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[cor.git] / drivers / acpi / processor_idle.c
blob2ae95df2e74f8861c0c8a50eec3332f4b0dc3318
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * processor_idle - idle state submodule to the ACPI processor driver
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9 * - Added processor hotplug support
10 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
11 * - Added support for C3 on SMP
12 */
13 #define pr_fmt(fmt) "ACPI: " fmt
14
15 #include <linux/module.h>
16 #include <linux/acpi.h>
17 #include <linux/dmi.h>
18 #include <linux/sched.h> /* need_resched() */
19 #include <linux/tick.h>
20 #include <linux/cpuidle.h>
21 #include <linux/cpu.h>
22 #include <acpi/processor.h>
23
24 /*
25 * Include the apic definitions for x86 to have the APIC timer related defines
26 * available also for UP (on SMP it gets magically included via linux/smp.h).
27 * asm/acpi.h is not an option, as it would require more include magic. Also
28 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
29 */
30 #ifdef CONFIG_X86
31 #include <asm/apic.h>
32 #endif
33
34 #define ACPI_PROCESSOR_CLASS "processor"
35 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
36 ACPI_MODULE_NAME("processor_idle");
37
38 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
39
40 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
41 module_param(max_cstate, uint, 0000);
42 static unsigned int nocst __read_mostly;
43 module_param(nocst, uint, 0000);
44 static int bm_check_disable __read_mostly;
45 module_param(bm_check_disable, uint, 0000);
46
47 static unsigned int latency_factor __read_mostly = 2;
48 module_param(latency_factor, uint, 0644);
49
50 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
51
52 struct cpuidle_driver acpi_idle_driver = {
53 .name = "acpi_idle",
54 .owner = THIS_MODULE,
55 };
56
57 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
58 static
59 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
60
61 static int disabled_by_idle_boot_param(void)
62 {
63 return boot_option_idle_override == IDLE_POLL ||
64 boot_option_idle_override == IDLE_HALT;
65 }
66
67 /*
68 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
69 * For now disable this. Probably a bug somewhere else.
70 *
71 * To skip this limit, boot/load with a large max_cstate limit.
72 */
73 static int set_max_cstate(const struct dmi_system_id *id)
74 {
75 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
76 return 0;
77
78 pr_notice("%s detected - limiting to C%ld max_cstate."
79 " Override with \"processor.max_cstate=%d\"\n", id->ident,
80 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
81
82 max_cstate = (long)id->driver_data;
83
84 return 0;
85 }
86
87 static const struct dmi_system_id processor_power_dmi_table[] = {
88 { set_max_cstate, "Clevo 5600D", {
89 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
90 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
91 (void *)2},
92 { set_max_cstate, "Pavilion zv5000", {
93 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
94 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
95 (void *)1},
96 { set_max_cstate, "Asus L8400B", {
97 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
98 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
99 (void *)1},
100 {},
101 };
102
103
104 /*
105 * Callers should disable interrupts before the call and enable
106 * interrupts after return.
107 */
108 static void __cpuidle acpi_safe_halt(void)
109 {
110 if (!tif_need_resched()) {
111 safe_halt();
112 local_irq_disable();
113 }
114 }
115
116 #ifdef ARCH_APICTIMER_STOPS_ON_C3
117
118 /*
119 * Some BIOS implementations switch to C3 in the published C2 state.
120 * This seems to be a common problem on AMD boxen, but other vendors
121 * are affected too. We pick the most conservative approach: we assume
122 * that the local APIC stops in both C2 and C3.
123 */
124 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
125 struct acpi_processor_cx *cx)
126 {
127 struct acpi_processor_power *pwr = &pr->power;
128 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
129
130 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
131 return;
132
133 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
134 type = ACPI_STATE_C1;
135
136 /*
137 * Check, if one of the previous states already marked the lapic
138 * unstable
139 */
140 if (pwr->timer_broadcast_on_state < state)
141 return;
142
143 if (cx->type >= type)
144 pr->power.timer_broadcast_on_state = state;
145 }
146
147 static void __lapic_timer_propagate_broadcast(void *arg)
148 {
149 struct acpi_processor *pr = (struct acpi_processor *) arg;
150
151 if (pr->power.timer_broadcast_on_state < INT_MAX)
152 tick_broadcast_enable();
153 else
154 tick_broadcast_disable();
155 }
156
157 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
158 {
159 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
160 (void *)pr, 1);
161 }
162
163 /* Power(C) State timer broadcast control */
164 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
165 struct acpi_processor_cx *cx,
166 int broadcast)
167 {
168 int state = cx - pr->power.states;
169
170 if (state >= pr->power.timer_broadcast_on_state) {
171 if (broadcast)
172 tick_broadcast_enter();
173 else
174 tick_broadcast_exit();
175 }
176 }
177
178 #else
179
180 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
181 struct acpi_processor_cx *cstate) { }
182 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
183 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
184 struct acpi_processor_cx *cx,
185 int broadcast)
186 {
187 }
188
189 #endif
190
191 #if defined(CONFIG_X86)
192 static void tsc_check_state(int state)
193 {
194 switch (boot_cpu_data.x86_vendor) {
195 case X86_VENDOR_HYGON:
196 case X86_VENDOR_AMD:
197 case X86_VENDOR_INTEL:
198 case X86_VENDOR_CENTAUR:
199 case X86_VENDOR_ZHAOXIN:
200 /*
201 * AMD Fam10h TSC will tick in all
202 * C/P/S0/S1 states when this bit is set.
203 */
204 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
205 return;
206
207 /*FALL THROUGH*/
208 default:
209 /* TSC could halt in idle, so notify users */
210 if (state > ACPI_STATE_C1)
211 mark_tsc_unstable("TSC halts in idle");
212 }
213 }
214 #else
215 static void tsc_check_state(int state) { return; }
216 #endif
217
218 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
219 {
220
221 if (!pr->pblk)
222 return -ENODEV;
223
224 /* if info is obtained from pblk/fadt, type equals state */
225 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
226 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
227
228 #ifndef CONFIG_HOTPLUG_CPU
229 /*
230 * Check for P_LVL2_UP flag before entering C2 and above on
231 * an SMP system.
232 */
233 if ((num_online_cpus() > 1) &&
234 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
235 return -ENODEV;
236 #endif
237
238 /* determine C2 and C3 address from pblk */
239 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
240 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
241
242 /* determine latencies from FADT */
243 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
244 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
245
246 /*
247 * FADT specified C2 latency must be less than or equal to
248 * 100 microseconds.
249 */
250 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
251 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
252 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
253 /* invalidate C2 */
254 pr->power.states[ACPI_STATE_C2].address = 0;
255 }
256
257 /*
258 * FADT supplied C3 latency must be less than or equal to
259 * 1000 microseconds.
260 */
261 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
262 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
263 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
264 /* invalidate C3 */
265 pr->power.states[ACPI_STATE_C3].address = 0;
266 }
267
268 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
269 "lvl2[0x%08x] lvl3[0x%08x]\n",
270 pr->power.states[ACPI_STATE_C2].address,
271 pr->power.states[ACPI_STATE_C3].address));
272
273 snprintf(pr->power.states[ACPI_STATE_C2].desc,
274 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
275 pr->power.states[ACPI_STATE_C2].address);
276 snprintf(pr->power.states[ACPI_STATE_C3].desc,
277 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
278 pr->power.states[ACPI_STATE_C3].address);
279
280 return 0;
281 }
282
283 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
284 {
285 if (!pr->power.states[ACPI_STATE_C1].valid) {
286 /* set the first C-State to C1 */
287 /* all processors need to support C1 */
288 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
289 pr->power.states[ACPI_STATE_C1].valid = 1;
290 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
291
292 snprintf(pr->power.states[ACPI_STATE_C1].desc,
293 ACPI_CX_DESC_LEN, "ACPI HLT");
294 }
295 /* the C0 state only exists as a filler in our array */
296 pr->power.states[ACPI_STATE_C0].valid = 1;
297 return 0;
298 }
299
300 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
301 {
302 acpi_status status;
303 u64 count;
304 int current_count;
305 int i, ret = 0;
306 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
307 union acpi_object *cst;
308
309 if (nocst)
310 return -ENODEV;
311
312 current_count = 0;
313
314 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
315 if (ACPI_FAILURE(status)) {
316 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
317 return -ENODEV;
318 }
319
320 cst = buffer.pointer;
321
322 /* There must be at least 2 elements */
323 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
324 pr_err("not enough elements in _CST\n");
325 ret = -EFAULT;
326 goto end;
327 }
328
329 count = cst->package.elements[0].integer.value;
330
331 /* Validate number of power states. */
332 if (count < 1 || count != cst->package.count - 1) {
333 pr_err("count given by _CST is not valid\n");
334 ret = -EFAULT;
335 goto end;
336 }
337
338 /* Tell driver that at least _CST is supported. */
339 pr->flags.has_cst = 1;
340
341 for (i = 1; i <= count; i++) {
342 union acpi_object *element;
343 union acpi_object *obj;
344 struct acpi_power_register *reg;
345 struct acpi_processor_cx cx;
346
347 memset(&cx, 0, sizeof(cx));
348
349 element = &(cst->package.elements[i]);
350 if (element->type != ACPI_TYPE_PACKAGE)
351 continue;
352
353 if (element->package.count != 4)
354 continue;
355
356 obj = &(element->package.elements[0]);
357
358 if (obj->type != ACPI_TYPE_BUFFER)
359 continue;
360
361 reg = (struct acpi_power_register *)obj->buffer.pointer;
362
363 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
364 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
365 continue;
366
367 /* There should be an easy way to extract an integer... */
368 obj = &(element->package.elements[1]);
369 if (obj->type != ACPI_TYPE_INTEGER)
370 continue;
371
372 cx.type = obj->integer.value;
373 /*
374 * Some buggy BIOSes won't list C1 in _CST -
375 * Let acpi_processor_get_power_info_default() handle them later
376 */
377 if (i == 1 && cx.type != ACPI_STATE_C1)
378 current_count++;
379
380 cx.address = reg->address;
381 cx.index = current_count + 1;
382
383 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
384 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
385 if (acpi_processor_ffh_cstate_probe
386 (pr->id, &cx, reg) == 0) {
387 cx.entry_method = ACPI_CSTATE_FFH;
388 } else if (cx.type == ACPI_STATE_C1) {
389 /*
390 * C1 is a special case where FIXED_HARDWARE
391 * can be handled in non-MWAIT way as well.
392 * In that case, save this _CST entry info.
393 * Otherwise, ignore this info and continue.
394 */
395 cx.entry_method = ACPI_CSTATE_HALT;
396 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
397 } else {
398 continue;
399 }
400 if (cx.type == ACPI_STATE_C1 &&
401 (boot_option_idle_override == IDLE_NOMWAIT)) {
402 /*
403 * In most cases the C1 space_id obtained from
404 * _CST object is FIXED_HARDWARE access mode.
405 * But when the option of idle=halt is added,
406 * the entry_method type should be changed from
407 * CSTATE_FFH to CSTATE_HALT.
408 * When the option of idle=nomwait is added,
409 * the C1 entry_method type should be
410 * CSTATE_HALT.
411 */
412 cx.entry_method = ACPI_CSTATE_HALT;
413 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
414 }
415 } else {
416 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
417 cx.address);
418 }
419
420 if (cx.type == ACPI_STATE_C1) {
421 cx.valid = 1;
422 }
423
424 obj = &(element->package.elements[2]);
425 if (obj->type != ACPI_TYPE_INTEGER)
426 continue;
427
428 cx.latency = obj->integer.value;
429
430 obj = &(element->package.elements[3]);
431 if (obj->type != ACPI_TYPE_INTEGER)
432 continue;
433
434 current_count++;
435 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
436
437 /*
438 * We support total ACPI_PROCESSOR_MAX_POWER - 1
439 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
440 */
441 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
442 pr_warn("Limiting number of power states to max (%d)\n",
443 ACPI_PROCESSOR_MAX_POWER);
444 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
445 break;
446 }
447 }
448
449 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
450 current_count));
451
452 /* Validate number of power states discovered */
453 if (current_count < 2)
454 ret = -EFAULT;
455
456 end:
457 kfree(buffer.pointer);
458
459 return ret;
460 }
461
462 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
463 struct acpi_processor_cx *cx)
464 {
465 static int bm_check_flag = -1;
466 static int bm_control_flag = -1;
467
468
469 if (!cx->address)
470 return;
471
472 /*
473 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
474 * DMA transfers are used by any ISA device to avoid livelock.
475 * Note that we could disable Type-F DMA (as recommended by
476 * the erratum), but this is known to disrupt certain ISA
477 * devices thus we take the conservative approach.
478 */
479 else if (errata.piix4.fdma) {
480 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
481 "C3 not supported on PIIX4 with Type-F DMA\n"));
482 return;
483 }
484
485 /* All the logic here assumes flags.bm_check is same across all CPUs */
486 if (bm_check_flag == -1) {
487 /* Determine whether bm_check is needed based on CPU */
488 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
489 bm_check_flag = pr->flags.bm_check;
490 bm_control_flag = pr->flags.bm_control;
491 } else {
492 pr->flags.bm_check = bm_check_flag;
493 pr->flags.bm_control = bm_control_flag;
494 }
495
496 if (pr->flags.bm_check) {
497 if (!pr->flags.bm_control) {
498 if (pr->flags.has_cst != 1) {
499 /* bus mastering control is necessary */
500 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
501 "C3 support requires BM control\n"));
502 return;
503 } else {
504 /* Here we enter C3 without bus mastering */
505 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
506 "C3 support without BM control\n"));
507 }
508 }
509 } else {
510 /*
511 * WBINVD should be set in fadt, for C3 state to be
512 * supported on when bm_check is not required.
513 */
514 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
515 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
516 "Cache invalidation should work properly"
517 " for C3 to be enabled on SMP systems\n"));
518 return;
519 }
520 }
521
522 /*
523 * Otherwise we've met all of our C3 requirements.
524 * Normalize the C3 latency to expidite policy. Enable
525 * checking of bus mastering status (bm_check) so we can
526 * use this in our C3 policy
527 */
528 cx->valid = 1;
529
530 /*
531 * On older chipsets, BM_RLD needs to be set
532 * in order for Bus Master activity to wake the
533 * system from C3. Newer chipsets handle DMA
534 * during C3 automatically and BM_RLD is a NOP.
535 * In either case, the proper way to
536 * handle BM_RLD is to set it and leave it set.
537 */
538 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
539
540 return;
541 }
542
543 static int acpi_processor_power_verify(struct acpi_processor *pr)
544 {
545 unsigned int i;
546 unsigned int working = 0;
547
548 pr->power.timer_broadcast_on_state = INT_MAX;
549
550 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
551 struct acpi_processor_cx *cx = &pr->power.states[i];
552
553 switch (cx->type) {
554 case ACPI_STATE_C1:
555 cx->valid = 1;
556 break;
557
558 case ACPI_STATE_C2:
559 if (!cx->address)
560 break;
561 cx->valid = 1;
562 break;
563
564 case ACPI_STATE_C3:
565 acpi_processor_power_verify_c3(pr, cx);
566 break;
567 }
568 if (!cx->valid)
569 continue;
570
571 lapic_timer_check_state(i, pr, cx);
572 tsc_check_state(cx->type);
573 working++;
574 }
575
576 lapic_timer_propagate_broadcast(pr);
577
578 return (working);
579 }
580
581 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
582 {
583 unsigned int i;
584 int result;
585
586
587 /* NOTE: the idle thread may not be running while calling
588 * this function */
589
590 /* Zero initialize all the C-states info. */
591 memset(pr->power.states, 0, sizeof(pr->power.states));
592
593 result = acpi_processor_get_power_info_cst(pr);
594 if (result == -ENODEV)
595 result = acpi_processor_get_power_info_fadt(pr);
596
597 if (result)
598 return result;
599
600 acpi_processor_get_power_info_default(pr);
601
602 pr->power.count = acpi_processor_power_verify(pr);
603
604 /*
605 * if one state of type C2 or C3 is available, mark this
606 * CPU as being "idle manageable"
607 */
608 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
609 if (pr->power.states[i].valid) {
610 pr->power.count = i;
611 if (pr->power.states[i].type >= ACPI_STATE_C2)
612 pr->flags.power = 1;
613 }
614 }
615
616 return 0;
617 }
618
619 /**
620 * acpi_idle_bm_check - checks if bus master activity was detected
621 */
622 static int acpi_idle_bm_check(void)
623 {
624 u32 bm_status = 0;
625
626 if (bm_check_disable)
627 return 0;
628
629 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
630 if (bm_status)
631 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
632 /*
633 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
634 * the true state of bus mastering activity; forcing us to
635 * manually check the BMIDEA bit of each IDE channel.
636 */
637 else if (errata.piix4.bmisx) {
638 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
639 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
640 bm_status = 1;
641 }
642 return bm_status;
643 }
644
645 static void wait_for_freeze(void)
646 {
647 #ifdef CONFIG_X86
648 /* No delay is needed if we are in guest */
649 if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
650 return;
651 #endif
652 /* Dummy wait op - must do something useless after P_LVL2 read
653 because chipsets cannot guarantee that STPCLK# signal
654 gets asserted in time to freeze execution properly. */
655 inl(acpi_gbl_FADT.xpm_timer_block.address);
656 }
657
658 /**
659 * acpi_idle_do_entry - enter idle state using the appropriate method
660 * @cx: cstate data
661 *
662 * Caller disables interrupt before call and enables interrupt after return.
663 */
664 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
665 {
666 if (cx->entry_method == ACPI_CSTATE_FFH) {
667 /* Call into architectural FFH based C-state */
668 acpi_processor_ffh_cstate_enter(cx);
669 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
670 acpi_safe_halt();
671 } else {
672 /* IO port based C-state */
673 inb(cx->address);
674 wait_for_freeze();
675 }
676 }
677
678 /**
679 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
680 * @dev: the target CPU
681 * @index: the index of suggested state
682 */
683 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
684 {
685 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
686
687 ACPI_FLUSH_CPU_CACHE();
688
689 while (1) {
690
691 if (cx->entry_method == ACPI_CSTATE_HALT)
692 safe_halt();
693 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
694 inb(cx->address);
695 wait_for_freeze();
696 } else
697 return -ENODEV;
698 }
699
700 /* Never reached */
701 return 0;
702 }
703
704 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
705 {
706 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
707 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
708 }
709
710 static int c3_cpu_count;
711 static DEFINE_RAW_SPINLOCK(c3_lock);
712
713 /**
714 * acpi_idle_enter_bm - enters C3 with proper BM handling
715 * @pr: Target processor
716 * @cx: Target state context
717 * @timer_bc: Whether or not to change timer mode to broadcast
718 */
719 static void acpi_idle_enter_bm(struct acpi_processor *pr,
720 struct acpi_processor_cx *cx, bool timer_bc)
721 {
722 acpi_unlazy_tlb(smp_processor_id());
723
724 /*
725 * Must be done before busmaster disable as we might need to
726 * access HPET !
727 */
728 if (timer_bc)
729 lapic_timer_state_broadcast(pr, cx, 1);
730
731 /*
732 * disable bus master
733 * bm_check implies we need ARB_DIS
734 * bm_control implies whether we can do ARB_DIS
735 *
736 * That leaves a case where bm_check is set and bm_control is
737 * not set. In that case we cannot do much, we enter C3
738 * without doing anything.
739 */
740 if (pr->flags.bm_control) {
741 raw_spin_lock(&c3_lock);
742 c3_cpu_count++;
743 /* Disable bus master arbitration when all CPUs are in C3 */
744 if (c3_cpu_count == num_online_cpus())
745 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
746 raw_spin_unlock(&c3_lock);
747 }
748
749 acpi_idle_do_entry(cx);
750
751 /* Re-enable bus master arbitration */
752 if (pr->flags.bm_control) {
753 raw_spin_lock(&c3_lock);
754 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
755 c3_cpu_count--;
756 raw_spin_unlock(&c3_lock);
757 }
758
759 if (timer_bc)
760 lapic_timer_state_broadcast(pr, cx, 0);
761 }
762
763 static int acpi_idle_enter(struct cpuidle_device *dev,
764 struct cpuidle_driver *drv, int index)
765 {
766 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
767 struct acpi_processor *pr;
768
769 pr = __this_cpu_read(processors);
770 if (unlikely(!pr))
771 return -EINVAL;
772
773 if (cx->type != ACPI_STATE_C1) {
774 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
775 index = ACPI_IDLE_STATE_START;
776 cx = per_cpu(acpi_cstate[index], dev->cpu);
777 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
778 if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
779 acpi_idle_enter_bm(pr, cx, true);
780 return index;
781 } else if (drv->safe_state_index >= 0) {
782 index = drv->safe_state_index;
783 cx = per_cpu(acpi_cstate[index], dev->cpu);
784 } else {
785 acpi_safe_halt();
786 return -EBUSY;
787 }
788 }
789 }
790
791 lapic_timer_state_broadcast(pr, cx, 1);
792
793 if (cx->type == ACPI_STATE_C3)
794 ACPI_FLUSH_CPU_CACHE();
795
796 acpi_idle_do_entry(cx);
797
798 lapic_timer_state_broadcast(pr, cx, 0);
799
800 return index;
801 }
802
803 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
804 struct cpuidle_driver *drv, int index)
805 {
806 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
807
808 if (cx->type == ACPI_STATE_C3) {
809 struct acpi_processor *pr = __this_cpu_read(processors);
810
811 if (unlikely(!pr))
812 return;
813
814 if (pr->flags.bm_check) {
815 acpi_idle_enter_bm(pr, cx, false);
816 return;
817 } else {
818 ACPI_FLUSH_CPU_CACHE();
819 }
820 }
821 acpi_idle_do_entry(cx);
822 }
823
824 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
825 struct cpuidle_device *dev)
826 {
827 int i, count = ACPI_IDLE_STATE_START;
828 struct acpi_processor_cx *cx;
829
830 if (max_cstate == 0)
831 max_cstate = 1;
832
833 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
834 cx = &pr->power.states[i];
835
836 if (!cx->valid)
837 continue;
838
839 per_cpu(acpi_cstate[count], dev->cpu) = cx;
840
841 count++;
842 if (count == CPUIDLE_STATE_MAX)
843 break;
844 }
845
846 if (!count)
847 return -EINVAL;
848
849 return 0;
850 }
851
852 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
853 {
854 int i, count;
855 struct acpi_processor_cx *cx;
856 struct cpuidle_state *state;
857 struct cpuidle_driver *drv = &acpi_idle_driver;
858
859 if (max_cstate == 0)
860 max_cstate = 1;
861
862 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
863 cpuidle_poll_state_init(drv);
864 count = 1;
865 } else {
866 count = 0;
867 }
868
869 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
870 cx = &pr->power.states[i];
871
872 if (!cx->valid)
873 continue;
874
875 state = &drv->states[count];
876 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
877 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
878 state->exit_latency = cx->latency;
879 state->target_residency = cx->latency * latency_factor;
880 state->enter = acpi_idle_enter;
881
882 state->flags = 0;
883 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
884 state->enter_dead = acpi_idle_play_dead;
885 drv->safe_state_index = count;
886 }
887 /*
888 * Halt-induced C1 is not good for ->enter_s2idle, because it
889 * re-enables interrupts on exit. Moreover, C1 is generally not
890 * particularly interesting from the suspend-to-idle angle, so
891 * avoid C1 and the situations in which we may need to fall back
892 * to it altogether.
893 */
894 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
895 state->enter_s2idle = acpi_idle_enter_s2idle;
896
897 count++;
898 if (count == CPUIDLE_STATE_MAX)
899 break;
900 }
901
902 drv->state_count = count;
903
904 if (!count)
905 return -EINVAL;
906
907 return 0;
908 }
909
910 static inline void acpi_processor_cstate_first_run_checks(void)
911 {
912 acpi_status status;
913 static int first_run;
914
915 if (first_run)
916 return;
917 dmi_check_system(processor_power_dmi_table);
918 max_cstate = acpi_processor_cstate_check(max_cstate);
919 if (max_cstate < ACPI_C_STATES_MAX)
920 pr_notice("ACPI: processor limited to max C-state %d\n",
921 max_cstate);
922 first_run++;
923
924 if (acpi_gbl_FADT.cst_control && !nocst) {
925 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
926 acpi_gbl_FADT.cst_control, 8);
927 if (ACPI_FAILURE(status))
928 ACPI_EXCEPTION((AE_INFO, status,
929 "Notifying BIOS of _CST ability failed"));
930 }
931 }
932 #else
933
934 static inline int disabled_by_idle_boot_param(void) { return 0; }
935 static inline void acpi_processor_cstate_first_run_checks(void) { }
936 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
937 {
938 return -ENODEV;
939 }
940
941 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
942 struct cpuidle_device *dev)
943 {
944 return -EINVAL;
945 }
946
947 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
948 {
949 return -EINVAL;
950 }
951
952 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
953
954 struct acpi_lpi_states_array {
955 unsigned int size;
956 unsigned int composite_states_size;
957 struct acpi_lpi_state *entries;
958 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
959 };
960
961 static int obj_get_integer(union acpi_object *obj, u32 *value)
962 {
963 if (obj->type != ACPI_TYPE_INTEGER)
964 return -EINVAL;
965
966 *value = obj->integer.value;
967 return 0;
968 }
969
970 static int acpi_processor_evaluate_lpi(acpi_handle handle,
971 struct acpi_lpi_states_array *info)
972 {
973 acpi_status status;
974 int ret = 0;
975 int pkg_count, state_idx = 1, loop;
976 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
977 union acpi_object *lpi_data;
978 struct acpi_lpi_state *lpi_state;
979
980 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
981 if (ACPI_FAILURE(status)) {
982 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
983 return -ENODEV;
984 }
985
986 lpi_data = buffer.pointer;
987
988 /* There must be at least 4 elements = 3 elements + 1 package */
989 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
990 lpi_data->package.count < 4) {
991 pr_debug("not enough elements in _LPI\n");
992 ret = -ENODATA;
993 goto end;
994 }
995
996 pkg_count = lpi_data->package.elements[2].integer.value;
997
998 /* Validate number of power states. */
999 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
1000 pr_debug("count given by _LPI is not valid\n");
1001 ret = -ENODATA;
1002 goto end;
1003 }
1004
1005 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1006 if (!lpi_state) {
1007 ret = -ENOMEM;
1008 goto end;
1009 }
1010
1011 info->size = pkg_count;
1012 info->entries = lpi_state;
1013
1014 /* LPI States start at index 3 */
1015 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1016 union acpi_object *element, *pkg_elem, *obj;
1017
1018 element = &lpi_data->package.elements[loop];
1019 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1020 continue;
1021
1022 pkg_elem = element->package.elements;
1023
1024 obj = pkg_elem + 6;
1025 if (obj->type == ACPI_TYPE_BUFFER) {
1026 struct acpi_power_register *reg;
1027
1028 reg = (struct acpi_power_register *)obj->buffer.pointer;
1029 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1030 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1031 continue;
1032
1033 lpi_state->address = reg->address;
1034 lpi_state->entry_method =
1035 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1036 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1037 } else if (obj->type == ACPI_TYPE_INTEGER) {
1038 lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1039 lpi_state->address = obj->integer.value;
1040 } else {
1041 continue;
1042 }
1043
1044 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1045
1046 obj = pkg_elem + 9;
1047 if (obj->type == ACPI_TYPE_STRING)
1048 strlcpy(lpi_state->desc, obj->string.pointer,
1049 ACPI_CX_DESC_LEN);
1050
1051 lpi_state->index = state_idx;
1052 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1053 pr_debug("No min. residency found, assuming 10 us\n");
1054 lpi_state->min_residency = 10;
1055 }
1056
1057 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1058 pr_debug("No wakeup residency found, assuming 10 us\n");
1059 lpi_state->wake_latency = 10;
1060 }
1061
1062 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1063 lpi_state->flags = 0;
1064
1065 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1066 lpi_state->arch_flags = 0;
1067
1068 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1069 lpi_state->res_cnt_freq = 1;
1070
1071 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1072 lpi_state->enable_parent_state = 0;
1073 }
1074
1075 acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1076 end:
1077 kfree(buffer.pointer);
1078 return ret;
1079 }
1080
1081 /*
1082 * flat_state_cnt - the number of composite LPI states after the process of flattening
1083 */
1084 static int flat_state_cnt;
1085
1086 /**
1087 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1088 *
1089 * @local: local LPI state
1090 * @parent: parent LPI state
1091 * @result: composite LPI state
1092 */
1093 static bool combine_lpi_states(struct acpi_lpi_state *local,
1094 struct acpi_lpi_state *parent,
1095 struct acpi_lpi_state *result)
1096 {
1097 if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1098 if (!parent->address) /* 0 means autopromotable */
1099 return false;
1100 result->address = local->address + parent->address;
1101 } else {
1102 result->address = parent->address;
1103 }
1104
1105 result->min_residency = max(local->min_residency, parent->min_residency);
1106 result->wake_latency = local->wake_latency + parent->wake_latency;
1107 result->enable_parent_state = parent->enable_parent_state;
1108 result->entry_method = local->entry_method;
1109
1110 result->flags = parent->flags;
1111 result->arch_flags = parent->arch_flags;
1112 result->index = parent->index;
1113
1114 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1115 strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1116 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1117 return true;
1118 }
1119
1120 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0)
1121
1122 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1123 struct acpi_lpi_state *t)
1124 {
1125 curr_level->composite_states[curr_level->composite_states_size++] = t;
1126 }
1127
1128 static int flatten_lpi_states(struct acpi_processor *pr,
1129 struct acpi_lpi_states_array *curr_level,
1130 struct acpi_lpi_states_array *prev_level)
1131 {
1132 int i, j, state_count = curr_level->size;
1133 struct acpi_lpi_state *p, *t = curr_level->entries;
1134
1135 curr_level->composite_states_size = 0;
1136 for (j = 0; j < state_count; j++, t++) {
1137 struct acpi_lpi_state *flpi;
1138
1139 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1140 continue;
1141
1142 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1143 pr_warn("Limiting number of LPI states to max (%d)\n",
1144 ACPI_PROCESSOR_MAX_POWER);
1145 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1146 break;
1147 }
1148
1149 flpi = &pr->power.lpi_states[flat_state_cnt];
1150
1151 if (!prev_level) { /* leaf/processor node */
1152 memcpy(flpi, t, sizeof(*t));
1153 stash_composite_state(curr_level, flpi);
1154 flat_state_cnt++;
1155 continue;
1156 }
1157
1158 for (i = 0; i < prev_level->composite_states_size; i++) {
1159 p = prev_level->composite_states[i];
1160 if (t->index <= p->enable_parent_state &&
1161 combine_lpi_states(p, t, flpi)) {
1162 stash_composite_state(curr_level, flpi);
1163 flat_state_cnt++;
1164 flpi++;
1165 }
1166 }
1167 }
1168
1169 kfree(curr_level->entries);
1170 return 0;
1171 }
1172
1173 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1174 {
1175 int ret, i;
1176 acpi_status status;
1177 acpi_handle handle = pr->handle, pr_ahandle;
1178 struct acpi_device *d = NULL;
1179 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1180
1181 if (!osc_pc_lpi_support_confirmed)
1182 return -EOPNOTSUPP;
1183
1184 if (!acpi_has_method(handle, "_LPI"))
1185 return -EINVAL;
1186
1187 flat_state_cnt = 0;
1188 prev = &info[0];
1189 curr = &info[1];
1190 handle = pr->handle;
1191 ret = acpi_processor_evaluate_lpi(handle, prev);
1192 if (ret)
1193 return ret;
1194 flatten_lpi_states(pr, prev, NULL);
1195
1196 status = acpi_get_parent(handle, &pr_ahandle);
1197 while (ACPI_SUCCESS(status)) {
1198 acpi_bus_get_device(pr_ahandle, &d);
1199 handle = pr_ahandle;
1200
1201 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1202 break;
1203
1204 /* can be optional ? */
1205 if (!acpi_has_method(handle, "_LPI"))
1206 break;
1207
1208 ret = acpi_processor_evaluate_lpi(handle, curr);
1209 if (ret)
1210 break;
1211
1212 /* flatten all the LPI states in this level of hierarchy */
1213 flatten_lpi_states(pr, curr, prev);
1214
1215 tmp = prev, prev = curr, curr = tmp;
1216
1217 status = acpi_get_parent(handle, &pr_ahandle);
1218 }
1219
1220 pr->power.count = flat_state_cnt;
1221 /* reset the index after flattening */
1222 for (i = 0; i < pr->power.count; i++)
1223 pr->power.lpi_states[i].index = i;
1224
1225 /* Tell driver that _LPI is supported. */
1226 pr->flags.has_lpi = 1;
1227 pr->flags.power = 1;
1228
1229 return 0;
1230 }
1231
1232 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1233 {
1234 return -ENODEV;
1235 }
1236
1237 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1238 {
1239 return -ENODEV;
1240 }
1241
1242 /**
1243 * acpi_idle_lpi_enter - enters an ACPI any LPI state
1244 * @dev: the target CPU
1245 * @drv: cpuidle driver containing cpuidle state info
1246 * @index: index of target state
1247 *
1248 * Return: 0 for success or negative value for error
1249 */
1250 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1251 struct cpuidle_driver *drv, int index)
1252 {
1253 struct acpi_processor *pr;
1254 struct acpi_lpi_state *lpi;
1255
1256 pr = __this_cpu_read(processors);
1257
1258 if (unlikely(!pr))
1259 return -EINVAL;
1260
1261 lpi = &pr->power.lpi_states[index];
1262 if (lpi->entry_method == ACPI_CSTATE_FFH)
1263 return acpi_processor_ffh_lpi_enter(lpi);
1264
1265 return -EINVAL;
1266 }
1267
1268 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1269 {
1270 int i;
1271 struct acpi_lpi_state *lpi;
1272 struct cpuidle_state *state;
1273 struct cpuidle_driver *drv = &acpi_idle_driver;
1274
1275 if (!pr->flags.has_lpi)
1276 return -EOPNOTSUPP;
1277
1278 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1279 lpi = &pr->power.lpi_states[i];
1280
1281 state = &drv->states[i];
1282 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1283 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1284 state->exit_latency = lpi->wake_latency;
1285 state->target_residency = lpi->min_residency;
1286 if (lpi->arch_flags)
1287 state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1288 state->enter = acpi_idle_lpi_enter;
1289 drv->safe_state_index = i;
1290 }
1291
1292 drv->state_count = i;
1293
1294 return 0;
1295 }
1296
1297 /**
1298 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1299 * global state data i.e. idle routines
1300 *
1301 * @pr: the ACPI processor
1302 */
1303 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1304 {
1305 int i;
1306 struct cpuidle_driver *drv = &acpi_idle_driver;
1307
1308 if (!pr->flags.power_setup_done || !pr->flags.power)
1309 return -EINVAL;
1310
1311 drv->safe_state_index = -1;
1312 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1313 drv->states[i].name[0] = '\0';
1314 drv->states[i].desc[0] = '\0';
1315 }
1316
1317 if (pr->flags.has_lpi)
1318 return acpi_processor_setup_lpi_states(pr);
1319
1320 return acpi_processor_setup_cstates(pr);
1321 }
1322
1323 /**
1324 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1325 * device i.e. per-cpu data
1326 *
1327 * @pr: the ACPI processor
1328 * @dev : the cpuidle device
1329 */
1330 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1331 struct cpuidle_device *dev)
1332 {
1333 if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1334 return -EINVAL;
1335
1336 dev->cpu = pr->id;
1337 if (pr->flags.has_lpi)
1338 return acpi_processor_ffh_lpi_probe(pr->id);
1339
1340 return acpi_processor_setup_cpuidle_cx(pr, dev);
1341 }
1342
1343 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1344 {
1345 int ret;
1346
1347 ret = acpi_processor_get_lpi_info(pr);
1348 if (ret)
1349 ret = acpi_processor_get_cstate_info(pr);
1350
1351 return ret;
1352 }
1353
1354 int acpi_processor_hotplug(struct acpi_processor *pr)
1355 {
1356 int ret = 0;
1357 struct cpuidle_device *dev;
1358
1359 if (disabled_by_idle_boot_param())
1360 return 0;
1361
1362 if (!pr->flags.power_setup_done)
1363 return -ENODEV;
1364
1365 dev = per_cpu(acpi_cpuidle_device, pr->id);
1366 cpuidle_pause_and_lock();
1367 cpuidle_disable_device(dev);
1368 ret = acpi_processor_get_power_info(pr);
1369 if (!ret && pr->flags.power) {
1370 acpi_processor_setup_cpuidle_dev(pr, dev);
1371 ret = cpuidle_enable_device(dev);
1372 }
1373 cpuidle_resume_and_unlock();
1374
1375 return ret;
1376 }
1377
1378 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1379 {
1380 int cpu;
1381 struct acpi_processor *_pr;
1382 struct cpuidle_device *dev;
1383
1384 if (disabled_by_idle_boot_param())
1385 return 0;
1386
1387 if (!pr->flags.power_setup_done)
1388 return -ENODEV;
1389
1390 /*
1391 * FIXME: Design the ACPI notification to make it once per
1392 * system instead of once per-cpu. This condition is a hack
1393 * to make the code that updates C-States be called once.
1394 */
1395
1396 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1397
1398 /* Protect against cpu-hotplug */
1399 get_online_cpus();
1400 cpuidle_pause_and_lock();
1401
1402 /* Disable all cpuidle devices */
1403 for_each_online_cpu(cpu) {
1404 _pr = per_cpu(processors, cpu);
1405 if (!_pr || !_pr->flags.power_setup_done)
1406 continue;
1407 dev = per_cpu(acpi_cpuidle_device, cpu);
1408 cpuidle_disable_device(dev);
1409 }
1410
1411 /* Populate Updated C-state information */
1412 acpi_processor_get_power_info(pr);
1413 acpi_processor_setup_cpuidle_states(pr);
1414
1415 /* Enable all cpuidle devices */
1416 for_each_online_cpu(cpu) {
1417 _pr = per_cpu(processors, cpu);
1418 if (!_pr || !_pr->flags.power_setup_done)
1419 continue;
1420 acpi_processor_get_power_info(_pr);
1421 if (_pr->flags.power) {
1422 dev = per_cpu(acpi_cpuidle_device, cpu);
1423 acpi_processor_setup_cpuidle_dev(_pr, dev);
1424 cpuidle_enable_device(dev);
1425 }
1426 }
1427 cpuidle_resume_and_unlock();
1428 put_online_cpus();
1429 }
1430
1431 return 0;
1432 }
1433
1434 static int acpi_processor_registered;
1435
1436 int acpi_processor_power_init(struct acpi_processor *pr)
1437 {
1438 int retval;
1439 struct cpuidle_device *dev;
1440
1441 if (disabled_by_idle_boot_param())
1442 return 0;
1443
1444 acpi_processor_cstate_first_run_checks();
1445
1446 if (!acpi_processor_get_power_info(pr))
1447 pr->flags.power_setup_done = 1;
1448
1449 /*
1450 * Install the idle handler if processor power management is supported.
1451 * Note that we use previously set idle handler will be used on
1452 * platforms that only support C1.
1453 */
1454 if (pr->flags.power) {
1455 /* Register acpi_idle_driver if not already registered */
1456 if (!acpi_processor_registered) {
1457 acpi_processor_setup_cpuidle_states(pr);
1458 retval = cpuidle_register_driver(&acpi_idle_driver);
1459 if (retval)
1460 return retval;
1461 pr_debug("%s registered with cpuidle\n",
1462 acpi_idle_driver.name);
1463 }
1464
1465 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1466 if (!dev)
1467 return -ENOMEM;
1468 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1469
1470 acpi_processor_setup_cpuidle_dev(pr, dev);
1471
1472 /* Register per-cpu cpuidle_device. Cpuidle driver
1473 * must already be registered before registering device
1474 */
1475 retval = cpuidle_register_device(dev);
1476 if (retval) {
1477 if (acpi_processor_registered == 0)
1478 cpuidle_unregister_driver(&acpi_idle_driver);
1479 return retval;
1480 }
1481 acpi_processor_registered++;
1482 }
1483 return 0;
1484 }
1485
1486 int acpi_processor_power_exit(struct acpi_processor *pr)
1487 {
1488 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1489
1490 if (disabled_by_idle_boot_param())
1491 return 0;
1492
1493 if (pr->flags.power) {
1494 cpuidle_unregister_device(dev);
1495 acpi_processor_registered--;
1496 if (acpi_processor_registered == 0)
1497 cpuidle_unregister_driver(&acpi_idle_driver);
1498 }
1499
1500 pr->flags.power_setup_done = 0;
1501 return 0;
1502 }
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