aboutsummaryrefslogtreecommitdiff
path: root/drivers/s390/crypto/ap_bus.c
blob: 90bd22014513e7c56d05b7dd7eefe586c982761a (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
/*
 * linux/drivers/s390/crypto/ap_bus.c
 *
 * Copyright (C) 2006 IBM Corporation
 * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
 *	      Martin Schwidefsky <schwidefsky@de.ibm.com>
 *	      Ralph Wuerthner <rwuerthn@de.ibm.com>
 *
 * Adjunct processor bus.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/notifier.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <asm/s390_rdev.h>
#include <asm/reset.h>

#include "ap_bus.h"

/* Some prototypes. */
static void ap_scan_bus(struct work_struct *);
static void ap_poll_all(unsigned long);
static void ap_poll_timeout(unsigned long);
static int ap_poll_thread_start(void);
static void ap_poll_thread_stop(void);
static void ap_request_timeout(unsigned long);

/**
 * Module description.
 */
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("Adjunct Processor Bus driver, "
		   "Copyright 2006 IBM Corporation");
MODULE_LICENSE("GPL");

/**
 * Module parameter
 */
int ap_domain_index = -1;	/* Adjunct Processor Domain Index */
module_param_named(domain, ap_domain_index, int, 0000);
MODULE_PARM_DESC(domain, "domain index for ap devices");
EXPORT_SYMBOL(ap_domain_index);

static int ap_thread_flag = 1;
module_param_named(poll_thread, ap_thread_flag, int, 0000);
MODULE_PARM_DESC(poll_thread, "Turn on/off poll thread, default is 1 (on).");

static struct device *ap_root_device = NULL;
static DEFINE_SPINLOCK(ap_device_lock);
static LIST_HEAD(ap_device_list);

/**
 * Workqueue & timer for bus rescan.
 */
static struct workqueue_struct *ap_work_queue;
static struct timer_list ap_config_timer;
static int ap_config_time = AP_CONFIG_TIME;
static DECLARE_WORK(ap_config_work, ap_scan_bus);

/**
 * Tasklet & timer for AP request polling.
 */
static struct timer_list ap_poll_timer = TIMER_INITIALIZER(ap_poll_timeout,0,0);
static DECLARE_TASKLET(ap_tasklet, ap_poll_all, 0);
static atomic_t ap_poll_requests = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(ap_poll_wait);
static struct task_struct *ap_poll_kthread = NULL;
static DEFINE_MUTEX(ap_poll_thread_mutex);

/**
 * Test if ap instructions are available.
 *
 * Returns 0 if the ap instructions are installed.
 */
static inline int ap_instructions_available(void)
{
	register unsigned long reg0 asm ("0") = AP_MKQID(0,0);
	register unsigned long reg1 asm ("1") = -ENODEV;
	register unsigned long reg2 asm ("2") = 0UL;

	asm volatile(
		"   .long 0xb2af0000\n"		/* PQAP(TAPQ) */
		"0: la    %1,0\n"
		"1:\n"
		EX_TABLE(0b, 1b)
		: "+d" (reg0), "+d" (reg1), "+d" (reg2) : : "cc" );
	return reg1;
}

/**
 * Test adjunct processor queue.
 * @qid: the ap queue number
 * @queue_depth: pointer to queue depth value
 * @device_type: pointer to device type value
 *
 * Returns ap queue status structure.
 */
static inline struct ap_queue_status
ap_test_queue(ap_qid_t qid, int *queue_depth, int *device_type)
{
	register unsigned long reg0 asm ("0") = qid;
	register struct ap_queue_status reg1 asm ("1");
	register unsigned long reg2 asm ("2") = 0UL;

	asm volatile(".long 0xb2af0000"		/* PQAP(TAPQ) */
		     : "+d" (reg0), "=d" (reg1), "+d" (reg2) : : "cc");
	*device_type = (int) (reg2 >> 24);
	*queue_depth = (int) (reg2 & 0xff);
	return reg1;
}

/**
 * Reset adjunct processor queue.
 * @qid: the ap queue number
 *
 * Returns ap queue status structure.
 */
static inline struct ap_queue_status ap_reset_queue(ap_qid_t qid)
{
	register unsigned long reg0 asm ("0") = qid | 0x01000000UL;
	register struct ap_queue_status reg1 asm ("1");
	register unsigned long reg2 asm ("2") = 0UL;

	asm volatile(
		".long 0xb2af0000"		/* PQAP(RAPQ) */
		: "+d" (reg0), "=d" (reg1), "+d" (reg2) : : "cc");
	return reg1;
}

/**
 * Send message to adjunct processor queue.
 * @qid: the ap queue number
 * @psmid: the program supplied message identifier
 * @msg: the message text
 * @length: the message length
 *
 * Returns ap queue status structure.
 *
 * Condition code 1 on NQAP can't happen because the L bit is 1.
 *
 * Condition code 2 on NQAP also means the send is incomplete,
 * because a segment boundary was reached. The NQAP is repeated.
 */
static inline struct ap_queue_status
__ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length)
{
	typedef struct { char _[length]; } msgblock;
	register unsigned long reg0 asm ("0") = qid | 0x40000000UL;
	register struct ap_queue_status reg1 asm ("1");
	register unsigned long reg2 asm ("2") = (unsigned long) msg;
	register unsigned long reg3 asm ("3") = (unsigned long) length;
	register unsigned long reg4 asm ("4") = (unsigned int) (psmid >> 32);
	register unsigned long reg5 asm ("5") = (unsigned int) psmid;

	asm volatile (
		"0: .long 0xb2ad0042\n"		/* DQAP */
		"   brc   2,0b"
		: "+d" (reg0), "=d" (reg1), "+d" (reg2), "+d" (reg3)
		: "d" (reg4), "d" (reg5), "m" (*(msgblock *) msg)
		: "cc" );
	return reg1;
}

int ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length)
{
	struct ap_queue_status status;

	status = __ap_send(qid, psmid, msg, length);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
		return 0;
	case AP_RESPONSE_Q_FULL:
	case AP_RESPONSE_RESET_IN_PROGRESS:
		return -EBUSY;
	default:	/* Device is gone. */
		return -ENODEV;
	}
}
EXPORT_SYMBOL(ap_send);

/*
 * Receive message from adjunct processor queue.
 * @qid: the ap queue number
 * @psmid: pointer to program supplied message identifier
 * @msg: the message text
 * @length: the message length
 *
 * Returns ap queue status structure.
 *
 * Condition code 1 on DQAP means the receive has taken place
 * but only partially.	The response is incomplete, hence the
 * DQAP is repeated.
 *
 * Condition code 2 on DQAP also means the receive is incomplete,
 * this time because a segment boundary was reached. Again, the
 * DQAP is repeated.
 *
 * Note that gpr2 is used by the DQAP instruction to keep track of
 * any 'residual' length, in case the instruction gets interrupted.
 * Hence it gets zeroed before the instruction.
 */
static inline struct ap_queue_status
__ap_recv(ap_qid_t qid, unsigned long long *psmid, void *msg, size_t length)
{
	typedef struct { char _[length]; } msgblock;
	register unsigned long reg0 asm("0") = qid | 0x80000000UL;
	register struct ap_queue_status reg1 asm ("1");
	register unsigned long reg2 asm("2") = 0UL;
	register unsigned long reg4 asm("4") = (unsigned long) msg;
	register unsigned long reg5 asm("5") = (unsigned long) length;
	register unsigned long reg6 asm("6") = 0UL;
	register unsigned long reg7 asm("7") = 0UL;


	asm volatile(
		"0: .long 0xb2ae0064\n"
		"   brc   6,0b\n"
		: "+d" (reg0), "=d" (reg1), "+d" (reg2),
		"+d" (reg4), "+d" (reg5), "+d" (reg6), "+d" (reg7),
		"=m" (*(msgblock *) msg) : : "cc" );
	*psmid = (((unsigned long long) reg6) << 32) + reg7;
	return reg1;
}

int ap_recv(ap_qid_t qid, unsigned long long *psmid, void *msg, size_t length)
{
	struct ap_queue_status status;

	status = __ap_recv(qid, psmid, msg, length);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
		return 0;
	case AP_RESPONSE_NO_PENDING_REPLY:
		if (status.queue_empty)
			return -ENOENT;
		return -EBUSY;
	case AP_RESPONSE_RESET_IN_PROGRESS:
		return -EBUSY;
	default:
		return -ENODEV;
	}
}
EXPORT_SYMBOL(ap_recv);

/**
 * Check if an AP queue is available. The test is repeated for
 * AP_MAX_RESET times.
 * @qid: the ap queue number
 * @queue_depth: pointer to queue depth value
 * @device_type: pointer to device type value
 */
static int ap_query_queue(ap_qid_t qid, int *queue_depth, int *device_type)
{
	struct ap_queue_status status;
	int t_depth, t_device_type, rc, i;

	rc = -EBUSY;
	for (i = 0; i < AP_MAX_RESET; i++) {
		status = ap_test_queue(qid, &t_depth, &t_device_type);
		switch (status.response_code) {
		case AP_RESPONSE_NORMAL:
			*queue_depth = t_depth + 1;
			*device_type = t_device_type;
			rc = 0;
			break;
		case AP_RESPONSE_Q_NOT_AVAIL:
			rc = -ENODEV;
			break;
		case AP_RESPONSE_RESET_IN_PROGRESS:
			break;
		case AP_RESPONSE_DECONFIGURED:
			rc = -ENODEV;
			break;
		case AP_RESPONSE_CHECKSTOPPED:
			rc = -ENODEV;
			break;
		case AP_RESPONSE_BUSY:
			break;
		default:
			BUG();
		}
		if (rc != -EBUSY)
			break;
		if (i < AP_MAX_RESET - 1)
			udelay(5);
	}
	return rc;
}

/**
 * Reset an AP queue and wait for it to become available again.
 * @qid: the ap queue number
 */
static int ap_init_queue(ap_qid_t qid)
{
	struct ap_queue_status status;
	int rc, dummy, i;

	rc = -ENODEV;
	status = ap_reset_queue(qid);
	for (i = 0; i < AP_MAX_RESET; i++) {
		switch (status.response_code) {
		case AP_RESPONSE_NORMAL:
			if (status.queue_empty)
				rc = 0;
			break;
		case AP_RESPONSE_Q_NOT_AVAIL:
		case AP_RESPONSE_DECONFIGURED:
		case AP_RESPONSE_CHECKSTOPPED:
			i = AP_MAX_RESET;	/* return with -ENODEV */
			break;
		case AP_RESPONSE_RESET_IN_PROGRESS:
			rc = -EBUSY;
		case AP_RESPONSE_BUSY:
		default:
			break;
		}
		if (rc != -ENODEV && rc != -EBUSY)
			break;
		if (i < AP_MAX_RESET - 1) {
			udelay(5);
			status = ap_test_queue(qid, &dummy, &dummy);
		}
	}
	return rc;
}

/**
 * Arm request timeout if a AP device was idle and a new request is submitted.
 */
static void ap_increase_queue_count(struct ap_device *ap_dev)
{
	int timeout = ap_dev->drv->request_timeout;

	ap_dev->queue_count++;
	if (ap_dev->queue_count == 1) {
		mod_timer(&ap_dev->timeout, jiffies + timeout);
		ap_dev->reset = AP_RESET_ARMED;
	}
}

/**
 * AP device is still alive, re-schedule request timeout if there are still
 * pending requests.
 */
static void ap_decrease_queue_count(struct ap_device *ap_dev)
{
	int timeout = ap_dev->drv->request_timeout;

	ap_dev->queue_count--;
	if (ap_dev->queue_count > 0)
		mod_timer(&ap_dev->timeout, jiffies + timeout);
	else
		/**
		 * The timeout timer should to be disabled now - since
		 * del_timer_sync() is very expensive, we just tell via the
		 * reset flag to ignore the pending timeout timer.
		 */
		ap_dev->reset = AP_RESET_IGNORE;
}

/**
 * AP device related attributes.
 */
static ssize_t ap_hwtype_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct ap_device *ap_dev = to_ap_dev(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", ap_dev->device_type);
}
static DEVICE_ATTR(hwtype, 0444, ap_hwtype_show, NULL);

static ssize_t ap_depth_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct ap_device *ap_dev = to_ap_dev(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", ap_dev->queue_depth);
}
static DEVICE_ATTR(depth, 0444, ap_depth_show, NULL);

static ssize_t ap_request_count_show(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct ap_device *ap_dev = to_ap_dev(dev);
	int rc;

	spin_lock_bh(&ap_dev->lock);
	rc = snprintf(buf, PAGE_SIZE, "%d\n", ap_dev->total_request_count);
	spin_unlock_bh(&ap_dev->lock);
	return rc;
}

static DEVICE_ATTR(request_count, 0444, ap_request_count_show, NULL);

static ssize_t ap_modalias_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "ap:t%02X", to_ap_dev(dev)->device_type);
}

static DEVICE_ATTR(modalias, 0444, ap_modalias_show, NULL);

static struct attribute *ap_dev_attrs[] = {
	&dev_attr_hwtype.attr,
	&dev_attr_depth.attr,
	&dev_attr_request_count.attr,
	&dev_attr_modalias.attr,
	NULL
};
static struct attribute_group ap_dev_attr_group = {
	.attrs = ap_dev_attrs
};

/**
 * AP bus driver registration/unregistration.
 */
static int ap_bus_match(struct device *dev, struct device_driver *drv)
{
	struct ap_device *ap_dev = to_ap_dev(dev);
	struct ap_driver *ap_drv = to_ap_drv(drv);
	struct ap_device_id *id;

	/**
	 * Compare device type of the device with the list of
	 * supported types of the device_driver.
	 */
	for (id = ap_drv->ids; id->match_flags; id++) {
		if ((id->match_flags & AP_DEVICE_ID_MATCH_DEVICE_TYPE) &&
		    (id->dev_type != ap_dev->device_type))
			continue;
		return 1;
	}
	return 0;
}

/**
 * uevent function for AP devices. It sets up a single environment
 * variable DEV_TYPE which contains the hardware device type.
 */
static int ap_uevent (struct device *dev, char **envp, int num_envp,
		       char *buffer, int buffer_size)
{
	struct ap_device *ap_dev = to_ap_dev(dev);
	int retval = 0, length = 0, i = 0;

	if (!ap_dev)
		return -ENODEV;

	/* Set up DEV_TYPE environment variable. */
	retval = add_uevent_var(envp, num_envp, &i,
				buffer, buffer_size, &length,
				"DEV_TYPE=%04X", ap_dev->device_type);
	if (retval)
		return retval;

	/* Add MODALIAS= */
	retval = add_uevent_var(envp, num_envp, &i,
				buffer, buffer_size, &length,
				"MODALIAS=ap:t%02X", ap_dev->device_type);

	envp[i] = NULL;
	return retval;
}

static struct bus_type ap_bus_type = {
	.name = "ap",
	.match = &ap_bus_match,
	.uevent = &ap_uevent,
};

static int ap_device_probe(struct device *dev)
{
	struct ap_device *ap_dev = to_ap_dev(dev);
	struct ap_driver *ap_drv = to_ap_drv(dev->driver);
	int rc;

	ap_dev->drv = ap_drv;
	spin_lock_bh(&ap_device_lock);
	list_add(&ap_dev->list, &ap_device_list);
	spin_unlock_bh(&ap_device_lock);
	rc = ap_drv->probe ? ap_drv->probe(ap_dev) : -ENODEV;
	return rc;
}

/**
 * Flush all requests from the request/pending queue of an AP device.
 * @ap_dev: pointer to the AP device.
 */
static void __ap_flush_queue(struct ap_device *ap_dev)
{
	struct ap_message *ap_msg, *next;

	list_for_each_entry_safe(ap_msg, next, &ap_dev->pendingq, list) {
		list_del_init(&ap_msg->list);
		ap_dev->pendingq_count--;
		ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
	}
	list_for_each_entry_safe(ap_msg, next, &ap_dev->requestq, list) {
		list_del_init(&ap_msg->list);
		ap_dev->requestq_count--;
		ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
	}
}

void ap_flush_queue(struct ap_device *ap_dev)
{
	spin_lock_bh(&ap_dev->lock);
	__ap_flush_queue(ap_dev);
	spin_unlock_bh(&ap_dev->lock);
}
EXPORT_SYMBOL(ap_flush_queue);

static int ap_device_remove(struct device *dev)
{
	struct ap_device *ap_dev = to_ap_dev(dev);
	struct ap_driver *ap_drv = ap_dev->drv;

	ap_flush_queue(ap_dev);
	del_timer_sync(&ap_dev->timeout);
	if (ap_drv->remove)
		ap_drv->remove(ap_dev);
	spin_lock_bh(&ap_device_lock);
	list_del_init(&ap_dev->list);
	spin_unlock_bh(&ap_device_lock);
	spin_lock_bh(&ap_dev->lock);
	atomic_sub(ap_dev->queue_count, &ap_poll_requests);
	spin_unlock_bh(&ap_dev->lock);
	return 0;
}

int ap_driver_register(struct ap_driver *ap_drv, struct module *owner,
		       char *name)
{
	struct device_driver *drv = &ap_drv->driver;

	drv->bus = &ap_bus_type;
	drv->probe = ap_device_probe;
	drv->remove = ap_device_remove;
	drv->owner = owner;
	drv->name = name;
	return driver_register(drv);
}
EXPORT_SYMBOL(ap_driver_register);

void ap_driver_unregister(struct ap_driver *ap_drv)
{
	driver_unregister(&ap_drv->driver);
}
EXPORT_SYMBOL(ap_driver_unregister);

/**
 * AP bus attributes.
 */
static ssize_t ap_domain_show(struct bus_type *bus, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%d\n", ap_domain_index);
}

static BUS_ATTR(ap_domain, 0444, ap_domain_show, NULL);

static ssize_t ap_config_time_show(struct bus_type *bus, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%d\n", ap_config_time);
}

static ssize_t ap_config_time_store(struct bus_type *bus,
				    const char *buf, size_t count)
{
	int time;

	if (sscanf(buf, "%d\n", &time) != 1 || time < 5 || time > 120)
		return -EINVAL;
	ap_config_time = time;
	if (!timer_pending(&ap_config_timer) ||
	    !mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ)) {
		ap_config_timer.expires = jiffies + ap_config_time * HZ;
		add_timer(&ap_config_timer);
	}
	return count;
}

static BUS_ATTR(config_time, 0644, ap_config_time_show, ap_config_time_store);

static ssize_t ap_poll_thread_show(struct bus_type *bus, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%d\n", ap_poll_kthread ? 1 : 0);
}

static ssize_t ap_poll_thread_store(struct bus_type *bus,
				    const char *buf, size_t count)
{
	int flag, rc;

	if (sscanf(buf, "%d\n", &flag) != 1)
		return -EINVAL;
	if (flag) {
		rc = ap_poll_thread_start();
		if (rc)
			return rc;
	}
	else
		ap_poll_thread_stop();
	return count;
}

static BUS_ATTR(poll_thread, 0644, ap_poll_thread_show, ap_poll_thread_store);

static struct bus_attribute *const ap_bus_attrs[] = {
	&bus_attr_ap_domain,
	&bus_attr_config_time,
	&bus_attr_poll_thread,
	NULL
};

/**
 * Pick one of the 16 ap domains.
 */
static int ap_select_domain(void)
{
	int queue_depth, device_type, count, max_count, best_domain;
	int rc, i, j;

	/**
	 * We want to use a single domain. Either the one specified with
	 * the "domain=" parameter or the domain with the maximum number
	 * of devices.
	 */
	if (ap_domain_index >= 0 && ap_domain_index < AP_DOMAINS)
		/* Domain has already been selected. */
		return 0;
	best_domain = -1;
	max_count = 0;
	for (i = 0; i < AP_DOMAINS; i++) {
		count = 0;
		for (j = 0; j < AP_DEVICES; j++) {
			ap_qid_t qid = AP_MKQID(j, i);
			rc = ap_query_queue(qid, &queue_depth, &device_type);
			if (rc)
				continue;
			count++;
		}
		if (count > max_count) {
			max_count = count;
			best_domain = i;
		}
	}
	if (best_domain >= 0){
		ap_domain_index = best_domain;
		return 0;
	}
	return -ENODEV;
}

/**
 * Find the device type if query queue returned a device type of 0.
 * @ap_dev: pointer to the AP device.
 */
static int ap_probe_device_type(struct ap_device *ap_dev)
{
	static unsigned char msg[] = {
		0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x58,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x01,0x00,0x43,0x43,0x41,0x2d,0x41,0x50,
		0x50,0x4c,0x20,0x20,0x20,0x01,0x01,0x01,
		0x00,0x00,0x00,0x00,0x50,0x4b,0x00,0x00,
		0x00,0x00,0x01,0x1c,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x05,0xb8,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x70,0x00,0x41,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x54,0x32,0x01,0x00,0xa0,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0xb8,0x05,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x0a,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,
		0x49,0x43,0x53,0x46,0x20,0x20,0x20,0x20,
		0x50,0x4b,0x0a,0x00,0x50,0x4b,0x43,0x53,
		0x2d,0x31,0x2e,0x32,0x37,0x00,0x11,0x22,
		0x33,0x44,0x55,0x66,0x77,0x88,0x99,0x00,
		0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88,
		0x99,0x00,0x11,0x22,0x33,0x44,0x55,0x66,
		0x77,0x88,0x99,0x00,0x11,0x22,0x33,0x44,
		0x55,0x66,0x77,0x88,0x99,0x00,0x11,0x22,
		0x33,0x44,0x55,0x66,0x77,0x88,0x99,0x00,
		0x11,0x22,0x33,0x5d,0x00,0x5b,0x00,0x77,
		0x88,0x1e,0x00,0x00,0x57,0x00,0x00,0x00,
		0x00,0x04,0x00,0x00,0x4f,0x00,0x00,0x00,
		0x03,0x02,0x00,0x00,0x40,0x01,0x00,0x01,
		0xce,0x02,0x68,0x2d,0x5f,0xa9,0xde,0x0c,
		0xf6,0xd2,0x7b,0x58,0x4b,0xf9,0x28,0x68,
		0x3d,0xb4,0xf4,0xef,0x78,0xd5,0xbe,0x66,
		0x63,0x42,0xef,0xf8,0xfd,0xa4,0xf8,0xb0,
		0x8e,0x29,0xc2,0xc9,0x2e,0xd8,0x45,0xb8,
		0x53,0x8c,0x6f,0x4e,0x72,0x8f,0x6c,0x04,
		0x9c,0x88,0xfc,0x1e,0xc5,0x83,0x55,0x57,
		0xf7,0xdd,0xfd,0x4f,0x11,0x36,0x95,0x5d,
	};
	struct ap_queue_status status;
	unsigned long long psmid;
	char *reply;
	int rc, i;

	reply = (void *) get_zeroed_page(GFP_KERNEL);
	if (!reply) {
		rc = -ENOMEM;
		goto out;
	}

	status = __ap_send(ap_dev->qid, 0x0102030405060708ULL,
			   msg, sizeof(msg));
	if (status.response_code != AP_RESPONSE_NORMAL) {
		rc = -ENODEV;
		goto out_free;
	}

	/* Wait for the test message to complete. */
	for (i = 0; i < 6; i++) {
		mdelay(300);
		status = __ap_recv(ap_dev->qid, &psmid, reply, 4096);
		if (status.response_code == AP_RESPONSE_NORMAL &&
		    psmid == 0x0102030405060708ULL)
			break;
	}
	if (i < 6) {
		/* Got an answer. */
		if (reply[0] == 0x00 && reply[1] == 0x86)
			ap_dev->device_type = AP_DEVICE_TYPE_PCICC;
		else
			ap_dev->device_type = AP_DEVICE_TYPE_PCICA;
		rc = 0;
	} else
		rc = -ENODEV;

out_free:
	free_page((unsigned long) reply);
out:
	return rc;
}

/**
 * Scan the ap bus for new devices.
 */
static int __ap_scan_bus(struct device *dev, void *data)
{
	return to_ap_dev(dev)->qid == (ap_qid_t)(unsigned long) data;
}

static void ap_device_release(struct device *dev)
{
	struct ap_device *ap_dev = to_ap_dev(dev);

	kfree(ap_dev);
}

static void ap_scan_bus(struct work_struct *unused)
{
	struct ap_device *ap_dev;
	struct device *dev;
	ap_qid_t qid;
	int queue_depth, device_type;
	int rc, i;

	if (ap_select_domain() != 0)
		return;
	for (i = 0; i < AP_DEVICES; i++) {
		qid = AP_MKQID(i, ap_domain_index);
		dev = bus_find_device(&ap_bus_type, NULL,
				      (void *)(unsigned long)qid,
				      __ap_scan_bus);
		rc = ap_query_queue(qid, &queue_depth, &device_type);
		if (dev) {
			if (rc == -EBUSY) {
				set_current_state(TASK_UNINTERRUPTIBLE);
				schedule_timeout(AP_RESET_TIMEOUT);
				rc = ap_query_queue(qid, &queue_depth,
						    &device_type);
			}
			ap_dev = to_ap_dev(dev);
			spin_lock_bh(&ap_dev->lock);
			if (rc || ap_dev->unregistered) {
				spin_unlock_bh(&ap_dev->lock);
				device_unregister(dev);
				put_device(dev);
				continue;
			}
			spin_unlock_bh(&ap_dev->lock);
			put_device(dev);
			continue;
		}
		if (rc)
			continue;
		rc = ap_init_queue(qid);
		if (rc)
			continue;
		ap_dev = kzalloc(sizeof(*ap_dev), GFP_KERNEL);
		if (!ap_dev)
			break;
		ap_dev->qid = qid;
		ap_dev->queue_depth = queue_depth;
		ap_dev->unregistered = 1;
		spin_lock_init(&ap_dev->lock);
		INIT_LIST_HEAD(&ap_dev->pendingq);
		INIT_LIST_HEAD(&ap_dev->requestq);
		INIT_LIST_HEAD(&ap_dev->list);
		setup_timer(&ap_dev->timeout, ap_request_timeout,
			    (unsigned long) ap_dev);
		if (device_type == 0)
			ap_probe_device_type(ap_dev);
		else
			ap_dev->device_type = device_type;

		ap_dev->device.bus = &ap_bus_type;
		ap_dev->device.parent = ap_root_device;
		snprintf(ap_dev->device.bus_id, BUS_ID_SIZE, "card%02x",
			 AP_QID_DEVICE(ap_dev->qid));
		ap_dev->device.release = ap_device_release;
		rc = device_register(&ap_dev->device);
		if (rc) {
			kfree(ap_dev);
			continue;
		}
		/* Add device attributes. */
		rc = sysfs_create_group(&ap_dev->device.kobj,
					&ap_dev_attr_group);
		if (!rc) {
			spin_lock_bh(&ap_dev->lock);
			ap_dev->unregistered = 0;
			spin_unlock_bh(&ap_dev->lock);
		}
		else
			device_unregister(&ap_dev->device);
	}
}

static void
ap_config_timeout(unsigned long ptr)
{
	queue_work(ap_work_queue, &ap_config_work);
	ap_config_timer.expires = jiffies + ap_config_time * HZ;
	add_timer(&ap_config_timer);
}

/**
 * Set up the timer to run the poll tasklet
 */
static inline void ap_schedule_poll_timer(void)
{
	if (timer_pending(&ap_poll_timer))
		return;
	mod_timer(&ap_poll_timer, jiffies + AP_POLL_TIME);
}

/**
 * Receive pending reply messages from an AP device.
 * @ap_dev: pointer to the AP device
 * @flags: pointer to control flags, bit 2^0 is set if another poll is
 *	   required, bit 2^1 is set if the poll timer needs to get armed
 * Returns 0 if the device is still present, -ENODEV if not.
 */
static int ap_poll_read(struct ap_device *ap_dev, unsigned long *flags)
{
	struct ap_queue_status status;
	struct ap_message *ap_msg;

	if (ap_dev->queue_count <= 0)
		return 0;
	status = __ap_recv(ap_dev->qid, &ap_dev->reply->psmid,
			   ap_dev->reply->message, ap_dev->reply->length);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
		atomic_dec(&ap_poll_requests);
		ap_decrease_queue_count(ap_dev);
		list_for_each_entry(ap_msg, &ap_dev->pendingq, list) {
			if (ap_msg->psmid != ap_dev->reply->psmid)
				continue;
			list_del_init(&ap_msg->list);
			ap_dev->pendingq_count--;
			ap_dev->drv->receive(ap_dev, ap_msg, ap_dev->reply);
			break;
		}
		if (ap_dev->queue_count > 0)
			*flags |= 1;
		break;
	case AP_RESPONSE_NO_PENDING_REPLY:
		if (status.queue_empty) {
			/* The card shouldn't forget requests but who knows. */
			atomic_sub(ap_dev->queue_count, &ap_poll_requests);
			ap_dev->queue_count = 0;
			list_splice_init(&ap_dev->pendingq, &ap_dev->requestq);
			ap_dev->requestq_count += ap_dev->pendingq_count;
			ap_dev->pendingq_count = 0;
		} else
			*flags |= 2;
		break;
	default:
		return -ENODEV;
	}
	return 0;
}

/**
 * Send messages from the request queue to an AP device.
 * @ap_dev: pointer to the AP device
 * @flags: pointer to control flags, bit 2^0 is set if another poll is
 *	   required, bit 2^1 is set if the poll timer needs to get armed
 * Returns 0 if the device is still present, -ENODEV if not.
 */
static int ap_poll_write(struct ap_device *ap_dev, unsigned long *flags)
{
	struct ap_queue_status status;
	struct ap_message *ap_msg;

	if (ap_dev->requestq_count <= 0 ||
	    ap_dev->queue_count >= ap_dev->queue_depth)
		return 0;
	/* Start the next request on the queue. */
	ap_msg = list_entry(ap_dev->requestq.next, struct ap_message, list);
	status = __ap_send(ap_dev->qid, ap_msg->psmid,
			   ap_msg->message, ap_msg->length);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
		atomic_inc(&ap_poll_requests);
		ap_increase_queue_count(ap_dev);
		list_move_tail(&ap_msg->list, &ap_dev->pendingq);
		ap_dev->requestq_count--;
		ap_dev->pendingq_count++;
		if (ap_dev->queue_count < ap_dev->queue_depth &&
		    ap_dev->requestq_count > 0)
			*flags |= 1;
		*flags |= 2;
		break;
	case AP_RESPONSE_Q_FULL:
	case AP_RESPONSE_RESET_IN_PROGRESS:
		*flags |= 2;
		break;
	case AP_RESPONSE_MESSAGE_TOO_BIG:
		return -EINVAL;
	default:
		return -ENODEV;
	}
	return 0;
}

/**
 * Poll AP device for pending replies and send new messages. If either
 * ap_poll_read or ap_poll_write returns -ENODEV unregister the device.
 * @ap_dev: pointer to the bus device
 * @flags: pointer to control flags, bit 2^0 is set if another poll is
 *	   required, bit 2^1 is set if the poll timer needs to get armed
 * Returns 0.
 */
static inline int ap_poll_queue(struct ap_device *ap_dev, unsigned long *flags)
{
	int rc;

	rc = ap_poll_read(ap_dev, flags);
	if (rc)
		return rc;
	return ap_poll_write(ap_dev, flags);
}

/**
 * Queue a message to a device.
 * @ap_dev: pointer to the AP device
 * @ap_msg: the message to be queued
 */
static int __ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg)
{
	struct ap_queue_status status;

	if (list_empty(&ap_dev->requestq) &&
	    ap_dev->queue_count < ap_dev->queue_depth) {
		status = __ap_send(ap_dev->qid, ap_msg->psmid,
				   ap_msg->message, ap_msg->length);
		switch (status.response_code) {
		case AP_RESPONSE_NORMAL:
			list_add_tail(&ap_msg->list, &ap_dev->pendingq);
			atomic_inc(&ap_poll_requests);
			ap_dev->pendingq_count++;
			ap_increase_queue_count(ap_dev);
			ap_dev->total_request_count++;
			break;
		case AP_RESPONSE_Q_FULL:
		case AP_RESPONSE_RESET_IN_PROGRESS:
			list_add_tail(&ap_msg->list, &ap_dev->requestq);
			ap_dev->requestq_count++;
			ap_dev->total_request_count++;
			return -EBUSY;
		case AP_RESPONSE_MESSAGE_TOO_BIG:
			ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-EINVAL));
			return -EINVAL;
		default:	/* Device is gone. */
			ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
			return -ENODEV;
		}
	} else {
		list_add_tail(&ap_msg->list, &ap_dev->requestq);
		ap_dev->requestq_count++;
		ap_dev->total_request_count++;
		return -EBUSY;
	}
	ap_schedule_poll_timer();
	return 0;
}

void ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg)
{
	unsigned long flags;
	int rc;

	spin_lock_bh(&ap_dev->lock);
	if (!ap_dev->unregistered) {
		/* Make room on the queue by polling for finished requests. */
		rc = ap_poll_queue(ap_dev, &flags);
		if (!rc)
			rc = __ap_queue_message(ap_dev, ap_msg);
		if (!rc)
			wake_up(&ap_poll_wait);
		if (rc == -ENODEV)
			ap_dev->unregistered = 1;
	} else {
		ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
		rc = -ENODEV;
	}
	spin_unlock_bh(&ap_dev->lock);
	if (rc == -ENODEV)
		device_unregister(&ap_dev->device);
}
EXPORT_SYMBOL(ap_queue_message);

/**
 * Cancel a crypto request. This is done by removing the request
 * from the devive pendingq or requestq queue. Note that the
 * request stays on the AP queue. When it finishes the message
 * reply will be discarded because the psmid can't be found.
 * @ap_dev: AP device that has the message queued
 * @ap_msg: the message that is to be removed
 */
void ap_cancel_message(struct ap_device *ap_dev, struct ap_message *ap_msg)
{
	struct ap_message *tmp;

	spin_lock_bh(&ap_dev->lock);
	if (!list_empty(&ap_msg->list)) {
		list_for_each_entry(tmp, &ap_dev->pendingq, list)
			if (tmp->psmid == ap_msg->psmid) {
				ap_dev->pendingq_count--;
				goto found;
			}
		ap_dev->requestq_count--;
	found:
		list_del_init(&ap_msg->list);
	}
	spin_unlock_bh(&ap_dev->lock);
}
EXPORT_SYMBOL(ap_cancel_message);

/**
 * AP receive polling for finished AP requests
 */
static void ap_poll_timeout(unsigned long unused)
{
	tasklet_schedule(&ap_tasklet);
}

/**
 * Reset a not responding AP device and move all requests from the
 * pending queue to the request queue.
 */
static void ap_reset(struct ap_device *ap_dev)
{
	int rc;

	ap_dev->reset = AP_RESET_IGNORE;
	atomic_sub(ap_dev->queue_count, &ap_poll_requests);
	ap_dev->queue_count = 0;
	list_splice_init(&ap_dev->pendingq, &ap_dev->requestq);
	ap_dev->requestq_count += ap_dev->pendingq_count;
	ap_dev->pendingq_count = 0;
	rc = ap_init_queue(ap_dev->qid);
	if (rc == -ENODEV)
		ap_dev->unregistered = 1;
}

/**
 * Poll all AP devices on the bus in a round robin fashion. Continue
 * polling until bit 2^0 of the control flags is not set. If bit 2^1
 * of the control flags has been set arm the poll timer.
 */
static int __ap_poll_all(struct ap_device *ap_dev, unsigned long *flags)
{
	spin_lock(&ap_dev->lock);
	if (!ap_dev->unregistered) {
		if (ap_poll_queue(ap_dev, flags))
			ap_dev->unregistered = 1;
		if (ap_dev->reset == AP_RESET_DO)
			ap_reset(ap_dev);
	}
	spin_unlock(&ap_dev->lock);
	return 0;
}

static void ap_poll_all(unsigned long dummy)
{
	unsigned long flags;
	struct ap_device *ap_dev;

	do {
		flags = 0;
		spin_lock(&ap_device_lock);
		list_for_each_entry(ap_dev, &ap_device_list, list) {
			__ap_poll_all(ap_dev, &flags);
		}
		spin_unlock(&ap_device_lock);
	} while (flags & 1);
	if (flags & 2)
		ap_schedule_poll_timer();
}

/**
 * AP bus poll thread. The purpose of this thread is to poll for
 * finished requests in a loop if there is a "free" cpu - that is
 * a cpu that doesn't have anything better to do. The polling stops
 * as soon as there is another task or if all messages have been
 * delivered.
 */
static int ap_poll_thread(void *data)
{
	DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
	int requests;
	struct ap_device *ap_dev;

	set_user_nice(current, 19);
	while (1) {
		if (need_resched()) {
			schedule();
			continue;
		}
		add_wait_queue(&ap_poll_wait, &wait);
		set_current_state(TASK_INTERRUPTIBLE);
		if (kthread_should_stop())
			break;
		requests = atomic_read(&ap_poll_requests);
		if (requests <= 0)
			schedule();
		set_current_state(TASK_RUNNING);
		remove_wait_queue(&ap_poll_wait, &wait);

		flags = 0;
		spin_lock_bh(&ap_device_lock);
		list_for_each_entry(ap_dev, &ap_device_list, list) {
			__ap_poll_all(ap_dev, &flags);
		}
		spin_unlock_bh(&ap_device_lock);
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&ap_poll_wait, &wait);
	return 0;
}

static int ap_poll_thread_start(void)
{
	int rc;

	mutex_lock(&ap_poll_thread_mutex);
	if (!ap_poll_kthread) {
		ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
		rc = IS_ERR(ap_poll_kthread) ? PTR_ERR(ap_poll_kthread) : 0;
		if (rc)
			ap_poll_kthread = NULL;
	}
	else
		rc = 0;
	mutex_unlock(&ap_poll_thread_mutex);
	return rc;
}

static void ap_poll_thread_stop(void)
{
	mutex_lock(&ap_poll_thread_mutex);
	if (ap_poll_kthread) {
		kthread_stop(ap_poll_kthread);
		ap_poll_kthread = NULL;
	}
	mutex_unlock(&ap_poll_thread_mutex);
}

/**
 * Handling of request timeouts
 */
static void ap_request_timeout(unsigned long data)
{
	struct ap_device *ap_dev = (struct ap_device *) data;

	if (ap_dev->reset == AP_RESET_ARMED)
		ap_dev->reset = AP_RESET_DO;
}

static void ap_reset_domain(void)
{
	int i;

	for (i = 0; i < AP_DEVICES; i++)
		ap_reset_queue(AP_MKQID(i, ap_domain_index));
}

static void ap_reset_all(void)
{
	int i, j;

	for (i = 0; i < AP_DOMAINS; i++)
		for (j = 0; j < AP_DEVICES; j++)
			ap_reset_queue(AP_MKQID(j, i));
}

static struct reset_call ap_reset_call = {
	.fn = ap_reset_all,
};

/**
 * The module initialization code.
 */
int __init ap_module_init(void)
{
	int rc, i;

	if (ap_domain_index < -1 || ap_domain_index >= AP_DOMAINS) {
		printk(KERN_WARNING "Invalid param: domain = %d. "
		       " Not loading.\n", ap_domain_index);
		return -EINVAL;
	}
	if (ap_instructions_available() != 0) {
		printk(KERN_WARNING "AP instructions not installed.\n");
		return -ENODEV;
	}
	register_reset_call(&ap_reset_call);

	/* Create /sys/bus/ap. */
	rc = bus_register(&ap_bus_type);
	if (rc)
		goto out;
	for (i = 0; ap_bus_attrs[i]; i++) {
		rc = bus_create_file(&ap_bus_type, ap_bus_attrs[i]);
		if (rc)
			goto out_bus;
	}

	/* Create /sys/devices/ap. */
	ap_root_device = s390_root_dev_register("ap");
	rc = IS_ERR(ap_root_device) ? PTR_ERR(ap_root_device) : 0;
	if (rc)
		goto out_bus;

	ap_work_queue = create_singlethread_workqueue("kapwork");
	if (!ap_work_queue) {
		rc = -ENOMEM;
		goto out_root;
	}

	if (ap_select_domain() == 0)
		ap_scan_bus(NULL);

	/* Setup the ap bus rescan timer. */
	init_timer(&ap_config_timer);
	ap_config_timer.function = ap_config_timeout;
	ap_config_timer.data = 0;
	ap_config_timer.expires = jiffies + ap_config_time * HZ;
	add_timer(&ap_config_timer);

	/* Start the low priority AP bus poll thread. */
	if (ap_thread_flag) {
		rc = ap_poll_thread_start();
		if (rc)
			goto out_work;
	}

	return 0;

out_work:
	del_timer_sync(&ap_config_timer);
	del_timer_sync(&ap_poll_timer);
	destroy_workqueue(ap_work_queue);
out_root:
	s390_root_dev_unregister(ap_root_device);
out_bus:
	while (i--)
		bus_remove_file(&ap_bus_type, ap_bus_attrs[i]);
	bus_unregister(&ap_bus_type);
out:
	unregister_reset_call(&ap_reset_call);
	return rc;
}

static int __ap_match_all(struct device *dev, void *data)
{
	return 1;
}

/**
 * The module termination code
 */
void ap_module_exit(void)
{
	int i;
	struct device *dev;

	ap_reset_domain();
	ap_poll_thread_stop();
	del_timer_sync(&ap_config_timer);
	del_timer_sync(&ap_poll_timer);
	destroy_workqueue(ap_work_queue);
	tasklet_kill(&ap_tasklet);
	s390_root_dev_unregister(ap_root_device);
	while ((dev = bus_find_device(&ap_bus_type, NULL, NULL,
		    __ap_match_all)))
	{
		device_unregister(dev);
		put_device(dev);
	}
	for (i = 0; ap_bus_attrs[i]; i++)
		bus_remove_file(&ap_bus_type, ap_bus_attrs[i]);
	bus_unregister(&ap_bus_type);
	unregister_reset_call(&ap_reset_call);
}

#ifndef CONFIG_ZCRYPT_MONOLITHIC
module_init(ap_module_init);
module_exit(ap_module_exit);
#endif