summaryrefslogtreecommitdiff
path: root/drivers/acpi/processor_idle.c
blob: e8e2d88692368f5ea4903485aa7ca6a6b783e493 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
/*
 * processor_idle - idle state submodule to the ACPI processor driver
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
 *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
 *  			- Added processor hotplug support
 *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 *  			- Added support for C3 on SMP
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>	/* need_resched() */
#include <linux/pm_qos_params.h>
#include <linux/clockchips.h>
#include <linux/cpuidle.h>

/*
 * Include the apic definitions for x86 to have the APIC timer related defines
 * available also for UP (on SMP it gets magically included via linux/smp.h).
 * asm/acpi.h is not an option, as it would require more include magic. Also
 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
 */
#ifdef CONFIG_X86
#include <asm/apic.h>
#endif

#include <asm/io.h>
#include <asm/uaccess.h>

#include <acpi/acpi_bus.h>
#include <acpi/processor.h>

#define ACPI_PROCESSOR_COMPONENT        0x01000000
#define ACPI_PROCESSOR_CLASS            "processor"
#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_idle");
#define ACPI_PROCESSOR_FILE_POWER	"power"
#define US_TO_PM_TIMER_TICKS(t)		((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
#define PM_TIMER_TICK_NS		(1000000000ULL/PM_TIMER_FREQUENCY)
#ifndef CONFIG_CPU_IDLE
#define C2_OVERHEAD			4	/* 1us (3.579 ticks per us) */
#define C3_OVERHEAD			4	/* 1us (3.579 ticks per us) */
static void (*pm_idle_save) (void) __read_mostly;
#else
#define C2_OVERHEAD			1	/* 1us */
#define C3_OVERHEAD			1	/* 1us */
#endif
#define PM_TIMER_TICKS_TO_US(p)		(((p) * 1000)/(PM_TIMER_FREQUENCY/1000))

static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
#ifdef CONFIG_CPU_IDLE
module_param(max_cstate, uint, 0000);
#else
module_param(max_cstate, uint, 0644);
#endif
static unsigned int nocst __read_mostly;
module_param(nocst, uint, 0000);

#ifndef CONFIG_CPU_IDLE
/*
 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
 * reduce history for more aggressive entry into C3
 */
static unsigned int bm_history __read_mostly =
    (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
module_param(bm_history, uint, 0644);

static int acpi_processor_set_power_policy(struct acpi_processor *pr);

#else	/* CONFIG_CPU_IDLE */
static unsigned int latency_factor __read_mostly = 2;
module_param(latency_factor, uint, 0644);
#endif

/*
 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
 * For now disable this. Probably a bug somewhere else.
 *
 * To skip this limit, boot/load with a large max_cstate limit.
 */
static int set_max_cstate(const struct dmi_system_id *id)
{
	if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
		return 0;

	printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
	       " Override with \"processor.max_cstate=%d\"\n", id->ident,
	       (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);

	max_cstate = (long)id->driver_data;

	return 0;
}

/* Actually this shouldn't be __cpuinitdata, would be better to fix the
   callers to only run once -AK */
static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
	{ set_max_cstate, "IBM ThinkPad R40e", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
	  DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
	{ set_max_cstate, "Medion 41700", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
	  DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
	{ set_max_cstate, "Clevo 5600D", {
	  DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
	  DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
	 (void *)2},
	{},
};

static inline u32 ticks_elapsed(u32 t1, u32 t2)
{
	if (t2 >= t1)
		return (t2 - t1);
	else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
		return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
	else
		return ((0xFFFFFFFF - t1) + t2);
}

static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
{
	if (t2 >= t1)
		return PM_TIMER_TICKS_TO_US(t2 - t1);
	else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
		return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
	else
		return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
}

/*
 * Callers should disable interrupts before the call and enable
 * interrupts after return.
 */
static void acpi_safe_halt(void)
{
	current_thread_info()->status &= ~TS_POLLING;
	/*
	 * TS_POLLING-cleared state must be visible before we
	 * test NEED_RESCHED:
	 */
	smp_mb();
	if (!need_resched()) {
		safe_halt();
		local_irq_disable();
	}
	current_thread_info()->status |= TS_POLLING;
}

#ifndef CONFIG_CPU_IDLE

static void
acpi_processor_power_activate(struct acpi_processor *pr,
			      struct acpi_processor_cx *new)
{
	struct acpi_processor_cx *old;

	if (!pr || !new)
		return;

	old = pr->power.state;

	if (old)
		old->promotion.count = 0;
	new->demotion.count = 0;

	/* Cleanup from old state. */
	if (old) {
		switch (old->type) {
		case ACPI_STATE_C3:
			/* Disable bus master reload */
			if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
				acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
			break;
		}
	}

	/* Prepare to use new state. */
	switch (new->type) {
	case ACPI_STATE_C3:
		/* Enable bus master reload */
		if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
			acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
		break;
	}

	pr->power.state = new;

	return;
}

static atomic_t c3_cpu_count;

/* Common C-state entry for C2, C3, .. */
static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
{
	if (cstate->entry_method == ACPI_CSTATE_FFH) {
		/* Call into architectural FFH based C-state */
		acpi_processor_ffh_cstate_enter(cstate);
	} else {
		int unused;
		/* IO port based C-state */
		inb(cstate->address);
		/* Dummy wait op - must do something useless after P_LVL2 read
		   because chipsets cannot guarantee that STPCLK# signal
		   gets asserted in time to freeze execution properly. */
		unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
	}
}
#endif /* !CONFIG_CPU_IDLE */

#ifdef ARCH_APICTIMER_STOPS_ON_C3

/*
 * Some BIOS implementations switch to C3 in the published C2 state.
 * This seems to be a common problem on AMD boxen, but other vendors
 * are affected too. We pick the most conservative approach: we assume
 * that the local APIC stops in both C2 and C3.
 */
static void acpi_timer_check_state(int state, struct acpi_processor *pr,
				   struct acpi_processor_cx *cx)
{
	struct acpi_processor_power *pwr = &pr->power;
	u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;

	/*
	 * Check, if one of the previous states already marked the lapic
	 * unstable
	 */
	if (pwr->timer_broadcast_on_state < state)
		return;

	if (cx->type >= type)
		pr->power.timer_broadcast_on_state = state;
}

static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
{
	unsigned long reason;

	reason = pr->power.timer_broadcast_on_state < INT_MAX ?
		CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;

	clockevents_notify(reason, &pr->id);
}

/* Power(C) State timer broadcast control */
static void acpi_state_timer_broadcast(struct acpi_processor *pr,
				       struct acpi_processor_cx *cx,
				       int broadcast)
{
	int state = cx - pr->power.states;

	if (state >= pr->power.timer_broadcast_on_state) {
		unsigned long reason;

		reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
			CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
		clockevents_notify(reason, &pr->id);
	}
}

#else

static void acpi_timer_check_state(int state, struct acpi_processor *pr,
				   struct acpi_processor_cx *cstate) { }
static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
static void acpi_state_timer_broadcast(struct acpi_processor *pr,
				       struct acpi_processor_cx *cx,
				       int broadcast)
{
}

#endif

/*
 * Suspend / resume control
 */
static int acpi_idle_suspend;

int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
{
	acpi_idle_suspend = 1;
	return 0;
}

int acpi_processor_resume(struct acpi_device * device)
{
	acpi_idle_suspend = 0;
	return 0;
}

#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
static int tsc_halts_in_c(int state)
{
	switch (boot_cpu_data.x86_vendor) {
	case X86_VENDOR_AMD:
		/*
		 * AMD Fam10h TSC will tick in all
		 * C/P/S0/S1 states when this bit is set.
		 */
		if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
			return 0;
		/*FALL THROUGH*/
	case X86_VENDOR_INTEL:
		/* Several cases known where TSC halts in C2 too */
	default:
		return state > ACPI_STATE_C1;
	}
}
#endif

#ifndef CONFIG_CPU_IDLE
static void acpi_processor_idle(void)
{
	struct acpi_processor *pr = NULL;
	struct acpi_processor_cx *cx = NULL;
	struct acpi_processor_cx *next_state = NULL;
	int sleep_ticks = 0;
	u32 t1, t2 = 0;

	/*
	 * Interrupts must be disabled during bus mastering calculations and
	 * for C2/C3 transitions.
	 */
	local_irq_disable();

	pr = processors[smp_processor_id()];
	if (!pr) {
		local_irq_enable();
		return;
	}

	/*
	 * Check whether we truly need to go idle, or should
	 * reschedule:
	 */
	if (unlikely(need_resched())) {
		local_irq_enable();
		return;
	}

	cx = pr->power.state;
	if (!cx || acpi_idle_suspend) {
		if (pm_idle_save)
			pm_idle_save();
		else
			acpi_safe_halt();

		if (irqs_disabled())
			local_irq_enable();

		return;
	}

	/*
	 * Check BM Activity
	 * -----------------
	 * Check for bus mastering activity (if required), record, and check
	 * for demotion.
	 */
	if (pr->flags.bm_check) {
		u32 bm_status = 0;
		unsigned long diff = jiffies - pr->power.bm_check_timestamp;

		if (diff > 31)
			diff = 31;

		pr->power.bm_activity <<= diff;

		acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
		if (bm_status) {
			pr->power.bm_activity |= 0x1;
			acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
		}
		/*
		 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
		 * the true state of bus mastering activity; forcing us to
		 * manually check the BMIDEA bit of each IDE channel.
		 */
		else if (errata.piix4.bmisx) {
			if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
			    || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
				pr->power.bm_activity |= 0x1;
		}

		pr->power.bm_check_timestamp = jiffies;

		/*
		 * If bus mastering is or was active this jiffy, demote
		 * to avoid a faulty transition.  Note that the processor
		 * won't enter a low-power state during this call (to this
		 * function) but should upon the next.
		 *
		 * TBD: A better policy might be to fallback to the demotion
		 *      state (use it for this quantum only) istead of
		 *      demoting -- and rely on duration as our sole demotion
		 *      qualification.  This may, however, introduce DMA
		 *      issues (e.g. floppy DMA transfer overrun/underrun).
		 */
		if ((pr->power.bm_activity & 0x1) &&
		    cx->demotion.threshold.bm) {
			local_irq_enable();
			next_state = cx->demotion.state;
			goto end;
		}
	}

#ifdef CONFIG_HOTPLUG_CPU
	/*
	 * Check for P_LVL2_UP flag before entering C2 and above on
	 * an SMP system. We do it here instead of doing it at _CST/P_LVL
	 * detection phase, to work cleanly with logical CPU hotplug.
	 */
	if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
	    !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
		cx = &pr->power.states[ACPI_STATE_C1];
#endif

	/*
	 * Sleep:
	 * ------
	 * Invoke the current Cx state to put the processor to sleep.
	 */
	if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
		current_thread_info()->status &= ~TS_POLLING;
		/*
		 * TS_POLLING-cleared state must be visible before we
		 * test NEED_RESCHED:
		 */
		smp_mb();
		if (need_resched()) {
			current_thread_info()->status |= TS_POLLING;
			local_irq_enable();
			return;
		}
	}

	switch (cx->type) {

	case ACPI_STATE_C1:
		/*
		 * Invoke C1.
		 * Use the appropriate idle routine, the one that would
		 * be used without acpi C-states.
		 */
		if (pm_idle_save)
			pm_idle_save();
		else
			acpi_safe_halt();

		/*
		 * TBD: Can't get time duration while in C1, as resumes
		 *      go to an ISR rather than here.  Need to instrument
		 *      base interrupt handler.
		 *
		 * Note: the TSC better not stop in C1, sched_clock() will
		 *       skew otherwise.
		 */
		sleep_ticks = 0xFFFFFFFF;
		if (irqs_disabled())
			local_irq_enable();

		break;

	case ACPI_STATE_C2:
		/* Get start time (ticks) */
		t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
		/* Tell the scheduler that we are going deep-idle: */
		sched_clock_idle_sleep_event();
		/* Invoke C2 */
		acpi_state_timer_broadcast(pr, cx, 1);
		acpi_cstate_enter(cx);
		/* Get end time (ticks) */
		t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);

#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
		/* TSC halts in C2, so notify users */
		if (tsc_halts_in_c(ACPI_STATE_C2))
			mark_tsc_unstable("possible TSC halt in C2");
#endif
		/* Compute time (ticks) that we were actually asleep */
		sleep_ticks = ticks_elapsed(t1, t2);

		/* Tell the scheduler how much we idled: */
		sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);

		/* Re-enable interrupts */
		local_irq_enable();
		/* Do not account our idle-switching overhead: */
		sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;

		current_thread_info()->status |= TS_POLLING;
		acpi_state_timer_broadcast(pr, cx, 0);
		break;

	case ACPI_STATE_C3:
		acpi_unlazy_tlb(smp_processor_id());
		/*
		 * Must be done before busmaster disable as we might
		 * need to access HPET !
		 */
		acpi_state_timer_broadcast(pr, cx, 1);
		/*
		 * disable bus master
		 * bm_check implies we need ARB_DIS
		 * !bm_check implies we need cache flush
		 * bm_control implies whether we can do ARB_DIS
		 *
		 * That leaves a case where bm_check is set and bm_control is
		 * not set. In that case we cannot do much, we enter C3
		 * without doing anything.
		 */
		if (pr->flags.bm_check && pr->flags.bm_control) {
			if (atomic_inc_return(&c3_cpu_count) ==
			    num_online_cpus()) {
				/*
				 * All CPUs are trying to go to C3
				 * Disable bus master arbitration
				 */
				acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
			}
		} else if (!pr->flags.bm_check) {
			/* SMP with no shared cache... Invalidate cache  */
			ACPI_FLUSH_CPU_CACHE();
		}

		/* Get start time (ticks) */
		t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
		/* Invoke C3 */
		/* Tell the scheduler that we are going deep-idle: */
		sched_clock_idle_sleep_event();
		acpi_cstate_enter(cx);
		/* Get end time (ticks) */
		t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
		if (pr->flags.bm_check && pr->flags.bm_control) {
			/* Enable bus master arbitration */
			atomic_dec(&c3_cpu_count);
			acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
		}

#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
		/* TSC halts in C3, so notify users */
		if (tsc_halts_in_c(ACPI_STATE_C3))
			mark_tsc_unstable("TSC halts in C3");
#endif
		/* Compute time (ticks) that we were actually asleep */
		sleep_ticks = ticks_elapsed(t1, t2);
		/* Tell the scheduler how much we idled: */
		sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);

		/* Re-enable interrupts */
		local_irq_enable();
		/* Do not account our idle-switching overhead: */
		sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;

		current_thread_info()->status |= TS_POLLING;
		acpi_state_timer_broadcast(pr, cx, 0);
		break;

	default:
		local_irq_enable();
		return;
	}
	cx->usage++;
	if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
		cx->time += sleep_ticks;

	next_state = pr->power.state;

#ifdef CONFIG_HOTPLUG_CPU
	/* Don't do promotion/demotion */
	if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
	    !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
		next_state = cx;
		goto end;
	}
#endif

	/*
	 * Promotion?
	 * ----------
	 * Track the number of longs (time asleep is greater than threshold)
	 * and promote when the count threshold is reached.  Note that bus
	 * mastering activity may prevent promotions.
	 * Do not promote above max_cstate.
	 */
	if (cx->promotion.state &&
	    ((cx->promotion.state - pr->power.states) <= max_cstate)) {
		if (sleep_ticks > cx->promotion.threshold.ticks &&
		  cx->promotion.state->latency <=
				pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
			cx->promotion.count++;
			cx->demotion.count = 0;
			if (cx->promotion.count >=
			    cx->promotion.threshold.count) {
				if (pr->flags.bm_check) {
					if (!
					    (pr->power.bm_activity & cx->
					     promotion.threshold.bm)) {
						next_state =
						    cx->promotion.state;
						goto end;
					}
				} else {
					next_state = cx->promotion.state;
					goto end;
				}
			}
		}
	}

	/*
	 * Demotion?
	 * ---------
	 * Track the number of shorts (time asleep is less than time threshold)
	 * and demote when the usage threshold is reached.
	 */
	if (cx->demotion.state) {
		if (sleep_ticks < cx->demotion.threshold.ticks) {
			cx->demotion.count++;
			cx->promotion.count = 0;
			if (cx->demotion.count >= cx->demotion.threshold.count) {
				next_state = cx->demotion.state;
				goto end;
			}
		}
	}

      end:
	/*
	 * Demote if current state exceeds max_cstate
	 * or if the latency of the current state is unacceptable
	 */
	if ((pr->power.state - pr->power.states) > max_cstate ||
		pr->power.state->latency >
				pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
		if (cx->demotion.state)
			next_state = cx->demotion.state;
	}

	/*
	 * New Cx State?
	 * -------------
	 * If we're going to start using a new Cx state we must clean up
	 * from the previous and prepare to use the new.
	 */
	if (next_state != pr->power.state)
		acpi_processor_power_activate(pr, next_state);
}

static int acpi_processor_set_power_policy(struct acpi_processor *pr)
{
	unsigned int i;
	unsigned int state_is_set = 0;
	struct acpi_processor_cx *lower = NULL;
	struct acpi_processor_cx *higher = NULL;
	struct acpi_processor_cx *cx;


	if (!pr)
		return -EINVAL;

	/*
	 * This function sets the default Cx state policy (OS idle handler).
	 * Our scheme is to promote quickly to C2 but more conservatively
	 * to C3.  We're favoring C2  for its characteristics of low latency
	 * (quick response), good power savings, and ability to allow bus
	 * mastering activity.  Note that the Cx state policy is completely
	 * customizable and can be altered dynamically.
	 */

	/* startup state */
	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
		cx = &pr->power.states[i];
		if (!cx->valid)
			continue;

		if (!state_is_set)
			pr->power.state = cx;
		state_is_set++;
		break;
	}

	if (!state_is_set)
		return -ENODEV;

	/* demotion */
	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
		cx = &pr->power.states[i];
		if (!cx->valid)
			continue;

		if (lower) {
			cx->demotion.state = lower;
			cx->demotion.threshold.ticks = cx->latency_ticks;
			cx->demotion.threshold.count = 1;
			if (cx->type == ACPI_STATE_C3)
				cx->demotion.threshold.bm = bm_history;
		}

		lower = cx;
	}

	/* promotion */
	for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
		cx = &pr->power.states[i];
		if (!cx->valid)
			continue;

		if (higher) {
			cx->promotion.state = higher;
			cx->promotion.threshold.ticks = cx->latency_ticks;
			if (cx->type >= ACPI_STATE_C2)
				cx->promotion.threshold.count = 4;
			else
				cx->promotion.threshold.count = 10;
			if (higher->type == ACPI_STATE_C3)
				cx->promotion.threshold.bm = bm_history;
		}

		higher = cx;
	}

	return 0;
}
#endif /* !CONFIG_CPU_IDLE */

static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
{

	if (!pr)
		return -EINVAL;

	if (!pr->pblk)
		return -ENODEV;

	/* if info is obtained from pblk/fadt, type equals state */
	pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
	pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;

#ifndef CONFIG_HOTPLUG_CPU
	/*
	 * Check for P_LVL2_UP flag before entering C2 and above on
	 * an SMP system.
	 */
	if ((num_online_cpus() > 1) &&
	    !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
		return -ENODEV;
#endif

	/* determine C2 and C3 address from pblk */
	pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
	pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;

	/* determine latencies from FADT */
	pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
	pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "lvl2[0x%08x] lvl3[0x%08x]\n",
			  pr->power.states[ACPI_STATE_C2].address,
			  pr->power.states[ACPI_STATE_C3].address));

	return 0;
}

static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
{
	if (!pr->power.states[ACPI_STATE_C1].valid) {
		/* set the first C-State to C1 */
		/* all processors need to support C1 */
		pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
		pr->power.states[ACPI_STATE_C1].valid = 1;
	}
	/* the C0 state only exists as a filler in our array */
	pr->power.states[ACPI_STATE_C0].valid = 1;
	return 0;
}

static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
{
	acpi_status status = 0;
	acpi_integer count;
	int current_count;
	int i;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *cst;


	if (nocst)
		return -ENODEV;

	current_count = 0;

	status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
		return -ENODEV;
	}

	cst = buffer.pointer;

	/* There must be at least 2 elements */
	if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
		printk(KERN_ERR PREFIX "not enough elements in _CST\n");
		status = -EFAULT;
		goto end;
	}

	count = cst->package.elements[0].integer.value;

	/* Validate number of power states. */
	if (count < 1 || count != cst->package.count - 1) {
		printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
		status = -EFAULT;
		goto end;
	}

	/* Tell driver that at least _CST is supported. */
	pr->flags.has_cst = 1;

	for (i = 1; i <= count; i++) {
		union acpi_object *element;
		union acpi_object *obj;
		struct acpi_power_register *reg;
		struct acpi_processor_cx cx;

		memset(&cx, 0, sizeof(cx));

		element = &(cst->package.elements[i]);
		if (element->type != ACPI_TYPE_PACKAGE)
			continue;

		if (element->package.count != 4)
			continue;

		obj = &(element->package.elements[0]);

		if (obj->type != ACPI_TYPE_BUFFER)
			continue;

		reg = (struct acpi_power_register *)obj->buffer.pointer;

		if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
		    (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
			continue;

		/* There should be an easy way to extract an integer... */
		obj = &(element->package.elements[1]);
		if (obj->type != ACPI_TYPE_INTEGER)
			continue;

		cx.type = obj->integer.value;
		/*
		 * Some buggy BIOSes won't list C1 in _CST -
		 * Let acpi_processor_get_power_info_default() handle them later
		 */
		if (i == 1 && cx.type != ACPI_STATE_C1)
			current_count++;

		cx.address = reg->address;
		cx.index = current_count + 1;

		cx.entry_method = ACPI_CSTATE_SYSTEMIO;
		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
			if (acpi_processor_ffh_cstate_probe
					(pr->id, &cx, reg) == 0) {
				cx.entry_method = ACPI_CSTATE_FFH;
			} else if (cx.type == ACPI_STATE_C1) {
				/*
				 * C1 is a special case where FIXED_HARDWARE
				 * can be handled in non-MWAIT way as well.
				 * In that case, save this _CST entry info.
				 * Otherwise, ignore this info and continue.
				 */
				cx.entry_method = ACPI_CSTATE_HALT;
				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
			} else {
				continue;
			}
		} else {
			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
				 cx.address);
		}


		obj = &(element->package.elements[2]);
		if (obj->type != ACPI_TYPE_INTEGER)
			continue;

		cx.latency = obj->integer.value;

		obj = &(element->package.elements[3]);
		if (obj->type != ACPI_TYPE_INTEGER)
			continue;

		cx.power = obj->integer.value;

		current_count++;
		memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));

		/*
		 * We support total ACPI_PROCESSOR_MAX_POWER - 1
		 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
		 */
		if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
			printk(KERN_WARNING
			       "Limiting number of power states to max (%d)\n",
			       ACPI_PROCESSOR_MAX_POWER);
			printk(KERN_WARNING
			       "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
			break;
		}
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
			  current_count));

	/* Validate number of power states discovered */
	if (current_count < 2)
		status = -EFAULT;

      end:
	kfree(buffer.pointer);

	return status;
}

static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
{

	if (!cx->address)
		return;

	/*
	 * C2 latency must be less than or equal to 100
	 * microseconds.
	 */
	else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "latency too large [%d]\n", cx->latency));
		return;
	}

	/*
	 * Otherwise we've met all of our C2 requirements.
	 * Normalize the C2 latency to expidite policy
	 */
	cx->valid = 1;

#ifndef CONFIG_CPU_IDLE
	cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
#else
	cx->latency_ticks = cx->latency;
#endif

	return;
}

static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
					   struct acpi_processor_cx *cx)
{
	static int bm_check_flag;


	if (!cx->address)
		return;

	/*
	 * C3 latency must be less than or equal to 1000
	 * microseconds.
	 */
	else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "latency too large [%d]\n", cx->latency));
		return;
	}

	/*
	 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
	 * DMA transfers are used by any ISA device to avoid livelock.
	 * Note that we could disable Type-F DMA (as recommended by
	 * the erratum), but this is known to disrupt certain ISA
	 * devices thus we take the conservative approach.
	 */
	else if (errata.piix4.fdma) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "C3 not supported on PIIX4 with Type-F DMA\n"));
		return;
	}

	/* All the logic here assumes flags.bm_check is same across all CPUs */
	if (!bm_check_flag) {
		/* Determine whether bm_check is needed based on CPU  */
		acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
		bm_check_flag = pr->flags.bm_check;
	} else {
		pr->flags.bm_check = bm_check_flag;
	}

	if (pr->flags.bm_check) {
		if (!pr->flags.bm_control) {
			if (pr->flags.has_cst != 1) {
				/* bus mastering control is necessary */
				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					"C3 support requires BM control\n"));
				return;
			} else {
				/* Here we enter C3 without bus mastering */
				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					"C3 support without BM control\n"));
			}
		}
	} else {
		/*
		 * WBINVD should be set in fadt, for C3 state to be
		 * supported on when bm_check is not required.
		 */
		if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "Cache invalidation should work properly"
					  " for C3 to be enabled on SMP systems\n"));
			return;
		}
		acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
	}

	/*
	 * Otherwise we've met all of our C3 requirements.
	 * Normalize the C3 latency to expidite policy.  Enable
	 * checking of bus mastering status (bm_check) so we can
	 * use this in our C3 policy
	 */
	cx->valid = 1;

#ifndef CONFIG_CPU_IDLE
	cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
#else
	cx->latency_ticks = cx->latency;
#endif

	return;
}

static int acpi_processor_power_verify(struct acpi_processor *pr)
{
	unsigned int i;
	unsigned int working = 0;

	pr->power.timer_broadcast_on_state = INT_MAX;

	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
		struct acpi_processor_cx *cx = &pr->power.states[i];

		switch (cx->type) {
		case ACPI_STATE_C1:
			cx->valid = 1;
			break;

		case ACPI_STATE_C2:
			acpi_processor_power_verify_c2(cx);
			if (cx->valid)
				acpi_timer_check_state(i, pr, cx);
			break;

		case ACPI_STATE_C3:
			acpi_processor_power_verify_c3(pr, cx);
			if (cx->valid)
				acpi_timer_check_state(i, pr, cx);
			break;
		}

		if (cx->valid)
			working++;
	}

	acpi_propagate_timer_broadcast(pr);

	return (working);
}

static int acpi_processor_get_power_info(struct acpi_processor *pr)
{
	unsigned int i;
	int result;


	/* NOTE: the idle thread may not be running while calling
	 * this function */

	/* Zero initialize all the C-states info. */
	memset(pr->power.states, 0, sizeof(pr->power.states));

	result = acpi_processor_get_power_info_cst(pr);
	if (result == -ENODEV)
		result = acpi_processor_get_power_info_fadt(pr);

	if (result)
		return result;

	acpi_processor_get_power_info_default(pr);

	pr->power.count = acpi_processor_power_verify(pr);

#ifndef CONFIG_CPU_IDLE
	/*
	 * Set Default Policy
	 * ------------------
	 * Now that we know which states are supported, set the default
	 * policy.  Note that this policy can be changed dynamically
	 * (e.g. encourage deeper sleeps to conserve battery life when
	 * not on AC).
	 */
	result = acpi_processor_set_power_policy(pr);
	if (result)
		return result;
#endif

	/*
	 * if one state of type C2 or C3 is available, mark this
	 * CPU as being "idle manageable"
	 */
	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
		if (pr->power.states[i].valid) {
			pr->power.count = i;
			if (pr->power.states[i].type >= ACPI_STATE_C2)
				pr->flags.power = 1;
		}
	}

	return 0;
}

static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
{
	struct acpi_processor *pr = seq->private;
	unsigned int i;


	if (!pr)
		goto end;

	seq_printf(seq, "active state:            C%zd\n"
		   "max_cstate:              C%d\n"
		   "bus master activity:     %08x\n"
		   "maximum allowed latency: %d usec\n",
		   pr->power.state ? pr->power.state - pr->power.states : 0,
		   max_cstate, (unsigned)pr->power.bm_activity,
		   pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));

	seq_puts(seq, "states:\n");

	for (i = 1; i <= pr->power.count; i++) {
		seq_printf(seq, "   %cC%d:                  ",
			   (&pr->power.states[i] ==
			    pr->power.state ? '*' : ' '), i);

		if (!pr->power.states[i].valid) {
			seq_puts(seq, "<not supported>\n");
			continue;
		}

		switch (pr->power.states[i].type) {
		case ACPI_STATE_C1:
			seq_printf(seq, "type[C1] ");
			break;
		case ACPI_STATE_C2:
			seq_printf(seq, "type[C2] ");
			break;
		case ACPI_STATE_C3:
			seq_printf(seq, "type[C3] ");
			break;
		default:
			seq_printf(seq, "type[--] ");
			break;
		}

		if (pr->power.states[i].promotion.state)
			seq_printf(seq, "promotion[C%zd] ",
				   (pr->power.states[i].promotion.state -
				    pr->power.states));
		else
			seq_puts(seq, "promotion[--] ");

		if (pr->power.states[i].demotion.state)
			seq_printf(seq, "demotion[C%zd] ",
				   (pr->power.states[i].demotion.state -
				    pr->power.states));
		else
			seq_puts(seq, "demotion[--] ");

		seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
			   pr->power.states[i].latency,
			   pr->power.states[i].usage,
			   (unsigned long long)pr->power.states[i].time);
	}

      end:
	return 0;
}

static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
{
	return single_open(file, acpi_processor_power_seq_show,
			   PDE(inode)->data);
}

static const struct file_operations acpi_processor_power_fops = {
	.open = acpi_processor_power_open_fs,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

#ifndef CONFIG_CPU_IDLE

int acpi_processor_cst_has_changed(struct acpi_processor *pr)
{
	int result = 0;


	if (!pr)
		return -EINVAL;

	if (nocst) {
		return -ENODEV;
	}

	if (!pr->flags.power_setup_done)
		return -ENODEV;

	/* Fall back to the default idle loop */
	pm_idle = pm_idle_save;
	synchronize_sched();	/* Relies on interrupts forcing exit from idle. */

	pr->flags.power = 0;
	result = acpi_processor_get_power_info(pr);
	if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
		pm_idle = acpi_processor_idle;

	return result;
}

#ifdef CONFIG_SMP
static void smp_callback(void *v)
{
	/* we already woke the CPU up, nothing more to do */
}

/*
 * This function gets called when a part of the kernel has a new latency
 * requirement.  This means we need to get all processors out of their C-state,
 * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
 * wakes them all right up.
 */
static int acpi_processor_latency_notify(struct notifier_block *b,
		unsigned long l, void *v)
{
	smp_call_function(smp_callback, NULL, 0, 1);
	return NOTIFY_OK;
}

static struct notifier_block acpi_processor_latency_notifier = {
	.notifier_call = acpi_processor_latency_notify,
};

#endif

#else /* CONFIG_CPU_IDLE */

/**
 * acpi_idle_bm_check - checks if bus master activity was detected
 */
static int acpi_idle_bm_check(void)
{
	u32 bm_status = 0;

	acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
	if (bm_status)
		acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
	/*
	 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
	 * the true state of bus mastering activity; forcing us to
	 * manually check the BMIDEA bit of each IDE channel.
	 */
	else if (errata.piix4.bmisx) {
		if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
		    || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
			bm_status = 1;
	}
	return bm_status;
}

/**
 * acpi_idle_update_bm_rld - updates the BM_RLD bit depending on target state
 * @pr: the processor
 * @target: the new target state
 */
static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
					   struct acpi_processor_cx *target)
{
	if (pr->flags.bm_rld_set && target->type != ACPI_STATE_C3) {
		acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
		pr->flags.bm_rld_set = 0;
	}

	if (!pr->flags.bm_rld_set && target->type == ACPI_STATE_C3) {
		acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
		pr->flags.bm_rld_set = 1;
	}
}

/**
 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 * @cx: cstate data
 *
 * Caller disables interrupt before call and enables interrupt after return.
 */
static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
{
	if (cx->entry_method == ACPI_CSTATE_FFH) {
		/* Call into architectural FFH based C-state */
		acpi_processor_ffh_cstate_enter(cx);
	} else if (cx->entry_method == ACPI_CSTATE_HALT) {
		acpi_safe_halt();
	} else {
		int unused;
		/* IO port based C-state */
		inb(cx->address);
		/* Dummy wait op - must do something useless after P_LVL2 read
		   because chipsets cannot guarantee that STPCLK# signal
		   gets asserted in time to freeze execution properly. */
		unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
	}
}

/**
 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 * @dev: the target CPU
 * @state: the state data
 *
 * This is equivalent to the HALT instruction.
 */
static int acpi_idle_enter_c1(struct cpuidle_device *dev,
			      struct cpuidle_state *state)
{
	u32 t1, t2;
	struct acpi_processor *pr;
	struct acpi_processor_cx *cx = cpuidle_get_statedata(state);

	pr = processors[smp_processor_id()];

	if (unlikely(!pr))
		return 0;

	local_irq_disable();

	/* Do not access any ACPI IO ports in suspend path */
	if (acpi_idle_suspend) {
		acpi_safe_halt();
		local_irq_enable();
		return 0;
	}

	if (pr->flags.bm_check)
		acpi_idle_update_bm_rld(pr, cx);

	t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
	acpi_idle_do_entry(cx);
	t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);

	local_irq_enable();
	cx->usage++;

	return ticks_elapsed_in_us(t1, t2);
}

/**
 * acpi_idle_enter_simple - enters an ACPI state without BM handling
 * @dev: the target CPU
 * @state: the state data
 */
static int acpi_idle_enter_simple(struct cpuidle_device *dev,
				  struct cpuidle_state *state)
{
	struct acpi_processor *pr;
	struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
	u32 t1, t2;
	int sleep_ticks = 0;

	pr = processors[smp_processor_id()];

	if (unlikely(!pr))
		return 0;

	if (acpi_idle_suspend)
		return(acpi_idle_enter_c1(dev, state));

	local_irq_disable();
	current_thread_info()->status &= ~TS_POLLING;
	/*
	 * TS_POLLING-cleared state must be visible before we test
	 * NEED_RESCHED:
	 */
	smp_mb();

	if (unlikely(need_resched())) {
		current_thread_info()->status |= TS_POLLING;
		local_irq_enable();
		return 0;
	}

	acpi_unlazy_tlb(smp_processor_id());
	/*
	 * Must be done before busmaster disable as we might need to
	 * access HPET !
	 */
	acpi_state_timer_broadcast(pr, cx, 1);

	if (pr->flags.bm_check)
		acpi_idle_update_bm_rld(pr, cx);

	if (cx->type == ACPI_STATE_C3)
		ACPI_FLUSH_CPU_CACHE();

	t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
	/* Tell the scheduler that we are going deep-idle: */
	sched_clock_idle_sleep_event();
	acpi_idle_do_entry(cx);
	t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);

#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
	/* TSC could halt in idle, so notify users */
	if (tsc_halts_in_c(cx->type))
		mark_tsc_unstable("TSC halts in idle");;
#endif
	sleep_ticks = ticks_elapsed(t1, t2);

	/* Tell the scheduler how much we idled: */
	sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);

	local_irq_enable();
	current_thread_info()->status |= TS_POLLING;

	cx->usage++;

	acpi_state_timer_broadcast(pr, cx, 0);
	cx->time += sleep_ticks;
	return ticks_elapsed_in_us(t1, t2);
}

static int c3_cpu_count;
static DEFINE_SPINLOCK(c3_lock);

/**
 * acpi_idle_enter_bm - enters C3 with proper BM handling
 * @dev: the target CPU
 * @state: the state data
 *
 * If BM is detected, the deepest non-C3 idle state is entered instead.
 */
static int acpi_idle_enter_bm(struct cpuidle_device *dev,
			      struct cpuidle_state *state)
{
	struct acpi_processor *pr;
	struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
	u32 t1, t2;
	int sleep_ticks = 0;

	pr = processors[smp_processor_id()];

	if (unlikely(!pr))
		return 0;

	if (acpi_idle_suspend)
		return(acpi_idle_enter_c1(dev, state));

	if (acpi_idle_bm_check()) {
		if (dev->safe_state) {
			return dev->safe_state->enter(dev, dev->safe_state);
		} else {
			local_irq_disable();
			acpi_safe_halt();
			local_irq_enable();
			return 0;
		}
	}

	local_irq_disable();
	current_thread_info()->status &= ~TS_POLLING;
	/*
	 * TS_POLLING-cleared state must be visible before we test
	 * NEED_RESCHED:
	 */
	smp_mb();

	if (unlikely(need_resched())) {
		current_thread_info()->status |= TS_POLLING;
		local_irq_enable();
		return 0;
	}

	/* Tell the scheduler that we are going deep-idle: */
	sched_clock_idle_sleep_event();
	/*
	 * Must be done before busmaster disable as we might need to
	 * access HPET !
	 */
	acpi_state_timer_broadcast(pr, cx, 1);

	acpi_idle_update_bm_rld(pr, cx);

	/*
	 * disable bus master
	 * bm_check implies we need ARB_DIS
	 * !bm_check implies we need cache flush
	 * bm_control implies whether we can do ARB_DIS
	 *
	 * That leaves a case where bm_check is set and bm_control is
	 * not set. In that case we cannot do much, we enter C3
	 * without doing anything.
	 */
	if (pr->flags.bm_check && pr->flags.bm_control) {
		spin_lock(&c3_lock);
		c3_cpu_count++;
		/* Disable bus master arbitration when all CPUs are in C3 */
		if (c3_cpu_count == num_online_cpus())
			acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
		spin_unlock(&c3_lock);
	} else if (!pr->flags.bm_check) {
		ACPI_FLUSH_CPU_CACHE();
	}

	t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
	acpi_idle_do_entry(cx);
	t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);

	/* Re-enable bus master arbitration */
	if (pr->flags.bm_check && pr->flags.bm_control) {
		spin_lock(&c3_lock);
		acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
		c3_cpu_count--;
		spin_unlock(&c3_lock);
	}

#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
	/* TSC could halt in idle, so notify users */
	if (tsc_halts_in_c(ACPI_STATE_C3))
		mark_tsc_unstable("TSC halts in idle");
#endif
	sleep_ticks = ticks_elapsed(t1, t2);
	/* Tell the scheduler how much we idled: */
	sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);

	local_irq_enable();
	current_thread_info()->status |= TS_POLLING;

	cx->usage++;

	acpi_state_timer_broadcast(pr, cx, 0);
	cx->time += sleep_ticks;
	return ticks_elapsed_in_us(t1, t2);
}

struct cpuidle_driver acpi_idle_driver = {
	.name =		"acpi_idle",
	.owner =	THIS_MODULE,
};

/**
 * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
 * @pr: the ACPI processor
 */
static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
{
	int i, count = CPUIDLE_DRIVER_STATE_START;
	struct acpi_processor_cx *cx;
	struct cpuidle_state *state;
	struct cpuidle_device *dev = &pr->power.dev;

	if (!pr->flags.power_setup_done)
		return -EINVAL;

	if (pr->flags.power == 0) {
		return -EINVAL;
	}

	for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
		dev->states[i].name[0] = '\0';
		dev->states[i].desc[0] = '\0';
	}

	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
		cx = &pr->power.states[i];
		state = &dev->states[count];

		if (!cx->valid)
			continue;

#ifdef CONFIG_HOTPLUG_CPU
		if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
		    !pr->flags.has_cst &&
		    !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
			continue;
#endif
		cpuidle_set_statedata(state, cx);

		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
		strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
		state->exit_latency = cx->latency;
		state->target_residency = cx->latency * latency_factor;
		state->power_usage = cx->power;

		state->flags = 0;
		switch (cx->type) {
			case ACPI_STATE_C1:
			state->flags |= CPUIDLE_FLAG_SHALLOW;
			state->flags |= CPUIDLE_FLAG_TIME_VALID;
			state->enter = acpi_idle_enter_c1;
			dev->safe_state = state;
			break;

			case ACPI_STATE_C2:
			state->flags |= CPUIDLE_FLAG_BALANCED;
			state->flags |= CPUIDLE_FLAG_TIME_VALID;
			state->enter = acpi_idle_enter_simple;
			dev->safe_state = state;
			break;

			case ACPI_STATE_C3:
			state->flags |= CPUIDLE_FLAG_DEEP;
			state->flags |= CPUIDLE_FLAG_TIME_VALID;
			state->flags |= CPUIDLE_FLAG_CHECK_BM;
			state->enter = pr->flags.bm_check ?
					acpi_idle_enter_bm :
					acpi_idle_enter_simple;
			break;
		}

		count++;
		if (count == CPUIDLE_STATE_MAX)
			break;
	}

	dev->state_count = count;

	if (!count)
		return -EINVAL;

	return 0;
}

int acpi_processor_cst_has_changed(struct acpi_processor *pr)
{
	int ret;

	if (!pr)
		return -EINVAL;

	if (nocst) {
		return -ENODEV;
	}

	if (!pr->flags.power_setup_done)
		return -ENODEV;

	cpuidle_pause_and_lock();
	cpuidle_disable_device(&pr->power.dev);
	acpi_processor_get_power_info(pr);
	acpi_processor_setup_cpuidle(pr);
	ret = cpuidle_enable_device(&pr->power.dev);
	cpuidle_resume_and_unlock();

	return ret;
}

#endif /* CONFIG_CPU_IDLE */

int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
			      struct acpi_device *device)
{
	acpi_status status = 0;
	static int first_run;
	struct proc_dir_entry *entry = NULL;
	unsigned int i;


	if (!first_run) {
		dmi_check_system(processor_power_dmi_table);
		max_cstate = acpi_processor_cstate_check(max_cstate);
		if (max_cstate < ACPI_C_STATES_MAX)
			printk(KERN_NOTICE
			       "ACPI: processor limited to max C-state %d\n",
			       max_cstate);
		first_run++;
#if !defined(CONFIG_CPU_IDLE) && defined(CONFIG_SMP)
		pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY,
				&acpi_processor_latency_notifier);
#endif
	}

	if (!pr)
		return -EINVAL;

	if (acpi_gbl_FADT.cst_control && !nocst) {
		status =
		    acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"Notifying BIOS of _CST ability failed"));
		}
	}

	acpi_processor_get_power_info(pr);
	pr->flags.power_setup_done = 1;

	/*
	 * Install the idle handler if processor power management is supported.
	 * Note that we use previously set idle handler will be used on
	 * platforms that only support C1.
	 */
	if ((pr->flags.power) && (!boot_option_idle_override)) {
#ifdef CONFIG_CPU_IDLE
		acpi_processor_setup_cpuidle(pr);
		pr->power.dev.cpu = pr->id;
		if (cpuidle_register_device(&pr->power.dev))
			return -EIO;
#endif

		printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
		for (i = 1; i <= pr->power.count; i++)
			if (pr->power.states[i].valid)
				printk(" C%d[C%d]", i,
				       pr->power.states[i].type);
		printk(")\n");

#ifndef CONFIG_CPU_IDLE
		if (pr->id == 0) {
			pm_idle_save = pm_idle;
			pm_idle = acpi_processor_idle;
		}
#endif
	}

	/* 'power' [R] */
	entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
				  S_IRUGO, acpi_device_dir(device));
	if (!entry)
		return -EIO;
	else {
		entry->proc_fops = &acpi_processor_power_fops;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	return 0;
}

int acpi_processor_power_exit(struct acpi_processor *pr,
			      struct acpi_device *device)
{
#ifdef CONFIG_CPU_IDLE
	if ((pr->flags.power) && (!boot_option_idle_override))
		cpuidle_unregister_device(&pr->power.dev);
#endif
	pr->flags.power_setup_done = 0;

	if (acpi_device_dir(device))
		remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
				  acpi_device_dir(device));

#ifndef CONFIG_CPU_IDLE

	/* Unregister the idle handler when processor #0 is removed. */
	if (pr->id == 0) {
		pm_idle = pm_idle_save;

		/*
		 * We are about to unload the current idle thread pm callback
		 * (pm_idle), Wait for all processors to update cached/local
		 * copies of pm_idle before proceeding.
		 */
		cpu_idle_wait();
#ifdef CONFIG_SMP
		pm_qos_remove_notifier(PM_QOS_CPU_DMA_LATENCY,
				&acpi_processor_latency_notifier);
#endif
	}
#endif

	return 0;
}