[SCSI] zfcp: Update dbf calls
[safe/jmp/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, 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 zfcp_adapter *adapter;
84         struct zfcp_port *port;
85         struct zfcp_unit *unit;
86
87         down(&zfcp_data.config_sema);
88         read_lock_irq(&zfcp_data.config_lock);
89         adapter = zfcp_get_adapter_by_busid(busid);
90         if (adapter)
91                 zfcp_adapter_get(adapter);
92         read_unlock_irq(&zfcp_data.config_lock);
93
94         if (!adapter)
95                 goto out_adapter;
96         port = zfcp_port_enqueue(adapter, wwpn, 0, 0);
97         if (IS_ERR(port))
98                 goto out_port;
99         unit = zfcp_unit_enqueue(port, lun);
100         if (IS_ERR(unit))
101                 goto out_unit;
102         up(&zfcp_data.config_sema);
103         ccw_device_set_online(adapter->ccw_device);
104
105         zfcp_erp_wait(adapter);
106         flush_work(&unit->scsi_work);
107
108         down(&zfcp_data.config_sema);
109         zfcp_unit_put(unit);
110 out_unit:
111         zfcp_port_put(port);
112 out_port:
113         zfcp_adapter_put(adapter);
114 out_adapter:
115         up(&zfcp_data.config_sema);
116         return;
117 }
118
119 static void __init zfcp_init_device_setup(char *devstr)
120 {
121         char *token;
122         char *str;
123         char busid[ZFCP_BUS_ID_SIZE];
124         u64 wwpn, lun;
125
126         /* duplicate devstr and keep the original for sysfs presentation*/
127         str = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
128         if (!str)
129                 return;
130
131         strcpy(str, devstr);
132
133         token = strsep(&str, ",");
134         if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
135                 goto err_out;
136         strncpy(busid, token, ZFCP_BUS_ID_SIZE);
137
138         token = strsep(&str, ",");
139         if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
140                 goto err_out;
141
142         token = strsep(&str, ",");
143         if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
144                 goto err_out;
145
146         kfree(str);
147         zfcp_init_device_configure(busid, wwpn, lun);
148         return;
149
150  err_out:
151         kfree(str);
152         pr_err("%s is not a valid SCSI device\n", devstr);
153 }
154
155 static int __init zfcp_module_init(void)
156 {
157         int retval = -ENOMEM;
158
159         zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
160                                         sizeof(struct ct_iu_gpn_ft_req));
161         if (!zfcp_data.gpn_ft_cache)
162                 goto out;
163
164         zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
165                                         sizeof(struct fsf_qtcb));
166         if (!zfcp_data.qtcb_cache)
167                 goto out_qtcb_cache;
168
169         zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
170                                         sizeof(struct fsf_status_read_buffer));
171         if (!zfcp_data.sr_buffer_cache)
172                 goto out_sr_cache;
173
174         zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
175                                         sizeof(struct zfcp_gid_pn_data));
176         if (!zfcp_data.gid_pn_cache)
177                 goto out_gid_cache;
178
179         sema_init(&zfcp_data.config_sema, 1);
180         rwlock_init(&zfcp_data.config_lock);
181
182         zfcp_data.scsi_transport_template =
183                 fc_attach_transport(&zfcp_transport_functions);
184         if (!zfcp_data.scsi_transport_template)
185                 goto out_transport;
186
187         retval = misc_register(&zfcp_cfdc_misc);
188         if (retval) {
189                 pr_err("Registering the misc device zfcp_cfdc failed\n");
190                 goto out_misc;
191         }
192
193         retval = zfcp_ccw_register();
194         if (retval) {
195                 pr_err("The zfcp device driver could not register with "
196                        "the common I/O layer\n");
197                 goto out_ccw_register;
198         }
199
200         if (init_device)
201                 zfcp_init_device_setup(init_device);
202         return 0;
203
204 out_ccw_register:
205         misc_deregister(&zfcp_cfdc_misc);
206 out_misc:
207         fc_release_transport(zfcp_data.scsi_transport_template);
208 out_transport:
209         kmem_cache_destroy(zfcp_data.gid_pn_cache);
210 out_gid_cache:
211         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
212 out_sr_cache:
213         kmem_cache_destroy(zfcp_data.qtcb_cache);
214 out_qtcb_cache:
215         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
216 out:
217         return retval;
218 }
219
220 module_init(zfcp_module_init);
221
222 /**
223  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
224  * @port: pointer to port to search for unit
225  * @fcp_lun: FCP LUN to search for
226  *
227  * Returns: pointer to zfcp_unit or NULL
228  */
229 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
230 {
231         struct zfcp_unit *unit;
232
233         list_for_each_entry(unit, &port->unit_list_head, list)
234                 if ((unit->fcp_lun == fcp_lun) &&
235                     !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE))
236                     return unit;
237         return NULL;
238 }
239
240 /**
241  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
242  * @adapter: pointer to adapter to search for port
243  * @wwpn: wwpn to search for
244  *
245  * Returns: pointer to zfcp_port or NULL
246  */
247 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
248                                         u64 wwpn)
249 {
250         struct zfcp_port *port;
251
252         list_for_each_entry(port, &adapter->port_list_head, list)
253                 if ((port->wwpn == wwpn) &&
254                     !(atomic_read(&port->status) & ZFCP_STATUS_COMMON_REMOVE))
255                         return port;
256         return NULL;
257 }
258
259 static void zfcp_sysfs_unit_release(struct device *dev)
260 {
261         kfree(container_of(dev, struct zfcp_unit, sysfs_device));
262 }
263
264 /**
265  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
266  * @port: pointer to port where unit is added
267  * @fcp_lun: FCP LUN of unit to be enqueued
268  * Returns: pointer to enqueued unit on success, ERR_PTR on error
269  * Locks: config_sema must be held to serialize changes to the unit list
270  *
271  * Sets up some unit internal structures and creates sysfs entry.
272  */
273 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
274 {
275         struct zfcp_unit *unit;
276
277         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
278         if (!unit)
279                 return ERR_PTR(-ENOMEM);
280
281         atomic_set(&unit->refcount, 0);
282         init_waitqueue_head(&unit->remove_wq);
283         INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
284
285         unit->port = port;
286         unit->fcp_lun = fcp_lun;
287
288         dev_set_name(&unit->sysfs_device, "0x%016llx",
289                      (unsigned long long) fcp_lun);
290         unit->sysfs_device.parent = &port->sysfs_device;
291         unit->sysfs_device.release = zfcp_sysfs_unit_release;
292         dev_set_drvdata(&unit->sysfs_device, unit);
293
294         /* mark unit unusable as long as sysfs registration is not complete */
295         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
296
297         spin_lock_init(&unit->latencies.lock);
298         unit->latencies.write.channel.min = 0xFFFFFFFF;
299         unit->latencies.write.fabric.min = 0xFFFFFFFF;
300         unit->latencies.read.channel.min = 0xFFFFFFFF;
301         unit->latencies.read.fabric.min = 0xFFFFFFFF;
302         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
303         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
304
305         read_lock_irq(&zfcp_data.config_lock);
306         if (zfcp_get_unit_by_lun(port, fcp_lun)) {
307                 read_unlock_irq(&zfcp_data.config_lock);
308                 goto err_out_free;
309         }
310         read_unlock_irq(&zfcp_data.config_lock);
311
312         if (device_register(&unit->sysfs_device))
313                 goto err_out_free;
314
315         if (sysfs_create_group(&unit->sysfs_device.kobj,
316                                &zfcp_sysfs_unit_attrs)) {
317                 device_unregister(&unit->sysfs_device);
318                 return ERR_PTR(-EIO);
319         }
320
321         zfcp_unit_get(unit);
322
323         write_lock_irq(&zfcp_data.config_lock);
324         list_add_tail(&unit->list, &port->unit_list_head);
325         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
326         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
327
328         write_unlock_irq(&zfcp_data.config_lock);
329
330         zfcp_port_get(port);
331
332         return unit;
333
334 err_out_free:
335         kfree(unit);
336         return ERR_PTR(-EINVAL);
337 }
338
339 /**
340  * zfcp_unit_dequeue - dequeue unit
341  * @unit: pointer to zfcp_unit
342  *
343  * waits until all work is done on unit and removes it then from the unit->list
344  * of the associated port.
345  */
346 void zfcp_unit_dequeue(struct zfcp_unit *unit)
347 {
348         wait_event(unit->remove_wq, atomic_read(&unit->refcount) == 0);
349         write_lock_irq(&zfcp_data.config_lock);
350         list_del(&unit->list);
351         write_unlock_irq(&zfcp_data.config_lock);
352         zfcp_port_put(unit->port);
353         sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
354         device_unregister(&unit->sysfs_device);
355 }
356
357 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
358 {
359         /* must only be called with zfcp_data.config_sema taken */
360         adapter->pool.erp_req =
361                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
362         if (!adapter->pool.erp_req)
363                 return -ENOMEM;
364
365         adapter->pool.gid_pn_req =
366                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
367         if (!adapter->pool.gid_pn_req)
368                 return -ENOMEM;
369
370         adapter->pool.scsi_req =
371                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
372         if (!adapter->pool.scsi_req)
373                 return -ENOMEM;
374
375         adapter->pool.scsi_abort =
376                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
377         if (!adapter->pool.scsi_abort)
378                 return -ENOMEM;
379
380         adapter->pool.status_read_req =
381                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
382                                             sizeof(struct zfcp_fsf_req));
383         if (!adapter->pool.status_read_req)
384                 return -ENOMEM;
385
386         adapter->pool.qtcb_pool =
387                 mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
388         if (!adapter->pool.qtcb_pool)
389                 return -ENOMEM;
390
391         adapter->pool.status_read_data =
392                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
393                                          zfcp_data.sr_buffer_cache);
394         if (!adapter->pool.status_read_data)
395                 return -ENOMEM;
396
397         adapter->pool.gid_pn_data =
398                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
399         if (!adapter->pool.gid_pn_data)
400                 return -ENOMEM;
401
402         return 0;
403 }
404
405 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
406 {
407         /* zfcp_data.config_sema must be held */
408         if (adapter->pool.erp_req)
409                 mempool_destroy(adapter->pool.erp_req);
410         if (adapter->pool.scsi_req)
411                 mempool_destroy(adapter->pool.scsi_req);
412         if (adapter->pool.scsi_abort)
413                 mempool_destroy(adapter->pool.scsi_abort);
414         if (adapter->pool.qtcb_pool)
415                 mempool_destroy(adapter->pool.qtcb_pool);
416         if (adapter->pool.status_read_req)
417                 mempool_destroy(adapter->pool.status_read_req);
418         if (adapter->pool.status_read_data)
419                 mempool_destroy(adapter->pool.status_read_data);
420         if (adapter->pool.gid_pn_data)
421                 mempool_destroy(adapter->pool.gid_pn_data);
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->qdio)) {
437                         if (atomic_read(&adapter->stat_miss) >= 16) {
438                                 zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
439                                                         NULL);
440                                 return 1;
441                         }
442                         break;
443                 } else
444                         atomic_dec(&adapter->stat_miss);
445         return 0;
446 }
447
448 static void _zfcp_status_read_scheduler(struct work_struct *work)
449 {
450         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
451                                              stat_work));
452 }
453
454 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
455 {
456         struct zfcp_adapter *adapter =
457                 container_of(sl, struct zfcp_adapter, service_level);
458
459         seq_printf(m, "zfcp: %s microcode level %x\n",
460                    dev_name(&adapter->ccw_device->dev),
461                    adapter->fsf_lic_version);
462 }
463
464 static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
465 {
466         char name[TASK_COMM_LEN];
467
468         snprintf(name, sizeof(name), "zfcp_q_%s",
469                  dev_name(&adapter->ccw_device->dev));
470         adapter->work_queue = create_singlethread_workqueue(name);
471
472         if (adapter->work_queue)
473                 return 0;
474         return -ENOMEM;
475 }
476
477 static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
478 {
479         if (adapter->work_queue)
480                 destroy_workqueue(adapter->work_queue);
481         adapter->work_queue = NULL;
482
483 }
484
485 /**
486  * zfcp_adapter_enqueue - enqueue a new adapter to the list
487  * @ccw_device: pointer to the struct cc_device
488  *
489  * Returns:     0             if a new adapter was successfully enqueued
490  *              -ENOMEM       if alloc failed
491  * Enqueues an adapter at the end of the adapter list in the driver data.
492  * All adapter internal structures are set up.
493  * Proc-fs entries are also created.
494  * locks:       config_sema must be held to serialise changes to the adapter list
495  */
496 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
497 {
498         struct zfcp_adapter *adapter;
499
500         /*
501          * Note: It is safe to release the list_lock, as any list changes
502          * are protected by the config_sema, which must be held to get here
503          */
504
505         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
506         if (!adapter)
507                 return -ENOMEM;
508
509         adapter->gs = kzalloc(sizeof(struct zfcp_wka_ports), GFP_KERNEL);
510         if (!adapter->gs) {
511                 kfree(adapter);
512                 return -ENOMEM;
513         }
514
515         adapter->qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
516         if (!adapter->qdio)
517                 goto qdio_mem_failed;
518
519         adapter->qdio->adapter = adapter;
520
521         ccw_device->handler = NULL;
522         adapter->ccw_device = ccw_device;
523         atomic_set(&adapter->refcount, 0);
524
525         if (zfcp_qdio_allocate(adapter->qdio, ccw_device))
526                 goto qdio_allocate_failed;
527
528         if (zfcp_allocate_low_mem_buffers(adapter))
529                 goto failed_low_mem_buffers;
530
531         if (zfcp_reqlist_alloc(adapter))
532                 goto failed_low_mem_buffers;
533
534         if (zfcp_dbf_adapter_register(adapter))
535                 goto debug_register_failed;
536
537         if (zfcp_setup_adapter_work_queue(adapter))
538                 goto work_queue_failed;
539
540         init_waitqueue_head(&adapter->remove_wq);
541         init_waitqueue_head(&adapter->erp_thread_wqh);
542         init_waitqueue_head(&adapter->erp_done_wqh);
543
544         INIT_LIST_HEAD(&adapter->port_list_head);
545         INIT_LIST_HEAD(&adapter->erp_ready_head);
546         INIT_LIST_HEAD(&adapter->erp_running_head);
547
548         spin_lock_init(&adapter->req_list_lock);
549
550         spin_lock_init(&adapter->qdio->req_q_lock);
551         spin_lock_init(&adapter->qdio->stat_lock);
552
553         rwlock_init(&adapter->erp_lock);
554         rwlock_init(&adapter->abort_lock);
555
556         sema_init(&adapter->erp_ready_sem, 0);
557
558         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
559         INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);
560
561         adapter->service_level.seq_print = zfcp_print_sl;
562
563         /* mark adapter unusable as long as sysfs registration is not complete */
564         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
565
566         dev_set_drvdata(&ccw_device->dev, adapter);
567
568         if (sysfs_create_group(&ccw_device->dev.kobj,
569                                &zfcp_sysfs_adapter_attrs))
570                 goto sysfs_failed;
571
572         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
573         zfcp_fc_wka_ports_init(adapter);
574
575         if (!zfcp_adapter_scsi_register(adapter))
576                 return 0;
577
578 sysfs_failed:
579         zfcp_destroy_adapter_work_queue(adapter);
580 work_queue_failed:
581         zfcp_dbf_adapter_unregister(adapter->dbf);
582 debug_register_failed:
583         dev_set_drvdata(&ccw_device->dev, NULL);
584         kfree(adapter->req_list);
585 failed_low_mem_buffers:
586         zfcp_free_low_mem_buffers(adapter);
587 qdio_allocate_failed:
588         zfcp_qdio_free(adapter->qdio);
589         kfree(adapter->qdio);
590 qdio_mem_failed:
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->scan_work);
606         cancel_work_sync(&adapter->stat_work);
607         zfcp_fc_wka_ports_force_offline(adapter->gs);
608         zfcp_adapter_scsi_unregister(adapter);
609         sysfs_remove_group(&adapter->ccw_device->dev.kobj,
610                            &zfcp_sysfs_adapter_attrs);
611         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
612         /* sanity check: no pending FSF requests */
613         spin_lock_irqsave(&adapter->req_list_lock, flags);
614         retval = zfcp_reqlist_isempty(adapter);
615         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
616         if (!retval)
617                 return;
618
619         zfcp_destroy_adapter_work_queue(adapter);
620         zfcp_dbf_adapter_unregister(adapter->dbf);
621         zfcp_qdio_free(adapter->qdio);
622         zfcp_free_low_mem_buffers(adapter);
623         kfree(adapter->req_list);
624         kfree(adapter->fc_stats);
625         kfree(adapter->stats_reset_data);
626         kfree(adapter->gs);
627         kfree(adapter->qdio);
628         kfree(adapter);
629 }
630
631 static void zfcp_sysfs_port_release(struct device *dev)
632 {
633         kfree(container_of(dev, struct zfcp_port, sysfs_device));
634 }
635
636 /**
637  * zfcp_port_enqueue - enqueue port to port list of adapter
638  * @adapter: adapter where remote port is added
639  * @wwpn: WWPN of the remote port to be enqueued
640  * @status: initial status for the port
641  * @d_id: destination id of the remote port to be enqueued
642  * Returns: pointer to enqueued port on success, ERR_PTR on error
643  * Locks: config_sema must be held to serialize changes to the port list
644  *
645  * All port internal structures are set up and the sysfs entry is generated.
646  * d_id is used to enqueue ports with a well known address like the Directory
647  * Service for nameserver lookup.
648  */
649 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
650                                      u32 status, u32 d_id)
651 {
652         struct zfcp_port *port;
653         int retval;
654
655         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
656         if (!port)
657                 return ERR_PTR(-ENOMEM);
658
659         init_waitqueue_head(&port->remove_wq);
660         INIT_LIST_HEAD(&port->unit_list_head);
661         INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
662         INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
663         INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
664
665         port->adapter = adapter;
666         port->d_id = d_id;
667         port->wwpn = wwpn;
668         port->rport_task = RPORT_NONE;
669
670         /* mark port unusable as long as sysfs registration is not complete */
671         atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
672         atomic_set(&port->refcount, 0);
673
674         dev_set_name(&port->sysfs_device, "0x%016llx",
675                      (unsigned long long)wwpn);
676         port->sysfs_device.parent = &adapter->ccw_device->dev;
677
678         port->sysfs_device.release = zfcp_sysfs_port_release;
679         dev_set_drvdata(&port->sysfs_device, port);
680
681         read_lock_irq(&zfcp_data.config_lock);
682         if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
683                 read_unlock_irq(&zfcp_data.config_lock);
684                 goto err_out_free;
685         }
686         read_unlock_irq(&zfcp_data.config_lock);
687
688         if (device_register(&port->sysfs_device))
689                 goto err_out_free;
690
691         retval = sysfs_create_group(&port->sysfs_device.kobj,
692                                     &zfcp_sysfs_port_attrs);
693
694         if (retval) {
695                 device_unregister(&port->sysfs_device);
696                 goto err_out;
697         }
698
699         zfcp_port_get(port);
700
701         write_lock_irq(&zfcp_data.config_lock);
702         list_add_tail(&port->list, &adapter->port_list_head);
703         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
704         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
705
706         write_unlock_irq(&zfcp_data.config_lock);
707
708         zfcp_adapter_get(adapter);
709         return port;
710
711 err_out_free:
712         kfree(port);
713 err_out:
714         return ERR_PTR(-EINVAL);
715 }
716
717 /**
718  * zfcp_port_dequeue - dequeues a port from the port list of the adapter
719  * @port: pointer to struct zfcp_port which should be removed
720  */
721 void zfcp_port_dequeue(struct zfcp_port *port)
722 {
723         write_lock_irq(&zfcp_data.config_lock);
724         list_del(&port->list);
725         write_unlock_irq(&zfcp_data.config_lock);
726         if (port->rport) {
727                 port->rport->dd_data = NULL;
728                 port->rport = NULL;
729         }
730         wait_event(port->remove_wq, atomic_read(&port->refcount) == 0);
731         cancel_work_sync(&port->rport_work); /* usually not necessary */
732         zfcp_adapter_put(port->adapter);
733         sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
734         device_unregister(&port->sysfs_device);
735 }
736
737 /**
738  * zfcp_sg_free_table - free memory used by scatterlists
739  * @sg: pointer to scatterlist
740  * @count: number of scatterlist which are to be free'ed
741  * the scatterlist are expected to reference pages always
742  */
743 void zfcp_sg_free_table(struct scatterlist *sg, int count)
744 {
745         int i;
746
747         for (i = 0; i < count; i++, sg++)
748                 if (sg)
749                         free_page((unsigned long) sg_virt(sg));
750                 else
751                         break;
752 }
753
754 /**
755  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
756  * @sg: pointer to struct scatterlist
757  * @count: number of scatterlists which should be assigned with buffers
758  * of size page
759  *
760  * Returns: 0 on success, -ENOMEM otherwise
761  */
762 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
763 {
764         void *addr;
765         int i;
766
767         sg_init_table(sg, count);
768         for (i = 0; i < count; i++, sg++) {
769                 addr = (void *) get_zeroed_page(GFP_KERNEL);
770                 if (!addr) {
771                         zfcp_sg_free_table(sg, i);
772                         return -ENOMEM;
773                 }
774                 sg_set_buf(sg, addr, PAGE_SIZE);
775         }
776         return 0;
777 }