xref: /linux/drivers/s390/scsi/zfcp_dbf.c (revision 409c38d4f156740bf3165fd6ceae4fa6425eebf4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * zfcp device driver
4  *
5  * Debug traces for zfcp.
6  *
7  * Copyright IBM Corp. 2002, 2023
8  */
9 
10 #define KMSG_COMPONENT "zfcp"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/module.h>
14 #include <linux/ctype.h>
15 #include <linux/slab.h>
16 #include <asm/debug.h>
17 #include "zfcp_dbf.h"
18 #include "zfcp_ext.h"
19 #include "zfcp_fc.h"
20 
21 static u32 dbfsize = 4;
22 
23 module_param(dbfsize, uint, 0400);
24 MODULE_PARM_DESC(dbfsize,
25 		 "number of pages for each debug feature area (default 4)");
26 
27 static u32 dbflevel = 3;
28 
29 module_param(dbflevel, uint, 0400);
30 MODULE_PARM_DESC(dbflevel,
31 		 "log level for each debug feature area "
32 		 "(default 3, range 0..6)");
33 
34 static inline unsigned int zfcp_dbf_plen(unsigned int offset)
35 {
36 	return sizeof(struct zfcp_dbf_pay) + offset - ZFCP_DBF_PAY_MAX_REC;
37 }
38 
39 static inline
40 void zfcp_dbf_pl_write(struct zfcp_dbf *dbf, void *data, u16 length, char *area,
41 		       u64 req_id)
42 {
43 	struct zfcp_dbf_pay *pl = &dbf->pay_buf;
44 	u16 offset = 0, rec_length;
45 
46 	spin_lock(&dbf->pay_lock);
47 	memset(pl, 0, sizeof(*pl));
48 	pl->fsf_req_id = req_id;
49 	memcpy(pl->area, area, ZFCP_DBF_TAG_LEN);
50 
51 	while (offset < length) {
52 		rec_length = min((u16) ZFCP_DBF_PAY_MAX_REC,
53 				 (u16) (length - offset));
54 		memcpy(pl->data, data + offset, rec_length);
55 		debug_event(dbf->pay, 1, pl, zfcp_dbf_plen(rec_length));
56 
57 		offset += rec_length;
58 		pl->counter++;
59 	}
60 
61 	spin_unlock(&dbf->pay_lock);
62 }
63 
64 /**
65  * zfcp_dbf_hba_fsf_res - trace event for fsf responses
66  * @tag: tag indicating which kind of FSF response has been received
67  * @level: trace level to be used for event
68  * @req: request for which a response was received
69  */
70 void zfcp_dbf_hba_fsf_res(char *tag, int level, struct zfcp_fsf_req *req)
71 {
72 	struct zfcp_dbf *dbf = req->adapter->dbf;
73 	struct fsf_qtcb_prefix *q_pref = &req->qtcb->prefix;
74 	struct fsf_qtcb_header *q_head = &req->qtcb->header;
75 	struct zfcp_dbf_hba *rec = &dbf->hba_buf;
76 	unsigned long flags;
77 
78 	spin_lock_irqsave(&dbf->hba_lock, flags);
79 	memset(rec, 0, sizeof(*rec));
80 
81 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
82 	rec->id = ZFCP_DBF_HBA_RES;
83 	rec->fsf_req_id = req->req_id;
84 	rec->fsf_req_status = req->status;
85 	rec->fsf_cmd = q_head->fsf_command;
86 	rec->fsf_seq_no = q_pref->req_seq_no;
87 	rec->u.res.req_issued = req->issued;
88 	rec->u.res.prot_status = q_pref->prot_status;
89 	rec->u.res.fsf_status = q_head->fsf_status;
90 	rec->u.res.port_handle = q_head->port_handle;
91 	rec->u.res.lun_handle = q_head->lun_handle;
92 
93 	memcpy(rec->u.res.prot_status_qual, &q_pref->prot_status_qual,
94 	       FSF_PROT_STATUS_QUAL_SIZE);
95 	memcpy(rec->u.res.fsf_status_qual, &q_head->fsf_status_qual,
96 	       FSF_STATUS_QUALIFIER_SIZE);
97 
98 	rec->pl_len = q_head->log_length;
99 	zfcp_dbf_pl_write(dbf, (char *)q_pref + q_head->log_start,
100 			  rec->pl_len, "fsf_res", req->req_id);
101 
102 	debug_event(dbf->hba, level, rec, sizeof(*rec));
103 	spin_unlock_irqrestore(&dbf->hba_lock, flags);
104 }
105 
106 /**
107  * zfcp_dbf_hba_fsf_fces - trace event for fsf responses related to
108  *			   FC Endpoint Security (FCES)
109  * @tag: tag indicating which kind of FC Endpoint Security event has occurred
110  * @req: request for which a response was received
111  * @wwpn: remote port or ZFCP_DBF_INVALID_WWPN
112  * @fc_security_old: old FC Endpoint Security of FCP device or connection
113  * @fc_security_new: new FC Endpoint Security of FCP device or connection
114  */
115 void zfcp_dbf_hba_fsf_fces(char *tag, const struct zfcp_fsf_req *req, u64 wwpn,
116 			   u32 fc_security_old, u32 fc_security_new)
117 {
118 	struct zfcp_dbf *dbf = req->adapter->dbf;
119 	struct fsf_qtcb_prefix *q_pref = &req->qtcb->prefix;
120 	struct fsf_qtcb_header *q_head = &req->qtcb->header;
121 	struct zfcp_dbf_hba *rec = &dbf->hba_buf;
122 	static int const level = 3;
123 	unsigned long flags;
124 
125 	if (unlikely(!debug_level_enabled(dbf->hba, level)))
126 		return;
127 
128 	spin_lock_irqsave(&dbf->hba_lock, flags);
129 	memset(rec, 0, sizeof(*rec));
130 
131 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
132 	rec->id = ZFCP_DBF_HBA_FCES;
133 	rec->fsf_req_id = req->req_id;
134 	rec->fsf_req_status = req->status;
135 	rec->fsf_cmd = q_head->fsf_command;
136 	rec->fsf_seq_no = q_pref->req_seq_no;
137 	rec->u.fces.req_issued = req->issued;
138 	rec->u.fces.fsf_status = q_head->fsf_status;
139 	rec->u.fces.port_handle = q_head->port_handle;
140 	rec->u.fces.wwpn = wwpn;
141 	rec->u.fces.fc_security_old = fc_security_old;
142 	rec->u.fces.fc_security_new = fc_security_new;
143 
144 	debug_event(dbf->hba, level, rec, sizeof(*rec));
145 	spin_unlock_irqrestore(&dbf->hba_lock, flags);
146 }
147 
148 /**
149  * zfcp_dbf_hba_fsf_reqid - trace only the tag and a request ID
150  * @tag: tag documenting the source
151  * @level: trace level
152  * @adapter: adapter instance the request ID belongs to
153  * @req_id: the request ID to trace
154  */
155 void zfcp_dbf_hba_fsf_reqid(const char *const tag, const int level,
156 			    struct zfcp_adapter *const adapter,
157 			    const u64 req_id)
158 {
159 	struct zfcp_dbf *const dbf = adapter->dbf;
160 	struct zfcp_dbf_hba *const rec = &dbf->hba_buf;
161 	struct zfcp_dbf_hba_res *const res = &rec->u.res;
162 	unsigned long flags;
163 
164 	if (unlikely(!debug_level_enabled(dbf->hba, level)))
165 		return;
166 
167 	spin_lock_irqsave(&dbf->hba_lock, flags);
168 	memset(rec, 0, sizeof(*rec));
169 
170 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
171 
172 	rec->id = ZFCP_DBF_HBA_RES;
173 	rec->fsf_req_id = req_id;
174 	rec->fsf_req_status = ~0u;
175 	rec->fsf_cmd = ~0u;
176 	rec->fsf_seq_no = ~0u;
177 
178 	res->req_issued = ~0ull;
179 	res->prot_status = ~0u;
180 	memset(res->prot_status_qual, 0xff, sizeof(res->prot_status_qual));
181 	res->fsf_status = ~0u;
182 	memset(res->fsf_status_qual, 0xff, sizeof(res->fsf_status_qual));
183 	res->port_handle = ~0u;
184 	res->lun_handle = ~0u;
185 
186 	debug_event(dbf->hba, level, rec, sizeof(*rec));
187 	spin_unlock_irqrestore(&dbf->hba_lock, flags);
188 }
189 
190 /**
191  * zfcp_dbf_hba_fsf_uss - trace event for an unsolicited status buffer
192  * @tag: tag indicating which kind of unsolicited status has been received
193  * @req: request providing the unsolicited status
194  */
195 void zfcp_dbf_hba_fsf_uss(char *tag, struct zfcp_fsf_req *req)
196 {
197 	struct zfcp_dbf *dbf = req->adapter->dbf;
198 	struct fsf_status_read_buffer *srb = req->data;
199 	struct zfcp_dbf_hba *rec = &dbf->hba_buf;
200 	static int const level = 2;
201 	unsigned long flags;
202 
203 	if (unlikely(!debug_level_enabled(dbf->hba, level)))
204 		return;
205 
206 	spin_lock_irqsave(&dbf->hba_lock, flags);
207 	memset(rec, 0, sizeof(*rec));
208 
209 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
210 	rec->id = ZFCP_DBF_HBA_USS;
211 	rec->fsf_req_id = req->req_id;
212 	rec->fsf_req_status = req->status;
213 	rec->fsf_cmd = FSF_QTCB_UNSOLICITED_STATUS;
214 
215 	if (!srb)
216 		goto log;
217 
218 	rec->u.uss.status_type = srb->status_type;
219 	rec->u.uss.status_subtype = srb->status_subtype;
220 	rec->u.uss.d_id = ntoh24(srb->d_id);
221 	rec->u.uss.lun = srb->fcp_lun;
222 	memcpy(&rec->u.uss.queue_designator, &srb->queue_designator,
223 	       sizeof(rec->u.uss.queue_designator));
224 
225 	/* status read buffer payload length */
226 	rec->pl_len = (!srb->length) ? 0 : srb->length -
227 			offsetof(struct fsf_status_read_buffer, payload);
228 
229 	if (rec->pl_len)
230 		zfcp_dbf_pl_write(dbf, srb->payload.data, rec->pl_len,
231 				  "fsf_uss", req->req_id);
232 log:
233 	debug_event(dbf->hba, level, rec, sizeof(*rec));
234 	spin_unlock_irqrestore(&dbf->hba_lock, flags);
235 }
236 
237 /**
238  * zfcp_dbf_hba_bit_err - trace event for bit error conditions
239  * @tag: tag indicating which kind of bit error unsolicited status was received
240  * @req: request which caused the bit_error condition
241  */
242 void zfcp_dbf_hba_bit_err(char *tag, struct zfcp_fsf_req *req)
243 {
244 	struct zfcp_dbf *dbf = req->adapter->dbf;
245 	struct zfcp_dbf_hba *rec = &dbf->hba_buf;
246 	struct fsf_status_read_buffer *sr_buf = req->data;
247 	static int const level = 1;
248 	unsigned long flags;
249 
250 	if (unlikely(!debug_level_enabled(dbf->hba, level)))
251 		return;
252 
253 	spin_lock_irqsave(&dbf->hba_lock, flags);
254 	memset(rec, 0, sizeof(*rec));
255 
256 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
257 	rec->id = ZFCP_DBF_HBA_BIT;
258 	rec->fsf_req_id = req->req_id;
259 	rec->fsf_req_status = req->status;
260 	rec->fsf_cmd = FSF_QTCB_UNSOLICITED_STATUS;
261 	memcpy(&rec->u.be, &sr_buf->payload.bit_error,
262 	       sizeof(struct fsf_bit_error_payload));
263 
264 	debug_event(dbf->hba, level, rec, sizeof(*rec));
265 	spin_unlock_irqrestore(&dbf->hba_lock, flags);
266 }
267 
268 /**
269  * zfcp_dbf_hba_def_err - trace event for deferred error messages
270  * @adapter: pointer to struct zfcp_adapter
271  * @req_id: request id which caused the deferred error message
272  * @scount: number of sbals incl. the signaling sbal
273  * @pl: array of all involved sbals
274  */
275 void zfcp_dbf_hba_def_err(struct zfcp_adapter *adapter, u64 req_id, u16 scount,
276 			  void **pl)
277 {
278 	struct zfcp_dbf *dbf = adapter->dbf;
279 	struct zfcp_dbf_pay *payload = &dbf->pay_buf;
280 	unsigned long flags;
281 	static int const level = 1;
282 	u16 length;
283 
284 	if (unlikely(!debug_level_enabled(dbf->pay, level)))
285 		return;
286 
287 	if (!pl)
288 		return;
289 
290 	spin_lock_irqsave(&dbf->pay_lock, flags);
291 	memset(payload, 0, sizeof(*payload));
292 
293 	memcpy(payload->area, "def_err", 7);
294 	payload->fsf_req_id = req_id;
295 	payload->counter = 0;
296 	length = min((u16)sizeof(struct qdio_buffer),
297 		     (u16)ZFCP_DBF_PAY_MAX_REC);
298 
299 	while (payload->counter < scount && (char *)pl[payload->counter]) {
300 		memcpy(payload->data, (char *)pl[payload->counter], length);
301 		debug_event(dbf->pay, level, payload, zfcp_dbf_plen(length));
302 		payload->counter++;
303 	}
304 
305 	spin_unlock_irqrestore(&dbf->pay_lock, flags);
306 }
307 
308 static void zfcp_dbf_set_common(struct zfcp_dbf_rec *rec,
309 				struct zfcp_adapter *adapter,
310 				struct zfcp_port *port,
311 				struct scsi_device *sdev)
312 {
313 	rec->adapter_status = atomic_read(&adapter->status);
314 	if (port) {
315 		rec->port_status = atomic_read(&port->status);
316 		rec->wwpn = port->wwpn;
317 		rec->d_id = port->d_id;
318 	}
319 	if (sdev) {
320 		rec->lun_status = atomic_read(&sdev_to_zfcp(sdev)->status);
321 		rec->lun = zfcp_scsi_dev_lun(sdev);
322 	} else
323 		rec->lun = ZFCP_DBF_INVALID_LUN;
324 }
325 
326 /**
327  * zfcp_dbf_rec_trig - trace event related to triggered recovery
328  * @tag: identifier for event
329  * @adapter: adapter on which the erp_action should run
330  * @port: remote port involved in the erp_action
331  * @sdev: scsi device involved in the erp_action
332  * @want: wanted erp_action
333  * @need: required erp_action
334  *
335  * The adapter->erp_lock has to be held.
336  */
337 void zfcp_dbf_rec_trig(char *tag, struct zfcp_adapter *adapter,
338 		       struct zfcp_port *port, struct scsi_device *sdev,
339 		       u8 want, u8 need)
340 {
341 	struct zfcp_dbf *dbf = adapter->dbf;
342 	struct zfcp_dbf_rec *rec = &dbf->rec_buf;
343 	static int const level = 1;
344 	struct list_head *entry;
345 	unsigned long flags;
346 
347 	lockdep_assert_held(&adapter->erp_lock);
348 
349 	if (unlikely(!debug_level_enabled(dbf->rec, level)))
350 		return;
351 
352 	spin_lock_irqsave(&dbf->rec_lock, flags);
353 	memset(rec, 0, sizeof(*rec));
354 
355 	rec->id = ZFCP_DBF_REC_TRIG;
356 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
357 	zfcp_dbf_set_common(rec, adapter, port, sdev);
358 
359 	list_for_each(entry, &adapter->erp_ready_head)
360 		rec->u.trig.ready++;
361 
362 	list_for_each(entry, &adapter->erp_running_head)
363 		rec->u.trig.running++;
364 
365 	rec->u.trig.want = want;
366 	rec->u.trig.need = need;
367 
368 	debug_event(dbf->rec, level, rec, sizeof(*rec));
369 	spin_unlock_irqrestore(&dbf->rec_lock, flags);
370 }
371 
372 /**
373  * zfcp_dbf_rec_trig_lock - trace event related to triggered recovery with lock
374  * @tag: identifier for event
375  * @adapter: adapter on which the erp_action should run
376  * @port: remote port involved in the erp_action
377  * @sdev: scsi device involved in the erp_action
378  * @want: wanted erp_action
379  * @need: required erp_action
380  *
381  * The adapter->erp_lock must not be held.
382  */
383 void zfcp_dbf_rec_trig_lock(char *tag, struct zfcp_adapter *adapter,
384 			    struct zfcp_port *port, struct scsi_device *sdev,
385 			    u8 want, u8 need)
386 {
387 	unsigned long flags;
388 
389 	read_lock_irqsave(&adapter->erp_lock, flags);
390 	zfcp_dbf_rec_trig(tag, adapter, port, sdev, want, need);
391 	read_unlock_irqrestore(&adapter->erp_lock, flags);
392 }
393 
394 /**
395  * zfcp_dbf_rec_run_lvl - trace event related to running recovery
396  * @level: trace level to be used for event
397  * @tag: identifier for event
398  * @erp: erp_action running
399  */
400 void zfcp_dbf_rec_run_lvl(int level, char *tag, struct zfcp_erp_action *erp)
401 {
402 	struct zfcp_dbf *dbf = erp->adapter->dbf;
403 	struct zfcp_dbf_rec *rec = &dbf->rec_buf;
404 	unsigned long flags;
405 
406 	if (!debug_level_enabled(dbf->rec, level))
407 		return;
408 
409 	spin_lock_irqsave(&dbf->rec_lock, flags);
410 	memset(rec, 0, sizeof(*rec));
411 
412 	rec->id = ZFCP_DBF_REC_RUN;
413 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
414 	zfcp_dbf_set_common(rec, erp->adapter, erp->port, erp->sdev);
415 
416 	rec->u.run.fsf_req_id = erp->fsf_req_id;
417 	rec->u.run.rec_status = erp->status;
418 	rec->u.run.rec_step = erp->step;
419 	rec->u.run.rec_action = erp->type;
420 
421 	if (erp->sdev)
422 		rec->u.run.rec_count =
423 			atomic_read(&sdev_to_zfcp(erp->sdev)->erp_counter);
424 	else if (erp->port)
425 		rec->u.run.rec_count = atomic_read(&erp->port->erp_counter);
426 	else
427 		rec->u.run.rec_count = atomic_read(&erp->adapter->erp_counter);
428 
429 	debug_event(dbf->rec, level, rec, sizeof(*rec));
430 	spin_unlock_irqrestore(&dbf->rec_lock, flags);
431 }
432 
433 /**
434  * zfcp_dbf_rec_run - trace event related to running recovery
435  * @tag: identifier for event
436  * @erp: erp_action running
437  */
438 void zfcp_dbf_rec_run(char *tag, struct zfcp_erp_action *erp)
439 {
440 	zfcp_dbf_rec_run_lvl(1, tag, erp);
441 }
442 
443 /**
444  * zfcp_dbf_rec_run_wka - trace wka port event with info like running recovery
445  * @tag: identifier for event
446  * @wka_port: well known address port
447  * @req_id: request ID to correlate with potential HBA trace record
448  */
449 void zfcp_dbf_rec_run_wka(char *tag, struct zfcp_fc_wka_port *wka_port,
450 			  u64 req_id)
451 {
452 	struct zfcp_dbf *dbf = wka_port->adapter->dbf;
453 	struct zfcp_dbf_rec *rec = &dbf->rec_buf;
454 	static int const level = 1;
455 	unsigned long flags;
456 
457 	if (unlikely(!debug_level_enabled(dbf->rec, level)))
458 		return;
459 
460 	spin_lock_irqsave(&dbf->rec_lock, flags);
461 	memset(rec, 0, sizeof(*rec));
462 
463 	rec->id = ZFCP_DBF_REC_RUN;
464 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
465 	rec->port_status = wka_port->status;
466 	rec->d_id = wka_port->d_id;
467 	rec->lun = ZFCP_DBF_INVALID_LUN;
468 
469 	rec->u.run.fsf_req_id = req_id;
470 	rec->u.run.rec_status = ~0;
471 	rec->u.run.rec_step = ~0;
472 	rec->u.run.rec_action = ~0;
473 	rec->u.run.rec_count = ~0;
474 
475 	debug_event(dbf->rec, level, rec, sizeof(*rec));
476 	spin_unlock_irqrestore(&dbf->rec_lock, flags);
477 }
478 
479 #define ZFCP_DBF_SAN_LEVEL 1
480 
481 static inline
482 void zfcp_dbf_san(char *tag, struct zfcp_dbf *dbf,
483 		  char *paytag, struct scatterlist *sg, u8 id, u16 len,
484 		  u64 req_id, u32 d_id, u16 cap_len)
485 {
486 	struct zfcp_dbf_san *rec = &dbf->san_buf;
487 	u16 rec_len;
488 	unsigned long flags;
489 	struct zfcp_dbf_pay *payload = &dbf->pay_buf;
490 	u16 pay_sum = 0;
491 
492 	spin_lock_irqsave(&dbf->san_lock, flags);
493 	memset(rec, 0, sizeof(*rec));
494 
495 	rec->id = id;
496 	rec->fsf_req_id = req_id;
497 	rec->d_id = d_id;
498 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
499 	rec->pl_len = len; /* full length even if we cap pay below */
500 	if (!sg)
501 		goto out;
502 	rec_len = min_t(unsigned int, sg->length, ZFCP_DBF_SAN_MAX_PAYLOAD);
503 	memcpy(rec->payload, sg_virt(sg), rec_len); /* part of 1st sg entry */
504 	if (len <= rec_len)
505 		goto out; /* skip pay record if full content in rec->payload */
506 
507 	/* if (len > rec_len):
508 	 * dump data up to cap_len ignoring small duplicate in rec->payload
509 	 */
510 	spin_lock(&dbf->pay_lock);
511 	memset(payload, 0, sizeof(*payload));
512 	memcpy(payload->area, paytag, ZFCP_DBF_TAG_LEN);
513 	payload->fsf_req_id = req_id;
514 	payload->counter = 0;
515 	for (; sg && pay_sum < cap_len; sg = sg_next(sg)) {
516 		u16 pay_len, offset = 0;
517 
518 		while (offset < sg->length && pay_sum < cap_len) {
519 			pay_len = min((u16)ZFCP_DBF_PAY_MAX_REC,
520 				      (u16)(sg->length - offset));
521 			/* cap_len <= pay_sum < cap_len+ZFCP_DBF_PAY_MAX_REC */
522 			memcpy(payload->data, sg_virt(sg) + offset, pay_len);
523 			debug_event(dbf->pay, ZFCP_DBF_SAN_LEVEL, payload,
524 				    zfcp_dbf_plen(pay_len));
525 			payload->counter++;
526 			offset += pay_len;
527 			pay_sum += pay_len;
528 		}
529 	}
530 	spin_unlock(&dbf->pay_lock);
531 
532 out:
533 	debug_event(dbf->san, ZFCP_DBF_SAN_LEVEL, rec, sizeof(*rec));
534 	spin_unlock_irqrestore(&dbf->san_lock, flags);
535 }
536 
537 /**
538  * zfcp_dbf_san_req - trace event for issued SAN request
539  * @tag: identifier for event
540  * @fsf: request containing issued CT or ELS data
541  * @d_id: N_Port_ID where SAN request is sent to
542  * d_id: destination ID
543  */
544 void zfcp_dbf_san_req(char *tag, struct zfcp_fsf_req *fsf, u32 d_id)
545 {
546 	struct zfcp_dbf *dbf = fsf->adapter->dbf;
547 	struct zfcp_fsf_ct_els *ct_els = fsf->data;
548 	u16 length;
549 
550 	if (unlikely(!debug_level_enabled(dbf->san, ZFCP_DBF_SAN_LEVEL)))
551 		return;
552 
553 	length = (u16)zfcp_qdio_real_bytes(ct_els->req);
554 	zfcp_dbf_san(tag, dbf, "san_req", ct_els->req, ZFCP_DBF_SAN_REQ,
555 		     length, fsf->req_id, d_id, length);
556 }
557 
558 static u16 zfcp_dbf_san_res_cap_len_if_gpn_ft(char *tag,
559 					      struct zfcp_fsf_req *fsf,
560 					      u16 len)
561 {
562 	struct zfcp_fsf_ct_els *ct_els = fsf->data;
563 	struct fc_ct_hdr *reqh = sg_virt(ct_els->req);
564 	struct fc_ns_gid_ft *reqn = (struct fc_ns_gid_ft *)(reqh + 1);
565 	struct scatterlist *resp_entry = ct_els->resp;
566 	struct fc_ct_hdr *resph;
567 	struct fc_gpn_ft_resp *acc;
568 	int max_entries, x, last = 0;
569 
570 	if (!(memcmp(tag, "fsscth2", 7) == 0
571 	      && ct_els->d_id == FC_FID_DIR_SERV
572 	      && reqh->ct_rev == FC_CT_REV
573 	      && reqh->ct_in_id[0] == 0
574 	      && reqh->ct_in_id[1] == 0
575 	      && reqh->ct_in_id[2] == 0
576 	      && reqh->ct_fs_type == FC_FST_DIR
577 	      && reqh->ct_fs_subtype == FC_NS_SUBTYPE
578 	      && reqh->ct_options == 0
579 	      && reqh->_ct_resvd1 == 0
580 	      && reqh->ct_cmd == cpu_to_be16(FC_NS_GPN_FT)
581 	      /* reqh->ct_mr_size can vary so do not match but read below */
582 	      && reqh->_ct_resvd2 == 0
583 	      && reqh->ct_reason == 0
584 	      && reqh->ct_explan == 0
585 	      && reqh->ct_vendor == 0
586 	      && reqn->fn_resvd == 0
587 	      && reqn->fn_domain_id_scope == 0
588 	      && reqn->fn_area_id_scope == 0
589 	      && reqn->fn_fc4_type == FC_TYPE_FCP))
590 		return len; /* not GPN_FT response so do not cap */
591 
592 	acc = sg_virt(resp_entry);
593 
594 	/* cap all but accept CT responses to at least the CT header */
595 	resph = (struct fc_ct_hdr *)acc;
596 	if ((ct_els->status) ||
597 	    (resph->ct_cmd != cpu_to_be16(FC_FS_ACC)))
598 		return max(FC_CT_HDR_LEN, ZFCP_DBF_SAN_MAX_PAYLOAD);
599 
600 	max_entries = (be16_to_cpu(reqh->ct_mr_size) * 4 /
601 		       sizeof(struct fc_gpn_ft_resp))
602 		+ 1 /* zfcp_fc_scan_ports: bytes correct, entries off-by-one
603 		     * to account for header as 1st pseudo "entry" */;
604 
605 	/* the basic CT_IU preamble is the same size as one entry in the GPN_FT
606 	 * response, allowing us to skip special handling for it - just skip it
607 	 */
608 	for (x = 1; x < max_entries && !last; x++) {
609 		if (x % (ZFCP_FC_GPN_FT_ENT_PAGE + 1))
610 			acc++;
611 		else
612 			acc = sg_virt(++resp_entry);
613 
614 		last = acc->fp_flags & FC_NS_FID_LAST;
615 	}
616 	len = min(len, (u16)(x * sizeof(struct fc_gpn_ft_resp)));
617 	return len; /* cap after last entry */
618 }
619 
620 /**
621  * zfcp_dbf_san_res - trace event for received SAN request
622  * @tag: identifier for event
623  * @fsf: request containing received CT or ELS data
624  */
625 void zfcp_dbf_san_res(char *tag, struct zfcp_fsf_req *fsf)
626 {
627 	struct zfcp_dbf *dbf = fsf->adapter->dbf;
628 	struct zfcp_fsf_ct_els *ct_els = fsf->data;
629 	u16 length;
630 
631 	if (unlikely(!debug_level_enabled(dbf->san, ZFCP_DBF_SAN_LEVEL)))
632 		return;
633 
634 	length = (u16)zfcp_qdio_real_bytes(ct_els->resp);
635 	zfcp_dbf_san(tag, dbf, "san_res", ct_els->resp, ZFCP_DBF_SAN_RES,
636 		     length, fsf->req_id, ct_els->d_id,
637 		     zfcp_dbf_san_res_cap_len_if_gpn_ft(tag, fsf, length));
638 }
639 
640 /**
641  * zfcp_dbf_san_in_els - trace event for incoming ELS
642  * @tag: identifier for event
643  * @fsf: request containing received ELS data
644  */
645 void zfcp_dbf_san_in_els(char *tag, struct zfcp_fsf_req *fsf)
646 {
647 	struct zfcp_dbf *dbf = fsf->adapter->dbf;
648 	struct fsf_status_read_buffer *srb =
649 		(struct fsf_status_read_buffer *) fsf->data;
650 	u16 length;
651 	struct scatterlist sg;
652 
653 	if (unlikely(!debug_level_enabled(dbf->san, ZFCP_DBF_SAN_LEVEL)))
654 		return;
655 
656 	length = (u16)(srb->length -
657 			offsetof(struct fsf_status_read_buffer, payload));
658 	sg_init_one(&sg, srb->payload.data, length);
659 	zfcp_dbf_san(tag, dbf, "san_els", &sg, ZFCP_DBF_SAN_ELS, length,
660 		     fsf->req_id, ntoh24(srb->d_id), length);
661 }
662 
663 /**
664  * zfcp_dbf_scsi_common() - Common trace event helper for scsi.
665  * @tag: Identifier for event.
666  * @level: trace level of event.
667  * @sdev: Pointer to SCSI device as context for this event.
668  * @sc: Pointer to SCSI command, or NULL with task management function (TMF).
669  * @fsf: Pointer to FSF request, or NULL.
670  */
671 void zfcp_dbf_scsi_common(char *tag, int level, struct scsi_device *sdev,
672 			  struct scsi_cmnd *sc, struct zfcp_fsf_req *fsf)
673 {
674 	struct zfcp_adapter *adapter =
675 		(struct zfcp_adapter *) sdev->host->hostdata[0];
676 	struct zfcp_dbf *dbf = adapter->dbf;
677 	struct zfcp_dbf_scsi *rec = &dbf->scsi_buf;
678 	struct fcp_resp_with_ext *fcp_rsp;
679 	struct fcp_resp_rsp_info *fcp_rsp_info;
680 	unsigned long flags;
681 
682 	spin_lock_irqsave(&dbf->scsi_lock, flags);
683 	memset(rec, 0, sizeof(*rec));
684 
685 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
686 	rec->id = ZFCP_DBF_SCSI_CMND;
687 	if (sc) {
688 		rec->scsi_result = sc->result;
689 		rec->scsi_retries = sc->retries;
690 		rec->scsi_allowed = sc->allowed;
691 		rec->scsi_id = sc->device->id;
692 		rec->scsi_lun = (u32)sc->device->lun;
693 		rec->scsi_lun_64_hi = (u32)(sc->device->lun >> 32);
694 		rec->host_scribble = (u64)sc->host_scribble;
695 
696 		memcpy(rec->scsi_opcode, sc->cmnd,
697 		       min_t(int, sc->cmd_len, ZFCP_DBF_SCSI_OPCODE));
698 	} else {
699 		rec->scsi_result = ~0;
700 		rec->scsi_retries = ~0;
701 		rec->scsi_allowed = ~0;
702 		rec->scsi_id = sdev->id;
703 		rec->scsi_lun = (u32)sdev->lun;
704 		rec->scsi_lun_64_hi = (u32)(sdev->lun >> 32);
705 		rec->host_scribble = ~0;
706 
707 		memset(rec->scsi_opcode, 0xff, ZFCP_DBF_SCSI_OPCODE);
708 	}
709 
710 	if (fsf) {
711 		rec->fsf_req_id = fsf->req_id;
712 		rec->pl_len = FCP_RESP_WITH_EXT;
713 		fcp_rsp = &(fsf->qtcb->bottom.io.fcp_rsp.iu);
714 		/* mandatory parts of FCP_RSP IU in this SCSI record */
715 		memcpy(&rec->fcp_rsp, fcp_rsp, FCP_RESP_WITH_EXT);
716 		if (fcp_rsp->resp.fr_flags & FCP_RSP_LEN_VAL) {
717 			fcp_rsp_info = (struct fcp_resp_rsp_info *) &fcp_rsp[1];
718 			rec->fcp_rsp_info = fcp_rsp_info->rsp_code;
719 			rec->pl_len += be32_to_cpu(fcp_rsp->ext.fr_rsp_len);
720 		}
721 		if (fcp_rsp->resp.fr_flags & FCP_SNS_LEN_VAL) {
722 			rec->pl_len += be32_to_cpu(fcp_rsp->ext.fr_sns_len);
723 		}
724 		/* complete FCP_RSP IU in associated PAYload record
725 		 * but only if there are optional parts
726 		 */
727 		if (fcp_rsp->resp.fr_flags != 0)
728 			zfcp_dbf_pl_write(
729 				dbf, fcp_rsp,
730 				/* at least one full PAY record
731 				 * but not beyond hardware response field
732 				 */
733 				min_t(u16, max_t(u16, rec->pl_len,
734 						 ZFCP_DBF_PAY_MAX_REC),
735 				      FSF_FCP_RSP_SIZE),
736 				"fcp_riu", fsf->req_id);
737 	}
738 
739 	debug_event(dbf->scsi, level, rec, sizeof(*rec));
740 	spin_unlock_irqrestore(&dbf->scsi_lock, flags);
741 }
742 
743 /**
744  * zfcp_dbf_scsi_eh() - Trace event for special cases of scsi_eh callbacks.
745  * @tag: Identifier for event.
746  * @adapter: Pointer to zfcp adapter as context for this event.
747  * @scsi_id: SCSI ID/target to indicate scope of task management function (TMF).
748  * @ret: Return value of calling function.
749  *
750  * This SCSI trace variant does not depend on any of:
751  * scsi_cmnd, zfcp_fsf_req, scsi_device.
752  */
753 void zfcp_dbf_scsi_eh(char *tag, struct zfcp_adapter *adapter,
754 		      unsigned int scsi_id, int ret)
755 {
756 	struct zfcp_dbf *dbf = adapter->dbf;
757 	struct zfcp_dbf_scsi *rec = &dbf->scsi_buf;
758 	unsigned long flags;
759 	static int const level = 1;
760 
761 	if (unlikely(!debug_level_enabled(adapter->dbf->scsi, level)))
762 		return;
763 
764 	spin_lock_irqsave(&dbf->scsi_lock, flags);
765 	memset(rec, 0, sizeof(*rec));
766 
767 	memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
768 	rec->id = ZFCP_DBF_SCSI_CMND;
769 	rec->scsi_result = ret; /* re-use field, int is 4 bytes and fits */
770 	rec->scsi_retries = ~0;
771 	rec->scsi_allowed = ~0;
772 	rec->fcp_rsp_info = ~0;
773 	rec->scsi_id = scsi_id;
774 	rec->scsi_lun = (u32)ZFCP_DBF_INVALID_LUN;
775 	rec->scsi_lun_64_hi = (u32)(ZFCP_DBF_INVALID_LUN >> 32);
776 	rec->host_scribble = ~0;
777 	memset(rec->scsi_opcode, 0xff, ZFCP_DBF_SCSI_OPCODE);
778 
779 	debug_event(dbf->scsi, level, rec, sizeof(*rec));
780 	spin_unlock_irqrestore(&dbf->scsi_lock, flags);
781 }
782 
783 static debug_info_t *zfcp_dbf_reg(const char *name, int size, int rec_size)
784 {
785 	struct debug_info *d;
786 
787 	d = debug_register(name, size, 1, rec_size);
788 	if (!d)
789 		return NULL;
790 
791 	debug_register_view(d, &debug_hex_ascii_view);
792 	debug_set_level(d, dbflevel);
793 
794 	return d;
795 }
796 
797 static void zfcp_dbf_unregister(struct zfcp_dbf *dbf)
798 {
799 	if (!dbf)
800 		return;
801 
802 	debug_unregister(dbf->scsi);
803 	debug_unregister(dbf->san);
804 	debug_unregister(dbf->hba);
805 	debug_unregister(dbf->pay);
806 	debug_unregister(dbf->rec);
807 	kfree(dbf);
808 }
809 
810 /**
811  * zfcp_dbf_adapter_register - registers debug feature for an adapter
812  * @adapter: pointer to adapter for which debug features should be registered
813  * return: -ENOMEM on error, 0 otherwise
814  */
815 int zfcp_dbf_adapter_register(struct zfcp_adapter *adapter)
816 {
817 	char name[DEBUG_MAX_NAME_LEN];
818 	struct zfcp_dbf *dbf;
819 
820 	dbf = kzalloc(sizeof(struct zfcp_dbf), GFP_KERNEL);
821 	if (!dbf)
822 		return -ENOMEM;
823 
824 	spin_lock_init(&dbf->pay_lock);
825 	spin_lock_init(&dbf->hba_lock);
826 	spin_lock_init(&dbf->san_lock);
827 	spin_lock_init(&dbf->scsi_lock);
828 	spin_lock_init(&dbf->rec_lock);
829 
830 	/* debug feature area which records recovery activity */
831 	sprintf(name, "zfcp_%s_rec", dev_name(&adapter->ccw_device->dev));
832 	dbf->rec = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_rec));
833 	if (!dbf->rec)
834 		goto err_out;
835 
836 	/* debug feature area which records HBA (FSF and QDIO) conditions */
837 	sprintf(name, "zfcp_%s_hba", dev_name(&adapter->ccw_device->dev));
838 	dbf->hba = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_hba));
839 	if (!dbf->hba)
840 		goto err_out;
841 
842 	/* debug feature area which records payload info */
843 	sprintf(name, "zfcp_%s_pay", dev_name(&adapter->ccw_device->dev));
844 	dbf->pay = zfcp_dbf_reg(name, dbfsize * 2, sizeof(struct zfcp_dbf_pay));
845 	if (!dbf->pay)
846 		goto err_out;
847 
848 	/* debug feature area which records SAN command failures and recovery */
849 	sprintf(name, "zfcp_%s_san", dev_name(&adapter->ccw_device->dev));
850 	dbf->san = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_san));
851 	if (!dbf->san)
852 		goto err_out;
853 
854 	/* debug feature area which records SCSI command failures and recovery */
855 	sprintf(name, "zfcp_%s_scsi", dev_name(&adapter->ccw_device->dev));
856 	dbf->scsi = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_scsi));
857 	if (!dbf->scsi)
858 		goto err_out;
859 
860 	adapter->dbf = dbf;
861 
862 	return 0;
863 err_out:
864 	zfcp_dbf_unregister(dbf);
865 	return -ENOMEM;
866 }
867 
868 /**
869  * zfcp_dbf_adapter_unregister - unregisters debug feature for an adapter
870  * @adapter: pointer to adapter for which debug features should be unregistered
871  */
872 void zfcp_dbf_adapter_unregister(struct zfcp_adapter *adapter)
873 {
874 	struct zfcp_dbf *dbf = adapter->dbf;
875 
876 	adapter->dbf = NULL;
877 	zfcp_dbf_unregister(dbf);
878 }
879 
880