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