aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/files/crypto/ocf/crypto.c
blob: 9735f0ce93baf5b7f0f42162406e1802c3a029f1 (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
/*-
 * Linux port done by David McCullough <david_mccullough@mcafee.com>
 * Copyright (C) 2006-2010 David McCullough
 * Copyright (C) 2004-2005 Intel Corporation.
 * The license and original author are listed below.
 *
 * Redistribution and use in source and binary forms, with or without
 * Copyright (c) 2002-2006 Sam Leffler.  All rights reserved.
 *
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#if 0
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/opencrypto/crypto.c,v 1.27 2007/03/21 03:42:51 sam Exp $");
#endif

/*
 * Cryptographic Subsystem.
 *
 * This code is derived from the Openbsd Cryptographic Framework (OCF)
 * that has the copyright shown below.  Very little of the original
 * code remains.
 */
/*-
 * The author of this code is Angelos D. Keromytis (angelos@cis.upenn.edu)
 *
 * This code was written by Angelos D. Keromytis in Athens, Greece, in
 * February 2000. Network Security Technologies Inc. (NSTI) kindly
 * supported the development of this code.
 *
 * Copyright (c) 2000, 2001 Angelos D. Keromytis
 *
 * Permission to use, copy, and modify this software with or without fee
 * is hereby granted, provided that this entire notice is included in
 * all source code copies of any software which is or includes a copy or
 * modification of this software.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 *
__FBSDID("$FreeBSD: src/sys/opencrypto/crypto.c,v 1.16 2005/01/07 02:29:16 imp Exp $");
 */


#ifndef AUTOCONF_INCLUDED
#include <linux/config.h>
#endif
#include <linux/module.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/version.h>
#include <cryptodev.h>

/*
 * keep track of whether or not we have been initialised, a big
 * issue if we are linked into the kernel and a driver gets started before
 * us
 */
static int crypto_initted = 0;

/*
 * Crypto drivers register themselves by allocating a slot in the
 * crypto_drivers table with crypto_get_driverid() and then registering
 * each algorithm they support with crypto_register() and crypto_kregister().
 */

/*
 * lock on driver table
 * we track its state as spin_is_locked does not do anything on non-SMP boxes
 */
static spinlock_t	crypto_drivers_lock;
static int			crypto_drivers_locked;		/* for non-SMP boxes */

#define	CRYPTO_DRIVER_LOCK() \
			({ \
				spin_lock_irqsave(&crypto_drivers_lock, d_flags); \
			 	crypto_drivers_locked = 1; \
				dprintk("%s,%d: DRIVER_LOCK()\n", __FILE__, __LINE__); \
			 })
#define	CRYPTO_DRIVER_UNLOCK() \
			({ \
			 	dprintk("%s,%d: DRIVER_UNLOCK()\n", __FILE__, __LINE__); \
			 	crypto_drivers_locked = 0; \
				spin_unlock_irqrestore(&crypto_drivers_lock, d_flags); \
			 })
#define	CRYPTO_DRIVER_ASSERT() \
			({ \
			 	if (!crypto_drivers_locked) { \
					dprintk("%s,%d: DRIVER_ASSERT!\n", __FILE__, __LINE__); \
			 	} \
			 })

/*
 * Crypto device/driver capabilities structure.
 *
 * Synchronization:
 * (d) - protected by CRYPTO_DRIVER_LOCK()
 * (q) - protected by CRYPTO_Q_LOCK()
 * Not tagged fields are read-only.
 */
struct cryptocap {
	device_t	cc_dev;			/* (d) device/driver */
	u_int32_t	cc_sessions;		/* (d) # of sessions */
	u_int32_t	cc_koperations;		/* (d) # os asym operations */
	/*
	 * Largest possible operator length (in bits) for each type of
	 * encryption algorithm. XXX not used
	 */
	u_int16_t	cc_max_op_len[CRYPTO_ALGORITHM_MAX + 1];
	u_int8_t	cc_alg[CRYPTO_ALGORITHM_MAX + 1];
	u_int8_t	cc_kalg[CRK_ALGORITHM_MAX + 1];

	int		cc_flags;		/* (d) flags */
#define CRYPTOCAP_F_CLEANUP	0x80000000	/* needs resource cleanup */
	int		cc_qblocked;		/* (q) symmetric q blocked */
	int		cc_kqblocked;		/* (q) asymmetric q blocked */

	int		cc_unqblocked;		/* (q) symmetric q blocked */
	int		cc_unkqblocked;		/* (q) asymmetric q blocked */
};
static struct cryptocap *crypto_drivers = NULL;
static int crypto_drivers_num = 0;

/*
 * There are two queues for crypto requests; one for symmetric (e.g.
 * cipher) operations and one for asymmetric (e.g. MOD)operations.
 * A single mutex is used to lock access to both queues.  We could
 * have one per-queue but having one simplifies handling of block/unblock
 * operations.
 */
static	int crp_sleep = 0;
static LIST_HEAD(crp_q);		/* request queues */
static LIST_HEAD(crp_kq);

static spinlock_t crypto_q_lock;

int crypto_all_qblocked = 0;  /* protect with Q_LOCK */
module_param(crypto_all_qblocked, int, 0444);
MODULE_PARM_DESC(crypto_all_qblocked, "Are all crypto queues blocked");

int crypto_all_kqblocked = 0; /* protect with Q_LOCK */
module_param(crypto_all_kqblocked, int, 0444);
MODULE_PARM_DESC(crypto_all_kqblocked, "Are all asym crypto queues blocked");

#define	CRYPTO_Q_LOCK() \
			({ \
				spin_lock_irqsave(&crypto_q_lock, q_flags); \
			 	dprintk("%s,%d: Q_LOCK()\n", __FILE__, __LINE__); \
			 })
#define	CRYPTO_Q_UNLOCK() \
			({ \
			 	dprintk("%s,%d: Q_UNLOCK()\n", __FILE__, __LINE__); \
				spin_unlock_irqrestore(&crypto_q_lock, q_flags); \
			 })

/*
 * There are two queues for processing completed crypto requests; one
 * for the symmetric and one for the asymmetric ops.  We only need one
 * but have two to avoid type futzing (cryptop vs. cryptkop).  A single
 * mutex is used to lock access to both queues.  Note that this lock
 * must be separate from the lock on request queues to insure driver
 * callbacks don't generate lock order reversals.
 */
static LIST_HEAD(crp_ret_q);		/* callback queues */
static LIST_HEAD(crp_ret_kq);

static spinlock_t crypto_ret_q_lock;
#define	CRYPTO_RETQ_LOCK() \
			({ \
				spin_lock_irqsave(&crypto_ret_q_lock, r_flags); \
				dprintk("%s,%d: RETQ_LOCK\n", __FILE__, __LINE__); \
			 })
#define	CRYPTO_RETQ_UNLOCK() \
			({ \
			 	dprintk("%s,%d: RETQ_UNLOCK\n", __FILE__, __LINE__); \
				spin_unlock_irqrestore(&crypto_ret_q_lock, r_flags); \
			 })
#define	CRYPTO_RETQ_EMPTY()	(list_empty(&crp_ret_q) && list_empty(&crp_ret_kq))

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
static kmem_cache_t *cryptop_zone;
static kmem_cache_t *cryptodesc_zone;
#else
static struct kmem_cache *cryptop_zone;
static struct kmem_cache *cryptodesc_zone;
#endif

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
#include <linux/sched.h>
#define	kill_proc(p,s,v)	send_sig(s,find_task_by_vpid(p),0)
#endif

#define debug crypto_debug
int crypto_debug = 0;
module_param(crypto_debug, int, 0644);
MODULE_PARM_DESC(crypto_debug, "Enable debug");
EXPORT_SYMBOL(crypto_debug);

/*
 * Maximum number of outstanding crypto requests before we start
 * failing requests.  We need this to prevent DOS when too many
 * requests are arriving for us to keep up.  Otherwise we will
 * run the system out of memory.  Since crypto is slow,  we are
 * usually the bottleneck that needs to say, enough is enough.
 *
 * We cannot print errors when this condition occurs,  we are already too
 * slow,  printing anything will just kill us
 */

static int crypto_q_cnt = 0;
module_param(crypto_q_cnt, int, 0444);
MODULE_PARM_DESC(crypto_q_cnt,
		"Current number of outstanding crypto requests");

static int crypto_q_max = 1000;
module_param(crypto_q_max, int, 0644);
MODULE_PARM_DESC(crypto_q_max,
		"Maximum number of outstanding crypto requests");

#define bootverbose crypto_verbose
static int crypto_verbose = 0;
module_param(crypto_verbose, int, 0644);
MODULE_PARM_DESC(crypto_verbose,
		"Enable verbose crypto startup");

int	crypto_usercrypto = 1;	/* userland may do crypto reqs */
module_param(crypto_usercrypto, int, 0644);
MODULE_PARM_DESC(crypto_usercrypto,
	   "Enable/disable user-mode access to crypto support");

int	crypto_userasymcrypto = 1;	/* userland may do asym crypto reqs */
module_param(crypto_userasymcrypto, int, 0644);
MODULE_PARM_DESC(crypto_userasymcrypto,
	   "Enable/disable user-mode access to asymmetric crypto support");

int	crypto_devallowsoft = 0;	/* only use hardware crypto */
module_param(crypto_devallowsoft, int, 0644);
MODULE_PARM_DESC(crypto_devallowsoft,
	   "Enable/disable use of software crypto support");

/*
 * This parameter controls the maximum number of crypto operations to 
 * do consecutively in the crypto kernel thread before scheduling to allow 
 * other processes to run. Without it, it is possible to get into a 
 * situation where the crypto thread never allows any other processes to run.
 * Default to 1000 which should be less than one second.
 */
static int crypto_max_loopcount = 1000;
module_param(crypto_max_loopcount, int, 0644);
MODULE_PARM_DESC(crypto_max_loopcount,
	   "Maximum number of crypto ops to do before yielding to other processes");

static pid_t	cryptoproc = (pid_t) -1;
static struct	completion cryptoproc_exited;
static DECLARE_WAIT_QUEUE_HEAD(cryptoproc_wait);
static pid_t	cryptoretproc = (pid_t) -1;
static struct	completion cryptoretproc_exited;
static DECLARE_WAIT_QUEUE_HEAD(cryptoretproc_wait);

static	int crypto_proc(void *arg);
static	int crypto_ret_proc(void *arg);
static	int crypto_invoke(struct cryptocap *cap, struct cryptop *crp, int hint);
static	int crypto_kinvoke(struct cryptkop *krp, int flags);
static	void crypto_exit(void);
static  int crypto_init(void);

static	struct cryptostats cryptostats;

static struct cryptocap *
crypto_checkdriver(u_int32_t hid)
{
	if (crypto_drivers == NULL)
		return NULL;
	return (hid >= crypto_drivers_num ? NULL : &crypto_drivers[hid]);
}

/*
 * Compare a driver's list of supported algorithms against another
 * list; return non-zero if all algorithms are supported.
 */
static int
driver_suitable(const struct cryptocap *cap, const struct cryptoini *cri)
{
	const struct cryptoini *cr;

	/* See if all the algorithms are supported. */
	for (cr = cri; cr; cr = cr->cri_next)
		if (cap->cc_alg[cr->cri_alg] == 0)
			return 0;
	return 1;
}

/*
 * Select a driver for a new session that supports the specified
 * algorithms and, optionally, is constrained according to the flags.
 * The algorithm we use here is pretty stupid; just use the
 * first driver that supports all the algorithms we need. If there
 * are multiple drivers we choose the driver with the fewest active
 * sessions.  We prefer hardware-backed drivers to software ones.
 *
 * XXX We need more smarts here (in real life too, but that's
 * XXX another story altogether).
 */
static struct cryptocap *
crypto_select_driver(const struct cryptoini *cri, int flags)
{
	struct cryptocap *cap, *best;
	int match, hid;

	CRYPTO_DRIVER_ASSERT();

	/*
	 * Look first for hardware crypto devices if permitted.
	 */
	if (flags & CRYPTOCAP_F_HARDWARE)
		match = CRYPTOCAP_F_HARDWARE;
	else
		match = CRYPTOCAP_F_SOFTWARE;
	best = NULL;
again:
	for (hid = 0; hid < crypto_drivers_num; hid++) {
		cap = &crypto_drivers[hid];
		/*
		 * If it's not initialized, is in the process of
		 * going away, or is not appropriate (hardware
		 * or software based on match), then skip.
		 */
		if (cap->cc_dev == NULL ||
		    (cap->cc_flags & CRYPTOCAP_F_CLEANUP) ||
		    (cap->cc_flags & match) == 0)
			continue;

		/* verify all the algorithms are supported. */
		if (driver_suitable(cap, cri)) {
			if (best == NULL ||
			    cap->cc_sessions < best->cc_sessions)
				best = cap;
		}
	}
	if (best != NULL)
		return best;
	if (match == CRYPTOCAP_F_HARDWARE && (flags & CRYPTOCAP_F_SOFTWARE)) {
		/* sort of an Algol 68-style for loop */
		match = CRYPTOCAP_F_SOFTWARE;
		goto again;
	}
	return best;
}

/*
 * Create a new session.  The crid argument specifies a crypto
 * driver to use or constraints on a driver to select (hardware
 * only, software only, either).  Whatever driver is selected
 * must be capable of the requested crypto algorithms.
 */
int
crypto_newsession(u_int64_t *sid, struct cryptoini *cri, int crid)
{
	struct cryptocap *cap;
	u_int32_t hid, lid;
	int err;
	unsigned long d_flags;

	CRYPTO_DRIVER_LOCK();
	if ((crid & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
		/*
		 * Use specified driver; verify it is capable.
		 */
		cap = crypto_checkdriver(crid);
		if (cap != NULL && !driver_suitable(cap, cri))
			cap = NULL;
	} else {
		/*
		 * No requested driver; select based on crid flags.
		 */
		cap = crypto_select_driver(cri, crid);
		/*
		 * if NULL then can't do everything in one session.
		 * XXX Fix this. We need to inject a "virtual" session
		 * XXX layer right about here.
		 */
	}
	if (cap != NULL) {
		/* Call the driver initialization routine. */
		hid = cap - crypto_drivers;
		lid = hid;		/* Pass the driver ID. */
		cap->cc_sessions++;
		CRYPTO_DRIVER_UNLOCK();
		err = CRYPTODEV_NEWSESSION(cap->cc_dev, &lid, cri);
		CRYPTO_DRIVER_LOCK();
		if (err == 0) {
			(*sid) = (cap->cc_flags & 0xff000000)
			       | (hid & 0x00ffffff);
			(*sid) <<= 32;
			(*sid) |= (lid & 0xffffffff);
		} else
			cap->cc_sessions--;
	} else
		err = EINVAL;
	CRYPTO_DRIVER_UNLOCK();
	return err;
}

static void
crypto_remove(struct cryptocap *cap)
{
	CRYPTO_DRIVER_ASSERT();
	if (cap->cc_sessions == 0 && cap->cc_koperations == 0)
		bzero(cap, sizeof(*cap));
}

/*
 * Delete an existing session (or a reserved session on an unregistered
 * driver).
 */
int
crypto_freesession(u_int64_t sid)
{
	struct cryptocap *cap;
	u_int32_t hid;
	int err = 0;
	unsigned long d_flags;

	dprintk("%s()\n", __FUNCTION__);
	CRYPTO_DRIVER_LOCK();

	if (crypto_drivers == NULL) {
		err = EINVAL;
		goto done;
	}

	/* Determine two IDs. */
	hid = CRYPTO_SESID2HID(sid);

	if (hid >= crypto_drivers_num) {
		dprintk("%s - INVALID DRIVER NUM %d\n", __FUNCTION__, hid);
		err = ENOENT;
		goto done;
	}
	cap = &crypto_drivers[hid];

	if (cap->cc_dev) {
		CRYPTO_DRIVER_UNLOCK();
		/* Call the driver cleanup routine, if available, unlocked. */
		err = CRYPTODEV_FREESESSION(cap->cc_dev, sid);
		CRYPTO_DRIVER_LOCK();
	}

	if (cap->cc_sessions)
		cap->cc_sessions--;

	if (cap->cc_flags & CRYPTOCAP_F_CLEANUP)
		crypto_remove(cap);

done:
	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Return an unused driver id.  Used by drivers prior to registering
 * support for the algorithms they handle.
 */
int32_t
crypto_get_driverid(device_t dev, int flags)
{
	struct cryptocap *newdrv;
	int i;
	unsigned long d_flags;

	if ((flags & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
		printf("%s: no flags specified when registering driver\n",
		    device_get_nameunit(dev));
		return -1;
	}

	CRYPTO_DRIVER_LOCK();

	for (i = 0; i < crypto_drivers_num; i++) {
		if (crypto_drivers[i].cc_dev == NULL &&
		    (crypto_drivers[i].cc_flags & CRYPTOCAP_F_CLEANUP) == 0) {
			break;
		}
	}

	/* Out of entries, allocate some more. */
	if (i == crypto_drivers_num) {
		/* Be careful about wrap-around. */
		if (2 * crypto_drivers_num <= crypto_drivers_num) {
			CRYPTO_DRIVER_UNLOCK();
			printk("crypto: driver count wraparound!\n");
			return -1;
		}

		newdrv = kmalloc(2 * crypto_drivers_num * sizeof(struct cryptocap),
				GFP_KERNEL);
		if (newdrv == NULL) {
			CRYPTO_DRIVER_UNLOCK();
			printk("crypto: no space to expand driver table!\n");
			return -1;
		}

		memcpy(newdrv, crypto_drivers,
				crypto_drivers_num * sizeof(struct cryptocap));
		memset(&newdrv[crypto_drivers_num], 0,
				crypto_drivers_num * sizeof(struct cryptocap));

		crypto_drivers_num *= 2;

		kfree(crypto_drivers);
		crypto_drivers = newdrv;
	}

	/* NB: state is zero'd on free */
	crypto_drivers[i].cc_sessions = 1;	/* Mark */
	crypto_drivers[i].cc_dev = dev;
	crypto_drivers[i].cc_flags = flags;
	if (bootverbose)
		printf("crypto: assign %s driver id %u, flags %u\n",
		    device_get_nameunit(dev), i, flags);

	CRYPTO_DRIVER_UNLOCK();

	return i;
}

/*
 * Lookup a driver by name.  We match against the full device
 * name and unit, and against just the name.  The latter gives
 * us a simple widlcarding by device name.  On success return the
 * driver/hardware identifier; otherwise return -1.
 */
int
crypto_find_driver(const char *match)
{
	int i, len = strlen(match);
	unsigned long d_flags;

	CRYPTO_DRIVER_LOCK();
	for (i = 0; i < crypto_drivers_num; i++) {
		device_t dev = crypto_drivers[i].cc_dev;
		if (dev == NULL ||
		    (crypto_drivers[i].cc_flags & CRYPTOCAP_F_CLEANUP))
			continue;
		if (strncmp(match, device_get_nameunit(dev), len) == 0 ||
		    strncmp(match, device_get_name(dev), len) == 0)
			break;
	}
	CRYPTO_DRIVER_UNLOCK();
	return i < crypto_drivers_num ? i : -1;
}

/*
 * Return the device_t for the specified driver or NULL
 * if the driver identifier is invalid.
 */
device_t
crypto_find_device_byhid(int hid)
{
	struct cryptocap *cap = crypto_checkdriver(hid);
	return cap != NULL ? cap->cc_dev : NULL;
}

/*
 * Return the device/driver capabilities.
 */
int
crypto_getcaps(int hid)
{
	struct cryptocap *cap = crypto_checkdriver(hid);
	return cap != NULL ? cap->cc_flags : 0;
}

/*
 * Register support for a key-related algorithm.  This routine
 * is called once for each algorithm supported a driver.
 */
int
crypto_kregister(u_int32_t driverid, int kalg, u_int32_t flags)
{
	struct cryptocap *cap;
	int err;
	unsigned long d_flags;

	dprintk("%s()\n", __FUNCTION__);
	CRYPTO_DRIVER_LOCK();

	cap = crypto_checkdriver(driverid);
	if (cap != NULL &&
	    (CRK_ALGORITM_MIN <= kalg && kalg <= CRK_ALGORITHM_MAX)) {
		/*
		 * XXX Do some performance testing to determine placing.
		 * XXX We probably need an auxiliary data structure that
		 * XXX describes relative performances.
		 */

		cap->cc_kalg[kalg] = flags | CRYPTO_ALG_FLAG_SUPPORTED;
		if (bootverbose)
			printf("crypto: %s registers key alg %u flags %u\n"
				, device_get_nameunit(cap->cc_dev)
				, kalg
				, flags
			);
		err = 0;
	} else
		err = EINVAL;

	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Register support for a non-key-related algorithm.  This routine
 * is called once for each such algorithm supported by a driver.
 */
int
crypto_register(u_int32_t driverid, int alg, u_int16_t maxoplen,
    u_int32_t flags)
{
	struct cryptocap *cap;
	int err;
	unsigned long d_flags;

	dprintk("%s(id=0x%x, alg=%d, maxoplen=%d, flags=0x%x)\n", __FUNCTION__,
			driverid, alg, maxoplen, flags);

	CRYPTO_DRIVER_LOCK();

	cap = crypto_checkdriver(driverid);
	/* NB: algorithms are in the range [1..max] */
	if (cap != NULL &&
	    (CRYPTO_ALGORITHM_MIN <= alg && alg <= CRYPTO_ALGORITHM_MAX)) {
		/*
		 * XXX Do some performance testing to determine placing.
		 * XXX We probably need an auxiliary data structure that
		 * XXX describes relative performances.
		 */

		cap->cc_alg[alg] = flags | CRYPTO_ALG_FLAG_SUPPORTED;
		cap->cc_max_op_len[alg] = maxoplen;
		if (bootverbose)
			printf("crypto: %s registers alg %u flags %u maxoplen %u\n"
				, device_get_nameunit(cap->cc_dev)
				, alg
				, flags
				, maxoplen
			);
		cap->cc_sessions = 0;		/* Unmark */
		err = 0;
	} else
		err = EINVAL;

	CRYPTO_DRIVER_UNLOCK();
	return err;
}

static void
driver_finis(struct cryptocap *cap)
{
	u_int32_t ses, kops;

	CRYPTO_DRIVER_ASSERT();

	ses = cap->cc_sessions;
	kops = cap->cc_koperations;
	bzero(cap, sizeof(*cap));
	if (ses != 0 || kops != 0) {
		/*
		 * If there are pending sessions,
		 * just mark as invalid.
		 */
		cap->cc_flags |= CRYPTOCAP_F_CLEANUP;
		cap->cc_sessions = ses;
		cap->cc_koperations = kops;
	}
}

/*
 * Unregister a crypto driver. If there are pending sessions using it,
 * leave enough information around so that subsequent calls using those
 * sessions will correctly detect the driver has been unregistered and
 * reroute requests.
 */
int
crypto_unregister(u_int32_t driverid, int alg)
{
	struct cryptocap *cap;
	int i, err;
	unsigned long d_flags;

	dprintk("%s()\n", __FUNCTION__);
	CRYPTO_DRIVER_LOCK();

	cap = crypto_checkdriver(driverid);
	if (cap != NULL &&
	    (CRYPTO_ALGORITHM_MIN <= alg && alg <= CRYPTO_ALGORITHM_MAX) &&
	    cap->cc_alg[alg] != 0) {
		cap->cc_alg[alg] = 0;
		cap->cc_max_op_len[alg] = 0;

		/* Was this the last algorithm ? */
		for (i = 1; i <= CRYPTO_ALGORITHM_MAX; i++)
			if (cap->cc_alg[i] != 0)
				break;

		if (i == CRYPTO_ALGORITHM_MAX + 1)
			driver_finis(cap);
		err = 0;
	} else
		err = EINVAL;
	CRYPTO_DRIVER_UNLOCK();
	return err;
}

/*
 * Unregister all algorithms associated with a crypto driver.
 * If there are pending sessions using it, leave enough information
 * around so that subsequent calls using those sessions will
 * correctly detect the driver has been unregistered and reroute
 * requests.
 */
int
crypto_unregister_all(u_int32_t driverid)
{
	struct cryptocap *cap;
	int err;
	unsigned long d_flags;

	dprintk("%s()\n", __FUNCTION__);
	CRYPTO_DRIVER_LOCK();
	cap = crypto_checkdriver(driverid);
	if (cap != NULL) {
		driver_finis(cap);
		err = 0;
	} else
		err = EINVAL;
	CRYPTO_DRIVER_UNLOCK();

	return err;
}

/*
 * Clear blockage on a driver.  The what parameter indicates whether
 * the driver is now ready for cryptop's and/or cryptokop's.
 */
int
crypto_unblock(u_int32_t driverid, int what)
{
	struct cryptocap *cap;
	int err;
	unsigned long q_flags;

	CRYPTO_Q_LOCK();
	cap = crypto_checkdriver(driverid);
	if (cap != NULL) {
		if (what & CRYPTO_SYMQ) {
			cap->cc_qblocked = 0;
			cap->cc_unqblocked = 0;
			crypto_all_qblocked = 0;
		}
		if (what & CRYPTO_ASYMQ) {
			cap->cc_kqblocked = 0;
			cap->cc_unkqblocked = 0;
			crypto_all_kqblocked = 0;
		}
		if (crp_sleep)
			wake_up_interruptible(&cryptoproc_wait);
		err = 0;
	} else
		err = EINVAL;
	CRYPTO_Q_UNLOCK(); //DAVIDM should this be a driver lock

	return err;
}

/*
 * Add a crypto request to a queue, to be processed by the kernel thread.
 */
int
crypto_dispatch(struct cryptop *crp)
{
	struct cryptocap *cap;
	int result = -1;
	unsigned long q_flags;

	dprintk("%s()\n", __FUNCTION__);

	cryptostats.cs_ops++;

	CRYPTO_Q_LOCK();
	if (crypto_q_cnt >= crypto_q_max) {
		CRYPTO_Q_UNLOCK();
		cryptostats.cs_drops++;
		return ENOMEM;
	}
	crypto_q_cnt++;

	/* make sure we are starting a fresh run on this crp. */
	crp->crp_flags &= ~CRYPTO_F_DONE;
	crp->crp_etype = 0;

	/*
	 * Caller marked the request to be processed immediately; dispatch
	 * it directly to the driver unless the driver is currently blocked.
	 */
	if ((crp->crp_flags & CRYPTO_F_BATCH) == 0) {
		int hid = CRYPTO_SESID2HID(crp->crp_sid);
		cap = crypto_checkdriver(hid);
		/* Driver cannot disappear when there is an active session. */
		KASSERT(cap != NULL, ("%s: Driver disappeared.", __func__));
		if (!cap->cc_qblocked) {
			crypto_all_qblocked = 0;
			crypto_drivers[hid].cc_unqblocked = 1;
			CRYPTO_Q_UNLOCK();
			result = crypto_invoke(cap, crp, 0);
			CRYPTO_Q_LOCK();
			if (result == ERESTART)
				if (crypto_drivers[hid].cc_unqblocked)
					crypto_drivers[hid].cc_qblocked = 1;
			crypto_drivers[hid].cc_unqblocked = 0;
		}
	}
	if (result == ERESTART) {
		/*
		 * The driver ran out of resources, mark the
		 * driver ``blocked'' for cryptop's and put
		 * the request back in the queue.  It would
		 * best to put the request back where we got
		 * it but that's hard so for now we put it
		 * at the front.  This should be ok; putting
		 * it at the end does not work.
		 */
		list_add(&crp->crp_next, &crp_q);
		cryptostats.cs_blocks++;
		result = 0;
	} else if (result == -1) {
		TAILQ_INSERT_TAIL(&crp_q, crp, crp_next);
		result = 0;
	}
	if (crp_sleep)
		wake_up_interruptible(&cryptoproc_wait);
	CRYPTO_Q_UNLOCK();
	return result;
}

/*
 * Add an asymetric crypto request to a queue,
 * to be processed by the kernel thread.
 */
int
crypto_kdispatch(struct cryptkop *krp)
{
	int error;
	unsigned long q_flags;

	cryptostats.cs_kops++;

	error = crypto_kinvoke(krp, krp->krp_crid);
	if (error == ERESTART) {
		CRYPTO_Q_LOCK();
		TAILQ_INSERT_TAIL(&crp_kq, krp, krp_next);
		if (crp_sleep)
			wake_up_interruptible(&cryptoproc_wait);
		CRYPTO_Q_UNLOCK();
		error = 0;
	}
	return error;
}

/*
 * Verify a driver is suitable for the specified operation.
 */
static __inline int
kdriver_suitable(const struct cryptocap *cap, const struct cryptkop *krp)
{
	return (cap->cc_kalg[krp->krp_op] & CRYPTO_ALG_FLAG_SUPPORTED) != 0;
}

/*
 * Select a driver for an asym operation.  The driver must
 * support the necessary algorithm.  The caller can constrain
 * which device is selected with the flags parameter.  The
 * algorithm we use here is pretty stupid; just use the first
 * driver that supports the algorithms we need. If there are
 * multiple suitable drivers we choose the driver with the
 * fewest active operations.  We prefer hardware-backed
 * drivers to software ones when either may be used.
 */
static struct cryptocap *
crypto_select_kdriver(const struct cryptkop *krp, int flags)
{
	struct cryptocap *cap, *best, *blocked;
	int match, hid;

	CRYPTO_DRIVER_ASSERT();

	/*
	 * Look first for hardware crypto devices if permitted.
	 */
	if (flags & CRYPTOCAP_F_HARDWARE)
		match = CRYPTOCAP_F_HARDWARE;
	else
		match = CRYPTOCAP_F_SOFTWARE;
	best = NULL;
	blocked = NULL;
again:
	for (hid = 0; hid < crypto_drivers_num; hid++) {
		cap = &crypto_drivers[hid];
		/*
		 * If it's not initialized, is in the process of
		 * going away, or is not appropriate (hardware
		 * or software based on match), then skip.
		 */
		if (cap->cc_dev == NULL ||
		    (cap->cc_flags & CRYPTOCAP_F_CLEANUP) ||
		    (cap->cc_flags & match) == 0)
			continue;

		/* verify all the algorithms are supported. */
		if (kdriver_suitable(cap, krp)) {
			if (best == NULL ||
			    cap->cc_koperations < best->cc_koperations)
				best = cap;
		}
	}
	if (best != NULL)
		return best;
	if (match == CRYPTOCAP_F_HARDWARE && (flags & CRYPTOCAP_F_SOFTWARE)) {
		/* sort of an Algol 68-style for loop */
		match = CRYPTOCAP_F_SOFTWARE;
		goto again;
	}
	return best;
}

/*
 * Dispatch an assymetric crypto request.
 */
static int
crypto_kinvoke(struct cryptkop *krp, int crid)
{
	struct cryptocap *cap = NULL;
	int error;
	unsigned long d_flags;

	KASSERT(krp != NULL, ("%s: krp == NULL", __func__));
	KASSERT(krp->krp_callback != NULL,
	    ("%s: krp->crp_callback == NULL", __func__));

	CRYPTO_DRIVER_LOCK();
	if ((crid & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
		cap = crypto_checkdriver(crid);
		if (cap != NULL) {
			/*
			 * Driver present, it must support the necessary
			 * algorithm and, if s/w drivers are excluded,
			 * it must be registered as hardware-backed.
			 */
			if (!kdriver_suitable(cap, krp) ||
			    (!crypto_devallowsoft &&
			     (cap->cc_flags & CRYPTOCAP_F_HARDWARE) == 0))
				cap = NULL;
		}
	} else {
		/*
		 * No requested driver; select based on crid flags.
		 */
		if (!crypto_devallowsoft)	/* NB: disallow s/w drivers */
			crid &= ~CRYPTOCAP_F_SOFTWARE;
		cap = crypto_select_kdriver(krp, crid);
	}
	if (cap != NULL && !cap->cc_kqblocked) {
		krp->krp_hid = cap - crypto_drivers;
		cap->cc_koperations++;
		CRYPTO_DRIVER_UNLOCK();
		error = CRYPTODEV_KPROCESS(cap->cc_dev, krp, 0);
		CRYPTO_DRIVER_LOCK();
		if (error == ERESTART) {
			cap->cc_koperations--;
			CRYPTO_DRIVER_UNLOCK();
			return (error);
		}
		/* return the actual device used */
		krp->krp_crid = krp->krp_hid;
	} else {
		/*
		 * NB: cap is !NULL if device is blocked; in
		 *     that case return ERESTART so the operation
		 *     is resubmitted if possible.
		 */
		error = (cap == NULL) ? ENODEV : ERESTART;
	}
	CRYPTO_DRIVER_UNLOCK();

	if (error) {
		krp->krp_status = error;
		crypto_kdone(krp);
	}
	return 0;
}


/*
 * Dispatch a crypto request to the appropriate crypto devices.
 */
static int
crypto_invoke(struct cryptocap *cap, struct cryptop *crp, int hint)
{
	KASSERT(crp != NULL, ("%s: crp == NULL", __func__));
	KASSERT(crp->crp_callback != NULL,
	    ("%s: crp->crp_callback == NULL", __func__));
	KASSERT(crp->crp_desc != NULL, ("%s: crp->crp_desc == NULL", __func__));

	dprintk("%s()\n", __FUNCTION__);

#ifdef CRYPTO_TIMING
	if (crypto_timing)
		crypto_tstat(&cryptostats.cs_invoke, &crp->crp_tstamp);
#endif
	if (cap->cc_flags & CRYPTOCAP_F_CLEANUP) {
		struct cryptodesc *crd;
		u_int64_t nid;

		/*
		 * Driver has unregistered; migrate the session and return
		 * an error to the caller so they'll resubmit the op.
		 *
		 * XXX: What if there are more already queued requests for this
		 *      session?
		 */
		crypto_freesession(crp->crp_sid);

		for (crd = crp->crp_desc; crd->crd_next; crd = crd->crd_next)
			crd->CRD_INI.cri_next = &(crd->crd_next->CRD_INI);

		/* XXX propagate flags from initial session? */
		if (crypto_newsession(&nid, &(crp->crp_desc->CRD_INI),
		    CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE) == 0)
			crp->crp_sid = nid;

		crp->crp_etype = EAGAIN;
		crypto_done(crp);
		return 0;
	} else {
		/*
		 * Invoke the driver to process the request.
		 */
		return CRYPTODEV_PROCESS(cap->cc_dev, crp, hint);
	}
}

/*
 * Release a set of crypto descriptors.
 */
void
crypto_freereq(struct cryptop *crp)
{
	struct cryptodesc *crd;

	if (crp == NULL)
		return;

#ifdef DIAGNOSTIC
	{
		struct cryptop *crp2;
		unsigned long q_flags;

		CRYPTO_Q_LOCK();
		TAILQ_FOREACH(crp2, &crp_q, crp_next) {
			KASSERT(crp2 != crp,
			    ("Freeing cryptop from the crypto queue (%p).",
			    crp));
		}
		CRYPTO_Q_UNLOCK();
		CRYPTO_RETQ_LOCK();
		TAILQ_FOREACH(crp2, &crp_ret_q, crp_next) {
			KASSERT(crp2 != crp,
			    ("Freeing cryptop from the return queue (%p).",
			    crp));
		}
		CRYPTO_RETQ_UNLOCK();
	}
#endif

	while ((crd = crp->crp_desc) != NULL) {
		crp->crp_desc = crd->crd_next;
		kmem_cache_free(cryptodesc_zone, crd);
	}
	kmem_cache_free(cryptop_zone, crp);
}

/*
 * Acquire a set of crypto descriptors.
 */
struct cryptop *
crypto_getreq(int num)
{
	struct cryptodesc *crd;
	struct cryptop *crp;

	crp = kmem_cache_alloc(cryptop_zone, SLAB_ATOMIC);
	if (crp != NULL) {
		memset(crp, 0, sizeof(*crp));
		INIT_LIST_HEAD(&crp->crp_next);
		init_waitqueue_head(&crp->crp_waitq);
		while (num--) {
			crd = kmem_cache_alloc(cryptodesc_zone, SLAB_ATOMIC);
			if (crd == NULL) {
				crypto_freereq(crp);
				return NULL;
			}
			memset(crd, 0, sizeof(*crd));
			crd->crd_next = crp->crp_desc;
			crp->crp_desc = crd;
		}
	}
	return crp;
}

/*
 * Invoke the callback on behalf of the driver.
 */
void
crypto_done(struct cryptop *crp)
{
	unsigned long q_flags;

	dprintk("%s()\n", __FUNCTION__);
	if ((crp->crp_flags & CRYPTO_F_DONE) == 0) {
		crp->crp_flags |= CRYPTO_F_DONE;
		CRYPTO_Q_LOCK();
		crypto_q_cnt--;
		CRYPTO_Q_UNLOCK();
	} else
		printk("crypto: crypto_done op already done, flags 0x%x",
				crp->crp_flags);
	if (crp->crp_etype != 0)
		cryptostats.cs_errs++;
	/*
	 * CBIMM means unconditionally do the callback immediately;
	 * CBIFSYNC means do the callback immediately only if the
	 * operation was done synchronously.  Both are used to avoid
	 * doing extraneous context switches; the latter is mostly
	 * used with the software crypto driver.
	 */
	if ((crp->crp_flags & CRYPTO_F_CBIMM) ||
	    ((crp->crp_flags & CRYPTO_F_CBIFSYNC) &&
	     (CRYPTO_SESID2CAPS(crp->crp_sid) & CRYPTOCAP_F_SYNC))) {
		/*
		 * Do the callback directly.  This is ok when the
		 * callback routine does very little (e.g. the
		 * /dev/crypto callback method just does a wakeup).
		 */
		crp->crp_callback(crp);
	} else {
		unsigned long r_flags;
		/*
		 * Normal case; queue the callback for the thread.
		 */
		CRYPTO_RETQ_LOCK();
		if (CRYPTO_RETQ_EMPTY())
			wake_up_interruptible(&cryptoretproc_wait);/* shared wait channel */
		TAILQ_INSERT_TAIL(&crp_ret_q, crp, crp_next);
		CRYPTO_RETQ_UNLOCK();
	}
}

/*
 * Invoke the callback on behalf of the driver.
 */
void
crypto_kdone(struct cryptkop *krp)
{
	struct cryptocap *cap;
	unsigned long d_flags;

	if ((krp->krp_flags & CRYPTO_KF_DONE) != 0)
		printk("crypto: crypto_kdone op already done, flags 0x%x",
				krp->krp_flags);
	krp->krp_flags |= CRYPTO_KF_DONE;
	if (krp->krp_status != 0)
		cryptostats.cs_kerrs++;

	CRYPTO_DRIVER_LOCK();
	/* XXX: What if driver is loaded in the meantime? */
	if (krp->krp_hid < crypto_drivers_num) {
		cap = &crypto_drivers[krp->krp_hid];
		cap->cc_koperations--;
		KASSERT(cap->cc_koperations >= 0, ("cc_koperations < 0"));
		if (cap->cc_flags & CRYPTOCAP_F_CLEANUP)
			crypto_remove(cap);
	}
	CRYPTO_DRIVER_UNLOCK();

	/*
	 * CBIMM means unconditionally do the callback immediately;
	 * This is used to avoid doing extraneous context switches
	 */
	if ((krp->krp_flags & CRYPTO_KF_CBIMM)) {
		/*
		 * Do the callback directly.  This is ok when the
		 * callback routine does very little (e.g. the
		 * /dev/crypto callback method just does a wakeup).
		 */
		krp->krp_callback(krp);
	} else {
		unsigned long r_flags;
		/*
		 * Normal case; queue the callback for the thread.
		 */
		CRYPTO_RETQ_LOCK();
		if (CRYPTO_RETQ_EMPTY())
			wake_up_interruptible(&cryptoretproc_wait);/* shared wait channel */
		TAILQ_INSERT_TAIL(&crp_ret_kq, krp, krp_next);
		CRYPTO_RETQ_UNLOCK();
	}
}

int
crypto_getfeat(int *featp)
{
	int hid, kalg, feat = 0;
	unsigned long d_flags;

	CRYPTO_DRIVER_LOCK();
	for (hid = 0; hid < crypto_drivers_num; hid++) {
		const struct cryptocap *cap = &crypto_drivers[hid];

		if ((cap->cc_flags & CRYPTOCAP_F_SOFTWARE) &&
		    !crypto_devallowsoft) {
			continue;
		}
		for (kalg = 0; kalg < CRK_ALGORITHM_MAX; kalg++)
			if (cap->cc_kalg[kalg] & CRYPTO_ALG_FLAG_SUPPORTED)
				feat |=  1 << kalg;
	}
	CRYPTO_DRIVER_UNLOCK();
	*featp = feat;
	return (0);
}

/*
 * Crypto thread, dispatches crypto requests.
 */
static int
crypto_proc(void *arg)
{
	struct cryptop *crp, *submit;
	struct cryptkop *krp, *krpp;
	struct cryptocap *cap;
	u_int32_t hid;
	int result, hint;
	unsigned long q_flags;
	int loopcount = 0;

	ocf_daemonize("crypto");

	CRYPTO_Q_LOCK();
	for (;;) {
		/*
		 * we need to make sure we don't get into a busy loop with nothing
		 * to do,  the two crypto_all_*blocked vars help us find out when
		 * we are all full and can do nothing on any driver or Q.  If so we
		 * wait for an unblock.
		 */
		crypto_all_qblocked  = !list_empty(&crp_q);

		/*
		 * Find the first element in the queue that can be
		 * processed and look-ahead to see if multiple ops
		 * are ready for the same driver.
		 */
		submit = NULL;
		hint = 0;
		list_for_each_entry(crp, &crp_q, crp_next) {
			hid = CRYPTO_SESID2HID(crp->crp_sid);
			cap = crypto_checkdriver(hid);
			/*
			 * Driver cannot disappear when there is an active
			 * session.
			 */
			KASSERT(cap != NULL, ("%s:%u Driver disappeared.",
			    __func__, __LINE__));
			if (cap == NULL || cap->cc_dev == NULL) {
				/* Op needs to be migrated, process it. */
				if (submit == NULL)
					submit = crp;
				break;
			}
			if (!cap->cc_qblocked) {
				if (submit != NULL) {
					/*
					 * We stop on finding another op,
					 * regardless whether its for the same
					 * driver or not.  We could keep
					 * searching the queue but it might be
					 * better to just use a per-driver
					 * queue instead.
					 */
					if (CRYPTO_SESID2HID(submit->crp_sid) == hid)
						hint = CRYPTO_HINT_MORE;
					break;
				} else {
					submit = crp;
					if ((submit->crp_flags & CRYPTO_F_BATCH) == 0)
						break;
					/* keep scanning for more are q'd */
				}
			}
		}
		if (submit != NULL) {
			hid = CRYPTO_SESID2HID(submit->crp_sid);
			crypto_all_qblocked = 0;
			list_del(&submit->crp_next);
			crypto_drivers[hid].cc_unqblocked = 1;
			cap = crypto_checkdriver(hid);
			CRYPTO_Q_UNLOCK();
			KASSERT(cap != NULL, ("%s:%u Driver disappeared.",
			    __func__, __LINE__));
			result = crypto_invoke(cap, submit, hint);
			CRYPTO_Q_LOCK();
			if (result == ERESTART) {
				/*
				 * The driver ran out of resources, mark the
				 * driver ``blocked'' for cryptop's and put
				 * the request back in the queue.  It would
				 * best to put the request back where we got
				 * it but that's hard so for now we put it
				 * at the front.  This should be ok; putting
				 * it at the end does not work.
				 */
				/* XXX validate sid again? */
				list_add(&submit->crp_next, &crp_q);
				cryptostats.cs_blocks++;
				if (crypto_drivers[hid].cc_unqblocked)
					crypto_drivers[hid].cc_qblocked=0;
				crypto_drivers[hid].cc_unqblocked=0;
			}
			crypto_drivers[hid].cc_unqblocked = 0;
		}

		crypto_all_kqblocked = !list_empty(&crp_kq);

		/* As above, but for key ops */
		krp = NULL;
		list_for_each_entry(krpp, &crp_kq, krp_next) {
			cap = crypto_checkdriver(krpp->krp_hid);
			if (cap == NULL || cap->cc_dev == NULL) {
				/*
				 * Operation needs to be migrated, invalidate
				 * the assigned device so it will reselect a
				 * new one below.  Propagate the original
				 * crid selection flags if supplied.
				 */
				krp->krp_hid = krp->krp_crid &
				    (CRYPTOCAP_F_SOFTWARE|CRYPTOCAP_F_HARDWARE);
				if (krp->krp_hid == 0)
					krp->krp_hid =
				    CRYPTOCAP_F_SOFTWARE|CRYPTOCAP_F_HARDWARE;
				break;
			}
			if (!cap->cc_kqblocked) {
				krp = krpp;
				break;
			}
		}
		if (krp != NULL) {
			crypto_all_kqblocked = 0;
			list_del(&krp->krp_next);
			crypto_drivers[krp->krp_hid].cc_kqblocked = 1;
			CRYPTO_Q_UNLOCK();
			result = crypto_kinvoke(krp, krp->krp_hid);
			CRYPTO_Q_LOCK();
			if (result == ERESTART) {
				/*
				 * The driver ran out of resources, mark the
				 * driver ``blocked'' for cryptkop's and put
				 * the request back in the queue.  It would
				 * best to put the request back where we got
				 * it but that's hard so for now we put it
				 * at the front.  This should be ok; putting
				 * it at the end does not work.
				 */
				/* XXX validate sid again? */
				list_add(&krp->krp_next, &crp_kq);
				cryptostats.cs_kblocks++;
			} else
				crypto_drivers[krp->krp_hid].cc_kqblocked = 0;
		}

		if (submit == NULL && krp == NULL) {
			/*
			 * Nothing more to be processed.  Sleep until we're
			 * woken because there are more ops to process.
			 * This happens either by submission or by a driver
			 * becoming unblocked and notifying us through
			 * crypto_unblock.  Note that when we wakeup we
			 * start processing each queue again from the
			 * front. It's not clear that it's important to
			 * preserve this ordering since ops may finish
			 * out of order if dispatched to different devices
			 * and some become blocked while others do not.
			 */
			dprintk("%s - sleeping (qe=%d qb=%d kqe=%d kqb=%d)\n",
					__FUNCTION__,
					list_empty(&crp_q), crypto_all_qblocked,
					list_empty(&crp_kq), crypto_all_kqblocked);
			loopcount = 0;
			CRYPTO_Q_UNLOCK();
			crp_sleep = 1;
			wait_event_interruptible(cryptoproc_wait,
					!(list_empty(&crp_q) || crypto_all_qblocked) ||
					!(list_empty(&crp_kq) || crypto_all_kqblocked) ||
					cryptoproc == (pid_t) -1);
			crp_sleep = 0;
			if (signal_pending (current)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
				spin_lock_irq(&current->sigmask_lock);
#endif
				flush_signals(current);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
				spin_unlock_irq(&current->sigmask_lock);
#endif
			}
			CRYPTO_Q_LOCK();
			dprintk("%s - awake\n", __FUNCTION__);
			if (cryptoproc == (pid_t) -1)
				break;
			cryptostats.cs_intrs++;
		} else if (loopcount > crypto_max_loopcount) {
			/*
			 * Give other processes a chance to run if we've 
			 * been using the CPU exclusively for a while.
			 */
			loopcount = 0;
			schedule();
		}
		loopcount++;
	}
	CRYPTO_Q_UNLOCK();
	complete_and_exit(&cryptoproc_exited, 0);
}

/*
 * Crypto returns thread, does callbacks for processed crypto requests.
 * Callbacks are done here, rather than in the crypto drivers, because
 * callbacks typically are expensive and would slow interrupt handling.
 */
static int
crypto_ret_proc(void *arg)
{
	struct cryptop *crpt;
	struct cryptkop *krpt;
	unsigned long  r_flags;

	ocf_daemonize("crypto_ret");

	CRYPTO_RETQ_LOCK();
	for (;;) {
		/* Harvest return q's for completed ops */
		crpt = NULL;
		if (!list_empty(&crp_ret_q))
			crpt = list_entry(crp_ret_q.next, typeof(*crpt), crp_next);
		if (crpt != NULL)
			list_del(&crpt->crp_next);

		krpt = NULL;
		if (!list_empty(&crp_ret_kq))
			krpt = list_entry(crp_ret_kq.next, typeof(*krpt), krp_next);
		if (krpt != NULL)
			list_del(&krpt->krp_next);

		if (crpt != NULL || krpt != NULL) {
			CRYPTO_RETQ_UNLOCK();
			/*
			 * Run callbacks unlocked.
			 */
			if (crpt != NULL)
				crpt->crp_callback(crpt);
			if (krpt != NULL)
				krpt->krp_callback(krpt);
			CRYPTO_RETQ_LOCK();
		} else {
			/*
			 * Nothing more to be processed.  Sleep until we're
			 * woken because there are more returns to process.
			 */
			dprintk("%s - sleeping\n", __FUNCTION__);
			CRYPTO_RETQ_UNLOCK();
			wait_event_interruptible(cryptoretproc_wait,
					cryptoretproc == (pid_t) -1 ||
					!list_empty(&crp_ret_q) ||
					!list_empty(&crp_ret_kq));
			if (signal_pending (current)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
				spin_lock_irq(&current->sigmask_lock);
#endif
				flush_signals(current);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
				spin_unlock_irq(&current->sigmask_lock);
#endif
			}
			CRYPTO_RETQ_LOCK();
			dprintk("%s - awake\n", __FUNCTION__);
			if (cryptoretproc == (pid_t) -1) {
				dprintk("%s - EXITING!\n", __FUNCTION__);
				break;
			}
			cryptostats.cs_rets++;
		}
	}
	CRYPTO_RETQ_UNLOCK();
	complete_and_exit(&cryptoretproc_exited, 0);
}


#if 0 /* should put this into /proc or something */
static void
db_show_drivers(void)
{
	int hid;

	db_printf("%12s %4s %4s %8s %2s %2s\n"
		, "Device"
		, "Ses"
		, "Kops"
		, "Flags"
		, "QB"
		, "KB"
	);
	for (hid = 0; hid < crypto_drivers_num; hid++) {
		const struct cryptocap *cap = &crypto_drivers[hid];
		if (cap->cc_dev == NULL)
			continue;
		db_printf("%-12s %4u %4u %08x %2u %2u\n"
		    , device_get_nameunit(cap->cc_dev)
		    , cap->cc_sessions
		    , cap->cc_koperations
		    , cap->cc_flags
		    , cap->cc_qblocked
		    , cap->cc_kqblocked
		);
	}
}

DB_SHOW_COMMAND(crypto, db_show_crypto)
{
	struct cryptop *crp;

	db_show_drivers();
	db_printf("\n");

	db_printf("%4s %8s %4s %4s %4s %4s %8s %8s\n",
	    "HID", "Caps", "Ilen", "Olen", "Etype", "Flags",
	    "Desc", "Callback");
	TAILQ_FOREACH(crp, &crp_q, crp_next) {
		db_printf("%4u %08x %4u %4u %4u %04x %8p %8p\n"
		    , (int) CRYPTO_SESID2HID(crp->crp_sid)
		    , (int) CRYPTO_SESID2CAPS(crp->crp_sid)
		    , crp->crp_ilen, crp->crp_olen
		    , crp->crp_etype
		    , crp->crp_flags
		    , crp->crp_desc
		    , crp->crp_callback
		);
	}
	if (!TAILQ_EMPTY(&crp_ret_q)) {
		db_printf("\n%4s %4s %4s %8s\n",
		    "HID", "Etype", "Flags", "Callback");
		TAILQ_FOREACH(crp, &crp_ret_q, crp_next) {
			db_printf("%4u %4u %04x %8p\n"
			    , (int) CRYPTO_SESID2HID(crp->crp_sid)
			    , crp->crp_etype
			    , crp->crp_flags
			    , crp->crp_callback
			);
		}
	}
}

DB_SHOW_COMMAND(kcrypto, db_show_kcrypto)
{
	struct cryptkop *krp;

	db_show_drivers();
	db_printf("\n");

	db_printf("%4s %5s %4s %4s %8s %4s %8s\n",
	    "Op", "Status", "#IP", "#OP", "CRID", "HID", "Callback");
	TAILQ_FOREACH(krp, &crp_kq, krp_next) {
		db_printf("%4u %5u %4u %4u %08x %4u %8p\n"
		    , krp->krp_op
		    , krp->krp_status
		    , krp->krp_iparams, krp->krp_oparams
		    , krp->krp_crid, krp->krp_hid
		    , krp->krp_callback
		);
	}
	if (!TAILQ_EMPTY(&crp_ret_q)) {
		db_printf("%4s %5s %8s %4s %8s\n",
		    "Op", "Status", "CRID", "HID", "Callback");
		TAILQ_FOREACH(krp, &crp_ret_kq, krp_next) {
			db_printf("%4u %5u %08x %4u %8p\n"
			    , krp->krp_op
			    , krp->krp_status
			    , krp->krp_crid, krp->krp_hid
			    , krp->krp_callback
			);
		}
	}
}
#endif


static int
crypto_init(void)
{
	int error;

	dprintk("%s(%p)\n", __FUNCTION__, (void *) crypto_init);

	if (crypto_initted)
		return 0;
	crypto_initted = 1;

	spin_lock_init(&crypto_drivers_lock);
	spin_lock_init(&crypto_q_lock);
	spin_lock_init(&crypto_ret_q_lock);

	cryptop_zone = kmem_cache_create("cryptop", sizeof(struct cryptop),
				       0, SLAB_HWCACHE_ALIGN, NULL
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
				       , NULL
#endif
					);

	cryptodesc_zone = kmem_cache_create("cryptodesc", sizeof(struct cryptodesc),
				       0, SLAB_HWCACHE_ALIGN, NULL
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
				       , NULL
#endif
					);

	if (cryptodesc_zone == NULL || cryptop_zone == NULL) {
		printk("crypto: crypto_init cannot setup crypto zones\n");
		error = ENOMEM;
		goto bad;
	}

	crypto_drivers_num = CRYPTO_DRIVERS_INITIAL;
	crypto_drivers = kmalloc(crypto_drivers_num * sizeof(struct cryptocap),
			GFP_KERNEL);
	if (crypto_drivers == NULL) {
		printk("crypto: crypto_init cannot setup crypto drivers\n");
		error = ENOMEM;
		goto bad;
	}

	memset(crypto_drivers, 0, crypto_drivers_num * sizeof(struct cryptocap));

	init_completion(&cryptoproc_exited);
	init_completion(&cryptoretproc_exited);

	cryptoproc = 0; /* to avoid race condition where proc runs first */
	cryptoproc = kernel_thread(crypto_proc, NULL, CLONE_FS|CLONE_FILES);
	if (cryptoproc < 0) {
		error = cryptoproc;
		printk("crypto: crypto_init cannot start crypto thread; error %d",
			error);
		goto bad;
	}

	cryptoretproc = 0; /* to avoid race condition where proc runs first */
	cryptoretproc = kernel_thread(crypto_ret_proc, NULL, CLONE_FS|CLONE_FILES);
	if (cryptoretproc < 0) {
		error = cryptoretproc;
		printk("crypto: crypto_init cannot start cryptoret thread; error %d",
				error);
		goto bad;
	}

	return 0;
bad:
	crypto_exit();
	return error;
}


static void
crypto_exit(void)
{
	pid_t p;
	unsigned long d_flags;

	dprintk("%s()\n", __FUNCTION__);

	/*
	 * Terminate any crypto threads.
	 */

	CRYPTO_DRIVER_LOCK();
	p = cryptoproc;
	cryptoproc = (pid_t) -1;
	kill_proc(p, SIGTERM, 1);
	wake_up_interruptible(&cryptoproc_wait);
	CRYPTO_DRIVER_UNLOCK();

	wait_for_completion(&cryptoproc_exited);

	CRYPTO_DRIVER_LOCK();
	p = cryptoretproc;
	cryptoretproc = (pid_t) -1;
	kill_proc(p, SIGTERM, 1);
	wake_up_interruptible(&cryptoretproc_wait);
	CRYPTO_DRIVER_UNLOCK();

	wait_for_completion(&cryptoretproc_exited);

	/* XXX flush queues??? */

	/* 
	 * Reclaim dynamically allocated resources.
	 */
	if (crypto_drivers != NULL)
		kfree(crypto_drivers);

	if (cryptodesc_zone != NULL)
		kmem_cache_destroy(cryptodesc_zone);
	if (cryptop_zone != NULL)
		kmem_cache_destroy(cryptop_zone);
}


EXPORT_SYMBOL(crypto_newsession);
EXPORT_SYMBOL(crypto_freesession);
EXPORT_SYMBOL(crypto_get_driverid);
EXPORT_SYMBOL(crypto_kregister);
EXPORT_SYMBOL(crypto_register);
EXPORT_SYMBOL(crypto_unregister);
EXPORT_SYMBOL(crypto_unregister_all);
EXPORT_SYMBOL(crypto_unblock);
EXPORT_SYMBOL(crypto_dispatch);
EXPORT_SYMBOL(crypto_kdispatch);
EXPORT_SYMBOL(crypto_freereq);
EXPORT_SYMBOL(crypto_getreq);
EXPORT_SYMBOL(crypto_done);
EXPORT_SYMBOL(crypto_kdone);
EXPORT_SYMBOL(crypto_getfeat);
EXPORT_SYMBOL(crypto_userasymcrypto);
EXPORT_SYMBOL(crypto_getcaps);
EXPORT_SYMBOL(crypto_find_driver);
EXPORT_SYMBOL(crypto_find_device_byhid);

module_init(crypto_init);
module_exit(crypto_exit);

MODULE_LICENSE("BSD");
MODULE_AUTHOR("David McCullough <david_mccullough@mcafee.com>");
MODULE_DESCRIPTION("OCF (OpenBSD Cryptographic Framework)");