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struct sclp_chp_info chp_info; 43 static DEFINE_MUTEX(info_lock); 44 45 /* Time after which channel-path status may be outdated.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