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_SPINLOCK(cfg_lock);
  41
  42 /* Map for channel-path status. */
  43 static struct sclp_chp_info chp_info;
  44 static DEFINE_MUTEX(info_lock);
  45
  46 /* Time after which channel-path status may be outdated. */
  47 static unsigned long chp_info_expires;
  48
  49 static struct work_struct cfg_work;
  50
  51 /* Wait queue for configure completion events. */
  52 static wait_queue_head_t cfg_wait_queue;
  53
  54 /* Set vary state for given chpid. */
  55 static void set_chp_logically_online(struct chp_id chpid, int onoff)
  56 {
  57         chpid_to_chp(chpid)->state = onoff;
  58 }
  59
  60 /* On success return 0 if channel-path is varied offline, 1 if it is varied
  61  * online. Return -ENODEV if channel-path is not registered. */
  62 int chp_get_status(struct chp_id chpid)
  63 {
  64         return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
  65 }
  66
  67 /**
  68  * chp_get_sch_opm - return opm for subchannel
  69  * @sch: subchannel
  70  *
  71  * Calculate and return the operational path mask (opm) based on the chpids
  72  * used by the subchannel and the status of the associated channel-paths.
  73  */
  74 u8 chp_get_sch_opm(struct subchannel *sch)
  75 {
  76         struct chp_id chpid;
  77         int opm;
  78         int i;
  79
  80         opm = 0;
  81         chp_id_init(&chpid);
  82         for (i = 0; i < 8; i++) {
  83                 opm <<= 1;
  84                 chpid.id = sch->schib.pmcw.chpid[i];
  85                 if (chp_get_status(chpid) != 0)
  86                         opm |= 1;
  87         }
  88         return opm;
  89 }
  90 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
  91
  92 /**
  93  * chp_is_registered - check if a channel-path is registered
  94  * @chpid: channel-path ID
  95  *
  96  * Return non-zero if a channel-path with the given chpid is registered,
  97  * zero otherwise.
  98  */
  99 int chp_is_registered(struct chp_id chpid)
 100 {
 101         return chpid_to_chp(chpid) != NULL;
 102 }
 103
 104 /*
 105  * Function: s390_vary_chpid
 106  * Varies the specified chpid online or offline
 107  */
 108 static int s390_vary_chpid(struct chp_id chpid, int on)
 109 {
 110         char dbf_text[15];
 111         int status;
 112
 113         sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
 114                 chpid.id);
 115         CIO_TRACE_EVENT(2, dbf_text);
 116
 117         status = chp_get_status(chpid);
 118         if (!on && !status)
 119                 return 0;
 120
 121         set_chp_logically_online(chpid, on);
 122         chsc_chp_vary(chpid, on);
 123         return 0;
 124 }
 125
 126 /*
 127  * Channel measurement related functions
 128  */
 129 static ssize_t chp_measurement_chars_read(struct file *filp,
 130                                           struct kobject *kobj,
 131                                           struct bin_attribute *bin_attr,
 132                                           char *buf, loff_t off, size_t count)
 133 {
 134         struct channel_path *chp;
 135         struct device *device;
 136
 137         device = container_of(kobj, struct device, kobj);
 138         chp = to_channelpath(device);
 139         if (chp->cmg == -1)
 140                 return 0;
 141
 142         return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
 143                                        sizeof(chp->cmg_chars));
 144 }
 145
 146 static struct bin_attribute chp_measurement_chars_attr = {
 147         .attr = {
 148                 .name = "measurement_chars",
 149                 .mode = S_IRUSR,
 150         },
 151         .size = sizeof(struct cmg_chars),
 152         .read = chp_measurement_chars_read,
 153 };
 154
 155 static void chp_measurement_copy_block(struct cmg_entry *buf,
 156                                        struct channel_subsystem *css,
 157                                        struct chp_id chpid)
 158 {
 159         void *area;
 160         struct cmg_entry *entry, reference_buf;
 161         int idx;
 162
 163         if (chpid.id < 128) {
 164                 area = css->cub_addr1;
 165                 idx = chpid.id;
 166         } else {
 167                 area = css->cub_addr2;
 168                 idx = chpid.id - 128;
 169         }
 170         entry = area + (idx * sizeof(struct cmg_entry));
 171         do {
 172                 memcpy(buf, entry, sizeof(*entry));
 173                 memcpy(&reference_buf, entry, sizeof(*entry));
 174         } while (reference_buf.values[0] != buf->values[0]);
 175 }
 176
 177 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
 178                                     struct bin_attribute *bin_attr,
 179                                     char *buf, loff_t off, size_t count)
 180 {
 181         struct channel_path *chp;
 182         struct channel_subsystem *css;
 183         struct device *device;
 184         unsigned int size;
 185
 186         device = container_of(kobj, struct device, kobj);
 187         chp = to_channelpath(device);
 188         css = to_css(chp->dev.parent);
 189
 190         size = sizeof(struct cmg_entry);
 191
 192         /* Only allow single reads. */
 193         if (off || count < size)
 194                 return 0;
 195         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
 196         count = size;
 197         return count;
 198 }
 199
 200 static struct bin_attribute chp_measurement_attr = {
 201         .attr = {
 202                 .name = "measurement",
 203                 .mode = S_IRUSR,
 204         },
 205         .size = sizeof(struct cmg_entry),
 206         .read = chp_measurement_read,
 207 };
 208
 209 void chp_remove_cmg_attr(struct channel_path *chp)
 210 {
 211         device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 212         device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 213 }
 214
 215 int chp_add_cmg_attr(struct channel_path *chp)
 216 {
 217         int ret;
 218
 219         ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 220         if (ret)
 221                 return ret;
 222         ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 223         if (ret)
 224                 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 225         return ret;
 226 }
 227
 228 /*
 229  * Files for the channel path entries.
 230  */
 231 static ssize_t chp_status_show(struct device *dev,
 232                                struct device_attribute *attr, char *buf)
 233 {
 234         struct channel_path *chp = to_channelpath(dev);
 235         int status;
 236
 237         mutex_lock(&chp->lock);
 238         status = chp->state;
 239         mutex_unlock(&chp->lock);
 240
 241         return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
 242 }
 243
 244 static ssize_t chp_status_write(struct device *dev,
 245                                 struct device_attribute *attr,
 246                                 const char *buf, size_t count)
 247 {
 248         struct channel_path *cp = to_channelpath(dev);
 249         char cmd[10];
 250         int num_args;
 251         int error;
 252
 253         num_args = sscanf(buf, "%5s", cmd);
 254         if (!num_args)
 255                 return count;
 256
 257         if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
 258                 mutex_lock(&cp->lock);
 259                 error = s390_vary_chpid(cp->chpid, 1);
 260                 mutex_unlock(&cp->lock);
 261         } else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
 262                 mutex_lock(&cp->lock);
 263                 error = s390_vary_chpid(cp->chpid, 0);
 264                 mutex_unlock(&cp->lock);
 265         } else
 266                 error = -EINVAL;
 267
 268         return error < 0 ? error : count;
 269 }
 270
 271 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 272
 273 static ssize_t chp_configure_show(struct device *dev,
 274                                   struct device_attribute *attr, char *buf)
 275 {
 276         struct channel_path *cp;
 277         int status;
 278
 279         cp = to_channelpath(dev);
 280         status = chp_info_get_status(cp->chpid);
 281         if (status < 0)
 282                 return status;
 283
 284         return snprintf(buf, PAGE_SIZE, "%d\n", status);
 285 }
 286
 287 static int cfg_wait_idle(void);
 288
 289 static ssize_t chp_configure_write(struct device *dev,
 290                                    struct device_attribute *attr,
 291                                    const char *buf, size_t count)
 292 {
 293         struct channel_path *cp;
 294         int val;
 295         char delim;
 296
 297         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 298                 return -EINVAL;
 299         if (val != 0 && val != 1)
 300                 return -EINVAL;
 301         cp = to_channelpath(dev);
 302         chp_cfg_schedule(cp->chpid, val);
 303         cfg_wait_idle();
 304
 305         return count;
 306 }
 307
 308 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 309
 310 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
 311                              char *buf)
 312 {
 313         struct channel_path *chp = to_channelpath(dev);
 314         u8 type;
 315
 316         mutex_lock(&chp->lock);
 317         type = chp->desc.desc;
 318         mutex_unlock(&chp->lock);
 319         return sprintf(buf, "%x\n", type);
 320 }
 321
 322 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 323
 324 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
 325                             char *buf)
 326 {
 327         struct channel_path *chp = to_channelpath(dev);
 328
 329         if (!chp)
 330                 return 0;
 331         if (chp->cmg == -1) /* channel measurements not available */
 332                 return sprintf(buf, "unknown\n");
 333         return sprintf(buf, "%x\n", chp->cmg);
 334 }
 335
 336 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 337
 338 static ssize_t chp_shared_show(struct device *dev,
 339                                struct device_attribute *attr, char *buf)
 340 {
 341         struct channel_path *chp = to_channelpath(dev);
 342
 343         if (!chp)
 344                 return 0;
 345         if (chp->shared == -1) /* channel measurements not available */
 346                 return sprintf(buf, "unknown\n");
 347         return sprintf(buf, "%x\n", chp->shared);
 348 }
 349
 350 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 351
 352 static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
 353                              char *buf)
 354 {
 355         struct channel_path *chp = to_channelpath(dev);
 356         ssize_t rc;
 357
 358         mutex_lock(&chp->lock);
 359         if (chp->desc_fmt1.flags & 0x10)
 360                 rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid);
 361         else
 362                 rc = 0;
 363         mutex_unlock(&chp->lock);
 364
 365         return rc;
 366 }
 367 static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
 368
 369 static ssize_t chp_chid_external_show(struct device *dev,
 370                                       struct device_attribute *attr, char *buf)
 371 {
 372         struct channel_path *chp = to_channelpath(dev);
 373         ssize_t rc;
 374
 375         mutex_lock(&chp->lock);
 376         if (chp->desc_fmt1.flags & 0x10)
 377                 rc = sprintf(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
 378         else
 379                 rc = 0;
 380         mutex_unlock(&chp->lock);
 381
 382         return rc;
 383 }
 384 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
 385
 386 static struct attribute *chp_attrs[] = {
 387         &dev_attr_status.attr,
 388         &dev_attr_configure.attr,
 389         &dev_attr_type.attr,
 390         &dev_attr_cmg.attr,
 391         &dev_attr_shared.attr,
 392         &dev_attr_chid.attr,
 393         &dev_attr_chid_external.attr,
 394         NULL,
 395 };
 396 static struct attribute_group chp_attr_group = {
 397         .attrs = chp_attrs,
 398 };
 399 static const struct attribute_group *chp_attr_groups[] = {
 400         &chp_attr_group,
 401         NULL,
 402 };
 403
 404 static void chp_release(struct device *dev)
 405 {
 406         struct channel_path *cp;
 407
 408         cp = to_channelpath(dev);
 409         kfree(cp);
 410 }
 411
 412 /**
 413  * chp_update_desc - update channel-path description
 414  * @chp - channel-path
 415  *
 416  * Update the channel-path description of the specified channel-path
 417  * including channel measurement related information.
 418  * Return zero on success, non-zero otherwise.
 419  */
 420 int chp_update_desc(struct channel_path *chp)
 421 {
 422         int rc;
 423
 424         rc = chsc_determine_base_channel_path_desc(chp->chpid, &chp->desc);
 425         if (rc)
 426                 return rc;
 427
 428         /*
 429          * Fetching the following data is optional. Not all machines or
 430          * hypervisors implement the required chsc commands.
 431          */
 432         chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
 433         chsc_get_channel_measurement_chars(chp);
 434
 435         return 0;
 436 }
 437
 438 /**
 439  * chp_new - register a new channel-path
 440  * @chpid - channel-path ID
 441  *
 442  * Create and register data structure representing new channel-path. Return
 443  * zero on success, non-zero otherwise.
 444  */
 445 int chp_new(struct chp_id chpid)
 446 {
 447         struct channel_subsystem *css = css_by_id(chpid.cssid);
 448         struct channel_path *chp;
 449         int ret;
 450
 451         if (chp_is_registered(chpid))
 452                 return 0;
 453         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 454         if (!chp)
 455                 return -ENOMEM;
 456
 457         /* fill in status, etc. */
 458         chp->chpid = chpid;
 459         chp->state = 1;
 460         chp->dev.parent = &css->device;
 461         chp->dev.groups = chp_attr_groups;
 462         chp->dev.release = chp_release;
 463         mutex_init(&chp->lock);
 464
 465         /* Obtain channel path description and fill it in. */
 466         ret = chp_update_desc(chp);
 467         if (ret)
 468                 goto out_free;
 469         if ((chp->desc.flags & 0x80) == 0) {
 470                 ret = -ENODEV;
 471                 goto out_free;
 472         }
 473         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 474
 475         /* make it known to the system */
 476         ret = device_register(&chp->dev);
 477         if (ret) {
 478                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 479                               chpid.cssid, chpid.id, ret);
 480                 put_device(&chp->dev);
 481                 goto out;
 482         }
 483         mutex_lock(&css->mutex);
 484         if (css->cm_enabled) {
 485                 ret = chp_add_cmg_attr(chp);
 486                 if (ret) {
 487                         device_unregister(&chp->dev);
 488                         mutex_unlock(&css->mutex);
 489                         goto out;
 490                 }
 491         }
 492         css->chps[chpid.id] = chp;
 493         mutex_unlock(&css->mutex);
 494         goto out;
 495 out_free:
 496         kfree(chp);
 497 out:
 498         return ret;
 499 }
 500
 501 /**
 502  * chp_get_chp_desc - return newly allocated channel-path description
 503  * @chpid: channel-path ID
 504  *
 505  * On success return a newly allocated copy of the channel-path description
 506  * data associated with the given channel-path ID. Return %NULL on error.
 507  */
 508 struct channel_path_desc *chp_get_chp_desc(struct chp_id chpid)
 509 {
 510         struct channel_path *chp;
 511         struct channel_path_desc *desc;
 512
 513         chp = chpid_to_chp(chpid);
 514         if (!chp)
 515                 return NULL;
 516         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
 517         if (!desc)
 518                 return NULL;
 519
 520         mutex_lock(&chp->lock);
 521         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
 522         mutex_unlock(&chp->lock);
 523         return desc;
 524 }
 525
 526 /**
 527  * chp_process_crw - process channel-path status change
 528  * @crw0: channel report-word to handler
 529  * @crw1: second channel-report word (always NULL)
 530  * @overflow: crw overflow indication
 531  *
 532  * Handle channel-report-words indicating that the status of a channel-path
 533  * has changed.
 534  */
 535 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 536                             int overflow)
 537 {
 538         struct chp_id chpid;
 539
 540         if (overflow) {
 541                 css_schedule_eval_all();
 542                 return;
 543         }
 544         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 545                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 546                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 547                       crw0->erc, crw0->rsid);
 548         /*
 549          * Check for solicited machine checks. These are
 550          * created by reset channel path and need not be
 551          * handled here.
 552          */
 553         if (crw0->slct) {
 554                 CIO_CRW_EVENT(2, "solicited machine check for "
 555                               "channel path %02X\n", crw0->rsid);
 556                 return;
 557         }
 558         chp_id_init(&chpid);
 559         chpid.id = crw0->rsid;
 560         switch (crw0->erc) {
 561         case CRW_ERC_IPARM: /* Path has come. */
 562                 if (!chp_is_registered(chpid))
 563                         chp_new(chpid);
 564                 chsc_chp_online(chpid);
 565                 break;
 566         case CRW_ERC_PERRI: /* Path has gone. */
 567         case CRW_ERC_PERRN:
 568                 chsc_chp_offline(chpid);
 569                 break;
 570         default:
 571                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 572                               crw0->erc);
 573         }
 574 }
 575
 576 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 577 {
 578         int i;
 579         int mask;
 580
 581         for (i = 0; i < 8; i++) {
 582                 mask = 0x80 >> i;
 583                 if (!(ssd->path_mask & mask))
 584                         continue;
 585                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 586                         continue;
 587                 if ((ssd->fla_valid_mask & mask) &&
 588                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 589                         continue;
 590                 return mask;
 591         }
 592         return 0;
 593 }
 594 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 595
 596 static inline int info_bit_num(struct chp_id id)
 597 {
 598         return id.id + id.cssid * (__MAX_CHPID + 1);
 599 }
 600
 601 /* Force chp_info refresh on next call to info_validate(). */
 602 static void info_expire(void)
 603 {
 604         mutex_lock(&info_lock);
 605         chp_info_expires = jiffies - 1;
 606         mutex_unlock(&info_lock);
 607 }
 608
 609 /* Ensure that chp_info is up-to-date. */
 610 static int info_update(void)
 611 {
 612         int rc;
 613
 614         mutex_lock(&info_lock);
 615         rc = 0;
 616         if (time_after(jiffies, chp_info_expires)) {
 617                 /* Data is too old, update. */
 618                 rc = sclp_chp_read_info(&chp_info);
 619                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 620         }
 621         mutex_unlock(&info_lock);
 622
 623         return rc;
 624 }
 625
 626 /**
 627  * chp_info_get_status - retrieve configure status of a channel-path
 628  * @chpid: channel-path ID
 629  *
 630  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 631  * 3 for not recognized. Return negative error code on error.
 632  */
 633 int chp_info_get_status(struct chp_id chpid)
 634 {
 635         int rc;
 636         int bit;
 637
 638         rc = info_update();
 639         if (rc)
 640                 return rc;
 641
 642         bit = info_bit_num(chpid);
 643         mutex_lock(&info_lock);
 644         if (!chp_test_bit(chp_info.recognized, bit))
 645                 rc = CHP_STATUS_NOT_RECOGNIZED;
 646         else if (chp_test_bit(chp_info.configured, bit))
 647                 rc = CHP_STATUS_CONFIGURED;
 648         else if (chp_test_bit(chp_info.standby, bit))
 649                 rc = CHP_STATUS_STANDBY;
 650         else
 651                 rc = CHP_STATUS_RESERVED;
 652         mutex_unlock(&info_lock);
 653
 654         return rc;
 655 }
 656
 657 /* Return configure task for chpid. */
 658 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 659 {
 660         return chp_cfg_task[chpid.cssid][chpid.id];
 661 }
 662
 663 /* Set configure task for chpid. */
 664 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 665 {
 666         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 667 }
 668
 669 /* Fetch the first configure task. Set chpid accordingly. */
 670 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
 671 {
 672         enum cfg_task_t t = cfg_none;
 673
 674         chp_id_for_each(chpid) {
 675                 t = cfg_get_task(*chpid);
 676                 if (t != cfg_none)
 677                         break;
 678         }
 679
 680         return t;
 681 }
 682
 683 /* Perform one configure/deconfigure request. Reschedule work function until
 684  * last request. */
 685 static void cfg_func(struct work_struct *work)
 686 {
 687         struct chp_id chpid;
 688         enum cfg_task_t t;
 689         int rc;
 690
 691         spin_lock(&cfg_lock);
 692         t = chp_cfg_fetch_task(&chpid);
 693         spin_unlock(&cfg_lock);
 694
 695         switch (t) {
 696         case cfg_configure:
 697                 rc = sclp_chp_configure(chpid);
 698                 if (rc)
 699                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 700                                       "%d\n", chpid.cssid, chpid.id, rc);
 701                 else {
 702                         info_expire();
 703                         chsc_chp_online(chpid);
 704                 }
 705                 break;
 706         case cfg_deconfigure:
 707                 rc = sclp_chp_deconfigure(chpid);
 708                 if (rc)
 709                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 710                                       "%d\n", chpid.cssid, chpid.id, rc);
 711                 else {
 712                         info_expire();
 713                         chsc_chp_offline(chpid);
 714                 }
 715                 break;
 716         case cfg_none:
 717                 /* Get updated information after last change. */
 718                 info_update();
 719                 wake_up_interruptible(&cfg_wait_queue);
 720                 return;
 721         }
 722         spin_lock(&cfg_lock);
 723         if (t == cfg_get_task(chpid))
 724                 cfg_set_task(chpid, cfg_none);
 725         spin_unlock(&cfg_lock);
 726         schedule_work(&cfg_work);
 727 }
 728
 729 /**
 730  * chp_cfg_schedule - schedule chpid configuration request
 731  * @chpid - channel-path ID
 732  * @configure - Non-zero for configure, zero for deconfigure
 733  *
 734  * Schedule a channel-path configuration/deconfiguration request.
 735  */
 736 void chp_cfg_schedule(struct chp_id chpid, int configure)
 737 {
 738         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 739                       configure);
 740         spin_lock(&cfg_lock);
 741         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 742         spin_unlock(&cfg_lock);
 743         schedule_work(&cfg_work);
 744 }
 745
 746 /**
 747  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 748  * @chpid - channel-path ID
 749  *
 750  * Cancel an active channel-path deconfiguration request if it has not yet
 751  * been performed.
 752  */
 753 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 754 {
 755         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 756         spin_lock(&cfg_lock);
 757         if (cfg_get_task(chpid) == cfg_deconfigure)
 758                 cfg_set_task(chpid, cfg_none);
 759         spin_unlock(&cfg_lock);
 760 }
 761
 762 static bool cfg_idle(void)
 763 {
 764         struct chp_id chpid;
 765         enum cfg_task_t t;
 766
 767         spin_lock(&cfg_lock);
 768         t = chp_cfg_fetch_task(&chpid);
 769         spin_unlock(&cfg_lock);
 770
 771         return t == cfg_none;
 772 }
 773
 774 static int cfg_wait_idle(void)
 775 {
 776         if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
 777                 return -ERESTARTSYS;
 778         return 0;
 779 }
 780
 781 static int __init chp_init(void)
 782 {
 783         struct chp_id chpid;
 784         int state, ret;
 785
 786         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 787         if (ret)
 788                 return ret;
 789         INIT_WORK(&cfg_work, cfg_func);
 790         init_waitqueue_head(&cfg_wait_queue);
 791         if (info_update())
 792                 return 0;
 793         /* Register available channel-paths. */
 794         chp_id_for_each(&chpid) {
 795                 state = chp_info_get_status(chpid);
 796                 if (state == CHP_STATUS_CONFIGURED ||
 797                     state == CHP_STATUS_STANDBY)
 798                         chp_new(chpid);
 799         }
 800
 801         return 0;
 802 }
 803
 804 subsys_initcall(chp_init);