drivers/s390/cio/chp.c

   1 /*
   2  *  drivers/s390/cio/chp.c
   3  *
   4  *    Copyright IBM Corp. 1999,2007
   5  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
   6  *               Arnd Bergmann (arndb@de.ibm.com)
   7  *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   8  */
   9
  10 #include <linux/bug.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/init.h>
  14 #include <linux/jiffies.h>
  15 #include <linux/wait.h>
  16 #include <linux/mutex.h>
  17 #include <asm/errno.h>
  18 #include <asm/chpid.h>
  19 #include <asm/sclp.h>
  20
  21 #include "cio.h"
  22 #include "css.h"
  23 #include "ioasm.h"
  24 #include "cio_debug.h"
  25 #include "chp.h"
  26
  27 #define to_channelpath(device) container_of(device, struct channel_path, dev)
  28 #define CHP_INFO_UPDATE_INTERVAL        1*HZ
  29
  30 enum cfg_task_t {
  31         cfg_none,
  32         cfg_configure,
  33         cfg_deconfigure
  34 };
  35
  36 /* Map for pending configure tasks. */
  37 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
  38 static DEFINE_MUTEX(cfg_lock);
  39 static int cfg_busy;
  40
  41 /* Map for channel-path status. */
  42 static struct sclp_chp_info chp_info;
  43 static DEFINE_MUTEX(info_lock);
  44
  45 /* Time after which channel-path status may be outdated. */
  46 static unsigned long chp_info_expires;
  47
  48 /* Workqueue to perform pending configure tasks. */
  49 static struct workqueue_struct *chp_wq;
  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 /* Return channel_path struct for given chpid. */
  56 static inline struct channel_path *chpid_to_chp(struct chp_id chpid)
  57 {
  58         return css[chpid.cssid]->chps[chpid.id];
  59 }
  60
  61 /* Set vary state for given chpid. */
  62 static void set_chp_logically_online(struct chp_id chpid, int onoff)
  63 {
  64         chpid_to_chp(chpid)->state = onoff;
  65 }
  66
  67 /* On succes return 0 if channel-path is varied offline, 1 if it is varied
  68  * online. Return -ENODEV if channel-path is not registered. */
  69 int chp_get_status(struct chp_id chpid)
  70 {
  71         return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
  72 }
  73
  74 /**
  75  * chp_get_sch_opm - return opm for subchannel
  76  * @sch: subchannel
  77  *
  78  * Calculate and return the operational path mask (opm) based on the chpids
  79  * used by the subchannel and the status of the associated channel-paths.
  80  */
  81 u8 chp_get_sch_opm(struct subchannel *sch)
  82 {
  83         struct chp_id chpid;
  84         int opm;
  85         int i;
  86
  87         opm = 0;
  88         chp_id_init(&chpid);
  89         for (i=0; i < 8; i++) {
  90                 opm <<= 1;
  91                 chpid.id = sch->schib.pmcw.chpid[i];
  92                 if (chp_get_status(chpid) != 0)
  93                         opm |= 1;
  94         }
  95         return opm;
  96 }
  97
  98 /**
  99  * chp_is_registered - check if a channel-path is registered
 100  * @chpid: channel-path ID
 101  *
 102  * Return non-zero if a channel-path with the given chpid is registered,
 103  * zero otherwise.
 104  */
 105 int chp_is_registered(struct chp_id chpid)
 106 {
 107         return chpid_to_chp(chpid) != NULL;
 108 }
 109
 110 /*
 111  * Function: s390_vary_chpid
 112  * Varies the specified chpid online or offline
 113  */
 114 static int s390_vary_chpid(struct chp_id chpid, int on)
 115 {
 116         char dbf_text[15];
 117         int status;
 118
 119         sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
 120                 chpid.id);
 121         CIO_TRACE_EVENT( 2, dbf_text);
 122
 123         status = chp_get_status(chpid);
 124         if (!on && !status) {
 125                 printk(KERN_ERR "cio: chpid %x.%02x is already offline\n",
 126                        chpid.cssid, chpid.id);
 127                 return -EINVAL;
 128         }
 129
 130         set_chp_logically_online(chpid, on);
 131         chsc_chp_vary(chpid, on);
 132         return 0;
 133 }
 134
 135 /*
 136  * Channel measurement related functions
 137  */
 138 static ssize_t chp_measurement_chars_read(struct kobject *kobj,
 139                                           struct bin_attribute *bin_attr,
 140                                           char *buf, loff_t off, size_t count)
 141 {
 142         struct channel_path *chp;
 143         unsigned int size;
 144
 145         chp = to_channelpath(container_of(kobj, struct device, kobj));
 146         if (!chp->cmg_chars)
 147                 return 0;
 148
 149         size = sizeof(struct cmg_chars);
 150
 151         if (off > size)
 152                 return 0;
 153         if (off + count > size)
 154                 count = size - off;
 155         memcpy(buf, chp->cmg_chars + off, count);
 156         return count;
 157 }
 158
 159 static struct bin_attribute chp_measurement_chars_attr = {
 160         .attr = {
 161                 .name = "measurement_chars",
 162                 .mode = S_IRUSR,
 163         },
 164         .size = sizeof(struct cmg_chars),
 165         .read = chp_measurement_chars_read,
 166 };
 167
 168 static void chp_measurement_copy_block(struct cmg_entry *buf,
 169                                        struct channel_subsystem *css,
 170                                        struct chp_id chpid)
 171 {
 172         void *area;
 173         struct cmg_entry *entry, reference_buf;
 174         int idx;
 175
 176         if (chpid.id < 128) {
 177                 area = css->cub_addr1;
 178                 idx = chpid.id;
 179         } else {
 180                 area = css->cub_addr2;
 181                 idx = chpid.id - 128;
 182         }
 183         entry = area + (idx * sizeof(struct cmg_entry));
 184         do {
 185                 memcpy(buf, entry, sizeof(*entry));
 186                 memcpy(&reference_buf, entry, sizeof(*entry));
 187         } while (reference_buf.values[0] != buf->values[0]);
 188 }
 189
 190 static ssize_t chp_measurement_read(struct kobject *kobj,
 191                                     struct bin_attribute *bin_attr,
 192                                     char *buf, loff_t off, size_t count)
 193 {
 194         struct channel_path *chp;
 195         struct channel_subsystem *css;
 196         unsigned int size;
 197
 198         chp = to_channelpath(container_of(kobj, struct device, kobj));
 199         css = to_css(chp->dev.parent);
 200
 201         size = sizeof(struct cmg_entry);
 202
 203         /* Only allow single reads. */
 204         if (off || count < size)
 205                 return 0;
 206         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
 207         count = size;
 208         return count;
 209 }
 210
 211 static struct bin_attribute chp_measurement_attr = {
 212         .attr = {
 213                 .name = "measurement",
 214                 .mode = S_IRUSR,
 215         },
 216         .size = sizeof(struct cmg_entry),
 217         .read = chp_measurement_read,
 218 };
 219
 220 void chp_remove_cmg_attr(struct channel_path *chp)
 221 {
 222         device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 223         device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 224 }
 225
 226 int chp_add_cmg_attr(struct channel_path *chp)
 227 {
 228         int ret;
 229
 230         ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 231         if (ret)
 232                 return ret;
 233         ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 234         if (ret)
 235                 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 236         return ret;
 237 }
 238
 239 /*
 240  * Files for the channel path entries.
 241  */
 242 static ssize_t chp_status_show(struct device *dev,
 243                                struct device_attribute *attr, char *buf)
 244 {
 245         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 246
 247         if (!chp)
 248                 return 0;
 249         return (chp_get_status(chp->chpid) ? sprintf(buf, "online\n") :
 250                 sprintf(buf, "offline\n"));
 251 }
 252
 253 static ssize_t chp_status_write(struct device *dev,
 254                                 struct device_attribute *attr,
 255                                 const char *buf, size_t count)
 256 {
 257         struct channel_path *cp = container_of(dev, struct channel_path, dev);
 258         char cmd[10];
 259         int num_args;
 260         int error;
 261
 262         num_args = sscanf(buf, "%5s", cmd);
 263         if (!num_args)
 264                 return count;
 265
 266         if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1"))
 267                 error = s390_vary_chpid(cp->chpid, 1);
 268         else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0"))
 269                 error = s390_vary_chpid(cp->chpid, 0);
 270         else
 271                 error = -EINVAL;
 272
 273         return error < 0 ? error : count;
 274
 275 }
 276
 277 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 278
 279 static ssize_t chp_configure_show(struct device *dev,
 280                                   struct device_attribute *attr, char *buf)
 281 {
 282         struct channel_path *cp;
 283         int status;
 284
 285         cp = container_of(dev, struct channel_path, dev);
 286         status = chp_info_get_status(cp->chpid);
 287         if (status < 0)
 288                 return status;
 289
 290         return snprintf(buf, PAGE_SIZE, "%d\n", status);
 291 }
 292
 293 static int cfg_wait_idle(void);
 294
 295 static ssize_t chp_configure_write(struct device *dev,
 296                                    struct device_attribute *attr,
 297                                    const char *buf, size_t count)
 298 {
 299         struct channel_path *cp;
 300         int val;
 301         char delim;
 302
 303         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 304                 return -EINVAL;
 305         if (val != 0 && val != 1)
 306                 return -EINVAL;
 307         cp = container_of(dev, struct channel_path, dev);
 308         chp_cfg_schedule(cp->chpid, val);
 309         cfg_wait_idle();
 310
 311         return count;
 312 }
 313
 314 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 315
 316 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
 317                              char *buf)
 318 {
 319         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 320
 321         if (!chp)
 322                 return 0;
 323         return sprintf(buf, "%x\n", chp->desc.desc);
 324 }
 325
 326 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 327
 328 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
 329                             char *buf)
 330 {
 331         struct channel_path *chp = to_channelpath(dev);
 332
 333         if (!chp)
 334                 return 0;
 335         if (chp->cmg == -1) /* channel measurements not available */
 336                 return sprintf(buf, "unknown\n");
 337         return sprintf(buf, "%x\n", chp->cmg);
 338 }
 339
 340 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 341
 342 static ssize_t chp_shared_show(struct device *dev,
 343                                struct device_attribute *attr, char *buf)
 344 {
 345         struct channel_path *chp = to_channelpath(dev);
 346
 347         if (!chp)
 348                 return 0;
 349         if (chp->shared == -1) /* channel measurements not available */
 350                 return sprintf(buf, "unknown\n");
 351         return sprintf(buf, "%x\n", chp->shared);
 352 }
 353
 354 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 355
 356 static struct attribute * chp_attrs[] = {
 357         &dev_attr_status.attr,
 358         &dev_attr_configure.attr,
 359         &dev_attr_type.attr,
 360         &dev_attr_cmg.attr,
 361         &dev_attr_shared.attr,
 362         NULL,
 363 };
 364
 365 static struct attribute_group chp_attr_group = {
 366         .attrs = chp_attrs,
 367 };
 368
 369 static void chp_release(struct device *dev)
 370 {
 371         struct channel_path *cp;
 372
 373         cp = container_of(dev, struct channel_path, dev);
 374         kfree(cp);
 375 }
 376
 377 /**
 378  * chp_new - register a new channel-path
 379  * @chpid - channel-path ID
 380  *
 381  * Create and register data structure representing new channel-path. Return
 382  * zero on success, non-zero otherwise.
 383  */
 384 int chp_new(struct chp_id chpid)
 385 {
 386         struct channel_path *chp;
 387         int ret;
 388
 389         if (chp_is_registered(chpid))
 390                 return 0;
 391         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 392         if (!chp)
 393                 return -ENOMEM;
 394
 395         /* fill in status, etc. */
 396         chp->chpid = chpid;
 397         chp->state = 1;
 398         chp->dev.parent = &css[chpid.cssid]->device;
 399         chp->dev.release = chp_release;
 400         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp%x.%02x", chpid.cssid,
 401                  chpid.id);
 402
 403         /* Obtain channel path description and fill it in. */
 404         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
 405         if (ret)
 406                 goto out_free;
 407         if ((chp->desc.flags & 0x80) == 0) {
 408                 ret = -ENODEV;
 409                 goto out_free;
 410         }
 411         /* Get channel-measurement characteristics. */
 412         if (css_characteristics_avail && css_chsc_characteristics.scmc
 413             && css_chsc_characteristics.secm) {
 414                 ret = chsc_get_channel_measurement_chars(chp);
 415                 if (ret)
 416                         goto out_free;
 417         } else {
 418                 chp->cmg = -1;
 419         }
 420
 421         /* make it known to the system */
 422         ret = device_register(&chp->dev);
 423         if (ret) {
 424                 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
 425                               chpid.cssid, chpid.id, ret);
 426                 goto out_free;
 427         }
 428         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
 429         if (ret) {
 430                 device_unregister(&chp->dev);
 431                 goto out_free;
 432         }
 433         mutex_lock(&css[chpid.cssid]->mutex);
 434         if (css[chpid.cssid]->cm_enabled) {
 435                 ret = chp_add_cmg_attr(chp);
 436                 if (ret) {
 437                         sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
 438                         device_unregister(&chp->dev);
 439                         mutex_unlock(&css[chpid.cssid]->mutex);
 440                         goto out_free;
 441                 }
 442         }
 443         css[chpid.cssid]->chps[chpid.id] = chp;
 444         mutex_unlock(&css[chpid.cssid]->mutex);
 445         return ret;
 446 out_free:
 447         kfree(chp);
 448         return ret;
 449 }
 450
 451 /**
 452  * chp_get_chp_desc - return newly allocated channel-path description
 453  * @chpid: channel-path ID
 454  *
 455  * On success return a newly allocated copy of the channel-path description
 456  * data associated with the given channel-path ID. Return %NULL on error.
 457  */
 458 void *chp_get_chp_desc(struct chp_id chpid)
 459 {
 460         struct channel_path *chp;
 461         struct channel_path_desc *desc;
 462
 463         chp = chpid_to_chp(chpid);
 464         if (!chp)
 465                 return NULL;
 466         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
 467         if (!desc)
 468                 return NULL;
 469         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
 470         return desc;
 471 }
 472
 473 /**
 474  * chp_process_crw - process channel-path status change
 475  * @id: channel-path ID number
 476  * @status: non-zero if channel-path has become available, zero otherwise
 477  *
 478  * Handle channel-report-words indicating that the status of a channel-path
 479  * has changed.
 480  */
 481 void chp_process_crw(int id, int status)
 482 {
 483         struct chp_id chpid;
 484
 485         chp_id_init(&chpid);
 486         chpid.id = id;
 487         if (status) {
 488                 if (!chp_is_registered(chpid))
 489                         chp_new(chpid);
 490                 chsc_chp_online(chpid);
 491         } else
 492                 chsc_chp_offline(chpid);
 493 }
 494
 495 static inline int info_bit_num(struct chp_id id)
 496 {
 497         return id.id + id.cssid * (__MAX_CHPID + 1);
 498 }
 499
 500 /* Force chp_info refresh on next call to info_validate(). */
 501 static void info_expire(void)
 502 {
 503         mutex_lock(&info_lock);
 504         chp_info_expires = jiffies - 1;
 505         mutex_unlock(&info_lock);
 506 }
 507
 508 /* Ensure that chp_info is up-to-date. */
 509 static int info_update(void)
 510 {
 511         int rc;
 512
 513         mutex_lock(&info_lock);
 514         rc = 0;
 515         if (time_after(jiffies, chp_info_expires)) {
 516                 /* Data is too old, update. */
 517                 rc = sclp_chp_read_info(&chp_info);
 518                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 519         }
 520         mutex_unlock(&info_lock);
 521
 522         return rc;
 523 }
 524
 525 /**
 526  * chp_info_get_status - retrieve configure status of a channel-path
 527  * @chpid: channel-path ID
 528  *
 529  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 530  * 3 for not recognized. Return negative error code on error.
 531  */
 532 int chp_info_get_status(struct chp_id chpid)
 533 {
 534         int rc;
 535         int bit;
 536
 537         rc = info_update();
 538         if (rc)
 539                 return rc;
 540
 541         bit = info_bit_num(chpid);
 542         mutex_lock(&info_lock);
 543         if (!chp_test_bit(chp_info.recognized, bit))
 544                 rc = CHP_STATUS_NOT_RECOGNIZED;
 545         else if (chp_test_bit(chp_info.configured, bit))
 546                 rc = CHP_STATUS_CONFIGURED;
 547         else if (chp_test_bit(chp_info.standby, bit))
 548                 rc = CHP_STATUS_STANDBY;
 549         else
 550                 rc = CHP_STATUS_RESERVED;
 551         mutex_unlock(&info_lock);
 552
 553         return rc;
 554 }
 555
 556 /* Return configure task for chpid. */
 557 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 558 {
 559         return chp_cfg_task[chpid.cssid][chpid.id];
 560 }
 561
 562 /* Set configure task for chpid. */
 563 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 564 {
 565         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 566 }
 567
 568 /* Perform one configure/deconfigure request. Reschedule work function until
 569  * last request. */
 570 static void cfg_func(struct work_struct *work)
 571 {
 572         struct chp_id chpid;
 573         enum cfg_task_t t;
 574
 575         mutex_lock(&cfg_lock);
 576         t = cfg_none;
 577         chp_id_for_each(&chpid) {
 578                 t = cfg_get_task(chpid);
 579                 if (t != cfg_none) {
 580                         cfg_set_task(chpid, cfg_none);
 581                         break;
 582                 }
 583         }
 584         mutex_unlock(&cfg_lock);
 585
 586         switch (t) {
 587         case cfg_configure:
 588                 sclp_chp_configure(chpid);
 589                 info_expire();
 590                 chsc_chp_online(chpid);
 591                 break;
 592         case cfg_deconfigure:
 593                 sclp_chp_deconfigure(chpid);
 594                 info_expire();
 595                 chsc_chp_offline(chpid);
 596                 break;
 597         case cfg_none:
 598                 /* Get updated information after last change. */
 599                 info_update();
 600                 mutex_lock(&cfg_lock);
 601                 cfg_busy = 0;
 602                 mutex_unlock(&cfg_lock);
 603                 wake_up_interruptible(&cfg_wait_queue);
 604                 return;
 605         }
 606         queue_work(chp_wq, &cfg_work);
 607 }
 608
 609 /**
 610  * chp_cfg_schedule - schedule chpid configuration request
 611  * @chpid - channel-path ID
 612  * @configure - Non-zero for configure, zero for deconfigure
 613  *
 614  * Schedule a channel-path configuration/deconfiguration request.
 615  */
 616 void chp_cfg_schedule(struct chp_id chpid, int configure)
 617 {
 618         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 619                       configure);
 620         mutex_lock(&cfg_lock);
 621         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 622         cfg_busy = 1;
 623         mutex_unlock(&cfg_lock);
 624         queue_work(chp_wq, &cfg_work);
 625 }
 626
 627 /**
 628  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 629  * @chpid - channel-path ID
 630  *
 631  * Cancel an active channel-path deconfiguration request if it has not yet
 632  * been performed.
 633  */
 634 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 635 {
 636         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 637         mutex_lock(&cfg_lock);
 638         if (cfg_get_task(chpid) == cfg_deconfigure)
 639                 cfg_set_task(chpid, cfg_none);
 640         mutex_unlock(&cfg_lock);
 641 }
 642
 643 static int cfg_wait_idle(void)
 644 {
 645         if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
 646                 return -ERESTARTSYS;
 647         return 0;
 648 }
 649
 650 static int __init chp_init(void)
 651 {
 652         struct chp_id chpid;
 653
 654         chp_wq = create_singlethread_workqueue("cio_chp");
 655         if (!chp_wq)
 656                 return -ENOMEM;
 657         INIT_WORK(&cfg_work, cfg_func);
 658         init_waitqueue_head(&cfg_wait_queue);
 659         if (info_update())
 660                 return 0;
 661         /* Register available channel-paths. */
 662         chp_id_for_each(&chpid) {
 663                 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
 664                         chp_new(chpid);
 665         }
 666
 667         return 0;
 668 }
 669
 670 subsys_initcall(chp_init);