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
 33enum cfg_task_t {
 34	cfg_none,
 35	cfg_configure,
 36	cfg_deconfigure
 37};
 38
 39/* Map for pending configure tasks. */
 40static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
 41static DEFINE_SPINLOCK(cfg_lock);
 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 47/* Time after which channel-path status may be outdated.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
 50static struct work_struct cfg_work;
 51
 52/* Wait queue for configure completion events. */
 53static wait_queue_head_t cfg_wait_queue;
 54
 55/* Set vary state for given chpid. */
 56static 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. */
 63int 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 */
 75u8 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}
 91EXPORT_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 */
100int 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 */
109static 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 */
130static 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
147static 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
156static 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
178static 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
201static 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
210void 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
216int 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 */
232static 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
245static 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	if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
259		mutex_lock(&cp->lock);
260		error = s390_vary_chpid(cp->chpid, 1);
261		mutex_unlock(&cp->lock);
262	} else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
263		mutex_lock(&cp->lock);
264		error = s390_vary_chpid(cp->chpid, 0);
265		mutex_unlock(&cp->lock);
266	} else
267		error = -EINVAL;
268
269	return error < 0 ? error : count;
270}
271
272static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
273
274static ssize_t chp_configure_show(struct device *dev,
275				  struct device_attribute *attr, char *buf)
276{
277	struct channel_path *cp;
278	int status;
279
280	cp = to_channelpath(dev);
281	status = chp_info_get_status(cp->chpid);
282	if (status < 0)
283		return status;
284
285	return snprintf(buf, PAGE_SIZE, "%d\n", status);
286}
287
288static int cfg_wait_idle(void);
289
290static ssize_t chp_configure_write(struct device *dev,
291				   struct device_attribute *attr,
292				   const char *buf, size_t count)
293{
294	struct channel_path *cp;
295	int val;
296	char delim;
297
298	if (sscanf(buf, "%d %c", &val, &delim) != 1)
299		return -EINVAL;
300	if (val != 0 && val != 1)
301		return -EINVAL;
302	cp = to_channelpath(dev);
303	chp_cfg_schedule(cp->chpid, val);
304	cfg_wait_idle();
305
306	return count;
307}
308
309static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
310
311static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
312			     char *buf)
313{
314	struct channel_path *chp = to_channelpath(dev);
315	u8 type;
316
317	mutex_lock(&chp->lock);
318	type = chp->desc.desc;
319	mutex_unlock(&chp->lock);
320	return sprintf(buf, "%x\n", type);
321}
322
323static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
324
325static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
326			    char *buf)
327{
328	struct channel_path *chp = to_channelpath(dev);
329
330	if (!chp)
331		return 0;
332	if (chp->cmg == -1) /* channel measurements not available */
333		return sprintf(buf, "unknown\n");
334	return sprintf(buf, "%x\n", chp->cmg);
335}
336
337static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
338
339static ssize_t chp_shared_show(struct device *dev,
340			       struct device_attribute *attr, char *buf)
341{
342	struct channel_path *chp = to_channelpath(dev);
343
344	if (!chp)
345		return 0;
346	if (chp->shared == -1) /* channel measurements not available */
347		return sprintf(buf, "unknown\n");
348	return sprintf(buf, "%x\n", chp->shared);
349}
350
351static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
352
353static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
354			     char *buf)
355{
356	struct channel_path *chp = to_channelpath(dev);
357	ssize_t rc;
358
359	mutex_lock(&chp->lock);
360	if (chp->desc_fmt1.flags & 0x10)
361		rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid);
362	else
363		rc = 0;
364	mutex_unlock(&chp->lock);
365
366	return rc;
367}
368static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
369
370static ssize_t chp_chid_external_show(struct device *dev,
371				      struct device_attribute *attr, char *buf)
372{
373	struct channel_path *chp = to_channelpath(dev);
374	ssize_t rc;
375
376	mutex_lock(&chp->lock);
377	if (chp->desc_fmt1.flags & 0x10)
378		rc = sprintf(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
379	else
380		rc = 0;
381	mutex_unlock(&chp->lock);
382
383	return rc;
384}
385static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
386
 
 
 
 
 
 
 
 
 
 
 
 
 
 
387static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
388				struct bin_attribute *attr, char *buf,
389				loff_t off, size_t count)
390{
391	struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
392	ssize_t rc;
393
394	mutex_lock(&chp->lock);
395	rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
396				     sizeof(chp->desc_fmt3.util_str));
397	mutex_unlock(&chp->lock);
398
399	return rc;
400}
401static BIN_ATTR_RO(util_string,
402		   sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
403
404static struct bin_attribute *chp_bin_attrs[] = {
405	&bin_attr_util_string,
406	NULL,
407};
408
409static struct attribute *chp_attrs[] = {
410	&dev_attr_status.attr,
411	&dev_attr_configure.attr,
412	&dev_attr_type.attr,
413	&dev_attr_cmg.attr,
414	&dev_attr_shared.attr,
415	&dev_attr_chid.attr,
416	&dev_attr_chid_external.attr,
 
417	NULL,
418};
419static struct attribute_group chp_attr_group = {
420	.attrs = chp_attrs,
421	.bin_attrs = chp_bin_attrs,
422};
423static const struct attribute_group *chp_attr_groups[] = {
424	&chp_attr_group,
425	NULL,
426};
427
428static void chp_release(struct device *dev)
429{
430	struct channel_path *cp;
431
432	cp = to_channelpath(dev);
433	kfree(cp);
434}
435
436/**
437 * chp_update_desc - update channel-path description
438 * @chp: channel-path
439 *
440 * Update the channel-path description of the specified channel-path
441 * including channel measurement related information.
442 * Return zero on success, non-zero otherwise.
443 */
444int chp_update_desc(struct channel_path *chp)
445{
446	int rc;
447
448	rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc);
449	if (rc)
450		return rc;
451
452	/*
453	 * Fetching the following data is optional. Not all machines or
454	 * hypervisors implement the required chsc commands.
455	 */
456	chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
457	chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3);
458	chsc_get_channel_measurement_chars(chp);
459
460	return 0;
461}
462
463/**
464 * chp_new - register a new channel-path
465 * @chpid: channel-path ID
466 *
467 * Create and register data structure representing new channel-path. Return
468 * zero on success, non-zero otherwise.
469 */
470int chp_new(struct chp_id chpid)
471{
472	struct channel_subsystem *css = css_by_id(chpid.cssid);
473	struct channel_path *chp;
474	int ret = 0;
475
476	mutex_lock(&css->mutex);
477	if (chp_is_registered(chpid))
478		goto out;
479
480	chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
481	if (!chp) {
482		ret = -ENOMEM;
483		goto out;
484	}
485	/* fill in status, etc. */
486	chp->chpid = chpid;
487	chp->state = 1;
488	chp->dev.parent = &css->device;
489	chp->dev.groups = chp_attr_groups;
490	chp->dev.release = chp_release;
491	mutex_init(&chp->lock);
492
493	/* Obtain channel path description and fill it in. */
494	ret = chp_update_desc(chp);
495	if (ret)
496		goto out_free;
497	if ((chp->desc.flags & 0x80) == 0) {
498		ret = -ENODEV;
499		goto out_free;
500	}
501	dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
502
503	/* make it known to the system */
504	ret = device_register(&chp->dev);
505	if (ret) {
506		CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
507			      chpid.cssid, chpid.id, ret);
508		put_device(&chp->dev);
509		goto out;
510	}
511
512	if (css->cm_enabled) {
513		ret = chp_add_cmg_attr(chp);
514		if (ret) {
515			device_unregister(&chp->dev);
516			goto out;
517		}
518	}
519	css->chps[chpid.id] = chp;
520	goto out;
521out_free:
522	kfree(chp);
523out:
524	mutex_unlock(&css->mutex);
525	return ret;
526}
527
528/**
529 * chp_get_chp_desc - return newly allocated channel-path description
530 * @chpid: channel-path ID
531 *
532 * On success return a newly allocated copy of the channel-path description
533 * data associated with the given channel-path ID. Return %NULL on error.
534 */
535struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid)
536{
537	struct channel_path *chp;
538	struct channel_path_desc_fmt0 *desc;
539
540	chp = chpid_to_chp(chpid);
541	if (!chp)
542		return NULL;
543	desc = kmalloc(sizeof(*desc), GFP_KERNEL);
544	if (!desc)
545		return NULL;
546
547	mutex_lock(&chp->lock);
548	memcpy(desc, &chp->desc, sizeof(*desc));
549	mutex_unlock(&chp->lock);
550	return desc;
551}
552
553/**
554 * chp_process_crw - process channel-path status change
555 * @crw0: channel report-word to handler
556 * @crw1: second channel-report word (always NULL)
557 * @overflow: crw overflow indication
558 *
559 * Handle channel-report-words indicating that the status of a channel-path
560 * has changed.
561 */
562static void chp_process_crw(struct crw *crw0, struct crw *crw1,
563			    int overflow)
564{
565	struct chp_id chpid;
566
567	if (overflow) {
568		css_schedule_eval_all();
569		return;
570	}
571	CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
572		      "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
573		      crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
574		      crw0->erc, crw0->rsid);
575	/*
576	 * Check for solicited machine checks. These are
577	 * created by reset channel path and need not be
578	 * handled here.
579	 */
580	if (crw0->slct) {
581		CIO_CRW_EVENT(2, "solicited machine check for "
582			      "channel path %02X\n", crw0->rsid);
583		return;
584	}
585	chp_id_init(&chpid);
586	chpid.id = crw0->rsid;
587	switch (crw0->erc) {
588	case CRW_ERC_IPARM: /* Path has come. */
589	case CRW_ERC_INIT:
590		chp_new(chpid);
591		chsc_chp_online(chpid);
592		break;
593	case CRW_ERC_PERRI: /* Path has gone. */
594	case CRW_ERC_PERRN:
595		chsc_chp_offline(chpid);
596		break;
597	default:
598		CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
599			      crw0->erc);
600	}
601}
602
603int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
604{
605	int i;
606	int mask;
607
608	for (i = 0; i < 8; i++) {
609		mask = 0x80 >> i;
610		if (!(ssd->path_mask & mask))
611			continue;
612		if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
613			continue;
614		if ((ssd->fla_valid_mask & mask) &&
615		    ((ssd->fla[i] & link->fla_mask) != link->fla))
616			continue;
617		return mask;
618	}
619	return 0;
620}
621EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
622
623static inline int info_bit_num(struct chp_id id)
624{
625	return id.id + id.cssid * (__MAX_CHPID + 1);
626}
627
628/* Force chp_info refresh on next call to info_validate(). */
629static void info_expire(void)
630{
631	mutex_lock(&info_lock);
632	chp_info_expires = jiffies - 1;
633	mutex_unlock(&info_lock);
634}
635
636/* Ensure that chp_info is up-to-date. */
637static int info_update(void)
638{
639	int rc;
640
641	mutex_lock(&info_lock);
642	rc = 0;
643	if (time_after(jiffies, chp_info_expires)) {
644		/* Data is too old, update. */
645		rc = sclp_chp_read_info(&chp_info);
646		chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
647	}
648	mutex_unlock(&info_lock);
649
650	return rc;
651}
652
653/**
654 * chp_info_get_status - retrieve configure status of a channel-path
655 * @chpid: channel-path ID
656 *
657 * On success, return 0 for standby, 1 for configured, 2 for reserved,
658 * 3 for not recognized. Return negative error code on error.
659 */
660int chp_info_get_status(struct chp_id chpid)
661{
662	int rc;
663	int bit;
664
665	rc = info_update();
666	if (rc)
667		return rc;
668
669	bit = info_bit_num(chpid);
670	mutex_lock(&info_lock);
671	if (!chp_test_bit(chp_info.recognized, bit))
672		rc = CHP_STATUS_NOT_RECOGNIZED;
673	else if (chp_test_bit(chp_info.configured, bit))
674		rc = CHP_STATUS_CONFIGURED;
675	else if (chp_test_bit(chp_info.standby, bit))
676		rc = CHP_STATUS_STANDBY;
677	else
678		rc = CHP_STATUS_RESERVED;
679	mutex_unlock(&info_lock);
680
681	return rc;
682}
683
684/* Return configure task for chpid. */
685static enum cfg_task_t cfg_get_task(struct chp_id chpid)
686{
687	return chp_cfg_task[chpid.cssid][chpid.id];
688}
689
690/* Set configure task for chpid. */
691static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
692{
693	chp_cfg_task[chpid.cssid][chpid.id] = cfg;
694}
695
696/* Fetch the first configure task. Set chpid accordingly. */
697static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
698{
699	enum cfg_task_t t = cfg_none;
700
701	chp_id_for_each(chpid) {
702		t = cfg_get_task(*chpid);
703		if (t != cfg_none)
704			break;
705	}
706
707	return t;
708}
709
710/* Perform one configure/deconfigure request. Reschedule work function until
711 * last request. */
712static void cfg_func(struct work_struct *work)
713{
714	struct chp_id chpid;
715	enum cfg_task_t t;
716	int rc;
717
718	spin_lock(&cfg_lock);
719	t = chp_cfg_fetch_task(&chpid);
720	spin_unlock(&cfg_lock);
721
722	switch (t) {
723	case cfg_configure:
724		rc = sclp_chp_configure(chpid);
725		if (rc)
726			CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
727				      "%d\n", chpid.cssid, chpid.id, rc);
728		else {
729			info_expire();
730			chsc_chp_online(chpid);
731		}
732		break;
733	case cfg_deconfigure:
734		rc = sclp_chp_deconfigure(chpid);
735		if (rc)
736			CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
737				      "%d\n", chpid.cssid, chpid.id, rc);
738		else {
739			info_expire();
740			chsc_chp_offline(chpid);
741		}
742		break;
743	case cfg_none:
744		/* Get updated information after last change. */
745		info_update();
746		wake_up_interruptible(&cfg_wait_queue);
747		return;
748	}
749	spin_lock(&cfg_lock);
750	if (t == cfg_get_task(chpid))
751		cfg_set_task(chpid, cfg_none);
752	spin_unlock(&cfg_lock);
753	schedule_work(&cfg_work);
754}
755
756/**
757 * chp_cfg_schedule - schedule chpid configuration request
758 * @chpid: channel-path ID
759 * @configure: Non-zero for configure, zero for deconfigure
760 *
761 * Schedule a channel-path configuration/deconfiguration request.
762 */
763void chp_cfg_schedule(struct chp_id chpid, int configure)
764{
765	CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
766		      configure);
767	spin_lock(&cfg_lock);
768	cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
769	spin_unlock(&cfg_lock);
770	schedule_work(&cfg_work);
771}
772
773/**
774 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
775 * @chpid: channel-path ID
776 *
777 * Cancel an active channel-path deconfiguration request if it has not yet
778 * been performed.
779 */
780void chp_cfg_cancel_deconfigure(struct chp_id chpid)
781{
782	CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
783	spin_lock(&cfg_lock);
784	if (cfg_get_task(chpid) == cfg_deconfigure)
785		cfg_set_task(chpid, cfg_none);
786	spin_unlock(&cfg_lock);
787}
788
789static bool cfg_idle(void)
790{
791	struct chp_id chpid;
792	enum cfg_task_t t;
793
794	spin_lock(&cfg_lock);
795	t = chp_cfg_fetch_task(&chpid);
796	spin_unlock(&cfg_lock);
797
798	return t == cfg_none;
799}
800
801static int cfg_wait_idle(void)
802{
803	if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
804		return -ERESTARTSYS;
805	return 0;
806}
807
808static int __init chp_init(void)
809{
810	struct chp_id chpid;
811	int state, ret;
812
813	ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
814	if (ret)
815		return ret;
816	INIT_WORK(&cfg_work, cfg_func);
817	init_waitqueue_head(&cfg_wait_queue);
818	if (info_update())
819		return 0;
820	/* Register available channel-paths. */
821	chp_id_for_each(&chpid) {
822		state = chp_info_get_status(chpid);
823		if (state == CHP_STATUS_CONFIGURED ||
824		    state == CHP_STATUS_STANDBY)
825			chp_new(chpid);
826	}
827
828	return 0;
829}
830
831subsys_initcall(chp_init);