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8e09f215 SW |
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 | ||
ca99dab0 | 8 | #define KMSG_COMPONENT "dasd-eckd" |
fc19f381 | 9 | |
8e09f215 SW |
10 | #include <linux/list.h> |
11 | #include <asm/ebcdic.h> | |
12 | #include "dasd_int.h" | |
13 | #include "dasd_eckd.h" | |
14 | ||
15 | #ifdef PRINTK_HEADER | |
16 | #undef PRINTK_HEADER | |
17 | #endif /* PRINTK_HEADER */ | |
18 | #define PRINTK_HEADER "dasd(eckd):" | |
19 | ||
20 | ||
21 | /* | |
22 | * General concept of alias management: | |
23 | * - PAV and DASD alias management is specific to the eckd discipline. | |
24 | * - A device is connected to an lcu as long as the device exists. | |
25 | * dasd_alias_make_device_known_to_lcu will be called wenn the | |
26 | * device is checked by the eckd discipline and | |
27 | * dasd_alias_disconnect_device_from_lcu will be called | |
28 | * before the device is deleted. | |
29 | * - The dasd_alias_add_device / dasd_alias_remove_device | |
30 | * functions mark the point when a device is 'ready for service'. | |
31 | * - A summary unit check is a rare occasion, but it is mandatory to | |
32 | * support it. It requires some complex recovery actions before the | |
33 | * devices can be used again (see dasd_alias_handle_summary_unit_check). | |
34 | * - dasd_alias_get_start_dev will find an alias device that can be used | |
35 | * instead of the base device and does some (very simple) load balancing. | |
36 | * This is the function that gets called for each I/O, so when improving | |
37 | * something, this function should get faster or better, the rest has just | |
38 | * to be correct. | |
39 | */ | |
40 | ||
41 | ||
42 | static void summary_unit_check_handling_work(struct work_struct *); | |
43 | static void lcu_update_work(struct work_struct *); | |
44 | static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *); | |
45 | ||
46 | static struct alias_root aliastree = { | |
47 | .serverlist = LIST_HEAD_INIT(aliastree.serverlist), | |
48 | .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock), | |
49 | }; | |
50 | ||
51 | static struct alias_server *_find_server(struct dasd_uid *uid) | |
52 | { | |
53 | struct alias_server *pos; | |
54 | list_for_each_entry(pos, &aliastree.serverlist, server) { | |
55 | if (!strncmp(pos->uid.vendor, uid->vendor, | |
56 | sizeof(uid->vendor)) | |
57 | && !strncmp(pos->uid.serial, uid->serial, | |
58 | sizeof(uid->serial))) | |
59 | return pos; | |
60 | }; | |
61 | return NULL; | |
62 | } | |
63 | ||
64 | static struct alias_lcu *_find_lcu(struct alias_server *server, | |
65 | struct dasd_uid *uid) | |
66 | { | |
67 | struct alias_lcu *pos; | |
68 | list_for_each_entry(pos, &server->lculist, lcu) { | |
69 | if (pos->uid.ssid == uid->ssid) | |
70 | return pos; | |
71 | }; | |
72 | return NULL; | |
73 | } | |
74 | ||
75 | static struct alias_pav_group *_find_group(struct alias_lcu *lcu, | |
76 | struct dasd_uid *uid) | |
77 | { | |
78 | struct alias_pav_group *pos; | |
79 | __u8 search_unit_addr; | |
80 | ||
81 | /* for hyper pav there is only one group */ | |
82 | if (lcu->pav == HYPER_PAV) { | |
83 | if (list_empty(&lcu->grouplist)) | |
84 | return NULL; | |
85 | else | |
86 | return list_first_entry(&lcu->grouplist, | |
87 | struct alias_pav_group, group); | |
88 | } | |
89 | ||
90 | /* for base pav we have to find the group that matches the base */ | |
91 | if (uid->type == UA_BASE_DEVICE) | |
92 | search_unit_addr = uid->real_unit_addr; | |
93 | else | |
94 | search_unit_addr = uid->base_unit_addr; | |
95 | list_for_each_entry(pos, &lcu->grouplist, group) { | |
4abb08c2 SW |
96 | if (pos->uid.base_unit_addr == search_unit_addr && |
97 | !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit))) | |
8e09f215 SW |
98 | return pos; |
99 | }; | |
100 | return NULL; | |
101 | } | |
102 | ||
103 | static struct alias_server *_allocate_server(struct dasd_uid *uid) | |
104 | { | |
105 | struct alias_server *server; | |
106 | ||
107 | server = kzalloc(sizeof(*server), GFP_KERNEL); | |
108 | if (!server) | |
109 | return ERR_PTR(-ENOMEM); | |
110 | memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor)); | |
111 | memcpy(server->uid.serial, uid->serial, sizeof(uid->serial)); | |
112 | INIT_LIST_HEAD(&server->server); | |
113 | INIT_LIST_HEAD(&server->lculist); | |
114 | return server; | |
115 | } | |
116 | ||
117 | static void _free_server(struct alias_server *server) | |
118 | { | |
119 | kfree(server); | |
120 | } | |
121 | ||
122 | static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid) | |
123 | { | |
124 | struct alias_lcu *lcu; | |
125 | ||
126 | lcu = kzalloc(sizeof(*lcu), GFP_KERNEL); | |
127 | if (!lcu) | |
128 | return ERR_PTR(-ENOMEM); | |
129 | lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA); | |
130 | if (!lcu->uac) | |
131 | goto out_err1; | |
132 | lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA); | |
133 | if (!lcu->rsu_cqr) | |
134 | goto out_err2; | |
135 | lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1), | |
136 | GFP_KERNEL | GFP_DMA); | |
137 | if (!lcu->rsu_cqr->cpaddr) | |
138 | goto out_err3; | |
139 | lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA); | |
140 | if (!lcu->rsu_cqr->data) | |
141 | goto out_err4; | |
142 | ||
143 | memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor)); | |
144 | memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial)); | |
145 | lcu->uid.ssid = uid->ssid; | |
146 | lcu->pav = NO_PAV; | |
147 | lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING; | |
148 | INIT_LIST_HEAD(&lcu->lcu); | |
149 | INIT_LIST_HEAD(&lcu->inactive_devices); | |
150 | INIT_LIST_HEAD(&lcu->active_devices); | |
151 | INIT_LIST_HEAD(&lcu->grouplist); | |
152 | INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work); | |
153 | INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work); | |
154 | spin_lock_init(&lcu->lock); | |
155 | return lcu; | |
156 | ||
157 | out_err4: | |
158 | kfree(lcu->rsu_cqr->cpaddr); | |
159 | out_err3: | |
160 | kfree(lcu->rsu_cqr); | |
161 | out_err2: | |
162 | kfree(lcu->uac); | |
163 | out_err1: | |
164 | kfree(lcu); | |
165 | return ERR_PTR(-ENOMEM); | |
166 | } | |
167 | ||
168 | static void _free_lcu(struct alias_lcu *lcu) | |
169 | { | |
170 | kfree(lcu->rsu_cqr->data); | |
171 | kfree(lcu->rsu_cqr->cpaddr); | |
172 | kfree(lcu->rsu_cqr); | |
173 | kfree(lcu->uac); | |
174 | kfree(lcu); | |
175 | } | |
176 | ||
177 | /* | |
178 | * This is the function that will allocate all the server and lcu data, | |
179 | * so this function must be called first for a new device. | |
180 | * If the return value is 1, the lcu was already known before, if it | |
181 | * is 0, this is a new lcu. | |
182 | * Negative return code indicates that something went wrong (e.g. -ENOMEM) | |
183 | */ | |
184 | int dasd_alias_make_device_known_to_lcu(struct dasd_device *device) | |
185 | { | |
186 | struct dasd_eckd_private *private; | |
187 | unsigned long flags; | |
188 | struct alias_server *server, *newserver; | |
189 | struct alias_lcu *lcu, *newlcu; | |
190 | int is_lcu_known; | |
191 | struct dasd_uid *uid; | |
192 | ||
193 | private = (struct dasd_eckd_private *) device->private; | |
194 | uid = &private->uid; | |
195 | spin_lock_irqsave(&aliastree.lock, flags); | |
196 | is_lcu_known = 1; | |
197 | server = _find_server(uid); | |
198 | if (!server) { | |
199 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
200 | newserver = _allocate_server(uid); | |
201 | if (IS_ERR(newserver)) | |
202 | return PTR_ERR(newserver); | |
203 | spin_lock_irqsave(&aliastree.lock, flags); | |
204 | server = _find_server(uid); | |
205 | if (!server) { | |
206 | list_add(&newserver->server, &aliastree.serverlist); | |
207 | server = newserver; | |
208 | is_lcu_known = 0; | |
209 | } else { | |
210 | /* someone was faster */ | |
211 | _free_server(newserver); | |
212 | } | |
213 | } | |
214 | ||
215 | lcu = _find_lcu(server, uid); | |
216 | if (!lcu) { | |
217 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
218 | newlcu = _allocate_lcu(uid); | |
219 | if (IS_ERR(newlcu)) | |
220 | return PTR_ERR(lcu); | |
221 | spin_lock_irqsave(&aliastree.lock, flags); | |
222 | lcu = _find_lcu(server, uid); | |
223 | if (!lcu) { | |
224 | list_add(&newlcu->lcu, &server->lculist); | |
225 | lcu = newlcu; | |
226 | is_lcu_known = 0; | |
227 | } else { | |
228 | /* someone was faster */ | |
229 | _free_lcu(newlcu); | |
230 | } | |
231 | is_lcu_known = 0; | |
232 | } | |
233 | spin_lock(&lcu->lock); | |
234 | list_add(&device->alias_list, &lcu->inactive_devices); | |
235 | private->lcu = lcu; | |
236 | spin_unlock(&lcu->lock); | |
237 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
238 | ||
239 | return is_lcu_known; | |
240 | } | |
241 | ||
242 | /* | |
243 | * This function removes a device from the scope of alias management. | |
244 | * The complicated part is to make sure that it is not in use by | |
245 | * any of the workers. If necessary cancel the work. | |
246 | */ | |
247 | void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) | |
248 | { | |
249 | struct dasd_eckd_private *private; | |
250 | unsigned long flags; | |
251 | struct alias_lcu *lcu; | |
252 | struct alias_server *server; | |
253 | int was_pending; | |
254 | ||
255 | private = (struct dasd_eckd_private *) device->private; | |
256 | lcu = private->lcu; | |
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 | lcu->suc_data.device = NULL; | |
266 | } | |
267 | was_pending = 0; | |
268 | if (device == lcu->ruac_data.device) { | |
269 | spin_unlock_irqrestore(&lcu->lock, flags); | |
270 | was_pending = 1; | |
271 | cancel_delayed_work_sync(&lcu->ruac_data.dwork); | |
272 | spin_lock_irqsave(&lcu->lock, flags); | |
273 | if (device == lcu->ruac_data.device) | |
274 | lcu->ruac_data.device = NULL; | |
275 | } | |
276 | private->lcu = NULL; | |
277 | spin_unlock_irqrestore(&lcu->lock, flags); | |
278 | ||
279 | spin_lock_irqsave(&aliastree.lock, flags); | |
280 | spin_lock(&lcu->lock); | |
281 | if (list_empty(&lcu->grouplist) && | |
282 | list_empty(&lcu->active_devices) && | |
283 | list_empty(&lcu->inactive_devices)) { | |
284 | list_del(&lcu->lcu); | |
285 | spin_unlock(&lcu->lock); | |
286 | _free_lcu(lcu); | |
287 | lcu = NULL; | |
288 | } else { | |
289 | if (was_pending) | |
290 | _schedule_lcu_update(lcu, NULL); | |
291 | spin_unlock(&lcu->lock); | |
292 | } | |
293 | server = _find_server(&private->uid); | |
294 | if (server && list_empty(&server->lculist)) { | |
295 | list_del(&server->server); | |
296 | _free_server(server); | |
297 | } | |
298 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
299 | } | |
300 | ||
301 | /* | |
302 | * This function assumes that the unit address configuration stored | |
303 | * in the lcu is up to date and will update the device uid before | |
304 | * adding it to a pav group. | |
305 | */ | |
306 | static int _add_device_to_lcu(struct alias_lcu *lcu, | |
307 | struct dasd_device *device) | |
308 | { | |
309 | ||
310 | struct dasd_eckd_private *private; | |
311 | struct alias_pav_group *group; | |
312 | struct dasd_uid *uid; | |
313 | ||
314 | private = (struct dasd_eckd_private *) device->private; | |
315 | uid = &private->uid; | |
316 | uid->type = lcu->uac->unit[uid->real_unit_addr].ua_type; | |
317 | uid->base_unit_addr = lcu->uac->unit[uid->real_unit_addr].base_ua; | |
318 | dasd_set_uid(device->cdev, &private->uid); | |
319 | ||
320 | /* if we have no PAV anyway, we don't need to bother with PAV groups */ | |
321 | if (lcu->pav == NO_PAV) { | |
322 | list_move(&device->alias_list, &lcu->active_devices); | |
323 | return 0; | |
324 | } | |
325 | ||
326 | group = _find_group(lcu, uid); | |
327 | if (!group) { | |
328 | group = kzalloc(sizeof(*group), GFP_ATOMIC); | |
329 | if (!group) | |
330 | return -ENOMEM; | |
331 | memcpy(group->uid.vendor, uid->vendor, sizeof(uid->vendor)); | |
332 | memcpy(group->uid.serial, uid->serial, sizeof(uid->serial)); | |
333 | group->uid.ssid = uid->ssid; | |
334 | if (uid->type == UA_BASE_DEVICE) | |
335 | group->uid.base_unit_addr = uid->real_unit_addr; | |
336 | else | |
337 | group->uid.base_unit_addr = uid->base_unit_addr; | |
4abb08c2 | 338 | memcpy(group->uid.vduit, uid->vduit, sizeof(uid->vduit)); |
8e09f215 SW |
339 | INIT_LIST_HEAD(&group->group); |
340 | INIT_LIST_HEAD(&group->baselist); | |
341 | INIT_LIST_HEAD(&group->aliaslist); | |
342 | list_add(&group->group, &lcu->grouplist); | |
343 | } | |
344 | if (uid->type == UA_BASE_DEVICE) | |
345 | list_move(&device->alias_list, &group->baselist); | |
346 | else | |
347 | list_move(&device->alias_list, &group->aliaslist); | |
348 | private->pavgroup = group; | |
349 | return 0; | |
350 | }; | |
351 | ||
352 | static void _remove_device_from_lcu(struct alias_lcu *lcu, | |
353 | struct dasd_device *device) | |
354 | { | |
355 | struct dasd_eckd_private *private; | |
356 | struct alias_pav_group *group; | |
357 | ||
358 | private = (struct dasd_eckd_private *) device->private; | |
359 | list_move(&device->alias_list, &lcu->inactive_devices); | |
360 | group = private->pavgroup; | |
361 | if (!group) | |
362 | return; | |
363 | private->pavgroup = NULL; | |
364 | if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) { | |
365 | list_del(&group->group); | |
366 | kfree(group); | |
367 | return; | |
368 | } | |
369 | if (group->next == device) | |
370 | group->next = NULL; | |
371 | }; | |
372 | ||
373 | static int read_unit_address_configuration(struct dasd_device *device, | |
374 | struct alias_lcu *lcu) | |
375 | { | |
376 | struct dasd_psf_prssd_data *prssdp; | |
377 | struct dasd_ccw_req *cqr; | |
378 | struct ccw1 *ccw; | |
379 | int rc; | |
380 | unsigned long flags; | |
381 | ||
68b781fe | 382 | cqr = dasd_kmalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */, |
8e09f215 SW |
383 | (sizeof(struct dasd_psf_prssd_data)), |
384 | device); | |
385 | if (IS_ERR(cqr)) | |
386 | return PTR_ERR(cqr); | |
387 | cqr->startdev = device; | |
388 | cqr->memdev = device; | |
389 | clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); | |
390 | cqr->retries = 10; | |
391 | cqr->expires = 20 * HZ; | |
392 | ||
393 | /* Prepare for Read Subsystem Data */ | |
394 | prssdp = (struct dasd_psf_prssd_data *) cqr->data; | |
395 | memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data)); | |
396 | prssdp->order = PSF_ORDER_PRSSD; | |
397 | prssdp->suborder = 0x0e; /* Read unit address configuration */ | |
398 | /* all other bytes of prssdp must be zero */ | |
399 | ||
400 | ccw = cqr->cpaddr; | |
401 | ccw->cmd_code = DASD_ECKD_CCW_PSF; | |
402 | ccw->count = sizeof(struct dasd_psf_prssd_data); | |
403 | ccw->flags |= CCW_FLAG_CC; | |
404 | ccw->cda = (__u32)(addr_t) prssdp; | |
405 | ||
406 | /* Read Subsystem Data - feature codes */ | |
407 | memset(lcu->uac, 0, sizeof(*(lcu->uac))); | |
408 | ||
409 | ccw++; | |
410 | ccw->cmd_code = DASD_ECKD_CCW_RSSD; | |
411 | ccw->count = sizeof(*(lcu->uac)); | |
412 | ccw->cda = (__u32)(addr_t) lcu->uac; | |
413 | ||
414 | cqr->buildclk = get_clock(); | |
415 | cqr->status = DASD_CQR_FILLED; | |
416 | ||
417 | /* need to unset flag here to detect race with summary unit check */ | |
418 | spin_lock_irqsave(&lcu->lock, flags); | |
419 | lcu->flags &= ~NEED_UAC_UPDATE; | |
420 | spin_unlock_irqrestore(&lcu->lock, flags); | |
421 | ||
422 | do { | |
423 | rc = dasd_sleep_on(cqr); | |
424 | } while (rc && (cqr->retries > 0)); | |
425 | if (rc) { | |
426 | spin_lock_irqsave(&lcu->lock, flags); | |
427 | lcu->flags |= NEED_UAC_UPDATE; | |
428 | spin_unlock_irqrestore(&lcu->lock, flags); | |
429 | } | |
430 | dasd_kfree_request(cqr, cqr->memdev); | |
431 | return rc; | |
432 | } | |
433 | ||
434 | static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu) | |
435 | { | |
436 | unsigned long flags; | |
437 | struct alias_pav_group *pavgroup, *tempgroup; | |
438 | struct dasd_device *device, *tempdev; | |
439 | int i, rc; | |
440 | struct dasd_eckd_private *private; | |
441 | ||
442 | spin_lock_irqsave(&lcu->lock, flags); | |
443 | list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) { | |
444 | list_for_each_entry_safe(device, tempdev, &pavgroup->baselist, | |
445 | alias_list) { | |
446 | list_move(&device->alias_list, &lcu->active_devices); | |
447 | private = (struct dasd_eckd_private *) device->private; | |
448 | private->pavgroup = NULL; | |
449 | } | |
450 | list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist, | |
451 | alias_list) { | |
452 | list_move(&device->alias_list, &lcu->active_devices); | |
453 | private = (struct dasd_eckd_private *) device->private; | |
454 | private->pavgroup = NULL; | |
455 | } | |
456 | list_del(&pavgroup->group); | |
457 | kfree(pavgroup); | |
458 | } | |
459 | spin_unlock_irqrestore(&lcu->lock, flags); | |
460 | ||
461 | rc = read_unit_address_configuration(refdev, lcu); | |
462 | if (rc) | |
463 | return rc; | |
464 | ||
465 | spin_lock_irqsave(&lcu->lock, flags); | |
466 | lcu->pav = NO_PAV; | |
467 | for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) { | |
468 | switch (lcu->uac->unit[i].ua_type) { | |
469 | case UA_BASE_PAV_ALIAS: | |
470 | lcu->pav = BASE_PAV; | |
471 | break; | |
472 | case UA_HYPER_PAV_ALIAS: | |
473 | lcu->pav = HYPER_PAV; | |
474 | break; | |
475 | } | |
476 | if (lcu->pav != NO_PAV) | |
477 | break; | |
478 | } | |
479 | ||
480 | list_for_each_entry_safe(device, tempdev, &lcu->active_devices, | |
481 | alias_list) { | |
482 | _add_device_to_lcu(lcu, device); | |
483 | } | |
484 | spin_unlock_irqrestore(&lcu->lock, flags); | |
485 | return 0; | |
486 | } | |
487 | ||
488 | static void lcu_update_work(struct work_struct *work) | |
489 | { | |
490 | struct alias_lcu *lcu; | |
491 | struct read_uac_work_data *ruac_data; | |
492 | struct dasd_device *device; | |
493 | unsigned long flags; | |
494 | int rc; | |
495 | ||
496 | ruac_data = container_of(work, struct read_uac_work_data, dwork.work); | |
497 | lcu = container_of(ruac_data, struct alias_lcu, ruac_data); | |
498 | device = ruac_data->device; | |
499 | rc = _lcu_update(device, lcu); | |
500 | /* | |
501 | * Need to check flags again, as there could have been another | |
502 | * prepare_update or a new device a new device while we were still | |
503 | * processing the data | |
504 | */ | |
505 | spin_lock_irqsave(&lcu->lock, flags); | |
506 | if (rc || (lcu->flags & NEED_UAC_UPDATE)) { | |
fc19f381 | 507 | DBF_DEV_EVENT(DBF_WARNING, device, "could not update" |
8e09f215 SW |
508 | " alias data in lcu (rc = %d), retry later", rc); |
509 | schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ); | |
510 | } else { | |
511 | lcu->ruac_data.device = NULL; | |
512 | lcu->flags &= ~UPDATE_PENDING; | |
513 | } | |
514 | spin_unlock_irqrestore(&lcu->lock, flags); | |
515 | } | |
516 | ||
517 | static int _schedule_lcu_update(struct alias_lcu *lcu, | |
518 | struct dasd_device *device) | |
519 | { | |
520 | struct dasd_device *usedev = NULL; | |
521 | struct alias_pav_group *group; | |
522 | ||
523 | lcu->flags |= NEED_UAC_UPDATE; | |
524 | if (lcu->ruac_data.device) { | |
525 | /* already scheduled or running */ | |
526 | return 0; | |
527 | } | |
528 | if (device && !list_empty(&device->alias_list)) | |
529 | usedev = device; | |
530 | ||
531 | if (!usedev && !list_empty(&lcu->grouplist)) { | |
532 | group = list_first_entry(&lcu->grouplist, | |
533 | struct alias_pav_group, group); | |
534 | if (!list_empty(&group->baselist)) | |
535 | usedev = list_first_entry(&group->baselist, | |
536 | struct dasd_device, | |
537 | alias_list); | |
538 | else if (!list_empty(&group->aliaslist)) | |
539 | usedev = list_first_entry(&group->aliaslist, | |
540 | struct dasd_device, | |
541 | alias_list); | |
542 | } | |
543 | if (!usedev && !list_empty(&lcu->active_devices)) { | |
544 | usedev = list_first_entry(&lcu->active_devices, | |
545 | struct dasd_device, alias_list); | |
546 | } | |
547 | /* | |
548 | * if we haven't found a proper device yet, give up for now, the next | |
549 | * device that will be set active will trigger an lcu update | |
550 | */ | |
551 | if (!usedev) | |
552 | return -EINVAL; | |
553 | lcu->ruac_data.device = usedev; | |
554 | schedule_delayed_work(&lcu->ruac_data.dwork, 0); | |
555 | return 0; | |
556 | } | |
557 | ||
558 | int dasd_alias_add_device(struct dasd_device *device) | |
559 | { | |
560 | struct dasd_eckd_private *private; | |
561 | struct alias_lcu *lcu; | |
562 | unsigned long flags; | |
563 | int rc; | |
564 | ||
565 | private = (struct dasd_eckd_private *) device->private; | |
566 | lcu = private->lcu; | |
567 | rc = 0; | |
568 | spin_lock_irqsave(&lcu->lock, flags); | |
569 | if (!(lcu->flags & UPDATE_PENDING)) { | |
570 | rc = _add_device_to_lcu(lcu, device); | |
571 | if (rc) | |
572 | lcu->flags |= UPDATE_PENDING; | |
573 | } | |
574 | if (lcu->flags & UPDATE_PENDING) { | |
575 | list_move(&device->alias_list, &lcu->active_devices); | |
576 | _schedule_lcu_update(lcu, device); | |
577 | } | |
578 | spin_unlock_irqrestore(&lcu->lock, flags); | |
579 | return rc; | |
580 | } | |
581 | ||
582 | int dasd_alias_remove_device(struct dasd_device *device) | |
583 | { | |
584 | struct dasd_eckd_private *private; | |
585 | struct alias_lcu *lcu; | |
586 | unsigned long flags; | |
587 | ||
588 | private = (struct dasd_eckd_private *) device->private; | |
589 | lcu = private->lcu; | |
590 | spin_lock_irqsave(&lcu->lock, flags); | |
591 | _remove_device_from_lcu(lcu, device); | |
592 | spin_unlock_irqrestore(&lcu->lock, flags); | |
593 | return 0; | |
594 | } | |
595 | ||
596 | struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device) | |
597 | { | |
598 | ||
599 | struct dasd_device *alias_device; | |
600 | struct alias_pav_group *group; | |
601 | struct alias_lcu *lcu; | |
602 | struct dasd_eckd_private *private, *alias_priv; | |
603 | unsigned long flags; | |
604 | ||
605 | private = (struct dasd_eckd_private *) base_device->private; | |
606 | group = private->pavgroup; | |
607 | lcu = private->lcu; | |
608 | if (!group || !lcu) | |
609 | return NULL; | |
610 | if (lcu->pav == NO_PAV || | |
611 | lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING)) | |
612 | return NULL; | |
613 | ||
614 | spin_lock_irqsave(&lcu->lock, flags); | |
615 | alias_device = group->next; | |
616 | if (!alias_device) { | |
617 | if (list_empty(&group->aliaslist)) { | |
618 | spin_unlock_irqrestore(&lcu->lock, flags); | |
619 | return NULL; | |
620 | } else { | |
621 | alias_device = list_first_entry(&group->aliaslist, | |
622 | struct dasd_device, | |
623 | alias_list); | |
624 | } | |
625 | } | |
626 | if (list_is_last(&alias_device->alias_list, &group->aliaslist)) | |
627 | group->next = list_first_entry(&group->aliaslist, | |
628 | struct dasd_device, alias_list); | |
629 | else | |
630 | group->next = list_first_entry(&alias_device->alias_list, | |
631 | struct dasd_device, alias_list); | |
632 | spin_unlock_irqrestore(&lcu->lock, flags); | |
633 | alias_priv = (struct dasd_eckd_private *) alias_device->private; | |
634 | if ((alias_priv->count < private->count) && !alias_device->stopped) | |
635 | return alias_device; | |
636 | else | |
637 | return NULL; | |
638 | } | |
639 | ||
640 | /* | |
641 | * Summary unit check handling depends on the way alias devices | |
642 | * are handled so it is done here rather then in dasd_eckd.c | |
643 | */ | |
644 | static int reset_summary_unit_check(struct alias_lcu *lcu, | |
645 | struct dasd_device *device, | |
646 | char reason) | |
647 | { | |
648 | struct dasd_ccw_req *cqr; | |
649 | int rc = 0; | |
f3eb5384 | 650 | struct ccw1 *ccw; |
8e09f215 SW |
651 | |
652 | cqr = lcu->rsu_cqr; | |
653 | strncpy((char *) &cqr->magic, "ECKD", 4); | |
654 | ASCEBC((char *) &cqr->magic, 4); | |
f3eb5384 SW |
655 | ccw = cqr->cpaddr; |
656 | ccw->cmd_code = DASD_ECKD_CCW_RSCK; | |
657 | ccw->flags = 0 ; | |
658 | ccw->count = 16; | |
659 | ccw->cda = (__u32)(addr_t) cqr->data; | |
8e09f215 SW |
660 | ((char *)cqr->data)[0] = reason; |
661 | ||
662 | clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); | |
663 | cqr->retries = 255; /* set retry counter to enable basic ERP */ | |
664 | cqr->startdev = device; | |
665 | cqr->memdev = device; | |
666 | cqr->block = NULL; | |
667 | cqr->expires = 5 * HZ; | |
668 | cqr->buildclk = get_clock(); | |
669 | cqr->status = DASD_CQR_FILLED; | |
670 | ||
671 | rc = dasd_sleep_on_immediatly(cqr); | |
672 | return rc; | |
673 | } | |
674 | ||
675 | static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu) | |
676 | { | |
677 | struct alias_pav_group *pavgroup; | |
678 | struct dasd_device *device; | |
679 | struct dasd_eckd_private *private; | |
680 | ||
681 | /* active and inactive list can contain alias as well as base devices */ | |
682 | list_for_each_entry(device, &lcu->active_devices, alias_list) { | |
683 | private = (struct dasd_eckd_private *) device->private; | |
684 | if (private->uid.type != UA_BASE_DEVICE) | |
685 | continue; | |
686 | dasd_schedule_block_bh(device->block); | |
687 | dasd_schedule_device_bh(device); | |
688 | } | |
689 | list_for_each_entry(device, &lcu->inactive_devices, alias_list) { | |
690 | private = (struct dasd_eckd_private *) device->private; | |
691 | if (private->uid.type != UA_BASE_DEVICE) | |
692 | continue; | |
693 | dasd_schedule_block_bh(device->block); | |
694 | dasd_schedule_device_bh(device); | |
695 | } | |
696 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { | |
697 | list_for_each_entry(device, &pavgroup->baselist, alias_list) { | |
698 | dasd_schedule_block_bh(device->block); | |
699 | dasd_schedule_device_bh(device); | |
700 | } | |
701 | } | |
702 | } | |
703 | ||
704 | static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu) | |
705 | { | |
706 | struct alias_pav_group *pavgroup; | |
707 | struct dasd_device *device, *temp; | |
708 | struct dasd_eckd_private *private; | |
709 | int rc; | |
710 | unsigned long flags; | |
711 | LIST_HEAD(active); | |
712 | ||
713 | /* | |
714 | * Problem here ist that dasd_flush_device_queue may wait | |
715 | * for termination of a request to complete. We can't keep | |
716 | * the lcu lock during that time, so we must assume that | |
717 | * the lists may have changed. | |
718 | * Idea: first gather all active alias devices in a separate list, | |
719 | * then flush the first element of this list unlocked, and afterwards | |
720 | * check if it is still on the list before moving it to the | |
721 | * active_devices list. | |
722 | */ | |
723 | ||
724 | spin_lock_irqsave(&lcu->lock, flags); | |
725 | list_for_each_entry_safe(device, temp, &lcu->active_devices, | |
726 | alias_list) { | |
727 | private = (struct dasd_eckd_private *) device->private; | |
728 | if (private->uid.type == UA_BASE_DEVICE) | |
729 | continue; | |
730 | list_move(&device->alias_list, &active); | |
731 | } | |
732 | ||
733 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { | |
734 | list_splice_init(&pavgroup->aliaslist, &active); | |
735 | } | |
736 | while (!list_empty(&active)) { | |
737 | device = list_first_entry(&active, struct dasd_device, | |
738 | alias_list); | |
739 | spin_unlock_irqrestore(&lcu->lock, flags); | |
740 | rc = dasd_flush_device_queue(device); | |
741 | spin_lock_irqsave(&lcu->lock, flags); | |
742 | /* | |
743 | * only move device around if it wasn't moved away while we | |
744 | * were waiting for the flush | |
745 | */ | |
746 | if (device == list_first_entry(&active, | |
747 | struct dasd_device, alias_list)) | |
748 | list_move(&device->alias_list, &lcu->active_devices); | |
749 | } | |
750 | spin_unlock_irqrestore(&lcu->lock, flags); | |
751 | } | |
752 | ||
a806170e HC |
753 | static void __stop_device_on_lcu(struct dasd_device *device, |
754 | struct dasd_device *pos) | |
755 | { | |
756 | /* If pos == device then device is already locked! */ | |
757 | if (pos == device) { | |
eb6e199b | 758 | dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); |
a806170e HC |
759 | return; |
760 | } | |
761 | spin_lock(get_ccwdev_lock(pos->cdev)); | |
eb6e199b | 762 | dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); |
a806170e HC |
763 | spin_unlock(get_ccwdev_lock(pos->cdev)); |
764 | } | |
765 | ||
8e09f215 SW |
766 | /* |
767 | * This function is called in interrupt context, so the | |
768 | * cdev lock for device is already locked! | |
769 | */ | |
770 | static void _stop_all_devices_on_lcu(struct alias_lcu *lcu, | |
771 | struct dasd_device *device) | |
772 | { | |
773 | struct alias_pav_group *pavgroup; | |
774 | struct dasd_device *pos; | |
775 | ||
a806170e HC |
776 | list_for_each_entry(pos, &lcu->active_devices, alias_list) |
777 | __stop_device_on_lcu(device, pos); | |
778 | list_for_each_entry(pos, &lcu->inactive_devices, alias_list) | |
779 | __stop_device_on_lcu(device, pos); | |
8e09f215 | 780 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { |
a806170e HC |
781 | list_for_each_entry(pos, &pavgroup->baselist, alias_list) |
782 | __stop_device_on_lcu(device, pos); | |
783 | list_for_each_entry(pos, &pavgroup->aliaslist, alias_list) | |
784 | __stop_device_on_lcu(device, pos); | |
8e09f215 SW |
785 | } |
786 | } | |
787 | ||
788 | static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu) | |
789 | { | |
790 | struct alias_pav_group *pavgroup; | |
791 | struct dasd_device *device; | |
792 | unsigned long flags; | |
793 | ||
794 | list_for_each_entry(device, &lcu->active_devices, alias_list) { | |
795 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 796 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
797 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); |
798 | } | |
799 | ||
800 | list_for_each_entry(device, &lcu->inactive_devices, alias_list) { | |
801 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 802 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
803 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); |
804 | } | |
805 | ||
806 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { | |
807 | list_for_each_entry(device, &pavgroup->baselist, alias_list) { | |
808 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 809 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
810 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), |
811 | flags); | |
812 | } | |
813 | list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { | |
814 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 815 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
816 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), |
817 | flags); | |
818 | } | |
819 | } | |
820 | } | |
821 | ||
822 | static void summary_unit_check_handling_work(struct work_struct *work) | |
823 | { | |
824 | struct alias_lcu *lcu; | |
825 | struct summary_unit_check_work_data *suc_data; | |
826 | unsigned long flags; | |
827 | struct dasd_device *device; | |
828 | ||
829 | suc_data = container_of(work, struct summary_unit_check_work_data, | |
830 | worker); | |
831 | lcu = container_of(suc_data, struct alias_lcu, suc_data); | |
832 | device = suc_data->device; | |
833 | ||
834 | /* 1. flush alias devices */ | |
835 | flush_all_alias_devices_on_lcu(lcu); | |
836 | ||
837 | /* 2. reset summary unit check */ | |
838 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b SW |
839 | dasd_device_remove_stop_bits(device, |
840 | (DASD_STOPPED_SU | DASD_STOPPED_PENDING)); | |
8e09f215 SW |
841 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); |
842 | reset_summary_unit_check(lcu, device, suc_data->reason); | |
843 | ||
844 | spin_lock_irqsave(&lcu->lock, flags); | |
845 | _unstop_all_devices_on_lcu(lcu); | |
846 | _restart_all_base_devices_on_lcu(lcu); | |
847 | /* 3. read new alias configuration */ | |
848 | _schedule_lcu_update(lcu, device); | |
849 | lcu->suc_data.device = NULL; | |
850 | spin_unlock_irqrestore(&lcu->lock, flags); | |
851 | } | |
852 | ||
853 | /* | |
854 | * note: this will be called from int handler context (cdev locked) | |
855 | */ | |
856 | void dasd_alias_handle_summary_unit_check(struct dasd_device *device, | |
857 | struct irb *irb) | |
858 | { | |
859 | struct alias_lcu *lcu; | |
860 | char reason; | |
861 | struct dasd_eckd_private *private; | |
f3eb5384 | 862 | char *sense; |
8e09f215 SW |
863 | |
864 | private = (struct dasd_eckd_private *) device->private; | |
865 | ||
f3eb5384 SW |
866 | sense = dasd_get_sense(irb); |
867 | if (sense) { | |
868 | reason = sense[8]; | |
869 | DBF_DEV_EVENT(DBF_NOTICE, device, "%s %x", | |
870 | "eckd handle summary unit check: reason", reason); | |
871 | } else { | |
872 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", | |
873 | "eckd handle summary unit check:" | |
874 | " no reason code available"); | |
875 | return; | |
876 | } | |
8e09f215 SW |
877 | |
878 | lcu = private->lcu; | |
879 | if (!lcu) { | |
fc19f381 | 880 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", |
8e09f215 SW |
881 | "device not ready to handle summary" |
882 | " unit check (no lcu structure)"); | |
883 | return; | |
884 | } | |
885 | spin_lock(&lcu->lock); | |
886 | _stop_all_devices_on_lcu(lcu, device); | |
887 | /* prepare for lcu_update */ | |
888 | private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING; | |
889 | /* If this device is about to be removed just return and wait for | |
890 | * the next interrupt on a different device | |
891 | */ | |
892 | if (list_empty(&device->alias_list)) { | |
fc19f381 | 893 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", |
8e09f215 SW |
894 | "device is in offline processing," |
895 | " don't do summary unit check handling"); | |
896 | spin_unlock(&lcu->lock); | |
897 | return; | |
898 | } | |
899 | if (lcu->suc_data.device) { | |
900 | /* already scheduled or running */ | |
fc19f381 | 901 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", |
8e09f215 SW |
902 | "previous instance of summary unit check worker" |
903 | " still pending"); | |
904 | spin_unlock(&lcu->lock); | |
905 | return ; | |
906 | } | |
907 | lcu->suc_data.reason = reason; | |
908 | lcu->suc_data.device = device; | |
909 | spin_unlock(&lcu->lock); | |
910 | schedule_work(&lcu->suc_data.worker); | |
911 | }; |