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
49ACPI_MODULE_NAME("processor_idle");
50
51#define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
52
53static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
54module_param(max_cstate, uint, 0000);
55static unsigned int nocst __read_mostly;
56module_param(nocst, uint, 0000);
57static int bm_check_disable __read_mostly;
58module_param(bm_check_disable, uint, 0000);
59
60static unsigned int latency_factor __read_mostly = 2;
61module_param(latency_factor, uint, 0644);
62
63static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
64
65struct cpuidle_driver acpi_idle_driver = {
66 .name = "acpi_idle",
67 .owner = THIS_MODULE,
68};
69
70#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
71static
72DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
73
74static 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 */
86static 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
100static 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 */
121static 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 */
137static 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
160static 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
170static 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 */
177static 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
193static void lapic_timer_check_state(int state, struct acpi_processor *pr,
194 struct acpi_processor_cx *cstate) { }
195static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
196static 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)
205static 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
227static void tsc_check_state(int state) { return; }
228#endif
229
230static 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
295static 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
312static 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
474static 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
555static 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
593static 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 */
634static 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 */
663static 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 */
685static 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
707static 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
713static int c3_cpu_count;
714static 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 */
722static 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
766static 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
806static 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
827static 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
855static 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
913static 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
937static inline int disabled_by_idle_boot_param(void) { return 0; }
938static inline void acpi_processor_cstate_first_run_checks(void) { }
939static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
940{
941 return -ENODEV;
942}
943
944static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
945 struct cpuidle_device *dev)
946{
947 return -EINVAL;
948}
949
950static int acpi_processor_setup_cstates(struct acpi_processor *pr)
951{
952 return -EINVAL;
953}
954
955#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
956
957struct 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
964static 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
973static 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);
1079end:
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 */
1087static 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 */
1096static 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
1125static 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
1131static 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
1176static 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
1235int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1236{
1237 return -ENODEV;
1238}
1239
1240int __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 */
1253static 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
1271static 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 */
1306static 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 */
1333static 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
1346static 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
1357int 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
1381int 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
1437static int acpi_processor_registered;
1438
1439int 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
1489int 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}
1506