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