xref: /linux/drivers/s390/cio/chp.c (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    Copyright IBM Corp. 1999, 2010
4  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
5  *		 Arnd Bergmann (arndb@de.ibm.com)
6  *		 Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
7  */
8 
9 #include <linux/bug.h>
10 #include <linux/workqueue.h>
11 #include <linux/spinlock.h>
12 #include <linux/export.h>
13 #include <linux/sched.h>
14 #include <linux/init.h>
15 #include <linux/jiffies.h>
16 #include <linux/wait.h>
17 #include <linux/mutex.h>
18 #include <linux/errno.h>
19 #include <linux/slab.h>
20 #include <asm/chpid.h>
21 #include <asm/sclp.h>
22 #include <asm/crw.h>
23 
24 #include "cio.h"
25 #include "css.h"
26 #include "ioasm.h"
27 #include "cio_debug.h"
28 #include "chp.h"
29 
30 #define to_channelpath(device) container_of(device, struct channel_path, dev)
31 #define CHP_INFO_UPDATE_INTERVAL	1*HZ
32 
33 enum cfg_task_t {
34 	cfg_none,
35 	cfg_configure,
36 	cfg_deconfigure
37 };
38 
39 /* Map for pending configure tasks. */
40 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
41 static DEFINE_SPINLOCK(cfg_lock);
42 
43 /* Map for channel-path status. */
44 static struct sclp_chp_info chp_info;
45 static DEFINE_MUTEX(info_lock);
46 
47 /* Time after which channel-path status may be outdated. */
48 static unsigned long chp_info_expires;
49 
50 static struct work_struct cfg_work;
51 
52 /* Wait queue for configure completion events. */
53 static DECLARE_WAIT_QUEUE_HEAD(cfg_wait_queue);
54 
55 /* Set vary state for given chpid. */
56 static void set_chp_logically_online(struct chp_id chpid, int onoff)
57 {
58 	chpid_to_chp(chpid)->state = onoff;
59 }
60 
61 /* On success return 0 if channel-path is varied offline, 1 if it is varied
62  * online. Return -ENODEV if channel-path is not registered. */
63 int chp_get_status(struct chp_id chpid)
64 {
65 	return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
66 }
67 
68 /**
69  * chp_get_sch_opm - return opm for subchannel
70  * @sch: subchannel
71  *
72  * Calculate and return the operational path mask (opm) based on the chpids
73  * used by the subchannel and the status of the associated channel-paths.
74  */
75 u8 chp_get_sch_opm(struct subchannel *sch)
76 {
77 	struct chp_id chpid;
78 	int opm;
79 	int i;
80 
81 	opm = 0;
82 	chp_id_init(&chpid);
83 	for (i = 0; i < 8; i++) {
84 		opm <<= 1;
85 		chpid.id = sch->schib.pmcw.chpid[i];
86 		if (chp_get_status(chpid) != 0)
87 			opm |= 1;
88 	}
89 	return opm;
90 }
91 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
92 
93 /**
94  * chp_is_registered - check if a channel-path is registered
95  * @chpid: channel-path ID
96  *
97  * Return non-zero if a channel-path with the given chpid is registered,
98  * zero otherwise.
99  */
100 int chp_is_registered(struct chp_id chpid)
101 {
102 	return chpid_to_chp(chpid) != NULL;
103 }
104 
105 /*
106  * Function: s390_vary_chpid
107  * Varies the specified chpid online or offline
108  */
109 static int s390_vary_chpid(struct chp_id chpid, int on)
110 {
111 	char dbf_text[15];
112 	int status;
113 
114 	sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
115 		chpid.id);
116 	CIO_TRACE_EVENT(2, dbf_text);
117 
118 	status = chp_get_status(chpid);
119 	if (!on && !status)
120 		return 0;
121 
122 	set_chp_logically_online(chpid, on);
123 	chsc_chp_vary(chpid, on);
124 	return 0;
125 }
126 
127 /*
128  * Channel measurement related functions
129  */
130 static ssize_t chp_measurement_chars_read(struct file *filp,
131 					  struct kobject *kobj,
132 					  struct bin_attribute *bin_attr,
133 					  char *buf, loff_t off, size_t count)
134 {
135 	struct channel_path *chp;
136 	struct device *device;
137 
138 	device = kobj_to_dev(kobj);
139 	chp = to_channelpath(device);
140 	if (chp->cmg == -1)
141 		return 0;
142 
143 	return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
144 				       sizeof(chp->cmg_chars));
145 }
146 
147 static const struct bin_attribute chp_measurement_chars_attr = {
148 	.attr = {
149 		.name = "measurement_chars",
150 		.mode = S_IRUSR,
151 	},
152 	.size = sizeof(struct cmg_chars),
153 	.read = chp_measurement_chars_read,
154 };
155 
156 static void chp_measurement_copy_block(struct cmg_entry *buf,
157 				       struct channel_subsystem *css,
158 				       struct chp_id chpid)
159 {
160 	void *area;
161 	struct cmg_entry *entry, reference_buf;
162 	int idx;
163 
164 	if (chpid.id < 128) {
165 		area = css->cub_addr1;
166 		idx = chpid.id;
167 	} else {
168 		area = css->cub_addr2;
169 		idx = chpid.id - 128;
170 	}
171 	entry = area + (idx * sizeof(struct cmg_entry));
172 	do {
173 		memcpy(buf, entry, sizeof(*entry));
174 		memcpy(&reference_buf, entry, sizeof(*entry));
175 	} while (reference_buf.values[0] != buf->values[0]);
176 }
177 
178 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
179 				    struct bin_attribute *bin_attr,
180 				    char *buf, loff_t off, size_t count)
181 {
182 	struct channel_path *chp;
183 	struct channel_subsystem *css;
184 	struct device *device;
185 	unsigned int size;
186 
187 	device = kobj_to_dev(kobj);
188 	chp = to_channelpath(device);
189 	css = to_css(chp->dev.parent);
190 
191 	size = sizeof(struct cmg_entry);
192 
193 	/* Only allow single reads. */
194 	if (off || count < size)
195 		return 0;
196 	chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
197 	count = size;
198 	return count;
199 }
200 
201 static const struct bin_attribute chp_measurement_attr = {
202 	.attr = {
203 		.name = "measurement",
204 		.mode = S_IRUSR,
205 	},
206 	.size = sizeof(struct cmg_entry),
207 	.read = chp_measurement_read,
208 };
209 
210 void chp_remove_cmg_attr(struct channel_path *chp)
211 {
212 	device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
213 	device_remove_bin_file(&chp->dev, &chp_measurement_attr);
214 }
215 
216 int chp_add_cmg_attr(struct channel_path *chp)
217 {
218 	int ret;
219 
220 	ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
221 	if (ret)
222 		return ret;
223 	ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
224 	if (ret)
225 		device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
226 	return ret;
227 }
228 
229 /*
230  * Files for the channel path entries.
231  */
232 static ssize_t chp_status_show(struct device *dev,
233 			       struct device_attribute *attr, char *buf)
234 {
235 	struct channel_path *chp = to_channelpath(dev);
236 	int status;
237 
238 	mutex_lock(&chp->lock);
239 	status = chp->state;
240 	mutex_unlock(&chp->lock);
241 
242 	return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
243 }
244 
245 static ssize_t chp_status_write(struct device *dev,
246 				struct device_attribute *attr,
247 				const char *buf, size_t count)
248 {
249 	struct channel_path *cp = to_channelpath(dev);
250 	char cmd[10];
251 	int num_args;
252 	int error;
253 
254 	num_args = sscanf(buf, "%5s", cmd);
255 	if (!num_args)
256 		return count;
257 
258 	/* Wait until previous actions have settled. */
259 	css_wait_for_slow_path();
260 
261 	if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
262 		mutex_lock(&cp->lock);
263 		error = s390_vary_chpid(cp->chpid, 1);
264 		mutex_unlock(&cp->lock);
265 	} else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
266 		mutex_lock(&cp->lock);
267 		error = s390_vary_chpid(cp->chpid, 0);
268 		mutex_unlock(&cp->lock);
269 	} else
270 		error = -EINVAL;
271 
272 	return error < 0 ? error : count;
273 }
274 
275 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
276 
277 static ssize_t chp_configure_show(struct device *dev,
278 				  struct device_attribute *attr, char *buf)
279 {
280 	struct channel_path *cp;
281 	int status;
282 
283 	cp = to_channelpath(dev);
284 	status = chp_info_get_status(cp->chpid);
285 	if (status < 0)
286 		return status;
287 
288 	return sysfs_emit(buf, "%d\n", status);
289 }
290 
291 static int cfg_wait_idle(void);
292 
293 static ssize_t chp_configure_write(struct device *dev,
294 				   struct device_attribute *attr,
295 				   const char *buf, size_t count)
296 {
297 	struct channel_path *cp;
298 	int val;
299 	char delim;
300 
301 	if (sscanf(buf, "%d %c", &val, &delim) != 1)
302 		return -EINVAL;
303 	if (val != 0 && val != 1)
304 		return -EINVAL;
305 	cp = to_channelpath(dev);
306 	chp_cfg_schedule(cp->chpid, val);
307 	cfg_wait_idle();
308 
309 	return count;
310 }
311 
312 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
313 
314 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
315 			     char *buf)
316 {
317 	struct channel_path *chp = to_channelpath(dev);
318 	u8 type;
319 
320 	mutex_lock(&chp->lock);
321 	type = chp->desc.desc;
322 	mutex_unlock(&chp->lock);
323 	return sprintf(buf, "%x\n", type);
324 }
325 
326 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
327 
328 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
329 			    char *buf)
330 {
331 	struct channel_path *chp = to_channelpath(dev);
332 
333 	if (!chp)
334 		return 0;
335 	if (chp->cmg == -1) /* channel measurements not available */
336 		return sprintf(buf, "unknown\n");
337 	return sprintf(buf, "%x\n", chp->cmg);
338 }
339 
340 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
341 
342 static ssize_t chp_shared_show(struct device *dev,
343 			       struct device_attribute *attr, char *buf)
344 {
345 	struct channel_path *chp = to_channelpath(dev);
346 
347 	if (!chp)
348 		return 0;
349 	if (chp->shared == -1) /* channel measurements not available */
350 		return sprintf(buf, "unknown\n");
351 	return sprintf(buf, "%x\n", chp->shared);
352 }
353 
354 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
355 
356 static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
357 			     char *buf)
358 {
359 	struct channel_path *chp = to_channelpath(dev);
360 	ssize_t rc;
361 
362 	mutex_lock(&chp->lock);
363 	if (chp->desc_fmt1.flags & 0x10)
364 		rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid);
365 	else
366 		rc = 0;
367 	mutex_unlock(&chp->lock);
368 
369 	return rc;
370 }
371 static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
372 
373 static ssize_t chp_chid_external_show(struct device *dev,
374 				      struct device_attribute *attr, char *buf)
375 {
376 	struct channel_path *chp = to_channelpath(dev);
377 	ssize_t rc;
378 
379 	mutex_lock(&chp->lock);
380 	if (chp->desc_fmt1.flags & 0x10)
381 		rc = sprintf(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
382 	else
383 		rc = 0;
384 	mutex_unlock(&chp->lock);
385 
386 	return rc;
387 }
388 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
389 
390 static ssize_t chp_esc_show(struct device *dev,
391 			    struct device_attribute *attr, char *buf)
392 {
393 	struct channel_path *chp = to_channelpath(dev);
394 	ssize_t rc;
395 
396 	mutex_lock(&chp->lock);
397 	rc = sprintf(buf, "%x\n", chp->desc_fmt1.esc);
398 	mutex_unlock(&chp->lock);
399 
400 	return rc;
401 }
402 static DEVICE_ATTR(esc, 0444, chp_esc_show, NULL);
403 
404 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
405 				struct bin_attribute *attr, char *buf,
406 				loff_t off, size_t count)
407 {
408 	struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
409 	ssize_t rc;
410 
411 	mutex_lock(&chp->lock);
412 	rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
413 				     sizeof(chp->desc_fmt3.util_str));
414 	mutex_unlock(&chp->lock);
415 
416 	return rc;
417 }
418 static BIN_ATTR_RO(util_string,
419 		   sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
420 
421 static struct bin_attribute *chp_bin_attrs[] = {
422 	&bin_attr_util_string,
423 	NULL,
424 };
425 
426 static struct attribute *chp_attrs[] = {
427 	&dev_attr_status.attr,
428 	&dev_attr_configure.attr,
429 	&dev_attr_type.attr,
430 	&dev_attr_cmg.attr,
431 	&dev_attr_shared.attr,
432 	&dev_attr_chid.attr,
433 	&dev_attr_chid_external.attr,
434 	&dev_attr_esc.attr,
435 	NULL,
436 };
437 static struct attribute_group chp_attr_group = {
438 	.attrs = chp_attrs,
439 	.bin_attrs = chp_bin_attrs,
440 };
441 static const struct attribute_group *chp_attr_groups[] = {
442 	&chp_attr_group,
443 	NULL,
444 };
445 
446 static void chp_release(struct device *dev)
447 {
448 	struct channel_path *cp;
449 
450 	cp = to_channelpath(dev);
451 	kfree(cp);
452 }
453 
454 /**
455  * chp_update_desc - update channel-path description
456  * @chp: channel-path
457  *
458  * Update the channel-path description of the specified channel-path
459  * including channel measurement related information.
460  * Return zero on success, non-zero otherwise.
461  */
462 int chp_update_desc(struct channel_path *chp)
463 {
464 	int rc;
465 
466 	rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc);
467 	if (rc)
468 		return rc;
469 
470 	/*
471 	 * Fetching the following data is optional. Not all machines or
472 	 * hypervisors implement the required chsc commands.
473 	 */
474 	chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
475 	chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3);
476 	chsc_get_channel_measurement_chars(chp);
477 
478 	return 0;
479 }
480 
481 /**
482  * chp_new - register a new channel-path
483  * @chpid: channel-path ID
484  *
485  * Create and register data structure representing new channel-path. Return
486  * zero on success, non-zero otherwise.
487  */
488 int chp_new(struct chp_id chpid)
489 {
490 	struct channel_subsystem *css = css_by_id(chpid.cssid);
491 	struct channel_path *chp;
492 	int ret = 0;
493 
494 	mutex_lock(&css->mutex);
495 	if (chp_is_registered(chpid))
496 		goto out;
497 
498 	chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
499 	if (!chp) {
500 		ret = -ENOMEM;
501 		goto out;
502 	}
503 	/* fill in status, etc. */
504 	chp->chpid = chpid;
505 	chp->state = 1;
506 	chp->dev.parent = &css->device;
507 	chp->dev.groups = chp_attr_groups;
508 	chp->dev.release = chp_release;
509 	mutex_init(&chp->lock);
510 
511 	/* Obtain channel path description and fill it in. */
512 	ret = chp_update_desc(chp);
513 	if (ret)
514 		goto out_free;
515 	if ((chp->desc.flags & 0x80) == 0) {
516 		ret = -ENODEV;
517 		goto out_free;
518 	}
519 	dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
520 
521 	/* make it known to the system */
522 	ret = device_register(&chp->dev);
523 	if (ret) {
524 		CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
525 			      chpid.cssid, chpid.id, ret);
526 		put_device(&chp->dev);
527 		goto out;
528 	}
529 
530 	if (css->cm_enabled) {
531 		ret = chp_add_cmg_attr(chp);
532 		if (ret) {
533 			device_unregister(&chp->dev);
534 			goto out;
535 		}
536 	}
537 	css->chps[chpid.id] = chp;
538 	goto out;
539 out_free:
540 	kfree(chp);
541 out:
542 	mutex_unlock(&css->mutex);
543 	return ret;
544 }
545 
546 /**
547  * chp_get_chp_desc - return newly allocated channel-path description
548  * @chpid: channel-path ID
549  *
550  * On success return a newly allocated copy of the channel-path description
551  * data associated with the given channel-path ID. Return %NULL on error.
552  */
553 struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid)
554 {
555 	struct channel_path *chp;
556 	struct channel_path_desc_fmt0 *desc;
557 
558 	chp = chpid_to_chp(chpid);
559 	if (!chp)
560 		return NULL;
561 	desc = kmalloc(sizeof(*desc), GFP_KERNEL);
562 	if (!desc)
563 		return NULL;
564 
565 	mutex_lock(&chp->lock);
566 	memcpy(desc, &chp->desc, sizeof(*desc));
567 	mutex_unlock(&chp->lock);
568 	return desc;
569 }
570 
571 /**
572  * chp_process_crw - process channel-path status change
573  * @crw0: channel report-word to handler
574  * @crw1: second channel-report word (always NULL)
575  * @overflow: crw overflow indication
576  *
577  * Handle channel-report-words indicating that the status of a channel-path
578  * has changed.
579  */
580 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
581 			    int overflow)
582 {
583 	struct chp_id chpid;
584 
585 	if (overflow) {
586 		css_schedule_eval_all();
587 		return;
588 	}
589 	CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
590 		      "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
591 		      crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
592 		      crw0->erc, crw0->rsid);
593 	/*
594 	 * Check for solicited machine checks. These are
595 	 * created by reset channel path and need not be
596 	 * handled here.
597 	 */
598 	if (crw0->slct) {
599 		CIO_CRW_EVENT(2, "solicited machine check for "
600 			      "channel path %02X\n", crw0->rsid);
601 		return;
602 	}
603 	chp_id_init(&chpid);
604 	chpid.id = crw0->rsid;
605 	switch (crw0->erc) {
606 	case CRW_ERC_IPARM: /* Path has come. */
607 	case CRW_ERC_INIT:
608 		chp_new(chpid);
609 		chsc_chp_online(chpid);
610 		break;
611 	case CRW_ERC_PERRI: /* Path has gone. */
612 	case CRW_ERC_PERRN:
613 		chsc_chp_offline(chpid);
614 		break;
615 	default:
616 		CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
617 			      crw0->erc);
618 	}
619 }
620 
621 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
622 {
623 	int i;
624 	int mask;
625 
626 	for (i = 0; i < 8; i++) {
627 		mask = 0x80 >> i;
628 		if (!(ssd->path_mask & mask))
629 			continue;
630 		if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
631 			continue;
632 		if ((ssd->fla_valid_mask & mask) &&
633 		    ((ssd->fla[i] & link->fla_mask) != link->fla))
634 			continue;
635 		return mask;
636 	}
637 	return 0;
638 }
639 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
640 
641 static inline int info_bit_num(struct chp_id id)
642 {
643 	return id.id + id.cssid * (__MAX_CHPID + 1);
644 }
645 
646 /* Force chp_info refresh on next call to info_validate(). */
647 static void info_expire(void)
648 {
649 	mutex_lock(&info_lock);
650 	chp_info_expires = jiffies - 1;
651 	mutex_unlock(&info_lock);
652 }
653 
654 /* Ensure that chp_info is up-to-date. */
655 static int info_update(void)
656 {
657 	int rc;
658 
659 	mutex_lock(&info_lock);
660 	rc = 0;
661 	if (time_after(jiffies, chp_info_expires)) {
662 		/* Data is too old, update. */
663 		rc = sclp_chp_read_info(&chp_info);
664 		chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
665 	}
666 	mutex_unlock(&info_lock);
667 
668 	return rc;
669 }
670 
671 /**
672  * chp_info_get_status - retrieve configure status of a channel-path
673  * @chpid: channel-path ID
674  *
675  * On success, return 0 for standby, 1 for configured, 2 for reserved,
676  * 3 for not recognized. Return negative error code on error.
677  */
678 int chp_info_get_status(struct chp_id chpid)
679 {
680 	int rc;
681 	int bit;
682 
683 	rc = info_update();
684 	if (rc)
685 		return rc;
686 
687 	bit = info_bit_num(chpid);
688 	mutex_lock(&info_lock);
689 	if (!chp_test_bit(chp_info.recognized, bit))
690 		rc = CHP_STATUS_NOT_RECOGNIZED;
691 	else if (chp_test_bit(chp_info.configured, bit))
692 		rc = CHP_STATUS_CONFIGURED;
693 	else if (chp_test_bit(chp_info.standby, bit))
694 		rc = CHP_STATUS_STANDBY;
695 	else
696 		rc = CHP_STATUS_RESERVED;
697 	mutex_unlock(&info_lock);
698 
699 	return rc;
700 }
701 
702 /* Return configure task for chpid. */
703 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
704 {
705 	return chp_cfg_task[chpid.cssid][chpid.id];
706 }
707 
708 /* Set configure task for chpid. */
709 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
710 {
711 	chp_cfg_task[chpid.cssid][chpid.id] = cfg;
712 }
713 
714 /* Fetch the first configure task. Set chpid accordingly. */
715 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
716 {
717 	enum cfg_task_t t = cfg_none;
718 
719 	chp_id_for_each(chpid) {
720 		t = cfg_get_task(*chpid);
721 		if (t != cfg_none)
722 			break;
723 	}
724 
725 	return t;
726 }
727 
728 /* Perform one configure/deconfigure request. Reschedule work function until
729  * last request. */
730 static void cfg_func(struct work_struct *work)
731 {
732 	struct chp_id chpid;
733 	enum cfg_task_t t;
734 	int rc;
735 
736 	spin_lock(&cfg_lock);
737 	t = chp_cfg_fetch_task(&chpid);
738 	spin_unlock(&cfg_lock);
739 
740 	switch (t) {
741 	case cfg_configure:
742 		rc = sclp_chp_configure(chpid);
743 		if (rc)
744 			CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
745 				      "%d\n", chpid.cssid, chpid.id, rc);
746 		else {
747 			info_expire();
748 			chsc_chp_online(chpid);
749 		}
750 		break;
751 	case cfg_deconfigure:
752 		rc = sclp_chp_deconfigure(chpid);
753 		if (rc)
754 			CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
755 				      "%d\n", chpid.cssid, chpid.id, rc);
756 		else {
757 			info_expire();
758 			chsc_chp_offline(chpid);
759 		}
760 		break;
761 	case cfg_none:
762 		/* Get updated information after last change. */
763 		info_update();
764 		wake_up_interruptible(&cfg_wait_queue);
765 		return;
766 	}
767 	spin_lock(&cfg_lock);
768 	if (t == cfg_get_task(chpid))
769 		cfg_set_task(chpid, cfg_none);
770 	spin_unlock(&cfg_lock);
771 	schedule_work(&cfg_work);
772 }
773 
774 /**
775  * chp_cfg_schedule - schedule chpid configuration request
776  * @chpid: channel-path ID
777  * @configure: Non-zero for configure, zero for deconfigure
778  *
779  * Schedule a channel-path configuration/deconfiguration request.
780  */
781 void chp_cfg_schedule(struct chp_id chpid, int configure)
782 {
783 	CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
784 		      configure);
785 	spin_lock(&cfg_lock);
786 	cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
787 	spin_unlock(&cfg_lock);
788 	schedule_work(&cfg_work);
789 }
790 
791 /**
792  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
793  * @chpid: channel-path ID
794  *
795  * Cancel an active channel-path deconfiguration request if it has not yet
796  * been performed.
797  */
798 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
799 {
800 	CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
801 	spin_lock(&cfg_lock);
802 	if (cfg_get_task(chpid) == cfg_deconfigure)
803 		cfg_set_task(chpid, cfg_none);
804 	spin_unlock(&cfg_lock);
805 }
806 
807 static bool cfg_idle(void)
808 {
809 	struct chp_id chpid;
810 	enum cfg_task_t t;
811 
812 	spin_lock(&cfg_lock);
813 	t = chp_cfg_fetch_task(&chpid);
814 	spin_unlock(&cfg_lock);
815 
816 	return t == cfg_none;
817 }
818 
819 static int cfg_wait_idle(void)
820 {
821 	if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
822 		return -ERESTARTSYS;
823 	return 0;
824 }
825 
826 static int __init chp_init(void)
827 {
828 	struct chp_id chpid;
829 	int state, ret;
830 
831 	ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
832 	if (ret)
833 		return ret;
834 	INIT_WORK(&cfg_work, cfg_func);
835 	if (info_update())
836 		return 0;
837 	/* Register available channel-paths. */
838 	chp_id_for_each(&chpid) {
839 		state = chp_info_get_status(chpid);
840 		if (state == CHP_STATUS_CONFIGURED ||
841 		    state == CHP_STATUS_STANDBY)
842 			chp_new(chpid);
843 	}
844 
845 	return 0;
846 }
847 
848 subsys_initcall(chp_init);
849