Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd
[pandora-kernel.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, 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         unit = zfcp_unit_enqueue(port, lun);
77         if (IS_ERR(unit))
78                 goto out_unit;
79
80         zfcp_erp_unit_reopen(unit, 0, "auidc_1", NULL);
81         zfcp_erp_wait(adapter);
82         flush_work(&unit->scsi_work);
83
84 out_unit:
85         put_device(&port->dev);
86 out_port:
87         zfcp_ccw_adapter_put(adapter);
88 out_ccw_device:
89         put_device(&cdev->dev);
90         return;
91 }
92
93 static void __init zfcp_init_device_setup(char *devstr)
94 {
95         char *token;
96         char *str, *str_saved;
97         char busid[ZFCP_BUS_ID_SIZE];
98         u64 wwpn, lun;
99
100         /* duplicate devstr and keep the original for sysfs presentation*/
101         str_saved = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
102         str = str_saved;
103         if (!str)
104                 return;
105
106         strcpy(str, devstr);
107
108         token = strsep(&str, ",");
109         if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
110                 goto err_out;
111         strncpy(busid, token, ZFCP_BUS_ID_SIZE);
112
113         token = strsep(&str, ",");
114         if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
115                 goto err_out;
116
117         token = strsep(&str, ",");
118         if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
119                 goto err_out;
120
121         kfree(str_saved);
122         zfcp_init_device_configure(busid, wwpn, lun);
123         return;
124
125 err_out:
126         kfree(str_saved);
127         pr_err("%s is not a valid SCSI device\n", devstr);
128 }
129
130 static int __init zfcp_module_init(void)
131 {
132         int retval = -ENOMEM;
133
134         zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
135                                         sizeof(struct zfcp_fc_gpn_ft_req));
136         if (!zfcp_data.gpn_ft_cache)
137                 goto out;
138
139         zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
140                                         sizeof(struct fsf_qtcb));
141         if (!zfcp_data.qtcb_cache)
142                 goto out_qtcb_cache;
143
144         zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
145                                         sizeof(struct fsf_status_read_buffer));
146         if (!zfcp_data.sr_buffer_cache)
147                 goto out_sr_cache;
148
149         zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
150                                         sizeof(struct zfcp_fc_gid_pn));
151         if (!zfcp_data.gid_pn_cache)
152                 goto out_gid_cache;
153
154         zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
155                                         sizeof(struct zfcp_fc_els_adisc));
156         if (!zfcp_data.adisc_cache)
157                 goto out_adisc_cache;
158
159         zfcp_data.scsi_transport_template =
160                 fc_attach_transport(&zfcp_transport_functions);
161         if (!zfcp_data.scsi_transport_template)
162                 goto out_transport;
163
164         retval = misc_register(&zfcp_cfdc_misc);
165         if (retval) {
166                 pr_err("Registering the misc device zfcp_cfdc failed\n");
167                 goto out_misc;
168         }
169
170         retval = ccw_driver_register(&zfcp_ccw_driver);
171         if (retval) {
172                 pr_err("The zfcp device driver could not register with "
173                        "the common I/O layer\n");
174                 goto out_ccw_register;
175         }
176
177         if (init_device)
178                 zfcp_init_device_setup(init_device);
179         return 0;
180
181 out_ccw_register:
182         misc_deregister(&zfcp_cfdc_misc);
183 out_misc:
184         fc_release_transport(zfcp_data.scsi_transport_template);
185 out_transport:
186         kmem_cache_destroy(zfcp_data.adisc_cache);
187 out_adisc_cache:
188         kmem_cache_destroy(zfcp_data.gid_pn_cache);
189 out_gid_cache:
190         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
191 out_sr_cache:
192         kmem_cache_destroy(zfcp_data.qtcb_cache);
193 out_qtcb_cache:
194         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
195 out:
196         return retval;
197 }
198
199 module_init(zfcp_module_init);
200
201 static void __exit zfcp_module_exit(void)
202 {
203         ccw_driver_unregister(&zfcp_ccw_driver);
204         misc_deregister(&zfcp_cfdc_misc);
205         fc_release_transport(zfcp_data.scsi_transport_template);
206         kmem_cache_destroy(zfcp_data.adisc_cache);
207         kmem_cache_destroy(zfcp_data.gid_pn_cache);
208         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
209         kmem_cache_destroy(zfcp_data.qtcb_cache);
210         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
211 }
212
213 module_exit(zfcp_module_exit);
214
215 /**
216  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
217  * @port: pointer to port to search for unit
218  * @fcp_lun: FCP LUN to search for
219  *
220  * Returns: pointer to zfcp_unit or NULL
221  */
222 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
223 {
224         unsigned long flags;
225         struct zfcp_unit *unit;
226
227         read_lock_irqsave(&port->unit_list_lock, flags);
228         list_for_each_entry(unit, &port->unit_list, list)
229                 if (unit->fcp_lun == fcp_lun) {
230                         if (!get_device(&unit->dev))
231                                 unit = NULL;
232                         read_unlock_irqrestore(&port->unit_list_lock, flags);
233                         return unit;
234                 }
235         read_unlock_irqrestore(&port->unit_list_lock, flags);
236         return NULL;
237 }
238
239 /**
240  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
241  * @adapter: pointer to adapter to search for port
242  * @wwpn: wwpn to search for
243  *
244  * Returns: pointer to zfcp_port or NULL
245  */
246 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
247                                         u64 wwpn)
248 {
249         unsigned long flags;
250         struct zfcp_port *port;
251
252         read_lock_irqsave(&adapter->port_list_lock, flags);
253         list_for_each_entry(port, &adapter->port_list, list)
254                 if (port->wwpn == wwpn) {
255                         if (!get_device(&port->dev))
256                                 port = NULL;
257                         read_unlock_irqrestore(&adapter->port_list_lock, flags);
258                         return port;
259                 }
260         read_unlock_irqrestore(&adapter->port_list_lock, flags);
261         return NULL;
262 }
263
264 /**
265  * zfcp_unit_release - dequeue unit
266  * @dev: pointer to device
267  *
268  * waits until all work is done on unit and removes it then from the unit->list
269  * of the associated port.
270  */
271 static void zfcp_unit_release(struct device *dev)
272 {
273         struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
274
275         put_device(&unit->port->dev);
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->dev);
293
294         unit = zfcp_get_unit_by_lun(port, fcp_lun);
295         if (unit) {
296                 put_device(&unit->dev);
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->dev.parent = &port->dev;
308         unit->dev.release = zfcp_unit_release;
309
310         if (dev_set_name(&unit->dev, "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->dev)) {
328                 put_device(&unit->dev);
329                 goto err_out;
330         }
331
332         if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs))
333                 goto err_out_put;
334
335         write_lock_irq(&port->unit_list_lock);
336         list_add_tail(&unit->list, &port->unit_list);
337         write_unlock_irq(&port->unit_list_lock);
338
339         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
340
341         return unit;
342
343 err_out_put:
344         device_unregister(&unit->dev);
345 err_out:
346         put_device(&port->dev);
347         return ERR_PTR(retval);
348 }
349
350 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
351 {
352         adapter->pool.erp_req =
353                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
354         if (!adapter->pool.erp_req)
355                 return -ENOMEM;
356
357         adapter->pool.gid_pn_req =
358                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
359         if (!adapter->pool.gid_pn_req)
360                 return -ENOMEM;
361
362         adapter->pool.scsi_req =
363                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
364         if (!adapter->pool.scsi_req)
365                 return -ENOMEM;
366
367         adapter->pool.scsi_abort =
368                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
369         if (!adapter->pool.scsi_abort)
370                 return -ENOMEM;
371
372         adapter->pool.status_read_req =
373                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
374                                             sizeof(struct zfcp_fsf_req));
375         if (!adapter->pool.status_read_req)
376                 return -ENOMEM;
377
378         adapter->pool.qtcb_pool =
379                 mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
380         if (!adapter->pool.qtcb_pool)
381                 return -ENOMEM;
382
383         adapter->pool.status_read_data =
384                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
385                                          zfcp_data.sr_buffer_cache);
386         if (!adapter->pool.status_read_data)
387                 return -ENOMEM;
388
389         adapter->pool.gid_pn =
390                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
391         if (!adapter->pool.gid_pn)
392                 return -ENOMEM;
393
394         return 0;
395 }
396
397 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
398 {
399         if (adapter->pool.erp_req)
400                 mempool_destroy(adapter->pool.erp_req);
401         if (adapter->pool.scsi_req)
402                 mempool_destroy(adapter->pool.scsi_req);
403         if (adapter->pool.scsi_abort)
404                 mempool_destroy(adapter->pool.scsi_abort);
405         if (adapter->pool.qtcb_pool)
406                 mempool_destroy(adapter->pool.qtcb_pool);
407         if (adapter->pool.status_read_req)
408                 mempool_destroy(adapter->pool.status_read_req);
409         if (adapter->pool.status_read_data)
410                 mempool_destroy(adapter->pool.status_read_data);
411         if (adapter->pool.gid_pn)
412                 mempool_destroy(adapter->pool.gid_pn);
413 }
414
415 /**
416  * zfcp_status_read_refill - refill the long running status_read_requests
417  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
418  *
419  * Returns: 0 on success, 1 otherwise
420  *
421  * if there are 16 or more status_read requests missing an adapter_reopen
422  * is triggered
423  */
424 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
425 {
426         while (atomic_read(&adapter->stat_miss) > 0)
427                 if (zfcp_fsf_status_read(adapter->qdio)) {
428                         if (atomic_read(&adapter->stat_miss) >=
429                             adapter->stat_read_buf_num) {
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         /* report size limit per scatter-gather segment */
550         adapter->dma_parms.max_segment_size = ZFCP_QDIO_SBALE_LEN;
551         adapter->ccw_device->dev.dma_parms = &adapter->dma_parms;
552
553         if (!zfcp_adapter_scsi_register(adapter))
554                 return adapter;
555
556 failed:
557         zfcp_adapter_unregister(adapter);
558         return ERR_PTR(-ENOMEM);
559 }
560
561 void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
562 {
563         struct ccw_device *cdev = adapter->ccw_device;
564
565         cancel_work_sync(&adapter->scan_work);
566         cancel_work_sync(&adapter->stat_work);
567         zfcp_destroy_adapter_work_queue(adapter);
568
569         zfcp_fc_wka_ports_force_offline(adapter->gs);
570         zfcp_adapter_scsi_unregister(adapter);
571         sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
572
573         zfcp_erp_thread_kill(adapter);
574         zfcp_dbf_adapter_unregister(adapter->dbf);
575         zfcp_qdio_destroy(adapter->qdio);
576
577         zfcp_ccw_adapter_put(adapter); /* final put to release */
578 }
579
580 /**
581  * zfcp_adapter_release - remove the adapter from the resource list
582  * @ref: pointer to struct kref
583  * locks:       adapter list write lock is assumed to be held by caller
584  */
585 void zfcp_adapter_release(struct kref *ref)
586 {
587         struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
588                                                     ref);
589         struct ccw_device *cdev = adapter->ccw_device;
590
591         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
592         zfcp_fc_gs_destroy(adapter);
593         zfcp_free_low_mem_buffers(adapter);
594         kfree(adapter->req_list);
595         kfree(adapter->fc_stats);
596         kfree(adapter->stats_reset_data);
597         kfree(adapter);
598         put_device(&cdev->dev);
599 }
600
601 /**
602  * zfcp_device_unregister - remove port, unit from system
603  * @dev: reference to device which is to be removed
604  * @grp: related reference to attribute group
605  *
606  * Helper function to unregister port, unit from system
607  */
608 void zfcp_device_unregister(struct device *dev,
609                             const struct attribute_group *grp)
610 {
611         sysfs_remove_group(&dev->kobj, grp);
612         device_unregister(dev);
613 }
614
615 static void zfcp_port_release(struct device *dev)
616 {
617         struct zfcp_port *port = container_of(dev, struct zfcp_port, dev);
618
619         zfcp_ccw_adapter_put(port->adapter);
620         kfree(port);
621 }
622
623 /**
624  * zfcp_port_enqueue - enqueue port to port list of adapter
625  * @adapter: adapter where remote port is added
626  * @wwpn: WWPN of the remote port to be enqueued
627  * @status: initial status for the port
628  * @d_id: destination id of the remote port to be enqueued
629  * Returns: pointer to enqueued port on success, ERR_PTR on error
630  *
631  * All port internal structures are set up and the sysfs entry is generated.
632  * d_id is used to enqueue ports with a well known address like the Directory
633  * Service for nameserver lookup.
634  */
635 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
636                                      u32 status, u32 d_id)
637 {
638         struct zfcp_port *port;
639         int retval = -ENOMEM;
640
641         kref_get(&adapter->ref);
642
643         port = zfcp_get_port_by_wwpn(adapter, wwpn);
644         if (port) {
645                 put_device(&port->dev);
646                 retval = -EEXIST;
647                 goto err_out;
648         }
649
650         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
651         if (!port)
652                 goto err_out;
653
654         rwlock_init(&port->unit_list_lock);
655         INIT_LIST_HEAD(&port->unit_list);
656
657         INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
658         INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
659         INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
660
661         port->adapter = adapter;
662         port->d_id = d_id;
663         port->wwpn = wwpn;
664         port->rport_task = RPORT_NONE;
665         port->dev.parent = &adapter->ccw_device->dev;
666         port->dev.release = zfcp_port_release;
667
668         if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
669                 kfree(port);
670                 goto err_out;
671         }
672         retval = -EINVAL;
673
674         if (device_register(&port->dev)) {
675                 put_device(&port->dev);
676                 goto err_out;
677         }
678
679         if (sysfs_create_group(&port->dev.kobj,
680                                &zfcp_sysfs_port_attrs))
681                 goto err_out_put;
682
683         write_lock_irq(&adapter->port_list_lock);
684         list_add_tail(&port->list, &adapter->port_list);
685         write_unlock_irq(&adapter->port_list_lock);
686
687         atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
688
689         return port;
690
691 err_out_put:
692         device_unregister(&port->dev);
693 err_out:
694         zfcp_ccw_adapter_put(adapter);
695         return ERR_PTR(retval);
696 }
697
698 /**
699  * zfcp_sg_free_table - free memory used by scatterlists
700  * @sg: pointer to scatterlist
701  * @count: number of scatterlist which are to be free'ed
702  * the scatterlist are expected to reference pages always
703  */
704 void zfcp_sg_free_table(struct scatterlist *sg, int count)
705 {
706         int i;
707
708         for (i = 0; i < count; i++, sg++)
709                 if (sg)
710                         free_page((unsigned long) sg_virt(sg));
711                 else
712                         break;
713 }
714
715 /**
716  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
717  * @sg: pointer to struct scatterlist
718  * @count: number of scatterlists which should be assigned with buffers
719  * of size page
720  *
721  * Returns: 0 on success, -ENOMEM otherwise
722  */
723 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
724 {
725         void *addr;
726         int i;
727
728         sg_init_table(sg, count);
729         for (i = 0; i < count; i++, sg++) {
730                 addr = (void *) get_zeroed_page(GFP_KERNEL);
731                 if (!addr) {
732                         zfcp_sg_free_table(sg, i);
733                         return -ENOMEM;
734                 }
735                 sg_set_buf(sg, addr, PAGE_SIZE);
736         }
737         return 0;
738 }