xref: /openbmc/linux/drivers/s390/scsi/zfcp_erp.c (revision 7dd65feb)
1 /*
2  * zfcp device driver
3  *
4  * Error Recovery Procedures (ERP).
5  *
6  * Copyright IBM Corporation 2002, 2009
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 
15 #define ZFCP_MAX_ERPS                   3
16 
17 enum zfcp_erp_act_flags {
18 	ZFCP_STATUS_ERP_TIMEDOUT	= 0x10000000,
19 	ZFCP_STATUS_ERP_CLOSE_ONLY	= 0x01000000,
20 	ZFCP_STATUS_ERP_DISMISSING	= 0x00100000,
21 	ZFCP_STATUS_ERP_DISMISSED	= 0x00200000,
22 	ZFCP_STATUS_ERP_LOWMEM		= 0x00400000,
23 };
24 
25 enum zfcp_erp_steps {
26 	ZFCP_ERP_STEP_UNINITIALIZED	= 0x0000,
27 	ZFCP_ERP_STEP_FSF_XCONFIG	= 0x0001,
28 	ZFCP_ERP_STEP_PHYS_PORT_CLOSING	= 0x0010,
29 	ZFCP_ERP_STEP_PORT_CLOSING	= 0x0100,
30 	ZFCP_ERP_STEP_PORT_OPENING	= 0x0800,
31 	ZFCP_ERP_STEP_UNIT_CLOSING	= 0x1000,
32 	ZFCP_ERP_STEP_UNIT_OPENING	= 0x2000,
33 };
34 
35 enum zfcp_erp_act_type {
36 	ZFCP_ERP_ACTION_REOPEN_UNIT        = 1,
37 	ZFCP_ERP_ACTION_REOPEN_PORT	   = 2,
38 	ZFCP_ERP_ACTION_REOPEN_PORT_FORCED = 3,
39 	ZFCP_ERP_ACTION_REOPEN_ADAPTER     = 4,
40 };
41 
42 enum zfcp_erp_act_state {
43 	ZFCP_ERP_ACTION_RUNNING = 1,
44 	ZFCP_ERP_ACTION_READY   = 2,
45 };
46 
47 enum zfcp_erp_act_result {
48 	ZFCP_ERP_SUCCEEDED = 0,
49 	ZFCP_ERP_FAILED    = 1,
50 	ZFCP_ERP_CONTINUES = 2,
51 	ZFCP_ERP_EXIT      = 3,
52 	ZFCP_ERP_DISMISSED = 4,
53 	ZFCP_ERP_NOMEM     = 5,
54 };
55 
56 static void zfcp_erp_adapter_block(struct zfcp_adapter *adapter, int mask)
57 {
58 	zfcp_erp_modify_adapter_status(adapter, "erablk1", NULL,
59 				       ZFCP_STATUS_COMMON_UNBLOCKED | mask,
60 				       ZFCP_CLEAR);
61 }
62 
63 static int zfcp_erp_action_exists(struct zfcp_erp_action *act)
64 {
65 	struct zfcp_erp_action *curr_act;
66 
67 	list_for_each_entry(curr_act, &act->adapter->erp_running_head, list)
68 		if (act == curr_act)
69 			return ZFCP_ERP_ACTION_RUNNING;
70 	return 0;
71 }
72 
73 static void zfcp_erp_action_ready(struct zfcp_erp_action *act)
74 {
75 	struct zfcp_adapter *adapter = act->adapter;
76 
77 	list_move(&act->list, &act->adapter->erp_ready_head);
78 	zfcp_dbf_rec_action("erardy1", act);
79 	wake_up(&adapter->erp_ready_wq);
80 	zfcp_dbf_rec_thread("erardy2", adapter->dbf);
81 }
82 
83 static void zfcp_erp_action_dismiss(struct zfcp_erp_action *act)
84 {
85 	act->status |= ZFCP_STATUS_ERP_DISMISSED;
86 	if (zfcp_erp_action_exists(act) == ZFCP_ERP_ACTION_RUNNING)
87 		zfcp_erp_action_ready(act);
88 }
89 
90 static void zfcp_erp_action_dismiss_unit(struct zfcp_unit *unit)
91 {
92 	if (atomic_read(&unit->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
93 		zfcp_erp_action_dismiss(&unit->erp_action);
94 }
95 
96 static void zfcp_erp_action_dismiss_port(struct zfcp_port *port)
97 {
98 	struct zfcp_unit *unit;
99 
100 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
101 		zfcp_erp_action_dismiss(&port->erp_action);
102 	else {
103 		read_lock(&port->unit_list_lock);
104 		list_for_each_entry(unit, &port->unit_list, list)
105 			zfcp_erp_action_dismiss_unit(unit);
106 		read_unlock(&port->unit_list_lock);
107 	}
108 }
109 
110 static void zfcp_erp_action_dismiss_adapter(struct zfcp_adapter *adapter)
111 {
112 	struct zfcp_port *port;
113 
114 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
115 		zfcp_erp_action_dismiss(&adapter->erp_action);
116 	else {
117 		read_lock(&adapter->port_list_lock);
118 		list_for_each_entry(port, &adapter->port_list, list)
119 		    zfcp_erp_action_dismiss_port(port);
120 		read_unlock(&adapter->port_list_lock);
121 	}
122 }
123 
124 static int zfcp_erp_required_act(int want, struct zfcp_adapter *adapter,
125 				 struct zfcp_port *port,
126 				 struct zfcp_unit *unit)
127 {
128 	int need = want;
129 	int u_status, p_status, a_status;
130 
131 	switch (want) {
132 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
133 		u_status = atomic_read(&unit->status);
134 		if (u_status & ZFCP_STATUS_COMMON_ERP_INUSE)
135 			return 0;
136 		p_status = atomic_read(&port->status);
137 		if (!(p_status & ZFCP_STATUS_COMMON_RUNNING) ||
138 		      p_status & ZFCP_STATUS_COMMON_ERP_FAILED)
139 			return 0;
140 		if (!(p_status & ZFCP_STATUS_COMMON_UNBLOCKED))
141 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
142 		/* fall through */
143 	case ZFCP_ERP_ACTION_REOPEN_PORT:
144 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
145 		p_status = atomic_read(&port->status);
146 		if (p_status & ZFCP_STATUS_COMMON_ERP_INUSE)
147 			return 0;
148 		a_status = atomic_read(&adapter->status);
149 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) ||
150 		      a_status & ZFCP_STATUS_COMMON_ERP_FAILED)
151 			return 0;
152 		if (!(a_status & ZFCP_STATUS_COMMON_UNBLOCKED))
153 			need = ZFCP_ERP_ACTION_REOPEN_ADAPTER;
154 		/* fall through */
155 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
156 		a_status = atomic_read(&adapter->status);
157 		if (a_status & ZFCP_STATUS_COMMON_ERP_INUSE)
158 			return 0;
159 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) &&
160 		    !(a_status & ZFCP_STATUS_COMMON_OPEN))
161 			return 0; /* shutdown requested for closed adapter */
162 	}
163 
164 	return need;
165 }
166 
167 static struct zfcp_erp_action *zfcp_erp_setup_act(int need,
168 						  struct zfcp_adapter *adapter,
169 						  struct zfcp_port *port,
170 						  struct zfcp_unit *unit)
171 {
172 	struct zfcp_erp_action *erp_action;
173 	u32 status = 0;
174 
175 	switch (need) {
176 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
177 		if (!get_device(&unit->sysfs_device))
178 			return NULL;
179 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &unit->status);
180 		erp_action = &unit->erp_action;
181 		if (!(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_RUNNING))
182 			status = ZFCP_STATUS_ERP_CLOSE_ONLY;
183 		break;
184 
185 	case ZFCP_ERP_ACTION_REOPEN_PORT:
186 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
187 		if (!get_device(&port->sysfs_device))
188 			return NULL;
189 		zfcp_erp_action_dismiss_port(port);
190 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status);
191 		erp_action = &port->erp_action;
192 		if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_RUNNING))
193 			status = ZFCP_STATUS_ERP_CLOSE_ONLY;
194 		break;
195 
196 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
197 		kref_get(&adapter->ref);
198 		zfcp_erp_action_dismiss_adapter(adapter);
199 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status);
200 		erp_action = &adapter->erp_action;
201 		if (!(atomic_read(&adapter->status) &
202 		      ZFCP_STATUS_COMMON_RUNNING))
203 			status = ZFCP_STATUS_ERP_CLOSE_ONLY;
204 		break;
205 
206 	default:
207 		return NULL;
208 	}
209 
210 	memset(erp_action, 0, sizeof(struct zfcp_erp_action));
211 	erp_action->adapter = adapter;
212 	erp_action->port = port;
213 	erp_action->unit = unit;
214 	erp_action->action = need;
215 	erp_action->status = status;
216 
217 	return erp_action;
218 }
219 
220 static int zfcp_erp_action_enqueue(int want, struct zfcp_adapter *adapter,
221 				   struct zfcp_port *port,
222 				   struct zfcp_unit *unit, char *id, void *ref)
223 {
224 	int retval = 1, need;
225 	struct zfcp_erp_action *act = NULL;
226 
227 	if (!adapter->erp_thread)
228 		return -EIO;
229 
230 	need = zfcp_erp_required_act(want, adapter, port, unit);
231 	if (!need)
232 		goto out;
233 
234 	atomic_set_mask(ZFCP_STATUS_ADAPTER_ERP_PENDING, &adapter->status);
235 	act = zfcp_erp_setup_act(need, adapter, port, unit);
236 	if (!act)
237 		goto out;
238 	++adapter->erp_total_count;
239 	list_add_tail(&act->list, &adapter->erp_ready_head);
240 	wake_up(&adapter->erp_ready_wq);
241 	zfcp_dbf_rec_thread("eracte1", adapter->dbf);
242 	retval = 0;
243  out:
244 	zfcp_dbf_rec_trigger(id, ref, want, need, act, adapter, port, unit);
245 	return retval;
246 }
247 
248 static int _zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter,
249 				    int clear_mask, char *id, void *ref)
250 {
251 	zfcp_erp_adapter_block(adapter, clear_mask);
252 	zfcp_scsi_schedule_rports_block(adapter);
253 
254 	/* ensure propagation of failed status to new devices */
255 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
256 		zfcp_erp_adapter_failed(adapter, "erareo1", NULL);
257 		return -EIO;
258 	}
259 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER,
260 				       adapter, NULL, NULL, id, ref);
261 }
262 
263 /**
264  * zfcp_erp_adapter_reopen - Reopen adapter.
265  * @adapter: Adapter to reopen.
266  * @clear: Status flags to clear.
267  * @id: Id for debug trace event.
268  * @ref: Reference for debug trace event.
269  */
270 void zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter, int clear,
271 			     char *id, void *ref)
272 {
273 	unsigned long flags;
274 
275 	zfcp_erp_adapter_block(adapter, clear);
276 	zfcp_scsi_schedule_rports_block(adapter);
277 
278 	write_lock_irqsave(&adapter->erp_lock, flags);
279 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
280 		zfcp_erp_adapter_failed(adapter, "erareo1", NULL);
281 	else
282 		zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER, adapter,
283 					NULL, NULL, id, ref);
284 	write_unlock_irqrestore(&adapter->erp_lock, flags);
285 }
286 
287 /**
288  * zfcp_erp_adapter_shutdown - Shutdown adapter.
289  * @adapter: Adapter to shut down.
290  * @clear: Status flags to clear.
291  * @id: Id for debug trace event.
292  * @ref: Reference for debug trace event.
293  */
294 void zfcp_erp_adapter_shutdown(struct zfcp_adapter *adapter, int clear,
295 			       char *id, void *ref)
296 {
297 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
298 	zfcp_erp_adapter_reopen(adapter, clear | flags, id, ref);
299 }
300 
301 /**
302  * zfcp_erp_port_shutdown - Shutdown port
303  * @port: Port to shut down.
304  * @clear: Status flags to clear.
305  * @id: Id for debug trace event.
306  * @ref: Reference for debug trace event.
307  */
308 void zfcp_erp_port_shutdown(struct zfcp_port *port, int clear, char *id,
309 			    void *ref)
310 {
311 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
312 	zfcp_erp_port_reopen(port, clear | flags, id, ref);
313 }
314 
315 /**
316  * zfcp_erp_unit_shutdown - Shutdown unit
317  * @unit: Unit to shut down.
318  * @clear: Status flags to clear.
319  * @id: Id for debug trace event.
320  * @ref: Reference for debug trace event.
321  */
322 void zfcp_erp_unit_shutdown(struct zfcp_unit *unit, int clear, char *id,
323 			    void *ref)
324 {
325 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
326 	zfcp_erp_unit_reopen(unit, clear | flags, id, ref);
327 }
328 
329 static void zfcp_erp_port_block(struct zfcp_port *port, int clear)
330 {
331 	zfcp_erp_modify_port_status(port, "erpblk1", NULL,
332 				    ZFCP_STATUS_COMMON_UNBLOCKED | clear,
333 				    ZFCP_CLEAR);
334 }
335 
336 static void _zfcp_erp_port_forced_reopen(struct zfcp_port *port,
337 					 int clear, char *id, void *ref)
338 {
339 	zfcp_erp_port_block(port, clear);
340 	zfcp_scsi_schedule_rport_block(port);
341 
342 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
343 		return;
344 
345 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
346 				port->adapter, port, NULL, id, ref);
347 }
348 
349 /**
350  * zfcp_erp_port_forced_reopen - Forced close of port and open again
351  * @port: Port to force close and to reopen.
352  * @id: Id for debug trace event.
353  * @ref: Reference for debug trace event.
354  */
355 void zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear, char *id,
356 				 void *ref)
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, ref);
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 				 void *ref)
368 {
369 	zfcp_erp_port_block(port, clear);
370 	zfcp_scsi_schedule_rport_block(port);
371 
372 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
373 		/* ensure propagation of failed status to new devices */
374 		zfcp_erp_port_failed(port, "erpreo1", NULL);
375 		return -EIO;
376 	}
377 
378 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT,
379 				       port->adapter, port, NULL, id, ref);
380 }
381 
382 /**
383  * zfcp_erp_port_reopen - trigger remote port recovery
384  * @port: port to recover
385  * @clear_mask: flags in port status to be cleared
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, void *ref)
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, ref);
397 	write_unlock_irqrestore(&adapter->erp_lock, flags);
398 
399 	return retval;
400 }
401 
402 static void zfcp_erp_unit_block(struct zfcp_unit *unit, int clear_mask)
403 {
404 	zfcp_erp_modify_unit_status(unit, "erublk1", NULL,
405 				    ZFCP_STATUS_COMMON_UNBLOCKED | clear_mask,
406 				    ZFCP_CLEAR);
407 }
408 
409 static void _zfcp_erp_unit_reopen(struct zfcp_unit *unit, int clear, char *id,
410 				  void *ref)
411 {
412 	struct zfcp_adapter *adapter = unit->port->adapter;
413 
414 	zfcp_erp_unit_block(unit, clear);
415 
416 	if (atomic_read(&unit->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
417 		return;
418 
419 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_UNIT,
420 				adapter, unit->port, unit, id, ref);
421 }
422 
423 /**
424  * zfcp_erp_unit_reopen - initiate reopen of a unit
425  * @unit: unit to be reopened
426  * @clear_mask: specifies flags in unit status to be cleared
427  * Return: 0 on success, < 0 on error
428  */
429 void zfcp_erp_unit_reopen(struct zfcp_unit *unit, int clear, char *id,
430 			  void *ref)
431 {
432 	unsigned long flags;
433 	struct zfcp_port *port = unit->port;
434 	struct zfcp_adapter *adapter = port->adapter;
435 
436 	write_lock_irqsave(&adapter->erp_lock, flags);
437 	_zfcp_erp_unit_reopen(unit, clear, id, ref);
438 	write_unlock_irqrestore(&adapter->erp_lock, flags);
439 }
440 
441 static int status_change_set(unsigned long mask, atomic_t *status)
442 {
443 	return (atomic_read(status) ^ mask) & mask;
444 }
445 
446 static int status_change_clear(unsigned long mask, atomic_t *status)
447 {
448 	return atomic_read(status) & mask;
449 }
450 
451 static void zfcp_erp_adapter_unblock(struct zfcp_adapter *adapter)
452 {
453 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status))
454 		zfcp_dbf_rec_adapter("eraubl1", NULL, adapter->dbf);
455 	atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status);
456 }
457 
458 static void zfcp_erp_port_unblock(struct zfcp_port *port)
459 {
460 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status))
461 		zfcp_dbf_rec_port("erpubl1", NULL, port);
462 	atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status);
463 }
464 
465 static void zfcp_erp_unit_unblock(struct zfcp_unit *unit)
466 {
467 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &unit->status))
468 		zfcp_dbf_rec_unit("eruubl1", NULL, unit);
469 	atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &unit->status);
470 }
471 
472 static void zfcp_erp_action_to_running(struct zfcp_erp_action *erp_action)
473 {
474 	list_move(&erp_action->list, &erp_action->adapter->erp_running_head);
475 	zfcp_dbf_rec_action("erator1", erp_action);
476 }
477 
478 static void zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *act)
479 {
480 	struct zfcp_adapter *adapter = act->adapter;
481 
482 	if (!act->fsf_req)
483 		return;
484 
485 	spin_lock(&adapter->req_list_lock);
486 	if (zfcp_reqlist_find_safe(adapter, act->fsf_req) &&
487 	    act->fsf_req->erp_action == act) {
488 		if (act->status & (ZFCP_STATUS_ERP_DISMISSED |
489 				   ZFCP_STATUS_ERP_TIMEDOUT)) {
490 			act->fsf_req->status |= ZFCP_STATUS_FSFREQ_DISMISSED;
491 			zfcp_dbf_rec_action("erscf_1", act);
492 			act->fsf_req->erp_action = NULL;
493 		}
494 		if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
495 			zfcp_dbf_rec_action("erscf_2", act);
496 		if (act->fsf_req->status & ZFCP_STATUS_FSFREQ_DISMISSED)
497 			act->fsf_req = NULL;
498 	} else
499 		act->fsf_req = NULL;
500 	spin_unlock(&adapter->req_list_lock);
501 }
502 
503 /**
504  * zfcp_erp_notify - Trigger ERP action.
505  * @erp_action: ERP action to continue.
506  * @set_mask: ERP action status flags to set.
507  */
508 void zfcp_erp_notify(struct zfcp_erp_action *erp_action, unsigned long set_mask)
509 {
510 	struct zfcp_adapter *adapter = erp_action->adapter;
511 	unsigned long flags;
512 
513 	write_lock_irqsave(&adapter->erp_lock, flags);
514 	if (zfcp_erp_action_exists(erp_action) == ZFCP_ERP_ACTION_RUNNING) {
515 		erp_action->status |= set_mask;
516 		zfcp_erp_action_ready(erp_action);
517 	}
518 	write_unlock_irqrestore(&adapter->erp_lock, flags);
519 }
520 
521 /**
522  * zfcp_erp_timeout_handler - Trigger ERP action from timed out ERP request
523  * @data: ERP action (from timer data)
524  */
525 void zfcp_erp_timeout_handler(unsigned long data)
526 {
527 	struct zfcp_erp_action *act = (struct zfcp_erp_action *) data;
528 	zfcp_erp_notify(act, ZFCP_STATUS_ERP_TIMEDOUT);
529 }
530 
531 static void zfcp_erp_memwait_handler(unsigned long data)
532 {
533 	zfcp_erp_notify((struct zfcp_erp_action *)data, 0);
534 }
535 
536 static void zfcp_erp_strategy_memwait(struct zfcp_erp_action *erp_action)
537 {
538 	init_timer(&erp_action->timer);
539 	erp_action->timer.function = zfcp_erp_memwait_handler;
540 	erp_action->timer.data = (unsigned long) erp_action;
541 	erp_action->timer.expires = jiffies + HZ;
542 	add_timer(&erp_action->timer);
543 }
544 
545 static void _zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter,
546 				      int clear, char *id, void *ref)
547 {
548 	struct zfcp_port *port;
549 
550 	read_lock(&adapter->port_list_lock);
551 	list_for_each_entry(port, &adapter->port_list, list)
552 		_zfcp_erp_port_reopen(port, clear, id, ref);
553 	read_unlock(&adapter->port_list_lock);
554 }
555 
556 static void _zfcp_erp_unit_reopen_all(struct zfcp_port *port, int clear,
557 				      char *id, void *ref)
558 {
559 	struct zfcp_unit *unit;
560 
561 	read_lock(&port->unit_list_lock);
562 	list_for_each_entry(unit, &port->unit_list, list)
563 		_zfcp_erp_unit_reopen(unit, clear, id, ref);
564 	read_unlock(&port->unit_list_lock);
565 }
566 
567 static void zfcp_erp_strategy_followup_failed(struct zfcp_erp_action *act)
568 {
569 	switch (act->action) {
570 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
571 		_zfcp_erp_adapter_reopen(act->adapter, 0, "ersff_1", NULL);
572 		break;
573 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
574 		_zfcp_erp_port_forced_reopen(act->port, 0, "ersff_2", NULL);
575 		break;
576 	case ZFCP_ERP_ACTION_REOPEN_PORT:
577 		_zfcp_erp_port_reopen(act->port, 0, "ersff_3", NULL);
578 		break;
579 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
580 		_zfcp_erp_unit_reopen(act->unit, 0, "ersff_4", NULL);
581 		break;
582 	}
583 }
584 
585 static void zfcp_erp_strategy_followup_success(struct zfcp_erp_action *act)
586 {
587 	switch (act->action) {
588 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
589 		_zfcp_erp_port_reopen_all(act->adapter, 0, "ersfs_1", NULL);
590 		break;
591 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
592 		_zfcp_erp_port_reopen(act->port, 0, "ersfs_2", NULL);
593 		break;
594 	case ZFCP_ERP_ACTION_REOPEN_PORT:
595 		_zfcp_erp_unit_reopen_all(act->port, 0, "ersfs_3", NULL);
596 		break;
597 	}
598 }
599 
600 static void zfcp_erp_wakeup(struct zfcp_adapter *adapter)
601 {
602 	unsigned long flags;
603 
604 	read_lock_irqsave(&adapter->erp_lock, flags);
605 	if (list_empty(&adapter->erp_ready_head) &&
606 	    list_empty(&adapter->erp_running_head)) {
607 			atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_PENDING,
608 					  &adapter->status);
609 			wake_up(&adapter->erp_done_wqh);
610 	}
611 	read_unlock_irqrestore(&adapter->erp_lock, flags);
612 }
613 
614 static int zfcp_erp_adapter_strategy_open_qdio(struct zfcp_erp_action *act)
615 {
616 	struct zfcp_qdio *qdio = act->adapter->qdio;
617 
618 	if (zfcp_qdio_open(qdio))
619 		return ZFCP_ERP_FAILED;
620 	init_waitqueue_head(&qdio->req_q_wq);
621 	atomic_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &act->adapter->status);
622 	return ZFCP_ERP_SUCCEEDED;
623 }
624 
625 static void zfcp_erp_enqueue_ptp_port(struct zfcp_adapter *adapter)
626 {
627 	struct zfcp_port *port;
628 	port = zfcp_port_enqueue(adapter, adapter->peer_wwpn, 0,
629 				 adapter->peer_d_id);
630 	if (IS_ERR(port)) /* error or port already attached */
631 		return;
632 	_zfcp_erp_port_reopen(port, 0, "ereptp1", NULL);
633 }
634 
635 static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
636 {
637 	int retries;
638 	int sleep = 1;
639 	struct zfcp_adapter *adapter = erp_action->adapter;
640 
641 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
642 
643 	for (retries = 7; retries; retries--) {
644 		atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
645 				  &adapter->status);
646 		write_lock_irq(&adapter->erp_lock);
647 		zfcp_erp_action_to_running(erp_action);
648 		write_unlock_irq(&adapter->erp_lock);
649 		if (zfcp_fsf_exchange_config_data(erp_action)) {
650 			atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
651 					  &adapter->status);
652 			return ZFCP_ERP_FAILED;
653 		}
654 
655 		zfcp_dbf_rec_thread_lock("erasfx1", adapter->dbf);
656 		wait_event(adapter->erp_ready_wq,
657 			   !list_empty(&adapter->erp_ready_head));
658 		zfcp_dbf_rec_thread_lock("erasfx2", adapter->dbf);
659 		if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
660 			break;
661 
662 		if (!(atomic_read(&adapter->status) &
663 		      ZFCP_STATUS_ADAPTER_HOST_CON_INIT))
664 			break;
665 
666 		ssleep(sleep);
667 		sleep *= 2;
668 	}
669 
670 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
671 			  &adapter->status);
672 
673 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
674 		return ZFCP_ERP_FAILED;
675 
676 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
677 		zfcp_erp_enqueue_ptp_port(adapter);
678 
679 	return ZFCP_ERP_SUCCEEDED;
680 }
681 
682 static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
683 {
684 	int ret;
685 	struct zfcp_adapter *adapter = act->adapter;
686 
687 	write_lock_irq(&adapter->erp_lock);
688 	zfcp_erp_action_to_running(act);
689 	write_unlock_irq(&adapter->erp_lock);
690 
691 	ret = zfcp_fsf_exchange_port_data(act);
692 	if (ret == -EOPNOTSUPP)
693 		return ZFCP_ERP_SUCCEEDED;
694 	if (ret)
695 		return ZFCP_ERP_FAILED;
696 
697 	zfcp_dbf_rec_thread_lock("erasox1", adapter->dbf);
698 	wait_event(adapter->erp_ready_wq,
699 		   !list_empty(&adapter->erp_ready_head));
700 	zfcp_dbf_rec_thread_lock("erasox2", adapter->dbf);
701 	if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
702 		return ZFCP_ERP_FAILED;
703 
704 	return ZFCP_ERP_SUCCEEDED;
705 }
706 
707 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
708 {
709 	if (zfcp_erp_adapter_strat_fsf_xconf(act) == ZFCP_ERP_FAILED)
710 		return ZFCP_ERP_FAILED;
711 
712 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
713 		return ZFCP_ERP_FAILED;
714 
715 	atomic_set(&act->adapter->stat_miss, 16);
716 	if (zfcp_status_read_refill(act->adapter))
717 		return ZFCP_ERP_FAILED;
718 
719 	return ZFCP_ERP_SUCCEEDED;
720 }
721 
722 static void zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *act)
723 {
724 	struct zfcp_adapter *adapter = act->adapter;
725 
726 	/* close queues to ensure that buffers are not accessed by adapter */
727 	zfcp_qdio_close(adapter->qdio);
728 	zfcp_fsf_req_dismiss_all(adapter);
729 	adapter->fsf_req_seq_no = 0;
730 	zfcp_fc_wka_ports_force_offline(adapter->gs);
731 	/* all ports and units are closed */
732 	zfcp_erp_modify_adapter_status(adapter, "erascl1", NULL,
733 				       ZFCP_STATUS_COMMON_OPEN, ZFCP_CLEAR);
734 
735 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
736 			  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
737 }
738 
739 static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *act)
740 {
741 	struct zfcp_adapter *adapter = act->adapter;
742 
743 	if (zfcp_erp_adapter_strategy_open_qdio(act)) {
744 		atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
745 				  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
746 				  &adapter->status);
747 		return ZFCP_ERP_FAILED;
748 	}
749 
750 	if (zfcp_erp_adapter_strategy_open_fsf(act)) {
751 		zfcp_erp_adapter_strategy_close(act);
752 		return ZFCP_ERP_FAILED;
753 	}
754 
755 	atomic_set_mask(ZFCP_STATUS_COMMON_OPEN, &adapter->status);
756 
757 	return ZFCP_ERP_SUCCEEDED;
758 }
759 
760 static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *act)
761 {
762 	struct zfcp_adapter *adapter = act->adapter;
763 
764 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_OPEN) {
765 		zfcp_erp_adapter_strategy_close(act);
766 		if (act->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
767 			return ZFCP_ERP_EXIT;
768 	}
769 
770 	if (zfcp_erp_adapter_strategy_open(act)) {
771 		ssleep(8);
772 		return ZFCP_ERP_FAILED;
773 	}
774 
775 	return ZFCP_ERP_SUCCEEDED;
776 }
777 
778 static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
779 {
780 	int retval;
781 
782 	retval = zfcp_fsf_close_physical_port(act);
783 	if (retval == -ENOMEM)
784 		return ZFCP_ERP_NOMEM;
785 	act->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
786 	if (retval)
787 		return ZFCP_ERP_FAILED;
788 
789 	return ZFCP_ERP_CONTINUES;
790 }
791 
792 static void zfcp_erp_port_strategy_clearstati(struct zfcp_port *port)
793 {
794 	atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED, &port->status);
795 }
796 
797 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
798 {
799 	struct zfcp_port *port = erp_action->port;
800 	int status = atomic_read(&port->status);
801 
802 	switch (erp_action->step) {
803 	case ZFCP_ERP_STEP_UNINITIALIZED:
804 		zfcp_erp_port_strategy_clearstati(port);
805 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
806 		    (status & ZFCP_STATUS_COMMON_OPEN))
807 			return zfcp_erp_port_forced_strategy_close(erp_action);
808 		else
809 			return ZFCP_ERP_FAILED;
810 
811 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
812 		if (!(status & ZFCP_STATUS_PORT_PHYS_OPEN))
813 			return ZFCP_ERP_SUCCEEDED;
814 	}
815 	return ZFCP_ERP_FAILED;
816 }
817 
818 static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
819 {
820 	int retval;
821 
822 	retval = zfcp_fsf_close_port(erp_action);
823 	if (retval == -ENOMEM)
824 		return ZFCP_ERP_NOMEM;
825 	erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
826 	if (retval)
827 		return ZFCP_ERP_FAILED;
828 	return ZFCP_ERP_CONTINUES;
829 }
830 
831 static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
832 {
833 	int retval;
834 
835 	retval = zfcp_fsf_open_port(erp_action);
836 	if (retval == -ENOMEM)
837 		return ZFCP_ERP_NOMEM;
838 	erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
839 	if (retval)
840 		return ZFCP_ERP_FAILED;
841 	return ZFCP_ERP_CONTINUES;
842 }
843 
844 static int zfcp_erp_open_ptp_port(struct zfcp_erp_action *act)
845 {
846 	struct zfcp_adapter *adapter = act->adapter;
847 	struct zfcp_port *port = act->port;
848 
849 	if (port->wwpn != adapter->peer_wwpn) {
850 		zfcp_erp_port_failed(port, "eroptp1", NULL);
851 		return ZFCP_ERP_FAILED;
852 	}
853 	port->d_id = adapter->peer_d_id;
854 	return zfcp_erp_port_strategy_open_port(act);
855 }
856 
857 static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *act)
858 {
859 	struct zfcp_adapter *adapter = act->adapter;
860 	struct zfcp_port *port = act->port;
861 	int p_status = atomic_read(&port->status);
862 
863 	switch (act->step) {
864 	case ZFCP_ERP_STEP_UNINITIALIZED:
865 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
866 	case ZFCP_ERP_STEP_PORT_CLOSING:
867 		if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
868 			return zfcp_erp_open_ptp_port(act);
869 		if (!port->d_id) {
870 			zfcp_fc_trigger_did_lookup(port);
871 			return ZFCP_ERP_EXIT;
872 		}
873 		return zfcp_erp_port_strategy_open_port(act);
874 
875 	case ZFCP_ERP_STEP_PORT_OPENING:
876 		/* D_ID might have changed during open */
877 		if (p_status & ZFCP_STATUS_COMMON_OPEN) {
878 			if (!port->d_id) {
879 				zfcp_fc_trigger_did_lookup(port);
880 				return ZFCP_ERP_EXIT;
881 			}
882 			return ZFCP_ERP_SUCCEEDED;
883 		}
884 		if (port->d_id && !(p_status & ZFCP_STATUS_COMMON_NOESC)) {
885 			port->d_id = 0;
886 			_zfcp_erp_port_reopen(port, 0, "erpsoc1", NULL);
887 			return ZFCP_ERP_EXIT;
888 		}
889 		/* fall through otherwise */
890 	}
891 	return ZFCP_ERP_FAILED;
892 }
893 
894 static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
895 {
896 	struct zfcp_port *port = erp_action->port;
897 	int p_status = atomic_read(&port->status);
898 
899 	if ((p_status & ZFCP_STATUS_COMMON_NOESC) &&
900 	    !(p_status & ZFCP_STATUS_COMMON_OPEN))
901 		goto close_init_done;
902 
903 	switch (erp_action->step) {
904 	case ZFCP_ERP_STEP_UNINITIALIZED:
905 		zfcp_erp_port_strategy_clearstati(port);
906 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
907 			return zfcp_erp_port_strategy_close(erp_action);
908 		break;
909 
910 	case ZFCP_ERP_STEP_PORT_CLOSING:
911 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
912 			return ZFCP_ERP_FAILED;
913 		break;
914 	}
915 
916 close_init_done:
917 	if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
918 		return ZFCP_ERP_EXIT;
919 
920 	return zfcp_erp_port_strategy_open_common(erp_action);
921 }
922 
923 static void zfcp_erp_unit_strategy_clearstati(struct zfcp_unit *unit)
924 {
925 	atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED |
926 			  ZFCP_STATUS_UNIT_SHARED |
927 			  ZFCP_STATUS_UNIT_READONLY,
928 			  &unit->status);
929 }
930 
931 static int zfcp_erp_unit_strategy_close(struct zfcp_erp_action *erp_action)
932 {
933 	int retval = zfcp_fsf_close_unit(erp_action);
934 	if (retval == -ENOMEM)
935 		return ZFCP_ERP_NOMEM;
936 	erp_action->step = ZFCP_ERP_STEP_UNIT_CLOSING;
937 	if (retval)
938 		return ZFCP_ERP_FAILED;
939 	return ZFCP_ERP_CONTINUES;
940 }
941 
942 static int zfcp_erp_unit_strategy_open(struct zfcp_erp_action *erp_action)
943 {
944 	int retval = zfcp_fsf_open_unit(erp_action);
945 	if (retval == -ENOMEM)
946 		return ZFCP_ERP_NOMEM;
947 	erp_action->step = ZFCP_ERP_STEP_UNIT_OPENING;
948 	if (retval)
949 		return  ZFCP_ERP_FAILED;
950 	return ZFCP_ERP_CONTINUES;
951 }
952 
953 static int zfcp_erp_unit_strategy(struct zfcp_erp_action *erp_action)
954 {
955 	struct zfcp_unit *unit = erp_action->unit;
956 
957 	switch (erp_action->step) {
958 	case ZFCP_ERP_STEP_UNINITIALIZED:
959 		zfcp_erp_unit_strategy_clearstati(unit);
960 		if (atomic_read(&unit->status) & ZFCP_STATUS_COMMON_OPEN)
961 			return zfcp_erp_unit_strategy_close(erp_action);
962 		/* already closed, fall through */
963 	case ZFCP_ERP_STEP_UNIT_CLOSING:
964 		if (atomic_read(&unit->status) & ZFCP_STATUS_COMMON_OPEN)
965 			return ZFCP_ERP_FAILED;
966 		if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
967 			return ZFCP_ERP_EXIT;
968 		return zfcp_erp_unit_strategy_open(erp_action);
969 
970 	case ZFCP_ERP_STEP_UNIT_OPENING:
971 		if (atomic_read(&unit->status) & ZFCP_STATUS_COMMON_OPEN)
972 			return ZFCP_ERP_SUCCEEDED;
973 	}
974 	return ZFCP_ERP_FAILED;
975 }
976 
977 static int zfcp_erp_strategy_check_unit(struct zfcp_unit *unit, int result)
978 {
979 	switch (result) {
980 	case ZFCP_ERP_SUCCEEDED :
981 		atomic_set(&unit->erp_counter, 0);
982 		zfcp_erp_unit_unblock(unit);
983 		break;
984 	case ZFCP_ERP_FAILED :
985 		atomic_inc(&unit->erp_counter);
986 		if (atomic_read(&unit->erp_counter) > ZFCP_MAX_ERPS) {
987 			dev_err(&unit->port->adapter->ccw_device->dev,
988 				"ERP failed for unit 0x%016Lx on "
989 				"port 0x%016Lx\n",
990 				(unsigned long long)unit->fcp_lun,
991 				(unsigned long long)unit->port->wwpn);
992 			zfcp_erp_unit_failed(unit, "erusck1", NULL);
993 		}
994 		break;
995 	}
996 
997 	if (atomic_read(&unit->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
998 		zfcp_erp_unit_block(unit, 0);
999 		result = ZFCP_ERP_EXIT;
1000 	}
1001 	return result;
1002 }
1003 
1004 static int zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
1005 {
1006 	switch (result) {
1007 	case ZFCP_ERP_SUCCEEDED :
1008 		atomic_set(&port->erp_counter, 0);
1009 		zfcp_erp_port_unblock(port);
1010 		break;
1011 
1012 	case ZFCP_ERP_FAILED :
1013 		if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC) {
1014 			zfcp_erp_port_block(port, 0);
1015 			result = ZFCP_ERP_EXIT;
1016 		}
1017 		atomic_inc(&port->erp_counter);
1018 		if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS) {
1019 			dev_err(&port->adapter->ccw_device->dev,
1020 				"ERP failed for remote port 0x%016Lx\n",
1021 				(unsigned long long)port->wwpn);
1022 			zfcp_erp_port_failed(port, "erpsck1", NULL);
1023 		}
1024 		break;
1025 	}
1026 
1027 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1028 		zfcp_erp_port_block(port, 0);
1029 		result = ZFCP_ERP_EXIT;
1030 	}
1031 	return result;
1032 }
1033 
1034 static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter,
1035 					   int result)
1036 {
1037 	switch (result) {
1038 	case ZFCP_ERP_SUCCEEDED :
1039 		atomic_set(&adapter->erp_counter, 0);
1040 		zfcp_erp_adapter_unblock(adapter);
1041 		break;
1042 
1043 	case ZFCP_ERP_FAILED :
1044 		atomic_inc(&adapter->erp_counter);
1045 		if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS) {
1046 			dev_err(&adapter->ccw_device->dev,
1047 				"ERP cannot recover an error "
1048 				"on the FCP device\n");
1049 			zfcp_erp_adapter_failed(adapter, "erasck1", NULL);
1050 		}
1051 		break;
1052 	}
1053 
1054 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1055 		zfcp_erp_adapter_block(adapter, 0);
1056 		result = ZFCP_ERP_EXIT;
1057 	}
1058 	return result;
1059 }
1060 
1061 static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action,
1062 					  int result)
1063 {
1064 	struct zfcp_adapter *adapter = erp_action->adapter;
1065 	struct zfcp_port *port = erp_action->port;
1066 	struct zfcp_unit *unit = erp_action->unit;
1067 
1068 	switch (erp_action->action) {
1069 
1070 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
1071 		result = zfcp_erp_strategy_check_unit(unit, result);
1072 		break;
1073 
1074 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1075 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1076 		result = zfcp_erp_strategy_check_port(port, result);
1077 		break;
1078 
1079 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1080 		result = zfcp_erp_strategy_check_adapter(adapter, result);
1081 		break;
1082 	}
1083 	return result;
1084 }
1085 
1086 static int zfcp_erp_strat_change_det(atomic_t *target_status, u32 erp_status)
1087 {
1088 	int status = atomic_read(target_status);
1089 
1090 	if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
1091 	    (erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1092 		return 1; /* take it online */
1093 
1094 	if (!(status & ZFCP_STATUS_COMMON_RUNNING) &&
1095 	    !(erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1096 		return 1; /* take it offline */
1097 
1098 	return 0;
1099 }
1100 
1101 static int zfcp_erp_strategy_statechange(struct zfcp_erp_action *act, int ret)
1102 {
1103 	int action = act->action;
1104 	struct zfcp_adapter *adapter = act->adapter;
1105 	struct zfcp_port *port = act->port;
1106 	struct zfcp_unit *unit = act->unit;
1107 	u32 erp_status = act->status;
1108 
1109 	switch (action) {
1110 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1111 		if (zfcp_erp_strat_change_det(&adapter->status, erp_status)) {
1112 			_zfcp_erp_adapter_reopen(adapter,
1113 						 ZFCP_STATUS_COMMON_ERP_FAILED,
1114 						 "ersscg1", NULL);
1115 			return ZFCP_ERP_EXIT;
1116 		}
1117 		break;
1118 
1119 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1120 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1121 		if (zfcp_erp_strat_change_det(&port->status, erp_status)) {
1122 			_zfcp_erp_port_reopen(port,
1123 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1124 					      "ersscg2", NULL);
1125 			return ZFCP_ERP_EXIT;
1126 		}
1127 		break;
1128 
1129 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
1130 		if (zfcp_erp_strat_change_det(&unit->status, erp_status)) {
1131 			_zfcp_erp_unit_reopen(unit,
1132 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1133 					      "ersscg3", NULL);
1134 			return ZFCP_ERP_EXIT;
1135 		}
1136 		break;
1137 	}
1138 	return ret;
1139 }
1140 
1141 static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
1142 {
1143 	struct zfcp_adapter *adapter = erp_action->adapter;
1144 
1145 	adapter->erp_total_count--;
1146 	if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1147 		adapter->erp_low_mem_count--;
1148 		erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1149 	}
1150 
1151 	list_del(&erp_action->list);
1152 	zfcp_dbf_rec_action("eractd1", erp_action);
1153 
1154 	switch (erp_action->action) {
1155 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
1156 		atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
1157 				  &erp_action->unit->status);
1158 		break;
1159 
1160 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1161 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1162 		atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
1163 				  &erp_action->port->status);
1164 		break;
1165 
1166 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1167 		atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
1168 				  &erp_action->adapter->status);
1169 		break;
1170 	}
1171 }
1172 
1173 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
1174 {
1175 	struct zfcp_adapter *adapter = act->adapter;
1176 	struct zfcp_port *port = act->port;
1177 	struct zfcp_unit *unit = act->unit;
1178 
1179 	switch (act->action) {
1180 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
1181 		if ((result == ZFCP_ERP_SUCCEEDED) && !unit->device) {
1182 			get_device(&unit->sysfs_device);
1183 			if (scsi_queue_work(unit->port->adapter->scsi_host,
1184 					    &unit->scsi_work) <= 0)
1185 				put_device(&unit->sysfs_device);
1186 		}
1187 		put_device(&unit->sysfs_device);
1188 		break;
1189 
1190 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1191 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1192 		if (result == ZFCP_ERP_SUCCEEDED)
1193 			zfcp_scsi_schedule_rport_register(port);
1194 		put_device(&port->sysfs_device);
1195 		break;
1196 
1197 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1198 		if (result == ZFCP_ERP_SUCCEEDED) {
1199 			register_service_level(&adapter->service_level);
1200 			queue_work(adapter->work_queue, &adapter->scan_work);
1201 		} else
1202 			unregister_service_level(&adapter->service_level);
1203 		kref_put(&adapter->ref, zfcp_adapter_release);
1204 		break;
1205 	}
1206 }
1207 
1208 static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
1209 {
1210 	switch (erp_action->action) {
1211 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1212 		return zfcp_erp_adapter_strategy(erp_action);
1213 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1214 		return zfcp_erp_port_forced_strategy(erp_action);
1215 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1216 		return zfcp_erp_port_strategy(erp_action);
1217 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
1218 		return zfcp_erp_unit_strategy(erp_action);
1219 	}
1220 	return ZFCP_ERP_FAILED;
1221 }
1222 
1223 static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
1224 {
1225 	int retval;
1226 	unsigned long flags;
1227 	struct zfcp_adapter *adapter = erp_action->adapter;
1228 
1229 	kref_get(&adapter->ref);
1230 
1231 	write_lock_irqsave(&adapter->erp_lock, flags);
1232 	zfcp_erp_strategy_check_fsfreq(erp_action);
1233 
1234 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
1235 		zfcp_erp_action_dequeue(erp_action);
1236 		retval = ZFCP_ERP_DISMISSED;
1237 		goto unlock;
1238 	}
1239 
1240 	zfcp_erp_action_to_running(erp_action);
1241 
1242 	/* no lock to allow for blocking operations */
1243 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1244 	retval = zfcp_erp_strategy_do_action(erp_action);
1245 	write_lock_irqsave(&adapter->erp_lock, flags);
1246 
1247 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
1248 		retval = ZFCP_ERP_CONTINUES;
1249 
1250 	switch (retval) {
1251 	case ZFCP_ERP_NOMEM:
1252 		if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
1253 			++adapter->erp_low_mem_count;
1254 			erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
1255 		}
1256 		if (adapter->erp_total_count == adapter->erp_low_mem_count)
1257 			_zfcp_erp_adapter_reopen(adapter, 0, "erstgy1", NULL);
1258 		else {
1259 			zfcp_erp_strategy_memwait(erp_action);
1260 			retval = ZFCP_ERP_CONTINUES;
1261 		}
1262 		goto unlock;
1263 
1264 	case ZFCP_ERP_CONTINUES:
1265 		if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1266 			--adapter->erp_low_mem_count;
1267 			erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1268 		}
1269 		goto unlock;
1270 	}
1271 
1272 	retval = zfcp_erp_strategy_check_target(erp_action, retval);
1273 	zfcp_erp_action_dequeue(erp_action);
1274 	retval = zfcp_erp_strategy_statechange(erp_action, retval);
1275 	if (retval == ZFCP_ERP_EXIT)
1276 		goto unlock;
1277 	if (retval == ZFCP_ERP_SUCCEEDED)
1278 		zfcp_erp_strategy_followup_success(erp_action);
1279 	if (retval == ZFCP_ERP_FAILED)
1280 		zfcp_erp_strategy_followup_failed(erp_action);
1281 
1282  unlock:
1283 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1284 
1285 	if (retval != ZFCP_ERP_CONTINUES)
1286 		zfcp_erp_action_cleanup(erp_action, retval);
1287 
1288 	kref_put(&adapter->ref, zfcp_adapter_release);
1289 	return retval;
1290 }
1291 
1292 static int zfcp_erp_thread(void *data)
1293 {
1294 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
1295 	struct list_head *next;
1296 	struct zfcp_erp_action *act;
1297 	unsigned long flags;
1298 
1299 	for (;;) {
1300 		zfcp_dbf_rec_thread_lock("erthrd1", adapter->dbf);
1301 		wait_event_interruptible(adapter->erp_ready_wq,
1302 			   !list_empty(&adapter->erp_ready_head) ||
1303 			   kthread_should_stop());
1304 		zfcp_dbf_rec_thread_lock("erthrd2", adapter->dbf);
1305 
1306 		if (kthread_should_stop())
1307 			break;
1308 
1309 		write_lock_irqsave(&adapter->erp_lock, flags);
1310 		next = adapter->erp_ready_head.next;
1311 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1312 
1313 		if (next != &adapter->erp_ready_head) {
1314 			act = list_entry(next, struct zfcp_erp_action, list);
1315 
1316 			/* there is more to come after dismission, no notify */
1317 			if (zfcp_erp_strategy(act) != ZFCP_ERP_DISMISSED)
1318 				zfcp_erp_wakeup(adapter);
1319 		}
1320 	}
1321 
1322 	return 0;
1323 }
1324 
1325 /**
1326  * zfcp_erp_thread_setup - Start ERP thread for adapter
1327  * @adapter: Adapter to start the ERP thread for
1328  *
1329  * Returns 0 on success or error code from kernel_thread()
1330  */
1331 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
1332 {
1333 	struct task_struct *thread;
1334 
1335 	thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
1336 			     dev_name(&adapter->ccw_device->dev));
1337 	if (IS_ERR(thread)) {
1338 		dev_err(&adapter->ccw_device->dev,
1339 			"Creating an ERP thread for the FCP device failed.\n");
1340 		return PTR_ERR(thread);
1341 	}
1342 
1343 	adapter->erp_thread = thread;
1344 	return 0;
1345 }
1346 
1347 /**
1348  * zfcp_erp_thread_kill - Stop ERP thread.
1349  * @adapter: Adapter where the ERP thread should be stopped.
1350  *
1351  * The caller of this routine ensures that the specified adapter has
1352  * been shut down and that this operation has been completed. Thus,
1353  * there are no pending erp_actions which would need to be handled
1354  * here.
1355  */
1356 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
1357 {
1358 	kthread_stop(adapter->erp_thread);
1359 	adapter->erp_thread = NULL;
1360 	WARN_ON(!list_empty(&adapter->erp_ready_head));
1361 	WARN_ON(!list_empty(&adapter->erp_running_head));
1362 }
1363 
1364 /**
1365  * zfcp_erp_adapter_failed - Set adapter status to failed.
1366  * @adapter: Failed adapter.
1367  * @id: Event id for debug trace.
1368  * @ref: Reference for debug trace.
1369  */
1370 void zfcp_erp_adapter_failed(struct zfcp_adapter *adapter, char *id, void *ref)
1371 {
1372 	zfcp_erp_modify_adapter_status(adapter, id, ref,
1373 				       ZFCP_STATUS_COMMON_ERP_FAILED, ZFCP_SET);
1374 }
1375 
1376 /**
1377  * zfcp_erp_port_failed - Set port status to failed.
1378  * @port: Failed port.
1379  * @id: Event id for debug trace.
1380  * @ref: Reference for debug trace.
1381  */
1382 void zfcp_erp_port_failed(struct zfcp_port *port, char *id, void *ref)
1383 {
1384 	zfcp_erp_modify_port_status(port, id, ref,
1385 				    ZFCP_STATUS_COMMON_ERP_FAILED, ZFCP_SET);
1386 }
1387 
1388 /**
1389  * zfcp_erp_unit_failed - Set unit status to failed.
1390  * @unit: Failed unit.
1391  * @id: Event id for debug trace.
1392  * @ref: Reference for debug trace.
1393  */
1394 void zfcp_erp_unit_failed(struct zfcp_unit *unit, char *id, void *ref)
1395 {
1396 	zfcp_erp_modify_unit_status(unit, id, ref,
1397 				    ZFCP_STATUS_COMMON_ERP_FAILED, ZFCP_SET);
1398 }
1399 
1400 /**
1401  * zfcp_erp_wait - wait for completion of error recovery on an adapter
1402  * @adapter: adapter for which to wait for completion of its error recovery
1403  */
1404 void zfcp_erp_wait(struct zfcp_adapter *adapter)
1405 {
1406 	wait_event(adapter->erp_done_wqh,
1407 		   !(atomic_read(&adapter->status) &
1408 			ZFCP_STATUS_ADAPTER_ERP_PENDING));
1409 }
1410 
1411 /**
1412  * zfcp_erp_modify_adapter_status - change adapter status bits
1413  * @adapter: adapter to change the status
1414  * @id: id for the debug trace
1415  * @ref: reference for the debug trace
1416  * @mask: status bits to change
1417  * @set_or_clear: ZFCP_SET or ZFCP_CLEAR
1418  *
1419  * Changes in common status bits are propagated to attached ports and units.
1420  */
1421 void zfcp_erp_modify_adapter_status(struct zfcp_adapter *adapter, char *id,
1422 				    void *ref, u32 mask, int set_or_clear)
1423 {
1424 	struct zfcp_port *port;
1425 	unsigned long flags;
1426 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1427 
1428 	if (set_or_clear == ZFCP_SET) {
1429 		if (status_change_set(mask, &adapter->status))
1430 			zfcp_dbf_rec_adapter(id, ref, adapter->dbf);
1431 		atomic_set_mask(mask, &adapter->status);
1432 	} else {
1433 		if (status_change_clear(mask, &adapter->status))
1434 			zfcp_dbf_rec_adapter(id, ref, adapter->dbf);
1435 		atomic_clear_mask(mask, &adapter->status);
1436 		if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1437 			atomic_set(&adapter->erp_counter, 0);
1438 	}
1439 
1440 	if (common_mask) {
1441 		read_lock_irqsave(&adapter->port_list_lock, flags);
1442 		list_for_each_entry(port, &adapter->port_list, list)
1443 			zfcp_erp_modify_port_status(port, id, ref, common_mask,
1444 						    set_or_clear);
1445 		read_unlock_irqrestore(&adapter->port_list_lock, flags);
1446 	}
1447 }
1448 
1449 /**
1450  * zfcp_erp_modify_port_status - change port status bits
1451  * @port: port to change the status bits
1452  * @id: id for the debug trace
1453  * @ref: reference for the debug trace
1454  * @mask: status bits to change
1455  * @set_or_clear: ZFCP_SET or ZFCP_CLEAR
1456  *
1457  * Changes in common status bits are propagated to attached units.
1458  */
1459 void zfcp_erp_modify_port_status(struct zfcp_port *port, char *id, void *ref,
1460 				 u32 mask, int set_or_clear)
1461 {
1462 	struct zfcp_unit *unit;
1463 	unsigned long flags;
1464 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1465 
1466 	if (set_or_clear == ZFCP_SET) {
1467 		if (status_change_set(mask, &port->status))
1468 			zfcp_dbf_rec_port(id, ref, port);
1469 		atomic_set_mask(mask, &port->status);
1470 	} else {
1471 		if (status_change_clear(mask, &port->status))
1472 			zfcp_dbf_rec_port(id, ref, port);
1473 		atomic_clear_mask(mask, &port->status);
1474 		if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1475 			atomic_set(&port->erp_counter, 0);
1476 	}
1477 
1478 	if (common_mask) {
1479 		read_lock_irqsave(&port->unit_list_lock, flags);
1480 		list_for_each_entry(unit, &port->unit_list, list)
1481 			zfcp_erp_modify_unit_status(unit, id, ref, common_mask,
1482 						    set_or_clear);
1483 		read_unlock_irqrestore(&port->unit_list_lock, flags);
1484 	}
1485 }
1486 
1487 /**
1488  * zfcp_erp_modify_unit_status - change unit status bits
1489  * @unit: unit to change the status bits
1490  * @id: id for the debug trace
1491  * @ref: reference for the debug trace
1492  * @mask: status bits to change
1493  * @set_or_clear: ZFCP_SET or ZFCP_CLEAR
1494  */
1495 void zfcp_erp_modify_unit_status(struct zfcp_unit *unit, char *id, void *ref,
1496 				 u32 mask, int set_or_clear)
1497 {
1498 	if (set_or_clear == ZFCP_SET) {
1499 		if (status_change_set(mask, &unit->status))
1500 			zfcp_dbf_rec_unit(id, ref, unit);
1501 		atomic_set_mask(mask, &unit->status);
1502 	} else {
1503 		if (status_change_clear(mask, &unit->status))
1504 			zfcp_dbf_rec_unit(id, ref, unit);
1505 		atomic_clear_mask(mask, &unit->status);
1506 		if (mask & ZFCP_STATUS_COMMON_ERP_FAILED) {
1507 			atomic_set(&unit->erp_counter, 0);
1508 		}
1509 	}
1510 }
1511 
1512 /**
1513  * zfcp_erp_port_boxed - Mark port as "boxed" and start ERP
1514  * @port: The "boxed" port.
1515  * @id: The debug trace id.
1516  * @id: Reference for the debug trace.
1517  */
1518 void zfcp_erp_port_boxed(struct zfcp_port *port, char *id, void *ref)
1519 {
1520 	zfcp_erp_modify_port_status(port, id, ref,
1521 				    ZFCP_STATUS_COMMON_ACCESS_BOXED, ZFCP_SET);
1522 	zfcp_erp_port_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED, id, ref);
1523 }
1524 
1525 /**
1526  * zfcp_erp_unit_boxed - Mark unit as "boxed" and start ERP
1527  * @port: The "boxed" unit.
1528  * @id: The debug trace id.
1529  * @id: Reference for the debug trace.
1530  */
1531 void zfcp_erp_unit_boxed(struct zfcp_unit *unit, char *id, void *ref)
1532 {
1533 	zfcp_erp_modify_unit_status(unit, id, ref,
1534 				    ZFCP_STATUS_COMMON_ACCESS_BOXED, ZFCP_SET);
1535 	zfcp_erp_unit_reopen(unit, ZFCP_STATUS_COMMON_ERP_FAILED, id, ref);
1536 }
1537 
1538 /**
1539  * zfcp_erp_port_access_denied - Adapter denied access to port.
1540  * @port: port where access has been denied
1541  * @id: id for debug trace
1542  * @ref: reference for debug trace
1543  *
1544  * Since the adapter has denied access, stop using the port and the
1545  * attached units.
1546  */
1547 void zfcp_erp_port_access_denied(struct zfcp_port *port, char *id, void *ref)
1548 {
1549 	zfcp_erp_modify_port_status(port, id, ref,
1550 				    ZFCP_STATUS_COMMON_ERP_FAILED |
1551 				    ZFCP_STATUS_COMMON_ACCESS_DENIED, ZFCP_SET);
1552 }
1553 
1554 /**
1555  * zfcp_erp_unit_access_denied - Adapter denied access to unit.
1556  * @unit: unit where access has been denied
1557  * @id: id for debug trace
1558  * @ref: reference for debug trace
1559  *
1560  * Since the adapter has denied access, stop using the unit.
1561  */
1562 void zfcp_erp_unit_access_denied(struct zfcp_unit *unit, char *id, void *ref)
1563 {
1564 	zfcp_erp_modify_unit_status(unit, id, ref,
1565 				    ZFCP_STATUS_COMMON_ERP_FAILED |
1566 				    ZFCP_STATUS_COMMON_ACCESS_DENIED, ZFCP_SET);
1567 }
1568 
1569 static void zfcp_erp_unit_access_changed(struct zfcp_unit *unit, char *id,
1570 					 void *ref)
1571 {
1572 	int status = atomic_read(&unit->status);
1573 	if (!(status & (ZFCP_STATUS_COMMON_ACCESS_DENIED |
1574 			ZFCP_STATUS_COMMON_ACCESS_BOXED)))
1575 		return;
1576 
1577 	zfcp_erp_unit_reopen(unit, ZFCP_STATUS_COMMON_ERP_FAILED, id, ref);
1578 }
1579 
1580 static void zfcp_erp_port_access_changed(struct zfcp_port *port, char *id,
1581 					 void *ref)
1582 {
1583 	struct zfcp_unit *unit;
1584 	unsigned long flags;
1585 	int status = atomic_read(&port->status);
1586 
1587 	if (!(status & (ZFCP_STATUS_COMMON_ACCESS_DENIED |
1588 			ZFCP_STATUS_COMMON_ACCESS_BOXED))) {
1589 		read_lock_irqsave(&port->unit_list_lock, flags);
1590 		list_for_each_entry(unit, &port->unit_list, list)
1591 				    zfcp_erp_unit_access_changed(unit, id, ref);
1592 		read_unlock_irqrestore(&port->unit_list_lock, flags);
1593 		return;
1594 	}
1595 
1596 	zfcp_erp_port_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED, id, ref);
1597 }
1598 
1599 /**
1600  * zfcp_erp_adapter_access_changed - Process change in adapter ACT
1601  * @adapter: Adapter where the Access Control Table (ACT) changed
1602  * @id: Id for debug trace
1603  * @ref: Reference for debug trace
1604  */
1605 void zfcp_erp_adapter_access_changed(struct zfcp_adapter *adapter, char *id,
1606 				     void *ref)
1607 {
1608 	unsigned long flags;
1609 	struct zfcp_port *port;
1610 
1611 	if (adapter->connection_features & FSF_FEATURE_NPIV_MODE)
1612 		return;
1613 
1614 	read_lock_irqsave(&adapter->port_list_lock, flags);
1615 	list_for_each_entry(port, &adapter->port_list, list)
1616 		zfcp_erp_port_access_changed(port, id, ref);
1617 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1618 }
1619