xref: /openbmc/linux/drivers/s390/scsi/zfcp_aux.c (revision 545e4006)
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 }
802