Free Electrons

Embedded Linux Experts

   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
/*
 * finite state machine for device handling
 *
 *    Copyright IBM Corp. 2002, 2008
 *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/string.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/chpid.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "device.h"
#include "chsc.h"
#include "ioasm.h"
#include "chp.h"

static int timeout_log_enabled;

static int __init ccw_timeout_log_setup(char *unused)
{
	timeout_log_enabled = 1;
	return 1;
}

__setup("ccw_timeout_log", ccw_timeout_log_setup);

static void ccw_timeout_log(struct ccw_device *cdev)
{
	struct schib schib;
	struct subchannel *sch;
	struct io_subchannel_private *private;
	union orb *orb;
	int cc;

	sch = to_subchannel(cdev->dev.parent);
	private = to_io_private(sch);
	orb = &private->orb;
	cc = stsch(sch->schid, &schib);

	printk(KERN_WARNING "cio: ccw device timeout occurred at %llx, "
	       "device information:\n", get_tod_clock());
	printk(KERN_WARNING "cio: orb:\n");
	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
		       orb, sizeof(*orb), 0);
	printk(KERN_WARNING "cio: ccw device bus id: %s\n",
	       dev_name(&cdev->dev));
	printk(KERN_WARNING "cio: subchannel bus id: %s\n",
	       dev_name(&sch->dev));
	printk(KERN_WARNING "cio: subchannel lpm: %02x, opm: %02x, "
	       "vpm: %02x\n", sch->lpm, sch->opm, sch->vpm);

	if (orb->tm.b) {
		printk(KERN_WARNING "cio: orb indicates transport mode\n");
		printk(KERN_WARNING "cio: last tcw:\n");
		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
			       (void *)(addr_t)orb->tm.tcw,
			       sizeof(struct tcw), 0);
	} else {
		printk(KERN_WARNING "cio: orb indicates command mode\n");
		if ((void *)(addr_t)orb->cmd.cpa == &private->sense_ccw ||
		    (void *)(addr_t)orb->cmd.cpa == cdev->private->iccws)
			printk(KERN_WARNING "cio: last channel program "
			       "(intern):\n");
		else
			printk(KERN_WARNING "cio: last channel program:\n");

		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
			       (void *)(addr_t)orb->cmd.cpa,
			       sizeof(struct ccw1), 0);
	}
	printk(KERN_WARNING "cio: ccw device state: %d\n",
	       cdev->private->state);
	printk(KERN_WARNING "cio: store subchannel returned: cc=%d\n", cc);
	printk(KERN_WARNING "cio: schib:\n");
	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
		       &schib, sizeof(schib), 0);
	printk(KERN_WARNING "cio: ccw device flags:\n");
	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
		       &cdev->private->flags, sizeof(cdev->private->flags), 0);
}

/*
 * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
 */
static void
ccw_device_timeout(unsigned long data)
{
	struct ccw_device *cdev;

	cdev = (struct ccw_device *) data;
	spin_lock_irq(cdev->ccwlock);
	if (timeout_log_enabled)
		ccw_timeout_log(cdev);
	dev_fsm_event(cdev, DEV_EVENT_TIMEOUT);
	spin_unlock_irq(cdev->ccwlock);
}

/*
 * Set timeout
 */
void
ccw_device_set_timeout(struct ccw_device *cdev, int expires)
{
	if (expires == 0) {
		del_timer(&cdev->private->timer);
		return;
	}
	if (timer_pending(&cdev->private->timer)) {
		if (mod_timer(&cdev->private->timer, jiffies + expires))
			return;
	}
	cdev->private->timer.function = ccw_device_timeout;
	cdev->private->timer.data = (unsigned long) cdev;
	cdev->private->timer.expires = jiffies + expires;
	add_timer(&cdev->private->timer);
}

int
ccw_device_cancel_halt_clear(struct ccw_device *cdev)
{
	struct subchannel *sch;
	int ret;

	sch = to_subchannel(cdev->dev.parent);
	ret = cio_cancel_halt_clear(sch, &cdev->private->iretry);

	if (ret == -EIO)
		CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
			      cdev->private->dev_id.ssid,
			      cdev->private->dev_id.devno);

	return ret;
}

void ccw_device_update_sense_data(struct ccw_device *cdev)
{
	memset(&cdev->id, 0, sizeof(cdev->id));
	cdev->id.cu_type   = cdev->private->senseid.cu_type;
	cdev->id.cu_model  = cdev->private->senseid.cu_model;
	cdev->id.dev_type  = cdev->private->senseid.dev_type;
	cdev->id.dev_model = cdev->private->senseid.dev_model;
}

int ccw_device_test_sense_data(struct ccw_device *cdev)
{
	return cdev->id.cu_type == cdev->private->senseid.cu_type &&
		cdev->id.cu_model == cdev->private->senseid.cu_model &&
		cdev->id.dev_type == cdev->private->senseid.dev_type &&
		cdev->id.dev_model == cdev->private->senseid.dev_model;
}

/*
 * The machine won't give us any notification by machine check if a chpid has
 * been varied online on the SE so we have to find out by magic (i. e. driving
 * the channel subsystem to device selection and updating our path masks).
 */
static void
__recover_lost_chpids(struct subchannel *sch, int old_lpm)
{
	int mask, i;
	struct chp_id chpid;

	chp_id_init(&chpid);
	for (i = 0; i<8; i++) {
		mask = 0x80 >> i;
		if (!(sch->lpm & mask))
			continue;
		if (old_lpm & mask)
			continue;
		chpid.id = sch->schib.pmcw.chpid[i];
		if (!chp_is_registered(chpid))
			css_schedule_eval_all();
	}
}

/*
 * Stop device recognition.
 */
static void
ccw_device_recog_done(struct ccw_device *cdev, int state)
{
	struct subchannel *sch;
	int old_lpm;

	sch = to_subchannel(cdev->dev.parent);

	if (cio_disable_subchannel(sch))
		state = DEV_STATE_NOT_OPER;
	/*
	 * Now that we tried recognition, we have performed device selection
	 * through ssch() and the path information is up to date.
	 */
	old_lpm = sch->lpm;

	/* Check since device may again have become not operational. */
	if (cio_update_schib(sch))
		state = DEV_STATE_NOT_OPER;
	else
		sch->lpm = sch->schib.pmcw.pam & sch->opm;

	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
		/* Force reprobe on all chpids. */
		old_lpm = 0;
	if (sch->lpm != old_lpm)
		__recover_lost_chpids(sch, old_lpm);
	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID &&
	    (state == DEV_STATE_NOT_OPER || state == DEV_STATE_BOXED)) {
		cdev->private->flags.recog_done = 1;
		cdev->private->state = DEV_STATE_DISCONNECTED;
		wake_up(&cdev->private->wait_q);
		return;
	}
	if (cdev->private->flags.resuming) {
		cdev->private->state = state;
		cdev->private->flags.recog_done = 1;
		wake_up(&cdev->private->wait_q);
		return;
	}
	switch (state) {
	case DEV_STATE_NOT_OPER:
		break;
	case DEV_STATE_OFFLINE:
		if (!cdev->online) {
			ccw_device_update_sense_data(cdev);
			break;
		}
		cdev->private->state = DEV_STATE_OFFLINE;
		cdev->private->flags.recog_done = 1;
		if (ccw_device_test_sense_data(cdev)) {
			cdev->private->flags.donotify = 1;
			ccw_device_online(cdev);
			wake_up(&cdev->private->wait_q);
		} else {
			ccw_device_update_sense_data(cdev);
			ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
		}
		return;
	case DEV_STATE_BOXED:
		if (cdev->id.cu_type != 0) { /* device was recognized before */
			cdev->private->flags.recog_done = 1;
			cdev->private->state = DEV_STATE_BOXED;
			wake_up(&cdev->private->wait_q);
			return;
		}
		break;
	}
	cdev->private->state = state;
	io_subchannel_recog_done(cdev);
	wake_up(&cdev->private->wait_q);
}

/*
 * Function called from device_id.c after sense id has completed.
 */
void
ccw_device_sense_id_done(struct ccw_device *cdev, int err)
{
	switch (err) {
	case 0:
		ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
		break;
	case -ETIME:		/* Sense id stopped by timeout. */
		ccw_device_recog_done(cdev, DEV_STATE_BOXED);
		break;
	default:
		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
		break;
	}
}

/**
  * ccw_device_notify() - inform the device's driver about an event
  * @cdev: device for which an event occurred
  * @event: event that occurred
  *
  * Returns:
  *   -%EINVAL if the device is offline or has no driver.
  *   -%EOPNOTSUPP if the device's driver has no notifier registered.
  *   %NOTIFY_OK if the driver wants to keep the device.
  *   %NOTIFY_BAD if the driver doesn't want to keep the device.
  */
int ccw_device_notify(struct ccw_device *cdev, int event)
{
	int ret = -EINVAL;

	if (!cdev->drv)
		goto out;
	if (!cdev->online)
		goto out;
	CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
		      event);
	if (!cdev->drv->notify) {
		ret = -EOPNOTSUPP;
		goto out;
	}
	if (cdev->drv->notify(cdev, event))
		ret = NOTIFY_OK;
	else
		ret = NOTIFY_BAD;
out:
	return ret;
}

static void ccw_device_oper_notify(struct ccw_device *cdev)
{
	struct subchannel *sch = to_subchannel(cdev->dev.parent);

	if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
		/* Reenable channel measurements, if needed. */
		ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
		/* Save indication for new paths. */
		cdev->private->path_new_mask = sch->vpm;
		return;
	}
	/* Driver doesn't want device back. */
	ccw_device_set_notoper(cdev);
	ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
}

/*
 * Finished with online/offline processing.
 */
static void
ccw_device_done(struct ccw_device *cdev, int state)
{
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);

	ccw_device_set_timeout(cdev, 0);

	if (state != DEV_STATE_ONLINE)
		cio_disable_subchannel(sch);

	/* Reset device status. */
	memset(&cdev->private->irb, 0, sizeof(struct irb));

	cdev->private->state = state;

	switch (state) {
	case DEV_STATE_BOXED:
		CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
			      cdev->private->dev_id.devno, sch->schid.sch_no);
		if (cdev->online &&
		    ccw_device_notify(cdev, CIO_BOXED) != NOTIFY_OK)
			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
		cdev->private->flags.donotify = 0;
		break;
	case DEV_STATE_NOT_OPER:
		CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
			      cdev->private->dev_id.devno, sch->schid.sch_no);
		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
		else
			ccw_device_set_disconnected(cdev);
		cdev->private->flags.donotify = 0;
		break;
	case DEV_STATE_DISCONNECTED:
		CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
			      "%04x\n", cdev->private->dev_id.devno,
			      sch->schid.sch_no);
		if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK) {
			cdev->private->state = DEV_STATE_NOT_OPER;
			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
		} else
			ccw_device_set_disconnected(cdev);
		cdev->private->flags.donotify = 0;
		break;
	default:
		break;
	}

	if (cdev->private->flags.donotify) {
		cdev->private->flags.donotify = 0;
		ccw_device_oper_notify(cdev);
	}
	wake_up(&cdev->private->wait_q);
}

/*
 * Start device recognition.
 */
void ccw_device_recognition(struct ccw_device *cdev)
{
	struct subchannel *sch = to_subchannel(cdev->dev.parent);

	/*
	 * We used to start here with a sense pgid to find out whether a device
	 * is locked by someone else. Unfortunately, the sense pgid command
	 * code has other meanings on devices predating the path grouping
	 * algorithm, so we start with sense id and box the device after an
	 * timeout (or if sense pgid during path verification detects the device
	 * is locked, as may happen on newer devices).
	 */
	cdev->private->flags.recog_done = 0;
	cdev->private->state = DEV_STATE_SENSE_ID;
	if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
		return;
	}
	ccw_device_sense_id_start(cdev);
}

/*
 * Handle events for states that use the ccw request infrastructure.
 */
static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
{
	switch (e) {
	case DEV_EVENT_NOTOPER:
		ccw_request_notoper(cdev);
		break;
	case DEV_EVENT_INTERRUPT:
		ccw_request_handler(cdev);
		break;
	case DEV_EVENT_TIMEOUT:
		ccw_request_timeout(cdev);
		break;
	default:
		break;
	}
}

static void ccw_device_report_path_events(struct ccw_device *cdev)
{
	struct subchannel *sch = to_subchannel(cdev->dev.parent);
	int path_event[8];
	int chp, mask;

	for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
		path_event[chp] = PE_NONE;
		if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
			path_event[chp] |= PE_PATH_GONE;
		if (mask & cdev->private->path_new_mask & sch->vpm)
			path_event[chp] |= PE_PATH_AVAILABLE;
		if (mask & cdev->private->pgid_reset_mask & sch->vpm)
			path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
	}
	if (cdev->online && cdev->drv->path_event)
		cdev->drv->path_event(cdev, path_event);
}

static void ccw_device_reset_path_events(struct ccw_device *cdev)
{
	cdev->private->path_gone_mask = 0;
	cdev->private->path_new_mask = 0;
	cdev->private->pgid_reset_mask = 0;
}

static void create_fake_irb(struct irb *irb, int type)
{
	memset(irb, 0, sizeof(*irb));
	if (type == FAKE_CMD_IRB) {
		struct cmd_scsw *scsw = &irb->scsw.cmd;
		scsw->cc = 1;
		scsw->fctl = SCSW_FCTL_START_FUNC;
		scsw->actl = SCSW_ACTL_START_PEND;
		scsw->stctl = SCSW_STCTL_STATUS_PEND;
	} else if (type == FAKE_TM_IRB) {
		struct tm_scsw *scsw = &irb->scsw.tm;
		scsw->x = 1;
		scsw->cc = 1;
		scsw->fctl = SCSW_FCTL_START_FUNC;
		scsw->actl = SCSW_ACTL_START_PEND;
		scsw->stctl = SCSW_STCTL_STATUS_PEND;
	}
}

void ccw_device_verify_done(struct ccw_device *cdev, int err)
{
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);
	/* Update schib - pom may have changed. */
	if (cio_update_schib(sch)) {
		err = -ENODEV;
		goto callback;
	}
	/* Update lpm with verified path mask. */
	sch->lpm = sch->vpm;
	/* Repeat path verification? */
	if (cdev->private->flags.doverify) {
		ccw_device_verify_start(cdev);
		return;
	}
callback:
	switch (err) {
	case 0:
		ccw_device_done(cdev, DEV_STATE_ONLINE);
		/* Deliver fake irb to device driver, if needed. */
		if (cdev->private->flags.fake_irb) {
			create_fake_irb(&cdev->private->irb,
					cdev->private->flags.fake_irb);
			cdev->private->flags.fake_irb = 0;
			if (cdev->handler)
				cdev->handler(cdev, cdev->private->intparm,
					      &cdev->private->irb);
			memset(&cdev->private->irb, 0, sizeof(struct irb));
		}
		ccw_device_report_path_events(cdev);
		break;
	case -ETIME:
	case -EUSERS:
		/* Reset oper notify indication after verify error. */
		cdev->private->flags.donotify = 0;
		ccw_device_done(cdev, DEV_STATE_BOXED);
		break;
	case -EACCES:
		/* Reset oper notify indication after verify error. */
		cdev->private->flags.donotify = 0;
		ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
		break;
	default:
		/* Reset oper notify indication after verify error. */
		cdev->private->flags.donotify = 0;
		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
		break;
	}
	ccw_device_reset_path_events(cdev);
}

/*
 * Get device online.
 */
int
ccw_device_online(struct ccw_device *cdev)
{
	struct subchannel *sch;
	int ret;

	if ((cdev->private->state != DEV_STATE_OFFLINE) &&
	    (cdev->private->state != DEV_STATE_BOXED))
		return -EINVAL;
	sch = to_subchannel(cdev->dev.parent);
	ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
	if (ret != 0) {
		/* Couldn't enable the subchannel for i/o. Sick device. */
		if (ret == -ENODEV)
			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
		return ret;
	}
	/* Start initial path verification. */
	cdev->private->state = DEV_STATE_VERIFY;
	ccw_device_verify_start(cdev);
	return 0;
}

void
ccw_device_disband_done(struct ccw_device *cdev, int err)
{
	switch (err) {
	case 0:
		ccw_device_done(cdev, DEV_STATE_OFFLINE);
		break;
	case -ETIME:
		ccw_device_done(cdev, DEV_STATE_BOXED);
		break;
	default:
		cdev->private->flags.donotify = 0;
		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
		break;
	}
}

/*
 * Shutdown device.
 */
int
ccw_device_offline(struct ccw_device *cdev)
{
	struct subchannel *sch;

	/* Allow ccw_device_offline while disconnected. */
	if (cdev->private->state == DEV_STATE_DISCONNECTED ||
	    cdev->private->state == DEV_STATE_NOT_OPER) {
		cdev->private->flags.donotify = 0;
		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
		return 0;
	}
	if (cdev->private->state == DEV_STATE_BOXED) {
		ccw_device_done(cdev, DEV_STATE_BOXED);
		return 0;
	}
	if (ccw_device_is_orphan(cdev)) {
		ccw_device_done(cdev, DEV_STATE_OFFLINE);
		return 0;
	}
	sch = to_subchannel(cdev->dev.parent);
	if (cio_update_schib(sch))
		return -ENODEV;
	if (scsw_actl(&sch->schib.scsw) != 0)
		return -EBUSY;
	if (cdev->private->state != DEV_STATE_ONLINE)
		return -EINVAL;
	/* Are we doing path grouping? */
	if (!cdev->private->flags.pgroup) {
		/* No, set state offline immediately. */
		ccw_device_done(cdev, DEV_STATE_OFFLINE);
		return 0;
	}
	/* Start Set Path Group commands. */
	cdev->private->state = DEV_STATE_DISBAND_PGID;
	ccw_device_disband_start(cdev);
	return 0;
}

/*
 * Handle not operational event in non-special state.
 */
static void ccw_device_generic_notoper(struct ccw_device *cdev,
				       enum dev_event dev_event)
{
	if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
	else
		ccw_device_set_disconnected(cdev);
}

/*
 * Handle path verification event in offline state.
 */
static void ccw_device_offline_verify(struct ccw_device *cdev,
				      enum dev_event dev_event)
{
	struct subchannel *sch = to_subchannel(cdev->dev.parent);

	css_schedule_eval(sch->schid);
}

/*
 * Handle path verification event.
 */
static void
ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;

	if (cdev->private->state == DEV_STATE_W4SENSE) {
		cdev->private->flags.doverify = 1;
		return;
	}
	sch = to_subchannel(cdev->dev.parent);
	/*
	 * Since we might not just be coming from an interrupt from the
	 * subchannel we have to update the schib.
	 */
	if (cio_update_schib(sch)) {
		ccw_device_verify_done(cdev, -ENODEV);
		return;
	}

	if (scsw_actl(&sch->schib.scsw) != 0 ||
	    (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
	    (scsw_stctl(&cdev->private->irb.scsw) & SCSW_STCTL_STATUS_PEND)) {
		/*
		 * No final status yet or final status not yet delivered
		 * to the device driver. Can't do path verification now,
		 * delay until final status was delivered.
		 */
		cdev->private->flags.doverify = 1;
		return;
	}
	/* Device is idle, we can do the path verification. */
	cdev->private->state = DEV_STATE_VERIFY;
	ccw_device_verify_start(cdev);
}

/*
 * Handle path verification event in boxed state.
 */
static void ccw_device_boxed_verify(struct ccw_device *cdev,
				    enum dev_event dev_event)
{
	struct subchannel *sch = to_subchannel(cdev->dev.parent);

	if (cdev->online) {
		if (cio_enable_subchannel(sch, (u32) (addr_t) sch))
			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
		else
			ccw_device_online_verify(cdev, dev_event);
	} else
		css_schedule_eval(sch->schid);
}

/*
 * Pass interrupt to device driver.
 */
static int ccw_device_call_handler(struct ccw_device *cdev)
{
	unsigned int stctl;
	int ending_status;

	/*
	 * we allow for the device action handler if .
	 *  - we received ending status
	 *  - the action handler requested to see all interrupts
	 *  - we received an intermediate status
	 *  - fast notification was requested (primary status)
	 *  - unsolicited interrupts
	 */
	stctl = scsw_stctl(&cdev->private->irb.scsw);
	ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
		(stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
		(stctl == SCSW_STCTL_STATUS_PEND);
	if (!ending_status &&
	    !cdev->private->options.repall &&
	    !(stctl & SCSW_STCTL_INTER_STATUS) &&
	    !(cdev->private->options.fast &&
	      (stctl & SCSW_STCTL_PRIM_STATUS)))
		return 0;

	if (ending_status)
		ccw_device_set_timeout(cdev, 0);

	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      &cdev->private->irb);

	memset(&cdev->private->irb, 0, sizeof(struct irb));
	return 1;
}

/*
 * Got an interrupt for a normal io (state online).
 */
static void
ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct irb *irb;
	int is_cmd;

	irb = this_cpu_ptr(&cio_irb);
	is_cmd = !scsw_is_tm(&irb->scsw);
	/* Check for unsolicited interrupt. */
	if (!scsw_is_solicited(&irb->scsw)) {
		if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
		    !irb->esw.esw0.erw.cons) {
			/* Unit check but no sense data. Need basic sense. */
			if (ccw_device_do_sense(cdev, irb) != 0)
				goto call_handler_unsol;
			memcpy(&cdev->private->irb, irb, sizeof(struct irb));
			cdev->private->state = DEV_STATE_W4SENSE;
			cdev->private->intparm = 0;
			return;
		}
call_handler_unsol:
		if (cdev->handler)
			cdev->handler (cdev, 0, irb);
		if (cdev->private->flags.doverify)
			ccw_device_online_verify(cdev, 0);
		return;
	}
	/* Accumulate status and find out if a basic sense is needed. */
	ccw_device_accumulate_irb(cdev, irb);
	if (is_cmd && cdev->private->flags.dosense) {
		if (ccw_device_do_sense(cdev, irb) == 0) {
			cdev->private->state = DEV_STATE_W4SENSE;
		}
		return;
	}
	/* Call the handler. */
	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
		/* Start delayed path verification. */
		ccw_device_online_verify(cdev, 0);
}

/*
 * Got an timeout in online state.
 */
static void
ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
{
	int ret;

	ccw_device_set_timeout(cdev, 0);
	cdev->private->iretry = 255;
	ret = ccw_device_cancel_halt_clear(cdev);
	if (ret == -EBUSY) {
		ccw_device_set_timeout(cdev, 3*HZ);
		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
		return;
	}
	if (ret)
		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
	else if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-ETIMEDOUT));
}

/*
 * Got an interrupt for a basic sense.
 */
static void
ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct irb *irb;

	irb = this_cpu_ptr(&cio_irb);
	/* Check for unsolicited interrupt. */
	if (scsw_stctl(&irb->scsw) ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (scsw_cc(&irb->scsw) == 1)
			/* Basic sense hasn't started. Try again. */
			ccw_device_do_sense(cdev, irb);
		else {
			CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
				      "interrupt during w4sense...\n",
				      cdev->private->dev_id.ssid,
				      cdev->private->dev_id.devno);
			if (cdev->handler)
				cdev->handler (cdev, 0, irb);
		}
		return;
	}
	/*
	 * Check if a halt or clear has been issued in the meanwhile. If yes,
	 * only deliver the halt/clear interrupt to the device driver as if it
	 * had killed the original request.
	 */
	if (scsw_fctl(&irb->scsw) &
	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
		cdev->private->flags.dosense = 0;
		memset(&cdev->private->irb, 0, sizeof(struct irb));
		ccw_device_accumulate_irb(cdev, irb);
		goto call_handler;
	}
	/* Add basic sense info to irb. */
	ccw_device_accumulate_basic_sense(cdev, irb);
	if (cdev->private->flags.dosense) {
		/* Another basic sense is needed. */
		ccw_device_do_sense(cdev, irb);
		return;
	}
call_handler:
	cdev->private->state = DEV_STATE_ONLINE;
	/* In case sensing interfered with setting the device online */
	wake_up(&cdev->private->wait_q);
	/* Call the handler. */
	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
		/* Start delayed path verification. */
		ccw_device_online_verify(cdev, 0);
}

static void
ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	ccw_device_set_timeout(cdev, 0);
	/* Start delayed path verification. */
	ccw_device_online_verify(cdev, 0);
	/* OK, i/o is dead now. Call interrupt handler. */
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-EIO));
}

static void
ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
{
	int ret;

	ret = ccw_device_cancel_halt_clear(cdev);
	if (ret == -EBUSY) {
		ccw_device_set_timeout(cdev, 3*HZ);
		return;
	}
	/* Start delayed path verification. */
	ccw_device_online_verify(cdev, 0);
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-EIO));
}

void ccw_device_kill_io(struct ccw_device *cdev)
{
	int ret;

	cdev->private->iretry = 255;
	ret = ccw_device_cancel_halt_clear(cdev);
	if (ret == -EBUSY) {
		ccw_device_set_timeout(cdev, 3*HZ);
		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
		return;
	}
	/* Start delayed path verification. */
	ccw_device_online_verify(cdev, 0);
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-EIO));
}

static void
ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
{
	/* Start verification after current task finished. */
	cdev->private->flags.doverify = 1;
}

static void
ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);
	if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
		/* Couldn't enable the subchannel for i/o. Sick device. */
		return;
	cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
	ccw_device_sense_id_start(cdev);
}

void ccw_device_trigger_reprobe(struct ccw_device *cdev)
{
	struct subchannel *sch;

	if (cdev->private->state != DEV_STATE_DISCONNECTED)
		return;

	sch = to_subchannel(cdev->dev.parent);
	/* Update some values. */
	if (cio_update_schib(sch))
		return;
	/*
	 * The pim, pam, pom values may not be accurate, but they are the best
	 * we have before performing device selection :/
	 */
	sch->lpm = sch->schib.pmcw.pam & sch->opm;
	/*
	 * Use the initial configuration since we can't be shure that the old
	 * paths are valid.
	 */
	io_subchannel_init_config(sch);
	if (cio_commit_config(sch))
		return;

	/* We should also udate ssd info, but this has to wait. */
	/* Check if this is another device which appeared on the same sch. */
	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
		css_schedule_eval(sch->schid);
	else
		ccw_device_start_id(cdev, 0);
}

static void ccw_device_disabled_irq(struct ccw_device *cdev,
				    enum dev_event dev_event)
{
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);
	/*
	 * An interrupt in a disabled state means a previous disable was not
	 * successful - should not happen, but we try to disable again.
	 */
	cio_disable_subchannel(sch);
}

static void
ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
{
	retry_set_schib(cdev);
	cdev->private->state = DEV_STATE_ONLINE;
	dev_fsm_event(cdev, dev_event);
}

static void ccw_device_update_cmfblock(struct ccw_device *cdev,
				       enum dev_event dev_event)
{
	cmf_retry_copy_block(cdev);
	cdev->private->state = DEV_STATE_ONLINE;
	dev_fsm_event(cdev, dev_event);
}

static void
ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
{
	ccw_device_set_timeout(cdev, 0);
	cdev->private->state = DEV_STATE_NOT_OPER;
	wake_up(&cdev->private->wait_q);
}

static void
ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
{
	int ret;

	ret = ccw_device_cancel_halt_clear(cdev);
	if (ret == -EBUSY) {
		ccw_device_set_timeout(cdev, HZ/10);
	} else {
		cdev->private->state = DEV_STATE_NOT_OPER;
		wake_up(&cdev->private->wait_q);
	}
}

/*
 * No operation action. This is used e.g. to ignore a timeout event in
 * state offline.
 */
static void
ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
{
}

/*
 * device statemachine
 */
fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
	[DEV_STATE_NOT_OPER] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_SENSE_ID] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_OFFLINE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_offline_verify,
	},
	[DEV_STATE_VERIFY] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
		[DEV_EVENT_VERIFY]	= ccw_device_delay_verify,
	},
	[DEV_STATE_ONLINE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_online_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
	},
	[DEV_STATE_W4SENSE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_w4sense,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
	},
	[DEV_STATE_DISBAND_PGID] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_BOXED] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_nop,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_boxed_verify,
	},
	/* states to wait for i/o completion before doing something */
	[DEV_STATE_TIMEOUT_KILL] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_killing_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_nop, //FIXME
	},
	[DEV_STATE_QUIESCE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_quiesce_done,
		[DEV_EVENT_INTERRUPT]	= ccw_device_quiesce_done,
		[DEV_EVENT_TIMEOUT]	= ccw_device_quiesce_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	/* special states for devices gone not operational */
	[DEV_STATE_DISCONNECTED] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
		[DEV_EVENT_INTERRUPT]	= ccw_device_start_id,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_start_id,
	},
	[DEV_STATE_DISCONNECTED_SENSE_ID] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_CMFCHANGE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_change_cmfstate,
		[DEV_EVENT_INTERRUPT]	= ccw_device_change_cmfstate,
		[DEV_EVENT_TIMEOUT]	= ccw_device_change_cmfstate,
		[DEV_EVENT_VERIFY]	= ccw_device_change_cmfstate,
	},
	[DEV_STATE_CMFUPDATE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_update_cmfblock,
		[DEV_EVENT_INTERRUPT]	= ccw_device_update_cmfblock,
		[DEV_EVENT_TIMEOUT]	= ccw_device_update_cmfblock,
		[DEV_EVENT_VERIFY]	= ccw_device_update_cmfblock,
	},
	[DEV_STATE_STEAL_LOCK] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
};

EXPORT_SYMBOL_GPL(ccw_device_set_timeout);