xref: /openbmc/linux/drivers/idle/intel_idle.c (revision 67559900)
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 interrupts before entering the C-state. On some platforms and for
93  * some C-states, this may measurably decrease interrupt latency.
94  */
95 #define CPUIDLE_FLAG_IRQ_ENABLE		BIT(14)
96 
97 /*
98  * Enable this state by default even if the ACPI _CST does not list it.
99  */
100 #define CPUIDLE_FLAG_ALWAYS_ENABLE	BIT(15)
101 
102 /*
103  * MWAIT takes an 8-bit "hint" in EAX "suggesting"
104  * the C-state (top nibble) and sub-state (bottom nibble)
105  * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
106  *
107  * We store the hint at the top of our "flags" for each state.
108  */
109 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
110 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
111 
112 /**
113  * intel_idle - Ask the processor to enter the given idle state.
114  * @dev: cpuidle device of the target CPU.
115  * @drv: cpuidle driver (assumed to point to intel_idle_driver).
116  * @index: Target idle state index.
117  *
118  * Use the MWAIT instruction to notify the processor that the CPU represented by
119  * @dev is idle and it can try to enter the idle state corresponding to @index.
120  *
121  * If the local APIC timer is not known to be reliable in the target idle state,
122  * enable one-shot tick broadcasting for the target CPU before executing MWAIT.
123  *
124  * Optionally call leave_mm() for the target CPU upfront to avoid wakeups due to
125  * flushing user TLBs.
126  *
127  * Must be called under local_irq_disable().
128  */
129 static __cpuidle int intel_idle(struct cpuidle_device *dev,
130 				struct cpuidle_driver *drv, int index)
131 {
132 	struct cpuidle_state *state = &drv->states[index];
133 	unsigned long eax = flg2MWAIT(state->flags);
134 	unsigned long ecx = 1; /* break on interrupt flag */
135 
136 	if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE)
137 		local_irq_enable();
138 
139 	mwait_idle_with_hints(eax, ecx);
140 
141 	return index;
142 }
143 
144 /**
145  * intel_idle_s2idle - Ask the processor to enter the given idle state.
146  * @dev: cpuidle device of the target CPU.
147  * @drv: cpuidle driver (assumed to point to intel_idle_driver).
148  * @index: Target idle state index.
149  *
150  * Use the MWAIT instruction to notify the processor that the CPU represented by
151  * @dev is idle and it can try to enter the idle state corresponding to @index.
152  *
153  * Invoked as a suspend-to-idle callback routine with frozen user space, frozen
154  * scheduler tick and suspended scheduler clock on the target CPU.
155  */
156 static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev,
157 				       struct cpuidle_driver *drv, int index)
158 {
159 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
160 	unsigned long ecx = 1; /* break on interrupt flag */
161 
162 	mwait_idle_with_hints(eax, ecx);
163 
164 	return 0;
165 }
166 
167 /*
168  * States are indexed by the cstate number,
169  * which is also the index into the MWAIT hint array.
170  * Thus C0 is a dummy.
171  */
172 static struct cpuidle_state nehalem_cstates[] __initdata = {
173 	{
174 		.name = "C1",
175 		.desc = "MWAIT 0x00",
176 		.flags = MWAIT2flg(0x00),
177 		.exit_latency = 3,
178 		.target_residency = 6,
179 		.enter = &intel_idle,
180 		.enter_s2idle = intel_idle_s2idle, },
181 	{
182 		.name = "C1E",
183 		.desc = "MWAIT 0x01",
184 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
185 		.exit_latency = 10,
186 		.target_residency = 20,
187 		.enter = &intel_idle,
188 		.enter_s2idle = intel_idle_s2idle, },
189 	{
190 		.name = "C3",
191 		.desc = "MWAIT 0x10",
192 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
193 		.exit_latency = 20,
194 		.target_residency = 80,
195 		.enter = &intel_idle,
196 		.enter_s2idle = intel_idle_s2idle, },
197 	{
198 		.name = "C6",
199 		.desc = "MWAIT 0x20",
200 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
201 		.exit_latency = 200,
202 		.target_residency = 800,
203 		.enter = &intel_idle,
204 		.enter_s2idle = intel_idle_s2idle, },
205 	{
206 		.enter = NULL }
207 };
208 
209 static struct cpuidle_state snb_cstates[] __initdata = {
210 	{
211 		.name = "C1",
212 		.desc = "MWAIT 0x00",
213 		.flags = MWAIT2flg(0x00),
214 		.exit_latency = 2,
215 		.target_residency = 2,
216 		.enter = &intel_idle,
217 		.enter_s2idle = intel_idle_s2idle, },
218 	{
219 		.name = "C1E",
220 		.desc = "MWAIT 0x01",
221 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
222 		.exit_latency = 10,
223 		.target_residency = 20,
224 		.enter = &intel_idle,
225 		.enter_s2idle = intel_idle_s2idle, },
226 	{
227 		.name = "C3",
228 		.desc = "MWAIT 0x10",
229 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
230 		.exit_latency = 80,
231 		.target_residency = 211,
232 		.enter = &intel_idle,
233 		.enter_s2idle = intel_idle_s2idle, },
234 	{
235 		.name = "C6",
236 		.desc = "MWAIT 0x20",
237 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
238 		.exit_latency = 104,
239 		.target_residency = 345,
240 		.enter = &intel_idle,
241 		.enter_s2idle = intel_idle_s2idle, },
242 	{
243 		.name = "C7",
244 		.desc = "MWAIT 0x30",
245 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
246 		.exit_latency = 109,
247 		.target_residency = 345,
248 		.enter = &intel_idle,
249 		.enter_s2idle = intel_idle_s2idle, },
250 	{
251 		.enter = NULL }
252 };
253 
254 static struct cpuidle_state byt_cstates[] __initdata = {
255 	{
256 		.name = "C1",
257 		.desc = "MWAIT 0x00",
258 		.flags = MWAIT2flg(0x00),
259 		.exit_latency = 1,
260 		.target_residency = 1,
261 		.enter = &intel_idle,
262 		.enter_s2idle = intel_idle_s2idle, },
263 	{
264 		.name = "C6N",
265 		.desc = "MWAIT 0x58",
266 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
267 		.exit_latency = 300,
268 		.target_residency = 275,
269 		.enter = &intel_idle,
270 		.enter_s2idle = intel_idle_s2idle, },
271 	{
272 		.name = "C6S",
273 		.desc = "MWAIT 0x52",
274 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
275 		.exit_latency = 500,
276 		.target_residency = 560,
277 		.enter = &intel_idle,
278 		.enter_s2idle = intel_idle_s2idle, },
279 	{
280 		.name = "C7",
281 		.desc = "MWAIT 0x60",
282 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
283 		.exit_latency = 1200,
284 		.target_residency = 4000,
285 		.enter = &intel_idle,
286 		.enter_s2idle = intel_idle_s2idle, },
287 	{
288 		.name = "C7S",
289 		.desc = "MWAIT 0x64",
290 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
291 		.exit_latency = 10000,
292 		.target_residency = 20000,
293 		.enter = &intel_idle,
294 		.enter_s2idle = intel_idle_s2idle, },
295 	{
296 		.enter = NULL }
297 };
298 
299 static struct cpuidle_state cht_cstates[] __initdata = {
300 	{
301 		.name = "C1",
302 		.desc = "MWAIT 0x00",
303 		.flags = MWAIT2flg(0x00),
304 		.exit_latency = 1,
305 		.target_residency = 1,
306 		.enter = &intel_idle,
307 		.enter_s2idle = intel_idle_s2idle, },
308 	{
309 		.name = "C6N",
310 		.desc = "MWAIT 0x58",
311 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
312 		.exit_latency = 80,
313 		.target_residency = 275,
314 		.enter = &intel_idle,
315 		.enter_s2idle = intel_idle_s2idle, },
316 	{
317 		.name = "C6S",
318 		.desc = "MWAIT 0x52",
319 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
320 		.exit_latency = 200,
321 		.target_residency = 560,
322 		.enter = &intel_idle,
323 		.enter_s2idle = intel_idle_s2idle, },
324 	{
325 		.name = "C7",
326 		.desc = "MWAIT 0x60",
327 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
328 		.exit_latency = 1200,
329 		.target_residency = 4000,
330 		.enter = &intel_idle,
331 		.enter_s2idle = intel_idle_s2idle, },
332 	{
333 		.name = "C7S",
334 		.desc = "MWAIT 0x64",
335 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
336 		.exit_latency = 10000,
337 		.target_residency = 20000,
338 		.enter = &intel_idle,
339 		.enter_s2idle = intel_idle_s2idle, },
340 	{
341 		.enter = NULL }
342 };
343 
344 static struct cpuidle_state ivb_cstates[] __initdata = {
345 	{
346 		.name = "C1",
347 		.desc = "MWAIT 0x00",
348 		.flags = MWAIT2flg(0x00),
349 		.exit_latency = 1,
350 		.target_residency = 1,
351 		.enter = &intel_idle,
352 		.enter_s2idle = intel_idle_s2idle, },
353 	{
354 		.name = "C1E",
355 		.desc = "MWAIT 0x01",
356 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
357 		.exit_latency = 10,
358 		.target_residency = 20,
359 		.enter = &intel_idle,
360 		.enter_s2idle = intel_idle_s2idle, },
361 	{
362 		.name = "C3",
363 		.desc = "MWAIT 0x10",
364 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
365 		.exit_latency = 59,
366 		.target_residency = 156,
367 		.enter = &intel_idle,
368 		.enter_s2idle = intel_idle_s2idle, },
369 	{
370 		.name = "C6",
371 		.desc = "MWAIT 0x20",
372 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
373 		.exit_latency = 80,
374 		.target_residency = 300,
375 		.enter = &intel_idle,
376 		.enter_s2idle = intel_idle_s2idle, },
377 	{
378 		.name = "C7",
379 		.desc = "MWAIT 0x30",
380 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
381 		.exit_latency = 87,
382 		.target_residency = 300,
383 		.enter = &intel_idle,
384 		.enter_s2idle = intel_idle_s2idle, },
385 	{
386 		.enter = NULL }
387 };
388 
389 static struct cpuidle_state ivt_cstates[] __initdata = {
390 	{
391 		.name = "C1",
392 		.desc = "MWAIT 0x00",
393 		.flags = MWAIT2flg(0x00),
394 		.exit_latency = 1,
395 		.target_residency = 1,
396 		.enter = &intel_idle,
397 		.enter_s2idle = intel_idle_s2idle, },
398 	{
399 		.name = "C1E",
400 		.desc = "MWAIT 0x01",
401 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
402 		.exit_latency = 10,
403 		.target_residency = 80,
404 		.enter = &intel_idle,
405 		.enter_s2idle = intel_idle_s2idle, },
406 	{
407 		.name = "C3",
408 		.desc = "MWAIT 0x10",
409 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
410 		.exit_latency = 59,
411 		.target_residency = 156,
412 		.enter = &intel_idle,
413 		.enter_s2idle = intel_idle_s2idle, },
414 	{
415 		.name = "C6",
416 		.desc = "MWAIT 0x20",
417 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
418 		.exit_latency = 82,
419 		.target_residency = 300,
420 		.enter = &intel_idle,
421 		.enter_s2idle = intel_idle_s2idle, },
422 	{
423 		.enter = NULL }
424 };
425 
426 static struct cpuidle_state ivt_cstates_4s[] __initdata = {
427 	{
428 		.name = "C1",
429 		.desc = "MWAIT 0x00",
430 		.flags = MWAIT2flg(0x00),
431 		.exit_latency = 1,
432 		.target_residency = 1,
433 		.enter = &intel_idle,
434 		.enter_s2idle = intel_idle_s2idle, },
435 	{
436 		.name = "C1E",
437 		.desc = "MWAIT 0x01",
438 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
439 		.exit_latency = 10,
440 		.target_residency = 250,
441 		.enter = &intel_idle,
442 		.enter_s2idle = intel_idle_s2idle, },
443 	{
444 		.name = "C3",
445 		.desc = "MWAIT 0x10",
446 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
447 		.exit_latency = 59,
448 		.target_residency = 300,
449 		.enter = &intel_idle,
450 		.enter_s2idle = intel_idle_s2idle, },
451 	{
452 		.name = "C6",
453 		.desc = "MWAIT 0x20",
454 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
455 		.exit_latency = 84,
456 		.target_residency = 400,
457 		.enter = &intel_idle,
458 		.enter_s2idle = intel_idle_s2idle, },
459 	{
460 		.enter = NULL }
461 };
462 
463 static struct cpuidle_state ivt_cstates_8s[] __initdata = {
464 	{
465 		.name = "C1",
466 		.desc = "MWAIT 0x00",
467 		.flags = MWAIT2flg(0x00),
468 		.exit_latency = 1,
469 		.target_residency = 1,
470 		.enter = &intel_idle,
471 		.enter_s2idle = intel_idle_s2idle, },
472 	{
473 		.name = "C1E",
474 		.desc = "MWAIT 0x01",
475 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
476 		.exit_latency = 10,
477 		.target_residency = 500,
478 		.enter = &intel_idle,
479 		.enter_s2idle = intel_idle_s2idle, },
480 	{
481 		.name = "C3",
482 		.desc = "MWAIT 0x10",
483 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
484 		.exit_latency = 59,
485 		.target_residency = 600,
486 		.enter = &intel_idle,
487 		.enter_s2idle = intel_idle_s2idle, },
488 	{
489 		.name = "C6",
490 		.desc = "MWAIT 0x20",
491 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
492 		.exit_latency = 88,
493 		.target_residency = 700,
494 		.enter = &intel_idle,
495 		.enter_s2idle = intel_idle_s2idle, },
496 	{
497 		.enter = NULL }
498 };
499 
500 static struct cpuidle_state hsw_cstates[] __initdata = {
501 	{
502 		.name = "C1",
503 		.desc = "MWAIT 0x00",
504 		.flags = MWAIT2flg(0x00),
505 		.exit_latency = 2,
506 		.target_residency = 2,
507 		.enter = &intel_idle,
508 		.enter_s2idle = intel_idle_s2idle, },
509 	{
510 		.name = "C1E",
511 		.desc = "MWAIT 0x01",
512 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
513 		.exit_latency = 10,
514 		.target_residency = 20,
515 		.enter = &intel_idle,
516 		.enter_s2idle = intel_idle_s2idle, },
517 	{
518 		.name = "C3",
519 		.desc = "MWAIT 0x10",
520 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
521 		.exit_latency = 33,
522 		.target_residency = 100,
523 		.enter = &intel_idle,
524 		.enter_s2idle = intel_idle_s2idle, },
525 	{
526 		.name = "C6",
527 		.desc = "MWAIT 0x20",
528 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
529 		.exit_latency = 133,
530 		.target_residency = 400,
531 		.enter = &intel_idle,
532 		.enter_s2idle = intel_idle_s2idle, },
533 	{
534 		.name = "C7s",
535 		.desc = "MWAIT 0x32",
536 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
537 		.exit_latency = 166,
538 		.target_residency = 500,
539 		.enter = &intel_idle,
540 		.enter_s2idle = intel_idle_s2idle, },
541 	{
542 		.name = "C8",
543 		.desc = "MWAIT 0x40",
544 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
545 		.exit_latency = 300,
546 		.target_residency = 900,
547 		.enter = &intel_idle,
548 		.enter_s2idle = intel_idle_s2idle, },
549 	{
550 		.name = "C9",
551 		.desc = "MWAIT 0x50",
552 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
553 		.exit_latency = 600,
554 		.target_residency = 1800,
555 		.enter = &intel_idle,
556 		.enter_s2idle = intel_idle_s2idle, },
557 	{
558 		.name = "C10",
559 		.desc = "MWAIT 0x60",
560 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
561 		.exit_latency = 2600,
562 		.target_residency = 7700,
563 		.enter = &intel_idle,
564 		.enter_s2idle = intel_idle_s2idle, },
565 	{
566 		.enter = NULL }
567 };
568 static struct cpuidle_state bdw_cstates[] __initdata = {
569 	{
570 		.name = "C1",
571 		.desc = "MWAIT 0x00",
572 		.flags = MWAIT2flg(0x00),
573 		.exit_latency = 2,
574 		.target_residency = 2,
575 		.enter = &intel_idle,
576 		.enter_s2idle = intel_idle_s2idle, },
577 	{
578 		.name = "C1E",
579 		.desc = "MWAIT 0x01",
580 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
581 		.exit_latency = 10,
582 		.target_residency = 20,
583 		.enter = &intel_idle,
584 		.enter_s2idle = intel_idle_s2idle, },
585 	{
586 		.name = "C3",
587 		.desc = "MWAIT 0x10",
588 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
589 		.exit_latency = 40,
590 		.target_residency = 100,
591 		.enter = &intel_idle,
592 		.enter_s2idle = intel_idle_s2idle, },
593 	{
594 		.name = "C6",
595 		.desc = "MWAIT 0x20",
596 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
597 		.exit_latency = 133,
598 		.target_residency = 400,
599 		.enter = &intel_idle,
600 		.enter_s2idle = intel_idle_s2idle, },
601 	{
602 		.name = "C7s",
603 		.desc = "MWAIT 0x32",
604 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
605 		.exit_latency = 166,
606 		.target_residency = 500,
607 		.enter = &intel_idle,
608 		.enter_s2idle = intel_idle_s2idle, },
609 	{
610 		.name = "C8",
611 		.desc = "MWAIT 0x40",
612 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
613 		.exit_latency = 300,
614 		.target_residency = 900,
615 		.enter = &intel_idle,
616 		.enter_s2idle = intel_idle_s2idle, },
617 	{
618 		.name = "C9",
619 		.desc = "MWAIT 0x50",
620 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
621 		.exit_latency = 600,
622 		.target_residency = 1800,
623 		.enter = &intel_idle,
624 		.enter_s2idle = intel_idle_s2idle, },
625 	{
626 		.name = "C10",
627 		.desc = "MWAIT 0x60",
628 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
629 		.exit_latency = 2600,
630 		.target_residency = 7700,
631 		.enter = &intel_idle,
632 		.enter_s2idle = intel_idle_s2idle, },
633 	{
634 		.enter = NULL }
635 };
636 
637 static struct cpuidle_state skl_cstates[] __initdata = {
638 	{
639 		.name = "C1",
640 		.desc = "MWAIT 0x00",
641 		.flags = MWAIT2flg(0x00),
642 		.exit_latency = 2,
643 		.target_residency = 2,
644 		.enter = &intel_idle,
645 		.enter_s2idle = intel_idle_s2idle, },
646 	{
647 		.name = "C1E",
648 		.desc = "MWAIT 0x01",
649 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
650 		.exit_latency = 10,
651 		.target_residency = 20,
652 		.enter = &intel_idle,
653 		.enter_s2idle = intel_idle_s2idle, },
654 	{
655 		.name = "C3",
656 		.desc = "MWAIT 0x10",
657 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
658 		.exit_latency = 70,
659 		.target_residency = 100,
660 		.enter = &intel_idle,
661 		.enter_s2idle = intel_idle_s2idle, },
662 	{
663 		.name = "C6",
664 		.desc = "MWAIT 0x20",
665 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
666 		.exit_latency = 85,
667 		.target_residency = 200,
668 		.enter = &intel_idle,
669 		.enter_s2idle = intel_idle_s2idle, },
670 	{
671 		.name = "C7s",
672 		.desc = "MWAIT 0x33",
673 		.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
674 		.exit_latency = 124,
675 		.target_residency = 800,
676 		.enter = &intel_idle,
677 		.enter_s2idle = intel_idle_s2idle, },
678 	{
679 		.name = "C8",
680 		.desc = "MWAIT 0x40",
681 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
682 		.exit_latency = 200,
683 		.target_residency = 800,
684 		.enter = &intel_idle,
685 		.enter_s2idle = intel_idle_s2idle, },
686 	{
687 		.name = "C9",
688 		.desc = "MWAIT 0x50",
689 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
690 		.exit_latency = 480,
691 		.target_residency = 5000,
692 		.enter = &intel_idle,
693 		.enter_s2idle = intel_idle_s2idle, },
694 	{
695 		.name = "C10",
696 		.desc = "MWAIT 0x60",
697 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
698 		.exit_latency = 890,
699 		.target_residency = 5000,
700 		.enter = &intel_idle,
701 		.enter_s2idle = intel_idle_s2idle, },
702 	{
703 		.enter = NULL }
704 };
705 
706 static struct cpuidle_state skx_cstates[] __initdata = {
707 	{
708 		.name = "C1",
709 		.desc = "MWAIT 0x00",
710 		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_IRQ_ENABLE,
711 		.exit_latency = 2,
712 		.target_residency = 2,
713 		.enter = &intel_idle,
714 		.enter_s2idle = intel_idle_s2idle, },
715 	{
716 		.name = "C1E",
717 		.desc = "MWAIT 0x01",
718 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
719 		.exit_latency = 10,
720 		.target_residency = 20,
721 		.enter = &intel_idle,
722 		.enter_s2idle = intel_idle_s2idle, },
723 	{
724 		.name = "C6",
725 		.desc = "MWAIT 0x20",
726 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
727 		.exit_latency = 133,
728 		.target_residency = 600,
729 		.enter = &intel_idle,
730 		.enter_s2idle = intel_idle_s2idle, },
731 	{
732 		.enter = NULL }
733 };
734 
735 static struct cpuidle_state icx_cstates[] __initdata = {
736 	{
737 		.name = "C1",
738 		.desc = "MWAIT 0x00",
739 		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_IRQ_ENABLE,
740 		.exit_latency = 1,
741 		.target_residency = 1,
742 		.enter = &intel_idle,
743 		.enter_s2idle = intel_idle_s2idle, },
744 	{
745 		.name = "C1E",
746 		.desc = "MWAIT 0x01",
747 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
748 		.exit_latency = 4,
749 		.target_residency = 4,
750 		.enter = &intel_idle,
751 		.enter_s2idle = intel_idle_s2idle, },
752 	{
753 		.name = "C6",
754 		.desc = "MWAIT 0x20",
755 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
756 		.exit_latency = 170,
757 		.target_residency = 600,
758 		.enter = &intel_idle,
759 		.enter_s2idle = intel_idle_s2idle, },
760 	{
761 		.enter = NULL }
762 };
763 
764 static struct cpuidle_state atom_cstates[] __initdata = {
765 	{
766 		.name = "C1E",
767 		.desc = "MWAIT 0x00",
768 		.flags = MWAIT2flg(0x00),
769 		.exit_latency = 10,
770 		.target_residency = 20,
771 		.enter = &intel_idle,
772 		.enter_s2idle = intel_idle_s2idle, },
773 	{
774 		.name = "C2",
775 		.desc = "MWAIT 0x10",
776 		.flags = MWAIT2flg(0x10),
777 		.exit_latency = 20,
778 		.target_residency = 80,
779 		.enter = &intel_idle,
780 		.enter_s2idle = intel_idle_s2idle, },
781 	{
782 		.name = "C4",
783 		.desc = "MWAIT 0x30",
784 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
785 		.exit_latency = 100,
786 		.target_residency = 400,
787 		.enter = &intel_idle,
788 		.enter_s2idle = intel_idle_s2idle, },
789 	{
790 		.name = "C6",
791 		.desc = "MWAIT 0x52",
792 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
793 		.exit_latency = 140,
794 		.target_residency = 560,
795 		.enter = &intel_idle,
796 		.enter_s2idle = intel_idle_s2idle, },
797 	{
798 		.enter = NULL }
799 };
800 static struct cpuidle_state tangier_cstates[] __initdata = {
801 	{
802 		.name = "C1",
803 		.desc = "MWAIT 0x00",
804 		.flags = MWAIT2flg(0x00),
805 		.exit_latency = 1,
806 		.target_residency = 4,
807 		.enter = &intel_idle,
808 		.enter_s2idle = intel_idle_s2idle, },
809 	{
810 		.name = "C4",
811 		.desc = "MWAIT 0x30",
812 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
813 		.exit_latency = 100,
814 		.target_residency = 400,
815 		.enter = &intel_idle,
816 		.enter_s2idle = intel_idle_s2idle, },
817 	{
818 		.name = "C6",
819 		.desc = "MWAIT 0x52",
820 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
821 		.exit_latency = 140,
822 		.target_residency = 560,
823 		.enter = &intel_idle,
824 		.enter_s2idle = intel_idle_s2idle, },
825 	{
826 		.name = "C7",
827 		.desc = "MWAIT 0x60",
828 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
829 		.exit_latency = 1200,
830 		.target_residency = 4000,
831 		.enter = &intel_idle,
832 		.enter_s2idle = intel_idle_s2idle, },
833 	{
834 		.name = "C9",
835 		.desc = "MWAIT 0x64",
836 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
837 		.exit_latency = 10000,
838 		.target_residency = 20000,
839 		.enter = &intel_idle,
840 		.enter_s2idle = intel_idle_s2idle, },
841 	{
842 		.enter = NULL }
843 };
844 static struct cpuidle_state avn_cstates[] __initdata = {
845 	{
846 		.name = "C1",
847 		.desc = "MWAIT 0x00",
848 		.flags = MWAIT2flg(0x00),
849 		.exit_latency = 2,
850 		.target_residency = 2,
851 		.enter = &intel_idle,
852 		.enter_s2idle = intel_idle_s2idle, },
853 	{
854 		.name = "C6",
855 		.desc = "MWAIT 0x51",
856 		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
857 		.exit_latency = 15,
858 		.target_residency = 45,
859 		.enter = &intel_idle,
860 		.enter_s2idle = intel_idle_s2idle, },
861 	{
862 		.enter = NULL }
863 };
864 static struct cpuidle_state knl_cstates[] __initdata = {
865 	{
866 		.name = "C1",
867 		.desc = "MWAIT 0x00",
868 		.flags = MWAIT2flg(0x00),
869 		.exit_latency = 1,
870 		.target_residency = 2,
871 		.enter = &intel_idle,
872 		.enter_s2idle = intel_idle_s2idle },
873 	{
874 		.name = "C6",
875 		.desc = "MWAIT 0x10",
876 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
877 		.exit_latency = 120,
878 		.target_residency = 500,
879 		.enter = &intel_idle,
880 		.enter_s2idle = intel_idle_s2idle },
881 	{
882 		.enter = NULL }
883 };
884 
885 static struct cpuidle_state bxt_cstates[] __initdata = {
886 	{
887 		.name = "C1",
888 		.desc = "MWAIT 0x00",
889 		.flags = MWAIT2flg(0x00),
890 		.exit_latency = 2,
891 		.target_residency = 2,
892 		.enter = &intel_idle,
893 		.enter_s2idle = intel_idle_s2idle, },
894 	{
895 		.name = "C1E",
896 		.desc = "MWAIT 0x01",
897 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
898 		.exit_latency = 10,
899 		.target_residency = 20,
900 		.enter = &intel_idle,
901 		.enter_s2idle = intel_idle_s2idle, },
902 	{
903 		.name = "C6",
904 		.desc = "MWAIT 0x20",
905 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
906 		.exit_latency = 133,
907 		.target_residency = 133,
908 		.enter = &intel_idle,
909 		.enter_s2idle = intel_idle_s2idle, },
910 	{
911 		.name = "C7s",
912 		.desc = "MWAIT 0x31",
913 		.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
914 		.exit_latency = 155,
915 		.target_residency = 155,
916 		.enter = &intel_idle,
917 		.enter_s2idle = intel_idle_s2idle, },
918 	{
919 		.name = "C8",
920 		.desc = "MWAIT 0x40",
921 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
922 		.exit_latency = 1000,
923 		.target_residency = 1000,
924 		.enter = &intel_idle,
925 		.enter_s2idle = intel_idle_s2idle, },
926 	{
927 		.name = "C9",
928 		.desc = "MWAIT 0x50",
929 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
930 		.exit_latency = 2000,
931 		.target_residency = 2000,
932 		.enter = &intel_idle,
933 		.enter_s2idle = intel_idle_s2idle, },
934 	{
935 		.name = "C10",
936 		.desc = "MWAIT 0x60",
937 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
938 		.exit_latency = 10000,
939 		.target_residency = 10000,
940 		.enter = &intel_idle,
941 		.enter_s2idle = intel_idle_s2idle, },
942 	{
943 		.enter = NULL }
944 };
945 
946 static struct cpuidle_state dnv_cstates[] __initdata = {
947 	{
948 		.name = "C1",
949 		.desc = "MWAIT 0x00",
950 		.flags = MWAIT2flg(0x00),
951 		.exit_latency = 2,
952 		.target_residency = 2,
953 		.enter = &intel_idle,
954 		.enter_s2idle = intel_idle_s2idle, },
955 	{
956 		.name = "C1E",
957 		.desc = "MWAIT 0x01",
958 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
959 		.exit_latency = 10,
960 		.target_residency = 20,
961 		.enter = &intel_idle,
962 		.enter_s2idle = intel_idle_s2idle, },
963 	{
964 		.name = "C6",
965 		.desc = "MWAIT 0x20",
966 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
967 		.exit_latency = 50,
968 		.target_residency = 500,
969 		.enter = &intel_idle,
970 		.enter_s2idle = intel_idle_s2idle, },
971 	{
972 		.enter = NULL }
973 };
974 
975 /*
976  * Note, depending on HW and FW revision, SnowRidge SoC may or may not support
977  * C6, and this is indicated in the CPUID mwait leaf.
978  */
979 static struct cpuidle_state snr_cstates[] __initdata = {
980 	{
981 		.name = "C1",
982 		.desc = "MWAIT 0x00",
983 		.flags = MWAIT2flg(0x00),
984 		.exit_latency = 2,
985 		.target_residency = 2,
986 		.enter = &intel_idle,
987 		.enter_s2idle = intel_idle_s2idle, },
988 	{
989 		.name = "C1E",
990 		.desc = "MWAIT 0x01",
991 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
992 		.exit_latency = 15,
993 		.target_residency = 25,
994 		.enter = &intel_idle,
995 		.enter_s2idle = intel_idle_s2idle, },
996 	{
997 		.name = "C6",
998 		.desc = "MWAIT 0x20",
999 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
1000 		.exit_latency = 130,
1001 		.target_residency = 500,
1002 		.enter = &intel_idle,
1003 		.enter_s2idle = intel_idle_s2idle, },
1004 	{
1005 		.enter = NULL }
1006 };
1007 
1008 static const struct idle_cpu idle_cpu_nehalem __initconst = {
1009 	.state_table = nehalem_cstates,
1010 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
1011 	.disable_promotion_to_c1e = true,
1012 };
1013 
1014 static const struct idle_cpu idle_cpu_nhx __initconst = {
1015 	.state_table = nehalem_cstates,
1016 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
1017 	.disable_promotion_to_c1e = true,
1018 	.use_acpi = true,
1019 };
1020 
1021 static const struct idle_cpu idle_cpu_atom __initconst = {
1022 	.state_table = atom_cstates,
1023 };
1024 
1025 static const struct idle_cpu idle_cpu_tangier __initconst = {
1026 	.state_table = tangier_cstates,
1027 };
1028 
1029 static const struct idle_cpu idle_cpu_lincroft __initconst = {
1030 	.state_table = atom_cstates,
1031 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
1032 };
1033 
1034 static const struct idle_cpu idle_cpu_snb __initconst = {
1035 	.state_table = snb_cstates,
1036 	.disable_promotion_to_c1e = true,
1037 };
1038 
1039 static const struct idle_cpu idle_cpu_snx __initconst = {
1040 	.state_table = snb_cstates,
1041 	.disable_promotion_to_c1e = true,
1042 	.use_acpi = true,
1043 };
1044 
1045 static const struct idle_cpu idle_cpu_byt __initconst = {
1046 	.state_table = byt_cstates,
1047 	.disable_promotion_to_c1e = true,
1048 	.byt_auto_demotion_disable_flag = true,
1049 };
1050 
1051 static const struct idle_cpu idle_cpu_cht __initconst = {
1052 	.state_table = cht_cstates,
1053 	.disable_promotion_to_c1e = true,
1054 	.byt_auto_demotion_disable_flag = true,
1055 };
1056 
1057 static const struct idle_cpu idle_cpu_ivb __initconst = {
1058 	.state_table = ivb_cstates,
1059 	.disable_promotion_to_c1e = true,
1060 };
1061 
1062 static const struct idle_cpu idle_cpu_ivt __initconst = {
1063 	.state_table = ivt_cstates,
1064 	.disable_promotion_to_c1e = true,
1065 	.use_acpi = true,
1066 };
1067 
1068 static const struct idle_cpu idle_cpu_hsw __initconst = {
1069 	.state_table = hsw_cstates,
1070 	.disable_promotion_to_c1e = true,
1071 };
1072 
1073 static const struct idle_cpu idle_cpu_hsx __initconst = {
1074 	.state_table = hsw_cstates,
1075 	.disable_promotion_to_c1e = true,
1076 	.use_acpi = true,
1077 };
1078 
1079 static const struct idle_cpu idle_cpu_bdw __initconst = {
1080 	.state_table = bdw_cstates,
1081 	.disable_promotion_to_c1e = true,
1082 };
1083 
1084 static const struct idle_cpu idle_cpu_bdx __initconst = {
1085 	.state_table = bdw_cstates,
1086 	.disable_promotion_to_c1e = true,
1087 	.use_acpi = true,
1088 };
1089 
1090 static const struct idle_cpu idle_cpu_skl __initconst = {
1091 	.state_table = skl_cstates,
1092 	.disable_promotion_to_c1e = true,
1093 };
1094 
1095 static const struct idle_cpu idle_cpu_skx __initconst = {
1096 	.state_table = skx_cstates,
1097 	.disable_promotion_to_c1e = true,
1098 	.use_acpi = true,
1099 };
1100 
1101 static const struct idle_cpu idle_cpu_icx __initconst = {
1102 	.state_table = icx_cstates,
1103 	.disable_promotion_to_c1e = true,
1104 	.use_acpi = true,
1105 };
1106 
1107 static const struct idle_cpu idle_cpu_avn __initconst = {
1108 	.state_table = avn_cstates,
1109 	.disable_promotion_to_c1e = true,
1110 	.use_acpi = true,
1111 };
1112 
1113 static const struct idle_cpu idle_cpu_knl __initconst = {
1114 	.state_table = knl_cstates,
1115 	.use_acpi = true,
1116 };
1117 
1118 static const struct idle_cpu idle_cpu_bxt __initconst = {
1119 	.state_table = bxt_cstates,
1120 	.disable_promotion_to_c1e = true,
1121 };
1122 
1123 static const struct idle_cpu idle_cpu_dnv __initconst = {
1124 	.state_table = dnv_cstates,
1125 	.disable_promotion_to_c1e = true,
1126 	.use_acpi = true,
1127 };
1128 
1129 static const struct idle_cpu idle_cpu_snr __initconst = {
1130 	.state_table = snr_cstates,
1131 	.disable_promotion_to_c1e = true,
1132 	.use_acpi = true,
1133 };
1134 
1135 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1136 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EP,		&idle_cpu_nhx),
1137 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM,		&idle_cpu_nehalem),
1138 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_G,		&idle_cpu_nehalem),
1139 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE,		&idle_cpu_nehalem),
1140 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EP,		&idle_cpu_nhx),
1141 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EX,		&idle_cpu_nhx),
1142 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL,	&idle_cpu_atom),
1143 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL_MID,	&idle_cpu_lincroft),
1144 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EX,		&idle_cpu_nhx),
1145 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE,		&idle_cpu_snb),
1146 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE_X,	&idle_cpu_snx),
1147 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SALTWELL,	&idle_cpu_atom),
1148 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	&idle_cpu_byt),
1149 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID,	&idle_cpu_tangier),
1150 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	&idle_cpu_cht),
1151 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE,		&idle_cpu_ivb),
1152 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE_X,		&idle_cpu_ivt),
1153 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL,		&idle_cpu_hsw),
1154 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X,		&idle_cpu_hsx),
1155 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_L,		&idle_cpu_hsw),
1156 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_G,		&idle_cpu_hsw),
1157 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_D,	&idle_cpu_avn),
1158 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL,		&idle_cpu_bdw),
1159 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_G,		&idle_cpu_bdw),
1160 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X,		&idle_cpu_bdx),
1161 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_D,		&idle_cpu_bdx),
1162 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		&idle_cpu_skl),
1163 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		&idle_cpu_skl),
1164 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		&idle_cpu_skl),
1165 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		&idle_cpu_skl),
1166 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X,		&idle_cpu_skx),
1167 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		&idle_cpu_icx),
1168 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D,		&idle_cpu_icx),
1169 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL,	&idle_cpu_knl),
1170 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM,	&idle_cpu_knl),
1171 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	&idle_cpu_bxt),
1172 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_PLUS,	&idle_cpu_bxt),
1173 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D,	&idle_cpu_dnv),
1174 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	&idle_cpu_snr),
1175 	{}
1176 };
1177 
1178 static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
1179 	X86_MATCH_VENDOR_FAM_FEATURE(INTEL, 6, X86_FEATURE_MWAIT, NULL),
1180 	{}
1181 };
1182 
1183 static bool __init intel_idle_max_cstate_reached(int cstate)
1184 {
1185 	if (cstate + 1 > max_cstate) {
1186 		pr_info("max_cstate %d reached\n", max_cstate);
1187 		return true;
1188 	}
1189 	return false;
1190 }
1191 
1192 static bool __init intel_idle_state_needs_timer_stop(struct cpuidle_state *state)
1193 {
1194 	unsigned long eax = flg2MWAIT(state->flags);
1195 
1196 	if (boot_cpu_has(X86_FEATURE_ARAT))
1197 		return false;
1198 
1199 	/*
1200 	 * Switch over to one-shot tick broadcast if the target C-state
1201 	 * is deeper than C1.
1202 	 */
1203 	return !!((eax >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK);
1204 }
1205 
1206 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
1207 #include <acpi/processor.h>
1208 
1209 static bool no_acpi __read_mostly;
1210 module_param(no_acpi, bool, 0444);
1211 MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list");
1212 
1213 static bool force_use_acpi __read_mostly; /* No effect if no_acpi is set. */
1214 module_param_named(use_acpi, force_use_acpi, bool, 0444);
1215 MODULE_PARM_DESC(use_acpi, "Use ACPI _CST for building the idle states list");
1216 
1217 static struct acpi_processor_power acpi_state_table __initdata;
1218 
1219 /**
1220  * intel_idle_cst_usable - Check if the _CST information can be used.
1221  *
1222  * Check if all of the C-states listed by _CST in the max_cstate range are
1223  * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
1224  */
1225 static bool __init intel_idle_cst_usable(void)
1226 {
1227 	int cstate, limit;
1228 
1229 	limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
1230 		      acpi_state_table.count);
1231 
1232 	for (cstate = 1; cstate < limit; cstate++) {
1233 		struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
1234 
1235 		if (cx->entry_method != ACPI_CSTATE_FFH)
1236 			return false;
1237 	}
1238 
1239 	return true;
1240 }
1241 
1242 static bool __init intel_idle_acpi_cst_extract(void)
1243 {
1244 	unsigned int cpu;
1245 
1246 	if (no_acpi) {
1247 		pr_debug("Not allowed to use ACPI _CST\n");
1248 		return false;
1249 	}
1250 
1251 	for_each_possible_cpu(cpu) {
1252 		struct acpi_processor *pr = per_cpu(processors, cpu);
1253 
1254 		if (!pr)
1255 			continue;
1256 
1257 		if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
1258 			continue;
1259 
1260 		acpi_state_table.count++;
1261 
1262 		if (!intel_idle_cst_usable())
1263 			continue;
1264 
1265 		if (!acpi_processor_claim_cst_control())
1266 			break;
1267 
1268 		return true;
1269 	}
1270 
1271 	acpi_state_table.count = 0;
1272 	pr_debug("ACPI _CST not found or not usable\n");
1273 	return false;
1274 }
1275 
1276 static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
1277 {
1278 	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1279 
1280 	/*
1281 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1282 	 * the interesting states are ACPI_CSTATE_FFH.
1283 	 */
1284 	for (cstate = 1; cstate < limit; cstate++) {
1285 		struct acpi_processor_cx *cx;
1286 		struct cpuidle_state *state;
1287 
1288 		if (intel_idle_max_cstate_reached(cstate - 1))
1289 			break;
1290 
1291 		cx = &acpi_state_table.states[cstate];
1292 
1293 		state = &drv->states[drv->state_count++];
1294 
1295 		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
1296 		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1297 		state->exit_latency = cx->latency;
1298 		/*
1299 		 * For C1-type C-states use the same number for both the exit
1300 		 * latency and target residency, because that is the case for
1301 		 * C1 in the majority of the static C-states tables above.
1302 		 * For the other types of C-states, however, set the target
1303 		 * residency to 3 times the exit latency which should lead to
1304 		 * a reasonable balance between energy-efficiency and
1305 		 * performance in the majority of interesting cases.
1306 		 */
1307 		state->target_residency = cx->latency;
1308 		if (cx->type > ACPI_STATE_C1)
1309 			state->target_residency *= 3;
1310 
1311 		state->flags = MWAIT2flg(cx->address);
1312 		if (cx->type > ACPI_STATE_C2)
1313 			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
1314 
1315 		if (disabled_states_mask & BIT(cstate))
1316 			state->flags |= CPUIDLE_FLAG_OFF;
1317 
1318 		if (intel_idle_state_needs_timer_stop(state))
1319 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1320 
1321 		state->enter = intel_idle;
1322 		state->enter_s2idle = intel_idle_s2idle;
1323 	}
1324 }
1325 
1326 static bool __init intel_idle_off_by_default(u32 mwait_hint)
1327 {
1328 	int cstate, limit;
1329 
1330 	/*
1331 	 * If there are no _CST C-states, do not disable any C-states by
1332 	 * default.
1333 	 */
1334 	if (!acpi_state_table.count)
1335 		return false;
1336 
1337 	limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1338 	/*
1339 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1340 	 * the interesting states are ACPI_CSTATE_FFH.
1341 	 */
1342 	for (cstate = 1; cstate < limit; cstate++) {
1343 		if (acpi_state_table.states[cstate].address == mwait_hint)
1344 			return false;
1345 	}
1346 	return true;
1347 }
1348 #else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1349 #define force_use_acpi	(false)
1350 
1351 static inline bool intel_idle_acpi_cst_extract(void) { return false; }
1352 static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
1353 static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
1354 #endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1355 
1356 /**
1357  * ivt_idle_state_table_update - Tune the idle states table for Ivy Town.
1358  *
1359  * Tune IVT multi-socket targets.
1360  * Assumption: num_sockets == (max_package_num + 1).
1361  */
1362 static void __init ivt_idle_state_table_update(void)
1363 {
1364 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1365 	int cpu, package_num, num_sockets = 1;
1366 
1367 	for_each_online_cpu(cpu) {
1368 		package_num = topology_physical_package_id(cpu);
1369 		if (package_num + 1 > num_sockets) {
1370 			num_sockets = package_num + 1;
1371 
1372 			if (num_sockets > 4) {
1373 				cpuidle_state_table = ivt_cstates_8s;
1374 				return;
1375 			}
1376 		}
1377 	}
1378 
1379 	if (num_sockets > 2)
1380 		cpuidle_state_table = ivt_cstates_4s;
1381 
1382 	/* else, 1 and 2 socket systems use default ivt_cstates */
1383 }
1384 
1385 /**
1386  * irtl_2_usec - IRTL to microseconds conversion.
1387  * @irtl: IRTL MSR value.
1388  *
1389  * Translate the IRTL (Interrupt Response Time Limit) MSR value to microseconds.
1390  */
1391 static unsigned long long __init irtl_2_usec(unsigned long long irtl)
1392 {
1393 	static const unsigned int irtl_ns_units[] __initconst = {
1394 		1, 32, 1024, 32768, 1048576, 33554432, 0, 0
1395 	};
1396 	unsigned long long ns;
1397 
1398 	if (!irtl)
1399 		return 0;
1400 
1401 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1402 
1403 	return div_u64((irtl & 0x3FF) * ns, NSEC_PER_USEC);
1404 }
1405 
1406 /**
1407  * bxt_idle_state_table_update - Fix up the Broxton idle states table.
1408  *
1409  * On BXT, trust the IRTL (Interrupt Response Time Limit) MSR to show the
1410  * definitive maximum latency and use the same value for target_residency.
1411  */
1412 static void __init bxt_idle_state_table_update(void)
1413 {
1414 	unsigned long long msr;
1415 	unsigned int usec;
1416 
1417 	rdmsrl(MSR_PKGC6_IRTL, msr);
1418 	usec = irtl_2_usec(msr);
1419 	if (usec) {
1420 		bxt_cstates[2].exit_latency = usec;
1421 		bxt_cstates[2].target_residency = usec;
1422 	}
1423 
1424 	rdmsrl(MSR_PKGC7_IRTL, msr);
1425 	usec = irtl_2_usec(msr);
1426 	if (usec) {
1427 		bxt_cstates[3].exit_latency = usec;
1428 		bxt_cstates[3].target_residency = usec;
1429 	}
1430 
1431 	rdmsrl(MSR_PKGC8_IRTL, msr);
1432 	usec = irtl_2_usec(msr);
1433 	if (usec) {
1434 		bxt_cstates[4].exit_latency = usec;
1435 		bxt_cstates[4].target_residency = usec;
1436 	}
1437 
1438 	rdmsrl(MSR_PKGC9_IRTL, msr);
1439 	usec = irtl_2_usec(msr);
1440 	if (usec) {
1441 		bxt_cstates[5].exit_latency = usec;
1442 		bxt_cstates[5].target_residency = usec;
1443 	}
1444 
1445 	rdmsrl(MSR_PKGC10_IRTL, msr);
1446 	usec = irtl_2_usec(msr);
1447 	if (usec) {
1448 		bxt_cstates[6].exit_latency = usec;
1449 		bxt_cstates[6].target_residency = usec;
1450 	}
1451 
1452 }
1453 
1454 /**
1455  * sklh_idle_state_table_update - Fix up the Sky Lake idle states table.
1456  *
1457  * On SKL-H (model 0x5e) skip C8 and C9 if C10 is enabled and SGX disabled.
1458  */
1459 static void __init sklh_idle_state_table_update(void)
1460 {
1461 	unsigned long long msr;
1462 	unsigned int eax, ebx, ecx, edx;
1463 
1464 
1465 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1466 	if (max_cstate <= 7)
1467 		return;
1468 
1469 	/* if PC10 not present in CPUID.MWAIT.EDX */
1470 	if ((mwait_substates & (0xF << 28)) == 0)
1471 		return;
1472 
1473 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1474 
1475 	/* PC10 is not enabled in PKG C-state limit */
1476 	if ((msr & 0xF) != 8)
1477 		return;
1478 
1479 	ecx = 0;
1480 	cpuid(7, &eax, &ebx, &ecx, &edx);
1481 
1482 	/* if SGX is present */
1483 	if (ebx & (1 << 2)) {
1484 
1485 		rdmsrl(MSR_IA32_FEAT_CTL, msr);
1486 
1487 		/* if SGX is enabled */
1488 		if (msr & (1 << 18))
1489 			return;
1490 	}
1491 
1492 	skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C8-SKL */
1493 	skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C9-SKL */
1494 }
1495 
1496 /**
1497  * skx_idle_state_table_update - Adjust the Sky Lake/Cascade Lake
1498  * idle states table.
1499  */
1500 static void __init skx_idle_state_table_update(void)
1501 {
1502 	unsigned long long msr;
1503 
1504 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1505 
1506 	/*
1507 	 * 000b: C0/C1 (no package C-state support)
1508 	 * 001b: C2
1509 	 * 010b: C6 (non-retention)
1510 	 * 011b: C6 (retention)
1511 	 * 111b: No Package C state limits.
1512 	 */
1513 	if ((msr & 0x7) < 2) {
1514 		/*
1515 		 * Uses the CC6 + PC0 latency and 3 times of
1516 		 * latency for target_residency if the PC6
1517 		 * is disabled in BIOS. This is consistent
1518 		 * with how intel_idle driver uses _CST
1519 		 * to set the target_residency.
1520 		 */
1521 		skx_cstates[2].exit_latency = 92;
1522 		skx_cstates[2].target_residency = 276;
1523 	}
1524 }
1525 
1526 static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
1527 {
1528 	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
1529 	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
1530 					MWAIT_SUBSTATE_MASK;
1531 
1532 	/* Ignore the C-state if there are NO sub-states in CPUID for it. */
1533 	if (num_substates == 0)
1534 		return false;
1535 
1536 	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1537 		mark_tsc_unstable("TSC halts in idle states deeper than C2");
1538 
1539 	return true;
1540 }
1541 
1542 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
1543 {
1544 	int cstate;
1545 
1546 	switch (boot_cpu_data.x86_model) {
1547 	case INTEL_FAM6_IVYBRIDGE_X:
1548 		ivt_idle_state_table_update();
1549 		break;
1550 	case INTEL_FAM6_ATOM_GOLDMONT:
1551 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1552 		bxt_idle_state_table_update();
1553 		break;
1554 	case INTEL_FAM6_SKYLAKE:
1555 		sklh_idle_state_table_update();
1556 		break;
1557 	case INTEL_FAM6_SKYLAKE_X:
1558 		skx_idle_state_table_update();
1559 		break;
1560 	}
1561 
1562 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1563 		unsigned int mwait_hint;
1564 
1565 		if (intel_idle_max_cstate_reached(cstate))
1566 			break;
1567 
1568 		if (!cpuidle_state_table[cstate].enter &&
1569 		    !cpuidle_state_table[cstate].enter_s2idle)
1570 			break;
1571 
1572 		/* If marked as unusable, skip this state. */
1573 		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
1574 			pr_debug("state %s is disabled\n",
1575 				 cpuidle_state_table[cstate].name);
1576 			continue;
1577 		}
1578 
1579 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1580 		if (!intel_idle_verify_cstate(mwait_hint))
1581 			continue;
1582 
1583 		/* Structure copy. */
1584 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
1585 
1586 		if ((disabled_states_mask & BIT(drv->state_count)) ||
1587 		    ((icpu->use_acpi || force_use_acpi) &&
1588 		     intel_idle_off_by_default(mwait_hint) &&
1589 		     !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE)))
1590 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF;
1591 
1592 		if (intel_idle_state_needs_timer_stop(&drv->states[drv->state_count]))
1593 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_TIMER_STOP;
1594 
1595 		drv->state_count++;
1596 	}
1597 
1598 	if (icpu->byt_auto_demotion_disable_flag) {
1599 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1600 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1601 	}
1602 }
1603 
1604 /**
1605  * intel_idle_cpuidle_driver_init - Create the list of available idle states.
1606  * @drv: cpuidle driver structure to initialize.
1607  */
1608 static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
1609 {
1610 	cpuidle_poll_state_init(drv);
1611 
1612 	if (disabled_states_mask & BIT(0))
1613 		drv->states[0].flags |= CPUIDLE_FLAG_OFF;
1614 
1615 	drv->state_count = 1;
1616 
1617 	if (icpu)
1618 		intel_idle_init_cstates_icpu(drv);
1619 	else
1620 		intel_idle_init_cstates_acpi(drv);
1621 }
1622 
1623 static void auto_demotion_disable(void)
1624 {
1625 	unsigned long long msr_bits;
1626 
1627 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1628 	msr_bits &= ~auto_demotion_disable_flags;
1629 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1630 }
1631 
1632 static void c1e_promotion_disable(void)
1633 {
1634 	unsigned long long msr_bits;
1635 
1636 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
1637 	msr_bits &= ~0x2;
1638 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
1639 }
1640 
1641 /**
1642  * intel_idle_cpu_init - Register the target CPU with the cpuidle core.
1643  * @cpu: CPU to initialize.
1644  *
1645  * Register a cpuidle device object for @cpu and update its MSRs in accordance
1646  * with the processor model flags.
1647  */
1648 static int intel_idle_cpu_init(unsigned int cpu)
1649 {
1650 	struct cpuidle_device *dev;
1651 
1652 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1653 	dev->cpu = cpu;
1654 
1655 	if (cpuidle_register_device(dev)) {
1656 		pr_debug("cpuidle_register_device %d failed!\n", cpu);
1657 		return -EIO;
1658 	}
1659 
1660 	if (auto_demotion_disable_flags)
1661 		auto_demotion_disable();
1662 
1663 	if (disable_promotion_to_c1e)
1664 		c1e_promotion_disable();
1665 
1666 	return 0;
1667 }
1668 
1669 static int intel_idle_cpu_online(unsigned int cpu)
1670 {
1671 	struct cpuidle_device *dev;
1672 
1673 	if (!boot_cpu_has(X86_FEATURE_ARAT))
1674 		tick_broadcast_enable();
1675 
1676 	/*
1677 	 * Some systems can hotplug a cpu at runtime after
1678 	 * the kernel has booted, we have to initialize the
1679 	 * driver in this case
1680 	 */
1681 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1682 	if (!dev->registered)
1683 		return intel_idle_cpu_init(cpu);
1684 
1685 	return 0;
1686 }
1687 
1688 /**
1689  * intel_idle_cpuidle_devices_uninit - Unregister all cpuidle devices.
1690  */
1691 static void __init intel_idle_cpuidle_devices_uninit(void)
1692 {
1693 	int i;
1694 
1695 	for_each_online_cpu(i)
1696 		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
1697 }
1698 
1699 static int __init intel_idle_init(void)
1700 {
1701 	const struct x86_cpu_id *id;
1702 	unsigned int eax, ebx, ecx;
1703 	int retval;
1704 
1705 	/* Do not load intel_idle at all for now if idle= is passed */
1706 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1707 		return -ENODEV;
1708 
1709 	if (max_cstate == 0) {
1710 		pr_debug("disabled\n");
1711 		return -EPERM;
1712 	}
1713 
1714 	id = x86_match_cpu(intel_idle_ids);
1715 	if (id) {
1716 		if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1717 			pr_debug("Please enable MWAIT in BIOS SETUP\n");
1718 			return -ENODEV;
1719 		}
1720 	} else {
1721 		id = x86_match_cpu(intel_mwait_ids);
1722 		if (!id)
1723 			return -ENODEV;
1724 	}
1725 
1726 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1727 		return -ENODEV;
1728 
1729 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1730 
1731 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1732 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1733 	    !mwait_substates)
1734 			return -ENODEV;
1735 
1736 	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1737 
1738 	icpu = (const struct idle_cpu *)id->driver_data;
1739 	if (icpu) {
1740 		cpuidle_state_table = icpu->state_table;
1741 		auto_demotion_disable_flags = icpu->auto_demotion_disable_flags;
1742 		disable_promotion_to_c1e = icpu->disable_promotion_to_c1e;
1743 		if (icpu->use_acpi || force_use_acpi)
1744 			intel_idle_acpi_cst_extract();
1745 	} else if (!intel_idle_acpi_cst_extract()) {
1746 		return -ENODEV;
1747 	}
1748 
1749 	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1750 		 boot_cpu_data.x86_model);
1751 
1752 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1753 	if (!intel_idle_cpuidle_devices)
1754 		return -ENOMEM;
1755 
1756 	intel_idle_cpuidle_driver_init(&intel_idle_driver);
1757 
1758 	retval = cpuidle_register_driver(&intel_idle_driver);
1759 	if (retval) {
1760 		struct cpuidle_driver *drv = cpuidle_get_driver();
1761 		printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1762 		       drv ? drv->name : "none");
1763 		goto init_driver_fail;
1764 	}
1765 
1766 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1767 				   intel_idle_cpu_online, NULL);
1768 	if (retval < 0)
1769 		goto hp_setup_fail;
1770 
1771 	pr_debug("Local APIC timer is reliable in %s\n",
1772 		 boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
1773 
1774 	return 0;
1775 
1776 hp_setup_fail:
1777 	intel_idle_cpuidle_devices_uninit();
1778 	cpuidle_unregister_driver(&intel_idle_driver);
1779 init_driver_fail:
1780 	free_percpu(intel_idle_cpuidle_devices);
1781 	return retval;
1782 
1783 }
1784 device_initcall(intel_idle_init);
1785 
1786 /*
1787  * We are not really modular, but we used to support that.  Meaning we also
1788  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1789  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1790  * is the easiest way (currently) to continue doing that.
1791  */
1792 module_param(max_cstate, int, 0444);
1793 /*
1794  * The positions of the bits that are set in this number are the indices of the
1795  * idle states to be disabled by default (as reflected by the names of the
1796  * corresponding idle state directories in sysfs, "state0", "state1" ...
1797  * "state<i>" ..., where <i> is the index of the given state).
1798  */
1799 module_param_named(states_off, disabled_states_mask, uint, 0444);
1800 MODULE_PARM_DESC(states_off, "Mask of disabled idle states");
1801