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/export.h> 14 #include <linux/sched.h> 15 #include <linux/init.h> 16 #include <linux/jiffies.h> 17 #include <linux/wait.h> 18 #include <linux/mutex.h> 19 #include <linux/errno.h> 20 #include <linux/slab.h> 21 #include <asm/chpid.h> 22 #include <asm/sclp.h> 23 #include <asm/crw.h> 24 25 #include "cio.h" 26 #include "css.h" 27 #include "ioasm.h" 28 #include "cio_debug.h" 29 #include "chp.h" 30 31 #define to_channelpath(device) container_of(device, struct channel_path, dev) 32 #define CHP_INFO_UPDATE_INTERVAL 1*HZ 33 34 enum cfg_task_t { 35 cfg_none, 36 cfg_configure, 37 cfg_deconfigure 38 }; 39 40 /* Map for pending configure tasks. */ 41 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1]; 42 static DEFINE_MUTEX(cfg_lock); 43 static int cfg_busy; 44 45 /* Map for channel-path status. */ 46 static struct sclp_chp_info chp_info; 47 static DEFINE_MUTEX(info_lock); 48 49 /* Time after which channel-path status may be outdated. */ 50 static unsigned long chp_info_expires; 51 52 /* Workqueue to perform pending configure tasks. */ 53 static struct workqueue_struct *chp_wq; 54 static struct work_struct cfg_work; 55 56 /* Wait queue for configure completion events. */ 57 static wait_queue_head_t cfg_wait_queue; 58 59 /* Set vary state for given chpid. */ 60 static void set_chp_logically_online(struct chp_id chpid, int onoff) 61 { 62 chpid_to_chp(chpid)->state = onoff; 63 } 64 65 /* On success return 0 if channel-path is varied offline, 1 if it is varied 66 * online. Return -ENODEV if channel-path is not registered. */ 67 int chp_get_status(struct chp_id chpid) 68 { 69 return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV); 70 } 71 72 /** 73 * chp_get_sch_opm - return opm for subchannel 74 * @sch: subchannel 75 * 76 * Calculate and return the operational path mask (opm) based on the chpids 77 * used by the subchannel and the status of the associated channel-paths. 78 */ 79 u8 chp_get_sch_opm(struct subchannel *sch) 80 { 81 struct chp_id chpid; 82 int opm; 83 int i; 84 85 opm = 0; 86 chp_id_init(&chpid); 87 for (i = 0; i < 8; i++) { 88 opm <<= 1; 89 chpid.id = sch->schib.pmcw.chpid[i]; 90 if (chp_get_status(chpid) != 0) 91 opm |= 1; 92 } 93 return opm; 94 } 95 EXPORT_SYMBOL_GPL(chp_get_sch_opm); 96 97 /** 98 * chp_is_registered - check if a channel-path is registered 99 * @chpid: channel-path ID 100 * 101 * Return non-zero if a channel-path with the given chpid is registered, 102 * zero otherwise. 103 */ 104 int chp_is_registered(struct chp_id chpid) 105 { 106 return chpid_to_chp(chpid) != NULL; 107 } 108 109 /* 110 * Function: s390_vary_chpid 111 * Varies the specified chpid online or offline 112 */ 113 static int s390_vary_chpid(struct chp_id chpid, int on) 114 { 115 char dbf_text[15]; 116 int status; 117 118 sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid, 119 chpid.id); 120 CIO_TRACE_EVENT(2, dbf_text); 121 122 status = chp_get_status(chpid); 123 if (!on && !status) 124 return 0; 125 126 set_chp_logically_online(chpid, on); 127 chsc_chp_vary(chpid, on); 128 return 0; 129 } 130 131 /* 132 * Channel measurement related functions 133 */ 134 static ssize_t chp_measurement_chars_read(struct file *filp, 135 struct kobject *kobj, 136 struct bin_attribute *bin_attr, 137 char *buf, loff_t off, size_t count) 138 { 139 struct channel_path *chp; 140 struct device *device; 141 142 device = container_of(kobj, struct device, kobj); 143 chp = to_channelpath(device); 144 if (!chp->cmg_chars) 145 return 0; 146 147 return memory_read_from_buffer(buf, count, &off, 148 chp->cmg_chars, sizeof(struct cmg_chars)); 149 } 150 151 static struct bin_attribute chp_measurement_chars_attr = { 152 .attr = { 153 .name = "measurement_chars", 154 .mode = S_IRUSR, 155 }, 156 .size = sizeof(struct cmg_chars), 157 .read = chp_measurement_chars_read, 158 }; 159 160 static void chp_measurement_copy_block(struct cmg_entry *buf, 161 struct channel_subsystem *css, 162 struct chp_id chpid) 163 { 164 void *area; 165 struct cmg_entry *entry, reference_buf; 166 int idx; 167 168 if (chpid.id < 128) { 169 area = css->cub_addr1; 170 idx = chpid.id; 171 } else { 172 area = css->cub_addr2; 173 idx = chpid.id - 128; 174 } 175 entry = area + (idx * sizeof(struct cmg_entry)); 176 do { 177 memcpy(buf, entry, sizeof(*entry)); 178 memcpy(&reference_buf, entry, sizeof(*entry)); 179 } while (reference_buf.values[0] != buf->values[0]); 180 } 181 182 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj, 183 struct bin_attribute *bin_attr, 184 char *buf, loff_t off, size_t count) 185 { 186 struct channel_path *chp; 187 struct channel_subsystem *css; 188 struct device *device; 189 unsigned int size; 190 191 device = container_of(kobj, struct device, kobj); 192 chp = to_channelpath(device); 193 css = to_css(chp->dev.parent); 194 195 size = sizeof(struct cmg_entry); 196 197 /* Only allow single reads. */ 198 if (off || count < size) 199 return 0; 200 chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid); 201 count = size; 202 return count; 203 } 204 205 static struct bin_attribute chp_measurement_attr = { 206 .attr = { 207 .name = "measurement", 208 .mode = S_IRUSR, 209 }, 210 .size = sizeof(struct cmg_entry), 211 .read = chp_measurement_read, 212 }; 213 214 void chp_remove_cmg_attr(struct channel_path *chp) 215 { 216 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 217 device_remove_bin_file(&chp->dev, &chp_measurement_attr); 218 } 219 220 int chp_add_cmg_attr(struct channel_path *chp) 221 { 222 int ret; 223 224 ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr); 225 if (ret) 226 return ret; 227 ret = device_create_bin_file(&chp->dev, &chp_measurement_attr); 228 if (ret) 229 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 230 return ret; 231 } 232 233 /* 234 * Files for the channel path entries. 235 */ 236 static ssize_t chp_status_show(struct device *dev, 237 struct device_attribute *attr, char *buf) 238 { 239 struct channel_path *chp = to_channelpath(dev); 240 int status; 241 242 mutex_lock(&chp->lock); 243 status = chp->state; 244 mutex_unlock(&chp->lock); 245 246 return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n"); 247 } 248 249 static ssize_t chp_status_write(struct device *dev, 250 struct device_attribute *attr, 251 const char *buf, size_t count) 252 { 253 struct channel_path *cp = to_channelpath(dev); 254 char cmd[10]; 255 int num_args; 256 int error; 257 258 num_args = sscanf(buf, "%5s", cmd); 259 if (!num_args) 260 return count; 261 262 if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) { 263 mutex_lock(&cp->lock); 264 error = s390_vary_chpid(cp->chpid, 1); 265 mutex_unlock(&cp->lock); 266 } else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) { 267 mutex_lock(&cp->lock); 268 error = s390_vary_chpid(cp->chpid, 0); 269 mutex_unlock(&cp->lock); 270 } else 271 error = -EINVAL; 272 273 return error < 0 ? error : count; 274 } 275 276 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write); 277 278 static ssize_t chp_configure_show(struct device *dev, 279 struct device_attribute *attr, char *buf) 280 { 281 struct channel_path *cp; 282 int status; 283 284 cp = to_channelpath(dev); 285 status = chp_info_get_status(cp->chpid); 286 if (status < 0) 287 return status; 288 289 return snprintf(buf, PAGE_SIZE, "%d\n", status); 290 } 291 292 static int cfg_wait_idle(void); 293 294 static ssize_t chp_configure_write(struct device *dev, 295 struct device_attribute *attr, 296 const char *buf, size_t count) 297 { 298 struct channel_path *cp; 299 int val; 300 char delim; 301 302 if (sscanf(buf, "%d %c", &val, &delim) != 1) 303 return -EINVAL; 304 if (val != 0 && val != 1) 305 return -EINVAL; 306 cp = to_channelpath(dev); 307 chp_cfg_schedule(cp->chpid, val); 308 cfg_wait_idle(); 309 310 return count; 311 } 312 313 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write); 314 315 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr, 316 char *buf) 317 { 318 struct channel_path *chp = to_channelpath(dev); 319 u8 type; 320 321 mutex_lock(&chp->lock); 322 type = chp->desc.desc; 323 mutex_unlock(&chp->lock); 324 return sprintf(buf, "%x\n", type); 325 } 326 327 static DEVICE_ATTR(type, 0444, chp_type_show, NULL); 328 329 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr, 330 char *buf) 331 { 332 struct channel_path *chp = to_channelpath(dev); 333 334 if (!chp) 335 return 0; 336 if (chp->cmg == -1) /* channel measurements not available */ 337 return sprintf(buf, "unknown\n"); 338 return sprintf(buf, "%x\n", chp->cmg); 339 } 340 341 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL); 342 343 static ssize_t chp_shared_show(struct device *dev, 344 struct device_attribute *attr, char *buf) 345 { 346 struct channel_path *chp = to_channelpath(dev); 347 348 if (!chp) 349 return 0; 350 if (chp->shared == -1) /* channel measurements not available */ 351 return sprintf(buf, "unknown\n"); 352 return sprintf(buf, "%x\n", chp->shared); 353 } 354 355 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL); 356 357 static struct attribute *chp_attrs[] = { 358 &dev_attr_status.attr, 359 &dev_attr_configure.attr, 360 &dev_attr_type.attr, 361 &dev_attr_cmg.attr, 362 &dev_attr_shared.attr, 363 NULL, 364 }; 365 366 static struct attribute_group chp_attr_group = { 367 .attrs = chp_attrs, 368 }; 369 370 static void chp_release(struct device *dev) 371 { 372 struct channel_path *cp; 373 374 cp = to_channelpath(dev); 375 kfree(cp); 376 } 377 378 /** 379 * chp_new - register a new channel-path 380 * @chpid - channel-path ID 381 * 382 * Create and register data structure representing new channel-path. Return 383 * zero on success, non-zero otherwise. 384 */ 385 int chp_new(struct chp_id chpid) 386 { 387 struct channel_path *chp; 388 int ret; 389 390 if (chp_is_registered(chpid)) 391 return 0; 392 chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); 393 if (!chp) 394 return -ENOMEM; 395 396 /* fill in status, etc. */ 397 chp->chpid = chpid; 398 chp->state = 1; 399 chp->dev.parent = &channel_subsystems[chpid.cssid]->device; 400 chp->dev.release = chp_release; 401 mutex_init(&chp->lock); 402 403 /* Obtain channel path description and fill it in. */ 404 ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc); 405 if (ret) 406 goto out_free; 407 if ((chp->desc.flags & 0x80) == 0) { 408 ret = -ENODEV; 409 goto out_free; 410 } 411 /* Get channel-measurement characteristics. */ 412 if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) { 413 ret = chsc_get_channel_measurement_chars(chp); 414 if (ret) 415 goto out_free; 416 } else { 417 chp->cmg = -1; 418 } 419 dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id); 420 421 /* make it known to the system */ 422 ret = device_register(&chp->dev); 423 if (ret) { 424 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n", 425 chpid.cssid, chpid.id, ret); 426 put_device(&chp->dev); 427 goto out; 428 } 429 ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group); 430 if (ret) { 431 device_unregister(&chp->dev); 432 goto out; 433 } 434 mutex_lock(&channel_subsystems[chpid.cssid]->mutex); 435 if (channel_subsystems[chpid.cssid]->cm_enabled) { 436 ret = chp_add_cmg_attr(chp); 437 if (ret) { 438 sysfs_remove_group(&chp->dev.kobj, &chp_attr_group); 439 device_unregister(&chp->dev); 440 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); 441 goto out; 442 } 443 } 444 channel_subsystems[chpid.cssid]->chps[chpid.id] = chp; 445 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); 446 goto out; 447 out_free: 448 kfree(chp); 449 out: 450 return ret; 451 } 452 453 /** 454 * chp_get_chp_desc - return newly allocated channel-path description 455 * @chpid: channel-path ID 456 * 457 * On success return a newly allocated copy of the channel-path description 458 * data associated with the given channel-path ID. Return %NULL on error. 459 */ 460 void *chp_get_chp_desc(struct chp_id chpid) 461 { 462 struct channel_path *chp; 463 struct channel_path_desc *desc; 464 465 chp = chpid_to_chp(chpid); 466 if (!chp) 467 return NULL; 468 desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL); 469 if (!desc) 470 return NULL; 471 472 mutex_lock(&chp->lock); 473 memcpy(desc, &chp->desc, sizeof(struct channel_path_desc)); 474 mutex_unlock(&chp->lock); 475 return desc; 476 } 477 478 /** 479 * chp_process_crw - process channel-path status change 480 * @crw0: channel report-word to handler 481 * @crw1: second channel-report word (always NULL) 482 * @overflow: crw overflow indication 483 * 484 * Handle channel-report-words indicating that the status of a channel-path 485 * has changed. 486 */ 487 static void chp_process_crw(struct crw *crw0, struct crw *crw1, 488 int overflow) 489 { 490 struct chp_id chpid; 491 492 if (overflow) { 493 css_schedule_eval_all(); 494 return; 495 } 496 CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, " 497 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", 498 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc, 499 crw0->erc, crw0->rsid); 500 /* 501 * Check for solicited machine checks. These are 502 * created by reset channel path and need not be 503 * handled here. 504 */ 505 if (crw0->slct) { 506 CIO_CRW_EVENT(2, "solicited machine check for " 507 "channel path %02X\n", crw0->rsid); 508 return; 509 } 510 chp_id_init(&chpid); 511 chpid.id = crw0->rsid; 512 switch (crw0->erc) { 513 case CRW_ERC_IPARM: /* Path has come. */ 514 if (!chp_is_registered(chpid)) 515 chp_new(chpid); 516 chsc_chp_online(chpid); 517 break; 518 case CRW_ERC_PERRI: /* Path has gone. */ 519 case CRW_ERC_PERRN: 520 chsc_chp_offline(chpid); 521 break; 522 default: 523 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n", 524 crw0->erc); 525 } 526 } 527 528 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link) 529 { 530 int i; 531 int mask; 532 533 for (i = 0; i < 8; i++) { 534 mask = 0x80 >> i; 535 if (!(ssd->path_mask & mask)) 536 continue; 537 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid)) 538 continue; 539 if ((ssd->fla_valid_mask & mask) && 540 ((ssd->fla[i] & link->fla_mask) != link->fla)) 541 continue; 542 return mask; 543 } 544 return 0; 545 } 546 EXPORT_SYMBOL_GPL(chp_ssd_get_mask); 547 548 static inline int info_bit_num(struct chp_id id) 549 { 550 return id.id + id.cssid * (__MAX_CHPID + 1); 551 } 552 553 /* Force chp_info refresh on next call to info_validate(). */ 554 static void info_expire(void) 555 { 556 mutex_lock(&info_lock); 557 chp_info_expires = jiffies - 1; 558 mutex_unlock(&info_lock); 559 } 560 561 /* Ensure that chp_info is up-to-date. */ 562 static int info_update(void) 563 { 564 int rc; 565 566 mutex_lock(&info_lock); 567 rc = 0; 568 if (time_after(jiffies, chp_info_expires)) { 569 /* Data is too old, update. */ 570 rc = sclp_chp_read_info(&chp_info); 571 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ; 572 } 573 mutex_unlock(&info_lock); 574 575 return rc; 576 } 577 578 /** 579 * chp_info_get_status - retrieve configure status of a channel-path 580 * @chpid: channel-path ID 581 * 582 * On success, return 0 for standby, 1 for configured, 2 for reserved, 583 * 3 for not recognized. Return negative error code on error. 584 */ 585 int chp_info_get_status(struct chp_id chpid) 586 { 587 int rc; 588 int bit; 589 590 rc = info_update(); 591 if (rc) 592 return rc; 593 594 bit = info_bit_num(chpid); 595 mutex_lock(&info_lock); 596 if (!chp_test_bit(chp_info.recognized, bit)) 597 rc = CHP_STATUS_NOT_RECOGNIZED; 598 else if (chp_test_bit(chp_info.configured, bit)) 599 rc = CHP_STATUS_CONFIGURED; 600 else if (chp_test_bit(chp_info.standby, bit)) 601 rc = CHP_STATUS_STANDBY; 602 else 603 rc = CHP_STATUS_RESERVED; 604 mutex_unlock(&info_lock); 605 606 return rc; 607 } 608 609 /* Return configure task for chpid. */ 610 static enum cfg_task_t cfg_get_task(struct chp_id chpid) 611 { 612 return chp_cfg_task[chpid.cssid][chpid.id]; 613 } 614 615 /* Set configure task for chpid. */ 616 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg) 617 { 618 chp_cfg_task[chpid.cssid][chpid.id] = cfg; 619 } 620 621 /* Perform one configure/deconfigure request. Reschedule work function until 622 * last request. */ 623 static void cfg_func(struct work_struct *work) 624 { 625 struct chp_id chpid; 626 enum cfg_task_t t; 627 int rc; 628 629 mutex_lock(&cfg_lock); 630 t = cfg_none; 631 chp_id_for_each(&chpid) { 632 t = cfg_get_task(chpid); 633 if (t != cfg_none) { 634 cfg_set_task(chpid, cfg_none); 635 break; 636 } 637 } 638 mutex_unlock(&cfg_lock); 639 640 switch (t) { 641 case cfg_configure: 642 rc = sclp_chp_configure(chpid); 643 if (rc) 644 CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)=" 645 "%d\n", chpid.cssid, chpid.id, rc); 646 else { 647 info_expire(); 648 chsc_chp_online(chpid); 649 } 650 break; 651 case cfg_deconfigure: 652 rc = sclp_chp_deconfigure(chpid); 653 if (rc) 654 CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)=" 655 "%d\n", chpid.cssid, chpid.id, rc); 656 else { 657 info_expire(); 658 chsc_chp_offline(chpid); 659 } 660 break; 661 case cfg_none: 662 /* Get updated information after last change. */ 663 info_update(); 664 mutex_lock(&cfg_lock); 665 cfg_busy = 0; 666 mutex_unlock(&cfg_lock); 667 wake_up_interruptible(&cfg_wait_queue); 668 return; 669 } 670 queue_work(chp_wq, &cfg_work); 671 } 672 673 /** 674 * chp_cfg_schedule - schedule chpid configuration request 675 * @chpid - channel-path ID 676 * @configure - Non-zero for configure, zero for deconfigure 677 * 678 * Schedule a channel-path configuration/deconfiguration request. 679 */ 680 void chp_cfg_schedule(struct chp_id chpid, int configure) 681 { 682 CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id, 683 configure); 684 mutex_lock(&cfg_lock); 685 cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); 686 cfg_busy = 1; 687 mutex_unlock(&cfg_lock); 688 queue_work(chp_wq, &cfg_work); 689 } 690 691 /** 692 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request 693 * @chpid - channel-path ID 694 * 695 * Cancel an active channel-path deconfiguration request if it has not yet 696 * been performed. 697 */ 698 void chp_cfg_cancel_deconfigure(struct chp_id chpid) 699 { 700 CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id); 701 mutex_lock(&cfg_lock); 702 if (cfg_get_task(chpid) == cfg_deconfigure) 703 cfg_set_task(chpid, cfg_none); 704 mutex_unlock(&cfg_lock); 705 } 706 707 static int cfg_wait_idle(void) 708 { 709 if (wait_event_interruptible(cfg_wait_queue, !cfg_busy)) 710 return -ERESTARTSYS; 711 return 0; 712 } 713 714 static int __init chp_init(void) 715 { 716 struct chp_id chpid; 717 int ret; 718 719 ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw); 720 if (ret) 721 return ret; 722 chp_wq = create_singlethread_workqueue("cio_chp"); 723 if (!chp_wq) { 724 crw_unregister_handler(CRW_RSC_CPATH); 725 return -ENOMEM; 726 } 727 INIT_WORK(&cfg_work, cfg_func); 728 init_waitqueue_head(&cfg_wait_queue); 729 if (info_update()) 730 return 0; 731 /* Register available channel-paths. */ 732 chp_id_for_each(&chpid) { 733 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED) 734 chp_new(chpid); 735 } 736 737 return 0; 738 } 739 740 subsys_initcall(chp_init); 741