chp.c

  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 47/* Time after which channel-path status may be outdated.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 DECLARE_WAIT_QUEUE_HEAD(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	scnprintf(dbf_text, sizeof(dbf_text),
115		  on ? "varyon%x.%02x" : "varyoff%x.%02x",
116		  chpid.cssid, chpid.id);
117	CIO_TRACE_EVENT(2, dbf_text);
118
119	status = chp_get_status(chpid);
120	if (!on && !status)
121		return 0;
122
123	set_chp_logically_online(chpid, on);
124	chsc_chp_vary(chpid, on);
125	return 0;
126}
127
128/*
129 * Channel measurement related functions
130 */
131static ssize_t measurement_chars_read(struct file *filp, struct kobject *kobj,
132				      const 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}
146static const BIN_ATTR_ADMIN_RO(measurement_chars, sizeof(struct cmg_chars));
147
148static ssize_t measurement_chars_full_read(struct file *filp,
149					   struct kobject *kobj,
150					   const struct bin_attribute *bin_attr,
151					   char *buf, loff_t off, size_t count)
152{
153	struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
154
155	return memory_read_from_buffer(buf, count, &off, &chp->cmcb,
156				       sizeof(chp->cmcb));
157}
158static BIN_ATTR_ADMIN_RO(measurement_chars_full, sizeof(struct cmg_cmcb));
159
160static ssize_t chp_measurement_copy_block(void *buf, loff_t off, size_t count,
161					  struct kobject *kobj, bool extended)
162{
163	struct channel_path *chp;
164	struct channel_subsystem *css;
165	struct device *device;
166	unsigned int size;
167	void *area, *entry;
168	int id, idx;
169
170	device = kobj_to_dev(kobj);
171	chp = to_channelpath(device);
172	css = to_css(chp->dev.parent);
173	id = chp->chpid.id;
174
175	if (extended) {
176		/* Check if extended measurement data is available. */
177		if (!chp->extended)
178			return 0;
179
180		size = sizeof(struct cmg_ext_entry);
181		area = css->ecub[id / CSS_ECUES_PER_PAGE];
182		idx = id % CSS_ECUES_PER_PAGE;
183	} else {
184		size = sizeof(struct cmg_entry);
185		area = css->cub[id / CSS_CUES_PER_PAGE];
186		idx = id % CSS_CUES_PER_PAGE;
187	}
188	entry = area + (idx * size);
189
190	/* Only allow single reads. */
191	if (off || count < size)
192		return 0;
193
194	memcpy(buf, entry, size);
195
196	return size;
197}
198
199static ssize_t measurement_read(struct file *filp, struct kobject *kobj,
200				const struct bin_attribute *bin_attr,
201				char *buf, loff_t off, size_t count)
202{
203	return chp_measurement_copy_block(buf, off, count, kobj, false);
204}
205static const BIN_ATTR_ADMIN_RO(measurement, sizeof(struct cmg_entry));
206
207static ssize_t ext_measurement_read(struct file *filp, struct kobject *kobj,
208				    const struct bin_attribute *bin_attr,
209				    char *buf, loff_t off, size_t count)
210{
211	return chp_measurement_copy_block(buf, off, count, kobj, true);
212}
213static const BIN_ATTR_ADMIN_RO(ext_measurement, sizeof(struct cmg_ext_entry));
214
215static const struct bin_attribute *measurement_attrs[] = {
216	&bin_attr_measurement_chars,
217	&bin_attr_measurement_chars_full,
218	&bin_attr_measurement,
219	&bin_attr_ext_measurement,
220	NULL,
221};
222BIN_ATTRIBUTE_GROUPS(measurement);
223
224void chp_remove_cmg_attr(struct channel_path *chp)
225{
226	device_remove_groups(&chp->dev, measurement_groups);
227}
228
229int chp_add_cmg_attr(struct channel_path *chp)
230{
231	return device_add_groups(&chp->dev, measurement_groups);
232}
233
234/*
235 * Files for the channel path entries.
236 */
237static ssize_t chp_status_show(struct device *dev,
238			       struct device_attribute *attr, char *buf)
239{
240	struct channel_path *chp = to_channelpath(dev);
241	int status;
242
243	mutex_lock(&chp->lock);
244	status = chp->state;
245	mutex_unlock(&chp->lock);
246
247	return status ? sysfs_emit(buf, "online\n") : sysfs_emit(buf, "offline\n");
248}
249
250static ssize_t chp_status_write(struct device *dev,
251				struct device_attribute *attr,
252				const char *buf, size_t count)
253{
254	struct channel_path *cp = to_channelpath(dev);
255	char cmd[10];
256	int num_args;
257	int error;
258
259	num_args = sscanf(buf, "%5s", cmd);
260	if (!num_args)
261		return count;
262
263	/* Wait until previous actions have settled. */
264	css_wait_for_slow_path();
265
266	if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
267		mutex_lock(&cp->lock);
268		error = s390_vary_chpid(cp->chpid, 1);
269		mutex_unlock(&cp->lock);
270	} else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
271		mutex_lock(&cp->lock);
272		error = s390_vary_chpid(cp->chpid, 0);
273		mutex_unlock(&cp->lock);
274	} else
275		error = -EINVAL;
276
277	return error < 0 ? error : count;
278}
279
280static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
281
282static ssize_t chp_configure_show(struct device *dev,
283				  struct device_attribute *attr, char *buf)
284{
285	struct channel_path *cp;
286	int status;
287
288	cp = to_channelpath(dev);
289	status = chp_info_get_status(cp->chpid);
290	if (status < 0)
291		return status;
292
293	return sysfs_emit(buf, "%d\n", status);
294}
295
296static int cfg_wait_idle(void);
297
298static ssize_t chp_configure_write(struct device *dev,
299				   struct device_attribute *attr,
300				   const char *buf, size_t count)
301{
302	struct channel_path *cp;
303	int val;
304	char delim;
305
306	if (sscanf(buf, "%d %c", &val, &delim) != 1)
307		return -EINVAL;
308	if (val != 0 && val != 1)
309		return -EINVAL;
310	cp = to_channelpath(dev);
311	chp_cfg_schedule(cp->chpid, val);
312	cfg_wait_idle();
313
314	return count;
315}
316
317static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
318
319static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
320			     char *buf)
321{
322	struct channel_path *chp = to_channelpath(dev);
323	u8 type;
324
325	mutex_lock(&chp->lock);
326	type = chp->desc.desc;
327	mutex_unlock(&chp->lock);
328	return sysfs_emit(buf, "%x\n", type);
329}
330
331static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
332
333static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
334			    char *buf)
335{
336	struct channel_path *chp = to_channelpath(dev);
337
338	if (!chp)
339		return 0;
340	if (chp->cmg == -1) /* channel measurements not available */
341		return sysfs_emit(buf, "unknown\n");
342	return sysfs_emit(buf, "%d\n", chp->cmg);
343}
344
345static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
346
347static ssize_t chp_shared_show(struct device *dev,
348			       struct device_attribute *attr, char *buf)
349{
350	struct channel_path *chp = to_channelpath(dev);
351
352	if (!chp)
353		return 0;
354	if (chp->shared == -1) /* channel measurements not available */
355		return sysfs_emit(buf, "unknown\n");
356	return sysfs_emit(buf, "%x\n", chp->shared);
357}
358
359static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
360
361static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
362			     char *buf)
363{
364	struct channel_path *chp = to_channelpath(dev);
365	ssize_t rc;
366
367	mutex_lock(&chp->lock);
368	if (chp->desc_fmt1.flags & 0x10)
369		rc = sysfs_emit(buf, "%04x\n", chp->desc_fmt1.chid);
370	else
371		rc = 0;
372	mutex_unlock(&chp->lock);
373
374	return rc;
375}
376static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
377
378static ssize_t chp_chid_external_show(struct device *dev,
379				      struct device_attribute *attr, char *buf)
380{
381	struct channel_path *chp = to_channelpath(dev);
382	ssize_t rc;
383
384	mutex_lock(&chp->lock);
385	if (chp->desc_fmt1.flags & 0x10)
386		rc = sysfs_emit(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
387	else
388		rc = 0;
389	mutex_unlock(&chp->lock);
390
391	return rc;
392}
393static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
394
395static ssize_t chp_esc_show(struct device *dev,
396			    struct device_attribute *attr, char *buf)
397{
398	struct channel_path *chp = to_channelpath(dev);
399	ssize_t rc;
400
401	mutex_lock(&chp->lock);
402	rc = sysfs_emit(buf, "%x\n", chp->desc_fmt1.esc);
403	mutex_unlock(&chp->lock);
404
405	return rc;
406}
407static DEVICE_ATTR(esc, 0444, chp_esc_show, NULL);
408
409static char apply_max_suffix(unsigned long *value, unsigned long base)
410{
411	static char suffixes[] = { 0, 'K', 'M', 'G', 'T' };
412	int i;
413
414	for (i = 0; i < ARRAY_SIZE(suffixes) - 1; i++) {
415		if (*value < base || *value % base != 0)
416			break;
417		*value /= base;
418	}
419
420	return suffixes[i];
421}
422
423static ssize_t speed_bps_show(struct device *dev,
424			      struct device_attribute *attr, char *buf)
425{
426	struct channel_path *chp = to_channelpath(dev);
427	unsigned long speed = chp->speed;
428	char suffix;
429
430	suffix = apply_max_suffix(&speed, 1000);
431
432	return suffix ? sysfs_emit(buf, "%lu%c\n", speed, suffix) :
433			sysfs_emit(buf, "%lu\n", speed);
434}
435
436static DEVICE_ATTR_RO(speed_bps);
437
438static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
439				const struct bin_attribute *attr, char *buf,
440				loff_t off, size_t count)
441{
442	struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
443	ssize_t rc;
444
445	mutex_lock(&chp->lock);
446	rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
447				     sizeof(chp->desc_fmt3.util_str));
448	mutex_unlock(&chp->lock);
449
450	return rc;
451}
452static const BIN_ATTR_RO(util_string,
453			 sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
454
455static const struct bin_attribute *const chp_bin_attrs[] = {
456	&bin_attr_util_string,
457	NULL,
458};
459
460static struct attribute *chp_attrs[] = {
461	&dev_attr_status.attr,
462	&dev_attr_configure.attr,
463	&dev_attr_type.attr,
464	&dev_attr_cmg.attr,
465	&dev_attr_shared.attr,
466	&dev_attr_chid.attr,
467	&dev_attr_chid_external.attr,
468	&dev_attr_esc.attr,
469	&dev_attr_speed_bps.attr,
470	NULL,
471};
472static const struct attribute_group chp_attr_group = {
473	.attrs = chp_attrs,
474	.bin_attrs = chp_bin_attrs,
475};
476static const struct attribute_group *chp_attr_groups[] = {
477	&chp_attr_group,
478	NULL,
479};
480
481static void chp_release(struct device *dev)
482{
483	struct channel_path *cp;
484
485	cp = to_channelpath(dev);
486	kfree(cp);
487}
488
489/**
490 * chp_update_desc - update channel-path description
491 * @chp: channel-path
492 *
493 * Update the channel-path description of the specified channel-path
494 * including channel measurement related information.
495 * Return zero on success, non-zero otherwise.
496 */
497int chp_update_desc(struct channel_path *chp)
498{
499	int rc;
500
501	rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc);
502	if (rc)
503		return rc;
504
505	/*
506	 * Fetching the following data is optional. Not all machines or
507	 * hypervisors implement the required chsc commands.
508	 */
509	chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
510	chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3);
511	chsc_get_channel_measurement_chars(chp);
512
513	return 0;
514}
515
516/**
517 * chp_new - register a new channel-path
518 * @chpid: channel-path ID
519 *
520 * Create and register data structure representing new channel-path. Return
521 * zero on success, non-zero otherwise.
522 */
523int chp_new(struct chp_id chpid)
524{
525	struct channel_subsystem *css = css_by_id(chpid.cssid);
526	struct channel_path *chp;
527	int ret = 0;
528
529	mutex_lock(&css->mutex);
530	if (chp_is_registered(chpid))
531		goto out;
532
533	chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
534	if (!chp) {
535		ret = -ENOMEM;
536		goto out;
537	}
538	/* fill in status, etc. */
539	chp->chpid = chpid;
540	chp->state = 1;
541	chp->dev.parent = &css->device;
542	chp->dev.groups = chp_attr_groups;
543	chp->dev.release = chp_release;
544	mutex_init(&chp->lock);
545
546	/* Obtain channel path description and fill it in. */
547	ret = chp_update_desc(chp);
548	if (ret)
549		goto out_free;
550	if ((chp->desc.flags & 0x80) == 0) {
551		ret = -ENODEV;
552		goto out_free;
553	}
554	dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
555
556	/* make it known to the system */
557	ret = device_register(&chp->dev);
558	if (ret) {
559		CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
560			      chpid.cssid, chpid.id, ret);
561		put_device(&chp->dev);
562		goto out;
563	}
564
565	if (css->cm_enabled) {
566		ret = chp_add_cmg_attr(chp);
567		if (ret) {
568			device_unregister(&chp->dev);
569			goto out;
570		}
571	}
572	css->chps[chpid.id] = chp;
573	goto out;
574out_free:
575	kfree(chp);
576out:
577	mutex_unlock(&css->mutex);
578	return ret;
579}
580
581/**
582 * chp_get_chp_desc - return newly allocated channel-path description
583 * @chpid: channel-path ID
584 *
585 * On success return a newly allocated copy of the channel-path description
586 * data associated with the given channel-path ID. Return %NULL on error.
587 */
588struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid)
589{
590	struct channel_path *chp;
591	struct channel_path_desc_fmt0 *desc;
592
593	chp = chpid_to_chp(chpid);
594	if (!chp)
595		return NULL;
596	desc = kmalloc(sizeof(*desc), GFP_KERNEL);
597	if (!desc)
598		return NULL;
599
600	mutex_lock(&chp->lock);
601	memcpy(desc, &chp->desc, sizeof(*desc));
602	mutex_unlock(&chp->lock);
603	return desc;
604}
605
606/**
607 * chp_process_crw - process channel-path status change
608 * @crw0: channel report-word to handler
609 * @crw1: second channel-report word (always NULL)
610 * @overflow: crw overflow indication
611 *
612 * Handle channel-report-words indicating that the status of a channel-path
613 * has changed.
614 */
615static void chp_process_crw(struct crw *crw0, struct crw *crw1,
616			    int overflow)
617{
618	struct chp_id chpid;
619
620	if (overflow) {
621		css_schedule_eval_all();
622		return;
623	}
624	CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
625		      "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
626		      crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
627		      crw0->erc, crw0->rsid);
628	/*
629	 * Check for solicited machine checks. These are
630	 * created by reset channel path and need not be
631	 * handled here.
632	 */
633	if (crw0->slct) {
634		CIO_CRW_EVENT(2, "solicited machine check for "
635			      "channel path %02X\n", crw0->rsid);
636		return;
637	}
638	chp_id_init(&chpid);
639	chpid.id = crw0->rsid;
640	switch (crw0->erc) {
641	case CRW_ERC_IPARM: /* Path has come. */
642	case CRW_ERC_INIT:
643		chp_new(chpid);
644		chsc_chp_online(chpid);
645		break;
646	case CRW_ERC_PERRI: /* Path has gone. */
647	case CRW_ERC_PERRN:
648		chsc_chp_offline(chpid);
649		break;
650	default:
651		CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
652			      crw0->erc);
653	}
654}
655
656int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
657{
658	int i;
659	int mask;
660
661	for (i = 0; i < 8; i++) {
662		mask = 0x80 >> i;
663		if (!(ssd->path_mask & mask))
664			continue;
665		if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
666			continue;
667		if ((ssd->fla_valid_mask & mask) &&
668		    ((ssd->fla[i] & link->fla_mask) != link->fla))
669			continue;
670		return mask;
671	}
672	return 0;
673}
674EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
675
676static inline int info_bit_num(struct chp_id id)
677{
678	return id.id + id.cssid * (__MAX_CHPID + 1);
679}
680
681/* Force chp_info refresh on next call to info_validate(). */
682static void info_expire(void)
683{
684	mutex_lock(&info_lock);
685	chp_info_expires = jiffies - 1;
686	mutex_unlock(&info_lock);
687}
688
689/* Ensure that chp_info is up-to-date. */
690static int info_update(void)
691{
692	int rc;
693
694	mutex_lock(&info_lock);
695	rc = 0;
696	if (time_after(jiffies, chp_info_expires)) {
697		/* Data is too old, update. */
698		rc = sclp_chp_read_info(&chp_info);
699		if (!rc)
700			chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL;
701	}
702	mutex_unlock(&info_lock);
703
704	return rc;
705}
706
707/**
708 * chp_info_get_status - retrieve configure status of a channel-path
709 * @chpid: channel-path ID
710 *
711 * On success, return 0 for standby, 1 for configured, 2 for reserved,
712 * 3 for not recognized. Return negative error code on error.
713 */
714int chp_info_get_status(struct chp_id chpid)
715{
716	int rc;
717	int bit;
718
719	rc = info_update();
720	if (rc)
721		return rc;
722
723	bit = info_bit_num(chpid);
724	mutex_lock(&info_lock);
725	if (!chp_test_bit(chp_info.recognized, bit))
726		rc = CHP_STATUS_NOT_RECOGNIZED;
727	else if (chp_test_bit(chp_info.configured, bit))
728		rc = CHP_STATUS_CONFIGURED;
729	else if (chp_test_bit(chp_info.standby, bit))
730		rc = CHP_STATUS_STANDBY;
731	else
732		rc = CHP_STATUS_RESERVED;
733	mutex_unlock(&info_lock);
734
735	return rc;
736}
737
738/* Return configure task for chpid. */
739static enum cfg_task_t cfg_get_task(struct chp_id chpid)
740{
741	return chp_cfg_task[chpid.cssid][chpid.id];
742}
743
744/* Set configure task for chpid. */
745static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
746{
747	chp_cfg_task[chpid.cssid][chpid.id] = cfg;
748}
749
750/* Fetch the first configure task. Set chpid accordingly. */
751static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
752{
753	enum cfg_task_t t = cfg_none;
754
755	chp_id_for_each(chpid) {
756		t = cfg_get_task(*chpid);
757		if (t != cfg_none)
758			break;
759	}
760
761	return t;
762}
763
764/* Perform one configure/deconfigure request. Reschedule work function until
765 * last request. */
766static void cfg_func(struct work_struct *work)
767{
768	struct chp_id chpid;
769	enum cfg_task_t t;
770	int rc;
771
772	spin_lock(&cfg_lock);
773	t = chp_cfg_fetch_task(&chpid);
774	spin_unlock(&cfg_lock);
775
776	switch (t) {
777	case cfg_configure:
778		rc = sclp_chp_configure(chpid);
779		if (rc)
780			CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
781				      "%d\n", chpid.cssid, chpid.id, rc);
782		else {
783			info_expire();
784			chsc_chp_online(chpid);
785		}
786		break;
787	case cfg_deconfigure:
788		rc = sclp_chp_deconfigure(chpid);
789		if (rc)
790			CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
791				      "%d\n", chpid.cssid, chpid.id, rc);
792		else {
793			info_expire();
794			chsc_chp_offline(chpid);
795		}
796		break;
797	case cfg_none:
798		/* Get updated information after last change. */
799		info_update();
800		wake_up_interruptible(&cfg_wait_queue);
801		return;
802	}
803	spin_lock(&cfg_lock);
804	if (t == cfg_get_task(chpid))
805		cfg_set_task(chpid, cfg_none);
806	spin_unlock(&cfg_lock);
807	schedule_work(&cfg_work);
808}
809
810/**
811 * chp_cfg_schedule - schedule chpid configuration request
812 * @chpid: channel-path ID
813 * @configure: Non-zero for configure, zero for deconfigure
814 *
815 * Schedule a channel-path configuration/deconfiguration request.
816 */
817void chp_cfg_schedule(struct chp_id chpid, int configure)
818{
819	CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
820		      configure);
821	spin_lock(&cfg_lock);
822	cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
823	spin_unlock(&cfg_lock);
824	schedule_work(&cfg_work);
825}
826
827/**
828 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
829 * @chpid: channel-path ID
830 *
831 * Cancel an active channel-path deconfiguration request if it has not yet
832 * been performed.
833 */
834void chp_cfg_cancel_deconfigure(struct chp_id chpid)
835{
836	CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
837	spin_lock(&cfg_lock);
838	if (cfg_get_task(chpid) == cfg_deconfigure)
839		cfg_set_task(chpid, cfg_none);
840	spin_unlock(&cfg_lock);
841}
842
843static bool cfg_idle(void)
844{
845	struct chp_id chpid;
846	enum cfg_task_t t;
847
848	spin_lock(&cfg_lock);
849	t = chp_cfg_fetch_task(&chpid);
850	spin_unlock(&cfg_lock);
851
852	return t == cfg_none;
853}
854
855static int cfg_wait_idle(void)
856{
857	if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
858		return -ERESTARTSYS;
859	return 0;
860}
861
862static int __init chp_init(void)
863{
864	struct chp_id chpid;
865	int state, ret;
866
867	ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
868	if (ret)
869		return ret;
870	INIT_WORK(&cfg_work, cfg_func);
871	if (info_update())
872		return 0;
873	/* Register available channel-paths. */
874	chp_id_for_each(&chpid) {
875		state = chp_info_get_status(chpid);
876		if (state == CHP_STATUS_CONFIGURED ||
877		    state == CHP_STATUS_STANDBY)
878			chp_new(chpid);
879	}
880
881	return 0;
882}
883
884subsys_initcall(chp_init);