root/drivers/s390/cio/chp.c

DEFINITIONS

1. set_chp_logically_online
2. chp_get_status
3. chp_get_sch_opm
4. chp_is_registered
5. s390_vary_chpid
6. chp_measurement_chars_read
7. chp_measurement_copy_block
8. chp_measurement_read
9. chp_remove_cmg_attr
10. chp_add_cmg_attr
11. chp_status_show
12. chp_status_write
13. chp_configure_show
14. chp_configure_write
15. chp_type_show
16. chp_cmg_show
17. chp_shared_show
18. chp_chid_show
19. chp_chid_external_show
20. util_string_read
21. chp_release
22. chp_update_desc
23. chp_new
24. chp_get_chp_desc
25. chp_process_crw
26. chp_ssd_get_mask
27. info_bit_num
28. info_expire
29. info_update
30. chp_info_get_status
31. cfg_get_task
32. cfg_set_task
33. chp_cfg_fetch_task
34. cfg_func
35. chp_cfg_schedule
36. chp_cfg_cancel_deconfigure
37. cfg_idle
38. cfg_wait_idle
39. chp_init

   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  47 /* Time after which channel-path status may be outdated.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 ssize_t util_string_read(struct file *filp, struct kobject *kobj,
 388                                 struct bin_attribute *attr, char *buf,
 389                                 loff_t off, size_t count)
 390 {
 391         struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
 392         ssize_t rc;
 393 
 394         mutex_lock(&chp->lock);
 395         rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
 396                                      sizeof(chp->desc_fmt3.util_str));
 397         mutex_unlock(&chp->lock);
 398 
 399         return rc;
 400 }
 401 static BIN_ATTR_RO(util_string,
 402                    sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
 403 
 404 static struct bin_attribute *chp_bin_attrs[] = {
 405         &bin_attr_util_string,
 406         NULL,
 407 };
 408 
 409 static struct attribute *chp_attrs[] = {
 410         &dev_attr_status.attr,
 411         &dev_attr_configure.attr,
 412         &dev_attr_type.attr,
 413         &dev_attr_cmg.attr,
 414         &dev_attr_shared.attr,
 415         &dev_attr_chid.attr,
 416         &dev_attr_chid_external.attr,
 417         NULL,
 418 };
 419 static struct attribute_group chp_attr_group = {
 420         .attrs = chp_attrs,
 421         .bin_attrs = chp_bin_attrs,
 422 };
 423 static const struct attribute_group *chp_attr_groups[] = {
 424         &chp_attr_group,
 425         NULL,
 426 };
 427 
 428 static void chp_release(struct device *dev)
 429 {
 430         struct channel_path *cp;
 431 
 432         cp = to_channelpath(dev);
 433         kfree(cp);
 434 }
 435 
 436 /**
 437  * chp_update_desc - update channel-path description
 438  * @chp: channel-path
 439  *
 440  * Update the channel-path description of the specified channel-path
 441  * including channel measurement related information.
 442  * Return zero on success, non-zero otherwise.
 443  */
 444 int chp_update_desc(struct channel_path *chp)
 445 {
 446         int rc;
 447 
 448         rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc);
 449         if (rc)
 450                 return rc;
 451 
 452         /*
 453          * Fetching the following data is optional. Not all machines or
 454          * hypervisors implement the required chsc commands.
 455          */
 456         chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
 457         chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3);
 458         chsc_get_channel_measurement_chars(chp);
 459 
 460         return 0;
 461 }
 462 
 463 /**
 464  * chp_new - register a new channel-path
 465  * @chpid: channel-path ID
 466  *
 467  * Create and register data structure representing new channel-path. Return
 468  * zero on success, non-zero otherwise.
 469  */
 470 int chp_new(struct chp_id chpid)
 471 {
 472         struct channel_subsystem *css = css_by_id(chpid.cssid);
 473         struct channel_path *chp;
 474         int ret = 0;
 475 
 476         mutex_lock(&css->mutex);
 477         if (chp_is_registered(chpid))
 478                 goto out;
 479 
 480         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 481         if (!chp) {
 482                 ret = -ENOMEM;
 483                 goto out;
 484         }
 485         /* fill in status, etc. */
 486         chp->chpid = chpid;
 487         chp->state = 1;
 488         chp->dev.parent = &css->device;
 489         chp->dev.groups = chp_attr_groups;
 490         chp->dev.release = chp_release;
 491         mutex_init(&chp->lock);
 492 
 493         /* Obtain channel path description and fill it in. */
 494         ret = chp_update_desc(chp);
 495         if (ret)
 496                 goto out_free;
 497         if ((chp->desc.flags & 0x80) == 0) {
 498                 ret = -ENODEV;
 499                 goto out_free;
 500         }
 501         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 502 
 503         /* make it known to the system */
 504         ret = device_register(&chp->dev);
 505         if (ret) {
 506                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 507                               chpid.cssid, chpid.id, ret);
 508                 put_device(&chp->dev);
 509                 goto out;
 510         }
 511 
 512         if (css->cm_enabled) {
 513                 ret = chp_add_cmg_attr(chp);
 514                 if (ret) {
 515                         device_unregister(&chp->dev);
 516                         goto out;
 517                 }
 518         }
 519         css->chps[chpid.id] = chp;
 520         goto out;
 521 out_free:
 522         kfree(chp);
 523 out:
 524         mutex_unlock(&css->mutex);
 525         return ret;
 526 }
 527 
 528 /**
 529  * chp_get_chp_desc - return newly allocated channel-path description
 530  * @chpid: channel-path ID
 531  *
 532  * On success return a newly allocated copy of the channel-path description
 533  * data associated with the given channel-path ID. Return %NULL on error.
 534  */
 535 struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid)
 536 {
 537         struct channel_path *chp;
 538         struct channel_path_desc_fmt0 *desc;
 539 
 540         chp = chpid_to_chp(chpid);
 541         if (!chp)
 542                 return NULL;
 543         desc = kmalloc(sizeof(*desc), GFP_KERNEL);
 544         if (!desc)
 545                 return NULL;
 546 
 547         mutex_lock(&chp->lock);
 548         memcpy(desc, &chp->desc, sizeof(*desc));
 549         mutex_unlock(&chp->lock);
 550         return desc;
 551 }
 552 
 553 /**
 554  * chp_process_crw - process channel-path status change
 555  * @crw0: channel report-word to handler
 556  * @crw1: second channel-report word (always NULL)
 557  * @overflow: crw overflow indication
 558  *
 559  * Handle channel-report-words indicating that the status of a channel-path
 560  * has changed.
 561  */
 562 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 563                             int overflow)
 564 {
 565         struct chp_id chpid;
 566 
 567         if (overflow) {
 568                 css_schedule_eval_all();
 569                 return;
 570         }
 571         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 572                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 573                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 574                       crw0->erc, crw0->rsid);
 575         /*
 576          * Check for solicited machine checks. These are
 577          * created by reset channel path and need not be
 578          * handled here.
 579          */
 580         if (crw0->slct) {
 581                 CIO_CRW_EVENT(2, "solicited machine check for "
 582                               "channel path %02X\n", crw0->rsid);
 583                 return;
 584         }
 585         chp_id_init(&chpid);
 586         chpid.id = crw0->rsid;
 587         switch (crw0->erc) {
 588         case CRW_ERC_IPARM: /* Path has come. */
 589         case CRW_ERC_INIT:
 590                 chp_new(chpid);
 591                 chsc_chp_online(chpid);
 592                 break;
 593         case CRW_ERC_PERRI: /* Path has gone. */
 594         case CRW_ERC_PERRN:
 595                 chsc_chp_offline(chpid);
 596                 break;
 597         default:
 598                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 599                               crw0->erc);
 600         }
 601 }
 602 
 603 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 604 {
 605         int i;
 606         int mask;
 607 
 608         for (i = 0; i < 8; i++) {
 609                 mask = 0x80 >> i;
 610                 if (!(ssd->path_mask & mask))
 611                         continue;
 612                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 613                         continue;
 614                 if ((ssd->fla_valid_mask & mask) &&
 615                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 616                         continue;
 617                 return mask;
 618         }
 619         return 0;
 620 }
 621 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 622 
 623 static inline int info_bit_num(struct chp_id id)
 624 {
 625         return id.id + id.cssid * (__MAX_CHPID + 1);
 626 }
 627 
 628 /* Force chp_info refresh on next call to info_validate(). */
 629 static void info_expire(void)
 630 {
 631         mutex_lock(&info_lock);
 632         chp_info_expires = jiffies - 1;
 633         mutex_unlock(&info_lock);
 634 }
 635 
 636 /* Ensure that chp_info is up-to-date. */
 637 static int info_update(void)
 638 {
 639         int rc;
 640 
 641         mutex_lock(&info_lock);
 642         rc = 0;
 643         if (time_after(jiffies, chp_info_expires)) {
 644                 /* Data is too old, update. */
 645                 rc = sclp_chp_read_info(&chp_info);
 646                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 647         }
 648         mutex_unlock(&info_lock);
 649 
 650         return rc;
 651 }
 652 
 653 /**
 654  * chp_info_get_status - retrieve configure status of a channel-path
 655  * @chpid: channel-path ID
 656  *
 657  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 658  * 3 for not recognized. Return negative error code on error.
 659  */
 660 int chp_info_get_status(struct chp_id chpid)
 661 {
 662         int rc;
 663         int bit;
 664 
 665         rc = info_update();
 666         if (rc)
 667                 return rc;
 668 
 669         bit = info_bit_num(chpid);
 670         mutex_lock(&info_lock);
 671         if (!chp_test_bit(chp_info.recognized, bit))
 672                 rc = CHP_STATUS_NOT_RECOGNIZED;
 673         else if (chp_test_bit(chp_info.configured, bit))
 674                 rc = CHP_STATUS_CONFIGURED;
 675         else if (chp_test_bit(chp_info.standby, bit))
 676                 rc = CHP_STATUS_STANDBY;
 677         else
 678                 rc = CHP_STATUS_RESERVED;
 679         mutex_unlock(&info_lock);
 680 
 681         return rc;
 682 }
 683 
 684 /* Return configure task for chpid. */
 685 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 686 {
 687         return chp_cfg_task[chpid.cssid][chpid.id];
 688 }
 689 
 690 /* Set configure task for chpid. */
 691 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 692 {
 693         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 694 }
 695 
 696 /* Fetch the first configure task. Set chpid accordingly. */
 697 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
 698 {
 699         enum cfg_task_t t = cfg_none;
 700 
 701         chp_id_for_each(chpid) {
 702                 t = cfg_get_task(*chpid);
 703                 if (t != cfg_none)
 704                         break;
 705         }
 706 
 707         return t;
 708 }
 709 
 710 /* Perform one configure/deconfigure request. Reschedule work function until
 711  * last request. */
 712 static void cfg_func(struct work_struct *work)
 713 {
 714         struct chp_id chpid;
 715         enum cfg_task_t t;
 716         int rc;
 717 
 718         spin_lock(&cfg_lock);
 719         t = chp_cfg_fetch_task(&chpid);
 720         spin_unlock(&cfg_lock);
 721 
 722         switch (t) {
 723         case cfg_configure:
 724                 rc = sclp_chp_configure(chpid);
 725                 if (rc)
 726                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 727                                       "%d\n", chpid.cssid, chpid.id, rc);
 728                 else {
 729                         info_expire();
 730                         chsc_chp_online(chpid);
 731                 }
 732                 break;
 733         case cfg_deconfigure:
 734                 rc = sclp_chp_deconfigure(chpid);
 735                 if (rc)
 736                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 737                                       "%d\n", chpid.cssid, chpid.id, rc);
 738                 else {
 739                         info_expire();
 740                         chsc_chp_offline(chpid);
 741                 }
 742                 break;
 743         case cfg_none:
 744                 /* Get updated information after last change. */
 745                 info_update();
 746                 wake_up_interruptible(&cfg_wait_queue);
 747                 return;
 748         }
 749         spin_lock(&cfg_lock);
 750         if (t == cfg_get_task(chpid))
 751                 cfg_set_task(chpid, cfg_none);
 752         spin_unlock(&cfg_lock);
 753         schedule_work(&cfg_work);
 754 }
 755 
 756 /**
 757  * chp_cfg_schedule - schedule chpid configuration request
 758  * @chpid: channel-path ID
 759  * @configure: Non-zero for configure, zero for deconfigure
 760  *
 761  * Schedule a channel-path configuration/deconfiguration request.
 762  */
 763 void chp_cfg_schedule(struct chp_id chpid, int configure)
 764 {
 765         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 766                       configure);
 767         spin_lock(&cfg_lock);
 768         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 769         spin_unlock(&cfg_lock);
 770         schedule_work(&cfg_work);
 771 }
 772 
 773 /**
 774  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 775  * @chpid: channel-path ID
 776  *
 777  * Cancel an active channel-path deconfiguration request if it has not yet
 778  * been performed.
 779  */
 780 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 781 {
 782         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 783         spin_lock(&cfg_lock);
 784         if (cfg_get_task(chpid) == cfg_deconfigure)
 785                 cfg_set_task(chpid, cfg_none);
 786         spin_unlock(&cfg_lock);
 787 }
 788 
 789 static bool cfg_idle(void)
 790 {
 791         struct chp_id chpid;
 792         enum cfg_task_t t;
 793 
 794         spin_lock(&cfg_lock);
 795         t = chp_cfg_fetch_task(&chpid);
 796         spin_unlock(&cfg_lock);
 797 
 798         return t == cfg_none;
 799 }
 800 
 801 static int cfg_wait_idle(void)
 802 {
 803         if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
 804                 return -ERESTARTSYS;
 805         return 0;
 806 }
 807 
 808 static int __init chp_init(void)
 809 {
 810         struct chp_id chpid;
 811         int state, ret;
 812 
 813         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 814         if (ret)
 815                 return ret;
 816         INIT_WORK(&cfg_work, cfg_func);
 817         init_waitqueue_head(&cfg_wait_queue);
 818         if (info_update())
 819                 return 0;
 820         /* Register available channel-paths. */
 821         chp_id_for_each(&chpid) {
 822                 state = chp_info_get_status(chpid);
 823                 if (state == CHP_STATUS_CONFIGURED ||
 824                     state == CHP_STATUS_STANDBY)
 825                         chp_new(chpid);
 826         }
 827 
 828         return 0;
 829 }
 830 
 831 subsys_initcall(chp_init);