xref: /linux/drivers/s390/scsi/zfcp_aux.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  * zfcp device driver
3  *
4  * Module interface and handling of zfcp data structures.
5  *
6  * Copyright IBM Corporation 2002, 2008
7  */
8 
9 /*
10  * Driver authors:
11  *            Martin Peschke (originator of the driver)
12  *            Raimund Schroeder
13  *            Aron Zeh
14  *            Wolfgang Taphorn
15  *            Stefan Bader
16  *            Heiko Carstens (kernel 2.6 port of the driver)
17  *            Andreas Herrmann
18  *            Maxim Shchetynin
19  *            Volker Sameske
20  *            Ralph Wuerthner
21  *            Michael Loehr
22  *            Swen Schillig
23  *            Christof Schmitt
24  *            Martin Petermann
25  *            Sven Schuetz
26  */
27 
28 #include <linux/miscdevice.h>
29 #include "zfcp_ext.h"
30 
31 static char *device;
32 
33 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
34 MODULE_DESCRIPTION("FCP HBA driver");
35 MODULE_LICENSE("GPL");
36 
37 module_param(device, charp, 0400);
38 MODULE_PARM_DESC(device, "specify initial device");
39 
40 static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
41 {
42 	int idx;
43 
44 	adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
45 				    GFP_KERNEL);
46 	if (!adapter->req_list)
47 		return -ENOMEM;
48 
49 	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
50 		INIT_LIST_HEAD(&adapter->req_list[idx]);
51 	return 0;
52 }
53 
54 /**
55  * zfcp_reqlist_isempty - is the request list empty
56  * @adapter: pointer to struct zfcp_adapter
57  *
58  * Returns: true if list is empty, false otherwise
59  */
60 int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
61 {
62 	unsigned int idx;
63 
64 	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
65 		if (!list_empty(&adapter->req_list[idx]))
66 			return 0;
67 	return 1;
68 }
69 
70 static int __init zfcp_device_setup(char *devstr)
71 {
72 	char *token;
73 	char *str;
74 
75 	if (!devstr)
76 		return 0;
77 
78 	/* duplicate devstr and keep the original for sysfs presentation*/
79 	str = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
80 	if (!str)
81 		return 0;
82 
83 	strcpy(str, devstr);
84 
85 	token = strsep(&str, ",");
86 	if (!token || strlen(token) >= BUS_ID_SIZE)
87 		goto err_out;
88 	strncpy(zfcp_data.init_busid, token, BUS_ID_SIZE);
89 
90 	token = strsep(&str, ",");
91 	if (!token || strict_strtoull(token, 0,
92 				(unsigned long long *) &zfcp_data.init_wwpn))
93 		goto err_out;
94 
95 	token = strsep(&str, ",");
96 	if (!token || strict_strtoull(token, 0,
97 				(unsigned long long *) &zfcp_data.init_fcp_lun))
98 		goto err_out;
99 
100 	kfree(str);
101 	return 1;
102 
103  err_out:
104 	kfree(str);
105 	pr_err("zfcp: %s is not a valid SCSI device\n", devstr);
106 	return 0;
107 }
108 
109 static void __init zfcp_init_device_configure(void)
110 {
111 	struct zfcp_adapter *adapter;
112 	struct zfcp_port *port;
113 	struct zfcp_unit *unit;
114 
115 	down(&zfcp_data.config_sema);
116 	read_lock_irq(&zfcp_data.config_lock);
117 	adapter = zfcp_get_adapter_by_busid(zfcp_data.init_busid);
118 	if (adapter)
119 		zfcp_adapter_get(adapter);
120 	read_unlock_irq(&zfcp_data.config_lock);
121 
122 	if (!adapter)
123 		goto out_adapter;
124 	port = zfcp_port_enqueue(adapter, zfcp_data.init_wwpn, 0, 0);
125 	if (IS_ERR(port))
126 		goto out_port;
127 	unit = zfcp_unit_enqueue(port, zfcp_data.init_fcp_lun);
128 	if (IS_ERR(unit))
129 		goto out_unit;
130 	up(&zfcp_data.config_sema);
131 	ccw_device_set_online(adapter->ccw_device);
132 
133 	zfcp_erp_wait(adapter);
134 	wait_event(adapter->erp_done_wqh,
135 		   !(atomic_read(&unit->status) &
136 				ZFCP_STATUS_UNIT_SCSI_WORK_PENDING));
137 
138 	down(&zfcp_data.config_sema);
139 	zfcp_unit_put(unit);
140 out_unit:
141 	zfcp_port_put(port);
142 out_port:
143 	zfcp_adapter_put(adapter);
144 out_adapter:
145 	up(&zfcp_data.config_sema);
146 	return;
147 }
148 
149 static struct kmem_cache *zfcp_cache_create(int size, char *name)
150 {
151 	int align = 1;
152 	while ((size - align) > 0)
153 		align <<= 1;
154 	return kmem_cache_create(name , size, align, 0, NULL);
155 }
156 
157 static int __init zfcp_module_init(void)
158 {
159 	int retval = -ENOMEM;
160 
161 	zfcp_data.fsf_req_qtcb_cache = zfcp_cache_create(
162 			sizeof(struct zfcp_fsf_req_qtcb), "zfcp_fsf");
163 	if (!zfcp_data.fsf_req_qtcb_cache)
164 		goto out;
165 
166 	zfcp_data.sr_buffer_cache = zfcp_cache_create(
167 			sizeof(struct fsf_status_read_buffer), "zfcp_sr");
168 	if (!zfcp_data.sr_buffer_cache)
169 		goto out_sr_cache;
170 
171 	zfcp_data.gid_pn_cache = zfcp_cache_create(
172 			sizeof(struct zfcp_gid_pn_data), "zfcp_gid");
173 	if (!zfcp_data.gid_pn_cache)
174 		goto out_gid_cache;
175 
176 	zfcp_data.work_queue = create_singlethread_workqueue("zfcp_wq");
177 
178 	INIT_LIST_HEAD(&zfcp_data.adapter_list_head);
179 	sema_init(&zfcp_data.config_sema, 1);
180 	rwlock_init(&zfcp_data.config_lock);
181 
182 	zfcp_data.scsi_transport_template =
183 		fc_attach_transport(&zfcp_transport_functions);
184 	if (!zfcp_data.scsi_transport_template)
185 		goto out_transport;
186 
187 	retval = misc_register(&zfcp_cfdc_misc);
188 	if (retval) {
189 		pr_err("zfcp: Registering the misc device zfcp_cfdc failed\n");
190 		goto out_misc;
191 	}
192 
193 	retval = zfcp_ccw_register();
194 	if (retval) {
195 		pr_err("zfcp: The zfcp device driver could not register with "
196 		       "the common I/O layer\n");
197 		goto out_ccw_register;
198 	}
199 
200 	if (zfcp_device_setup(device))
201 		zfcp_init_device_configure();
202 
203 	goto out;
204 
205 out_ccw_register:
206 	misc_deregister(&zfcp_cfdc_misc);
207 out_misc:
208 	fc_release_transport(zfcp_data.scsi_transport_template);
209 out_transport:
210 	kmem_cache_destroy(zfcp_data.gid_pn_cache);
211 out_gid_cache:
212 	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
213 out_sr_cache:
214 	kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
215 out:
216 	return retval;
217 }
218 
219 module_init(zfcp_module_init);
220 
221 /**
222  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
223  * @port: pointer to port to search for unit
224  * @fcp_lun: FCP LUN to search for
225  *
226  * Returns: pointer to zfcp_unit or NULL
227  */
228 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
229 {
230 	struct zfcp_unit *unit;
231 
232 	list_for_each_entry(unit, &port->unit_list_head, list)
233 		if ((unit->fcp_lun == fcp_lun) &&
234 		    !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE))
235 		    return unit;
236 	return NULL;
237 }
238 
239 /**
240  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
241  * @adapter: pointer to adapter to search for port
242  * @wwpn: wwpn to search for
243  *
244  * Returns: pointer to zfcp_port or NULL
245  */
246 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
247 					u64 wwpn)
248 {
249 	struct zfcp_port *port;
250 
251 	list_for_each_entry(port, &adapter->port_list_head, list)
252 		if ((port->wwpn == wwpn) && !(atomic_read(&port->status) &
253 		      (ZFCP_STATUS_PORT_NO_WWPN | ZFCP_STATUS_COMMON_REMOVE)))
254 			return port;
255 	return NULL;
256 }
257 
258 static void zfcp_sysfs_unit_release(struct device *dev)
259 {
260 	kfree(container_of(dev, struct zfcp_unit, sysfs_device));
261 }
262 
263 /**
264  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
265  * @port: pointer to port where unit is added
266  * @fcp_lun: FCP LUN of unit to be enqueued
267  * Returns: pointer to enqueued unit on success, ERR_PTR on error
268  * Locks: config_sema must be held to serialize changes to the unit list
269  *
270  * Sets up some unit internal structures and creates sysfs entry.
271  */
272 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
273 {
274 	struct zfcp_unit *unit;
275 
276 	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
277 	if (!unit)
278 		return ERR_PTR(-ENOMEM);
279 
280 	atomic_set(&unit->refcount, 0);
281 	init_waitqueue_head(&unit->remove_wq);
282 
283 	unit->port = port;
284 	unit->fcp_lun = fcp_lun;
285 
286 	dev_set_name(&unit->sysfs_device, "0x%016llx",
287 		     (unsigned long long) fcp_lun);
288 	unit->sysfs_device.parent = &port->sysfs_device;
289 	unit->sysfs_device.release = zfcp_sysfs_unit_release;
290 	dev_set_drvdata(&unit->sysfs_device, unit);
291 
292 	/* mark unit unusable as long as sysfs registration is not complete */
293 	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
294 
295 	spin_lock_init(&unit->latencies.lock);
296 	unit->latencies.write.channel.min = 0xFFFFFFFF;
297 	unit->latencies.write.fabric.min = 0xFFFFFFFF;
298 	unit->latencies.read.channel.min = 0xFFFFFFFF;
299 	unit->latencies.read.fabric.min = 0xFFFFFFFF;
300 	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
301 	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
302 
303 	read_lock_irq(&zfcp_data.config_lock);
304 	if (zfcp_get_unit_by_lun(port, fcp_lun)) {
305 		read_unlock_irq(&zfcp_data.config_lock);
306 		goto err_out_free;
307 	}
308 	read_unlock_irq(&zfcp_data.config_lock);
309 
310 	if (device_register(&unit->sysfs_device))
311 		goto err_out_free;
312 
313 	if (sysfs_create_group(&unit->sysfs_device.kobj,
314 			       &zfcp_sysfs_unit_attrs)) {
315 		device_unregister(&unit->sysfs_device);
316 		return ERR_PTR(-EIO);
317 	}
318 
319 	zfcp_unit_get(unit);
320 
321 	write_lock_irq(&zfcp_data.config_lock);
322 	list_add_tail(&unit->list, &port->unit_list_head);
323 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
324 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
325 
326 	write_unlock_irq(&zfcp_data.config_lock);
327 
328 	zfcp_port_get(port);
329 
330 	return unit;
331 
332 err_out_free:
333 	kfree(unit);
334 	return ERR_PTR(-EINVAL);
335 }
336 
337 /**
338  * zfcp_unit_dequeue - dequeue unit
339  * @unit: pointer to zfcp_unit
340  *
341  * waits until all work is done on unit and removes it then from the unit->list
342  * of the associated port.
343  */
344 void zfcp_unit_dequeue(struct zfcp_unit *unit)
345 {
346 	wait_event(unit->remove_wq, atomic_read(&unit->refcount) == 0);
347 	write_lock_irq(&zfcp_data.config_lock);
348 	list_del(&unit->list);
349 	write_unlock_irq(&zfcp_data.config_lock);
350 	zfcp_port_put(unit->port);
351 	sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
352 	device_unregister(&unit->sysfs_device);
353 }
354 
355 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
356 {
357 	/* must only be called with zfcp_data.config_sema taken */
358 	adapter->pool.fsf_req_erp =
359 		mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
360 	if (!adapter->pool.fsf_req_erp)
361 		return -ENOMEM;
362 
363 	adapter->pool.fsf_req_scsi =
364 		mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
365 	if (!adapter->pool.fsf_req_scsi)
366 		return -ENOMEM;
367 
368 	adapter->pool.fsf_req_abort =
369 		mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
370 	if (!adapter->pool.fsf_req_abort)
371 		return -ENOMEM;
372 
373 	adapter->pool.fsf_req_status_read =
374 		mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
375 					    sizeof(struct zfcp_fsf_req));
376 	if (!adapter->pool.fsf_req_status_read)
377 		return -ENOMEM;
378 
379 	adapter->pool.data_status_read =
380 		mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
381 					 zfcp_data.sr_buffer_cache);
382 	if (!adapter->pool.data_status_read)
383 		return -ENOMEM;
384 
385 	adapter->pool.data_gid_pn =
386 		mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
387 	if (!adapter->pool.data_gid_pn)
388 		return -ENOMEM;
389 
390 	return 0;
391 }
392 
393 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
394 {
395 	/* zfcp_data.config_sema must be held */
396 	if (adapter->pool.fsf_req_erp)
397 		mempool_destroy(adapter->pool.fsf_req_erp);
398 	if (adapter->pool.fsf_req_scsi)
399 		mempool_destroy(adapter->pool.fsf_req_scsi);
400 	if (adapter->pool.fsf_req_abort)
401 		mempool_destroy(adapter->pool.fsf_req_abort);
402 	if (adapter->pool.fsf_req_status_read)
403 		mempool_destroy(adapter->pool.fsf_req_status_read);
404 	if (adapter->pool.data_status_read)
405 		mempool_destroy(adapter->pool.data_status_read);
406 	if (adapter->pool.data_gid_pn)
407 		mempool_destroy(adapter->pool.data_gid_pn);
408 }
409 
410 /**
411  * zfcp_status_read_refill - refill the long running status_read_requests
412  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
413  *
414  * Returns: 0 on success, 1 otherwise
415  *
416  * if there are 16 or more status_read requests missing an adapter_reopen
417  * is triggered
418  */
419 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
420 {
421 	while (atomic_read(&adapter->stat_miss) > 0)
422 		if (zfcp_fsf_status_read(adapter)) {
423 			if (atomic_read(&adapter->stat_miss) >= 16) {
424 				zfcp_erp_adapter_reopen(adapter, 0, 103, NULL);
425 				return 1;
426 			}
427 			break;
428 		} else
429 			atomic_dec(&adapter->stat_miss);
430 	return 0;
431 }
432 
433 static void _zfcp_status_read_scheduler(struct work_struct *work)
434 {
435 	zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
436 					     stat_work));
437 }
438 
439 /**
440  * zfcp_adapter_enqueue - enqueue a new adapter to the list
441  * @ccw_device: pointer to the struct cc_device
442  *
443  * Returns:	0             if a new adapter was successfully enqueued
444  *		-ENOMEM       if alloc failed
445  * Enqueues an adapter at the end of the adapter list in the driver data.
446  * All adapter internal structures are set up.
447  * Proc-fs entries are also created.
448  * locks:	config_sema must be held to serialise changes to the adapter list
449  */
450 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
451 {
452 	struct zfcp_adapter *adapter;
453 
454 	/*
455 	 * Note: It is safe to release the list_lock, as any list changes
456 	 * are protected by the config_sema, which must be held to get here
457 	 */
458 
459 	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
460 	if (!adapter)
461 		return -ENOMEM;
462 
463 	ccw_device->handler = NULL;
464 	adapter->ccw_device = ccw_device;
465 	atomic_set(&adapter->refcount, 0);
466 
467 	if (zfcp_qdio_allocate(adapter))
468 		goto qdio_allocate_failed;
469 
470 	if (zfcp_allocate_low_mem_buffers(adapter))
471 		goto failed_low_mem_buffers;
472 
473 	if (zfcp_reqlist_alloc(adapter))
474 		goto failed_low_mem_buffers;
475 
476 	if (zfcp_adapter_debug_register(adapter))
477 		goto debug_register_failed;
478 
479 	init_waitqueue_head(&adapter->remove_wq);
480 	init_waitqueue_head(&adapter->erp_thread_wqh);
481 	init_waitqueue_head(&adapter->erp_done_wqh);
482 
483 	INIT_LIST_HEAD(&adapter->port_list_head);
484 	INIT_LIST_HEAD(&adapter->erp_ready_head);
485 	INIT_LIST_HEAD(&adapter->erp_running_head);
486 
487 	spin_lock_init(&adapter->req_list_lock);
488 
489 	spin_lock_init(&adapter->hba_dbf_lock);
490 	spin_lock_init(&adapter->san_dbf_lock);
491 	spin_lock_init(&adapter->scsi_dbf_lock);
492 	spin_lock_init(&adapter->rec_dbf_lock);
493 	spin_lock_init(&adapter->req_q_lock);
494 
495 	rwlock_init(&adapter->erp_lock);
496 	rwlock_init(&adapter->abort_lock);
497 
498 	sema_init(&adapter->erp_ready_sem, 0);
499 
500 	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
501 	INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);
502 
503 	/* mark adapter unusable as long as sysfs registration is not complete */
504 	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
505 
506 	dev_set_drvdata(&ccw_device->dev, adapter);
507 
508 	if (sysfs_create_group(&ccw_device->dev.kobj,
509 			       &zfcp_sysfs_adapter_attrs))
510 		goto sysfs_failed;
511 
512 	write_lock_irq(&zfcp_data.config_lock);
513 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
514 	list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
515 	write_unlock_irq(&zfcp_data.config_lock);
516 
517 	zfcp_fc_nameserver_init(adapter);
518 
519 	return 0;
520 
521 sysfs_failed:
522 	zfcp_adapter_debug_unregister(adapter);
523 debug_register_failed:
524 	dev_set_drvdata(&ccw_device->dev, NULL);
525 	kfree(adapter->req_list);
526 failed_low_mem_buffers:
527 	zfcp_free_low_mem_buffers(adapter);
528 qdio_allocate_failed:
529 	zfcp_qdio_free(adapter);
530 	kfree(adapter);
531 	return -ENOMEM;
532 }
533 
534 /**
535  * zfcp_adapter_dequeue - remove the adapter from the resource list
536  * @adapter: pointer to struct zfcp_adapter which should be removed
537  * locks:	adapter list write lock is assumed to be held by caller
538  */
539 void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
540 {
541 	int retval = 0;
542 	unsigned long flags;
543 
544 	cancel_work_sync(&adapter->scan_work);
545 	cancel_work_sync(&adapter->stat_work);
546 	zfcp_adapter_scsi_unregister(adapter);
547 	sysfs_remove_group(&adapter->ccw_device->dev.kobj,
548 			   &zfcp_sysfs_adapter_attrs);
549 	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
550 	/* sanity check: no pending FSF requests */
551 	spin_lock_irqsave(&adapter->req_list_lock, flags);
552 	retval = zfcp_reqlist_isempty(adapter);
553 	spin_unlock_irqrestore(&adapter->req_list_lock, flags);
554 	if (!retval)
555 		return;
556 
557 	zfcp_adapter_debug_unregister(adapter);
558 
559 	/* remove specified adapter data structure from list */
560 	write_lock_irq(&zfcp_data.config_lock);
561 	list_del(&adapter->list);
562 	write_unlock_irq(&zfcp_data.config_lock);
563 
564 	zfcp_qdio_free(adapter);
565 
566 	zfcp_free_low_mem_buffers(adapter);
567 	kfree(adapter->req_list);
568 	kfree(adapter->fc_stats);
569 	kfree(adapter->stats_reset_data);
570 	kfree(adapter);
571 }
572 
573 static void zfcp_sysfs_port_release(struct device *dev)
574 {
575 	kfree(container_of(dev, struct zfcp_port, sysfs_device));
576 }
577 
578 /**
579  * zfcp_port_enqueue - enqueue port to port list of adapter
580  * @adapter: adapter where remote port is added
581  * @wwpn: WWPN of the remote port to be enqueued
582  * @status: initial status for the port
583  * @d_id: destination id of the remote port to be enqueued
584  * Returns: pointer to enqueued port on success, ERR_PTR on error
585  * Locks: config_sema must be held to serialize changes to the port list
586  *
587  * All port internal structures are set up and the sysfs entry is generated.
588  * d_id is used to enqueue ports with a well known address like the Directory
589  * Service for nameserver lookup.
590  */
591 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
592 				     u32 status, u32 d_id)
593 {
594 	struct zfcp_port *port;
595 	int retval;
596 
597 	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
598 	if (!port)
599 		return ERR_PTR(-ENOMEM);
600 
601 	init_waitqueue_head(&port->remove_wq);
602 	INIT_LIST_HEAD(&port->unit_list_head);
603 	INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);
604 
605 	port->adapter = adapter;
606 	port->d_id = d_id;
607 	port->wwpn = wwpn;
608 
609 	/* mark port unusable as long as sysfs registration is not complete */
610 	atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
611 	atomic_set(&port->refcount, 0);
612 
613 	dev_set_name(&port->sysfs_device, "0x%016llx", wwpn);
614 	port->sysfs_device.parent = &adapter->ccw_device->dev;
615 
616 	port->sysfs_device.release = zfcp_sysfs_port_release;
617 	dev_set_drvdata(&port->sysfs_device, port);
618 
619 	read_lock_irq(&zfcp_data.config_lock);
620 	if (!(status & ZFCP_STATUS_PORT_NO_WWPN))
621 		if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
622 			read_unlock_irq(&zfcp_data.config_lock);
623 			goto err_out_free;
624 		}
625 	read_unlock_irq(&zfcp_data.config_lock);
626 
627 	if (device_register(&port->sysfs_device))
628 		goto err_out_free;
629 
630 	retval = sysfs_create_group(&port->sysfs_device.kobj,
631 				    &zfcp_sysfs_port_attrs);
632 
633 	if (retval) {
634 		device_unregister(&port->sysfs_device);
635 		goto err_out;
636 	}
637 
638 	zfcp_port_get(port);
639 
640 	write_lock_irq(&zfcp_data.config_lock);
641 	list_add_tail(&port->list, &adapter->port_list_head);
642 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
643 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
644 
645 	write_unlock_irq(&zfcp_data.config_lock);
646 
647 	zfcp_adapter_get(adapter);
648 	return port;
649 
650 err_out_free:
651 	kfree(port);
652 err_out:
653 	return ERR_PTR(-EINVAL);
654 }
655 
656 /**
657  * zfcp_port_dequeue - dequeues a port from the port list of the adapter
658  * @port: pointer to struct zfcp_port which should be removed
659  */
660 void zfcp_port_dequeue(struct zfcp_port *port)
661 {
662 	wait_event(port->remove_wq, atomic_read(&port->refcount) == 0);
663 	write_lock_irq(&zfcp_data.config_lock);
664 	list_del(&port->list);
665 	write_unlock_irq(&zfcp_data.config_lock);
666 	if (port->rport)
667 		fc_remote_port_delete(port->rport);
668 	port->rport = NULL;
669 	zfcp_adapter_put(port->adapter);
670 	sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
671 	device_unregister(&port->sysfs_device);
672 }
673 
674 /**
675  * zfcp_sg_free_table - free memory used by scatterlists
676  * @sg: pointer to scatterlist
677  * @count: number of scatterlist which are to be free'ed
678  * the scatterlist are expected to reference pages always
679  */
680 void zfcp_sg_free_table(struct scatterlist *sg, int count)
681 {
682 	int i;
683 
684 	for (i = 0; i < count; i++, sg++)
685 		if (sg)
686 			free_page((unsigned long) sg_virt(sg));
687 		else
688 			break;
689 }
690 
691 /**
692  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
693  * @sg: pointer to struct scatterlist
694  * @count: number of scatterlists which should be assigned with buffers
695  * of size page
696  *
697  * Returns: 0 on success, -ENOMEM otherwise
698  */
699 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
700 {
701 	void *addr;
702 	int i;
703 
704 	sg_init_table(sg, count);
705 	for (i = 0; i < count; i++, sg++) {
706 		addr = (void *) get_zeroed_page(GFP_KERNEL);
707 		if (!addr) {
708 			zfcp_sg_free_table(sg, i);
709 			return -ENOMEM;
710 		}
711 		sg_set_buf(sg, addr, PAGE_SIZE);
712 	}
713 	return 0;
714 }
715