thinkpad-acpi: support the second fan on the X61
[linux-2.6.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/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/moduleparam.h>
40 #include <linux/sched.h>        /* need_resched() */
41 #include <linux/pm_qos_params.h>
42 #include <linux/clockchips.h>
43 #include <linux/cpuidle.h>
44 #include <linux/irqflags.h>
45
46 /*
47  * Include the apic definitions for x86 to have the APIC timer related defines
48  * available also for UP (on SMP it gets magically included via linux/smp.h).
49  * asm/acpi.h is not an option, as it would require more include magic. Also
50  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
51  */
52 #ifdef CONFIG_X86
53 #include <asm/apic.h>
54 #endif
55
56 #include <asm/io.h>
57 #include <asm/uaccess.h>
58
59 #include <acpi/acpi_bus.h>
60 #include <acpi/processor.h>
61 #include <asm/processor.h>
62
63 #define ACPI_PROCESSOR_CLASS            "processor"
64 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
65 ACPI_MODULE_NAME("processor_idle");
66 #define ACPI_PROCESSOR_FILE_POWER       "power"
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
77 static unsigned int latency_factor __read_mostly = 2;
78 module_param(latency_factor, uint, 0644);
79
80 static s64 us_to_pm_timer_ticks(s64 t)
81 {
82         return div64_u64(t * PM_TIMER_FREQUENCY, 1000000);
83 }
84 /*
85  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
86  * For now disable this. Probably a bug somewhere else.
87  *
88  * To skip this limit, boot/load with a large max_cstate limit.
89  */
90 static int set_max_cstate(const struct dmi_system_id *id)
91 {
92         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
93                 return 0;
94
95         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
96                " Override with \"processor.max_cstate=%d\"\n", id->ident,
97                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
98
99         max_cstate = (long)id->driver_data;
100
101         return 0;
102 }
103
104 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
105    callers to only run once -AK */
106 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
107         { set_max_cstate, "Clevo 5600D", {
108           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
109           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
110          (void *)2},
111         {},
112 };
113
114
115 /*
116  * Callers should disable interrupts before the call and enable
117  * interrupts after return.
118  */
119 static void acpi_safe_halt(void)
120 {
121         current_thread_info()->status &= ~TS_POLLING;
122         /*
123          * TS_POLLING-cleared state must be visible before we
124          * test NEED_RESCHED:
125          */
126         smp_mb();
127         if (!need_resched()) {
128                 safe_halt();
129                 local_irq_disable();
130         }
131         current_thread_info()->status |= TS_POLLING;
132 }
133
134 #ifdef ARCH_APICTIMER_STOPS_ON_C3
135
136 /*
137  * Some BIOS implementations switch to C3 in the published C2 state.
138  * This seems to be a common problem on AMD boxen, but other vendors
139  * are affected too. We pick the most conservative approach: we assume
140  * that the local APIC stops in both C2 and C3.
141  */
142 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
143                                    struct acpi_processor_cx *cx)
144 {
145         struct acpi_processor_power *pwr = &pr->power;
146         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
147
148         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
149                 return;
150
151         if (boot_cpu_has(X86_FEATURE_AMDC1E))
152                 type = ACPI_STATE_C1;
153
154         /*
155          * Check, if one of the previous states already marked the lapic
156          * unstable
157          */
158         if (pwr->timer_broadcast_on_state < state)
159                 return;
160
161         if (cx->type >= type)
162                 pr->power.timer_broadcast_on_state = state;
163 }
164
165 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
166 {
167         unsigned long reason;
168
169         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
170                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
171
172         clockevents_notify(reason, &pr->id);
173 }
174
175 /* Power(C) State timer broadcast control */
176 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
177                                        struct acpi_processor_cx *cx,
178                                        int broadcast)
179 {
180         int state = cx - pr->power.states;
181
182         if (state >= pr->power.timer_broadcast_on_state) {
183                 unsigned long reason;
184
185                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
186                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
187                 clockevents_notify(reason, &pr->id);
188         }
189 }
190
191 #else
192
193 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
194                                    struct acpi_processor_cx *cstate) { }
195 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
196 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
197                                        struct acpi_processor_cx *cx,
198                                        int broadcast)
199 {
200 }
201
202 #endif
203
204 /*
205  * Suspend / resume control
206  */
207 static int acpi_idle_suspend;
208 static u32 saved_bm_rld;
209
210 static void acpi_idle_bm_rld_save(void)
211 {
212         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
213 }
214 static void acpi_idle_bm_rld_restore(void)
215 {
216         u32 resumed_bm_rld;
217
218         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
219
220         if (resumed_bm_rld != saved_bm_rld)
221                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
222 }
223
224 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
225 {
226         if (acpi_idle_suspend == 1)
227                 return 0;
228
229         acpi_idle_bm_rld_save();
230         acpi_idle_suspend = 1;
231         return 0;
232 }
233
234 int acpi_processor_resume(struct acpi_device * device)
235 {
236         if (acpi_idle_suspend == 0)
237                 return 0;
238
239         acpi_idle_bm_rld_restore();
240         acpi_idle_suspend = 0;
241         return 0;
242 }
243
244 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
245 static void tsc_check_state(int state)
246 {
247         switch (boot_cpu_data.x86_vendor) {
248         case X86_VENDOR_AMD:
249         case X86_VENDOR_INTEL:
250                 /*
251                  * AMD Fam10h TSC will tick in all
252                  * C/P/S0/S1 states when this bit is set.
253                  */
254                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
255                         return;
256
257                 /*FALL THROUGH*/
258         default:
259                 /* TSC could halt in idle, so notify users */
260                 if (state > ACPI_STATE_C1)
261                         mark_tsc_unstable("TSC halts in idle");
262         }
263 }
264 #else
265 static void tsc_check_state(int state) { return; }
266 #endif
267
268 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
269 {
270
271         if (!pr)
272                 return -EINVAL;
273
274         if (!pr->pblk)
275                 return -ENODEV;
276
277         /* if info is obtained from pblk/fadt, type equals state */
278         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
279         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
280
281 #ifndef CONFIG_HOTPLUG_CPU
282         /*
283          * Check for P_LVL2_UP flag before entering C2 and above on
284          * an SMP system.
285          */
286         if ((num_online_cpus() > 1) &&
287             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
288                 return -ENODEV;
289 #endif
290
291         /* determine C2 and C3 address from pblk */
292         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
293         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
294
295         /* determine latencies from FADT */
296         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
297         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
298
299         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
300                           "lvl2[0x%08x] lvl3[0x%08x]\n",
301                           pr->power.states[ACPI_STATE_C2].address,
302                           pr->power.states[ACPI_STATE_C3].address));
303
304         return 0;
305 }
306
307 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
308 {
309         if (!pr->power.states[ACPI_STATE_C1].valid) {
310                 /* set the first C-State to C1 */
311                 /* all processors need to support C1 */
312                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
313                 pr->power.states[ACPI_STATE_C1].valid = 1;
314                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
315         }
316         /* the C0 state only exists as a filler in our array */
317         pr->power.states[ACPI_STATE_C0].valid = 1;
318         return 0;
319 }
320
321 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
322 {
323         acpi_status status = 0;
324         acpi_integer count;
325         int current_count;
326         int i;
327         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
328         union acpi_object *cst;
329
330
331         if (nocst)
332                 return -ENODEV;
333
334         current_count = 0;
335
336         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
337         if (ACPI_FAILURE(status)) {
338                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
339                 return -ENODEV;
340         }
341
342         cst = buffer.pointer;
343
344         /* There must be at least 2 elements */
345         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
346                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
347                 status = -EFAULT;
348                 goto end;
349         }
350
351         count = cst->package.elements[0].integer.value;
352
353         /* Validate number of power states. */
354         if (count < 1 || count != cst->package.count - 1) {
355                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
356                 status = -EFAULT;
357                 goto end;
358         }
359
360         /* Tell driver that at least _CST is supported. */
361         pr->flags.has_cst = 1;
362
363         for (i = 1; i <= count; i++) {
364                 union acpi_object *element;
365                 union acpi_object *obj;
366                 struct acpi_power_register *reg;
367                 struct acpi_processor_cx cx;
368
369                 memset(&cx, 0, sizeof(cx));
370
371                 element = &(cst->package.elements[i]);
372                 if (element->type != ACPI_TYPE_PACKAGE)
373                         continue;
374
375                 if (element->package.count != 4)
376                         continue;
377
378                 obj = &(element->package.elements[0]);
379
380                 if (obj->type != ACPI_TYPE_BUFFER)
381                         continue;
382
383                 reg = (struct acpi_power_register *)obj->buffer.pointer;
384
385                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
386                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
387                         continue;
388
389                 /* There should be an easy way to extract an integer... */
390                 obj = &(element->package.elements[1]);
391                 if (obj->type != ACPI_TYPE_INTEGER)
392                         continue;
393
394                 cx.type = obj->integer.value;
395                 /*
396                  * Some buggy BIOSes won't list C1 in _CST -
397                  * Let acpi_processor_get_power_info_default() handle them later
398                  */
399                 if (i == 1 && cx.type != ACPI_STATE_C1)
400                         current_count++;
401
402                 cx.address = reg->address;
403                 cx.index = current_count + 1;
404
405                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
406                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
407                         if (acpi_processor_ffh_cstate_probe
408                                         (pr->id, &cx, reg) == 0) {
409                                 cx.entry_method = ACPI_CSTATE_FFH;
410                         } else if (cx.type == ACPI_STATE_C1) {
411                                 /*
412                                  * C1 is a special case where FIXED_HARDWARE
413                                  * can be handled in non-MWAIT way as well.
414                                  * In that case, save this _CST entry info.
415                                  * Otherwise, ignore this info and continue.
416                                  */
417                                 cx.entry_method = ACPI_CSTATE_HALT;
418                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
419                         } else {
420                                 continue;
421                         }
422                         if (cx.type == ACPI_STATE_C1 &&
423                                         (idle_halt || idle_nomwait)) {
424                                 /*
425                                  * In most cases the C1 space_id obtained from
426                                  * _CST object is FIXED_HARDWARE access mode.
427                                  * But when the option of idle=halt is added,
428                                  * the entry_method type should be changed from
429                                  * CSTATE_FFH to CSTATE_HALT.
430                                  * When the option of idle=nomwait is added,
431                                  * the C1 entry_method type should be
432                                  * CSTATE_HALT.
433                                  */
434                                 cx.entry_method = ACPI_CSTATE_HALT;
435                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
436                         }
437                 } else {
438                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
439                                  cx.address);
440                 }
441
442                 if (cx.type == ACPI_STATE_C1) {
443                         cx.valid = 1;
444                 }
445
446                 obj = &(element->package.elements[2]);
447                 if (obj->type != ACPI_TYPE_INTEGER)
448                         continue;
449
450                 cx.latency = obj->integer.value;
451
452                 obj = &(element->package.elements[3]);
453                 if (obj->type != ACPI_TYPE_INTEGER)
454                         continue;
455
456                 cx.power = obj->integer.value;
457
458                 current_count++;
459                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
460
461                 /*
462                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
463                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
464                  */
465                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
466                         printk(KERN_WARNING
467                                "Limiting number of power states to max (%d)\n",
468                                ACPI_PROCESSOR_MAX_POWER);
469                         printk(KERN_WARNING
470                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
471                         break;
472                 }
473         }
474
475         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
476                           current_count));
477
478         /* Validate number of power states discovered */
479         if (current_count < 2)
480                 status = -EFAULT;
481
482       end:
483         kfree(buffer.pointer);
484
485         return status;
486 }
487
488 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
489 {
490
491         if (!cx->address)
492                 return;
493
494         /*
495          * C2 latency must be less than or equal to 100
496          * microseconds.
497          */
498         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
499                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
500                                   "latency too large [%d]\n", cx->latency));
501                 return;
502         }
503
504         /*
505          * Otherwise we've met all of our C2 requirements.
506          * Normalize the C2 latency to expidite policy
507          */
508         cx->valid = 1;
509
510         cx->latency_ticks = cx->latency;
511
512         return;
513 }
514
515 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
516                                            struct acpi_processor_cx *cx)
517 {
518         static int bm_check_flag;
519
520
521         if (!cx->address)
522                 return;
523
524         /*
525          * C3 latency must be less than or equal to 1000
526          * microseconds.
527          */
528         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
529                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
530                                   "latency too large [%d]\n", cx->latency));
531                 return;
532         }
533
534         /*
535          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
536          * DMA transfers are used by any ISA device to avoid livelock.
537          * Note that we could disable Type-F DMA (as recommended by
538          * the erratum), but this is known to disrupt certain ISA
539          * devices thus we take the conservative approach.
540          */
541         else if (errata.piix4.fdma) {
542                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
543                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
544                 return;
545         }
546
547         /* All the logic here assumes flags.bm_check is same across all CPUs */
548         if (!bm_check_flag) {
549                 /* Determine whether bm_check is needed based on CPU  */
550                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
551                 bm_check_flag = pr->flags.bm_check;
552         } else {
553                 pr->flags.bm_check = bm_check_flag;
554         }
555
556         if (pr->flags.bm_check) {
557                 if (!pr->flags.bm_control) {
558                         if (pr->flags.has_cst != 1) {
559                                 /* bus mastering control is necessary */
560                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
561                                         "C3 support requires BM control\n"));
562                                 return;
563                         } else {
564                                 /* Here we enter C3 without bus mastering */
565                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
566                                         "C3 support without BM control\n"));
567                         }
568                 }
569         } else {
570                 /*
571                  * WBINVD should be set in fadt, for C3 state to be
572                  * supported on when bm_check is not required.
573                  */
574                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
575                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
576                                           "Cache invalidation should work properly"
577                                           " for C3 to be enabled on SMP systems\n"));
578                         return;
579                 }
580         }
581
582         /*
583          * Otherwise we've met all of our C3 requirements.
584          * Normalize the C3 latency to expidite policy.  Enable
585          * checking of bus mastering status (bm_check) so we can
586          * use this in our C3 policy
587          */
588         cx->valid = 1;
589
590         cx->latency_ticks = cx->latency;
591         /*
592          * On older chipsets, BM_RLD needs to be set
593          * in order for Bus Master activity to wake the
594          * system from C3.  Newer chipsets handle DMA
595          * during C3 automatically and BM_RLD is a NOP.
596          * In either case, the proper way to
597          * handle BM_RLD is to set it and leave it set.
598          */
599         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
600
601         return;
602 }
603
604 static int acpi_processor_power_verify(struct acpi_processor *pr)
605 {
606         unsigned int i;
607         unsigned int working = 0;
608
609         pr->power.timer_broadcast_on_state = INT_MAX;
610
611         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
612                 struct acpi_processor_cx *cx = &pr->power.states[i];
613
614                 switch (cx->type) {
615                 case ACPI_STATE_C1:
616                         cx->valid = 1;
617                         acpi_timer_check_state(i, pr, cx);
618                         break;
619
620                 case ACPI_STATE_C2:
621                         acpi_processor_power_verify_c2(cx);
622                         if (cx->valid)
623                                 acpi_timer_check_state(i, pr, cx);
624                         break;
625
626                 case ACPI_STATE_C3:
627                         acpi_processor_power_verify_c3(pr, cx);
628                         if (cx->valid)
629                                 acpi_timer_check_state(i, pr, cx);
630                         break;
631                 }
632                 if (cx->valid)
633                         tsc_check_state(cx->type);
634
635                 if (cx->valid)
636                         working++;
637         }
638
639         acpi_propagate_timer_broadcast(pr);
640
641         return (working);
642 }
643
644 static int acpi_processor_get_power_info(struct acpi_processor *pr)
645 {
646         unsigned int i;
647         int result;
648
649
650         /* NOTE: the idle thread may not be running while calling
651          * this function */
652
653         /* Zero initialize all the C-states info. */
654         memset(pr->power.states, 0, sizeof(pr->power.states));
655
656         result = acpi_processor_get_power_info_cst(pr);
657         if (result == -ENODEV)
658                 result = acpi_processor_get_power_info_fadt(pr);
659
660         if (result)
661                 return result;
662
663         acpi_processor_get_power_info_default(pr);
664
665         pr->power.count = acpi_processor_power_verify(pr);
666
667         /*
668          * if one state of type C2 or C3 is available, mark this
669          * CPU as being "idle manageable"
670          */
671         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
672                 if (pr->power.states[i].valid) {
673                         pr->power.count = i;
674                         if (pr->power.states[i].type >= ACPI_STATE_C2)
675                                 pr->flags.power = 1;
676                 }
677         }
678
679         return 0;
680 }
681
682 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
683 {
684         struct acpi_processor *pr = seq->private;
685         unsigned int i;
686
687
688         if (!pr)
689                 goto end;
690
691         seq_printf(seq, "active state:            C%zd\n"
692                    "max_cstate:              C%d\n"
693                    "maximum allowed latency: %d usec\n",
694                    pr->power.state ? pr->power.state - pr->power.states : 0,
695                    max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
696
697         seq_puts(seq, "states:\n");
698
699         for (i = 1; i <= pr->power.count; i++) {
700                 seq_printf(seq, "   %cC%d:                  ",
701                            (&pr->power.states[i] ==
702                             pr->power.state ? '*' : ' '), i);
703
704                 if (!pr->power.states[i].valid) {
705                         seq_puts(seq, "<not supported>\n");
706                         continue;
707                 }
708
709                 switch (pr->power.states[i].type) {
710                 case ACPI_STATE_C1:
711                         seq_printf(seq, "type[C1] ");
712                         break;
713                 case ACPI_STATE_C2:
714                         seq_printf(seq, "type[C2] ");
715                         break;
716                 case ACPI_STATE_C3:
717                         seq_printf(seq, "type[C3] ");
718                         break;
719                 default:
720                         seq_printf(seq, "type[--] ");
721                         break;
722                 }
723
724                 if (pr->power.states[i].promotion.state)
725                         seq_printf(seq, "promotion[C%zd] ",
726                                    (pr->power.states[i].promotion.state -
727                                     pr->power.states));
728                 else
729                         seq_puts(seq, "promotion[--] ");
730
731                 if (pr->power.states[i].demotion.state)
732                         seq_printf(seq, "demotion[C%zd] ",
733                                    (pr->power.states[i].demotion.state -
734                                     pr->power.states));
735                 else
736                         seq_puts(seq, "demotion[--] ");
737
738                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
739                            pr->power.states[i].latency,
740                            pr->power.states[i].usage,
741                            (unsigned long long)pr->power.states[i].time);
742         }
743
744       end:
745         return 0;
746 }
747
748 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
749 {
750         return single_open(file, acpi_processor_power_seq_show,
751                            PDE(inode)->data);
752 }
753
754 static const struct file_operations acpi_processor_power_fops = {
755         .owner = THIS_MODULE,
756         .open = acpi_processor_power_open_fs,
757         .read = seq_read,
758         .llseek = seq_lseek,
759         .release = single_release,
760 };
761
762
763 /**
764  * acpi_idle_bm_check - checks if bus master activity was detected
765  */
766 static int acpi_idle_bm_check(void)
767 {
768         u32 bm_status = 0;
769
770         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
771         if (bm_status)
772                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
773         /*
774          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
775          * the true state of bus mastering activity; forcing us to
776          * manually check the BMIDEA bit of each IDE channel.
777          */
778         else if (errata.piix4.bmisx) {
779                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
780                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
781                         bm_status = 1;
782         }
783         return bm_status;
784 }
785
786 /**
787  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
788  * @cx: cstate data
789  *
790  * Caller disables interrupt before call and enables interrupt after return.
791  */
792 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
793 {
794         /* Don't trace irqs off for idle */
795         stop_critical_timings();
796         if (cx->entry_method == ACPI_CSTATE_FFH) {
797                 /* Call into architectural FFH based C-state */
798                 acpi_processor_ffh_cstate_enter(cx);
799         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
800                 acpi_safe_halt();
801         } else {
802                 int unused;
803                 /* IO port based C-state */
804                 inb(cx->address);
805                 /* Dummy wait op - must do something useless after P_LVL2 read
806                    because chipsets cannot guarantee that STPCLK# signal
807                    gets asserted in time to freeze execution properly. */
808                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
809         }
810         start_critical_timings();
811 }
812
813 /**
814  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
815  * @dev: the target CPU
816  * @state: the state data
817  *
818  * This is equivalent to the HALT instruction.
819  */
820 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
821                               struct cpuidle_state *state)
822 {
823         ktime_t  kt1, kt2;
824         s64 idle_time;
825         struct acpi_processor *pr;
826         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
827
828         pr = __get_cpu_var(processors);
829
830         if (unlikely(!pr))
831                 return 0;
832
833         local_irq_disable();
834
835         /* Do not access any ACPI IO ports in suspend path */
836         if (acpi_idle_suspend) {
837                 local_irq_enable();
838                 cpu_relax();
839                 return 0;
840         }
841
842         acpi_state_timer_broadcast(pr, cx, 1);
843         kt1 = ktime_get_real();
844         acpi_idle_do_entry(cx);
845         kt2 = ktime_get_real();
846         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
847
848         local_irq_enable();
849         cx->usage++;
850         acpi_state_timer_broadcast(pr, cx, 0);
851
852         return idle_time;
853 }
854
855 /**
856  * acpi_idle_enter_simple - enters an ACPI state without BM handling
857  * @dev: the target CPU
858  * @state: the state data
859  */
860 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
861                                   struct cpuidle_state *state)
862 {
863         struct acpi_processor *pr;
864         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
865         ktime_t  kt1, kt2;
866         s64 idle_time;
867         s64 sleep_ticks = 0;
868
869         pr = __get_cpu_var(processors);
870
871         if (unlikely(!pr))
872                 return 0;
873
874         if (acpi_idle_suspend)
875                 return(acpi_idle_enter_c1(dev, state));
876
877         local_irq_disable();
878         current_thread_info()->status &= ~TS_POLLING;
879         /*
880          * TS_POLLING-cleared state must be visible before we test
881          * NEED_RESCHED:
882          */
883         smp_mb();
884
885         if (unlikely(need_resched())) {
886                 current_thread_info()->status |= TS_POLLING;
887                 local_irq_enable();
888                 return 0;
889         }
890
891         /*
892          * Must be done before busmaster disable as we might need to
893          * access HPET !
894          */
895         acpi_state_timer_broadcast(pr, cx, 1);
896
897         if (cx->type == ACPI_STATE_C3)
898                 ACPI_FLUSH_CPU_CACHE();
899
900         kt1 = ktime_get_real();
901         /* Tell the scheduler that we are going deep-idle: */
902         sched_clock_idle_sleep_event();
903         acpi_idle_do_entry(cx);
904         kt2 = ktime_get_real();
905         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
906
907         sleep_ticks = us_to_pm_timer_ticks(idle_time);
908
909         /* Tell the scheduler how much we idled: */
910         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
911
912         local_irq_enable();
913         current_thread_info()->status |= TS_POLLING;
914
915         cx->usage++;
916
917         acpi_state_timer_broadcast(pr, cx, 0);
918         cx->time += sleep_ticks;
919         return idle_time;
920 }
921
922 static int c3_cpu_count;
923 static DEFINE_SPINLOCK(c3_lock);
924
925 /**
926  * acpi_idle_enter_bm - enters C3 with proper BM handling
927  * @dev: the target CPU
928  * @state: the state data
929  *
930  * If BM is detected, the deepest non-C3 idle state is entered instead.
931  */
932 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
933                               struct cpuidle_state *state)
934 {
935         struct acpi_processor *pr;
936         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
937         ktime_t  kt1, kt2;
938         s64 idle_time;
939         s64 sleep_ticks = 0;
940
941
942         pr = __get_cpu_var(processors);
943
944         if (unlikely(!pr))
945                 return 0;
946
947         if (acpi_idle_suspend)
948                 return(acpi_idle_enter_c1(dev, state));
949
950         if (acpi_idle_bm_check()) {
951                 if (dev->safe_state) {
952                         dev->last_state = dev->safe_state;
953                         return dev->safe_state->enter(dev, dev->safe_state);
954                 } else {
955                         local_irq_disable();
956                         acpi_safe_halt();
957                         local_irq_enable();
958                         return 0;
959                 }
960         }
961
962         local_irq_disable();
963         current_thread_info()->status &= ~TS_POLLING;
964         /*
965          * TS_POLLING-cleared state must be visible before we test
966          * NEED_RESCHED:
967          */
968         smp_mb();
969
970         if (unlikely(need_resched())) {
971                 current_thread_info()->status |= TS_POLLING;
972                 local_irq_enable();
973                 return 0;
974         }
975
976         acpi_unlazy_tlb(smp_processor_id());
977
978         /* Tell the scheduler that we are going deep-idle: */
979         sched_clock_idle_sleep_event();
980         /*
981          * Must be done before busmaster disable as we might need to
982          * access HPET !
983          */
984         acpi_state_timer_broadcast(pr, cx, 1);
985
986         kt1 = ktime_get_real();
987         /*
988          * disable bus master
989          * bm_check implies we need ARB_DIS
990          * !bm_check implies we need cache flush
991          * bm_control implies whether we can do ARB_DIS
992          *
993          * That leaves a case where bm_check is set and bm_control is
994          * not set. In that case we cannot do much, we enter C3
995          * without doing anything.
996          */
997         if (pr->flags.bm_check && pr->flags.bm_control) {
998                 spin_lock(&c3_lock);
999                 c3_cpu_count++;
1000                 /* Disable bus master arbitration when all CPUs are in C3 */
1001                 if (c3_cpu_count == num_online_cpus())
1002                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
1003                 spin_unlock(&c3_lock);
1004         } else if (!pr->flags.bm_check) {
1005                 ACPI_FLUSH_CPU_CACHE();
1006         }
1007
1008         acpi_idle_do_entry(cx);
1009
1010         /* Re-enable bus master arbitration */
1011         if (pr->flags.bm_check && pr->flags.bm_control) {
1012                 spin_lock(&c3_lock);
1013                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
1014                 c3_cpu_count--;
1015                 spin_unlock(&c3_lock);
1016         }
1017         kt2 = ktime_get_real();
1018         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
1019
1020         sleep_ticks = us_to_pm_timer_ticks(idle_time);
1021         /* Tell the scheduler how much we idled: */
1022         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1023
1024         local_irq_enable();
1025         current_thread_info()->status |= TS_POLLING;
1026
1027         cx->usage++;
1028
1029         acpi_state_timer_broadcast(pr, cx, 0);
1030         cx->time += sleep_ticks;
1031         return idle_time;
1032 }
1033
1034 struct cpuidle_driver acpi_idle_driver = {
1035         .name =         "acpi_idle",
1036         .owner =        THIS_MODULE,
1037 };
1038
1039 /**
1040  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1041  * @pr: the ACPI processor
1042  */
1043 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1044 {
1045         int i, count = CPUIDLE_DRIVER_STATE_START;
1046         struct acpi_processor_cx *cx;
1047         struct cpuidle_state *state;
1048         struct cpuidle_device *dev = &pr->power.dev;
1049
1050         if (!pr->flags.power_setup_done)
1051                 return -EINVAL;
1052
1053         if (pr->flags.power == 0) {
1054                 return -EINVAL;
1055         }
1056
1057         dev->cpu = pr->id;
1058         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1059                 dev->states[i].name[0] = '\0';
1060                 dev->states[i].desc[0] = '\0';
1061         }
1062
1063         if (max_cstate == 0)
1064                 max_cstate = 1;
1065
1066         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1067                 cx = &pr->power.states[i];
1068                 state = &dev->states[count];
1069
1070                 if (!cx->valid)
1071                         continue;
1072
1073 #ifdef CONFIG_HOTPLUG_CPU
1074                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1075                     !pr->flags.has_cst &&
1076                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1077                         continue;
1078 #endif
1079                 cpuidle_set_statedata(state, cx);
1080
1081                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1082                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1083                 state->exit_latency = cx->latency;
1084                 state->target_residency = cx->latency * latency_factor;
1085                 state->power_usage = cx->power;
1086
1087                 state->flags = 0;
1088                 switch (cx->type) {
1089                         case ACPI_STATE_C1:
1090                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1091                         if (cx->entry_method == ACPI_CSTATE_FFH)
1092                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1093
1094                         state->enter = acpi_idle_enter_c1;
1095                         dev->safe_state = state;
1096                         break;
1097
1098                         case ACPI_STATE_C2:
1099                         state->flags |= CPUIDLE_FLAG_BALANCED;
1100                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1101                         state->enter = acpi_idle_enter_simple;
1102                         dev->safe_state = state;
1103                         break;
1104
1105                         case ACPI_STATE_C3:
1106                         state->flags |= CPUIDLE_FLAG_DEEP;
1107                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1108                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1109                         state->enter = pr->flags.bm_check ?
1110                                         acpi_idle_enter_bm :
1111                                         acpi_idle_enter_simple;
1112                         break;
1113                 }
1114
1115                 count++;
1116                 if (count == CPUIDLE_STATE_MAX)
1117                         break;
1118         }
1119
1120         dev->state_count = count;
1121
1122         if (!count)
1123                 return -EINVAL;
1124
1125         return 0;
1126 }
1127
1128 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1129 {
1130         int ret = 0;
1131
1132         if (boot_option_idle_override)
1133                 return 0;
1134
1135         if (!pr)
1136                 return -EINVAL;
1137
1138         if (nocst) {
1139                 return -ENODEV;
1140         }
1141
1142         if (!pr->flags.power_setup_done)
1143                 return -ENODEV;
1144
1145         cpuidle_pause_and_lock();
1146         cpuidle_disable_device(&pr->power.dev);
1147         acpi_processor_get_power_info(pr);
1148         if (pr->flags.power) {
1149                 acpi_processor_setup_cpuidle(pr);
1150                 ret = cpuidle_enable_device(&pr->power.dev);
1151         }
1152         cpuidle_resume_and_unlock();
1153
1154         return ret;
1155 }
1156
1157 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1158                               struct acpi_device *device)
1159 {
1160         acpi_status status = 0;
1161         static int first_run;
1162         struct proc_dir_entry *entry = NULL;
1163         unsigned int i;
1164
1165         if (boot_option_idle_override)
1166                 return 0;
1167
1168         if (!first_run) {
1169                 if (idle_halt) {
1170                         /*
1171                          * When the boot option of "idle=halt" is added, halt
1172                          * is used for CPU IDLE.
1173                          * In such case C2/C3 is meaningless. So the max_cstate
1174                          * is set to one.
1175                          */
1176                         max_cstate = 1;
1177                 }
1178                 dmi_check_system(processor_power_dmi_table);
1179                 max_cstate = acpi_processor_cstate_check(max_cstate);
1180                 if (max_cstate < ACPI_C_STATES_MAX)
1181                         printk(KERN_NOTICE
1182                                "ACPI: processor limited to max C-state %d\n",
1183                                max_cstate);
1184                 first_run++;
1185         }
1186
1187         if (!pr)
1188                 return -EINVAL;
1189
1190         if (acpi_gbl_FADT.cst_control && !nocst) {
1191                 status =
1192                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1193                 if (ACPI_FAILURE(status)) {
1194                         ACPI_EXCEPTION((AE_INFO, status,
1195                                         "Notifying BIOS of _CST ability failed"));
1196                 }
1197         }
1198
1199         acpi_processor_get_power_info(pr);
1200         pr->flags.power_setup_done = 1;
1201
1202         /*
1203          * Install the idle handler if processor power management is supported.
1204          * Note that we use previously set idle handler will be used on
1205          * platforms that only support C1.
1206          */
1207         if (pr->flags.power) {
1208                 acpi_processor_setup_cpuidle(pr);
1209                 if (cpuidle_register_device(&pr->power.dev))
1210                         return -EIO;
1211
1212                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1213                 for (i = 1; i <= pr->power.count; i++)
1214                         if (pr->power.states[i].valid)
1215                                 printk(" C%d[C%d]", i,
1216                                        pr->power.states[i].type);
1217                 printk(")\n");
1218         }
1219
1220         /* 'power' [R] */
1221         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1222                                  S_IRUGO, acpi_device_dir(device),
1223                                  &acpi_processor_power_fops,
1224                                  acpi_driver_data(device));
1225         if (!entry)
1226                 return -EIO;
1227         return 0;
1228 }
1229
1230 int acpi_processor_power_exit(struct acpi_processor *pr,
1231                               struct acpi_device *device)
1232 {
1233         if (boot_option_idle_override)
1234                 return 0;
1235
1236         cpuidle_unregister_device(&pr->power.dev);
1237         pr->flags.power_setup_done = 0;
1238
1239         if (acpi_device_dir(device))
1240                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1241                                   acpi_device_dir(device));
1242
1243         return 0;
1244 }