tools headers UAPI: Sync files changed by the quotactl_path unwiring
[linux-2.6-microblaze.git] / drivers / acpi / processor_idle.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * processor_idle - idle state submodule to the ACPI processor driver
4  *
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9  *                      - Added processor hotplug support
10  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
11  *                      - Added support for C3 on SMP
12  */
13 #define pr_fmt(fmt) "ACPI: " fmt
14
15 #include <linux/module.h>
16 #include <linux/acpi.h>
17 #include <linux/dmi.h>
18 #include <linux/sched.h>       /* need_resched() */
19 #include <linux/tick.h>
20 #include <linux/cpuidle.h>
21 #include <linux/cpu.h>
22 #include <acpi/processor.h>
23
24 /*
25  * Include the apic definitions for x86 to have the APIC timer related defines
26  * available also for UP (on SMP it gets magically included via linux/smp.h).
27  * asm/acpi.h is not an option, as it would require more include magic. Also
28  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
29  */
30 #ifdef CONFIG_X86
31 #include <asm/apic.h>
32 #include <asm/cpu.h>
33 #endif
34
35 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
36
37 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
38 module_param(max_cstate, uint, 0000);
39 static unsigned int nocst __read_mostly;
40 module_param(nocst, uint, 0000);
41 static int bm_check_disable __read_mostly;
42 module_param(bm_check_disable, uint, 0000);
43
44 static unsigned int latency_factor __read_mostly = 2;
45 module_param(latency_factor, uint, 0644);
46
47 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
48
49 struct cpuidle_driver acpi_idle_driver = {
50         .name =         "acpi_idle",
51         .owner =        THIS_MODULE,
52 };
53
54 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
55 static
56 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
57
58 static int disabled_by_idle_boot_param(void)
59 {
60         return boot_option_idle_override == IDLE_POLL ||
61                 boot_option_idle_override == IDLE_HALT;
62 }
63
64 /*
65  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
66  * For now disable this. Probably a bug somewhere else.
67  *
68  * To skip this limit, boot/load with a large max_cstate limit.
69  */
70 static int set_max_cstate(const struct dmi_system_id *id)
71 {
72         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
73                 return 0;
74
75         pr_notice("%s detected - limiting to C%ld max_cstate."
76                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
77                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
78
79         max_cstate = (long)id->driver_data;
80
81         return 0;
82 }
83
84 static const struct dmi_system_id processor_power_dmi_table[] = {
85         { set_max_cstate, "Clevo 5600D", {
86           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
87           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
88          (void *)2},
89         { set_max_cstate, "Pavilion zv5000", {
90           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
91           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
92          (void *)1},
93         { set_max_cstate, "Asus L8400B", {
94           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
95           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
96          (void *)1},
97         {},
98 };
99
100
101 /*
102  * Callers should disable interrupts before the call and enable
103  * interrupts after return.
104  */
105 static void __cpuidle acpi_safe_halt(void)
106 {
107         if (!tif_need_resched()) {
108                 safe_halt();
109                 local_irq_disable();
110         }
111 }
112
113 #ifdef ARCH_APICTIMER_STOPS_ON_C3
114
115 /*
116  * Some BIOS implementations switch to C3 in the published C2 state.
117  * This seems to be a common problem on AMD boxen, but other vendors
118  * are affected too. We pick the most conservative approach: we assume
119  * that the local APIC stops in both C2 and C3.
120  */
121 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
122                                    struct acpi_processor_cx *cx)
123 {
124         struct acpi_processor_power *pwr = &pr->power;
125         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
126
127         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
128                 return;
129
130         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
131                 type = ACPI_STATE_C1;
132
133         /*
134          * Check, if one of the previous states already marked the lapic
135          * unstable
136          */
137         if (pwr->timer_broadcast_on_state < state)
138                 return;
139
140         if (cx->type >= type)
141                 pr->power.timer_broadcast_on_state = state;
142 }
143
144 static void __lapic_timer_propagate_broadcast(void *arg)
145 {
146         struct acpi_processor *pr = (struct acpi_processor *) arg;
147
148         if (pr->power.timer_broadcast_on_state < INT_MAX)
149                 tick_broadcast_enable();
150         else
151                 tick_broadcast_disable();
152 }
153
154 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
155 {
156         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
157                                  (void *)pr, 1);
158 }
159
160 /* Power(C) State timer broadcast control */
161 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
162                                         struct acpi_processor_cx *cx)
163 {
164         return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
165 }
166
167 #else
168
169 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
170                                    struct acpi_processor_cx *cstate) { }
171 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
172
173 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
174                                         struct acpi_processor_cx *cx)
175 {
176         return false;
177 }
178
179 #endif
180
181 #if defined(CONFIG_X86)
182 static void tsc_check_state(int state)
183 {
184         switch (boot_cpu_data.x86_vendor) {
185         case X86_VENDOR_HYGON:
186         case X86_VENDOR_AMD:
187         case X86_VENDOR_INTEL:
188         case X86_VENDOR_CENTAUR:
189         case X86_VENDOR_ZHAOXIN:
190                 /*
191                  * AMD Fam10h TSC will tick in all
192                  * C/P/S0/S1 states when this bit is set.
193                  */
194                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
195                         return;
196                 fallthrough;
197         default:
198                 /* TSC could halt in idle, so notify users */
199                 if (state > ACPI_STATE_C1)
200                         mark_tsc_unstable("TSC halts in idle");
201         }
202 }
203 #else
204 static void tsc_check_state(int state) { return; }
205 #endif
206
207 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
208 {
209
210         if (!pr->pblk)
211                 return -ENODEV;
212
213         /* if info is obtained from pblk/fadt, type equals state */
214         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
215         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
216
217 #ifndef CONFIG_HOTPLUG_CPU
218         /*
219          * Check for P_LVL2_UP flag before entering C2 and above on
220          * an SMP system.
221          */
222         if ((num_online_cpus() > 1) &&
223             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
224                 return -ENODEV;
225 #endif
226
227         /* determine C2 and C3 address from pblk */
228         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
229         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
230
231         /* determine latencies from FADT */
232         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
233         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
234
235         /*
236          * FADT specified C2 latency must be less than or equal to
237          * 100 microseconds.
238          */
239         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
240                 acpi_handle_debug(pr->handle, "C2 latency too large [%d]\n",
241                                   acpi_gbl_FADT.c2_latency);
242                 /* invalidate C2 */
243                 pr->power.states[ACPI_STATE_C2].address = 0;
244         }
245
246         /*
247          * FADT supplied C3 latency must be less than or equal to
248          * 1000 microseconds.
249          */
250         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
251                 acpi_handle_debug(pr->handle, "C3 latency too large [%d]\n",
252                                   acpi_gbl_FADT.c3_latency);
253                 /* invalidate C3 */
254                 pr->power.states[ACPI_STATE_C3].address = 0;
255         }
256
257         acpi_handle_debug(pr->handle, "lvl2[0x%08x] lvl3[0x%08x]\n",
258                           pr->power.states[ACPI_STATE_C2].address,
259                           pr->power.states[ACPI_STATE_C3].address);
260
261         snprintf(pr->power.states[ACPI_STATE_C2].desc,
262                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
263                          pr->power.states[ACPI_STATE_C2].address);
264         snprintf(pr->power.states[ACPI_STATE_C3].desc,
265                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
266                          pr->power.states[ACPI_STATE_C3].address);
267
268         return 0;
269 }
270
271 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
272 {
273         if (!pr->power.states[ACPI_STATE_C1].valid) {
274                 /* set the first C-State to C1 */
275                 /* all processors need to support C1 */
276                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
277                 pr->power.states[ACPI_STATE_C1].valid = 1;
278                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
279
280                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
281                          ACPI_CX_DESC_LEN, "ACPI HLT");
282         }
283         /* the C0 state only exists as a filler in our array */
284         pr->power.states[ACPI_STATE_C0].valid = 1;
285         return 0;
286 }
287
288 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
289 {
290         int ret;
291
292         if (nocst)
293                 return -ENODEV;
294
295         ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
296         if (ret)
297                 return ret;
298
299         if (!pr->power.count)
300                 return -EFAULT;
301
302         pr->flags.has_cst = 1;
303         return 0;
304 }
305
306 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
307                                            struct acpi_processor_cx *cx)
308 {
309         static int bm_check_flag = -1;
310         static int bm_control_flag = -1;
311
312
313         if (!cx->address)
314                 return;
315
316         /*
317          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
318          * DMA transfers are used by any ISA device to avoid livelock.
319          * Note that we could disable Type-F DMA (as recommended by
320          * the erratum), but this is known to disrupt certain ISA
321          * devices thus we take the conservative approach.
322          */
323         else if (errata.piix4.fdma) {
324                 acpi_handle_debug(pr->handle,
325                                   "C3 not supported on PIIX4 with Type-F DMA\n");
326                 return;
327         }
328
329         /* All the logic here assumes flags.bm_check is same across all CPUs */
330         if (bm_check_flag == -1) {
331                 /* Determine whether bm_check is needed based on CPU  */
332                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
333                 bm_check_flag = pr->flags.bm_check;
334                 bm_control_flag = pr->flags.bm_control;
335         } else {
336                 pr->flags.bm_check = bm_check_flag;
337                 pr->flags.bm_control = bm_control_flag;
338         }
339
340         if (pr->flags.bm_check) {
341                 if (!pr->flags.bm_control) {
342                         if (pr->flags.has_cst != 1) {
343                                 /* bus mastering control is necessary */
344                                 acpi_handle_debug(pr->handle,
345                                                   "C3 support requires BM control\n");
346                                 return;
347                         } else {
348                                 /* Here we enter C3 without bus mastering */
349                                 acpi_handle_debug(pr->handle,
350                                                   "C3 support without BM control\n");
351                         }
352                 }
353         } else {
354                 /*
355                  * WBINVD should be set in fadt, for C3 state to be
356                  * supported on when bm_check is not required.
357                  */
358                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
359                         acpi_handle_debug(pr->handle,
360                                           "Cache invalidation should work properly"
361                                           " for C3 to be enabled on SMP systems\n");
362                         return;
363                 }
364         }
365
366         /*
367          * Otherwise we've met all of our C3 requirements.
368          * Normalize the C3 latency to expidite policy.  Enable
369          * checking of bus mastering status (bm_check) so we can
370          * use this in our C3 policy
371          */
372         cx->valid = 1;
373
374         /*
375          * On older chipsets, BM_RLD needs to be set
376          * in order for Bus Master activity to wake the
377          * system from C3.  Newer chipsets handle DMA
378          * during C3 automatically and BM_RLD is a NOP.
379          * In either case, the proper way to
380          * handle BM_RLD is to set it and leave it set.
381          */
382         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
383
384         return;
385 }
386
387 static int acpi_processor_power_verify(struct acpi_processor *pr)
388 {
389         unsigned int i;
390         unsigned int working = 0;
391
392         pr->power.timer_broadcast_on_state = INT_MAX;
393
394         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
395                 struct acpi_processor_cx *cx = &pr->power.states[i];
396
397                 switch (cx->type) {
398                 case ACPI_STATE_C1:
399                         cx->valid = 1;
400                         break;
401
402                 case ACPI_STATE_C2:
403                         if (!cx->address)
404                                 break;
405                         cx->valid = 1;
406                         break;
407
408                 case ACPI_STATE_C3:
409                         acpi_processor_power_verify_c3(pr, cx);
410                         break;
411                 }
412                 if (!cx->valid)
413                         continue;
414
415                 lapic_timer_check_state(i, pr, cx);
416                 tsc_check_state(cx->type);
417                 working++;
418         }
419
420         lapic_timer_propagate_broadcast(pr);
421
422         return (working);
423 }
424
425 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
426 {
427         unsigned int i;
428         int result;
429
430
431         /* NOTE: the idle thread may not be running while calling
432          * this function */
433
434         /* Zero initialize all the C-states info. */
435         memset(pr->power.states, 0, sizeof(pr->power.states));
436
437         result = acpi_processor_get_power_info_cst(pr);
438         if (result == -ENODEV)
439                 result = acpi_processor_get_power_info_fadt(pr);
440
441         if (result)
442                 return result;
443
444         acpi_processor_get_power_info_default(pr);
445
446         pr->power.count = acpi_processor_power_verify(pr);
447
448         /*
449          * if one state of type C2 or C3 is available, mark this
450          * CPU as being "idle manageable"
451          */
452         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
453                 if (pr->power.states[i].valid) {
454                         pr->power.count = i;
455                         pr->flags.power = 1;
456                 }
457         }
458
459         return 0;
460 }
461
462 /**
463  * acpi_idle_bm_check - checks if bus master activity was detected
464  */
465 static int acpi_idle_bm_check(void)
466 {
467         u32 bm_status = 0;
468
469         if (bm_check_disable)
470                 return 0;
471
472         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
473         if (bm_status)
474                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
475         /*
476          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
477          * the true state of bus mastering activity; forcing us to
478          * manually check the BMIDEA bit of each IDE channel.
479          */
480         else if (errata.piix4.bmisx) {
481                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
482                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
483                         bm_status = 1;
484         }
485         return bm_status;
486 }
487
488 static void wait_for_freeze(void)
489 {
490 #ifdef  CONFIG_X86
491         /* No delay is needed if we are in guest */
492         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
493                 return;
494 #endif
495         /* Dummy wait op - must do something useless after P_LVL2 read
496            because chipsets cannot guarantee that STPCLK# signal
497            gets asserted in time to freeze execution properly. */
498         inl(acpi_gbl_FADT.xpm_timer_block.address);
499 }
500
501 /**
502  * acpi_idle_do_entry - enter idle state using the appropriate method
503  * @cx: cstate data
504  *
505  * Caller disables interrupt before call and enables interrupt after return.
506  */
507 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
508 {
509         if (cx->entry_method == ACPI_CSTATE_FFH) {
510                 /* Call into architectural FFH based C-state */
511                 acpi_processor_ffh_cstate_enter(cx);
512         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
513                 acpi_safe_halt();
514         } else {
515                 /* IO port based C-state */
516                 inb(cx->address);
517                 wait_for_freeze();
518         }
519 }
520
521 /**
522  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
523  * @dev: the target CPU
524  * @index: the index of suggested state
525  */
526 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
527 {
528         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
529
530         ACPI_FLUSH_CPU_CACHE();
531
532         while (1) {
533
534                 if (cx->entry_method == ACPI_CSTATE_HALT)
535                         safe_halt();
536                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
537                         inb(cx->address);
538                         wait_for_freeze();
539                 } else
540                         return -ENODEV;
541
542 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
543                 cond_wakeup_cpu0();
544 #endif
545         }
546
547         /* Never reached */
548         return 0;
549 }
550
551 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
552 {
553         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
554                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
555 }
556
557 static int c3_cpu_count;
558 static DEFINE_RAW_SPINLOCK(c3_lock);
559
560 /**
561  * acpi_idle_enter_bm - enters C3 with proper BM handling
562  * @drv: cpuidle driver
563  * @pr: Target processor
564  * @cx: Target state context
565  * @index: index of target state
566  */
567 static int acpi_idle_enter_bm(struct cpuidle_driver *drv,
568                                struct acpi_processor *pr,
569                                struct acpi_processor_cx *cx,
570                                int index)
571 {
572         static struct acpi_processor_cx safe_cx = {
573                 .entry_method = ACPI_CSTATE_HALT,
574         };
575
576         /*
577          * disable bus master
578          * bm_check implies we need ARB_DIS
579          * bm_control implies whether we can do ARB_DIS
580          *
581          * That leaves a case where bm_check is set and bm_control is not set.
582          * In that case we cannot do much, we enter C3 without doing anything.
583          */
584         bool dis_bm = pr->flags.bm_control;
585
586         /* If we can skip BM, demote to a safe state. */
587         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
588                 dis_bm = false;
589                 index = drv->safe_state_index;
590                 if (index >= 0) {
591                         cx = this_cpu_read(acpi_cstate[index]);
592                 } else {
593                         cx = &safe_cx;
594                         index = -EBUSY;
595                 }
596         }
597
598         if (dis_bm) {
599                 raw_spin_lock(&c3_lock);
600                 c3_cpu_count++;
601                 /* Disable bus master arbitration when all CPUs are in C3 */
602                 if (c3_cpu_count == num_online_cpus())
603                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
604                 raw_spin_unlock(&c3_lock);
605         }
606
607         rcu_idle_enter();
608
609         acpi_idle_do_entry(cx);
610
611         rcu_idle_exit();
612
613         /* Re-enable bus master arbitration */
614         if (dis_bm) {
615                 raw_spin_lock(&c3_lock);
616                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
617                 c3_cpu_count--;
618                 raw_spin_unlock(&c3_lock);
619         }
620
621         return index;
622 }
623
624 static int acpi_idle_enter(struct cpuidle_device *dev,
625                            struct cpuidle_driver *drv, int index)
626 {
627         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
628         struct acpi_processor *pr;
629
630         pr = __this_cpu_read(processors);
631         if (unlikely(!pr))
632                 return -EINVAL;
633
634         if (cx->type != ACPI_STATE_C1) {
635                 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
636                         return acpi_idle_enter_bm(drv, pr, cx, index);
637
638                 /* C2 to C1 demotion. */
639                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
640                         index = ACPI_IDLE_STATE_START;
641                         cx = per_cpu(acpi_cstate[index], dev->cpu);
642                 }
643         }
644
645         if (cx->type == ACPI_STATE_C3)
646                 ACPI_FLUSH_CPU_CACHE();
647
648         acpi_idle_do_entry(cx);
649
650         return index;
651 }
652
653 static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
654                                   struct cpuidle_driver *drv, int index)
655 {
656         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
657
658         if (cx->type == ACPI_STATE_C3) {
659                 struct acpi_processor *pr = __this_cpu_read(processors);
660
661                 if (unlikely(!pr))
662                         return 0;
663
664                 if (pr->flags.bm_check) {
665                         u8 bm_sts_skip = cx->bm_sts_skip;
666
667                         /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
668                         cx->bm_sts_skip = 1;
669                         acpi_idle_enter_bm(drv, pr, cx, index);
670                         cx->bm_sts_skip = bm_sts_skip;
671
672                         return 0;
673                 } else {
674                         ACPI_FLUSH_CPU_CACHE();
675                 }
676         }
677         acpi_idle_do_entry(cx);
678
679         return 0;
680 }
681
682 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
683                                            struct cpuidle_device *dev)
684 {
685         int i, count = ACPI_IDLE_STATE_START;
686         struct acpi_processor_cx *cx;
687         struct cpuidle_state *state;
688
689         if (max_cstate == 0)
690                 max_cstate = 1;
691
692         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
693                 state = &acpi_idle_driver.states[count];
694                 cx = &pr->power.states[i];
695
696                 if (!cx->valid)
697                         continue;
698
699                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
700
701                 if (lapic_timer_needs_broadcast(pr, cx))
702                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
703
704                 if (cx->type == ACPI_STATE_C3) {
705                         state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
706                         if (pr->flags.bm_check)
707                                 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
708                 }
709
710                 count++;
711                 if (count == CPUIDLE_STATE_MAX)
712                         break;
713         }
714
715         if (!count)
716                 return -EINVAL;
717
718         return 0;
719 }
720
721 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
722 {
723         int i, count;
724         struct acpi_processor_cx *cx;
725         struct cpuidle_state *state;
726         struct cpuidle_driver *drv = &acpi_idle_driver;
727
728         if (max_cstate == 0)
729                 max_cstate = 1;
730
731         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
732                 cpuidle_poll_state_init(drv);
733                 count = 1;
734         } else {
735                 count = 0;
736         }
737
738         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
739                 cx = &pr->power.states[i];
740
741                 if (!cx->valid)
742                         continue;
743
744                 state = &drv->states[count];
745                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
746                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
747                 state->exit_latency = cx->latency;
748                 state->target_residency = cx->latency * latency_factor;
749                 state->enter = acpi_idle_enter;
750
751                 state->flags = 0;
752                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
753                         state->enter_dead = acpi_idle_play_dead;
754                         drv->safe_state_index = count;
755                 }
756                 /*
757                  * Halt-induced C1 is not good for ->enter_s2idle, because it
758                  * re-enables interrupts on exit.  Moreover, C1 is generally not
759                  * particularly interesting from the suspend-to-idle angle, so
760                  * avoid C1 and the situations in which we may need to fall back
761                  * to it altogether.
762                  */
763                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
764                         state->enter_s2idle = acpi_idle_enter_s2idle;
765
766                 count++;
767                 if (count == CPUIDLE_STATE_MAX)
768                         break;
769         }
770
771         drv->state_count = count;
772
773         if (!count)
774                 return -EINVAL;
775
776         return 0;
777 }
778
779 static inline void acpi_processor_cstate_first_run_checks(void)
780 {
781         static int first_run;
782
783         if (first_run)
784                 return;
785         dmi_check_system(processor_power_dmi_table);
786         max_cstate = acpi_processor_cstate_check(max_cstate);
787         if (max_cstate < ACPI_C_STATES_MAX)
788                 pr_notice("processor limited to max C-state %d\n", max_cstate);
789
790         first_run++;
791
792         if (nocst)
793                 return;
794
795         acpi_processor_claim_cst_control();
796 }
797 #else
798
799 static inline int disabled_by_idle_boot_param(void) { return 0; }
800 static inline void acpi_processor_cstate_first_run_checks(void) { }
801 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
802 {
803         return -ENODEV;
804 }
805
806 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
807                                            struct cpuidle_device *dev)
808 {
809         return -EINVAL;
810 }
811
812 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
813 {
814         return -EINVAL;
815 }
816
817 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
818
819 struct acpi_lpi_states_array {
820         unsigned int size;
821         unsigned int composite_states_size;
822         struct acpi_lpi_state *entries;
823         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
824 };
825
826 static int obj_get_integer(union acpi_object *obj, u32 *value)
827 {
828         if (obj->type != ACPI_TYPE_INTEGER)
829                 return -EINVAL;
830
831         *value = obj->integer.value;
832         return 0;
833 }
834
835 static int acpi_processor_evaluate_lpi(acpi_handle handle,
836                                        struct acpi_lpi_states_array *info)
837 {
838         acpi_status status;
839         int ret = 0;
840         int pkg_count, state_idx = 1, loop;
841         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
842         union acpi_object *lpi_data;
843         struct acpi_lpi_state *lpi_state;
844
845         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
846         if (ACPI_FAILURE(status)) {
847                 acpi_handle_debug(handle, "No _LPI, giving up\n");
848                 return -ENODEV;
849         }
850
851         lpi_data = buffer.pointer;
852
853         /* There must be at least 4 elements = 3 elements + 1 package */
854         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
855             lpi_data->package.count < 4) {
856                 pr_debug("not enough elements in _LPI\n");
857                 ret = -ENODATA;
858                 goto end;
859         }
860
861         pkg_count = lpi_data->package.elements[2].integer.value;
862
863         /* Validate number of power states. */
864         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
865                 pr_debug("count given by _LPI is not valid\n");
866                 ret = -ENODATA;
867                 goto end;
868         }
869
870         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
871         if (!lpi_state) {
872                 ret = -ENOMEM;
873                 goto end;
874         }
875
876         info->size = pkg_count;
877         info->entries = lpi_state;
878
879         /* LPI States start at index 3 */
880         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
881                 union acpi_object *element, *pkg_elem, *obj;
882
883                 element = &lpi_data->package.elements[loop];
884                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
885                         continue;
886
887                 pkg_elem = element->package.elements;
888
889                 obj = pkg_elem + 6;
890                 if (obj->type == ACPI_TYPE_BUFFER) {
891                         struct acpi_power_register *reg;
892
893                         reg = (struct acpi_power_register *)obj->buffer.pointer;
894                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
895                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
896                                 continue;
897
898                         lpi_state->address = reg->address;
899                         lpi_state->entry_method =
900                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
901                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
902                 } else if (obj->type == ACPI_TYPE_INTEGER) {
903                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
904                         lpi_state->address = obj->integer.value;
905                 } else {
906                         continue;
907                 }
908
909                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
910
911                 obj = pkg_elem + 9;
912                 if (obj->type == ACPI_TYPE_STRING)
913                         strlcpy(lpi_state->desc, obj->string.pointer,
914                                 ACPI_CX_DESC_LEN);
915
916                 lpi_state->index = state_idx;
917                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
918                         pr_debug("No min. residency found, assuming 10 us\n");
919                         lpi_state->min_residency = 10;
920                 }
921
922                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
923                         pr_debug("No wakeup residency found, assuming 10 us\n");
924                         lpi_state->wake_latency = 10;
925                 }
926
927                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
928                         lpi_state->flags = 0;
929
930                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
931                         lpi_state->arch_flags = 0;
932
933                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
934                         lpi_state->res_cnt_freq = 1;
935
936                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
937                         lpi_state->enable_parent_state = 0;
938         }
939
940         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
941 end:
942         kfree(buffer.pointer);
943         return ret;
944 }
945
946 /*
947  * flat_state_cnt - the number of composite LPI states after the process of flattening
948  */
949 static int flat_state_cnt;
950
951 /**
952  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
953  *
954  * @local: local LPI state
955  * @parent: parent LPI state
956  * @result: composite LPI state
957  */
958 static bool combine_lpi_states(struct acpi_lpi_state *local,
959                                struct acpi_lpi_state *parent,
960                                struct acpi_lpi_state *result)
961 {
962         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
963                 if (!parent->address) /* 0 means autopromotable */
964                         return false;
965                 result->address = local->address + parent->address;
966         } else {
967                 result->address = parent->address;
968         }
969
970         result->min_residency = max(local->min_residency, parent->min_residency);
971         result->wake_latency = local->wake_latency + parent->wake_latency;
972         result->enable_parent_state = parent->enable_parent_state;
973         result->entry_method = local->entry_method;
974
975         result->flags = parent->flags;
976         result->arch_flags = parent->arch_flags;
977         result->index = parent->index;
978
979         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
980         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
981         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
982         return true;
983 }
984
985 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
986
987 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
988                                   struct acpi_lpi_state *t)
989 {
990         curr_level->composite_states[curr_level->composite_states_size++] = t;
991 }
992
993 static int flatten_lpi_states(struct acpi_processor *pr,
994                               struct acpi_lpi_states_array *curr_level,
995                               struct acpi_lpi_states_array *prev_level)
996 {
997         int i, j, state_count = curr_level->size;
998         struct acpi_lpi_state *p, *t = curr_level->entries;
999
1000         curr_level->composite_states_size = 0;
1001         for (j = 0; j < state_count; j++, t++) {
1002                 struct acpi_lpi_state *flpi;
1003
1004                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1005                         continue;
1006
1007                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1008                         pr_warn("Limiting number of LPI states to max (%d)\n",
1009                                 ACPI_PROCESSOR_MAX_POWER);
1010                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1011                         break;
1012                 }
1013
1014                 flpi = &pr->power.lpi_states[flat_state_cnt];
1015
1016                 if (!prev_level) { /* leaf/processor node */
1017                         memcpy(flpi, t, sizeof(*t));
1018                         stash_composite_state(curr_level, flpi);
1019                         flat_state_cnt++;
1020                         continue;
1021                 }
1022
1023                 for (i = 0; i < prev_level->composite_states_size; i++) {
1024                         p = prev_level->composite_states[i];
1025                         if (t->index <= p->enable_parent_state &&
1026                             combine_lpi_states(p, t, flpi)) {
1027                                 stash_composite_state(curr_level, flpi);
1028                                 flat_state_cnt++;
1029                                 flpi++;
1030                         }
1031                 }
1032         }
1033
1034         kfree(curr_level->entries);
1035         return 0;
1036 }
1037
1038 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1039 {
1040         int ret, i;
1041         acpi_status status;
1042         acpi_handle handle = pr->handle, pr_ahandle;
1043         struct acpi_device *d = NULL;
1044         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1045
1046         if (!osc_pc_lpi_support_confirmed)
1047                 return -EOPNOTSUPP;
1048
1049         if (!acpi_has_method(handle, "_LPI"))
1050                 return -EINVAL;
1051
1052         flat_state_cnt = 0;
1053         prev = &info[0];
1054         curr = &info[1];
1055         handle = pr->handle;
1056         ret = acpi_processor_evaluate_lpi(handle, prev);
1057         if (ret)
1058                 return ret;
1059         flatten_lpi_states(pr, prev, NULL);
1060
1061         status = acpi_get_parent(handle, &pr_ahandle);
1062         while (ACPI_SUCCESS(status)) {
1063                 acpi_bus_get_device(pr_ahandle, &d);
1064                 handle = pr_ahandle;
1065
1066                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1067                         break;
1068
1069                 /* can be optional ? */
1070                 if (!acpi_has_method(handle, "_LPI"))
1071                         break;
1072
1073                 ret = acpi_processor_evaluate_lpi(handle, curr);
1074                 if (ret)
1075                         break;
1076
1077                 /* flatten all the LPI states in this level of hierarchy */
1078                 flatten_lpi_states(pr, curr, prev);
1079
1080                 tmp = prev, prev = curr, curr = tmp;
1081
1082                 status = acpi_get_parent(handle, &pr_ahandle);
1083         }
1084
1085         pr->power.count = flat_state_cnt;
1086         /* reset the index after flattening */
1087         for (i = 0; i < pr->power.count; i++)
1088                 pr->power.lpi_states[i].index = i;
1089
1090         /* Tell driver that _LPI is supported. */
1091         pr->flags.has_lpi = 1;
1092         pr->flags.power = 1;
1093
1094         return 0;
1095 }
1096
1097 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1098 {
1099         return -ENODEV;
1100 }
1101
1102 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1103 {
1104         return -ENODEV;
1105 }
1106
1107 /**
1108  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1109  * @dev: the target CPU
1110  * @drv: cpuidle driver containing cpuidle state info
1111  * @index: index of target state
1112  *
1113  * Return: 0 for success or negative value for error
1114  */
1115 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1116                                struct cpuidle_driver *drv, int index)
1117 {
1118         struct acpi_processor *pr;
1119         struct acpi_lpi_state *lpi;
1120
1121         pr = __this_cpu_read(processors);
1122
1123         if (unlikely(!pr))
1124                 return -EINVAL;
1125
1126         lpi = &pr->power.lpi_states[index];
1127         if (lpi->entry_method == ACPI_CSTATE_FFH)
1128                 return acpi_processor_ffh_lpi_enter(lpi);
1129
1130         return -EINVAL;
1131 }
1132
1133 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1134 {
1135         int i;
1136         struct acpi_lpi_state *lpi;
1137         struct cpuidle_state *state;
1138         struct cpuidle_driver *drv = &acpi_idle_driver;
1139
1140         if (!pr->flags.has_lpi)
1141                 return -EOPNOTSUPP;
1142
1143         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1144                 lpi = &pr->power.lpi_states[i];
1145
1146                 state = &drv->states[i];
1147                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1148                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1149                 state->exit_latency = lpi->wake_latency;
1150                 state->target_residency = lpi->min_residency;
1151                 if (lpi->arch_flags)
1152                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1153                 state->enter = acpi_idle_lpi_enter;
1154                 drv->safe_state_index = i;
1155         }
1156
1157         drv->state_count = i;
1158
1159         return 0;
1160 }
1161
1162 /**
1163  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1164  * global state data i.e. idle routines
1165  *
1166  * @pr: the ACPI processor
1167  */
1168 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1169 {
1170         int i;
1171         struct cpuidle_driver *drv = &acpi_idle_driver;
1172
1173         if (!pr->flags.power_setup_done || !pr->flags.power)
1174                 return -EINVAL;
1175
1176         drv->safe_state_index = -1;
1177         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1178                 drv->states[i].name[0] = '\0';
1179                 drv->states[i].desc[0] = '\0';
1180         }
1181
1182         if (pr->flags.has_lpi)
1183                 return acpi_processor_setup_lpi_states(pr);
1184
1185         return acpi_processor_setup_cstates(pr);
1186 }
1187
1188 /**
1189  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1190  * device i.e. per-cpu data
1191  *
1192  * @pr: the ACPI processor
1193  * @dev : the cpuidle device
1194  */
1195 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1196                                             struct cpuidle_device *dev)
1197 {
1198         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1199                 return -EINVAL;
1200
1201         dev->cpu = pr->id;
1202         if (pr->flags.has_lpi)
1203                 return acpi_processor_ffh_lpi_probe(pr->id);
1204
1205         return acpi_processor_setup_cpuidle_cx(pr, dev);
1206 }
1207
1208 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1209 {
1210         int ret;
1211
1212         ret = acpi_processor_get_lpi_info(pr);
1213         if (ret)
1214                 ret = acpi_processor_get_cstate_info(pr);
1215
1216         return ret;
1217 }
1218
1219 int acpi_processor_hotplug(struct acpi_processor *pr)
1220 {
1221         int ret = 0;
1222         struct cpuidle_device *dev;
1223
1224         if (disabled_by_idle_boot_param())
1225                 return 0;
1226
1227         if (!pr->flags.power_setup_done)
1228                 return -ENODEV;
1229
1230         dev = per_cpu(acpi_cpuidle_device, pr->id);
1231         cpuidle_pause_and_lock();
1232         cpuidle_disable_device(dev);
1233         ret = acpi_processor_get_power_info(pr);
1234         if (!ret && pr->flags.power) {
1235                 acpi_processor_setup_cpuidle_dev(pr, dev);
1236                 ret = cpuidle_enable_device(dev);
1237         }
1238         cpuidle_resume_and_unlock();
1239
1240         return ret;
1241 }
1242
1243 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1244 {
1245         int cpu;
1246         struct acpi_processor *_pr;
1247         struct cpuidle_device *dev;
1248
1249         if (disabled_by_idle_boot_param())
1250                 return 0;
1251
1252         if (!pr->flags.power_setup_done)
1253                 return -ENODEV;
1254
1255         /*
1256          * FIXME:  Design the ACPI notification to make it once per
1257          * system instead of once per-cpu.  This condition is a hack
1258          * to make the code that updates C-States be called once.
1259          */
1260
1261         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1262
1263                 /* Protect against cpu-hotplug */
1264                 get_online_cpus();
1265                 cpuidle_pause_and_lock();
1266
1267                 /* Disable all cpuidle devices */
1268                 for_each_online_cpu(cpu) {
1269                         _pr = per_cpu(processors, cpu);
1270                         if (!_pr || !_pr->flags.power_setup_done)
1271                                 continue;
1272                         dev = per_cpu(acpi_cpuidle_device, cpu);
1273                         cpuidle_disable_device(dev);
1274                 }
1275
1276                 /* Populate Updated C-state information */
1277                 acpi_processor_get_power_info(pr);
1278                 acpi_processor_setup_cpuidle_states(pr);
1279
1280                 /* Enable all cpuidle devices */
1281                 for_each_online_cpu(cpu) {
1282                         _pr = per_cpu(processors, cpu);
1283                         if (!_pr || !_pr->flags.power_setup_done)
1284                                 continue;
1285                         acpi_processor_get_power_info(_pr);
1286                         if (_pr->flags.power) {
1287                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1288                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1289                                 cpuidle_enable_device(dev);
1290                         }
1291                 }
1292                 cpuidle_resume_and_unlock();
1293                 put_online_cpus();
1294         }
1295
1296         return 0;
1297 }
1298
1299 static int acpi_processor_registered;
1300
1301 int acpi_processor_power_init(struct acpi_processor *pr)
1302 {
1303         int retval;
1304         struct cpuidle_device *dev;
1305
1306         if (disabled_by_idle_boot_param())
1307                 return 0;
1308
1309         acpi_processor_cstate_first_run_checks();
1310
1311         if (!acpi_processor_get_power_info(pr))
1312                 pr->flags.power_setup_done = 1;
1313
1314         /*
1315          * Install the idle handler if processor power management is supported.
1316          * Note that we use previously set idle handler will be used on
1317          * platforms that only support C1.
1318          */
1319         if (pr->flags.power) {
1320                 /* Register acpi_idle_driver if not already registered */
1321                 if (!acpi_processor_registered) {
1322                         acpi_processor_setup_cpuidle_states(pr);
1323                         retval = cpuidle_register_driver(&acpi_idle_driver);
1324                         if (retval)
1325                                 return retval;
1326                         pr_debug("%s registered with cpuidle\n",
1327                                  acpi_idle_driver.name);
1328                 }
1329
1330                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1331                 if (!dev)
1332                         return -ENOMEM;
1333                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1334
1335                 acpi_processor_setup_cpuidle_dev(pr, dev);
1336
1337                 /* Register per-cpu cpuidle_device. Cpuidle driver
1338                  * must already be registered before registering device
1339                  */
1340                 retval = cpuidle_register_device(dev);
1341                 if (retval) {
1342                         if (acpi_processor_registered == 0)
1343                                 cpuidle_unregister_driver(&acpi_idle_driver);
1344                         return retval;
1345                 }
1346                 acpi_processor_registered++;
1347         }
1348         return 0;
1349 }
1350
1351 int acpi_processor_power_exit(struct acpi_processor *pr)
1352 {
1353         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1354
1355         if (disabled_by_idle_boot_param())
1356                 return 0;
1357
1358         if (pr->flags.power) {
1359                 cpuidle_unregister_device(dev);
1360                 acpi_processor_registered--;
1361                 if (acpi_processor_registered == 0)
1362                         cpuidle_unregister_driver(&acpi_idle_driver);
1363         }
1364
1365         pr->flags.power_setup_done = 0;
1366         return 0;
1367 }