Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6
[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 #include <linux/clockchips.h>
43
44 /*
45  * Include the apic definitions for x86 to have the APIC timer related defines
46  * available also for UP (on SMP it gets magically included via linux/smp.h).
47  * asm/acpi.h is not an option, as it would require more include magic. Also
48  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
49  */
50 #ifdef CONFIG_X86
51 #include <asm/apic.h>
52 #endif
53
54 #include <asm/io.h>
55 #include <asm/uaccess.h>
56
57 #include <acpi/acpi_bus.h>
58 #include <acpi/processor.h>
59
60 #define ACPI_PROCESSOR_COMPONENT        0x01000000
61 #define ACPI_PROCESSOR_CLASS            "processor"
62 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
63 ACPI_MODULE_NAME("processor_idle");
64 #define ACPI_PROCESSOR_FILE_POWER       "power"
65 #define US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
66 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
67 #define C2_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
68 #define C3_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
69 static void (*pm_idle_save) (void) __read_mostly;
70 module_param(max_cstate, uint, 0644);
71
72 static unsigned int nocst __read_mostly;
73 module_param(nocst, uint, 0000);
74
75 /*
76  * bm_history -- bit-mask with a bit per jiffy of bus-master activity
77  * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
78  * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
79  * 100 HZ: 0x0000000F: 4 jiffies = 40ms
80  * reduce history for more aggressive entry into C3
81  */
82 static unsigned int bm_history __read_mostly =
83     (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
84 module_param(bm_history, uint, 0644);
85 /* --------------------------------------------------------------------------
86                                 Power Management
87    -------------------------------------------------------------------------- */
88
89 /*
90  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
91  * For now disable this. Probably a bug somewhere else.
92  *
93  * To skip this limit, boot/load with a large max_cstate limit.
94  */
95 static int set_max_cstate(const struct dmi_system_id *id)
96 {
97         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
98                 return 0;
99
100         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
101                " Override with \"processor.max_cstate=%d\"\n", id->ident,
102                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
103
104         max_cstate = (long)id->driver_data;
105
106         return 0;
107 }
108
109 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
110    callers to only run once -AK */
111 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
112         { set_max_cstate, "IBM ThinkPad R40e", {
113           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
114           DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
115         { set_max_cstate, "IBM ThinkPad R40e", {
116           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
117           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
118         { set_max_cstate, "IBM ThinkPad R40e", {
119           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
120           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
121         { set_max_cstate, "IBM ThinkPad R40e", {
122           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
123           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
124         { set_max_cstate, "IBM ThinkPad R40e", {
125           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
126           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
127         { set_max_cstate, "IBM ThinkPad R40e", {
128           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
129           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
130         { set_max_cstate, "IBM ThinkPad R40e", {
131           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
132           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
133         { set_max_cstate, "IBM ThinkPad R40e", {
134           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
135           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
136         { set_max_cstate, "IBM ThinkPad R40e", {
137           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
138           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
139         { set_max_cstate, "IBM ThinkPad R40e", {
140           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
141           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
142         { set_max_cstate, "IBM ThinkPad R40e", {
143           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
144           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
145         { set_max_cstate, "IBM ThinkPad R40e", {
146           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
147           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
148         { set_max_cstate, "IBM ThinkPad R40e", {
149           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
150           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
151         { set_max_cstate, "IBM ThinkPad R40e", {
152           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
153           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
154         { set_max_cstate, "IBM ThinkPad R40e", {
155           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
156           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
157         { set_max_cstate, "IBM ThinkPad R40e", {
158           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
159           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
160         { set_max_cstate, "Medion 41700", {
161           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
162           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
163         { set_max_cstate, "Clevo 5600D", {
164           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
165           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
166          (void *)2},
167         {},
168 };
169
170 static inline u32 ticks_elapsed(u32 t1, u32 t2)
171 {
172         if (t2 >= t1)
173                 return (t2 - t1);
174         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
175                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
176         else
177                 return ((0xFFFFFFFF - t1) + t2);
178 }
179
180 static void
181 acpi_processor_power_activate(struct acpi_processor *pr,
182                               struct acpi_processor_cx *new)
183 {
184         struct acpi_processor_cx *old;
185
186         if (!pr || !new)
187                 return;
188
189         old = pr->power.state;
190
191         if (old)
192                 old->promotion.count = 0;
193         new->demotion.count = 0;
194
195         /* Cleanup from old state. */
196         if (old) {
197                 switch (old->type) {
198                 case ACPI_STATE_C3:
199                         /* Disable bus master reload */
200                         if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
201                                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
202                         break;
203                 }
204         }
205
206         /* Prepare to use new state. */
207         switch (new->type) {
208         case ACPI_STATE_C3:
209                 /* Enable bus master reload */
210                 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
211                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
212                 break;
213         }
214
215         pr->power.state = new;
216
217         return;
218 }
219
220 static void acpi_safe_halt(void)
221 {
222         current_thread_info()->status &= ~TS_POLLING;
223         /*
224          * TS_POLLING-cleared state must be visible before we
225          * test NEED_RESCHED:
226          */
227         smp_mb();
228         if (!need_resched())
229                 safe_halt();
230         current_thread_info()->status |= TS_POLLING;
231 }
232
233 static atomic_t c3_cpu_count;
234
235 /* Common C-state entry for C2, C3, .. */
236 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
237 {
238         if (cstate->space_id == ACPI_CSTATE_FFH) {
239                 /* Call into architectural FFH based C-state */
240                 acpi_processor_ffh_cstate_enter(cstate);
241         } else {
242                 int unused;
243                 /* IO port based C-state */
244                 inb(cstate->address);
245                 /* Dummy wait op - must do something useless after P_LVL2 read
246                    because chipsets cannot guarantee that STPCLK# signal
247                    gets asserted in time to freeze execution properly. */
248                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
249         }
250 }
251
252 #ifdef ARCH_APICTIMER_STOPS_ON_C3
253
254 /*
255  * Some BIOS implementations switch to C3 in the published C2 state.
256  * This seems to be a common problem on AMD boxen, but other vendors
257  * are affected too. We pick the most conservative approach: we assume
258  * that the local APIC stops in both C2 and C3.
259  */
260 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
261                                    struct acpi_processor_cx *cx)
262 {
263         struct acpi_processor_power *pwr = &pr->power;
264         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
265
266         /*
267          * Check, if one of the previous states already marked the lapic
268          * unstable
269          */
270         if (pwr->timer_broadcast_on_state < state)
271                 return;
272
273         if (cx->type >= type)
274                 pr->power.timer_broadcast_on_state = state;
275 }
276
277 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
278 {
279         unsigned long reason;
280
281         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
282                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
283
284         clockevents_notify(reason, &pr->id);
285 }
286
287 /* Power(C) State timer broadcast control */
288 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
289                                        struct acpi_processor_cx *cx,
290                                        int broadcast)
291 {
292         int state = cx - pr->power.states;
293
294         if (state >= pr->power.timer_broadcast_on_state) {
295                 unsigned long reason;
296
297                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
298                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
299                 clockevents_notify(reason, &pr->id);
300         }
301 }
302
303 #else
304
305 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
306                                    struct acpi_processor_cx *cstate) { }
307 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
308 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
309                                        struct acpi_processor_cx *cx,
310                                        int broadcast)
311 {
312 }
313
314 #endif
315
316 /*
317  * Suspend / resume control
318  */
319 static int acpi_idle_suspend;
320
321 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
322 {
323         acpi_idle_suspend = 1;
324         return 0;
325 }
326
327 int acpi_processor_resume(struct acpi_device * device)
328 {
329         acpi_idle_suspend = 0;
330         return 0;
331 }
332
333 static void acpi_processor_idle(void)
334 {
335         struct acpi_processor *pr = NULL;
336         struct acpi_processor_cx *cx = NULL;
337         struct acpi_processor_cx *next_state = NULL;
338         int sleep_ticks = 0;
339         u32 t1, t2 = 0;
340
341         /*
342          * Interrupts must be disabled during bus mastering calculations and
343          * for C2/C3 transitions.
344          */
345         local_irq_disable();
346
347         pr = processors[smp_processor_id()];
348         if (!pr) {
349                 local_irq_enable();
350                 return;
351         }
352
353         /*
354          * Check whether we truly need to go idle, or should
355          * reschedule:
356          */
357         if (unlikely(need_resched())) {
358                 local_irq_enable();
359                 return;
360         }
361
362         cx = pr->power.state;
363         if (!cx || acpi_idle_suspend) {
364                 if (pm_idle_save)
365                         pm_idle_save();
366                 else
367                         acpi_safe_halt();
368                 return;
369         }
370
371         /*
372          * Check BM Activity
373          * -----------------
374          * Check for bus mastering activity (if required), record, and check
375          * for demotion.
376          */
377         if (pr->flags.bm_check) {
378                 u32 bm_status = 0;
379                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
380
381                 if (diff > 31)
382                         diff = 31;
383
384                 pr->power.bm_activity <<= diff;
385
386                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
387                 if (bm_status) {
388                         pr->power.bm_activity |= 0x1;
389                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
390                 }
391                 /*
392                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
393                  * the true state of bus mastering activity; forcing us to
394                  * manually check the BMIDEA bit of each IDE channel.
395                  */
396                 else if (errata.piix4.bmisx) {
397                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
398                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
399                                 pr->power.bm_activity |= 0x1;
400                 }
401
402                 pr->power.bm_check_timestamp = jiffies;
403
404                 /*
405                  * If bus mastering is or was active this jiffy, demote
406                  * to avoid a faulty transition.  Note that the processor
407                  * won't enter a low-power state during this call (to this
408                  * function) but should upon the next.
409                  *
410                  * TBD: A better policy might be to fallback to the demotion
411                  *      state (use it for this quantum only) istead of
412                  *      demoting -- and rely on duration as our sole demotion
413                  *      qualification.  This may, however, introduce DMA
414                  *      issues (e.g. floppy DMA transfer overrun/underrun).
415                  */
416                 if ((pr->power.bm_activity & 0x1) &&
417                     cx->demotion.threshold.bm) {
418                         local_irq_enable();
419                         next_state = cx->demotion.state;
420                         goto end;
421                 }
422         }
423
424 #ifdef CONFIG_HOTPLUG_CPU
425         /*
426          * Check for P_LVL2_UP flag before entering C2 and above on
427          * an SMP system. We do it here instead of doing it at _CST/P_LVL
428          * detection phase, to work cleanly with logical CPU hotplug.
429          */
430         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
431             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
432                 cx = &pr->power.states[ACPI_STATE_C1];
433 #endif
434
435         /*
436          * Sleep:
437          * ------
438          * Invoke the current Cx state to put the processor to sleep.
439          */
440         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
441                 current_thread_info()->status &= ~TS_POLLING;
442                 /*
443                  * TS_POLLING-cleared state must be visible before we
444                  * test NEED_RESCHED:
445                  */
446                 smp_mb();
447                 if (need_resched()) {
448                         current_thread_info()->status |= TS_POLLING;
449                         local_irq_enable();
450                         return;
451                 }
452         }
453
454         switch (cx->type) {
455
456         case ACPI_STATE_C1:
457                 /*
458                  * Invoke C1.
459                  * Use the appropriate idle routine, the one that would
460                  * be used without acpi C-states.
461                  */
462                 if (pm_idle_save)
463                         pm_idle_save();
464                 else
465                         acpi_safe_halt();
466
467                 /*
468                  * TBD: Can't get time duration while in C1, as resumes
469                  *      go to an ISR rather than here.  Need to instrument
470                  *      base interrupt handler.
471                  *
472                  * Note: the TSC better not stop in C1, sched_clock() will
473                  *       skew otherwise.
474                  */
475                 sleep_ticks = 0xFFFFFFFF;
476                 break;
477
478         case ACPI_STATE_C2:
479                 /* Get start time (ticks) */
480                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
481                 /* Tell the scheduler that we are going deep-idle: */
482                 sched_clock_idle_sleep_event();
483                 /* Invoke C2 */
484                 acpi_state_timer_broadcast(pr, cx, 1);
485                 acpi_cstate_enter(cx);
486                 /* Get end time (ticks) */
487                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
488
489 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
490                 /* TSC halts in C2, so notify users */
491                 mark_tsc_unstable("possible TSC halt in C2");
492 #endif
493                 /* Compute time (ticks) that we were actually asleep */
494                 sleep_ticks = ticks_elapsed(t1, t2);
495
496                 /* Tell the scheduler how much we idled: */
497                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
498
499                 /* Re-enable interrupts */
500                 local_irq_enable();
501                 /* Do not account our idle-switching overhead: */
502                 sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
503
504                 current_thread_info()->status |= TS_POLLING;
505                 acpi_state_timer_broadcast(pr, cx, 0);
506                 break;
507
508         case ACPI_STATE_C3:
509                 /*
510                  * disable bus master
511                  * bm_check implies we need ARB_DIS
512                  * !bm_check implies we need cache flush
513                  * bm_control implies whether we can do ARB_DIS
514                  *
515                  * That leaves a case where bm_check is set and bm_control is
516                  * not set. In that case we cannot do much, we enter C3
517                  * without doing anything.
518                  */
519                 if (pr->flags.bm_check && pr->flags.bm_control) {
520                         if (atomic_inc_return(&c3_cpu_count) ==
521                             num_online_cpus()) {
522                                 /*
523                                  * All CPUs are trying to go to C3
524                                  * Disable bus master arbitration
525                                  */
526                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
527                         }
528                 } else if (!pr->flags.bm_check) {
529                         /* SMP with no shared cache... Invalidate cache  */
530                         ACPI_FLUSH_CPU_CACHE();
531                 }
532
533                 /* Get start time (ticks) */
534                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
535                 /* Invoke C3 */
536                 acpi_state_timer_broadcast(pr, cx, 1);
537                 /* Tell the scheduler that we are going deep-idle: */
538                 sched_clock_idle_sleep_event();
539                 acpi_cstate_enter(cx);
540                 /* Get end time (ticks) */
541                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
542                 if (pr->flags.bm_check && pr->flags.bm_control) {
543                         /* Enable bus master arbitration */
544                         atomic_dec(&c3_cpu_count);
545                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
546                 }
547
548 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
549                 /* TSC halts in C3, so notify users */
550                 mark_tsc_unstable("TSC halts in C3");
551 #endif
552                 /* Compute time (ticks) that we were actually asleep */
553                 sleep_ticks = ticks_elapsed(t1, t2);
554                 /* Tell the scheduler how much we idled: */
555                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
556
557                 /* Re-enable interrupts */
558                 local_irq_enable();
559                 /* Do not account our idle-switching overhead: */
560                 sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
561
562                 current_thread_info()->status |= TS_POLLING;
563                 acpi_state_timer_broadcast(pr, cx, 0);
564                 break;
565
566         default:
567                 local_irq_enable();
568                 return;
569         }
570         cx->usage++;
571         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
572                 cx->time += sleep_ticks;
573
574         next_state = pr->power.state;
575
576 #ifdef CONFIG_HOTPLUG_CPU
577         /* Don't do promotion/demotion */
578         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
579             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
580                 next_state = cx;
581                 goto end;
582         }
583 #endif
584
585         /*
586          * Promotion?
587          * ----------
588          * Track the number of longs (time asleep is greater than threshold)
589          * and promote when the count threshold is reached.  Note that bus
590          * mastering activity may prevent promotions.
591          * Do not promote above max_cstate.
592          */
593         if (cx->promotion.state &&
594             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
595                 if (sleep_ticks > cx->promotion.threshold.ticks &&
596                   cx->promotion.state->latency <= system_latency_constraint()) {
597                         cx->promotion.count++;
598                         cx->demotion.count = 0;
599                         if (cx->promotion.count >=
600                             cx->promotion.threshold.count) {
601                                 if (pr->flags.bm_check) {
602                                         if (!
603                                             (pr->power.bm_activity & cx->
604                                              promotion.threshold.bm)) {
605                                                 next_state =
606                                                     cx->promotion.state;
607                                                 goto end;
608                                         }
609                                 } else {
610                                         next_state = cx->promotion.state;
611                                         goto end;
612                                 }
613                         }
614                 }
615         }
616
617         /*
618          * Demotion?
619          * ---------
620          * Track the number of shorts (time asleep is less than time threshold)
621          * and demote when the usage threshold is reached.
622          */
623         if (cx->demotion.state) {
624                 if (sleep_ticks < cx->demotion.threshold.ticks) {
625                         cx->demotion.count++;
626                         cx->promotion.count = 0;
627                         if (cx->demotion.count >= cx->demotion.threshold.count) {
628                                 next_state = cx->demotion.state;
629                                 goto end;
630                         }
631                 }
632         }
633
634       end:
635         /*
636          * Demote if current state exceeds max_cstate
637          * or if the latency of the current state is unacceptable
638          */
639         if ((pr->power.state - pr->power.states) > max_cstate ||
640                 pr->power.state->latency > system_latency_constraint()) {
641                 if (cx->demotion.state)
642                         next_state = cx->demotion.state;
643         }
644
645         /*
646          * New Cx State?
647          * -------------
648          * If we're going to start using a new Cx state we must clean up
649          * from the previous and prepare to use the new.
650          */
651         if (next_state != pr->power.state)
652                 acpi_processor_power_activate(pr, next_state);
653 }
654
655 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
656 {
657         unsigned int i;
658         unsigned int state_is_set = 0;
659         struct acpi_processor_cx *lower = NULL;
660         struct acpi_processor_cx *higher = NULL;
661         struct acpi_processor_cx *cx;
662
663
664         if (!pr)
665                 return -EINVAL;
666
667         /*
668          * This function sets the default Cx state policy (OS idle handler).
669          * Our scheme is to promote quickly to C2 but more conservatively
670          * to C3.  We're favoring C2  for its characteristics of low latency
671          * (quick response), good power savings, and ability to allow bus
672          * mastering activity.  Note that the Cx state policy is completely
673          * customizable and can be altered dynamically.
674          */
675
676         /* startup state */
677         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
678                 cx = &pr->power.states[i];
679                 if (!cx->valid)
680                         continue;
681
682                 if (!state_is_set)
683                         pr->power.state = cx;
684                 state_is_set++;
685                 break;
686         }
687
688         if (!state_is_set)
689                 return -ENODEV;
690
691         /* demotion */
692         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
693                 cx = &pr->power.states[i];
694                 if (!cx->valid)
695                         continue;
696
697                 if (lower) {
698                         cx->demotion.state = lower;
699                         cx->demotion.threshold.ticks = cx->latency_ticks;
700                         cx->demotion.threshold.count = 1;
701                         if (cx->type == ACPI_STATE_C3)
702                                 cx->demotion.threshold.bm = bm_history;
703                 }
704
705                 lower = cx;
706         }
707
708         /* promotion */
709         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
710                 cx = &pr->power.states[i];
711                 if (!cx->valid)
712                         continue;
713
714                 if (higher) {
715                         cx->promotion.state = higher;
716                         cx->promotion.threshold.ticks = cx->latency_ticks;
717                         if (cx->type >= ACPI_STATE_C2)
718                                 cx->promotion.threshold.count = 4;
719                         else
720                                 cx->promotion.threshold.count = 10;
721                         if (higher->type == ACPI_STATE_C3)
722                                 cx->promotion.threshold.bm = bm_history;
723                 }
724
725                 higher = cx;
726         }
727
728         return 0;
729 }
730
731 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
732 {
733
734         if (!pr)
735                 return -EINVAL;
736
737         if (!pr->pblk)
738                 return -ENODEV;
739
740         /* if info is obtained from pblk/fadt, type equals state */
741         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
742         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
743
744 #ifndef CONFIG_HOTPLUG_CPU
745         /*
746          * Check for P_LVL2_UP flag before entering C2 and above on
747          * an SMP system. 
748          */
749         if ((num_online_cpus() > 1) &&
750             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
751                 return -ENODEV;
752 #endif
753
754         /* determine C2 and C3 address from pblk */
755         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
756         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
757
758         /* determine latencies from FADT */
759         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
760         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
761
762         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
763                           "lvl2[0x%08x] lvl3[0x%08x]\n",
764                           pr->power.states[ACPI_STATE_C2].address,
765                           pr->power.states[ACPI_STATE_C3].address));
766
767         return 0;
768 }
769
770 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
771 {
772         if (!pr->power.states[ACPI_STATE_C1].valid) {
773                 /* set the first C-State to C1 */
774                 /* all processors need to support C1 */
775                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
776                 pr->power.states[ACPI_STATE_C1].valid = 1;
777         }
778         /* the C0 state only exists as a filler in our array */
779         pr->power.states[ACPI_STATE_C0].valid = 1;
780         return 0;
781 }
782
783 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
784 {
785         acpi_status status = 0;
786         acpi_integer count;
787         int current_count;
788         int i;
789         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
790         union acpi_object *cst;
791
792
793         if (nocst)
794                 return -ENODEV;
795
796         current_count = 0;
797
798         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
799         if (ACPI_FAILURE(status)) {
800                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
801                 return -ENODEV;
802         }
803
804         cst = buffer.pointer;
805
806         /* There must be at least 2 elements */
807         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
808                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
809                 status = -EFAULT;
810                 goto end;
811         }
812
813         count = cst->package.elements[0].integer.value;
814
815         /* Validate number of power states. */
816         if (count < 1 || count != cst->package.count - 1) {
817                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
818                 status = -EFAULT;
819                 goto end;
820         }
821
822         /* Tell driver that at least _CST is supported. */
823         pr->flags.has_cst = 1;
824
825         for (i = 1; i <= count; i++) {
826                 union acpi_object *element;
827                 union acpi_object *obj;
828                 struct acpi_power_register *reg;
829                 struct acpi_processor_cx cx;
830
831                 memset(&cx, 0, sizeof(cx));
832
833                 element = &(cst->package.elements[i]);
834                 if (element->type != ACPI_TYPE_PACKAGE)
835                         continue;
836
837                 if (element->package.count != 4)
838                         continue;
839
840                 obj = &(element->package.elements[0]);
841
842                 if (obj->type != ACPI_TYPE_BUFFER)
843                         continue;
844
845                 reg = (struct acpi_power_register *)obj->buffer.pointer;
846
847                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
848                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
849                         continue;
850
851                 /* There should be an easy way to extract an integer... */
852                 obj = &(element->package.elements[1]);
853                 if (obj->type != ACPI_TYPE_INTEGER)
854                         continue;
855
856                 cx.type = obj->integer.value;
857                 /*
858                  * Some buggy BIOSes won't list C1 in _CST -
859                  * Let acpi_processor_get_power_info_default() handle them later
860                  */
861                 if (i == 1 && cx.type != ACPI_STATE_C1)
862                         current_count++;
863
864                 cx.address = reg->address;
865                 cx.index = current_count + 1;
866
867                 cx.space_id = ACPI_CSTATE_SYSTEMIO;
868                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
869                         if (acpi_processor_ffh_cstate_probe
870                                         (pr->id, &cx, reg) == 0) {
871                                 cx.space_id = ACPI_CSTATE_FFH;
872                         } else if (cx.type != ACPI_STATE_C1) {
873                                 /*
874                                  * C1 is a special case where FIXED_HARDWARE
875                                  * can be handled in non-MWAIT way as well.
876                                  * In that case, save this _CST entry info.
877                                  * That is, we retain space_id of SYSTEM_IO for
878                                  * halt based C1.
879                                  * Otherwise, ignore this info and continue.
880                                  */
881                                 continue;
882                         }
883                 }
884
885                 obj = &(element->package.elements[2]);
886                 if (obj->type != ACPI_TYPE_INTEGER)
887                         continue;
888
889                 cx.latency = obj->integer.value;
890
891                 obj = &(element->package.elements[3]);
892                 if (obj->type != ACPI_TYPE_INTEGER)
893                         continue;
894
895                 cx.power = obj->integer.value;
896
897                 current_count++;
898                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
899
900                 /*
901                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
902                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
903                  */
904                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
905                         printk(KERN_WARNING
906                                "Limiting number of power states to max (%d)\n",
907                                ACPI_PROCESSOR_MAX_POWER);
908                         printk(KERN_WARNING
909                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
910                         break;
911                 }
912         }
913
914         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
915                           current_count));
916
917         /* Validate number of power states discovered */
918         if (current_count < 2)
919                 status = -EFAULT;
920
921       end:
922         kfree(buffer.pointer);
923
924         return status;
925 }
926
927 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
928 {
929
930         if (!cx->address)
931                 return;
932
933         /*
934          * C2 latency must be less than or equal to 100
935          * microseconds.
936          */
937         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
938                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
939                                   "latency too large [%d]\n", cx->latency));
940                 return;
941         }
942
943         /*
944          * Otherwise we've met all of our C2 requirements.
945          * Normalize the C2 latency to expidite policy
946          */
947         cx->valid = 1;
948         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
949
950         return;
951 }
952
953 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
954                                            struct acpi_processor_cx *cx)
955 {
956         static int bm_check_flag;
957
958
959         if (!cx->address)
960                 return;
961
962         /*
963          * C3 latency must be less than or equal to 1000
964          * microseconds.
965          */
966         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
967                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
968                                   "latency too large [%d]\n", cx->latency));
969                 return;
970         }
971
972         /*
973          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
974          * DMA transfers are used by any ISA device to avoid livelock.
975          * Note that we could disable Type-F DMA (as recommended by
976          * the erratum), but this is known to disrupt certain ISA
977          * devices thus we take the conservative approach.
978          */
979         else if (errata.piix4.fdma) {
980                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
981                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
982                 return;
983         }
984
985         /* All the logic here assumes flags.bm_check is same across all CPUs */
986         if (!bm_check_flag) {
987                 /* Determine whether bm_check is needed based on CPU  */
988                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
989                 bm_check_flag = pr->flags.bm_check;
990         } else {
991                 pr->flags.bm_check = bm_check_flag;
992         }
993
994         if (pr->flags.bm_check) {
995                 if (!pr->flags.bm_control) {
996                         if (pr->flags.has_cst != 1) {
997                                 /* bus mastering control is necessary */
998                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
999                                         "C3 support requires BM control\n"));
1000                                 return;
1001                         } else {
1002                                 /* Here we enter C3 without bus mastering */
1003                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1004                                         "C3 support without BM control\n"));
1005                         }
1006                 }
1007         } else {
1008                 /*
1009                  * WBINVD should be set in fadt, for C3 state to be
1010                  * supported on when bm_check is not required.
1011                  */
1012                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
1013                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1014                                           "Cache invalidation should work properly"
1015                                           " for C3 to be enabled on SMP systems\n"));
1016                         return;
1017                 }
1018                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
1019         }
1020
1021         /*
1022          * Otherwise we've met all of our C3 requirements.
1023          * Normalize the C3 latency to expidite policy.  Enable
1024          * checking of bus mastering status (bm_check) so we can
1025          * use this in our C3 policy
1026          */
1027         cx->valid = 1;
1028         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1029
1030         return;
1031 }
1032
1033 static int acpi_processor_power_verify(struct acpi_processor *pr)
1034 {
1035         unsigned int i;
1036         unsigned int working = 0;
1037
1038         pr->power.timer_broadcast_on_state = INT_MAX;
1039
1040         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1041                 struct acpi_processor_cx *cx = &pr->power.states[i];
1042
1043                 switch (cx->type) {
1044                 case ACPI_STATE_C1:
1045                         cx->valid = 1;
1046                         break;
1047
1048                 case ACPI_STATE_C2:
1049                         acpi_processor_power_verify_c2(cx);
1050                         if (cx->valid)
1051                                 acpi_timer_check_state(i, pr, cx);
1052                         break;
1053
1054                 case ACPI_STATE_C3:
1055                         acpi_processor_power_verify_c3(pr, cx);
1056                         if (cx->valid)
1057                                 acpi_timer_check_state(i, pr, cx);
1058                         break;
1059                 }
1060
1061                 if (cx->valid)
1062                         working++;
1063         }
1064
1065         acpi_propagate_timer_broadcast(pr);
1066
1067         return (working);
1068 }
1069
1070 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1071 {
1072         unsigned int i;
1073         int result;
1074
1075
1076         /* NOTE: the idle thread may not be running while calling
1077          * this function */
1078
1079         /* Zero initialize all the C-states info. */
1080         memset(pr->power.states, 0, sizeof(pr->power.states));
1081
1082         result = acpi_processor_get_power_info_cst(pr);
1083         if (result == -ENODEV)
1084                 result = acpi_processor_get_power_info_fadt(pr);
1085
1086         if (result)
1087                 return result;
1088
1089         acpi_processor_get_power_info_default(pr);
1090
1091         pr->power.count = acpi_processor_power_verify(pr);
1092
1093         /*
1094          * Set Default Policy
1095          * ------------------
1096          * Now that we know which states are supported, set the default
1097          * policy.  Note that this policy can be changed dynamically
1098          * (e.g. encourage deeper sleeps to conserve battery life when
1099          * not on AC).
1100          */
1101         result = acpi_processor_set_power_policy(pr);
1102         if (result)
1103                 return result;
1104
1105         /*
1106          * if one state of type C2 or C3 is available, mark this
1107          * CPU as being "idle manageable"
1108          */
1109         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1110                 if (pr->power.states[i].valid) {
1111                         pr->power.count = i;
1112                         if (pr->power.states[i].type >= ACPI_STATE_C2)
1113                                 pr->flags.power = 1;
1114                 }
1115         }
1116
1117         return 0;
1118 }
1119
1120 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1121 {
1122         int result = 0;
1123
1124
1125         if (!pr)
1126                 return -EINVAL;
1127
1128         if (nocst) {
1129                 return -ENODEV;
1130         }
1131
1132         if (!pr->flags.power_setup_done)
1133                 return -ENODEV;
1134
1135         /* Fall back to the default idle loop */
1136         pm_idle = pm_idle_save;
1137         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
1138
1139         pr->flags.power = 0;
1140         result = acpi_processor_get_power_info(pr);
1141         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1142                 pm_idle = acpi_processor_idle;
1143
1144         return result;
1145 }
1146
1147 /* proc interface */
1148
1149 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1150 {
1151         struct acpi_processor *pr = seq->private;
1152         unsigned int i;
1153
1154
1155         if (!pr)
1156                 goto end;
1157
1158         seq_printf(seq, "active state:            C%zd\n"
1159                    "max_cstate:              C%d\n"
1160                    "bus master activity:     %08x\n"
1161                    "maximum allowed latency: %d usec\n",
1162                    pr->power.state ? pr->power.state - pr->power.states : 0,
1163                    max_cstate, (unsigned)pr->power.bm_activity,
1164                    system_latency_constraint());
1165
1166         seq_puts(seq, "states:\n");
1167
1168         for (i = 1; i <= pr->power.count; i++) {
1169                 seq_printf(seq, "   %cC%d:                  ",
1170                            (&pr->power.states[i] ==
1171                             pr->power.state ? '*' : ' '), i);
1172
1173                 if (!pr->power.states[i].valid) {
1174                         seq_puts(seq, "<not supported>\n");
1175                         continue;
1176                 }
1177
1178                 switch (pr->power.states[i].type) {
1179                 case ACPI_STATE_C1:
1180                         seq_printf(seq, "type[C1] ");
1181                         break;
1182                 case ACPI_STATE_C2:
1183                         seq_printf(seq, "type[C2] ");
1184                         break;
1185                 case ACPI_STATE_C3:
1186                         seq_printf(seq, "type[C3] ");
1187                         break;
1188                 default:
1189                         seq_printf(seq, "type[--] ");
1190                         break;
1191                 }
1192
1193                 if (pr->power.states[i].promotion.state)
1194                         seq_printf(seq, "promotion[C%zd] ",
1195                                    (pr->power.states[i].promotion.state -
1196                                     pr->power.states));
1197                 else
1198                         seq_puts(seq, "promotion[--] ");
1199
1200                 if (pr->power.states[i].demotion.state)
1201                         seq_printf(seq, "demotion[C%zd] ",
1202                                    (pr->power.states[i].demotion.state -
1203                                     pr->power.states));
1204                 else
1205                         seq_puts(seq, "demotion[--] ");
1206
1207                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1208                            pr->power.states[i].latency,
1209                            pr->power.states[i].usage,
1210                            (unsigned long long)pr->power.states[i].time);
1211         }
1212
1213       end:
1214         return 0;
1215 }
1216
1217 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1218 {
1219         return single_open(file, acpi_processor_power_seq_show,
1220                            PDE(inode)->data);
1221 }
1222
1223 static const struct file_operations acpi_processor_power_fops = {
1224         .open = acpi_processor_power_open_fs,
1225         .read = seq_read,
1226         .llseek = seq_lseek,
1227         .release = single_release,
1228 };
1229
1230 #ifdef CONFIG_SMP
1231 static void smp_callback(void *v)
1232 {
1233         /* we already woke the CPU up, nothing more to do */
1234 }
1235
1236 /*
1237  * This function gets called when a part of the kernel has a new latency
1238  * requirement.  This means we need to get all processors out of their C-state,
1239  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1240  * wakes them all right up.
1241  */
1242 static int acpi_processor_latency_notify(struct notifier_block *b,
1243                 unsigned long l, void *v)
1244 {
1245         smp_call_function(smp_callback, NULL, 0, 1);
1246         return NOTIFY_OK;
1247 }
1248
1249 static struct notifier_block acpi_processor_latency_notifier = {
1250         .notifier_call = acpi_processor_latency_notify,
1251 };
1252 #endif
1253
1254 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1255                               struct acpi_device *device)
1256 {
1257         acpi_status status = 0;
1258         static int first_run;
1259         struct proc_dir_entry *entry = NULL;
1260         unsigned int i;
1261
1262
1263         if (!first_run) {
1264                 dmi_check_system(processor_power_dmi_table);
1265                 if (max_cstate < ACPI_C_STATES_MAX)
1266                         printk(KERN_NOTICE
1267                                "ACPI: processor limited to max C-state %d\n",
1268                                max_cstate);
1269                 first_run++;
1270 #ifdef CONFIG_SMP
1271                 register_latency_notifier(&acpi_processor_latency_notifier);
1272 #endif
1273         }
1274
1275         if (!pr)
1276                 return -EINVAL;
1277
1278         if (acpi_gbl_FADT.cst_control && !nocst) {
1279                 status =
1280                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1281                 if (ACPI_FAILURE(status)) {
1282                         ACPI_EXCEPTION((AE_INFO, status,
1283                                         "Notifying BIOS of _CST ability failed"));
1284                 }
1285         }
1286
1287         acpi_processor_get_power_info(pr);
1288
1289         /*
1290          * Install the idle handler if processor power management is supported.
1291          * Note that we use previously set idle handler will be used on
1292          * platforms that only support C1.
1293          */
1294         if ((pr->flags.power) && (!boot_option_idle_override)) {
1295                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1296                 for (i = 1; i <= pr->power.count; i++)
1297                         if (pr->power.states[i].valid)
1298                                 printk(" C%d[C%d]", i,
1299                                        pr->power.states[i].type);
1300                 printk(")\n");
1301
1302                 if (pr->id == 0) {
1303                         pm_idle_save = pm_idle;
1304                         pm_idle = acpi_processor_idle;
1305                 }
1306         }
1307
1308         /* 'power' [R] */
1309         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1310                                   S_IRUGO, acpi_device_dir(device));
1311         if (!entry)
1312                 return -EIO;
1313         else {
1314                 entry->proc_fops = &acpi_processor_power_fops;
1315                 entry->data = acpi_driver_data(device);
1316                 entry->owner = THIS_MODULE;
1317         }
1318
1319         pr->flags.power_setup_done = 1;
1320
1321         return 0;
1322 }
1323
1324 int acpi_processor_power_exit(struct acpi_processor *pr,
1325                               struct acpi_device *device)
1326 {
1327
1328         pr->flags.power_setup_done = 0;
1329
1330         if (acpi_device_dir(device))
1331                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1332                                   acpi_device_dir(device));
1333
1334         /* Unregister the idle handler when processor #0 is removed. */
1335         if (pr->id == 0) {
1336                 pm_idle = pm_idle_save;
1337
1338                 /*
1339                  * We are about to unload the current idle thread pm callback
1340                  * (pm_idle), Wait for all processors to update cached/local
1341                  * copies of pm_idle before proceeding.
1342                  */
1343                 cpu_idle_wait();
1344 #ifdef CONFIG_SMP
1345                 unregister_latency_notifier(&acpi_processor_latency_notifier);
1346 #endif
1347         }
1348
1349         return 0;
1350 }