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 <asm/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struct sclp_chp_info chp_info; 43 static DEFINE_MUTEX(info_lock); 44 45 /* Time after which channel-path status may be outdated.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 css[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 unsigned int size; 144 145 chp = to_channelpath(container_of(kobj, struct device, kobj)); 146 if (!chp->cmg_chars) 147 return 0; 148 149 size = sizeof(struct cmg_chars); 150 151 if (off > size) 152 return 0; 153 if (off + count > size) 154 count = size - off; 155 memcpy(buf, chp->cmg_chars + off, count); 156 return count; 157 } 158 159 static struct bin_attribute chp_measurement_chars_attr = { 160 .attr = { 161 .name = "measurement_chars", 162 .mode = S_IRUSR, 163 }, 164 .size = sizeof(struct cmg_chars), 165 .read = chp_measurement_chars_read, 166 }; 167 168 static void chp_measurement_copy_block(struct cmg_entry *buf, 169 struct channel_subsystem *css, 170 struct chp_id chpid) 171 { 172 void *area; 173 struct cmg_entry *entry, reference_buf; 174 int idx; 175 176 if (chpid.id < 128) { 177 area = css->cub_addr1; 178 idx = chpid.id; 179 } else { 180 area = css->cub_addr2; 181 idx = chpid.id - 128; 182 } 183 entry = area + (idx * sizeof(struct cmg_entry)); 184 do { 185 memcpy(buf, entry, sizeof(*entry)); 186 memcpy(&reference_buf, entry, sizeof(*entry)); 187 } while (reference_buf.values[0] != buf->values[0]); 188 } 189 190 static ssize_t chp_measurement_read(struct kobject *kobj, 191 struct bin_attribute *bin_attr, 192 char *buf, loff_t off, size_t count) 193 { 194 struct channel_path *chp; 195 struct channel_subsystem *css; 196 unsigned int size; 197 198 chp = to_channelpath(container_of(kobj, struct device, kobj)); 199 css = to_css(chp->dev.parent); 200 201 size = sizeof(struct cmg_entry); 202 203 /* Only allow single reads. */ 204 if (off || count < size) 205 return 0; 206 chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid); 207 count = size; 208 return count; 209 } 210 211 static struct bin_attribute chp_measurement_attr = { 212 .attr = { 213 .name = "measurement", 214 .mode = S_IRUSR, 215 }, 216 .size = sizeof(struct cmg_entry), 217 .read = chp_measurement_read, 218 }; 219 220 void chp_remove_cmg_attr(struct channel_path *chp) 221 { 222 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 223 device_remove_bin_file(&chp->dev, &chp_measurement_attr); 224 } 225 226 int chp_add_cmg_attr(struct channel_path *chp) 227 { 228 int ret; 229 230 ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr); 231 if (ret) 232 return ret; 233 ret = device_create_bin_file(&chp->dev, &chp_measurement_attr); 234 if (ret) 235 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); 236 return ret; 237 } 238 239 /* 240 * Files for the channel path entries. 241 */ 242 static ssize_t chp_status_show(struct device *dev, 243 struct device_attribute *attr, char *buf) 244 { 245 struct channel_path *chp = container_of(dev, struct channel_path, dev); 246 247 if (!chp) 248 return 0; 249 return (chp_get_status(chp->chpid) ? sprintf(buf, "online\n") : 250 sprintf(buf, "offline\n")); 251 } 252 253 static ssize_t chp_status_write(struct device *dev, 254 struct device_attribute *attr, 255 const char *buf, size_t count) 256 { 257 struct channel_path *cp = container_of(dev, struct channel_path, dev); 258 char cmd[10]; 259 int num_args; 260 int error; 261 262 num_args = sscanf(buf, "%5s", cmd); 263 if (!num_args) 264 return count; 265 266 if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) 267 error = s390_vary_chpid(cp->chpid, 1); 268 else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) 269 error = s390_vary_chpid(cp->chpid, 0); 270 else 271 error = -EINVAL; 272 273 return error < 0 ? error : count; 274 275 } 276 277 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write); 278 279 static ssize_t chp_configure_show(struct device *dev, 280 struct device_attribute *attr, char *buf) 281 { 282 struct channel_path *cp; 283 int status; 284 285 cp = container_of(dev, struct channel_path, dev); 286 status = chp_info_get_status(cp->chpid); 287 if (status < 0) 288 return status; 289 290 return snprintf(buf, PAGE_SIZE, "%d\n", status); 291 } 292 293 static int cfg_wait_idle(void); 294 295 static ssize_t chp_configure_write(struct device *dev, 296 struct device_attribute *attr, 297 const char *buf, size_t count) 298 { 299 struct channel_path *cp; 300 int val; 301 char delim; 302 303 if (sscanf(buf, "%d %c", &val, &delim) != 1) 304 return -EINVAL; 305 if (val != 0 && val != 1) 306 return -EINVAL; 307 cp = container_of(dev, struct channel_path, dev); 308 chp_cfg_schedule(cp->chpid, val); 309 cfg_wait_idle(); 310 311 return count; 312 } 313 314 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write); 315 316 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr, 317 char *buf) 318 { 319 struct channel_path *chp = container_of(dev, struct channel_path, dev); 320 321 if (!chp) 322 return 0; 323 return sprintf(buf, "%x\n", chp->desc.desc); 324 } 325 326 static DEVICE_ATTR(type, 0444, chp_type_show, NULL); 327 328 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr, 329 char *buf) 330 { 331 struct channel_path *chp = to_channelpath(dev); 332 333 if (!chp) 334 return 0; 335 if (chp->cmg == -1) /* channel measurements not available */ 336 return sprintf(buf, "unknown\n"); 337 return sprintf(buf, "%x\n", chp->cmg); 338 } 339 340 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL); 341 342 static ssize_t chp_shared_show(struct device *dev, 343 struct device_attribute *attr, char *buf) 344 { 345 struct channel_path *chp = to_channelpath(dev); 346 347 if (!chp) 348 return 0; 349 if (chp->shared == -1) /* channel measurements not available */ 350 return sprintf(buf, "unknown\n"); 351 return sprintf(buf, "%x\n", chp->shared); 352 } 353 354 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL); 355 356 static struct attribute * chp_attrs[] = { 357 &dev_attr_status.attr, 358 &dev_attr_configure.attr, 359 &dev_attr_type.attr, 360 &dev_attr_cmg.attr, 361 &dev_attr_shared.attr, 362 NULL, 363 }; 364 365 static struct attribute_group chp_attr_group = { 366 .attrs = chp_attrs, 367 }; 368 369 static void chp_release(struct device *dev) 370 { 371 struct channel_path *cp; 372 373 cp = container_of(dev, struct channel_path, dev); 374 kfree(cp); 375 } 376 377 /** 378 * chp_new - register a new channel-path 379 * @chpid - channel-path ID 380 * 381 * Create and register data structure representing new channel-path. Return 382 * zero on success, non-zero otherwise. 383 */ 384 int chp_new(struct chp_id chpid) 385 { 386 struct channel_path *chp; 387 int ret; 388 389 if (chp_is_registered(chpid)) 390 return 0; 391 chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); 392 if (!chp) 393 return -ENOMEM; 394 395 /* fill in status, etc. */ 396 chp->chpid = chpid; 397 chp->state = 1; 398 chp->dev.parent = &css[chpid.cssid]->device; 399 chp->dev.release = chp_release; 400 snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp%x.%02x", chpid.cssid, 401 chpid.id); 402 403 /* Obtain channel path description and fill it in. */ 404 ret = chsc_determine_channel_path_description(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_characteristics_avail && css_chsc_characteristics.scmc 413 && css_chsc_characteristics.secm) { 414 ret = chsc_get_channel_measurement_chars(chp); 415 if (ret) 416 goto out_free; 417 } else { 418 chp->cmg = -1; 419 } 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 goto out_free; 427 } 428 ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group); 429 if (ret) { 430 device_unregister(&chp->dev); 431 goto out_free; 432 } 433 mutex_lock(&css[chpid.cssid]->mutex); 434 if (css[chpid.cssid]->cm_enabled) { 435 ret = chp_add_cmg_attr(chp); 436 if (ret) { 437 sysfs_remove_group(&chp->dev.kobj, &chp_attr_group); 438 device_unregister(&chp->dev); 439 mutex_unlock(&css[chpid.cssid]->mutex); 440 goto out_free; 441 } 442 } 443 css[chpid.cssid]->chps[chpid.id] = chp; 444 mutex_unlock(&css[chpid.cssid]->mutex); 445 return ret; 446 out_free: 447 kfree(chp); 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 memcpy(desc, &chp->desc, sizeof(struct channel_path_desc)); 470 return desc; 471 } 472 473 /** 474 * chp_process_crw - process channel-path status change 475 * @id: channel-path ID number 476 * @status: non-zero if channel-path has become available, zero otherwise 477 * 478 * Handle channel-report-words indicating that the status of a channel-path 479 * has changed. 480 */ 481 void chp_process_crw(int id, int status) 482 { 483 struct chp_id chpid; 484 485 chp_id_init(&chpid); 486 chpid.id = id; 487 if (status) { 488 if (!chp_is_registered(chpid)) 489 chp_new(chpid); 490 chsc_chp_online(chpid); 491 } else 492 chsc_chp_offline(chpid); 493 } 494 495 static inline int info_bit_num(struct chp_id id) 496 { 497 return id.id + id.cssid * (__MAX_CHPID + 1); 498 } 499 500 /* Force chp_info refresh on next call to info_validate(). */ 501 static void info_expire(void) 502 { 503 mutex_lock(&info_lock); 504 chp_info_expires = jiffies - 1; 505 mutex_unlock(&info_lock); 506 } 507 508 /* Ensure that chp_info is up-to-date. */ 509 static int info_update(void) 510 { 511 int rc; 512 513 mutex_lock(&info_lock); 514 rc = 0; 515 if (time_after(jiffies, chp_info_expires)) { 516 /* Data is too old, update. */ 517 rc = sclp_chp_read_info(&chp_info); 518 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ; 519 } 520 mutex_unlock(&info_lock); 521 522 return rc; 523 } 524 525 /** 526 * chp_info_get_status - retrieve configure status of a channel-path 527 * @chpid: channel-path ID 528 * 529 * On success, return 0 for standby, 1 for configured, 2 for reserved, 530 * 3 for not recognized. Return negative error code on error. 531 */ 532 int chp_info_get_status(struct chp_id chpid) 533 { 534 int rc; 535 int bit; 536 537 rc = info_update(); 538 if (rc) 539 return rc; 540 541 bit = info_bit_num(chpid); 542 mutex_lock(&info_lock); 543 if (!chp_test_bit(chp_info.recognized, bit)) 544 rc = CHP_STATUS_NOT_RECOGNIZED; 545 else if (chp_test_bit(chp_info.configured, bit)) 546 rc = CHP_STATUS_CONFIGURED; 547 else if (chp_test_bit(chp_info.standby, bit)) 548 rc = CHP_STATUS_STANDBY; 549 else 550 rc = CHP_STATUS_RESERVED; 551 mutex_unlock(&info_lock); 552 553 return rc; 554 } 555 556 /* Return configure task for chpid. */ 557 static enum cfg_task_t cfg_get_task(struct chp_id chpid) 558 { 559 return chp_cfg_task[chpid.cssid][chpid.id]; 560 } 561 562 /* Set configure task for chpid. */ 563 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg) 564 { 565 chp_cfg_task[chpid.cssid][chpid.id] = cfg; 566 } 567 568 /* Perform one configure/deconfigure request. Reschedule work function until 569 * last request. */ 570 static void cfg_func(struct work_struct *work) 571 { 572 struct chp_id chpid; 573 enum cfg_task_t t; 574 575 mutex_lock(&cfg_lock); 576 t = cfg_none; 577 chp_id_for_each(&chpid) { 578 t = cfg_get_task(chpid); 579 if (t != cfg_none) { 580 cfg_set_task(chpid, cfg_none); 581 break; 582 } 583 } 584 mutex_unlock(&cfg_lock); 585 586 switch (t) { 587 case cfg_configure: 588 sclp_chp_configure(chpid); 589 info_expire(); 590 chsc_chp_online(chpid); 591 break; 592 case cfg_deconfigure: 593 sclp_chp_deconfigure(chpid); 594 info_expire(); 595 chsc_chp_offline(chpid); 596 break; 597 case cfg_none: 598 /* Get updated information after last change. */ 599 info_update(); 600 mutex_lock(&cfg_lock); 601 cfg_busy = 0; 602 mutex_unlock(&cfg_lock); 603 wake_up_interruptible(&cfg_wait_queue); 604 return; 605 } 606 queue_work(chp_wq, &cfg_work); 607 } 608 609 /** 610 * chp_cfg_schedule - schedule chpid configuration request 611 * @chpid - channel-path ID 612 * @configure - Non-zero for configure, zero for deconfigure 613 * 614 * Schedule a channel-path configuration/deconfiguration request. 615 */ 616 void chp_cfg_schedule(struct chp_id chpid, int configure) 617 { 618 CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id, 619 configure); 620 mutex_lock(&cfg_lock); 621 cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); 622 cfg_busy = 1; 623 mutex_unlock(&cfg_lock); 624 queue_work(chp_wq, &cfg_work); 625 } 626 627 /** 628 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request 629 * @chpid - channel-path ID 630 * 631 * Cancel an active channel-path deconfiguration request if it has not yet 632 * been performed. 633 */ 634 void chp_cfg_cancel_deconfigure(struct chp_id chpid) 635 { 636 CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id); 637 mutex_lock(&cfg_lock); 638 if (cfg_get_task(chpid) == cfg_deconfigure) 639 cfg_set_task(chpid, cfg_none); 640 mutex_unlock(&cfg_lock); 641 } 642 643 static int cfg_wait_idle(void) 644 { 645 if (wait_event_interruptible(cfg_wait_queue, !cfg_busy)) 646 return -ERESTARTSYS; 647 return 0; 648 } 649 650 static int __init chp_init(void) 651 { 652 struct chp_id chpid; 653 654 chp_wq = create_singlethread_workqueue("cio_chp"); 655 if (!chp_wq) 656 return -ENOMEM; 657 INIT_WORK(&cfg_work, cfg_func); 658 init_waitqueue_head(&cfg_wait_queue); 659 if (info_update()) 660 return 0; 661 /* Register available channel-paths. */ 662 chp_id_for_each(&chpid) { 663 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED) 664 chp_new(chpid); 665 } 666 667 return 0; 668 } 669 670 subsys_initcall(chp_init); 671