summaryrefslogtreecommitdiffstats
path: root/drivers/char/ipmi/ipmi_ssif.c
blob: 0b22a9be5029155265c0d648e14f1833a5ba4ada (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
/*
 * ipmi_ssif.c
 *
 * The interface to the IPMI driver for SMBus access to a SMBus
 * compliant device.  Called SSIF by the IPMI spec.
 *
 * Author: Intel Corporation
 *         Todd Davis <todd.c.davis@intel.com>
 *
 * Rewritten by Corey Minyard <minyard@acm.org> to support the
 * non-blocking I2C interface, add support for multi-part
 * transactions, add PEC support, and general clenaup.
 *
 * Copyright 2003 Intel Corporation
 * Copyright 2005 MontaVista Software
 *
 *  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 file holds the "policy" for the interface to the SSIF state
 * machine.  It does the configuration, handles timers and interrupts,
 * and drives the real SSIF state machine.
 */

/*
 * TODO: Figure out how to use SMB alerts.  This will require a new
 * interface into the I2C driver, I believe.
 */

#if defined(MODVERSIONS)
#include <linux/modversions.h>
#endif

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/i2c.h>
#include <linux/ipmi_smi.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/kthread.h>
#include <linux/acpi.h>
#include <linux/ctype.h>
#include <linux/time64.h>

#define PFX "ipmi_ssif: "
#define DEVICE_NAME "ipmi_ssif"

#define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD	0x57

#define	SSIF_IPMI_REQUEST			2
#define	SSIF_IPMI_MULTI_PART_REQUEST_START	6
#define	SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE	7
#define	SSIF_IPMI_RESPONSE			3
#define	SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE	9

/* ssif_debug is a bit-field
 *	SSIF_DEBUG_MSG -	commands and their responses
 *	SSIF_DEBUG_STATES -	message states
 *	SSIF_DEBUG_TIMING -	 Measure times between events in the driver
 */
#define SSIF_DEBUG_TIMING	4
#define SSIF_DEBUG_STATE	2
#define SSIF_DEBUG_MSG		1
#define SSIF_NODEBUG		0
#define SSIF_DEFAULT_DEBUG	(SSIF_NODEBUG)

/*
 * Timer values
 */
#define SSIF_MSG_USEC		20000	/* 20ms between message tries. */
#define SSIF_MSG_PART_USEC	5000	/* 5ms for a message part */

/* How many times to we retry sending/receiving the message. */
#define	SSIF_SEND_RETRIES	5
#define	SSIF_RECV_RETRIES	250

#define SSIF_MSG_MSEC		(SSIF_MSG_USEC / 1000)
#define SSIF_MSG_JIFFIES	((SSIF_MSG_USEC * 1000) / TICK_NSEC)
#define SSIF_MSG_PART_JIFFIES	((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)

enum ssif_intf_state {
	SSIF_NORMAL,
	SSIF_GETTING_FLAGS,
	SSIF_GETTING_EVENTS,
	SSIF_CLEARING_FLAGS,
	SSIF_GETTING_MESSAGES,
	/* FIXME - add watchdog stuff. */
};

#define SSIF_IDLE(ssif)	 ((ssif)->ssif_state == SSIF_NORMAL \
			  && (ssif)->curr_msg == NULL)

/*
 * Indexes into stats[] in ssif_info below.
 */
enum ssif_stat_indexes {
	/* Number of total messages sent. */
	SSIF_STAT_sent_messages = 0,

	/*
	 * Number of message parts sent.  Messages may be broken into
	 * parts if they are long.
	 */
	SSIF_STAT_sent_messages_parts,

	/*
	 * Number of time a message was retried.
	 */
	SSIF_STAT_send_retries,

	/*
	 * Number of times the send of a message failed.
	 */
	SSIF_STAT_send_errors,

	/*
	 * Number of message responses received.
	 */
	SSIF_STAT_received_messages,

	/*
	 * Number of message fragments received.
	 */
	SSIF_STAT_received_message_parts,

	/*
	 * Number of times the receive of a message was retried.
	 */
	SSIF_STAT_receive_retries,

	/*
	 * Number of errors receiving messages.
	 */
	SSIF_STAT_receive_errors,

	/*
	 * Number of times a flag fetch was requested.
	 */
	SSIF_STAT_flag_fetches,

	/*
	 * Number of times the hardware didn't follow the state machine.
	 */
	SSIF_STAT_hosed,

	/*
	 * Number of received events.
	 */
	SSIF_STAT_events,

	/* Number of asyncronous messages received. */
	SSIF_STAT_incoming_messages,

	/* Number of watchdog pretimeouts. */
	SSIF_STAT_watchdog_pretimeouts,

	/* Number of alers received. */
	SSIF_STAT_alerts,

	/* Always add statistics before this value, it must be last. */
	SSIF_NUM_STATS
};

struct ssif_addr_info {
	struct i2c_board_info binfo;
	char *adapter_name;
	int debug;
	int slave_addr;
	enum ipmi_addr_src addr_src;
	union ipmi_smi_info_union addr_info;

	struct mutex clients_mutex;
	struct list_head clients;

	struct list_head link;
};

struct ssif_info;

typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
			     unsigned char *data, unsigned int len);

struct ssif_info {
	ipmi_smi_t          intf;
	int                 intf_num;
	spinlock_t	    lock;
	struct ipmi_smi_msg *waiting_msg;
	struct ipmi_smi_msg *curr_msg;
	enum ssif_intf_state ssif_state;
	unsigned long       ssif_debug;

	struct ipmi_smi_handlers handlers;

	enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
	union ipmi_smi_info_union addr_info;

	/*
	 * Flags from the last GET_MSG_FLAGS command, used when an ATTN
	 * is set to hold the flags until we are done handling everything
	 * from the flags.
	 */
#define RECEIVE_MSG_AVAIL	0x01
#define EVENT_MSG_BUFFER_FULL	0x02
#define WDT_PRE_TIMEOUT_INT	0x08
	unsigned char       msg_flags;

	u8		    global_enables;
	bool		    has_event_buffer;
	bool		    supports_alert;

	/*
	 * Used to tell what we should do with alerts.  If we are
	 * waiting on a response, read the data immediately.
	 */
	bool		    got_alert;
	bool		    waiting_alert;

	/*
	 * If set to true, this will request events the next time the
	 * state machine is idle.
	 */
	bool                req_events;

	/*
	 * If set to true, this will request flags the next time the
	 * state machine is idle.
	 */
	bool                req_flags;

	/*
	 * Used to perform timer operations when run-to-completion
	 * mode is on.  This is a countdown timer.
	 */
	int                 rtc_us_timer;

	/* Used for sending/receiving data.  +1 for the length. */
	unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
	unsigned int  data_len;

	/* Temp receive buffer, gets copied into data. */
	unsigned char recv[I2C_SMBUS_BLOCK_MAX];

	struct i2c_client *client;
	ssif_i2c_done done_handler;

	/* Thread interface handling */
	struct task_struct *thread;
	struct completion wake_thread;
	bool stopping;
	int i2c_read_write;
	int i2c_command;
	unsigned char *i2c_data;
	unsigned int i2c_size;

	/* From the device id response. */
	struct ipmi_device_id device_id;

	struct timer_list retry_timer;
	int retries_left;

	/* Info from SSIF cmd */
	unsigned char max_xmit_msg_size;
	unsigned char max_recv_msg_size;
	unsigned int  multi_support;
	int           supports_pec;

#define SSIF_NO_MULTI		0
#define SSIF_MULTI_2_PART	1
#define SSIF_MULTI_n_PART	2
	unsigned char *multi_data;
	unsigned int  multi_len;
	unsigned int  multi_pos;

	atomic_t stats[SSIF_NUM_STATS];
};

#define ssif_inc_stat(ssif, stat) \
	atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
#define ssif_get_stat(ssif, stat) \
	((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))

static bool initialized;

static atomic_t next_intf = ATOMIC_INIT(0);

static void return_hosed_msg(struct ssif_info *ssif_info,
			     struct ipmi_smi_msg *msg);
static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
static int start_send(struct ssif_info *ssif_info,
		      unsigned char   *data,
		      unsigned int    len);

static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
					  unsigned long *flags)
{
	spin_lock_irqsave(&ssif_info->lock, *flags);
	return flags;
}

static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
				  unsigned long *flags)
{
	spin_unlock_irqrestore(&ssif_info->lock, *flags);
}

static void deliver_recv_msg(struct ssif_info *ssif_info,
			     struct ipmi_smi_msg *msg)
{
	ipmi_smi_t    intf = ssif_info->intf;

	if (!intf) {
		ipmi_free_smi_msg(msg);
	} else if (msg->rsp_size < 0) {
		return_hosed_msg(ssif_info, msg);
		pr_err(PFX
		       "Malformed message in deliver_recv_msg: rsp_size = %d\n",
		       msg->rsp_size);
	} else {
		ipmi_smi_msg_received(intf, msg);
	}
}

static void return_hosed_msg(struct ssif_info *ssif_info,
			     struct ipmi_smi_msg *msg)
{
	ssif_inc_stat(ssif_info, hosed);

	/* Make it a response */
	msg->rsp[0] = msg->data[0] | 4;
	msg->rsp[1] = msg->data[1];
	msg->rsp[2] = 0xFF; /* Unknown error. */
	msg->rsp_size = 3;

	deliver_recv_msg(ssif_info, msg);
}

/*
 * Must be called with the message lock held.  This will release the
 * message lock.  Note that the caller will check SSIF_IDLE and start a
 * new operation, so there is no need to check for new messages to
 * start in here.
 */
static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
{
	unsigned char msg[3];

	ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
	ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
	ipmi_ssif_unlock_cond(ssif_info, flags);

	/* Make sure the watchdog pre-timeout flag is not set at startup. */
	msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
	msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
	msg[2] = WDT_PRE_TIMEOUT_INT;

	if (start_send(ssif_info, msg, 3) != 0) {
		/* Error, just go to normal state. */
		ssif_info->ssif_state = SSIF_NORMAL;
	}
}

static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
{
	unsigned char mb[2];

	ssif_info->req_flags = false;
	ssif_info->ssif_state = SSIF_GETTING_FLAGS;
	ipmi_ssif_unlock_cond(ssif_info, flags);

	mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
	mb[1] = IPMI_GET_MSG_FLAGS_CMD;
	if (start_send(ssif_info, mb, 2) != 0)
		ssif_info->ssif_state = SSIF_NORMAL;
}

static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
			     struct ipmi_smi_msg *msg)
{
	if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
		unsigned long oflags;

		flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
		ssif_info->curr_msg = NULL;
		ssif_info->ssif_state = SSIF_NORMAL;
		ipmi_ssif_unlock_cond(ssif_info, flags);
		ipmi_free_smi_msg(msg);
	}
}

static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
{
	struct ipmi_smi_msg *msg;

	ssif_info->req_events = false;

	msg = ipmi_alloc_smi_msg();
	if (!msg) {
		ssif_info->ssif_state = SSIF_NORMAL;
		return;
	}

	ssif_info->curr_msg = msg;
	ssif_info->ssif_state = SSIF_GETTING_EVENTS;
	ipmi_ssif_unlock_cond(ssif_info, flags);

	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
	msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
	msg->data_size = 2;

	check_start_send(ssif_info, flags, msg);
}

static void start_recv_msg_fetch(struct ssif_info *ssif_info,
				 unsigned long *flags)
{
	struct ipmi_smi_msg *msg;

	msg = ipmi_alloc_smi_msg();
	if (!msg) {
		ssif_info->ssif_state = SSIF_NORMAL;
		return;
	}

	ssif_info->curr_msg = msg;
	ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
	ipmi_ssif_unlock_cond(ssif_info, flags);

	msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
	msg->data[1] = IPMI_GET_MSG_CMD;
	msg->data_size = 2;

	check_start_send(ssif_info, flags, msg);
}

/*
 * Must be called with the message lock held.  This will release the
 * message lock.  Note that the caller will check SSIF_IDLE and start a
 * new operation, so there is no need to check for new messages to
 * start in here.
 */
static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
{
	if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
		ipmi_smi_t intf = ssif_info->intf;
		/* Watchdog pre-timeout */
		ssif_inc_stat(ssif_info, watchdog_pretimeouts);
		start_clear_flags(ssif_info, flags);
		if (intf)
			ipmi_smi_watchdog_pretimeout(intf);
	} else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
		/* Messages available. */
		start_recv_msg_fetch(ssif_info, flags);
	else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
		/* Events available. */
		start_event_fetch(ssif_info, flags);
	else {
		ssif_info->ssif_state = SSIF_NORMAL;
		ipmi_ssif_unlock_cond(ssif_info, flags);
	}
}

static int ipmi_ssif_thread(void *data)
{
	struct ssif_info *ssif_info = data;

	while (!kthread_should_stop()) {
		int result;

		/* Wait for something to do */
		result = wait_for_completion_interruptible(
						&ssif_info->wake_thread);
		if (ssif_info->stopping)
			break;
		if (result == -ERESTARTSYS)
			continue;
		init_completion(&ssif_info->wake_thread);

		if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
			result = i2c_smbus_write_block_data(
				ssif_info->client, ssif_info->i2c_command,
				ssif_info->i2c_data[0],
				ssif_info->i2c_data + 1);
			ssif_info->done_handler(ssif_info, result, NULL, 0);
		} else {
			result = i2c_smbus_read_block_data(
				ssif_info->client, ssif_info->i2c_command,
				ssif_info->i2c_data);
			if (result < 0)
				ssif_info->done_handler(ssif_info, result,
							NULL, 0);
			else
				ssif_info->done_handler(ssif_info, 0,
							ssif_info->i2c_data,
							result);
		}
	}

	return 0;
}

static int ssif_i2c_send(struct ssif_info *ssif_info,
			ssif_i2c_done handler,
			int read_write, int command,
			unsigned char *data, unsigned int size)
{
	ssif_info->done_handler = handler;

	ssif_info->i2c_read_write = read_write;
	ssif_info->i2c_command = command;
	ssif_info->i2c_data = data;
	ssif_info->i2c_size = size;
	complete(&ssif_info->wake_thread);
	return 0;
}


static void msg_done_handler(struct ssif_info *ssif_info, int result,
			     unsigned char *data, unsigned int len);

static void start_get(struct ssif_info *ssif_info)
{
	int rv;

	ssif_info->rtc_us_timer = 0;
	ssif_info->multi_pos = 0;

	rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
			  SSIF_IPMI_RESPONSE,
			  ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
	if (rv < 0) {
		/* request failed, just return the error. */
		if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
			pr_info("Error from i2c_non_blocking_op(5)\n");

		msg_done_handler(ssif_info, -EIO, NULL, 0);
	}
}

static void retry_timeout(unsigned long data)
{
	struct ssif_info *ssif_info = (void *) data;
	unsigned long oflags, *flags;
	bool waiting;

	if (ssif_info->stopping)
		return;

	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
	waiting = ssif_info->waiting_alert;
	ssif_info->waiting_alert = false;
	ipmi_ssif_unlock_cond(ssif_info, flags);

	if (waiting)
		start_get(ssif_info);
}


static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
		       unsigned int data)
{
	struct ssif_info *ssif_info = i2c_get_clientdata(client);
	unsigned long oflags, *flags;
	bool do_get = false;

	if (type != I2C_PROTOCOL_SMBUS_ALERT)
		return;

	ssif_inc_stat(ssif_info, alerts);

	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
	if (ssif_info->waiting_alert) {
		ssif_info->waiting_alert = false;
		del_timer(&ssif_info->retry_timer);
		do_get = true;
	} else if (ssif_info->curr_msg) {
		ssif_info->got_alert = true;
	}
	ipmi_ssif_unlock_cond(ssif_info, flags);
	if (do_get)
		start_get(ssif_info);
}

static int start_resend(struct ssif_info *ssif_info);

static void msg_done_handler(struct ssif_info *ssif_info, int result,
			     unsigned char *data, unsigned int len)
{
	struct ipmi_smi_msg *msg;
	unsigned long oflags, *flags;
	int rv;

	/*
	 * We are single-threaded here, so no need for a lock until we
	 * start messing with driver states or the queues.
	 */

	if (result < 0) {
		ssif_info->retries_left--;
		if (ssif_info->retries_left > 0) {
			ssif_inc_stat(ssif_info, receive_retries);

			flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
			ssif_info->waiting_alert = true;
			ssif_info->rtc_us_timer = SSIF_MSG_USEC;
			mod_timer(&ssif_info->retry_timer,
				  jiffies + SSIF_MSG_JIFFIES);
			ipmi_ssif_unlock_cond(ssif_info, flags);
			return;
		}

		ssif_inc_stat(ssif_info, receive_errors);

		if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
			pr_info("Error in msg_done_handler: %d\n", result);
		len = 0;
		goto continue_op;
	}

	if ((len > 1) && (ssif_info->multi_pos == 0)
				&& (data[0] == 0x00) && (data[1] == 0x01)) {
		/* Start of multi-part read.  Start the next transaction. */
		int i;

		ssif_inc_stat(ssif_info, received_message_parts);

		/* Remove the multi-part read marker. */
		len -= 2;
		for (i = 0; i < len; i++)
			ssif_info->data[i] = data[i+2];
		ssif_info->multi_len = len;
		ssif_info->multi_pos = 1;

		rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
				  SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
				  ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
		if (rv < 0) {
			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
				pr_info("Error from i2c_non_blocking_op(1)\n");

			result = -EIO;
		} else
			return;
	} else if (ssif_info->multi_pos) {
		/* Middle of multi-part read.  Start the next transaction. */
		int i;
		unsigned char blocknum;

		if (len == 0) {
			result = -EIO;
			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
				pr_info(PFX "Middle message with no data\n");

			goto continue_op;
		}

		blocknum = data[0];

		if (ssif_info->multi_len + len - 1 > IPMI_MAX_MSG_LENGTH) {
			/* Received message too big, abort the operation. */
			result = -E2BIG;
			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
				pr_info("Received message too big\n");

			goto continue_op;
		}

		/* Remove the blocknum from the data. */
		len--;
		for (i = 0; i < len; i++)
			ssif_info->data[i + ssif_info->multi_len] = data[i + 1];
		ssif_info->multi_len += len;
		if (blocknum == 0xff) {
			/* End of read */
			len = ssif_info->multi_len;
			data = ssif_info->data;
		} else if (blocknum + 1 != ssif_info->multi_pos) {
			/*
			 * Out of sequence block, just abort.  Block
			 * numbers start at zero for the second block,
			 * but multi_pos starts at one, so the +1.
			 */
			result = -EIO;
		} else {
			ssif_inc_stat(ssif_info, received_message_parts);

			ssif_info->multi_pos++;

			rv = ssif_i2c_send(ssif_info, msg_done_handler,
					   I2C_SMBUS_READ,
					   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
					   ssif_info->recv,
					   I2C_SMBUS_BLOCK_DATA);
			if (rv < 0) {
				if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
					pr_info(PFX
						"Error from ssif_i2c_send\n");

				result = -EIO;
			} else
				return;
		}
	}

	if (result < 0) {
		ssif_inc_stat(ssif_info, receive_errors);
	} else {
		ssif_inc_stat(ssif_info, received_messages);
		ssif_inc_stat(ssif_info, received_message_parts);
	}


 continue_op:
	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
		pr_info(PFX "DONE 1: state = %d, result=%d.\n",
			ssif_info->ssif_state, result);

	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
	msg = ssif_info->curr_msg;
	if (msg) {
		msg->rsp_size = len;
		if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
			msg->rsp_size = IPMI_MAX_MSG_LENGTH;
		memcpy(msg->rsp, data, msg->rsp_size);
		ssif_info->curr_msg = NULL;
	}

	switch (ssif_info->ssif_state) {
	case SSIF_NORMAL:
		ipmi_ssif_unlock_cond(ssif_info, flags);
		if (!msg)
			break;

		if (result < 0)
			return_hosed_msg(ssif_info, msg);
		else
			deliver_recv_msg(ssif_info, msg);
		break;

	case SSIF_GETTING_FLAGS:
		/* We got the flags from the SSIF, now handle them. */
		if ((result < 0) || (len < 4) || (data[2] != 0)) {
			/*
			 * Error fetching flags, or invalid length,
			 * just give up for now.
			 */
			ssif_info->ssif_state = SSIF_NORMAL;
			ipmi_ssif_unlock_cond(ssif_info, flags);
			pr_warn(PFX "Error getting flags: %d %d, %x\n",
			       result, len, data[2]);
		} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
			   || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
			pr_warn(PFX "Invalid response getting flags: %x %x\n",
				data[0], data[1]);
		} else {
			ssif_inc_stat(ssif_info, flag_fetches);
			ssif_info->msg_flags = data[3];
			handle_flags(ssif_info, flags);
		}
		break;

	case SSIF_CLEARING_FLAGS:
		/* We cleared the flags. */
		if ((result < 0) || (len < 3) || (data[2] != 0)) {
			/* Error clearing flags */
			pr_warn(PFX "Error clearing flags: %d %d, %x\n",
			       result, len, data[2]);
		} else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
			   || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
			pr_warn(PFX "Invalid response clearing flags: %x %x\n",
				data[0], data[1]);
		}
		ssif_info->ssif_state = SSIF_NORMAL;
		ipmi_ssif_unlock_cond(ssif_info, flags);
		break;

	case SSIF_GETTING_EVENTS:
		if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
			/* Error getting event, probably done. */
			msg->done(msg);

			/* Take off the event flag. */
			ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
			handle_flags(ssif_info, flags);
		} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
			   || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
			pr_warn(PFX "Invalid response getting events: %x %x\n",
				msg->rsp[0], msg->rsp[1]);
			msg->done(msg);
			/* Take off the event flag. */
			ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
			handle_flags(ssif_info, flags);
		} else {
			handle_flags(ssif_info, flags);
			ssif_inc_stat(ssif_info, events);
			deliver_recv_msg(ssif_info, msg);
		}
		break;

	case SSIF_GETTING_MESSAGES:
		if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
			/* Error getting event, probably done. */
			msg->done(msg);

			/* Take off the msg flag. */
			ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
			handle_flags(ssif_info, flags);
		} else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
			   || msg->rsp[1] != IPMI_GET_MSG_CMD) {
			pr_warn(PFX "Invalid response clearing flags: %x %x\n",
				msg->rsp[0], msg->rsp[1]);
			msg->done(msg);

			/* Take off the msg flag. */
			ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
			handle_flags(ssif_info, flags);
		} else {
			ssif_inc_stat(ssif_info, incoming_messages);
			handle_flags(ssif_info, flags);
			deliver_recv_msg(ssif_info, msg);
		}
		break;
	}

	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
	if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
		if (ssif_info->req_events)
			start_event_fetch(ssif_info, flags);
		else if (ssif_info->req_flags)
			start_flag_fetch(ssif_info, flags);
		else
			start_next_msg(ssif_info, flags);
	} else
		ipmi_ssif_unlock_cond(ssif_info, flags);

	if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
		pr_info(PFX "DONE 2: state = %d.\n", ssif_info->ssif_state);
}

static void msg_written_handler(struct ssif_info *ssif_info, int result,
				unsigned char *data, unsigned int len)
{
	int rv;

	/* We are single-threaded here, so no need for a lock. */
	if (result < 0) {
		ssif_info->retries_left--;
		if (ssif_info->retries_left > 0) {
			if (!start_resend(ssif_info)) {
				ssif_inc_stat(ssif_info, send_retries);
				return;
			}
			/* request failed, just return the error. */
			ssif_inc_stat(ssif_info, send_errors);

			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
				pr_info(PFX
					"Out of retries in msg_written_handler\n");
			msg_done_handler(ssif_info, -EIO, NULL, 0);
			return;
		}

		ssif_inc_stat(ssif_info, send_errors);

		/*
		 * Got an error on transmit, let the done routine
		 * handle it.
		 */
		if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
			pr_info("Error in msg_written_handler: %d\n", result);

		msg_done_handler(ssif_info, result, NULL, 0);
		return;
	}

	if (ssif_info->multi_data) {
		/*
		 * In the middle of a multi-data write.  See the comment
		 * in the SSIF_MULTI_n_PART case in the probe function
		 * for details on the intricacies of this.
		 */
		int left;
		unsigned char *data_to_send;

		ssif_inc_stat(ssif_info, sent_messages_parts);

		left = ssif_info->multi_len - ssif_info->multi_pos;
		if (left > 32)
			left = 32;
		/* Length byte. */
		ssif_info->multi_data[ssif_info->multi_pos] = left;
		data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
		ssif_info->multi_pos += left;
		if (left < 32)
			/*
			 * Write is finished.  Note that we must end
			 * with a write of less than 32 bytes to
			 * complete the transaction, even if it is
			 * zero bytes.
			 */
			ssif_info->multi_data = NULL;

		rv = ssif_i2c_send(ssif_info, msg_written_handler,
				  I2C_SMBUS_WRITE,
				  SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
				  data_to_send,
				  I2C_SMBUS_BLOCK_DATA);
		if (rv < 0) {
			/* request failed, just return the error. */
			ssif_inc_stat(ssif_info, send_errors);

			if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
				pr_info("Error from i2c_non_blocking_op(3)\n");
			msg_done_handler(ssif_info, -EIO, NULL, 0);
		}
	} else {
		/* Ready to request the result. */
		unsigned long oflags, *flags;

		ssif_inc_stat(ssif_info, sent_messages);
		ssif_inc_stat(ssif_info, sent_messages_parts);

		flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
		if (ssif_info->got_alert) {
			/* The result is already ready, just start it. */
			ssif_info->got_alert = false;
			ipmi_ssif_unlock_cond(ssif_info, flags);
			start_get(ssif_info);
		} else {
			/* Wait a jiffie then request the next message */
			ssif_info->waiting_alert = true;
			ssif_info->retries_left = SSIF_RECV_RETRIES;
			ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
			mod_timer(&ssif_info->retry_timer,
				  jiffies + SSIF_MSG_PART_JIFFIES);
			ipmi_ssif_unlock_cond(ssif_info, flags);
		}
	}
}

static int start_resend(struct ssif_info *ssif_info)
{
	int rv;
	int command;

	ssif_info->got_alert = false;

	if (ssif_info->data_len > 32) {
		command = SSIF_IPMI_MULTI_PART_REQUEST_START;
		ssif_info->multi_data = ssif_info->data;
		ssif_info->multi_len = ssif_info->data_len;
		/*
		 * Subtle thing, this is 32, not 33, because we will
		 * overwrite the thing at position 32 (which was just
		 * transmitted) with the new length.
		 */
		ssif_info->multi_pos = 32;
		ssif_info->data[0] = 32;
	} else {
		ssif_info->multi_data = NULL;
		command = SSIF_IPMI_REQUEST;
		ssif_info->data[0] = ssif_info->data_len;
	}

	rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
			  command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
	if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
		pr_info("Error from i2c_non_blocking_op(4)\n");
	return rv;
}

static int start_send(struct ssif_info *ssif_info,
		      unsigned char   *data,
		      unsigned int    len)
{
	if (len > IPMI_MAX_MSG_LENGTH)
		return -E2BIG;
	if (len > ssif_info->max_xmit_msg_size)
		return -E2BIG;

	ssif_info->retries_left = SSIF_SEND_RETRIES;
	memcpy(ssif_info->data + 1, data, len);
	ssif_info->data_len = len;
	return start_resend(ssif_info);
}

/* Must be called with the message lock held. */
static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
{
	struct ipmi_smi_msg *msg;
	unsigned long oflags;

 restart:
	if (!SSIF_IDLE(ssif_info)) {
		ipmi_ssif_unlock_cond(ssif_info, flags);
		return;
	}

	if (!ssif_info->waiting_msg) {
		ssif_info->curr_msg = NULL;
		ipmi_ssif_unlock_cond(ssif_info, flags);
	} else {
		int rv;

		ssif_info->curr_msg = ssif_info->waiting_msg;
		ssif_info->waiting_msg = NULL;
		ipmi_ssif_unlock_cond(ssif_info, flags);
		rv = start_send(ssif_info,
				ssif_info->curr_msg->data,
				ssif_info->curr_msg->data_size);
		if (rv) {
			msg = ssif_info->curr_msg;
			ssif_info->curr_msg = NULL;
			return_hosed_msg(ssif_info, msg);
			flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
			goto restart;
		}
	}
}

static void sender(void                *send_info,
		   struct ipmi_smi_msg *msg)
{
	struct ssif_info *ssif_info = (struct ssif_info *) send_info;
	unsigned long oflags, *flags;

	BUG_ON(ssif_info->waiting_msg);
	ssif_info->waiting_msg = msg;

	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
	start_next_msg(ssif_info, flags);

	if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
		struct timespec64 t;

		ktime_get_real_ts64(&t);
		pr_info("**Enqueue %02x %02x: %lld.%6.6ld\n",
		       msg->data[0], msg->data[1],
		       (long long) t.tv_sec, (long) t.tv_nsec / NSEC_PER_USEC);
	}
}

static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
{
	struct ssif_info *ssif_info = send_info;

	data->addr_src = ssif_info->addr_source;
	data->dev = &ssif_info->client->dev;
	data->addr_info = ssif_info->addr_info;
	get_device(data->dev);

	return 0;
}

/*
 * Instead of having our own timer to periodically check the message
 * flags, we let the message handler drive us.
 */
static void request_events(void *send_info)
{
	struct ssif_info *ssif_info = (struct ssif_info *) send_info;
	unsigned long oflags, *flags;

	if (!ssif_info->has_event_buffer)
		return;

	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
	/*
	 * Request flags first, not events, because the lower layer
	 * doesn't have a way to send an attention.  But make sure
	 * event checking still happens.
	 */
	ssif_info->req_events = true;
	if (SSIF_IDLE(ssif_info))
		start_flag_fetch(ssif_info, flags);
	else {
		ssif_info->req_flags = true;
		ipmi_ssif_unlock_cond(ssif_info, flags);
	}
}

static int inc_usecount(void *send_info)
{
	struct ssif_info *ssif_info = send_info;

	if (!i2c_get_adapter(ssif_info->client->adapter->nr))
		return -ENODEV;

	i2c_use_client(ssif_info->client);
	return 0;
}

static void dec_usecount(void *send_info)
{
	struct ssif_info *ssif_info = send_info;

	i2c_release_client(ssif_info->client);
	i2c_put_adapter(ssif_info->client->adapter);
}

static int ssif_start_processing(void *send_info,
				 ipmi_smi_t intf)
{
	struct ssif_info *ssif_info = send_info;

	ssif_info->intf = intf;

	return 0;
}

#define MAX_SSIF_BMCS 4

static unsigned short addr[MAX_SSIF_BMCS];
static int num_addrs;
module_param_array(addr, ushort, &num_addrs, 0);
MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");

static char *adapter_name[MAX_SSIF_BMCS];
static int num_adapter_names;
module_param_array(adapter_name, charp, &num_adapter_names, 0);
MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");

static int slave_addrs[MAX_SSIF_BMCS];
static int num_slave_addrs;
module_param_array(slave_addrs, int, &num_slave_addrs, 0);
MODULE_PARM_DESC(slave_addrs,
		 "The default IPMB slave address for the controller.");

static bool alerts_broken;
module_param(alerts_broken, bool, 0);
MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");

/*
 * Bit 0 enables message debugging, bit 1 enables state debugging, and
 * bit 2 enables timing debugging.  This is an array indexed by
 * interface number"
 */
static int dbg[MAX_SSIF_BMCS];
static int num_dbg;
module_param_array(dbg, int, &num_dbg, 0);
MODULE_PARM_DESC(dbg, "Turn on debugging.");

static bool ssif_dbg_probe;
module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");

static bool ssif_tryacpi = true;
module_param_named(tryacpi, ssif_tryacpi, bool, 0);
MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");

static bool ssif_trydmi = true;
module_param_named(trydmi, ssif_trydmi, bool, 0);
MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");

static DEFINE_MUTEX(ssif_infos_mutex);
static LIST_HEAD(ssif_infos);

static int ssif_remove(struct i2c_client *client)
{
	struct ssif_info *ssif_info = i2c_get_clientdata(client);
	int rv;

	if (!ssif_info)
		return 0;

	/*
	 * After this point, we won't deliver anything asychronously
	 * to the message handler.  We can unregister ourself.
	 */
	rv = ipmi_unregister_smi(ssif_info->intf);
	if (rv) {
		pr_err(PFX "Unable to unregister device: errno=%d\n", rv);
		return rv;
	}
	ssif_info->intf = NULL;

	/* make sure the driver is not looking for flags any more. */
	while (ssif_info->ssif_state != SSIF_NORMAL)
		schedule_timeout(1);

	ssif_info->stopping = true;
	del_timer_sync(&ssif_info->retry_timer);
	if (ssif_info->thread) {
		complete(&ssif_info->wake_thread);
		kthread_stop(ssif_info->thread);
	}

	/*
	 * No message can be outstanding now, we have removed the
	 * upper layer and it permitted us to do so.
	 */
	kfree(ssif_info);
	return 0;
}

static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
		  int *resp_len, unsigned char *resp)
{
	int retry_cnt;
	int ret;

	retry_cnt = SSIF_SEND_RETRIES;
 retry1:
	ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
	if (ret) {
		retry_cnt--;
		if (retry_cnt > 0)
			goto retry1;
		return -ENODEV;
	}

	ret = -ENODEV;
	retry_cnt = SSIF_RECV_RETRIES;
	while (retry_cnt > 0) {
		ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
						resp);
		if (ret > 0)
			break;
		msleep(SSIF_MSG_MSEC);
		retry_cnt--;
		if (retry_cnt <= 0)
			break;
	}

	if (ret > 0) {
		/* Validate that the response is correct. */
		if (ret < 3 ||
		    (resp[0] != (msg[0] | (1 << 2))) ||
		    (resp[1] != msg[1]))
			ret = -EINVAL;
		else {
			*resp_len = ret;
			ret = 0;
		}
	}

	return ret;
}

static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
{
	unsigned char *resp;
	unsigned char msg[3];
	int           rv;
	int           len;

	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
	if (!resp)
		return -ENOMEM;

	/* Do a Get Device ID command, since it is required. */
	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_GET_DEVICE_ID_CMD;
	rv = do_cmd(client, 2, msg, &len, resp);
	if (rv)
		rv = -ENODEV;
	else
		strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
	kfree(resp);
	return rv;
}

static int smi_type_proc_show(struct seq_file *m, void *v)
{
	seq_puts(m, "ssif\n");

	return 0;
}

static int smi_type_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, smi_type_proc_show, inode->i_private);
}

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

static int smi_stats_proc_show(struct seq_file *m, void *v)
{
	struct ssif_info *ssif_info = m->private;

	seq_printf(m, "sent_messages:          %u\n",
		   ssif_get_stat(ssif_info, sent_messages));
	seq_printf(m, "sent_messages_parts:    %u\n",
		   ssif_get_stat(ssif_info, sent_messages_parts));
	seq_printf(m, "send_retries:           %u\n",
		   ssif_get_stat(ssif_info, send_retries));
	seq_printf(m, "send_errors:            %u\n",
		   ssif_get_stat(ssif_info, send_errors));
	seq_printf(m, "received_messages:      %u\n",
		   ssif_get_stat(ssif_info, received_messages));
	seq_printf(m, "received_message_parts: %u\n",
		   ssif_get_stat(ssif_info, received_message_parts));
	seq_printf(m, "receive_retries:        %u\n",
		   ssif_get_stat(ssif_info, receive_retries));
	seq_printf(m, "receive_errors:         %u\n",
		   ssif_get_stat(ssif_info, receive_errors));
	seq_printf(m, "flag_fetches:           %u\n",
		   ssif_get_stat(ssif_info, flag_fetches));
	seq_printf(m, "hosed:                  %u\n",
		   ssif_get_stat(ssif_info, hosed));
	seq_printf(m, "events:                 %u\n",
		   ssif_get_stat(ssif_info, events));
	seq_printf(m, "watchdog_pretimeouts:   %u\n",
		   ssif_get_stat(ssif_info, watchdog_pretimeouts));
	seq_printf(m, "alerts:                 %u\n",
		   ssif_get_stat(ssif_info, alerts));
	return 0;
}

static int smi_stats_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
}

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

static int strcmp_nospace(char *s1, char *s2)
{
	while (*s1 && *s2) {
		while (isspace(*s1))
			s1++;
		while (isspace(*s2))
			s2++;
		if (*s1 > *s2)
			return 1;
		if (*s1 < *s2)
			return -1;
		s1++;
		s2++;
	}
	return 0;
}

static struct ssif_addr_info *ssif_info_find(unsigned short addr,
					     char *adapter_name,
					     bool match_null_name)
{
	struct ssif_addr_info *info, *found = NULL;

restart:
	list_for_each_entry(info, &ssif_infos, link) {
		if (info->binfo.addr == addr) {
			if (info->adapter_name || adapter_name) {
				if (!info->adapter_name != !adapter_name) {
					/* One is NULL and one is not */
					continue;
				}
				if (adapter_name &&
				    strcmp_nospace(info->adapter_name,
						   adapter_name))
					/* Names do not match */
					continue;
			}
			found = info;
			break;
		}
	}

	if (!found && match_null_name) {
		/* Try to get an exact match first, then try with a NULL name */
		adapter_name = NULL;
		match_null_name = false;
		goto restart;
	}

	return found;
}

static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
{
#ifdef CONFIG_ACPI
	acpi_handle acpi_handle;

	acpi_handle = ACPI_HANDLE(dev);
	if (acpi_handle) {
		ssif_info->addr_source = SI_ACPI;
		ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
		return true;
	}
#endif
	return false;
}

static int find_slave_address(struct i2c_client *client, int slave_addr)
{
	struct ssif_addr_info *info;

	if (slave_addr)
		return slave_addr;

	/*
	 * Came in without a slave address, search around to see if
	 * the other sources have a slave address.  This lets us pick
	 * up an SMBIOS slave address when using ACPI.
	 */
	list_for_each_entry(info, &ssif_infos, link) {
		if (info->binfo.addr != client->addr)
			continue;
		if (info->adapter_name && client->adapter->name &&
		    strcmp_nospace(info->adapter_name,
				   client->adapter->name))
			continue;
		if (info->slave_addr) {
			slave_addr = info->slave_addr;
			break;
		}
	}

	return slave_addr;
}

/*
 * Global enables we care about.
 */
#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
			     IPMI_BMC_EVT_MSG_INTR)

static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	unsigned char     msg[3];
	unsigned char     *resp;
	struct ssif_info   *ssif_info;
	int               rv = 0;
	int               len;
	int               i;
	u8		  slave_addr = 0;
	struct ssif_addr_info *addr_info = NULL;


	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
	if (!resp)
		return -ENOMEM;

	ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
	if (!ssif_info) {
		kfree(resp);
		return -ENOMEM;
	}

	if (!check_acpi(ssif_info, &client->dev)) {
		addr_info = ssif_info_find(client->addr, client->adapter->name,
					   true);
		if (!addr_info) {
			/* Must have come in through sysfs. */
			ssif_info->addr_source = SI_HOTMOD;
		} else {
			ssif_info->addr_source = addr_info->addr_src;
			ssif_info->ssif_debug = addr_info->debug;
			ssif_info->addr_info = addr_info->addr_info;
			slave_addr = addr_info->slave_addr;
		}
	}

	slave_addr = find_slave_address(client, slave_addr);

	pr_info(PFX "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
	       ipmi_addr_src_to_str(ssif_info->addr_source),
	       client->addr, client->adapter->name, slave_addr);

	/*
	 * Do a Get Device ID command, since it comes back with some
	 * useful info.
	 */
	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_GET_DEVICE_ID_CMD;
	rv = do_cmd(client, 2, msg, &len, resp);
	if (rv)
		goto out;

	rv = ipmi_demangle_device_id(resp, len, &ssif_info->device_id);
	if (rv)
		goto out;

	ssif_info->client = client;
	i2c_set_clientdata(client, ssif_info);

	/* Now check for system interface capabilities */
	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
	msg[2] = 0; /* SSIF */
	rv = do_cmd(client, 3, msg, &len, resp);
	if (!rv && (len >= 3) && (resp[2] == 0)) {
		if (len < 7) {
			if (ssif_dbg_probe)
				pr_info(PFX "SSIF info too short: %d\n", len);
			goto no_support;
		}

		/* Got a good SSIF response, handle it. */
		ssif_info->max_xmit_msg_size = resp[5];
		ssif_info->max_recv_msg_size = resp[6];
		ssif_info->multi_support = (resp[4] >> 6) & 0x3;
		ssif_info->supports_pec = (resp[4] >> 3) & 0x1;

		/* Sanitize the data */
		switch (ssif_info->multi_support) {
		case SSIF_NO_MULTI:
			if (ssif_info->max_xmit_msg_size > 32)
				ssif_info->max_xmit_msg_size = 32;
			if (ssif_info->max_recv_msg_size > 32)
				ssif_info->max_recv_msg_size = 32;
			break;

		case SSIF_MULTI_2_PART:
			if (ssif_info->max_xmit_msg_size > 63)
				ssif_info->max_xmit_msg_size = 63;
			if (ssif_info->max_recv_msg_size > 62)
				ssif_info->max_recv_msg_size = 62;
			break;

		case SSIF_MULTI_n_PART:
			/*
			 * The specification is rather confusing at
			 * this point, but I think I understand what
			 * is meant.  At least I have a workable
			 * solution.  With multi-part messages, you
			 * cannot send a message that is a multiple of
			 * 32-bytes in length, because the start and
			 * middle messages are 32-bytes and the end
			 * message must be at least one byte.  You
			 * can't fudge on an extra byte, that would
			 * screw up things like fru data writes.  So
			 * we limit the length to 63 bytes.  That way
			 * a 32-byte message gets sent as a single
			 * part.  A larger message will be a 32-byte
			 * start and the next message is always going
			 * to be 1-31 bytes in length.  Not ideal, but
			 * it should work.
			 */
			if (ssif_info->max_xmit_msg_size > 63)
				ssif_info->max_xmit_msg_size = 63;
			break;

		default:
			/* Data is not sane, just give up. */
			goto no_support;
		}
	} else {
 no_support:
		/* Assume no multi-part or PEC support */
		pr_info(PFX "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
		       rv, len, resp[2]);

		ssif_info->max_xmit_msg_size = 32;
		ssif_info->max_recv_msg_size = 32;
		ssif_info->multi_support = SSIF_NO_MULTI;
		ssif_info->supports_pec = 0;
	}

	/* Make sure the NMI timeout is cleared. */
	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
	msg[2] = WDT_PRE_TIMEOUT_INT;
	rv = do_cmd(client, 3, msg, &len, resp);
	if (rv || (len < 3) || (resp[2] != 0))
		pr_warn(PFX "Unable to clear message flags: %d %d %2.2x\n",
			rv, len, resp[2]);

	/* Attempt to enable the event buffer. */
	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
	rv = do_cmd(client, 2, msg, &len, resp);
	if (rv || (len < 4) || (resp[2] != 0)) {
		pr_warn(PFX "Error getting global enables: %d %d %2.2x\n",
			rv, len, resp[2]);
		rv = 0; /* Not fatal */
		goto found;
	}

	ssif_info->global_enables = resp[3];

	if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
		ssif_info->has_event_buffer = true;
		/* buffer is already enabled, nothing to do. */
		goto found;
	}

	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
	msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
	rv = do_cmd(client, 3, msg, &len, resp);
	if (rv || (len < 2)) {
		pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
			rv, len, resp[2]);
		rv = 0; /* Not fatal */
		goto found;
	}

	if (resp[2] == 0) {
		/* A successful return means the event buffer is supported. */
		ssif_info->has_event_buffer = true;
		ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
	}

	/* Some systems don't behave well if you enable alerts. */
	if (alerts_broken)
		goto found;

	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
	msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
	msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
	rv = do_cmd(client, 3, msg, &len, resp);
	if (rv || (len < 2)) {
		pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
			rv, len, resp[2]);
		rv = 0; /* Not fatal */
		goto found;
	}

	if (resp[2] == 0) {
		/* A successful return means the alert is supported. */
		ssif_info->supports_alert = true;
		ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
	}

 found:
	ssif_info->intf_num = atomic_inc_return(&next_intf);

	if (ssif_dbg_probe) {
		pr_info("ssif_probe: i2c_probe found device at i2c address %x\n",
			client->addr);
	}

	spin_lock_init(&ssif_info->lock);
	ssif_info->ssif_state = SSIF_NORMAL;
	setup_timer(&ssif_info->retry_timer, retry_timeout,
		    (unsigned long)ssif_info);

	for (i = 0; i < SSIF_NUM_STATS; i++)
		atomic_set(&ssif_info->stats[i], 0);

	if (ssif_info->supports_pec)
		ssif_info->client->flags |= I2C_CLIENT_PEC;

	ssif_info->handlers.owner = THIS_MODULE;
	ssif_info->handlers.start_processing = ssif_start_processing;
	ssif_info->handlers.get_smi_info = get_smi_info;
	ssif_info->handlers.sender = sender;
	ssif_info->handlers.request_events = request_events;
	ssif_info->handlers.inc_usecount = inc_usecount;
	ssif_info->handlers.dec_usecount = dec_usecount;

	{
		unsigned int thread_num;

		thread_num = ((ssif_info->client->adapter->nr << 8) |
			      ssif_info->client->addr);
		init_completion(&ssif_info->wake_thread);
		ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
					       "kssif%4.4x", thread_num);
		if (IS_ERR(ssif_info->thread)) {
			rv = PTR_ERR(ssif_info->thread);
			dev_notice(&ssif_info->client->dev,
				   "Could not start kernel thread: error %d\n",
				   rv);
			goto out;
		}
	}

	rv = ipmi_register_smi(&ssif_info->handlers,
			       ssif_info,
			       &ssif_info->device_id,
			       &ssif_info->client->dev,
			       slave_addr);
	 if (rv) {
		pr_err(PFX "Unable to register device: error %d\n", rv);
		goto out;
	}

	rv = ipmi_smi_add_proc_entry(ssif_info->intf, "type",
				     &smi_type_proc_ops,
				     ssif_info);
	if (rv) {
		pr_err(PFX "Unable to create proc entry: %d\n", rv);
		goto out_err_unreg;
	}

	rv = ipmi_smi_add_proc_entry(ssif_info->intf, "ssif_stats",
				     &smi_stats_proc_ops,
				     ssif_info);
	if (rv) {
		pr_err(PFX "Unable to create proc entry: %d\n", rv);
		goto out_err_unreg;
	}

 out:
	if (rv)
		kfree(ssif_info);
	kfree(resp);
	return rv;

 out_err_unreg:
	ipmi_unregister_smi(ssif_info->intf);
	goto out;
}

static int ssif_adapter_handler(struct device *adev, void *opaque)
{
	struct ssif_addr_info *addr_info = opaque;

	if (adev->type != &i2c_adapter_type)
		return 0;

	i2c_new_device(to_i2c_adapter(adev), &addr_info->binfo);

	if (!addr_info->adapter_name)
		return 1; /* Only try the first I2C adapter by default. */
	return 0;
}

static int new_ssif_client(int addr, char *adapter_name,
			   int debug, int slave_addr,
			   enum ipmi_addr_src addr_src)
{
	struct ssif_addr_info *addr_info;
	int rv = 0;

	mutex_lock(&ssif_infos_mutex);
	if (ssif_info_find(addr, adapter_name, false)) {
		rv = -EEXIST;
		goto out_unlock;
	}

	addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
	if (!addr_info) {
		rv = -ENOMEM;
		goto out_unlock;
	}

	if (adapter_name) {
		addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
		if (!addr_info->adapter_name) {
			kfree(addr_info);
			rv = -ENOMEM;
			goto out_unlock;
		}
	}

	strncpy(addr_info->binfo.type, DEVICE_NAME,
		sizeof(addr_info->binfo.type));
	addr_info->binfo.addr = addr;
	addr_info->binfo.platform_data = addr_info;
	addr_info->debug = debug;
	addr_info->slave_addr = slave_addr;
	addr_info->addr_src = addr_src;

	list_add_tail(&addr_info->link, &ssif_infos);

	if (initialized)
		i2c_for_each_dev(addr_info, ssif_adapter_handler);
	/* Otherwise address list will get it */

out_unlock:
	mutex_unlock(&ssif_infos_mutex);
	return rv;
}

static void free_ssif_clients(void)
{
	struct ssif_addr_info *info, *tmp;

	mutex_lock(&ssif_infos_mutex);
	list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
		list_del(&info->link);
		kfree(info->adapter_name);
		kfree(info);
	}
	mutex_unlock(&ssif_infos_mutex);
}

static unsigned short *ssif_address_list(void)
{
	struct ssif_addr_info *info;
	unsigned int count = 0, i;
	unsigned short *address_list;

	list_for_each_entry(info, &ssif_infos, link)
		count++;

	address_list = kzalloc(sizeof(*address_list) * (count + 1), GFP_KERNEL);
	if (!address_list)
		return NULL;

	i = 0;
	list_for_each_entry(info, &ssif_infos, link) {
		unsigned short addr = info->binfo.addr;
		int j;

		for (j = 0; j < i; j++) {
			if (address_list[j] == addr)
				goto skip_addr;
		}
		address_list[i] = addr;
skip_addr:
		i++;
	}
	address_list[i] = I2C_CLIENT_END;

	return address_list;
}

#ifdef CONFIG_ACPI
static const struct acpi_device_id ssif_acpi_match[] = {
	{ "IPI0001", 0 },
	{ },
};
MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);

/*
 * Once we get an ACPI failure, we don't try any more, because we go
 * through the tables sequentially.  Once we don't find a table, there
 * are no more.
 */
static int acpi_failure;

/*
 * Defined in the IPMI 2.0 spec.
 */
struct SPMITable {
	s8	Signature[4];
	u32	Length;
	u8	Revision;
	u8	Checksum;
	s8	OEMID[6];
	s8	OEMTableID[8];
	s8	OEMRevision[4];
	s8	CreatorID[4];
	s8	CreatorRevision[4];
	u8	InterfaceType;
	u8	IPMIlegacy;
	s16	SpecificationRevision;

	/*
	 * Bit 0 - SCI interrupt supported
	 * Bit 1 - I/O APIC/SAPIC
	 */
	u8	InterruptType;

	/*
	 * If bit 0 of InterruptType is set, then this is the SCI
	 * interrupt in the GPEx_STS register.
	 */
	u8	GPE;

	s16	Reserved;

	/*
	 * If bit 1 of InterruptType is set, then this is the I/O
	 * APIC/SAPIC interrupt.
	 */
	u32	GlobalSystemInterrupt;

	/* The actual register address. */
	struct acpi_generic_address addr;

	u8	UID[4];

	s8      spmi_id[1]; /* A '\0' terminated array starts here. */
};

static int try_init_spmi(struct SPMITable *spmi)
{
	unsigned short myaddr;

	if (num_addrs >= MAX_SSIF_BMCS)
		return -1;

	if (spmi->IPMIlegacy != 1) {
		pr_warn("IPMI: Bad SPMI legacy: %d\n", spmi->IPMIlegacy);
		return -ENODEV;
	}

	if (spmi->InterfaceType != 4)
		return -ENODEV;

	if (spmi->addr.space_id != ACPI_ADR_SPACE_SMBUS) {
		pr_warn(PFX "Invalid ACPI SSIF I/O Address type: %d\n",
			spmi->addr.space_id);
		return -EIO;
	}

	myaddr = spmi->addr.address & 0x7f;

	return new_ssif_client(myaddr, NULL, 0, 0, SI_SPMI);
}

static void spmi_find_bmc(void)
{
	acpi_status      status;
	struct SPMITable *spmi;
	int              i;

	if (acpi_disabled)
		return;

	if (acpi_failure)
		return;

	for (i = 0; ; i++) {
		status = acpi_get_table(ACPI_SIG_SPMI, i+1,
					(struct acpi_table_header **)&spmi);
		if (status != AE_OK)
			return;

		try_init_spmi(spmi);
	}
}
#else
static void spmi_find_bmc(void) { }
#endif

#ifdef CONFIG_DMI
static int decode_dmi(const struct dmi_device *dmi_dev)
{
	struct dmi_header *dm = dmi_dev->device_data;
	u8             *data = (u8 *) dm;
	u8             len = dm->length;
	unsigned short myaddr;
	int            slave_addr;

	if (num_addrs >= MAX_SSIF_BMCS)
		return -1;

	if (len < 9)
		return -1;

	if (data[0x04] != 4) /* Not SSIF */
		return -1;

	if ((data[8] >> 1) == 0) {
		/*
		 * Some broken systems put the I2C address in
		 * the slave address field.  We try to
		 * accommodate them here.
		 */
		myaddr = data[6] >> 1;
		slave_addr = 0;
	} else {
		myaddr = data[8] >> 1;
		slave_addr = data[6];
	}

	return new_ssif_client(myaddr, NULL, 0, slave_addr, SI_SMBIOS);
}

static void dmi_iterator(void)
{
	const struct dmi_device *dev = NULL;

	while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
		decode_dmi(dev);
}
#else
static void dmi_iterator(void) { }
#endif

static const struct i2c_device_id ssif_id[] = {
	{ DEVICE_NAME, 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ssif_id);

static struct i2c_driver ssif_i2c_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver		= {
		.name			= DEVICE_NAME
	},
	.probe		= ssif_probe,
	.remove		= ssif_remove,
	.alert		= ssif_alert,
	.id_table	= ssif_id,
	.detect		= ssif_detect
};

static int init_ipmi_ssif(void)
{
	int i;
	int rv;

	if (initialized)
		return 0;

	pr_info("IPMI SSIF Interface driver\n");

	/* build list for i2c from addr list */
	for (i = 0; i < num_addrs; i++) {
		rv = new_ssif_client(addr[i], adapter_name[i],
				     dbg[i], slave_addrs[i],
				     SI_HARDCODED);
		if (rv)
			pr_err(PFX
			       "Couldn't add hardcoded device at addr 0x%x\n",
			       addr[i]);
	}

	if (ssif_tryacpi)
		ssif_i2c_driver.driver.acpi_match_table	=
			ACPI_PTR(ssif_acpi_match);
	if (ssif_trydmi)
		dmi_iterator();
	if (ssif_tryacpi)
		spmi_find_bmc();

	ssif_i2c_driver.address_list = ssif_address_list();

	rv = i2c_add_driver(&ssif_i2c_driver);
	if (!rv)
		initialized = true;

	return rv;
}
module_init(init_ipmi_ssif);

static void cleanup_ipmi_ssif(void)
{
	if (!initialized)
		return;

	initialized = false;

	i2c_del_driver(&ssif_i2c_driver);

	free_ssif_clients();
}
module_exit(cleanup_ipmi_ssif);

MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
MODULE_LICENSE("GPL");