[SCSI] zfcp: Simplify get_adapter_by_busid
[linux-2.6.git] / drivers / s390 / scsi / zfcp_aux.c
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         zfcp_erp_wait(adapter);
133         down(&zfcp_data.config_sema);
134         zfcp_unit_put(unit);
135 out_unit:
136         zfcp_port_put(port);
137 out_port:
138         zfcp_adapter_put(adapter);
139 out_adapter:
140         up(&zfcp_data.config_sema);
141         return;
142 }
143
144 static struct kmem_cache *zfcp_cache_create(int size, char *name)
145 {
146         int align = 1;
147         while ((size - align) > 0)
148                 align <<= 1;
149         return kmem_cache_create(name , size, align, 0, NULL);
150 }
151
152 static int __init zfcp_module_init(void)
153 {
154         int retval = -ENOMEM;
155
156         zfcp_data.fsf_req_qtcb_cache = zfcp_cache_create(
157                         sizeof(struct zfcp_fsf_req_qtcb), "zfcp_fsf");
158         if (!zfcp_data.fsf_req_qtcb_cache)
159                 goto out;
160
161         zfcp_data.sr_buffer_cache = zfcp_cache_create(
162                         sizeof(struct fsf_status_read_buffer), "zfcp_sr");
163         if (!zfcp_data.sr_buffer_cache)
164                 goto out_sr_cache;
165
166         zfcp_data.gid_pn_cache = zfcp_cache_create(
167                         sizeof(struct zfcp_gid_pn_data), "zfcp_gid");
168         if (!zfcp_data.gid_pn_cache)
169                 goto out_gid_cache;
170
171         INIT_LIST_HEAD(&zfcp_data.adapter_list_head);
172         INIT_LIST_HEAD(&zfcp_data.adapter_remove_lh);
173
174         sema_init(&zfcp_data.config_sema, 1);
175         rwlock_init(&zfcp_data.config_lock);
176
177         zfcp_data.scsi_transport_template =
178                 fc_attach_transport(&zfcp_transport_functions);
179         if (!zfcp_data.scsi_transport_template)
180                 goto out_transport;
181
182         retval = misc_register(&zfcp_cfdc_misc);
183         if (retval) {
184                 pr_err("zfcp: Registering the misc device zfcp_cfdc failed\n");
185                 goto out_misc;
186         }
187
188         retval = zfcp_ccw_register();
189         if (retval) {
190                 pr_err("zfcp: The zfcp device driver could not register with "
191                        "the common I/O layer\n");
192                 goto out_ccw_register;
193         }
194
195         if (zfcp_device_setup(device))
196                 zfcp_init_device_configure();
197
198         goto out;
199
200 out_ccw_register:
201         misc_deregister(&zfcp_cfdc_misc);
202 out_misc:
203         fc_release_transport(zfcp_data.scsi_transport_template);
204 out_transport:
205         kmem_cache_destroy(zfcp_data.gid_pn_cache);
206 out_gid_cache:
207         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
208 out_sr_cache:
209         kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
210 out:
211         return retval;
212 }
213
214 module_init(zfcp_module_init);
215
216 /**
217  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
218  * @port: pointer to port to search for unit
219  * @fcp_lun: FCP LUN to search for
220  *
221  * Returns: pointer to zfcp_unit or NULL
222  */
223 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
224 {
225         struct zfcp_unit *unit;
226
227         list_for_each_entry(unit, &port->unit_list_head, list)
228                 if ((unit->fcp_lun == fcp_lun) &&
229                     !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE))
230                     return unit;
231         return NULL;
232 }
233
234 /**
235  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
236  * @adapter: pointer to adapter to search for port
237  * @wwpn: wwpn to search for
238  *
239  * Returns: pointer to zfcp_port or NULL
240  */
241 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
242                                         u64 wwpn)
243 {
244         struct zfcp_port *port;
245
246         list_for_each_entry(port, &adapter->port_list_head, list)
247                 if ((port->wwpn == wwpn) && !(atomic_read(&port->status) &
248                       (ZFCP_STATUS_PORT_NO_WWPN | ZFCP_STATUS_COMMON_REMOVE)))
249                         return port;
250         return NULL;
251 }
252
253 static void zfcp_sysfs_unit_release(struct device *dev)
254 {
255         kfree(container_of(dev, struct zfcp_unit, sysfs_device));
256 }
257
258 /**
259  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
260  * @port: pointer to port where unit is added
261  * @fcp_lun: FCP LUN of unit to be enqueued
262  * Returns: pointer to enqueued unit on success, ERR_PTR on error
263  * Locks: config_sema must be held to serialize changes to the unit list
264  *
265  * Sets up some unit internal structures and creates sysfs entry.
266  */
267 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
268 {
269         struct zfcp_unit *unit;
270
271         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
272         if (!unit)
273                 return ERR_PTR(-ENOMEM);
274
275         atomic_set(&unit->refcount, 0);
276         init_waitqueue_head(&unit->remove_wq);
277
278         unit->port = port;
279         unit->fcp_lun = fcp_lun;
280
281         snprintf(unit->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx",
282                  (unsigned long long) fcp_lun);
283         unit->sysfs_device.parent = &port->sysfs_device;
284         unit->sysfs_device.release = zfcp_sysfs_unit_release;
285         dev_set_drvdata(&unit->sysfs_device, unit);
286
287         /* mark unit unusable as long as sysfs registration is not complete */
288         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
289
290         spin_lock_init(&unit->latencies.lock);
291         unit->latencies.write.channel.min = 0xFFFFFFFF;
292         unit->latencies.write.fabric.min = 0xFFFFFFFF;
293         unit->latencies.read.channel.min = 0xFFFFFFFF;
294         unit->latencies.read.fabric.min = 0xFFFFFFFF;
295         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
296         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
297
298         read_lock_irq(&zfcp_data.config_lock);
299         if (zfcp_get_unit_by_lun(port, fcp_lun)) {
300                 read_unlock_irq(&zfcp_data.config_lock);
301                 goto err_out_free;
302         }
303         read_unlock_irq(&zfcp_data.config_lock);
304
305         if (device_register(&unit->sysfs_device))
306                 goto err_out_free;
307
308         if (sysfs_create_group(&unit->sysfs_device.kobj,
309                                &zfcp_sysfs_unit_attrs)) {
310                 device_unregister(&unit->sysfs_device);
311                 return ERR_PTR(-EIO);
312         }
313
314         zfcp_unit_get(unit);
315         unit->scsi_lun = scsilun_to_int((struct scsi_lun *)&unit->fcp_lun);
316
317         write_lock_irq(&zfcp_data.config_lock);
318         list_add_tail(&unit->list, &port->unit_list_head);
319         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
320         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
321
322         write_unlock_irq(&zfcp_data.config_lock);
323
324         port->units++;
325         zfcp_port_get(port);
326
327         return unit;
328
329 err_out_free:
330         kfree(unit);
331         return ERR_PTR(-EINVAL);
332 }
333
334 /**
335  * zfcp_unit_dequeue - dequeue unit
336  * @unit: pointer to zfcp_unit
337  *
338  * waits until all work is done on unit and removes it then from the unit->list
339  * of the associated port.
340  */
341 void zfcp_unit_dequeue(struct zfcp_unit *unit)
342 {
343         wait_event(unit->remove_wq, atomic_read(&unit->refcount) == 0);
344         write_lock_irq(&zfcp_data.config_lock);
345         list_del(&unit->list);
346         write_unlock_irq(&zfcp_data.config_lock);
347         unit->port->units--;
348         zfcp_port_put(unit->port);
349         sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
350         device_unregister(&unit->sysfs_device);
351 }
352
353 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
354 {
355         /* must only be called with zfcp_data.config_sema taken */
356         adapter->pool.fsf_req_erp =
357                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
358         if (!adapter->pool.fsf_req_erp)
359                 return -ENOMEM;
360
361         adapter->pool.fsf_req_scsi =
362                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
363         if (!adapter->pool.fsf_req_scsi)
364                 return -ENOMEM;
365
366         adapter->pool.fsf_req_abort =
367                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
368         if (!adapter->pool.fsf_req_abort)
369                 return -ENOMEM;
370
371         adapter->pool.fsf_req_status_read =
372                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
373                                             sizeof(struct zfcp_fsf_req));
374         if (!adapter->pool.fsf_req_status_read)
375                 return -ENOMEM;
376
377         adapter->pool.data_status_read =
378                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
379                                          zfcp_data.sr_buffer_cache);
380         if (!adapter->pool.data_status_read)
381                 return -ENOMEM;
382
383         adapter->pool.data_gid_pn =
384                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
385         if (!adapter->pool.data_gid_pn)
386                 return -ENOMEM;
387
388         return 0;
389 }
390
391 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
392 {
393         /* zfcp_data.config_sema must be held */
394         if (adapter->pool.fsf_req_erp)
395                 mempool_destroy(adapter->pool.fsf_req_erp);
396         if (adapter->pool.fsf_req_scsi)
397                 mempool_destroy(adapter->pool.fsf_req_scsi);
398         if (adapter->pool.fsf_req_abort)
399                 mempool_destroy(adapter->pool.fsf_req_abort);
400         if (adapter->pool.fsf_req_status_read)
401                 mempool_destroy(adapter->pool.fsf_req_status_read);
402         if (adapter->pool.data_status_read)
403                 mempool_destroy(adapter->pool.data_status_read);
404         if (adapter->pool.data_gid_pn)
405                 mempool_destroy(adapter->pool.data_gid_pn);
406 }
407
408 static void zfcp_dummy_release(struct device *dev)
409 {
410         return;
411 }
412
413 /**
414  * zfcp_status_read_refill - refill the long running status_read_requests
415  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
416  *
417  * Returns: 0 on success, 1 otherwise
418  *
419  * if there are 16 or more status_read requests missing an adapter_reopen
420  * is triggered
421  */
422 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
423 {
424         while (atomic_read(&adapter->stat_miss) > 0)
425                 if (zfcp_fsf_status_read(adapter)) {
426                         if (atomic_read(&adapter->stat_miss) >= 16) {
427                                 zfcp_erp_adapter_reopen(adapter, 0, 103, NULL);
428                                 return 1;
429                         }
430                         break;
431                 } else
432                         atomic_dec(&adapter->stat_miss);
433         return 0;
434 }
435
436 static void _zfcp_status_read_scheduler(struct work_struct *work)
437 {
438         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
439                                              stat_work));
440 }
441
442 /**
443  * zfcp_adapter_enqueue - enqueue a new adapter to the list
444  * @ccw_device: pointer to the struct cc_device
445  *
446  * Returns:     0             if a new adapter was successfully enqueued
447  *              -ENOMEM       if alloc failed
448  * Enqueues an adapter at the end of the adapter list in the driver data.
449  * All adapter internal structures are set up.
450  * Proc-fs entries are also created.
451  * locks:       config_sema must be held to serialise changes to the adapter list
452  */
453 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
454 {
455         struct zfcp_adapter *adapter;
456
457         /*
458          * Note: It is safe to release the list_lock, as any list changes
459          * are protected by the config_sema, which must be held to get here
460          */
461
462         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
463         if (!adapter)
464                 return -ENOMEM;
465
466         ccw_device->handler = NULL;
467         adapter->ccw_device = ccw_device;
468         atomic_set(&adapter->refcount, 0);
469
470         if (zfcp_qdio_allocate(adapter))
471                 goto qdio_allocate_failed;
472
473         if (zfcp_allocate_low_mem_buffers(adapter))
474                 goto failed_low_mem_buffers;
475
476         if (zfcp_reqlist_alloc(adapter))
477                 goto failed_low_mem_buffers;
478
479         if (zfcp_adapter_debug_register(adapter))
480                 goto debug_register_failed;
481
482         init_waitqueue_head(&adapter->remove_wq);
483         init_waitqueue_head(&adapter->erp_thread_wqh);
484         init_waitqueue_head(&adapter->erp_done_wqh);
485
486         INIT_LIST_HEAD(&adapter->port_list_head);
487         INIT_LIST_HEAD(&adapter->port_remove_lh);
488         INIT_LIST_HEAD(&adapter->erp_ready_head);
489         INIT_LIST_HEAD(&adapter->erp_running_head);
490
491         spin_lock_init(&adapter->req_list_lock);
492
493         spin_lock_init(&adapter->hba_dbf_lock);
494         spin_lock_init(&adapter->san_dbf_lock);
495         spin_lock_init(&adapter->scsi_dbf_lock);
496         spin_lock_init(&adapter->rec_dbf_lock);
497         spin_lock_init(&adapter->req_q.lock);
498
499         rwlock_init(&adapter->erp_lock);
500         rwlock_init(&adapter->abort_lock);
501
502         sema_init(&adapter->erp_ready_sem, 0);
503
504         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
505         INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);
506
507         /* mark adapter unusable as long as sysfs registration is not complete */
508         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
509
510         dev_set_drvdata(&ccw_device->dev, adapter);
511
512         if (sysfs_create_group(&ccw_device->dev.kobj,
513                                &zfcp_sysfs_adapter_attrs))
514                 goto sysfs_failed;
515
516         adapter->generic_services.parent = &adapter->ccw_device->dev;
517         adapter->generic_services.release = zfcp_dummy_release;
518         snprintf(adapter->generic_services.bus_id, BUS_ID_SIZE,
519                  "generic_services");
520
521         if (device_register(&adapter->generic_services))
522                 goto generic_services_failed;
523
524         write_lock_irq(&zfcp_data.config_lock);
525         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
526         list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
527         write_unlock_irq(&zfcp_data.config_lock);
528
529         zfcp_data.adapters++;
530
531         zfcp_fc_nameserver_init(adapter);
532
533         return 0;
534
535 generic_services_failed:
536         sysfs_remove_group(&ccw_device->dev.kobj,
537                            &zfcp_sysfs_adapter_attrs);
538 sysfs_failed:
539         zfcp_adapter_debug_unregister(adapter);
540 debug_register_failed:
541         dev_set_drvdata(&ccw_device->dev, NULL);
542         kfree(adapter->req_list);
543 failed_low_mem_buffers:
544         zfcp_free_low_mem_buffers(adapter);
545 qdio_allocate_failed:
546         zfcp_qdio_free(adapter);
547         kfree(adapter);
548         return -ENOMEM;
549 }
550
551 /**
552  * zfcp_adapter_dequeue - remove the adapter from the resource list
553  * @adapter: pointer to struct zfcp_adapter which should be removed
554  * locks:       adapter list write lock is assumed to be held by caller
555  */
556 void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
557 {
558         int retval = 0;
559         unsigned long flags;
560
561         cancel_work_sync(&adapter->scan_work);
562         cancel_work_sync(&adapter->stat_work);
563         zfcp_adapter_scsi_unregister(adapter);
564         device_unregister(&adapter->generic_services);
565         sysfs_remove_group(&adapter->ccw_device->dev.kobj,
566                            &zfcp_sysfs_adapter_attrs);
567         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
568         /* sanity check: no pending FSF requests */
569         spin_lock_irqsave(&adapter->req_list_lock, flags);
570         retval = zfcp_reqlist_isempty(adapter);
571         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
572         if (!retval)
573                 return;
574
575         zfcp_adapter_debug_unregister(adapter);
576
577         /* remove specified adapter data structure from list */
578         write_lock_irq(&zfcp_data.config_lock);
579         list_del(&adapter->list);
580         write_unlock_irq(&zfcp_data.config_lock);
581
582         /* decrease number of adapters in list */
583         zfcp_data.adapters--;
584
585         zfcp_qdio_free(adapter);
586
587         zfcp_free_low_mem_buffers(adapter);
588         kfree(adapter->req_list);
589         kfree(adapter->fc_stats);
590         kfree(adapter->stats_reset_data);
591         kfree(adapter);
592 }
593
594 static void zfcp_sysfs_port_release(struct device *dev)
595 {
596         kfree(container_of(dev, struct zfcp_port, sysfs_device));
597 }
598
599 /**
600  * zfcp_port_enqueue - enqueue port to port list of adapter
601  * @adapter: adapter where remote port is added
602  * @wwpn: WWPN of the remote port to be enqueued
603  * @status: initial status for the port
604  * @d_id: destination id of the remote port to be enqueued
605  * Returns: pointer to enqueued port on success, ERR_PTR on error
606  * Locks: config_sema must be held to serialize changes to the port list
607  *
608  * All port internal structures are set up and the sysfs entry is generated.
609  * d_id is used to enqueue ports with a well known address like the Directory
610  * Service for nameserver lookup.
611  */
612 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
613                                      u32 status, u32 d_id)
614 {
615         struct zfcp_port *port;
616         int retval;
617
618         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
619         if (!port)
620                 return ERR_PTR(-ENOMEM);
621
622         init_waitqueue_head(&port->remove_wq);
623
624         INIT_LIST_HEAD(&port->unit_list_head);
625         INIT_LIST_HEAD(&port->unit_remove_lh);
626         INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);
627
628         port->adapter = adapter;
629         port->d_id = d_id;
630         port->wwpn = wwpn;
631
632         /* mark port unusable as long as sysfs registration is not complete */
633         atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
634         atomic_set(&port->refcount, 0);
635
636         snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx",
637                  (unsigned long long) wwpn);
638         port->sysfs_device.parent = &adapter->ccw_device->dev;
639
640         port->sysfs_device.release = zfcp_sysfs_port_release;
641         dev_set_drvdata(&port->sysfs_device, port);
642
643         read_lock_irq(&zfcp_data.config_lock);
644         if (!(status & ZFCP_STATUS_PORT_NO_WWPN))
645                 if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
646                         read_unlock_irq(&zfcp_data.config_lock);
647                         goto err_out_free;
648                 }
649         read_unlock_irq(&zfcp_data.config_lock);
650
651         if (device_register(&port->sysfs_device))
652                 goto err_out_free;
653
654         retval = sysfs_create_group(&port->sysfs_device.kobj,
655                                     &zfcp_sysfs_port_attrs);
656
657         if (retval) {
658                 device_unregister(&port->sysfs_device);
659                 goto err_out;
660         }
661
662         zfcp_port_get(port);
663
664         write_lock_irq(&zfcp_data.config_lock);
665         list_add_tail(&port->list, &adapter->port_list_head);
666         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
667         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
668         adapter->ports++;
669
670         write_unlock_irq(&zfcp_data.config_lock);
671
672         zfcp_adapter_get(adapter);
673         return port;
674
675 err_out_free:
676         kfree(port);
677 err_out:
678         return ERR_PTR(-EINVAL);
679 }
680
681 /**
682  * zfcp_port_dequeue - dequeues a port from the port list of the adapter
683  * @port: pointer to struct zfcp_port which should be removed
684  */
685 void zfcp_port_dequeue(struct zfcp_port *port)
686 {
687         wait_event(port->remove_wq, atomic_read(&port->refcount) == 0);
688         write_lock_irq(&zfcp_data.config_lock);
689         list_del(&port->list);
690         port->adapter->ports--;
691         write_unlock_irq(&zfcp_data.config_lock);
692         if (port->rport)
693                 fc_remote_port_delete(port->rport);
694         port->rport = NULL;
695         zfcp_adapter_put(port->adapter);
696         sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
697         device_unregister(&port->sysfs_device);
698 }
699
700 /**
701  * zfcp_sg_free_table - free memory used by scatterlists
702  * @sg: pointer to scatterlist
703  * @count: number of scatterlist which are to be free'ed
704  * the scatterlist are expected to reference pages always
705  */
706 void zfcp_sg_free_table(struct scatterlist *sg, int count)
707 {
708         int i;
709
710         for (i = 0; i < count; i++, sg++)
711                 if (sg)
712                         free_page((unsigned long) sg_virt(sg));
713                 else
714                         break;
715 }
716
717 /**
718  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
719  * @sg: pointer to struct scatterlist
720  * @count: number of scatterlists which should be assigned with buffers
721  * of size page
722  *
723  * Returns: 0 on success, -ENOMEM otherwise
724  */
725 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
726 {
727         void *addr;
728         int i;
729
730         sg_init_table(sg, count);
731         for (i = 0; i < count; i++, sg++) {
732                 addr = (void *) get_zeroed_page(GFP_KERNEL);
733                 if (!addr) {
734                         zfcp_sg_free_table(sg, i);
735                         return -ENOMEM;
736                 }
737                 sg_set_buf(sg, addr, PAGE_SIZE);
738         }
739         return 0;
740 }