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[IA64-SGI] support for older versions of PROM
[linux-2.6/cjktty.git] / drivers / acpi / processor_idle.c
blob70d8a6ec0920f1589525395a1550360a26cbd54f
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);
58 module_param(max_cstate, uint, 0644);
59
60 static unsigned int nocst = 0;
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 =
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 static struct dmi_system_id __initdata processor_power_dmi_table[] = {
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},
115 {},
116 };
117
118 static inline u32 ticks_elapsed(u32 t1, u32 t2)
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
128 static void
129 acpi_processor_power_activate(struct acpi_processor *pr,
130 struct acpi_processor_cx *new)
131 {
132 struct acpi_processor_cx *old;
133
134 if (!pr || !new)
135 return;
136
137 old = pr->power.state;
138
139 if (old)
140 old->promotion.count = 0;
141 new->demotion.count = 0;
142
143 /* Cleanup from old state. */
144 if (old) {
145 switch (old->type) {
146 case ACPI_STATE_C3:
147 /* Disable bus master reload */
148 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
149 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
150 ACPI_MTX_DO_NOT_LOCK);
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 */
159 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
160 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
161 ACPI_MTX_DO_NOT_LOCK);
162 break;
163 }
164
165 pr->power.state = new;
166
167 return;
168 }
169
170 static void acpi_safe_halt(void)
171 {
172 int polling = test_thread_flag(TIF_POLLING_NRFLAG);
173 if (polling) {
174 clear_thread_flag(TIF_POLLING_NRFLAG);
175 smp_mb__after_clear_bit();
176 }
177 if (!need_resched())
178 safe_halt();
179 if (polling)
180 set_thread_flag(TIF_POLLING_NRFLAG);
181 }
182
183 static atomic_t c3_cpu_count;
184
185 static void acpi_processor_idle(void)
186 {
187 struct acpi_processor *pr = NULL;
188 struct acpi_processor_cx *cx = NULL;
189 struct acpi_processor_cx *next_state = NULL;
190 int sleep_ticks = 0;
191 u32 t1, t2 = 0;
192
193 pr = processors[smp_processor_id()];
194 if (!pr)
195 return;
196
197 /*
198 * Interrupts must be disabled during bus mastering calculations and
199 * for C2/C3 transitions.
200 */
201 local_irq_disable();
202
203 /*
204 * Check whether we truly need to go idle, or should
205 * reschedule:
206 */
207 if (unlikely(need_resched())) {
208 local_irq_enable();
209 return;
210 }
211
212 cx = pr->power.state;
213 if (!cx) {
214 if (pm_idle_save)
215 pm_idle_save();
216 else
217 acpi_safe_halt();
218 return;
219 }
220
221 /*
222 * Check BM Activity
223 * -----------------
224 * Check for bus mastering activity (if required), record, and check
225 * for demotion.
226 */
227 if (pr->flags.bm_check) {
228 u32 bm_status = 0;
229 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
230
231 if (diff > 32)
232 diff = 32;
233
234 while (diff) {
235 /* if we didn't get called, assume there was busmaster activity */
236 diff--;
237 if (diff)
238 pr->power.bm_activity |= 0x1;
239 pr->power.bm_activity <<= 1;
240 }
241
242 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
243 &bm_status, ACPI_MTX_DO_NOT_LOCK);
244 if (bm_status) {
245 pr->power.bm_activity++;
246 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
247 1, ACPI_MTX_DO_NOT_LOCK);
248 }
249 /*
250 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
251 * the true state of bus mastering activity; forcing us to
252 * manually check the BMIDEA bit of each IDE channel.
253 */
254 else if (errata.piix4.bmisx) {
255 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
256 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
257 pr->power.bm_activity++;
258 }
259
260 pr->power.bm_check_timestamp = jiffies;
261
262 /*
263 * Apply bus mastering demotion policy. Automatically demote
264 * to avoid a faulty transition. Note that the processor
265 * won't enter a low-power state during this call (to this
266 * funciton) but should upon the next.
267 *
268 * TBD: A better policy might be to fallback to the demotion
269 * state (use it for this quantum only) istead of
270 * demoting -- and rely on duration as our sole demotion
271 * qualification. This may, however, introduce DMA
272 * issues (e.g. floppy DMA transfer overrun/underrun).
273 */
274 if (pr->power.bm_activity & cx->demotion.threshold.bm) {
275 local_irq_enable();
276 next_state = cx->demotion.state;
277 goto end;
278 }
279 }
280
281 cx->usage++;
282
283 /*
284 * Sleep:
285 * ------
286 * Invoke the current Cx state to put the processor to sleep.
287 */
288 switch (cx->type) {
289
290 case ACPI_STATE_C1:
291 /*
292 * Invoke C1.
293 * Use the appropriate idle routine, the one that would
294 * be used without acpi C-states.
295 */
296 if (pm_idle_save)
297 pm_idle_save();
298 else
299 acpi_safe_halt();
300
301 /*
302 * TBD: Can't get time duration while in C1, as resumes
303 * go to an ISR rather than here. Need to instrument
304 * base interrupt handler.
305 */
306 sleep_ticks = 0xFFFFFFFF;
307 break;
308
309 case ACPI_STATE_C2:
310 /* Get start time (ticks) */
311 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
312 /* Invoke C2 */
313 inb(cx->address);
314 /* Dummy op - must do something useless after P_LVL2 read */
315 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
316 /* Get end time (ticks) */
317 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
318 /* Re-enable interrupts */
319 local_irq_enable();
320 /* Compute time (ticks) that we were actually asleep */
321 sleep_ticks =
322 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
323 break;
324
325 case ACPI_STATE_C3:
326
327 if (pr->flags.bm_check) {
328 if (atomic_inc_return(&c3_cpu_count) ==
329 num_online_cpus()) {
330 /*
331 * All CPUs are trying to go to C3
332 * Disable bus master arbitration
333 */
334 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
335 ACPI_MTX_DO_NOT_LOCK);
336 }
337 } else {
338 /* SMP with no shared cache... Invalidate cache */
339 ACPI_FLUSH_CPU_CACHE();
340 }
341
342 /* Get start time (ticks) */
343 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
344 /* Invoke C3 */
345 inb(cx->address);
346 /* Dummy op - must do something useless after P_LVL3 read */
347 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
348 /* Get end time (ticks) */
349 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
350 if (pr->flags.bm_check) {
351 /* Enable bus master arbitration */
352 atomic_dec(&c3_cpu_count);
353 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
354 ACPI_MTX_DO_NOT_LOCK);
355 }
356
357 /* Re-enable interrupts */
358 local_irq_enable();
359 /* Compute time (ticks) that we were actually asleep */
360 sleep_ticks =
361 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
362 break;
363
364 default:
365 local_irq_enable();
366 return;
367 }
368
369 next_state = pr->power.state;
370
371 /*
372 * Promotion?
373 * ----------
374 * Track the number of longs (time asleep is greater than threshold)
375 * and promote when the count threshold is reached. Note that bus
376 * mastering activity may prevent promotions.
377 * Do not promote above max_cstate.
378 */
379 if (cx->promotion.state &&
380 ((cx->promotion.state - pr->power.states) <= max_cstate)) {
381 if (sleep_ticks > cx->promotion.threshold.ticks) {
382 cx->promotion.count++;
383 cx->demotion.count = 0;
384 if (cx->promotion.count >=
385 cx->promotion.threshold.count) {
386 if (pr->flags.bm_check) {
387 if (!
388 (pr->power.bm_activity & cx->
389 promotion.threshold.bm)) {
390 next_state =
391 cx->promotion.state;
392 goto end;
393 }
394 } else {
395 next_state = cx->promotion.state;
396 goto end;
397 }
398 }
399 }
400 }
401
402 /*
403 * Demotion?
404 * ---------
405 * Track the number of shorts (time asleep is less than time threshold)
406 * and demote when the usage threshold is reached.
407 */
408 if (cx->demotion.state) {
409 if (sleep_ticks < cx->demotion.threshold.ticks) {
410 cx->demotion.count++;
411 cx->promotion.count = 0;
412 if (cx->demotion.count >= cx->demotion.threshold.count) {
413 next_state = cx->demotion.state;
414 goto end;
415 }
416 }
417 }
418
419 end:
420 /*
421 * Demote if current state exceeds max_cstate
422 */
423 if ((pr->power.state - pr->power.states) > max_cstate) {
424 if (cx->demotion.state)
425 next_state = cx->demotion.state;
426 }
427
428 /*
429 * New Cx State?
430 * -------------
431 * If we're going to start using a new Cx state we must clean up
432 * from the previous and prepare to use the new.
433 */
434 if (next_state != pr->power.state)
435 acpi_processor_power_activate(pr, next_state);
436 }
437
438 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
439 {
440 unsigned int i;
441 unsigned int state_is_set = 0;
442 struct acpi_processor_cx *lower = NULL;
443 struct acpi_processor_cx *higher = NULL;
444 struct acpi_processor_cx *cx;
445
446 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
447
448 if (!pr)
449 return_VALUE(-EINVAL);
450
451 /*
452 * This function sets the default Cx state policy (OS idle handler).
453 * Our scheme is to promote quickly to C2 but more conservatively
454 * to C3. We're favoring C2 for its characteristics of low latency
455 * (quick response), good power savings, and ability to allow bus
456 * mastering activity. Note that the Cx state policy is completely
457 * customizable and can be altered dynamically.
458 */
459
460 /* startup state */
461 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
462 cx = &pr->power.states[i];
463 if (!cx->valid)
464 continue;
465
466 if (!state_is_set)
467 pr->power.state = cx;
468 state_is_set++;
469 break;
470 }
471
472 if (!state_is_set)
473 return_VALUE(-ENODEV);
474
475 /* demotion */
476 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
477 cx = &pr->power.states[i];
478 if (!cx->valid)
479 continue;
480
481 if (lower) {
482 cx->demotion.state = lower;
483 cx->demotion.threshold.ticks = cx->latency_ticks;
484 cx->demotion.threshold.count = 1;
485 if (cx->type == ACPI_STATE_C3)
486 cx->demotion.threshold.bm = bm_history;
487 }
488
489 lower = cx;
490 }
491
492 /* promotion */
493 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
494 cx = &pr->power.states[i];
495 if (!cx->valid)
496 continue;
497
498 if (higher) {
499 cx->promotion.state = higher;
500 cx->promotion.threshold.ticks = cx->latency_ticks;
501 if (cx->type >= ACPI_STATE_C2)
502 cx->promotion.threshold.count = 4;
503 else
504 cx->promotion.threshold.count = 10;
505 if (higher->type == ACPI_STATE_C3)
506 cx->promotion.threshold.bm = bm_history;
507 }
508
509 higher = cx;
510 }
511
512 return_VALUE(0);
513 }
514
515 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
516 {
517 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
518
519 if (!pr)
520 return_VALUE(-EINVAL);
521
522 if (!pr->pblk)
523 return_VALUE(-ENODEV);
524
525 memset(pr->power.states, 0, sizeof(pr->power.states));
526
527 /* if info is obtained from pblk/fadt, type equals state */
528 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
529 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
530 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
531
532 /* the C0 state only exists as a filler in our array,
533 * and all processors need to support C1 */
534 pr->power.states[ACPI_STATE_C0].valid = 1;
535 pr->power.states[ACPI_STATE_C1].valid = 1;
536
537 /* determine C2 and C3 address from pblk */
538 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
539 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
540
541 /* determine latencies from FADT */
542 pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
543 pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
544
545 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
546 "lvl2[0x%08x] lvl3[0x%08x]\n",
547 pr->power.states[ACPI_STATE_C2].address,
548 pr->power.states[ACPI_STATE_C3].address));
549
550 return_VALUE(0);
551 }
552
553 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
554 {
555 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
556
557 memset(pr->power.states, 0, sizeof(pr->power.states));
558
559 /* if info is obtained from pblk/fadt, type equals state */
560 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
561 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
562 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
563
564 /* the C0 state only exists as a filler in our array,
565 * and all processors need to support C1 */
566 pr->power.states[ACPI_STATE_C0].valid = 1;
567 pr->power.states[ACPI_STATE_C1].valid = 1;
568
569 return_VALUE(0);
570 }
571
572 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
573 {
574 acpi_status status = 0;
575 acpi_integer count;
576 int i;
577 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
578 union acpi_object *cst;
579
580 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
581
582 if (nocst)
583 return_VALUE(-ENODEV);
584
585 pr->power.count = 0;
586 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
587 memset(&(pr->power.states[i]), 0,
588 sizeof(struct acpi_processor_cx));
589
590 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
591 if (ACPI_FAILURE(status)) {
592 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
593 return_VALUE(-ENODEV);
594 }
595
596 cst = (union acpi_object *)buffer.pointer;
597
598 /* There must be at least 2 elements */
599 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
600 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
601 "not enough elements in _CST\n"));
602 status = -EFAULT;
603 goto end;
604 }
605
606 count = cst->package.elements[0].integer.value;
607
608 /* Validate number of power states. */
609 if (count < 1 || count != cst->package.count - 1) {
610 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
611 "count given by _CST is not valid\n"));
612 status = -EFAULT;
613 goto end;
614 }
615
616 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
617 if (count > ACPI_PROCESSOR_MAX_POWER) {
618 printk(KERN_WARNING
619 "Limiting number of power states to max (%d)\n",
620 ACPI_PROCESSOR_MAX_POWER);
621 printk(KERN_WARNING
622 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
623 count = ACPI_PROCESSOR_MAX_POWER;
624 }
625
626 /* Tell driver that at least _CST is supported. */
627 pr->flags.has_cst = 1;
628
629 for (i = 1; i <= count; i++) {
630 union acpi_object *element;
631 union acpi_object *obj;
632 struct acpi_power_register *reg;
633 struct acpi_processor_cx cx;
634
635 memset(&cx, 0, sizeof(cx));
636
637 element = (union acpi_object *)&(cst->package.elements[i]);
638 if (element->type != ACPI_TYPE_PACKAGE)
639 continue;
640
641 if (element->package.count != 4)
642 continue;
643
644 obj = (union acpi_object *)&(element->package.elements[0]);
645
646 if (obj->type != ACPI_TYPE_BUFFER)
647 continue;
648
649 reg = (struct acpi_power_register *)obj->buffer.pointer;
650
651 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
652 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
653 continue;
654
655 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
656 0 : reg->address;
657
658 /* There should be an easy way to extract an integer... */
659 obj = (union acpi_object *)&(element->package.elements[1]);
660 if (obj->type != ACPI_TYPE_INTEGER)
661 continue;
662
663 cx.type = obj->integer.value;
664
665 if ((cx.type != ACPI_STATE_C1) &&
666 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
667 continue;
668
669 if ((cx.type < ACPI_STATE_C1) || (cx.type > ACPI_STATE_C3))
670 continue;
671
672 obj = (union acpi_object *)&(element->package.elements[2]);
673 if (obj->type != ACPI_TYPE_INTEGER)
674 continue;
675
676 cx.latency = obj->integer.value;
677
678 obj = (union acpi_object *)&(element->package.elements[3]);
679 if (obj->type != ACPI_TYPE_INTEGER)
680 continue;
681
682 cx.power = obj->integer.value;
683
684 (pr->power.count)++;
685 memcpy(&(pr->power.states[pr->power.count]), &cx, sizeof(cx));
686 }
687
688 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
689 pr->power.count));
690
691 /* Validate number of power states discovered */
692 if (pr->power.count < 2)
693 status = -ENODEV;
694
695 end:
696 acpi_os_free(buffer.pointer);
697
698 return_VALUE(status);
699 }
700
701 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
702 {
703 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
704
705 if (!cx->address)
706 return_VOID;
707
708 /*
709 * C2 latency must be less than or equal to 100
710 * microseconds.
711 */
712 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
713 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
714 "latency too large [%d]\n", cx->latency));
715 return_VOID;
716 }
717
718 /*
719 * Otherwise we've met all of our C2 requirements.
720 * Normalize the C2 latency to expidite policy
721 */
722 cx->valid = 1;
723 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
724
725 return_VOID;
726 }
727
728 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
729 struct acpi_processor_cx *cx)
730 {
731 static int bm_check_flag;
732
733 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
734
735 if (!cx->address)
736 return_VOID;
737
738 /*
739 * C3 latency must be less than or equal to 1000
740 * microseconds.
741 */
742 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
743 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
744 "latency too large [%d]\n", cx->latency));
745 return_VOID;
746 }
747
748 /*
749 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
750 * DMA transfers are used by any ISA device to avoid livelock.
751 * Note that we could disable Type-F DMA (as recommended by
752 * the erratum), but this is known to disrupt certain ISA
753 * devices thus we take the conservative approach.
754 */
755 else if (errata.piix4.fdma) {
756 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
757 "C3 not supported on PIIX4 with Type-F DMA\n"));
758 return_VOID;
759 }
760
761 /* All the logic here assumes flags.bm_check is same across all CPUs */
762 if (!bm_check_flag) {
763 /* Determine whether bm_check is needed based on CPU */
764 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
765 bm_check_flag = pr->flags.bm_check;
766 } else {
767 pr->flags.bm_check = bm_check_flag;
768 }
769
770 if (pr->flags.bm_check) {
771 /* bus mastering control is necessary */
772 if (!pr->flags.bm_control) {
773 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
774 "C3 support requires bus mastering control\n"));
775 return_VOID;
776 }
777 } else {
778 /*
779 * WBINVD should be set in fadt, for C3 state to be
780 * supported on when bm_check is not required.
781 */
782 if (acpi_fadt.wb_invd != 1) {
783 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
784 "Cache invalidation should work properly"
785 " for C3 to be enabled on SMP systems\n"));
786 return_VOID;
787 }
788 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
789 0, ACPI_MTX_DO_NOT_LOCK);
790 }
791
792 /*
793 * Otherwise we've met all of our C3 requirements.
794 * Normalize the C3 latency to expidite policy. Enable
795 * checking of bus mastering status (bm_check) so we can
796 * use this in our C3 policy
797 */
798 cx->valid = 1;
799 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
800
801 return_VOID;
802 }
803
804 static int acpi_processor_power_verify(struct acpi_processor *pr)
805 {
806 unsigned int i;
807 unsigned int working = 0;
808
809 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
810 struct acpi_processor_cx *cx = &pr->power.states[i];
811
812 switch (cx->type) {
813 case ACPI_STATE_C1:
814 cx->valid = 1;
815 break;
816
817 case ACPI_STATE_C2:
818 acpi_processor_power_verify_c2(cx);
819 break;
820
821 case ACPI_STATE_C3:
822 acpi_processor_power_verify_c3(pr, cx);
823 break;
824 }
825
826 if (cx->valid)
827 working++;
828 }
829
830 return (working);
831 }
832
833 static int acpi_processor_get_power_info(struct acpi_processor *pr)
834 {
835 unsigned int i;
836 int result;
837
838 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
839
840 /* NOTE: the idle thread may not be running while calling
841 * this function */
842
843 result = acpi_processor_get_power_info_cst(pr);
844 if ((result) || (acpi_processor_power_verify(pr) < 2)) {
845 result = acpi_processor_get_power_info_fadt(pr);
846 if ((result) || (acpi_processor_power_verify(pr) < 2))
847 result = acpi_processor_get_power_info_default_c1(pr);
848 }
849
850 /*
851 * Set Default Policy
852 * ------------------
853 * Now that we know which states are supported, set the default
854 * policy. Note that this policy can be changed dynamically
855 * (e.g. encourage deeper sleeps to conserve battery life when
856 * not on AC).
857 */
858 result = acpi_processor_set_power_policy(pr);
859 if (result)
860 return_VALUE(result);
861
862 /*
863 * if one state of type C2 or C3 is available, mark this
864 * CPU as being "idle manageable"
865 */
866 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
867 if (pr->power.states[i].valid) {
868 pr->power.count = i;
869 if (pr->power.states[i].type >= ACPI_STATE_C2)
870 pr->flags.power = 1;
871 }
872 }
873
874 return_VALUE(0);
875 }
876
877 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
878 {
879 int result = 0;
880
881 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
882
883 if (!pr)
884 return_VALUE(-EINVAL);
885
886 if (nocst) {
887 return_VALUE(-ENODEV);
888 }
889
890 if (!pr->flags.power_setup_done)
891 return_VALUE(-ENODEV);
892
893 /* Fall back to the default idle loop */
894 pm_idle = pm_idle_save;
895 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
896
897 pr->flags.power = 0;
898 result = acpi_processor_get_power_info(pr);
899 if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
900 pm_idle = acpi_processor_idle;
901
902 return_VALUE(result);
903 }
904
905 /* proc interface */
906
907 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
908 {
909 struct acpi_processor *pr = (struct acpi_processor *)seq->private;
910 unsigned int i;
911
912 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
913
914 if (!pr)
915 goto end;
916
917 seq_printf(seq, "active state: C%zd\n"
918 "max_cstate: C%d\n"
919 "bus master activity: %08x\n",
920 pr->power.state ? pr->power.state - pr->power.states : 0,
921 max_cstate, (unsigned)pr->power.bm_activity);
922
923 seq_puts(seq, "states:\n");
924
925 for (i = 1; i <= pr->power.count; i++) {
926 seq_printf(seq, " %cC%d: ",
927 (&pr->power.states[i] ==
928 pr->power.state ? '*' : ' '), i);
929
930 if (!pr->power.states[i].valid) {
931 seq_puts(seq, "<not supported>\n");
932 continue;
933 }
934
935 switch (pr->power.states[i].type) {
936 case ACPI_STATE_C1:
937 seq_printf(seq, "type[C1] ");
938 break;
939 case ACPI_STATE_C2:
940 seq_printf(seq, "type[C2] ");
941 break;
942 case ACPI_STATE_C3:
943 seq_printf(seq, "type[C3] ");
944 break;
945 default:
946 seq_printf(seq, "type[--] ");
947 break;
948 }
949
950 if (pr->power.states[i].promotion.state)
951 seq_printf(seq, "promotion[C%zd] ",
952 (pr->power.states[i].promotion.state -
953 pr->power.states));
954 else
955 seq_puts(seq, "promotion[--] ");
956
957 if (pr->power.states[i].demotion.state)
958 seq_printf(seq, "demotion[C%zd] ",
959 (pr->power.states[i].demotion.state -
960 pr->power.states));
961 else
962 seq_puts(seq, "demotion[--] ");
963
964 seq_printf(seq, "latency[%03d] usage[%08d]\n",
965 pr->power.states[i].latency,
966 pr->power.states[i].usage);
967 }
968
969 end:
970 return_VALUE(0);
971 }
972
973 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
974 {
975 return single_open(file, acpi_processor_power_seq_show,
976 PDE(inode)->data);
977 }
978
979 static struct file_operations acpi_processor_power_fops = {
980 .open = acpi_processor_power_open_fs,
981 .read = seq_read,
982 .llseek = seq_lseek,
983 .release = single_release,
984 };
985
986 int acpi_processor_power_init(struct acpi_processor *pr,
987 struct acpi_device *device)
988 {
989 acpi_status status = 0;
990 static int first_run = 0;
991 struct proc_dir_entry *entry = NULL;
992 unsigned int i;
993
994 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
995
996 if (!first_run) {
997 dmi_check_system(processor_power_dmi_table);
998 if (max_cstate < ACPI_C_STATES_MAX)
999 printk(KERN_NOTICE
1000 "ACPI: processor limited to max C-state %d\n",
1001 max_cstate);
1002 first_run++;
1003 }
1004
1005 if (!pr)
1006 return_VALUE(-EINVAL);
1007
1008 if (acpi_fadt.cst_cnt && !nocst) {
1009 status =
1010 acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1011 if (ACPI_FAILURE(status)) {
1012 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1013 "Notifying BIOS of _CST ability failed\n"));
1014 }
1015 }
1016
1017 acpi_processor_power_init_pdc(&(pr->power), pr->id);
1018 acpi_processor_set_pdc(pr, pr->power.pdc);
1019 acpi_processor_get_power_info(pr);
1020
1021 /*
1022 * Install the idle handler if processor power management is supported.
1023 * Note that we use previously set idle handler will be used on
1024 * platforms that only support C1.
1025 */
1026 if ((pr->flags.power) && (!boot_option_idle_override)) {
1027 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1028 for (i = 1; i <= pr->power.count; i++)
1029 if (pr->power.states[i].valid)
1030 printk(" C%d[C%d]", i,
1031 pr->power.states[i].type);
1032 printk(")\n");
1033
1034 if (pr->id == 0) {
1035 pm_idle_save = pm_idle;
1036 pm_idle = acpi_processor_idle;
1037 }
1038 }
1039
1040 /* 'power' [R] */
1041 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1042 S_IRUGO, acpi_device_dir(device));
1043 if (!entry)
1044 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1045 "Unable to create '%s' fs entry\n",
1046 ACPI_PROCESSOR_FILE_POWER));
1047 else {
1048 entry->proc_fops = &acpi_processor_power_fops;
1049 entry->data = acpi_driver_data(device);
1050 entry->owner = THIS_MODULE;
1051 }
1052
1053 pr->flags.power_setup_done = 1;
1054
1055 return_VALUE(0);
1056 }
1057
1058 int acpi_processor_power_exit(struct acpi_processor *pr,
1059 struct acpi_device *device)
1060 {
1061 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1062
1063 pr->flags.power_setup_done = 0;
1064
1065 if (acpi_device_dir(device))
1066 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1067 acpi_device_dir(device));
1068
1069 /* Unregister the idle handler when processor #0 is removed. */
1070 if (pr->id == 0) {
1071 pm_idle = pm_idle_save;
1072
1073 /*
1074 * We are about to unload the current idle thread pm callback
1075 * (pm_idle), Wait for all processors to update cached/local
1076 * copies of pm_idle before proceeding.
1077 */
1078 cpu_idle_wait();
1079 }
1080
1081 return_VALUE(0);
1082 }
CJK support for tty framebuffer vt