Loading...
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/kernel.h>
32#include <linux/module.h>
33#include <linux/init.h>
34#include <linux/cpufreq.h>
35#include <linux/slab.h>
36#include <linux/acpi.h>
37#include <linux/dmi.h>
38#include <linux/moduleparam.h>
39#include <linux/sched.h> /* need_resched() */
40#include <linux/pm_qos.h>
41#include <linux/clockchips.h>
42#include <linux/cpuidle.h>
43#include <linux/irqflags.h>
44
45/*
46 * Include the apic definitions for x86 to have the APIC timer related defines
47 * available also for UP (on SMP it gets magically included via linux/smp.h).
48 * asm/acpi.h is not an option, as it would require more include magic. Also
49 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
50 */
51#ifdef CONFIG_X86
52#include <asm/apic.h>
53#endif
54
55#include <asm/io.h>
56#include <asm/uaccess.h>
57
58#include <acpi/acpi_bus.h>
59#include <acpi/processor.h>
60#include <asm/processor.h>
61
62#define PREFIX "ACPI: "
63
64#define ACPI_PROCESSOR_CLASS "processor"
65#define _COMPONENT ACPI_PROCESSOR_COMPONENT
66ACPI_MODULE_NAME("processor_idle");
67#define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY)
68#define C2_OVERHEAD 1 /* 1us */
69#define C3_OVERHEAD 1 /* 1us */
70#define PM_TIMER_TICKS_TO_US(p) (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
71
72static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
73module_param(max_cstate, uint, 0000);
74static unsigned int nocst __read_mostly;
75module_param(nocst, uint, 0000);
76static int bm_check_disable __read_mostly;
77module_param(bm_check_disable, uint, 0000);
78
79static unsigned int latency_factor __read_mostly = 2;
80module_param(latency_factor, uint, 0644);
81
82static int disabled_by_idle_boot_param(void)
83{
84 return boot_option_idle_override == IDLE_POLL ||
85 boot_option_idle_override == IDLE_FORCE_MWAIT ||
86 boot_option_idle_override == IDLE_HALT;
87}
88
89/*
90 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
91 * For now disable this. Probably a bug somewhere else.
92 *
93 * To skip this limit, boot/load with a large max_cstate limit.
94 */
95static int set_max_cstate(const struct dmi_system_id *id)
96{
97 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
98 return 0;
99
100 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
101 " Override with \"processor.max_cstate=%d\"\n", id->ident,
102 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
103
104 max_cstate = (long)id->driver_data;
105
106 return 0;
107}
108
109/* Actually this shouldn't be __cpuinitdata, would be better to fix the
110 callers to only run once -AK */
111static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
112 { set_max_cstate, "Clevo 5600D", {
113 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
114 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
115 (void *)2},
116 { set_max_cstate, "Pavilion zv5000", {
117 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
118 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
119 (void *)1},
120 { set_max_cstate, "Asus L8400B", {
121 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
122 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
123 (void *)1},
124 {},
125};
126
127
128/*
129 * Callers should disable interrupts before the call and enable
130 * interrupts after return.
131 */
132static void acpi_safe_halt(void)
133{
134 current_thread_info()->status &= ~TS_POLLING;
135 /*
136 * TS_POLLING-cleared state must be visible before we
137 * test NEED_RESCHED:
138 */
139 smp_mb();
140 if (!need_resched()) {
141 safe_halt();
142 local_irq_disable();
143 }
144 current_thread_info()->status |= TS_POLLING;
145}
146
147#ifdef ARCH_APICTIMER_STOPS_ON_C3
148
149/*
150 * Some BIOS implementations switch to C3 in the published C2 state.
151 * This seems to be a common problem on AMD boxen, but other vendors
152 * are affected too. We pick the most conservative approach: we assume
153 * that the local APIC stops in both C2 and C3.
154 */
155static void lapic_timer_check_state(int state, struct acpi_processor *pr,
156 struct acpi_processor_cx *cx)
157{
158 struct acpi_processor_power *pwr = &pr->power;
159 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
160
161 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
162 return;
163
164 if (amd_e400_c1e_detected)
165 type = ACPI_STATE_C1;
166
167 /*
168 * Check, if one of the previous states already marked the lapic
169 * unstable
170 */
171 if (pwr->timer_broadcast_on_state < state)
172 return;
173
174 if (cx->type >= type)
175 pr->power.timer_broadcast_on_state = state;
176}
177
178static void __lapic_timer_propagate_broadcast(void *arg)
179{
180 struct acpi_processor *pr = (struct acpi_processor *) arg;
181 unsigned long reason;
182
183 reason = pr->power.timer_broadcast_on_state < INT_MAX ?
184 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
185
186 clockevents_notify(reason, &pr->id);
187}
188
189static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
190{
191 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
192 (void *)pr, 1);
193}
194
195/* Power(C) State timer broadcast control */
196static void lapic_timer_state_broadcast(struct acpi_processor *pr,
197 struct acpi_processor_cx *cx,
198 int broadcast)
199{
200 int state = cx - pr->power.states;
201
202 if (state >= pr->power.timer_broadcast_on_state) {
203 unsigned long reason;
204
205 reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
206 CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
207 clockevents_notify(reason, &pr->id);
208 }
209}
210
211#else
212
213static void lapic_timer_check_state(int state, struct acpi_processor *pr,
214 struct acpi_processor_cx *cstate) { }
215static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
216static void lapic_timer_state_broadcast(struct acpi_processor *pr,
217 struct acpi_processor_cx *cx,
218 int broadcast)
219{
220}
221
222#endif
223
224/*
225 * Suspend / resume control
226 */
227static int acpi_idle_suspend;
228static u32 saved_bm_rld;
229
230static void acpi_idle_bm_rld_save(void)
231{
232 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
233}
234static void acpi_idle_bm_rld_restore(void)
235{
236 u32 resumed_bm_rld;
237
238 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
239
240 if (resumed_bm_rld != saved_bm_rld)
241 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
242}
243
244int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
245{
246 if (acpi_idle_suspend == 1)
247 return 0;
248
249 acpi_idle_bm_rld_save();
250 acpi_idle_suspend = 1;
251 return 0;
252}
253
254int acpi_processor_resume(struct acpi_device * device)
255{
256 if (acpi_idle_suspend == 0)
257 return 0;
258
259 acpi_idle_bm_rld_restore();
260 acpi_idle_suspend = 0;
261 return 0;
262}
263
264#if defined(CONFIG_X86)
265static void tsc_check_state(int state)
266{
267 switch (boot_cpu_data.x86_vendor) {
268 case X86_VENDOR_AMD:
269 case X86_VENDOR_INTEL:
270 /*
271 * AMD Fam10h TSC will tick in all
272 * C/P/S0/S1 states when this bit is set.
273 */
274 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
275 return;
276
277 /*FALL THROUGH*/
278 default:
279 /* TSC could halt in idle, so notify users */
280 if (state > ACPI_STATE_C1)
281 mark_tsc_unstable("TSC halts in idle");
282 }
283}
284#else
285static void tsc_check_state(int state) { return; }
286#endif
287
288static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
289{
290
291 if (!pr)
292 return -EINVAL;
293
294 if (!pr->pblk)
295 return -ENODEV;
296
297 /* if info is obtained from pblk/fadt, type equals state */
298 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
299 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
300
301#ifndef CONFIG_HOTPLUG_CPU
302 /*
303 * Check for P_LVL2_UP flag before entering C2 and above on
304 * an SMP system.
305 */
306 if ((num_online_cpus() > 1) &&
307 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
308 return -ENODEV;
309#endif
310
311 /* determine C2 and C3 address from pblk */
312 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
313 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
314
315 /* determine latencies from FADT */
316 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
317 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
318
319 /*
320 * FADT specified C2 latency must be less than or equal to
321 * 100 microseconds.
322 */
323 if (acpi_gbl_FADT.C2latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
324 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
325 "C2 latency too large [%d]\n", acpi_gbl_FADT.C2latency));
326 /* invalidate C2 */
327 pr->power.states[ACPI_STATE_C2].address = 0;
328 }
329
330 /*
331 * FADT supplied C3 latency must be less than or equal to
332 * 1000 microseconds.
333 */
334 if (acpi_gbl_FADT.C3latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
335 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
336 "C3 latency too large [%d]\n", acpi_gbl_FADT.C3latency));
337 /* invalidate C3 */
338 pr->power.states[ACPI_STATE_C3].address = 0;
339 }
340
341 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
342 "lvl2[0x%08x] lvl3[0x%08x]\n",
343 pr->power.states[ACPI_STATE_C2].address,
344 pr->power.states[ACPI_STATE_C3].address));
345
346 return 0;
347}
348
349static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
350{
351 if (!pr->power.states[ACPI_STATE_C1].valid) {
352 /* set the first C-State to C1 */
353 /* all processors need to support C1 */
354 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
355 pr->power.states[ACPI_STATE_C1].valid = 1;
356 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
357 }
358 /* the C0 state only exists as a filler in our array */
359 pr->power.states[ACPI_STATE_C0].valid = 1;
360 return 0;
361}
362
363static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
364{
365 acpi_status status = 0;
366 u64 count;
367 int current_count;
368 int i;
369 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
370 union acpi_object *cst;
371
372
373 if (nocst)
374 return -ENODEV;
375
376 current_count = 0;
377
378 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
379 if (ACPI_FAILURE(status)) {
380 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
381 return -ENODEV;
382 }
383
384 cst = buffer.pointer;
385
386 /* There must be at least 2 elements */
387 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
388 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
389 status = -EFAULT;
390 goto end;
391 }
392
393 count = cst->package.elements[0].integer.value;
394
395 /* Validate number of power states. */
396 if (count < 1 || count != cst->package.count - 1) {
397 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
398 status = -EFAULT;
399 goto end;
400 }
401
402 /* Tell driver that at least _CST is supported. */
403 pr->flags.has_cst = 1;
404
405 for (i = 1; i <= count; i++) {
406 union acpi_object *element;
407 union acpi_object *obj;
408 struct acpi_power_register *reg;
409 struct acpi_processor_cx cx;
410
411 memset(&cx, 0, sizeof(cx));
412
413 element = &(cst->package.elements[i]);
414 if (element->type != ACPI_TYPE_PACKAGE)
415 continue;
416
417 if (element->package.count != 4)
418 continue;
419
420 obj = &(element->package.elements[0]);
421
422 if (obj->type != ACPI_TYPE_BUFFER)
423 continue;
424
425 reg = (struct acpi_power_register *)obj->buffer.pointer;
426
427 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
428 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
429 continue;
430
431 /* There should be an easy way to extract an integer... */
432 obj = &(element->package.elements[1]);
433 if (obj->type != ACPI_TYPE_INTEGER)
434 continue;
435
436 cx.type = obj->integer.value;
437 /*
438 * Some buggy BIOSes won't list C1 in _CST -
439 * Let acpi_processor_get_power_info_default() handle them later
440 */
441 if (i == 1 && cx.type != ACPI_STATE_C1)
442 current_count++;
443
444 cx.address = reg->address;
445 cx.index = current_count + 1;
446
447 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
448 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
449 if (acpi_processor_ffh_cstate_probe
450 (pr->id, &cx, reg) == 0) {
451 cx.entry_method = ACPI_CSTATE_FFH;
452 } else if (cx.type == ACPI_STATE_C1) {
453 /*
454 * C1 is a special case where FIXED_HARDWARE
455 * can be handled in non-MWAIT way as well.
456 * In that case, save this _CST entry info.
457 * Otherwise, ignore this info and continue.
458 */
459 cx.entry_method = ACPI_CSTATE_HALT;
460 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
461 } else {
462 continue;
463 }
464 if (cx.type == ACPI_STATE_C1 &&
465 (boot_option_idle_override == IDLE_NOMWAIT)) {
466 /*
467 * In most cases the C1 space_id obtained from
468 * _CST object is FIXED_HARDWARE access mode.
469 * But when the option of idle=halt is added,
470 * the entry_method type should be changed from
471 * CSTATE_FFH to CSTATE_HALT.
472 * When the option of idle=nomwait is added,
473 * the C1 entry_method type should be
474 * CSTATE_HALT.
475 */
476 cx.entry_method = ACPI_CSTATE_HALT;
477 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
478 }
479 } else {
480 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
481 cx.address);
482 }
483
484 if (cx.type == ACPI_STATE_C1) {
485 cx.valid = 1;
486 }
487
488 obj = &(element->package.elements[2]);
489 if (obj->type != ACPI_TYPE_INTEGER)
490 continue;
491
492 cx.latency = obj->integer.value;
493
494 obj = &(element->package.elements[3]);
495 if (obj->type != ACPI_TYPE_INTEGER)
496 continue;
497
498 cx.power = obj->integer.value;
499
500 current_count++;
501 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
502
503 /*
504 * We support total ACPI_PROCESSOR_MAX_POWER - 1
505 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
506 */
507 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
508 printk(KERN_WARNING
509 "Limiting number of power states to max (%d)\n",
510 ACPI_PROCESSOR_MAX_POWER);
511 printk(KERN_WARNING
512 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
513 break;
514 }
515 }
516
517 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
518 current_count));
519
520 /* Validate number of power states discovered */
521 if (current_count < 2)
522 status = -EFAULT;
523
524 end:
525 kfree(buffer.pointer);
526
527 return status;
528}
529
530static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
531 struct acpi_processor_cx *cx)
532{
533 static int bm_check_flag = -1;
534 static int bm_control_flag = -1;
535
536
537 if (!cx->address)
538 return;
539
540 /*
541 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
542 * DMA transfers are used by any ISA device to avoid livelock.
543 * Note that we could disable Type-F DMA (as recommended by
544 * the erratum), but this is known to disrupt certain ISA
545 * devices thus we take the conservative approach.
546 */
547 else if (errata.piix4.fdma) {
548 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
549 "C3 not supported on PIIX4 with Type-F DMA\n"));
550 return;
551 }
552
553 /* All the logic here assumes flags.bm_check is same across all CPUs */
554 if (bm_check_flag == -1) {
555 /* Determine whether bm_check is needed based on CPU */
556 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
557 bm_check_flag = pr->flags.bm_check;
558 bm_control_flag = pr->flags.bm_control;
559 } else {
560 pr->flags.bm_check = bm_check_flag;
561 pr->flags.bm_control = bm_control_flag;
562 }
563
564 if (pr->flags.bm_check) {
565 if (!pr->flags.bm_control) {
566 if (pr->flags.has_cst != 1) {
567 /* bus mastering control is necessary */
568 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
569 "C3 support requires BM control\n"));
570 return;
571 } else {
572 /* Here we enter C3 without bus mastering */
573 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
574 "C3 support without BM control\n"));
575 }
576 }
577 } else {
578 /*
579 * WBINVD should be set in fadt, for C3 state to be
580 * supported on when bm_check is not required.
581 */
582 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
583 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
584 "Cache invalidation should work properly"
585 " for C3 to be enabled on SMP systems\n"));
586 return;
587 }
588 }
589
590 /*
591 * Otherwise we've met all of our C3 requirements.
592 * Normalize the C3 latency to expidite policy. Enable
593 * checking of bus mastering status (bm_check) so we can
594 * use this in our C3 policy
595 */
596 cx->valid = 1;
597
598 cx->latency_ticks = cx->latency;
599 /*
600 * On older chipsets, BM_RLD needs to be set
601 * in order for Bus Master activity to wake the
602 * system from C3. Newer chipsets handle DMA
603 * during C3 automatically and BM_RLD is a NOP.
604 * In either case, the proper way to
605 * handle BM_RLD is to set it and leave it set.
606 */
607 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
608
609 return;
610}
611
612static int acpi_processor_power_verify(struct acpi_processor *pr)
613{
614 unsigned int i;
615 unsigned int working = 0;
616
617 pr->power.timer_broadcast_on_state = INT_MAX;
618
619 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
620 struct acpi_processor_cx *cx = &pr->power.states[i];
621
622 switch (cx->type) {
623 case ACPI_STATE_C1:
624 cx->valid = 1;
625 break;
626
627 case ACPI_STATE_C2:
628 if (!cx->address)
629 break;
630 cx->valid = 1;
631 cx->latency_ticks = cx->latency; /* Normalize latency */
632 break;
633
634 case ACPI_STATE_C3:
635 acpi_processor_power_verify_c3(pr, cx);
636 break;
637 }
638 if (!cx->valid)
639 continue;
640
641 lapic_timer_check_state(i, pr, cx);
642 tsc_check_state(cx->type);
643 working++;
644 }
645
646 lapic_timer_propagate_broadcast(pr);
647
648 return (working);
649}
650
651static int acpi_processor_get_power_info(struct acpi_processor *pr)
652{
653 unsigned int i;
654 int result;
655
656
657 /* NOTE: the idle thread may not be running while calling
658 * this function */
659
660 /* Zero initialize all the C-states info. */
661 memset(pr->power.states, 0, sizeof(pr->power.states));
662
663 result = acpi_processor_get_power_info_cst(pr);
664 if (result == -ENODEV)
665 result = acpi_processor_get_power_info_fadt(pr);
666
667 if (result)
668 return result;
669
670 acpi_processor_get_power_info_default(pr);
671
672 pr->power.count = acpi_processor_power_verify(pr);
673
674 /*
675 * if one state of type C2 or C3 is available, mark this
676 * CPU as being "idle manageable"
677 */
678 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
679 if (pr->power.states[i].valid) {
680 pr->power.count = i;
681 if (pr->power.states[i].type >= ACPI_STATE_C2)
682 pr->flags.power = 1;
683 }
684 }
685
686 return 0;
687}
688
689/**
690 * acpi_idle_bm_check - checks if bus master activity was detected
691 */
692static int acpi_idle_bm_check(void)
693{
694 u32 bm_status = 0;
695
696 if (bm_check_disable)
697 return 0;
698
699 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
700 if (bm_status)
701 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
702 /*
703 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
704 * the true state of bus mastering activity; forcing us to
705 * manually check the BMIDEA bit of each IDE channel.
706 */
707 else if (errata.piix4.bmisx) {
708 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
709 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
710 bm_status = 1;
711 }
712 return bm_status;
713}
714
715/**
716 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
717 * @cx: cstate data
718 *
719 * Caller disables interrupt before call and enables interrupt after return.
720 */
721static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
722{
723 /* Don't trace irqs off for idle */
724 stop_critical_timings();
725 if (cx->entry_method == ACPI_CSTATE_FFH) {
726 /* Call into architectural FFH based C-state */
727 acpi_processor_ffh_cstate_enter(cx);
728 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
729 acpi_safe_halt();
730 } else {
731 /* IO port based C-state */
732 inb(cx->address);
733 /* Dummy wait op - must do something useless after P_LVL2 read
734 because chipsets cannot guarantee that STPCLK# signal
735 gets asserted in time to freeze execution properly. */
736 inl(acpi_gbl_FADT.xpm_timer_block.address);
737 }
738 start_critical_timings();
739}
740
741/**
742 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
743 * @dev: the target CPU
744 * @drv: cpuidle driver containing cpuidle state info
745 * @index: index of target state
746 *
747 * This is equivalent to the HALT instruction.
748 */
749static int acpi_idle_enter_c1(struct cpuidle_device *dev,
750 struct cpuidle_driver *drv, int index)
751{
752 ktime_t kt1, kt2;
753 s64 idle_time;
754 struct acpi_processor *pr;
755 struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
756 struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
757
758 pr = __this_cpu_read(processors);
759 dev->last_residency = 0;
760
761 if (unlikely(!pr))
762 return -EINVAL;
763
764 local_irq_disable();
765
766 if (acpi_idle_suspend) {
767 local_irq_enable();
768 cpu_relax();
769 return -EBUSY;
770 }
771
772 lapic_timer_state_broadcast(pr, cx, 1);
773 kt1 = ktime_get_real();
774 acpi_idle_do_entry(cx);
775 kt2 = ktime_get_real();
776 idle_time = ktime_to_us(ktime_sub(kt2, kt1));
777
778 /* Update device last_residency*/
779 dev->last_residency = (int)idle_time;
780
781 local_irq_enable();
782 cx->usage++;
783 lapic_timer_state_broadcast(pr, cx, 0);
784
785 return index;
786}
787
788
789/**
790 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
791 * @dev: the target CPU
792 * @index: the index of suggested state
793 */
794static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
795{
796 struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
797 struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
798
799 ACPI_FLUSH_CPU_CACHE();
800
801 while (1) {
802
803 if (cx->entry_method == ACPI_CSTATE_HALT)
804 safe_halt();
805 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
806 inb(cx->address);
807 /* See comment in acpi_idle_do_entry() */
808 inl(acpi_gbl_FADT.xpm_timer_block.address);
809 } else
810 return -ENODEV;
811 }
812
813 /* Never reached */
814 return 0;
815}
816
817/**
818 * acpi_idle_enter_simple - enters an ACPI state without BM handling
819 * @dev: the target CPU
820 * @drv: cpuidle driver with cpuidle state information
821 * @index: the index of suggested state
822 */
823static int acpi_idle_enter_simple(struct cpuidle_device *dev,
824 struct cpuidle_driver *drv, int index)
825{
826 struct acpi_processor *pr;
827 struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
828 struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
829 ktime_t kt1, kt2;
830 s64 idle_time_ns;
831 s64 idle_time;
832
833 pr = __this_cpu_read(processors);
834 dev->last_residency = 0;
835
836 if (unlikely(!pr))
837 return -EINVAL;
838
839 local_irq_disable();
840
841 if (acpi_idle_suspend) {
842 local_irq_enable();
843 cpu_relax();
844 return -EBUSY;
845 }
846
847 if (cx->entry_method != ACPI_CSTATE_FFH) {
848 current_thread_info()->status &= ~TS_POLLING;
849 /*
850 * TS_POLLING-cleared state must be visible before we test
851 * NEED_RESCHED:
852 */
853 smp_mb();
854
855 if (unlikely(need_resched())) {
856 current_thread_info()->status |= TS_POLLING;
857 local_irq_enable();
858 return -EINVAL;
859 }
860 }
861
862 /*
863 * Must be done before busmaster disable as we might need to
864 * access HPET !
865 */
866 lapic_timer_state_broadcast(pr, cx, 1);
867
868 if (cx->type == ACPI_STATE_C3)
869 ACPI_FLUSH_CPU_CACHE();
870
871 kt1 = ktime_get_real();
872 /* Tell the scheduler that we are going deep-idle: */
873 sched_clock_idle_sleep_event();
874 acpi_idle_do_entry(cx);
875 kt2 = ktime_get_real();
876 idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
877 idle_time = idle_time_ns;
878 do_div(idle_time, NSEC_PER_USEC);
879
880 /* Update device last_residency*/
881 dev->last_residency = (int)idle_time;
882
883 /* Tell the scheduler how much we idled: */
884 sched_clock_idle_wakeup_event(idle_time_ns);
885
886 local_irq_enable();
887 if (cx->entry_method != ACPI_CSTATE_FFH)
888 current_thread_info()->status |= TS_POLLING;
889
890 cx->usage++;
891
892 lapic_timer_state_broadcast(pr, cx, 0);
893 cx->time += idle_time;
894 return index;
895}
896
897static int c3_cpu_count;
898static DEFINE_RAW_SPINLOCK(c3_lock);
899
900/**
901 * acpi_idle_enter_bm - enters C3 with proper BM handling
902 * @dev: the target CPU
903 * @drv: cpuidle driver containing state data
904 * @index: the index of suggested state
905 *
906 * If BM is detected, the deepest non-C3 idle state is entered instead.
907 */
908static int acpi_idle_enter_bm(struct cpuidle_device *dev,
909 struct cpuidle_driver *drv, int index)
910{
911 struct acpi_processor *pr;
912 struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
913 struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
914 ktime_t kt1, kt2;
915 s64 idle_time_ns;
916 s64 idle_time;
917
918
919 pr = __this_cpu_read(processors);
920 dev->last_residency = 0;
921
922 if (unlikely(!pr))
923 return -EINVAL;
924
925 if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
926 if (drv->safe_state_index >= 0) {
927 return drv->states[drv->safe_state_index].enter(dev,
928 drv, drv->safe_state_index);
929 } else {
930 local_irq_disable();
931 if (!acpi_idle_suspend)
932 acpi_safe_halt();
933 local_irq_enable();
934 return -EBUSY;
935 }
936 }
937
938 local_irq_disable();
939
940 if (acpi_idle_suspend) {
941 local_irq_enable();
942 cpu_relax();
943 return -EBUSY;
944 }
945
946 if (cx->entry_method != ACPI_CSTATE_FFH) {
947 current_thread_info()->status &= ~TS_POLLING;
948 /*
949 * TS_POLLING-cleared state must be visible before we test
950 * NEED_RESCHED:
951 */
952 smp_mb();
953
954 if (unlikely(need_resched())) {
955 current_thread_info()->status |= TS_POLLING;
956 local_irq_enable();
957 return -EINVAL;
958 }
959 }
960
961 acpi_unlazy_tlb(smp_processor_id());
962
963 /* Tell the scheduler that we are going deep-idle: */
964 sched_clock_idle_sleep_event();
965 /*
966 * Must be done before busmaster disable as we might need to
967 * access HPET !
968 */
969 lapic_timer_state_broadcast(pr, cx, 1);
970
971 kt1 = ktime_get_real();
972 /*
973 * disable bus master
974 * bm_check implies we need ARB_DIS
975 * !bm_check implies we need cache flush
976 * bm_control implies whether we can do ARB_DIS
977 *
978 * That leaves a case where bm_check is set and bm_control is
979 * not set. In that case we cannot do much, we enter C3
980 * without doing anything.
981 */
982 if (pr->flags.bm_check && pr->flags.bm_control) {
983 raw_spin_lock(&c3_lock);
984 c3_cpu_count++;
985 /* Disable bus master arbitration when all CPUs are in C3 */
986 if (c3_cpu_count == num_online_cpus())
987 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
988 raw_spin_unlock(&c3_lock);
989 } else if (!pr->flags.bm_check) {
990 ACPI_FLUSH_CPU_CACHE();
991 }
992
993 acpi_idle_do_entry(cx);
994
995 /* Re-enable bus master arbitration */
996 if (pr->flags.bm_check && pr->flags.bm_control) {
997 raw_spin_lock(&c3_lock);
998 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
999 c3_cpu_count--;
1000 raw_spin_unlock(&c3_lock);
1001 }
1002 kt2 = ktime_get_real();
1003 idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
1004 idle_time = idle_time_ns;
1005 do_div(idle_time, NSEC_PER_USEC);
1006
1007 /* Update device last_residency*/
1008 dev->last_residency = (int)idle_time;
1009
1010 /* Tell the scheduler how much we idled: */
1011 sched_clock_idle_wakeup_event(idle_time_ns);
1012
1013 local_irq_enable();
1014 if (cx->entry_method != ACPI_CSTATE_FFH)
1015 current_thread_info()->status |= TS_POLLING;
1016
1017 cx->usage++;
1018
1019 lapic_timer_state_broadcast(pr, cx, 0);
1020 cx->time += idle_time;
1021 return index;
1022}
1023
1024struct cpuidle_driver acpi_idle_driver = {
1025 .name = "acpi_idle",
1026 .owner = THIS_MODULE,
1027};
1028
1029/**
1030 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
1031 * device i.e. per-cpu data
1032 *
1033 * @pr: the ACPI processor
1034 */
1035static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr)
1036{
1037 int i, count = CPUIDLE_DRIVER_STATE_START;
1038 struct acpi_processor_cx *cx;
1039 struct cpuidle_state_usage *state_usage;
1040 struct cpuidle_device *dev = &pr->power.dev;
1041
1042 if (!pr->flags.power_setup_done)
1043 return -EINVAL;
1044
1045 if (pr->flags.power == 0) {
1046 return -EINVAL;
1047 }
1048
1049 dev->cpu = pr->id;
1050
1051 if (max_cstate == 0)
1052 max_cstate = 1;
1053
1054 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1055 cx = &pr->power.states[i];
1056 state_usage = &dev->states_usage[count];
1057
1058 if (!cx->valid)
1059 continue;
1060
1061#ifdef CONFIG_HOTPLUG_CPU
1062 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1063 !pr->flags.has_cst &&
1064 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1065 continue;
1066#endif
1067
1068 cpuidle_set_statedata(state_usage, cx);
1069
1070 count++;
1071 if (count == CPUIDLE_STATE_MAX)
1072 break;
1073 }
1074
1075 dev->state_count = count;
1076
1077 if (!count)
1078 return -EINVAL;
1079
1080 return 0;
1081}
1082
1083/**
1084 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
1085 * global state data i.e. idle routines
1086 *
1087 * @pr: the ACPI processor
1088 */
1089static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1090{
1091 int i, count = CPUIDLE_DRIVER_STATE_START;
1092 struct acpi_processor_cx *cx;
1093 struct cpuidle_state *state;
1094 struct cpuidle_driver *drv = &acpi_idle_driver;
1095
1096 if (!pr->flags.power_setup_done)
1097 return -EINVAL;
1098
1099 if (pr->flags.power == 0)
1100 return -EINVAL;
1101
1102 drv->safe_state_index = -1;
1103 for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1104 drv->states[i].name[0] = '\0';
1105 drv->states[i].desc[0] = '\0';
1106 }
1107
1108 if (max_cstate == 0)
1109 max_cstate = 1;
1110
1111 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1112 cx = &pr->power.states[i];
1113
1114 if (!cx->valid)
1115 continue;
1116
1117#ifdef CONFIG_HOTPLUG_CPU
1118 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1119 !pr->flags.has_cst &&
1120 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1121 continue;
1122#endif
1123
1124 state = &drv->states[count];
1125 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1126 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1127 state->exit_latency = cx->latency;
1128 state->target_residency = cx->latency * latency_factor;
1129
1130 state->flags = 0;
1131 switch (cx->type) {
1132 case ACPI_STATE_C1:
1133 if (cx->entry_method == ACPI_CSTATE_FFH)
1134 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1135
1136 state->enter = acpi_idle_enter_c1;
1137 state->enter_dead = acpi_idle_play_dead;
1138 drv->safe_state_index = count;
1139 break;
1140
1141 case ACPI_STATE_C2:
1142 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1143 state->enter = acpi_idle_enter_simple;
1144 state->enter_dead = acpi_idle_play_dead;
1145 drv->safe_state_index = count;
1146 break;
1147
1148 case ACPI_STATE_C3:
1149 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1150 state->enter = pr->flags.bm_check ?
1151 acpi_idle_enter_bm :
1152 acpi_idle_enter_simple;
1153 break;
1154 }
1155
1156 count++;
1157 if (count == CPUIDLE_STATE_MAX)
1158 break;
1159 }
1160
1161 drv->state_count = count;
1162
1163 if (!count)
1164 return -EINVAL;
1165
1166 return 0;
1167}
1168
1169int acpi_processor_hotplug(struct acpi_processor *pr)
1170{
1171 int ret = 0;
1172
1173 if (disabled_by_idle_boot_param())
1174 return 0;
1175
1176 if (!pr)
1177 return -EINVAL;
1178
1179 if (nocst) {
1180 return -ENODEV;
1181 }
1182
1183 if (!pr->flags.power_setup_done)
1184 return -ENODEV;
1185
1186 cpuidle_pause_and_lock();
1187 cpuidle_disable_device(&pr->power.dev);
1188 acpi_processor_get_power_info(pr);
1189 if (pr->flags.power) {
1190 acpi_processor_setup_cpuidle_cx(pr);
1191 ret = cpuidle_enable_device(&pr->power.dev);
1192 }
1193 cpuidle_resume_and_unlock();
1194
1195 return ret;
1196}
1197
1198int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1199{
1200 int cpu;
1201 struct acpi_processor *_pr;
1202
1203 if (disabled_by_idle_boot_param())
1204 return 0;
1205
1206 if (!pr)
1207 return -EINVAL;
1208
1209 if (nocst)
1210 return -ENODEV;
1211
1212 if (!pr->flags.power_setup_done)
1213 return -ENODEV;
1214
1215 /*
1216 * FIXME: Design the ACPI notification to make it once per
1217 * system instead of once per-cpu. This condition is a hack
1218 * to make the code that updates C-States be called once.
1219 */
1220
1221 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1222
1223 cpuidle_pause_and_lock();
1224 /* Protect against cpu-hotplug */
1225 get_online_cpus();
1226
1227 /* Disable all cpuidle devices */
1228 for_each_online_cpu(cpu) {
1229 _pr = per_cpu(processors, cpu);
1230 if (!_pr || !_pr->flags.power_setup_done)
1231 continue;
1232 cpuidle_disable_device(&_pr->power.dev);
1233 }
1234
1235 /* Populate Updated C-state information */
1236 acpi_processor_setup_cpuidle_states(pr);
1237
1238 /* Enable all cpuidle devices */
1239 for_each_online_cpu(cpu) {
1240 _pr = per_cpu(processors, cpu);
1241 if (!_pr || !_pr->flags.power_setup_done)
1242 continue;
1243 acpi_processor_get_power_info(_pr);
1244 if (_pr->flags.power) {
1245 acpi_processor_setup_cpuidle_cx(_pr);
1246 cpuidle_enable_device(&_pr->power.dev);
1247 }
1248 }
1249 put_online_cpus();
1250 cpuidle_resume_and_unlock();
1251 }
1252
1253 return 0;
1254}
1255
1256static int acpi_processor_registered;
1257
1258int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1259 struct acpi_device *device)
1260{
1261 acpi_status status = 0;
1262 int retval;
1263 static int first_run;
1264
1265 if (disabled_by_idle_boot_param())
1266 return 0;
1267
1268 if (!first_run) {
1269 dmi_check_system(processor_power_dmi_table);
1270 max_cstate = acpi_processor_cstate_check(max_cstate);
1271 if (max_cstate < ACPI_C_STATES_MAX)
1272 printk(KERN_NOTICE
1273 "ACPI: processor limited to max C-state %d\n",
1274 max_cstate);
1275 first_run++;
1276 }
1277
1278 if (!pr)
1279 return -EINVAL;
1280
1281 if (acpi_gbl_FADT.cst_control && !nocst) {
1282 status =
1283 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1284 if (ACPI_FAILURE(status)) {
1285 ACPI_EXCEPTION((AE_INFO, status,
1286 "Notifying BIOS of _CST ability failed"));
1287 }
1288 }
1289
1290 acpi_processor_get_power_info(pr);
1291 pr->flags.power_setup_done = 1;
1292
1293 /*
1294 * Install the idle handler if processor power management is supported.
1295 * Note that we use previously set idle handler will be used on
1296 * platforms that only support C1.
1297 */
1298 if (pr->flags.power) {
1299 /* Register acpi_idle_driver if not already registered */
1300 if (!acpi_processor_registered) {
1301 acpi_processor_setup_cpuidle_states(pr);
1302 retval = cpuidle_register_driver(&acpi_idle_driver);
1303 if (retval)
1304 return retval;
1305 printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1306 acpi_idle_driver.name);
1307 }
1308 /* Register per-cpu cpuidle_device. Cpuidle driver
1309 * must already be registered before registering device
1310 */
1311 acpi_processor_setup_cpuidle_cx(pr);
1312 retval = cpuidle_register_device(&pr->power.dev);
1313 if (retval) {
1314 if (acpi_processor_registered == 0)
1315 cpuidle_unregister_driver(&acpi_idle_driver);
1316 return retval;
1317 }
1318 acpi_processor_registered++;
1319 }
1320 return 0;
1321}
1322
1323int acpi_processor_power_exit(struct acpi_processor *pr,
1324 struct acpi_device *device)
1325{
1326 if (disabled_by_idle_boot_param())
1327 return 0;
1328
1329 if (pr->flags.power) {
1330 cpuidle_unregister_device(&pr->power.dev);
1331 acpi_processor_registered--;
1332 if (acpi_processor_registered == 0)
1333 cpuidle_unregister_driver(&acpi_idle_driver);
1334 }
1335
1336 pr->flags.power_setup_done = 0;
1337 return 0;
1338}
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/clockchips.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
54ACPI_MODULE_NAME("processor_idle");
55
56static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
57module_param(max_cstate, uint, 0000);
58static unsigned int nocst __read_mostly;
59module_param(nocst, uint, 0000);
60static int bm_check_disable __read_mostly;
61module_param(bm_check_disable, uint, 0000);
62
63static unsigned int latency_factor __read_mostly = 2;
64module_param(latency_factor, uint, 0644);
65
66static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
67
68static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
69 acpi_cstate);
70
71static 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 */
83static 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
97static 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 */
118static 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 */
134static 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
157static void __lapic_timer_propagate_broadcast(void *arg)
158{
159 struct acpi_processor *pr = (struct acpi_processor *) arg;
160 unsigned long reason;
161
162 reason = pr->power.timer_broadcast_on_state < INT_MAX ?
163 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
164
165 clockevents_notify(reason, &pr->id);
166}
167
168static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
169{
170 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
171 (void *)pr, 1);
172}
173
174/* Power(C) State timer broadcast control */
175static void lapic_timer_state_broadcast(struct acpi_processor *pr,
176 struct acpi_processor_cx *cx,
177 int broadcast)
178{
179 int state = cx - pr->power.states;
180
181 if (state >= pr->power.timer_broadcast_on_state) {
182 unsigned long reason;
183
184 reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
185 CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
186 clockevents_notify(reason, &pr->id);
187 }
188}
189
190#else
191
192static void lapic_timer_check_state(int state, struct acpi_processor *pr,
193 struct acpi_processor_cx *cstate) { }
194static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
195static void lapic_timer_state_broadcast(struct acpi_processor *pr,
196 struct acpi_processor_cx *cx,
197 int broadcast)
198{
199}
200
201#endif
202
203#ifdef CONFIG_PM_SLEEP
204static u32 saved_bm_rld;
205
206static int acpi_processor_suspend(void)
207{
208 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
209 return 0;
210}
211
212static void acpi_processor_resume(void)
213{
214 u32 resumed_bm_rld = 0;
215
216 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
217 if (resumed_bm_rld == saved_bm_rld)
218 return;
219
220 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
221}
222
223static struct syscore_ops acpi_processor_syscore_ops = {
224 .suspend = acpi_processor_suspend,
225 .resume = acpi_processor_resume,
226};
227
228void acpi_processor_syscore_init(void)
229{
230 register_syscore_ops(&acpi_processor_syscore_ops);
231}
232
233void acpi_processor_syscore_exit(void)
234{
235 unregister_syscore_ops(&acpi_processor_syscore_ops);
236}
237#endif /* CONFIG_PM_SLEEP */
238
239#if defined(CONFIG_X86)
240static void tsc_check_state(int state)
241{
242 switch (boot_cpu_data.x86_vendor) {
243 case X86_VENDOR_AMD:
244 case X86_VENDOR_INTEL:
245 /*
246 * AMD Fam10h TSC will tick in all
247 * C/P/S0/S1 states when this bit is set.
248 */
249 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
250 return;
251
252 /*FALL THROUGH*/
253 default:
254 /* TSC could halt in idle, so notify users */
255 if (state > ACPI_STATE_C1)
256 mark_tsc_unstable("TSC halts in idle");
257 }
258}
259#else
260static void tsc_check_state(int state) { return; }
261#endif
262
263static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
264{
265
266 if (!pr->pblk)
267 return -ENODEV;
268
269 /* if info is obtained from pblk/fadt, type equals state */
270 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
271 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
272
273#ifndef CONFIG_HOTPLUG_CPU
274 /*
275 * Check for P_LVL2_UP flag before entering C2 and above on
276 * an SMP system.
277 */
278 if ((num_online_cpus() > 1) &&
279 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
280 return -ENODEV;
281#endif
282
283 /* determine C2 and C3 address from pblk */
284 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
285 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
286
287 /* determine latencies from FADT */
288 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
289 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
290
291 /*
292 * FADT specified C2 latency must be less than or equal to
293 * 100 microseconds.
294 */
295 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
296 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
297 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
298 /* invalidate C2 */
299 pr->power.states[ACPI_STATE_C2].address = 0;
300 }
301
302 /*
303 * FADT supplied C3 latency must be less than or equal to
304 * 1000 microseconds.
305 */
306 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
307 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
308 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
309 /* invalidate C3 */
310 pr->power.states[ACPI_STATE_C3].address = 0;
311 }
312
313 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
314 "lvl2[0x%08x] lvl3[0x%08x]\n",
315 pr->power.states[ACPI_STATE_C2].address,
316 pr->power.states[ACPI_STATE_C3].address));
317
318 return 0;
319}
320
321static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
322{
323 if (!pr->power.states[ACPI_STATE_C1].valid) {
324 /* set the first C-State to C1 */
325 /* all processors need to support C1 */
326 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
327 pr->power.states[ACPI_STATE_C1].valid = 1;
328 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
329 }
330 /* the C0 state only exists as a filler in our array */
331 pr->power.states[ACPI_STATE_C0].valid = 1;
332 return 0;
333}
334
335static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
336{
337 acpi_status status = 0;
338 u64 count;
339 int current_count;
340 int i;
341 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
342 union acpi_object *cst;
343
344
345 if (nocst)
346 return -ENODEV;
347
348 current_count = 0;
349
350 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
351 if (ACPI_FAILURE(status)) {
352 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
353 return -ENODEV;
354 }
355
356 cst = buffer.pointer;
357
358 /* There must be at least 2 elements */
359 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
360 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
361 status = -EFAULT;
362 goto end;
363 }
364
365 count = cst->package.elements[0].integer.value;
366
367 /* Validate number of power states. */
368 if (count < 1 || count != cst->package.count - 1) {
369 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
370 status = -EFAULT;
371 goto end;
372 }
373
374 /* Tell driver that at least _CST is supported. */
375 pr->flags.has_cst = 1;
376
377 for (i = 1; i <= count; i++) {
378 union acpi_object *element;
379 union acpi_object *obj;
380 struct acpi_power_register *reg;
381 struct acpi_processor_cx cx;
382
383 memset(&cx, 0, sizeof(cx));
384
385 element = &(cst->package.elements[i]);
386 if (element->type != ACPI_TYPE_PACKAGE)
387 continue;
388
389 if (element->package.count != 4)
390 continue;
391
392 obj = &(element->package.elements[0]);
393
394 if (obj->type != ACPI_TYPE_BUFFER)
395 continue;
396
397 reg = (struct acpi_power_register *)obj->buffer.pointer;
398
399 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
400 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
401 continue;
402
403 /* There should be an easy way to extract an integer... */
404 obj = &(element->package.elements[1]);
405 if (obj->type != ACPI_TYPE_INTEGER)
406 continue;
407
408 cx.type = obj->integer.value;
409 /*
410 * Some buggy BIOSes won't list C1 in _CST -
411 * Let acpi_processor_get_power_info_default() handle them later
412 */
413 if (i == 1 && cx.type != ACPI_STATE_C1)
414 current_count++;
415
416 cx.address = reg->address;
417 cx.index = current_count + 1;
418
419 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
420 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
421 if (acpi_processor_ffh_cstate_probe
422 (pr->id, &cx, reg) == 0) {
423 cx.entry_method = ACPI_CSTATE_FFH;
424 } else if (cx.type == ACPI_STATE_C1) {
425 /*
426 * C1 is a special case where FIXED_HARDWARE
427 * can be handled in non-MWAIT way as well.
428 * In that case, save this _CST entry info.
429 * Otherwise, ignore this info and continue.
430 */
431 cx.entry_method = ACPI_CSTATE_HALT;
432 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
433 } else {
434 continue;
435 }
436 if (cx.type == ACPI_STATE_C1 &&
437 (boot_option_idle_override == IDLE_NOMWAIT)) {
438 /*
439 * In most cases the C1 space_id obtained from
440 * _CST object is FIXED_HARDWARE access mode.
441 * But when the option of idle=halt is added,
442 * the entry_method type should be changed from
443 * CSTATE_FFH to CSTATE_HALT.
444 * When the option of idle=nomwait is added,
445 * the C1 entry_method type should be
446 * CSTATE_HALT.
447 */
448 cx.entry_method = ACPI_CSTATE_HALT;
449 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
450 }
451 } else {
452 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
453 cx.address);
454 }
455
456 if (cx.type == ACPI_STATE_C1) {
457 cx.valid = 1;
458 }
459
460 obj = &(element->package.elements[2]);
461 if (obj->type != ACPI_TYPE_INTEGER)
462 continue;
463
464 cx.latency = obj->integer.value;
465
466 obj = &(element->package.elements[3]);
467 if (obj->type != ACPI_TYPE_INTEGER)
468 continue;
469
470 current_count++;
471 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
472
473 /*
474 * We support total ACPI_PROCESSOR_MAX_POWER - 1
475 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
476 */
477 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
478 printk(KERN_WARNING
479 "Limiting number of power states to max (%d)\n",
480 ACPI_PROCESSOR_MAX_POWER);
481 printk(KERN_WARNING
482 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
483 break;
484 }
485 }
486
487 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
488 current_count));
489
490 /* Validate number of power states discovered */
491 if (current_count < 2)
492 status = -EFAULT;
493
494 end:
495 kfree(buffer.pointer);
496
497 return status;
498}
499
500static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
501 struct acpi_processor_cx *cx)
502{
503 static int bm_check_flag = -1;
504 static int bm_control_flag = -1;
505
506
507 if (!cx->address)
508 return;
509
510 /*
511 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
512 * DMA transfers are used by any ISA device to avoid livelock.
513 * Note that we could disable Type-F DMA (as recommended by
514 * the erratum), but this is known to disrupt certain ISA
515 * devices thus we take the conservative approach.
516 */
517 else if (errata.piix4.fdma) {
518 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
519 "C3 not supported on PIIX4 with Type-F DMA\n"));
520 return;
521 }
522
523 /* All the logic here assumes flags.bm_check is same across all CPUs */
524 if (bm_check_flag == -1) {
525 /* Determine whether bm_check is needed based on CPU */
526 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
527 bm_check_flag = pr->flags.bm_check;
528 bm_control_flag = pr->flags.bm_control;
529 } else {
530 pr->flags.bm_check = bm_check_flag;
531 pr->flags.bm_control = bm_control_flag;
532 }
533
534 if (pr->flags.bm_check) {
535 if (!pr->flags.bm_control) {
536 if (pr->flags.has_cst != 1) {
537 /* bus mastering control is necessary */
538 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
539 "C3 support requires BM control\n"));
540 return;
541 } else {
542 /* Here we enter C3 without bus mastering */
543 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
544 "C3 support without BM control\n"));
545 }
546 }
547 } else {
548 /*
549 * WBINVD should be set in fadt, for C3 state to be
550 * supported on when bm_check is not required.
551 */
552 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
553 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
554 "Cache invalidation should work properly"
555 " for C3 to be enabled on SMP systems\n"));
556 return;
557 }
558 }
559
560 /*
561 * Otherwise we've met all of our C3 requirements.
562 * Normalize the C3 latency to expidite policy. Enable
563 * checking of bus mastering status (bm_check) so we can
564 * use this in our C3 policy
565 */
566 cx->valid = 1;
567
568 /*
569 * On older chipsets, BM_RLD needs to be set
570 * in order for Bus Master activity to wake the
571 * system from C3. Newer chipsets handle DMA
572 * during C3 automatically and BM_RLD is a NOP.
573 * In either case, the proper way to
574 * handle BM_RLD is to set it and leave it set.
575 */
576 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
577
578 return;
579}
580
581static int acpi_processor_power_verify(struct acpi_processor *pr)
582{
583 unsigned int i;
584 unsigned int working = 0;
585
586 pr->power.timer_broadcast_on_state = INT_MAX;
587
588 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
589 struct acpi_processor_cx *cx = &pr->power.states[i];
590
591 switch (cx->type) {
592 case ACPI_STATE_C1:
593 cx->valid = 1;
594 break;
595
596 case ACPI_STATE_C2:
597 if (!cx->address)
598 break;
599 cx->valid = 1;
600 break;
601
602 case ACPI_STATE_C3:
603 acpi_processor_power_verify_c3(pr, cx);
604 break;
605 }
606 if (!cx->valid)
607 continue;
608
609 lapic_timer_check_state(i, pr, cx);
610 tsc_check_state(cx->type);
611 working++;
612 }
613
614 lapic_timer_propagate_broadcast(pr);
615
616 return (working);
617}
618
619static int acpi_processor_get_power_info(struct acpi_processor *pr)
620{
621 unsigned int i;
622 int result;
623
624
625 /* NOTE: the idle thread may not be running while calling
626 * this function */
627
628 /* Zero initialize all the C-states info. */
629 memset(pr->power.states, 0, sizeof(pr->power.states));
630
631 result = acpi_processor_get_power_info_cst(pr);
632 if (result == -ENODEV)
633 result = acpi_processor_get_power_info_fadt(pr);
634
635 if (result)
636 return result;
637
638 acpi_processor_get_power_info_default(pr);
639
640 pr->power.count = acpi_processor_power_verify(pr);
641
642 /*
643 * if one state of type C2 or C3 is available, mark this
644 * CPU as being "idle manageable"
645 */
646 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
647 if (pr->power.states[i].valid) {
648 pr->power.count = i;
649 if (pr->power.states[i].type >= ACPI_STATE_C2)
650 pr->flags.power = 1;
651 }
652 }
653
654 return 0;
655}
656
657/**
658 * acpi_idle_bm_check - checks if bus master activity was detected
659 */
660static int acpi_idle_bm_check(void)
661{
662 u32 bm_status = 0;
663
664 if (bm_check_disable)
665 return 0;
666
667 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
668 if (bm_status)
669 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
670 /*
671 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
672 * the true state of bus mastering activity; forcing us to
673 * manually check the BMIDEA bit of each IDE channel.
674 */
675 else if (errata.piix4.bmisx) {
676 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
677 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
678 bm_status = 1;
679 }
680 return bm_status;
681}
682
683/**
684 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
685 * @cx: cstate data
686 *
687 * Caller disables interrupt before call and enables interrupt after return.
688 */
689static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
690{
691 /* Don't trace irqs off for idle */
692 stop_critical_timings();
693 if (cx->entry_method == ACPI_CSTATE_FFH) {
694 /* Call into architectural FFH based C-state */
695 acpi_processor_ffh_cstate_enter(cx);
696 } else if (cx->entry_method == ACPI_CSTATE_HALT) {
697 acpi_safe_halt();
698 } else {
699 /* IO port based C-state */
700 inb(cx->address);
701 /* Dummy wait op - must do something useless after P_LVL2 read
702 because chipsets cannot guarantee that STPCLK# signal
703 gets asserted in time to freeze execution properly. */
704 inl(acpi_gbl_FADT.xpm_timer_block.address);
705 }
706 start_critical_timings();
707}
708
709/**
710 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
711 * @dev: the target CPU
712 * @drv: cpuidle driver containing cpuidle state info
713 * @index: index of target state
714 *
715 * This is equivalent to the HALT instruction.
716 */
717static int acpi_idle_enter_c1(struct cpuidle_device *dev,
718 struct cpuidle_driver *drv, int index)
719{
720 struct acpi_processor *pr;
721 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
722
723 pr = __this_cpu_read(processors);
724
725 if (unlikely(!pr))
726 return -EINVAL;
727
728 lapic_timer_state_broadcast(pr, cx, 1);
729 acpi_idle_do_entry(cx);
730
731 lapic_timer_state_broadcast(pr, cx, 0);
732
733 return index;
734}
735
736
737/**
738 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
739 * @dev: the target CPU
740 * @index: the index of suggested state
741 */
742static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
743{
744 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
745
746 ACPI_FLUSH_CPU_CACHE();
747
748 while (1) {
749
750 if (cx->entry_method == ACPI_CSTATE_HALT)
751 safe_halt();
752 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
753 inb(cx->address);
754 /* See comment in acpi_idle_do_entry() */
755 inl(acpi_gbl_FADT.xpm_timer_block.address);
756 } else
757 return -ENODEV;
758 }
759
760 /* Never reached */
761 return 0;
762}
763
764/**
765 * acpi_idle_enter_simple - enters an ACPI state without BM handling
766 * @dev: the target CPU
767 * @drv: cpuidle driver with cpuidle state information
768 * @index: the index of suggested state
769 */
770static int acpi_idle_enter_simple(struct cpuidle_device *dev,
771 struct cpuidle_driver *drv, int index)
772{
773 struct acpi_processor *pr;
774 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
775
776 pr = __this_cpu_read(processors);
777
778 if (unlikely(!pr))
779 return -EINVAL;
780
781#ifdef CONFIG_HOTPLUG_CPU
782 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
783 !pr->flags.has_cst &&
784 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
785 return acpi_idle_enter_c1(dev, drv, CPUIDLE_DRIVER_STATE_START);
786#endif
787
788 /*
789 * Must be done before busmaster disable as we might need to
790 * access HPET !
791 */
792 lapic_timer_state_broadcast(pr, cx, 1);
793
794 if (cx->type == ACPI_STATE_C3)
795 ACPI_FLUSH_CPU_CACHE();
796
797 /* Tell the scheduler that we are going deep-idle: */
798 sched_clock_idle_sleep_event();
799 acpi_idle_do_entry(cx);
800
801 sched_clock_idle_wakeup_event(0);
802
803 lapic_timer_state_broadcast(pr, cx, 0);
804 return index;
805}
806
807static int c3_cpu_count;
808static DEFINE_RAW_SPINLOCK(c3_lock);
809
810/**
811 * acpi_idle_enter_bm - enters C3 with proper BM handling
812 * @dev: the target CPU
813 * @drv: cpuidle driver containing state data
814 * @index: the index of suggested state
815 *
816 * If BM is detected, the deepest non-C3 idle state is entered instead.
817 */
818static int acpi_idle_enter_bm(struct cpuidle_device *dev,
819 struct cpuidle_driver *drv, int index)
820{
821 struct acpi_processor *pr;
822 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
823
824 pr = __this_cpu_read(processors);
825
826 if (unlikely(!pr))
827 return -EINVAL;
828
829#ifdef CONFIG_HOTPLUG_CPU
830 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
831 !pr->flags.has_cst &&
832 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
833 return acpi_idle_enter_c1(dev, drv, CPUIDLE_DRIVER_STATE_START);
834#endif
835
836 if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
837 if (drv->safe_state_index >= 0) {
838 return drv->states[drv->safe_state_index].enter(dev,
839 drv, drv->safe_state_index);
840 } else {
841 acpi_safe_halt();
842 return -EBUSY;
843 }
844 }
845
846 acpi_unlazy_tlb(smp_processor_id());
847
848 /* Tell the scheduler that we are going deep-idle: */
849 sched_clock_idle_sleep_event();
850 /*
851 * Must be done before busmaster disable as we might need to
852 * access HPET !
853 */
854 lapic_timer_state_broadcast(pr, cx, 1);
855
856 /*
857 * disable bus master
858 * bm_check implies we need ARB_DIS
859 * !bm_check implies we need cache flush
860 * bm_control implies whether we can do ARB_DIS
861 *
862 * That leaves a case where bm_check is set and bm_control is
863 * not set. In that case we cannot do much, we enter C3
864 * without doing anything.
865 */
866 if (pr->flags.bm_check && pr->flags.bm_control) {
867 raw_spin_lock(&c3_lock);
868 c3_cpu_count++;
869 /* Disable bus master arbitration when all CPUs are in C3 */
870 if (c3_cpu_count == num_online_cpus())
871 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
872 raw_spin_unlock(&c3_lock);
873 } else if (!pr->flags.bm_check) {
874 ACPI_FLUSH_CPU_CACHE();
875 }
876
877 acpi_idle_do_entry(cx);
878
879 /* Re-enable bus master arbitration */
880 if (pr->flags.bm_check && pr->flags.bm_control) {
881 raw_spin_lock(&c3_lock);
882 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
883 c3_cpu_count--;
884 raw_spin_unlock(&c3_lock);
885 }
886
887 sched_clock_idle_wakeup_event(0);
888
889 lapic_timer_state_broadcast(pr, cx, 0);
890 return index;
891}
892
893struct cpuidle_driver acpi_idle_driver = {
894 .name = "acpi_idle",
895 .owner = THIS_MODULE,
896};
897
898/**
899 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
900 * device i.e. per-cpu data
901 *
902 * @pr: the ACPI processor
903 * @dev : the cpuidle device
904 */
905static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
906 struct cpuidle_device *dev)
907{
908 int i, count = CPUIDLE_DRIVER_STATE_START;
909 struct acpi_processor_cx *cx;
910
911 if (!pr->flags.power_setup_done)
912 return -EINVAL;
913
914 if (pr->flags.power == 0) {
915 return -EINVAL;
916 }
917
918 if (!dev)
919 return -EINVAL;
920
921 dev->cpu = pr->id;
922
923 if (max_cstate == 0)
924 max_cstate = 1;
925
926 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
927 cx = &pr->power.states[i];
928
929 if (!cx->valid)
930 continue;
931
932 per_cpu(acpi_cstate[count], dev->cpu) = cx;
933
934 count++;
935 if (count == CPUIDLE_STATE_MAX)
936 break;
937 }
938
939 if (!count)
940 return -EINVAL;
941
942 return 0;
943}
944
945/**
946 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
947 * global state data i.e. idle routines
948 *
949 * @pr: the ACPI processor
950 */
951static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
952{
953 int i, count = CPUIDLE_DRIVER_STATE_START;
954 struct acpi_processor_cx *cx;
955 struct cpuidle_state *state;
956 struct cpuidle_driver *drv = &acpi_idle_driver;
957
958 if (!pr->flags.power_setup_done)
959 return -EINVAL;
960
961 if (pr->flags.power == 0)
962 return -EINVAL;
963
964 drv->safe_state_index = -1;
965 for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
966 drv->states[i].name[0] = '\0';
967 drv->states[i].desc[0] = '\0';
968 }
969
970 if (max_cstate == 0)
971 max_cstate = 1;
972
973 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
974 cx = &pr->power.states[i];
975
976 if (!cx->valid)
977 continue;
978
979 state = &drv->states[count];
980 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
981 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
982 state->exit_latency = cx->latency;
983 state->target_residency = cx->latency * latency_factor;
984
985 state->flags = 0;
986 switch (cx->type) {
987 case ACPI_STATE_C1:
988 if (cx->entry_method == ACPI_CSTATE_FFH)
989 state->flags |= CPUIDLE_FLAG_TIME_VALID;
990
991 state->enter = acpi_idle_enter_c1;
992 state->enter_dead = acpi_idle_play_dead;
993 drv->safe_state_index = count;
994 break;
995
996 case ACPI_STATE_C2:
997 state->flags |= CPUIDLE_FLAG_TIME_VALID;
998 state->enter = acpi_idle_enter_simple;
999 state->enter_dead = acpi_idle_play_dead;
1000 drv->safe_state_index = count;
1001 break;
1002
1003 case ACPI_STATE_C3:
1004 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1005 state->enter = pr->flags.bm_check ?
1006 acpi_idle_enter_bm :
1007 acpi_idle_enter_simple;
1008 break;
1009 }
1010
1011 count++;
1012 if (count == CPUIDLE_STATE_MAX)
1013 break;
1014 }
1015
1016 drv->state_count = count;
1017
1018 if (!count)
1019 return -EINVAL;
1020
1021 return 0;
1022}
1023
1024int acpi_processor_hotplug(struct acpi_processor *pr)
1025{
1026 int ret = 0;
1027 struct cpuidle_device *dev;
1028
1029 if (disabled_by_idle_boot_param())
1030 return 0;
1031
1032 if (nocst)
1033 return -ENODEV;
1034
1035 if (!pr->flags.power_setup_done)
1036 return -ENODEV;
1037
1038 dev = per_cpu(acpi_cpuidle_device, pr->id);
1039 cpuidle_pause_and_lock();
1040 cpuidle_disable_device(dev);
1041 acpi_processor_get_power_info(pr);
1042 if (pr->flags.power) {
1043 acpi_processor_setup_cpuidle_cx(pr, dev);
1044 ret = cpuidle_enable_device(dev);
1045 }
1046 cpuidle_resume_and_unlock();
1047
1048 return ret;
1049}
1050
1051int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1052{
1053 int cpu;
1054 struct acpi_processor *_pr;
1055 struct cpuidle_device *dev;
1056
1057 if (disabled_by_idle_boot_param())
1058 return 0;
1059
1060 if (nocst)
1061 return -ENODEV;
1062
1063 if (!pr->flags.power_setup_done)
1064 return -ENODEV;
1065
1066 /*
1067 * FIXME: Design the ACPI notification to make it once per
1068 * system instead of once per-cpu. This condition is a hack
1069 * to make the code that updates C-States be called once.
1070 */
1071
1072 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1073
1074 cpuidle_pause_and_lock();
1075 /* Protect against cpu-hotplug */
1076 get_online_cpus();
1077
1078 /* Disable all cpuidle devices */
1079 for_each_online_cpu(cpu) {
1080 _pr = per_cpu(processors, cpu);
1081 if (!_pr || !_pr->flags.power_setup_done)
1082 continue;
1083 dev = per_cpu(acpi_cpuidle_device, cpu);
1084 cpuidle_disable_device(dev);
1085 }
1086
1087 /* Populate Updated C-state information */
1088 acpi_processor_get_power_info(pr);
1089 acpi_processor_setup_cpuidle_states(pr);
1090
1091 /* Enable all cpuidle devices */
1092 for_each_online_cpu(cpu) {
1093 _pr = per_cpu(processors, cpu);
1094 if (!_pr || !_pr->flags.power_setup_done)
1095 continue;
1096 acpi_processor_get_power_info(_pr);
1097 if (_pr->flags.power) {
1098 dev = per_cpu(acpi_cpuidle_device, cpu);
1099 acpi_processor_setup_cpuidle_cx(_pr, dev);
1100 cpuidle_enable_device(dev);
1101 }
1102 }
1103 put_online_cpus();
1104 cpuidle_resume_and_unlock();
1105 }
1106
1107 return 0;
1108}
1109
1110static int acpi_processor_registered;
1111
1112int acpi_processor_power_init(struct acpi_processor *pr)
1113{
1114 acpi_status status = 0;
1115 int retval;
1116 struct cpuidle_device *dev;
1117 static int first_run;
1118
1119 if (disabled_by_idle_boot_param())
1120 return 0;
1121
1122 if (!first_run) {
1123 dmi_check_system(processor_power_dmi_table);
1124 max_cstate = acpi_processor_cstate_check(max_cstate);
1125 if (max_cstate < ACPI_C_STATES_MAX)
1126 printk(KERN_NOTICE
1127 "ACPI: processor limited to max C-state %d\n",
1128 max_cstate);
1129 first_run++;
1130 }
1131
1132 if (acpi_gbl_FADT.cst_control && !nocst) {
1133 status =
1134 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1135 if (ACPI_FAILURE(status)) {
1136 ACPI_EXCEPTION((AE_INFO, status,
1137 "Notifying BIOS of _CST ability failed"));
1138 }
1139 }
1140
1141 acpi_processor_get_power_info(pr);
1142 pr->flags.power_setup_done = 1;
1143
1144 /*
1145 * Install the idle handler if processor power management is supported.
1146 * Note that we use previously set idle handler will be used on
1147 * platforms that only support C1.
1148 */
1149 if (pr->flags.power) {
1150 /* Register acpi_idle_driver if not already registered */
1151 if (!acpi_processor_registered) {
1152 acpi_processor_setup_cpuidle_states(pr);
1153 retval = cpuidle_register_driver(&acpi_idle_driver);
1154 if (retval)
1155 return retval;
1156 printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1157 acpi_idle_driver.name);
1158 }
1159
1160 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1161 if (!dev)
1162 return -ENOMEM;
1163 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1164
1165 acpi_processor_setup_cpuidle_cx(pr, dev);
1166
1167 /* Register per-cpu cpuidle_device. Cpuidle driver
1168 * must already be registered before registering device
1169 */
1170 retval = cpuidle_register_device(dev);
1171 if (retval) {
1172 if (acpi_processor_registered == 0)
1173 cpuidle_unregister_driver(&acpi_idle_driver);
1174 return retval;
1175 }
1176 acpi_processor_registered++;
1177 }
1178 return 0;
1179}
1180
1181int acpi_processor_power_exit(struct acpi_processor *pr)
1182{
1183 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1184
1185 if (disabled_by_idle_boot_param())
1186 return 0;
1187
1188 if (pr->flags.power) {
1189 cpuidle_unregister_device(dev);
1190 acpi_processor_registered--;
1191 if (acpi_processor_registered == 0)
1192 cpuidle_unregister_driver(&acpi_idle_driver);
1193 }
1194
1195 pr->flags.power_setup_done = 0;
1196 return 0;
1197}