Merge ../linus
[linux-2.6] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004, 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.tmr_val_ext)
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         smp_mb__after_clear_bit();
215         if (!need_resched())
216                 safe_halt();
217         current_thread_info()->status |= TS_POLLING;
218 }
219
220 static atomic_t c3_cpu_count;
221
222 /* Common C-state entry for C2, C3, .. */
223 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
224 {
225         if (cstate->space_id == ACPI_CSTATE_FFH) {
226                 /* Call into architectural FFH based C-state */
227                 acpi_processor_ffh_cstate_enter(cstate);
228         } else {
229                 int unused;
230                 /* IO port based C-state */
231                 inb(cstate->address);
232                 /* Dummy wait op - must do something useless after P_LVL2 read
233                    because chipsets cannot guarantee that STPCLK# signal
234                    gets asserted in time to freeze execution properly. */
235                 unused = inl(acpi_fadt.xpm_tmr_blk.address);
236         }
237 }
238
239 static void acpi_processor_idle(void)
240 {
241         struct acpi_processor *pr = NULL;
242         struct acpi_processor_cx *cx = NULL;
243         struct acpi_processor_cx *next_state = NULL;
244         int sleep_ticks = 0;
245         u32 t1, t2 = 0;
246
247         pr = processors[smp_processor_id()];
248         if (!pr)
249                 return;
250
251         /*
252          * Interrupts must be disabled during bus mastering calculations and
253          * for C2/C3 transitions.
254          */
255         local_irq_disable();
256
257         /*
258          * Check whether we truly need to go idle, or should
259          * reschedule:
260          */
261         if (unlikely(need_resched())) {
262                 local_irq_enable();
263                 return;
264         }
265
266         cx = pr->power.state;
267         if (!cx) {
268                 if (pm_idle_save)
269                         pm_idle_save();
270                 else
271                         acpi_safe_halt();
272                 return;
273         }
274
275         /*
276          * Check BM Activity
277          * -----------------
278          * Check for bus mastering activity (if required), record, and check
279          * for demotion.
280          */
281         if (pr->flags.bm_check) {
282                 u32 bm_status = 0;
283                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
284
285                 if (diff > 31)
286                         diff = 31;
287
288                 pr->power.bm_activity <<= diff;
289
290                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
291                                   &bm_status, ACPI_MTX_DO_NOT_LOCK);
292                 if (bm_status) {
293                         pr->power.bm_activity |= 0x1;
294                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
295                                           1, ACPI_MTX_DO_NOT_LOCK);
296                 }
297                 /*
298                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
299                  * the true state of bus mastering activity; forcing us to
300                  * manually check the BMIDEA bit of each IDE channel.
301                  */
302                 else if (errata.piix4.bmisx) {
303                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
304                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
305                                 pr->power.bm_activity |= 0x1;
306                 }
307
308                 pr->power.bm_check_timestamp = jiffies;
309
310                 /*
311                  * If bus mastering is or was active this jiffy, demote
312                  * to avoid a faulty transition.  Note that the processor
313                  * won't enter a low-power state during this call (to this
314                  * function) but should upon the next.
315                  *
316                  * TBD: A better policy might be to fallback to the demotion
317                  *      state (use it for this quantum only) istead of
318                  *      demoting -- and rely on duration as our sole demotion
319                  *      qualification.  This may, however, introduce DMA
320                  *      issues (e.g. floppy DMA transfer overrun/underrun).
321                  */
322                 if ((pr->power.bm_activity & 0x1) &&
323                     cx->demotion.threshold.bm) {
324                         local_irq_enable();
325                         next_state = cx->demotion.state;
326                         goto end;
327                 }
328         }
329
330 #ifdef CONFIG_HOTPLUG_CPU
331         /*
332          * Check for P_LVL2_UP flag before entering C2 and above on
333          * an SMP system. We do it here instead of doing it at _CST/P_LVL
334          * detection phase, to work cleanly with logical CPU hotplug.
335          */
336         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
337             !pr->flags.has_cst && !acpi_fadt.plvl2_up)
338                 cx = &pr->power.states[ACPI_STATE_C1];
339 #endif
340
341         /*
342          * Sleep:
343          * ------
344          * Invoke the current Cx state to put the processor to sleep.
345          */
346         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
347                 current_thread_info()->status &= ~TS_POLLING;
348                 smp_mb__after_clear_bit();
349                 if (need_resched()) {
350                         current_thread_info()->status |= TS_POLLING;
351                         local_irq_enable();
352                         return;
353                 }
354         }
355
356         switch (cx->type) {
357
358         case ACPI_STATE_C1:
359                 /*
360                  * Invoke C1.
361                  * Use the appropriate idle routine, the one that would
362                  * be used without acpi C-states.
363                  */
364                 if (pm_idle_save)
365                         pm_idle_save();
366                 else
367                         acpi_safe_halt();
368
369                 /*
370                  * TBD: Can't get time duration while in C1, as resumes
371                  *      go to an ISR rather than here.  Need to instrument
372                  *      base interrupt handler.
373                  */
374                 sleep_ticks = 0xFFFFFFFF;
375                 break;
376
377         case ACPI_STATE_C2:
378                 /* Get start time (ticks) */
379                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
380                 /* Invoke C2 */
381                 acpi_cstate_enter(cx);
382                 /* Get end time (ticks) */
383                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
384
385 #ifdef CONFIG_GENERIC_TIME
386                 /* TSC halts in C2, so notify users */
387                 mark_tsc_unstable();
388 #endif
389                 /* Re-enable interrupts */
390                 local_irq_enable();
391                 current_thread_info()->status |= TS_POLLING;
392                 /* Compute time (ticks) that we were actually asleep */
393                 sleep_ticks =
394                     ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
395                 break;
396
397         case ACPI_STATE_C3:
398
399                 if (pr->flags.bm_check) {
400                         if (atomic_inc_return(&c3_cpu_count) ==
401                             num_online_cpus()) {
402                                 /*
403                                  * All CPUs are trying to go to C3
404                                  * Disable bus master arbitration
405                                  */
406                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1,
407                                                   ACPI_MTX_DO_NOT_LOCK);
408                         }
409                 } else {
410                         /* SMP with no shared cache... Invalidate cache  */
411                         ACPI_FLUSH_CPU_CACHE();
412                 }
413
414                 /* Get start time (ticks) */
415                 t1 = inl(acpi_fadt.xpm_tmr_blk.address);
416                 /* Invoke C3 */
417                 acpi_cstate_enter(cx);
418                 /* Get end time (ticks) */
419                 t2 = inl(acpi_fadt.xpm_tmr_blk.address);
420                 if (pr->flags.bm_check) {
421                         /* Enable bus master arbitration */
422                         atomic_dec(&c3_cpu_count);
423                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0,
424                                           ACPI_MTX_DO_NOT_LOCK);
425                 }
426
427 #ifdef CONFIG_GENERIC_TIME
428                 /* TSC halts in C3, so notify users */
429                 mark_tsc_unstable();
430 #endif
431                 /* Re-enable interrupts */
432                 local_irq_enable();
433                 current_thread_info()->status |= TS_POLLING;
434                 /* Compute time (ticks) that we were actually asleep */
435                 sleep_ticks =
436                     ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
437                 break;
438
439         default:
440                 local_irq_enable();
441                 return;
442         }
443         cx->usage++;
444         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
445                 cx->time += sleep_ticks;
446
447         next_state = pr->power.state;
448
449 #ifdef CONFIG_HOTPLUG_CPU
450         /* Don't do promotion/demotion */
451         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
452             !pr->flags.has_cst && !acpi_fadt.plvl2_up) {
453                 next_state = cx;
454                 goto end;
455         }
456 #endif
457
458         /*
459          * Promotion?
460          * ----------
461          * Track the number of longs (time asleep is greater than threshold)
462          * and promote when the count threshold is reached.  Note that bus
463          * mastering activity may prevent promotions.
464          * Do not promote above max_cstate.
465          */
466         if (cx->promotion.state &&
467             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
468                 if (sleep_ticks > cx->promotion.threshold.ticks &&
469                   cx->promotion.state->latency <= system_latency_constraint()) {
470                         cx->promotion.count++;
471                         cx->demotion.count = 0;
472                         if (cx->promotion.count >=
473                             cx->promotion.threshold.count) {
474                                 if (pr->flags.bm_check) {
475                                         if (!
476                                             (pr->power.bm_activity & cx->
477                                              promotion.threshold.bm)) {
478                                                 next_state =
479                                                     cx->promotion.state;
480                                                 goto end;
481                                         }
482                                 } else {
483                                         next_state = cx->promotion.state;
484                                         goto end;
485                                 }
486                         }
487                 }
488         }
489
490         /*
491          * Demotion?
492          * ---------
493          * Track the number of shorts (time asleep is less than time threshold)
494          * and demote when the usage threshold is reached.
495          */
496         if (cx->demotion.state) {
497                 if (sleep_ticks < cx->demotion.threshold.ticks) {
498                         cx->demotion.count++;
499                         cx->promotion.count = 0;
500                         if (cx->demotion.count >= cx->demotion.threshold.count) {
501                                 next_state = cx->demotion.state;
502                                 goto end;
503                         }
504                 }
505         }
506
507       end:
508         /*
509          * Demote if current state exceeds max_cstate
510          * or if the latency of the current state is unacceptable
511          */
512         if ((pr->power.state - pr->power.states) > max_cstate ||
513                 pr->power.state->latency > system_latency_constraint()) {
514                 if (cx->demotion.state)
515                         next_state = cx->demotion.state;
516         }
517
518         /*
519          * New Cx State?
520          * -------------
521          * If we're going to start using a new Cx state we must clean up
522          * from the previous and prepare to use the new.
523          */
524         if (next_state != pr->power.state)
525                 acpi_processor_power_activate(pr, next_state);
526 }
527
528 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
529 {
530         unsigned int i;
531         unsigned int state_is_set = 0;
532         struct acpi_processor_cx *lower = NULL;
533         struct acpi_processor_cx *higher = NULL;
534         struct acpi_processor_cx *cx;
535
536
537         if (!pr)
538                 return -EINVAL;
539
540         /*
541          * This function sets the default Cx state policy (OS idle handler).
542          * Our scheme is to promote quickly to C2 but more conservatively
543          * to C3.  We're favoring C2  for its characteristics of low latency
544          * (quick response), good power savings, and ability to allow bus
545          * mastering activity.  Note that the Cx state policy is completely
546          * customizable and can be altered dynamically.
547          */
548
549         /* startup state */
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 (!state_is_set)
556                         pr->power.state = cx;
557                 state_is_set++;
558                 break;
559         }
560
561         if (!state_is_set)
562                 return -ENODEV;
563
564         /* demotion */
565         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
566                 cx = &pr->power.states[i];
567                 if (!cx->valid)
568                         continue;
569
570                 if (lower) {
571                         cx->demotion.state = lower;
572                         cx->demotion.threshold.ticks = cx->latency_ticks;
573                         cx->demotion.threshold.count = 1;
574                         if (cx->type == ACPI_STATE_C3)
575                                 cx->demotion.threshold.bm = bm_history;
576                 }
577
578                 lower = cx;
579         }
580
581         /* promotion */
582         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
583                 cx = &pr->power.states[i];
584                 if (!cx->valid)
585                         continue;
586
587                 if (higher) {
588                         cx->promotion.state = higher;
589                         cx->promotion.threshold.ticks = cx->latency_ticks;
590                         if (cx->type >= ACPI_STATE_C2)
591                                 cx->promotion.threshold.count = 4;
592                         else
593                                 cx->promotion.threshold.count = 10;
594                         if (higher->type == ACPI_STATE_C3)
595                                 cx->promotion.threshold.bm = bm_history;
596                 }
597
598                 higher = cx;
599         }
600
601         return 0;
602 }
603
604 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
605 {
606
607         if (!pr)
608                 return -EINVAL;
609
610         if (!pr->pblk)
611                 return -ENODEV;
612
613         /* if info is obtained from pblk/fadt, type equals state */
614         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
615         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
616
617 #ifndef CONFIG_HOTPLUG_CPU
618         /*
619          * Check for P_LVL2_UP flag before entering C2 and above on
620          * an SMP system. 
621          */
622         if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up)
623                 return -ENODEV;
624 #endif
625
626         /* determine C2 and C3 address from pblk */
627         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
628         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
629
630         /* determine latencies from FADT */
631         pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
632         pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
633
634         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
635                           "lvl2[0x%08x] lvl3[0x%08x]\n",
636                           pr->power.states[ACPI_STATE_C2].address,
637                           pr->power.states[ACPI_STATE_C3].address));
638
639         return 0;
640 }
641
642 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
643 {
644         if (!pr->power.states[ACPI_STATE_C1].valid) {
645                 /* set the first C-State to C1 */
646                 /* all processors need to support C1 */
647                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
648                 pr->power.states[ACPI_STATE_C1].valid = 1;
649         }
650         /* the C0 state only exists as a filler in our array */
651         pr->power.states[ACPI_STATE_C0].valid = 1;
652         return 0;
653 }
654
655 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
656 {
657         acpi_status status = 0;
658         acpi_integer count;
659         int current_count;
660         int i;
661         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
662         union acpi_object *cst;
663
664
665         if (nocst)
666                 return -ENODEV;
667
668         current_count = 0;
669
670         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
671         if (ACPI_FAILURE(status)) {
672                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
673                 return -ENODEV;
674         }
675
676         cst = (union acpi_object *)buffer.pointer;
677
678         /* There must be at least 2 elements */
679         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
680                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
681                 status = -EFAULT;
682                 goto end;
683         }
684
685         count = cst->package.elements[0].integer.value;
686
687         /* Validate number of power states. */
688         if (count < 1 || count != cst->package.count - 1) {
689                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
690                 status = -EFAULT;
691                 goto end;
692         }
693
694         /* Tell driver that at least _CST is supported. */
695         pr->flags.has_cst = 1;
696
697         for (i = 1; i <= count; i++) {
698                 union acpi_object *element;
699                 union acpi_object *obj;
700                 struct acpi_power_register *reg;
701                 struct acpi_processor_cx cx;
702
703                 memset(&cx, 0, sizeof(cx));
704
705                 element = (union acpi_object *)&(cst->package.elements[i]);
706                 if (element->type != ACPI_TYPE_PACKAGE)
707                         continue;
708
709                 if (element->package.count != 4)
710                         continue;
711
712                 obj = (union acpi_object *)&(element->package.elements[0]);
713
714                 if (obj->type != ACPI_TYPE_BUFFER)
715                         continue;
716
717                 reg = (struct acpi_power_register *)obj->buffer.pointer;
718
719                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
720                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
721                         continue;
722
723                 /* There should be an easy way to extract an integer... */
724                 obj = (union acpi_object *)&(element->package.elements[1]);
725                 if (obj->type != ACPI_TYPE_INTEGER)
726                         continue;
727
728                 cx.type = obj->integer.value;
729                 /*
730                  * Some buggy BIOSes won't list C1 in _CST -
731                  * Let acpi_processor_get_power_info_default() handle them later
732                  */
733                 if (i == 1 && cx.type != ACPI_STATE_C1)
734                         current_count++;
735
736                 cx.address = reg->address;
737                 cx.index = current_count + 1;
738
739                 cx.space_id = ACPI_CSTATE_SYSTEMIO;
740                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
741                         if (acpi_processor_ffh_cstate_probe
742                                         (pr->id, &cx, reg) == 0) {
743                                 cx.space_id = ACPI_CSTATE_FFH;
744                         } else if (cx.type != ACPI_STATE_C1) {
745                                 /*
746                                  * C1 is a special case where FIXED_HARDWARE
747                                  * can be handled in non-MWAIT way as well.
748                                  * In that case, save this _CST entry info.
749                                  * That is, we retain space_id of SYSTEM_IO for
750                                  * halt based C1.
751                                  * Otherwise, ignore this info and continue.
752                                  */
753                                 continue;
754                         }
755                 }
756
757                 obj = (union acpi_object *)&(element->package.elements[2]);
758                 if (obj->type != ACPI_TYPE_INTEGER)
759                         continue;
760
761                 cx.latency = obj->integer.value;
762
763                 obj = (union acpi_object *)&(element->package.elements[3]);
764                 if (obj->type != ACPI_TYPE_INTEGER)
765                         continue;
766
767                 cx.power = obj->integer.value;
768
769                 current_count++;
770                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
771
772                 /*
773                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
774                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
775                  */
776                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
777                         printk(KERN_WARNING
778                                "Limiting number of power states to max (%d)\n",
779                                ACPI_PROCESSOR_MAX_POWER);
780                         printk(KERN_WARNING
781                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
782                         break;
783                 }
784         }
785
786         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
787                           current_count));
788
789         /* Validate number of power states discovered */
790         if (current_count < 2)
791                 status = -EFAULT;
792
793       end:
794         kfree(buffer.pointer);
795
796         return status;
797 }
798
799 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
800 {
801
802         if (!cx->address)
803                 return;
804
805         /*
806          * C2 latency must be less than or equal to 100
807          * microseconds.
808          */
809         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
810                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
811                                   "latency too large [%d]\n", cx->latency));
812                 return;
813         }
814
815         /*
816          * Otherwise we've met all of our C2 requirements.
817          * Normalize the C2 latency to expidite policy
818          */
819         cx->valid = 1;
820         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
821
822         return;
823 }
824
825 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
826                                            struct acpi_processor_cx *cx)
827 {
828         static int bm_check_flag;
829
830
831         if (!cx->address)
832                 return;
833
834         /*
835          * C3 latency must be less than or equal to 1000
836          * microseconds.
837          */
838         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
839                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
840                                   "latency too large [%d]\n", cx->latency));
841                 return;
842         }
843
844         /*
845          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
846          * DMA transfers are used by any ISA device to avoid livelock.
847          * Note that we could disable Type-F DMA (as recommended by
848          * the erratum), but this is known to disrupt certain ISA
849          * devices thus we take the conservative approach.
850          */
851         else if (errata.piix4.fdma) {
852                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
853                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
854                 return;
855         }
856
857         /* All the logic here assumes flags.bm_check is same across all CPUs */
858         if (!bm_check_flag) {
859                 /* Determine whether bm_check is needed based on CPU  */
860                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
861                 bm_check_flag = pr->flags.bm_check;
862         } else {
863                 pr->flags.bm_check = bm_check_flag;
864         }
865
866         if (pr->flags.bm_check) {
867                 /* bus mastering control is necessary */
868                 if (!pr->flags.bm_control) {
869                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
870                                           "C3 support requires bus mastering control\n"));
871                         return;
872                 }
873         } else {
874                 /*
875                  * WBINVD should be set in fadt, for C3 state to be
876                  * supported on when bm_check is not required.
877                  */
878                 if (acpi_fadt.wb_invd != 1) {
879                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
880                                           "Cache invalidation should work properly"
881                                           " for C3 to be enabled on SMP systems\n"));
882                         return;
883                 }
884                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
885                                   0, ACPI_MTX_DO_NOT_LOCK);
886         }
887
888         /*
889          * Otherwise we've met all of our C3 requirements.
890          * Normalize the C3 latency to expidite policy.  Enable
891          * checking of bus mastering status (bm_check) so we can
892          * use this in our C3 policy
893          */
894         cx->valid = 1;
895         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
896
897         return;
898 }
899
900 static int acpi_processor_power_verify(struct acpi_processor *pr)
901 {
902         unsigned int i;
903         unsigned int working = 0;
904
905 #ifdef ARCH_APICTIMER_STOPS_ON_C3
906         int timer_broadcast = 0;
907         cpumask_t mask = cpumask_of_cpu(pr->id);
908         on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
909 #endif
910
911         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
912                 struct acpi_processor_cx *cx = &pr->power.states[i];
913
914                 switch (cx->type) {
915                 case ACPI_STATE_C1:
916                         cx->valid = 1;
917                         break;
918
919                 case ACPI_STATE_C2:
920                         acpi_processor_power_verify_c2(cx);
921 #ifdef ARCH_APICTIMER_STOPS_ON_C3
922                         /* Some AMD systems fake C3 as C2, but still
923                            have timer troubles */
924                         if (cx->valid && 
925                                 boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
926                                 timer_broadcast++;
927 #endif
928                         break;
929
930                 case ACPI_STATE_C3:
931                         acpi_processor_power_verify_c3(pr, cx);
932 #ifdef ARCH_APICTIMER_STOPS_ON_C3
933                         if (cx->valid)
934                                 timer_broadcast++;
935 #endif
936                         break;
937                 }
938
939                 if (cx->valid)
940                         working++;
941         }
942
943 #ifdef ARCH_APICTIMER_STOPS_ON_C3
944         if (timer_broadcast)
945                 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
946 #endif
947
948         return (working);
949 }
950
951 static int acpi_processor_get_power_info(struct acpi_processor *pr)
952 {
953         unsigned int i;
954         int result;
955
956
957         /* NOTE: the idle thread may not be running while calling
958          * this function */
959
960         /* Zero initialize all the C-states info. */
961         memset(pr->power.states, 0, sizeof(pr->power.states));
962
963         result = acpi_processor_get_power_info_cst(pr);
964         if (result == -ENODEV)
965                 result = acpi_processor_get_power_info_fadt(pr);
966
967         if (result)
968                 return result;
969
970         acpi_processor_get_power_info_default(pr);
971
972         pr->power.count = acpi_processor_power_verify(pr);
973
974         /*
975          * Set Default Policy
976          * ------------------
977          * Now that we know which states are supported, set the default
978          * policy.  Note that this policy can be changed dynamically
979          * (e.g. encourage deeper sleeps to conserve battery life when
980          * not on AC).
981          */
982         result = acpi_processor_set_power_policy(pr);
983         if (result)
984                 return result;
985
986         /*
987          * if one state of type C2 or C3 is available, mark this
988          * CPU as being "idle manageable"
989          */
990         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
991                 if (pr->power.states[i].valid) {
992                         pr->power.count = i;
993                         if (pr->power.states[i].type >= ACPI_STATE_C2)
994                                 pr->flags.power = 1;
995                 }
996         }
997
998         return 0;
999 }
1000
1001 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1002 {
1003         int result = 0;
1004
1005
1006         if (!pr)
1007                 return -EINVAL;
1008
1009         if (nocst) {
1010                 return -ENODEV;
1011         }
1012
1013         if (!pr->flags.power_setup_done)
1014                 return -ENODEV;
1015
1016         /* Fall back to the default idle loop */
1017         pm_idle = pm_idle_save;
1018         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
1019
1020         pr->flags.power = 0;
1021         result = acpi_processor_get_power_info(pr);
1022         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1023                 pm_idle = acpi_processor_idle;
1024
1025         return result;
1026 }
1027
1028 /* proc interface */
1029
1030 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1031 {
1032         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
1033         unsigned int i;
1034
1035
1036         if (!pr)
1037                 goto end;
1038
1039         seq_printf(seq, "active state:            C%zd\n"
1040                    "max_cstate:              C%d\n"
1041                    "bus master activity:     %08x\n"
1042                    "maximum allowed latency: %d usec\n",
1043                    pr->power.state ? pr->power.state - pr->power.states : 0,
1044                    max_cstate, (unsigned)pr->power.bm_activity,
1045                    system_latency_constraint());
1046
1047         seq_puts(seq, "states:\n");
1048
1049         for (i = 1; i <= pr->power.count; i++) {
1050                 seq_printf(seq, "   %cC%d:                  ",
1051                            (&pr->power.states[i] ==
1052                             pr->power.state ? '*' : ' '), i);
1053
1054                 if (!pr->power.states[i].valid) {
1055                         seq_puts(seq, "<not supported>\n");
1056                         continue;
1057                 }
1058
1059                 switch (pr->power.states[i].type) {
1060                 case ACPI_STATE_C1:
1061                         seq_printf(seq, "type[C1] ");
1062                         break;
1063                 case ACPI_STATE_C2:
1064                         seq_printf(seq, "type[C2] ");
1065                         break;
1066                 case ACPI_STATE_C3:
1067                         seq_printf(seq, "type[C3] ");
1068                         break;
1069                 default:
1070                         seq_printf(seq, "type[--] ");
1071                         break;
1072                 }
1073
1074                 if (pr->power.states[i].promotion.state)
1075                         seq_printf(seq, "promotion[C%zd] ",
1076                                    (pr->power.states[i].promotion.state -
1077                                     pr->power.states));
1078                 else
1079                         seq_puts(seq, "promotion[--] ");
1080
1081                 if (pr->power.states[i].demotion.state)
1082                         seq_printf(seq, "demotion[C%zd] ",
1083                                    (pr->power.states[i].demotion.state -
1084                                     pr->power.states));
1085                 else
1086                         seq_puts(seq, "demotion[--] ");
1087
1088                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1089                            pr->power.states[i].latency,
1090                            pr->power.states[i].usage,
1091                            pr->power.states[i].time);
1092         }
1093
1094       end:
1095         return 0;
1096 }
1097
1098 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1099 {
1100         return single_open(file, acpi_processor_power_seq_show,
1101                            PDE(inode)->data);
1102 }
1103
1104 static const struct file_operations acpi_processor_power_fops = {
1105         .open = acpi_processor_power_open_fs,
1106         .read = seq_read,
1107         .llseek = seq_lseek,
1108         .release = single_release,
1109 };
1110
1111 #ifdef CONFIG_SMP
1112 static void smp_callback(void *v)
1113 {
1114         /* we already woke the CPU up, nothing more to do */
1115 }
1116
1117 /*
1118  * This function gets called when a part of the kernel has a new latency
1119  * requirement.  This means we need to get all processors out of their C-state,
1120  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1121  * wakes them all right up.
1122  */
1123 static int acpi_processor_latency_notify(struct notifier_block *b,
1124                 unsigned long l, void *v)
1125 {
1126         smp_call_function(smp_callback, NULL, 0, 1);
1127         return NOTIFY_OK;
1128 }
1129
1130 static struct notifier_block acpi_processor_latency_notifier = {
1131         .notifier_call = acpi_processor_latency_notify,
1132 };
1133 #endif
1134
1135 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1136                               struct acpi_device *device)
1137 {
1138         acpi_status status = 0;
1139         static int first_run;
1140         struct proc_dir_entry *entry = NULL;
1141         unsigned int i;
1142
1143
1144         if (!first_run) {
1145                 dmi_check_system(processor_power_dmi_table);
1146                 if (max_cstate < ACPI_C_STATES_MAX)
1147                         printk(KERN_NOTICE
1148                                "ACPI: processor limited to max C-state %d\n",
1149                                max_cstate);
1150                 first_run++;
1151 #ifdef CONFIG_SMP
1152                 register_latency_notifier(&acpi_processor_latency_notifier);
1153 #endif
1154         }
1155
1156         if (!pr)
1157                 return -EINVAL;
1158
1159         if (acpi_fadt.cst_cnt && !nocst) {
1160                 status =
1161                     acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
1162                 if (ACPI_FAILURE(status)) {
1163                         ACPI_EXCEPTION((AE_INFO, status,
1164                                         "Notifying BIOS of _CST ability failed"));
1165                 }
1166         }
1167
1168         acpi_processor_get_power_info(pr);
1169
1170         /*
1171          * Install the idle handler if processor power management is supported.
1172          * Note that we use previously set idle handler will be used on
1173          * platforms that only support C1.
1174          */
1175         if ((pr->flags.power) && (!boot_option_idle_override)) {
1176                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1177                 for (i = 1; i <= pr->power.count; i++)
1178                         if (pr->power.states[i].valid)
1179                                 printk(" C%d[C%d]", i,
1180                                        pr->power.states[i].type);
1181                 printk(")\n");
1182
1183                 if (pr->id == 0) {
1184                         pm_idle_save = pm_idle;
1185                         pm_idle = acpi_processor_idle;
1186                 }
1187         }
1188
1189         /* 'power' [R] */
1190         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1191                                   S_IRUGO, acpi_device_dir(device));
1192         if (!entry)
1193                 return -EIO;
1194         else {
1195                 entry->proc_fops = &acpi_processor_power_fops;
1196                 entry->data = acpi_driver_data(device);
1197                 entry->owner = THIS_MODULE;
1198         }
1199
1200         pr->flags.power_setup_done = 1;
1201
1202         return 0;
1203 }
1204
1205 int acpi_processor_power_exit(struct acpi_processor *pr,
1206                               struct acpi_device *device)
1207 {
1208
1209         pr->flags.power_setup_done = 0;
1210
1211         if (acpi_device_dir(device))
1212                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1213                                   acpi_device_dir(device));
1214
1215         /* Unregister the idle handler when processor #0 is removed. */
1216         if (pr->id == 0) {
1217                 pm_idle = pm_idle_save;
1218
1219                 /*
1220                  * We are about to unload the current idle thread pm callback
1221                  * (pm_idle), Wait for all processors to update cached/local
1222                  * copies of pm_idle before proceeding.
1223                  */
1224                 cpu_idle_wait();
1225 #ifdef CONFIG_SMP
1226                 unregister_latency_notifier(&acpi_processor_latency_notifier);
1227 #endif
1228         }
1229
1230         return 0;
1231 }