ACPI / video: Quirk initial backlight level 0
[linux-3.10.git] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/module.h>
32 #include <linux/acpi.h>
33 #include <linux/dmi.h>
34 #include <linux/sched.h>       /* need_resched() */
35 #include <linux/clockchips.h>
36 #include <linux/cpuidle.h>
37 #include <linux/syscore_ops.h>
38
39 /*
40  * Include the apic definitions for x86 to have the APIC timer related defines
41  * available also for UP (on SMP it gets magically included via linux/smp.h).
42  * asm/acpi.h is not an option, as it would require more include magic. Also
43  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
44  */
45 #ifdef CONFIG_X86
46 #include <asm/apic.h>
47 #endif
48
49 #include <acpi/acpi_bus.h>
50 #include <acpi/processor.h>
51
52 #define PREFIX "ACPI: "
53
54 #define ACPI_PROCESSOR_CLASS            "processor"
55 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
56 ACPI_MODULE_NAME("processor_idle");
57
58 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
59 module_param(max_cstate, uint, 0000);
60 static unsigned int nocst __read_mostly;
61 module_param(nocst, uint, 0000);
62 static int bm_check_disable __read_mostly;
63 module_param(bm_check_disable, uint, 0000);
64
65 static unsigned int latency_factor __read_mostly = 2;
66 module_param(latency_factor, uint, 0644);
67
68 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
69
70 static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
71                                                                 acpi_cstate);
72
73 static int disabled_by_idle_boot_param(void)
74 {
75         return boot_option_idle_override == IDLE_POLL ||
76                 boot_option_idle_override == IDLE_HALT;
77 }
78
79 /*
80  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
81  * For now disable this. Probably a bug somewhere else.
82  *
83  * To skip this limit, boot/load with a large max_cstate limit.
84  */
85 static int set_max_cstate(const struct dmi_system_id *id)
86 {
87         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
88                 return 0;
89
90         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
91                " Override with \"processor.max_cstate=%d\"\n", id->ident,
92                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
93
94         max_cstate = (long)id->driver_data;
95
96         return 0;
97 }
98
99 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
100    callers to only run once -AK */
101 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
102         { set_max_cstate, "Clevo 5600D", {
103           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
104           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
105          (void *)2},
106         { set_max_cstate, "Pavilion zv5000", {
107           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
108           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
109          (void *)1},
110         { set_max_cstate, "Asus L8400B", {
111           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
112           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
113          (void *)1},
114         {},
115 };
116
117
118 /*
119  * Callers should disable interrupts before the call and enable
120  * interrupts after return.
121  */
122 static void acpi_safe_halt(void)
123 {
124         if (!tif_need_resched()) {
125                 safe_halt();
126                 local_irq_disable();
127         }
128 }
129
130 #ifdef ARCH_APICTIMER_STOPS_ON_C3
131
132 /*
133  * Some BIOS implementations switch to C3 in the published C2 state.
134  * This seems to be a common problem on AMD boxen, but other vendors
135  * are affected too. We pick the most conservative approach: we assume
136  * that the local APIC stops in both C2 and C3.
137  */
138 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
139                                    struct acpi_processor_cx *cx)
140 {
141         struct acpi_processor_power *pwr = &pr->power;
142         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
143
144         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
145                 return;
146
147         if (amd_e400_c1e_detected)
148                 type = ACPI_STATE_C1;
149
150         /*
151          * Check, if one of the previous states already marked the lapic
152          * unstable
153          */
154         if (pwr->timer_broadcast_on_state < state)
155                 return;
156
157         if (cx->type >= type)
158                 pr->power.timer_broadcast_on_state = state;
159 }
160
161 static void __lapic_timer_propagate_broadcast(void *arg)
162 {
163         struct acpi_processor *pr = (struct acpi_processor *) arg;
164         unsigned long reason;
165
166         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
167                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
168
169         clockevents_notify(reason, &pr->id);
170 }
171
172 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
173 {
174         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
175                                  (void *)pr, 1);
176 }
177
178 /* Power(C) State timer broadcast control */
179 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
180                                        struct acpi_processor_cx *cx,
181                                        int broadcast)
182 {
183         int state = cx - pr->power.states;
184
185         if (state >= pr->power.timer_broadcast_on_state) {
186                 unsigned long reason;
187
188                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
189                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
190                 clockevents_notify(reason, &pr->id);
191         }
192 }
193
194 #else
195
196 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
197                                    struct acpi_processor_cx *cstate) { }
198 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
199 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
200                                        struct acpi_processor_cx *cx,
201                                        int broadcast)
202 {
203 }
204
205 #endif
206
207 #ifdef CONFIG_PM_SLEEP
208 static u32 saved_bm_rld;
209
210 int acpi_processor_suspend(void)
211 {
212         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
213         return 0;
214 }
215
216 void acpi_processor_resume(void)
217 {
218         u32 resumed_bm_rld;
219
220         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
221         if (resumed_bm_rld == saved_bm_rld)
222                 return;
223
224         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
225 }
226
227 static struct syscore_ops acpi_processor_syscore_ops = {
228         .suspend = acpi_processor_suspend,
229         .resume = acpi_processor_resume,
230 };
231
232 void acpi_processor_syscore_init(void)
233 {
234         register_syscore_ops(&acpi_processor_syscore_ops);
235 }
236
237 void acpi_processor_syscore_exit(void)
238 {
239         unregister_syscore_ops(&acpi_processor_syscore_ops);
240 }
241 #endif /* CONFIG_PM_SLEEP */
242
243 #if defined(CONFIG_X86)
244 static void tsc_check_state(int state)
245 {
246         switch (boot_cpu_data.x86_vendor) {
247         case X86_VENDOR_AMD:
248         case X86_VENDOR_INTEL:
249                 /*
250                  * AMD Fam10h TSC will tick in all
251                  * C/P/S0/S1 states when this bit is set.
252                  */
253                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
254                         return;
255
256                 /*FALL THROUGH*/
257         default:
258                 /* TSC could halt in idle, so notify users */
259                 if (state > ACPI_STATE_C1)
260                         mark_tsc_unstable("TSC halts in idle");
261         }
262 }
263 #else
264 static void tsc_check_state(int state) { return; }
265 #endif
266
267 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
268 {
269
270         if (!pr)
271                 return -EINVAL;
272
273         if (!pr->pblk)
274                 return -ENODEV;
275
276         /* if info is obtained from pblk/fadt, type equals state */
277         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
278         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
279
280 #ifndef CONFIG_HOTPLUG_CPU
281         /*
282          * Check for P_LVL2_UP flag before entering C2 and above on
283          * an SMP system.
284          */
285         if ((num_online_cpus() > 1) &&
286             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
287                 return -ENODEV;
288 #endif
289
290         /* determine C2 and C3 address from pblk */
291         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
292         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
293
294         /* determine latencies from FADT */
295         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
296         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
297
298         /*
299          * FADT specified C2 latency must be less than or equal to
300          * 100 microseconds.
301          */
302         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
303                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
304                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
305                 /* invalidate C2 */
306                 pr->power.states[ACPI_STATE_C2].address = 0;
307         }
308
309         /*
310          * FADT supplied C3 latency must be less than or equal to
311          * 1000 microseconds.
312          */
313         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
314                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
315                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
316                 /* invalidate C3 */
317                 pr->power.states[ACPI_STATE_C3].address = 0;
318         }
319
320         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
321                           "lvl2[0x%08x] lvl3[0x%08x]\n",
322                           pr->power.states[ACPI_STATE_C2].address,
323                           pr->power.states[ACPI_STATE_C3].address));
324
325         return 0;
326 }
327
328 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
329 {
330         if (!pr->power.states[ACPI_STATE_C1].valid) {
331                 /* set the first C-State to C1 */
332                 /* all processors need to support C1 */
333                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
334                 pr->power.states[ACPI_STATE_C1].valid = 1;
335                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
336         }
337         /* the C0 state only exists as a filler in our array */
338         pr->power.states[ACPI_STATE_C0].valid = 1;
339         return 0;
340 }
341
342 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
343 {
344         acpi_status status = 0;
345         u64 count;
346         int current_count;
347         int i;
348         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
349         union acpi_object *cst;
350
351
352         if (nocst)
353                 return -ENODEV;
354
355         current_count = 0;
356
357         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
358         if (ACPI_FAILURE(status)) {
359                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
360                 return -ENODEV;
361         }
362
363         cst = buffer.pointer;
364
365         /* There must be at least 2 elements */
366         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
367                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
368                 status = -EFAULT;
369                 goto end;
370         }
371
372         count = cst->package.elements[0].integer.value;
373
374         /* Validate number of power states. */
375         if (count < 1 || count != cst->package.count - 1) {
376                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
377                 status = -EFAULT;
378                 goto end;
379         }
380
381         /* Tell driver that at least _CST is supported. */
382         pr->flags.has_cst = 1;
383
384         for (i = 1; i <= count; i++) {
385                 union acpi_object *element;
386                 union acpi_object *obj;
387                 struct acpi_power_register *reg;
388                 struct acpi_processor_cx cx;
389
390                 memset(&cx, 0, sizeof(cx));
391
392                 element = &(cst->package.elements[i]);
393                 if (element->type != ACPI_TYPE_PACKAGE)
394                         continue;
395
396                 if (element->package.count != 4)
397                         continue;
398
399                 obj = &(element->package.elements[0]);
400
401                 if (obj->type != ACPI_TYPE_BUFFER)
402                         continue;
403
404                 reg = (struct acpi_power_register *)obj->buffer.pointer;
405
406                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
407                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
408                         continue;
409
410                 /* There should be an easy way to extract an integer... */
411                 obj = &(element->package.elements[1]);
412                 if (obj->type != ACPI_TYPE_INTEGER)
413                         continue;
414
415                 cx.type = obj->integer.value;
416                 /*
417                  * Some buggy BIOSes won't list C1 in _CST -
418                  * Let acpi_processor_get_power_info_default() handle them later
419                  */
420                 if (i == 1 && cx.type != ACPI_STATE_C1)
421                         current_count++;
422
423                 cx.address = reg->address;
424                 cx.index = current_count + 1;
425
426                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
427                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
428                         if (acpi_processor_ffh_cstate_probe
429                                         (pr->id, &cx, reg) == 0) {
430                                 cx.entry_method = ACPI_CSTATE_FFH;
431                         } else if (cx.type == ACPI_STATE_C1) {
432                                 /*
433                                  * C1 is a special case where FIXED_HARDWARE
434                                  * can be handled in non-MWAIT way as well.
435                                  * In that case, save this _CST entry info.
436                                  * Otherwise, ignore this info and continue.
437                                  */
438                                 cx.entry_method = ACPI_CSTATE_HALT;
439                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
440                         } else {
441                                 continue;
442                         }
443                         if (cx.type == ACPI_STATE_C1 &&
444                             (boot_option_idle_override == IDLE_NOMWAIT)) {
445                                 /*
446                                  * In most cases the C1 space_id obtained from
447                                  * _CST object is FIXED_HARDWARE access mode.
448                                  * But when the option of idle=halt is added,
449                                  * the entry_method type should be changed from
450                                  * CSTATE_FFH to CSTATE_HALT.
451                                  * When the option of idle=nomwait is added,
452                                  * the C1 entry_method type should be
453                                  * CSTATE_HALT.
454                                  */
455                                 cx.entry_method = ACPI_CSTATE_HALT;
456                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
457                         }
458                 } else {
459                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
460                                  cx.address);
461                 }
462
463                 if (cx.type == ACPI_STATE_C1) {
464                         cx.valid = 1;
465                 }
466
467                 obj = &(element->package.elements[2]);
468                 if (obj->type != ACPI_TYPE_INTEGER)
469                         continue;
470
471                 cx.latency = obj->integer.value;
472
473                 obj = &(element->package.elements[3]);
474                 if (obj->type != ACPI_TYPE_INTEGER)
475                         continue;
476
477                 current_count++;
478                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
479
480                 /*
481                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
482                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
483                  */
484                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
485                         printk(KERN_WARNING
486                                "Limiting number of power states to max (%d)\n",
487                                ACPI_PROCESSOR_MAX_POWER);
488                         printk(KERN_WARNING
489                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
490                         break;
491                 }
492         }
493
494         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
495                           current_count));
496
497         /* Validate number of power states discovered */
498         if (current_count < 2)
499                 status = -EFAULT;
500
501       end:
502         kfree(buffer.pointer);
503
504         return status;
505 }
506
507 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
508                                            struct acpi_processor_cx *cx)
509 {
510         static int bm_check_flag = -1;
511         static int bm_control_flag = -1;
512
513
514         if (!cx->address)
515                 return;
516
517         /*
518          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
519          * DMA transfers are used by any ISA device to avoid livelock.
520          * Note that we could disable Type-F DMA (as recommended by
521          * the erratum), but this is known to disrupt certain ISA
522          * devices thus we take the conservative approach.
523          */
524         else if (errata.piix4.fdma) {
525                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
526                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
527                 return;
528         }
529
530         /* All the logic here assumes flags.bm_check is same across all CPUs */
531         if (bm_check_flag == -1) {
532                 /* Determine whether bm_check is needed based on CPU  */
533                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
534                 bm_check_flag = pr->flags.bm_check;
535                 bm_control_flag = pr->flags.bm_control;
536         } else {
537                 pr->flags.bm_check = bm_check_flag;
538                 pr->flags.bm_control = bm_control_flag;
539         }
540
541         if (pr->flags.bm_check) {
542                 if (!pr->flags.bm_control) {
543                         if (pr->flags.has_cst != 1) {
544                                 /* bus mastering control is necessary */
545                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
546                                         "C3 support requires BM control\n"));
547                                 return;
548                         } else {
549                                 /* Here we enter C3 without bus mastering */
550                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
551                                         "C3 support without BM control\n"));
552                         }
553                 }
554         } else {
555                 /*
556                  * WBINVD should be set in fadt, for C3 state to be
557                  * supported on when bm_check is not required.
558                  */
559                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
560                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
561                                           "Cache invalidation should work properly"
562                                           " for C3 to be enabled on SMP systems\n"));
563                         return;
564                 }
565         }
566
567         /*
568          * Otherwise we've met all of our C3 requirements.
569          * Normalize the C3 latency to expidite policy.  Enable
570          * checking of bus mastering status (bm_check) so we can
571          * use this in our C3 policy
572          */
573         cx->valid = 1;
574
575         /*
576          * On older chipsets, BM_RLD needs to be set
577          * in order for Bus Master activity to wake the
578          * system from C3.  Newer chipsets handle DMA
579          * during C3 automatically and BM_RLD is a NOP.
580          * In either case, the proper way to
581          * handle BM_RLD is to set it and leave it set.
582          */
583         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
584
585         return;
586 }
587
588 static int acpi_processor_power_verify(struct acpi_processor *pr)
589 {
590         unsigned int i;
591         unsigned int working = 0;
592
593         pr->power.timer_broadcast_on_state = INT_MAX;
594
595         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
596                 struct acpi_processor_cx *cx = &pr->power.states[i];
597
598                 switch (cx->type) {
599                 case ACPI_STATE_C1:
600                         cx->valid = 1;
601                         break;
602
603                 case ACPI_STATE_C2:
604                         if (!cx->address)
605                                 break;
606                         cx->valid = 1; 
607                         break;
608
609                 case ACPI_STATE_C3:
610                         acpi_processor_power_verify_c3(pr, cx);
611                         break;
612                 }
613                 if (!cx->valid)
614                         continue;
615
616                 lapic_timer_check_state(i, pr, cx);
617                 tsc_check_state(cx->type);
618                 working++;
619         }
620
621         lapic_timer_propagate_broadcast(pr);
622
623         return (working);
624 }
625
626 static int acpi_processor_get_power_info(struct acpi_processor *pr)
627 {
628         unsigned int i;
629         int result;
630
631
632         /* NOTE: the idle thread may not be running while calling
633          * this function */
634
635         /* Zero initialize all the C-states info. */
636         memset(pr->power.states, 0, sizeof(pr->power.states));
637
638         result = acpi_processor_get_power_info_cst(pr);
639         if (result == -ENODEV)
640                 result = acpi_processor_get_power_info_fadt(pr);
641
642         if (result)
643                 return result;
644
645         acpi_processor_get_power_info_default(pr);
646
647         pr->power.count = acpi_processor_power_verify(pr);
648
649         /*
650          * if one state of type C2 or C3 is available, mark this
651          * CPU as being "idle manageable"
652          */
653         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
654                 if (pr->power.states[i].valid) {
655                         pr->power.count = i;
656                         if (pr->power.states[i].type >= ACPI_STATE_C2)
657                                 pr->flags.power = 1;
658                 }
659         }
660
661         return 0;
662 }
663
664 /**
665  * acpi_idle_bm_check - checks if bus master activity was detected
666  */
667 static int acpi_idle_bm_check(void)
668 {
669         u32 bm_status = 0;
670
671         if (bm_check_disable)
672                 return 0;
673
674         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
675         if (bm_status)
676                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
677         /*
678          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
679          * the true state of bus mastering activity; forcing us to
680          * manually check the BMIDEA bit of each IDE channel.
681          */
682         else if (errata.piix4.bmisx) {
683                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
684                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
685                         bm_status = 1;
686         }
687         return bm_status;
688 }
689
690 /**
691  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
692  * @cx: cstate data
693  *
694  * Caller disables interrupt before call and enables interrupt after return.
695  */
696 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
697 {
698         /* Don't trace irqs off for idle */
699         stop_critical_timings();
700         if (cx->entry_method == ACPI_CSTATE_FFH) {
701                 /* Call into architectural FFH based C-state */
702                 acpi_processor_ffh_cstate_enter(cx);
703         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
704                 acpi_safe_halt();
705         } else {
706                 /* IO port based C-state */
707                 inb(cx->address);
708                 /* Dummy wait op - must do something useless after P_LVL2 read
709                    because chipsets cannot guarantee that STPCLK# signal
710                    gets asserted in time to freeze execution properly. */
711                 inl(acpi_gbl_FADT.xpm_timer_block.address);
712         }
713         start_critical_timings();
714 }
715
716 /**
717  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
718  * @dev: the target CPU
719  * @drv: cpuidle driver containing cpuidle state info
720  * @index: index of target state
721  *
722  * This is equivalent to the HALT instruction.
723  */
724 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
725                 struct cpuidle_driver *drv, int index)
726 {
727         struct acpi_processor *pr;
728         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
729
730         pr = __this_cpu_read(processors);
731
732         if (unlikely(!pr))
733                 return -EINVAL;
734
735         if (cx->entry_method == ACPI_CSTATE_FFH) {
736                 if (current_set_polling_and_test())
737                         return -EINVAL;
738         }
739
740         lapic_timer_state_broadcast(pr, cx, 1);
741         acpi_idle_do_entry(cx);
742
743         lapic_timer_state_broadcast(pr, cx, 0);
744
745         return index;
746 }
747
748
749 /**
750  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
751  * @dev: the target CPU
752  * @index: the index of suggested state
753  */
754 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
755 {
756         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
757
758         ACPI_FLUSH_CPU_CACHE();
759
760         while (1) {
761
762                 if (cx->entry_method == ACPI_CSTATE_HALT)
763                         safe_halt();
764                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
765                         inb(cx->address);
766                         /* See comment in acpi_idle_do_entry() */
767                         inl(acpi_gbl_FADT.xpm_timer_block.address);
768                 } else
769                         return -ENODEV;
770         }
771
772         /* Never reached */
773         return 0;
774 }
775
776 /**
777  * acpi_idle_enter_simple - enters an ACPI state without BM handling
778  * @dev: the target CPU
779  * @drv: cpuidle driver with cpuidle state information
780  * @index: the index of suggested state
781  */
782 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
783                 struct cpuidle_driver *drv, int index)
784 {
785         struct acpi_processor *pr;
786         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
787
788         pr = __this_cpu_read(processors);
789
790         if (unlikely(!pr))
791                 return -EINVAL;
792
793         if (cx->entry_method == ACPI_CSTATE_FFH) {
794                 if (current_set_polling_and_test())
795                         return -EINVAL;
796         }
797
798         /*
799          * Must be done before busmaster disable as we might need to
800          * access HPET !
801          */
802         lapic_timer_state_broadcast(pr, cx, 1);
803
804         if (cx->type == ACPI_STATE_C3)
805                 ACPI_FLUSH_CPU_CACHE();
806
807         /* Tell the scheduler that we are going deep-idle: */
808         sched_clock_idle_sleep_event();
809         acpi_idle_do_entry(cx);
810
811         sched_clock_idle_wakeup_event(0);
812
813         lapic_timer_state_broadcast(pr, cx, 0);
814         return index;
815 }
816
817 static int c3_cpu_count;
818 static DEFINE_RAW_SPINLOCK(c3_lock);
819
820 /**
821  * acpi_idle_enter_bm - enters C3 with proper BM handling
822  * @dev: the target CPU
823  * @drv: cpuidle driver containing state data
824  * @index: the index of suggested state
825  *
826  * If BM is detected, the deepest non-C3 idle state is entered instead.
827  */
828 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
829                 struct cpuidle_driver *drv, int index)
830 {
831         struct acpi_processor *pr;
832         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
833
834         pr = __this_cpu_read(processors);
835
836         if (unlikely(!pr))
837                 return -EINVAL;
838
839         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
840                 if (drv->safe_state_index >= 0) {
841                         return drv->states[drv->safe_state_index].enter(dev,
842                                                 drv, drv->safe_state_index);
843                 } else {
844                         acpi_safe_halt();
845                         return -EBUSY;
846                 }
847         }
848
849         if (cx->entry_method == ACPI_CSTATE_FFH) {
850                 if (current_set_polling_and_test())
851                         return -EINVAL;
852         }
853
854         acpi_unlazy_tlb(smp_processor_id());
855
856         /* Tell the scheduler that we are going deep-idle: */
857         sched_clock_idle_sleep_event();
858         /*
859          * Must be done before busmaster disable as we might need to
860          * access HPET !
861          */
862         lapic_timer_state_broadcast(pr, cx, 1);
863
864         /*
865          * disable bus master
866          * bm_check implies we need ARB_DIS
867          * !bm_check implies we need cache flush
868          * bm_control implies whether we can do ARB_DIS
869          *
870          * That leaves a case where bm_check is set and bm_control is
871          * not set. In that case we cannot do much, we enter C3
872          * without doing anything.
873          */
874         if (pr->flags.bm_check && pr->flags.bm_control) {
875                 raw_spin_lock(&c3_lock);
876                 c3_cpu_count++;
877                 /* Disable bus master arbitration when all CPUs are in C3 */
878                 if (c3_cpu_count == num_online_cpus())
879                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
880                 raw_spin_unlock(&c3_lock);
881         } else if (!pr->flags.bm_check) {
882                 ACPI_FLUSH_CPU_CACHE();
883         }
884
885         acpi_idle_do_entry(cx);
886
887         /* Re-enable bus master arbitration */
888         if (pr->flags.bm_check && pr->flags.bm_control) {
889                 raw_spin_lock(&c3_lock);
890                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
891                 c3_cpu_count--;
892                 raw_spin_unlock(&c3_lock);
893         }
894
895         sched_clock_idle_wakeup_event(0);
896
897         lapic_timer_state_broadcast(pr, cx, 0);
898         return index;
899 }
900
901 struct cpuidle_driver acpi_idle_driver = {
902         .name =         "acpi_idle",
903         .owner =        THIS_MODULE,
904 };
905
906 /**
907  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
908  * device i.e. per-cpu data
909  *
910  * @pr: the ACPI processor
911  * @dev : the cpuidle device
912  */
913 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
914                                            struct cpuidle_device *dev)
915 {
916         int i, count = CPUIDLE_DRIVER_STATE_START;
917         struct acpi_processor_cx *cx;
918
919         if (!pr->flags.power_setup_done)
920                 return -EINVAL;
921
922         if (pr->flags.power == 0) {
923                 return -EINVAL;
924         }
925
926         if (!dev)
927                 return -EINVAL;
928
929         dev->cpu = pr->id;
930
931         if (max_cstate == 0)
932                 max_cstate = 1;
933
934         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
935                 cx = &pr->power.states[i];
936
937                 if (!cx->valid)
938                         continue;
939
940 #ifdef CONFIG_HOTPLUG_CPU
941                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
942                     !pr->flags.has_cst &&
943                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
944                         continue;
945 #endif
946                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
947
948                 count++;
949                 if (count == CPUIDLE_STATE_MAX)
950                         break;
951         }
952
953         dev->state_count = count;
954
955         if (!count)
956                 return -EINVAL;
957
958         return 0;
959 }
960
961 /**
962  * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
963  * global state data i.e. idle routines
964  *
965  * @pr: the ACPI processor
966  */
967 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
968 {
969         int i, count = CPUIDLE_DRIVER_STATE_START;
970         struct acpi_processor_cx *cx;
971         struct cpuidle_state *state;
972         struct cpuidle_driver *drv = &acpi_idle_driver;
973
974         if (!pr->flags.power_setup_done)
975                 return -EINVAL;
976
977         if (pr->flags.power == 0)
978                 return -EINVAL;
979
980         drv->safe_state_index = -1;
981         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
982                 drv->states[i].name[0] = '\0';
983                 drv->states[i].desc[0] = '\0';
984         }
985
986         if (max_cstate == 0)
987                 max_cstate = 1;
988
989         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
990                 cx = &pr->power.states[i];
991
992                 if (!cx->valid)
993                         continue;
994
995 #ifdef CONFIG_HOTPLUG_CPU
996                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
997                     !pr->flags.has_cst &&
998                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
999                         continue;
1000 #endif
1001
1002                 state = &drv->states[count];
1003                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1004                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1005                 state->exit_latency = cx->latency;
1006                 state->target_residency = cx->latency * latency_factor;
1007
1008                 state->flags = 0;
1009                 switch (cx->type) {
1010                         case ACPI_STATE_C1:
1011                         if (cx->entry_method == ACPI_CSTATE_FFH)
1012                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1013
1014                         state->enter = acpi_idle_enter_c1;
1015                         state->enter_dead = acpi_idle_play_dead;
1016                         drv->safe_state_index = count;
1017                         break;
1018
1019                         case ACPI_STATE_C2:
1020                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1021                         state->enter = acpi_idle_enter_simple;
1022                         state->enter_dead = acpi_idle_play_dead;
1023                         drv->safe_state_index = count;
1024                         break;
1025
1026                         case ACPI_STATE_C3:
1027                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1028                         state->enter = pr->flags.bm_check ?
1029                                         acpi_idle_enter_bm :
1030                                         acpi_idle_enter_simple;
1031                         break;
1032                 }
1033
1034                 count++;
1035                 if (count == CPUIDLE_STATE_MAX)
1036                         break;
1037         }
1038
1039         drv->state_count = count;
1040
1041         if (!count)
1042                 return -EINVAL;
1043
1044         return 0;
1045 }
1046
1047 int acpi_processor_hotplug(struct acpi_processor *pr)
1048 {
1049         int ret = 0;
1050         struct cpuidle_device *dev;
1051
1052         if (disabled_by_idle_boot_param())
1053                 return 0;
1054
1055         if (!pr)
1056                 return -EINVAL;
1057
1058         if (nocst) {
1059                 return -ENODEV;
1060         }
1061
1062         if (!pr->flags.power_setup_done)
1063                 return -ENODEV;
1064
1065         dev = per_cpu(acpi_cpuidle_device, pr->id);
1066         cpuidle_pause_and_lock();
1067         cpuidle_disable_device(dev);
1068         acpi_processor_get_power_info(pr);
1069         if (pr->flags.power) {
1070                 acpi_processor_setup_cpuidle_cx(pr, dev);
1071                 ret = cpuidle_enable_device(dev);
1072         }
1073         cpuidle_resume_and_unlock();
1074
1075         return ret;
1076 }
1077
1078 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1079 {
1080         int cpu;
1081         struct acpi_processor *_pr;
1082         struct cpuidle_device *dev;
1083
1084         if (disabled_by_idle_boot_param())
1085                 return 0;
1086
1087         if (!pr)
1088                 return -EINVAL;
1089
1090         if (nocst)
1091                 return -ENODEV;
1092
1093         if (!pr->flags.power_setup_done)
1094                 return -ENODEV;
1095
1096         /*
1097          * FIXME:  Design the ACPI notification to make it once per
1098          * system instead of once per-cpu.  This condition is a hack
1099          * to make the code that updates C-States be called once.
1100          */
1101
1102         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1103
1104                 cpuidle_pause_and_lock();
1105                 /* Protect against cpu-hotplug */
1106                 get_online_cpus();
1107
1108                 /* Disable all cpuidle devices */
1109                 for_each_online_cpu(cpu) {
1110                         _pr = per_cpu(processors, cpu);
1111                         if (!_pr || !_pr->flags.power_setup_done)
1112                                 continue;
1113                         dev = per_cpu(acpi_cpuidle_device, cpu);
1114                         cpuidle_disable_device(dev);
1115                 }
1116
1117                 /* Populate Updated C-state information */
1118                 acpi_processor_get_power_info(pr);
1119                 acpi_processor_setup_cpuidle_states(pr);
1120
1121                 /* Enable all cpuidle devices */
1122                 for_each_online_cpu(cpu) {
1123                         _pr = per_cpu(processors, cpu);
1124                         if (!_pr || !_pr->flags.power_setup_done)
1125                                 continue;
1126                         acpi_processor_get_power_info(_pr);
1127                         if (_pr->flags.power) {
1128                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1129                                 acpi_processor_setup_cpuidle_cx(_pr, dev);
1130                                 cpuidle_enable_device(dev);
1131                         }
1132                 }
1133                 put_online_cpus();
1134                 cpuidle_resume_and_unlock();
1135         }
1136
1137         return 0;
1138 }
1139
1140 static int acpi_processor_registered;
1141
1142 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr)
1143 {
1144         acpi_status status = 0;
1145         int retval;
1146         struct cpuidle_device *dev;
1147         static int first_run;
1148
1149         if (disabled_by_idle_boot_param())
1150                 return 0;
1151
1152         if (!first_run) {
1153                 dmi_check_system(processor_power_dmi_table);
1154                 max_cstate = acpi_processor_cstate_check(max_cstate);
1155                 if (max_cstate < ACPI_C_STATES_MAX)
1156                         printk(KERN_NOTICE
1157                                "ACPI: processor limited to max C-state %d\n",
1158                                max_cstate);
1159                 first_run++;
1160         }
1161
1162         if (!pr)
1163                 return -EINVAL;
1164
1165         if (acpi_gbl_FADT.cst_control && !nocst) {
1166                 status =
1167                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1168                 if (ACPI_FAILURE(status)) {
1169                         ACPI_EXCEPTION((AE_INFO, status,
1170                                         "Notifying BIOS of _CST ability failed"));
1171                 }
1172         }
1173
1174         acpi_processor_get_power_info(pr);
1175         pr->flags.power_setup_done = 1;
1176
1177         /*
1178          * Install the idle handler if processor power management is supported.
1179          * Note that we use previously set idle handler will be used on
1180          * platforms that only support C1.
1181          */
1182         if (pr->flags.power) {
1183                 /* Register acpi_idle_driver if not already registered */
1184                 if (!acpi_processor_registered) {
1185                         acpi_processor_setup_cpuidle_states(pr);
1186                         retval = cpuidle_register_driver(&acpi_idle_driver);
1187                         if (retval)
1188                                 return retval;
1189                         printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1190                                         acpi_idle_driver.name);
1191                 }
1192
1193                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1194                 if (!dev)
1195                         return -ENOMEM;
1196                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1197
1198                 acpi_processor_setup_cpuidle_cx(pr, dev);
1199
1200                 /* Register per-cpu cpuidle_device. Cpuidle driver
1201                  * must already be registered before registering device
1202                  */
1203                 retval = cpuidle_register_device(dev);
1204                 if (retval) {
1205                         if (acpi_processor_registered == 0)
1206                                 cpuidle_unregister_driver(&acpi_idle_driver);
1207                         return retval;
1208                 }
1209                 acpi_processor_registered++;
1210         }
1211         return 0;
1212 }
1213
1214 int acpi_processor_power_exit(struct acpi_processor *pr)
1215 {
1216         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1217
1218         if (disabled_by_idle_boot_param())
1219                 return 0;
1220
1221         if (pr->flags.power) {
1222                 cpuidle_unregister_device(dev);
1223                 acpi_processor_registered--;
1224                 if (acpi_processor_registered == 0)
1225                         cpuidle_unregister_driver(&acpi_idle_driver);
1226         }
1227
1228         pr->flags.power_setup_done = 0;
1229         return 0;
1230 }