Merge tag 'mips_fixes_5.1_1' into mips-next
[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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25  */
26 #define pr_fmt(fmt) "ACPI: " fmt
27
28 #include <linux/module.h>
29 #include <linux/acpi.h>
30 #include <linux/dmi.h>
31 #include <linux/sched.h>       /* need_resched() */
32 #include <linux/tick.h>
33 #include <linux/cpuidle.h>
34 #include <linux/cpu.h>
35 #include <acpi/processor.h>
36
37 /*
38  * Include the apic definitions for x86 to have the APIC timer related defines
39  * available also for UP (on SMP it gets magically included via linux/smp.h).
40  * asm/acpi.h is not an option, as it would require more include magic. Also
41  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
42  */
43 #ifdef CONFIG_X86
44 #include <asm/apic.h>
45 #endif
46
47 #define ACPI_PROCESSOR_CLASS            "processor"
48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
49 ACPI_MODULE_NAME("processor_idle");
50
51 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
52
53 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
54 module_param(max_cstate, uint, 0000);
55 static unsigned int nocst __read_mostly;
56 module_param(nocst, uint, 0000);
57 static int bm_check_disable __read_mostly;
58 module_param(bm_check_disable, uint, 0000);
59
60 static unsigned int latency_factor __read_mostly = 2;
61 module_param(latency_factor, uint, 0644);
62
63 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
64
65 struct cpuidle_driver acpi_idle_driver = {
66         .name =         "acpi_idle",
67         .owner =        THIS_MODULE,
68 };
69
70 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
71 static
72 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
73
74 static int disabled_by_idle_boot_param(void)
75 {
76         return boot_option_idle_override == IDLE_POLL ||
77                 boot_option_idle_override == IDLE_HALT;
78 }
79
80 /*
81  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
82  * For now disable this. Probably a bug somewhere else.
83  *
84  * To skip this limit, boot/load with a large max_cstate limit.
85  */
86 static int set_max_cstate(const struct dmi_system_id *id)
87 {
88         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
89                 return 0;
90
91         pr_notice("%s detected - limiting to C%ld max_cstate."
92                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
93                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
94
95         max_cstate = (long)id->driver_data;
96
97         return 0;
98 }
99
100 static const struct dmi_system_id processor_power_dmi_table[] = {
101         { set_max_cstate, "Clevo 5600D", {
102           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
103           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
104          (void *)2},
105         { set_max_cstate, "Pavilion zv5000", {
106           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
107           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
108          (void *)1},
109         { set_max_cstate, "Asus L8400B", {
110           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
111           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
112          (void *)1},
113         {},
114 };
115
116
117 /*
118  * Callers should disable interrupts before the call and enable
119  * interrupts after return.
120  */
121 static void __cpuidle acpi_safe_halt(void)
122 {
123         if (!tif_need_resched()) {
124                 safe_halt();
125                 local_irq_disable();
126         }
127 }
128
129 #ifdef ARCH_APICTIMER_STOPS_ON_C3
130
131 /*
132  * Some BIOS implementations switch to C3 in the published C2 state.
133  * This seems to be a common problem on AMD boxen, but other vendors
134  * are affected too. We pick the most conservative approach: we assume
135  * that the local APIC stops in both C2 and C3.
136  */
137 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
138                                    struct acpi_processor_cx *cx)
139 {
140         struct acpi_processor_power *pwr = &pr->power;
141         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
142
143         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
144                 return;
145
146         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
147                 type = ACPI_STATE_C1;
148
149         /*
150          * Check, if one of the previous states already marked the lapic
151          * unstable
152          */
153         if (pwr->timer_broadcast_on_state < state)
154                 return;
155
156         if (cx->type >= type)
157                 pr->power.timer_broadcast_on_state = state;
158 }
159
160 static void __lapic_timer_propagate_broadcast(void *arg)
161 {
162         struct acpi_processor *pr = (struct acpi_processor *) arg;
163
164         if (pr->power.timer_broadcast_on_state < INT_MAX)
165                 tick_broadcast_enable();
166         else
167                 tick_broadcast_disable();
168 }
169
170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
171 {
172         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
173                                  (void *)pr, 1);
174 }
175
176 /* Power(C) State timer broadcast control */
177 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
178                                        struct acpi_processor_cx *cx,
179                                        int broadcast)
180 {
181         int state = cx - pr->power.states;
182
183         if (state >= pr->power.timer_broadcast_on_state) {
184                 if (broadcast)
185                         tick_broadcast_enter();
186                 else
187                         tick_broadcast_exit();
188         }
189 }
190
191 #else
192
193 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
194                                    struct acpi_processor_cx *cstate) { }
195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
196 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
197                                        struct acpi_processor_cx *cx,
198                                        int broadcast)
199 {
200 }
201
202 #endif
203
204 #if defined(CONFIG_X86)
205 static void tsc_check_state(int state)
206 {
207         switch (boot_cpu_data.x86_vendor) {
208         case X86_VENDOR_HYGON:
209         case X86_VENDOR_AMD:
210         case X86_VENDOR_INTEL:
211         case X86_VENDOR_CENTAUR:
212                 /*
213                  * AMD Fam10h TSC will tick in all
214                  * C/P/S0/S1 states when this bit is set.
215                  */
216                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
217                         return;
218
219                 /*FALL THROUGH*/
220         default:
221                 /* TSC could halt in idle, so notify users */
222                 if (state > ACPI_STATE_C1)
223                         mark_tsc_unstable("TSC halts in idle");
224         }
225 }
226 #else
227 static void tsc_check_state(int state) { return; }
228 #endif
229
230 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
231 {
232
233         if (!pr->pblk)
234                 return -ENODEV;
235
236         /* if info is obtained from pblk/fadt, type equals state */
237         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
238         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
239
240 #ifndef CONFIG_HOTPLUG_CPU
241         /*
242          * Check for P_LVL2_UP flag before entering C2 and above on
243          * an SMP system.
244          */
245         if ((num_online_cpus() > 1) &&
246             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
247                 return -ENODEV;
248 #endif
249
250         /* determine C2 and C3 address from pblk */
251         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
252         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
253
254         /* determine latencies from FADT */
255         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
256         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
257
258         /*
259          * FADT specified C2 latency must be less than or equal to
260          * 100 microseconds.
261          */
262         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
263                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
264                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
265                 /* invalidate C2 */
266                 pr->power.states[ACPI_STATE_C2].address = 0;
267         }
268
269         /*
270          * FADT supplied C3 latency must be less than or equal to
271          * 1000 microseconds.
272          */
273         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
274                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
275                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
276                 /* invalidate C3 */
277                 pr->power.states[ACPI_STATE_C3].address = 0;
278         }
279
280         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
281                           "lvl2[0x%08x] lvl3[0x%08x]\n",
282                           pr->power.states[ACPI_STATE_C2].address,
283                           pr->power.states[ACPI_STATE_C3].address));
284
285         snprintf(pr->power.states[ACPI_STATE_C2].desc,
286                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
287                          pr->power.states[ACPI_STATE_C2].address);
288         snprintf(pr->power.states[ACPI_STATE_C3].desc,
289                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
290                          pr->power.states[ACPI_STATE_C3].address);
291
292         return 0;
293 }
294
295 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
296 {
297         if (!pr->power.states[ACPI_STATE_C1].valid) {
298                 /* set the first C-State to C1 */
299                 /* all processors need to support C1 */
300                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
301                 pr->power.states[ACPI_STATE_C1].valid = 1;
302                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
303
304                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
305                          ACPI_CX_DESC_LEN, "ACPI HLT");
306         }
307         /* the C0 state only exists as a filler in our array */
308         pr->power.states[ACPI_STATE_C0].valid = 1;
309         return 0;
310 }
311
312 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
313 {
314         acpi_status status;
315         u64 count;
316         int current_count;
317         int i, ret = 0;
318         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
319         union acpi_object *cst;
320
321         if (nocst)
322                 return -ENODEV;
323
324         current_count = 0;
325
326         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
327         if (ACPI_FAILURE(status)) {
328                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
329                 return -ENODEV;
330         }
331
332         cst = buffer.pointer;
333
334         /* There must be at least 2 elements */
335         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
336                 pr_err("not enough elements in _CST\n");
337                 ret = -EFAULT;
338                 goto end;
339         }
340
341         count = cst->package.elements[0].integer.value;
342
343         /* Validate number of power states. */
344         if (count < 1 || count != cst->package.count - 1) {
345                 pr_err("count given by _CST is not valid\n");
346                 ret = -EFAULT;
347                 goto end;
348         }
349
350         /* Tell driver that at least _CST is supported. */
351         pr->flags.has_cst = 1;
352
353         for (i = 1; i <= count; i++) {
354                 union acpi_object *element;
355                 union acpi_object *obj;
356                 struct acpi_power_register *reg;
357                 struct acpi_processor_cx cx;
358
359                 memset(&cx, 0, sizeof(cx));
360
361                 element = &(cst->package.elements[i]);
362                 if (element->type != ACPI_TYPE_PACKAGE)
363                         continue;
364
365                 if (element->package.count != 4)
366                         continue;
367
368                 obj = &(element->package.elements[0]);
369
370                 if (obj->type != ACPI_TYPE_BUFFER)
371                         continue;
372
373                 reg = (struct acpi_power_register *)obj->buffer.pointer;
374
375                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
376                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
377                         continue;
378
379                 /* There should be an easy way to extract an integer... */
380                 obj = &(element->package.elements[1]);
381                 if (obj->type != ACPI_TYPE_INTEGER)
382                         continue;
383
384                 cx.type = obj->integer.value;
385                 /*
386                  * Some buggy BIOSes won't list C1 in _CST -
387                  * Let acpi_processor_get_power_info_default() handle them later
388                  */
389                 if (i == 1 && cx.type != ACPI_STATE_C1)
390                         current_count++;
391
392                 cx.address = reg->address;
393                 cx.index = current_count + 1;
394
395                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
396                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
397                         if (acpi_processor_ffh_cstate_probe
398                                         (pr->id, &cx, reg) == 0) {
399                                 cx.entry_method = ACPI_CSTATE_FFH;
400                         } else if (cx.type == ACPI_STATE_C1) {
401                                 /*
402                                  * C1 is a special case where FIXED_HARDWARE
403                                  * can be handled in non-MWAIT way as well.
404                                  * In that case, save this _CST entry info.
405                                  * Otherwise, ignore this info and continue.
406                                  */
407                                 cx.entry_method = ACPI_CSTATE_HALT;
408                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
409                         } else {
410                                 continue;
411                         }
412                         if (cx.type == ACPI_STATE_C1 &&
413                             (boot_option_idle_override == IDLE_NOMWAIT)) {
414                                 /*
415                                  * In most cases the C1 space_id obtained from
416                                  * _CST object is FIXED_HARDWARE access mode.
417                                  * But when the option of idle=halt is added,
418                                  * the entry_method type should be changed from
419                                  * CSTATE_FFH to CSTATE_HALT.
420                                  * When the option of idle=nomwait is added,
421                                  * the C1 entry_method type should be
422                                  * CSTATE_HALT.
423                                  */
424                                 cx.entry_method = ACPI_CSTATE_HALT;
425                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
426                         }
427                 } else {
428                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
429                                  cx.address);
430                 }
431
432                 if (cx.type == ACPI_STATE_C1) {
433                         cx.valid = 1;
434                 }
435
436                 obj = &(element->package.elements[2]);
437                 if (obj->type != ACPI_TYPE_INTEGER)
438                         continue;
439
440                 cx.latency = obj->integer.value;
441
442                 obj = &(element->package.elements[3]);
443                 if (obj->type != ACPI_TYPE_INTEGER)
444                         continue;
445
446                 current_count++;
447                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
448
449                 /*
450                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
451                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
452                  */
453                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
454                         pr_warn("Limiting number of power states to max (%d)\n",
455                                 ACPI_PROCESSOR_MAX_POWER);
456                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
457                         break;
458                 }
459         }
460
461         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
462                           current_count));
463
464         /* Validate number of power states discovered */
465         if (current_count < 2)
466                 ret = -EFAULT;
467
468       end:
469         kfree(buffer.pointer);
470
471         return ret;
472 }
473
474 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
475                                            struct acpi_processor_cx *cx)
476 {
477         static int bm_check_flag = -1;
478         static int bm_control_flag = -1;
479
480
481         if (!cx->address)
482                 return;
483
484         /*
485          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
486          * DMA transfers are used by any ISA device to avoid livelock.
487          * Note that we could disable Type-F DMA (as recommended by
488          * the erratum), but this is known to disrupt certain ISA
489          * devices thus we take the conservative approach.
490          */
491         else if (errata.piix4.fdma) {
492                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
493                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
494                 return;
495         }
496
497         /* All the logic here assumes flags.bm_check is same across all CPUs */
498         if (bm_check_flag == -1) {
499                 /* Determine whether bm_check is needed based on CPU  */
500                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
501                 bm_check_flag = pr->flags.bm_check;
502                 bm_control_flag = pr->flags.bm_control;
503         } else {
504                 pr->flags.bm_check = bm_check_flag;
505                 pr->flags.bm_control = bm_control_flag;
506         }
507
508         if (pr->flags.bm_check) {
509                 if (!pr->flags.bm_control) {
510                         if (pr->flags.has_cst != 1) {
511                                 /* bus mastering control is necessary */
512                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
513                                         "C3 support requires BM control\n"));
514                                 return;
515                         } else {
516                                 /* Here we enter C3 without bus mastering */
517                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
518                                         "C3 support without BM control\n"));
519                         }
520                 }
521         } else {
522                 /*
523                  * WBINVD should be set in fadt, for C3 state to be
524                  * supported on when bm_check is not required.
525                  */
526                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
527                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
528                                           "Cache invalidation should work properly"
529                                           " for C3 to be enabled on SMP systems\n"));
530                         return;
531                 }
532         }
533
534         /*
535          * Otherwise we've met all of our C3 requirements.
536          * Normalize the C3 latency to expidite policy.  Enable
537          * checking of bus mastering status (bm_check) so we can
538          * use this in our C3 policy
539          */
540         cx->valid = 1;
541
542         /*
543          * On older chipsets, BM_RLD needs to be set
544          * in order for Bus Master activity to wake the
545          * system from C3.  Newer chipsets handle DMA
546          * during C3 automatically and BM_RLD is a NOP.
547          * In either case, the proper way to
548          * handle BM_RLD is to set it and leave it set.
549          */
550         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
551
552         return;
553 }
554
555 static int acpi_processor_power_verify(struct acpi_processor *pr)
556 {
557         unsigned int i;
558         unsigned int working = 0;
559
560         pr->power.timer_broadcast_on_state = INT_MAX;
561
562         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
563                 struct acpi_processor_cx *cx = &pr->power.states[i];
564
565                 switch (cx->type) {
566                 case ACPI_STATE_C1:
567                         cx->valid = 1;
568                         break;
569
570                 case ACPI_STATE_C2:
571                         if (!cx->address)
572                                 break;
573                         cx->valid = 1;
574                         break;
575
576                 case ACPI_STATE_C3:
577                         acpi_processor_power_verify_c3(pr, cx);
578                         break;
579                 }
580                 if (!cx->valid)
581                         continue;
582
583                 lapic_timer_check_state(i, pr, cx);
584                 tsc_check_state(cx->type);
585                 working++;
586         }
587
588         lapic_timer_propagate_broadcast(pr);
589
590         return (working);
591 }
592
593 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
594 {
595         unsigned int i;
596         int result;
597
598
599         /* NOTE: the idle thread may not be running while calling
600          * this function */
601
602         /* Zero initialize all the C-states info. */
603         memset(pr->power.states, 0, sizeof(pr->power.states));
604
605         result = acpi_processor_get_power_info_cst(pr);
606         if (result == -ENODEV)
607                 result = acpi_processor_get_power_info_fadt(pr);
608
609         if (result)
610                 return result;
611
612         acpi_processor_get_power_info_default(pr);
613
614         pr->power.count = acpi_processor_power_verify(pr);
615
616         /*
617          * if one state of type C2 or C3 is available, mark this
618          * CPU as being "idle manageable"
619          */
620         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
621                 if (pr->power.states[i].valid) {
622                         pr->power.count = i;
623                         if (pr->power.states[i].type >= ACPI_STATE_C2)
624                                 pr->flags.power = 1;
625                 }
626         }
627
628         return 0;
629 }
630
631 /**
632  * acpi_idle_bm_check - checks if bus master activity was detected
633  */
634 static int acpi_idle_bm_check(void)
635 {
636         u32 bm_status = 0;
637
638         if (bm_check_disable)
639                 return 0;
640
641         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
642         if (bm_status)
643                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
644         /*
645          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
646          * the true state of bus mastering activity; forcing us to
647          * manually check the BMIDEA bit of each IDE channel.
648          */
649         else if (errata.piix4.bmisx) {
650                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
651                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
652                         bm_status = 1;
653         }
654         return bm_status;
655 }
656
657 /**
658  * acpi_idle_do_entry - enter idle state using the appropriate method
659  * @cx: cstate data
660  *
661  * Caller disables interrupt before call and enables interrupt after return.
662  */
663 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
664 {
665         if (cx->entry_method == ACPI_CSTATE_FFH) {
666                 /* Call into architectural FFH based C-state */
667                 acpi_processor_ffh_cstate_enter(cx);
668         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
669                 acpi_safe_halt();
670         } else {
671                 /* IO port based C-state */
672                 inb(cx->address);
673                 /* Dummy wait op - must do something useless after P_LVL2 read
674                    because chipsets cannot guarantee that STPCLK# signal
675                    gets asserted in time to freeze execution properly. */
676                 inl(acpi_gbl_FADT.xpm_timer_block.address);
677         }
678 }
679
680 /**
681  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
682  * @dev: the target CPU
683  * @index: the index of suggested state
684  */
685 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
686 {
687         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
688
689         ACPI_FLUSH_CPU_CACHE();
690
691         while (1) {
692
693                 if (cx->entry_method == ACPI_CSTATE_HALT)
694                         safe_halt();
695                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
696                         inb(cx->address);
697                         /* See comment in acpi_idle_do_entry() */
698                         inl(acpi_gbl_FADT.xpm_timer_block.address);
699                 } else
700                         return -ENODEV;
701         }
702
703         /* Never reached */
704         return 0;
705 }
706
707 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
708 {
709         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
710                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
711 }
712
713 static int c3_cpu_count;
714 static DEFINE_RAW_SPINLOCK(c3_lock);
715
716 /**
717  * acpi_idle_enter_bm - enters C3 with proper BM handling
718  * @pr: Target processor
719  * @cx: Target state context
720  * @timer_bc: Whether or not to change timer mode to broadcast
721  */
722 static void acpi_idle_enter_bm(struct acpi_processor *pr,
723                                struct acpi_processor_cx *cx, bool timer_bc)
724 {
725         acpi_unlazy_tlb(smp_processor_id());
726
727         /*
728          * Must be done before busmaster disable as we might need to
729          * access HPET !
730          */
731         if (timer_bc)
732                 lapic_timer_state_broadcast(pr, cx, 1);
733
734         /*
735          * disable bus master
736          * bm_check implies we need ARB_DIS
737          * bm_control implies whether we can do ARB_DIS
738          *
739          * That leaves a case where bm_check is set and bm_control is
740          * not set. In that case we cannot do much, we enter C3
741          * without doing anything.
742          */
743         if (pr->flags.bm_control) {
744                 raw_spin_lock(&c3_lock);
745                 c3_cpu_count++;
746                 /* Disable bus master arbitration when all CPUs are in C3 */
747                 if (c3_cpu_count == num_online_cpus())
748                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
749                 raw_spin_unlock(&c3_lock);
750         }
751
752         acpi_idle_do_entry(cx);
753
754         /* Re-enable bus master arbitration */
755         if (pr->flags.bm_control) {
756                 raw_spin_lock(&c3_lock);
757                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
758                 c3_cpu_count--;
759                 raw_spin_unlock(&c3_lock);
760         }
761
762         if (timer_bc)
763                 lapic_timer_state_broadcast(pr, cx, 0);
764 }
765
766 static int acpi_idle_enter(struct cpuidle_device *dev,
767                            struct cpuidle_driver *drv, int index)
768 {
769         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
770         struct acpi_processor *pr;
771
772         pr = __this_cpu_read(processors);
773         if (unlikely(!pr))
774                 return -EINVAL;
775
776         if (cx->type != ACPI_STATE_C1) {
777                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
778                         index = ACPI_IDLE_STATE_START;
779                         cx = per_cpu(acpi_cstate[index], dev->cpu);
780                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
781                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
782                                 acpi_idle_enter_bm(pr, cx, true);
783                                 return index;
784                         } else if (drv->safe_state_index >= 0) {
785                                 index = drv->safe_state_index;
786                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
787                         } else {
788                                 acpi_safe_halt();
789                                 return -EBUSY;
790                         }
791                 }
792         }
793
794         lapic_timer_state_broadcast(pr, cx, 1);
795
796         if (cx->type == ACPI_STATE_C3)
797                 ACPI_FLUSH_CPU_CACHE();
798
799         acpi_idle_do_entry(cx);
800
801         lapic_timer_state_broadcast(pr, cx, 0);
802
803         return index;
804 }
805
806 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
807                                    struct cpuidle_driver *drv, int index)
808 {
809         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
810
811         if (cx->type == ACPI_STATE_C3) {
812                 struct acpi_processor *pr = __this_cpu_read(processors);
813
814                 if (unlikely(!pr))
815                         return;
816
817                 if (pr->flags.bm_check) {
818                         acpi_idle_enter_bm(pr, cx, false);
819                         return;
820                 } else {
821                         ACPI_FLUSH_CPU_CACHE();
822                 }
823         }
824         acpi_idle_do_entry(cx);
825 }
826
827 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
828                                            struct cpuidle_device *dev)
829 {
830         int i, count = ACPI_IDLE_STATE_START;
831         struct acpi_processor_cx *cx;
832
833         if (max_cstate == 0)
834                 max_cstate = 1;
835
836         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
837                 cx = &pr->power.states[i];
838
839                 if (!cx->valid)
840                         continue;
841
842                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
843
844                 count++;
845                 if (count == CPUIDLE_STATE_MAX)
846                         break;
847         }
848
849         if (!count)
850                 return -EINVAL;
851
852         return 0;
853 }
854
855 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
856 {
857         int i, count;
858         struct acpi_processor_cx *cx;
859         struct cpuidle_state *state;
860         struct cpuidle_driver *drv = &acpi_idle_driver;
861
862         if (max_cstate == 0)
863                 max_cstate = 1;
864
865         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
866                 cpuidle_poll_state_init(drv);
867                 count = 1;
868         } else {
869                 count = 0;
870         }
871
872         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
873                 cx = &pr->power.states[i];
874
875                 if (!cx->valid)
876                         continue;
877
878                 state = &drv->states[count];
879                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
880                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
881                 state->exit_latency = cx->latency;
882                 state->target_residency = cx->latency * latency_factor;
883                 state->enter = acpi_idle_enter;
884
885                 state->flags = 0;
886                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
887                         state->enter_dead = acpi_idle_play_dead;
888                         drv->safe_state_index = count;
889                 }
890                 /*
891                  * Halt-induced C1 is not good for ->enter_s2idle, because it
892                  * re-enables interrupts on exit.  Moreover, C1 is generally not
893                  * particularly interesting from the suspend-to-idle angle, so
894                  * avoid C1 and the situations in which we may need to fall back
895                  * to it altogether.
896                  */
897                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
898                         state->enter_s2idle = acpi_idle_enter_s2idle;
899
900                 count++;
901                 if (count == CPUIDLE_STATE_MAX)
902                         break;
903         }
904
905         drv->state_count = count;
906
907         if (!count)
908                 return -EINVAL;
909
910         return 0;
911 }
912
913 static inline void acpi_processor_cstate_first_run_checks(void)
914 {
915         acpi_status status;
916         static int first_run;
917
918         if (first_run)
919                 return;
920         dmi_check_system(processor_power_dmi_table);
921         max_cstate = acpi_processor_cstate_check(max_cstate);
922         if (max_cstate < ACPI_C_STATES_MAX)
923                 pr_notice("ACPI: processor limited to max C-state %d\n",
924                           max_cstate);
925         first_run++;
926
927         if (acpi_gbl_FADT.cst_control && !nocst) {
928                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
929                                             acpi_gbl_FADT.cst_control, 8);
930                 if (ACPI_FAILURE(status))
931                         ACPI_EXCEPTION((AE_INFO, status,
932                                         "Notifying BIOS of _CST ability failed"));
933         }
934 }
935 #else
936
937 static inline int disabled_by_idle_boot_param(void) { return 0; }
938 static inline void acpi_processor_cstate_first_run_checks(void) { }
939 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
940 {
941         return -ENODEV;
942 }
943
944 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
945                                            struct cpuidle_device *dev)
946 {
947         return -EINVAL;
948 }
949
950 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
951 {
952         return -EINVAL;
953 }
954
955 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
956
957 struct acpi_lpi_states_array {
958         unsigned int size;
959         unsigned int composite_states_size;
960         struct acpi_lpi_state *entries;
961         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
962 };
963
964 static int obj_get_integer(union acpi_object *obj, u32 *value)
965 {
966         if (obj->type != ACPI_TYPE_INTEGER)
967                 return -EINVAL;
968
969         *value = obj->integer.value;
970         return 0;
971 }
972
973 static int acpi_processor_evaluate_lpi(acpi_handle handle,
974                                        struct acpi_lpi_states_array *info)
975 {
976         acpi_status status;
977         int ret = 0;
978         int pkg_count, state_idx = 1, loop;
979         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
980         union acpi_object *lpi_data;
981         struct acpi_lpi_state *lpi_state;
982
983         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
984         if (ACPI_FAILURE(status)) {
985                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
986                 return -ENODEV;
987         }
988
989         lpi_data = buffer.pointer;
990
991         /* There must be at least 4 elements = 3 elements + 1 package */
992         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
993             lpi_data->package.count < 4) {
994                 pr_debug("not enough elements in _LPI\n");
995                 ret = -ENODATA;
996                 goto end;
997         }
998
999         pkg_count = lpi_data->package.elements[2].integer.value;
1000
1001         /* Validate number of power states. */
1002         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
1003                 pr_debug("count given by _LPI is not valid\n");
1004                 ret = -ENODATA;
1005                 goto end;
1006         }
1007
1008         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1009         if (!lpi_state) {
1010                 ret = -ENOMEM;
1011                 goto end;
1012         }
1013
1014         info->size = pkg_count;
1015         info->entries = lpi_state;
1016
1017         /* LPI States start at index 3 */
1018         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1019                 union acpi_object *element, *pkg_elem, *obj;
1020
1021                 element = &lpi_data->package.elements[loop];
1022                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1023                         continue;
1024
1025                 pkg_elem = element->package.elements;
1026
1027                 obj = pkg_elem + 6;
1028                 if (obj->type == ACPI_TYPE_BUFFER) {
1029                         struct acpi_power_register *reg;
1030
1031                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1032                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1033                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1034                                 continue;
1035
1036                         lpi_state->address = reg->address;
1037                         lpi_state->entry_method =
1038                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1039                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1040                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1041                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1042                         lpi_state->address = obj->integer.value;
1043                 } else {
1044                         continue;
1045                 }
1046
1047                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1048
1049                 obj = pkg_elem + 9;
1050                 if (obj->type == ACPI_TYPE_STRING)
1051                         strlcpy(lpi_state->desc, obj->string.pointer,
1052                                 ACPI_CX_DESC_LEN);
1053
1054                 lpi_state->index = state_idx;
1055                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1056                         pr_debug("No min. residency found, assuming 10 us\n");
1057                         lpi_state->min_residency = 10;
1058                 }
1059
1060                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1061                         pr_debug("No wakeup residency found, assuming 10 us\n");
1062                         lpi_state->wake_latency = 10;
1063                 }
1064
1065                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1066                         lpi_state->flags = 0;
1067
1068                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1069                         lpi_state->arch_flags = 0;
1070
1071                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1072                         lpi_state->res_cnt_freq = 1;
1073
1074                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1075                         lpi_state->enable_parent_state = 0;
1076         }
1077
1078         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1079 end:
1080         kfree(buffer.pointer);
1081         return ret;
1082 }
1083
1084 /*
1085  * flat_state_cnt - the number of composite LPI states after the process of flattening
1086  */
1087 static int flat_state_cnt;
1088
1089 /**
1090  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1091  *
1092  * @local: local LPI state
1093  * @parent: parent LPI state
1094  * @result: composite LPI state
1095  */
1096 static bool combine_lpi_states(struct acpi_lpi_state *local,
1097                                struct acpi_lpi_state *parent,
1098                                struct acpi_lpi_state *result)
1099 {
1100         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1101                 if (!parent->address) /* 0 means autopromotable */
1102                         return false;
1103                 result->address = local->address + parent->address;
1104         } else {
1105                 result->address = parent->address;
1106         }
1107
1108         result->min_residency = max(local->min_residency, parent->min_residency);
1109         result->wake_latency = local->wake_latency + parent->wake_latency;
1110         result->enable_parent_state = parent->enable_parent_state;
1111         result->entry_method = local->entry_method;
1112
1113         result->flags = parent->flags;
1114         result->arch_flags = parent->arch_flags;
1115         result->index = parent->index;
1116
1117         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1118         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1119         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1120         return true;
1121 }
1122
1123 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1124
1125 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1126                                   struct acpi_lpi_state *t)
1127 {
1128         curr_level->composite_states[curr_level->composite_states_size++] = t;
1129 }
1130
1131 static int flatten_lpi_states(struct acpi_processor *pr,
1132                               struct acpi_lpi_states_array *curr_level,
1133                               struct acpi_lpi_states_array *prev_level)
1134 {
1135         int i, j, state_count = curr_level->size;
1136         struct acpi_lpi_state *p, *t = curr_level->entries;
1137
1138         curr_level->composite_states_size = 0;
1139         for (j = 0; j < state_count; j++, t++) {
1140                 struct acpi_lpi_state *flpi;
1141
1142                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1143                         continue;
1144
1145                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1146                         pr_warn("Limiting number of LPI states to max (%d)\n",
1147                                 ACPI_PROCESSOR_MAX_POWER);
1148                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1149                         break;
1150                 }
1151
1152                 flpi = &pr->power.lpi_states[flat_state_cnt];
1153
1154                 if (!prev_level) { /* leaf/processor node */
1155                         memcpy(flpi, t, sizeof(*t));
1156                         stash_composite_state(curr_level, flpi);
1157                         flat_state_cnt++;
1158                         continue;
1159                 }
1160
1161                 for (i = 0; i < prev_level->composite_states_size; i++) {
1162                         p = prev_level->composite_states[i];
1163                         if (t->index <= p->enable_parent_state &&
1164                             combine_lpi_states(p, t, flpi)) {
1165                                 stash_composite_state(curr_level, flpi);
1166                                 flat_state_cnt++;
1167                                 flpi++;
1168                         }
1169                 }
1170         }
1171
1172         kfree(curr_level->entries);
1173         return 0;
1174 }
1175
1176 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1177 {
1178         int ret, i;
1179         acpi_status status;
1180         acpi_handle handle = pr->handle, pr_ahandle;
1181         struct acpi_device *d = NULL;
1182         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1183
1184         if (!osc_pc_lpi_support_confirmed)
1185                 return -EOPNOTSUPP;
1186
1187         if (!acpi_has_method(handle, "_LPI"))
1188                 return -EINVAL;
1189
1190         flat_state_cnt = 0;
1191         prev = &info[0];
1192         curr = &info[1];
1193         handle = pr->handle;
1194         ret = acpi_processor_evaluate_lpi(handle, prev);
1195         if (ret)
1196                 return ret;
1197         flatten_lpi_states(pr, prev, NULL);
1198
1199         status = acpi_get_parent(handle, &pr_ahandle);
1200         while (ACPI_SUCCESS(status)) {
1201                 acpi_bus_get_device(pr_ahandle, &d);
1202                 handle = pr_ahandle;
1203
1204                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1205                         break;
1206
1207                 /* can be optional ? */
1208                 if (!acpi_has_method(handle, "_LPI"))
1209                         break;
1210
1211                 ret = acpi_processor_evaluate_lpi(handle, curr);
1212                 if (ret)
1213                         break;
1214
1215                 /* flatten all the LPI states in this level of hierarchy */
1216                 flatten_lpi_states(pr, curr, prev);
1217
1218                 tmp = prev, prev = curr, curr = tmp;
1219
1220                 status = acpi_get_parent(handle, &pr_ahandle);
1221         }
1222
1223         pr->power.count = flat_state_cnt;
1224         /* reset the index after flattening */
1225         for (i = 0; i < pr->power.count; i++)
1226                 pr->power.lpi_states[i].index = i;
1227
1228         /* Tell driver that _LPI is supported. */
1229         pr->flags.has_lpi = 1;
1230         pr->flags.power = 1;
1231
1232         return 0;
1233 }
1234
1235 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1236 {
1237         return -ENODEV;
1238 }
1239
1240 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1241 {
1242         return -ENODEV;
1243 }
1244
1245 /**
1246  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1247  * @dev: the target CPU
1248  * @drv: cpuidle driver containing cpuidle state info
1249  * @index: index of target state
1250  *
1251  * Return: 0 for success or negative value for error
1252  */
1253 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1254                                struct cpuidle_driver *drv, int index)
1255 {
1256         struct acpi_processor *pr;
1257         struct acpi_lpi_state *lpi;
1258
1259         pr = __this_cpu_read(processors);
1260
1261         if (unlikely(!pr))
1262                 return -EINVAL;
1263
1264         lpi = &pr->power.lpi_states[index];
1265         if (lpi->entry_method == ACPI_CSTATE_FFH)
1266                 return acpi_processor_ffh_lpi_enter(lpi);
1267
1268         return -EINVAL;
1269 }
1270
1271 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1272 {
1273         int i;
1274         struct acpi_lpi_state *lpi;
1275         struct cpuidle_state *state;
1276         struct cpuidle_driver *drv = &acpi_idle_driver;
1277
1278         if (!pr->flags.has_lpi)
1279                 return -EOPNOTSUPP;
1280
1281         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1282                 lpi = &pr->power.lpi_states[i];
1283
1284                 state = &drv->states[i];
1285                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1286                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1287                 state->exit_latency = lpi->wake_latency;
1288                 state->target_residency = lpi->min_residency;
1289                 if (lpi->arch_flags)
1290                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1291                 state->enter = acpi_idle_lpi_enter;
1292                 drv->safe_state_index = i;
1293         }
1294
1295         drv->state_count = i;
1296
1297         return 0;
1298 }
1299
1300 /**
1301  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1302  * global state data i.e. idle routines
1303  *
1304  * @pr: the ACPI processor
1305  */
1306 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1307 {
1308         int i;
1309         struct cpuidle_driver *drv = &acpi_idle_driver;
1310
1311         if (!pr->flags.power_setup_done || !pr->flags.power)
1312                 return -EINVAL;
1313
1314         drv->safe_state_index = -1;
1315         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1316                 drv->states[i].name[0] = '\0';
1317                 drv->states[i].desc[0] = '\0';
1318         }
1319
1320         if (pr->flags.has_lpi)
1321                 return acpi_processor_setup_lpi_states(pr);
1322
1323         return acpi_processor_setup_cstates(pr);
1324 }
1325
1326 /**
1327  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1328  * device i.e. per-cpu data
1329  *
1330  * @pr: the ACPI processor
1331  * @dev : the cpuidle device
1332  */
1333 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1334                                             struct cpuidle_device *dev)
1335 {
1336         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1337                 return -EINVAL;
1338
1339         dev->cpu = pr->id;
1340         if (pr->flags.has_lpi)
1341                 return acpi_processor_ffh_lpi_probe(pr->id);
1342
1343         return acpi_processor_setup_cpuidle_cx(pr, dev);
1344 }
1345
1346 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1347 {
1348         int ret;
1349
1350         ret = acpi_processor_get_lpi_info(pr);
1351         if (ret)
1352                 ret = acpi_processor_get_cstate_info(pr);
1353
1354         return ret;
1355 }
1356
1357 int acpi_processor_hotplug(struct acpi_processor *pr)
1358 {
1359         int ret = 0;
1360         struct cpuidle_device *dev;
1361
1362         if (disabled_by_idle_boot_param())
1363                 return 0;
1364
1365         if (!pr->flags.power_setup_done)
1366                 return -ENODEV;
1367
1368         dev = per_cpu(acpi_cpuidle_device, pr->id);
1369         cpuidle_pause_and_lock();
1370         cpuidle_disable_device(dev);
1371         ret = acpi_processor_get_power_info(pr);
1372         if (!ret && pr->flags.power) {
1373                 acpi_processor_setup_cpuidle_dev(pr, dev);
1374                 ret = cpuidle_enable_device(dev);
1375         }
1376         cpuidle_resume_and_unlock();
1377
1378         return ret;
1379 }
1380
1381 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1382 {
1383         int cpu;
1384         struct acpi_processor *_pr;
1385         struct cpuidle_device *dev;
1386
1387         if (disabled_by_idle_boot_param())
1388                 return 0;
1389
1390         if (!pr->flags.power_setup_done)
1391                 return -ENODEV;
1392
1393         /*
1394          * FIXME:  Design the ACPI notification to make it once per
1395          * system instead of once per-cpu.  This condition is a hack
1396          * to make the code that updates C-States be called once.
1397          */
1398
1399         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1400
1401                 /* Protect against cpu-hotplug */
1402                 get_online_cpus();
1403                 cpuidle_pause_and_lock();
1404
1405                 /* Disable all cpuidle devices */
1406                 for_each_online_cpu(cpu) {
1407                         _pr = per_cpu(processors, cpu);
1408                         if (!_pr || !_pr->flags.power_setup_done)
1409                                 continue;
1410                         dev = per_cpu(acpi_cpuidle_device, cpu);
1411                         cpuidle_disable_device(dev);
1412                 }
1413
1414                 /* Populate Updated C-state information */
1415                 acpi_processor_get_power_info(pr);
1416                 acpi_processor_setup_cpuidle_states(pr);
1417
1418                 /* Enable all cpuidle devices */
1419                 for_each_online_cpu(cpu) {
1420                         _pr = per_cpu(processors, cpu);
1421                         if (!_pr || !_pr->flags.power_setup_done)
1422                                 continue;
1423                         acpi_processor_get_power_info(_pr);
1424                         if (_pr->flags.power) {
1425                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1426                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1427                                 cpuidle_enable_device(dev);
1428                         }
1429                 }
1430                 cpuidle_resume_and_unlock();
1431                 put_online_cpus();
1432         }
1433
1434         return 0;
1435 }
1436
1437 static int acpi_processor_registered;
1438
1439 int acpi_processor_power_init(struct acpi_processor *pr)
1440 {
1441         int retval;
1442         struct cpuidle_device *dev;
1443
1444         if (disabled_by_idle_boot_param())
1445                 return 0;
1446
1447         acpi_processor_cstate_first_run_checks();
1448
1449         if (!acpi_processor_get_power_info(pr))
1450                 pr->flags.power_setup_done = 1;
1451
1452         /*
1453          * Install the idle handler if processor power management is supported.
1454          * Note that we use previously set idle handler will be used on
1455          * platforms that only support C1.
1456          */
1457         if (pr->flags.power) {
1458                 /* Register acpi_idle_driver if not already registered */
1459                 if (!acpi_processor_registered) {
1460                         acpi_processor_setup_cpuidle_states(pr);
1461                         retval = cpuidle_register_driver(&acpi_idle_driver);
1462                         if (retval)
1463                                 return retval;
1464                         pr_debug("%s registered with cpuidle\n",
1465                                  acpi_idle_driver.name);
1466                 }
1467
1468                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1469                 if (!dev)
1470                         return -ENOMEM;
1471                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1472
1473                 acpi_processor_setup_cpuidle_dev(pr, dev);
1474
1475                 /* Register per-cpu cpuidle_device. Cpuidle driver
1476                  * must already be registered before registering device
1477                  */
1478                 retval = cpuidle_register_device(dev);
1479                 if (retval) {
1480                         if (acpi_processor_registered == 0)
1481                                 cpuidle_unregister_driver(&acpi_idle_driver);
1482                         return retval;
1483                 }
1484                 acpi_processor_registered++;
1485         }
1486         return 0;
1487 }
1488
1489 int acpi_processor_power_exit(struct acpi_processor *pr)
1490 {
1491         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1492
1493         if (disabled_by_idle_boot_param())
1494                 return 0;
1495
1496         if (pr->flags.power) {
1497                 cpuidle_unregister_device(dev);
1498                 acpi_processor_registered--;
1499                 if (acpi_processor_registered == 0)
1500                         cpuidle_unregister_driver(&acpi_idle_driver);
1501         }
1502
1503         pr->flags.power_setup_done = 0;
1504         return 0;
1505 }