xref: /linux/drivers/idle/intel_idle.c (revision f69e98a91a01fd7c5755dd710e94a17d6e9f583f)
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 static unsigned int preferred_states_mask;
68 
69 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
70 
71 static unsigned long auto_demotion_disable_flags;
72 
73 static enum {
74 	C1E_PROMOTION_PRESERVE,
75 	C1E_PROMOTION_ENABLE,
76 	C1E_PROMOTION_DISABLE
77 } c1e_promotion = C1E_PROMOTION_PRESERVE;
78 
79 struct idle_cpu {
80 	struct cpuidle_state *state_table;
81 
82 	/*
83 	 * Hardware C-state auto-demotion may not always be optimal.
84 	 * Indicate which enable bits to clear here.
85 	 */
86 	unsigned long auto_demotion_disable_flags;
87 	bool byt_auto_demotion_disable_flag;
88 	bool disable_promotion_to_c1e;
89 	bool use_acpi;
90 };
91 
92 static const struct idle_cpu *icpu __initdata;
93 static struct cpuidle_state *cpuidle_state_table __initdata;
94 
95 static unsigned int mwait_substates __initdata;
96 
97 /*
98  * Enable interrupts before entering the C-state. On some platforms and for
99  * some C-states, this may measurably decrease interrupt latency.
100  */
101 #define CPUIDLE_FLAG_IRQ_ENABLE		BIT(14)
102 
103 /*
104  * Enable this state by default even if the ACPI _CST does not list it.
105  */
106 #define CPUIDLE_FLAG_ALWAYS_ENABLE	BIT(15)
107 
108 /*
109  * MWAIT takes an 8-bit "hint" in EAX "suggesting"
110  * the C-state (top nibble) and sub-state (bottom nibble)
111  * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
112  *
113  * We store the hint at the top of our "flags" for each state.
114  */
115 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
116 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
117 
118 /**
119  * intel_idle - Ask the processor to enter the given idle state.
120  * @dev: cpuidle device of the target CPU.
121  * @drv: cpuidle driver (assumed to point to intel_idle_driver).
122  * @index: Target idle state index.
123  *
124  * Use the MWAIT instruction to notify the processor that the CPU represented by
125  * @dev is idle and it can try to enter the idle state corresponding to @index.
126  *
127  * If the local APIC timer is not known to be reliable in the target idle state,
128  * enable one-shot tick broadcasting for the target CPU before executing MWAIT.
129  *
130  * Must be called under local_irq_disable().
131  */
132 static __cpuidle int intel_idle(struct cpuidle_device *dev,
133 				struct cpuidle_driver *drv, int index)
134 {
135 	struct cpuidle_state *state = &drv->states[index];
136 	unsigned long eax = flg2MWAIT(state->flags);
137 	unsigned long ecx = 1; /* break on interrupt flag */
138 
139 	if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE)
140 		local_irq_enable();
141 
142 	mwait_idle_with_hints(eax, ecx);
143 
144 	return index;
145 }
146 
147 /**
148  * intel_idle_s2idle - Ask the processor to enter the given idle state.
149  * @dev: cpuidle device of the target CPU.
150  * @drv: cpuidle driver (assumed to point to intel_idle_driver).
151  * @index: Target idle state index.
152  *
153  * Use the MWAIT instruction to notify the processor that the CPU represented by
154  * @dev is idle and it can try to enter the idle state corresponding to @index.
155  *
156  * Invoked as a suspend-to-idle callback routine with frozen user space, frozen
157  * scheduler tick and suspended scheduler clock on the target CPU.
158  */
159 static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev,
160 				       struct cpuidle_driver *drv, int index)
161 {
162 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
163 	unsigned long ecx = 1; /* break on interrupt flag */
164 
165 	mwait_idle_with_hints(eax, ecx);
166 
167 	return 0;
168 }
169 
170 /*
171  * States are indexed by the cstate number,
172  * which is also the index into the MWAIT hint array.
173  * Thus C0 is a dummy.
174  */
175 static struct cpuidle_state nehalem_cstates[] __initdata = {
176 	{
177 		.name = "C1",
178 		.desc = "MWAIT 0x00",
179 		.flags = MWAIT2flg(0x00),
180 		.exit_latency = 3,
181 		.target_residency = 6,
182 		.enter = &intel_idle,
183 		.enter_s2idle = intel_idle_s2idle, },
184 	{
185 		.name = "C1E",
186 		.desc = "MWAIT 0x01",
187 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
188 		.exit_latency = 10,
189 		.target_residency = 20,
190 		.enter = &intel_idle,
191 		.enter_s2idle = intel_idle_s2idle, },
192 	{
193 		.name = "C3",
194 		.desc = "MWAIT 0x10",
195 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
196 		.exit_latency = 20,
197 		.target_residency = 80,
198 		.enter = &intel_idle,
199 		.enter_s2idle = intel_idle_s2idle, },
200 	{
201 		.name = "C6",
202 		.desc = "MWAIT 0x20",
203 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
204 		.exit_latency = 200,
205 		.target_residency = 800,
206 		.enter = &intel_idle,
207 		.enter_s2idle = intel_idle_s2idle, },
208 	{
209 		.enter = NULL }
210 };
211 
212 static struct cpuidle_state snb_cstates[] __initdata = {
213 	{
214 		.name = "C1",
215 		.desc = "MWAIT 0x00",
216 		.flags = MWAIT2flg(0x00),
217 		.exit_latency = 2,
218 		.target_residency = 2,
219 		.enter = &intel_idle,
220 		.enter_s2idle = intel_idle_s2idle, },
221 	{
222 		.name = "C1E",
223 		.desc = "MWAIT 0x01",
224 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
225 		.exit_latency = 10,
226 		.target_residency = 20,
227 		.enter = &intel_idle,
228 		.enter_s2idle = intel_idle_s2idle, },
229 	{
230 		.name = "C3",
231 		.desc = "MWAIT 0x10",
232 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
233 		.exit_latency = 80,
234 		.target_residency = 211,
235 		.enter = &intel_idle,
236 		.enter_s2idle = intel_idle_s2idle, },
237 	{
238 		.name = "C6",
239 		.desc = "MWAIT 0x20",
240 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
241 		.exit_latency = 104,
242 		.target_residency = 345,
243 		.enter = &intel_idle,
244 		.enter_s2idle = intel_idle_s2idle, },
245 	{
246 		.name = "C7",
247 		.desc = "MWAIT 0x30",
248 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
249 		.exit_latency = 109,
250 		.target_residency = 345,
251 		.enter = &intel_idle,
252 		.enter_s2idle = intel_idle_s2idle, },
253 	{
254 		.enter = NULL }
255 };
256 
257 static struct cpuidle_state byt_cstates[] __initdata = {
258 	{
259 		.name = "C1",
260 		.desc = "MWAIT 0x00",
261 		.flags = MWAIT2flg(0x00),
262 		.exit_latency = 1,
263 		.target_residency = 1,
264 		.enter = &intel_idle,
265 		.enter_s2idle = intel_idle_s2idle, },
266 	{
267 		.name = "C6N",
268 		.desc = "MWAIT 0x58",
269 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
270 		.exit_latency = 300,
271 		.target_residency = 275,
272 		.enter = &intel_idle,
273 		.enter_s2idle = intel_idle_s2idle, },
274 	{
275 		.name = "C6S",
276 		.desc = "MWAIT 0x52",
277 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
278 		.exit_latency = 500,
279 		.target_residency = 560,
280 		.enter = &intel_idle,
281 		.enter_s2idle = intel_idle_s2idle, },
282 	{
283 		.name = "C7",
284 		.desc = "MWAIT 0x60",
285 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
286 		.exit_latency = 1200,
287 		.target_residency = 4000,
288 		.enter = &intel_idle,
289 		.enter_s2idle = intel_idle_s2idle, },
290 	{
291 		.name = "C7S",
292 		.desc = "MWAIT 0x64",
293 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
294 		.exit_latency = 10000,
295 		.target_residency = 20000,
296 		.enter = &intel_idle,
297 		.enter_s2idle = intel_idle_s2idle, },
298 	{
299 		.enter = NULL }
300 };
301 
302 static struct cpuidle_state cht_cstates[] __initdata = {
303 	{
304 		.name = "C1",
305 		.desc = "MWAIT 0x00",
306 		.flags = MWAIT2flg(0x00),
307 		.exit_latency = 1,
308 		.target_residency = 1,
309 		.enter = &intel_idle,
310 		.enter_s2idle = intel_idle_s2idle, },
311 	{
312 		.name = "C6N",
313 		.desc = "MWAIT 0x58",
314 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
315 		.exit_latency = 80,
316 		.target_residency = 275,
317 		.enter = &intel_idle,
318 		.enter_s2idle = intel_idle_s2idle, },
319 	{
320 		.name = "C6S",
321 		.desc = "MWAIT 0x52",
322 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
323 		.exit_latency = 200,
324 		.target_residency = 560,
325 		.enter = &intel_idle,
326 		.enter_s2idle = intel_idle_s2idle, },
327 	{
328 		.name = "C7",
329 		.desc = "MWAIT 0x60",
330 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
331 		.exit_latency = 1200,
332 		.target_residency = 4000,
333 		.enter = &intel_idle,
334 		.enter_s2idle = intel_idle_s2idle, },
335 	{
336 		.name = "C7S",
337 		.desc = "MWAIT 0x64",
338 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
339 		.exit_latency = 10000,
340 		.target_residency = 20000,
341 		.enter = &intel_idle,
342 		.enter_s2idle = intel_idle_s2idle, },
343 	{
344 		.enter = NULL }
345 };
346 
347 static struct cpuidle_state ivb_cstates[] __initdata = {
348 	{
349 		.name = "C1",
350 		.desc = "MWAIT 0x00",
351 		.flags = MWAIT2flg(0x00),
352 		.exit_latency = 1,
353 		.target_residency = 1,
354 		.enter = &intel_idle,
355 		.enter_s2idle = intel_idle_s2idle, },
356 	{
357 		.name = "C1E",
358 		.desc = "MWAIT 0x01",
359 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
360 		.exit_latency = 10,
361 		.target_residency = 20,
362 		.enter = &intel_idle,
363 		.enter_s2idle = intel_idle_s2idle, },
364 	{
365 		.name = "C3",
366 		.desc = "MWAIT 0x10",
367 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
368 		.exit_latency = 59,
369 		.target_residency = 156,
370 		.enter = &intel_idle,
371 		.enter_s2idle = intel_idle_s2idle, },
372 	{
373 		.name = "C6",
374 		.desc = "MWAIT 0x20",
375 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
376 		.exit_latency = 80,
377 		.target_residency = 300,
378 		.enter = &intel_idle,
379 		.enter_s2idle = intel_idle_s2idle, },
380 	{
381 		.name = "C7",
382 		.desc = "MWAIT 0x30",
383 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
384 		.exit_latency = 87,
385 		.target_residency = 300,
386 		.enter = &intel_idle,
387 		.enter_s2idle = intel_idle_s2idle, },
388 	{
389 		.enter = NULL }
390 };
391 
392 static struct cpuidle_state ivt_cstates[] __initdata = {
393 	{
394 		.name = "C1",
395 		.desc = "MWAIT 0x00",
396 		.flags = MWAIT2flg(0x00),
397 		.exit_latency = 1,
398 		.target_residency = 1,
399 		.enter = &intel_idle,
400 		.enter_s2idle = intel_idle_s2idle, },
401 	{
402 		.name = "C1E",
403 		.desc = "MWAIT 0x01",
404 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
405 		.exit_latency = 10,
406 		.target_residency = 80,
407 		.enter = &intel_idle,
408 		.enter_s2idle = intel_idle_s2idle, },
409 	{
410 		.name = "C3",
411 		.desc = "MWAIT 0x10",
412 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
413 		.exit_latency = 59,
414 		.target_residency = 156,
415 		.enter = &intel_idle,
416 		.enter_s2idle = intel_idle_s2idle, },
417 	{
418 		.name = "C6",
419 		.desc = "MWAIT 0x20",
420 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
421 		.exit_latency = 82,
422 		.target_residency = 300,
423 		.enter = &intel_idle,
424 		.enter_s2idle = intel_idle_s2idle, },
425 	{
426 		.enter = NULL }
427 };
428 
429 static struct cpuidle_state ivt_cstates_4s[] __initdata = {
430 	{
431 		.name = "C1",
432 		.desc = "MWAIT 0x00",
433 		.flags = MWAIT2flg(0x00),
434 		.exit_latency = 1,
435 		.target_residency = 1,
436 		.enter = &intel_idle,
437 		.enter_s2idle = intel_idle_s2idle, },
438 	{
439 		.name = "C1E",
440 		.desc = "MWAIT 0x01",
441 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
442 		.exit_latency = 10,
443 		.target_residency = 250,
444 		.enter = &intel_idle,
445 		.enter_s2idle = intel_idle_s2idle, },
446 	{
447 		.name = "C3",
448 		.desc = "MWAIT 0x10",
449 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
450 		.exit_latency = 59,
451 		.target_residency = 300,
452 		.enter = &intel_idle,
453 		.enter_s2idle = intel_idle_s2idle, },
454 	{
455 		.name = "C6",
456 		.desc = "MWAIT 0x20",
457 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
458 		.exit_latency = 84,
459 		.target_residency = 400,
460 		.enter = &intel_idle,
461 		.enter_s2idle = intel_idle_s2idle, },
462 	{
463 		.enter = NULL }
464 };
465 
466 static struct cpuidle_state ivt_cstates_8s[] __initdata = {
467 	{
468 		.name = "C1",
469 		.desc = "MWAIT 0x00",
470 		.flags = MWAIT2flg(0x00),
471 		.exit_latency = 1,
472 		.target_residency = 1,
473 		.enter = &intel_idle,
474 		.enter_s2idle = intel_idle_s2idle, },
475 	{
476 		.name = "C1E",
477 		.desc = "MWAIT 0x01",
478 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
479 		.exit_latency = 10,
480 		.target_residency = 500,
481 		.enter = &intel_idle,
482 		.enter_s2idle = intel_idle_s2idle, },
483 	{
484 		.name = "C3",
485 		.desc = "MWAIT 0x10",
486 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
487 		.exit_latency = 59,
488 		.target_residency = 600,
489 		.enter = &intel_idle,
490 		.enter_s2idle = intel_idle_s2idle, },
491 	{
492 		.name = "C6",
493 		.desc = "MWAIT 0x20",
494 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
495 		.exit_latency = 88,
496 		.target_residency = 700,
497 		.enter = &intel_idle,
498 		.enter_s2idle = intel_idle_s2idle, },
499 	{
500 		.enter = NULL }
501 };
502 
503 static struct cpuidle_state hsw_cstates[] __initdata = {
504 	{
505 		.name = "C1",
506 		.desc = "MWAIT 0x00",
507 		.flags = MWAIT2flg(0x00),
508 		.exit_latency = 2,
509 		.target_residency = 2,
510 		.enter = &intel_idle,
511 		.enter_s2idle = intel_idle_s2idle, },
512 	{
513 		.name = "C1E",
514 		.desc = "MWAIT 0x01",
515 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
516 		.exit_latency = 10,
517 		.target_residency = 20,
518 		.enter = &intel_idle,
519 		.enter_s2idle = intel_idle_s2idle, },
520 	{
521 		.name = "C3",
522 		.desc = "MWAIT 0x10",
523 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
524 		.exit_latency = 33,
525 		.target_residency = 100,
526 		.enter = &intel_idle,
527 		.enter_s2idle = intel_idle_s2idle, },
528 	{
529 		.name = "C6",
530 		.desc = "MWAIT 0x20",
531 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
532 		.exit_latency = 133,
533 		.target_residency = 400,
534 		.enter = &intel_idle,
535 		.enter_s2idle = intel_idle_s2idle, },
536 	{
537 		.name = "C7s",
538 		.desc = "MWAIT 0x32",
539 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
540 		.exit_latency = 166,
541 		.target_residency = 500,
542 		.enter = &intel_idle,
543 		.enter_s2idle = intel_idle_s2idle, },
544 	{
545 		.name = "C8",
546 		.desc = "MWAIT 0x40",
547 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
548 		.exit_latency = 300,
549 		.target_residency = 900,
550 		.enter = &intel_idle,
551 		.enter_s2idle = intel_idle_s2idle, },
552 	{
553 		.name = "C9",
554 		.desc = "MWAIT 0x50",
555 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
556 		.exit_latency = 600,
557 		.target_residency = 1800,
558 		.enter = &intel_idle,
559 		.enter_s2idle = intel_idle_s2idle, },
560 	{
561 		.name = "C10",
562 		.desc = "MWAIT 0x60",
563 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
564 		.exit_latency = 2600,
565 		.target_residency = 7700,
566 		.enter = &intel_idle,
567 		.enter_s2idle = intel_idle_s2idle, },
568 	{
569 		.enter = NULL }
570 };
571 static struct cpuidle_state bdw_cstates[] __initdata = {
572 	{
573 		.name = "C1",
574 		.desc = "MWAIT 0x00",
575 		.flags = MWAIT2flg(0x00),
576 		.exit_latency = 2,
577 		.target_residency = 2,
578 		.enter = &intel_idle,
579 		.enter_s2idle = intel_idle_s2idle, },
580 	{
581 		.name = "C1E",
582 		.desc = "MWAIT 0x01",
583 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
584 		.exit_latency = 10,
585 		.target_residency = 20,
586 		.enter = &intel_idle,
587 		.enter_s2idle = intel_idle_s2idle, },
588 	{
589 		.name = "C3",
590 		.desc = "MWAIT 0x10",
591 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
592 		.exit_latency = 40,
593 		.target_residency = 100,
594 		.enter = &intel_idle,
595 		.enter_s2idle = intel_idle_s2idle, },
596 	{
597 		.name = "C6",
598 		.desc = "MWAIT 0x20",
599 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
600 		.exit_latency = 133,
601 		.target_residency = 400,
602 		.enter = &intel_idle,
603 		.enter_s2idle = intel_idle_s2idle, },
604 	{
605 		.name = "C7s",
606 		.desc = "MWAIT 0x32",
607 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
608 		.exit_latency = 166,
609 		.target_residency = 500,
610 		.enter = &intel_idle,
611 		.enter_s2idle = intel_idle_s2idle, },
612 	{
613 		.name = "C8",
614 		.desc = "MWAIT 0x40",
615 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
616 		.exit_latency = 300,
617 		.target_residency = 900,
618 		.enter = &intel_idle,
619 		.enter_s2idle = intel_idle_s2idle, },
620 	{
621 		.name = "C9",
622 		.desc = "MWAIT 0x50",
623 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
624 		.exit_latency = 600,
625 		.target_residency = 1800,
626 		.enter = &intel_idle,
627 		.enter_s2idle = intel_idle_s2idle, },
628 	{
629 		.name = "C10",
630 		.desc = "MWAIT 0x60",
631 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
632 		.exit_latency = 2600,
633 		.target_residency = 7700,
634 		.enter = &intel_idle,
635 		.enter_s2idle = intel_idle_s2idle, },
636 	{
637 		.enter = NULL }
638 };
639 
640 static struct cpuidle_state skl_cstates[] __initdata = {
641 	{
642 		.name = "C1",
643 		.desc = "MWAIT 0x00",
644 		.flags = MWAIT2flg(0x00),
645 		.exit_latency = 2,
646 		.target_residency = 2,
647 		.enter = &intel_idle,
648 		.enter_s2idle = intel_idle_s2idle, },
649 	{
650 		.name = "C1E",
651 		.desc = "MWAIT 0x01",
652 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
653 		.exit_latency = 10,
654 		.target_residency = 20,
655 		.enter = &intel_idle,
656 		.enter_s2idle = intel_idle_s2idle, },
657 	{
658 		.name = "C3",
659 		.desc = "MWAIT 0x10",
660 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
661 		.exit_latency = 70,
662 		.target_residency = 100,
663 		.enter = &intel_idle,
664 		.enter_s2idle = intel_idle_s2idle, },
665 	{
666 		.name = "C6",
667 		.desc = "MWAIT 0x20",
668 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
669 		.exit_latency = 85,
670 		.target_residency = 200,
671 		.enter = &intel_idle,
672 		.enter_s2idle = intel_idle_s2idle, },
673 	{
674 		.name = "C7s",
675 		.desc = "MWAIT 0x33",
676 		.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
677 		.exit_latency = 124,
678 		.target_residency = 800,
679 		.enter = &intel_idle,
680 		.enter_s2idle = intel_idle_s2idle, },
681 	{
682 		.name = "C8",
683 		.desc = "MWAIT 0x40",
684 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
685 		.exit_latency = 200,
686 		.target_residency = 800,
687 		.enter = &intel_idle,
688 		.enter_s2idle = intel_idle_s2idle, },
689 	{
690 		.name = "C9",
691 		.desc = "MWAIT 0x50",
692 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
693 		.exit_latency = 480,
694 		.target_residency = 5000,
695 		.enter = &intel_idle,
696 		.enter_s2idle = intel_idle_s2idle, },
697 	{
698 		.name = "C10",
699 		.desc = "MWAIT 0x60",
700 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
701 		.exit_latency = 890,
702 		.target_residency = 5000,
703 		.enter = &intel_idle,
704 		.enter_s2idle = intel_idle_s2idle, },
705 	{
706 		.enter = NULL }
707 };
708 
709 static struct cpuidle_state skx_cstates[] __initdata = {
710 	{
711 		.name = "C1",
712 		.desc = "MWAIT 0x00",
713 		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_IRQ_ENABLE,
714 		.exit_latency = 2,
715 		.target_residency = 2,
716 		.enter = &intel_idle,
717 		.enter_s2idle = intel_idle_s2idle, },
718 	{
719 		.name = "C1E",
720 		.desc = "MWAIT 0x01",
721 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
722 		.exit_latency = 10,
723 		.target_residency = 20,
724 		.enter = &intel_idle,
725 		.enter_s2idle = intel_idle_s2idle, },
726 	{
727 		.name = "C6",
728 		.desc = "MWAIT 0x20",
729 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
730 		.exit_latency = 133,
731 		.target_residency = 600,
732 		.enter = &intel_idle,
733 		.enter_s2idle = intel_idle_s2idle, },
734 	{
735 		.enter = NULL }
736 };
737 
738 static struct cpuidle_state icx_cstates[] __initdata = {
739 	{
740 		.name = "C1",
741 		.desc = "MWAIT 0x00",
742 		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_IRQ_ENABLE,
743 		.exit_latency = 1,
744 		.target_residency = 1,
745 		.enter = &intel_idle,
746 		.enter_s2idle = intel_idle_s2idle, },
747 	{
748 		.name = "C1E",
749 		.desc = "MWAIT 0x01",
750 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
751 		.exit_latency = 4,
752 		.target_residency = 4,
753 		.enter = &intel_idle,
754 		.enter_s2idle = intel_idle_s2idle, },
755 	{
756 		.name = "C6",
757 		.desc = "MWAIT 0x20",
758 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
759 		.exit_latency = 170,
760 		.target_residency = 600,
761 		.enter = &intel_idle,
762 		.enter_s2idle = intel_idle_s2idle, },
763 	{
764 		.enter = NULL }
765 };
766 
767 /*
768  * On Sapphire Rapids Xeon C1 has to be disabled if C1E is enabled, and vice
769  * versa. On SPR C1E is enabled only if "C1E promotion" bit is set in
770  * MSR_IA32_POWER_CTL. But in this case there effectively no C1, because C1
771  * requests are promoted to C1E. If the "C1E promotion" bit is cleared, then
772  * both C1 and C1E requests end up with C1, so there is effectively no C1E.
773  *
774  * By default we enable C1 and disable C1E by marking it with
775  * 'CPUIDLE_FLAG_UNUSABLE'.
776  */
777 static struct cpuidle_state spr_cstates[] __initdata = {
778 	{
779 		.name = "C1",
780 		.desc = "MWAIT 0x00",
781 		.flags = MWAIT2flg(0x00),
782 		.exit_latency = 1,
783 		.target_residency = 1,
784 		.enter = &intel_idle,
785 		.enter_s2idle = intel_idle_s2idle, },
786 	{
787 		.name = "C1E",
788 		.desc = "MWAIT 0x01",
789 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE |
790 					   CPUIDLE_FLAG_UNUSABLE,
791 		.exit_latency = 2,
792 		.target_residency = 4,
793 		.enter = &intel_idle,
794 		.enter_s2idle = intel_idle_s2idle, },
795 	{
796 		.name = "C6",
797 		.desc = "MWAIT 0x20",
798 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
799 		.exit_latency = 290,
800 		.target_residency = 800,
801 		.enter = &intel_idle,
802 		.enter_s2idle = intel_idle_s2idle, },
803 	{
804 		.enter = NULL }
805 };
806 
807 static struct cpuidle_state atom_cstates[] __initdata = {
808 	{
809 		.name = "C1E",
810 		.desc = "MWAIT 0x00",
811 		.flags = MWAIT2flg(0x00),
812 		.exit_latency = 10,
813 		.target_residency = 20,
814 		.enter = &intel_idle,
815 		.enter_s2idle = intel_idle_s2idle, },
816 	{
817 		.name = "C2",
818 		.desc = "MWAIT 0x10",
819 		.flags = MWAIT2flg(0x10),
820 		.exit_latency = 20,
821 		.target_residency = 80,
822 		.enter = &intel_idle,
823 		.enter_s2idle = intel_idle_s2idle, },
824 	{
825 		.name = "C4",
826 		.desc = "MWAIT 0x30",
827 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
828 		.exit_latency = 100,
829 		.target_residency = 400,
830 		.enter = &intel_idle,
831 		.enter_s2idle = intel_idle_s2idle, },
832 	{
833 		.name = "C6",
834 		.desc = "MWAIT 0x52",
835 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
836 		.exit_latency = 140,
837 		.target_residency = 560,
838 		.enter = &intel_idle,
839 		.enter_s2idle = intel_idle_s2idle, },
840 	{
841 		.enter = NULL }
842 };
843 static struct cpuidle_state tangier_cstates[] __initdata = {
844 	{
845 		.name = "C1",
846 		.desc = "MWAIT 0x00",
847 		.flags = MWAIT2flg(0x00),
848 		.exit_latency = 1,
849 		.target_residency = 4,
850 		.enter = &intel_idle,
851 		.enter_s2idle = intel_idle_s2idle, },
852 	{
853 		.name = "C4",
854 		.desc = "MWAIT 0x30",
855 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
856 		.exit_latency = 100,
857 		.target_residency = 400,
858 		.enter = &intel_idle,
859 		.enter_s2idle = intel_idle_s2idle, },
860 	{
861 		.name = "C6",
862 		.desc = "MWAIT 0x52",
863 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
864 		.exit_latency = 140,
865 		.target_residency = 560,
866 		.enter = &intel_idle,
867 		.enter_s2idle = intel_idle_s2idle, },
868 	{
869 		.name = "C7",
870 		.desc = "MWAIT 0x60",
871 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
872 		.exit_latency = 1200,
873 		.target_residency = 4000,
874 		.enter = &intel_idle,
875 		.enter_s2idle = intel_idle_s2idle, },
876 	{
877 		.name = "C9",
878 		.desc = "MWAIT 0x64",
879 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
880 		.exit_latency = 10000,
881 		.target_residency = 20000,
882 		.enter = &intel_idle,
883 		.enter_s2idle = intel_idle_s2idle, },
884 	{
885 		.enter = NULL }
886 };
887 static struct cpuidle_state avn_cstates[] __initdata = {
888 	{
889 		.name = "C1",
890 		.desc = "MWAIT 0x00",
891 		.flags = MWAIT2flg(0x00),
892 		.exit_latency = 2,
893 		.target_residency = 2,
894 		.enter = &intel_idle,
895 		.enter_s2idle = intel_idle_s2idle, },
896 	{
897 		.name = "C6",
898 		.desc = "MWAIT 0x51",
899 		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
900 		.exit_latency = 15,
901 		.target_residency = 45,
902 		.enter = &intel_idle,
903 		.enter_s2idle = intel_idle_s2idle, },
904 	{
905 		.enter = NULL }
906 };
907 static struct cpuidle_state knl_cstates[] __initdata = {
908 	{
909 		.name = "C1",
910 		.desc = "MWAIT 0x00",
911 		.flags = MWAIT2flg(0x00),
912 		.exit_latency = 1,
913 		.target_residency = 2,
914 		.enter = &intel_idle,
915 		.enter_s2idle = intel_idle_s2idle },
916 	{
917 		.name = "C6",
918 		.desc = "MWAIT 0x10",
919 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
920 		.exit_latency = 120,
921 		.target_residency = 500,
922 		.enter = &intel_idle,
923 		.enter_s2idle = intel_idle_s2idle },
924 	{
925 		.enter = NULL }
926 };
927 
928 static struct cpuidle_state bxt_cstates[] __initdata = {
929 	{
930 		.name = "C1",
931 		.desc = "MWAIT 0x00",
932 		.flags = MWAIT2flg(0x00),
933 		.exit_latency = 2,
934 		.target_residency = 2,
935 		.enter = &intel_idle,
936 		.enter_s2idle = intel_idle_s2idle, },
937 	{
938 		.name = "C1E",
939 		.desc = "MWAIT 0x01",
940 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
941 		.exit_latency = 10,
942 		.target_residency = 20,
943 		.enter = &intel_idle,
944 		.enter_s2idle = intel_idle_s2idle, },
945 	{
946 		.name = "C6",
947 		.desc = "MWAIT 0x20",
948 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
949 		.exit_latency = 133,
950 		.target_residency = 133,
951 		.enter = &intel_idle,
952 		.enter_s2idle = intel_idle_s2idle, },
953 	{
954 		.name = "C7s",
955 		.desc = "MWAIT 0x31",
956 		.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
957 		.exit_latency = 155,
958 		.target_residency = 155,
959 		.enter = &intel_idle,
960 		.enter_s2idle = intel_idle_s2idle, },
961 	{
962 		.name = "C8",
963 		.desc = "MWAIT 0x40",
964 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
965 		.exit_latency = 1000,
966 		.target_residency = 1000,
967 		.enter = &intel_idle,
968 		.enter_s2idle = intel_idle_s2idle, },
969 	{
970 		.name = "C9",
971 		.desc = "MWAIT 0x50",
972 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
973 		.exit_latency = 2000,
974 		.target_residency = 2000,
975 		.enter = &intel_idle,
976 		.enter_s2idle = intel_idle_s2idle, },
977 	{
978 		.name = "C10",
979 		.desc = "MWAIT 0x60",
980 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
981 		.exit_latency = 10000,
982 		.target_residency = 10000,
983 		.enter = &intel_idle,
984 		.enter_s2idle = intel_idle_s2idle, },
985 	{
986 		.enter = NULL }
987 };
988 
989 static struct cpuidle_state dnv_cstates[] __initdata = {
990 	{
991 		.name = "C1",
992 		.desc = "MWAIT 0x00",
993 		.flags = MWAIT2flg(0x00),
994 		.exit_latency = 2,
995 		.target_residency = 2,
996 		.enter = &intel_idle,
997 		.enter_s2idle = intel_idle_s2idle, },
998 	{
999 		.name = "C1E",
1000 		.desc = "MWAIT 0x01",
1001 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
1002 		.exit_latency = 10,
1003 		.target_residency = 20,
1004 		.enter = &intel_idle,
1005 		.enter_s2idle = intel_idle_s2idle, },
1006 	{
1007 		.name = "C6",
1008 		.desc = "MWAIT 0x20",
1009 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
1010 		.exit_latency = 50,
1011 		.target_residency = 500,
1012 		.enter = &intel_idle,
1013 		.enter_s2idle = intel_idle_s2idle, },
1014 	{
1015 		.enter = NULL }
1016 };
1017 
1018 /*
1019  * Note, depending on HW and FW revision, SnowRidge SoC may or may not support
1020  * C6, and this is indicated in the CPUID mwait leaf.
1021  */
1022 static struct cpuidle_state snr_cstates[] __initdata = {
1023 	{
1024 		.name = "C1",
1025 		.desc = "MWAIT 0x00",
1026 		.flags = MWAIT2flg(0x00),
1027 		.exit_latency = 2,
1028 		.target_residency = 2,
1029 		.enter = &intel_idle,
1030 		.enter_s2idle = intel_idle_s2idle, },
1031 	{
1032 		.name = "C1E",
1033 		.desc = "MWAIT 0x01",
1034 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
1035 		.exit_latency = 15,
1036 		.target_residency = 25,
1037 		.enter = &intel_idle,
1038 		.enter_s2idle = intel_idle_s2idle, },
1039 	{
1040 		.name = "C6",
1041 		.desc = "MWAIT 0x20",
1042 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
1043 		.exit_latency = 130,
1044 		.target_residency = 500,
1045 		.enter = &intel_idle,
1046 		.enter_s2idle = intel_idle_s2idle, },
1047 	{
1048 		.enter = NULL }
1049 };
1050 
1051 static const struct idle_cpu idle_cpu_nehalem __initconst = {
1052 	.state_table = nehalem_cstates,
1053 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
1054 	.disable_promotion_to_c1e = true,
1055 };
1056 
1057 static const struct idle_cpu idle_cpu_nhx __initconst = {
1058 	.state_table = nehalem_cstates,
1059 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
1060 	.disable_promotion_to_c1e = true,
1061 	.use_acpi = true,
1062 };
1063 
1064 static const struct idle_cpu idle_cpu_atom __initconst = {
1065 	.state_table = atom_cstates,
1066 };
1067 
1068 static const struct idle_cpu idle_cpu_tangier __initconst = {
1069 	.state_table = tangier_cstates,
1070 };
1071 
1072 static const struct idle_cpu idle_cpu_lincroft __initconst = {
1073 	.state_table = atom_cstates,
1074 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
1075 };
1076 
1077 static const struct idle_cpu idle_cpu_snb __initconst = {
1078 	.state_table = snb_cstates,
1079 	.disable_promotion_to_c1e = true,
1080 };
1081 
1082 static const struct idle_cpu idle_cpu_snx __initconst = {
1083 	.state_table = snb_cstates,
1084 	.disable_promotion_to_c1e = true,
1085 	.use_acpi = true,
1086 };
1087 
1088 static const struct idle_cpu idle_cpu_byt __initconst = {
1089 	.state_table = byt_cstates,
1090 	.disable_promotion_to_c1e = true,
1091 	.byt_auto_demotion_disable_flag = true,
1092 };
1093 
1094 static const struct idle_cpu idle_cpu_cht __initconst = {
1095 	.state_table = cht_cstates,
1096 	.disable_promotion_to_c1e = true,
1097 	.byt_auto_demotion_disable_flag = true,
1098 };
1099 
1100 static const struct idle_cpu idle_cpu_ivb __initconst = {
1101 	.state_table = ivb_cstates,
1102 	.disable_promotion_to_c1e = true,
1103 };
1104 
1105 static const struct idle_cpu idle_cpu_ivt __initconst = {
1106 	.state_table = ivt_cstates,
1107 	.disable_promotion_to_c1e = true,
1108 	.use_acpi = true,
1109 };
1110 
1111 static const struct idle_cpu idle_cpu_hsw __initconst = {
1112 	.state_table = hsw_cstates,
1113 	.disable_promotion_to_c1e = true,
1114 };
1115 
1116 static const struct idle_cpu idle_cpu_hsx __initconst = {
1117 	.state_table = hsw_cstates,
1118 	.disable_promotion_to_c1e = true,
1119 	.use_acpi = true,
1120 };
1121 
1122 static const struct idle_cpu idle_cpu_bdw __initconst = {
1123 	.state_table = bdw_cstates,
1124 	.disable_promotion_to_c1e = true,
1125 };
1126 
1127 static const struct idle_cpu idle_cpu_bdx __initconst = {
1128 	.state_table = bdw_cstates,
1129 	.disable_promotion_to_c1e = true,
1130 	.use_acpi = true,
1131 };
1132 
1133 static const struct idle_cpu idle_cpu_skl __initconst = {
1134 	.state_table = skl_cstates,
1135 	.disable_promotion_to_c1e = true,
1136 };
1137 
1138 static const struct idle_cpu idle_cpu_skx __initconst = {
1139 	.state_table = skx_cstates,
1140 	.disable_promotion_to_c1e = true,
1141 	.use_acpi = true,
1142 };
1143 
1144 static const struct idle_cpu idle_cpu_icx __initconst = {
1145 	.state_table = icx_cstates,
1146 	.disable_promotion_to_c1e = true,
1147 	.use_acpi = true,
1148 };
1149 
1150 static const struct idle_cpu idle_cpu_spr __initconst = {
1151 	.state_table = spr_cstates,
1152 	.disable_promotion_to_c1e = true,
1153 	.use_acpi = true,
1154 };
1155 
1156 static const struct idle_cpu idle_cpu_avn __initconst = {
1157 	.state_table = avn_cstates,
1158 	.disable_promotion_to_c1e = true,
1159 	.use_acpi = true,
1160 };
1161 
1162 static const struct idle_cpu idle_cpu_knl __initconst = {
1163 	.state_table = knl_cstates,
1164 	.use_acpi = true,
1165 };
1166 
1167 static const struct idle_cpu idle_cpu_bxt __initconst = {
1168 	.state_table = bxt_cstates,
1169 	.disable_promotion_to_c1e = true,
1170 };
1171 
1172 static const struct idle_cpu idle_cpu_dnv __initconst = {
1173 	.state_table = dnv_cstates,
1174 	.disable_promotion_to_c1e = true,
1175 	.use_acpi = true,
1176 };
1177 
1178 static const struct idle_cpu idle_cpu_snr __initconst = {
1179 	.state_table = snr_cstates,
1180 	.disable_promotion_to_c1e = true,
1181 	.use_acpi = true,
1182 };
1183 
1184 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1185 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EP,		&idle_cpu_nhx),
1186 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM,		&idle_cpu_nehalem),
1187 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_G,		&idle_cpu_nehalem),
1188 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE,		&idle_cpu_nehalem),
1189 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EP,		&idle_cpu_nhx),
1190 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EX,		&idle_cpu_nhx),
1191 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL,	&idle_cpu_atom),
1192 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL_MID,	&idle_cpu_lincroft),
1193 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EX,		&idle_cpu_nhx),
1194 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE,		&idle_cpu_snb),
1195 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE_X,	&idle_cpu_snx),
1196 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SALTWELL,	&idle_cpu_atom),
1197 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	&idle_cpu_byt),
1198 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID,	&idle_cpu_tangier),
1199 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	&idle_cpu_cht),
1200 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE,		&idle_cpu_ivb),
1201 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE_X,		&idle_cpu_ivt),
1202 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL,		&idle_cpu_hsw),
1203 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X,		&idle_cpu_hsx),
1204 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_L,		&idle_cpu_hsw),
1205 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_G,		&idle_cpu_hsw),
1206 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_D,	&idle_cpu_avn),
1207 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL,		&idle_cpu_bdw),
1208 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_G,		&idle_cpu_bdw),
1209 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X,		&idle_cpu_bdx),
1210 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_D,		&idle_cpu_bdx),
1211 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		&idle_cpu_skl),
1212 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		&idle_cpu_skl),
1213 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		&idle_cpu_skl),
1214 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		&idle_cpu_skl),
1215 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X,		&idle_cpu_skx),
1216 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		&idle_cpu_icx),
1217 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D,		&idle_cpu_icx),
1218 	X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X,	&idle_cpu_spr),
1219 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL,	&idle_cpu_knl),
1220 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM,	&idle_cpu_knl),
1221 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	&idle_cpu_bxt),
1222 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_PLUS,	&idle_cpu_bxt),
1223 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D,	&idle_cpu_dnv),
1224 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	&idle_cpu_snr),
1225 	{}
1226 };
1227 
1228 static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
1229 	X86_MATCH_VENDOR_FAM_FEATURE(INTEL, 6, X86_FEATURE_MWAIT, NULL),
1230 	{}
1231 };
1232 
1233 static bool __init intel_idle_max_cstate_reached(int cstate)
1234 {
1235 	if (cstate + 1 > max_cstate) {
1236 		pr_info("max_cstate %d reached\n", max_cstate);
1237 		return true;
1238 	}
1239 	return false;
1240 }
1241 
1242 static bool __init intel_idle_state_needs_timer_stop(struct cpuidle_state *state)
1243 {
1244 	unsigned long eax = flg2MWAIT(state->flags);
1245 
1246 	if (boot_cpu_has(X86_FEATURE_ARAT))
1247 		return false;
1248 
1249 	/*
1250 	 * Switch over to one-shot tick broadcast if the target C-state
1251 	 * is deeper than C1.
1252 	 */
1253 	return !!((eax >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK);
1254 }
1255 
1256 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
1257 #include <acpi/processor.h>
1258 
1259 static bool no_acpi __read_mostly;
1260 module_param(no_acpi, bool, 0444);
1261 MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list");
1262 
1263 static bool force_use_acpi __read_mostly; /* No effect if no_acpi is set. */
1264 module_param_named(use_acpi, force_use_acpi, bool, 0444);
1265 MODULE_PARM_DESC(use_acpi, "Use ACPI _CST for building the idle states list");
1266 
1267 static struct acpi_processor_power acpi_state_table __initdata;
1268 
1269 /**
1270  * intel_idle_cst_usable - Check if the _CST information can be used.
1271  *
1272  * Check if all of the C-states listed by _CST in the max_cstate range are
1273  * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
1274  */
1275 static bool __init intel_idle_cst_usable(void)
1276 {
1277 	int cstate, limit;
1278 
1279 	limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
1280 		      acpi_state_table.count);
1281 
1282 	for (cstate = 1; cstate < limit; cstate++) {
1283 		struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
1284 
1285 		if (cx->entry_method != ACPI_CSTATE_FFH)
1286 			return false;
1287 	}
1288 
1289 	return true;
1290 }
1291 
1292 static bool __init intel_idle_acpi_cst_extract(void)
1293 {
1294 	unsigned int cpu;
1295 
1296 	if (no_acpi) {
1297 		pr_debug("Not allowed to use ACPI _CST\n");
1298 		return false;
1299 	}
1300 
1301 	for_each_possible_cpu(cpu) {
1302 		struct acpi_processor *pr = per_cpu(processors, cpu);
1303 
1304 		if (!pr)
1305 			continue;
1306 
1307 		if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
1308 			continue;
1309 
1310 		acpi_state_table.count++;
1311 
1312 		if (!intel_idle_cst_usable())
1313 			continue;
1314 
1315 		if (!acpi_processor_claim_cst_control())
1316 			break;
1317 
1318 		return true;
1319 	}
1320 
1321 	acpi_state_table.count = 0;
1322 	pr_debug("ACPI _CST not found or not usable\n");
1323 	return false;
1324 }
1325 
1326 static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
1327 {
1328 	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1329 
1330 	/*
1331 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1332 	 * the interesting states are ACPI_CSTATE_FFH.
1333 	 */
1334 	for (cstate = 1; cstate < limit; cstate++) {
1335 		struct acpi_processor_cx *cx;
1336 		struct cpuidle_state *state;
1337 
1338 		if (intel_idle_max_cstate_reached(cstate - 1))
1339 			break;
1340 
1341 		cx = &acpi_state_table.states[cstate];
1342 
1343 		state = &drv->states[drv->state_count++];
1344 
1345 		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
1346 		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1347 		state->exit_latency = cx->latency;
1348 		/*
1349 		 * For C1-type C-states use the same number for both the exit
1350 		 * latency and target residency, because that is the case for
1351 		 * C1 in the majority of the static C-states tables above.
1352 		 * For the other types of C-states, however, set the target
1353 		 * residency to 3 times the exit latency which should lead to
1354 		 * a reasonable balance between energy-efficiency and
1355 		 * performance in the majority of interesting cases.
1356 		 */
1357 		state->target_residency = cx->latency;
1358 		if (cx->type > ACPI_STATE_C1)
1359 			state->target_residency *= 3;
1360 
1361 		state->flags = MWAIT2flg(cx->address);
1362 		if (cx->type > ACPI_STATE_C2)
1363 			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
1364 
1365 		if (disabled_states_mask & BIT(cstate))
1366 			state->flags |= CPUIDLE_FLAG_OFF;
1367 
1368 		if (intel_idle_state_needs_timer_stop(state))
1369 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1370 
1371 		state->enter = intel_idle;
1372 		state->enter_s2idle = intel_idle_s2idle;
1373 	}
1374 }
1375 
1376 static bool __init intel_idle_off_by_default(u32 mwait_hint)
1377 {
1378 	int cstate, limit;
1379 
1380 	/*
1381 	 * If there are no _CST C-states, do not disable any C-states by
1382 	 * default.
1383 	 */
1384 	if (!acpi_state_table.count)
1385 		return false;
1386 
1387 	limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1388 	/*
1389 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1390 	 * the interesting states are ACPI_CSTATE_FFH.
1391 	 */
1392 	for (cstate = 1; cstate < limit; cstate++) {
1393 		if (acpi_state_table.states[cstate].address == mwait_hint)
1394 			return false;
1395 	}
1396 	return true;
1397 }
1398 #else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1399 #define force_use_acpi	(false)
1400 
1401 static inline bool intel_idle_acpi_cst_extract(void) { return false; }
1402 static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
1403 static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
1404 #endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1405 
1406 /**
1407  * ivt_idle_state_table_update - Tune the idle states table for Ivy Town.
1408  *
1409  * Tune IVT multi-socket targets.
1410  * Assumption: num_sockets == (max_package_num + 1).
1411  */
1412 static void __init ivt_idle_state_table_update(void)
1413 {
1414 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1415 	int cpu, package_num, num_sockets = 1;
1416 
1417 	for_each_online_cpu(cpu) {
1418 		package_num = topology_physical_package_id(cpu);
1419 		if (package_num + 1 > num_sockets) {
1420 			num_sockets = package_num + 1;
1421 
1422 			if (num_sockets > 4) {
1423 				cpuidle_state_table = ivt_cstates_8s;
1424 				return;
1425 			}
1426 		}
1427 	}
1428 
1429 	if (num_sockets > 2)
1430 		cpuidle_state_table = ivt_cstates_4s;
1431 
1432 	/* else, 1 and 2 socket systems use default ivt_cstates */
1433 }
1434 
1435 /**
1436  * irtl_2_usec - IRTL to microseconds conversion.
1437  * @irtl: IRTL MSR value.
1438  *
1439  * Translate the IRTL (Interrupt Response Time Limit) MSR value to microseconds.
1440  */
1441 static unsigned long long __init irtl_2_usec(unsigned long long irtl)
1442 {
1443 	static const unsigned int irtl_ns_units[] __initconst = {
1444 		1, 32, 1024, 32768, 1048576, 33554432, 0, 0
1445 	};
1446 	unsigned long long ns;
1447 
1448 	if (!irtl)
1449 		return 0;
1450 
1451 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1452 
1453 	return div_u64((irtl & 0x3FF) * ns, NSEC_PER_USEC);
1454 }
1455 
1456 /**
1457  * bxt_idle_state_table_update - Fix up the Broxton idle states table.
1458  *
1459  * On BXT, trust the IRTL (Interrupt Response Time Limit) MSR to show the
1460  * definitive maximum latency and use the same value for target_residency.
1461  */
1462 static void __init bxt_idle_state_table_update(void)
1463 {
1464 	unsigned long long msr;
1465 	unsigned int usec;
1466 
1467 	rdmsrl(MSR_PKGC6_IRTL, msr);
1468 	usec = irtl_2_usec(msr);
1469 	if (usec) {
1470 		bxt_cstates[2].exit_latency = usec;
1471 		bxt_cstates[2].target_residency = usec;
1472 	}
1473 
1474 	rdmsrl(MSR_PKGC7_IRTL, msr);
1475 	usec = irtl_2_usec(msr);
1476 	if (usec) {
1477 		bxt_cstates[3].exit_latency = usec;
1478 		bxt_cstates[3].target_residency = usec;
1479 	}
1480 
1481 	rdmsrl(MSR_PKGC8_IRTL, msr);
1482 	usec = irtl_2_usec(msr);
1483 	if (usec) {
1484 		bxt_cstates[4].exit_latency = usec;
1485 		bxt_cstates[4].target_residency = usec;
1486 	}
1487 
1488 	rdmsrl(MSR_PKGC9_IRTL, msr);
1489 	usec = irtl_2_usec(msr);
1490 	if (usec) {
1491 		bxt_cstates[5].exit_latency = usec;
1492 		bxt_cstates[5].target_residency = usec;
1493 	}
1494 
1495 	rdmsrl(MSR_PKGC10_IRTL, msr);
1496 	usec = irtl_2_usec(msr);
1497 	if (usec) {
1498 		bxt_cstates[6].exit_latency = usec;
1499 		bxt_cstates[6].target_residency = usec;
1500 	}
1501 
1502 }
1503 
1504 /**
1505  * sklh_idle_state_table_update - Fix up the Sky Lake idle states table.
1506  *
1507  * On SKL-H (model 0x5e) skip C8 and C9 if C10 is enabled and SGX disabled.
1508  */
1509 static void __init sklh_idle_state_table_update(void)
1510 {
1511 	unsigned long long msr;
1512 	unsigned int eax, ebx, ecx, edx;
1513 
1514 
1515 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1516 	if (max_cstate <= 7)
1517 		return;
1518 
1519 	/* if PC10 not present in CPUID.MWAIT.EDX */
1520 	if ((mwait_substates & (0xF << 28)) == 0)
1521 		return;
1522 
1523 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1524 
1525 	/* PC10 is not enabled in PKG C-state limit */
1526 	if ((msr & 0xF) != 8)
1527 		return;
1528 
1529 	ecx = 0;
1530 	cpuid(7, &eax, &ebx, &ecx, &edx);
1531 
1532 	/* if SGX is present */
1533 	if (ebx & (1 << 2)) {
1534 
1535 		rdmsrl(MSR_IA32_FEAT_CTL, msr);
1536 
1537 		/* if SGX is enabled */
1538 		if (msr & (1 << 18))
1539 			return;
1540 	}
1541 
1542 	skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C8-SKL */
1543 	skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C9-SKL */
1544 }
1545 
1546 /**
1547  * skx_idle_state_table_update - Adjust the Sky Lake/Cascade Lake
1548  * idle states table.
1549  */
1550 static void __init skx_idle_state_table_update(void)
1551 {
1552 	unsigned long long msr;
1553 
1554 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1555 
1556 	/*
1557 	 * 000b: C0/C1 (no package C-state support)
1558 	 * 001b: C2
1559 	 * 010b: C6 (non-retention)
1560 	 * 011b: C6 (retention)
1561 	 * 111b: No Package C state limits.
1562 	 */
1563 	if ((msr & 0x7) < 2) {
1564 		/*
1565 		 * Uses the CC6 + PC0 latency and 3 times of
1566 		 * latency for target_residency if the PC6
1567 		 * is disabled in BIOS. This is consistent
1568 		 * with how intel_idle driver uses _CST
1569 		 * to set the target_residency.
1570 		 */
1571 		skx_cstates[2].exit_latency = 92;
1572 		skx_cstates[2].target_residency = 276;
1573 	}
1574 }
1575 
1576 /**
1577  * spr_idle_state_table_update - Adjust Sapphire Rapids idle states table.
1578  */
1579 static void __init spr_idle_state_table_update(void)
1580 {
1581 	unsigned long long msr;
1582 
1583 	/* Check if user prefers C1E over C1. */
1584 	if ((preferred_states_mask & BIT(2)) &&
1585 	    !(preferred_states_mask & BIT(1))) {
1586 		/* Disable C1 and enable C1E. */
1587 		spr_cstates[0].flags |= CPUIDLE_FLAG_UNUSABLE;
1588 		spr_cstates[1].flags &= ~CPUIDLE_FLAG_UNUSABLE;
1589 
1590 		/* Enable C1E using the "C1E promotion" bit. */
1591 		c1e_promotion = C1E_PROMOTION_ENABLE;
1592 	}
1593 
1594 	/*
1595 	 * By default, the C6 state assumes the worst-case scenario of package
1596 	 * C6. However, if PC6 is disabled, we update the numbers to match
1597 	 * core C6.
1598 	 */
1599 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1600 
1601 	/* Limit value 2 and above allow for PC6. */
1602 	if ((msr & 0x7) < 2) {
1603 		spr_cstates[2].exit_latency = 190;
1604 		spr_cstates[2].target_residency = 600;
1605 	}
1606 }
1607 
1608 static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
1609 {
1610 	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
1611 	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
1612 					MWAIT_SUBSTATE_MASK;
1613 
1614 	/* Ignore the C-state if there are NO sub-states in CPUID for it. */
1615 	if (num_substates == 0)
1616 		return false;
1617 
1618 	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1619 		mark_tsc_unstable("TSC halts in idle states deeper than C2");
1620 
1621 	return true;
1622 }
1623 
1624 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
1625 {
1626 	int cstate;
1627 
1628 	switch (boot_cpu_data.x86_model) {
1629 	case INTEL_FAM6_IVYBRIDGE_X:
1630 		ivt_idle_state_table_update();
1631 		break;
1632 	case INTEL_FAM6_ATOM_GOLDMONT:
1633 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1634 		bxt_idle_state_table_update();
1635 		break;
1636 	case INTEL_FAM6_SKYLAKE:
1637 		sklh_idle_state_table_update();
1638 		break;
1639 	case INTEL_FAM6_SKYLAKE_X:
1640 		skx_idle_state_table_update();
1641 		break;
1642 	case INTEL_FAM6_SAPPHIRERAPIDS_X:
1643 		spr_idle_state_table_update();
1644 		break;
1645 	}
1646 
1647 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1648 		unsigned int mwait_hint;
1649 
1650 		if (intel_idle_max_cstate_reached(cstate))
1651 			break;
1652 
1653 		if (!cpuidle_state_table[cstate].enter &&
1654 		    !cpuidle_state_table[cstate].enter_s2idle)
1655 			break;
1656 
1657 		/* If marked as unusable, skip this state. */
1658 		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
1659 			pr_debug("state %s is disabled\n",
1660 				 cpuidle_state_table[cstate].name);
1661 			continue;
1662 		}
1663 
1664 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1665 		if (!intel_idle_verify_cstate(mwait_hint))
1666 			continue;
1667 
1668 		/* Structure copy. */
1669 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
1670 
1671 		if ((disabled_states_mask & BIT(drv->state_count)) ||
1672 		    ((icpu->use_acpi || force_use_acpi) &&
1673 		     intel_idle_off_by_default(mwait_hint) &&
1674 		     !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE)))
1675 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF;
1676 
1677 		if (intel_idle_state_needs_timer_stop(&drv->states[drv->state_count]))
1678 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_TIMER_STOP;
1679 
1680 		drv->state_count++;
1681 	}
1682 
1683 	if (icpu->byt_auto_demotion_disable_flag) {
1684 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1685 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1686 	}
1687 }
1688 
1689 /**
1690  * intel_idle_cpuidle_driver_init - Create the list of available idle states.
1691  * @drv: cpuidle driver structure to initialize.
1692  */
1693 static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
1694 {
1695 	cpuidle_poll_state_init(drv);
1696 
1697 	if (disabled_states_mask & BIT(0))
1698 		drv->states[0].flags |= CPUIDLE_FLAG_OFF;
1699 
1700 	drv->state_count = 1;
1701 
1702 	if (icpu)
1703 		intel_idle_init_cstates_icpu(drv);
1704 	else
1705 		intel_idle_init_cstates_acpi(drv);
1706 }
1707 
1708 static void auto_demotion_disable(void)
1709 {
1710 	unsigned long long msr_bits;
1711 
1712 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1713 	msr_bits &= ~auto_demotion_disable_flags;
1714 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1715 }
1716 
1717 static void c1e_promotion_enable(void)
1718 {
1719 	unsigned long long msr_bits;
1720 
1721 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
1722 	msr_bits |= 0x2;
1723 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
1724 }
1725 
1726 static void c1e_promotion_disable(void)
1727 {
1728 	unsigned long long msr_bits;
1729 
1730 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
1731 	msr_bits &= ~0x2;
1732 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
1733 }
1734 
1735 /**
1736  * intel_idle_cpu_init - Register the target CPU with the cpuidle core.
1737  * @cpu: CPU to initialize.
1738  *
1739  * Register a cpuidle device object for @cpu and update its MSRs in accordance
1740  * with the processor model flags.
1741  */
1742 static int intel_idle_cpu_init(unsigned int cpu)
1743 {
1744 	struct cpuidle_device *dev;
1745 
1746 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1747 	dev->cpu = cpu;
1748 
1749 	if (cpuidle_register_device(dev)) {
1750 		pr_debug("cpuidle_register_device %d failed!\n", cpu);
1751 		return -EIO;
1752 	}
1753 
1754 	if (auto_demotion_disable_flags)
1755 		auto_demotion_disable();
1756 
1757 	if (c1e_promotion == C1E_PROMOTION_ENABLE)
1758 		c1e_promotion_enable();
1759 	else if (c1e_promotion == C1E_PROMOTION_DISABLE)
1760 		c1e_promotion_disable();
1761 
1762 	return 0;
1763 }
1764 
1765 static int intel_idle_cpu_online(unsigned int cpu)
1766 {
1767 	struct cpuidle_device *dev;
1768 
1769 	if (!boot_cpu_has(X86_FEATURE_ARAT))
1770 		tick_broadcast_enable();
1771 
1772 	/*
1773 	 * Some systems can hotplug a cpu at runtime after
1774 	 * the kernel has booted, we have to initialize the
1775 	 * driver in this case
1776 	 */
1777 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1778 	if (!dev->registered)
1779 		return intel_idle_cpu_init(cpu);
1780 
1781 	return 0;
1782 }
1783 
1784 /**
1785  * intel_idle_cpuidle_devices_uninit - Unregister all cpuidle devices.
1786  */
1787 static void __init intel_idle_cpuidle_devices_uninit(void)
1788 {
1789 	int i;
1790 
1791 	for_each_online_cpu(i)
1792 		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
1793 }
1794 
1795 static int __init intel_idle_init(void)
1796 {
1797 	const struct x86_cpu_id *id;
1798 	unsigned int eax, ebx, ecx;
1799 	int retval;
1800 
1801 	/* Do not load intel_idle at all for now if idle= is passed */
1802 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1803 		return -ENODEV;
1804 
1805 	if (max_cstate == 0) {
1806 		pr_debug("disabled\n");
1807 		return -EPERM;
1808 	}
1809 
1810 	id = x86_match_cpu(intel_idle_ids);
1811 	if (id) {
1812 		if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1813 			pr_debug("Please enable MWAIT in BIOS SETUP\n");
1814 			return -ENODEV;
1815 		}
1816 	} else {
1817 		id = x86_match_cpu(intel_mwait_ids);
1818 		if (!id)
1819 			return -ENODEV;
1820 	}
1821 
1822 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1823 		return -ENODEV;
1824 
1825 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1826 
1827 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1828 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1829 	    !mwait_substates)
1830 			return -ENODEV;
1831 
1832 	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1833 
1834 	icpu = (const struct idle_cpu *)id->driver_data;
1835 	if (icpu) {
1836 		cpuidle_state_table = icpu->state_table;
1837 		auto_demotion_disable_flags = icpu->auto_demotion_disable_flags;
1838 		if (icpu->disable_promotion_to_c1e)
1839 			c1e_promotion = C1E_PROMOTION_DISABLE;
1840 		if (icpu->use_acpi || force_use_acpi)
1841 			intel_idle_acpi_cst_extract();
1842 	} else if (!intel_idle_acpi_cst_extract()) {
1843 		return -ENODEV;
1844 	}
1845 
1846 	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1847 		 boot_cpu_data.x86_model);
1848 
1849 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1850 	if (!intel_idle_cpuidle_devices)
1851 		return -ENOMEM;
1852 
1853 	intel_idle_cpuidle_driver_init(&intel_idle_driver);
1854 
1855 	retval = cpuidle_register_driver(&intel_idle_driver);
1856 	if (retval) {
1857 		struct cpuidle_driver *drv = cpuidle_get_driver();
1858 		printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1859 		       drv ? drv->name : "none");
1860 		goto init_driver_fail;
1861 	}
1862 
1863 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1864 				   intel_idle_cpu_online, NULL);
1865 	if (retval < 0)
1866 		goto hp_setup_fail;
1867 
1868 	pr_debug("Local APIC timer is reliable in %s\n",
1869 		 boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
1870 
1871 	return 0;
1872 
1873 hp_setup_fail:
1874 	intel_idle_cpuidle_devices_uninit();
1875 	cpuidle_unregister_driver(&intel_idle_driver);
1876 init_driver_fail:
1877 	free_percpu(intel_idle_cpuidle_devices);
1878 	return retval;
1879 
1880 }
1881 device_initcall(intel_idle_init);
1882 
1883 /*
1884  * We are not really modular, but we used to support that.  Meaning we also
1885  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1886  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1887  * is the easiest way (currently) to continue doing that.
1888  */
1889 module_param(max_cstate, int, 0444);
1890 /*
1891  * The positions of the bits that are set in this number are the indices of the
1892  * idle states to be disabled by default (as reflected by the names of the
1893  * corresponding idle state directories in sysfs, "state0", "state1" ...
1894  * "state<i>" ..., where <i> is the index of the given state).
1895  */
1896 module_param_named(states_off, disabled_states_mask, uint, 0444);
1897 MODULE_PARM_DESC(states_off, "Mask of disabled idle states");
1898 /*
1899  * Some platforms come with mutually exclusive C-states, so that if one is
1900  * enabled, the other C-states must not be used. Example: C1 and C1E on
1901  * Sapphire Rapids platform. This parameter allows for selecting the
1902  * preferred C-states among the groups of mutually exclusive C-states - the
1903  * selected C-states will be registered, the other C-states from the mutually
1904  * exclusive group won't be registered. If the platform has no mutually
1905  * exclusive C-states, this parameter has no effect.
1906  */
1907 module_param_named(preferred_cstates, preferred_states_mask, uint, 0444);
1908 MODULE_PARM_DESC(preferred_cstates, "Mask of preferred idle states");
1909