Pull battery into release branch
[linux-3.10.git] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/cpufreq.h>
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/moduleparam.h>
40 #include <linux/sched.h>        /* need_resched() */
41 #include <linux/latency.h>
42 #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(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 #ifdef CONFIG_GENERIC_CLOCKEVENTS
280         unsigned long reason;
281
282         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
283                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
284
285         clockevents_notify(reason, &pr->id);
286 #else
287         cpumask_t mask = cpumask_of_cpu(pr->id);
288
289         if (pr->power.timer_broadcast_on_state < INT_MAX)
290                 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
291         else
292                 on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
293 #endif
294 }
295
296 /* Power(C) State timer broadcast control */
297 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
298                                        struct acpi_processor_cx *cx,
299                                        int broadcast)
300 {
301 #ifdef CONFIG_GENERIC_CLOCKEVENTS
302
303         int state = cx - pr->power.states;
304
305         if (state >= pr->power.timer_broadcast_on_state) {
306                 unsigned long reason;
307
308                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
309                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
310                 clockevents_notify(reason, &pr->id);
311         }
312 #endif
313 }
314
315 #else
316
317 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
318                                    struct acpi_processor_cx *cstate) { }
319 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
320 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
321                                        struct acpi_processor_cx *cx,
322                                        int broadcast)
323 {
324 }
325
326 #endif
327
328 static void acpi_processor_idle(void)
329 {
330         struct acpi_processor *pr = NULL;
331         struct acpi_processor_cx *cx = NULL;
332         struct acpi_processor_cx *next_state = NULL;
333         int sleep_ticks = 0;
334         u32 t1, t2 = 0;
335
336         /*
337          * Interrupts must be disabled during bus mastering calculations and
338          * for C2/C3 transitions.
339          */
340         local_irq_disable();
341
342         pr = processors[smp_processor_id()];
343         if (!pr) {
344                 local_irq_enable();
345                 return;
346         }
347
348         /*
349          * Check whether we truly need to go idle, or should
350          * reschedule:
351          */
352         if (unlikely(need_resched())) {
353                 local_irq_enable();
354                 return;
355         }
356
357         cx = pr->power.state;
358         if (!cx) {
359                 if (pm_idle_save)
360                         pm_idle_save();
361                 else
362                         acpi_safe_halt();
363                 return;
364         }
365
366         /*
367          * Check BM Activity
368          * -----------------
369          * Check for bus mastering activity (if required), record, and check
370          * for demotion.
371          */
372         if (pr->flags.bm_check) {
373                 u32 bm_status = 0;
374                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
375
376                 if (diff > 31)
377                         diff = 31;
378
379                 pr->power.bm_activity <<= diff;
380
381                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
382                 if (bm_status) {
383                         pr->power.bm_activity |= 0x1;
384                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
385                 }
386                 /*
387                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
388                  * the true state of bus mastering activity; forcing us to
389                  * manually check the BMIDEA bit of each IDE channel.
390                  */
391                 else if (errata.piix4.bmisx) {
392                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
393                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
394                                 pr->power.bm_activity |= 0x1;
395                 }
396
397                 pr->power.bm_check_timestamp = jiffies;
398
399                 /*
400                  * If bus mastering is or was active this jiffy, demote
401                  * to avoid a faulty transition.  Note that the processor
402                  * won't enter a low-power state during this call (to this
403                  * function) but should upon the next.
404                  *
405                  * TBD: A better policy might be to fallback to the demotion
406                  *      state (use it for this quantum only) istead of
407                  *      demoting -- and rely on duration as our sole demotion
408                  *      qualification.  This may, however, introduce DMA
409                  *      issues (e.g. floppy DMA transfer overrun/underrun).
410                  */
411                 if ((pr->power.bm_activity & 0x1) &&
412                     cx->demotion.threshold.bm) {
413                         local_irq_enable();
414                         next_state = cx->demotion.state;
415                         goto end;
416                 }
417         }
418
419 #ifdef CONFIG_HOTPLUG_CPU
420         /*
421          * Check for P_LVL2_UP flag before entering C2 and above on
422          * an SMP system. We do it here instead of doing it at _CST/P_LVL
423          * detection phase, to work cleanly with logical CPU hotplug.
424          */
425         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
426             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
427                 cx = &pr->power.states[ACPI_STATE_C1];
428 #endif
429
430         /*
431          * Sleep:
432          * ------
433          * Invoke the current Cx state to put the processor to sleep.
434          */
435         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
436                 current_thread_info()->status &= ~TS_POLLING;
437                 /*
438                  * TS_POLLING-cleared state must be visible before we
439                  * test NEED_RESCHED:
440                  */
441                 smp_mb();
442                 if (need_resched()) {
443                         current_thread_info()->status |= TS_POLLING;
444                         local_irq_enable();
445                         return;
446                 }
447         }
448
449         switch (cx->type) {
450
451         case ACPI_STATE_C1:
452                 /*
453                  * Invoke C1.
454                  * Use the appropriate idle routine, the one that would
455                  * be used without acpi C-states.
456                  */
457                 if (pm_idle_save)
458                         pm_idle_save();
459                 else
460                         acpi_safe_halt();
461
462                 /*
463                  * TBD: Can't get time duration while in C1, as resumes
464                  *      go to an ISR rather than here.  Need to instrument
465                  *      base interrupt handler.
466                  *
467                  * Note: the TSC better not stop in C1, sched_clock() will
468                  *       skew otherwise.
469                  */
470                 sleep_ticks = 0xFFFFFFFF;
471                 break;
472
473         case ACPI_STATE_C2:
474                 /* Get start time (ticks) */
475                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
476                 /* Tell the scheduler that we are going deep-idle: */
477                 sched_clock_idle_sleep_event();
478                 /* Invoke C2 */
479                 acpi_state_timer_broadcast(pr, cx, 1);
480                 acpi_cstate_enter(cx);
481                 /* Get end time (ticks) */
482                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
483
484 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
485                 /* TSC halts in C2, so notify users */
486                 mark_tsc_unstable("possible TSC halt in C2");
487 #endif
488                 /* Compute time (ticks) that we were actually asleep */
489                 sleep_ticks = ticks_elapsed(t1, t2);
490
491                 /* Tell the scheduler how much we idled: */
492                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
493
494                 /* Re-enable interrupts */
495                 local_irq_enable();
496                 /* Do not account our idle-switching overhead: */
497                 sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
498
499                 current_thread_info()->status |= TS_POLLING;
500                 acpi_state_timer_broadcast(pr, cx, 0);
501                 break;
502
503         case ACPI_STATE_C3:
504                 /*
505                  * disable bus master
506                  * bm_check implies we need ARB_DIS
507                  * !bm_check implies we need cache flush
508                  * bm_control implies whether we can do ARB_DIS
509                  *
510                  * That leaves a case where bm_check is set and bm_control is
511                  * not set. In that case we cannot do much, we enter C3
512                  * without doing anything.
513                  */
514                 if (pr->flags.bm_check && pr->flags.bm_control) {
515                         if (atomic_inc_return(&c3_cpu_count) ==
516                             num_online_cpus()) {
517                                 /*
518                                  * All CPUs are trying to go to C3
519                                  * Disable bus master arbitration
520                                  */
521                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
522                         }
523                 } else if (!pr->flags.bm_check) {
524                         /* SMP with no shared cache... Invalidate cache  */
525                         ACPI_FLUSH_CPU_CACHE();
526                 }
527
528                 /* Get start time (ticks) */
529                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
530                 /* Invoke C3 */
531                 acpi_state_timer_broadcast(pr, cx, 1);
532                 /* Tell the scheduler that we are going deep-idle: */
533                 sched_clock_idle_sleep_event();
534                 acpi_cstate_enter(cx);
535                 /* Get end time (ticks) */
536                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
537                 if (pr->flags.bm_check && pr->flags.bm_control) {
538                         /* Enable bus master arbitration */
539                         atomic_dec(&c3_cpu_count);
540                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
541                 }
542
543 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
544                 /* TSC halts in C3, so notify users */
545                 mark_tsc_unstable("TSC halts in C3");
546 #endif
547                 /* Compute time (ticks) that we were actually asleep */
548                 sleep_ticks = ticks_elapsed(t1, t2);
549                 /* Tell the scheduler how much we idled: */
550                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
551
552                 /* Re-enable interrupts */
553                 local_irq_enable();
554                 /* Do not account our idle-switching overhead: */
555                 sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
556
557                 current_thread_info()->status |= TS_POLLING;
558                 acpi_state_timer_broadcast(pr, cx, 0);
559                 break;
560
561         default:
562                 local_irq_enable();
563                 return;
564         }
565         cx->usage++;
566         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
567                 cx->time += sleep_ticks;
568
569         next_state = pr->power.state;
570
571 #ifdef CONFIG_HOTPLUG_CPU
572         /* Don't do promotion/demotion */
573         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
574             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
575                 next_state = cx;
576                 goto end;
577         }
578 #endif
579
580         /*
581          * Promotion?
582          * ----------
583          * Track the number of longs (time asleep is greater than threshold)
584          * and promote when the count threshold is reached.  Note that bus
585          * mastering activity may prevent promotions.
586          * Do not promote above max_cstate.
587          */
588         if (cx->promotion.state &&
589             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
590                 if (sleep_ticks > cx->promotion.threshold.ticks &&
591                   cx->promotion.state->latency <= system_latency_constraint()) {
592                         cx->promotion.count++;
593                         cx->demotion.count = 0;
594                         if (cx->promotion.count >=
595                             cx->promotion.threshold.count) {
596                                 if (pr->flags.bm_check) {
597                                         if (!
598                                             (pr->power.bm_activity & cx->
599                                              promotion.threshold.bm)) {
600                                                 next_state =
601                                                     cx->promotion.state;
602                                                 goto end;
603                                         }
604                                 } else {
605                                         next_state = cx->promotion.state;
606                                         goto end;
607                                 }
608                         }
609                 }
610         }
611
612         /*
613          * Demotion?
614          * ---------
615          * Track the number of shorts (time asleep is less than time threshold)
616          * and demote when the usage threshold is reached.
617          */
618         if (cx->demotion.state) {
619                 if (sleep_ticks < cx->demotion.threshold.ticks) {
620                         cx->demotion.count++;
621                         cx->promotion.count = 0;
622                         if (cx->demotion.count >= cx->demotion.threshold.count) {
623                                 next_state = cx->demotion.state;
624                                 goto end;
625                         }
626                 }
627         }
628
629       end:
630         /*
631          * Demote if current state exceeds max_cstate
632          * or if the latency of the current state is unacceptable
633          */
634         if ((pr->power.state - pr->power.states) > max_cstate ||
635                 pr->power.state->latency > system_latency_constraint()) {
636                 if (cx->demotion.state)
637                         next_state = cx->demotion.state;
638         }
639
640         /*
641          * New Cx State?
642          * -------------
643          * If we're going to start using a new Cx state we must clean up
644          * from the previous and prepare to use the new.
645          */
646         if (next_state != pr->power.state)
647                 acpi_processor_power_activate(pr, next_state);
648 }
649
650 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
651 {
652         unsigned int i;
653         unsigned int state_is_set = 0;
654         struct acpi_processor_cx *lower = NULL;
655         struct acpi_processor_cx *higher = NULL;
656         struct acpi_processor_cx *cx;
657
658
659         if (!pr)
660                 return -EINVAL;
661
662         /*
663          * This function sets the default Cx state policy (OS idle handler).
664          * Our scheme is to promote quickly to C2 but more conservatively
665          * to C3.  We're favoring C2  for its characteristics of low latency
666          * (quick response), good power savings, and ability to allow bus
667          * mastering activity.  Note that the Cx state policy is completely
668          * customizable and can be altered dynamically.
669          */
670
671         /* startup state */
672         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
673                 cx = &pr->power.states[i];
674                 if (!cx->valid)
675                         continue;
676
677                 if (!state_is_set)
678                         pr->power.state = cx;
679                 state_is_set++;
680                 break;
681         }
682
683         if (!state_is_set)
684                 return -ENODEV;
685
686         /* demotion */
687         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
688                 cx = &pr->power.states[i];
689                 if (!cx->valid)
690                         continue;
691
692                 if (lower) {
693                         cx->demotion.state = lower;
694                         cx->demotion.threshold.ticks = cx->latency_ticks;
695                         cx->demotion.threshold.count = 1;
696                         if (cx->type == ACPI_STATE_C3)
697                                 cx->demotion.threshold.bm = bm_history;
698                 }
699
700                 lower = cx;
701         }
702
703         /* promotion */
704         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
705                 cx = &pr->power.states[i];
706                 if (!cx->valid)
707                         continue;
708
709                 if (higher) {
710                         cx->promotion.state = higher;
711                         cx->promotion.threshold.ticks = cx->latency_ticks;
712                         if (cx->type >= ACPI_STATE_C2)
713                                 cx->promotion.threshold.count = 4;
714                         else
715                                 cx->promotion.threshold.count = 10;
716                         if (higher->type == ACPI_STATE_C3)
717                                 cx->promotion.threshold.bm = bm_history;
718                 }
719
720                 higher = cx;
721         }
722
723         return 0;
724 }
725
726 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
727 {
728
729         if (!pr)
730                 return -EINVAL;
731
732         if (!pr->pblk)
733                 return -ENODEV;
734
735         /* if info is obtained from pblk/fadt, type equals state */
736         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
737         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
738
739 #ifndef CONFIG_HOTPLUG_CPU
740         /*
741          * Check for P_LVL2_UP flag before entering C2 and above on
742          * an SMP system. 
743          */
744         if ((num_online_cpus() > 1) &&
745             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
746                 return -ENODEV;
747 #endif
748
749         /* determine C2 and C3 address from pblk */
750         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
751         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
752
753         /* determine latencies from FADT */
754         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
755         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
756
757         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
758                           "lvl2[0x%08x] lvl3[0x%08x]\n",
759                           pr->power.states[ACPI_STATE_C2].address,
760                           pr->power.states[ACPI_STATE_C3].address));
761
762         return 0;
763 }
764
765 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
766 {
767         if (!pr->power.states[ACPI_STATE_C1].valid) {
768                 /* set the first C-State to C1 */
769                 /* all processors need to support C1 */
770                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
771                 pr->power.states[ACPI_STATE_C1].valid = 1;
772         }
773         /* the C0 state only exists as a filler in our array */
774         pr->power.states[ACPI_STATE_C0].valid = 1;
775         return 0;
776 }
777
778 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
779 {
780         acpi_status status = 0;
781         acpi_integer count;
782         int current_count;
783         int i;
784         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
785         union acpi_object *cst;
786
787
788         if (nocst)
789                 return -ENODEV;
790
791         current_count = 0;
792
793         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
794         if (ACPI_FAILURE(status)) {
795                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
796                 return -ENODEV;
797         }
798
799         cst = buffer.pointer;
800
801         /* There must be at least 2 elements */
802         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
803                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
804                 status = -EFAULT;
805                 goto end;
806         }
807
808         count = cst->package.elements[0].integer.value;
809
810         /* Validate number of power states. */
811         if (count < 1 || count != cst->package.count - 1) {
812                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
813                 status = -EFAULT;
814                 goto end;
815         }
816
817         /* Tell driver that at least _CST is supported. */
818         pr->flags.has_cst = 1;
819
820         for (i = 1; i <= count; i++) {
821                 union acpi_object *element;
822                 union acpi_object *obj;
823                 struct acpi_power_register *reg;
824                 struct acpi_processor_cx cx;
825
826                 memset(&cx, 0, sizeof(cx));
827
828                 element = &(cst->package.elements[i]);
829                 if (element->type != ACPI_TYPE_PACKAGE)
830                         continue;
831
832                 if (element->package.count != 4)
833                         continue;
834
835                 obj = &(element->package.elements[0]);
836
837                 if (obj->type != ACPI_TYPE_BUFFER)
838                         continue;
839
840                 reg = (struct acpi_power_register *)obj->buffer.pointer;
841
842                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
843                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
844                         continue;
845
846                 /* There should be an easy way to extract an integer... */
847                 obj = &(element->package.elements[1]);
848                 if (obj->type != ACPI_TYPE_INTEGER)
849                         continue;
850
851                 cx.type = obj->integer.value;
852                 /*
853                  * Some buggy BIOSes won't list C1 in _CST -
854                  * Let acpi_processor_get_power_info_default() handle them later
855                  */
856                 if (i == 1 && cx.type != ACPI_STATE_C1)
857                         current_count++;
858
859                 cx.address = reg->address;
860                 cx.index = current_count + 1;
861
862                 cx.space_id = ACPI_CSTATE_SYSTEMIO;
863                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
864                         if (acpi_processor_ffh_cstate_probe
865                                         (pr->id, &cx, reg) == 0) {
866                                 cx.space_id = ACPI_CSTATE_FFH;
867                         } else if (cx.type != ACPI_STATE_C1) {
868                                 /*
869                                  * C1 is a special case where FIXED_HARDWARE
870                                  * can be handled in non-MWAIT way as well.
871                                  * In that case, save this _CST entry info.
872                                  * That is, we retain space_id of SYSTEM_IO for
873                                  * halt based C1.
874                                  * Otherwise, ignore this info and continue.
875                                  */
876                                 continue;
877                         }
878                 }
879
880                 obj = &(element->package.elements[2]);
881                 if (obj->type != ACPI_TYPE_INTEGER)
882                         continue;
883
884                 cx.latency = obj->integer.value;
885
886                 obj = &(element->package.elements[3]);
887                 if (obj->type != ACPI_TYPE_INTEGER)
888                         continue;
889
890                 cx.power = obj->integer.value;
891
892                 current_count++;
893                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
894
895                 /*
896                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
897                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
898                  */
899                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
900                         printk(KERN_WARNING
901                                "Limiting number of power states to max (%d)\n",
902                                ACPI_PROCESSOR_MAX_POWER);
903                         printk(KERN_WARNING
904                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
905                         break;
906                 }
907         }
908
909         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
910                           current_count));
911
912         /* Validate number of power states discovered */
913         if (current_count < 2)
914                 status = -EFAULT;
915
916       end:
917         kfree(buffer.pointer);
918
919         return status;
920 }
921
922 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
923 {
924
925         if (!cx->address)
926                 return;
927
928         /*
929          * C2 latency must be less than or equal to 100
930          * microseconds.
931          */
932         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
933                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
934                                   "latency too large [%d]\n", cx->latency));
935                 return;
936         }
937
938         /*
939          * Otherwise we've met all of our C2 requirements.
940          * Normalize the C2 latency to expidite policy
941          */
942         cx->valid = 1;
943         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
944
945         return;
946 }
947
948 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
949                                            struct acpi_processor_cx *cx)
950 {
951         static int bm_check_flag;
952
953
954         if (!cx->address)
955                 return;
956
957         /*
958          * C3 latency must be less than or equal to 1000
959          * microseconds.
960          */
961         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
962                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
963                                   "latency too large [%d]\n", cx->latency));
964                 return;
965         }
966
967         /*
968          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
969          * DMA transfers are used by any ISA device to avoid livelock.
970          * Note that we could disable Type-F DMA (as recommended by
971          * the erratum), but this is known to disrupt certain ISA
972          * devices thus we take the conservative approach.
973          */
974         else if (errata.piix4.fdma) {
975                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
976                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
977                 return;
978         }
979
980         /* All the logic here assumes flags.bm_check is same across all CPUs */
981         if (!bm_check_flag) {
982                 /* Determine whether bm_check is needed based on CPU  */
983                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
984                 bm_check_flag = pr->flags.bm_check;
985         } else {
986                 pr->flags.bm_check = bm_check_flag;
987         }
988
989         if (pr->flags.bm_check) {
990                 if (!pr->flags.bm_control) {
991                         if (pr->flags.has_cst != 1) {
992                                 /* bus mastering control is necessary */
993                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
994                                         "C3 support requires BM control\n"));
995                                 return;
996                         } else {
997                                 /* Here we enter C3 without bus mastering */
998                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
999                                         "C3 support without BM control\n"));
1000                         }
1001                 }
1002         } else {
1003                 /*
1004                  * WBINVD should be set in fadt, for C3 state to be
1005                  * supported on when bm_check is not required.
1006                  */
1007                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
1008                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1009                                           "Cache invalidation should work properly"
1010                                           " for C3 to be enabled on SMP systems\n"));
1011                         return;
1012                 }
1013                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
1014         }
1015
1016         /*
1017          * Otherwise we've met all of our C3 requirements.
1018          * Normalize the C3 latency to expidite policy.  Enable
1019          * checking of bus mastering status (bm_check) so we can
1020          * use this in our C3 policy
1021          */
1022         cx->valid = 1;
1023         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1024
1025         return;
1026 }
1027
1028 static int acpi_processor_power_verify(struct acpi_processor *pr)
1029 {
1030         unsigned int i;
1031         unsigned int working = 0;
1032
1033         pr->power.timer_broadcast_on_state = INT_MAX;
1034
1035         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1036                 struct acpi_processor_cx *cx = &pr->power.states[i];
1037
1038                 switch (cx->type) {
1039                 case ACPI_STATE_C1:
1040                         cx->valid = 1;
1041                         break;
1042
1043                 case ACPI_STATE_C2:
1044                         acpi_processor_power_verify_c2(cx);
1045                         if (cx->valid)
1046                                 acpi_timer_check_state(i, pr, cx);
1047                         break;
1048
1049                 case ACPI_STATE_C3:
1050                         acpi_processor_power_verify_c3(pr, cx);
1051                         if (cx->valid)
1052                                 acpi_timer_check_state(i, pr, cx);
1053                         break;
1054                 }
1055
1056                 if (cx->valid)
1057                         working++;
1058         }
1059
1060         acpi_propagate_timer_broadcast(pr);
1061
1062         return (working);
1063 }
1064
1065 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1066 {
1067         unsigned int i;
1068         int result;
1069
1070
1071         /* NOTE: the idle thread may not be running while calling
1072          * this function */
1073
1074         /* Zero initialize all the C-states info. */
1075         memset(pr->power.states, 0, sizeof(pr->power.states));
1076
1077         result = acpi_processor_get_power_info_cst(pr);
1078         if (result == -ENODEV)
1079                 result = acpi_processor_get_power_info_fadt(pr);
1080
1081         if (result)
1082                 return result;
1083
1084         acpi_processor_get_power_info_default(pr);
1085
1086         pr->power.count = acpi_processor_power_verify(pr);
1087
1088         /*
1089          * Set Default Policy
1090          * ------------------
1091          * Now that we know which states are supported, set the default
1092          * policy.  Note that this policy can be changed dynamically
1093          * (e.g. encourage deeper sleeps to conserve battery life when
1094          * not on AC).
1095          */
1096         result = acpi_processor_set_power_policy(pr);
1097         if (result)
1098                 return result;
1099
1100         /*
1101          * if one state of type C2 or C3 is available, mark this
1102          * CPU as being "idle manageable"
1103          */
1104         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1105                 if (pr->power.states[i].valid) {
1106                         pr->power.count = i;
1107                         if (pr->power.states[i].type >= ACPI_STATE_C2)
1108                                 pr->flags.power = 1;
1109                 }
1110         }
1111
1112         return 0;
1113 }
1114
1115 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1116 {
1117         int result = 0;
1118
1119
1120         if (!pr)
1121                 return -EINVAL;
1122
1123         if (nocst) {
1124                 return -ENODEV;
1125         }
1126
1127         if (!pr->flags.power_setup_done)
1128                 return -ENODEV;
1129
1130         /* Fall back to the default idle loop */
1131         pm_idle = pm_idle_save;
1132         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
1133
1134         pr->flags.power = 0;
1135         result = acpi_processor_get_power_info(pr);
1136         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1137                 pm_idle = acpi_processor_idle;
1138
1139         return result;
1140 }
1141
1142 /* proc interface */
1143
1144 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1145 {
1146         struct acpi_processor *pr = seq->private;
1147         unsigned int i;
1148
1149
1150         if (!pr)
1151                 goto end;
1152
1153         seq_printf(seq, "active state:            C%zd\n"
1154                    "max_cstate:              C%d\n"
1155                    "bus master activity:     %08x\n"
1156                    "maximum allowed latency: %d usec\n",
1157                    pr->power.state ? pr->power.state - pr->power.states : 0,
1158                    max_cstate, (unsigned)pr->power.bm_activity,
1159                    system_latency_constraint());
1160
1161         seq_puts(seq, "states:\n");
1162
1163         for (i = 1; i <= pr->power.count; i++) {
1164                 seq_printf(seq, "   %cC%d:                  ",
1165                            (&pr->power.states[i] ==
1166                             pr->power.state ? '*' : ' '), i);
1167
1168                 if (!pr->power.states[i].valid) {
1169                         seq_puts(seq, "<not supported>\n");
1170                         continue;
1171                 }
1172
1173                 switch (pr->power.states[i].type) {
1174                 case ACPI_STATE_C1:
1175                         seq_printf(seq, "type[C1] ");
1176                         break;
1177                 case ACPI_STATE_C2:
1178                         seq_printf(seq, "type[C2] ");
1179                         break;
1180                 case ACPI_STATE_C3:
1181                         seq_printf(seq, "type[C3] ");
1182                         break;
1183                 default:
1184                         seq_printf(seq, "type[--] ");
1185                         break;
1186                 }
1187
1188                 if (pr->power.states[i].promotion.state)
1189                         seq_printf(seq, "promotion[C%zd] ",
1190                                    (pr->power.states[i].promotion.state -
1191                                     pr->power.states));
1192                 else
1193                         seq_puts(seq, "promotion[--] ");
1194
1195                 if (pr->power.states[i].demotion.state)
1196                         seq_printf(seq, "demotion[C%zd] ",
1197                                    (pr->power.states[i].demotion.state -
1198                                     pr->power.states));
1199                 else
1200                         seq_puts(seq, "demotion[--] ");
1201
1202                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1203                            pr->power.states[i].latency,
1204                            pr->power.states[i].usage,
1205                            (unsigned long long)pr->power.states[i].time);
1206         }
1207
1208       end:
1209         return 0;
1210 }
1211
1212 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1213 {
1214         return single_open(file, acpi_processor_power_seq_show,
1215                            PDE(inode)->data);
1216 }
1217
1218 static const struct file_operations acpi_processor_power_fops = {
1219         .open = acpi_processor_power_open_fs,
1220         .read = seq_read,
1221         .llseek = seq_lseek,
1222         .release = single_release,
1223 };
1224
1225 #ifdef CONFIG_SMP
1226 static void smp_callback(void *v)
1227 {
1228         /* we already woke the CPU up, nothing more to do */
1229 }
1230
1231 /*
1232  * This function gets called when a part of the kernel has a new latency
1233  * requirement.  This means we need to get all processors out of their C-state,
1234  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1235  * wakes them all right up.
1236  */
1237 static int acpi_processor_latency_notify(struct notifier_block *b,
1238                 unsigned long l, void *v)
1239 {
1240         smp_call_function(smp_callback, NULL, 0, 1);
1241         return NOTIFY_OK;
1242 }
1243
1244 static struct notifier_block acpi_processor_latency_notifier = {
1245         .notifier_call = acpi_processor_latency_notify,
1246 };
1247 #endif
1248
1249 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1250                               struct acpi_device *device)
1251 {
1252         acpi_status status = 0;
1253         static int first_run;
1254         struct proc_dir_entry *entry = NULL;
1255         unsigned int i;
1256
1257
1258         if (!first_run) {
1259                 dmi_check_system(processor_power_dmi_table);
1260                 if (max_cstate < ACPI_C_STATES_MAX)
1261                         printk(KERN_NOTICE
1262                                "ACPI: processor limited to max C-state %d\n",
1263                                max_cstate);
1264                 first_run++;
1265 #ifdef CONFIG_SMP
1266                 register_latency_notifier(&acpi_processor_latency_notifier);
1267 #endif
1268         }
1269
1270         if (!pr)
1271                 return -EINVAL;
1272
1273         if (acpi_gbl_FADT.cst_control && !nocst) {
1274                 status =
1275                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1276                 if (ACPI_FAILURE(status)) {
1277                         ACPI_EXCEPTION((AE_INFO, status,
1278                                         "Notifying BIOS of _CST ability failed"));
1279                 }
1280         }
1281
1282         acpi_processor_get_power_info(pr);
1283
1284         /*
1285          * Install the idle handler if processor power management is supported.
1286          * Note that we use previously set idle handler will be used on
1287          * platforms that only support C1.
1288          */
1289         if ((pr->flags.power) && (!boot_option_idle_override)) {
1290                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1291                 for (i = 1; i <= pr->power.count; i++)
1292                         if (pr->power.states[i].valid)
1293                                 printk(" C%d[C%d]", i,
1294                                        pr->power.states[i].type);
1295                 printk(")\n");
1296
1297                 if (pr->id == 0) {
1298                         pm_idle_save = pm_idle;
1299                         pm_idle = acpi_processor_idle;
1300                 }
1301         }
1302
1303         /* 'power' [R] */
1304         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1305                                   S_IRUGO, acpi_device_dir(device));
1306         if (!entry)
1307                 return -EIO;
1308         else {
1309                 entry->proc_fops = &acpi_processor_power_fops;
1310                 entry->data = acpi_driver_data(device);
1311                 entry->owner = THIS_MODULE;
1312         }
1313
1314         pr->flags.power_setup_done = 1;
1315
1316         return 0;
1317 }
1318
1319 int acpi_processor_power_exit(struct acpi_processor *pr,
1320                               struct acpi_device *device)
1321 {
1322
1323         pr->flags.power_setup_done = 0;
1324
1325         if (acpi_device_dir(device))
1326                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1327                                   acpi_device_dir(device));
1328
1329         /* Unregister the idle handler when processor #0 is removed. */
1330         if (pr->id == 0) {
1331                 pm_idle = pm_idle_save;
1332
1333                 /*
1334                  * We are about to unload the current idle thread pm callback
1335                  * (pm_idle), Wait for all processors to update cached/local
1336                  * copies of pm_idle before proceeding.
1337                  */
1338                 cpu_idle_wait();
1339 #ifdef CONFIG_SMP
1340                 unregister_latency_notifier(&acpi_processor_latency_notifier);
1341 #endif
1342         }
1343
1344         return 0;
1345 }