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Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / acpi / processor_idle.c
CommitLineData
1da177e4
LT		 1/*
2 * processor_idle - idle state submodule to the ACPI processor driver
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
02df8b93
VP		 9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
1da177e4
LT		 11 *
12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License along
25 * with this program; if not, write to the Free Software Foundation, Inc.,
26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27 *
28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29 */
30
31#include <linux/kernel.h>
32#include <linux/module.h>
33#include <linux/init.h>
34#include <linux/cpufreq.h>
35#include <linux/proc_fs.h>
36#include <linux/seq_file.h>
37#include <linux/acpi.h>
38#include <linux/dmi.h>
39#include <linux/moduleparam.h>
4e57b681 40#include <linux/sched.h> /* need_resched() */
1da177e4
LT		 41
42#include <asm/io.h>
43#include <asm/uaccess.h>
44
45#include <acpi/acpi_bus.h>
46#include <acpi/processor.h>
47
48#define ACPI_PROCESSOR_COMPONENT 0x01000000
49#define ACPI_PROCESSOR_CLASS "processor"
50#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
51#define _COMPONENT ACPI_PROCESSOR_COMPONENT
4be44fcd 52ACPI_MODULE_NAME("acpi_processor")
1da177e4 53#define ACPI_PROCESSOR_FILE_POWER "power"
1da177e4
LT		 54#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
55#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
56#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
4be44fcd 57static void (*pm_idle_save) (void);
1da177e4
LT		 58module_param(max_cstate, uint, 0644);
59
60static unsigned int nocst = 0;
61module_param(nocst, uint, 0000);
62
63/*
64 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
65 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
66 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
67 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
68 * reduce history for more aggressive entry into C3
69 */
4be44fcd
LB		 70static unsigned int bm_history =
71 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
1da177e4
LT		 72module_param(bm_history, uint, 0644);
73/* --------------------------------------------------------------------------
74 Power Management
75 -------------------------------------------------------------------------- */
76
77/*
78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79 * For now disable this. Probably a bug somewhere else.
80 *
81 * To skip this limit, boot/load with a large max_cstate limit.
82 */
335f16be 83static int set_max_cstate(struct dmi_system_id *id)
1da177e4
LT		 84{
85 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
86 return 0;
87
3d35600a 88 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
4be44fcd
LB		 89 " Override with \"processor.max_cstate=%d\"\n", id->ident,
90 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
1da177e4 91
3d35600a 92 max_cstate = (long)id->driver_data;
1da177e4
LT		 93
94 return 0;
95}
96
1da177e4 97static struct dmi_system_id __initdata processor_power_dmi_table[] = {
4be44fcd
LB		 98 {set_max_cstate, "IBM ThinkPad R40e", {
99 DMI_MATCH(DMI_BIOS_VENDOR,
100 "IBM"),
101 DMI_MATCH(DMI_BIOS_VERSION,
102 "1SET60WW")},
103 (void *)1},
104 {set_max_cstate, "Medion 41700", {
105 DMI_MATCH(DMI_BIOS_VENDOR,
106 "Phoenix Technologies LTD"),
107 DMI_MATCH(DMI_BIOS_VERSION,
108 "R01-A1J")}, (void *)1},
109 {set_max_cstate, "Clevo 5600D", {
110 DMI_MATCH(DMI_BIOS_VENDOR,
111 "Phoenix Technologies LTD"),
112 DMI_MATCH(DMI_BIOS_VERSION,
113 "SHE845M0.86C.0013.D.0302131307")},
114 (void *)2},
1da177e4
LT		 115 {},
116};
117
4be44fcd 118static inline u32 ticks_elapsed(u32 t1, u32 t2)
1da177e4
LT		 119{
120 if (t2 >= t1)
121 return (t2 - t1);
122 else if (!acpi_fadt.tmr_val_ext)
123 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
124 else
125 return ((0xFFFFFFFF - t1) + t2);
126}
127
1da177e4 128static void
4be44fcd
LB		 129acpi_processor_power_activate(struct acpi_processor *pr,
130 struct acpi_processor_cx *new)
1da177e4 131{
4be44fcd 132 struct acpi_processor_cx *old;
1da177e4
LT		 133
134 if (!pr || !new)
135 return;
136
137 old = pr->power.state;
138
139 if (old)
140 old->promotion.count = 0;
4be44fcd 141 new->demotion.count = 0;
1da177e4
LT		 142
143 /* Cleanup from old state. */
144 if (old) {
145 switch (old->type) {
146 case ACPI_STATE_C3:
147 /* Disable bus master reload */
02df8b93 148 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
4be44fcd
LB		 149 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
150 ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 151 break;
152 }
153 }
154
155 /* Prepare to use new state. */
156 switch (new->type) {
157 case ACPI_STATE_C3:
158 /* Enable bus master reload */
02df8b93 159 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
4be44fcd
LB		 160 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
161 ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 162 break;
163 }
164
165 pr->power.state = new;
166
167 return;
168}
169
64c7c8f8
NP		 170static 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
4be44fcd 183static atomic_t c3_cpu_count;
1da177e4 184
4be44fcd 185static void acpi_processor_idle(void)
1da177e4 186{
4be44fcd 187 struct acpi_processor *pr = NULL;
1da177e4
LT		 188 struct acpi_processor_cx *cx = NULL;
189 struct acpi_processor_cx *next_state = NULL;
4be44fcd
LB		 190 int sleep_ticks = 0;
191 u32 t1, t2 = 0;
1da177e4 192
64c7c8f8 193 pr = processors[smp_processor_id()];
1da177e4
LT		 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;
64c7c8f8
NP		 213 if (!cx) {
214 if (pm_idle_save)
215 pm_idle_save();
216 else
217 acpi_safe_halt();
218 return;
219 }
1da177e4
LT		 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) {
4be44fcd
LB		 228 u32 bm_status = 0;
229 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
1da177e4
LT		 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,
4be44fcd 243 &bm_status, ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 244 if (bm_status) {
245 pr->power.bm_activity++;
246 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
4be44fcd 247 1, ACPI_MTX_DO_NOT_LOCK);
1da177e4
LT		 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)
4be44fcd 256 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
1da177e4
LT		 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
64c7c8f8
NP		 299 acpi_safe_halt();
300
1da177e4 301 /*
4be44fcd 302 * TBD: Can't get time duration while in C1, as resumes
1da177e4
LT		 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 */
4be44fcd
LB		 321 sleep_ticks =
322 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
1da177e4
LT		 323 break;
324
325 case ACPI_STATE_C3:
4be44fcd 326
02df8b93
VP		 327 if (pr->flags.bm_check) {
328 if (atomic_inc_return(&c3_cpu_count) ==
4be44fcd 329 num_online_cpus()) {
02df8b93
VP		 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,
4be44fcd 335 ACPI_MTX_DO_NOT_LOCK);
02df8b93
VP		 336 }
337 } else {
338 /* SMP with no shared cache... Invalidate cache */
339 ACPI_FLUSH_CPU_CACHE();
340 }
4be44fcd 341
1da177e4
LT		 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);
02df8b93
VP		 350 if (pr->flags.bm_check) {
351 /* Enable bus master arbitration */
352 atomic_dec(&c3_cpu_count);
4be44fcd
LB		 353 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
354 ACPI_MTX_DO_NOT_LOCK);
02df8b93
VP		 355 }
356
1da177e4
LT		 357 /* Re-enable interrupts */
358 local_irq_enable();
359 /* Compute time (ticks) that we were actually asleep */
4be44fcd
LB		 360 sleep_ticks =
361 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
1da177e4
LT		 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++;
4be44fcd
LB		 383 cx->demotion.count = 0;
384 if (cx->promotion.count >=
385 cx->promotion.threshold.count) {
1da177e4 386 if (pr->flags.bm_check) {
4be44fcd
LB		 387 if (!
388 (pr->power.bm_activity & cx->
389 promotion.threshold.bm)) {
390 next_state =
391 cx->promotion.state;
1da177e4
LT		 392 goto end;
393 }
4be44fcd 394 } else {
1da177e4
LT		 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
4be44fcd 419 end:
1da177e4
LT		 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);
1da177e4
LT		 436}
437
4be44fcd 438static int acpi_processor_set_power_policy(struct acpi_processor *pr)
1da177e4
LT		 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
4be44fcd 446 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
1da177e4
LT		 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 */
4be44fcd 461 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1da177e4
LT		 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;
4be44fcd 470 }
1da177e4
LT		 471
472 if (!state_is_set)
473 return_VALUE(-ENODEV);
474
475 /* demotion */
4be44fcd 476 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1da177e4
LT		 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) {
4be44fcd 499 cx->promotion.state = higher;
1da177e4
LT		 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
4be44fcd 512 return_VALUE(0);
1da177e4
LT		 513}
514
4be44fcd 515static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
1da177e4
LT		 516{
517 int i;
518
519 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
520
521 if (!pr)
522 return_VALUE(-EINVAL);
523
524 if (!pr->pblk)
525 return_VALUE(-ENODEV);
526
527 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
528 memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
529
530 /* if info is obtained from pblk/fadt, type equals state */
531 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
532 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
533 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
534
535 /* the C0 state only exists as a filler in our array,
536 * and all processors need to support C1 */
537 pr->power.states[ACPI_STATE_C0].valid = 1;
538 pr->power.states[ACPI_STATE_C1].valid = 1;
539
540 /* determine C2 and C3 address from pblk */
541 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
542 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
543
544 /* determine latencies from FADT */
545 pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
546 pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
547
548 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
549 "lvl2[0x%08x] lvl3[0x%08x]\n",
550 pr->power.states[ACPI_STATE_C2].address,
551 pr->power.states[ACPI_STATE_C3].address));
552
553 return_VALUE(0);
554}
555
4be44fcd 556static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
acf05f4b
VP		 557{
558 int i;
559
560 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
561
562 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
4be44fcd 563 memset(&(pr->power.states[i]), 0,
0b6b2f08 564 sizeof(struct acpi_processor_cx));
acf05f4b
VP		 565
566 /* if info is obtained from pblk/fadt, type equals state */
567 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
568 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
569 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
570
571 /* the C0 state only exists as a filler in our array,
572 * and all processors need to support C1 */
573 pr->power.states[ACPI_STATE_C0].valid = 1;
574 pr->power.states[ACPI_STATE_C1].valid = 1;
575
576 return_VALUE(0);
577}
578
4be44fcd 579static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
1da177e4 580{
4be44fcd
LB		 581 acpi_status status = 0;
582 acpi_integer count;
583 int i;
584 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
585 union acpi_object *cst;
1da177e4
LT		 586
587 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
588
1da177e4
LT		 589 if (nocst)
590 return_VALUE(-ENODEV);
591
592 pr->power.count = 0;
593 for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
4be44fcd 594 memset(&(pr->power.states[i]), 0,
0b6b2f08 595 sizeof(struct acpi_processor_cx));
1da177e4
LT		 596
597 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
598 if (ACPI_FAILURE(status)) {
599 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
600 return_VALUE(-ENODEV);
4be44fcd 601 }
1da177e4 602
4be44fcd 603 cst = (union acpi_object *)buffer.pointer;
1da177e4
LT		 604
605 /* There must be at least 2 elements */
606 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
4be44fcd
LB		 607 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
608 "not enough elements in _CST\n"));
1da177e4
LT		 609 status = -EFAULT;
610 goto end;
611 }
612
613 count = cst->package.elements[0].integer.value;
614
615 /* Validate number of power states. */
616 if (count < 1 || count != cst->package.count - 1) {
4be44fcd
LB		 617 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
618 "count given by _CST is not valid\n"));
1da177e4
LT		 619 status = -EFAULT;
620 goto end;
621 }
622
623 /* We support up to ACPI_PROCESSOR_MAX_POWER. */
624 if (count > ACPI_PROCESSOR_MAX_POWER) {
4be44fcd
LB		 625 printk(KERN_WARNING
626 "Limiting number of power states to max (%d)\n",
627 ACPI_PROCESSOR_MAX_POWER);
628 printk(KERN_WARNING
629 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1da177e4
LT		 630 count = ACPI_PROCESSOR_MAX_POWER;
631 }
632
633 /* Tell driver that at least _CST is supported. */
634 pr->flags.has_cst = 1;
635
636 for (i = 1; i <= count; i++) {
637 union acpi_object *element;
638 union acpi_object *obj;
639 struct acpi_power_register *reg;
640 struct acpi_processor_cx cx;
641
642 memset(&cx, 0, sizeof(cx));
643
4be44fcd 644 element = (union acpi_object *)&(cst->package.elements[i]);
1da177e4
LT		 645 if (element->type != ACPI_TYPE_PACKAGE)
646 continue;
647
648 if (element->package.count != 4)
649 continue;
650
4be44fcd 651 obj = (union acpi_object *)&(element->package.elements[0]);
1da177e4
LT		 652
653 if (obj->type != ACPI_TYPE_BUFFER)
654 continue;
655
4be44fcd 656 reg = (struct acpi_power_register *)obj->buffer.pointer;
1da177e4
LT		 657
658 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
4be44fcd 659 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
1da177e4
LT		 660 continue;
661
662 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
4be44fcd 663 0 : reg->address;
1da177e4
LT		 664
665 /* There should be an easy way to extract an integer... */
4be44fcd 666 obj = (union acpi_object *)&(element->package.elements[1]);
1da177e4
LT		 667 if (obj->type != ACPI_TYPE_INTEGER)
668 continue;
669
670 cx.type = obj->integer.value;
671
672 if ((cx.type != ACPI_STATE_C1) &&
673 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
674 continue;
675
4be44fcd 676 if ((cx.type < ACPI_STATE_C1) || (cx.type > ACPI_STATE_C3))
1da177e4
LT		 677 continue;
678
4be44fcd 679 obj = (union acpi_object *)&(element->package.elements[2]);
1da177e4
LT		 680 if (obj->type != ACPI_TYPE_INTEGER)
681 continue;
682
683 cx.latency = obj->integer.value;
684
4be44fcd 685 obj = (union acpi_object *)&(element->package.elements[3]);
1da177e4
LT		 686 if (obj->type != ACPI_TYPE_INTEGER)
687 continue;
688
689 cx.power = obj->integer.value;
690
691 (pr->power.count)++;
692 memcpy(&(pr->power.states[pr->power.count]), &cx, sizeof(cx));
693 }
694
4be44fcd
LB		 695 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
696 pr->power.count));
1da177e4
LT		 697
698 /* Validate number of power states discovered */
699 if (pr->power.count < 2)
700 status = -ENODEV;
701
4be44fcd 702 end:
1da177e4
LT		 703 acpi_os_free(buffer.pointer);
704
705 return_VALUE(status);
706}
707
1da177e4
LT		 708static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
709{
710 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
711
712 if (!cx->address)
713 return_VOID;
714
715 /*
716 * C2 latency must be less than or equal to 100
717 * microseconds.
718 */
719 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
720 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 721 "latency too large [%d]\n", cx->latency));
1da177e4
LT		 722 return_VOID;
723 }
724
1da177e4
LT		 725 /*
726 * Otherwise we've met all of our C2 requirements.
727 * Normalize the C2 latency to expidite policy
728 */
729 cx->valid = 1;
730 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
731
732 return_VOID;
733}
734
4be44fcd
LB		 735static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
736 struct acpi_processor_cx *cx)
1da177e4 737{
02df8b93
VP		 738 static int bm_check_flag;
739
1da177e4
LT		 740 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
741
742 if (!cx->address)
743 return_VOID;
744
745 /*
746 * C3 latency must be less than or equal to 1000
747 * microseconds.
748 */
749 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
750 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 751 "latency too large [%d]\n", cx->latency));
1da177e4
LT		 752 return_VOID;
753 }
754
1da177e4
LT		 755 /*
756 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
757 * DMA transfers are used by any ISA device to avoid livelock.
758 * Note that we could disable Type-F DMA (as recommended by
759 * the erratum), but this is known to disrupt certain ISA
760 * devices thus we take the conservative approach.
761 */
762 else if (errata.piix4.fdma) {
763 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 764 "C3 not supported on PIIX4 with Type-F DMA\n"));
1da177e4
LT		 765 return_VOID;
766 }
767
02df8b93
VP		 768 /* All the logic here assumes flags.bm_check is same across all CPUs */
769 if (!bm_check_flag) {
770 /* Determine whether bm_check is needed based on CPU */
771 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
772 bm_check_flag = pr->flags.bm_check;
773 } else {
774 pr->flags.bm_check = bm_check_flag;
775 }
776
777 if (pr->flags.bm_check) {
02df8b93
VP		 778 /* bus mastering control is necessary */
779 if (!pr->flags.bm_control) {
780 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd 781 "C3 support requires bus mastering control\n"));
02df8b93
VP		 782 return_VOID;
783 }
784 } else {
02df8b93
VP		 785 /*
786 * WBINVD should be set in fadt, for C3 state to be
787 * supported on when bm_check is not required.
788 */
789 if (acpi_fadt.wb_invd != 1) {
790 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd
LB		 791 "Cache invalidation should work properly"
792 " for C3 to be enabled on SMP systems\n"));
02df8b93
VP		 793 return_VOID;
794 }
795 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
4be44fcd 796 0, ACPI_MTX_DO_NOT_LOCK);
02df8b93
VP		 797 }
798
1da177e4
LT		 799 /*
800 * Otherwise we've met all of our C3 requirements.
801 * Normalize the C3 latency to expidite policy. Enable
802 * checking of bus mastering status (bm_check) so we can
803 * use this in our C3 policy
804 */
805 cx->valid = 1;
806 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1da177e4
LT		 807
808 return_VOID;
809}
810
1da177e4
LT		 811static int acpi_processor_power_verify(struct acpi_processor *pr)
812{
813 unsigned int i;
814 unsigned int working = 0;
815
4be44fcd 816 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1da177e4
LT		 817 struct acpi_processor_cx *cx = &pr->power.states[i];
818
819 switch (cx->type) {
820 case ACPI_STATE_C1:
821 cx->valid = 1;
822 break;
823
824 case ACPI_STATE_C2:
825 acpi_processor_power_verify_c2(cx);
826 break;
827
828 case ACPI_STATE_C3:
829 acpi_processor_power_verify_c3(pr, cx);
830 break;
831 }
832
833 if (cx->valid)
834 working++;
835 }
836
837 return (working);
838}
839
4be44fcd 840static int acpi_processor_get_power_info(struct acpi_processor *pr)
1da177e4
LT		 841{
842 unsigned int i;
843 int result;
844
845 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
846
847 /* NOTE: the idle thread may not be running while calling
848 * this function */
849
850 result = acpi_processor_get_power_info_cst(pr);
851 if ((result) || (acpi_processor_power_verify(pr) < 2)) {
852 result = acpi_processor_get_power_info_fadt(pr);
4a716402 853 if ((result) || (acpi_processor_power_verify(pr) < 2))
acf05f4b 854 result = acpi_processor_get_power_info_default_c1(pr);
1da177e4
LT		 855 }
856
857 /*
858 * Set Default Policy
859 * ------------------
860 * Now that we know which states are supported, set the default
861 * policy. Note that this policy can be changed dynamically
862 * (e.g. encourage deeper sleeps to conserve battery life when
863 * not on AC).
864 */
865 result = acpi_processor_set_power_policy(pr);
866 if (result)
867 return_VALUE(result);
868
869 /*
870 * if one state of type C2 or C3 is available, mark this
871 * CPU as being "idle manageable"
872 */
873 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
acf05f4b 874 if (pr->power.states[i].valid) {
1da177e4 875 pr->power.count = i;
1da177e4 876 pr->flags.power = 1;
acf05f4b 877 }
1da177e4
LT		 878 }
879
880 return_VALUE(0);
881}
882
4be44fcd 883int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1da177e4 884{
4be44fcd 885 int result = 0;
1da177e4
LT		 886
887 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
888
889 if (!pr)
4be44fcd 890 return_VALUE(-EINVAL);
1da177e4 891
4be44fcd 892 if (nocst) {
1da177e4
LT		 893 return_VALUE(-ENODEV);
894 }
895
896 if (!pr->flags.power_setup_done)
897 return_VALUE(-ENODEV);
898
899 /* Fall back to the default idle loop */
900 pm_idle = pm_idle_save;
4be44fcd 901 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
1da177e4
LT		 902
903 pr->flags.power = 0;
904 result = acpi_processor_get_power_info(pr);
905 if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
906 pm_idle = acpi_processor_idle;
907
908 return_VALUE(result);
909}
910
911/* proc interface */
912
913static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
914{
4be44fcd
LB		 915 struct acpi_processor *pr = (struct acpi_processor *)seq->private;
916 unsigned int i;
1da177e4
LT		 917
918 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
919
920 if (!pr)
921 goto end;
922
923 seq_printf(seq, "active state: C%zd\n"
4be44fcd
LB		 924 "max_cstate: C%d\n"
925 "bus master activity: %08x\n",
926 pr->power.state ? pr->power.state - pr->power.states : 0,
927 max_cstate, (unsigned)pr->power.bm_activity);
1da177e4
LT		 928
929 seq_puts(seq, "states:\n");
930
931 for (i = 1; i <= pr->power.count; i++) {
932 seq_printf(seq, " %cC%d: ",
4be44fcd
LB		 933 (&pr->power.states[i] ==
934 pr->power.state ? '*' : ' '), i);
1da177e4
LT		 935
936 if (!pr->power.states[i].valid) {
937 seq_puts(seq, "<not supported>\n");
938 continue;
939 }
940
941 switch (pr->power.states[i].type) {
942 case ACPI_STATE_C1:
943 seq_printf(seq, "type[C1] ");
944 break;
945 case ACPI_STATE_C2:
946 seq_printf(seq, "type[C2] ");
947 break;
948 case ACPI_STATE_C3:
949 seq_printf(seq, "type[C3] ");
950 break;
951 default:
952 seq_printf(seq, "type[--] ");
953 break;
954 }
955
956 if (pr->power.states[i].promotion.state)
957 seq_printf(seq, "promotion[C%zd] ",
4be44fcd
LB		 958 (pr->power.states[i].promotion.state -
959 pr->power.states));
1da177e4
LT		 960 else
961 seq_puts(seq, "promotion[--] ");
962
963 if (pr->power.states[i].demotion.state)
964 seq_printf(seq, "demotion[C%zd] ",
4be44fcd
LB		 965 (pr->power.states[i].demotion.state -
966 pr->power.states));
1da177e4
LT		 967 else
968 seq_puts(seq, "demotion[--] ");
969
970 seq_printf(seq, "latency[%03d] usage[%08d]\n",
4be44fcd
LB		 971 pr->power.states[i].latency,
972 pr->power.states[i].usage);
1da177e4
LT		 973 }
974
4be44fcd 975 end:
1da177e4
LT		 976 return_VALUE(0);
977}
978
979static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
980{
981 return single_open(file, acpi_processor_power_seq_show,
4be44fcd 982 PDE(inode)->data);
1da177e4
LT		 983}
984
985static struct file_operations acpi_processor_power_fops = {
4be44fcd
LB		 986 .open = acpi_processor_power_open_fs,
987 .read = seq_read,
988 .llseek = seq_lseek,
989 .release = single_release,
1da177e4
LT		 990};
991
4be44fcd
LB		 992int acpi_processor_power_init(struct acpi_processor *pr,
993 struct acpi_device *device)
1da177e4 994{
4be44fcd
LB		 995 acpi_status status = 0;
996 static int first_run = 0;
997 struct proc_dir_entry *entry = NULL;
1da177e4
LT		 998 unsigned int i;
999
1000 ACPI_FUNCTION_TRACE("acpi_processor_power_init");
1001
1002 if (!first_run) {
1003 dmi_check_system(processor_power_dmi_table);
1004 if (max_cstate < ACPI_C_STATES_MAX)
4be44fcd
LB		 1005 printk(KERN_NOTICE
1006 "ACPI: processor limited to max C-state %d\n",
1007 max_cstate);
1da177e4
LT		 1008 first_run++;
1009 }
1010
02df8b93
VP		 1011 if (!pr)
1012 return_VALUE(-EINVAL);
1013
1014 if (acpi_fadt.cst_cnt && !nocst) {
4be44fcd
LB		 1015 status =
1016 acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1da177e4
LT		 1017 if (ACPI_FAILURE(status)) {
1018 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1019 "Notifying BIOS of _CST ability failed\n"));
1020 }
1021 }
1022
02df8b93
VP		 1023 acpi_processor_power_init_pdc(&(pr->power), pr->id);
1024 acpi_processor_set_pdc(pr, pr->power.pdc);
1da177e4
LT		 1025 acpi_processor_get_power_info(pr);
1026
1027 /*
1028 * Install the idle handler if processor power management is supported.
1029 * Note that we use previously set idle handler will be used on
1030 * platforms that only support C1.
1031 */
1032 if ((pr->flags.power) && (!boot_option_idle_override)) {
1033 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1034 for (i = 1; i <= pr->power.count; i++)
1035 if (pr->power.states[i].valid)
4be44fcd
LB		 1036 printk(" C%d[C%d]", i,
1037 pr->power.states[i].type);
1da177e4
LT		 1038 printk(")\n");
1039
1040 if (pr->id == 0) {
1041 pm_idle_save = pm_idle;
1042 pm_idle = acpi_processor_idle;
1043 }
1044 }
1045
1046 /* 'power' [R] */
1047 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
4be44fcd 1048 S_IRUGO, acpi_device_dir(device));
1da177e4
LT		 1049 if (!entry)
1050 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
4be44fcd
LB		 1051 "Unable to create '%s' fs entry\n",
1052 ACPI_PROCESSOR_FILE_POWER));
1da177e4
LT		 1053 else {
1054 entry->proc_fops = &acpi_processor_power_fops;
1055 entry->data = acpi_driver_data(device);
1056 entry->owner = THIS_MODULE;
1057 }
1058
1059 pr->flags.power_setup_done = 1;
1060
1061 return_VALUE(0);
1062}
1063
4be44fcd
LB		 1064int acpi_processor_power_exit(struct acpi_processor *pr,
1065 struct acpi_device *device)
1da177e4
LT		 1066{
1067 ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1068
1069 pr->flags.power_setup_done = 0;
1070
1071 if (acpi_device_dir(device))
4be44fcd
LB		 1072 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1073 acpi_device_dir(device));
1da177e4
LT		 1074
1075 /* Unregister the idle handler when processor #0 is removed. */
1076 if (pr->id == 0) {
1077 pm_idle = pm_idle_save;
1078
1079 /*
1080 * We are about to unload the current idle thread pm callback
1081 * (pm_idle), Wait for all processors to update cached/local
1082 * copies of pm_idle before proceeding.
1083 */
1084 cpu_idle_wait();
1085 }
1086
1087 return_VALUE(0);
1088}
kernel source for telekom puls (alcatel/mediatek)