drivers/s390/cio/css.c

   1 /*
   2  *  drivers/s390/cio/css.c
   3  *  driver for channel subsystem
   4  *
   5  *    Copyright IBM Corp. 2002,2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  */
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/device.h>
  12 #include <linux/slab.h>
  13 #include <linux/errno.h>
  14 #include <linux/list.h>
  15 #include <linux/reboot.h>
  16
  17 #include "../s390mach.h"
  18 #include "css.h"
  19 #include "cio.h"
  20 #include "cio_debug.h"
  21 #include "ioasm.h"
  22 #include "chsc.h"
  23 #include "device.h"
  24 #include "idset.h"
  25 #include "chp.h"
  26
  27 int css_init_done = 0;
  28 static int need_reprobe = 0;
  29 static int max_ssid = 0;
  30
  31 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
  32
  33 int css_characteristics_avail = 0;
  34
  35 int
  36 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
  37 {
  38         struct subchannel_id schid;
  39         int ret;
  40
  41         init_subchannel_id(&schid);
  42         ret = -ENODEV;
  43         do {
  44                 do {
  45                         ret = fn(schid, data);
  46                         if (ret)
  47                                 break;
  48                 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
  49                 schid.sch_no = 0;
  50         } while (schid.ssid++ < max_ssid);
  51         return ret;
  52 }
  53
  54 struct cb_data {
  55         void *data;
  56         struct idset *set;
  57         int (*fn_known_sch)(struct subchannel *, void *);
  58         int (*fn_unknown_sch)(struct subchannel_id, void *);
  59 };
  60
  61 static int call_fn_known_sch(struct device *dev, void *data)
  62 {
  63         struct subchannel *sch = to_subchannel(dev);
  64         struct cb_data *cb = data;
  65         int rc = 0;
  66
  67         idset_sch_del(cb->set, sch->schid);
  68         if (cb->fn_known_sch)
  69                 rc = cb->fn_known_sch(sch, cb->data);
  70         return rc;
  71 }
  72
  73 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
  74 {
  75         struct cb_data *cb = data;
  76         int rc = 0;
  77
  78         if (idset_sch_contains(cb->set, schid))
  79                 rc = cb->fn_unknown_sch(schid, cb->data);
  80         return rc;
  81 }
  82
  83 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
  84                                int (*fn_unknown)(struct subchannel_id,
  85                                void *), void *data)
  86 {
  87         struct cb_data cb;
  88         int rc;
  89
  90         cb.set = idset_sch_new();
  91         if (!cb.set)
  92                 return -ENOMEM;
  93         idset_fill(cb.set);
  94         cb.data = data;
  95         cb.fn_known_sch = fn_known;
  96         cb.fn_unknown_sch = fn_unknown;
  97         /* Process registered subchannels. */
  98         rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
  99         if (rc)
 100                 goto out;
 101         /* Process unregistered subchannels. */
 102         if (fn_unknown)
 103                 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
 104 out:
 105         idset_free(cb.set);
 106
 107         return rc;
 108 }
 109
 110 static struct subchannel *
 111 css_alloc_subchannel(struct subchannel_id schid)
 112 {
 113         struct subchannel *sch;
 114         int ret;
 115
 116         sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
 117         if (sch == NULL)
 118                 return ERR_PTR(-ENOMEM);
 119         ret = cio_validate_subchannel (sch, schid);
 120         if (ret < 0) {
 121                 kfree(sch);
 122                 return ERR_PTR(ret);
 123         }
 124         return sch;
 125 }
 126
 127 static void
 128 css_free_subchannel(struct subchannel *sch)
 129 {
 130         if (sch) {
 131                 /* Reset intparm to zeroes. */
 132                 sch->schib.pmcw.intparm = 0;
 133                 cio_modify(sch);
 134                 kfree(sch->lock);
 135                 kfree(sch);
 136         }
 137 }
 138
 139 static void
 140 css_subchannel_release(struct device *dev)
 141 {
 142         struct subchannel *sch;
 143
 144         sch = to_subchannel(dev);
 145         if (!cio_is_console(sch->schid)) {
 146                 kfree(sch->lock);
 147                 kfree(sch);
 148         }
 149 }
 150
 151 static int css_sch_device_register(struct subchannel *sch)
 152 {
 153         int ret;
 154
 155         mutex_lock(&sch->reg_mutex);
 156         ret = device_register(&sch->dev);
 157         mutex_unlock(&sch->reg_mutex);
 158         return ret;
 159 }
 160
 161 /**
 162  * css_sch_device_unregister - unregister a subchannel
 163  * @sch: subchannel to be unregistered
 164  */
 165 void css_sch_device_unregister(struct subchannel *sch)
 166 {
 167         mutex_lock(&sch->reg_mutex);
 168         device_unregister(&sch->dev);
 169         mutex_unlock(&sch->reg_mutex);
 170 }
 171 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
 172
 173 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
 174 {
 175         int i;
 176         int mask;
 177
 178         memset(ssd, 0, sizeof(struct chsc_ssd_info));
 179         ssd->path_mask = pmcw->pim;
 180         for (i = 0; i < 8; i++) {
 181                 mask = 0x80 >> i;
 182                 if (pmcw->pim & mask) {
 183                         chp_id_init(&ssd->chpid[i]);
 184                         ssd->chpid[i].id = pmcw->chpid[i];
 185                 }
 186         }
 187 }
 188
 189 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
 190 {
 191         int i;
 192         int mask;
 193
 194         for (i = 0; i < 8; i++) {
 195                 mask = 0x80 >> i;
 196                 if (ssd->path_mask & mask)
 197                         if (!chp_is_registered(ssd->chpid[i]))
 198                                 chp_new(ssd->chpid[i]);
 199         }
 200 }
 201
 202 void css_update_ssd_info(struct subchannel *sch)
 203 {
 204         int ret;
 205
 206         if (cio_is_console(sch->schid)) {
 207                 /* Console is initialized too early for functions requiring
 208                  * memory allocation. */
 209                 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
 210         } else {
 211                 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
 212                 if (ret)
 213                         ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
 214                 ssd_register_chpids(&sch->ssd_info);
 215         }
 216 }
 217
 218 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
 219                          char *buf)
 220 {
 221         struct subchannel *sch = to_subchannel(dev);
 222
 223         return sprintf(buf, "%01x\n", sch->st);
 224 }
 225
 226 static DEVICE_ATTR(type, 0444, type_show, NULL);
 227
 228 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 229                              char *buf)
 230 {
 231         struct subchannel *sch = to_subchannel(dev);
 232
 233         return sprintf(buf, "css:t%01X\n", sch->st);
 234 }
 235
 236 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 237
 238 static struct attribute *subch_attrs[] = {
 239         &dev_attr_type.attr,
 240         &dev_attr_modalias.attr,
 241         NULL,
 242 };
 243
 244 static struct attribute_group subch_attr_group = {
 245         .attrs = subch_attrs,
 246 };
 247
 248 static struct attribute_group *default_subch_attr_groups[] = {
 249         &subch_attr_group,
 250         NULL,
 251 };
 252
 253 static int css_register_subchannel(struct subchannel *sch)
 254 {
 255         int ret;
 256
 257         /* Initialize the subchannel structure */
 258         sch->dev.parent = &channel_subsystems[0]->device;
 259         sch->dev.bus = &css_bus_type;
 260         sch->dev.release = &css_subchannel_release;
 261         sch->dev.groups = default_subch_attr_groups;
 262         /*
 263          * We don't want to generate uevents for I/O subchannels that don't
 264          * have a working ccw device behind them since they will be
 265          * unregistered before they can be used anyway, so we delay the add
 266          * uevent until after device recognition was successful.
 267          * Note that we suppress the uevent for all subchannel types;
 268          * the subchannel driver can decide itself when it wants to inform
 269          * userspace of its existence.
 270          */
 271         sch->dev.uevent_suppress = 1;
 272         css_update_ssd_info(sch);
 273         /* make it known to the system */
 274         ret = css_sch_device_register(sch);
 275         if (ret) {
 276                 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
 277                               sch->schid.ssid, sch->schid.sch_no, ret);
 278                 return ret;
 279         }
 280         if (!sch->driver) {
 281                 /*
 282                  * No driver matched. Generate the uevent now so that
 283                  * a fitting driver module may be loaded based on the
 284                  * modalias.
 285                  */
 286                 sch->dev.uevent_suppress = 0;
 287                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 288         }
 289         return ret;
 290 }
 291
 292 int css_probe_device(struct subchannel_id schid)
 293 {
 294         int ret;
 295         struct subchannel *sch;
 296
 297         sch = css_alloc_subchannel(schid);
 298         if (IS_ERR(sch))
 299                 return PTR_ERR(sch);
 300         ret = css_register_subchannel(sch);
 301         if (ret)
 302                 css_free_subchannel(sch);
 303         return ret;
 304 }
 305
 306 static int
 307 check_subchannel(struct device * dev, void * data)
 308 {
 309         struct subchannel *sch;
 310         struct subchannel_id *schid = data;
 311
 312         sch = to_subchannel(dev);
 313         return schid_equal(&sch->schid, schid);
 314 }
 315
 316 struct subchannel *
 317 get_subchannel_by_schid(struct subchannel_id schid)
 318 {
 319         struct device *dev;
 320
 321         dev = bus_find_device(&css_bus_type, NULL,
 322                               &schid, check_subchannel);
 323
 324         return dev ? to_subchannel(dev) : NULL;
 325 }
 326
 327 /**
 328  * css_sch_is_valid() - check if a subchannel is valid
 329  * @schib: subchannel information block for the subchannel
 330  */
 331 int css_sch_is_valid(struct schib *schib)
 332 {
 333         if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
 334                 return 0;
 335         return 1;
 336 }
 337 EXPORT_SYMBOL_GPL(css_sch_is_valid);
 338
 339 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
 340 {
 341         struct schib schib;
 342
 343         if (!slow) {
 344                 /* Will be done on the slow path. */
 345                 return -EAGAIN;
 346         }
 347         if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
 348                 /* Unusable - ignore. */
 349                 return 0;
 350         }
 351         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
 352                          "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
 353
 354         return css_probe_device(schid);
 355 }
 356
 357 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
 358 {
 359         int ret = 0;
 360
 361         if (sch->driver) {
 362                 if (sch->driver->sch_event)
 363                         ret = sch->driver->sch_event(sch, slow);
 364                 else
 365                         dev_dbg(&sch->dev,
 366                                 "Got subchannel machine check but "
 367                                 "no sch_event handler provided.\n");
 368         }
 369         return ret;
 370 }
 371
 372 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
 373 {
 374         struct subchannel *sch;
 375         int ret;
 376
 377         sch = get_subchannel_by_schid(schid);
 378         if (sch) {
 379                 ret = css_evaluate_known_subchannel(sch, slow);
 380                 put_device(&sch->dev);
 381         } else
 382                 ret = css_evaluate_new_subchannel(schid, slow);
 383         if (ret == -EAGAIN)
 384                 css_schedule_eval(schid);
 385 }
 386
 387 static struct idset *slow_subchannel_set;
 388 static spinlock_t slow_subchannel_lock;
 389
 390 static int __init slow_subchannel_init(void)
 391 {
 392         spin_lock_init(&slow_subchannel_lock);
 393         slow_subchannel_set = idset_sch_new();
 394         if (!slow_subchannel_set) {
 395                 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
 396                 return -ENOMEM;
 397         }
 398         return 0;
 399 }
 400
 401 static int slow_eval_known_fn(struct subchannel *sch, void *data)
 402 {
 403         int eval;
 404         int rc;
 405
 406         spin_lock_irq(&slow_subchannel_lock);
 407         eval = idset_sch_contains(slow_subchannel_set, sch->schid);
 408         idset_sch_del(slow_subchannel_set, sch->schid);
 409         spin_unlock_irq(&slow_subchannel_lock);
 410         if (eval) {
 411                 rc = css_evaluate_known_subchannel(sch, 1);
 412                 if (rc == -EAGAIN)
 413                         css_schedule_eval(sch->schid);
 414         }
 415         return 0;
 416 }
 417
 418 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
 419 {
 420         int eval;
 421         int rc = 0;
 422
 423         spin_lock_irq(&slow_subchannel_lock);
 424         eval = idset_sch_contains(slow_subchannel_set, schid);
 425         idset_sch_del(slow_subchannel_set, schid);
 426         spin_unlock_irq(&slow_subchannel_lock);
 427         if (eval) {
 428                 rc = css_evaluate_new_subchannel(schid, 1);
 429                 switch (rc) {
 430                 case -EAGAIN:
 431                         css_schedule_eval(schid);
 432                         rc = 0;
 433                         break;
 434                 case -ENXIO:
 435                 case -ENOMEM:
 436                 case -EIO:
 437                         /* These should abort looping */
 438                         break;
 439                 default:
 440                         rc = 0;
 441                 }
 442         }
 443         return rc;
 444 }
 445
 446 static void css_slow_path_func(struct work_struct *unused)
 447 {
 448         CIO_TRACE_EVENT(4, "slowpath");
 449         for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
 450                                    NULL);
 451 }
 452
 453 static DECLARE_WORK(slow_path_work, css_slow_path_func);
 454 struct workqueue_struct *slow_path_wq;
 455
 456 void css_schedule_eval(struct subchannel_id schid)
 457 {
 458         unsigned long flags;
 459
 460         spin_lock_irqsave(&slow_subchannel_lock, flags);
 461         idset_sch_add(slow_subchannel_set, schid);
 462         queue_work(slow_path_wq, &slow_path_work);
 463         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 464 }
 465
 466 void css_schedule_eval_all(void)
 467 {
 468         unsigned long flags;
 469
 470         spin_lock_irqsave(&slow_subchannel_lock, flags);
 471         idset_fill(slow_subchannel_set);
 472         queue_work(slow_path_wq, &slow_path_work);
 473         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 474 }
 475
 476 void css_wait_for_slow_path(void)
 477 {
 478         flush_workqueue(ccw_device_notify_work);
 479         flush_workqueue(slow_path_wq);
 480 }
 481
 482 /* Reprobe subchannel if unregistered. */
 483 static int reprobe_subchannel(struct subchannel_id schid, void *data)
 484 {
 485         int ret;
 486
 487         CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
 488                       schid.ssid, schid.sch_no);
 489         if (need_reprobe)
 490                 return -EAGAIN;
 491
 492         ret = css_probe_device(schid);
 493         switch (ret) {
 494         case 0:
 495                 break;
 496         case -ENXIO:
 497         case -ENOMEM:
 498         case -EIO:
 499                 /* These should abort looping */
 500                 break;
 501         default:
 502                 ret = 0;
 503         }
 504
 505         return ret;
 506 }
 507
 508 /* Work function used to reprobe all unregistered subchannels. */
 509 static void reprobe_all(struct work_struct *unused)
 510 {
 511         int ret;
 512
 513         CIO_MSG_EVENT(4, "reprobe start\n");
 514
 515         need_reprobe = 0;
 516         /* Make sure initial subchannel scan is done. */
 517         wait_event(ccw_device_init_wq,
 518                    atomic_read(&ccw_device_init_count) == 0);
 519         ret = for_each_subchannel_staged(NULL, reprobe_subchannel, NULL);
 520
 521         CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
 522                       need_reprobe);
 523 }
 524
 525 static DECLARE_WORK(css_reprobe_work, reprobe_all);
 526
 527 /* Schedule reprobing of all unregistered subchannels. */
 528 void css_schedule_reprobe(void)
 529 {
 530         need_reprobe = 1;
 531         queue_work(slow_path_wq, &css_reprobe_work);
 532 }
 533
 534 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 535
 536 /*
 537  * Called from the machine check handler for subchannel report words.
 538  */
 539 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 540 {
 541         struct subchannel_id mchk_schid;
 542
 543         if (overflow) {
 544                 css_schedule_eval_all();
 545                 return;
 546         }
 547         CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
 548                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 549                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 550                       crw0->erc, crw0->rsid);
 551         if (crw1)
 552                 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
 553                               "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 554                               crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
 555                               crw1->anc, crw1->erc, crw1->rsid);
 556         init_subchannel_id(&mchk_schid);
 557         mchk_schid.sch_no = crw0->rsid;
 558         if (crw1)
 559                 mchk_schid.ssid = (crw1->rsid >> 8) & 3;
 560
 561         /*
 562          * Since we are always presented with IPI in the CRW, we have to
 563          * use stsch() to find out if the subchannel in question has come
 564          * or gone.
 565          */
 566         css_evaluate_subchannel(mchk_schid, 0);
 567 }
 568
 569 static int __init
 570 __init_channel_subsystem(struct subchannel_id schid, void *data)
 571 {
 572         struct subchannel *sch;
 573         int ret;
 574
 575         if (cio_is_console(schid))
 576                 sch = cio_get_console_subchannel();
 577         else {
 578                 sch = css_alloc_subchannel(schid);
 579                 if (IS_ERR(sch))
 580                         ret = PTR_ERR(sch);
 581                 else
 582                         ret = 0;
 583                 switch (ret) {
 584                 case 0:
 585                         break;
 586                 case -ENOMEM:
 587                         panic("Out of memory in init_channel_subsystem\n");
 588                 /* -ENXIO: no more subchannels. */
 589                 case -ENXIO:
 590                         return ret;
 591                 /* -EIO: this subchannel set not supported. */
 592                 case -EIO:
 593                         return ret;
 594                 default:
 595                         return 0;
 596                 }
 597         }
 598         /*
 599          * We register ALL valid subchannels in ioinfo, even those
 600          * that have been present before init_channel_subsystem.
 601          * These subchannels can't have been registered yet (kmalloc
 602          * not working) so we do it now. This is true e.g. for the
 603          * console subchannel.
 604          */
 605         css_register_subchannel(sch);
 606         return 0;
 607 }
 608
 609 static void __init
 610 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
 611 {
 612         if (css_characteristics_avail && css_general_characteristics.mcss) {
 613                 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
 614                 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
 615         } else {
 616 #ifdef CONFIG_SMP
 617                 css->global_pgid.pgid_high.cpu_addr = hard_smp_processor_id();
 618 #else
 619                 css->global_pgid.pgid_high.cpu_addr = 0;
 620 #endif
 621         }
 622         css->global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
 623         css->global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
 624         css->global_pgid.tod_high = tod_high;
 625
 626 }
 627
 628 static void
 629 channel_subsystem_release(struct device *dev)
 630 {
 631         struct channel_subsystem *css;
 632
 633         css = to_css(dev);
 634         mutex_destroy(&css->mutex);
 635         kfree(css);
 636 }
 637
 638 static ssize_t
 639 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
 640                    char *buf)
 641 {
 642         struct channel_subsystem *css = to_css(dev);
 643         int ret;
 644
 645         if (!css)
 646                 return 0;
 647         mutex_lock(&css->mutex);
 648         ret = sprintf(buf, "%x\n", css->cm_enabled);
 649         mutex_unlock(&css->mutex);
 650         return ret;
 651 }
 652
 653 static ssize_t
 654 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
 655                     const char *buf, size_t count)
 656 {
 657         struct channel_subsystem *css = to_css(dev);
 658         int ret;
 659         unsigned long val;
 660
 661         ret = strict_strtoul(buf, 16, &val);
 662         if (ret)
 663                 return ret;
 664         mutex_lock(&css->mutex);
 665         switch (val) {
 666         case 0:
 667                 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
 668                 break;
 669         case 1:
 670                 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
 671                 break;
 672         default:
 673                 ret = -EINVAL;
 674         }
 675         mutex_unlock(&css->mutex);
 676         return ret < 0 ? ret : count;
 677 }
 678
 679 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
 680
 681 static int __init setup_css(int nr)
 682 {
 683         u32 tod_high;
 684         int ret;
 685         struct channel_subsystem *css;
 686
 687         css = channel_subsystems[nr];
 688         memset(css, 0, sizeof(struct channel_subsystem));
 689         css->pseudo_subchannel =
 690                 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
 691         if (!css->pseudo_subchannel)
 692                 return -ENOMEM;
 693         css->pseudo_subchannel->dev.parent = &css->device;
 694         css->pseudo_subchannel->dev.release = css_subchannel_release;
 695         sprintf(css->pseudo_subchannel->dev.bus_id, "defunct");
 696         ret = cio_create_sch_lock(css->pseudo_subchannel);
 697         if (ret) {
 698                 kfree(css->pseudo_subchannel);
 699                 return ret;
 700         }
 701         mutex_init(&css->mutex);
 702         css->valid = 1;
 703         css->cssid = nr;
 704         sprintf(css->device.bus_id, "css%x", nr);
 705         css->device.release = channel_subsystem_release;
 706         tod_high = (u32) (get_clock() >> 32);
 707         css_generate_pgid(css, tod_high);
 708         return 0;
 709 }
 710
 711 static int css_reboot_event(struct notifier_block *this,
 712                             unsigned long event,
 713                             void *ptr)
 714 {
 715         int ret, i;
 716
 717         ret = NOTIFY_DONE;
 718         for (i = 0; i <= __MAX_CSSID; i++) {
 719                 struct channel_subsystem *css;
 720
 721                 css = channel_subsystems[i];
 722                 mutex_lock(&css->mutex);
 723                 if (css->cm_enabled)
 724                         if (chsc_secm(css, 0))
 725                                 ret = NOTIFY_BAD;
 726                 mutex_unlock(&css->mutex);
 727         }
 728
 729         return ret;
 730 }
 731
 732 static struct notifier_block css_reboot_notifier = {
 733         .notifier_call = css_reboot_event,
 734 };
 735
 736 /*
 737  * Now that the driver core is running, we can setup our channel subsystem.
 738  * The struct subchannel's are created during probing (except for the
 739  * static console subchannel).
 740  */
 741 static int __init
 742 init_channel_subsystem (void)
 743 {
 744         int ret, i;
 745
 746         ret = chsc_determine_css_characteristics();
 747         if (ret == -ENOMEM)
 748                 goto out; /* No need to continue. */
 749         if (ret == 0)
 750                 css_characteristics_avail = 1;
 751
 752         ret = chsc_alloc_sei_area();
 753         if (ret)
 754                 goto out;
 755
 756         ret = slow_subchannel_init();
 757         if (ret)
 758                 goto out;
 759
 760         ret = s390_register_crw_handler(CRW_RSC_SCH, css_process_crw);
 761         if (ret)
 762                 goto out;
 763
 764         if ((ret = bus_register(&css_bus_type)))
 765                 goto out;
 766
 767         /* Try to enable MSS. */
 768         ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
 769         switch (ret) {
 770         case 0: /* Success. */
 771                 max_ssid = __MAX_SSID;
 772                 break;
 773         case -ENOMEM:
 774                 goto out_bus;
 775         default:
 776                 max_ssid = 0;
 777         }
 778         /* Setup css structure. */
 779         for (i = 0; i <= __MAX_CSSID; i++) {
 780                 struct channel_subsystem *css;
 781
 782                 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
 783                 if (!css) {
 784                         ret = -ENOMEM;
 785                         goto out_unregister;
 786                 }
 787                 channel_subsystems[i] = css;
 788                 ret = setup_css(i);
 789                 if (ret)
 790                         goto out_free;
 791                 ret = device_register(&css->device);
 792                 if (ret)
 793                         goto out_free_all;
 794                 if (css_characteristics_avail &&
 795                     css_chsc_characteristics.secm) {
 796                         ret = device_create_file(&css->device,
 797                                                  &dev_attr_cm_enable);
 798                         if (ret)
 799                                 goto out_device;
 800                 }
 801                 ret = device_register(&css->pseudo_subchannel->dev);
 802                 if (ret)
 803                         goto out_file;
 804         }
 805         ret = register_reboot_notifier(&css_reboot_notifier);
 806         if (ret)
 807                 goto out_pseudo;
 808         css_init_done = 1;
 809
 810         ctl_set_bit(6, 28);
 811
 812         for_each_subchannel(__init_channel_subsystem, NULL);
 813         return 0;
 814 out_pseudo:
 815         device_unregister(&channel_subsystems[i]->pseudo_subchannel->dev);
 816 out_file:
 817         device_remove_file(&channel_subsystems[i]->device,
 818                            &dev_attr_cm_enable);
 819 out_device:
 820         device_unregister(&channel_subsystems[i]->device);
 821 out_free_all:
 822         kfree(channel_subsystems[i]->pseudo_subchannel->lock);
 823         kfree(channel_subsystems[i]->pseudo_subchannel);
 824 out_free:
 825         kfree(channel_subsystems[i]);
 826 out_unregister:
 827         while (i > 0) {
 828                 struct channel_subsystem *css;
 829
 830                 i--;
 831                 css = channel_subsystems[i];
 832                 device_unregister(&css->pseudo_subchannel->dev);
 833                 if (css_characteristics_avail && css_chsc_characteristics.secm)
 834                         device_remove_file(&css->device,
 835                                            &dev_attr_cm_enable);
 836                 device_unregister(&css->device);
 837         }
 838 out_bus:
 839         bus_unregister(&css_bus_type);
 840 out:
 841         s390_unregister_crw_handler(CRW_RSC_CSS);
 842         chsc_free_sei_area();
 843         kfree(slow_subchannel_set);
 844         printk(KERN_WARNING"cio: failed to initialize css driver (%d)!\n",
 845                ret);
 846         return ret;
 847 }
 848
 849 int sch_is_pseudo_sch(struct subchannel *sch)
 850 {
 851         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
 852 }
 853
 854 /*
 855  * find a driver for a subchannel. They identify by the subchannel
 856  * type with the exception that the console subchannel driver has its own
 857  * subchannel type although the device is an i/o subchannel
 858  */
 859 static int
 860 css_bus_match (struct device *dev, struct device_driver *drv)
 861 {
 862         struct subchannel *sch = to_subchannel(dev);
 863         struct css_driver *driver = to_cssdriver(drv);
 864
 865         if (sch->st == driver->subchannel_type)
 866                 return 1;
 867
 868         return 0;
 869 }
 870
 871 static int css_probe(struct device *dev)
 872 {
 873         struct subchannel *sch;
 874         int ret;
 875
 876         sch = to_subchannel(dev);
 877         sch->driver = to_cssdriver(dev->driver);
 878         ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
 879         if (ret)
 880                 sch->driver = NULL;
 881         return ret;
 882 }
 883
 884 static int css_remove(struct device *dev)
 885 {
 886         struct subchannel *sch;
 887         int ret;
 888
 889         sch = to_subchannel(dev);
 890         ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
 891         sch->driver = NULL;
 892         return ret;
 893 }
 894
 895 static void css_shutdown(struct device *dev)
 896 {
 897         struct subchannel *sch;
 898
 899         sch = to_subchannel(dev);
 900         if (sch->driver && sch->driver->shutdown)
 901                 sch->driver->shutdown(sch);
 902 }
 903
 904 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
 905 {
 906         struct subchannel *sch = to_subchannel(dev);
 907         int ret;
 908
 909         ret = add_uevent_var(env, "ST=%01X", sch->st);
 910         if (ret)
 911                 return ret;
 912         ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
 913         return ret;
 914 }
 915
 916 struct bus_type css_bus_type = {
 917         .name     = "css",
 918         .match    = css_bus_match,
 919         .probe    = css_probe,
 920         .remove   = css_remove,
 921         .shutdown = css_shutdown,
 922         .uevent   = css_uevent,
 923 };
 924
 925 /**
 926  * css_driver_register - register a css driver
 927  * @cdrv: css driver to register
 928  *
 929  * This is mainly a wrapper around driver_register that sets name
 930  * and bus_type in the embedded struct device_driver correctly.
 931  */
 932 int css_driver_register(struct css_driver *cdrv)
 933 {
 934         cdrv->drv.name = cdrv->name;
 935         cdrv->drv.bus = &css_bus_type;
 936         cdrv->drv.owner = cdrv->owner;
 937         return driver_register(&cdrv->drv);
 938 }
 939 EXPORT_SYMBOL_GPL(css_driver_register);
 940
 941 /**
 942  * css_driver_unregister - unregister a css driver
 943  * @cdrv: css driver to unregister
 944  *
 945  * This is a wrapper around driver_unregister.
 946  */
 947 void css_driver_unregister(struct css_driver *cdrv)
 948 {
 949         driver_unregister(&cdrv->drv);
 950 }
 951 EXPORT_SYMBOL_GPL(css_driver_unregister);
 952
 953 subsys_initcall(init_channel_subsystem);
 954
 955 MODULE_LICENSE("GPL");
 956 EXPORT_SYMBOL(css_bus_type);
 957 EXPORT_SYMBOL_GPL(css_characteristics_avail);