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