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Merge tag 'mac80211-for-davem-2015-05-28' of git://git.kernel.org/pub/scm/linux/kerne...
[deliverable/linux.git] / drivers / acpi / processor_idle.c
1 /*
2 * processor_idle - idle state submodule to the ACPI processor driver
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
11 *
12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License along
25 * with this program; if not, write to the Free Software Foundation, Inc.,
26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27 *
28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29 */
30
31 #include <linux/module.h>
32 #include <linux/acpi.h>
33 #include <linux/dmi.h>
34 #include <linux/sched.h> /* need_resched() */
35 #include <linux/tick.h>
36 #include <linux/cpuidle.h>
37 #include <linux/syscore_ops.h>
38 #include <acpi/processor.h>
39
40 /*
41 * Include the apic definitions for x86 to have the APIC timer related defines
42 * available also for UP (on SMP it gets magically included via linux/smp.h).
43 * asm/acpi.h is not an option, as it would require more include magic. Also
44 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
45 */
46 #ifdef CONFIG_X86
47 #include <asm/apic.h>
48 #endif
49
50 #define PREFIX "ACPI: "
51
52 #define ACPI_PROCESSOR_CLASS "processor"
53 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
54 ACPI_MODULE_NAME("processor_idle");
55
56 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
57 module_param(max_cstate, uint, 0000);
58 static unsigned int nocst __read_mostly;
59 module_param(nocst, uint, 0000);
60 static int bm_check_disable __read_mostly;
61 module_param(bm_check_disable, uint, 0000);
62
63 static unsigned int latency_factor __read_mostly = 2;
64 module_param(latency_factor, uint, 0644);
65
66 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
67
68 static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
69 acpi_cstate);
70
71 static int disabled_by_idle_boot_param(void)
72 {
73 return boot_option_idle_override == IDLE_POLL ||
74 boot_option_idle_override == IDLE_HALT;
75 }
76
77 /*
78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
79 * For now disable this. Probably a bug somewhere else.
80 *
81 * To skip this limit, boot/load with a large max_cstate limit.
82 */
83 static int set_max_cstate(const struct dmi_system_id *id)
84 {
85 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
86 return 0;
87
88 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
89 " Override with \"processor.max_cstate=%d\"\n", id->ident,
90 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
91
92 max_cstate = (long)id->driver_data;
93
94 return 0;
95 }
96
97 static struct dmi_system_id processor_power_dmi_table[] = {
98 { set_max_cstate, "Clevo 5600D", {
99 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
100 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
101 (void *)2},
102 { set_max_cstate, "Pavilion zv5000", {
103 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
104 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
105 (void *)1},
106 { set_max_cstate, "Asus L8400B", {
107 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
108 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
109 (void *)1},
110 {},
111 };
112
113
114 /*
115 * Callers should disable interrupts before the call and enable
116 * interrupts after return.
117 */
118 static void acpi_safe_halt(void)
119 {
120 if (!tif_need_resched()) {
121 safe_halt();
122 local_irq_disable();
123 }
124 }
125
126 #ifdef ARCH_APICTIMER_STOPS_ON_C3
127
128 /*
129 * Some BIOS implementations switch to C3 in the published C2 state.
130 * This seems to be a common problem on AMD boxen, but other vendors
131 * are affected too. We pick the most conservative approach: we assume
132 * that the local APIC stops in both C2 and C3.
133 */
134 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
135 struct acpi_processor_cx *cx)
136 {
137 struct acpi_processor_power *pwr = &pr->power;
138 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
139
140 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
141 return;
142
143 if (amd_e400_c1e_detected)
144 type = ACPI_STATE_C1;
145
146 /*
147 * Check, if one of the previous states already marked the lapic
148 * unstable
149 */
150 if (pwr->timer_broadcast_on_state < state)
151 return;
152
153 if (cx->type >= type)
154 pr->power.timer_broadcast_on_state = state;
155 }
156
157 static void __lapic_timer_propagate_broadcast(void *arg)
158 {
159 struct acpi_processor *pr = (struct acpi_processor *) arg;
160
161 if (pr->power.timer_broadcast_on_state < INT_MAX)
162 tick_broadcast_enable();
163 else
164 tick_broadcast_disable();
165 }
166
167 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
168 {
169 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
170 (void *)pr, 1);
171 }
172
173 /* Power(C) State timer broadcast control */
174 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
175 struct acpi_processor_cx *cx,
176 int broadcast)
177 {
178 int state = cx - pr->power.states;
179
180 if (state >= pr->power.timer_broadcast_on_state) {
181 if (broadcast)
182 tick_broadcast_enter();
183 else
184 tick_broadcast_exit();
185 }
186 }
187
188 #else
189
190 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
191 struct acpi_processor_cx *cstate) { }
192 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
193 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
194 struct acpi_processor_cx *cx,
195 int broadcast)
196 {
197 }
198
199 #endif
200
201 #ifdef CONFIG_PM_SLEEP
202 static u32 saved_bm_rld;
203
204 static int acpi_processor_suspend(void)
205 {
206 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
207 return 0;
208 }
209
210 static void acpi_processor_resume(void)
211 {
212 u32 resumed_bm_rld = 0;
213
214 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
215 if (resumed_bm_rld == saved_bm_rld)
216 return;
217
218 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
219 }
220
221 static struct syscore_ops acpi_processor_syscore_ops = {
222 .suspend = acpi_processor_suspend,
223 .resume = acpi_processor_resume,
224 };
225
226 void acpi_processor_syscore_init(void)
227 {
228 register_syscore_ops(&acpi_processor_syscore_ops);
229 }
230
231 void acpi_processor_syscore_exit(void)
232 {
233 unregister_syscore_ops(&acpi_processor_syscore_ops);
234 }
235 #endif /* CONFIG_PM_SLEEP */
236
237 #if defined(CONFIG_X86)
238 static void tsc_check_state(int state)
239 {
240 switch (boot_cpu_data.x86_vendor) {
241 case X86_VENDOR_AMD:
242 case X86_VENDOR_INTEL:
243 /*
244 * AMD Fam10h TSC will tick in all
245 * C/P/S0/S1 states when this bit is set.
246 */
247 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
248 return;
249
250 /*FALL THROUGH*/
251 default:
252 /* TSC could halt in idle, so notify users */
253 if (state > ACPI_STATE_C1)
254 mark_tsc_unstable("TSC halts in idle");
255 }
256 }
257 #else
258 static void tsc_check_state(int state) { return; }
259 #endif
260
261 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
262 {
263
264 if (!pr->pblk)
265 return -ENODEV;
266
267 /* if info is obtained from pblk/fadt, type equals state */
268 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
269 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
270
271 #ifndef CONFIG_HOTPLUG_CPU
272 /*
273 * Check for P_LVL2_UP flag before entering C2 and above on
274 * an SMP system.
275 */
276 if ((num_online_cpus() > 1) &&
277 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
278 return -ENODEV;
279 #endif
280
281 /* determine C2 and C3 address from pblk */
282 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
283 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
284
285 /* determine latencies from FADT */
286 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
287 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
288
289 /*
290 * FADT specified C2 latency must be less than or equal to
291 * 100 microseconds.
292 */
293 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
294 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
295 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
296 /* invalidate C2 */
297 pr->power.states[ACPI_STATE_C2].address = 0;
298 }
299
300 /*
301 * FADT supplied C3 latency must be less than or equal to
302 * 1000 microseconds.
303 */
304 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
305 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
306 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
307 /* invalidate C3 */
308 pr->power.states[ACPI_STATE_C3].address = 0;
309 }
310
311 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
312 "lvl2[0x%08x] lvl3[0x%08x]\n",
313 pr->power.states[ACPI_STATE_C2].address,
314 pr->power.states[ACPI_STATE_C3].address));
315
316 return 0;
317 }
318
319 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
320 {
321 if (!pr->power.states[ACPI_STATE_C1].valid) {
322 /* set the first C-State to C1 */
323 /* all processors need to support C1 */
324 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
325 pr->power.states[ACPI_STATE_C1].valid = 1;
326 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
327 }
328 /* the C0 state only exists as a filler in our array */
329 pr->power.states[ACPI_STATE_C0].valid = 1;
330 return 0;
331 }
332
333 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
334 {
335 acpi_status status;
336 u64 count;
337 int current_count;
338 int i, ret = 0;
339 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
340 union acpi_object *cst;
341
342
343 if (nocst)
344 return -ENODEV;
345
346 current_count = 0;
347
348 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
349 if (ACPI_FAILURE(status)) {
350 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
351 return -ENODEV;
352 }
353
354 cst = buffer.pointer;
355
356 /* There must be at least 2 elements */
357 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
358 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
359 ret = -EFAULT;
360 goto end;
361 }
362
363 count = cst->package.elements[0].integer.value;
364
365 /* Validate number of power states. */
366 if (count < 1 || count != cst->package.count - 1) {
367 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
368 ret = -EFAULT;
369 goto end;
370 }
371
372 /* Tell driver that at least _CST is supported. */
373 pr->flags.has_cst = 1;
374
375 for (i = 1; i <= count; i++) {
376 union acpi_object *element;
377 union acpi_object *obj;
378 struct acpi_power_register *reg;
379 struct acpi_processor_cx cx;
380
381 memset(&cx, 0, sizeof(cx));
382
383 element = &(cst->package.elements[i]);
384 if (element->type != ACPI_TYPE_PACKAGE)
385 continue;
386
387 if (element->package.count != 4)
388 continue;
389
390 obj = &(element->package.elements[0]);
391
392 if (obj->type != ACPI_TYPE_BUFFER)
393 continue;
394
395 reg = (struct acpi_power_register *)obj->buffer.pointer;
396
397 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
398 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
399 continue;
400
401 /* There should be an easy way to extract an integer... */
402 obj = &(element->package.elements[1]);
403 if (obj->type != ACPI_TYPE_INTEGER)
404 continue;
405
406 cx.type = obj->integer.value;
407 /*
408 * Some buggy BIOSes won't list C1 in _CST -
409 * Let acpi_processor_get_power_info_default() handle them later
410 */
411 if (i == 1 && cx.type != ACPI_STATE_C1)
412 current_count++;
413
414 cx.address = reg->address;
415 cx.index = current_count + 1;
416
417 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
418 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
419 if (acpi_processor_ffh_cstate_probe
420 (pr->id, &cx, reg) == 0) {
421 cx.entry_method = ACPI_CSTATE_FFH;
422 } else if (cx.type == ACPI_STATE_C1) {
423 /*
424 * C1 is a special case where FIXED_HARDWARE
425 * can be handled in non-MWAIT way as well.
426 * In that case, save this _CST entry info.
427 * Otherwise, ignore this info and continue.
428 */
429 cx.entry_method = ACPI_CSTATE_HALT;
430 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
431 } else {
432 continue;
433 }
434 if (cx.type == ACPI_STATE_C1 &&
435 (boot_option_idle_override == IDLE_NOMWAIT)) {
436 /*
437 * In most cases the C1 space_id obtained from
438 * _CST object is FIXED_HARDWARE access mode.
439 * But when the option of idle=halt is added,
440 * the entry_method type should be changed from
441 * CSTATE_FFH to CSTATE_HALT.
442 * When the option of idle=nomwait is added,
443 * the C1 entry_method type should be
444 * CSTATE_HALT.
445 */
446 cx.entry_method = ACPI_CSTATE_HALT;
447 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
448 }
449 } else {
450 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
451 cx.address);
452 }
453
454 if (cx.type == ACPI_STATE_C1) {
455 cx.valid = 1;
456 }
457
458 obj = &(element->package.elements[2]);
459 if (obj->type != ACPI_TYPE_INTEGER)
460 continue;
461
462 cx.latency = obj->integer.value;
463
464 obj = &(element->package.elements[3]);
465 if (obj->type != ACPI_TYPE_INTEGER)
466 continue;
467
468 current_count++;
469 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
470
471 /*
472 * We support total ACPI_PROCESSOR_MAX_POWER - 1
473 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
474 */
475 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
476 printk(KERN_WARNING
477 "Limiting number of power states to max (%d)\n",
478 ACPI_PROCESSOR_MAX_POWER);
479 printk(KERN_WARNING
480 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
481 break;
482 }
483 }
484
485 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
486 current_count));
487
488 /* Validate number of power states discovered */
489 if (current_count < 2)
490 ret = -EFAULT;
491
492 end:
493 kfree(buffer.pointer);
494
495 return ret;
496 }
497
498 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
499 struct acpi_processor_cx *cx)
500 {
501 static int bm_check_flag = -1;
502 static int bm_control_flag = -1;
503
504
505 if (!cx->address)
506 return;
507
508 /*
509 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
510 * DMA transfers are used by any ISA device to avoid livelock.
511 * Note that we could disable Type-F DMA (as recommended by
512 * the erratum), but this is known to disrupt certain ISA
513 * devices thus we take the conservative approach.
514 */
515 else if (errata.piix4.fdma) {
516 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
517 "C3 not supported on PIIX4 with Type-F DMA\n"));
518 return;
519 }
520
521 /* All the logic here assumes flags.bm_check is same across all CPUs */
522 if (bm_check_flag == -1) {
523 /* Determine whether bm_check is needed based on CPU */
524 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
525 bm_check_flag = pr->flags.bm_check;
526 bm_control_flag = pr->flags.bm_control;
527 } else {
528 pr->flags.bm_check = bm_check_flag;
529 pr->flags.bm_control = bm_control_flag;
530 }
531
532 if (pr->flags.bm_check) {
533 if (!pr->flags.bm_control) {
534 if (pr->flags.has_cst != 1) {
535 /* bus mastering control is necessary */
536 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
537 "C3 support requires BM control\n"));
538 return;
539 } else {
540 /* Here we enter C3 without bus mastering */
541 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
542 "C3 support without BM control\n"));
543 }
544 }
545 } else {
546 /*
547 * WBINVD should be set in fadt, for C3 state to be
548 * supported on when bm_check is not required.
549 */
550 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
551 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
552 "Cache invalidation should work properly"
553 " for C3 to be enabled on SMP systems\n"));
554 return;
555 }
556 }
557
558 /*
559 * Otherwise we've met all of our C3 requirements.
560 * Normalize the C3 latency to expidite policy. Enable
561 * checking of bus mastering status (bm_check) so we can
562 * use this in our C3 policy
563 */
564 cx->valid = 1;
565
566 /*
567 * On older chipsets, BM_RLD needs to be set
568 * in order for Bus Master activity to wake the
569 * system from C3. Newer chipsets handle DMA
570 * during C3 automatically and BM_RLD is a NOP.
571 * In either case, the proper way to
572 * handle BM_RLD is to set it and leave it set.
573 */
574 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
575
576 return;
577 }
578
579 static int acpi_processor_power_verify(struct acpi_processor *pr)
580 {
581 unsigned int i;
582 unsigned int working = 0;
583
584 pr->power.timer_broadcast_on_state = INT_MAX;
585
586 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
587 struct acpi_processor_cx *cx = &pr->power.states[i];
588
589 switch (cx->type) {
590 case ACPI_STATE_C1:
591 cx->valid = 1;
592 break;
593
594 case ACPI_STATE_C2:
595 if (!cx->address)
596 break;
597 cx->valid = 1;
598 break;
599
600 case ACPI_STATE_C3:
601 acpi_processor_power_verify_c3(pr, cx);
602 break;
603 }
604 if (!cx->valid)
605 continue;
606
607 lapic_timer_check_state(i, pr, cx);
608 tsc_check_state(cx->type);
609 working++;
610 }
611
612 lapic_timer_propagate_broadcast(pr);
613
614 return (working);
615 }
616
617 static int acpi_processor_get_power_info(struct acpi_processor *pr)
618 {
619 unsigned int i;
620 int result;
621
622
623 /* NOTE: the idle thread may not be running while calling
624 * this function */
625
626 /* Zero initialize all the C-states info. */
627 memset(pr->power.states, 0, sizeof(pr->power.states));
628
629 result = acpi_processor_get_power_info_cst(pr);
630 if (result == -ENODEV)
631 result = acpi_processor_get_power_info_fadt(pr);
632
633 if (result)
634 return result;
635
636 acpi_processor_get_power_info_default(pr);
637
638 pr->power.count = acpi_processor_power_verify(pr);
639
640 /*
641 * if one state of type C2 or C3 is available, mark this
642 * CPU as being "idle manageable"
643 */
644 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
645 if (pr->power.states[i].valid) {
646 pr->power.count = i;
647 if (pr->power.states[i].type >= ACPI_STATE_C2)
648 pr->flags.power = 1;
649 }
650 }
651
652 return 0;
653 }
654
655 /**
656 * acpi_idle_bm_check - checks if bus master activity was detected
657 */
658 static int acpi_idle_bm_check(void)
659 {
660 u32 bm_status = 0;
661
662 if (bm_check_disable)
663 return 0;
664
665 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
666 if (bm_status)
667 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
668 /*
669 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
670 * the true state of bus mastering activity; forcing us to
671 * manually check the BMIDEA bit of each IDE channel.
672 */
673 else if (errata.piix4.bmisx) {
674 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
675 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
676 bm_status = 1;
677 }
678 return bm_status;
679 }
680
681 /**
682 * acpi_idle_do_entry - enter idle state using the appropriate method
683 * @cx: cstate data
684 *
685 * Caller disables interrupt before call and enables interrupt after return.
686 */
687 static void acpi_idle_do_entry(struct acpi_processor_cx *cx)
688 {
689 if (cx->entry_method == ACPI_CSTATE_FFH) {
690 /* Call into architectural FFH based C-state */
691 acpi_processor_ffh_cstate_enter(cx);
692 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
693 acpi_safe_halt();
694 } else {
695 /* IO port based C-state */
696 inb(cx->address);
697 /* Dummy wait op - must do something useless after P_LVL2 read
698 because chipsets cannot guarantee that STPCLK# signal
699 gets asserted in time to freeze execution properly. */
700 inl(acpi_gbl_FADT.xpm_timer_block.address);
701 }
702 }
703
704 /**
705 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
706 * @dev: the target CPU
707 * @index: the index of suggested state
708 */
709 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
710 {
711 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
712
713 ACPI_FLUSH_CPU_CACHE();
714
715 while (1) {
716
717 if (cx->entry_method == ACPI_CSTATE_HALT)
718 safe_halt();
719 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
720 inb(cx->address);
721 /* See comment in acpi_idle_do_entry() */
722 inl(acpi_gbl_FADT.xpm_timer_block.address);
723 } else
724 return -ENODEV;
725 }
726
727 /* Never reached */
728 return 0;
729 }
730
731 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
732 {
733 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
734 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
735 }
736
737 static int c3_cpu_count;
738 static DEFINE_RAW_SPINLOCK(c3_lock);
739
740 /**
741 * acpi_idle_enter_bm - enters C3 with proper BM handling
742 * @pr: Target processor
743 * @cx: Target state context
744 * @timer_bc: Whether or not to change timer mode to broadcast
745 */
746 static void acpi_idle_enter_bm(struct acpi_processor *pr,
747 struct acpi_processor_cx *cx, bool timer_bc)
748 {
749 acpi_unlazy_tlb(smp_processor_id());
750
751 /*
752 * Must be done before busmaster disable as we might need to
753 * access HPET !
754 */
755 if (timer_bc)
756 lapic_timer_state_broadcast(pr, cx, 1);
757
758 /*
759 * disable bus master
760 * bm_check implies we need ARB_DIS
761 * bm_control implies whether we can do ARB_DIS
762 *
763 * That leaves a case where bm_check is set and bm_control is
764 * not set. In that case we cannot do much, we enter C3
765 * without doing anything.
766 */
767 if (pr->flags.bm_control) {
768 raw_spin_lock(&c3_lock);
769 c3_cpu_count++;
770 /* Disable bus master arbitration when all CPUs are in C3 */
771 if (c3_cpu_count == num_online_cpus())
772 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
773 raw_spin_unlock(&c3_lock);
774 }
775
776 acpi_idle_do_entry(cx);
777
778 /* Re-enable bus master arbitration */
779 if (pr->flags.bm_control) {
780 raw_spin_lock(&c3_lock);
781 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
782 c3_cpu_count--;
783 raw_spin_unlock(&c3_lock);
784 }
785
786 if (timer_bc)
787 lapic_timer_state_broadcast(pr, cx, 0);
788 }
789
790 static int acpi_idle_enter(struct cpuidle_device *dev,
791 struct cpuidle_driver *drv, int index)
792 {
793 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
794 struct acpi_processor *pr;
795
796 pr = __this_cpu_read(processors);
797 if (unlikely(!pr))
798 return -EINVAL;
799
800 if (cx->type != ACPI_STATE_C1) {
801 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
802 index = CPUIDLE_DRIVER_STATE_START;
803 cx = per_cpu(acpi_cstate[index], dev->cpu);
804 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
805 if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
806 acpi_idle_enter_bm(pr, cx, true);
807 return index;
808 } else if (drv->safe_state_index >= 0) {
809 index = drv->safe_state_index;
810 cx = per_cpu(acpi_cstate[index], dev->cpu);
811 } else {
812 acpi_safe_halt();
813 return -EBUSY;
814 }
815 }
816 }
817
818 lapic_timer_state_broadcast(pr, cx, 1);
819
820 if (cx->type == ACPI_STATE_C3)
821 ACPI_FLUSH_CPU_CACHE();
822
823 acpi_idle_do_entry(cx);
824
825 lapic_timer_state_broadcast(pr, cx, 0);
826
827 return index;
828 }
829
830 static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
831 struct cpuidle_driver *drv, int index)
832 {
833 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
834
835 if (cx->type == ACPI_STATE_C3) {
836 struct acpi_processor *pr = __this_cpu_read(processors);
837
838 if (unlikely(!pr))
839 return;
840
841 if (pr->flags.bm_check) {
842 acpi_idle_enter_bm(pr, cx, false);
843 return;
844 } else {
845 ACPI_FLUSH_CPU_CACHE();
846 }
847 }
848 acpi_idle_do_entry(cx);
849 }
850
851 struct cpuidle_driver acpi_idle_driver = {
852 .name = "acpi_idle",
853 .owner = THIS_MODULE,
854 };
855
856 /**
857 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
858 * device i.e. per-cpu data
859 *
860 * @pr: the ACPI processor
861 * @dev : the cpuidle device
862 */
863 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
864 struct cpuidle_device *dev)
865 {
866 int i, count = CPUIDLE_DRIVER_STATE_START;
867 struct acpi_processor_cx *cx;
868
869 if (!pr->flags.power_setup_done)
870 return -EINVAL;
871
872 if (pr->flags.power == 0) {
873 return -EINVAL;
874 }
875
876 if (!dev)
877 return -EINVAL;
878
879 dev->cpu = pr->id;
880
881 if (max_cstate == 0)
882 max_cstate = 1;
883
884 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
885 cx = &pr->power.states[i];
886
887 if (!cx->valid)
888 continue;
889
890 per_cpu(acpi_cstate[count], dev->cpu) = cx;
891
892 count++;
893 if (count == CPUIDLE_STATE_MAX)
894 break;
895 }
896
897 if (!count)
898 return -EINVAL;
899
900 return 0;
901 }
902
903 /**
904 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
905 * global state data i.e. idle routines
906 *
907 * @pr: the ACPI processor
908 */
909 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
910 {
911 int i, count = CPUIDLE_DRIVER_STATE_START;
912 struct acpi_processor_cx *cx;
913 struct cpuidle_state *state;
914 struct cpuidle_driver *drv = &acpi_idle_driver;
915
916 if (!pr->flags.power_setup_done)
917 return -EINVAL;
918
919 if (pr->flags.power == 0)
920 return -EINVAL;
921
922 drv->safe_state_index = -1;
923 for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
924 drv->states[i].name[0] = '\0';
925 drv->states[i].desc[0] = '\0';
926 }
927
928 if (max_cstate == 0)
929 max_cstate = 1;
930
931 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
932 cx = &pr->power.states[i];
933
934 if (!cx->valid)
935 continue;
936
937 state = &drv->states[count];
938 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
939 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
940 state->exit_latency = cx->latency;
941 state->target_residency = cx->latency * latency_factor;
942 state->enter = acpi_idle_enter;
943
944 state->flags = 0;
945 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
946 state->enter_dead = acpi_idle_play_dead;
947 drv->safe_state_index = count;
948 }
949 /*
950 * Halt-induced C1 is not good for ->enter_freeze, because it
951 * re-enables interrupts on exit. Moreover, C1 is generally not
952 * particularly interesting from the suspend-to-idle angle, so
953 * avoid C1 and the situations in which we may need to fall back
954 * to it altogether.
955 */
956 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
957 state->enter_freeze = acpi_idle_enter_freeze;
958
959 count++;
960 if (count == CPUIDLE_STATE_MAX)
961 break;
962 }
963
964 drv->state_count = count;
965
966 if (!count)
967 return -EINVAL;
968
969 return 0;
970 }
971
972 int acpi_processor_hotplug(struct acpi_processor *pr)
973 {
974 int ret = 0;
975 struct cpuidle_device *dev;
976
977 if (disabled_by_idle_boot_param())
978 return 0;
979
980 if (nocst)
981 return -ENODEV;
982
983 if (!pr->flags.power_setup_done)
984 return -ENODEV;
985
986 dev = per_cpu(acpi_cpuidle_device, pr->id);
987 cpuidle_pause_and_lock();
988 cpuidle_disable_device(dev);
989 acpi_processor_get_power_info(pr);
990 if (pr->flags.power) {
991 acpi_processor_setup_cpuidle_cx(pr, dev);
992 ret = cpuidle_enable_device(dev);
993 }
994 cpuidle_resume_and_unlock();
995
996 return ret;
997 }
998
999 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1000 {
1001 int cpu;
1002 struct acpi_processor *_pr;
1003 struct cpuidle_device *dev;
1004
1005 if (disabled_by_idle_boot_param())
1006 return 0;
1007
1008 if (nocst)
1009 return -ENODEV;
1010
1011 if (!pr->flags.power_setup_done)
1012 return -ENODEV;
1013
1014 /*
1015 * FIXME: Design the ACPI notification to make it once per
1016 * system instead of once per-cpu. This condition is a hack
1017 * to make the code that updates C-States be called once.
1018 */
1019
1020 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1021
1022 /* Protect against cpu-hotplug */
1023 get_online_cpus();
1024 cpuidle_pause_and_lock();
1025
1026 /* Disable all cpuidle devices */
1027 for_each_online_cpu(cpu) {
1028 _pr = per_cpu(processors, cpu);
1029 if (!_pr || !_pr->flags.power_setup_done)
1030 continue;
1031 dev = per_cpu(acpi_cpuidle_device, cpu);
1032 cpuidle_disable_device(dev);
1033 }
1034
1035 /* Populate Updated C-state information */
1036 acpi_processor_get_power_info(pr);
1037 acpi_processor_setup_cpuidle_states(pr);
1038
1039 /* Enable all cpuidle devices */
1040 for_each_online_cpu(cpu) {
1041 _pr = per_cpu(processors, cpu);
1042 if (!_pr || !_pr->flags.power_setup_done)
1043 continue;
1044 acpi_processor_get_power_info(_pr);
1045 if (_pr->flags.power) {
1046 dev = per_cpu(acpi_cpuidle_device, cpu);
1047 acpi_processor_setup_cpuidle_cx(_pr, dev);
1048 cpuidle_enable_device(dev);
1049 }
1050 }
1051 cpuidle_resume_and_unlock();
1052 put_online_cpus();
1053 }
1054
1055 return 0;
1056 }
1057
1058 static int acpi_processor_registered;
1059
1060 int acpi_processor_power_init(struct acpi_processor *pr)
1061 {
1062 acpi_status status;
1063 int retval;
1064 struct cpuidle_device *dev;
1065 static int first_run;
1066
1067 if (disabled_by_idle_boot_param())
1068 return 0;
1069
1070 if (!first_run) {
1071 dmi_check_system(processor_power_dmi_table);
1072 max_cstate = acpi_processor_cstate_check(max_cstate);
1073 if (max_cstate < ACPI_C_STATES_MAX)
1074 printk(KERN_NOTICE
1075 "ACPI: processor limited to max C-state %d\n",
1076 max_cstate);
1077 first_run++;
1078 }
1079
1080 if (acpi_gbl_FADT.cst_control && !nocst) {
1081 status =
1082 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1083 if (ACPI_FAILURE(status)) {
1084 ACPI_EXCEPTION((AE_INFO, status,
1085 "Notifying BIOS of _CST ability failed"));
1086 }
1087 }
1088
1089 acpi_processor_get_power_info(pr);
1090 pr->flags.power_setup_done = 1;
1091
1092 /*
1093 * Install the idle handler if processor power management is supported.
1094 * Note that we use previously set idle handler will be used on
1095 * platforms that only support C1.
1096 */
1097 if (pr->flags.power) {
1098 /* Register acpi_idle_driver if not already registered */
1099 if (!acpi_processor_registered) {
1100 acpi_processor_setup_cpuidle_states(pr);
1101 retval = cpuidle_register_driver(&acpi_idle_driver);
1102 if (retval)
1103 return retval;
1104 printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1105 acpi_idle_driver.name);
1106 }
1107
1108 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1109 if (!dev)
1110 return -ENOMEM;
1111 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1112
1113 acpi_processor_setup_cpuidle_cx(pr, dev);
1114
1115 /* Register per-cpu cpuidle_device. Cpuidle driver
1116 * must already be registered before registering device
1117 */
1118 retval = cpuidle_register_device(dev);
1119 if (retval) {
1120 if (acpi_processor_registered == 0)
1121 cpuidle_unregister_driver(&acpi_idle_driver);
1122 return retval;
1123 }
1124 acpi_processor_registered++;
1125 }
1126 return 0;
1127 }
1128
1129 int acpi_processor_power_exit(struct acpi_processor *pr)
1130 {
1131 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1132
1133 if (disabled_by_idle_boot_param())
1134 return 0;
1135
1136 if (pr->flags.power) {
1137 cpuidle_unregister_device(dev);
1138 acpi_processor_registered--;
1139 if (acpi_processor_registered == 0)
1140 cpuidle_unregister_driver(&acpi_idle_driver);
1141 }
1142
1143 pr->flags.power_setup_done = 0;
1144 return 0;
1145 }
Linux kernel - Deliverables
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