xref: /openbmc/linux/drivers/s390/scsi/zfcp_erp.c (revision aac5987a)
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 	init_timer(&erp_action->timer);
576 	erp_action->timer.function = zfcp_erp_memwait_handler;
577 	erp_action->timer.data = (unsigned long) erp_action;
578 	erp_action->timer.expires = jiffies + HZ;
579 	add_timer(&erp_action->timer);
580 }
581 
582 static void _zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter,
583 				      int clear, char *id)
584 {
585 	struct zfcp_port *port;
586 
587 	read_lock(&adapter->port_list_lock);
588 	list_for_each_entry(port, &adapter->port_list, list)
589 		_zfcp_erp_port_reopen(port, clear, id);
590 	read_unlock(&adapter->port_list_lock);
591 }
592 
593 static void _zfcp_erp_lun_reopen_all(struct zfcp_port *port, int clear,
594 				     char *id)
595 {
596 	struct scsi_device *sdev;
597 
598 	spin_lock(port->adapter->scsi_host->host_lock);
599 	__shost_for_each_device(sdev, port->adapter->scsi_host)
600 		if (sdev_to_zfcp(sdev)->port == port)
601 			_zfcp_erp_lun_reopen(sdev, clear, id, 0);
602 	spin_unlock(port->adapter->scsi_host->host_lock);
603 }
604 
605 static void zfcp_erp_strategy_followup_failed(struct zfcp_erp_action *act)
606 {
607 	switch (act->action) {
608 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
609 		_zfcp_erp_adapter_reopen(act->adapter, 0, "ersff_1");
610 		break;
611 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
612 		_zfcp_erp_port_forced_reopen(act->port, 0, "ersff_2");
613 		break;
614 	case ZFCP_ERP_ACTION_REOPEN_PORT:
615 		_zfcp_erp_port_reopen(act->port, 0, "ersff_3");
616 		break;
617 	case ZFCP_ERP_ACTION_REOPEN_LUN:
618 		_zfcp_erp_lun_reopen(act->sdev, 0, "ersff_4", 0);
619 		break;
620 	}
621 }
622 
623 static void zfcp_erp_strategy_followup_success(struct zfcp_erp_action *act)
624 {
625 	switch (act->action) {
626 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
627 		_zfcp_erp_port_reopen_all(act->adapter, 0, "ersfs_1");
628 		break;
629 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
630 		_zfcp_erp_port_reopen(act->port, 0, "ersfs_2");
631 		break;
632 	case ZFCP_ERP_ACTION_REOPEN_PORT:
633 		_zfcp_erp_lun_reopen_all(act->port, 0, "ersfs_3");
634 		break;
635 	}
636 }
637 
638 static void zfcp_erp_wakeup(struct zfcp_adapter *adapter)
639 {
640 	unsigned long flags;
641 
642 	read_lock_irqsave(&adapter->erp_lock, flags);
643 	if (list_empty(&adapter->erp_ready_head) &&
644 	    list_empty(&adapter->erp_running_head)) {
645 			atomic_andnot(ZFCP_STATUS_ADAPTER_ERP_PENDING,
646 					  &adapter->status);
647 			wake_up(&adapter->erp_done_wqh);
648 	}
649 	read_unlock_irqrestore(&adapter->erp_lock, flags);
650 }
651 
652 static void zfcp_erp_enqueue_ptp_port(struct zfcp_adapter *adapter)
653 {
654 	struct zfcp_port *port;
655 	port = zfcp_port_enqueue(adapter, adapter->peer_wwpn, 0,
656 				 adapter->peer_d_id);
657 	if (IS_ERR(port)) /* error or port already attached */
658 		return;
659 	_zfcp_erp_port_reopen(port, 0, "ereptp1");
660 }
661 
662 static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
663 {
664 	int retries;
665 	int sleep = 1;
666 	struct zfcp_adapter *adapter = erp_action->adapter;
667 
668 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
669 
670 	for (retries = 7; retries; retries--) {
671 		atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
672 				  &adapter->status);
673 		write_lock_irq(&adapter->erp_lock);
674 		zfcp_erp_action_to_running(erp_action);
675 		write_unlock_irq(&adapter->erp_lock);
676 		if (zfcp_fsf_exchange_config_data(erp_action)) {
677 			atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
678 					  &adapter->status);
679 			return ZFCP_ERP_FAILED;
680 		}
681 
682 		wait_event(adapter->erp_ready_wq,
683 			   !list_empty(&adapter->erp_ready_head));
684 		if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
685 			break;
686 
687 		if (!(atomic_read(&adapter->status) &
688 		      ZFCP_STATUS_ADAPTER_HOST_CON_INIT))
689 			break;
690 
691 		ssleep(sleep);
692 		sleep *= 2;
693 	}
694 
695 	atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
696 			  &adapter->status);
697 
698 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
699 		return ZFCP_ERP_FAILED;
700 
701 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
702 		zfcp_erp_enqueue_ptp_port(adapter);
703 
704 	return ZFCP_ERP_SUCCEEDED;
705 }
706 
707 static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
708 {
709 	int ret;
710 	struct zfcp_adapter *adapter = act->adapter;
711 
712 	write_lock_irq(&adapter->erp_lock);
713 	zfcp_erp_action_to_running(act);
714 	write_unlock_irq(&adapter->erp_lock);
715 
716 	ret = zfcp_fsf_exchange_port_data(act);
717 	if (ret == -EOPNOTSUPP)
718 		return ZFCP_ERP_SUCCEEDED;
719 	if (ret)
720 		return ZFCP_ERP_FAILED;
721 
722 	zfcp_dbf_rec_run("erasox1", act);
723 	wait_event(adapter->erp_ready_wq,
724 		   !list_empty(&adapter->erp_ready_head));
725 	zfcp_dbf_rec_run("erasox2", act);
726 	if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
727 		return ZFCP_ERP_FAILED;
728 
729 	return ZFCP_ERP_SUCCEEDED;
730 }
731 
732 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
733 {
734 	if (zfcp_erp_adapter_strat_fsf_xconf(act) == ZFCP_ERP_FAILED)
735 		return ZFCP_ERP_FAILED;
736 
737 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
738 		return ZFCP_ERP_FAILED;
739 
740 	if (mempool_resize(act->adapter->pool.sr_data,
741 			   act->adapter->stat_read_buf_num))
742 		return ZFCP_ERP_FAILED;
743 
744 	if (mempool_resize(act->adapter->pool.status_read_req,
745 			   act->adapter->stat_read_buf_num))
746 		return ZFCP_ERP_FAILED;
747 
748 	atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
749 	if (zfcp_status_read_refill(act->adapter))
750 		return ZFCP_ERP_FAILED;
751 
752 	return ZFCP_ERP_SUCCEEDED;
753 }
754 
755 static void zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *act)
756 {
757 	struct zfcp_adapter *adapter = act->adapter;
758 
759 	/* close queues to ensure that buffers are not accessed by adapter */
760 	zfcp_qdio_close(adapter->qdio);
761 	zfcp_fsf_req_dismiss_all(adapter);
762 	adapter->fsf_req_seq_no = 0;
763 	zfcp_fc_wka_ports_force_offline(adapter->gs);
764 	/* all ports and LUNs are closed */
765 	zfcp_erp_clear_adapter_status(adapter, ZFCP_STATUS_COMMON_OPEN);
766 
767 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
768 			  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
769 }
770 
771 static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *act)
772 {
773 	struct zfcp_adapter *adapter = act->adapter;
774 
775 	if (zfcp_qdio_open(adapter->qdio)) {
776 		atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
777 				  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
778 				  &adapter->status);
779 		return ZFCP_ERP_FAILED;
780 	}
781 
782 	if (zfcp_erp_adapter_strategy_open_fsf(act)) {
783 		zfcp_erp_adapter_strategy_close(act);
784 		return ZFCP_ERP_FAILED;
785 	}
786 
787 	atomic_or(ZFCP_STATUS_COMMON_OPEN, &adapter->status);
788 
789 	return ZFCP_ERP_SUCCEEDED;
790 }
791 
792 static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *act)
793 {
794 	struct zfcp_adapter *adapter = act->adapter;
795 
796 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_OPEN) {
797 		zfcp_erp_adapter_strategy_close(act);
798 		if (act->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
799 			return ZFCP_ERP_EXIT;
800 	}
801 
802 	if (zfcp_erp_adapter_strategy_open(act)) {
803 		ssleep(8);
804 		return ZFCP_ERP_FAILED;
805 	}
806 
807 	return ZFCP_ERP_SUCCEEDED;
808 }
809 
810 static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
811 {
812 	int retval;
813 
814 	retval = zfcp_fsf_close_physical_port(act);
815 	if (retval == -ENOMEM)
816 		return ZFCP_ERP_NOMEM;
817 	act->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
818 	if (retval)
819 		return ZFCP_ERP_FAILED;
820 
821 	return ZFCP_ERP_CONTINUES;
822 }
823 
824 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
825 {
826 	struct zfcp_port *port = erp_action->port;
827 	int status = atomic_read(&port->status);
828 
829 	switch (erp_action->step) {
830 	case ZFCP_ERP_STEP_UNINITIALIZED:
831 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
832 		    (status & ZFCP_STATUS_COMMON_OPEN))
833 			return zfcp_erp_port_forced_strategy_close(erp_action);
834 		else
835 			return ZFCP_ERP_FAILED;
836 
837 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
838 		if (!(status & ZFCP_STATUS_PORT_PHYS_OPEN))
839 			return ZFCP_ERP_SUCCEEDED;
840 	}
841 	return ZFCP_ERP_FAILED;
842 }
843 
844 static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
845 {
846 	int retval;
847 
848 	retval = zfcp_fsf_close_port(erp_action);
849 	if (retval == -ENOMEM)
850 		return ZFCP_ERP_NOMEM;
851 	erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
852 	if (retval)
853 		return ZFCP_ERP_FAILED;
854 	return ZFCP_ERP_CONTINUES;
855 }
856 
857 static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
858 {
859 	int retval;
860 
861 	retval = zfcp_fsf_open_port(erp_action);
862 	if (retval == -ENOMEM)
863 		return ZFCP_ERP_NOMEM;
864 	erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
865 	if (retval)
866 		return ZFCP_ERP_FAILED;
867 	return ZFCP_ERP_CONTINUES;
868 }
869 
870 static int zfcp_erp_open_ptp_port(struct zfcp_erp_action *act)
871 {
872 	struct zfcp_adapter *adapter = act->adapter;
873 	struct zfcp_port *port = act->port;
874 
875 	if (port->wwpn != adapter->peer_wwpn) {
876 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
877 		return ZFCP_ERP_FAILED;
878 	}
879 	port->d_id = adapter->peer_d_id;
880 	return zfcp_erp_port_strategy_open_port(act);
881 }
882 
883 static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *act)
884 {
885 	struct zfcp_adapter *adapter = act->adapter;
886 	struct zfcp_port *port = act->port;
887 	int p_status = atomic_read(&port->status);
888 
889 	switch (act->step) {
890 	case ZFCP_ERP_STEP_UNINITIALIZED:
891 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
892 	case ZFCP_ERP_STEP_PORT_CLOSING:
893 		if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
894 			return zfcp_erp_open_ptp_port(act);
895 		if (!port->d_id) {
896 			zfcp_fc_trigger_did_lookup(port);
897 			return ZFCP_ERP_EXIT;
898 		}
899 		return zfcp_erp_port_strategy_open_port(act);
900 
901 	case ZFCP_ERP_STEP_PORT_OPENING:
902 		/* D_ID might have changed during open */
903 		if (p_status & ZFCP_STATUS_COMMON_OPEN) {
904 			if (!port->d_id) {
905 				zfcp_fc_trigger_did_lookup(port);
906 				return ZFCP_ERP_EXIT;
907 			}
908 			return ZFCP_ERP_SUCCEEDED;
909 		}
910 		if (port->d_id && !(p_status & ZFCP_STATUS_COMMON_NOESC)) {
911 			port->d_id = 0;
912 			return ZFCP_ERP_FAILED;
913 		}
914 		/* fall through otherwise */
915 	}
916 	return ZFCP_ERP_FAILED;
917 }
918 
919 static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
920 {
921 	struct zfcp_port *port = erp_action->port;
922 	int p_status = atomic_read(&port->status);
923 
924 	if ((p_status & ZFCP_STATUS_COMMON_NOESC) &&
925 	    !(p_status & ZFCP_STATUS_COMMON_OPEN))
926 		goto close_init_done;
927 
928 	switch (erp_action->step) {
929 	case ZFCP_ERP_STEP_UNINITIALIZED:
930 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
931 			return zfcp_erp_port_strategy_close(erp_action);
932 		break;
933 
934 	case ZFCP_ERP_STEP_PORT_CLOSING:
935 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
936 			return ZFCP_ERP_FAILED;
937 		break;
938 	}
939 
940 close_init_done:
941 	if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
942 		return ZFCP_ERP_EXIT;
943 
944 	return zfcp_erp_port_strategy_open_common(erp_action);
945 }
946 
947 static void zfcp_erp_lun_strategy_clearstati(struct scsi_device *sdev)
948 {
949 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
950 
951 	atomic_andnot(ZFCP_STATUS_COMMON_ACCESS_DENIED,
952 			  &zfcp_sdev->status);
953 }
954 
955 static int zfcp_erp_lun_strategy_close(struct zfcp_erp_action *erp_action)
956 {
957 	int retval = zfcp_fsf_close_lun(erp_action);
958 	if (retval == -ENOMEM)
959 		return ZFCP_ERP_NOMEM;
960 	erp_action->step = ZFCP_ERP_STEP_LUN_CLOSING;
961 	if (retval)
962 		return ZFCP_ERP_FAILED;
963 	return ZFCP_ERP_CONTINUES;
964 }
965 
966 static int zfcp_erp_lun_strategy_open(struct zfcp_erp_action *erp_action)
967 {
968 	int retval = zfcp_fsf_open_lun(erp_action);
969 	if (retval == -ENOMEM)
970 		return ZFCP_ERP_NOMEM;
971 	erp_action->step = ZFCP_ERP_STEP_LUN_OPENING;
972 	if (retval)
973 		return  ZFCP_ERP_FAILED;
974 	return ZFCP_ERP_CONTINUES;
975 }
976 
977 static int zfcp_erp_lun_strategy(struct zfcp_erp_action *erp_action)
978 {
979 	struct scsi_device *sdev = erp_action->sdev;
980 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
981 
982 	switch (erp_action->step) {
983 	case ZFCP_ERP_STEP_UNINITIALIZED:
984 		zfcp_erp_lun_strategy_clearstati(sdev);
985 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
986 			return zfcp_erp_lun_strategy_close(erp_action);
987 		/* already closed, fall through */
988 	case ZFCP_ERP_STEP_LUN_CLOSING:
989 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
990 			return ZFCP_ERP_FAILED;
991 		if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
992 			return ZFCP_ERP_EXIT;
993 		return zfcp_erp_lun_strategy_open(erp_action);
994 
995 	case ZFCP_ERP_STEP_LUN_OPENING:
996 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
997 			return ZFCP_ERP_SUCCEEDED;
998 	}
999 	return ZFCP_ERP_FAILED;
1000 }
1001 
1002 static int zfcp_erp_strategy_check_lun(struct scsi_device *sdev, int result)
1003 {
1004 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1005 
1006 	switch (result) {
1007 	case ZFCP_ERP_SUCCEEDED :
1008 		atomic_set(&zfcp_sdev->erp_counter, 0);
1009 		zfcp_erp_lun_unblock(sdev);
1010 		break;
1011 	case ZFCP_ERP_FAILED :
1012 		atomic_inc(&zfcp_sdev->erp_counter);
1013 		if (atomic_read(&zfcp_sdev->erp_counter) > ZFCP_MAX_ERPS) {
1014 			dev_err(&zfcp_sdev->port->adapter->ccw_device->dev,
1015 				"ERP failed for LUN 0x%016Lx on "
1016 				"port 0x%016Lx\n",
1017 				(unsigned long long)zfcp_scsi_dev_lun(sdev),
1018 				(unsigned long long)zfcp_sdev->port->wwpn);
1019 			zfcp_erp_set_lun_status(sdev,
1020 						ZFCP_STATUS_COMMON_ERP_FAILED);
1021 		}
1022 		break;
1023 	}
1024 
1025 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1026 		zfcp_erp_lun_block(sdev, 0);
1027 		result = ZFCP_ERP_EXIT;
1028 	}
1029 	return result;
1030 }
1031 
1032 static int zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
1033 {
1034 	switch (result) {
1035 	case ZFCP_ERP_SUCCEEDED :
1036 		atomic_set(&port->erp_counter, 0);
1037 		zfcp_erp_port_unblock(port);
1038 		break;
1039 
1040 	case ZFCP_ERP_FAILED :
1041 		if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC) {
1042 			zfcp_erp_port_block(port, 0);
1043 			result = ZFCP_ERP_EXIT;
1044 		}
1045 		atomic_inc(&port->erp_counter);
1046 		if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS) {
1047 			dev_err(&port->adapter->ccw_device->dev,
1048 				"ERP failed for remote port 0x%016Lx\n",
1049 				(unsigned long long)port->wwpn);
1050 			zfcp_erp_set_port_status(port,
1051 					 ZFCP_STATUS_COMMON_ERP_FAILED);
1052 		}
1053 		break;
1054 	}
1055 
1056 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1057 		zfcp_erp_port_block(port, 0);
1058 		result = ZFCP_ERP_EXIT;
1059 	}
1060 	return result;
1061 }
1062 
1063 static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter,
1064 					   int result)
1065 {
1066 	switch (result) {
1067 	case ZFCP_ERP_SUCCEEDED :
1068 		atomic_set(&adapter->erp_counter, 0);
1069 		zfcp_erp_adapter_unblock(adapter);
1070 		break;
1071 
1072 	case ZFCP_ERP_FAILED :
1073 		atomic_inc(&adapter->erp_counter);
1074 		if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS) {
1075 			dev_err(&adapter->ccw_device->dev,
1076 				"ERP cannot recover an error "
1077 				"on the FCP device\n");
1078 			zfcp_erp_set_adapter_status(adapter,
1079 					    ZFCP_STATUS_COMMON_ERP_FAILED);
1080 		}
1081 		break;
1082 	}
1083 
1084 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1085 		zfcp_erp_adapter_block(adapter, 0);
1086 		result = ZFCP_ERP_EXIT;
1087 	}
1088 	return result;
1089 }
1090 
1091 static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action,
1092 					  int result)
1093 {
1094 	struct zfcp_adapter *adapter = erp_action->adapter;
1095 	struct zfcp_port *port = erp_action->port;
1096 	struct scsi_device *sdev = erp_action->sdev;
1097 
1098 	switch (erp_action->action) {
1099 
1100 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1101 		result = zfcp_erp_strategy_check_lun(sdev, result);
1102 		break;
1103 
1104 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1105 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1106 		result = zfcp_erp_strategy_check_port(port, result);
1107 		break;
1108 
1109 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1110 		result = zfcp_erp_strategy_check_adapter(adapter, result);
1111 		break;
1112 	}
1113 	return result;
1114 }
1115 
1116 static int zfcp_erp_strat_change_det(atomic_t *target_status, u32 erp_status)
1117 {
1118 	int status = atomic_read(target_status);
1119 
1120 	if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
1121 	    (erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1122 		return 1; /* take it online */
1123 
1124 	if (!(status & ZFCP_STATUS_COMMON_RUNNING) &&
1125 	    !(erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1126 		return 1; /* take it offline */
1127 
1128 	return 0;
1129 }
1130 
1131 static int zfcp_erp_strategy_statechange(struct zfcp_erp_action *act, int ret)
1132 {
1133 	int action = act->action;
1134 	struct zfcp_adapter *adapter = act->adapter;
1135 	struct zfcp_port *port = act->port;
1136 	struct scsi_device *sdev = act->sdev;
1137 	struct zfcp_scsi_dev *zfcp_sdev;
1138 	u32 erp_status = act->status;
1139 
1140 	switch (action) {
1141 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1142 		if (zfcp_erp_strat_change_det(&adapter->status, erp_status)) {
1143 			_zfcp_erp_adapter_reopen(adapter,
1144 						 ZFCP_STATUS_COMMON_ERP_FAILED,
1145 						 "ersscg1");
1146 			return ZFCP_ERP_EXIT;
1147 		}
1148 		break;
1149 
1150 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1151 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1152 		if (zfcp_erp_strat_change_det(&port->status, erp_status)) {
1153 			_zfcp_erp_port_reopen(port,
1154 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1155 					      "ersscg2");
1156 			return ZFCP_ERP_EXIT;
1157 		}
1158 		break;
1159 
1160 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1161 		zfcp_sdev = sdev_to_zfcp(sdev);
1162 		if (zfcp_erp_strat_change_det(&zfcp_sdev->status, erp_status)) {
1163 			_zfcp_erp_lun_reopen(sdev,
1164 					     ZFCP_STATUS_COMMON_ERP_FAILED,
1165 					     "ersscg3", 0);
1166 			return ZFCP_ERP_EXIT;
1167 		}
1168 		break;
1169 	}
1170 	return ret;
1171 }
1172 
1173 static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
1174 {
1175 	struct zfcp_adapter *adapter = erp_action->adapter;
1176 	struct zfcp_scsi_dev *zfcp_sdev;
1177 
1178 	adapter->erp_total_count--;
1179 	if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1180 		adapter->erp_low_mem_count--;
1181 		erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1182 	}
1183 
1184 	list_del(&erp_action->list);
1185 	zfcp_dbf_rec_run("eractd1", erp_action);
1186 
1187 	switch (erp_action->action) {
1188 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1189 		zfcp_sdev = sdev_to_zfcp(erp_action->sdev);
1190 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1191 				  &zfcp_sdev->status);
1192 		break;
1193 
1194 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1195 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1196 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1197 				  &erp_action->port->status);
1198 		break;
1199 
1200 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1201 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1202 				  &erp_action->adapter->status);
1203 		break;
1204 	}
1205 }
1206 
1207 /**
1208  * zfcp_erp_try_rport_unblock - unblock rport if no more/new recovery
1209  * @port: zfcp_port whose fc_rport we should try to unblock
1210  */
1211 static void zfcp_erp_try_rport_unblock(struct zfcp_port *port)
1212 {
1213 	unsigned long flags;
1214 	struct zfcp_adapter *adapter = port->adapter;
1215 	int port_status;
1216 	struct Scsi_Host *shost = adapter->scsi_host;
1217 	struct scsi_device *sdev;
1218 
1219 	write_lock_irqsave(&adapter->erp_lock, flags);
1220 	port_status = atomic_read(&port->status);
1221 	if ((port_status & ZFCP_STATUS_COMMON_UNBLOCKED)    == 0 ||
1222 	    (port_status & (ZFCP_STATUS_COMMON_ERP_INUSE |
1223 			    ZFCP_STATUS_COMMON_ERP_FAILED)) != 0) {
1224 		/* new ERP of severity >= port triggered elsewhere meanwhile or
1225 		 * local link down (adapter erp_failed but not clear unblock)
1226 		 */
1227 		zfcp_dbf_rec_run_lvl(4, "ertru_p", &port->erp_action);
1228 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1229 		return;
1230 	}
1231 	spin_lock(shost->host_lock);
1232 	__shost_for_each_device(sdev, shost) {
1233 		struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
1234 		int lun_status;
1235 
1236 		if (zsdev->port != port)
1237 			continue;
1238 		/* LUN under port of interest */
1239 		lun_status = atomic_read(&zsdev->status);
1240 		if ((lun_status & ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
1241 			continue; /* unblock rport despite failed LUNs */
1242 		/* LUN recovery not given up yet [maybe follow-up pending] */
1243 		if ((lun_status & ZFCP_STATUS_COMMON_UNBLOCKED) == 0 ||
1244 		    (lun_status & ZFCP_STATUS_COMMON_ERP_INUSE) != 0) {
1245 			/* LUN blocked:
1246 			 * not yet unblocked [LUN recovery pending]
1247 			 * or meanwhile blocked [new LUN recovery triggered]
1248 			 */
1249 			zfcp_dbf_rec_run_lvl(4, "ertru_l", &zsdev->erp_action);
1250 			spin_unlock(shost->host_lock);
1251 			write_unlock_irqrestore(&adapter->erp_lock, flags);
1252 			return;
1253 		}
1254 	}
1255 	/* now port has no child or all children have completed recovery,
1256 	 * and no ERP of severity >= port was meanwhile triggered elsewhere
1257 	 */
1258 	zfcp_scsi_schedule_rport_register(port);
1259 	spin_unlock(shost->host_lock);
1260 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1261 }
1262 
1263 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
1264 {
1265 	struct zfcp_adapter *adapter = act->adapter;
1266 	struct zfcp_port *port = act->port;
1267 	struct scsi_device *sdev = act->sdev;
1268 
1269 	switch (act->action) {
1270 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1271 		if (!(act->status & ZFCP_STATUS_ERP_NO_REF))
1272 			scsi_device_put(sdev);
1273 		zfcp_erp_try_rport_unblock(port);
1274 		break;
1275 
1276 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1277 		/* This switch case might also happen after a forced reopen
1278 		 * was successfully done and thus overwritten with a new
1279 		 * non-forced reopen at `ersfs_2'. In this case, we must not
1280 		 * do the clean-up of the non-forced version.
1281 		 */
1282 		if (act->step != ZFCP_ERP_STEP_UNINITIALIZED)
1283 			if (result == ZFCP_ERP_SUCCEEDED)
1284 				zfcp_erp_try_rport_unblock(port);
1285 		/* fall through */
1286 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1287 		put_device(&port->dev);
1288 		break;
1289 
1290 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1291 		if (result == ZFCP_ERP_SUCCEEDED) {
1292 			register_service_level(&adapter->service_level);
1293 			zfcp_fc_conditional_port_scan(adapter);
1294 			queue_work(adapter->work_queue, &adapter->ns_up_work);
1295 		} else
1296 			unregister_service_level(&adapter->service_level);
1297 
1298 		kref_put(&adapter->ref, zfcp_adapter_release);
1299 		break;
1300 	}
1301 }
1302 
1303 static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
1304 {
1305 	switch (erp_action->action) {
1306 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1307 		return zfcp_erp_adapter_strategy(erp_action);
1308 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1309 		return zfcp_erp_port_forced_strategy(erp_action);
1310 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1311 		return zfcp_erp_port_strategy(erp_action);
1312 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1313 		return zfcp_erp_lun_strategy(erp_action);
1314 	}
1315 	return ZFCP_ERP_FAILED;
1316 }
1317 
1318 static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
1319 {
1320 	int retval;
1321 	unsigned long flags;
1322 	struct zfcp_adapter *adapter = erp_action->adapter;
1323 
1324 	kref_get(&adapter->ref);
1325 
1326 	write_lock_irqsave(&adapter->erp_lock, flags);
1327 	zfcp_erp_strategy_check_fsfreq(erp_action);
1328 
1329 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
1330 		zfcp_erp_action_dequeue(erp_action);
1331 		retval = ZFCP_ERP_DISMISSED;
1332 		goto unlock;
1333 	}
1334 
1335 	if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
1336 		retval = ZFCP_ERP_FAILED;
1337 		goto check_target;
1338 	}
1339 
1340 	zfcp_erp_action_to_running(erp_action);
1341 
1342 	/* no lock to allow for blocking operations */
1343 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1344 	retval = zfcp_erp_strategy_do_action(erp_action);
1345 	write_lock_irqsave(&adapter->erp_lock, flags);
1346 
1347 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
1348 		retval = ZFCP_ERP_CONTINUES;
1349 
1350 	switch (retval) {
1351 	case ZFCP_ERP_NOMEM:
1352 		if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
1353 			++adapter->erp_low_mem_count;
1354 			erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
1355 		}
1356 		if (adapter->erp_total_count == adapter->erp_low_mem_count)
1357 			_zfcp_erp_adapter_reopen(adapter, 0, "erstgy1");
1358 		else {
1359 			zfcp_erp_strategy_memwait(erp_action);
1360 			retval = ZFCP_ERP_CONTINUES;
1361 		}
1362 		goto unlock;
1363 
1364 	case ZFCP_ERP_CONTINUES:
1365 		if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1366 			--adapter->erp_low_mem_count;
1367 			erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1368 		}
1369 		goto unlock;
1370 	}
1371 
1372 check_target:
1373 	retval = zfcp_erp_strategy_check_target(erp_action, retval);
1374 	zfcp_erp_action_dequeue(erp_action);
1375 	retval = zfcp_erp_strategy_statechange(erp_action, retval);
1376 	if (retval == ZFCP_ERP_EXIT)
1377 		goto unlock;
1378 	if (retval == ZFCP_ERP_SUCCEEDED)
1379 		zfcp_erp_strategy_followup_success(erp_action);
1380 	if (retval == ZFCP_ERP_FAILED)
1381 		zfcp_erp_strategy_followup_failed(erp_action);
1382 
1383  unlock:
1384 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1385 
1386 	if (retval != ZFCP_ERP_CONTINUES)
1387 		zfcp_erp_action_cleanup(erp_action, retval);
1388 
1389 	kref_put(&adapter->ref, zfcp_adapter_release);
1390 	return retval;
1391 }
1392 
1393 static int zfcp_erp_thread(void *data)
1394 {
1395 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
1396 	struct list_head *next;
1397 	struct zfcp_erp_action *act;
1398 	unsigned long flags;
1399 
1400 	for (;;) {
1401 		wait_event_interruptible(adapter->erp_ready_wq,
1402 			   !list_empty(&adapter->erp_ready_head) ||
1403 			   kthread_should_stop());
1404 
1405 		if (kthread_should_stop())
1406 			break;
1407 
1408 		write_lock_irqsave(&adapter->erp_lock, flags);
1409 		next = adapter->erp_ready_head.next;
1410 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1411 
1412 		if (next != &adapter->erp_ready_head) {
1413 			act = list_entry(next, struct zfcp_erp_action, list);
1414 
1415 			/* there is more to come after dismission, no notify */
1416 			if (zfcp_erp_strategy(act) != ZFCP_ERP_DISMISSED)
1417 				zfcp_erp_wakeup(adapter);
1418 		}
1419 	}
1420 
1421 	return 0;
1422 }
1423 
1424 /**
1425  * zfcp_erp_thread_setup - Start ERP thread for adapter
1426  * @adapter: Adapter to start the ERP thread for
1427  *
1428  * Returns 0 on success or error code from kernel_thread()
1429  */
1430 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
1431 {
1432 	struct task_struct *thread;
1433 
1434 	thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
1435 			     dev_name(&adapter->ccw_device->dev));
1436 	if (IS_ERR(thread)) {
1437 		dev_err(&adapter->ccw_device->dev,
1438 			"Creating an ERP thread for the FCP device failed.\n");
1439 		return PTR_ERR(thread);
1440 	}
1441 
1442 	adapter->erp_thread = thread;
1443 	return 0;
1444 }
1445 
1446 /**
1447  * zfcp_erp_thread_kill - Stop ERP thread.
1448  * @adapter: Adapter where the ERP thread should be stopped.
1449  *
1450  * The caller of this routine ensures that the specified adapter has
1451  * been shut down and that this operation has been completed. Thus,
1452  * there are no pending erp_actions which would need to be handled
1453  * here.
1454  */
1455 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
1456 {
1457 	kthread_stop(adapter->erp_thread);
1458 	adapter->erp_thread = NULL;
1459 	WARN_ON(!list_empty(&adapter->erp_ready_head));
1460 	WARN_ON(!list_empty(&adapter->erp_running_head));
1461 }
1462 
1463 /**
1464  * zfcp_erp_wait - wait for completion of error recovery on an adapter
1465  * @adapter: adapter for which to wait for completion of its error recovery
1466  */
1467 void zfcp_erp_wait(struct zfcp_adapter *adapter)
1468 {
1469 	wait_event(adapter->erp_done_wqh,
1470 		   !(atomic_read(&adapter->status) &
1471 			ZFCP_STATUS_ADAPTER_ERP_PENDING));
1472 }
1473 
1474 /**
1475  * zfcp_erp_set_adapter_status - set adapter status bits
1476  * @adapter: adapter to change the status
1477  * @mask: status bits to change
1478  *
1479  * Changes in common status bits are propagated to attached ports and LUNs.
1480  */
1481 void zfcp_erp_set_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1482 {
1483 	struct zfcp_port *port;
1484 	struct scsi_device *sdev;
1485 	unsigned long flags;
1486 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1487 
1488 	atomic_or(mask, &adapter->status);
1489 
1490 	if (!common_mask)
1491 		return;
1492 
1493 	read_lock_irqsave(&adapter->port_list_lock, flags);
1494 	list_for_each_entry(port, &adapter->port_list, list)
1495 		atomic_or(common_mask, &port->status);
1496 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1497 
1498 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1499 	__shost_for_each_device(sdev, adapter->scsi_host)
1500 		atomic_or(common_mask, &sdev_to_zfcp(sdev)->status);
1501 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1502 }
1503 
1504 /**
1505  * zfcp_erp_clear_adapter_status - clear adapter status bits
1506  * @adapter: adapter to change the status
1507  * @mask: status bits to change
1508  *
1509  * Changes in common status bits are propagated to attached ports and LUNs.
1510  */
1511 void zfcp_erp_clear_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1512 {
1513 	struct zfcp_port *port;
1514 	struct scsi_device *sdev;
1515 	unsigned long flags;
1516 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1517 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1518 
1519 	atomic_andnot(mask, &adapter->status);
1520 
1521 	if (!common_mask)
1522 		return;
1523 
1524 	if (clear_counter)
1525 		atomic_set(&adapter->erp_counter, 0);
1526 
1527 	read_lock_irqsave(&adapter->port_list_lock, flags);
1528 	list_for_each_entry(port, &adapter->port_list, list) {
1529 		atomic_andnot(common_mask, &port->status);
1530 		if (clear_counter)
1531 			atomic_set(&port->erp_counter, 0);
1532 	}
1533 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1534 
1535 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1536 	__shost_for_each_device(sdev, adapter->scsi_host) {
1537 		atomic_andnot(common_mask, &sdev_to_zfcp(sdev)->status);
1538 		if (clear_counter)
1539 			atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1540 	}
1541 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1542 }
1543 
1544 /**
1545  * zfcp_erp_set_port_status - set port status bits
1546  * @port: port to change the status
1547  * @mask: status bits to change
1548  *
1549  * Changes in common status bits are propagated to attached LUNs.
1550  */
1551 void zfcp_erp_set_port_status(struct zfcp_port *port, u32 mask)
1552 {
1553 	struct scsi_device *sdev;
1554 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1555 	unsigned long flags;
1556 
1557 	atomic_or(mask, &port->status);
1558 
1559 	if (!common_mask)
1560 		return;
1561 
1562 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1563 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1564 		if (sdev_to_zfcp(sdev)->port == port)
1565 			atomic_or(common_mask,
1566 					&sdev_to_zfcp(sdev)->status);
1567 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1568 }
1569 
1570 /**
1571  * zfcp_erp_clear_port_status - clear port status bits
1572  * @port: adapter to change the status
1573  * @mask: status bits to change
1574  *
1575  * Changes in common status bits are propagated to attached LUNs.
1576  */
1577 void zfcp_erp_clear_port_status(struct zfcp_port *port, u32 mask)
1578 {
1579 	struct scsi_device *sdev;
1580 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1581 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1582 	unsigned long flags;
1583 
1584 	atomic_andnot(mask, &port->status);
1585 
1586 	if (!common_mask)
1587 		return;
1588 
1589 	if (clear_counter)
1590 		atomic_set(&port->erp_counter, 0);
1591 
1592 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1593 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1594 		if (sdev_to_zfcp(sdev)->port == port) {
1595 			atomic_andnot(common_mask,
1596 					  &sdev_to_zfcp(sdev)->status);
1597 			if (clear_counter)
1598 				atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1599 		}
1600 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1601 }
1602 
1603 /**
1604  * zfcp_erp_set_lun_status - set lun status bits
1605  * @sdev: SCSI device / lun to set the status bits
1606  * @mask: status bits to change
1607  */
1608 void zfcp_erp_set_lun_status(struct scsi_device *sdev, u32 mask)
1609 {
1610 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1611 
1612 	atomic_or(mask, &zfcp_sdev->status);
1613 }
1614 
1615 /**
1616  * zfcp_erp_clear_lun_status - clear lun status bits
1617  * @sdev: SCSi device / lun to clear the status bits
1618  * @mask: status bits to change
1619  */
1620 void zfcp_erp_clear_lun_status(struct scsi_device *sdev, u32 mask)
1621 {
1622 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1623 
1624 	atomic_andnot(mask, &zfcp_sdev->status);
1625 
1626 	if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1627 		atomic_set(&zfcp_sdev->erp_counter, 0);
1628 }
1629 
1630