ACPI: add 'const' to several ACPI file_operations
[linux-3.10.git] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/cpufreq.h>
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/moduleparam.h>
40 #include <linux/sched.h>        /* need_resched() */
41
42 #include <asm/io.h>
43 #include <asm/uaccess.h>
44
45 #include <acpi/acpi_bus.h>
46 #include <acpi/processor.h>
47
48 #define ACPI_PROCESSOR_COMPONENT        0x01000000
49 #define ACPI_PROCESSOR_CLASS            "processor"
50 #define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
51 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
52 ACPI_MODULE_NAME("acpi_processor")
53 #define ACPI_PROCESSOR_FILE_POWER       "power"
54 #define US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
55 #define C2_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
56 #define C3_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
57 static void (*pm_idle_save) (void) __read_mostly;
58 module_param(max_cstate, uint, 0644);
59
60 static unsigned int nocst __read_mostly;
61 module_param(nocst, uint, 0000);
62
63 /*
64  * bm_history -- bit-mask with a bit per jiffy of bus-master activity
65  * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
66  * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
67  * 100 HZ: 0x0000000F: 4 jiffies = 40ms
68  * reduce history for more aggressive entry into C3
69  */
70 static unsigned int bm_history __read_mostly =
71     (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
72 module_param(bm_history, uint, 0644);
73 /* --------------------------------------------------------------------------
74                                 Power Management
75    -------------------------------------------------------------------------- */
76
77 /*
78  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79  * For now disable this. Probably a bug somewhere else.
80  *
81  * To skip this limit, boot/load with a large max_cstate limit.
82  */
83 static int set_max_cstate(struct dmi_system_id *id)
84 {
85         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
86                 return 0;
87
88         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
89                " Override with \"processor.max_cstate=%d\"\n", id->ident,
90                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
91
92         max_cstate = (long)id->driver_data;
93
94         return 0;
95 }
96
97 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
98    callers to only run once -AK */
99 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
100         { set_max_cstate, "IBM ThinkPad R40e", {
101           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
102           DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
103         { set_max_cstate, "IBM ThinkPad R40e", {
104           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
105           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
106         { set_max_cstate, "IBM ThinkPad R40e", {
107           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
108           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
109         { set_max_cstate, "IBM ThinkPad R40e", {
110           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
111           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
112         { set_max_cstate, "IBM ThinkPad R40e", {
113           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
114           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
115         { set_max_cstate, "IBM ThinkPad R40e", {
116           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
117           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
118         { set_max_cstate, "IBM ThinkPad R40e", {
119           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
120           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
121         { set_max_cstate, "IBM ThinkPad R40e", {
122           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
123           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
124         { set_max_cstate, "IBM ThinkPad R40e", {
125           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
126           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
127         { set_max_cstate, "IBM ThinkPad R40e", {
128           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
129           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
130         { set_max_cstate, "IBM ThinkPad R40e", {
131           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
132           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
133         { set_max_cstate, "IBM ThinkPad R40e", {
134           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
135           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
136         { set_max_cstate, "IBM ThinkPad R40e", {
137           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
138           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
139         { set_max_cstate, "IBM ThinkPad R40e", {
140           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
141           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
142         { set_max_cstate, "IBM ThinkPad R40e", {
143           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
144           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
145         { set_max_cstate, "IBM ThinkPad R40e", {
146           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
147           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
148         { set_max_cstate, "Medion 41700", {
149           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
150           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
151         { set_max_cstate, "Clevo 5600D", {
152           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
153           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
154          (void *)2},
155         {},
156 };
157
158 static inline u32 ticks_elapsed(u32 t1, u32 t2)
159 {
160         if (t2 >= t1)
161                 return (t2 - t1);
162         else if (!acpi_fadt.tmr_val_ext)
163                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
164         else
165                 return ((0xFFFFFFFF - t1) + t2);
166 }
167
168 static void
169 acpi_processor_power_activate(struct acpi_processor *pr,
170                               struct acpi_processor_cx *new)
171 {
172         struct acpi_processor_cx *old;
173
174         if (!pr || !new)
175                 return;
176
177         old = pr->power.state;
178
179         if (old)
180                 old->promotion.count = 0;
181         new->demotion.count = 0;
182
183         /* Cleanup from old state. */
184         if (old) {
185                 switch (old->type) {
186                 case ACPI_STATE_C3:
187                         /* Disable bus master reload */
188                         if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
189                                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
190                                                   ACPI_MTX_DO_NOT_LOCK);
191                         break;
192                 }
193         }
194
195         /* Prepare to use new state. */
196         switch (new->type) {
197         case ACPI_STATE_C3:
198                 /* Enable bus master reload */
199                 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
200                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
201                                           ACPI_MTX_DO_NOT_LOCK);
202                 break;
203         }
204
205         pr->power.state = new;
206
207         return;
208 }
209
210 static void acpi_safe_halt(void)
211 {
212         current_thread_info()->status &= ~TS_POLLING;
213         smp_mb__after_clear_bit();
214         if (!need_resched())
215                 safe_halt();
216         current_thread_info()->status |= TS_POLLING;
217 }
218
219 static atomic_t c3_cpu_count;
220
221 static void acpi_processor_idle(void)
222 {
223         struct acpi_processor *pr = NULL;
224         struct acpi_processor_cx *cx = NULL;
225         struct acpi_processor_cx *next_state = NULL;
226         int sleep_ticks = 0;
227         u32 t1, t2 = 0;
228
229         pr = processors[smp_processor_id()];
230         if (!pr)
231                 return;
232
233         /*
234          * Interrupts must be disabled during bus mastering calculations and
235          * for C2/C3 transitions.
236          */
237         local_irq_disable();
238
239         /*
240          * Check whether we truly need to go idle, or should
241          * reschedule:
242          */
243         if (unlikely(need_resched())) {
244                 local_irq_enable();
245                 return;
246         }
247
248         cx = pr->power.state;
249         if (!cx) {
250                 if (pm_idle_save)
251                         pm_idle_save();
252                 else
253                         acpi_safe_halt();
254                 return;
255         }
256
257         /*
258          * Check BM Activity
259          * -----------------
260          * Check for bus mastering activity (if required), record, and check
261          * for demotion.
262          */
263         if (pr->flags.bm_check) {
264                 u32 bm_status = 0;
265                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
266
267                 if (diff > 31)
268                         diff = 31;
269
270                 pr->power.bm_activity <<= diff;
271
272                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
273                                   &bm_status, ACPI_MTX_DO_NOT_LOCK);
274                 if (bm_status) {
275                         pr->power.bm_activity |= 0x1;
276                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
277                                           1, ACPI_MTX_DO_NOT_LOCK);
278                 }
279                 /*
280                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
281                  * the true state of bus mastering activity; forcing us to
282                  * manually check the BMIDEA bit of each IDE channel.
283                  */
284                 else if (errata.piix4.bmisx) {
285                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
286                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
287                                 pr->power.bm_activity |= 0x1;
288                 }
289
290                 pr->power.bm_check_timestamp = jiffies;
291
292                 /*
293                  * If bus mastering is or was active this jiffy, demote
294                  * to avoid a faulty transition.  Note that the processor
295                  * won't enter a low-power state during this call (to this
296                  * function) but should upon the next.
297                  *
298                  * TBD: A better policy might be to fallback to the demotion
299                  *      state (use it for this quantum only) istead of
300                  *      demoting -- and rely on duration as our sole demotion
301                  *      qualification.  This may, however, introduce DMA
302                  *      issues (e.g. floppy DMA transfer overrun/underrun).
303                  */
304                 if ((pr->power.bm_activity & 0x1) &&
305                     cx->demotion.threshold.bm) {
306                         local_irq_enable();
307                         next_state = cx->demotion.state;
308                         goto end;
309                 }
310         }
311
312 #ifdef CONFIG_HOTPLUG_CPU
313         /*
314          * Check for P_LVL2_UP flag before entering C2 and above on
315          * an SMP system. We do it here instead of doing it at _CST/P_LVL
316          * detection phase, to work cleanly with logical CPU hotplug.
317          */
318         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
319             !pr->flags.has_cst && !acpi_fadt.plvl2_up)
320                 cx = &pr->power.states[ACPI_STATE_C1];
321 #endif
322
323         /*
324          * Sleep:
325          * ------
326          * Invoke the current Cx state to put the processor to sleep.
327          */
328         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
329                 current_thread_info()->status &= ~TS_POLLING;
330                 smp_mb__after_clear_bit();
331                 if (need_resched()) {
332                         current_thread_info()->status |= TS_POLLING;
333                         local_irq_enable();
334                         return;
335                 }
336         }
337
338         switch (cx->type) {
339
340         case ACPI_STATE_C1:
341                 /*
342                  * Invoke C1.
343                  * Use the appropriate idle routine, the one that would
344                  * be used without acpi C-states.
345                  */
346                 if (pm_idle_save)
347                         pm_idle_save();
348                 else
349                         acpi_safe_halt();
350
351                 /*
352                  * TBD: Can't get time duration while in C1, as resumes
353                  *      go to an ISR rather than here.  Need to instrument
354                  *      base interrupt handler.
355                  */
356                 sleep_ticks = 0xFFFFFFFF;
357                 break;
358
359         case ACPI_STATE_C2:
360                 /* Get start time (ticks) */
361                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
362                 /* Invoke C2 */
363                 inb(cx->address);
364                 /* Dummy wait op - must do something useless after P_LVL2 read
365                    because chipsets cannot guarantee that STPCLK# signal
366                    gets asserted in time to freeze execution properly. */
367                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
368                 /* Get end time (ticks) */
369                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
370
371 #ifdef CONFIG_GENERIC_TIME
372                 /* TSC halts in C2, so notify users */
373                 mark_tsc_unstable();
374 #endif
375                 /* Re-enable interrupts */
376                 local_irq_enable();
377                 current_thread_info()->status |= TS_POLLING;
378                 /* Compute time (ticks) that we were actually asleep */
379                 sleep_ticks =
380                     ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
381                 break;
382
383         case ACPI_STATE_C3:
384
385                 if (pr->flags.bm_check) {
386                         if (atomic_inc_return(&c3_cpu_count) ==
387                             num_online_cpus()) {
388                                 /*
389                                  * All CPUs are trying to go to C3
390                                  * Disable bus master arbitration
391                                  */
392                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
393                                                   ACPI_MTX_DO_NOT_LOCK);
394                         }
395                 } else {
396                         /* SMP with no shared cache... Invalidate cache  */
397                         ACPI_FLUSH_CPU_CACHE();
398                 }
399
400                 /* Get start time (ticks) */
401                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
402                 /* Invoke C3 */
403                 inb(cx->address);
404                 /* Dummy wait op (see above) */
405                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
406                 /* Get end time (ticks) */
407                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
408                 if (pr->flags.bm_check) {
409                         /* Enable bus master arbitration */
410                         atomic_dec(&c3_cpu_count);
411                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
412                                           ACPI_MTX_DO_NOT_LOCK);
413                 }
414
415 #ifdef CONFIG_GENERIC_TIME
416                 /* TSC halts in C3, so notify users */
417                 mark_tsc_unstable();
418 #endif
419                 /* Re-enable interrupts */
420                 local_irq_enable();
421                 current_thread_info()->status |= TS_POLLING;
422                 /* Compute time (ticks) that we were actually asleep */
423                 sleep_ticks =
424                     ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
425                 break;
426
427         default:
428                 local_irq_enable();
429                 return;
430         }
431         cx->usage++;
432         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
433                 cx->time += sleep_ticks;
434
435         next_state = pr->power.state;
436
437 #ifdef CONFIG_HOTPLUG_CPU
438         /* Don't do promotion/demotion */
439         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
440             !pr->flags.has_cst && !acpi_fadt.plvl2_up) {
441                 next_state = cx;
442                 goto end;
443         }
444 #endif
445
446         /*
447          * Promotion?
448          * ----------
449          * Track the number of longs (time asleep is greater than threshold)
450          * and promote when the count threshold is reached.  Note that bus
451          * mastering activity may prevent promotions.
452          * Do not promote above max_cstate.
453          */
454         if (cx->promotion.state &&
455             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
456                 if (sleep_ticks > cx->promotion.threshold.ticks) {
457                         cx->promotion.count++;
458                         cx->demotion.count = 0;
459                         if (cx->promotion.count >=
460                             cx->promotion.threshold.count) {
461                                 if (pr->flags.bm_check) {
462                                         if (!
463                                             (pr->power.bm_activity & cx->
464                                              promotion.threshold.bm)) {
465                                                 next_state =
466                                                     cx->promotion.state;
467                                                 goto end;
468                                         }
469                                 } else {
470                                         next_state = cx->promotion.state;
471                                         goto end;
472                                 }
473                         }
474                 }
475         }
476
477         /*
478          * Demotion?
479          * ---------
480          * Track the number of shorts (time asleep is less than time threshold)
481          * and demote when the usage threshold is reached.
482          */
483         if (cx->demotion.state) {
484                 if (sleep_ticks < cx->demotion.threshold.ticks) {
485                         cx->demotion.count++;
486                         cx->promotion.count = 0;
487                         if (cx->demotion.count >= cx->demotion.threshold.count) {
488                                 next_state = cx->demotion.state;
489                                 goto end;
490                         }
491                 }
492         }
493
494       end:
495         /*
496          * Demote if current state exceeds max_cstate
497          */
498         if ((pr->power.state - pr->power.states) > max_cstate) {
499                 if (cx->demotion.state)
500                         next_state = cx->demotion.state;
501         }
502
503         /*
504          * New Cx State?
505          * -------------
506          * If we're going to start using a new Cx state we must clean up
507          * from the previous and prepare to use the new.
508          */
509         if (next_state != pr->power.state)
510                 acpi_processor_power_activate(pr, next_state);
511 }
512
513 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
514 {
515         unsigned int i;
516         unsigned int state_is_set = 0;
517         struct acpi_processor_cx *lower = NULL;
518         struct acpi_processor_cx *higher = NULL;
519         struct acpi_processor_cx *cx;
520
521
522         if (!pr)
523                 return -EINVAL;
524
525         /*
526          * This function sets the default Cx state policy (OS idle handler).
527          * Our scheme is to promote quickly to C2 but more conservatively
528          * to C3.  We're favoring C2  for its characteristics of low latency
529          * (quick response), good power savings, and ability to allow bus
530          * mastering activity.  Note that the Cx state policy is completely
531          * customizable and can be altered dynamically.
532          */
533
534         /* startup state */
535         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
536                 cx = &pr->power.states[i];
537                 if (!cx->valid)
538                         continue;
539
540                 if (!state_is_set)
541                         pr->power.state = cx;
542                 state_is_set++;
543                 break;
544         }
545
546         if (!state_is_set)
547                 return -ENODEV;
548
549         /* demotion */
550         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
551                 cx = &pr->power.states[i];
552                 if (!cx->valid)
553                         continue;
554
555                 if (lower) {
556                         cx->demotion.state = lower;
557                         cx->demotion.threshold.ticks = cx->latency_ticks;
558                         cx->demotion.threshold.count = 1;
559                         if (cx->type == ACPI_STATE_C3)
560                                 cx->demotion.threshold.bm = bm_history;
561                 }
562
563                 lower = cx;
564         }
565
566         /* promotion */
567         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
568                 cx = &pr->power.states[i];
569                 if (!cx->valid)
570                         continue;
571
572                 if (higher) {
573                         cx->promotion.state = higher;
574                         cx->promotion.threshold.ticks = cx->latency_ticks;
575                         if (cx->type >= ACPI_STATE_C2)
576                                 cx->promotion.threshold.count = 4;
577                         else
578                                 cx->promotion.threshold.count = 10;
579                         if (higher->type == ACPI_STATE_C3)
580                                 cx->promotion.threshold.bm = bm_history;
581                 }
582
583                 higher = cx;
584         }
585
586         return 0;
587 }
588
589 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
590 {
591
592         if (!pr)
593                 return -EINVAL;
594
595         if (!pr->pblk)
596                 return -ENODEV;
597
598         /* if info is obtained from pblk/fadt, type equals state */
599         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
600         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
601
602 #ifndef CONFIG_HOTPLUG_CPU
603         /*
604          * Check for P_LVL2_UP flag before entering C2 and above on
605          * an SMP system. 
606          */
607         if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up)
608                 return -ENODEV;
609 #endif
610
611         /* determine C2 and C3 address from pblk */
612         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
613         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
614
615         /* determine latencies from FADT */
616         pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
617         pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
618
619         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
620                           "lvl2[0x%08x] lvl3[0x%08x]\n",
621                           pr->power.states[ACPI_STATE_C2].address,
622                           pr->power.states[ACPI_STATE_C3].address));
623
624         return 0;
625 }
626
627 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
628 {
629
630         /* Zero initialize all the C-states info. */
631         memset(pr->power.states, 0, sizeof(pr->power.states));
632
633         /* set the first C-State to C1 */
634         pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
635
636         /* the C0 state only exists as a filler in our array,
637          * and all processors need to support C1 */
638         pr->power.states[ACPI_STATE_C0].valid = 1;
639         pr->power.states[ACPI_STATE_C1].valid = 1;
640
641         return 0;
642 }
643
644 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
645 {
646         acpi_status status = 0;
647         acpi_integer count;
648         int current_count;
649         int i;
650         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
651         union acpi_object *cst;
652
653
654         if (nocst)
655                 return -ENODEV;
656
657         current_count = 1;
658
659         /* Zero initialize C2 onwards and prepare for fresh CST lookup */
660         for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++)
661                 memset(&(pr->power.states[i]), 0, 
662                                 sizeof(struct acpi_processor_cx));
663
664         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
665         if (ACPI_FAILURE(status)) {
666                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
667                 return -ENODEV;
668         }
669
670         cst = (union acpi_object *)buffer.pointer;
671
672         /* There must be at least 2 elements */
673         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
674                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
675                 status = -EFAULT;
676                 goto end;
677         }
678
679         count = cst->package.elements[0].integer.value;
680
681         /* Validate number of power states. */
682         if (count < 1 || count != cst->package.count - 1) {
683                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
684                 status = -EFAULT;
685                 goto end;
686         }
687
688         /* Tell driver that at least _CST is supported. */
689         pr->flags.has_cst = 1;
690
691         for (i = 1; i <= count; i++) {
692                 union acpi_object *element;
693                 union acpi_object *obj;
694                 struct acpi_power_register *reg;
695                 struct acpi_processor_cx cx;
696
697                 memset(&cx, 0, sizeof(cx));
698
699                 element = (union acpi_object *)&(cst->package.elements[i]);
700                 if (element->type != ACPI_TYPE_PACKAGE)
701                         continue;
702
703                 if (element->package.count != 4)
704                         continue;
705
706                 obj = (union acpi_object *)&(element->package.elements[0]);
707
708                 if (obj->type != ACPI_TYPE_BUFFER)
709                         continue;
710
711                 reg = (struct acpi_power_register *)obj->buffer.pointer;
712
713                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
714                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
715                         continue;
716
717                 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
718                     0 : reg->address;
719
720                 /* There should be an easy way to extract an integer... */
721                 obj = (union acpi_object *)&(element->package.elements[1]);
722                 if (obj->type != ACPI_TYPE_INTEGER)
723                         continue;
724
725                 cx.type = obj->integer.value;
726
727                 if ((cx.type != ACPI_STATE_C1) &&
728                     (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
729                         continue;
730
731                 if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3))
732                         continue;
733
734                 obj = (union acpi_object *)&(element->package.elements[2]);
735                 if (obj->type != ACPI_TYPE_INTEGER)
736                         continue;
737
738                 cx.latency = obj->integer.value;
739
740                 obj = (union acpi_object *)&(element->package.elements[3]);
741                 if (obj->type != ACPI_TYPE_INTEGER)
742                         continue;
743
744                 cx.power = obj->integer.value;
745
746                 current_count++;
747                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
748
749                 /*
750                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
751                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
752                  */
753                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
754                         printk(KERN_WARNING
755                                "Limiting number of power states to max (%d)\n",
756                                ACPI_PROCESSOR_MAX_POWER);
757                         printk(KERN_WARNING
758                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
759                         break;
760                 }
761         }
762
763         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
764                           current_count));
765
766         /* Validate number of power states discovered */
767         if (current_count < 2)
768                 status = -EFAULT;
769
770       end:
771         kfree(buffer.pointer);
772
773         return status;
774 }
775
776 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
777 {
778
779         if (!cx->address)
780                 return;
781
782         /*
783          * C2 latency must be less than or equal to 100
784          * microseconds.
785          */
786         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
787                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
788                                   "latency too large [%d]\n", cx->latency));
789                 return;
790         }
791
792         /*
793          * Otherwise we've met all of our C2 requirements.
794          * Normalize the C2 latency to expidite policy
795          */
796         cx->valid = 1;
797         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
798
799         return;
800 }
801
802 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
803                                            struct acpi_processor_cx *cx)
804 {
805         static int bm_check_flag;
806
807
808         if (!cx->address)
809                 return;
810
811         /*
812          * C3 latency must be less than or equal to 1000
813          * microseconds.
814          */
815         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
816                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
817                                   "latency too large [%d]\n", cx->latency));
818                 return;
819         }
820
821         /*
822          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
823          * DMA transfers are used by any ISA device to avoid livelock.
824          * Note that we could disable Type-F DMA (as recommended by
825          * the erratum), but this is known to disrupt certain ISA
826          * devices thus we take the conservative approach.
827          */
828         else if (errata.piix4.fdma) {
829                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
830                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
831                 return;
832         }
833
834         /* All the logic here assumes flags.bm_check is same across all CPUs */
835         if (!bm_check_flag) {
836                 /* Determine whether bm_check is needed based on CPU  */
837                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
838                 bm_check_flag = pr->flags.bm_check;
839         } else {
840                 pr->flags.bm_check = bm_check_flag;
841         }
842
843         if (pr->flags.bm_check) {
844                 /* bus mastering control is necessary */
845                 if (!pr->flags.bm_control) {
846                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
847                                           "C3 support requires bus mastering control\n"));
848                         return;
849                 }
850         } else {
851                 /*
852                  * WBINVD should be set in fadt, for C3 state to be
853                  * supported on when bm_check is not required.
854                  */
855                 if (acpi_fadt.wb_invd != 1) {
856                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
857                                           "Cache invalidation should work properly"
858                                           " for C3 to be enabled on SMP systems\n"));
859                         return;
860                 }
861                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
862                                   0, ACPI_MTX_DO_NOT_LOCK);
863         }
864
865         /*
866          * Otherwise we've met all of our C3 requirements.
867          * Normalize the C3 latency to expidite policy.  Enable
868          * checking of bus mastering status (bm_check) so we can
869          * use this in our C3 policy
870          */
871         cx->valid = 1;
872         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
873
874         return;
875 }
876
877 static int acpi_processor_power_verify(struct acpi_processor *pr)
878 {
879         unsigned int i;
880         unsigned int working = 0;
881
882 #ifdef ARCH_APICTIMER_STOPS_ON_C3
883         int timer_broadcast = 0;
884         cpumask_t mask = cpumask_of_cpu(pr->id);
885         on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
886 #endif
887
888         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
889                 struct acpi_processor_cx *cx = &pr->power.states[i];
890
891                 switch (cx->type) {
892                 case ACPI_STATE_C1:
893                         cx->valid = 1;
894                         break;
895
896                 case ACPI_STATE_C2:
897                         acpi_processor_power_verify_c2(cx);
898 #ifdef ARCH_APICTIMER_STOPS_ON_C3
899                         /* Some AMD systems fake C3 as C2, but still
900                            have timer troubles */
901                         if (cx->valid && 
902                                 boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
903                                 timer_broadcast++;
904 #endif
905                         break;
906
907                 case ACPI_STATE_C3:
908                         acpi_processor_power_verify_c3(pr, cx);
909 #ifdef ARCH_APICTIMER_STOPS_ON_C3
910                         if (cx->valid)
911                                 timer_broadcast++;
912 #endif
913                         break;
914                 }
915
916                 if (cx->valid)
917                         working++;
918         }
919
920 #ifdef ARCH_APICTIMER_STOPS_ON_C3
921         if (timer_broadcast)
922                 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
923 #endif
924
925         return (working);
926 }
927
928 static int acpi_processor_get_power_info(struct acpi_processor *pr)
929 {
930         unsigned int i;
931         int result;
932
933
934         /* NOTE: the idle thread may not be running while calling
935          * this function */
936
937         /* Adding C1 state */
938         acpi_processor_get_power_info_default_c1(pr);
939         result = acpi_processor_get_power_info_cst(pr);
940         if (result == -ENODEV)
941                 acpi_processor_get_power_info_fadt(pr);
942
943         pr->power.count = acpi_processor_power_verify(pr);
944
945         /*
946          * Set Default Policy
947          * ------------------
948          * Now that we know which states are supported, set the default
949          * policy.  Note that this policy can be changed dynamically
950          * (e.g. encourage deeper sleeps to conserve battery life when
951          * not on AC).
952          */
953         result = acpi_processor_set_power_policy(pr);
954         if (result)
955                 return result;
956
957         /*
958          * if one state of type C2 or C3 is available, mark this
959          * CPU as being "idle manageable"
960          */
961         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
962                 if (pr->power.states[i].valid) {
963                         pr->power.count = i;
964                         if (pr->power.states[i].type >= ACPI_STATE_C2)
965                                 pr->flags.power = 1;
966                 }
967         }
968
969         return 0;
970 }
971
972 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
973 {
974         int result = 0;
975
976
977         if (!pr)
978                 return -EINVAL;
979
980         if (nocst) {
981                 return -ENODEV;
982         }
983
984         if (!pr->flags.power_setup_done)
985                 return -ENODEV;
986
987         /* Fall back to the default idle loop */
988         pm_idle = pm_idle_save;
989         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
990
991         pr->flags.power = 0;
992         result = acpi_processor_get_power_info(pr);
993         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
994                 pm_idle = acpi_processor_idle;
995
996         return result;
997 }
998
999 /* proc interface */
1000
1001 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1002 {
1003         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
1004         unsigned int i;
1005
1006
1007         if (!pr)
1008                 goto end;
1009
1010         seq_printf(seq, "active state:            C%zd\n"
1011                    "max_cstate:              C%d\n"
1012                    "bus master activity:     %08x\n",
1013                    pr->power.state ? pr->power.state - pr->power.states : 0,
1014                    max_cstate, (unsigned)pr->power.bm_activity);
1015
1016         seq_puts(seq, "states:\n");
1017
1018         for (i = 1; i <= pr->power.count; i++) {
1019                 seq_printf(seq, "   %cC%d:                  ",
1020                            (&pr->power.states[i] ==
1021                             pr->power.state ? '*' : ' '), i);
1022
1023                 if (!pr->power.states[i].valid) {
1024                         seq_puts(seq, "<not supported>\n");
1025                         continue;
1026                 }
1027
1028                 switch (pr->power.states[i].type) {
1029                 case ACPI_STATE_C1:
1030                         seq_printf(seq, "type[C1] ");
1031                         break;
1032                 case ACPI_STATE_C2:
1033                         seq_printf(seq, "type[C2] ");
1034                         break;
1035                 case ACPI_STATE_C3:
1036                         seq_printf(seq, "type[C3] ");
1037                         break;
1038                 default:
1039                         seq_printf(seq, "type[--] ");
1040                         break;
1041                 }
1042
1043                 if (pr->power.states[i].promotion.state)
1044                         seq_printf(seq, "promotion[C%zd] ",
1045                                    (pr->power.states[i].promotion.state -
1046                                     pr->power.states));
1047                 else
1048                         seq_puts(seq, "promotion[--] ");
1049
1050                 if (pr->power.states[i].demotion.state)
1051                         seq_printf(seq, "demotion[C%zd] ",
1052                                    (pr->power.states[i].demotion.state -
1053                                     pr->power.states));
1054                 else
1055                         seq_puts(seq, "demotion[--] ");
1056
1057                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1058                            pr->power.states[i].latency,
1059                            pr->power.states[i].usage,
1060                            pr->power.states[i].time);
1061         }
1062
1063       end:
1064         return 0;
1065 }
1066
1067 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1068 {
1069         return single_open(file, acpi_processor_power_seq_show,
1070                            PDE(inode)->data);
1071 }
1072
1073 static const struct file_operations acpi_processor_power_fops = {
1074         .open = acpi_processor_power_open_fs,
1075         .read = seq_read,
1076         .llseek = seq_lseek,
1077         .release = single_release,
1078 };
1079
1080 int acpi_processor_power_init(struct acpi_processor *pr,
1081                               struct acpi_device *device)
1082 {
1083         acpi_status status = 0;
1084         static int first_run;
1085         struct proc_dir_entry *entry = NULL;
1086         unsigned int i;
1087
1088
1089         if (!first_run) {
1090                 dmi_check_system(processor_power_dmi_table);
1091                 if (max_cstate < ACPI_C_STATES_MAX)
1092                         printk(KERN_NOTICE
1093                                "ACPI: processor limited to max C-state %d\n",
1094                                max_cstate);
1095                 first_run++;
1096         }
1097
1098         if (!pr)
1099                 return -EINVAL;
1100
1101         if (acpi_fadt.cst_cnt && !nocst) {
1102                 status =
1103                     acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1104                 if (ACPI_FAILURE(status)) {
1105                         ACPI_EXCEPTION((AE_INFO, status,
1106                                         "Notifying BIOS of _CST ability failed"));
1107                 }
1108         }
1109
1110         acpi_processor_get_power_info(pr);
1111
1112         /*
1113          * Install the idle handler if processor power management is supported.
1114          * Note that we use previously set idle handler will be used on
1115          * platforms that only support C1.
1116          */
1117         if ((pr->flags.power) && (!boot_option_idle_override)) {
1118                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1119                 for (i = 1; i <= pr->power.count; i++)
1120                         if (pr->power.states[i].valid)
1121                                 printk(" C%d[C%d]", i,
1122                                        pr->power.states[i].type);
1123                 printk(")\n");
1124
1125                 if (pr->id == 0) {
1126                         pm_idle_save = pm_idle;
1127                         pm_idle = acpi_processor_idle;
1128                 }
1129         }
1130
1131         /* 'power' [R] */
1132         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1133                                   S_IRUGO, acpi_device_dir(device));
1134         if (!entry)
1135                 return -EIO;
1136         else {
1137                 entry->proc_fops = &acpi_processor_power_fops;
1138                 entry->data = acpi_driver_data(device);
1139                 entry->owner = THIS_MODULE;
1140         }
1141
1142         pr->flags.power_setup_done = 1;
1143
1144         return 0;
1145 }
1146
1147 int acpi_processor_power_exit(struct acpi_processor *pr,
1148                               struct acpi_device *device)
1149 {
1150
1151         pr->flags.power_setup_done = 0;
1152
1153         if (acpi_device_dir(device))
1154                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1155                                   acpi_device_dir(device));
1156
1157         /* Unregister the idle handler when processor #0 is removed. */
1158         if (pr->id == 0) {
1159                 pm_idle = pm_idle_save;
1160
1161                 /*
1162                  * We are about to unload the current idle thread pm callback
1163                  * (pm_idle), Wait for all processors to update cached/local
1164                  * copies of pm_idle before proceeding.
1165                  */
1166                 cpu_idle_wait();
1167         }
1168
1169         return 0;
1170 }