release/src-rt-6.x/linux/linux-2.6/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  45 /* Time after which channel-path status may be outdated.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 (status < 0) {
 125                 printk(KERN_ERR "Can't vary unknown chpid %x.%02x\n",
 126                        chpid.cssid, chpid.id);
 127                 return -EINVAL;
 128         }
 129
 130         if (!on && !status) {
 131                 printk(KERN_ERR "chpid %x.%02x is already offline\n",
 132                        chpid.cssid, chpid.id);
 133                 return -EINVAL;
 134         }
 135
 136         set_chp_logically_online(chpid, on);
 137         chsc_chp_vary(chpid, on);
 138         return 0;
 139 }
 140
 141 /*
 142  * Channel measurement related functions
 143  */
 144 static ssize_t chp_measurement_chars_read(struct kobject *kobj, char *buf,
 145                                           loff_t off, size_t count)
 146 {
 147         struct channel_path *chp;
 148         unsigned int size;
 149
 150         chp = to_channelpath(container_of(kobj, struct device, kobj));
 151         if (!chp->cmg_chars)
 152                 return 0;
 153
 154         size = sizeof(struct cmg_chars);
 155
 156         if (off > size)
 157                 return 0;
 158         if (off + count > size)
 159                 count = size - off;
 160         memcpy(buf, chp->cmg_chars + off, count);
 161         return count;
 162 }
 163
 164 static struct bin_attribute chp_measurement_chars_attr = {
 165         .attr = {
 166                 .name = "measurement_chars",
 167                 .mode = S_IRUSR,
 168                 .owner = THIS_MODULE,
 169         },
 170         .size = sizeof(struct cmg_chars),
 171         .read = chp_measurement_chars_read,
 172 };
 173
 174 static void chp_measurement_copy_block(struct cmg_entry *buf,
 175                                        struct channel_subsystem *css,
 176                                        struct chp_id chpid)
 177 {
 178         void *area;
 179         struct cmg_entry *entry, reference_buf;
 180         int idx;
 181
 182         if (chpid.id < 128) {
 183                 area = css->cub_addr1;
 184                 idx = chpid.id;
 185         } else {
 186                 area = css->cub_addr2;
 187                 idx = chpid.id - 128;
 188         }
 189         entry = area + (idx * sizeof(struct cmg_entry));
 190         do {
 191                 memcpy(buf, entry, sizeof(*entry));
 192                 memcpy(&reference_buf, entry, sizeof(*entry));
 193         } while (reference_buf.values[0] != buf->values[0]);
 194 }
 195
 196 static ssize_t chp_measurement_read(struct kobject *kobj, char *buf,
 197                                     loff_t off, size_t count)
 198 {
 199         struct channel_path *chp;
 200         struct channel_subsystem *css;
 201         unsigned int size;
 202
 203         chp = to_channelpath(container_of(kobj, struct device, kobj));
 204         css = to_css(chp->dev.parent);
 205
 206         size = sizeof(struct cmg_entry);
 207
 208         /* Only allow single reads. */
 209         if (off || count < size)
 210                 return 0;
 211         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
 212         count = size;
 213         return count;
 214 }
 215
 216 static struct bin_attribute chp_measurement_attr = {
 217         .attr = {
 218                 .name = "measurement",
 219                 .mode = S_IRUSR,
 220                 .owner = THIS_MODULE,
 221         },
 222         .size = sizeof(struct cmg_entry),
 223         .read = chp_measurement_read,
 224 };
 225
 226 void chp_remove_cmg_attr(struct channel_path *chp)
 227 {
 228         device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 229         device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 230 }
 231
 232 int chp_add_cmg_attr(struct channel_path *chp)
 233 {
 234         int ret;
 235
 236         ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 237         if (ret)
 238                 return ret;
 239         ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 240         if (ret)
 241                 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 242         return ret;
 243 }
 244
 245 /*
 246  * Files for the channel path entries.
 247  */
 248 static ssize_t chp_status_show(struct device *dev,
 249                                struct device_attribute *attr, char *buf)
 250 {
 251         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 252
 253         if (!chp)
 254                 return 0;
 255         return (chp_get_status(chp->chpid) ? sprintf(buf, "online\n") :
 256                 sprintf(buf, "offline\n"));
 257 }
 258
 259 static ssize_t chp_status_write(struct device *dev,
 260                                 struct device_attribute *attr,
 261                                 const char *buf, size_t count)
 262 {
 263         struct channel_path *cp = container_of(dev, struct channel_path, dev);
 264         char cmd[10];
 265         int num_args;
 266         int error;
 267
 268         num_args = sscanf(buf, "%5s", cmd);
 269         if (!num_args)
 270                 return count;
 271
 272         if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1"))
 273                 error = s390_vary_chpid(cp->chpid, 1);
 274         else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0"))
 275                 error = s390_vary_chpid(cp->chpid, 0);
 276         else
 277                 error = -EINVAL;
 278
 279         return error < 0 ? error : count;
 280
 281 }
 282
 283 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 284
 285 static ssize_t chp_configure_show(struct device *dev,
 286                                   struct device_attribute *attr, char *buf)
 287 {
 288         struct channel_path *cp;
 289         int status;
 290
 291         cp = container_of(dev, struct channel_path, dev);
 292         status = chp_info_get_status(cp->chpid);
 293         if (status < 0)
 294                 return status;
 295
 296         return snprintf(buf, PAGE_SIZE, "%d\n", status);
 297 }
 298
 299 static int cfg_wait_idle(void);
 300
 301 static ssize_t chp_configure_write(struct device *dev,
 302                                    struct device_attribute *attr,
 303                                    const char *buf, size_t count)
 304 {
 305         struct channel_path *cp;
 306         int val;
 307         char delim;
 308
 309         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 310                 return -EINVAL;
 311         if (val != 0 && val != 1)
 312                 return -EINVAL;
 313         cp = container_of(dev, struct channel_path, dev);
 314         chp_cfg_schedule(cp->chpid, val);
 315         cfg_wait_idle();
 316
 317         return count;
 318 }
 319
 320 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
 321
 322 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
 323                              char *buf)
 324 {
 325         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 326
 327         if (!chp)
 328                 return 0;
 329         return sprintf(buf, "%x\n", chp->desc.desc);
 330 }
 331
 332 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 333
 334 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
 335                             char *buf)
 336 {
 337         struct channel_path *chp = to_channelpath(dev);
 338
 339         if (!chp)
 340                 return 0;
 341         if (chp->cmg == -1) /* channel measurements not available */
 342                 return sprintf(buf, "unknown\n");
 343         return sprintf(buf, "%x\n", chp->cmg);
 344 }
 345
 346 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
 347
 348 static ssize_t chp_shared_show(struct device *dev,
 349                                struct device_attribute *attr, char *buf)
 350 {
 351         struct channel_path *chp = to_channelpath(dev);
 352
 353         if (!chp)
 354                 return 0;
 355         if (chp->shared == -1) /* channel measurements not available */
 356                 return sprintf(buf, "unknown\n");
 357         return sprintf(buf, "%x\n", chp->shared);
 358 }
 359
 360 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 361
 362 static struct attribute * chp_attrs[] = {
 363         &dev_attr_status.attr,
 364         &dev_attr_configure.attr,
 365         &dev_attr_type.attr,
 366         &dev_attr_cmg.attr,
 367         &dev_attr_shared.attr,
 368         NULL,
 369 };
 370
 371 static struct attribute_group chp_attr_group = {
 372         .attrs = chp_attrs,
 373 };
 374
 375 static void chp_release(struct device *dev)
 376 {
 377         struct channel_path *cp;
 378
 379         cp = container_of(dev, struct channel_path, dev);
 380         kfree(cp);
 381 }
 382
 383 /**
 384  * chp_new - register a new channel-path
 385  * @chpid - channel-path ID
 386  *
 387  * Create and register data structure representing new channel-path. Return
 388  * zero on success, non-zero otherwise.
 389  */
 390 int chp_new(struct chp_id chpid)
 391 {
 392         struct channel_path *chp;
 393         int ret;
 394
 395         if (chp_is_registered(chpid))
 396                 return 0;
 397         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
 398         if (!chp)
 399                 return -ENOMEM;
 400
 401         /* fill in status, etc. */
 402         chp->chpid = chpid;
 403         chp->state = 1;
 404         chp->dev.parent = &css[chpid.cssid]->device;
 405         chp->dev.release = chp_release;
 406         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp%x.%02x", chpid.cssid,
 407                  chpid.id);
 408
 409         /* Obtain channel path description and fill it in. */
 410         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
 411         if (ret)
 412                 goto out_free;
 413         if ((chp->desc.flags & 0x80) == 0) {
 414                 ret = -ENODEV;
 415                 goto out_free;
 416         }
 417         /* Get channel-measurement characteristics. */
 418         if (css_characteristics_avail && css_chsc_characteristics.scmc
 419             && css_chsc_characteristics.secm) {
 420                 ret = chsc_get_channel_measurement_chars(chp);
 421                 if (ret)
 422                         goto out_free;
 423         } else {
 424                 static int msg_done;
 425
 426                 if (!msg_done) {
 427                         printk(KERN_WARNING "cio: Channel measurements not "
 428                                "available, continuing.\n");
 429                         msg_done = 1;
 430                 }
 431                 chp->cmg = -1;
 432         }
 433
 434         /* make it known to the system */
 435         ret = device_register(&chp->dev);
 436         if (ret) {
 437                 printk(KERN_WARNING "%s: could not register %x.%02x\n",
 438                        __func__, chpid.cssid, chpid.id);
 439                 goto out_free;
 440         }
 441         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
 442         if (ret) {
 443                 device_unregister(&chp->dev);
 444                 goto out_free;
 445         }
 446         mutex_lock(&css[chpid.cssid]->mutex);
 447         if (css[chpid.cssid]->cm_enabled) {
 448                 ret = chp_add_cmg_attr(chp);
 449                 if (ret) {
 450                         sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
 451                         device_unregister(&chp->dev);
 452                         mutex_unlock(&css[chpid.cssid]->mutex);
 453                         goto out_free;
 454                 }
 455         }
 456         css[chpid.cssid]->chps[chpid.id] = chp;
 457         mutex_unlock(&css[chpid.cssid]->mutex);
 458         return ret;
 459 out_free:
 460         kfree(chp);
 461         return ret;
 462 }
 463
 464 /**
 465  * chp_get_chp_desc - return newly allocated channel-path description
 466  * @chpid: channel-path ID
 467  *
 468  * On success return a newly allocated copy of the channel-path description
 469  * data associated with the given channel-path ID. Return %NULL on error.
 470  */
 471 void *chp_get_chp_desc(struct chp_id chpid)
 472 {
 473         struct channel_path *chp;
 474         struct channel_path_desc *desc;
 475
 476         chp = chpid_to_chp(chpid);
 477         if (!chp)
 478                 return NULL;
 479         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
 480         if (!desc)
 481                 return NULL;
 482         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
 483         return desc;
 484 }
 485
 486 /**
 487  * chp_process_crw - process channel-path status change
 488  * @id: channel-path ID number
 489  * @status: non-zero if channel-path has become available, zero otherwise
 490  *
 491  * Handle channel-report-words indicating that the status of a channel-path
 492  * has changed.
 493  */
 494 void chp_process_crw(int id, int status)
 495 {
 496         struct chp_id chpid;
 497
 498         chp_id_init(&chpid);
 499         chpid.id = id;
 500         if (status) {
 501                 if (!chp_is_registered(chpid))
 502                         chp_new(chpid);
 503                 chsc_chp_online(chpid);
 504         } else
 505                 chsc_chp_offline(chpid);
 506 }
 507
 508 static inline int info_bit_num(struct chp_id id)
 509 {
 510         return id.id + id.cssid * (__MAX_CHPID + 1);
 511 }
 512
 513 /* Force chp_info refresh on next call to info_validate(). */
 514 static void info_expire(void)
 515 {
 516         mutex_lock(&info_lock);
 517         chp_info_expires = jiffies - 1;
 518         mutex_unlock(&info_lock);
 519 }
 520
 521 /* Ensure that chp_info is up-to-date. */
 522 static int info_update(void)
 523 {
 524         int rc;
 525
 526         mutex_lock(&info_lock);
 527         rc = 0;
 528         if (time_after(jiffies, chp_info_expires)) {
 529                 /* Data is too old, update. */
 530                 rc = sclp_chp_read_info(&chp_info);
 531                 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
 532         }
 533         mutex_unlock(&info_lock);
 534
 535         return rc;
 536 }
 537
 538 /**
 539  * chp_info_get_status - retrieve configure status of a channel-path
 540  * @chpid: channel-path ID
 541  *
 542  * On success, return 0 for standby, 1 for configured, 2 for reserved,
 543  * 3 for not recognized. Return negative error code on error.
 544  */
 545 int chp_info_get_status(struct chp_id chpid)
 546 {
 547         int rc;
 548         int bit;
 549
 550         rc = info_update();
 551         if (rc)
 552                 return rc;
 553
 554         bit = info_bit_num(chpid);
 555         mutex_lock(&info_lock);
 556         if (!chp_test_bit(chp_info.recognized, bit))
 557                 rc = CHP_STATUS_NOT_RECOGNIZED;
 558         else if (chp_test_bit(chp_info.configured, bit))
 559                 rc = CHP_STATUS_CONFIGURED;
 560         else if (chp_test_bit(chp_info.standby, bit))
 561                 rc = CHP_STATUS_STANDBY;
 562         else
 563                 rc = CHP_STATUS_RESERVED;
 564         mutex_unlock(&info_lock);
 565
 566         return rc;
 567 }
 568
 569 /* Return configure task for chpid. */
 570 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
 571 {
 572         return chp_cfg_task[chpid.cssid][chpid.id];
 573 }
 574
 575 /* Set configure task for chpid. */
 576 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
 577 {
 578         chp_cfg_task[chpid.cssid][chpid.id] = cfg;
 579 }
 580
 581 /* Perform one configure/deconfigure request. Reschedule work function until
 582  * last request. */
 583 static void cfg_func(struct work_struct *work)
 584 {
 585         struct chp_id chpid;
 586         enum cfg_task_t t;
 587
 588         mutex_lock(&cfg_lock);
 589         t = cfg_none;
 590         chp_id_for_each(&chpid) {
 591                 t = cfg_get_task(chpid);
 592                 if (t != cfg_none) {
 593                         cfg_set_task(chpid, cfg_none);
 594                         break;
 595                 }
 596         }
 597         mutex_unlock(&cfg_lock);
 598
 599         switch (t) {
 600         case cfg_configure:
 601                 sclp_chp_configure(chpid);
 602                 info_expire();
 603                 chsc_chp_online(chpid);
 604                 break;
 605         case cfg_deconfigure:
 606                 sclp_chp_deconfigure(chpid);
 607                 info_expire();
 608                 chsc_chp_offline(chpid);
 609                 break;
 610         case cfg_none:
 611                 /* Get updated information after last change. */
 612                 info_update();
 613                 mutex_lock(&cfg_lock);
 614                 cfg_busy = 0;
 615                 mutex_unlock(&cfg_lock);
 616                 wake_up_interruptible(&cfg_wait_queue);
 617                 return;
 618         }
 619         queue_work(chp_wq, &cfg_work);
 620 }
 621
 622 /**
 623  * chp_cfg_schedule - schedule chpid configuration request
 624  * @chpid - channel-path ID
 625  * @configure - Non-zero for configure, zero for deconfigure
 626  *
 627  * Schedule a channel-path configuration/deconfiguration request.
 628  */
 629 void chp_cfg_schedule(struct chp_id chpid, int configure)
 630 {
 631         CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
 632                       configure);
 633         mutex_lock(&cfg_lock);
 634         cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
 635         cfg_busy = 1;
 636         mutex_unlock(&cfg_lock);
 637         queue_work(chp_wq, &cfg_work);
 638 }
 639
 640 /**
 641  * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
 642  * @chpid - channel-path ID
 643  *
 644  * Cancel an active channel-path deconfiguration request if it has not yet
 645  * been performed.
 646  */
 647 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
 648 {
 649         CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
 650         mutex_lock(&cfg_lock);
 651         if (cfg_get_task(chpid) == cfg_deconfigure)
 652                 cfg_set_task(chpid, cfg_none);
 653         mutex_unlock(&cfg_lock);
 654 }
 655
 656 static int cfg_wait_idle(void)
 657 {
 658         if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
 659                 return -ERESTARTSYS;
 660         return 0;
 661 }
 662
 663 static int __init chp_init(void)
 664 {
 665         struct chp_id chpid;
 666
 667         chp_wq = create_singlethread_workqueue("cio_chp");
 668         if (!chp_wq)
 669                 return -ENOMEM;
 670         INIT_WORK(&cfg_work, cfg_func);
 671         init_waitqueue_head(&cfg_wait_queue);
 672         if (info_update())
 673                 return 0;
 674         /* Register available channel-paths. */
 675         chp_id_for_each(&chpid) {
 676                 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
 677                         chp_new(chpid);
 678         }
 679
 680         return 0;
 681 }
 682
 683 subsys_initcall(chp_init);