drivers/s390/cio/chp.c

   1 /*
   2  *    Copyright IBM Corp. 1999, 2010
   3  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
   4  *               Arnd Bergmann (arndb@de.ibm.com)
   5  *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   6  */
   7
   8 #include <linux/bug.h>
   9 #include <linux/workqueue.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/export.h>
  12 #include <linux/sched.h>
  13 #include <linux/init.h>
  14 #include <linux/jiffies.h>
  15 #include <linux/wait.h>
  16 #include <linux/mutex.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <asm/chpid.h>
  20 #include <asm/sclp.h>
  21 #include <asm/crw.h>
  22
  23 #include "cio.h"
  24 #include "css.h"
  25 #include "ioasm.h"
  26 #include "cio_debug.h"
  27 #include "chp.h"
  28
  29 #define to_channelpath(device) container_of(device, struct channel_path, dev)
  30 #define CHP_INFO_UPDATE_INTERVAL        1*HZ
  31
  32 enum cfg_task_t {
  33         cfg_none,
  34         cfg_configure,
  35         cfg_deconfigure
  36 };
  37
  38 /* Map for pending configure tasks. */
  39 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
  40 static DEFINE_MUTEX(cfg_lock);
  41 static int cfg_busy;
  42
  43 /* Map for channel-path status. */
  44 static struct sclp_chp_info chp_info;
  45 static DEFINE_MUTEX(info_lock);
  46
  47 /* Time after which channel-path status may be outdated. */
  48 static unsigned long chp_info_expires;
  49
  50 /* Workqueue to perform pending configure tasks. */
  51 static struct workqueue_struct *chp_wq;
  52 static struct work_struct cfg_work;
  53
  54 /* Wait queue for configure completion events. */
  55 static wait_queue_head_t cfg_wait_queue;
  56
  57 /* Set vary state for given chpid. */
  58 static void set_chp_logically_online(struct chp_id chpid, int onoff)
  59 {
  60         chpid_to_chp(chpid)->state = onoff;
  61 }
  62
  63 /* On success return 0 if channel-path is varied offline, 1 if it is varied
  64  * online. Return -ENODEV if channel-path is not registered. */
  65 int chp_get_status(struct chp_id chpid)
  66 {
  67         return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
  68 }
  69
  70 /**
  71  * chp_get_sch_opm - return opm for subchannel
  72  * @sch: subchannel
  73  *
  74  * Calculate and return the operational path mask (opm) based on the chpids
  75  * used by the subchannel and the status of the associated channel-paths.
  76  */
  77 u8 chp_get_sch_opm(struct subchannel *sch)
  78 {
  79         struct chp_id chpid;
  80         int opm;
  81         int i;
  82
  83         opm = 0;
  84         chp_id_init(&chpid);
  85         for (i = 0; i < 8; i++) {
  86                 opm <<= 1;
  87                 chpid.id = sch->schib.pmcw.chpid[i];
  88                 if (chp_get_status(chpid) != 0)
  89                         opm |= 1;
  90         }
  91         return opm;
  92 }
  93 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
  94
  95 /**
  96  * chp_is_registered - check if a channel-path is registered
  97  * @chpid: channel-path ID
  98  *
  99  * Return non-zero if a channel-path with the given chpid is registered,
 100  * zero otherwise.
 101  */
 102 int chp_is_registered(struct chp_id chpid)
 103 {
 104         return chpid_to_chp(chpid) != NULL;
 105 }
 106
 107 /*
 108  * Function: s390_vary_chpid
 109  * Varies the specified chpid online or offline
 110  */
 111 static int s390_vary_chpid(struct chp_id chpid, int on)
 112 {
 113         char dbf_text[15];
 114         int status;
 115
 116         sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
 117                 chpid.id);
 118         CIO_TRACE_EVENT(2, dbf_text);
 119
 120         status = chp_get_status(chpid);
 121         if (!on && !status)
 122                 return 0;
 123
 124         set_chp_logically_online(chpid, on);
 125         chsc_chp_vary(chpid, on);
 126         return 0;
 127 }
 128
 129 /*
 130  * Channel measurement related functions
 131  */
 132 static ssize_t chp_measurement_chars_read(struct file *filp,
 133                                           struct kobject *kobj,
 134                                           struct bin_attribute *bin_attr,
 135                                           char *buf, loff_t off, size_t count)
 136 {
 137         struct channel_path *chp;
 138         struct device *device;
 139
 140         device = container_of(kobj, struct device, kobj);
 141         chp = to_channelpath(device);
 142         if (chp->cmg == -1)
 143                 return 0;
 144
 145         return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
 146                                        sizeof(chp->cmg_chars));
 147 }
 148
 149 static struct bin_attribute chp_measurement_chars_attr = {
 150         .attr = {
 151                 .name = "measurement_chars",
 152                 .mode = S_IRUSR,
 153         },
 154         .size = sizeof(struct cmg_chars),
 155         .read = chp_measurement_chars_read,
 156 };
 157
 158 static void chp_measurement_copy_block(struct cmg_entry *buf,
 159                                        struct channel_subsystem *css,
 160                                        struct chp_id chpid)
 161 {
 162         void *area;
 163         struct cmg_entry *entry, reference_buf;
 164         int idx;
 165
 166         if (chpid.id < 128) {
 167                 area = css->cub_addr1;
 168                 idx = chpid.id;
 169         } else {
 170                 area = css->cub_addr2;
 171                 idx = chpid.id - 128;
 172         }
 173         entry = area + (idx * sizeof(struct cmg_entry));
 174         do {
 175                 memcpy(buf, entry, sizeof(*entry));
 176                 memcpy(&reference_buf, entry, sizeof(*entry));
 177         } while (reference_buf.values[0] != buf->values[0]);
 178 }
 179
 180 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
 181                                     struct bin_attribute *bin_attr,
 182                                     char *buf, loff_t off, size_t count)
 183 {
 184         struct channel_path *chp;
 185         struct channel_subsystem *css;
 186         struct device *device;
 187         unsigned int size;
 188
 189         device = container_of(kobj, struct device, kobj);
 190         chp = to_channelpath(device);
 191         css = to_css(chp->dev.parent);
 192
 193         size = sizeof(struct cmg_entry);
 194
 195         /* Only allow single reads. */
 196         if (off || count < size)
 197                 return 0;
 198         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
 199         count = size;
 200         return count;
 201 }
 202
 203 static struct bin_attribute chp_measurement_attr = {
 204         .attr = {
 205                 .name = "measurement",
 206                 .mode = S_IRUSR,
 207         },
 208         .size = sizeof(struct cmg_entry),
 209         .read = chp_measurement_read,
 210 };
 211
 212 void chp_remove_cmg_attr(struct channel_path *chp)
 213 {
 214         device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 215         device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 216 }
 217
 218 int chp_add_cmg_attr(struct channel_path *chp)
 219 {
 220         int ret;
 221
 222         ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 223         if (ret)
 224                 return ret;
 225         ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 226         if (ret)
 227                 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 228         return ret;
 229 }
 230
 231 /*
 232  * Files for the channel path entries.
 233  */
 234 static ssize_t chp_status_show(struct device *dev,
 235                                struct device_attribute *attr, char *buf)
 236 {
 237         struct channel_path *chp = to_channelpath(dev);
 238         int status;
 239
 240         mutex_lock(&chp->lock);
 241         status = chp->state;
 242         mutex_unlock(&chp->lock);
 243
 244         return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
 245 }
 246
 247 static ssize_t chp_status_write(struct device *dev,
 248                                 struct device_attribute *attr,
 249                                 const char *buf, size_t count)
 250 {
 251         struct channel_path *cp = to_channelpath(dev);
 252         char cmd[10];
 253         int num_args;
 254         int error;
 255
 256         num_args = sscanf(buf, "%5s", cmd);
 257         if (!num_args)
 258                 return count;
 259
 260         if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
 261                 mutex_lock(&cp->lock);
 262                 error = s390_vary_chpid(cp->chpid, 1);
 263                 mutex_unlock(&cp->lock);
 264         } else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
 265                 mutex_lock(&cp->lock);
 266                 error = s390_vary_chpid(cp->chpid, 0);
 267                 mutex_unlock(&cp->lock);
 268         } else
 269                 error = -EINVAL;
 270
 271         return error < 0 ? error : count;
 272 }
 273
 274 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 275
 276 static ssize_t chp_configure_show(struct device *dev,
 277                                   struct device_attribute *attr, char *buf)
 278 {
 279         struct channel_path *cp;
 280         int status;
 281
 282         cp = to_channelpath(dev);
 283         status = chp_info_get_status(cp->chpid);
 284         if (status < 0)
 285                 return status;
 286
 287         return snprintf(buf, PAGE_SIZE, "%d\n", status);
 288 }
 289
 290 static int cfg_wait_idle(void);
 291
 292 static ssize_t chp_configure_write(struct device *dev,
 293                                    struct device_attribute *attr,
 294                                    const char *buf, size_t count)
 295 {
 296         struct channel_path *cp;
 297         int val;
 298         char delim;
 299
 300         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 301                 return -EINVAL;
 302         if (val != 0 && val != 1)
 303                 return -EINVAL;
 304         cp = to_channelpath(dev);
 305         chp_cfg_schedule(cp->chpid, val);
 306         cfg_wait_idle();
 307
 308         return count;
 309 }
 310
 311 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 312
 313 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
 314                              char *buf)
 315 {
 316         struct channel_path *chp = to_channelpath(dev);
 317         u8 type;
 318
 319         mutex_lock(&chp->lock);
 320         type = chp->desc.desc;
 321         mutex_unlock(&chp->lock);
 322         return sprintf(buf, "%x\n", type);
 323 }
 324
 325 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 326
 327 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
 328                             char *buf)
 329 {
 330         struct channel_path *chp = to_channelpath(dev);
 331
 332         if (!chp)
 333                 return 0;
 334         if (chp->cmg == -1) /* channel measurements not available */
 335                 return sprintf(buf, "unknown\n");
 336         return sprintf(buf, "%x\n", chp->cmg);
 337 }
 338
 339 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 340
 341 static ssize_t chp_shared_show(struct device *dev,
 342                                struct device_attribute *attr, char *buf)
 343 {
 344         struct channel_path *chp = to_channelpath(dev);
 345
 346         if (!chp)
 347                 return 0;
 348         if (chp->shared == -1) /* channel measurements not available */
 349                 return sprintf(buf, "unknown\n");
 350         return sprintf(buf, "%x\n", chp->shared);
 351 }
 352
 353 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 354
 355 static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
 356                              char *buf)
 357 {
 358         struct channel_path *chp = to_channelpath(dev);
 359         ssize_t rc;
 360
 361         mutex_lock(&chp->lock);
 362         if (chp->desc_fmt1.flags & 0x10)
 363                 rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid);
 364         else
 365                 rc = 0;
 366         mutex_unlock(&chp->lock);
 367
 368         return rc;
 369 }
 370 static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
 371
 372 static ssize_t chp_chid_external_show(struct device *dev,
 373                                       struct device_attribute *attr, char *buf)
 374 {
 375         struct channel_path *chp = to_channelpath(dev);
 376         ssize_t rc;
 377
 378         mutex_lock(&chp->lock);
 379         if (chp->desc_fmt1.flags & 0x10)
 380                 rc = sprintf(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
 381         else
 382                 rc = 0;
 383         mutex_unlock(&chp->lock);
 384
 385         return rc;
 386 }
 387 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
 388
 389 static struct attribute *chp_attrs[] = {
 390         &dev_attr_status.attr,
 391         &dev_attr_configure.attr,
 392         &dev_attr_type.attr,
 393         &dev_attr_cmg.attr,
 394         &dev_attr_shared.attr,
 395         &dev_attr_chid.attr,
 396         &dev_attr_chid_external.attr,
 397         NULL,
 398 };
 399 static struct attribute_group chp_attr_group = {
 400         .attrs = chp_attrs,
 401 };
 402 static const struct attribute_group *chp_attr_groups[] = {
 403         &chp_attr_group,
 404         NULL,
 405 };
 406
 407 static void chp_release(struct device *dev)
 408 {
 409         struct channel_path *cp;
 410
 411         cp = to_channelpath(dev);
 412         kfree(cp);
 413 }
 414
 415 /**
 416  * chp_update_desc - update channel-path description
 417  * @chp - channel-path
 418  *
 419  * Update the channel-path description of the specified channel-path
 420  * including channel measurement related information.
 421  * Return zero on success, non-zero otherwise.
 422  */
 423 int chp_update_desc(struct channel_path *chp)
 424 {
 425         int rc;
 426
 427         rc = chsc_determine_base_channel_path_desc(chp->chpid, &chp->desc);
 428         if (rc)
 429                 return rc;
 430
 431         rc = chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
 432         if (rc)
 433                 return rc;
 434
 435         return chsc_get_channel_measurement_chars(chp);
 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_path *chp;
 448         int ret;
 449
 450         if (chp_is_registered(chpid))
 451                 return 0;
 452         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 453         if (!chp)
 454                 return -ENOMEM;
 455
 456         /* fill in status, etc. */
 457         chp->chpid = chpid;
 458         chp->state = 1;
 459         chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
 460         chp->dev.groups = chp_attr_groups;
 461         chp->dev.release = chp_release;
 462         mutex_init(&chp->lock);
 463
 464         /* Obtain channel path description and fill it in. */
 465         ret = chp_update_desc(chp);
 466         if (ret)
 467                 goto out_free;
 468         if ((chp->desc.flags & 0x80) == 0) {
 469                 ret = -ENODEV;
 470                 goto out_free;
 471         }
 472         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 473
 474         /* make it known to the system */
 475         ret = device_register(&chp->dev);
 476         if (ret) {
 477                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 478                               chpid.cssid, chpid.id, ret);
 479                 put_device(&chp->dev);
 480                 goto out;
 481         }
 482         mutex_lock(&channel_subsystems[chpid.cssid]->mutex);
 483         if (channel_subsystems[chpid.cssid]->cm_enabled) {
 484                 ret = chp_add_cmg_attr(chp);
 485                 if (ret) {
 486                         device_unregister(&chp->dev);
 487                         mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
 488                         goto out;
 489                 }
 490         }
 491         channel_subsystems[chpid.cssid]->chps[chpid.id] = chp;
 492         mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
 493         goto out;
 494 out_free:
 495         kfree(chp);
 496 out:
 497         return ret;
 498 }
 499
 500 /**
 501  * chp_get_chp_desc - return newly allocated channel-path description
 502  * @chpid: channel-path ID
 503  *
 504  * On success return a newly allocated copy of the channel-path description
 505  * data associated with the given channel-path ID. Return %NULL on error.
 506  */
 507 struct channel_path_desc *chp_get_chp_desc(struct chp_id chpid)
 508 {
 509         struct channel_path *chp;
 510         struct channel_path_desc *desc;
 511
 512         chp = chpid_to_chp(chpid);
 513         if (!chp)
 514                 return NULL;
 515         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
 516         if (!desc)
 517                 return NULL;
 518
 519         mutex_lock(&chp->lock);
 520         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
 521         mutex_unlock(&chp->lock);
 522         return desc;
 523 }
 524
 525 /**
 526  * chp_process_crw - process channel-path status change
 527  * @crw0: channel report-word to handler
 528  * @crw1: second channel-report word (always NULL)
 529  * @overflow: crw overflow indication
 530  *
 531  * Handle channel-report-words indicating that the status of a channel-path
 532  * has changed.
 533  */
 534 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 535                             int overflow)
 536 {
 537         struct chp_id chpid;
 538
 539         if (overflow) {
 540                 css_schedule_eval_all();
 541                 return;
 542         }
 543         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 544                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 545                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 546                       crw0->erc, crw0->rsid);
 547         /*
 548          * Check for solicited machine checks. These are
 549          * created by reset channel path and need not be
 550          * handled here.
 551          */
 552         if (crw0->slct) {
 553                 CIO_CRW_EVENT(2, "solicited machine check for "
 554                               "channel path %02X\n", crw0->rsid);
 555                 return;
 556         }
 557         chp_id_init(&chpid);
 558         chpid.id = crw0->rsid;
 559         switch (crw0->erc) {
 560         case CRW_ERC_IPARM: /* Path has come. */
 561                 if (!chp_is_registered(chpid))
 562                         chp_new(chpid);
 563                 chsc_chp_online(chpid);
 564                 break;
 565         case CRW_ERC_PERRI: /* Path has gone. */
 566         case CRW_ERC_PERRN:
 567                 chsc_chp_offline(chpid);
 568                 break;
 569         default:
 570                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 571                               crw0->erc);
 572         }
 573 }
 574
 575 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 576 {
 577         int i;
 578         int mask;
 579
 580         for (i = 0; i < 8; i++) {
 581                 mask = 0x80 >> i;
 582                 if (!(ssd->path_mask & mask))
 583                         continue;
 584                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 585                         continue;
 586                 if ((ssd->fla_valid_mask & mask) &&
 587                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 588                         continue;
 589                 return mask;
 590         }
 591         return 0;
 592 }
 593 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 594
 595 static inline int info_bit_num(struct chp_id id)
 596 {
 597         return id.id + id.cssid * (__MAX_CHPID + 1);
 598 }
 599
 600 /* Force chp_info refresh on next call to info_validate(). */
 601 static void info_expire(void)
 602 {
 603         mutex_lock(&info_lock);
 604         chp_info_expires = jiffies - 1;
 605         mutex_unlock(&info_lock);
 606 }
 607
 608 /* Ensure that chp_info is up-to-date. */
 609 static int info_update(void)
 610 {
 611         int rc;
 612
 613         mutex_lock(&info_lock);
 614         rc = 0;
 615         if (time_after(jiffies, chp_info_expires)) {
 616                 /* Data is too old, update. */
 617                 rc = sclp_chp_read_info(&chp_info);
 618                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 619         }
 620         mutex_unlock(&info_lock);
 621
 622         return rc;
 623 }
 624
 625 /**
 626  * chp_info_get_status - retrieve configure status of a channel-path
 627  * @chpid: channel-path ID
 628  *
 629  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 630  * 3 for not recognized. Return negative error code on error.
 631  */
 632 int chp_info_get_status(struct chp_id chpid)
 633 {
 634         int rc;
 635         int bit;
 636
 637         rc = info_update();
 638         if (rc)
 639                 return rc;
 640
 641         bit = info_bit_num(chpid);
 642         mutex_lock(&info_lock);
 643         if (!chp_test_bit(chp_info.recognized, bit))
 644                 rc = CHP_STATUS_NOT_RECOGNIZED;
 645         else if (chp_test_bit(chp_info.configured, bit))
 646                 rc = CHP_STATUS_CONFIGURED;
 647         else if (chp_test_bit(chp_info.standby, bit))
 648                 rc = CHP_STATUS_STANDBY;
 649         else
 650                 rc = CHP_STATUS_RESERVED;
 651         mutex_unlock(&info_lock);
 652
 653         return rc;
 654 }
 655
 656 /* Return configure task for chpid. */
 657 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 658 {
 659         return chp_cfg_task[chpid.cssid][chpid.id];
 660 }
 661
 662 /* Set configure task for chpid. */
 663 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 664 {
 665         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 666 }
 667
 668 /* Perform one configure/deconfigure request. Reschedule work function until
 669  * last request. */
 670 static void cfg_func(struct work_struct *work)
 671 {
 672         struct chp_id chpid;
 673         enum cfg_task_t t;
 674         int rc;
 675
 676         mutex_lock(&cfg_lock);
 677         t = cfg_none;
 678         chp_id_for_each(&chpid) {
 679                 t = cfg_get_task(chpid);
 680                 if (t != cfg_none) {
 681                         cfg_set_task(chpid, cfg_none);
 682                         break;
 683                 }
 684         }
 685         mutex_unlock(&cfg_lock);
 686
 687         switch (t) {
 688         case cfg_configure:
 689                 rc = sclp_chp_configure(chpid);
 690                 if (rc)
 691                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 692                                       "%d\n", chpid.cssid, chpid.id, rc);
 693                 else {
 694                         info_expire();
 695                         chsc_chp_online(chpid);
 696                 }
 697                 break;
 698         case cfg_deconfigure:
 699                 rc = sclp_chp_deconfigure(chpid);
 700                 if (rc)
 701                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 702                                       "%d\n", chpid.cssid, chpid.id, rc);
 703                 else {
 704                         info_expire();
 705                         chsc_chp_offline(chpid);
 706                 }
 707                 break;
 708         case cfg_none:
 709                 /* Get updated information after last change. */
 710                 info_update();
 711                 mutex_lock(&cfg_lock);
 712                 cfg_busy = 0;
 713                 mutex_unlock(&cfg_lock);
 714                 wake_up_interruptible(&cfg_wait_queue);
 715                 return;
 716         }
 717         queue_work(chp_wq, &cfg_work);
 718 }
 719
 720 /**
 721  * chp_cfg_schedule - schedule chpid configuration request
 722  * @chpid - channel-path ID
 723  * @configure - Non-zero for configure, zero for deconfigure
 724  *
 725  * Schedule a channel-path configuration/deconfiguration request.
 726  */
 727 void chp_cfg_schedule(struct chp_id chpid, int configure)
 728 {
 729         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 730                       configure);
 731         mutex_lock(&cfg_lock);
 732         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 733         cfg_busy = 1;
 734         mutex_unlock(&cfg_lock);
 735         queue_work(chp_wq, &cfg_work);
 736 }
 737
 738 /**
 739  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 740  * @chpid - channel-path ID
 741  *
 742  * Cancel an active channel-path deconfiguration request if it has not yet
 743  * been performed.
 744  */
 745 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 746 {
 747         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 748         mutex_lock(&cfg_lock);
 749         if (cfg_get_task(chpid) == cfg_deconfigure)
 750                 cfg_set_task(chpid, cfg_none);
 751         mutex_unlock(&cfg_lock);
 752 }
 753
 754 static int cfg_wait_idle(void)
 755 {
 756         if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
 757                 return -ERESTARTSYS;
 758         return 0;
 759 }
 760
 761 static int __init chp_init(void)
 762 {
 763         struct chp_id chpid;
 764         int ret;
 765
 766         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 767         if (ret)
 768                 return ret;
 769         chp_wq = create_singlethread_workqueue("cio_chp");
 770         if (!chp_wq) {
 771                 crw_unregister_handler(CRW_RSC_CPATH);
 772                 return -ENOMEM;
 773         }
 774         INIT_WORK(&cfg_work, cfg_func);
 775         init_waitqueue_head(&cfg_wait_queue);
 776         if (info_update())
 777                 return 0;
 778         /* Register available channel-paths. */
 779         chp_id_for_each(&chpid) {
 780                 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
 781                         chp_new(chpid);
 782         }
 783
 784         return 0;
 785 }
 786
 787 subsys_initcall(chp_init);