
306 		.enter_s2idle = intel_idle_s2idle, },
307 	{
308 		.name = "C6S",
309 		.desc = "MWAIT 0x52",
310 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
311 		.exit_latency = 200,
312 		.target_residency = 560,
313 		.enter = &intel_idle,
314 		.enter_s2idle = intel_idle_s2idle, },
315 	{
316 		.name = "C7",
317 		.desc = "MWAIT 0x60",
318 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
319 		.exit_latency = 1200,
320 		.target_residency = 4000,
321 		.enter = &intel_idle,
322 		.enter_s2idle = intel_idle_s2idle, },
323 	{
324 		.name = "C7S",
325 		.desc = "MWAIT 0x64",
326 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
327 		.exit_latency = 10000,
328 		.target_residency = 20000,
329 		.enter = &intel_idle,
330 		.enter_s2idle = intel_idle_s2idle, },
331 	{
332 		.enter = NULL }
333 };
334 
335 static struct cpuidle_state ivb_cstates[] __initdata = {
336 	{
337 		.name = "C1",
338 		.desc = "MWAIT 0x00",
339 		.flags = MWAIT2flg(0x00),
340 		.exit_latency = 1,
341 		.target_residency = 1,
342 		.enter = &intel_idle,
343 		.enter_s2idle = intel_idle_s2idle, },
344 	{
345 		.name = "C1E",
346 		.desc = "MWAIT 0x01",
347 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
348 		.exit_latency = 10,
349 		.target_residency = 20,
350 		.enter = &intel_idle,
351 		.enter_s2idle = intel_idle_s2idle, },
352 	{
353 		.name = "C3",
354 		.desc = "MWAIT 0x10",
355 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
356 		.exit_latency = 59,
357 		.target_residency = 156,
358 		.enter = &intel_idle,
359 		.enter_s2idle = intel_idle_s2idle, },
360 	{
361 		.name = "C6",
362 		.desc = "MWAIT 0x20",
363 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
364 		.exit_latency = 80,
365 		.target_residency = 300,
366 		.enter = &intel_idle,
367 		.enter_s2idle = intel_idle_s2idle, },
368 	{
369 		.name = "C7",
370 		.desc = "MWAIT 0x30",
371 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
372 		.exit_latency = 87,
373 		.target_residency = 300,
374 		.enter = &intel_idle,
375 		.enter_s2idle = intel_idle_s2idle, },
376 	{
377 		.enter = NULL }
378 };
379 
380 static struct cpuidle_state ivt_cstates[] __initdata = {
381 	{
382 		.name = "C1",
383 		.desc = "MWAIT 0x00",
384 		.flags = MWAIT2flg(0x00),
385 		.exit_latency = 1,
386 		.target_residency = 1,
387 		.enter = &intel_idle,
388 		.enter_s2idle = intel_idle_s2idle, },
389 	{
390 		.name = "C1E",
391 		.desc = "MWAIT 0x01",
392 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
393 		.exit_latency = 10,
394 		.target_residency = 80,
395 		.enter = &intel_idle,
396 		.enter_s2idle = intel_idle_s2idle, },
397 	{
398 		.name = "C3",
399 		.desc = "MWAIT 0x10",
400 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
401 		.exit_latency = 59,
402 		.target_residency = 156,
403 		.enter = &intel_idle,
404 		.enter_s2idle = intel_idle_s2idle, },
405 	{
406 		.name = "C6",
407 		.desc = "MWAIT 0x20",
408 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
409 		.exit_latency = 82,
410 		.target_residency = 300,
411 		.enter = &intel_idle,
412 		.enter_s2idle = intel_idle_s2idle, },
413 	{
414 		.enter = NULL }
415 };
416 
417 static struct cpuidle_state ivt_cstates_4s[] __initdata = {
418 	{
419 		.name = "C1",
420 		.desc = "MWAIT 0x00",
421 		.flags = MWAIT2flg(0x00),
422 		.exit_latency = 1,
423 		.target_residency = 1,
424 		.enter = &intel_idle,
425 		.enter_s2idle = intel_idle_s2idle, },
426 	{
427 		.name = "C1E",
428 		.desc = "MWAIT 0x01",
429 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
430 		.exit_latency = 10,
431 		.target_residency = 250,
432 		.enter = &intel_idle,
433 		.enter_s2idle = intel_idle_s2idle, },
434 	{
435 		.name = "C3",
436 		.desc = "MWAIT 0x10",
437 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
438 		.exit_latency = 59,
439 		.target_residency = 300,
440 		.enter = &intel_idle,
441 		.enter_s2idle = intel_idle_s2idle, },
442 	{
443 		.name = "C6",
444 		.desc = "MWAIT 0x20",
445 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
446 		.exit_latency = 84,
447 		.target_residency = 400,
448 		.enter = &intel_idle,
449 		.enter_s2idle = intel_idle_s2idle, },
450 	{
451 		.enter = NULL }
452 };
453 
454 static struct cpuidle_state ivt_cstates_8s[] __initdata = {
455 	{
456 		.name = "C1",
457 		.desc = "MWAIT 0x00",
458 		.flags = MWAIT2flg(0x00),
459 		.exit_latency = 1,
460 		.target_residency = 1,
461 		.enter = &intel_idle,
462 		.enter_s2idle = intel_idle_s2idle, },
463 	{
464 		.name = "C1E",
465 		.desc = "MWAIT 0x01",
466 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
467 		.exit_latency = 10,
468 		.target_residency = 500,
469 		.enter = &intel_idle,
470 		.enter_s2idle = intel_idle_s2idle, },
471 	{
472 		.name = "C3",
473 		.desc = "MWAIT 0x10",
474 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
475 		.exit_latency = 59,
476 		.target_residency = 600,
477 		.enter = &intel_idle,
478 		.enter_s2idle = intel_idle_s2idle, },
479 	{
480 		.name = "C6",
481 		.desc = "MWAIT 0x20",
482 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
483 		.exit_latency = 88,
484 		.target_residency = 700,
485 		.enter = &intel_idle,
486 		.enter_s2idle = intel_idle_s2idle, },
487 	{
488 		.enter = NULL }
489 };
490 
491 static struct cpuidle_state hsw_cstates[] __initdata = {
492 	{
493 		.name = "C1",
494 		.desc = "MWAIT 0x00",
495 		.flags = MWAIT2flg(0x00),
496 		.exit_latency = 2,
497 		.target_residency = 2,
498 		.enter = &intel_idle,
499 		.enter_s2idle = intel_idle_s2idle, },
500 	{
501 		.name = "C1E",
502 		.desc = "MWAIT 0x01",
503 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
504 		.exit_latency = 10,
505 		.target_residency = 20,
506 		.enter = &intel_idle,
507 		.enter_s2idle = intel_idle_s2idle, },
508 	{
509 		.name = "C3",
510 		.desc = "MWAIT 0x10",
511 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
512 		.exit_latency = 33,
513 		.target_residency = 100,
514 		.enter = &intel_idle,
515 		.enter_s2idle = intel_idle_s2idle, },
516 	{
517 		.name = "C6",
518 		.desc = "MWAIT 0x20",
519 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
520 		.exit_latency = 133,
521 		.target_residency = 400,
522 		.enter = &intel_idle,
523 		.enter_s2idle = intel_idle_s2idle, },
524 	{
525 		.name = "C7s",
526 		.desc = "MWAIT 0x32",
527 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
528 		.exit_latency = 166,
529 		.target_residency = 500,
530 		.enter = &intel_idle,
531 		.enter_s2idle = intel_idle_s2idle, },
532 	{
533 		.name = "C8",
534 		.desc = "MWAIT 0x40",
535 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
536 		.exit_latency = 300,
537 		.target_residency = 900,
538 		.enter = &intel_idle,
539 		.enter_s2idle = intel_idle_s2idle, },
540 	{
541 		.name = "C9",
542 		.desc = "MWAIT 0x50",
543 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
544 		.exit_latency = 600,
545 		.target_residency = 1800,
546 		.enter = &intel_idle,
547 		.enter_s2idle = intel_idle_s2idle, },
548 	{
549 		.name = "C10",
550 		.desc = "MWAIT 0x60",
551 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
552 		.exit_latency = 2600,
553 		.target_residency = 7700,
554 		.enter = &intel_idle,
555 		.enter_s2idle = intel_idle_s2idle, },
556 	{
557 		.enter = NULL }
558 };
559 static struct cpuidle_state bdw_cstates[] __initdata = {
560 	{
561 		.name = "C1",
562 		.desc = "MWAIT 0x00",
563 		.flags = MWAIT2flg(0x00),
564 		.exit_latency = 2,
565 		.target_residency = 2,
566 		.enter = &intel_idle,
567 		.enter_s2idle = intel_idle_s2idle, },
568 	{
569 		.name = "C1E",
570 		.desc = "MWAIT 0x01",
571 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
572 		.exit_latency = 10,
573 		.target_residency = 20,
574 		.enter = &intel_idle,
575 		.enter_s2idle = intel_idle_s2idle, },
576 	{
577 		.name = "C3",
578 		.desc = "MWAIT 0x10",
579 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
580 		.exit_latency = 40,
581 		.target_residency = 100,
582 		.enter = &intel_idle,
583 		.enter_s2idle = intel_idle_s2idle, },
584 	{
585 		.name = "C6",
586 		.desc = "MWAIT 0x20",
587 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
588 		.exit_latency = 133,
589 		.target_residency = 400,
590 		.enter = &intel_idle,
591 		.enter_s2idle = intel_idle_s2idle, },
592 	{
593 		.name = "C7s",
594 		.desc = "MWAIT 0x32",
595 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
596 		.exit_latency = 166,
597 		.target_residency = 500,
598 		.enter = &intel_idle,
599 		.enter_s2idle = intel_idle_s2idle, },
600 	{
601 		.name = "C8",
602 		.desc = "MWAIT 0x40",
603 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
604 		.exit_latency = 300,
605 		.target_residency = 900,
606 		.enter = &intel_idle,
607 		.enter_s2idle = intel_idle_s2idle, },
608 	{
609 		.name = "C9",
610 		.desc = "MWAIT 0x50",
611 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
612 		.exit_latency = 600,
613 		.target_residency = 1800,
614 		.enter = &intel_idle,
615 		.enter_s2idle = intel_idle_s2idle, },
616 	{
617 		.name = "C10",
618 		.desc = "MWAIT 0x60",
619 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
620 		.exit_latency = 2600,
621 		.target_residency = 7700,
622 		.enter = &intel_idle,
623 		.enter_s2idle = intel_idle_s2idle, },
624 	{
625 		.enter = NULL }
626 };
627 
628 static struct cpuidle_state skl_cstates[] __initdata = {
629 	{
630 		.name = "C1",
631 		.desc = "MWAIT 0x00",
632 		.flags = MWAIT2flg(0x00),
633 		.exit_latency = 2,
634 		.target_residency = 2,
635 		.enter = &intel_idle,
636 		.enter_s2idle = intel_idle_s2idle, },
637 	{
638 		.name = "C1E",
639 		.desc = "MWAIT 0x01",
640 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
641 		.exit_latency = 10,
642 		.target_residency = 20,
643 		.enter = &intel_idle,
644 		.enter_s2idle = intel_idle_s2idle, },
645 	{
646 		.name = "C3",
647 		.desc = "MWAIT 0x10",
648 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
649 		.exit_latency = 70,
650 		.target_residency = 100,
651 		.enter = &intel_idle,
652 		.enter_s2idle = intel_idle_s2idle, },
653 	{
654 		.name = "C6",
655 		.desc = "MWAIT 0x20",
656 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
657 		.exit_latency = 85,
658 		.target_residency = 200,
659 		.enter = &intel_idle,
660 		.enter_s2idle = intel_idle_s2idle, },
661 	{
662 		.name = "C7s",
663 		.desc = "MWAIT 0x33",
664 		.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
665 		.exit_latency = 124,
666 		.target_residency = 800,
667 		.enter = &intel_idle,
668 		.enter_s2idle = intel_idle_s2idle, },
669 	{
670 		.name = "C8",
671 		.desc = "MWAIT 0x40",
672 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
673 		.exit_latency = 200,
674 		.target_residency = 800,
675 		.enter = &intel_idle,
676 		.enter_s2idle = intel_idle_s2idle, },
677 	{
678 		.name = "C9",
679 		.desc = "MWAIT 0x50",
680 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
681 		.exit_latency = 480,
682 		.target_residency = 5000,
683 		.enter = &intel_idle,
684 		.enter_s2idle = intel_idle_s2idle, },
685 	{
686 		.name = "C10",
687 		.desc = "MWAIT 0x60",
688 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
689 		.exit_latency = 890,
690 		.target_residency = 5000,
691 		.enter = &intel_idle,
692 		.enter_s2idle = intel_idle_s2idle, },
693 	{
694 		.enter = NULL }
695 };
696 
697 static struct cpuidle_state skx_cstates[] __initdata = {
698 	{
699 		.name = "C1",
700 		.desc = "MWAIT 0x00",
701 		.flags = MWAIT2flg(0x00),
702 		.exit_latency = 2,
703 		.target_residency = 2,
704 		.enter = &intel_idle,
705 		.enter_s2idle = intel_idle_s2idle, },
706 	{
707 		.name = "C1E",
708 		.desc = "MWAIT 0x01",
709 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
710 		.exit_latency = 10,
711 		.target_residency = 20,
712 		.enter = &intel_idle,
713 		.enter_s2idle = intel_idle_s2idle, },
714 	{
715 		.name = "C6",
716 		.desc = "MWAIT 0x20",
717 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
718 		.exit_latency = 133,
719 		.target_residency = 600,
720 		.enter = &intel_idle,
721 		.enter_s2idle = intel_idle_s2idle, },
722 	{
723 		.enter = NULL }
724 };
725 
726 static struct cpuidle_state icx_cstates[] __initdata = {
727 	{
728 		.name = "C1",
729 		.desc = "MWAIT 0x00",
730 		.flags = MWAIT2flg(0x00),
731 		.exit_latency = 1,
732 		.target_residency = 1,
733 		.enter = &intel_idle,
734 		.enter_s2idle = intel_idle_s2idle, },
735 	{
736 		.name = "C1E",
737 		.desc = "MWAIT 0x01",
738 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
739 		.exit_latency = 4,
740 		.target_residency = 4,
741 		.enter = &intel_idle,
742 		.enter_s2idle = intel_idle_s2idle, },
743 	{
744 		.name = "C6",
745 		.desc = "MWAIT 0x20",
746 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
747 		.exit_latency = 170,
748 		.target_residency = 600,
749 		.enter = &intel_idle,
750 		.enter_s2idle = intel_idle_s2idle, },
751 	{
752 		.enter = NULL }
753 };
754 
755 static struct cpuidle_state atom_cstates[] __initdata = {
756 	{
757 		.name = "C1E",
758 		.desc = "MWAIT 0x00",
759 		.flags = MWAIT2flg(0x00),
760 		.exit_latency = 10,
761 		.target_residency = 20,
762 		.enter = &intel_idle,
763 		.enter_s2idle = intel_idle_s2idle, },
764 	{
765 		.name = "C2",
766 		.desc = "MWAIT 0x10",
767 		.flags = MWAIT2flg(0x10),
768 		.exit_latency = 20,
769 		.target_residency = 80,
770 		.enter = &intel_idle,
771 		.enter_s2idle = intel_idle_s2idle, },
772 	{
773 		.name = "C4",
774 		.desc = "MWAIT 0x30",
775 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
776 		.exit_latency = 100,
777 		.target_residency = 400,
778 		.enter = &intel_idle,
779 		.enter_s2idle = intel_idle_s2idle, },
780 	{
781 		.name = "C6",
782 		.desc = "MWAIT 0x52",
783 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
784 		.exit_latency = 140,
785 		.target_residency = 560,
786 		.enter = &intel_idle,
787 		.enter_s2idle = intel_idle_s2idle, },
788 	{
789 		.enter = NULL }
790 };
791 static struct cpuidle_state tangier_cstates[] __initdata = {
792 	{
793 		.name = "C1",
794 		.desc = "MWAIT 0x00",
795 		.flags = MWAIT2flg(0x00),
796 		.exit_latency = 1,
797 		.target_residency = 4,
798 		.enter = &intel_idle,
799 		.enter_s2idle = intel_idle_s2idle, },
800 	{
801 		.name = "C4",
802 		.desc = "MWAIT 0x30",
803 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
804 		.exit_latency = 100,
805 		.target_residency = 400,
806 		.enter = &intel_idle,
807 		.enter_s2idle = intel_idle_s2idle, },
808 	{
809 		.name = "C6",
810 		.desc = "MWAIT 0x52",
811 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
812 		.exit_latency = 140,
813 		.target_residency = 560,
814 		.enter = &intel_idle,
815 		.enter_s2idle = intel_idle_s2idle, },
816 	{
817 		.name = "C7",
818 		.desc = "MWAIT 0x60",
819 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
820 		.exit_latency = 1200,
821 		.target_residency = 4000,
822 		.enter = &intel_idle,
823 		.enter_s2idle = intel_idle_s2idle, },
824 	{
825 		.name = "C9",
826 		.desc = "MWAIT 0x64",
827 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
828 		.exit_latency = 10000,
829 		.target_residency = 20000,
830 		.enter = &intel_idle,
831 		.enter_s2idle = intel_idle_s2idle, },
832 	{
833 		.enter = NULL }
834 };
835 static struct cpuidle_state avn_cstates[] __initdata = {
836 	{
837 		.name = "C1",
838 		.desc = "MWAIT 0x00",
839 		.flags = MWAIT2flg(0x00),
840 		.exit_latency = 2,
841 		.target_residency = 2,
842 		.enter = &intel_idle,
843 		.enter_s2idle = intel_idle_s2idle, },
844 	{
845 		.name = "C6",
846 		.desc = "MWAIT 0x51",
847 		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
848 		.exit_latency = 15,
849 		.target_residency = 45,
850 		.enter = &intel_idle,
851 		.enter_s2idle = intel_idle_s2idle, },
852 	{
853 		.enter = NULL }
854 };
855 static struct cpuidle_state knl_cstates[] __initdata = {
856 	{
857 		.name = "C1",
858 		.desc = "MWAIT 0x00",
859 		.flags = MWAIT2flg(0x00),
860 		.exit_latency = 1,
861 		.target_residency = 2,
862 		.enter = &intel_idle,
863 		.enter_s2idle = intel_idle_s2idle },
864 	{
865 		.name = "C6",
866 		.desc = "MWAIT 0x10",
867 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
868 		.exit_latency = 120,
869 		.target_residency = 500,
870 		.enter = &intel_idle,
871 		.enter_s2idle = intel_idle_s2idle },
872 	{
873 		.enter = NULL }
874 };
875 
876 static struct cpuidle_state bxt_cstates[] __initdata = {
877 	{
878 		.name = "C1",
879 		.desc = "MWAIT 0x00",
880 		.flags = MWAIT2flg(0x00),
881 		.exit_latency = 2,
882 		.target_residency = 2,
883 		.enter = &intel_idle,
884 		.enter_s2idle = intel_idle_s2idle, },
885 	{
886 		.name = "C1E",
887 		.desc = "MWAIT 0x01",
888 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
889 		.exit_latency = 10,
890 		.target_residency = 20,
891 		.enter = &intel_idle,
892 		.enter_s2idle = intel_idle_s2idle, },
893 	{
894 		.name = "C6",
895 		.desc = "MWAIT 0x20",
896 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
897 		.exit_latency = 133,
898 		.target_residency = 133,
899 		.enter = &intel_idle,
900 		.enter_s2idle = intel_idle_s2idle, },
901 	{
902 		.name = "C7s",
903 		.desc = "MWAIT 0x31",
904 		.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
905 		.exit_latency = 155,
906 		.target_residency = 155,
907 		.enter = &intel_idle,
908 		.enter_s2idle = intel_idle_s2idle, },
909 	{
910 		.name = "C8",
911 		.desc = "MWAIT 0x40",
912 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
913 		.exit_latency = 1000,
914 		.target_residency = 1000,
915 		.enter = &intel_idle,
916 		.enter_s2idle = intel_idle_s2idle, },
917 	{
918 		.name = "C9",
919 		.desc = "MWAIT 0x50",
920 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
921 		.exit_latency = 2000,
922 		.target_residency = 2000,
923 		.enter = &intel_idle,
924 		.enter_s2idle = intel_idle_s2idle, },
925 	{
926 		.name = "C10",
927 		.desc = "MWAIT 0x60",
928 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
929 		.exit_latency = 10000,
930 		.target_residency = 10000,
931 		.enter = &intel_idle,
932 		.enter_s2idle = intel_idle_s2idle, },
933 	{
934 		.enter = NULL }
935 };
936 
937 static struct cpuidle_state dnv_cstates[] __initdata = {
938 	{
939 		.name = "C1",
940 		.desc = "MWAIT 0x00",
941 		.flags = MWAIT2flg(0x00),
942 		.exit_latency = 2,
943 		.target_residency = 2,
944 		.enter = &intel_idle,
945 		.enter_s2idle = intel_idle_s2idle, },
946 	{
947 		.name = "C1E",
948 		.desc = "MWAIT 0x01",
949 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
950 		.exit_latency = 10,
951 		.target_residency = 20,
952 		.enter = &intel_idle,
953 		.enter_s2idle = intel_idle_s2idle, },
954 	{
955 		.name = "C6",
956 		.desc = "MWAIT 0x20",
957 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
958 		.exit_latency = 50,
959 		.target_residency = 500,
960 		.enter = &intel_idle,
961 		.enter_s2idle = intel_idle_s2idle, },
962 	{
963 		.enter = NULL }
964 };
965 
966 /*
967  * Note, depending on HW and FW revision, SnowRidge SoC may or may not support
968  * C6, and this is indicated in the CPUID mwait leaf.
969  */
970 static struct cpuidle_state snr_cstates[] __initdata = {
971 	{
972 		.name = "C1",
973 		.desc = "MWAIT 0x00",
974 		.flags = MWAIT2flg(0x00),
975 		.exit_latency = 2,
976 		.target_residency = 2,
977 		.enter = &intel_idle,
978 		.enter_s2idle = intel_idle_s2idle, },
979 	{
980 		.name = "C1E",
981 		.desc = "MWAIT 0x01",
982 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
983 		.exit_latency = 15,
984 		.target_residency = 25,
985 		.enter = &intel_idle,
986 		.enter_s2idle = intel_idle_s2idle, },
987 	{
988 		.name = "C6",
989 		.desc = "MWAIT 0x20",
990 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
991 		.exit_latency = 130,
992 		.target_residency = 500,
993 		.enter = &intel_idle,
994 		.enter_s2idle = intel_idle_s2idle, },
995 	{
996 		.enter = NULL }
997 };
998 
999 static const struct idle_cpu idle_cpu_nehalem __initconst = {
1000 	.state_table = nehalem_cstates,
1001 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
1002 	.disable_promotion_to_c1e = true,
1003 };
1004 
1005 static const struct idle_cpu idle_cpu_nhx __initconst = {
1006 	.state_table = nehalem_cstates,
1007 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
1008 	.disable_promotion_to_c1e = true,
1009 	.use_acpi = true,
1010 };
1011 
1012 static const struct idle_cpu idle_cpu_atom __initconst = {
1013 	.state_table = atom_cstates,
1014 };
1015 
1016 static const struct idle_cpu idle_cpu_tangier __initconst = {
1017 	.state_table = tangier_cstates,
1018 };
1019 
1020 static const struct idle_cpu idle_cpu_lincroft __initconst = {
1021 	.state_table = atom_cstates,
1022 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
1023 };
1024 
1025 static const struct idle_cpu idle_cpu_snb __initconst = {
1026 	.state_table = snb_cstates,
1027 	.disable_promotion_to_c1e = true,
1028 };
1029 
1030 static const struct idle_cpu idle_cpu_snx __initconst = {
1031 	.state_table = snb_cstates,
1032 	.disable_promotion_to_c1e = true,
1033 	.use_acpi = true,
1034 };
1035 
1036 static const struct idle_cpu idle_cpu_byt __initconst = {
1037 	.state_table = byt_cstates,
1038 	.disable_promotion_to_c1e = true,
1039 	.byt_auto_demotion_disable_flag = true,
1040 };
1041 
1042 static const struct idle_cpu idle_cpu_cht __initconst = {
1043 	.state_table = cht_cstates,
1044 	.disable_promotion_to_c1e = true,
1045 	.byt_auto_demotion_disable_flag = true,
1046 };
1047 
1048 static const struct idle_cpu idle_cpu_ivb __initconst = {
1049 	.state_table = ivb_cstates,
1050 	.disable_promotion_to_c1e = true,
1051 };
1052 
1053 static const struct idle_cpu idle_cpu_ivt __initconst = {
1054 	.state_table = ivt_cstates,
1055 	.disable_promotion_to_c1e = true,
1056 	.use_acpi = true,
1057 };
1058 
1059 static const struct idle_cpu idle_cpu_hsw __initconst = {
1060 	.state_table = hsw_cstates,
1061 	.disable_promotion_to_c1e = true,
1062 };
1063 
1064 static const struct idle_cpu idle_cpu_hsx __initconst = {
1065 	.state_table = hsw_cstates,
1066 	.disable_promotion_to_c1e = true,
1067 	.use_acpi = true,
1068 };
1069 
1070 static const struct idle_cpu idle_cpu_bdw __initconst = {
1071 	.state_table = bdw_cstates,
1072 	.disable_promotion_to_c1e = true,
1073 };
1074 
1075 static const struct idle_cpu idle_cpu_bdx __initconst = {
1076 	.state_table = bdw_cstates,
1077 	.disable_promotion_to_c1e = true,
1078 	.use_acpi = true,
1079 };
1080 
1081 static const struct idle_cpu idle_cpu_skl __initconst = {
1082 	.state_table = skl_cstates,
1083 	.disable_promotion_to_c1e = true,
1084 };
1085 
1086 static const struct idle_cpu idle_cpu_skx __initconst = {
1087 	.state_table = skx_cstates,
1088 	.disable_promotion_to_c1e = true,
1089 	.use_acpi = true,
1090 };
1091 
1092 static const struct idle_cpu idle_cpu_icx __initconst = {
1093 	.state_table = icx_cstates,
1094 	.disable_promotion_to_c1e = true,
1095 	.use_acpi = true,
1096 };
1097 
1098 static const struct idle_cpu idle_cpu_avn __initconst = {
1099 	.state_table = avn_cstates,
1100 	.disable_promotion_to_c1e = true,
1101 	.use_acpi = true,
1102 };
1103 
1104 static const struct idle_cpu idle_cpu_knl __initconst = {
1105 	.state_table = knl_cstates,
1106 	.use_acpi = true,
1107 };
1108 
1109 static const struct idle_cpu idle_cpu_bxt __initconst = {
1110 	.state_table = bxt_cstates,
1111 	.disable_promotion_to_c1e = true,
1112 };
1113 
1114 static const struct idle_cpu idle_cpu_dnv __initconst = {
1115 	.state_table = dnv_cstates,
1116 	.disable_promotion_to_c1e = true,
1117 	.use_acpi = true,
1118 };
1119 
1120 static const struct idle_cpu idle_cpu_snr __initconst = {
1121 	.state_table = snr_cstates,
1122 	.disable_promotion_to_c1e = true,
1123 	.use_acpi = true,
1124 };
1125 
1126 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1127 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EP,		&idle_cpu_nhx),
1128 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM,		&idle_cpu_nehalem),
1129 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_G,		&idle_cpu_nehalem),
1130 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE,		&idle_cpu_nehalem),
1131 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EP,		&idle_cpu_nhx),
1132 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EX,		&idle_cpu_nhx),
1133 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL,	&idle_cpu_atom),
1134 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL_MID,	&idle_cpu_lincroft),
1135 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EX,		&idle_cpu_nhx),
1136 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE,		&idle_cpu_snb),
1137 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE_X,	&idle_cpu_snx),
1138 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SALTWELL,	&idle_cpu_atom),
1139 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	&idle_cpu_byt),
1140 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID,	&idle_cpu_tangier),
1141 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	&idle_cpu_cht),
1142 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE,		&idle_cpu_ivb),
1143 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE_X,		&idle_cpu_ivt),
1144 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL,		&idle_cpu_hsw),
1145 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X,		&idle_cpu_hsx),
1146 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_L,		&idle_cpu_hsw),
1147 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_G,		&idle_cpu_hsw),
1148 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_D,	&idle_cpu_avn),
1149 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL,		&idle_cpu_bdw),
1150 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_G,		&idle_cpu_bdw),
1151 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X,		&idle_cpu_bdx),
1152 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_D,		&idle_cpu_bdx),
1153 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		&idle_cpu_skl),
1154 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		&idle_cpu_skl),
1155 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		&idle_cpu_skl),
1156 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		&idle_cpu_skl),
1157 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X,		&idle_cpu_skx),
1158 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		&idle_cpu_icx),
1159 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D,		&idle_cpu_icx),
1160 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL,	&idle_cpu_knl),
1161 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM,	&idle_cpu_knl),
1162 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	&idle_cpu_bxt),
1163 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_PLUS,	&idle_cpu_bxt),
1164 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D,	&idle_cpu_dnv),
1165 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	&idle_cpu_snr),
1166 	{}
1167 };
1168 
1169 static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
1170 	X86_MATCH_VENDOR_FAM_FEATURE(INTEL, 6, X86_FEATURE_MWAIT, NULL),
1171 	{}
1172 };
1173 
1174 static bool __init intel_idle_max_cstate_reached(int cstate)
1175 {
1176 	if (cstate + 1 > max_cstate) {
1177 		pr_info("max_cstate %d reached\n", max_cstate);
1178 		return true;
1179 	}
1180 	return false;
1181 }
1182 
1183 static bool __init intel_idle_state_needs_timer_stop(struct cpuidle_state *state)
1184 {
1185 	unsigned long eax = flg2MWAIT(state->flags);
1186 
1187 	if (boot_cpu_has(X86_FEATURE_ARAT))
1188 		return false;
1189 
1190 	/*
1191 	 * Switch over to one-shot tick broadcast if the target C-state
1192 	 * is deeper than C1.
1193 	 */
1194 	return !!((eax >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK);
1195 }
1196 
1197 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
1198 #include <acpi/processor.h>
1199 
1200 static bool no_acpi __read_mostly;
1201 module_param(no_acpi, bool, 0444);
1202 MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list");
1203 
1204 static bool force_use_acpi __read_mostly; /* No effect if no_acpi is set. */
1205 module_param_named(use_acpi, force_use_acpi, bool, 0444);
1206 MODULE_PARM_DESC(use_acpi, "Use ACPI _CST for building the idle states list");
1207 
1208 static struct acpi_processor_power acpi_state_table __initdata;
1209 
1210 /**
1211  * intel_idle_cst_usable - Check if the _CST information can be used.
1212  *
1213  * Check if all of the C-states listed by _CST in the max_cstate range are
1214  * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
1215  */
1216 static bool __init intel_idle_cst_usable(void)
1217 {
1218 	int cstate, limit;
1219 
1220 	limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
1221 		      acpi_state_table.count);
1222 
1223 	for (cstate = 1; cstate < limit; cstate++) {
1224 		struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
1225 
1226 		if (cx->entry_method != ACPI_CSTATE_FFH)
1227 			return false;
1228 	}
1229 
1230 	return true;
1231 }
1232 
1233 static bool __init intel_idle_acpi_cst_extract(void)
1234 {
1235 	unsigned int cpu;
1236 
1237 	if (no_acpi) {
1238 		pr_debug("Not allowed to use ACPI _CST\n");
1239 		return false;
1240 	}
1241 
1242 	for_each_possible_cpu(cpu) {
1243 		struct acpi_processor *pr = per_cpu(processors, cpu);
1244 
1245 		if (!pr)
1246 			continue;
1247 
1248 		if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
1249 			continue;
1250 
1251 		acpi_state_table.count++;
1252 
1253 		if (!intel_idle_cst_usable())
1254 			continue;
1255 
1256 		if (!acpi_processor_claim_cst_control())
1257 			break;
1258 
1259 		return true;
1260 	}
1261 
1262 	acpi_state_table.count = 0;
1263 	pr_debug("ACPI _CST not found or not usable\n");
1264 	return false;
1265 }
1266 
1267 static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
1268 {
1269 	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1270 
1271 	/*
1272 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1273 	 * the interesting states are ACPI_CSTATE_FFH.
1274 	 */
1275 	for (cstate = 1; cstate < limit; cstate++) {
1276 		struct acpi_processor_cx *cx;
1277 		struct cpuidle_state *state;
1278 
1279 		if (intel_idle_max_cstate_reached(cstate - 1))
1280 			break;
1281 
1282 		cx = &acpi_state_table.states[cstate];
1283 
1284 		state = &drv->states[drv->state_count++];
1285 
1286 		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
1287 		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1288 		state->exit_latency = cx->latency;
1289 		/*
1290 		 * For C1-type C-states use the same number for both the exit
1291 		 * latency and target residency, because that is the case for
1292 		 * C1 in the majority of the static C-states tables above.
1293 		 * For the other types of C-states, however, set the target
1294 		 * residency to 3 times the exit latency which should lead to
1295 		 * a reasonable balance between energy-efficiency and
1296 		 * performance in the majority of interesting cases.
1297 		 */
1298 		state->target_residency = cx->latency;
1299 		if (cx->type > ACPI_STATE_C1)
1300 			state->target_residency *= 3;
1301 
1302 		state->flags = MWAIT2flg(cx->address);
1303 		if (cx->type > ACPI_STATE_C2)
1304 			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
1305 
1306 		if (disabled_states_mask & BIT(cstate))
1307 			state->flags |= CPUIDLE_FLAG_OFF;
1308 
1309 		if (intel_idle_state_needs_timer_stop(state))
1310 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1311 
1312 		state->enter = intel_idle;
1313 		state->enter_s2idle = intel_idle_s2idle;
1314 	}
1315 }
1316 
1317 static bool __init intel_idle_off_by_default(u32 mwait_hint)
1318 {
1319 	int cstate, limit;
1320 
1321 	/*
1322 	 * If there are no _CST C-states, do not disable any C-states by
1323 	 * default.
1324 	 */
1325 	if (!acpi_state_table.count)
1326 		return false;
1327 
1328 	limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1329 	/*
1330 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1331 	 * the interesting states are ACPI_CSTATE_FFH.
1332 	 */
1333 	for (cstate = 1; cstate < limit; cstate++) {
1334 		if (acpi_state_table.states[cstate].address == mwait_hint)
1335 			return false;
1336 	}
1337 	return true;
1338 }
1339 #else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1340 #define force_use_acpi	(false)
1341 
1342 static inline bool intel_idle_acpi_cst_extract(void) { return false; }
1343 static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
1344 static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
1345 #endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1346 
1347 /**
1348  * ivt_idle_state_table_update - Tune the idle states table for Ivy Town.
1349  *
1350  * Tune IVT multi-socket targets.
1351  * Assumption: num_sockets == (max_package_num + 1).
1352  */
1353 static void __init ivt_idle_state_table_update(void)
1354 {
1355 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1356 	int cpu, package_num, num_sockets = 1;
1357 
1358 	for_each_online_cpu(cpu) {
1359 		package_num = topology_physical_package_id(cpu);
1360 		if (package_num + 1 > num_sockets) {
1361 			num_sockets = package_num + 1;
1362 
1363 			if (num_sockets > 4) {
1364 				cpuidle_state_table = ivt_cstates_8s;
1365 				return;
1366 			}
1367 		}
1368 	}
1369 
1370 	if (num_sockets > 2)
1371 		cpuidle_state_table = ivt_cstates_4s;
1372 
1373 	/* else, 1 and 2 socket systems use default ivt_cstates */
1374 }
1375 
1376 /**
1377  * irtl_2_usec - IRTL to microseconds conversion.
1378  * @irtl: IRTL MSR value.
1379  *
1380  * Translate the IRTL (Interrupt Response Time Limit) MSR value to microseconds.
1381  */
1382 static unsigned long long __init irtl_2_usec(unsigned long long irtl)
1383 {
1384 	static const unsigned int irtl_ns_units[] __initconst = {
1385 		1, 32, 1024, 32768, 1048576, 33554432, 0, 0
1386 	};
1387 	unsigned long long ns;
1388 
1389 	if (!irtl)
1390 		return 0;
1391 
1392 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1393 
1394 	return div_u64((irtl & 0x3FF) * ns, NSEC_PER_USEC);
1395 }
1396 
1397 /**
1398  * bxt_idle_state_table_update - Fix up the Broxton idle states table.
1399  *
1400  * On BXT, trust the IRTL (Interrupt Response Time Limit) MSR to show the
1401  * definitive maximum latency and use the same value for target_residency.
1402  */
1403 static void __init bxt_idle_state_table_update(void)
1404 {
1405 	unsigned long long msr;
1406 	unsigned int usec;
1407 
1408 	rdmsrl(MSR_PKGC6_IRTL, msr);
1409 	usec = irtl_2_usec(msr);
1410 	if (usec) {
1411 		bxt_cstates[2].exit_latency = usec;
1412 		bxt_cstates[2].target_residency = usec;
1413 	}
1414 
1415 	rdmsrl(MSR_PKGC7_IRTL, msr);
1416 	usec = irtl_2_usec(msr);
1417 	if (usec) {
1418 		bxt_cstates[3].exit_latency = usec;
1419 		bxt_cstates[3].target_residency = usec;
1420 	}
1421 
1422 	rdmsrl(MSR_PKGC8_IRTL, msr);
1423 	usec = irtl_2_usec(msr);
1424 	if (usec) {
1425 		bxt_cstates[4].exit_latency = usec;
1426 		bxt_cstates[4].target_residency = usec;
1427 	}
1428 
1429 	rdmsrl(MSR_PKGC9_IRTL, msr);
1430 	usec = irtl_2_usec(msr);
1431 	if (usec) {
1432 		bxt_cstates[5].exit_latency = usec;
1433 		bxt_cstates[5].target_residency = usec;
1434 	}
1435 
1436 	rdmsrl(MSR_PKGC10_IRTL, msr);
1437 	usec = irtl_2_usec(msr);
1438 	if (usec) {
1439 		bxt_cstates[6].exit_latency = usec;
1440 		bxt_cstates[6].target_residency = usec;
1441 	}
1442 
1443 }
1444 
1445 /**
1446  * sklh_idle_state_table_update - Fix up the Sky Lake idle states table.
1447  *
1448  * On SKL-H (model 0x5e) skip C8 and C9 if C10 is enabled and SGX disabled.
1449  */
1450 static void __init sklh_idle_state_table_update(void)
1451 {
1452 	unsigned long long msr;
1453 	unsigned int eax, ebx, ecx, edx;
1454 
1455 
1456 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1457 	if (max_cstate <= 7)
1458 		return;
1459 
1460 	/* if PC10 not present in CPUID.MWAIT.EDX */
1461 	if ((mwait_substates & (0xF << 28)) == 0)
1462 		return;
1463 
1464 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1465 
1466 	/* PC10 is not enabled in PKG C-state limit */
1467 	if ((msr & 0xF) != 8)
1468 		return;
1469 
1470 	ecx = 0;
1471 	cpuid(7, &eax, &ebx, &ecx, &edx);
1472 
1473 	/* if SGX is present */
1474 	if (ebx & (1 << 2)) {
1475 
1476 		rdmsrl(MSR_IA32_FEAT_CTL, msr);
1477 
1478 		/* if SGX is enabled */
1479 		if (msr & (1 << 18))
1480 			return;
1481 	}
1482 
1483 	skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C8-SKL */
1484 	skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C9-SKL */
1485 }
1486 
1487 static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
1488 {
1489 	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
1490 	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
1491 					MWAIT_SUBSTATE_MASK;
1492 
1493 	/* Ignore the C-state if there are NO sub-states in CPUID for it. */
1494 	if (num_substates == 0)
1495 		return false;
1496 
1497 	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1498 		mark_tsc_unstable("TSC halts in idle states deeper than C2");
1499 
1500 	return true;
1501 }
1502 
1503 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
1504 {
1505 	int cstate;
1506 
1507 	switch (boot_cpu_data.x86_model) {
1508 	case INTEL_FAM6_IVYBRIDGE_X:
1509 		ivt_idle_state_table_update();
1510 		break;
1511 	case INTEL_FAM6_ATOM_GOLDMONT:
1512 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1513 		bxt_idle_state_table_update();
1514 		break;
1515 	case INTEL_FAM6_SKYLAKE:
1516 		sklh_idle_state_table_update();
1517 		break;
1518 	}
1519 
1520 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1521 		unsigned int mwait_hint;
1522 
1523 		if (intel_idle_max_cstate_reached(cstate))
1524 			break;
1525 
1526 		if (!cpuidle_state_table[cstate].enter &&
1527 		    !cpuidle_state_table[cstate].enter_s2idle)
1528 			break;
1529 
1530 		/* If marked as unusable, skip this state. */
1531 		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
1532 			pr_debug("state %s is disabled\n",
1533 				 cpuidle_state_table[cstate].name);
1534 			continue;
1535 		}
1536 
1537 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1538 		if (!intel_idle_verify_cstate(mwait_hint))
1539 			continue;
1540 
1541 		/* Structure copy. */
1542 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
1543 
1544 		if ((disabled_states_mask & BIT(drv->state_count)) ||
1545 		    ((icpu->use_acpi || force_use_acpi) &&
1546 		     intel_idle_off_by_default(mwait_hint) &&
1547 		     !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE)))
1548 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF;
1549 
1550 		if (intel_idle_state_needs_timer_stop(&drv->states[drv->state_count]))
1551 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_TIMER_STOP;
1552 
1553 		drv->state_count++;
1554 	}
1555 
1556 	if (icpu->byt_auto_demotion_disable_flag) {
1557 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1558 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1559 	}
1560 }
1561 
1562 /**
1563  * intel_idle_cpuidle_driver_init - Create the list of available idle states.
1564  * @drv: cpuidle driver structure to initialize.
1565  */
1566 static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
1567 {
1568 	cpuidle_poll_state_init(drv);
1569 
1570 	if (disabled_states_mask & BIT(0))
1571 		drv->states[0].flags |= CPUIDLE_FLAG_OFF;
1572 
1573 	drv->state_count = 1;
1574 
1575 	if (icpu)
1576 		intel_idle_init_cstates_icpu(drv);
1577 	else
1578 		intel_idle_init_cstates_acpi(drv);
1579 }
1580 
1581 static void auto_demotion_disable(void)
1582 {
1583 	unsigned long long msr_bits;
1584 
1585 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1586 	msr_bits &= ~auto_demotion_disable_flags;
1587 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1588 }
1589 
1590 static void c1e_promotion_disable(void)
1591 {
1592 	unsigned long long msr_bits;
1593 
1594 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
1595 	msr_bits &= ~0x2;
1596 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
1597 }
1598 
1599 /**
1600  * intel_idle_cpu_init - Register the target CPU with the cpuidle core.
1601  * @cpu: CPU to initialize.
1602  *
1603  * Register a cpuidle device object for @cpu and update its MSRs in accordance
1604  * with the processor model flags.
1605  */
1606 static int intel_idle_cpu_init(unsigned int cpu)
1607 {
1608 	struct cpuidle_device *dev;
1609 
1610 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1611 	dev->cpu = cpu;
1612 
1613 	if (cpuidle_register_device(dev)) {
1614 		pr_debug("cpuidle_register_device %d failed!\n", cpu);
1615 		return -EIO;
1616 	}
1617 
1618 	if (auto_demotion_disable_flags)
1619 		auto_demotion_disable();
1620 
1621 	if (disable_promotion_to_c1e)
1622 		c1e_promotion_disable();
1623 
1624 	return 0;
1625 }
1626 
1627 static int intel_idle_cpu_online(unsigned int cpu)
1628 {
1629 	struct cpuidle_device *dev;
1630 
1631 	if (!boot_cpu_has(X86_FEATURE_ARAT))
1632 		tick_broadcast_enable();
1633 
1634 	/*
1635 	 * Some systems can hotplug a cpu at runtime after
1636 	 * the kernel has booted, we have to initialize the
1637 	 * driver in this case
1638 	 */
1639 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1640 	if (!dev->registered)
1641 		return intel_idle_cpu_init(cpu);
1642 
1643 	return 0;
1644 }
1645 
1646 /**
1647  * intel_idle_cpuidle_devices_uninit - Unregister all cpuidle devices.
1648  */
1649 static void __init intel_idle_cpuidle_devices_uninit(void)
1650 {
1651 	int i;
1652 
1653 	for_each_online_cpu(i)
1654 		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
1655 }
1656 
1657 static int __init intel_idle_init(void)
1658 {
1659 	const struct x86_cpu_id *id;
1660 	unsigned int eax, ebx, ecx;
1661 	int retval;
1662 
1663 	/* Do not load intel_idle at all for now if idle= is passed */
1664 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1665 		return -ENODEV;
1666 
1667 	if (max_cstate == 0) {
1668 		pr_debug("disabled\n");
1669 		return -EPERM;
1670 	}
1671 
1672 	id = x86_match_cpu(intel_idle_ids);
1673 	if (id) {
1674 		if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1675 			pr_debug("Please enable MWAIT in BIOS SETUP\n");
1676 			return -ENODEV;
1677 		}
1678 	} else {
1679 		id = x86_match_cpu(intel_mwait_ids);
1680 		if (!id)
1681 			return -ENODEV;
1682 	}
1683 
1684 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1685 		return -ENODEV;
1686 
1687 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1688 
1689 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1690 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1691 	    !mwait_substates)
1692 			return -ENODEV;
1693 
1694 	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1695 
1696 	icpu = (const struct idle_cpu *)id->driver_data;
1697 	if (icpu) {
1698 		cpuidle_state_table = icpu->state_table;
1699 		auto_demotion_disable_flags = icpu->auto_demotion_disable_flags;
1700 		disable_promotion_to_c1e = icpu->disable_promotion_to_c1e;
1701 		if (icpu->use_acpi || force_use_acpi)
1702 			intel_idle_acpi_cst_extract();
1703 	} else if (!intel_idle_acpi_cst_extract()) {
1704 		return -ENODEV;
1705 	}
1706 
1707 	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1708 		 boot_cpu_data.x86_model);
1709 
1710 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1711 	if (!intel_idle_cpuidle_devices)
1712 		return -ENOMEM;
1713 
1714 	intel_idle_cpuidle_driver_init(&intel_idle_driver);
1715 
1716 	retval = cpuidle_register_driver(&intel_idle_driver);
1717 	if (retval) {
1718 		struct cpuidle_driver *drv = cpuidle_get_driver();
1719 		printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1720 		       drv ? drv->name : "none");
1721 		goto init_driver_fail;
1722 	}
1723 
1724 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1725 				   intel_idle_cpu_online, NULL);
1726 	if (retval < 0)
1727 		goto hp_setup_fail;
1728 
1729 	pr_debug("Local APIC timer is reliable in %s\n",
1730 		 boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
1731 
1732 	return 0;
1733 
1734 hp_setup_fail:
1735 	intel_idle_cpuidle_devices_uninit();
1736 	cpuidle_unregister_driver(&intel_idle_driver);
1737 init_driver_fail:
1738 	free_percpu(intel_idle_cpuidle_devices);
1739 	return retval;
1740 
1741 }
1742 device_initcall(intel_idle_init);
1743 
1744 /*
1745  * We are not really modular, but we used to support that.  Meaning we also
1746  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1747  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1748  * is the easiest way (currently) to continue doing that.
1749  */
1750 module_param(max_cstate, int, 0444);
1751 /*
1752  * The positions of the bits that are set in this number are the indices of the
1753  * idle states to be disabled by default (as reflected by the names of the
1754  * corresponding idle state directories in sysfs, "state0", "state1" ...
1755  * "state<i>" ..., where <i> is the index of the given state).
1756  */
1757 module_param_named(states_off, disabled_states_mask, uint, 0444);
1758 MODULE_PARM_DESC(states_off, "Mask of disabled idle states");
1759