Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6] / 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 lapic_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 lapic_timer_propagate_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 lapic_timer_state_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 lapic_timer_check_state(int state, struct acpi_processor *pr,
194                                    struct acpi_processor_cx *cstate) { }
195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
196 static void lapic_timer_state_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 = -1;
519         static int bm_control_flag = -1;
520
521
522         if (!cx->address)
523                 return;
524
525         /*
526          * C3 latency must be less than or equal to 1000
527          * microseconds.
528          */
529         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
530                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
531                                   "latency too large [%d]\n", cx->latency));
532                 return;
533         }
534
535         /*
536          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
537          * DMA transfers are used by any ISA device to avoid livelock.
538          * Note that we could disable Type-F DMA (as recommended by
539          * the erratum), but this is known to disrupt certain ISA
540          * devices thus we take the conservative approach.
541          */
542         else if (errata.piix4.fdma) {
543                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
544                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
545                 return;
546         }
547
548         /* All the logic here assumes flags.bm_check is same across all CPUs */
549         if (bm_check_flag == -1) {
550                 /* Determine whether bm_check is needed based on CPU  */
551                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
552                 bm_check_flag = pr->flags.bm_check;
553                 bm_control_flag = pr->flags.bm_control;
554         } else {
555                 pr->flags.bm_check = bm_check_flag;
556                 pr->flags.bm_control = bm_control_flag;
557         }
558
559         if (pr->flags.bm_check) {
560                 if (!pr->flags.bm_control) {
561                         if (pr->flags.has_cst != 1) {
562                                 /* bus mastering control is necessary */
563                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
564                                         "C3 support requires BM control\n"));
565                                 return;
566                         } else {
567                                 /* Here we enter C3 without bus mastering */
568                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
569                                         "C3 support without BM control\n"));
570                         }
571                 }
572         } else {
573                 /*
574                  * WBINVD should be set in fadt, for C3 state to be
575                  * supported on when bm_check is not required.
576                  */
577                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
578                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
579                                           "Cache invalidation should work properly"
580                                           " for C3 to be enabled on SMP systems\n"));
581                         return;
582                 }
583         }
584
585         /*
586          * Otherwise we've met all of our C3 requirements.
587          * Normalize the C3 latency to expidite policy.  Enable
588          * checking of bus mastering status (bm_check) so we can
589          * use this in our C3 policy
590          */
591         cx->valid = 1;
592
593         cx->latency_ticks = cx->latency;
594         /*
595          * On older chipsets, BM_RLD needs to be set
596          * in order for Bus Master activity to wake the
597          * system from C3.  Newer chipsets handle DMA
598          * during C3 automatically and BM_RLD is a NOP.
599          * In either case, the proper way to
600          * handle BM_RLD is to set it and leave it set.
601          */
602         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
603
604         return;
605 }
606
607 static int acpi_processor_power_verify(struct acpi_processor *pr)
608 {
609         unsigned int i;
610         unsigned int working = 0;
611
612         pr->power.timer_broadcast_on_state = INT_MAX;
613
614         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
615                 struct acpi_processor_cx *cx = &pr->power.states[i];
616
617                 switch (cx->type) {
618                 case ACPI_STATE_C1:
619                         cx->valid = 1;
620                         break;
621
622                 case ACPI_STATE_C2:
623                         acpi_processor_power_verify_c2(cx);
624                         break;
625
626                 case ACPI_STATE_C3:
627                         acpi_processor_power_verify_c3(pr, cx);
628                         break;
629                 }
630                 if (!cx->valid)
631                         continue;
632
633                 lapic_timer_check_state(i, pr, cx);
634                 tsc_check_state(cx->type);
635                 working++;
636         }
637
638         lapic_timer_propagate_broadcast(pr);
639
640         return (working);
641 }
642
643 static int acpi_processor_get_power_info(struct acpi_processor *pr)
644 {
645         unsigned int i;
646         int result;
647
648
649         /* NOTE: the idle thread may not be running while calling
650          * this function */
651
652         /* Zero initialize all the C-states info. */
653         memset(pr->power.states, 0, sizeof(pr->power.states));
654
655         result = acpi_processor_get_power_info_cst(pr);
656         if (result == -ENODEV)
657                 result = acpi_processor_get_power_info_fadt(pr);
658
659         if (result)
660                 return result;
661
662         acpi_processor_get_power_info_default(pr);
663
664         pr->power.count = acpi_processor_power_verify(pr);
665
666         /*
667          * if one state of type C2 or C3 is available, mark this
668          * CPU as being "idle manageable"
669          */
670         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
671                 if (pr->power.states[i].valid) {
672                         pr->power.count = i;
673                         if (pr->power.states[i].type >= ACPI_STATE_C2)
674                                 pr->flags.power = 1;
675                 }
676         }
677
678         return 0;
679 }
680
681 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
682 {
683         struct acpi_processor *pr = seq->private;
684         unsigned int i;
685
686
687         if (!pr)
688                 goto end;
689
690         seq_printf(seq, "active state:            C%zd\n"
691                    "max_cstate:              C%d\n"
692                    "maximum allowed latency: %d usec\n",
693                    pr->power.state ? pr->power.state - pr->power.states : 0,
694                    max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
695
696         seq_puts(seq, "states:\n");
697
698         for (i = 1; i <= pr->power.count; i++) {
699                 seq_printf(seq, "   %cC%d:                  ",
700                            (&pr->power.states[i] ==
701                             pr->power.state ? '*' : ' '), i);
702
703                 if (!pr->power.states[i].valid) {
704                         seq_puts(seq, "<not supported>\n");
705                         continue;
706                 }
707
708                 switch (pr->power.states[i].type) {
709                 case ACPI_STATE_C1:
710                         seq_printf(seq, "type[C1] ");
711                         break;
712                 case ACPI_STATE_C2:
713                         seq_printf(seq, "type[C2] ");
714                         break;
715                 case ACPI_STATE_C3:
716                         seq_printf(seq, "type[C3] ");
717                         break;
718                 default:
719                         seq_printf(seq, "type[--] ");
720                         break;
721                 }
722
723                 if (pr->power.states[i].promotion.state)
724                         seq_printf(seq, "promotion[C%zd] ",
725                                    (pr->power.states[i].promotion.state -
726                                     pr->power.states));
727                 else
728                         seq_puts(seq, "promotion[--] ");
729
730                 if (pr->power.states[i].demotion.state)
731                         seq_printf(seq, "demotion[C%zd] ",
732                                    (pr->power.states[i].demotion.state -
733                                     pr->power.states));
734                 else
735                         seq_puts(seq, "demotion[--] ");
736
737                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
738                            pr->power.states[i].latency,
739                            pr->power.states[i].usage,
740                            (unsigned long long)pr->power.states[i].time);
741         }
742
743       end:
744         return 0;
745 }
746
747 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
748 {
749         return single_open(file, acpi_processor_power_seq_show,
750                            PDE(inode)->data);
751 }
752
753 static const struct file_operations acpi_processor_power_fops = {
754         .owner = THIS_MODULE,
755         .open = acpi_processor_power_open_fs,
756         .read = seq_read,
757         .llseek = seq_lseek,
758         .release = single_release,
759 };
760
761
762 /**
763  * acpi_idle_bm_check - checks if bus master activity was detected
764  */
765 static int acpi_idle_bm_check(void)
766 {
767         u32 bm_status = 0;
768
769         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
770         if (bm_status)
771                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
772         /*
773          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
774          * the true state of bus mastering activity; forcing us to
775          * manually check the BMIDEA bit of each IDE channel.
776          */
777         else if (errata.piix4.bmisx) {
778                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
779                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
780                         bm_status = 1;
781         }
782         return bm_status;
783 }
784
785 /**
786  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
787  * @cx: cstate data
788  *
789  * Caller disables interrupt before call and enables interrupt after return.
790  */
791 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
792 {
793         /* Don't trace irqs off for idle */
794         stop_critical_timings();
795         if (cx->entry_method == ACPI_CSTATE_FFH) {
796                 /* Call into architectural FFH based C-state */
797                 acpi_processor_ffh_cstate_enter(cx);
798         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
799                 acpi_safe_halt();
800         } else {
801                 int unused;
802                 /* IO port based C-state */
803                 inb(cx->address);
804                 /* Dummy wait op - must do something useless after P_LVL2 read
805                    because chipsets cannot guarantee that STPCLK# signal
806                    gets asserted in time to freeze execution properly. */
807                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
808         }
809         start_critical_timings();
810 }
811
812 /**
813  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
814  * @dev: the target CPU
815  * @state: the state data
816  *
817  * This is equivalent to the HALT instruction.
818  */
819 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
820                               struct cpuidle_state *state)
821 {
822         ktime_t  kt1, kt2;
823         s64 idle_time;
824         struct acpi_processor *pr;
825         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
826
827         pr = __get_cpu_var(processors);
828
829         if (unlikely(!pr))
830                 return 0;
831
832         local_irq_disable();
833
834         /* Do not access any ACPI IO ports in suspend path */
835         if (acpi_idle_suspend) {
836                 local_irq_enable();
837                 cpu_relax();
838                 return 0;
839         }
840
841         lapic_timer_state_broadcast(pr, cx, 1);
842         kt1 = ktime_get_real();
843         acpi_idle_do_entry(cx);
844         kt2 = ktime_get_real();
845         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
846
847         local_irq_enable();
848         cx->usage++;
849         lapic_timer_state_broadcast(pr, cx, 0);
850
851         return idle_time;
852 }
853
854 /**
855  * acpi_idle_enter_simple - enters an ACPI state without BM handling
856  * @dev: the target CPU
857  * @state: the state data
858  */
859 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
860                                   struct cpuidle_state *state)
861 {
862         struct acpi_processor *pr;
863         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
864         ktime_t  kt1, kt2;
865         s64 idle_time;
866         s64 sleep_ticks = 0;
867
868         pr = __get_cpu_var(processors);
869
870         if (unlikely(!pr))
871                 return 0;
872
873         if (acpi_idle_suspend)
874                 return(acpi_idle_enter_c1(dev, state));
875
876         local_irq_disable();
877         current_thread_info()->status &= ~TS_POLLING;
878         /*
879          * TS_POLLING-cleared state must be visible before we test
880          * NEED_RESCHED:
881          */
882         smp_mb();
883
884         if (unlikely(need_resched())) {
885                 current_thread_info()->status |= TS_POLLING;
886                 local_irq_enable();
887                 return 0;
888         }
889
890         /*
891          * Must be done before busmaster disable as we might need to
892          * access HPET !
893          */
894         lapic_timer_state_broadcast(pr, cx, 1);
895
896         if (cx->type == ACPI_STATE_C3)
897                 ACPI_FLUSH_CPU_CACHE();
898
899         kt1 = ktime_get_real();
900         /* Tell the scheduler that we are going deep-idle: */
901         sched_clock_idle_sleep_event();
902         acpi_idle_do_entry(cx);
903         kt2 = ktime_get_real();
904         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
905
906         sleep_ticks = us_to_pm_timer_ticks(idle_time);
907
908         /* Tell the scheduler how much we idled: */
909         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
910
911         local_irq_enable();
912         current_thread_info()->status |= TS_POLLING;
913
914         cx->usage++;
915
916         lapic_timer_state_broadcast(pr, cx, 0);
917         cx->time += sleep_ticks;
918         return idle_time;
919 }
920
921 static int c3_cpu_count;
922 static DEFINE_SPINLOCK(c3_lock);
923
924 /**
925  * acpi_idle_enter_bm - enters C3 with proper BM handling
926  * @dev: the target CPU
927  * @state: the state data
928  *
929  * If BM is detected, the deepest non-C3 idle state is entered instead.
930  */
931 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
932                               struct cpuidle_state *state)
933 {
934         struct acpi_processor *pr;
935         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
936         ktime_t  kt1, kt2;
937         s64 idle_time;
938         s64 sleep_ticks = 0;
939
940
941         pr = __get_cpu_var(processors);
942
943         if (unlikely(!pr))
944                 return 0;
945
946         if (acpi_idle_suspend)
947                 return(acpi_idle_enter_c1(dev, state));
948
949         if (acpi_idle_bm_check()) {
950                 if (dev->safe_state) {
951                         dev->last_state = dev->safe_state;
952                         return dev->safe_state->enter(dev, dev->safe_state);
953                 } else {
954                         local_irq_disable();
955                         acpi_safe_halt();
956                         local_irq_enable();
957                         return 0;
958                 }
959         }
960
961         local_irq_disable();
962         current_thread_info()->status &= ~TS_POLLING;
963         /*
964          * TS_POLLING-cleared state must be visible before we test
965          * NEED_RESCHED:
966          */
967         smp_mb();
968
969         if (unlikely(need_resched())) {
970                 current_thread_info()->status |= TS_POLLING;
971                 local_irq_enable();
972                 return 0;
973         }
974
975         acpi_unlazy_tlb(smp_processor_id());
976
977         /* Tell the scheduler that we are going deep-idle: */
978         sched_clock_idle_sleep_event();
979         /*
980          * Must be done before busmaster disable as we might need to
981          * access HPET !
982          */
983         lapic_timer_state_broadcast(pr, cx, 1);
984
985         kt1 = ktime_get_real();
986         /*
987          * disable bus master
988          * bm_check implies we need ARB_DIS
989          * !bm_check implies we need cache flush
990          * bm_control implies whether we can do ARB_DIS
991          *
992          * That leaves a case where bm_check is set and bm_control is
993          * not set. In that case we cannot do much, we enter C3
994          * without doing anything.
995          */
996         if (pr->flags.bm_check && pr->flags.bm_control) {
997                 spin_lock(&c3_lock);
998                 c3_cpu_count++;
999                 /* Disable bus master arbitration when all CPUs are in C3 */
1000                 if (c3_cpu_count == num_online_cpus())
1001                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
1002                 spin_unlock(&c3_lock);
1003         } else if (!pr->flags.bm_check) {
1004                 ACPI_FLUSH_CPU_CACHE();
1005         }
1006
1007         acpi_idle_do_entry(cx);
1008
1009         /* Re-enable bus master arbitration */
1010         if (pr->flags.bm_check && pr->flags.bm_control) {
1011                 spin_lock(&c3_lock);
1012                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
1013                 c3_cpu_count--;
1014                 spin_unlock(&c3_lock);
1015         }
1016         kt2 = ktime_get_real();
1017         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
1018
1019         sleep_ticks = us_to_pm_timer_ticks(idle_time);
1020         /* Tell the scheduler how much we idled: */
1021         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1022
1023         local_irq_enable();
1024         current_thread_info()->status |= TS_POLLING;
1025
1026         cx->usage++;
1027
1028         lapic_timer_state_broadcast(pr, cx, 0);
1029         cx->time += sleep_ticks;
1030         return idle_time;
1031 }
1032
1033 struct cpuidle_driver acpi_idle_driver = {
1034         .name =         "acpi_idle",
1035         .owner =        THIS_MODULE,
1036 };
1037
1038 /**
1039  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1040  * @pr: the ACPI processor
1041  */
1042 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1043 {
1044         int i, count = CPUIDLE_DRIVER_STATE_START;
1045         struct acpi_processor_cx *cx;
1046         struct cpuidle_state *state;
1047         struct cpuidle_device *dev = &pr->power.dev;
1048
1049         if (!pr->flags.power_setup_done)
1050                 return -EINVAL;
1051
1052         if (pr->flags.power == 0) {
1053                 return -EINVAL;
1054         }
1055
1056         dev->cpu = pr->id;
1057         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1058                 dev->states[i].name[0] = '\0';
1059                 dev->states[i].desc[0] = '\0';
1060         }
1061
1062         if (max_cstate == 0)
1063                 max_cstate = 1;
1064
1065         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1066                 cx = &pr->power.states[i];
1067                 state = &dev->states[count];
1068
1069                 if (!cx->valid)
1070                         continue;
1071
1072 #ifdef CONFIG_HOTPLUG_CPU
1073                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1074                     !pr->flags.has_cst &&
1075                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1076                         continue;
1077 #endif
1078                 cpuidle_set_statedata(state, cx);
1079
1080                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1081                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1082                 state->exit_latency = cx->latency;
1083                 state->target_residency = cx->latency * latency_factor;
1084                 state->power_usage = cx->power;
1085
1086                 state->flags = 0;
1087                 switch (cx->type) {
1088                         case ACPI_STATE_C1:
1089                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1090                         if (cx->entry_method == ACPI_CSTATE_FFH)
1091                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1092
1093                         state->enter = acpi_idle_enter_c1;
1094                         dev->safe_state = state;
1095                         break;
1096
1097                         case ACPI_STATE_C2:
1098                         state->flags |= CPUIDLE_FLAG_BALANCED;
1099                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1100                         state->enter = acpi_idle_enter_simple;
1101                         dev->safe_state = state;
1102                         break;
1103
1104                         case ACPI_STATE_C3:
1105                         state->flags |= CPUIDLE_FLAG_DEEP;
1106                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1107                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1108                         state->enter = pr->flags.bm_check ?
1109                                         acpi_idle_enter_bm :
1110                                         acpi_idle_enter_simple;
1111                         break;
1112                 }
1113
1114                 count++;
1115                 if (count == CPUIDLE_STATE_MAX)
1116                         break;
1117         }
1118
1119         dev->state_count = count;
1120
1121         if (!count)
1122                 return -EINVAL;
1123
1124         return 0;
1125 }
1126
1127 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1128 {
1129         int ret = 0;
1130
1131         if (boot_option_idle_override)
1132                 return 0;
1133
1134         if (!pr)
1135                 return -EINVAL;
1136
1137         if (nocst) {
1138                 return -ENODEV;
1139         }
1140
1141         if (!pr->flags.power_setup_done)
1142                 return -ENODEV;
1143
1144         cpuidle_pause_and_lock();
1145         cpuidle_disable_device(&pr->power.dev);
1146         acpi_processor_get_power_info(pr);
1147         if (pr->flags.power) {
1148                 acpi_processor_setup_cpuidle(pr);
1149                 ret = cpuidle_enable_device(&pr->power.dev);
1150         }
1151         cpuidle_resume_and_unlock();
1152
1153         return ret;
1154 }
1155
1156 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1157                               struct acpi_device *device)
1158 {
1159         acpi_status status = 0;
1160         static int first_run;
1161         struct proc_dir_entry *entry = NULL;
1162         unsigned int i;
1163
1164         if (boot_option_idle_override)
1165                 return 0;
1166
1167         if (!first_run) {
1168                 if (idle_halt) {
1169                         /*
1170                          * When the boot option of "idle=halt" is added, halt
1171                          * is used for CPU IDLE.
1172                          * In such case C2/C3 is meaningless. So the max_cstate
1173                          * is set to one.
1174                          */
1175                         max_cstate = 1;
1176                 }
1177                 dmi_check_system(processor_power_dmi_table);
1178                 max_cstate = acpi_processor_cstate_check(max_cstate);
1179                 if (max_cstate < ACPI_C_STATES_MAX)
1180                         printk(KERN_NOTICE
1181                                "ACPI: processor limited to max C-state %d\n",
1182                                max_cstate);
1183                 first_run++;
1184         }
1185
1186         if (!pr)
1187                 return -EINVAL;
1188
1189         if (acpi_gbl_FADT.cst_control && !nocst) {
1190                 status =
1191                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1192                 if (ACPI_FAILURE(status)) {
1193                         ACPI_EXCEPTION((AE_INFO, status,
1194                                         "Notifying BIOS of _CST ability failed"));
1195                 }
1196         }
1197
1198         acpi_processor_get_power_info(pr);
1199         pr->flags.power_setup_done = 1;
1200
1201         /*
1202          * Install the idle handler if processor power management is supported.
1203          * Note that we use previously set idle handler will be used on
1204          * platforms that only support C1.
1205          */
1206         if (pr->flags.power) {
1207                 acpi_processor_setup_cpuidle(pr);
1208                 if (cpuidle_register_device(&pr->power.dev))
1209                         return -EIO;
1210
1211                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1212                 for (i = 1; i <= pr->power.count; i++)
1213                         if (pr->power.states[i].valid)
1214                                 printk(" C%d[C%d]", i,
1215                                        pr->power.states[i].type);
1216                 printk(")\n");
1217         }
1218
1219         /* 'power' [R] */
1220         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1221                                  S_IRUGO, acpi_device_dir(device),
1222                                  &acpi_processor_power_fops,
1223                                  acpi_driver_data(device));
1224         if (!entry)
1225                 return -EIO;
1226         return 0;
1227 }
1228
1229 int acpi_processor_power_exit(struct acpi_processor *pr,
1230                               struct acpi_device *device)
1231 {
1232         if (boot_option_idle_override)
1233                 return 0;
1234
1235         cpuidle_unregister_device(&pr->power.dev);
1236         pr->flags.power_setup_done = 0;
1237
1238         if (acpi_device_dir(device))
1239                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1240                                   acpi_device_dir(device));
1241
1242         return 0;
1243 }