xref: /openbmc/linux/drivers/s390/cio/device.c (revision 2df56f4e)
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3  *  bus driver for ccw devices
4  *
5  *    Copyright IBM Corp. 2002, 2008
6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
7  *		 Cornelia Huck (cornelia.huck@de.ibm.com)
8  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
9  */
10 
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/spinlock.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include <linux/list.h>
21 #include <linux/device.h>
22 #include <linux/workqueue.h>
23 #include <linux/delay.h>
24 #include <linux/timer.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/sched/signal.h>
27 #include <linux/dma-mapping.h>
28 
29 #include <asm/ccwdev.h>
30 #include <asm/cio.h>
31 #include <asm/param.h>		/* HZ */
32 #include <asm/cmb.h>
33 #include <asm/isc.h>
34 
35 #include "chp.h"
36 #include "cio.h"
37 #include "cio_debug.h"
38 #include "css.h"
39 #include "device.h"
40 #include "ioasm.h"
41 #include "io_sch.h"
42 #include "blacklist.h"
43 #include "chsc.h"
44 
45 static struct timer_list recovery_timer;
46 static DEFINE_SPINLOCK(recovery_lock);
47 static int recovery_phase;
48 static const unsigned long recovery_delay[] = { 3, 30, 300 };
49 
50 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
51 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
52 static struct bus_type ccw_bus_type;
53 
54 /******************* bus type handling ***********************/
55 
56 /* The Linux driver model distinguishes between a bus type and
57  * the bus itself. Of course we only have one channel
58  * subsystem driver and one channel system per machine, but
59  * we still use the abstraction. T.R. says it's a good idea. */
60 static int
ccw_bus_match(struct device * dev,struct device_driver * drv)61 ccw_bus_match (struct device * dev, struct device_driver * drv)
62 {
63 	struct ccw_device *cdev = to_ccwdev(dev);
64 	struct ccw_driver *cdrv = to_ccwdrv(drv);
65 	const struct ccw_device_id *ids = cdrv->ids, *found;
66 
67 	if (!ids)
68 		return 0;
69 
70 	found = ccw_device_id_match(ids, &cdev->id);
71 	if (!found)
72 		return 0;
73 
74 	cdev->id.driver_info = found->driver_info;
75 
76 	return 1;
77 }
78 
79 /* Store modalias string delimited by prefix/suffix string into buffer with
80  * specified size. Return length of resulting string (excluding trailing '\0')
81  * even if string doesn't fit buffer (snprintf semantics). */
snprint_alias(char * buf,size_t size,const struct ccw_device_id * id,const char * suffix)82 static int snprint_alias(char *buf, size_t size,
83 			 const struct ccw_device_id *id, const char *suffix)
84 {
85 	int len;
86 
87 	len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
88 	if (len > size)
89 		return len;
90 	buf += len;
91 	size -= len;
92 
93 	if (id->dev_type != 0)
94 		len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
95 				id->dev_model, suffix);
96 	else
97 		len += snprintf(buf, size, "dtdm%s", suffix);
98 
99 	return len;
100 }
101 
102 /* Set up environment variables for ccw device uevent. Return 0 on success,
103  * non-zero otherwise. */
ccw_uevent(const struct device * dev,struct kobj_uevent_env * env)104 static int ccw_uevent(const struct device *dev, struct kobj_uevent_env *env)
105 {
106 	const struct ccw_device *cdev = to_ccwdev(dev);
107 	const struct ccw_device_id *id = &(cdev->id);
108 	int ret;
109 	char modalias_buf[30];
110 
111 	/* CU_TYPE= */
112 	ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
113 	if (ret)
114 		return ret;
115 
116 	/* CU_MODEL= */
117 	ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
118 	if (ret)
119 		return ret;
120 
121 	/* The next two can be zero, that's ok for us */
122 	/* DEV_TYPE= */
123 	ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
124 	if (ret)
125 		return ret;
126 
127 	/* DEV_MODEL= */
128 	ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
129 	if (ret)
130 		return ret;
131 
132 	/* MODALIAS=  */
133 	snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
134 	ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
135 	return ret;
136 }
137 
138 static void io_subchannel_irq(struct subchannel *);
139 static int io_subchannel_probe(struct subchannel *);
140 static void io_subchannel_remove(struct subchannel *);
141 static void io_subchannel_shutdown(struct subchannel *);
142 static int io_subchannel_sch_event(struct subchannel *, int);
143 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
144 				   int);
145 static void recovery_func(struct timer_list *unused);
146 
147 static struct css_device_id io_subchannel_ids[] = {
148 	{ .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
149 	{ /* end of list */ },
150 };
151 
io_subchannel_settle(void)152 static int io_subchannel_settle(void)
153 {
154 	int ret;
155 
156 	ret = wait_event_interruptible(ccw_device_init_wq,
157 				atomic_read(&ccw_device_init_count) == 0);
158 	if (ret)
159 		return -EINTR;
160 	flush_workqueue(cio_work_q);
161 	return 0;
162 }
163 
164 static struct css_driver io_subchannel_driver = {
165 	.drv = {
166 		.owner = THIS_MODULE,
167 		.name = "io_subchannel",
168 	},
169 	.subchannel_type = io_subchannel_ids,
170 	.irq = io_subchannel_irq,
171 	.sch_event = io_subchannel_sch_event,
172 	.chp_event = io_subchannel_chp_event,
173 	.probe = io_subchannel_probe,
174 	.remove = io_subchannel_remove,
175 	.shutdown = io_subchannel_shutdown,
176 	.settle = io_subchannel_settle,
177 };
178 
io_subchannel_init(void)179 int __init io_subchannel_init(void)
180 {
181 	int ret;
182 
183 	timer_setup(&recovery_timer, recovery_func, 0);
184 	ret = bus_register(&ccw_bus_type);
185 	if (ret)
186 		return ret;
187 	ret = css_driver_register(&io_subchannel_driver);
188 	if (ret)
189 		bus_unregister(&ccw_bus_type);
190 
191 	return ret;
192 }
193 
194 
195 /************************ device handling **************************/
196 
197 static ssize_t
devtype_show(struct device * dev,struct device_attribute * attr,char * buf)198 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
199 {
200 	struct ccw_device *cdev = to_ccwdev(dev);
201 	struct ccw_device_id *id = &(cdev->id);
202 
203 	if (id->dev_type != 0)
204 		return sprintf(buf, "%04x/%02x\n",
205 				id->dev_type, id->dev_model);
206 	else
207 		return sprintf(buf, "n/a\n");
208 }
209 
210 static ssize_t
cutype_show(struct device * dev,struct device_attribute * attr,char * buf)211 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
212 {
213 	struct ccw_device *cdev = to_ccwdev(dev);
214 	struct ccw_device_id *id = &(cdev->id);
215 
216 	return sprintf(buf, "%04x/%02x\n",
217 		       id->cu_type, id->cu_model);
218 }
219 
220 static ssize_t
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)221 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
222 {
223 	struct ccw_device *cdev = to_ccwdev(dev);
224 	struct ccw_device_id *id = &(cdev->id);
225 	int len;
226 
227 	len = snprint_alias(buf, PAGE_SIZE, id, "\n");
228 
229 	return len > PAGE_SIZE ? PAGE_SIZE : len;
230 }
231 
232 static ssize_t
online_show(struct device * dev,struct device_attribute * attr,char * buf)233 online_show (struct device *dev, struct device_attribute *attr, char *buf)
234 {
235 	struct ccw_device *cdev = to_ccwdev(dev);
236 
237 	return sprintf(buf, cdev->online ? "1\n" : "0\n");
238 }
239 
ccw_device_is_orphan(struct ccw_device * cdev)240 int ccw_device_is_orphan(struct ccw_device *cdev)
241 {
242 	return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
243 }
244 
ccw_device_unregister(struct ccw_device * cdev)245 static void ccw_device_unregister(struct ccw_device *cdev)
246 {
247 	mutex_lock(&cdev->reg_mutex);
248 	if (device_is_registered(&cdev->dev)) {
249 		/* Undo device_add(). */
250 		device_del(&cdev->dev);
251 	}
252 	mutex_unlock(&cdev->reg_mutex);
253 
254 	if (cdev->private->flags.initialized) {
255 		cdev->private->flags.initialized = 0;
256 		/* Release reference from device_initialize(). */
257 		put_device(&cdev->dev);
258 	}
259 }
260 
261 static void io_subchannel_quiesce(struct subchannel *);
262 
263 /**
264  * ccw_device_set_offline() - disable a ccw device for I/O
265  * @cdev: target ccw device
266  *
267  * This function calls the driver's set_offline() function for @cdev, if
268  * given, and then disables @cdev.
269  * Returns:
270  *   %0 on success and a negative error value on failure.
271  * Context:
272  *  enabled, ccw device lock not held
273  */
ccw_device_set_offline(struct ccw_device * cdev)274 int ccw_device_set_offline(struct ccw_device *cdev)
275 {
276 	struct subchannel *sch;
277 	int ret, state;
278 
279 	if (!cdev)
280 		return -ENODEV;
281 	if (!cdev->online || !cdev->drv)
282 		return -EINVAL;
283 
284 	if (cdev->drv->set_offline) {
285 		ret = cdev->drv->set_offline(cdev);
286 		if (ret != 0)
287 			return ret;
288 	}
289 	spin_lock_irq(cdev->ccwlock);
290 	sch = to_subchannel(cdev->dev.parent);
291 	cdev->online = 0;
292 	/* Wait until a final state or DISCONNECTED is reached */
293 	while (!dev_fsm_final_state(cdev) &&
294 	       cdev->private->state != DEV_STATE_DISCONNECTED) {
295 		spin_unlock_irq(cdev->ccwlock);
296 		wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
297 			   cdev->private->state == DEV_STATE_DISCONNECTED));
298 		spin_lock_irq(cdev->ccwlock);
299 	}
300 	do {
301 		ret = ccw_device_offline(cdev);
302 		if (!ret)
303 			break;
304 		CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
305 			      "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
306 			      cdev->private->dev_id.devno);
307 		if (ret != -EBUSY)
308 			goto error;
309 		state = cdev->private->state;
310 		spin_unlock_irq(cdev->ccwlock);
311 		io_subchannel_quiesce(sch);
312 		spin_lock_irq(cdev->ccwlock);
313 		cdev->private->state = state;
314 	} while (ret == -EBUSY);
315 	spin_unlock_irq(cdev->ccwlock);
316 	wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
317 		   cdev->private->state == DEV_STATE_DISCONNECTED));
318 	/* Inform the user if set offline failed. */
319 	if (cdev->private->state == DEV_STATE_BOXED) {
320 		pr_warn("%s: The device entered boxed state while being set offline\n",
321 			dev_name(&cdev->dev));
322 	} else if (cdev->private->state == DEV_STATE_NOT_OPER) {
323 		pr_warn("%s: The device stopped operating while being set offline\n",
324 			dev_name(&cdev->dev));
325 	}
326 	/* Give up reference from ccw_device_set_online(). */
327 	put_device(&cdev->dev);
328 	return 0;
329 
330 error:
331 	cdev->private->state = DEV_STATE_OFFLINE;
332 	dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
333 	spin_unlock_irq(cdev->ccwlock);
334 	/* Give up reference from ccw_device_set_online(). */
335 	put_device(&cdev->dev);
336 	return -ENODEV;
337 }
338 
339 /**
340  * ccw_device_set_online() - enable a ccw device for I/O
341  * @cdev: target ccw device
342  *
343  * This function first enables @cdev and then calls the driver's set_online()
344  * function for @cdev, if given. If set_online() returns an error, @cdev is
345  * disabled again.
346  * Returns:
347  *   %0 on success and a negative error value on failure.
348  * Context:
349  *  enabled, ccw device lock not held
350  */
ccw_device_set_online(struct ccw_device * cdev)351 int ccw_device_set_online(struct ccw_device *cdev)
352 {
353 	int ret;
354 	int ret2;
355 
356 	if (!cdev)
357 		return -ENODEV;
358 	if (cdev->online || !cdev->drv)
359 		return -EINVAL;
360 	/* Hold on to an extra reference while device is online. */
361 	if (!get_device(&cdev->dev))
362 		return -ENODEV;
363 
364 	spin_lock_irq(cdev->ccwlock);
365 	ret = ccw_device_online(cdev);
366 	if (ret) {
367 		spin_unlock_irq(cdev->ccwlock);
368 		CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
369 			      "device 0.%x.%04x\n",
370 			      ret, cdev->private->dev_id.ssid,
371 			      cdev->private->dev_id.devno);
372 		/* Give up online reference since onlining failed. */
373 		put_device(&cdev->dev);
374 		return ret;
375 	}
376 	/* Wait until a final state is reached */
377 	while (!dev_fsm_final_state(cdev)) {
378 		spin_unlock_irq(cdev->ccwlock);
379 		wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
380 		spin_lock_irq(cdev->ccwlock);
381 	}
382 	/* Check if online processing was successful */
383 	if ((cdev->private->state != DEV_STATE_ONLINE) &&
384 	    (cdev->private->state != DEV_STATE_W4SENSE)) {
385 		spin_unlock_irq(cdev->ccwlock);
386 		/* Inform the user that set online failed. */
387 		if (cdev->private->state == DEV_STATE_BOXED) {
388 			pr_warn("%s: Setting the device online failed because it is boxed\n",
389 				dev_name(&cdev->dev));
390 		} else if (cdev->private->state == DEV_STATE_NOT_OPER) {
391 			pr_warn("%s: Setting the device online failed because it is not operational\n",
392 				dev_name(&cdev->dev));
393 		}
394 		/* Give up online reference since onlining failed. */
395 		put_device(&cdev->dev);
396 		return -ENODEV;
397 	}
398 	spin_unlock_irq(cdev->ccwlock);
399 	if (cdev->drv->set_online)
400 		ret = cdev->drv->set_online(cdev);
401 	if (ret)
402 		goto rollback;
403 
404 	spin_lock_irq(cdev->ccwlock);
405 	cdev->online = 1;
406 	spin_unlock_irq(cdev->ccwlock);
407 	return 0;
408 
409 rollback:
410 	spin_lock_irq(cdev->ccwlock);
411 	/* Wait until a final state or DISCONNECTED is reached */
412 	while (!dev_fsm_final_state(cdev) &&
413 	       cdev->private->state != DEV_STATE_DISCONNECTED) {
414 		spin_unlock_irq(cdev->ccwlock);
415 		wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
416 			   cdev->private->state == DEV_STATE_DISCONNECTED));
417 		spin_lock_irq(cdev->ccwlock);
418 	}
419 	ret2 = ccw_device_offline(cdev);
420 	if (ret2)
421 		goto error;
422 	spin_unlock_irq(cdev->ccwlock);
423 	wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
424 		   cdev->private->state == DEV_STATE_DISCONNECTED));
425 	/* Give up online reference since onlining failed. */
426 	put_device(&cdev->dev);
427 	return ret;
428 
429 error:
430 	CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
431 		      "device 0.%x.%04x\n",
432 		      ret2, cdev->private->dev_id.ssid,
433 		      cdev->private->dev_id.devno);
434 	cdev->private->state = DEV_STATE_OFFLINE;
435 	spin_unlock_irq(cdev->ccwlock);
436 	/* Give up online reference since onlining failed. */
437 	put_device(&cdev->dev);
438 	return ret;
439 }
440 
online_store_handle_offline(struct ccw_device * cdev)441 static int online_store_handle_offline(struct ccw_device *cdev)
442 {
443 	if (cdev->private->state == DEV_STATE_DISCONNECTED) {
444 		spin_lock_irq(cdev->ccwlock);
445 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
446 		spin_unlock_irq(cdev->ccwlock);
447 		return 0;
448 	}
449 	if (cdev->drv && cdev->drv->set_offline)
450 		return ccw_device_set_offline(cdev);
451 	return -EINVAL;
452 }
453 
online_store_recog_and_online(struct ccw_device * cdev)454 static int online_store_recog_and_online(struct ccw_device *cdev)
455 {
456 	/* Do device recognition, if needed. */
457 	if (cdev->private->state == DEV_STATE_BOXED) {
458 		spin_lock_irq(cdev->ccwlock);
459 		ccw_device_recognition(cdev);
460 		spin_unlock_irq(cdev->ccwlock);
461 		wait_event(cdev->private->wait_q,
462 			   cdev->private->flags.recog_done);
463 		if (cdev->private->state != DEV_STATE_OFFLINE)
464 			/* recognition failed */
465 			return -EAGAIN;
466 	}
467 	if (cdev->drv && cdev->drv->set_online)
468 		return ccw_device_set_online(cdev);
469 	return -EINVAL;
470 }
471 
online_store_handle_online(struct ccw_device * cdev,int force)472 static int online_store_handle_online(struct ccw_device *cdev, int force)
473 {
474 	int ret;
475 
476 	ret = online_store_recog_and_online(cdev);
477 	if (ret && !force)
478 		return ret;
479 	if (force && cdev->private->state == DEV_STATE_BOXED) {
480 		ret = ccw_device_stlck(cdev);
481 		if (ret)
482 			return ret;
483 		if (cdev->id.cu_type == 0)
484 			cdev->private->state = DEV_STATE_NOT_OPER;
485 		ret = online_store_recog_and_online(cdev);
486 		if (ret)
487 			return ret;
488 	}
489 	return 0;
490 }
491 
online_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)492 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
493 			     const char *buf, size_t count)
494 {
495 	struct ccw_device *cdev = to_ccwdev(dev);
496 	int force, ret;
497 	unsigned long i;
498 
499 	/* Prevent conflict between multiple on-/offline processing requests. */
500 	if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
501 		return -EAGAIN;
502 	/* Prevent conflict between internal I/Os and on-/offline processing. */
503 	if (!dev_fsm_final_state(cdev) &&
504 	    cdev->private->state != DEV_STATE_DISCONNECTED) {
505 		ret = -EAGAIN;
506 		goto out;
507 	}
508 	/* Prevent conflict between pending work and on-/offline processing.*/
509 	if (work_pending(&cdev->private->todo_work)) {
510 		ret = -EAGAIN;
511 		goto out;
512 	}
513 	if (!strncmp(buf, "force\n", count)) {
514 		force = 1;
515 		i = 1;
516 		ret = 0;
517 	} else {
518 		force = 0;
519 		ret = kstrtoul(buf, 16, &i);
520 	}
521 	if (ret)
522 		goto out;
523 
524 	device_lock(dev);
525 	switch (i) {
526 	case 0:
527 		ret = online_store_handle_offline(cdev);
528 		break;
529 	case 1:
530 		ret = online_store_handle_online(cdev, force);
531 		break;
532 	default:
533 		ret = -EINVAL;
534 	}
535 	device_unlock(dev);
536 
537 out:
538 	atomic_set(&cdev->private->onoff, 0);
539 	return (ret < 0) ? ret : count;
540 }
541 
542 static ssize_t
available_show(struct device * dev,struct device_attribute * attr,char * buf)543 available_show (struct device *dev, struct device_attribute *attr, char *buf)
544 {
545 	struct ccw_device *cdev = to_ccwdev(dev);
546 	struct subchannel *sch;
547 
548 	if (ccw_device_is_orphan(cdev))
549 		return sprintf(buf, "no device\n");
550 	switch (cdev->private->state) {
551 	case DEV_STATE_BOXED:
552 		return sprintf(buf, "boxed\n");
553 	case DEV_STATE_DISCONNECTED:
554 	case DEV_STATE_DISCONNECTED_SENSE_ID:
555 	case DEV_STATE_NOT_OPER:
556 		sch = to_subchannel(dev->parent);
557 		if (!sch->lpm)
558 			return sprintf(buf, "no path\n");
559 		else
560 			return sprintf(buf, "no device\n");
561 	default:
562 		/* All other states considered fine. */
563 		return sprintf(buf, "good\n");
564 	}
565 }
566 
567 static ssize_t
initiate_logging(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)568 initiate_logging(struct device *dev, struct device_attribute *attr,
569 		 const char *buf, size_t count)
570 {
571 	struct subchannel *sch = to_subchannel(dev);
572 	int rc;
573 
574 	rc = chsc_siosl(sch->schid);
575 	if (rc < 0) {
576 		pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
577 			sch->schid.ssid, sch->schid.sch_no, rc);
578 		return rc;
579 	}
580 	pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
581 		  sch->schid.ssid, sch->schid.sch_no);
582 	return count;
583 }
584 
vpm_show(struct device * dev,struct device_attribute * attr,char * buf)585 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
586 			char *buf)
587 {
588 	struct subchannel *sch = to_subchannel(dev);
589 
590 	return sprintf(buf, "%02x\n", sch->vpm);
591 }
592 
593 static DEVICE_ATTR_RO(devtype);
594 static DEVICE_ATTR_RO(cutype);
595 static DEVICE_ATTR_RO(modalias);
596 static DEVICE_ATTR_RW(online);
597 static DEVICE_ATTR(availability, 0444, available_show, NULL);
598 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
599 static DEVICE_ATTR_RO(vpm);
600 
601 static struct attribute *io_subchannel_attrs[] = {
602 	&dev_attr_logging.attr,
603 	&dev_attr_vpm.attr,
604 	NULL,
605 };
606 
607 static const struct attribute_group io_subchannel_attr_group = {
608 	.attrs = io_subchannel_attrs,
609 };
610 
611 static struct attribute * ccwdev_attrs[] = {
612 	&dev_attr_devtype.attr,
613 	&dev_attr_cutype.attr,
614 	&dev_attr_modalias.attr,
615 	&dev_attr_online.attr,
616 	&dev_attr_cmb_enable.attr,
617 	&dev_attr_availability.attr,
618 	NULL,
619 };
620 
621 static const struct attribute_group ccwdev_attr_group = {
622 	.attrs = ccwdev_attrs,
623 };
624 
625 static const struct attribute_group *ccwdev_attr_groups[] = {
626 	&ccwdev_attr_group,
627 	NULL,
628 };
629 
match_dev_id(struct device * dev,const void * data)630 static int match_dev_id(struct device *dev, const void *data)
631 {
632 	struct ccw_device *cdev = to_ccwdev(dev);
633 	struct ccw_dev_id *dev_id = (void *)data;
634 
635 	return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
636 }
637 
638 /**
639  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
640  * @dev_id: id of the device to be searched
641  *
642  * This function searches all devices attached to the ccw bus for a device
643  * matching @dev_id.
644  * Returns:
645  *  If a device is found its reference count is increased and returned;
646  *  else %NULL is returned.
647  */
get_ccwdev_by_dev_id(struct ccw_dev_id * dev_id)648 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
649 {
650 	struct device *dev;
651 
652 	dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
653 
654 	return dev ? to_ccwdev(dev) : NULL;
655 }
656 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
657 
ccw_device_do_unbind_bind(struct ccw_device * cdev)658 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
659 {
660 	int ret;
661 
662 	mutex_lock(&cdev->reg_mutex);
663 	if (device_is_registered(&cdev->dev)) {
664 		device_release_driver(&cdev->dev);
665 		ret = device_attach(&cdev->dev);
666 		WARN_ON(ret == -ENODEV);
667 	}
668 	mutex_unlock(&cdev->reg_mutex);
669 }
670 
671 static void
ccw_device_release(struct device * dev)672 ccw_device_release(struct device *dev)
673 {
674 	struct ccw_device *cdev;
675 
676 	cdev = to_ccwdev(dev);
677 	cio_gp_dma_free(cdev->private->dma_pool, cdev->private->dma_area,
678 			sizeof(*cdev->private->dma_area));
679 	cio_gp_dma_destroy(cdev->private->dma_pool, &cdev->dev);
680 	/* Release reference of parent subchannel. */
681 	put_device(cdev->dev.parent);
682 	kfree(cdev->private);
683 	kfree(cdev);
684 }
685 
io_subchannel_allocate_dev(struct subchannel * sch)686 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
687 {
688 	struct ccw_device *cdev;
689 	struct gen_pool *dma_pool;
690 	int ret;
691 
692 	cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
693 	if (!cdev) {
694 		ret = -ENOMEM;
695 		goto err_cdev;
696 	}
697 	cdev->private = kzalloc(sizeof(struct ccw_device_private),
698 				GFP_KERNEL | GFP_DMA);
699 	if (!cdev->private) {
700 		ret = -ENOMEM;
701 		goto err_priv;
702 	}
703 
704 	cdev->dev.dma_mask = sch->dev.dma_mask;
705 	ret = dma_set_coherent_mask(&cdev->dev, sch->dev.coherent_dma_mask);
706 	if (ret)
707 		goto err_coherent_mask;
708 
709 	dma_pool = cio_gp_dma_create(&cdev->dev, 1);
710 	if (!dma_pool) {
711 		ret = -ENOMEM;
712 		goto err_dma_pool;
713 	}
714 	cdev->private->dma_pool = dma_pool;
715 	cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
716 					sizeof(*cdev->private->dma_area));
717 	if (!cdev->private->dma_area) {
718 		ret = -ENOMEM;
719 		goto err_dma_area;
720 	}
721 	return cdev;
722 err_dma_area:
723 	cio_gp_dma_destroy(dma_pool, &cdev->dev);
724 err_dma_pool:
725 err_coherent_mask:
726 	kfree(cdev->private);
727 err_priv:
728 	kfree(cdev);
729 err_cdev:
730 	return ERR_PTR(ret);
731 }
732 
733 static void ccw_device_todo(struct work_struct *work);
734 
io_subchannel_initialize_dev(struct subchannel * sch,struct ccw_device * cdev)735 static int io_subchannel_initialize_dev(struct subchannel *sch,
736 					struct ccw_device *cdev)
737 {
738 	struct ccw_device_private *priv = cdev->private;
739 	int ret;
740 
741 	priv->cdev = cdev;
742 	priv->int_class = IRQIO_CIO;
743 	priv->state = DEV_STATE_NOT_OPER;
744 	priv->dev_id.devno = sch->schib.pmcw.dev;
745 	priv->dev_id.ssid = sch->schid.ssid;
746 
747 	INIT_WORK(&priv->todo_work, ccw_device_todo);
748 	INIT_LIST_HEAD(&priv->cmb_list);
749 	init_waitqueue_head(&priv->wait_q);
750 	timer_setup(&priv->timer, ccw_device_timeout, 0);
751 	mutex_init(&cdev->reg_mutex);
752 
753 	atomic_set(&priv->onoff, 0);
754 	cdev->ccwlock = sch->lock;
755 	cdev->dev.parent = &sch->dev;
756 	cdev->dev.release = ccw_device_release;
757 	cdev->dev.bus = &ccw_bus_type;
758 	cdev->dev.groups = ccwdev_attr_groups;
759 	/* Do first half of device_register. */
760 	device_initialize(&cdev->dev);
761 	ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
762 			   cdev->private->dev_id.devno);
763 	if (ret)
764 		goto out_put;
765 	if (!get_device(&sch->dev)) {
766 		ret = -ENODEV;
767 		goto out_put;
768 	}
769 	priv->flags.initialized = 1;
770 	spin_lock_irq(sch->lock);
771 	sch_set_cdev(sch, cdev);
772 	spin_unlock_irq(sch->lock);
773 	return 0;
774 
775 out_put:
776 	/* Release reference from device_initialize(). */
777 	put_device(&cdev->dev);
778 	return ret;
779 }
780 
io_subchannel_create_ccwdev(struct subchannel * sch)781 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
782 {
783 	struct ccw_device *cdev;
784 	int ret;
785 
786 	cdev = io_subchannel_allocate_dev(sch);
787 	if (!IS_ERR(cdev)) {
788 		ret = io_subchannel_initialize_dev(sch, cdev);
789 		if (ret)
790 			cdev = ERR_PTR(ret);
791 	}
792 	return cdev;
793 }
794 
795 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
796 
sch_create_and_recog_new_device(struct subchannel * sch)797 static void sch_create_and_recog_new_device(struct subchannel *sch)
798 {
799 	struct ccw_device *cdev;
800 
801 	/* Need to allocate a new ccw device. */
802 	cdev = io_subchannel_create_ccwdev(sch);
803 	if (IS_ERR(cdev)) {
804 		/* OK, we did everything we could... */
805 		css_sch_device_unregister(sch);
806 		return;
807 	}
808 	/* Start recognition for the new ccw device. */
809 	io_subchannel_recog(cdev, sch);
810 }
811 
812 /*
813  * Register recognized device.
814  */
io_subchannel_register(struct ccw_device * cdev)815 static void io_subchannel_register(struct ccw_device *cdev)
816 {
817 	struct subchannel *sch;
818 	int ret, adjust_init_count = 1;
819 	unsigned long flags;
820 
821 	sch = to_subchannel(cdev->dev.parent);
822 	/*
823 	 * Check if subchannel is still registered. It may have become
824 	 * unregistered if a machine check hit us after finishing
825 	 * device recognition but before the register work could be
826 	 * queued.
827 	 */
828 	if (!device_is_registered(&sch->dev))
829 		goto out_err;
830 	css_update_ssd_info(sch);
831 	/*
832 	 * io_subchannel_register() will also be called after device
833 	 * recognition has been done for a boxed device (which will already
834 	 * be registered). We need to reprobe since we may now have sense id
835 	 * information.
836 	 */
837 	mutex_lock(&cdev->reg_mutex);
838 	if (device_is_registered(&cdev->dev)) {
839 		if (!cdev->drv) {
840 			ret = device_reprobe(&cdev->dev);
841 			if (ret)
842 				/* We can't do much here. */
843 				CIO_MSG_EVENT(0, "device_reprobe() returned"
844 					      " %d for 0.%x.%04x\n", ret,
845 					      cdev->private->dev_id.ssid,
846 					      cdev->private->dev_id.devno);
847 		}
848 		adjust_init_count = 0;
849 		goto out;
850 	}
851 	/* make it known to the system */
852 	ret = device_add(&cdev->dev);
853 	if (ret) {
854 		CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
855 			      cdev->private->dev_id.ssid,
856 			      cdev->private->dev_id.devno, ret);
857 		spin_lock_irqsave(sch->lock, flags);
858 		sch_set_cdev(sch, NULL);
859 		spin_unlock_irqrestore(sch->lock, flags);
860 		mutex_unlock(&cdev->reg_mutex);
861 		/* Release initial device reference. */
862 		put_device(&cdev->dev);
863 		goto out_err;
864 	}
865 out:
866 	cdev->private->flags.recog_done = 1;
867 	mutex_unlock(&cdev->reg_mutex);
868 	wake_up(&cdev->private->wait_q);
869 out_err:
870 	if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
871 		wake_up(&ccw_device_init_wq);
872 }
873 
874 /*
875  * subchannel recognition done. Called from the state machine.
876  */
877 void
io_subchannel_recog_done(struct ccw_device * cdev)878 io_subchannel_recog_done(struct ccw_device *cdev)
879 {
880 	if (css_init_done == 0) {
881 		cdev->private->flags.recog_done = 1;
882 		return;
883 	}
884 	switch (cdev->private->state) {
885 	case DEV_STATE_BOXED:
886 		/* Device did not respond in time. */
887 	case DEV_STATE_NOT_OPER:
888 		cdev->private->flags.recog_done = 1;
889 		/* Remove device found not operational. */
890 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
891 		if (atomic_dec_and_test(&ccw_device_init_count))
892 			wake_up(&ccw_device_init_wq);
893 		break;
894 	case DEV_STATE_OFFLINE:
895 		/*
896 		 * We can't register the device in interrupt context so
897 		 * we schedule a work item.
898 		 */
899 		ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
900 		break;
901 	}
902 }
903 
io_subchannel_recog(struct ccw_device * cdev,struct subchannel * sch)904 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
905 {
906 	/* Increase counter of devices currently in recognition. */
907 	atomic_inc(&ccw_device_init_count);
908 
909 	/* Start async. device sensing. */
910 	spin_lock_irq(sch->lock);
911 	ccw_device_recognition(cdev);
912 	spin_unlock_irq(sch->lock);
913 }
914 
ccw_device_move_to_sch(struct ccw_device * cdev,struct subchannel * sch)915 static int ccw_device_move_to_sch(struct ccw_device *cdev,
916 				  struct subchannel *sch)
917 {
918 	struct subchannel *old_sch;
919 	int rc, old_enabled = 0;
920 
921 	old_sch = to_subchannel(cdev->dev.parent);
922 	/* Obtain child reference for new parent. */
923 	if (!get_device(&sch->dev))
924 		return -ENODEV;
925 
926 	if (!sch_is_pseudo_sch(old_sch)) {
927 		spin_lock_irq(old_sch->lock);
928 		old_enabled = old_sch->schib.pmcw.ena;
929 		rc = 0;
930 		if (old_enabled)
931 			rc = cio_disable_subchannel(old_sch);
932 		spin_unlock_irq(old_sch->lock);
933 		if (rc == -EBUSY) {
934 			/* Release child reference for new parent. */
935 			put_device(&sch->dev);
936 			return rc;
937 		}
938 	}
939 
940 	mutex_lock(&sch->reg_mutex);
941 	rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
942 	mutex_unlock(&sch->reg_mutex);
943 	if (rc) {
944 		CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
945 			      cdev->private->dev_id.ssid,
946 			      cdev->private->dev_id.devno, sch->schid.ssid,
947 			      sch->schib.pmcw.dev, rc);
948 		if (old_enabled) {
949 			/* Try to re-enable the old subchannel. */
950 			spin_lock_irq(old_sch->lock);
951 			cio_enable_subchannel(old_sch, (u32)virt_to_phys(old_sch));
952 			spin_unlock_irq(old_sch->lock);
953 		}
954 		/* Release child reference for new parent. */
955 		put_device(&sch->dev);
956 		return rc;
957 	}
958 	/* Clean up old subchannel. */
959 	if (!sch_is_pseudo_sch(old_sch)) {
960 		spin_lock_irq(old_sch->lock);
961 		sch_set_cdev(old_sch, NULL);
962 		spin_unlock_irq(old_sch->lock);
963 		css_schedule_eval(old_sch->schid);
964 	}
965 	/* Release child reference for old parent. */
966 	put_device(&old_sch->dev);
967 	/* Initialize new subchannel. */
968 	spin_lock_irq(sch->lock);
969 	cdev->ccwlock = sch->lock;
970 	if (!sch_is_pseudo_sch(sch))
971 		sch_set_cdev(sch, cdev);
972 	spin_unlock_irq(sch->lock);
973 	if (!sch_is_pseudo_sch(sch))
974 		css_update_ssd_info(sch);
975 	return 0;
976 }
977 
ccw_device_move_to_orph(struct ccw_device * cdev)978 static int ccw_device_move_to_orph(struct ccw_device *cdev)
979 {
980 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
981 	struct channel_subsystem *css = to_css(sch->dev.parent);
982 
983 	return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
984 }
985 
io_subchannel_irq(struct subchannel * sch)986 static void io_subchannel_irq(struct subchannel *sch)
987 {
988 	struct ccw_device *cdev;
989 
990 	cdev = sch_get_cdev(sch);
991 
992 	CIO_TRACE_EVENT(6, "IRQ");
993 	CIO_TRACE_EVENT(6, dev_name(&sch->dev));
994 	if (cdev)
995 		dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
996 	else
997 		inc_irq_stat(IRQIO_CIO);
998 }
999 
io_subchannel_init_config(struct subchannel * sch)1000 void io_subchannel_init_config(struct subchannel *sch)
1001 {
1002 	memset(&sch->config, 0, sizeof(sch->config));
1003 	sch->config.csense = 1;
1004 }
1005 
io_subchannel_init_fields(struct subchannel * sch)1006 static void io_subchannel_init_fields(struct subchannel *sch)
1007 {
1008 	if (cio_is_console(sch->schid))
1009 		sch->opm = 0xff;
1010 	else
1011 		sch->opm = chp_get_sch_opm(sch);
1012 	sch->lpm = sch->schib.pmcw.pam & sch->opm;
1013 	sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1014 
1015 	CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1016 		      " - PIM = %02X, PAM = %02X, POM = %02X\n",
1017 		      sch->schib.pmcw.dev, sch->schid.ssid,
1018 		      sch->schid.sch_no, sch->schib.pmcw.pim,
1019 		      sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1020 
1021 	io_subchannel_init_config(sch);
1022 }
1023 
1024 /*
1025  * Note: We always return 0 so that we bind to the device even on error.
1026  * This is needed so that our remove function is called on unregister.
1027  */
io_subchannel_probe(struct subchannel * sch)1028 static int io_subchannel_probe(struct subchannel *sch)
1029 {
1030 	struct io_subchannel_private *io_priv;
1031 	struct ccw_device *cdev;
1032 	int rc;
1033 
1034 	if (cio_is_console(sch->schid)) {
1035 		rc = sysfs_create_group(&sch->dev.kobj,
1036 					&io_subchannel_attr_group);
1037 		if (rc)
1038 			CIO_MSG_EVENT(0, "Failed to create io subchannel "
1039 				      "attributes for subchannel "
1040 				      "0.%x.%04x (rc=%d)\n",
1041 				      sch->schid.ssid, sch->schid.sch_no, rc);
1042 		/*
1043 		* The console subchannel already has an associated ccw_device.
1044 		* Register it and exit.
1045 		*/
1046 		cdev = sch_get_cdev(sch);
1047 		rc = device_add(&cdev->dev);
1048 		if (rc) {
1049 			/* Release online reference. */
1050 			put_device(&cdev->dev);
1051 			goto out_schedule;
1052 		}
1053 		if (atomic_dec_and_test(&ccw_device_init_count))
1054 			wake_up(&ccw_device_init_wq);
1055 		return 0;
1056 	}
1057 	io_subchannel_init_fields(sch);
1058 	rc = cio_commit_config(sch);
1059 	if (rc)
1060 		goto out_schedule;
1061 	rc = sysfs_create_group(&sch->dev.kobj,
1062 				&io_subchannel_attr_group);
1063 	if (rc)
1064 		goto out_schedule;
1065 	/* Allocate I/O subchannel private data. */
1066 	io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1067 	if (!io_priv)
1068 		goto out_schedule;
1069 
1070 	io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1071 				sizeof(*io_priv->dma_area),
1072 				&io_priv->dma_area_dma, GFP_KERNEL);
1073 	if (!io_priv->dma_area) {
1074 		kfree(io_priv);
1075 		goto out_schedule;
1076 	}
1077 
1078 	set_io_private(sch, io_priv);
1079 	css_schedule_eval(sch->schid);
1080 	return 0;
1081 
1082 out_schedule:
1083 	spin_lock_irq(sch->lock);
1084 	css_sched_sch_todo(sch, SCH_TODO_UNREG);
1085 	spin_unlock_irq(sch->lock);
1086 	return 0;
1087 }
1088 
io_subchannel_remove(struct subchannel * sch)1089 static void io_subchannel_remove(struct subchannel *sch)
1090 {
1091 	struct io_subchannel_private *io_priv = to_io_private(sch);
1092 	struct ccw_device *cdev;
1093 
1094 	cdev = sch_get_cdev(sch);
1095 	if (!cdev)
1096 		goto out_free;
1097 
1098 	ccw_device_unregister(cdev);
1099 	spin_lock_irq(sch->lock);
1100 	sch_set_cdev(sch, NULL);
1101 	set_io_private(sch, NULL);
1102 	spin_unlock_irq(sch->lock);
1103 out_free:
1104 	dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1105 			  io_priv->dma_area, io_priv->dma_area_dma);
1106 	kfree(io_priv);
1107 	sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1108 }
1109 
io_subchannel_verify(struct subchannel * sch)1110 static void io_subchannel_verify(struct subchannel *sch)
1111 {
1112 	struct ccw_device *cdev;
1113 
1114 	cdev = sch_get_cdev(sch);
1115 	if (cdev)
1116 		dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1117 	else
1118 		css_schedule_eval(sch->schid);
1119 }
1120 
io_subchannel_terminate_path(struct subchannel * sch,u8 mask)1121 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1122 {
1123 	struct ccw_device *cdev;
1124 
1125 	cdev = sch_get_cdev(sch);
1126 	if (!cdev)
1127 		return;
1128 	if (cio_update_schib(sch))
1129 		goto err;
1130 	/* Check for I/O on path. */
1131 	if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1132 		goto out;
1133 	if (cdev->private->state == DEV_STATE_ONLINE) {
1134 		ccw_device_kill_io(cdev);
1135 		goto out;
1136 	}
1137 	if (cio_clear(sch))
1138 		goto err;
1139 out:
1140 	/* Trigger path verification. */
1141 	dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1142 	return;
1143 
1144 err:
1145 	dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1146 }
1147 
io_subchannel_chp_event(struct subchannel * sch,struct chp_link * link,int event)1148 static int io_subchannel_chp_event(struct subchannel *sch,
1149 				   struct chp_link *link, int event)
1150 {
1151 	struct ccw_device *cdev = sch_get_cdev(sch);
1152 	int mask, chpid, valid_bit;
1153 	int path_event[8];
1154 
1155 	mask = chp_ssd_get_mask(&sch->ssd_info, link);
1156 	if (!mask)
1157 		return 0;
1158 	switch (event) {
1159 	case CHP_VARY_OFF:
1160 		sch->opm &= ~mask;
1161 		sch->lpm &= ~mask;
1162 		if (cdev)
1163 			cdev->private->path_gone_mask |= mask;
1164 		io_subchannel_terminate_path(sch, mask);
1165 		break;
1166 	case CHP_VARY_ON:
1167 		sch->opm |= mask;
1168 		sch->lpm |= mask;
1169 		if (cdev)
1170 			cdev->private->path_new_mask |= mask;
1171 		io_subchannel_verify(sch);
1172 		break;
1173 	case CHP_OFFLINE:
1174 		if (cio_update_schib(sch))
1175 			return -ENODEV;
1176 		if (cdev)
1177 			cdev->private->path_gone_mask |= mask;
1178 		io_subchannel_terminate_path(sch, mask);
1179 		break;
1180 	case CHP_ONLINE:
1181 		if (cio_update_schib(sch))
1182 			return -ENODEV;
1183 		sch->lpm |= mask & sch->opm;
1184 		if (cdev)
1185 			cdev->private->path_new_mask |= mask;
1186 		io_subchannel_verify(sch);
1187 		break;
1188 	case CHP_FCES_EVENT:
1189 		/* Forward Endpoint Security event */
1190 		for (chpid = 0, valid_bit = 0x80; chpid < 8; chpid++,
1191 				valid_bit >>= 1) {
1192 			if (mask & valid_bit)
1193 				path_event[chpid] = PE_PATH_FCES_EVENT;
1194 			else
1195 				path_event[chpid] = PE_NONE;
1196 		}
1197 		if (cdev && cdev->drv && cdev->drv->path_event)
1198 			cdev->drv->path_event(cdev, path_event);
1199 		break;
1200 	}
1201 	return 0;
1202 }
1203 
io_subchannel_quiesce(struct subchannel * sch)1204 static void io_subchannel_quiesce(struct subchannel *sch)
1205 {
1206 	struct ccw_device *cdev;
1207 	int ret;
1208 
1209 	spin_lock_irq(sch->lock);
1210 	cdev = sch_get_cdev(sch);
1211 	if (cio_is_console(sch->schid))
1212 		goto out_unlock;
1213 	if (!sch->schib.pmcw.ena)
1214 		goto out_unlock;
1215 	ret = cio_disable_subchannel(sch);
1216 	if (ret != -EBUSY)
1217 		goto out_unlock;
1218 	if (cdev->handler)
1219 		cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1220 	while (ret == -EBUSY) {
1221 		cdev->private->state = DEV_STATE_QUIESCE;
1222 		cdev->private->iretry = 255;
1223 		ret = ccw_device_cancel_halt_clear(cdev);
1224 		if (ret == -EBUSY) {
1225 			ccw_device_set_timeout(cdev, HZ/10);
1226 			spin_unlock_irq(sch->lock);
1227 			wait_event(cdev->private->wait_q,
1228 				   cdev->private->state != DEV_STATE_QUIESCE);
1229 			spin_lock_irq(sch->lock);
1230 		}
1231 		ret = cio_disable_subchannel(sch);
1232 	}
1233 out_unlock:
1234 	spin_unlock_irq(sch->lock);
1235 }
1236 
io_subchannel_shutdown(struct subchannel * sch)1237 static void io_subchannel_shutdown(struct subchannel *sch)
1238 {
1239 	io_subchannel_quiesce(sch);
1240 }
1241 
device_is_disconnected(struct ccw_device * cdev)1242 static int device_is_disconnected(struct ccw_device *cdev)
1243 {
1244 	if (!cdev)
1245 		return 0;
1246 	return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1247 		cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1248 }
1249 
recovery_check(struct device * dev,void * data)1250 static int recovery_check(struct device *dev, void *data)
1251 {
1252 	struct ccw_device *cdev = to_ccwdev(dev);
1253 	struct subchannel *sch;
1254 	int *redo = data;
1255 
1256 	spin_lock_irq(cdev->ccwlock);
1257 	switch (cdev->private->state) {
1258 	case DEV_STATE_ONLINE:
1259 		sch = to_subchannel(cdev->dev.parent);
1260 		if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1261 			break;
1262 		fallthrough;
1263 	case DEV_STATE_DISCONNECTED:
1264 		CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1265 			      cdev->private->dev_id.ssid,
1266 			      cdev->private->dev_id.devno);
1267 		dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1268 		*redo = 1;
1269 		break;
1270 	case DEV_STATE_DISCONNECTED_SENSE_ID:
1271 		*redo = 1;
1272 		break;
1273 	}
1274 	spin_unlock_irq(cdev->ccwlock);
1275 
1276 	return 0;
1277 }
1278 
recovery_work_func(struct work_struct * unused)1279 static void recovery_work_func(struct work_struct *unused)
1280 {
1281 	int redo = 0;
1282 
1283 	bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1284 	if (redo) {
1285 		spin_lock_irq(&recovery_lock);
1286 		if (!timer_pending(&recovery_timer)) {
1287 			if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1288 				recovery_phase++;
1289 			mod_timer(&recovery_timer, jiffies +
1290 				  recovery_delay[recovery_phase] * HZ);
1291 		}
1292 		spin_unlock_irq(&recovery_lock);
1293 	} else
1294 		CIO_MSG_EVENT(3, "recovery: end\n");
1295 }
1296 
1297 static DECLARE_WORK(recovery_work, recovery_work_func);
1298 
recovery_func(struct timer_list * unused)1299 static void recovery_func(struct timer_list *unused)
1300 {
1301 	/*
1302 	 * We can't do our recovery in softirq context and it's not
1303 	 * performance critical, so we schedule it.
1304 	 */
1305 	schedule_work(&recovery_work);
1306 }
1307 
ccw_device_schedule_recovery(void)1308 void ccw_device_schedule_recovery(void)
1309 {
1310 	unsigned long flags;
1311 
1312 	CIO_MSG_EVENT(3, "recovery: schedule\n");
1313 	spin_lock_irqsave(&recovery_lock, flags);
1314 	if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1315 		recovery_phase = 0;
1316 		mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1317 	}
1318 	spin_unlock_irqrestore(&recovery_lock, flags);
1319 }
1320 
purge_fn(struct device * dev,void * data)1321 static int purge_fn(struct device *dev, void *data)
1322 {
1323 	struct ccw_device *cdev = to_ccwdev(dev);
1324 	struct ccw_dev_id *id = &cdev->private->dev_id;
1325 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
1326 
1327 	spin_lock_irq(cdev->ccwlock);
1328 	if (is_blacklisted(id->ssid, id->devno) &&
1329 	    (cdev->private->state == DEV_STATE_OFFLINE) &&
1330 	    (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1331 		CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1332 			      id->devno);
1333 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1334 		css_sched_sch_todo(sch, SCH_TODO_UNREG);
1335 		atomic_set(&cdev->private->onoff, 0);
1336 	}
1337 	spin_unlock_irq(cdev->ccwlock);
1338 	/* Abort loop in case of pending signal. */
1339 	if (signal_pending(current))
1340 		return -EINTR;
1341 
1342 	return 0;
1343 }
1344 
1345 /**
1346  * ccw_purge_blacklisted - purge unused, blacklisted devices
1347  *
1348  * Unregister all ccw devices that are offline and on the blacklist.
1349  */
ccw_purge_blacklisted(void)1350 int ccw_purge_blacklisted(void)
1351 {
1352 	CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1353 	bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1354 	return 0;
1355 }
1356 
ccw_device_set_disconnected(struct ccw_device * cdev)1357 void ccw_device_set_disconnected(struct ccw_device *cdev)
1358 {
1359 	if (!cdev)
1360 		return;
1361 	ccw_device_set_timeout(cdev, 0);
1362 	cdev->private->flags.fake_irb = 0;
1363 	cdev->private->state = DEV_STATE_DISCONNECTED;
1364 	if (cdev->online)
1365 		ccw_device_schedule_recovery();
1366 }
1367 
ccw_device_set_notoper(struct ccw_device * cdev)1368 void ccw_device_set_notoper(struct ccw_device *cdev)
1369 {
1370 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
1371 
1372 	CIO_TRACE_EVENT(2, "notoper");
1373 	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1374 	ccw_device_set_timeout(cdev, 0);
1375 	cio_disable_subchannel(sch);
1376 	cdev->private->state = DEV_STATE_NOT_OPER;
1377 }
1378 
1379 enum io_sch_action {
1380 	IO_SCH_UNREG,
1381 	IO_SCH_ORPH_UNREG,
1382 	IO_SCH_UNREG_CDEV,
1383 	IO_SCH_ATTACH,
1384 	IO_SCH_UNREG_ATTACH,
1385 	IO_SCH_ORPH_ATTACH,
1386 	IO_SCH_REPROBE,
1387 	IO_SCH_VERIFY,
1388 	IO_SCH_DISC,
1389 	IO_SCH_NOP,
1390 };
1391 
sch_get_action(struct subchannel * sch)1392 static enum io_sch_action sch_get_action(struct subchannel *sch)
1393 {
1394 	struct ccw_device *cdev;
1395 
1396 	cdev = sch_get_cdev(sch);
1397 	if (cio_update_schib(sch)) {
1398 		/* Not operational. */
1399 		if (!cdev)
1400 			return IO_SCH_UNREG;
1401 		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1402 			return IO_SCH_UNREG;
1403 		return IO_SCH_ORPH_UNREG;
1404 	}
1405 	/* Operational. */
1406 	if (!cdev)
1407 		return IO_SCH_ATTACH;
1408 	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1409 		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1410 			return IO_SCH_UNREG_ATTACH;
1411 		return IO_SCH_ORPH_ATTACH;
1412 	}
1413 	if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1414 		if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1415 			return IO_SCH_UNREG_CDEV;
1416 		return IO_SCH_DISC;
1417 	}
1418 	if (device_is_disconnected(cdev))
1419 		return IO_SCH_REPROBE;
1420 	if (cdev->online)
1421 		return IO_SCH_VERIFY;
1422 	if (cdev->private->state == DEV_STATE_NOT_OPER)
1423 		return IO_SCH_UNREG_ATTACH;
1424 	return IO_SCH_NOP;
1425 }
1426 
1427 /**
1428  * io_subchannel_sch_event - process subchannel event
1429  * @sch: subchannel
1430  * @process: non-zero if function is called in process context
1431  *
1432  * An unspecified event occurred for this subchannel. Adjust data according
1433  * to the current operational state of the subchannel and device. Return
1434  * zero when the event has been handled sufficiently or -EAGAIN when this
1435  * function should be called again in process context.
1436  */
io_subchannel_sch_event(struct subchannel * sch,int process)1437 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1438 {
1439 	unsigned long flags;
1440 	struct ccw_device *cdev;
1441 	struct ccw_dev_id dev_id;
1442 	enum io_sch_action action;
1443 	int rc = -EAGAIN;
1444 
1445 	spin_lock_irqsave(sch->lock, flags);
1446 	if (!device_is_registered(&sch->dev))
1447 		goto out_unlock;
1448 	if (work_pending(&sch->todo_work))
1449 		goto out_unlock;
1450 	cdev = sch_get_cdev(sch);
1451 	if (cdev && work_pending(&cdev->private->todo_work))
1452 		goto out_unlock;
1453 	action = sch_get_action(sch);
1454 	CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1455 		      sch->schid.ssid, sch->schid.sch_no, process,
1456 		      action);
1457 	/* Perform immediate actions while holding the lock. */
1458 	switch (action) {
1459 	case IO_SCH_REPROBE:
1460 		/* Trigger device recognition. */
1461 		ccw_device_trigger_reprobe(cdev);
1462 		rc = 0;
1463 		goto out_unlock;
1464 	case IO_SCH_VERIFY:
1465 		/* Trigger path verification. */
1466 		io_subchannel_verify(sch);
1467 		rc = 0;
1468 		goto out_unlock;
1469 	case IO_SCH_DISC:
1470 		ccw_device_set_disconnected(cdev);
1471 		rc = 0;
1472 		goto out_unlock;
1473 	case IO_SCH_ORPH_UNREG:
1474 	case IO_SCH_ORPH_ATTACH:
1475 		ccw_device_set_disconnected(cdev);
1476 		break;
1477 	case IO_SCH_UNREG_CDEV:
1478 	case IO_SCH_UNREG_ATTACH:
1479 	case IO_SCH_UNREG:
1480 		if (!cdev)
1481 			break;
1482 		if (cdev->private->state == DEV_STATE_SENSE_ID) {
1483 			/*
1484 			 * Note: delayed work triggered by this event
1485 			 * and repeated calls to sch_event are synchronized
1486 			 * by the above check for work_pending(cdev).
1487 			 */
1488 			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1489 		} else
1490 			ccw_device_set_notoper(cdev);
1491 		break;
1492 	case IO_SCH_NOP:
1493 		rc = 0;
1494 		goto out_unlock;
1495 	default:
1496 		break;
1497 	}
1498 	spin_unlock_irqrestore(sch->lock, flags);
1499 	/* All other actions require process context. */
1500 	if (!process)
1501 		goto out;
1502 	/* Handle attached ccw device. */
1503 	switch (action) {
1504 	case IO_SCH_ORPH_UNREG:
1505 	case IO_SCH_ORPH_ATTACH:
1506 		/* Move ccw device to orphanage. */
1507 		rc = ccw_device_move_to_orph(cdev);
1508 		if (rc)
1509 			goto out;
1510 		break;
1511 	case IO_SCH_UNREG_CDEV:
1512 	case IO_SCH_UNREG_ATTACH:
1513 		spin_lock_irqsave(sch->lock, flags);
1514 		sch_set_cdev(sch, NULL);
1515 		spin_unlock_irqrestore(sch->lock, flags);
1516 		/* Unregister ccw device. */
1517 		ccw_device_unregister(cdev);
1518 		break;
1519 	default:
1520 		break;
1521 	}
1522 	/* Handle subchannel. */
1523 	switch (action) {
1524 	case IO_SCH_ORPH_UNREG:
1525 	case IO_SCH_UNREG:
1526 		css_sch_device_unregister(sch);
1527 		break;
1528 	case IO_SCH_ORPH_ATTACH:
1529 	case IO_SCH_UNREG_ATTACH:
1530 	case IO_SCH_ATTACH:
1531 		dev_id.ssid = sch->schid.ssid;
1532 		dev_id.devno = sch->schib.pmcw.dev;
1533 		cdev = get_ccwdev_by_dev_id(&dev_id);
1534 		if (!cdev) {
1535 			sch_create_and_recog_new_device(sch);
1536 			break;
1537 		}
1538 		rc = ccw_device_move_to_sch(cdev, sch);
1539 		if (rc) {
1540 			/* Release reference from get_ccwdev_by_dev_id() */
1541 			put_device(&cdev->dev);
1542 			goto out;
1543 		}
1544 		spin_lock_irqsave(sch->lock, flags);
1545 		ccw_device_trigger_reprobe(cdev);
1546 		spin_unlock_irqrestore(sch->lock, flags);
1547 		/* Release reference from get_ccwdev_by_dev_id() */
1548 		put_device(&cdev->dev);
1549 		break;
1550 	default:
1551 		break;
1552 	}
1553 	return 0;
1554 
1555 out_unlock:
1556 	spin_unlock_irqrestore(sch->lock, flags);
1557 out:
1558 	return rc;
1559 }
1560 
ccw_device_set_int_class(struct ccw_device * cdev)1561 static void ccw_device_set_int_class(struct ccw_device *cdev)
1562 {
1563 	struct ccw_driver *cdrv = cdev->drv;
1564 
1565 	/* Note: we interpret class 0 in this context as an uninitialized
1566 	 * field since it translates to a non-I/O interrupt class. */
1567 	if (cdrv->int_class != 0)
1568 		cdev->private->int_class = cdrv->int_class;
1569 	else
1570 		cdev->private->int_class = IRQIO_CIO;
1571 }
1572 
1573 #ifdef CONFIG_CCW_CONSOLE
ccw_device_enable_console(struct ccw_device * cdev)1574 int __init ccw_device_enable_console(struct ccw_device *cdev)
1575 {
1576 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
1577 	int rc;
1578 
1579 	if (!cdev->drv || !cdev->handler)
1580 		return -EINVAL;
1581 
1582 	io_subchannel_init_fields(sch);
1583 	rc = cio_commit_config(sch);
1584 	if (rc)
1585 		return rc;
1586 	sch->driver = &io_subchannel_driver;
1587 	io_subchannel_recog(cdev, sch);
1588 	/* Now wait for the async. recognition to come to an end. */
1589 	spin_lock_irq(cdev->ccwlock);
1590 	while (!dev_fsm_final_state(cdev))
1591 		ccw_device_wait_idle(cdev);
1592 
1593 	/* Hold on to an extra reference while device is online. */
1594 	get_device(&cdev->dev);
1595 	rc = ccw_device_online(cdev);
1596 	if (rc)
1597 		goto out_unlock;
1598 
1599 	while (!dev_fsm_final_state(cdev))
1600 		ccw_device_wait_idle(cdev);
1601 
1602 	if (cdev->private->state == DEV_STATE_ONLINE)
1603 		cdev->online = 1;
1604 	else
1605 		rc = -EIO;
1606 out_unlock:
1607 	spin_unlock_irq(cdev->ccwlock);
1608 	if (rc) /* Give up online reference since onlining failed. */
1609 		put_device(&cdev->dev);
1610 	return rc;
1611 }
1612 
ccw_device_create_console(struct ccw_driver * drv)1613 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1614 {
1615 	struct io_subchannel_private *io_priv;
1616 	struct ccw_device *cdev;
1617 	struct subchannel *sch;
1618 
1619 	sch = cio_probe_console();
1620 	if (IS_ERR(sch))
1621 		return ERR_CAST(sch);
1622 
1623 	io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1624 	if (!io_priv)
1625 		goto err_priv;
1626 	io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1627 				sizeof(*io_priv->dma_area),
1628 				&io_priv->dma_area_dma, GFP_KERNEL);
1629 	if (!io_priv->dma_area)
1630 		goto err_dma_area;
1631 	set_io_private(sch, io_priv);
1632 	cdev = io_subchannel_create_ccwdev(sch);
1633 	if (IS_ERR(cdev)) {
1634 		dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1635 				  io_priv->dma_area, io_priv->dma_area_dma);
1636 		set_io_private(sch, NULL);
1637 		put_device(&sch->dev);
1638 		kfree(io_priv);
1639 		return cdev;
1640 	}
1641 	cdev->drv = drv;
1642 	ccw_device_set_int_class(cdev);
1643 	return cdev;
1644 
1645 err_dma_area:
1646 	kfree(io_priv);
1647 err_priv:
1648 	put_device(&sch->dev);
1649 	return ERR_PTR(-ENOMEM);
1650 }
1651 
ccw_device_destroy_console(struct ccw_device * cdev)1652 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1653 {
1654 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
1655 	struct io_subchannel_private *io_priv = to_io_private(sch);
1656 
1657 	set_io_private(sch, NULL);
1658 	dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1659 			  io_priv->dma_area, io_priv->dma_area_dma);
1660 	put_device(&sch->dev);
1661 	put_device(&cdev->dev);
1662 	kfree(io_priv);
1663 }
1664 
1665 /**
1666  * ccw_device_wait_idle() - busy wait for device to become idle
1667  * @cdev: ccw device
1668  *
1669  * Poll until activity control is zero, that is, no function or data
1670  * transfer is pending/active.
1671  * Called with device lock being held.
1672  */
ccw_device_wait_idle(struct ccw_device * cdev)1673 void ccw_device_wait_idle(struct ccw_device *cdev)
1674 {
1675 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
1676 
1677 	while (1) {
1678 		cio_tsch(sch);
1679 		if (sch->schib.scsw.cmd.actl == 0)
1680 			break;
1681 		udelay(100);
1682 	}
1683 }
1684 #endif
1685 
1686 /**
1687  * get_ccwdev_by_busid() - obtain device from a bus id
1688  * @cdrv: driver the device is owned by
1689  * @bus_id: bus id of the device to be searched
1690  *
1691  * This function searches all devices owned by @cdrv for a device with a bus
1692  * id matching @bus_id.
1693  * Returns:
1694  *  If a match is found, its reference count of the found device is increased
1695  *  and it is returned; else %NULL is returned.
1696  */
get_ccwdev_by_busid(struct ccw_driver * cdrv,const char * bus_id)1697 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1698 				       const char *bus_id)
1699 {
1700 	struct device *dev;
1701 
1702 	dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1703 
1704 	return dev ? to_ccwdev(dev) : NULL;
1705 }
1706 
1707 /************************** device driver handling ************************/
1708 
1709 /* This is the implementation of the ccw_driver class. The probe, remove
1710  * and release methods are initially very similar to the device_driver
1711  * implementations, with the difference that they have ccw_device
1712  * arguments.
1713  *
1714  * A ccw driver also contains the information that is needed for
1715  * device matching.
1716  */
1717 static int
ccw_device_probe(struct device * dev)1718 ccw_device_probe (struct device *dev)
1719 {
1720 	struct ccw_device *cdev = to_ccwdev(dev);
1721 	struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1722 	int ret;
1723 
1724 	cdev->drv = cdrv; /* to let the driver call _set_online */
1725 	ccw_device_set_int_class(cdev);
1726 	ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1727 	if (ret) {
1728 		cdev->drv = NULL;
1729 		cdev->private->int_class = IRQIO_CIO;
1730 		return ret;
1731 	}
1732 
1733 	return 0;
1734 }
1735 
ccw_device_remove(struct device * dev)1736 static void ccw_device_remove(struct device *dev)
1737 {
1738 	struct ccw_device *cdev = to_ccwdev(dev);
1739 	struct ccw_driver *cdrv = cdev->drv;
1740 	struct subchannel *sch;
1741 	int ret;
1742 
1743 	if (cdrv->remove)
1744 		cdrv->remove(cdev);
1745 
1746 	spin_lock_irq(cdev->ccwlock);
1747 	if (cdev->online) {
1748 		cdev->online = 0;
1749 		ret = ccw_device_offline(cdev);
1750 		spin_unlock_irq(cdev->ccwlock);
1751 		if (ret == 0)
1752 			wait_event(cdev->private->wait_q,
1753 				   dev_fsm_final_state(cdev));
1754 		else
1755 			CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1756 				      "device 0.%x.%04x\n",
1757 				      ret, cdev->private->dev_id.ssid,
1758 				      cdev->private->dev_id.devno);
1759 		/* Give up reference obtained in ccw_device_set_online(). */
1760 		put_device(&cdev->dev);
1761 		spin_lock_irq(cdev->ccwlock);
1762 	}
1763 	ccw_device_set_timeout(cdev, 0);
1764 	cdev->drv = NULL;
1765 	cdev->private->int_class = IRQIO_CIO;
1766 	sch = to_subchannel(cdev->dev.parent);
1767 	spin_unlock_irq(cdev->ccwlock);
1768 	io_subchannel_quiesce(sch);
1769 	__disable_cmf(cdev);
1770 }
1771 
ccw_device_shutdown(struct device * dev)1772 static void ccw_device_shutdown(struct device *dev)
1773 {
1774 	struct ccw_device *cdev;
1775 
1776 	cdev = to_ccwdev(dev);
1777 	if (cdev->drv && cdev->drv->shutdown)
1778 		cdev->drv->shutdown(cdev);
1779 	__disable_cmf(cdev);
1780 }
1781 
1782 static struct bus_type ccw_bus_type = {
1783 	.name   = "ccw",
1784 	.match  = ccw_bus_match,
1785 	.uevent = ccw_uevent,
1786 	.probe  = ccw_device_probe,
1787 	.remove = ccw_device_remove,
1788 	.shutdown = ccw_device_shutdown,
1789 };
1790 
1791 /**
1792  * ccw_driver_register() - register a ccw driver
1793  * @cdriver: driver to be registered
1794  *
1795  * This function is mainly a wrapper around driver_register().
1796  * Returns:
1797  *   %0 on success and a negative error value on failure.
1798  */
ccw_driver_register(struct ccw_driver * cdriver)1799 int ccw_driver_register(struct ccw_driver *cdriver)
1800 {
1801 	struct device_driver *drv = &cdriver->driver;
1802 
1803 	drv->bus = &ccw_bus_type;
1804 
1805 	return driver_register(drv);
1806 }
1807 
1808 /**
1809  * ccw_driver_unregister() - deregister a ccw driver
1810  * @cdriver: driver to be deregistered
1811  *
1812  * This function is mainly a wrapper around driver_unregister().
1813  */
ccw_driver_unregister(struct ccw_driver * cdriver)1814 void ccw_driver_unregister(struct ccw_driver *cdriver)
1815 {
1816 	driver_unregister(&cdriver->driver);
1817 }
1818 
ccw_device_todo(struct work_struct * work)1819 static void ccw_device_todo(struct work_struct *work)
1820 {
1821 	struct ccw_device_private *priv;
1822 	struct ccw_device *cdev;
1823 	struct subchannel *sch;
1824 	enum cdev_todo todo;
1825 
1826 	priv = container_of(work, struct ccw_device_private, todo_work);
1827 	cdev = priv->cdev;
1828 	sch = to_subchannel(cdev->dev.parent);
1829 	/* Find out todo. */
1830 	spin_lock_irq(cdev->ccwlock);
1831 	todo = priv->todo;
1832 	priv->todo = CDEV_TODO_NOTHING;
1833 	CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1834 		      priv->dev_id.ssid, priv->dev_id.devno, todo);
1835 	spin_unlock_irq(cdev->ccwlock);
1836 	/* Perform todo. */
1837 	switch (todo) {
1838 	case CDEV_TODO_ENABLE_CMF:
1839 		cmf_reenable(cdev);
1840 		break;
1841 	case CDEV_TODO_REBIND:
1842 		ccw_device_do_unbind_bind(cdev);
1843 		break;
1844 	case CDEV_TODO_REGISTER:
1845 		io_subchannel_register(cdev);
1846 		break;
1847 	case CDEV_TODO_UNREG_EVAL:
1848 		if (!sch_is_pseudo_sch(sch))
1849 			css_schedule_eval(sch->schid);
1850 		fallthrough;
1851 	case CDEV_TODO_UNREG:
1852 		spin_lock_irq(sch->lock);
1853 		sch_set_cdev(sch, NULL);
1854 		spin_unlock_irq(sch->lock);
1855 		ccw_device_unregister(cdev);
1856 		break;
1857 	default:
1858 		break;
1859 	}
1860 	/* Release workqueue ref. */
1861 	put_device(&cdev->dev);
1862 }
1863 
1864 /**
1865  * ccw_device_sched_todo - schedule ccw device operation
1866  * @cdev: ccw device
1867  * @todo: todo
1868  *
1869  * Schedule the operation identified by @todo to be performed on the slow path
1870  * workqueue. Do nothing if another operation with higher priority is already
1871  * scheduled. Needs to be called with ccwdev lock held.
1872  */
ccw_device_sched_todo(struct ccw_device * cdev,enum cdev_todo todo)1873 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
1874 {
1875 	CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
1876 		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
1877 		      todo);
1878 	if (cdev->private->todo >= todo)
1879 		return;
1880 	cdev->private->todo = todo;
1881 	/* Get workqueue ref. */
1882 	if (!get_device(&cdev->dev))
1883 		return;
1884 	if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
1885 		/* Already queued, release workqueue ref. */
1886 		put_device(&cdev->dev);
1887 	}
1888 }
1889 
1890 /**
1891  * ccw_device_siosl() - initiate logging
1892  * @cdev: ccw device
1893  *
1894  * This function is used to invoke model-dependent logging within the channel
1895  * subsystem.
1896  */
ccw_device_siosl(struct ccw_device * cdev)1897 int ccw_device_siosl(struct ccw_device *cdev)
1898 {
1899 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
1900 
1901 	return chsc_siosl(sch->schid);
1902 }
1903 EXPORT_SYMBOL_GPL(ccw_device_siosl);
1904 
1905 EXPORT_SYMBOL(ccw_device_set_online);
1906 EXPORT_SYMBOL(ccw_device_set_offline);
1907 EXPORT_SYMBOL(ccw_driver_register);
1908 EXPORT_SYMBOL(ccw_driver_unregister);
1909 EXPORT_SYMBOL(get_ccwdev_by_busid);
1910