ACPI: disable lower idle C-states across suspend/resume
[sfrench/cifs-2.6.git] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/cpufreq.h>
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/moduleparam.h>
40 #include <linux/sched.h>        /* need_resched() */
41 #include <linux/latency.h>
42 #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 /*
329  * Suspend / resume control
330  */
331 static int acpi_idle_suspend;
332
333 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
334 {
335         acpi_idle_suspend = 1;
336         return 0;
337 }
338
339 int acpi_processor_resume(struct acpi_device * device)
340 {
341         acpi_idle_suspend = 0;
342         return 0;
343 }
344
345 static void acpi_processor_idle(void)
346 {
347         struct acpi_processor *pr = NULL;
348         struct acpi_processor_cx *cx = NULL;
349         struct acpi_processor_cx *next_state = NULL;
350         int sleep_ticks = 0;
351         u32 t1, t2 = 0;
352
353         /*
354          * Interrupts must be disabled during bus mastering calculations and
355          * for C2/C3 transitions.
356          */
357         local_irq_disable();
358
359         pr = processors[smp_processor_id()];
360         if (!pr) {
361                 local_irq_enable();
362                 return;
363         }
364
365         /*
366          * Check whether we truly need to go idle, or should
367          * reschedule:
368          */
369         if (unlikely(need_resched())) {
370                 local_irq_enable();
371                 return;
372         }
373
374         cx = pr->power.state;
375         if (!cx || acpi_idle_suspend) {
376                 if (pm_idle_save)
377                         pm_idle_save();
378                 else
379                         acpi_safe_halt();
380                 return;
381         }
382
383         /*
384          * Check BM Activity
385          * -----------------
386          * Check for bus mastering activity (if required), record, and check
387          * for demotion.
388          */
389         if (pr->flags.bm_check) {
390                 u32 bm_status = 0;
391                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
392
393                 if (diff > 31)
394                         diff = 31;
395
396                 pr->power.bm_activity <<= diff;
397
398                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
399                 if (bm_status) {
400                         pr->power.bm_activity |= 0x1;
401                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
402                 }
403                 /*
404                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
405                  * the true state of bus mastering activity; forcing us to
406                  * manually check the BMIDEA bit of each IDE channel.
407                  */
408                 else if (errata.piix4.bmisx) {
409                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
410                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
411                                 pr->power.bm_activity |= 0x1;
412                 }
413
414                 pr->power.bm_check_timestamp = jiffies;
415
416                 /*
417                  * If bus mastering is or was active this jiffy, demote
418                  * to avoid a faulty transition.  Note that the processor
419                  * won't enter a low-power state during this call (to this
420                  * function) but should upon the next.
421                  *
422                  * TBD: A better policy might be to fallback to the demotion
423                  *      state (use it for this quantum only) istead of
424                  *      demoting -- and rely on duration as our sole demotion
425                  *      qualification.  This may, however, introduce DMA
426                  *      issues (e.g. floppy DMA transfer overrun/underrun).
427                  */
428                 if ((pr->power.bm_activity & 0x1) &&
429                     cx->demotion.threshold.bm) {
430                         local_irq_enable();
431                         next_state = cx->demotion.state;
432                         goto end;
433                 }
434         }
435
436 #ifdef CONFIG_HOTPLUG_CPU
437         /*
438          * Check for P_LVL2_UP flag before entering C2 and above on
439          * an SMP system. We do it here instead of doing it at _CST/P_LVL
440          * detection phase, to work cleanly with logical CPU hotplug.
441          */
442         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
443             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
444                 cx = &pr->power.states[ACPI_STATE_C1];
445 #endif
446
447         /*
448          * Sleep:
449          * ------
450          * Invoke the current Cx state to put the processor to sleep.
451          */
452         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
453                 current_thread_info()->status &= ~TS_POLLING;
454                 /*
455                  * TS_POLLING-cleared state must be visible before we
456                  * test NEED_RESCHED:
457                  */
458                 smp_mb();
459                 if (need_resched()) {
460                         current_thread_info()->status |= TS_POLLING;
461                         local_irq_enable();
462                         return;
463                 }
464         }
465
466         switch (cx->type) {
467
468         case ACPI_STATE_C1:
469                 /*
470                  * Invoke C1.
471                  * Use the appropriate idle routine, the one that would
472                  * be used without acpi C-states.
473                  */
474                 if (pm_idle_save)
475                         pm_idle_save();
476                 else
477                         acpi_safe_halt();
478
479                 /*
480                  * TBD: Can't get time duration while in C1, as resumes
481                  *      go to an ISR rather than here.  Need to instrument
482                  *      base interrupt handler.
483                  *
484                  * Note: the TSC better not stop in C1, sched_clock() will
485                  *       skew otherwise.
486                  */
487                 sleep_ticks = 0xFFFFFFFF;
488                 break;
489
490         case ACPI_STATE_C2:
491                 /* Get start time (ticks) */
492                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
493                 /* Tell the scheduler that we are going deep-idle: */
494                 sched_clock_idle_sleep_event();
495                 /* Invoke C2 */
496                 acpi_state_timer_broadcast(pr, cx, 1);
497                 acpi_cstate_enter(cx);
498                 /* Get end time (ticks) */
499                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
500
501 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
502                 /* TSC halts in C2, so notify users */
503                 mark_tsc_unstable("possible TSC halt in C2");
504 #endif
505                 /* Compute time (ticks) that we were actually asleep */
506                 sleep_ticks = ticks_elapsed(t1, t2);
507
508                 /* Tell the scheduler how much we idled: */
509                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
510
511                 /* Re-enable interrupts */
512                 local_irq_enable();
513                 /* Do not account our idle-switching overhead: */
514                 sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
515
516                 current_thread_info()->status |= TS_POLLING;
517                 acpi_state_timer_broadcast(pr, cx, 0);
518                 break;
519
520         case ACPI_STATE_C3:
521                 /*
522                  * disable bus master
523                  * bm_check implies we need ARB_DIS
524                  * !bm_check implies we need cache flush
525                  * bm_control implies whether we can do ARB_DIS
526                  *
527                  * That leaves a case where bm_check is set and bm_control is
528                  * not set. In that case we cannot do much, we enter C3
529                  * without doing anything.
530                  */
531                 if (pr->flags.bm_check && pr->flags.bm_control) {
532                         if (atomic_inc_return(&c3_cpu_count) ==
533                             num_online_cpus()) {
534                                 /*
535                                  * All CPUs are trying to go to C3
536                                  * Disable bus master arbitration
537                                  */
538                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
539                         }
540                 } else if (!pr->flags.bm_check) {
541                         /* SMP with no shared cache... Invalidate cache  */
542                         ACPI_FLUSH_CPU_CACHE();
543                 }
544
545                 /* Get start time (ticks) */
546                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
547                 /* Invoke C3 */
548                 acpi_state_timer_broadcast(pr, cx, 1);
549                 /* Tell the scheduler that we are going deep-idle: */
550                 sched_clock_idle_sleep_event();
551                 acpi_cstate_enter(cx);
552                 /* Get end time (ticks) */
553                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
554                 if (pr->flags.bm_check && pr->flags.bm_control) {
555                         /* Enable bus master arbitration */
556                         atomic_dec(&c3_cpu_count);
557                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
558                 }
559
560 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
561                 /* TSC halts in C3, so notify users */
562                 mark_tsc_unstable("TSC halts in C3");
563 #endif
564                 /* Compute time (ticks) that we were actually asleep */
565                 sleep_ticks = ticks_elapsed(t1, t2);
566                 /* Tell the scheduler how much we idled: */
567                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
568
569                 /* Re-enable interrupts */
570                 local_irq_enable();
571                 /* Do not account our idle-switching overhead: */
572                 sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
573
574                 current_thread_info()->status |= TS_POLLING;
575                 acpi_state_timer_broadcast(pr, cx, 0);
576                 break;
577
578         default:
579                 local_irq_enable();
580                 return;
581         }
582         cx->usage++;
583         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
584                 cx->time += sleep_ticks;
585
586         next_state = pr->power.state;
587
588 #ifdef CONFIG_HOTPLUG_CPU
589         /* Don't do promotion/demotion */
590         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
591             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
592                 next_state = cx;
593                 goto end;
594         }
595 #endif
596
597         /*
598          * Promotion?
599          * ----------
600          * Track the number of longs (time asleep is greater than threshold)
601          * and promote when the count threshold is reached.  Note that bus
602          * mastering activity may prevent promotions.
603          * Do not promote above max_cstate.
604          */
605         if (cx->promotion.state &&
606             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
607                 if (sleep_ticks > cx->promotion.threshold.ticks &&
608                   cx->promotion.state->latency <= system_latency_constraint()) {
609                         cx->promotion.count++;
610                         cx->demotion.count = 0;
611                         if (cx->promotion.count >=
612                             cx->promotion.threshold.count) {
613                                 if (pr->flags.bm_check) {
614                                         if (!
615                                             (pr->power.bm_activity & cx->
616                                              promotion.threshold.bm)) {
617                                                 next_state =
618                                                     cx->promotion.state;
619                                                 goto end;
620                                         }
621                                 } else {
622                                         next_state = cx->promotion.state;
623                                         goto end;
624                                 }
625                         }
626                 }
627         }
628
629         /*
630          * Demotion?
631          * ---------
632          * Track the number of shorts (time asleep is less than time threshold)
633          * and demote when the usage threshold is reached.
634          */
635         if (cx->demotion.state) {
636                 if (sleep_ticks < cx->demotion.threshold.ticks) {
637                         cx->demotion.count++;
638                         cx->promotion.count = 0;
639                         if (cx->demotion.count >= cx->demotion.threshold.count) {
640                                 next_state = cx->demotion.state;
641                                 goto end;
642                         }
643                 }
644         }
645
646       end:
647         /*
648          * Demote if current state exceeds max_cstate
649          * or if the latency of the current state is unacceptable
650          */
651         if ((pr->power.state - pr->power.states) > max_cstate ||
652                 pr->power.state->latency > system_latency_constraint()) {
653                 if (cx->demotion.state)
654                         next_state = cx->demotion.state;
655         }
656
657         /*
658          * New Cx State?
659          * -------------
660          * If we're going to start using a new Cx state we must clean up
661          * from the previous and prepare to use the new.
662          */
663         if (next_state != pr->power.state)
664                 acpi_processor_power_activate(pr, next_state);
665 }
666
667 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
668 {
669         unsigned int i;
670         unsigned int state_is_set = 0;
671         struct acpi_processor_cx *lower = NULL;
672         struct acpi_processor_cx *higher = NULL;
673         struct acpi_processor_cx *cx;
674
675
676         if (!pr)
677                 return -EINVAL;
678
679         /*
680          * This function sets the default Cx state policy (OS idle handler).
681          * Our scheme is to promote quickly to C2 but more conservatively
682          * to C3.  We're favoring C2  for its characteristics of low latency
683          * (quick response), good power savings, and ability to allow bus
684          * mastering activity.  Note that the Cx state policy is completely
685          * customizable and can be altered dynamically.
686          */
687
688         /* startup state */
689         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
690                 cx = &pr->power.states[i];
691                 if (!cx->valid)
692                         continue;
693
694                 if (!state_is_set)
695                         pr->power.state = cx;
696                 state_is_set++;
697                 break;
698         }
699
700         if (!state_is_set)
701                 return -ENODEV;
702
703         /* demotion */
704         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
705                 cx = &pr->power.states[i];
706                 if (!cx->valid)
707                         continue;
708
709                 if (lower) {
710                         cx->demotion.state = lower;
711                         cx->demotion.threshold.ticks = cx->latency_ticks;
712                         cx->demotion.threshold.count = 1;
713                         if (cx->type == ACPI_STATE_C3)
714                                 cx->demotion.threshold.bm = bm_history;
715                 }
716
717                 lower = cx;
718         }
719
720         /* promotion */
721         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
722                 cx = &pr->power.states[i];
723                 if (!cx->valid)
724                         continue;
725
726                 if (higher) {
727                         cx->promotion.state = higher;
728                         cx->promotion.threshold.ticks = cx->latency_ticks;
729                         if (cx->type >= ACPI_STATE_C2)
730                                 cx->promotion.threshold.count = 4;
731                         else
732                                 cx->promotion.threshold.count = 10;
733                         if (higher->type == ACPI_STATE_C3)
734                                 cx->promotion.threshold.bm = bm_history;
735                 }
736
737                 higher = cx;
738         }
739
740         return 0;
741 }
742
743 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
744 {
745
746         if (!pr)
747                 return -EINVAL;
748
749         if (!pr->pblk)
750                 return -ENODEV;
751
752         /* if info is obtained from pblk/fadt, type equals state */
753         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
754         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
755
756 #ifndef CONFIG_HOTPLUG_CPU
757         /*
758          * Check for P_LVL2_UP flag before entering C2 and above on
759          * an SMP system. 
760          */
761         if ((num_online_cpus() > 1) &&
762             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
763                 return -ENODEV;
764 #endif
765
766         /* determine C2 and C3 address from pblk */
767         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
768         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
769
770         /* determine latencies from FADT */
771         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
772         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
773
774         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
775                           "lvl2[0x%08x] lvl3[0x%08x]\n",
776                           pr->power.states[ACPI_STATE_C2].address,
777                           pr->power.states[ACPI_STATE_C3].address));
778
779         return 0;
780 }
781
782 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
783 {
784         if (!pr->power.states[ACPI_STATE_C1].valid) {
785                 /* set the first C-State to C1 */
786                 /* all processors need to support C1 */
787                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
788                 pr->power.states[ACPI_STATE_C1].valid = 1;
789         }
790         /* the C0 state only exists as a filler in our array */
791         pr->power.states[ACPI_STATE_C0].valid = 1;
792         return 0;
793 }
794
795 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
796 {
797         acpi_status status = 0;
798         acpi_integer count;
799         int current_count;
800         int i;
801         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
802         union acpi_object *cst;
803
804
805         if (nocst)
806                 return -ENODEV;
807
808         current_count = 0;
809
810         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
811         if (ACPI_FAILURE(status)) {
812                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
813                 return -ENODEV;
814         }
815
816         cst = buffer.pointer;
817
818         /* There must be at least 2 elements */
819         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
820                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
821                 status = -EFAULT;
822                 goto end;
823         }
824
825         count = cst->package.elements[0].integer.value;
826
827         /* Validate number of power states. */
828         if (count < 1 || count != cst->package.count - 1) {
829                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
830                 status = -EFAULT;
831                 goto end;
832         }
833
834         /* Tell driver that at least _CST is supported. */
835         pr->flags.has_cst = 1;
836
837         for (i = 1; i <= count; i++) {
838                 union acpi_object *element;
839                 union acpi_object *obj;
840                 struct acpi_power_register *reg;
841                 struct acpi_processor_cx cx;
842
843                 memset(&cx, 0, sizeof(cx));
844
845                 element = &(cst->package.elements[i]);
846                 if (element->type != ACPI_TYPE_PACKAGE)
847                         continue;
848
849                 if (element->package.count != 4)
850                         continue;
851
852                 obj = &(element->package.elements[0]);
853
854                 if (obj->type != ACPI_TYPE_BUFFER)
855                         continue;
856
857                 reg = (struct acpi_power_register *)obj->buffer.pointer;
858
859                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
860                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
861                         continue;
862
863                 /* There should be an easy way to extract an integer... */
864                 obj = &(element->package.elements[1]);
865                 if (obj->type != ACPI_TYPE_INTEGER)
866                         continue;
867
868                 cx.type = obj->integer.value;
869                 /*
870                  * Some buggy BIOSes won't list C1 in _CST -
871                  * Let acpi_processor_get_power_info_default() handle them later
872                  */
873                 if (i == 1 && cx.type != ACPI_STATE_C1)
874                         current_count++;
875
876                 cx.address = reg->address;
877                 cx.index = current_count + 1;
878
879                 cx.space_id = ACPI_CSTATE_SYSTEMIO;
880                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
881                         if (acpi_processor_ffh_cstate_probe
882                                         (pr->id, &cx, reg) == 0) {
883                                 cx.space_id = ACPI_CSTATE_FFH;
884                         } else if (cx.type != ACPI_STATE_C1) {
885                                 /*
886                                  * C1 is a special case where FIXED_HARDWARE
887                                  * can be handled in non-MWAIT way as well.
888                                  * In that case, save this _CST entry info.
889                                  * That is, we retain space_id of SYSTEM_IO for
890                                  * halt based C1.
891                                  * Otherwise, ignore this info and continue.
892                                  */
893                                 continue;
894                         }
895                 }
896
897                 obj = &(element->package.elements[2]);
898                 if (obj->type != ACPI_TYPE_INTEGER)
899                         continue;
900
901                 cx.latency = obj->integer.value;
902
903                 obj = &(element->package.elements[3]);
904                 if (obj->type != ACPI_TYPE_INTEGER)
905                         continue;
906
907                 cx.power = obj->integer.value;
908
909                 current_count++;
910                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
911
912                 /*
913                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
914                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
915                  */
916                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
917                         printk(KERN_WARNING
918                                "Limiting number of power states to max (%d)\n",
919                                ACPI_PROCESSOR_MAX_POWER);
920                         printk(KERN_WARNING
921                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
922                         break;
923                 }
924         }
925
926         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
927                           current_count));
928
929         /* Validate number of power states discovered */
930         if (current_count < 2)
931                 status = -EFAULT;
932
933       end:
934         kfree(buffer.pointer);
935
936         return status;
937 }
938
939 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
940 {
941
942         if (!cx->address)
943                 return;
944
945         /*
946          * C2 latency must be less than or equal to 100
947          * microseconds.
948          */
949         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
950                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
951                                   "latency too large [%d]\n", cx->latency));
952                 return;
953         }
954
955         /*
956          * Otherwise we've met all of our C2 requirements.
957          * Normalize the C2 latency to expidite policy
958          */
959         cx->valid = 1;
960         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
961
962         return;
963 }
964
965 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
966                                            struct acpi_processor_cx *cx)
967 {
968         static int bm_check_flag;
969
970
971         if (!cx->address)
972                 return;
973
974         /*
975          * C3 latency must be less than or equal to 1000
976          * microseconds.
977          */
978         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
979                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
980                                   "latency too large [%d]\n", cx->latency));
981                 return;
982         }
983
984         /*
985          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
986          * DMA transfers are used by any ISA device to avoid livelock.
987          * Note that we could disable Type-F DMA (as recommended by
988          * the erratum), but this is known to disrupt certain ISA
989          * devices thus we take the conservative approach.
990          */
991         else if (errata.piix4.fdma) {
992                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
993                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
994                 return;
995         }
996
997         /* All the logic here assumes flags.bm_check is same across all CPUs */
998         if (!bm_check_flag) {
999                 /* Determine whether bm_check is needed based on CPU  */
1000                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
1001                 bm_check_flag = pr->flags.bm_check;
1002         } else {
1003                 pr->flags.bm_check = bm_check_flag;
1004         }
1005
1006         if (pr->flags.bm_check) {
1007                 if (!pr->flags.bm_control) {
1008                         if (pr->flags.has_cst != 1) {
1009                                 /* bus mastering control is necessary */
1010                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1011                                         "C3 support requires BM control\n"));
1012                                 return;
1013                         } else {
1014                                 /* Here we enter C3 without bus mastering */
1015                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1016                                         "C3 support without BM control\n"));
1017                         }
1018                 }
1019         } else {
1020                 /*
1021                  * WBINVD should be set in fadt, for C3 state to be
1022                  * supported on when bm_check is not required.
1023                  */
1024                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
1025                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1026                                           "Cache invalidation should work properly"
1027                                           " for C3 to be enabled on SMP systems\n"));
1028                         return;
1029                 }
1030                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
1031         }
1032
1033         /*
1034          * Otherwise we've met all of our C3 requirements.
1035          * Normalize the C3 latency to expidite policy.  Enable
1036          * checking of bus mastering status (bm_check) so we can
1037          * use this in our C3 policy
1038          */
1039         cx->valid = 1;
1040         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1041
1042         return;
1043 }
1044
1045 static int acpi_processor_power_verify(struct acpi_processor *pr)
1046 {
1047         unsigned int i;
1048         unsigned int working = 0;
1049
1050         pr->power.timer_broadcast_on_state = INT_MAX;
1051
1052         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1053                 struct acpi_processor_cx *cx = &pr->power.states[i];
1054
1055                 switch (cx->type) {
1056                 case ACPI_STATE_C1:
1057                         cx->valid = 1;
1058                         break;
1059
1060                 case ACPI_STATE_C2:
1061                         acpi_processor_power_verify_c2(cx);
1062                         if (cx->valid)
1063                                 acpi_timer_check_state(i, pr, cx);
1064                         break;
1065
1066                 case ACPI_STATE_C3:
1067                         acpi_processor_power_verify_c3(pr, cx);
1068                         if (cx->valid)
1069                                 acpi_timer_check_state(i, pr, cx);
1070                         break;
1071                 }
1072
1073                 if (cx->valid)
1074                         working++;
1075         }
1076
1077         acpi_propagate_timer_broadcast(pr);
1078
1079         return (working);
1080 }
1081
1082 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1083 {
1084         unsigned int i;
1085         int result;
1086
1087
1088         /* NOTE: the idle thread may not be running while calling
1089          * this function */
1090
1091         /* Zero initialize all the C-states info. */
1092         memset(pr->power.states, 0, sizeof(pr->power.states));
1093
1094         result = acpi_processor_get_power_info_cst(pr);
1095         if (result == -ENODEV)
1096                 result = acpi_processor_get_power_info_fadt(pr);
1097
1098         if (result)
1099                 return result;
1100
1101         acpi_processor_get_power_info_default(pr);
1102
1103         pr->power.count = acpi_processor_power_verify(pr);
1104
1105         /*
1106          * Set Default Policy
1107          * ------------------
1108          * Now that we know which states are supported, set the default
1109          * policy.  Note that this policy can be changed dynamically
1110          * (e.g. encourage deeper sleeps to conserve battery life when
1111          * not on AC).
1112          */
1113         result = acpi_processor_set_power_policy(pr);
1114         if (result)
1115                 return result;
1116
1117         /*
1118          * if one state of type C2 or C3 is available, mark this
1119          * CPU as being "idle manageable"
1120          */
1121         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1122                 if (pr->power.states[i].valid) {
1123                         pr->power.count = i;
1124                         if (pr->power.states[i].type >= ACPI_STATE_C2)
1125                                 pr->flags.power = 1;
1126                 }
1127         }
1128
1129         return 0;
1130 }
1131
1132 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1133 {
1134         int result = 0;
1135
1136
1137         if (!pr)
1138                 return -EINVAL;
1139
1140         if (nocst) {
1141                 return -ENODEV;
1142         }
1143
1144         if (!pr->flags.power_setup_done)
1145                 return -ENODEV;
1146
1147         /* Fall back to the default idle loop */
1148         pm_idle = pm_idle_save;
1149         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
1150
1151         pr->flags.power = 0;
1152         result = acpi_processor_get_power_info(pr);
1153         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1154                 pm_idle = acpi_processor_idle;
1155
1156         return result;
1157 }
1158
1159 /* proc interface */
1160
1161 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1162 {
1163         struct acpi_processor *pr = seq->private;
1164         unsigned int i;
1165
1166
1167         if (!pr)
1168                 goto end;
1169
1170         seq_printf(seq, "active state:            C%zd\n"
1171                    "max_cstate:              C%d\n"
1172                    "bus master activity:     %08x\n"
1173                    "maximum allowed latency: %d usec\n",
1174                    pr->power.state ? pr->power.state - pr->power.states : 0,
1175                    max_cstate, (unsigned)pr->power.bm_activity,
1176                    system_latency_constraint());
1177
1178         seq_puts(seq, "states:\n");
1179
1180         for (i = 1; i <= pr->power.count; i++) {
1181                 seq_printf(seq, "   %cC%d:                  ",
1182                            (&pr->power.states[i] ==
1183                             pr->power.state ? '*' : ' '), i);
1184
1185                 if (!pr->power.states[i].valid) {
1186                         seq_puts(seq, "<not supported>\n");
1187                         continue;
1188                 }
1189
1190                 switch (pr->power.states[i].type) {
1191                 case ACPI_STATE_C1:
1192                         seq_printf(seq, "type[C1] ");
1193                         break;
1194                 case ACPI_STATE_C2:
1195                         seq_printf(seq, "type[C2] ");
1196                         break;
1197                 case ACPI_STATE_C3:
1198                         seq_printf(seq, "type[C3] ");
1199                         break;
1200                 default:
1201                         seq_printf(seq, "type[--] ");
1202                         break;
1203                 }
1204
1205                 if (pr->power.states[i].promotion.state)
1206                         seq_printf(seq, "promotion[C%zd] ",
1207                                    (pr->power.states[i].promotion.state -
1208                                     pr->power.states));
1209                 else
1210                         seq_puts(seq, "promotion[--] ");
1211
1212                 if (pr->power.states[i].demotion.state)
1213                         seq_printf(seq, "demotion[C%zd] ",
1214                                    (pr->power.states[i].demotion.state -
1215                                     pr->power.states));
1216                 else
1217                         seq_puts(seq, "demotion[--] ");
1218
1219                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1220                            pr->power.states[i].latency,
1221                            pr->power.states[i].usage,
1222                            (unsigned long long)pr->power.states[i].time);
1223         }
1224
1225       end:
1226         return 0;
1227 }
1228
1229 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1230 {
1231         return single_open(file, acpi_processor_power_seq_show,
1232                            PDE(inode)->data);
1233 }
1234
1235 static const struct file_operations acpi_processor_power_fops = {
1236         .open = acpi_processor_power_open_fs,
1237         .read = seq_read,
1238         .llseek = seq_lseek,
1239         .release = single_release,
1240 };
1241
1242 #ifdef CONFIG_SMP
1243 static void smp_callback(void *v)
1244 {
1245         /* we already woke the CPU up, nothing more to do */
1246 }
1247
1248 /*
1249  * This function gets called when a part of the kernel has a new latency
1250  * requirement.  This means we need to get all processors out of their C-state,
1251  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1252  * wakes them all right up.
1253  */
1254 static int acpi_processor_latency_notify(struct notifier_block *b,
1255                 unsigned long l, void *v)
1256 {
1257         smp_call_function(smp_callback, NULL, 0, 1);
1258         return NOTIFY_OK;
1259 }
1260
1261 static struct notifier_block acpi_processor_latency_notifier = {
1262         .notifier_call = acpi_processor_latency_notify,
1263 };
1264 #endif
1265
1266 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1267                               struct acpi_device *device)
1268 {
1269         acpi_status status = 0;
1270         static int first_run;
1271         struct proc_dir_entry *entry = NULL;
1272         unsigned int i;
1273
1274
1275         if (!first_run) {
1276                 dmi_check_system(processor_power_dmi_table);
1277                 if (max_cstate < ACPI_C_STATES_MAX)
1278                         printk(KERN_NOTICE
1279                                "ACPI: processor limited to max C-state %d\n",
1280                                max_cstate);
1281                 first_run++;
1282 #ifdef CONFIG_SMP
1283                 register_latency_notifier(&acpi_processor_latency_notifier);
1284 #endif
1285         }
1286
1287         if (!pr)
1288                 return -EINVAL;
1289
1290         if (acpi_gbl_FADT.cst_control && !nocst) {
1291                 status =
1292                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1293                 if (ACPI_FAILURE(status)) {
1294                         ACPI_EXCEPTION((AE_INFO, status,
1295                                         "Notifying BIOS of _CST ability failed"));
1296                 }
1297         }
1298
1299         acpi_processor_get_power_info(pr);
1300
1301         /*
1302          * Install the idle handler if processor power management is supported.
1303          * Note that we use previously set idle handler will be used on
1304          * platforms that only support C1.
1305          */
1306         if ((pr->flags.power) && (!boot_option_idle_override)) {
1307                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1308                 for (i = 1; i <= pr->power.count; i++)
1309                         if (pr->power.states[i].valid)
1310                                 printk(" C%d[C%d]", i,
1311                                        pr->power.states[i].type);
1312                 printk(")\n");
1313
1314                 if (pr->id == 0) {
1315                         pm_idle_save = pm_idle;
1316                         pm_idle = acpi_processor_idle;
1317                 }
1318         }
1319
1320         /* 'power' [R] */
1321         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1322                                   S_IRUGO, acpi_device_dir(device));
1323         if (!entry)
1324                 return -EIO;
1325         else {
1326                 entry->proc_fops = &acpi_processor_power_fops;
1327                 entry->data = acpi_driver_data(device);
1328                 entry->owner = THIS_MODULE;
1329         }
1330
1331         pr->flags.power_setup_done = 1;
1332
1333         return 0;
1334 }
1335
1336 int acpi_processor_power_exit(struct acpi_processor *pr,
1337                               struct acpi_device *device)
1338 {
1339
1340         pr->flags.power_setup_done = 0;
1341
1342         if (acpi_device_dir(device))
1343                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1344                                   acpi_device_dir(device));
1345
1346         /* Unregister the idle handler when processor #0 is removed. */
1347         if (pr->id == 0) {
1348                 pm_idle = pm_idle_save;
1349
1350                 /*
1351                  * We are about to unload the current idle thread pm callback
1352                  * (pm_idle), Wait for all processors to update cached/local
1353                  * copies of pm_idle before proceeding.
1354                  */
1355                 cpu_idle_wait();
1356 #ifdef CONFIG_SMP
1357                 unregister_latency_notifier(&acpi_processor_latency_notifier);
1358 #endif
1359         }
1360
1361         return 0;
1362 }