GNU Linux-libre 4.4.289-gnu1
[releases.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
27 #include <linux/module.h>
28 #include <linux/acpi.h>
29 #include <linux/dmi.h>
30 #include <linux/sched.h>       /* need_resched() */
31 #include <linux/sort.h>
32 #include <linux/tick.h>
33 #include <linux/cpuidle.h>
34 #include <linux/syscore_ops.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 PREFIX "ACPI: "
48
49 #define ACPI_PROCESSOR_CLASS            "processor"
50 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
51 ACPI_MODULE_NAME("processor_idle");
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 static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
66                                                                 acpi_cstate);
67
68 static int disabled_by_idle_boot_param(void)
69 {
70         return boot_option_idle_override == IDLE_POLL ||
71                 boot_option_idle_override == IDLE_HALT;
72 }
73
74 /*
75  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
76  * For now disable this. Probably a bug somewhere else.
77  *
78  * To skip this limit, boot/load with a large max_cstate limit.
79  */
80 static int set_max_cstate(const struct dmi_system_id *id)
81 {
82         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
83                 return 0;
84
85         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
86                " Override with \"processor.max_cstate=%d\"\n", id->ident,
87                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
88
89         max_cstate = (long)id->driver_data;
90
91         return 0;
92 }
93
94 static const struct dmi_system_id processor_power_dmi_table[] = {
95         { set_max_cstate, "Clevo 5600D", {
96           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
97           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
98          (void *)2},
99         { set_max_cstate, "Pavilion zv5000", {
100           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
101           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
102          (void *)1},
103         { set_max_cstate, "Asus L8400B", {
104           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
105           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
106          (void *)1},
107         {},
108 };
109
110
111 /*
112  * Callers should disable interrupts before the call and enable
113  * interrupts after return.
114  */
115 static void acpi_safe_halt(void)
116 {
117         if (!tif_need_resched()) {
118                 safe_halt();
119                 local_irq_disable();
120         }
121 }
122
123 #ifdef ARCH_APICTIMER_STOPS_ON_C3
124
125 /*
126  * Some BIOS implementations switch to C3 in the published C2 state.
127  * This seems to be a common problem on AMD boxen, but other vendors
128  * are affected too. We pick the most conservative approach: we assume
129  * that the local APIC stops in both C2 and C3.
130  */
131 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
132                                    struct acpi_processor_cx *cx)
133 {
134         struct acpi_processor_power *pwr = &pr->power;
135         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
136
137         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
138                 return;
139
140         if (amd_e400_c1e_detected)
141                 type = ACPI_STATE_C1;
142
143         /*
144          * Check, if one of the previous states already marked the lapic
145          * unstable
146          */
147         if (pwr->timer_broadcast_on_state < state)
148                 return;
149
150         if (cx->type >= type)
151                 pr->power.timer_broadcast_on_state = state;
152 }
153
154 static void __lapic_timer_propagate_broadcast(void *arg)
155 {
156         struct acpi_processor *pr = (struct acpi_processor *) arg;
157
158         if (pr->power.timer_broadcast_on_state < INT_MAX)
159                 tick_broadcast_enable();
160         else
161                 tick_broadcast_disable();
162 }
163
164 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
165 {
166         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
167                                  (void *)pr, 1);
168 }
169
170 /* Power(C) State timer broadcast control */
171 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
172                                        struct acpi_processor_cx *cx,
173                                        int broadcast)
174 {
175         int state = cx - pr->power.states;
176
177         if (state >= pr->power.timer_broadcast_on_state) {
178                 if (broadcast)
179                         tick_broadcast_enter();
180                 else
181                         tick_broadcast_exit();
182         }
183 }
184
185 #else
186
187 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
188                                    struct acpi_processor_cx *cstate) { }
189 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
190 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
191                                        struct acpi_processor_cx *cx,
192                                        int broadcast)
193 {
194 }
195
196 #endif
197
198 #ifdef CONFIG_PM_SLEEP
199 static u32 saved_bm_rld;
200
201 static int acpi_processor_suspend(void)
202 {
203         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
204         return 0;
205 }
206
207 static void acpi_processor_resume(void)
208 {
209         u32 resumed_bm_rld = 0;
210
211         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
212         if (resumed_bm_rld == saved_bm_rld)
213                 return;
214
215         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
216 }
217
218 static struct syscore_ops acpi_processor_syscore_ops = {
219         .suspend = acpi_processor_suspend,
220         .resume = acpi_processor_resume,
221 };
222
223 void acpi_processor_syscore_init(void)
224 {
225         register_syscore_ops(&acpi_processor_syscore_ops);
226 }
227
228 void acpi_processor_syscore_exit(void)
229 {
230         unregister_syscore_ops(&acpi_processor_syscore_ops);
231 }
232 #endif /* CONFIG_PM_SLEEP */
233
234 #if defined(CONFIG_X86)
235 static void tsc_check_state(int state)
236 {
237         switch (boot_cpu_data.x86_vendor) {
238         case X86_VENDOR_AMD:
239         case X86_VENDOR_INTEL:
240                 /*
241                  * AMD Fam10h TSC will tick in all
242                  * C/P/S0/S1 states when this bit is set.
243                  */
244                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
245                         return;
246
247                 /*FALL THROUGH*/
248         default:
249                 /* TSC could halt in idle, so notify users */
250                 if (state > ACPI_STATE_C1)
251                         mark_tsc_unstable("TSC halts in idle");
252         }
253 }
254 #else
255 static void tsc_check_state(int state) { return; }
256 #endif
257
258 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
259 {
260
261         if (!pr->pblk)
262                 return -ENODEV;
263
264         /* if info is obtained from pblk/fadt, type equals state */
265         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
266         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
267
268 #ifndef CONFIG_HOTPLUG_CPU
269         /*
270          * Check for P_LVL2_UP flag before entering C2 and above on
271          * an SMP system.
272          */
273         if ((num_online_cpus() > 1) &&
274             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
275                 return -ENODEV;
276 #endif
277
278         /* determine C2 and C3 address from pblk */
279         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
280         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
281
282         /* determine latencies from FADT */
283         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
284         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
285
286         /*
287          * FADT specified C2 latency must be less than or equal to
288          * 100 microseconds.
289          */
290         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
291                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
292                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
293                 /* invalidate C2 */
294                 pr->power.states[ACPI_STATE_C2].address = 0;
295         }
296
297         /*
298          * FADT supplied C3 latency must be less than or equal to
299          * 1000 microseconds.
300          */
301         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
302                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
303                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
304                 /* invalidate C3 */
305                 pr->power.states[ACPI_STATE_C3].address = 0;
306         }
307
308         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
309                           "lvl2[0x%08x] lvl3[0x%08x]\n",
310                           pr->power.states[ACPI_STATE_C2].address,
311                           pr->power.states[ACPI_STATE_C3].address));
312
313         return 0;
314 }
315
316 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
317 {
318         if (!pr->power.states[ACPI_STATE_C1].valid) {
319                 /* set the first C-State to C1 */
320                 /* all processors need to support C1 */
321                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
322                 pr->power.states[ACPI_STATE_C1].valid = 1;
323                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
324         }
325         /* the C0 state only exists as a filler in our array */
326         pr->power.states[ACPI_STATE_C0].valid = 1;
327         return 0;
328 }
329
330 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
331 {
332         acpi_status status;
333         u64 count;
334         int current_count;
335         int i, ret = 0;
336         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
337         union acpi_object *cst;
338
339
340         if (nocst)
341                 return -ENODEV;
342
343         current_count = 0;
344
345         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
346         if (ACPI_FAILURE(status)) {
347                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
348                 return -ENODEV;
349         }
350
351         cst = buffer.pointer;
352
353         /* There must be at least 2 elements */
354         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
355                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
356                 ret = -EFAULT;
357                 goto end;
358         }
359
360         count = cst->package.elements[0].integer.value;
361
362         /* Validate number of power states. */
363         if (count < 1 || count != cst->package.count - 1) {
364                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
365                 ret = -EFAULT;
366                 goto end;
367         }
368
369         /* Tell driver that at least _CST is supported. */
370         pr->flags.has_cst = 1;
371
372         for (i = 1; i <= count; i++) {
373                 union acpi_object *element;
374                 union acpi_object *obj;
375                 struct acpi_power_register *reg;
376                 struct acpi_processor_cx cx;
377
378                 memset(&cx, 0, sizeof(cx));
379
380                 element = &(cst->package.elements[i]);
381                 if (element->type != ACPI_TYPE_PACKAGE)
382                         continue;
383
384                 if (element->package.count != 4)
385                         continue;
386
387                 obj = &(element->package.elements[0]);
388
389                 if (obj->type != ACPI_TYPE_BUFFER)
390                         continue;
391
392                 reg = (struct acpi_power_register *)obj->buffer.pointer;
393
394                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
395                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
396                         continue;
397
398                 /* There should be an easy way to extract an integer... */
399                 obj = &(element->package.elements[1]);
400                 if (obj->type != ACPI_TYPE_INTEGER)
401                         continue;
402
403                 cx.type = obj->integer.value;
404                 /*
405                  * Some buggy BIOSes won't list C1 in _CST -
406                  * Let acpi_processor_get_power_info_default() handle them later
407                  */
408                 if (i == 1 && cx.type != ACPI_STATE_C1)
409                         current_count++;
410
411                 cx.address = reg->address;
412                 cx.index = current_count + 1;
413
414                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
415                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
416                         if (acpi_processor_ffh_cstate_probe
417                                         (pr->id, &cx, reg) == 0) {
418                                 cx.entry_method = ACPI_CSTATE_FFH;
419                         } else if (cx.type == ACPI_STATE_C1) {
420                                 /*
421                                  * C1 is a special case where FIXED_HARDWARE
422                                  * can be handled in non-MWAIT way as well.
423                                  * In that case, save this _CST entry info.
424                                  * Otherwise, ignore this info and continue.
425                                  */
426                                 cx.entry_method = ACPI_CSTATE_HALT;
427                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
428                         } else {
429                                 continue;
430                         }
431                         if (cx.type == ACPI_STATE_C1 &&
432                             (boot_option_idle_override == IDLE_NOMWAIT)) {
433                                 /*
434                                  * In most cases the C1 space_id obtained from
435                                  * _CST object is FIXED_HARDWARE access mode.
436                                  * But when the option of idle=halt is added,
437                                  * the entry_method type should be changed from
438                                  * CSTATE_FFH to CSTATE_HALT.
439                                  * When the option of idle=nomwait is added,
440                                  * the C1 entry_method type should be
441                                  * CSTATE_HALT.
442                                  */
443                                 cx.entry_method = ACPI_CSTATE_HALT;
444                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
445                         }
446                 } else {
447                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
448                                  cx.address);
449                 }
450
451                 if (cx.type == ACPI_STATE_C1) {
452                         cx.valid = 1;
453                 }
454
455                 obj = &(element->package.elements[2]);
456                 if (obj->type != ACPI_TYPE_INTEGER)
457                         continue;
458
459                 cx.latency = obj->integer.value;
460
461                 obj = &(element->package.elements[3]);
462                 if (obj->type != ACPI_TYPE_INTEGER)
463                         continue;
464
465                 current_count++;
466                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
467
468                 /*
469                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
470                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
471                  */
472                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
473                         printk(KERN_WARNING
474                                "Limiting number of power states to max (%d)\n",
475                                ACPI_PROCESSOR_MAX_POWER);
476                         printk(KERN_WARNING
477                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
478                         break;
479                 }
480         }
481
482         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
483                           current_count));
484
485         /* Validate number of power states discovered */
486         if (current_count < 2)
487                 ret = -EFAULT;
488
489       end:
490         kfree(buffer.pointer);
491
492         return ret;
493 }
494
495 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
496                                            struct acpi_processor_cx *cx)
497 {
498         static int bm_check_flag = -1;
499         static int bm_control_flag = -1;
500
501
502         if (!cx->address)
503                 return;
504
505         /*
506          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
507          * DMA transfers are used by any ISA device to avoid livelock.
508          * Note that we could disable Type-F DMA (as recommended by
509          * the erratum), but this is known to disrupt certain ISA
510          * devices thus we take the conservative approach.
511          */
512         else if (errata.piix4.fdma) {
513                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
514                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
515                 return;
516         }
517
518         /* All the logic here assumes flags.bm_check is same across all CPUs */
519         if (bm_check_flag == -1) {
520                 /* Determine whether bm_check is needed based on CPU  */
521                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
522                 bm_check_flag = pr->flags.bm_check;
523                 bm_control_flag = pr->flags.bm_control;
524         } else {
525                 pr->flags.bm_check = bm_check_flag;
526                 pr->flags.bm_control = bm_control_flag;
527         }
528
529         if (pr->flags.bm_check) {
530                 if (!pr->flags.bm_control) {
531                         if (pr->flags.has_cst != 1) {
532                                 /* bus mastering control is necessary */
533                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
534                                         "C3 support requires BM control\n"));
535                                 return;
536                         } else {
537                                 /* Here we enter C3 without bus mastering */
538                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
539                                         "C3 support without BM control\n"));
540                         }
541                 }
542         } else {
543                 /*
544                  * WBINVD should be set in fadt, for C3 state to be
545                  * supported on when bm_check is not required.
546                  */
547                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
548                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
549                                           "Cache invalidation should work properly"
550                                           " for C3 to be enabled on SMP systems\n"));
551                         return;
552                 }
553         }
554
555         /*
556          * Otherwise we've met all of our C3 requirements.
557          * Normalize the C3 latency to expidite policy.  Enable
558          * checking of bus mastering status (bm_check) so we can
559          * use this in our C3 policy
560          */
561         cx->valid = 1;
562
563         /*
564          * On older chipsets, BM_RLD needs to be set
565          * in order for Bus Master activity to wake the
566          * system from C3.  Newer chipsets handle DMA
567          * during C3 automatically and BM_RLD is a NOP.
568          * In either case, the proper way to
569          * handle BM_RLD is to set it and leave it set.
570          */
571         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
572
573         return;
574 }
575
576 static int acpi_cst_latency_cmp(const void *a, const void *b)
577 {
578         const struct acpi_processor_cx *x = a, *y = b;
579
580         if (!(x->valid && y->valid))
581                 return 0;
582         if (x->latency > y->latency)
583                 return 1;
584         if (x->latency < y->latency)
585                 return -1;
586         return 0;
587 }
588 static void acpi_cst_latency_swap(void *a, void *b, int n)
589 {
590         struct acpi_processor_cx *x = a, *y = b;
591         u32 tmp;
592
593         if (!(x->valid && y->valid))
594                 return;
595         tmp = x->latency;
596         x->latency = y->latency;
597         y->latency = tmp;
598 }
599
600 static int acpi_processor_power_verify(struct acpi_processor *pr)
601 {
602         unsigned int i;
603         unsigned int working = 0;
604         unsigned int last_latency = 0;
605         unsigned int last_type = 0;
606         bool buggy_latency = false;
607
608         pr->power.timer_broadcast_on_state = INT_MAX;
609
610         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
611                 struct acpi_processor_cx *cx = &pr->power.states[i];
612
613                 switch (cx->type) {
614                 case ACPI_STATE_C1:
615                         cx->valid = 1;
616                         break;
617
618                 case ACPI_STATE_C2:
619                         if (!cx->address)
620                                 break;
621                         cx->valid = 1;
622                         break;
623
624                 case ACPI_STATE_C3:
625                         acpi_processor_power_verify_c3(pr, cx);
626                         break;
627                 }
628                 if (!cx->valid)
629                         continue;
630                 if (cx->type >= last_type && cx->latency < last_latency)
631                         buggy_latency = true;
632                 last_latency = cx->latency;
633                 last_type = cx->type;
634
635                 lapic_timer_check_state(i, pr, cx);
636                 tsc_check_state(cx->type);
637                 working++;
638         }
639
640         if (buggy_latency) {
641                 pr_notice("FW issue: working around C-state latencies out of order\n");
642                 sort(&pr->power.states[1], max_cstate,
643                      sizeof(struct acpi_processor_cx),
644                      acpi_cst_latency_cmp,
645                      acpi_cst_latency_swap);
646         }
647
648         lapic_timer_propagate_broadcast(pr);
649
650         return (working);
651 }
652
653 static int acpi_processor_get_power_info(struct acpi_processor *pr)
654 {
655         unsigned int i;
656         int result;
657
658
659         /* NOTE: the idle thread may not be running while calling
660          * this function */
661
662         /* Zero initialize all the C-states info. */
663         memset(pr->power.states, 0, sizeof(pr->power.states));
664
665         result = acpi_processor_get_power_info_cst(pr);
666         if (result == -ENODEV)
667                 result = acpi_processor_get_power_info_fadt(pr);
668
669         if (result)
670                 return result;
671
672         acpi_processor_get_power_info_default(pr);
673
674         pr->power.count = acpi_processor_power_verify(pr);
675
676         /*
677          * if one state of type C2 or C3 is available, mark this
678          * CPU as being "idle manageable"
679          */
680         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
681                 if (pr->power.states[i].valid) {
682                         pr->power.count = i;
683                         if (pr->power.states[i].type >= ACPI_STATE_C2)
684                                 pr->flags.power = 1;
685                 }
686         }
687
688         return 0;
689 }
690
691 /**
692  * acpi_idle_bm_check - checks if bus master activity was detected
693  */
694 static int acpi_idle_bm_check(void)
695 {
696         u32 bm_status = 0;
697
698         if (bm_check_disable)
699                 return 0;
700
701         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
702         if (bm_status)
703                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
704         /*
705          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
706          * the true state of bus mastering activity; forcing us to
707          * manually check the BMIDEA bit of each IDE channel.
708          */
709         else if (errata.piix4.bmisx) {
710                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
711                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
712                         bm_status = 1;
713         }
714         return bm_status;
715 }
716
717 /**
718  * acpi_idle_do_entry - enter idle state using the appropriate method
719  * @cx: cstate data
720  *
721  * Caller disables interrupt before call and enables interrupt after return.
722  */
723 static void acpi_idle_do_entry(struct acpi_processor_cx *cx)
724 {
725         if (cx->entry_method == ACPI_CSTATE_FFH) {
726                 /* Call into architectural FFH based C-state */
727                 acpi_processor_ffh_cstate_enter(cx);
728         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
729                 acpi_safe_halt();
730         } else {
731                 /* IO port based C-state */
732                 inb(cx->address);
733                 /* Dummy wait op - must do something useless after P_LVL2 read
734                    because chipsets cannot guarantee that STPCLK# signal
735                    gets asserted in time to freeze execution properly. */
736                 inl(acpi_gbl_FADT.xpm_timer_block.address);
737         }
738 }
739
740 /**
741  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
742  * @dev: the target CPU
743  * @index: the index of suggested state
744  */
745 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
746 {
747         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
748
749         ACPI_FLUSH_CPU_CACHE();
750
751         while (1) {
752
753                 if (cx->entry_method == ACPI_CSTATE_HALT)
754                         safe_halt();
755                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
756                         inb(cx->address);
757                         /* See comment in acpi_idle_do_entry() */
758                         inl(acpi_gbl_FADT.xpm_timer_block.address);
759                 } else
760                         return -ENODEV;
761         }
762
763         /* Never reached */
764         return 0;
765 }
766
767 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
768 {
769         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
770                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
771 }
772
773 static int c3_cpu_count;
774 static DEFINE_RAW_SPINLOCK(c3_lock);
775
776 /**
777  * acpi_idle_enter_bm - enters C3 with proper BM handling
778  * @pr: Target processor
779  * @cx: Target state context
780  * @timer_bc: Whether or not to change timer mode to broadcast
781  */
782 static void acpi_idle_enter_bm(struct acpi_processor *pr,
783                                struct acpi_processor_cx *cx, bool timer_bc)
784 {
785         acpi_unlazy_tlb(smp_processor_id());
786
787         /*
788          * Must be done before busmaster disable as we might need to
789          * access HPET !
790          */
791         if (timer_bc)
792                 lapic_timer_state_broadcast(pr, cx, 1);
793
794         /*
795          * disable bus master
796          * bm_check implies we need ARB_DIS
797          * bm_control implies whether we can do ARB_DIS
798          *
799          * That leaves a case where bm_check is set and bm_control is
800          * not set. In that case we cannot do much, we enter C3
801          * without doing anything.
802          */
803         if (pr->flags.bm_control) {
804                 raw_spin_lock(&c3_lock);
805                 c3_cpu_count++;
806                 /* Disable bus master arbitration when all CPUs are in C3 */
807                 if (c3_cpu_count == num_online_cpus())
808                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
809                 raw_spin_unlock(&c3_lock);
810         }
811
812         acpi_idle_do_entry(cx);
813
814         /* Re-enable bus master arbitration */
815         if (pr->flags.bm_control) {
816                 raw_spin_lock(&c3_lock);
817                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
818                 c3_cpu_count--;
819                 raw_spin_unlock(&c3_lock);
820         }
821
822         if (timer_bc)
823                 lapic_timer_state_broadcast(pr, cx, 0);
824 }
825
826 static int acpi_idle_enter(struct cpuidle_device *dev,
827                            struct cpuidle_driver *drv, int index)
828 {
829         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
830         struct acpi_processor *pr;
831
832         pr = __this_cpu_read(processors);
833         if (unlikely(!pr))
834                 return -EINVAL;
835
836         if (cx->type != ACPI_STATE_C1) {
837                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
838                         index = CPUIDLE_DRIVER_STATE_START;
839                         cx = per_cpu(acpi_cstate[index], dev->cpu);
840                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
841                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
842                                 acpi_idle_enter_bm(pr, cx, true);
843                                 return index;
844                         } else if (drv->safe_state_index >= 0) {
845                                 index = drv->safe_state_index;
846                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
847                         } else {
848                                 acpi_safe_halt();
849                                 return -EBUSY;
850                         }
851                 }
852         }
853
854         lapic_timer_state_broadcast(pr, cx, 1);
855
856         if (cx->type == ACPI_STATE_C3)
857                 ACPI_FLUSH_CPU_CACHE();
858
859         acpi_idle_do_entry(cx);
860
861         lapic_timer_state_broadcast(pr, cx, 0);
862
863         return index;
864 }
865
866 static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
867                                    struct cpuidle_driver *drv, int index)
868 {
869         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
870
871         if (cx->type == ACPI_STATE_C3) {
872                 struct acpi_processor *pr = __this_cpu_read(processors);
873
874                 if (unlikely(!pr))
875                         return;
876
877                 if (pr->flags.bm_check) {
878                         acpi_idle_enter_bm(pr, cx, false);
879                         return;
880                 } else {
881                         ACPI_FLUSH_CPU_CACHE();
882                 }
883         }
884         acpi_idle_do_entry(cx);
885 }
886
887 struct cpuidle_driver acpi_idle_driver = {
888         .name =         "acpi_idle",
889         .owner =        THIS_MODULE,
890 };
891
892 /**
893  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
894  * device i.e. per-cpu data
895  *
896  * @pr: the ACPI processor
897  * @dev : the cpuidle device
898  */
899 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
900                                            struct cpuidle_device *dev)
901 {
902         int i, count = CPUIDLE_DRIVER_STATE_START;
903         struct acpi_processor_cx *cx;
904
905         if (!pr->flags.power_setup_done)
906                 return -EINVAL;
907
908         if (pr->flags.power == 0) {
909                 return -EINVAL;
910         }
911
912         if (!dev)
913                 return -EINVAL;
914
915         dev->cpu = pr->id;
916
917         if (max_cstate == 0)
918                 max_cstate = 1;
919
920         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
921                 cx = &pr->power.states[i];
922
923                 if (!cx->valid)
924                         continue;
925
926                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
927
928                 count++;
929                 if (count == CPUIDLE_STATE_MAX)
930                         break;
931         }
932
933         if (!count)
934                 return -EINVAL;
935
936         return 0;
937 }
938
939 /**
940  * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
941  * global state data i.e. idle routines
942  *
943  * @pr: the ACPI processor
944  */
945 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
946 {
947         int i, count = CPUIDLE_DRIVER_STATE_START;
948         struct acpi_processor_cx *cx;
949         struct cpuidle_state *state;
950         struct cpuidle_driver *drv = &acpi_idle_driver;
951
952         if (!pr->flags.power_setup_done)
953                 return -EINVAL;
954
955         if (pr->flags.power == 0)
956                 return -EINVAL;
957
958         drv->safe_state_index = -1;
959         for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
960                 drv->states[i].name[0] = '\0';
961                 drv->states[i].desc[0] = '\0';
962         }
963
964         if (max_cstate == 0)
965                 max_cstate = 1;
966
967         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
968                 cx = &pr->power.states[i];
969
970                 if (!cx->valid)
971                         continue;
972
973                 state = &drv->states[count];
974                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
975                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
976                 state->exit_latency = cx->latency;
977                 state->target_residency = cx->latency * latency_factor;
978                 state->enter = acpi_idle_enter;
979
980                 state->flags = 0;
981                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
982                         state->enter_dead = acpi_idle_play_dead;
983                         drv->safe_state_index = count;
984                 }
985                 /*
986                  * Halt-induced C1 is not good for ->enter_freeze, because it
987                  * re-enables interrupts on exit.  Moreover, C1 is generally not
988                  * particularly interesting from the suspend-to-idle angle, so
989                  * avoid C1 and the situations in which we may need to fall back
990                  * to it altogether.
991                  */
992                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
993                         state->enter_freeze = acpi_idle_enter_freeze;
994
995                 count++;
996                 if (count == CPUIDLE_STATE_MAX)
997                         break;
998         }
999
1000         drv->state_count = count;
1001
1002         if (!count)
1003                 return -EINVAL;
1004
1005         return 0;
1006 }
1007
1008 int acpi_processor_hotplug(struct acpi_processor *pr)
1009 {
1010         int ret = 0;
1011         struct cpuidle_device *dev;
1012
1013         if (disabled_by_idle_boot_param())
1014                 return 0;
1015
1016         if (nocst)
1017                 return -ENODEV;
1018
1019         if (!pr->flags.power_setup_done)
1020                 return -ENODEV;
1021
1022         dev = per_cpu(acpi_cpuidle_device, pr->id);
1023         cpuidle_pause_and_lock();
1024         cpuidle_disable_device(dev);
1025         acpi_processor_get_power_info(pr);
1026         if (pr->flags.power) {
1027                 acpi_processor_setup_cpuidle_cx(pr, dev);
1028                 ret = cpuidle_enable_device(dev);
1029         }
1030         cpuidle_resume_and_unlock();
1031
1032         return ret;
1033 }
1034
1035 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1036 {
1037         int cpu;
1038         struct acpi_processor *_pr;
1039         struct cpuidle_device *dev;
1040
1041         if (disabled_by_idle_boot_param())
1042                 return 0;
1043
1044         if (nocst)
1045                 return -ENODEV;
1046
1047         if (!pr->flags.power_setup_done)
1048                 return -ENODEV;
1049
1050         /*
1051          * FIXME:  Design the ACPI notification to make it once per
1052          * system instead of once per-cpu.  This condition is a hack
1053          * to make the code that updates C-States be called once.
1054          */
1055
1056         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1057
1058                 /* Protect against cpu-hotplug */
1059                 get_online_cpus();
1060                 cpuidle_pause_and_lock();
1061
1062                 /* Disable all cpuidle devices */
1063                 for_each_online_cpu(cpu) {
1064                         _pr = per_cpu(processors, cpu);
1065                         if (!_pr || !_pr->flags.power_setup_done)
1066                                 continue;
1067                         dev = per_cpu(acpi_cpuidle_device, cpu);
1068                         cpuidle_disable_device(dev);
1069                 }
1070
1071                 /* Populate Updated C-state information */
1072                 acpi_processor_get_power_info(pr);
1073                 acpi_processor_setup_cpuidle_states(pr);
1074
1075                 /* Enable all cpuidle devices */
1076                 for_each_online_cpu(cpu) {
1077                         _pr = per_cpu(processors, cpu);
1078                         if (!_pr || !_pr->flags.power_setup_done)
1079                                 continue;
1080                         acpi_processor_get_power_info(_pr);
1081                         if (_pr->flags.power) {
1082                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1083                                 acpi_processor_setup_cpuidle_cx(_pr, dev);
1084                                 cpuidle_enable_device(dev);
1085                         }
1086                 }
1087                 cpuidle_resume_and_unlock();
1088                 put_online_cpus();
1089         }
1090
1091         return 0;
1092 }
1093
1094 static int acpi_processor_registered;
1095
1096 int acpi_processor_power_init(struct acpi_processor *pr)
1097 {
1098         acpi_status status;
1099         int retval;
1100         struct cpuidle_device *dev;
1101         static int first_run;
1102
1103         if (disabled_by_idle_boot_param())
1104                 return 0;
1105
1106         if (!first_run) {
1107                 dmi_check_system(processor_power_dmi_table);
1108                 max_cstate = acpi_processor_cstate_check(max_cstate);
1109                 if (max_cstate < ACPI_C_STATES_MAX)
1110                         printk(KERN_NOTICE
1111                                "ACPI: processor limited to max C-state %d\n",
1112                                max_cstate);
1113                 first_run++;
1114         }
1115
1116         if (acpi_gbl_FADT.cst_control && !nocst) {
1117                 status =
1118                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1119                 if (ACPI_FAILURE(status)) {
1120                         ACPI_EXCEPTION((AE_INFO, status,
1121                                         "Notifying BIOS of _CST ability failed"));
1122                 }
1123         }
1124
1125         acpi_processor_get_power_info(pr);
1126         pr->flags.power_setup_done = 1;
1127
1128         /*
1129          * Install the idle handler if processor power management is supported.
1130          * Note that we use previously set idle handler will be used on
1131          * platforms that only support C1.
1132          */
1133         if (pr->flags.power) {
1134                 /* Register acpi_idle_driver if not already registered */
1135                 if (!acpi_processor_registered) {
1136                         acpi_processor_setup_cpuidle_states(pr);
1137                         retval = cpuidle_register_driver(&acpi_idle_driver);
1138                         if (retval)
1139                                 return retval;
1140                         printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1141                                         acpi_idle_driver.name);
1142                 }
1143
1144                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1145                 if (!dev)
1146                         return -ENOMEM;
1147                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1148
1149                 acpi_processor_setup_cpuidle_cx(pr, dev);
1150
1151                 /* Register per-cpu cpuidle_device. Cpuidle driver
1152                  * must already be registered before registering device
1153                  */
1154                 retval = cpuidle_register_device(dev);
1155                 if (retval) {
1156                         if (acpi_processor_registered == 0)
1157                                 cpuidle_unregister_driver(&acpi_idle_driver);
1158                         return retval;
1159                 }
1160                 acpi_processor_registered++;
1161         }
1162         return 0;
1163 }
1164
1165 int acpi_processor_power_exit(struct acpi_processor *pr)
1166 {
1167         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1168
1169         if (disabled_by_idle_boot_param())
1170                 return 0;
1171
1172         if (pr->flags.power) {
1173                 cpuidle_unregister_device(dev);
1174                 acpi_processor_registered--;
1175                 if (acpi_processor_registered == 0)
1176                         cpuidle_unregister_driver(&acpi_idle_driver);
1177         }
1178
1179         pr->flags.power_setup_done = 0;
1180         return 0;
1181 }