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-rw-r--r--drivers/s390/block/dasd_alias.c903
1 files changed, 903 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
new file mode 100644
index 000000000000..3a40bee9d358
--- /dev/null
+++ b/drivers/s390/block/dasd_alias.c
@@ -0,0 +1,903 @@
1/*
2 * PAV alias management for the DASD ECKD discipline
3 *
4 * Copyright IBM Corporation, 2007
5 * Author(s): Stefan Weinhuber <wein@de.ibm.com>
6 */
7
8#include <linux/list.h>
9#include <asm/ebcdic.h>
10#include "dasd_int.h"
11#include "dasd_eckd.h"
12
13#ifdef PRINTK_HEADER
14#undef PRINTK_HEADER
15#endif /* PRINTK_HEADER */
16#define PRINTK_HEADER "dasd(eckd):"
17
18
19/*
20 * General concept of alias management:
21 * - PAV and DASD alias management is specific to the eckd discipline.
22 * - A device is connected to an lcu as long as the device exists.
23 * dasd_alias_make_device_known_to_lcu will be called wenn the
24 * device is checked by the eckd discipline and
25 * dasd_alias_disconnect_device_from_lcu will be called
26 * before the device is deleted.
27 * - The dasd_alias_add_device / dasd_alias_remove_device
28 * functions mark the point when a device is 'ready for service'.
29 * - A summary unit check is a rare occasion, but it is mandatory to
30 * support it. It requires some complex recovery actions before the
31 * devices can be used again (see dasd_alias_handle_summary_unit_check).
32 * - dasd_alias_get_start_dev will find an alias device that can be used
33 * instead of the base device and does some (very simple) load balancing.
34 * This is the function that gets called for each I/O, so when improving
35 * something, this function should get faster or better, the rest has just
36 * to be correct.
37 */
38
39
40static void summary_unit_check_handling_work(struct work_struct *);
41static void lcu_update_work(struct work_struct *);
42static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *);
43
44static struct alias_root aliastree = {
45 .serverlist = LIST_HEAD_INIT(aliastree.serverlist),
46 .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock),
47};
48
49static struct alias_server *_find_server(struct dasd_uid *uid)
50{
51 struct alias_server *pos;
52 list_for_each_entry(pos, &aliastree.serverlist, server) {
53 if (!strncmp(pos->uid.vendor, uid->vendor,
54 sizeof(uid->vendor))
55 && !strncmp(pos->uid.serial, uid->serial,
56 sizeof(uid->serial)))
57 return pos;
58 };
59 return NULL;
60}
61
62static struct alias_lcu *_find_lcu(struct alias_server *server,
63 struct dasd_uid *uid)
64{
65 struct alias_lcu *pos;
66 list_for_each_entry(pos, &server->lculist, lcu) {
67 if (pos->uid.ssid == uid->ssid)
68 return pos;
69 };
70 return NULL;
71}
72
73static struct alias_pav_group *_find_group(struct alias_lcu *lcu,
74 struct dasd_uid *uid)
75{
76 struct alias_pav_group *pos;
77 __u8 search_unit_addr;
78
79 /* for hyper pav there is only one group */
80 if (lcu->pav == HYPER_PAV) {
81 if (list_empty(&lcu->grouplist))
82 return NULL;
83 else
84 return list_first_entry(&lcu->grouplist,
85 struct alias_pav_group, group);
86 }
87
88 /* for base pav we have to find the group that matches the base */
89 if (uid->type == UA_BASE_DEVICE)
90 search_unit_addr = uid->real_unit_addr;
91 else
92 search_unit_addr = uid->base_unit_addr;
93 list_for_each_entry(pos, &lcu->grouplist, group) {
94 if (pos->uid.base_unit_addr == search_unit_addr)
95 return pos;
96 };
97 return NULL;
98}
99
100static struct alias_server *_allocate_server(struct dasd_uid *uid)
101{
102 struct alias_server *server;
103
104 server = kzalloc(sizeof(*server), GFP_KERNEL);
105 if (!server)
106 return ERR_PTR(-ENOMEM);
107 memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor));
108 memcpy(server->uid.serial, uid->serial, sizeof(uid->serial));
109 INIT_LIST_HEAD(&server->server);
110 INIT_LIST_HEAD(&server->lculist);
111 return server;
112}
113
114static void _free_server(struct alias_server *server)
115{
116 kfree(server);
117}
118
119static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid)
120{
121 struct alias_lcu *lcu;
122
123 lcu = kzalloc(sizeof(*lcu), GFP_KERNEL);
124 if (!lcu)
125 return ERR_PTR(-ENOMEM);
126 lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA);
127 if (!lcu->uac)
128 goto out_err1;
129 lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA);
130 if (!lcu->rsu_cqr)
131 goto out_err2;
132 lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1),
133 GFP_KERNEL | GFP_DMA);
134 if (!lcu->rsu_cqr->cpaddr)
135 goto out_err3;
136 lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA);
137 if (!lcu->rsu_cqr->data)
138 goto out_err4;
139
140 memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor));
141 memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial));
142 lcu->uid.ssid = uid->ssid;
143 lcu->pav = NO_PAV;
144 lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING;
145 INIT_LIST_HEAD(&lcu->lcu);
146 INIT_LIST_HEAD(&lcu->inactive_devices);
147 INIT_LIST_HEAD(&lcu->active_devices);
148 INIT_LIST_HEAD(&lcu->grouplist);
149 INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work);
150 INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work);
151 spin_lock_init(&lcu->lock);
152 return lcu;
153
154out_err4:
155 kfree(lcu->rsu_cqr->cpaddr);
156out_err3:
157 kfree(lcu->rsu_cqr);
158out_err2:
159 kfree(lcu->uac);
160out_err1:
161 kfree(lcu);
162 return ERR_PTR(-ENOMEM);
163}
164
165static void _free_lcu(struct alias_lcu *lcu)
166{
167 kfree(lcu->rsu_cqr->data);
168 kfree(lcu->rsu_cqr->cpaddr);
169 kfree(lcu->rsu_cqr);
170 kfree(lcu->uac);
171 kfree(lcu);
172}
173
174/*
175 * This is the function that will allocate all the server and lcu data,
176 * so this function must be called first for a new device.
177 * If the return value is 1, the lcu was already known before, if it
178 * is 0, this is a new lcu.
179 * Negative return code indicates that something went wrong (e.g. -ENOMEM)
180 */
181int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
182{
183 struct dasd_eckd_private *private;
184 unsigned long flags;
185 struct alias_server *server, *newserver;
186 struct alias_lcu *lcu, *newlcu;
187 int is_lcu_known;
188 struct dasd_uid *uid;
189
190 private = (struct dasd_eckd_private *) device->private;
191 uid = &private->uid;
192 spin_lock_irqsave(&aliastree.lock, flags);
193 is_lcu_known = 1;
194 server = _find_server(uid);
195 if (!server) {
196 spin_unlock_irqrestore(&aliastree.lock, flags);
197 newserver = _allocate_server(uid);
198 if (IS_ERR(newserver))
199 return PTR_ERR(newserver);
200 spin_lock_irqsave(&aliastree.lock, flags);
201 server = _find_server(uid);
202 if (!server) {
203 list_add(&newserver->server, &aliastree.serverlist);
204 server = newserver;
205 is_lcu_known = 0;
206 } else {
207 /* someone was faster */
208 _free_server(newserver);
209 }
210 }
211
212 lcu = _find_lcu(server, uid);
213 if (!lcu) {
214 spin_unlock_irqrestore(&aliastree.lock, flags);
215 newlcu = _allocate_lcu(uid);
216 if (IS_ERR(newlcu))
217 return PTR_ERR(lcu);
218 spin_lock_irqsave(&aliastree.lock, flags);
219 lcu = _find_lcu(server, uid);
220 if (!lcu) {
221 list_add(&newlcu->lcu, &server->lculist);
222 lcu = newlcu;
223 is_lcu_known = 0;
224 } else {
225 /* someone was faster */
226 _free_lcu(newlcu);
227 }
228 is_lcu_known = 0;
229 }
230 spin_lock(&lcu->lock);
231 list_add(&device->alias_list, &lcu->inactive_devices);
232 private->lcu = lcu;
233 spin_unlock(&lcu->lock);
234 spin_unlock_irqrestore(&aliastree.lock, flags);
235
236 return is_lcu_known;
237}
238
239/*
240 * This function removes a device from the scope of alias management.
241 * The complicated part is to make sure that it is not in use by
242 * any of the workers. If necessary cancel the work.
243 */
244void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
245{
246 struct dasd_eckd_private *private;
247 unsigned long flags;
248 struct alias_lcu *lcu;
249 struct alias_server *server;
250 int was_pending;
251
252 private = (struct dasd_eckd_private *) device->private;
253 lcu = private->lcu;
254 spin_lock_irqsave(&lcu->lock, flags);
255 list_del_init(&device->alias_list);
256 /* make sure that the workers don't use this device */
257 if (device == lcu->suc_data.device) {
258 spin_unlock_irqrestore(&lcu->lock, flags);
259 cancel_work_sync(&lcu->suc_data.worker);
260 spin_lock_irqsave(&lcu->lock, flags);
261 if (device == lcu->suc_data.device)
262 lcu->suc_data.device = NULL;
263 }
264 was_pending = 0;
265 if (device == lcu->ruac_data.device) {
266 spin_unlock_irqrestore(&lcu->lock, flags);
267 was_pending = 1;
268 cancel_delayed_work_sync(&lcu->ruac_data.dwork);
269 spin_lock_irqsave(&lcu->lock, flags);
270 if (device == lcu->ruac_data.device)
271 lcu->ruac_data.device = NULL;
272 }
273 private->lcu = NULL;
274 spin_unlock_irqrestore(&lcu->lock, flags);
275
276 spin_lock_irqsave(&aliastree.lock, flags);
277 spin_lock(&lcu->lock);
278 if (list_empty(&lcu->grouplist) &&
279 list_empty(&lcu->active_devices) &&
280 list_empty(&lcu->inactive_devices)) {
281 list_del(&lcu->lcu);
282 spin_unlock(&lcu->lock);
283 _free_lcu(lcu);
284 lcu = NULL;
285 } else {
286 if (was_pending)
287 _schedule_lcu_update(lcu, NULL);
288 spin_unlock(&lcu->lock);
289 }
290 server = _find_server(&private->uid);
291 if (server && list_empty(&server->lculist)) {
292 list_del(&server->server);
293 _free_server(server);
294 }
295 spin_unlock_irqrestore(&aliastree.lock, flags);
296}
297
298/*
299 * This function assumes that the unit address configuration stored
300 * in the lcu is up to date and will update the device uid before
301 * adding it to a pav group.
302 */
303static int _add_device_to_lcu(struct alias_lcu *lcu,
304 struct dasd_device *device)
305{
306
307 struct dasd_eckd_private *private;
308 struct alias_pav_group *group;
309 struct dasd_uid *uid;
310
311 private = (struct dasd_eckd_private *) device->private;
312 uid = &private->uid;
313 uid->type = lcu->uac->unit[uid->real_unit_addr].ua_type;
314 uid->base_unit_addr = lcu->uac->unit[uid->real_unit_addr].base_ua;
315 dasd_set_uid(device->cdev, &private->uid);
316
317 /* if we have no PAV anyway, we don't need to bother with PAV groups */
318 if (lcu->pav == NO_PAV) {
319 list_move(&device->alias_list, &lcu->active_devices);
320 return 0;
321 }
322
323 group = _find_group(lcu, uid);
324 if (!group) {
325 group = kzalloc(sizeof(*group), GFP_ATOMIC);
326 if (!group)
327 return -ENOMEM;
328 memcpy(group->uid.vendor, uid->vendor, sizeof(uid->vendor));
329 memcpy(group->uid.serial, uid->serial, sizeof(uid->serial));
330 group->uid.ssid = uid->ssid;
331 if (uid->type == UA_BASE_DEVICE)
332 group->uid.base_unit_addr = uid->real_unit_addr;
333 else
334 group->uid.base_unit_addr = uid->base_unit_addr;
335 INIT_LIST_HEAD(&group->group);
336 INIT_LIST_HEAD(&group->baselist);
337 INIT_LIST_HEAD(&group->aliaslist);
338 list_add(&group->group, &lcu->grouplist);
339 }
340 if (uid->type == UA_BASE_DEVICE)
341 list_move(&device->alias_list, &group->baselist);
342 else
343 list_move(&device->alias_list, &group->aliaslist);
344 private->pavgroup = group;
345 return 0;
346};
347
348static void _remove_device_from_lcu(struct alias_lcu *lcu,
349 struct dasd_device *device)
350{
351 struct dasd_eckd_private *private;
352 struct alias_pav_group *group;
353
354 private = (struct dasd_eckd_private *) device->private;
355 list_move(&device->alias_list, &lcu->inactive_devices);
356 group = private->pavgroup;
357 if (!group)
358 return;
359 private->pavgroup = NULL;
360 if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) {
361 list_del(&group->group);
362 kfree(group);
363 return;
364 }
365 if (group->next == device)
366 group->next = NULL;
367};
368
369static int read_unit_address_configuration(struct dasd_device *device,
370 struct alias_lcu *lcu)
371{
372 struct dasd_psf_prssd_data *prssdp;
373 struct dasd_ccw_req *cqr;
374 struct ccw1 *ccw;
375 int rc;
376 unsigned long flags;
377
378 cqr = dasd_kmalloc_request("ECKD",
379 1 /* PSF */ + 1 /* RSSD */ ,
380 (sizeof(struct dasd_psf_prssd_data)),
381 device);
382 if (IS_ERR(cqr))
383 return PTR_ERR(cqr);
384 cqr->startdev = device;
385 cqr->memdev = device;
386 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
387 cqr->retries = 10;
388 cqr->expires = 20 * HZ;
389
390 /* Prepare for Read Subsystem Data */
391 prssdp = (struct dasd_psf_prssd_data *) cqr->data;
392 memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
393 prssdp->order = PSF_ORDER_PRSSD;
394 prssdp->suborder = 0x0e; /* Read unit address configuration */
395 /* all other bytes of prssdp must be zero */
396
397 ccw = cqr->cpaddr;
398 ccw->cmd_code = DASD_ECKD_CCW_PSF;
399 ccw->count = sizeof(struct dasd_psf_prssd_data);
400 ccw->flags |= CCW_FLAG_CC;
401 ccw->cda = (__u32)(addr_t) prssdp;
402
403 /* Read Subsystem Data - feature codes */
404 memset(lcu->uac, 0, sizeof(*(lcu->uac)));
405
406 ccw++;
407 ccw->cmd_code = DASD_ECKD_CCW_RSSD;
408 ccw->count = sizeof(*(lcu->uac));
409 ccw->cda = (__u32)(addr_t) lcu->uac;
410
411 cqr->buildclk = get_clock();
412 cqr->status = DASD_CQR_FILLED;
413
414 /* need to unset flag here to detect race with summary unit check */
415 spin_lock_irqsave(&lcu->lock, flags);
416 lcu->flags &= ~NEED_UAC_UPDATE;
417 spin_unlock_irqrestore(&lcu->lock, flags);
418
419 do {
420 rc = dasd_sleep_on(cqr);
421 } while (rc && (cqr->retries > 0));
422 if (rc) {
423 spin_lock_irqsave(&lcu->lock, flags);
424 lcu->flags |= NEED_UAC_UPDATE;
425 spin_unlock_irqrestore(&lcu->lock, flags);
426 }
427 dasd_kfree_request(cqr, cqr->memdev);
428 return rc;
429}
430
431static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
432{
433 unsigned long flags;
434 struct alias_pav_group *pavgroup, *tempgroup;
435 struct dasd_device *device, *tempdev;
436 int i, rc;
437 struct dasd_eckd_private *private;
438
439 spin_lock_irqsave(&lcu->lock, flags);
440 list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) {
441 list_for_each_entry_safe(device, tempdev, &pavgroup->baselist,
442 alias_list) {
443 list_move(&device->alias_list, &lcu->active_devices);
444 private = (struct dasd_eckd_private *) device->private;
445 private->pavgroup = NULL;
446 }
447 list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist,
448 alias_list) {
449 list_move(&device->alias_list, &lcu->active_devices);
450 private = (struct dasd_eckd_private *) device->private;
451 private->pavgroup = NULL;
452 }
453 list_del(&pavgroup->group);
454 kfree(pavgroup);
455 }
456 spin_unlock_irqrestore(&lcu->lock, flags);
457
458 rc = read_unit_address_configuration(refdev, lcu);
459 if (rc)
460 return rc;
461
462 spin_lock_irqsave(&lcu->lock, flags);
463 lcu->pav = NO_PAV;
464 for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) {
465 switch (lcu->uac->unit[i].ua_type) {
466 case UA_BASE_PAV_ALIAS:
467 lcu->pav = BASE_PAV;
468 break;
469 case UA_HYPER_PAV_ALIAS:
470 lcu->pav = HYPER_PAV;
471 break;
472 }
473 if (lcu->pav != NO_PAV)
474 break;
475 }
476
477 list_for_each_entry_safe(device, tempdev, &lcu->active_devices,
478 alias_list) {
479 _add_device_to_lcu(lcu, device);
480 }
481 spin_unlock_irqrestore(&lcu->lock, flags);
482 return 0;
483}
484
485static void lcu_update_work(struct work_struct *work)
486{
487 struct alias_lcu *lcu;
488 struct read_uac_work_data *ruac_data;
489 struct dasd_device *device;
490 unsigned long flags;
491 int rc;
492
493 ruac_data = container_of(work, struct read_uac_work_data, dwork.work);
494 lcu = container_of(ruac_data, struct alias_lcu, ruac_data);
495 device = ruac_data->device;
496 rc = _lcu_update(device, lcu);
497 /*
498 * Need to check flags again, as there could have been another
499 * prepare_update or a new device a new device while we were still
500 * processing the data
501 */
502 spin_lock_irqsave(&lcu->lock, flags);
503 if (rc || (lcu->flags & NEED_UAC_UPDATE)) {
504 DEV_MESSAGE(KERN_WARNING, device, "could not update"
505 " alias data in lcu (rc = %d), retry later", rc);
506 schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ);
507 } else {
508 lcu->ruac_data.device = NULL;
509 lcu->flags &= ~UPDATE_PENDING;
510 }
511 spin_unlock_irqrestore(&lcu->lock, flags);
512}
513
514static int _schedule_lcu_update(struct alias_lcu *lcu,
515 struct dasd_device *device)
516{
517 struct dasd_device *usedev = NULL;
518 struct alias_pav_group *group;
519
520 lcu->flags |= NEED_UAC_UPDATE;
521 if (lcu->ruac_data.device) {
522 /* already scheduled or running */
523 return 0;
524 }
525 if (device && !list_empty(&device->alias_list))
526 usedev = device;
527
528 if (!usedev && !list_empty(&lcu->grouplist)) {
529 group = list_first_entry(&lcu->grouplist,
530 struct alias_pav_group, group);
531 if (!list_empty(&group->baselist))
532 usedev = list_first_entry(&group->baselist,
533 struct dasd_device,
534 alias_list);
535 else if (!list_empty(&group->aliaslist))
536 usedev = list_first_entry(&group->aliaslist,
537 struct dasd_device,
538 alias_list);
539 }
540 if (!usedev && !list_empty(&lcu->active_devices)) {
541 usedev = list_first_entry(&lcu->active_devices,
542 struct dasd_device, alias_list);
543 }
544 /*
545 * if we haven't found a proper device yet, give up for now, the next
546 * device that will be set active will trigger an lcu update
547 */
548 if (!usedev)
549 return -EINVAL;
550 lcu->ruac_data.device = usedev;
551 schedule_delayed_work(&lcu->ruac_data.dwork, 0);
552 return 0;
553}
554
555int dasd_alias_add_device(struct dasd_device *device)
556{
557 struct dasd_eckd_private *private;
558 struct alias_lcu *lcu;
559 unsigned long flags;
560 int rc;
561
562 private = (struct dasd_eckd_private *) device->private;
563 lcu = private->lcu;
564 rc = 0;
565 spin_lock_irqsave(&lcu->lock, flags);
566 if (!(lcu->flags & UPDATE_PENDING)) {
567 rc = _add_device_to_lcu(lcu, device);
568 if (rc)
569 lcu->flags |= UPDATE_PENDING;
570 }
571 if (lcu->flags & UPDATE_PENDING) {
572 list_move(&device->alias_list, &lcu->active_devices);
573 _schedule_lcu_update(lcu, device);
574 }
575 spin_unlock_irqrestore(&lcu->lock, flags);
576 return rc;
577}
578
579int dasd_alias_remove_device(struct dasd_device *device)
580{
581 struct dasd_eckd_private *private;
582 struct alias_lcu *lcu;
583 unsigned long flags;
584
585 private = (struct dasd_eckd_private *) device->private;
586 lcu = private->lcu;
587 spin_lock_irqsave(&lcu->lock, flags);
588 _remove_device_from_lcu(lcu, device);
589 spin_unlock_irqrestore(&lcu->lock, flags);
590 return 0;
591}
592
593struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device)
594{
595
596 struct dasd_device *alias_device;
597 struct alias_pav_group *group;
598 struct alias_lcu *lcu;
599 struct dasd_eckd_private *private, *alias_priv;
600 unsigned long flags;
601
602 private = (struct dasd_eckd_private *) base_device->private;
603 group = private->pavgroup;
604 lcu = private->lcu;
605 if (!group || !lcu)
606 return NULL;
607 if (lcu->pav == NO_PAV ||
608 lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING))
609 return NULL;
610
611 spin_lock_irqsave(&lcu->lock, flags);
612 alias_device = group->next;
613 if (!alias_device) {
614 if (list_empty(&group->aliaslist)) {
615 spin_unlock_irqrestore(&lcu->lock, flags);
616 return NULL;
617 } else {
618 alias_device = list_first_entry(&group->aliaslist,
619 struct dasd_device,
620 alias_list);
621 }
622 }
623 if (list_is_last(&alias_device->alias_list, &group->aliaslist))
624 group->next = list_first_entry(&group->aliaslist,
625 struct dasd_device, alias_list);
626 else
627 group->next = list_first_entry(&alias_device->alias_list,
628 struct dasd_device, alias_list);
629 spin_unlock_irqrestore(&lcu->lock, flags);
630 alias_priv = (struct dasd_eckd_private *) alias_device->private;
631 if ((alias_priv->count < private->count) && !alias_device->stopped)
632 return alias_device;
633 else
634 return NULL;
635}
636
637/*
638 * Summary unit check handling depends on the way alias devices
639 * are handled so it is done here rather then in dasd_eckd.c
640 */
641static int reset_summary_unit_check(struct alias_lcu *lcu,
642 struct dasd_device *device,
643 char reason)
644{
645 struct dasd_ccw_req *cqr;
646 int rc = 0;
647
648 cqr = lcu->rsu_cqr;
649 strncpy((char *) &cqr->magic, "ECKD", 4);
650 ASCEBC((char *) &cqr->magic, 4);
651 cqr->cpaddr->cmd_code = DASD_ECKD_CCW_RSCK;
652 cqr->cpaddr->flags = 0 ;
653 cqr->cpaddr->count = 16;
654 cqr->cpaddr->cda = (__u32)(addr_t) cqr->data;
655 ((char *)cqr->data)[0] = reason;
656
657 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
658 cqr->retries = 255; /* set retry counter to enable basic ERP */
659 cqr->startdev = device;
660 cqr->memdev = device;
661 cqr->block = NULL;
662 cqr->expires = 5 * HZ;
663 cqr->buildclk = get_clock();
664 cqr->status = DASD_CQR_FILLED;
665
666 rc = dasd_sleep_on_immediatly(cqr);
667 return rc;
668}
669
670static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu)
671{
672 struct alias_pav_group *pavgroup;
673 struct dasd_device *device;
674 struct dasd_eckd_private *private;
675
676 /* active and inactive list can contain alias as well as base devices */
677 list_for_each_entry(device, &lcu->active_devices, alias_list) {
678 private = (struct dasd_eckd_private *) device->private;
679 if (private->uid.type != UA_BASE_DEVICE)
680 continue;
681 dasd_schedule_block_bh(device->block);
682 dasd_schedule_device_bh(device);
683 }
684 list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
685 private = (struct dasd_eckd_private *) device->private;
686 if (private->uid.type != UA_BASE_DEVICE)
687 continue;
688 dasd_schedule_block_bh(device->block);
689 dasd_schedule_device_bh(device);
690 }
691 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
692 list_for_each_entry(device, &pavgroup->baselist, alias_list) {
693 dasd_schedule_block_bh(device->block);
694 dasd_schedule_device_bh(device);
695 }
696 }
697}
698
699static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu)
700{
701 struct alias_pav_group *pavgroup;
702 struct dasd_device *device, *temp;
703 struct dasd_eckd_private *private;
704 int rc;
705 unsigned long flags;
706 LIST_HEAD(active);
707
708 /*
709 * Problem here ist that dasd_flush_device_queue may wait
710 * for termination of a request to complete. We can't keep
711 * the lcu lock during that time, so we must assume that
712 * the lists may have changed.
713 * Idea: first gather all active alias devices in a separate list,
714 * then flush the first element of this list unlocked, and afterwards
715 * check if it is still on the list before moving it to the
716 * active_devices list.
717 */
718
719 spin_lock_irqsave(&lcu->lock, flags);
720 list_for_each_entry_safe(device, temp, &lcu->active_devices,
721 alias_list) {
722 private = (struct dasd_eckd_private *) device->private;
723 if (private->uid.type == UA_BASE_DEVICE)
724 continue;
725 list_move(&device->alias_list, &active);
726 }
727
728 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
729 list_splice_init(&pavgroup->aliaslist, &active);
730 }
731 while (!list_empty(&active)) {
732 device = list_first_entry(&active, struct dasd_device,
733 alias_list);
734 spin_unlock_irqrestore(&lcu->lock, flags);
735 rc = dasd_flush_device_queue(device);
736 spin_lock_irqsave(&lcu->lock, flags);
737 /*
738 * only move device around if it wasn't moved away while we
739 * were waiting for the flush
740 */
741 if (device == list_first_entry(&active,
742 struct dasd_device, alias_list))
743 list_move(&device->alias_list, &lcu->active_devices);
744 }
745 spin_unlock_irqrestore(&lcu->lock, flags);
746}
747
748/*
749 * This function is called in interrupt context, so the
750 * cdev lock for device is already locked!
751 */
752static void _stop_all_devices_on_lcu(struct alias_lcu *lcu,
753 struct dasd_device *device)
754{
755 struct alias_pav_group *pavgroup;
756 struct dasd_device *pos;
757
758 list_for_each_entry(pos, &lcu->active_devices, alias_list) {
759 if (pos != device)
760 spin_lock(get_ccwdev_lock(pos->cdev));
761 pos->stopped |= DASD_STOPPED_SU;
762 if (pos != device)
763 spin_unlock(get_ccwdev_lock(pos->cdev));
764 }
765 list_for_each_entry(pos, &lcu->inactive_devices, alias_list) {
766 if (pos != device)
767 spin_lock(get_ccwdev_lock(pos->cdev));
768 pos->stopped |= DASD_STOPPED_SU;
769 if (pos != device)
770 spin_unlock(get_ccwdev_lock(pos->cdev));
771 }
772 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
773 list_for_each_entry(pos, &pavgroup->baselist, alias_list) {
774 if (pos != device)
775 spin_lock(get_ccwdev_lock(pos->cdev));
776 pos->stopped |= DASD_STOPPED_SU;
777 if (pos != device)
778 spin_unlock(get_ccwdev_lock(pos->cdev));
779 }
780 list_for_each_entry(pos, &pavgroup->aliaslist, alias_list) {
781 if (pos != device)
782 spin_lock(get_ccwdev_lock(pos->cdev));
783 pos->stopped |= DASD_STOPPED_SU;
784 if (pos != device)
785 spin_unlock(get_ccwdev_lock(pos->cdev));
786 }
787 }
788}
789
790static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu)
791{
792 struct alias_pav_group *pavgroup;
793 struct dasd_device *device;
794 unsigned long flags;
795
796 list_for_each_entry(device, &lcu->active_devices, alias_list) {
797 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
798 device->stopped &= ~DASD_STOPPED_SU;
799 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
800 }
801
802 list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
803 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
804 device->stopped &= ~DASD_STOPPED_SU;
805 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
806 }
807
808 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
809 list_for_each_entry(device, &pavgroup->baselist, alias_list) {
810 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
811 device->stopped &= ~DASD_STOPPED_SU;
812 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
813 flags);
814 }
815 list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
816 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
817 device->stopped &= ~DASD_STOPPED_SU;
818 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
819 flags);
820 }
821 }
822}
823
824static void summary_unit_check_handling_work(struct work_struct *work)
825{
826 struct alias_lcu *lcu;
827 struct summary_unit_check_work_data *suc_data;
828 unsigned long flags;
829 struct dasd_device *device;
830
831 suc_data = container_of(work, struct summary_unit_check_work_data,
832 worker);
833 lcu = container_of(suc_data, struct alias_lcu, suc_data);
834 device = suc_data->device;
835
836 /* 1. flush alias devices */
837 flush_all_alias_devices_on_lcu(lcu);
838
839 /* 2. reset summary unit check */
840 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
841 device->stopped &= ~(DASD_STOPPED_SU | DASD_STOPPED_PENDING);
842 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
843 reset_summary_unit_check(lcu, device, suc_data->reason);
844
845 spin_lock_irqsave(&lcu->lock, flags);
846 _unstop_all_devices_on_lcu(lcu);
847 _restart_all_base_devices_on_lcu(lcu);
848 /* 3. read new alias configuration */
849 _schedule_lcu_update(lcu, device);
850 lcu->suc_data.device = NULL;
851 spin_unlock_irqrestore(&lcu->lock, flags);
852}
853
854/*
855 * note: this will be called from int handler context (cdev locked)
856 */
857void dasd_alias_handle_summary_unit_check(struct dasd_device *device,
858 struct irb *irb)
859{
860 struct alias_lcu *lcu;
861 char reason;
862 struct dasd_eckd_private *private;
863
864 private = (struct dasd_eckd_private *) device->private;
865
866 reason = irb->ecw[8];
867 DEV_MESSAGE(KERN_WARNING, device, "%s %x",
868 "eckd handle summary unit check: reason", reason);
869
870 lcu = private->lcu;
871 if (!lcu) {
872 DEV_MESSAGE(KERN_WARNING, device, "%s",
873 "device not ready to handle summary"
874 " unit check (no lcu structure)");
875 return;
876 }
877 spin_lock(&lcu->lock);
878 _stop_all_devices_on_lcu(lcu, device);
879 /* prepare for lcu_update */
880 private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING;
881 /* If this device is about to be removed just return and wait for
882 * the next interrupt on a different device
883 */
884 if (list_empty(&device->alias_list)) {
885 DEV_MESSAGE(KERN_WARNING, device, "%s",
886 "device is in offline processing,"
887 " don't do summary unit check handling");
888 spin_unlock(&lcu->lock);
889 return;
890 }
891 if (lcu->suc_data.device) {
892 /* already scheduled or running */
893 DEV_MESSAGE(KERN_WARNING, device, "%s",
894 "previous instance of summary unit check worker"
895 " still pending");
896 spin_unlock(&lcu->lock);
897 return ;
898 }
899 lcu->suc_data.reason = reason;
900 lcu->suc_data.device = device;
901 spin_unlock(&lcu->lock);
902 schedule_work(&lcu->suc_data.worker);
903};
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-31 19:22:32 -0500