summaryrefslogtreecommitdiffstats
path: root/arch/i386/kernel/apm.c
blob: 064bbf2861f40fc4e96ed1ebfb9916b2c4731334 (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
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
/* -*- linux-c -*-
 * APM BIOS driver for Linux
 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
 *
 * Initial development of this driver was funded by NEC Australia P/L
 *	and NEC Corporation
 *
 * 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, 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.
 *
 * October 1995, Rik Faith (faith@cs.unc.edu):
 *    Minor enhancements and updates (to the patch set) for 1.3.x
 *    Documentation
 * January 1996, Rik Faith (faith@cs.unc.edu):
 *    Make /proc/apm easy to format (bump driver version)
 * March 1996, Rik Faith (faith@cs.unc.edu):
 *    Prohibit APM BIOS calls unless apm_enabled.
 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
 *    Version 1.0 and 1.1
 * May 1996, Version 1.2
 * Feb 1998, Version 1.3
 * Feb 1998, Version 1.4
 * Aug 1998, Version 1.5
 * Sep 1998, Version 1.6
 * Nov 1998, Version 1.7
 * Jan 1999, Version 1.8
 * Jan 1999, Version 1.9
 * Oct 1999, Version 1.10
 * Nov 1999, Version 1.11
 * Jan 2000, Version 1.12
 * Feb 2000, Version 1.13
 * Nov 2000, Version 1.14
 * Oct 2001, Version 1.15
 * Jan 2002, Version 1.16
 * Oct 2002, Version 1.16ac
 *
 * History:
 *    0.6b: first version in official kernel, Linux 1.3.46
 *    0.7: changed /proc/apm format, Linux 1.3.58
 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
 *    0.9: only call bios if bios is present, Linux 1.3.72
 *    1.0: use fixed device number, consolidate /proc/apm into this file,
 *         Linux 1.3.85
 *    1.1: support user-space standby and suspend, power off after system
 *         halted, Linux 1.3.98
 *    1.2: When resetting RTC after resume, take care so that the time
 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
 *         <jtoth@princeton.edu>); improve interaction between
 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
 *	   levels to the printk calls. APM is not defined for SMP machines.
 *         The new replacment for it is, but Linux doesn't yet support this.
 *         Alan Cox Linux 2.1.55
 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
 *         Dean Gaudet <dgaudet@arctic.org>.
 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
 *    1.5: Fix segment register reloading (in case of bad segments saved
 *         across BIOS call).
 *         Stephen Rothwell
 *    1.6: Cope with complier/assembler differences.
 *         Only try to turn off the first display device.
 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
 *                   <echter@informatik.uni-rostock.de>
 *         Stephen Rothwell
 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
 *         to reflect current state of APM BIOS.
 *         Chris Rankin <rankinc@bellsouth.net>
 *         Reset interrupt 0 timer to 100Hz after suspend
 *         Chad Miller <cmiller@surfsouth.com>
 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
 *         Richard Gooch <rgooch@atnf.csiro.au>
 *         Allow boot time disabling of APM
 *         Make boot messages far less verbose by default
 *         Make asm safer
 *         Stephen Rothwell
 *    1.8: Add CONFIG_APM_RTC_IS_GMT
 *         Richard Gooch <rgooch@atnf.csiro.au>
 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
 *         remove dependency on CONFIG_PROC_FS
 *         Stephen Rothwell
 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
 *         Try to cope with BIOS's that need to have all display
 *         devices blanked and not just the first one.
 *         Ross Paterson <ross@soi.city.ac.uk>
 *         Fix segment limit setting it has always been wrong as
 *         the segments needed to have byte granularity.
 *         Mark a few things __init.
 *         Add hack to allow power off of SMP systems by popular request.
 *         Use CONFIG_SMP instead of __SMP__
 *         Ignore BOUNCES for three seconds.
 *         Stephen Rothwell
 *   1.10: Fix for Thinkpad return code.
 *         Merge 2.2 and 2.3 drivers.
 *         Remove APM dependencies in arch/i386/kernel/process.c
 *         Remove APM dependencies in drivers/char/sysrq.c
 *         Reset time across standby.
 *         Allow more inititialisation on SMP.
 *         Remove CONFIG_APM_POWER_OFF and make it boot time
 *         configurable (default on).
 *         Make debug only a boot time parameter (remove APM_DEBUG).
 *         Try to blank all devices on any error.
 *   1.11: Remove APM dependencies in drivers/char/console.c
 *         Check nr_running to detect if we are idle (from
 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 *         Fix for bioses that don't zero the top part of the
 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 *         Real mode power off patch (Walter Hofmann
 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 *         the code away anyway (smp_num_cpus == 1 in UP)
 *         noted by Artur Skawina <skawina@geocities.com>.
 *         Make power off under SMP work again.
 *         Fix thinko with initial engaging of BIOS.
 *         Make sure power off only happens on CPU 0
 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 *         Do error notification to user mode if BIOS calls fail.
 *         Move entrypoint offset fix to ...boot/setup.S
 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 *         Remove smp-power-off. SMP users must now specify
 *         "apm=power-off" on the kernel command line. Suggested
 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 *         <alan@lxorguk.ukuu.org.uk>.
 *         Register the /proc/apm entry even on SMP so that
 *         scripts that check for it before doing power off
 *         work (Jim Avera <jima@hal.com>).
 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 *         <andy_henroid@yahoo.com>).
 *         Modularize the code.
 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 *         is now the way life works).
 *         Fix thinko in suspend() (wrong return).
 *         Notify drivers on critical suspend.
 *         Make kapmd absorb more idle time (Pavel Machek <pavel@suse.cz>
 *         modified by sfr).
 *         Disable interrupts while we are suspended (Andy Henroid
 *         <andy_henroid@yahoo.com> fixed by sfr).
 *         Make power off work on SMP again (Tony Hoyle
 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 *         interval is now configurable.
 *   1.14: Make connection version persist across module unload/load.
 *         Enable and engage power management earlier.
 *         Disengage power management on module unload.
 *         Changed to use the sysrq-register hack for registering the
 *         power off function called by magic sysrq based upon discussions
 *         in irc://irc.openprojects.net/#kernelnewbies
 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 *         Work around byte swap bug in one of the Vaio's BIOS's
 *         (Marc Boucher <marc@mbsi.ca>).
 *         Exposed the disable flag to dmi so that we can handle known
 *         broken APM (Alan Cox <alan@redhat.com>).
 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 *         calling it - instead idle. (Alan Cox <alan@redhat.com>)
 *         If an APM idle fails log it and idle sensibly
 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 *         Don't expect replies from clients who open the device O_RDONLY.
 *         (Idea from Thomas Hood)
 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 *         Notify listeners of standby or suspend events before notifying
 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 *         Ignore first resume after we generate our own resume event
 *         after a suspend (Thomas Hood)
 *         Daemonize now gets rid of our controlling terminal (sfr).
 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 *         idle_threshold (sfr).
 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 *
 * APM 1.1 Reference:
 *
 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 *
 * [This document is available free from Intel by calling 800.628.8686 (fax
 * 916.356.6100) or 800.548.4725; or via anonymous ftp from
 * ftp://ftp.intel.com/pub/IAL/software_specs/apmv11.doc.  It is also
 * available from Microsoft by calling 206.882.8080.]
 *
 * APM 1.2 Reference:
 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 *
 * [This document is available from Microsoft at:
 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 */

#include <linux/module.h>

#include <linux/poll.h>
#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/timer.h>
#include <linux/fcntl.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/miscdevice.h>
#include <linux/apm_bios.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/pm_legacy.h>
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/dmi.h>
#include <linux/suspend.h>
#include <linux/kthread.h>

#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/desc.h>
#include <asm/i8253.h>
#include <asm/paravirt.h>

#include "io_ports.h"

extern void machine_real_restart(unsigned char *, int);

#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
extern int (*console_blank_hook)(int);
#endif

/*
 * The apm_bios device is one of the misc char devices.
 * This is its minor number.
 */
#define	APM_MINOR_DEV	134

/*
 * See Documentation/Config.help for the configuration options.
 *
 * Various options can be changed at boot time as follows:
 * (We allow underscores for compatibility with the modules code)
 *	apm=on/off			enable/disable APM
 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 *	    					powering off
 *	    [no-]debug			log some debugging messages
 *	    [no-]power[-_]off		power off on shutdown
 *	    [no-]smp			Use apm even on an SMP box
 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 *	    				bounces
 *          idle[-_]threshold=<n>       System idle percentage above which to
 *                                      make APM BIOS idle calls. Set it to
 *                                      100 to disable.
 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 *                                      which the idle percentage is
 *                                      calculated.
 */

/* KNOWN PROBLEM MACHINES:
 *
 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 *                         [Confirmed by TI representative]
 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 *                    [Confirmed by BIOS disassembly]
 *                    [This may work now ...]
 * P: Toshiba 1950S: battery life information only gets updated after resume
 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 * 	Neale Banks <neale@lowendale.com.au> December 2000
 *
 * Legend: U = unusable with APM patches
 *         P = partially usable with APM patches
 */

/*
 * Define as 1 to make the driver always call the APM BIOS busy
 * routine even if the clock was not reported as slowed by the
 * idle routine.  Otherwise, define as 0.
 */
#define ALWAYS_CALL_BUSY   1

/*
 * Define to make the APM BIOS calls zero all data segment registers (so
 * that an incorrect BIOS implementation will cause a kernel panic if it
 * tries to write to arbitrary memory).
 */
#define APM_ZERO_SEGS

#include "apm.h"

/*
 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 * David Chen <chen@ctpa04.mit.edu>
 */
#undef INIT_TIMER_AFTER_SUSPEND

#ifdef INIT_TIMER_AFTER_SUSPEND
#include <linux/timex.h>
#include <asm/io.h>
#include <linux/delay.h>
#endif

/*
 * Need to poll the APM BIOS every second
 */
#define APM_CHECK_TIMEOUT	(HZ)

/*
 * Ignore suspend events for this amount of time after a resume
 */
#define DEFAULT_BOUNCE_INTERVAL		(3 * HZ)

/*
 * Maximum number of events stored
 */
#define APM_MAX_EVENTS		20

/*
 * The per-file APM data
 */
struct apm_user {
	int		magic;
	struct apm_user *	next;
	unsigned int	suser: 1;
	unsigned int	writer: 1;
	unsigned int	reader: 1;
	unsigned int	suspend_wait: 1;
	int		suspend_result;
	int		suspends_pending;
	int		standbys_pending;
	int		suspends_read;
	int		standbys_read;
	int		event_head;
	int		event_tail;
	apm_event_t	events[APM_MAX_EVENTS];
};

/*
 * The magic number in apm_user
 */
#define APM_BIOS_MAGIC		0x4101

/*
 * idle percentage above which bios idle calls are done
 */
#ifdef CONFIG_APM_CPU_IDLE
#define DEFAULT_IDLE_THRESHOLD	95
#else
#define DEFAULT_IDLE_THRESHOLD	100
#endif
#define DEFAULT_IDLE_PERIOD	(100 / 3)

/*
 * Local variables
 */
static struct {
	unsigned long	offset;
	unsigned short	segment;
}				apm_bios_entry;
static int			clock_slowed;
static int			idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
static int			idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
static int			set_pm_idle;
static int			suspends_pending;
static int			standbys_pending;
static int			ignore_sys_suspend;
static int			ignore_normal_resume;
static int			bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;

#ifdef CONFIG_APM_RTC_IS_GMT
#	define	clock_cmos_diff	0
#	define	got_clock_diff	1
#else
static long			clock_cmos_diff;
static int			got_clock_diff;
#endif
static int			debug __read_mostly;
static int			smp __read_mostly;
static int			apm_disabled = -1;
#ifdef CONFIG_SMP
static int			power_off;
#else
static int			power_off = 1;
#endif
#ifdef CONFIG_APM_REAL_MODE_POWER_OFF
static int			realmode_power_off = 1;
#else
static int			realmode_power_off;
#endif
#ifdef CONFIG_APM_ALLOW_INTS
static int			allow_ints = 1;
#else
static int			allow_ints;
#endif
static int			broken_psr;

static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
static struct apm_user *	user_list;
static DEFINE_SPINLOCK(user_list_lock);
static const struct desc_struct	bad_bios_desc = { 0, 0x00409200 };

static const char		driver_version[] = "1.16ac";	/* no spaces */

static struct task_struct *kapmd_task;

/*
 *	APM event names taken from the APM 1.2 specification. These are
 *	the message codes that the BIOS uses to tell us about events
 */
static const char *	const apm_event_name[] = {
	"system standby",
	"system suspend",
	"normal resume",
	"critical resume",
	"low battery",
	"power status change",
	"update time",
	"critical suspend",
	"user standby",
	"user suspend",
	"system standby resume",
	"capabilities change"
};
#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)

typedef struct lookup_t {
	int	key;
	char *	msg;
} lookup_t;

/*
 *	The BIOS returns a set of standard error codes in AX when the
 *	carry flag is set.
 */
 
static const lookup_t error_table[] = {
/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
	{ APM_DISABLED,		"Power management disabled" },
	{ APM_CONNECTED,	"Real mode interface already connected" },
	{ APM_NOT_CONNECTED,	"Interface not connected" },
	{ APM_16_CONNECTED,	"16 bit interface already connected" },
/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
	{ APM_32_CONNECTED,	"32 bit interface already connected" },
	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
	{ APM_BAD_PARAM,	"Parameter out of range" },
	{ APM_NOT_ENGAGED,	"Interface not engaged" },
	{ APM_BAD_FUNCTION,     "Function not supported" },
	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
	{ APM_BAD_STATE,	"Unable to enter requested state" },
/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
	{ APM_NO_ERROR,		"BIOS did not set a return code" },
	{ APM_NOT_PRESENT,	"No APM present" }
};
#define ERROR_COUNT	ARRAY_SIZE(error_table)

/**
 *	apm_error	-	display an APM error
 *	@str: information string
 *	@err: APM BIOS return code
 *
 *	Write a meaningful log entry to the kernel log in the event of
 *	an APM error.
 */
 
static void apm_error(char *str, int err)
{
	int	i;

	for (i = 0; i < ERROR_COUNT; i++)
		if (error_table[i].key == err) break;
	if (i < ERROR_COUNT)
		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
	else
		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
			str, err);
}

/*
 * Lock APM functionality to physical CPU 0
 */
 
#ifdef CONFIG_SMP

static cpumask_t apm_save_cpus(void)
{
	cpumask_t x = current->cpus_allowed;
	/* Some bioses don't like being called from CPU != 0 */
	set_cpus_allowed(current, cpumask_of_cpu(0));
	BUG_ON(smp_processor_id() != 0);
	return x;
}

static inline void apm_restore_cpus(cpumask_t mask)
{
	set_cpus_allowed(current, mask);
}

#else

/*
 *	No CPU lockdown needed on a uniprocessor
 */
 
#define apm_save_cpus()		(current->cpus_allowed)
#define apm_restore_cpus(x)	(void)(x)

#endif

/*
 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 * apm_info.allow_ints, we are being really paranoid here!  Not only
 * are interrupts disabled, but all the segment registers (except SS)
 * are saved and zeroed this means that if the BIOS tries to reference
 * any data without explicitly loading the segment registers, the kernel
 * will fault immediately rather than have some unforeseen circumstances
 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 * this depends on CS referring to the same physical memory as DS so that
 * DS can be zeroed before the call. Unfortunately, we can't do anything
 * about the stack segment/pointer.  Also, we tell the compiler that
 * everything could change.
 *
 * Also, we KNOW that for the non error case of apm_bios_call, there
 * is no useful data returned in the low order 8 bits of eax.
 */

static inline unsigned long __apm_irq_save(void)
{
	unsigned long flags;
	local_save_flags(flags);
	if (apm_info.allow_ints) {
		if (irqs_disabled_flags(flags))
			local_irq_enable();
	} else
		local_irq_disable();

	return flags;
}

#define apm_irq_save(flags) \
	do { flags = __apm_irq_save(); } while (0)

static inline void apm_irq_restore(unsigned long flags)
{
	if (irqs_disabled_flags(flags))
		local_irq_disable();
	else if (irqs_disabled())
		local_irq_enable();
}

#ifdef APM_ZERO_SEGS
#	define APM_DECL_SEGS \
		unsigned int saved_fs; unsigned int saved_gs;
#	define APM_DO_SAVE_SEGS \
		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
#	define APM_DO_RESTORE_SEGS \
		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
#else
#	define APM_DECL_SEGS
#	define APM_DO_SAVE_SEGS
#	define APM_DO_RESTORE_SEGS
#endif

/**
 *	apm_bios_call	-	Make an APM BIOS 32bit call
 *	@func: APM function to execute
 *	@ebx_in: EBX register for call entry
 *	@ecx_in: ECX register for call entry
 *	@eax: EAX register return
 *	@ebx: EBX register return
 *	@ecx: ECX register return
 *	@edx: EDX register return
 *	@esi: ESI register return
 *
 *	Make an APM call using the 32bit protected mode interface. The
 *	caller is responsible for knowing if APM BIOS is configured and
 *	enabled. This call can disable interrupts for a long period of
 *	time on some laptops.  The return value is in AH and the carry
 *	flag is loaded into AL.  If there is an error, then the error
 *	code is returned in AH (bits 8-15 of eax) and this function
 *	returns non-zero.
 */
 
static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
	u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
{
	APM_DECL_SEGS
	unsigned long		flags;
	cpumask_t		cpus;
	int			cpu;
	struct desc_struct	save_desc_40;
	struct desc_struct	*gdt;

	cpus = apm_save_cpus();
	
	cpu = get_cpu();
	gdt = get_cpu_gdt_table(cpu);
	save_desc_40 = gdt[0x40 / 8];
	gdt[0x40 / 8] = bad_bios_desc;

	apm_irq_save(flags);
	APM_DO_SAVE_SEGS;
	apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
	APM_DO_RESTORE_SEGS;
	apm_irq_restore(flags);
	gdt[0x40 / 8] = save_desc_40;
	put_cpu();
	apm_restore_cpus(cpus);
	
	return *eax & 0xff;
}

/**
 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 *	@func: APM function to invoke
 *	@ebx_in: EBX register value for BIOS call
 *	@ecx_in: ECX register value for BIOS call
 *	@eax: EAX register on return from the BIOS call
 *
 *	Make a BIOS call that returns one value only, or just status.
 *	If there is an error, then the error code is returned in AH
 *	(bits 8-15 of eax) and this function returns non-zero. This is
 *	used for simpler BIOS operations. This call may hold interrupts
 *	off for a long time on some laptops.
 */

static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
{
	u8			error;
	APM_DECL_SEGS
	unsigned long		flags;
	cpumask_t		cpus;
	int			cpu;
	struct desc_struct	save_desc_40;
	struct desc_struct	*gdt;

	cpus = apm_save_cpus();
	
	cpu = get_cpu();
	gdt = get_cpu_gdt_table(cpu);
	save_desc_40 = gdt[0x40 / 8];
	gdt[0x40 / 8] = bad_bios_desc;

	apm_irq_save(flags);
	APM_DO_SAVE_SEGS;
	error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
	APM_DO_RESTORE_SEGS;
	apm_irq_restore(flags);
	gdt[0x40 / 8] = save_desc_40;
	put_cpu();
	apm_restore_cpus(cpus);
	return error;
}

/**
 *	apm_driver_version	-	APM driver version
 *	@val:	loaded with the APM version on return
 *
 *	Retrieve the APM version supported by the BIOS. This is only
 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 *	probably present.
 *
 *	On entry val should point to a value indicating the APM driver
 *	version with the high byte being the major and the low byte the
 *	minor number both in BCD
 *
 *	On return it will hold the BIOS revision supported in the
 *	same format.
 */

static int apm_driver_version(u_short *val)
{
	u32	eax;

	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
		return (eax >> 8) & 0xff;
	*val = eax;
	return APM_SUCCESS;
}

/**
 *	apm_get_event	-	get an APM event from the BIOS
 *	@event: pointer to the event
 *	@info: point to the event information
 *
 *	The APM BIOS provides a polled information for event
 *	reporting. The BIOS expects to be polled at least every second
 *	when events are pending. When a message is found the caller should
 *	poll until no more messages are present.  However, this causes
 *	problems on some laptops where a suspend event notification is
 *	not cleared until it is acknowledged.
 *
 *	Additional information is returned in the info pointer, providing
 *	that APM 1.2 is in use. If no messges are pending the value 0x80
 *	is returned (No power management events pending).
 */
 
static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
{
	u32	eax;
	u32	ebx;
	u32	ecx;
	u32	dummy;

	if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
			&dummy, &dummy))
		return (eax >> 8) & 0xff;
	*event = ebx;
	if (apm_info.connection_version < 0x0102)
		*info = ~0; /* indicate info not valid */
	else
		*info = ecx;
	return APM_SUCCESS;
}

/**
 *	set_power_state	-	set the power management state
 *	@what: which items to transition
 *	@state: state to transition to
 *
 *	Request an APM change of state for one or more system devices. The
 *	processor state must be transitioned last of all. what holds the
 *	class of device in the upper byte and the device number (0xFF for
 *	all) for the object to be transitioned.
 *
 *	The state holds the state to transition to, which may in fact
 *	be an acceptance of a BIOS requested state change.
 */
 
static int set_power_state(u_short what, u_short state)
{
	u32	eax;

	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
		return (eax >> 8) & 0xff;
	return APM_SUCCESS;
}

/**
 *	set_system_power_state - set system wide power state
 *	@state: which state to enter
 *
 *	Transition the entire system into a new APM power state.
 */
 
static int set_system_power_state(u_short state)
{
	return set_power_state(APM_DEVICE_ALL, state);
}

/**
 *	apm_do_idle	-	perform power saving
 *
 *	This function notifies the BIOS that the processor is (in the view
 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 *	to handle the idle request. On a success the function returns 1
 *	if the BIOS did clock slowing or 0 otherwise.
 */
 
static int apm_do_idle(void)
{
	u32	eax;
	u8	ret = 0;
	int	idled = 0;
	int	polling;

	polling = !!(current_thread_info()->status & TS_POLLING);
	if (polling) {
		current_thread_info()->status &= ~TS_POLLING;
		/*
		 * TS_POLLING-cleared state must be visible before we
		 * test NEED_RESCHED:
		 */
		smp_mb();
	}
	if (!need_resched()) {
		idled = 1;
		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
	}
	if (polling)
		current_thread_info()->status |= TS_POLLING;

	if (!idled)
		return 0;

	if (ret) {
		static unsigned long t;

		/* This always fails on some SMP boards running UP kernels.
		 * Only report the failure the first 5 times.
		 */
		if (++t < 5)
		{
			printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
					(eax >> 8) & 0xff);
			t = jiffies;
		}
		return -1;
	}
	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
	return clock_slowed;
}

/**
 *	apm_do_busy	-	inform the BIOS the CPU is busy
 *
 *	Request that the BIOS brings the CPU back to full performance. 
 */
 
static void apm_do_busy(void)
{
	u32	dummy;

	if (clock_slowed || ALWAYS_CALL_BUSY) {
		(void) apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
		clock_slowed = 0;
	}
}

/*
 * If no process has really been interested in
 * the CPU for some time, we want to call BIOS
 * power management - we probably want
 * to conserve power.
 */
#define IDLE_CALC_LIMIT   (HZ * 100)
#define IDLE_LEAKY_MAX    16

static void (*original_pm_idle)(void) __read_mostly;

/**
 * apm_cpu_idle		-	cpu idling for APM capable Linux
 *
 * This is the idling function the kernel executes when APM is available. It 
 * tries to do BIOS powermanagement based on the average system idle time.
 * Furthermore it calls the system default idle routine.
 */

static void apm_cpu_idle(void)
{
	static int use_apm_idle; /* = 0 */
	static unsigned int last_jiffies; /* = 0 */
	static unsigned int last_stime; /* = 0 */

	int apm_idle_done = 0;
	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
	unsigned int bucket;

recalc:
	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
		use_apm_idle = 0;
		last_jiffies = jiffies;
		last_stime = current->stime;
	} else if (jiffies_since_last_check > idle_period) {
		unsigned int idle_percentage;

		idle_percentage = current->stime - last_stime;
		idle_percentage *= 100;
		idle_percentage /= jiffies_since_last_check;
		use_apm_idle = (idle_percentage > idle_threshold);
		if (apm_info.forbid_idle)
			use_apm_idle = 0;
		last_jiffies = jiffies;
		last_stime = current->stime;
	}

	bucket = IDLE_LEAKY_MAX;

	while (!need_resched()) {
		if (use_apm_idle) {
			unsigned int t;

			t = jiffies;
			switch (apm_do_idle()) {
			case 0: apm_idle_done = 1;
				if (t != jiffies) {
					if (bucket) {
						bucket = IDLE_LEAKY_MAX;
						continue;
					}
				} else if (bucket) {
					bucket--;
					continue;
				}
				break;
			case 1: apm_idle_done = 1;
				break;
			default: /* BIOS refused */
				break;
			}
		}
		if (original_pm_idle)
			original_pm_idle();
		else
			default_idle();
		jiffies_since_last_check = jiffies - last_jiffies;
		if (jiffies_since_last_check > idle_period)
			goto recalc;
	}

	if (apm_idle_done)
		apm_do_busy();
}

/**
 *	apm_power_off	-	ask the BIOS to power off
 *
 *	Handle the power off sequence. This is the one piece of code we
 *	will execute even on SMP machines. In order to deal with BIOS
 *	bugs we support real mode APM BIOS power off calls. We also make
 *	the SMP call on CPU0 as some systems will only honour this call
 *	on their first cpu.
 */
 
static void apm_power_off(void)
{
	unsigned char	po_bios_call[] = {
		0xb8, 0x00, 0x10,	/* movw  $0x1000,ax  */
		0x8e, 0xd0,		/* movw  ax,ss       */
		0xbc, 0x00, 0xf0,	/* movw  $0xf000,sp  */
		0xb8, 0x07, 0x53,	/* movw  $0x5307,ax  */
		0xbb, 0x01, 0x00,	/* movw  $0x0001,bx  */
		0xb9, 0x03, 0x00,	/* movw  $0x0003,cx  */
		0xcd, 0x15		/* int   $0x15       */
	};

	/* Some bioses don't like being called from CPU != 0 */
	if (apm_info.realmode_power_off)
	{
		(void)apm_save_cpus();
		machine_real_restart(po_bios_call, sizeof(po_bios_call));
	}
	else
		(void) set_system_power_state(APM_STATE_OFF);
}

#ifdef CONFIG_APM_DO_ENABLE

/**
 *	apm_enable_power_management - enable BIOS APM power management
 *	@enable: enable yes/no
 *
 *	Enable or disable the APM BIOS power services. 
 */
 
static int apm_enable_power_management(int enable)
{
	u32	eax;

	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
		return APM_NOT_ENGAGED;
	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
			enable, &eax))
		return (eax >> 8) & 0xff;
	if (enable)
		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
	else
		apm_info.bios.flags |= APM_BIOS_DISABLED;
	return APM_SUCCESS;
}
#endif

/**
 *	apm_get_power_status	-	get current power state
 *	@status: returned status
 *	@bat: battery info
 *	@life: estimated life
 *
 *	Obtain the current power status from the APM BIOS. We return a
 *	status which gives the rough battery status, and current power
 *	source. The bat value returned give an estimate as a percentage
 *	of life and a status value for the battery. The estimated life
 *	if reported is a lifetime in secodnds/minutes at current powwer
 *	consumption.
 */
 
static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
{
	u32	eax;
	u32	ebx;
	u32	ecx;
	u32	edx;
	u32	dummy;

	if (apm_info.get_power_status_broken)
		return APM_32_UNSUPPORTED;
	if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
			&eax, &ebx, &ecx, &edx, &dummy))
		return (eax >> 8) & 0xff;
	*status = ebx;
	*bat = ecx;
	if (apm_info.get_power_status_swabinminutes) {
		*life = swab16((u16)edx);
		*life |= 0x8000;
	} else
		*life = edx;
	return APM_SUCCESS;
}

#if 0
static int apm_get_battery_status(u_short which, u_short *status,
				  u_short *bat, u_short *life, u_short *nbat)
{
	u32	eax;
	u32	ebx;
	u32	ecx;
	u32	edx;
	u32	esi;

	if (apm_info.connection_version < 0x0102) {
		/* pretend we only have one battery. */
		if (which != 1)
			return APM_BAD_DEVICE;
		*nbat = 1;
		return apm_get_power_status(status, bat, life);
	}

	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
			&ebx, &ecx, &edx, &esi))
		return (eax >> 8) & 0xff;
	*status = ebx;
	*bat = ecx;
	*life = edx;
	*nbat = esi;
	return APM_SUCCESS;
}
#endif

/**
 *	apm_engage_power_management	-	enable PM on a device
 *	@device: identity of device
 *	@enable: on/off
 *
 *	Activate or deactive power management on either a specific device
 *	or the entire system (%APM_DEVICE_ALL).
 */
 
static int apm_engage_power_management(u_short device, int enable)
{
	u32	eax;

	if ((enable == 0) && (device == APM_DEVICE_ALL)
	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
		return APM_DISABLED;
	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
		return (eax >> 8) & 0xff;
	if (device == APM_DEVICE_ALL) {
		if (enable)
			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
		else
			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
	}
	return APM_SUCCESS;
}

#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)

/**
 *	apm_console_blank	-	blank the display
 *	@blank: on/off
 *
 *	Attempt to blank the console, firstly by blanking just video device
 *	zero, and if that fails (some BIOSes don't support it) then it blanks
 *	all video devices. Typically the BIOS will do laptop backlight and
 *	monitor powerdown for us.
 */
 
static int apm_console_blank(int blank)
{
	int error = APM_NOT_ENGAGED; /* silence gcc */
	int i;
	u_short state;
	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };

	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;

	for (i = 0; i < ARRAY_SIZE(dev); i++) {
		error = set_power_state(dev[i], state);

		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
			return 1;

		if (error == APM_NOT_ENGAGED)
			break;
	}

	if (error == APM_NOT_ENGAGED) {
		static int tried;
		int eng_error;
		if (tried++ == 0) {
			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
			if (eng_error) {
				apm_error("set display", error);
				apm_error("engage interface", eng_error);
				return 0;
			} else
				return apm_console_blank(blank);
		}
	}
	apm_error("set display", error);
	return 0;
}
#endif

static int queue_empty(struct apm_user *as)
{
	return as->event_head == as->event_tail;
}

static apm_event_t get_queued_event(struct apm_user *as)
{
	if (++as->event_tail >= APM_MAX_EVENTS)
		as->event_tail = 0;
	return as->events[as->event_tail];
}

static void queue_event(apm_event_t event, struct apm_user *sender)
{
	struct apm_user *	as;

	spin_lock(&user_list_lock);
	if (user_list == NULL)
		goto out;
	for (as = user_list; as != NULL; as = as->next) {
		if ((as == sender) || (!as->reader))
			continue;
		if (++as->event_head >= APM_MAX_EVENTS)
			as->event_head = 0;

		if (as->event_head == as->event_tail) {
			static int notified;

			if (notified++ == 0)
			    printk(KERN_ERR "apm: an event queue overflowed\n");
			if (++as->event_tail >= APM_MAX_EVENTS)
				as->event_tail = 0;
		}
		as->events[as->event_head] = event;
		if ((!as->suser) || (!as->writer))
			continue;
		switch (event) {
		case APM_SYS_SUSPEND:
		case APM_USER_SUSPEND:
			as->suspends_pending++;
			suspends_pending++;
			break;

		case APM_SYS_STANDBY:
		case APM_USER_STANDBY:
			as->standbys_pending++;
			standbys_pending++;
			break;
		}
	}
	wake_up_interruptible(&apm_waitqueue);
out:
	spin_unlock(&user_list_lock);
}

static void reinit_timer(void)
{
#ifdef INIT_TIMER_AFTER_SUSPEND
	unsigned long flags;

	spin_lock_irqsave(&i8253_lock, flags);
	/* set the clock to 100 Hz */
	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
	udelay(10);
	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
	udelay(10);
	outb(LATCH >> 8, PIT_CH0);	/* MSB */
	udelay(10);
	spin_unlock_irqrestore(&i8253_lock, flags);
#endif
}

static int suspend(int vetoable)
{
	int		err;
	struct apm_user	*as;

	if (pm_send_all(PM_SUSPEND, (void *)3)) {
		/* Vetoed */
		if (vetoable) {
			if (apm_info.connection_version > 0x100)
				set_system_power_state(APM_STATE_REJECT);
			err = -EBUSY;
			ignore_sys_suspend = 0;
			printk(KERN_WARNING "apm: suspend was vetoed.\n");
			goto out;
		}
		printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
	}

	device_suspend(PMSG_SUSPEND);
	local_irq_disable();
	device_power_down(PMSG_SUSPEND);

	local_irq_enable();

	save_processor_state();
	err = set_system_power_state(APM_STATE_SUSPEND);
	ignore_normal_resume = 1;
	restore_processor_state();

	local_irq_disable();
	reinit_timer();

	if (err == APM_NO_ERROR)
		err = APM_SUCCESS;
	if (err != APM_SUCCESS)
		apm_error("suspend", err);
	err = (err == APM_SUCCESS) ? 0 : -EIO;
	device_power_up();
	local_irq_enable();
	device_resume();
	pm_send_all(PM_RESUME, (void *)0);
	queue_event(APM_NORMAL_RESUME, NULL);
 out:
	spin_lock(&user_list_lock);
	for (as = user_list; as != NULL; as = as->next) {
		as->suspend_wait = 0;
		as->suspend_result = err;
	}
	spin_unlock(&user_list_lock);
	wake_up_interruptible(&apm_suspend_waitqueue);
	return err;
}

static void standby(void)
{
	int	err;

	local_irq_disable();
	device_power_down(PMSG_SUSPEND);
	local_irq_enable();

	err = set_system_power_state(APM_STATE_STANDBY);
	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
		apm_error("standby", err);

	local_irq_disable();
	device_power_up();
	local_irq_enable();
}

static apm_event_t get_event(void)
{
	int		error;
	apm_event_t	event = APM_NO_EVENTS; /* silence gcc */
	apm_eventinfo_t	info;

	static int notified;

	/* we don't use the eventinfo */
	error = apm_get_event(&event, &info);
	if (error == APM_SUCCESS)
		return event;

	if ((error != APM_NO_EVENTS) && (notified++ == 0))
		apm_error("get_event", error);

	return 0;
}

static void check_events(void)
{
	apm_event_t		event;
	static unsigned long	last_resume;
	static int		ignore_bounce;

	while ((event = get_event()) != 0) {
		if (debug) {
			if (event <= NR_APM_EVENT_NAME)
				printk(KERN_DEBUG "apm: received %s notify\n",
				       apm_event_name[event - 1]);
			else
				printk(KERN_DEBUG "apm: received unknown "
				       "event 0x%02x\n", event);
		}
		if (ignore_bounce
		    && ((jiffies - last_resume) > bounce_interval))
			ignore_bounce = 0;

		switch (event) {
		case APM_SYS_STANDBY:
		case APM_USER_STANDBY:
			queue_event(event, NULL);
			if (standbys_pending <= 0)
				standby();
			break;

		case APM_USER_SUSPEND:
#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
			if (apm_info.connection_version > 0x100)
				set_system_power_state(APM_STATE_REJECT);
			break;
#endif
		case APM_SYS_SUSPEND:
			if (ignore_bounce) {
				if (apm_info.connection_version > 0x100)
					set_system_power_state(APM_STATE_REJECT);
				break;
			}
			/*
			 * If we are already processing a SUSPEND,
			 * then further SUSPEND events from the BIOS
			 * will be ignored.  We also return here to
			 * cope with the fact that the Thinkpads keep
			 * sending a SUSPEND event until something else
			 * happens!
			 */
			if (ignore_sys_suspend)
				return;
			ignore_sys_suspend = 1;
			queue_event(event, NULL);
			if (suspends_pending <= 0)
				(void) suspend(1);
			break;

		case APM_NORMAL_RESUME:
		case APM_CRITICAL_RESUME:
		case APM_STANDBY_RESUME:
			ignore_sys_suspend = 0;
			last_resume = jiffies;
			ignore_bounce = 1;
			if ((event != APM_NORMAL_RESUME)
			    || (ignore_normal_resume == 0)) {
				device_resume();
				pm_send_all(PM_RESUME, (void *)0);
				queue_event(event, NULL);
			}
			ignore_normal_resume = 0;
			break;

		case APM_CAPABILITY_CHANGE:
		case APM_LOW_BATTERY:
		case APM_POWER_STATUS_CHANGE:
			queue_event(event, NULL);
			/* If needed, notify drivers here */
			break;

		case APM_UPDATE_TIME:
			break;

		case APM_CRITICAL_SUSPEND:
			/*
			 * We are not allowed to reject a critical suspend.
			 */
			(void) suspend(0);
			break;
		}
	}
}

static void apm_event_handler(void)
{
	static int	pending_count = 4;
	int		err;

	if ((standbys_pending > 0) || (suspends_pending > 0)) {
		if ((apm_info.connection_version > 0x100) &&
				(pending_count-- <= 0)) {
			pending_count = 4;
			if (debug)
				printk(KERN_DEBUG "apm: setting state busy\n");
			err = set_system_power_state(APM_STATE_BUSY);
			if (err)
				apm_error("busy", err);
		}
	} else
		pending_count = 4;
	check_events();
}

/*
 * This is the APM thread main loop.
 */

static void apm_mainloop(void)
{
	DECLARE_WAITQUEUE(wait, current);

	add_wait_queue(&apm_waitqueue, &wait);
	set_current_state(TASK_INTERRUPTIBLE);
	for (;;) {
		schedule_timeout(APM_CHECK_TIMEOUT);
		if (kthread_should_stop())
			break;
		/*
		 * Ok, check all events, check for idle (and mark us sleeping
		 * so as not to count towards the load average)..
		 */
		set_current_state(TASK_INTERRUPTIBLE);
		apm_event_handler();
	}
	remove_wait_queue(&apm_waitqueue, &wait);
}

static int check_apm_user(struct apm_user *as, const char *func)
{
	if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
		printk(KERN_ERR "apm: %s passed bad filp\n", func);
		return 1;
	}
	return 0;
}

static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
{
	struct apm_user *	as;
	int			i;
	apm_event_t		event;

	as = fp->private_data;
	if (check_apm_user(as, "read"))
		return -EIO;
	if ((int)count < sizeof(apm_event_t))
		return -EINVAL;
	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
		return -EAGAIN;
	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
	i = count;
	while ((i >= sizeof(event)) && !queue_empty(as)) {
		event = get_queued_event(as);
		if (copy_to_user(buf, &event, sizeof(event))) {
			if (i < count)
				break;
			return -EFAULT;
		}
		switch (event) {
		case APM_SYS_SUSPEND:
		case APM_USER_SUSPEND:
			as->suspends_read++;
			break;

		case APM_SYS_STANDBY:
		case APM_USER_STANDBY:
			as->standbys_read++;
			break;
		}
		buf += sizeof(event);
		i -= sizeof(event);
	}
	if (i < count)
		return count - i;
	if (signal_pending(current))
		return -ERESTARTSYS;
	return 0;
}

static unsigned int do_poll(struct file *fp, poll_table * wait)
{
	struct apm_user * as;

	as = fp->private_data;
	if (check_apm_user(as, "poll"))
		return 0;
	poll_wait(fp, &apm_waitqueue, wait);
	if (!queue_empty(as))
		return POLLIN | POLLRDNORM;
	return 0;
}

static int do_ioctl(struct inode * inode, struct file *filp,
		    u_int cmd, u_long arg)
{
	struct apm_user *	as;

	as = filp->private_data;
	if (check_apm_user(as, "ioctl"))
		return -EIO;
	if ((!as->suser) || (!as->writer))
		return -EPERM;
	switch (cmd) {
	case APM_IOC_STANDBY:
		if (as->standbys_read > 0) {
			as->standbys_read--;
			as->standbys_pending--;
			standbys_pending--;
		} else
			queue_event(APM_USER_STANDBY, as);
		if (standbys_pending <= 0)
			standby();
		break;
	case APM_IOC_SUSPEND:
		if (as->suspends_read > 0) {
			as->suspends_read--;
			as->suspends_pending--;
			suspends_pending--;
		} else
			queue_event(APM_USER_SUSPEND, as);
		if (suspends_pending <= 0) {
			return suspend(1);
		} else {
			as->suspend_wait = 1;
			wait_event_interruptible(apm_suspend_waitqueue,
					as->suspend_wait == 0);
			return as->suspend_result;
		}
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static int do_release(struct inode * inode, struct file * filp)
{
	struct apm_user *	as;

	as = filp->private_data;
	if (check_apm_user(as, "release"))
		return 0;
	filp->private_data = NULL;
	if (as->standbys_pending > 0) {
		standbys_pending -= as->standbys_pending;
		if (standbys_pending <= 0)
			standby();
	}
	if (as->suspends_pending > 0) {
		suspends_pending -= as->suspends_pending;
		if (suspends_pending <= 0)
			(void) suspend(1);
	}
  	spin_lock(&user_list_lock);
	if (user_list == as)
		user_list = as->next;
	else {
		struct apm_user *	as1;

		for (as1 = user_list;
		     (as1 != NULL) && (as1->next != as);
		     as1 = as1->next)
			;
		if (as1 == NULL)
			printk(KERN_ERR "apm: filp not in user list\n");
		else
			as1->next = as->next;
	}
	spin_unlock(&user_list_lock);
	kfree(as);
	return 0;
}

static int do_open(struct inode * inode, struct file * filp)
{
	struct apm_user *	as;

	as = kmalloc(sizeof(*as), GFP_KERNEL);
	if (as == NULL) {
		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
		       sizeof(*as));
		return -ENOMEM;
	}
	as->magic = APM_BIOS_MAGIC;
	as->event_tail = as->event_head = 0;
	as->suspends_pending = as->standbys_pending = 0;
	as->suspends_read = as->standbys_read = 0;
	/*
	 * XXX - this is a tiny bit broken, when we consider BSD
         * process accounting. If the device is opened by root, we
	 * instantly flag that we used superuser privs. Who knows,
	 * we might close the device immediately without doing a
	 * privileged operation -- cevans
	 */
	as->suser = capable(CAP_SYS_ADMIN);
	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
	spin_lock(&user_list_lock);
	as->next = user_list;
	user_list = as;
	spin_unlock(&user_list_lock);
	filp->private_data = as;
	return 0;
}

static int proc_apm_show(struct seq_file *m, void *v)
{
	unsigned short	bx;
	unsigned short	cx;
	unsigned short	dx;
	int		error;
	unsigned short  ac_line_status = 0xff;
	unsigned short  battery_status = 0xff;
	unsigned short  battery_flag   = 0xff;
	int		percentage     = -1;
	int             time_units     = -1;
	char            *units         = "?";

	if ((num_online_cpus() == 1) &&
	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
		ac_line_status = (bx >> 8) & 0xff;
		battery_status = bx & 0xff;
		if ((cx & 0xff) != 0xff)
			percentage = cx & 0xff;

		if (apm_info.connection_version > 0x100) {
			battery_flag = (cx >> 8) & 0xff;
			if (dx != 0xffff) {
				units = (dx & 0x8000) ? "min" : "sec";
				time_units = dx & 0x7fff;
			}
		}
	}
	/* Arguments, with symbols from linux/apm_bios.h.  Information is
	   from the Get Power Status (0x0a) call unless otherwise noted.

	   0) Linux driver version (this will change if format changes)
	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
	   2) APM flags from APM Installation Check (0x00):
	      bit 0: APM_16_BIT_SUPPORT
	      bit 1: APM_32_BIT_SUPPORT
	      bit 2: APM_IDLE_SLOWS_CLOCK
	      bit 3: APM_BIOS_DISABLED
	      bit 4: APM_BIOS_DISENGAGED
	   3) AC line status
	      0x00: Off-line
	      0x01: On-line
	      0x02: On backup power (BIOS >= 1.1 only)
	      0xff: Unknown
	   4) Battery status
	      0x00: High
	      0x01: Low
	      0x02: Critical
	      0x03: Charging
	      0x04: Selected battery not present (BIOS >= 1.2 only)
	      0xff: Unknown
	   5) Battery flag
	      bit 0: High
	      bit 1: Low
	      bit 2: Critical
	      bit 3: Charging
	      bit 7: No system battery
	      0xff: Unknown
	   6) Remaining battery life (percentage of charge):
	      0-100: valid
	      -1: Unknown
	   7) Remaining battery life (time units):
	      Number of remaining minutes or seconds
	      -1: Unknown
	   8) min = minutes; sec = seconds */

	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
		     driver_version,
		     (apm_info.bios.version >> 8) & 0xff,
		     apm_info.bios.version & 0xff,
		     apm_info.bios.flags,
		     ac_line_status,
		     battery_status,
		     battery_flag,
		     percentage,
		     time_units,
		     units);
	return 0;
}

static int proc_apm_open(struct inode *inode, struct file *file)
{
	return single_open(file, proc_apm_show, NULL);
}

static const struct file_operations apm_file_ops = {
	.owner		= THIS_MODULE,
	.open		= proc_apm_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int apm(void *unused)
{
	unsigned short	bx;
	unsigned short	cx;
	unsigned short	dx;
	int		error;
	char *		power_stat;
	char *		bat_stat;

#ifdef CONFIG_SMP
	/* 2002/08/01 - WT
	 * This is to avoid random crashes at boot time during initialization
	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
	 * Some bioses don't like being called from CPU != 0.
	 * Method suggested by Ingo Molnar.
	 */
	set_cpus_allowed(current, cpumask_of_cpu(0));
	BUG_ON(smp_processor_id() != 0);
#endif

	if (apm_info.connection_version == 0) {
		apm_info.connection_version = apm_info.bios.version;
		if (apm_info.connection_version > 0x100) {
			/*
			 * We only support BIOSs up to version 1.2
			 */
			if (apm_info.connection_version > 0x0102)
				apm_info.connection_version = 0x0102;
			error = apm_driver_version(&apm_info.connection_version);
			if (error != APM_SUCCESS) {
				apm_error("driver version", error);
				/* Fall back to an APM 1.0 connection. */
				apm_info.connection_version = 0x100;
			}
		}
	}

	if (debug)
		printk(KERN_INFO "apm: Connection version %d.%d\n",
			(apm_info.connection_version >> 8) & 0xff,
			apm_info.connection_version & 0xff);

#ifdef CONFIG_APM_DO_ENABLE
	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
		/*
		 * This call causes my NEC UltraLite Versa 33/C to hang if it
		 * is booted with PM disabled but not in the docking station.
		 * Unfortunate ...
		 */
		error = apm_enable_power_management(1);
		if (error) {
			apm_error("enable power management", error);
			return -1;
		}
	}
#endif

	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
	    && (apm_info.connection_version > 0x0100)) {
		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
		if (error) {
			apm_error("engage power management", error);
			return -1;
		}
	}

	if (debug && (num_online_cpus() == 1 || smp )) {
		error = apm_get_power_status(&bx, &cx, &dx);
		if (error)
			printk(KERN_INFO "apm: power status not available\n");
		else {
			switch ((bx >> 8) & 0xff) {
			case 0: power_stat = "off line"; break;
			case 1: power_stat = "on line"; break;
			case 2: power_stat = "on backup power"; break;
			default: power_stat = "unknown"; break;
			}
			switch (bx & 0xff) {
			case 0: bat_stat = "high"; break;
			case 1: bat_stat = "low"; break;
			case 2: bat_stat = "critical"; break;
			case 3: bat_stat = "charging"; break;
			default: bat_stat = "unknown"; break;
			}
			printk(KERN_INFO
			       "apm: AC %s, battery status %s, battery life ",
			       power_stat, bat_stat);
			if ((cx & 0xff) == 0xff)
				printk("unknown\n");
			else
				printk("%d%%\n", cx & 0xff);
			if (apm_info.connection_version > 0x100) {
				printk(KERN_INFO
				       "apm: battery flag 0x%02x, battery life ",
				       (cx >> 8) & 0xff);
				if (dx == 0xffff)
					printk("unknown\n");
				else
					printk("%d %s\n", dx & 0x7fff,
						(dx & 0x8000) ?
						"minutes" : "seconds");
			}
		}
	}

	/* Install our power off handler.. */
	if (power_off)
		pm_power_off = apm_power_off;

	if (num_online_cpus() == 1 || smp) {
#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
		console_blank_hook = apm_console_blank;
#endif
		apm_mainloop();
#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
		console_blank_hook = NULL;
#endif
	}

	return 0;
}

#ifndef MODULE
static int __init apm_setup(char *str)
{
	int	invert;

	while ((str != NULL) && (*str != '\0')) {
		if (strncmp(str, "off", 3) == 0)
			apm_disabled = 1;
		if (strncmp(str, "on", 2) == 0)
			apm_disabled = 0;
		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
		    (strncmp(str, "bounce_interval=", 16) == 0))
			bounce_interval = simple_strtol(str + 16, NULL, 0);
		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
		    (strncmp(str, "idle_threshold=", 15) == 0))
			idle_threshold = simple_strtol(str + 15, NULL, 0);
		if ((strncmp(str, "idle-period=", 12) == 0) ||
		    (strncmp(str, "idle_period=", 12) == 0))
			idle_period = simple_strtol(str + 12, NULL, 0);
		invert = (strncmp(str, "no-", 3) == 0) ||
			(strncmp(str, "no_", 3) == 0);
		if (invert)
			str += 3;
		if (strncmp(str, "debug", 5) == 0)
			debug = !invert;
		if ((strncmp(str, "power-off", 9) == 0) ||
		    (strncmp(str, "power_off", 9) == 0))
			power_off = !invert;
		if (strncmp(str, "smp", 3) == 0)
		{
			smp = !invert;
			idle_threshold = 100;
		}
		if ((strncmp(str, "allow-ints", 10) == 0) ||
		    (strncmp(str, "allow_ints", 10) == 0))
 			apm_info.allow_ints = !invert;
		if ((strncmp(str, "broken-psr", 10) == 0) ||
		    (strncmp(str, "broken_psr", 10) == 0))
			apm_info.get_power_status_broken = !invert;
		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
		    (strncmp(str, "realmode_power_off", 18) == 0))
			apm_info.realmode_power_off = !invert;
		str = strchr(str, ',');
		if (str != NULL)
			str += strspn(str, ", \t");
	}
	return 1;
}

__setup("apm=", apm_setup);
#endif

static const struct file_operations apm_bios_fops = {
	.owner		= THIS_MODULE,
	.read		= do_read,
	.poll		= do_poll,
	.ioctl		= do_ioctl,
	.open		= do_open,
	.release	= do_release,
};

static struct miscdevice apm_device = {
	APM_MINOR_DEV,
	"apm_bios",
	&apm_bios_fops
};


/* Simple "print if true" callback */
static int __init print_if_true(struct dmi_system_id *d)
{
	printk("%s\n", d->ident);
	return 0;
}

/*
 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
 * disabled before the suspend. Linux used to get terribly confused by that.
 */
static int __init broken_ps2_resume(struct dmi_system_id *d)
{
	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug workaround hopefully not needed.\n", d->ident);
	return 0;
}

/* Some bioses have a broken protected mode poweroff and need to use realmode */
static int __init set_realmode_power_off(struct dmi_system_id *d)
{
	if (apm_info.realmode_power_off == 0) {
		apm_info.realmode_power_off = 1;
		printk(KERN_INFO "%s bios detected. Using realmode poweroff only.\n", d->ident);
	}
	return 0;
}

/* Some laptops require interrupts to be enabled during APM calls */
static int __init set_apm_ints(struct dmi_system_id *d)
{
	if (apm_info.allow_ints == 0) {
		apm_info.allow_ints = 1;
		printk(KERN_INFO "%s machine detected. Enabling interrupts during APM calls.\n", d->ident);
	}
	return 0;
}

/* Some APM bioses corrupt memory or just plain do not work */
static int __init apm_is_horked(struct dmi_system_id *d)
{
	if (apm_info.disabled == 0) {
		apm_info.disabled = 1;
		printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
	}
	return 0;
}

static int __init apm_is_horked_d850md(struct dmi_system_id *d)
{
	if (apm_info.disabled == 0) {
		apm_info.disabled = 1;
		printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
		printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
		printk(KERN_INFO "download from support.intel.com \n");
	}
	return 0;
}

/* Some APM bioses hang on APM idle calls */
static int __init apm_likes_to_melt(struct dmi_system_id *d)
{
	if (apm_info.forbid_idle == 0) {
		apm_info.forbid_idle = 1;
		printk(KERN_INFO "%s machine detected. Disabling APM idle calls.\n", d->ident);
	}
	return 0;
}

/*
 *  Check for clue free BIOS implementations who use
 *  the following QA technique
 *
 *      [ Write BIOS Code ]<------
 *               |                ^
 *      < Does it Compile >----N--
 *               |Y               ^
 *	< Does it Boot Win98 >-N--
 *               |Y
 *           [Ship It]
 *
 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
 */
static int __init broken_apm_power(struct dmi_system_id *d)
{
	apm_info.get_power_status_broken = 1;
	printk(KERN_WARNING "BIOS strings suggest APM bugs, disabling power status reporting.\n");
	return 0;
}

/*
 * This bios swaps the APM minute reporting bytes over (Many sony laptops
 * have this problem).
 */
static int __init swab_apm_power_in_minutes(struct dmi_system_id *d)
{
	apm_info.get_power_status_swabinminutes = 1;
	printk(KERN_WARNING "BIOS strings suggest APM reports battery life in minutes and wrong byte order.\n");
	return 0;
}

static struct dmi_system_id __initdata apm_dmi_table[] = {
	{
		print_if_true,
		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
	},
	{	/* Handle problems with APM on the C600 */
		broken_ps2_resume, "Dell Latitude C600",
		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
	},
	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
		set_apm_ints, "Dell Latitude",
		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
	},
	{	/* APM crashes */
		apm_is_horked, "Dell Inspiron 2500",
		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
			DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
	},
	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
		set_apm_ints, "Dell Inspiron", {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
	},
	{	/* Handle problems with APM on Inspiron 5000e */
		broken_apm_power, "Dell Inspiron 5000e",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
	},
	{	/* Handle problems with APM on Inspiron 2500 */
		broken_apm_power, "Dell Inspiron 2500",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
	},
	{	/* APM crashes */
		apm_is_horked, "Dell Dimension 4100",
		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
			DMI_MATCH(DMI_BIOS_VENDOR,"Intel Corp."),
			DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
	},
	{	/* Allow interrupts during suspend on Compaq Laptops*/
		set_apm_ints, "Compaq 12XL125",
		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION,"4.06"), },
	},
	{	/* Allow interrupts during APM or the clock goes slow */
		set_apm_ints, "ASUSTeK",
		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
	},
	{	/* APM blows on shutdown */
		apm_is_horked, "ABIT KX7-333[R]",
		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
	},
	{	/* APM crashes */
		apm_is_horked, "Trigem Delhi3",
		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
	},
	{	/* APM crashes */
		apm_is_horked, "Fujitsu-Siemens",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
	},
	{	/* APM crashes */
		apm_is_horked_d850md, "Intel D850MD",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
	},
	{	/* APM crashes */
		apm_is_horked, "Intel D810EMO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
	},
	{	/* APM crashes */
		apm_is_horked, "Dell XPS-Z",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
	},
	{	/* APM crashes */
		apm_is_horked, "Sharp PC-PJ/AX",
		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
			DMI_MATCH(DMI_BIOS_VENDOR,"SystemSoft"),
			DMI_MATCH(DMI_BIOS_VERSION,"Version R2.08"), },
	},
	{	/* APM crashes */
		apm_is_horked, "Dell Inspiron 2500",
		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
			DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
	},
	{	/* APM idle hangs */
		apm_likes_to_melt, "Jabil AMD",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
	},
	{	/* APM idle hangs */
		apm_likes_to_melt, "AMI Bios",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
	},

	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
	},
	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
		swab_apm_power_in_minutes, "Sony VAIO",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
	},
	{	/* broken PM poweroff bios */
		set_realmode_power_off, "Award Software v4.60 PGMA",
		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
	},

	/* Generic per vendor APM settings  */

	{	/* Allow interrupts during suspend on IBM laptops */
		set_apm_ints, "IBM",
		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
	},

	{ }
};

/*
 * Just start the APM thread. We do NOT want to do APM BIOS
 * calls from anything but the APM thread, if for no other reason
 * than the fact that we don't trust the APM BIOS. This way,
 * most common APM BIOS problems that lead to protection errors
 * etc will have at least some level of being contained...
 *
 * In short, if something bad happens, at least we have a choice
 * of just killing the apm thread..
 */
static int __init apm_init(void)
{
	struct proc_dir_entry *apm_proc;
	struct desc_struct *gdt;
	int err;

	dmi_check_system(apm_dmi_table);

	if (apm_info.bios.version == 0 || paravirt_enabled()) {
		printk(KERN_INFO "apm: BIOS not found.\n");
		return -ENODEV;
	}
	printk(KERN_INFO
		"apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
		((apm_info.bios.version >> 8) & 0xff),
		(apm_info.bios.version & 0xff),
		apm_info.bios.flags,
		driver_version);
	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
		return -ENODEV;
	}

	if (allow_ints)
		apm_info.allow_ints = 1;
	if (broken_psr)
		apm_info.get_power_status_broken = 1;
	if (realmode_power_off)
		apm_info.realmode_power_off = 1;
	/* User can override, but default is to trust DMI */
	if (apm_disabled != -1)
		apm_info.disabled = apm_disabled;

	/*
	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
	 * but is reportedly a 1.0 BIOS.
	 */
	if (apm_info.bios.version == 0x001)
		apm_info.bios.version = 0x100;

	/* BIOS < 1.2 doesn't set cseg_16_len */
	if (apm_info.bios.version < 0x102)
		apm_info.bios.cseg_16_len = 0; /* 64k */

	if (debug) {
		printk(KERN_INFO "apm: entry %x:%lx cseg16 %x dseg %x",
			apm_info.bios.cseg, apm_info.bios.offset,
			apm_info.bios.cseg_16, apm_info.bios.dseg);
		if (apm_info.bios.version > 0x100)
			printk(" cseg len %x, dseg len %x",
				apm_info.bios.cseg_len,
				apm_info.bios.dseg_len);
		if (apm_info.bios.version > 0x101)
			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
		printk("\n");
	}

	if (apm_info.disabled) {
		printk(KERN_NOTICE "apm: disabled on user request.\n");
		return -ENODEV;
	}
	if ((num_online_cpus() > 1) && !power_off && !smp) {
		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
		apm_info.disabled = 1;
		return -ENODEV;
	}
	if (PM_IS_ACTIVE()) {
		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
		apm_info.disabled = 1;
		return -ENODEV;
	}
#ifdef CONFIG_PM_LEGACY
	pm_active = 1;
#endif

	/*
	 * Set up a segment that references the real mode segment 0x40
	 * that extends up to the end of page zero (that we have reserved).
	 * This is for buggy BIOS's that refer to (real mode) segment 0x40
	 * even though they are called in protected mode.
	 */
	set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
	_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));

	/*
	 * Set up the long jump entry point to the APM BIOS, which is called
	 * from inline assembly.
	 */
	apm_bios_entry.offset = apm_info.bios.offset;
	apm_bios_entry.segment = APM_CS;

	/*
	 * The APM 1.1 BIOS is supposed to provide limit information that it
	 * recognizes.  Many machines do this correctly, but many others do
	 * not restrict themselves to their claimed limit.  When this happens,
	 * they will cause a segmentation violation in the kernel at boot time.
	 * Most BIOS's, however, will respect a 64k limit, so we use that.
	 *
	 * Note we only set APM segments on CPU zero, since we pin the APM
	 * code to that CPU.
	 */
	gdt = get_cpu_gdt_table(0);
	set_base(gdt[APM_CS >> 3],
		 __va((unsigned long)apm_info.bios.cseg << 4));
	set_base(gdt[APM_CS_16 >> 3],
		 __va((unsigned long)apm_info.bios.cseg_16 << 4));
	set_base(gdt[APM_DS >> 3],
		 __va((unsigned long)apm_info.bios.dseg << 4));

	apm_proc = create_proc_entry("apm", 0, NULL);
	if (apm_proc)
		apm_proc->proc_fops = &apm_file_ops;

	kapmd_task = kthread_create(apm, NULL, "kapmd");
	if (IS_ERR(kapmd_task)) {
		printk(KERN_ERR "apm: disabled - Unable to start kernel "
				"thread.\n");
		err = PTR_ERR(kapmd_task);
		kapmd_task = NULL;
		remove_proc_entry("apm", NULL);
		return err;
	}
	kapmd_task->flags |= PF_NOFREEZE;
	wake_up_process(kapmd_task);

	if (num_online_cpus() > 1 && !smp ) {
		printk(KERN_NOTICE
		   "apm: disabled - APM is not SMP safe (power off active).\n");
		return 0;
	}

	/*
	 * Note we don't actually care if the misc_device cannot be registered.
	 * this driver can do its job without it, even if userspace can't
	 * control it.  just log the error
	 */
	if (misc_register(&apm_device))
		printk(KERN_WARNING "apm: Could not register misc device.\n");

	if (HZ != 100)
		idle_period = (idle_period * HZ) / 100;
	if (idle_threshold < 100) {
		original_pm_idle = pm_idle;
		pm_idle  = apm_cpu_idle;
		set_pm_idle = 1;
	}

	return 0;
}

static void __exit apm_exit(void)
{
	int	error;

	if (set_pm_idle) {
		pm_idle = original_pm_idle;
		/*
		 * 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();
	}
	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
	    && (apm_info.connection_version > 0x0100)) {
		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
		if (error)
			apm_error("disengage power management", error);
	}
	misc_deregister(&apm_device);
	remove_proc_entry("apm", NULL);
	if (power_off)
		pm_power_off = NULL;
	if (kapmd_task) {
		kthread_stop(kapmd_task);
		kapmd_task = NULL;
	}
#ifdef CONFIG_PM_LEGACY
	pm_active = 0;
#endif
}

module_init(apm_init);
module_exit(apm_exit);

MODULE_AUTHOR("Stephen Rothwell");
MODULE_DESCRIPTION("Advanced Power Management");
MODULE_LICENSE("GPL");
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "Enable debug mode");
module_param(power_off, bool, 0444);
MODULE_PARM_DESC(power_off, "Enable power off");
module_param(bounce_interval, int, 0444);
MODULE_PARM_DESC(bounce_interval,
		"Set the number of ticks to ignore suspend bounces");
module_param(allow_ints, bool, 0444);
MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
module_param(broken_psr, bool, 0444);
MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
module_param(realmode_power_off, bool, 0444);
MODULE_PARM_DESC(realmode_power_off,
		"Switch to real mode before powering off");
module_param(idle_threshold, int, 0444);
MODULE_PARM_DESC(idle_threshold,
	"System idle percentage above which to make APM BIOS idle calls");
module_param(idle_period, int, 0444);
MODULE_PARM_DESC(idle_period,
	"Period (in sec/100) over which to caculate the idle percentage");
module_param(smp, bool, 0444);
MODULE_PARM_DESC(smp,
	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
OpenPOWER on IntegriCloud