xref: /openbmc/linux/drivers/idle/intel_idle.c (revision b2765275)
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, Intel Corporation.
6  * Len Brown <len.brown@intel.com>
7  */
8 
9 /*
10  * intel_idle is a cpuidle driver that loads on specific Intel processors
11  * in lieu of the legacy ACPI processor_idle driver.  The intent is to
12  * make Linux more efficient on these processors, as intel_idle knows
13  * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
14  */
15 
16 /*
17  * Design Assumptions
18  *
19  * All CPUs have same idle states as boot CPU
20  *
21  * Chipset BM_STS (bus master status) bit is a NOP
22  *	for preventing entry into deep C-stats
23  */
24 
25 /*
26  * Known limitations
27  *
28  * The driver currently initializes for_each_online_cpu() upon modprobe.
29  * It it unaware of subsequent processors hot-added to the system.
30  * This means that if you boot with maxcpus=n and later online
31  * processors above n, those processors will use C1 only.
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 "0.4.1"
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 unsigned int mwait_substates;
69 
70 #define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
71 /* Reliable LAPIC Timer States, bit 1 for C1 etc.  */
72 static unsigned int lapic_timer_reliable_states = (1 << 1);	 /* Default to only C1 */
73 
74 struct idle_cpu {
75 	struct cpuidle_state *state_table;
76 
77 	/*
78 	 * Hardware C-state auto-demotion may not always be optimal.
79 	 * Indicate which enable bits to clear here.
80 	 */
81 	unsigned long auto_demotion_disable_flags;
82 	bool byt_auto_demotion_disable_flag;
83 	bool disable_promotion_to_c1e;
84 	bool use_acpi;
85 };
86 
87 static const struct idle_cpu *icpu;
88 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
89 static int intel_idle(struct cpuidle_device *dev,
90 			struct cpuidle_driver *drv, int index);
91 static void intel_idle_s2idle(struct cpuidle_device *dev,
92 			      struct cpuidle_driver *drv, int index);
93 static struct cpuidle_state *cpuidle_state_table;
94 
95 /*
96  * Enable this state by default even if the ACPI _CST does not list it.
97  */
98 #define CPUIDLE_FLAG_ALWAYS_ENABLE	BIT(15)
99 
100 /*
101  * Set this flag for states where the HW flushes the TLB for us
102  * and so we don't need cross-calls to keep it consistent.
103  * If this flag is set, SW flushes the TLB, so even if the
104  * HW doesn't do the flushing, this flag is safe to use.
105  */
106 #define CPUIDLE_FLAG_TLB_FLUSHED	0x10000
107 
108 /*
109  * MWAIT takes an 8-bit "hint" in EAX "suggesting"
110  * the C-state (top nibble) and sub-state (bottom nibble)
111  * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
112  *
113  * We store the hint at the top of our "flags" for each state.
114  */
115 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
116 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
117 
118 /*
119  * States are indexed by the cstate number,
120  * which is also the index into the MWAIT hint array.
121  * Thus C0 is a dummy.
122  */
123 static struct cpuidle_state nehalem_cstates[] = {
124 	{
125 		.name = "C1",
126 		.desc = "MWAIT 0x00",
127 		.flags = MWAIT2flg(0x00),
128 		.exit_latency = 3,
129 		.target_residency = 6,
130 		.enter = &intel_idle,
131 		.enter_s2idle = intel_idle_s2idle, },
132 	{
133 		.name = "C1E",
134 		.desc = "MWAIT 0x01",
135 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
136 		.exit_latency = 10,
137 		.target_residency = 20,
138 		.enter = &intel_idle,
139 		.enter_s2idle = intel_idle_s2idle, },
140 	{
141 		.name = "C3",
142 		.desc = "MWAIT 0x10",
143 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
144 		.exit_latency = 20,
145 		.target_residency = 80,
146 		.enter = &intel_idle,
147 		.enter_s2idle = intel_idle_s2idle, },
148 	{
149 		.name = "C6",
150 		.desc = "MWAIT 0x20",
151 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
152 		.exit_latency = 200,
153 		.target_residency = 800,
154 		.enter = &intel_idle,
155 		.enter_s2idle = intel_idle_s2idle, },
156 	{
157 		.enter = NULL }
158 };
159 
160 static struct cpuidle_state snb_cstates[] = {
161 	{
162 		.name = "C1",
163 		.desc = "MWAIT 0x00",
164 		.flags = MWAIT2flg(0x00),
165 		.exit_latency = 2,
166 		.target_residency = 2,
167 		.enter = &intel_idle,
168 		.enter_s2idle = intel_idle_s2idle, },
169 	{
170 		.name = "C1E",
171 		.desc = "MWAIT 0x01",
172 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
173 		.exit_latency = 10,
174 		.target_residency = 20,
175 		.enter = &intel_idle,
176 		.enter_s2idle = intel_idle_s2idle, },
177 	{
178 		.name = "C3",
179 		.desc = "MWAIT 0x10",
180 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
181 		.exit_latency = 80,
182 		.target_residency = 211,
183 		.enter = &intel_idle,
184 		.enter_s2idle = intel_idle_s2idle, },
185 	{
186 		.name = "C6",
187 		.desc = "MWAIT 0x20",
188 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
189 		.exit_latency = 104,
190 		.target_residency = 345,
191 		.enter = &intel_idle,
192 		.enter_s2idle = intel_idle_s2idle, },
193 	{
194 		.name = "C7",
195 		.desc = "MWAIT 0x30",
196 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
197 		.exit_latency = 109,
198 		.target_residency = 345,
199 		.enter = &intel_idle,
200 		.enter_s2idle = intel_idle_s2idle, },
201 	{
202 		.enter = NULL }
203 };
204 
205 static struct cpuidle_state byt_cstates[] = {
206 	{
207 		.name = "C1",
208 		.desc = "MWAIT 0x00",
209 		.flags = MWAIT2flg(0x00),
210 		.exit_latency = 1,
211 		.target_residency = 1,
212 		.enter = &intel_idle,
213 		.enter_s2idle = intel_idle_s2idle, },
214 	{
215 		.name = "C6N",
216 		.desc = "MWAIT 0x58",
217 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
218 		.exit_latency = 300,
219 		.target_residency = 275,
220 		.enter = &intel_idle,
221 		.enter_s2idle = intel_idle_s2idle, },
222 	{
223 		.name = "C6S",
224 		.desc = "MWAIT 0x52",
225 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
226 		.exit_latency = 500,
227 		.target_residency = 560,
228 		.enter = &intel_idle,
229 		.enter_s2idle = intel_idle_s2idle, },
230 	{
231 		.name = "C7",
232 		.desc = "MWAIT 0x60",
233 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
234 		.exit_latency = 1200,
235 		.target_residency = 4000,
236 		.enter = &intel_idle,
237 		.enter_s2idle = intel_idle_s2idle, },
238 	{
239 		.name = "C7S",
240 		.desc = "MWAIT 0x64",
241 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
242 		.exit_latency = 10000,
243 		.target_residency = 20000,
244 		.enter = &intel_idle,
245 		.enter_s2idle = intel_idle_s2idle, },
246 	{
247 		.enter = NULL }
248 };
249 
250 static struct cpuidle_state cht_cstates[] = {
251 	{
252 		.name = "C1",
253 		.desc = "MWAIT 0x00",
254 		.flags = MWAIT2flg(0x00),
255 		.exit_latency = 1,
256 		.target_residency = 1,
257 		.enter = &intel_idle,
258 		.enter_s2idle = intel_idle_s2idle, },
259 	{
260 		.name = "C6N",
261 		.desc = "MWAIT 0x58",
262 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
263 		.exit_latency = 80,
264 		.target_residency = 275,
265 		.enter = &intel_idle,
266 		.enter_s2idle = intel_idle_s2idle, },
267 	{
268 		.name = "C6S",
269 		.desc = "MWAIT 0x52",
270 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
271 		.exit_latency = 200,
272 		.target_residency = 560,
273 		.enter = &intel_idle,
274 		.enter_s2idle = intel_idle_s2idle, },
275 	{
276 		.name = "C7",
277 		.desc = "MWAIT 0x60",
278 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
279 		.exit_latency = 1200,
280 		.target_residency = 4000,
281 		.enter = &intel_idle,
282 		.enter_s2idle = intel_idle_s2idle, },
283 	{
284 		.name = "C7S",
285 		.desc = "MWAIT 0x64",
286 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
287 		.exit_latency = 10000,
288 		.target_residency = 20000,
289 		.enter = &intel_idle,
290 		.enter_s2idle = intel_idle_s2idle, },
291 	{
292 		.enter = NULL }
293 };
294 
295 static struct cpuidle_state ivb_cstates[] = {
296 	{
297 		.name = "C1",
298 		.desc = "MWAIT 0x00",
299 		.flags = MWAIT2flg(0x00),
300 		.exit_latency = 1,
301 		.target_residency = 1,
302 		.enter = &intel_idle,
303 		.enter_s2idle = intel_idle_s2idle, },
304 	{
305 		.name = "C1E",
306 		.desc = "MWAIT 0x01",
307 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
308 		.exit_latency = 10,
309 		.target_residency = 20,
310 		.enter = &intel_idle,
311 		.enter_s2idle = intel_idle_s2idle, },
312 	{
313 		.name = "C3",
314 		.desc = "MWAIT 0x10",
315 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
316 		.exit_latency = 59,
317 		.target_residency = 156,
318 		.enter = &intel_idle,
319 		.enter_s2idle = intel_idle_s2idle, },
320 	{
321 		.name = "C6",
322 		.desc = "MWAIT 0x20",
323 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
324 		.exit_latency = 80,
325 		.target_residency = 300,
326 		.enter = &intel_idle,
327 		.enter_s2idle = intel_idle_s2idle, },
328 	{
329 		.name = "C7",
330 		.desc = "MWAIT 0x30",
331 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
332 		.exit_latency = 87,
333 		.target_residency = 300,
334 		.enter = &intel_idle,
335 		.enter_s2idle = intel_idle_s2idle, },
336 	{
337 		.enter = NULL }
338 };
339 
340 static struct cpuidle_state ivt_cstates[] = {
341 	{
342 		.name = "C1",
343 		.desc = "MWAIT 0x00",
344 		.flags = MWAIT2flg(0x00),
345 		.exit_latency = 1,
346 		.target_residency = 1,
347 		.enter = &intel_idle,
348 		.enter_s2idle = intel_idle_s2idle, },
349 	{
350 		.name = "C1E",
351 		.desc = "MWAIT 0x01",
352 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
353 		.exit_latency = 10,
354 		.target_residency = 80,
355 		.enter = &intel_idle,
356 		.enter_s2idle = intel_idle_s2idle, },
357 	{
358 		.name = "C3",
359 		.desc = "MWAIT 0x10",
360 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
361 		.exit_latency = 59,
362 		.target_residency = 156,
363 		.enter = &intel_idle,
364 		.enter_s2idle = intel_idle_s2idle, },
365 	{
366 		.name = "C6",
367 		.desc = "MWAIT 0x20",
368 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
369 		.exit_latency = 82,
370 		.target_residency = 300,
371 		.enter = &intel_idle,
372 		.enter_s2idle = intel_idle_s2idle, },
373 	{
374 		.enter = NULL }
375 };
376 
377 static struct cpuidle_state ivt_cstates_4s[] = {
378 	{
379 		.name = "C1",
380 		.desc = "MWAIT 0x00",
381 		.flags = MWAIT2flg(0x00),
382 		.exit_latency = 1,
383 		.target_residency = 1,
384 		.enter = &intel_idle,
385 		.enter_s2idle = intel_idle_s2idle, },
386 	{
387 		.name = "C1E",
388 		.desc = "MWAIT 0x01",
389 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
390 		.exit_latency = 10,
391 		.target_residency = 250,
392 		.enter = &intel_idle,
393 		.enter_s2idle = intel_idle_s2idle, },
394 	{
395 		.name = "C3",
396 		.desc = "MWAIT 0x10",
397 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
398 		.exit_latency = 59,
399 		.target_residency = 300,
400 		.enter = &intel_idle,
401 		.enter_s2idle = intel_idle_s2idle, },
402 	{
403 		.name = "C6",
404 		.desc = "MWAIT 0x20",
405 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
406 		.exit_latency = 84,
407 		.target_residency = 400,
408 		.enter = &intel_idle,
409 		.enter_s2idle = intel_idle_s2idle, },
410 	{
411 		.enter = NULL }
412 };
413 
414 static struct cpuidle_state ivt_cstates_8s[] = {
415 	{
416 		.name = "C1",
417 		.desc = "MWAIT 0x00",
418 		.flags = MWAIT2flg(0x00),
419 		.exit_latency = 1,
420 		.target_residency = 1,
421 		.enter = &intel_idle,
422 		.enter_s2idle = intel_idle_s2idle, },
423 	{
424 		.name = "C1E",
425 		.desc = "MWAIT 0x01",
426 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
427 		.exit_latency = 10,
428 		.target_residency = 500,
429 		.enter = &intel_idle,
430 		.enter_s2idle = intel_idle_s2idle, },
431 	{
432 		.name = "C3",
433 		.desc = "MWAIT 0x10",
434 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
435 		.exit_latency = 59,
436 		.target_residency = 600,
437 		.enter = &intel_idle,
438 		.enter_s2idle = intel_idle_s2idle, },
439 	{
440 		.name = "C6",
441 		.desc = "MWAIT 0x20",
442 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
443 		.exit_latency = 88,
444 		.target_residency = 700,
445 		.enter = &intel_idle,
446 		.enter_s2idle = intel_idle_s2idle, },
447 	{
448 		.enter = NULL }
449 };
450 
451 static struct cpuidle_state hsw_cstates[] = {
452 	{
453 		.name = "C1",
454 		.desc = "MWAIT 0x00",
455 		.flags = MWAIT2flg(0x00),
456 		.exit_latency = 2,
457 		.target_residency = 2,
458 		.enter = &intel_idle,
459 		.enter_s2idle = intel_idle_s2idle, },
460 	{
461 		.name = "C1E",
462 		.desc = "MWAIT 0x01",
463 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
464 		.exit_latency = 10,
465 		.target_residency = 20,
466 		.enter = &intel_idle,
467 		.enter_s2idle = intel_idle_s2idle, },
468 	{
469 		.name = "C3",
470 		.desc = "MWAIT 0x10",
471 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
472 		.exit_latency = 33,
473 		.target_residency = 100,
474 		.enter = &intel_idle,
475 		.enter_s2idle = intel_idle_s2idle, },
476 	{
477 		.name = "C6",
478 		.desc = "MWAIT 0x20",
479 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
480 		.exit_latency = 133,
481 		.target_residency = 400,
482 		.enter = &intel_idle,
483 		.enter_s2idle = intel_idle_s2idle, },
484 	{
485 		.name = "C7s",
486 		.desc = "MWAIT 0x32",
487 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
488 		.exit_latency = 166,
489 		.target_residency = 500,
490 		.enter = &intel_idle,
491 		.enter_s2idle = intel_idle_s2idle, },
492 	{
493 		.name = "C8",
494 		.desc = "MWAIT 0x40",
495 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
496 		.exit_latency = 300,
497 		.target_residency = 900,
498 		.enter = &intel_idle,
499 		.enter_s2idle = intel_idle_s2idle, },
500 	{
501 		.name = "C9",
502 		.desc = "MWAIT 0x50",
503 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
504 		.exit_latency = 600,
505 		.target_residency = 1800,
506 		.enter = &intel_idle,
507 		.enter_s2idle = intel_idle_s2idle, },
508 	{
509 		.name = "C10",
510 		.desc = "MWAIT 0x60",
511 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
512 		.exit_latency = 2600,
513 		.target_residency = 7700,
514 		.enter = &intel_idle,
515 		.enter_s2idle = intel_idle_s2idle, },
516 	{
517 		.enter = NULL }
518 };
519 static struct cpuidle_state bdw_cstates[] = {
520 	{
521 		.name = "C1",
522 		.desc = "MWAIT 0x00",
523 		.flags = MWAIT2flg(0x00),
524 		.exit_latency = 2,
525 		.target_residency = 2,
526 		.enter = &intel_idle,
527 		.enter_s2idle = intel_idle_s2idle, },
528 	{
529 		.name = "C1E",
530 		.desc = "MWAIT 0x01",
531 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
532 		.exit_latency = 10,
533 		.target_residency = 20,
534 		.enter = &intel_idle,
535 		.enter_s2idle = intel_idle_s2idle, },
536 	{
537 		.name = "C3",
538 		.desc = "MWAIT 0x10",
539 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
540 		.exit_latency = 40,
541 		.target_residency = 100,
542 		.enter = &intel_idle,
543 		.enter_s2idle = intel_idle_s2idle, },
544 	{
545 		.name = "C6",
546 		.desc = "MWAIT 0x20",
547 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
548 		.exit_latency = 133,
549 		.target_residency = 400,
550 		.enter = &intel_idle,
551 		.enter_s2idle = intel_idle_s2idle, },
552 	{
553 		.name = "C7s",
554 		.desc = "MWAIT 0x32",
555 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
556 		.exit_latency = 166,
557 		.target_residency = 500,
558 		.enter = &intel_idle,
559 		.enter_s2idle = intel_idle_s2idle, },
560 	{
561 		.name = "C8",
562 		.desc = "MWAIT 0x40",
563 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
564 		.exit_latency = 300,
565 		.target_residency = 900,
566 		.enter = &intel_idle,
567 		.enter_s2idle = intel_idle_s2idle, },
568 	{
569 		.name = "C9",
570 		.desc = "MWAIT 0x50",
571 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
572 		.exit_latency = 600,
573 		.target_residency = 1800,
574 		.enter = &intel_idle,
575 		.enter_s2idle = intel_idle_s2idle, },
576 	{
577 		.name = "C10",
578 		.desc = "MWAIT 0x60",
579 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
580 		.exit_latency = 2600,
581 		.target_residency = 7700,
582 		.enter = &intel_idle,
583 		.enter_s2idle = intel_idle_s2idle, },
584 	{
585 		.enter = NULL }
586 };
587 
588 static struct cpuidle_state skl_cstates[] = {
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 = 70,
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 = 85,
618 		.target_residency = 200,
619 		.enter = &intel_idle,
620 		.enter_s2idle = intel_idle_s2idle, },
621 	{
622 		.name = "C7s",
623 		.desc = "MWAIT 0x33",
624 		.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
625 		.exit_latency = 124,
626 		.target_residency = 800,
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 = 200,
634 		.target_residency = 800,
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 = 480,
642 		.target_residency = 5000,
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 = 890,
650 		.target_residency = 5000,
651 		.enter = &intel_idle,
652 		.enter_s2idle = intel_idle_s2idle, },
653 	{
654 		.enter = NULL }
655 };
656 
657 static struct cpuidle_state skx_cstates[] = {
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 = "C6",
676 		.desc = "MWAIT 0x20",
677 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
678 		.exit_latency = 133,
679 		.target_residency = 600,
680 		.enter = &intel_idle,
681 		.enter_s2idle = intel_idle_s2idle, },
682 	{
683 		.enter = NULL }
684 };
685 
686 static struct cpuidle_state atom_cstates[] = {
687 	{
688 		.name = "C1E",
689 		.desc = "MWAIT 0x00",
690 		.flags = MWAIT2flg(0x00),
691 		.exit_latency = 10,
692 		.target_residency = 20,
693 		.enter = &intel_idle,
694 		.enter_s2idle = intel_idle_s2idle, },
695 	{
696 		.name = "C2",
697 		.desc = "MWAIT 0x10",
698 		.flags = MWAIT2flg(0x10),
699 		.exit_latency = 20,
700 		.target_residency = 80,
701 		.enter = &intel_idle,
702 		.enter_s2idle = intel_idle_s2idle, },
703 	{
704 		.name = "C4",
705 		.desc = "MWAIT 0x30",
706 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
707 		.exit_latency = 100,
708 		.target_residency = 400,
709 		.enter = &intel_idle,
710 		.enter_s2idle = intel_idle_s2idle, },
711 	{
712 		.name = "C6",
713 		.desc = "MWAIT 0x52",
714 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
715 		.exit_latency = 140,
716 		.target_residency = 560,
717 		.enter = &intel_idle,
718 		.enter_s2idle = intel_idle_s2idle, },
719 	{
720 		.enter = NULL }
721 };
722 static struct cpuidle_state tangier_cstates[] = {
723 	{
724 		.name = "C1",
725 		.desc = "MWAIT 0x00",
726 		.flags = MWAIT2flg(0x00),
727 		.exit_latency = 1,
728 		.target_residency = 4,
729 		.enter = &intel_idle,
730 		.enter_s2idle = intel_idle_s2idle, },
731 	{
732 		.name = "C4",
733 		.desc = "MWAIT 0x30",
734 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
735 		.exit_latency = 100,
736 		.target_residency = 400,
737 		.enter = &intel_idle,
738 		.enter_s2idle = intel_idle_s2idle, },
739 	{
740 		.name = "C6",
741 		.desc = "MWAIT 0x52",
742 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
743 		.exit_latency = 140,
744 		.target_residency = 560,
745 		.enter = &intel_idle,
746 		.enter_s2idle = intel_idle_s2idle, },
747 	{
748 		.name = "C7",
749 		.desc = "MWAIT 0x60",
750 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
751 		.exit_latency = 1200,
752 		.target_residency = 4000,
753 		.enter = &intel_idle,
754 		.enter_s2idle = intel_idle_s2idle, },
755 	{
756 		.name = "C9",
757 		.desc = "MWAIT 0x64",
758 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
759 		.exit_latency = 10000,
760 		.target_residency = 20000,
761 		.enter = &intel_idle,
762 		.enter_s2idle = intel_idle_s2idle, },
763 	{
764 		.enter = NULL }
765 };
766 static struct cpuidle_state avn_cstates[] = {
767 	{
768 		.name = "C1",
769 		.desc = "MWAIT 0x00",
770 		.flags = MWAIT2flg(0x00),
771 		.exit_latency = 2,
772 		.target_residency = 2,
773 		.enter = &intel_idle,
774 		.enter_s2idle = intel_idle_s2idle, },
775 	{
776 		.name = "C6",
777 		.desc = "MWAIT 0x51",
778 		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
779 		.exit_latency = 15,
780 		.target_residency = 45,
781 		.enter = &intel_idle,
782 		.enter_s2idle = intel_idle_s2idle, },
783 	{
784 		.enter = NULL }
785 };
786 static struct cpuidle_state knl_cstates[] = {
787 	{
788 		.name = "C1",
789 		.desc = "MWAIT 0x00",
790 		.flags = MWAIT2flg(0x00),
791 		.exit_latency = 1,
792 		.target_residency = 2,
793 		.enter = &intel_idle,
794 		.enter_s2idle = intel_idle_s2idle },
795 	{
796 		.name = "C6",
797 		.desc = "MWAIT 0x10",
798 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
799 		.exit_latency = 120,
800 		.target_residency = 500,
801 		.enter = &intel_idle,
802 		.enter_s2idle = intel_idle_s2idle },
803 	{
804 		.enter = NULL }
805 };
806 
807 static struct cpuidle_state bxt_cstates[] = {
808 	{
809 		.name = "C1",
810 		.desc = "MWAIT 0x00",
811 		.flags = MWAIT2flg(0x00),
812 		.exit_latency = 2,
813 		.target_residency = 2,
814 		.enter = &intel_idle,
815 		.enter_s2idle = intel_idle_s2idle, },
816 	{
817 		.name = "C1E",
818 		.desc = "MWAIT 0x01",
819 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
820 		.exit_latency = 10,
821 		.target_residency = 20,
822 		.enter = &intel_idle,
823 		.enter_s2idle = intel_idle_s2idle, },
824 	{
825 		.name = "C6",
826 		.desc = "MWAIT 0x20",
827 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
828 		.exit_latency = 133,
829 		.target_residency = 133,
830 		.enter = &intel_idle,
831 		.enter_s2idle = intel_idle_s2idle, },
832 	{
833 		.name = "C7s",
834 		.desc = "MWAIT 0x31",
835 		.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
836 		.exit_latency = 155,
837 		.target_residency = 155,
838 		.enter = &intel_idle,
839 		.enter_s2idle = intel_idle_s2idle, },
840 	{
841 		.name = "C8",
842 		.desc = "MWAIT 0x40",
843 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
844 		.exit_latency = 1000,
845 		.target_residency = 1000,
846 		.enter = &intel_idle,
847 		.enter_s2idle = intel_idle_s2idle, },
848 	{
849 		.name = "C9",
850 		.desc = "MWAIT 0x50",
851 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
852 		.exit_latency = 2000,
853 		.target_residency = 2000,
854 		.enter = &intel_idle,
855 		.enter_s2idle = intel_idle_s2idle, },
856 	{
857 		.name = "C10",
858 		.desc = "MWAIT 0x60",
859 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
860 		.exit_latency = 10000,
861 		.target_residency = 10000,
862 		.enter = &intel_idle,
863 		.enter_s2idle = intel_idle_s2idle, },
864 	{
865 		.enter = NULL }
866 };
867 
868 static struct cpuidle_state dnv_cstates[] = {
869 	{
870 		.name = "C1",
871 		.desc = "MWAIT 0x00",
872 		.flags = MWAIT2flg(0x00),
873 		.exit_latency = 2,
874 		.target_residency = 2,
875 		.enter = &intel_idle,
876 		.enter_s2idle = intel_idle_s2idle, },
877 	{
878 		.name = "C1E",
879 		.desc = "MWAIT 0x01",
880 		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
881 		.exit_latency = 10,
882 		.target_residency = 20,
883 		.enter = &intel_idle,
884 		.enter_s2idle = intel_idle_s2idle, },
885 	{
886 		.name = "C6",
887 		.desc = "MWAIT 0x20",
888 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
889 		.exit_latency = 50,
890 		.target_residency = 500,
891 		.enter = &intel_idle,
892 		.enter_s2idle = intel_idle_s2idle, },
893 	{
894 		.enter = NULL }
895 };
896 
897 /**
898  * intel_idle
899  * @dev: cpuidle_device
900  * @drv: cpuidle driver
901  * @index: index of cpuidle state
902  *
903  * Must be called under local_irq_disable().
904  */
905 static __cpuidle int intel_idle(struct cpuidle_device *dev,
906 				struct cpuidle_driver *drv, int index)
907 {
908 	unsigned long ecx = 1; /* break on interrupt flag */
909 	struct cpuidle_state *state = &drv->states[index];
910 	unsigned long eax = flg2MWAIT(state->flags);
911 	unsigned int cstate;
912 	bool uninitialized_var(tick);
913 	int cpu = smp_processor_id();
914 
915 	/*
916 	 * leave_mm() to avoid costly and often unnecessary wakeups
917 	 * for flushing the user TLB's associated with the active mm.
918 	 */
919 	if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
920 		leave_mm(cpu);
921 
922 	if (!static_cpu_has(X86_FEATURE_ARAT)) {
923 		cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) &
924 				MWAIT_CSTATE_MASK) + 1;
925 		tick = false;
926 		if (!(lapic_timer_reliable_states & (1 << (cstate)))) {
927 			tick = true;
928 			tick_broadcast_enter();
929 		}
930 	}
931 
932 	mwait_idle_with_hints(eax, ecx);
933 
934 	if (!static_cpu_has(X86_FEATURE_ARAT) && tick)
935 		tick_broadcast_exit();
936 
937 	return index;
938 }
939 
940 /**
941  * intel_idle_s2idle - simplified "enter" callback routine for suspend-to-idle
942  * @dev: cpuidle_device
943  * @drv: cpuidle driver
944  * @index: state index
945  */
946 static void intel_idle_s2idle(struct cpuidle_device *dev,
947 			     struct cpuidle_driver *drv, int index)
948 {
949 	unsigned long ecx = 1; /* break on interrupt flag */
950 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
951 
952 	mwait_idle_with_hints(eax, ecx);
953 }
954 
955 static const struct idle_cpu idle_cpu_nehalem = {
956 	.state_table = nehalem_cstates,
957 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
958 	.disable_promotion_to_c1e = true,
959 };
960 
961 static const struct idle_cpu idle_cpu_nhx = {
962 	.state_table = nehalem_cstates,
963 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
964 	.disable_promotion_to_c1e = true,
965 	.use_acpi = true,
966 };
967 
968 static const struct idle_cpu idle_cpu_atom = {
969 	.state_table = atom_cstates,
970 };
971 
972 static const struct idle_cpu idle_cpu_tangier = {
973 	.state_table = tangier_cstates,
974 };
975 
976 static const struct idle_cpu idle_cpu_lincroft = {
977 	.state_table = atom_cstates,
978 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
979 };
980 
981 static const struct idle_cpu idle_cpu_snb = {
982 	.state_table = snb_cstates,
983 	.disable_promotion_to_c1e = true,
984 };
985 
986 static const struct idle_cpu idle_cpu_snx = {
987 	.state_table = snb_cstates,
988 	.disable_promotion_to_c1e = true,
989 	.use_acpi = true,
990 };
991 
992 static const struct idle_cpu idle_cpu_byt = {
993 	.state_table = byt_cstates,
994 	.disable_promotion_to_c1e = true,
995 	.byt_auto_demotion_disable_flag = true,
996 };
997 
998 static const struct idle_cpu idle_cpu_cht = {
999 	.state_table = cht_cstates,
1000 	.disable_promotion_to_c1e = true,
1001 	.byt_auto_demotion_disable_flag = true,
1002 };
1003 
1004 static const struct idle_cpu idle_cpu_ivb = {
1005 	.state_table = ivb_cstates,
1006 	.disable_promotion_to_c1e = true,
1007 };
1008 
1009 static const struct idle_cpu idle_cpu_ivt = {
1010 	.state_table = ivt_cstates,
1011 	.disable_promotion_to_c1e = true,
1012 	.use_acpi = true,
1013 };
1014 
1015 static const struct idle_cpu idle_cpu_hsw = {
1016 	.state_table = hsw_cstates,
1017 	.disable_promotion_to_c1e = true,
1018 };
1019 
1020 static const struct idle_cpu idle_cpu_hsx = {
1021 	.state_table = hsw_cstates,
1022 	.disable_promotion_to_c1e = true,
1023 	.use_acpi = true,
1024 };
1025 
1026 static const struct idle_cpu idle_cpu_bdw = {
1027 	.state_table = bdw_cstates,
1028 	.disable_promotion_to_c1e = true,
1029 };
1030 
1031 static const struct idle_cpu idle_cpu_bdx = {
1032 	.state_table = bdw_cstates,
1033 	.disable_promotion_to_c1e = true,
1034 	.use_acpi = true,
1035 };
1036 
1037 static const struct idle_cpu idle_cpu_skl = {
1038 	.state_table = skl_cstates,
1039 	.disable_promotion_to_c1e = true,
1040 };
1041 
1042 static const struct idle_cpu idle_cpu_skx = {
1043 	.state_table = skx_cstates,
1044 	.disable_promotion_to_c1e = true,
1045 	.use_acpi = true,
1046 };
1047 
1048 static const struct idle_cpu idle_cpu_avn = {
1049 	.state_table = avn_cstates,
1050 	.disable_promotion_to_c1e = true,
1051 	.use_acpi = true,
1052 };
1053 
1054 static const struct idle_cpu idle_cpu_knl = {
1055 	.state_table = knl_cstates,
1056 	.use_acpi = true,
1057 };
1058 
1059 static const struct idle_cpu idle_cpu_bxt = {
1060 	.state_table = bxt_cstates,
1061 	.disable_promotion_to_c1e = true,
1062 };
1063 
1064 static const struct idle_cpu idle_cpu_dnv = {
1065 	.state_table = dnv_cstates,
1066 	.disable_promotion_to_c1e = true,
1067 	.use_acpi = true,
1068 };
1069 
1070 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1071 	INTEL_CPU_FAM6(NEHALEM_EP,		idle_cpu_nhx),
1072 	INTEL_CPU_FAM6(NEHALEM,			idle_cpu_nehalem),
1073 	INTEL_CPU_FAM6(NEHALEM_G,		idle_cpu_nehalem),
1074 	INTEL_CPU_FAM6(WESTMERE,		idle_cpu_nehalem),
1075 	INTEL_CPU_FAM6(WESTMERE_EP,		idle_cpu_nhx),
1076 	INTEL_CPU_FAM6(NEHALEM_EX,		idle_cpu_nhx),
1077 	INTEL_CPU_FAM6(ATOM_BONNELL,		idle_cpu_atom),
1078 	INTEL_CPU_FAM6(ATOM_BONNELL_MID,	idle_cpu_lincroft),
1079 	INTEL_CPU_FAM6(WESTMERE_EX,		idle_cpu_nhx),
1080 	INTEL_CPU_FAM6(SANDYBRIDGE,		idle_cpu_snb),
1081 	INTEL_CPU_FAM6(SANDYBRIDGE_X,		idle_cpu_snx),
1082 	INTEL_CPU_FAM6(ATOM_SALTWELL,		idle_cpu_atom),
1083 	INTEL_CPU_FAM6(ATOM_SILVERMONT,		idle_cpu_byt),
1084 	INTEL_CPU_FAM6(ATOM_SILVERMONT_MID,	idle_cpu_tangier),
1085 	INTEL_CPU_FAM6(ATOM_AIRMONT,		idle_cpu_cht),
1086 	INTEL_CPU_FAM6(IVYBRIDGE,		idle_cpu_ivb),
1087 	INTEL_CPU_FAM6(IVYBRIDGE_X,		idle_cpu_ivt),
1088 	INTEL_CPU_FAM6(HASWELL,			idle_cpu_hsw),
1089 	INTEL_CPU_FAM6(HASWELL_X,		idle_cpu_hsx),
1090 	INTEL_CPU_FAM6(HASWELL_L,		idle_cpu_hsw),
1091 	INTEL_CPU_FAM6(HASWELL_G,		idle_cpu_hsw),
1092 	INTEL_CPU_FAM6(ATOM_SILVERMONT_D,	idle_cpu_avn),
1093 	INTEL_CPU_FAM6(BROADWELL,		idle_cpu_bdw),
1094 	INTEL_CPU_FAM6(BROADWELL_G,		idle_cpu_bdw),
1095 	INTEL_CPU_FAM6(BROADWELL_X,		idle_cpu_bdx),
1096 	INTEL_CPU_FAM6(BROADWELL_D,		idle_cpu_bdx),
1097 	INTEL_CPU_FAM6(SKYLAKE_L,		idle_cpu_skl),
1098 	INTEL_CPU_FAM6(SKYLAKE,			idle_cpu_skl),
1099 	INTEL_CPU_FAM6(KABYLAKE_L,		idle_cpu_skl),
1100 	INTEL_CPU_FAM6(KABYLAKE,		idle_cpu_skl),
1101 	INTEL_CPU_FAM6(SKYLAKE_X,		idle_cpu_skx),
1102 	INTEL_CPU_FAM6(XEON_PHI_KNL,		idle_cpu_knl),
1103 	INTEL_CPU_FAM6(XEON_PHI_KNM,		idle_cpu_knl),
1104 	INTEL_CPU_FAM6(ATOM_GOLDMONT,		idle_cpu_bxt),
1105 	INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS,	idle_cpu_bxt),
1106 	INTEL_CPU_FAM6(ATOM_GOLDMONT_D,		idle_cpu_dnv),
1107 	INTEL_CPU_FAM6(ATOM_TREMONT_D,		idle_cpu_dnv),
1108 	{}
1109 };
1110 
1111 #define INTEL_CPU_FAM6_MWAIT \
1112 	{ X86_VENDOR_INTEL, 6, X86_MODEL_ANY, X86_FEATURE_MWAIT, 0 }
1113 
1114 static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
1115 	INTEL_CPU_FAM6_MWAIT,
1116 	{}
1117 };
1118 
1119 static bool __init intel_idle_max_cstate_reached(int cstate)
1120 {
1121 	if (cstate + 1 > max_cstate) {
1122 		pr_info("max_cstate %d reached\n", max_cstate);
1123 		return true;
1124 	}
1125 	return false;
1126 }
1127 
1128 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
1129 #include <acpi/processor.h>
1130 
1131 static bool no_acpi __read_mostly;
1132 module_param(no_acpi, bool, 0444);
1133 MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list");
1134 
1135 static bool force_use_acpi __read_mostly; /* No effect if no_acpi is set. */
1136 module_param_named(use_acpi, force_use_acpi, bool, 0444);
1137 MODULE_PARM_DESC(use_acpi, "Use ACPI _CST for building the idle states list");
1138 
1139 static struct acpi_processor_power acpi_state_table __initdata;
1140 
1141 /**
1142  * intel_idle_cst_usable - Check if the _CST information can be used.
1143  *
1144  * Check if all of the C-states listed by _CST in the max_cstate range are
1145  * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
1146  */
1147 static bool __init intel_idle_cst_usable(void)
1148 {
1149 	int cstate, limit;
1150 
1151 	limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
1152 		      acpi_state_table.count);
1153 
1154 	for (cstate = 1; cstate < limit; cstate++) {
1155 		struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
1156 
1157 		if (cx->entry_method != ACPI_CSTATE_FFH)
1158 			return false;
1159 	}
1160 
1161 	return true;
1162 }
1163 
1164 static bool __init intel_idle_acpi_cst_extract(void)
1165 {
1166 	unsigned int cpu;
1167 
1168 	if (no_acpi) {
1169 		pr_debug("Not allowed to use ACPI _CST\n");
1170 		return false;
1171 	}
1172 
1173 	for_each_possible_cpu(cpu) {
1174 		struct acpi_processor *pr = per_cpu(processors, cpu);
1175 
1176 		if (!pr)
1177 			continue;
1178 
1179 		if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
1180 			continue;
1181 
1182 		acpi_state_table.count++;
1183 
1184 		if (!intel_idle_cst_usable())
1185 			continue;
1186 
1187 		if (!acpi_processor_claim_cst_control()) {
1188 			acpi_state_table.count = 0;
1189 			return false;
1190 		}
1191 
1192 		return true;
1193 	}
1194 
1195 	pr_debug("ACPI _CST not found or not usable\n");
1196 	return false;
1197 }
1198 
1199 static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
1200 {
1201 	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1202 
1203 	/*
1204 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1205 	 * the interesting states are ACPI_CSTATE_FFH.
1206 	 */
1207 	for (cstate = 1; cstate < limit; cstate++) {
1208 		struct acpi_processor_cx *cx;
1209 		struct cpuidle_state *state;
1210 
1211 		if (intel_idle_max_cstate_reached(cstate))
1212 			break;
1213 
1214 		cx = &acpi_state_table.states[cstate];
1215 
1216 		state = &drv->states[drv->state_count++];
1217 
1218 		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
1219 		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1220 		state->exit_latency = cx->latency;
1221 		/*
1222 		 * For C1-type C-states use the same number for both the exit
1223 		 * latency and target residency, because that is the case for
1224 		 * C1 in the majority of the static C-states tables above.
1225 		 * For the other types of C-states, however, set the target
1226 		 * residency to 3 times the exit latency which should lead to
1227 		 * a reasonable balance between energy-efficiency and
1228 		 * performance in the majority of interesting cases.
1229 		 */
1230 		state->target_residency = cx->latency;
1231 		if (cx->type > ACPI_STATE_C1)
1232 			state->target_residency *= 3;
1233 
1234 		state->flags = MWAIT2flg(cx->address);
1235 		if (cx->type > ACPI_STATE_C2)
1236 			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
1237 
1238 		if (disabled_states_mask & BIT(cstate))
1239 			state->flags |= CPUIDLE_FLAG_OFF;
1240 
1241 		state->enter = intel_idle;
1242 		state->enter_s2idle = intel_idle_s2idle;
1243 	}
1244 }
1245 
1246 static bool __init intel_idle_off_by_default(u32 mwait_hint)
1247 {
1248 	int cstate, limit;
1249 
1250 	/*
1251 	 * If there are no _CST C-states, do not disable any C-states by
1252 	 * default.
1253 	 */
1254 	if (!acpi_state_table.count)
1255 		return false;
1256 
1257 	limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
1258 	/*
1259 	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
1260 	 * the interesting states are ACPI_CSTATE_FFH.
1261 	 */
1262 	for (cstate = 1; cstate < limit; cstate++) {
1263 		if (acpi_state_table.states[cstate].address == mwait_hint)
1264 			return false;
1265 	}
1266 	return true;
1267 }
1268 #else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1269 #define force_use_acpi	(false)
1270 
1271 static inline bool intel_idle_acpi_cst_extract(void) { return false; }
1272 static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
1273 static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
1274 #endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
1275 
1276 /*
1277  * ivt_idle_state_table_update(void)
1278  *
1279  * Tune IVT multi-socket targets
1280  * Assumption: num_sockets == (max_package_num + 1)
1281  */
1282 static void __init ivt_idle_state_table_update(void)
1283 {
1284 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1285 	int cpu, package_num, num_sockets = 1;
1286 
1287 	for_each_online_cpu(cpu) {
1288 		package_num = topology_physical_package_id(cpu);
1289 		if (package_num + 1 > num_sockets) {
1290 			num_sockets = package_num + 1;
1291 
1292 			if (num_sockets > 4) {
1293 				cpuidle_state_table = ivt_cstates_8s;
1294 				return;
1295 			}
1296 		}
1297 	}
1298 
1299 	if (num_sockets > 2)
1300 		cpuidle_state_table = ivt_cstates_4s;
1301 
1302 	/* else, 1 and 2 socket systems use default ivt_cstates */
1303 }
1304 
1305 /**
1306  * irtl_2_usec - IRTL to microseconds conversion.
1307  * @irtl: IRTL MSR value.
1308  *
1309  * Translate the IRTL (Interrupt Response Time Limit) MSR value to microseconds.
1310  */
1311 static unsigned long long __init irtl_2_usec(unsigned long long irtl)
1312 {
1313 	static const unsigned int irtl_ns_units[] __initconst = {
1314 		1, 32, 1024, 32768, 1048576, 33554432, 0, 0
1315 	};
1316 	unsigned long long ns;
1317 
1318 	if (!irtl)
1319 		return 0;
1320 
1321 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1322 
1323 	return div_u64((irtl & 0x3FF) * ns, NSEC_PER_USEC);
1324 }
1325 
1326 /*
1327  * bxt_idle_state_table_update(void)
1328  *
1329  * On BXT, we trust the IRTL to show the definitive maximum latency
1330  * We use the same value for target_residency.
1331  */
1332 static void __init bxt_idle_state_table_update(void)
1333 {
1334 	unsigned long long msr;
1335 	unsigned int usec;
1336 
1337 	rdmsrl(MSR_PKGC6_IRTL, msr);
1338 	usec = irtl_2_usec(msr);
1339 	if (usec) {
1340 		bxt_cstates[2].exit_latency = usec;
1341 		bxt_cstates[2].target_residency = usec;
1342 	}
1343 
1344 	rdmsrl(MSR_PKGC7_IRTL, msr);
1345 	usec = irtl_2_usec(msr);
1346 	if (usec) {
1347 		bxt_cstates[3].exit_latency = usec;
1348 		bxt_cstates[3].target_residency = usec;
1349 	}
1350 
1351 	rdmsrl(MSR_PKGC8_IRTL, msr);
1352 	usec = irtl_2_usec(msr);
1353 	if (usec) {
1354 		bxt_cstates[4].exit_latency = usec;
1355 		bxt_cstates[4].target_residency = usec;
1356 	}
1357 
1358 	rdmsrl(MSR_PKGC9_IRTL, msr);
1359 	usec = irtl_2_usec(msr);
1360 	if (usec) {
1361 		bxt_cstates[5].exit_latency = usec;
1362 		bxt_cstates[5].target_residency = usec;
1363 	}
1364 
1365 	rdmsrl(MSR_PKGC10_IRTL, msr);
1366 	usec = irtl_2_usec(msr);
1367 	if (usec) {
1368 		bxt_cstates[6].exit_latency = usec;
1369 		bxt_cstates[6].target_residency = usec;
1370 	}
1371 
1372 }
1373 /*
1374  * sklh_idle_state_table_update(void)
1375  *
1376  * On SKL-H (model 0x5e) disable C8 and C9 if:
1377  * C10 is enabled and SGX disabled
1378  */
1379 static void __init sklh_idle_state_table_update(void)
1380 {
1381 	unsigned long long msr;
1382 	unsigned int eax, ebx, ecx, edx;
1383 
1384 
1385 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1386 	if (max_cstate <= 7)
1387 		return;
1388 
1389 	/* if PC10 not present in CPUID.MWAIT.EDX */
1390 	if ((mwait_substates & (0xF << 28)) == 0)
1391 		return;
1392 
1393 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1394 
1395 	/* PC10 is not enabled in PKG C-state limit */
1396 	if ((msr & 0xF) != 8)
1397 		return;
1398 
1399 	ecx = 0;
1400 	cpuid(7, &eax, &ebx, &ecx, &edx);
1401 
1402 	/* if SGX is present */
1403 	if (ebx & (1 << 2)) {
1404 
1405 		rdmsrl(MSR_IA32_FEAT_CTL, msr);
1406 
1407 		/* if SGX is enabled */
1408 		if (msr & (1 << 18))
1409 			return;
1410 	}
1411 
1412 	skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C8-SKL */
1413 	skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C9-SKL */
1414 }
1415 
1416 static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
1417 {
1418 	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
1419 	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
1420 					MWAIT_SUBSTATE_MASK;
1421 
1422 	/* Ignore the C-state if there are NO sub-states in CPUID for it. */
1423 	if (num_substates == 0)
1424 		return false;
1425 
1426 	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1427 		mark_tsc_unstable("TSC halts in idle states deeper than C2");
1428 
1429 	return true;
1430 }
1431 
1432 static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
1433 {
1434 	int cstate;
1435 
1436 	switch (boot_cpu_data.x86_model) {
1437 	case INTEL_FAM6_IVYBRIDGE_X:
1438 		ivt_idle_state_table_update();
1439 		break;
1440 	case INTEL_FAM6_ATOM_GOLDMONT:
1441 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1442 		bxt_idle_state_table_update();
1443 		break;
1444 	case INTEL_FAM6_SKYLAKE:
1445 		sklh_idle_state_table_update();
1446 		break;
1447 	}
1448 
1449 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1450 		unsigned int mwait_hint;
1451 
1452 		if (intel_idle_max_cstate_reached(cstate))
1453 			break;
1454 
1455 		if (!cpuidle_state_table[cstate].enter &&
1456 		    !cpuidle_state_table[cstate].enter_s2idle)
1457 			break;
1458 
1459 		/* If marked as unusable, skip this state. */
1460 		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
1461 			pr_debug("state %s is disabled\n",
1462 				 cpuidle_state_table[cstate].name);
1463 			continue;
1464 		}
1465 
1466 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1467 		if (!intel_idle_verify_cstate(mwait_hint))
1468 			continue;
1469 
1470 		/* Structure copy. */
1471 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
1472 
1473 		if ((disabled_states_mask & BIT(drv->state_count)) ||
1474 		    ((icpu->use_acpi || force_use_acpi) &&
1475 		     intel_idle_off_by_default(mwait_hint) &&
1476 		     !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE)))
1477 			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF;
1478 
1479 		drv->state_count++;
1480 	}
1481 
1482 	if (icpu->byt_auto_demotion_disable_flag) {
1483 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1484 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1485 	}
1486 }
1487 
1488 /*
1489  * intel_idle_cpuidle_driver_init()
1490  * allocate, initialize cpuidle_states
1491  */
1492 static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
1493 {
1494 	cpuidle_poll_state_init(drv);
1495 
1496 	if (disabled_states_mask & BIT(0))
1497 		drv->states[0].flags |= CPUIDLE_FLAG_OFF;
1498 
1499 	drv->state_count = 1;
1500 
1501 	if (icpu)
1502 		intel_idle_init_cstates_icpu(drv);
1503 	else
1504 		intel_idle_init_cstates_acpi(drv);
1505 }
1506 
1507 static void auto_demotion_disable(void)
1508 {
1509 	unsigned long long msr_bits;
1510 
1511 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1512 	msr_bits &= ~(icpu->auto_demotion_disable_flags);
1513 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
1514 }
1515 
1516 static void c1e_promotion_disable(void)
1517 {
1518 	unsigned long long msr_bits;
1519 
1520 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
1521 	msr_bits &= ~0x2;
1522 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
1523 }
1524 
1525 /*
1526  * intel_idle_cpu_init()
1527  * allocate, initialize, register cpuidle_devices
1528  * @cpu: cpu/core to initialize
1529  */
1530 static int intel_idle_cpu_init(unsigned int cpu)
1531 {
1532 	struct cpuidle_device *dev;
1533 
1534 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1535 	dev->cpu = cpu;
1536 
1537 	if (cpuidle_register_device(dev)) {
1538 		pr_debug("cpuidle_register_device %d failed!\n", cpu);
1539 		return -EIO;
1540 	}
1541 
1542 	if (!icpu)
1543 		return 0;
1544 
1545 	if (icpu->auto_demotion_disable_flags)
1546 		auto_demotion_disable();
1547 
1548 	if (icpu->disable_promotion_to_c1e)
1549 		c1e_promotion_disable();
1550 
1551 	return 0;
1552 }
1553 
1554 static int intel_idle_cpu_online(unsigned int cpu)
1555 {
1556 	struct cpuidle_device *dev;
1557 
1558 	if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
1559 		tick_broadcast_enable();
1560 
1561 	/*
1562 	 * Some systems can hotplug a cpu at runtime after
1563 	 * the kernel has booted, we have to initialize the
1564 	 * driver in this case
1565 	 */
1566 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1567 	if (!dev->registered)
1568 		return intel_idle_cpu_init(cpu);
1569 
1570 	return 0;
1571 }
1572 
1573 /**
1574  * intel_idle_cpuidle_devices_uninit - Unregister all cpuidle devices.
1575  */
1576 static void __init intel_idle_cpuidle_devices_uninit(void)
1577 {
1578 	int i;
1579 
1580 	for_each_online_cpu(i)
1581 		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
1582 }
1583 
1584 static int __init intel_idle_init(void)
1585 {
1586 	const struct x86_cpu_id *id;
1587 	unsigned int eax, ebx, ecx;
1588 	int retval;
1589 
1590 	/* Do not load intel_idle at all for now if idle= is passed */
1591 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1592 		return -ENODEV;
1593 
1594 	if (max_cstate == 0) {
1595 		pr_debug("disabled\n");
1596 		return -EPERM;
1597 	}
1598 
1599 	id = x86_match_cpu(intel_idle_ids);
1600 	if (id) {
1601 		if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1602 			pr_debug("Please enable MWAIT in BIOS SETUP\n");
1603 			return -ENODEV;
1604 		}
1605 	} else {
1606 		id = x86_match_cpu(intel_mwait_ids);
1607 		if (!id)
1608 			return -ENODEV;
1609 	}
1610 
1611 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1612 		return -ENODEV;
1613 
1614 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1615 
1616 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1617 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1618 	    !mwait_substates)
1619 			return -ENODEV;
1620 
1621 	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1622 
1623 	icpu = (const struct idle_cpu *)id->driver_data;
1624 	if (icpu) {
1625 		cpuidle_state_table = icpu->state_table;
1626 		if (icpu->use_acpi || force_use_acpi)
1627 			intel_idle_acpi_cst_extract();
1628 	} else if (!intel_idle_acpi_cst_extract()) {
1629 		return -ENODEV;
1630 	}
1631 
1632 	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1633 		 boot_cpu_data.x86_model);
1634 
1635 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1636 	if (!intel_idle_cpuidle_devices)
1637 		return -ENOMEM;
1638 
1639 	intel_idle_cpuidle_driver_init(&intel_idle_driver);
1640 
1641 	retval = cpuidle_register_driver(&intel_idle_driver);
1642 	if (retval) {
1643 		struct cpuidle_driver *drv = cpuidle_get_driver();
1644 		printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1645 		       drv ? drv->name : "none");
1646 		goto init_driver_fail;
1647 	}
1648 
1649 	if (boot_cpu_has(X86_FEATURE_ARAT))	/* Always Reliable APIC Timer */
1650 		lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
1651 
1652 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1653 				   intel_idle_cpu_online, NULL);
1654 	if (retval < 0)
1655 		goto hp_setup_fail;
1656 
1657 	pr_debug("lapic_timer_reliable_states 0x%x\n",
1658 		 lapic_timer_reliable_states);
1659 
1660 	return 0;
1661 
1662 hp_setup_fail:
1663 	intel_idle_cpuidle_devices_uninit();
1664 	cpuidle_unregister_driver(&intel_idle_driver);
1665 init_driver_fail:
1666 	free_percpu(intel_idle_cpuidle_devices);
1667 	return retval;
1668 
1669 }
1670 device_initcall(intel_idle_init);
1671 
1672 /*
1673  * We are not really modular, but we used to support that.  Meaning we also
1674  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1675  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1676  * is the easiest way (currently) to continue doing that.
1677  */
1678 module_param(max_cstate, int, 0444);
1679 /*
1680  * The positions of the bits that are set in this number are the indices of the
1681  * idle states to be disabled by default (as reflected by the names of the
1682  * corresponding idle state directories in sysfs, "state0", "state1" ...
1683  * "state<i>" ..., where <i> is the index of the given state).
1684  */
1685 module_param_named(states_off, disabled_states_mask, uint, 0444);
1686 MODULE_PARM_DESC(states_off, "Mask of disabled idle states");
1687