]> nv-tegra.nvidia Code Review - linux-2.6.git/blob - drivers/acpi/processor_idle.c
Merge branch 'x86-64'
[linux-2.6.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       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,"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         current_thread_info()->status &= ~TS_POLLING;
210         smp_mb__after_clear_bit();
211         if (!need_resched())
212                 safe_halt();
213         current_thread_info()->status |= TS_POLLING;
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                 current_thread_info()->status &= ~TS_POLLING;
334                 smp_mb__after_clear_bit();
335                 if (need_resched()) {
336                         current_thread_info()->status |= TS_POLLING;
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
373 #ifdef CONFIG_GENERIC_TIME
374                 /* TSC halts in C2, so notify users */
375                 mark_tsc_unstable();
376 #endif
377                 /* Re-enable interrupts */
378                 local_irq_enable();
379                 current_thread_info()->status |= TS_POLLING;
380                 /* Compute time (ticks) that we were actually asleep */
381                 sleep_ticks =
382                     ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
383                 break;
384
385         case ACPI_STATE_C3:
386
387                 if (pr->flags.bm_check) {
388                         if (atomic_inc_return(&c3_cpu_count) ==
389                             num_online_cpus()) {
390                                 /*
391                                  * All CPUs are trying to go to C3
392                                  * Disable bus master arbitration
393                                  */
394                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
395                                                   ACPI_MTX_DO_NOT_LOCK);
396                         }
397                 } else {
398                         /* SMP with no shared cache... Invalidate cache  */
399                         ACPI_FLUSH_CPU_CACHE();
400                 }
401
402                 /* Get start time (ticks) */
403                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
404                 /* Invoke C3 */
405                 inb(cx->address);
406                 /* Dummy op - must do something useless after P_LVL3 read */
407                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
408                 /* Get end time (ticks) */
409                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
410                 if (pr->flags.bm_check) {
411                         /* Enable bus master arbitration */
412                         atomic_dec(&c3_cpu_count);
413                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
414                                           ACPI_MTX_DO_NOT_LOCK);
415                 }
416
417 #ifdef CONFIG_GENERIC_TIME
418                 /* TSC halts in C3, so notify users */
419                 mark_tsc_unstable();
420 #endif
421                 /* Re-enable interrupts */
422                 local_irq_enable();
423                 current_thread_info()->status |= TS_POLLING;
424                 /* Compute time (ticks) that we were actually asleep */
425                 sleep_ticks =
426                     ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
427                 break;
428
429         default:
430                 local_irq_enable();
431                 return;
432         }
433
434         next_state = pr->power.state;
435
436 #ifdef CONFIG_HOTPLUG_CPU
437         /* Don't do promotion/demotion */
438         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
439             !pr->flags.has_cst && !acpi_fadt.plvl2_up) {
440                 next_state = cx;
441                 goto end;
442         }
443 #endif
444
445         /*
446          * Promotion?
447          * ----------
448          * Track the number of longs (time asleep is greater than threshold)
449          * and promote when the count threshold is reached.  Note that bus
450          * mastering activity may prevent promotions.
451          * Do not promote above max_cstate.
452          */
453         if (cx->promotion.state &&
454             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
455                 if (sleep_ticks > cx->promotion.threshold.ticks) {
456                         cx->promotion.count++;
457                         cx->demotion.count = 0;
458                         if (cx->promotion.count >=
459                             cx->promotion.threshold.count) {
460                                 if (pr->flags.bm_check) {
461                                         if (!
462                                             (pr->power.bm_activity & cx->
463                                              promotion.threshold.bm)) {
464                                                 next_state =
465                                                     cx->promotion.state;
466                                                 goto end;
467                                         }
468                                 } else {
469                                         next_state = cx->promotion.state;
470                                         goto end;
471                                 }
472                         }
473                 }
474         }
475
476         /*
477          * Demotion?
478          * ---------
479          * Track the number of shorts (time asleep is less than time threshold)
480          * and demote when the usage threshold is reached.
481          */
482         if (cx->demotion.state) {
483                 if (sleep_ticks < cx->demotion.threshold.ticks) {
484                         cx->demotion.count++;
485                         cx->promotion.count = 0;
486                         if (cx->demotion.count >= cx->demotion.threshold.count) {
487                                 next_state = cx->demotion.state;
488                                 goto end;
489                         }
490                 }
491         }
492
493       end:
494         /*
495          * Demote if current state exceeds max_cstate
496          */
497         if ((pr->power.state - pr->power.states) > max_cstate) {
498                 if (cx->demotion.state)
499                         next_state = cx->demotion.state;
500         }
501
502         /*
503          * New Cx State?
504          * -------------
505          * If we're going to start using a new Cx state we must clean up
506          * from the previous and prepare to use the new.
507          */
508         if (next_state != pr->power.state)
509                 acpi_processor_power_activate(pr, next_state);
510 }
511
512 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
513 {
514         unsigned int i;
515         unsigned int state_is_set = 0;
516         struct acpi_processor_cx *lower = NULL;
517         struct acpi_processor_cx *higher = NULL;
518         struct acpi_processor_cx *cx;
519
520         ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
521
522         if (!pr)
523                 return_VALUE(-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_VALUE(-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_VALUE(0);
587 }
588
589 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
590 {
591         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
592
593         if (!pr)
594                 return_VALUE(-EINVAL);
595
596         if (!pr->pblk)
597                 return_VALUE(-ENODEV);
598
599         /* if info is obtained from pblk/fadt, type equals state */
600         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
601         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
602
603 #ifndef CONFIG_HOTPLUG_CPU
604         /*
605          * Check for P_LVL2_UP flag before entering C2 and above on
606          * an SMP system. 
607          */
608         if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up)
609                 return_VALUE(-ENODEV);
610 #endif
611
612         /* determine C2 and C3 address from pblk */
613         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
614         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
615
616         /* determine latencies from FADT */
617         pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
618         pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
619
620         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
621                           "lvl2[0x%08x] lvl3[0x%08x]\n",
622                           pr->power.states[ACPI_STATE_C2].address,
623                           pr->power.states[ACPI_STATE_C3].address));
624
625         return_VALUE(0);
626 }
627
628 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
629 {
630         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
631
632         /* Zero initialize all the C-states info. */
633         memset(pr->power.states, 0, sizeof(pr->power.states));
634
635         /* set the first C-State to C1 */
636         pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
637
638         /* the C0 state only exists as a filler in our array,
639          * and all processors need to support C1 */
640         pr->power.states[ACPI_STATE_C0].valid = 1;
641         pr->power.states[ACPI_STATE_C1].valid = 1;
642
643         return_VALUE(0);
644 }
645
646 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
647 {
648         acpi_status status = 0;
649         acpi_integer count;
650         int current_count;
651         int i;
652         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
653         union acpi_object *cst;
654
655         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
656
657         if (nocst)
658                 return_VALUE(-ENODEV);
659
660         current_count = 1;
661
662         /* Zero initialize C2 onwards and prepare for fresh CST lookup */
663         for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++)
664                 memset(&(pr->power.states[i]), 0, 
665                                 sizeof(struct acpi_processor_cx));
666
667         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
668         if (ACPI_FAILURE(status)) {
669                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
670                 return_VALUE(-ENODEV);
671         }
672
673         cst = (union acpi_object *)buffer.pointer;
674
675         /* There must be at least 2 elements */
676         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
677                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
678                                   "not enough elements in _CST\n"));
679                 status = -EFAULT;
680                 goto end;
681         }
682
683         count = cst->package.elements[0].integer.value;
684
685         /* Validate number of power states. */
686         if (count < 1 || count != cst->package.count - 1) {
687                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
688                                   "count given by _CST is not valid\n"));
689                 status = -EFAULT;
690                 goto end;
691         }
692
693         /* Tell driver that at least _CST is supported. */
694         pr->flags.has_cst = 1;
695
696         for (i = 1; i <= count; i++) {
697                 union acpi_object *element;
698                 union acpi_object *obj;
699                 struct acpi_power_register *reg;
700                 struct acpi_processor_cx cx;
701
702                 memset(&cx, 0, sizeof(cx));
703
704                 element = (union acpi_object *)&(cst->package.elements[i]);
705                 if (element->type != ACPI_TYPE_PACKAGE)
706                         continue;
707
708                 if (element->package.count != 4)
709                         continue;
710
711                 obj = (union acpi_object *)&(element->package.elements[0]);
712
713                 if (obj->type != ACPI_TYPE_BUFFER)
714                         continue;
715
716                 reg = (struct acpi_power_register *)obj->buffer.pointer;
717
718                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
719                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
720                         continue;
721
722                 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
723                     0 : reg->address;
724
725                 /* There should be an easy way to extract an integer... */
726                 obj = (union acpi_object *)&(element->package.elements[1]);
727                 if (obj->type != ACPI_TYPE_INTEGER)
728                         continue;
729
730                 cx.type = obj->integer.value;
731
732                 if ((cx.type != ACPI_STATE_C1) &&
733                     (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
734                         continue;
735
736                 if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3))
737                         continue;
738
739                 obj = (union acpi_object *)&(element->package.elements[2]);
740                 if (obj->type != ACPI_TYPE_INTEGER)
741                         continue;
742
743                 cx.latency = obj->integer.value;
744
745                 obj = (union acpi_object *)&(element->package.elements[3]);
746                 if (obj->type != ACPI_TYPE_INTEGER)
747                         continue;
748
749                 cx.power = obj->integer.value;
750
751                 current_count++;
752                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
753
754                 /*
755                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
756                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
757                  */
758                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
759                         printk(KERN_WARNING
760                                "Limiting number of power states to max (%d)\n",
761                                ACPI_PROCESSOR_MAX_POWER);
762                         printk(KERN_WARNING
763                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
764                         break;
765                 }
766         }
767
768         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
769                           current_count));
770
771         /* Validate number of power states discovered */
772         if (current_count < 2)
773                 status = -EFAULT;
774
775       end:
776         acpi_os_free(buffer.pointer);
777
778         return_VALUE(status);
779 }
780
781 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
782 {
783         ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
784
785         if (!cx->address)
786                 return_VOID;
787
788         /*
789          * C2 latency must be less than or equal to 100
790          * microseconds.
791          */
792         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
793                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
794                                   "latency too large [%d]\n", cx->latency));
795                 return_VOID;
796         }
797
798         /*
799          * Otherwise we've met all of our C2 requirements.
800          * Normalize the C2 latency to expidite policy
801          */
802         cx->valid = 1;
803         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
804
805         return_VOID;
806 }
807
808 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
809                                            struct acpi_processor_cx *cx)
810 {
811         static int bm_check_flag;
812
813         ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
814
815         if (!cx->address)
816                 return_VOID;
817
818         /*
819          * C3 latency must be less than or equal to 1000
820          * microseconds.
821          */
822         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
823                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
824                                   "latency too large [%d]\n", cx->latency));
825                 return_VOID;
826         }
827
828         /*
829          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
830          * DMA transfers are used by any ISA device to avoid livelock.
831          * Note that we could disable Type-F DMA (as recommended by
832          * the erratum), but this is known to disrupt certain ISA
833          * devices thus we take the conservative approach.
834          */
835         else if (errata.piix4.fdma) {
836                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
837                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
838                 return_VOID;
839         }
840
841         /* All the logic here assumes flags.bm_check is same across all CPUs */
842         if (!bm_check_flag) {
843                 /* Determine whether bm_check is needed based on CPU  */
844                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
845                 bm_check_flag = pr->flags.bm_check;
846         } else {
847                 pr->flags.bm_check = bm_check_flag;
848         }
849
850         if (pr->flags.bm_check) {
851                 /* bus mastering control is necessary */
852                 if (!pr->flags.bm_control) {
853                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
854                                           "C3 support requires bus mastering control\n"));
855                         return_VOID;
856                 }
857         } else {
858                 /*
859                  * WBINVD should be set in fadt, for C3 state to be
860                  * supported on when bm_check is not required.
861                  */
862                 if (acpi_fadt.wb_invd != 1) {
863                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
864                                           "Cache invalidation should work properly"
865                                           " for C3 to be enabled on SMP systems\n"));
866                         return_VOID;
867                 }
868                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
869                                   0, ACPI_MTX_DO_NOT_LOCK);
870         }
871
872         /*
873          * Otherwise we've met all of our C3 requirements.
874          * Normalize the C3 latency to expidite policy.  Enable
875          * checking of bus mastering status (bm_check) so we can
876          * use this in our C3 policy
877          */
878         cx->valid = 1;
879         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
880
881         return_VOID;
882 }
883
884 static int acpi_processor_power_verify(struct acpi_processor *pr)
885 {
886         unsigned int i;
887         unsigned int working = 0;
888
889 #ifdef ARCH_APICTIMER_STOPS_ON_C3
890         int timer_broadcast = 0;
891         cpumask_t mask = cpumask_of_cpu(pr->id);
892         on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
893 #endif
894
895         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
896                 struct acpi_processor_cx *cx = &pr->power.states[i];
897
898                 switch (cx->type) {
899                 case ACPI_STATE_C1:
900                         cx->valid = 1;
901                         break;
902
903                 case ACPI_STATE_C2:
904                         acpi_processor_power_verify_c2(cx);
905 #ifdef ARCH_APICTIMER_STOPS_ON_C3
906                         /* Some AMD systems fake C3 as C2, but still
907                            have timer troubles */
908                         if (cx->valid && 
909                                 boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
910                                 timer_broadcast++;
911 #endif
912                         break;
913
914                 case ACPI_STATE_C3:
915                         acpi_processor_power_verify_c3(pr, cx);
916 #ifdef ARCH_APICTIMER_STOPS_ON_C3
917                         if (cx->valid)
918                                 timer_broadcast++;
919 #endif
920                         break;
921                 }
922
923                 if (cx->valid)
924                         working++;
925         }
926
927 #ifdef ARCH_APICTIMER_STOPS_ON_C3
928         if (timer_broadcast)
929                 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
930 #endif
931
932         return (working);
933 }
934
935 static int acpi_processor_get_power_info(struct acpi_processor *pr)
936 {
937         unsigned int i;
938         int result;
939
940         ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
941
942         /* NOTE: the idle thread may not be running while calling
943          * this function */
944
945         /* Adding C1 state */
946         acpi_processor_get_power_info_default_c1(pr);
947         result = acpi_processor_get_power_info_cst(pr);
948         if (result == -ENODEV)
949                 acpi_processor_get_power_info_fadt(pr);
950
951         pr->power.count = acpi_processor_power_verify(pr);
952
953         /*
954          * Set Default Policy
955          * ------------------
956          * Now that we know which states are supported, set the default
957          * policy.  Note that this policy can be changed dynamically
958          * (e.g. encourage deeper sleeps to conserve battery life when
959          * not on AC).
960          */
961         result = acpi_processor_set_power_policy(pr);
962         if (result)
963                 return_VALUE(result);
964
965         /*
966          * if one state of type C2 or C3 is available, mark this
967          * CPU as being "idle manageable"
968          */
969         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
970                 if (pr->power.states[i].valid) {
971                         pr->power.count = i;
972                         if (pr->power.states[i].type >= ACPI_STATE_C2)
973                                 pr->flags.power = 1;
974                 }
975         }
976
977         return_VALUE(0);
978 }
979
980 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
981 {
982         int result = 0;
983
984         ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
985
986         if (!pr)
987                 return_VALUE(-EINVAL);
988
989         if (nocst) {
990                 return_VALUE(-ENODEV);
991         }
992
993         if (!pr->flags.power_setup_done)
994                 return_VALUE(-ENODEV);
995
996         /* Fall back to the default idle loop */
997         pm_idle = pm_idle_save;
998         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
999
1000         pr->flags.power = 0;
1001         result = acpi_processor_get_power_info(pr);
1002         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1003                 pm_idle = acpi_processor_idle;
1004
1005         return_VALUE(result);
1006 }
1007
1008 /* proc interface */
1009
1010 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1011 {
1012         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
1013         unsigned int i;
1014
1015         ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
1016
1017         if (!pr)
1018                 goto end;
1019
1020         seq_printf(seq, "active state:            C%zd\n"
1021                    "max_cstate:              C%d\n"
1022                    "bus master activity:     %08x\n",
1023                    pr->power.state ? pr->power.state - pr->power.states : 0,
1024                    max_cstate, (unsigned)pr->power.bm_activity);
1025
1026         seq_puts(seq, "states:\n");
1027
1028         for (i = 1; i <= pr->power.count; i++) {
1029                 seq_printf(seq, "   %cC%d:                  ",
1030                            (&pr->power.states[i] ==
1031                             pr->power.state ? '*' : ' '), i);
1032
1033                 if (!pr->power.states[i].valid) {
1034                         seq_puts(seq, "<not supported>\n");
1035                         continue;
1036                 }
1037
1038                 switch (pr->power.states[i].type) {
1039                 case ACPI_STATE_C1:
1040                         seq_printf(seq, "type[C1] ");
1041                         break;
1042                 case ACPI_STATE_C2:
1043                         seq_printf(seq, "type[C2] ");
1044                         break;
1045                 case ACPI_STATE_C3:
1046                         seq_printf(seq, "type[C3] ");
1047                         break;
1048                 default:
1049                         seq_printf(seq, "type[--] ");
1050                         break;
1051                 }
1052
1053                 if (pr->power.states[i].promotion.state)
1054                         seq_printf(seq, "promotion[C%zd] ",
1055                                    (pr->power.states[i].promotion.state -
1056                                     pr->power.states));
1057                 else
1058                         seq_puts(seq, "promotion[--] ");
1059
1060                 if (pr->power.states[i].demotion.state)
1061                         seq_printf(seq, "demotion[C%zd] ",
1062                                    (pr->power.states[i].demotion.state -
1063                                     pr->power.states));
1064                 else
1065                         seq_puts(seq, "demotion[--] ");
1066
1067                 seq_printf(seq, "latency[%03d] usage[%08d]\n",
1068                            pr->power.states[i].latency,
1069                            pr->power.states[i].usage);
1070         }
1071
1072       end:
1073         return_VALUE(0);
1074 }
1075
1076 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1077 {
1078         return single_open(file, acpi_processor_power_seq_show,
1079                            PDE(inode)->data);
1080 }
1081
1082 static struct file_operations acpi_processor_power_fops = {
1083         .open = acpi_processor_power_open_fs,
1084         .read = seq_read,
1085         .llseek = seq_lseek,
1086         .release = single_release,
1087 };
1088
1089 int acpi_processor_power_init(struct acpi_processor *pr,
1090                               struct acpi_device *device)
1091 {
1092         acpi_status status = 0;
1093         static int first_run;
1094         struct proc_dir_entry *entry = NULL;
1095         unsigned int i;
1096
1097         ACPI_FUNCTION_TRACE("acpi_processor_power_init");
1098
1099         if (!first_run) {
1100                 dmi_check_system(processor_power_dmi_table);
1101                 if (max_cstate < ACPI_C_STATES_MAX)
1102                         printk(KERN_NOTICE
1103                                "ACPI: processor limited to max C-state %d\n",
1104                                max_cstate);
1105                 first_run++;
1106         }
1107
1108         if (!pr)
1109                 return_VALUE(-EINVAL);
1110
1111         if (acpi_fadt.cst_cnt && !nocst) {
1112                 status =
1113                     acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1114                 if (ACPI_FAILURE(status)) {
1115                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1116                                           "Notifying BIOS of _CST ability failed\n"));
1117                 }
1118         }
1119
1120         acpi_processor_get_power_info(pr);
1121
1122         /*
1123          * Install the idle handler if processor power management is supported.
1124          * Note that we use previously set idle handler will be used on
1125          * platforms that only support C1.
1126          */
1127         if ((pr->flags.power) && (!boot_option_idle_override)) {
1128                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1129                 for (i = 1; i <= pr->power.count; i++)
1130                         if (pr->power.states[i].valid)
1131                                 printk(" C%d[C%d]", i,
1132                                        pr->power.states[i].type);
1133                 printk(")\n");
1134
1135                 if (pr->id == 0) {
1136                         pm_idle_save = pm_idle;
1137                         pm_idle = acpi_processor_idle;
1138                 }
1139         }
1140
1141         /* 'power' [R] */
1142         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1143                                   S_IRUGO, acpi_device_dir(device));
1144         if (!entry)
1145                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
1146                                   "Unable to create '%s' fs entry\n",
1147                                   ACPI_PROCESSOR_FILE_POWER));
1148         else {
1149                 entry->proc_fops = &acpi_processor_power_fops;
1150                 entry->data = acpi_driver_data(device);
1151                 entry->owner = THIS_MODULE;
1152         }
1153
1154         pr->flags.power_setup_done = 1;
1155
1156         return_VALUE(0);
1157 }
1158
1159 int acpi_processor_power_exit(struct acpi_processor *pr,
1160                               struct acpi_device *device)
1161 {
1162         ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
1163
1164         pr->flags.power_setup_done = 0;
1165
1166         if (acpi_device_dir(device))
1167                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1168                                   acpi_device_dir(device));
1169
1170         /* Unregister the idle handler when processor #0 is removed. */
1171         if (pr->id == 0) {
1172                 pm_idle = pm_idle_save;
1173
1174                 /*
1175                  * We are about to unload the current idle thread pm callback
1176                  * (pm_idle), Wait for all processors to update cached/local
1177                  * copies of pm_idle before proceeding.
1178                  */
1179                 cpu_idle_wait();
1180         }
1181
1182         return_VALUE(0);
1183 }