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 = device
->private;
190 struct alias_server
*server
, *newserver
;
191 struct alias_lcu
*lcu
, *newlcu
;
194 device
->discipline
->get_uid(device
, &uid
);
195 spin_lock_irqsave(&aliastree
.lock
, flags
);
196 server
= _find_server(&uid
);
198 spin_unlock_irqrestore(&aliastree
.lock
, flags
);
199 newserver
= _allocate_server(&uid
);
200 if (IS_ERR(newserver
))
201 return PTR_ERR(newserver
);
202 spin_lock_irqsave(&aliastree
.lock
, flags
);
203 server
= _find_server(&uid
);
205 list_add(&newserver
->server
, &aliastree
.serverlist
);
208 /* someone was faster */
209 _free_server(newserver
);
213 lcu
= _find_lcu(server
, &uid
);
215 spin_unlock_irqrestore(&aliastree
.lock
, flags
);
216 newlcu
= _allocate_lcu(&uid
);
218 return PTR_ERR(newlcu
);
219 spin_lock_irqsave(&aliastree
.lock
, flags
);
220 lcu
= _find_lcu(server
, &uid
);
222 list_add(&newlcu
->lcu
, &server
->lculist
);
225 /* someone was faster */
229 spin_lock(&lcu
->lock
);
230 list_add(&device
->alias_list
, &lcu
->inactive_devices
);
232 spin_unlock(&lcu
->lock
);
233 spin_unlock_irqrestore(&aliastree
.lock
, flags
);
239 * This function removes a device from the scope of alias management.
240 * The complicated part is to make sure that it is not in use by
241 * any of the workers. If necessary cancel the work.
243 void dasd_alias_disconnect_device_from_lcu(struct dasd_device
*device
)
245 struct dasd_eckd_private
*private = device
->private;
247 struct alias_lcu
*lcu
;
248 struct alias_server
*server
;
253 /* nothing to do if already disconnected */
256 device
->discipline
->get_uid(device
, &uid
);
257 spin_lock_irqsave(&lcu
->lock
, flags
);
258 list_del_init(&device
->alias_list
);
259 /* make sure that the workers don't use this device */
260 if (device
== lcu
->suc_data
.device
) {
261 spin_unlock_irqrestore(&lcu
->lock
, flags
);
262 cancel_work_sync(&lcu
->suc_data
.worker
);
263 spin_lock_irqsave(&lcu
->lock
, flags
);
264 if (device
== lcu
->suc_data
.device
) {
265 dasd_put_device(device
);
266 lcu
->suc_data
.device
= NULL
;
270 if (device
== lcu
->ruac_data
.device
) {
271 spin_unlock_irqrestore(&lcu
->lock
, flags
);
273 cancel_delayed_work_sync(&lcu
->ruac_data
.dwork
);
274 spin_lock_irqsave(&lcu
->lock
, flags
);
275 if (device
== lcu
->ruac_data
.device
) {
276 dasd_put_device(device
);
277 lcu
->ruac_data
.device
= NULL
;
281 spin_unlock_irqrestore(&lcu
->lock
, flags
);
283 spin_lock_irqsave(&aliastree
.lock
, flags
);
284 spin_lock(&lcu
->lock
);
285 if (list_empty(&lcu
->grouplist
) &&
286 list_empty(&lcu
->active_devices
) &&
287 list_empty(&lcu
->inactive_devices
)) {
289 spin_unlock(&lcu
->lock
);
294 _schedule_lcu_update(lcu
, NULL
);
295 spin_unlock(&lcu
->lock
);
297 server
= _find_server(&uid
);
298 if (server
&& list_empty(&server
->lculist
)) {
299 list_del(&server
->server
);
300 _free_server(server
);
302 spin_unlock_irqrestore(&aliastree
.lock
, flags
);
306 * This function assumes that the unit address configuration stored
307 * in the lcu is up to date and will update the device uid before
308 * adding it to a pav group.
311 static int _add_device_to_lcu(struct alias_lcu
*lcu
,
312 struct dasd_device
*device
,
313 struct dasd_device
*pos
)
316 struct dasd_eckd_private
*private = device
->private;
317 struct alias_pav_group
*group
;
320 private->uid
.type
= lcu
->uac
->unit
[private->uid
.real_unit_addr
].ua_type
;
321 private->uid
.base_unit_addr
=
322 lcu
->uac
->unit
[private->uid
.real_unit_addr
].base_ua
;
325 /* if we have no PAV anyway, we don't need to bother with PAV groups */
326 if (lcu
->pav
== NO_PAV
) {
327 list_move(&device
->alias_list
, &lcu
->active_devices
);
331 group
= _find_group(lcu
, &uid
);
333 group
= kzalloc(sizeof(*group
), GFP_ATOMIC
);
336 memcpy(group
->uid
.vendor
, uid
.vendor
, sizeof(uid
.vendor
));
337 memcpy(group
->uid
.serial
, uid
.serial
, sizeof(uid
.serial
));
338 group
->uid
.ssid
= uid
.ssid
;
339 if (uid
.type
== UA_BASE_DEVICE
)
340 group
->uid
.base_unit_addr
= uid
.real_unit_addr
;
342 group
->uid
.base_unit_addr
= uid
.base_unit_addr
;
343 memcpy(group
->uid
.vduit
, uid
.vduit
, sizeof(uid
.vduit
));
344 INIT_LIST_HEAD(&group
->group
);
345 INIT_LIST_HEAD(&group
->baselist
);
346 INIT_LIST_HEAD(&group
->aliaslist
);
347 list_add(&group
->group
, &lcu
->grouplist
);
349 if (uid
.type
== UA_BASE_DEVICE
)
350 list_move(&device
->alias_list
, &group
->baselist
);
352 list_move(&device
->alias_list
, &group
->aliaslist
);
353 private->pavgroup
= group
;
357 static void _remove_device_from_lcu(struct alias_lcu
*lcu
,
358 struct dasd_device
*device
)
360 struct dasd_eckd_private
*private = device
->private;
361 struct alias_pav_group
*group
;
363 list_move(&device
->alias_list
, &lcu
->inactive_devices
);
364 group
= private->pavgroup
;
367 private->pavgroup
= NULL
;
368 if (list_empty(&group
->baselist
) && list_empty(&group
->aliaslist
)) {
369 list_del(&group
->group
);
373 if (group
->next
== device
)
378 suborder_not_supported(struct dasd_ccw_req
*cqr
)
385 sense
= dasd_get_sense(&cqr
->irb
);
390 msg_format
= (sense
[7] & 0xF0);
391 msg_no
= (sense
[7] & 0x0F);
393 /* command reject, Format 0 MSG 4 - invalid parameter */
394 if ((reason
== 0x80) && (msg_format
== 0x00) && (msg_no
== 0x04))
401 * This function tries to lock all devices on an lcu via trylock
402 * return NULL on success otherwise return first failed device
404 static struct dasd_device
*_trylock_all_devices_on_lcu(struct alias_lcu
*lcu
,
405 struct dasd_device
*pos
)
408 struct alias_pav_group
*pavgroup
;
409 struct dasd_device
*device
;
411 list_for_each_entry(device
, &lcu
->active_devices
, alias_list
) {
414 if (!spin_trylock(get_ccwdev_lock(device
->cdev
)))
417 list_for_each_entry(device
, &lcu
->inactive_devices
, alias_list
) {
420 if (!spin_trylock(get_ccwdev_lock(device
->cdev
)))
423 list_for_each_entry(pavgroup
, &lcu
->grouplist
, group
) {
424 list_for_each_entry(device
, &pavgroup
->baselist
, alias_list
) {
427 if (!spin_trylock(get_ccwdev_lock(device
->cdev
)))
430 list_for_each_entry(device
, &pavgroup
->aliaslist
, alias_list
) {
433 if (!spin_trylock(get_ccwdev_lock(device
->cdev
)))
441 * unlock all devices except the one that is specified as pos
442 * stop if enddev is specified and reached
444 static void _unlock_all_devices_on_lcu(struct alias_lcu
*lcu
,
445 struct dasd_device
*pos
,
446 struct dasd_device
*enddev
)
449 struct alias_pav_group
*pavgroup
;
450 struct dasd_device
*device
;
452 list_for_each_entry(device
, &lcu
->active_devices
, alias_list
) {
455 if (device
== enddev
)
457 spin_unlock(get_ccwdev_lock(device
->cdev
));
459 list_for_each_entry(device
, &lcu
->inactive_devices
, alias_list
) {
462 if (device
== enddev
)
464 spin_unlock(get_ccwdev_lock(device
->cdev
));
466 list_for_each_entry(pavgroup
, &lcu
->grouplist
, group
) {
467 list_for_each_entry(device
, &pavgroup
->baselist
, alias_list
) {
470 if (device
== enddev
)
472 spin_unlock(get_ccwdev_lock(device
->cdev
));
474 list_for_each_entry(device
, &pavgroup
->aliaslist
, alias_list
) {
477 if (device
== enddev
)
479 spin_unlock(get_ccwdev_lock(device
->cdev
));
485 * this function is needed because the locking order
486 * device lock -> lcu lock
487 * needs to be assured when iterating over devices in an LCU
489 * if a device is specified in pos then the device lock is already hold
491 static void _trylock_and_lock_lcu_irqsave(struct alias_lcu
*lcu
,
492 struct dasd_device
*pos
,
493 unsigned long *flags
)
495 struct dasd_device
*failed
;
498 spin_lock_irqsave(&lcu
->lock
, *flags
);
499 failed
= _trylock_all_devices_on_lcu(lcu
, pos
);
501 _unlock_all_devices_on_lcu(lcu
, pos
, failed
);
502 spin_unlock_irqrestore(&lcu
->lock
, *flags
);
508 static void _trylock_and_lock_lcu(struct alias_lcu
*lcu
,
509 struct dasd_device
*pos
)
511 struct dasd_device
*failed
;
514 spin_lock(&lcu
->lock
);
515 failed
= _trylock_all_devices_on_lcu(lcu
, pos
);
517 _unlock_all_devices_on_lcu(lcu
, pos
, failed
);
518 spin_unlock(&lcu
->lock
);
524 static int read_unit_address_configuration(struct dasd_device
*device
,
525 struct alias_lcu
*lcu
)
527 struct dasd_psf_prssd_data
*prssdp
;
528 struct dasd_ccw_req
*cqr
;
533 cqr
= dasd_kmalloc_request(DASD_ECKD_MAGIC
, 1 /* PSF */ + 1 /* RSSD */,
534 (sizeof(struct dasd_psf_prssd_data
)),
538 cqr
->startdev
= device
;
539 cqr
->memdev
= device
;
540 clear_bit(DASD_CQR_FLAGS_USE_ERP
, &cqr
->flags
);
542 cqr
->expires
= 20 * HZ
;
544 /* Prepare for Read Subsystem Data */
545 prssdp
= (struct dasd_psf_prssd_data
*) cqr
->data
;
546 memset(prssdp
, 0, sizeof(struct dasd_psf_prssd_data
));
547 prssdp
->order
= PSF_ORDER_PRSSD
;
548 prssdp
->suborder
= 0x0e; /* Read unit address configuration */
549 /* all other bytes of prssdp must be zero */
552 ccw
->cmd_code
= DASD_ECKD_CCW_PSF
;
553 ccw
->count
= sizeof(struct dasd_psf_prssd_data
);
554 ccw
->flags
|= CCW_FLAG_CC
;
555 ccw
->cda
= (__u32
)(addr_t
) prssdp
;
557 /* Read Subsystem Data - feature codes */
558 memset(lcu
->uac
, 0, sizeof(*(lcu
->uac
)));
561 ccw
->cmd_code
= DASD_ECKD_CCW_RSSD
;
562 ccw
->count
= sizeof(*(lcu
->uac
));
563 ccw
->cda
= (__u32
)(addr_t
) lcu
->uac
;
565 cqr
->buildclk
= get_tod_clock();
566 cqr
->status
= DASD_CQR_FILLED
;
568 /* need to unset flag here to detect race with summary unit check */
569 spin_lock_irqsave(&lcu
->lock
, flags
);
570 lcu
->flags
&= ~NEED_UAC_UPDATE
;
571 spin_unlock_irqrestore(&lcu
->lock
, flags
);
574 rc
= dasd_sleep_on(cqr
);
575 if (rc
&& suborder_not_supported(cqr
))
577 } while (rc
&& (cqr
->retries
> 0));
579 spin_lock_irqsave(&lcu
->lock
, flags
);
580 lcu
->flags
|= NEED_UAC_UPDATE
;
581 spin_unlock_irqrestore(&lcu
->lock
, flags
);
583 dasd_kfree_request(cqr
, cqr
->memdev
);
587 static int _lcu_update(struct dasd_device
*refdev
, struct alias_lcu
*lcu
)
590 struct alias_pav_group
*pavgroup
, *tempgroup
;
591 struct dasd_device
*device
, *tempdev
;
593 struct dasd_eckd_private
*private;
595 spin_lock_irqsave(&lcu
->lock
, flags
);
596 list_for_each_entry_safe(pavgroup
, tempgroup
, &lcu
->grouplist
, group
) {
597 list_for_each_entry_safe(device
, tempdev
, &pavgroup
->baselist
,
599 list_move(&device
->alias_list
, &lcu
->active_devices
);
600 private = device
->private;
601 private->pavgroup
= NULL
;
603 list_for_each_entry_safe(device
, tempdev
, &pavgroup
->aliaslist
,
605 list_move(&device
->alias_list
, &lcu
->active_devices
);
606 private = device
->private;
607 private->pavgroup
= NULL
;
609 list_del(&pavgroup
->group
);
612 spin_unlock_irqrestore(&lcu
->lock
, flags
);
614 rc
= read_unit_address_configuration(refdev
, lcu
);
618 _trylock_and_lock_lcu_irqsave(lcu
, NULL
, &flags
);
620 for (i
= 0; i
< MAX_DEVICES_PER_LCU
; ++i
) {
621 switch (lcu
->uac
->unit
[i
].ua_type
) {
622 case UA_BASE_PAV_ALIAS
:
625 case UA_HYPER_PAV_ALIAS
:
626 lcu
->pav
= HYPER_PAV
;
629 if (lcu
->pav
!= NO_PAV
)
633 list_for_each_entry_safe(device
, tempdev
, &lcu
->active_devices
,
635 _add_device_to_lcu(lcu
, device
, refdev
);
637 _unlock_all_devices_on_lcu(lcu
, NULL
, NULL
);
638 spin_unlock_irqrestore(&lcu
->lock
, flags
);
642 static void lcu_update_work(struct work_struct
*work
)
644 struct alias_lcu
*lcu
;
645 struct read_uac_work_data
*ruac_data
;
646 struct dasd_device
*device
;
650 ruac_data
= container_of(work
, struct read_uac_work_data
, dwork
.work
);
651 lcu
= container_of(ruac_data
, struct alias_lcu
, ruac_data
);
652 device
= ruac_data
->device
;
653 rc
= _lcu_update(device
, lcu
);
655 * Need to check flags again, as there could have been another
656 * prepare_update or a new device a new device while we were still
657 * processing the data
659 spin_lock_irqsave(&lcu
->lock
, flags
);
660 if ((rc
&& (rc
!= -EOPNOTSUPP
)) || (lcu
->flags
& NEED_UAC_UPDATE
)) {
661 DBF_DEV_EVENT(DBF_WARNING
, device
, "could not update"
662 " alias data in lcu (rc = %d), retry later", rc
);
663 if (!schedule_delayed_work(&lcu
->ruac_data
.dwork
, 30*HZ
))
664 dasd_put_device(device
);
666 dasd_put_device(device
);
667 lcu
->ruac_data
.device
= NULL
;
668 lcu
->flags
&= ~UPDATE_PENDING
;
670 spin_unlock_irqrestore(&lcu
->lock
, flags
);
673 static int _schedule_lcu_update(struct alias_lcu
*lcu
,
674 struct dasd_device
*device
)
676 struct dasd_device
*usedev
= NULL
;
677 struct alias_pav_group
*group
;
679 lcu
->flags
|= NEED_UAC_UPDATE
;
680 if (lcu
->ruac_data
.device
) {
681 /* already scheduled or running */
684 if (device
&& !list_empty(&device
->alias_list
))
687 if (!usedev
&& !list_empty(&lcu
->grouplist
)) {
688 group
= list_first_entry(&lcu
->grouplist
,
689 struct alias_pav_group
, group
);
690 if (!list_empty(&group
->baselist
))
691 usedev
= list_first_entry(&group
->baselist
,
694 else if (!list_empty(&group
->aliaslist
))
695 usedev
= list_first_entry(&group
->aliaslist
,
699 if (!usedev
&& !list_empty(&lcu
->active_devices
)) {
700 usedev
= list_first_entry(&lcu
->active_devices
,
701 struct dasd_device
, alias_list
);
704 * if we haven't found a proper device yet, give up for now, the next
705 * device that will be set active will trigger an lcu update
709 dasd_get_device(usedev
);
710 lcu
->ruac_data
.device
= usedev
;
711 if (!schedule_delayed_work(&lcu
->ruac_data
.dwork
, 0))
712 dasd_put_device(usedev
);
716 int dasd_alias_add_device(struct dasd_device
*device
)
718 struct dasd_eckd_private
*private = device
->private;
719 struct alias_lcu
*lcu
;
725 spin_lock_irqsave(get_ccwdev_lock(device
->cdev
), flags
);
726 spin_lock(&lcu
->lock
);
727 if (!(lcu
->flags
& UPDATE_PENDING
)) {
728 rc
= _add_device_to_lcu(lcu
, device
, device
);
730 lcu
->flags
|= UPDATE_PENDING
;
732 if (lcu
->flags
& UPDATE_PENDING
) {
733 list_move(&device
->alias_list
, &lcu
->active_devices
);
734 _schedule_lcu_update(lcu
, device
);
736 spin_unlock(&lcu
->lock
);
737 spin_unlock_irqrestore(get_ccwdev_lock(device
->cdev
), flags
);
741 int dasd_alias_update_add_device(struct dasd_device
*device
)
743 struct dasd_eckd_private
*private = device
->private;
745 private->lcu
->flags
|= UPDATE_PENDING
;
746 return dasd_alias_add_device(device
);
749 int dasd_alias_remove_device(struct dasd_device
*device
)
751 struct dasd_eckd_private
*private = device
->private;
752 struct alias_lcu
*lcu
= private->lcu
;
755 /* nothing to do if already removed */
758 spin_lock_irqsave(&lcu
->lock
, flags
);
759 _remove_device_from_lcu(lcu
, device
);
760 spin_unlock_irqrestore(&lcu
->lock
, flags
);
764 struct dasd_device
*dasd_alias_get_start_dev(struct dasd_device
*base_device
)
766 struct dasd_eckd_private
*alias_priv
, *private = base_device
->private;
767 struct alias_pav_group
*group
= private->pavgroup
;
768 struct alias_lcu
*lcu
= private->lcu
;
769 struct dasd_device
*alias_device
;
774 if (lcu
->pav
== NO_PAV
||
775 lcu
->flags
& (NEED_UAC_UPDATE
| UPDATE_PENDING
))
777 if (unlikely(!(private->features
.feature
[8] & 0x01))) {
779 * PAV enabled but prefix not, very unlikely
780 * seems to be a lost pathgroup
781 * use base device to do IO
783 DBF_DEV_EVENT(DBF_ERR
, base_device
, "%s",
784 "Prefix not enabled with PAV enabled\n");
788 spin_lock_irqsave(&lcu
->lock
, flags
);
789 alias_device
= group
->next
;
791 if (list_empty(&group
->aliaslist
)) {
792 spin_unlock_irqrestore(&lcu
->lock
, flags
);
795 alias_device
= list_first_entry(&group
->aliaslist
,
800 if (list_is_last(&alias_device
->alias_list
, &group
->aliaslist
))
801 group
->next
= list_first_entry(&group
->aliaslist
,
802 struct dasd_device
, alias_list
);
804 group
->next
= list_first_entry(&alias_device
->alias_list
,
805 struct dasd_device
, alias_list
);
806 spin_unlock_irqrestore(&lcu
->lock
, flags
);
807 alias_priv
= alias_device
->private;
808 if ((alias_priv
->count
< private->count
) && !alias_device
->stopped
&&
809 !test_bit(DASD_FLAG_OFFLINE
, &alias_device
->flags
))
816 * Summary unit check handling depends on the way alias devices
817 * are handled so it is done here rather then in dasd_eckd.c
819 static int reset_summary_unit_check(struct alias_lcu
*lcu
,
820 struct dasd_device
*device
,
823 struct dasd_ccw_req
*cqr
;
828 strncpy((char *) &cqr
->magic
, "ECKD", 4);
829 ASCEBC((char *) &cqr
->magic
, 4);
831 ccw
->cmd_code
= DASD_ECKD_CCW_RSCK
;
832 ccw
->flags
= CCW_FLAG_SLI
;
834 ccw
->cda
= (__u32
)(addr_t
) cqr
->data
;
835 ((char *)cqr
->data
)[0] = reason
;
837 clear_bit(DASD_CQR_FLAGS_USE_ERP
, &cqr
->flags
);
838 cqr
->retries
= 255; /* set retry counter to enable basic ERP */
839 cqr
->startdev
= device
;
840 cqr
->memdev
= device
;
842 cqr
->expires
= 5 * HZ
;
843 cqr
->buildclk
= get_tod_clock();
844 cqr
->status
= DASD_CQR_FILLED
;
846 rc
= dasd_sleep_on_immediatly(cqr
);
850 static void _restart_all_base_devices_on_lcu(struct alias_lcu
*lcu
)
852 struct alias_pav_group
*pavgroup
;
853 struct dasd_device
*device
;
854 struct dasd_eckd_private
*private;
856 /* active and inactive list can contain alias as well as base devices */
857 list_for_each_entry(device
, &lcu
->active_devices
, alias_list
) {
858 private = device
->private;
859 if (private->uid
.type
!= UA_BASE_DEVICE
)
861 dasd_schedule_block_bh(device
->block
);
862 dasd_schedule_device_bh(device
);
864 list_for_each_entry(device
, &lcu
->inactive_devices
, alias_list
) {
865 private = device
->private;
866 if (private->uid
.type
!= UA_BASE_DEVICE
)
868 dasd_schedule_block_bh(device
->block
);
869 dasd_schedule_device_bh(device
);
871 list_for_each_entry(pavgroup
, &lcu
->grouplist
, group
) {
872 list_for_each_entry(device
, &pavgroup
->baselist
, alias_list
) {
873 dasd_schedule_block_bh(device
->block
);
874 dasd_schedule_device_bh(device
);
879 static void flush_all_alias_devices_on_lcu(struct alias_lcu
*lcu
)
881 struct alias_pav_group
*pavgroup
;
882 struct dasd_device
*device
, *temp
;
883 struct dasd_eckd_private
*private;
889 * Problem here ist that dasd_flush_device_queue may wait
890 * for termination of a request to complete. We can't keep
891 * the lcu lock during that time, so we must assume that
892 * the lists may have changed.
893 * Idea: first gather all active alias devices in a separate list,
894 * then flush the first element of this list unlocked, and afterwards
895 * check if it is still on the list before moving it to the
896 * active_devices list.
899 spin_lock_irqsave(&lcu
->lock
, flags
);
900 list_for_each_entry_safe(device
, temp
, &lcu
->active_devices
,
902 private = device
->private;
903 if (private->uid
.type
== UA_BASE_DEVICE
)
905 list_move(&device
->alias_list
, &active
);
908 list_for_each_entry(pavgroup
, &lcu
->grouplist
, group
) {
909 list_splice_init(&pavgroup
->aliaslist
, &active
);
911 while (!list_empty(&active
)) {
912 device
= list_first_entry(&active
, struct dasd_device
,
914 spin_unlock_irqrestore(&lcu
->lock
, flags
);
915 rc
= dasd_flush_device_queue(device
);
916 spin_lock_irqsave(&lcu
->lock
, flags
);
918 * only move device around if it wasn't moved away while we
919 * were waiting for the flush
921 if (device
== list_first_entry(&active
,
922 struct dasd_device
, alias_list
)) {
923 list_move(&device
->alias_list
, &lcu
->active_devices
);
924 private = device
->private;
925 private->pavgroup
= NULL
;
928 spin_unlock_irqrestore(&lcu
->lock
, flags
);
931 static void _stop_all_devices_on_lcu(struct alias_lcu
*lcu
)
933 struct alias_pav_group
*pavgroup
;
934 struct dasd_device
*device
;
936 list_for_each_entry(device
, &lcu
->active_devices
, alias_list
)
937 dasd_device_set_stop_bits(device
, DASD_STOPPED_SU
);
938 list_for_each_entry(device
, &lcu
->inactive_devices
, alias_list
)
939 dasd_device_set_stop_bits(device
, DASD_STOPPED_SU
);
940 list_for_each_entry(pavgroup
, &lcu
->grouplist
, group
) {
941 list_for_each_entry(device
, &pavgroup
->baselist
, alias_list
)
942 dasd_device_set_stop_bits(device
, DASD_STOPPED_SU
);
943 list_for_each_entry(device
, &pavgroup
->aliaslist
, alias_list
)
944 dasd_device_set_stop_bits(device
, DASD_STOPPED_SU
);
948 static void _unstop_all_devices_on_lcu(struct alias_lcu
*lcu
)
950 struct alias_pav_group
*pavgroup
;
951 struct dasd_device
*device
;
953 list_for_each_entry(device
, &lcu
->active_devices
, alias_list
)
954 dasd_device_remove_stop_bits(device
, DASD_STOPPED_SU
);
955 list_for_each_entry(device
, &lcu
->inactive_devices
, alias_list
)
956 dasd_device_remove_stop_bits(device
, DASD_STOPPED_SU
);
957 list_for_each_entry(pavgroup
, &lcu
->grouplist
, group
) {
958 list_for_each_entry(device
, &pavgroup
->baselist
, alias_list
)
959 dasd_device_remove_stop_bits(device
, DASD_STOPPED_SU
);
960 list_for_each_entry(device
, &pavgroup
->aliaslist
, alias_list
)
961 dasd_device_remove_stop_bits(device
, DASD_STOPPED_SU
);
965 static void summary_unit_check_handling_work(struct work_struct
*work
)
967 struct alias_lcu
*lcu
;
968 struct summary_unit_check_work_data
*suc_data
;
970 struct dasd_device
*device
;
972 suc_data
= container_of(work
, struct summary_unit_check_work_data
,
974 lcu
= container_of(suc_data
, struct alias_lcu
, suc_data
);
975 device
= suc_data
->device
;
977 /* 1. flush alias devices */
978 flush_all_alias_devices_on_lcu(lcu
);
980 /* 2. reset summary unit check */
981 spin_lock_irqsave(get_ccwdev_lock(device
->cdev
), flags
);
982 dasd_device_remove_stop_bits(device
,
983 (DASD_STOPPED_SU
| DASD_STOPPED_PENDING
));
984 spin_unlock_irqrestore(get_ccwdev_lock(device
->cdev
), flags
);
985 reset_summary_unit_check(lcu
, device
, suc_data
->reason
);
987 _trylock_and_lock_lcu_irqsave(lcu
, NULL
, &flags
);
988 _unstop_all_devices_on_lcu(lcu
);
989 _restart_all_base_devices_on_lcu(lcu
);
990 /* 3. read new alias configuration */
991 _schedule_lcu_update(lcu
, device
);
992 lcu
->suc_data
.device
= NULL
;
993 dasd_put_device(device
);
994 _unlock_all_devices_on_lcu(lcu
, NULL
, NULL
);
995 spin_unlock_irqrestore(&lcu
->lock
, flags
);
999 * note: this will be called from int handler context (cdev locked)
1001 void dasd_alias_handle_summary_unit_check(struct dasd_device
*device
,
1004 struct dasd_eckd_private
*private = device
->private;
1005 struct alias_lcu
*lcu
;
1009 sense
= dasd_get_sense(irb
);
1012 DBF_DEV_EVENT(DBF_NOTICE
, device
, "%s %x",
1013 "eckd handle summary unit check: reason", reason
);
1015 DBF_DEV_EVENT(DBF_WARNING
, device
, "%s",
1016 "eckd handle summary unit check:"
1017 " no reason code available");
1023 DBF_DEV_EVENT(DBF_WARNING
, device
, "%s",
1024 "device not ready to handle summary"
1025 " unit check (no lcu structure)");
1028 _trylock_and_lock_lcu(lcu
, device
);
1029 /* If this device is about to be removed just return and wait for
1030 * the next interrupt on a different device
1032 if (list_empty(&device
->alias_list
)) {
1033 DBF_DEV_EVENT(DBF_WARNING
, device
, "%s",
1034 "device is in offline processing,"
1035 " don't do summary unit check handling");
1036 _unlock_all_devices_on_lcu(lcu
, device
, NULL
);
1037 spin_unlock(&lcu
->lock
);
1040 if (lcu
->suc_data
.device
) {
1041 /* already scheduled or running */
1042 DBF_DEV_EVENT(DBF_WARNING
, device
, "%s",
1043 "previous instance of summary unit check worker"
1045 _unlock_all_devices_on_lcu(lcu
, device
, NULL
);
1046 spin_unlock(&lcu
->lock
);
1049 _stop_all_devices_on_lcu(lcu
);
1050 /* prepare for lcu_update */
1051 private->lcu
->flags
|= NEED_UAC_UPDATE
| UPDATE_PENDING
;
1052 lcu
->suc_data
.reason
= reason
;
1053 lcu
->suc_data
.device
= device
;
1054 dasd_get_device(device
);
1055 _unlock_all_devices_on_lcu(lcu
, device
, NULL
);
1056 spin_unlock(&lcu
->lock
);
1057 if (!schedule_work(&lcu
->suc_data
.worker
))
1058 dasd_put_device(device
);