xref: /linux/drivers/s390/scsi/zfcp_scsi.c (revision 5e8d780d745c1619aba81fe7166c5a4b5cad2b84)
1 /*
2  * This file is part of the zfcp device driver for
3  * FCP adapters for IBM System z9 and zSeries.
4  *
5  * (C) Copyright IBM Corp. 2002, 2006
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2, or (at your option)
10  * any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #define ZFCP_LOG_AREA			ZFCP_LOG_AREA_SCSI
23 
24 #include "zfcp_ext.h"
25 
26 static void zfcp_scsi_slave_destroy(struct scsi_device *sdp);
27 static int zfcp_scsi_slave_alloc(struct scsi_device *sdp);
28 static int zfcp_scsi_slave_configure(struct scsi_device *sdp);
29 static int zfcp_scsi_queuecommand(struct scsi_cmnd *,
30 				  void (*done) (struct scsi_cmnd *));
31 static int zfcp_scsi_eh_abort_handler(struct scsi_cmnd *);
32 static int zfcp_scsi_eh_device_reset_handler(struct scsi_cmnd *);
33 static int zfcp_scsi_eh_bus_reset_handler(struct scsi_cmnd *);
34 static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *);
35 static int zfcp_task_management_function(struct zfcp_unit *, u8,
36 					 struct scsi_cmnd *);
37 
38 static struct zfcp_unit *zfcp_unit_lookup(struct zfcp_adapter *, int,
39 					  unsigned int, unsigned int);
40 
41 static struct device_attribute *zfcp_sysfs_sdev_attrs[];
42 
43 struct scsi_transport_template *zfcp_transport_template;
44 
45 struct zfcp_data zfcp_data = {
46 	.scsi_host_template = {
47 	      name:	               ZFCP_NAME,
48 	      proc_name:               "zfcp",
49 	      proc_info:               NULL,
50 	      detect:	               NULL,
51 	      slave_alloc:             zfcp_scsi_slave_alloc,
52 	      slave_configure:         zfcp_scsi_slave_configure,
53 	      slave_destroy:           zfcp_scsi_slave_destroy,
54 	      queuecommand:            zfcp_scsi_queuecommand,
55 	      eh_abort_handler:        zfcp_scsi_eh_abort_handler,
56 	      eh_device_reset_handler: zfcp_scsi_eh_device_reset_handler,
57 	      eh_bus_reset_handler:    zfcp_scsi_eh_bus_reset_handler,
58 	      eh_host_reset_handler:   zfcp_scsi_eh_host_reset_handler,
59 			               /* FIXME(openfcp): Tune */
60 	      can_queue:               4096,
61 	      this_id:	               -1,
62 	      /*
63 	       * FIXME:
64 	       * one less? can zfcp_create_sbale cope with it?
65 	       */
66 	      sg_tablesize:            ZFCP_MAX_SBALES_PER_REQ,
67 	      cmd_per_lun:             1,
68 	      unchecked_isa_dma:       0,
69 	      use_clustering:          1,
70 	      sdev_attrs:              zfcp_sysfs_sdev_attrs,
71 	},
72 	.driver_version = ZFCP_VERSION,
73 	/* rest initialised with zeros */
74 };
75 
76 /* Find start of Response Information in FCP response unit*/
77 char *
78 zfcp_get_fcp_rsp_info_ptr(struct fcp_rsp_iu *fcp_rsp_iu)
79 {
80 	char *fcp_rsp_info_ptr;
81 
82 	fcp_rsp_info_ptr =
83 	    (unsigned char *) fcp_rsp_iu + (sizeof (struct fcp_rsp_iu));
84 
85 	return fcp_rsp_info_ptr;
86 }
87 
88 /* Find start of Sense Information in FCP response unit*/
89 char *
90 zfcp_get_fcp_sns_info_ptr(struct fcp_rsp_iu *fcp_rsp_iu)
91 {
92 	char *fcp_sns_info_ptr;
93 
94 	fcp_sns_info_ptr =
95 	    (unsigned char *) fcp_rsp_iu + (sizeof (struct fcp_rsp_iu));
96 	if (fcp_rsp_iu->validity.bits.fcp_rsp_len_valid)
97 		fcp_sns_info_ptr = (char *) fcp_sns_info_ptr +
98 		    fcp_rsp_iu->fcp_rsp_len;
99 
100 	return fcp_sns_info_ptr;
101 }
102 
103 fcp_dl_t *
104 zfcp_get_fcp_dl_ptr(struct fcp_cmnd_iu * fcp_cmd)
105 {
106 	int additional_length = fcp_cmd->add_fcp_cdb_length << 2;
107 	fcp_dl_t *fcp_dl_addr;
108 
109 	fcp_dl_addr = (fcp_dl_t *)
110 		((unsigned char *) fcp_cmd +
111 		 sizeof (struct fcp_cmnd_iu) + additional_length);
112 	/*
113 	 * fcp_dl_addr = start address of fcp_cmnd structure +
114 	 * size of fixed part + size of dynamically sized add_dcp_cdb field
115 	 * SEE FCP-2 documentation
116 	 */
117 	return fcp_dl_addr;
118 }
119 
120 fcp_dl_t
121 zfcp_get_fcp_dl(struct fcp_cmnd_iu * fcp_cmd)
122 {
123 	return *zfcp_get_fcp_dl_ptr(fcp_cmd);
124 }
125 
126 void
127 zfcp_set_fcp_dl(struct fcp_cmnd_iu *fcp_cmd, fcp_dl_t fcp_dl)
128 {
129 	*zfcp_get_fcp_dl_ptr(fcp_cmd) = fcp_dl;
130 }
131 
132 /*
133  * note: it's a bit-or operation not an assignment
134  * regarding the specified byte
135  */
136 static inline void
137 set_byte(u32 * result, char status, char pos)
138 {
139 	*result |= status << (pos * 8);
140 }
141 
142 void
143 set_host_byte(u32 * result, char status)
144 {
145 	set_byte(result, status, 2);
146 }
147 
148 void
149 set_driver_byte(u32 * result, char status)
150 {
151 	set_byte(result, status, 3);
152 }
153 
154 static int
155 zfcp_scsi_slave_alloc(struct scsi_device *sdp)
156 {
157 	struct zfcp_adapter *adapter;
158 	struct zfcp_unit *unit;
159 	unsigned long flags;
160 	int retval = -ENXIO;
161 
162 	adapter = (struct zfcp_adapter *) sdp->host->hostdata[0];
163 	if (!adapter)
164 		goto out;
165 
166 	read_lock_irqsave(&zfcp_data.config_lock, flags);
167 	unit = zfcp_unit_lookup(adapter, sdp->channel, sdp->id, sdp->lun);
168 	if (unit && atomic_test_mask(ZFCP_STATUS_UNIT_REGISTERED,
169 				     &unit->status)) {
170 		sdp->hostdata = unit;
171 		unit->device = sdp;
172 		zfcp_unit_get(unit);
173 		retval = 0;
174 	}
175 	read_unlock_irqrestore(&zfcp_data.config_lock, flags);
176  out:
177 	return retval;
178 }
179 
180 static void
181 zfcp_scsi_slave_destroy(struct scsi_device *sdpnt)
182 {
183 	struct zfcp_unit *unit = (struct zfcp_unit *) sdpnt->hostdata;
184 
185 	if (unit) {
186 		atomic_clear_mask(ZFCP_STATUS_UNIT_REGISTERED, &unit->status);
187 		sdpnt->hostdata = NULL;
188 		unit->device = NULL;
189 		zfcp_unit_put(unit);
190 	} else {
191 		ZFCP_LOG_NORMAL("bug: no unit associated with SCSI device at "
192 				"address %p\n", sdpnt);
193 	}
194 }
195 
196 /*
197  * called from scsi midlayer to allow finetuning of a device.
198  */
199 static int
200 zfcp_scsi_slave_configure(struct scsi_device *sdp)
201 {
202 	if (sdp->tagged_supported)
203 		scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, ZFCP_CMND_PER_LUN);
204 	else
205 		scsi_adjust_queue_depth(sdp, 0, 1);
206 	return 0;
207 }
208 
209 /**
210  * zfcp_scsi_command_fail - set result in scsi_cmnd and call scsi_done function
211  * @scpnt: pointer to struct scsi_cmnd where result is set
212  * @result: result to be set in scpnt (e.g. DID_ERROR)
213  */
214 static void
215 zfcp_scsi_command_fail(struct scsi_cmnd *scpnt, int result)
216 {
217 	set_host_byte(&scpnt->result, result);
218 	if ((scpnt->device != NULL) && (scpnt->device->host != NULL))
219 		zfcp_scsi_dbf_event_result("fail", 4,
220 			(struct zfcp_adapter*) scpnt->device->host->hostdata[0],
221 			scpnt, NULL);
222 	/* return directly */
223 	scpnt->scsi_done(scpnt);
224 }
225 
226 /**
227  * zfcp_scsi_command_async - worker for zfcp_scsi_queuecommand and
228  *	zfcp_scsi_command_sync
229  * @adapter: adapter where scsi command is issued
230  * @unit: unit to which scsi command is sent
231  * @scpnt: scsi command to be sent
232  * @timer: timer to be started if request is successfully initiated
233  *
234  * Note: In scsi_done function must be set in scpnt.
235  */
236 int
237 zfcp_scsi_command_async(struct zfcp_adapter *adapter, struct zfcp_unit *unit,
238 			struct scsi_cmnd *scpnt, struct timer_list *timer)
239 {
240 	int tmp;
241 	int retval;
242 
243 	retval = 0;
244 
245 	BUG_ON((adapter == NULL) || (adapter != unit->port->adapter));
246 	BUG_ON(scpnt->scsi_done == NULL);
247 
248 	if (unlikely(NULL == unit)) {
249 		zfcp_scsi_command_fail(scpnt, DID_NO_CONNECT);
250 		goto out;
251 	}
252 
253 	if (unlikely(
254 	      atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &unit->status) ||
255 	     !atomic_test_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status))) {
256 		ZFCP_LOG_DEBUG("stopping SCSI I/O on unit 0x%016Lx on port "
257 			       "0x%016Lx on adapter %s\n",
258 			       unit->fcp_lun, unit->port->wwpn,
259 			       zfcp_get_busid_by_adapter(adapter));
260 		zfcp_scsi_command_fail(scpnt, DID_ERROR);
261 		goto out;
262 	}
263 
264 	if (unlikely(
265 	     !atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &unit->status))) {
266 		ZFCP_LOG_DEBUG("adapter %s not ready or unit 0x%016Lx "
267 			       "on port 0x%016Lx in recovery\n",
268 			       zfcp_get_busid_by_unit(unit),
269 			       unit->fcp_lun, unit->port->wwpn);
270 		zfcp_scsi_command_fail(scpnt, DID_NO_CONNECT);
271 		goto out;
272 	}
273 
274 	tmp = zfcp_fsf_send_fcp_command_task(adapter, unit, scpnt, timer,
275 					     ZFCP_REQ_AUTO_CLEANUP);
276 
277 	if (unlikely(tmp < 0)) {
278 		ZFCP_LOG_DEBUG("error: initiation of Send FCP Cmnd failed\n");
279 		retval = SCSI_MLQUEUE_HOST_BUSY;
280 	}
281 
282 out:
283 	return retval;
284 }
285 
286 void
287 zfcp_scsi_command_sync_handler(struct scsi_cmnd *scpnt)
288 {
289 	struct completion *wait = (struct completion *) scpnt->SCp.ptr;
290 	complete(wait);
291 }
292 
293 
294 /**
295  * zfcp_scsi_command_sync - send a SCSI command and wait for completion
296  * @unit: unit where command is sent to
297  * @scpnt: scsi command to be sent
298  * @timer: timer to be started if request is successfully initiated
299  * Return: 0
300  *
301  * Errors are indicated in scpnt->result
302  */
303 int
304 zfcp_scsi_command_sync(struct zfcp_unit *unit, struct scsi_cmnd *scpnt,
305 		       struct timer_list *timer)
306 {
307 	int ret;
308 	DECLARE_COMPLETION(wait);
309 
310 	scpnt->SCp.ptr = (void *) &wait;  /* silent re-use */
311 	scpnt->scsi_done = zfcp_scsi_command_sync_handler;
312 	ret = zfcp_scsi_command_async(unit->port->adapter, unit, scpnt, timer);
313 	if (ret == 0)
314 		wait_for_completion(&wait);
315 
316 	scpnt->SCp.ptr = NULL;
317 
318 	return 0;
319 }
320 
321 /*
322  * function:	zfcp_scsi_queuecommand
323  *
324  * purpose:	enqueues a SCSI command to the specified target device
325  *
326  * returns:	0 - success, SCSI command enqueued
327  *		!0 - failure
328  */
329 int
330 zfcp_scsi_queuecommand(struct scsi_cmnd *scpnt,
331 		       void (*done) (struct scsi_cmnd *))
332 {
333 	struct zfcp_unit *unit;
334 	struct zfcp_adapter *adapter;
335 
336 	/* reset the status for this request */
337 	scpnt->result = 0;
338 	scpnt->host_scribble = NULL;
339 	scpnt->scsi_done = done;
340 
341 	/*
342 	 * figure out adapter and target device
343 	 * (stored there by zfcp_scsi_slave_alloc)
344 	 */
345 	adapter = (struct zfcp_adapter *) scpnt->device->host->hostdata[0];
346 	unit = (struct zfcp_unit *) scpnt->device->hostdata;
347 
348 	return zfcp_scsi_command_async(adapter, unit, scpnt, NULL);
349 }
350 
351 static struct zfcp_unit *
352 zfcp_unit_lookup(struct zfcp_adapter *adapter, int channel, unsigned int id,
353 		 unsigned int lun)
354 {
355 	struct zfcp_port *port;
356 	struct zfcp_unit *unit, *retval = NULL;
357 
358 	list_for_each_entry(port, &adapter->port_list_head, list) {
359 		if (!port->rport || (id != port->rport->scsi_target_id))
360 			continue;
361 		list_for_each_entry(unit, &port->unit_list_head, list) {
362 			if (lun == unit->scsi_lun) {
363 				retval = unit;
364 				goto out;
365 			}
366 		}
367 	}
368  out:
369 	return retval;
370 }
371 
372 /**
373  * zfcp_scsi_eh_abort_handler - abort the specified SCSI command
374  * @scpnt: pointer to scsi_cmnd to be aborted
375  * Return: SUCCESS - command has been aborted and cleaned up in internal
376  *          bookkeeping, SCSI stack won't be called for aborted command
377  *         FAILED - otherwise
378  *
379  * We do not need to care for a SCSI command which completes normally
380  * but late during this abort routine runs.  We are allowed to return
381  * late commands to the SCSI stack.  It tracks the state of commands and
382  * will handle late commands.  (Usually, the normal completion of late
383  * commands is ignored with respect to the running abort operation.)
384  */
385 int
386 zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
387 {
388  	struct Scsi_Host *scsi_host;
389  	struct zfcp_adapter *adapter;
390 	struct zfcp_unit *unit;
391 	int retval = SUCCESS;
392 	struct zfcp_fsf_req *new_fsf_req = NULL;
393 	struct zfcp_fsf_req *old_fsf_req;
394 	unsigned long flags;
395 
396 	scsi_host = scpnt->device->host;
397 	adapter = (struct zfcp_adapter *) scsi_host->hostdata[0];
398 	unit = (struct zfcp_unit *) scpnt->device->hostdata;
399 
400 	ZFCP_LOG_INFO("aborting scsi_cmnd=%p on adapter %s\n",
401 		      scpnt, zfcp_get_busid_by_adapter(adapter));
402 
403 	/* avoid race condition between late normal completion and abort */
404 	write_lock_irqsave(&adapter->abort_lock, flags);
405 
406 	/*
407 	 * Check whether command has just completed and can not be aborted.
408 	 * Even if the command has just been completed late, we can access
409 	 * scpnt since the SCSI stack does not release it at least until
410 	 * this routine returns. (scpnt is parameter passed to this routine
411 	 * and must not disappear during abort even on late completion.)
412 	 */
413 	old_fsf_req = (struct zfcp_fsf_req *) scpnt->host_scribble;
414 	if (!old_fsf_req) {
415 		write_unlock_irqrestore(&adapter->abort_lock, flags);
416 		zfcp_scsi_dbf_event_abort("lte1", adapter, scpnt, NULL, NULL);
417 		retval = SUCCESS;
418 		goto out;
419 	}
420 	old_fsf_req->data = 0;
421 	old_fsf_req->status |= ZFCP_STATUS_FSFREQ_ABORTING;
422 
423 	/* don't access old_fsf_req after releasing the abort_lock */
424 	write_unlock_irqrestore(&adapter->abort_lock, flags);
425 	/* call FSF routine which does the abort */
426 	new_fsf_req = zfcp_fsf_abort_fcp_command((unsigned long) old_fsf_req,
427 						 adapter, unit, 0);
428 	if (!new_fsf_req) {
429 		ZFCP_LOG_INFO("error: initiation of Abort FCP Cmnd failed\n");
430 		zfcp_scsi_dbf_event_abort("nres", adapter, scpnt, NULL,
431 					  old_fsf_req);
432 		retval = FAILED;
433 		goto out;
434 	}
435 
436 	/* wait for completion of abort */
437 	__wait_event(new_fsf_req->completion_wq,
438 		     new_fsf_req->status & ZFCP_STATUS_FSFREQ_COMPLETED);
439 
440 	/* status should be valid since signals were not permitted */
441 	if (new_fsf_req->status & ZFCP_STATUS_FSFREQ_ABORTSUCCEEDED) {
442 		zfcp_scsi_dbf_event_abort("okay", adapter, scpnt, new_fsf_req,
443 					  NULL);
444 		retval = SUCCESS;
445 	} else if (new_fsf_req->status & ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED) {
446 		zfcp_scsi_dbf_event_abort("lte2", adapter, scpnt, new_fsf_req,
447 					  NULL);
448 		retval = SUCCESS;
449 	} else {
450 		zfcp_scsi_dbf_event_abort("fail", adapter, scpnt, new_fsf_req,
451 					  NULL);
452 		retval = FAILED;
453 	}
454 	zfcp_fsf_req_free(new_fsf_req);
455  out:
456 	return retval;
457 }
458 
459 int
460 zfcp_scsi_eh_device_reset_handler(struct scsi_cmnd *scpnt)
461 {
462 	int retval;
463 	struct zfcp_unit *unit = (struct zfcp_unit *) scpnt->device->hostdata;
464 
465 	if (!unit) {
466 		ZFCP_LOG_NORMAL("bug: Tried reset for nonexistent unit\n");
467 		retval = SUCCESS;
468 		goto out;
469 	}
470 	ZFCP_LOG_NORMAL("resetting unit 0x%016Lx\n", unit->fcp_lun);
471 
472 	/*
473 	 * If we do not know whether the unit supports 'logical unit reset'
474 	 * then try 'logical unit reset' and proceed with 'target reset'
475 	 * if 'logical unit reset' fails.
476 	 * If the unit is known not to support 'logical unit reset' then
477 	 * skip 'logical unit reset' and try 'target reset' immediately.
478 	 */
479 	if (!atomic_test_mask(ZFCP_STATUS_UNIT_NOTSUPPUNITRESET,
480 			      &unit->status)) {
481 		retval = zfcp_task_management_function(unit,
482 						       FCP_LOGICAL_UNIT_RESET,
483 						       scpnt);
484 		if (retval) {
485 			ZFCP_LOG_DEBUG("unit reset failed (unit=%p)\n", unit);
486 			if (retval == -ENOTSUPP)
487 				atomic_set_mask
488 				    (ZFCP_STATUS_UNIT_NOTSUPPUNITRESET,
489 				     &unit->status);
490 			/* fall through and try 'target reset' next */
491 		} else {
492 			ZFCP_LOG_DEBUG("unit reset succeeded (unit=%p)\n",
493 				       unit);
494 			/* avoid 'target reset' */
495 			retval = SUCCESS;
496 			goto out;
497 		}
498 	}
499 	retval = zfcp_task_management_function(unit, FCP_TARGET_RESET, scpnt);
500 	if (retval) {
501 		ZFCP_LOG_DEBUG("target reset failed (unit=%p)\n", unit);
502 		retval = FAILED;
503 	} else {
504 		ZFCP_LOG_DEBUG("target reset succeeded (unit=%p)\n", unit);
505 		retval = SUCCESS;
506 	}
507  out:
508 	return retval;
509 }
510 
511 static int
512 zfcp_task_management_function(struct zfcp_unit *unit, u8 tm_flags,
513 			      struct scsi_cmnd *scpnt)
514 {
515 	struct zfcp_adapter *adapter = unit->port->adapter;
516 	struct zfcp_fsf_req *fsf_req;
517 	int retval = 0;
518 
519 	/* issue task management function */
520 	fsf_req = zfcp_fsf_send_fcp_command_task_management
521 		(adapter, unit, tm_flags, 0);
522 	if (!fsf_req) {
523 		ZFCP_LOG_INFO("error: creation of task management request "
524 			      "failed for unit 0x%016Lx on port 0x%016Lx on  "
525 			      "adapter %s\n", unit->fcp_lun, unit->port->wwpn,
526 			      zfcp_get_busid_by_adapter(adapter));
527 		zfcp_scsi_dbf_event_devreset("nres", tm_flags, unit, scpnt);
528 		retval = -ENOMEM;
529 		goto out;
530 	}
531 
532 	__wait_event(fsf_req->completion_wq,
533 		     fsf_req->status & ZFCP_STATUS_FSFREQ_COMPLETED);
534 
535 	/*
536 	 * check completion status of task management function
537 	 */
538 	if (fsf_req->status & ZFCP_STATUS_FSFREQ_TMFUNCFAILED) {
539 		zfcp_scsi_dbf_event_devreset("fail", tm_flags, unit, scpnt);
540 		retval = -EIO;
541 	} else if (fsf_req->status & ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP) {
542 		zfcp_scsi_dbf_event_devreset("nsup", tm_flags, unit, scpnt);
543 		retval = -ENOTSUPP;
544 	} else
545 		zfcp_scsi_dbf_event_devreset("okay", tm_flags, unit, scpnt);
546 
547 	zfcp_fsf_req_free(fsf_req);
548  out:
549 	return retval;
550 }
551 
552 /**
553  * zfcp_scsi_eh_bus_reset_handler - reset bus (reopen adapter)
554  */
555 int
556 zfcp_scsi_eh_bus_reset_handler(struct scsi_cmnd *scpnt)
557 {
558 	struct zfcp_unit *unit = (struct zfcp_unit*) scpnt->device->hostdata;
559 	struct zfcp_adapter *adapter = unit->port->adapter;
560 
561 	ZFCP_LOG_NORMAL("bus reset because of problems with "
562 			"unit 0x%016Lx\n", unit->fcp_lun);
563 	zfcp_erp_adapter_reopen(adapter, 0);
564 	zfcp_erp_wait(adapter);
565 
566 	return SUCCESS;
567 }
568 
569 /**
570  * zfcp_scsi_eh_host_reset_handler - reset host (reopen adapter)
571  */
572 int
573 zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
574 {
575 	struct zfcp_unit *unit = (struct zfcp_unit*) scpnt->device->hostdata;
576 	struct zfcp_adapter *adapter = unit->port->adapter;
577 
578 	ZFCP_LOG_NORMAL("host reset because of problems with "
579 			"unit 0x%016Lx\n", unit->fcp_lun);
580 	zfcp_erp_adapter_reopen(adapter, 0);
581 	zfcp_erp_wait(adapter);
582 
583 	return SUCCESS;
584 }
585 
586 int
587 zfcp_adapter_scsi_register(struct zfcp_adapter *adapter)
588 {
589 	int retval = 0;
590 	static unsigned int unique_id = 0;
591 
592 	/* register adapter as SCSI host with mid layer of SCSI stack */
593 	adapter->scsi_host = scsi_host_alloc(&zfcp_data.scsi_host_template,
594 					     sizeof (struct zfcp_adapter *));
595 	if (!adapter->scsi_host) {
596 		ZFCP_LOG_NORMAL("error: registration with SCSI stack failed "
597 				"for adapter %s ",
598 				zfcp_get_busid_by_adapter(adapter));
599 		retval = -EIO;
600 		goto out;
601 	}
602 	ZFCP_LOG_DEBUG("host registered, scsi_host=%p\n", adapter->scsi_host);
603 
604 	/* tell the SCSI stack some characteristics of this adapter */
605 	adapter->scsi_host->max_id = 1;
606 	adapter->scsi_host->max_lun = 1;
607 	adapter->scsi_host->max_channel = 0;
608 	adapter->scsi_host->unique_id = unique_id++;	/* FIXME */
609 	adapter->scsi_host->max_cmd_len = ZFCP_MAX_SCSI_CMND_LENGTH;
610 	adapter->scsi_host->transportt = zfcp_transport_template;
611 
612 	/*
613 	 * save a pointer to our own adapter data structure within
614 	 * hostdata field of SCSI host data structure
615 	 */
616 	adapter->scsi_host->hostdata[0] = (unsigned long) adapter;
617 
618 	if (scsi_add_host(adapter->scsi_host, &adapter->ccw_device->dev)) {
619 		scsi_host_put(adapter->scsi_host);
620 		retval = -EIO;
621 		goto out;
622 	}
623 	atomic_set_mask(ZFCP_STATUS_ADAPTER_REGISTERED, &adapter->status);
624  out:
625 	return retval;
626 }
627 
628 void
629 zfcp_adapter_scsi_unregister(struct zfcp_adapter *adapter)
630 {
631 	struct Scsi_Host *shost;
632 	struct zfcp_port *port;
633 
634 	shost = adapter->scsi_host;
635 	if (!shost)
636 		return;
637 	read_lock_irq(&zfcp_data.config_lock);
638 	list_for_each_entry(port, &adapter->port_list_head, list)
639 		if (port->rport)
640 			port->rport = NULL;
641 	read_unlock_irq(&zfcp_data.config_lock);
642 	fc_remove_host(shost);
643 	scsi_remove_host(shost);
644 	scsi_host_put(shost);
645 	adapter->scsi_host = NULL;
646 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_REGISTERED, &adapter->status);
647 
648 	return;
649 }
650 
651 
652 void
653 zfcp_fsf_start_scsi_er_timer(struct zfcp_adapter *adapter)
654 {
655 	adapter->scsi_er_timer.function = zfcp_fsf_scsi_er_timeout_handler;
656 	adapter->scsi_er_timer.data = (unsigned long) adapter;
657 	adapter->scsi_er_timer.expires = jiffies + ZFCP_SCSI_ER_TIMEOUT;
658 	add_timer(&adapter->scsi_er_timer);
659 }
660 
661 /*
662  * Support functions for FC transport class
663  */
664 static struct fc_host_statistics*
665 zfcp_init_fc_host_stats(struct zfcp_adapter *adapter)
666 {
667 	struct fc_host_statistics *fc_stats;
668 
669 	if (!adapter->fc_stats) {
670 		fc_stats = kmalloc(sizeof(*fc_stats), GFP_KERNEL);
671 		if (!fc_stats)
672 			return NULL;
673 		adapter->fc_stats = fc_stats; /* freed in adater_dequeue */
674 	}
675 	memset(adapter->fc_stats, 0, sizeof(*adapter->fc_stats));
676 	return adapter->fc_stats;
677 }
678 
679 static void
680 zfcp_adjust_fc_host_stats(struct fc_host_statistics *fc_stats,
681 			  struct fsf_qtcb_bottom_port *data,
682 			  struct fsf_qtcb_bottom_port *old)
683 {
684 	fc_stats->seconds_since_last_reset = data->seconds_since_last_reset -
685 		old->seconds_since_last_reset;
686 	fc_stats->tx_frames = data->tx_frames - old->tx_frames;
687 	fc_stats->tx_words = data->tx_words - old->tx_words;
688 	fc_stats->rx_frames = data->rx_frames - old->rx_frames;
689 	fc_stats->rx_words = data->rx_words - old->rx_words;
690 	fc_stats->lip_count = data->lip - old->lip;
691 	fc_stats->nos_count = data->nos - old->nos;
692 	fc_stats->error_frames = data->error_frames - old->error_frames;
693 	fc_stats->dumped_frames = data->dumped_frames - old->dumped_frames;
694 	fc_stats->link_failure_count = data->link_failure - old->link_failure;
695 	fc_stats->loss_of_sync_count = data->loss_of_sync - old->loss_of_sync;
696 	fc_stats->loss_of_signal_count = data->loss_of_signal -
697 		old->loss_of_signal;
698 	fc_stats->prim_seq_protocol_err_count = data->psp_error_counts -
699 		old->psp_error_counts;
700 	fc_stats->invalid_tx_word_count = data->invalid_tx_words -
701 		old->invalid_tx_words;
702 	fc_stats->invalid_crc_count = data->invalid_crcs - old->invalid_crcs;
703 	fc_stats->fcp_input_requests = data->input_requests -
704 		old->input_requests;
705 	fc_stats->fcp_output_requests = data->output_requests -
706 		old->output_requests;
707 	fc_stats->fcp_control_requests = data->control_requests -
708 		old->control_requests;
709 	fc_stats->fcp_input_megabytes = data->input_mb - old->input_mb;
710 	fc_stats->fcp_output_megabytes = data->output_mb - old->output_mb;
711 }
712 
713 static void
714 zfcp_set_fc_host_stats(struct fc_host_statistics *fc_stats,
715 		       struct fsf_qtcb_bottom_port *data)
716 {
717 	fc_stats->seconds_since_last_reset = data->seconds_since_last_reset;
718 	fc_stats->tx_frames = data->tx_frames;
719 	fc_stats->tx_words = data->tx_words;
720 	fc_stats->rx_frames = data->rx_frames;
721 	fc_stats->rx_words = data->rx_words;
722 	fc_stats->lip_count = data->lip;
723 	fc_stats->nos_count = data->nos;
724 	fc_stats->error_frames = data->error_frames;
725 	fc_stats->dumped_frames = data->dumped_frames;
726 	fc_stats->link_failure_count = data->link_failure;
727 	fc_stats->loss_of_sync_count = data->loss_of_sync;
728 	fc_stats->loss_of_signal_count = data->loss_of_signal;
729 	fc_stats->prim_seq_protocol_err_count = data->psp_error_counts;
730 	fc_stats->invalid_tx_word_count = data->invalid_tx_words;
731 	fc_stats->invalid_crc_count = data->invalid_crcs;
732 	fc_stats->fcp_input_requests = data->input_requests;
733 	fc_stats->fcp_output_requests = data->output_requests;
734 	fc_stats->fcp_control_requests = data->control_requests;
735 	fc_stats->fcp_input_megabytes = data->input_mb;
736 	fc_stats->fcp_output_megabytes = data->output_mb;
737 }
738 
739 /**
740  * zfcp_get_fc_host_stats - provide fc_host_statistics for scsi_transport_fc
741  *
742  * assumption: scsi_transport_fc synchronizes calls of
743  *             get_fc_host_stats and reset_fc_host_stats
744  *             (XXX to be checked otherwise introduce locking)
745  */
746 static struct fc_host_statistics *
747 zfcp_get_fc_host_stats(struct Scsi_Host *shost)
748 {
749 	struct zfcp_adapter *adapter;
750 	struct fc_host_statistics *fc_stats;
751 	struct fsf_qtcb_bottom_port *data;
752 	int ret;
753 
754 	adapter = (struct zfcp_adapter *)shost->hostdata[0];
755 	fc_stats = zfcp_init_fc_host_stats(adapter);
756 	if (!fc_stats)
757 		return NULL;
758 
759 	data = kzalloc(sizeof(*data), GFP_KERNEL);
760 	if (!data)
761 		return NULL;
762 
763 	ret = zfcp_fsf_exchange_port_data(NULL, adapter, data);
764 	if (ret) {
765 		kfree(data);
766 		return NULL; /* XXX return zeroed fc_stats? */
767 	}
768 
769 	if (adapter->stats_reset &&
770 	    ((jiffies/HZ - adapter->stats_reset) <
771 	     data->seconds_since_last_reset)) {
772 		zfcp_adjust_fc_host_stats(fc_stats, data,
773 					  adapter->stats_reset_data);
774 	} else
775 		zfcp_set_fc_host_stats(fc_stats, data);
776 
777 	kfree(data);
778 	return fc_stats;
779 }
780 
781 static void
782 zfcp_reset_fc_host_stats(struct Scsi_Host *shost)
783 {
784 	struct zfcp_adapter *adapter;
785 	struct fsf_qtcb_bottom_port *data, *old_data;
786 	int ret;
787 
788 	adapter = (struct zfcp_adapter *)shost->hostdata[0];
789 	data = kzalloc(sizeof(*data), GFP_KERNEL);
790 	if (!data)
791 		return;
792 
793 	ret = zfcp_fsf_exchange_port_data(NULL, adapter, data);
794 	if (ret == 0) {
795 		adapter->stats_reset = jiffies/HZ;
796 		old_data = adapter->stats_reset_data;
797 		adapter->stats_reset_data = data; /* finally freed in
798 						     adater_dequeue */
799 		kfree(old_data);
800 	}
801 }
802 
803 static void zfcp_set_rport_dev_loss_tmo(struct fc_rport *rport, u32 timeout)
804 {
805 	rport->dev_loss_tmo = timeout;
806 }
807 
808 struct fc_function_template zfcp_transport_functions = {
809 	.show_starget_port_id = 1,
810 	.show_starget_port_name = 1,
811 	.show_starget_node_name = 1,
812 	.show_rport_supported_classes = 1,
813 	.show_rport_maxframe_size = 1,
814 	.show_rport_dev_loss_tmo = 1,
815 	.show_host_node_name = 1,
816 	.show_host_port_name = 1,
817 	.show_host_permanent_port_name = 1,
818 	.show_host_supported_classes = 1,
819 	.show_host_supported_speeds = 1,
820 	.show_host_maxframe_size = 1,
821 	.show_host_serial_number = 1,
822 	.get_fc_host_stats = zfcp_get_fc_host_stats,
823 	.reset_fc_host_stats = zfcp_reset_fc_host_stats,
824 	.set_rport_dev_loss_tmo = zfcp_set_rport_dev_loss_tmo,
825 	/* no functions registered for following dynamic attributes but
826 	   directly set by LLDD */
827 	.show_host_port_type = 1,
828 	.show_host_speed = 1,
829 	.show_host_port_id = 1,
830 };
831 
832 /**
833  * ZFCP_DEFINE_SCSI_ATTR
834  * @_name:   name of show attribute
835  * @_format: format string
836  * @_value:  value to print
837  *
838  * Generates attribute for a unit.
839  */
840 #define ZFCP_DEFINE_SCSI_ATTR(_name, _format, _value)                    \
841 static ssize_t zfcp_sysfs_scsi_##_name##_show(struct device *dev, struct device_attribute *attr,        \
842                                               char *buf)                 \
843 {                                                                        \
844         struct scsi_device *sdev;                                        \
845         struct zfcp_unit *unit;                                          \
846                                                                          \
847         sdev = to_scsi_device(dev);                                      \
848         unit = sdev->hostdata;                                           \
849         return sprintf(buf, _format, _value);                            \
850 }                                                                        \
851                                                                          \
852 static DEVICE_ATTR(_name, S_IRUGO, zfcp_sysfs_scsi_##_name##_show, NULL);
853 
854 ZFCP_DEFINE_SCSI_ATTR(hba_id, "%s\n", zfcp_get_busid_by_unit(unit));
855 ZFCP_DEFINE_SCSI_ATTR(wwpn, "0x%016llx\n", unit->port->wwpn);
856 ZFCP_DEFINE_SCSI_ATTR(fcp_lun, "0x%016llx\n", unit->fcp_lun);
857 
858 static struct device_attribute *zfcp_sysfs_sdev_attrs[] = {
859 	&dev_attr_fcp_lun,
860 	&dev_attr_wwpn,
861 	&dev_attr_hba_id,
862 	NULL
863 };
864 
865 #undef ZFCP_LOG_AREA
866