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ACPI: delete tracing macros from drivers/acpi/*.c
[deliverable/linux.git] / drivers / acpi / processor_idle.c
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
9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
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>
40 #include <linux/sched.h> /* need_resched() */
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
52 ACPI_MODULE_NAME("acpi_processor")
53 #define ACPI_PROCESSOR_FILE_POWER "power"
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) */
57 static void (*pm_idle_save) (void) __read_mostly;
58 module_param(max_cstate, uint, 0644);
59
60 static unsigned int nocst __read_mostly;
61 module_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 */
70 static unsigned int bm_history __read_mostly =
71 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
72 module_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 */
83 static int set_max_cstate(struct dmi_system_id *id)
84 {
85 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
86 return 0;
87
88 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
89 " Override with \"processor.max_cstate=%d\"\n", id->ident,
90 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
91
92 max_cstate = (long)id->driver_data;
93
94 return 0;
95 }
96
97 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
98 callers to only run once -AK */
99 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
100 { set_max_cstate, "IBM ThinkPad R40e", {
101 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
102 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
103 { set_max_cstate, "IBM ThinkPad R40e", {
104 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
105 DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
106 { set_max_cstate, "IBM ThinkPad R40e", {
107 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
108 DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
109 { set_max_cstate, "IBM ThinkPad R40e", {
110 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
111 DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
112 { set_max_cstate, "IBM ThinkPad R40e", {
113 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
114 DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
115 { set_max_cstate, "IBM ThinkPad R40e", {
116 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
117 DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
118 { set_max_cstate, "IBM ThinkPad R40e", {
119 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
120 DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
121 { set_max_cstate, "IBM ThinkPad R40e", {
122 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
123 DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
124 { set_max_cstate, "IBM ThinkPad R40e", {
125 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
126 DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
127 { set_max_cstate, "IBM ThinkPad R40e", {
128 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
129 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
130 { set_max_cstate, "IBM ThinkPad R40e", {
131 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
132 DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
133 { set_max_cstate, "IBM ThinkPad R40e", {
134 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
135 DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
136 { set_max_cstate, "IBM ThinkPad R40e", {
137 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
138 DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
139 { set_max_cstate, "IBM ThinkPad R40e", {
140 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
141 DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
142 { set_max_cstate, "IBM ThinkPad R40e", {
143 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
144 DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
145 { set_max_cstate, "Medion 41700", {
146 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
147 DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
148 { set_max_cstate, "Clevo 5600D", {
149 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
150 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
151 (void *)2},
152 {},
153 };
154
155 static inline u32 ticks_elapsed(u32 t1, u32 t2)
156 {
157 if (t2 >= t1)
158 return (t2 - t1);
159 else if (!acpi_fadt.tmr_val_ext)
160 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
161 else
162 return ((0xFFFFFFFF - t1) + t2);
163 }
164
165 static void
166 acpi_processor_power_activate(struct acpi_processor *pr,
167 struct acpi_processor_cx *new)
168 {
169 struct acpi_processor_cx *old;
170
171 if (!pr || !new)
172 return;
173
174 old = pr->power.state;
175
176 if (old)
177 old->promotion.count = 0;
178 new->demotion.count = 0;
179
180 /* Cleanup from old state. */
181 if (old) {
182 switch (old->type) {
183 case ACPI_STATE_C3:
184 /* Disable bus master reload */
185 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
186 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
187 ACPI_MTX_DO_NOT_LOCK);
188 break;
189 }
190 }
191
192 /* Prepare to use new state. */
193 switch (new->type) {
194 case ACPI_STATE_C3:
195 /* Enable bus master reload */
196 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
197 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
198 ACPI_MTX_DO_NOT_LOCK);
199 break;
200 }
201
202 pr->power.state = new;
203
204 return;
205 }
206
207 static void acpi_safe_halt(void)
208 {
209 current_thread_info()->status &= ~TS_POLLING;
210 smp_mb__after_clear_bit();
211 if (!need_resched())
212 safe_halt();
213 current_thread_info()->status |= TS_POLLING;
214 }
215
216 static atomic_t c3_cpu_count;
217
218 static void acpi_processor_idle(void)
219 {
220 struct acpi_processor *pr = NULL;
221 struct acpi_processor_cx *cx = NULL;
222 struct acpi_processor_cx *next_state = NULL;
223 int sleep_ticks = 0;
224 u32 t1, t2 = 0;
225
226 pr = processors[smp_processor_id()];
227 if (!pr)
228 return;
229
230 /*
231 * Interrupts must be disabled during bus mastering calculations and
232 * for C2/C3 transitions.
233 */
234 local_irq_disable();
235
236 /*
237 * Check whether we truly need to go idle, or should
238 * reschedule:
239 */
240 if (unlikely(need_resched())) {
241 local_irq_enable();
242 return;
243 }
244
245 cx = pr->power.state;
246 if (!cx) {
247 if (pm_idle_save)
248 pm_idle_save();
249 else
250 acpi_safe_halt();
251 return;
252 }
253
254 /*
255 * Check BM Activity
256 * -----------------
257 * Check for bus mastering activity (if required), record, and check
258 * for demotion.
259 */
260 if (pr->flags.bm_check) {
261 u32 bm_status = 0;
262 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
263
264 if (diff > 32)
265 diff = 32;
266
267 while (diff) {
268 /* if we didn't get called, assume there was busmaster activity */
269 diff--;
270 if (diff)
271 pr->power.bm_activity |= 0x1;
272 pr->power.bm_activity <<= 1;
273 }
274
275 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
276 &bm_status, ACPI_MTX_DO_NOT_LOCK);
277 if (bm_status) {
278 pr->power.bm_activity++;
279 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
280 1, ACPI_MTX_DO_NOT_LOCK);
281 }
282 /*
283 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
284 * the true state of bus mastering activity; forcing us to
285 * manually check the BMIDEA bit of each IDE channel.
286 */
287 else if (errata.piix4.bmisx) {
288 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
289 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
290 pr->power.bm_activity++;
291 }
292
293 pr->power.bm_check_timestamp = jiffies;
294
295 /*
296 * Apply bus mastering demotion policy. Automatically demote
297 * to avoid a faulty transition. Note that the processor
298 * won't enter a low-power state during this call (to this
299 * funciton) but should upon the next.
300 *
301 * TBD: A better policy might be to fallback to the demotion
302 * state (use it for this quantum only) istead of
303 * demoting -- and rely on duration as our sole demotion
304 * qualification. This may, however, introduce DMA
305 * issues (e.g. floppy DMA transfer overrun/underrun).
306 */
307 if (pr->power.bm_activity & cx->demotion.threshold.bm) {
308 local_irq_enable();
309 next_state = cx->demotion.state;
310 goto end;
311 }
312 }
313
314 #ifdef CONFIG_HOTPLUG_CPU
315 /*
316 * Check for P_LVL2_UP flag before entering C2 and above on
317 * an SMP system. We do it here instead of doing it at _CST/P_LVL
318 * detection phase, to work cleanly with logical CPU hotplug.
319 */
320 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
321 !pr->flags.has_cst && !acpi_fadt.plvl2_up)
322 cx = &pr->power.states[ACPI_STATE_C1];
323 #endif
324
325 cx->usage++;
326
327 /*
328 * Sleep:
329 * ------
330 * Invoke the current Cx state to put the processor to sleep.
331 */
332 if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
333 current_thread_info()->status &= ~TS_POLLING;
334 smp_mb__after_clear_bit();
335 if (need_resched()) {
336 current_thread_info()->status |= TS_POLLING;
337 local_irq_enable();
338 return;
339 }
340 }
341
342 switch (cx->type) {
343
344 case ACPI_STATE_C1:
345 /*
346 * Invoke C1.
347 * Use the appropriate idle routine, the one that would
348 * be used without acpi C-states.
349 */
350 if (pm_idle_save)
351 pm_idle_save();
352 else
353 acpi_safe_halt();
354
355 /*
356 * TBD: Can't get time duration while in C1, as resumes
357 * go to an ISR rather than here. Need to instrument
358 * base interrupt handler.
359 */
360 sleep_ticks = 0xFFFFFFFF;
361 break;
362
363 case ACPI_STATE_C2:
364 /* Get start time (ticks) */
365 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
366 /* Invoke C2 */
367 inb(cx->address);
368 /* Dummy op - must do something useless after P_LVL2 read */
369 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
370 /* Get end time (ticks) */
371 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
372
373 #ifdef CONFIG_GENERIC_TIME
374 /* TSC halts in C2, so notify users */
375 mark_tsc_unstable();
376 #endif
377 /* Re-enable interrupts */
378 local_irq_enable();
379 current_thread_info()->status |= TS_POLLING;
380 /* Compute time (ticks) that we were actually asleep */
381 sleep_ticks =
382 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
383 break;
384
385 case ACPI_STATE_C3:
386
387 if (pr->flags.bm_check) {
388 if (atomic_inc_return(&c3_cpu_count) ==
389 num_online_cpus()) {
390 /*
391 * All CPUs are trying to go to C3
392 * Disable bus master arbitration
393 */
394 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
395 ACPI_MTX_DO_NOT_LOCK);
396 }
397 } else {
398 /* SMP with no shared cache... Invalidate cache */
399 ACPI_FLUSH_CPU_CACHE();
400 }
401
402 /* Get start time (ticks) */
403 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
404 /* Invoke C3 */
405 inb(cx->address);
406 /* Dummy op - must do something useless after P_LVL3 read */
407 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
408 /* Get end time (ticks) */
409 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
410 if (pr->flags.bm_check) {
411 /* Enable bus master arbitration */
412 atomic_dec(&c3_cpu_count);
413 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
414 ACPI_MTX_DO_NOT_LOCK);
415 }
416
417 #ifdef CONFIG_GENERIC_TIME
418 /* TSC halts in C3, so notify users */
419 mark_tsc_unstable();
420 #endif
421 /* Re-enable interrupts */
422 local_irq_enable();
423 current_thread_info()->status |= TS_POLLING;
424 /* Compute time (ticks) that we were actually asleep */
425 sleep_ticks =
426 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
427 break;
428
429 default:
430 local_irq_enable();
431 return;
432 }
433
434 next_state = pr->power.state;
435
436 #ifdef CONFIG_HOTPLUG_CPU
437 /* Don't do promotion/demotion */
438 if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
439 !pr->flags.has_cst && !acpi_fadt.plvl2_up) {
440 next_state = cx;
441 goto end;
442 }
443 #endif
444
445 /*
446 * Promotion?
447 * ----------
448 * Track the number of longs (time asleep is greater than threshold)
449 * and promote when the count threshold is reached. Note that bus
450 * mastering activity may prevent promotions.
451 * Do not promote above max_cstate.
452 */
453 if (cx->promotion.state &&
454 ((cx->promotion.state - pr->power.states) <= max_cstate)) {
455 if (sleep_ticks > cx->promotion.threshold.ticks) {
456 cx->promotion.count++;
457 cx->demotion.count = 0;
458 if (cx->promotion.count >=
459 cx->promotion.threshold.count) {
460 if (pr->flags.bm_check) {
461 if (!
462 (pr->power.bm_activity & cx->
463 promotion.threshold.bm)) {
464 next_state =
465 cx->promotion.state;
466 goto end;
467 }
468 } else {
469 next_state = cx->promotion.state;
470 goto end;
471 }
472 }
473 }
474 }
475
476 /*
477 * Demotion?
478 * ---------
479 * Track the number of shorts (time asleep is less than time threshold)
480 * and demote when the usage threshold is reached.
481 */
482 if (cx->demotion.state) {
483 if (sleep_ticks < cx->demotion.threshold.ticks) {
484 cx->demotion.count++;
485 cx->promotion.count = 0;
486 if (cx->demotion.count >= cx->demotion.threshold.count) {
487 next_state = cx->demotion.state;
488 goto end;
489 }
490 }
491 }
492
493 end:
494 /*
495 * Demote if current state exceeds max_cstate
496 */
497 if ((pr->power.state - pr->power.states) > max_cstate) {
498 if (cx->demotion.state)
499 next_state = cx->demotion.state;
500 }
501
502 /*
503 * New Cx State?
504 * -------------
505 * If we're going to start using a new Cx state we must clean up
506 * from the previous and prepare to use the new.
507 */
508 if (next_state != pr->power.state)
509 acpi_processor_power_activate(pr, next_state);
510 }
511
512 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
513 {
514 unsigned int i;
515 unsigned int state_is_set = 0;
516 struct acpi_processor_cx *lower = NULL;
517 struct acpi_processor_cx *higher = NULL;
518 struct acpi_processor_cx *cx;
519
520
521 if (!pr)
522 return -EINVAL;
523
524 /*
525 * This function sets the default Cx state policy (OS idle handler).
526 * Our scheme is to promote quickly to C2 but more conservatively
527 * to C3. We're favoring C2 for its characteristics of low latency
528 * (quick response), good power savings, and ability to allow bus
529 * mastering activity. Note that the Cx state policy is completely
530 * customizable and can be altered dynamically.
531 */
532
533 /* startup state */
534 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
535 cx = &pr->power.states[i];
536 if (!cx->valid)
537 continue;
538
539 if (!state_is_set)
540 pr->power.state = cx;
541 state_is_set++;
542 break;
543 }
544
545 if (!state_is_set)
546 return -ENODEV;
547
548 /* demotion */
549 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
550 cx = &pr->power.states[i];
551 if (!cx->valid)
552 continue;
553
554 if (lower) {
555 cx->demotion.state = lower;
556 cx->demotion.threshold.ticks = cx->latency_ticks;
557 cx->demotion.threshold.count = 1;
558 if (cx->type == ACPI_STATE_C3)
559 cx->demotion.threshold.bm = bm_history;
560 }
561
562 lower = cx;
563 }
564
565 /* promotion */
566 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
567 cx = &pr->power.states[i];
568 if (!cx->valid)
569 continue;
570
571 if (higher) {
572 cx->promotion.state = higher;
573 cx->promotion.threshold.ticks = cx->latency_ticks;
574 if (cx->type >= ACPI_STATE_C2)
575 cx->promotion.threshold.count = 4;
576 else
577 cx->promotion.threshold.count = 10;
578 if (higher->type == ACPI_STATE_C3)
579 cx->promotion.threshold.bm = bm_history;
580 }
581
582 higher = cx;
583 }
584
585 return 0;
586 }
587
588 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
589 {
590
591 if (!pr)
592 return -EINVAL;
593
594 if (!pr->pblk)
595 return -ENODEV;
596
597 /* if info is obtained from pblk/fadt, type equals state */
598 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
599 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
600
601 #ifndef CONFIG_HOTPLUG_CPU
602 /*
603 * Check for P_LVL2_UP flag before entering C2 and above on
604 * an SMP system.
605 */
606 if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up)
607 return -ENODEV;
608 #endif
609
610 /* determine C2 and C3 address from pblk */
611 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
612 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
613
614 /* determine latencies from FADT */
615 pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
616 pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
617
618 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
619 "lvl2[0x%08x] lvl3[0x%08x]\n",
620 pr->power.states[ACPI_STATE_C2].address,
621 pr->power.states[ACPI_STATE_C3].address));
622
623 return 0;
624 }
625
626 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
627 {
628
629 /* Zero initialize all the C-states info. */
630 memset(pr->power.states, 0, sizeof(pr->power.states));
631
632 /* set the first C-State to C1 */
633 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
634
635 /* the C0 state only exists as a filler in our array,
636 * and all processors need to support C1 */
637 pr->power.states[ACPI_STATE_C0].valid = 1;
638 pr->power.states[ACPI_STATE_C1].valid = 1;
639
640 return 0;
641 }
642
643 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
644 {
645 acpi_status status = 0;
646 acpi_integer count;
647 int current_count;
648 int i;
649 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
650 union acpi_object *cst;
651
652
653 if (nocst)
654 return -ENODEV;
655
656 current_count = 1;
657
658 /* Zero initialize C2 onwards and prepare for fresh CST lookup */
659 for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++)
660 memset(&(pr->power.states[i]), 0,
661 sizeof(struct acpi_processor_cx));
662
663 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
664 if (ACPI_FAILURE(status)) {
665 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
666 return -ENODEV;
667 }
668
669 cst = (union acpi_object *)buffer.pointer;
670
671 /* There must be at least 2 elements */
672 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
673 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
674 status = -EFAULT;
675 goto end;
676 }
677
678 count = cst->package.elements[0].integer.value;
679
680 /* Validate number of power states. */
681 if (count < 1 || count != cst->package.count - 1) {
682 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
683 status = -EFAULT;
684 goto end;
685 }
686
687 /* Tell driver that at least _CST is supported. */
688 pr->flags.has_cst = 1;
689
690 for (i = 1; i <= count; i++) {
691 union acpi_object *element;
692 union acpi_object *obj;
693 struct acpi_power_register *reg;
694 struct acpi_processor_cx cx;
695
696 memset(&cx, 0, sizeof(cx));
697
698 element = (union acpi_object *)&(cst->package.elements[i]);
699 if (element->type != ACPI_TYPE_PACKAGE)
700 continue;
701
702 if (element->package.count != 4)
703 continue;
704
705 obj = (union acpi_object *)&(element->package.elements[0]);
706
707 if (obj->type != ACPI_TYPE_BUFFER)
708 continue;
709
710 reg = (struct acpi_power_register *)obj->buffer.pointer;
711
712 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
713 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
714 continue;
715
716 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
717 0 : reg->address;
718
719 /* There should be an easy way to extract an integer... */
720 obj = (union acpi_object *)&(element->package.elements[1]);
721 if (obj->type != ACPI_TYPE_INTEGER)
722 continue;
723
724 cx.type = obj->integer.value;
725
726 if ((cx.type != ACPI_STATE_C1) &&
727 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
728 continue;
729
730 if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3))
731 continue;
732
733 obj = (union acpi_object *)&(element->package.elements[2]);
734 if (obj->type != ACPI_TYPE_INTEGER)
735 continue;
736
737 cx.latency = obj->integer.value;
738
739 obj = (union acpi_object *)&(element->package.elements[3]);
740 if (obj->type != ACPI_TYPE_INTEGER)
741 continue;
742
743 cx.power = obj->integer.value;
744
745 current_count++;
746 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
747
748 /*
749 * We support total ACPI_PROCESSOR_MAX_POWER - 1
750 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
751 */
752 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
753 printk(KERN_WARNING
754 "Limiting number of power states to max (%d)\n",
755 ACPI_PROCESSOR_MAX_POWER);
756 printk(KERN_WARNING
757 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
758 break;
759 }
760 }
761
762 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
763 current_count));
764
765 /* Validate number of power states discovered */
766 if (current_count < 2)
767 status = -EFAULT;
768
769 end:
770 acpi_os_free(buffer.pointer);
771
772 return status;
773 }
774
775 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
776 {
777
778 if (!cx->address)
779 return;
780
781 /*
782 * C2 latency must be less than or equal to 100
783 * microseconds.
784 */
785 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
786 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
787 "latency too large [%d]\n", cx->latency));
788 return;
789 }
790
791 /*
792 * Otherwise we've met all of our C2 requirements.
793 * Normalize the C2 latency to expidite policy
794 */
795 cx->valid = 1;
796 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
797
798 return;
799 }
800
801 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
802 struct acpi_processor_cx *cx)
803 {
804 static int bm_check_flag;
805
806
807 if (!cx->address)
808 return;
809
810 /*
811 * C3 latency must be less than or equal to 1000
812 * microseconds.
813 */
814 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
815 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
816 "latency too large [%d]\n", cx->latency));
817 return;
818 }
819
820 /*
821 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
822 * DMA transfers are used by any ISA device to avoid livelock.
823 * Note that we could disable Type-F DMA (as recommended by
824 * the erratum), but this is known to disrupt certain ISA
825 * devices thus we take the conservative approach.
826 */
827 else if (errata.piix4.fdma) {
828 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
829 "C3 not supported on PIIX4 with Type-F DMA\n"));
830 return;
831 }
832
833 /* All the logic here assumes flags.bm_check is same across all CPUs */
834 if (!bm_check_flag) {
835 /* Determine whether bm_check is needed based on CPU */
836 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
837 bm_check_flag = pr->flags.bm_check;
838 } else {
839 pr->flags.bm_check = bm_check_flag;
840 }
841
842 if (pr->flags.bm_check) {
843 /* bus mastering control is necessary */
844 if (!pr->flags.bm_control) {
845 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
846 "C3 support requires bus mastering control\n"));
847 return;
848 }
849 } else {
850 /*
851 * WBINVD should be set in fadt, for C3 state to be
852 * supported on when bm_check is not required.
853 */
854 if (acpi_fadt.wb_invd != 1) {
855 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
856 "Cache invalidation should work properly"
857 " for C3 to be enabled on SMP systems\n"));
858 return;
859 }
860 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
861 0, ACPI_MTX_DO_NOT_LOCK);
862 }
863
864 /*
865 * Otherwise we've met all of our C3 requirements.
866 * Normalize the C3 latency to expidite policy. Enable
867 * checking of bus mastering status (bm_check) so we can
868 * use this in our C3 policy
869 */
870 cx->valid = 1;
871 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
872
873 return;
874 }
875
876 static int acpi_processor_power_verify(struct acpi_processor *pr)
877 {
878 unsigned int i;
879 unsigned int working = 0;
880
881 #ifdef ARCH_APICTIMER_STOPS_ON_C3
882 int timer_broadcast = 0;
883 cpumask_t mask = cpumask_of_cpu(pr->id);
884 on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
885 #endif
886
887 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
888 struct acpi_processor_cx *cx = &pr->power.states[i];
889
890 switch (cx->type) {
891 case ACPI_STATE_C1:
892 cx->valid = 1;
893 break;
894
895 case ACPI_STATE_C2:
896 acpi_processor_power_verify_c2(cx);
897 #ifdef ARCH_APICTIMER_STOPS_ON_C3
898 /* Some AMD systems fake C3 as C2, but still
899 have timer troubles */
900 if (cx->valid &&
901 boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
902 timer_broadcast++;
903 #endif
904 break;
905
906 case ACPI_STATE_C3:
907 acpi_processor_power_verify_c3(pr, cx);
908 #ifdef ARCH_APICTIMER_STOPS_ON_C3
909 if (cx->valid)
910 timer_broadcast++;
911 #endif
912 break;
913 }
914
915 if (cx->valid)
916 working++;
917 }
918
919 #ifdef ARCH_APICTIMER_STOPS_ON_C3
920 if (timer_broadcast)
921 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
922 #endif
923
924 return (working);
925 }
926
927 static int acpi_processor_get_power_info(struct acpi_processor *pr)
928 {
929 unsigned int i;
930 int result;
931
932
933 /* NOTE: the idle thread may not be running while calling
934 * this function */
935
936 /* Adding C1 state */
937 acpi_processor_get_power_info_default_c1(pr);
938 result = acpi_processor_get_power_info_cst(pr);
939 if (result == -ENODEV)
940 acpi_processor_get_power_info_fadt(pr);
941
942 pr->power.count = acpi_processor_power_verify(pr);
943
944 /*
945 * Set Default Policy
946 * ------------------
947 * Now that we know which states are supported, set the default
948 * policy. Note that this policy can be changed dynamically
949 * (e.g. encourage deeper sleeps to conserve battery life when
950 * not on AC).
951 */
952 result = acpi_processor_set_power_policy(pr);
953 if (result)
954 return result;
955
956 /*
957 * if one state of type C2 or C3 is available, mark this
958 * CPU as being "idle manageable"
959 */
960 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
961 if (pr->power.states[i].valid) {
962 pr->power.count = i;
963 if (pr->power.states[i].type >= ACPI_STATE_C2)
964 pr->flags.power = 1;
965 }
966 }
967
968 return 0;
969 }
970
971 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
972 {
973 int result = 0;
974
975
976 if (!pr)
977 return -EINVAL;
978
979 if (nocst) {
980 return -ENODEV;
981 }
982
983 if (!pr->flags.power_setup_done)
984 return -ENODEV;
985
986 /* Fall back to the default idle loop */
987 pm_idle = pm_idle_save;
988 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
989
990 pr->flags.power = 0;
991 result = acpi_processor_get_power_info(pr);
992 if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
993 pm_idle = acpi_processor_idle;
994
995 return result;
996 }
997
998 /* proc interface */
999
1000 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1001 {
1002 struct acpi_processor *pr = (struct acpi_processor *)seq->private;
1003 unsigned int i;
1004
1005
1006 if (!pr)
1007 goto end;
1008
1009 seq_printf(seq, "active state: C%zd\n"
1010 "max_cstate: C%d\n"
1011 "bus master activity: %08x\n",
1012 pr->power.state ? pr->power.state - pr->power.states : 0,
1013 max_cstate, (unsigned)pr->power.bm_activity);
1014
1015 seq_puts(seq, "states:\n");
1016
1017 for (i = 1; i <= pr->power.count; i++) {
1018 seq_printf(seq, " %cC%d: ",
1019 (&pr->power.states[i] ==
1020 pr->power.state ? '*' : ' '), i);
1021
1022 if (!pr->power.states[i].valid) {
1023 seq_puts(seq, "<not supported>\n");
1024 continue;
1025 }
1026
1027 switch (pr->power.states[i].type) {
1028 case ACPI_STATE_C1:
1029 seq_printf(seq, "type[C1] ");
1030 break;
1031 case ACPI_STATE_C2:
1032 seq_printf(seq, "type[C2] ");
1033 break;
1034 case ACPI_STATE_C3:
1035 seq_printf(seq, "type[C3] ");
1036 break;
1037 default:
1038 seq_printf(seq, "type[--] ");
1039 break;
1040 }
1041
1042 if (pr->power.states[i].promotion.state)
1043 seq_printf(seq, "promotion[C%zd] ",
1044 (pr->power.states[i].promotion.state -
1045 pr->power.states));
1046 else
1047 seq_puts(seq, "promotion[--] ");
1048
1049 if (pr->power.states[i].demotion.state)
1050 seq_printf(seq, "demotion[C%zd] ",
1051 (pr->power.states[i].demotion.state -
1052 pr->power.states));
1053 else
1054 seq_puts(seq, "demotion[--] ");
1055
1056 seq_printf(seq, "latency[%03d] usage[%08d]\n",
1057 pr->power.states[i].latency,
1058 pr->power.states[i].usage);
1059 }
1060
1061 end:
1062 return 0;
1063 }
1064
1065 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1066 {
1067 return single_open(file, acpi_processor_power_seq_show,
1068 PDE(inode)->data);
1069 }
1070
1071 static struct file_operations acpi_processor_power_fops = {
1072 .open = acpi_processor_power_open_fs,
1073 .read = seq_read,
1074 .llseek = seq_lseek,
1075 .release = single_release,
1076 };
1077
1078 int acpi_processor_power_init(struct acpi_processor *pr,
1079 struct acpi_device *device)
1080 {
1081 acpi_status status = 0;
1082 static int first_run;
1083 struct proc_dir_entry *entry = NULL;
1084 unsigned int i;
1085
1086
1087 if (!first_run) {
1088 dmi_check_system(processor_power_dmi_table);
1089 if (max_cstate < ACPI_C_STATES_MAX)
1090 printk(KERN_NOTICE
1091 "ACPI: processor limited to max C-state %d\n",
1092 max_cstate);
1093 first_run++;
1094 }
1095
1096 if (!pr)
1097 return -EINVAL;
1098
1099 if (acpi_fadt.cst_cnt && !nocst) {
1100 status =
1101 acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1102 if (ACPI_FAILURE(status)) {
1103 ACPI_EXCEPTION((AE_INFO, status,
1104 "Notifying BIOS of _CST ability failed"));
1105 }
1106 }
1107
1108 acpi_processor_get_power_info(pr);
1109
1110 /*
1111 * Install the idle handler if processor power management is supported.
1112 * Note that we use previously set idle handler will be used on
1113 * platforms that only support C1.
1114 */
1115 if ((pr->flags.power) && (!boot_option_idle_override)) {
1116 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1117 for (i = 1; i <= pr->power.count; i++)
1118 if (pr->power.states[i].valid)
1119 printk(" C%d[C%d]", i,
1120 pr->power.states[i].type);
1121 printk(")\n");
1122
1123 if (pr->id == 0) {
1124 pm_idle_save = pm_idle;
1125 pm_idle = acpi_processor_idle;
1126 }
1127 }
1128
1129 /* 'power' [R] */
1130 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1131 S_IRUGO, acpi_device_dir(device));
1132 if (!entry)
1133 return -EIO;
1134 else {
1135 entry->proc_fops = &acpi_processor_power_fops;
1136 entry->data = acpi_driver_data(device);
1137 entry->owner = THIS_MODULE;
1138 }
1139
1140 pr->flags.power_setup_done = 1;
1141
1142 return 0;
1143 }
1144
1145 int acpi_processor_power_exit(struct acpi_processor *pr,
1146 struct acpi_device *device)
1147 {
1148
1149 pr->flags.power_setup_done = 0;
1150
1151 if (acpi_device_dir(device))
1152 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1153 acpi_device_dir(device));
1154
1155 /* Unregister the idle handler when processor #0 is removed. */
1156 if (pr->id == 0) {
1157 pm_idle = pm_idle_save;
1158
1159 /*
1160 * We are about to unload the current idle thread pm callback
1161 * (pm_idle), Wait for all processors to update cached/local
1162 * copies of pm_idle before proceeding.
1163 */
1164 cpu_idle_wait();
1165 }
1166
1167 return 0;
1168 }
Linux kernel - Deliverables
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