drivers/s390/cio/chp.c

   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
  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  47 /* Time after which channel-path status may be outdated.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 /* Return channel_path struct for given chpid. */
  58 static 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. */
  64 static 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. */
  71 int 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  */
  83 u8 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 }
  99 EXPORT_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  */
 108 int 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  */
 117 static 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  */
 138 static 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
 155 static 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
 164 static 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
 186 static 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
 209 static 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
 218 void 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
 224 int 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  */
 240 static 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
 251 static 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
 275 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 276
 277 static 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
 291 static int cfg_wait_idle(void);
 292
 293 static 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
 312 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 313
 314 static 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
 324 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 325
 326 static 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
 338 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 339
 340 static 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
 352 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 353
 354 static 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
 363 static struct attribute_group chp_attr_group = {
 364         .attrs = chp_attrs,
 365 };
 366
 367 static 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  */
 382 int 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;
 443 out_free:
 444         kfree(chp);
 445 out:
 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  */
 456 void *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  */
 480 static 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
 521 int 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 }
 539 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 540
 541 static 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(). */
 547 static 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. */
 555 static 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  */
 578 int 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. */
 603 static 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. */
 609 static 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. */
 616 static 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  */
 673 void 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  */
 691 void 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
 700 static int cfg_wait_idle(void)
 701 {
 702         if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
 703                 return -ERESTARTSYS;
 704         return 0;
 705 }
 706
 707 static 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
 733 subsys_initcall(chp_init);