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   1 /*
   2  * driver for channel subsystem
   3  *
   4  * Copyright IBM Corp. 2002, 2009
   5  *
   6  * Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *            Cornelia Huck (cornelia.huck@de.ibm.com)
   8  */
   9
  10 #define KMSG_COMPONENT "cio"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/device.h>
  16 #include <linux/slab.h>
  17 #include <linux/errno.h>
  18 #include <linux/list.h>
  19 #include <linux/reboot.h>
  20 #include <linux/suspend.h>
  21 #include <asm/isc.h>
  22 #include <asm/crw.h>
  23
  24 #include "css.h"
  25 #include "cio.h"
  26 #include "cio_debug.h"
  27 #include "ioasm.h"
  28 #include "chsc.h"
  29 #include "device.h"
  30 #include "idset.h"
  31 #include "chp.h"
  32
  33 int css_init_done = 0;
  34 int max_ssid;
  35
  36 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
  37
  38 int
  39 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
  40 {
  41         struct subchannel_id schid;
  42         int ret;
  43
  44         init_subchannel_id(&schid);
  45         ret = -ENODEV;
  46         do {
  47                 do {
  48                         ret = fn(schid, data);
  49                         if (ret)
  50                                 break;
  51                 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
  52                 schid.sch_no = 0;
  53         } while (schid.ssid++ < max_ssid);
  54         return ret;
  55 }
  56
  57 struct cb_data {
  58         void *data;
  59         struct idset *set;
  60         int (*fn_known_sch)(struct subchannel *, void *);
  61         int (*fn_unknown_sch)(struct subchannel_id, void *);
  62 };
  63
  64 static int call_fn_known_sch(struct device *dev, void *data)
  65 {
  66         struct subchannel *sch = to_subchannel(dev);
  67         struct cb_data *cb = data;
  68         int rc = 0;
  69
  70         idset_sch_del(cb->set, sch->schid);
  71         if (cb->fn_known_sch)
  72                 rc = cb->fn_known_sch(sch, cb->data);
  73         return rc;
  74 }
  75
  76 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
  77 {
  78         struct cb_data *cb = data;
  79         int rc = 0;
  80
  81         if (idset_sch_contains(cb->set, schid))
  82                 rc = cb->fn_unknown_sch(schid, cb->data);
  83         return rc;
  84 }
  85
  86 static int call_fn_all_sch(struct subchannel_id schid, void *data)
  87 {
  88         struct cb_data *cb = data;
  89         struct subchannel *sch;
  90         int rc = 0;
  91
  92         sch = get_subchannel_by_schid(schid);
  93         if (sch) {
  94                 if (cb->fn_known_sch)
  95                         rc = cb->fn_known_sch(sch, cb->data);
  96                 put_device(&sch->dev);
  97         } else {
  98                 if (cb->fn_unknown_sch)
  99                         rc = cb->fn_unknown_sch(schid, cb->data);
 100         }
 101
 102         return rc;
 103 }
 104
 105 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
 106                                int (*fn_unknown)(struct subchannel_id,
 107                                void *), void *data)
 108 {
 109         struct cb_data cb;
 110         int rc;
 111
 112         cb.data = data;
 113         cb.fn_known_sch = fn_known;
 114         cb.fn_unknown_sch = fn_unknown;
 115
 116         cb.set = idset_sch_new();
 117         if (!cb.set)
 118                 /* fall back to brute force scanning in case of oom */
 119                 return for_each_subchannel(call_fn_all_sch, &cb);
 120
 121         idset_fill(cb.set);
 122
 123         /* Process registered subchannels. */
 124         rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
 125         if (rc)
 126                 goto out;
 127         /* Process unregistered subchannels. */
 128         if (fn_unknown)
 129                 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
 130 out:
 131         idset_free(cb.set);
 132
 133         return rc;
 134 }
 135
 136 static struct subchannel *
 137 css_alloc_subchannel(struct subchannel_id schid)
 138 {
 139         struct subchannel *sch;
 140         int ret;
 141
 142         sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
 143         if (sch == NULL)
 144                 return ERR_PTR(-ENOMEM);
 145         ret = cio_validate_subchannel (sch, schid);
 146         if (ret < 0) {
 147                 kfree(sch);
 148                 return ERR_PTR(ret);
 149         }
 150         return sch;
 151 }
 152
 153 static void
 154 css_subchannel_release(struct device *dev)
 155 {
 156         struct subchannel *sch;
 157
 158         sch = to_subchannel(dev);
 159         if (!cio_is_console(sch->schid)) {
 160                 /* Reset intparm to zeroes. */
 161                 sch->config.intparm = 0;
 162                 cio_commit_config(sch);
 163                 kfree(sch->lock);
 164                 kfree(sch);
 165         }
 166 }
 167
 168 static int css_sch_device_register(struct subchannel *sch)
 169 {
 170         int ret;
 171
 172         mutex_lock(&sch->reg_mutex);
 173         dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
 174                      sch->schid.sch_no);
 175         ret = device_register(&sch->dev);
 176         mutex_unlock(&sch->reg_mutex);
 177         return ret;
 178 }
 179
 180 /**
 181  * css_sch_device_unregister - unregister a subchannel
 182  * @sch: subchannel to be unregistered
 183  */
 184 void css_sch_device_unregister(struct subchannel *sch)
 185 {
 186         mutex_lock(&sch->reg_mutex);
 187         if (device_is_registered(&sch->dev))
 188                 device_unregister(&sch->dev);
 189         mutex_unlock(&sch->reg_mutex);
 190 }
 191 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
 192
 193 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
 194 {
 195         int i;
 196         int mask;
 197
 198         memset(ssd, 0, sizeof(struct chsc_ssd_info));
 199         ssd->path_mask = pmcw->pim;
 200         for (i = 0; i < 8; i++) {
 201                 mask = 0x80 >> i;
 202                 if (pmcw->pim & mask) {
 203                         chp_id_init(&ssd->chpid[i]);
 204                         ssd->chpid[i].id = pmcw->chpid[i];
 205                 }
 206         }
 207 }
 208
 209 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
 210 {
 211         int i;
 212         int mask;
 213
 214         for (i = 0; i < 8; i++) {
 215                 mask = 0x80 >> i;
 216                 if (ssd->path_mask & mask)
 217                         if (!chp_is_registered(ssd->chpid[i]))
 218                                 chp_new(ssd->chpid[i]);
 219         }
 220 }
 221
 222 void css_update_ssd_info(struct subchannel *sch)
 223 {
 224         int ret;
 225
 226         if (cio_is_console(sch->schid)) {
 227                 /* Console is initialized too early for functions requiring
 228                  * memory allocation. */
 229                 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
 230         } else {
 231                 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
 232                 if (ret)
 233                         ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
 234                 ssd_register_chpids(&sch->ssd_info);
 235         }
 236 }
 237
 238 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
 239                          char *buf)
 240 {
 241         struct subchannel *sch = to_subchannel(dev);
 242
 243         return sprintf(buf, "%01x\n", sch->st);
 244 }
 245
 246 static DEVICE_ATTR(type, 0444, type_show, NULL);
 247
 248 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 249                              char *buf)
 250 {
 251         struct subchannel *sch = to_subchannel(dev);
 252
 253         return sprintf(buf, "css:t%01X\n", sch->st);
 254 }
 255
 256 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 257
 258 static struct attribute *subch_attrs[] = {
 259         &dev_attr_type.attr,
 260         &dev_attr_modalias.attr,
 261         NULL,
 262 };
 263
 264 static struct attribute_group subch_attr_group = {
 265         .attrs = subch_attrs,
 266 };
 267
 268 static const struct attribute_group *default_subch_attr_groups[] = {
 269         &subch_attr_group,
 270         NULL,
 271 };
 272
 273 static int css_register_subchannel(struct subchannel *sch)
 274 {
 275         int ret;
 276
 277         /* Initialize the subchannel structure */
 278         sch->dev.parent = &channel_subsystems[0]->device;
 279         sch->dev.bus = &css_bus_type;
 280         sch->dev.release = &css_subchannel_release;
 281         sch->dev.groups = default_subch_attr_groups;
 282         /*
 283          * We don't want to generate uevents for I/O subchannels that don't
 284          * have a working ccw device behind them since they will be
 285          * unregistered before they can be used anyway, so we delay the add
 286          * uevent until after device recognition was successful.
 287          * Note that we suppress the uevent for all subchannel types;
 288          * the subchannel driver can decide itself when it wants to inform
 289          * userspace of its existence.
 290          */
 291         dev_set_uevent_suppress(&sch->dev, 1);
 292         css_update_ssd_info(sch);
 293         /* make it known to the system */
 294         ret = css_sch_device_register(sch);
 295         if (ret) {
 296                 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
 297                               sch->schid.ssid, sch->schid.sch_no, ret);
 298                 return ret;
 299         }
 300         if (!sch->driver) {
 301                 /*
 302                  * No driver matched. Generate the uevent now so that
 303                  * a fitting driver module may be loaded based on the
 304                  * modalias.
 305                  */
 306                 dev_set_uevent_suppress(&sch->dev, 0);
 307                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 308         }
 309         return ret;
 310 }
 311
 312 int css_probe_device(struct subchannel_id schid)
 313 {
 314         int ret;
 315         struct subchannel *sch;
 316
 317         if (cio_is_console(schid))
 318                 sch = cio_get_console_subchannel();
 319         else {
 320                 sch = css_alloc_subchannel(schid);
 321                 if (IS_ERR(sch))
 322                         return PTR_ERR(sch);
 323         }
 324         ret = css_register_subchannel(sch);
 325         if (ret) {
 326                 if (!cio_is_console(schid))
 327                         put_device(&sch->dev);
 328         }
 329         return ret;
 330 }
 331
 332 static int
 333 check_subchannel(struct device * dev, void * data)
 334 {
 335         struct subchannel *sch;
 336         struct subchannel_id *schid = data;
 337
 338         sch = to_subchannel(dev);
 339         return schid_equal(&sch->schid, schid);
 340 }
 341
 342 struct subchannel *
 343 get_subchannel_by_schid(struct subchannel_id schid)
 344 {
 345         struct device *dev;
 346
 347         dev = bus_find_device(&css_bus_type, NULL,
 348                               &schid, check_subchannel);
 349
 350         return dev ? to_subchannel(dev) : NULL;
 351 }
 352
 353 /**
 354  * css_sch_is_valid() - check if a subchannel is valid
 355  * @schib: subchannel information block for the subchannel
 356  */
 357 int css_sch_is_valid(struct schib *schib)
 358 {
 359         if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
 360                 return 0;
 361         if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
 362                 return 0;
 363         return 1;
 364 }
 365 EXPORT_SYMBOL_GPL(css_sch_is_valid);
 366
 367 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
 368 {
 369         struct schib schib;
 370
 371         if (!slow) {
 372                 /* Will be done on the slow path. */
 373                 return -EAGAIN;
 374         }
 375         if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
 376                 /* Unusable - ignore. */
 377                 return 0;
 378         }
 379         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
 380                          "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
 381
 382         return css_probe_device(schid);
 383 }
 384
 385 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
 386 {
 387         int ret = 0;
 388
 389         if (sch->driver) {
 390                 if (sch->driver->sch_event)
 391                         ret = sch->driver->sch_event(sch, slow);
 392                 else
 393                         dev_dbg(&sch->dev,
 394                                 "Got subchannel machine check but "
 395                                 "no sch_event handler provided.\n");
 396         }
 397         return ret;
 398 }
 399
 400 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
 401 {
 402         struct subchannel *sch;
 403         int ret;
 404
 405         sch = get_subchannel_by_schid(schid);
 406         if (sch) {
 407                 ret = css_evaluate_known_subchannel(sch, slow);
 408                 put_device(&sch->dev);
 409         } else
 410                 ret = css_evaluate_new_subchannel(schid, slow);
 411         if (ret == -EAGAIN)
 412                 css_schedule_eval(schid);
 413 }
 414
 415 static struct idset *slow_subchannel_set;
 416 static spinlock_t slow_subchannel_lock;
 417 static wait_queue_head_t css_eval_wq;
 418 static atomic_t css_eval_scheduled;
 419
 420 static int __init slow_subchannel_init(void)
 421 {
 422         spin_lock_init(&slow_subchannel_lock);
 423         atomic_set(&css_eval_scheduled, 0);
 424         init_waitqueue_head(&css_eval_wq);
 425         slow_subchannel_set = idset_sch_new();
 426         if (!slow_subchannel_set) {
 427                 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
 428                 return -ENOMEM;
 429         }
 430         return 0;
 431 }
 432
 433 static int slow_eval_known_fn(struct subchannel *sch, void *data)
 434 {
 435         int eval;
 436         int rc;
 437
 438         spin_lock_irq(&slow_subchannel_lock);
 439         eval = idset_sch_contains(slow_subchannel_set, sch->schid);
 440         idset_sch_del(slow_subchannel_set, sch->schid);
 441         spin_unlock_irq(&slow_subchannel_lock);
 442         if (eval) {
 443                 rc = css_evaluate_known_subchannel(sch, 1);
 444                 if (rc == -EAGAIN)
 445                         css_schedule_eval(sch->schid);
 446         }
 447         return 0;
 448 }
 449
 450 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
 451 {
 452         int eval;
 453         int rc = 0;
 454
 455         spin_lock_irq(&slow_subchannel_lock);
 456         eval = idset_sch_contains(slow_subchannel_set, schid);
 457         idset_sch_del(slow_subchannel_set, schid);
 458         spin_unlock_irq(&slow_subchannel_lock);
 459         if (eval) {
 460                 rc = css_evaluate_new_subchannel(schid, 1);
 461                 switch (rc) {
 462                 case -EAGAIN:
 463                         css_schedule_eval(schid);
 464                         rc = 0;
 465                         break;
 466                 case -ENXIO:
 467                 case -ENOMEM:
 468                 case -EIO:
 469                         /* These should abort looping */
 470                         break;
 471                 default:
 472                         rc = 0;
 473                 }
 474         }
 475         return rc;
 476 }
 477
 478 static void css_slow_path_func(struct work_struct *unused)
 479 {
 480         unsigned long flags;
 481
 482         CIO_TRACE_EVENT(4, "slowpath");
 483         for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
 484                                    NULL);
 485         spin_lock_irqsave(&slow_subchannel_lock, flags);
 486         if (idset_is_empty(slow_subchannel_set)) {
 487                 atomic_set(&css_eval_scheduled, 0);
 488                 wake_up(&css_eval_wq);
 489         }
 490         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 491 }
 492
 493 static DECLARE_WORK(slow_path_work, css_slow_path_func);
 494 struct workqueue_struct *slow_path_wq;
 495
 496 void css_schedule_eval(struct subchannel_id schid)
 497 {
 498         unsigned long flags;
 499
 500         spin_lock_irqsave(&slow_subchannel_lock, flags);
 501         idset_sch_add(slow_subchannel_set, schid);
 502         atomic_set(&css_eval_scheduled, 1);
 503         queue_work(slow_path_wq, &slow_path_work);
 504         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 505 }
 506
 507 void css_schedule_eval_all(void)
 508 {
 509         unsigned long flags;
 510
 511         spin_lock_irqsave(&slow_subchannel_lock, flags);
 512         idset_fill(slow_subchannel_set);
 513         atomic_set(&css_eval_scheduled, 1);
 514         queue_work(slow_path_wq, &slow_path_work);
 515         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 516 }
 517
 518 static int __unset_registered(struct device *dev, void *data)
 519 {
 520         struct idset *set = data;
 521         struct subchannel *sch = to_subchannel(dev);
 522
 523         idset_sch_del(set, sch->schid);
 524         return 0;
 525 }
 526
 527 void css_schedule_eval_all_unreg(void)
 528 {
 529         unsigned long flags;
 530         struct idset *unreg_set;
 531
 532         /* Find unregistered subchannels. */
 533         unreg_set = idset_sch_new();
 534         if (!unreg_set) {
 535                 /* Fallback. */
 536                 css_schedule_eval_all();
 537                 return;
 538         }
 539         idset_fill(unreg_set);
 540         bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
 541         /* Apply to slow_subchannel_set. */
 542         spin_lock_irqsave(&slow_subchannel_lock, flags);
 543         idset_add_set(slow_subchannel_set, unreg_set);
 544         atomic_set(&css_eval_scheduled, 1);
 545         queue_work(slow_path_wq, &slow_path_work);
 546         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 547         idset_free(unreg_set);
 548 }
 549
 550 void css_wait_for_slow_path(void)
 551 {
 552         flush_workqueue(slow_path_wq);
 553 }
 554
 555 /* Schedule reprobing of all unregistered subchannels. */
 556 void css_schedule_reprobe(void)
 557 {
 558         css_schedule_eval_all_unreg();
 559 }
 560 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 561
 562 /*
 563  * Called from the machine check handler for subchannel report words.
 564  */
 565 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 566 {
 567         struct subchannel_id mchk_schid;
 568
 569         if (overflow) {
 570                 css_schedule_eval_all();
 571                 return;
 572         }
 573         CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
 574                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 575                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 576                       crw0->erc, crw0->rsid);
 577         if (crw1)
 578                 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
 579                               "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 580                               crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
 581                               crw1->anc, crw1->erc, crw1->rsid);
 582         init_subchannel_id(&mchk_schid);
 583         mchk_schid.sch_no = crw0->rsid;
 584         if (crw1)
 585                 mchk_schid.ssid = (crw1->rsid >> 8) & 3;
 586
 587         /*
 588          * Since we are always presented with IPI in the CRW, we have to
 589          * use stsch() to find out if the subchannel in question has come
 590          * or gone.
 591          */
 592         css_evaluate_subchannel(mchk_schid, 0);
 593 }
 594
 595 static void __init
 596 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
 597 {
 598         if (css_general_characteristics.mcss) {
 599                 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
 600                 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
 601         } else {
 602 #ifdef CONFIG_SMP
 603                 css->global_pgid.pgid_high.cpu_addr = stap();
 604 #else
 605                 css->global_pgid.pgid_high.cpu_addr = 0;
 606 #endif
 607         }
 608         css->global_pgid.cpu_id = S390_lowcore.cpu_id.ident;
 609         css->global_pgid.cpu_model = S390_lowcore.cpu_id.machine;
 610         css->global_pgid.tod_high = tod_high;
 611
 612 }
 613
 614 static void
 615 channel_subsystem_release(struct device *dev)
 616 {
 617         struct channel_subsystem *css;
 618
 619         css = to_css(dev);
 620         mutex_destroy(&css->mutex);
 621         if (css->pseudo_subchannel) {
 622                 /* Implies that it has been generated but never registered. */
 623                 css_subchannel_release(&css->pseudo_subchannel->dev);
 624                 css->pseudo_subchannel = NULL;
 625         }
 626         kfree(css);
 627 }
 628
 629 static ssize_t
 630 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
 631                    char *buf)
 632 {
 633         struct channel_subsystem *css = to_css(dev);
 634         int ret;
 635
 636         if (!css)
 637                 return 0;
 638         mutex_lock(&css->mutex);
 639         ret = sprintf(buf, "%x\n", css->cm_enabled);
 640         mutex_unlock(&css->mutex);
 641         return ret;
 642 }
 643
 644 static ssize_t
 645 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
 646                     const char *buf, size_t count)
 647 {
 648         struct channel_subsystem *css = to_css(dev);
 649         int ret;
 650         unsigned long val;
 651
 652         ret = strict_strtoul(buf, 16, &val);
 653         if (ret)
 654                 return ret;
 655         mutex_lock(&css->mutex);
 656         switch (val) {
 657         case 0:
 658                 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
 659                 break;
 660         case 1:
 661                 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
 662                 break;
 663         default:
 664                 ret = -EINVAL;
 665         }
 666         mutex_unlock(&css->mutex);
 667         return ret < 0 ? ret : count;
 668 }
 669
 670 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
 671
 672 static int __init setup_css(int nr)
 673 {
 674         u32 tod_high;
 675         int ret;
 676         struct channel_subsystem *css;
 677
 678         css = channel_subsystems[nr];
 679         memset(css, 0, sizeof(struct channel_subsystem));
 680         css->pseudo_subchannel =
 681                 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
 682         if (!css->pseudo_subchannel)
 683                 return -ENOMEM;
 684         css->pseudo_subchannel->dev.parent = &css->device;
 685         css->pseudo_subchannel->dev.release = css_subchannel_release;
 686         dev_set_name(&css->pseudo_subchannel->dev, "defunct");
 687         ret = cio_create_sch_lock(css->pseudo_subchannel);
 688         if (ret) {
 689                 kfree(css->pseudo_subchannel);
 690                 return ret;
 691         }
 692         mutex_init(&css->mutex);
 693         css->valid = 1;
 694         css->cssid = nr;
 695         dev_set_name(&css->device, "css%x", nr);
 696         css->device.release = channel_subsystem_release;
 697         tod_high = (u32) (get_clock() >> 32);
 698         css_generate_pgid(css, tod_high);
 699         return 0;
 700 }
 701
 702 static int css_reboot_event(struct notifier_block *this,
 703                             unsigned long event,
 704                             void *ptr)
 705 {
 706         int ret, i;
 707
 708         ret = NOTIFY_DONE;
 709         for (i = 0; i <= __MAX_CSSID; i++) {
 710                 struct channel_subsystem *css;
 711
 712                 css = channel_subsystems[i];
 713                 mutex_lock(&css->mutex);
 714                 if (css->cm_enabled)
 715                         if (chsc_secm(css, 0))
 716                                 ret = NOTIFY_BAD;
 717                 mutex_unlock(&css->mutex);
 718         }
 719
 720         return ret;
 721 }
 722
 723 static struct notifier_block css_reboot_notifier = {
 724         .notifier_call = css_reboot_event,
 725 };
 726
 727 /*
 728  * Since the css devices are neither on a bus nor have a class
 729  * nor have a special device type, we cannot stop/restart channel
 730  * path measurements via the normal suspend/resume callbacks, but have
 731  * to use notifiers.
 732  */
 733 static int css_power_event(struct notifier_block *this, unsigned long event,
 734                            void *ptr)
 735 {
 736         void *secm_area;
 737         int ret, i;
 738
 739         switch (event) {
 740         case PM_HIBERNATION_PREPARE:
 741         case PM_SUSPEND_PREPARE:
 742                 ret = NOTIFY_DONE;
 743                 for (i = 0; i <= __MAX_CSSID; i++) {
 744                         struct channel_subsystem *css;
 745
 746                         css = channel_subsystems[i];
 747                         mutex_lock(&css->mutex);
 748                         if (!css->cm_enabled) {
 749                                 mutex_unlock(&css->mutex);
 750                                 continue;
 751                         }
 752                         secm_area = (void *)get_zeroed_page(GFP_KERNEL |
 753                                                             GFP_DMA);
 754                         if (secm_area) {
 755                                 if (__chsc_do_secm(css, 0, secm_area))
 756                                         ret = NOTIFY_BAD;
 757                                 free_page((unsigned long)secm_area);
 758                         } else
 759                                 ret = NOTIFY_BAD;
 760
 761                         mutex_unlock(&css->mutex);
 762                 }
 763                 break;
 764         case PM_POST_HIBERNATION:
 765         case PM_POST_SUSPEND:
 766                 ret = NOTIFY_DONE;
 767                 for (i = 0; i <= __MAX_CSSID; i++) {
 768                         struct channel_subsystem *css;
 769
 770                         css = channel_subsystems[i];
 771                         mutex_lock(&css->mutex);
 772                         if (!css->cm_enabled) {
 773                                 mutex_unlock(&css->mutex);
 774                                 continue;
 775                         }
 776                         secm_area = (void *)get_zeroed_page(GFP_KERNEL |
 777                                                             GFP_DMA);
 778                         if (secm_area) {
 779                                 if (__chsc_do_secm(css, 1, secm_area))
 780                                         ret = NOTIFY_BAD;
 781                                 free_page((unsigned long)secm_area);
 782                         } else
 783                                 ret = NOTIFY_BAD;
 784
 785                         mutex_unlock(&css->mutex);
 786                 }
 787                 /* search for subchannels, which appeared during hibernation */
 788                 css_schedule_reprobe();
 789                 break;
 790         default:
 791                 ret = NOTIFY_DONE;
 792         }
 793         return ret;
 794
 795 }
 796 static struct notifier_block css_power_notifier = {
 797         .notifier_call = css_power_event,
 798 };
 799
 800 /*
 801  * Now that the driver core is running, we can setup our channel subsystem.
 802  * The struct subchannel's are created during probing (except for the
 803  * static console subchannel).
 804  */
 805 static int __init css_bus_init(void)
 806 {
 807         int ret, i;
 808
 809         ret = chsc_determine_css_characteristics();
 810         if (ret == -ENOMEM)
 811                 goto out;
 812
 813         ret = chsc_alloc_sei_area();
 814         if (ret)
 815                 goto out;
 816
 817         /* Try to enable MSS. */
 818         ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
 819         switch (ret) {
 820         case 0: /* Success. */
 821                 max_ssid = __MAX_SSID;
 822                 break;
 823         case -ENOMEM:
 824                 goto out;
 825         default:
 826                 max_ssid = 0;
 827         }
 828
 829         ret = slow_subchannel_init();
 830         if (ret)
 831                 goto out;
 832
 833         ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
 834         if (ret)
 835                 goto out;
 836
 837         if ((ret = bus_register(&css_bus_type)))
 838                 goto out;
 839
 840         /* Setup css structure. */
 841         for (i = 0; i <= __MAX_CSSID; i++) {
 842                 struct channel_subsystem *css;
 843
 844                 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
 845                 if (!css) {
 846                         ret = -ENOMEM;
 847                         goto out_unregister;
 848                 }
 849                 channel_subsystems[i] = css;
 850                 ret = setup_css(i);
 851                 if (ret) {
 852                         kfree(channel_subsystems[i]);
 853                         goto out_unregister;
 854                 }
 855                 ret = device_register(&css->device);
 856                 if (ret) {
 857                         put_device(&css->device);
 858                         goto out_unregister;
 859                 }
 860                 if (css_chsc_characteristics.secm) {
 861                         ret = device_create_file(&css->device,
 862                                                  &dev_attr_cm_enable);
 863                         if (ret)
 864                                 goto out_device;
 865                 }
 866                 ret = device_register(&css->pseudo_subchannel->dev);
 867                 if (ret) {
 868                         put_device(&css->pseudo_subchannel->dev);
 869                         goto out_file;
 870                 }
 871         }
 872         ret = register_reboot_notifier(&css_reboot_notifier);
 873         if (ret)
 874                 goto out_unregister;
 875         ret = register_pm_notifier(&css_power_notifier);
 876         if (ret) {
 877                 unregister_reboot_notifier(&css_reboot_notifier);
 878                 goto out_unregister;
 879         }
 880         css_init_done = 1;
 881
 882         /* Enable default isc for I/O subchannels. */
 883         isc_register(IO_SCH_ISC);
 884
 885         return 0;
 886 out_file:
 887         if (css_chsc_characteristics.secm)
 888                 device_remove_file(&channel_subsystems[i]->device,
 889                                    &dev_attr_cm_enable);
 890 out_device:
 891         device_unregister(&channel_subsystems[i]->device);
 892 out_unregister:
 893         while (i > 0) {
 894                 struct channel_subsystem *css;
 895
 896                 i--;
 897                 css = channel_subsystems[i];
 898                 device_unregister(&css->pseudo_subchannel->dev);
 899                 css->pseudo_subchannel = NULL;
 900                 if (css_chsc_characteristics.secm)
 901                         device_remove_file(&css->device,
 902                                            &dev_attr_cm_enable);
 903                 device_unregister(&css->device);
 904         }
 905         bus_unregister(&css_bus_type);
 906 out:
 907         crw_unregister_handler(CRW_RSC_CSS);
 908         chsc_free_sei_area();
 909         idset_free(slow_subchannel_set);
 910         pr_alert("The CSS device driver initialization failed with "
 911                  "errno=%d\n", ret);
 912         return ret;
 913 }
 914
 915 static void __init css_bus_cleanup(void)
 916 {
 917         struct channel_subsystem *css;
 918         int i;
 919
 920         for (i = 0; i <= __MAX_CSSID; i++) {
 921                 css = channel_subsystems[i];
 922                 device_unregister(&css->pseudo_subchannel->dev);
 923                 css->pseudo_subchannel = NULL;
 924                 if (css_chsc_characteristics.secm)
 925                         device_remove_file(&css->device, &dev_attr_cm_enable);
 926                 device_unregister(&css->device);
 927         }
 928         bus_unregister(&css_bus_type);
 929         crw_unregister_handler(CRW_RSC_CSS);
 930         chsc_free_sei_area();
 931         idset_free(slow_subchannel_set);
 932         isc_unregister(IO_SCH_ISC);
 933 }
 934
 935 static int __init channel_subsystem_init(void)
 936 {
 937         int ret;
 938
 939         ret = css_bus_init();
 940         if (ret)
 941                 return ret;
 942
 943         ret = io_subchannel_init();
 944         if (ret)
 945                 css_bus_cleanup();
 946
 947         return ret;
 948 }
 949 subsys_initcall(channel_subsystem_init);
 950
 951 static int css_settle(struct device_driver *drv, void *unused)
 952 {
 953         struct css_driver *cssdrv = to_cssdriver(drv);
 954
 955         if (cssdrv->settle)
 956                 cssdrv->settle();
 957         return 0;
 958 }
 959
 960 /*
 961  * Wait for the initialization of devices to finish, to make sure we are
 962  * done with our setup if the search for the root device starts.
 963  */
 964 static int __init channel_subsystem_init_sync(void)
 965 {
 966         /* Start initial subchannel evaluation. */
 967         css_schedule_eval_all();
 968         /* Wait for the evaluation of subchannels to finish. */
 969         wait_event(css_eval_wq, atomic_read(&css_eval_scheduled) == 0);
 970         /* Wait for the subchannel type specific initialization to finish */
 971         return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
 972 }
 973 subsys_initcall_sync(channel_subsystem_init_sync);
 974
 975 int sch_is_pseudo_sch(struct subchannel *sch)
 976 {
 977         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
 978 }
 979
 980 static int css_bus_match(struct device *dev, struct device_driver *drv)
 981 {
 982         struct subchannel *sch = to_subchannel(dev);
 983         struct css_driver *driver = to_cssdriver(drv);
 984         struct css_device_id *id;
 985
 986         for (id = driver->subchannel_type; id->match_flags; id++) {
 987                 if (sch->st == id->type)
 988                         return 1;
 989         }
 990
 991         return 0;
 992 }
 993
 994 static int css_probe(struct device *dev)
 995 {
 996         struct subchannel *sch;
 997         int ret;
 998
 999         sch = to_subchannel(dev);
1000         sch->driver = to_cssdriver(dev->driver);
1001         ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1002         if (ret)
1003                 sch->driver = NULL;
1004         return ret;
1005 }
1006
1007 static int css_remove(struct device *dev)
1008 {
1009         struct subchannel *sch;
1010         int ret;
1011
1012         sch = to_subchannel(dev);
1013         ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1014         sch->driver = NULL;
1015         return ret;
1016 }
1017
1018 static void css_shutdown(struct device *dev)
1019 {
1020         struct subchannel *sch;
1021
1022         sch = to_subchannel(dev);
1023         if (sch->driver && sch->driver->shutdown)
1024                 sch->driver->shutdown(sch);
1025 }
1026
1027 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1028 {
1029         struct subchannel *sch = to_subchannel(dev);
1030         int ret;
1031
1032         ret = add_uevent_var(env, "ST=%01X", sch->st);
1033         if (ret)
1034                 return ret;
1035         ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1036         return ret;
1037 }
1038
1039 static int css_pm_prepare(struct device *dev)
1040 {
1041         struct subchannel *sch = to_subchannel(dev);
1042         struct css_driver *drv;
1043
1044         if (mutex_is_locked(&sch->reg_mutex))
1045                 return -EAGAIN;
1046         if (!sch->dev.driver)
1047                 return 0;
1048         drv = to_cssdriver(sch->dev.driver);
1049         /* Notify drivers that they may not register children. */
1050         return drv->prepare ? drv->prepare(sch) : 0;
1051 }
1052
1053 static void css_pm_complete(struct device *dev)
1054 {
1055         struct subchannel *sch = to_subchannel(dev);
1056         struct css_driver *drv;
1057
1058         if (!sch->dev.driver)
1059                 return;
1060         drv = to_cssdriver(sch->dev.driver);
1061         if (drv->complete)
1062                 drv->complete(sch);
1063 }
1064
1065 static int css_pm_freeze(struct device *dev)
1066 {
1067         struct subchannel *sch = to_subchannel(dev);
1068         struct css_driver *drv;
1069
1070         if (!sch->dev.driver)
1071                 return 0;
1072         drv = to_cssdriver(sch->dev.driver);
1073         return drv->freeze ? drv->freeze(sch) : 0;
1074 }
1075
1076 static int css_pm_thaw(struct device *dev)
1077 {
1078         struct subchannel *sch = to_subchannel(dev);
1079         struct css_driver *drv;
1080
1081         if (!sch->dev.driver)
1082                 return 0;
1083         drv = to_cssdriver(sch->dev.driver);
1084         return drv->thaw ? drv->thaw(sch) : 0;
1085 }
1086
1087 static int css_pm_restore(struct device *dev)
1088 {
1089         struct subchannel *sch = to_subchannel(dev);
1090         struct css_driver *drv;
1091
1092         if (!sch->dev.driver)
1093                 return 0;
1094         drv = to_cssdriver(sch->dev.driver);
1095         return drv->restore ? drv->restore(sch) : 0;
1096 }
1097
1098 static struct dev_pm_ops css_pm_ops = {
1099         .prepare = css_pm_prepare,
1100         .complete = css_pm_complete,
1101         .freeze = css_pm_freeze,
1102         .thaw = css_pm_thaw,
1103         .restore = css_pm_restore,
1104 };
1105
1106 struct bus_type css_bus_type = {
1107         .name     = "css",
1108         .match    = css_bus_match,
1109         .probe    = css_probe,
1110         .remove   = css_remove,
1111         .shutdown = css_shutdown,
1112         .uevent   = css_uevent,
1113         .pm = &css_pm_ops,
1114 };
1115
1116 /**
1117  * css_driver_register - register a css driver
1118  * @cdrv: css driver to register
1119  *
1120  * This is mainly a wrapper around driver_register that sets name
1121  * and bus_type in the embedded struct device_driver correctly.
1122  */
1123 int css_driver_register(struct css_driver *cdrv)
1124 {
1125         cdrv->drv.name = cdrv->name;
1126         cdrv->drv.bus = &css_bus_type;
1127         cdrv->drv.owner = cdrv->owner;
1128         return driver_register(&cdrv->drv);
1129 }
1130 EXPORT_SYMBOL_GPL(css_driver_register);
1131
1132 /**
1133  * css_driver_unregister - unregister a css driver
1134  * @cdrv: css driver to unregister
1135  *
1136  * This is a wrapper around driver_unregister.
1137  */
1138 void css_driver_unregister(struct css_driver *cdrv)
1139 {
1140         driver_unregister(&cdrv->drv);
1141 }
1142 EXPORT_SYMBOL_GPL(css_driver_unregister);
1143
1144 MODULE_LICENSE("GPL");
1145 EXPORT_SYMBOL(css_bus_type);