1// SPDX-License-Identifier: GPL-2.0 2/* 3 * PAV alias management for the DASD ECKD discipline 4 * 5 * Copyright IBM Corp. 2007 6 * Author(s): Stefan Weinhuber <wein@de.ibm.com> 7 */ 8 9#define KMSG_COMPONENT "dasd-eckd" 10 11#include <linux/list.h> 12#include <linux/slab.h> 13#include <asm/ebcdic.h> 14#include "dasd_int.h" 15#include "dasd_eckd.h" 16 17#ifdef PRINTK_HEADER 18#undef PRINTK_HEADER 19#endif /* PRINTK_HEADER */ 20#define PRINTK_HEADER "dasd(eckd):" 21 22 23/* 24 * General concept of alias management: 25 * - PAV and DASD alias management is specific to the eckd discipline. 26 * - A device is connected to an lcu as long as the device exists. 27 * dasd_alias_make_device_known_to_lcu will be called wenn the 28 * device is checked by the eckd discipline and 29 * dasd_alias_disconnect_device_from_lcu will be called 30 * before the device is deleted. 31 * - The dasd_alias_add_device / dasd_alias_remove_device 32 * functions mark the point when a device is 'ready for service'. 33 * - A summary unit check is a rare occasion, but it is mandatory to 34 * support it. It requires some complex recovery actions before the 35 * devices can be used again (see dasd_alias_handle_summary_unit_check). 36 * - dasd_alias_get_start_dev will find an alias device that can be used 37 * instead of the base device and does some (very simple) load balancing. 38 * This is the function that gets called for each I/O, so when improving 39 * something, this function should get faster or better, the rest has just 40 * to be correct. 41 */ 42 43 44static void summary_unit_check_handling_work(struct work_struct *); 45static void lcu_update_work(struct work_struct *); 46static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *); 47 48static struct alias_root aliastree = { 49 .serverlist = LIST_HEAD_INIT(aliastree.serverlist), 50 .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock), 51}; 52 53static struct alias_server *_find_server(struct dasd_uid *uid) 54{ 55 struct alias_server *pos; 56 list_for_each_entry(pos, &aliastree.serverlist, server) { 57 if (!strncmp(pos->uid.vendor, uid->vendor, 58 sizeof(uid->vendor)) 59 && !strncmp(pos->uid.serial, uid->serial, 60 sizeof(uid->serial))) 61 return pos; 62 } 63 return NULL; 64} 65 66static struct alias_lcu *_find_lcu(struct alias_server *server, 67 struct dasd_uid *uid) 68{ 69 struct alias_lcu *pos; 70 list_for_each_entry(pos, &server->lculist, lcu) { 71 if (pos->uid.ssid == uid->ssid) 72 return pos; 73 } 74 return NULL; 75} 76 77static struct alias_pav_group *_find_group(struct alias_lcu *lcu, 78 struct dasd_uid *uid) 79{ 80 struct alias_pav_group *pos; 81 __u8 search_unit_addr; 82 83 /* for hyper pav there is only one group */ 84 if (lcu->pav == HYPER_PAV) { 85 if (list_empty(&lcu->grouplist)) 86 return NULL; 87 else 88 return list_first_entry(&lcu->grouplist, 89 struct alias_pav_group, group); 90 } 91 92 /* for base pav we have to find the group that matches the base */ 93 if (uid->type == UA_BASE_DEVICE) 94 search_unit_addr = uid->real_unit_addr; 95 else 96 search_unit_addr = uid->base_unit_addr; 97 list_for_each_entry(pos, &lcu->grouplist, group) { 98 if (pos->uid.base_unit_addr == search_unit_addr && 99 !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit))) 100 return pos; 101 } 102 return NULL; 103} 104 105static struct alias_server *_allocate_server(struct dasd_uid *uid) 106{ 107 struct alias_server *server; 108 109 server = kzalloc(sizeof(*server), GFP_KERNEL); 110 if (!server) 111 return ERR_PTR(-ENOMEM); 112 memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor)); 113 memcpy(server->uid.serial, uid->serial, sizeof(uid->serial)); 114 INIT_LIST_HEAD(&server->server); 115 INIT_LIST_HEAD(&server->lculist); 116 return server; 117} 118 119static void _free_server(struct alias_server *server) 120{ 121 kfree(server); 122} 123 124static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid) 125{ 126 struct alias_lcu *lcu; 127 128 lcu = kzalloc(sizeof(*lcu), GFP_KERNEL); 129 if (!lcu) 130 return ERR_PTR(-ENOMEM); 131 lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA); 132 if (!lcu->uac) 133 goto out_err1; 134 lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA); 135 if (!lcu->rsu_cqr) 136 goto out_err2; 137 lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1), 138 GFP_KERNEL | GFP_DMA); 139 if (!lcu->rsu_cqr->cpaddr) 140 goto out_err3; 141 lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA); 142 if (!lcu->rsu_cqr->data) 143 goto out_err4; 144 145 memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor)); 146 memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial)); 147 lcu->uid.ssid = uid->ssid; 148 lcu->pav = NO_PAV; 149 lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING; 150 INIT_LIST_HEAD(&lcu->lcu); 151 INIT_LIST_HEAD(&lcu->inactive_devices); 152 INIT_LIST_HEAD(&lcu->active_devices); 153 INIT_LIST_HEAD(&lcu->grouplist); 154 INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work); 155 INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work); 156 spin_lock_init(&lcu->lock); 157 init_completion(&lcu->lcu_setup); 158 return lcu; 159 160out_err4: 161 kfree(lcu->rsu_cqr->cpaddr); 162out_err3: 163 kfree(lcu->rsu_cqr); 164out_err2: 165 kfree(lcu->uac); 166out_err1: 167 kfree(lcu); 168 return ERR_PTR(-ENOMEM); 169} 170 171static void _free_lcu(struct alias_lcu *lcu) 172{ 173 kfree(lcu->rsu_cqr->data); 174 kfree(lcu->rsu_cqr->cpaddr); 175 kfree(lcu->rsu_cqr); 176 kfree(lcu->uac); 177 kfree(lcu); 178} 179 180/* 181 * This is the function that will allocate all the server and lcu data, 182 * so this function must be called first for a new device. 183 * If the return value is 1, the lcu was already known before, if it 184 * is 0, this is a new lcu. 185 * Negative return code indicates that something went wrong (e.g. -ENOMEM) 186 */ 187int dasd_alias_make_device_known_to_lcu(struct dasd_device *device) 188{ 189 struct dasd_eckd_private *private = device->private; 190 unsigned long flags; 191 struct alias_server *server, *newserver; 192 struct alias_lcu *lcu, *newlcu; 193 struct dasd_uid uid; 194 195 device->discipline->get_uid(device, &uid); 196 spin_lock_irqsave(&aliastree.lock, flags); 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 } else { 209 /* someone was faster */ 210 _free_server(newserver); 211 } 212 } 213 214 lcu = _find_lcu(server, &uid); 215 if (!lcu) { 216 spin_unlock_irqrestore(&aliastree.lock, flags); 217 newlcu = _allocate_lcu(&uid); 218 if (IS_ERR(newlcu)) 219 return PTR_ERR(newlcu); 220 spin_lock_irqsave(&aliastree.lock, flags); 221 lcu = _find_lcu(server, &uid); 222 if (!lcu) { 223 list_add(&newlcu->lcu, &server->lculist); 224 lcu = newlcu; 225 } else { 226 /* someone was faster */ 227 _free_lcu(newlcu); 228 } 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 0; 237} 238 239/* 240 * This function removes a device from the scope of alias management. 241 * The complicated part is to make sure that it is not in use by 242 * any of the workers. If necessary cancel the work. 243 */ 244void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) 245{ 246 struct dasd_eckd_private *private = device->private; 247 unsigned long flags; 248 struct alias_lcu *lcu; 249 struct alias_server *server; 250 int was_pending; 251 struct dasd_uid uid; 252 253 lcu = private->lcu; 254 /* nothing to do if already disconnected */ 255 if (!lcu) 256 return; 257 device->discipline->get_uid(device, &uid); 258 spin_lock_irqsave(&lcu->lock, flags); 259 /* make sure that the workers don't use this device */ 260 if (device == lcu->suc_data.device) { 261 spin_unlock_irqrestore(&lcu->lock, flags); 262 cancel_work_sync(&lcu->suc_data.worker); 263 spin_lock_irqsave(&lcu->lock, flags); 264 if (device == lcu->suc_data.device) { 265 dasd_put_device(device); 266 lcu->suc_data.device = NULL; 267 } 268 } 269 was_pending = 0; 270 if (device == lcu->ruac_data.device) { 271 spin_unlock_irqrestore(&lcu->lock, flags); 272 was_pending = 1; 273 cancel_delayed_work_sync(&lcu->ruac_data.dwork); 274 spin_lock_irqsave(&lcu->lock, flags); 275 if (device == lcu->ruac_data.device) { 276 dasd_put_device(device); 277 lcu->ruac_data.device = NULL; 278 } 279 } 280 private->lcu = NULL; 281 spin_unlock_irqrestore(&lcu->lock, flags); 282 283 spin_lock_irqsave(&aliastree.lock, flags); 284 spin_lock(&lcu->lock); 285 list_del_init(&device->alias_list); 286 if (list_empty(&lcu->grouplist) && 287 list_empty(&lcu->active_devices) && 288 list_empty(&lcu->inactive_devices)) { 289 list_del(&lcu->lcu); 290 spin_unlock(&lcu->lock); 291 _free_lcu(lcu); 292 lcu = NULL; 293 } else { 294 if (was_pending) 295 _schedule_lcu_update(lcu, NULL); 296 spin_unlock(&lcu->lock); 297 } 298 server = _find_server(&uid); 299 if (server && list_empty(&server->lculist)) { 300 list_del(&server->server); 301 _free_server(server); 302 } 303 spin_unlock_irqrestore(&aliastree.lock, flags); 304} 305 306/* 307 * This function assumes that the unit address configuration stored 308 * in the lcu is up to date and will update the device uid before 309 * adding it to a pav group. 310 */ 311 312static int _add_device_to_lcu(struct alias_lcu *lcu, 313 struct dasd_device *device, 314 struct dasd_device *pos) 315{ 316 317 struct dasd_eckd_private *private = device->private; 318 struct alias_pav_group *group; 319 struct dasd_uid uid; 320 321 spin_lock(get_ccwdev_lock(device->cdev)); 322 private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type; 323 private->uid.base_unit_addr = 324 lcu->uac->unit[private->uid.real_unit_addr].base_ua; 325 uid = private->uid; 326 spin_unlock(get_ccwdev_lock(device->cdev)); 327 /* if we have no PAV anyway, we don't need to bother with PAV groups */ 328 if (lcu->pav == NO_PAV) { 329 list_move(&device->alias_list, &lcu->active_devices); 330 return 0; 331 } 332 group = _find_group(lcu, &uid); 333 if (!group) { 334 group = kzalloc(sizeof(*group), GFP_ATOMIC); 335 if (!group) 336 return -ENOMEM; 337 memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor)); 338 memcpy(group->uid.serial, uid.serial, sizeof(uid.serial)); 339 group->uid.ssid = uid.ssid; 340 if (uid.type == UA_BASE_DEVICE) 341 group->uid.base_unit_addr = uid.real_unit_addr; 342 else 343 group->uid.base_unit_addr = uid.base_unit_addr; 344 memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit)); 345 INIT_LIST_HEAD(&group->group); 346 INIT_LIST_HEAD(&group->baselist); 347 INIT_LIST_HEAD(&group->aliaslist); 348 list_add(&group->group, &lcu->grouplist); 349 } 350 if (uid.type == UA_BASE_DEVICE) 351 list_move(&device->alias_list, &group->baselist); 352 else 353 list_move(&device->alias_list, &group->aliaslist); 354 private->pavgroup = group; 355 return 0; 356}; 357 358static void _remove_device_from_lcu(struct alias_lcu *lcu, 359 struct dasd_device *device) 360{ 361 struct dasd_eckd_private *private = device->private; 362 struct alias_pav_group *group; 363 364 list_move(&device->alias_list, &lcu->inactive_devices); 365 group = private->pavgroup; 366 if (!group) 367 return; 368 private->pavgroup = NULL; 369 if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) { 370 list_del(&group->group); 371 kfree(group); 372 return; 373 } 374 if (group->next == device) 375 group->next = NULL; 376}; 377 378static int 379suborder_not_supported(struct dasd_ccw_req *cqr) 380{ 381 char *sense; 382 char reason; 383 char msg_format; 384 char msg_no; 385 386 /* 387 * intrc values ENODEV, ENOLINK and EPERM 388 * will be optained from sleep_on to indicate that no 389 * IO operation can be started 390 */ 391 if (cqr->intrc == -ENODEV) 392 return 1; 393 394 if (cqr->intrc == -ENOLINK) 395 return 1; 396 397 if (cqr->intrc == -EPERM) 398 return 1; 399 400 sense = dasd_get_sense(&cqr->irb); 401 if (!sense) 402 return 0; 403 404 reason = sense[0]; 405 msg_format = (sense[7] & 0xF0); 406 msg_no = (sense[7] & 0x0F); 407 408 /* command reject, Format 0 MSG 4 - invalid parameter */ 409 if ((reason == 0x80) && (msg_format == 0x00) && (msg_no == 0x04)) 410 return 1; 411 412 return 0; 413} 414 415static int read_unit_address_configuration(struct dasd_device *device, 416 struct alias_lcu *lcu) 417{ 418 struct dasd_psf_prssd_data *prssdp; 419 struct dasd_ccw_req *cqr; 420 struct ccw1 *ccw; 421 int rc; 422 unsigned long flags; 423 424 cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */, 425 (sizeof(struct dasd_psf_prssd_data)), 426 device, NULL); 427 if (IS_ERR(cqr)) 428 return PTR_ERR(cqr); 429 cqr->startdev = device; 430 cqr->memdev = device; 431 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); 432 cqr->retries = 10; 433 cqr->expires = 20 * HZ; 434 435 /* Prepare for Read Subsystem Data */ 436 prssdp = (struct dasd_psf_prssd_data *) cqr->data; 437 memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data)); 438 prssdp->order = PSF_ORDER_PRSSD; 439 prssdp->suborder = 0x0e; /* Read unit address configuration */ 440 /* all other bytes of prssdp must be zero */ 441 442 ccw = cqr->cpaddr; 443 ccw->cmd_code = DASD_ECKD_CCW_PSF; 444 ccw->count = sizeof(struct dasd_psf_prssd_data); 445 ccw->flags |= CCW_FLAG_CC; 446 ccw->cda = (__u32)virt_to_phys(prssdp); 447 448 /* Read Subsystem Data - feature codes */ 449 memset(lcu->uac, 0, sizeof(*(lcu->uac))); 450 451 ccw++; 452 ccw->cmd_code = DASD_ECKD_CCW_RSSD; 453 ccw->count = sizeof(*(lcu->uac)); 454 ccw->cda = (__u32)virt_to_phys(lcu->uac); 455 456 cqr->buildclk = get_tod_clock(); 457 cqr->status = DASD_CQR_FILLED; 458 459 /* need to unset flag here to detect race with summary unit check */ 460 spin_lock_irqsave(&lcu->lock, flags); 461 lcu->flags &= ~NEED_UAC_UPDATE; 462 spin_unlock_irqrestore(&lcu->lock, flags); 463 464 rc = dasd_sleep_on(cqr); 465 if (!rc) 466 goto out; 467 468 if (suborder_not_supported(cqr)) { 469 /* suborder not supported or device unusable for IO */ 470 rc = -EOPNOTSUPP; 471 } else { 472 /* IO failed but should be retried */ 473 spin_lock_irqsave(&lcu->lock, flags); 474 lcu->flags |= NEED_UAC_UPDATE; 475 spin_unlock_irqrestore(&lcu->lock, flags); 476 } 477out: 478 dasd_sfree_request(cqr, cqr->memdev); 479 return rc; 480} 481 482static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu) 483{ 484 unsigned long flags; 485 struct alias_pav_group *pavgroup, *tempgroup; 486 struct dasd_device *device, *tempdev; 487 int i, rc; 488 struct dasd_eckd_private *private; 489 490 spin_lock_irqsave(&lcu->lock, flags); 491 list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) { 492 list_for_each_entry_safe(device, tempdev, &pavgroup->baselist, 493 alias_list) { 494 list_move(&device->alias_list, &lcu->active_devices); 495 private = device->private; 496 private->pavgroup = NULL; 497 } 498 list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist, 499 alias_list) { 500 list_move(&device->alias_list, &lcu->active_devices); 501 private = device->private; 502 private->pavgroup = NULL; 503 } 504 list_del(&pavgroup->group); 505 kfree(pavgroup); 506 } 507 spin_unlock_irqrestore(&lcu->lock, flags); 508 509 rc = read_unit_address_configuration(refdev, lcu); 510 if (rc) 511 return rc; 512 513 spin_lock_irqsave(&lcu->lock, flags); 514 /* 515 * there is another update needed skip the remaining handling 516 * the data might already be outdated 517 * but especially do not add the device to an LCU with pending 518 * update 519 */ 520 if (lcu->flags & NEED_UAC_UPDATE) 521 goto out; 522 lcu->pav = NO_PAV; 523 for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) { 524 switch (lcu->uac->unit[i].ua_type) { 525 case UA_BASE_PAV_ALIAS: 526 lcu->pav = BASE_PAV; 527 break; 528 case UA_HYPER_PAV_ALIAS: 529 lcu->pav = HYPER_PAV; 530 break; 531 } 532 if (lcu->pav != NO_PAV) 533 break; 534 } 535 536 list_for_each_entry_safe(device, tempdev, &lcu->active_devices, 537 alias_list) { 538 _add_device_to_lcu(lcu, device, refdev); 539 } 540out: 541 spin_unlock_irqrestore(&lcu->lock, flags); 542 return 0; 543} 544 545static void lcu_update_work(struct work_struct *work) 546{ 547 struct alias_lcu *lcu; 548 struct read_uac_work_data *ruac_data; 549 struct dasd_device *device; 550 unsigned long flags; 551 int rc; 552 553 ruac_data = container_of(work, struct read_uac_work_data, dwork.work); 554 lcu = container_of(ruac_data, struct alias_lcu, ruac_data); 555 device = ruac_data->device; 556 rc = _lcu_update(device, lcu); 557 /* 558 * Need to check flags again, as there could have been another 559 * prepare_update or a new device a new device while we were still 560 * processing the data 561 */ 562 spin_lock_irqsave(&lcu->lock, flags); 563 if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) { 564 DBF_DEV_EVENT(DBF_WARNING, device, "could not update" 565 " alias data in lcu (rc = %d), retry later", rc); 566 if (!schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ)) 567 dasd_put_device(device); 568 } else { 569 dasd_put_device(device); 570 lcu->ruac_data.device = NULL; 571 lcu->flags &= ~UPDATE_PENDING; 572 } 573 spin_unlock_irqrestore(&lcu->lock, flags); 574} 575 576static int _schedule_lcu_update(struct alias_lcu *lcu, 577 struct dasd_device *device) 578{ 579 struct dasd_device *usedev = NULL; 580 struct alias_pav_group *group; 581 582 lcu->flags |= NEED_UAC_UPDATE; 583 if (lcu->ruac_data.device) { 584 /* already scheduled or running */ 585 return 0; 586 } 587 if (device && !list_empty(&device->alias_list)) 588 usedev = device; 589 590 if (!usedev && !list_empty(&lcu->grouplist)) { 591 group = list_first_entry(&lcu->grouplist, 592 struct alias_pav_group, group); 593 if (!list_empty(&group->baselist)) 594 usedev = list_first_entry(&group->baselist, 595 struct dasd_device, 596 alias_list); 597 else if (!list_empty(&group->aliaslist)) 598 usedev = list_first_entry(&group->aliaslist, 599 struct dasd_device, 600 alias_list); 601 } 602 if (!usedev && !list_empty(&lcu->active_devices)) { 603 usedev = list_first_entry(&lcu->active_devices, 604 struct dasd_device, alias_list); 605 } 606 /* 607 * if we haven't found a proper device yet, give up for now, the next 608 * device that will be set active will trigger an lcu update 609 */ 610 if (!usedev) 611 return -EINVAL; 612 dasd_get_device(usedev); 613 lcu->ruac_data.device = usedev; 614 if (!schedule_delayed_work(&lcu->ruac_data.dwork, 0)) 615 dasd_put_device(usedev); 616 return 0; 617} 618 619int dasd_alias_add_device(struct dasd_device *device) 620{ 621 struct dasd_eckd_private *private = device->private; 622 __u8 uaddr = private->uid.real_unit_addr; 623 struct alias_lcu *lcu = private->lcu; 624 unsigned long flags; 625 int rc; 626 627 rc = 0; 628 spin_lock_irqsave(&lcu->lock, flags); 629 /* 630 * Check if device and lcu type differ. If so, the uac data may be 631 * outdated and needs to be updated. 632 */ 633 if (private->uid.type != lcu->uac->unit[uaddr].ua_type) { 634 lcu->flags |= UPDATE_PENDING; 635 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 636 "uid type mismatch - trigger rescan"); 637 } 638 if (!(lcu->flags & UPDATE_PENDING)) { 639 rc = _add_device_to_lcu(lcu, device, device); 640 if (rc) 641 lcu->flags |= UPDATE_PENDING; 642 } 643 if (lcu->flags & UPDATE_PENDING) { 644 list_move(&device->alias_list, &lcu->active_devices); 645 private->pavgroup = NULL; 646 _schedule_lcu_update(lcu, device); 647 } 648 spin_unlock_irqrestore(&lcu->lock, flags); 649 return rc; 650} 651 652int dasd_alias_update_add_device(struct dasd_device *device) 653{ 654 struct dasd_eckd_private *private = device->private; 655 656 private->lcu->flags |= UPDATE_PENDING; 657 return dasd_alias_add_device(device); 658} 659 660int dasd_alias_remove_device(struct dasd_device *device) 661{ 662 struct dasd_eckd_private *private = device->private; 663 struct alias_lcu *lcu = private->lcu; 664 unsigned long flags; 665 666 /* nothing to do if already removed */ 667 if (!lcu) 668 return 0; 669 spin_lock_irqsave(&lcu->lock, flags); 670 _remove_device_from_lcu(lcu, device); 671 spin_unlock_irqrestore(&lcu->lock, flags); 672 return 0; 673} 674 675struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device) 676{ 677 struct dasd_eckd_private *alias_priv, *private = base_device->private; 678 struct alias_lcu *lcu = private->lcu; 679 struct dasd_device *alias_device; 680 struct alias_pav_group *group; 681 unsigned long flags; 682 683 if (!lcu) 684 return NULL; 685 if (lcu->pav == NO_PAV || 686 lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING)) 687 return NULL; 688 if (unlikely(!(private->features.feature[8] & 0x01))) { 689 /* 690 * PAV enabled but prefix not, very unlikely 691 * seems to be a lost pathgroup 692 * use base device to do IO 693 */ 694 DBF_DEV_EVENT(DBF_ERR, base_device, "%s", 695 "Prefix not enabled with PAV enabled\n"); 696 return NULL; 697 } 698 699 spin_lock_irqsave(&lcu->lock, flags); 700 group = private->pavgroup; 701 if (!group) { 702 spin_unlock_irqrestore(&lcu->lock, flags); 703 return NULL; 704 } 705 alias_device = group->next; 706 if (!alias_device) { 707 if (list_empty(&group->aliaslist)) { 708 spin_unlock_irqrestore(&lcu->lock, flags); 709 return NULL; 710 } else { 711 alias_device = list_first_entry(&group->aliaslist, 712 struct dasd_device, 713 alias_list); 714 } 715 } 716 if (list_is_last(&alias_device->alias_list, &group->aliaslist)) 717 group->next = list_first_entry(&group->aliaslist, 718 struct dasd_device, alias_list); 719 else 720 group->next = list_first_entry(&alias_device->alias_list, 721 struct dasd_device, alias_list); 722 spin_unlock_irqrestore(&lcu->lock, flags); 723 alias_priv = alias_device->private; 724 if ((alias_priv->count < private->count) && !alias_device->stopped && 725 !test_bit(DASD_FLAG_OFFLINE, &alias_device->flags)) 726 return alias_device; 727 else 728 return NULL; 729} 730 731/* 732 * Summary unit check handling depends on the way alias devices 733 * are handled so it is done here rather then in dasd_eckd.c 734 */ 735static int reset_summary_unit_check(struct alias_lcu *lcu, 736 struct dasd_device *device, 737 char reason) 738{ 739 struct dasd_ccw_req *cqr; 740 int rc = 0; 741 struct ccw1 *ccw; 742 743 cqr = lcu->rsu_cqr; 744 memcpy((char *) &cqr->magic, "ECKD", 4); 745 ASCEBC((char *) &cqr->magic, 4); 746 ccw = cqr->cpaddr; 747 ccw->cmd_code = DASD_ECKD_CCW_RSCK; 748 ccw->flags = CCW_FLAG_SLI; 749 ccw->count = 16; 750 ccw->cda = (__u32)virt_to_phys(cqr->data); 751 ((char *)cqr->data)[0] = reason; 752 753 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); 754 cqr->retries = 255; /* set retry counter to enable basic ERP */ 755 cqr->startdev = device; 756 cqr->memdev = device; 757 cqr->block = NULL; 758 cqr->expires = 5 * HZ; 759 cqr->buildclk = get_tod_clock(); 760 cqr->status = DASD_CQR_FILLED; 761 762 rc = dasd_sleep_on_immediatly(cqr); 763 return rc; 764} 765 766static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu) 767{ 768 struct alias_pav_group *pavgroup; 769 struct dasd_device *device; 770 struct dasd_eckd_private *private; 771 772 /* active and inactive list can contain alias as well as base devices */ 773 list_for_each_entry(device, &lcu->active_devices, alias_list) { 774 private = device->private; 775 if (private->uid.type != UA_BASE_DEVICE) 776 continue; 777 dasd_schedule_block_bh(device->block); 778 dasd_schedule_device_bh(device); 779 } 780 list_for_each_entry(device, &lcu->inactive_devices, alias_list) { 781 private = device->private; 782 if (private->uid.type != UA_BASE_DEVICE) 783 continue; 784 dasd_schedule_block_bh(device->block); 785 dasd_schedule_device_bh(device); 786 } 787 list_for_each_entry(pavgroup, &lcu->grouplist, group) { 788 list_for_each_entry(device, &pavgroup->baselist, alias_list) { 789 dasd_schedule_block_bh(device->block); 790 dasd_schedule_device_bh(device); 791 } 792 } 793} 794 795static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu) 796{ 797 struct alias_pav_group *pavgroup; 798 struct dasd_device *device, *temp; 799 struct dasd_eckd_private *private; 800 unsigned long flags; 801 LIST_HEAD(active); 802 803 /* 804 * Problem here ist that dasd_flush_device_queue may wait 805 * for termination of a request to complete. We can't keep 806 * the lcu lock during that time, so we must assume that 807 * the lists may have changed. 808 * Idea: first gather all active alias devices in a separate list, 809 * then flush the first element of this list unlocked, and afterwards 810 * check if it is still on the list before moving it to the 811 * active_devices list. 812 */ 813 814 spin_lock_irqsave(&lcu->lock, flags); 815 list_for_each_entry_safe(device, temp, &lcu->active_devices, 816 alias_list) { 817 private = device->private; 818 if (private->uid.type == UA_BASE_DEVICE) 819 continue; 820 list_move(&device->alias_list, &active); 821 } 822 823 list_for_each_entry(pavgroup, &lcu->grouplist, group) { 824 list_splice_init(&pavgroup->aliaslist, &active); 825 } 826 while (!list_empty(&active)) { 827 device = list_first_entry(&active, struct dasd_device, 828 alias_list); 829 spin_unlock_irqrestore(&lcu->lock, flags); 830 dasd_flush_device_queue(device); 831 spin_lock_irqsave(&lcu->lock, flags); 832 /* 833 * only move device around if it wasn't moved away while we 834 * were waiting for the flush 835 */ 836 if (device == list_first_entry(&active, 837 struct dasd_device, alias_list)) { 838 list_move(&device->alias_list, &lcu->active_devices); 839 private = device->private; 840 private->pavgroup = NULL; 841 } 842 } 843 spin_unlock_irqrestore(&lcu->lock, flags); 844} 845 846static void _stop_all_devices_on_lcu(struct alias_lcu *lcu) 847{ 848 struct alias_pav_group *pavgroup; 849 struct dasd_device *device; 850 851 list_for_each_entry(device, &lcu->active_devices, alias_list) { 852 spin_lock(get_ccwdev_lock(device->cdev)); 853 dasd_device_set_stop_bits(device, DASD_STOPPED_SU); 854 spin_unlock(get_ccwdev_lock(device->cdev)); 855 } 856 list_for_each_entry(device, &lcu->inactive_devices, alias_list) { 857 spin_lock(get_ccwdev_lock(device->cdev)); 858 dasd_device_set_stop_bits(device, DASD_STOPPED_SU); 859 spin_unlock(get_ccwdev_lock(device->cdev)); 860 } 861 list_for_each_entry(pavgroup, &lcu->grouplist, group) { 862 list_for_each_entry(device, &pavgroup->baselist, alias_list) { 863 spin_lock(get_ccwdev_lock(device->cdev)); 864 dasd_device_set_stop_bits(device, DASD_STOPPED_SU); 865 spin_unlock(get_ccwdev_lock(device->cdev)); 866 } 867 list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { 868 spin_lock(get_ccwdev_lock(device->cdev)); 869 dasd_device_set_stop_bits(device, DASD_STOPPED_SU); 870 spin_unlock(get_ccwdev_lock(device->cdev)); 871 } 872 } 873} 874 875static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu) 876{ 877 struct alias_pav_group *pavgroup; 878 struct dasd_device *device; 879 880 list_for_each_entry(device, &lcu->active_devices, alias_list) { 881 spin_lock(get_ccwdev_lock(device->cdev)); 882 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); 883 spin_unlock(get_ccwdev_lock(device->cdev)); 884 } 885 list_for_each_entry(device, &lcu->inactive_devices, alias_list) { 886 spin_lock(get_ccwdev_lock(device->cdev)); 887 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); 888 spin_unlock(get_ccwdev_lock(device->cdev)); 889 } 890 list_for_each_entry(pavgroup, &lcu->grouplist, group) { 891 list_for_each_entry(device, &pavgroup->baselist, alias_list) { 892 spin_lock(get_ccwdev_lock(device->cdev)); 893 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); 894 spin_unlock(get_ccwdev_lock(device->cdev)); 895 } 896 list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { 897 spin_lock(get_ccwdev_lock(device->cdev)); 898 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); 899 spin_unlock(get_ccwdev_lock(device->cdev)); 900 } 901 } 902} 903 904static void summary_unit_check_handling_work(struct work_struct *work) 905{ 906 struct alias_lcu *lcu; 907 struct summary_unit_check_work_data *suc_data; 908 unsigned long flags; 909 struct dasd_device *device; 910 911 suc_data = container_of(work, struct summary_unit_check_work_data, 912 worker); 913 lcu = container_of(suc_data, struct alias_lcu, suc_data); 914 device = suc_data->device; 915 916 /* 1. flush alias devices */ 917 flush_all_alias_devices_on_lcu(lcu); 918 919 /* 2. reset summary unit check */ 920 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); 921 dasd_device_remove_stop_bits(device, 922 (DASD_STOPPED_SU | DASD_STOPPED_PENDING)); 923 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); 924 reset_summary_unit_check(lcu, device, suc_data->reason); 925 926 spin_lock_irqsave(&lcu->lock, flags); 927 _unstop_all_devices_on_lcu(lcu); 928 _restart_all_base_devices_on_lcu(lcu); 929 /* 3. read new alias configuration */ 930 _schedule_lcu_update(lcu, device); 931 lcu->suc_data.device = NULL; 932 dasd_put_device(device); 933 spin_unlock_irqrestore(&lcu->lock, flags); 934} 935 936void dasd_alias_handle_summary_unit_check(struct work_struct *work) 937{ 938 struct dasd_device *device = container_of(work, struct dasd_device, 939 suc_work); 940 struct dasd_eckd_private *private = device->private; 941 struct alias_lcu *lcu; 942 unsigned long flags; 943 944 lcu = private->lcu; 945 if (!lcu) { 946 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 947 "device not ready to handle summary" 948 " unit check (no lcu structure)"); 949 goto out; 950 } 951 spin_lock_irqsave(&lcu->lock, flags); 952 /* If this device is about to be removed just return and wait for 953 * the next interrupt on a different device 954 */ 955 if (list_empty(&device->alias_list)) { 956 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 957 "device is in offline processing," 958 " don't do summary unit check handling"); 959 goto out_unlock; 960 } 961 if (lcu->suc_data.device) { 962 /* already scheduled or running */ 963 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 964 "previous instance of summary unit check worker" 965 " still pending"); 966 goto out_unlock; 967 } 968 _stop_all_devices_on_lcu(lcu); 969 /* prepare for lcu_update */ 970 lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING; 971 lcu->suc_data.reason = private->suc_reason; 972 lcu->suc_data.device = device; 973 dasd_get_device(device); 974 if (!schedule_work(&lcu->suc_data.worker)) 975 dasd_put_device(device); 976out_unlock: 977 spin_unlock_irqrestore(&lcu->lock, flags); 978out: 979 clear_bit(DASD_FLAG_SUC, &device->flags); 980 dasd_put_device(device); 981}; 982