xref: /openbmc/linux/drivers/idle/intel_idle.c (revision 15d5761a)
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 specific Intel processors
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-stats
24  */
25 
26 /*
27  * Known limitations
28  *
29  * ACPI has a .suspend hack to turn off deep c-statees during suspend
30  * to avoid complications with the lapic timer workaround.
31  * Have not seen issues with suspend, but may need same workaround here.
32  *
33  */
34 
35 /* un-comment DEBUG to enable pr_debug() statements */
36 #define DEBUG
37 
38 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
39 
40 #include <linux/acpi.h>
41 #include <linux/kernel.h>
42 #include <linux/cpuidle.h>
43 #include <linux/tick.h>
44 #include <trace/events/power.h>
45 #include <linux/sched.h>
46 #include <linux/notifier.h>
47 #include <linux/cpu.h>
48 #include <linux/moduleparam.h>
49 #include <asm/cpu_device_id.h>
50 #include <asm/intel-family.h>
51 #include <asm/mwait.h>
52 #include <asm/msr.h>
53 
54 #define INTEL_IDLE_VERSION "0.5.1"
55 
56 static struct cpuidle_driver intel_idle_driver = {
57 	.name = "intel_idle",
58 	.owner = THIS_MODULE,
59 };
60 /* intel_idle.max_cstate=0 disables driver */
61 static int max_cstate = CPUIDLE_STATE_MAX - 1;
62 static unsigned int disabled_states_mask;
63 
64 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
65 
66 static unsigned long auto_demotion_disable_flags;
67 static bool disable_promotion_to_c1e;
68 
69 static bool lapic_timer_always_reliable;
70 
71 struct idle_cpu {
72 	struct cpuidle_state *state_table;
73 
74 	/*
75 	 * Hardware C-state auto-demotion may not always be optimal.
76 	 * Indicate which enable bits to clear here.
77 	 */
78 	unsigned long auto_demotion_disable_flags;
79 	bool byt_auto_demotion_disable_flag;
80 	bool disable_promotion_to_c1e;
81 	bool use_acpi;
82 };
83 
84 static const struct idle_cpu *icpu __initdata;
85 static struct cpuidle_state *cpuidle_state_table __initdata;
86 
87 static unsigned int mwait_substates __initdata;
88 
89 /*
90  * Enable this state by default even if the ACPI _CST does not list it.
91  */
92 #define CPUIDLE_FLAG_ALWAYS_ENABLE	BIT(15)
93 
94 /*
95  * Set this flag for states where the HW flushes the TLB for us
96  * and so we don't need cross-calls to keep it consistent.
97  * If this flag is set, SW flushes the TLB, so even if the
98  * HW doesn't do the flushing, this flag is safe to use.
99  */
100 #define CPUIDLE_FLAG_TLB_FLUSHED	BIT(16)
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 	bool uninitialized_var(tick);
136 	int cpu = smp_processor_id();
137 
138 	/*
139 	 * leave_mm() to avoid costly and often unnecessary wakeups
140 	 * for flushing the user TLB's associated with the active mm.
141 	 */
142 	if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
143 		leave_mm(cpu);
144 
145 	if (!static_cpu_has(X86_FEATURE_ARAT) && !lapic_timer_always_reliable) {
146 		/*
147 		 * Switch over to one-shot tick broadcast if the target C-state
148 		 * is deeper than C1.
149 		 */
150 		if ((eax >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) {
151 			tick = true;
152 			tick_broadcast_enter();
153 		} else {
154 			tick = false;
155 		}
156 	}
157 
158 	mwait_idle_with_hints(eax, ecx);
159 
160 	if (!static_cpu_has(X86_FEATURE_ARAT) && tick)
161 		tick_broadcast_exit();
162 
163 	return index;
164 }
165 
166 /**
167  * intel_idle_s2idle - Ask the processor to enter the given idle state.
168  * @dev: cpuidle device of the target CPU.
169  * @drv: cpuidle driver (assumed to point to intel_idle_driver).
170  * @index: Target idle state index.
171  *
172  * Use the MWAIT instruction to notify the processor that the CPU represented by
173  * @dev is idle and it can try to enter the idle state corresponding to @index.
174  *
175  * Invoked as a suspend-to-idle callback routine with frozen user space, frozen
176  * scheduler tick and suspended scheduler clock on the target CPU.
177  */
178 static __cpuidle void intel_idle_s2idle(struct cpuidle_device *dev,
179 					struct cpuidle_driver *drv, int index)
180 {
181 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
182 	unsigned long ecx = 1; /* break on interrupt flag */
183 
184 	mwait_idle_with_hints(eax, ecx);
185 }
186 
187 /*
188  * States are indexed by the cstate number,
189  * which is also the index into the MWAIT hint array.
190  * Thus C0 is a dummy.
191  */
192 static struct cpuidle_state nehalem_cstates[] __initdata = {
193 	{
194 		.name = "C1",
195 		.desc = "MWAIT 0x00",
196 		.flags = MWAIT2flg(0x00),
197 		.exit_latency = 3,
198 		.target_residency = 6,
199 		.enter = &intel_idle,
200 		.enter_s2idle = intel_idle_s2idle, },
201 	{
202 		.name = "C1E",
203 		.desc = "MWAIT 0x01",
204 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
205 		.exit_latency = 10,
206 		.target_residency = 20,
207 		.enter = &intel_idle,
208 		.enter_s2idle = intel_idle_s2idle, },
209 	{
210 		.name = "C3",
211 		.desc = "MWAIT 0x10",
212 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
213 		.exit_latency = 20,
214 		.target_residency = 80,
215 		.enter = &intel_idle,
216 		.enter_s2idle = intel_idle_s2idle, },
217 	{
218 		.name = "C6",
219 		.desc = "MWAIT 0x20",
220 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
221 		.exit_latency = 200,
222 		.target_residency = 800,
223 		.enter = &intel_idle,
224 		.enter_s2idle = intel_idle_s2idle, },
225 	{
226 		.enter = NULL }
227 };
228 
229 static struct cpuidle_state snb_cstates[] __initdata = {
230 	{
231 		.name = "C1",
232 		.desc = "MWAIT 0x00",
233 		.flags = MWAIT2flg(0x00),
234 		.exit_latency = 2,
235 		.target_residency = 2,
236 		.enter = &intel_idle,
237 		.enter_s2idle = intel_idle_s2idle, },
238 	{
239 		.name = "C1E",
240 		.desc = "MWAIT 0x01",
241 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
242 		.exit_latency = 10,
243 		.target_residency = 20,
244 		.enter = &intel_idle,
245 		.enter_s2idle = intel_idle_s2idle, },
246 	{
247 		.name = "C3",
248 		.desc = "MWAIT 0x10",
249 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
250 		.exit_latency = 80,
251 		.target_residency = 211,
252 		.enter = &intel_idle,
253 		.enter_s2idle = intel_idle_s2idle, },
254 	{
255 		.name = "C6",
256 		.desc = "MWAIT 0x20",
257 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
258 		.exit_latency = 104,
259 		.target_residency = 345,
260 		.enter = &intel_idle,
261 		.enter_s2idle = intel_idle_s2idle, },
262 	{
263 		.name = "C7",
264 		.desc = "MWAIT 0x30",
265 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
266 		.exit_latency = 109,
267 		.target_residency = 345,
268 		.enter = &intel_idle,
269 		.enter_s2idle = intel_idle_s2idle, },
270 	{
271 		.enter = NULL }
272 };
273 
274 static struct cpuidle_state byt_cstates[] __initdata = {
275 	{
276 		.name = "C1",
277 		.desc = "MWAIT 0x00",
278 		.flags = MWAIT2flg(0x00),
279 		.exit_latency = 1,
280 		.target_residency = 1,
281 		.enter = &intel_idle,
282 		.enter_s2idle = intel_idle_s2idle, },
283 	{
284 		.name = "C6N",
285 		.desc = "MWAIT 0x58",
286 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
287 		.exit_latency = 300,
288 		.target_residency = 275,
289 		.enter = &intel_idle,
290 		.enter_s2idle = intel_idle_s2idle, },
291 	{
292 		.name = "C6S",
293 		.desc = "MWAIT 0x52",
294 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
295 		.exit_latency = 500,
296 		.target_residency = 560,
297 		.enter = &intel_idle,
298 		.enter_s2idle = intel_idle_s2idle, },
299 	{
300 		.name = "C7",
301 		.desc = "MWAIT 0x60",
302 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
303 		.exit_latency = 1200,
304 		.target_residency = 4000,
305 		.enter = &intel_idle,
306 		.enter_s2idle = intel_idle_s2idle, },
307 	{
308 		.name = "C7S",
309 		.desc = "MWAIT 0x64",
310 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
311 		.exit_latency = 10000,
312 		.target_residency = 20000,
313 		.enter = &intel_idle,
314 		.enter_s2idle = intel_idle_s2idle, },
315 	{
316 		.enter = NULL }
317 };
318 
319 static struct cpuidle_state cht_cstates[] __initdata = {
320 	{
321 		.name = "C1",
322 		.desc = "MWAIT 0x00",
323 		.flags = MWAIT2flg(0x00),
324 		.exit_latency = 1,
325 		.target_residency = 1,
326 		.enter = &intel_idle,
327 		.enter_s2idle = intel_idle_s2idle, },
328 	{
329 		.name = "C6N",
330 		.desc = "MWAIT 0x58",
331 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
332 		.exit_latency = 80,
333 		.target_residency = 275,
334 		.enter = &intel_idle,
335 		.enter_s2idle = intel_idle_s2idle, },
336 	{
337 		.name = "C6S",
338 		.desc = "MWAIT 0x52",
339 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
340 		.exit_latency = 200,
341 		.target_residency = 560,
342 		.enter = &intel_idle,
343 		.enter_s2idle = intel_idle_s2idle, },
344 	{
345 		.name = "C7",
346 		.desc = "MWAIT 0x60",
347 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
348 		.exit_latency = 1200,
349 		.target_residency = 4000,
350 		.enter = &intel_idle,
351 		.enter_s2idle = intel_idle_s2idle, },
352 	{
353 		.name = "C7S",
354 		.desc = "MWAIT 0x64",
355 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
356 		.exit_latency = 10000,
357 		.target_residency = 20000,
358 		.enter = &intel_idle,
359 		.enter_s2idle = intel_idle_s2idle, },
360 	{
361 		.enter = NULL }
362 };
363 
364 static struct cpuidle_state ivb_cstates[] __initdata = {
365 	{
366 		.name = "C1",
367 		.desc = "MWAIT 0x00",
368 		.flags = MWAIT2flg(0x00),
369 		.exit_latency = 1,
370 		.target_residency = 1,
371 		.enter = &intel_idle,
372 		.enter_s2idle = intel_idle_s2idle, },
373 	{
374 		.name = "C1E",
375 		.desc = "MWAIT 0x01",
376 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
377 		.exit_latency = 10,
378 		.target_residency = 20,
379 		.enter = &intel_idle,
380 		.enter_s2idle = intel_idle_s2idle, },
381 	{
382 		.name = "C3",
383 		.desc = "MWAIT 0x10",
384 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
385 		.exit_latency = 59,
386 		.target_residency = 156,
387 		.enter = &intel_idle,
388 		.enter_s2idle = intel_idle_s2idle, },
389 	{
390 		.name = "C6",
391 		.desc = "MWAIT 0x20",
392 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
393 		.exit_latency = 80,
394 		.target_residency = 300,
395 		.enter = &intel_idle,
396 		.enter_s2idle = intel_idle_s2idle, },
397 	{
398 		.name = "C7",
399 		.desc = "MWAIT 0x30",
400 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
401 		.exit_latency = 87,
402 		.target_residency = 300,
403 		.enter = &intel_idle,
404 		.enter_s2idle = intel_idle_s2idle, },
405 	{
406 		.enter = NULL }
407 };
408 
409 static struct cpuidle_state ivt_cstates[] __initdata = {
410 	{
411 		.name = "C1",
412 		.desc = "MWAIT 0x00",
413 		.flags = MWAIT2flg(0x00),
414 		.exit_latency = 1,
415 		.target_residency = 1,
416 		.enter = &intel_idle,
417 		.enter_s2idle = intel_idle_s2idle, },
418 	{
419 		.name = "C1E",
420 		.desc = "MWAIT 0x01",
421 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
422 		.exit_latency = 10,
423 		.target_residency = 80,
424 		.enter = &intel_idle,
425 		.enter_s2idle = intel_idle_s2idle, },
426 	{
427 		.name = "C3",
428 		.desc = "MWAIT 0x10",
429 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
430 		.exit_latency = 59,
431 		.target_residency = 156,
432 		.enter = &intel_idle,
433 		.enter_s2idle = intel_idle_s2idle, },
434 	{
435 		.name = "C6",
436 		.desc = "MWAIT 0x20",
437 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
438 		.exit_latency = 82,
439 		.target_residency = 300,
440 		.enter = &intel_idle,
441 		.enter_s2idle = intel_idle_s2idle, },
442 	{
443 		.enter = NULL }
444 };
445 
446 static struct cpuidle_state ivt_cstates_4s[] __initdata = {
447 	{
448 		.name = "C1",
449 		.desc = "MWAIT 0x00",
450 		.flags = MWAIT2flg(0x00),
451 		.exit_latency = 1,
452 		.target_residency = 1,
453 		.enter = &intel_idle,
454 		.enter_s2idle = intel_idle_s2idle, },
455 	{
456 		.name = "C1E",
457 		.desc = "MWAIT 0x01",
458 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
459 		.exit_latency = 10,
460 		.target_residency = 250,
461 		.enter = &intel_idle,
462 		.enter_s2idle = intel_idle_s2idle, },
463 	{
464 		.name = "C3",
465 		.desc = "MWAIT 0x10",
466 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
467 		.exit_latency = 59,
468 		.target_residency = 300,
469 		.enter = &intel_idle,
470 		.enter_s2idle = intel_idle_s2idle, },
471 	{
472 		.name = "C6",
473 		.desc = "MWAIT 0x20",
474 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
475 		.exit_latency = 84,
476 		.target_residency = 400,
477 		.enter = &intel_idle,
478 		.enter_s2idle = intel_idle_s2idle, },
479 	{
480 		.enter = NULL }
481 };
482 
483 static struct cpuidle_state ivt_cstates_8s[] __initdata = {
484 	{
485 		.name = "C1",
486 		.desc = "MWAIT 0x00",
487 		.flags = MWAIT2flg(0x00),
488 		.exit_latency = 1,
489 		.target_residency = 1,
490 		.enter = &intel_idle,
491 		.enter_s2idle = intel_idle_s2idle, },
492 	{
493 		.name = "C1E",
494 		.desc = "MWAIT 0x01",
495 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
496 		.exit_latency = 10,
497 		.target_residency = 500,
498 		.enter = &intel_idle,
499 		.enter_s2idle = intel_idle_s2idle, },
500 	{
501 		.name = "C3",
502 		.desc = "MWAIT 0x10",
503 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
504 		.exit_latency = 59,
505 		.target_residency = 600,
506 		.enter = &intel_idle,
507 		.enter_s2idle = intel_idle_s2idle, },
508 	{
509 		.name = "C6",
510 		.desc = "MWAIT 0x20",
511 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
512 		.exit_latency = 88,
513 		.target_residency = 700,
514 		.enter = &intel_idle,
515 		.enter_s2idle = intel_idle_s2idle, },
516 	{
517 		.enter = NULL }
518 };
519 
520 static struct cpuidle_state hsw_cstates[] __initdata = {
521 	{
522 		.name = "C1",
523 		.desc = "MWAIT 0x00",
524 		.flags = MWAIT2flg(0x00),
525 		.exit_latency = 2,
526 		.target_residency = 2,
527 		.enter = &intel_idle,
528 		.enter_s2idle = intel_idle_s2idle, },
529 	{
530 		.name = "C1E",
531 		.desc = "MWAIT 0x01",
532 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
533 		.exit_latency = 10,
534 		.target_residency = 20,
535 		.enter = &intel_idle,
536 		.enter_s2idle = intel_idle_s2idle, },
537 	{
538 		.name = "C3",
539 		.desc = "MWAIT 0x10",
540 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
541 		.exit_latency = 33,
542 		.target_residency = 100,
543 		.enter = &intel_idle,
544 		.enter_s2idle = intel_idle_s2idle, },
545 	{
546 		.name = "C6",
547 		.desc = "MWAIT 0x20",
548 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
549 		.exit_latency = 133,
550 		.target_residency = 400,
551 		.enter = &intel_idle,
552 		.enter_s2idle = intel_idle_s2idle, },
553 	{
554 		.name = "C7s",
555 		.desc = "MWAIT 0x32",
556 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
557 		.exit_latency = 166,
558 		.target_residency = 500,
559 		.enter = &intel_idle,
560 		.enter_s2idle = intel_idle_s2idle, },
561 	{
562 		.name = "C8",
563 		.desc = "MWAIT 0x40",
564 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
565 		.exit_latency = 300,
566 		.target_residency = 900,
567 		.enter = &intel_idle,
568 		.enter_s2idle = intel_idle_s2idle, },
569 	{
570 		.name = "C9",
571 		.desc = "MWAIT 0x50",
572 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
573 		.exit_latency = 600,
574 		.target_residency = 1800,
575 		.enter = &intel_idle,
576 		.enter_s2idle = intel_idle_s2idle, },
577 	{
578 		.name = "C10",
579 		.desc = "MWAIT 0x60",
580 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
581 		.exit_latency = 2600,
582 		.target_residency = 7700,
583 		.enter = &intel_idle,
584 		.enter_s2idle = intel_idle_s2idle, },
585 	{
586 		.enter = NULL }
587 };
588 static struct cpuidle_state bdw_cstates[] __initdata = {
589 	{
590 		.name = "C1",
591 		.desc = "MWAIT 0x00",
592 		.flags = MWAIT2flg(0x00),
593 		.exit_latency = 2,
594 		.target_residency = 2,
595 		.enter = &intel_idle,
596 		.enter_s2idle = intel_idle_s2idle, },
597 	{
598 		.name = "C1E",
599 		.desc = "MWAIT 0x01",
600 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
601 		.exit_latency = 10,
602 		.target_residency = 20,
603 		.enter = &intel_idle,
604 		.enter_s2idle = intel_idle_s2idle, },
605 	{
606 		.name = "C3",
607 		.desc = "MWAIT 0x10",
608 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
609 		.exit_latency = 40,
610 		.target_residency = 100,
611 		.enter = &intel_idle,
612 		.enter_s2idle = intel_idle_s2idle, },
613 	{
614 		.name = "C6",
615 		.desc = "MWAIT 0x20",
616 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
617 		.exit_latency = 133,
618 		.target_residency = 400,
619 		.enter = &intel_idle,
620 		.enter_s2idle = intel_idle_s2idle, },
621 	{
622 		.name = "C7s",
623 		.desc = "MWAIT 0x32",
624 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
625 		.exit_latency = 166,
626 		.target_residency = 500,
627 		.enter = &intel_idle,
628 		.enter_s2idle = intel_idle_s2idle, },
629 	{
630 		.name = "C8",
631 		.desc = "MWAIT 0x40",
632 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
633 		.exit_latency = 300,
634 		.target_residency = 900,
635 		.enter = &intel_idle,
636 		.enter_s2idle = intel_idle_s2idle, },
637 	{
638 		.name = "C9",
639 		.desc = "MWAIT 0x50",
640 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
641 		.exit_latency = 600,
642 		.target_residency = 1800,
643 		.enter = &intel_idle,
644 		.enter_s2idle = intel_idle_s2idle, },
645 	{
646 		.name = "C10",
647 		.desc = "MWAIT 0x60",
648 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
649 		.exit_latency = 2600,
650 		.target_residency = 7700,
651 		.enter = &intel_idle,
652 		.enter_s2idle = intel_idle_s2idle, },
653 	{
654 		.enter = NULL }
655 };
656 
657 static struct cpuidle_state skl_cstates[] __initdata = {
658 	{
659 		.name = "C1",
660 		.desc = "MWAIT 0x00",
661 		.flags = MWAIT2flg(0x00),
662 		.exit_latency = 2,
663 		.target_residency = 2,
664 		.enter = &intel_idle,
665 		.enter_s2idle = intel_idle_s2idle, },
666 	{
667 		.name = "C1E",
668 		.desc = "MWAIT 0x01",
669 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
670 		.exit_latency = 10,
671 		.target_residency = 20,
672 		.enter = &intel_idle,
673 		.enter_s2idle = intel_idle_s2idle, },
674 	{
675 		.name = "C3",
676 		.desc = "MWAIT 0x10",
677 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
678 		.exit_latency = 70,
679 		.target_residency = 100,
680 		.enter = &intel_idle,
681 		.enter_s2idle = intel_idle_s2idle, },
682 	{
683 		.name = "C6",
684 		.desc = "MWAIT 0x20",
685 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
686 		.exit_latency = 85,
687 		.target_residency = 200,
688 		.enter = &intel_idle,
689 		.enter_s2idle = intel_idle_s2idle, },
690 	{
691 		.name = "C7s",
692 		.desc = "MWAIT 0x33",
693 		.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
694 		.exit_latency = 124,
695 		.target_residency = 800,
696 		.enter = &intel_idle,
697 		.enter_s2idle = intel_idle_s2idle, },
698 	{
699 		.name = "C8",
700 		.desc = "MWAIT 0x40",
701 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
702 		.exit_latency = 200,
703 		.target_residency = 800,
704 		.enter = &intel_idle,
705 		.enter_s2idle = intel_idle_s2idle, },
706 	{
707 		.name = "C9",
708 		.desc = "MWAIT 0x50",
709 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
710 		.exit_latency = 480,
711 		.target_residency = 5000,
712 		.enter = &intel_idle,
713 		.enter_s2idle = intel_idle_s2idle, },
714 	{
715 		.name = "C10",
716 		.desc = "MWAIT 0x60",
717 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
718 		.exit_latency = 890,
719 		.target_residency = 5000,
720 		.enter = &intel_idle,
721 		.enter_s2idle = intel_idle_s2idle, },
722 	{
723 		.enter = NULL }
724 };
725 
726 static struct cpuidle_state skx_cstates[] __initdata = {
727 	{
728 		.name = "C1",
729 		.desc = "MWAIT 0x00",
730 		.flags = MWAIT2flg(0x00),
731 		.exit_latency = 2,
732 		.target_residency = 2,
733 		.enter = &intel_idle,
734 		.enter_s2idle = intel_idle_s2idle, },
735 	{
736 		.name = "C1E",
737 		.desc = "MWAIT 0x01",
738 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
739 		.exit_latency = 10,
740 		.target_residency = 20,
741 		.enter = &intel_idle,
742 		.enter_s2idle = intel_idle_s2idle, },
743 	{
744 		.name = "C6",
745 		.desc = "MWAIT 0x20",
746 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
747 		.exit_latency = 133,
748 		.target_residency = 600,
749 		.enter = &intel_idle,
750 		.enter_s2idle = intel_idle_s2idle, },
751 	{
752 		.enter = NULL }
753 };
754 
755 static struct cpuidle_state atom_cstates[] __initdata = {
756 	{
757 		.name = "C1E",
758 		.desc = "MWAIT 0x00",
759 		.flags = MWAIT2flg(0x00),
760 		.exit_latency = 10,
761 		.target_residency = 20,
762 		.enter = &intel_idle,
763 		.enter_s2idle = intel_idle_s2idle, },
764 	{
765 		.name = "C2",
766 		.desc = "MWAIT 0x10",
767 		.flags = MWAIT2flg(0x10),
768 		.exit_latency = 20,
769 		.target_residency = 80,
770 		.enter = &intel_idle,
771 		.enter_s2idle = intel_idle_s2idle, },
772 	{
773 		.name = "C4",
774 		.desc = "MWAIT 0x30",
775 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
776 		.exit_latency = 100,
777 		.target_residency = 400,
778 		.enter = &intel_idle,
779 		.enter_s2idle = intel_idle_s2idle, },
780 	{
781 		.name = "C6",
782 		.desc = "MWAIT 0x52",
783 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
784 		.exit_latency = 140,
785 		.target_residency = 560,
786 		.enter = &intel_idle,
787 		.enter_s2idle = intel_idle_s2idle, },
788 	{
789 		.enter = NULL }
790 };
791 static struct cpuidle_state tangier_cstates[] __initdata = {
792 	{
793 		.name = "C1",
794 		.desc = "MWAIT 0x00",
795 		.flags = MWAIT2flg(0x00),
796 		.exit_latency = 1,
797 		.target_residency = 4,
798 		.enter = &intel_idle,
799 		.enter_s2idle = intel_idle_s2idle, },
800 	{
801 		.name = "C4",
802 		.desc = "MWAIT 0x30",
803 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
804 		.exit_latency = 100,
805 		.target_residency = 400,
806 		.enter = &intel_idle,
807 		.enter_s2idle = intel_idle_s2idle, },
808 	{
809 		.name = "C6",
810 		.desc = "MWAIT 0x52",
811 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
812 		.exit_latency = 140,
813 		.target_residency = 560,
814 		.enter = &intel_idle,
815 		.enter_s2idle = intel_idle_s2idle, },
816 	{
817 		.name = "C7",
818 		.desc = "MWAIT 0x60",
819 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
820 		.exit_latency = 1200,
821 		.target_residency = 4000,
822 		.enter = &intel_idle,
823 		.enter_s2idle = intel_idle_s2idle, },
824 	{
825 		.name = "C9",
826 		.desc = "MWAIT 0x64",
827 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
828 		.exit_latency = 10000,
829 		.target_residency = 20000,
830 		.enter = &intel_idle,
831 		.enter_s2idle = intel_idle_s2idle, },
832 	{
833 		.enter = NULL }
834 };
835 static struct cpuidle_state avn_cstates[] __initdata = {
836 	{
837 		.name = "C1",
838 		.desc = "MWAIT 0x00",
839 		.flags = MWAIT2flg(0x00),
840 		.exit_latency = 2,
841 		.target_residency = 2,
842 		.enter = &intel_idle,
843 		.enter_s2idle = intel_idle_s2idle, },
844 	{
845 		.name = "C6",
846 		.desc = "MWAIT 0x51",
847 		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
848 		.exit_latency = 15,
849 		.target_residency = 45,
850 		.enter = &intel_idle,
851 		.enter_s2idle = intel_idle_s2idle, },
852 	{
853 		.enter = NULL }
854 };
855 static struct cpuidle_state knl_cstates[] __initdata = {
856 	{
857 		.name = "C1",
858 		.desc = "MWAIT 0x00",
859 		.flags = MWAIT2flg(0x00),
860 		.exit_latency = 1,
861 		.target_residency = 2,
862 		.enter = &intel_idle,
863 		.enter_s2idle = intel_idle_s2idle },
864 	{
865 		.name = "C6",
866 		.desc = "MWAIT 0x10",
867 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
868 		.exit_latency = 120,
869 		.target_residency = 500,
870 		.enter = &intel_idle,
871 		.enter_s2idle = intel_idle_s2idle },
872 	{
873 		.enter = NULL }
874 };
875 
876 static struct cpuidle_state bxt_cstates[] __initdata = {
877 	{
878 		.name = "C1",
879 		.desc = "MWAIT 0x00",
880 		.flags = MWAIT2flg(0x00),
881 		.exit_latency = 2,
882 		.target_residency = 2,
883 		.enter = &intel_idle,
884 		.enter_s2idle = intel_idle_s2idle, },
885 	{
886 		.name = "C1E",
887 		.desc = "MWAIT 0x01",
888 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
889 		.exit_latency = 10,
890 		.target_residency = 20,
891 		.enter = &intel_idle,
892 		.enter_s2idle = intel_idle_s2idle, },
893 	{
894 		.name = "C6",
895 		.desc = "MWAIT 0x20",
896 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
897 		.exit_latency = 133,
898 		.target_residency = 133,
899 		.enter = &intel_idle,
900 		.enter_s2idle = intel_idle_s2idle, },
901 	{
902 		.name = "C7s",
903 		.desc = "MWAIT 0x31",
904 		.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
905 		.exit_latency = 155,
906 		.target_residency = 155,
907 		.enter = &intel_idle,
908 		.enter_s2idle = intel_idle_s2idle, },
909 	{
910 		.name = "C8",
911 		.desc = "MWAIT 0x40",
912 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
913 		.exit_latency = 1000,
914 		.target_residency = 1000,
915 		.enter = &intel_idle,
916 		.enter_s2idle = intel_idle_s2idle, },
917 	{
918 		.name = "C9",
919 		.desc = "MWAIT 0x50",
920 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
921 		.exit_latency = 2000,
922 		.target_residency = 2000,
923 		.enter = &intel_idle,
924 		.enter_s2idle = intel_idle_s2idle, },
925 	{
926 		.name = "C10",
927 		.desc = "MWAIT 0x60",
928 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
929 		.exit_latency = 10000,
930 		.target_residency = 10000,
931 		.enter = &intel_idle,
932 		.enter_s2idle = intel_idle_s2idle, },
933 	{
934 		.enter = NULL }
935 };
936 
937 static struct cpuidle_state dnv_cstates[] __initdata = {
938 	{
939 		.name = "C1",
940 		.desc = "MWAIT 0x00",
941 		.flags = MWAIT2flg(0x00),
942 		.exit_latency = 2,
943 		.target_residency = 2,
944 		.enter = &intel_idle,
945 		.enter_s2idle = intel_idle_s2idle, },
946 	{
947 		.name = "C1E",
948 		.desc = "MWAIT 0x01",
949 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
950 		.exit_latency = 10,
951 		.target_residency = 20,
952 		.enter = &intel_idle,
953 		.enter_s2idle = intel_idle_s2idle, },
954 	{
955 		.name = "C6",
956 		.desc = "MWAIT 0x20",
957 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
958 		.exit_latency = 50,
959 		.target_residency = 500,
960 		.enter = &intel_idle,
961 		.enter_s2idle = intel_idle_s2idle, },
962 	{
963 		.enter = NULL }
964 };
965 
966 static const struct idle_cpu idle_cpu_nehalem __initconst = {
967 	.state_table = nehalem_cstates,
968 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
969 	.disable_promotion_to_c1e = true,
970 };
971 
972 static const struct idle_cpu idle_cpu_nhx __initconst = {
973 	.state_table = nehalem_cstates,
974 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
975 	.disable_promotion_to_c1e = true,
976 	.use_acpi = true,
977 };
978 
979 static const struct idle_cpu idle_cpu_atom __initconst = {
980 	.state_table = atom_cstates,
981 };
982 
983 static const struct idle_cpu idle_cpu_tangier __initconst = {
984 	.state_table = tangier_cstates,
985 };
986 
987 static const struct idle_cpu idle_cpu_lincroft __initconst = {
988 	.state_table = atom_cstates,
989 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
990 };
991 
992 static const struct idle_cpu idle_cpu_snb __initconst = {
993 	.state_table = snb_cstates,
994 	.disable_promotion_to_c1e = true,
995 };
996 
997 static const struct idle_cpu idle_cpu_snx __initconst = {
998 	.state_table = snb_cstates,
999 	.disable_promotion_to_c1e = true,
1000 	.use_acpi = true,
1001 };
1002 
1003 static const struct idle_cpu idle_cpu_byt __initconst = {
1004 	.state_table = byt_cstates,
1005 	.disable_promotion_to_c1e = true,
1006 	.byt_auto_demotion_disable_flag = true,
1007 };
1008 
1009 static const struct idle_cpu idle_cpu_cht __initconst = {
1010 	.state_table = cht_cstates,
1011 	.disable_promotion_to_c1e = true,
1012 	.byt_auto_demotion_disable_flag = true,
1013 };
1014 
1015 static const struct idle_cpu idle_cpu_ivb __initconst = {
1016 	.state_table = ivb_cstates,
1017 	.disable_promotion_to_c1e = true,
1018 };
1019 
1020 static const struct idle_cpu idle_cpu_ivt __initconst = {
1021 	.state_table = ivt_cstates,
1022 	.disable_promotion_to_c1e = true,
1023 	.use_acpi = true,
1024 };
1025 
1026 static const struct idle_cpu idle_cpu_hsw __initconst = {
1027 	.state_table = hsw_cstates,
1028 	.disable_promotion_to_c1e = true,
1029 };
1030 
1031 static const struct idle_cpu idle_cpu_hsx __initconst = {
1032 	.state_table = hsw_cstates,
1033 	.disable_promotion_to_c1e = true,
1034 	.use_acpi = true,
1035 };
1036 
1037 static const struct idle_cpu idle_cpu_bdw __initconst = {
1038 	.state_table = bdw_cstates,
1039 	.disable_promotion_to_c1e = true,
1040 };
1041 
1042 static const struct idle_cpu idle_cpu_bdx __initconst = {
1043 	.state_table = bdw_cstates,
1044 	.disable_promotion_to_c1e = true,
1045 	.use_acpi = true,
1046 };
1047 
1048 static const struct idle_cpu idle_cpu_skl __initconst = {
1049 	.state_table = skl_cstates,
1050 	.disable_promotion_to_c1e = true,
1051 };
1052 
1053 static const struct idle_cpu idle_cpu_skx __initconst = {
1054 	.state_table = skx_cstates,
1055 	.disable_promotion_to_c1e = true,
1056 	.use_acpi = true,
1057 };
1058 
1059 static const struct idle_cpu idle_cpu_avn __initconst = {
1060 	.state_table = avn_cstates,
1061 	.disable_promotion_to_c1e = true,
1062 	.use_acpi = true,
1063 };
1064 
1065 static const struct idle_cpu idle_cpu_knl __initconst = {
1066 	.state_table = knl_cstates,
1067 	.use_acpi = true,
1068 };
1069 
1070 static const struct idle_cpu idle_cpu_bxt __initconst = {
1071 	.state_table = bxt_cstates,
1072 	.disable_promotion_to_c1e = true,
1073 };
1074 
1075 static const struct idle_cpu idle_cpu_dnv __initconst = {
1076 	.state_table = dnv_cstates,
1077 	.disable_promotion_to_c1e = true,
1078 	.use_acpi = true,
1079 };
1080 
1081 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1082 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EP,		&idle_cpu_nhx),
1083 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM,		&idle_cpu_nehalem),
1084 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_G,		&idle_cpu_nehalem),
1085 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE,		&idle_cpu_nehalem),
1086 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EP,		&idle_cpu_nhx),
1087 	X86_MATCH_INTEL_FAM6_MODEL(NEHALEM_EX,		&idle_cpu_nhx),
1088 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL,	&idle_cpu_atom),
1089 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_BONNELL_MID,	&idle_cpu_lincroft),
1090 	X86_MATCH_INTEL_FAM6_MODEL(WESTMERE_EX,		&idle_cpu_nhx),
1091 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE,		&idle_cpu_snb),
1092 	X86_MATCH_INTEL_FAM6_MODEL(SANDYBRIDGE_X,	&idle_cpu_snx),
1093 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SALTWELL,	&idle_cpu_atom),
1094 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	&idle_cpu_byt),
1095 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID,	&idle_cpu_tangier),
1096 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	&idle_cpu_cht),
1097 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE,		&idle_cpu_ivb),
1098 	X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE_X,		&idle_cpu_ivt),
1099 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL,		&idle_cpu_hsw),
1100 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X,		&idle_cpu_hsx),
1101 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_L,		&idle_cpu_hsw),
1102 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_G,		&idle_cpu_hsw),
1103 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_D,	&idle_cpu_avn),
1104 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL,		&idle_cpu_bdw),
1105 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_G,		&idle_cpu_bdw),
1106 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X,		&idle_cpu_bdx),
1107 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_D,		&idle_cpu_bdx),
1108 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		&idle_cpu_skl),
1109 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		&idle_cpu_skl),
1110 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		&idle_cpu_skl),
1111 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		&idle_cpu_skl),
1112 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X,		&idle_cpu_skx),
1113 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL,	&idle_cpu_knl),
1114 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM,	&idle_cpu_knl),
1115 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	&idle_cpu_bxt),
1116 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_PLUS,	&idle_cpu_bxt),
1117 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D,	&idle_cpu_dnv),
1118 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	&idle_cpu_dnv),
1119 	{}
1120 };
1121 
1122 static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
1123 	X86_MATCH_VENDOR_FAM_FEATURE(INTEL, 6, X86_FEATURE_MWAIT, NULL),
1124 	{}
1125 };
1126 
1127 static bool __init intel_idle_max_cstate_reached(int cstate)
1128 {
1129 	if (cstate + 1 > max_cstate) {
1130 		pr_info("max_cstate %d reached\n", max_cstate);
1131 		return true;
1132 	}
1133 	return false;
1134 }
1135 
1136 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
1137 #include <acpi/processor.h>
1138 
1139 static bool no_acpi __read_mostly;
1140 module_param(no_acpi, bool, 0444);
1141 MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list");
1142 
1143 static bool force_use_acpi __read_mostly; /* No effect if no_acpi is set. */
1144 module_param_named(use_acpi, force_use_acpi, bool, 0444);
1145 MODULE_PARM_DESC(use_acpi, "Use ACPI _CST for building the idle states list");
1146 
1147 static struct acpi_processor_power acpi_state_table __initdata;
1148 
1149 /**
1150  * intel_idle_cst_usable - Check if the _CST information can be used.
1151  *
1152  * Check if all of the C-states listed by _CST in the max_cstate range are
1153  * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
1154  */
1155 static bool __init intel_idle_cst_usable(void)
1156 {
1157 	int cstate, limit;
1158 
1159 	limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
1160 		      acpi_state_table.count);
1161 
1162 	for (cstate = 1; cstate < limit; cstate++) {
1163 		struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
1164 
1165 		if (cx->entry_method != ACPI_CSTATE_FFH)
1166 			return false;
1167 	}
1168 
1169 	return true;
1170 }
1171 
1172 static bool __init intel_idle_acpi_cst_extract(void)
1173 {
1174 	unsigned int cpu;
1175 
1176 	if (no_acpi) {
1177 		pr_debug("Not allowed to use ACPI _CST\n");
1178 		return false;
1179 	}
1180 
1181 	for_each_possible_cpu(cpu) {
1182 		struct acpi_processor *pr = per_cpu(processors, cpu);
1183 
1184 		if (!pr)
1185 			continue;
1186 
1187 		if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
1188 			continue;
1189 
1190 		acpi_state_table.count++;
1191 
1192 		if (!intel_idle_cst_usable())
1193 			continue;
1194 
1195 		if (!acpi_processor_claim_cst_control()) {
1196 			acpi_state_table.count = 0;
1197 			return false;
1198 		}
1199 
1200 		return true;
1201 	}
1202 
1203 	pr_debug("ACPI _CST not found or not usable\n");
1204 	return false;
1205 }
1206 
1207 static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
1208 {
1209 	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1210 
1211 	/*
1212 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1213 	 * the interesting states are ACPI_CSTATE_FFH.
1214 	 */
1215 	for (cstate = 1; cstate < limit; cstate++) {
1216 		struct acpi_processor_cx *cx;
1217 		struct cpuidle_state *state;
1218 
1219 		if (intel_idle_max_cstate_reached(cstate))
1220 			break;
1221 
1222 		cx = &acpi_state_table.states[cstate];
1223 
1224 		state = &drv->states[drv->state_count++];
1225 
1226 		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
1227 		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1228 		state->exit_latency = cx->latency;
1229 		/*
1230 		 * For C1-type C-states use the same number for both the exit
1231 		 * latency and target residency, because that is the case for
1232 		 * C1 in the majority of the static C-states tables above.
1233 		 * For the other types of C-states, however, set the target
1234 		 * residency to 3 times the exit latency which should lead to
1235 		 * a reasonable balance between energy-efficiency and
1236 		 * performance in the majority of interesting cases.
1237 		 */
1238 		state->target_residency = cx->latency;
1239 		if (cx->type > ACPI_STATE_C1)
1240 			state->target_residency *= 3;
1241 
1242 		state->flags = MWAIT2flg(cx->address);
1243 		if (cx->type > ACPI_STATE_C2)
1244 			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
1245 
1246 		if (disabled_states_mask & BIT(cstate))
1247 			state->flags |= CPUIDLE_FLAG_OFF;
1248 
1249 		state->enter = intel_idle;
1250 		state->enter_s2idle = intel_idle_s2idle;
1251 	}
1252 }
1253 
1254 static bool __init intel_idle_off_by_default(u32 mwait_hint)
1255 {
1256 	int cstate, limit;
1257 
1258 	/*
1259 	 * If there are no _CST C-states, do not disable any C-states by
1260 	 * default.
1261 	 */
1262 	if (!acpi_state_table.count)
1263 		return false;
1264 
1265 	limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1266 	/*
1267 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1268 	 * the interesting states are ACPI_CSTATE_FFH.
1269 	 */
1270 	for (cstate = 1; cstate < limit; cstate++) {
1271 		if (acpi_state_table.states[cstate].address == mwait_hint)
1272 			return false;
1273 	}
1274 	return true;
1275 }
1276 #else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1277 #define force_use_acpi	(false)
1278 
1279 static inline bool intel_idle_acpi_cst_extract(void) { return false; }
1280 static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
1281 static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
1282 #endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1283 
1284 /**
1285  * ivt_idle_state_table_update - Tune the idle states table for Ivy Town.
1286  *
1287  * Tune IVT multi-socket targets.
1288  * Assumption: num_sockets == (max_package_num + 1).
1289  */
1290 static void __init ivt_idle_state_table_update(void)
1291 {
1292 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1293 	int cpu, package_num, num_sockets = 1;
1294 
1295 	for_each_online_cpu(cpu) {
1296 		package_num = topology_physical_package_id(cpu);
1297 		if (package_num + 1 > num_sockets) {
1298 			num_sockets = package_num + 1;
1299 
1300 			if (num_sockets > 4) {
1301 				cpuidle_state_table = ivt_cstates_8s;
1302 				return;
1303 			}
1304 		}
1305 	}
1306 
1307 	if (num_sockets > 2)
1308 		cpuidle_state_table = ivt_cstates_4s;
1309 
1310 	/* else, 1 and 2 socket systems use default ivt_cstates */
1311 }
1312 
1313 /**
1314  * irtl_2_usec - IRTL to microseconds conversion.
1315  * @irtl: IRTL MSR value.
1316  *
1317  * Translate the IRTL (Interrupt Response Time Limit) MSR value to microseconds.
1318  */
1319 static unsigned long long __init irtl_2_usec(unsigned long long irtl)
1320 {
1321 	static const unsigned int irtl_ns_units[] __initconst = {
1322 		1, 32, 1024, 32768, 1048576, 33554432, 0, 0
1323 	};
1324 	unsigned long long ns;
1325 
1326 	if (!irtl)
1327 		return 0;
1328 
1329 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1330 
1331 	return div_u64((irtl & 0x3FF) * ns, NSEC_PER_USEC);
1332 }
1333 
1334 /**
1335  * bxt_idle_state_table_update - Fix up the Broxton idle states table.
1336  *
1337  * On BXT, trust the IRTL (Interrupt Response Time Limit) MSR to show the
1338  * definitive maximum latency and use the same value for target_residency.
1339  */
1340 static void __init bxt_idle_state_table_update(void)
1341 {
1342 	unsigned long long msr;
1343 	unsigned int usec;
1344 
1345 	rdmsrl(MSR_PKGC6_IRTL, msr);
1346 	usec = irtl_2_usec(msr);
1347 	if (usec) {
1348 		bxt_cstates[2].exit_latency = usec;
1349 		bxt_cstates[2].target_residency = usec;
1350 	}
1351 
1352 	rdmsrl(MSR_PKGC7_IRTL, msr);
1353 	usec = irtl_2_usec(msr);
1354 	if (usec) {
1355 		bxt_cstates[3].exit_latency = usec;
1356 		bxt_cstates[3].target_residency = usec;
1357 	}
1358 
1359 	rdmsrl(MSR_PKGC8_IRTL, msr);
1360 	usec = irtl_2_usec(msr);
1361 	if (usec) {
1362 		bxt_cstates[4].exit_latency = usec;
1363 		bxt_cstates[4].target_residency = usec;
1364 	}
1365 
1366 	rdmsrl(MSR_PKGC9_IRTL, msr);
1367 	usec = irtl_2_usec(msr);
1368 	if (usec) {
1369 		bxt_cstates[5].exit_latency = usec;
1370 		bxt_cstates[5].target_residency = usec;
1371 	}
1372 
1373 	rdmsrl(MSR_PKGC10_IRTL, msr);
1374 	usec = irtl_2_usec(msr);
1375 	if (usec) {
1376 		bxt_cstates[6].exit_latency = usec;
1377 		bxt_cstates[6].target_residency = usec;
1378 	}
1379 
1380 }
1381 
1382 /**
1383  * sklh_idle_state_table_update - Fix up the Sky Lake idle states table.
1384  *
1385  * On SKL-H (model 0x5e) skip C8 and C9 if C10 is enabled and SGX disabled.
1386  */
1387 static void __init sklh_idle_state_table_update(void)
1388 {
1389 	unsigned long long msr;
1390 	unsigned int eax, ebx, ecx, edx;
1391 
1392 
1393 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1394 	if (max_cstate <= 7)
1395 		return;
1396 
1397 	/* if PC10 not present in CPUID.MWAIT.EDX */
1398 	if ((mwait_substates & (0xF << 28)) == 0)
1399 		return;
1400 
1401 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1402 
1403 	/* PC10 is not enabled in PKG C-state limit */
1404 	if ((msr & 0xF) != 8)
1405 		return;
1406 
1407 	ecx = 0;
1408 	cpuid(7, &eax, &ebx, &ecx, &edx);
1409 
1410 	/* if SGX is present */
1411 	if (ebx & (1 << 2)) {
1412 
1413 		rdmsrl(MSR_IA32_FEAT_CTL, msr);
1414 
1415 		/* if SGX is enabled */
1416 		if (msr & (1 << 18))
1417 			return;
1418 	}
1419 
1420 	skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C8-SKL */
1421 	skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C9-SKL */
1422 }
1423 
1424 static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
1425 {
1426 	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
1427 	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
1428 					MWAIT_SUBSTATE_MASK;
1429 
1430 	/* Ignore the C-state if there are NO sub-states in CPUID for it. */
1431 	if (num_substates == 0)
1432 		return false;
1433 
1434 	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1435 		mark_tsc_unstable("TSC halts in idle states deeper than C2");
1436 
1437 	return true;
1438 }
1439 
1440 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
1441 {
1442 	int cstate;
1443 
1444 	switch (boot_cpu_data.x86_model) {
1445 	case INTEL_FAM6_IVYBRIDGE_X:
1446 		ivt_idle_state_table_update();
1447 		break;
1448 	case INTEL_FAM6_ATOM_GOLDMONT:
1449 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1450 		bxt_idle_state_table_update();
1451 		break;
1452 	case INTEL_FAM6_SKYLAKE:
1453 		sklh_idle_state_table_update();
1454 		break;
1455 	}
1456 
1457 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1458 		unsigned int mwait_hint;
1459 
1460 		if (intel_idle_max_cstate_reached(cstate))
1461 			break;
1462 
1463 		if (!cpuidle_state_table[cstate].enter &&
1464 		    !cpuidle_state_table[cstate].enter_s2idle)
1465 			break;
1466 
1467 		/* If marked as unusable, skip this state. */
1468 		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
1469 			pr_debug("state %s is disabled\n",
1470 				 cpuidle_state_table[cstate].name);
1471 			continue;
1472 		}
1473 
1474 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1475 		if (!intel_idle_verify_cstate(mwait_hint))
1476 			continue;
1477 
1478 		/* Structure copy. */
1479 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
1480 
1481 		if ((disabled_states_mask & BIT(drv->state_count)) ||
1482 		    ((icpu->use_acpi || force_use_acpi) &&
1483 		     intel_idle_off_by_default(mwait_hint) &&
1484 		     !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE)))
1485 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF;
1486 
1487 		drv->state_count++;
1488 	}
1489 
1490 	if (icpu->byt_auto_demotion_disable_flag) {
1491 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1492 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1493 	}
1494 }
1495 
1496 /**
1497  * intel_idle_cpuidle_driver_init - Create the list of available idle states.
1498  * @drv: cpuidle driver structure to initialize.
1499  */
1500 static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
1501 {
1502 	cpuidle_poll_state_init(drv);
1503 
1504 	if (disabled_states_mask & BIT(0))
1505 		drv->states[0].flags |= CPUIDLE_FLAG_OFF;
1506 
1507 	drv->state_count = 1;
1508 
1509 	if (icpu)
1510 		intel_idle_init_cstates_icpu(drv);
1511 	else
1512 		intel_idle_init_cstates_acpi(drv);
1513 }
1514 
1515 static void auto_demotion_disable(void)
1516 {
1517 	unsigned long long msr_bits;
1518 
1519 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1520 	msr_bits &= ~auto_demotion_disable_flags;
1521 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1522 }
1523 
1524 static void c1e_promotion_disable(void)
1525 {
1526 	unsigned long long msr_bits;
1527 
1528 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
1529 	msr_bits &= ~0x2;
1530 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
1531 }
1532 
1533 /**
1534  * intel_idle_cpu_init - Register the target CPU with the cpuidle core.
1535  * @cpu: CPU to initialize.
1536  *
1537  * Register a cpuidle device object for @cpu and update its MSRs in accordance
1538  * with the processor model flags.
1539  */
1540 static int intel_idle_cpu_init(unsigned int cpu)
1541 {
1542 	struct cpuidle_device *dev;
1543 
1544 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1545 	dev->cpu = cpu;
1546 
1547 	if (cpuidle_register_device(dev)) {
1548 		pr_debug("cpuidle_register_device %d failed!\n", cpu);
1549 		return -EIO;
1550 	}
1551 
1552 	if (auto_demotion_disable_flags)
1553 		auto_demotion_disable();
1554 
1555 	if (disable_promotion_to_c1e)
1556 		c1e_promotion_disable();
1557 
1558 	return 0;
1559 }
1560 
1561 static int intel_idle_cpu_online(unsigned int cpu)
1562 {
1563 	struct cpuidle_device *dev;
1564 
1565 	if (!lapic_timer_always_reliable)
1566 		tick_broadcast_enable();
1567 
1568 	/*
1569 	 * Some systems can hotplug a cpu at runtime after
1570 	 * the kernel has booted, we have to initialize the
1571 	 * driver in this case
1572 	 */
1573 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1574 	if (!dev->registered)
1575 		return intel_idle_cpu_init(cpu);
1576 
1577 	return 0;
1578 }
1579 
1580 /**
1581  * intel_idle_cpuidle_devices_uninit - Unregister all cpuidle devices.
1582  */
1583 static void __init intel_idle_cpuidle_devices_uninit(void)
1584 {
1585 	int i;
1586 
1587 	for_each_online_cpu(i)
1588 		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
1589 }
1590 
1591 static int __init intel_idle_init(void)
1592 {
1593 	const struct x86_cpu_id *id;
1594 	unsigned int eax, ebx, ecx;
1595 	int retval;
1596 
1597 	/* Do not load intel_idle at all for now if idle= is passed */
1598 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1599 		return -ENODEV;
1600 
1601 	if (max_cstate == 0) {
1602 		pr_debug("disabled\n");
1603 		return -EPERM;
1604 	}
1605 
1606 	id = x86_match_cpu(intel_idle_ids);
1607 	if (id) {
1608 		if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1609 			pr_debug("Please enable MWAIT in BIOS SETUP\n");
1610 			return -ENODEV;
1611 		}
1612 	} else {
1613 		id = x86_match_cpu(intel_mwait_ids);
1614 		if (!id)
1615 			return -ENODEV;
1616 	}
1617 
1618 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1619 		return -ENODEV;
1620 
1621 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1622 
1623 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1624 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1625 	    !mwait_substates)
1626 			return -ENODEV;
1627 
1628 	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1629 
1630 	icpu = (const struct idle_cpu *)id->driver_data;
1631 	if (icpu) {
1632 		cpuidle_state_table = icpu->state_table;
1633 		auto_demotion_disable_flags = icpu->auto_demotion_disable_flags;
1634 		disable_promotion_to_c1e = icpu->disable_promotion_to_c1e;
1635 		if (icpu->use_acpi || force_use_acpi)
1636 			intel_idle_acpi_cst_extract();
1637 	} else if (!intel_idle_acpi_cst_extract()) {
1638 		return -ENODEV;
1639 	}
1640 
1641 	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1642 		 boot_cpu_data.x86_model);
1643 
1644 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1645 	if (!intel_idle_cpuidle_devices)
1646 		return -ENOMEM;
1647 
1648 	intel_idle_cpuidle_driver_init(&intel_idle_driver);
1649 
1650 	retval = cpuidle_register_driver(&intel_idle_driver);
1651 	if (retval) {
1652 		struct cpuidle_driver *drv = cpuidle_get_driver();
1653 		printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1654 		       drv ? drv->name : "none");
1655 		goto init_driver_fail;
1656 	}
1657 
1658 	if (boot_cpu_has(X86_FEATURE_ARAT))	/* Always Reliable APIC Timer */
1659 		lapic_timer_always_reliable = true;
1660 
1661 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1662 				   intel_idle_cpu_online, NULL);
1663 	if (retval < 0)
1664 		goto hp_setup_fail;
1665 
1666 	pr_debug("Local APIC timer is reliable in %s\n",
1667 		 lapic_timer_always_reliable ? "all C-states" : "C1");
1668 
1669 	return 0;
1670 
1671 hp_setup_fail:
1672 	intel_idle_cpuidle_devices_uninit();
1673 	cpuidle_unregister_driver(&intel_idle_driver);
1674 init_driver_fail:
1675 	free_percpu(intel_idle_cpuidle_devices);
1676 	return retval;
1677 
1678 }
1679 device_initcall(intel_idle_init);
1680 
1681 /*
1682  * We are not really modular, but we used to support that.  Meaning we also
1683  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1684  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1685  * is the easiest way (currently) to continue doing that.
1686  */
1687 module_param(max_cstate, int, 0444);
1688 /*
1689  * The positions of the bits that are set in this number are the indices of the
1690  * idle states to be disabled by default (as reflected by the names of the
1691  * corresponding idle state directories in sysfs, "state0", "state1" ...
1692  * "state<i>" ..., where <i> is the index of the given state).
1693  */
1694 module_param_named(states_off, disabled_states_mask, uint, 0444);
1695 MODULE_PARM_DESC(states_off, "Mask of disabled idle states");
1696