xref: /openbmc/linux/drivers/s390/scsi/zfcp_ccw.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * zfcp device driver
4  *
5  * Registration and callback for the s390 common I/O layer.
6  *
7  * Copyright IBM Corp. 2002, 2010
8  */
9 
10 #define KMSG_COMPONENT "zfcp"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/module.h>
14 #include "zfcp_ext.h"
15 #include "zfcp_reqlist.h"
16 
17 #define ZFCP_MODEL_PRIV 0x4
18 
19 static DEFINE_SPINLOCK(zfcp_ccw_adapter_ref_lock);
20 
21 struct zfcp_adapter *zfcp_ccw_adapter_by_cdev(struct ccw_device *cdev)
22 {
23 	struct zfcp_adapter *adapter;
24 	unsigned long flags;
25 
26 	spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
27 	adapter = dev_get_drvdata(&cdev->dev);
28 	if (adapter)
29 		kref_get(&adapter->ref);
30 	spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
31 	return adapter;
32 }
33 
34 void zfcp_ccw_adapter_put(struct zfcp_adapter *adapter)
35 {
36 	unsigned long flags;
37 
38 	spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
39 	kref_put(&adapter->ref, zfcp_adapter_release);
40 	spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
41 }
42 
43 /**
44  * zfcp_ccw_activate - activate adapter and wait for it to finish
45  * @cdev: pointer to belonging ccw device
46  * @clear: Status flags to clear.
47  * @tag: s390dbf trace record tag
48  */
49 static int zfcp_ccw_activate(struct ccw_device *cdev, int clear, char *tag)
50 {
51 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
52 
53 	if (!adapter)
54 		return 0;
55 
56 	zfcp_erp_clear_adapter_status(adapter, clear);
57 	zfcp_erp_set_adapter_status(adapter, ZFCP_STATUS_COMMON_RUNNING);
58 	zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
59 				tag);
60 
61 	/*
62 	 * We want to scan ports here, with some random backoff and without
63 	 * rate limit. Recovery has already scheduled a port scan for us,
64 	 * but with both random delay and rate limit. Nevertheless we get
65 	 * what we want here by flushing the scheduled work after sleeping
66 	 * an equivalent random time.
67 	 * Let the port scan random delay elapse first. If recovery finishes
68 	 * up to that point in time, that would be perfect for both recovery
69 	 * and port scan. If not, i.e. recovery takes ages, there was no
70 	 * point in waiting a random delay on top of the time consumed by
71 	 * recovery.
72 	 */
73 	msleep(zfcp_fc_port_scan_backoff());
74 	zfcp_erp_wait(adapter);
75 	flush_delayed_work(&adapter->scan_work);
76 
77 	zfcp_ccw_adapter_put(adapter);
78 
79 	return 0;
80 }
81 
82 static struct ccw_device_id zfcp_ccw_device_id[] = {
83 	{ CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, 0x3) },
84 	{ CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, ZFCP_MODEL_PRIV) },
85 	{},
86 };
87 MODULE_DEVICE_TABLE(ccw, zfcp_ccw_device_id);
88 
89 /**
90  * zfcp_ccw_probe - probe function of zfcp driver
91  * @cdev: pointer to belonging ccw device
92  *
93  * This function gets called by the common i/o layer for each FCP
94  * device found on the current system. This is only a stub to make cio
95  * work: To only allocate adapter resources for devices actually used,
96  * the allocation is deferred to the first call to ccw_set_online.
97  */
98 static int zfcp_ccw_probe(struct ccw_device *cdev)
99 {
100 	return 0;
101 }
102 
103 /**
104  * zfcp_ccw_remove - remove function of zfcp driver
105  * @cdev: pointer to belonging ccw device
106  *
107  * This function gets called by the common i/o layer and removes an adapter
108  * from the system. Task of this function is to get rid of all units and
109  * ports that belong to this adapter. And in addition all resources of this
110  * adapter will be freed too.
111  */
112 static void zfcp_ccw_remove(struct ccw_device *cdev)
113 {
114 	struct zfcp_adapter *adapter;
115 	struct zfcp_port *port, *p;
116 	struct zfcp_unit *unit, *u;
117 	LIST_HEAD(unit_remove_lh);
118 	LIST_HEAD(port_remove_lh);
119 
120 	ccw_device_set_offline(cdev);
121 
122 	adapter = zfcp_ccw_adapter_by_cdev(cdev);
123 	if (!adapter)
124 		return;
125 
126 	write_lock_irq(&adapter->port_list_lock);
127 	list_for_each_entry_safe(port, p, &adapter->port_list, list) {
128 		write_lock(&port->unit_list_lock);
129 		list_for_each_entry_safe(unit, u, &port->unit_list, list)
130 			list_move(&unit->list, &unit_remove_lh);
131 		write_unlock(&port->unit_list_lock);
132 		list_move(&port->list, &port_remove_lh);
133 	}
134 	write_unlock_irq(&adapter->port_list_lock);
135 	zfcp_ccw_adapter_put(adapter); /* put from zfcp_ccw_adapter_by_cdev */
136 
137 	list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
138 		device_unregister(&unit->dev);
139 
140 	list_for_each_entry_safe(port, p, &port_remove_lh, list)
141 		device_unregister(&port->dev);
142 
143 	zfcp_adapter_unregister(adapter);
144 }
145 
146 /**
147  * zfcp_ccw_set_online - set_online function of zfcp driver
148  * @cdev: pointer to belonging ccw device
149  *
150  * This function gets called by the common i/o layer and sets an
151  * adapter into state online.  The first call will allocate all
152  * adapter resources that will be retained until the device is removed
153  * via zfcp_ccw_remove.
154  *
155  * Setting an fcp device online means that it will be registered with
156  * the SCSI stack, that the QDIO queues will be set up and that the
157  * adapter will be opened.
158  */
159 static int zfcp_ccw_set_online(struct ccw_device *cdev)
160 {
161 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
162 
163 	if (!adapter) {
164 		adapter = zfcp_adapter_enqueue(cdev);
165 
166 		if (IS_ERR(adapter)) {
167 			dev_err(&cdev->dev,
168 				"Setting up data structures for the "
169 				"FCP adapter failed\n");
170 			return PTR_ERR(adapter);
171 		}
172 		kref_get(&adapter->ref);
173 	}
174 
175 	/* initialize request counter */
176 	BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
177 	adapter->req_no = 0;
178 
179 	zfcp_ccw_activate(cdev, 0, "ccsonl1");
180 
181 	/*
182 	 * We want to scan ports here, always, with some random delay and
183 	 * without rate limit - basically what zfcp_ccw_activate() has
184 	 * achieved for us. Not quite! That port scan depended on
185 	 * !no_auto_port_rescan. So let's cover the no_auto_port_rescan
186 	 * case here to make sure a port scan is done unconditionally.
187 	 * Since zfcp_ccw_activate() has waited the desired random time,
188 	 * we can immediately schedule and flush a port scan for the
189 	 * remaining cases.
190 	 */
191 	zfcp_fc_inverse_conditional_port_scan(adapter);
192 	flush_delayed_work(&adapter->scan_work);
193 	zfcp_ccw_adapter_put(adapter);
194 	return 0;
195 }
196 
197 /**
198  * zfcp_ccw_offline_sync - shut down adapter and wait for it to finish
199  * @cdev: pointer to belonging ccw device
200  * @set: Status flags to set.
201  * @tag: s390dbf trace record tag
202  *
203  * This function gets called by the common i/o layer and sets an adapter
204  * into state offline.
205  */
206 static int zfcp_ccw_offline_sync(struct ccw_device *cdev, int set, char *tag)
207 {
208 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
209 
210 	if (!adapter)
211 		return 0;
212 
213 	zfcp_erp_set_adapter_status(adapter, set);
214 	zfcp_erp_adapter_shutdown(adapter, 0, tag);
215 	zfcp_erp_wait(adapter);
216 
217 	zfcp_ccw_adapter_put(adapter);
218 	return 0;
219 }
220 
221 /**
222  * zfcp_ccw_set_offline - set_offline function of zfcp driver
223  * @cdev: pointer to belonging ccw device
224  *
225  * This function gets called by the common i/o layer and sets an adapter
226  * into state offline.
227  */
228 static int zfcp_ccw_set_offline(struct ccw_device *cdev)
229 {
230 	return zfcp_ccw_offline_sync(cdev, 0, "ccsoff1");
231 }
232 
233 /**
234  * zfcp_ccw_notify - ccw notify function
235  * @cdev: pointer to belonging ccw device
236  * @event: indicates if adapter was detached or attached
237  *
238  * This function gets called by the common i/o layer if an adapter has gone
239  * or reappeared.
240  */
241 static int zfcp_ccw_notify(struct ccw_device *cdev, int event)
242 {
243 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
244 
245 	if (!adapter)
246 		return 1;
247 
248 	switch (event) {
249 	case CIO_GONE:
250 		if (atomic_read(&adapter->status) &
251 		    ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
252 			zfcp_dbf_hba_basic("ccnigo1", adapter);
253 			break;
254 		}
255 		dev_warn(&cdev->dev, "The FCP device has been detached\n");
256 		zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti1");
257 		break;
258 	case CIO_NO_PATH:
259 		dev_warn(&cdev->dev,
260 			 "The CHPID for the FCP device is offline\n");
261 		zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti2");
262 		break;
263 	case CIO_OPER:
264 		if (atomic_read(&adapter->status) &
265 		    ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
266 			zfcp_dbf_hba_basic("ccniop1", adapter);
267 			break;
268 		}
269 		dev_info(&cdev->dev, "The FCP device is operational again\n");
270 		zfcp_erp_set_adapter_status(adapter,
271 					    ZFCP_STATUS_COMMON_RUNNING);
272 		zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
273 					"ccnoti4");
274 		break;
275 	case CIO_BOXED:
276 		dev_warn(&cdev->dev, "The FCP device did not respond within "
277 				     "the specified time\n");
278 		zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti5");
279 		break;
280 	}
281 
282 	zfcp_ccw_adapter_put(adapter);
283 	return 1;
284 }
285 
286 /**
287  * zfcp_ccw_shutdown - handle shutdown from cio
288  * @cdev: device for adapter to shutdown.
289  */
290 static void zfcp_ccw_shutdown(struct ccw_device *cdev)
291 {
292 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
293 
294 	if (!adapter)
295 		return;
296 
297 	zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1");
298 	zfcp_erp_wait(adapter);
299 	zfcp_erp_thread_kill(adapter);
300 
301 	zfcp_ccw_adapter_put(adapter);
302 }
303 
304 static int zfcp_ccw_suspend(struct ccw_device *cdev)
305 {
306 	zfcp_ccw_offline_sync(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccsusp1");
307 	return 0;
308 }
309 
310 static int zfcp_ccw_thaw(struct ccw_device *cdev)
311 {
312 	/* trace records for thaw and final shutdown during suspend
313 	   can only be found in system dump until the end of suspend
314 	   but not after resume because it's based on the memory image
315 	   right after the very first suspend (freeze) callback */
316 	zfcp_ccw_activate(cdev, 0, "ccthaw1");
317 	return 0;
318 }
319 
320 static int zfcp_ccw_resume(struct ccw_device *cdev)
321 {
322 	zfcp_ccw_activate(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccresu1");
323 	return 0;
324 }
325 
326 struct ccw_driver zfcp_ccw_driver = {
327 	.driver = {
328 		.owner	= THIS_MODULE,
329 		.name	= "zfcp",
330 	},
331 	.ids         = zfcp_ccw_device_id,
332 	.probe       = zfcp_ccw_probe,
333 	.remove      = zfcp_ccw_remove,
334 	.set_online  = zfcp_ccw_set_online,
335 	.set_offline = zfcp_ccw_set_offline,
336 	.notify      = zfcp_ccw_notify,
337 	.shutdown    = zfcp_ccw_shutdown,
338 	.freeze      = zfcp_ccw_suspend,
339 	.thaw	     = zfcp_ccw_thaw,
340 	.restore     = zfcp_ccw_resume,
341 };
342