1 // SPDX-License-Identifier: GPL-2.0
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>
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>
27 #include "cio_debug.h"
30 #define to_channelpath(device) container_of(device, struct channel_path, dev)
31 #define CHP_INFO_UPDATE_INTERVAL 1*HZ
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);
43 /* Map for channel-path status. */
44 static struct sclp_chp_info chp_info;
45 static DEFINE_MUTEX(info_lock);
47 /* Time after which channel-path status may be outdated. */
48 static unsigned long chp_info_expires;
50 static struct work_struct cfg_work;
52 /* Wait queue for configure completion events. */
53 static wait_queue_head_t cfg_wait_queue;
55 /* Set vary state for given chpid. */
56 static void set_chp_logically_online(struct chp_id chpid, int onoff)
58 chpid_to_chp(chpid)->state = onoff;
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)
65 return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
69 * chp_get_sch_opm - return opm for subchannel
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.
75 u8 chp_get_sch_opm(struct subchannel *sch)
83 for (i = 0; i < 8; i++) {
85 chpid.id = sch->schib.pmcw.chpid[i];
86 if (chp_get_status(chpid) != 0)
91 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
94 * chp_is_registered - check if a channel-path is registered
95 * @chpid: channel-path ID
97 * Return non-zero if a channel-path with the given chpid is registered,
100 int chp_is_registered(struct chp_id chpid)
102 return chpid_to_chp(chpid) != NULL;
106 * Function: s390_vary_chpid
107 * Varies the specified chpid online or offline
109 static int s390_vary_chpid(struct chp_id chpid, int on)
114 sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
116 CIO_TRACE_EVENT(2, dbf_text);
118 status = chp_get_status(chpid);
122 set_chp_logically_online(chpid, on);
123 chsc_chp_vary(chpid, on);
128 * Channel measurement related functions
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)
135 struct channel_path *chp;
136 struct device *device;
138 device = kobj_to_dev(kobj);
139 chp = to_channelpath(device);
143 return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
144 sizeof(chp->cmg_chars));
147 static const struct bin_attribute chp_measurement_chars_attr = {
149 .name = "measurement_chars",
152 .size = sizeof(struct cmg_chars),
153 .read = chp_measurement_chars_read,
156 static void chp_measurement_copy_block(struct cmg_entry *buf,
157 struct channel_subsystem *css,
161 struct cmg_entry *entry, reference_buf;
164 if (chpid.id < 128) {
165 area = css->cub_addr1;
168 area = css->cub_addr2;
169 idx = chpid.id - 128;
171 entry = area + (idx * sizeof(struct cmg_entry));
173 memcpy(buf, entry, sizeof(*entry));
174 memcpy(&reference_buf, entry, sizeof(*entry));
175 } while (reference_buf.values[0] != buf->values[0]);
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)
182 struct channel_path *chp;
183 struct channel_subsystem *css;
184 struct device *device;
187 device = kobj_to_dev(kobj);
188 chp = to_channelpath(device);
189 css = to_css(chp->dev.parent);
191 size = sizeof(struct cmg_entry);
193 /* Only allow single reads. */
194 if (off || count < size)
196 chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
201 static const struct bin_attribute chp_measurement_attr = {
203 .name = "measurement",
206 .size = sizeof(struct cmg_entry),
207 .read = chp_measurement_read,
210 void chp_remove_cmg_attr(struct channel_path *chp)
212 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
213 device_remove_bin_file(&chp->dev, &chp_measurement_attr);
216 int chp_add_cmg_attr(struct channel_path *chp)
220 ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
223 ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
225 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
230 * Files for the channel path entries.
232 static ssize_t chp_status_show(struct device *dev,
233 struct device_attribute *attr, char *buf)
235 struct channel_path *chp = to_channelpath(dev);
238 mutex_lock(&chp->lock);
240 mutex_unlock(&chp->lock);
242 return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
245 static ssize_t chp_status_write(struct device *dev,
246 struct device_attribute *attr,
247 const char *buf, size_t count)
249 struct channel_path *cp = to_channelpath(dev);
254 num_args = sscanf(buf, "%5s", cmd);
258 /* Wait until previous actions have settled. */
259 css_wait_for_slow_path();
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);
272 return error < 0 ? error : count;
275 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
277 static ssize_t chp_configure_show(struct device *dev,
278 struct device_attribute *attr, char *buf)
280 struct channel_path *cp;
283 cp = to_channelpath(dev);
284 status = chp_info_get_status(cp->chpid);
288 return snprintf(buf, PAGE_SIZE, "%d\n", status);
291 static int cfg_wait_idle(void);
293 static ssize_t chp_configure_write(struct device *dev,
294 struct device_attribute *attr,
295 const char *buf, size_t count)
297 struct channel_path *cp;
301 if (sscanf(buf, "%d %c", &val, &delim) != 1)
303 if (val != 0 && val != 1)
305 cp = to_channelpath(dev);
306 chp_cfg_schedule(cp->chpid, val);
312 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
314 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
317 struct channel_path *chp = to_channelpath(dev);
320 mutex_lock(&chp->lock);
321 type = chp->desc.desc;
322 mutex_unlock(&chp->lock);
323 return sprintf(buf, "%x\n", type);
326 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
328 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
331 struct channel_path *chp = to_channelpath(dev);
335 if (chp->cmg == -1) /* channel measurements not available */
336 return sprintf(buf, "unknown\n");
337 return sprintf(buf, "%x\n", chp->cmg);
340 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
342 static ssize_t chp_shared_show(struct device *dev,
343 struct device_attribute *attr, char *buf)
345 struct channel_path *chp = to_channelpath(dev);
349 if (chp->shared == -1) /* channel measurements not available */
350 return sprintf(buf, "unknown\n");
351 return sprintf(buf, "%x\n", chp->shared);
354 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
356 static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
359 struct channel_path *chp = to_channelpath(dev);
362 mutex_lock(&chp->lock);
363 if (chp->desc_fmt1.flags & 0x10)
364 rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid);
367 mutex_unlock(&chp->lock);
371 static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
373 static ssize_t chp_chid_external_show(struct device *dev,
374 struct device_attribute *attr, char *buf)
376 struct channel_path *chp = to_channelpath(dev);
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);
384 mutex_unlock(&chp->lock);
388 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
390 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
391 struct bin_attribute *attr, char *buf,
392 loff_t off, size_t count)
394 struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
397 mutex_lock(&chp->lock);
398 rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
399 sizeof(chp->desc_fmt3.util_str));
400 mutex_unlock(&chp->lock);
404 static BIN_ATTR_RO(util_string,
405 sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
407 static struct bin_attribute *chp_bin_attrs[] = {
408 &bin_attr_util_string,
412 static struct attribute *chp_attrs[] = {
413 &dev_attr_status.attr,
414 &dev_attr_configure.attr,
417 &dev_attr_shared.attr,
419 &dev_attr_chid_external.attr,
422 static struct attribute_group chp_attr_group = {
424 .bin_attrs = chp_bin_attrs,
426 static const struct attribute_group *chp_attr_groups[] = {
431 static void chp_release(struct device *dev)
433 struct channel_path *cp;
435 cp = to_channelpath(dev);
440 * chp_update_desc - update channel-path description
443 * Update the channel-path description of the specified channel-path
444 * including channel measurement related information.
445 * Return zero on success, non-zero otherwise.
447 int chp_update_desc(struct channel_path *chp)
451 rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc);
456 * Fetching the following data is optional. Not all machines or
457 * hypervisors implement the required chsc commands.
459 chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
460 chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3);
461 chsc_get_channel_measurement_chars(chp);
467 * chp_new - register a new channel-path
468 * @chpid: channel-path ID
470 * Create and register data structure representing new channel-path. Return
471 * zero on success, non-zero otherwise.
473 int chp_new(struct chp_id chpid)
475 struct channel_subsystem *css = css_by_id(chpid.cssid);
476 struct channel_path *chp;
479 mutex_lock(&css->mutex);
480 if (chp_is_registered(chpid))
483 chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
488 /* fill in status, etc. */
491 chp->dev.parent = &css->device;
492 chp->dev.groups = chp_attr_groups;
493 chp->dev.release = chp_release;
494 mutex_init(&chp->lock);
496 /* Obtain channel path description and fill it in. */
497 ret = chp_update_desc(chp);
500 if ((chp->desc.flags & 0x80) == 0) {
504 dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
506 /* make it known to the system */
507 ret = device_register(&chp->dev);
509 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
510 chpid.cssid, chpid.id, ret);
511 put_device(&chp->dev);
515 if (css->cm_enabled) {
516 ret = chp_add_cmg_attr(chp);
518 device_unregister(&chp->dev);
522 css->chps[chpid.id] = chp;
527 mutex_unlock(&css->mutex);
532 * chp_get_chp_desc - return newly allocated channel-path description
533 * @chpid: channel-path ID
535 * On success return a newly allocated copy of the channel-path description
536 * data associated with the given channel-path ID. Return %NULL on error.
538 struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid)
540 struct channel_path *chp;
541 struct channel_path_desc_fmt0 *desc;
543 chp = chpid_to_chp(chpid);
546 desc = kmalloc(sizeof(*desc), GFP_KERNEL);
550 mutex_lock(&chp->lock);
551 memcpy(desc, &chp->desc, sizeof(*desc));
552 mutex_unlock(&chp->lock);
557 * chp_process_crw - process channel-path status change
558 * @crw0: channel report-word to handler
559 * @crw1: second channel-report word (always NULL)
560 * @overflow: crw overflow indication
562 * Handle channel-report-words indicating that the status of a channel-path
565 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
571 css_schedule_eval_all();
574 CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
575 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
576 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
577 crw0->erc, crw0->rsid);
579 * Check for solicited machine checks. These are
580 * created by reset channel path and need not be
584 CIO_CRW_EVENT(2, "solicited machine check for "
585 "channel path %02X\n", crw0->rsid);
589 chpid.id = crw0->rsid;
591 case CRW_ERC_IPARM: /* Path has come. */
594 chsc_chp_online(chpid);
596 case CRW_ERC_PERRI: /* Path has gone. */
598 chsc_chp_offline(chpid);
601 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
606 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
611 for (i = 0; i < 8; i++) {
613 if (!(ssd->path_mask & mask))
615 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
617 if ((ssd->fla_valid_mask & mask) &&
618 ((ssd->fla[i] & link->fla_mask) != link->fla))
624 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
626 static inline int info_bit_num(struct chp_id id)
628 return id.id + id.cssid * (__MAX_CHPID + 1);
631 /* Force chp_info refresh on next call to info_validate(). */
632 static void info_expire(void)
634 mutex_lock(&info_lock);
635 chp_info_expires = jiffies - 1;
636 mutex_unlock(&info_lock);
639 /* Ensure that chp_info is up-to-date. */
640 static int info_update(void)
644 mutex_lock(&info_lock);
646 if (time_after(jiffies, chp_info_expires)) {
647 /* Data is too old, update. */
648 rc = sclp_chp_read_info(&chp_info);
649 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
651 mutex_unlock(&info_lock);
657 * chp_info_get_status - retrieve configure status of a channel-path
658 * @chpid: channel-path ID
660 * On success, return 0 for standby, 1 for configured, 2 for reserved,
661 * 3 for not recognized. Return negative error code on error.
663 int chp_info_get_status(struct chp_id chpid)
672 bit = info_bit_num(chpid);
673 mutex_lock(&info_lock);
674 if (!chp_test_bit(chp_info.recognized, bit))
675 rc = CHP_STATUS_NOT_RECOGNIZED;
676 else if (chp_test_bit(chp_info.configured, bit))
677 rc = CHP_STATUS_CONFIGURED;
678 else if (chp_test_bit(chp_info.standby, bit))
679 rc = CHP_STATUS_STANDBY;
681 rc = CHP_STATUS_RESERVED;
682 mutex_unlock(&info_lock);
687 /* Return configure task for chpid. */
688 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
690 return chp_cfg_task[chpid.cssid][chpid.id];
693 /* Set configure task for chpid. */
694 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
696 chp_cfg_task[chpid.cssid][chpid.id] = cfg;
699 /* Fetch the first configure task. Set chpid accordingly. */
700 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
702 enum cfg_task_t t = cfg_none;
704 chp_id_for_each(chpid) {
705 t = cfg_get_task(*chpid);
713 /* Perform one configure/deconfigure request. Reschedule work function until
715 static void cfg_func(struct work_struct *work)
721 spin_lock(&cfg_lock);
722 t = chp_cfg_fetch_task(&chpid);
723 spin_unlock(&cfg_lock);
727 rc = sclp_chp_configure(chpid);
729 CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
730 "%d\n", chpid.cssid, chpid.id, rc);
733 chsc_chp_online(chpid);
736 case cfg_deconfigure:
737 rc = sclp_chp_deconfigure(chpid);
739 CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
740 "%d\n", chpid.cssid, chpid.id, rc);
743 chsc_chp_offline(chpid);
747 /* Get updated information after last change. */
749 wake_up_interruptible(&cfg_wait_queue);
752 spin_lock(&cfg_lock);
753 if (t == cfg_get_task(chpid))
754 cfg_set_task(chpid, cfg_none);
755 spin_unlock(&cfg_lock);
756 schedule_work(&cfg_work);
760 * chp_cfg_schedule - schedule chpid configuration request
761 * @chpid: channel-path ID
762 * @configure: Non-zero for configure, zero for deconfigure
764 * Schedule a channel-path configuration/deconfiguration request.
766 void chp_cfg_schedule(struct chp_id chpid, int configure)
768 CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
770 spin_lock(&cfg_lock);
771 cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
772 spin_unlock(&cfg_lock);
773 schedule_work(&cfg_work);
777 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
778 * @chpid: channel-path ID
780 * Cancel an active channel-path deconfiguration request if it has not yet
783 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
785 CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
786 spin_lock(&cfg_lock);
787 if (cfg_get_task(chpid) == cfg_deconfigure)
788 cfg_set_task(chpid, cfg_none);
789 spin_unlock(&cfg_lock);
792 static bool cfg_idle(void)
797 spin_lock(&cfg_lock);
798 t = chp_cfg_fetch_task(&chpid);
799 spin_unlock(&cfg_lock);
801 return t == cfg_none;
804 static int cfg_wait_idle(void)
806 if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
811 static int __init chp_init(void)
816 ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
819 INIT_WORK(&cfg_work, cfg_func);
820 init_waitqueue_head(&cfg_wait_queue);
823 /* Register available channel-paths. */
824 chp_id_for_each(&chpid) {
825 state = chp_info_get_status(chpid);
826 if (state == CHP_STATUS_CONFIGURED ||
827 state == CHP_STATUS_STANDBY)
834 subsys_initcall(chp_init);