xref: /openbmc/linux/drivers/s390/scsi/zfcp_erp.c (revision 711aab1d)
1 /*
2  * zfcp device driver
3  *
4  * Error Recovery Procedures (ERP).
5  *
6  * Copyright IBM Corp. 2002, 2016
7  */
8 
9 #define KMSG_COMPONENT "zfcp"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11 
12 #include <linux/kthread.h>
13 #include "zfcp_ext.h"
14 #include "zfcp_reqlist.h"
15 
16 #define ZFCP_MAX_ERPS                   3
17 
18 enum zfcp_erp_act_flags {
19 	ZFCP_STATUS_ERP_TIMEDOUT	= 0x10000000,
20 	ZFCP_STATUS_ERP_CLOSE_ONLY	= 0x01000000,
21 	ZFCP_STATUS_ERP_DISMISSING	= 0x00100000,
22 	ZFCP_STATUS_ERP_DISMISSED	= 0x00200000,
23 	ZFCP_STATUS_ERP_LOWMEM		= 0x00400000,
24 	ZFCP_STATUS_ERP_NO_REF		= 0x00800000,
25 };
26 
27 enum zfcp_erp_steps {
28 	ZFCP_ERP_STEP_UNINITIALIZED	= 0x0000,
29 	ZFCP_ERP_STEP_FSF_XCONFIG	= 0x0001,
30 	ZFCP_ERP_STEP_PHYS_PORT_CLOSING	= 0x0010,
31 	ZFCP_ERP_STEP_PORT_CLOSING	= 0x0100,
32 	ZFCP_ERP_STEP_PORT_OPENING	= 0x0800,
33 	ZFCP_ERP_STEP_LUN_CLOSING	= 0x1000,
34 	ZFCP_ERP_STEP_LUN_OPENING	= 0x2000,
35 };
36 
37 enum zfcp_erp_act_type {
38 	ZFCP_ERP_ACTION_REOPEN_LUN         = 1,
39 	ZFCP_ERP_ACTION_REOPEN_PORT	   = 2,
40 	ZFCP_ERP_ACTION_REOPEN_PORT_FORCED = 3,
41 	ZFCP_ERP_ACTION_REOPEN_ADAPTER     = 4,
42 };
43 
44 enum zfcp_erp_act_state {
45 	ZFCP_ERP_ACTION_RUNNING = 1,
46 	ZFCP_ERP_ACTION_READY   = 2,
47 };
48 
49 enum zfcp_erp_act_result {
50 	ZFCP_ERP_SUCCEEDED = 0,
51 	ZFCP_ERP_FAILED    = 1,
52 	ZFCP_ERP_CONTINUES = 2,
53 	ZFCP_ERP_EXIT      = 3,
54 	ZFCP_ERP_DISMISSED = 4,
55 	ZFCP_ERP_NOMEM     = 5,
56 };
57 
58 static void zfcp_erp_adapter_block(struct zfcp_adapter *adapter, int mask)
59 {
60 	zfcp_erp_clear_adapter_status(adapter,
61 				       ZFCP_STATUS_COMMON_UNBLOCKED | mask);
62 }
63 
64 static int zfcp_erp_action_exists(struct zfcp_erp_action *act)
65 {
66 	struct zfcp_erp_action *curr_act;
67 
68 	list_for_each_entry(curr_act, &act->adapter->erp_running_head, list)
69 		if (act == curr_act)
70 			return ZFCP_ERP_ACTION_RUNNING;
71 	return 0;
72 }
73 
74 static void zfcp_erp_action_ready(struct zfcp_erp_action *act)
75 {
76 	struct zfcp_adapter *adapter = act->adapter;
77 
78 	list_move(&act->list, &act->adapter->erp_ready_head);
79 	zfcp_dbf_rec_run("erardy1", act);
80 	wake_up(&adapter->erp_ready_wq);
81 	zfcp_dbf_rec_run("erardy2", act);
82 }
83 
84 static void zfcp_erp_action_dismiss(struct zfcp_erp_action *act)
85 {
86 	act->status |= ZFCP_STATUS_ERP_DISMISSED;
87 	if (zfcp_erp_action_exists(act) == ZFCP_ERP_ACTION_RUNNING)
88 		zfcp_erp_action_ready(act);
89 }
90 
91 static void zfcp_erp_action_dismiss_lun(struct scsi_device *sdev)
92 {
93 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
94 
95 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
96 		zfcp_erp_action_dismiss(&zfcp_sdev->erp_action);
97 }
98 
99 static void zfcp_erp_action_dismiss_port(struct zfcp_port *port)
100 {
101 	struct scsi_device *sdev;
102 
103 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
104 		zfcp_erp_action_dismiss(&port->erp_action);
105 	else {
106 		spin_lock(port->adapter->scsi_host->host_lock);
107 		__shost_for_each_device(sdev, port->adapter->scsi_host)
108 			if (sdev_to_zfcp(sdev)->port == port)
109 				zfcp_erp_action_dismiss_lun(sdev);
110 		spin_unlock(port->adapter->scsi_host->host_lock);
111 	}
112 }
113 
114 static void zfcp_erp_action_dismiss_adapter(struct zfcp_adapter *adapter)
115 {
116 	struct zfcp_port *port;
117 
118 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
119 		zfcp_erp_action_dismiss(&adapter->erp_action);
120 	else {
121 		read_lock(&adapter->port_list_lock);
122 		list_for_each_entry(port, &adapter->port_list, list)
123 		    zfcp_erp_action_dismiss_port(port);
124 		read_unlock(&adapter->port_list_lock);
125 	}
126 }
127 
128 static int zfcp_erp_required_act(int want, struct zfcp_adapter *adapter,
129 				 struct zfcp_port *port,
130 				 struct scsi_device *sdev)
131 {
132 	int need = want;
133 	int l_status, p_status, a_status;
134 	struct zfcp_scsi_dev *zfcp_sdev;
135 
136 	switch (want) {
137 	case ZFCP_ERP_ACTION_REOPEN_LUN:
138 		zfcp_sdev = sdev_to_zfcp(sdev);
139 		l_status = atomic_read(&zfcp_sdev->status);
140 		if (l_status & ZFCP_STATUS_COMMON_ERP_INUSE)
141 			return 0;
142 		p_status = atomic_read(&port->status);
143 		if (!(p_status & ZFCP_STATUS_COMMON_RUNNING) ||
144 		      p_status & ZFCP_STATUS_COMMON_ERP_FAILED)
145 			return 0;
146 		if (!(p_status & ZFCP_STATUS_COMMON_UNBLOCKED))
147 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
148 		/* fall through */
149 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
150 		p_status = atomic_read(&port->status);
151 		if (!(p_status & ZFCP_STATUS_COMMON_OPEN))
152 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
153 		/* fall through */
154 	case ZFCP_ERP_ACTION_REOPEN_PORT:
155 		p_status = atomic_read(&port->status);
156 		if (p_status & ZFCP_STATUS_COMMON_ERP_INUSE)
157 			return 0;
158 		a_status = atomic_read(&adapter->status);
159 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) ||
160 		      a_status & ZFCP_STATUS_COMMON_ERP_FAILED)
161 			return 0;
162 		if (p_status & ZFCP_STATUS_COMMON_NOESC)
163 			return need;
164 		if (!(a_status & ZFCP_STATUS_COMMON_UNBLOCKED))
165 			need = ZFCP_ERP_ACTION_REOPEN_ADAPTER;
166 		/* fall through */
167 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
168 		a_status = atomic_read(&adapter->status);
169 		if (a_status & ZFCP_STATUS_COMMON_ERP_INUSE)
170 			return 0;
171 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) &&
172 		    !(a_status & ZFCP_STATUS_COMMON_OPEN))
173 			return 0; /* shutdown requested for closed adapter */
174 	}
175 
176 	return need;
177 }
178 
179 static struct zfcp_erp_action *zfcp_erp_setup_act(int need, u32 act_status,
180 						  struct zfcp_adapter *adapter,
181 						  struct zfcp_port *port,
182 						  struct scsi_device *sdev)
183 {
184 	struct zfcp_erp_action *erp_action;
185 	struct zfcp_scsi_dev *zfcp_sdev;
186 
187 	switch (need) {
188 	case ZFCP_ERP_ACTION_REOPEN_LUN:
189 		zfcp_sdev = sdev_to_zfcp(sdev);
190 		if (!(act_status & ZFCP_STATUS_ERP_NO_REF))
191 			if (scsi_device_get(sdev))
192 				return NULL;
193 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE,
194 				&zfcp_sdev->status);
195 		erp_action = &zfcp_sdev->erp_action;
196 		memset(erp_action, 0, sizeof(struct zfcp_erp_action));
197 		erp_action->port = port;
198 		erp_action->sdev = sdev;
199 		if (!(atomic_read(&zfcp_sdev->status) &
200 		      ZFCP_STATUS_COMMON_RUNNING))
201 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
202 		break;
203 
204 	case ZFCP_ERP_ACTION_REOPEN_PORT:
205 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
206 		if (!get_device(&port->dev))
207 			return NULL;
208 		zfcp_erp_action_dismiss_port(port);
209 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status);
210 		erp_action = &port->erp_action;
211 		memset(erp_action, 0, sizeof(struct zfcp_erp_action));
212 		erp_action->port = port;
213 		if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_RUNNING))
214 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
215 		break;
216 
217 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
218 		kref_get(&adapter->ref);
219 		zfcp_erp_action_dismiss_adapter(adapter);
220 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status);
221 		erp_action = &adapter->erp_action;
222 		memset(erp_action, 0, sizeof(struct zfcp_erp_action));
223 		if (!(atomic_read(&adapter->status) &
224 		      ZFCP_STATUS_COMMON_RUNNING))
225 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
226 		break;
227 
228 	default:
229 		return NULL;
230 	}
231 
232 	erp_action->adapter = adapter;
233 	erp_action->action = need;
234 	erp_action->status = act_status;
235 
236 	return erp_action;
237 }
238 
239 static int zfcp_erp_action_enqueue(int want, struct zfcp_adapter *adapter,
240 				   struct zfcp_port *port,
241 				   struct scsi_device *sdev,
242 				   char *id, u32 act_status)
243 {
244 	int retval = 1, need;
245 	struct zfcp_erp_action *act;
246 
247 	if (!adapter->erp_thread)
248 		return -EIO;
249 
250 	need = zfcp_erp_required_act(want, adapter, port, sdev);
251 	if (!need)
252 		goto out;
253 
254 	act = zfcp_erp_setup_act(need, act_status, adapter, port, sdev);
255 	if (!act)
256 		goto out;
257 	atomic_or(ZFCP_STATUS_ADAPTER_ERP_PENDING, &adapter->status);
258 	++adapter->erp_total_count;
259 	list_add_tail(&act->list, &adapter->erp_ready_head);
260 	wake_up(&adapter->erp_ready_wq);
261 	retval = 0;
262  out:
263 	zfcp_dbf_rec_trig(id, adapter, port, sdev, want, need);
264 	return retval;
265 }
266 
267 static int _zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter,
268 				    int clear_mask, char *id)
269 {
270 	zfcp_erp_adapter_block(adapter, clear_mask);
271 	zfcp_scsi_schedule_rports_block(adapter);
272 
273 	/* ensure propagation of failed status to new devices */
274 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
275 		zfcp_erp_set_adapter_status(adapter,
276 					    ZFCP_STATUS_COMMON_ERP_FAILED);
277 		return -EIO;
278 	}
279 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER,
280 				       adapter, NULL, NULL, id, 0);
281 }
282 
283 /**
284  * zfcp_erp_adapter_reopen - Reopen adapter.
285  * @adapter: Adapter to reopen.
286  * @clear: Status flags to clear.
287  * @id: Id for debug trace event.
288  */
289 void zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter, int clear, char *id)
290 {
291 	unsigned long flags;
292 
293 	zfcp_erp_adapter_block(adapter, clear);
294 	zfcp_scsi_schedule_rports_block(adapter);
295 
296 	write_lock_irqsave(&adapter->erp_lock, flags);
297 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
298 		zfcp_erp_set_adapter_status(adapter,
299 					    ZFCP_STATUS_COMMON_ERP_FAILED);
300 	else
301 		zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER, adapter,
302 					NULL, NULL, id, 0);
303 	write_unlock_irqrestore(&adapter->erp_lock, flags);
304 }
305 
306 /**
307  * zfcp_erp_adapter_shutdown - Shutdown adapter.
308  * @adapter: Adapter to shut down.
309  * @clear: Status flags to clear.
310  * @id: Id for debug trace event.
311  */
312 void zfcp_erp_adapter_shutdown(struct zfcp_adapter *adapter, int clear,
313 			       char *id)
314 {
315 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
316 	zfcp_erp_adapter_reopen(adapter, clear | flags, id);
317 }
318 
319 /**
320  * zfcp_erp_port_shutdown - Shutdown port
321  * @port: Port to shut down.
322  * @clear: Status flags to clear.
323  * @id: Id for debug trace event.
324  */
325 void zfcp_erp_port_shutdown(struct zfcp_port *port, int clear, char *id)
326 {
327 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
328 	zfcp_erp_port_reopen(port, clear | flags, id);
329 }
330 
331 static void zfcp_erp_port_block(struct zfcp_port *port, int clear)
332 {
333 	zfcp_erp_clear_port_status(port,
334 				    ZFCP_STATUS_COMMON_UNBLOCKED | clear);
335 }
336 
337 static void _zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear,
338 					 char *id)
339 {
340 	zfcp_erp_port_block(port, clear);
341 	zfcp_scsi_schedule_rport_block(port);
342 
343 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
344 		return;
345 
346 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
347 				port->adapter, port, NULL, id, 0);
348 }
349 
350 /**
351  * zfcp_erp_port_forced_reopen - Forced close of port and open again
352  * @port: Port to force close and to reopen.
353  * @clear: Status flags to clear.
354  * @id: Id for debug trace event.
355  */
356 void zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear, char *id)
357 {
358 	unsigned long flags;
359 	struct zfcp_adapter *adapter = port->adapter;
360 
361 	write_lock_irqsave(&adapter->erp_lock, flags);
362 	_zfcp_erp_port_forced_reopen(port, clear, id);
363 	write_unlock_irqrestore(&adapter->erp_lock, flags);
364 }
365 
366 static int _zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id)
367 {
368 	zfcp_erp_port_block(port, clear);
369 	zfcp_scsi_schedule_rport_block(port);
370 
371 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
372 		/* ensure propagation of failed status to new devices */
373 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
374 		return -EIO;
375 	}
376 
377 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT,
378 				       port->adapter, port, NULL, id, 0);
379 }
380 
381 /**
382  * zfcp_erp_port_reopen - trigger remote port recovery
383  * @port: port to recover
384  * @clear_mask: flags in port status to be cleared
385  * @id: Id for debug trace event.
386  *
387  * Returns 0 if recovery has been triggered, < 0 if not.
388  */
389 int zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id)
390 {
391 	int retval;
392 	unsigned long flags;
393 	struct zfcp_adapter *adapter = port->adapter;
394 
395 	write_lock_irqsave(&adapter->erp_lock, flags);
396 	retval = _zfcp_erp_port_reopen(port, clear, id);
397 	write_unlock_irqrestore(&adapter->erp_lock, flags);
398 
399 	return retval;
400 }
401 
402 static void zfcp_erp_lun_block(struct scsi_device *sdev, int clear_mask)
403 {
404 	zfcp_erp_clear_lun_status(sdev,
405 				  ZFCP_STATUS_COMMON_UNBLOCKED | clear_mask);
406 }
407 
408 static void _zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id,
409 				 u32 act_status)
410 {
411 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
412 	struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
413 
414 	zfcp_erp_lun_block(sdev, clear);
415 
416 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
417 		return;
418 
419 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_LUN, adapter,
420 				zfcp_sdev->port, sdev, id, act_status);
421 }
422 
423 /**
424  * zfcp_erp_lun_reopen - initiate reopen of a LUN
425  * @sdev: SCSI device / LUN to be reopened
426  * @clear_mask: specifies flags in LUN status to be cleared
427  * @id: Id for debug trace event.
428  *
429  * Return: 0 on success, < 0 on error
430  */
431 void zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id)
432 {
433 	unsigned long flags;
434 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
435 	struct zfcp_port *port = zfcp_sdev->port;
436 	struct zfcp_adapter *adapter = port->adapter;
437 
438 	write_lock_irqsave(&adapter->erp_lock, flags);
439 	_zfcp_erp_lun_reopen(sdev, clear, id, 0);
440 	write_unlock_irqrestore(&adapter->erp_lock, flags);
441 }
442 
443 /**
444  * zfcp_erp_lun_shutdown - Shutdown LUN
445  * @sdev: SCSI device / LUN to shut down.
446  * @clear: Status flags to clear.
447  * @id: Id for debug trace event.
448  */
449 void zfcp_erp_lun_shutdown(struct scsi_device *sdev, int clear, char *id)
450 {
451 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
452 	zfcp_erp_lun_reopen(sdev, clear | flags, id);
453 }
454 
455 /**
456  * zfcp_erp_lun_shutdown_wait - Shutdown LUN and wait for erp completion
457  * @sdev: SCSI device / LUN to shut down.
458  * @id: Id for debug trace event.
459  *
460  * Do not acquire a reference for the LUN when creating the ERP
461  * action. It is safe, because this function waits for the ERP to
462  * complete first. This allows to shutdown the LUN, even when the SCSI
463  * device is in the state SDEV_DEL when scsi_device_get will fail.
464  */
465 void zfcp_erp_lun_shutdown_wait(struct scsi_device *sdev, char *id)
466 {
467 	unsigned long flags;
468 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
469 	struct zfcp_port *port = zfcp_sdev->port;
470 	struct zfcp_adapter *adapter = port->adapter;
471 	int clear = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
472 
473 	write_lock_irqsave(&adapter->erp_lock, flags);
474 	_zfcp_erp_lun_reopen(sdev, clear, id, ZFCP_STATUS_ERP_NO_REF);
475 	write_unlock_irqrestore(&adapter->erp_lock, flags);
476 
477 	zfcp_erp_wait(adapter);
478 }
479 
480 static int status_change_set(unsigned long mask, atomic_t *status)
481 {
482 	return (atomic_read(status) ^ mask) & mask;
483 }
484 
485 static void zfcp_erp_adapter_unblock(struct zfcp_adapter *adapter)
486 {
487 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status))
488 		zfcp_dbf_rec_run("eraubl1", &adapter->erp_action);
489 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status);
490 }
491 
492 static void zfcp_erp_port_unblock(struct zfcp_port *port)
493 {
494 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status))
495 		zfcp_dbf_rec_run("erpubl1", &port->erp_action);
496 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status);
497 }
498 
499 static void zfcp_erp_lun_unblock(struct scsi_device *sdev)
500 {
501 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
502 
503 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status))
504 		zfcp_dbf_rec_run("erlubl1", &sdev_to_zfcp(sdev)->erp_action);
505 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status);
506 }
507 
508 static void zfcp_erp_action_to_running(struct zfcp_erp_action *erp_action)
509 {
510 	list_move(&erp_action->list, &erp_action->adapter->erp_running_head);
511 	zfcp_dbf_rec_run("erator1", erp_action);
512 }
513 
514 static void zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *act)
515 {
516 	struct zfcp_adapter *adapter = act->adapter;
517 	struct zfcp_fsf_req *req;
518 
519 	if (!act->fsf_req_id)
520 		return;
521 
522 	spin_lock(&adapter->req_list->lock);
523 	req = _zfcp_reqlist_find(adapter->req_list, act->fsf_req_id);
524 	if (req && req->erp_action == act) {
525 		if (act->status & (ZFCP_STATUS_ERP_DISMISSED |
526 				   ZFCP_STATUS_ERP_TIMEDOUT)) {
527 			req->status |= ZFCP_STATUS_FSFREQ_DISMISSED;
528 			zfcp_dbf_rec_run("erscf_1", act);
529 			req->erp_action = NULL;
530 		}
531 		if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
532 			zfcp_dbf_rec_run("erscf_2", act);
533 		if (req->status & ZFCP_STATUS_FSFREQ_DISMISSED)
534 			act->fsf_req_id = 0;
535 	} else
536 		act->fsf_req_id = 0;
537 	spin_unlock(&adapter->req_list->lock);
538 }
539 
540 /**
541  * zfcp_erp_notify - Trigger ERP action.
542  * @erp_action: ERP action to continue.
543  * @set_mask: ERP action status flags to set.
544  */
545 void zfcp_erp_notify(struct zfcp_erp_action *erp_action, unsigned long set_mask)
546 {
547 	struct zfcp_adapter *adapter = erp_action->adapter;
548 	unsigned long flags;
549 
550 	write_lock_irqsave(&adapter->erp_lock, flags);
551 	if (zfcp_erp_action_exists(erp_action) == ZFCP_ERP_ACTION_RUNNING) {
552 		erp_action->status |= set_mask;
553 		zfcp_erp_action_ready(erp_action);
554 	}
555 	write_unlock_irqrestore(&adapter->erp_lock, flags);
556 }
557 
558 /**
559  * zfcp_erp_timeout_handler - Trigger ERP action from timed out ERP request
560  * @data: ERP action (from timer data)
561  */
562 void zfcp_erp_timeout_handler(unsigned long data)
563 {
564 	struct zfcp_erp_action *act = (struct zfcp_erp_action *) data;
565 	zfcp_erp_notify(act, ZFCP_STATUS_ERP_TIMEDOUT);
566 }
567 
568 static void zfcp_erp_memwait_handler(unsigned long data)
569 {
570 	zfcp_erp_notify((struct zfcp_erp_action *)data, 0);
571 }
572 
573 static void zfcp_erp_strategy_memwait(struct zfcp_erp_action *erp_action)
574 {
575 	setup_timer(&erp_action->timer, zfcp_erp_memwait_handler,
576 		    (unsigned long) erp_action);
577 	erp_action->timer.expires = jiffies + HZ;
578 	add_timer(&erp_action->timer);
579 }
580 
581 static void _zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter,
582 				      int clear, char *id)
583 {
584 	struct zfcp_port *port;
585 
586 	read_lock(&adapter->port_list_lock);
587 	list_for_each_entry(port, &adapter->port_list, list)
588 		_zfcp_erp_port_reopen(port, clear, id);
589 	read_unlock(&adapter->port_list_lock);
590 }
591 
592 static void _zfcp_erp_lun_reopen_all(struct zfcp_port *port, int clear,
593 				     char *id)
594 {
595 	struct scsi_device *sdev;
596 
597 	spin_lock(port->adapter->scsi_host->host_lock);
598 	__shost_for_each_device(sdev, port->adapter->scsi_host)
599 		if (sdev_to_zfcp(sdev)->port == port)
600 			_zfcp_erp_lun_reopen(sdev, clear, id, 0);
601 	spin_unlock(port->adapter->scsi_host->host_lock);
602 }
603 
604 static void zfcp_erp_strategy_followup_failed(struct zfcp_erp_action *act)
605 {
606 	switch (act->action) {
607 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
608 		_zfcp_erp_adapter_reopen(act->adapter, 0, "ersff_1");
609 		break;
610 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
611 		_zfcp_erp_port_forced_reopen(act->port, 0, "ersff_2");
612 		break;
613 	case ZFCP_ERP_ACTION_REOPEN_PORT:
614 		_zfcp_erp_port_reopen(act->port, 0, "ersff_3");
615 		break;
616 	case ZFCP_ERP_ACTION_REOPEN_LUN:
617 		_zfcp_erp_lun_reopen(act->sdev, 0, "ersff_4", 0);
618 		break;
619 	}
620 }
621 
622 static void zfcp_erp_strategy_followup_success(struct zfcp_erp_action *act)
623 {
624 	switch (act->action) {
625 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
626 		_zfcp_erp_port_reopen_all(act->adapter, 0, "ersfs_1");
627 		break;
628 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
629 		_zfcp_erp_port_reopen(act->port, 0, "ersfs_2");
630 		break;
631 	case ZFCP_ERP_ACTION_REOPEN_PORT:
632 		_zfcp_erp_lun_reopen_all(act->port, 0, "ersfs_3");
633 		break;
634 	}
635 }
636 
637 static void zfcp_erp_wakeup(struct zfcp_adapter *adapter)
638 {
639 	unsigned long flags;
640 
641 	read_lock_irqsave(&adapter->erp_lock, flags);
642 	if (list_empty(&adapter->erp_ready_head) &&
643 	    list_empty(&adapter->erp_running_head)) {
644 			atomic_andnot(ZFCP_STATUS_ADAPTER_ERP_PENDING,
645 					  &adapter->status);
646 			wake_up(&adapter->erp_done_wqh);
647 	}
648 	read_unlock_irqrestore(&adapter->erp_lock, flags);
649 }
650 
651 static void zfcp_erp_enqueue_ptp_port(struct zfcp_adapter *adapter)
652 {
653 	struct zfcp_port *port;
654 	port = zfcp_port_enqueue(adapter, adapter->peer_wwpn, 0,
655 				 adapter->peer_d_id);
656 	if (IS_ERR(port)) /* error or port already attached */
657 		return;
658 	_zfcp_erp_port_reopen(port, 0, "ereptp1");
659 }
660 
661 static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
662 {
663 	int retries;
664 	int sleep = 1;
665 	struct zfcp_adapter *adapter = erp_action->adapter;
666 
667 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
668 
669 	for (retries = 7; retries; retries--) {
670 		atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
671 				  &adapter->status);
672 		write_lock_irq(&adapter->erp_lock);
673 		zfcp_erp_action_to_running(erp_action);
674 		write_unlock_irq(&adapter->erp_lock);
675 		if (zfcp_fsf_exchange_config_data(erp_action)) {
676 			atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
677 					  &adapter->status);
678 			return ZFCP_ERP_FAILED;
679 		}
680 
681 		wait_event(adapter->erp_ready_wq,
682 			   !list_empty(&adapter->erp_ready_head));
683 		if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
684 			break;
685 
686 		if (!(atomic_read(&adapter->status) &
687 		      ZFCP_STATUS_ADAPTER_HOST_CON_INIT))
688 			break;
689 
690 		ssleep(sleep);
691 		sleep *= 2;
692 	}
693 
694 	atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
695 			  &adapter->status);
696 
697 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
698 		return ZFCP_ERP_FAILED;
699 
700 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
701 		zfcp_erp_enqueue_ptp_port(adapter);
702 
703 	return ZFCP_ERP_SUCCEEDED;
704 }
705 
706 static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
707 {
708 	int ret;
709 	struct zfcp_adapter *adapter = act->adapter;
710 
711 	write_lock_irq(&adapter->erp_lock);
712 	zfcp_erp_action_to_running(act);
713 	write_unlock_irq(&adapter->erp_lock);
714 
715 	ret = zfcp_fsf_exchange_port_data(act);
716 	if (ret == -EOPNOTSUPP)
717 		return ZFCP_ERP_SUCCEEDED;
718 	if (ret)
719 		return ZFCP_ERP_FAILED;
720 
721 	zfcp_dbf_rec_run("erasox1", act);
722 	wait_event(adapter->erp_ready_wq,
723 		   !list_empty(&adapter->erp_ready_head));
724 	zfcp_dbf_rec_run("erasox2", act);
725 	if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
726 		return ZFCP_ERP_FAILED;
727 
728 	return ZFCP_ERP_SUCCEEDED;
729 }
730 
731 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
732 {
733 	if (zfcp_erp_adapter_strat_fsf_xconf(act) == ZFCP_ERP_FAILED)
734 		return ZFCP_ERP_FAILED;
735 
736 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
737 		return ZFCP_ERP_FAILED;
738 
739 	if (mempool_resize(act->adapter->pool.sr_data,
740 			   act->adapter->stat_read_buf_num))
741 		return ZFCP_ERP_FAILED;
742 
743 	if (mempool_resize(act->adapter->pool.status_read_req,
744 			   act->adapter->stat_read_buf_num))
745 		return ZFCP_ERP_FAILED;
746 
747 	atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
748 	if (zfcp_status_read_refill(act->adapter))
749 		return ZFCP_ERP_FAILED;
750 
751 	return ZFCP_ERP_SUCCEEDED;
752 }
753 
754 static void zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *act)
755 {
756 	struct zfcp_adapter *adapter = act->adapter;
757 
758 	/* close queues to ensure that buffers are not accessed by adapter */
759 	zfcp_qdio_close(adapter->qdio);
760 	zfcp_fsf_req_dismiss_all(adapter);
761 	adapter->fsf_req_seq_no = 0;
762 	zfcp_fc_wka_ports_force_offline(adapter->gs);
763 	/* all ports and LUNs are closed */
764 	zfcp_erp_clear_adapter_status(adapter, ZFCP_STATUS_COMMON_OPEN);
765 
766 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
767 			  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
768 }
769 
770 static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *act)
771 {
772 	struct zfcp_adapter *adapter = act->adapter;
773 
774 	if (zfcp_qdio_open(adapter->qdio)) {
775 		atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
776 				  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
777 				  &adapter->status);
778 		return ZFCP_ERP_FAILED;
779 	}
780 
781 	if (zfcp_erp_adapter_strategy_open_fsf(act)) {
782 		zfcp_erp_adapter_strategy_close(act);
783 		return ZFCP_ERP_FAILED;
784 	}
785 
786 	atomic_or(ZFCP_STATUS_COMMON_OPEN, &adapter->status);
787 
788 	return ZFCP_ERP_SUCCEEDED;
789 }
790 
791 static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *act)
792 {
793 	struct zfcp_adapter *adapter = act->adapter;
794 
795 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_OPEN) {
796 		zfcp_erp_adapter_strategy_close(act);
797 		if (act->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
798 			return ZFCP_ERP_EXIT;
799 	}
800 
801 	if (zfcp_erp_adapter_strategy_open(act)) {
802 		ssleep(8);
803 		return ZFCP_ERP_FAILED;
804 	}
805 
806 	return ZFCP_ERP_SUCCEEDED;
807 }
808 
809 static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
810 {
811 	int retval;
812 
813 	retval = zfcp_fsf_close_physical_port(act);
814 	if (retval == -ENOMEM)
815 		return ZFCP_ERP_NOMEM;
816 	act->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
817 	if (retval)
818 		return ZFCP_ERP_FAILED;
819 
820 	return ZFCP_ERP_CONTINUES;
821 }
822 
823 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
824 {
825 	struct zfcp_port *port = erp_action->port;
826 	int status = atomic_read(&port->status);
827 
828 	switch (erp_action->step) {
829 	case ZFCP_ERP_STEP_UNINITIALIZED:
830 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
831 		    (status & ZFCP_STATUS_COMMON_OPEN))
832 			return zfcp_erp_port_forced_strategy_close(erp_action);
833 		else
834 			return ZFCP_ERP_FAILED;
835 
836 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
837 		if (!(status & ZFCP_STATUS_PORT_PHYS_OPEN))
838 			return ZFCP_ERP_SUCCEEDED;
839 	}
840 	return ZFCP_ERP_FAILED;
841 }
842 
843 static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
844 {
845 	int retval;
846 
847 	retval = zfcp_fsf_close_port(erp_action);
848 	if (retval == -ENOMEM)
849 		return ZFCP_ERP_NOMEM;
850 	erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
851 	if (retval)
852 		return ZFCP_ERP_FAILED;
853 	return ZFCP_ERP_CONTINUES;
854 }
855 
856 static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
857 {
858 	int retval;
859 
860 	retval = zfcp_fsf_open_port(erp_action);
861 	if (retval == -ENOMEM)
862 		return ZFCP_ERP_NOMEM;
863 	erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
864 	if (retval)
865 		return ZFCP_ERP_FAILED;
866 	return ZFCP_ERP_CONTINUES;
867 }
868 
869 static int zfcp_erp_open_ptp_port(struct zfcp_erp_action *act)
870 {
871 	struct zfcp_adapter *adapter = act->adapter;
872 	struct zfcp_port *port = act->port;
873 
874 	if (port->wwpn != adapter->peer_wwpn) {
875 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
876 		return ZFCP_ERP_FAILED;
877 	}
878 	port->d_id = adapter->peer_d_id;
879 	return zfcp_erp_port_strategy_open_port(act);
880 }
881 
882 static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *act)
883 {
884 	struct zfcp_adapter *adapter = act->adapter;
885 	struct zfcp_port *port = act->port;
886 	int p_status = atomic_read(&port->status);
887 
888 	switch (act->step) {
889 	case ZFCP_ERP_STEP_UNINITIALIZED:
890 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
891 	case ZFCP_ERP_STEP_PORT_CLOSING:
892 		if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
893 			return zfcp_erp_open_ptp_port(act);
894 		if (!port->d_id) {
895 			zfcp_fc_trigger_did_lookup(port);
896 			return ZFCP_ERP_EXIT;
897 		}
898 		return zfcp_erp_port_strategy_open_port(act);
899 
900 	case ZFCP_ERP_STEP_PORT_OPENING:
901 		/* D_ID might have changed during open */
902 		if (p_status & ZFCP_STATUS_COMMON_OPEN) {
903 			if (!port->d_id) {
904 				zfcp_fc_trigger_did_lookup(port);
905 				return ZFCP_ERP_EXIT;
906 			}
907 			return ZFCP_ERP_SUCCEEDED;
908 		}
909 		if (port->d_id && !(p_status & ZFCP_STATUS_COMMON_NOESC)) {
910 			port->d_id = 0;
911 			return ZFCP_ERP_FAILED;
912 		}
913 		/* fall through otherwise */
914 	}
915 	return ZFCP_ERP_FAILED;
916 }
917 
918 static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
919 {
920 	struct zfcp_port *port = erp_action->port;
921 	int p_status = atomic_read(&port->status);
922 
923 	if ((p_status & ZFCP_STATUS_COMMON_NOESC) &&
924 	    !(p_status & ZFCP_STATUS_COMMON_OPEN))
925 		goto close_init_done;
926 
927 	switch (erp_action->step) {
928 	case ZFCP_ERP_STEP_UNINITIALIZED:
929 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
930 			return zfcp_erp_port_strategy_close(erp_action);
931 		break;
932 
933 	case ZFCP_ERP_STEP_PORT_CLOSING:
934 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
935 			return ZFCP_ERP_FAILED;
936 		break;
937 	}
938 
939 close_init_done:
940 	if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
941 		return ZFCP_ERP_EXIT;
942 
943 	return zfcp_erp_port_strategy_open_common(erp_action);
944 }
945 
946 static void zfcp_erp_lun_strategy_clearstati(struct scsi_device *sdev)
947 {
948 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
949 
950 	atomic_andnot(ZFCP_STATUS_COMMON_ACCESS_DENIED,
951 			  &zfcp_sdev->status);
952 }
953 
954 static int zfcp_erp_lun_strategy_close(struct zfcp_erp_action *erp_action)
955 {
956 	int retval = zfcp_fsf_close_lun(erp_action);
957 	if (retval == -ENOMEM)
958 		return ZFCP_ERP_NOMEM;
959 	erp_action->step = ZFCP_ERP_STEP_LUN_CLOSING;
960 	if (retval)
961 		return ZFCP_ERP_FAILED;
962 	return ZFCP_ERP_CONTINUES;
963 }
964 
965 static int zfcp_erp_lun_strategy_open(struct zfcp_erp_action *erp_action)
966 {
967 	int retval = zfcp_fsf_open_lun(erp_action);
968 	if (retval == -ENOMEM)
969 		return ZFCP_ERP_NOMEM;
970 	erp_action->step = ZFCP_ERP_STEP_LUN_OPENING;
971 	if (retval)
972 		return  ZFCP_ERP_FAILED;
973 	return ZFCP_ERP_CONTINUES;
974 }
975 
976 static int zfcp_erp_lun_strategy(struct zfcp_erp_action *erp_action)
977 {
978 	struct scsi_device *sdev = erp_action->sdev;
979 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
980 
981 	switch (erp_action->step) {
982 	case ZFCP_ERP_STEP_UNINITIALIZED:
983 		zfcp_erp_lun_strategy_clearstati(sdev);
984 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
985 			return zfcp_erp_lun_strategy_close(erp_action);
986 		/* already closed, fall through */
987 	case ZFCP_ERP_STEP_LUN_CLOSING:
988 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
989 			return ZFCP_ERP_FAILED;
990 		if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
991 			return ZFCP_ERP_EXIT;
992 		return zfcp_erp_lun_strategy_open(erp_action);
993 
994 	case ZFCP_ERP_STEP_LUN_OPENING:
995 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
996 			return ZFCP_ERP_SUCCEEDED;
997 	}
998 	return ZFCP_ERP_FAILED;
999 }
1000 
1001 static int zfcp_erp_strategy_check_lun(struct scsi_device *sdev, int result)
1002 {
1003 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1004 
1005 	switch (result) {
1006 	case ZFCP_ERP_SUCCEEDED :
1007 		atomic_set(&zfcp_sdev->erp_counter, 0);
1008 		zfcp_erp_lun_unblock(sdev);
1009 		break;
1010 	case ZFCP_ERP_FAILED :
1011 		atomic_inc(&zfcp_sdev->erp_counter);
1012 		if (atomic_read(&zfcp_sdev->erp_counter) > ZFCP_MAX_ERPS) {
1013 			dev_err(&zfcp_sdev->port->adapter->ccw_device->dev,
1014 				"ERP failed for LUN 0x%016Lx on "
1015 				"port 0x%016Lx\n",
1016 				(unsigned long long)zfcp_scsi_dev_lun(sdev),
1017 				(unsigned long long)zfcp_sdev->port->wwpn);
1018 			zfcp_erp_set_lun_status(sdev,
1019 						ZFCP_STATUS_COMMON_ERP_FAILED);
1020 		}
1021 		break;
1022 	}
1023 
1024 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1025 		zfcp_erp_lun_block(sdev, 0);
1026 		result = ZFCP_ERP_EXIT;
1027 	}
1028 	return result;
1029 }
1030 
1031 static int zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
1032 {
1033 	switch (result) {
1034 	case ZFCP_ERP_SUCCEEDED :
1035 		atomic_set(&port->erp_counter, 0);
1036 		zfcp_erp_port_unblock(port);
1037 		break;
1038 
1039 	case ZFCP_ERP_FAILED :
1040 		if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC) {
1041 			zfcp_erp_port_block(port, 0);
1042 			result = ZFCP_ERP_EXIT;
1043 		}
1044 		atomic_inc(&port->erp_counter);
1045 		if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS) {
1046 			dev_err(&port->adapter->ccw_device->dev,
1047 				"ERP failed for remote port 0x%016Lx\n",
1048 				(unsigned long long)port->wwpn);
1049 			zfcp_erp_set_port_status(port,
1050 					 ZFCP_STATUS_COMMON_ERP_FAILED);
1051 		}
1052 		break;
1053 	}
1054 
1055 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1056 		zfcp_erp_port_block(port, 0);
1057 		result = ZFCP_ERP_EXIT;
1058 	}
1059 	return result;
1060 }
1061 
1062 static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter,
1063 					   int result)
1064 {
1065 	switch (result) {
1066 	case ZFCP_ERP_SUCCEEDED :
1067 		atomic_set(&adapter->erp_counter, 0);
1068 		zfcp_erp_adapter_unblock(adapter);
1069 		break;
1070 
1071 	case ZFCP_ERP_FAILED :
1072 		atomic_inc(&adapter->erp_counter);
1073 		if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS) {
1074 			dev_err(&adapter->ccw_device->dev,
1075 				"ERP cannot recover an error "
1076 				"on the FCP device\n");
1077 			zfcp_erp_set_adapter_status(adapter,
1078 					    ZFCP_STATUS_COMMON_ERP_FAILED);
1079 		}
1080 		break;
1081 	}
1082 
1083 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1084 		zfcp_erp_adapter_block(adapter, 0);
1085 		result = ZFCP_ERP_EXIT;
1086 	}
1087 	return result;
1088 }
1089 
1090 static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action,
1091 					  int result)
1092 {
1093 	struct zfcp_adapter *adapter = erp_action->adapter;
1094 	struct zfcp_port *port = erp_action->port;
1095 	struct scsi_device *sdev = erp_action->sdev;
1096 
1097 	switch (erp_action->action) {
1098 
1099 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1100 		result = zfcp_erp_strategy_check_lun(sdev, result);
1101 		break;
1102 
1103 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1104 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1105 		result = zfcp_erp_strategy_check_port(port, result);
1106 		break;
1107 
1108 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1109 		result = zfcp_erp_strategy_check_adapter(adapter, result);
1110 		break;
1111 	}
1112 	return result;
1113 }
1114 
1115 static int zfcp_erp_strat_change_det(atomic_t *target_status, u32 erp_status)
1116 {
1117 	int status = atomic_read(target_status);
1118 
1119 	if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
1120 	    (erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1121 		return 1; /* take it online */
1122 
1123 	if (!(status & ZFCP_STATUS_COMMON_RUNNING) &&
1124 	    !(erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1125 		return 1; /* take it offline */
1126 
1127 	return 0;
1128 }
1129 
1130 static int zfcp_erp_strategy_statechange(struct zfcp_erp_action *act, int ret)
1131 {
1132 	int action = act->action;
1133 	struct zfcp_adapter *adapter = act->adapter;
1134 	struct zfcp_port *port = act->port;
1135 	struct scsi_device *sdev = act->sdev;
1136 	struct zfcp_scsi_dev *zfcp_sdev;
1137 	u32 erp_status = act->status;
1138 
1139 	switch (action) {
1140 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1141 		if (zfcp_erp_strat_change_det(&adapter->status, erp_status)) {
1142 			_zfcp_erp_adapter_reopen(adapter,
1143 						 ZFCP_STATUS_COMMON_ERP_FAILED,
1144 						 "ersscg1");
1145 			return ZFCP_ERP_EXIT;
1146 		}
1147 		break;
1148 
1149 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1150 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1151 		if (zfcp_erp_strat_change_det(&port->status, erp_status)) {
1152 			_zfcp_erp_port_reopen(port,
1153 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1154 					      "ersscg2");
1155 			return ZFCP_ERP_EXIT;
1156 		}
1157 		break;
1158 
1159 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1160 		zfcp_sdev = sdev_to_zfcp(sdev);
1161 		if (zfcp_erp_strat_change_det(&zfcp_sdev->status, erp_status)) {
1162 			_zfcp_erp_lun_reopen(sdev,
1163 					     ZFCP_STATUS_COMMON_ERP_FAILED,
1164 					     "ersscg3", 0);
1165 			return ZFCP_ERP_EXIT;
1166 		}
1167 		break;
1168 	}
1169 	return ret;
1170 }
1171 
1172 static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
1173 {
1174 	struct zfcp_adapter *adapter = erp_action->adapter;
1175 	struct zfcp_scsi_dev *zfcp_sdev;
1176 
1177 	adapter->erp_total_count--;
1178 	if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1179 		adapter->erp_low_mem_count--;
1180 		erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1181 	}
1182 
1183 	list_del(&erp_action->list);
1184 	zfcp_dbf_rec_run("eractd1", erp_action);
1185 
1186 	switch (erp_action->action) {
1187 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1188 		zfcp_sdev = sdev_to_zfcp(erp_action->sdev);
1189 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1190 				  &zfcp_sdev->status);
1191 		break;
1192 
1193 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1194 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1195 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1196 				  &erp_action->port->status);
1197 		break;
1198 
1199 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1200 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1201 				  &erp_action->adapter->status);
1202 		break;
1203 	}
1204 }
1205 
1206 /**
1207  * zfcp_erp_try_rport_unblock - unblock rport if no more/new recovery
1208  * @port: zfcp_port whose fc_rport we should try to unblock
1209  */
1210 static void zfcp_erp_try_rport_unblock(struct zfcp_port *port)
1211 {
1212 	unsigned long flags;
1213 	struct zfcp_adapter *adapter = port->adapter;
1214 	int port_status;
1215 	struct Scsi_Host *shost = adapter->scsi_host;
1216 	struct scsi_device *sdev;
1217 
1218 	write_lock_irqsave(&adapter->erp_lock, flags);
1219 	port_status = atomic_read(&port->status);
1220 	if ((port_status & ZFCP_STATUS_COMMON_UNBLOCKED)    == 0 ||
1221 	    (port_status & (ZFCP_STATUS_COMMON_ERP_INUSE |
1222 			    ZFCP_STATUS_COMMON_ERP_FAILED)) != 0) {
1223 		/* new ERP of severity >= port triggered elsewhere meanwhile or
1224 		 * local link down (adapter erp_failed but not clear unblock)
1225 		 */
1226 		zfcp_dbf_rec_run_lvl(4, "ertru_p", &port->erp_action);
1227 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1228 		return;
1229 	}
1230 	spin_lock(shost->host_lock);
1231 	__shost_for_each_device(sdev, shost) {
1232 		struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
1233 		int lun_status;
1234 
1235 		if (zsdev->port != port)
1236 			continue;
1237 		/* LUN under port of interest */
1238 		lun_status = atomic_read(&zsdev->status);
1239 		if ((lun_status & ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
1240 			continue; /* unblock rport despite failed LUNs */
1241 		/* LUN recovery not given up yet [maybe follow-up pending] */
1242 		if ((lun_status & ZFCP_STATUS_COMMON_UNBLOCKED) == 0 ||
1243 		    (lun_status & ZFCP_STATUS_COMMON_ERP_INUSE) != 0) {
1244 			/* LUN blocked:
1245 			 * not yet unblocked [LUN recovery pending]
1246 			 * or meanwhile blocked [new LUN recovery triggered]
1247 			 */
1248 			zfcp_dbf_rec_run_lvl(4, "ertru_l", &zsdev->erp_action);
1249 			spin_unlock(shost->host_lock);
1250 			write_unlock_irqrestore(&adapter->erp_lock, flags);
1251 			return;
1252 		}
1253 	}
1254 	/* now port has no child or all children have completed recovery,
1255 	 * and no ERP of severity >= port was meanwhile triggered elsewhere
1256 	 */
1257 	zfcp_scsi_schedule_rport_register(port);
1258 	spin_unlock(shost->host_lock);
1259 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1260 }
1261 
1262 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
1263 {
1264 	struct zfcp_adapter *adapter = act->adapter;
1265 	struct zfcp_port *port = act->port;
1266 	struct scsi_device *sdev = act->sdev;
1267 
1268 	switch (act->action) {
1269 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1270 		if (!(act->status & ZFCP_STATUS_ERP_NO_REF))
1271 			scsi_device_put(sdev);
1272 		zfcp_erp_try_rport_unblock(port);
1273 		break;
1274 
1275 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1276 		/* This switch case might also happen after a forced reopen
1277 		 * was successfully done and thus overwritten with a new
1278 		 * non-forced reopen at `ersfs_2'. In this case, we must not
1279 		 * do the clean-up of the non-forced version.
1280 		 */
1281 		if (act->step != ZFCP_ERP_STEP_UNINITIALIZED)
1282 			if (result == ZFCP_ERP_SUCCEEDED)
1283 				zfcp_erp_try_rport_unblock(port);
1284 		/* fall through */
1285 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1286 		put_device(&port->dev);
1287 		break;
1288 
1289 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1290 		if (result == ZFCP_ERP_SUCCEEDED) {
1291 			register_service_level(&adapter->service_level);
1292 			zfcp_fc_conditional_port_scan(adapter);
1293 			queue_work(adapter->work_queue, &adapter->ns_up_work);
1294 		} else
1295 			unregister_service_level(&adapter->service_level);
1296 
1297 		kref_put(&adapter->ref, zfcp_adapter_release);
1298 		break;
1299 	}
1300 }
1301 
1302 static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
1303 {
1304 	switch (erp_action->action) {
1305 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1306 		return zfcp_erp_adapter_strategy(erp_action);
1307 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1308 		return zfcp_erp_port_forced_strategy(erp_action);
1309 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1310 		return zfcp_erp_port_strategy(erp_action);
1311 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1312 		return zfcp_erp_lun_strategy(erp_action);
1313 	}
1314 	return ZFCP_ERP_FAILED;
1315 }
1316 
1317 static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
1318 {
1319 	int retval;
1320 	unsigned long flags;
1321 	struct zfcp_adapter *adapter = erp_action->adapter;
1322 
1323 	kref_get(&adapter->ref);
1324 
1325 	write_lock_irqsave(&adapter->erp_lock, flags);
1326 	zfcp_erp_strategy_check_fsfreq(erp_action);
1327 
1328 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
1329 		zfcp_erp_action_dequeue(erp_action);
1330 		retval = ZFCP_ERP_DISMISSED;
1331 		goto unlock;
1332 	}
1333 
1334 	if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
1335 		retval = ZFCP_ERP_FAILED;
1336 		goto check_target;
1337 	}
1338 
1339 	zfcp_erp_action_to_running(erp_action);
1340 
1341 	/* no lock to allow for blocking operations */
1342 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1343 	retval = zfcp_erp_strategy_do_action(erp_action);
1344 	write_lock_irqsave(&adapter->erp_lock, flags);
1345 
1346 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
1347 		retval = ZFCP_ERP_CONTINUES;
1348 
1349 	switch (retval) {
1350 	case ZFCP_ERP_NOMEM:
1351 		if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
1352 			++adapter->erp_low_mem_count;
1353 			erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
1354 		}
1355 		if (adapter->erp_total_count == adapter->erp_low_mem_count)
1356 			_zfcp_erp_adapter_reopen(adapter, 0, "erstgy1");
1357 		else {
1358 			zfcp_erp_strategy_memwait(erp_action);
1359 			retval = ZFCP_ERP_CONTINUES;
1360 		}
1361 		goto unlock;
1362 
1363 	case ZFCP_ERP_CONTINUES:
1364 		if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1365 			--adapter->erp_low_mem_count;
1366 			erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1367 		}
1368 		goto unlock;
1369 	}
1370 
1371 check_target:
1372 	retval = zfcp_erp_strategy_check_target(erp_action, retval);
1373 	zfcp_erp_action_dequeue(erp_action);
1374 	retval = zfcp_erp_strategy_statechange(erp_action, retval);
1375 	if (retval == ZFCP_ERP_EXIT)
1376 		goto unlock;
1377 	if (retval == ZFCP_ERP_SUCCEEDED)
1378 		zfcp_erp_strategy_followup_success(erp_action);
1379 	if (retval == ZFCP_ERP_FAILED)
1380 		zfcp_erp_strategy_followup_failed(erp_action);
1381 
1382  unlock:
1383 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1384 
1385 	if (retval != ZFCP_ERP_CONTINUES)
1386 		zfcp_erp_action_cleanup(erp_action, retval);
1387 
1388 	kref_put(&adapter->ref, zfcp_adapter_release);
1389 	return retval;
1390 }
1391 
1392 static int zfcp_erp_thread(void *data)
1393 {
1394 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
1395 	struct list_head *next;
1396 	struct zfcp_erp_action *act;
1397 	unsigned long flags;
1398 
1399 	for (;;) {
1400 		wait_event_interruptible(adapter->erp_ready_wq,
1401 			   !list_empty(&adapter->erp_ready_head) ||
1402 			   kthread_should_stop());
1403 
1404 		if (kthread_should_stop())
1405 			break;
1406 
1407 		write_lock_irqsave(&adapter->erp_lock, flags);
1408 		next = adapter->erp_ready_head.next;
1409 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1410 
1411 		if (next != &adapter->erp_ready_head) {
1412 			act = list_entry(next, struct zfcp_erp_action, list);
1413 
1414 			/* there is more to come after dismission, no notify */
1415 			if (zfcp_erp_strategy(act) != ZFCP_ERP_DISMISSED)
1416 				zfcp_erp_wakeup(adapter);
1417 		}
1418 	}
1419 
1420 	return 0;
1421 }
1422 
1423 /**
1424  * zfcp_erp_thread_setup - Start ERP thread for adapter
1425  * @adapter: Adapter to start the ERP thread for
1426  *
1427  * Returns 0 on success or error code from kernel_thread()
1428  */
1429 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
1430 {
1431 	struct task_struct *thread;
1432 
1433 	thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
1434 			     dev_name(&adapter->ccw_device->dev));
1435 	if (IS_ERR(thread)) {
1436 		dev_err(&adapter->ccw_device->dev,
1437 			"Creating an ERP thread for the FCP device failed.\n");
1438 		return PTR_ERR(thread);
1439 	}
1440 
1441 	adapter->erp_thread = thread;
1442 	return 0;
1443 }
1444 
1445 /**
1446  * zfcp_erp_thread_kill - Stop ERP thread.
1447  * @adapter: Adapter where the ERP thread should be stopped.
1448  *
1449  * The caller of this routine ensures that the specified adapter has
1450  * been shut down and that this operation has been completed. Thus,
1451  * there are no pending erp_actions which would need to be handled
1452  * here.
1453  */
1454 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
1455 {
1456 	kthread_stop(adapter->erp_thread);
1457 	adapter->erp_thread = NULL;
1458 	WARN_ON(!list_empty(&adapter->erp_ready_head));
1459 	WARN_ON(!list_empty(&adapter->erp_running_head));
1460 }
1461 
1462 /**
1463  * zfcp_erp_wait - wait for completion of error recovery on an adapter
1464  * @adapter: adapter for which to wait for completion of its error recovery
1465  */
1466 void zfcp_erp_wait(struct zfcp_adapter *adapter)
1467 {
1468 	wait_event(adapter->erp_done_wqh,
1469 		   !(atomic_read(&adapter->status) &
1470 			ZFCP_STATUS_ADAPTER_ERP_PENDING));
1471 }
1472 
1473 /**
1474  * zfcp_erp_set_adapter_status - set adapter status bits
1475  * @adapter: adapter to change the status
1476  * @mask: status bits to change
1477  *
1478  * Changes in common status bits are propagated to attached ports and LUNs.
1479  */
1480 void zfcp_erp_set_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1481 {
1482 	struct zfcp_port *port;
1483 	struct scsi_device *sdev;
1484 	unsigned long flags;
1485 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1486 
1487 	atomic_or(mask, &adapter->status);
1488 
1489 	if (!common_mask)
1490 		return;
1491 
1492 	read_lock_irqsave(&adapter->port_list_lock, flags);
1493 	list_for_each_entry(port, &adapter->port_list, list)
1494 		atomic_or(common_mask, &port->status);
1495 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1496 
1497 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1498 	__shost_for_each_device(sdev, adapter->scsi_host)
1499 		atomic_or(common_mask, &sdev_to_zfcp(sdev)->status);
1500 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1501 }
1502 
1503 /**
1504  * zfcp_erp_clear_adapter_status - clear adapter status bits
1505  * @adapter: adapter to change the status
1506  * @mask: status bits to change
1507  *
1508  * Changes in common status bits are propagated to attached ports and LUNs.
1509  */
1510 void zfcp_erp_clear_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1511 {
1512 	struct zfcp_port *port;
1513 	struct scsi_device *sdev;
1514 	unsigned long flags;
1515 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1516 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1517 
1518 	atomic_andnot(mask, &adapter->status);
1519 
1520 	if (!common_mask)
1521 		return;
1522 
1523 	if (clear_counter)
1524 		atomic_set(&adapter->erp_counter, 0);
1525 
1526 	read_lock_irqsave(&adapter->port_list_lock, flags);
1527 	list_for_each_entry(port, &adapter->port_list, list) {
1528 		atomic_andnot(common_mask, &port->status);
1529 		if (clear_counter)
1530 			atomic_set(&port->erp_counter, 0);
1531 	}
1532 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1533 
1534 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1535 	__shost_for_each_device(sdev, adapter->scsi_host) {
1536 		atomic_andnot(common_mask, &sdev_to_zfcp(sdev)->status);
1537 		if (clear_counter)
1538 			atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1539 	}
1540 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1541 }
1542 
1543 /**
1544  * zfcp_erp_set_port_status - set port status bits
1545  * @port: port to change the status
1546  * @mask: status bits to change
1547  *
1548  * Changes in common status bits are propagated to attached LUNs.
1549  */
1550 void zfcp_erp_set_port_status(struct zfcp_port *port, u32 mask)
1551 {
1552 	struct scsi_device *sdev;
1553 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1554 	unsigned long flags;
1555 
1556 	atomic_or(mask, &port->status);
1557 
1558 	if (!common_mask)
1559 		return;
1560 
1561 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1562 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1563 		if (sdev_to_zfcp(sdev)->port == port)
1564 			atomic_or(common_mask,
1565 					&sdev_to_zfcp(sdev)->status);
1566 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1567 }
1568 
1569 /**
1570  * zfcp_erp_clear_port_status - clear port status bits
1571  * @port: adapter to change the status
1572  * @mask: status bits to change
1573  *
1574  * Changes in common status bits are propagated to attached LUNs.
1575  */
1576 void zfcp_erp_clear_port_status(struct zfcp_port *port, u32 mask)
1577 {
1578 	struct scsi_device *sdev;
1579 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1580 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1581 	unsigned long flags;
1582 
1583 	atomic_andnot(mask, &port->status);
1584 
1585 	if (!common_mask)
1586 		return;
1587 
1588 	if (clear_counter)
1589 		atomic_set(&port->erp_counter, 0);
1590 
1591 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1592 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1593 		if (sdev_to_zfcp(sdev)->port == port) {
1594 			atomic_andnot(common_mask,
1595 					  &sdev_to_zfcp(sdev)->status);
1596 			if (clear_counter)
1597 				atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1598 		}
1599 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1600 }
1601 
1602 /**
1603  * zfcp_erp_set_lun_status - set lun status bits
1604  * @sdev: SCSI device / lun to set the status bits
1605  * @mask: status bits to change
1606  */
1607 void zfcp_erp_set_lun_status(struct scsi_device *sdev, u32 mask)
1608 {
1609 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1610 
1611 	atomic_or(mask, &zfcp_sdev->status);
1612 }
1613 
1614 /**
1615  * zfcp_erp_clear_lun_status - clear lun status bits
1616  * @sdev: SCSi device / lun to clear the status bits
1617  * @mask: status bits to change
1618  */
1619 void zfcp_erp_clear_lun_status(struct scsi_device *sdev, u32 mask)
1620 {
1621 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1622 
1623 	atomic_andnot(mask, &zfcp_sdev->status);
1624 
1625 	if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1626 		atomic_set(&zfcp_sdev->erp_counter, 0);
1627 }
1628 
1629