xref: /linux/drivers/s390/scsi/zfcp_aux.c (revision 57c237731b92fadc7d44824276313ec330b1989b)
1 /*
2  * zfcp device driver
3  *
4  * Module interface and handling of zfcp data structures.
5  *
6  * Copyright IBM Corporation 2002, 2010
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 <linux/slab.h>
34 #include "zfcp_ext.h"
35 #include "zfcp_fc.h"
36 #include "zfcp_reqlist.h"
37 
38 #define ZFCP_BUS_ID_SIZE	20
39 
40 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
41 MODULE_DESCRIPTION("FCP HBA driver");
42 MODULE_LICENSE("GPL");
43 
44 static char *init_device;
45 module_param_named(device, init_device, charp, 0400);
46 MODULE_PARM_DESC(device, "specify initial device");
47 
48 static struct kmem_cache *zfcp_cache_hw_align(const char *name,
49 					      unsigned long size)
50 {
51 	return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
52 }
53 
54 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
55 {
56 	struct ccw_device *cdev;
57 	struct zfcp_adapter *adapter;
58 	struct zfcp_port *port;
59 	struct zfcp_unit *unit;
60 
61 	cdev = get_ccwdev_by_busid(&zfcp_ccw_driver, busid);
62 	if (!cdev)
63 		return;
64 
65 	if (ccw_device_set_online(cdev))
66 		goto out_ccw_device;
67 
68 	adapter = zfcp_ccw_adapter_by_cdev(cdev);
69 	if (!adapter)
70 		goto out_ccw_device;
71 
72 	port = zfcp_get_port_by_wwpn(adapter, wwpn);
73 	if (!port)
74 		goto out_port;
75 
76 	flush_work(&port->rport_work);
77 	unit = zfcp_unit_enqueue(port, lun);
78 	if (IS_ERR(unit))
79 		goto out_unit;
80 
81 	zfcp_erp_unit_reopen(unit, 0, "auidc_1", NULL);
82 	zfcp_erp_wait(adapter);
83 	zfcp_scsi_scan(unit);
84 
85 out_unit:
86 	put_device(&port->dev);
87 out_port:
88 	zfcp_ccw_adapter_put(adapter);
89 out_ccw_device:
90 	put_device(&cdev->dev);
91 	return;
92 }
93 
94 static void __init zfcp_init_device_setup(char *devstr)
95 {
96 	char *token;
97 	char *str, *str_saved;
98 	char busid[ZFCP_BUS_ID_SIZE];
99 	u64 wwpn, lun;
100 
101 	/* duplicate devstr and keep the original for sysfs presentation*/
102 	str_saved = kstrdup(devstr, GFP_KERNEL);
103 	str = str_saved;
104 	if (!str)
105 		return;
106 
107 	token = strsep(&str, ",");
108 	if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
109 		goto err_out;
110 	strncpy(busid, token, ZFCP_BUS_ID_SIZE);
111 
112 	token = strsep(&str, ",");
113 	if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
114 		goto err_out;
115 
116 	token = strsep(&str, ",");
117 	if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
118 		goto err_out;
119 
120 	kfree(str_saved);
121 	zfcp_init_device_configure(busid, wwpn, lun);
122 	return;
123 
124 err_out:
125 	kfree(str_saved);
126 	pr_err("%s is not a valid SCSI device\n", devstr);
127 }
128 
129 static int __init zfcp_module_init(void)
130 {
131 	int retval = -ENOMEM;
132 
133 	zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
134 					sizeof(struct zfcp_fc_gpn_ft_req));
135 	if (!zfcp_data.gpn_ft_cache)
136 		goto out;
137 
138 	zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
139 					sizeof(struct fsf_qtcb));
140 	if (!zfcp_data.qtcb_cache)
141 		goto out_qtcb_cache;
142 
143 	zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
144 					sizeof(struct fsf_status_read_buffer));
145 	if (!zfcp_data.sr_buffer_cache)
146 		goto out_sr_cache;
147 
148 	zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
149 					sizeof(struct zfcp_fc_gid_pn));
150 	if (!zfcp_data.gid_pn_cache)
151 		goto out_gid_cache;
152 
153 	zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
154 					sizeof(struct zfcp_fc_els_adisc));
155 	if (!zfcp_data.adisc_cache)
156 		goto out_adisc_cache;
157 
158 	zfcp_data.scsi_transport_template =
159 		fc_attach_transport(&zfcp_transport_functions);
160 	if (!zfcp_data.scsi_transport_template)
161 		goto out_transport;
162 	scsi_transport_reserve_device(zfcp_data.scsi_transport_template,
163 				      sizeof(struct zfcp_scsi_dev));
164 
165 
166 	retval = misc_register(&zfcp_cfdc_misc);
167 	if (retval) {
168 		pr_err("Registering the misc device zfcp_cfdc failed\n");
169 		goto out_misc;
170 	}
171 
172 	retval = ccw_driver_register(&zfcp_ccw_driver);
173 	if (retval) {
174 		pr_err("The zfcp device driver could not register with "
175 		       "the common I/O layer\n");
176 		goto out_ccw_register;
177 	}
178 
179 	if (init_device)
180 		zfcp_init_device_setup(init_device);
181 	return 0;
182 
183 out_ccw_register:
184 	misc_deregister(&zfcp_cfdc_misc);
185 out_misc:
186 	fc_release_transport(zfcp_data.scsi_transport_template);
187 out_transport:
188 	kmem_cache_destroy(zfcp_data.adisc_cache);
189 out_adisc_cache:
190 	kmem_cache_destroy(zfcp_data.gid_pn_cache);
191 out_gid_cache:
192 	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
193 out_sr_cache:
194 	kmem_cache_destroy(zfcp_data.qtcb_cache);
195 out_qtcb_cache:
196 	kmem_cache_destroy(zfcp_data.gpn_ft_cache);
197 out:
198 	return retval;
199 }
200 
201 module_init(zfcp_module_init);
202 
203 static void __exit zfcp_module_exit(void)
204 {
205 	ccw_driver_unregister(&zfcp_ccw_driver);
206 	misc_deregister(&zfcp_cfdc_misc);
207 	fc_release_transport(zfcp_data.scsi_transport_template);
208 	kmem_cache_destroy(zfcp_data.adisc_cache);
209 	kmem_cache_destroy(zfcp_data.gid_pn_cache);
210 	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
211 	kmem_cache_destroy(zfcp_data.qtcb_cache);
212 	kmem_cache_destroy(zfcp_data.gpn_ft_cache);
213 }
214 
215 module_exit(zfcp_module_exit);
216 
217 /**
218  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
219  * @port: pointer to port to search for unit
220  * @fcp_lun: FCP LUN to search for
221  *
222  * Returns: pointer to zfcp_unit or NULL
223  */
224 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
225 {
226 	unsigned long flags;
227 	struct zfcp_unit *unit;
228 
229 	read_lock_irqsave(&port->unit_list_lock, flags);
230 	list_for_each_entry(unit, &port->unit_list, list)
231 		if (unit->fcp_lun == fcp_lun) {
232 			if (!get_device(&unit->dev))
233 				unit = NULL;
234 			read_unlock_irqrestore(&port->unit_list_lock, flags);
235 			return unit;
236 		}
237 	read_unlock_irqrestore(&port->unit_list_lock, flags);
238 	return NULL;
239 }
240 
241 /**
242  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
243  * @adapter: pointer to adapter to search for port
244  * @wwpn: wwpn to search for
245  *
246  * Returns: pointer to zfcp_port or NULL
247  */
248 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
249 					u64 wwpn)
250 {
251 	unsigned long flags;
252 	struct zfcp_port *port;
253 
254 	read_lock_irqsave(&adapter->port_list_lock, flags);
255 	list_for_each_entry(port, &adapter->port_list, list)
256 		if (port->wwpn == wwpn) {
257 			if (!get_device(&port->dev))
258 				port = NULL;
259 			read_unlock_irqrestore(&adapter->port_list_lock, flags);
260 			return port;
261 		}
262 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
263 	return NULL;
264 }
265 
266 /**
267  * zfcp_unit_release - dequeue unit
268  * @dev: pointer to device
269  *
270  * waits until all work is done on unit and removes it then from the unit->list
271  * of the associated port.
272  */
273 static void zfcp_unit_release(struct device *dev)
274 {
275 	struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
276 
277 	put_device(&unit->port->dev);
278 	kfree(unit);
279 }
280 
281 /**
282  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
283  * @port: pointer to port where unit is added
284  * @fcp_lun: FCP LUN of unit to be enqueued
285  * Returns: pointer to enqueued unit on success, ERR_PTR on error
286  *
287  * Sets up some unit internal structures and creates sysfs entry.
288  */
289 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
290 {
291 	struct zfcp_unit *unit;
292 	int retval = -ENOMEM;
293 
294 	get_device(&port->dev);
295 
296 	unit = zfcp_get_unit_by_lun(port, fcp_lun);
297 	if (unit) {
298 		put_device(&unit->dev);
299 		retval = -EEXIST;
300 		goto err_out;
301 	}
302 
303 	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
304 	if (!unit)
305 		goto err_out;
306 
307 	unit->port = port;
308 	unit->fcp_lun = fcp_lun;
309 	unit->dev.parent = &port->dev;
310 	unit->dev.release = zfcp_unit_release;
311 
312 	if (dev_set_name(&unit->dev, "0x%016llx",
313 			 (unsigned long long) fcp_lun)) {
314 		kfree(unit);
315 		goto err_out;
316 	}
317 	retval = -EINVAL;
318 
319 	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan_work);
320 
321 	spin_lock_init(&unit->latencies.lock);
322 	unit->latencies.write.channel.min = 0xFFFFFFFF;
323 	unit->latencies.write.fabric.min = 0xFFFFFFFF;
324 	unit->latencies.read.channel.min = 0xFFFFFFFF;
325 	unit->latencies.read.fabric.min = 0xFFFFFFFF;
326 	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
327 	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
328 
329 	if (device_register(&unit->dev)) {
330 		put_device(&unit->dev);
331 		goto err_out;
332 	}
333 
334 	if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs))
335 		goto err_out_put;
336 
337 	write_lock_irq(&port->unit_list_lock);
338 	list_add_tail(&unit->list, &port->unit_list);
339 	write_unlock_irq(&port->unit_list_lock);
340 
341 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
342 
343 	return unit;
344 
345 err_out_put:
346 	device_unregister(&unit->dev);
347 err_out:
348 	put_device(&port->dev);
349 	return ERR_PTR(retval);
350 }
351 
352 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
353 {
354 	adapter->pool.erp_req =
355 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
356 	if (!adapter->pool.erp_req)
357 		return -ENOMEM;
358 
359 	adapter->pool.gid_pn_req =
360 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
361 	if (!adapter->pool.gid_pn_req)
362 		return -ENOMEM;
363 
364 	adapter->pool.scsi_req =
365 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
366 	if (!adapter->pool.scsi_req)
367 		return -ENOMEM;
368 
369 	adapter->pool.scsi_abort =
370 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
371 	if (!adapter->pool.scsi_abort)
372 		return -ENOMEM;
373 
374 	adapter->pool.status_read_req =
375 		mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
376 					    sizeof(struct zfcp_fsf_req));
377 	if (!adapter->pool.status_read_req)
378 		return -ENOMEM;
379 
380 	adapter->pool.qtcb_pool =
381 		mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
382 	if (!adapter->pool.qtcb_pool)
383 		return -ENOMEM;
384 
385 	adapter->pool.status_read_data =
386 		mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
387 					 zfcp_data.sr_buffer_cache);
388 	if (!adapter->pool.status_read_data)
389 		return -ENOMEM;
390 
391 	adapter->pool.gid_pn =
392 		mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
393 	if (!adapter->pool.gid_pn)
394 		return -ENOMEM;
395 
396 	return 0;
397 }
398 
399 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
400 {
401 	if (adapter->pool.erp_req)
402 		mempool_destroy(adapter->pool.erp_req);
403 	if (adapter->pool.scsi_req)
404 		mempool_destroy(adapter->pool.scsi_req);
405 	if (adapter->pool.scsi_abort)
406 		mempool_destroy(adapter->pool.scsi_abort);
407 	if (adapter->pool.qtcb_pool)
408 		mempool_destroy(adapter->pool.qtcb_pool);
409 	if (adapter->pool.status_read_req)
410 		mempool_destroy(adapter->pool.status_read_req);
411 	if (adapter->pool.status_read_data)
412 		mempool_destroy(adapter->pool.status_read_data);
413 	if (adapter->pool.gid_pn)
414 		mempool_destroy(adapter->pool.gid_pn);
415 }
416 
417 /**
418  * zfcp_status_read_refill - refill the long running status_read_requests
419  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
420  *
421  * Returns: 0 on success, 1 otherwise
422  *
423  * if there are 16 or more status_read requests missing an adapter_reopen
424  * is triggered
425  */
426 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
427 {
428 	while (atomic_read(&adapter->stat_miss) > 0)
429 		if (zfcp_fsf_status_read(adapter->qdio)) {
430 			if (atomic_read(&adapter->stat_miss) >=
431 			    adapter->stat_read_buf_num) {
432 				zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
433 							NULL);
434 				return 1;
435 			}
436 			break;
437 		} else
438 			atomic_dec(&adapter->stat_miss);
439 	return 0;
440 }
441 
442 static void _zfcp_status_read_scheduler(struct work_struct *work)
443 {
444 	zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
445 					     stat_work));
446 }
447 
448 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
449 {
450 	struct zfcp_adapter *adapter =
451 		container_of(sl, struct zfcp_adapter, service_level);
452 
453 	seq_printf(m, "zfcp: %s microcode level %x\n",
454 		   dev_name(&adapter->ccw_device->dev),
455 		   adapter->fsf_lic_version);
456 }
457 
458 static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
459 {
460 	char name[TASK_COMM_LEN];
461 
462 	snprintf(name, sizeof(name), "zfcp_q_%s",
463 		 dev_name(&adapter->ccw_device->dev));
464 	adapter->work_queue = create_singlethread_workqueue(name);
465 
466 	if (adapter->work_queue)
467 		return 0;
468 	return -ENOMEM;
469 }
470 
471 static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
472 {
473 	if (adapter->work_queue)
474 		destroy_workqueue(adapter->work_queue);
475 	adapter->work_queue = NULL;
476 
477 }
478 
479 /**
480  * zfcp_adapter_enqueue - enqueue a new adapter to the list
481  * @ccw_device: pointer to the struct cc_device
482  *
483  * Returns:	struct zfcp_adapter*
484  * Enqueues an adapter at the end of the adapter list in the driver data.
485  * All adapter internal structures are set up.
486  * Proc-fs entries are also created.
487  */
488 struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
489 {
490 	struct zfcp_adapter *adapter;
491 
492 	if (!get_device(&ccw_device->dev))
493 		return ERR_PTR(-ENODEV);
494 
495 	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
496 	if (!adapter) {
497 		put_device(&ccw_device->dev);
498 		return ERR_PTR(-ENOMEM);
499 	}
500 
501 	kref_init(&adapter->ref);
502 
503 	ccw_device->handler = NULL;
504 	adapter->ccw_device = ccw_device;
505 
506 	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
507 	INIT_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
508 
509 	if (zfcp_qdio_setup(adapter))
510 		goto failed;
511 
512 	if (zfcp_allocate_low_mem_buffers(adapter))
513 		goto failed;
514 
515 	adapter->req_list = zfcp_reqlist_alloc();
516 	if (!adapter->req_list)
517 		goto failed;
518 
519 	if (zfcp_dbf_adapter_register(adapter))
520 		goto failed;
521 
522 	if (zfcp_setup_adapter_work_queue(adapter))
523 		goto failed;
524 
525 	if (zfcp_fc_gs_setup(adapter))
526 		goto failed;
527 
528 	rwlock_init(&adapter->port_list_lock);
529 	INIT_LIST_HEAD(&adapter->port_list);
530 
531 	INIT_LIST_HEAD(&adapter->events.list);
532 	INIT_WORK(&adapter->events.work, zfcp_fc_post_event);
533 	spin_lock_init(&adapter->events.list_lock);
534 
535 	init_waitqueue_head(&adapter->erp_ready_wq);
536 	init_waitqueue_head(&adapter->erp_done_wqh);
537 
538 	INIT_LIST_HEAD(&adapter->erp_ready_head);
539 	INIT_LIST_HEAD(&adapter->erp_running_head);
540 
541 	rwlock_init(&adapter->erp_lock);
542 	rwlock_init(&adapter->abort_lock);
543 
544 	if (zfcp_erp_thread_setup(adapter))
545 		goto failed;
546 
547 	adapter->service_level.seq_print = zfcp_print_sl;
548 
549 	dev_set_drvdata(&ccw_device->dev, adapter);
550 
551 	if (sysfs_create_group(&ccw_device->dev.kobj,
552 			       &zfcp_sysfs_adapter_attrs))
553 		goto failed;
554 
555 	/* report size limit per scatter-gather segment */
556 	adapter->dma_parms.max_segment_size = ZFCP_QDIO_SBALE_LEN;
557 	adapter->ccw_device->dev.dma_parms = &adapter->dma_parms;
558 
559 	if (!zfcp_adapter_scsi_register(adapter))
560 		return adapter;
561 
562 failed:
563 	zfcp_adapter_unregister(adapter);
564 	return ERR_PTR(-ENOMEM);
565 }
566 
567 void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
568 {
569 	struct ccw_device *cdev = adapter->ccw_device;
570 
571 	cancel_work_sync(&adapter->scan_work);
572 	cancel_work_sync(&adapter->stat_work);
573 	zfcp_destroy_adapter_work_queue(adapter);
574 
575 	zfcp_fc_wka_ports_force_offline(adapter->gs);
576 	zfcp_adapter_scsi_unregister(adapter);
577 	sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
578 
579 	zfcp_erp_thread_kill(adapter);
580 	zfcp_dbf_adapter_unregister(adapter->dbf);
581 	zfcp_qdio_destroy(adapter->qdio);
582 
583 	zfcp_ccw_adapter_put(adapter); /* final put to release */
584 }
585 
586 /**
587  * zfcp_adapter_release - remove the adapter from the resource list
588  * @ref: pointer to struct kref
589  * locks:	adapter list write lock is assumed to be held by caller
590  */
591 void zfcp_adapter_release(struct kref *ref)
592 {
593 	struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
594 						    ref);
595 	struct ccw_device *cdev = adapter->ccw_device;
596 
597 	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
598 	zfcp_fc_gs_destroy(adapter);
599 	zfcp_free_low_mem_buffers(adapter);
600 	kfree(adapter->req_list);
601 	kfree(adapter->fc_stats);
602 	kfree(adapter->stats_reset_data);
603 	kfree(adapter);
604 	put_device(&cdev->dev);
605 }
606 
607 /**
608  * zfcp_device_unregister - remove port, unit from system
609  * @dev: reference to device which is to be removed
610  * @grp: related reference to attribute group
611  *
612  * Helper function to unregister port, unit from system
613  */
614 void zfcp_device_unregister(struct device *dev,
615 			    const struct attribute_group *grp)
616 {
617 	sysfs_remove_group(&dev->kobj, grp);
618 	device_unregister(dev);
619 }
620 
621 static void zfcp_port_release(struct device *dev)
622 {
623 	struct zfcp_port *port = container_of(dev, struct zfcp_port, dev);
624 
625 	zfcp_ccw_adapter_put(port->adapter);
626 	kfree(port);
627 }
628 
629 /**
630  * zfcp_port_enqueue - enqueue port to port list of adapter
631  * @adapter: adapter where remote port is added
632  * @wwpn: WWPN of the remote port to be enqueued
633  * @status: initial status for the port
634  * @d_id: destination id of the remote port to be enqueued
635  * Returns: pointer to enqueued port on success, ERR_PTR on error
636  *
637  * All port internal structures are set up and the sysfs entry is generated.
638  * d_id is used to enqueue ports with a well known address like the Directory
639  * Service for nameserver lookup.
640  */
641 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
642 				     u32 status, u32 d_id)
643 {
644 	struct zfcp_port *port;
645 	int retval = -ENOMEM;
646 
647 	kref_get(&adapter->ref);
648 
649 	port = zfcp_get_port_by_wwpn(adapter, wwpn);
650 	if (port) {
651 		put_device(&port->dev);
652 		retval = -EEXIST;
653 		goto err_out;
654 	}
655 
656 	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
657 	if (!port)
658 		goto err_out;
659 
660 	rwlock_init(&port->unit_list_lock);
661 	INIT_LIST_HEAD(&port->unit_list);
662 
663 	INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
664 	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
665 	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
666 
667 	port->adapter = adapter;
668 	port->d_id = d_id;
669 	port->wwpn = wwpn;
670 	port->rport_task = RPORT_NONE;
671 	port->dev.parent = &adapter->ccw_device->dev;
672 	port->dev.release = zfcp_port_release;
673 
674 	if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
675 		kfree(port);
676 		goto err_out;
677 	}
678 	retval = -EINVAL;
679 
680 	if (device_register(&port->dev)) {
681 		put_device(&port->dev);
682 		goto err_out;
683 	}
684 
685 	if (sysfs_create_group(&port->dev.kobj,
686 			       &zfcp_sysfs_port_attrs))
687 		goto err_out_put;
688 
689 	write_lock_irq(&adapter->port_list_lock);
690 	list_add_tail(&port->list, &adapter->port_list);
691 	write_unlock_irq(&adapter->port_list_lock);
692 
693 	atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
694 
695 	return port;
696 
697 err_out_put:
698 	device_unregister(&port->dev);
699 err_out:
700 	zfcp_ccw_adapter_put(adapter);
701 	return ERR_PTR(retval);
702 }
703 
704 /**
705  * zfcp_sg_free_table - free memory used by scatterlists
706  * @sg: pointer to scatterlist
707  * @count: number of scatterlist which are to be free'ed
708  * the scatterlist are expected to reference pages always
709  */
710 void zfcp_sg_free_table(struct scatterlist *sg, int count)
711 {
712 	int i;
713 
714 	for (i = 0; i < count; i++, sg++)
715 		if (sg)
716 			free_page((unsigned long) sg_virt(sg));
717 		else
718 			break;
719 }
720 
721 /**
722  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
723  * @sg: pointer to struct scatterlist
724  * @count: number of scatterlists which should be assigned with buffers
725  * of size page
726  *
727  * Returns: 0 on success, -ENOMEM otherwise
728  */
729 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
730 {
731 	void *addr;
732 	int i;
733 
734 	sg_init_table(sg, count);
735 	for (i = 0; i < count; i++, sg++) {
736 		addr = (void *) get_zeroed_page(GFP_KERNEL);
737 		if (!addr) {
738 			zfcp_sg_free_table(sg, i);
739 			return -ENOMEM;
740 		}
741 		sg_set_buf(sg, addr, PAGE_SIZE);
742 	}
743 	return 0;
744 }
745