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