ACPICA: minimal patch to integrate new tables into Linux
[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, 2005 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/cpufreq.h>
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/moduleparam.h>
40 #include <linux/sched.h>        /* need_resched() */
41 #include <linux/latency.h>
42
43 #include <asm/io.h>
44 #include <asm/uaccess.h>
45
46 #include <acpi/acpi_bus.h>
47 #include <acpi/processor.h>
48
49 #define ACPI_PROCESSOR_COMPONENT        0x01000000
50 #define ACPI_PROCESSOR_CLASS            "processor"
51 #define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
52 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
53 ACPI_MODULE_NAME("acpi_processor")
54 #define ACPI_PROCESSOR_FILE_POWER       "power"
55 #define US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
56 #define C2_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
57 #define C3_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
58 static void (*pm_idle_save) (void) __read_mostly;
59 module_param(max_cstate, uint, 0644);
60
61 static unsigned int nocst __read_mostly;
62 module_param(nocst, uint, 0000);
63
64 /*
65  * bm_history -- bit-mask with a bit per jiffy of bus-master activity
66  * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
67  * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
68  * 100 HZ: 0x0000000F: 4 jiffies = 40ms
69  * reduce history for more aggressive entry into C3
70  */
71 static unsigned int bm_history __read_mostly =
72     (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
73 module_param(bm_history, uint, 0644);
74 /* --------------------------------------------------------------------------
75                                 Power Management
76    -------------------------------------------------------------------------- */
77
78 /*
79  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
80  * For now disable this. Probably a bug somewhere else.
81  *
82  * To skip this limit, boot/load with a large max_cstate limit.
83  */
84 static int set_max_cstate(struct dmi_system_id *id)
85 {
86         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
87                 return 0;
88
89         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
90                " Override with \"processor.max_cstate=%d\"\n", id->ident,
91                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
92
93         max_cstate = (long)id->driver_data;
94
95         return 0;
96 }
97
98 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
99    callers to only run once -AK */
100 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
101         { set_max_cstate, "IBM ThinkPad R40e", {
102           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
103           DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
104         { set_max_cstate, "IBM ThinkPad R40e", {
105           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
106           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
107         { set_max_cstate, "IBM ThinkPad R40e", {
108           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
109           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
110         { set_max_cstate, "IBM ThinkPad R40e", {
111           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
112           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
113         { set_max_cstate, "IBM ThinkPad R40e", {
114           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
115           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
116         { set_max_cstate, "IBM ThinkPad R40e", {
117           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
118           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
119         { set_max_cstate, "IBM ThinkPad R40e", {
120           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
121           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
122         { set_max_cstate, "IBM ThinkPad R40e", {
123           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
124           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
125         { set_max_cstate, "IBM ThinkPad R40e", {
126           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
127           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
128         { set_max_cstate, "IBM ThinkPad R40e", {
129           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
130           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
131         { set_max_cstate, "IBM ThinkPad R40e", {
132           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
133           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
134         { set_max_cstate, "IBM ThinkPad R40e", {
135           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
136           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
137         { set_max_cstate, "IBM ThinkPad R40e", {
138           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
139           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
140         { set_max_cstate, "IBM ThinkPad R40e", {
141           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
142           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
143         { set_max_cstate, "IBM ThinkPad R40e", {
144           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
145           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
146         { set_max_cstate, "IBM ThinkPad R40e", {
147           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
148           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
149         { set_max_cstate, "Medion 41700", {
150           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
151           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
152         { set_max_cstate, "Clevo 5600D", {
153           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
154           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
155          (void *)2},
156         {},
157 };
158
159 static inline u32 ticks_elapsed(u32 t1, u32 t2)
160 {
161         if (t2 >= t1)
162                 return (t2 - t1);
163         else if (!(acpi_fadt.flags & ACPI_FADT_32BIT_TIMER))
164                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
165         else
166                 return ((0xFFFFFFFF - t1) + t2);
167 }
168
169 static void
170 acpi_processor_power_activate(struct acpi_processor *pr,
171                               struct acpi_processor_cx *new)
172 {
173         struct acpi_processor_cx *old;
174
175         if (!pr || !new)
176                 return;
177
178         old = pr->power.state;
179
180         if (old)
181                 old->promotion.count = 0;
182         new->demotion.count = 0;
183
184         /* Cleanup from old state. */
185         if (old) {
186                 switch (old->type) {
187                 case ACPI_STATE_C3:
188                         /* Disable bus master reload */
189                         if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
190                                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0,
191                                                   ACPI_MTX_DO_NOT_LOCK);
192                         break;
193                 }
194         }
195
196         /* Prepare to use new state. */
197         switch (new->type) {
198         case ACPI_STATE_C3:
199                 /* Enable bus master reload */
200                 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
201                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1,
202                                           ACPI_MTX_DO_NOT_LOCK);
203                 break;
204         }
205
206         pr->power.state = new;
207
208         return;
209 }
210
211 static void acpi_safe_halt(void)
212 {
213         current_thread_info()->status &= ~TS_POLLING;
214         /*
215          * TS_POLLING-cleared state must be visible before we
216          * test NEED_RESCHED:
217          */
218         smp_mb();
219         if (!need_resched())
220                 safe_halt();
221         current_thread_info()->status |= TS_POLLING;
222 }
223
224 static atomic_t c3_cpu_count;
225
226 /* Common C-state entry for C2, C3, .. */
227 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
228 {
229         if (cstate->space_id == ACPI_CSTATE_FFH) {
230                 /* Call into architectural FFH based C-state */
231                 acpi_processor_ffh_cstate_enter(cstate);
232         } else {
233                 int unused;
234                 /* IO port based C-state */
235                 inb(cstate->address);
236                 /* Dummy wait op - must do something useless after P_LVL2 read
237                    because chipsets cannot guarantee that STPCLK# signal
238                    gets asserted in time to freeze execution properly. */
239                 unused = inl(acpi_fadt.xpm_timer_block.address);
240         }
241 }
242
243 static void acpi_processor_idle(void)
244 {
245         struct acpi_processor *pr = NULL;
246         struct acpi_processor_cx *cx = NULL;
247         struct acpi_processor_cx *next_state = NULL;
248         int sleep_ticks = 0;
249         u32 t1, t2 = 0;
250
251         pr = processors[smp_processor_id()];
252         if (!pr)
253                 return;
254
255         /*
256          * Interrupts must be disabled during bus mastering calculations and
257          * for C2/C3 transitions.
258          */
259         local_irq_disable();
260
261         /*
262          * Check whether we truly need to go idle, or should
263          * reschedule:
264          */
265         if (unlikely(need_resched())) {
266                 local_irq_enable();
267                 return;
268         }
269
270         cx = pr->power.state;
271         if (!cx) {
272                 if (pm_idle_save)
273                         pm_idle_save();
274                 else
275                         acpi_safe_halt();
276                 return;
277         }
278
279         /*
280          * Check BM Activity
281          * -----------------
282          * Check for bus mastering activity (if required), record, and check
283          * for demotion.
284          */
285         if (pr->flags.bm_check) {
286                 u32 bm_status = 0;
287                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
288
289                 if (diff > 31)
290                         diff = 31;
291
292                 pr->power.bm_activity <<= diff;
293
294                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
295                                   &bm_status, ACPI_MTX_DO_NOT_LOCK);
296                 if (bm_status) {
297                         pr->power.bm_activity |= 0x1;
298                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
299                                           1, ACPI_MTX_DO_NOT_LOCK);
300                 }
301                 /*
302                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
303                  * the true state of bus mastering activity; forcing us to
304                  * manually check the BMIDEA bit of each IDE channel.
305                  */
306                 else if (errata.piix4.bmisx) {
307                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
308                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
309                                 pr->power.bm_activity |= 0x1;
310                 }
311
312                 pr->power.bm_check_timestamp = jiffies;
313
314                 /*
315                  * If bus mastering is or was active this jiffy, demote
316                  * to avoid a faulty transition.  Note that the processor
317                  * won't enter a low-power state during this call (to this
318                  * function) but should upon the next.
319                  *
320                  * TBD: A better policy might be to fallback to the demotion
321                  *      state (use it for this quantum only) istead of
322                  *      demoting -- and rely on duration as our sole demotion
323                  *      qualification.  This may, however, introduce DMA
324                  *      issues (e.g. floppy DMA transfer overrun/underrun).
325                  */
326                 if ((pr->power.bm_activity & 0x1) &&
327                     cx->demotion.threshold.bm) {
328                         local_irq_enable();
329                         next_state = cx->demotion.state;
330                         goto end;
331                 }
332         }
333
334 #ifdef CONFIG_HOTPLUG_CPU
335         /*
336          * Check for P_LVL2_UP flag before entering C2 and above on
337          * an SMP system. We do it here instead of doing it at _CST/P_LVL
338          * detection phase, to work cleanly with logical CPU hotplug.
339          */
340         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
341             !pr->flags.has_cst && !(acpi_fadt.flags & ACPI_FADT_C2_MP_SUPPORTED))
342                 cx = &pr->power.states[ACPI_STATE_C1];
343 #endif
344
345         /*
346          * Sleep:
347          * ------
348          * Invoke the current Cx state to put the processor to sleep.
349          */
350         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
351                 current_thread_info()->status &= ~TS_POLLING;
352                 /*
353                  * TS_POLLING-cleared state must be visible before we
354                  * test NEED_RESCHED:
355                  */
356                 smp_mb();
357                 if (need_resched()) {
358                         current_thread_info()->status |= TS_POLLING;
359                         local_irq_enable();
360                         return;
361                 }
362         }
363
364         switch (cx->type) {
365
366         case ACPI_STATE_C1:
367                 /*
368                  * Invoke C1.
369                  * Use the appropriate idle routine, the one that would
370                  * be used without acpi C-states.
371                  */
372                 if (pm_idle_save)
373                         pm_idle_save();
374                 else
375                         acpi_safe_halt();
376
377                 /*
378                  * TBD: Can't get time duration while in C1, as resumes
379                  *      go to an ISR rather than here.  Need to instrument
380                  *      base interrupt handler.
381                  */
382                 sleep_ticks = 0xFFFFFFFF;
383                 break;
384
385         case ACPI_STATE_C2:
386                 /* Get start time (ticks) */
387                 t1 = inl(acpi_fadt.xpm_timer_block.address);
388                 /* Invoke C2 */
389                 acpi_cstate_enter(cx);
390                 /* Get end time (ticks) */
391                 t2 = inl(acpi_fadt.xpm_timer_block.address);
392
393 #ifdef CONFIG_GENERIC_TIME
394                 /* TSC halts in C2, so notify users */
395                 mark_tsc_unstable();
396 #endif
397                 /* Re-enable interrupts */
398                 local_irq_enable();
399                 current_thread_info()->status |= TS_POLLING;
400                 /* Compute time (ticks) that we were actually asleep */
401                 sleep_ticks =
402                     ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
403                 break;
404
405         case ACPI_STATE_C3:
406
407                 if (pr->flags.bm_check) {
408                         if (atomic_inc_return(&c3_cpu_count) ==
409                             num_online_cpus()) {
410                                 /*
411                                  * All CPUs are trying to go to C3
412                                  * Disable bus master arbitration
413                                  */
414                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
415                                                   ACPI_MTX_DO_NOT_LOCK);
416                         }
417                 } else {
418                         /* SMP with no shared cache... Invalidate cache  */
419                         ACPI_FLUSH_CPU_CACHE();
420                 }
421
422                 /* Get start time (ticks) */
423                 t1 = inl(acpi_fadt.xpm_timer_block.address);
424                 /* Invoke C3 */
425                 acpi_cstate_enter(cx);
426                 /* Get end time (ticks) */
427                 t2 = inl(acpi_fadt.xpm_timer_block.address);
428                 if (pr->flags.bm_check) {
429                         /* Enable bus master arbitration */
430                         atomic_dec(&c3_cpu_count);
431                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
432                                           ACPI_MTX_DO_NOT_LOCK);
433                 }
434
435 #ifdef CONFIG_GENERIC_TIME
436                 /* TSC halts in C3, so notify users */
437                 mark_tsc_unstable();
438 #endif
439                 /* Re-enable interrupts */
440                 local_irq_enable();
441                 current_thread_info()->status |= TS_POLLING;
442                 /* Compute time (ticks) that we were actually asleep */
443                 sleep_ticks =
444                     ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
445                 break;
446
447         default:
448                 local_irq_enable();
449                 return;
450         }
451         cx->usage++;
452         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
453                 cx->time += sleep_ticks;
454
455         next_state = pr->power.state;
456
457 #ifdef CONFIG_HOTPLUG_CPU
458         /* Don't do promotion/demotion */
459         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
460             !pr->flags.has_cst && !(acpi_fadt.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
461                 next_state = cx;
462                 goto end;
463         }
464 #endif
465
466         /*
467          * Promotion?
468          * ----------
469          * Track the number of longs (time asleep is greater than threshold)
470          * and promote when the count threshold is reached.  Note that bus
471          * mastering activity may prevent promotions.
472          * Do not promote above max_cstate.
473          */
474         if (cx->promotion.state &&
475             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
476                 if (sleep_ticks > cx->promotion.threshold.ticks &&
477                   cx->promotion.state->latency <= system_latency_constraint()) {
478                         cx->promotion.count++;
479                         cx->demotion.count = 0;
480                         if (cx->promotion.count >=
481                             cx->promotion.threshold.count) {
482                                 if (pr->flags.bm_check) {
483                                         if (!
484                                             (pr->power.bm_activity & cx->
485                                              promotion.threshold.bm)) {
486                                                 next_state =
487                                                     cx->promotion.state;
488                                                 goto end;
489                                         }
490                                 } else {
491                                         next_state = cx->promotion.state;
492                                         goto end;
493                                 }
494                         }
495                 }
496         }
497
498         /*
499          * Demotion?
500          * ---------
501          * Track the number of shorts (time asleep is less than time threshold)
502          * and demote when the usage threshold is reached.
503          */
504         if (cx->demotion.state) {
505                 if (sleep_ticks < cx->demotion.threshold.ticks) {
506                         cx->demotion.count++;
507                         cx->promotion.count = 0;
508                         if (cx->demotion.count >= cx->demotion.threshold.count) {
509                                 next_state = cx->demotion.state;
510                                 goto end;
511                         }
512                 }
513         }
514
515       end:
516         /*
517          * Demote if current state exceeds max_cstate
518          * or if the latency of the current state is unacceptable
519          */
520         if ((pr->power.state - pr->power.states) > max_cstate ||
521                 pr->power.state->latency > system_latency_constraint()) {
522                 if (cx->demotion.state)
523                         next_state = cx->demotion.state;
524         }
525
526         /*
527          * New Cx State?
528          * -------------
529          * If we're going to start using a new Cx state we must clean up
530          * from the previous and prepare to use the new.
531          */
532         if (next_state != pr->power.state)
533                 acpi_processor_power_activate(pr, next_state);
534 }
535
536 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
537 {
538         unsigned int i;
539         unsigned int state_is_set = 0;
540         struct acpi_processor_cx *lower = NULL;
541         struct acpi_processor_cx *higher = NULL;
542         struct acpi_processor_cx *cx;
543
544
545         if (!pr)
546                 return -EINVAL;
547
548         /*
549          * This function sets the default Cx state policy (OS idle handler).
550          * Our scheme is to promote quickly to C2 but more conservatively
551          * to C3.  We're favoring C2  for its characteristics of low latency
552          * (quick response), good power savings, and ability to allow bus
553          * mastering activity.  Note that the Cx state policy is completely
554          * customizable and can be altered dynamically.
555          */
556
557         /* startup state */
558         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
559                 cx = &pr->power.states[i];
560                 if (!cx->valid)
561                         continue;
562
563                 if (!state_is_set)
564                         pr->power.state = cx;
565                 state_is_set++;
566                 break;
567         }
568
569         if (!state_is_set)
570                 return -ENODEV;
571
572         /* demotion */
573         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
574                 cx = &pr->power.states[i];
575                 if (!cx->valid)
576                         continue;
577
578                 if (lower) {
579                         cx->demotion.state = lower;
580                         cx->demotion.threshold.ticks = cx->latency_ticks;
581                         cx->demotion.threshold.count = 1;
582                         if (cx->type == ACPI_STATE_C3)
583                                 cx->demotion.threshold.bm = bm_history;
584                 }
585
586                 lower = cx;
587         }
588
589         /* promotion */
590         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
591                 cx = &pr->power.states[i];
592                 if (!cx->valid)
593                         continue;
594
595                 if (higher) {
596                         cx->promotion.state = higher;
597                         cx->promotion.threshold.ticks = cx->latency_ticks;
598                         if (cx->type >= ACPI_STATE_C2)
599                                 cx->promotion.threshold.count = 4;
600                         else
601                                 cx->promotion.threshold.count = 10;
602                         if (higher->type == ACPI_STATE_C3)
603                                 cx->promotion.threshold.bm = bm_history;
604                 }
605
606                 higher = cx;
607         }
608
609         return 0;
610 }
611
612 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
613 {
614
615         if (!pr)
616                 return -EINVAL;
617
618         if (!pr->pblk)
619                 return -ENODEV;
620
621         /* if info is obtained from pblk/fadt, type equals state */
622         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
623         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
624
625 #ifndef CONFIG_HOTPLUG_CPU
626         /*
627          * Check for P_LVL2_UP flag before entering C2 and above on
628          * an SMP system. 
629          */
630         if ((num_online_cpus() > 1) &&
631             !(acpi_fadt.flags & ACPI_FADT_C2_MP_SUPPORTED))
632                 return -ENODEV;
633 #endif
634
635         /* determine C2 and C3 address from pblk */
636         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
637         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
638
639         /* determine latencies from FADT */
640         pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.C2latency;
641         pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.C3latency;
642
643         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
644                           "lvl2[0x%08x] lvl3[0x%08x]\n",
645                           pr->power.states[ACPI_STATE_C2].address,
646                           pr->power.states[ACPI_STATE_C3].address));
647
648         return 0;
649 }
650
651 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
652 {
653         if (!pr->power.states[ACPI_STATE_C1].valid) {
654                 /* set the first C-State to C1 */
655                 /* all processors need to support C1 */
656                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
657                 pr->power.states[ACPI_STATE_C1].valid = 1;
658         }
659         /* the C0 state only exists as a filler in our array */
660         pr->power.states[ACPI_STATE_C0].valid = 1;
661         return 0;
662 }
663
664 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
665 {
666         acpi_status status = 0;
667         acpi_integer count;
668         int current_count;
669         int i;
670         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
671         union acpi_object *cst;
672
673
674         if (nocst)
675                 return -ENODEV;
676
677         current_count = 0;
678
679         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
680         if (ACPI_FAILURE(status)) {
681                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
682                 return -ENODEV;
683         }
684
685         cst = buffer.pointer;
686
687         /* There must be at least 2 elements */
688         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
689                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
690                 status = -EFAULT;
691                 goto end;
692         }
693
694         count = cst->package.elements[0].integer.value;
695
696         /* Validate number of power states. */
697         if (count < 1 || count != cst->package.count - 1) {
698                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
699                 status = -EFAULT;
700                 goto end;
701         }
702
703         /* Tell driver that at least _CST is supported. */
704         pr->flags.has_cst = 1;
705
706         for (i = 1; i <= count; i++) {
707                 union acpi_object *element;
708                 union acpi_object *obj;
709                 struct acpi_power_register *reg;
710                 struct acpi_processor_cx cx;
711
712                 memset(&cx, 0, sizeof(cx));
713
714                 element = &(cst->package.elements[i]);
715                 if (element->type != ACPI_TYPE_PACKAGE)
716                         continue;
717
718                 if (element->package.count != 4)
719                         continue;
720
721                 obj = &(element->package.elements[0]);
722
723                 if (obj->type != ACPI_TYPE_BUFFER)
724                         continue;
725
726                 reg = (struct acpi_power_register *)obj->buffer.pointer;
727
728                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
729                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
730                         continue;
731
732                 /* There should be an easy way to extract an integer... */
733                 obj = &(element->package.elements[1]);
734                 if (obj->type != ACPI_TYPE_INTEGER)
735                         continue;
736
737                 cx.type = obj->integer.value;
738                 /*
739                  * Some buggy BIOSes won't list C1 in _CST -
740                  * Let acpi_processor_get_power_info_default() handle them later
741                  */
742                 if (i == 1 && cx.type != ACPI_STATE_C1)
743                         current_count++;
744
745                 cx.address = reg->address;
746                 cx.index = current_count + 1;
747
748                 cx.space_id = ACPI_CSTATE_SYSTEMIO;
749                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
750                         if (acpi_processor_ffh_cstate_probe
751                                         (pr->id, &cx, reg) == 0) {
752                                 cx.space_id = ACPI_CSTATE_FFH;
753                         } else if (cx.type != ACPI_STATE_C1) {
754                                 /*
755                                  * C1 is a special case where FIXED_HARDWARE
756                                  * can be handled in non-MWAIT way as well.
757                                  * In that case, save this _CST entry info.
758                                  * That is, we retain space_id of SYSTEM_IO for
759                                  * halt based C1.
760                                  * Otherwise, ignore this info and continue.
761                                  */
762                                 continue;
763                         }
764                 }
765
766                 obj = &(element->package.elements[2]);
767                 if (obj->type != ACPI_TYPE_INTEGER)
768                         continue;
769
770                 cx.latency = obj->integer.value;
771
772                 obj = &(element->package.elements[3]);
773                 if (obj->type != ACPI_TYPE_INTEGER)
774                         continue;
775
776                 cx.power = obj->integer.value;
777
778                 current_count++;
779                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
780
781                 /*
782                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
783                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
784                  */
785                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
786                         printk(KERN_WARNING
787                                "Limiting number of power states to max (%d)\n",
788                                ACPI_PROCESSOR_MAX_POWER);
789                         printk(KERN_WARNING
790                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
791                         break;
792                 }
793         }
794
795         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
796                           current_count));
797
798         /* Validate number of power states discovered */
799         if (current_count < 2)
800                 status = -EFAULT;
801
802       end:
803         kfree(buffer.pointer);
804
805         return status;
806 }
807
808 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
809 {
810
811         if (!cx->address)
812                 return;
813
814         /*
815          * C2 latency must be less than or equal to 100
816          * microseconds.
817          */
818         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
819                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
820                                   "latency too large [%d]\n", cx->latency));
821                 return;
822         }
823
824         /*
825          * Otherwise we've met all of our C2 requirements.
826          * Normalize the C2 latency to expidite policy
827          */
828         cx->valid = 1;
829         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
830
831         return;
832 }
833
834 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
835                                            struct acpi_processor_cx *cx)
836 {
837         static int bm_check_flag;
838
839
840         if (!cx->address)
841                 return;
842
843         /*
844          * C3 latency must be less than or equal to 1000
845          * microseconds.
846          */
847         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
848                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
849                                   "latency too large [%d]\n", cx->latency));
850                 return;
851         }
852
853         /*
854          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
855          * DMA transfers are used by any ISA device to avoid livelock.
856          * Note that we could disable Type-F DMA (as recommended by
857          * the erratum), but this is known to disrupt certain ISA
858          * devices thus we take the conservative approach.
859          */
860         else if (errata.piix4.fdma) {
861                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
862                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
863                 return;
864         }
865
866         /* All the logic here assumes flags.bm_check is same across all CPUs */
867         if (!bm_check_flag) {
868                 /* Determine whether bm_check is needed based on CPU  */
869                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
870                 bm_check_flag = pr->flags.bm_check;
871         } else {
872                 pr->flags.bm_check = bm_check_flag;
873         }
874
875         if (pr->flags.bm_check) {
876                 /* bus mastering control is necessary */
877                 if (!pr->flags.bm_control) {
878                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
879                                           "C3 support requires bus mastering control\n"));
880                         return;
881                 }
882         } else {
883                 /*
884                  * WBINVD should be set in fadt, for C3 state to be
885                  * supported on when bm_check is not required.
886                  */
887                 if (!(acpi_fadt.flags & ACPI_FADT_WBINVD)) {
888                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
889                                           "Cache invalidation should work properly"
890                                           " for C3 to be enabled on SMP systems\n"));
891                         return;
892                 }
893                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
894                                   0, ACPI_MTX_DO_NOT_LOCK);
895         }
896
897         /*
898          * Otherwise we've met all of our C3 requirements.
899          * Normalize the C3 latency to expidite policy.  Enable
900          * checking of bus mastering status (bm_check) so we can
901          * use this in our C3 policy
902          */
903         cx->valid = 1;
904         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
905
906         return;
907 }
908
909 static int acpi_processor_power_verify(struct acpi_processor *pr)
910 {
911         unsigned int i;
912         unsigned int working = 0;
913
914 #ifdef ARCH_APICTIMER_STOPS_ON_C3
915         int timer_broadcast = 0;
916         cpumask_t mask = cpumask_of_cpu(pr->id);
917         on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
918 #endif
919
920         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
921                 struct acpi_processor_cx *cx = &pr->power.states[i];
922
923                 switch (cx->type) {
924                 case ACPI_STATE_C1:
925                         cx->valid = 1;
926                         break;
927
928                 case ACPI_STATE_C2:
929                         acpi_processor_power_verify_c2(cx);
930 #ifdef ARCH_APICTIMER_STOPS_ON_C3
931                         /* Some AMD systems fake C3 as C2, but still
932                            have timer troubles */
933                         if (cx->valid && 
934                                 boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
935                                 timer_broadcast++;
936 #endif
937                         break;
938
939                 case ACPI_STATE_C3:
940                         acpi_processor_power_verify_c3(pr, cx);
941 #ifdef ARCH_APICTIMER_STOPS_ON_C3
942                         if (cx->valid)
943                                 timer_broadcast++;
944 #endif
945                         break;
946                 }
947
948                 if (cx->valid)
949                         working++;
950         }
951
952 #ifdef ARCH_APICTIMER_STOPS_ON_C3
953         if (timer_broadcast)
954                 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
955 #endif
956
957         return (working);
958 }
959
960 static int acpi_processor_get_power_info(struct acpi_processor *pr)
961 {
962         unsigned int i;
963         int result;
964
965
966         /* NOTE: the idle thread may not be running while calling
967          * this function */
968
969         /* Zero initialize all the C-states info. */
970         memset(pr->power.states, 0, sizeof(pr->power.states));
971
972         result = acpi_processor_get_power_info_cst(pr);
973         if (result == -ENODEV)
974                 result = acpi_processor_get_power_info_fadt(pr);
975
976         if (result)
977                 return result;
978
979         acpi_processor_get_power_info_default(pr);
980
981         pr->power.count = acpi_processor_power_verify(pr);
982
983         /*
984          * Set Default Policy
985          * ------------------
986          * Now that we know which states are supported, set the default
987          * policy.  Note that this policy can be changed dynamically
988          * (e.g. encourage deeper sleeps to conserve battery life when
989          * not on AC).
990          */
991         result = acpi_processor_set_power_policy(pr);
992         if (result)
993                 return result;
994
995         /*
996          * if one state of type C2 or C3 is available, mark this
997          * CPU as being "idle manageable"
998          */
999         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1000                 if (pr->power.states[i].valid) {
1001                         pr->power.count = i;
1002                         if (pr->power.states[i].type >= ACPI_STATE_C2)
1003                                 pr->flags.power = 1;
1004                 }
1005         }
1006
1007         return 0;
1008 }
1009
1010 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1011 {
1012         int result = 0;
1013
1014
1015         if (!pr)
1016                 return -EINVAL;
1017
1018         if (nocst) {
1019                 return -ENODEV;
1020         }
1021
1022         if (!pr->flags.power_setup_done)
1023                 return -ENODEV;
1024
1025         /* Fall back to the default idle loop */
1026         pm_idle = pm_idle_save;
1027         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
1028
1029         pr->flags.power = 0;
1030         result = acpi_processor_get_power_info(pr);
1031         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1032                 pm_idle = acpi_processor_idle;
1033
1034         return result;
1035 }
1036
1037 /* proc interface */
1038
1039 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1040 {
1041         struct acpi_processor *pr = seq->private;
1042         unsigned int i;
1043
1044
1045         if (!pr)
1046                 goto end;
1047
1048         seq_printf(seq, "active state:            C%zd\n"
1049                    "max_cstate:              C%d\n"
1050                    "bus master activity:     %08x\n"
1051                    "maximum allowed latency: %d usec\n",
1052                    pr->power.state ? pr->power.state - pr->power.states : 0,
1053                    max_cstate, (unsigned)pr->power.bm_activity,
1054                    system_latency_constraint());
1055
1056         seq_puts(seq, "states:\n");
1057
1058         for (i = 1; i <= pr->power.count; i++) {
1059                 seq_printf(seq, "   %cC%d:                  ",
1060                            (&pr->power.states[i] ==
1061                             pr->power.state ? '*' : ' '), i);
1062
1063                 if (!pr->power.states[i].valid) {
1064                         seq_puts(seq, "<not supported>\n");
1065                         continue;
1066                 }
1067
1068                 switch (pr->power.states[i].type) {
1069                 case ACPI_STATE_C1:
1070                         seq_printf(seq, "type[C1] ");
1071                         break;
1072                 case ACPI_STATE_C2:
1073                         seq_printf(seq, "type[C2] ");
1074                         break;
1075                 case ACPI_STATE_C3:
1076                         seq_printf(seq, "type[C3] ");
1077                         break;
1078                 default:
1079                         seq_printf(seq, "type[--] ");
1080                         break;
1081                 }
1082
1083                 if (pr->power.states[i].promotion.state)
1084                         seq_printf(seq, "promotion[C%zd] ",
1085                                    (pr->power.states[i].promotion.state -
1086                                     pr->power.states));
1087                 else
1088                         seq_puts(seq, "promotion[--] ");
1089
1090                 if (pr->power.states[i].demotion.state)
1091                         seq_printf(seq, "demotion[C%zd] ",
1092                                    (pr->power.states[i].demotion.state -
1093                                     pr->power.states));
1094                 else
1095                         seq_puts(seq, "demotion[--] ");
1096
1097                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1098                            pr->power.states[i].latency,
1099                            pr->power.states[i].usage,
1100                            pr->power.states[i].time);
1101         }
1102
1103       end:
1104         return 0;
1105 }
1106
1107 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1108 {
1109         return single_open(file, acpi_processor_power_seq_show,
1110                            PDE(inode)->data);
1111 }
1112
1113 static const struct file_operations acpi_processor_power_fops = {
1114         .open = acpi_processor_power_open_fs,
1115         .read = seq_read,
1116         .llseek = seq_lseek,
1117         .release = single_release,
1118 };
1119
1120 #ifdef CONFIG_SMP
1121 static void smp_callback(void *v)
1122 {
1123         /* we already woke the CPU up, nothing more to do */
1124 }
1125
1126 /*
1127  * This function gets called when a part of the kernel has a new latency
1128  * requirement.  This means we need to get all processors out of their C-state,
1129  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1130  * wakes them all right up.
1131  */
1132 static int acpi_processor_latency_notify(struct notifier_block *b,
1133                 unsigned long l, void *v)
1134 {
1135         smp_call_function(smp_callback, NULL, 0, 1);
1136         return NOTIFY_OK;
1137 }
1138
1139 static struct notifier_block acpi_processor_latency_notifier = {
1140         .notifier_call = acpi_processor_latency_notify,
1141 };
1142 #endif
1143
1144 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1145                               struct acpi_device *device)
1146 {
1147         acpi_status status = 0;
1148         static int first_run;
1149         struct proc_dir_entry *entry = NULL;
1150         unsigned int i;
1151
1152
1153         if (!first_run) {
1154                 dmi_check_system(processor_power_dmi_table);
1155                 if (max_cstate < ACPI_C_STATES_MAX)
1156                         printk(KERN_NOTICE
1157                                "ACPI: processor limited to max C-state %d\n",
1158                                max_cstate);
1159                 first_run++;
1160 #ifdef CONFIG_SMP
1161                 register_latency_notifier(&acpi_processor_latency_notifier);
1162 #endif
1163         }
1164
1165         if (!pr)
1166                 return -EINVAL;
1167
1168         if (acpi_fadt.cst_control && !nocst) {
1169                 status =
1170                     acpi_os_write_port(acpi_fadt.smi_command, acpi_fadt.cst_control, 8);
1171                 if (ACPI_FAILURE(status)) {
1172                         ACPI_EXCEPTION((AE_INFO, status,
1173                                         "Notifying BIOS of _CST ability failed"));
1174                 }
1175         }
1176
1177         acpi_processor_get_power_info(pr);
1178
1179         /*
1180          * Install the idle handler if processor power management is supported.
1181          * Note that we use previously set idle handler will be used on
1182          * platforms that only support C1.
1183          */
1184         if ((pr->flags.power) && (!boot_option_idle_override)) {
1185                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1186                 for (i = 1; i <= pr->power.count; i++)
1187                         if (pr->power.states[i].valid)
1188                                 printk(" C%d[C%d]", i,
1189                                        pr->power.states[i].type);
1190                 printk(")\n");
1191
1192                 if (pr->id == 0) {
1193                         pm_idle_save = pm_idle;
1194                         pm_idle = acpi_processor_idle;
1195                 }
1196         }
1197
1198         /* 'power' [R] */
1199         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1200                                   S_IRUGO, acpi_device_dir(device));
1201         if (!entry)
1202                 return -EIO;
1203         else {
1204                 entry->proc_fops = &acpi_processor_power_fops;
1205                 entry->data = acpi_driver_data(device);
1206                 entry->owner = THIS_MODULE;
1207         }
1208
1209         pr->flags.power_setup_done = 1;
1210
1211         return 0;
1212 }
1213
1214 int acpi_processor_power_exit(struct acpi_processor *pr,
1215                               struct acpi_device *device)
1216 {
1217
1218         pr->flags.power_setup_done = 0;
1219
1220         if (acpi_device_dir(device))
1221                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1222                                   acpi_device_dir(device));
1223
1224         /* Unregister the idle handler when processor #0 is removed. */
1225         if (pr->id == 0) {
1226                 pm_idle = pm_idle_save;
1227
1228                 /*
1229                  * We are about to unload the current idle thread pm callback
1230                  * (pm_idle), Wait for all processors to update cached/local
1231                  * copies of pm_idle before proceeding.
1232                  */
1233                 cpu_idle_wait();
1234 #ifdef CONFIG_SMP
1235                 unregister_latency_notifier(&acpi_processor_latency_notifier);
1236 #endif
1237         }
1238
1239         return 0;
1240 }