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47/* Time after which channel-path status may be outdated.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