Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[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 US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
68 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
69 #define C2_OVERHEAD                     1       /* 1us */
70 #define C3_OVERHEAD                     1       /* 1us */
71 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
72
73 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
74 module_param(max_cstate, uint, 0000);
75 static unsigned int nocst __read_mostly;
76 module_param(nocst, uint, 0000);
77
78 static unsigned int latency_factor __read_mostly = 2;
79 module_param(latency_factor, uint, 0644);
80
81 /*
82  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
83  * For now disable this. Probably a bug somewhere else.
84  *
85  * To skip this limit, boot/load with a large max_cstate limit.
86  */
87 static int set_max_cstate(const struct dmi_system_id *id)
88 {
89         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
90                 return 0;
91
92         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
93                " Override with \"processor.max_cstate=%d\"\n", id->ident,
94                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
95
96         max_cstate = (long)id->driver_data;
97
98         return 0;
99 }
100
101 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
102    callers to only run once -AK */
103 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
104         { set_max_cstate, "IBM ThinkPad R40e", {
105           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
106           DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
107         { set_max_cstate, "IBM ThinkPad R40e", {
108           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
109           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
110         { set_max_cstate, "IBM ThinkPad R40e", {
111           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
112           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
113         { set_max_cstate, "IBM ThinkPad R40e", {
114           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
115           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
116         { set_max_cstate, "IBM ThinkPad R40e", {
117           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
118           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
119         { set_max_cstate, "IBM ThinkPad R40e", {
120           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
121           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
122         { set_max_cstate, "IBM ThinkPad R40e", {
123           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
124           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
125         { set_max_cstate, "IBM ThinkPad R40e", {
126           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
127           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
128         { set_max_cstate, "IBM ThinkPad R40e", {
129           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
130           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
131         { set_max_cstate, "IBM ThinkPad R40e", {
132           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
133           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
134         { set_max_cstate, "IBM ThinkPad R40e", {
135           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
136           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
137         { set_max_cstate, "IBM ThinkPad R40e", {
138           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
139           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
140         { set_max_cstate, "IBM ThinkPad R40e", {
141           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
142           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
143         { set_max_cstate, "IBM ThinkPad R40e", {
144           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
145           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
146         { set_max_cstate, "IBM ThinkPad R40e", {
147           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
148           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
149         { set_max_cstate, "IBM ThinkPad R40e", {
150           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
151           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
152         { set_max_cstate, "Medion 41700", {
153           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
154           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
155         { set_max_cstate, "Clevo 5600D", {
156           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
157           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
158          (void *)2},
159         {},
160 };
161
162 static inline u32 ticks_elapsed(u32 t1, u32 t2)
163 {
164         if (t2 >= t1)
165                 return (t2 - t1);
166         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
167                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
168         else
169                 return ((0xFFFFFFFF - t1) + t2);
170 }
171
172 static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
173 {
174         if (t2 >= t1)
175                 return PM_TIMER_TICKS_TO_US(t2 - t1);
176         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
177                 return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
178         else
179                 return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
180 }
181
182 /*
183  * Callers should disable interrupts before the call and enable
184  * interrupts after return.
185  */
186 static void acpi_safe_halt(void)
187 {
188         current_thread_info()->status &= ~TS_POLLING;
189         /*
190          * TS_POLLING-cleared state must be visible before we
191          * test NEED_RESCHED:
192          */
193         smp_mb();
194         if (!need_resched()) {
195                 safe_halt();
196                 local_irq_disable();
197         }
198         current_thread_info()->status |= TS_POLLING;
199 }
200
201 #ifdef ARCH_APICTIMER_STOPS_ON_C3
202
203 /*
204  * Some BIOS implementations switch to C3 in the published C2 state.
205  * This seems to be a common problem on AMD boxen, but other vendors
206  * are affected too. We pick the most conservative approach: we assume
207  * that the local APIC stops in both C2 and C3.
208  */
209 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
210                                    struct acpi_processor_cx *cx)
211 {
212         struct acpi_processor_power *pwr = &pr->power;
213         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
214
215         /*
216          * Check, if one of the previous states already marked the lapic
217          * unstable
218          */
219         if (pwr->timer_broadcast_on_state < state)
220                 return;
221
222         if (cx->type >= type)
223                 pr->power.timer_broadcast_on_state = state;
224 }
225
226 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
227 {
228         unsigned long reason;
229
230         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
231                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
232
233         clockevents_notify(reason, &pr->id);
234 }
235
236 /* Power(C) State timer broadcast control */
237 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
238                                        struct acpi_processor_cx *cx,
239                                        int broadcast)
240 {
241         int state = cx - pr->power.states;
242
243         if (state >= pr->power.timer_broadcast_on_state) {
244                 unsigned long reason;
245
246                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
247                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
248                 clockevents_notify(reason, &pr->id);
249         }
250 }
251
252 #else
253
254 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
255                                    struct acpi_processor_cx *cstate) { }
256 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
257 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
258                                        struct acpi_processor_cx *cx,
259                                        int broadcast)
260 {
261 }
262
263 #endif
264
265 /*
266  * Suspend / resume control
267  */
268 static int acpi_idle_suspend;
269
270 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
271 {
272         acpi_idle_suspend = 1;
273         return 0;
274 }
275
276 int acpi_processor_resume(struct acpi_device * device)
277 {
278         acpi_idle_suspend = 0;
279         return 0;
280 }
281
282 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
283 static int tsc_halts_in_c(int state)
284 {
285         switch (boot_cpu_data.x86_vendor) {
286         case X86_VENDOR_AMD:
287         case X86_VENDOR_INTEL:
288                 /*
289                  * AMD Fam10h TSC will tick in all
290                  * C/P/S0/S1 states when this bit is set.
291                  */
292                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
293                         return 0;
294
295                 /*FALL THROUGH*/
296         default:
297                 return state > ACPI_STATE_C1;
298         }
299 }
300 #endif
301
302 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
303 {
304
305         if (!pr)
306                 return -EINVAL;
307
308         if (!pr->pblk)
309                 return -ENODEV;
310
311         /* if info is obtained from pblk/fadt, type equals state */
312         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
313         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
314
315 #ifndef CONFIG_HOTPLUG_CPU
316         /*
317          * Check for P_LVL2_UP flag before entering C2 and above on
318          * an SMP system.
319          */
320         if ((num_online_cpus() > 1) &&
321             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
322                 return -ENODEV;
323 #endif
324
325         /* determine C2 and C3 address from pblk */
326         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
327         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
328
329         /* determine latencies from FADT */
330         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
331         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
332
333         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
334                           "lvl2[0x%08x] lvl3[0x%08x]\n",
335                           pr->power.states[ACPI_STATE_C2].address,
336                           pr->power.states[ACPI_STATE_C3].address));
337
338         return 0;
339 }
340
341 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
342 {
343         if (!pr->power.states[ACPI_STATE_C1].valid) {
344                 /* set the first C-State to C1 */
345                 /* all processors need to support C1 */
346                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
347                 pr->power.states[ACPI_STATE_C1].valid = 1;
348                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
349         }
350         /* the C0 state only exists as a filler in our array */
351         pr->power.states[ACPI_STATE_C0].valid = 1;
352         return 0;
353 }
354
355 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
356 {
357         acpi_status status = 0;
358         acpi_integer count;
359         int current_count;
360         int i;
361         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
362         union acpi_object *cst;
363
364
365         if (nocst)
366                 return -ENODEV;
367
368         current_count = 0;
369
370         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
371         if (ACPI_FAILURE(status)) {
372                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
373                 return -ENODEV;
374         }
375
376         cst = buffer.pointer;
377
378         /* There must be at least 2 elements */
379         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
380                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
381                 status = -EFAULT;
382                 goto end;
383         }
384
385         count = cst->package.elements[0].integer.value;
386
387         /* Validate number of power states. */
388         if (count < 1 || count != cst->package.count - 1) {
389                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
390                 status = -EFAULT;
391                 goto end;
392         }
393
394         /* Tell driver that at least _CST is supported. */
395         pr->flags.has_cst = 1;
396
397         for (i = 1; i <= count; i++) {
398                 union acpi_object *element;
399                 union acpi_object *obj;
400                 struct acpi_power_register *reg;
401                 struct acpi_processor_cx cx;
402
403                 memset(&cx, 0, sizeof(cx));
404
405                 element = &(cst->package.elements[i]);
406                 if (element->type != ACPI_TYPE_PACKAGE)
407                         continue;
408
409                 if (element->package.count != 4)
410                         continue;
411
412                 obj = &(element->package.elements[0]);
413
414                 if (obj->type != ACPI_TYPE_BUFFER)
415                         continue;
416
417                 reg = (struct acpi_power_register *)obj->buffer.pointer;
418
419                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
420                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
421                         continue;
422
423                 /* There should be an easy way to extract an integer... */
424                 obj = &(element->package.elements[1]);
425                 if (obj->type != ACPI_TYPE_INTEGER)
426                         continue;
427
428                 cx.type = obj->integer.value;
429                 /*
430                  * Some buggy BIOSes won't list C1 in _CST -
431                  * Let acpi_processor_get_power_info_default() handle them later
432                  */
433                 if (i == 1 && cx.type != ACPI_STATE_C1)
434                         current_count++;
435
436                 cx.address = reg->address;
437                 cx.index = current_count + 1;
438
439                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
440                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
441                         if (acpi_processor_ffh_cstate_probe
442                                         (pr->id, &cx, reg) == 0) {
443                                 cx.entry_method = ACPI_CSTATE_FFH;
444                         } else if (cx.type == ACPI_STATE_C1) {
445                                 /*
446                                  * C1 is a special case where FIXED_HARDWARE
447                                  * can be handled in non-MWAIT way as well.
448                                  * In that case, save this _CST entry info.
449                                  * Otherwise, ignore this info and continue.
450                                  */
451                                 cx.entry_method = ACPI_CSTATE_HALT;
452                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
453                         } else {
454                                 continue;
455                         }
456                         if (cx.type == ACPI_STATE_C1 &&
457                                         (idle_halt || idle_nomwait)) {
458                                 /*
459                                  * In most cases the C1 space_id obtained from
460                                  * _CST object is FIXED_HARDWARE access mode.
461                                  * But when the option of idle=halt is added,
462                                  * the entry_method type should be changed from
463                                  * CSTATE_FFH to CSTATE_HALT.
464                                  * When the option of idle=nomwait is added,
465                                  * the C1 entry_method type should be
466                                  * CSTATE_HALT.
467                                  */
468                                 cx.entry_method = ACPI_CSTATE_HALT;
469                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
470                         }
471                 } else {
472                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
473                                  cx.address);
474                 }
475
476                 if (cx.type == ACPI_STATE_C1) {
477                         cx.valid = 1;
478                 }
479
480                 obj = &(element->package.elements[2]);
481                 if (obj->type != ACPI_TYPE_INTEGER)
482                         continue;
483
484                 cx.latency = obj->integer.value;
485
486                 obj = &(element->package.elements[3]);
487                 if (obj->type != ACPI_TYPE_INTEGER)
488                         continue;
489
490                 cx.power = obj->integer.value;
491
492                 current_count++;
493                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
494
495                 /*
496                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
497                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
498                  */
499                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
500                         printk(KERN_WARNING
501                                "Limiting number of power states to max (%d)\n",
502                                ACPI_PROCESSOR_MAX_POWER);
503                         printk(KERN_WARNING
504                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
505                         break;
506                 }
507         }
508
509         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
510                           current_count));
511
512         /* Validate number of power states discovered */
513         if (current_count < 2)
514                 status = -EFAULT;
515
516       end:
517         kfree(buffer.pointer);
518
519         return status;
520 }
521
522 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
523 {
524
525         if (!cx->address)
526                 return;
527
528         /*
529          * C2 latency must be less than or equal to 100
530          * microseconds.
531          */
532         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
533                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
534                                   "latency too large [%d]\n", cx->latency));
535                 return;
536         }
537
538         /*
539          * Otherwise we've met all of our C2 requirements.
540          * Normalize the C2 latency to expidite policy
541          */
542         cx->valid = 1;
543
544         cx->latency_ticks = cx->latency;
545
546         return;
547 }
548
549 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
550                                            struct acpi_processor_cx *cx)
551 {
552         static int bm_check_flag;
553
554
555         if (!cx->address)
556                 return;
557
558         /*
559          * C3 latency must be less than or equal to 1000
560          * microseconds.
561          */
562         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
563                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
564                                   "latency too large [%d]\n", cx->latency));
565                 return;
566         }
567
568         /*
569          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
570          * DMA transfers are used by any ISA device to avoid livelock.
571          * Note that we could disable Type-F DMA (as recommended by
572          * the erratum), but this is known to disrupt certain ISA
573          * devices thus we take the conservative approach.
574          */
575         else if (errata.piix4.fdma) {
576                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
577                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
578                 return;
579         }
580
581         /* All the logic here assumes flags.bm_check is same across all CPUs */
582         if (!bm_check_flag) {
583                 /* Determine whether bm_check is needed based on CPU  */
584                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
585                 bm_check_flag = pr->flags.bm_check;
586         } else {
587                 pr->flags.bm_check = bm_check_flag;
588         }
589
590         if (pr->flags.bm_check) {
591                 if (!pr->flags.bm_control) {
592                         if (pr->flags.has_cst != 1) {
593                                 /* bus mastering control is necessary */
594                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
595                                         "C3 support requires BM control\n"));
596                                 return;
597                         } else {
598                                 /* Here we enter C3 without bus mastering */
599                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
600                                         "C3 support without BM control\n"));
601                         }
602                 }
603         } else {
604                 /*
605                  * WBINVD should be set in fadt, for C3 state to be
606                  * supported on when bm_check is not required.
607                  */
608                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
609                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
610                                           "Cache invalidation should work properly"
611                                           " for C3 to be enabled on SMP systems\n"));
612                         return;
613                 }
614         }
615
616         /*
617          * Otherwise we've met all of our C3 requirements.
618          * Normalize the C3 latency to expidite policy.  Enable
619          * checking of bus mastering status (bm_check) so we can
620          * use this in our C3 policy
621          */
622         cx->valid = 1;
623
624         cx->latency_ticks = cx->latency;
625         /*
626          * On older chipsets, BM_RLD needs to be set
627          * in order for Bus Master activity to wake the
628          * system from C3.  Newer chipsets handle DMA
629          * during C3 automatically and BM_RLD is a NOP.
630          * In either case, the proper way to
631          * handle BM_RLD is to set it and leave it set.
632          */
633         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
634
635         return;
636 }
637
638 static int acpi_processor_power_verify(struct acpi_processor *pr)
639 {
640         unsigned int i;
641         unsigned int working = 0;
642
643         pr->power.timer_broadcast_on_state = INT_MAX;
644
645         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
646                 struct acpi_processor_cx *cx = &pr->power.states[i];
647
648                 switch (cx->type) {
649                 case ACPI_STATE_C1:
650                         cx->valid = 1;
651                         break;
652
653                 case ACPI_STATE_C2:
654                         acpi_processor_power_verify_c2(cx);
655                         if (cx->valid)
656                                 acpi_timer_check_state(i, pr, cx);
657                         break;
658
659                 case ACPI_STATE_C3:
660                         acpi_processor_power_verify_c3(pr, cx);
661                         if (cx->valid)
662                                 acpi_timer_check_state(i, pr, cx);
663                         break;
664                 }
665
666                 if (cx->valid)
667                         working++;
668         }
669
670         acpi_propagate_timer_broadcast(pr);
671
672         return (working);
673 }
674
675 static int acpi_processor_get_power_info(struct acpi_processor *pr)
676 {
677         unsigned int i;
678         int result;
679
680
681         /* NOTE: the idle thread may not be running while calling
682          * this function */
683
684         /* Zero initialize all the C-states info. */
685         memset(pr->power.states, 0, sizeof(pr->power.states));
686
687         result = acpi_processor_get_power_info_cst(pr);
688         if (result == -ENODEV)
689                 result = acpi_processor_get_power_info_fadt(pr);
690
691         if (result)
692                 return result;
693
694         acpi_processor_get_power_info_default(pr);
695
696         pr->power.count = acpi_processor_power_verify(pr);
697
698         /*
699          * if one state of type C2 or C3 is available, mark this
700          * CPU as being "idle manageable"
701          */
702         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
703                 if (pr->power.states[i].valid) {
704                         pr->power.count = i;
705                         if (pr->power.states[i].type >= ACPI_STATE_C2)
706                                 pr->flags.power = 1;
707                 }
708         }
709
710         return 0;
711 }
712
713 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
714 {
715         struct acpi_processor *pr = seq->private;
716         unsigned int i;
717
718
719         if (!pr)
720                 goto end;
721
722         seq_printf(seq, "active state:            C%zd\n"
723                    "max_cstate:              C%d\n"
724                    "bus master activity:     %08x\n"
725                    "maximum allowed latency: %d usec\n",
726                    pr->power.state ? pr->power.state - pr->power.states : 0,
727                    max_cstate, (unsigned)pr->power.bm_activity,
728                    pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
729
730         seq_puts(seq, "states:\n");
731
732         for (i = 1; i <= pr->power.count; i++) {
733                 seq_printf(seq, "   %cC%d:                  ",
734                            (&pr->power.states[i] ==
735                             pr->power.state ? '*' : ' '), i);
736
737                 if (!pr->power.states[i].valid) {
738                         seq_puts(seq, "<not supported>\n");
739                         continue;
740                 }
741
742                 switch (pr->power.states[i].type) {
743                 case ACPI_STATE_C1:
744                         seq_printf(seq, "type[C1] ");
745                         break;
746                 case ACPI_STATE_C2:
747                         seq_printf(seq, "type[C2] ");
748                         break;
749                 case ACPI_STATE_C3:
750                         seq_printf(seq, "type[C3] ");
751                         break;
752                 default:
753                         seq_printf(seq, "type[--] ");
754                         break;
755                 }
756
757                 if (pr->power.states[i].promotion.state)
758                         seq_printf(seq, "promotion[C%zd] ",
759                                    (pr->power.states[i].promotion.state -
760                                     pr->power.states));
761                 else
762                         seq_puts(seq, "promotion[--] ");
763
764                 if (pr->power.states[i].demotion.state)
765                         seq_printf(seq, "demotion[C%zd] ",
766                                    (pr->power.states[i].demotion.state -
767                                     pr->power.states));
768                 else
769                         seq_puts(seq, "demotion[--] ");
770
771                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
772                            pr->power.states[i].latency,
773                            pr->power.states[i].usage,
774                            (unsigned long long)pr->power.states[i].time);
775         }
776
777       end:
778         return 0;
779 }
780
781 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
782 {
783         return single_open(file, acpi_processor_power_seq_show,
784                            PDE(inode)->data);
785 }
786
787 static const struct file_operations acpi_processor_power_fops = {
788         .owner = THIS_MODULE,
789         .open = acpi_processor_power_open_fs,
790         .read = seq_read,
791         .llseek = seq_lseek,
792         .release = single_release,
793 };
794
795
796 /**
797  * acpi_idle_bm_check - checks if bus master activity was detected
798  */
799 static int acpi_idle_bm_check(void)
800 {
801         u32 bm_status = 0;
802
803         acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
804         if (bm_status)
805                 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
806         /*
807          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
808          * the true state of bus mastering activity; forcing us to
809          * manually check the BMIDEA bit of each IDE channel.
810          */
811         else if (errata.piix4.bmisx) {
812                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
813                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
814                         bm_status = 1;
815         }
816         return bm_status;
817 }
818
819 /**
820  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
821  * @cx: cstate data
822  *
823  * Caller disables interrupt before call and enables interrupt after return.
824  */
825 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
826 {
827         /* Don't trace irqs off for idle */
828         stop_critical_timings();
829         if (cx->entry_method == ACPI_CSTATE_FFH) {
830                 /* Call into architectural FFH based C-state */
831                 acpi_processor_ffh_cstate_enter(cx);
832         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
833                 acpi_safe_halt();
834         } else {
835                 int unused;
836                 /* IO port based C-state */
837                 inb(cx->address);
838                 /* Dummy wait op - must do something useless after P_LVL2 read
839                    because chipsets cannot guarantee that STPCLK# signal
840                    gets asserted in time to freeze execution properly. */
841                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
842         }
843         start_critical_timings();
844 }
845
846 /**
847  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
848  * @dev: the target CPU
849  * @state: the state data
850  *
851  * This is equivalent to the HALT instruction.
852  */
853 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
854                               struct cpuidle_state *state)
855 {
856         u32 t1, t2;
857         struct acpi_processor *pr;
858         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
859
860         pr = __get_cpu_var(processors);
861
862         if (unlikely(!pr))
863                 return 0;
864
865         local_irq_disable();
866
867         /* Do not access any ACPI IO ports in suspend path */
868         if (acpi_idle_suspend) {
869                 acpi_safe_halt();
870                 local_irq_enable();
871                 return 0;
872         }
873
874         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
875         acpi_idle_do_entry(cx);
876         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
877
878         local_irq_enable();
879         cx->usage++;
880
881         return ticks_elapsed_in_us(t1, t2);
882 }
883
884 /**
885  * acpi_idle_enter_simple - enters an ACPI state without BM handling
886  * @dev: the target CPU
887  * @state: the state data
888  */
889 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
890                                   struct cpuidle_state *state)
891 {
892         struct acpi_processor *pr;
893         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
894         u32 t1, t2;
895         int sleep_ticks = 0;
896
897         pr = __get_cpu_var(processors);
898
899         if (unlikely(!pr))
900                 return 0;
901
902         if (acpi_idle_suspend)
903                 return(acpi_idle_enter_c1(dev, state));
904
905         local_irq_disable();
906         current_thread_info()->status &= ~TS_POLLING;
907         /*
908          * TS_POLLING-cleared state must be visible before we test
909          * NEED_RESCHED:
910          */
911         smp_mb();
912
913         if (unlikely(need_resched())) {
914                 current_thread_info()->status |= TS_POLLING;
915                 local_irq_enable();
916                 return 0;
917         }
918
919         /*
920          * Must be done before busmaster disable as we might need to
921          * access HPET !
922          */
923         acpi_state_timer_broadcast(pr, cx, 1);
924
925         if (cx->type == ACPI_STATE_C3)
926                 ACPI_FLUSH_CPU_CACHE();
927
928         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
929         /* Tell the scheduler that we are going deep-idle: */
930         sched_clock_idle_sleep_event();
931         acpi_idle_do_entry(cx);
932         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
933
934 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
935         /* TSC could halt in idle, so notify users */
936         if (tsc_halts_in_c(cx->type))
937                 mark_tsc_unstable("TSC halts in idle");;
938 #endif
939         sleep_ticks = ticks_elapsed(t1, t2);
940
941         /* Tell the scheduler how much we idled: */
942         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
943
944         local_irq_enable();
945         current_thread_info()->status |= TS_POLLING;
946
947         cx->usage++;
948
949         acpi_state_timer_broadcast(pr, cx, 0);
950         cx->time += sleep_ticks;
951         return ticks_elapsed_in_us(t1, t2);
952 }
953
954 static int c3_cpu_count;
955 static DEFINE_SPINLOCK(c3_lock);
956
957 /**
958  * acpi_idle_enter_bm - enters C3 with proper BM handling
959  * @dev: the target CPU
960  * @state: the state data
961  *
962  * If BM is detected, the deepest non-C3 idle state is entered instead.
963  */
964 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
965                               struct cpuidle_state *state)
966 {
967         struct acpi_processor *pr;
968         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
969         u32 t1, t2;
970         int sleep_ticks = 0;
971
972         pr = __get_cpu_var(processors);
973
974         if (unlikely(!pr))
975                 return 0;
976
977         if (acpi_idle_suspend)
978                 return(acpi_idle_enter_c1(dev, state));
979
980         if (acpi_idle_bm_check()) {
981                 if (dev->safe_state) {
982                         dev->last_state = dev->safe_state;
983                         return dev->safe_state->enter(dev, dev->safe_state);
984                 } else {
985                         local_irq_disable();
986                         acpi_safe_halt();
987                         local_irq_enable();
988                         return 0;
989                 }
990         }
991
992         local_irq_disable();
993         current_thread_info()->status &= ~TS_POLLING;
994         /*
995          * TS_POLLING-cleared state must be visible before we test
996          * NEED_RESCHED:
997          */
998         smp_mb();
999
1000         if (unlikely(need_resched())) {
1001                 current_thread_info()->status |= TS_POLLING;
1002                 local_irq_enable();
1003                 return 0;
1004         }
1005
1006         acpi_unlazy_tlb(smp_processor_id());
1007
1008         /* Tell the scheduler that we are going deep-idle: */
1009         sched_clock_idle_sleep_event();
1010         /*
1011          * Must be done before busmaster disable as we might need to
1012          * access HPET !
1013          */
1014         acpi_state_timer_broadcast(pr, cx, 1);
1015
1016         /*
1017          * disable bus master
1018          * bm_check implies we need ARB_DIS
1019          * !bm_check implies we need cache flush
1020          * bm_control implies whether we can do ARB_DIS
1021          *
1022          * That leaves a case where bm_check is set and bm_control is
1023          * not set. In that case we cannot do much, we enter C3
1024          * without doing anything.
1025          */
1026         if (pr->flags.bm_check && pr->flags.bm_control) {
1027                 spin_lock(&c3_lock);
1028                 c3_cpu_count++;
1029                 /* Disable bus master arbitration when all CPUs are in C3 */
1030                 if (c3_cpu_count == num_online_cpus())
1031                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
1032                 spin_unlock(&c3_lock);
1033         } else if (!pr->flags.bm_check) {
1034                 ACPI_FLUSH_CPU_CACHE();
1035         }
1036
1037         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1038         acpi_idle_do_entry(cx);
1039         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1040
1041         /* Re-enable bus master arbitration */
1042         if (pr->flags.bm_check && pr->flags.bm_control) {
1043                 spin_lock(&c3_lock);
1044                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
1045                 c3_cpu_count--;
1046                 spin_unlock(&c3_lock);
1047         }
1048
1049 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
1050         /* TSC could halt in idle, so notify users */
1051         if (tsc_halts_in_c(ACPI_STATE_C3))
1052                 mark_tsc_unstable("TSC halts in idle");
1053 #endif
1054         sleep_ticks = ticks_elapsed(t1, t2);
1055         /* Tell the scheduler how much we idled: */
1056         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1057
1058         local_irq_enable();
1059         current_thread_info()->status |= TS_POLLING;
1060
1061         cx->usage++;
1062
1063         acpi_state_timer_broadcast(pr, cx, 0);
1064         cx->time += sleep_ticks;
1065         return ticks_elapsed_in_us(t1, t2);
1066 }
1067
1068 struct cpuidle_driver acpi_idle_driver = {
1069         .name =         "acpi_idle",
1070         .owner =        THIS_MODULE,
1071 };
1072
1073 /**
1074  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1075  * @pr: the ACPI processor
1076  */
1077 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1078 {
1079         int i, count = CPUIDLE_DRIVER_STATE_START;
1080         struct acpi_processor_cx *cx;
1081         struct cpuidle_state *state;
1082         struct cpuidle_device *dev = &pr->power.dev;
1083
1084         if (!pr->flags.power_setup_done)
1085                 return -EINVAL;
1086
1087         if (pr->flags.power == 0) {
1088                 return -EINVAL;
1089         }
1090
1091         dev->cpu = pr->id;
1092         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1093                 dev->states[i].name[0] = '\0';
1094                 dev->states[i].desc[0] = '\0';
1095         }
1096
1097         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1098                 cx = &pr->power.states[i];
1099                 state = &dev->states[count];
1100
1101                 if (!cx->valid)
1102                         continue;
1103
1104 #ifdef CONFIG_HOTPLUG_CPU
1105                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1106                     !pr->flags.has_cst &&
1107                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1108                         continue;
1109 #endif
1110                 cpuidle_set_statedata(state, cx);
1111
1112                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1113                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1114                 state->exit_latency = cx->latency;
1115                 state->target_residency = cx->latency * latency_factor;
1116                 state->power_usage = cx->power;
1117
1118                 state->flags = 0;
1119                 switch (cx->type) {
1120                         case ACPI_STATE_C1:
1121                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1122                         if (cx->entry_method == ACPI_CSTATE_FFH)
1123                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1124
1125                         state->enter = acpi_idle_enter_c1;
1126                         dev->safe_state = state;
1127                         break;
1128
1129                         case ACPI_STATE_C2:
1130                         state->flags |= CPUIDLE_FLAG_BALANCED;
1131                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1132                         state->enter = acpi_idle_enter_simple;
1133                         dev->safe_state = state;
1134                         break;
1135
1136                         case ACPI_STATE_C3:
1137                         state->flags |= CPUIDLE_FLAG_DEEP;
1138                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1139                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1140                         state->enter = pr->flags.bm_check ?
1141                                         acpi_idle_enter_bm :
1142                                         acpi_idle_enter_simple;
1143                         break;
1144                 }
1145
1146                 count++;
1147                 if (count == CPUIDLE_STATE_MAX)
1148                         break;
1149         }
1150
1151         dev->state_count = count;
1152
1153         if (!count)
1154                 return -EINVAL;
1155
1156         return 0;
1157 }
1158
1159 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1160 {
1161         int ret = 0;
1162
1163         if (boot_option_idle_override)
1164                 return 0;
1165
1166         if (!pr)
1167                 return -EINVAL;
1168
1169         if (nocst) {
1170                 return -ENODEV;
1171         }
1172
1173         if (!pr->flags.power_setup_done)
1174                 return -ENODEV;
1175
1176         cpuidle_pause_and_lock();
1177         cpuidle_disable_device(&pr->power.dev);
1178         acpi_processor_get_power_info(pr);
1179         if (pr->flags.power) {
1180                 acpi_processor_setup_cpuidle(pr);
1181                 ret = cpuidle_enable_device(&pr->power.dev);
1182         }
1183         cpuidle_resume_and_unlock();
1184
1185         return ret;
1186 }
1187
1188 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1189                               struct acpi_device *device)
1190 {
1191         acpi_status status = 0;
1192         static int first_run;
1193         struct proc_dir_entry *entry = NULL;
1194         unsigned int i;
1195
1196         if (boot_option_idle_override)
1197                 return 0;
1198
1199         if (!first_run) {
1200                 if (idle_halt) {
1201                         /*
1202                          * When the boot option of "idle=halt" is added, halt
1203                          * is used for CPU IDLE.
1204                          * In such case C2/C3 is meaningless. So the max_cstate
1205                          * is set to one.
1206                          */
1207                         max_cstate = 1;
1208                 }
1209                 dmi_check_system(processor_power_dmi_table);
1210                 max_cstate = acpi_processor_cstate_check(max_cstate);
1211                 if (max_cstate < ACPI_C_STATES_MAX)
1212                         printk(KERN_NOTICE
1213                                "ACPI: processor limited to max C-state %d\n",
1214                                max_cstate);
1215                 first_run++;
1216         }
1217
1218         if (!pr)
1219                 return -EINVAL;
1220
1221         if (acpi_gbl_FADT.cst_control && !nocst) {
1222                 status =
1223                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1224                 if (ACPI_FAILURE(status)) {
1225                         ACPI_EXCEPTION((AE_INFO, status,
1226                                         "Notifying BIOS of _CST ability failed"));
1227                 }
1228         }
1229
1230         acpi_processor_get_power_info(pr);
1231         pr->flags.power_setup_done = 1;
1232
1233         /*
1234          * Install the idle handler if processor power management is supported.
1235          * Note that we use previously set idle handler will be used on
1236          * platforms that only support C1.
1237          */
1238         if (pr->flags.power) {
1239                 acpi_processor_setup_cpuidle(pr);
1240                 if (cpuidle_register_device(&pr->power.dev))
1241                         return -EIO;
1242
1243                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1244                 for (i = 1; i <= pr->power.count; i++)
1245                         if (pr->power.states[i].valid)
1246                                 printk(" C%d[C%d]", i,
1247                                        pr->power.states[i].type);
1248                 printk(")\n");
1249         }
1250
1251         /* 'power' [R] */
1252         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1253                                  S_IRUGO, acpi_device_dir(device),
1254                                  &acpi_processor_power_fops,
1255                                  acpi_driver_data(device));
1256         if (!entry)
1257                 return -EIO;
1258         return 0;
1259 }
1260
1261 int acpi_processor_power_exit(struct acpi_processor *pr,
1262                               struct acpi_device *device)
1263 {
1264         if (boot_option_idle_override)
1265                 return 0;
1266
1267         cpuidle_unregister_device(&pr->power.dev);
1268         pr->flags.power_setup_done = 0;
1269
1270         if (acpi_device_dir(device))
1271                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1272                                   acpi_device_dir(device));
1273
1274         return 0;
1275 }