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