644516d9bde6cf18a824d29c3ae1730de30fd1a6
[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/module.h>
32 #include <linux/acpi.h>
33 #include <linux/dmi.h>
34 #include <linux/sched.h>       /* need_resched() */
35 #include <linux/clockchips.h>
36 #include <linux/cpuidle.h>
37 #include <linux/syscore_ops.h>
38
39 /*
40  * Include the apic definitions for x86 to have the APIC timer related defines
41  * available also for UP (on SMP it gets magically included via linux/smp.h).
42  * asm/acpi.h is not an option, as it would require more include magic. Also
43  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
44  */
45 #ifdef CONFIG_X86
46 #include <asm/apic.h>
47 #endif
48
49 #include <acpi/acpi_bus.h>
50 #include <acpi/processor.h>
51
52 #define PREFIX "ACPI: "
53
54 #define ACPI_PROCESSOR_CLASS            "processor"
55 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
56 ACPI_MODULE_NAME("processor_idle");
57
58 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
59 module_param(max_cstate, uint, 0000);
60 static unsigned int nocst __read_mostly;
61 module_param(nocst, uint, 0000);
62 static int bm_check_disable __read_mostly;
63 module_param(bm_check_disable, uint, 0000);
64
65 static unsigned int latency_factor __read_mostly = 2;
66 module_param(latency_factor, uint, 0644);
67
68 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
69
70 static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
71                                                                 acpi_cstate);
72
73 static int disabled_by_idle_boot_param(void)
74 {
75         return boot_option_idle_override == IDLE_POLL ||
76                 boot_option_idle_override == IDLE_HALT;
77 }
78
79 /*
80  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
81  * For now disable this. Probably a bug somewhere else.
82  *
83  * To skip this limit, boot/load with a large max_cstate limit.
84  */
85 static int set_max_cstate(const struct dmi_system_id *id)
86 {
87         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
88                 return 0;
89
90         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
91                " Override with \"processor.max_cstate=%d\"\n", id->ident,
92                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
93
94         max_cstate = (long)id->driver_data;
95
96         return 0;
97 }
98
99 static struct dmi_system_id processor_power_dmi_table[] = {
100         { set_max_cstate, "Clevo 5600D", {
101           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
102           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
103          (void *)2},
104         { set_max_cstate, "Pavilion zv5000", {
105           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
106           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
107          (void *)1},
108         { set_max_cstate, "Asus L8400B", {
109           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
110           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
111          (void *)1},
112         {},
113 };
114
115
116 /*
117  * Callers should disable interrupts before the call and enable
118  * interrupts after return.
119  */
120 static void acpi_safe_halt(void)
121 {
122         if (!tif_need_resched()) {
123                 safe_halt();
124                 local_irq_disable();
125         }
126 }
127
128 #ifdef ARCH_APICTIMER_STOPS_ON_C3
129
130 /*
131  * Some BIOS implementations switch to C3 in the published C2 state.
132  * This seems to be a common problem on AMD boxen, but other vendors
133  * are affected too. We pick the most conservative approach: we assume
134  * that the local APIC stops in both C2 and C3.
135  */
136 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
137                                    struct acpi_processor_cx *cx)
138 {
139         struct acpi_processor_power *pwr = &pr->power;
140         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
141
142         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
143                 return;
144
145         if (amd_e400_c1e_detected)
146                 type = ACPI_STATE_C1;
147
148         /*
149          * Check, if one of the previous states already marked the lapic
150          * unstable
151          */
152         if (pwr->timer_broadcast_on_state < state)
153                 return;
154
155         if (cx->type >= type)
156                 pr->power.timer_broadcast_on_state = state;
157 }
158
159 static void __lapic_timer_propagate_broadcast(void *arg)
160 {
161         struct acpi_processor *pr = (struct acpi_processor *) arg;
162         unsigned long reason;
163
164         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
165                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
166
167         clockevents_notify(reason, &pr->id);
168 }
169
170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
171 {
172         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
173                                  (void *)pr, 1);
174 }
175
176 /* Power(C) State timer broadcast control */
177 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
178                                        struct acpi_processor_cx *cx,
179                                        int broadcast)
180 {
181         int state = cx - pr->power.states;
182
183         if (state >= pr->power.timer_broadcast_on_state) {
184                 unsigned long reason;
185
186                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
187                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
188                 clockevents_notify(reason, &pr->id);
189         }
190 }
191
192 #else
193
194 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
195                                    struct acpi_processor_cx *cstate) { }
196 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
197 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
198                                        struct acpi_processor_cx *cx,
199                                        int broadcast)
200 {
201 }
202
203 #endif
204
205 #ifdef CONFIG_PM_SLEEP
206 static u32 saved_bm_rld;
207
208 static int acpi_processor_suspend(void)
209 {
210         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
211         return 0;
212 }
213
214 static void acpi_processor_resume(void)
215 {
216         u32 resumed_bm_rld;
217
218         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
219         if (resumed_bm_rld == saved_bm_rld)
220                 return;
221
222         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
223 }
224
225 static struct syscore_ops acpi_processor_syscore_ops = {
226         .suspend = acpi_processor_suspend,
227         .resume = acpi_processor_resume,
228 };
229
230 void acpi_processor_syscore_init(void)
231 {
232         register_syscore_ops(&acpi_processor_syscore_ops);
233 }
234
235 void acpi_processor_syscore_exit(void)
236 {
237         unregister_syscore_ops(&acpi_processor_syscore_ops);
238 }
239 #endif /* CONFIG_PM_SLEEP */
240
241 #if defined(CONFIG_X86)
242 static void tsc_check_state(int state)
243 {
244         switch (boot_cpu_data.x86_vendor) {
245         case X86_VENDOR_AMD:
246         case X86_VENDOR_INTEL:
247                 /*
248                  * AMD Fam10h TSC will tick in all
249                  * C/P/S0/S1 states when this bit is set.
250                  */
251                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
252                         return;
253
254                 /*FALL THROUGH*/
255         default:
256                 /* TSC could halt in idle, so notify users */
257                 if (state > ACPI_STATE_C1)
258                         mark_tsc_unstable("TSC halts in idle");
259         }
260 }
261 #else
262 static void tsc_check_state(int state) { return; }
263 #endif
264
265 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
266 {
267
268         if (!pr->pblk)
269                 return -ENODEV;
270
271         /* if info is obtained from pblk/fadt, type equals state */
272         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
273         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
274
275 #ifndef CONFIG_HOTPLUG_CPU
276         /*
277          * Check for P_LVL2_UP flag before entering C2 and above on
278          * an SMP system.
279          */
280         if ((num_online_cpus() > 1) &&
281             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
282                 return -ENODEV;
283 #endif
284
285         /* determine C2 and C3 address from pblk */
286         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
287         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
288
289         /* determine latencies from FADT */
290         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
291         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
292
293         /*
294          * FADT specified C2 latency must be less than or equal to
295          * 100 microseconds.
296          */
297         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
298                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
299                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
300                 /* invalidate C2 */
301                 pr->power.states[ACPI_STATE_C2].address = 0;
302         }
303
304         /*
305          * FADT supplied C3 latency must be less than or equal to
306          * 1000 microseconds.
307          */
308         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
309                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
310                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
311                 /* invalidate C3 */
312                 pr->power.states[ACPI_STATE_C3].address = 0;
313         }
314
315         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
316                           "lvl2[0x%08x] lvl3[0x%08x]\n",
317                           pr->power.states[ACPI_STATE_C2].address,
318                           pr->power.states[ACPI_STATE_C3].address));
319
320         return 0;
321 }
322
323 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
324 {
325         if (!pr->power.states[ACPI_STATE_C1].valid) {
326                 /* set the first C-State to C1 */
327                 /* all processors need to support C1 */
328                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
329                 pr->power.states[ACPI_STATE_C1].valid = 1;
330                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
331         }
332         /* the C0 state only exists as a filler in our array */
333         pr->power.states[ACPI_STATE_C0].valid = 1;
334         return 0;
335 }
336
337 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
338 {
339         acpi_status status = 0;
340         u64 count;
341         int current_count;
342         int i;
343         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
344         union acpi_object *cst;
345
346
347         if (nocst)
348                 return -ENODEV;
349
350         current_count = 0;
351
352         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
353         if (ACPI_FAILURE(status)) {
354                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
355                 return -ENODEV;
356         }
357
358         cst = buffer.pointer;
359
360         /* There must be at least 2 elements */
361         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
362                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
363                 status = -EFAULT;
364                 goto end;
365         }
366
367         count = cst->package.elements[0].integer.value;
368
369         /* Validate number of power states. */
370         if (count < 1 || count != cst->package.count - 1) {
371                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
372                 status = -EFAULT;
373                 goto end;
374         }
375
376         /* Tell driver that at least _CST is supported. */
377         pr->flags.has_cst = 1;
378
379         for (i = 1; i <= count; i++) {
380                 union acpi_object *element;
381                 union acpi_object *obj;
382                 struct acpi_power_register *reg;
383                 struct acpi_processor_cx cx;
384
385                 memset(&cx, 0, sizeof(cx));
386
387                 element = &(cst->package.elements[i]);
388                 if (element->type != ACPI_TYPE_PACKAGE)
389                         continue;
390
391                 if (element->package.count != 4)
392                         continue;
393
394                 obj = &(element->package.elements[0]);
395
396                 if (obj->type != ACPI_TYPE_BUFFER)
397                         continue;
398
399                 reg = (struct acpi_power_register *)obj->buffer.pointer;
400
401                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
402                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
403                         continue;
404
405                 /* There should be an easy way to extract an integer... */
406                 obj = &(element->package.elements[1]);
407                 if (obj->type != ACPI_TYPE_INTEGER)
408                         continue;
409
410                 cx.type = obj->integer.value;
411                 /*
412                  * Some buggy BIOSes won't list C1 in _CST -
413                  * Let acpi_processor_get_power_info_default() handle them later
414                  */
415                 if (i == 1 && cx.type != ACPI_STATE_C1)
416                         current_count++;
417
418                 cx.address = reg->address;
419                 cx.index = current_count + 1;
420
421                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
422                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
423                         if (acpi_processor_ffh_cstate_probe
424                                         (pr->id, &cx, reg) == 0) {
425                                 cx.entry_method = ACPI_CSTATE_FFH;
426                         } else if (cx.type == ACPI_STATE_C1) {
427                                 /*
428                                  * C1 is a special case where FIXED_HARDWARE
429                                  * can be handled in non-MWAIT way as well.
430                                  * In that case, save this _CST entry info.
431                                  * Otherwise, ignore this info and continue.
432                                  */
433                                 cx.entry_method = ACPI_CSTATE_HALT;
434                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
435                         } else {
436                                 continue;
437                         }
438                         if (cx.type == ACPI_STATE_C1 &&
439                             (boot_option_idle_override == IDLE_NOMWAIT)) {
440                                 /*
441                                  * In most cases the C1 space_id obtained from
442                                  * _CST object is FIXED_HARDWARE access mode.
443                                  * But when the option of idle=halt is added,
444                                  * the entry_method type should be changed from
445                                  * CSTATE_FFH to CSTATE_HALT.
446                                  * When the option of idle=nomwait is added,
447                                  * the C1 entry_method type should be
448                                  * CSTATE_HALT.
449                                  */
450                                 cx.entry_method = ACPI_CSTATE_HALT;
451                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
452                         }
453                 } else {
454                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
455                                  cx.address);
456                 }
457
458                 if (cx.type == ACPI_STATE_C1) {
459                         cx.valid = 1;
460                 }
461
462                 obj = &(element->package.elements[2]);
463                 if (obj->type != ACPI_TYPE_INTEGER)
464                         continue;
465
466                 cx.latency = obj->integer.value;
467
468                 obj = &(element->package.elements[3]);
469                 if (obj->type != ACPI_TYPE_INTEGER)
470                         continue;
471
472                 current_count++;
473                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
474
475                 /*
476                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
477                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
478                  */
479                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
480                         printk(KERN_WARNING
481                                "Limiting number of power states to max (%d)\n",
482                                ACPI_PROCESSOR_MAX_POWER);
483                         printk(KERN_WARNING
484                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
485                         break;
486                 }
487         }
488
489         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
490                           current_count));
491
492         /* Validate number of power states discovered */
493         if (current_count < 2)
494                 status = -EFAULT;
495
496       end:
497         kfree(buffer.pointer);
498
499         return status;
500 }
501
502 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
503                                            struct acpi_processor_cx *cx)
504 {
505         static int bm_check_flag = -1;
506         static int bm_control_flag = -1;
507
508
509         if (!cx->address)
510                 return;
511
512         /*
513          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
514          * DMA transfers are used by any ISA device to avoid livelock.
515          * Note that we could disable Type-F DMA (as recommended by
516          * the erratum), but this is known to disrupt certain ISA
517          * devices thus we take the conservative approach.
518          */
519         else if (errata.piix4.fdma) {
520                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
521                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
522                 return;
523         }
524
525         /* All the logic here assumes flags.bm_check is same across all CPUs */
526         if (bm_check_flag == -1) {
527                 /* Determine whether bm_check is needed based on CPU  */
528                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
529                 bm_check_flag = pr->flags.bm_check;
530                 bm_control_flag = pr->flags.bm_control;
531         } else {
532                 pr->flags.bm_check = bm_check_flag;
533                 pr->flags.bm_control = bm_control_flag;
534         }
535
536         if (pr->flags.bm_check) {
537                 if (!pr->flags.bm_control) {
538                         if (pr->flags.has_cst != 1) {
539                                 /* bus mastering control is necessary */
540                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
541                                         "C3 support requires BM control\n"));
542                                 return;
543                         } else {
544                                 /* Here we enter C3 without bus mastering */
545                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
546                                         "C3 support without BM control\n"));
547                         }
548                 }
549         } else {
550                 /*
551                  * WBINVD should be set in fadt, for C3 state to be
552                  * supported on when bm_check is not required.
553                  */
554                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
555                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
556                                           "Cache invalidation should work properly"
557                                           " for C3 to be enabled on SMP systems\n"));
558                         return;
559                 }
560         }
561
562         /*
563          * Otherwise we've met all of our C3 requirements.
564          * Normalize the C3 latency to expidite policy.  Enable
565          * checking of bus mastering status (bm_check) so we can
566          * use this in our C3 policy
567          */
568         cx->valid = 1;
569
570         /*
571          * On older chipsets, BM_RLD needs to be set
572          * in order for Bus Master activity to wake the
573          * system from C3.  Newer chipsets handle DMA
574          * during C3 automatically and BM_RLD is a NOP.
575          * In either case, the proper way to
576          * handle BM_RLD is to set it and leave it set.
577          */
578         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
579
580         return;
581 }
582
583 static int acpi_processor_power_verify(struct acpi_processor *pr)
584 {
585         unsigned int i;
586         unsigned int working = 0;
587
588         pr->power.timer_broadcast_on_state = INT_MAX;
589
590         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
591                 struct acpi_processor_cx *cx = &pr->power.states[i];
592
593                 switch (cx->type) {
594                 case ACPI_STATE_C1:
595                         cx->valid = 1;
596                         break;
597
598                 case ACPI_STATE_C2:
599                         if (!cx->address)
600                                 break;
601                         cx->valid = 1; 
602                         break;
603
604                 case ACPI_STATE_C3:
605                         acpi_processor_power_verify_c3(pr, cx);
606                         break;
607                 }
608                 if (!cx->valid)
609                         continue;
610
611                 lapic_timer_check_state(i, pr, cx);
612                 tsc_check_state(cx->type);
613                 working++;
614         }
615
616         lapic_timer_propagate_broadcast(pr);
617
618         return (working);
619 }
620
621 static int acpi_processor_get_power_info(struct acpi_processor *pr)
622 {
623         unsigned int i;
624         int result;
625
626
627         /* NOTE: the idle thread may not be running while calling
628          * this function */
629
630         /* Zero initialize all the C-states info. */
631         memset(pr->power.states, 0, sizeof(pr->power.states));
632
633         result = acpi_processor_get_power_info_cst(pr);
634         if (result == -ENODEV)
635                 result = acpi_processor_get_power_info_fadt(pr);
636
637         if (result)
638                 return result;
639
640         acpi_processor_get_power_info_default(pr);
641
642         pr->power.count = acpi_processor_power_verify(pr);
643
644         /*
645          * if one state of type C2 or C3 is available, mark this
646          * CPU as being "idle manageable"
647          */
648         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
649                 if (pr->power.states[i].valid) {
650                         pr->power.count = i;
651                         if (pr->power.states[i].type >= ACPI_STATE_C2)
652                                 pr->flags.power = 1;
653                 }
654         }
655
656         return 0;
657 }
658
659 /**
660  * acpi_idle_bm_check - checks if bus master activity was detected
661  */
662 static int acpi_idle_bm_check(void)
663 {
664         u32 bm_status = 0;
665
666         if (bm_check_disable)
667                 return 0;
668
669         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
670         if (bm_status)
671                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
672         /*
673          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
674          * the true state of bus mastering activity; forcing us to
675          * manually check the BMIDEA bit of each IDE channel.
676          */
677         else if (errata.piix4.bmisx) {
678                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
679                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
680                         bm_status = 1;
681         }
682         return bm_status;
683 }
684
685 /**
686  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
687  * @cx: cstate data
688  *
689  * Caller disables interrupt before call and enables interrupt after return.
690  */
691 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
692 {
693         /* Don't trace irqs off for idle */
694         stop_critical_timings();
695         if (cx->entry_method == ACPI_CSTATE_FFH) {
696                 /* Call into architectural FFH based C-state */
697                 acpi_processor_ffh_cstate_enter(cx);
698         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
699                 acpi_safe_halt();
700         } else {
701                 /* IO port based C-state */
702                 inb(cx->address);
703                 /* Dummy wait op - must do something useless after P_LVL2 read
704                    because chipsets cannot guarantee that STPCLK# signal
705                    gets asserted in time to freeze execution properly. */
706                 inl(acpi_gbl_FADT.xpm_timer_block.address);
707         }
708         start_critical_timings();
709 }
710
711 /**
712  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
713  * @dev: the target CPU
714  * @drv: cpuidle driver containing cpuidle state info
715  * @index: index of target state
716  *
717  * This is equivalent to the HALT instruction.
718  */
719 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
720                 struct cpuidle_driver *drv, int index)
721 {
722         struct acpi_processor *pr;
723         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
724
725         pr = __this_cpu_read(processors);
726
727         if (unlikely(!pr))
728                 return -EINVAL;
729
730         if (cx->entry_method == ACPI_CSTATE_FFH) {
731                 if (current_set_polling_and_test())
732                         return -EINVAL;
733         }
734
735         lapic_timer_state_broadcast(pr, cx, 1);
736         acpi_idle_do_entry(cx);
737
738         lapic_timer_state_broadcast(pr, cx, 0);
739
740         return index;
741 }
742
743
744 /**
745  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
746  * @dev: the target CPU
747  * @index: the index of suggested state
748  */
749 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
750 {
751         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
752
753         ACPI_FLUSH_CPU_CACHE();
754
755         while (1) {
756
757                 if (cx->entry_method == ACPI_CSTATE_HALT)
758                         safe_halt();
759                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
760                         inb(cx->address);
761                         /* See comment in acpi_idle_do_entry() */
762                         inl(acpi_gbl_FADT.xpm_timer_block.address);
763                 } else
764                         return -ENODEV;
765         }
766
767         /* Never reached */
768         return 0;
769 }
770
771 /**
772  * acpi_idle_enter_simple - enters an ACPI state without BM handling
773  * @dev: the target CPU
774  * @drv: cpuidle driver with cpuidle state information
775  * @index: the index of suggested state
776  */
777 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
778                 struct cpuidle_driver *drv, int index)
779 {
780         struct acpi_processor *pr;
781         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
782
783         pr = __this_cpu_read(processors);
784
785         if (unlikely(!pr))
786                 return -EINVAL;
787
788         if (cx->entry_method == ACPI_CSTATE_FFH) {
789                 if (current_set_polling_and_test())
790                         return -EINVAL;
791         }
792
793         /*
794          * Must be done before busmaster disable as we might need to
795          * access HPET !
796          */
797         lapic_timer_state_broadcast(pr, cx, 1);
798
799         if (cx->type == ACPI_STATE_C3)
800                 ACPI_FLUSH_CPU_CACHE();
801
802         /* Tell the scheduler that we are going deep-idle: */
803         sched_clock_idle_sleep_event();
804         acpi_idle_do_entry(cx);
805
806         sched_clock_idle_wakeup_event(0);
807
808         lapic_timer_state_broadcast(pr, cx, 0);
809         return index;
810 }
811
812 static int c3_cpu_count;
813 static DEFINE_RAW_SPINLOCK(c3_lock);
814
815 /**
816  * acpi_idle_enter_bm - enters C3 with proper BM handling
817  * @dev: the target CPU
818  * @drv: cpuidle driver containing state data
819  * @index: the index of suggested state
820  *
821  * If BM is detected, the deepest non-C3 idle state is entered instead.
822  */
823 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
824                 struct cpuidle_driver *drv, int index)
825 {
826         struct acpi_processor *pr;
827         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
828
829         pr = __this_cpu_read(processors);
830
831         if (unlikely(!pr))
832                 return -EINVAL;
833
834         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
835                 if (drv->safe_state_index >= 0) {
836                         return drv->states[drv->safe_state_index].enter(dev,
837                                                 drv, drv->safe_state_index);
838                 } else {
839                         acpi_safe_halt();
840                         return -EBUSY;
841                 }
842         }
843
844         if (cx->entry_method == ACPI_CSTATE_FFH) {
845                 if (current_set_polling_and_test())
846                         return -EINVAL;
847         }
848
849         acpi_unlazy_tlb(smp_processor_id());
850
851         /* Tell the scheduler that we are going deep-idle: */
852         sched_clock_idle_sleep_event();
853         /*
854          * Must be done before busmaster disable as we might need to
855          * access HPET !
856          */
857         lapic_timer_state_broadcast(pr, cx, 1);
858
859         /*
860          * disable bus master
861          * bm_check implies we need ARB_DIS
862          * !bm_check implies we need cache flush
863          * bm_control implies whether we can do ARB_DIS
864          *
865          * That leaves a case where bm_check is set and bm_control is
866          * not set. In that case we cannot do much, we enter C3
867          * without doing anything.
868          */
869         if (pr->flags.bm_check && pr->flags.bm_control) {
870                 raw_spin_lock(&c3_lock);
871                 c3_cpu_count++;
872                 /* Disable bus master arbitration when all CPUs are in C3 */
873                 if (c3_cpu_count == num_online_cpus())
874                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
875                 raw_spin_unlock(&c3_lock);
876         } else if (!pr->flags.bm_check) {
877                 ACPI_FLUSH_CPU_CACHE();
878         }
879
880         acpi_idle_do_entry(cx);
881
882         /* Re-enable bus master arbitration */
883         if (pr->flags.bm_check && pr->flags.bm_control) {
884                 raw_spin_lock(&c3_lock);
885                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
886                 c3_cpu_count--;
887                 raw_spin_unlock(&c3_lock);
888         }
889
890         sched_clock_idle_wakeup_event(0);
891
892         lapic_timer_state_broadcast(pr, cx, 0);
893         return index;
894 }
895
896 struct cpuidle_driver acpi_idle_driver = {
897         .name =         "acpi_idle",
898         .owner =        THIS_MODULE,
899 };
900
901 /**
902  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
903  * device i.e. per-cpu data
904  *
905  * @pr: the ACPI processor
906  * @dev : the cpuidle device
907  */
908 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
909                                            struct cpuidle_device *dev)
910 {
911         int i, count = CPUIDLE_DRIVER_STATE_START;
912         struct acpi_processor_cx *cx;
913
914         if (!pr->flags.power_setup_done)
915                 return -EINVAL;
916
917         if (pr->flags.power == 0) {
918                 return -EINVAL;
919         }
920
921         if (!dev)
922                 return -EINVAL;
923
924         dev->cpu = pr->id;
925
926         if (max_cstate == 0)
927                 max_cstate = 1;
928
929         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
930                 cx = &pr->power.states[i];
931
932                 if (!cx->valid)
933                         continue;
934
935 #ifdef CONFIG_HOTPLUG_CPU
936                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
937                     !pr->flags.has_cst &&
938                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
939                         continue;
940 #endif
941                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
942
943                 count++;
944                 if (count == CPUIDLE_STATE_MAX)
945                         break;
946         }
947
948         dev->state_count = count;
949
950         if (!count)
951                 return -EINVAL;
952
953         return 0;
954 }
955
956 /**
957  * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
958  * global state data i.e. idle routines
959  *
960  * @pr: the ACPI processor
961  */
962 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
963 {
964         int i, count = CPUIDLE_DRIVER_STATE_START;
965         struct acpi_processor_cx *cx;
966         struct cpuidle_state *state;
967         struct cpuidle_driver *drv = &acpi_idle_driver;
968
969         if (!pr->flags.power_setup_done)
970                 return -EINVAL;
971
972         if (pr->flags.power == 0)
973                 return -EINVAL;
974
975         drv->safe_state_index = -1;
976         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
977                 drv->states[i].name[0] = '\0';
978                 drv->states[i].desc[0] = '\0';
979         }
980
981         if (max_cstate == 0)
982                 max_cstate = 1;
983
984         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
985                 cx = &pr->power.states[i];
986
987                 if (!cx->valid)
988                         continue;
989
990 #ifdef CONFIG_HOTPLUG_CPU
991                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
992                     !pr->flags.has_cst &&
993                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
994                         continue;
995 #endif
996
997                 state = &drv->states[count];
998                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
999                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1000                 state->exit_latency = cx->latency;
1001                 state->target_residency = cx->latency * latency_factor;
1002
1003                 state->flags = 0;
1004                 switch (cx->type) {
1005                         case ACPI_STATE_C1:
1006                         if (cx->entry_method == ACPI_CSTATE_FFH)
1007                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1008
1009                         state->enter = acpi_idle_enter_c1;
1010                         state->enter_dead = acpi_idle_play_dead;
1011                         drv->safe_state_index = count;
1012                         break;
1013
1014                         case ACPI_STATE_C2:
1015                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1016                         state->enter = acpi_idle_enter_simple;
1017                         state->enter_dead = acpi_idle_play_dead;
1018                         drv->safe_state_index = count;
1019                         break;
1020
1021                         case ACPI_STATE_C3:
1022                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1023                         state->enter = pr->flags.bm_check ?
1024                                         acpi_idle_enter_bm :
1025                                         acpi_idle_enter_simple;
1026                         break;
1027                 }
1028
1029                 count++;
1030                 if (count == CPUIDLE_STATE_MAX)
1031                         break;
1032         }
1033
1034         drv->state_count = count;
1035
1036         if (!count)
1037                 return -EINVAL;
1038
1039         return 0;
1040 }
1041
1042 int acpi_processor_hotplug(struct acpi_processor *pr)
1043 {
1044         int ret = 0;
1045         struct cpuidle_device *dev;
1046
1047         if (disabled_by_idle_boot_param())
1048                 return 0;
1049
1050         if (nocst)
1051                 return -ENODEV;
1052
1053         if (!pr->flags.power_setup_done)
1054                 return -ENODEV;
1055
1056         dev = per_cpu(acpi_cpuidle_device, pr->id);
1057         cpuidle_pause_and_lock();
1058         cpuidle_disable_device(dev);
1059         acpi_processor_get_power_info(pr);
1060         if (pr->flags.power) {
1061                 acpi_processor_setup_cpuidle_cx(pr, dev);
1062                 ret = cpuidle_enable_device(dev);
1063         }
1064         cpuidle_resume_and_unlock();
1065
1066         return ret;
1067 }
1068
1069 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1070 {
1071         int cpu;
1072         struct acpi_processor *_pr;
1073         struct cpuidle_device *dev;
1074
1075         if (disabled_by_idle_boot_param())
1076                 return 0;
1077
1078         if (nocst)
1079                 return -ENODEV;
1080
1081         if (!pr->flags.power_setup_done)
1082                 return -ENODEV;
1083
1084         /*
1085          * FIXME:  Design the ACPI notification to make it once per
1086          * system instead of once per-cpu.  This condition is a hack
1087          * to make the code that updates C-States be called once.
1088          */
1089
1090         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1091
1092                 cpuidle_pause_and_lock();
1093                 /* Protect against cpu-hotplug */
1094                 get_online_cpus();
1095
1096                 /* Disable all cpuidle devices */
1097                 for_each_online_cpu(cpu) {
1098                         _pr = per_cpu(processors, cpu);
1099                         if (!_pr || !_pr->flags.power_setup_done)
1100                                 continue;
1101                         dev = per_cpu(acpi_cpuidle_device, cpu);
1102                         cpuidle_disable_device(dev);
1103                 }
1104
1105                 /* Populate Updated C-state information */
1106                 acpi_processor_get_power_info(pr);
1107                 acpi_processor_setup_cpuidle_states(pr);
1108
1109                 /* Enable all cpuidle devices */
1110                 for_each_online_cpu(cpu) {
1111                         _pr = per_cpu(processors, cpu);
1112                         if (!_pr || !_pr->flags.power_setup_done)
1113                                 continue;
1114                         acpi_processor_get_power_info(_pr);
1115                         if (_pr->flags.power) {
1116                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1117                                 acpi_processor_setup_cpuidle_cx(_pr, dev);
1118                                 cpuidle_enable_device(dev);
1119                         }
1120                 }
1121                 put_online_cpus();
1122                 cpuidle_resume_and_unlock();
1123         }
1124
1125         return 0;
1126 }
1127
1128 static int acpi_processor_registered;
1129
1130 int acpi_processor_power_init(struct acpi_processor *pr)
1131 {
1132         acpi_status status = 0;
1133         int retval;
1134         struct cpuidle_device *dev;
1135         static int first_run;
1136
1137         if (disabled_by_idle_boot_param())
1138                 return 0;
1139
1140         if (!first_run) {
1141                 dmi_check_system(processor_power_dmi_table);
1142                 max_cstate = acpi_processor_cstate_check(max_cstate);
1143                 if (max_cstate < ACPI_C_STATES_MAX)
1144                         printk(KERN_NOTICE
1145                                "ACPI: processor limited to max C-state %d\n",
1146                                max_cstate);
1147                 first_run++;
1148         }
1149
1150         if (acpi_gbl_FADT.cst_control && !nocst) {
1151                 status =
1152                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1153                 if (ACPI_FAILURE(status)) {
1154                         ACPI_EXCEPTION((AE_INFO, status,
1155                                         "Notifying BIOS of _CST ability failed"));
1156                 }
1157         }
1158
1159         acpi_processor_get_power_info(pr);
1160         pr->flags.power_setup_done = 1;
1161
1162         /*
1163          * Install the idle handler if processor power management is supported.
1164          * Note that we use previously set idle handler will be used on
1165          * platforms that only support C1.
1166          */
1167         if (pr->flags.power) {
1168                 /* Register acpi_idle_driver if not already registered */
1169                 if (!acpi_processor_registered) {
1170                         acpi_processor_setup_cpuidle_states(pr);
1171                         retval = cpuidle_register_driver(&acpi_idle_driver);
1172                         if (retval)
1173                                 return retval;
1174                         printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1175                                         acpi_idle_driver.name);
1176                 }
1177
1178                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1179                 if (!dev)
1180                         return -ENOMEM;
1181                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1182
1183                 acpi_processor_setup_cpuidle_cx(pr, dev);
1184
1185                 /* Register per-cpu cpuidle_device. Cpuidle driver
1186                  * must already be registered before registering device
1187                  */
1188                 retval = cpuidle_register_device(dev);
1189                 if (retval) {
1190                         if (acpi_processor_registered == 0)
1191                                 cpuidle_unregister_driver(&acpi_idle_driver);
1192                         return retval;
1193                 }
1194                 acpi_processor_registered++;
1195         }
1196         return 0;
1197 }
1198
1199 int acpi_processor_power_exit(struct acpi_processor *pr)
1200 {
1201         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1202
1203         if (disabled_by_idle_boot_param())
1204                 return 0;
1205
1206         if (pr->flags.power) {
1207                 cpuidle_unregister_device(dev);
1208                 acpi_processor_registered--;
1209                 if (acpi_processor_registered == 0)
1210                         cpuidle_unregister_driver(&acpi_idle_driver);
1211         }
1212
1213         pr->flags.power_setup_done = 0;
1214         return 0;
1215 }