drivers/s390/cio/chp.c

   1 /*
   2  *    Copyright IBM Corp. 1999, 2010
   3  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
   4  *               Arnd Bergmann (arndb@de.ibm.com)
   5  *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   6  */
   7
   8 #include <linux/bug.h>
   9 #include <linux/workqueue.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/export.h>
  12 #include <linux/sched.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  47 /* Time after which channel-path status may be outdated.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 static struct attribute_group chp_attr_group = {
 364         .attrs = chp_attrs,
 365 };
 366 static const struct attribute_group *chp_attr_groups[] = {
 367         &chp_attr_group,
 368         NULL,
 369 };
 370
 371 static void chp_release(struct device *dev)
 372 {
 373         struct channel_path *cp;
 374
 375         cp = to_channelpath(dev);
 376         kfree(cp);
 377 }
 378
 379 /**
 380  * chp_update_desc - update channel-path description
 381  * @chp - channel-path
 382  *
 383  * Update the channel-path description of the specified channel-path.
 384  * Return zero on success, non-zero otherwise.
 385  */
 386 int chp_update_desc(struct channel_path *chp)
 387 {
 388         int rc;
 389
 390         rc = chsc_determine_base_channel_path_desc(chp->chpid, &chp->desc);
 391         if (rc)
 392                 return rc;
 393
 394         rc = chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
 395
 396         return rc;
 397 }
 398
 399 /**
 400  * chp_new - register a new channel-path
 401  * @chpid - channel-path ID
 402  *
 403  * Create and register data structure representing new channel-path. Return
 404  * zero on success, non-zero otherwise.
 405  */
 406 int chp_new(struct chp_id chpid)
 407 {
 408         struct channel_path *chp;
 409         int ret;
 410
 411         if (chp_is_registered(chpid))
 412                 return 0;
 413         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 414         if (!chp)
 415                 return -ENOMEM;
 416
 417         /* fill in status, etc. */
 418         chp->chpid = chpid;
 419         chp->state = 1;
 420         chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
 421         chp->dev.groups = chp_attr_groups;
 422         chp->dev.release = chp_release;
 423         mutex_init(&chp->lock);
 424
 425         /* Obtain channel path description and fill it in. */
 426         ret = chp_update_desc(chp);
 427         if (ret)
 428                 goto out_free;
 429         if ((chp->desc.flags & 0x80) == 0) {
 430                 ret = -ENODEV;
 431                 goto out_free;
 432         }
 433         /* Get channel-measurement characteristics. */
 434         if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) {
 435                 ret = chsc_get_channel_measurement_chars(chp);
 436                 if (ret)
 437                         goto out_free;
 438         } else {
 439                 chp->cmg = -1;
 440         }
 441         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 442
 443         /* make it known to the system */
 444         ret = device_register(&chp->dev);
 445         if (ret) {
 446                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 447                               chpid.cssid, chpid.id, ret);
 448                 put_device(&chp->dev);
 449                 goto out;
 450         }
 451         mutex_lock(&channel_subsystems[chpid.cssid]->mutex);
 452         if (channel_subsystems[chpid.cssid]->cm_enabled) {
 453                 ret = chp_add_cmg_attr(chp);
 454                 if (ret) {
 455                         device_unregister(&chp->dev);
 456                         mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
 457                         goto out;
 458                 }
 459         }
 460         channel_subsystems[chpid.cssid]->chps[chpid.id] = chp;
 461         mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
 462         goto out;
 463 out_free:
 464         kfree(chp);
 465 out:
 466         return ret;
 467 }
 468
 469 /**
 470  * chp_get_chp_desc - return newly allocated channel-path description
 471  * @chpid: channel-path ID
 472  *
 473  * On success return a newly allocated copy of the channel-path description
 474  * data associated with the given channel-path ID. Return %NULL on error.
 475  */
 476 void *chp_get_chp_desc(struct chp_id chpid)
 477 {
 478         struct channel_path *chp;
 479         struct channel_path_desc *desc;
 480
 481         chp = chpid_to_chp(chpid);
 482         if (!chp)
 483                 return NULL;
 484         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
 485         if (!desc)
 486                 return NULL;
 487
 488         mutex_lock(&chp->lock);
 489         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
 490         mutex_unlock(&chp->lock);
 491         return desc;
 492 }
 493
 494 /**
 495  * chp_process_crw - process channel-path status change
 496  * @crw0: channel report-word to handler
 497  * @crw1: second channel-report word (always NULL)
 498  * @overflow: crw overflow indication
 499  *
 500  * Handle channel-report-words indicating that the status of a channel-path
 501  * has changed.
 502  */
 503 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 504                             int overflow)
 505 {
 506         struct chp_id chpid;
 507
 508         if (overflow) {
 509                 css_schedule_eval_all();
 510                 return;
 511         }
 512         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 513                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 514                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 515                       crw0->erc, crw0->rsid);
 516         /*
 517          * Check for solicited machine checks. These are
 518          * created by reset channel path and need not be
 519          * handled here.
 520          */
 521         if (crw0->slct) {
 522                 CIO_CRW_EVENT(2, "solicited machine check for "
 523                               "channel path %02X\n", crw0->rsid);
 524                 return;
 525         }
 526         chp_id_init(&chpid);
 527         chpid.id = crw0->rsid;
 528         switch (crw0->erc) {
 529         case CRW_ERC_IPARM: /* Path has come. */
 530                 if (!chp_is_registered(chpid))
 531                         chp_new(chpid);
 532                 chsc_chp_online(chpid);
 533                 break;
 534         case CRW_ERC_PERRI: /* Path has gone. */
 535         case CRW_ERC_PERRN:
 536                 chsc_chp_offline(chpid);
 537                 break;
 538         default:
 539                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 540                               crw0->erc);
 541         }
 542 }
 543
 544 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 545 {
 546         int i;
 547         int mask;
 548
 549         for (i = 0; i < 8; i++) {
 550                 mask = 0x80 >> i;
 551                 if (!(ssd->path_mask & mask))
 552                         continue;
 553                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 554                         continue;
 555                 if ((ssd->fla_valid_mask & mask) &&
 556                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 557                         continue;
 558                 return mask;
 559         }
 560         return 0;
 561 }
 562 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 563
 564 static inline int info_bit_num(struct chp_id id)
 565 {
 566         return id.id + id.cssid * (__MAX_CHPID + 1);
 567 }
 568
 569 /* Force chp_info refresh on next call to info_validate(). */
 570 static void info_expire(void)
 571 {
 572         mutex_lock(&info_lock);
 573         chp_info_expires = jiffies - 1;
 574         mutex_unlock(&info_lock);
 575 }
 576
 577 /* Ensure that chp_info is up-to-date. */
 578 static int info_update(void)
 579 {
 580         int rc;
 581
 582         mutex_lock(&info_lock);
 583         rc = 0;
 584         if (time_after(jiffies, chp_info_expires)) {
 585                 /* Data is too old, update. */
 586                 rc = sclp_chp_read_info(&chp_info);
 587                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 588         }
 589         mutex_unlock(&info_lock);
 590
 591         return rc;
 592 }
 593
 594 /**
 595  * chp_info_get_status - retrieve configure status of a channel-path
 596  * @chpid: channel-path ID
 597  *
 598  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 599  * 3 for not recognized. Return negative error code on error.
 600  */
 601 int chp_info_get_status(struct chp_id chpid)
 602 {
 603         int rc;
 604         int bit;
 605
 606         rc = info_update();
 607         if (rc)
 608                 return rc;
 609
 610         bit = info_bit_num(chpid);
 611         mutex_lock(&info_lock);
 612         if (!chp_test_bit(chp_info.recognized, bit))
 613                 rc = CHP_STATUS_NOT_RECOGNIZED;
 614         else if (chp_test_bit(chp_info.configured, bit))
 615                 rc = CHP_STATUS_CONFIGURED;
 616         else if (chp_test_bit(chp_info.standby, bit))
 617                 rc = CHP_STATUS_STANDBY;
 618         else
 619                 rc = CHP_STATUS_RESERVED;
 620         mutex_unlock(&info_lock);
 621
 622         return rc;
 623 }
 624
 625 /* Return configure task for chpid. */
 626 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 627 {
 628         return chp_cfg_task[chpid.cssid][chpid.id];
 629 }
 630
 631 /* Set configure task for chpid. */
 632 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 633 {
 634         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 635 }
 636
 637 /* Perform one configure/deconfigure request. Reschedule work function until
 638  * last request. */
 639 static void cfg_func(struct work_struct *work)
 640 {
 641         struct chp_id chpid;
 642         enum cfg_task_t t;
 643         int rc;
 644
 645         mutex_lock(&cfg_lock);
 646         t = cfg_none;
 647         chp_id_for_each(&chpid) {
 648                 t = cfg_get_task(chpid);
 649                 if (t != cfg_none) {
 650                         cfg_set_task(chpid, cfg_none);
 651                         break;
 652                 }
 653         }
 654         mutex_unlock(&cfg_lock);
 655
 656         switch (t) {
 657         case cfg_configure:
 658                 rc = sclp_chp_configure(chpid);
 659                 if (rc)
 660                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 661                                       "%d\n", chpid.cssid, chpid.id, rc);
 662                 else {
 663                         info_expire();
 664                         chsc_chp_online(chpid);
 665                 }
 666                 break;
 667         case cfg_deconfigure:
 668                 rc = sclp_chp_deconfigure(chpid);
 669                 if (rc)
 670                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 671                                       "%d\n", chpid.cssid, chpid.id, rc);
 672                 else {
 673                         info_expire();
 674                         chsc_chp_offline(chpid);
 675                 }
 676                 break;
 677         case cfg_none:
 678                 /* Get updated information after last change. */
 679                 info_update();
 680                 mutex_lock(&cfg_lock);
 681                 cfg_busy = 0;
 682                 mutex_unlock(&cfg_lock);
 683                 wake_up_interruptible(&cfg_wait_queue);
 684                 return;
 685         }
 686         queue_work(chp_wq, &cfg_work);
 687 }
 688
 689 /**
 690  * chp_cfg_schedule - schedule chpid configuration request
 691  * @chpid - channel-path ID
 692  * @configure - Non-zero for configure, zero for deconfigure
 693  *
 694  * Schedule a channel-path configuration/deconfiguration request.
 695  */
 696 void chp_cfg_schedule(struct chp_id chpid, int configure)
 697 {
 698         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 699                       configure);
 700         mutex_lock(&cfg_lock);
 701         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 702         cfg_busy = 1;
 703         mutex_unlock(&cfg_lock);
 704         queue_work(chp_wq, &cfg_work);
 705 }
 706
 707 /**
 708  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 709  * @chpid - channel-path ID
 710  *
 711  * Cancel an active channel-path deconfiguration request if it has not yet
 712  * been performed.
 713  */
 714 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 715 {
 716         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 717         mutex_lock(&cfg_lock);
 718         if (cfg_get_task(chpid) == cfg_deconfigure)
 719                 cfg_set_task(chpid, cfg_none);
 720         mutex_unlock(&cfg_lock);
 721 }
 722
 723 static int cfg_wait_idle(void)
 724 {
 725         if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
 726                 return -ERESTARTSYS;
 727         return 0;
 728 }
 729
 730 static int __init chp_init(void)
 731 {
 732         struct chp_id chpid;
 733         int ret;
 734
 735         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 736         if (ret)
 737                 return ret;
 738         chp_wq = create_singlethread_workqueue("cio_chp");
 739         if (!chp_wq) {
 740                 crw_unregister_handler(CRW_RSC_CPATH);
 741                 return -ENOMEM;
 742         }
 743         INIT_WORK(&cfg_work, cfg_func);
 744         init_waitqueue_head(&cfg_wait_queue);
 745         if (info_update())
 746                 return 0;
 747         /* Register available channel-paths. */
 748         chp_id_for_each(&chpid) {
 749                 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
 750                         chp_new(chpid);
 751         }
 752
 753         return 0;
 754 }
 755
 756 subsys_initcall(chp_init);