xref: /openbmc/linux/drivers/idle/intel_idle.c (revision 0c874100)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
55 
56 #include <linux/kernel.h>
57 #include <linux/cpuidle.h>
58 #include <linux/tick.h>
59 #include <trace/events/power.h>
60 #include <linux/sched.h>
61 #include <linux/notifier.h>
62 #include <linux/cpu.h>
63 #include <linux/moduleparam.h>
64 #include <asm/cpu_device_id.h>
65 #include <asm/intel-family.h>
66 #include <asm/mwait.h>
67 #include <asm/msr.h>
68 
69 #define INTEL_IDLE_VERSION "0.4.1"
70 
71 static struct cpuidle_driver intel_idle_driver = {
72 	.name = "intel_idle",
73 	.owner = THIS_MODULE,
74 };
75 /* intel_idle.max_cstate=0 disables driver */
76 static int max_cstate = CPUIDLE_STATE_MAX - 1;
77 
78 static unsigned int mwait_substates;
79 
80 #define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
81 /* Reliable LAPIC Timer States, bit 1 for C1 etc.  */
82 static unsigned int lapic_timer_reliable_states = (1 << 1);	 /* Default to only C1 */
83 
84 struct idle_cpu {
85 	struct cpuidle_state *state_table;
86 
87 	/*
88 	 * Hardware C-state auto-demotion may not always be optimal.
89 	 * Indicate which enable bits to clear here.
90 	 */
91 	unsigned long auto_demotion_disable_flags;
92 	bool byt_auto_demotion_disable_flag;
93 	bool disable_promotion_to_c1e;
94 };
95 
96 static const struct idle_cpu *icpu;
97 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
98 static int intel_idle(struct cpuidle_device *dev,
99 			struct cpuidle_driver *drv, int index);
100 static void intel_idle_s2idle(struct cpuidle_device *dev,
101 			      struct cpuidle_driver *drv, int index);
102 static struct cpuidle_state *cpuidle_state_table;
103 
104 /*
105  * Set this flag for states where the HW flushes the TLB for us
106  * and so we don't need cross-calls to keep it consistent.
107  * If this flag is set, SW flushes the TLB, so even if the
108  * HW doesn't do the flushing, this flag is safe to use.
109  */
110 #define CPUIDLE_FLAG_TLB_FLUSHED	0x10000
111 
112 /*
113  * MWAIT takes an 8-bit "hint" in EAX "suggesting"
114  * the C-state (top nibble) and sub-state (bottom nibble)
115  * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
116  *
117  * We store the hint at the top of our "flags" for each state.
118  */
119 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
120 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
121 
122 /*
123  * States are indexed by the cstate number,
124  * which is also the index into the MWAIT hint array.
125  * Thus C0 is a dummy.
126  */
127 static struct cpuidle_state nehalem_cstates[] = {
128 	{
129 		.name = "C1",
130 		.desc = "MWAIT 0x00",
131 		.flags = MWAIT2flg(0x00),
132 		.exit_latency = 3,
133 		.target_residency = 6,
134 		.enter = &intel_idle,
135 		.enter_s2idle = intel_idle_s2idle, },
136 	{
137 		.name = "C1E",
138 		.desc = "MWAIT 0x01",
139 		.flags = MWAIT2flg(0x01),
140 		.exit_latency = 10,
141 		.target_residency = 20,
142 		.enter = &intel_idle,
143 		.enter_s2idle = intel_idle_s2idle, },
144 	{
145 		.name = "C3",
146 		.desc = "MWAIT 0x10",
147 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
148 		.exit_latency = 20,
149 		.target_residency = 80,
150 		.enter = &intel_idle,
151 		.enter_s2idle = intel_idle_s2idle, },
152 	{
153 		.name = "C6",
154 		.desc = "MWAIT 0x20",
155 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
156 		.exit_latency = 200,
157 		.target_residency = 800,
158 		.enter = &intel_idle,
159 		.enter_s2idle = intel_idle_s2idle, },
160 	{
161 		.enter = NULL }
162 };
163 
164 static struct cpuidle_state snb_cstates[] = {
165 	{
166 		.name = "C1",
167 		.desc = "MWAIT 0x00",
168 		.flags = MWAIT2flg(0x00),
169 		.exit_latency = 2,
170 		.target_residency = 2,
171 		.enter = &intel_idle,
172 		.enter_s2idle = intel_idle_s2idle, },
173 	{
174 		.name = "C1E",
175 		.desc = "MWAIT 0x01",
176 		.flags = MWAIT2flg(0x01),
177 		.exit_latency = 10,
178 		.target_residency = 20,
179 		.enter = &intel_idle,
180 		.enter_s2idle = intel_idle_s2idle, },
181 	{
182 		.name = "C3",
183 		.desc = "MWAIT 0x10",
184 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
185 		.exit_latency = 80,
186 		.target_residency = 211,
187 		.enter = &intel_idle,
188 		.enter_s2idle = intel_idle_s2idle, },
189 	{
190 		.name = "C6",
191 		.desc = "MWAIT 0x20",
192 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
193 		.exit_latency = 104,
194 		.target_residency = 345,
195 		.enter = &intel_idle,
196 		.enter_s2idle = intel_idle_s2idle, },
197 	{
198 		.name = "C7",
199 		.desc = "MWAIT 0x30",
200 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
201 		.exit_latency = 109,
202 		.target_residency = 345,
203 		.enter = &intel_idle,
204 		.enter_s2idle = intel_idle_s2idle, },
205 	{
206 		.enter = NULL }
207 };
208 
209 static struct cpuidle_state byt_cstates[] = {
210 	{
211 		.name = "C1",
212 		.desc = "MWAIT 0x00",
213 		.flags = MWAIT2flg(0x00),
214 		.exit_latency = 1,
215 		.target_residency = 1,
216 		.enter = &intel_idle,
217 		.enter_s2idle = intel_idle_s2idle, },
218 	{
219 		.name = "C6N",
220 		.desc = "MWAIT 0x58",
221 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
222 		.exit_latency = 300,
223 		.target_residency = 275,
224 		.enter = &intel_idle,
225 		.enter_s2idle = intel_idle_s2idle, },
226 	{
227 		.name = "C6S",
228 		.desc = "MWAIT 0x52",
229 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
230 		.exit_latency = 500,
231 		.target_residency = 560,
232 		.enter = &intel_idle,
233 		.enter_s2idle = intel_idle_s2idle, },
234 	{
235 		.name = "C7",
236 		.desc = "MWAIT 0x60",
237 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
238 		.exit_latency = 1200,
239 		.target_residency = 4000,
240 		.enter = &intel_idle,
241 		.enter_s2idle = intel_idle_s2idle, },
242 	{
243 		.name = "C7S",
244 		.desc = "MWAIT 0x64",
245 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
246 		.exit_latency = 10000,
247 		.target_residency = 20000,
248 		.enter = &intel_idle,
249 		.enter_s2idle = intel_idle_s2idle, },
250 	{
251 		.enter = NULL }
252 };
253 
254 static struct cpuidle_state cht_cstates[] = {
255 	{
256 		.name = "C1",
257 		.desc = "MWAIT 0x00",
258 		.flags = MWAIT2flg(0x00),
259 		.exit_latency = 1,
260 		.target_residency = 1,
261 		.enter = &intel_idle,
262 		.enter_s2idle = intel_idle_s2idle, },
263 	{
264 		.name = "C6N",
265 		.desc = "MWAIT 0x58",
266 		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
267 		.exit_latency = 80,
268 		.target_residency = 275,
269 		.enter = &intel_idle,
270 		.enter_s2idle = intel_idle_s2idle, },
271 	{
272 		.name = "C6S",
273 		.desc = "MWAIT 0x52",
274 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
275 		.exit_latency = 200,
276 		.target_residency = 560,
277 		.enter = &intel_idle,
278 		.enter_s2idle = intel_idle_s2idle, },
279 	{
280 		.name = "C7",
281 		.desc = "MWAIT 0x60",
282 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
283 		.exit_latency = 1200,
284 		.target_residency = 4000,
285 		.enter = &intel_idle,
286 		.enter_s2idle = intel_idle_s2idle, },
287 	{
288 		.name = "C7S",
289 		.desc = "MWAIT 0x64",
290 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
291 		.exit_latency = 10000,
292 		.target_residency = 20000,
293 		.enter = &intel_idle,
294 		.enter_s2idle = intel_idle_s2idle, },
295 	{
296 		.enter = NULL }
297 };
298 
299 static struct cpuidle_state ivb_cstates[] = {
300 	{
301 		.name = "C1",
302 		.desc = "MWAIT 0x00",
303 		.flags = MWAIT2flg(0x00),
304 		.exit_latency = 1,
305 		.target_residency = 1,
306 		.enter = &intel_idle,
307 		.enter_s2idle = intel_idle_s2idle, },
308 	{
309 		.name = "C1E",
310 		.desc = "MWAIT 0x01",
311 		.flags = MWAIT2flg(0x01),
312 		.exit_latency = 10,
313 		.target_residency = 20,
314 		.enter = &intel_idle,
315 		.enter_s2idle = intel_idle_s2idle, },
316 	{
317 		.name = "C3",
318 		.desc = "MWAIT 0x10",
319 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
320 		.exit_latency = 59,
321 		.target_residency = 156,
322 		.enter = &intel_idle,
323 		.enter_s2idle = intel_idle_s2idle, },
324 	{
325 		.name = "C6",
326 		.desc = "MWAIT 0x20",
327 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
328 		.exit_latency = 80,
329 		.target_residency = 300,
330 		.enter = &intel_idle,
331 		.enter_s2idle = intel_idle_s2idle, },
332 	{
333 		.name = "C7",
334 		.desc = "MWAIT 0x30",
335 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
336 		.exit_latency = 87,
337 		.target_residency = 300,
338 		.enter = &intel_idle,
339 		.enter_s2idle = intel_idle_s2idle, },
340 	{
341 		.enter = NULL }
342 };
343 
344 static struct cpuidle_state ivt_cstates[] = {
345 	{
346 		.name = "C1",
347 		.desc = "MWAIT 0x00",
348 		.flags = MWAIT2flg(0x00),
349 		.exit_latency = 1,
350 		.target_residency = 1,
351 		.enter = &intel_idle,
352 		.enter_s2idle = intel_idle_s2idle, },
353 	{
354 		.name = "C1E",
355 		.desc = "MWAIT 0x01",
356 		.flags = MWAIT2flg(0x01),
357 		.exit_latency = 10,
358 		.target_residency = 80,
359 		.enter = &intel_idle,
360 		.enter_s2idle = intel_idle_s2idle, },
361 	{
362 		.name = "C3",
363 		.desc = "MWAIT 0x10",
364 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
365 		.exit_latency = 59,
366 		.target_residency = 156,
367 		.enter = &intel_idle,
368 		.enter_s2idle = intel_idle_s2idle, },
369 	{
370 		.name = "C6",
371 		.desc = "MWAIT 0x20",
372 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
373 		.exit_latency = 82,
374 		.target_residency = 300,
375 		.enter = &intel_idle,
376 		.enter_s2idle = intel_idle_s2idle, },
377 	{
378 		.enter = NULL }
379 };
380 
381 static struct cpuidle_state ivt_cstates_4s[] = {
382 	{
383 		.name = "C1",
384 		.desc = "MWAIT 0x00",
385 		.flags = MWAIT2flg(0x00),
386 		.exit_latency = 1,
387 		.target_residency = 1,
388 		.enter = &intel_idle,
389 		.enter_s2idle = intel_idle_s2idle, },
390 	{
391 		.name = "C1E",
392 		.desc = "MWAIT 0x01",
393 		.flags = MWAIT2flg(0x01),
394 		.exit_latency = 10,
395 		.target_residency = 250,
396 		.enter = &intel_idle,
397 		.enter_s2idle = intel_idle_s2idle, },
398 	{
399 		.name = "C3",
400 		.desc = "MWAIT 0x10",
401 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
402 		.exit_latency = 59,
403 		.target_residency = 300,
404 		.enter = &intel_idle,
405 		.enter_s2idle = intel_idle_s2idle, },
406 	{
407 		.name = "C6",
408 		.desc = "MWAIT 0x20",
409 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
410 		.exit_latency = 84,
411 		.target_residency = 400,
412 		.enter = &intel_idle,
413 		.enter_s2idle = intel_idle_s2idle, },
414 	{
415 		.enter = NULL }
416 };
417 
418 static struct cpuidle_state ivt_cstates_8s[] = {
419 	{
420 		.name = "C1",
421 		.desc = "MWAIT 0x00",
422 		.flags = MWAIT2flg(0x00),
423 		.exit_latency = 1,
424 		.target_residency = 1,
425 		.enter = &intel_idle,
426 		.enter_s2idle = intel_idle_s2idle, },
427 	{
428 		.name = "C1E",
429 		.desc = "MWAIT 0x01",
430 		.flags = MWAIT2flg(0x01),
431 		.exit_latency = 10,
432 		.target_residency = 500,
433 		.enter = &intel_idle,
434 		.enter_s2idle = intel_idle_s2idle, },
435 	{
436 		.name = "C3",
437 		.desc = "MWAIT 0x10",
438 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
439 		.exit_latency = 59,
440 		.target_residency = 600,
441 		.enter = &intel_idle,
442 		.enter_s2idle = intel_idle_s2idle, },
443 	{
444 		.name = "C6",
445 		.desc = "MWAIT 0x20",
446 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
447 		.exit_latency = 88,
448 		.target_residency = 700,
449 		.enter = &intel_idle,
450 		.enter_s2idle = intel_idle_s2idle, },
451 	{
452 		.enter = NULL }
453 };
454 
455 static struct cpuidle_state hsw_cstates[] = {
456 	{
457 		.name = "C1",
458 		.desc = "MWAIT 0x00",
459 		.flags = MWAIT2flg(0x00),
460 		.exit_latency = 2,
461 		.target_residency = 2,
462 		.enter = &intel_idle,
463 		.enter_s2idle = intel_idle_s2idle, },
464 	{
465 		.name = "C1E",
466 		.desc = "MWAIT 0x01",
467 		.flags = MWAIT2flg(0x01),
468 		.exit_latency = 10,
469 		.target_residency = 20,
470 		.enter = &intel_idle,
471 		.enter_s2idle = intel_idle_s2idle, },
472 	{
473 		.name = "C3",
474 		.desc = "MWAIT 0x10",
475 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
476 		.exit_latency = 33,
477 		.target_residency = 100,
478 		.enter = &intel_idle,
479 		.enter_s2idle = intel_idle_s2idle, },
480 	{
481 		.name = "C6",
482 		.desc = "MWAIT 0x20",
483 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
484 		.exit_latency = 133,
485 		.target_residency = 400,
486 		.enter = &intel_idle,
487 		.enter_s2idle = intel_idle_s2idle, },
488 	{
489 		.name = "C7s",
490 		.desc = "MWAIT 0x32",
491 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
492 		.exit_latency = 166,
493 		.target_residency = 500,
494 		.enter = &intel_idle,
495 		.enter_s2idle = intel_idle_s2idle, },
496 	{
497 		.name = "C8",
498 		.desc = "MWAIT 0x40",
499 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
500 		.exit_latency = 300,
501 		.target_residency = 900,
502 		.enter = &intel_idle,
503 		.enter_s2idle = intel_idle_s2idle, },
504 	{
505 		.name = "C9",
506 		.desc = "MWAIT 0x50",
507 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
508 		.exit_latency = 600,
509 		.target_residency = 1800,
510 		.enter = &intel_idle,
511 		.enter_s2idle = intel_idle_s2idle, },
512 	{
513 		.name = "C10",
514 		.desc = "MWAIT 0x60",
515 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
516 		.exit_latency = 2600,
517 		.target_residency = 7700,
518 		.enter = &intel_idle,
519 		.enter_s2idle = intel_idle_s2idle, },
520 	{
521 		.enter = NULL }
522 };
523 static struct cpuidle_state bdw_cstates[] = {
524 	{
525 		.name = "C1",
526 		.desc = "MWAIT 0x00",
527 		.flags = MWAIT2flg(0x00),
528 		.exit_latency = 2,
529 		.target_residency = 2,
530 		.enter = &intel_idle,
531 		.enter_s2idle = intel_idle_s2idle, },
532 	{
533 		.name = "C1E",
534 		.desc = "MWAIT 0x01",
535 		.flags = MWAIT2flg(0x01),
536 		.exit_latency = 10,
537 		.target_residency = 20,
538 		.enter = &intel_idle,
539 		.enter_s2idle = intel_idle_s2idle, },
540 	{
541 		.name = "C3",
542 		.desc = "MWAIT 0x10",
543 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
544 		.exit_latency = 40,
545 		.target_residency = 100,
546 		.enter = &intel_idle,
547 		.enter_s2idle = intel_idle_s2idle, },
548 	{
549 		.name = "C6",
550 		.desc = "MWAIT 0x20",
551 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
552 		.exit_latency = 133,
553 		.target_residency = 400,
554 		.enter = &intel_idle,
555 		.enter_s2idle = intel_idle_s2idle, },
556 	{
557 		.name = "C7s",
558 		.desc = "MWAIT 0x32",
559 		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
560 		.exit_latency = 166,
561 		.target_residency = 500,
562 		.enter = &intel_idle,
563 		.enter_s2idle = intel_idle_s2idle, },
564 	{
565 		.name = "C8",
566 		.desc = "MWAIT 0x40",
567 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
568 		.exit_latency = 300,
569 		.target_residency = 900,
570 		.enter = &intel_idle,
571 		.enter_s2idle = intel_idle_s2idle, },
572 	{
573 		.name = "C9",
574 		.desc = "MWAIT 0x50",
575 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
576 		.exit_latency = 600,
577 		.target_residency = 1800,
578 		.enter = &intel_idle,
579 		.enter_s2idle = intel_idle_s2idle, },
580 	{
581 		.name = "C10",
582 		.desc = "MWAIT 0x60",
583 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
584 		.exit_latency = 2600,
585 		.target_residency = 7700,
586 		.enter = &intel_idle,
587 		.enter_s2idle = intel_idle_s2idle, },
588 	{
589 		.enter = NULL }
590 };
591 
592 static struct cpuidle_state skl_cstates[] = {
593 	{
594 		.name = "C1",
595 		.desc = "MWAIT 0x00",
596 		.flags = MWAIT2flg(0x00),
597 		.exit_latency = 2,
598 		.target_residency = 2,
599 		.enter = &intel_idle,
600 		.enter_s2idle = intel_idle_s2idle, },
601 	{
602 		.name = "C1E",
603 		.desc = "MWAIT 0x01",
604 		.flags = MWAIT2flg(0x01),
605 		.exit_latency = 10,
606 		.target_residency = 20,
607 		.enter = &intel_idle,
608 		.enter_s2idle = intel_idle_s2idle, },
609 	{
610 		.name = "C3",
611 		.desc = "MWAIT 0x10",
612 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
613 		.exit_latency = 70,
614 		.target_residency = 100,
615 		.enter = &intel_idle,
616 		.enter_s2idle = intel_idle_s2idle, },
617 	{
618 		.name = "C6",
619 		.desc = "MWAIT 0x20",
620 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
621 		.exit_latency = 85,
622 		.target_residency = 200,
623 		.enter = &intel_idle,
624 		.enter_s2idle = intel_idle_s2idle, },
625 	{
626 		.name = "C7s",
627 		.desc = "MWAIT 0x33",
628 		.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
629 		.exit_latency = 124,
630 		.target_residency = 800,
631 		.enter = &intel_idle,
632 		.enter_s2idle = intel_idle_s2idle, },
633 	{
634 		.name = "C8",
635 		.desc = "MWAIT 0x40",
636 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
637 		.exit_latency = 200,
638 		.target_residency = 800,
639 		.enter = &intel_idle,
640 		.enter_s2idle = intel_idle_s2idle, },
641 	{
642 		.name = "C9",
643 		.desc = "MWAIT 0x50",
644 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
645 		.exit_latency = 480,
646 		.target_residency = 5000,
647 		.enter = &intel_idle,
648 		.enter_s2idle = intel_idle_s2idle, },
649 	{
650 		.name = "C10",
651 		.desc = "MWAIT 0x60",
652 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
653 		.exit_latency = 890,
654 		.target_residency = 5000,
655 		.enter = &intel_idle,
656 		.enter_s2idle = intel_idle_s2idle, },
657 	{
658 		.enter = NULL }
659 };
660 
661 static struct cpuidle_state skx_cstates[] = {
662 	{
663 		.name = "C1",
664 		.desc = "MWAIT 0x00",
665 		.flags = MWAIT2flg(0x00),
666 		.exit_latency = 2,
667 		.target_residency = 2,
668 		.enter = &intel_idle,
669 		.enter_s2idle = intel_idle_s2idle, },
670 	{
671 		.name = "C1E",
672 		.desc = "MWAIT 0x01",
673 		.flags = MWAIT2flg(0x01),
674 		.exit_latency = 10,
675 		.target_residency = 20,
676 		.enter = &intel_idle,
677 		.enter_s2idle = intel_idle_s2idle, },
678 	{
679 		.name = "C6",
680 		.desc = "MWAIT 0x20",
681 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
682 		.exit_latency = 133,
683 		.target_residency = 600,
684 		.enter = &intel_idle,
685 		.enter_s2idle = intel_idle_s2idle, },
686 	{
687 		.enter = NULL }
688 };
689 
690 static struct cpuidle_state atom_cstates[] = {
691 	{
692 		.name = "C1E",
693 		.desc = "MWAIT 0x00",
694 		.flags = MWAIT2flg(0x00),
695 		.exit_latency = 10,
696 		.target_residency = 20,
697 		.enter = &intel_idle,
698 		.enter_s2idle = intel_idle_s2idle, },
699 	{
700 		.name = "C2",
701 		.desc = "MWAIT 0x10",
702 		.flags = MWAIT2flg(0x10),
703 		.exit_latency = 20,
704 		.target_residency = 80,
705 		.enter = &intel_idle,
706 		.enter_s2idle = intel_idle_s2idle, },
707 	{
708 		.name = "C4",
709 		.desc = "MWAIT 0x30",
710 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
711 		.exit_latency = 100,
712 		.target_residency = 400,
713 		.enter = &intel_idle,
714 		.enter_s2idle = intel_idle_s2idle, },
715 	{
716 		.name = "C6",
717 		.desc = "MWAIT 0x52",
718 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
719 		.exit_latency = 140,
720 		.target_residency = 560,
721 		.enter = &intel_idle,
722 		.enter_s2idle = intel_idle_s2idle, },
723 	{
724 		.enter = NULL }
725 };
726 static struct cpuidle_state tangier_cstates[] = {
727 	{
728 		.name = "C1",
729 		.desc = "MWAIT 0x00",
730 		.flags = MWAIT2flg(0x00),
731 		.exit_latency = 1,
732 		.target_residency = 4,
733 		.enter = &intel_idle,
734 		.enter_s2idle = intel_idle_s2idle, },
735 	{
736 		.name = "C4",
737 		.desc = "MWAIT 0x30",
738 		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
739 		.exit_latency = 100,
740 		.target_residency = 400,
741 		.enter = &intel_idle,
742 		.enter_s2idle = intel_idle_s2idle, },
743 	{
744 		.name = "C6",
745 		.desc = "MWAIT 0x52",
746 		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
747 		.exit_latency = 140,
748 		.target_residency = 560,
749 		.enter = &intel_idle,
750 		.enter_s2idle = intel_idle_s2idle, },
751 	{
752 		.name = "C7",
753 		.desc = "MWAIT 0x60",
754 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
755 		.exit_latency = 1200,
756 		.target_residency = 4000,
757 		.enter = &intel_idle,
758 		.enter_s2idle = intel_idle_s2idle, },
759 	{
760 		.name = "C9",
761 		.desc = "MWAIT 0x64",
762 		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
763 		.exit_latency = 10000,
764 		.target_residency = 20000,
765 		.enter = &intel_idle,
766 		.enter_s2idle = intel_idle_s2idle, },
767 	{
768 		.enter = NULL }
769 };
770 static struct cpuidle_state avn_cstates[] = {
771 	{
772 		.name = "C1",
773 		.desc = "MWAIT 0x00",
774 		.flags = MWAIT2flg(0x00),
775 		.exit_latency = 2,
776 		.target_residency = 2,
777 		.enter = &intel_idle,
778 		.enter_s2idle = intel_idle_s2idle, },
779 	{
780 		.name = "C6",
781 		.desc = "MWAIT 0x51",
782 		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
783 		.exit_latency = 15,
784 		.target_residency = 45,
785 		.enter = &intel_idle,
786 		.enter_s2idle = intel_idle_s2idle, },
787 	{
788 		.enter = NULL }
789 };
790 static struct cpuidle_state knl_cstates[] = {
791 	{
792 		.name = "C1",
793 		.desc = "MWAIT 0x00",
794 		.flags = MWAIT2flg(0x00),
795 		.exit_latency = 1,
796 		.target_residency = 2,
797 		.enter = &intel_idle,
798 		.enter_s2idle = intel_idle_s2idle },
799 	{
800 		.name = "C6",
801 		.desc = "MWAIT 0x10",
802 		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
803 		.exit_latency = 120,
804 		.target_residency = 500,
805 		.enter = &intel_idle,
806 		.enter_s2idle = intel_idle_s2idle },
807 	{
808 		.enter = NULL }
809 };
810 
811 static struct cpuidle_state bxt_cstates[] = {
812 	{
813 		.name = "C1",
814 		.desc = "MWAIT 0x00",
815 		.flags = MWAIT2flg(0x00),
816 		.exit_latency = 2,
817 		.target_residency = 2,
818 		.enter = &intel_idle,
819 		.enter_s2idle = intel_idle_s2idle, },
820 	{
821 		.name = "C1E",
822 		.desc = "MWAIT 0x01",
823 		.flags = MWAIT2flg(0x01),
824 		.exit_latency = 10,
825 		.target_residency = 20,
826 		.enter = &intel_idle,
827 		.enter_s2idle = intel_idle_s2idle, },
828 	{
829 		.name = "C6",
830 		.desc = "MWAIT 0x20",
831 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
832 		.exit_latency = 133,
833 		.target_residency = 133,
834 		.enter = &intel_idle,
835 		.enter_s2idle = intel_idle_s2idle, },
836 	{
837 		.name = "C7s",
838 		.desc = "MWAIT 0x31",
839 		.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
840 		.exit_latency = 155,
841 		.target_residency = 155,
842 		.enter = &intel_idle,
843 		.enter_s2idle = intel_idle_s2idle, },
844 	{
845 		.name = "C8",
846 		.desc = "MWAIT 0x40",
847 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
848 		.exit_latency = 1000,
849 		.target_residency = 1000,
850 		.enter = &intel_idle,
851 		.enter_s2idle = intel_idle_s2idle, },
852 	{
853 		.name = "C9",
854 		.desc = "MWAIT 0x50",
855 		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
856 		.exit_latency = 2000,
857 		.target_residency = 2000,
858 		.enter = &intel_idle,
859 		.enter_s2idle = intel_idle_s2idle, },
860 	{
861 		.name = "C10",
862 		.desc = "MWAIT 0x60",
863 		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
864 		.exit_latency = 10000,
865 		.target_residency = 10000,
866 		.enter = &intel_idle,
867 		.enter_s2idle = intel_idle_s2idle, },
868 	{
869 		.enter = NULL }
870 };
871 
872 static struct cpuidle_state dnv_cstates[] = {
873 	{
874 		.name = "C1",
875 		.desc = "MWAIT 0x00",
876 		.flags = MWAIT2flg(0x00),
877 		.exit_latency = 2,
878 		.target_residency = 2,
879 		.enter = &intel_idle,
880 		.enter_s2idle = intel_idle_s2idle, },
881 	{
882 		.name = "C1E",
883 		.desc = "MWAIT 0x01",
884 		.flags = MWAIT2flg(0x01),
885 		.exit_latency = 10,
886 		.target_residency = 20,
887 		.enter = &intel_idle,
888 		.enter_s2idle = intel_idle_s2idle, },
889 	{
890 		.name = "C6",
891 		.desc = "MWAIT 0x20",
892 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
893 		.exit_latency = 50,
894 		.target_residency = 500,
895 		.enter = &intel_idle,
896 		.enter_s2idle = intel_idle_s2idle, },
897 	{
898 		.enter = NULL }
899 };
900 
901 /**
902  * intel_idle
903  * @dev: cpuidle_device
904  * @drv: cpuidle driver
905  * @index: index of cpuidle state
906  *
907  * Must be called under local_irq_disable().
908  */
909 static __cpuidle int intel_idle(struct cpuidle_device *dev,
910 				struct cpuidle_driver *drv, int index)
911 {
912 	unsigned long ecx = 1; /* break on interrupt flag */
913 	struct cpuidle_state *state = &drv->states[index];
914 	unsigned long eax = flg2MWAIT(state->flags);
915 	unsigned int cstate;
916 	bool uninitialized_var(tick);
917 	int cpu = smp_processor_id();
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 (!static_cpu_has(X86_FEATURE_ARAT)) {
927 		cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) &
928 				MWAIT_CSTATE_MASK) + 1;
929 		tick = false;
930 		if (!(lapic_timer_reliable_states & (1 << (cstate)))) {
931 			tick = true;
932 			tick_broadcast_enter();
933 		}
934 	}
935 
936 	mwait_idle_with_hints(eax, ecx);
937 
938 	if (!static_cpu_has(X86_FEATURE_ARAT) && tick)
939 		tick_broadcast_exit();
940 
941 	return index;
942 }
943 
944 /**
945  * intel_idle_s2idle - simplified "enter" callback routine for suspend-to-idle
946  * @dev: cpuidle_device
947  * @drv: cpuidle driver
948  * @index: state index
949  */
950 static void intel_idle_s2idle(struct cpuidle_device *dev,
951 			     struct cpuidle_driver *drv, int index)
952 {
953 	unsigned long ecx = 1; /* break on interrupt flag */
954 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
955 
956 	mwait_idle_with_hints(eax, ecx);
957 }
958 
959 static void __setup_broadcast_timer(bool on)
960 {
961 	if (on)
962 		tick_broadcast_enable();
963 	else
964 		tick_broadcast_disable();
965 }
966 
967 static void auto_demotion_disable(void)
968 {
969 	unsigned long long msr_bits;
970 
971 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
972 	msr_bits &= ~(icpu->auto_demotion_disable_flags);
973 	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
974 }
975 static void c1e_promotion_disable(void)
976 {
977 	unsigned long long msr_bits;
978 
979 	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
980 	msr_bits &= ~0x2;
981 	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
982 }
983 
984 static const struct idle_cpu idle_cpu_nehalem = {
985 	.state_table = nehalem_cstates,
986 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
987 	.disable_promotion_to_c1e = true,
988 };
989 
990 static const struct idle_cpu idle_cpu_atom = {
991 	.state_table = atom_cstates,
992 };
993 
994 static const struct idle_cpu idle_cpu_tangier = {
995 	.state_table = tangier_cstates,
996 };
997 
998 static const struct idle_cpu idle_cpu_lincroft = {
999 	.state_table = atom_cstates,
1000 	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
1001 };
1002 
1003 static const struct idle_cpu idle_cpu_snb = {
1004 	.state_table = snb_cstates,
1005 	.disable_promotion_to_c1e = true,
1006 };
1007 
1008 static const struct idle_cpu idle_cpu_byt = {
1009 	.state_table = byt_cstates,
1010 	.disable_promotion_to_c1e = true,
1011 	.byt_auto_demotion_disable_flag = true,
1012 };
1013 
1014 static const struct idle_cpu idle_cpu_cht = {
1015 	.state_table = cht_cstates,
1016 	.disable_promotion_to_c1e = true,
1017 	.byt_auto_demotion_disable_flag = true,
1018 };
1019 
1020 static const struct idle_cpu idle_cpu_ivb = {
1021 	.state_table = ivb_cstates,
1022 	.disable_promotion_to_c1e = true,
1023 };
1024 
1025 static const struct idle_cpu idle_cpu_ivt = {
1026 	.state_table = ivt_cstates,
1027 	.disable_promotion_to_c1e = true,
1028 };
1029 
1030 static const struct idle_cpu idle_cpu_hsw = {
1031 	.state_table = hsw_cstates,
1032 	.disable_promotion_to_c1e = true,
1033 };
1034 
1035 static const struct idle_cpu idle_cpu_bdw = {
1036 	.state_table = bdw_cstates,
1037 	.disable_promotion_to_c1e = true,
1038 };
1039 
1040 static const struct idle_cpu idle_cpu_skl = {
1041 	.state_table = skl_cstates,
1042 	.disable_promotion_to_c1e = true,
1043 };
1044 
1045 static const struct idle_cpu idle_cpu_skx = {
1046 	.state_table = skx_cstates,
1047 	.disable_promotion_to_c1e = true,
1048 };
1049 
1050 static const struct idle_cpu idle_cpu_avn = {
1051 	.state_table = avn_cstates,
1052 	.disable_promotion_to_c1e = true,
1053 };
1054 
1055 static const struct idle_cpu idle_cpu_knl = {
1056 	.state_table = knl_cstates,
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 };
1068 
1069 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1070 	INTEL_CPU_FAM6(NEHALEM_EP,		idle_cpu_nehalem),
1071 	INTEL_CPU_FAM6(NEHALEM,			idle_cpu_nehalem),
1072 	INTEL_CPU_FAM6(NEHALEM_G,		idle_cpu_nehalem),
1073 	INTEL_CPU_FAM6(WESTMERE,		idle_cpu_nehalem),
1074 	INTEL_CPU_FAM6(WESTMERE_EP,		idle_cpu_nehalem),
1075 	INTEL_CPU_FAM6(NEHALEM_EX,		idle_cpu_nehalem),
1076 	INTEL_CPU_FAM6(ATOM_BONNELL,		idle_cpu_atom),
1077 	INTEL_CPU_FAM6(ATOM_BONNELL_MID,	idle_cpu_lincroft),
1078 	INTEL_CPU_FAM6(WESTMERE_EX,		idle_cpu_nehalem),
1079 	INTEL_CPU_FAM6(SANDYBRIDGE,		idle_cpu_snb),
1080 	INTEL_CPU_FAM6(SANDYBRIDGE_X,		idle_cpu_snb),
1081 	INTEL_CPU_FAM6(ATOM_SALTWELL,		idle_cpu_atom),
1082 	INTEL_CPU_FAM6(ATOM_SILVERMONT,		idle_cpu_byt),
1083 	INTEL_CPU_FAM6(ATOM_SILVERMONT_MID,	idle_cpu_tangier),
1084 	INTEL_CPU_FAM6(ATOM_AIRMONT,		idle_cpu_cht),
1085 	INTEL_CPU_FAM6(IVYBRIDGE,		idle_cpu_ivb),
1086 	INTEL_CPU_FAM6(IVYBRIDGE_X,		idle_cpu_ivt),
1087 	INTEL_CPU_FAM6(HASWELL_CORE,		idle_cpu_hsw),
1088 	INTEL_CPU_FAM6(HASWELL_X,		idle_cpu_hsw),
1089 	INTEL_CPU_FAM6(HASWELL_ULT,		idle_cpu_hsw),
1090 	INTEL_CPU_FAM6(HASWELL_GT3E,		idle_cpu_hsw),
1091 	INTEL_CPU_FAM6(ATOM_SILVERMONT_X,	idle_cpu_avn),
1092 	INTEL_CPU_FAM6(BROADWELL_CORE,		idle_cpu_bdw),
1093 	INTEL_CPU_FAM6(BROADWELL_GT3E,		idle_cpu_bdw),
1094 	INTEL_CPU_FAM6(BROADWELL_X,		idle_cpu_bdw),
1095 	INTEL_CPU_FAM6(BROADWELL_XEON_D,	idle_cpu_bdw),
1096 	INTEL_CPU_FAM6(SKYLAKE_MOBILE,		idle_cpu_skl),
1097 	INTEL_CPU_FAM6(SKYLAKE_DESKTOP,		idle_cpu_skl),
1098 	INTEL_CPU_FAM6(KABYLAKE_MOBILE,		idle_cpu_skl),
1099 	INTEL_CPU_FAM6(KABYLAKE_DESKTOP,	idle_cpu_skl),
1100 	INTEL_CPU_FAM6(SKYLAKE_X,		idle_cpu_skx),
1101 	INTEL_CPU_FAM6(XEON_PHI_KNL,		idle_cpu_knl),
1102 	INTEL_CPU_FAM6(XEON_PHI_KNM,		idle_cpu_knl),
1103 	INTEL_CPU_FAM6(ATOM_GOLDMONT,		idle_cpu_bxt),
1104 	INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS,	idle_cpu_bxt),
1105 	INTEL_CPU_FAM6(ATOM_GOLDMONT_X,		idle_cpu_dnv),
1106 	{}
1107 };
1108 
1109 /*
1110  * intel_idle_probe()
1111  */
1112 static int __init intel_idle_probe(void)
1113 {
1114 	unsigned int eax, ebx, ecx;
1115 	const struct x86_cpu_id *id;
1116 
1117 	if (max_cstate == 0) {
1118 		pr_debug("disabled\n");
1119 		return -EPERM;
1120 	}
1121 
1122 	id = x86_match_cpu(intel_idle_ids);
1123 	if (!id) {
1124 		if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
1125 		    boot_cpu_data.x86 == 6)
1126 			pr_debug("does not run on family %d model %d\n",
1127 				 boot_cpu_data.x86, boot_cpu_data.x86_model);
1128 		return -ENODEV;
1129 	}
1130 
1131 	if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1132 		pr_debug("Please enable MWAIT in BIOS SETUP\n");
1133 		return -ENODEV;
1134 	}
1135 
1136 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1137 		return -ENODEV;
1138 
1139 	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1140 
1141 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1142 	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1143 	    !mwait_substates)
1144 			return -ENODEV;
1145 
1146 	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1147 
1148 	icpu = (const struct idle_cpu *)id->driver_data;
1149 	cpuidle_state_table = icpu->state_table;
1150 
1151 	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1152 		 boot_cpu_data.x86_model);
1153 
1154 	return 0;
1155 }
1156 
1157 /*
1158  * intel_idle_cpuidle_devices_uninit()
1159  * Unregisters the cpuidle devices.
1160  */
1161 static void intel_idle_cpuidle_devices_uninit(void)
1162 {
1163 	int i;
1164 	struct cpuidle_device *dev;
1165 
1166 	for_each_online_cpu(i) {
1167 		dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1168 		cpuidle_unregister_device(dev);
1169 	}
1170 }
1171 
1172 /*
1173  * ivt_idle_state_table_update(void)
1174  *
1175  * Tune IVT multi-socket targets
1176  * Assumption: num_sockets == (max_package_num + 1)
1177  */
1178 static void ivt_idle_state_table_update(void)
1179 {
1180 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1181 	int cpu, package_num, num_sockets = 1;
1182 
1183 	for_each_online_cpu(cpu) {
1184 		package_num = topology_physical_package_id(cpu);
1185 		if (package_num + 1 > num_sockets) {
1186 			num_sockets = package_num + 1;
1187 
1188 			if (num_sockets > 4) {
1189 				cpuidle_state_table = ivt_cstates_8s;
1190 				return;
1191 			}
1192 		}
1193 	}
1194 
1195 	if (num_sockets > 2)
1196 		cpuidle_state_table = ivt_cstates_4s;
1197 
1198 	/* else, 1 and 2 socket systems use default ivt_cstates */
1199 }
1200 
1201 /*
1202  * Translate IRTL (Interrupt Response Time Limit) MSR to usec
1203  */
1204 
1205 static unsigned int irtl_ns_units[] = {
1206 	1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
1207 
1208 static unsigned long long irtl_2_usec(unsigned long long irtl)
1209 {
1210 	unsigned long long ns;
1211 
1212 	if (!irtl)
1213 		return 0;
1214 
1215 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
1216 
1217 	return div64_u64((irtl & 0x3FF) * ns, 1000);
1218 }
1219 /*
1220  * bxt_idle_state_table_update(void)
1221  *
1222  * On BXT, we trust the IRTL to show the definitive maximum latency
1223  * We use the same value for target_residency.
1224  */
1225 static void bxt_idle_state_table_update(void)
1226 {
1227 	unsigned long long msr;
1228 	unsigned int usec;
1229 
1230 	rdmsrl(MSR_PKGC6_IRTL, msr);
1231 	usec = irtl_2_usec(msr);
1232 	if (usec) {
1233 		bxt_cstates[2].exit_latency = usec;
1234 		bxt_cstates[2].target_residency = usec;
1235 	}
1236 
1237 	rdmsrl(MSR_PKGC7_IRTL, msr);
1238 	usec = irtl_2_usec(msr);
1239 	if (usec) {
1240 		bxt_cstates[3].exit_latency = usec;
1241 		bxt_cstates[3].target_residency = usec;
1242 	}
1243 
1244 	rdmsrl(MSR_PKGC8_IRTL, msr);
1245 	usec = irtl_2_usec(msr);
1246 	if (usec) {
1247 		bxt_cstates[4].exit_latency = usec;
1248 		bxt_cstates[4].target_residency = usec;
1249 	}
1250 
1251 	rdmsrl(MSR_PKGC9_IRTL, msr);
1252 	usec = irtl_2_usec(msr);
1253 	if (usec) {
1254 		bxt_cstates[5].exit_latency = usec;
1255 		bxt_cstates[5].target_residency = usec;
1256 	}
1257 
1258 	rdmsrl(MSR_PKGC10_IRTL, msr);
1259 	usec = irtl_2_usec(msr);
1260 	if (usec) {
1261 		bxt_cstates[6].exit_latency = usec;
1262 		bxt_cstates[6].target_residency = usec;
1263 	}
1264 
1265 }
1266 /*
1267  * sklh_idle_state_table_update(void)
1268  *
1269  * On SKL-H (model 0x5e) disable C8 and C9 if:
1270  * C10 is enabled and SGX disabled
1271  */
1272 static void sklh_idle_state_table_update(void)
1273 {
1274 	unsigned long long msr;
1275 	unsigned int eax, ebx, ecx, edx;
1276 
1277 
1278 	/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1279 	if (max_cstate <= 7)
1280 		return;
1281 
1282 	/* if PC10 not present in CPUID.MWAIT.EDX */
1283 	if ((mwait_substates & (0xF << 28)) == 0)
1284 		return;
1285 
1286 	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1287 
1288 	/* PC10 is not enabled in PKG C-state limit */
1289 	if ((msr & 0xF) != 8)
1290 		return;
1291 
1292 	ecx = 0;
1293 	cpuid(7, &eax, &ebx, &ecx, &edx);
1294 
1295 	/* if SGX is present */
1296 	if (ebx & (1 << 2)) {
1297 
1298 		rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
1299 
1300 		/* if SGX is enabled */
1301 		if (msr & (1 << 18))
1302 			return;
1303 	}
1304 
1305 	skl_cstates[5].disabled = 1;	/* C8-SKL */
1306 	skl_cstates[6].disabled = 1;	/* C9-SKL */
1307 }
1308 /*
1309  * intel_idle_state_table_update()
1310  *
1311  * Update the default state_table for this CPU-id
1312  */
1313 
1314 static void intel_idle_state_table_update(void)
1315 {
1316 	switch (boot_cpu_data.x86_model) {
1317 
1318 	case INTEL_FAM6_IVYBRIDGE_X:
1319 		ivt_idle_state_table_update();
1320 		break;
1321 	case INTEL_FAM6_ATOM_GOLDMONT:
1322 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1323 		bxt_idle_state_table_update();
1324 		break;
1325 	case INTEL_FAM6_SKYLAKE_DESKTOP:
1326 		sklh_idle_state_table_update();
1327 		break;
1328 	}
1329 }
1330 
1331 /*
1332  * intel_idle_cpuidle_driver_init()
1333  * allocate, initialize cpuidle_states
1334  */
1335 static void __init intel_idle_cpuidle_driver_init(void)
1336 {
1337 	int cstate;
1338 	struct cpuidle_driver *drv = &intel_idle_driver;
1339 
1340 	intel_idle_state_table_update();
1341 
1342 	cpuidle_poll_state_init(drv);
1343 	drv->state_count = 1;
1344 
1345 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1346 		int num_substates, mwait_hint, mwait_cstate;
1347 
1348 		if ((cpuidle_state_table[cstate].enter == NULL) &&
1349 		    (cpuidle_state_table[cstate].enter_s2idle == NULL))
1350 			break;
1351 
1352 		if (cstate + 1 > max_cstate) {
1353 			pr_info("max_cstate %d reached\n", max_cstate);
1354 			break;
1355 		}
1356 
1357 		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1358 		mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
1359 
1360 		/* number of sub-states for this state in CPUID.MWAIT */
1361 		num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
1362 					& MWAIT_SUBSTATE_MASK;
1363 
1364 		/* if NO sub-states for this state in CPUID, skip it */
1365 		if (num_substates == 0)
1366 			continue;
1367 
1368 		/* if state marked as disabled, skip it */
1369 		if (cpuidle_state_table[cstate].disabled != 0) {
1370 			pr_debug("state %s is disabled\n",
1371 				 cpuidle_state_table[cstate].name);
1372 			continue;
1373 		}
1374 
1375 
1376 		if (((mwait_cstate + 1) > 2) &&
1377 			!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1378 			mark_tsc_unstable("TSC halts in idle"
1379 					" states deeper than C2");
1380 
1381 		drv->states[drv->state_count] =	/* structure copy */
1382 			cpuidle_state_table[cstate];
1383 
1384 		drv->state_count += 1;
1385 	}
1386 
1387 	if (icpu->byt_auto_demotion_disable_flag) {
1388 		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1389 		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1390 	}
1391 }
1392 
1393 
1394 /*
1395  * intel_idle_cpu_init()
1396  * allocate, initialize, register cpuidle_devices
1397  * @cpu: cpu/core to initialize
1398  */
1399 static int intel_idle_cpu_init(unsigned int cpu)
1400 {
1401 	struct cpuidle_device *dev;
1402 
1403 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1404 	dev->cpu = cpu;
1405 
1406 	if (cpuidle_register_device(dev)) {
1407 		pr_debug("cpuidle_register_device %d failed!\n", cpu);
1408 		return -EIO;
1409 	}
1410 
1411 	if (icpu->auto_demotion_disable_flags)
1412 		auto_demotion_disable();
1413 
1414 	if (icpu->disable_promotion_to_c1e)
1415 		c1e_promotion_disable();
1416 
1417 	return 0;
1418 }
1419 
1420 static int intel_idle_cpu_online(unsigned int cpu)
1421 {
1422 	struct cpuidle_device *dev;
1423 
1424 	if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
1425 		__setup_broadcast_timer(true);
1426 
1427 	/*
1428 	 * Some systems can hotplug a cpu at runtime after
1429 	 * the kernel has booted, we have to initialize the
1430 	 * driver in this case
1431 	 */
1432 	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1433 	if (!dev->registered)
1434 		return intel_idle_cpu_init(cpu);
1435 
1436 	return 0;
1437 }
1438 
1439 static int __init intel_idle_init(void)
1440 {
1441 	int retval;
1442 
1443 	/* Do not load intel_idle at all for now if idle= is passed */
1444 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1445 		return -ENODEV;
1446 
1447 	retval = intel_idle_probe();
1448 	if (retval)
1449 		return retval;
1450 
1451 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1452 	if (intel_idle_cpuidle_devices == NULL)
1453 		return -ENOMEM;
1454 
1455 	intel_idle_cpuidle_driver_init();
1456 	retval = cpuidle_register_driver(&intel_idle_driver);
1457 	if (retval) {
1458 		struct cpuidle_driver *drv = cpuidle_get_driver();
1459 		printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1460 		       drv ? drv->name : "none");
1461 		goto init_driver_fail;
1462 	}
1463 
1464 	if (boot_cpu_has(X86_FEATURE_ARAT))	/* Always Reliable APIC Timer */
1465 		lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
1466 
1467 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1468 				   intel_idle_cpu_online, NULL);
1469 	if (retval < 0)
1470 		goto hp_setup_fail;
1471 
1472 	pr_debug("lapic_timer_reliable_states 0x%x\n",
1473 		 lapic_timer_reliable_states);
1474 
1475 	return 0;
1476 
1477 hp_setup_fail:
1478 	intel_idle_cpuidle_devices_uninit();
1479 	cpuidle_unregister_driver(&intel_idle_driver);
1480 init_driver_fail:
1481 	free_percpu(intel_idle_cpuidle_devices);
1482 	return retval;
1483 
1484 }
1485 device_initcall(intel_idle_init);
1486 
1487 /*
1488  * We are not really modular, but we used to support that.  Meaning we also
1489  * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1490  * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1491  * is the easiest way (currently) to continue doing that.
1492  */
1493 module_param(max_cstate, int, 0444);
1494