Merge branch 'acpi-lpss' into acpi-cleanup
[linux-3.10.git] / drivers / acpi / processor_idle.c
1 /*
2  * processor_idle - idle state submodule to the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  *                      - Added support for C3 on SMP
11  *
12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13  *
14  *  This program is free software; you can redistribute it and/or modify
15  *  it under the terms of the GNU General Public License as published by
16  *  the Free Software Foundation; either version 2 of the License, or (at
17  *  your option) any later version.
18  *
19  *  This program is distributed in the hope that it will be useful, but
20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  *  General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License along
25  *  with this program; if not, write to the Free Software Foundation, Inc.,
26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
27  *
28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29  */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/cpufreq.h>
35 #include <linux/slab.h>
36 #include <linux/acpi.h>
37 #include <linux/dmi.h>
38 #include <linux/moduleparam.h>
39 #include <linux/sched.h>        /* need_resched() */
40 #include <linux/pm_qos.h>
41 #include <linux/clockchips.h>
42 #include <linux/cpuidle.h>
43 #include <linux/irqflags.h>
44
45 /*
46  * Include the apic definitions for x86 to have the APIC timer related defines
47  * available also for UP (on SMP it gets magically included via linux/smp.h).
48  * asm/acpi.h is not an option, as it would require more include magic. Also
49  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
50  */
51 #ifdef CONFIG_X86
52 #include <asm/apic.h>
53 #endif
54
55 #include <asm/io.h>
56 #include <asm/uaccess.h>
57
58 #include <acpi/acpi_bus.h>
59 #include <acpi/processor.h>
60 #include <asm/processor.h>
61
62 #define PREFIX "ACPI: "
63
64 #define ACPI_PROCESSOR_CLASS            "processor"
65 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
66 ACPI_MODULE_NAME("processor_idle");
67 #define PM_TIMER_TICK_NS                (1000000000ULL/ACPI_PM_TIMER_FREQUENCY)
68 #define C2_OVERHEAD                     1       /* 1us */
69 #define C3_OVERHEAD                     1       /* 1us */
70 #define PM_TIMER_TICKS_TO_US(p)         \
71         (((p) * 1000)/(ACPI_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 static int bm_check_disable __read_mostly;
78 module_param(bm_check_disable, uint, 0000);
79
80 static unsigned int latency_factor __read_mostly = 2;
81 module_param(latency_factor, uint, 0644);
82
83 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
84
85 static int disabled_by_idle_boot_param(void)
86 {
87         return boot_option_idle_override == IDLE_POLL ||
88                 boot_option_idle_override == IDLE_FORCE_MWAIT ||
89                 boot_option_idle_override == IDLE_HALT;
90 }
91
92 /*
93  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
94  * For now disable this. Probably a bug somewhere else.
95  *
96  * To skip this limit, boot/load with a large max_cstate limit.
97  */
98 static int set_max_cstate(const struct dmi_system_id *id)
99 {
100         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
101                 return 0;
102
103         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
104                " Override with \"processor.max_cstate=%d\"\n", id->ident,
105                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
106
107         max_cstate = (long)id->driver_data;
108
109         return 0;
110 }
111
112 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
113    callers to only run once -AK */
114 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
115         { set_max_cstate, "Clevo 5600D", {
116           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
117           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
118          (void *)2},
119         { set_max_cstate, "Pavilion zv5000", {
120           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
121           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
122          (void *)1},
123         { set_max_cstate, "Asus L8400B", {
124           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
125           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
126          (void *)1},
127         {},
128 };
129
130
131 /*
132  * Callers should disable interrupts before the call and enable
133  * interrupts after return.
134  */
135 static void acpi_safe_halt(void)
136 {
137         current_thread_info()->status &= ~TS_POLLING;
138         /*
139          * TS_POLLING-cleared state must be visible before we
140          * test NEED_RESCHED:
141          */
142         smp_mb();
143         if (!need_resched()) {
144                 safe_halt();
145                 local_irq_disable();
146         }
147         current_thread_info()->status |= TS_POLLING;
148 }
149
150 #ifdef ARCH_APICTIMER_STOPS_ON_C3
151
152 /*
153  * Some BIOS implementations switch to C3 in the published C2 state.
154  * This seems to be a common problem on AMD boxen, but other vendors
155  * are affected too. We pick the most conservative approach: we assume
156  * that the local APIC stops in both C2 and C3.
157  */
158 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
159                                    struct acpi_processor_cx *cx)
160 {
161         struct acpi_processor_power *pwr = &pr->power;
162         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
163
164         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
165                 return;
166
167         if (amd_e400_c1e_detected)
168                 type = ACPI_STATE_C1;
169
170         /*
171          * Check, if one of the previous states already marked the lapic
172          * unstable
173          */
174         if (pwr->timer_broadcast_on_state < state)
175                 return;
176
177         if (cx->type >= type)
178                 pr->power.timer_broadcast_on_state = state;
179 }
180
181 static void __lapic_timer_propagate_broadcast(void *arg)
182 {
183         struct acpi_processor *pr = (struct acpi_processor *) arg;
184         unsigned long reason;
185
186         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
187                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
188
189         clockevents_notify(reason, &pr->id);
190 }
191
192 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
193 {
194         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
195                                  (void *)pr, 1);
196 }
197
198 /* Power(C) State timer broadcast control */
199 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
200                                        struct acpi_processor_cx *cx,
201                                        int broadcast)
202 {
203         int state = cx - pr->power.states;
204
205         if (state >= pr->power.timer_broadcast_on_state) {
206                 unsigned long reason;
207
208                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
209                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
210                 clockevents_notify(reason, &pr->id);
211         }
212 }
213
214 #else
215
216 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
217                                    struct acpi_processor_cx *cstate) { }
218 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
219 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
220                                        struct acpi_processor_cx *cx,
221                                        int broadcast)
222 {
223 }
224
225 #endif
226
227 static u32 saved_bm_rld;
228
229 static void acpi_idle_bm_rld_save(void)
230 {
231         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
232 }
233 static void acpi_idle_bm_rld_restore(void)
234 {
235         u32 resumed_bm_rld;
236
237         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
238
239         if (resumed_bm_rld != saved_bm_rld)
240                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
241 }
242
243 int acpi_processor_suspend(struct device *dev)
244 {
245         acpi_idle_bm_rld_save();
246         return 0;
247 }
248
249 int acpi_processor_resume(struct device *dev)
250 {
251         acpi_idle_bm_rld_restore();
252         return 0;
253 }
254
255 #if defined(CONFIG_X86)
256 static void tsc_check_state(int state)
257 {
258         switch (boot_cpu_data.x86_vendor) {
259         case X86_VENDOR_AMD:
260         case X86_VENDOR_INTEL:
261                 /*
262                  * AMD Fam10h TSC will tick in all
263                  * C/P/S0/S1 states when this bit is set.
264                  */
265                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
266                         return;
267
268                 /*FALL THROUGH*/
269         default:
270                 /* TSC could halt in idle, so notify users */
271                 if (state > ACPI_STATE_C1)
272                         mark_tsc_unstable("TSC halts in idle");
273         }
274 }
275 #else
276 static void tsc_check_state(int state) { return; }
277 #endif
278
279 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
280 {
281
282         if (!pr)
283                 return -EINVAL;
284
285         if (!pr->pblk)
286                 return -ENODEV;
287
288         /* if info is obtained from pblk/fadt, type equals state */
289         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
290         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
291
292 #ifndef CONFIG_HOTPLUG_CPU
293         /*
294          * Check for P_LVL2_UP flag before entering C2 and above on
295          * an SMP system.
296          */
297         if ((num_online_cpus() > 1) &&
298             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
299                 return -ENODEV;
300 #endif
301
302         /* determine C2 and C3 address from pblk */
303         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
304         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
305
306         /* determine latencies from FADT */
307         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
308         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
309
310         /*
311          * FADT specified C2 latency must be less than or equal to
312          * 100 microseconds.
313          */
314         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
315                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
316                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
317                 /* invalidate C2 */
318                 pr->power.states[ACPI_STATE_C2].address = 0;
319         }
320
321         /*
322          * FADT supplied C3 latency must be less than or equal to
323          * 1000 microseconds.
324          */
325         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
326                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
327                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
328                 /* invalidate C3 */
329                 pr->power.states[ACPI_STATE_C3].address = 0;
330         }
331
332         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
333                           "lvl2[0x%08x] lvl3[0x%08x]\n",
334                           pr->power.states[ACPI_STATE_C2].address,
335                           pr->power.states[ACPI_STATE_C3].address));
336
337         return 0;
338 }
339
340 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
341 {
342         if (!pr->power.states[ACPI_STATE_C1].valid) {
343                 /* set the first C-State to C1 */
344                 /* all processors need to support C1 */
345                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
346                 pr->power.states[ACPI_STATE_C1].valid = 1;
347                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
348         }
349         /* the C0 state only exists as a filler in our array */
350         pr->power.states[ACPI_STATE_C0].valid = 1;
351         return 0;
352 }
353
354 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
355 {
356         acpi_status status = 0;
357         u64 count;
358         int current_count;
359         int i;
360         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
361         union acpi_object *cst;
362
363
364         if (nocst)
365                 return -ENODEV;
366
367         current_count = 0;
368
369         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
370         if (ACPI_FAILURE(status)) {
371                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
372                 return -ENODEV;
373         }
374
375         cst = buffer.pointer;
376
377         /* There must be at least 2 elements */
378         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
379                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
380                 status = -EFAULT;
381                 goto end;
382         }
383
384         count = cst->package.elements[0].integer.value;
385
386         /* Validate number of power states. */
387         if (count < 1 || count != cst->package.count - 1) {
388                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
389                 status = -EFAULT;
390                 goto end;
391         }
392
393         /* Tell driver that at least _CST is supported. */
394         pr->flags.has_cst = 1;
395
396         for (i = 1; i <= count; i++) {
397                 union acpi_object *element;
398                 union acpi_object *obj;
399                 struct acpi_power_register *reg;
400                 struct acpi_processor_cx cx;
401
402                 memset(&cx, 0, sizeof(cx));
403
404                 element = &(cst->package.elements[i]);
405                 if (element->type != ACPI_TYPE_PACKAGE)
406                         continue;
407
408                 if (element->package.count != 4)
409                         continue;
410
411                 obj = &(element->package.elements[0]);
412
413                 if (obj->type != ACPI_TYPE_BUFFER)
414                         continue;
415
416                 reg = (struct acpi_power_register *)obj->buffer.pointer;
417
418                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
419                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
420                         continue;
421
422                 /* There should be an easy way to extract an integer... */
423                 obj = &(element->package.elements[1]);
424                 if (obj->type != ACPI_TYPE_INTEGER)
425                         continue;
426
427                 cx.type = obj->integer.value;
428                 /*
429                  * Some buggy BIOSes won't list C1 in _CST -
430                  * Let acpi_processor_get_power_info_default() handle them later
431                  */
432                 if (i == 1 && cx.type != ACPI_STATE_C1)
433                         current_count++;
434
435                 cx.address = reg->address;
436                 cx.index = current_count + 1;
437
438                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
439                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
440                         if (acpi_processor_ffh_cstate_probe
441                                         (pr->id, &cx, reg) == 0) {
442                                 cx.entry_method = ACPI_CSTATE_FFH;
443                         } else if (cx.type == ACPI_STATE_C1) {
444                                 /*
445                                  * C1 is a special case where FIXED_HARDWARE
446                                  * can be handled in non-MWAIT way as well.
447                                  * In that case, save this _CST entry info.
448                                  * Otherwise, ignore this info and continue.
449                                  */
450                                 cx.entry_method = ACPI_CSTATE_HALT;
451                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
452                         } else {
453                                 continue;
454                         }
455                         if (cx.type == ACPI_STATE_C1 &&
456                             (boot_option_idle_override == IDLE_NOMWAIT)) {
457                                 /*
458                                  * In most cases the C1 space_id obtained from
459                                  * _CST object is FIXED_HARDWARE access mode.
460                                  * But when the option of idle=halt is added,
461                                  * the entry_method type should be changed from
462                                  * CSTATE_FFH to CSTATE_HALT.
463                                  * When the option of idle=nomwait is added,
464                                  * the C1 entry_method type should be
465                                  * CSTATE_HALT.
466                                  */
467                                 cx.entry_method = ACPI_CSTATE_HALT;
468                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
469                         }
470                 } else {
471                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
472                                  cx.address);
473                 }
474
475                 if (cx.type == ACPI_STATE_C1) {
476                         cx.valid = 1;
477                 }
478
479                 obj = &(element->package.elements[2]);
480                 if (obj->type != ACPI_TYPE_INTEGER)
481                         continue;
482
483                 cx.latency = obj->integer.value;
484
485                 obj = &(element->package.elements[3]);
486                 if (obj->type != ACPI_TYPE_INTEGER)
487                         continue;
488
489                 current_count++;
490                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
491
492                 /*
493                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
494                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
495                  */
496                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
497                         printk(KERN_WARNING
498                                "Limiting number of power states to max (%d)\n",
499                                ACPI_PROCESSOR_MAX_POWER);
500                         printk(KERN_WARNING
501                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
502                         break;
503                 }
504         }
505
506         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
507                           current_count));
508
509         /* Validate number of power states discovered */
510         if (current_count < 2)
511                 status = -EFAULT;
512
513       end:
514         kfree(buffer.pointer);
515
516         return status;
517 }
518
519 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
520                                            struct acpi_processor_cx *cx)
521 {
522         static int bm_check_flag = -1;
523         static int bm_control_flag = -1;
524
525
526         if (!cx->address)
527                 return;
528
529         /*
530          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
531          * DMA transfers are used by any ISA device to avoid livelock.
532          * Note that we could disable Type-F DMA (as recommended by
533          * the erratum), but this is known to disrupt certain ISA
534          * devices thus we take the conservative approach.
535          */
536         else if (errata.piix4.fdma) {
537                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
538                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
539                 return;
540         }
541
542         /* All the logic here assumes flags.bm_check is same across all CPUs */
543         if (bm_check_flag == -1) {
544                 /* Determine whether bm_check is needed based on CPU  */
545                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
546                 bm_check_flag = pr->flags.bm_check;
547                 bm_control_flag = pr->flags.bm_control;
548         } else {
549                 pr->flags.bm_check = bm_check_flag;
550                 pr->flags.bm_control = bm_control_flag;
551         }
552
553         if (pr->flags.bm_check) {
554                 if (!pr->flags.bm_control) {
555                         if (pr->flags.has_cst != 1) {
556                                 /* bus mastering control is necessary */
557                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
558                                         "C3 support requires BM control\n"));
559                                 return;
560                         } else {
561                                 /* Here we enter C3 without bus mastering */
562                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
563                                         "C3 support without BM control\n"));
564                         }
565                 }
566         } else {
567                 /*
568                  * WBINVD should be set in fadt, for C3 state to be
569                  * supported on when bm_check is not required.
570                  */
571                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
572                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
573                                           "Cache invalidation should work properly"
574                                           " for C3 to be enabled on SMP systems\n"));
575                         return;
576                 }
577         }
578
579         /*
580          * Otherwise we've met all of our C3 requirements.
581          * Normalize the C3 latency to expidite policy.  Enable
582          * checking of bus mastering status (bm_check) so we can
583          * use this in our C3 policy
584          */
585         cx->valid = 1;
586
587         /*
588          * On older chipsets, BM_RLD needs to be set
589          * in order for Bus Master activity to wake the
590          * system from C3.  Newer chipsets handle DMA
591          * during C3 automatically and BM_RLD is a NOP.
592          * In either case, the proper way to
593          * handle BM_RLD is to set it and leave it set.
594          */
595         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
596
597         return;
598 }
599
600 static int acpi_processor_power_verify(struct acpi_processor *pr)
601 {
602         unsigned int i;
603         unsigned int working = 0;
604
605         pr->power.timer_broadcast_on_state = INT_MAX;
606
607         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
608                 struct acpi_processor_cx *cx = &pr->power.states[i];
609
610                 switch (cx->type) {
611                 case ACPI_STATE_C1:
612                         cx->valid = 1;
613                         break;
614
615                 case ACPI_STATE_C2:
616                         if (!cx->address)
617                                 break;
618                         cx->valid = 1; 
619                         break;
620
621                 case ACPI_STATE_C3:
622                         acpi_processor_power_verify_c3(pr, cx);
623                         break;
624                 }
625                 if (!cx->valid)
626                         continue;
627
628                 lapic_timer_check_state(i, pr, cx);
629                 tsc_check_state(cx->type);
630                 working++;
631         }
632
633         lapic_timer_propagate_broadcast(pr);
634
635         return (working);
636 }
637
638 static int acpi_processor_get_power_info(struct acpi_processor *pr)
639 {
640         unsigned int i;
641         int result;
642
643
644         /* NOTE: the idle thread may not be running while calling
645          * this function */
646
647         /* Zero initialize all the C-states info. */
648         memset(pr->power.states, 0, sizeof(pr->power.states));
649
650         result = acpi_processor_get_power_info_cst(pr);
651         if (result == -ENODEV)
652                 result = acpi_processor_get_power_info_fadt(pr);
653
654         if (result)
655                 return result;
656
657         acpi_processor_get_power_info_default(pr);
658
659         pr->power.count = acpi_processor_power_verify(pr);
660
661         /*
662          * if one state of type C2 or C3 is available, mark this
663          * CPU as being "idle manageable"
664          */
665         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
666                 if (pr->power.states[i].valid) {
667                         pr->power.count = i;
668                         if (pr->power.states[i].type >= ACPI_STATE_C2)
669                                 pr->flags.power = 1;
670                 }
671         }
672
673         return 0;
674 }
675
676 /**
677  * acpi_idle_bm_check - checks if bus master activity was detected
678  */
679 static int acpi_idle_bm_check(void)
680 {
681         u32 bm_status = 0;
682
683         if (bm_check_disable)
684                 return 0;
685
686         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
687         if (bm_status)
688                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
689         /*
690          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
691          * the true state of bus mastering activity; forcing us to
692          * manually check the BMIDEA bit of each IDE channel.
693          */
694         else if (errata.piix4.bmisx) {
695                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
696                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
697                         bm_status = 1;
698         }
699         return bm_status;
700 }
701
702 /**
703  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
704  * @cx: cstate data
705  *
706  * Caller disables interrupt before call and enables interrupt after return.
707  */
708 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
709 {
710         /* Don't trace irqs off for idle */
711         stop_critical_timings();
712         if (cx->entry_method == ACPI_CSTATE_FFH) {
713                 /* Call into architectural FFH based C-state */
714                 acpi_processor_ffh_cstate_enter(cx);
715         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
716                 acpi_safe_halt();
717         } else {
718                 /* IO port based C-state */
719                 inb(cx->address);
720                 /* Dummy wait op - must do something useless after P_LVL2 read
721                    because chipsets cannot guarantee that STPCLK# signal
722                    gets asserted in time to freeze execution properly. */
723                 inl(acpi_gbl_FADT.xpm_timer_block.address);
724         }
725         start_critical_timings();
726 }
727
728 /**
729  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
730  * @dev: the target CPU
731  * @drv: cpuidle driver containing cpuidle state info
732  * @index: index of target state
733  *
734  * This is equivalent to the HALT instruction.
735  */
736 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
737                 struct cpuidle_driver *drv, int index)
738 {
739         struct acpi_processor *pr;
740         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
741         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
742
743         pr = __this_cpu_read(processors);
744
745         if (unlikely(!pr))
746                 return -EINVAL;
747
748         lapic_timer_state_broadcast(pr, cx, 1);
749         acpi_idle_do_entry(cx);
750
751         lapic_timer_state_broadcast(pr, cx, 0);
752
753         return index;
754 }
755
756
757 /**
758  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
759  * @dev: the target CPU
760  * @index: the index of suggested state
761  */
762 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
763 {
764         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
765         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
766
767         ACPI_FLUSH_CPU_CACHE();
768
769         while (1) {
770
771                 if (cx->entry_method == ACPI_CSTATE_HALT)
772                         safe_halt();
773                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
774                         inb(cx->address);
775                         /* See comment in acpi_idle_do_entry() */
776                         inl(acpi_gbl_FADT.xpm_timer_block.address);
777                 } else
778                         return -ENODEV;
779         }
780
781         /* Never reached */
782         return 0;
783 }
784
785 /**
786  * acpi_idle_enter_simple - enters an ACPI state without BM handling
787  * @dev: the target CPU
788  * @drv: cpuidle driver with cpuidle state information
789  * @index: the index of suggested state
790  */
791 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
792                 struct cpuidle_driver *drv, int index)
793 {
794         struct acpi_processor *pr;
795         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
796         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
797
798         pr = __this_cpu_read(processors);
799
800         if (unlikely(!pr))
801                 return -EINVAL;
802
803         if (cx->entry_method != ACPI_CSTATE_FFH) {
804                 current_thread_info()->status &= ~TS_POLLING;
805                 /*
806                  * TS_POLLING-cleared state must be visible before we test
807                  * NEED_RESCHED:
808                  */
809                 smp_mb();
810
811                 if (unlikely(need_resched())) {
812                         current_thread_info()->status |= TS_POLLING;
813                         return -EINVAL;
814                 }
815         }
816
817         /*
818          * Must be done before busmaster disable as we might need to
819          * access HPET !
820          */
821         lapic_timer_state_broadcast(pr, cx, 1);
822
823         if (cx->type == ACPI_STATE_C3)
824                 ACPI_FLUSH_CPU_CACHE();
825
826         /* Tell the scheduler that we are going deep-idle: */
827         sched_clock_idle_sleep_event();
828         acpi_idle_do_entry(cx);
829
830         sched_clock_idle_wakeup_event(0);
831
832         if (cx->entry_method != ACPI_CSTATE_FFH)
833                 current_thread_info()->status |= TS_POLLING;
834
835         lapic_timer_state_broadcast(pr, cx, 0);
836         return index;
837 }
838
839 static int c3_cpu_count;
840 static DEFINE_RAW_SPINLOCK(c3_lock);
841
842 /**
843  * acpi_idle_enter_bm - enters C3 with proper BM handling
844  * @dev: the target CPU
845  * @drv: cpuidle driver containing state data
846  * @index: the index of suggested state
847  *
848  * If BM is detected, the deepest non-C3 idle state is entered instead.
849  */
850 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
851                 struct cpuidle_driver *drv, int index)
852 {
853         struct acpi_processor *pr;
854         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
855         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
856
857         pr = __this_cpu_read(processors);
858
859         if (unlikely(!pr))
860                 return -EINVAL;
861
862         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
863                 if (drv->safe_state_index >= 0) {
864                         return drv->states[drv->safe_state_index].enter(dev,
865                                                 drv, drv->safe_state_index);
866                 } else {
867                         acpi_safe_halt();
868                         return -EBUSY;
869                 }
870         }
871
872         if (cx->entry_method != ACPI_CSTATE_FFH) {
873                 current_thread_info()->status &= ~TS_POLLING;
874                 /*
875                  * TS_POLLING-cleared state must be visible before we test
876                  * NEED_RESCHED:
877                  */
878                 smp_mb();
879
880                 if (unlikely(need_resched())) {
881                         current_thread_info()->status |= TS_POLLING;
882                         return -EINVAL;
883                 }
884         }
885
886         acpi_unlazy_tlb(smp_processor_id());
887
888         /* Tell the scheduler that we are going deep-idle: */
889         sched_clock_idle_sleep_event();
890         /*
891          * Must be done before busmaster disable as we might need to
892          * access HPET !
893          */
894         lapic_timer_state_broadcast(pr, cx, 1);
895
896         /*
897          * disable bus master
898          * bm_check implies we need ARB_DIS
899          * !bm_check implies we need cache flush
900          * bm_control implies whether we can do ARB_DIS
901          *
902          * That leaves a case where bm_check is set and bm_control is
903          * not set. In that case we cannot do much, we enter C3
904          * without doing anything.
905          */
906         if (pr->flags.bm_check && pr->flags.bm_control) {
907                 raw_spin_lock(&c3_lock);
908                 c3_cpu_count++;
909                 /* Disable bus master arbitration when all CPUs are in C3 */
910                 if (c3_cpu_count == num_online_cpus())
911                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
912                 raw_spin_unlock(&c3_lock);
913         } else if (!pr->flags.bm_check) {
914                 ACPI_FLUSH_CPU_CACHE();
915         }
916
917         acpi_idle_do_entry(cx);
918
919         /* Re-enable bus master arbitration */
920         if (pr->flags.bm_check && pr->flags.bm_control) {
921                 raw_spin_lock(&c3_lock);
922                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
923                 c3_cpu_count--;
924                 raw_spin_unlock(&c3_lock);
925         }
926
927         sched_clock_idle_wakeup_event(0);
928
929         if (cx->entry_method != ACPI_CSTATE_FFH)
930                 current_thread_info()->status |= TS_POLLING;
931
932         lapic_timer_state_broadcast(pr, cx, 0);
933         return index;
934 }
935
936 struct cpuidle_driver acpi_idle_driver = {
937         .name =         "acpi_idle",
938         .owner =        THIS_MODULE,
939         .en_core_tk_irqen = 1,
940 };
941
942 /**
943  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
944  * device i.e. per-cpu data
945  *
946  * @pr: the ACPI processor
947  */
948 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr)
949 {
950         int i, count = CPUIDLE_DRIVER_STATE_START;
951         struct acpi_processor_cx *cx;
952         struct cpuidle_state_usage *state_usage;
953         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
954
955         if (!pr->flags.power_setup_done)
956                 return -EINVAL;
957
958         if (pr->flags.power == 0) {
959                 return -EINVAL;
960         }
961
962         if (!dev)
963                 return -EINVAL;
964
965         dev->cpu = pr->id;
966
967         if (max_cstate == 0)
968                 max_cstate = 1;
969
970         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
971                 cx = &pr->power.states[i];
972                 state_usage = &dev->states_usage[count];
973
974                 if (!cx->valid)
975                         continue;
976
977 #ifdef CONFIG_HOTPLUG_CPU
978                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
979                     !pr->flags.has_cst &&
980                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
981                         continue;
982 #endif
983
984                 cpuidle_set_statedata(state_usage, cx);
985
986                 count++;
987                 if (count == CPUIDLE_STATE_MAX)
988                         break;
989         }
990
991         dev->state_count = count;
992
993         if (!count)
994                 return -EINVAL;
995
996         return 0;
997 }
998
999 /**
1000  * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
1001  * global state data i.e. idle routines
1002  *
1003  * @pr: the ACPI processor
1004  */
1005 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1006 {
1007         int i, count = CPUIDLE_DRIVER_STATE_START;
1008         struct acpi_processor_cx *cx;
1009         struct cpuidle_state *state;
1010         struct cpuidle_driver *drv = &acpi_idle_driver;
1011
1012         if (!pr->flags.power_setup_done)
1013                 return -EINVAL;
1014
1015         if (pr->flags.power == 0)
1016                 return -EINVAL;
1017
1018         drv->safe_state_index = -1;
1019         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1020                 drv->states[i].name[0] = '\0';
1021                 drv->states[i].desc[0] = '\0';
1022         }
1023
1024         if (max_cstate == 0)
1025                 max_cstate = 1;
1026
1027         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1028                 cx = &pr->power.states[i];
1029
1030                 if (!cx->valid)
1031                         continue;
1032
1033 #ifdef CONFIG_HOTPLUG_CPU
1034                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1035                     !pr->flags.has_cst &&
1036                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1037                         continue;
1038 #endif
1039
1040                 state = &drv->states[count];
1041                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1042                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1043                 state->exit_latency = cx->latency;
1044                 state->target_residency = cx->latency * latency_factor;
1045
1046                 state->flags = 0;
1047                 switch (cx->type) {
1048                         case ACPI_STATE_C1:
1049                         if (cx->entry_method == ACPI_CSTATE_FFH)
1050                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1051
1052                         state->enter = acpi_idle_enter_c1;
1053                         state->enter_dead = acpi_idle_play_dead;
1054                         drv->safe_state_index = count;
1055                         break;
1056
1057                         case ACPI_STATE_C2:
1058                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1059                         state->enter = acpi_idle_enter_simple;
1060                         state->enter_dead = acpi_idle_play_dead;
1061                         drv->safe_state_index = count;
1062                         break;
1063
1064                         case ACPI_STATE_C3:
1065                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1066                         state->enter = pr->flags.bm_check ?
1067                                         acpi_idle_enter_bm :
1068                                         acpi_idle_enter_simple;
1069                         break;
1070                 }
1071
1072                 count++;
1073                 if (count == CPUIDLE_STATE_MAX)
1074                         break;
1075         }
1076
1077         drv->state_count = count;
1078
1079         if (!count)
1080                 return -EINVAL;
1081
1082         return 0;
1083 }
1084
1085 int acpi_processor_hotplug(struct acpi_processor *pr)
1086 {
1087         int ret = 0;
1088         struct cpuidle_device *dev;
1089
1090         if (disabled_by_idle_boot_param())
1091                 return 0;
1092
1093         if (!pr)
1094                 return -EINVAL;
1095
1096         if (nocst) {
1097                 return -ENODEV;
1098         }
1099
1100         if (!pr->flags.power_setup_done)
1101                 return -ENODEV;
1102
1103         dev = per_cpu(acpi_cpuidle_device, pr->id);
1104         cpuidle_pause_and_lock();
1105         cpuidle_disable_device(dev);
1106         acpi_processor_get_power_info(pr);
1107         if (pr->flags.power) {
1108                 acpi_processor_setup_cpuidle_cx(pr);
1109                 ret = cpuidle_enable_device(dev);
1110         }
1111         cpuidle_resume_and_unlock();
1112
1113         return ret;
1114 }
1115
1116 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1117 {
1118         int cpu;
1119         struct acpi_processor *_pr;
1120         struct cpuidle_device *dev;
1121
1122         if (disabled_by_idle_boot_param())
1123                 return 0;
1124
1125         if (!pr)
1126                 return -EINVAL;
1127
1128         if (nocst)
1129                 return -ENODEV;
1130
1131         if (!pr->flags.power_setup_done)
1132                 return -ENODEV;
1133
1134         /*
1135          * FIXME:  Design the ACPI notification to make it once per
1136          * system instead of once per-cpu.  This condition is a hack
1137          * to make the code that updates C-States be called once.
1138          */
1139
1140         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1141
1142                 cpuidle_pause_and_lock();
1143                 /* Protect against cpu-hotplug */
1144                 get_online_cpus();
1145
1146                 /* Disable all cpuidle devices */
1147                 for_each_online_cpu(cpu) {
1148                         _pr = per_cpu(processors, cpu);
1149                         if (!_pr || !_pr->flags.power_setup_done)
1150                                 continue;
1151                         dev = per_cpu(acpi_cpuidle_device, cpu);
1152                         cpuidle_disable_device(dev);
1153                 }
1154
1155                 /* Populate Updated C-state information */
1156                 acpi_processor_get_power_info(pr);
1157                 acpi_processor_setup_cpuidle_states(pr);
1158
1159                 /* Enable all cpuidle devices */
1160                 for_each_online_cpu(cpu) {
1161                         _pr = per_cpu(processors, cpu);
1162                         if (!_pr || !_pr->flags.power_setup_done)
1163                                 continue;
1164                         acpi_processor_get_power_info(_pr);
1165                         if (_pr->flags.power) {
1166                                 acpi_processor_setup_cpuidle_cx(_pr);
1167                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1168                                 cpuidle_enable_device(dev);
1169                         }
1170                 }
1171                 put_online_cpus();
1172                 cpuidle_resume_and_unlock();
1173         }
1174
1175         return 0;
1176 }
1177
1178 static int acpi_processor_registered;
1179
1180 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr)
1181 {
1182         acpi_status status = 0;
1183         int retval;
1184         struct cpuidle_device *dev;
1185         static int first_run;
1186
1187         if (disabled_by_idle_boot_param())
1188                 return 0;
1189
1190         if (!first_run) {
1191                 dmi_check_system(processor_power_dmi_table);
1192                 max_cstate = acpi_processor_cstate_check(max_cstate);
1193                 if (max_cstate < ACPI_C_STATES_MAX)
1194                         printk(KERN_NOTICE
1195                                "ACPI: processor limited to max C-state %d\n",
1196                                max_cstate);
1197                 first_run++;
1198         }
1199
1200         if (!pr)
1201                 return -EINVAL;
1202
1203         if (acpi_gbl_FADT.cst_control && !nocst) {
1204                 status =
1205                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1206                 if (ACPI_FAILURE(status)) {
1207                         ACPI_EXCEPTION((AE_INFO, status,
1208                                         "Notifying BIOS of _CST ability failed"));
1209                 }
1210         }
1211
1212         acpi_processor_get_power_info(pr);
1213         pr->flags.power_setup_done = 1;
1214
1215         /*
1216          * Install the idle handler if processor power management is supported.
1217          * Note that we use previously set idle handler will be used on
1218          * platforms that only support C1.
1219          */
1220         if (pr->flags.power) {
1221                 /* Register acpi_idle_driver if not already registered */
1222                 if (!acpi_processor_registered) {
1223                         acpi_processor_setup_cpuidle_states(pr);
1224                         retval = cpuidle_register_driver(&acpi_idle_driver);
1225                         if (retval)
1226                                 return retval;
1227                         printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1228                                         acpi_idle_driver.name);
1229                 }
1230
1231                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1232                 if (!dev)
1233                         return -ENOMEM;
1234                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1235
1236                 acpi_processor_setup_cpuidle_cx(pr);
1237
1238                 /* Register per-cpu cpuidle_device. Cpuidle driver
1239                  * must already be registered before registering device
1240                  */
1241                 retval = cpuidle_register_device(dev);
1242                 if (retval) {
1243                         if (acpi_processor_registered == 0)
1244                                 cpuidle_unregister_driver(&acpi_idle_driver);
1245                         return retval;
1246                 }
1247                 acpi_processor_registered++;
1248         }
1249         return 0;
1250 }
1251
1252 int acpi_processor_power_exit(struct acpi_processor *pr)
1253 {
1254         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1255
1256         if (disabled_by_idle_boot_param())
1257                 return 0;
1258
1259         if (pr->flags.power) {
1260                 cpuidle_unregister_device(dev);
1261                 acpi_processor_registered--;
1262                 if (acpi_processor_registered == 0)
1263                         cpuidle_unregister_driver(&acpi_idle_driver);
1264         }
1265
1266         pr->flags.power_setup_done = 0;
1267         return 0;
1268 }