drivers/s390/cio/chp.c

   1 /*
   2  *  drivers/s390/cio/chp.c
   3  *
   4  *    Copyright IBM Corp. 1999,2010
   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/export.h>
  14 #include <linux/sched.h>
  15 #include <linux/init.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/wait.h>
  18 #include <linux/mutex.h>
  19 #include <linux/errno.h>
  20 #include <linux/slab.h>
  21 #include <asm/chpid.h>
  22 #include <asm/sclp.h>
  23 #include <asm/crw.h>
  24
  25 #include "cio.h"
  26 #include "css.h"
  27 #include "ioasm.h"
  28 #include "cio_debug.h"
  29 #include "chp.h"
  30
  31 #define to_channelpath(device) container_of(device, struct channel_path, dev)
  32 #define CHP_INFO_UPDATE_INTERVAL        1*HZ
  33
  34 enum cfg_task_t {
  35         cfg_none,
  36         cfg_configure,
  37         cfg_deconfigure
  38 };
  39
  40 /* Map for pending configure tasks. */
  41 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
  42 static DEFINE_MUTEX(cfg_lock);
  43 static int cfg_busy;
  44
  45 /* Map for channel-path status. */
  46 static struct sclp_chp_info chp_info;
  47 static DEFINE_MUTEX(info_lock);
  48
  49 /* Time after which channel-path status may be outdated. */
  50 static unsigned long chp_info_expires;
  51
  52 /* Workqueue to perform pending configure tasks. */
  53 static struct workqueue_struct *chp_wq;
  54 static struct work_struct cfg_work;
  55
  56 /* Wait queue for configure completion events. */
  57 static wait_queue_head_t cfg_wait_queue;
  58
  59 /* Set vary state for given chpid. */
  60 static void set_chp_logically_online(struct chp_id chpid, int onoff)
  61 {
  62         chpid_to_chp(chpid)->state = onoff;
  63 }
  64
  65 /* On success return 0 if channel-path is varied offline, 1 if it is varied
  66  * online. Return -ENODEV if channel-path is not registered. */
  67 int chp_get_status(struct chp_id chpid)
  68 {
  69         return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
  70 }
  71
  72 /**
  73  * chp_get_sch_opm - return opm for subchannel
  74  * @sch: subchannel
  75  *
  76  * Calculate and return the operational path mask (opm) based on the chpids
  77  * used by the subchannel and the status of the associated channel-paths.
  78  */
  79 u8 chp_get_sch_opm(struct subchannel *sch)
  80 {
  81         struct chp_id chpid;
  82         int opm;
  83         int i;
  84
  85         opm = 0;
  86         chp_id_init(&chpid);
  87         for (i = 0; i < 8; i++) {
  88                 opm <<= 1;
  89                 chpid.id = sch->schib.pmcw.chpid[i];
  90                 if (chp_get_status(chpid) != 0)
  91                         opm |= 1;
  92         }
  93         return opm;
  94 }
  95 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
  96
  97 /**
  98  * chp_is_registered - check if a channel-path is registered
  99  * @chpid: channel-path ID
 100  *
 101  * Return non-zero if a channel-path with the given chpid is registered,
 102  * zero otherwise.
 103  */
 104 int chp_is_registered(struct chp_id chpid)
 105 {
 106         return chpid_to_chp(chpid) != NULL;
 107 }
 108
 109 /*
 110  * Function: s390_vary_chpid
 111  * Varies the specified chpid online or offline
 112  */
 113 static int s390_vary_chpid(struct chp_id chpid, int on)
 114 {
 115         char dbf_text[15];
 116         int status;
 117
 118         sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
 119                 chpid.id);
 120         CIO_TRACE_EVENT(2, dbf_text);
 121
 122         status = chp_get_status(chpid);
 123         if (!on && !status)
 124                 return 0;
 125
 126         set_chp_logically_online(chpid, on);
 127         chsc_chp_vary(chpid, on);
 128         return 0;
 129 }
 130
 131 /*
 132  * Channel measurement related functions
 133  */
 134 static ssize_t chp_measurement_chars_read(struct file *filp,
 135                                           struct kobject *kobj,
 136                                           struct bin_attribute *bin_attr,
 137                                           char *buf, loff_t off, size_t count)
 138 {
 139         struct channel_path *chp;
 140         struct device *device;
 141
 142         device = container_of(kobj, struct device, kobj);
 143         chp = to_channelpath(device);
 144         if (!chp->cmg_chars)
 145                 return 0;
 146
 147         return memory_read_from_buffer(buf, count, &off,
 148                                 chp->cmg_chars, sizeof(struct cmg_chars));
 149 }
 150
 151 static struct bin_attribute chp_measurement_chars_attr = {
 152         .attr = {
 153                 .name = "measurement_chars",
 154                 .mode = S_IRUSR,
 155         },
 156         .size = sizeof(struct cmg_chars),
 157         .read = chp_measurement_chars_read,
 158 };
 159
 160 static void chp_measurement_copy_block(struct cmg_entry *buf,
 161                                        struct channel_subsystem *css,
 162                                        struct chp_id chpid)
 163 {
 164         void *area;
 165         struct cmg_entry *entry, reference_buf;
 166         int idx;
 167
 168         if (chpid.id < 128) {
 169                 area = css->cub_addr1;
 170                 idx = chpid.id;
 171         } else {
 172                 area = css->cub_addr2;
 173                 idx = chpid.id - 128;
 174         }
 175         entry = area + (idx * sizeof(struct cmg_entry));
 176         do {
 177                 memcpy(buf, entry, sizeof(*entry));
 178                 memcpy(&reference_buf, entry, sizeof(*entry));
 179         } while (reference_buf.values[0] != buf->values[0]);
 180 }
 181
 182 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
 183                                     struct bin_attribute *bin_attr,
 184                                     char *buf, loff_t off, size_t count)
 185 {
 186         struct channel_path *chp;
 187         struct channel_subsystem *css;
 188         struct device *device;
 189         unsigned int size;
 190
 191         device = container_of(kobj, struct device, kobj);
 192         chp = to_channelpath(device);
 193         css = to_css(chp->dev.parent);
 194
 195         size = sizeof(struct cmg_entry);
 196
 197         /* Only allow single reads. */
 198         if (off || count < size)
 199                 return 0;
 200         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
 201         count = size;
 202         return count;
 203 }
 204
 205 static struct bin_attribute chp_measurement_attr = {
 206         .attr = {
 207                 .name = "measurement",
 208                 .mode = S_IRUSR,
 209         },
 210         .size = sizeof(struct cmg_entry),
 211         .read = chp_measurement_read,
 212 };
 213
 214 void chp_remove_cmg_attr(struct channel_path *chp)
 215 {
 216         device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 217         device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 218 }
 219
 220 int chp_add_cmg_attr(struct channel_path *chp)
 221 {
 222         int ret;
 223
 224         ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 225         if (ret)
 226                 return ret;
 227         ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 228         if (ret)
 229                 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 230         return ret;
 231 }
 232
 233 /*
 234  * Files for the channel path entries.
 235  */
 236 static ssize_t chp_status_show(struct device *dev,
 237                                struct device_attribute *attr, char *buf)
 238 {
 239         struct channel_path *chp = to_channelpath(dev);
 240         int status;
 241
 242         mutex_lock(&chp->lock);
 243         status = chp->state;
 244         mutex_unlock(&chp->lock);
 245
 246         return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
 247 }
 248
 249 static ssize_t chp_status_write(struct device *dev,
 250                                 struct device_attribute *attr,
 251                                 const char *buf, size_t count)
 252 {
 253         struct channel_path *cp = to_channelpath(dev);
 254         char cmd[10];
 255         int num_args;
 256         int error;
 257
 258         num_args = sscanf(buf, "%5s", cmd);
 259         if (!num_args)
 260                 return count;
 261
 262         if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
 263                 mutex_lock(&cp->lock);
 264                 error = s390_vary_chpid(cp->chpid, 1);
 265                 mutex_unlock(&cp->lock);
 266         } else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
 267                 mutex_lock(&cp->lock);
 268                 error = s390_vary_chpid(cp->chpid, 0);
 269                 mutex_unlock(&cp->lock);
 270         } else
 271                 error = -EINVAL;
 272
 273         return error < 0 ? error : count;
 274 }
 275
 276 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 277
 278 static ssize_t chp_configure_show(struct device *dev,
 279                                   struct device_attribute *attr, char *buf)
 280 {
 281         struct channel_path *cp;
 282         int status;
 283
 284         cp = to_channelpath(dev);
 285         status = chp_info_get_status(cp->chpid);
 286         if (status < 0)
 287                 return status;
 288
 289         return snprintf(buf, PAGE_SIZE, "%d\n", status);
 290 }
 291
 292 static int cfg_wait_idle(void);
 293
 294 static ssize_t chp_configure_write(struct device *dev,
 295                                    struct device_attribute *attr,
 296                                    const char *buf, size_t count)
 297 {
 298         struct channel_path *cp;
 299         int val;
 300         char delim;
 301
 302         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 303                 return -EINVAL;
 304         if (val != 0 && val != 1)
 305                 return -EINVAL;
 306         cp = to_channelpath(dev);
 307         chp_cfg_schedule(cp->chpid, val);
 308         cfg_wait_idle();
 309
 310         return count;
 311 }
 312
 313 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 314
 315 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
 316                              char *buf)
 317 {
 318         struct channel_path *chp = to_channelpath(dev);
 319         u8 type;
 320
 321         mutex_lock(&chp->lock);
 322         type = chp->desc.desc;
 323         mutex_unlock(&chp->lock);
 324         return sprintf(buf, "%x\n", type);
 325 }
 326
 327 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 328
 329 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
 330                             char *buf)
 331 {
 332         struct channel_path *chp = to_channelpath(dev);
 333
 334         if (!chp)
 335                 return 0;
 336         if (chp->cmg == -1) /* channel measurements not available */
 337                 return sprintf(buf, "unknown\n");
 338         return sprintf(buf, "%x\n", chp->cmg);
 339 }
 340
 341 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 342
 343 static ssize_t chp_shared_show(struct device *dev,
 344                                struct device_attribute *attr, char *buf)
 345 {
 346         struct channel_path *chp = to_channelpath(dev);
 347
 348         if (!chp)
 349                 return 0;
 350         if (chp->shared == -1) /* channel measurements not available */
 351                 return sprintf(buf, "unknown\n");
 352         return sprintf(buf, "%x\n", chp->shared);
 353 }
 354
 355 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 356
 357 static struct attribute *chp_attrs[] = {
 358         &dev_attr_status.attr,
 359         &dev_attr_configure.attr,
 360         &dev_attr_type.attr,
 361         &dev_attr_cmg.attr,
 362         &dev_attr_shared.attr,
 363         NULL,
 364 };
 365
 366 static struct attribute_group chp_attr_group = {
 367         .attrs = chp_attrs,
 368 };
 369
 370 static void chp_release(struct device *dev)
 371 {
 372         struct channel_path *cp;
 373
 374         cp = to_channelpath(dev);
 375         kfree(cp);
 376 }
 377
 378 /**
 379  * chp_new - register a new channel-path
 380  * @chpid - channel-path ID
 381  *
 382  * Create and register data structure representing new channel-path. Return
 383  * zero on success, non-zero otherwise.
 384  */
 385 int chp_new(struct chp_id chpid)
 386 {
 387         struct channel_path *chp;
 388         int ret;
 389
 390         if (chp_is_registered(chpid))
 391                 return 0;
 392         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 393         if (!chp)
 394                 return -ENOMEM;
 395
 396         /* fill in status, etc. */
 397         chp->chpid = chpid;
 398         chp->state = 1;
 399         chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
 400         chp->dev.release = chp_release;
 401         mutex_init(&chp->lock);
 402
 403         /* Obtain channel path description and fill it in. */
 404         ret = chsc_determine_base_channel_path_desc(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_chsc_characteristics.scmc && css_chsc_characteristics.secm) {
 413                 ret = chsc_get_channel_measurement_chars(chp);
 414                 if (ret)
 415                         goto out_free;
 416         } else {
 417                 chp->cmg = -1;
 418         }
 419         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 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                 put_device(&chp->dev);
 427                 goto out;
 428         }
 429         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
 430         if (ret) {
 431                 device_unregister(&chp->dev);
 432                 goto out;
 433         }
 434         mutex_lock(&channel_subsystems[chpid.cssid]->mutex);
 435         if (channel_subsystems[chpid.cssid]->cm_enabled) {
 436                 ret = chp_add_cmg_attr(chp);
 437                 if (ret) {
 438                         sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
 439                         device_unregister(&chp->dev);
 440                         mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
 441                         goto out;
 442                 }
 443         }
 444         channel_subsystems[chpid.cssid]->chps[chpid.id] = chp;
 445         mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
 446         goto out;
 447 out_free:
 448         kfree(chp);
 449 out:
 450         return ret;
 451 }
 452
 453 /**
 454  * chp_get_chp_desc - return newly allocated channel-path description
 455  * @chpid: channel-path ID
 456  *
 457  * On success return a newly allocated copy of the channel-path description
 458  * data associated with the given channel-path ID. Return %NULL on error.
 459  */
 460 void *chp_get_chp_desc(struct chp_id chpid)
 461 {
 462         struct channel_path *chp;
 463         struct channel_path_desc *desc;
 464
 465         chp = chpid_to_chp(chpid);
 466         if (!chp)
 467                 return NULL;
 468         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
 469         if (!desc)
 470                 return NULL;
 471
 472         mutex_lock(&chp->lock);
 473         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
 474         mutex_unlock(&chp->lock);
 475         return desc;
 476 }
 477
 478 /**
 479  * chp_process_crw - process channel-path status change
 480  * @crw0: channel report-word to handler
 481  * @crw1: second channel-report word (always NULL)
 482  * @overflow: crw overflow indication
 483  *
 484  * Handle channel-report-words indicating that the status of a channel-path
 485  * has changed.
 486  */
 487 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 488                             int overflow)
 489 {
 490         struct chp_id chpid;
 491
 492         if (overflow) {
 493                 css_schedule_eval_all();
 494                 return;
 495         }
 496         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 497                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 498                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 499                       crw0->erc, crw0->rsid);
 500         /*
 501          * Check for solicited machine checks. These are
 502          * created by reset channel path and need not be
 503          * handled here.
 504          */
 505         if (crw0->slct) {
 506                 CIO_CRW_EVENT(2, "solicited machine check for "
 507                               "channel path %02X\n", crw0->rsid);
 508                 return;
 509         }
 510         chp_id_init(&chpid);
 511         chpid.id = crw0->rsid;
 512         switch (crw0->erc) {
 513         case CRW_ERC_IPARM: /* Path has come. */
 514                 if (!chp_is_registered(chpid))
 515                         chp_new(chpid);
 516                 chsc_chp_online(chpid);
 517                 break;
 518         case CRW_ERC_PERRI: /* Path has gone. */
 519         case CRW_ERC_PERRN:
 520                 chsc_chp_offline(chpid);
 521                 break;
 522         default:
 523                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 524                               crw0->erc);
 525         }
 526 }
 527
 528 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 529 {
 530         int i;
 531         int mask;
 532
 533         for (i = 0; i < 8; i++) {
 534                 mask = 0x80 >> i;
 535                 if (!(ssd->path_mask & mask))
 536                         continue;
 537                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 538                         continue;
 539                 if ((ssd->fla_valid_mask & mask) &&
 540                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 541                         continue;
 542                 return mask;
 543         }
 544         return 0;
 545 }
 546 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 547
 548 static inline int info_bit_num(struct chp_id id)
 549 {
 550         return id.id + id.cssid * (__MAX_CHPID + 1);
 551 }
 552
 553 /* Force chp_info refresh on next call to info_validate(). */
 554 static void info_expire(void)
 555 {
 556         mutex_lock(&info_lock);
 557         chp_info_expires = jiffies - 1;
 558         mutex_unlock(&info_lock);
 559 }
 560
 561 /* Ensure that chp_info is up-to-date. */
 562 static int info_update(void)
 563 {
 564         int rc;
 565
 566         mutex_lock(&info_lock);
 567         rc = 0;
 568         if (time_after(jiffies, chp_info_expires)) {
 569                 /* Data is too old, update. */
 570                 rc = sclp_chp_read_info(&chp_info);
 571                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 572         }
 573         mutex_unlock(&info_lock);
 574
 575         return rc;
 576 }
 577
 578 /**
 579  * chp_info_get_status - retrieve configure status of a channel-path
 580  * @chpid: channel-path ID
 581  *
 582  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 583  * 3 for not recognized. Return negative error code on error.
 584  */
 585 int chp_info_get_status(struct chp_id chpid)
 586 {
 587         int rc;
 588         int bit;
 589
 590         rc = info_update();
 591         if (rc)
 592                 return rc;
 593
 594         bit = info_bit_num(chpid);
 595         mutex_lock(&info_lock);
 596         if (!chp_test_bit(chp_info.recognized, bit))
 597                 rc = CHP_STATUS_NOT_RECOGNIZED;
 598         else if (chp_test_bit(chp_info.configured, bit))
 599                 rc = CHP_STATUS_CONFIGURED;
 600         else if (chp_test_bit(chp_info.standby, bit))
 601                 rc = CHP_STATUS_STANDBY;
 602         else
 603                 rc = CHP_STATUS_RESERVED;
 604         mutex_unlock(&info_lock);
 605
 606         return rc;
 607 }
 608
 609 /* Return configure task for chpid. */
 610 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 611 {
 612         return chp_cfg_task[chpid.cssid][chpid.id];
 613 }
 614
 615 /* Set configure task for chpid. */
 616 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 617 {
 618         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 619 }
 620
 621 /* Perform one configure/deconfigure request. Reschedule work function until
 622  * last request. */
 623 static void cfg_func(struct work_struct *work)
 624 {
 625         struct chp_id chpid;
 626         enum cfg_task_t t;
 627         int rc;
 628
 629         mutex_lock(&cfg_lock);
 630         t = cfg_none;
 631         chp_id_for_each(&chpid) {
 632                 t = cfg_get_task(chpid);
 633                 if (t != cfg_none) {
 634                         cfg_set_task(chpid, cfg_none);
 635                         break;
 636                 }
 637         }
 638         mutex_unlock(&cfg_lock);
 639
 640         switch (t) {
 641         case cfg_configure:
 642                 rc = sclp_chp_configure(chpid);
 643                 if (rc)
 644                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 645                                       "%d\n", chpid.cssid, chpid.id, rc);
 646                 else {
 647                         info_expire();
 648                         chsc_chp_online(chpid);
 649                 }
 650                 break;
 651         case cfg_deconfigure:
 652                 rc = sclp_chp_deconfigure(chpid);
 653                 if (rc)
 654                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 655                                       "%d\n", chpid.cssid, chpid.id, rc);
 656                 else {
 657                         info_expire();
 658                         chsc_chp_offline(chpid);
 659                 }
 660                 break;
 661         case cfg_none:
 662                 /* Get updated information after last change. */
 663                 info_update();
 664                 mutex_lock(&cfg_lock);
 665                 cfg_busy = 0;
 666                 mutex_unlock(&cfg_lock);
 667                 wake_up_interruptible(&cfg_wait_queue);
 668                 return;
 669         }
 670         queue_work(chp_wq, &cfg_work);
 671 }
 672
 673 /**
 674  * chp_cfg_schedule - schedule chpid configuration request
 675  * @chpid - channel-path ID
 676  * @configure - Non-zero for configure, zero for deconfigure
 677  *
 678  * Schedule a channel-path configuration/deconfiguration request.
 679  */
 680 void chp_cfg_schedule(struct chp_id chpid, int configure)
 681 {
 682         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 683                       configure);
 684         mutex_lock(&cfg_lock);
 685         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 686         cfg_busy = 1;
 687         mutex_unlock(&cfg_lock);
 688         queue_work(chp_wq, &cfg_work);
 689 }
 690
 691 /**
 692  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 693  * @chpid - channel-path ID
 694  *
 695  * Cancel an active channel-path deconfiguration request if it has not yet
 696  * been performed.
 697  */
 698 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 699 {
 700         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 701         mutex_lock(&cfg_lock);
 702         if (cfg_get_task(chpid) == cfg_deconfigure)
 703                 cfg_set_task(chpid, cfg_none);
 704         mutex_unlock(&cfg_lock);
 705 }
 706
 707 static int cfg_wait_idle(void)
 708 {
 709         if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
 710                 return -ERESTARTSYS;
 711         return 0;
 712 }
 713
 714 static int __init chp_init(void)
 715 {
 716         struct chp_id chpid;
 717         int ret;
 718
 719         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 720         if (ret)
 721                 return ret;
 722         chp_wq = create_singlethread_workqueue("cio_chp");
 723         if (!chp_wq) {
 724                 crw_unregister_handler(CRW_RSC_CPATH);
 725                 return -ENOMEM;
 726         }
 727         INIT_WORK(&cfg_work, cfg_func);
 728         init_waitqueue_head(&cfg_wait_queue);
 729         if (info_update())
 730                 return 0;
 731         /* Register available channel-paths. */
 732         chp_id_for_each(&chpid) {
 733                 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
 734                         chp_new(chpid);
 735         }
 736
 737         return 0;
 738 }
 739
 740 subsys_initcall(chp_init);