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  47 /* Time after which channel-path status may be outdated.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 = kobj_to_dev(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 = kobj_to_dev(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 chp_esc_show(struct device *dev,
 388                             struct device_attribute *attr, char *buf)
 389 {
 390         struct channel_path *chp = to_channelpath(dev);
 391         ssize_t rc;
 392
 393         mutex_lock(&chp->lock);
 394         rc = sprintf(buf, "%x\n", chp->desc_fmt1.esc);
 395         mutex_unlock(&chp->lock);
 396
 397         return rc;
 398 }
 399 static DEVICE_ATTR(esc, 0444, chp_esc_show, NULL);
 400
 401 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
 402                                 struct bin_attribute *attr, char *buf,
 403                                 loff_t off, size_t count)
 404 {
 405         struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
 406         ssize_t rc;
 407
 408         mutex_lock(&chp->lock);
 409         rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
 410                                      sizeof(chp->desc_fmt3.util_str));
 411         mutex_unlock(&chp->lock);
 412
 413         return rc;
 414 }
 415 static BIN_ATTR_RO(util_string,
 416                    sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
 417
 418 static struct bin_attribute *chp_bin_attrs[] = {
 419         &bin_attr_util_string,
 420         NULL,
 421 };
 422
 423 static struct attribute *chp_attrs[] = {
 424         &dev_attr_status.attr,
 425         &dev_attr_configure.attr,
 426         &dev_attr_type.attr,
 427         &dev_attr_cmg.attr,
 428         &dev_attr_shared.attr,
 429         &dev_attr_chid.attr,
 430         &dev_attr_chid_external.attr,
 431         &dev_attr_esc.attr,
 432         NULL,
 433 };
 434 static struct attribute_group chp_attr_group = {
 435         .attrs = chp_attrs,
 436         .bin_attrs = chp_bin_attrs,
 437 };
 438 static const struct attribute_group *chp_attr_groups[] = {
 439         &chp_attr_group,
 440         NULL,
 441 };
 442
 443 static void chp_release(struct device *dev)
 444 {
 445         struct channel_path *cp;
 446
 447         cp = to_channelpath(dev);
 448         kfree(cp);
 449 }
 450
 451 /**
 452  * chp_update_desc - update channel-path description
 453  * @chp: channel-path
 454  *
 455  * Update the channel-path description of the specified channel-path
 456  * including channel measurement related information.
 457  * Return zero on success, non-zero otherwise.
 458  */
 459 int chp_update_desc(struct channel_path *chp)
 460 {
 461         int rc;
 462
 463         rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc);
 464         if (rc)
 465                 return rc;
 466
 467         /*
 468          * Fetching the following data is optional. Not all machines or
 469          * hypervisors implement the required chsc commands.
 470          */
 471         chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
 472         chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3);
 473         chsc_get_channel_measurement_chars(chp);
 474
 475         return 0;
 476 }
 477
 478 /**
 479  * chp_new - register a new channel-path
 480  * @chpid: channel-path ID
 481  *
 482  * Create and register data structure representing new channel-path. Return
 483  * zero on success, non-zero otherwise.
 484  */
 485 int chp_new(struct chp_id chpid)
 486 {
 487         struct channel_subsystem *css = css_by_id(chpid.cssid);
 488         struct channel_path *chp;
 489         int ret = 0;
 490
 491         mutex_lock(&css->mutex);
 492         if (chp_is_registered(chpid))
 493                 goto out;
 494
 495         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 496         if (!chp) {
 497                 ret = -ENOMEM;
 498                 goto out;
 499         }
 500         /* fill in status, etc. */
 501         chp->chpid = chpid;
 502         chp->state = 1;
 503         chp->dev.parent = &css->device;
 504         chp->dev.groups = chp_attr_groups;
 505         chp->dev.release = chp_release;
 506         mutex_init(&chp->lock);
 507
 508         /* Obtain channel path description and fill it in. */
 509         ret = chp_update_desc(chp);
 510         if (ret)
 511                 goto out_free;
 512         if ((chp->desc.flags & 0x80) == 0) {
 513                 ret = -ENODEV;
 514                 goto out_free;
 515         }
 516         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 517
 518         /* make it known to the system */
 519         ret = device_register(&chp->dev);
 520         if (ret) {
 521                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 522                               chpid.cssid, chpid.id, ret);
 523                 put_device(&chp->dev);
 524                 goto out;
 525         }
 526
 527         if (css->cm_enabled) {
 528                 ret = chp_add_cmg_attr(chp);
 529                 if (ret) {
 530                         device_unregister(&chp->dev);
 531                         goto out;
 532                 }
 533         }
 534         css->chps[chpid.id] = chp;
 535         goto out;
 536 out_free:
 537         kfree(chp);
 538 out:
 539         mutex_unlock(&css->mutex);
 540         return ret;
 541 }
 542
 543 /**
 544  * chp_get_chp_desc - return newly allocated channel-path description
 545  * @chpid: channel-path ID
 546  *
 547  * On success return a newly allocated copy of the channel-path description
 548  * data associated with the given channel-path ID. Return %NULL on error.
 549  */
 550 struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid)
 551 {
 552         struct channel_path *chp;
 553         struct channel_path_desc_fmt0 *desc;
 554
 555         chp = chpid_to_chp(chpid);
 556         if (!chp)
 557                 return NULL;
 558         desc = kmalloc(sizeof(*desc), GFP_KERNEL);
 559         if (!desc)
 560                 return NULL;
 561
 562         mutex_lock(&chp->lock);
 563         memcpy(desc, &chp->desc, sizeof(*desc));
 564         mutex_unlock(&chp->lock);
 565         return desc;
 566 }
 567
 568 /**
 569  * chp_process_crw - process channel-path status change
 570  * @crw0: channel report-word to handler
 571  * @crw1: second channel-report word (always NULL)
 572  * @overflow: crw overflow indication
 573  *
 574  * Handle channel-report-words indicating that the status of a channel-path
 575  * has changed.
 576  */
 577 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 578                             int overflow)
 579 {
 580         struct chp_id chpid;
 581
 582         if (overflow) {
 583                 css_schedule_eval_all();
 584                 return;
 585         }
 586         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 587                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 588                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 589                       crw0->erc, crw0->rsid);
 590         /*
 591          * Check for solicited machine checks. These are
 592          * created by reset channel path and need not be
 593          * handled here.
 594          */
 595         if (crw0->slct) {
 596                 CIO_CRW_EVENT(2, "solicited machine check for "
 597                               "channel path %02X\n", crw0->rsid);
 598                 return;
 599         }
 600         chp_id_init(&chpid);
 601         chpid.id = crw0->rsid;
 602         switch (crw0->erc) {
 603         case CRW_ERC_IPARM: /* Path has come. */
 604         case CRW_ERC_INIT:
 605                 chp_new(chpid);
 606                 chsc_chp_online(chpid);
 607                 break;
 608         case CRW_ERC_PERRI: /* Path has gone. */
 609         case CRW_ERC_PERRN:
 610                 chsc_chp_offline(chpid);
 611                 break;
 612         default:
 613                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 614                               crw0->erc);
 615         }
 616 }
 617
 618 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 619 {
 620         int i;
 621         int mask;
 622
 623         for (i = 0; i < 8; i++) {
 624                 mask = 0x80 >> i;
 625                 if (!(ssd->path_mask & mask))
 626                         continue;
 627                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 628                         continue;
 629                 if ((ssd->fla_valid_mask & mask) &&
 630                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 631                         continue;
 632                 return mask;
 633         }
 634         return 0;
 635 }
 636 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 637
 638 static inline int info_bit_num(struct chp_id id)
 639 {
 640         return id.id + id.cssid * (__MAX_CHPID + 1);
 641 }
 642
 643 /* Force chp_info refresh on next call to info_validate(). */
 644 static void info_expire(void)
 645 {
 646         mutex_lock(&info_lock);
 647         chp_info_expires = jiffies - 1;
 648         mutex_unlock(&info_lock);
 649 }
 650
 651 /* Ensure that chp_info is up-to-date. */
 652 static int info_update(void)
 653 {
 654         int rc;
 655
 656         mutex_lock(&info_lock);
 657         rc = 0;
 658         if (time_after(jiffies, chp_info_expires)) {
 659                 /* Data is too old, update. */
 660                 rc = sclp_chp_read_info(&chp_info);
 661                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 662         }
 663         mutex_unlock(&info_lock);
 664
 665         return rc;
 666 }
 667
 668 /**
 669  * chp_info_get_status - retrieve configure status of a channel-path
 670  * @chpid: channel-path ID
 671  *
 672  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 673  * 3 for not recognized. Return negative error code on error.
 674  */
 675 int chp_info_get_status(struct chp_id chpid)
 676 {
 677         int rc;
 678         int bit;
 679
 680         rc = info_update();
 681         if (rc)
 682                 return rc;
 683
 684         bit = info_bit_num(chpid);
 685         mutex_lock(&info_lock);
 686         if (!chp_test_bit(chp_info.recognized, bit))
 687                 rc = CHP_STATUS_NOT_RECOGNIZED;
 688         else if (chp_test_bit(chp_info.configured, bit))
 689                 rc = CHP_STATUS_CONFIGURED;
 690         else if (chp_test_bit(chp_info.standby, bit))
 691                 rc = CHP_STATUS_STANDBY;
 692         else
 693                 rc = CHP_STATUS_RESERVED;
 694         mutex_unlock(&info_lock);
 695
 696         return rc;
 697 }
 698
 699 /* Return configure task for chpid. */
 700 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 701 {
 702         return chp_cfg_task[chpid.cssid][chpid.id];
 703 }
 704
 705 /* Set configure task for chpid. */
 706 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 707 {
 708         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 709 }
 710
 711 /* Fetch the first configure task. Set chpid accordingly. */
 712 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
 713 {
 714         enum cfg_task_t t = cfg_none;
 715
 716         chp_id_for_each(chpid) {
 717                 t = cfg_get_task(*chpid);
 718                 if (t != cfg_none)
 719                         break;
 720         }
 721
 722         return t;
 723 }
 724
 725 /* Perform one configure/deconfigure request. Reschedule work function until
 726  * last request. */
 727 static void cfg_func(struct work_struct *work)
 728 {
 729         struct chp_id chpid;
 730         enum cfg_task_t t;
 731         int rc;
 732
 733         spin_lock(&cfg_lock);
 734         t = chp_cfg_fetch_task(&chpid);
 735         spin_unlock(&cfg_lock);
 736
 737         switch (t) {
 738         case cfg_configure:
 739                 rc = sclp_chp_configure(chpid);
 740                 if (rc)
 741                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 742                                       "%d\n", chpid.cssid, chpid.id, rc);
 743                 else {
 744                         info_expire();
 745                         chsc_chp_online(chpid);
 746                 }
 747                 break;
 748         case cfg_deconfigure:
 749                 rc = sclp_chp_deconfigure(chpid);
 750                 if (rc)
 751                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 752                                       "%d\n", chpid.cssid, chpid.id, rc);
 753                 else {
 754                         info_expire();
 755                         chsc_chp_offline(chpid);
 756                 }
 757                 break;
 758         case cfg_none:
 759                 /* Get updated information after last change. */
 760                 info_update();
 761                 wake_up_interruptible(&cfg_wait_queue);
 762                 return;
 763         }
 764         spin_lock(&cfg_lock);
 765         if (t == cfg_get_task(chpid))
 766                 cfg_set_task(chpid, cfg_none);
 767         spin_unlock(&cfg_lock);
 768         schedule_work(&cfg_work);
 769 }
 770
 771 /**
 772  * chp_cfg_schedule - schedule chpid configuration request
 773  * @chpid: channel-path ID
 774  * @configure: Non-zero for configure, zero for deconfigure
 775  *
 776  * Schedule a channel-path configuration/deconfiguration request.
 777  */
 778 void chp_cfg_schedule(struct chp_id chpid, int configure)
 779 {
 780         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 781                       configure);
 782         spin_lock(&cfg_lock);
 783         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 784         spin_unlock(&cfg_lock);
 785         schedule_work(&cfg_work);
 786 }
 787
 788 /**
 789  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 790  * @chpid: channel-path ID
 791  *
 792  * Cancel an active channel-path deconfiguration request if it has not yet
 793  * been performed.
 794  */
 795 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 796 {
 797         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 798         spin_lock(&cfg_lock);
 799         if (cfg_get_task(chpid) == cfg_deconfigure)
 800                 cfg_set_task(chpid, cfg_none);
 801         spin_unlock(&cfg_lock);
 802 }
 803
 804 static bool cfg_idle(void)
 805 {
 806         struct chp_id chpid;
 807         enum cfg_task_t t;
 808
 809         spin_lock(&cfg_lock);
 810         t = chp_cfg_fetch_task(&chpid);
 811         spin_unlock(&cfg_lock);
 812
 813         return t == cfg_none;
 814 }
 815
 816 static int cfg_wait_idle(void)
 817 {
 818         if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
 819                 return -ERESTARTSYS;
 820         return 0;
 821 }
 822
 823 static int __init chp_init(void)
 824 {
 825         struct chp_id chpid;
 826         int state, ret;
 827
 828         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 829         if (ret)
 830                 return ret;
 831         INIT_WORK(&cfg_work, cfg_func);
 832         init_waitqueue_head(&cfg_wait_queue);
 833         if (info_update())
 834                 return 0;
 835         /* Register available channel-paths. */
 836         chp_id_for_each(&chpid) {
 837                 state = chp_info_get_status(chpid);
 838                 if (state == CHP_STATUS_CONFIGURED ||
 839                     state == CHP_STATUS_STANDBY)
 840                         chp_new(chpid);
 841         }
 842
 843         return 0;
 844 }
 845
 846 subsys_initcall(chp_init);