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  47 /* Time after which channel-path status may be outdated.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 DECLARE_WAIT_QUEUE_HEAD(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 measurement_chars_read(struct file *filp, struct kobject *kobj,
 131                                       struct bin_attribute *bin_attr,
 132                                       char *buf, loff_t off, size_t count)
 133 {
 134         struct channel_path *chp;
 135         struct device *device;
 136
 137         device = kobj_to_dev(kobj);
 138         chp = to_channelpath(device);
 139         if (chp->cmg == -1)
 140                 return 0;
 141
 142         return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
 143                                        sizeof(chp->cmg_chars));
 144 }
 145 static BIN_ATTR_ADMIN_RO(measurement_chars, sizeof(struct cmg_chars));
 146
 147 static ssize_t measurement_chars_full_read(struct file *filp,
 148                                            struct kobject *kobj,
 149                                            struct bin_attribute *bin_attr,
 150                                            char *buf, loff_t off, size_t count)
 151 {
 152         struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
 153
 154         return memory_read_from_buffer(buf, count, &off, &chp->cmcb,
 155                                        sizeof(chp->cmcb));
 156 }
 157 static BIN_ATTR_ADMIN_RO(measurement_chars_full, sizeof(struct cmg_cmcb));
 158
 159 static ssize_t chp_measurement_copy_block(void *buf, loff_t off, size_t count,
 160                                           struct kobject *kobj, bool extended)
 161 {
 162         struct channel_path *chp;
 163         struct channel_subsystem *css;
 164         struct device *device;
 165         unsigned int size;
 166         void *area, *entry;
 167         int id, idx;
 168
 169         device = kobj_to_dev(kobj);
 170         chp = to_channelpath(device);
 171         css = to_css(chp->dev.parent);
 172         id = chp->chpid.id;
 173
 174         if (extended) {
 175                 /* Check if extended measurement data is available. */
 176                 if (!chp->extended)
 177                         return 0;
 178
 179                 size = sizeof(struct cmg_ext_entry);
 180                 area = css->ecub[id / CSS_ECUES_PER_PAGE];
 181                 idx = id % CSS_ECUES_PER_PAGE;
 182         } else {
 183                 size = sizeof(struct cmg_entry);
 184                 area = css->cub[id / CSS_CUES_PER_PAGE];
 185                 idx = id % CSS_CUES_PER_PAGE;
 186         }
 187         entry = area + (idx * size);
 188
 189         /* Only allow single reads. */
 190         if (off || count < size)
 191                 return 0;
 192
 193         memcpy(buf, entry, size);
 194
 195         return size;
 196 }
 197
 198 static ssize_t measurement_read(struct file *filp, struct kobject *kobj,
 199                                 struct bin_attribute *bin_attr,
 200                                 char *buf, loff_t off, size_t count)
 201 {
 202         return chp_measurement_copy_block(buf, off, count, kobj, false);
 203 }
 204 static BIN_ATTR_ADMIN_RO(measurement, sizeof(struct cmg_entry));
 205
 206 static ssize_t ext_measurement_read(struct file *filp, struct kobject *kobj,
 207                                     struct bin_attribute *bin_attr,
 208                                     char *buf, loff_t off, size_t count)
 209 {
 210         return chp_measurement_copy_block(buf, off, count, kobj, true);
 211 }
 212 static BIN_ATTR_ADMIN_RO(ext_measurement, sizeof(struct cmg_ext_entry));
 213
 214 static struct bin_attribute *measurement_attrs[] = {
 215         &bin_attr_measurement_chars,
 216         &bin_attr_measurement_chars_full,
 217         &bin_attr_measurement,
 218         &bin_attr_ext_measurement,
 219         NULL,
 220 };
 221 BIN_ATTRIBUTE_GROUPS(measurement);
 222
 223 void chp_remove_cmg_attr(struct channel_path *chp)
 224 {
 225         device_remove_groups(&chp->dev, measurement_groups);
 226 }
 227
 228 int chp_add_cmg_attr(struct channel_path *chp)
 229 {
 230         return device_add_groups(&chp->dev, measurement_groups);
 231 }
 232
 233 /*
 234  * Files for the channel path entries.
 235  */
 236 static ssize_t chp_status_show(struct device *dev,
 237                                struct device_attribute *attr, char *buf)
 238 {
 239         struct channel_path *chp = to_channelpath(dev);
 240         int status;
 241
 242         mutex_lock(&chp->lock);
 243         status = chp->state;
 244         mutex_unlock(&chp->lock);
 245
 246         return status ? sysfs_emit(buf, "online\n") : sysfs_emit(buf, "offline\n");
 247 }
 248
 249 static ssize_t chp_status_write(struct device *dev,
 250                                 struct device_attribute *attr,
 251                                 const char *buf, size_t count)
 252 {
 253         struct channel_path *cp = to_channelpath(dev);
 254         char cmd[10];
 255         int num_args;
 256         int error;
 257
 258         num_args = sscanf(buf, "%5s", cmd);
 259         if (!num_args)
 260                 return count;
 261
 262         /* Wait until previous actions have settled. */
 263         css_wait_for_slow_path();
 264
 265         if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
 266                 mutex_lock(&cp->lock);
 267                 error = s390_vary_chpid(cp->chpid, 1);
 268                 mutex_unlock(&cp->lock);
 269         } else if (!strncasecmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
 270                 mutex_lock(&cp->lock);
 271                 error = s390_vary_chpid(cp->chpid, 0);
 272                 mutex_unlock(&cp->lock);
 273         } else
 274                 error = -EINVAL;
 275
 276         return error < 0 ? error : count;
 277 }
 278
 279 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 280
 281 static ssize_t chp_configure_show(struct device *dev,
 282                                   struct device_attribute *attr, char *buf)
 283 {
 284         struct channel_path *cp;
 285         int status;
 286
 287         cp = to_channelpath(dev);
 288         status = chp_info_get_status(cp->chpid);
 289         if (status < 0)
 290                 return status;
 291
 292         return sysfs_emit(buf, "%d\n", status);
 293 }
 294
 295 static int cfg_wait_idle(void);
 296
 297 static ssize_t chp_configure_write(struct device *dev,
 298                                    struct device_attribute *attr,
 299                                    const char *buf, size_t count)
 300 {
 301         struct channel_path *cp;
 302         int val;
 303         char delim;
 304
 305         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 306                 return -EINVAL;
 307         if (val != 0 && val != 1)
 308                 return -EINVAL;
 309         cp = to_channelpath(dev);
 310         chp_cfg_schedule(cp->chpid, val);
 311         cfg_wait_idle();
 312
 313         return count;
 314 }
 315
 316 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 317
 318 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
 319                              char *buf)
 320 {
 321         struct channel_path *chp = to_channelpath(dev);
 322         u8 type;
 323
 324         mutex_lock(&chp->lock);
 325         type = chp->desc.desc;
 326         mutex_unlock(&chp->lock);
 327         return sysfs_emit(buf, "%x\n", type);
 328 }
 329
 330 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 331
 332 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
 333                             char *buf)
 334 {
 335         struct channel_path *chp = to_channelpath(dev);
 336
 337         if (!chp)
 338                 return 0;
 339         if (chp->cmg == -1) /* channel measurements not available */
 340                 return sysfs_emit(buf, "unknown\n");
 341         return sysfs_emit(buf, "%d\n", chp->cmg);
 342 }
 343
 344 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 345
 346 static ssize_t chp_shared_show(struct device *dev,
 347                                struct device_attribute *attr, char *buf)
 348 {
 349         struct channel_path *chp = to_channelpath(dev);
 350
 351         if (!chp)
 352                 return 0;
 353         if (chp->shared == -1) /* channel measurements not available */
 354                 return sysfs_emit(buf, "unknown\n");
 355         return sysfs_emit(buf, "%x\n", chp->shared);
 356 }
 357
 358 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 359
 360 static ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr,
 361                              char *buf)
 362 {
 363         struct channel_path *chp = to_channelpath(dev);
 364         ssize_t rc;
 365
 366         mutex_lock(&chp->lock);
 367         if (chp->desc_fmt1.flags & 0x10)
 368                 rc = sysfs_emit(buf, "%04x\n", chp->desc_fmt1.chid);
 369         else
 370                 rc = 0;
 371         mutex_unlock(&chp->lock);
 372
 373         return rc;
 374 }
 375 static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL);
 376
 377 static ssize_t chp_chid_external_show(struct device *dev,
 378                                       struct device_attribute *attr, char *buf)
 379 {
 380         struct channel_path *chp = to_channelpath(dev);
 381         ssize_t rc;
 382
 383         mutex_lock(&chp->lock);
 384         if (chp->desc_fmt1.flags & 0x10)
 385                 rc = sysfs_emit(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0);
 386         else
 387                 rc = 0;
 388         mutex_unlock(&chp->lock);
 389
 390         return rc;
 391 }
 392 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
 393
 394 static ssize_t chp_esc_show(struct device *dev,
 395                             struct device_attribute *attr, char *buf)
 396 {
 397         struct channel_path *chp = to_channelpath(dev);
 398         ssize_t rc;
 399
 400         mutex_lock(&chp->lock);
 401         rc = sysfs_emit(buf, "%x\n", chp->desc_fmt1.esc);
 402         mutex_unlock(&chp->lock);
 403
 404         return rc;
 405 }
 406 static DEVICE_ATTR(esc, 0444, chp_esc_show, NULL);
 407
 408 static char apply_max_suffix(unsigned long *value, unsigned long base)
 409 {
 410         static char suffixes[] = { 0, 'K', 'M', 'G', 'T' };
 411         int i;
 412
 413         for (i = 0; i < ARRAY_SIZE(suffixes) - 1; i++) {
 414                 if (*value < base || *value % base != 0)
 415                         break;
 416                 *value /= base;
 417         }
 418
 419         return suffixes[i];
 420 }
 421
 422 static ssize_t speed_bps_show(struct device *dev,
 423                               struct device_attribute *attr, char *buf)
 424 {
 425         struct channel_path *chp = to_channelpath(dev);
 426         unsigned long speed = chp->speed;
 427         char suffix;
 428
 429         suffix = apply_max_suffix(&speed, 1000);
 430
 431         return suffix ? sysfs_emit(buf, "%lu%c\n", speed, suffix) :
 432                         sysfs_emit(buf, "%lu\n", speed);
 433 }
 434
 435 static DEVICE_ATTR_RO(speed_bps);
 436
 437 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
 438                                 struct bin_attribute *attr, char *buf,
 439                                 loff_t off, size_t count)
 440 {
 441         struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
 442         ssize_t rc;
 443
 444         mutex_lock(&chp->lock);
 445         rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
 446                                      sizeof(chp->desc_fmt3.util_str));
 447         mutex_unlock(&chp->lock);
 448
 449         return rc;
 450 }
 451 static BIN_ATTR_RO(util_string,
 452                    sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
 453
 454 static struct bin_attribute *chp_bin_attrs[] = {
 455         &bin_attr_util_string,
 456         NULL,
 457 };
 458
 459 static struct attribute *chp_attrs[] = {
 460         &dev_attr_status.attr,
 461         &dev_attr_configure.attr,
 462         &dev_attr_type.attr,
 463         &dev_attr_cmg.attr,
 464         &dev_attr_shared.attr,
 465         &dev_attr_chid.attr,
 466         &dev_attr_chid_external.attr,
 467         &dev_attr_esc.attr,
 468         &dev_attr_speed_bps.attr,
 469         NULL,
 470 };
 471 static struct attribute_group chp_attr_group = {
 472         .attrs = chp_attrs,
 473         .bin_attrs = chp_bin_attrs,
 474 };
 475 static const struct attribute_group *chp_attr_groups[] = {
 476         &chp_attr_group,
 477         NULL,
 478 };
 479
 480 static void chp_release(struct device *dev)
 481 {
 482         struct channel_path *cp;
 483
 484         cp = to_channelpath(dev);
 485         kfree(cp);
 486 }
 487
 488 /**
 489  * chp_update_desc - update channel-path description
 490  * @chp: channel-path
 491  *
 492  * Update the channel-path description of the specified channel-path
 493  * including channel measurement related information.
 494  * Return zero on success, non-zero otherwise.
 495  */
 496 int chp_update_desc(struct channel_path *chp)
 497 {
 498         int rc;
 499
 500         rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc);
 501         if (rc)
 502                 return rc;
 503
 504         /*
 505          * Fetching the following data is optional. Not all machines or
 506          * hypervisors implement the required chsc commands.
 507          */
 508         chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
 509         chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3);
 510         chsc_get_channel_measurement_chars(chp);
 511
 512         return 0;
 513 }
 514
 515 /**
 516  * chp_new - register a new channel-path
 517  * @chpid: channel-path ID
 518  *
 519  * Create and register data structure representing new channel-path. Return
 520  * zero on success, non-zero otherwise.
 521  */
 522 int chp_new(struct chp_id chpid)
 523 {
 524         struct channel_subsystem *css = css_by_id(chpid.cssid);
 525         struct channel_path *chp;
 526         int ret = 0;
 527
 528         mutex_lock(&css->mutex);
 529         if (chp_is_registered(chpid))
 530                 goto out;
 531
 532         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 533         if (!chp) {
 534                 ret = -ENOMEM;
 535                 goto out;
 536         }
 537         /* fill in status, etc. */
 538         chp->chpid = chpid;
 539         chp->state = 1;
 540         chp->dev.parent = &css->device;
 541         chp->dev.groups = chp_attr_groups;
 542         chp->dev.release = chp_release;
 543         mutex_init(&chp->lock);
 544
 545         /* Obtain channel path description and fill it in. */
 546         ret = chp_update_desc(chp);
 547         if (ret)
 548                 goto out_free;
 549         if ((chp->desc.flags & 0x80) == 0) {
 550                 ret = -ENODEV;
 551                 goto out_free;
 552         }
 553         dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 554
 555         /* make it known to the system */
 556         ret = device_register(&chp->dev);
 557         if (ret) {
 558                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 559                               chpid.cssid, chpid.id, ret);
 560                 put_device(&chp->dev);
 561                 goto out;
 562         }
 563
 564         if (css->cm_enabled) {
 565                 ret = chp_add_cmg_attr(chp);
 566                 if (ret) {
 567                         device_unregister(&chp->dev);
 568                         goto out;
 569                 }
 570         }
 571         css->chps[chpid.id] = chp;
 572         goto out;
 573 out_free:
 574         kfree(chp);
 575 out:
 576         mutex_unlock(&css->mutex);
 577         return ret;
 578 }
 579
 580 /**
 581  * chp_get_chp_desc - return newly allocated channel-path description
 582  * @chpid: channel-path ID
 583  *
 584  * On success return a newly allocated copy of the channel-path description
 585  * data associated with the given channel-path ID. Return %NULL on error.
 586  */
 587 struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid)
 588 {
 589         struct channel_path *chp;
 590         struct channel_path_desc_fmt0 *desc;
 591
 592         chp = chpid_to_chp(chpid);
 593         if (!chp)
 594                 return NULL;
 595         desc = kmalloc(sizeof(*desc), GFP_KERNEL);
 596         if (!desc)
 597                 return NULL;
 598
 599         mutex_lock(&chp->lock);
 600         memcpy(desc, &chp->desc, sizeof(*desc));
 601         mutex_unlock(&chp->lock);
 602         return desc;
 603 }
 604
 605 /**
 606  * chp_process_crw - process channel-path status change
 607  * @crw0: channel report-word to handler
 608  * @crw1: second channel-report word (always NULL)
 609  * @overflow: crw overflow indication
 610  *
 611  * Handle channel-report-words indicating that the status of a channel-path
 612  * has changed.
 613  */
 614 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
 615                             int overflow)
 616 {
 617         struct chp_id chpid;
 618
 619         if (overflow) {
 620                 css_schedule_eval_all();
 621                 return;
 622         }
 623         CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
 624                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 625                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 626                       crw0->erc, crw0->rsid);
 627         /*
 628          * Check for solicited machine checks. These are
 629          * created by reset channel path and need not be
 630          * handled here.
 631          */
 632         if (crw0->slct) {
 633                 CIO_CRW_EVENT(2, "solicited machine check for "
 634                               "channel path %02X\n", crw0->rsid);
 635                 return;
 636         }
 637         chp_id_init(&chpid);
 638         chpid.id = crw0->rsid;
 639         switch (crw0->erc) {
 640         case CRW_ERC_IPARM: /* Path has come. */
 641         case CRW_ERC_INIT:
 642                 chp_new(chpid);
 643                 chsc_chp_online(chpid);
 644                 break;
 645         case CRW_ERC_PERRI: /* Path has gone. */
 646         case CRW_ERC_PERRN:
 647                 chsc_chp_offline(chpid);
 648                 break;
 649         default:
 650                 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
 651                               crw0->erc);
 652         }
 653 }
 654
 655 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
 656 {
 657         int i;
 658         int mask;
 659
 660         for (i = 0; i < 8; i++) {
 661                 mask = 0x80 >> i;
 662                 if (!(ssd->path_mask & mask))
 663                         continue;
 664                 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
 665                         continue;
 666                 if ((ssd->fla_valid_mask & mask) &&
 667                     ((ssd->fla[i] & link->fla_mask) != link->fla))
 668                         continue;
 669                 return mask;
 670         }
 671         return 0;
 672 }
 673 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
 674
 675 static inline int info_bit_num(struct chp_id id)
 676 {
 677         return id.id + id.cssid * (__MAX_CHPID + 1);
 678 }
 679
 680 /* Force chp_info refresh on next call to info_validate(). */
 681 static void info_expire(void)
 682 {
 683         mutex_lock(&info_lock);
 684         chp_info_expires = jiffies - 1;
 685         mutex_unlock(&info_lock);
 686 }
 687
 688 /* Ensure that chp_info is up-to-date. */
 689 static int info_update(void)
 690 {
 691         int rc;
 692
 693         mutex_lock(&info_lock);
 694         rc = 0;
 695         if (time_after(jiffies, chp_info_expires)) {
 696                 /* Data is too old, update. */
 697                 rc = sclp_chp_read_info(&chp_info);
 698                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 699         }
 700         mutex_unlock(&info_lock);
 701
 702         return rc;
 703 }
 704
 705 /**
 706  * chp_info_get_status - retrieve configure status of a channel-path
 707  * @chpid: channel-path ID
 708  *
 709  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 710  * 3 for not recognized. Return negative error code on error.
 711  */
 712 int chp_info_get_status(struct chp_id chpid)
 713 {
 714         int rc;
 715         int bit;
 716
 717         rc = info_update();
 718         if (rc)
 719                 return rc;
 720
 721         bit = info_bit_num(chpid);
 722         mutex_lock(&info_lock);
 723         if (!chp_test_bit(chp_info.recognized, bit))
 724                 rc = CHP_STATUS_NOT_RECOGNIZED;
 725         else if (chp_test_bit(chp_info.configured, bit))
 726                 rc = CHP_STATUS_CONFIGURED;
 727         else if (chp_test_bit(chp_info.standby, bit))
 728                 rc = CHP_STATUS_STANDBY;
 729         else
 730                 rc = CHP_STATUS_RESERVED;
 731         mutex_unlock(&info_lock);
 732
 733         return rc;
 734 }
 735
 736 /* Return configure task for chpid. */
 737 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 738 {
 739         return chp_cfg_task[chpid.cssid][chpid.id];
 740 }
 741
 742 /* Set configure task for chpid. */
 743 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 744 {
 745         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 746 }
 747
 748 /* Fetch the first configure task. Set chpid accordingly. */
 749 static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid)
 750 {
 751         enum cfg_task_t t = cfg_none;
 752
 753         chp_id_for_each(chpid) {
 754                 t = cfg_get_task(*chpid);
 755                 if (t != cfg_none)
 756                         break;
 757         }
 758
 759         return t;
 760 }
 761
 762 /* Perform one configure/deconfigure request. Reschedule work function until
 763  * last request. */
 764 static void cfg_func(struct work_struct *work)
 765 {
 766         struct chp_id chpid;
 767         enum cfg_task_t t;
 768         int rc;
 769
 770         spin_lock(&cfg_lock);
 771         t = chp_cfg_fetch_task(&chpid);
 772         spin_unlock(&cfg_lock);
 773
 774         switch (t) {
 775         case cfg_configure:
 776                 rc = sclp_chp_configure(chpid);
 777                 if (rc)
 778                         CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
 779                                       "%d\n", chpid.cssid, chpid.id, rc);
 780                 else {
 781                         info_expire();
 782                         chsc_chp_online(chpid);
 783                 }
 784                 break;
 785         case cfg_deconfigure:
 786                 rc = sclp_chp_deconfigure(chpid);
 787                 if (rc)
 788                         CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
 789                                       "%d\n", chpid.cssid, chpid.id, rc);
 790                 else {
 791                         info_expire();
 792                         chsc_chp_offline(chpid);
 793                 }
 794                 break;
 795         case cfg_none:
 796                 /* Get updated information after last change. */
 797                 info_update();
 798                 wake_up_interruptible(&cfg_wait_queue);
 799                 return;
 800         }
 801         spin_lock(&cfg_lock);
 802         if (t == cfg_get_task(chpid))
 803                 cfg_set_task(chpid, cfg_none);
 804         spin_unlock(&cfg_lock);
 805         schedule_work(&cfg_work);
 806 }
 807
 808 /**
 809  * chp_cfg_schedule - schedule chpid configuration request
 810  * @chpid: channel-path ID
 811  * @configure: Non-zero for configure, zero for deconfigure
 812  *
 813  * Schedule a channel-path configuration/deconfiguration request.
 814  */
 815 void chp_cfg_schedule(struct chp_id chpid, int configure)
 816 {
 817         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 818                       configure);
 819         spin_lock(&cfg_lock);
 820         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 821         spin_unlock(&cfg_lock);
 822         schedule_work(&cfg_work);
 823 }
 824
 825 /**
 826  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 827  * @chpid: channel-path ID
 828  *
 829  * Cancel an active channel-path deconfiguration request if it has not yet
 830  * been performed.
 831  */
 832 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 833 {
 834         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 835         spin_lock(&cfg_lock);
 836         if (cfg_get_task(chpid) == cfg_deconfigure)
 837                 cfg_set_task(chpid, cfg_none);
 838         spin_unlock(&cfg_lock);
 839 }
 840
 841 static bool cfg_idle(void)
 842 {
 843         struct chp_id chpid;
 844         enum cfg_task_t t;
 845
 846         spin_lock(&cfg_lock);
 847         t = chp_cfg_fetch_task(&chpid);
 848         spin_unlock(&cfg_lock);
 849
 850         return t == cfg_none;
 851 }
 852
 853 static int cfg_wait_idle(void)
 854 {
 855         if (wait_event_interruptible(cfg_wait_queue, cfg_idle()))
 856                 return -ERESTARTSYS;
 857         return 0;
 858 }
 859
 860 static int __init chp_init(void)
 861 {
 862         struct chp_id chpid;
 863         int state, ret;
 864
 865         ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
 866         if (ret)
 867                 return ret;
 868         INIT_WORK(&cfg_work, cfg_func);
 869         if (info_update())
 870                 return 0;
 871         /* Register available channel-paths. */
 872         chp_id_for_each(&chpid) {
 873                 state = chp_info_get_status(chpid);
 874                 if (state == CHP_STATUS_CONFIGURED ||
 875                     state == CHP_STATUS_STANDBY)
 876                         chp_new(chpid);
 877         }
 878
 879         return 0;
 880 }
 881
 882 subsys_initcall(chp_init);