1 /* 2 * drivers/s390/cio/chp.c 3 * 4 * Copyright IBM Corp. 1999,2010 5 * Author(s): Cornelia Huck (cornelia.huck@de.ibm.com) 6 * Arnd Bergmann (arndb@de.ibm.com) 7 * Peter Oberparleiter <peter.oberparleiter@de.ibm.com> 8 */ 9 10 #include <linux/bug.h> 11 #include <linux/workqueue.h> 12 #include <linux/spinlock.h> 13 #include <linux/init.h> 14 #include <linux/jiffies.h> 15 #include <linux/wait.h> 16 #include <linux/mutex.h> 17 #include <linux/errno.h> 18 #include <linux/slab.h> 19 #include <asm/chpid.h> 20 #include <asm/sclp.h> 21 #include <asm/crw.h> 22 23 #include "cio.h" 24 #include "css.h" 25 #include "ioasm.h" 26 #include "cio_debug.h" 27 #include "chp.h" 28 29 #define to_channelpath(device) container_of(device, struct channel_path, dev) 30 #define CHP_INFO_UPDATE_INTERVAL 1*HZ 31 32 enum cfg_task_t { 33 cfg_none, 34 cfg_configure, 35 cfg_deconfigure 36 }; 37 38 /* Map for pending configure tasks. */ 39 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1]; 40 static DEFINE_MUTEX(cfg_lock); 41 static int cfg_busy; 42 43 /* Map for channel-path status. */ 44 static struct sclp_chp_info chp_info; 45 static DEFINE_MUTEX(info_lock); 46 47 /* Time after which channel-path status may be outdated. */ 48 static unsigned long chp_info_expires; 49 50 /* Workqueue to perform pending configure tasks. */ 51 static struct workqueue_struct *chp_wq; 52 static struct work_struct cfg_work; 53 54 /* Wait queue for configure completion events. */ 55 static wait_queue_head_t cfg_wait_queue; 56 57 /* Set vary state for given chpid. */ 58 static void set_chp_logically_online(struct chp_id chpid, int onoff) 59 { 60 chpid_to_chp(chpid)->state = onoff; 61 } 62 63 /* On success return 0 if channel-path is varied offline, 1 if it is varied 64 * online. Return -ENODEV if channel-path is not registered. */ 65 int chp_get_status(struct chp_id chpid) 66 { 67 return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV); 68 } 69 70 /** 71 * chp_get_sch_opm - return opm for subchannel 72 * @sch: subchannel 73 * 74 * Calculate and return the operational path mask (opm) based on the chpids 75 * used by the subchannel and the status of the associated channel-paths. 76 */ 77 u8 chp_get_sch_opm(struct subchannel *sch) 78 { 79 struct chp_id chpid; 80 int opm; 81 int i; 82 83 opm = 0; 84 chp_id_init(&chpid); 85 for (i = 0; i < 8; i++) { 86 opm <<= 1; 87 chpid.id = sch->schib.pmcw.chpid[i]; 88 if (chp_get_status(chpid) != 0) 89 opm |= 1; 90 } 91 return opm; 92 } 93 EXPORT_SYMBOL_GPL(chp_get_sch_opm); 94 95 /** 96 * chp_is_registered - check if a channel-path is registered 97 * @chpid: channel-path ID 98 * 99 * Return non-zero if a channel-path with the given chpid is registered, 100 * zero otherwise. 101 */ 102 int chp_is_registered(struct chp_id chpid) 103 { 104 return chpid_to_chp(chpid) != NULL; 105 } 106 107 /* 108 * Function: s390_vary_chpid 109 * Varies the specified chpid online or offline 110 */ 111 static int s390_vary_chpid(struct chp_id chpid, int on) 112 { 113 char dbf_text[15]; 114 int status; 115 116 sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid, 117 chpid.id); 118 CIO_TRACE_EVENT(2, dbf_text); 119 120 status = chp_get_status(chpid); 121 if (!on && !status) 122 return 0; 123 124 set_chp_logically_online(chpid, on); 125 chsc_chp_vary(chpid, on); 126 return 0; 127 } 128 129 /* 130 * Channel measurement related functions 131 */ 132 static ssize_t chp_measurement_chars_read(struct file *filp, 133 struct kobject *kobj, 134 struct bin_attribute *bin_attr, 135 char *buf, loff_t off, size_t count) 136 { 137 struct channel_path *chp; 138 struct device *device; 139 140 device = container_of(kobj, struct device, kobj); 141 chp = to_channelpath(device); 142 if (!chp->cmg_chars) 143 return 0; 144 145 return memory_read_from_buffer(buf, count, &off, 146 chp->cmg_chars, sizeof(struct cmg_chars)); 147 } 148 149 static struct bin_attribute chp_measurement_chars_attr = { 150 .attr = { 151 .name = "measurement_chars", 152 .mode = S_IRUSR, 153 }, 154 .size = sizeof(struct cmg_chars), 155 .read = chp_measurement_chars_read, 156 }; 157 158 static void chp_measurement_copy_block(struct cmg_entry *buf, 159 struct channel_subsystem *css, 160 struct chp_id chpid) 161 { 162 void *area; 163 struct cmg_entry *entry, reference_buf; 164 int idx; 165 166 if (chpid.id < 128) { 167 area = css->cub_addr1; 168 idx = chpid.id; 169 } else { 170 area = css->cub_addr2; 171 idx = chpid.id - 128; 172 } 173 entry = area + (idx * sizeof(struct cmg_entry)); 174 do { 175 memcpy(buf, entry, sizeof(*entry)); 176 memcpy(&reference_buf, entry, sizeof(*entry)); 177 } while (reference_buf.values[0] != buf->values[0]); 178 } 179 180 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj, 181 struct bin_attribute *bin_attr, 182 char *buf, loff_t off, size_t count) 183 { 184 struct channel_path *chp; 185 struct channel_subsystem *css; 186 struct device *device; 187 unsigned int size; 188 189 device = container_of(kobj, struct device, kobj); 190 chp = to_channelpath(device); 191 css = to_css(chp->dev.parent); 192 193 size = sizeof(struct cmg_entry); 194 195 /* Only allow single reads. */ 196 if (off || count < size) 197 return 0; 198 chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid); 199 count = size; 200 return count; 201 } 202 203 static struct bin_attribute chp_measurement_attr = { 204 .attr = { 205 .name = "measurement", 206 .mode = S_IRUSR, 207 }, 208 .size = sizeof(struct cmg_entry), 209 .read = chp_measurement_read, 210 }; 211 212 void chp_remove_cmg_attr(struct channel_path *chp) 213 { 214 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 215 device_remove_bin_file(&chp->dev, &chp_measurement_attr); 216 } 217 218 int chp_add_cmg_attr(struct channel_path *chp) 219 { 220 int ret; 221 222 ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr); 223 if (ret) 224 return ret; 225 ret = device_create_bin_file(&chp->dev, &chp_measurement_attr); 226 if (ret) 227 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 228 return ret; 229 } 230 231 /* 232 * Files for the channel path entries. 233 */ 234 static ssize_t chp_status_show(struct device *dev, 235 struct device_attribute *attr, char *buf) 236 { 237 struct channel_path *chp = to_channelpath(dev); 238 int status; 239 240 mutex_lock(&chp->lock); 241 status = chp->state; 242 mutex_unlock(&chp->lock); 243 244 return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n"); 245 } 246 247 static ssize_t chp_status_write(struct device *dev, 248 struct device_attribute *attr, 249 const char *buf, size_t count) 250 { 251 struct channel_path *cp = to_channelpath(dev); 252 char cmd[10]; 253 int num_args; 254 int error; 255 256 num_args = sscanf(buf, "%5s", cmd); 257 if (!num_args) 258 return count; 259 260 if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) { 261 mutex_lock(&cp->lock); 262 error = s390_vary_chpid(cp->chpid, 1); 263 mutex_unlock(&cp->lock); 264 } else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) { 265 mutex_lock(&cp->lock); 266 error = s390_vary_chpid(cp->chpid, 0); 267 mutex_unlock(&cp->lock); 268 } else 269 error = -EINVAL; 270 271 return error < 0 ? error : count; 272 } 273 274 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write); 275 276 static ssize_t chp_configure_show(struct device *dev, 277 struct device_attribute *attr, char *buf) 278 { 279 struct channel_path *cp; 280 int status; 281 282 cp = to_channelpath(dev); 283 status = chp_info_get_status(cp->chpid); 284 if (status < 0) 285 return status; 286 287 return snprintf(buf, PAGE_SIZE, "%d\n", status); 288 } 289 290 static int cfg_wait_idle(void); 291 292 static ssize_t chp_configure_write(struct device *dev, 293 struct device_attribute *attr, 294 const char *buf, size_t count) 295 { 296 struct channel_path *cp; 297 int val; 298 char delim; 299 300 if (sscanf(buf, "%d %c", &val, &delim) != 1) 301 return -EINVAL; 302 if (val != 0 && val != 1) 303 return -EINVAL; 304 cp = to_channelpath(dev); 305 chp_cfg_schedule(cp->chpid, val); 306 cfg_wait_idle(); 307 308 return count; 309 } 310 311 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write); 312 313 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr, 314 char *buf) 315 { 316 struct channel_path *chp = to_channelpath(dev); 317 u8 type; 318 319 mutex_lock(&chp->lock); 320 type = chp->desc.desc; 321 mutex_unlock(&chp->lock); 322 return sprintf(buf, "%x\n", type); 323 } 324 325 static DEVICE_ATTR(type, 0444, chp_type_show, NULL); 326 327 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr, 328 char *buf) 329 { 330 struct channel_path *chp = to_channelpath(dev); 331 332 if (!chp) 333 return 0; 334 if (chp->cmg == -1) /* channel measurements not available */ 335 return sprintf(buf, "unknown\n"); 336 return sprintf(buf, "%x\n", chp->cmg); 337 } 338 339 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL); 340 341 static ssize_t chp_shared_show(struct device *dev, 342 struct device_attribute *attr, char *buf) 343 { 344 struct channel_path *chp = to_channelpath(dev); 345 346 if (!chp) 347 return 0; 348 if (chp->shared == -1) /* channel measurements not available */ 349 return sprintf(buf, "unknown\n"); 350 return sprintf(buf, "%x\n", chp->shared); 351 } 352 353 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL); 354 355 static struct attribute *chp_attrs[] = { 356 &dev_attr_status.attr, 357 &dev_attr_configure.attr, 358 &dev_attr_type.attr, 359 &dev_attr_cmg.attr, 360 &dev_attr_shared.attr, 361 NULL, 362 }; 363 364 static struct attribute_group chp_attr_group = { 365 .attrs = chp_attrs, 366 }; 367 368 static void chp_release(struct device *dev) 369 { 370 struct channel_path *cp; 371 372 cp = to_channelpath(dev); 373 kfree(cp); 374 } 375 376 /** 377 * chp_new - register a new channel-path 378 * @chpid - channel-path ID 379 * 380 * Create and register data structure representing new channel-path. Return 381 * zero on success, non-zero otherwise. 382 */ 383 int chp_new(struct chp_id chpid) 384 { 385 struct channel_path *chp; 386 int ret; 387 388 if (chp_is_registered(chpid)) 389 return 0; 390 chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); 391 if (!chp) 392 return -ENOMEM; 393 394 /* fill in status, etc. */ 395 chp->chpid = chpid; 396 chp->state = 1; 397 chp->dev.parent = &channel_subsystems[chpid.cssid]->device; 398 chp->dev.release = chp_release; 399 mutex_init(&chp->lock); 400 401 /* Obtain channel path description and fill it in. */ 402 ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc); 403 if (ret) 404 goto out_free; 405 if ((chp->desc.flags & 0x80) == 0) { 406 ret = -ENODEV; 407 goto out_free; 408 } 409 /* Get channel-measurement characteristics. */ 410 if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) { 411 ret = chsc_get_channel_measurement_chars(chp); 412 if (ret) 413 goto out_free; 414 } else { 415 chp->cmg = -1; 416 } 417 dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id); 418 419 /* make it known to the system */ 420 ret = device_register(&chp->dev); 421 if (ret) { 422 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n", 423 chpid.cssid, chpid.id, ret); 424 put_device(&chp->dev); 425 goto out; 426 } 427 ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group); 428 if (ret) { 429 device_unregister(&chp->dev); 430 goto out; 431 } 432 mutex_lock(&channel_subsystems[chpid.cssid]->mutex); 433 if (channel_subsystems[chpid.cssid]->cm_enabled) { 434 ret = chp_add_cmg_attr(chp); 435 if (ret) { 436 sysfs_remove_group(&chp->dev.kobj, &chp_attr_group); 437 device_unregister(&chp->dev); 438 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); 439 goto out; 440 } 441 } 442 channel_subsystems[chpid.cssid]->chps[chpid.id] = chp; 443 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); 444 goto out; 445 out_free: 446 kfree(chp); 447 out: 448 return ret; 449 } 450 451 /** 452 * chp_get_chp_desc - return newly allocated channel-path description 453 * @chpid: channel-path ID 454 * 455 * On success return a newly allocated copy of the channel-path description 456 * data associated with the given channel-path ID. Return %NULL on error. 457 */ 458 void *chp_get_chp_desc(struct chp_id chpid) 459 { 460 struct channel_path *chp; 461 struct channel_path_desc *desc; 462 463 chp = chpid_to_chp(chpid); 464 if (!chp) 465 return NULL; 466 desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL); 467 if (!desc) 468 return NULL; 469 470 mutex_lock(&chp->lock); 471 memcpy(desc, &chp->desc, sizeof(struct channel_path_desc)); 472 mutex_unlock(&chp->lock); 473 return desc; 474 } 475 476 /** 477 * chp_process_crw - process channel-path status change 478 * @crw0: channel report-word to handler 479 * @crw1: second channel-report word (always NULL) 480 * @overflow: crw overflow indication 481 * 482 * Handle channel-report-words indicating that the status of a channel-path 483 * has changed. 484 */ 485 static void chp_process_crw(struct crw *crw0, struct crw *crw1, 486 int overflow) 487 { 488 struct chp_id chpid; 489 490 if (overflow) { 491 css_schedule_eval_all(); 492 return; 493 } 494 CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, " 495 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", 496 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc, 497 crw0->erc, crw0->rsid); 498 /* 499 * Check for solicited machine checks. These are 500 * created by reset channel path and need not be 501 * handled here. 502 */ 503 if (crw0->slct) { 504 CIO_CRW_EVENT(2, "solicited machine check for " 505 "channel path %02X\n", crw0->rsid); 506 return; 507 } 508 chp_id_init(&chpid); 509 chpid.id = crw0->rsid; 510 switch (crw0->erc) { 511 case CRW_ERC_IPARM: /* Path has come. */ 512 if (!chp_is_registered(chpid)) 513 chp_new(chpid); 514 chsc_chp_online(chpid); 515 break; 516 case CRW_ERC_PERRI: /* Path has gone. */ 517 case CRW_ERC_PERRN: 518 chsc_chp_offline(chpid); 519 break; 520 default: 521 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n", 522 crw0->erc); 523 } 524 } 525 526 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link) 527 { 528 int i; 529 int mask; 530 531 for (i = 0; i < 8; i++) { 532 mask = 0x80 >> i; 533 if (!(ssd->path_mask & mask)) 534 continue; 535 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid)) 536 continue; 537 if ((ssd->fla_valid_mask & mask) && 538 ((ssd->fla[i] & link->fla_mask) != link->fla)) 539 continue; 540 return mask; 541 } 542 return 0; 543 } 544 EXPORT_SYMBOL_GPL(chp_ssd_get_mask); 545 546 static inline int info_bit_num(struct chp_id id) 547 { 548 return id.id + id.cssid * (__MAX_CHPID + 1); 549 } 550 551 /* Force chp_info refresh on next call to info_validate(). */ 552 static void info_expire(void) 553 { 554 mutex_lock(&info_lock); 555 chp_info_expires = jiffies - 1; 556 mutex_unlock(&info_lock); 557 } 558 559 /* Ensure that chp_info is up-to-date. */ 560 static int info_update(void) 561 { 562 int rc; 563 564 mutex_lock(&info_lock); 565 rc = 0; 566 if (time_after(jiffies, chp_info_expires)) { 567 /* Data is too old, update. */ 568 rc = sclp_chp_read_info(&chp_info); 569 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ; 570 } 571 mutex_unlock(&info_lock); 572 573 return rc; 574 } 575 576 /** 577 * chp_info_get_status - retrieve configure status of a channel-path 578 * @chpid: channel-path ID 579 * 580 * On success, return 0 for standby, 1 for configured, 2 for reserved, 581 * 3 for not recognized. Return negative error code on error. 582 */ 583 int chp_info_get_status(struct chp_id chpid) 584 { 585 int rc; 586 int bit; 587 588 rc = info_update(); 589 if (rc) 590 return rc; 591 592 bit = info_bit_num(chpid); 593 mutex_lock(&info_lock); 594 if (!chp_test_bit(chp_info.recognized, bit)) 595 rc = CHP_STATUS_NOT_RECOGNIZED; 596 else if (chp_test_bit(chp_info.configured, bit)) 597 rc = CHP_STATUS_CONFIGURED; 598 else if (chp_test_bit(chp_info.standby, bit)) 599 rc = CHP_STATUS_STANDBY; 600 else 601 rc = CHP_STATUS_RESERVED; 602 mutex_unlock(&info_lock); 603 604 return rc; 605 } 606 607 /* Return configure task for chpid. */ 608 static enum cfg_task_t cfg_get_task(struct chp_id chpid) 609 { 610 return chp_cfg_task[chpid.cssid][chpid.id]; 611 } 612 613 /* Set configure task for chpid. */ 614 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg) 615 { 616 chp_cfg_task[chpid.cssid][chpid.id] = cfg; 617 } 618 619 /* Perform one configure/deconfigure request. Reschedule work function until 620 * last request. */ 621 static void cfg_func(struct work_struct *work) 622 { 623 struct chp_id chpid; 624 enum cfg_task_t t; 625 int rc; 626 627 mutex_lock(&cfg_lock); 628 t = cfg_none; 629 chp_id_for_each(&chpid) { 630 t = cfg_get_task(chpid); 631 if (t != cfg_none) { 632 cfg_set_task(chpid, cfg_none); 633 break; 634 } 635 } 636 mutex_unlock(&cfg_lock); 637 638 switch (t) { 639 case cfg_configure: 640 rc = sclp_chp_configure(chpid); 641 if (rc) 642 CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)=" 643 "%d\n", chpid.cssid, chpid.id, rc); 644 else { 645 info_expire(); 646 chsc_chp_online(chpid); 647 } 648 break; 649 case cfg_deconfigure: 650 rc = sclp_chp_deconfigure(chpid); 651 if (rc) 652 CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)=" 653 "%d\n", chpid.cssid, chpid.id, rc); 654 else { 655 info_expire(); 656 chsc_chp_offline(chpid); 657 } 658 break; 659 case cfg_none: 660 /* Get updated information after last change. */ 661 info_update(); 662 mutex_lock(&cfg_lock); 663 cfg_busy = 0; 664 mutex_unlock(&cfg_lock); 665 wake_up_interruptible(&cfg_wait_queue); 666 return; 667 } 668 queue_work(chp_wq, &cfg_work); 669 } 670 671 /** 672 * chp_cfg_schedule - schedule chpid configuration request 673 * @chpid - channel-path ID 674 * @configure - Non-zero for configure, zero for deconfigure 675 * 676 * Schedule a channel-path configuration/deconfiguration request. 677 */ 678 void chp_cfg_schedule(struct chp_id chpid, int configure) 679 { 680 CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id, 681 configure); 682 mutex_lock(&cfg_lock); 683 cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); 684 cfg_busy = 1; 685 mutex_unlock(&cfg_lock); 686 queue_work(chp_wq, &cfg_work); 687 } 688 689 /** 690 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request 691 * @chpid - channel-path ID 692 * 693 * Cancel an active channel-path deconfiguration request if it has not yet 694 * been performed. 695 */ 696 void chp_cfg_cancel_deconfigure(struct chp_id chpid) 697 { 698 CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id); 699 mutex_lock(&cfg_lock); 700 if (cfg_get_task(chpid) == cfg_deconfigure) 701 cfg_set_task(chpid, cfg_none); 702 mutex_unlock(&cfg_lock); 703 } 704 705 static int cfg_wait_idle(void) 706 { 707 if (wait_event_interruptible(cfg_wait_queue, !cfg_busy)) 708 return -ERESTARTSYS; 709 return 0; 710 } 711 712 static int __init chp_init(void) 713 { 714 struct chp_id chpid; 715 int ret; 716 717 ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw); 718 if (ret) 719 return ret; 720 chp_wq = create_singlethread_workqueue("cio_chp"); 721 if (!chp_wq) { 722 crw_unregister_handler(CRW_RSC_CPATH); 723 return -ENOMEM; 724 } 725 INIT_WORK(&cfg_work, cfg_func); 726 init_waitqueue_head(&cfg_wait_queue); 727 if (info_update()) 728 return 0; 729 /* Register available channel-paths. */ 730 chp_id_for_each(&chpid) { 731 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED) 732 chp_new(chpid); 733 } 734 735 return 0; 736 } 737 738 subsys_initcall(chp_init); 739