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  45 /* Time after which channel-path status may be outdated.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