Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
[linux-2.6] / 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, &zfcp_data.init_wwpn))
92                 goto err_out;
93
94         token = strsep(&str, ",");
95         if (!token || strict_strtoull(token, 0, &zfcp_data.init_fcp_lun))
96                 goto err_out;
97
98         kfree(str);
99         return 1;
100
101  err_out:
102         kfree(str);
103         pr_err("zfcp: Parse error for device parameter string %s, "
104                "device not attached.\n", devstr);
105         return 0;
106 }
107
108 static struct zfcp_adapter *zfcp_get_adapter_by_busid(char *bus_id)
109 {
110         struct zfcp_adapter *adapter;
111
112         list_for_each_entry(adapter, &zfcp_data.adapter_list_head, list)
113                 if ((strncmp(bus_id, adapter->ccw_device->dev.bus_id,
114                              BUS_ID_SIZE) == 0) &&
115                     !(atomic_read(&adapter->status) &
116                       ZFCP_STATUS_COMMON_REMOVE))
117                     return adapter;
118         return NULL;
119 }
120
121 static void __init zfcp_init_device_configure(void)
122 {
123         struct zfcp_adapter *adapter;
124         struct zfcp_port *port;
125         struct zfcp_unit *unit;
126
127         down(&zfcp_data.config_sema);
128         read_lock_irq(&zfcp_data.config_lock);
129         adapter = zfcp_get_adapter_by_busid(zfcp_data.init_busid);
130         if (adapter)
131                 zfcp_adapter_get(adapter);
132         read_unlock_irq(&zfcp_data.config_lock);
133
134         if (!adapter)
135                 goto out_adapter;
136         port = zfcp_port_enqueue(adapter, zfcp_data.init_wwpn, 0, 0);
137         if (IS_ERR(port))
138                 goto out_port;
139         unit = zfcp_unit_enqueue(port, zfcp_data.init_fcp_lun);
140         if (IS_ERR(unit))
141                 goto out_unit;
142         up(&zfcp_data.config_sema);
143         ccw_device_set_online(adapter->ccw_device);
144         zfcp_erp_wait(adapter);
145         down(&zfcp_data.config_sema);
146         zfcp_unit_put(unit);
147 out_unit:
148         zfcp_port_put(port);
149 out_port:
150         zfcp_adapter_put(adapter);
151 out_adapter:
152         up(&zfcp_data.config_sema);
153         return;
154 }
155
156 static struct kmem_cache *zfcp_cache_create(int size, char *name)
157 {
158         int align = 1;
159         while ((size - align) > 0)
160                 align <<= 1;
161         return kmem_cache_create(name , size, align, 0, NULL);
162 }
163
164 static int __init zfcp_module_init(void)
165 {
166         int retval = -ENOMEM;
167
168         zfcp_data.fsf_req_qtcb_cache = zfcp_cache_create(
169                         sizeof(struct zfcp_fsf_req_qtcb), "zfcp_fsf");
170         if (!zfcp_data.fsf_req_qtcb_cache)
171                 goto out;
172
173         zfcp_data.sr_buffer_cache = zfcp_cache_create(
174                         sizeof(struct fsf_status_read_buffer), "zfcp_sr");
175         if (!zfcp_data.sr_buffer_cache)
176                 goto out_sr_cache;
177
178         zfcp_data.gid_pn_cache = zfcp_cache_create(
179                         sizeof(struct zfcp_gid_pn_data), "zfcp_gid");
180         if (!zfcp_data.gid_pn_cache)
181                 goto out_gid_cache;
182
183         INIT_LIST_HEAD(&zfcp_data.adapter_list_head);
184         INIT_LIST_HEAD(&zfcp_data.adapter_remove_lh);
185
186         sema_init(&zfcp_data.config_sema, 1);
187         rwlock_init(&zfcp_data.config_lock);
188
189         zfcp_data.scsi_transport_template =
190                 fc_attach_transport(&zfcp_transport_functions);
191         if (!zfcp_data.scsi_transport_template)
192                 goto out_transport;
193
194         retval = misc_register(&zfcp_cfdc_misc);
195         if (retval) {
196                 pr_err("zfcp: registration of misc device zfcp_cfdc failed\n");
197                 goto out_misc;
198         }
199
200         retval = zfcp_ccw_register();
201         if (retval) {
202                 pr_err("zfcp: Registration with common I/O layer failed.\n");
203                 goto out_ccw_register;
204         }
205
206         if (zfcp_device_setup(device))
207                 zfcp_init_device_configure();
208
209         goto out;
210
211 out_ccw_register:
212         misc_deregister(&zfcp_cfdc_misc);
213 out_misc:
214         fc_release_transport(zfcp_data.scsi_transport_template);
215 out_transport:
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.fsf_req_qtcb_cache);
221 out:
222         return retval;
223 }
224
225 module_init(zfcp_module_init);
226
227 /**
228  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
229  * @port: pointer to port to search for unit
230  * @fcp_lun: FCP LUN to search for
231  *
232  * Returns: pointer to zfcp_unit or NULL
233  */
234 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port,
235                                        fcp_lun_t fcp_lun)
236 {
237         struct zfcp_unit *unit;
238
239         list_for_each_entry(unit, &port->unit_list_head, list)
240                 if ((unit->fcp_lun == fcp_lun) &&
241                     !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE))
242                     return unit;
243         return NULL;
244 }
245
246 /**
247  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
248  * @adapter: pointer to adapter to search for port
249  * @wwpn: wwpn to search for
250  *
251  * Returns: pointer to zfcp_port or NULL
252  */
253 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
254                                         wwn_t wwpn)
255 {
256         struct zfcp_port *port;
257
258         list_for_each_entry(port, &adapter->port_list_head, list)
259                 if ((port->wwpn == wwpn) && !(atomic_read(&port->status) &
260                       (ZFCP_STATUS_PORT_NO_WWPN | ZFCP_STATUS_COMMON_REMOVE)))
261                         return port;
262         return NULL;
263 }
264
265 static void zfcp_sysfs_unit_release(struct device *dev)
266 {
267         kfree(container_of(dev, struct zfcp_unit, sysfs_device));
268 }
269
270 /**
271  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
272  * @port: pointer to port where unit is added
273  * @fcp_lun: FCP LUN of unit to be enqueued
274  * Returns: pointer to enqueued unit on success, ERR_PTR on error
275  * Locks: config_sema must be held to serialize changes to the unit list
276  *
277  * Sets up some unit internal structures and creates sysfs entry.
278  */
279 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
280 {
281         struct zfcp_unit *unit;
282
283         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
284         if (!unit)
285                 return ERR_PTR(-ENOMEM);
286
287         atomic_set(&unit->refcount, 0);
288         init_waitqueue_head(&unit->remove_wq);
289
290         unit->port = port;
291         unit->fcp_lun = fcp_lun;
292
293         snprintf(unit->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx", fcp_lun);
294         unit->sysfs_device.parent = &port->sysfs_device;
295         unit->sysfs_device.release = zfcp_sysfs_unit_release;
296         dev_set_drvdata(&unit->sysfs_device, unit);
297
298         /* mark unit unusable as long as sysfs registration is not complete */
299         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
300
301         spin_lock_init(&unit->latencies.lock);
302         unit->latencies.write.channel.min = 0xFFFFFFFF;
303         unit->latencies.write.fabric.min = 0xFFFFFFFF;
304         unit->latencies.read.channel.min = 0xFFFFFFFF;
305         unit->latencies.read.fabric.min = 0xFFFFFFFF;
306         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
307         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
308
309         read_lock_irq(&zfcp_data.config_lock);
310         if (zfcp_get_unit_by_lun(port, fcp_lun)) {
311                 read_unlock_irq(&zfcp_data.config_lock);
312                 goto err_out_free;
313         }
314         read_unlock_irq(&zfcp_data.config_lock);
315
316         if (device_register(&unit->sysfs_device))
317                 goto err_out_free;
318
319         if (sysfs_create_group(&unit->sysfs_device.kobj,
320                                &zfcp_sysfs_unit_attrs)) {
321                 device_unregister(&unit->sysfs_device);
322                 return ERR_PTR(-EIO);
323         }
324
325         zfcp_unit_get(unit);
326         unit->scsi_lun = scsilun_to_int((struct scsi_lun *)&unit->fcp_lun);
327
328         write_lock_irq(&zfcp_data.config_lock);
329         list_add_tail(&unit->list, &port->unit_list_head);
330         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
331         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
332
333         write_unlock_irq(&zfcp_data.config_lock);
334
335         port->units++;
336         zfcp_port_get(port);
337
338         return unit;
339
340 err_out_free:
341         kfree(unit);
342         return ERR_PTR(-EINVAL);
343 }
344
345 /**
346  * zfcp_unit_dequeue - dequeue unit
347  * @unit: pointer to zfcp_unit
348  *
349  * waits until all work is done on unit and removes it then from the unit->list
350  * of the associated port.
351  */
352 void zfcp_unit_dequeue(struct zfcp_unit *unit)
353 {
354         zfcp_unit_wait(unit);
355         write_lock_irq(&zfcp_data.config_lock);
356         list_del(&unit->list);
357         write_unlock_irq(&zfcp_data.config_lock);
358         unit->port->units--;
359         zfcp_port_put(unit->port);
360         sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
361         device_unregister(&unit->sysfs_device);
362 }
363
364 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
365 {
366         /* must only be called with zfcp_data.config_sema taken */
367         adapter->pool.fsf_req_erp =
368                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
369         if (!adapter->pool.fsf_req_erp)
370                 return -ENOMEM;
371
372         adapter->pool.fsf_req_scsi =
373                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
374         if (!adapter->pool.fsf_req_scsi)
375                 return -ENOMEM;
376
377         adapter->pool.fsf_req_abort =
378                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
379         if (!adapter->pool.fsf_req_abort)
380                 return -ENOMEM;
381
382         adapter->pool.fsf_req_status_read =
383                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
384                                             sizeof(struct zfcp_fsf_req));
385         if (!adapter->pool.fsf_req_status_read)
386                 return -ENOMEM;
387
388         adapter->pool.data_status_read =
389                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
390                                          zfcp_data.sr_buffer_cache);
391         if (!adapter->pool.data_status_read)
392                 return -ENOMEM;
393
394         adapter->pool.data_gid_pn =
395                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
396         if (!adapter->pool.data_gid_pn)
397                 return -ENOMEM;
398
399         return 0;
400 }
401
402 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
403 {
404         /* zfcp_data.config_sema must be held */
405         if (adapter->pool.fsf_req_erp)
406                 mempool_destroy(adapter->pool.fsf_req_erp);
407         if (adapter->pool.fsf_req_scsi)
408                 mempool_destroy(adapter->pool.fsf_req_scsi);
409         if (adapter->pool.fsf_req_abort)
410                 mempool_destroy(adapter->pool.fsf_req_abort);
411         if (adapter->pool.fsf_req_status_read)
412                 mempool_destroy(adapter->pool.fsf_req_status_read);
413         if (adapter->pool.data_status_read)
414                 mempool_destroy(adapter->pool.data_status_read);
415         if (adapter->pool.data_gid_pn)
416                 mempool_destroy(adapter->pool.data_gid_pn);
417 }
418
419 static void zfcp_dummy_release(struct device *dev)
420 {
421         return;
422 }
423
424 /**
425  * zfcp_status_read_refill - refill the long running status_read_requests
426  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
427  *
428  * Returns: 0 on success, 1 otherwise
429  *
430  * if there are 16 or more status_read requests missing an adapter_reopen
431  * is triggered
432  */
433 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
434 {
435         while (atomic_read(&adapter->stat_miss) > 0)
436                 if (zfcp_fsf_status_read(adapter)) {
437                         if (atomic_read(&adapter->stat_miss) >= 16) {
438                                 zfcp_erp_adapter_reopen(adapter, 0, 103, NULL);
439                                 return 1;
440                         }
441                         break;
442                 } else
443                         atomic_dec(&adapter->stat_miss);
444         return 0;
445 }
446
447 static void _zfcp_status_read_scheduler(struct work_struct *work)
448 {
449         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
450                                              stat_work));
451 }
452
453 static int zfcp_nameserver_enqueue(struct zfcp_adapter *adapter)
454 {
455         struct zfcp_port *port;
456
457         port = zfcp_port_enqueue(adapter, 0, ZFCP_STATUS_PORT_WKA,
458                                  ZFCP_DID_DIRECTORY_SERVICE);
459         if (IS_ERR(port))
460                 return PTR_ERR(port);
461         zfcp_port_put(port);
462
463         return 0;
464 }
465
466 /**
467  * zfcp_adapter_enqueue - enqueue a new adapter to the list
468  * @ccw_device: pointer to the struct cc_device
469  *
470  * Returns:     0             if a new adapter was successfully enqueued
471  *              -ENOMEM       if alloc failed
472  * Enqueues an adapter at the end of the adapter list in the driver data.
473  * All adapter internal structures are set up.
474  * Proc-fs entries are also created.
475  * locks:       config_sema must be held to serialise changes to the adapter list
476  */
477 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
478 {
479         struct zfcp_adapter *adapter;
480
481         /*
482          * Note: It is safe to release the list_lock, as any list changes
483          * are protected by the config_sema, which must be held to get here
484          */
485
486         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
487         if (!adapter)
488                 return -ENOMEM;
489
490         ccw_device->handler = NULL;
491         adapter->ccw_device = ccw_device;
492         atomic_set(&adapter->refcount, 0);
493
494         if (zfcp_qdio_allocate(adapter))
495                 goto qdio_allocate_failed;
496
497         if (zfcp_allocate_low_mem_buffers(adapter))
498                 goto failed_low_mem_buffers;
499
500         if (zfcp_reqlist_alloc(adapter))
501                 goto failed_low_mem_buffers;
502
503         if (zfcp_adapter_debug_register(adapter))
504                 goto debug_register_failed;
505
506         init_waitqueue_head(&adapter->remove_wq);
507         init_waitqueue_head(&adapter->erp_thread_wqh);
508         init_waitqueue_head(&adapter->erp_done_wqh);
509
510         INIT_LIST_HEAD(&adapter->port_list_head);
511         INIT_LIST_HEAD(&adapter->port_remove_lh);
512         INIT_LIST_HEAD(&adapter->erp_ready_head);
513         INIT_LIST_HEAD(&adapter->erp_running_head);
514
515         spin_lock_init(&adapter->req_list_lock);
516
517         spin_lock_init(&adapter->hba_dbf_lock);
518         spin_lock_init(&adapter->san_dbf_lock);
519         spin_lock_init(&adapter->scsi_dbf_lock);
520         spin_lock_init(&adapter->rec_dbf_lock);
521         spin_lock_init(&adapter->req_q.lock);
522
523         rwlock_init(&adapter->erp_lock);
524         rwlock_init(&adapter->abort_lock);
525
526         sema_init(&adapter->erp_ready_sem, 0);
527
528         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
529         INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);
530
531         /* mark adapter unusable as long as sysfs registration is not complete */
532         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
533
534         dev_set_drvdata(&ccw_device->dev, adapter);
535
536         if (sysfs_create_group(&ccw_device->dev.kobj,
537                                &zfcp_sysfs_adapter_attrs))
538                 goto sysfs_failed;
539
540         adapter->generic_services.parent = &adapter->ccw_device->dev;
541         adapter->generic_services.release = zfcp_dummy_release;
542         snprintf(adapter->generic_services.bus_id, BUS_ID_SIZE,
543                  "generic_services");
544
545         if (device_register(&adapter->generic_services))
546                 goto generic_services_failed;
547
548         write_lock_irq(&zfcp_data.config_lock);
549         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
550         list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
551         write_unlock_irq(&zfcp_data.config_lock);
552
553         zfcp_data.adapters++;
554
555         zfcp_nameserver_enqueue(adapter);
556
557         return 0;
558
559 generic_services_failed:
560         sysfs_remove_group(&ccw_device->dev.kobj,
561                            &zfcp_sysfs_adapter_attrs);
562 sysfs_failed:
563         zfcp_adapter_debug_unregister(adapter);
564 debug_register_failed:
565         dev_set_drvdata(&ccw_device->dev, NULL);
566         kfree(adapter->req_list);
567 failed_low_mem_buffers:
568         zfcp_free_low_mem_buffers(adapter);
569 qdio_allocate_failed:
570         zfcp_qdio_free(adapter);
571         kfree(adapter);
572         return -ENOMEM;
573 }
574
575 /**
576  * zfcp_adapter_dequeue - remove the adapter from the resource list
577  * @adapter: pointer to struct zfcp_adapter which should be removed
578  * locks:       adapter list write lock is assumed to be held by caller
579  */
580 void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
581 {
582         int retval = 0;
583         unsigned long flags;
584
585         cancel_work_sync(&adapter->scan_work);
586         cancel_work_sync(&adapter->stat_work);
587         zfcp_adapter_scsi_unregister(adapter);
588         device_unregister(&adapter->generic_services);
589         sysfs_remove_group(&adapter->ccw_device->dev.kobj,
590                            &zfcp_sysfs_adapter_attrs);
591         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
592         /* sanity check: no pending FSF requests */
593         spin_lock_irqsave(&adapter->req_list_lock, flags);
594         retval = zfcp_reqlist_isempty(adapter);
595         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
596         if (!retval)
597                 return;
598
599         zfcp_adapter_debug_unregister(adapter);
600
601         /* remove specified adapter data structure from list */
602         write_lock_irq(&zfcp_data.config_lock);
603         list_del(&adapter->list);
604         write_unlock_irq(&zfcp_data.config_lock);
605
606         /* decrease number of adapters in list */
607         zfcp_data.adapters--;
608
609         zfcp_qdio_free(adapter);
610
611         zfcp_free_low_mem_buffers(adapter);
612         kfree(adapter->req_list);
613         kfree(adapter->fc_stats);
614         kfree(adapter->stats_reset_data);
615         kfree(adapter);
616 }
617
618 static void zfcp_sysfs_port_release(struct device *dev)
619 {
620         kfree(container_of(dev, struct zfcp_port, sysfs_device));
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  * Locks: config_sema must be held to serialize changes to the port list
631  *
632  * All port internal structures are set up and the sysfs entry is generated.
633  * d_id is used to enqueue ports with a well known address like the Directory
634  * Service for nameserver lookup.
635  */
636 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, wwn_t wwpn,
637                                      u32 status, u32 d_id)
638 {
639         struct zfcp_port *port;
640         int retval;
641         char *bus_id;
642
643         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
644         if (!port)
645                 return ERR_PTR(-ENOMEM);
646
647         init_waitqueue_head(&port->remove_wq);
648
649         INIT_LIST_HEAD(&port->unit_list_head);
650         INIT_LIST_HEAD(&port->unit_remove_lh);
651
652         port->adapter = adapter;
653         port->d_id = d_id;
654         port->wwpn = wwpn;
655
656         /* mark port unusable as long as sysfs registration is not complete */
657         atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
658         atomic_set(&port->refcount, 0);
659
660         if (status & ZFCP_STATUS_PORT_WKA) {
661                 switch (d_id) {
662                 case ZFCP_DID_DIRECTORY_SERVICE:
663                         bus_id = "directory";
664                         break;
665                 case ZFCP_DID_MANAGEMENT_SERVICE:
666                         bus_id = "management";
667                         break;
668                 case ZFCP_DID_KEY_DISTRIBUTION_SERVICE:
669                         bus_id = "key_distribution";
670                         break;
671                 case ZFCP_DID_ALIAS_SERVICE:
672                         bus_id = "alias";
673                         break;
674                 case ZFCP_DID_TIME_SERVICE:
675                         bus_id = "time";
676                         break;
677                 default:
678                         kfree(port);
679                         return ERR_PTR(-EINVAL);
680                 }
681                 snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE, "%s", bus_id);
682                 port->sysfs_device.parent = &adapter->generic_services;
683         } else {
684                 snprintf(port->sysfs_device.bus_id,
685                          BUS_ID_SIZE, "0x%016llx", wwpn);
686                 port->sysfs_device.parent = &adapter->ccw_device->dev;
687         }
688
689         port->sysfs_device.release = zfcp_sysfs_port_release;
690         dev_set_drvdata(&port->sysfs_device, port);
691
692         read_lock_irq(&zfcp_data.config_lock);
693         if (!(status & ZFCP_STATUS_PORT_NO_WWPN))
694                 if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
695                         read_unlock_irq(&zfcp_data.config_lock);
696                         goto err_out_free;
697                 }
698         read_unlock_irq(&zfcp_data.config_lock);
699
700         if (device_register(&port->sysfs_device))
701                 goto err_out_free;
702
703         if (status & ZFCP_STATUS_PORT_WKA)
704                 retval = sysfs_create_group(&port->sysfs_device.kobj,
705                                             &zfcp_sysfs_ns_port_attrs);
706         else
707                 retval = sysfs_create_group(&port->sysfs_device.kobj,
708                                             &zfcp_sysfs_port_attrs);
709
710         if (retval) {
711                 device_unregister(&port->sysfs_device);
712                 goto err_out;
713         }
714
715         zfcp_port_get(port);
716
717         write_lock_irq(&zfcp_data.config_lock);
718         list_add_tail(&port->list, &adapter->port_list_head);
719         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
720         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
721         if (d_id == ZFCP_DID_DIRECTORY_SERVICE)
722                 if (!adapter->nameserver_port)
723                         adapter->nameserver_port = port;
724         adapter->ports++;
725
726         write_unlock_irq(&zfcp_data.config_lock);
727
728         zfcp_adapter_get(adapter);
729         return port;
730
731 err_out_free:
732         kfree(port);
733 err_out:
734         return ERR_PTR(-EINVAL);
735 }
736
737 /**
738  * zfcp_port_dequeue - dequeues a port from the port list of the adapter
739  * @port: pointer to struct zfcp_port which should be removed
740  */
741 void zfcp_port_dequeue(struct zfcp_port *port)
742 {
743         zfcp_port_wait(port);
744         write_lock_irq(&zfcp_data.config_lock);
745         list_del(&port->list);
746         port->adapter->ports--;
747         write_unlock_irq(&zfcp_data.config_lock);
748         if (port->rport)
749                 fc_remote_port_delete(port->rport);
750         port->rport = NULL;
751         zfcp_adapter_put(port->adapter);
752         if (atomic_read(&port->status) & ZFCP_STATUS_PORT_WKA)
753                 sysfs_remove_group(&port->sysfs_device.kobj,
754                                    &zfcp_sysfs_ns_port_attrs);
755         else
756                 sysfs_remove_group(&port->sysfs_device.kobj,
757                                    &zfcp_sysfs_port_attrs);
758         device_unregister(&port->sysfs_device);
759 }
760
761 /**
762  * zfcp_sg_free_table - free memory used by scatterlists
763  * @sg: pointer to scatterlist
764  * @count: number of scatterlist which are to be free'ed
765  * the scatterlist are expected to reference pages always
766  */
767 void zfcp_sg_free_table(struct scatterlist *sg, int count)
768 {
769         int i;
770
771         for (i = 0; i < count; i++, sg++)
772                 if (sg)
773                         free_page((unsigned long) sg_virt(sg));
774                 else
775                         break;
776 }
777
778 /**
779  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
780  * @sg: pointer to struct scatterlist
781  * @count: number of scatterlists which should be assigned with buffers
782  * of size page
783  *
784  * Returns: 0 on success, -ENOMEM otherwise
785  */
786 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
787 {
788         void *addr;
789         int i;
790
791         sg_init_table(sg, count);
792         for (i = 0; i < count; i++, sg++) {
793                 addr = (void *) get_zeroed_page(GFP_KERNEL);
794                 if (!addr) {
795                         zfcp_sg_free_table(sg, i);
796                         return -ENOMEM;
797                 }
798                 sg_set_buf(sg, addr, PAGE_SIZE);
799         }
800         return 0;
801 }