xref: /openbmc/linux/drivers/s390/cio/chp.c (revision 80483c3a)
1 /*
2  *    Copyright IBM Corp. 1999, 2010
3  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
4  *		 Arnd Bergmann (arndb@de.ibm.com)
5  *		 Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
6  */
7 
8 #include <linux/bug.h>
9 #include <linux/workqueue.h>
10 #include <linux/spinlock.h>
11 #include <linux/export.h>
12 #include <linux/sched.h>
13 #include <linux/init.h>
14 #include <linux/jiffies.h>
15 #include <linux/wait.h>
16 #include <linux/mutex.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <asm/chpid.h>
20 #include <asm/sclp.h>
21 #include <asm/crw.h>
22 
23 #include "cio.h"
24 #include "css.h"
25 #include "ioasm.h"
26 #include "cio_debug.h"
27 #include "chp.h"
28 
29 #define to_channelpath(device) container_of(device, struct channel_path, dev)
30 #define CHP_INFO_UPDATE_INTERVAL	1*HZ
31 
32 enum cfg_task_t {
33 	cfg_none,
34 	cfg_configure,
35 	cfg_deconfigure
36 };
37 
38 /* Map for pending configure tasks. */
39 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
40 static DEFINE_SPINLOCK(cfg_lock);
41 
42 /* Map for channel-path status. */
43 static struct sclp_chp_info chp_info;
44 static DEFINE_MUTEX(info_lock);
45 
46 /* Time after which channel-path status may be outdated. */
47 static unsigned long chp_info_expires;
48 
49 static struct work_struct cfg_work;
50 
51 /* Wait queue for configure completion events. */
52 static wait_queue_head_t cfg_wait_queue;
53 
54 /* Set vary state for given chpid. */
55 static void set_chp_logically_online(struct chp_id chpid, int onoff)
56 {
57 	chpid_to_chp(chpid)->state = onoff;
58 }
59 
60 /* On success return 0 if channel-path is varied offline, 1 if it is varied
61  * online. Return -ENODEV if channel-path is not registered. */
62 int chp_get_status(struct chp_id chpid)
63 {
64 	return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
65 }
66 
67 /**
68  * chp_get_sch_opm - return opm for subchannel
69  * @sch: subchannel
70  *
71  * Calculate and return the operational path mask (opm) based on the chpids
72  * used by the subchannel and the status of the associated channel-paths.
73  */
74 u8 chp_get_sch_opm(struct subchannel *sch)
75 {
76 	struct chp_id chpid;
77 	int opm;
78 	int i;
79 
80 	opm = 0;
81 	chp_id_init(&chpid);
82 	for (i = 0; i < 8; i++) {
83 		opm <<= 1;
84 		chpid.id = sch->schib.pmcw.chpid[i];
85 		if (chp_get_status(chpid) != 0)
86 			opm |= 1;
87 	}
88 	return opm;
89 }
90 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
91 
92 /**
93  * chp_is_registered - check if a channel-path is registered
94  * @chpid: channel-path ID
95  *
96  * Return non-zero if a channel-path with the given chpid is registered,
97  * zero otherwise.
98  */
99 int chp_is_registered(struct chp_id chpid)
100 {
101 	return chpid_to_chp(chpid) != NULL;
102 }
103 
104 /*
105  * Function: s390_vary_chpid
106  * Varies the specified chpid online or offline
107  */
108 static int s390_vary_chpid(struct chp_id chpid, int on)
109 {
110 	char dbf_text[15];
111 	int status;
112 
113 	sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
114 		chpid.id);
115 	CIO_TRACE_EVENT(2, dbf_text);
116 
117 	status = chp_get_status(chpid);
118 	if (!on && !status)
119 		return 0;
120 
121 	set_chp_logically_online(chpid, on);
122 	chsc_chp_vary(chpid, on);
123 	return 0;
124 }
125 
126 /*
127  * Channel measurement related functions
128  */
129 static ssize_t chp_measurement_chars_read(struct file *filp,
130 					  struct kobject *kobj,
131 					  struct bin_attribute *bin_attr,
132 					  char *buf, loff_t off, size_t count)
133 {
134 	struct channel_path *chp;
135 	struct device *device;
136 
137 	device = container_of(kobj, struct device, kobj);
138 	chp = to_channelpath(device);
139 	if (chp->cmg == -1)
140 		return 0;
141 
142 	return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
143 				       sizeof(chp->cmg_chars));
144 }
145 
146 static struct bin_attribute chp_measurement_chars_attr = {
147 	.attr = {
148 		.name = "measurement_chars",
149 		.mode = S_IRUSR,
150 	},
151 	.size = sizeof(struct cmg_chars),
152 	.read = chp_measurement_chars_read,
153 };
154 
155 static void chp_measurement_copy_block(struct cmg_entry *buf,
156 				       struct channel_subsystem *css,
157 				       struct chp_id chpid)
158 {
159 	void *area;
160 	struct cmg_entry *entry, reference_buf;
161 	int idx;
162 
163 	if (chpid.id < 128) {
164 		area = css->cub_addr1;
165 		idx = chpid.id;
166 	} else {
167 		area = css->cub_addr2;
168 		idx = chpid.id - 128;
169 	}
170 	entry = area + (idx * sizeof(struct cmg_entry));
171 	do {
172 		memcpy(buf, entry, sizeof(*entry));
173 		memcpy(&reference_buf, entry, sizeof(*entry));
174 	} while (reference_buf.values[0] != buf->values[0]);
175 }
176 
177 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
178 				    struct bin_attribute *bin_attr,
179 				    char *buf, loff_t off, size_t count)
180 {
181 	struct channel_path *chp;
182 	struct channel_subsystem *css;
183 	struct device *device;
184 	unsigned int size;
185 
186 	device = container_of(kobj, struct device, kobj);
187 	chp = to_channelpath(device);
188 	css = to_css(chp->dev.parent);
189 
190 	size = sizeof(struct cmg_entry);
191 
192 	/* Only allow single reads. */
193 	if (off || count < size)
194 		return 0;
195 	chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
196 	count = size;
197 	return count;
198 }
199 
200 static struct bin_attribute chp_measurement_attr = {
201 	.attr = {
202 		.name = "measurement",
203 		.mode = S_IRUSR,
204 	},
205 	.size = sizeof(struct cmg_entry),
206 	.read = chp_measurement_read,
207 };
208 
209 void chp_remove_cmg_attr(struct channel_path *chp)
210 {
211 	device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
212 	device_remove_bin_file(&chp->dev, &chp_measurement_attr);
213 }
214 
215 int chp_add_cmg_attr(struct channel_path *chp)
216 {
217 	int ret;
218 
219 	ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
220 	if (ret)
221 		return ret;
222 	ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
223 	if (ret)
224 		device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
225 	return ret;
226 }
227 
228 /*
229  * Files for the channel path entries.
230  */
231 static ssize_t chp_status_show(struct device *dev,
232 			       struct device_attribute *attr, char *buf)
233 {
234 	struct channel_path *chp = to_channelpath(dev);
235 	int status;
236 
237 	mutex_lock(&chp->lock);
238 	status = chp->state;
239 	mutex_unlock(&chp->lock);
240 
241 	return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
242 }
243 
244 static ssize_t chp_status_write(struct device *dev,
245 				struct device_attribute *attr,
246 				const char *buf, size_t count)
247 {
248 	struct channel_path *cp = to_channelpath(dev);
249 	char cmd[10];
250 	int num_args;
251 	int error;
252 
253 	num_args = sscanf(buf, "%5s", cmd);
254 	if (!num_args)
255 		return count;
256 
257 	if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
258 		mutex_lock(&cp->lock);
259 		error = s390_vary_chpid(cp->chpid, 1);
260 		mutex_unlock(&cp->lock);
261 	} else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
262 		mutex_lock(&cp->lock);
263 		error = s390_vary_chpid(cp->chpid, 0);
264 		mutex_unlock(&cp->lock);
265 	} else
266 		error = -EINVAL;
267 
268 	return error < 0 ? error : count;
269 }
270 
271 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
272 
273 static ssize_t chp_configure_show(struct device *dev,
274 				  struct device_attribute *attr, char *buf)
275 {
276 	struct channel_path *cp;
277 	int status;
278 
279 	cp = to_channelpath(dev);
280 	status = chp_info_get_status(cp->chpid);
281 	if (status < 0)
282 		return status;
283 
284 	return snprintf(buf, PAGE_SIZE, "%d\n", status);
285 }
286 
287 static int cfg_wait_idle(void);
288 
289 static ssize_t chp_configure_write(struct device *dev,
290 				   struct device_attribute *attr,
291 				   const char *buf, size_t count)
292 {
293 	struct channel_path *cp;
294 	int val;
295 	char delim;
296 
297 	if (sscanf(buf, "%d %c", &val, &delim) != 1)
298 		return -EINVAL;
299 	if (val != 0 && val != 1)
300 		return -EINVAL;
301 	cp = to_channelpath(dev);
302 	chp_cfg_schedule(cp->chpid, val);
303 	cfg_wait_idle();
304 
305 	return count;
306 }
307 
308 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
309 
310 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
311 			     char *buf)
312 {
313 	struct channel_path *chp = to_channelpath(dev);
314 	u8 type;
315 
316 	mutex_lock(&chp->lock);
317 	type = chp->desc.desc;
318 	mutex_unlock(&chp->lock);
319 	return sprintf(buf, "%x\n", type);
320 }
321 
322 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
323 
324 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
325 			    char *buf)
326 {
327 	struct channel_path *chp = to_channelpath(dev);
328 
329 	if (!chp)
330 		return 0;
331 	if (chp->cmg == -1) /* channel measurements not available */
332 		return sprintf(buf, "unknown\n");
333 	return sprintf(buf, "%x\n", chp->cmg);
334 }
335 
336 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
337 
338 static ssize_t chp_shared_show(struct device *dev,
339 			       struct device_attribute *attr, char *buf)
340 {
341 	struct channel_path *chp = to_channelpath(dev);
342 
343 	if (!chp)
344 		return 0;
345 	if (chp->shared == -1) /* channel measurements not available */
346 		return sprintf(buf, "unknown\n");
347 	return sprintf(buf, "%x\n", chp->shared);
348 }
349 
350 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
351 
352 static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
353 			     char *buf)
354 {
355 	struct channel_path *chp = to_channelpath(dev);
356 	ssize_t rc;
357 
358 	mutex_lock(&chp->lock);
359 	if (chp->desc_fmt1.flags & 0x10)
360 		rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid);
361 	else
362 		rc = 0;
363 	mutex_unlock(&chp->lock);
364 
365 	return rc;
366 }
367 static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
368 
369 static ssize_t chp_chid_external_show(struct device *dev,
370 				      struct device_attribute *attr, char *buf)
371 {
372 	struct channel_path *chp = to_channelpath(dev);
373 	ssize_t rc;
374 
375 	mutex_lock(&chp->lock);
376 	if (chp->desc_fmt1.flags & 0x10)
377 		rc = sprintf(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
378 	else
379 		rc = 0;
380 	mutex_unlock(&chp->lock);
381 
382 	return rc;
383 }
384 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
385 
386 static struct attribute *chp_attrs[] = {
387 	&dev_attr_status.attr,
388 	&dev_attr_configure.attr,
389 	&dev_attr_type.attr,
390 	&dev_attr_cmg.attr,
391 	&dev_attr_shared.attr,
392 	&dev_attr_chid.attr,
393 	&dev_attr_chid_external.attr,
394 	NULL,
395 };
396 static struct attribute_group chp_attr_group = {
397 	.attrs = chp_attrs,
398 };
399 static const struct attribute_group *chp_attr_groups[] = {
400 	&chp_attr_group,
401 	NULL,
402 };
403 
404 static void chp_release(struct device *dev)
405 {
406 	struct channel_path *cp;
407 
408 	cp = to_channelpath(dev);
409 	kfree(cp);
410 }
411 
412 /**
413  * chp_update_desc - update channel-path description
414  * @chp - channel-path
415  *
416  * Update the channel-path description of the specified channel-path
417  * including channel measurement related information.
418  * Return zero on success, non-zero otherwise.
419  */
420 int chp_update_desc(struct channel_path *chp)
421 {
422 	int rc;
423 
424 	rc = chsc_determine_base_channel_path_desc(chp->chpid, &chp->desc);
425 	if (rc)
426 		return rc;
427 
428 	/*
429 	 * Fetching the following data is optional. Not all machines or
430 	 * hypervisors implement the required chsc commands.
431 	 */
432 	chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
433 	chsc_get_channel_measurement_chars(chp);
434 
435 	return 0;
436 }
437 
438 /**
439  * chp_new - register a new channel-path
440  * @chpid - channel-path ID
441  *
442  * Create and register data structure representing new channel-path. Return
443  * zero on success, non-zero otherwise.
444  */
445 int chp_new(struct chp_id chpid)
446 {
447 	struct channel_path *chp;
448 	int ret;
449 
450 	if (chp_is_registered(chpid))
451 		return 0;
452 	chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
453 	if (!chp)
454 		return -ENOMEM;
455 
456 	/* fill in status, etc. */
457 	chp->chpid = chpid;
458 	chp->state = 1;
459 	chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
460 	chp->dev.groups = chp_attr_groups;
461 	chp->dev.release = chp_release;
462 	mutex_init(&chp->lock);
463 
464 	/* Obtain channel path description and fill it in. */
465 	ret = chp_update_desc(chp);
466 	if (ret)
467 		goto out_free;
468 	if ((chp->desc.flags & 0x80) == 0) {
469 		ret = -ENODEV;
470 		goto out_free;
471 	}
472 	dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
473 
474 	/* make it known to the system */
475 	ret = device_register(&chp->dev);
476 	if (ret) {
477 		CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
478 			      chpid.cssid, chpid.id, ret);
479 		put_device(&chp->dev);
480 		goto out;
481 	}
482 	mutex_lock(&channel_subsystems[chpid.cssid]->mutex);
483 	if (channel_subsystems[chpid.cssid]->cm_enabled) {
484 		ret = chp_add_cmg_attr(chp);
485 		if (ret) {
486 			device_unregister(&chp->dev);
487 			mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
488 			goto out;
489 		}
490 	}
491 	channel_subsystems[chpid.cssid]->chps[chpid.id] = chp;
492 	mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
493 	goto out;
494 out_free:
495 	kfree(chp);
496 out:
497 	return ret;
498 }
499 
500 /**
501  * chp_get_chp_desc - return newly allocated channel-path description
502  * @chpid: channel-path ID
503  *
504  * On success return a newly allocated copy of the channel-path description
505  * data associated with the given channel-path ID. Return %NULL on error.
506  */
507 struct channel_path_desc *chp_get_chp_desc(struct chp_id chpid)
508 {
509 	struct channel_path *chp;
510 	struct channel_path_desc *desc;
511 
512 	chp = chpid_to_chp(chpid);
513 	if (!chp)
514 		return NULL;
515 	desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
516 	if (!desc)
517 		return NULL;
518 
519 	mutex_lock(&chp->lock);
520 	memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
521 	mutex_unlock(&chp->lock);
522 	return desc;
523 }
524 
525 /**
526  * chp_process_crw - process channel-path status change
527  * @crw0: channel report-word to handler
528  * @crw1: second channel-report word (always NULL)
529  * @overflow: crw overflow indication
530  *
531  * Handle channel-report-words indicating that the status of a channel-path
532  * has changed.
533  */
534 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
535 			    int overflow)
536 {
537 	struct chp_id chpid;
538 
539 	if (overflow) {
540 		css_schedule_eval_all();
541 		return;
542 	}
543 	CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
544 		      "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
545 		      crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
546 		      crw0->erc, crw0->rsid);
547 	/*
548 	 * Check for solicited machine checks. These are
549 	 * created by reset channel path and need not be
550 	 * handled here.
551 	 */
552 	if (crw0->slct) {
553 		CIO_CRW_EVENT(2, "solicited machine check for "
554 			      "channel path %02X\n", crw0->rsid);
555 		return;
556 	}
557 	chp_id_init(&chpid);
558 	chpid.id = crw0->rsid;
559 	switch (crw0->erc) {
560 	case CRW_ERC_IPARM: /* Path has come. */
561 		if (!chp_is_registered(chpid))
562 			chp_new(chpid);
563 		chsc_chp_online(chpid);
564 		break;
565 	case CRW_ERC_PERRI: /* Path has gone. */
566 	case CRW_ERC_PERRN:
567 		chsc_chp_offline(chpid);
568 		break;
569 	default:
570 		CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
571 			      crw0->erc);
572 	}
573 }
574 
575 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
576 {
577 	int i;
578 	int mask;
579 
580 	for (i = 0; i < 8; i++) {
581 		mask = 0x80 >> i;
582 		if (!(ssd->path_mask & mask))
583 			continue;
584 		if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
585 			continue;
586 		if ((ssd->fla_valid_mask & mask) &&
587 		    ((ssd->fla[i] & link->fla_mask) != link->fla))
588 			continue;
589 		return mask;
590 	}
591 	return 0;
592 }
593 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
594 
595 static inline int info_bit_num(struct chp_id id)
596 {
597 	return id.id + id.cssid * (__MAX_CHPID + 1);
598 }
599 
600 /* Force chp_info refresh on next call to info_validate(). */
601 static void info_expire(void)
602 {
603 	mutex_lock(&info_lock);
604 	chp_info_expires = jiffies - 1;
605 	mutex_unlock(&info_lock);
606 }
607 
608 /* Ensure that chp_info is up-to-date. */
609 static int info_update(void)
610 {
611 	int rc;
612 
613 	mutex_lock(&info_lock);
614 	rc = 0;
615 	if (time_after(jiffies, chp_info_expires)) {
616 		/* Data is too old, update. */
617 		rc = sclp_chp_read_info(&chp_info);
618 		chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
619 	}
620 	mutex_unlock(&info_lock);
621 
622 	return rc;
623 }
624 
625 /**
626  * chp_info_get_status - retrieve configure status of a channel-path
627  * @chpid: channel-path ID
628  *
629  * On success, return 0 for standby, 1 for configured, 2 for reserved,
630  * 3 for not recognized. Return negative error code on error.
631  */
632 int chp_info_get_status(struct chp_id chpid)
633 {
634 	int rc;
635 	int bit;
636 
637 	rc = info_update();
638 	if (rc)
639 		return rc;
640 
641 	bit = info_bit_num(chpid);
642 	mutex_lock(&info_lock);
643 	if (!chp_test_bit(chp_info.recognized, bit))
644 		rc = CHP_STATUS_NOT_RECOGNIZED;
645 	else if (chp_test_bit(chp_info.configured, bit))
646 		rc = CHP_STATUS_CONFIGURED;
647 	else if (chp_test_bit(chp_info.standby, bit))
648 		rc = CHP_STATUS_STANDBY;
649 	else
650 		rc = CHP_STATUS_RESERVED;
651 	mutex_unlock(&info_lock);
652 
653 	return rc;
654 }
655 
656 /* Return configure task for chpid. */
657 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
658 {
659 	return chp_cfg_task[chpid.cssid][chpid.id];
660 }
661 
662 /* Set configure task for chpid. */
663 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
664 {
665 	chp_cfg_task[chpid.cssid][chpid.id] = cfg;
666 }
667 
668 /* Fetch the first configure task. Set chpid accordingly. */
669 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
670 {
671 	enum cfg_task_t t = cfg_none;
672 
673 	chp_id_for_each(chpid) {
674 		t = cfg_get_task(*chpid);
675 		if (t != cfg_none)
676 			break;
677 	}
678 
679 	return t;
680 }
681 
682 /* Perform one configure/deconfigure request. Reschedule work function until
683  * last request. */
684 static void cfg_func(struct work_struct *work)
685 {
686 	struct chp_id chpid;
687 	enum cfg_task_t t;
688 	int rc;
689 
690 	spin_lock(&cfg_lock);
691 	t = chp_cfg_fetch_task(&chpid);
692 	spin_unlock(&cfg_lock);
693 
694 	switch (t) {
695 	case cfg_configure:
696 		rc = sclp_chp_configure(chpid);
697 		if (rc)
698 			CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
699 				      "%d\n", chpid.cssid, chpid.id, rc);
700 		else {
701 			info_expire();
702 			chsc_chp_online(chpid);
703 		}
704 		break;
705 	case cfg_deconfigure:
706 		rc = sclp_chp_deconfigure(chpid);
707 		if (rc)
708 			CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
709 				      "%d\n", chpid.cssid, chpid.id, rc);
710 		else {
711 			info_expire();
712 			chsc_chp_offline(chpid);
713 		}
714 		break;
715 	case cfg_none:
716 		/* Get updated information after last change. */
717 		info_update();
718 		wake_up_interruptible(&cfg_wait_queue);
719 		return;
720 	}
721 	spin_lock(&cfg_lock);
722 	if (t == cfg_get_task(chpid))
723 		cfg_set_task(chpid, cfg_none);
724 	spin_unlock(&cfg_lock);
725 	schedule_work(&cfg_work);
726 }
727 
728 /**
729  * chp_cfg_schedule - schedule chpid configuration request
730  * @chpid - channel-path ID
731  * @configure - Non-zero for configure, zero for deconfigure
732  *
733  * Schedule a channel-path configuration/deconfiguration request.
734  */
735 void chp_cfg_schedule(struct chp_id chpid, int configure)
736 {
737 	CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
738 		      configure);
739 	spin_lock(&cfg_lock);
740 	cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
741 	spin_unlock(&cfg_lock);
742 	schedule_work(&cfg_work);
743 }
744 
745 /**
746  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
747  * @chpid - channel-path ID
748  *
749  * Cancel an active channel-path deconfiguration request if it has not yet
750  * been performed.
751  */
752 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
753 {
754 	CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
755 	spin_lock(&cfg_lock);
756 	if (cfg_get_task(chpid) == cfg_deconfigure)
757 		cfg_set_task(chpid, cfg_none);
758 	spin_unlock(&cfg_lock);
759 }
760 
761 static bool cfg_idle(void)
762 {
763 	struct chp_id chpid;
764 	enum cfg_task_t t;
765 
766 	spin_lock(&cfg_lock);
767 	t = chp_cfg_fetch_task(&chpid);
768 	spin_unlock(&cfg_lock);
769 
770 	return t == cfg_none;
771 }
772 
773 static int cfg_wait_idle(void)
774 {
775 	if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
776 		return -ERESTARTSYS;
777 	return 0;
778 }
779 
780 static int __init chp_init(void)
781 {
782 	struct chp_id chpid;
783 	int ret;
784 
785 	ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
786 	if (ret)
787 		return ret;
788 	INIT_WORK(&cfg_work, cfg_func);
789 	init_waitqueue_head(&cfg_wait_queue);
790 	if (info_update())
791 		return 0;
792 	/* Register available channel-paths. */
793 	chp_id_for_each(&chpid) {
794 		if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
795 			chp_new(chpid);
796 	}
797 
798 	return 0;
799 }
800 
801 subsys_initcall(chp_init);
802