xref: /openbmc/linux/drivers/idle/intel_idle.c (revision 232b0b08)
1 /*
2  * intel_idle.c - native hardware idle loop for modern Intel processors
3  *
4  * Copyright (c) 2013, Intel Corporation.
5  * Len Brown <len.brown@intel.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 /*
22  * intel_idle is a cpuidle driver that loads on specific Intel processors
23  * in lieu of the legacy ACPI processor_idle driver.  The intent is to
24  * make Linux more efficient on these processors, as intel_idle knows
25  * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
26  */
27 
28 /*
29  * Design Assumptions
30  *
31  * All CPUs have same idle states as boot CPU
32  *
33  * Chipset BM_STS (bus master status) bit is a NOP
34  *	for preventing entry into deep C-stats
35  */
36 
37 /*
38  * Known limitations
39  *
40  * The driver currently initializes for_each_online_cpu() upon modprobe.
41  * It it unaware of subsequent processors hot-added to the system.
42  * This means that if you boot with maxcpus=n and later online
43  * processors above n, those processors will use C1 only.
44  *
45  * ACPI has a .suspend hack to turn off deep c-statees during suspend
46  * to avoid complications with the lapic timer workaround.
47  * Have not seen issues with suspend, but may need same workaround here.
48  *
49  */
50 
51 /* un-comment DEBUG to enable pr_debug() statements */
52 #define DEBUG
53 
54 #include <linux/kernel.h>
55 #include <linux/cpuidle.h>
56 #include <linux/tick.h>
57 #include <trace/events/power.h>
58 #include <linux/sched.h>
59 #include <linux/notifier.h>
60 #include <linux/cpu.h>
61 #include <linux/moduleparam.h>
62 #include <asm/cpu_device_id.h>
63 #include <asm/intel-family.h>
64 #include <asm/mwait.h>
65 #include <asm/msr.h>
66 
67 #define INTEL_IDLE_VERSION "0.4.1"
68 #define PREFIX "intel_idle: "
69 
70 static struct cpuidle_driver intel_idle_driver = {
71 	.name = "intel_idle",
72 	.owner = THIS_MODULE,
73 };
74 /* intel_idle.max_cstate=0 disables driver */
75 static int max_cstate = CPUIDLE_STATE_MAX - 1;
76 
77 static unsigned int mwait_substates;
78 
79 #define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
80 /* Reliable LAPIC Timer States, bit 1 for C1 etc.  */
81 static unsigned int lapic_timer_reliable_states = (1 << 1);	 /* Default to only C1 */
82 
83 struct idle_cpu {
84 	struct cpuidle_state *state_table;
85 
86 	/*
87 	 * Hardware C-state auto-demotion may not always be optimal.
88 	 * Indicate which enable bits to clear here.
89 	 */
90 	unsigned long auto_demotion_disable_flags;
91 	bool byt_auto_demotion_disable_flag;
92 	bool disable_promotion_to_c1e;
93 };
94 
95 static const struct idle_cpu *icpu;
96 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
97 static int intel_idle(struct cpuidle_device *dev,
98 			struct cpuidle_driver *drv, int index);
99 static void intel_idle_freeze(struct cpuidle_device *dev,
100 			      struct cpuidle_driver *drv, int index);
101 static struct cpuidle_state *cpuidle_state_table;
102 
103 /*
104  * Set this flag for states where the HW flushes the TLB for us
105  * and so we don't need cross-calls to keep it consistent.
106  * If this flag is set, SW flushes the TLB, so even if the
107  * HW doesn't do the flushing, this flag is safe to use.
108  */
109 #define CPUIDLE_FLAG_TLB_FLUSHED	0x10000
110 
111 /*
112  * MWAIT takes an 8-bit "hint" in EAX "suggesting"
113  * the C-state (top nibble) and sub-state (bottom nibble)
114  * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
115  *
116  * We store the hint at the top of our "flags" for each state.
117  */
118 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
119 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
120 
121 /*
122  * States are indexed by the cstate number,
123  * which is also the index into the MWAIT hint array.
124  * Thus C0 is a dummy.
125  */
126 static struct cpuidle_state nehalem_cstates[] = {
127 	{
128 		.name = "C1",
129 		.desc = "MWAIT 0x00",
130 		.flags = MWAIT2flg(0x00),
131 		.exit_latency = 3,
132 		.target_residency = 6,
133 		.enter = &intel_idle,
134 		.enter_freeze = intel_idle_freeze, },
135 	{
136 		.name = "C1E",
137 		.desc = "MWAIT 0x01",
138 		.flags = MWAIT2flg(0x01),
139 		.exit_latency = 10,
140 		.target_residency = 20,
141 		.enter = &intel_idle,
142 		.enter_freeze = intel_idle_freeze, },
143 	{
144 		.name = "C3",
145 		.desc = "MWAIT 0x10",
146 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
147 		.exit_latency = 20,
148 		.target_residency = 80,
149 		.enter = &intel_idle,
150 		.enter_freeze = intel_idle_freeze, },
151 	{
152 		.name = "C6",
153 		.desc = "MWAIT 0x20",
154 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
155 		.exit_latency = 200,
156 		.target_residency = 800,
157 		.enter = &intel_idle,
158 		.enter_freeze = intel_idle_freeze, },
159 	{
160 		.enter = NULL }
161 };
162 
163 static struct cpuidle_state snb_cstates[] = {
164 	{
165 		.name = "C1",
166 		.desc = "MWAIT 0x00",
167 		.flags = MWAIT2flg(0x00),
168 		.exit_latency = 2,
169 		.target_residency = 2,
170 		.enter = &intel_idle,
171 		.enter_freeze = intel_idle_freeze, },
172 	{
173 		.name = "C1E",
174 		.desc = "MWAIT 0x01",
175 		.flags = MWAIT2flg(0x01),
176 		.exit_latency = 10,
177 		.target_residency = 20,
178 		.enter = &intel_idle,
179 		.enter_freeze = intel_idle_freeze, },
180 	{
181 		.name = "C3",
182 		.desc = "MWAIT 0x10",
183 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
184 		.exit_latency = 80,
185 		.target_residency = 211,
186 		.enter = &intel_idle,
187 		.enter_freeze = intel_idle_freeze, },
188 	{
189 		.name = "C6",
190 		.desc = "MWAIT 0x20",
191 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
192 		.exit_latency = 104,
193 		.target_residency = 345,
194 		.enter = &intel_idle,
195 		.enter_freeze = intel_idle_freeze, },
196 	{
197 		.name = "C7",
198 		.desc = "MWAIT 0x30",
199 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
200 		.exit_latency = 109,
201 		.target_residency = 345,
202 		.enter = &intel_idle,
203 		.enter_freeze = intel_idle_freeze, },
204 	{
205 		.enter = NULL }
206 };
207 
208 static struct cpuidle_state byt_cstates[] = {
209 	{
210 		.name = "C1",
211 		.desc = "MWAIT 0x00",
212 		.flags = MWAIT2flg(0x00),
213 		.exit_latency = 1,
214 		.target_residency = 1,
215 		.enter = &intel_idle,
216 		.enter_freeze = intel_idle_freeze, },
217 	{
218 		.name = "C6N",
219 		.desc = "MWAIT 0x58",
220 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
221 		.exit_latency = 300,
222 		.target_residency = 275,
223 		.enter = &intel_idle,
224 		.enter_freeze = intel_idle_freeze, },
225 	{
226 		.name = "C6S",
227 		.desc = "MWAIT 0x52",
228 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
229 		.exit_latency = 500,
230 		.target_residency = 560,
231 		.enter = &intel_idle,
232 		.enter_freeze = intel_idle_freeze, },
233 	{
234 		.name = "C7",
235 		.desc = "MWAIT 0x60",
236 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
237 		.exit_latency = 1200,
238 		.target_residency = 4000,
239 		.enter = &intel_idle,
240 		.enter_freeze = intel_idle_freeze, },
241 	{
242 		.name = "C7S",
243 		.desc = "MWAIT 0x64",
244 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
245 		.exit_latency = 10000,
246 		.target_residency = 20000,
247 		.enter = &intel_idle,
248 		.enter_freeze = intel_idle_freeze, },
249 	{
250 		.enter = NULL }
251 };
252 
253 static struct cpuidle_state cht_cstates[] = {
254 	{
255 		.name = "C1",
256 		.desc = "MWAIT 0x00",
257 		.flags = MWAIT2flg(0x00),
258 		.exit_latency = 1,
259 		.target_residency = 1,
260 		.enter = &intel_idle,
261 		.enter_freeze = intel_idle_freeze, },
262 	{
263 		.name = "C6N",
264 		.desc = "MWAIT 0x58",
265 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
266 		.exit_latency = 80,
267 		.target_residency = 275,
268 		.enter = &intel_idle,
269 		.enter_freeze = intel_idle_freeze, },
270 	{
271 		.name = "C6S",
272 		.desc = "MWAIT 0x52",
273 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
274 		.exit_latency = 200,
275 		.target_residency = 560,
276 		.enter = &intel_idle,
277 		.enter_freeze = intel_idle_freeze, },
278 	{
279 		.name = "C7",
280 		.desc = "MWAIT 0x60",
281 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
282 		.exit_latency = 1200,
283 		.target_residency = 4000,
284 		.enter = &intel_idle,
285 		.enter_freeze = intel_idle_freeze, },
286 	{
287 		.name = "C7S",
288 		.desc = "MWAIT 0x64",
289 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
290 		.exit_latency = 10000,
291 		.target_residency = 20000,
292 		.enter = &intel_idle,
293 		.enter_freeze = intel_idle_freeze, },
294 	{
295 		.enter = NULL }
296 };
297 
298 static struct cpuidle_state ivb_cstates[] = {
299 	{
300 		.name = "C1",
301 		.desc = "MWAIT 0x00",
302 		.flags = MWAIT2flg(0x00),
303 		.exit_latency = 1,
304 		.target_residency = 1,
305 		.enter = &intel_idle,
306 		.enter_freeze = intel_idle_freeze, },
307 	{
308 		.name = "C1E",
309 		.desc = "MWAIT 0x01",
310 		.flags = MWAIT2flg(0x01),
311 		.exit_latency = 10,
312 		.target_residency = 20,
313 		.enter = &intel_idle,
314 		.enter_freeze = intel_idle_freeze, },
315 	{
316 		.name = "C3",
317 		.desc = "MWAIT 0x10",
318 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
319 		.exit_latency = 59,
320 		.target_residency = 156,
321 		.enter = &intel_idle,
322 		.enter_freeze = intel_idle_freeze, },
323 	{
324 		.name = "C6",
325 		.desc = "MWAIT 0x20",
326 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
327 		.exit_latency = 80,
328 		.target_residency = 300,
329 		.enter = &intel_idle,
330 		.enter_freeze = intel_idle_freeze, },
331 	{
332 		.name = "C7",
333 		.desc = "MWAIT 0x30",
334 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
335 		.exit_latency = 87,
336 		.target_residency = 300,
337 		.enter = &intel_idle,
338 		.enter_freeze = intel_idle_freeze, },
339 	{
340 		.enter = NULL }
341 };
342 
343 static struct cpuidle_state ivt_cstates[] = {
344 	{
345 		.name = "C1",
346 		.desc = "MWAIT 0x00",
347 		.flags = MWAIT2flg(0x00),
348 		.exit_latency = 1,
349 		.target_residency = 1,
350 		.enter = &intel_idle,
351 		.enter_freeze = intel_idle_freeze, },
352 	{
353 		.name = "C1E",
354 		.desc = "MWAIT 0x01",
355 		.flags = MWAIT2flg(0x01),
356 		.exit_latency = 10,
357 		.target_residency = 80,
358 		.enter = &intel_idle,
359 		.enter_freeze = intel_idle_freeze, },
360 	{
361 		.name = "C3",
362 		.desc = "MWAIT 0x10",
363 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
364 		.exit_latency = 59,
365 		.target_residency = 156,
366 		.enter = &intel_idle,
367 		.enter_freeze = intel_idle_freeze, },
368 	{
369 		.name = "C6",
370 		.desc = "MWAIT 0x20",
371 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
372 		.exit_latency = 82,
373 		.target_residency = 300,
374 		.enter = &intel_idle,
375 		.enter_freeze = intel_idle_freeze, },
376 	{
377 		.enter = NULL }
378 };
379 
380 static struct cpuidle_state ivt_cstates_4s[] = {
381 	{
382 		.name = "C1",
383 		.desc = "MWAIT 0x00",
384 		.flags = MWAIT2flg(0x00),
385 		.exit_latency = 1,
386 		.target_residency = 1,
387 		.enter = &intel_idle,
388 		.enter_freeze = intel_idle_freeze, },
389 	{
390 		.name = "C1E",
391 		.desc = "MWAIT 0x01",
392 		.flags = MWAIT2flg(0x01),
393 		.exit_latency = 10,
394 		.target_residency = 250,
395 		.enter = &intel_idle,
396 		.enter_freeze = intel_idle_freeze, },
397 	{
398 		.name = "C3",
399 		.desc = "MWAIT 0x10",
400 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
401 		.exit_latency = 59,
402 		.target_residency = 300,
403 		.enter = &intel_idle,
404 		.enter_freeze = intel_idle_freeze, },
405 	{
406 		.name = "C6",
407 		.desc = "MWAIT 0x20",
408 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
409 		.exit_latency = 84,
410 		.target_residency = 400,
411 		.enter = &intel_idle,
412 		.enter_freeze = intel_idle_freeze, },
413 	{
414 		.enter = NULL }
415 };
416 
417 static struct cpuidle_state ivt_cstates_8s[] = {
418 	{
419 		.name = "C1",
420 		.desc = "MWAIT 0x00",
421 		.flags = MWAIT2flg(0x00),
422 		.exit_latency = 1,
423 		.target_residency = 1,
424 		.enter = &intel_idle,
425 		.enter_freeze = intel_idle_freeze, },
426 	{
427 		.name = "C1E",
428 		.desc = "MWAIT 0x01",
429 		.flags = MWAIT2flg(0x01),
430 		.exit_latency = 10,
431 		.target_residency = 500,
432 		.enter = &intel_idle,
433 		.enter_freeze = intel_idle_freeze, },
434 	{
435 		.name = "C3",
436 		.desc = "MWAIT 0x10",
437 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
438 		.exit_latency = 59,
439 		.target_residency = 600,
440 		.enter = &intel_idle,
441 		.enter_freeze = intel_idle_freeze, },
442 	{
443 		.name = "C6",
444 		.desc = "MWAIT 0x20",
445 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
446 		.exit_latency = 88,
447 		.target_residency = 700,
448 		.enter = &intel_idle,
449 		.enter_freeze = intel_idle_freeze, },
450 	{
451 		.enter = NULL }
452 };
453 
454 static struct cpuidle_state hsw_cstates[] = {
455 	{
456 		.name = "C1",
457 		.desc = "MWAIT 0x00",
458 		.flags = MWAIT2flg(0x00),
459 		.exit_latency = 2,
460 		.target_residency = 2,
461 		.enter = &intel_idle,
462 		.enter_freeze = intel_idle_freeze, },
463 	{
464 		.name = "C1E",
465 		.desc = "MWAIT 0x01",
466 		.flags = MWAIT2flg(0x01),
467 		.exit_latency = 10,
468 		.target_residency = 20,
469 		.enter = &intel_idle,
470 		.enter_freeze = intel_idle_freeze, },
471 	{
472 		.name = "C3",
473 		.desc = "MWAIT 0x10",
474 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
475 		.exit_latency = 33,
476 		.target_residency = 100,
477 		.enter = &intel_idle,
478 		.enter_freeze = intel_idle_freeze, },
479 	{
480 		.name = "C6",
481 		.desc = "MWAIT 0x20",
482 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
483 		.exit_latency = 133,
484 		.target_residency = 400,
485 		.enter = &intel_idle,
486 		.enter_freeze = intel_idle_freeze, },
487 	{
488 		.name = "C7s",
489 		.desc = "MWAIT 0x32",
490 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
491 		.exit_latency = 166,
492 		.target_residency = 500,
493 		.enter = &intel_idle,
494 		.enter_freeze = intel_idle_freeze, },
495 	{
496 		.name = "C8",
497 		.desc = "MWAIT 0x40",
498 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
499 		.exit_latency = 300,
500 		.target_residency = 900,
501 		.enter = &intel_idle,
502 		.enter_freeze = intel_idle_freeze, },
503 	{
504 		.name = "C9",
505 		.desc = "MWAIT 0x50",
506 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
507 		.exit_latency = 600,
508 		.target_residency = 1800,
509 		.enter = &intel_idle,
510 		.enter_freeze = intel_idle_freeze, },
511 	{
512 		.name = "C10",
513 		.desc = "MWAIT 0x60",
514 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
515 		.exit_latency = 2600,
516 		.target_residency = 7700,
517 		.enter = &intel_idle,
518 		.enter_freeze = intel_idle_freeze, },
519 	{
520 		.enter = NULL }
521 };
522 static struct cpuidle_state bdw_cstates[] = {
523 	{
524 		.name = "C1",
525 		.desc = "MWAIT 0x00",
526 		.flags = MWAIT2flg(0x00),
527 		.exit_latency = 2,
528 		.target_residency = 2,
529 		.enter = &intel_idle,
530 		.enter_freeze = intel_idle_freeze, },
531 	{
532 		.name = "C1E",
533 		.desc = "MWAIT 0x01",
534 		.flags = MWAIT2flg(0x01),
535 		.exit_latency = 10,
536 		.target_residency = 20,
537 		.enter = &intel_idle,
538 		.enter_freeze = intel_idle_freeze, },
539 	{
540 		.name = "C3",
541 		.desc = "MWAIT 0x10",
542 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
543 		.exit_latency = 40,
544 		.target_residency = 100,
545 		.enter = &intel_idle,
546 		.enter_freeze = intel_idle_freeze, },
547 	{
548 		.name = "C6",
549 		.desc = "MWAIT 0x20",
550 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
551 		.exit_latency = 133,
552 		.target_residency = 400,
553 		.enter = &intel_idle,
554 		.enter_freeze = intel_idle_freeze, },
555 	{
556 		.name = "C7s",
557 		.desc = "MWAIT 0x32",
558 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
559 		.exit_latency = 166,
560 		.target_residency = 500,
561 		.enter = &intel_idle,
562 		.enter_freeze = intel_idle_freeze, },
563 	{
564 		.name = "C8",
565 		.desc = "MWAIT 0x40",
566 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
567 		.exit_latency = 300,
568 		.target_residency = 900,
569 		.enter = &intel_idle,
570 		.enter_freeze = intel_idle_freeze, },
571 	{
572 		.name = "C9",
573 		.desc = "MWAIT 0x50",
574 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
575 		.exit_latency = 600,
576 		.target_residency = 1800,
577 		.enter = &intel_idle,
578 		.enter_freeze = intel_idle_freeze, },
579 	{
580 		.name = "C10",
581 		.desc = "MWAIT 0x60",
582 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
583 		.exit_latency = 2600,
584 		.target_residency = 7700,
585 		.enter = &intel_idle,
586 		.enter_freeze = intel_idle_freeze, },
587 	{
588 		.enter = NULL }
589 };
590 
591 static struct cpuidle_state skl_cstates[] = {
592 	{
593 		.name = "C1",
594 		.desc = "MWAIT 0x00",
595 		.flags = MWAIT2flg(0x00),
596 		.exit_latency = 2,
597 		.target_residency = 2,
598 		.enter = &intel_idle,
599 		.enter_freeze = intel_idle_freeze, },
600 	{
601 		.name = "C1E",
602 		.desc = "MWAIT 0x01",
603 		.flags = MWAIT2flg(0x01),
604 		.exit_latency = 10,
605 		.target_residency = 20,
606 		.enter = &intel_idle,
607 		.enter_freeze = intel_idle_freeze, },
608 	{
609 		.name = "C3",
610 		.desc = "MWAIT 0x10",
611 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
612 		.exit_latency = 70,
613 		.target_residency = 100,
614 		.enter = &intel_idle,
615 		.enter_freeze = intel_idle_freeze, },
616 	{
617 		.name = "C6",
618 		.desc = "MWAIT 0x20",
619 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
620 		.exit_latency = 85,
621 		.target_residency = 200,
622 		.enter = &intel_idle,
623 		.enter_freeze = intel_idle_freeze, },
624 	{
625 		.name = "C7s",
626 		.desc = "MWAIT 0x33",
627 		.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
628 		.exit_latency = 124,
629 		.target_residency = 800,
630 		.enter = &intel_idle,
631 		.enter_freeze = intel_idle_freeze, },
632 	{
633 		.name = "C8",
634 		.desc = "MWAIT 0x40",
635 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
636 		.exit_latency = 200,
637 		.target_residency = 800,
638 		.enter = &intel_idle,
639 		.enter_freeze = intel_idle_freeze, },
640 	{
641 		.name = "C9",
642 		.desc = "MWAIT 0x50",
643 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
644 		.exit_latency = 480,
645 		.target_residency = 5000,
646 		.enter = &intel_idle,
647 		.enter_freeze = intel_idle_freeze, },
648 	{
649 		.name = "C10",
650 		.desc = "MWAIT 0x60",
651 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
652 		.exit_latency = 890,
653 		.target_residency = 5000,
654 		.enter = &intel_idle,
655 		.enter_freeze = intel_idle_freeze, },
656 	{
657 		.enter = NULL }
658 };
659 
660 static struct cpuidle_state skx_cstates[] = {
661 	{
662 		.name = "C1",
663 		.desc = "MWAIT 0x00",
664 		.flags = MWAIT2flg(0x00),
665 		.exit_latency = 2,
666 		.target_residency = 2,
667 		.enter = &intel_idle,
668 		.enter_freeze = intel_idle_freeze, },
669 	{
670 		.name = "C1E",
671 		.desc = "MWAIT 0x01",
672 		.flags = MWAIT2flg(0x01),
673 		.exit_latency = 10,
674 		.target_residency = 20,
675 		.enter = &intel_idle,
676 		.enter_freeze = intel_idle_freeze, },
677 	{
678 		.name = "C6",
679 		.desc = "MWAIT 0x20",
680 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
681 		.exit_latency = 133,
682 		.target_residency = 600,
683 		.enter = &intel_idle,
684 		.enter_freeze = intel_idle_freeze, },
685 	{
686 		.enter = NULL }
687 };
688 
689 static struct cpuidle_state atom_cstates[] = {
690 	{
691 		.name = "C1E",
692 		.desc = "MWAIT 0x00",
693 		.flags = MWAIT2flg(0x00),
694 		.exit_latency = 10,
695 		.target_residency = 20,
696 		.enter = &intel_idle,
697 		.enter_freeze = intel_idle_freeze, },
698 	{
699 		.name = "C2",
700 		.desc = "MWAIT 0x10",
701 		.flags = MWAIT2flg(0x10),
702 		.exit_latency = 20,
703 		.target_residency = 80,
704 		.enter = &intel_idle,
705 		.enter_freeze = intel_idle_freeze, },
706 	{
707 		.name = "C4",
708 		.desc = "MWAIT 0x30",
709 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
710 		.exit_latency = 100,
711 		.target_residency = 400,
712 		.enter = &intel_idle,
713 		.enter_freeze = intel_idle_freeze, },
714 	{
715 		.name = "C6",
716 		.desc = "MWAIT 0x52",
717 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
718 		.exit_latency = 140,
719 		.target_residency = 560,
720 		.enter = &intel_idle,
721 		.enter_freeze = intel_idle_freeze, },
722 	{
723 		.enter = NULL }
724 };
725 static struct cpuidle_state tangier_cstates[] = {
726 	{
727 		.name = "C1",
728 		.desc = "MWAIT 0x00",
729 		.flags = MWAIT2flg(0x00),
730 		.exit_latency = 1,
731 		.target_residency = 4,
732 		.enter = &intel_idle,
733 		.enter_freeze = intel_idle_freeze, },
734 	{
735 		.name = "C4",
736 		.desc = "MWAIT 0x30",
737 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
738 		.exit_latency = 100,
739 		.target_residency = 400,
740 		.enter = &intel_idle,
741 		.enter_freeze = intel_idle_freeze, },
742 	{
743 		.name = "C6",
744 		.desc = "MWAIT 0x52",
745 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
746 		.exit_latency = 140,
747 		.target_residency = 560,
748 		.enter = &intel_idle,
749 		.enter_freeze = intel_idle_freeze, },
750 	{
751 		.name = "C7",
752 		.desc = "MWAIT 0x60",
753 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
754 		.exit_latency = 1200,
755 		.target_residency = 4000,
756 		.enter = &intel_idle,
757 		.enter_freeze = intel_idle_freeze, },
758 	{
759 		.name = "C9",
760 		.desc = "MWAIT 0x64",
761 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
762 		.exit_latency = 10000,
763 		.target_residency = 20000,
764 		.enter = &intel_idle,
765 		.enter_freeze = intel_idle_freeze, },
766 	{
767 		.enter = NULL }
768 };
769 static struct cpuidle_state avn_cstates[] = {
770 	{
771 		.name = "C1",
772 		.desc = "MWAIT 0x00",
773 		.flags = MWAIT2flg(0x00),
774 		.exit_latency = 2,
775 		.target_residency = 2,
776 		.enter = &intel_idle,
777 		.enter_freeze = intel_idle_freeze, },
778 	{
779 		.name = "C6",
780 		.desc = "MWAIT 0x51",
781 		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
782 		.exit_latency = 15,
783 		.target_residency = 45,
784 		.enter = &intel_idle,
785 		.enter_freeze = intel_idle_freeze, },
786 	{
787 		.enter = NULL }
788 };
789 static struct cpuidle_state knl_cstates[] = {
790 	{
791 		.name = "C1",
792 		.desc = "MWAIT 0x00",
793 		.flags = MWAIT2flg(0x00),
794 		.exit_latency = 1,
795 		.target_residency = 2,
796 		.enter = &intel_idle,
797 		.enter_freeze = intel_idle_freeze },
798 	{
799 		.name = "C6",
800 		.desc = "MWAIT 0x10",
801 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
802 		.exit_latency = 120,
803 		.target_residency = 500,
804 		.enter = &intel_idle,
805 		.enter_freeze = intel_idle_freeze },
806 	{
807 		.enter = NULL }
808 };
809 
810 static struct cpuidle_state bxt_cstates[] = {
811 	{
812 		.name = "C1",
813 		.desc = "MWAIT 0x00",
814 		.flags = MWAIT2flg(0x00),
815 		.exit_latency = 2,
816 		.target_residency = 2,
817 		.enter = &intel_idle,
818 		.enter_freeze = intel_idle_freeze, },
819 	{
820 		.name = "C1E",
821 		.desc = "MWAIT 0x01",
822 		.flags = MWAIT2flg(0x01),
823 		.exit_latency = 10,
824 		.target_residency = 20,
825 		.enter = &intel_idle,
826 		.enter_freeze = intel_idle_freeze, },
827 	{
828 		.name = "C6",
829 		.desc = "MWAIT 0x20",
830 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
831 		.exit_latency = 133,
832 		.target_residency = 133,
833 		.enter = &intel_idle,
834 		.enter_freeze = intel_idle_freeze, },
835 	{
836 		.name = "C7s",
837 		.desc = "MWAIT 0x31",
838 		.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
839 		.exit_latency = 155,
840 		.target_residency = 155,
841 		.enter = &intel_idle,
842 		.enter_freeze = intel_idle_freeze, },
843 	{
844 		.name = "C8",
845 		.desc = "MWAIT 0x40",
846 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
847 		.exit_latency = 1000,
848 		.target_residency = 1000,
849 		.enter = &intel_idle,
850 		.enter_freeze = intel_idle_freeze, },
851 	{
852 		.name = "C9",
853 		.desc = "MWAIT 0x50",
854 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
855 		.exit_latency = 2000,
856 		.target_residency = 2000,
857 		.enter = &intel_idle,
858 		.enter_freeze = intel_idle_freeze, },
859 	{
860 		.name = "C10",
861 		.desc = "MWAIT 0x60",
862 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
863 		.exit_latency = 10000,
864 		.target_residency = 10000,
865 		.enter = &intel_idle,
866 		.enter_freeze = intel_idle_freeze, },
867 	{
868 		.enter = NULL }
869 };
870 
871 static struct cpuidle_state dnv_cstates[] = {
872 	{
873 		.name = "C1",
874 		.desc = "MWAIT 0x00",
875 		.flags = MWAIT2flg(0x00),
876 		.exit_latency = 2,
877 		.target_residency = 2,
878 		.enter = &intel_idle,
879 		.enter_freeze = intel_idle_freeze, },
880 	{
881 		.name = "C1E",
882 		.desc = "MWAIT 0x01",
883 		.flags = MWAIT2flg(0x01),
884 		.exit_latency = 10,
885 		.target_residency = 20,
886 		.enter = &intel_idle,
887 		.enter_freeze = intel_idle_freeze, },
888 	{
889 		.name = "C6",
890 		.desc = "MWAIT 0x20",
891 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
892 		.exit_latency = 50,
893 		.target_residency = 500,
894 		.enter = &intel_idle,
895 		.enter_freeze = intel_idle_freeze, },
896 	{
897 		.enter = NULL }
898 };
899 
900 /**
901  * intel_idle
902  * @dev: cpuidle_device
903  * @drv: cpuidle driver
904  * @index: index of cpuidle state
905  *
906  * Must be called under local_irq_disable().
907  */
908 static __cpuidle int intel_idle(struct cpuidle_device *dev,
909 				struct cpuidle_driver *drv, int index)
910 {
911 	unsigned long ecx = 1; /* break on interrupt flag */
912 	struct cpuidle_state *state = &drv->states[index];
913 	unsigned long eax = flg2MWAIT(state->flags);
914 	unsigned int cstate;
915 	int cpu = smp_processor_id();
916 
917 	cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
918 
919 	/*
920 	 * leave_mm() to avoid costly and often unnecessary wakeups
921 	 * for flushing the user TLB's associated with the active mm.
922 	 */
923 	if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
924 		leave_mm(cpu);
925 
926 	if (!(lapic_timer_reliable_states & (1 << (cstate))))
927 		tick_broadcast_enter();
928 
929 	mwait_idle_with_hints(eax, ecx);
930 
931 	if (!(lapic_timer_reliable_states & (1 << (cstate))))
932 		tick_broadcast_exit();
933 
934 	return index;
935 }
936 
937 /**
938  * intel_idle_freeze - simplified "enter" callback routine for suspend-to-idle
939  * @dev: cpuidle_device
940  * @drv: cpuidle driver
941  * @index: state index
942  */
943 static void intel_idle_freeze(struct cpuidle_device *dev,
944 			     struct cpuidle_driver *drv, int index)
945 {
946 	unsigned long ecx = 1; /* break on interrupt flag */
947 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
948 
949 	mwait_idle_with_hints(eax, ecx);
950 }
951 
952 static void __setup_broadcast_timer(bool on)
953 {
954 	if (on)
955 		tick_broadcast_enable();
956 	else
957 		tick_broadcast_disable();
958 }
959 
960 static void auto_demotion_disable(void)
961 {
962 	unsigned long long msr_bits;
963 
964 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
965 	msr_bits &= ~(icpu->auto_demotion_disable_flags);
966 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
967 }
968 static void c1e_promotion_disable(void)
969 {
970 	unsigned long long msr_bits;
971 
972 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
973 	msr_bits &= ~0x2;
974 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
975 }
976 
977 static const struct idle_cpu idle_cpu_nehalem = {
978 	.state_table = nehalem_cstates,
979 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
980 	.disable_promotion_to_c1e = true,
981 };
982 
983 static const struct idle_cpu idle_cpu_atom = {
984 	.state_table = atom_cstates,
985 };
986 
987 static const struct idle_cpu idle_cpu_tangier = {
988 	.state_table = tangier_cstates,
989 };
990 
991 static const struct idle_cpu idle_cpu_lincroft = {
992 	.state_table = atom_cstates,
993 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
994 };
995 
996 static const struct idle_cpu idle_cpu_snb = {
997 	.state_table = snb_cstates,
998 	.disable_promotion_to_c1e = true,
999 };
1000 
1001 static const struct idle_cpu idle_cpu_byt = {
1002 	.state_table = byt_cstates,
1003 	.disable_promotion_to_c1e = true,
1004 	.byt_auto_demotion_disable_flag = true,
1005 };
1006 
1007 static const struct idle_cpu idle_cpu_cht = {
1008 	.state_table = cht_cstates,
1009 	.disable_promotion_to_c1e = true,
1010 	.byt_auto_demotion_disable_flag = true,
1011 };
1012 
1013 static const struct idle_cpu idle_cpu_ivb = {
1014 	.state_table = ivb_cstates,
1015 	.disable_promotion_to_c1e = true,
1016 };
1017 
1018 static const struct idle_cpu idle_cpu_ivt = {
1019 	.state_table = ivt_cstates,
1020 	.disable_promotion_to_c1e = true,
1021 };
1022 
1023 static const struct idle_cpu idle_cpu_hsw = {
1024 	.state_table = hsw_cstates,
1025 	.disable_promotion_to_c1e = true,
1026 };
1027 
1028 static const struct idle_cpu idle_cpu_bdw = {
1029 	.state_table = bdw_cstates,
1030 	.disable_promotion_to_c1e = true,
1031 };
1032 
1033 static const struct idle_cpu idle_cpu_skl = {
1034 	.state_table = skl_cstates,
1035 	.disable_promotion_to_c1e = true,
1036 };
1037 
1038 static const struct idle_cpu idle_cpu_skx = {
1039 	.state_table = skx_cstates,
1040 	.disable_promotion_to_c1e = true,
1041 };
1042 
1043 static const struct idle_cpu idle_cpu_avn = {
1044 	.state_table = avn_cstates,
1045 	.disable_promotion_to_c1e = true,
1046 };
1047 
1048 static const struct idle_cpu idle_cpu_knl = {
1049 	.state_table = knl_cstates,
1050 };
1051 
1052 static const struct idle_cpu idle_cpu_bxt = {
1053 	.state_table = bxt_cstates,
1054 	.disable_promotion_to_c1e = true,
1055 };
1056 
1057 static const struct idle_cpu idle_cpu_dnv = {
1058 	.state_table = dnv_cstates,
1059 	.disable_promotion_to_c1e = true,
1060 };
1061 
1062 #define ICPU(model, cpu) \
1063 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
1064 
1065 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1066 	ICPU(INTEL_FAM6_NEHALEM_EP,		idle_cpu_nehalem),
1067 	ICPU(INTEL_FAM6_NEHALEM,		idle_cpu_nehalem),
1068 	ICPU(INTEL_FAM6_NEHALEM_G,		idle_cpu_nehalem),
1069 	ICPU(INTEL_FAM6_WESTMERE,		idle_cpu_nehalem),
1070 	ICPU(INTEL_FAM6_WESTMERE_EP,		idle_cpu_nehalem),
1071 	ICPU(INTEL_FAM6_NEHALEM_EX,		idle_cpu_nehalem),
1072 	ICPU(INTEL_FAM6_ATOM_PINEVIEW,		idle_cpu_atom),
1073 	ICPU(INTEL_FAM6_ATOM_LINCROFT,		idle_cpu_lincroft),
1074 	ICPU(INTEL_FAM6_WESTMERE_EX,		idle_cpu_nehalem),
1075 	ICPU(INTEL_FAM6_SANDYBRIDGE,		idle_cpu_snb),
1076 	ICPU(INTEL_FAM6_SANDYBRIDGE_X,		idle_cpu_snb),
1077 	ICPU(INTEL_FAM6_ATOM_CEDARVIEW,		idle_cpu_atom),
1078 	ICPU(INTEL_FAM6_ATOM_SILVERMONT1,	idle_cpu_byt),
1079 	ICPU(INTEL_FAM6_ATOM_MERRIFIELD,	idle_cpu_tangier),
1080 	ICPU(INTEL_FAM6_ATOM_AIRMONT,		idle_cpu_cht),
1081 	ICPU(INTEL_FAM6_IVYBRIDGE,		idle_cpu_ivb),
1082 	ICPU(INTEL_FAM6_IVYBRIDGE_X,		idle_cpu_ivt),
1083 	ICPU(INTEL_FAM6_HASWELL_CORE,		idle_cpu_hsw),
1084 	ICPU(INTEL_FAM6_HASWELL_X,		idle_cpu_hsw),
1085 	ICPU(INTEL_FAM6_HASWELL_ULT,		idle_cpu_hsw),
1086 	ICPU(INTEL_FAM6_HASWELL_GT3E,		idle_cpu_hsw),
1087 	ICPU(INTEL_FAM6_ATOM_SILVERMONT2,	idle_cpu_avn),
1088 	ICPU(INTEL_FAM6_BROADWELL_CORE,		idle_cpu_bdw),
1089 	ICPU(INTEL_FAM6_BROADWELL_GT3E,		idle_cpu_bdw),
1090 	ICPU(INTEL_FAM6_BROADWELL_X,		idle_cpu_bdw),
1091 	ICPU(INTEL_FAM6_BROADWELL_XEON_D,	idle_cpu_bdw),
1092 	ICPU(INTEL_FAM6_SKYLAKE_MOBILE,		idle_cpu_skl),
1093 	ICPU(INTEL_FAM6_SKYLAKE_DESKTOP,	idle_cpu_skl),
1094 	ICPU(INTEL_FAM6_KABYLAKE_MOBILE,	idle_cpu_skl),
1095 	ICPU(INTEL_FAM6_KABYLAKE_DESKTOP,	idle_cpu_skl),
1096 	ICPU(INTEL_FAM6_SKYLAKE_X,		idle_cpu_skx),
1097 	ICPU(INTEL_FAM6_XEON_PHI_KNL,		idle_cpu_knl),
1098 	ICPU(INTEL_FAM6_XEON_PHI_KNM,		idle_cpu_knl),
1099 	ICPU(INTEL_FAM6_ATOM_GOLDMONT,		idle_cpu_bxt),
1100 	ICPU(INTEL_FAM6_ATOM_DENVERTON,		idle_cpu_dnv),
1101 	{}
1102 };
1103 
1104 /*
1105  * intel_idle_probe()
1106  */
1107 static int __init intel_idle_probe(void)
1108 {
1109 	unsigned int eax, ebx, ecx;
1110 	const struct x86_cpu_id *id;
1111 
1112 	if (max_cstate == 0) {
1113 		pr_debug(PREFIX "disabled\n");
1114 		return -EPERM;
1115 	}
1116 
1117 	id = x86_match_cpu(intel_idle_ids);
1118 	if (!id) {
1119 		if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
1120 		    boot_cpu_data.x86 == 6)
1121 			pr_debug(PREFIX "does not run on family %d model %d\n",
1122 				boot_cpu_data.x86, boot_cpu_data.x86_model);
1123 		return -ENODEV;
1124 	}
1125 
1126 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1127 		return -ENODEV;
1128 
1129 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1130 
1131 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1132 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1133 	    !mwait_substates)
1134 			return -ENODEV;
1135 
1136 	pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
1137 
1138 	icpu = (const struct idle_cpu *)id->driver_data;
1139 	cpuidle_state_table = icpu->state_table;
1140 
1141 	pr_debug(PREFIX "v" INTEL_IDLE_VERSION
1142 		" model 0x%X\n", boot_cpu_data.x86_model);
1143 
1144 	return 0;
1145 }
1146 
1147 /*
1148  * intel_idle_cpuidle_devices_uninit()
1149  * Unregisters the cpuidle devices.
1150  */
1151 static void intel_idle_cpuidle_devices_uninit(void)
1152 {
1153 	int i;
1154 	struct cpuidle_device *dev;
1155 
1156 	for_each_online_cpu(i) {
1157 		dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1158 		cpuidle_unregister_device(dev);
1159 	}
1160 }
1161 
1162 /*
1163  * ivt_idle_state_table_update(void)
1164  *
1165  * Tune IVT multi-socket targets
1166  * Assumption: num_sockets == (max_package_num + 1)
1167  */
1168 static void ivt_idle_state_table_update(void)
1169 {
1170 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1171 	int cpu, package_num, num_sockets = 1;
1172 
1173 	for_each_online_cpu(cpu) {
1174 		package_num = topology_physical_package_id(cpu);
1175 		if (package_num + 1 > num_sockets) {
1176 			num_sockets = package_num + 1;
1177 
1178 			if (num_sockets > 4) {
1179 				cpuidle_state_table = ivt_cstates_8s;
1180 				return;
1181 			}
1182 		}
1183 	}
1184 
1185 	if (num_sockets > 2)
1186 		cpuidle_state_table = ivt_cstates_4s;
1187 
1188 	/* else, 1 and 2 socket systems use default ivt_cstates */
1189 }
1190 
1191 /*
1192  * Translate IRTL (Interrupt Response Time Limit) MSR to usec
1193  */
1194 
1195 static unsigned int irtl_ns_units[] = {
1196 	1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
1197 
1198 static unsigned long long irtl_2_usec(unsigned long long irtl)
1199 {
1200 	unsigned long long ns;
1201 
1202 	if (!irtl)
1203 		return 0;
1204 
1205 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1206 
1207 	return div64_u64((irtl & 0x3FF) * ns, 1000);
1208 }
1209 /*
1210  * bxt_idle_state_table_update(void)
1211  *
1212  * On BXT, we trust the IRTL to show the definitive maximum latency
1213  * We use the same value for target_residency.
1214  */
1215 static void bxt_idle_state_table_update(void)
1216 {
1217 	unsigned long long msr;
1218 	unsigned int usec;
1219 
1220 	rdmsrl(MSR_PKGC6_IRTL, msr);
1221 	usec = irtl_2_usec(msr);
1222 	if (usec) {
1223 		bxt_cstates[2].exit_latency = usec;
1224 		bxt_cstates[2].target_residency = usec;
1225 	}
1226 
1227 	rdmsrl(MSR_PKGC7_IRTL, msr);
1228 	usec = irtl_2_usec(msr);
1229 	if (usec) {
1230 		bxt_cstates[3].exit_latency = usec;
1231 		bxt_cstates[3].target_residency = usec;
1232 	}
1233 
1234 	rdmsrl(MSR_PKGC8_IRTL, msr);
1235 	usec = irtl_2_usec(msr);
1236 	if (usec) {
1237 		bxt_cstates[4].exit_latency = usec;
1238 		bxt_cstates[4].target_residency = usec;
1239 	}
1240 
1241 	rdmsrl(MSR_PKGC9_IRTL, msr);
1242 	usec = irtl_2_usec(msr);
1243 	if (usec) {
1244 		bxt_cstates[5].exit_latency = usec;
1245 		bxt_cstates[5].target_residency = usec;
1246 	}
1247 
1248 	rdmsrl(MSR_PKGC10_IRTL, msr);
1249 	usec = irtl_2_usec(msr);
1250 	if (usec) {
1251 		bxt_cstates[6].exit_latency = usec;
1252 		bxt_cstates[6].target_residency = usec;
1253 	}
1254 
1255 }
1256 /*
1257  * sklh_idle_state_table_update(void)
1258  *
1259  * On SKL-H (model 0x5e) disable C8 and C9 if:
1260  * C10 is enabled and SGX disabled
1261  */
1262 static void sklh_idle_state_table_update(void)
1263 {
1264 	unsigned long long msr;
1265 	unsigned int eax, ebx, ecx, edx;
1266 
1267 
1268 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1269 	if (max_cstate <= 7)
1270 		return;
1271 
1272 	/* if PC10 not present in CPUID.MWAIT.EDX */
1273 	if ((mwait_substates & (0xF << 28)) == 0)
1274 		return;
1275 
1276 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1277 
1278 	/* PC10 is not enabled in PKG C-state limit */
1279 	if ((msr & 0xF) != 8)
1280 		return;
1281 
1282 	ecx = 0;
1283 	cpuid(7, &eax, &ebx, &ecx, &edx);
1284 
1285 	/* if SGX is present */
1286 	if (ebx & (1 << 2)) {
1287 
1288 		rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
1289 
1290 		/* if SGX is enabled */
1291 		if (msr & (1 << 18))
1292 			return;
1293 	}
1294 
1295 	skl_cstates[5].disabled = 1;	/* C8-SKL */
1296 	skl_cstates[6].disabled = 1;	/* C9-SKL */
1297 }
1298 /*
1299  * intel_idle_state_table_update()
1300  *
1301  * Update the default state_table for this CPU-id
1302  */
1303 
1304 static void intel_idle_state_table_update(void)
1305 {
1306 	switch (boot_cpu_data.x86_model) {
1307 
1308 	case INTEL_FAM6_IVYBRIDGE_X:
1309 		ivt_idle_state_table_update();
1310 		break;
1311 	case INTEL_FAM6_ATOM_GOLDMONT:
1312 		bxt_idle_state_table_update();
1313 		break;
1314 	case INTEL_FAM6_SKYLAKE_DESKTOP:
1315 		sklh_idle_state_table_update();
1316 		break;
1317 	}
1318 }
1319 
1320 /*
1321  * intel_idle_cpuidle_driver_init()
1322  * allocate, initialize cpuidle_states
1323  */
1324 static void __init intel_idle_cpuidle_driver_init(void)
1325 {
1326 	int cstate;
1327 	struct cpuidle_driver *drv = &intel_idle_driver;
1328 
1329 	intel_idle_state_table_update();
1330 
1331 	drv->state_count = 1;
1332 
1333 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1334 		int num_substates, mwait_hint, mwait_cstate;
1335 
1336 		if ((cpuidle_state_table[cstate].enter == NULL) &&
1337 		    (cpuidle_state_table[cstate].enter_freeze == NULL))
1338 			break;
1339 
1340 		if (cstate + 1 > max_cstate) {
1341 			printk(PREFIX "max_cstate %d reached\n",
1342 				max_cstate);
1343 			break;
1344 		}
1345 
1346 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1347 		mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
1348 
1349 		/* number of sub-states for this state in CPUID.MWAIT */
1350 		num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
1351 					& MWAIT_SUBSTATE_MASK;
1352 
1353 		/* if NO sub-states for this state in CPUID, skip it */
1354 		if (num_substates == 0)
1355 			continue;
1356 
1357 		/* if state marked as disabled, skip it */
1358 		if (cpuidle_state_table[cstate].disabled != 0) {
1359 			pr_debug(PREFIX "state %s is disabled",
1360 				cpuidle_state_table[cstate].name);
1361 			continue;
1362 		}
1363 
1364 
1365 		if (((mwait_cstate + 1) > 2) &&
1366 			!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1367 			mark_tsc_unstable("TSC halts in idle"
1368 					" states deeper than C2");
1369 
1370 		drv->states[drv->state_count] =	/* structure copy */
1371 			cpuidle_state_table[cstate];
1372 
1373 		drv->state_count += 1;
1374 	}
1375 
1376 	if (icpu->byt_auto_demotion_disable_flag) {
1377 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1378 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1379 	}
1380 }
1381 
1382 
1383 /*
1384  * intel_idle_cpu_init()
1385  * allocate, initialize, register cpuidle_devices
1386  * @cpu: cpu/core to initialize
1387  */
1388 static int intel_idle_cpu_init(unsigned int cpu)
1389 {
1390 	struct cpuidle_device *dev;
1391 
1392 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1393 	dev->cpu = cpu;
1394 
1395 	if (cpuidle_register_device(dev)) {
1396 		pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
1397 		return -EIO;
1398 	}
1399 
1400 	if (icpu->auto_demotion_disable_flags)
1401 		auto_demotion_disable();
1402 
1403 	if (icpu->disable_promotion_to_c1e)
1404 		c1e_promotion_disable();
1405 
1406 	return 0;
1407 }
1408 
1409 static int intel_idle_cpu_online(unsigned int cpu)
1410 {
1411 	struct cpuidle_device *dev;
1412 
1413 	if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
1414 		__setup_broadcast_timer(true);
1415 
1416 	/*
1417 	 * Some systems can hotplug a cpu at runtime after
1418 	 * the kernel has booted, we have to initialize the
1419 	 * driver in this case
1420 	 */
1421 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1422 	if (!dev->registered)
1423 		return intel_idle_cpu_init(cpu);
1424 
1425 	return 0;
1426 }
1427 
1428 static int __init intel_idle_init(void)
1429 {
1430 	int retval;
1431 
1432 	/* Do not load intel_idle at all for now if idle= is passed */
1433 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1434 		return -ENODEV;
1435 
1436 	retval = intel_idle_probe();
1437 	if (retval)
1438 		return retval;
1439 
1440 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1441 	if (intel_idle_cpuidle_devices == NULL)
1442 		return -ENOMEM;
1443 
1444 	intel_idle_cpuidle_driver_init();
1445 	retval = cpuidle_register_driver(&intel_idle_driver);
1446 	if (retval) {
1447 		struct cpuidle_driver *drv = cpuidle_get_driver();
1448 		printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
1449 			drv ? drv->name : "none");
1450 		goto init_driver_fail;
1451 	}
1452 
1453 	if (boot_cpu_has(X86_FEATURE_ARAT))	/* Always Reliable APIC Timer */
1454 		lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
1455 
1456 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1457 				   intel_idle_cpu_online, NULL);
1458 	if (retval < 0)
1459 		goto hp_setup_fail;
1460 
1461 	pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
1462 		lapic_timer_reliable_states);
1463 
1464 	return 0;
1465 
1466 hp_setup_fail:
1467 	intel_idle_cpuidle_devices_uninit();
1468 	cpuidle_unregister_driver(&intel_idle_driver);
1469 init_driver_fail:
1470 	free_percpu(intel_idle_cpuidle_devices);
1471 	return retval;
1472 
1473 }
1474 device_initcall(intel_idle_init);
1475 
1476 /*
1477  * We are not really modular, but we used to support that.  Meaning we also
1478  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1479  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1480  * is the easiest way (currently) to continue doing that.
1481  */
1482 module_param(max_cstate, int, 0444);
1483