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[PATCH] fix missing includes
[linux-2.6-block.git] / drivers / acpi / processor_idle.c
CommitLineData
1da177e4
LT		 1/*
2 * processor_idle - idle state submodule to the ACPI processor driver
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
02df8b93
VP		 9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
1da177e4
LT		 11 *
12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License along
25 * with this program; if not, write to the Free Software Foundation, Inc.,
26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27 *
28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29 */
30
31#include <linux/kernel.h>
32#include <linux/module.h>
33#include <linux/init.h>
34#include <linux/cpufreq.h>
35#include <linux/proc_fs.h>
36#include <linux/seq_file.h>
37#include <linux/acpi.h>
38#include <linux/dmi.h>
39#include <linux/moduleparam.h>
4e57b681 40#include <linux/sched.h> /* need_resched() */
1da177e4
LT		 41
42#include <asm/io.h>
43#include <asm/uaccess.h>
44
45#include <acpi/acpi_bus.h>
46#include <acpi/processor.h>
47
48#define ACPI_PROCESSOR_COMPONENT 0x01000000
49#define ACPI_PROCESSOR_CLASS "processor"
50#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
51#define _COMPONENT ACPI_PROCESSOR_COMPONENT
4be44fcd 52ACPI_MODULE_NAME("acpi_processor")
1da177e4 53#define ACPI_PROCESSOR_FILE_POWER "power"
1da177e4
LT		 54#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
55#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
56#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
4be44fcd 57static void (*pm_idle_save) (void);
1da177e4
LT		 58module_param(max_cstate, uint, 0644);
59
60static unsigned int nocst = 0;
61module_param(nocst, uint, 0000);
62
63/*
64 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
65 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
66 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
67 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
68 * reduce history for more aggressive entry into C3
69 */
4be44fcd
LB		 70static unsigned int bm_history =
71 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
1da177e4
LT		 72module_param(bm_history, uint, 0644);
73/* --------------------------------------------------------------------------
74 Power Management
75 -------------------------------------------------------------------------- */
76
77/*
78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79 * For now disable this. Probably a bug somewhere else.
80 *
81 * To skip this limit, boot/load with a large max_cstate limit.
82 */
335f16be 83static int set_max_cstate(struct dmi_system_id *id)
1da177e4
LT		 84{
85 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
86 return 0;
87
3d35600a 88 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
4be44fcd
LB		 89 " Override with \"processor.max_cstate=%d\"\n", id->ident,
90 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
1da177e4 91
3d35600a 92 max_cstate = (long)id->driver_data;
1da177e4
LT		 93
94 return 0;
95}
96
1da177e4 97static struct dmi_system_id __initdata processor_power_dmi_table[] = {
4be44fcd
LB		 98 {set_max_cstate, "IBM ThinkPad R40e", {
99 DMI_MATCH(DMI_BIOS_VENDOR,
100 "IBM"),
101 DMI_MATCH(DMI_BIOS_VERSION,
102 "1SET60WW")},
103 (void *)1},
104 {set_max_cstate, "Medion 41700", {
105 DMI_MATCH(DMI_BIOS_VENDOR,
106 "Phoenix Technologies LTD"),
107 DMI_MATCH(DMI_BIOS_VERSION,
108 "R01-A1J")}, (void *)1},
109 {set_max_cstate, "Clevo 5600D", {
110 DMI_MATCH(DMI_BIOS_VENDOR,
111 "Phoenix Technologies LTD"),
112 DMI_MATCH(DMI_BIOS_VERSION,
113 "SHE845M0.86C.0013.D.0302131307")},
114 (void *)2},
1da177e4
LT		 115 {},
116};
117
4be44fcd 118static inline u32 ticks_elapsed(u32 t1, u32 t2)
1da177e4
LT		 119{
120 if (t2 >= t1)
121 return (t2 - t1);
122 else if (!acpi_fadt.tmr_val_ext)
123 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
124 else
125 return ((0xFFFFFFFF - t1) + t2);
126}
127
1da177e4 128static void
4be44fcd
LB		 129acpi_processor_power_activate(struct acpi_processor *pr,
130 struct acpi_processor_cx *new)
1da177e4 131{
4be44fcd 132 struct acpi_processor_cx *old;
1da177e4
LT		 133
134 if (!pr || !new)
135 return;
136
137 old = pr->power.state;
138
139 if (old)
140 old->promotion.count = 0;
4be44fcd 141 new->demotion.count = 0;
1da177e4
LT		 142
143 /* Cleanup from old state. */
144 if (old) {
145 switch (old->type) {
146 case ACPI_STATE_C3:
147 /* Disable bus master reload */
02df8b93 148 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
4be44fcd
LB		 149 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
150 ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 151 break;
152 }
153 }
154
155 /* Prepare to use new state. */
156 switch (new->type) {
157 case ACPI_STATE_C3:
158 /* Enable bus master reload */
02df8b93 159 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
4be44fcd
LB		 160 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
161 ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 162 break;
163 }
164
165 pr->power.state = new;
166
167 return;
168}
169
4be44fcd 170static atomic_t c3_cpu_count;
1da177e4 171
4be44fcd 172static void acpi_processor_idle(void)
1da177e4 173{
4be44fcd 174 struct acpi_processor *pr = NULL;
1da177e4
LT		 175 struct acpi_processor_cx *cx = NULL;
176 struct acpi_processor_cx *next_state = NULL;
4be44fcd
LB		 177 int sleep_ticks = 0;
178 u32 t1, t2 = 0;
1da177e4 179
39c715b7 180 pr = processors[raw_smp_processor_id()];
1da177e4
LT		 181 if (!pr)
182 return;
183
184 /*
185 * Interrupts must be disabled during bus mastering calculations and
186 * for C2/C3 transitions.
187 */
188 local_irq_disable();
189
190 /*
191 * Check whether we truly need to go idle, or should
192 * reschedule:
193 */
194 if (unlikely(need_resched())) {
195 local_irq_enable();
196 return;
197 }
198
199 cx = pr->power.state;
200 if (!cx)
201 goto easy_out;
202
203 /*
204 * Check BM Activity
205 * -----------------
206 * Check for bus mastering activity (if required), record, and check
207 * for demotion.
208 */
209 if (pr->flags.bm_check) {
4be44fcd
LB		 210 u32 bm_status = 0;
211 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
1da177e4
LT		 212
213 if (diff > 32)
214 diff = 32;
215
216 while (diff) {
217 /* if we didn't get called, assume there was busmaster activity */
218 diff--;
219 if (diff)
220 pr->power.bm_activity |= 0x1;
221 pr->power.bm_activity <<= 1;
222 }
223
224 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
4be44fcd 225 &bm_status, ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 226 if (bm_status) {
227 pr->power.bm_activity++;
228 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
4be44fcd 229 1, ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 230 }
231 /*
232 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
233 * the true state of bus mastering activity; forcing us to
234 * manually check the BMIDEA bit of each IDE channel.
235 */
236 else if (errata.piix4.bmisx) {
237 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
4be44fcd 238 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
1da177e4
LT		 239 pr->power.bm_activity++;
240 }
241
242 pr->power.bm_check_timestamp = jiffies;
243
244 /*
245 * Apply bus mastering demotion policy. Automatically demote
246 * to avoid a faulty transition. Note that the processor
247 * won't enter a low-power state during this call (to this
248 * funciton) but should upon the next.
249 *
250 * TBD: A better policy might be to fallback to the demotion
251 * state (use it for this quantum only) istead of
252 * demoting -- and rely on duration as our sole demotion
253 * qualification. This may, however, introduce DMA
254 * issues (e.g. floppy DMA transfer overrun/underrun).
255 */
256 if (pr->power.bm_activity & cx->demotion.threshold.bm) {
257 local_irq_enable();
258 next_state = cx->demotion.state;
259 goto end;
260 }
261 }
262
263 cx->usage++;
264
265 /*
266 * Sleep:
267 * ------
268 * Invoke the current Cx state to put the processor to sleep.
269 */
270 switch (cx->type) {
271
272 case ACPI_STATE_C1:
273 /*
274 * Invoke C1.
275 * Use the appropriate idle routine, the one that would
276 * be used without acpi C-states.
277 */
278 if (pm_idle_save)
279 pm_idle_save();
280 else
281 safe_halt();
282 /*
4be44fcd 283 * TBD: Can't get time duration while in C1, as resumes
1da177e4
LT		 284 * go to an ISR rather than here. Need to instrument
285 * base interrupt handler.
286 */
287 sleep_ticks = 0xFFFFFFFF;
288 break;
289
290 case ACPI_STATE_C2:
291 /* Get start time (ticks) */
292 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
293 /* Invoke C2 */
294 inb(cx->address);
295 /* Dummy op - must do something useless after P_LVL2 read */
296 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
297 /* Get end time (ticks) */
298 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
299 /* Re-enable interrupts */
300 local_irq_enable();
301 /* Compute time (ticks) that we were actually asleep */
4be44fcd
LB		 302 sleep_ticks =
303 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
1da177e4
LT		 304 break;
305
306 case ACPI_STATE_C3:
4be44fcd 307
02df8b93
VP		 308 if (pr->flags.bm_check) {
309 if (atomic_inc_return(&c3_cpu_count) ==
4be44fcd 310 num_online_cpus()) {
02df8b93
VP		 311 /*
312 * All CPUs are trying to go to C3
313 * Disable bus master arbitration
314 */
315 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
4be44fcd 316 ACPI_MTX_DO_NOT_LOCK);
02df8b93
VP		 317 }
318 } else {
319 /* SMP with no shared cache... Invalidate cache */
320 ACPI_FLUSH_CPU_CACHE();
321 }
4be44fcd 322
1da177e4
LT		 323 /* Get start time (ticks) */
324 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
325 /* Invoke C3 */
326 inb(cx->address);
327 /* Dummy op - must do something useless after P_LVL3 read */
328 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
329 /* Get end time (ticks) */
330 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
02df8b93
VP		 331 if (pr->flags.bm_check) {
332 /* Enable bus master arbitration */
333 atomic_dec(&c3_cpu_count);
4be44fcd
LB		 334 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
335 ACPI_MTX_DO_NOT_LOCK);
02df8b93
VP		 336 }
337
1da177e4
LT		 338 /* Re-enable interrupts */
339 local_irq_enable();
340 /* Compute time (ticks) that we were actually asleep */
4be44fcd
LB		 341 sleep_ticks =
342 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
1da177e4
LT		 343 break;
344
345 default:
346 local_irq_enable();
347 return;
348 }
349
350 next_state = pr->power.state;
351
352 /*
353 * Promotion?
354 * ----------
355 * Track the number of longs (time asleep is greater than threshold)
356 * and promote when the count threshold is reached. Note that bus
357 * mastering activity may prevent promotions.
358 * Do not promote above max_cstate.
359 */
360 if (cx->promotion.state &&
361 ((cx->promotion.state - pr->power.states) <= max_cstate)) {
362 if (sleep_ticks > cx->promotion.threshold.ticks) {
363 cx->promotion.count++;
4be44fcd
LB		 364 cx->demotion.count = 0;
365 if (cx->promotion.count >=
366 cx->promotion.threshold.count) {
1da177e4 367 if (pr->flags.bm_check) {
4be44fcd
LB		 368 if (!
369 (pr->power.bm_activity & cx->
370 promotion.threshold.bm)) {
371 next_state =
372 cx->promotion.state;
1da177e4
LT		 373 goto end;
374 }
4be44fcd 375 } else {
1da177e4
LT		 376 next_state = cx->promotion.state;
377 goto end;
378 }
379 }
380 }
381 }
382
383 /*
384 * Demotion?
385 * ---------
386 * Track the number of shorts (time asleep is less than time threshold)
387 * and demote when the usage threshold is reached.
388 */
389 if (cx->demotion.state) {
390 if (sleep_ticks < cx->demotion.threshold.ticks) {
391 cx->demotion.count++;
392 cx->promotion.count = 0;
393 if (cx->demotion.count >= cx->demotion.threshold.count) {
394 next_state = cx->demotion.state;
395 goto end;
396 }
397 }
398 }
399
4be44fcd 400 end:
1da177e4
LT		 401 /*
402 * Demote if current state exceeds max_cstate
403 */
404 if ((pr->power.state - pr->power.states) > max_cstate) {
405 if (cx->demotion.state)
406 next_state = cx->demotion.state;
407 }
408
409 /*
410 * New Cx State?
411 * -------------
412 * If we're going to start using a new Cx state we must clean up
413 * from the previous and prepare to use the new.
414 */
415 if (next_state != pr->power.state)
416 acpi_processor_power_activate(pr, next_state);
417
418 return;
419
4be44fcd 420 easy_out:
1da177e4
LT		 421 /* do C1 instead of busy loop */
422 if (pm_idle_save)
423 pm_idle_save();
424 else
425 safe_halt();
426 return;
427}
428
4be44fcd 429static int acpi_processor_set_power_policy(struct acpi_processor *pr)
1da177e4
LT		 430{
431 unsigned int i;
432 unsigned int state_is_set = 0;
433 struct acpi_processor_cx *lower = NULL;
434 struct acpi_processor_cx *higher = NULL;
435 struct acpi_processor_cx *cx;
436
4be44fcd 437 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
1da177e4
LT		 438
439 if (!pr)
440 return_VALUE(-EINVAL);
441
442 /*
443 * This function sets the default Cx state policy (OS idle handler).
444 * Our scheme is to promote quickly to C2 but more conservatively
445 * to C3. We're favoring C2 for its characteristics of low latency
446 * (quick response), good power savings, and ability to allow bus
447 * mastering activity. Note that the Cx state policy is completely
448 * customizable and can be altered dynamically.
449 */
450
451 /* startup state */
4be44fcd 452 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1da177e4
LT		 453 cx = &pr->power.states[i];
454 if (!cx->valid)
455 continue;
456
457 if (!state_is_set)
458 pr->power.state = cx;
459 state_is_set++;
460 break;
4be44fcd 461 }
1da177e4
LT		 462
463 if (!state_is_set)
464 return_VALUE(-ENODEV);
465
466 /* demotion */
4be44fcd 467 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1da177e4
LT		 468 cx = &pr->power.states[i];
469 if (!cx->valid)
470 continue;
471
472 if (lower) {
473 cx->demotion.state = lower;
474 cx->demotion.threshold.ticks = cx->latency_ticks;
475 cx->demotion.threshold.count = 1;
476 if (cx->type == ACPI_STATE_C3)
477 cx->demotion.threshold.bm = bm_history;
478 }
479
480 lower = cx;
481 }
482
483 /* promotion */
484 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
485 cx = &pr->power.states[i];
486 if (!cx->valid)
487 continue;
488
489 if (higher) {
4be44fcd 490 cx->promotion.state = higher;
1da177e4
LT		 491 cx->promotion.threshold.ticks = cx->latency_ticks;
492 if (cx->type >= ACPI_STATE_C2)
493 cx->promotion.threshold.count = 4;
494 else
495 cx->promotion.threshold.count = 10;
496 if (higher->type == ACPI_STATE_C3)
497 cx->promotion.threshold.bm = bm_history;
498 }
499
500 higher = cx;
501 }
502
4be44fcd 503 return_VALUE(0);
1da177e4
LT		 504}
505
4be44fcd 506static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
1da177e4
LT		 507{
508 int i;
509
510 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
511
512 if (!pr)
513 return_VALUE(-EINVAL);
514
515 if (!pr->pblk)
516 return_VALUE(-ENODEV);
517
518 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
519 memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
520
521 /* if info is obtained from pblk/fadt, type equals state */
522 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
523 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
524 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
525
526 /* the C0 state only exists as a filler in our array,
527 * and all processors need to support C1 */
528 pr->power.states[ACPI_STATE_C0].valid = 1;
529 pr->power.states[ACPI_STATE_C1].valid = 1;
530
531 /* determine C2 and C3 address from pblk */
532 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
533 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
534
535 /* determine latencies from FADT */
536 pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
537 pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
538
539 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
540 "lvl2[0x%08x] lvl3[0x%08x]\n",
541 pr->power.states[ACPI_STATE_C2].address,
542 pr->power.states[ACPI_STATE_C3].address));
543
544 return_VALUE(0);
545}
546
4be44fcd 547static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
acf05f4b
VP		 548{
549 int i;
550
551 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
552
553 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
4be44fcd 554 memset(&(pr->power.states[i]), 0,
0b6b2f08 555 sizeof(struct acpi_processor_cx));
acf05f4b
VP		 556
557 /* if info is obtained from pblk/fadt, type equals state */
558 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
559 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
560 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
561
562 /* the C0 state only exists as a filler in our array,
563 * and all processors need to support C1 */
564 pr->power.states[ACPI_STATE_C0].valid = 1;
565 pr->power.states[ACPI_STATE_C1].valid = 1;
566
567 return_VALUE(0);
568}
569
4be44fcd 570static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
1da177e4 571{
4be44fcd
LB		 572 acpi_status status = 0;
573 acpi_integer count;
574 int i;
575 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
576 union acpi_object *cst;
1da177e4
LT		 577
578 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
579
1da177e4
LT		 580 if (nocst)
581 return_VALUE(-ENODEV);
582
583 pr->power.count = 0;
584 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
4be44fcd 585 memset(&(pr->power.states[i]), 0,
0b6b2f08 586 sizeof(struct acpi_processor_cx));
1da177e4
LT		 587
588 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
589 if (ACPI_FAILURE(status)) {
590 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
591 return_VALUE(-ENODEV);
4be44fcd 592 }
1da177e4 593
4be44fcd 594 cst = (union acpi_object *)buffer.pointer;
1da177e4
LT		 595
596 /* There must be at least 2 elements */
597 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
4be44fcd
LB		 598 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
599 "not enough elements in _CST\n"));
1da177e4
LT		 600 status = -EFAULT;
601 goto end;
602 }
603
604 count = cst->package.elements[0].integer.value;
605
606 /* Validate number of power states. */
607 if (count < 1 || count != cst->package.count - 1) {
4be44fcd
LB		 608 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
609 "count given by _CST is not valid\n"));
1da177e4
LT		 610 status = -EFAULT;
611 goto end;
612 }
613
614 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
615 if (count > ACPI_PROCESSOR_MAX_POWER) {
4be44fcd
LB		 616 printk(KERN_WARNING
617 "Limiting number of power states to max (%d)\n",
618 ACPI_PROCESSOR_MAX_POWER);
619 printk(KERN_WARNING
620 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1da177e4
LT		 621 count = ACPI_PROCESSOR_MAX_POWER;
622 }
623
624 /* Tell driver that at least _CST is supported. */
625 pr->flags.has_cst = 1;
626
627 for (i = 1; i <= count; i++) {
628 union acpi_object *element;
629 union acpi_object *obj;
630 struct acpi_power_register *reg;
631 struct acpi_processor_cx cx;
632
633 memset(&cx, 0, sizeof(cx));
634
4be44fcd 635 element = (union acpi_object *)&(cst->package.elements[i]);
1da177e4
LT		 636 if (element->type != ACPI_TYPE_PACKAGE)
637 continue;
638
639 if (element->package.count != 4)
640 continue;
641
4be44fcd 642 obj = (union acpi_object *)&(element->package.elements[0]);
1da177e4
LT		 643
644 if (obj->type != ACPI_TYPE_BUFFER)
645 continue;
646
4be44fcd 647 reg = (struct acpi_power_register *)obj->buffer.pointer;
1da177e4
LT		 648
649 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
4be44fcd 650 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
1da177e4
LT		 651 continue;
652
653 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
4be44fcd 654 0 : reg->address;
1da177e4
LT		 655
656 /* There should be an easy way to extract an integer... */
4be44fcd 657 obj = (union acpi_object *)&(element->package.elements[1]);
1da177e4
LT		 658 if (obj->type != ACPI_TYPE_INTEGER)
659 continue;
660
661 cx.type = obj->integer.value;
662
663 if ((cx.type != ACPI_STATE_C1) &&
664 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
665 continue;
666
4be44fcd 667 if ((cx.type < ACPI_STATE_C1) || (cx.type > ACPI_STATE_C3))
1da177e4
LT		 668 continue;
669
4be44fcd 670 obj = (union acpi_object *)&(element->package.elements[2]);
1da177e4
LT		 671 if (obj->type != ACPI_TYPE_INTEGER)
672 continue;
673
674 cx.latency = obj->integer.value;
675
4be44fcd 676 obj = (union acpi_object *)&(element->package.elements[3]);
1da177e4
LT		 677 if (obj->type != ACPI_TYPE_INTEGER)
678 continue;
679
680 cx.power = obj->integer.value;
681
682 (pr->power.count)++;
683 memcpy(&(pr->power.states[pr->power.count]), &cx, sizeof(cx));
684 }
685
4be44fcd
LB		 686 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
687 pr->power.count));
1da177e4
LT		 688
689 /* Validate number of power states discovered */
690 if (pr->power.count < 2)
691 status = -ENODEV;
692
4be44fcd 693 end:
1da177e4
LT		 694 acpi_os_free(buffer.pointer);
695
696 return_VALUE(status);
697}
698
1da177e4
LT		 699static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
700{
701 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
702
703 if (!cx->address)
704 return_VOID;
705
706 /*
707 * C2 latency must be less than or equal to 100
708 * microseconds.
709 */
710 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
711 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 712 "latency too large [%d]\n", cx->latency));
1da177e4
LT		 713 return_VOID;
714 }
715
1da177e4
LT		 716 /*
717 * Otherwise we've met all of our C2 requirements.
718 * Normalize the C2 latency to expidite policy
719 */
720 cx->valid = 1;
721 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
722
723 return_VOID;
724}
725
4be44fcd
LB		 726static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
727 struct acpi_processor_cx *cx)
1da177e4 728{
02df8b93
VP		 729 static int bm_check_flag;
730
1da177e4
LT		 731 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
732
733 if (!cx->address)
734 return_VOID;
735
736 /*
737 * C3 latency must be less than or equal to 1000
738 * microseconds.
739 */
740 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
741 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 742 "latency too large [%d]\n", cx->latency));
1da177e4
LT		 743 return_VOID;
744 }
745
1da177e4
LT		 746 /*
747 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
748 * DMA transfers are used by any ISA device to avoid livelock.
749 * Note that we could disable Type-F DMA (as recommended by
750 * the erratum), but this is known to disrupt certain ISA
751 * devices thus we take the conservative approach.
752 */
753 else if (errata.piix4.fdma) {
754 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 755 "C3 not supported on PIIX4 with Type-F DMA\n"));
1da177e4
LT		 756 return_VOID;
757 }
758
02df8b93
VP		 759 /* All the logic here assumes flags.bm_check is same across all CPUs */
760 if (!bm_check_flag) {
761 /* Determine whether bm_check is needed based on CPU */
762 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
763 bm_check_flag = pr->flags.bm_check;
764 } else {
765 pr->flags.bm_check = bm_check_flag;
766 }
767
768 if (pr->flags.bm_check) {
02df8b93
VP		 769 /* bus mastering control is necessary */
770 if (!pr->flags.bm_control) {
771 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 772 "C3 support requires bus mastering control\n"));
02df8b93
VP		 773 return_VOID;
774 }
775 } else {
02df8b93
VP		 776 /*
777 * WBINVD should be set in fadt, for C3 state to be
778 * supported on when bm_check is not required.
779 */
780 if (acpi_fadt.wb_invd != 1) {
781 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd
LB		 782 "Cache invalidation should work properly"
783 " for C3 to be enabled on SMP systems\n"));
02df8b93
VP		 784 return_VOID;
785 }
786 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
4be44fcd 787 0, ACPI_MTX_DO_NOT_LOCK);
02df8b93
VP		 788 }
789
1da177e4
LT		 790 /*
791 * Otherwise we've met all of our C3 requirements.
792 * Normalize the C3 latency to expidite policy. Enable
793 * checking of bus mastering status (bm_check) so we can
794 * use this in our C3 policy
795 */
796 cx->valid = 1;
797 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1da177e4
LT		 798
799 return_VOID;
800}
801
1da177e4
LT		 802static int acpi_processor_power_verify(struct acpi_processor *pr)
803{
804 unsigned int i;
805 unsigned int working = 0;
806
4be44fcd 807 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1da177e4
LT		 808 struct acpi_processor_cx *cx = &pr->power.states[i];
809
810 switch (cx->type) {
811 case ACPI_STATE_C1:
812 cx->valid = 1;
813 break;
814
815 case ACPI_STATE_C2:
816 acpi_processor_power_verify_c2(cx);
817 break;
818
819 case ACPI_STATE_C3:
820 acpi_processor_power_verify_c3(pr, cx);
821 break;
822 }
823
824 if (cx->valid)
825 working++;
826 }
827
828 return (working);
829}
830
4be44fcd 831static int acpi_processor_get_power_info(struct acpi_processor *pr)
1da177e4
LT		 832{
833 unsigned int i;
834 int result;
835
836 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
837
838 /* NOTE: the idle thread may not be running while calling
839 * this function */
840
841 result = acpi_processor_get_power_info_cst(pr);
842 if ((result) || (acpi_processor_power_verify(pr) < 2)) {
843 result = acpi_processor_get_power_info_fadt(pr);
4a716402 844 if ((result) || (acpi_processor_power_verify(pr) < 2))
acf05f4b 845 result = acpi_processor_get_power_info_default_c1(pr);
1da177e4
LT		 846 }
847
848 /*
849 * Set Default Policy
850 * ------------------
851 * Now that we know which states are supported, set the default
852 * policy. Note that this policy can be changed dynamically
853 * (e.g. encourage deeper sleeps to conserve battery life when
854 * not on AC).
855 */
856 result = acpi_processor_set_power_policy(pr);
857 if (result)
858 return_VALUE(result);
859
860 /*
861 * if one state of type C2 or C3 is available, mark this
862 * CPU as being "idle manageable"
863 */
864 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
acf05f4b 865 if (pr->power.states[i].valid) {
1da177e4 866 pr->power.count = i;
1da177e4 867 pr->flags.power = 1;
acf05f4b 868 }
1da177e4
LT		 869 }
870
871 return_VALUE(0);
872}
873
4be44fcd 874int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1da177e4 875{
4be44fcd 876 int result = 0;
1da177e4
LT		 877
878 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
879
880 if (!pr)
4be44fcd 881 return_VALUE(-EINVAL);
1da177e4 882
4be44fcd 883 if (nocst) {
1da177e4
LT		 884 return_VALUE(-ENODEV);
885 }
886
887 if (!pr->flags.power_setup_done)
888 return_VALUE(-ENODEV);
889
890 /* Fall back to the default idle loop */
891 pm_idle = pm_idle_save;
4be44fcd 892 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
1da177e4
LT		 893
894 pr->flags.power = 0;
895 result = acpi_processor_get_power_info(pr);
896 if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
897 pm_idle = acpi_processor_idle;
898
899 return_VALUE(result);
900}
901
902/* proc interface */
903
904static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
905{
4be44fcd
LB		 906 struct acpi_processor *pr = (struct acpi_processor *)seq->private;
907 unsigned int i;
1da177e4
LT		 908
909 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
910
911 if (!pr)
912 goto end;
913
914 seq_printf(seq, "active state: C%zd\n"
4be44fcd
LB		 915 "max_cstate: C%d\n"
916 "bus master activity: %08x\n",
917 pr->power.state ? pr->power.state - pr->power.states : 0,
918 max_cstate, (unsigned)pr->power.bm_activity);
1da177e4
LT		 919
920 seq_puts(seq, "states:\n");
921
922 for (i = 1; i <= pr->power.count; i++) {
923 seq_printf(seq, " %cC%d: ",
4be44fcd
LB		 924 (&pr->power.states[i] ==
925 pr->power.state ? '*' : ' '), i);
1da177e4
LT		 926
927 if (!pr->power.states[i].valid) {
928 seq_puts(seq, "<not supported>\n");
929 continue;
930 }
931
932 switch (pr->power.states[i].type) {
933 case ACPI_STATE_C1:
934 seq_printf(seq, "type[C1] ");
935 break;
936 case ACPI_STATE_C2:
937 seq_printf(seq, "type[C2] ");
938 break;
939 case ACPI_STATE_C3:
940 seq_printf(seq, "type[C3] ");
941 break;
942 default:
943 seq_printf(seq, "type[--] ");
944 break;
945 }
946
947 if (pr->power.states[i].promotion.state)
948 seq_printf(seq, "promotion[C%zd] ",
4be44fcd
LB		 949 (pr->power.states[i].promotion.state -
950 pr->power.states));
1da177e4
LT		 951 else
952 seq_puts(seq, "promotion[--] ");
953
954 if (pr->power.states[i].demotion.state)
955 seq_printf(seq, "demotion[C%zd] ",
4be44fcd
LB		 956 (pr->power.states[i].demotion.state -
957 pr->power.states));
1da177e4
LT		 958 else
959 seq_puts(seq, "demotion[--] ");
960
961 seq_printf(seq, "latency[%03d] usage[%08d]\n",
4be44fcd
LB		 962 pr->power.states[i].latency,
963 pr->power.states[i].usage);
1da177e4
LT		 964 }
965
4be44fcd 966 end:
1da177e4
LT		 967 return_VALUE(0);
968}
969
970static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
971{
972 return single_open(file, acpi_processor_power_seq_show,
4be44fcd 973 PDE(inode)->data);
1da177e4
LT		 974}
975
976static struct file_operations acpi_processor_power_fops = {
4be44fcd
LB		 977 .open = acpi_processor_power_open_fs,
978 .read = seq_read,
979 .llseek = seq_lseek,
980 .release = single_release,
1da177e4
LT		 981};
982
4be44fcd
LB		 983int acpi_processor_power_init(struct acpi_processor *pr,
984 struct acpi_device *device)
1da177e4 985{
4be44fcd
LB		 986 acpi_status status = 0;
987 static int first_run = 0;
988 struct proc_dir_entry *entry = NULL;
1da177e4
LT		 989 unsigned int i;
990
991 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
992
993 if (!first_run) {
994 dmi_check_system(processor_power_dmi_table);
995 if (max_cstate < ACPI_C_STATES_MAX)
4be44fcd
LB		 996 printk(KERN_NOTICE
997 "ACPI: processor limited to max C-state %d\n",
998 max_cstate);
1da177e4
LT		 999 first_run++;
1000 }
1001
02df8b93
VP		 1002 if (!pr)
1003 return_VALUE(-EINVAL);
1004
1005 if (acpi_fadt.cst_cnt && !nocst) {
4be44fcd
LB		 1006 status =
1007 acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1da177e4
LT		 1008 if (ACPI_FAILURE(status)) {
1009 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1010 "Notifying BIOS of _CST ability failed\n"));
1011 }
1012 }
1013
02df8b93
VP		 1014 acpi_processor_power_init_pdc(&(pr->power), pr->id);
1015 acpi_processor_set_pdc(pr, pr->power.pdc);
1da177e4
LT		 1016 acpi_processor_get_power_info(pr);
1017
1018 /*
1019 * Install the idle handler if processor power management is supported.
1020 * Note that we use previously set idle handler will be used on
1021 * platforms that only support C1.
1022 */
1023 if ((pr->flags.power) && (!boot_option_idle_override)) {
1024 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1025 for (i = 1; i <= pr->power.count; i++)
1026 if (pr->power.states[i].valid)
4be44fcd
LB		 1027 printk(" C%d[C%d]", i,
1028 pr->power.states[i].type);
1da177e4
LT		 1029 printk(")\n");
1030
1031 if (pr->id == 0) {
1032 pm_idle_save = pm_idle;
1033 pm_idle = acpi_processor_idle;
1034 }
1035 }
1036
1037 /* 'power' [R] */
1038 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
4be44fcd 1039 S_IRUGO, acpi_device_dir(device));
1da177e4
LT		 1040 if (!entry)
1041 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
4be44fcd
LB		 1042 "Unable to create '%s' fs entry\n",
1043 ACPI_PROCESSOR_FILE_POWER));
1da177e4
LT		 1044 else {
1045 entry->proc_fops = &acpi_processor_power_fops;
1046 entry->data = acpi_driver_data(device);
1047 entry->owner = THIS_MODULE;
1048 }
1049
1050 pr->flags.power_setup_done = 1;
1051
1052 return_VALUE(0);
1053}
1054
4be44fcd
LB		 1055int acpi_processor_power_exit(struct acpi_processor *pr,
1056 struct acpi_device *device)
1da177e4
LT		 1057{
1058 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1059
1060 pr->flags.power_setup_done = 0;
1061
1062 if (acpi_device_dir(device))
4be44fcd
LB		 1063 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1064 acpi_device_dir(device));
1da177e4
LT		 1065
1066 /* Unregister the idle handler when processor #0 is removed. */
1067 if (pr->id == 0) {
1068 pm_idle = pm_idle_save;
1069
1070 /*
1071 * We are about to unload the current idle thread pm callback
1072 * (pm_idle), Wait for all processors to update cached/local
1073 * copies of pm_idle before proceeding.
1074 */
1075 cpu_idle_wait();
1076 }
1077
1078 return_VALUE(0);
1079}
Linux 6.x block layer and io_uring tree(s)