Commit | Line | Data |
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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 | ||
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 | ||
40 | static void summary_unit_check_handling_work(struct work_struct *); | |
41 | static void lcu_update_work(struct work_struct *); | |
42 | static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *); | |
43 | ||
44 | static struct alias_root aliastree = { | |
45 | .serverlist = LIST_HEAD_INIT(aliastree.serverlist), | |
46 | .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock), | |
47 | }; | |
48 | ||
49 | static 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 | ||
62 | static 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 | ||
73 | static 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 | ||
100 | static 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 | ||
114 | static void _free_server(struct alias_server *server) | |
115 | { | |
116 | kfree(server); | |
117 | } | |
118 | ||
119 | static 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 | ||
154 | out_err4: | |
155 | kfree(lcu->rsu_cqr->cpaddr); | |
156 | out_err3: | |
157 | kfree(lcu->rsu_cqr); | |
158 | out_err2: | |
159 | kfree(lcu->uac); | |
160 | out_err1: | |
161 | kfree(lcu); | |
162 | return ERR_PTR(-ENOMEM); | |
163 | } | |
164 | ||
165 | static 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 | */ | |
181 | int 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 | */ | |
244 | void 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 | */ | |
303 | static 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 | ||
348 | static 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 | ||
369 | static 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 | ||
431 | static 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 | ||
485 | static 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 | ||
514 | static 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 | ||
555 | int 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 | ||
579 | int 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 | ||
593 | struct 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 | */ | |
641 | static 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 | ||
670 | static 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 | ||
699 | static 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 | ||
a806170e HC |
748 | static void __stop_device_on_lcu(struct dasd_device *device, |
749 | struct dasd_device *pos) | |
750 | { | |
751 | /* If pos == device then device is already locked! */ | |
752 | if (pos == device) { | |
753 | pos->stopped |= DASD_STOPPED_SU; | |
754 | return; | |
755 | } | |
756 | spin_lock(get_ccwdev_lock(pos->cdev)); | |
757 | pos->stopped |= DASD_STOPPED_SU; | |
758 | spin_unlock(get_ccwdev_lock(pos->cdev)); | |
759 | } | |
760 | ||
8e09f215 SW |
761 | /* |
762 | * This function is called in interrupt context, so the | |
763 | * cdev lock for device is already locked! | |
764 | */ | |
765 | static void _stop_all_devices_on_lcu(struct alias_lcu *lcu, | |
766 | struct dasd_device *device) | |
767 | { | |
768 | struct alias_pav_group *pavgroup; | |
769 | struct dasd_device *pos; | |
770 | ||
a806170e HC |
771 | list_for_each_entry(pos, &lcu->active_devices, alias_list) |
772 | __stop_device_on_lcu(device, pos); | |
773 | list_for_each_entry(pos, &lcu->inactive_devices, alias_list) | |
774 | __stop_device_on_lcu(device, pos); | |
8e09f215 | 775 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { |
a806170e HC |
776 | list_for_each_entry(pos, &pavgroup->baselist, alias_list) |
777 | __stop_device_on_lcu(device, pos); | |
778 | list_for_each_entry(pos, &pavgroup->aliaslist, alias_list) | |
779 | __stop_device_on_lcu(device, pos); | |
8e09f215 SW |
780 | } |
781 | } | |
782 | ||
783 | static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu) | |
784 | { | |
785 | struct alias_pav_group *pavgroup; | |
786 | struct dasd_device *device; | |
787 | unsigned long flags; | |
788 | ||
789 | list_for_each_entry(device, &lcu->active_devices, alias_list) { | |
790 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
791 | device->stopped &= ~DASD_STOPPED_SU; | |
792 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); | |
793 | } | |
794 | ||
795 | list_for_each_entry(device, &lcu->inactive_devices, alias_list) { | |
796 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
797 | device->stopped &= ~DASD_STOPPED_SU; | |
798 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); | |
799 | } | |
800 | ||
801 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { | |
802 | list_for_each_entry(device, &pavgroup->baselist, 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), | |
806 | flags); | |
807 | } | |
808 | list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { | |
809 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
810 | device->stopped &= ~DASD_STOPPED_SU; | |
811 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), | |
812 | flags); | |
813 | } | |
814 | } | |
815 | } | |
816 | ||
817 | static void summary_unit_check_handling_work(struct work_struct *work) | |
818 | { | |
819 | struct alias_lcu *lcu; | |
820 | struct summary_unit_check_work_data *suc_data; | |
821 | unsigned long flags; | |
822 | struct dasd_device *device; | |
823 | ||
824 | suc_data = container_of(work, struct summary_unit_check_work_data, | |
825 | worker); | |
826 | lcu = container_of(suc_data, struct alias_lcu, suc_data); | |
827 | device = suc_data->device; | |
828 | ||
829 | /* 1. flush alias devices */ | |
830 | flush_all_alias_devices_on_lcu(lcu); | |
831 | ||
832 | /* 2. reset summary unit check */ | |
833 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
834 | device->stopped &= ~(DASD_STOPPED_SU | DASD_STOPPED_PENDING); | |
835 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); | |
836 | reset_summary_unit_check(lcu, device, suc_data->reason); | |
837 | ||
838 | spin_lock_irqsave(&lcu->lock, flags); | |
839 | _unstop_all_devices_on_lcu(lcu); | |
840 | _restart_all_base_devices_on_lcu(lcu); | |
841 | /* 3. read new alias configuration */ | |
842 | _schedule_lcu_update(lcu, device); | |
843 | lcu->suc_data.device = NULL; | |
844 | spin_unlock_irqrestore(&lcu->lock, flags); | |
845 | } | |
846 | ||
847 | /* | |
848 | * note: this will be called from int handler context (cdev locked) | |
849 | */ | |
850 | void dasd_alias_handle_summary_unit_check(struct dasd_device *device, | |
851 | struct irb *irb) | |
852 | { | |
853 | struct alias_lcu *lcu; | |
854 | char reason; | |
855 | struct dasd_eckd_private *private; | |
856 | ||
857 | private = (struct dasd_eckd_private *) device->private; | |
858 | ||
859 | reason = irb->ecw[8]; | |
860 | DEV_MESSAGE(KERN_WARNING, device, "%s %x", | |
861 | "eckd handle summary unit check: reason", reason); | |
862 | ||
863 | lcu = private->lcu; | |
864 | if (!lcu) { | |
865 | DEV_MESSAGE(KERN_WARNING, device, "%s", | |
866 | "device not ready to handle summary" | |
867 | " unit check (no lcu structure)"); | |
868 | return; | |
869 | } | |
870 | spin_lock(&lcu->lock); | |
871 | _stop_all_devices_on_lcu(lcu, device); | |
872 | /* prepare for lcu_update */ | |
873 | private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING; | |
874 | /* If this device is about to be removed just return and wait for | |
875 | * the next interrupt on a different device | |
876 | */ | |
877 | if (list_empty(&device->alias_list)) { | |
878 | DEV_MESSAGE(KERN_WARNING, device, "%s", | |
879 | "device is in offline processing," | |
880 | " don't do summary unit check handling"); | |
881 | spin_unlock(&lcu->lock); | |
882 | return; | |
883 | } | |
884 | if (lcu->suc_data.device) { | |
885 | /* already scheduled or running */ | |
886 | DEV_MESSAGE(KERN_WARNING, device, "%s", | |
887 | "previous instance of summary unit check worker" | |
888 | " still pending"); | |
889 | spin_unlock(&lcu->lock); | |
890 | return ; | |
891 | } | |
892 | lcu->suc_data.reason = reason; | |
893 | lcu->suc_data.device = device; | |
894 | spin_unlock(&lcu->lock); | |
895 | schedule_work(&lcu->suc_data.worker); | |
896 | }; |