xref: /openbmc/linux/drivers/s390/scsi/zfcp_aux.c (revision 7dd65feb)
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 #include "zfcp_fc.h"
35 
36 #define ZFCP_BUS_ID_SIZE	20
37 
38 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
39 MODULE_DESCRIPTION("FCP HBA driver");
40 MODULE_LICENSE("GPL");
41 
42 static char *init_device;
43 module_param_named(device, init_device, charp, 0400);
44 MODULE_PARM_DESC(device, "specify initial device");
45 
46 static struct kmem_cache *zfcp_cache_hw_align(const char *name,
47 					      unsigned long size)
48 {
49 	return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
50 }
51 
52 static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
53 {
54 	int idx;
55 
56 	adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
57 				    GFP_KERNEL);
58 	if (!adapter->req_list)
59 		return -ENOMEM;
60 
61 	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
62 		INIT_LIST_HEAD(&adapter->req_list[idx]);
63 	return 0;
64 }
65 
66 /**
67  * zfcp_reqlist_isempty - is the request list empty
68  * @adapter: pointer to struct zfcp_adapter
69  *
70  * Returns: true if list is empty, false otherwise
71  */
72 int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
73 {
74 	unsigned int idx;
75 
76 	for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
77 		if (!list_empty(&adapter->req_list[idx]))
78 			return 0;
79 	return 1;
80 }
81 
82 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
83 {
84 	struct ccw_device *cdev;
85 	struct zfcp_adapter *adapter;
86 	struct zfcp_port *port;
87 	struct zfcp_unit *unit;
88 
89 	cdev = get_ccwdev_by_busid(&zfcp_ccw_driver, busid);
90 	if (!cdev)
91 		return;
92 
93 	if (ccw_device_set_online(cdev))
94 		goto out_ccw_device;
95 
96 	adapter = zfcp_ccw_adapter_by_cdev(cdev);
97 	if (!adapter)
98 		goto out_ccw_device;
99 
100 	port = zfcp_get_port_by_wwpn(adapter, wwpn);
101 	if (!port)
102 		goto out_port;
103 
104 	unit = zfcp_unit_enqueue(port, lun);
105 	if (IS_ERR(unit))
106 		goto out_unit;
107 
108 	zfcp_erp_unit_reopen(unit, 0, "auidc_1", NULL);
109 	zfcp_erp_wait(adapter);
110 	flush_work(&unit->scsi_work);
111 
112 out_unit:
113 	put_device(&port->sysfs_device);
114 out_port:
115 	zfcp_ccw_adapter_put(adapter);
116 out_ccw_device:
117 	put_device(&cdev->dev);
118 	return;
119 }
120 
121 static void __init zfcp_init_device_setup(char *devstr)
122 {
123 	char *token;
124 	char *str, *str_saved;
125 	char busid[ZFCP_BUS_ID_SIZE];
126 	u64 wwpn, lun;
127 
128 	/* duplicate devstr and keep the original for sysfs presentation*/
129 	str_saved = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
130 	str = str_saved;
131 	if (!str)
132 		return;
133 
134 	strcpy(str, devstr);
135 
136 	token = strsep(&str, ",");
137 	if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
138 		goto err_out;
139 	strncpy(busid, token, ZFCP_BUS_ID_SIZE);
140 
141 	token = strsep(&str, ",");
142 	if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
143 		goto err_out;
144 
145 	token = strsep(&str, ",");
146 	if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
147 		goto err_out;
148 
149 	kfree(str_saved);
150 	zfcp_init_device_configure(busid, wwpn, lun);
151 	return;
152 
153 err_out:
154 	kfree(str_saved);
155 	pr_err("%s is not a valid SCSI device\n", devstr);
156 }
157 
158 static int __init zfcp_module_init(void)
159 {
160 	int retval = -ENOMEM;
161 
162 	zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
163 					sizeof(struct zfcp_fc_gpn_ft_req));
164 	if (!zfcp_data.gpn_ft_cache)
165 		goto out;
166 
167 	zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
168 					sizeof(struct fsf_qtcb));
169 	if (!zfcp_data.qtcb_cache)
170 		goto out_qtcb_cache;
171 
172 	zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
173 					sizeof(struct fsf_status_read_buffer));
174 	if (!zfcp_data.sr_buffer_cache)
175 		goto out_sr_cache;
176 
177 	zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
178 					sizeof(struct zfcp_fc_gid_pn));
179 	if (!zfcp_data.gid_pn_cache)
180 		goto out_gid_cache;
181 
182 	zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
183 					sizeof(struct zfcp_fc_els_adisc));
184 	if (!zfcp_data.adisc_cache)
185 		goto out_adisc_cache;
186 
187 	zfcp_data.scsi_transport_template =
188 		fc_attach_transport(&zfcp_transport_functions);
189 	if (!zfcp_data.scsi_transport_template)
190 		goto out_transport;
191 
192 	retval = misc_register(&zfcp_cfdc_misc);
193 	if (retval) {
194 		pr_err("Registering the misc device zfcp_cfdc failed\n");
195 		goto out_misc;
196 	}
197 
198 	retval = ccw_driver_register(&zfcp_ccw_driver);
199 	if (retval) {
200 		pr_err("The zfcp device driver could not register with "
201 		       "the common I/O layer\n");
202 		goto out_ccw_register;
203 	}
204 
205 	if (init_device)
206 		zfcp_init_device_setup(init_device);
207 	return 0;
208 
209 out_ccw_register:
210 	misc_deregister(&zfcp_cfdc_misc);
211 out_misc:
212 	fc_release_transport(zfcp_data.scsi_transport_template);
213 out_transport:
214 	kmem_cache_destroy(zfcp_data.adisc_cache);
215 out_adisc_cache:
216 	kmem_cache_destroy(zfcp_data.gid_pn_cache);
217 out_gid_cache:
218 	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
219 out_sr_cache:
220 	kmem_cache_destroy(zfcp_data.qtcb_cache);
221 out_qtcb_cache:
222 	kmem_cache_destroy(zfcp_data.gpn_ft_cache);
223 out:
224 	return retval;
225 }
226 
227 module_init(zfcp_module_init);
228 
229 static void __exit zfcp_module_exit(void)
230 {
231 	ccw_driver_unregister(&zfcp_ccw_driver);
232 	misc_deregister(&zfcp_cfdc_misc);
233 	fc_release_transport(zfcp_data.scsi_transport_template);
234 	kmem_cache_destroy(zfcp_data.adisc_cache);
235 	kmem_cache_destroy(zfcp_data.gid_pn_cache);
236 	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
237 	kmem_cache_destroy(zfcp_data.qtcb_cache);
238 	kmem_cache_destroy(zfcp_data.gpn_ft_cache);
239 }
240 
241 module_exit(zfcp_module_exit);
242 
243 /**
244  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
245  * @port: pointer to port to search for unit
246  * @fcp_lun: FCP LUN to search for
247  *
248  * Returns: pointer to zfcp_unit or NULL
249  */
250 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
251 {
252 	unsigned long flags;
253 	struct zfcp_unit *unit;
254 
255 	read_lock_irqsave(&port->unit_list_lock, flags);
256 	list_for_each_entry(unit, &port->unit_list, list)
257 		if (unit->fcp_lun == fcp_lun) {
258 			if (!get_device(&unit->sysfs_device))
259 				unit = NULL;
260 			read_unlock_irqrestore(&port->unit_list_lock, flags);
261 			return unit;
262 		}
263 	read_unlock_irqrestore(&port->unit_list_lock, flags);
264 	return NULL;
265 }
266 
267 /**
268  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
269  * @adapter: pointer to adapter to search for port
270  * @wwpn: wwpn to search for
271  *
272  * Returns: pointer to zfcp_port or NULL
273  */
274 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
275 					u64 wwpn)
276 {
277 	unsigned long flags;
278 	struct zfcp_port *port;
279 
280 	read_lock_irqsave(&adapter->port_list_lock, flags);
281 	list_for_each_entry(port, &adapter->port_list, list)
282 		if (port->wwpn == wwpn) {
283 			if (!get_device(&port->sysfs_device))
284 				port = NULL;
285 			read_unlock_irqrestore(&adapter->port_list_lock, flags);
286 			return port;
287 		}
288 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
289 	return NULL;
290 }
291 
292 /**
293  * zfcp_unit_release - dequeue unit
294  * @dev: pointer to device
295  *
296  * waits until all work is done on unit and removes it then from the unit->list
297  * of the associated port.
298  */
299 static void zfcp_unit_release(struct device *dev)
300 {
301 	struct zfcp_unit *unit = container_of(dev, struct zfcp_unit,
302 					      sysfs_device);
303 
304 	put_device(&unit->port->sysfs_device);
305 	kfree(unit);
306 }
307 
308 /**
309  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
310  * @port: pointer to port where unit is added
311  * @fcp_lun: FCP LUN of unit to be enqueued
312  * Returns: pointer to enqueued unit on success, ERR_PTR on error
313  *
314  * Sets up some unit internal structures and creates sysfs entry.
315  */
316 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
317 {
318 	struct zfcp_unit *unit;
319 	int retval = -ENOMEM;
320 
321 	get_device(&port->sysfs_device);
322 
323 	unit = zfcp_get_unit_by_lun(port, fcp_lun);
324 	if (unit) {
325 		put_device(&unit->sysfs_device);
326 		retval = -EEXIST;
327 		goto err_out;
328 	}
329 
330 	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
331 	if (!unit)
332 		goto err_out;
333 
334 	unit->port = port;
335 	unit->fcp_lun = fcp_lun;
336 	unit->sysfs_device.parent = &port->sysfs_device;
337 	unit->sysfs_device.release = zfcp_unit_release;
338 
339 	if (dev_set_name(&unit->sysfs_device, "0x%016llx",
340 			 (unsigned long long) fcp_lun)) {
341 		kfree(unit);
342 		goto err_out;
343 	}
344 	retval = -EINVAL;
345 
346 	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
347 
348 	spin_lock_init(&unit->latencies.lock);
349 	unit->latencies.write.channel.min = 0xFFFFFFFF;
350 	unit->latencies.write.fabric.min = 0xFFFFFFFF;
351 	unit->latencies.read.channel.min = 0xFFFFFFFF;
352 	unit->latencies.read.fabric.min = 0xFFFFFFFF;
353 	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
354 	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
355 
356 	if (device_register(&unit->sysfs_device)) {
357 		put_device(&unit->sysfs_device);
358 		goto err_out;
359 	}
360 
361 	if (sysfs_create_group(&unit->sysfs_device.kobj,
362 			       &zfcp_sysfs_unit_attrs))
363 		goto err_out_put;
364 
365 	write_lock_irq(&port->unit_list_lock);
366 	list_add_tail(&unit->list, &port->unit_list);
367 	write_unlock_irq(&port->unit_list_lock);
368 
369 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
370 
371 	return unit;
372 
373 err_out_put:
374 	device_unregister(&unit->sysfs_device);
375 err_out:
376 	put_device(&port->sysfs_device);
377 	return ERR_PTR(retval);
378 }
379 
380 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
381 {
382 	adapter->pool.erp_req =
383 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
384 	if (!adapter->pool.erp_req)
385 		return -ENOMEM;
386 
387 	adapter->pool.gid_pn_req =
388 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
389 	if (!adapter->pool.gid_pn_req)
390 		return -ENOMEM;
391 
392 	adapter->pool.scsi_req =
393 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
394 	if (!adapter->pool.scsi_req)
395 		return -ENOMEM;
396 
397 	adapter->pool.scsi_abort =
398 		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
399 	if (!adapter->pool.scsi_abort)
400 		return -ENOMEM;
401 
402 	adapter->pool.status_read_req =
403 		mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
404 					    sizeof(struct zfcp_fsf_req));
405 	if (!adapter->pool.status_read_req)
406 		return -ENOMEM;
407 
408 	adapter->pool.qtcb_pool =
409 		mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
410 	if (!adapter->pool.qtcb_pool)
411 		return -ENOMEM;
412 
413 	adapter->pool.status_read_data =
414 		mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
415 					 zfcp_data.sr_buffer_cache);
416 	if (!adapter->pool.status_read_data)
417 		return -ENOMEM;
418 
419 	adapter->pool.gid_pn =
420 		mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
421 	if (!adapter->pool.gid_pn)
422 		return -ENOMEM;
423 
424 	return 0;
425 }
426 
427 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
428 {
429 	if (adapter->pool.erp_req)
430 		mempool_destroy(adapter->pool.erp_req);
431 	if (adapter->pool.scsi_req)
432 		mempool_destroy(adapter->pool.scsi_req);
433 	if (adapter->pool.scsi_abort)
434 		mempool_destroy(adapter->pool.scsi_abort);
435 	if (adapter->pool.qtcb_pool)
436 		mempool_destroy(adapter->pool.qtcb_pool);
437 	if (adapter->pool.status_read_req)
438 		mempool_destroy(adapter->pool.status_read_req);
439 	if (adapter->pool.status_read_data)
440 		mempool_destroy(adapter->pool.status_read_data);
441 	if (adapter->pool.gid_pn)
442 		mempool_destroy(adapter->pool.gid_pn);
443 }
444 
445 /**
446  * zfcp_status_read_refill - refill the long running status_read_requests
447  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
448  *
449  * Returns: 0 on success, 1 otherwise
450  *
451  * if there are 16 or more status_read requests missing an adapter_reopen
452  * is triggered
453  */
454 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
455 {
456 	while (atomic_read(&adapter->stat_miss) > 0)
457 		if (zfcp_fsf_status_read(adapter->qdio)) {
458 			if (atomic_read(&adapter->stat_miss) >= 16) {
459 				zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
460 							NULL);
461 				return 1;
462 			}
463 			break;
464 		} else
465 			atomic_dec(&adapter->stat_miss);
466 	return 0;
467 }
468 
469 static void _zfcp_status_read_scheduler(struct work_struct *work)
470 {
471 	zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
472 					     stat_work));
473 }
474 
475 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
476 {
477 	struct zfcp_adapter *adapter =
478 		container_of(sl, struct zfcp_adapter, service_level);
479 
480 	seq_printf(m, "zfcp: %s microcode level %x\n",
481 		   dev_name(&adapter->ccw_device->dev),
482 		   adapter->fsf_lic_version);
483 }
484 
485 static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
486 {
487 	char name[TASK_COMM_LEN];
488 
489 	snprintf(name, sizeof(name), "zfcp_q_%s",
490 		 dev_name(&adapter->ccw_device->dev));
491 	adapter->work_queue = create_singlethread_workqueue(name);
492 
493 	if (adapter->work_queue)
494 		return 0;
495 	return -ENOMEM;
496 }
497 
498 static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
499 {
500 	if (adapter->work_queue)
501 		destroy_workqueue(adapter->work_queue);
502 	adapter->work_queue = NULL;
503 
504 }
505 
506 /**
507  * zfcp_adapter_enqueue - enqueue a new adapter to the list
508  * @ccw_device: pointer to the struct cc_device
509  *
510  * Returns:	struct zfcp_adapter*
511  * Enqueues an adapter at the end of the adapter list in the driver data.
512  * All adapter internal structures are set up.
513  * Proc-fs entries are also created.
514  */
515 struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
516 {
517 	struct zfcp_adapter *adapter;
518 
519 	if (!get_device(&ccw_device->dev))
520 		return ERR_PTR(-ENODEV);
521 
522 	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
523 	if (!adapter) {
524 		put_device(&ccw_device->dev);
525 		return ERR_PTR(-ENOMEM);
526 	}
527 
528 	kref_init(&adapter->ref);
529 
530 	ccw_device->handler = NULL;
531 	adapter->ccw_device = ccw_device;
532 
533 	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
534 	INIT_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
535 
536 	if (zfcp_qdio_setup(adapter))
537 		goto failed;
538 
539 	if (zfcp_allocate_low_mem_buffers(adapter))
540 		goto failed;
541 
542 	if (zfcp_reqlist_alloc(adapter))
543 		goto failed;
544 
545 	if (zfcp_dbf_adapter_register(adapter))
546 		goto failed;
547 
548 	if (zfcp_setup_adapter_work_queue(adapter))
549 		goto failed;
550 
551 	if (zfcp_fc_gs_setup(adapter))
552 		goto failed;
553 
554 	rwlock_init(&adapter->port_list_lock);
555 	INIT_LIST_HEAD(&adapter->port_list);
556 
557 	init_waitqueue_head(&adapter->erp_ready_wq);
558 	init_waitqueue_head(&adapter->erp_done_wqh);
559 
560 	INIT_LIST_HEAD(&adapter->erp_ready_head);
561 	INIT_LIST_HEAD(&adapter->erp_running_head);
562 
563 	spin_lock_init(&adapter->req_list_lock);
564 
565 	rwlock_init(&adapter->erp_lock);
566 	rwlock_init(&adapter->abort_lock);
567 
568 	if (zfcp_erp_thread_setup(adapter))
569 		goto failed;
570 
571 	adapter->service_level.seq_print = zfcp_print_sl;
572 
573 	dev_set_drvdata(&ccw_device->dev, adapter);
574 
575 	if (sysfs_create_group(&ccw_device->dev.kobj,
576 			       &zfcp_sysfs_adapter_attrs))
577 		goto failed;
578 
579 	if (!zfcp_adapter_scsi_register(adapter))
580 		return adapter;
581 
582 failed:
583 	zfcp_adapter_unregister(adapter);
584 	return ERR_PTR(-ENOMEM);
585 }
586 
587 void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
588 {
589 	struct ccw_device *cdev = adapter->ccw_device;
590 
591 	cancel_work_sync(&adapter->scan_work);
592 	cancel_work_sync(&adapter->stat_work);
593 	zfcp_destroy_adapter_work_queue(adapter);
594 
595 	zfcp_fc_wka_ports_force_offline(adapter->gs);
596 	zfcp_adapter_scsi_unregister(adapter);
597 	sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
598 
599 	zfcp_erp_thread_kill(adapter);
600 	zfcp_dbf_adapter_unregister(adapter->dbf);
601 	zfcp_qdio_destroy(adapter->qdio);
602 
603 	zfcp_ccw_adapter_put(adapter); /* final put to release */
604 }
605 
606 /**
607  * zfcp_adapter_release - remove the adapter from the resource list
608  * @ref: pointer to struct kref
609  * locks:	adapter list write lock is assumed to be held by caller
610  */
611 void zfcp_adapter_release(struct kref *ref)
612 {
613 	struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
614 						    ref);
615 	struct ccw_device *cdev = adapter->ccw_device;
616 
617 	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
618 	zfcp_fc_gs_destroy(adapter);
619 	zfcp_free_low_mem_buffers(adapter);
620 	kfree(adapter->req_list);
621 	kfree(adapter->fc_stats);
622 	kfree(adapter->stats_reset_data);
623 	kfree(adapter);
624 	put_device(&cdev->dev);
625 }
626 
627 /**
628  * zfcp_device_unregister - remove port, unit from system
629  * @dev: reference to device which is to be removed
630  * @grp: related reference to attribute group
631  *
632  * Helper function to unregister port, unit from system
633  */
634 void zfcp_device_unregister(struct device *dev,
635 			    const struct attribute_group *grp)
636 {
637 	sysfs_remove_group(&dev->kobj, grp);
638 	device_unregister(dev);
639 }
640 
641 static void zfcp_port_release(struct device *dev)
642 {
643 	struct zfcp_port *port = container_of(dev, struct zfcp_port,
644 					      sysfs_device);
645 
646 	zfcp_ccw_adapter_put(port->adapter);
647 	kfree(port);
648 }
649 
650 /**
651  * zfcp_port_enqueue - enqueue port to port list of adapter
652  * @adapter: adapter where remote port is added
653  * @wwpn: WWPN of the remote port to be enqueued
654  * @status: initial status for the port
655  * @d_id: destination id of the remote port to be enqueued
656  * Returns: pointer to enqueued port on success, ERR_PTR on error
657  *
658  * All port internal structures are set up and the sysfs entry is generated.
659  * d_id is used to enqueue ports with a well known address like the Directory
660  * Service for nameserver lookup.
661  */
662 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
663 				     u32 status, u32 d_id)
664 {
665 	struct zfcp_port *port;
666 	int retval = -ENOMEM;
667 
668 	kref_get(&adapter->ref);
669 
670 	port = zfcp_get_port_by_wwpn(adapter, wwpn);
671 	if (port) {
672 		put_device(&port->sysfs_device);
673 		retval = -EEXIST;
674 		goto err_out;
675 	}
676 
677 	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
678 	if (!port)
679 		goto err_out;
680 
681 	rwlock_init(&port->unit_list_lock);
682 	INIT_LIST_HEAD(&port->unit_list);
683 
684 	INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
685 	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
686 	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
687 
688 	port->adapter = adapter;
689 	port->d_id = d_id;
690 	port->wwpn = wwpn;
691 	port->rport_task = RPORT_NONE;
692 	port->sysfs_device.parent = &adapter->ccw_device->dev;
693 	port->sysfs_device.release = zfcp_port_release;
694 
695 	if (dev_set_name(&port->sysfs_device, "0x%016llx",
696 			 (unsigned long long)wwpn)) {
697 		kfree(port);
698 		goto err_out;
699 	}
700 	retval = -EINVAL;
701 
702 	if (device_register(&port->sysfs_device)) {
703 		put_device(&port->sysfs_device);
704 		goto err_out;
705 	}
706 
707 	if (sysfs_create_group(&port->sysfs_device.kobj,
708 			       &zfcp_sysfs_port_attrs))
709 		goto err_out_put;
710 
711 	write_lock_irq(&adapter->port_list_lock);
712 	list_add_tail(&port->list, &adapter->port_list);
713 	write_unlock_irq(&adapter->port_list_lock);
714 
715 	atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
716 
717 	return port;
718 
719 err_out_put:
720 	device_unregister(&port->sysfs_device);
721 err_out:
722 	zfcp_ccw_adapter_put(adapter);
723 	return ERR_PTR(retval);
724 }
725 
726 /**
727  * zfcp_sg_free_table - free memory used by scatterlists
728  * @sg: pointer to scatterlist
729  * @count: number of scatterlist which are to be free'ed
730  * the scatterlist are expected to reference pages always
731  */
732 void zfcp_sg_free_table(struct scatterlist *sg, int count)
733 {
734 	int i;
735 
736 	for (i = 0; i < count; i++, sg++)
737 		if (sg)
738 			free_page((unsigned long) sg_virt(sg));
739 		else
740 			break;
741 }
742 
743 /**
744  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
745  * @sg: pointer to struct scatterlist
746  * @count: number of scatterlists which should be assigned with buffers
747  * of size page
748  *
749  * Returns: 0 on success, -ENOMEM otherwise
750  */
751 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
752 {
753 	void *addr;
754 	int i;
755 
756 	sg_init_table(sg, count);
757 	for (i = 0; i < count; i++, sg++) {
758 		addr = (void *) get_zeroed_page(GFP_KERNEL);
759 		if (!addr) {
760 			zfcp_sg_free_table(sg, i);
761 			return -ENOMEM;
762 		}
763 		sg_set_buf(sg, addr, PAGE_SIZE);
764 	}
765 	return 0;
766 }
767