2 * PAV alias management for the DASD ECKD discipline
4 * Copyright IBM Corp. 2007
5 * Author(s): Stefan Weinhuber <wein@de.ibm.com>
8 #define KMSG_COMPONENT "dasd-eckd"
10 #include <linux/list.h>
11 #include <linux/slab.h>
12 #include <asm/ebcdic.h>
14 #include "dasd_eckd.h"
18 #endif /* PRINTK_HEADER */
19 #define PRINTK_HEADER "dasd(eckd):"
23 * General concept of alias management:
24 * - PAV and DASD alias management is specific to the eckd discipline.
25 * - A device is connected to an lcu as long as the device exists.
26 * dasd_alias_make_device_known_to_lcu will be called wenn the
27 * device is checked by the eckd discipline and
28 * dasd_alias_disconnect_device_from_lcu will be called
29 * before the device is deleted.
30 * - The dasd_alias_add_device / dasd_alias_remove_device
31 * functions mark the point when a device is 'ready for service'.
32 * - A summary unit check is a rare occasion, but it is mandatory to
33 * support it. It requires some complex recovery actions before the
34 * devices can be used again (see dasd_alias_handle_summary_unit_check).
35 * - dasd_alias_get_start_dev will find an alias device that can be used
36 * instead of the base device and does some (very simple) load balancing.
37 * This is the function that gets called for each I/O, so when improving
38 * something, this function should get faster or better, the rest has just
43 static void summary_unit_check_handling_work(struct work_struct *);
44 static void lcu_update_work(struct work_struct *);
45 static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *);
47 static struct alias_root aliastree = {
48 .serverlist = LIST_HEAD_INIT(aliastree.serverlist),
49 .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock),
52 static struct alias_server *_find_server(struct dasd_uid *uid)
54 struct alias_server *pos;
55 list_for_each_entry(pos, &aliastree.serverlist, server) {
56 if (!strncmp(pos->uid.vendor, uid->vendor,
58 && !strncmp(pos->uid.serial, uid->serial,
65 static struct alias_lcu *_find_lcu(struct alias_server *server,
68 struct alias_lcu *pos;
69 list_for_each_entry(pos, &server->lculist, lcu) {
70 if (pos->uid.ssid == uid->ssid)
76 static struct alias_pav_group *_find_group(struct alias_lcu *lcu,
79 struct alias_pav_group *pos;
80 __u8 search_unit_addr;
82 /* for hyper pav there is only one group */
83 if (lcu->pav == HYPER_PAV) {
84 if (list_empty(&lcu->grouplist))
87 return list_first_entry(&lcu->grouplist,
88 struct alias_pav_group, group);
91 /* for base pav we have to find the group that matches the base */
92 if (uid->type == UA_BASE_DEVICE)
93 search_unit_addr = uid->real_unit_addr;
95 search_unit_addr = uid->base_unit_addr;
96 list_for_each_entry(pos, &lcu->grouplist, group) {
97 if (pos->uid.base_unit_addr == search_unit_addr &&
98 !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit)))
104 static struct alias_server *_allocate_server(struct dasd_uid *uid)
106 struct alias_server *server;
108 server = kzalloc(sizeof(*server), GFP_KERNEL);
110 return ERR_PTR(-ENOMEM);
111 memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor));
112 memcpy(server->uid.serial, uid->serial, sizeof(uid->serial));
113 INIT_LIST_HEAD(&server->server);
114 INIT_LIST_HEAD(&server->lculist);
118 static void _free_server(struct alias_server *server)
123 static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid)
125 struct alias_lcu *lcu;
127 lcu = kzalloc(sizeof(*lcu), GFP_KERNEL);
129 return ERR_PTR(-ENOMEM);
130 lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA);
133 lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA);
136 lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1),
137 GFP_KERNEL | GFP_DMA);
138 if (!lcu->rsu_cqr->cpaddr)
140 lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA);
141 if (!lcu->rsu_cqr->data)
144 memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor));
145 memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial));
146 lcu->uid.ssid = uid->ssid;
148 lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING;
149 INIT_LIST_HEAD(&lcu->lcu);
150 INIT_LIST_HEAD(&lcu->inactive_devices);
151 INIT_LIST_HEAD(&lcu->active_devices);
152 INIT_LIST_HEAD(&lcu->grouplist);
153 INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work);
154 INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work);
155 spin_lock_init(&lcu->lock);
156 init_completion(&lcu->lcu_setup);
160 kfree(lcu->rsu_cqr->cpaddr);
167 return ERR_PTR(-ENOMEM);
170 static void _free_lcu(struct alias_lcu *lcu)
172 kfree(lcu->rsu_cqr->data);
173 kfree(lcu->rsu_cqr->cpaddr);
180 * This is the function that will allocate all the server and lcu data,
181 * so this function must be called first for a new device.
182 * If the return value is 1, the lcu was already known before, if it
183 * is 0, this is a new lcu.
184 * Negative return code indicates that something went wrong (e.g. -ENOMEM)
186 int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
188 struct dasd_eckd_private *private;
190 struct alias_server *server, *newserver;
191 struct alias_lcu *lcu, *newlcu;
194 private = (struct dasd_eckd_private *) device->private;
196 device->discipline->get_uid(device, &uid);
197 spin_lock_irqsave(&aliastree.lock, flags);
198 server = _find_server(&uid);
200 spin_unlock_irqrestore(&aliastree.lock, flags);
201 newserver = _allocate_server(&uid);
202 if (IS_ERR(newserver))
203 return PTR_ERR(newserver);
204 spin_lock_irqsave(&aliastree.lock, flags);
205 server = _find_server(&uid);
207 list_add(&newserver->server, &aliastree.serverlist);
210 /* someone was faster */
211 _free_server(newserver);
215 lcu = _find_lcu(server, &uid);
217 spin_unlock_irqrestore(&aliastree.lock, flags);
218 newlcu = _allocate_lcu(&uid);
220 return PTR_ERR(newlcu);
221 spin_lock_irqsave(&aliastree.lock, flags);
222 lcu = _find_lcu(server, &uid);
224 list_add(&newlcu->lcu, &server->lculist);
227 /* someone was faster */
231 spin_lock(&lcu->lock);
232 list_add(&device->alias_list, &lcu->inactive_devices);
234 spin_unlock(&lcu->lock);
235 spin_unlock_irqrestore(&aliastree.lock, flags);
241 * This function removes a device from the scope of alias management.
242 * The complicated part is to make sure that it is not in use by
243 * any of the workers. If necessary cancel the work.
245 void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
247 struct dasd_eckd_private *private;
249 struct alias_lcu *lcu;
250 struct alias_server *server;
254 private = (struct dasd_eckd_private *) device->private;
256 /* nothing to do if already disconnected */
259 device->discipline->get_uid(device, &uid);
260 spin_lock_irqsave(&lcu->lock, flags);
261 list_del_init(&device->alias_list);
262 /* make sure that the workers don't use this device */
263 if (device == lcu->suc_data.device) {
264 spin_unlock_irqrestore(&lcu->lock, flags);
265 cancel_work_sync(&lcu->suc_data.worker);
266 spin_lock_irqsave(&lcu->lock, flags);
267 if (device == lcu->suc_data.device)
268 lcu->suc_data.device = NULL;
271 if (device == lcu->ruac_data.device) {
272 spin_unlock_irqrestore(&lcu->lock, flags);
274 cancel_delayed_work_sync(&lcu->ruac_data.dwork);
275 spin_lock_irqsave(&lcu->lock, flags);
276 if (device == lcu->ruac_data.device)
277 lcu->ruac_data.device = NULL;
280 spin_unlock_irqrestore(&lcu->lock, flags);
282 spin_lock_irqsave(&aliastree.lock, flags);
283 spin_lock(&lcu->lock);
284 if (list_empty(&lcu->grouplist) &&
285 list_empty(&lcu->active_devices) &&
286 list_empty(&lcu->inactive_devices)) {
288 spin_unlock(&lcu->lock);
293 _schedule_lcu_update(lcu, NULL);
294 spin_unlock(&lcu->lock);
296 server = _find_server(&uid);
297 if (server && list_empty(&server->lculist)) {
298 list_del(&server->server);
299 _free_server(server);
301 spin_unlock_irqrestore(&aliastree.lock, flags);
305 * This function assumes that the unit address configuration stored
306 * in the lcu is up to date and will update the device uid before
307 * adding it to a pav group.
310 static int _add_device_to_lcu(struct alias_lcu *lcu,
311 struct dasd_device *device,
312 struct dasd_device *pos)
315 struct dasd_eckd_private *private;
316 struct alias_pav_group *group;
320 private = (struct dasd_eckd_private *) device->private;
322 /* only lock if not already locked */
324 spin_lock_irqsave_nested(get_ccwdev_lock(device->cdev), flags,
326 private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type;
327 private->uid.base_unit_addr =
328 lcu->uac->unit[private->uid.real_unit_addr].base_ua;
332 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
334 /* if we have no PAV anyway, we don't need to bother with PAV groups */
335 if (lcu->pav == NO_PAV) {
336 list_move(&device->alias_list, &lcu->active_devices);
340 group = _find_group(lcu, &uid);
342 group = kzalloc(sizeof(*group), GFP_ATOMIC);
345 memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor));
346 memcpy(group->uid.serial, uid.serial, sizeof(uid.serial));
347 group->uid.ssid = uid.ssid;
348 if (uid.type == UA_BASE_DEVICE)
349 group->uid.base_unit_addr = uid.real_unit_addr;
351 group->uid.base_unit_addr = uid.base_unit_addr;
352 memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit));
353 INIT_LIST_HEAD(&group->group);
354 INIT_LIST_HEAD(&group->baselist);
355 INIT_LIST_HEAD(&group->aliaslist);
356 list_add(&group->group, &lcu->grouplist);
358 if (uid.type == UA_BASE_DEVICE)
359 list_move(&device->alias_list, &group->baselist);
361 list_move(&device->alias_list, &group->aliaslist);
362 private->pavgroup = group;
366 static void _remove_device_from_lcu(struct alias_lcu *lcu,
367 struct dasd_device *device)
369 struct dasd_eckd_private *private;
370 struct alias_pav_group *group;
372 private = (struct dasd_eckd_private *) device->private;
373 list_move(&device->alias_list, &lcu->inactive_devices);
374 group = private->pavgroup;
377 private->pavgroup = NULL;
378 if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) {
379 list_del(&group->group);
383 if (group->next == device)
387 static int read_unit_address_configuration(struct dasd_device *device,
388 struct alias_lcu *lcu)
390 struct dasd_psf_prssd_data *prssdp;
391 struct dasd_ccw_req *cqr;
396 cqr = dasd_kmalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
397 (sizeof(struct dasd_psf_prssd_data)),
401 cqr->startdev = device;
402 cqr->memdev = device;
403 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
405 cqr->expires = 20 * HZ;
407 /* Prepare for Read Subsystem Data */
408 prssdp = (struct dasd_psf_prssd_data *) cqr->data;
409 memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
410 prssdp->order = PSF_ORDER_PRSSD;
411 prssdp->suborder = 0x0e; /* Read unit address configuration */
412 /* all other bytes of prssdp must be zero */
415 ccw->cmd_code = DASD_ECKD_CCW_PSF;
416 ccw->count = sizeof(struct dasd_psf_prssd_data);
417 ccw->flags |= CCW_FLAG_CC;
418 ccw->cda = (__u32)(addr_t) prssdp;
420 /* Read Subsystem Data - feature codes */
421 memset(lcu->uac, 0, sizeof(*(lcu->uac)));
424 ccw->cmd_code = DASD_ECKD_CCW_RSSD;
425 ccw->count = sizeof(*(lcu->uac));
426 ccw->cda = (__u32)(addr_t) lcu->uac;
428 cqr->buildclk = get_clock();
429 cqr->status = DASD_CQR_FILLED;
431 /* need to unset flag here to detect race with summary unit check */
432 spin_lock_irqsave(&lcu->lock, flags);
433 lcu->flags &= ~NEED_UAC_UPDATE;
434 spin_unlock_irqrestore(&lcu->lock, flags);
437 rc = dasd_sleep_on(cqr);
438 } while (rc && (cqr->retries > 0));
440 spin_lock_irqsave(&lcu->lock, flags);
441 lcu->flags |= NEED_UAC_UPDATE;
442 spin_unlock_irqrestore(&lcu->lock, flags);
444 dasd_kfree_request(cqr, cqr->memdev);
448 static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
451 struct alias_pav_group *pavgroup, *tempgroup;
452 struct dasd_device *device, *tempdev;
454 struct dasd_eckd_private *private;
456 spin_lock_irqsave(&lcu->lock, flags);
457 list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) {
458 list_for_each_entry_safe(device, tempdev, &pavgroup->baselist,
460 list_move(&device->alias_list, &lcu->active_devices);
461 private = (struct dasd_eckd_private *) device->private;
462 private->pavgroup = NULL;
464 list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist,
466 list_move(&device->alias_list, &lcu->active_devices);
467 private = (struct dasd_eckd_private *) device->private;
468 private->pavgroup = NULL;
470 list_del(&pavgroup->group);
473 spin_unlock_irqrestore(&lcu->lock, flags);
475 rc = read_unit_address_configuration(refdev, lcu);
479 /* need to take cdev lock before lcu lock */
480 spin_lock_irqsave_nested(get_ccwdev_lock(refdev->cdev), flags,
482 spin_lock(&lcu->lock);
484 for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) {
485 switch (lcu->uac->unit[i].ua_type) {
486 case UA_BASE_PAV_ALIAS:
489 case UA_HYPER_PAV_ALIAS:
490 lcu->pav = HYPER_PAV;
493 if (lcu->pav != NO_PAV)
497 list_for_each_entry_safe(device, tempdev, &lcu->active_devices,
499 _add_device_to_lcu(lcu, device, refdev);
501 spin_unlock(&lcu->lock);
502 spin_unlock_irqrestore(get_ccwdev_lock(refdev->cdev), flags);
506 static void lcu_update_work(struct work_struct *work)
508 struct alias_lcu *lcu;
509 struct read_uac_work_data *ruac_data;
510 struct dasd_device *device;
514 ruac_data = container_of(work, struct read_uac_work_data, dwork.work);
515 lcu = container_of(ruac_data, struct alias_lcu, ruac_data);
516 device = ruac_data->device;
517 rc = _lcu_update(device, lcu);
519 * Need to check flags again, as there could have been another
520 * prepare_update or a new device a new device while we were still
521 * processing the data
523 spin_lock_irqsave(&lcu->lock, flags);
524 if (rc || (lcu->flags & NEED_UAC_UPDATE)) {
525 DBF_DEV_EVENT(DBF_WARNING, device, "could not update"
526 " alias data in lcu (rc = %d), retry later", rc);
527 schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ);
529 lcu->ruac_data.device = NULL;
530 lcu->flags &= ~UPDATE_PENDING;
532 spin_unlock_irqrestore(&lcu->lock, flags);
535 static int _schedule_lcu_update(struct alias_lcu *lcu,
536 struct dasd_device *device)
538 struct dasd_device *usedev = NULL;
539 struct alias_pav_group *group;
541 lcu->flags |= NEED_UAC_UPDATE;
542 if (lcu->ruac_data.device) {
543 /* already scheduled or running */
546 if (device && !list_empty(&device->alias_list))
549 if (!usedev && !list_empty(&lcu->grouplist)) {
550 group = list_first_entry(&lcu->grouplist,
551 struct alias_pav_group, group);
552 if (!list_empty(&group->baselist))
553 usedev = list_first_entry(&group->baselist,
556 else if (!list_empty(&group->aliaslist))
557 usedev = list_first_entry(&group->aliaslist,
561 if (!usedev && !list_empty(&lcu->active_devices)) {
562 usedev = list_first_entry(&lcu->active_devices,
563 struct dasd_device, alias_list);
566 * if we haven't found a proper device yet, give up for now, the next
567 * device that will be set active will trigger an lcu update
571 lcu->ruac_data.device = usedev;
572 schedule_delayed_work(&lcu->ruac_data.dwork, 0);
576 int dasd_alias_add_device(struct dasd_device *device)
578 struct dasd_eckd_private *private;
579 struct alias_lcu *lcu;
583 private = (struct dasd_eckd_private *) device->private;
587 /* need to take cdev lock before lcu lock */
588 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
589 spin_lock(&lcu->lock);
590 if (!(lcu->flags & UPDATE_PENDING)) {
591 rc = _add_device_to_lcu(lcu, device, device);
593 lcu->flags |= UPDATE_PENDING;
595 if (lcu->flags & UPDATE_PENDING) {
596 list_move(&device->alias_list, &lcu->active_devices);
597 _schedule_lcu_update(lcu, device);
599 spin_unlock(&lcu->lock);
600 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
604 int dasd_alias_update_add_device(struct dasd_device *device)
606 struct dasd_eckd_private *private;
607 private = (struct dasd_eckd_private *) device->private;
608 private->lcu->flags |= UPDATE_PENDING;
609 return dasd_alias_add_device(device);
612 int dasd_alias_remove_device(struct dasd_device *device)
614 struct dasd_eckd_private *private;
615 struct alias_lcu *lcu;
618 private = (struct dasd_eckd_private *) device->private;
620 /* nothing to do if already removed */
623 spin_lock_irqsave(&lcu->lock, flags);
624 _remove_device_from_lcu(lcu, device);
625 spin_unlock_irqrestore(&lcu->lock, flags);
629 struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device)
632 struct dasd_device *alias_device;
633 struct alias_pav_group *group;
634 struct alias_lcu *lcu;
635 struct dasd_eckd_private *private, *alias_priv;
638 private = (struct dasd_eckd_private *) base_device->private;
639 group = private->pavgroup;
643 if (lcu->pav == NO_PAV ||
644 lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING))
646 if (unlikely(!(private->features.feature[8] & 0x01))) {
648 * PAV enabled but prefix not, very unlikely
649 * seems to be a lost pathgroup
650 * use base device to do IO
652 DBF_DEV_EVENT(DBF_ERR, base_device, "%s",
653 "Prefix not enabled with PAV enabled\n");
657 spin_lock_irqsave(&lcu->lock, flags);
658 alias_device = group->next;
660 if (list_empty(&group->aliaslist)) {
661 spin_unlock_irqrestore(&lcu->lock, flags);
664 alias_device = list_first_entry(&group->aliaslist,
669 if (list_is_last(&alias_device->alias_list, &group->aliaslist))
670 group->next = list_first_entry(&group->aliaslist,
671 struct dasd_device, alias_list);
673 group->next = list_first_entry(&alias_device->alias_list,
674 struct dasd_device, alias_list);
675 spin_unlock_irqrestore(&lcu->lock, flags);
676 alias_priv = (struct dasd_eckd_private *) alias_device->private;
677 if ((alias_priv->count < private->count) && !alias_device->stopped)
684 * Summary unit check handling depends on the way alias devices
685 * are handled so it is done here rather then in dasd_eckd.c
687 static int reset_summary_unit_check(struct alias_lcu *lcu,
688 struct dasd_device *device,
691 struct dasd_ccw_req *cqr;
696 strncpy((char *) &cqr->magic, "ECKD", 4);
697 ASCEBC((char *) &cqr->magic, 4);
699 ccw->cmd_code = DASD_ECKD_CCW_RSCK;
702 ccw->cda = (__u32)(addr_t) cqr->data;
703 ((char *)cqr->data)[0] = reason;
705 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
706 cqr->retries = 255; /* set retry counter to enable basic ERP */
707 cqr->startdev = device;
708 cqr->memdev = device;
710 cqr->expires = 5 * HZ;
711 cqr->buildclk = get_clock();
712 cqr->status = DASD_CQR_FILLED;
714 rc = dasd_sleep_on_immediatly(cqr);
718 static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu)
720 struct alias_pav_group *pavgroup;
721 struct dasd_device *device;
722 struct dasd_eckd_private *private;
725 /* active and inactive list can contain alias as well as base devices */
726 list_for_each_entry(device, &lcu->active_devices, alias_list) {
727 private = (struct dasd_eckd_private *) device->private;
728 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
729 if (private->uid.type != UA_BASE_DEVICE) {
730 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
734 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
735 dasd_schedule_block_bh(device->block);
736 dasd_schedule_device_bh(device);
738 list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
739 private = (struct dasd_eckd_private *) device->private;
740 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
741 if (private->uid.type != UA_BASE_DEVICE) {
742 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
746 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
747 dasd_schedule_block_bh(device->block);
748 dasd_schedule_device_bh(device);
750 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
751 list_for_each_entry(device, &pavgroup->baselist, alias_list) {
752 dasd_schedule_block_bh(device->block);
753 dasd_schedule_device_bh(device);
758 static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu)
760 struct alias_pav_group *pavgroup;
761 struct dasd_device *device, *temp;
762 struct dasd_eckd_private *private;
768 * Problem here ist that dasd_flush_device_queue may wait
769 * for termination of a request to complete. We can't keep
770 * the lcu lock during that time, so we must assume that
771 * the lists may have changed.
772 * Idea: first gather all active alias devices in a separate list,
773 * then flush the first element of this list unlocked, and afterwards
774 * check if it is still on the list before moving it to the
775 * active_devices list.
778 spin_lock_irqsave(&lcu->lock, flags);
779 list_for_each_entry_safe(device, temp, &lcu->active_devices,
781 private = (struct dasd_eckd_private *) device->private;
782 if (private->uid.type == UA_BASE_DEVICE)
784 list_move(&device->alias_list, &active);
787 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
788 list_splice_init(&pavgroup->aliaslist, &active);
790 while (!list_empty(&active)) {
791 device = list_first_entry(&active, struct dasd_device,
793 spin_unlock_irqrestore(&lcu->lock, flags);
794 rc = dasd_flush_device_queue(device);
795 spin_lock_irqsave(&lcu->lock, flags);
797 * only move device around if it wasn't moved away while we
798 * were waiting for the flush
800 if (device == list_first_entry(&active,
801 struct dasd_device, alias_list))
802 list_move(&device->alias_list, &lcu->active_devices);
804 spin_unlock_irqrestore(&lcu->lock, flags);
807 static void __stop_device_on_lcu(struct dasd_device *device,
808 struct dasd_device *pos)
810 /* If pos == device then device is already locked! */
812 dasd_device_set_stop_bits(pos, DASD_STOPPED_SU);
815 spin_lock(get_ccwdev_lock(pos->cdev));
816 dasd_device_set_stop_bits(pos, DASD_STOPPED_SU);
817 spin_unlock(get_ccwdev_lock(pos->cdev));
821 * This function is called in interrupt context, so the
822 * cdev lock for device is already locked!
824 static void _stop_all_devices_on_lcu(struct alias_lcu *lcu,
825 struct dasd_device *device)
827 struct alias_pav_group *pavgroup;
828 struct dasd_device *pos;
830 list_for_each_entry(pos, &lcu->active_devices, alias_list)
831 __stop_device_on_lcu(device, pos);
832 list_for_each_entry(pos, &lcu->inactive_devices, alias_list)
833 __stop_device_on_lcu(device, pos);
834 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
835 list_for_each_entry(pos, &pavgroup->baselist, alias_list)
836 __stop_device_on_lcu(device, pos);
837 list_for_each_entry(pos, &pavgroup->aliaslist, alias_list)
838 __stop_device_on_lcu(device, pos);
842 static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu)
844 struct alias_pav_group *pavgroup;
845 struct dasd_device *device;
848 list_for_each_entry(device, &lcu->active_devices, alias_list) {
849 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
850 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
851 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
854 list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
855 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
856 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
857 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
860 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
861 list_for_each_entry(device, &pavgroup->baselist, alias_list) {
862 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
863 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
864 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
867 list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
868 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
869 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
870 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
876 static void summary_unit_check_handling_work(struct work_struct *work)
878 struct alias_lcu *lcu;
879 struct summary_unit_check_work_data *suc_data;
881 struct dasd_device *device;
883 suc_data = container_of(work, struct summary_unit_check_work_data,
885 lcu = container_of(suc_data, struct alias_lcu, suc_data);
886 device = suc_data->device;
888 /* 1. flush alias devices */
889 flush_all_alias_devices_on_lcu(lcu);
891 /* 2. reset summary unit check */
892 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
893 dasd_device_remove_stop_bits(device,
894 (DASD_STOPPED_SU | DASD_STOPPED_PENDING));
895 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
896 reset_summary_unit_check(lcu, device, suc_data->reason);
898 spin_lock_irqsave(&lcu->lock, flags);
899 _unstop_all_devices_on_lcu(lcu);
900 _restart_all_base_devices_on_lcu(lcu);
901 /* 3. read new alias configuration */
902 _schedule_lcu_update(lcu, device);
903 lcu->suc_data.device = NULL;
904 spin_unlock_irqrestore(&lcu->lock, flags);
908 * note: this will be called from int handler context (cdev locked)
910 void dasd_alias_handle_summary_unit_check(struct dasd_device *device,
913 struct alias_lcu *lcu;
915 struct dasd_eckd_private *private;
918 private = (struct dasd_eckd_private *) device->private;
920 sense = dasd_get_sense(irb);
923 DBF_DEV_EVENT(DBF_NOTICE, device, "%s %x",
924 "eckd handle summary unit check: reason", reason);
926 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
927 "eckd handle summary unit check:"
928 " no reason code available");
934 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
935 "device not ready to handle summary"
936 " unit check (no lcu structure)");
939 spin_lock(&lcu->lock);
940 _stop_all_devices_on_lcu(lcu, device);
941 /* prepare for lcu_update */
942 private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING;
943 /* If this device is about to be removed just return and wait for
944 * the next interrupt on a different device
946 if (list_empty(&device->alias_list)) {
947 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
948 "device is in offline processing,"
949 " don't do summary unit check handling");
950 spin_unlock(&lcu->lock);
953 if (lcu->suc_data.device) {
954 /* already scheduled or running */
955 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
956 "previous instance of summary unit check worker"
958 spin_unlock(&lcu->lock);
961 lcu->suc_data.reason = reason;
962 lcu->suc_data.device = device;
963 spin_unlock(&lcu->lock);
964 schedule_work(&lcu->suc_data.worker);