xref: /openbmc/linux/drivers/s390/scsi/zfcp_ccw.c (revision 43ffe817)
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(port, &adapter->port_list, list) {
128 		write_lock(&port->unit_list_lock);
129 		list_splice_init(&port->unit_list, &unit_remove_lh);
130 		write_unlock(&port->unit_list_lock);
131 	}
132 	list_splice_init(&adapter->port_list, &port_remove_lh);
133 	write_unlock_irq(&adapter->port_list_lock);
134 	zfcp_ccw_adapter_put(adapter); /* put from zfcp_ccw_adapter_by_cdev */
135 
136 	list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
137 		device_unregister(&unit->dev);
138 
139 	list_for_each_entry_safe(port, p, &port_remove_lh, list)
140 		device_unregister(&port->dev);
141 
142 	zfcp_adapter_unregister(adapter);
143 }
144 
145 /**
146  * zfcp_ccw_set_online - set_online function of zfcp driver
147  * @cdev: pointer to belonging ccw device
148  *
149  * This function gets called by the common i/o layer and sets an
150  * adapter into state online.  The first call will allocate all
151  * adapter resources that will be retained until the device is removed
152  * via zfcp_ccw_remove.
153  *
154  * Setting an fcp device online means that it will be registered with
155  * the SCSI stack, that the QDIO queues will be set up and that the
156  * adapter will be opened.
157  */
158 static int zfcp_ccw_set_online(struct ccw_device *cdev)
159 {
160 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
161 
162 	if (!adapter) {
163 		adapter = zfcp_adapter_enqueue(cdev);
164 
165 		if (IS_ERR(adapter)) {
166 			dev_err(&cdev->dev,
167 				"Setting up data structures for the "
168 				"FCP adapter failed\n");
169 			return PTR_ERR(adapter);
170 		}
171 		kref_get(&adapter->ref);
172 	}
173 
174 	/* initialize request counter */
175 	BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
176 	adapter->req_no = 0;
177 
178 	zfcp_ccw_activate(cdev, 0, "ccsonl1");
179 
180 	/*
181 	 * We want to scan ports here, always, with some random delay and
182 	 * without rate limit - basically what zfcp_ccw_activate() has
183 	 * achieved for us. Not quite! That port scan depended on
184 	 * !no_auto_port_rescan. So let's cover the no_auto_port_rescan
185 	 * case here to make sure a port scan is done unconditionally.
186 	 * Since zfcp_ccw_activate() has waited the desired random time,
187 	 * we can immediately schedule and flush a port scan for the
188 	 * remaining cases.
189 	 */
190 	zfcp_fc_inverse_conditional_port_scan(adapter);
191 	flush_delayed_work(&adapter->scan_work);
192 	zfcp_ccw_adapter_put(adapter);
193 	return 0;
194 }
195 
196 /**
197  * zfcp_ccw_offline_sync - shut down adapter and wait for it to finish
198  * @cdev: pointer to belonging ccw device
199  * @set: Status flags to set.
200  * @tag: s390dbf trace record tag
201  *
202  * This function gets called by the common i/o layer and sets an adapter
203  * into state offline.
204  */
205 static int zfcp_ccw_offline_sync(struct ccw_device *cdev, int set, char *tag)
206 {
207 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
208 
209 	if (!adapter)
210 		return 0;
211 
212 	zfcp_erp_set_adapter_status(adapter, set);
213 	zfcp_erp_adapter_shutdown(adapter, 0, tag);
214 	zfcp_erp_wait(adapter);
215 
216 	zfcp_ccw_adapter_put(adapter);
217 	return 0;
218 }
219 
220 /**
221  * zfcp_ccw_set_offline - set_offline function of zfcp driver
222  * @cdev: pointer to belonging ccw device
223  *
224  * This function gets called by the common i/o layer and sets an adapter
225  * into state offline.
226  */
227 static int zfcp_ccw_set_offline(struct ccw_device *cdev)
228 {
229 	return zfcp_ccw_offline_sync(cdev, 0, "ccsoff1");
230 }
231 
232 /**
233  * zfcp_ccw_notify - ccw notify function
234  * @cdev: pointer to belonging ccw device
235  * @event: indicates if adapter was detached or attached
236  *
237  * This function gets called by the common i/o layer if an adapter has gone
238  * or reappeared.
239  */
240 static int zfcp_ccw_notify(struct ccw_device *cdev, int event)
241 {
242 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
243 
244 	if (!adapter)
245 		return 1;
246 
247 	switch (event) {
248 	case CIO_GONE:
249 		if (atomic_read(&adapter->status) &
250 		    ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
251 			zfcp_dbf_hba_basic("ccnigo1", adapter);
252 			break;
253 		}
254 		dev_warn(&cdev->dev, "The FCP device has been detached\n");
255 		zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti1");
256 		break;
257 	case CIO_NO_PATH:
258 		dev_warn(&cdev->dev,
259 			 "The CHPID for the FCP device is offline\n");
260 		zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti2");
261 		break;
262 	case CIO_OPER:
263 		if (atomic_read(&adapter->status) &
264 		    ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
265 			zfcp_dbf_hba_basic("ccniop1", adapter);
266 			break;
267 		}
268 		dev_info(&cdev->dev, "The FCP device is operational again\n");
269 		zfcp_erp_set_adapter_status(adapter,
270 					    ZFCP_STATUS_COMMON_RUNNING);
271 		zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
272 					"ccnoti4");
273 		break;
274 	case CIO_BOXED:
275 		dev_warn(&cdev->dev, "The FCP device did not respond within "
276 				     "the specified time\n");
277 		zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti5");
278 		break;
279 	}
280 
281 	zfcp_ccw_adapter_put(adapter);
282 	return 1;
283 }
284 
285 /**
286  * zfcp_ccw_shutdown - handle shutdown from cio
287  * @cdev: device for adapter to shutdown.
288  */
289 static void zfcp_ccw_shutdown(struct ccw_device *cdev)
290 {
291 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
292 
293 	if (!adapter)
294 		return;
295 
296 	zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1");
297 	zfcp_erp_wait(adapter);
298 	zfcp_erp_thread_kill(adapter);
299 
300 	zfcp_ccw_adapter_put(adapter);
301 }
302 
303 static int zfcp_ccw_suspend(struct ccw_device *cdev)
304 {
305 	zfcp_ccw_offline_sync(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccsusp1");
306 	return 0;
307 }
308 
309 static int zfcp_ccw_thaw(struct ccw_device *cdev)
310 {
311 	/* trace records for thaw and final shutdown during suspend
312 	   can only be found in system dump until the end of suspend
313 	   but not after resume because it's based on the memory image
314 	   right after the very first suspend (freeze) callback */
315 	zfcp_ccw_activate(cdev, 0, "ccthaw1");
316 	return 0;
317 }
318 
319 static int zfcp_ccw_resume(struct ccw_device *cdev)
320 {
321 	zfcp_ccw_activate(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccresu1");
322 	return 0;
323 }
324 
325 struct ccw_driver zfcp_ccw_driver = {
326 	.driver = {
327 		.owner	= THIS_MODULE,
328 		.name	= "zfcp",
329 	},
330 	.ids         = zfcp_ccw_device_id,
331 	.probe       = zfcp_ccw_probe,
332 	.remove      = zfcp_ccw_remove,
333 	.set_online  = zfcp_ccw_set_online,
334 	.set_offline = zfcp_ccw_set_offline,
335 	.notify      = zfcp_ccw_notify,
336 	.shutdown    = zfcp_ccw_shutdown,
337 	.freeze      = zfcp_ccw_suspend,
338 	.thaw	     = zfcp_ccw_thaw,
339 	.restore     = zfcp_ccw_resume,
340 };
341