Merge branch 'origin'
[linux-2.6] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/cpufreq.h>
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/moduleparam.h>
40 #include <linux/sched.h>        /* need_resched() */
41
42 #include <asm/io.h>
43 #include <asm/uaccess.h>
44
45 #include <acpi/acpi_bus.h>
46 #include <acpi/processor.h>
47
48 #define ACPI_PROCESSOR_COMPONENT        0x01000000
49 #define ACPI_PROCESSOR_CLASS            "processor"
50 #define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
51 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
52 ACPI_MODULE_NAME("acpi_processor")
53 #define ACPI_PROCESSOR_FILE_POWER       "power"
54 #define US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
55 #define C2_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
56 #define C3_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
57 static void (*pm_idle_save) (void);
58 module_param(max_cstate, uint, 0644);
59
60 static unsigned int nocst = 0;
61 module_param(nocst, uint, 0000);
62
63 /*
64  * bm_history -- bit-mask with a bit per jiffy of bus-master activity
65  * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
66  * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
67  * 100 HZ: 0x0000000F: 4 jiffies = 40ms
68  * reduce history for more aggressive entry into C3
69  */
70 static unsigned int bm_history =
71     (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
72 module_param(bm_history, uint, 0644);
73 /* --------------------------------------------------------------------------
74                                 Power Management
75    -------------------------------------------------------------------------- */
76
77 /*
78  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79  * For now disable this. Probably a bug somewhere else.
80  *
81  * To skip this limit, boot/load with a large max_cstate limit.
82  */
83 static int set_max_cstate(struct dmi_system_id *id)
84 {
85         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
86                 return 0;
87
88         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
89                " Override with \"processor.max_cstate=%d\"\n", id->ident,
90                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
91
92         max_cstate = (long)id->driver_data;
93
94         return 0;
95 }
96
97 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
98    callers to only run once -AK */
99 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
100         { set_max_cstate, "IBM ThinkPad R40e", {
101           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
102           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
103         { set_max_cstate, "IBM ThinkPad R40e", {
104           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
105           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
106         { set_max_cstate, "IBM ThinkPad R40e", {
107           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
108           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
109         { set_max_cstate, "IBM ThinkPad R40e", {
110           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
111           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
112         { set_max_cstate, "IBM ThinkPad R40e", {
113           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
114           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
115         { set_max_cstate, "IBM ThinkPad R40e", {
116           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
117           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
118         { set_max_cstate, "IBM ThinkPad R40e", {
119           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
120           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
121         { set_max_cstate, "IBM ThinkPad R40e", {
122           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
123           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
124         { set_max_cstate, "IBM ThinkPad R40e", {
125           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
126           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
127         { set_max_cstate, "IBM ThinkPad R40e", {
128           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
129           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
130         { set_max_cstate, "IBM ThinkPad R40e", {
131           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
132           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
133         { set_max_cstate, "IBM ThinkPad R40e", {
134           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
135           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
136         { set_max_cstate, "IBM ThinkPad R40e", {
137           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
138           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
139         { set_max_cstate, "IBM ThinkPad R40e", {
140           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
141           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
142         { set_max_cstate, "IBM ThinkPad R40e", {
143           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
144           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
145         { set_max_cstate, "Medion 41700", {
146           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
147           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
148         { set_max_cstate, "Clevo 5600D", {
149           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
150           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
151          (void *)2},
152         {},
153 };
154
155 static inline u32 ticks_elapsed(u32 t1, u32 t2)
156 {
157         if (t2 >= t1)
158                 return (t2 - t1);
159         else if (!acpi_fadt.tmr_val_ext)
160                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
161         else
162                 return ((0xFFFFFFFF - t1) + t2);
163 }
164
165 static void
166 acpi_processor_power_activate(struct acpi_processor *pr,
167                               struct acpi_processor_cx *new)
168 {
169         struct acpi_processor_cx *old;
170
171         if (!pr || !new)
172                 return;
173
174         old = pr->power.state;
175
176         if (old)
177                 old->promotion.count = 0;
178         new->demotion.count = 0;
179
180         /* Cleanup from old state. */
181         if (old) {
182                 switch (old->type) {
183                 case ACPI_STATE_C3:
184                         /* Disable bus master reload */
185                         if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
186                                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
187                                                   ACPI_MTX_DO_NOT_LOCK);
188                         break;
189                 }
190         }
191
192         /* Prepare to use new state. */
193         switch (new->type) {
194         case ACPI_STATE_C3:
195                 /* Enable bus master reload */
196                 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
197                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
198                                           ACPI_MTX_DO_NOT_LOCK);
199                 break;
200         }
201
202         pr->power.state = new;
203
204         return;
205 }
206
207 static void acpi_safe_halt(void)
208 {
209         clear_thread_flag(TIF_POLLING_NRFLAG);
210         smp_mb__after_clear_bit();
211         if (!need_resched())
212                 safe_halt();
213         set_thread_flag(TIF_POLLING_NRFLAG);
214 }
215
216 static atomic_t c3_cpu_count;
217
218 static void acpi_processor_idle(void)
219 {
220         struct acpi_processor *pr = NULL;
221         struct acpi_processor_cx *cx = NULL;
222         struct acpi_processor_cx *next_state = NULL;
223         int sleep_ticks = 0;
224         u32 t1, t2 = 0;
225
226         pr = processors[smp_processor_id()];
227         if (!pr)
228                 return;
229
230         /*
231          * Interrupts must be disabled during bus mastering calculations and
232          * for C2/C3 transitions.
233          */
234         local_irq_disable();
235
236         /*
237          * Check whether we truly need to go idle, or should
238          * reschedule:
239          */
240         if (unlikely(need_resched())) {
241                 local_irq_enable();
242                 return;
243         }
244
245         cx = pr->power.state;
246         if (!cx) {
247                 if (pm_idle_save)
248                         pm_idle_save();
249                 else
250                         acpi_safe_halt();
251                 return;
252         }
253
254         /*
255          * Check BM Activity
256          * -----------------
257          * Check for bus mastering activity (if required), record, and check
258          * for demotion.
259          */
260         if (pr->flags.bm_check) {
261                 u32 bm_status = 0;
262                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
263
264                 if (diff > 32)
265                         diff = 32;
266
267                 while (diff) {
268                         /* if we didn't get called, assume there was busmaster activity */
269                         diff--;
270                         if (diff)
271                                 pr->power.bm_activity |= 0x1;
272                         pr->power.bm_activity <<= 1;
273                 }
274
275                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
276                                   &bm_status, ACPI_MTX_DO_NOT_LOCK);
277                 if (bm_status) {
278                         pr->power.bm_activity++;
279                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
280                                           1, ACPI_MTX_DO_NOT_LOCK);
281                 }
282                 /*
283                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
284                  * the true state of bus mastering activity; forcing us to
285                  * manually check the BMIDEA bit of each IDE channel.
286                  */
287                 else if (errata.piix4.bmisx) {
288                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
289                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
290                                 pr->power.bm_activity++;
291                 }
292
293                 pr->power.bm_check_timestamp = jiffies;
294
295                 /*
296                  * Apply bus mastering demotion policy.  Automatically demote
297                  * to avoid a faulty transition.  Note that the processor
298                  * won't enter a low-power state during this call (to this
299                  * funciton) but should upon the next.
300                  *
301                  * TBD: A better policy might be to fallback to the demotion
302                  *      state (use it for this quantum only) istead of
303                  *      demoting -- and rely on duration as our sole demotion
304                  *      qualification.  This may, however, introduce DMA
305                  *      issues (e.g. floppy DMA transfer overrun/underrun).
306                  */
307                 if (pr->power.bm_activity & cx->demotion.threshold.bm) {
308                         local_irq_enable();
309                         next_state = cx->demotion.state;
310                         goto end;
311                 }
312         }
313
314 #ifdef CONFIG_HOTPLUG_CPU
315         /*
316          * Check for P_LVL2_UP flag before entering C2 and above on
317          * an SMP system. We do it here instead of doing it at _CST/P_LVL
318          * detection phase, to work cleanly with logical CPU hotplug.
319          */
320         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
321             !pr->flags.has_cst && !acpi_fadt.plvl2_up)
322                 cx = &pr->power.states[ACPI_STATE_C1];
323 #endif
324
325         cx->usage++;
326
327         /*
328          * Sleep:
329          * ------
330          * Invoke the current Cx state to put the processor to sleep.
331          */
332         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
333                 clear_thread_flag(TIF_POLLING_NRFLAG);
334                 smp_mb__after_clear_bit();
335                 if (need_resched()) {
336                         set_thread_flag(TIF_POLLING_NRFLAG);
337                         local_irq_enable();
338                         return;
339                 }
340         }
341
342         switch (cx->type) {
343
344         case ACPI_STATE_C1:
345                 /*
346                  * Invoke C1.
347                  * Use the appropriate idle routine, the one that would
348                  * be used without acpi C-states.
349                  */
350                 if (pm_idle_save)
351                         pm_idle_save();
352                 else
353                         acpi_safe_halt();
354
355                 /*
356                  * TBD: Can't get time duration while in C1, as resumes
357                  *      go to an ISR rather than here.  Need to instrument
358                  *      base interrupt handler.
359                  */
360                 sleep_ticks = 0xFFFFFFFF;
361                 break;
362
363         case ACPI_STATE_C2:
364                 /* Get start time (ticks) */
365                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
366                 /* Invoke C2 */
367                 inb(cx->address);
368                 /* Dummy op - must do something useless after P_LVL2 read */
369                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
370                 /* Get end time (ticks) */
371                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
372                 /* Re-enable interrupts */
373                 local_irq_enable();
374                 set_thread_flag(TIF_POLLING_NRFLAG);
375                 /* Compute time (ticks) that we were actually asleep */
376                 sleep_ticks =
377                     ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
378                 break;
379
380         case ACPI_STATE_C3:
381
382                 if (pr->flags.bm_check) {
383                         if (atomic_inc_return(&c3_cpu_count) ==
384                             num_online_cpus()) {
385                                 /*
386                                  * All CPUs are trying to go to C3
387                                  * Disable bus master arbitration
388                                  */
389                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
390                                                   ACPI_MTX_DO_NOT_LOCK);
391                         }
392                 } else {
393                         /* SMP with no shared cache... Invalidate cache  */
394                         ACPI_FLUSH_CPU_CACHE();
395                 }
396
397                 /* Get start time (ticks) */
398                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
399                 /* Invoke C3 */
400                 inb(cx->address);
401                 /* Dummy op - must do something useless after P_LVL3 read */
402                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
403                 /* Get end time (ticks) */
404                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
405                 if (pr->flags.bm_check) {
406                         /* Enable bus master arbitration */
407                         atomic_dec(&c3_cpu_count);
408                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
409                                           ACPI_MTX_DO_NOT_LOCK);
410                 }
411
412                 /* Re-enable interrupts */
413                 local_irq_enable();
414                 set_thread_flag(TIF_POLLING_NRFLAG);
415                 /* Compute time (ticks) that we were actually asleep */
416                 sleep_ticks =
417                     ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
418                 break;
419
420         default:
421                 local_irq_enable();
422                 return;
423         }
424
425         next_state = pr->power.state;
426
427 #ifdef CONFIG_HOTPLUG_CPU
428         /* Don't do promotion/demotion */
429         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
430             !pr->flags.has_cst && !acpi_fadt.plvl2_up) {
431                 next_state = cx;
432                 goto end;
433         }
434 #endif
435
436         /*
437          * Promotion?
438          * ----------
439          * Track the number of longs (time asleep is greater than threshold)
440          * and promote when the count threshold is reached.  Note that bus
441          * mastering activity may prevent promotions.
442          * Do not promote above max_cstate.
443          */
444         if (cx->promotion.state &&
445             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
446                 if (sleep_ticks > cx->promotion.threshold.ticks) {
447                         cx->promotion.count++;
448                         cx->demotion.count = 0;
449                         if (cx->promotion.count >=
450                             cx->promotion.threshold.count) {
451                                 if (pr->flags.bm_check) {
452                                         if (!
453                                             (pr->power.bm_activity & cx->
454                                              promotion.threshold.bm)) {
455                                                 next_state =
456                                                     cx->promotion.state;
457                                                 goto end;
458                                         }
459                                 } else {
460                                         next_state = cx->promotion.state;
461                                         goto end;
462                                 }
463                         }
464                 }
465         }
466
467         /*
468          * Demotion?
469          * ---------
470          * Track the number of shorts (time asleep is less than time threshold)
471          * and demote when the usage threshold is reached.
472          */
473         if (cx->demotion.state) {
474                 if (sleep_ticks < cx->demotion.threshold.ticks) {
475                         cx->demotion.count++;
476                         cx->promotion.count = 0;
477                         if (cx->demotion.count >= cx->demotion.threshold.count) {
478                                 next_state = cx->demotion.state;
479                                 goto end;
480                         }
481                 }
482         }
483
484       end:
485         /*
486          * Demote if current state exceeds max_cstate
487          */
488         if ((pr->power.state - pr->power.states) > max_cstate) {
489                 if (cx->demotion.state)
490                         next_state = cx->demotion.state;
491         }
492
493         /*
494          * New Cx State?
495          * -------------
496          * If we're going to start using a new Cx state we must clean up
497          * from the previous and prepare to use the new.
498          */
499         if (next_state != pr->power.state)
500                 acpi_processor_power_activate(pr, next_state);
501 }
502
503 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
504 {
505         unsigned int i;
506         unsigned int state_is_set = 0;
507         struct acpi_processor_cx *lower = NULL;
508         struct acpi_processor_cx *higher = NULL;
509         struct acpi_processor_cx *cx;
510
511         ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
512
513         if (!pr)
514                 return_VALUE(-EINVAL);
515
516         /*
517          * This function sets the default Cx state policy (OS idle handler).
518          * Our scheme is to promote quickly to C2 but more conservatively
519          * to C3.  We're favoring C2  for its characteristics of low latency
520          * (quick response), good power savings, and ability to allow bus
521          * mastering activity.  Note that the Cx state policy is completely
522          * customizable and can be altered dynamically.
523          */
524
525         /* startup state */
526         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
527                 cx = &pr->power.states[i];
528                 if (!cx->valid)
529                         continue;
530
531                 if (!state_is_set)
532                         pr->power.state = cx;
533                 state_is_set++;
534                 break;
535         }
536
537         if (!state_is_set)
538                 return_VALUE(-ENODEV);
539
540         /* demotion */
541         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
542                 cx = &pr->power.states[i];
543                 if (!cx->valid)
544                         continue;
545
546                 if (lower) {
547                         cx->demotion.state = lower;
548                         cx->demotion.threshold.ticks = cx->latency_ticks;
549                         cx->demotion.threshold.count = 1;
550                         if (cx->type == ACPI_STATE_C3)
551                                 cx->demotion.threshold.bm = bm_history;
552                 }
553
554                 lower = cx;
555         }
556
557         /* promotion */
558         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
559                 cx = &pr->power.states[i];
560                 if (!cx->valid)
561                         continue;
562
563                 if (higher) {
564                         cx->promotion.state = higher;
565                         cx->promotion.threshold.ticks = cx->latency_ticks;
566                         if (cx->type >= ACPI_STATE_C2)
567                                 cx->promotion.threshold.count = 4;
568                         else
569                                 cx->promotion.threshold.count = 10;
570                         if (higher->type == ACPI_STATE_C3)
571                                 cx->promotion.threshold.bm = bm_history;
572                 }
573
574                 higher = cx;
575         }
576
577         return_VALUE(0);
578 }
579
580 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
581 {
582         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
583
584         if (!pr)
585                 return_VALUE(-EINVAL);
586
587         if (!pr->pblk)
588                 return_VALUE(-ENODEV);
589
590         /* if info is obtained from pblk/fadt, type equals state */
591         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
592         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
593
594 #ifndef CONFIG_HOTPLUG_CPU
595         /*
596          * Check for P_LVL2_UP flag before entering C2 and above on
597          * an SMP system. 
598          */
599         if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up)
600                 return_VALUE(-ENODEV);
601 #endif
602
603         /* determine C2 and C3 address from pblk */
604         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
605         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
606
607         /* determine latencies from FADT */
608         pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
609         pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
610
611         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
612                           "lvl2[0x%08x] lvl3[0x%08x]\n",
613                           pr->power.states[ACPI_STATE_C2].address,
614                           pr->power.states[ACPI_STATE_C3].address));
615
616         return_VALUE(0);
617 }
618
619 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
620 {
621         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
622
623         /* Zero initialize all the C-states info. */
624         memset(pr->power.states, 0, sizeof(pr->power.states));
625
626         /* set the first C-State to C1 */
627         pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
628
629         /* the C0 state only exists as a filler in our array,
630          * and all processors need to support C1 */
631         pr->power.states[ACPI_STATE_C0].valid = 1;
632         pr->power.states[ACPI_STATE_C1].valid = 1;
633
634         return_VALUE(0);
635 }
636
637 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
638 {
639         acpi_status status = 0;
640         acpi_integer count;
641         int current_count;
642         int i;
643         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
644         union acpi_object *cst;
645
646         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
647
648         if (nocst)
649                 return_VALUE(-ENODEV);
650
651         current_count = 1;
652
653         /* Zero initialize C2 onwards and prepare for fresh CST lookup */
654         for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++)
655                 memset(&(pr->power.states[i]), 0, 
656                                 sizeof(struct acpi_processor_cx));
657
658         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
659         if (ACPI_FAILURE(status)) {
660                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
661                 return_VALUE(-ENODEV);
662         }
663
664         cst = (union acpi_object *)buffer.pointer;
665
666         /* There must be at least 2 elements */
667         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
668                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
669                                   "not enough elements in _CST\n"));
670                 status = -EFAULT;
671                 goto end;
672         }
673
674         count = cst->package.elements[0].integer.value;
675
676         /* Validate number of power states. */
677         if (count < 1 || count != cst->package.count - 1) {
678                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
679                                   "count given by _CST is not valid\n"));
680                 status = -EFAULT;
681                 goto end;
682         }
683
684         /* Tell driver that at least _CST is supported. */
685         pr->flags.has_cst = 1;
686
687         for (i = 1; i <= count; i++) {
688                 union acpi_object *element;
689                 union acpi_object *obj;
690                 struct acpi_power_register *reg;
691                 struct acpi_processor_cx cx;
692
693                 memset(&cx, 0, sizeof(cx));
694
695                 element = (union acpi_object *)&(cst->package.elements[i]);
696                 if (element->type != ACPI_TYPE_PACKAGE)
697                         continue;
698
699                 if (element->package.count != 4)
700                         continue;
701
702                 obj = (union acpi_object *)&(element->package.elements[0]);
703
704                 if (obj->type != ACPI_TYPE_BUFFER)
705                         continue;
706
707                 reg = (struct acpi_power_register *)obj->buffer.pointer;
708
709                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
710                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
711                         continue;
712
713                 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
714                     0 : reg->address;
715
716                 /* There should be an easy way to extract an integer... */
717                 obj = (union acpi_object *)&(element->package.elements[1]);
718                 if (obj->type != ACPI_TYPE_INTEGER)
719                         continue;
720
721                 cx.type = obj->integer.value;
722
723                 if ((cx.type != ACPI_STATE_C1) &&
724                     (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
725                         continue;
726
727                 if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3))
728                         continue;
729
730                 obj = (union acpi_object *)&(element->package.elements[2]);
731                 if (obj->type != ACPI_TYPE_INTEGER)
732                         continue;
733
734                 cx.latency = obj->integer.value;
735
736                 obj = (union acpi_object *)&(element->package.elements[3]);
737                 if (obj->type != ACPI_TYPE_INTEGER)
738                         continue;
739
740                 cx.power = obj->integer.value;
741
742                 current_count++;
743                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
744
745                 /*
746                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
747                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
748                  */
749                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
750                         printk(KERN_WARNING
751                                "Limiting number of power states to max (%d)\n",
752                                ACPI_PROCESSOR_MAX_POWER);
753                         printk(KERN_WARNING
754                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
755                         break;
756                 }
757         }
758
759         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
760                           current_count));
761
762         /* Validate number of power states discovered */
763         if (current_count < 2)
764                 status = -EFAULT;
765
766       end:
767         acpi_os_free(buffer.pointer);
768
769         return_VALUE(status);
770 }
771
772 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
773 {
774         ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
775
776         if (!cx->address)
777                 return_VOID;
778
779         /*
780          * C2 latency must be less than or equal to 100
781          * microseconds.
782          */
783         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
784                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
785                                   "latency too large [%d]\n", cx->latency));
786                 return_VOID;
787         }
788
789         /*
790          * Otherwise we've met all of our C2 requirements.
791          * Normalize the C2 latency to expidite policy
792          */
793         cx->valid = 1;
794         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
795
796         return_VOID;
797 }
798
799 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
800                                            struct acpi_processor_cx *cx)
801 {
802         static int bm_check_flag;
803
804         ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
805
806         if (!cx->address)
807                 return_VOID;
808
809         /*
810          * C3 latency must be less than or equal to 1000
811          * microseconds.
812          */
813         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
814                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
815                                   "latency too large [%d]\n", cx->latency));
816                 return_VOID;
817         }
818
819         /*
820          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
821          * DMA transfers are used by any ISA device to avoid livelock.
822          * Note that we could disable Type-F DMA (as recommended by
823          * the erratum), but this is known to disrupt certain ISA
824          * devices thus we take the conservative approach.
825          */
826         else if (errata.piix4.fdma) {
827                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
828                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
829                 return_VOID;
830         }
831
832         /* All the logic here assumes flags.bm_check is same across all CPUs */
833         if (!bm_check_flag) {
834                 /* Determine whether bm_check is needed based on CPU  */
835                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
836                 bm_check_flag = pr->flags.bm_check;
837         } else {
838                 pr->flags.bm_check = bm_check_flag;
839         }
840
841         if (pr->flags.bm_check) {
842                 /* bus mastering control is necessary */
843                 if (!pr->flags.bm_control) {
844                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
845                                           "C3 support requires bus mastering control\n"));
846                         return_VOID;
847                 }
848         } else {
849                 /*
850                  * WBINVD should be set in fadt, for C3 state to be
851                  * supported on when bm_check is not required.
852                  */
853                 if (acpi_fadt.wb_invd != 1) {
854                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
855                                           "Cache invalidation should work properly"
856                                           " for C3 to be enabled on SMP systems\n"));
857                         return_VOID;
858                 }
859                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
860                                   0, ACPI_MTX_DO_NOT_LOCK);
861         }
862
863         /*
864          * Otherwise we've met all of our C3 requirements.
865          * Normalize the C3 latency to expidite policy.  Enable
866          * checking of bus mastering status (bm_check) so we can
867          * use this in our C3 policy
868          */
869         cx->valid = 1;
870         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
871
872         return_VOID;
873 }
874
875 static int acpi_processor_power_verify(struct acpi_processor *pr)
876 {
877         unsigned int i;
878         unsigned int working = 0;
879
880 #ifdef ARCH_APICTIMER_STOPS_ON_C3
881         struct cpuinfo_x86 *c = cpu_data + pr->id;
882         cpumask_t mask = cpumask_of_cpu(pr->id);
883
884         if (c->x86_vendor == X86_VENDOR_INTEL) {
885                 on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
886         }
887 #endif
888
889         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
890                 struct acpi_processor_cx *cx = &pr->power.states[i];
891
892                 switch (cx->type) {
893                 case ACPI_STATE_C1:
894                         cx->valid = 1;
895                         break;
896
897                 case ACPI_STATE_C2:
898                         acpi_processor_power_verify_c2(cx);
899                         break;
900
901                 case ACPI_STATE_C3:
902                         acpi_processor_power_verify_c3(pr, cx);
903 #ifdef ARCH_APICTIMER_STOPS_ON_C3
904                         if (cx->valid && c->x86_vendor == X86_VENDOR_INTEL) {
905                                 on_each_cpu(switch_APIC_timer_to_ipi,
906                                                 &mask, 1, 1);
907                         }
908 #endif
909                         break;
910                 }
911
912                 if (cx->valid)
913                         working++;
914         }
915
916         return (working);
917 }
918
919 static int acpi_processor_get_power_info(struct acpi_processor *pr)
920 {
921         unsigned int i;
922         int result;
923
924         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
925
926         /* NOTE: the idle thread may not be running while calling
927          * this function */
928
929         /* Adding C1 state */
930         acpi_processor_get_power_info_default_c1(pr);
931         result = acpi_processor_get_power_info_cst(pr);
932         if (result == -ENODEV)
933                 acpi_processor_get_power_info_fadt(pr);
934
935         pr->power.count = acpi_processor_power_verify(pr);
936
937         /*
938          * Set Default Policy
939          * ------------------
940          * Now that we know which states are supported, set the default
941          * policy.  Note that this policy can be changed dynamically
942          * (e.g. encourage deeper sleeps to conserve battery life when
943          * not on AC).
944          */
945         result = acpi_processor_set_power_policy(pr);
946         if (result)
947                 return_VALUE(result);
948
949         /*
950          * if one state of type C2 or C3 is available, mark this
951          * CPU as being "idle manageable"
952          */
953         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
954                 if (pr->power.states[i].valid) {
955                         pr->power.count = i;
956                         if (pr->power.states[i].type >= ACPI_STATE_C2)
957                                 pr->flags.power = 1;
958                 }
959         }
960
961         return_VALUE(0);
962 }
963
964 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
965 {
966         int result = 0;
967
968         ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
969
970         if (!pr)
971                 return_VALUE(-EINVAL);
972
973         if (nocst) {
974                 return_VALUE(-ENODEV);
975         }
976
977         if (!pr->flags.power_setup_done)
978                 return_VALUE(-ENODEV);
979
980         /* Fall back to the default idle loop */
981         pm_idle = pm_idle_save;
982         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
983
984         pr->flags.power = 0;
985         result = acpi_processor_get_power_info(pr);
986         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
987                 pm_idle = acpi_processor_idle;
988
989         return_VALUE(result);
990 }
991
992 /* proc interface */
993
994 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
995 {
996         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
997         unsigned int i;
998
999         ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
1000
1001         if (!pr)
1002                 goto end;
1003
1004         seq_printf(seq, "active state:            C%zd\n"
1005                    "max_cstate:              C%d\n"
1006                    "bus master activity:     %08x\n",
1007                    pr->power.state ? pr->power.state - pr->power.states : 0,
1008                    max_cstate, (unsigned)pr->power.bm_activity);
1009
1010         seq_puts(seq, "states:\n");
1011
1012         for (i = 1; i <= pr->power.count; i++) {
1013                 seq_printf(seq, "   %cC%d:                  ",
1014                            (&pr->power.states[i] ==
1015                             pr->power.state ? '*' : ' '), i);
1016
1017                 if (!pr->power.states[i].valid) {
1018                         seq_puts(seq, "<not supported>\n");
1019                         continue;
1020                 }
1021
1022                 switch (pr->power.states[i].type) {
1023                 case ACPI_STATE_C1:
1024                         seq_printf(seq, "type[C1] ");
1025                         break;
1026                 case ACPI_STATE_C2:
1027                         seq_printf(seq, "type[C2] ");
1028                         break;
1029                 case ACPI_STATE_C3:
1030                         seq_printf(seq, "type[C3] ");
1031                         break;
1032                 default:
1033                         seq_printf(seq, "type[--] ");
1034                         break;
1035                 }
1036
1037                 if (pr->power.states[i].promotion.state)
1038                         seq_printf(seq, "promotion[C%zd] ",
1039                                    (pr->power.states[i].promotion.state -
1040                                     pr->power.states));
1041                 else
1042                         seq_puts(seq, "promotion[--] ");
1043
1044                 if (pr->power.states[i].demotion.state)
1045                         seq_printf(seq, "demotion[C%zd] ",
1046                                    (pr->power.states[i].demotion.state -
1047                                     pr->power.states));
1048                 else
1049                         seq_puts(seq, "demotion[--] ");
1050
1051                 seq_printf(seq, "latency[%03d] usage[%08d]\n",
1052                            pr->power.states[i].latency,
1053                            pr->power.states[i].usage);
1054         }
1055
1056       end:
1057         return_VALUE(0);
1058 }
1059
1060 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1061 {
1062         return single_open(file, acpi_processor_power_seq_show,
1063                            PDE(inode)->data);
1064 }
1065
1066 static struct file_operations acpi_processor_power_fops = {
1067         .open = acpi_processor_power_open_fs,
1068         .read = seq_read,
1069         .llseek = seq_lseek,
1070         .release = single_release,
1071 };
1072
1073 int acpi_processor_power_init(struct acpi_processor *pr,
1074                               struct acpi_device *device)
1075 {
1076         acpi_status status = 0;
1077         static int first_run = 0;
1078         struct proc_dir_entry *entry = NULL;
1079         unsigned int i;
1080
1081         ACPI_FUNCTION_TRACE("acpi_processor_power_init");
1082
1083         if (!first_run) {
1084                 dmi_check_system(processor_power_dmi_table);
1085                 if (max_cstate < ACPI_C_STATES_MAX)
1086                         printk(KERN_NOTICE
1087                                "ACPI: processor limited to max C-state %d\n",
1088                                max_cstate);
1089                 first_run++;
1090         }
1091
1092         if (!pr)
1093                 return_VALUE(-EINVAL);
1094
1095         if (acpi_fadt.cst_cnt && !nocst) {
1096                 status =
1097                     acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1098                 if (ACPI_FAILURE(status)) {
1099                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1100                                           "Notifying BIOS of _CST ability failed\n"));
1101                 }
1102         }
1103
1104         acpi_processor_get_power_info(pr);
1105
1106         /*
1107          * Install the idle handler if processor power management is supported.
1108          * Note that we use previously set idle handler will be used on
1109          * platforms that only support C1.
1110          */
1111         if ((pr->flags.power) && (!boot_option_idle_override)) {
1112                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1113                 for (i = 1; i <= pr->power.count; i++)
1114                         if (pr->power.states[i].valid)
1115                                 printk(" C%d[C%d]", i,
1116                                        pr->power.states[i].type);
1117                 printk(")\n");
1118
1119                 if (pr->id == 0) {
1120                         pm_idle_save = pm_idle;
1121                         pm_idle = acpi_processor_idle;
1122                 }
1123         }
1124
1125         /* 'power' [R] */
1126         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1127                                   S_IRUGO, acpi_device_dir(device));
1128         if (!entry)
1129                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1130                                   "Unable to create '%s' fs entry\n",
1131                                   ACPI_PROCESSOR_FILE_POWER));
1132         else {
1133                 entry->proc_fops = &acpi_processor_power_fops;
1134                 entry->data = acpi_driver_data(device);
1135                 entry->owner = THIS_MODULE;
1136         }
1137
1138         pr->flags.power_setup_done = 1;
1139
1140         return_VALUE(0);
1141 }
1142
1143 int acpi_processor_power_exit(struct acpi_processor *pr,
1144                               struct acpi_device *device)
1145 {
1146         ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1147
1148         pr->flags.power_setup_done = 0;
1149
1150         if (acpi_device_dir(device))
1151                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1152                                   acpi_device_dir(device));
1153
1154         /* Unregister the idle handler when processor #0 is removed. */
1155         if (pr->id == 0) {
1156                 pm_idle = pm_idle_save;
1157
1158                 /*
1159                  * We are about to unload the current idle thread pm callback
1160                  * (pm_idle), Wait for all processors to update cached/local
1161                  * copies of pm_idle before proceeding.
1162                  */
1163                 cpu_idle_wait();
1164         }
1165
1166         return_VALUE(0);
1167 }