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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
36ACPI_MODULE_NAME("processor_idle");
37
38#define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
39
40static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
41module_param(max_cstate, uint, 0000);
42static unsigned int nocst __read_mostly;
43module_param(nocst, uint, 0000);
44static int bm_check_disable __read_mostly;
45module_param(bm_check_disable, uint, 0000);
46
47static unsigned int latency_factor __read_mostly = 2;
48module_param(latency_factor, uint, 0644);
49
50static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
51
52struct cpuidle_driver acpi_idle_driver = {
53 .name = "acpi_idle",
54 .owner = THIS_MODULE,
55};
56
57#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
58static
59DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
60
61static 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 */
73static 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
87static 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 */
108static 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 */
124static 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
147static 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
157static 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 */
164static 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
180static void lapic_timer_check_state(int state, struct acpi_processor *pr,
181 struct acpi_processor_cx *cstate) { }
182static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
183static 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)
192static 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
215static void tsc_check_state(int state) { return; }
216#endif
217
218static 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
283static 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
300static 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
462static 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
543static 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
581static 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 */
622static 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/**
646 * acpi_idle_do_entry - enter idle state using the appropriate method
647 * @cx: cstate data
648 *
649 * Caller disables interrupt before call and enables interrupt after return.
650 */
651static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
652{
653 if (cx->entry_method == ACPI_CSTATE_FFH) {
654 /* Call into architectural FFH based C-state */
655 acpi_processor_ffh_cstate_enter(cx);
656 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
657 acpi_safe_halt();
658 } else {
659 /* IO port based C-state */
660 inb(cx->address);
661 /* Dummy wait op - must do something useless after P_LVL2 read
662 because chipsets cannot guarantee that STPCLK# signal
663 gets asserted in time to freeze execution properly. */
664 inl(acpi_gbl_FADT.xpm_timer_block.address);
665 }
666}
667
668/**
669 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
670 * @dev: the target CPU
671 * @index: the index of suggested state
672 */
673static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
674{
675 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
676
677 ACPI_FLUSH_CPU_CACHE();
678
679 while (1) {
680
681 if (cx->entry_method == ACPI_CSTATE_HALT)
682 safe_halt();
683 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
684 inb(cx->address);
685 /* See comment in acpi_idle_do_entry() */
686 inl(acpi_gbl_FADT.xpm_timer_block.address);
687 } else
688 return -ENODEV;
689 }
690
691 /* Never reached */
692 return 0;
693}
694
695static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
696{
697 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
698 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
699}
700
701static int c3_cpu_count;
702static DEFINE_RAW_SPINLOCK(c3_lock);
703
704/**
705 * acpi_idle_enter_bm - enters C3 with proper BM handling
706 * @pr: Target processor
707 * @cx: Target state context
708 * @timer_bc: Whether or not to change timer mode to broadcast
709 */
710static void acpi_idle_enter_bm(struct acpi_processor *pr,
711 struct acpi_processor_cx *cx, bool timer_bc)
712{
713 acpi_unlazy_tlb(smp_processor_id());
714
715 /*
716 * Must be done before busmaster disable as we might need to
717 * access HPET !
718 */
719 if (timer_bc)
720 lapic_timer_state_broadcast(pr, cx, 1);
721
722 /*
723 * disable bus master
724 * bm_check implies we need ARB_DIS
725 * bm_control implies whether we can do ARB_DIS
726 *
727 * That leaves a case where bm_check is set and bm_control is
728 * not set. In that case we cannot do much, we enter C3
729 * without doing anything.
730 */
731 if (pr->flags.bm_control) {
732 raw_spin_lock(&c3_lock);
733 c3_cpu_count++;
734 /* Disable bus master arbitration when all CPUs are in C3 */
735 if (c3_cpu_count == num_online_cpus())
736 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
737 raw_spin_unlock(&c3_lock);
738 }
739
740 acpi_idle_do_entry(cx);
741
742 /* Re-enable bus master arbitration */
743 if (pr->flags.bm_control) {
744 raw_spin_lock(&c3_lock);
745 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
746 c3_cpu_count--;
747 raw_spin_unlock(&c3_lock);
748 }
749
750 if (timer_bc)
751 lapic_timer_state_broadcast(pr, cx, 0);
752}
753
754static int acpi_idle_enter(struct cpuidle_device *dev,
755 struct cpuidle_driver *drv, int index)
756{
757 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
758 struct acpi_processor *pr;
759
760 pr = __this_cpu_read(processors);
761 if (unlikely(!pr))
762 return -EINVAL;
763
764 if (cx->type != ACPI_STATE_C1) {
765 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
766 index = ACPI_IDLE_STATE_START;
767 cx = per_cpu(acpi_cstate[index], dev->cpu);
768 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
769 if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
770 acpi_idle_enter_bm(pr, cx, true);
771 return index;
772 } else if (drv->safe_state_index >= 0) {
773 index = drv->safe_state_index;
774 cx = per_cpu(acpi_cstate[index], dev->cpu);
775 } else {
776 acpi_safe_halt();
777 return -EBUSY;
778 }
779 }
780 }
781
782 lapic_timer_state_broadcast(pr, cx, 1);
783
784 if (cx->type == ACPI_STATE_C3)
785 ACPI_FLUSH_CPU_CACHE();
786
787 acpi_idle_do_entry(cx);
788
789 lapic_timer_state_broadcast(pr, cx, 0);
790
791 return index;
792}
793
794static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
795 struct cpuidle_driver *drv, int index)
796{
797 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
798
799 if (cx->type == ACPI_STATE_C3) {
800 struct acpi_processor *pr = __this_cpu_read(processors);
801
802 if (unlikely(!pr))
803 return;
804
805 if (pr->flags.bm_check) {
806 acpi_idle_enter_bm(pr, cx, false);
807 return;
808 } else {
809 ACPI_FLUSH_CPU_CACHE();
810 }
811 }
812 acpi_idle_do_entry(cx);
813}
814
815static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
816 struct cpuidle_device *dev)
817{
818 int i, count = ACPI_IDLE_STATE_START;
819 struct acpi_processor_cx *cx;
820
821 if (max_cstate == 0)
822 max_cstate = 1;
823
824 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
825 cx = &pr->power.states[i];
826
827 if (!cx->valid)
828 continue;
829
830 per_cpu(acpi_cstate[count], dev->cpu) = cx;
831
832 count++;
833 if (count == CPUIDLE_STATE_MAX)
834 break;
835 }
836
837 if (!count)
838 return -EINVAL;
839
840 return 0;
841}
842
843static int acpi_processor_setup_cstates(struct acpi_processor *pr)
844{
845 int i, count;
846 struct acpi_processor_cx *cx;
847 struct cpuidle_state *state;
848 struct cpuidle_driver *drv = &acpi_idle_driver;
849
850 if (max_cstate == 0)
851 max_cstate = 1;
852
853 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
854 cpuidle_poll_state_init(drv);
855 count = 1;
856 } else {
857 count = 0;
858 }
859
860 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
861 cx = &pr->power.states[i];
862
863 if (!cx->valid)
864 continue;
865
866 state = &drv->states[count];
867 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
868 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
869 state->exit_latency = cx->latency;
870 state->target_residency = cx->latency * latency_factor;
871 state->enter = acpi_idle_enter;
872
873 state->flags = 0;
874 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
875 state->enter_dead = acpi_idle_play_dead;
876 drv->safe_state_index = count;
877 }
878 /*
879 * Halt-induced C1 is not good for ->enter_s2idle, because it
880 * re-enables interrupts on exit. Moreover, C1 is generally not
881 * particularly interesting from the suspend-to-idle angle, so
882 * avoid C1 and the situations in which we may need to fall back
883 * to it altogether.
884 */
885 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
886 state->enter_s2idle = acpi_idle_enter_s2idle;
887
888 count++;
889 if (count == CPUIDLE_STATE_MAX)
890 break;
891 }
892
893 drv->state_count = count;
894
895 if (!count)
896 return -EINVAL;
897
898 return 0;
899}
900
901static inline void acpi_processor_cstate_first_run_checks(void)
902{
903 acpi_status status;
904 static int first_run;
905
906 if (first_run)
907 return;
908 dmi_check_system(processor_power_dmi_table);
909 max_cstate = acpi_processor_cstate_check(max_cstate);
910 if (max_cstate < ACPI_C_STATES_MAX)
911 pr_notice("ACPI: processor limited to max C-state %d\n",
912 max_cstate);
913 first_run++;
914
915 if (acpi_gbl_FADT.cst_control && !nocst) {
916 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
917 acpi_gbl_FADT.cst_control, 8);
918 if (ACPI_FAILURE(status))
919 ACPI_EXCEPTION((AE_INFO, status,
920 "Notifying BIOS of _CST ability failed"));
921 }
922}
923#else
924
925static inline int disabled_by_idle_boot_param(void) { return 0; }
926static inline void acpi_processor_cstate_first_run_checks(void) { }
927static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
928{
929 return -ENODEV;
930}
931
932static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
933 struct cpuidle_device *dev)
934{
935 return -EINVAL;
936}
937
938static int acpi_processor_setup_cstates(struct acpi_processor *pr)
939{
940 return -EINVAL;
941}
942
943#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
944
945struct acpi_lpi_states_array {
946 unsigned int size;
947 unsigned int composite_states_size;
948 struct acpi_lpi_state *entries;
949 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
950};
951
952static int obj_get_integer(union acpi_object *obj, u32 *value)
953{
954 if (obj->type != ACPI_TYPE_INTEGER)
955 return -EINVAL;
956
957 *value = obj->integer.value;
958 return 0;
959}
960
961static int acpi_processor_evaluate_lpi(acpi_handle handle,
962 struct acpi_lpi_states_array *info)
963{
964 acpi_status status;
965 int ret = 0;
966 int pkg_count, state_idx = 1, loop;
967 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
968 union acpi_object *lpi_data;
969 struct acpi_lpi_state *lpi_state;
970
971 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
972 if (ACPI_FAILURE(status)) {
973 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
974 return -ENODEV;
975 }
976
977 lpi_data = buffer.pointer;
978
979 /* There must be at least 4 elements = 3 elements + 1 package */
980 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
981 lpi_data->package.count < 4) {
982 pr_debug("not enough elements in _LPI\n");
983 ret = -ENODATA;
984 goto end;
985 }
986
987 pkg_count = lpi_data->package.elements[2].integer.value;
988
989 /* Validate number of power states. */
990 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
991 pr_debug("count given by _LPI is not valid\n");
992 ret = -ENODATA;
993 goto end;
994 }
995
996 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
997 if (!lpi_state) {
998 ret = -ENOMEM;
999 goto end;
1000 }
1001
1002 info->size = pkg_count;
1003 info->entries = lpi_state;
1004
1005 /* LPI States start at index 3 */
1006 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1007 union acpi_object *element, *pkg_elem, *obj;
1008
1009 element = &lpi_data->package.elements[loop];
1010 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1011 continue;
1012
1013 pkg_elem = element->package.elements;
1014
1015 obj = pkg_elem + 6;
1016 if (obj->type == ACPI_TYPE_BUFFER) {
1017 struct acpi_power_register *reg;
1018
1019 reg = (struct acpi_power_register *)obj->buffer.pointer;
1020 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1021 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1022 continue;
1023
1024 lpi_state->address = reg->address;
1025 lpi_state->entry_method =
1026 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1027 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1028 } else if (obj->type == ACPI_TYPE_INTEGER) {
1029 lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1030 lpi_state->address = obj->integer.value;
1031 } else {
1032 continue;
1033 }
1034
1035 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1036
1037 obj = pkg_elem + 9;
1038 if (obj->type == ACPI_TYPE_STRING)
1039 strlcpy(lpi_state->desc, obj->string.pointer,
1040 ACPI_CX_DESC_LEN);
1041
1042 lpi_state->index = state_idx;
1043 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1044 pr_debug("No min. residency found, assuming 10 us\n");
1045 lpi_state->min_residency = 10;
1046 }
1047
1048 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1049 pr_debug("No wakeup residency found, assuming 10 us\n");
1050 lpi_state->wake_latency = 10;
1051 }
1052
1053 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1054 lpi_state->flags = 0;
1055
1056 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1057 lpi_state->arch_flags = 0;
1058
1059 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1060 lpi_state->res_cnt_freq = 1;
1061
1062 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1063 lpi_state->enable_parent_state = 0;
1064 }
1065
1066 acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1067end:
1068 kfree(buffer.pointer);
1069 return ret;
1070}
1071
1072/*
1073 * flat_state_cnt - the number of composite LPI states after the process of flattening
1074 */
1075static int flat_state_cnt;
1076
1077/**
1078 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1079 *
1080 * @local: local LPI state
1081 * @parent: parent LPI state
1082 * @result: composite LPI state
1083 */
1084static bool combine_lpi_states(struct acpi_lpi_state *local,
1085 struct acpi_lpi_state *parent,
1086 struct acpi_lpi_state *result)
1087{
1088 if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1089 if (!parent->address) /* 0 means autopromotable */
1090 return false;
1091 result->address = local->address + parent->address;
1092 } else {
1093 result->address = parent->address;
1094 }
1095
1096 result->min_residency = max(local->min_residency, parent->min_residency);
1097 result->wake_latency = local->wake_latency + parent->wake_latency;
1098 result->enable_parent_state = parent->enable_parent_state;
1099 result->entry_method = local->entry_method;
1100
1101 result->flags = parent->flags;
1102 result->arch_flags = parent->arch_flags;
1103 result->index = parent->index;
1104
1105 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1106 strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1107 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1108 return true;
1109}
1110
1111#define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0)
1112
1113static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1114 struct acpi_lpi_state *t)
1115{
1116 curr_level->composite_states[curr_level->composite_states_size++] = t;
1117}
1118
1119static int flatten_lpi_states(struct acpi_processor *pr,
1120 struct acpi_lpi_states_array *curr_level,
1121 struct acpi_lpi_states_array *prev_level)
1122{
1123 int i, j, state_count = curr_level->size;
1124 struct acpi_lpi_state *p, *t = curr_level->entries;
1125
1126 curr_level->composite_states_size = 0;
1127 for (j = 0; j < state_count; j++, t++) {
1128 struct acpi_lpi_state *flpi;
1129
1130 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1131 continue;
1132
1133 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1134 pr_warn("Limiting number of LPI states to max (%d)\n",
1135 ACPI_PROCESSOR_MAX_POWER);
1136 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1137 break;
1138 }
1139
1140 flpi = &pr->power.lpi_states[flat_state_cnt];
1141
1142 if (!prev_level) { /* leaf/processor node */
1143 memcpy(flpi, t, sizeof(*t));
1144 stash_composite_state(curr_level, flpi);
1145 flat_state_cnt++;
1146 continue;
1147 }
1148
1149 for (i = 0; i < prev_level->composite_states_size; i++) {
1150 p = prev_level->composite_states[i];
1151 if (t->index <= p->enable_parent_state &&
1152 combine_lpi_states(p, t, flpi)) {
1153 stash_composite_state(curr_level, flpi);
1154 flat_state_cnt++;
1155 flpi++;
1156 }
1157 }
1158 }
1159
1160 kfree(curr_level->entries);
1161 return 0;
1162}
1163
1164static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1165{
1166 int ret, i;
1167 acpi_status status;
1168 acpi_handle handle = pr->handle, pr_ahandle;
1169 struct acpi_device *d = NULL;
1170 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1171
1172 if (!osc_pc_lpi_support_confirmed)
1173 return -EOPNOTSUPP;
1174
1175 if (!acpi_has_method(handle, "_LPI"))
1176 return -EINVAL;
1177
1178 flat_state_cnt = 0;
1179 prev = &info[0];
1180 curr = &info[1];
1181 handle = pr->handle;
1182 ret = acpi_processor_evaluate_lpi(handle, prev);
1183 if (ret)
1184 return ret;
1185 flatten_lpi_states(pr, prev, NULL);
1186
1187 status = acpi_get_parent(handle, &pr_ahandle);
1188 while (ACPI_SUCCESS(status)) {
1189 acpi_bus_get_device(pr_ahandle, &d);
1190 handle = pr_ahandle;
1191
1192 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1193 break;
1194
1195 /* can be optional ? */
1196 if (!acpi_has_method(handle, "_LPI"))
1197 break;
1198
1199 ret = acpi_processor_evaluate_lpi(handle, curr);
1200 if (ret)
1201 break;
1202
1203 /* flatten all the LPI states in this level of hierarchy */
1204 flatten_lpi_states(pr, curr, prev);
1205
1206 tmp = prev, prev = curr, curr = tmp;
1207
1208 status = acpi_get_parent(handle, &pr_ahandle);
1209 }
1210
1211 pr->power.count = flat_state_cnt;
1212 /* reset the index after flattening */
1213 for (i = 0; i < pr->power.count; i++)
1214 pr->power.lpi_states[i].index = i;
1215
1216 /* Tell driver that _LPI is supported. */
1217 pr->flags.has_lpi = 1;
1218 pr->flags.power = 1;
1219
1220 return 0;
1221}
1222
1223int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1224{
1225 return -ENODEV;
1226}
1227
1228int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1229{
1230 return -ENODEV;
1231}
1232
1233/**
1234 * acpi_idle_lpi_enter - enters an ACPI any LPI state
1235 * @dev: the target CPU
1236 * @drv: cpuidle driver containing cpuidle state info
1237 * @index: index of target state
1238 *
1239 * Return: 0 for success or negative value for error
1240 */
1241static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1242 struct cpuidle_driver *drv, int index)
1243{
1244 struct acpi_processor *pr;
1245 struct acpi_lpi_state *lpi;
1246
1247 pr = __this_cpu_read(processors);
1248
1249 if (unlikely(!pr))
1250 return -EINVAL;
1251
1252 lpi = &pr->power.lpi_states[index];
1253 if (lpi->entry_method == ACPI_CSTATE_FFH)
1254 return acpi_processor_ffh_lpi_enter(lpi);
1255
1256 return -EINVAL;
1257}
1258
1259static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1260{
1261 int i;
1262 struct acpi_lpi_state *lpi;
1263 struct cpuidle_state *state;
1264 struct cpuidle_driver *drv = &acpi_idle_driver;
1265
1266 if (!pr->flags.has_lpi)
1267 return -EOPNOTSUPP;
1268
1269 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1270 lpi = &pr->power.lpi_states[i];
1271
1272 state = &drv->states[i];
1273 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1274 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1275 state->exit_latency = lpi->wake_latency;
1276 state->target_residency = lpi->min_residency;
1277 if (lpi->arch_flags)
1278 state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1279 state->enter = acpi_idle_lpi_enter;
1280 drv->safe_state_index = i;
1281 }
1282
1283 drv->state_count = i;
1284
1285 return 0;
1286}
1287
1288/**
1289 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1290 * global state data i.e. idle routines
1291 *
1292 * @pr: the ACPI processor
1293 */
1294static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1295{
1296 int i;
1297 struct cpuidle_driver *drv = &acpi_idle_driver;
1298
1299 if (!pr->flags.power_setup_done || !pr->flags.power)
1300 return -EINVAL;
1301
1302 drv->safe_state_index = -1;
1303 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1304 drv->states[i].name[0] = '\0';
1305 drv->states[i].desc[0] = '\0';
1306 }
1307
1308 if (pr->flags.has_lpi)
1309 return acpi_processor_setup_lpi_states(pr);
1310
1311 return acpi_processor_setup_cstates(pr);
1312}
1313
1314/**
1315 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1316 * device i.e. per-cpu data
1317 *
1318 * @pr: the ACPI processor
1319 * @dev : the cpuidle device
1320 */
1321static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1322 struct cpuidle_device *dev)
1323{
1324 if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1325 return -EINVAL;
1326
1327 dev->cpu = pr->id;
1328 if (pr->flags.has_lpi)
1329 return acpi_processor_ffh_lpi_probe(pr->id);
1330
1331 return acpi_processor_setup_cpuidle_cx(pr, dev);
1332}
1333
1334static int acpi_processor_get_power_info(struct acpi_processor *pr)
1335{
1336 int ret;
1337
1338 ret = acpi_processor_get_lpi_info(pr);
1339 if (ret)
1340 ret = acpi_processor_get_cstate_info(pr);
1341
1342 return ret;
1343}
1344
1345int acpi_processor_hotplug(struct acpi_processor *pr)
1346{
1347 int ret = 0;
1348 struct cpuidle_device *dev;
1349
1350 if (disabled_by_idle_boot_param())
1351 return 0;
1352
1353 if (!pr->flags.power_setup_done)
1354 return -ENODEV;
1355
1356 dev = per_cpu(acpi_cpuidle_device, pr->id);
1357 cpuidle_pause_and_lock();
1358 cpuidle_disable_device(dev);
1359 ret = acpi_processor_get_power_info(pr);
1360 if (!ret && pr->flags.power) {
1361 acpi_processor_setup_cpuidle_dev(pr, dev);
1362 ret = cpuidle_enable_device(dev);
1363 }
1364 cpuidle_resume_and_unlock();
1365
1366 return ret;
1367}
1368
1369int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1370{
1371 int cpu;
1372 struct acpi_processor *_pr;
1373 struct cpuidle_device *dev;
1374
1375 if (disabled_by_idle_boot_param())
1376 return 0;
1377
1378 if (!pr->flags.power_setup_done)
1379 return -ENODEV;
1380
1381 /*
1382 * FIXME: Design the ACPI notification to make it once per
1383 * system instead of once per-cpu. This condition is a hack
1384 * to make the code that updates C-States be called once.
1385 */
1386
1387 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1388
1389 /* Protect against cpu-hotplug */
1390 get_online_cpus();
1391 cpuidle_pause_and_lock();
1392
1393 /* Disable all cpuidle devices */
1394 for_each_online_cpu(cpu) {
1395 _pr = per_cpu(processors, cpu);
1396 if (!_pr || !_pr->flags.power_setup_done)
1397 continue;
1398 dev = per_cpu(acpi_cpuidle_device, cpu);
1399 cpuidle_disable_device(dev);
1400 }
1401
1402 /* Populate Updated C-state information */
1403 acpi_processor_get_power_info(pr);
1404 acpi_processor_setup_cpuidle_states(pr);
1405
1406 /* Enable all cpuidle devices */
1407 for_each_online_cpu(cpu) {
1408 _pr = per_cpu(processors, cpu);
1409 if (!_pr || !_pr->flags.power_setup_done)
1410 continue;
1411 acpi_processor_get_power_info(_pr);
1412 if (_pr->flags.power) {
1413 dev = per_cpu(acpi_cpuidle_device, cpu);
1414 acpi_processor_setup_cpuidle_dev(_pr, dev);
1415 cpuidle_enable_device(dev);
1416 }
1417 }
1418 cpuidle_resume_and_unlock();
1419 put_online_cpus();
1420 }
1421
1422 return 0;
1423}
1424
1425static int acpi_processor_registered;
1426
1427int acpi_processor_power_init(struct acpi_processor *pr)
1428{
1429 int retval;
1430 struct cpuidle_device *dev;
1431
1432 if (disabled_by_idle_boot_param())
1433 return 0;
1434
1435 acpi_processor_cstate_first_run_checks();
1436
1437 if (!acpi_processor_get_power_info(pr))
1438 pr->flags.power_setup_done = 1;
1439
1440 /*
1441 * Install the idle handler if processor power management is supported.
1442 * Note that we use previously set idle handler will be used on
1443 * platforms that only support C1.
1444 */
1445 if (pr->flags.power) {
1446 /* Register acpi_idle_driver if not already registered */
1447 if (!acpi_processor_registered) {
1448 acpi_processor_setup_cpuidle_states(pr);
1449 retval = cpuidle_register_driver(&acpi_idle_driver);
1450 if (retval)
1451 return retval;
1452 pr_debug("%s registered with cpuidle\n",
1453 acpi_idle_driver.name);
1454 }
1455
1456 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1457 if (!dev)
1458 return -ENOMEM;
1459 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1460
1461 acpi_processor_setup_cpuidle_dev(pr, dev);
1462
1463 /* Register per-cpu cpuidle_device. Cpuidle driver
1464 * must already be registered before registering device
1465 */
1466 retval = cpuidle_register_device(dev);
1467 if (retval) {
1468 if (acpi_processor_registered == 0)
1469 cpuidle_unregister_driver(&acpi_idle_driver);
1470 return retval;
1471 }
1472 acpi_processor_registered++;
1473 }
1474 return 0;
1475}
1476
1477int acpi_processor_power_exit(struct acpi_processor *pr)
1478{
1479 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1480
1481 if (disabled_by_idle_boot_param())
1482 return 0;
1483
1484 if (pr->flags.power) {
1485 cpuidle_unregister_device(dev);
1486 acpi_processor_registered--;
1487 if (acpi_processor_registered == 0)
1488 cpuidle_unregister_driver(&acpi_idle_driver);
1489 }
1490
1491 pr->flags.power_setup_done = 0;
1492 return 0;
1493}
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 <acpi/processor.h>
35
36/*
37 * Include the apic definitions for x86 to have the APIC timer related defines
38 * available also for UP (on SMP it gets magically included via linux/smp.h).
39 * asm/acpi.h is not an option, as it would require more include magic. Also
40 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
41 */
42#ifdef CONFIG_X86
43#include <asm/apic.h>
44#endif
45
46#define ACPI_PROCESSOR_CLASS "processor"
47#define _COMPONENT ACPI_PROCESSOR_COMPONENT
48ACPI_MODULE_NAME("processor_idle");
49
50static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
51module_param(max_cstate, uint, 0000);
52static unsigned int nocst __read_mostly;
53module_param(nocst, uint, 0000);
54static int bm_check_disable __read_mostly;
55module_param(bm_check_disable, uint, 0000);
56
57static unsigned int latency_factor __read_mostly = 2;
58module_param(latency_factor, uint, 0644);
59
60static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
61
62static
63DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
64
65static int disabled_by_idle_boot_param(void)
66{
67 return boot_option_idle_override == IDLE_POLL ||
68 boot_option_idle_override == IDLE_HALT;
69}
70
71/*
72 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
73 * For now disable this. Probably a bug somewhere else.
74 *
75 * To skip this limit, boot/load with a large max_cstate limit.
76 */
77static int set_max_cstate(const struct dmi_system_id *id)
78{
79 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
80 return 0;
81
82 pr_notice("%s detected - limiting to C%ld max_cstate."
83 " Override with \"processor.max_cstate=%d\"\n", id->ident,
84 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
85
86 max_cstate = (long)id->driver_data;
87
88 return 0;
89}
90
91static const struct dmi_system_id processor_power_dmi_table[] = {
92 { set_max_cstate, "Clevo 5600D", {
93 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
94 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
95 (void *)2},
96 { set_max_cstate, "Pavilion zv5000", {
97 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
98 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
99 (void *)1},
100 { set_max_cstate, "Asus L8400B", {
101 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
102 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
103 (void *)1},
104 {},
105};
106
107
108/*
109 * Callers should disable interrupts before the call and enable
110 * interrupts after return.
111 */
112static void acpi_safe_halt(void)
113{
114 if (!tif_need_resched()) {
115 safe_halt();
116 local_irq_disable();
117 }
118}
119
120#ifdef ARCH_APICTIMER_STOPS_ON_C3
121
122/*
123 * Some BIOS implementations switch to C3 in the published C2 state.
124 * This seems to be a common problem on AMD boxen, but other vendors
125 * are affected too. We pick the most conservative approach: we assume
126 * that the local APIC stops in both C2 and C3.
127 */
128static void lapic_timer_check_state(int state, struct acpi_processor *pr,
129 struct acpi_processor_cx *cx)
130{
131 struct acpi_processor_power *pwr = &pr->power;
132 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
133
134 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
135 return;
136
137 if (amd_e400_c1e_detected)
138 type = ACPI_STATE_C1;
139
140 /*
141 * Check, if one of the previous states already marked the lapic
142 * unstable
143 */
144 if (pwr->timer_broadcast_on_state < state)
145 return;
146
147 if (cx->type >= type)
148 pr->power.timer_broadcast_on_state = state;
149}
150
151static void __lapic_timer_propagate_broadcast(void *arg)
152{
153 struct acpi_processor *pr = (struct acpi_processor *) arg;
154
155 if (pr->power.timer_broadcast_on_state < INT_MAX)
156 tick_broadcast_enable();
157 else
158 tick_broadcast_disable();
159}
160
161static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
162{
163 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
164 (void *)pr, 1);
165}
166
167/* Power(C) State timer broadcast control */
168static void lapic_timer_state_broadcast(struct acpi_processor *pr,
169 struct acpi_processor_cx *cx,
170 int broadcast)
171{
172 int state = cx - pr->power.states;
173
174 if (state >= pr->power.timer_broadcast_on_state) {
175 if (broadcast)
176 tick_broadcast_enter();
177 else
178 tick_broadcast_exit();
179 }
180}
181
182#else
183
184static void lapic_timer_check_state(int state, struct acpi_processor *pr,
185 struct acpi_processor_cx *cstate) { }
186static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
187static void lapic_timer_state_broadcast(struct acpi_processor *pr,
188 struct acpi_processor_cx *cx,
189 int broadcast)
190{
191}
192
193#endif
194
195#if defined(CONFIG_X86)
196static void tsc_check_state(int state)
197{
198 switch (boot_cpu_data.x86_vendor) {
199 case X86_VENDOR_AMD:
200 case X86_VENDOR_INTEL:
201 /*
202 * AMD Fam10h TSC will tick in all
203 * C/P/S0/S1 states when this bit is set.
204 */
205 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
206 return;
207
208 /*FALL THROUGH*/
209 default:
210 /* TSC could halt in idle, so notify users */
211 if (state > ACPI_STATE_C1)
212 mark_tsc_unstable("TSC halts in idle");
213 }
214}
215#else
216static void tsc_check_state(int state) { return; }
217#endif
218
219static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
220{
221
222 if (!pr->pblk)
223 return -ENODEV;
224
225 /* if info is obtained from pblk/fadt, type equals state */
226 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
227 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
228
229#ifndef CONFIG_HOTPLUG_CPU
230 /*
231 * Check for P_LVL2_UP flag before entering C2 and above on
232 * an SMP system.
233 */
234 if ((num_online_cpus() > 1) &&
235 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
236 return -ENODEV;
237#endif
238
239 /* determine C2 and C3 address from pblk */
240 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
241 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
242
243 /* determine latencies from FADT */
244 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
245 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
246
247 /*
248 * FADT specified C2 latency must be less than or equal to
249 * 100 microseconds.
250 */
251 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
252 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
253 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
254 /* invalidate C2 */
255 pr->power.states[ACPI_STATE_C2].address = 0;
256 }
257
258 /*
259 * FADT supplied C3 latency must be less than or equal to
260 * 1000 microseconds.
261 */
262 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
263 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
264 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
265 /* invalidate C3 */
266 pr->power.states[ACPI_STATE_C3].address = 0;
267 }
268
269 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
270 "lvl2[0x%08x] lvl3[0x%08x]\n",
271 pr->power.states[ACPI_STATE_C2].address,
272 pr->power.states[ACPI_STATE_C3].address));
273
274 return 0;
275}
276
277static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
278{
279 if (!pr->power.states[ACPI_STATE_C1].valid) {
280 /* set the first C-State to C1 */
281 /* all processors need to support C1 */
282 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
283 pr->power.states[ACPI_STATE_C1].valid = 1;
284 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
285 }
286 /* the C0 state only exists as a filler in our array */
287 pr->power.states[ACPI_STATE_C0].valid = 1;
288 return 0;
289}
290
291static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
292{
293 acpi_status status;
294 u64 count;
295 int current_count;
296 int i, ret = 0;
297 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
298 union acpi_object *cst;
299
300
301 if (nocst)
302 return -ENODEV;
303
304 current_count = 0;
305
306 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
307 if (ACPI_FAILURE(status)) {
308 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
309 return -ENODEV;
310 }
311
312 cst = buffer.pointer;
313
314 /* There must be at least 2 elements */
315 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
316 pr_err("not enough elements in _CST\n");
317 ret = -EFAULT;
318 goto end;
319 }
320
321 count = cst->package.elements[0].integer.value;
322
323 /* Validate number of power states. */
324 if (count < 1 || count != cst->package.count - 1) {
325 pr_err("count given by _CST is not valid\n");
326 ret = -EFAULT;
327 goto end;
328 }
329
330 /* Tell driver that at least _CST is supported. */
331 pr->flags.has_cst = 1;
332
333 for (i = 1; i <= count; i++) {
334 union acpi_object *element;
335 union acpi_object *obj;
336 struct acpi_power_register *reg;
337 struct acpi_processor_cx cx;
338
339 memset(&cx, 0, sizeof(cx));
340
341 element = &(cst->package.elements[i]);
342 if (element->type != ACPI_TYPE_PACKAGE)
343 continue;
344
345 if (element->package.count != 4)
346 continue;
347
348 obj = &(element->package.elements[0]);
349
350 if (obj->type != ACPI_TYPE_BUFFER)
351 continue;
352
353 reg = (struct acpi_power_register *)obj->buffer.pointer;
354
355 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
356 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
357 continue;
358
359 /* There should be an easy way to extract an integer... */
360 obj = &(element->package.elements[1]);
361 if (obj->type != ACPI_TYPE_INTEGER)
362 continue;
363
364 cx.type = obj->integer.value;
365 /*
366 * Some buggy BIOSes won't list C1 in _CST -
367 * Let acpi_processor_get_power_info_default() handle them later
368 */
369 if (i == 1 && cx.type != ACPI_STATE_C1)
370 current_count++;
371
372 cx.address = reg->address;
373 cx.index = current_count + 1;
374
375 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
376 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
377 if (acpi_processor_ffh_cstate_probe
378 (pr->id, &cx, reg) == 0) {
379 cx.entry_method = ACPI_CSTATE_FFH;
380 } else if (cx.type == ACPI_STATE_C1) {
381 /*
382 * C1 is a special case where FIXED_HARDWARE
383 * can be handled in non-MWAIT way as well.
384 * In that case, save this _CST entry info.
385 * Otherwise, ignore this info and continue.
386 */
387 cx.entry_method = ACPI_CSTATE_HALT;
388 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
389 } else {
390 continue;
391 }
392 if (cx.type == ACPI_STATE_C1 &&
393 (boot_option_idle_override == IDLE_NOMWAIT)) {
394 /*
395 * In most cases the C1 space_id obtained from
396 * _CST object is FIXED_HARDWARE access mode.
397 * But when the option of idle=halt is added,
398 * the entry_method type should be changed from
399 * CSTATE_FFH to CSTATE_HALT.
400 * When the option of idle=nomwait is added,
401 * the C1 entry_method type should be
402 * CSTATE_HALT.
403 */
404 cx.entry_method = ACPI_CSTATE_HALT;
405 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
406 }
407 } else {
408 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
409 cx.address);
410 }
411
412 if (cx.type == ACPI_STATE_C1) {
413 cx.valid = 1;
414 }
415
416 obj = &(element->package.elements[2]);
417 if (obj->type != ACPI_TYPE_INTEGER)
418 continue;
419
420 cx.latency = obj->integer.value;
421
422 obj = &(element->package.elements[3]);
423 if (obj->type != ACPI_TYPE_INTEGER)
424 continue;
425
426 current_count++;
427 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
428
429 /*
430 * We support total ACPI_PROCESSOR_MAX_POWER - 1
431 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
432 */
433 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
434 pr_warn("Limiting number of power states to max (%d)\n",
435 ACPI_PROCESSOR_MAX_POWER);
436 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
437 break;
438 }
439 }
440
441 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
442 current_count));
443
444 /* Validate number of power states discovered */
445 if (current_count < 2)
446 ret = -EFAULT;
447
448 end:
449 kfree(buffer.pointer);
450
451 return ret;
452}
453
454static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
455 struct acpi_processor_cx *cx)
456{
457 static int bm_check_flag = -1;
458 static int bm_control_flag = -1;
459
460
461 if (!cx->address)
462 return;
463
464 /*
465 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
466 * DMA transfers are used by any ISA device to avoid livelock.
467 * Note that we could disable Type-F DMA (as recommended by
468 * the erratum), but this is known to disrupt certain ISA
469 * devices thus we take the conservative approach.
470 */
471 else if (errata.piix4.fdma) {
472 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
473 "C3 not supported on PIIX4 with Type-F DMA\n"));
474 return;
475 }
476
477 /* All the logic here assumes flags.bm_check is same across all CPUs */
478 if (bm_check_flag == -1) {
479 /* Determine whether bm_check is needed based on CPU */
480 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
481 bm_check_flag = pr->flags.bm_check;
482 bm_control_flag = pr->flags.bm_control;
483 } else {
484 pr->flags.bm_check = bm_check_flag;
485 pr->flags.bm_control = bm_control_flag;
486 }
487
488 if (pr->flags.bm_check) {
489 if (!pr->flags.bm_control) {
490 if (pr->flags.has_cst != 1) {
491 /* bus mastering control is necessary */
492 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
493 "C3 support requires BM control\n"));
494 return;
495 } else {
496 /* Here we enter C3 without bus mastering */
497 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
498 "C3 support without BM control\n"));
499 }
500 }
501 } else {
502 /*
503 * WBINVD should be set in fadt, for C3 state to be
504 * supported on when bm_check is not required.
505 */
506 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
507 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
508 "Cache invalidation should work properly"
509 " for C3 to be enabled on SMP systems\n"));
510 return;
511 }
512 }
513
514 /*
515 * Otherwise we've met all of our C3 requirements.
516 * Normalize the C3 latency to expidite policy. Enable
517 * checking of bus mastering status (bm_check) so we can
518 * use this in our C3 policy
519 */
520 cx->valid = 1;
521
522 /*
523 * On older chipsets, BM_RLD needs to be set
524 * in order for Bus Master activity to wake the
525 * system from C3. Newer chipsets handle DMA
526 * during C3 automatically and BM_RLD is a NOP.
527 * In either case, the proper way to
528 * handle BM_RLD is to set it and leave it set.
529 */
530 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
531
532 return;
533}
534
535static int acpi_processor_power_verify(struct acpi_processor *pr)
536{
537 unsigned int i;
538 unsigned int working = 0;
539
540 pr->power.timer_broadcast_on_state = INT_MAX;
541
542 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
543 struct acpi_processor_cx *cx = &pr->power.states[i];
544
545 switch (cx->type) {
546 case ACPI_STATE_C1:
547 cx->valid = 1;
548 break;
549
550 case ACPI_STATE_C2:
551 if (!cx->address)
552 break;
553 cx->valid = 1;
554 break;
555
556 case ACPI_STATE_C3:
557 acpi_processor_power_verify_c3(pr, cx);
558 break;
559 }
560 if (!cx->valid)
561 continue;
562
563 lapic_timer_check_state(i, pr, cx);
564 tsc_check_state(cx->type);
565 working++;
566 }
567
568 lapic_timer_propagate_broadcast(pr);
569
570 return (working);
571}
572
573static int acpi_processor_get_power_info(struct acpi_processor *pr)
574{
575 unsigned int i;
576 int result;
577
578
579 /* NOTE: the idle thread may not be running while calling
580 * this function */
581
582 /* Zero initialize all the C-states info. */
583 memset(pr->power.states, 0, sizeof(pr->power.states));
584
585 result = acpi_processor_get_power_info_cst(pr);
586 if (result == -ENODEV)
587 result = acpi_processor_get_power_info_fadt(pr);
588
589 if (result)
590 return result;
591
592 acpi_processor_get_power_info_default(pr);
593
594 pr->power.count = acpi_processor_power_verify(pr);
595
596 /*
597 * if one state of type C2 or C3 is available, mark this
598 * CPU as being "idle manageable"
599 */
600 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
601 if (pr->power.states[i].valid) {
602 pr->power.count = i;
603 if (pr->power.states[i].type >= ACPI_STATE_C2)
604 pr->flags.power = 1;
605 }
606 }
607
608 return 0;
609}
610
611/**
612 * acpi_idle_bm_check - checks if bus master activity was detected
613 */
614static int acpi_idle_bm_check(void)
615{
616 u32 bm_status = 0;
617
618 if (bm_check_disable)
619 return 0;
620
621 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
622 if (bm_status)
623 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
624 /*
625 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
626 * the true state of bus mastering activity; forcing us to
627 * manually check the BMIDEA bit of each IDE channel.
628 */
629 else if (errata.piix4.bmisx) {
630 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
631 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
632 bm_status = 1;
633 }
634 return bm_status;
635}
636
637/**
638 * acpi_idle_do_entry - enter idle state using the appropriate method
639 * @cx: cstate data
640 *
641 * Caller disables interrupt before call and enables interrupt after return.
642 */
643static void acpi_idle_do_entry(struct acpi_processor_cx *cx)
644{
645 if (cx->entry_method == ACPI_CSTATE_FFH) {
646 /* Call into architectural FFH based C-state */
647 acpi_processor_ffh_cstate_enter(cx);
648 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
649 acpi_safe_halt();
650 } else {
651 /* IO port based C-state */
652 inb(cx->address);
653 /* Dummy wait op - must do something useless after P_LVL2 read
654 because chipsets cannot guarantee that STPCLK# signal
655 gets asserted in time to freeze execution properly. */
656 inl(acpi_gbl_FADT.xpm_timer_block.address);
657 }
658}
659
660/**
661 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
662 * @dev: the target CPU
663 * @index: the index of suggested state
664 */
665static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
666{
667 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
668
669 ACPI_FLUSH_CPU_CACHE();
670
671 while (1) {
672
673 if (cx->entry_method == ACPI_CSTATE_HALT)
674 safe_halt();
675 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
676 inb(cx->address);
677 /* See comment in acpi_idle_do_entry() */
678 inl(acpi_gbl_FADT.xpm_timer_block.address);
679 } else
680 return -ENODEV;
681 }
682
683 /* Never reached */
684 return 0;
685}
686
687static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
688{
689 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
690 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
691}
692
693static int c3_cpu_count;
694static DEFINE_RAW_SPINLOCK(c3_lock);
695
696/**
697 * acpi_idle_enter_bm - enters C3 with proper BM handling
698 * @pr: Target processor
699 * @cx: Target state context
700 * @timer_bc: Whether or not to change timer mode to broadcast
701 */
702static void acpi_idle_enter_bm(struct acpi_processor *pr,
703 struct acpi_processor_cx *cx, bool timer_bc)
704{
705 acpi_unlazy_tlb(smp_processor_id());
706
707 /*
708 * Must be done before busmaster disable as we might need to
709 * access HPET !
710 */
711 if (timer_bc)
712 lapic_timer_state_broadcast(pr, cx, 1);
713
714 /*
715 * disable bus master
716 * bm_check implies we need ARB_DIS
717 * bm_control implies whether we can do ARB_DIS
718 *
719 * That leaves a case where bm_check is set and bm_control is
720 * not set. In that case we cannot do much, we enter C3
721 * without doing anything.
722 */
723 if (pr->flags.bm_control) {
724 raw_spin_lock(&c3_lock);
725 c3_cpu_count++;
726 /* Disable bus master arbitration when all CPUs are in C3 */
727 if (c3_cpu_count == num_online_cpus())
728 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
729 raw_spin_unlock(&c3_lock);
730 }
731
732 acpi_idle_do_entry(cx);
733
734 /* Re-enable bus master arbitration */
735 if (pr->flags.bm_control) {
736 raw_spin_lock(&c3_lock);
737 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
738 c3_cpu_count--;
739 raw_spin_unlock(&c3_lock);
740 }
741
742 if (timer_bc)
743 lapic_timer_state_broadcast(pr, cx, 0);
744}
745
746static int acpi_idle_enter(struct cpuidle_device *dev,
747 struct cpuidle_driver *drv, int index)
748{
749 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
750 struct acpi_processor *pr;
751
752 pr = __this_cpu_read(processors);
753 if (unlikely(!pr))
754 return -EINVAL;
755
756 if (cx->type != ACPI_STATE_C1) {
757 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
758 index = CPUIDLE_DRIVER_STATE_START;
759 cx = per_cpu(acpi_cstate[index], dev->cpu);
760 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
761 if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
762 acpi_idle_enter_bm(pr, cx, true);
763 return index;
764 } else if (drv->safe_state_index >= 0) {
765 index = drv->safe_state_index;
766 cx = per_cpu(acpi_cstate[index], dev->cpu);
767 } else {
768 acpi_safe_halt();
769 return -EBUSY;
770 }
771 }
772 }
773
774 lapic_timer_state_broadcast(pr, cx, 1);
775
776 if (cx->type == ACPI_STATE_C3)
777 ACPI_FLUSH_CPU_CACHE();
778
779 acpi_idle_do_entry(cx);
780
781 lapic_timer_state_broadcast(pr, cx, 0);
782
783 return index;
784}
785
786static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
787 struct cpuidle_driver *drv, int index)
788{
789 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
790
791 if (cx->type == ACPI_STATE_C3) {
792 struct acpi_processor *pr = __this_cpu_read(processors);
793
794 if (unlikely(!pr))
795 return;
796
797 if (pr->flags.bm_check) {
798 acpi_idle_enter_bm(pr, cx, false);
799 return;
800 } else {
801 ACPI_FLUSH_CPU_CACHE();
802 }
803 }
804 acpi_idle_do_entry(cx);
805}
806
807struct cpuidle_driver acpi_idle_driver = {
808 .name = "acpi_idle",
809 .owner = THIS_MODULE,
810};
811
812/**
813 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
814 * device i.e. per-cpu data
815 *
816 * @pr: the ACPI processor
817 * @dev : the cpuidle device
818 */
819static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
820 struct cpuidle_device *dev)
821{
822 int i, count = CPUIDLE_DRIVER_STATE_START;
823 struct acpi_processor_cx *cx;
824
825 if (!pr->flags.power_setup_done)
826 return -EINVAL;
827
828 if (pr->flags.power == 0) {
829 return -EINVAL;
830 }
831
832 if (!dev)
833 return -EINVAL;
834
835 dev->cpu = pr->id;
836
837 if (max_cstate == 0)
838 max_cstate = 1;
839
840 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
841 cx = &pr->power.states[i];
842
843 if (!cx->valid)
844 continue;
845
846 per_cpu(acpi_cstate[count], dev->cpu) = cx;
847
848 count++;
849 if (count == CPUIDLE_STATE_MAX)
850 break;
851 }
852
853 if (!count)
854 return -EINVAL;
855
856 return 0;
857}
858
859/**
860 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
861 * global state data i.e. idle routines
862 *
863 * @pr: the ACPI processor
864 */
865static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
866{
867 int i, count = CPUIDLE_DRIVER_STATE_START;
868 struct acpi_processor_cx *cx;
869 struct cpuidle_state *state;
870 struct cpuidle_driver *drv = &acpi_idle_driver;
871
872 if (!pr->flags.power_setup_done)
873 return -EINVAL;
874
875 if (pr->flags.power == 0)
876 return -EINVAL;
877
878 drv->safe_state_index = -1;
879 for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
880 drv->states[i].name[0] = '\0';
881 drv->states[i].desc[0] = '\0';
882 }
883
884 if (max_cstate == 0)
885 max_cstate = 1;
886
887 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
888 cx = &pr->power.states[i];
889
890 if (!cx->valid)
891 continue;
892
893 state = &drv->states[count];
894 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
895 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
896 state->exit_latency = cx->latency;
897 state->target_residency = cx->latency * latency_factor;
898 state->enter = acpi_idle_enter;
899
900 state->flags = 0;
901 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
902 state->enter_dead = acpi_idle_play_dead;
903 drv->safe_state_index = count;
904 }
905 /*
906 * Halt-induced C1 is not good for ->enter_freeze, because it
907 * re-enables interrupts on exit. Moreover, C1 is generally not
908 * particularly interesting from the suspend-to-idle angle, so
909 * avoid C1 and the situations in which we may need to fall back
910 * to it altogether.
911 */
912 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
913 state->enter_freeze = acpi_idle_enter_freeze;
914
915 count++;
916 if (count == CPUIDLE_STATE_MAX)
917 break;
918 }
919
920 drv->state_count = count;
921
922 if (!count)
923 return -EINVAL;
924
925 return 0;
926}
927
928int acpi_processor_hotplug(struct acpi_processor *pr)
929{
930 int ret = 0;
931 struct cpuidle_device *dev;
932
933 if (disabled_by_idle_boot_param())
934 return 0;
935
936 if (nocst)
937 return -ENODEV;
938
939 if (!pr->flags.power_setup_done)
940 return -ENODEV;
941
942 dev = per_cpu(acpi_cpuidle_device, pr->id);
943 cpuidle_pause_and_lock();
944 cpuidle_disable_device(dev);
945 acpi_processor_get_power_info(pr);
946 if (pr->flags.power) {
947 acpi_processor_setup_cpuidle_cx(pr, dev);
948 ret = cpuidle_enable_device(dev);
949 }
950 cpuidle_resume_and_unlock();
951
952 return ret;
953}
954
955int acpi_processor_cst_has_changed(struct acpi_processor *pr)
956{
957 int cpu;
958 struct acpi_processor *_pr;
959 struct cpuidle_device *dev;
960
961 if (disabled_by_idle_boot_param())
962 return 0;
963
964 if (nocst)
965 return -ENODEV;
966
967 if (!pr->flags.power_setup_done)
968 return -ENODEV;
969
970 /*
971 * FIXME: Design the ACPI notification to make it once per
972 * system instead of once per-cpu. This condition is a hack
973 * to make the code that updates C-States be called once.
974 */
975
976 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
977
978 /* Protect against cpu-hotplug */
979 get_online_cpus();
980 cpuidle_pause_and_lock();
981
982 /* Disable all cpuidle devices */
983 for_each_online_cpu(cpu) {
984 _pr = per_cpu(processors, cpu);
985 if (!_pr || !_pr->flags.power_setup_done)
986 continue;
987 dev = per_cpu(acpi_cpuidle_device, cpu);
988 cpuidle_disable_device(dev);
989 }
990
991 /* Populate Updated C-state information */
992 acpi_processor_get_power_info(pr);
993 acpi_processor_setup_cpuidle_states(pr);
994
995 /* Enable all cpuidle devices */
996 for_each_online_cpu(cpu) {
997 _pr = per_cpu(processors, cpu);
998 if (!_pr || !_pr->flags.power_setup_done)
999 continue;
1000 acpi_processor_get_power_info(_pr);
1001 if (_pr->flags.power) {
1002 dev = per_cpu(acpi_cpuidle_device, cpu);
1003 acpi_processor_setup_cpuidle_cx(_pr, dev);
1004 cpuidle_enable_device(dev);
1005 }
1006 }
1007 cpuidle_resume_and_unlock();
1008 put_online_cpus();
1009 }
1010
1011 return 0;
1012}
1013
1014static int acpi_processor_registered;
1015
1016int acpi_processor_power_init(struct acpi_processor *pr)
1017{
1018 acpi_status status;
1019 int retval;
1020 struct cpuidle_device *dev;
1021 static int first_run;
1022
1023 if (disabled_by_idle_boot_param())
1024 return 0;
1025
1026 if (!first_run) {
1027 dmi_check_system(processor_power_dmi_table);
1028 max_cstate = acpi_processor_cstate_check(max_cstate);
1029 if (max_cstate < ACPI_C_STATES_MAX)
1030 printk(KERN_NOTICE
1031 "ACPI: processor limited to max C-state %d\n",
1032 max_cstate);
1033 first_run++;
1034 }
1035
1036 if (acpi_gbl_FADT.cst_control && !nocst) {
1037 status =
1038 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1039 if (ACPI_FAILURE(status)) {
1040 ACPI_EXCEPTION((AE_INFO, status,
1041 "Notifying BIOS of _CST ability failed"));
1042 }
1043 }
1044
1045 acpi_processor_get_power_info(pr);
1046 pr->flags.power_setup_done = 1;
1047
1048 /*
1049 * Install the idle handler if processor power management is supported.
1050 * Note that we use previously set idle handler will be used on
1051 * platforms that only support C1.
1052 */
1053 if (pr->flags.power) {
1054 /* Register acpi_idle_driver if not already registered */
1055 if (!acpi_processor_registered) {
1056 acpi_processor_setup_cpuidle_states(pr);
1057 retval = cpuidle_register_driver(&acpi_idle_driver);
1058 if (retval)
1059 return retval;
1060 pr_debug("%s registered with cpuidle\n",
1061 acpi_idle_driver.name);
1062 }
1063
1064 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1065 if (!dev)
1066 return -ENOMEM;
1067 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1068
1069 acpi_processor_setup_cpuidle_cx(pr, dev);
1070
1071 /* Register per-cpu cpuidle_device. Cpuidle driver
1072 * must already be registered before registering device
1073 */
1074 retval = cpuidle_register_device(dev);
1075 if (retval) {
1076 if (acpi_processor_registered == 0)
1077 cpuidle_unregister_driver(&acpi_idle_driver);
1078 return retval;
1079 }
1080 acpi_processor_registered++;
1081 }
1082 return 0;
1083}
1084
1085int acpi_processor_power_exit(struct acpi_processor *pr)
1086{
1087 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1088
1089 if (disabled_by_idle_boot_param())
1090 return 0;
1091
1092 if (pr->flags.power) {
1093 cpuidle_unregister_device(dev);
1094 acpi_processor_registered--;
1095 if (acpi_processor_registered == 0)
1096 cpuidle_unregister_driver(&acpi_idle_driver);
1097 }
1098
1099 pr->flags.power_setup_done = 0;
1100 return 0;
1101}