aboutsummaryrefslogtreecommitdiff
path: root/drivers/s390/scsi/zfcp_aux.c
blob: 2bd80fdcceffd932e6c71514abf7d2aff7adbb4b (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
/*
 * zfcp device driver
 *
 * Module interface and handling of zfcp data structures.
 *
 * Copyright IBM Corporation 2002, 2008
 */

/*
 * Driver authors:
 *            Martin Peschke (originator of the driver)
 *            Raimund Schroeder
 *            Aron Zeh
 *            Wolfgang Taphorn
 *            Stefan Bader
 *            Heiko Carstens (kernel 2.6 port of the driver)
 *            Andreas Herrmann
 *            Maxim Shchetynin
 *            Volker Sameske
 *            Ralph Wuerthner
 *            Michael Loehr
 *            Swen Schillig
 *            Christof Schmitt
 *            Martin Petermann
 *            Sven Schuetz
 */

#include <linux/miscdevice.h>
#include "zfcp_ext.h"

static char *device;
/*********************** FUNCTION PROTOTYPES *********************************/

/* written against the module interface */
static int __init  zfcp_module_init(void);

/*********************** KERNEL/MODULE PARAMETERS  ***************************/

/* declare driver module init/cleanup functions */
module_init(zfcp_module_init);

MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
MODULE_DESCRIPTION
    ("FCP (SCSI over Fibre Channel) HBA driver for IBM System z9 and zSeries");
MODULE_LICENSE("GPL");

module_param(device, charp, 0400);
MODULE_PARM_DESC(device, "specify initial device");

/****************************************************************/
/************** Functions without logging ***********************/
/****************************************************************/

void
_zfcp_hex_dump(char *addr, int count)
{
	int i;
	for (i = 0; i < count; i++) {
		printk("%02x", addr[i]);
		if ((i % 4) == 3)
			printk(" ");
		if ((i % 32) == 31)
			printk("\n");
	}
	if (((i-1) % 32) != 31)
		printk("\n");
}


/****************************************************************/
/****** Functions to handle the request ID hash table    ********/
/****************************************************************/

static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
{
	int idx;

	adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
				    GFP_KERNEL);
	if (!adapter->req_list)
		return -ENOMEM;

	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
		INIT_LIST_HEAD(&adapter->req_list[idx]);
	return 0;
}

static void zfcp_reqlist_free(struct zfcp_adapter *adapter)
{
	kfree(adapter->req_list);
}

int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
{
	unsigned int idx;

	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
		if (!list_empty(&adapter->req_list[idx]))
			return 0;
	return 1;
}

/****************************************************************/
/************** Uncategorised Functions *************************/
/****************************************************************/

/**
 * zfcp_device_setup - setup function
 * @str: pointer to parameter string
 *
 * Parse "device=..." parameter string.
 */
static int __init
zfcp_device_setup(char *devstr)
{
	char *tmp, *str;
	size_t len;

	if (!devstr)
		return 0;

	len = strlen(devstr) + 1;
	str = kmalloc(len, GFP_KERNEL);
	if (!str) {
		pr_err("zfcp: Could not allocate memory for "
		       "device parameter string, device not attached.\n");
		return 0;
	}
	memcpy(str, devstr, len);

	tmp = strchr(str, ',');
	if (!tmp)
		goto err_out;
	*tmp++ = '\0';
	strncpy(zfcp_data.init_busid, str, BUS_ID_SIZE);
	zfcp_data.init_busid[BUS_ID_SIZE-1] = '\0';

	zfcp_data.init_wwpn = simple_strtoull(tmp, &tmp, 0);
	if (*tmp++ != ',')
		goto err_out;
	if (*tmp == '\0')
		goto err_out;

	zfcp_data.init_fcp_lun = simple_strtoull(tmp, &tmp, 0);
	if (*tmp != '\0')
		goto err_out;
	kfree(str);
	return 1;

 err_out:
	pr_err("zfcp: Parse error for device parameter string %s, "
	       "device not attached.\n", str);
	kfree(str);
	return 0;
}

static void __init
zfcp_init_device_configure(void)
{
	struct zfcp_adapter *adapter;
	struct zfcp_port *port;
	struct zfcp_unit *unit;

	down(&zfcp_data.config_sema);
	read_lock_irq(&zfcp_data.config_lock);
	adapter = zfcp_get_adapter_by_busid(zfcp_data.init_busid);
	if (adapter)
		zfcp_adapter_get(adapter);
	read_unlock_irq(&zfcp_data.config_lock);

	if (adapter == NULL)
		goto out_adapter;
	port = zfcp_port_enqueue(adapter, zfcp_data.init_wwpn, 0, 0);
	if (!port)
		goto out_port;
	unit = zfcp_unit_enqueue(port, zfcp_data.init_fcp_lun);
	if (!unit)
		goto out_unit;
	up(&zfcp_data.config_sema);
	ccw_device_set_online(adapter->ccw_device);
	zfcp_erp_wait(adapter);
	down(&zfcp_data.config_sema);
	zfcp_unit_put(unit);
 out_unit:
	zfcp_port_put(port);
 out_port:
	zfcp_adapter_put(adapter);
 out_adapter:
	up(&zfcp_data.config_sema);
	return;
}

static int calc_alignment(int size)
{
	int align = 1;

	if (!size)
		return 0;

	while ((size - align) > 0)
		align <<= 1;

	return align;
}

static int __init
zfcp_module_init(void)
{
	int retval = -ENOMEM;
	int size, align;

	size = sizeof(struct zfcp_fsf_req_qtcb);
	align = calc_alignment(size);
	zfcp_data.fsf_req_qtcb_cache =
		kmem_cache_create("zfcp_fsf", size, align, 0, NULL);
	if (!zfcp_data.fsf_req_qtcb_cache)
		goto out;

	size = sizeof(struct fsf_status_read_buffer);
	align = calc_alignment(size);
	zfcp_data.sr_buffer_cache =
		kmem_cache_create("zfcp_sr", size, align, 0, NULL);
	if (!zfcp_data.sr_buffer_cache)
		goto out_sr_cache;

	size = sizeof(struct zfcp_gid_pn_data);
	align = calc_alignment(size);
	zfcp_data.gid_pn_cache =
		kmem_cache_create("zfcp_gid", size, align, 0, NULL);
	if (!zfcp_data.gid_pn_cache)
		goto out_gid_cache;

	/* initialize adapter list */
	INIT_LIST_HEAD(&zfcp_data.adapter_list_head);

	/* initialize adapters to be removed list head */
	INIT_LIST_HEAD(&zfcp_data.adapter_remove_lh);

	zfcp_data.scsi_transport_template =
		fc_attach_transport(&zfcp_transport_functions);
	if (!zfcp_data.scsi_transport_template)
		goto out_transport;

	retval = misc_register(&zfcp_cfdc_misc);
	if (retval != 0) {
		pr_err("zfcp: registration of misc device zfcp_cfdc failed\n");
		goto out_misc;
	}

	/* Initialise proc semaphores */
	sema_init(&zfcp_data.config_sema, 1);

	/* initialise configuration rw lock */
	rwlock_init(&zfcp_data.config_lock);

	/* setup dynamic I/O */
	retval = zfcp_ccw_register();
	if (retval) {
		pr_err("zfcp: Registration with common I/O layer failed.\n");
		goto out_ccw_register;
	}

	if (zfcp_device_setup(device))
		zfcp_init_device_configure();

	goto out;

 out_ccw_register:
	misc_deregister(&zfcp_cfdc_misc);
 out_misc:
	fc_release_transport(zfcp_data.scsi_transport_template);
 out_transport:
	kmem_cache_destroy(zfcp_data.gid_pn_cache);
 out_gid_cache:
	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 out_sr_cache:
	kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
 out:
	return retval;
}

/****************************************************************/
/****** Functions for configuration/set-up of structures ********/
/****************************************************************/

/**
 * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 * @port: pointer to port to search for unit
 * @fcp_lun: FCP LUN to search for
 * Traverse list of all units of a port and return pointer to a unit
 * with the given FCP LUN.
 */
struct zfcp_unit *
zfcp_get_unit_by_lun(struct zfcp_port *port, fcp_lun_t fcp_lun)
{
	struct zfcp_unit *unit;
	int found = 0;

	list_for_each_entry(unit, &port->unit_list_head, list) {
		if ((unit->fcp_lun == fcp_lun) &&
		    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status))
		{
			found = 1;
			break;
		}
	}
	return found ? unit : NULL;
}

/**
 * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 * @adapter: pointer to adapter to search for port
 * @wwpn: wwpn to search for
 * Traverse list of all ports of an adapter and return pointer to a port
 * with the given wwpn.
 */
struct zfcp_port *
zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter, wwn_t wwpn)
{
	struct zfcp_port *port;
	int found = 0;

	list_for_each_entry(port, &adapter->port_list_head, list) {
		if ((port->wwpn == wwpn) &&
		    !(atomic_read(&port->status) &
		      (ZFCP_STATUS_PORT_NO_WWPN | ZFCP_STATUS_COMMON_REMOVE))) {
			found = 1;
			break;
		}
	}
	return found ? port : NULL;
}

/**
 * zfcp_get_port_by_did - find port in port list of adapter by d_id
 * @adapter: pointer to adapter to search for port
 * @d_id: d_id to search for
 * Traverse list of all ports of an adapter and return pointer to a port
 * with the given d_id.
 */
struct zfcp_port *
zfcp_get_port_by_did(struct zfcp_adapter *adapter, u32 d_id)
{
	struct zfcp_port *port;
	int found = 0;

	list_for_each_entry(port, &adapter->port_list_head, list) {
		if ((port->d_id == d_id) &&
		    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status))
		{
			found = 1;
			break;
		}
	}
	return found ? port : NULL;
}

/**
 * zfcp_get_adapter_by_busid - find adpater in adapter list by bus_id
 * @bus_id: bus_id to search for
 * Traverse list of all adapters and return pointer to an adapter
 * with the given bus_id.
 */
struct zfcp_adapter *
zfcp_get_adapter_by_busid(char *bus_id)
{
	struct zfcp_adapter *adapter;
	int found = 0;

	list_for_each_entry(adapter, &zfcp_data.adapter_list_head, list) {
		if ((strncmp(bus_id, zfcp_get_busid_by_adapter(adapter),
			     BUS_ID_SIZE) == 0) &&
		    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE,
				      &adapter->status)){
			found = 1;
			break;
		}
	}
	return found ? adapter : NULL;
}

/**
 * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 * @port: pointer to port where unit is added
 * @fcp_lun: FCP LUN of unit to be enqueued
 * Return: pointer to enqueued unit on success, NULL on error
 * Locks: config_sema must be held to serialize changes to the unit list
 *
 * Sets up some unit internal structures and creates sysfs entry.
 */
struct zfcp_unit *
zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
{
	struct zfcp_unit *unit;

	/*
	 * check that there is no unit with this FCP_LUN already in list
	 * and enqueue it.
	 * Note: Unlike for the adapter and the port, this is an error
	 */
	read_lock_irq(&zfcp_data.config_lock);
	unit = zfcp_get_unit_by_lun(port, fcp_lun);
	read_unlock_irq(&zfcp_data.config_lock);
	if (unit)
		return NULL;

	unit = kzalloc(sizeof (struct zfcp_unit), GFP_KERNEL);
	if (!unit)
		return NULL;

	/* initialise reference count stuff */
	atomic_set(&unit->refcount, 0);
	init_waitqueue_head(&unit->remove_wq);

	unit->port = port;
	unit->fcp_lun = fcp_lun;

	/* setup for sysfs registration */
	snprintf(unit->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx", fcp_lun);
	unit->sysfs_device.parent = &port->sysfs_device;
	unit->sysfs_device.release = zfcp_sysfs_unit_release;
	dev_set_drvdata(&unit->sysfs_device, unit);

	/* mark unit unusable as long as sysfs registration is not complete */
	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);

	spin_lock_init(&unit->latencies.lock);
	unit->latencies.write.channel.min = 0xFFFFFFFF;
	unit->latencies.write.fabric.min = 0xFFFFFFFF;
	unit->latencies.read.channel.min = 0xFFFFFFFF;
	unit->latencies.read.fabric.min = 0xFFFFFFFF;
	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;

	if (device_register(&unit->sysfs_device)) {
		kfree(unit);
		return NULL;
	}

	if (zfcp_sysfs_unit_create_files(&unit->sysfs_device)) {
		device_unregister(&unit->sysfs_device);
		return NULL;
	}

	zfcp_unit_get(unit);
	unit->scsi_lun = scsilun_to_int((struct scsi_lun *)&unit->fcp_lun);

	write_lock_irq(&zfcp_data.config_lock);
	list_add_tail(&unit->list, &port->unit_list_head);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
	write_unlock_irq(&zfcp_data.config_lock);

	port->units++;
	zfcp_port_get(port);

	return unit;
}

void
zfcp_unit_dequeue(struct zfcp_unit *unit)
{
	zfcp_unit_wait(unit);
	write_lock_irq(&zfcp_data.config_lock);
	list_del(&unit->list);
	write_unlock_irq(&zfcp_data.config_lock);
	unit->port->units--;
	zfcp_port_put(unit->port);
	zfcp_sysfs_unit_remove_files(&unit->sysfs_device);
	device_unregister(&unit->sysfs_device);
}

/*
 * Allocates a combined QTCB/fsf_req buffer for erp actions and fcp/SCSI
 * commands.
 * It also genrates fcp-nameserver request/response buffer and unsolicited
 * status read fsf_req buffers.
 *
 * locks:       must only be called with zfcp_data.config_sema taken
 */
static int
zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
{
	adapter->pool.fsf_req_erp =
		mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_ERP_NR,
					 zfcp_data.fsf_req_qtcb_cache);
	if (!adapter->pool.fsf_req_erp)
		return -ENOMEM;

	adapter->pool.fsf_req_scsi =
		mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_SCSI_NR,
					 zfcp_data.fsf_req_qtcb_cache);
	if (!adapter->pool.fsf_req_scsi)
		return -ENOMEM;

	adapter->pool.fsf_req_abort =
		mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_ABORT_NR,
					 zfcp_data.fsf_req_qtcb_cache);
	if (!adapter->pool.fsf_req_abort)
		return -ENOMEM;

	adapter->pool.fsf_req_status_read =
		mempool_create_kmalloc_pool(ZFCP_POOL_STATUS_READ_NR,
					    sizeof(struct zfcp_fsf_req));
	if (!adapter->pool.fsf_req_status_read)
		return -ENOMEM;

	adapter->pool.data_status_read =
		mempool_create_slab_pool(ZFCP_POOL_STATUS_READ_NR,
					 zfcp_data.sr_buffer_cache);
	if (!adapter->pool.data_status_read)
		return -ENOMEM;

	adapter->pool.data_gid_pn =
		mempool_create_slab_pool(ZFCP_POOL_DATA_GID_PN_NR,
					 zfcp_data.gid_pn_cache);
	if (!adapter->pool.data_gid_pn)
		return -ENOMEM;

	return 0;
}

/**
 * zfcp_free_low_mem_buffers - free memory pools of an adapter
 * @adapter: pointer to zfcp_adapter for which memory pools should be freed
 * locking:  zfcp_data.config_sema must be held
 */
static void
zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
{
	if (adapter->pool.fsf_req_erp)
		mempool_destroy(adapter->pool.fsf_req_erp);
	if (adapter->pool.fsf_req_scsi)
		mempool_destroy(adapter->pool.fsf_req_scsi);
	if (adapter->pool.fsf_req_abort)
		mempool_destroy(adapter->pool.fsf_req_abort);
	if (adapter->pool.fsf_req_status_read)
		mempool_destroy(adapter->pool.fsf_req_status_read);
	if (adapter->pool.data_status_read)
		mempool_destroy(adapter->pool.data_status_read);
	if (adapter->pool.data_gid_pn)
		mempool_destroy(adapter->pool.data_gid_pn);
}

static void zfcp_dummy_release(struct device *dev)
{
	return;
}

int zfcp_status_read_refill(struct zfcp_adapter *adapter)
{
	while (atomic_read(&adapter->stat_miss) > 0)
		if (zfcp_fsf_status_read(adapter, ZFCP_WAIT_FOR_SBAL))
			break;
	else
		atomic_dec(&adapter->stat_miss);

	if (ZFCP_STATUS_READS_RECOM <= atomic_read(&adapter->stat_miss)) {
		zfcp_erp_adapter_reopen(adapter, 0, 103, NULL);
		return 1;
	}
	return 0;
}

static void _zfcp_status_read_scheduler(struct work_struct *work)
{
	zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
					     stat_work));
}

static int zfcp_nameserver_enqueue(struct zfcp_adapter *adapter)
{
	struct zfcp_port *port;

	port = zfcp_port_enqueue(adapter, 0, ZFCP_STATUS_PORT_WKA,
				 ZFCP_DID_DIRECTORY_SERVICE);
	if (!port)
		return -ENXIO;
	zfcp_port_put(port);

	return 0;
}

/*
 * Enqueues an adapter at the end of the adapter list in the driver data.
 * All adapter internal structures are set up.
 * Proc-fs entries are also created.
 *
 * FIXME: Use -ENOMEM as return code for allocation failures
 *
 * returns:	0             if a new adapter was successfully enqueued
 *              ZFCP_KNOWN    if an adapter with this devno was already present
 *		-ENOMEM       if alloc failed
 * locks:	config_sema must be held to serialise changes to the adapter list
 */
struct zfcp_adapter *
zfcp_adapter_enqueue(struct ccw_device *ccw_device)
{
	struct zfcp_adapter *adapter;

	/*
	 * Note: It is safe to release the list_lock, as any list changes
	 * are protected by the config_sema, which must be held to get here
	 */

	/* try to allocate new adapter data structure (zeroed) */
	adapter = kzalloc(sizeof (struct zfcp_adapter), GFP_KERNEL);
	if (!adapter)
		goto out;

	ccw_device->handler = NULL;

	/* save ccw_device pointer */
	adapter->ccw_device = ccw_device;

	if (zfcp_qdio_allocate(adapter))
		goto qdio_allocate_failed;

	if (zfcp_allocate_low_mem_buffers(adapter))
		goto failed_low_mem_buffers;

	/* initialise reference count stuff */
	atomic_set(&adapter->refcount, 0);
	init_waitqueue_head(&adapter->remove_wq);

	/* initialise list of ports */
	INIT_LIST_HEAD(&adapter->port_list_head);

	/* initialise list of ports to be removed */
	INIT_LIST_HEAD(&adapter->port_remove_lh);

	/* initialize list of fsf requests */
	spin_lock_init(&adapter->req_list_lock);
	if (zfcp_reqlist_alloc(adapter))
		goto failed_low_mem_buffers;

	/* initialize debug locks */

	spin_lock_init(&adapter->hba_dbf_lock);
	spin_lock_init(&adapter->san_dbf_lock);
	spin_lock_init(&adapter->scsi_dbf_lock);
	spin_lock_init(&adapter->rec_dbf_lock);

	if (zfcp_adapter_debug_register(adapter))
		goto debug_register_failed;

	/* initialize error recovery stuff */

	rwlock_init(&adapter->erp_lock);
	sema_init(&adapter->erp_ready_sem, 0);
	INIT_LIST_HEAD(&adapter->erp_ready_head);
	INIT_LIST_HEAD(&adapter->erp_running_head);

	/* initialize abort lock */
	rwlock_init(&adapter->abort_lock);

	/* initialise some erp stuff */
	init_waitqueue_head(&adapter->erp_thread_wqh);
	init_waitqueue_head(&adapter->erp_done_wqh);

	/* initialize lock of associated request queue */
	rwlock_init(&adapter->req_q.lock);
	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
	INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);

	/* mark adapter unusable as long as sysfs registration is not complete */
	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);

	dev_set_drvdata(&ccw_device->dev, adapter);

	if (zfcp_sysfs_adapter_create_files(&ccw_device->dev))
		goto sysfs_failed;

	adapter->generic_services.parent = &adapter->ccw_device->dev;
	adapter->generic_services.release = zfcp_dummy_release;
	snprintf(adapter->generic_services.bus_id, BUS_ID_SIZE,
		 "generic_services");

	if (device_register(&adapter->generic_services))
		goto generic_services_failed;

	/* put allocated adapter at list tail */
	write_lock_irq(&zfcp_data.config_lock);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
	list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
	write_unlock_irq(&zfcp_data.config_lock);

	zfcp_data.adapters++;

	zfcp_nameserver_enqueue(adapter);

	goto out;

 generic_services_failed:
	zfcp_sysfs_adapter_remove_files(&adapter->ccw_device->dev);
 sysfs_failed:
	zfcp_adapter_debug_unregister(adapter);
 debug_register_failed:
	dev_set_drvdata(&ccw_device->dev, NULL);
	zfcp_reqlist_free(adapter);
 failed_low_mem_buffers:
	zfcp_free_low_mem_buffers(adapter);
 qdio_allocate_failed:
	zfcp_qdio_free(adapter);
	kfree(adapter);
	adapter = NULL;
 out:
	return adapter;
}

/*
 * returns:	0 - struct zfcp_adapter  data structure successfully removed
 *		!0 - struct zfcp_adapter  data structure could not be removed
 *			(e.g. still used)
 * locks:	adapter list write lock is assumed to be held by caller
 */
void
zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
{
	int retval = 0;
	unsigned long flags;

	cancel_work_sync(&adapter->scan_work);
	cancel_work_sync(&adapter->stat_work);
	zfcp_adapter_scsi_unregister(adapter);
	device_unregister(&adapter->generic_services);
	zfcp_sysfs_adapter_remove_files(&adapter->ccw_device->dev);
	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
	/* sanity check: no pending FSF requests */
	spin_lock_irqsave(&adapter->req_list_lock, flags);
	retval = zfcp_reqlist_isempty(adapter);
	spin_unlock_irqrestore(&adapter->req_list_lock, flags);
	if (!retval) {
		retval = -EBUSY;
		goto out;
	}

	zfcp_adapter_debug_unregister(adapter);

	/* remove specified adapter data structure from list */
	write_lock_irq(&zfcp_data.config_lock);
	list_del(&adapter->list);
	write_unlock_irq(&zfcp_data.config_lock);

	/* decrease number of adapters in list */
	zfcp_data.adapters--;

	zfcp_qdio_free(adapter);

	zfcp_free_low_mem_buffers(adapter);
	zfcp_reqlist_free(adapter);
	kfree(adapter->fc_stats);
	kfree(adapter->stats_reset_data);
	kfree(adapter);
 out:
	return;
}

/**
 * zfcp_port_enqueue - enqueue port to port list of adapter
 * @adapter: adapter where remote port is added
 * @wwpn: WWPN of the remote port to be enqueued
 * @status: initial status for the port
 * @d_id: destination id of the remote port to be enqueued
 * Return: pointer to enqueued port on success, NULL on error
 * Locks: config_sema must be held to serialize changes to the port list
 *
 * All port internal structures are set up and the sysfs entry is generated.
 * d_id is used to enqueue ports with a well known address like the Directory
 * Service for nameserver lookup.
 */
struct zfcp_port *
zfcp_port_enqueue(struct zfcp_adapter *adapter, wwn_t wwpn, u32 status,
		  u32 d_id)
{
	struct zfcp_port *port;
	int check_wwpn;

	check_wwpn = !(status & ZFCP_STATUS_PORT_NO_WWPN);
	/*
	 * check that there is no port with this WWPN already in list
	 */
	if (check_wwpn) {
		read_lock_irq(&zfcp_data.config_lock);
		port = zfcp_get_port_by_wwpn(adapter, wwpn);
		read_unlock_irq(&zfcp_data.config_lock);
		if (port)
			return NULL;
	}

	port = kzalloc(sizeof (struct zfcp_port), GFP_KERNEL);
	if (!port)
		return NULL;

	/* initialise reference count stuff */
	atomic_set(&port->refcount, 0);
	init_waitqueue_head(&port->remove_wq);

	INIT_LIST_HEAD(&port->unit_list_head);
	INIT_LIST_HEAD(&port->unit_remove_lh);

	port->adapter = adapter;

	if (check_wwpn)
		port->wwpn = wwpn;

	atomic_set_mask(status, &port->status);

	/* setup for sysfs registration */
	if (status & ZFCP_STATUS_PORT_WKA) {
		switch (d_id) {
		case ZFCP_DID_DIRECTORY_SERVICE:
			snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
				 "directory");
			break;
		case ZFCP_DID_MANAGEMENT_SERVICE:
			snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
				 "management");
			break;
		case ZFCP_DID_KEY_DISTRIBUTION_SERVICE:
			snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
				 "key_distribution");
			break;
		case ZFCP_DID_ALIAS_SERVICE:
			snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
				 "alias");
			break;
		case ZFCP_DID_TIME_SERVICE:
			snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
				 "time");
			break;
		default:
			kfree(port);
			return NULL;
		}
		port->sysfs_device.parent = &adapter->generic_services;
	} else {
		snprintf(port->sysfs_device.bus_id,
			 BUS_ID_SIZE, "0x%016llx", wwpn);
		port->sysfs_device.parent = &adapter->ccw_device->dev;
	}

	port->d_id = d_id;

	port->sysfs_device.release = zfcp_sysfs_port_release;
	dev_set_drvdata(&port->sysfs_device, port);

	/* mark port unusable as long as sysfs registration is not complete */
	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);

	if (device_register(&port->sysfs_device)) {
		kfree(port);
		return NULL;
	}

	if (zfcp_sysfs_port_create_files(&port->sysfs_device, status)) {
		device_unregister(&port->sysfs_device);
		return NULL;
	}

	zfcp_port_get(port);

	write_lock_irq(&zfcp_data.config_lock);
	list_add_tail(&port->list, &adapter->port_list_head);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
	if (d_id == ZFCP_DID_DIRECTORY_SERVICE)
		if (!adapter->nameserver_port)
			adapter->nameserver_port = port;
	adapter->ports++;
	write_unlock_irq(&zfcp_data.config_lock);

	zfcp_adapter_get(adapter);

	return port;
}

void
zfcp_port_dequeue(struct zfcp_port *port)
{
	zfcp_port_wait(port);
	write_lock_irq(&zfcp_data.config_lock);
	list_del(&port->list);
	port->adapter->ports--;
	write_unlock_irq(&zfcp_data.config_lock);
	if (port->rport)
		fc_remote_port_delete(port->rport);
	port->rport = NULL;
	zfcp_adapter_put(port->adapter);
	zfcp_sysfs_port_remove_files(&port->sysfs_device,
				     atomic_read(&port->status));
	device_unregister(&port->sysfs_device);
}

void zfcp_sg_free_table(struct scatterlist *sg, int count)
{
	int i;

	for (i = 0; i < count; i++, sg++)
		if (sg)
			free_page((unsigned long) sg_virt(sg));
		else
			break;
}

int zfcp_sg_setup_table(struct scatterlist *sg, int count)
{
	void *addr;
	int i;

	sg_init_table(sg, count);
	for (i = 0; i < count; i++, sg++) {
		addr = (void *) get_zeroed_page(GFP_KERNEL);
		if (!addr) {
			zfcp_sg_free_table(sg, i);
			return -ENOMEM;
		}
		sg_set_buf(sg, addr, PAGE_SIZE);
	}
	return 0;
}