ACPICA: use new ACPI headers.
[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_gbl_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                         break;
192                 }
193         }
194
195         /* Prepare to use new state. */
196         switch (new->type) {
197         case ACPI_STATE_C3:
198                 /* Enable bus master reload */
199                 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
200                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
201                 break;
202         }
203
204         pr->power.state = new;
205
206         return;
207 }
208
209 static void acpi_safe_halt(void)
210 {
211         current_thread_info()->status &= ~TS_POLLING;
212         /*
213          * TS_POLLING-cleared state must be visible before we
214          * test NEED_RESCHED:
215          */
216         smp_mb();
217         if (!need_resched())
218                 safe_halt();
219         current_thread_info()->status |= TS_POLLING;
220 }
221
222 static atomic_t c3_cpu_count;
223
224 /* Common C-state entry for C2, C3, .. */
225 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
226 {
227         if (cstate->space_id == ACPI_CSTATE_FFH) {
228                 /* Call into architectural FFH based C-state */
229                 acpi_processor_ffh_cstate_enter(cstate);
230         } else {
231                 int unused;
232                 /* IO port based C-state */
233                 inb(cstate->address);
234                 /* Dummy wait op - must do something useless after P_LVL2 read
235                    because chipsets cannot guarantee that STPCLK# signal
236                    gets asserted in time to freeze execution properly. */
237                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
238         }
239 }
240
241 static void acpi_processor_idle(void)
242 {
243         struct acpi_processor *pr = NULL;
244         struct acpi_processor_cx *cx = NULL;
245         struct acpi_processor_cx *next_state = NULL;
246         int sleep_ticks = 0;
247         u32 t1, t2 = 0;
248
249         pr = processors[smp_processor_id()];
250         if (!pr)
251                 return;
252
253         /*
254          * Interrupts must be disabled during bus mastering calculations and
255          * for C2/C3 transitions.
256          */
257         local_irq_disable();
258
259         /*
260          * Check whether we truly need to go idle, or should
261          * reschedule:
262          */
263         if (unlikely(need_resched())) {
264                 local_irq_enable();
265                 return;
266         }
267
268         cx = pr->power.state;
269         if (!cx) {
270                 if (pm_idle_save)
271                         pm_idle_save();
272                 else
273                         acpi_safe_halt();
274                 return;
275         }
276
277         /*
278          * Check BM Activity
279          * -----------------
280          * Check for bus mastering activity (if required), record, and check
281          * for demotion.
282          */
283         if (pr->flags.bm_check) {
284                 u32 bm_status = 0;
285                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
286
287                 if (diff > 31)
288                         diff = 31;
289
290                 pr->power.bm_activity <<= diff;
291
292                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
293                 if (bm_status) {
294                         pr->power.bm_activity |= 0x1;
295                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
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_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
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                 /*
349                  * TS_POLLING-cleared state must be visible before we
350                  * test NEED_RESCHED:
351                  */
352                 smp_mb();
353                 if (need_resched()) {
354                         current_thread_info()->status |= TS_POLLING;
355                         local_irq_enable();
356                         return;
357                 }
358         }
359
360         switch (cx->type) {
361
362         case ACPI_STATE_C1:
363                 /*
364                  * Invoke C1.
365                  * Use the appropriate idle routine, the one that would
366                  * be used without acpi C-states.
367                  */
368                 if (pm_idle_save)
369                         pm_idle_save();
370                 else
371                         acpi_safe_halt();
372
373                 /*
374                  * TBD: Can't get time duration while in C1, as resumes
375                  *      go to an ISR rather than here.  Need to instrument
376                  *      base interrupt handler.
377                  */
378                 sleep_ticks = 0xFFFFFFFF;
379                 break;
380
381         case ACPI_STATE_C2:
382                 /* Get start time (ticks) */
383                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
384                 /* Invoke C2 */
385                 acpi_cstate_enter(cx);
386                 /* Get end time (ticks) */
387                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
388
389 #ifdef CONFIG_GENERIC_TIME
390                 /* TSC halts in C2, so notify users */
391                 mark_tsc_unstable();
392 #endif
393                 /* Re-enable interrupts */
394                 local_irq_enable();
395                 current_thread_info()->status |= TS_POLLING;
396                 /* Compute time (ticks) that we were actually asleep */
397                 sleep_ticks =
398                     ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
399                 break;
400
401         case ACPI_STATE_C3:
402
403                 if (pr->flags.bm_check) {
404                         if (atomic_inc_return(&c3_cpu_count) ==
405                             num_online_cpus()) {
406                                 /*
407                                  * All CPUs are trying to go to C3
408                                  * Disable bus master arbitration
409                                  */
410                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
411                         }
412                 } else {
413                         /* SMP with no shared cache... Invalidate cache  */
414                         ACPI_FLUSH_CPU_CACHE();
415                 }
416
417                 /* Get start time (ticks) */
418                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
419                 /* Invoke C3 */
420                 acpi_cstate_enter(cx);
421                 /* Get end time (ticks) */
422                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
423                 if (pr->flags.bm_check) {
424                         /* Enable bus master arbitration */
425                         atomic_dec(&c3_cpu_count);
426                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
427                 }
428
429 #ifdef CONFIG_GENERIC_TIME
430                 /* TSC halts in C3, so notify users */
431                 mark_tsc_unstable();
432 #endif
433                 /* Re-enable interrupts */
434                 local_irq_enable();
435                 current_thread_info()->status |= TS_POLLING;
436                 /* Compute time (ticks) that we were actually asleep */
437                 sleep_ticks =
438                     ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
439                 break;
440
441         default:
442                 local_irq_enable();
443                 return;
444         }
445         cx->usage++;
446         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
447                 cx->time += sleep_ticks;
448
449         next_state = pr->power.state;
450
451 #ifdef CONFIG_HOTPLUG_CPU
452         /* Don't do promotion/demotion */
453         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
454             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
455                 next_state = cx;
456                 goto end;
457         }
458 #endif
459
460         /*
461          * Promotion?
462          * ----------
463          * Track the number of longs (time asleep is greater than threshold)
464          * and promote when the count threshold is reached.  Note that bus
465          * mastering activity may prevent promotions.
466          * Do not promote above max_cstate.
467          */
468         if (cx->promotion.state &&
469             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
470                 if (sleep_ticks > cx->promotion.threshold.ticks &&
471                   cx->promotion.state->latency <= system_latency_constraint()) {
472                         cx->promotion.count++;
473                         cx->demotion.count = 0;
474                         if (cx->promotion.count >=
475                             cx->promotion.threshold.count) {
476                                 if (pr->flags.bm_check) {
477                                         if (!
478                                             (pr->power.bm_activity & cx->
479                                              promotion.threshold.bm)) {
480                                                 next_state =
481                                                     cx->promotion.state;
482                                                 goto end;
483                                         }
484                                 } else {
485                                         next_state = cx->promotion.state;
486                                         goto end;
487                                 }
488                         }
489                 }
490         }
491
492         /*
493          * Demotion?
494          * ---------
495          * Track the number of shorts (time asleep is less than time threshold)
496          * and demote when the usage threshold is reached.
497          */
498         if (cx->demotion.state) {
499                 if (sleep_ticks < cx->demotion.threshold.ticks) {
500                         cx->demotion.count++;
501                         cx->promotion.count = 0;
502                         if (cx->demotion.count >= cx->demotion.threshold.count) {
503                                 next_state = cx->demotion.state;
504                                 goto end;
505                         }
506                 }
507         }
508
509       end:
510         /*
511          * Demote if current state exceeds max_cstate
512          * or if the latency of the current state is unacceptable
513          */
514         if ((pr->power.state - pr->power.states) > max_cstate ||
515                 pr->power.state->latency > system_latency_constraint()) {
516                 if (cx->demotion.state)
517                         next_state = cx->demotion.state;
518         }
519
520         /*
521          * New Cx State?
522          * -------------
523          * If we're going to start using a new Cx state we must clean up
524          * from the previous and prepare to use the new.
525          */
526         if (next_state != pr->power.state)
527                 acpi_processor_power_activate(pr, next_state);
528 }
529
530 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
531 {
532         unsigned int i;
533         unsigned int state_is_set = 0;
534         struct acpi_processor_cx *lower = NULL;
535         struct acpi_processor_cx *higher = NULL;
536         struct acpi_processor_cx *cx;
537
538
539         if (!pr)
540                 return -EINVAL;
541
542         /*
543          * This function sets the default Cx state policy (OS idle handler).
544          * Our scheme is to promote quickly to C2 but more conservatively
545          * to C3.  We're favoring C2  for its characteristics of low latency
546          * (quick response), good power savings, and ability to allow bus
547          * mastering activity.  Note that the Cx state policy is completely
548          * customizable and can be altered dynamically.
549          */
550
551         /* startup state */
552         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
553                 cx = &pr->power.states[i];
554                 if (!cx->valid)
555                         continue;
556
557                 if (!state_is_set)
558                         pr->power.state = cx;
559                 state_is_set++;
560                 break;
561         }
562
563         if (!state_is_set)
564                 return -ENODEV;
565
566         /* demotion */
567         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
568                 cx = &pr->power.states[i];
569                 if (!cx->valid)
570                         continue;
571
572                 if (lower) {
573                         cx->demotion.state = lower;
574                         cx->demotion.threshold.ticks = cx->latency_ticks;
575                         cx->demotion.threshold.count = 1;
576                         if (cx->type == ACPI_STATE_C3)
577                                 cx->demotion.threshold.bm = bm_history;
578                 }
579
580                 lower = cx;
581         }
582
583         /* promotion */
584         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
585                 cx = &pr->power.states[i];
586                 if (!cx->valid)
587                         continue;
588
589                 if (higher) {
590                         cx->promotion.state = higher;
591                         cx->promotion.threshold.ticks = cx->latency_ticks;
592                         if (cx->type >= ACPI_STATE_C2)
593                                 cx->promotion.threshold.count = 4;
594                         else
595                                 cx->promotion.threshold.count = 10;
596                         if (higher->type == ACPI_STATE_C3)
597                                 cx->promotion.threshold.bm = bm_history;
598                 }
599
600                 higher = cx;
601         }
602
603         return 0;
604 }
605
606 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
607 {
608
609         if (!pr)
610                 return -EINVAL;
611
612         if (!pr->pblk)
613                 return -ENODEV;
614
615         /* if info is obtained from pblk/fadt, type equals state */
616         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
617         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
618
619 #ifndef CONFIG_HOTPLUG_CPU
620         /*
621          * Check for P_LVL2_UP flag before entering C2 and above on
622          * an SMP system. 
623          */
624         if ((num_online_cpus() > 1) &&
625             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
626                 return -ENODEV;
627 #endif
628
629         /* determine C2 and C3 address from pblk */
630         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
631         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
632
633         /* determine latencies from FADT */
634         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
635         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
636
637         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
638                           "lvl2[0x%08x] lvl3[0x%08x]\n",
639                           pr->power.states[ACPI_STATE_C2].address,
640                           pr->power.states[ACPI_STATE_C3].address));
641
642         return 0;
643 }
644
645 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
646 {
647         if (!pr->power.states[ACPI_STATE_C1].valid) {
648                 /* set the first C-State to C1 */
649                 /* all processors need to support C1 */
650                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
651                 pr->power.states[ACPI_STATE_C1].valid = 1;
652         }
653         /* the C0 state only exists as a filler in our array */
654         pr->power.states[ACPI_STATE_C0].valid = 1;
655         return 0;
656 }
657
658 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
659 {
660         acpi_status status = 0;
661         acpi_integer count;
662         int current_count;
663         int i;
664         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
665         union acpi_object *cst;
666
667
668         if (nocst)
669                 return -ENODEV;
670
671         current_count = 0;
672
673         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
674         if (ACPI_FAILURE(status)) {
675                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
676                 return -ENODEV;
677         }
678
679         cst = buffer.pointer;
680
681         /* There must be at least 2 elements */
682         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
683                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
684                 status = -EFAULT;
685                 goto end;
686         }
687
688         count = cst->package.elements[0].integer.value;
689
690         /* Validate number of power states. */
691         if (count < 1 || count != cst->package.count - 1) {
692                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
693                 status = -EFAULT;
694                 goto end;
695         }
696
697         /* Tell driver that at least _CST is supported. */
698         pr->flags.has_cst = 1;
699
700         for (i = 1; i <= count; i++) {
701                 union acpi_object *element;
702                 union acpi_object *obj;
703                 struct acpi_power_register *reg;
704                 struct acpi_processor_cx cx;
705
706                 memset(&cx, 0, sizeof(cx));
707
708                 element = &(cst->package.elements[i]);
709                 if (element->type != ACPI_TYPE_PACKAGE)
710                         continue;
711
712                 if (element->package.count != 4)
713                         continue;
714
715                 obj = &(element->package.elements[0]);
716
717                 if (obj->type != ACPI_TYPE_BUFFER)
718                         continue;
719
720                 reg = (struct acpi_power_register *)obj->buffer.pointer;
721
722                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
723                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
724                         continue;
725
726                 /* There should be an easy way to extract an integer... */
727                 obj = &(element->package.elements[1]);
728                 if (obj->type != ACPI_TYPE_INTEGER)
729                         continue;
730
731                 cx.type = obj->integer.value;
732                 /*
733                  * Some buggy BIOSes won't list C1 in _CST -
734                  * Let acpi_processor_get_power_info_default() handle them later
735                  */
736                 if (i == 1 && cx.type != ACPI_STATE_C1)
737                         current_count++;
738
739                 cx.address = reg->address;
740                 cx.index = current_count + 1;
741
742                 cx.space_id = ACPI_CSTATE_SYSTEMIO;
743                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
744                         if (acpi_processor_ffh_cstate_probe
745                                         (pr->id, &cx, reg) == 0) {
746                                 cx.space_id = ACPI_CSTATE_FFH;
747                         } else if (cx.type != ACPI_STATE_C1) {
748                                 /*
749                                  * C1 is a special case where FIXED_HARDWARE
750                                  * can be handled in non-MWAIT way as well.
751                                  * In that case, save this _CST entry info.
752                                  * That is, we retain space_id of SYSTEM_IO for
753                                  * halt based C1.
754                                  * Otherwise, ignore this info and continue.
755                                  */
756                                 continue;
757                         }
758                 }
759
760                 obj = &(element->package.elements[2]);
761                 if (obj->type != ACPI_TYPE_INTEGER)
762                         continue;
763
764                 cx.latency = obj->integer.value;
765
766                 obj = &(element->package.elements[3]);
767                 if (obj->type != ACPI_TYPE_INTEGER)
768                         continue;
769
770                 cx.power = obj->integer.value;
771
772                 current_count++;
773                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
774
775                 /*
776                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
777                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
778                  */
779                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
780                         printk(KERN_WARNING
781                                "Limiting number of power states to max (%d)\n",
782                                ACPI_PROCESSOR_MAX_POWER);
783                         printk(KERN_WARNING
784                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
785                         break;
786                 }
787         }
788
789         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
790                           current_count));
791
792         /* Validate number of power states discovered */
793         if (current_count < 2)
794                 status = -EFAULT;
795
796       end:
797         kfree(buffer.pointer);
798
799         return status;
800 }
801
802 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
803 {
804
805         if (!cx->address)
806                 return;
807
808         /*
809          * C2 latency must be less than or equal to 100
810          * microseconds.
811          */
812         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
813                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
814                                   "latency too large [%d]\n", cx->latency));
815                 return;
816         }
817
818         /*
819          * Otherwise we've met all of our C2 requirements.
820          * Normalize the C2 latency to expidite policy
821          */
822         cx->valid = 1;
823         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
824
825         return;
826 }
827
828 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
829                                            struct acpi_processor_cx *cx)
830 {
831         static int bm_check_flag;
832
833
834         if (!cx->address)
835                 return;
836
837         /*
838          * C3 latency must be less than or equal to 1000
839          * microseconds.
840          */
841         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
842                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
843                                   "latency too large [%d]\n", cx->latency));
844                 return;
845         }
846
847         /*
848          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
849          * DMA transfers are used by any ISA device to avoid livelock.
850          * Note that we could disable Type-F DMA (as recommended by
851          * the erratum), but this is known to disrupt certain ISA
852          * devices thus we take the conservative approach.
853          */
854         else if (errata.piix4.fdma) {
855                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
856                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
857                 return;
858         }
859
860         /* All the logic here assumes flags.bm_check is same across all CPUs */
861         if (!bm_check_flag) {
862                 /* Determine whether bm_check is needed based on CPU  */
863                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
864                 bm_check_flag = pr->flags.bm_check;
865         } else {
866                 pr->flags.bm_check = bm_check_flag;
867         }
868
869         if (pr->flags.bm_check) {
870                 /* bus mastering control is necessary */
871                 if (!pr->flags.bm_control) {
872                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
873                                           "C3 support requires bus mastering control\n"));
874                         return;
875                 }
876         } else {
877                 /*
878                  * WBINVD should be set in fadt, for C3 state to be
879                  * supported on when bm_check is not required.
880                  */
881                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
882                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
883                                           "Cache invalidation should work properly"
884                                           " for C3 to be enabled on SMP systems\n"));
885                         return;
886                 }
887                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
888         }
889
890         /*
891          * Otherwise we've met all of our C3 requirements.
892          * Normalize the C3 latency to expidite policy.  Enable
893          * checking of bus mastering status (bm_check) so we can
894          * use this in our C3 policy
895          */
896         cx->valid = 1;
897         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
898
899         return;
900 }
901
902 static int acpi_processor_power_verify(struct acpi_processor *pr)
903 {
904         unsigned int i;
905         unsigned int working = 0;
906
907 #ifdef ARCH_APICTIMER_STOPS_ON_C3
908         int timer_broadcast = 0;
909         cpumask_t mask = cpumask_of_cpu(pr->id);
910         on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
911 #endif
912
913         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
914                 struct acpi_processor_cx *cx = &pr->power.states[i];
915
916                 switch (cx->type) {
917                 case ACPI_STATE_C1:
918                         cx->valid = 1;
919                         break;
920
921                 case ACPI_STATE_C2:
922                         acpi_processor_power_verify_c2(cx);
923 #ifdef ARCH_APICTIMER_STOPS_ON_C3
924                         /* Some AMD systems fake C3 as C2, but still
925                            have timer troubles */
926                         if (cx->valid && 
927                                 boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
928                                 timer_broadcast++;
929 #endif
930                         break;
931
932                 case ACPI_STATE_C3:
933                         acpi_processor_power_verify_c3(pr, cx);
934 #ifdef ARCH_APICTIMER_STOPS_ON_C3
935                         if (cx->valid)
936                                 timer_broadcast++;
937 #endif
938                         break;
939                 }
940
941                 if (cx->valid)
942                         working++;
943         }
944
945 #ifdef ARCH_APICTIMER_STOPS_ON_C3
946         if (timer_broadcast)
947                 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
948 #endif
949
950         return (working);
951 }
952
953 static int acpi_processor_get_power_info(struct acpi_processor *pr)
954 {
955         unsigned int i;
956         int result;
957
958
959         /* NOTE: the idle thread may not be running while calling
960          * this function */
961
962         /* Zero initialize all the C-states info. */
963         memset(pr->power.states, 0, sizeof(pr->power.states));
964
965         result = acpi_processor_get_power_info_cst(pr);
966         if (result == -ENODEV)
967                 result = acpi_processor_get_power_info_fadt(pr);
968
969         if (result)
970                 return result;
971
972         acpi_processor_get_power_info_default(pr);
973
974         pr->power.count = acpi_processor_power_verify(pr);
975
976         /*
977          * Set Default Policy
978          * ------------------
979          * Now that we know which states are supported, set the default
980          * policy.  Note that this policy can be changed dynamically
981          * (e.g. encourage deeper sleeps to conserve battery life when
982          * not on AC).
983          */
984         result = acpi_processor_set_power_policy(pr);
985         if (result)
986                 return result;
987
988         /*
989          * if one state of type C2 or C3 is available, mark this
990          * CPU as being "idle manageable"
991          */
992         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
993                 if (pr->power.states[i].valid) {
994                         pr->power.count = i;
995                         if (pr->power.states[i].type >= ACPI_STATE_C2)
996                                 pr->flags.power = 1;
997                 }
998         }
999
1000         return 0;
1001 }
1002
1003 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1004 {
1005         int result = 0;
1006
1007
1008         if (!pr)
1009                 return -EINVAL;
1010
1011         if (nocst) {
1012                 return -ENODEV;
1013         }
1014
1015         if (!pr->flags.power_setup_done)
1016                 return -ENODEV;
1017
1018         /* Fall back to the default idle loop */
1019         pm_idle = pm_idle_save;
1020         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
1021
1022         pr->flags.power = 0;
1023         result = acpi_processor_get_power_info(pr);
1024         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1025                 pm_idle = acpi_processor_idle;
1026
1027         return result;
1028 }
1029
1030 /* proc interface */
1031
1032 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1033 {
1034         struct acpi_processor *pr = seq->private;
1035         unsigned int i;
1036
1037
1038         if (!pr)
1039                 goto end;
1040
1041         seq_printf(seq, "active state:            C%zd\n"
1042                    "max_cstate:              C%d\n"
1043                    "bus master activity:     %08x\n"
1044                    "maximum allowed latency: %d usec\n",
1045                    pr->power.state ? pr->power.state - pr->power.states : 0,
1046                    max_cstate, (unsigned)pr->power.bm_activity,
1047                    system_latency_constraint());
1048
1049         seq_puts(seq, "states:\n");
1050
1051         for (i = 1; i <= pr->power.count; i++) {
1052                 seq_printf(seq, "   %cC%d:                  ",
1053                            (&pr->power.states[i] ==
1054                             pr->power.state ? '*' : ' '), i);
1055
1056                 if (!pr->power.states[i].valid) {
1057                         seq_puts(seq, "<not supported>\n");
1058                         continue;
1059                 }
1060
1061                 switch (pr->power.states[i].type) {
1062                 case ACPI_STATE_C1:
1063                         seq_printf(seq, "type[C1] ");
1064                         break;
1065                 case ACPI_STATE_C2:
1066                         seq_printf(seq, "type[C2] ");
1067                         break;
1068                 case ACPI_STATE_C3:
1069                         seq_printf(seq, "type[C3] ");
1070                         break;
1071                 default:
1072                         seq_printf(seq, "type[--] ");
1073                         break;
1074                 }
1075
1076                 if (pr->power.states[i].promotion.state)
1077                         seq_printf(seq, "promotion[C%zd] ",
1078                                    (pr->power.states[i].promotion.state -
1079                                     pr->power.states));
1080                 else
1081                         seq_puts(seq, "promotion[--] ");
1082
1083                 if (pr->power.states[i].demotion.state)
1084                         seq_printf(seq, "demotion[C%zd] ",
1085                                    (pr->power.states[i].demotion.state -
1086                                     pr->power.states));
1087                 else
1088                         seq_puts(seq, "demotion[--] ");
1089
1090                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1091                            pr->power.states[i].latency,
1092                            pr->power.states[i].usage,
1093                            pr->power.states[i].time);
1094         }
1095
1096       end:
1097         return 0;
1098 }
1099
1100 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1101 {
1102         return single_open(file, acpi_processor_power_seq_show,
1103                            PDE(inode)->data);
1104 }
1105
1106 static const struct file_operations acpi_processor_power_fops = {
1107         .open = acpi_processor_power_open_fs,
1108         .read = seq_read,
1109         .llseek = seq_lseek,
1110         .release = single_release,
1111 };
1112
1113 #ifdef CONFIG_SMP
1114 static void smp_callback(void *v)
1115 {
1116         /* we already woke the CPU up, nothing more to do */
1117 }
1118
1119 /*
1120  * This function gets called when a part of the kernel has a new latency
1121  * requirement.  This means we need to get all processors out of their C-state,
1122  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1123  * wakes them all right up.
1124  */
1125 static int acpi_processor_latency_notify(struct notifier_block *b,
1126                 unsigned long l, void *v)
1127 {
1128         smp_call_function(smp_callback, NULL, 0, 1);
1129         return NOTIFY_OK;
1130 }
1131
1132 static struct notifier_block acpi_processor_latency_notifier = {
1133         .notifier_call = acpi_processor_latency_notify,
1134 };
1135 #endif
1136
1137 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1138                               struct acpi_device *device)
1139 {
1140         acpi_status status = 0;
1141         static int first_run;
1142         struct proc_dir_entry *entry = NULL;
1143         unsigned int i;
1144
1145
1146         if (!first_run) {
1147                 dmi_check_system(processor_power_dmi_table);
1148                 if (max_cstate < ACPI_C_STATES_MAX)
1149                         printk(KERN_NOTICE
1150                                "ACPI: processor limited to max C-state %d\n",
1151                                max_cstate);
1152                 first_run++;
1153 #ifdef CONFIG_SMP
1154                 register_latency_notifier(&acpi_processor_latency_notifier);
1155 #endif
1156         }
1157
1158         if (!pr)
1159                 return -EINVAL;
1160
1161         if (acpi_gbl_FADT.cst_control && !nocst) {
1162                 status =
1163                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1164                 if (ACPI_FAILURE(status)) {
1165                         ACPI_EXCEPTION((AE_INFO, status,
1166                                         "Notifying BIOS of _CST ability failed"));
1167                 }
1168         }
1169
1170         acpi_processor_get_power_info(pr);
1171
1172         /*
1173          * Install the idle handler if processor power management is supported.
1174          * Note that we use previously set idle handler will be used on
1175          * platforms that only support C1.
1176          */
1177         if ((pr->flags.power) && (!boot_option_idle_override)) {
1178                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1179                 for (i = 1; i <= pr->power.count; i++)
1180                         if (pr->power.states[i].valid)
1181                                 printk(" C%d[C%d]", i,
1182                                        pr->power.states[i].type);
1183                 printk(")\n");
1184
1185                 if (pr->id == 0) {
1186                         pm_idle_save = pm_idle;
1187                         pm_idle = acpi_processor_idle;
1188                 }
1189         }
1190
1191         /* 'power' [R] */
1192         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1193                                   S_IRUGO, acpi_device_dir(device));
1194         if (!entry)
1195                 return -EIO;
1196         else {
1197                 entry->proc_fops = &acpi_processor_power_fops;
1198                 entry->data = acpi_driver_data(device);
1199                 entry->owner = THIS_MODULE;
1200         }
1201
1202         pr->flags.power_setup_done = 1;
1203
1204         return 0;
1205 }
1206
1207 int acpi_processor_power_exit(struct acpi_processor *pr,
1208                               struct acpi_device *device)
1209 {
1210
1211         pr->flags.power_setup_done = 0;
1212
1213         if (acpi_device_dir(device))
1214                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1215                                   acpi_device_dir(device));
1216
1217         /* Unregister the idle handler when processor #0 is removed. */
1218         if (pr->id == 0) {
1219                 pm_idle = pm_idle_save;
1220
1221                 /*
1222                  * We are about to unload the current idle thread pm callback
1223                  * (pm_idle), Wait for all processors to update cached/local
1224                  * copies of pm_idle before proceeding.
1225                  */
1226                 cpu_idle_wait();
1227 #ifdef CONFIG_SMP
1228                 unregister_latency_notifier(&acpi_processor_latency_notifier);
1229 #endif
1230         }
1231
1232         return 0;
1233 }