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