xref: /openbmc/linux/drivers/s390/scsi/zfcp_fc.c (revision 78c99ba1)
1 /*
2  * zfcp device driver
3  *
4  * Fibre Channel related functions for the zfcp device driver.
5  *
6  * Copyright IBM Corporation 2008, 2009
7  */
8 
9 #define KMSG_COMPONENT "zfcp"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11 
12 #include "zfcp_ext.h"
13 
14 enum rscn_address_format {
15 	RSCN_PORT_ADDRESS	= 0x0,
16 	RSCN_AREA_ADDRESS	= 0x1,
17 	RSCN_DOMAIN_ADDRESS	= 0x2,
18 	RSCN_FABRIC_ADDRESS	= 0x3,
19 };
20 
21 static u32 rscn_range_mask[] = {
22 	[RSCN_PORT_ADDRESS]		= 0xFFFFFF,
23 	[RSCN_AREA_ADDRESS]		= 0xFFFF00,
24 	[RSCN_DOMAIN_ADDRESS]		= 0xFF0000,
25 	[RSCN_FABRIC_ADDRESS]		= 0x000000,
26 };
27 
28 struct ct_iu_gpn_ft_req {
29 	struct ct_hdr header;
30 	u8 flags;
31 	u8 domain_id_scope;
32 	u8 area_id_scope;
33 	u8 fc4_type;
34 } __attribute__ ((packed));
35 
36 struct gpn_ft_resp_acc {
37 	u8 control;
38 	u8 port_id[3];
39 	u8 reserved[4];
40 	u64 wwpn;
41 } __attribute__ ((packed));
42 
43 #define ZFCP_CT_SIZE_ONE_PAGE	(PAGE_SIZE - sizeof(struct ct_hdr))
44 #define ZFCP_GPN_FT_ENTRIES	(ZFCP_CT_SIZE_ONE_PAGE \
45 					/ sizeof(struct gpn_ft_resp_acc))
46 #define ZFCP_GPN_FT_BUFFERS 4
47 #define ZFCP_GPN_FT_MAX_SIZE (ZFCP_GPN_FT_BUFFERS * PAGE_SIZE \
48 				- sizeof(struct ct_hdr))
49 #define ZFCP_GPN_FT_MAX_ENTRIES ZFCP_GPN_FT_BUFFERS * (ZFCP_GPN_FT_ENTRIES + 1)
50 
51 struct ct_iu_gpn_ft_resp {
52 	struct ct_hdr header;
53 	struct gpn_ft_resp_acc accept[ZFCP_GPN_FT_ENTRIES];
54 } __attribute__ ((packed));
55 
56 struct zfcp_gpn_ft {
57 	struct zfcp_send_ct ct;
58 	struct scatterlist sg_req;
59 	struct scatterlist sg_resp[ZFCP_GPN_FT_BUFFERS];
60 };
61 
62 struct zfcp_fc_ns_handler_data {
63 	struct completion done;
64 	void (*handler)(unsigned long);
65 	unsigned long handler_data;
66 };
67 
68 static int zfcp_wka_port_get(struct zfcp_wka_port *wka_port)
69 {
70 	if (mutex_lock_interruptible(&wka_port->mutex))
71 		return -ERESTARTSYS;
72 
73 	if (wka_port->status == ZFCP_WKA_PORT_OFFLINE ||
74 	    wka_port->status == ZFCP_WKA_PORT_CLOSING) {
75 		wka_port->status = ZFCP_WKA_PORT_OPENING;
76 		if (zfcp_fsf_open_wka_port(wka_port))
77 			wka_port->status = ZFCP_WKA_PORT_OFFLINE;
78 	}
79 
80 	mutex_unlock(&wka_port->mutex);
81 
82 	wait_event_timeout(
83 		wka_port->completion_wq,
84 		wka_port->status == ZFCP_WKA_PORT_ONLINE ||
85 		wka_port->status == ZFCP_WKA_PORT_OFFLINE,
86 		HZ >> 1);
87 
88 	if (wka_port->status == ZFCP_WKA_PORT_ONLINE) {
89 		atomic_inc(&wka_port->refcount);
90 		return 0;
91 	}
92 	return -EIO;
93 }
94 
95 static void zfcp_wka_port_offline(struct work_struct *work)
96 {
97 	struct delayed_work *dw = to_delayed_work(work);
98 	struct zfcp_wka_port *wka_port =
99 			container_of(dw, struct zfcp_wka_port, work);
100 
101 	mutex_lock(&wka_port->mutex);
102 	if ((atomic_read(&wka_port->refcount) != 0) ||
103 	    (wka_port->status != ZFCP_WKA_PORT_ONLINE))
104 		goto out;
105 
106 	wka_port->status = ZFCP_WKA_PORT_CLOSING;
107 	if (zfcp_fsf_close_wka_port(wka_port)) {
108 		wka_port->status = ZFCP_WKA_PORT_OFFLINE;
109 		wake_up(&wka_port->completion_wq);
110 	}
111 out:
112 	mutex_unlock(&wka_port->mutex);
113 }
114 
115 static void zfcp_wka_port_put(struct zfcp_wka_port *wka_port)
116 {
117 	if (atomic_dec_return(&wka_port->refcount) != 0)
118 		return;
119 	/* wait 10 miliseconds, other reqs might pop in */
120 	schedule_delayed_work(&wka_port->work, HZ / 100);
121 }
122 
123 void zfcp_fc_nameserver_init(struct zfcp_adapter *adapter)
124 {
125 	struct zfcp_wka_port *wka_port = &adapter->nsp;
126 
127 	init_waitqueue_head(&wka_port->completion_wq);
128 
129 	wka_port->adapter = adapter;
130 	wka_port->d_id = ZFCP_DID_DIRECTORY_SERVICE;
131 
132 	wka_port->status = ZFCP_WKA_PORT_OFFLINE;
133 	atomic_set(&wka_port->refcount, 0);
134 	mutex_init(&wka_port->mutex);
135 	INIT_DELAYED_WORK(&wka_port->work, zfcp_wka_port_offline);
136 }
137 
138 void zfcp_fc_wka_port_force_offline(struct zfcp_wka_port *wka)
139 {
140 	cancel_delayed_work_sync(&wka->work);
141 	mutex_lock(&wka->mutex);
142 	wka->status = ZFCP_WKA_PORT_OFFLINE;
143 	mutex_unlock(&wka->mutex);
144 }
145 
146 static void _zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req, u32 range,
147 				   struct fcp_rscn_element *elem)
148 {
149 	unsigned long flags;
150 	struct zfcp_port *port;
151 
152 	read_lock_irqsave(&zfcp_data.config_lock, flags);
153 	list_for_each_entry(port, &fsf_req->adapter->port_list_head, list)
154 		if ((port->d_id & range) == (elem->nport_did & range))
155 			zfcp_test_link(port);
156 
157 	read_unlock_irqrestore(&zfcp_data.config_lock, flags);
158 }
159 
160 static void zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req)
161 {
162 	struct fsf_status_read_buffer *status_buffer = (void *)fsf_req->data;
163 	struct fcp_rscn_head *fcp_rscn_head;
164 	struct fcp_rscn_element *fcp_rscn_element;
165 	u16 i;
166 	u16 no_entries;
167 	u32 range_mask;
168 
169 	fcp_rscn_head = (struct fcp_rscn_head *) status_buffer->payload.data;
170 	fcp_rscn_element = (struct fcp_rscn_element *) fcp_rscn_head;
171 
172 	/* see FC-FS */
173 	no_entries = fcp_rscn_head->payload_len /
174 			sizeof(struct fcp_rscn_element);
175 
176 	for (i = 1; i < no_entries; i++) {
177 		/* skip head and start with 1st element */
178 		fcp_rscn_element++;
179 		range_mask = rscn_range_mask[fcp_rscn_element->addr_format];
180 		_zfcp_fc_incoming_rscn(fsf_req, range_mask, fcp_rscn_element);
181 	}
182 	schedule_work(&fsf_req->adapter->scan_work);
183 }
184 
185 static void zfcp_fc_incoming_wwpn(struct zfcp_fsf_req *req, u64 wwpn)
186 {
187 	struct zfcp_adapter *adapter = req->adapter;
188 	struct zfcp_port *port;
189 	unsigned long flags;
190 
191 	read_lock_irqsave(&zfcp_data.config_lock, flags);
192 	list_for_each_entry(port, &adapter->port_list_head, list)
193 		if (port->wwpn == wwpn)
194 			break;
195 	read_unlock_irqrestore(&zfcp_data.config_lock, flags);
196 
197 	if (port && (port->wwpn == wwpn))
198 		zfcp_erp_port_forced_reopen(port, 0, "fciwwp1", req);
199 }
200 
201 static void zfcp_fc_incoming_plogi(struct zfcp_fsf_req *req)
202 {
203 	struct fsf_status_read_buffer *status_buffer =
204 		(struct fsf_status_read_buffer *)req->data;
205 	struct fsf_plogi *els_plogi =
206 		(struct fsf_plogi *) status_buffer->payload.data;
207 
208 	zfcp_fc_incoming_wwpn(req, els_plogi->serv_param.wwpn);
209 }
210 
211 static void zfcp_fc_incoming_logo(struct zfcp_fsf_req *req)
212 {
213 	struct fsf_status_read_buffer *status_buffer =
214 		(struct fsf_status_read_buffer *)req->data;
215 	struct fcp_logo *els_logo =
216 		(struct fcp_logo *) status_buffer->payload.data;
217 
218 	zfcp_fc_incoming_wwpn(req, els_logo->nport_wwpn);
219 }
220 
221 /**
222  * zfcp_fc_incoming_els - handle incoming ELS
223  * @fsf_req - request which contains incoming ELS
224  */
225 void zfcp_fc_incoming_els(struct zfcp_fsf_req *fsf_req)
226 {
227 	struct fsf_status_read_buffer *status_buffer =
228 		(struct fsf_status_read_buffer *) fsf_req->data;
229 	unsigned int els_type = status_buffer->payload.data[0];
230 
231 	zfcp_san_dbf_event_incoming_els(fsf_req);
232 	if (els_type == LS_PLOGI)
233 		zfcp_fc_incoming_plogi(fsf_req);
234 	else if (els_type == LS_LOGO)
235 		zfcp_fc_incoming_logo(fsf_req);
236 	else if (els_type == LS_RSCN)
237 		zfcp_fc_incoming_rscn(fsf_req);
238 }
239 
240 static void zfcp_fc_ns_handler(unsigned long data)
241 {
242 	struct zfcp_fc_ns_handler_data *compl_rec =
243 			(struct zfcp_fc_ns_handler_data *) data;
244 
245 	if (compl_rec->handler)
246 		compl_rec->handler(compl_rec->handler_data);
247 
248 	complete(&compl_rec->done);
249 }
250 
251 static void zfcp_fc_ns_gid_pn_eval(unsigned long data)
252 {
253 	struct zfcp_gid_pn_data *gid_pn = (struct zfcp_gid_pn_data *) data;
254 	struct zfcp_send_ct *ct = &gid_pn->ct;
255 	struct ct_iu_gid_pn_req *ct_iu_req = sg_virt(ct->req);
256 	struct ct_iu_gid_pn_resp *ct_iu_resp = sg_virt(ct->resp);
257 	struct zfcp_port *port = gid_pn->port;
258 
259 	if (ct->status)
260 		return;
261 	if (ct_iu_resp->header.cmd_rsp_code != ZFCP_CT_ACCEPT)
262 		return;
263 
264 	/* paranoia */
265 	if (ct_iu_req->wwpn != port->wwpn)
266 		return;
267 	/* looks like a valid d_id */
268 	port->d_id = ct_iu_resp->d_id & ZFCP_DID_MASK;
269 }
270 
271 int static zfcp_fc_ns_gid_pn_request(struct zfcp_erp_action *erp_action,
272 				     struct zfcp_gid_pn_data *gid_pn)
273 {
274 	struct zfcp_adapter *adapter = erp_action->adapter;
275 	struct zfcp_fc_ns_handler_data compl_rec;
276 	int ret;
277 
278 	/* setup parameters for send generic command */
279 	gid_pn->port = erp_action->port;
280 	gid_pn->ct.wka_port = &adapter->nsp;
281 	gid_pn->ct.handler = zfcp_fc_ns_handler;
282 	gid_pn->ct.handler_data = (unsigned long) &compl_rec;
283 	gid_pn->ct.timeout = ZFCP_NS_GID_PN_TIMEOUT;
284 	gid_pn->ct.req = &gid_pn->req;
285 	gid_pn->ct.resp = &gid_pn->resp;
286 	sg_init_one(&gid_pn->req, &gid_pn->ct_iu_req,
287 		    sizeof(struct ct_iu_gid_pn_req));
288 	sg_init_one(&gid_pn->resp, &gid_pn->ct_iu_resp,
289 		    sizeof(struct ct_iu_gid_pn_resp));
290 
291 	/* setup nameserver request */
292 	gid_pn->ct_iu_req.header.revision = ZFCP_CT_REVISION;
293 	gid_pn->ct_iu_req.header.gs_type = ZFCP_CT_DIRECTORY_SERVICE;
294 	gid_pn->ct_iu_req.header.gs_subtype = ZFCP_CT_NAME_SERVER;
295 	gid_pn->ct_iu_req.header.options = ZFCP_CT_SYNCHRONOUS;
296 	gid_pn->ct_iu_req.header.cmd_rsp_code = ZFCP_CT_GID_PN;
297 	gid_pn->ct_iu_req.header.max_res_size = ZFCP_CT_SIZE_ONE_PAGE / 4;
298 	gid_pn->ct_iu_req.wwpn = erp_action->port->wwpn;
299 
300 	init_completion(&compl_rec.done);
301 	compl_rec.handler = zfcp_fc_ns_gid_pn_eval;
302 	compl_rec.handler_data = (unsigned long) gid_pn;
303 	ret = zfcp_fsf_send_ct(&gid_pn->ct, adapter->pool.fsf_req_erp,
304 			       erp_action);
305 	if (!ret)
306 		wait_for_completion(&compl_rec.done);
307 	return ret;
308 }
309 
310 /**
311  * zfcp_fc_ns_gid_pn_request - initiate GID_PN nameserver request
312  * @erp_action: pointer to zfcp_erp_action where GID_PN request is needed
313  * return: -ENOMEM on error, 0 otherwise
314  */
315 int zfcp_fc_ns_gid_pn(struct zfcp_erp_action *erp_action)
316 {
317 	int ret;
318 	struct zfcp_gid_pn_data *gid_pn;
319 	struct zfcp_adapter *adapter = erp_action->adapter;
320 
321 	gid_pn = mempool_alloc(adapter->pool.data_gid_pn, GFP_ATOMIC);
322 	if (!gid_pn)
323 		return -ENOMEM;
324 
325 	memset(gid_pn, 0, sizeof(*gid_pn));
326 
327 	ret = zfcp_wka_port_get(&adapter->nsp);
328 	if (ret)
329 		goto out;
330 
331 	ret = zfcp_fc_ns_gid_pn_request(erp_action, gid_pn);
332 
333 	zfcp_wka_port_put(&adapter->nsp);
334 out:
335 	mempool_free(gid_pn, adapter->pool.data_gid_pn);
336 	return ret;
337 }
338 
339 /**
340  * zfcp_fc_plogi_evaluate - evaluate PLOGI playload
341  * @port: zfcp_port structure
342  * @plogi: plogi payload
343  *
344  * Evaluate PLOGI playload and copy important fields into zfcp_port structure
345  */
346 void zfcp_fc_plogi_evaluate(struct zfcp_port *port, struct fsf_plogi *plogi)
347 {
348 	port->maxframe_size = plogi->serv_param.common_serv_param[7] |
349 		((plogi->serv_param.common_serv_param[6] & 0x0F) << 8);
350 	if (plogi->serv_param.class1_serv_param[0] & 0x80)
351 		port->supported_classes |= FC_COS_CLASS1;
352 	if (plogi->serv_param.class2_serv_param[0] & 0x80)
353 		port->supported_classes |= FC_COS_CLASS2;
354 	if (plogi->serv_param.class3_serv_param[0] & 0x80)
355 		port->supported_classes |= FC_COS_CLASS3;
356 	if (plogi->serv_param.class4_serv_param[0] & 0x80)
357 		port->supported_classes |= FC_COS_CLASS4;
358 }
359 
360 struct zfcp_els_adisc {
361 	struct zfcp_send_els els;
362 	struct scatterlist req;
363 	struct scatterlist resp;
364 	struct zfcp_ls_adisc ls_adisc;
365 	struct zfcp_ls_adisc ls_adisc_acc;
366 };
367 
368 static void zfcp_fc_adisc_handler(unsigned long data)
369 {
370 	struct zfcp_els_adisc *adisc = (struct zfcp_els_adisc *) data;
371 	struct zfcp_port *port = adisc->els.port;
372 	struct zfcp_ls_adisc *ls_adisc = &adisc->ls_adisc_acc;
373 
374 	if (adisc->els.status) {
375 		/* request rejected or timed out */
376 		zfcp_erp_port_forced_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED,
377 					    "fcadh_1", NULL);
378 		goto out;
379 	}
380 
381 	if (!port->wwnn)
382 		port->wwnn = ls_adisc->wwnn;
383 
384 	if ((port->wwpn != ls_adisc->wwpn) ||
385 	    !(atomic_read(&port->status) & ZFCP_STATUS_COMMON_OPEN)) {
386 		zfcp_erp_port_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED,
387 				     "fcadh_2", NULL);
388 		goto out;
389 	}
390 
391 	/* port is good, unblock rport without going through erp */
392 	zfcp_scsi_schedule_rport_register(port);
393  out:
394 	zfcp_port_put(port);
395 	kfree(adisc);
396 }
397 
398 static int zfcp_fc_adisc(struct zfcp_port *port)
399 {
400 	struct zfcp_els_adisc *adisc;
401 	struct zfcp_adapter *adapter = port->adapter;
402 
403 	adisc = kzalloc(sizeof(struct zfcp_els_adisc), GFP_ATOMIC);
404 	if (!adisc)
405 		return -ENOMEM;
406 
407 	adisc->els.req = &adisc->req;
408 	adisc->els.resp = &adisc->resp;
409 	sg_init_one(adisc->els.req, &adisc->ls_adisc,
410 		    sizeof(struct zfcp_ls_adisc));
411 	sg_init_one(adisc->els.resp, &adisc->ls_adisc_acc,
412 		    sizeof(struct zfcp_ls_adisc));
413 
414 	adisc->els.adapter = adapter;
415 	adisc->els.port = port;
416 	adisc->els.d_id = port->d_id;
417 	adisc->els.handler = zfcp_fc_adisc_handler;
418 	adisc->els.handler_data = (unsigned long) adisc;
419 	adisc->els.ls_code = adisc->ls_adisc.code = ZFCP_LS_ADISC;
420 
421 	/* acc. to FC-FS, hard_nport_id in ADISC should not be set for ports
422 	   without FC-AL-2 capability, so we don't set it */
423 	adisc->ls_adisc.wwpn = fc_host_port_name(adapter->scsi_host);
424 	adisc->ls_adisc.wwnn = fc_host_node_name(adapter->scsi_host);
425 	adisc->ls_adisc.nport_id = fc_host_port_id(adapter->scsi_host);
426 
427 	return zfcp_fsf_send_els(&adisc->els);
428 }
429 
430 void zfcp_fc_link_test_work(struct work_struct *work)
431 {
432 	struct zfcp_port *port =
433 		container_of(work, struct zfcp_port, test_link_work);
434 	int retval;
435 
436 	zfcp_port_get(port);
437 	port->rport_task = RPORT_DEL;
438 	zfcp_scsi_rport_work(&port->rport_work);
439 
440 	retval = zfcp_fc_adisc(port);
441 	if (retval == 0)
442 		return;
443 
444 	/* send of ADISC was not possible */
445 	zfcp_erp_port_forced_reopen(port, 0, "fcltwk1", NULL);
446 
447 	zfcp_port_put(port);
448 }
449 
450 /**
451  * zfcp_test_link - lightweight link test procedure
452  * @port: port to be tested
453  *
454  * Test status of a link to a remote port using the ELS command ADISC.
455  * If there is a problem with the remote port, error recovery steps
456  * will be triggered.
457  */
458 void zfcp_test_link(struct zfcp_port *port)
459 {
460 	zfcp_port_get(port);
461 	if (!queue_work(zfcp_data.work_queue, &port->test_link_work))
462 		zfcp_port_put(port);
463 }
464 
465 static void zfcp_free_sg_env(struct zfcp_gpn_ft *gpn_ft, int buf_num)
466 {
467 	struct scatterlist *sg = &gpn_ft->sg_req;
468 
469 	kfree(sg_virt(sg)); /* free request buffer */
470 	zfcp_sg_free_table(gpn_ft->sg_resp, buf_num);
471 
472 	kfree(gpn_ft);
473 }
474 
475 static struct zfcp_gpn_ft *zfcp_alloc_sg_env(int buf_num)
476 {
477 	struct zfcp_gpn_ft *gpn_ft;
478 	struct ct_iu_gpn_ft_req *req;
479 
480 	gpn_ft = kzalloc(sizeof(*gpn_ft), GFP_KERNEL);
481 	if (!gpn_ft)
482 		return NULL;
483 
484 	req = kzalloc(sizeof(struct ct_iu_gpn_ft_req), GFP_KERNEL);
485 	if (!req) {
486 		kfree(gpn_ft);
487 		gpn_ft = NULL;
488 		goto out;
489 	}
490 	sg_init_one(&gpn_ft->sg_req, req, sizeof(*req));
491 
492 	if (zfcp_sg_setup_table(gpn_ft->sg_resp, buf_num)) {
493 		zfcp_free_sg_env(gpn_ft, buf_num);
494 		gpn_ft = NULL;
495 	}
496 out:
497 	return gpn_ft;
498 }
499 
500 
501 static int zfcp_scan_issue_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
502 				  struct zfcp_adapter *adapter,
503 				  int max_bytes)
504 {
505 	struct zfcp_send_ct *ct = &gpn_ft->ct;
506 	struct ct_iu_gpn_ft_req *req = sg_virt(&gpn_ft->sg_req);
507 	struct zfcp_fc_ns_handler_data compl_rec;
508 	int ret;
509 
510 	/* prepare CT IU for GPN_FT */
511 	req->header.revision = ZFCP_CT_REVISION;
512 	req->header.gs_type = ZFCP_CT_DIRECTORY_SERVICE;
513 	req->header.gs_subtype = ZFCP_CT_NAME_SERVER;
514 	req->header.options = ZFCP_CT_SYNCHRONOUS;
515 	req->header.cmd_rsp_code = ZFCP_CT_GPN_FT;
516 	req->header.max_res_size = max_bytes / 4;
517 	req->flags = 0;
518 	req->domain_id_scope = 0;
519 	req->area_id_scope = 0;
520 	req->fc4_type = ZFCP_CT_SCSI_FCP;
521 
522 	/* prepare zfcp_send_ct */
523 	ct->wka_port = &adapter->nsp;
524 	ct->handler = zfcp_fc_ns_handler;
525 	ct->handler_data = (unsigned long)&compl_rec;
526 	ct->timeout = 10;
527 	ct->req = &gpn_ft->sg_req;
528 	ct->resp = gpn_ft->sg_resp;
529 
530 	init_completion(&compl_rec.done);
531 	compl_rec.handler = NULL;
532 	ret = zfcp_fsf_send_ct(ct, NULL, NULL);
533 	if (!ret)
534 		wait_for_completion(&compl_rec.done);
535 	return ret;
536 }
537 
538 static void zfcp_validate_port(struct zfcp_port *port)
539 {
540 	struct zfcp_adapter *adapter = port->adapter;
541 
542 	if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC))
543 		return;
544 
545 	atomic_clear_mask(ZFCP_STATUS_COMMON_NOESC, &port->status);
546 
547 	if ((port->supported_classes != 0) ||
548 	    !list_empty(&port->unit_list_head)) {
549 		zfcp_port_put(port);
550 		return;
551 	}
552 	zfcp_erp_port_shutdown(port, 0, "fcpval1", NULL);
553 	zfcp_erp_wait(adapter);
554 	zfcp_port_put(port);
555 	zfcp_port_dequeue(port);
556 }
557 
558 static int zfcp_scan_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
559 {
560 	struct zfcp_send_ct *ct = &gpn_ft->ct;
561 	struct scatterlist *sg = gpn_ft->sg_resp;
562 	struct ct_hdr *hdr = sg_virt(sg);
563 	struct gpn_ft_resp_acc *acc = sg_virt(sg);
564 	struct zfcp_adapter *adapter = ct->wka_port->adapter;
565 	struct zfcp_port *port, *tmp;
566 	u32 d_id;
567 	int ret = 0, x, last = 0;
568 
569 	if (ct->status)
570 		return -EIO;
571 
572 	if (hdr->cmd_rsp_code != ZFCP_CT_ACCEPT) {
573 		if (hdr->reason_code == ZFCP_CT_UNABLE_TO_PERFORM_CMD)
574 			return -EAGAIN; /* might be a temporary condition */
575 		return -EIO;
576 	}
577 
578 	if (hdr->max_res_size) {
579 		dev_warn(&adapter->ccw_device->dev,
580 			 "The name server reported %d words residual data\n",
581 			 hdr->max_res_size);
582 		return -E2BIG;
583 	}
584 
585 	down(&zfcp_data.config_sema);
586 
587 	/* first entry is the header */
588 	for (x = 1; x < max_entries && !last; x++) {
589 		if (x % (ZFCP_GPN_FT_ENTRIES + 1))
590 			acc++;
591 		else
592 			acc = sg_virt(++sg);
593 
594 		last = acc->control & 0x80;
595 		d_id = acc->port_id[0] << 16 | acc->port_id[1] << 8 |
596 		       acc->port_id[2];
597 
598 		/* don't attach ports with a well known address */
599 		if ((d_id & ZFCP_DID_WKA) == ZFCP_DID_WKA)
600 			continue;
601 		/* skip the adapter's port and known remote ports */
602 		if (acc->wwpn == fc_host_port_name(adapter->scsi_host))
603 			continue;
604 		port = zfcp_get_port_by_wwpn(adapter, acc->wwpn);
605 		if (port)
606 			continue;
607 
608 		port = zfcp_port_enqueue(adapter, acc->wwpn,
609 					 ZFCP_STATUS_COMMON_NOESC, d_id);
610 		if (IS_ERR(port))
611 			ret = PTR_ERR(port);
612 		else
613 			zfcp_erp_port_reopen(port, 0, "fcegpf1", NULL);
614 	}
615 
616 	zfcp_erp_wait(adapter);
617 	list_for_each_entry_safe(port, tmp, &adapter->port_list_head, list)
618 		zfcp_validate_port(port);
619 	up(&zfcp_data.config_sema);
620 	return ret;
621 }
622 
623 /**
624  * zfcp_scan_ports - scan remote ports and attach new ports
625  * @adapter: pointer to struct zfcp_adapter
626  */
627 int zfcp_scan_ports(struct zfcp_adapter *adapter)
628 {
629 	int ret, i;
630 	struct zfcp_gpn_ft *gpn_ft;
631 	int chain, max_entries, buf_num, max_bytes;
632 
633 	chain = adapter->adapter_features & FSF_FEATURE_ELS_CT_CHAINED_SBALS;
634 	buf_num = chain ? ZFCP_GPN_FT_BUFFERS : 1;
635 	max_entries = chain ? ZFCP_GPN_FT_MAX_ENTRIES : ZFCP_GPN_FT_ENTRIES;
636 	max_bytes = chain ? ZFCP_GPN_FT_MAX_SIZE : ZFCP_CT_SIZE_ONE_PAGE;
637 
638 	if (fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPORT &&
639 	    fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPIV)
640 		return 0;
641 
642 	ret = zfcp_wka_port_get(&adapter->nsp);
643 	if (ret)
644 		return ret;
645 
646 	gpn_ft = zfcp_alloc_sg_env(buf_num);
647 	if (!gpn_ft) {
648 		ret = -ENOMEM;
649 		goto out;
650 	}
651 
652 	for (i = 0; i < 3; i++) {
653 		ret = zfcp_scan_issue_gpn_ft(gpn_ft, adapter, max_bytes);
654 		if (!ret) {
655 			ret = zfcp_scan_eval_gpn_ft(gpn_ft, max_entries);
656 			if (ret == -EAGAIN)
657 				ssleep(1);
658 			else
659 				break;
660 		}
661 	}
662 	zfcp_free_sg_env(gpn_ft, buf_num);
663 out:
664 	zfcp_wka_port_put(&adapter->nsp);
665 	return ret;
666 }
667 
668 
669 void _zfcp_scan_ports_later(struct work_struct *work)
670 {
671 	zfcp_scan_ports(container_of(work, struct zfcp_adapter, scan_work));
672 }
673