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[PATCH] lib/string.c cleanup: remove pointless register keyword
[linux-2.6/openmoko-kernel/knife-kernel.git] / drivers / acpi / processor_idle.c
blob26a3a4016115364467b5feff71415c7e88f4d016
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
41 #include <asm/io.h>
42 #include <asm/uaccess.h>
43
44 #include <acpi/acpi_bus.h>
45 #include <acpi/processor.h>
46
47 #define ACPI_PROCESSOR_COMPONENT 0x01000000
48 #define ACPI_PROCESSOR_CLASS "processor"
49 #define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
50 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
51 ACPI_MODULE_NAME("acpi_processor")
52 #define ACPI_PROCESSOR_FILE_POWER "power"
53 #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
54 #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
55 #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
56 static void (*pm_idle_save) (void);
57 module_param(max_cstate, uint, 0644);
58
59 static unsigned int nocst = 0;
60 module_param(nocst, uint, 0000);
61
62 /*
63 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
64 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
65 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
66 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
67 * reduce history for more aggressive entry into C3
68 */
69 static unsigned int bm_history =
70 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
71 module_param(bm_history, uint, 0644);
72 /* --------------------------------------------------------------------------
73 Power Management
74 -------------------------------------------------------------------------- */
75
76 /*
77 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
78 * For now disable this. Probably a bug somewhere else.
79 *
80 * To skip this limit, boot/load with a large max_cstate limit.
81 */
82 static int set_max_cstate(struct dmi_system_id *id)
83 {
84 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
85 return 0;
86
87 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
88 " Override with \"processor.max_cstate=%d\"\n", id->ident,
89 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
90
91 max_cstate = (long)id->driver_data;
92
93 return 0;
94 }
95
96 static struct dmi_system_id __initdata processor_power_dmi_table[] = {
97 {set_max_cstate, "IBM ThinkPad R40e", {
98 DMI_MATCH(DMI_BIOS_VENDOR,
99 "IBM"),
100 DMI_MATCH(DMI_BIOS_VERSION,
101 "1SET60WW")},
102 (void *)1},
103 {set_max_cstate, "Medion 41700", {
104 DMI_MATCH(DMI_BIOS_VENDOR,
105 "Phoenix Technologies LTD"),
106 DMI_MATCH(DMI_BIOS_VERSION,
107 "R01-A1J")}, (void *)1},
108 {set_max_cstate, "Clevo 5600D", {
109 DMI_MATCH(DMI_BIOS_VENDOR,
110 "Phoenix Technologies LTD"),
111 DMI_MATCH(DMI_BIOS_VERSION,
112 "SHE845M0.86C.0013.D.0302131307")},
113 (void *)2},
114 {},
115 };
116
117 static inline u32 ticks_elapsed(u32 t1, u32 t2)
118 {
119 if (t2 >= t1)
120 return (t2 - t1);
121 else if (!acpi_fadt.tmr_val_ext)
122 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
123 else
124 return ((0xFFFFFFFF - t1) + t2);
125 }
126
127 static void
128 acpi_processor_power_activate(struct acpi_processor *pr,
129 struct acpi_processor_cx *new)
130 {
131 struct acpi_processor_cx *old;
132
133 if (!pr || !new)
134 return;
135
136 old = pr->power.state;
137
138 if (old)
139 old->promotion.count = 0;
140 new->demotion.count = 0;
141
142 /* Cleanup from old state. */
143 if (old) {
144 switch (old->type) {
145 case ACPI_STATE_C3:
146 /* Disable bus master reload */
147 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
148 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
149 ACPI_MTX_DO_NOT_LOCK);
150 break;
151 }
152 }
153
154 /* Prepare to use new state. */
155 switch (new->type) {
156 case ACPI_STATE_C3:
157 /* Enable bus master reload */
158 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
159 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
160 ACPI_MTX_DO_NOT_LOCK);
161 break;
162 }
163
164 pr->power.state = new;
165
166 return;
167 }
168
169 static atomic_t c3_cpu_count;
170
171 static void acpi_processor_idle(void)
172 {
173 struct acpi_processor *pr = NULL;
174 struct acpi_processor_cx *cx = NULL;
175 struct acpi_processor_cx *next_state = NULL;
176 int sleep_ticks = 0;
177 u32 t1, t2 = 0;
178
179 pr = processors[raw_smp_processor_id()];
180 if (!pr)
181 return;
182
183 /*
184 * Interrupts must be disabled during bus mastering calculations and
185 * for C2/C3 transitions.
186 */
187 local_irq_disable();
188
189 /*
190 * Check whether we truly need to go idle, or should
191 * reschedule:
192 */
193 if (unlikely(need_resched())) {
194 local_irq_enable();
195 return;
196 }
197
198 cx = pr->power.state;
199 if (!cx)
200 goto easy_out;
201
202 /*
203 * Check BM Activity
204 * -----------------
205 * Check for bus mastering activity (if required), record, and check
206 * for demotion.
207 */
208 if (pr->flags.bm_check) {
209 u32 bm_status = 0;
210 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
211
212 if (diff > 32)
213 diff = 32;
214
215 while (diff) {
216 /* if we didn't get called, assume there was busmaster activity */
217 diff--;
218 if (diff)
219 pr->power.bm_activity |= 0x1;
220 pr->power.bm_activity <<= 1;
221 }
222
223 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
224 &bm_status, ACPI_MTX_DO_NOT_LOCK);
225 if (bm_status) {
226 pr->power.bm_activity++;
227 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
228 1, ACPI_MTX_DO_NOT_LOCK);
229 }
230 /*
231 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
232 * the true state of bus mastering activity; forcing us to
233 * manually check the BMIDEA bit of each IDE channel.
234 */
235 else if (errata.piix4.bmisx) {
236 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
237 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
238 pr->power.bm_activity++;
239 }
240
241 pr->power.bm_check_timestamp = jiffies;
242
243 /*
244 * Apply bus mastering demotion policy. Automatically demote
245 * to avoid a faulty transition. Note that the processor
246 * won't enter a low-power state during this call (to this
247 * funciton) but should upon the next.
248 *
249 * TBD: A better policy might be to fallback to the demotion
250 * state (use it for this quantum only) istead of
251 * demoting -- and rely on duration as our sole demotion
252 * qualification. This may, however, introduce DMA
253 * issues (e.g. floppy DMA transfer overrun/underrun).
254 */
255 if (pr->power.bm_activity & cx->demotion.threshold.bm) {
256 local_irq_enable();
257 next_state = cx->demotion.state;
258 goto end;
259 }
260 }
261
262 cx->usage++;
263
264 /*
265 * Sleep:
266 * ------
267 * Invoke the current Cx state to put the processor to sleep.
268 */
269 switch (cx->type) {
270
271 case ACPI_STATE_C1:
272 /*
273 * Invoke C1.
274 * Use the appropriate idle routine, the one that would
275 * be used without acpi C-states.
276 */
277 if (pm_idle_save)
278 pm_idle_save();
279 else
280 safe_halt();
281 /*
282 * TBD: Can't get time duration while in C1, as resumes
283 * go to an ISR rather than here. Need to instrument
284 * base interrupt handler.
285 */
286 sleep_ticks = 0xFFFFFFFF;
287 break;
288
289 case ACPI_STATE_C2:
290 /* Get start time (ticks) */
291 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
292 /* Invoke C2 */
293 inb(cx->address);
294 /* Dummy op - must do something useless after P_LVL2 read */
295 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
296 /* Get end time (ticks) */
297 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
298 /* Re-enable interrupts */
299 local_irq_enable();
300 /* Compute time (ticks) that we were actually asleep */
301 sleep_ticks =
302 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
303 break;
304
305 case ACPI_STATE_C3:
306
307 if (pr->flags.bm_check) {
308 if (atomic_inc_return(&c3_cpu_count) ==
309 num_online_cpus()) {
310 /*
311 * All CPUs are trying to go to C3
312 * Disable bus master arbitration
313 */
314 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
315 ACPI_MTX_DO_NOT_LOCK);
316 }
317 } else {
318 /* SMP with no shared cache... Invalidate cache */
319 ACPI_FLUSH_CPU_CACHE();
320 }
321
322 /* Get start time (ticks) */
323 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
324 /* Invoke C3 */
325 inb(cx->address);
326 /* Dummy op - must do something useless after P_LVL3 read */
327 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
328 /* Get end time (ticks) */
329 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
330 if (pr->flags.bm_check) {
331 /* Enable bus master arbitration */
332 atomic_dec(&c3_cpu_count);
333 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
334 ACPI_MTX_DO_NOT_LOCK);
335 }
336
337 /* Re-enable interrupts */
338 local_irq_enable();
339 /* Compute time (ticks) that we were actually asleep */
340 sleep_ticks =
341 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
342 break;
343
344 default:
345 local_irq_enable();
346 return;
347 }
348
349 next_state = pr->power.state;
350
351 /*
352 * Promotion?
353 * ----------
354 * Track the number of longs (time asleep is greater than threshold)
355 * and promote when the count threshold is reached. Note that bus
356 * mastering activity may prevent promotions.
357 * Do not promote above max_cstate.
358 */
359 if (cx->promotion.state &&
360 ((cx->promotion.state - pr->power.states) <= max_cstate)) {
361 if (sleep_ticks > cx->promotion.threshold.ticks) {
362 cx->promotion.count++;
363 cx->demotion.count = 0;
364 if (cx->promotion.count >=
365 cx->promotion.threshold.count) {
366 if (pr->flags.bm_check) {
367 if (!
368 (pr->power.bm_activity & cx->
369 promotion.threshold.bm)) {
370 next_state =
371 cx->promotion.state;
372 goto end;
373 }
374 } else {
375 next_state = cx->promotion.state;
376 goto end;
377 }
378 }
379 }
380 }
381
382 /*
383 * Demotion?
384 * ---------
385 * Track the number of shorts (time asleep is less than time threshold)
386 * and demote when the usage threshold is reached.
387 */
388 if (cx->demotion.state) {
389 if (sleep_ticks < cx->demotion.threshold.ticks) {
390 cx->demotion.count++;
391 cx->promotion.count = 0;
392 if (cx->demotion.count >= cx->demotion.threshold.count) {
393 next_state = cx->demotion.state;
394 goto end;
395 }
396 }
397 }
398
399 end:
400 /*
401 * Demote if current state exceeds max_cstate
402 */
403 if ((pr->power.state - pr->power.states) > max_cstate) {
404 if (cx->demotion.state)
405 next_state = cx->demotion.state;
406 }
407
408 /*
409 * New Cx State?
410 * -------------
411 * If we're going to start using a new Cx state we must clean up
412 * from the previous and prepare to use the new.
413 */
414 if (next_state != pr->power.state)
415 acpi_processor_power_activate(pr, next_state);
416
417 return;
418
419 easy_out:
420 /* do C1 instead of busy loop */
421 if (pm_idle_save)
422 pm_idle_save();
423 else
424 safe_halt();
425 return;
426 }
427
428 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
429 {
430 unsigned int i;
431 unsigned int state_is_set = 0;
432 struct acpi_processor_cx *lower = NULL;
433 struct acpi_processor_cx *higher = NULL;
434 struct acpi_processor_cx *cx;
435
436 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
437
438 if (!pr)
439 return_VALUE(-EINVAL);
440
441 /*
442 * This function sets the default Cx state policy (OS idle handler).
443 * Our scheme is to promote quickly to C2 but more conservatively
444 * to C3. We're favoring C2 for its characteristics of low latency
445 * (quick response), good power savings, and ability to allow bus
446 * mastering activity. Note that the Cx state policy is completely
447 * customizable and can be altered dynamically.
448 */
449
450 /* startup state */
451 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
452 cx = &pr->power.states[i];
453 if (!cx->valid)
454 continue;
455
456 if (!state_is_set)
457 pr->power.state = cx;
458 state_is_set++;
459 break;
460 }
461
462 if (!state_is_set)
463 return_VALUE(-ENODEV);
464
465 /* demotion */
466 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
467 cx = &pr->power.states[i];
468 if (!cx->valid)
469 continue;
470
471 if (lower) {
472 cx->demotion.state = lower;
473 cx->demotion.threshold.ticks = cx->latency_ticks;
474 cx->demotion.threshold.count = 1;
475 if (cx->type == ACPI_STATE_C3)
476 cx->demotion.threshold.bm = bm_history;
477 }
478
479 lower = cx;
480 }
481
482 /* promotion */
483 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
484 cx = &pr->power.states[i];
485 if (!cx->valid)
486 continue;
487
488 if (higher) {
489 cx->promotion.state = higher;
490 cx->promotion.threshold.ticks = cx->latency_ticks;
491 if (cx->type >= ACPI_STATE_C2)
492 cx->promotion.threshold.count = 4;
493 else
494 cx->promotion.threshold.count = 10;
495 if (higher->type == ACPI_STATE_C3)
496 cx->promotion.threshold.bm = bm_history;
497 }
498
499 higher = cx;
500 }
501
502 return_VALUE(0);
503 }
504
505 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
506 {
507 int i;
508
509 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
510
511 if (!pr)
512 return_VALUE(-EINVAL);
513
514 if (!pr->pblk)
515 return_VALUE(-ENODEV);
516
517 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
518 memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
519
520 /* if info is obtained from pblk/fadt, type equals state */
521 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
522 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
523 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
524
525 /* the C0 state only exists as a filler in our array,
526 * and all processors need to support C1 */
527 pr->power.states[ACPI_STATE_C0].valid = 1;
528 pr->power.states[ACPI_STATE_C1].valid = 1;
529
530 /* determine C2 and C3 address from pblk */
531 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
532 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
533
534 /* determine latencies from FADT */
535 pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
536 pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
537
538 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
539 "lvl2[0x%08x] lvl3[0x%08x]\n",
540 pr->power.states[ACPI_STATE_C2].address,
541 pr->power.states[ACPI_STATE_C3].address));
542
543 return_VALUE(0);
544 }
545
546 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
547 {
548 int i;
549
550 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
551
552 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
553 memset(&(pr->power.states[i]), 0,
554 sizeof(struct acpi_processor_cx));
555
556 /* if info is obtained from pblk/fadt, type equals state */
557 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
558 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
559 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
560
561 /* the C0 state only exists as a filler in our array,
562 * and all processors need to support C1 */
563 pr->power.states[ACPI_STATE_C0].valid = 1;
564 pr->power.states[ACPI_STATE_C1].valid = 1;
565
566 return_VALUE(0);
567 }
568
569 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
570 {
571 acpi_status status = 0;
572 acpi_integer count;
573 int i;
574 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
575 union acpi_object *cst;
576
577 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
578
579 if (nocst)
580 return_VALUE(-ENODEV);
581
582 pr->power.count = 0;
583 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
584 memset(&(pr->power.states[i]), 0,
585 sizeof(struct acpi_processor_cx));
586
587 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
588 if (ACPI_FAILURE(status)) {
589 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
590 return_VALUE(-ENODEV);
591 }
592
593 cst = (union acpi_object *)buffer.pointer;
594
595 /* There must be at least 2 elements */
596 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
597 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
598 "not enough elements in _CST\n"));
599 status = -EFAULT;
600 goto end;
601 }
602
603 count = cst->package.elements[0].integer.value;
604
605 /* Validate number of power states. */
606 if (count < 1 || count != cst->package.count - 1) {
607 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
608 "count given by _CST is not valid\n"));
609 status = -EFAULT;
610 goto end;
611 }
612
613 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
614 if (count > ACPI_PROCESSOR_MAX_POWER) {
615 printk(KERN_WARNING
616 "Limiting number of power states to max (%d)\n",
617 ACPI_PROCESSOR_MAX_POWER);
618 printk(KERN_WARNING
619 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
620 count = ACPI_PROCESSOR_MAX_POWER;
621 }
622
623 /* Tell driver that at least _CST is supported. */
624 pr->flags.has_cst = 1;
625
626 for (i = 1; i <= count; i++) {
627 union acpi_object *element;
628 union acpi_object *obj;
629 struct acpi_power_register *reg;
630 struct acpi_processor_cx cx;
631
632 memset(&cx, 0, sizeof(cx));
633
634 element = (union acpi_object *)&(cst->package.elements[i]);
635 if (element->type != ACPI_TYPE_PACKAGE)
636 continue;
637
638 if (element->package.count != 4)
639 continue;
640
641 obj = (union acpi_object *)&(element->package.elements[0]);
642
643 if (obj->type != ACPI_TYPE_BUFFER)
644 continue;
645
646 reg = (struct acpi_power_register *)obj->buffer.pointer;
647
648 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
649 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
650 continue;
651
652 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
653 0 : reg->address;
654
655 /* There should be an easy way to extract an integer... */
656 obj = (union acpi_object *)&(element->package.elements[1]);
657 if (obj->type != ACPI_TYPE_INTEGER)
658 continue;
659
660 cx.type = obj->integer.value;
661
662 if ((cx.type != ACPI_STATE_C1) &&
663 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
664 continue;
665
666 if ((cx.type < ACPI_STATE_C1) || (cx.type > ACPI_STATE_C3))
667 continue;
668
669 obj = (union acpi_object *)&(element->package.elements[2]);
670 if (obj->type != ACPI_TYPE_INTEGER)
671 continue;
672
673 cx.latency = obj->integer.value;
674
675 obj = (union acpi_object *)&(element->package.elements[3]);
676 if (obj->type != ACPI_TYPE_INTEGER)
677 continue;
678
679 cx.power = obj->integer.value;
680
681 (pr->power.count)++;
682 memcpy(&(pr->power.states[pr->power.count]), &cx, sizeof(cx));
683 }
684
685 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
686 pr->power.count));
687
688 /* Validate number of power states discovered */
689 if (pr->power.count < 2)
690 status = -ENODEV;
691
692 end:
693 acpi_os_free(buffer.pointer);
694
695 return_VALUE(status);
696 }
697
698 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
699 {
700 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
701
702 if (!cx->address)
703 return_VOID;
704
705 /*
706 * C2 latency must be less than or equal to 100
707 * microseconds.
708 */
709 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
710 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
711 "latency too large [%d]\n", cx->latency));
712 return_VOID;
713 }
714
715 /*
716 * Otherwise we've met all of our C2 requirements.
717 * Normalize the C2 latency to expidite policy
718 */
719 cx->valid = 1;
720 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
721
722 return_VOID;
723 }
724
725 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
726 struct acpi_processor_cx *cx)
727 {
728 static int bm_check_flag;
729
730 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
731
732 if (!cx->address)
733 return_VOID;
734
735 /*
736 * C3 latency must be less than or equal to 1000
737 * microseconds.
738 */
739 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
740 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
741 "latency too large [%d]\n", cx->latency));
742 return_VOID;
743 }
744
745 /*
746 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
747 * DMA transfers are used by any ISA device to avoid livelock.
748 * Note that we could disable Type-F DMA (as recommended by
749 * the erratum), but this is known to disrupt certain ISA
750 * devices thus we take the conservative approach.
751 */
752 else if (errata.piix4.fdma) {
753 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
754 "C3 not supported on PIIX4 with Type-F DMA\n"));
755 return_VOID;
756 }
757
758 /* All the logic here assumes flags.bm_check is same across all CPUs */
759 if (!bm_check_flag) {
760 /* Determine whether bm_check is needed based on CPU */
761 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
762 bm_check_flag = pr->flags.bm_check;
763 } else {
764 pr->flags.bm_check = bm_check_flag;
765 }
766
767 if (pr->flags.bm_check) {
768 /* bus mastering control is necessary */
769 if (!pr->flags.bm_control) {
770 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
771 "C3 support requires bus mastering control\n"));
772 return_VOID;
773 }
774 } else {
775 /*
776 * WBINVD should be set in fadt, for C3 state to be
777 * supported on when bm_check is not required.
778 */
779 if (acpi_fadt.wb_invd != 1) {
780 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
781 "Cache invalidation should work properly"
782 " for C3 to be enabled on SMP systems\n"));
783 return_VOID;
784 }
785 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
786 0, ACPI_MTX_DO_NOT_LOCK);
787 }
788
789 /*
790 * Otherwise we've met all of our C3 requirements.
791 * Normalize the C3 latency to expidite policy. Enable
792 * checking of bus mastering status (bm_check) so we can
793 * use this in our C3 policy
794 */
795 cx->valid = 1;
796 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
797
798 return_VOID;
799 }
800
801 static int acpi_processor_power_verify(struct acpi_processor *pr)
802 {
803 unsigned int i;
804 unsigned int working = 0;
805
806 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
807 struct acpi_processor_cx *cx = &pr->power.states[i];
808
809 switch (cx->type) {
810 case ACPI_STATE_C1:
811 cx->valid = 1;
812 break;
813
814 case ACPI_STATE_C2:
815 acpi_processor_power_verify_c2(cx);
816 break;
817
818 case ACPI_STATE_C3:
819 acpi_processor_power_verify_c3(pr, cx);
820 break;
821 }
822
823 if (cx->valid)
824 working++;
825 }
826
827 return (working);
828 }
829
830 static int acpi_processor_get_power_info(struct acpi_processor *pr)
831 {
832 unsigned int i;
833 int result;
834
835 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
836
837 /* NOTE: the idle thread may not be running while calling
838 * this function */
839
840 result = acpi_processor_get_power_info_cst(pr);
841 if ((result) || (acpi_processor_power_verify(pr) < 2)) {
842 result = acpi_processor_get_power_info_fadt(pr);
843 if ((result) || (acpi_processor_power_verify(pr) < 2))
844 result = acpi_processor_get_power_info_default_c1(pr);
845 }
846
847 /*
848 * Set Default Policy
849 * ------------------
850 * Now that we know which states are supported, set the default
851 * policy. Note that this policy can be changed dynamically
852 * (e.g. encourage deeper sleeps to conserve battery life when
853 * not on AC).
854 */
855 result = acpi_processor_set_power_policy(pr);
856 if (result)
857 return_VALUE(result);
858
859 /*
860 * if one state of type C2 or C3 is available, mark this
861 * CPU as being "idle manageable"
862 */
863 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
864 if (pr->power.states[i].valid) {
865 pr->power.count = i;
866 pr->flags.power = 1;
867 }
868 }
869
870 return_VALUE(0);
871 }
872
873 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
874 {
875 int result = 0;
876
877 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
878
879 if (!pr)
880 return_VALUE(-EINVAL);
881
882 if (nocst) {
883 return_VALUE(-ENODEV);
884 }
885
886 if (!pr->flags.power_setup_done)
887 return_VALUE(-ENODEV);
888
889 /* Fall back to the default idle loop */
890 pm_idle = pm_idle_save;
891 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
892
893 pr->flags.power = 0;
894 result = acpi_processor_get_power_info(pr);
895 if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
896 pm_idle = acpi_processor_idle;
897
898 return_VALUE(result);
899 }
900
901 /* proc interface */
902
903 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
904 {
905 struct acpi_processor *pr = (struct acpi_processor *)seq->private;
906 unsigned int i;
907
908 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
909
910 if (!pr)
911 goto end;
912
913 seq_printf(seq, "active state: C%zd\n"
914 "max_cstate: C%d\n"
915 "bus master activity: %08x\n",
916 pr->power.state ? pr->power.state - pr->power.states : 0,
917 max_cstate, (unsigned)pr->power.bm_activity);
918
919 seq_puts(seq, "states:\n");
920
921 for (i = 1; i <= pr->power.count; i++) {
922 seq_printf(seq, " %cC%d: ",
923 (&pr->power.states[i] ==
924 pr->power.state ? '*' : ' '), i);
925
926 if (!pr->power.states[i].valid) {
927 seq_puts(seq, "<not supported>\n");
928 continue;
929 }
930
931 switch (pr->power.states[i].type) {
932 case ACPI_STATE_C1:
933 seq_printf(seq, "type[C1] ");
934 break;
935 case ACPI_STATE_C2:
936 seq_printf(seq, "type[C2] ");
937 break;
938 case ACPI_STATE_C3:
939 seq_printf(seq, "type[C3] ");
940 break;
941 default:
942 seq_printf(seq, "type[--] ");
943 break;
944 }
945
946 if (pr->power.states[i].promotion.state)
947 seq_printf(seq, "promotion[C%zd] ",
948 (pr->power.states[i].promotion.state -
949 pr->power.states));
950 else
951 seq_puts(seq, "promotion[--] ");
952
953 if (pr->power.states[i].demotion.state)
954 seq_printf(seq, "demotion[C%zd] ",
955 (pr->power.states[i].demotion.state -
956 pr->power.states));
957 else
958 seq_puts(seq, "demotion[--] ");
959
960 seq_printf(seq, "latency[%03d] usage[%08d]\n",
961 pr->power.states[i].latency,
962 pr->power.states[i].usage);
963 }
964
965 end:
966 return_VALUE(0);
967 }
968
969 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
970 {
971 return single_open(file, acpi_processor_power_seq_show,
972 PDE(inode)->data);
973 }
974
975 static struct file_operations acpi_processor_power_fops = {
976 .open = acpi_processor_power_open_fs,
977 .read = seq_read,
978 .llseek = seq_lseek,
979 .release = single_release,
980 };
981
982 int acpi_processor_power_init(struct acpi_processor *pr,
983 struct acpi_device *device)
984 {
985 acpi_status status = 0;
986 static int first_run = 0;
987 struct proc_dir_entry *entry = NULL;
988 unsigned int i;
989
990 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
991
992 if (!first_run) {
993 dmi_check_system(processor_power_dmi_table);
994 if (max_cstate < ACPI_C_STATES_MAX)
995 printk(KERN_NOTICE
996 "ACPI: processor limited to max C-state %d\n",
997 max_cstate);
998 first_run++;
999 }
1000
1001 if (!pr)
1002 return_VALUE(-EINVAL);
1003
1004 if (acpi_fadt.cst_cnt && !nocst) {
1005 status =
1006 acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1007 if (ACPI_FAILURE(status)) {
1008 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1009 "Notifying BIOS of _CST ability failed\n"));
1010 }
1011 }
1012
1013 acpi_processor_power_init_pdc(&(pr->power), pr->id);
1014 acpi_processor_set_pdc(pr, pr->power.pdc);
1015 acpi_processor_get_power_info(pr);
1016
1017 /*
1018 * Install the idle handler if processor power management is supported.
1019 * Note that we use previously set idle handler will be used on
1020 * platforms that only support C1.
1021 */
1022 if ((pr->flags.power) && (!boot_option_idle_override)) {
1023 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1024 for (i = 1; i <= pr->power.count; i++)
1025 if (pr->power.states[i].valid)
1026 printk(" C%d[C%d]", i,
1027 pr->power.states[i].type);
1028 printk(")\n");
1029
1030 if (pr->id == 0) {
1031 pm_idle_save = pm_idle;
1032 pm_idle = acpi_processor_idle;
1033 }
1034 }
1035
1036 /* 'power' [R] */
1037 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1038 S_IRUGO, acpi_device_dir(device));
1039 if (!entry)
1040 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1041 "Unable to create '%s' fs entry\n",
1042 ACPI_PROCESSOR_FILE_POWER));
1043 else {
1044 entry->proc_fops = &acpi_processor_power_fops;
1045 entry->data = acpi_driver_data(device);
1046 entry->owner = THIS_MODULE;
1047 }
1048
1049 pr->flags.power_setup_done = 1;
1050
1051 return_VALUE(0);
1052 }
1053
1054 int acpi_processor_power_exit(struct acpi_processor *pr,
1055 struct acpi_device *device)
1056 {
1057 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1058
1059 pr->flags.power_setup_done = 0;
1060
1061 if (acpi_device_dir(device))
1062 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1063 acpi_device_dir(device));
1064
1065 /* Unregister the idle handler when processor #0 is removed. */
1066 if (pr->id == 0) {
1067 pm_idle = pm_idle_save;
1068
1069 /*
1070 * We are about to unload the current idle thread pm callback
1071 * (pm_idle), Wait for all processors to update cached/local
1072 * copies of pm_idle before proceeding.
1073 */
1074 cpu_idle_wait();
1075 }
1076
1077 return_VALUE(0);
1078 }
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