xref: /openbmc/linux/drivers/idle/intel_idle.c (revision aa6159ab)
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 = 128,
748 		.target_residency = 384,
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 static const struct idle_cpu idle_cpu_nehalem __initconst = {
967 	.state_table = nehalem_cstates,
968 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
969 	.disable_promotion_to_c1e = true,
970 };
971 
972 static const struct idle_cpu idle_cpu_nhx __initconst = {
973 	.state_table = nehalem_cstates,
974 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
975 	.disable_promotion_to_c1e = true,
976 	.use_acpi = true,
977 };
978 
979 static const struct idle_cpu idle_cpu_atom __initconst = {
980 	.state_table = atom_cstates,
981 };
982 
983 static const struct idle_cpu idle_cpu_tangier __initconst = {
984 	.state_table = tangier_cstates,
985 };
986 
987 static const struct idle_cpu idle_cpu_lincroft __initconst = {
988 	.state_table = atom_cstates,
989 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
990 };
991 
992 static const struct idle_cpu idle_cpu_snb __initconst = {
993 	.state_table = snb_cstates,
994 	.disable_promotion_to_c1e = true,
995 };
996 
997 static const struct idle_cpu idle_cpu_snx __initconst = {
998 	.state_table = snb_cstates,
999 	.disable_promotion_to_c1e = true,
1000 	.use_acpi = true,
1001 };
1002 
1003 static const struct idle_cpu idle_cpu_byt __initconst = {
1004 	.state_table = byt_cstates,
1005 	.disable_promotion_to_c1e = true,
1006 	.byt_auto_demotion_disable_flag = true,
1007 };
1008 
1009 static const struct idle_cpu idle_cpu_cht __initconst = {
1010 	.state_table = cht_cstates,
1011 	.disable_promotion_to_c1e = true,
1012 	.byt_auto_demotion_disable_flag = true,
1013 };
1014 
1015 static const struct idle_cpu idle_cpu_ivb __initconst = {
1016 	.state_table = ivb_cstates,
1017 	.disable_promotion_to_c1e = true,
1018 };
1019 
1020 static const struct idle_cpu idle_cpu_ivt __initconst = {
1021 	.state_table = ivt_cstates,
1022 	.disable_promotion_to_c1e = true,
1023 	.use_acpi = true,
1024 };
1025 
1026 static const struct idle_cpu idle_cpu_hsw __initconst = {
1027 	.state_table = hsw_cstates,
1028 	.disable_promotion_to_c1e = true,
1029 };
1030 
1031 static const struct idle_cpu idle_cpu_hsx __initconst = {
1032 	.state_table = hsw_cstates,
1033 	.disable_promotion_to_c1e = true,
1034 	.use_acpi = true,
1035 };
1036 
1037 static const struct idle_cpu idle_cpu_bdw __initconst = {
1038 	.state_table = bdw_cstates,
1039 	.disable_promotion_to_c1e = true,
1040 };
1041 
1042 static const struct idle_cpu idle_cpu_bdx __initconst = {
1043 	.state_table = bdw_cstates,
1044 	.disable_promotion_to_c1e = true,
1045 	.use_acpi = true,
1046 };
1047 
1048 static const struct idle_cpu idle_cpu_skl __initconst = {
1049 	.state_table = skl_cstates,
1050 	.disable_promotion_to_c1e = true,
1051 };
1052 
1053 static const struct idle_cpu idle_cpu_skx __initconst = {
1054 	.state_table = skx_cstates,
1055 	.disable_promotion_to_c1e = true,
1056 	.use_acpi = true,
1057 };
1058 
1059 static const struct idle_cpu idle_cpu_icx __initconst = {
1060 	.state_table = icx_cstates,
1061 	.disable_promotion_to_c1e = true,
1062 	.use_acpi = true,
1063 };
1064 
1065 static const struct idle_cpu idle_cpu_avn __initconst = {
1066 	.state_table = avn_cstates,
1067 	.disable_promotion_to_c1e = true,
1068 	.use_acpi = true,
1069 };
1070 
1071 static const struct idle_cpu idle_cpu_knl __initconst = {
1072 	.state_table = knl_cstates,
1073 	.use_acpi = true,
1074 };
1075 
1076 static const struct idle_cpu idle_cpu_bxt __initconst = {
1077 	.state_table = bxt_cstates,
1078 	.disable_promotion_to_c1e = true,
1079 };
1080 
1081 static const struct idle_cpu idle_cpu_dnv __initconst = {
1082 	.state_table = dnv_cstates,
1083 	.disable_promotion_to_c1e = true,
1084 	.use_acpi = true,
1085 };
1086 
1087 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1088 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EP,		&idle_cpu_nhx),
1089 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM,		&idle_cpu_nehalem),
1090 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_G,		&idle_cpu_nehalem),
1091 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE,		&idle_cpu_nehalem),
1092 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EP,		&idle_cpu_nhx),
1093 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EX,		&idle_cpu_nhx),
1094 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL,	&idle_cpu_atom),
1095 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL_MID,	&idle_cpu_lincroft),
1096 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EX,		&idle_cpu_nhx),
1097 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE,		&idle_cpu_snb),
1098 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE_X,	&idle_cpu_snx),
1099 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SALTWELL,	&idle_cpu_atom),
1100 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	&idle_cpu_byt),
1101 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID,	&idle_cpu_tangier),
1102 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	&idle_cpu_cht),
1103 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE,		&idle_cpu_ivb),
1104 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE_X,		&idle_cpu_ivt),
1105 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL,		&idle_cpu_hsw),
1106 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X,		&idle_cpu_hsx),
1107 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_L,		&idle_cpu_hsw),
1108 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_G,		&idle_cpu_hsw),
1109 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_D,	&idle_cpu_avn),
1110 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL,		&idle_cpu_bdw),
1111 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_G,		&idle_cpu_bdw),
1112 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X,		&idle_cpu_bdx),
1113 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_D,		&idle_cpu_bdx),
1114 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		&idle_cpu_skl),
1115 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		&idle_cpu_skl),
1116 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		&idle_cpu_skl),
1117 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		&idle_cpu_skl),
1118 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X,		&idle_cpu_skx),
1119 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		&idle_cpu_icx),
1120 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL,	&idle_cpu_knl),
1121 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM,	&idle_cpu_knl),
1122 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	&idle_cpu_bxt),
1123 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_PLUS,	&idle_cpu_bxt),
1124 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D,	&idle_cpu_dnv),
1125 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	&idle_cpu_dnv),
1126 	{}
1127 };
1128 
1129 static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
1130 	X86_MATCH_VENDOR_FAM_FEATURE(INTEL, 6, X86_FEATURE_MWAIT, NULL),
1131 	{}
1132 };
1133 
1134 static bool __init intel_idle_max_cstate_reached(int cstate)
1135 {
1136 	if (cstate + 1 > max_cstate) {
1137 		pr_info("max_cstate %d reached\n", max_cstate);
1138 		return true;
1139 	}
1140 	return false;
1141 }
1142 
1143 static bool __init intel_idle_state_needs_timer_stop(struct cpuidle_state *state)
1144 {
1145 	unsigned long eax = flg2MWAIT(state->flags);
1146 
1147 	if (boot_cpu_has(X86_FEATURE_ARAT))
1148 		return false;
1149 
1150 	/*
1151 	 * Switch over to one-shot tick broadcast if the target C-state
1152 	 * is deeper than C1.
1153 	 */
1154 	return !!((eax >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK);
1155 }
1156 
1157 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
1158 #include <acpi/processor.h>
1159 
1160 static bool no_acpi __read_mostly;
1161 module_param(no_acpi, bool, 0444);
1162 MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list");
1163 
1164 static bool force_use_acpi __read_mostly; /* No effect if no_acpi is set. */
1165 module_param_named(use_acpi, force_use_acpi, bool, 0444);
1166 MODULE_PARM_DESC(use_acpi, "Use ACPI _CST for building the idle states list");
1167 
1168 static struct acpi_processor_power acpi_state_table __initdata;
1169 
1170 /**
1171  * intel_idle_cst_usable - Check if the _CST information can be used.
1172  *
1173  * Check if all of the C-states listed by _CST in the max_cstate range are
1174  * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
1175  */
1176 static bool __init intel_idle_cst_usable(void)
1177 {
1178 	int cstate, limit;
1179 
1180 	limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
1181 		      acpi_state_table.count);
1182 
1183 	for (cstate = 1; cstate < limit; cstate++) {
1184 		struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
1185 
1186 		if (cx->entry_method != ACPI_CSTATE_FFH)
1187 			return false;
1188 	}
1189 
1190 	return true;
1191 }
1192 
1193 static bool __init intel_idle_acpi_cst_extract(void)
1194 {
1195 	unsigned int cpu;
1196 
1197 	if (no_acpi) {
1198 		pr_debug("Not allowed to use ACPI _CST\n");
1199 		return false;
1200 	}
1201 
1202 	for_each_possible_cpu(cpu) {
1203 		struct acpi_processor *pr = per_cpu(processors, cpu);
1204 
1205 		if (!pr)
1206 			continue;
1207 
1208 		if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
1209 			continue;
1210 
1211 		acpi_state_table.count++;
1212 
1213 		if (!intel_idle_cst_usable())
1214 			continue;
1215 
1216 		if (!acpi_processor_claim_cst_control())
1217 			break;
1218 
1219 		return true;
1220 	}
1221 
1222 	acpi_state_table.count = 0;
1223 	pr_debug("ACPI _CST not found or not usable\n");
1224 	return false;
1225 }
1226 
1227 static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
1228 {
1229 	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1230 
1231 	/*
1232 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1233 	 * the interesting states are ACPI_CSTATE_FFH.
1234 	 */
1235 	for (cstate = 1; cstate < limit; cstate++) {
1236 		struct acpi_processor_cx *cx;
1237 		struct cpuidle_state *state;
1238 
1239 		if (intel_idle_max_cstate_reached(cstate - 1))
1240 			break;
1241 
1242 		cx = &acpi_state_table.states[cstate];
1243 
1244 		state = &drv->states[drv->state_count++];
1245 
1246 		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
1247 		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1248 		state->exit_latency = cx->latency;
1249 		/*
1250 		 * For C1-type C-states use the same number for both the exit
1251 		 * latency and target residency, because that is the case for
1252 		 * C1 in the majority of the static C-states tables above.
1253 		 * For the other types of C-states, however, set the target
1254 		 * residency to 3 times the exit latency which should lead to
1255 		 * a reasonable balance between energy-efficiency and
1256 		 * performance in the majority of interesting cases.
1257 		 */
1258 		state->target_residency = cx->latency;
1259 		if (cx->type > ACPI_STATE_C1)
1260 			state->target_residency *= 3;
1261 
1262 		state->flags = MWAIT2flg(cx->address);
1263 		if (cx->type > ACPI_STATE_C2)
1264 			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
1265 
1266 		if (disabled_states_mask & BIT(cstate))
1267 			state->flags |= CPUIDLE_FLAG_OFF;
1268 
1269 		if (intel_idle_state_needs_timer_stop(state))
1270 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1271 
1272 		state->enter = intel_idle;
1273 		state->enter_s2idle = intel_idle_s2idle;
1274 	}
1275 }
1276 
1277 static bool __init intel_idle_off_by_default(u32 mwait_hint)
1278 {
1279 	int cstate, limit;
1280 
1281 	/*
1282 	 * If there are no _CST C-states, do not disable any C-states by
1283 	 * default.
1284 	 */
1285 	if (!acpi_state_table.count)
1286 		return false;
1287 
1288 	limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1289 	/*
1290 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1291 	 * the interesting states are ACPI_CSTATE_FFH.
1292 	 */
1293 	for (cstate = 1; cstate < limit; cstate++) {
1294 		if (acpi_state_table.states[cstate].address == mwait_hint)
1295 			return false;
1296 	}
1297 	return true;
1298 }
1299 #else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1300 #define force_use_acpi	(false)
1301 
1302 static inline bool intel_idle_acpi_cst_extract(void) { return false; }
1303 static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
1304 static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
1305 #endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1306 
1307 /**
1308  * ivt_idle_state_table_update - Tune the idle states table for Ivy Town.
1309  *
1310  * Tune IVT multi-socket targets.
1311  * Assumption: num_sockets == (max_package_num + 1).
1312  */
1313 static void __init ivt_idle_state_table_update(void)
1314 {
1315 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1316 	int cpu, package_num, num_sockets = 1;
1317 
1318 	for_each_online_cpu(cpu) {
1319 		package_num = topology_physical_package_id(cpu);
1320 		if (package_num + 1 > num_sockets) {
1321 			num_sockets = package_num + 1;
1322 
1323 			if (num_sockets > 4) {
1324 				cpuidle_state_table = ivt_cstates_8s;
1325 				return;
1326 			}
1327 		}
1328 	}
1329 
1330 	if (num_sockets > 2)
1331 		cpuidle_state_table = ivt_cstates_4s;
1332 
1333 	/* else, 1 and 2 socket systems use default ivt_cstates */
1334 }
1335 
1336 /**
1337  * irtl_2_usec - IRTL to microseconds conversion.
1338  * @irtl: IRTL MSR value.
1339  *
1340  * Translate the IRTL (Interrupt Response Time Limit) MSR value to microseconds.
1341  */
1342 static unsigned long long __init irtl_2_usec(unsigned long long irtl)
1343 {
1344 	static const unsigned int irtl_ns_units[] __initconst = {
1345 		1, 32, 1024, 32768, 1048576, 33554432, 0, 0
1346 	};
1347 	unsigned long long ns;
1348 
1349 	if (!irtl)
1350 		return 0;
1351 
1352 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1353 
1354 	return div_u64((irtl & 0x3FF) * ns, NSEC_PER_USEC);
1355 }
1356 
1357 /**
1358  * bxt_idle_state_table_update - Fix up the Broxton idle states table.
1359  *
1360  * On BXT, trust the IRTL (Interrupt Response Time Limit) MSR to show the
1361  * definitive maximum latency and use the same value for target_residency.
1362  */
1363 static void __init bxt_idle_state_table_update(void)
1364 {
1365 	unsigned long long msr;
1366 	unsigned int usec;
1367 
1368 	rdmsrl(MSR_PKGC6_IRTL, msr);
1369 	usec = irtl_2_usec(msr);
1370 	if (usec) {
1371 		bxt_cstates[2].exit_latency = usec;
1372 		bxt_cstates[2].target_residency = usec;
1373 	}
1374 
1375 	rdmsrl(MSR_PKGC7_IRTL, msr);
1376 	usec = irtl_2_usec(msr);
1377 	if (usec) {
1378 		bxt_cstates[3].exit_latency = usec;
1379 		bxt_cstates[3].target_residency = usec;
1380 	}
1381 
1382 	rdmsrl(MSR_PKGC8_IRTL, msr);
1383 	usec = irtl_2_usec(msr);
1384 	if (usec) {
1385 		bxt_cstates[4].exit_latency = usec;
1386 		bxt_cstates[4].target_residency = usec;
1387 	}
1388 
1389 	rdmsrl(MSR_PKGC9_IRTL, msr);
1390 	usec = irtl_2_usec(msr);
1391 	if (usec) {
1392 		bxt_cstates[5].exit_latency = usec;
1393 		bxt_cstates[5].target_residency = usec;
1394 	}
1395 
1396 	rdmsrl(MSR_PKGC10_IRTL, msr);
1397 	usec = irtl_2_usec(msr);
1398 	if (usec) {
1399 		bxt_cstates[6].exit_latency = usec;
1400 		bxt_cstates[6].target_residency = usec;
1401 	}
1402 
1403 }
1404 
1405 /**
1406  * sklh_idle_state_table_update - Fix up the Sky Lake idle states table.
1407  *
1408  * On SKL-H (model 0x5e) skip C8 and C9 if C10 is enabled and SGX disabled.
1409  */
1410 static void __init sklh_idle_state_table_update(void)
1411 {
1412 	unsigned long long msr;
1413 	unsigned int eax, ebx, ecx, edx;
1414 
1415 
1416 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1417 	if (max_cstate <= 7)
1418 		return;
1419 
1420 	/* if PC10 not present in CPUID.MWAIT.EDX */
1421 	if ((mwait_substates & (0xF << 28)) == 0)
1422 		return;
1423 
1424 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1425 
1426 	/* PC10 is not enabled in PKG C-state limit */
1427 	if ((msr & 0xF) != 8)
1428 		return;
1429 
1430 	ecx = 0;
1431 	cpuid(7, &eax, &ebx, &ecx, &edx);
1432 
1433 	/* if SGX is present */
1434 	if (ebx & (1 << 2)) {
1435 
1436 		rdmsrl(MSR_IA32_FEAT_CTL, msr);
1437 
1438 		/* if SGX is enabled */
1439 		if (msr & (1 << 18))
1440 			return;
1441 	}
1442 
1443 	skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C8-SKL */
1444 	skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C9-SKL */
1445 }
1446 
1447 static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
1448 {
1449 	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
1450 	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
1451 					MWAIT_SUBSTATE_MASK;
1452 
1453 	/* Ignore the C-state if there are NO sub-states in CPUID for it. */
1454 	if (num_substates == 0)
1455 		return false;
1456 
1457 	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1458 		mark_tsc_unstable("TSC halts in idle states deeper than C2");
1459 
1460 	return true;
1461 }
1462 
1463 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
1464 {
1465 	int cstate;
1466 
1467 	switch (boot_cpu_data.x86_model) {
1468 	case INTEL_FAM6_IVYBRIDGE_X:
1469 		ivt_idle_state_table_update();
1470 		break;
1471 	case INTEL_FAM6_ATOM_GOLDMONT:
1472 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1473 		bxt_idle_state_table_update();
1474 		break;
1475 	case INTEL_FAM6_SKYLAKE:
1476 		sklh_idle_state_table_update();
1477 		break;
1478 	}
1479 
1480 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1481 		unsigned int mwait_hint;
1482 
1483 		if (intel_idle_max_cstate_reached(cstate))
1484 			break;
1485 
1486 		if (!cpuidle_state_table[cstate].enter &&
1487 		    !cpuidle_state_table[cstate].enter_s2idle)
1488 			break;
1489 
1490 		/* If marked as unusable, skip this state. */
1491 		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
1492 			pr_debug("state %s is disabled\n",
1493 				 cpuidle_state_table[cstate].name);
1494 			continue;
1495 		}
1496 
1497 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1498 		if (!intel_idle_verify_cstate(mwait_hint))
1499 			continue;
1500 
1501 		/* Structure copy. */
1502 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
1503 
1504 		if ((disabled_states_mask & BIT(drv->state_count)) ||
1505 		    ((icpu->use_acpi || force_use_acpi) &&
1506 		     intel_idle_off_by_default(mwait_hint) &&
1507 		     !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE)))
1508 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF;
1509 
1510 		if (intel_idle_state_needs_timer_stop(&drv->states[drv->state_count]))
1511 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_TIMER_STOP;
1512 
1513 		drv->state_count++;
1514 	}
1515 
1516 	if (icpu->byt_auto_demotion_disable_flag) {
1517 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1518 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1519 	}
1520 }
1521 
1522 /**
1523  * intel_idle_cpuidle_driver_init - Create the list of available idle states.
1524  * @drv: cpuidle driver structure to initialize.
1525  */
1526 static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
1527 {
1528 	cpuidle_poll_state_init(drv);
1529 
1530 	if (disabled_states_mask & BIT(0))
1531 		drv->states[0].flags |= CPUIDLE_FLAG_OFF;
1532 
1533 	drv->state_count = 1;
1534 
1535 	if (icpu)
1536 		intel_idle_init_cstates_icpu(drv);
1537 	else
1538 		intel_idle_init_cstates_acpi(drv);
1539 }
1540 
1541 static void auto_demotion_disable(void)
1542 {
1543 	unsigned long long msr_bits;
1544 
1545 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1546 	msr_bits &= ~auto_demotion_disable_flags;
1547 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1548 }
1549 
1550 static void c1e_promotion_disable(void)
1551 {
1552 	unsigned long long msr_bits;
1553 
1554 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
1555 	msr_bits &= ~0x2;
1556 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
1557 }
1558 
1559 /**
1560  * intel_idle_cpu_init - Register the target CPU with the cpuidle core.
1561  * @cpu: CPU to initialize.
1562  *
1563  * Register a cpuidle device object for @cpu and update its MSRs in accordance
1564  * with the processor model flags.
1565  */
1566 static int intel_idle_cpu_init(unsigned int cpu)
1567 {
1568 	struct cpuidle_device *dev;
1569 
1570 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1571 	dev->cpu = cpu;
1572 
1573 	if (cpuidle_register_device(dev)) {
1574 		pr_debug("cpuidle_register_device %d failed!\n", cpu);
1575 		return -EIO;
1576 	}
1577 
1578 	if (auto_demotion_disable_flags)
1579 		auto_demotion_disable();
1580 
1581 	if (disable_promotion_to_c1e)
1582 		c1e_promotion_disable();
1583 
1584 	return 0;
1585 }
1586 
1587 static int intel_idle_cpu_online(unsigned int cpu)
1588 {
1589 	struct cpuidle_device *dev;
1590 
1591 	if (!boot_cpu_has(X86_FEATURE_ARAT))
1592 		tick_broadcast_enable();
1593 
1594 	/*
1595 	 * Some systems can hotplug a cpu at runtime after
1596 	 * the kernel has booted, we have to initialize the
1597 	 * driver in this case
1598 	 */
1599 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1600 	if (!dev->registered)
1601 		return intel_idle_cpu_init(cpu);
1602 
1603 	return 0;
1604 }
1605 
1606 /**
1607  * intel_idle_cpuidle_devices_uninit - Unregister all cpuidle devices.
1608  */
1609 static void __init intel_idle_cpuidle_devices_uninit(void)
1610 {
1611 	int i;
1612 
1613 	for_each_online_cpu(i)
1614 		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
1615 }
1616 
1617 static int __init intel_idle_init(void)
1618 {
1619 	const struct x86_cpu_id *id;
1620 	unsigned int eax, ebx, ecx;
1621 	int retval;
1622 
1623 	/* Do not load intel_idle at all for now if idle= is passed */
1624 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1625 		return -ENODEV;
1626 
1627 	if (max_cstate == 0) {
1628 		pr_debug("disabled\n");
1629 		return -EPERM;
1630 	}
1631 
1632 	id = x86_match_cpu(intel_idle_ids);
1633 	if (id) {
1634 		if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1635 			pr_debug("Please enable MWAIT in BIOS SETUP\n");
1636 			return -ENODEV;
1637 		}
1638 	} else {
1639 		id = x86_match_cpu(intel_mwait_ids);
1640 		if (!id)
1641 			return -ENODEV;
1642 	}
1643 
1644 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1645 		return -ENODEV;
1646 
1647 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1648 
1649 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1650 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1651 	    !mwait_substates)
1652 			return -ENODEV;
1653 
1654 	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1655 
1656 	icpu = (const struct idle_cpu *)id->driver_data;
1657 	if (icpu) {
1658 		cpuidle_state_table = icpu->state_table;
1659 		auto_demotion_disable_flags = icpu->auto_demotion_disable_flags;
1660 		disable_promotion_to_c1e = icpu->disable_promotion_to_c1e;
1661 		if (icpu->use_acpi || force_use_acpi)
1662 			intel_idle_acpi_cst_extract();
1663 	} else if (!intel_idle_acpi_cst_extract()) {
1664 		return -ENODEV;
1665 	}
1666 
1667 	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1668 		 boot_cpu_data.x86_model);
1669 
1670 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1671 	if (!intel_idle_cpuidle_devices)
1672 		return -ENOMEM;
1673 
1674 	intel_idle_cpuidle_driver_init(&intel_idle_driver);
1675 
1676 	retval = cpuidle_register_driver(&intel_idle_driver);
1677 	if (retval) {
1678 		struct cpuidle_driver *drv = cpuidle_get_driver();
1679 		printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1680 		       drv ? drv->name : "none");
1681 		goto init_driver_fail;
1682 	}
1683 
1684 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1685 				   intel_idle_cpu_online, NULL);
1686 	if (retval < 0)
1687 		goto hp_setup_fail;
1688 
1689 	pr_debug("Local APIC timer is reliable in %s\n",
1690 		 boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
1691 
1692 	return 0;
1693 
1694 hp_setup_fail:
1695 	intel_idle_cpuidle_devices_uninit();
1696 	cpuidle_unregister_driver(&intel_idle_driver);
1697 init_driver_fail:
1698 	free_percpu(intel_idle_cpuidle_devices);
1699 	return retval;
1700 
1701 }
1702 device_initcall(intel_idle_init);
1703 
1704 /*
1705  * We are not really modular, but we used to support that.  Meaning we also
1706  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1707  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1708  * is the easiest way (currently) to continue doing that.
1709  */
1710 module_param(max_cstate, int, 0444);
1711 /*
1712  * The positions of the bits that are set in this number are the indices of the
1713  * idle states to be disabled by default (as reflected by the names of the
1714  * corresponding idle state directories in sysfs, "state0", "state1" ...
1715  * "state<i>" ..., where <i> is the index of the given state).
1716  */
1717 module_param_named(states_off, disabled_states_mask, uint, 0444);
1718 MODULE_PARM_DESC(states_off, "Mask of disabled idle states");
1719