Commit | Line | Data |
---|---|---|
8e09f215 SW |
1 | /* |
2 | * PAV alias management for the DASD ECKD discipline | |
3 | * | |
a53c8fab | 4 | * Copyright IBM Corp. 2007 |
8e09f215 SW |
5 | * Author(s): Stefan Weinhuber <wein@de.ibm.com> |
6 | */ | |
7 | ||
ca99dab0 | 8 | #define KMSG_COMPONENT "dasd-eckd" |
fc19f381 | 9 | |
8e09f215 | 10 | #include <linux/list.h> |
5a0e3ad6 | 11 | #include <linux/slab.h> |
8e09f215 SW |
12 | #include <asm/ebcdic.h> |
13 | #include "dasd_int.h" | |
14 | #include "dasd_eckd.h" | |
15 | ||
16 | #ifdef PRINTK_HEADER | |
17 | #undef PRINTK_HEADER | |
18 | #endif /* PRINTK_HEADER */ | |
19 | #define PRINTK_HEADER "dasd(eckd):" | |
20 | ||
21 | ||
22 | /* | |
23 | * General concept of alias management: | |
24 | * - PAV and DASD alias management is specific to the eckd discipline. | |
25 | * - A device is connected to an lcu as long as the device exists. | |
26 | * dasd_alias_make_device_known_to_lcu will be called wenn the | |
27 | * device is checked by the eckd discipline and | |
28 | * dasd_alias_disconnect_device_from_lcu will be called | |
29 | * before the device is deleted. | |
30 | * - The dasd_alias_add_device / dasd_alias_remove_device | |
31 | * functions mark the point when a device is 'ready for service'. | |
32 | * - A summary unit check is a rare occasion, but it is mandatory to | |
33 | * support it. It requires some complex recovery actions before the | |
34 | * devices can be used again (see dasd_alias_handle_summary_unit_check). | |
35 | * - dasd_alias_get_start_dev will find an alias device that can be used | |
36 | * instead of the base device and does some (very simple) load balancing. | |
37 | * This is the function that gets called for each I/O, so when improving | |
38 | * something, this function should get faster or better, the rest has just | |
39 | * to be correct. | |
40 | */ | |
41 | ||
42 | ||
43 | static void summary_unit_check_handling_work(struct work_struct *); | |
44 | static void lcu_update_work(struct work_struct *); | |
45 | static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *); | |
46 | ||
47 | static struct alias_root aliastree = { | |
48 | .serverlist = LIST_HEAD_INIT(aliastree.serverlist), | |
49 | .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock), | |
50 | }; | |
51 | ||
52 | static struct alias_server *_find_server(struct dasd_uid *uid) | |
53 | { | |
54 | struct alias_server *pos; | |
55 | list_for_each_entry(pos, &aliastree.serverlist, server) { | |
56 | if (!strncmp(pos->uid.vendor, uid->vendor, | |
57 | sizeof(uid->vendor)) | |
58 | && !strncmp(pos->uid.serial, uid->serial, | |
59 | sizeof(uid->serial))) | |
60 | return pos; | |
61 | }; | |
62 | return NULL; | |
63 | } | |
64 | ||
65 | static struct alias_lcu *_find_lcu(struct alias_server *server, | |
66 | struct dasd_uid *uid) | |
67 | { | |
68 | struct alias_lcu *pos; | |
69 | list_for_each_entry(pos, &server->lculist, lcu) { | |
70 | if (pos->uid.ssid == uid->ssid) | |
71 | return pos; | |
72 | }; | |
73 | return NULL; | |
74 | } | |
75 | ||
76 | static struct alias_pav_group *_find_group(struct alias_lcu *lcu, | |
77 | struct dasd_uid *uid) | |
78 | { | |
79 | struct alias_pav_group *pos; | |
80 | __u8 search_unit_addr; | |
81 | ||
82 | /* for hyper pav there is only one group */ | |
83 | if (lcu->pav == HYPER_PAV) { | |
84 | if (list_empty(&lcu->grouplist)) | |
85 | return NULL; | |
86 | else | |
87 | return list_first_entry(&lcu->grouplist, | |
88 | struct alias_pav_group, group); | |
89 | } | |
90 | ||
91 | /* for base pav we have to find the group that matches the base */ | |
92 | if (uid->type == UA_BASE_DEVICE) | |
93 | search_unit_addr = uid->real_unit_addr; | |
94 | else | |
95 | search_unit_addr = uid->base_unit_addr; | |
96 | list_for_each_entry(pos, &lcu->grouplist, group) { | |
4abb08c2 SW |
97 | if (pos->uid.base_unit_addr == search_unit_addr && |
98 | !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit))) | |
8e09f215 SW |
99 | return pos; |
100 | }; | |
101 | return NULL; | |
102 | } | |
103 | ||
104 | static struct alias_server *_allocate_server(struct dasd_uid *uid) | |
105 | { | |
106 | struct alias_server *server; | |
107 | ||
108 | server = kzalloc(sizeof(*server), GFP_KERNEL); | |
109 | if (!server) | |
110 | return ERR_PTR(-ENOMEM); | |
111 | memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor)); | |
112 | memcpy(server->uid.serial, uid->serial, sizeof(uid->serial)); | |
113 | INIT_LIST_HEAD(&server->server); | |
114 | INIT_LIST_HEAD(&server->lculist); | |
115 | return server; | |
116 | } | |
117 | ||
118 | static void _free_server(struct alias_server *server) | |
119 | { | |
120 | kfree(server); | |
121 | } | |
122 | ||
123 | static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid) | |
124 | { | |
125 | struct alias_lcu *lcu; | |
126 | ||
127 | lcu = kzalloc(sizeof(*lcu), GFP_KERNEL); | |
128 | if (!lcu) | |
129 | return ERR_PTR(-ENOMEM); | |
130 | lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA); | |
131 | if (!lcu->uac) | |
132 | goto out_err1; | |
133 | lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA); | |
134 | if (!lcu->rsu_cqr) | |
135 | goto out_err2; | |
136 | lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1), | |
137 | GFP_KERNEL | GFP_DMA); | |
138 | if (!lcu->rsu_cqr->cpaddr) | |
139 | goto out_err3; | |
140 | lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA); | |
141 | if (!lcu->rsu_cqr->data) | |
142 | goto out_err4; | |
143 | ||
144 | memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor)); | |
145 | memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial)); | |
146 | lcu->uid.ssid = uid->ssid; | |
147 | lcu->pav = NO_PAV; | |
148 | lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING; | |
149 | INIT_LIST_HEAD(&lcu->lcu); | |
150 | INIT_LIST_HEAD(&lcu->inactive_devices); | |
151 | INIT_LIST_HEAD(&lcu->active_devices); | |
152 | INIT_LIST_HEAD(&lcu->grouplist); | |
153 | INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work); | |
154 | INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work); | |
155 | spin_lock_init(&lcu->lock); | |
f4ac1d02 | 156 | init_completion(&lcu->lcu_setup); |
8e09f215 SW |
157 | return lcu; |
158 | ||
159 | out_err4: | |
160 | kfree(lcu->rsu_cqr->cpaddr); | |
161 | out_err3: | |
162 | kfree(lcu->rsu_cqr); | |
163 | out_err2: | |
164 | kfree(lcu->uac); | |
165 | out_err1: | |
166 | kfree(lcu); | |
167 | return ERR_PTR(-ENOMEM); | |
168 | } | |
169 | ||
170 | static void _free_lcu(struct alias_lcu *lcu) | |
171 | { | |
172 | kfree(lcu->rsu_cqr->data); | |
173 | kfree(lcu->rsu_cqr->cpaddr); | |
174 | kfree(lcu->rsu_cqr); | |
175 | kfree(lcu->uac); | |
176 | kfree(lcu); | |
177 | } | |
178 | ||
179 | /* | |
180 | * This is the function that will allocate all the server and lcu data, | |
181 | * so this function must be called first for a new device. | |
182 | * If the return value is 1, the lcu was already known before, if it | |
183 | * is 0, this is a new lcu. | |
184 | * Negative return code indicates that something went wrong (e.g. -ENOMEM) | |
185 | */ | |
186 | int dasd_alias_make_device_known_to_lcu(struct dasd_device *device) | |
187 | { | |
188 | struct dasd_eckd_private *private; | |
189 | unsigned long flags; | |
190 | struct alias_server *server, *newserver; | |
191 | struct alias_lcu *lcu, *newlcu; | |
2dedf0d9 | 192 | struct dasd_uid uid; |
8e09f215 SW |
193 | |
194 | private = (struct dasd_eckd_private *) device->private; | |
2dedf0d9 SH |
195 | |
196 | device->discipline->get_uid(device, &uid); | |
8e09f215 | 197 | spin_lock_irqsave(&aliastree.lock, flags); |
2dedf0d9 | 198 | server = _find_server(&uid); |
8e09f215 SW |
199 | if (!server) { |
200 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
2dedf0d9 | 201 | newserver = _allocate_server(&uid); |
8e09f215 SW |
202 | if (IS_ERR(newserver)) |
203 | return PTR_ERR(newserver); | |
204 | spin_lock_irqsave(&aliastree.lock, flags); | |
2dedf0d9 | 205 | server = _find_server(&uid); |
8e09f215 SW |
206 | if (!server) { |
207 | list_add(&newserver->server, &aliastree.serverlist); | |
208 | server = newserver; | |
8e09f215 SW |
209 | } else { |
210 | /* someone was faster */ | |
211 | _free_server(newserver); | |
212 | } | |
213 | } | |
214 | ||
2dedf0d9 | 215 | lcu = _find_lcu(server, &uid); |
8e09f215 SW |
216 | if (!lcu) { |
217 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
2dedf0d9 | 218 | newlcu = _allocate_lcu(&uid); |
8e09f215 | 219 | if (IS_ERR(newlcu)) |
6d53cfe5 | 220 | return PTR_ERR(newlcu); |
8e09f215 | 221 | spin_lock_irqsave(&aliastree.lock, flags); |
2dedf0d9 | 222 | lcu = _find_lcu(server, &uid); |
8e09f215 SW |
223 | if (!lcu) { |
224 | list_add(&newlcu->lcu, &server->lculist); | |
225 | lcu = newlcu; | |
8e09f215 SW |
226 | } else { |
227 | /* someone was faster */ | |
228 | _free_lcu(newlcu); | |
229 | } | |
8e09f215 SW |
230 | } |
231 | spin_lock(&lcu->lock); | |
232 | list_add(&device->alias_list, &lcu->inactive_devices); | |
233 | private->lcu = lcu; | |
234 | spin_unlock(&lcu->lock); | |
235 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
236 | ||
f9f8d02f | 237 | return 0; |
f4ac1d02 SW |
238 | } |
239 | ||
8e09f215 SW |
240 | /* |
241 | * This function removes a device from the scope of alias management. | |
242 | * The complicated part is to make sure that it is not in use by | |
243 | * any of the workers. If necessary cancel the work. | |
244 | */ | |
245 | void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) | |
246 | { | |
247 | struct dasd_eckd_private *private; | |
248 | unsigned long flags; | |
249 | struct alias_lcu *lcu; | |
250 | struct alias_server *server; | |
251 | int was_pending; | |
2dedf0d9 | 252 | struct dasd_uid uid; |
8e09f215 SW |
253 | |
254 | private = (struct dasd_eckd_private *) device->private; | |
255 | lcu = private->lcu; | |
f602f6d6 SH |
256 | /* nothing to do if already disconnected */ |
257 | if (!lcu) | |
258 | return; | |
2dedf0d9 | 259 | device->discipline->get_uid(device, &uid); |
8e09f215 SW |
260 | spin_lock_irqsave(&lcu->lock, flags); |
261 | list_del_init(&device->alias_list); | |
262 | /* make sure that the workers don't use this device */ | |
263 | if (device == lcu->suc_data.device) { | |
264 | spin_unlock_irqrestore(&lcu->lock, flags); | |
265 | cancel_work_sync(&lcu->suc_data.worker); | |
266 | spin_lock_irqsave(&lcu->lock, flags); | |
267 | if (device == lcu->suc_data.device) | |
268 | lcu->suc_data.device = NULL; | |
269 | } | |
270 | was_pending = 0; | |
271 | if (device == lcu->ruac_data.device) { | |
272 | spin_unlock_irqrestore(&lcu->lock, flags); | |
273 | was_pending = 1; | |
274 | cancel_delayed_work_sync(&lcu->ruac_data.dwork); | |
275 | spin_lock_irqsave(&lcu->lock, flags); | |
276 | if (device == lcu->ruac_data.device) | |
277 | lcu->ruac_data.device = NULL; | |
278 | } | |
279 | private->lcu = NULL; | |
280 | spin_unlock_irqrestore(&lcu->lock, flags); | |
281 | ||
282 | spin_lock_irqsave(&aliastree.lock, flags); | |
283 | spin_lock(&lcu->lock); | |
284 | if (list_empty(&lcu->grouplist) && | |
285 | list_empty(&lcu->active_devices) && | |
286 | list_empty(&lcu->inactive_devices)) { | |
287 | list_del(&lcu->lcu); | |
288 | spin_unlock(&lcu->lock); | |
289 | _free_lcu(lcu); | |
290 | lcu = NULL; | |
291 | } else { | |
292 | if (was_pending) | |
293 | _schedule_lcu_update(lcu, NULL); | |
294 | spin_unlock(&lcu->lock); | |
295 | } | |
2dedf0d9 | 296 | server = _find_server(&uid); |
8e09f215 SW |
297 | if (server && list_empty(&server->lculist)) { |
298 | list_del(&server->server); | |
299 | _free_server(server); | |
300 | } | |
301 | spin_unlock_irqrestore(&aliastree.lock, flags); | |
302 | } | |
303 | ||
304 | /* | |
305 | * This function assumes that the unit address configuration stored | |
306 | * in the lcu is up to date and will update the device uid before | |
307 | * adding it to a pav group. | |
308 | */ | |
2dedf0d9 | 309 | |
8e09f215 | 310 | static int _add_device_to_lcu(struct alias_lcu *lcu, |
2dedf0d9 SH |
311 | struct dasd_device *device, |
312 | struct dasd_device *pos) | |
8e09f215 SW |
313 | { |
314 | ||
315 | struct dasd_eckd_private *private; | |
316 | struct alias_pav_group *group; | |
2dedf0d9 SH |
317 | struct dasd_uid uid; |
318 | unsigned long flags; | |
8e09f215 SW |
319 | |
320 | private = (struct dasd_eckd_private *) device->private; | |
2dedf0d9 SH |
321 | |
322 | /* only lock if not already locked */ | |
323 | if (device != pos) | |
324 | spin_lock_irqsave_nested(get_ccwdev_lock(device->cdev), flags, | |
325 | CDEV_NESTED_SECOND); | |
326 | private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type; | |
327 | private->uid.base_unit_addr = | |
328 | lcu->uac->unit[private->uid.real_unit_addr].base_ua; | |
329 | uid = private->uid; | |
330 | ||
331 | if (device != pos) | |
332 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); | |
8e09f215 SW |
333 | |
334 | /* if we have no PAV anyway, we don't need to bother with PAV groups */ | |
335 | if (lcu->pav == NO_PAV) { | |
336 | list_move(&device->alias_list, &lcu->active_devices); | |
337 | return 0; | |
338 | } | |
339 | ||
2dedf0d9 | 340 | group = _find_group(lcu, &uid); |
8e09f215 SW |
341 | if (!group) { |
342 | group = kzalloc(sizeof(*group), GFP_ATOMIC); | |
343 | if (!group) | |
344 | return -ENOMEM; | |
2dedf0d9 SH |
345 | memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor)); |
346 | memcpy(group->uid.serial, uid.serial, sizeof(uid.serial)); | |
347 | group->uid.ssid = uid.ssid; | |
348 | if (uid.type == UA_BASE_DEVICE) | |
349 | group->uid.base_unit_addr = uid.real_unit_addr; | |
8e09f215 | 350 | else |
2dedf0d9 SH |
351 | group->uid.base_unit_addr = uid.base_unit_addr; |
352 | memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit)); | |
8e09f215 SW |
353 | INIT_LIST_HEAD(&group->group); |
354 | INIT_LIST_HEAD(&group->baselist); | |
355 | INIT_LIST_HEAD(&group->aliaslist); | |
356 | list_add(&group->group, &lcu->grouplist); | |
357 | } | |
2dedf0d9 | 358 | if (uid.type == UA_BASE_DEVICE) |
8e09f215 SW |
359 | list_move(&device->alias_list, &group->baselist); |
360 | else | |
361 | list_move(&device->alias_list, &group->aliaslist); | |
362 | private->pavgroup = group; | |
363 | return 0; | |
364 | }; | |
365 | ||
366 | static void _remove_device_from_lcu(struct alias_lcu *lcu, | |
367 | struct dasd_device *device) | |
368 | { | |
369 | struct dasd_eckd_private *private; | |
370 | struct alias_pav_group *group; | |
371 | ||
372 | private = (struct dasd_eckd_private *) device->private; | |
373 | list_move(&device->alias_list, &lcu->inactive_devices); | |
374 | group = private->pavgroup; | |
375 | if (!group) | |
376 | return; | |
377 | private->pavgroup = NULL; | |
378 | if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) { | |
379 | list_del(&group->group); | |
380 | kfree(group); | |
381 | return; | |
382 | } | |
383 | if (group->next == device) | |
384 | group->next = NULL; | |
385 | }; | |
386 | ||
387 | static int read_unit_address_configuration(struct dasd_device *device, | |
388 | struct alias_lcu *lcu) | |
389 | { | |
390 | struct dasd_psf_prssd_data *prssdp; | |
391 | struct dasd_ccw_req *cqr; | |
392 | struct ccw1 *ccw; | |
393 | int rc; | |
394 | unsigned long flags; | |
395 | ||
68b781fe | 396 | cqr = dasd_kmalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */, |
8e09f215 SW |
397 | (sizeof(struct dasd_psf_prssd_data)), |
398 | device); | |
399 | if (IS_ERR(cqr)) | |
400 | return PTR_ERR(cqr); | |
401 | cqr->startdev = device; | |
402 | cqr->memdev = device; | |
403 | clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); | |
404 | cqr->retries = 10; | |
405 | cqr->expires = 20 * HZ; | |
406 | ||
407 | /* Prepare for Read Subsystem Data */ | |
408 | prssdp = (struct dasd_psf_prssd_data *) cqr->data; | |
409 | memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data)); | |
410 | prssdp->order = PSF_ORDER_PRSSD; | |
411 | prssdp->suborder = 0x0e; /* Read unit address configuration */ | |
412 | /* all other bytes of prssdp must be zero */ | |
413 | ||
414 | ccw = cqr->cpaddr; | |
415 | ccw->cmd_code = DASD_ECKD_CCW_PSF; | |
416 | ccw->count = sizeof(struct dasd_psf_prssd_data); | |
417 | ccw->flags |= CCW_FLAG_CC; | |
418 | ccw->cda = (__u32)(addr_t) prssdp; | |
419 | ||
420 | /* Read Subsystem Data - feature codes */ | |
421 | memset(lcu->uac, 0, sizeof(*(lcu->uac))); | |
422 | ||
423 | ccw++; | |
424 | ccw->cmd_code = DASD_ECKD_CCW_RSSD; | |
425 | ccw->count = sizeof(*(lcu->uac)); | |
426 | ccw->cda = (__u32)(addr_t) lcu->uac; | |
427 | ||
428 | cqr->buildclk = get_clock(); | |
429 | cqr->status = DASD_CQR_FILLED; | |
430 | ||
431 | /* need to unset flag here to detect race with summary unit check */ | |
432 | spin_lock_irqsave(&lcu->lock, flags); | |
433 | lcu->flags &= ~NEED_UAC_UPDATE; | |
434 | spin_unlock_irqrestore(&lcu->lock, flags); | |
435 | ||
436 | do { | |
437 | rc = dasd_sleep_on(cqr); | |
438 | } while (rc && (cqr->retries > 0)); | |
439 | if (rc) { | |
440 | spin_lock_irqsave(&lcu->lock, flags); | |
441 | lcu->flags |= NEED_UAC_UPDATE; | |
442 | spin_unlock_irqrestore(&lcu->lock, flags); | |
443 | } | |
444 | dasd_kfree_request(cqr, cqr->memdev); | |
445 | return rc; | |
446 | } | |
447 | ||
448 | static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu) | |
449 | { | |
450 | unsigned long flags; | |
451 | struct alias_pav_group *pavgroup, *tempgroup; | |
452 | struct dasd_device *device, *tempdev; | |
453 | int i, rc; | |
454 | struct dasd_eckd_private *private; | |
455 | ||
456 | spin_lock_irqsave(&lcu->lock, flags); | |
457 | list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) { | |
458 | list_for_each_entry_safe(device, tempdev, &pavgroup->baselist, | |
459 | alias_list) { | |
460 | list_move(&device->alias_list, &lcu->active_devices); | |
461 | private = (struct dasd_eckd_private *) device->private; | |
462 | private->pavgroup = NULL; | |
463 | } | |
464 | list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist, | |
465 | alias_list) { | |
466 | list_move(&device->alias_list, &lcu->active_devices); | |
467 | private = (struct dasd_eckd_private *) device->private; | |
468 | private->pavgroup = NULL; | |
469 | } | |
470 | list_del(&pavgroup->group); | |
471 | kfree(pavgroup); | |
472 | } | |
473 | spin_unlock_irqrestore(&lcu->lock, flags); | |
474 | ||
475 | rc = read_unit_address_configuration(refdev, lcu); | |
476 | if (rc) | |
477 | return rc; | |
478 | ||
2dedf0d9 SH |
479 | /* need to take cdev lock before lcu lock */ |
480 | spin_lock_irqsave_nested(get_ccwdev_lock(refdev->cdev), flags, | |
481 | CDEV_NESTED_FIRST); | |
482 | spin_lock(&lcu->lock); | |
8e09f215 SW |
483 | lcu->pav = NO_PAV; |
484 | for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) { | |
485 | switch (lcu->uac->unit[i].ua_type) { | |
486 | case UA_BASE_PAV_ALIAS: | |
487 | lcu->pav = BASE_PAV; | |
488 | break; | |
489 | case UA_HYPER_PAV_ALIAS: | |
490 | lcu->pav = HYPER_PAV; | |
491 | break; | |
492 | } | |
493 | if (lcu->pav != NO_PAV) | |
494 | break; | |
495 | } | |
496 | ||
497 | list_for_each_entry_safe(device, tempdev, &lcu->active_devices, | |
498 | alias_list) { | |
2dedf0d9 | 499 | _add_device_to_lcu(lcu, device, refdev); |
8e09f215 | 500 | } |
2dedf0d9 SH |
501 | spin_unlock(&lcu->lock); |
502 | spin_unlock_irqrestore(get_ccwdev_lock(refdev->cdev), flags); | |
8e09f215 SW |
503 | return 0; |
504 | } | |
505 | ||
506 | static void lcu_update_work(struct work_struct *work) | |
507 | { | |
508 | struct alias_lcu *lcu; | |
509 | struct read_uac_work_data *ruac_data; | |
510 | struct dasd_device *device; | |
511 | unsigned long flags; | |
512 | int rc; | |
513 | ||
514 | ruac_data = container_of(work, struct read_uac_work_data, dwork.work); | |
515 | lcu = container_of(ruac_data, struct alias_lcu, ruac_data); | |
516 | device = ruac_data->device; | |
517 | rc = _lcu_update(device, lcu); | |
518 | /* | |
519 | * Need to check flags again, as there could have been another | |
520 | * prepare_update or a new device a new device while we were still | |
521 | * processing the data | |
522 | */ | |
523 | spin_lock_irqsave(&lcu->lock, flags); | |
524 | if (rc || (lcu->flags & NEED_UAC_UPDATE)) { | |
fc19f381 | 525 | DBF_DEV_EVENT(DBF_WARNING, device, "could not update" |
8e09f215 SW |
526 | " alias data in lcu (rc = %d), retry later", rc); |
527 | schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ); | |
528 | } else { | |
529 | lcu->ruac_data.device = NULL; | |
530 | lcu->flags &= ~UPDATE_PENDING; | |
531 | } | |
532 | spin_unlock_irqrestore(&lcu->lock, flags); | |
533 | } | |
534 | ||
535 | static int _schedule_lcu_update(struct alias_lcu *lcu, | |
536 | struct dasd_device *device) | |
537 | { | |
538 | struct dasd_device *usedev = NULL; | |
539 | struct alias_pav_group *group; | |
540 | ||
541 | lcu->flags |= NEED_UAC_UPDATE; | |
542 | if (lcu->ruac_data.device) { | |
543 | /* already scheduled or running */ | |
544 | return 0; | |
545 | } | |
546 | if (device && !list_empty(&device->alias_list)) | |
547 | usedev = device; | |
548 | ||
549 | if (!usedev && !list_empty(&lcu->grouplist)) { | |
550 | group = list_first_entry(&lcu->grouplist, | |
551 | struct alias_pav_group, group); | |
552 | if (!list_empty(&group->baselist)) | |
553 | usedev = list_first_entry(&group->baselist, | |
554 | struct dasd_device, | |
555 | alias_list); | |
556 | else if (!list_empty(&group->aliaslist)) | |
557 | usedev = list_first_entry(&group->aliaslist, | |
558 | struct dasd_device, | |
559 | alias_list); | |
560 | } | |
561 | if (!usedev && !list_empty(&lcu->active_devices)) { | |
562 | usedev = list_first_entry(&lcu->active_devices, | |
563 | struct dasd_device, alias_list); | |
564 | } | |
565 | /* | |
566 | * if we haven't found a proper device yet, give up for now, the next | |
567 | * device that will be set active will trigger an lcu update | |
568 | */ | |
569 | if (!usedev) | |
570 | return -EINVAL; | |
571 | lcu->ruac_data.device = usedev; | |
572 | schedule_delayed_work(&lcu->ruac_data.dwork, 0); | |
573 | return 0; | |
574 | } | |
575 | ||
576 | int dasd_alias_add_device(struct dasd_device *device) | |
577 | { | |
578 | struct dasd_eckd_private *private; | |
579 | struct alias_lcu *lcu; | |
580 | unsigned long flags; | |
581 | int rc; | |
582 | ||
583 | private = (struct dasd_eckd_private *) device->private; | |
584 | lcu = private->lcu; | |
585 | rc = 0; | |
2dedf0d9 SH |
586 | |
587 | /* need to take cdev lock before lcu lock */ | |
588 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
589 | spin_lock(&lcu->lock); | |
8e09f215 | 590 | if (!(lcu->flags & UPDATE_PENDING)) { |
2dedf0d9 | 591 | rc = _add_device_to_lcu(lcu, device, device); |
8e09f215 SW |
592 | if (rc) |
593 | lcu->flags |= UPDATE_PENDING; | |
594 | } | |
595 | if (lcu->flags & UPDATE_PENDING) { | |
596 | list_move(&device->alias_list, &lcu->active_devices); | |
597 | _schedule_lcu_update(lcu, device); | |
598 | } | |
2dedf0d9 SH |
599 | spin_unlock(&lcu->lock); |
600 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); | |
8e09f215 SW |
601 | return rc; |
602 | } | |
603 | ||
501183f2 SH |
604 | int dasd_alias_update_add_device(struct dasd_device *device) |
605 | { | |
606 | struct dasd_eckd_private *private; | |
607 | private = (struct dasd_eckd_private *) device->private; | |
608 | private->lcu->flags |= UPDATE_PENDING; | |
609 | return dasd_alias_add_device(device); | |
610 | } | |
611 | ||
8e09f215 SW |
612 | int dasd_alias_remove_device(struct dasd_device *device) |
613 | { | |
614 | struct dasd_eckd_private *private; | |
615 | struct alias_lcu *lcu; | |
616 | unsigned long flags; | |
617 | ||
618 | private = (struct dasd_eckd_private *) device->private; | |
619 | lcu = private->lcu; | |
f602f6d6 SH |
620 | /* nothing to do if already removed */ |
621 | if (!lcu) | |
622 | return 0; | |
8e09f215 SW |
623 | spin_lock_irqsave(&lcu->lock, flags); |
624 | _remove_device_from_lcu(lcu, device); | |
625 | spin_unlock_irqrestore(&lcu->lock, flags); | |
626 | return 0; | |
627 | } | |
628 | ||
629 | struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device) | |
630 | { | |
631 | ||
632 | struct dasd_device *alias_device; | |
633 | struct alias_pav_group *group; | |
634 | struct alias_lcu *lcu; | |
635 | struct dasd_eckd_private *private, *alias_priv; | |
636 | unsigned long flags; | |
637 | ||
638 | private = (struct dasd_eckd_private *) base_device->private; | |
639 | group = private->pavgroup; | |
640 | lcu = private->lcu; | |
641 | if (!group || !lcu) | |
642 | return NULL; | |
643 | if (lcu->pav == NO_PAV || | |
644 | lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING)) | |
645 | return NULL; | |
b38f27e8 SH |
646 | if (unlikely(!(private->features.feature[8] & 0x01))) { |
647 | /* | |
648 | * PAV enabled but prefix not, very unlikely | |
649 | * seems to be a lost pathgroup | |
650 | * use base device to do IO | |
651 | */ | |
652 | DBF_DEV_EVENT(DBF_ERR, base_device, "%s", | |
653 | "Prefix not enabled with PAV enabled\n"); | |
654 | return NULL; | |
655 | } | |
8e09f215 SW |
656 | |
657 | spin_lock_irqsave(&lcu->lock, flags); | |
658 | alias_device = group->next; | |
659 | if (!alias_device) { | |
660 | if (list_empty(&group->aliaslist)) { | |
661 | spin_unlock_irqrestore(&lcu->lock, flags); | |
662 | return NULL; | |
663 | } else { | |
664 | alias_device = list_first_entry(&group->aliaslist, | |
665 | struct dasd_device, | |
666 | alias_list); | |
667 | } | |
668 | } | |
669 | if (list_is_last(&alias_device->alias_list, &group->aliaslist)) | |
670 | group->next = list_first_entry(&group->aliaslist, | |
671 | struct dasd_device, alias_list); | |
672 | else | |
673 | group->next = list_first_entry(&alias_device->alias_list, | |
674 | struct dasd_device, alias_list); | |
675 | spin_unlock_irqrestore(&lcu->lock, flags); | |
676 | alias_priv = (struct dasd_eckd_private *) alias_device->private; | |
677 | if ((alias_priv->count < private->count) && !alias_device->stopped) | |
678 | return alias_device; | |
679 | else | |
680 | return NULL; | |
681 | } | |
682 | ||
683 | /* | |
684 | * Summary unit check handling depends on the way alias devices | |
685 | * are handled so it is done here rather then in dasd_eckd.c | |
686 | */ | |
687 | static int reset_summary_unit_check(struct alias_lcu *lcu, | |
688 | struct dasd_device *device, | |
689 | char reason) | |
690 | { | |
691 | struct dasd_ccw_req *cqr; | |
692 | int rc = 0; | |
f3eb5384 | 693 | struct ccw1 *ccw; |
8e09f215 SW |
694 | |
695 | cqr = lcu->rsu_cqr; | |
696 | strncpy((char *) &cqr->magic, "ECKD", 4); | |
697 | ASCEBC((char *) &cqr->magic, 4); | |
f3eb5384 SW |
698 | ccw = cqr->cpaddr; |
699 | ccw->cmd_code = DASD_ECKD_CCW_RSCK; | |
700 | ccw->flags = 0 ; | |
701 | ccw->count = 16; | |
702 | ccw->cda = (__u32)(addr_t) cqr->data; | |
8e09f215 SW |
703 | ((char *)cqr->data)[0] = reason; |
704 | ||
705 | clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); | |
706 | cqr->retries = 255; /* set retry counter to enable basic ERP */ | |
707 | cqr->startdev = device; | |
708 | cqr->memdev = device; | |
709 | cqr->block = NULL; | |
710 | cqr->expires = 5 * HZ; | |
711 | cqr->buildclk = get_clock(); | |
712 | cqr->status = DASD_CQR_FILLED; | |
713 | ||
714 | rc = dasd_sleep_on_immediatly(cqr); | |
715 | return rc; | |
716 | } | |
717 | ||
718 | static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu) | |
719 | { | |
720 | struct alias_pav_group *pavgroup; | |
721 | struct dasd_device *device; | |
722 | struct dasd_eckd_private *private; | |
2dedf0d9 | 723 | unsigned long flags; |
8e09f215 SW |
724 | |
725 | /* active and inactive list can contain alias as well as base devices */ | |
726 | list_for_each_entry(device, &lcu->active_devices, alias_list) { | |
727 | private = (struct dasd_eckd_private *) device->private; | |
2dedf0d9 SH |
728 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); |
729 | if (private->uid.type != UA_BASE_DEVICE) { | |
730 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), | |
731 | flags); | |
8e09f215 | 732 | continue; |
2dedf0d9 SH |
733 | } |
734 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); | |
8e09f215 SW |
735 | dasd_schedule_block_bh(device->block); |
736 | dasd_schedule_device_bh(device); | |
737 | } | |
738 | list_for_each_entry(device, &lcu->inactive_devices, alias_list) { | |
739 | private = (struct dasd_eckd_private *) device->private; | |
2dedf0d9 SH |
740 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); |
741 | if (private->uid.type != UA_BASE_DEVICE) { | |
742 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), | |
743 | flags); | |
8e09f215 | 744 | continue; |
2dedf0d9 SH |
745 | } |
746 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); | |
8e09f215 SW |
747 | dasd_schedule_block_bh(device->block); |
748 | dasd_schedule_device_bh(device); | |
749 | } | |
750 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { | |
751 | list_for_each_entry(device, &pavgroup->baselist, alias_list) { | |
752 | dasd_schedule_block_bh(device->block); | |
753 | dasd_schedule_device_bh(device); | |
754 | } | |
755 | } | |
756 | } | |
757 | ||
758 | static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu) | |
759 | { | |
760 | struct alias_pav_group *pavgroup; | |
761 | struct dasd_device *device, *temp; | |
762 | struct dasd_eckd_private *private; | |
763 | int rc; | |
764 | unsigned long flags; | |
765 | LIST_HEAD(active); | |
766 | ||
767 | /* | |
768 | * Problem here ist that dasd_flush_device_queue may wait | |
769 | * for termination of a request to complete. We can't keep | |
770 | * the lcu lock during that time, so we must assume that | |
771 | * the lists may have changed. | |
772 | * Idea: first gather all active alias devices in a separate list, | |
773 | * then flush the first element of this list unlocked, and afterwards | |
774 | * check if it is still on the list before moving it to the | |
775 | * active_devices list. | |
776 | */ | |
777 | ||
778 | spin_lock_irqsave(&lcu->lock, flags); | |
779 | list_for_each_entry_safe(device, temp, &lcu->active_devices, | |
780 | alias_list) { | |
781 | private = (struct dasd_eckd_private *) device->private; | |
782 | if (private->uid.type == UA_BASE_DEVICE) | |
783 | continue; | |
784 | list_move(&device->alias_list, &active); | |
785 | } | |
786 | ||
787 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { | |
788 | list_splice_init(&pavgroup->aliaslist, &active); | |
789 | } | |
790 | while (!list_empty(&active)) { | |
791 | device = list_first_entry(&active, struct dasd_device, | |
792 | alias_list); | |
793 | spin_unlock_irqrestore(&lcu->lock, flags); | |
794 | rc = dasd_flush_device_queue(device); | |
795 | spin_lock_irqsave(&lcu->lock, flags); | |
796 | /* | |
797 | * only move device around if it wasn't moved away while we | |
798 | * were waiting for the flush | |
799 | */ | |
800 | if (device == list_first_entry(&active, | |
801 | struct dasd_device, alias_list)) | |
802 | list_move(&device->alias_list, &lcu->active_devices); | |
803 | } | |
804 | spin_unlock_irqrestore(&lcu->lock, flags); | |
805 | } | |
806 | ||
a806170e HC |
807 | static void __stop_device_on_lcu(struct dasd_device *device, |
808 | struct dasd_device *pos) | |
809 | { | |
810 | /* If pos == device then device is already locked! */ | |
811 | if (pos == device) { | |
eb6e199b | 812 | dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); |
a806170e HC |
813 | return; |
814 | } | |
815 | spin_lock(get_ccwdev_lock(pos->cdev)); | |
eb6e199b | 816 | dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); |
a806170e HC |
817 | spin_unlock(get_ccwdev_lock(pos->cdev)); |
818 | } | |
819 | ||
8e09f215 SW |
820 | /* |
821 | * This function is called in interrupt context, so the | |
822 | * cdev lock for device is already locked! | |
823 | */ | |
824 | static void _stop_all_devices_on_lcu(struct alias_lcu *lcu, | |
825 | struct dasd_device *device) | |
826 | { | |
827 | struct alias_pav_group *pavgroup; | |
828 | struct dasd_device *pos; | |
829 | ||
a806170e HC |
830 | list_for_each_entry(pos, &lcu->active_devices, alias_list) |
831 | __stop_device_on_lcu(device, pos); | |
832 | list_for_each_entry(pos, &lcu->inactive_devices, alias_list) | |
833 | __stop_device_on_lcu(device, pos); | |
8e09f215 | 834 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { |
a806170e HC |
835 | list_for_each_entry(pos, &pavgroup->baselist, alias_list) |
836 | __stop_device_on_lcu(device, pos); | |
837 | list_for_each_entry(pos, &pavgroup->aliaslist, alias_list) | |
838 | __stop_device_on_lcu(device, pos); | |
8e09f215 SW |
839 | } |
840 | } | |
841 | ||
842 | static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu) | |
843 | { | |
844 | struct alias_pav_group *pavgroup; | |
845 | struct dasd_device *device; | |
846 | unsigned long flags; | |
847 | ||
848 | list_for_each_entry(device, &lcu->active_devices, alias_list) { | |
849 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 850 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
851 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); |
852 | } | |
853 | ||
854 | list_for_each_entry(device, &lcu->inactive_devices, alias_list) { | |
855 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 856 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
857 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); |
858 | } | |
859 | ||
860 | list_for_each_entry(pavgroup, &lcu->grouplist, group) { | |
861 | list_for_each_entry(device, &pavgroup->baselist, alias_list) { | |
862 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 863 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
864 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), |
865 | flags); | |
866 | } | |
867 | list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { | |
868 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b | 869 | dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); |
8e09f215 SW |
870 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), |
871 | flags); | |
872 | } | |
873 | } | |
874 | } | |
875 | ||
876 | static void summary_unit_check_handling_work(struct work_struct *work) | |
877 | { | |
878 | struct alias_lcu *lcu; | |
879 | struct summary_unit_check_work_data *suc_data; | |
880 | unsigned long flags; | |
881 | struct dasd_device *device; | |
882 | ||
883 | suc_data = container_of(work, struct summary_unit_check_work_data, | |
884 | worker); | |
885 | lcu = container_of(suc_data, struct alias_lcu, suc_data); | |
886 | device = suc_data->device; | |
887 | ||
888 | /* 1. flush alias devices */ | |
889 | flush_all_alias_devices_on_lcu(lcu); | |
890 | ||
891 | /* 2. reset summary unit check */ | |
892 | spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); | |
eb6e199b SW |
893 | dasd_device_remove_stop_bits(device, |
894 | (DASD_STOPPED_SU | DASD_STOPPED_PENDING)); | |
8e09f215 SW |
895 | spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); |
896 | reset_summary_unit_check(lcu, device, suc_data->reason); | |
897 | ||
898 | spin_lock_irqsave(&lcu->lock, flags); | |
899 | _unstop_all_devices_on_lcu(lcu); | |
900 | _restart_all_base_devices_on_lcu(lcu); | |
901 | /* 3. read new alias configuration */ | |
902 | _schedule_lcu_update(lcu, device); | |
903 | lcu->suc_data.device = NULL; | |
904 | spin_unlock_irqrestore(&lcu->lock, flags); | |
905 | } | |
906 | ||
907 | /* | |
908 | * note: this will be called from int handler context (cdev locked) | |
909 | */ | |
910 | void dasd_alias_handle_summary_unit_check(struct dasd_device *device, | |
911 | struct irb *irb) | |
912 | { | |
913 | struct alias_lcu *lcu; | |
914 | char reason; | |
915 | struct dasd_eckd_private *private; | |
f3eb5384 | 916 | char *sense; |
8e09f215 SW |
917 | |
918 | private = (struct dasd_eckd_private *) device->private; | |
919 | ||
f3eb5384 SW |
920 | sense = dasd_get_sense(irb); |
921 | if (sense) { | |
922 | reason = sense[8]; | |
923 | DBF_DEV_EVENT(DBF_NOTICE, device, "%s %x", | |
924 | "eckd handle summary unit check: reason", reason); | |
925 | } else { | |
926 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", | |
927 | "eckd handle summary unit check:" | |
928 | " no reason code available"); | |
929 | return; | |
930 | } | |
8e09f215 SW |
931 | |
932 | lcu = private->lcu; | |
933 | if (!lcu) { | |
fc19f381 | 934 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", |
8e09f215 SW |
935 | "device not ready to handle summary" |
936 | " unit check (no lcu structure)"); | |
937 | return; | |
938 | } | |
939 | spin_lock(&lcu->lock); | |
940 | _stop_all_devices_on_lcu(lcu, device); | |
941 | /* prepare for lcu_update */ | |
942 | private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING; | |
943 | /* If this device is about to be removed just return and wait for | |
944 | * the next interrupt on a different device | |
945 | */ | |
946 | if (list_empty(&device->alias_list)) { | |
fc19f381 | 947 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", |
8e09f215 SW |
948 | "device is in offline processing," |
949 | " don't do summary unit check handling"); | |
950 | spin_unlock(&lcu->lock); | |
951 | return; | |
952 | } | |
953 | if (lcu->suc_data.device) { | |
954 | /* already scheduled or running */ | |
fc19f381 | 955 | DBF_DEV_EVENT(DBF_WARNING, device, "%s", |
8e09f215 SW |
956 | "previous instance of summary unit check worker" |
957 | " still pending"); | |
958 | spin_unlock(&lcu->lock); | |
959 | return ; | |
960 | } | |
961 | lcu->suc_data.reason = reason; | |
962 | lcu->suc_data.device = device; | |
963 | spin_unlock(&lcu->lock); | |
964 | schedule_work(&lcu->suc_data.worker); | |
965 | }; |