1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * driver for channel subsystem 4 * 5 * Copyright IBM Corp. 2002, 2010 6 * 7 * Author(s): Arnd Bergmann (arndb@de.ibm.com) 8 * Cornelia Huck (cornelia.huck@de.ibm.com) 9 */ 10 11 #define KMSG_COMPONENT "cio" 12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 13 14 #include <linux/export.h> 15 #include <linux/init.h> 16 #include <linux/device.h> 17 #include <linux/slab.h> 18 #include <linux/errno.h> 19 #include <linux/list.h> 20 #include <linux/reboot.h> 21 #include <linux/proc_fs.h> 22 #include <linux/genalloc.h> 23 #include <linux/dma-mapping.h> 24 #include <asm/isc.h> 25 #include <asm/crw.h> 26 27 #include "css.h" 28 #include "cio.h" 29 #include "blacklist.h" 30 #include "cio_debug.h" 31 #include "ioasm.h" 32 #include "chsc.h" 33 #include "device.h" 34 #include "idset.h" 35 #include "chp.h" 36 37 int css_init_done = 0; 38 int max_ssid; 39 40 #define MAX_CSS_IDX 0 41 struct channel_subsystem *channel_subsystems[MAX_CSS_IDX + 1]; 42 static struct bus_type css_bus_type; 43 44 int 45 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data) 46 { 47 struct subchannel_id schid; 48 int ret; 49 50 init_subchannel_id(&schid); 51 do { 52 do { 53 ret = fn(schid, data); 54 if (ret) 55 break; 56 } while (schid.sch_no++ < __MAX_SUBCHANNEL); 57 schid.sch_no = 0; 58 } while (schid.ssid++ < max_ssid); 59 return ret; 60 } 61 62 struct cb_data { 63 void *data; 64 struct idset *set; 65 int (*fn_known_sch)(struct subchannel *, void *); 66 int (*fn_unknown_sch)(struct subchannel_id, void *); 67 }; 68 69 static int call_fn_known_sch(struct device *dev, void *data) 70 { 71 struct subchannel *sch = to_subchannel(dev); 72 struct cb_data *cb = data; 73 int rc = 0; 74 75 if (cb->set) 76 idset_sch_del(cb->set, sch->schid); 77 if (cb->fn_known_sch) 78 rc = cb->fn_known_sch(sch, cb->data); 79 return rc; 80 } 81 82 static int call_fn_unknown_sch(struct subchannel_id schid, void *data) 83 { 84 struct cb_data *cb = data; 85 int rc = 0; 86 87 if (idset_sch_contains(cb->set, schid)) 88 rc = cb->fn_unknown_sch(schid, cb->data); 89 return rc; 90 } 91 92 static int call_fn_all_sch(struct subchannel_id schid, void *data) 93 { 94 struct cb_data *cb = data; 95 struct subchannel *sch; 96 int rc = 0; 97 98 sch = get_subchannel_by_schid(schid); 99 if (sch) { 100 if (cb->fn_known_sch) 101 rc = cb->fn_known_sch(sch, cb->data); 102 put_device(&sch->dev); 103 } else { 104 if (cb->fn_unknown_sch) 105 rc = cb->fn_unknown_sch(schid, cb->data); 106 } 107 108 return rc; 109 } 110 111 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *), 112 int (*fn_unknown)(struct subchannel_id, 113 void *), void *data) 114 { 115 struct cb_data cb; 116 int rc; 117 118 cb.data = data; 119 cb.fn_known_sch = fn_known; 120 cb.fn_unknown_sch = fn_unknown; 121 122 if (fn_known && !fn_unknown) { 123 /* Skip idset allocation in case of known-only loop. */ 124 cb.set = NULL; 125 return bus_for_each_dev(&css_bus_type, NULL, &cb, 126 call_fn_known_sch); 127 } 128 129 cb.set = idset_sch_new(); 130 if (!cb.set) 131 /* fall back to brute force scanning in case of oom */ 132 return for_each_subchannel(call_fn_all_sch, &cb); 133 134 idset_fill(cb.set); 135 136 /* Process registered subchannels. */ 137 rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch); 138 if (rc) 139 goto out; 140 /* Process unregistered subchannels. */ 141 if (fn_unknown) 142 rc = for_each_subchannel(call_fn_unknown_sch, &cb); 143 out: 144 idset_free(cb.set); 145 146 return rc; 147 } 148 149 static void css_sch_todo(struct work_struct *work); 150 151 static int css_sch_create_locks(struct subchannel *sch) 152 { 153 sch->lock = kmalloc(sizeof(*sch->lock), GFP_KERNEL); 154 if (!sch->lock) 155 return -ENOMEM; 156 157 spin_lock_init(sch->lock); 158 mutex_init(&sch->reg_mutex); 159 160 return 0; 161 } 162 163 static void css_subchannel_release(struct device *dev) 164 { 165 struct subchannel *sch = to_subchannel(dev); 166 167 sch->config.intparm = 0; 168 cio_commit_config(sch); 169 kfree(sch->driver_override); 170 kfree(sch->lock); 171 kfree(sch); 172 } 173 174 static int css_validate_subchannel(struct subchannel_id schid, 175 struct schib *schib) 176 { 177 int err; 178 179 switch (schib->pmcw.st) { 180 case SUBCHANNEL_TYPE_IO: 181 case SUBCHANNEL_TYPE_MSG: 182 if (!css_sch_is_valid(schib)) 183 err = -ENODEV; 184 else if (is_blacklisted(schid.ssid, schib->pmcw.dev)) { 185 CIO_MSG_EVENT(6, "Blacklisted device detected " 186 "at devno %04X, subchannel set %x\n", 187 schib->pmcw.dev, schid.ssid); 188 err = -ENODEV; 189 } else 190 err = 0; 191 break; 192 default: 193 err = 0; 194 } 195 if (err) 196 goto out; 197 198 CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n", 199 schid.ssid, schid.sch_no, schib->pmcw.st); 200 out: 201 return err; 202 } 203 204 struct subchannel *css_alloc_subchannel(struct subchannel_id schid, 205 struct schib *schib) 206 { 207 struct subchannel *sch; 208 int ret; 209 210 ret = css_validate_subchannel(schid, schib); 211 if (ret < 0) 212 return ERR_PTR(ret); 213 214 sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA); 215 if (!sch) 216 return ERR_PTR(-ENOMEM); 217 218 sch->schid = schid; 219 sch->schib = *schib; 220 sch->st = schib->pmcw.st; 221 222 ret = css_sch_create_locks(sch); 223 if (ret) 224 goto err; 225 226 INIT_WORK(&sch->todo_work, css_sch_todo); 227 sch->dev.release = &css_subchannel_release; 228 sch->dev.dma_mask = &sch->dma_mask; 229 device_initialize(&sch->dev); 230 /* 231 * The physical addresses for some of the dma structures that can 232 * belong to a subchannel need to fit 31 bit width (e.g. ccw). 233 */ 234 ret = dma_set_coherent_mask(&sch->dev, DMA_BIT_MASK(31)); 235 if (ret) 236 goto err; 237 /* 238 * But we don't have such restrictions imposed on the stuff that 239 * is handled by the streaming API. 240 */ 241 ret = dma_set_mask(&sch->dev, DMA_BIT_MASK(64)); 242 if (ret) 243 goto err; 244 245 return sch; 246 247 err: 248 kfree(sch); 249 return ERR_PTR(ret); 250 } 251 252 static int css_sch_device_register(struct subchannel *sch) 253 { 254 int ret; 255 256 mutex_lock(&sch->reg_mutex); 257 dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid, 258 sch->schid.sch_no); 259 ret = device_add(&sch->dev); 260 mutex_unlock(&sch->reg_mutex); 261 return ret; 262 } 263 264 /** 265 * css_sch_device_unregister - unregister a subchannel 266 * @sch: subchannel to be unregistered 267 */ 268 void css_sch_device_unregister(struct subchannel *sch) 269 { 270 mutex_lock(&sch->reg_mutex); 271 if (device_is_registered(&sch->dev)) 272 device_unregister(&sch->dev); 273 mutex_unlock(&sch->reg_mutex); 274 } 275 EXPORT_SYMBOL_GPL(css_sch_device_unregister); 276 277 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw) 278 { 279 int i; 280 int mask; 281 282 memset(ssd, 0, sizeof(struct chsc_ssd_info)); 283 ssd->path_mask = pmcw->pim; 284 for (i = 0; i < 8; i++) { 285 mask = 0x80 >> i; 286 if (pmcw->pim & mask) { 287 chp_id_init(&ssd->chpid[i]); 288 ssd->chpid[i].id = pmcw->chpid[i]; 289 } 290 } 291 } 292 293 static void ssd_register_chpids(struct chsc_ssd_info *ssd) 294 { 295 int i; 296 int mask; 297 298 for (i = 0; i < 8; i++) { 299 mask = 0x80 >> i; 300 if (ssd->path_mask & mask) 301 chp_new(ssd->chpid[i]); 302 } 303 } 304 305 void css_update_ssd_info(struct subchannel *sch) 306 { 307 int ret; 308 309 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info); 310 if (ret) 311 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw); 312 313 ssd_register_chpids(&sch->ssd_info); 314 } 315 316 static ssize_t type_show(struct device *dev, struct device_attribute *attr, 317 char *buf) 318 { 319 struct subchannel *sch = to_subchannel(dev); 320 321 return sprintf(buf, "%01x\n", sch->st); 322 } 323 324 static DEVICE_ATTR_RO(type); 325 326 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, 327 char *buf) 328 { 329 struct subchannel *sch = to_subchannel(dev); 330 331 return sprintf(buf, "css:t%01X\n", sch->st); 332 } 333 334 static DEVICE_ATTR_RO(modalias); 335 336 static ssize_t driver_override_store(struct device *dev, 337 struct device_attribute *attr, 338 const char *buf, size_t count) 339 { 340 struct subchannel *sch = to_subchannel(dev); 341 char *driver_override, *old, *cp; 342 343 /* We need to keep extra room for a newline */ 344 if (count >= (PAGE_SIZE - 1)) 345 return -EINVAL; 346 347 driver_override = kstrndup(buf, count, GFP_KERNEL); 348 if (!driver_override) 349 return -ENOMEM; 350 351 cp = strchr(driver_override, '\n'); 352 if (cp) 353 *cp = '\0'; 354 355 device_lock(dev); 356 old = sch->driver_override; 357 if (strlen(driver_override)) { 358 sch->driver_override = driver_override; 359 } else { 360 kfree(driver_override); 361 sch->driver_override = NULL; 362 } 363 device_unlock(dev); 364 365 kfree(old); 366 367 return count; 368 } 369 370 static ssize_t driver_override_show(struct device *dev, 371 struct device_attribute *attr, char *buf) 372 { 373 struct subchannel *sch = to_subchannel(dev); 374 ssize_t len; 375 376 device_lock(dev); 377 len = snprintf(buf, PAGE_SIZE, "%s\n", sch->driver_override); 378 device_unlock(dev); 379 return len; 380 } 381 static DEVICE_ATTR_RW(driver_override); 382 383 static struct attribute *subch_attrs[] = { 384 &dev_attr_type.attr, 385 &dev_attr_modalias.attr, 386 &dev_attr_driver_override.attr, 387 NULL, 388 }; 389 390 static struct attribute_group subch_attr_group = { 391 .attrs = subch_attrs, 392 }; 393 394 static const struct attribute_group *default_subch_attr_groups[] = { 395 &subch_attr_group, 396 NULL, 397 }; 398 399 static ssize_t chpids_show(struct device *dev, 400 struct device_attribute *attr, 401 char *buf) 402 { 403 struct subchannel *sch = to_subchannel(dev); 404 struct chsc_ssd_info *ssd = &sch->ssd_info; 405 ssize_t ret = 0; 406 int mask; 407 int chp; 408 409 for (chp = 0; chp < 8; chp++) { 410 mask = 0x80 >> chp; 411 if (ssd->path_mask & mask) 412 ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id); 413 else 414 ret += sprintf(buf + ret, "00 "); 415 } 416 ret += sprintf(buf + ret, "\n"); 417 return ret; 418 } 419 static DEVICE_ATTR_RO(chpids); 420 421 static ssize_t pimpampom_show(struct device *dev, 422 struct device_attribute *attr, 423 char *buf) 424 { 425 struct subchannel *sch = to_subchannel(dev); 426 struct pmcw *pmcw = &sch->schib.pmcw; 427 428 return sprintf(buf, "%02x %02x %02x\n", 429 pmcw->pim, pmcw->pam, pmcw->pom); 430 } 431 static DEVICE_ATTR_RO(pimpampom); 432 433 static struct attribute *io_subchannel_type_attrs[] = { 434 &dev_attr_chpids.attr, 435 &dev_attr_pimpampom.attr, 436 NULL, 437 }; 438 ATTRIBUTE_GROUPS(io_subchannel_type); 439 440 static const struct device_type io_subchannel_type = { 441 .groups = io_subchannel_type_groups, 442 }; 443 444 int css_register_subchannel(struct subchannel *sch) 445 { 446 int ret; 447 448 /* Initialize the subchannel structure */ 449 sch->dev.parent = &channel_subsystems[0]->device; 450 sch->dev.bus = &css_bus_type; 451 sch->dev.groups = default_subch_attr_groups; 452 453 if (sch->st == SUBCHANNEL_TYPE_IO) 454 sch->dev.type = &io_subchannel_type; 455 456 /* 457 * We don't want to generate uevents for I/O subchannels that don't 458 * have a working ccw device behind them since they will be 459 * unregistered before they can be used anyway, so we delay the add 460 * uevent until after device recognition was successful. 461 * Note that we suppress the uevent for all subchannel types; 462 * the subchannel driver can decide itself when it wants to inform 463 * userspace of its existence. 464 */ 465 dev_set_uevent_suppress(&sch->dev, 1); 466 css_update_ssd_info(sch); 467 /* make it known to the system */ 468 ret = css_sch_device_register(sch); 469 if (ret) { 470 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n", 471 sch->schid.ssid, sch->schid.sch_no, ret); 472 return ret; 473 } 474 if (!sch->driver) { 475 /* 476 * No driver matched. Generate the uevent now so that 477 * a fitting driver module may be loaded based on the 478 * modalias. 479 */ 480 dev_set_uevent_suppress(&sch->dev, 0); 481 kobject_uevent(&sch->dev.kobj, KOBJ_ADD); 482 } 483 return ret; 484 } 485 486 static int css_probe_device(struct subchannel_id schid, struct schib *schib) 487 { 488 struct subchannel *sch; 489 int ret; 490 491 sch = css_alloc_subchannel(schid, schib); 492 if (IS_ERR(sch)) 493 return PTR_ERR(sch); 494 495 ret = css_register_subchannel(sch); 496 if (ret) 497 put_device(&sch->dev); 498 499 return ret; 500 } 501 502 static int 503 check_subchannel(struct device *dev, const void *data) 504 { 505 struct subchannel *sch; 506 struct subchannel_id *schid = (void *)data; 507 508 sch = to_subchannel(dev); 509 return schid_equal(&sch->schid, schid); 510 } 511 512 struct subchannel * 513 get_subchannel_by_schid(struct subchannel_id schid) 514 { 515 struct device *dev; 516 517 dev = bus_find_device(&css_bus_type, NULL, 518 &schid, check_subchannel); 519 520 return dev ? to_subchannel(dev) : NULL; 521 } 522 523 /** 524 * css_sch_is_valid() - check if a subchannel is valid 525 * @schib: subchannel information block for the subchannel 526 */ 527 int css_sch_is_valid(struct schib *schib) 528 { 529 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv) 530 return 0; 531 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w) 532 return 0; 533 return 1; 534 } 535 EXPORT_SYMBOL_GPL(css_sch_is_valid); 536 537 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow) 538 { 539 struct schib schib; 540 int ccode; 541 542 if (!slow) { 543 /* Will be done on the slow path. */ 544 return -EAGAIN; 545 } 546 /* 547 * The first subchannel that is not-operational (ccode==3) 548 * indicates that there aren't any more devices available. 549 * If stsch gets an exception, it means the current subchannel set 550 * is not valid. 551 */ 552 ccode = stsch(schid, &schib); 553 if (ccode) 554 return (ccode == 3) ? -ENXIO : ccode; 555 556 return css_probe_device(schid, &schib); 557 } 558 559 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow) 560 { 561 int ret = 0; 562 563 if (sch->driver) { 564 if (sch->driver->sch_event) 565 ret = sch->driver->sch_event(sch, slow); 566 else 567 dev_dbg(&sch->dev, 568 "Got subchannel machine check but " 569 "no sch_event handler provided.\n"); 570 } 571 if (ret != 0 && ret != -EAGAIN) { 572 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n", 573 sch->schid.ssid, sch->schid.sch_no, ret); 574 } 575 return ret; 576 } 577 578 static void css_evaluate_subchannel(struct subchannel_id schid, int slow) 579 { 580 struct subchannel *sch; 581 int ret; 582 583 sch = get_subchannel_by_schid(schid); 584 if (sch) { 585 ret = css_evaluate_known_subchannel(sch, slow); 586 put_device(&sch->dev); 587 } else 588 ret = css_evaluate_new_subchannel(schid, slow); 589 if (ret == -EAGAIN) 590 css_schedule_eval(schid); 591 } 592 593 /** 594 * css_sched_sch_todo - schedule a subchannel operation 595 * @sch: subchannel 596 * @todo: todo 597 * 598 * Schedule the operation identified by @todo to be performed on the slow path 599 * workqueue. Do nothing if another operation with higher priority is already 600 * scheduled. Needs to be called with subchannel lock held. 601 */ 602 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo) 603 { 604 CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n", 605 sch->schid.ssid, sch->schid.sch_no, todo); 606 if (sch->todo >= todo) 607 return; 608 /* Get workqueue ref. */ 609 if (!get_device(&sch->dev)) 610 return; 611 sch->todo = todo; 612 if (!queue_work(cio_work_q, &sch->todo_work)) { 613 /* Already queued, release workqueue ref. */ 614 put_device(&sch->dev); 615 } 616 } 617 EXPORT_SYMBOL_GPL(css_sched_sch_todo); 618 619 static void css_sch_todo(struct work_struct *work) 620 { 621 struct subchannel *sch; 622 enum sch_todo todo; 623 int ret; 624 625 sch = container_of(work, struct subchannel, todo_work); 626 /* Find out todo. */ 627 spin_lock_irq(sch->lock); 628 todo = sch->todo; 629 CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid, 630 sch->schid.sch_no, todo); 631 sch->todo = SCH_TODO_NOTHING; 632 spin_unlock_irq(sch->lock); 633 /* Perform todo. */ 634 switch (todo) { 635 case SCH_TODO_NOTHING: 636 break; 637 case SCH_TODO_EVAL: 638 ret = css_evaluate_known_subchannel(sch, 1); 639 if (ret == -EAGAIN) { 640 spin_lock_irq(sch->lock); 641 css_sched_sch_todo(sch, todo); 642 spin_unlock_irq(sch->lock); 643 } 644 break; 645 case SCH_TODO_UNREG: 646 css_sch_device_unregister(sch); 647 break; 648 } 649 /* Release workqueue ref. */ 650 put_device(&sch->dev); 651 } 652 653 static struct idset *slow_subchannel_set; 654 static DEFINE_SPINLOCK(slow_subchannel_lock); 655 static DECLARE_WAIT_QUEUE_HEAD(css_eval_wq); 656 static atomic_t css_eval_scheduled; 657 658 static int __init slow_subchannel_init(void) 659 { 660 atomic_set(&css_eval_scheduled, 0); 661 slow_subchannel_set = idset_sch_new(); 662 if (!slow_subchannel_set) { 663 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n"); 664 return -ENOMEM; 665 } 666 return 0; 667 } 668 669 static int slow_eval_known_fn(struct subchannel *sch, void *data) 670 { 671 int eval; 672 int rc; 673 674 spin_lock_irq(&slow_subchannel_lock); 675 eval = idset_sch_contains(slow_subchannel_set, sch->schid); 676 idset_sch_del(slow_subchannel_set, sch->schid); 677 spin_unlock_irq(&slow_subchannel_lock); 678 if (eval) { 679 rc = css_evaluate_known_subchannel(sch, 1); 680 if (rc == -EAGAIN) 681 css_schedule_eval(sch->schid); 682 /* 683 * The loop might take long time for platforms with lots of 684 * known devices. Allow scheduling here. 685 */ 686 cond_resched(); 687 } 688 return 0; 689 } 690 691 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data) 692 { 693 int eval; 694 int rc = 0; 695 696 spin_lock_irq(&slow_subchannel_lock); 697 eval = idset_sch_contains(slow_subchannel_set, schid); 698 idset_sch_del(slow_subchannel_set, schid); 699 spin_unlock_irq(&slow_subchannel_lock); 700 if (eval) { 701 rc = css_evaluate_new_subchannel(schid, 1); 702 switch (rc) { 703 case -EAGAIN: 704 css_schedule_eval(schid); 705 rc = 0; 706 break; 707 case -ENXIO: 708 case -ENOMEM: 709 case -EIO: 710 /* These should abort looping */ 711 spin_lock_irq(&slow_subchannel_lock); 712 idset_sch_del_subseq(slow_subchannel_set, schid); 713 spin_unlock_irq(&slow_subchannel_lock); 714 break; 715 default: 716 rc = 0; 717 } 718 /* Allow scheduling here since the containing loop might 719 * take a while. */ 720 cond_resched(); 721 } 722 return rc; 723 } 724 725 static void css_slow_path_func(struct work_struct *unused) 726 { 727 unsigned long flags; 728 729 CIO_TRACE_EVENT(4, "slowpath"); 730 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn, 731 NULL); 732 spin_lock_irqsave(&slow_subchannel_lock, flags); 733 if (idset_is_empty(slow_subchannel_set)) { 734 atomic_set(&css_eval_scheduled, 0); 735 wake_up(&css_eval_wq); 736 } 737 spin_unlock_irqrestore(&slow_subchannel_lock, flags); 738 } 739 740 static DECLARE_DELAYED_WORK(slow_path_work, css_slow_path_func); 741 struct workqueue_struct *cio_work_q; 742 743 void css_schedule_eval(struct subchannel_id schid) 744 { 745 unsigned long flags; 746 747 spin_lock_irqsave(&slow_subchannel_lock, flags); 748 idset_sch_add(slow_subchannel_set, schid); 749 atomic_set(&css_eval_scheduled, 1); 750 queue_delayed_work(cio_work_q, &slow_path_work, 0); 751 spin_unlock_irqrestore(&slow_subchannel_lock, flags); 752 } 753 754 void css_schedule_eval_all(void) 755 { 756 unsigned long flags; 757 758 spin_lock_irqsave(&slow_subchannel_lock, flags); 759 idset_fill(slow_subchannel_set); 760 atomic_set(&css_eval_scheduled, 1); 761 queue_delayed_work(cio_work_q, &slow_path_work, 0); 762 spin_unlock_irqrestore(&slow_subchannel_lock, flags); 763 } 764 765 static int __unset_registered(struct device *dev, void *data) 766 { 767 struct idset *set = data; 768 struct subchannel *sch = to_subchannel(dev); 769 770 idset_sch_del(set, sch->schid); 771 return 0; 772 } 773 774 void css_schedule_eval_all_unreg(unsigned long delay) 775 { 776 unsigned long flags; 777 struct idset *unreg_set; 778 779 /* Find unregistered subchannels. */ 780 unreg_set = idset_sch_new(); 781 if (!unreg_set) { 782 /* Fallback. */ 783 css_schedule_eval_all(); 784 return; 785 } 786 idset_fill(unreg_set); 787 bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered); 788 /* Apply to slow_subchannel_set. */ 789 spin_lock_irqsave(&slow_subchannel_lock, flags); 790 idset_add_set(slow_subchannel_set, unreg_set); 791 atomic_set(&css_eval_scheduled, 1); 792 queue_delayed_work(cio_work_q, &slow_path_work, delay); 793 spin_unlock_irqrestore(&slow_subchannel_lock, flags); 794 idset_free(unreg_set); 795 } 796 797 void css_wait_for_slow_path(void) 798 { 799 flush_workqueue(cio_work_q); 800 } 801 802 /* Schedule reprobing of all unregistered subchannels. */ 803 void css_schedule_reprobe(void) 804 { 805 /* Schedule with a delay to allow merging of subsequent calls. */ 806 css_schedule_eval_all_unreg(1 * HZ); 807 } 808 EXPORT_SYMBOL_GPL(css_schedule_reprobe); 809 810 /* 811 * Called from the machine check handler for subchannel report words. 812 */ 813 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow) 814 { 815 struct subchannel_id mchk_schid; 816 struct subchannel *sch; 817 818 if (overflow) { 819 css_schedule_eval_all(); 820 return; 821 } 822 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, " 823 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", 824 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc, 825 crw0->erc, crw0->rsid); 826 if (crw1) 827 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, " 828 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", 829 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc, 830 crw1->anc, crw1->erc, crw1->rsid); 831 init_subchannel_id(&mchk_schid); 832 mchk_schid.sch_no = crw0->rsid; 833 if (crw1) 834 mchk_schid.ssid = (crw1->rsid >> 4) & 3; 835 836 if (crw0->erc == CRW_ERC_PMOD) { 837 sch = get_subchannel_by_schid(mchk_schid); 838 if (sch) { 839 css_update_ssd_info(sch); 840 put_device(&sch->dev); 841 } 842 } 843 /* 844 * Since we are always presented with IPI in the CRW, we have to 845 * use stsch() to find out if the subchannel in question has come 846 * or gone. 847 */ 848 css_evaluate_subchannel(mchk_schid, 0); 849 } 850 851 static void __init 852 css_generate_pgid(struct channel_subsystem *css, u32 tod_high) 853 { 854 struct cpuid cpu_id; 855 856 if (css_general_characteristics.mcss) { 857 css->global_pgid.pgid_high.ext_cssid.version = 0x80; 858 css->global_pgid.pgid_high.ext_cssid.cssid = 859 css->id_valid ? css->cssid : 0; 860 } else { 861 css->global_pgid.pgid_high.cpu_addr = stap(); 862 } 863 get_cpu_id(&cpu_id); 864 css->global_pgid.cpu_id = cpu_id.ident; 865 css->global_pgid.cpu_model = cpu_id.machine; 866 css->global_pgid.tod_high = tod_high; 867 } 868 869 static void channel_subsystem_release(struct device *dev) 870 { 871 struct channel_subsystem *css = to_css(dev); 872 873 mutex_destroy(&css->mutex); 874 kfree(css); 875 } 876 877 static ssize_t real_cssid_show(struct device *dev, struct device_attribute *a, 878 char *buf) 879 { 880 struct channel_subsystem *css = to_css(dev); 881 882 if (!css->id_valid) 883 return -EINVAL; 884 885 return sprintf(buf, "%x\n", css->cssid); 886 } 887 static DEVICE_ATTR_RO(real_cssid); 888 889 static ssize_t cm_enable_show(struct device *dev, struct device_attribute *a, 890 char *buf) 891 { 892 struct channel_subsystem *css = to_css(dev); 893 int ret; 894 895 mutex_lock(&css->mutex); 896 ret = sprintf(buf, "%x\n", css->cm_enabled); 897 mutex_unlock(&css->mutex); 898 return ret; 899 } 900 901 static ssize_t cm_enable_store(struct device *dev, struct device_attribute *a, 902 const char *buf, size_t count) 903 { 904 struct channel_subsystem *css = to_css(dev); 905 unsigned long val; 906 int ret; 907 908 ret = kstrtoul(buf, 16, &val); 909 if (ret) 910 return ret; 911 mutex_lock(&css->mutex); 912 switch (val) { 913 case 0: 914 ret = css->cm_enabled ? chsc_secm(css, 0) : 0; 915 break; 916 case 1: 917 ret = css->cm_enabled ? 0 : chsc_secm(css, 1); 918 break; 919 default: 920 ret = -EINVAL; 921 } 922 mutex_unlock(&css->mutex); 923 return ret < 0 ? ret : count; 924 } 925 static DEVICE_ATTR_RW(cm_enable); 926 927 static umode_t cm_enable_mode(struct kobject *kobj, struct attribute *attr, 928 int index) 929 { 930 return css_chsc_characteristics.secm ? attr->mode : 0; 931 } 932 933 static struct attribute *cssdev_attrs[] = { 934 &dev_attr_real_cssid.attr, 935 NULL, 936 }; 937 938 static struct attribute_group cssdev_attr_group = { 939 .attrs = cssdev_attrs, 940 }; 941 942 static struct attribute *cssdev_cm_attrs[] = { 943 &dev_attr_cm_enable.attr, 944 NULL, 945 }; 946 947 static struct attribute_group cssdev_cm_attr_group = { 948 .attrs = cssdev_cm_attrs, 949 .is_visible = cm_enable_mode, 950 }; 951 952 static const struct attribute_group *cssdev_attr_groups[] = { 953 &cssdev_attr_group, 954 &cssdev_cm_attr_group, 955 NULL, 956 }; 957 958 static int __init setup_css(int nr) 959 { 960 struct channel_subsystem *css; 961 int ret; 962 963 css = kzalloc(sizeof(*css), GFP_KERNEL); 964 if (!css) 965 return -ENOMEM; 966 967 channel_subsystems[nr] = css; 968 dev_set_name(&css->device, "css%x", nr); 969 css->device.groups = cssdev_attr_groups; 970 css->device.release = channel_subsystem_release; 971 /* 972 * We currently allocate notifier bits with this (using 973 * css->device as the device argument with the DMA API) 974 * and are fine with 64 bit addresses. 975 */ 976 ret = dma_coerce_mask_and_coherent(&css->device, DMA_BIT_MASK(64)); 977 if (ret) { 978 kfree(css); 979 goto out_err; 980 } 981 982 mutex_init(&css->mutex); 983 ret = chsc_get_cssid_iid(nr, &css->cssid, &css->iid); 984 if (!ret) { 985 css->id_valid = true; 986 pr_info("Partition identifier %01x.%01x\n", css->cssid, 987 css->iid); 988 } 989 css_generate_pgid(css, (u32) (get_tod_clock() >> 32)); 990 991 ret = device_register(&css->device); 992 if (ret) { 993 put_device(&css->device); 994 goto out_err; 995 } 996 997 css->pseudo_subchannel = kzalloc(sizeof(*css->pseudo_subchannel), 998 GFP_KERNEL); 999 if (!css->pseudo_subchannel) { 1000 device_unregister(&css->device); 1001 ret = -ENOMEM; 1002 goto out_err; 1003 } 1004 1005 css->pseudo_subchannel->dev.parent = &css->device; 1006 css->pseudo_subchannel->dev.release = css_subchannel_release; 1007 mutex_init(&css->pseudo_subchannel->reg_mutex); 1008 ret = css_sch_create_locks(css->pseudo_subchannel); 1009 if (ret) { 1010 kfree(css->pseudo_subchannel); 1011 device_unregister(&css->device); 1012 goto out_err; 1013 } 1014 1015 dev_set_name(&css->pseudo_subchannel->dev, "defunct"); 1016 ret = device_register(&css->pseudo_subchannel->dev); 1017 if (ret) { 1018 put_device(&css->pseudo_subchannel->dev); 1019 device_unregister(&css->device); 1020 goto out_err; 1021 } 1022 1023 return ret; 1024 out_err: 1025 channel_subsystems[nr] = NULL; 1026 return ret; 1027 } 1028 1029 static int css_reboot_event(struct notifier_block *this, 1030 unsigned long event, 1031 void *ptr) 1032 { 1033 struct channel_subsystem *css; 1034 int ret; 1035 1036 ret = NOTIFY_DONE; 1037 for_each_css(css) { 1038 mutex_lock(&css->mutex); 1039 if (css->cm_enabled) 1040 if (chsc_secm(css, 0)) 1041 ret = NOTIFY_BAD; 1042 mutex_unlock(&css->mutex); 1043 } 1044 1045 return ret; 1046 } 1047 1048 static struct notifier_block css_reboot_notifier = { 1049 .notifier_call = css_reboot_event, 1050 }; 1051 1052 #define CIO_DMA_GFP (GFP_KERNEL | __GFP_ZERO) 1053 static struct gen_pool *cio_dma_pool; 1054 1055 /* Currently cio supports only a single css */ 1056 struct device *cio_get_dma_css_dev(void) 1057 { 1058 return &channel_subsystems[0]->device; 1059 } 1060 1061 struct gen_pool *cio_gp_dma_create(struct device *dma_dev, int nr_pages) 1062 { 1063 struct gen_pool *gp_dma; 1064 void *cpu_addr; 1065 dma_addr_t dma_addr; 1066 int i; 1067 1068 gp_dma = gen_pool_create(3, -1); 1069 if (!gp_dma) 1070 return NULL; 1071 for (i = 0; i < nr_pages; ++i) { 1072 cpu_addr = dma_alloc_coherent(dma_dev, PAGE_SIZE, &dma_addr, 1073 CIO_DMA_GFP); 1074 if (!cpu_addr) 1075 return gp_dma; 1076 gen_pool_add_virt(gp_dma, (unsigned long) cpu_addr, 1077 dma_addr, PAGE_SIZE, -1); 1078 } 1079 return gp_dma; 1080 } 1081 1082 static void __gp_dma_free_dma(struct gen_pool *pool, 1083 struct gen_pool_chunk *chunk, void *data) 1084 { 1085 size_t chunk_size = chunk->end_addr - chunk->start_addr + 1; 1086 1087 dma_free_coherent((struct device *) data, chunk_size, 1088 (void *) chunk->start_addr, 1089 (dma_addr_t) chunk->phys_addr); 1090 } 1091 1092 void cio_gp_dma_destroy(struct gen_pool *gp_dma, struct device *dma_dev) 1093 { 1094 if (!gp_dma) 1095 return; 1096 /* this is quite ugly but no better idea */ 1097 gen_pool_for_each_chunk(gp_dma, __gp_dma_free_dma, dma_dev); 1098 gen_pool_destroy(gp_dma); 1099 } 1100 1101 static int cio_dma_pool_init(void) 1102 { 1103 /* No need to free up the resources: compiled in */ 1104 cio_dma_pool = cio_gp_dma_create(cio_get_dma_css_dev(), 1); 1105 if (!cio_dma_pool) 1106 return -ENOMEM; 1107 return 0; 1108 } 1109 1110 void *cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev, 1111 size_t size) 1112 { 1113 dma_addr_t dma_addr; 1114 unsigned long addr; 1115 size_t chunk_size; 1116 1117 if (!gp_dma) 1118 return NULL; 1119 addr = gen_pool_alloc(gp_dma, size); 1120 while (!addr) { 1121 chunk_size = round_up(size, PAGE_SIZE); 1122 addr = (unsigned long) dma_alloc_coherent(dma_dev, 1123 chunk_size, &dma_addr, CIO_DMA_GFP); 1124 if (!addr) 1125 return NULL; 1126 gen_pool_add_virt(gp_dma, addr, dma_addr, chunk_size, -1); 1127 addr = gen_pool_alloc(gp_dma, size); 1128 } 1129 return (void *) addr; 1130 } 1131 1132 void cio_gp_dma_free(struct gen_pool *gp_dma, void *cpu_addr, size_t size) 1133 { 1134 if (!cpu_addr) 1135 return; 1136 memset(cpu_addr, 0, size); 1137 gen_pool_free(gp_dma, (unsigned long) cpu_addr, size); 1138 } 1139 1140 /* 1141 * Allocate dma memory from the css global pool. Intended for memory not 1142 * specific to any single device within the css. The allocated memory 1143 * is not guaranteed to be 31-bit addressable. 1144 * 1145 * Caution: Not suitable for early stuff like console. 1146 */ 1147 void *cio_dma_zalloc(size_t size) 1148 { 1149 return cio_gp_dma_zalloc(cio_dma_pool, cio_get_dma_css_dev(), size); 1150 } 1151 1152 void cio_dma_free(void *cpu_addr, size_t size) 1153 { 1154 cio_gp_dma_free(cio_dma_pool, cpu_addr, size); 1155 } 1156 1157 /* 1158 * Now that the driver core is running, we can setup our channel subsystem. 1159 * The struct subchannel's are created during probing. 1160 */ 1161 static int __init css_bus_init(void) 1162 { 1163 int ret, i; 1164 1165 ret = chsc_init(); 1166 if (ret) 1167 return ret; 1168 1169 chsc_determine_css_characteristics(); 1170 /* Try to enable MSS. */ 1171 ret = chsc_enable_facility(CHSC_SDA_OC_MSS); 1172 if (ret) 1173 max_ssid = 0; 1174 else /* Success. */ 1175 max_ssid = __MAX_SSID; 1176 1177 ret = slow_subchannel_init(); 1178 if (ret) 1179 goto out; 1180 1181 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw); 1182 if (ret) 1183 goto out; 1184 1185 if ((ret = bus_register(&css_bus_type))) 1186 goto out; 1187 1188 /* Setup css structure. */ 1189 for (i = 0; i <= MAX_CSS_IDX; i++) { 1190 ret = setup_css(i); 1191 if (ret) 1192 goto out_unregister; 1193 } 1194 ret = register_reboot_notifier(&css_reboot_notifier); 1195 if (ret) 1196 goto out_unregister; 1197 ret = cio_dma_pool_init(); 1198 if (ret) 1199 goto out_unregister_rn; 1200 airq_init(); 1201 css_init_done = 1; 1202 1203 /* Enable default isc for I/O subchannels. */ 1204 isc_register(IO_SCH_ISC); 1205 1206 return 0; 1207 out_unregister_rn: 1208 unregister_reboot_notifier(&css_reboot_notifier); 1209 out_unregister: 1210 while (i-- > 0) { 1211 struct channel_subsystem *css = channel_subsystems[i]; 1212 device_unregister(&css->pseudo_subchannel->dev); 1213 device_unregister(&css->device); 1214 } 1215 bus_unregister(&css_bus_type); 1216 out: 1217 crw_unregister_handler(CRW_RSC_SCH); 1218 idset_free(slow_subchannel_set); 1219 chsc_init_cleanup(); 1220 pr_alert("The CSS device driver initialization failed with " 1221 "errno=%d\n", ret); 1222 return ret; 1223 } 1224 1225 static void __init css_bus_cleanup(void) 1226 { 1227 struct channel_subsystem *css; 1228 1229 for_each_css(css) { 1230 device_unregister(&css->pseudo_subchannel->dev); 1231 device_unregister(&css->device); 1232 } 1233 bus_unregister(&css_bus_type); 1234 crw_unregister_handler(CRW_RSC_SCH); 1235 idset_free(slow_subchannel_set); 1236 chsc_init_cleanup(); 1237 isc_unregister(IO_SCH_ISC); 1238 } 1239 1240 static int __init channel_subsystem_init(void) 1241 { 1242 int ret; 1243 1244 ret = css_bus_init(); 1245 if (ret) 1246 return ret; 1247 cio_work_q = create_singlethread_workqueue("cio"); 1248 if (!cio_work_q) { 1249 ret = -ENOMEM; 1250 goto out_bus; 1251 } 1252 ret = io_subchannel_init(); 1253 if (ret) 1254 goto out_wq; 1255 1256 /* Register subchannels which are already in use. */ 1257 cio_register_early_subchannels(); 1258 /* Start initial subchannel evaluation. */ 1259 css_schedule_eval_all(); 1260 1261 return ret; 1262 out_wq: 1263 destroy_workqueue(cio_work_q); 1264 out_bus: 1265 css_bus_cleanup(); 1266 return ret; 1267 } 1268 subsys_initcall(channel_subsystem_init); 1269 1270 static int css_settle(struct device_driver *drv, void *unused) 1271 { 1272 struct css_driver *cssdrv = to_cssdriver(drv); 1273 1274 if (cssdrv->settle) 1275 return cssdrv->settle(); 1276 return 0; 1277 } 1278 1279 int css_complete_work(void) 1280 { 1281 int ret; 1282 1283 /* Wait for the evaluation of subchannels to finish. */ 1284 ret = wait_event_interruptible(css_eval_wq, 1285 atomic_read(&css_eval_scheduled) == 0); 1286 if (ret) 1287 return -EINTR; 1288 flush_workqueue(cio_work_q); 1289 /* Wait for the subchannel type specific initialization to finish */ 1290 return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle); 1291 } 1292 1293 1294 /* 1295 * Wait for the initialization of devices to finish, to make sure we are 1296 * done with our setup if the search for the root device starts. 1297 */ 1298 static int __init channel_subsystem_init_sync(void) 1299 { 1300 css_complete_work(); 1301 return 0; 1302 } 1303 subsys_initcall_sync(channel_subsystem_init_sync); 1304 1305 #ifdef CONFIG_PROC_FS 1306 static ssize_t cio_settle_write(struct file *file, const char __user *buf, 1307 size_t count, loff_t *ppos) 1308 { 1309 int ret; 1310 1311 /* Handle pending CRW's. */ 1312 crw_wait_for_channel_report(); 1313 ret = css_complete_work(); 1314 1315 return ret ? ret : count; 1316 } 1317 1318 static const struct proc_ops cio_settle_proc_ops = { 1319 .proc_open = nonseekable_open, 1320 .proc_write = cio_settle_write, 1321 .proc_lseek = no_llseek, 1322 }; 1323 1324 static int __init cio_settle_init(void) 1325 { 1326 struct proc_dir_entry *entry; 1327 1328 entry = proc_create("cio_settle", S_IWUSR, NULL, &cio_settle_proc_ops); 1329 if (!entry) 1330 return -ENOMEM; 1331 return 0; 1332 } 1333 device_initcall(cio_settle_init); 1334 #endif /*CONFIG_PROC_FS*/ 1335 1336 int sch_is_pseudo_sch(struct subchannel *sch) 1337 { 1338 if (!sch->dev.parent) 1339 return 0; 1340 return sch == to_css(sch->dev.parent)->pseudo_subchannel; 1341 } 1342 1343 static int css_bus_match(struct device *dev, struct device_driver *drv) 1344 { 1345 struct subchannel *sch = to_subchannel(dev); 1346 struct css_driver *driver = to_cssdriver(drv); 1347 struct css_device_id *id; 1348 1349 /* When driver_override is set, only bind to the matching driver */ 1350 if (sch->driver_override && strcmp(sch->driver_override, drv->name)) 1351 return 0; 1352 1353 for (id = driver->subchannel_type; id->match_flags; id++) { 1354 if (sch->st == id->type) 1355 return 1; 1356 } 1357 1358 return 0; 1359 } 1360 1361 static int css_probe(struct device *dev) 1362 { 1363 struct subchannel *sch; 1364 int ret; 1365 1366 sch = to_subchannel(dev); 1367 sch->driver = to_cssdriver(dev->driver); 1368 ret = sch->driver->probe ? sch->driver->probe(sch) : 0; 1369 if (ret) 1370 sch->driver = NULL; 1371 return ret; 1372 } 1373 1374 static int css_remove(struct device *dev) 1375 { 1376 struct subchannel *sch; 1377 int ret; 1378 1379 sch = to_subchannel(dev); 1380 ret = sch->driver->remove ? sch->driver->remove(sch) : 0; 1381 sch->driver = NULL; 1382 return ret; 1383 } 1384 1385 static void css_shutdown(struct device *dev) 1386 { 1387 struct subchannel *sch; 1388 1389 sch = to_subchannel(dev); 1390 if (sch->driver && sch->driver->shutdown) 1391 sch->driver->shutdown(sch); 1392 } 1393 1394 static int css_uevent(struct device *dev, struct kobj_uevent_env *env) 1395 { 1396 struct subchannel *sch = to_subchannel(dev); 1397 int ret; 1398 1399 ret = add_uevent_var(env, "ST=%01X", sch->st); 1400 if (ret) 1401 return ret; 1402 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st); 1403 return ret; 1404 } 1405 1406 static struct bus_type css_bus_type = { 1407 .name = "css", 1408 .match = css_bus_match, 1409 .probe = css_probe, 1410 .remove = css_remove, 1411 .shutdown = css_shutdown, 1412 .uevent = css_uevent, 1413 }; 1414 1415 /** 1416 * css_driver_register - register a css driver 1417 * @cdrv: css driver to register 1418 * 1419 * This is mainly a wrapper around driver_register that sets name 1420 * and bus_type in the embedded struct device_driver correctly. 1421 */ 1422 int css_driver_register(struct css_driver *cdrv) 1423 { 1424 cdrv->drv.bus = &css_bus_type; 1425 return driver_register(&cdrv->drv); 1426 } 1427 EXPORT_SYMBOL_GPL(css_driver_register); 1428 1429 /** 1430 * css_driver_unregister - unregister a css driver 1431 * @cdrv: css driver to unregister 1432 * 1433 * This is a wrapper around driver_unregister. 1434 */ 1435 void css_driver_unregister(struct css_driver *cdrv) 1436 { 1437 driver_unregister(&cdrv->drv); 1438 } 1439 EXPORT_SYMBOL_GPL(css_driver_unregister); 1440