xref: /openbmc/linux/drivers/s390/scsi/zfcp_aux.c (revision 5f5bac82)
1 /*
2  * zfcp device driver
3  *
4  * Module interface and handling of zfcp data structures.
5  *
6  * Copyright IBM Corporation 2002, 2009
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 #define KMSG_COMPONENT "zfcp"
29 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
30 
31 #include <linux/miscdevice.h>
32 #include <linux/seq_file.h>
33 #include "zfcp_ext.h"
34 
35 #define ZFCP_BUS_ID_SIZE	20
36 
37 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
38 MODULE_DESCRIPTION("FCP HBA driver");
39 MODULE_LICENSE("GPL");
40 
41 static char *init_device;
42 module_param_named(device, init_device, charp, 0400);
43 MODULE_PARM_DESC(device, "specify initial device");
44 
45 static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
46 {
47 	int idx;
48 
49 	adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
50 				    GFP_KERNEL);
51 	if (!adapter->req_list)
52 		return -ENOMEM;
53 
54 	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
55 		INIT_LIST_HEAD(&adapter->req_list[idx]);
56 	return 0;
57 }
58 
59 /**
60  * zfcp_reqlist_isempty - is the request list empty
61  * @adapter: pointer to struct zfcp_adapter
62  *
63  * Returns: true if list is empty, false otherwise
64  */
65 int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
66 {
67 	unsigned int idx;
68 
69 	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
70 		if (!list_empty(&adapter->req_list[idx]))
71 			return 0;
72 	return 1;
73 }
74 
75 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
76 {
77 	struct zfcp_adapter *adapter;
78 	struct zfcp_port *port;
79 	struct zfcp_unit *unit;
80 
81 	down(&zfcp_data.config_sema);
82 	read_lock_irq(&zfcp_data.config_lock);
83 	adapter = zfcp_get_adapter_by_busid(busid);
84 	if (adapter)
85 		zfcp_adapter_get(adapter);
86 	read_unlock_irq(&zfcp_data.config_lock);
87 
88 	if (!adapter)
89 		goto out_adapter;
90 	port = zfcp_port_enqueue(adapter, wwpn, 0, 0);
91 	if (IS_ERR(port))
92 		goto out_port;
93 	unit = zfcp_unit_enqueue(port, lun);
94 	if (IS_ERR(unit))
95 		goto out_unit;
96 	up(&zfcp_data.config_sema);
97 	ccw_device_set_online(adapter->ccw_device);
98 
99 	zfcp_erp_wait(adapter);
100 	flush_work(&unit->scsi_work);
101 
102 	down(&zfcp_data.config_sema);
103 	zfcp_unit_put(unit);
104 out_unit:
105 	zfcp_port_put(port);
106 out_port:
107 	zfcp_adapter_put(adapter);
108 out_adapter:
109 	up(&zfcp_data.config_sema);
110 	return;
111 }
112 
113 static struct kmem_cache *zfcp_cache_create(int size, char *name)
114 {
115 	int align = 1;
116 	while ((size - align) > 0)
117 		align <<= 1;
118 	return kmem_cache_create(name , size, align, 0, NULL);
119 }
120 
121 static void __init zfcp_init_device_setup(char *devstr)
122 {
123 	char *token;
124 	char *str;
125 	char busid[ZFCP_BUS_ID_SIZE];
126 	u64 wwpn, lun;
127 
128 	/* duplicate devstr and keep the original for sysfs presentation*/
129 	str = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
130 	if (!str)
131 		return;
132 
133 	strcpy(str, devstr);
134 
135 	token = strsep(&str, ",");
136 	if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
137 		goto err_out;
138 	strncpy(busid, token, ZFCP_BUS_ID_SIZE);
139 
140 	token = strsep(&str, ",");
141 	if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
142 		goto err_out;
143 
144 	token = strsep(&str, ",");
145 	if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
146 		goto err_out;
147 
148 	kfree(str);
149 	zfcp_init_device_configure(busid, wwpn, lun);
150 	return;
151 
152  err_out:
153 	kfree(str);
154 	pr_err("%s is not a valid SCSI device\n", devstr);
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 	sema_init(&zfcp_data.config_sema, 1);
179 	rwlock_init(&zfcp_data.config_lock);
180 
181 	zfcp_data.scsi_transport_template =
182 		fc_attach_transport(&zfcp_transport_functions);
183 	if (!zfcp_data.scsi_transport_template)
184 		goto out_transport;
185 
186 	retval = misc_register(&zfcp_cfdc_misc);
187 	if (retval) {
188 		pr_err("Registering the misc device zfcp_cfdc failed\n");
189 		goto out_misc;
190 	}
191 
192 	retval = zfcp_ccw_register();
193 	if (retval) {
194 		pr_err("The zfcp device driver could not register with "
195 		       "the common I/O layer\n");
196 		goto out_ccw_register;
197 	}
198 
199 	if (init_device)
200 		zfcp_init_device_setup(init_device);
201 	return 0;
202 
203 out_ccw_register:
204 	misc_deregister(&zfcp_cfdc_misc);
205 out_misc:
206 	fc_release_transport(zfcp_data.scsi_transport_template);
207 out_transport:
208 	kmem_cache_destroy(zfcp_data.gid_pn_cache);
209 out_gid_cache:
210 	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
211 out_sr_cache:
212 	kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
213 out:
214 	return retval;
215 }
216 
217 module_init(zfcp_module_init);
218 
219 /**
220  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
221  * @port: pointer to port to search for unit
222  * @fcp_lun: FCP LUN to search for
223  *
224  * Returns: pointer to zfcp_unit or NULL
225  */
226 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
227 {
228 	struct zfcp_unit *unit;
229 
230 	list_for_each_entry(unit, &port->unit_list_head, list)
231 		if ((unit->fcp_lun == fcp_lun) &&
232 		    !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE))
233 		    return unit;
234 	return NULL;
235 }
236 
237 /**
238  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
239  * @adapter: pointer to adapter to search for port
240  * @wwpn: wwpn to search for
241  *
242  * Returns: pointer to zfcp_port or NULL
243  */
244 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
245 					u64 wwpn)
246 {
247 	struct zfcp_port *port;
248 
249 	list_for_each_entry(port, &adapter->port_list_head, list)
250 		if ((port->wwpn == wwpn) &&
251 		    !(atomic_read(&port->status) & ZFCP_STATUS_COMMON_REMOVE))
252 			return port;
253 	return NULL;
254 }
255 
256 static void zfcp_sysfs_unit_release(struct device *dev)
257 {
258 	kfree(container_of(dev, struct zfcp_unit, sysfs_device));
259 }
260 
261 /**
262  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
263  * @port: pointer to port where unit is added
264  * @fcp_lun: FCP LUN of unit to be enqueued
265  * Returns: pointer to enqueued unit on success, ERR_PTR on error
266  * Locks: config_sema must be held to serialize changes to the unit list
267  *
268  * Sets up some unit internal structures and creates sysfs entry.
269  */
270 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
271 {
272 	struct zfcp_unit *unit;
273 
274 	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
275 	if (!unit)
276 		return ERR_PTR(-ENOMEM);
277 
278 	atomic_set(&unit->refcount, 0);
279 	init_waitqueue_head(&unit->remove_wq);
280 	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
281 
282 	unit->port = port;
283 	unit->fcp_lun = fcp_lun;
284 
285 	dev_set_name(&unit->sysfs_device, "0x%016llx",
286 		     (unsigned long long) fcp_lun);
287 	unit->sysfs_device.parent = &port->sysfs_device;
288 	unit->sysfs_device.release = zfcp_sysfs_unit_release;
289 	dev_set_drvdata(&unit->sysfs_device, unit);
290 
291 	/* mark unit unusable as long as sysfs registration is not complete */
292 	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
293 
294 	spin_lock_init(&unit->latencies.lock);
295 	unit->latencies.write.channel.min = 0xFFFFFFFF;
296 	unit->latencies.write.fabric.min = 0xFFFFFFFF;
297 	unit->latencies.read.channel.min = 0xFFFFFFFF;
298 	unit->latencies.read.fabric.min = 0xFFFFFFFF;
299 	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
300 	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
301 
302 	read_lock_irq(&zfcp_data.config_lock);
303 	if (zfcp_get_unit_by_lun(port, fcp_lun)) {
304 		read_unlock_irq(&zfcp_data.config_lock);
305 		goto err_out_free;
306 	}
307 	read_unlock_irq(&zfcp_data.config_lock);
308 
309 	if (device_register(&unit->sysfs_device))
310 		goto err_out_free;
311 
312 	if (sysfs_create_group(&unit->sysfs_device.kobj,
313 			       &zfcp_sysfs_unit_attrs)) {
314 		device_unregister(&unit->sysfs_device);
315 		return ERR_PTR(-EIO);
316 	}
317 
318 	zfcp_unit_get(unit);
319 
320 	write_lock_irq(&zfcp_data.config_lock);
321 	list_add_tail(&unit->list, &port->unit_list_head);
322 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
323 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
324 
325 	write_unlock_irq(&zfcp_data.config_lock);
326 
327 	zfcp_port_get(port);
328 
329 	return unit;
330 
331 err_out_free:
332 	kfree(unit);
333 	return ERR_PTR(-EINVAL);
334 }
335 
336 /**
337  * zfcp_unit_dequeue - dequeue unit
338  * @unit: pointer to zfcp_unit
339  *
340  * waits until all work is done on unit and removes it then from the unit->list
341  * of the associated port.
342  */
343 void zfcp_unit_dequeue(struct zfcp_unit *unit)
344 {
345 	wait_event(unit->remove_wq, atomic_read(&unit->refcount) == 0);
346 	write_lock_irq(&zfcp_data.config_lock);
347 	list_del(&unit->list);
348 	write_unlock_irq(&zfcp_data.config_lock);
349 	zfcp_port_put(unit->port);
350 	sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
351 	device_unregister(&unit->sysfs_device);
352 }
353 
354 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
355 {
356 	/* must only be called with zfcp_data.config_sema taken */
357 	adapter->pool.fsf_req_erp =
358 		mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
359 	if (!adapter->pool.fsf_req_erp)
360 		return -ENOMEM;
361 
362 	adapter->pool.fsf_req_scsi =
363 		mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
364 	if (!adapter->pool.fsf_req_scsi)
365 		return -ENOMEM;
366 
367 	adapter->pool.fsf_req_abort =
368 		mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
369 	if (!adapter->pool.fsf_req_abort)
370 		return -ENOMEM;
371 
372 	adapter->pool.fsf_req_status_read =
373 		mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
374 					    sizeof(struct zfcp_fsf_req));
375 	if (!adapter->pool.fsf_req_status_read)
376 		return -ENOMEM;
377 
378 	adapter->pool.data_status_read =
379 		mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
380 					 zfcp_data.sr_buffer_cache);
381 	if (!adapter->pool.data_status_read)
382 		return -ENOMEM;
383 
384 	adapter->pool.data_gid_pn =
385 		mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
386 	if (!adapter->pool.data_gid_pn)
387 		return -ENOMEM;
388 
389 	return 0;
390 }
391 
392 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
393 {
394 	/* zfcp_data.config_sema must be held */
395 	if (adapter->pool.fsf_req_erp)
396 		mempool_destroy(adapter->pool.fsf_req_erp);
397 	if (adapter->pool.fsf_req_scsi)
398 		mempool_destroy(adapter->pool.fsf_req_scsi);
399 	if (adapter->pool.fsf_req_abort)
400 		mempool_destroy(adapter->pool.fsf_req_abort);
401 	if (adapter->pool.fsf_req_status_read)
402 		mempool_destroy(adapter->pool.fsf_req_status_read);
403 	if (adapter->pool.data_status_read)
404 		mempool_destroy(adapter->pool.data_status_read);
405 	if (adapter->pool.data_gid_pn)
406 		mempool_destroy(adapter->pool.data_gid_pn);
407 }
408 
409 /**
410  * zfcp_status_read_refill - refill the long running status_read_requests
411  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
412  *
413  * Returns: 0 on success, 1 otherwise
414  *
415  * if there are 16 or more status_read requests missing an adapter_reopen
416  * is triggered
417  */
418 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
419 {
420 	while (atomic_read(&adapter->stat_miss) > 0)
421 		if (zfcp_fsf_status_read(adapter)) {
422 			if (atomic_read(&adapter->stat_miss) >= 16) {
423 				zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
424 							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 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
440 {
441 	struct zfcp_adapter *adapter =
442 		container_of(sl, struct zfcp_adapter, service_level);
443 
444 	seq_printf(m, "zfcp: %s microcode level %x\n",
445 		   dev_name(&adapter->ccw_device->dev),
446 		   adapter->fsf_lic_version);
447 }
448 
449 /**
450  * zfcp_adapter_enqueue - enqueue a new adapter to the list
451  * @ccw_device: pointer to the struct cc_device
452  *
453  * Returns:	0             if a new adapter was successfully enqueued
454  *		-ENOMEM       if alloc failed
455  * Enqueues an adapter at the end of the adapter list in the driver data.
456  * All adapter internal structures are set up.
457  * Proc-fs entries are also created.
458  * locks:	config_sema must be held to serialise changes to the adapter list
459  */
460 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
461 {
462 	struct zfcp_adapter *adapter;
463 
464 	/*
465 	 * Note: It is safe to release the list_lock, as any list changes
466 	 * are protected by the config_sema, which must be held to get here
467 	 */
468 
469 	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
470 	if (!adapter)
471 		return -ENOMEM;
472 
473 	ccw_device->handler = NULL;
474 	adapter->ccw_device = ccw_device;
475 	atomic_set(&adapter->refcount, 0);
476 
477 	if (zfcp_qdio_allocate(adapter))
478 		goto qdio_allocate_failed;
479 
480 	if (zfcp_allocate_low_mem_buffers(adapter))
481 		goto failed_low_mem_buffers;
482 
483 	if (zfcp_reqlist_alloc(adapter))
484 		goto failed_low_mem_buffers;
485 
486 	if (zfcp_adapter_debug_register(adapter))
487 		goto debug_register_failed;
488 
489 	init_waitqueue_head(&adapter->remove_wq);
490 	init_waitqueue_head(&adapter->erp_thread_wqh);
491 	init_waitqueue_head(&adapter->erp_done_wqh);
492 
493 	INIT_LIST_HEAD(&adapter->port_list_head);
494 	INIT_LIST_HEAD(&adapter->erp_ready_head);
495 	INIT_LIST_HEAD(&adapter->erp_running_head);
496 
497 	spin_lock_init(&adapter->req_list_lock);
498 
499 	spin_lock_init(&adapter->hba_dbf_lock);
500 	spin_lock_init(&adapter->san_dbf_lock);
501 	spin_lock_init(&adapter->scsi_dbf_lock);
502 	spin_lock_init(&adapter->rec_dbf_lock);
503 	spin_lock_init(&adapter->req_q_lock);
504 	spin_lock_init(&adapter->qdio_stat_lock);
505 
506 	rwlock_init(&adapter->erp_lock);
507 	rwlock_init(&adapter->abort_lock);
508 
509 	sema_init(&adapter->erp_ready_sem, 0);
510 
511 	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
512 	INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);
513 
514 	adapter->service_level.seq_print = zfcp_print_sl;
515 
516 	/* mark adapter unusable as long as sysfs registration is not complete */
517 	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
518 
519 	dev_set_drvdata(&ccw_device->dev, adapter);
520 
521 	if (sysfs_create_group(&ccw_device->dev.kobj,
522 			       &zfcp_sysfs_adapter_attrs))
523 		goto sysfs_failed;
524 
525 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
526 
527 	zfcp_fc_nameserver_init(adapter);
528 
529 	if (!zfcp_adapter_scsi_register(adapter))
530 		return 0;
531 
532 sysfs_failed:
533 	zfcp_adapter_debug_unregister(adapter);
534 debug_register_failed:
535 	dev_set_drvdata(&ccw_device->dev, NULL);
536 	kfree(adapter->req_list);
537 failed_low_mem_buffers:
538 	zfcp_free_low_mem_buffers(adapter);
539 qdio_allocate_failed:
540 	zfcp_qdio_free(adapter);
541 	kfree(adapter);
542 	return -ENOMEM;
543 }
544 
545 /**
546  * zfcp_adapter_dequeue - remove the adapter from the resource list
547  * @adapter: pointer to struct zfcp_adapter which should be removed
548  * locks:	adapter list write lock is assumed to be held by caller
549  */
550 void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
551 {
552 	int retval = 0;
553 	unsigned long flags;
554 
555 	cancel_work_sync(&adapter->scan_work);
556 	cancel_work_sync(&adapter->stat_work);
557 	zfcp_adapter_scsi_unregister(adapter);
558 	sysfs_remove_group(&adapter->ccw_device->dev.kobj,
559 			   &zfcp_sysfs_adapter_attrs);
560 	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
561 	/* sanity check: no pending FSF requests */
562 	spin_lock_irqsave(&adapter->req_list_lock, flags);
563 	retval = zfcp_reqlist_isempty(adapter);
564 	spin_unlock_irqrestore(&adapter->req_list_lock, flags);
565 	if (!retval)
566 		return;
567 
568 	zfcp_adapter_debug_unregister(adapter);
569 	zfcp_qdio_free(adapter);
570 	zfcp_free_low_mem_buffers(adapter);
571 	kfree(adapter->req_list);
572 	kfree(adapter->fc_stats);
573 	kfree(adapter->stats_reset_data);
574 	kfree(adapter);
575 }
576 
577 static void zfcp_sysfs_port_release(struct device *dev)
578 {
579 	kfree(container_of(dev, struct zfcp_port, sysfs_device));
580 }
581 
582 /**
583  * zfcp_port_enqueue - enqueue port to port list of adapter
584  * @adapter: adapter where remote port is added
585  * @wwpn: WWPN of the remote port to be enqueued
586  * @status: initial status for the port
587  * @d_id: destination id of the remote port to be enqueued
588  * Returns: pointer to enqueued port on success, ERR_PTR on error
589  * Locks: config_sema must be held to serialize changes to the port list
590  *
591  * All port internal structures are set up and the sysfs entry is generated.
592  * d_id is used to enqueue ports with a well known address like the Directory
593  * Service for nameserver lookup.
594  */
595 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
596 				     u32 status, u32 d_id)
597 {
598 	struct zfcp_port *port;
599 	int retval;
600 
601 	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
602 	if (!port)
603 		return ERR_PTR(-ENOMEM);
604 
605 	init_waitqueue_head(&port->remove_wq);
606 	INIT_LIST_HEAD(&port->unit_list_head);
607 	INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);
608 	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
609 	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
610 
611 	port->adapter = adapter;
612 	port->d_id = d_id;
613 	port->wwpn = wwpn;
614 	port->rport_task = RPORT_NONE;
615 
616 	/* mark port unusable as long as sysfs registration is not complete */
617 	atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
618 	atomic_set(&port->refcount, 0);
619 
620 	dev_set_name(&port->sysfs_device, "0x%016llx",
621 		     (unsigned long long)wwpn);
622 	port->sysfs_device.parent = &adapter->ccw_device->dev;
623 
624 	port->sysfs_device.release = zfcp_sysfs_port_release;
625 	dev_set_drvdata(&port->sysfs_device, port);
626 
627 	read_lock_irq(&zfcp_data.config_lock);
628 	if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
629 		read_unlock_irq(&zfcp_data.config_lock);
630 		goto err_out_free;
631 	}
632 	read_unlock_irq(&zfcp_data.config_lock);
633 
634 	if (device_register(&port->sysfs_device))
635 		goto err_out_free;
636 
637 	retval = sysfs_create_group(&port->sysfs_device.kobj,
638 				    &zfcp_sysfs_port_attrs);
639 
640 	if (retval) {
641 		device_unregister(&port->sysfs_device);
642 		goto err_out;
643 	}
644 
645 	zfcp_port_get(port);
646 
647 	write_lock_irq(&zfcp_data.config_lock);
648 	list_add_tail(&port->list, &adapter->port_list_head);
649 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
650 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
651 
652 	write_unlock_irq(&zfcp_data.config_lock);
653 
654 	zfcp_adapter_get(adapter);
655 	return port;
656 
657 err_out_free:
658 	kfree(port);
659 err_out:
660 	return ERR_PTR(-EINVAL);
661 }
662 
663 /**
664  * zfcp_port_dequeue - dequeues a port from the port list of the adapter
665  * @port: pointer to struct zfcp_port which should be removed
666  */
667 void zfcp_port_dequeue(struct zfcp_port *port)
668 {
669 	wait_event(port->remove_wq, atomic_read(&port->refcount) == 0);
670 	write_lock_irq(&zfcp_data.config_lock);
671 	list_del(&port->list);
672 	write_unlock_irq(&zfcp_data.config_lock);
673 	if (port->rport)
674 		port->rport->dd_data = NULL;
675 	zfcp_adapter_put(port->adapter);
676 	sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
677 	device_unregister(&port->sysfs_device);
678 }
679 
680 /**
681  * zfcp_sg_free_table - free memory used by scatterlists
682  * @sg: pointer to scatterlist
683  * @count: number of scatterlist which are to be free'ed
684  * the scatterlist are expected to reference pages always
685  */
686 void zfcp_sg_free_table(struct scatterlist *sg, int count)
687 {
688 	int i;
689 
690 	for (i = 0; i < count; i++, sg++)
691 		if (sg)
692 			free_page((unsigned long) sg_virt(sg));
693 		else
694 			break;
695 }
696 
697 /**
698  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
699  * @sg: pointer to struct scatterlist
700  * @count: number of scatterlists which should be assigned with buffers
701  * of size page
702  *
703  * Returns: 0 on success, -ENOMEM otherwise
704  */
705 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
706 {
707 	void *addr;
708 	int i;
709 
710 	sg_init_table(sg, count);
711 	for (i = 0; i < count; i++, sg++) {
712 		addr = (void *) get_zeroed_page(GFP_KERNEL);
713 		if (!addr) {
714 			zfcp_sg_free_table(sg, i);
715 			return -ENOMEM;
716 		}
717 		sg_set_buf(sg, addr, PAGE_SIZE);
718 	}
719 	return 0;
720 }
721