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