drivers/s390/cio/chp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 1999, 2010
   4  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
   5  *               Arnd Bergmann (arndb@de.ibm.com)
   6  *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   7  */
   8
   9 #include <linux/bug.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/export.h>
  13 #include <linux/sched.h>
  14 #include <linux/init.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/wait.h>
  17 #include <linux/mutex.h>
  18 #include <linux/errno.h>
  19 #include <linux/slab.h>
  20 #include <asm/chpid.h>
  21 #include <asm/sclp.h>
  22 #include <asm/crw.h>
  23
  24 #include "cio.h"
  25 #include "css.h"
  26 #include "ioasm.h"
  27 #include "cio_debug.h"
  28 #include "chp.h"
  29
  30 #define to_channelpath(device) container_of(device, struct channel_path, dev)
  31 #define CHP_INFO_UPDATE_INTERVAL        1*HZ
  32
  33 enum cfg_task_t {
  34         cfg_none,
  35         cfg_configure,
  36         cfg_deconfigure
  37 };
  38
  39 /* Map for pending configure tasks. */
  40 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
  41 static DEFINE_SPINLOCK(cfg_lock);
  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  47 /* Time after which channel-path status may be outdated.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 static struct work_struct cfg_work;
  51
  52 /* Wait queue for configure completion events. */
  53 static wait_queue_head_t cfg_wait_queue;
  54
  55 /* Set vary state for given chpid. */
  56 static void set_chp_logically_online(struct chp_id chpid, int onoff)
  57 {
  58         chpid_to_chp(chpid)->state = onoff;
  59 }
  60
  61 /* On success return 0 if channel-path is varied offline, 1 if it is varied
  62  * online. Return -ENODEV if channel-path is not registered. */
  63 int chp_get_status(struct chp_id chpid)
  64 {
  65         return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
  66 }
  67
  68 /**
  69  * chp_get_sch_opm - return opm for subchannel
  70  * @sch: subchannel
  71  *
  72  * Calculate and return the operational path mask (opm) based on the chpids
  73  * used by the subchannel and the status of the associated channel-paths.
  74  */
  75 u8 chp_get_sch_opm(struct subchannel *sch)
  76 {
  77         struct chp_id chpid;
  78         int opm;
  79         int i;
  80
  81         opm = 0;
  82         chp_id_init(&chpid);
  83         for (i = 0; i < 8; i++) {
  84                 opm <<= 1;
  85                 chpid.id = sch->schib.pmcw.chpid[i];
  86                 if (chp_get_status(chpid) != 0)
  87                         opm |= 1;
  88         }
  89         return opm;
  90 }
  91 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
  92
  93 /**
  94  * chp_is_registered - check if a channel-path is registered
  95  * @chpid: channel-path ID
  96  *
  97  * Return non-zero if a channel-path with the given chpid is registered,
  98  * zero otherwise.
  99  */
 100 int chp_is_registered(struct chp_id chpid)
 101 {
 102         return chpid_to_chp(chpid) != NULL;
 103 }
 104
 105 /*
 106  * Function: s390_vary_chpid
 107  * Varies the specified chpid online or offline
 108  */
 109 static int s390_vary_chpid(struct chp_id chpid, int on)
 110 {
 111         char dbf_text[15];
 112         int status;
 113
 114         sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
 115                 chpid.id);
 116         CIO_TRACE_EVENT(2, dbf_text);
 117
 118         status = chp_get_status(chpid);
 119         if (!on && !status)
 120                 return 0;
 121
 122         set_chp_logically_online(chpid, on);
 123         chsc_chp_vary(chpid, on);
 124         return 0;
 125 }
 126
 127 /*
 128  * Channel measurement related functions
 129  */
 130 static ssize_t chp_measurement_chars_read(struct file *filp,
 131                                           struct kobject *kobj,
 132                                           struct bin_attribute *bin_attr,
 133                                           char *buf, loff_t off, size_t count)
 134 {
 135         struct channel_path *chp;
 136         struct device *device;
 137
 138         device = container_of(kobj, struct device, kobj);
 139         chp = to_channelpath(device);
 140         if (chp->cmg == -1)
 141                 return 0;
 142
 143         return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
 144                                        sizeof(chp->cmg_chars));
 145 }
 146
 147 static const struct bin_attribute chp_measurement_chars_attr = {
 148         .attr = {
 149                 .name = "measurement_chars",
 150                 .mode = S_IRUSR,
 151         },
 152         .size = sizeof(struct cmg_chars),
 153         .read = chp_measurement_chars_read,
 154 };
 155
 156 static void chp_measurement_copy_block(struct cmg_entry *buf,
 157                                        struct channel_subsystem *css,
 158                                        struct chp_id chpid)
 159 {
 160         void *area;
 161         struct cmg_entry *entry, reference_buf;
 162         int idx;
 163
 164         if (chpid.id < 128) {
 165                 area = css->cub_addr1;
 166                 idx = chpid.id;
 167         } else {
 168                 area = css->cub_addr2;
 169                 idx = chpid.id - 128;
 170         }
 171         entry = area + (idx * sizeof(struct cmg_entry));
 172         do {
 173                 memcpy(buf, entry, sizeof(*entry));
 174                 memcpy(&reference_buf, entry, sizeof(*entry));
 175         } while (reference_buf.values[0] != buf->values[0]);
 176 }
 177
 178 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
 179                                     struct bin_attribute *bin_attr,
 180                                     char *buf, loff_t off, size_t count)
 181 {
 182         struct channel_path *chp;
 183         struct channel_subsystem *css;
 184         struct device *device;
 185         unsigned int size;
 186
 187         device = container_of(kobj, struct device, kobj);
 188         chp = to_channelpath(device);
 189         css = to_css(chp->dev.parent);
 190
 191         size = sizeof(struct cmg_entry);
 192
 193         /* Only allow single reads. */
 194         if (off || count < size)
 195                 return 0;
 196         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
 197         count = size;
 198         return count;
 199 }
 200
 201 static const struct bin_attribute chp_measurement_attr = {
 202         .attr = {
 203                 .name = "measurement",
 204                 .mode = S_IRUSR,
 205         },
 206         .size = sizeof(struct cmg_entry),
 207         .read = chp_measurement_read,
 208 };
 209
 210 void chp_remove_cmg_attr(struct channel_path *chp)
 211 {
 212         device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 213         device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 214 }
 215
 216 int chp_add_cmg_attr(struct channel_path *chp)
 217 {
 218         int ret;
 219
 220         ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 221         if (ret)
 222                 return ret;
 223         ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 224         if (ret)
 225                 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 226         return ret;
 227 }
 228
 229 /*
 230  * Files for the channel path entries.
 231  */
 232 static ssize_t chp_status_show(struct device *dev,
 233                                struct device_attribute *attr, char *buf)
 234 {
 235         struct channel_path *chp = to_channelpath(dev);
 236         int status;
 237
 238         mutex_lock(&chp->lock);
 239         status = chp->state;
 240         mutex_unlock(&chp->lock);
 241
 242         return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
 243 }
 244
 245 static ssize_t chp_status_write(struct device *dev,
 246                                 struct device_attribute *attr,
 247                                 const char *buf, size_t count)
 248 {
 249         struct channel_path *cp = to_channelpath(dev);
 250         char cmd[10];
 251         int num_args;
 252         int error;
 253
 254         num_args = sscanf(buf, "%5s", cmd);
 255         if (!num_args)
 256                 return count;
 257
 258         if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
 259                 mutex_lock(&cp->lock);
 260                 error = s390_vary_chpid(cp->chpid, 1);
 261                 mutex_unlock(&cp->lock);
 262         } else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
 263                 mutex_lock(&cp->lock);
 264                 error = s390_vary_chpid(cp->chpid, 0);
 265                 mutex_unlock(&cp->lock);
 266         } else
 267                 error = -EINVAL;
 268
 269         return error < 0 ? error : count;
 270 }
 271
 272 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 273
 274 static ssize_t chp_configure_show(struct device *dev,
 275                                   struct device_attribute *attr, char *buf)
 276 {
 277         struct channel_path *cp;
 278         int status;
 279
 280         cp = to_channelpath(dev);
 281         status = chp_info_get_status(cp->chpid);
 282         if (status < 0)
 283                 return status;
 284
 285         return snprintf(buf, PAGE_SIZE, "%d\n", status);
 286 }
 287
 288 static int cfg_wait_idle(void);
 289
 290 static ssize_t chp_configure_write(struct device *dev,
 291                                    struct device_attribute *attr,
 292                                    const char *buf, size_t count)
 293 {
 294         struct channel_path *cp;
 295         int val;
 296         char delim;
 297
 298         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 299                 return -EINVAL;
 300         if (val != 0 && val != 1)
 301                 return -EINVAL;
 302         cp = to_channelpath(dev);
 303         chp_cfg_schedule(cp->chpid, val);
 304         cfg_wait_idle();
 305
 306         return count;
 307 }
 308
 309 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 310
 311 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
 312                              char *buf)
 313 {
 314         struct channel_path *chp = to_channelpath(dev);
 315         u8 type;
 316
 317         mutex_lock(&chp->lock);
 318         type = chp->desc.desc;
 319         mutex_unlock(&chp->lock);
 320         return sprintf(buf, "%x\n", type);
 321 }
 322
 323 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 324
 325 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
 326                             char *buf)
 327 {
 328         struct channel_path *chp = to_channelpath(dev);
 329
 330         if (!chp)
 331                 return 0;
 332         if (chp->cmg == -1) /* channel measurements not available */
 333                 return sprintf(buf, "unknown\n");
 334         return sprintf(buf, "%x\n", chp->cmg);
 335 }
 336
 337 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 338
 339 static ssize_t chp_shared_show(struct device *dev,
 340                                struct device_attribute *attr, char *buf)
 341 {
 342         struct channel_path *chp = to_channelpath(dev);
 343
 344         if (!chp)
 345                 return 0;
 346         if (chp->shared == -1) /* channel measurements not available */
 347                 return sprintf(buf, "unknown\n");
 348         return sprintf(buf, "%x\n", chp->shared);
 349 }
 350
 351 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 352
 353 static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
 354                              char *buf)
 355 {
 356         struct channel_path *chp = to_channelpath(dev);
 357         ssize_t rc;
 358
 359         mutex_lock(&chp->lock);
 360         if (chp->desc_fmt1.flags & 0x10)
 361                 rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid);
 362         else
 363                 rc = 0;
 364         mutex_unlock(&chp->lock);
 365
 366         return rc;
 367 }
 368 static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
 369
 370 static ssize_t chp_chid_external_show(struct device *dev,
 371                                       struct device_attribute *attr, char *buf)
 372 {
 373         struct channel_path *chp = to_channelpath(dev);
 374         ssize_t rc;
 375
 376         mutex_lock(&chp->lock);
 377         if (chp->desc_fmt1.flags & 0x10)
 378                 rc = sprintf(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
 379         else
 380                 rc = 0;
 381         mutex_unlock(&chp->lock);
 382
 383         return rc;
 384 }
 385 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
 386
 387 static struct attribute *chp_attrs[] = {
 388         &dev_attr_status.attr,
 389         &dev_attr_configure.attr,
 390         &dev_attr_type.attr,
 391         &dev_attr_cmg.attr,
 392         &dev_attr_shared.attr,
 393         &dev_attr_chid.attr,
 394         &dev_attr_chid_external.attr,
 395         NULL,
 396 };
 397 static struct attribute_group chp_attr_group = {
 398         .attrs = chp_attrs,
 399 };
 400 static const struct attribute_group *chp_attr_groups[] = {
 401         &chp_attr_group,
 402         NULL,
 403 };
 404
 405 static void chp_release(struct device *dev)
 406 {
 407         struct channel_path *cp;
 408
 409         cp = to_channelpath(dev);
 410         kfree(cp);
 411 }
 412
 413 /**
 414  * chp_update_desc - update channel-path description
 415  * @chp - channel-path
 416  *
 417  * Update the channel-path description of the specified channel-path
 418  * including channel measurement related information.
 419  * Return zero on success, non-zero otherwise.
 420  */
 421 int chp_update_desc(struct channel_path *chp)
 422 {
 423         int rc;
 424
 425         rc = chsc_determine_base_channel_path_desc(chp->chpid, &chp->desc);
 426         if (rc)
 427                 return rc;
 428
 429         /*
 430          * Fetching the following data is optional. Not all machines or
 431          * hypervisors implement the required chsc commands.
 432          */
 433         chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
 434         chsc_get_channel_measurement_chars(chp);
 435
 436         return 0;
 437 }
 438
 439 /**
 440  * chp_new - register a new channel-path
 441  * @chpid - channel-path ID
 442  *
 443  * Create and register data structure representing new channel-path. Return
 444  * zero on success, non-zero otherwise.
 445  */
 446 int chp_new(struct chp_id chpid)
 447 {
 448         struct channel_subsystem *css = css_by_id(chpid.cssid);
 449         struct channel_path *chp;
 450         int ret;
 451
 452         if (chp_is_registered(chpid))
 453                 return 0;
 454         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 455         if (!chp)
 456                 return -ENOMEM;
 457
 458         /* fill in status, etc. */
 459         chp->chpid = chpid;
 460         chp->state = 1;
 461         chp->dev.parent = &css->device;
 462         chp->dev.groups = chp_attr_groups;
 463         chp->dev.release = chp_release;
 464         mutex_init(&chp->lock);
 465
 466         /* Obtain channel path description and fill it in. */
 467         ret = chp_update_desc(chp);
 468         if (ret)
 469                 goto out_free;
 470         if ((chp->desc.flags & 0x80) == 0) {
 471                 ret = -ENODEV;
 472                 goto out_free;
 473         }
 474         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 475
 476         /* make it known to the system */
 477         ret = device_register(&chp->dev);
 478         if (ret) {
 479                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 480                               chpid.cssid, chpid.id, ret);
 481                 put_device(&chp->dev);
 482                 goto out;
 483         }
 484         mutex_lock(&css->mutex);
 485         if (css->cm_enabled) {
 486                 ret = chp_add_cmg_attr(chp);
 487                 if (ret) {
 488                         device_unregister(&chp->dev);
 489                         mutex_unlock(&css->mutex);
 490                         goto out;
 491                 }
 492         }
 493         css->chps[chpid.id] = chp;
 494         mutex_unlock(&css->mutex);
 495         goto out;
 496 out_free:
 497         kfree(chp);
 498 out:
 499         return ret;
 500 }
 501
 502 /**
 503  * chp_get_chp_desc - return newly allocated channel-path description
 504  * @chpid: channel-path ID
 505  *
 506  * On success return a newly allocated copy of the channel-path description
 507  * data associated with the given channel-path ID. Return %NULL on error.
 508  */
 509 struct channel_path_desc *chp_get_chp_desc(struct chp_id chpid)
 510 {
 511         struct channel_path *chp;
 512         struct channel_path_desc *desc;
 513
 514         chp = chpid_to_chp(chpid);
 515         if (!chp)
 516                 return NULL;
 517         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
 518         if (!desc)
 519                 return NULL;
 520
 521         mutex_lock(&chp->lock);
 522         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
 523         mutex_unlock(&chp->lock);
 524         return desc;
 525 }
 526
 527 /**
 528  * chp_process_crw - process channel-path status change
 529  * @crw0: channel report-word to handler
 530  * @crw1: second channel-report word (always NULL)
 531  * @overflow: crw overflow indication
 532  *
 533  * Handle channel-report-words indicating that the status of a channel-path
 534  * has changed.
 535  */
 536 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 537                             int overflow)
 538 {
 539         struct chp_id chpid;
 540
 541         if (overflow) {
 542                 css_schedule_eval_all();
 543                 return;
 544         }
 545         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 546                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 547                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 548                       crw0->erc, crw0->rsid);
 549         /*
 550          * Check for solicited machine checks. These are
 551          * created by reset channel path and need not be
 552          * handled here.
 553          */
 554         if (crw0->slct) {
 555                 CIO_CRW_EVENT(2, "solicited machine check for "
 556                               "channel path %02X\n", crw0->rsid);
 557                 return;
 558         }
 559         chp_id_init(&chpid);
 560         chpid.id = crw0->rsid;
 561         switch (crw0->erc) {
 562         case CRW_ERC_IPARM: /* Path has come. */
 563         case CRW_ERC_INIT:
 564                 if (!chp_is_registered(chpid))
 565                         chp_new(chpid);
 566                 chsc_chp_online(chpid);
 567                 break;
 568         case CRW_ERC_PERRI: /* Path has gone. */
 569         case CRW_ERC_PERRN:
 570                 chsc_chp_offline(chpid);
 571                 break;
 572         default:
 573                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 574                               crw0->erc);
 575         }
 576 }
 577
 578 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 579 {
 580         int i;
 581         int mask;
 582
 583         for (i = 0; i < 8; i++) {
 584                 mask = 0x80 >> i;
 585                 if (!(ssd->path_mask & mask))
 586                         continue;
 587                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 588                         continue;
 589                 if ((ssd->fla_valid_mask & mask) &&
 590                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 591                         continue;
 592                 return mask;
 593         }
 594         return 0;
 595 }
 596 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 597
 598 static inline int info_bit_num(struct chp_id id)
 599 {
 600         return id.id + id.cssid * (__MAX_CHPID + 1);
 601 }
 602
 603 /* Force chp_info refresh on next call to info_validate(). */
 604 static void info_expire(void)
 605 {
 606         mutex_lock(&info_lock);
 607         chp_info_expires = jiffies - 1;
 608         mutex_unlock(&info_lock);
 609 }
 610
 611 /* Ensure that chp_info is up-to-date. */
 612 static int info_update(void)
 613 {
 614         int rc;
 615
 616         mutex_lock(&info_lock);
 617         rc = 0;
 618         if (time_after(jiffies, chp_info_expires)) {
 619                 /* Data is too old, update. */
 620                 rc = sclp_chp_read_info(&chp_info);
 621                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 622         }
 623         mutex_unlock(&info_lock);
 624
 625         return rc;
 626 }
 627
 628 /**
 629  * chp_info_get_status - retrieve configure status of a channel-path
 630  * @chpid: channel-path ID
 631  *
 632  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 633  * 3 for not recognized. Return negative error code on error.
 634  */
 635 int chp_info_get_status(struct chp_id chpid)
 636 {
 637         int rc;
 638         int bit;
 639
 640         rc = info_update();
 641         if (rc)
 642                 return rc;
 643
 644         bit = info_bit_num(chpid);
 645         mutex_lock(&info_lock);
 646         if (!chp_test_bit(chp_info.recognized, bit))
 647                 rc = CHP_STATUS_NOT_RECOGNIZED;
 648         else if (chp_test_bit(chp_info.configured, bit))
 649                 rc = CHP_STATUS_CONFIGURED;
 650         else if (chp_test_bit(chp_info.standby, bit))
 651                 rc = CHP_STATUS_STANDBY;
 652         else
 653                 rc = CHP_STATUS_RESERVED;
 654         mutex_unlock(&info_lock);
 655
 656         return rc;
 657 }
 658
 659 /* Return configure task for chpid. */
 660 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 661 {
 662         return chp_cfg_task[chpid.cssid][chpid.id];
 663 }
 664
 665 /* Set configure task for chpid. */
 666 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 667 {
 668         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 669 }
 670
 671 /* Fetch the first configure task. Set chpid accordingly. */
 672 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
 673 {
 674         enum cfg_task_t t = cfg_none;
 675
 676         chp_id_for_each(chpid) {
 677                 t = cfg_get_task(*chpid);
 678                 if (t != cfg_none)
 679                         break;
 680         }
 681
 682         return t;
 683 }
 684
 685 /* Perform one configure/deconfigure request. Reschedule work function until
 686  * last request. */
 687 static void cfg_func(struct work_struct *work)
 688 {
 689         struct chp_id chpid;
 690         enum cfg_task_t t;
 691         int rc;
 692
 693         spin_lock(&cfg_lock);
 694         t = chp_cfg_fetch_task(&chpid);
 695         spin_unlock(&cfg_lock);
 696
 697         switch (t) {
 698         case cfg_configure:
 699                 rc = sclp_chp_configure(chpid);
 700                 if (rc)
 701                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 702                                       "%d\n", chpid.cssid, chpid.id, rc);
 703                 else {
 704                         info_expire();
 705                         chsc_chp_online(chpid);
 706                 }
 707                 break;
 708         case cfg_deconfigure:
 709                 rc = sclp_chp_deconfigure(chpid);
 710                 if (rc)
 711                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 712                                       "%d\n", chpid.cssid, chpid.id, rc);
 713                 else {
 714                         info_expire();
 715                         chsc_chp_offline(chpid);
 716                 }
 717                 break;
 718         case cfg_none:
 719                 /* Get updated information after last change. */
 720                 info_update();
 721                 wake_up_interruptible(&cfg_wait_queue);
 722                 return;
 723         }
 724         spin_lock(&cfg_lock);
 725         if (t == cfg_get_task(chpid))
 726                 cfg_set_task(chpid, cfg_none);
 727         spin_unlock(&cfg_lock);
 728         schedule_work(&cfg_work);
 729 }
 730
 731 /**
 732  * chp_cfg_schedule - schedule chpid configuration request
 733  * @chpid - channel-path ID
 734  * @configure - Non-zero for configure, zero for deconfigure
 735  *
 736  * Schedule a channel-path configuration/deconfiguration request.
 737  */
 738 void chp_cfg_schedule(struct chp_id chpid, int configure)
 739 {
 740         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 741                       configure);
 742         spin_lock(&cfg_lock);
 743         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 744         spin_unlock(&cfg_lock);
 745         schedule_work(&cfg_work);
 746 }
 747
 748 /**
 749  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 750  * @chpid - channel-path ID
 751  *
 752  * Cancel an active channel-path deconfiguration request if it has not yet
 753  * been performed.
 754  */
 755 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 756 {
 757         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 758         spin_lock(&cfg_lock);
 759         if (cfg_get_task(chpid) == cfg_deconfigure)
 760                 cfg_set_task(chpid, cfg_none);
 761         spin_unlock(&cfg_lock);
 762 }
 763
 764 static bool cfg_idle(void)
 765 {
 766         struct chp_id chpid;
 767         enum cfg_task_t t;
 768
 769         spin_lock(&cfg_lock);
 770         t = chp_cfg_fetch_task(&chpid);
 771         spin_unlock(&cfg_lock);
 772
 773         return t == cfg_none;
 774 }
 775
 776 static int cfg_wait_idle(void)
 777 {
 778         if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
 779                 return -ERESTARTSYS;
 780         return 0;
 781 }
 782
 783 static int __init chp_init(void)
 784 {
 785         struct chp_id chpid;
 786         int state, ret;
 787
 788         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 789         if (ret)
 790                 return ret;
 791         INIT_WORK(&cfg_work, cfg_func);
 792         init_waitqueue_head(&cfg_wait_queue);
 793         if (info_update())
 794                 return 0;
 795         /* Register available channel-paths. */
 796         chp_id_for_each(&chpid) {
 797                 state = chp_info_get_status(chpid);
 798                 if (state == CHP_STATUS_CONFIGURED ||
 799                     state == CHP_STATUS_STANDBY)
 800                         chp_new(chpid);
 801         }
 802
 803         return 0;
 804 }
 805
 806 subsys_initcall(chp_init);