1/* 2 * drivers/s390/cio/chp.c 3 * 4 * Copyright IBM Corp. 1999,2007 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 32enum cfg_task_t { 33 cfg_none, 34 cfg_configure, 35 cfg_deconfigure 36}; 37 38/* Map for pending configure tasks. */ 39static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1]; 40static DEFINE_MUTEX(cfg_lock); 41static int cfg_busy; 42 43/* Map for channel-path status. */ 44static struct sclp_chp_info chp_info; 45static DEFINE_MUTEX(info_lock); 46 47/* Time after which channel-path status may be outdated. */ 48static unsigned long chp_info_expires; 49 50/* Workqueue to perform pending configure tasks. */ 51static struct workqueue_struct *chp_wq; 52static struct work_struct cfg_work; 53 54/* Wait queue for configure completion events. */ 55static wait_queue_head_t cfg_wait_queue; 56 57/* Return channel_path struct for given chpid. */ 58static inline struct channel_path *chpid_to_chp(struct chp_id chpid) 59{ 60 return channel_subsystems[chpid.cssid]->chps[chpid.id]; 61} 62 63/* Set vary state for given chpid. */ 64static void set_chp_logically_online(struct chp_id chpid, int onoff) 65{ 66 chpid_to_chp(chpid)->state = onoff; 67} 68 69/* On success return 0 if channel-path is varied offline, 1 if it is varied 70 * online. Return -ENODEV if channel-path is not registered. */ 71int chp_get_status(struct chp_id chpid) 72{ 73 return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV); 74} 75 76/** 77 * chp_get_sch_opm - return opm for subchannel 78 * @sch: subchannel 79 * 80 * Calculate and return the operational path mask (opm) based on the chpids 81 * used by the subchannel and the status of the associated channel-paths. 82 */ 83u8 chp_get_sch_opm(struct subchannel *sch) 84{ 85 struct chp_id chpid; 86 int opm; 87 int i; 88 89 opm = 0; 90 chp_id_init(&chpid); 91 for (i = 0; i < 8; i++) { 92 opm <<= 1; 93 chpid.id = sch->schib.pmcw.chpid[i]; 94 if (chp_get_status(chpid) != 0) 95 opm |= 1; 96 } 97 return opm; 98} 99EXPORT_SYMBOL_GPL(chp_get_sch_opm); 100 101/** 102 * chp_is_registered - check if a channel-path is registered 103 * @chpid: channel-path ID 104 * 105 * Return non-zero if a channel-path with the given chpid is registered, 106 * zero otherwise. 107 */ 108int chp_is_registered(struct chp_id chpid) 109{ 110 return chpid_to_chp(chpid) != NULL; 111} 112 113/* 114 * Function: s390_vary_chpid 115 * Varies the specified chpid online or offline 116 */ 117static int s390_vary_chpid(struct chp_id chpid, int on) 118{ 119 char dbf_text[15]; 120 int status; 121 122 sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid, 123 chpid.id); 124 CIO_TRACE_EVENT(2, dbf_text); 125 126 status = chp_get_status(chpid); 127 if (!on && !status) 128 return 0; 129 130 set_chp_logically_online(chpid, on); 131 chsc_chp_vary(chpid, on); 132 return 0; 133} 134 135/* 136 * Channel measurement related functions 137 */ 138static ssize_t chp_measurement_chars_read(struct file *filp, 139 struct kobject *kobj, 140 struct bin_attribute *bin_attr, 141 char *buf, loff_t off, size_t count) 142{ 143 struct channel_path *chp; 144 struct device *device; 145 146 device = container_of(kobj, struct device, kobj); 147 chp = to_channelpath(device); 148 if (!chp->cmg_chars) 149 return 0; 150 151 return memory_read_from_buffer(buf, count, &off, 152 chp->cmg_chars, sizeof(struct cmg_chars)); 153} 154 155static struct bin_attribute chp_measurement_chars_attr = { 156 .attr = { 157 .name = "measurement_chars", 158 .mode = S_IRUSR, 159 }, 160 .size = sizeof(struct cmg_chars), 161 .read = chp_measurement_chars_read, 162}; 163 164static void chp_measurement_copy_block(struct cmg_entry *buf, 165 struct channel_subsystem *css, 166 struct chp_id chpid) 167{ 168 void *area; 169 struct cmg_entry *entry, reference_buf; 170 int idx; 171 172 if (chpid.id < 128) { 173 area = css->cub_addr1; 174 idx = chpid.id; 175 } else { 176 area = css->cub_addr2; 177 idx = chpid.id - 128; 178 } 179 entry = area + (idx * sizeof(struct cmg_entry)); 180 do { 181 memcpy(buf, entry, sizeof(*entry)); 182 memcpy(&reference_buf, entry, sizeof(*entry)); 183 } while (reference_buf.values[0] != buf->values[0]); 184} 185 186static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj, 187 struct bin_attribute *bin_attr, 188 char *buf, loff_t off, size_t count) 189{ 190 struct channel_path *chp; 191 struct channel_subsystem *css; 192 struct device *device; 193 unsigned int size; 194 195 device = container_of(kobj, struct device, kobj); 196 chp = to_channelpath(device); 197 css = to_css(chp->dev.parent); 198 199 size = sizeof(struct cmg_entry); 200 201 /* Only allow single reads. */ 202 if (off || count < size) 203 return 0; 204 chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid); 205 count = size; 206 return count; 207} 208 209static struct bin_attribute chp_measurement_attr = { 210 .attr = { 211 .name = "measurement", 212 .mode = S_IRUSR, 213 }, 214 .size = sizeof(struct cmg_entry), 215 .read = chp_measurement_read, 216}; 217 218void chp_remove_cmg_attr(struct channel_path *chp) 219{ 220 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 221 device_remove_bin_file(&chp->dev, &chp_measurement_attr); 222} 223 224int chp_add_cmg_attr(struct channel_path *chp) 225{ 226 int ret; 227 228 ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr); 229 if (ret) 230 return ret; 231 ret = device_create_bin_file(&chp->dev, &chp_measurement_attr); 232 if (ret) 233 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 234 return ret; 235} 236 237/* 238 * Files for the channel path entries. 239 */ 240static ssize_t chp_status_show(struct device *dev, 241 struct device_attribute *attr, char *buf) 242{ 243 struct channel_path *chp = to_channelpath(dev); 244 245 if (!chp) 246 return 0; 247 return (chp_get_status(chp->chpid) ? sprintf(buf, "online\n") : 248 sprintf(buf, "offline\n")); 249} 250 251static ssize_t chp_status_write(struct device *dev, 252 struct device_attribute *attr, 253 const char *buf, size_t count) 254{ 255 struct channel_path *cp = to_channelpath(dev); 256 char cmd[10]; 257 int num_args; 258 int error; 259 260 num_args = sscanf(buf, "%5s", cmd); 261 if (!num_args) 262 return count; 263 264 if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) 265 error = s390_vary_chpid(cp->chpid, 1); 266 else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) 267 error = s390_vary_chpid(cp->chpid, 0); 268 else 269 error = -EINVAL; 270 271 return error < 0 ? error : count; 272 273} 274 275static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write); 276 277static ssize_t chp_configure_show(struct device *dev, 278 struct device_attribute *attr, char *buf) 279{ 280 struct channel_path *cp; 281 int status; 282 283 cp = to_channelpath(dev); 284 status = chp_info_get_status(cp->chpid); 285 if (status < 0) 286 return status; 287 288 return snprintf(buf, PAGE_SIZE, "%d\n", status); 289} 290 291static int cfg_wait_idle(void); 292 293static ssize_t chp_configure_write(struct device *dev, 294 struct device_attribute *attr, 295 const char *buf, size_t count) 296{ 297 struct channel_path *cp; 298 int val; 299 char delim; 300 301 if (sscanf(buf, "%d %c", &val, &delim) != 1) 302 return -EINVAL; 303 if (val != 0 && val != 1) 304 return -EINVAL; 305 cp = to_channelpath(dev); 306 chp_cfg_schedule(cp->chpid, val); 307 cfg_wait_idle(); 308 309 return count; 310} 311 312static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write); 313 314static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr, 315 char *buf) 316{ 317 struct channel_path *chp = to_channelpath(dev); 318 319 if (!chp) 320 return 0; 321 return sprintf(buf, "%x\n", chp->desc.desc); 322} 323 324static DEVICE_ATTR(type, 0444, chp_type_show, NULL); 325 326static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr, 327 char *buf) 328{ 329 struct channel_path *chp = to_channelpath(dev); 330 331 if (!chp) 332 return 0; 333 if (chp->cmg == -1) /* channel measurements not available */ 334 return sprintf(buf, "unknown\n"); 335 return sprintf(buf, "%x\n", chp->cmg); 336} 337 338static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL); 339 340static ssize_t chp_shared_show(struct device *dev, 341 struct device_attribute *attr, char *buf) 342{ 343 struct channel_path *chp = to_channelpath(dev); 344 345 if (!chp) 346 return 0; 347 if (chp->shared == -1) /* channel measurements not available */ 348 return sprintf(buf, "unknown\n"); 349 return sprintf(buf, "%x\n", chp->shared); 350} 351 352static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL); 353 354static struct attribute *chp_attrs[] = { 355 &dev_attr_status.attr, 356 &dev_attr_configure.attr, 357 &dev_attr_type.attr, 358 &dev_attr_cmg.attr, 359 &dev_attr_shared.attr, 360 NULL, 361}; 362 363static struct attribute_group chp_attr_group = { 364 .attrs = chp_attrs, 365}; 366 367static void chp_release(struct device *dev) 368{ 369 struct channel_path *cp; 370 371 cp = to_channelpath(dev); 372 kfree(cp); 373} 374 375/** 376 * chp_new - register a new channel-path 377 * @chpid - channel-path ID 378 * 379 * Create and register data structure representing new channel-path. Return 380 * zero on success, non-zero otherwise. 381 */ 382int chp_new(struct chp_id chpid) 383{ 384 struct channel_path *chp; 385 int ret; 386 387 if (chp_is_registered(chpid)) 388 return 0; 389 chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); 390 if (!chp) 391 return -ENOMEM; 392 393 /* fill in status, etc. */ 394 chp->chpid = chpid; 395 chp->state = 1; 396 chp->dev.parent = &channel_subsystems[chpid.cssid]->device; 397 chp->dev.release = chp_release; 398 399 /* Obtain channel path description and fill it in. */ 400 ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc); 401 if (ret) 402 goto out_free; 403 if ((chp->desc.flags & 0x80) == 0) { 404 ret = -ENODEV; 405 goto out_free; 406 } 407 /* Get channel-measurement characteristics. */ 408 if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) { 409 ret = chsc_get_channel_measurement_chars(chp); 410 if (ret) 411 goto out_free; 412 } else { 413 chp->cmg = -1; 414 } 415 dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id); 416 417 /* make it known to the system */ 418 ret = device_register(&chp->dev); 419 if (ret) { 420 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n", 421 chpid.cssid, chpid.id, ret); 422 put_device(&chp->dev); 423 goto out; 424 } 425 ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group); 426 if (ret) { 427 device_unregister(&chp->dev); 428 goto out; 429 } 430 mutex_lock(&channel_subsystems[chpid.cssid]->mutex); 431 if (channel_subsystems[chpid.cssid]->cm_enabled) { 432 ret = chp_add_cmg_attr(chp); 433 if (ret) { 434 sysfs_remove_group(&chp->dev.kobj, &chp_attr_group); 435 device_unregister(&chp->dev); 436 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); 437 goto out; 438 } 439 } 440 channel_subsystems[chpid.cssid]->chps[chpid.id] = chp; 441 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); 442 goto out; 443out_free: 444 kfree(chp); 445out: 446 return ret; 447} 448 449/** 450 * chp_get_chp_desc - return newly allocated channel-path description 451 * @chpid: channel-path ID 452 * 453 * On success return a newly allocated copy of the channel-path description 454 * data associated with the given channel-path ID. Return %NULL on error. 455 */ 456void *chp_get_chp_desc(struct chp_id chpid) 457{ 458 struct channel_path *chp; 459 struct channel_path_desc *desc; 460 461 chp = chpid_to_chp(chpid); 462 if (!chp) 463 return NULL; 464 desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL); 465 if (!desc) 466 return NULL; 467 memcpy(desc, &chp->desc, sizeof(struct channel_path_desc)); 468 return desc; 469} 470 471/** 472 * chp_process_crw - process channel-path status change 473 * @crw0: channel report-word to handler 474 * @crw1: second channel-report word (always NULL) 475 * @overflow: crw overflow indication 476 * 477 * Handle channel-report-words indicating that the status of a channel-path 478 * has changed. 479 */ 480static void chp_process_crw(struct crw *crw0, struct crw *crw1, 481 int overflow) 482{ 483 struct chp_id chpid; 484 485 if (overflow) { 486 css_schedule_eval_all(); 487 return; 488 } 489 CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, " 490 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", 491 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc, 492 crw0->erc, crw0->rsid); 493 /* 494 * Check for solicited machine checks. These are 495 * created by reset channel path and need not be 496 * handled here. 497 */ 498 if (crw0->slct) { 499 CIO_CRW_EVENT(2, "solicited machine check for " 500 "channel path %02X\n", crw0->rsid); 501 return; 502 } 503 chp_id_init(&chpid); 504 chpid.id = crw0->rsid; 505 switch (crw0->erc) { 506 case CRW_ERC_IPARM: /* Path has come. */ 507 if (!chp_is_registered(chpid)) 508 chp_new(chpid); 509 chsc_chp_online(chpid); 510 break; 511 case CRW_ERC_PERRI: /* Path has gone. */ 512 case CRW_ERC_PERRN: 513 chsc_chp_offline(chpid); 514 break; 515 default: 516 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n", 517 crw0->erc); 518 } 519} 520 521int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link) 522{ 523 int i; 524 int mask; 525 526 for (i = 0; i < 8; i++) { 527 mask = 0x80 >> i; 528 if (!(ssd->path_mask & mask)) 529 continue; 530 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid)) 531 continue; 532 if ((ssd->fla_valid_mask & mask) && 533 ((ssd->fla[i] & link->fla_mask) != link->fla)) 534 continue; 535 return mask; 536 } 537 return 0; 538} 539EXPORT_SYMBOL_GPL(chp_ssd_get_mask); 540 541static inline int info_bit_num(struct chp_id id) 542{ 543 return id.id + id.cssid * (__MAX_CHPID + 1); 544} 545 546/* Force chp_info refresh on next call to info_validate(). */ 547static void info_expire(void) 548{ 549 mutex_lock(&info_lock); 550 chp_info_expires = jiffies - 1; 551 mutex_unlock(&info_lock); 552} 553 554/* Ensure that chp_info is up-to-date. */ 555static int info_update(void) 556{ 557 int rc; 558 559 mutex_lock(&info_lock); 560 rc = 0; 561 if (time_after(jiffies, chp_info_expires)) { 562 /* Data is too old, update. */ 563 rc = sclp_chp_read_info(&chp_info); 564 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ; 565 } 566 mutex_unlock(&info_lock); 567 568 return rc; 569} 570 571/** 572 * chp_info_get_status - retrieve configure status of a channel-path 573 * @chpid: channel-path ID 574 * 575 * On success, return 0 for standby, 1 for configured, 2 for reserved, 576 * 3 for not recognized. Return negative error code on error. 577 */ 578int chp_info_get_status(struct chp_id chpid) 579{ 580 int rc; 581 int bit; 582 583 rc = info_update(); 584 if (rc) 585 return rc; 586 587 bit = info_bit_num(chpid); 588 mutex_lock(&info_lock); 589 if (!chp_test_bit(chp_info.recognized, bit)) 590 rc = CHP_STATUS_NOT_RECOGNIZED; 591 else if (chp_test_bit(chp_info.configured, bit)) 592 rc = CHP_STATUS_CONFIGURED; 593 else if (chp_test_bit(chp_info.standby, bit)) 594 rc = CHP_STATUS_STANDBY; 595 else 596 rc = CHP_STATUS_RESERVED; 597 mutex_unlock(&info_lock); 598 599 return rc; 600} 601 602/* Return configure task for chpid. */ 603static enum cfg_task_t cfg_get_task(struct chp_id chpid) 604{ 605 return chp_cfg_task[chpid.cssid][chpid.id]; 606} 607 608/* Set configure task for chpid. */ 609static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg) 610{ 611 chp_cfg_task[chpid.cssid][chpid.id] = cfg; 612} 613 614/* Perform one configure/deconfigure request. Reschedule work function until 615 * last request. */ 616static void cfg_func(struct work_struct *work) 617{ 618 struct chp_id chpid; 619 enum cfg_task_t t; 620 int rc; 621 622 mutex_lock(&cfg_lock); 623 t = cfg_none; 624 chp_id_for_each(&chpid) { 625 t = cfg_get_task(chpid); 626 if (t != cfg_none) { 627 cfg_set_task(chpid, cfg_none); 628 break; 629 } 630 } 631 mutex_unlock(&cfg_lock); 632 633 switch (t) { 634 case cfg_configure: 635 rc = sclp_chp_configure(chpid); 636 if (rc) 637 CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)=" 638 "%d\n", chpid.cssid, chpid.id, rc); 639 else { 640 info_expire(); 641 chsc_chp_online(chpid); 642 } 643 break; 644 case cfg_deconfigure: 645 rc = sclp_chp_deconfigure(chpid); 646 if (rc) 647 CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)=" 648 "%d\n", chpid.cssid, chpid.id, rc); 649 else { 650 info_expire(); 651 chsc_chp_offline(chpid); 652 } 653 break; 654 case cfg_none: 655 /* Get updated information after last change. */ 656 info_update(); 657 mutex_lock(&cfg_lock); 658 cfg_busy = 0; 659 mutex_unlock(&cfg_lock); 660 wake_up_interruptible(&cfg_wait_queue); 661 return; 662 } 663 queue_work(chp_wq, &cfg_work); 664} 665 666/** 667 * chp_cfg_schedule - schedule chpid configuration request 668 * @chpid - channel-path ID 669 * @configure - Non-zero for configure, zero for deconfigure 670 * 671 * Schedule a channel-path configuration/deconfiguration request. 672 */ 673void chp_cfg_schedule(struct chp_id chpid, int configure) 674{ 675 CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id, 676 configure); 677 mutex_lock(&cfg_lock); 678 cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); 679 cfg_busy = 1; 680 mutex_unlock(&cfg_lock); 681 queue_work(chp_wq, &cfg_work); 682} 683 684/** 685 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request 686 * @chpid - channel-path ID 687 * 688 * Cancel an active channel-path deconfiguration request if it has not yet 689 * been performed. 690 */ 691void chp_cfg_cancel_deconfigure(struct chp_id chpid) 692{ 693 CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id); 694 mutex_lock(&cfg_lock); 695 if (cfg_get_task(chpid) == cfg_deconfigure) 696 cfg_set_task(chpid, cfg_none); 697 mutex_unlock(&cfg_lock); 698} 699 700static int cfg_wait_idle(void) 701{ 702 if (wait_event_interruptible(cfg_wait_queue, !cfg_busy)) 703 return -ERESTARTSYS; 704 return 0; 705} 706 707static int __init chp_init(void) 708{ 709 struct chp_id chpid; 710 int ret; 711 712 ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw); 713 if (ret) 714 return ret; 715 chp_wq = create_singlethread_workqueue("cio_chp"); 716 if (!chp_wq) { 717 crw_unregister_handler(CRW_RSC_CPATH); 718 return -ENOMEM; 719 } 720 INIT_WORK(&cfg_work, cfg_func); 721 init_waitqueue_head(&cfg_wait_queue); 722 if (info_update()) 723 return 0; 724 /* Register available channel-paths. */ 725 chp_id_for_each(&chpid) { 726 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED) 727 chp_new(chpid); 728 } 729 730 return 0; 731} 732 733subsys_initcall(chp_init); 734