drivers/s390/cio/css.c

   1 /*
   2  * driver for channel subsystem
   3  *
   4  * Copyright IBM Corp. 2002, 2010
   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 <linux/proc_fs.h>
  22 #include <asm/isc.h>
  23 #include <asm/crw.h>
  24
  25 #include "css.h"
  26 #include "cio.h"
  27 #include "cio_debug.h"
  28 #include "ioasm.h"
  29 #include "chsc.h"
  30 #include "device.h"
  31 #include "idset.h"
  32 #include "chp.h"
  33
  34 int css_init_done = 0;
  35 int max_ssid;
  36
  37 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
  38 static struct bus_type css_bus_type;
  39
  40 int
  41 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
  42 {
  43         struct subchannel_id schid;
  44         int ret;
  45
  46         init_subchannel_id(&schid);
  47         ret = -ENODEV;
  48         do {
  49                 do {
  50                         ret = fn(schid, data);
  51                         if (ret)
  52                                 break;
  53                 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
  54                 schid.sch_no = 0;
  55         } while (schid.ssid++ < max_ssid);
  56         return ret;
  57 }
  58
  59 struct cb_data {
  60         void *data;
  61         struct idset *set;
  62         int (*fn_known_sch)(struct subchannel *, void *);
  63         int (*fn_unknown_sch)(struct subchannel_id, void *);
  64 };
  65
  66 static int call_fn_known_sch(struct device *dev, void *data)
  67 {
  68         struct subchannel *sch = to_subchannel(dev);
  69         struct cb_data *cb = data;
  70         int rc = 0;
  71
  72         idset_sch_del(cb->set, sch->schid);
  73         if (cb->fn_known_sch)
  74                 rc = cb->fn_known_sch(sch, cb->data);
  75         return rc;
  76 }
  77
  78 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
  79 {
  80         struct cb_data *cb = data;
  81         int rc = 0;
  82
  83         if (idset_sch_contains(cb->set, schid))
  84                 rc = cb->fn_unknown_sch(schid, cb->data);
  85         return rc;
  86 }
  87
  88 static int call_fn_all_sch(struct subchannel_id schid, void *data)
  89 {
  90         struct cb_data *cb = data;
  91         struct subchannel *sch;
  92         int rc = 0;
  93
  94         sch = get_subchannel_by_schid(schid);
  95         if (sch) {
  96                 if (cb->fn_known_sch)
  97                         rc = cb->fn_known_sch(sch, cb->data);
  98                 put_device(&sch->dev);
  99         } else {
 100                 if (cb->fn_unknown_sch)
 101                         rc = cb->fn_unknown_sch(schid, cb->data);
 102         }
 103
 104         return rc;
 105 }
 106
 107 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
 108                                int (*fn_unknown)(struct subchannel_id,
 109                                void *), void *data)
 110 {
 111         struct cb_data cb;
 112         int rc;
 113
 114         cb.data = data;
 115         cb.fn_known_sch = fn_known;
 116         cb.fn_unknown_sch = fn_unknown;
 117
 118         cb.set = idset_sch_new();
 119         if (!cb.set)
 120                 /* fall back to brute force scanning in case of oom */
 121                 return for_each_subchannel(call_fn_all_sch, &cb);
 122
 123         idset_fill(cb.set);
 124
 125         /* Process registered subchannels. */
 126         rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
 127         if (rc)
 128                 goto out;
 129         /* Process unregistered subchannels. */
 130         if (fn_unknown)
 131                 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
 132 out:
 133         idset_free(cb.set);
 134
 135         return rc;
 136 }
 137
 138 static void css_sch_todo(struct work_struct *work);
 139
 140 static struct subchannel *
 141 css_alloc_subchannel(struct subchannel_id schid)
 142 {
 143         struct subchannel *sch;
 144         int ret;
 145
 146         sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
 147         if (sch == NULL)
 148                 return ERR_PTR(-ENOMEM);
 149         ret = cio_validate_subchannel (sch, schid);
 150         if (ret < 0) {
 151                 kfree(sch);
 152                 return ERR_PTR(ret);
 153         }
 154         INIT_WORK(&sch->todo_work, css_sch_todo);
 155         return sch;
 156 }
 157
 158 static void
 159 css_subchannel_release(struct device *dev)
 160 {
 161         struct subchannel *sch;
 162
 163         sch = to_subchannel(dev);
 164         if (!cio_is_console(sch->schid)) {
 165                 /* Reset intparm to zeroes. */
 166                 sch->config.intparm = 0;
 167                 cio_commit_config(sch);
 168                 kfree(sch->lock);
 169                 kfree(sch);
 170         }
 171 }
 172
 173 static int css_sch_device_register(struct subchannel *sch)
 174 {
 175         int ret;
 176
 177         mutex_lock(&sch->reg_mutex);
 178         dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
 179                      sch->schid.sch_no);
 180         ret = device_register(&sch->dev);
 181         mutex_unlock(&sch->reg_mutex);
 182         return ret;
 183 }
 184
 185 /**
 186  * css_sch_device_unregister - unregister a subchannel
 187  * @sch: subchannel to be unregistered
 188  */
 189 void css_sch_device_unregister(struct subchannel *sch)
 190 {
 191         mutex_lock(&sch->reg_mutex);
 192         if (device_is_registered(&sch->dev))
 193                 device_unregister(&sch->dev);
 194         mutex_unlock(&sch->reg_mutex);
 195 }
 196 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
 197
 198 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
 199 {
 200         int i;
 201         int mask;
 202
 203         memset(ssd, 0, sizeof(struct chsc_ssd_info));
 204         ssd->path_mask = pmcw->pim;
 205         for (i = 0; i < 8; i++) {
 206                 mask = 0x80 >> i;
 207                 if (pmcw->pim & mask) {
 208                         chp_id_init(&ssd->chpid[i]);
 209                         ssd->chpid[i].id = pmcw->chpid[i];
 210                 }
 211         }
 212 }
 213
 214 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
 215 {
 216         int i;
 217         int mask;
 218
 219         for (i = 0; i < 8; i++) {
 220                 mask = 0x80 >> i;
 221                 if (ssd->path_mask & mask)
 222                         if (!chp_is_registered(ssd->chpid[i]))
 223                                 chp_new(ssd->chpid[i]);
 224         }
 225 }
 226
 227 void css_update_ssd_info(struct subchannel *sch)
 228 {
 229         int ret;
 230
 231         if (cio_is_console(sch->schid)) {
 232                 /* Console is initialized too early for functions requiring
 233                  * memory allocation. */
 234                 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
 235         } else {
 236                 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
 237                 if (ret)
 238                         ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
 239                 ssd_register_chpids(&sch->ssd_info);
 240         }
 241 }
 242
 243 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
 244                          char *buf)
 245 {
 246         struct subchannel *sch = to_subchannel(dev);
 247
 248         return sprintf(buf, "%01x\n", sch->st);
 249 }
 250
 251 static DEVICE_ATTR(type, 0444, type_show, NULL);
 252
 253 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 254                              char *buf)
 255 {
 256         struct subchannel *sch = to_subchannel(dev);
 257
 258         return sprintf(buf, "css:t%01X\n", sch->st);
 259 }
 260
 261 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 262
 263 static struct attribute *subch_attrs[] = {
 264         &dev_attr_type.attr,
 265         &dev_attr_modalias.attr,
 266         NULL,
 267 };
 268
 269 static struct attribute_group subch_attr_group = {
 270         .attrs = subch_attrs,
 271 };
 272
 273 static const struct attribute_group *default_subch_attr_groups[] = {
 274         &subch_attr_group,
 275         NULL,
 276 };
 277
 278 static int css_register_subchannel(struct subchannel *sch)
 279 {
 280         int ret;
 281
 282         /* Initialize the subchannel structure */
 283         sch->dev.parent = &channel_subsystems[0]->device;
 284         sch->dev.bus = &css_bus_type;
 285         sch->dev.release = &css_subchannel_release;
 286         sch->dev.groups = default_subch_attr_groups;
 287         /*
 288          * We don't want to generate uevents for I/O subchannels that don't
 289          * have a working ccw device behind them since they will be
 290          * unregistered before they can be used anyway, so we delay the add
 291          * uevent until after device recognition was successful.
 292          * Note that we suppress the uevent for all subchannel types;
 293          * the subchannel driver can decide itself when it wants to inform
 294          * userspace of its existence.
 295          */
 296         dev_set_uevent_suppress(&sch->dev, 1);
 297         css_update_ssd_info(sch);
 298         /* make it known to the system */
 299         ret = css_sch_device_register(sch);
 300         if (ret) {
 301                 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
 302                               sch->schid.ssid, sch->schid.sch_no, ret);
 303                 return ret;
 304         }
 305         if (!sch->driver) {
 306                 /*
 307                  * No driver matched. Generate the uevent now so that
 308                  * a fitting driver module may be loaded based on the
 309                  * modalias.
 310                  */
 311                 dev_set_uevent_suppress(&sch->dev, 0);
 312                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 313         }
 314         return ret;
 315 }
 316
 317 int css_probe_device(struct subchannel_id schid)
 318 {
 319         int ret;
 320         struct subchannel *sch;
 321
 322         if (cio_is_console(schid))
 323                 sch = cio_get_console_subchannel();
 324         else {
 325                 sch = css_alloc_subchannel(schid);
 326                 if (IS_ERR(sch))
 327                         return PTR_ERR(sch);
 328         }
 329         ret = css_register_subchannel(sch);
 330         if (ret) {
 331                 if (!cio_is_console(schid))
 332                         put_device(&sch->dev);
 333         }
 334         return ret;
 335 }
 336
 337 static int
 338 check_subchannel(struct device * dev, void * data)
 339 {
 340         struct subchannel *sch;
 341         struct subchannel_id *schid = data;
 342
 343         sch = to_subchannel(dev);
 344         return schid_equal(&sch->schid, schid);
 345 }
 346
 347 struct subchannel *
 348 get_subchannel_by_schid(struct subchannel_id schid)
 349 {
 350         struct device *dev;
 351
 352         dev = bus_find_device(&css_bus_type, NULL,
 353                               &schid, check_subchannel);
 354
 355         return dev ? to_subchannel(dev) : NULL;
 356 }
 357
 358 /**
 359  * css_sch_is_valid() - check if a subchannel is valid
 360  * @schib: subchannel information block for the subchannel
 361  */
 362 int css_sch_is_valid(struct schib *schib)
 363 {
 364         if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
 365                 return 0;
 366         if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
 367                 return 0;
 368         return 1;
 369 }
 370 EXPORT_SYMBOL_GPL(css_sch_is_valid);
 371
 372 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
 373 {
 374         struct schib schib;
 375
 376         if (!slow) {
 377                 /* Will be done on the slow path. */
 378                 return -EAGAIN;
 379         }
 380         if (stsch_err(schid, &schib)) {
 381                 /* Subchannel is not provided. */
 382                 return -ENXIO;
 383         }
 384         if (!css_sch_is_valid(&schib)) {
 385                 /* Unusable - ignore. */
 386                 return 0;
 387         }
 388         CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
 389                       schid.sch_no);
 390
 391         return css_probe_device(schid);
 392 }
 393
 394 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
 395 {
 396         int ret = 0;
 397
 398         if (sch->driver) {
 399                 if (sch->driver->sch_event)
 400                         ret = sch->driver->sch_event(sch, slow);
 401                 else
 402                         dev_dbg(&sch->dev,
 403                                 "Got subchannel machine check but "
 404                                 "no sch_event handler provided.\n");
 405         }
 406         if (ret != 0 && ret != -EAGAIN) {
 407                 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
 408                               sch->schid.ssid, sch->schid.sch_no, ret);
 409         }
 410         return ret;
 411 }
 412
 413 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
 414 {
 415         struct subchannel *sch;
 416         int ret;
 417
 418         sch = get_subchannel_by_schid(schid);
 419         if (sch) {
 420                 ret = css_evaluate_known_subchannel(sch, slow);
 421                 put_device(&sch->dev);
 422         } else
 423                 ret = css_evaluate_new_subchannel(schid, slow);
 424         if (ret == -EAGAIN)
 425                 css_schedule_eval(schid);
 426 }
 427
 428 /**
 429  * css_sched_sch_todo - schedule a subchannel operation
 430  * @sch: subchannel
 431  * @todo: todo
 432  *
 433  * Schedule the operation identified by @todo to be performed on the slow path
 434  * workqueue. Do nothing if another operation with higher priority is already
 435  * scheduled. Needs to be called with subchannel lock held.
 436  */
 437 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
 438 {
 439         CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
 440                       sch->schid.ssid, sch->schid.sch_no, todo);
 441         if (sch->todo >= todo)
 442                 return;
 443         /* Get workqueue ref. */
 444         if (!get_device(&sch->dev))
 445                 return;
 446         sch->todo = todo;
 447         if (!queue_work(cio_work_q, &sch->todo_work)) {
 448                 /* Already queued, release workqueue ref. */
 449                 put_device(&sch->dev);
 450         }
 451 }
 452 EXPORT_SYMBOL_GPL(css_sched_sch_todo);
 453
 454 static void css_sch_todo(struct work_struct *work)
 455 {
 456         struct subchannel *sch;
 457         enum sch_todo todo;
 458         int ret;
 459
 460         sch = container_of(work, struct subchannel, todo_work);
 461         /* Find out todo. */
 462         spin_lock_irq(sch->lock);
 463         todo = sch->todo;
 464         CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
 465                       sch->schid.sch_no, todo);
 466         sch->todo = SCH_TODO_NOTHING;
 467         spin_unlock_irq(sch->lock);
 468         /* Perform todo. */
 469         switch (todo) {
 470         case SCH_TODO_NOTHING:
 471                 break;
 472         case SCH_TODO_EVAL:
 473                 ret = css_evaluate_known_subchannel(sch, 1);
 474                 if (ret == -EAGAIN) {
 475                         spin_lock_irq(sch->lock);
 476                         css_sched_sch_todo(sch, todo);
 477                         spin_unlock_irq(sch->lock);
 478                 }
 479                 break;
 480         case SCH_TODO_UNREG:
 481                 css_sch_device_unregister(sch);
 482                 break;
 483         }
 484         /* Release workqueue ref. */
 485         put_device(&sch->dev);
 486 }
 487
 488 static struct idset *slow_subchannel_set;
 489 static spinlock_t slow_subchannel_lock;
 490 static wait_queue_head_t css_eval_wq;
 491 static atomic_t css_eval_scheduled;
 492
 493 static int __init slow_subchannel_init(void)
 494 {
 495         spin_lock_init(&slow_subchannel_lock);
 496         atomic_set(&css_eval_scheduled, 0);
 497         init_waitqueue_head(&css_eval_wq);
 498         slow_subchannel_set = idset_sch_new();
 499         if (!slow_subchannel_set) {
 500                 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
 501                 return -ENOMEM;
 502         }
 503         return 0;
 504 }
 505
 506 static int slow_eval_known_fn(struct subchannel *sch, void *data)
 507 {
 508         int eval;
 509         int rc;
 510
 511         spin_lock_irq(&slow_subchannel_lock);
 512         eval = idset_sch_contains(slow_subchannel_set, sch->schid);
 513         idset_sch_del(slow_subchannel_set, sch->schid);
 514         spin_unlock_irq(&slow_subchannel_lock);
 515         if (eval) {
 516                 rc = css_evaluate_known_subchannel(sch, 1);
 517                 if (rc == -EAGAIN)
 518                         css_schedule_eval(sch->schid);
 519         }
 520         return 0;
 521 }
 522
 523 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
 524 {
 525         int eval;
 526         int rc = 0;
 527
 528         spin_lock_irq(&slow_subchannel_lock);
 529         eval = idset_sch_contains(slow_subchannel_set, schid);
 530         idset_sch_del(slow_subchannel_set, schid);
 531         spin_unlock_irq(&slow_subchannel_lock);
 532         if (eval) {
 533                 rc = css_evaluate_new_subchannel(schid, 1);
 534                 switch (rc) {
 535                 case -EAGAIN:
 536                         css_schedule_eval(schid);
 537                         rc = 0;
 538                         break;
 539                 case -ENXIO:
 540                 case -ENOMEM:
 541                 case -EIO:
 542                         /* These should abort looping */
 543                         idset_sch_del_subseq(slow_subchannel_set, schid);
 544                         break;
 545                 default:
 546                         rc = 0;
 547                 }
 548         }
 549         return rc;
 550 }
 551
 552 static void css_slow_path_func(struct work_struct *unused)
 553 {
 554         unsigned long flags;
 555
 556         CIO_TRACE_EVENT(4, "slowpath");
 557         for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
 558                                    NULL);
 559         spin_lock_irqsave(&slow_subchannel_lock, flags);
 560         if (idset_is_empty(slow_subchannel_set)) {
 561                 atomic_set(&css_eval_scheduled, 0);
 562                 wake_up(&css_eval_wq);
 563         }
 564         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 565 }
 566
 567 static DECLARE_WORK(slow_path_work, css_slow_path_func);
 568 struct workqueue_struct *cio_work_q;
 569
 570 void css_schedule_eval(struct subchannel_id schid)
 571 {
 572         unsigned long flags;
 573
 574         spin_lock_irqsave(&slow_subchannel_lock, flags);
 575         idset_sch_add(slow_subchannel_set, schid);
 576         atomic_set(&css_eval_scheduled, 1);
 577         queue_work(cio_work_q, &slow_path_work);
 578         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 579 }
 580
 581 void css_schedule_eval_all(void)
 582 {
 583         unsigned long flags;
 584
 585         spin_lock_irqsave(&slow_subchannel_lock, flags);
 586         idset_fill(slow_subchannel_set);
 587         atomic_set(&css_eval_scheduled, 1);
 588         queue_work(cio_work_q, &slow_path_work);
 589         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 590 }
 591
 592 static int __unset_registered(struct device *dev, void *data)
 593 {
 594         struct idset *set = data;
 595         struct subchannel *sch = to_subchannel(dev);
 596
 597         idset_sch_del(set, sch->schid);
 598         return 0;
 599 }
 600
 601 static void css_schedule_eval_all_unreg(void)
 602 {
 603         unsigned long flags;
 604         struct idset *unreg_set;
 605
 606         /* Find unregistered subchannels. */
 607         unreg_set = idset_sch_new();
 608         if (!unreg_set) {
 609                 /* Fallback. */
 610                 css_schedule_eval_all();
 611                 return;
 612         }
 613         idset_fill(unreg_set);
 614         bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
 615         /* Apply to slow_subchannel_set. */
 616         spin_lock_irqsave(&slow_subchannel_lock, flags);
 617         idset_add_set(slow_subchannel_set, unreg_set);
 618         atomic_set(&css_eval_scheduled, 1);
 619         queue_work(cio_work_q, &slow_path_work);
 620         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 621         idset_free(unreg_set);
 622 }
 623
 624 void css_wait_for_slow_path(void)
 625 {
 626         flush_workqueue(cio_work_q);
 627 }
 628
 629 /* Schedule reprobing of all unregistered subchannels. */
 630 void css_schedule_reprobe(void)
 631 {
 632         css_schedule_eval_all_unreg();
 633 }
 634 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 635
 636 /*
 637  * Called from the machine check handler for subchannel report words.
 638  */
 639 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 640 {
 641         struct subchannel_id mchk_schid;
 642         struct subchannel *sch;
 643
 644         if (overflow) {
 645                 css_schedule_eval_all();
 646                 return;
 647         }
 648         CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
 649                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 650                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 651                       crw0->erc, crw0->rsid);
 652         if (crw1)
 653                 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
 654                               "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 655                               crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
 656                               crw1->anc, crw1->erc, crw1->rsid);
 657         init_subchannel_id(&mchk_schid);
 658         mchk_schid.sch_no = crw0->rsid;
 659         if (crw1)
 660                 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
 661
 662         if (crw0->erc == CRW_ERC_PMOD) {
 663                 sch = get_subchannel_by_schid(mchk_schid);
 664                 if (sch) {
 665                         css_update_ssd_info(sch);
 666                         put_device(&sch->dev);
 667                 }
 668         }
 669         /*
 670          * Since we are always presented with IPI in the CRW, we have to
 671          * use stsch() to find out if the subchannel in question has come
 672          * or gone.
 673          */
 674         css_evaluate_subchannel(mchk_schid, 0);
 675 }
 676
 677 static void __init
 678 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
 679 {
 680         struct cpuid cpu_id;
 681
 682         if (css_general_characteristics.mcss) {
 683                 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
 684                 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
 685         } else {
 686 #ifdef CONFIG_SMP
 687                 css->global_pgid.pgid_high.cpu_addr = stap();
 688 #else
 689                 css->global_pgid.pgid_high.cpu_addr = 0;
 690 #endif
 691         }
 692         get_cpu_id(&cpu_id);
 693         css->global_pgid.cpu_id = cpu_id.ident;
 694         css->global_pgid.cpu_model = cpu_id.machine;
 695         css->global_pgid.tod_high = tod_high;
 696
 697 }
 698
 699 static void
 700 channel_subsystem_release(struct device *dev)
 701 {
 702         struct channel_subsystem *css;
 703
 704         css = to_css(dev);
 705         mutex_destroy(&css->mutex);
 706         if (css->pseudo_subchannel) {
 707                 /* Implies that it has been generated but never registered. */
 708                 css_subchannel_release(&css->pseudo_subchannel->dev);
 709                 css->pseudo_subchannel = NULL;
 710         }
 711         kfree(css);
 712 }
 713
 714 static ssize_t
 715 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
 716                    char *buf)
 717 {
 718         struct channel_subsystem *css = to_css(dev);
 719         int ret;
 720
 721         if (!css)
 722                 return 0;
 723         mutex_lock(&css->mutex);
 724         ret = sprintf(buf, "%x\n", css->cm_enabled);
 725         mutex_unlock(&css->mutex);
 726         return ret;
 727 }
 728
 729 static ssize_t
 730 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
 731                     const char *buf, size_t count)
 732 {
 733         struct channel_subsystem *css = to_css(dev);
 734         int ret;
 735         unsigned long val;
 736
 737         ret = strict_strtoul(buf, 16, &val);
 738         if (ret)
 739                 return ret;
 740         mutex_lock(&css->mutex);
 741         switch (val) {
 742         case 0:
 743                 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
 744                 break;
 745         case 1:
 746                 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
 747                 break;
 748         default:
 749                 ret = -EINVAL;
 750         }
 751         mutex_unlock(&css->mutex);
 752         return ret < 0 ? ret : count;
 753 }
 754
 755 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
 756
 757 static int __init setup_css(int nr)
 758 {
 759         u32 tod_high;
 760         int ret;
 761         struct channel_subsystem *css;
 762
 763         css = channel_subsystems[nr];
 764         memset(css, 0, sizeof(struct channel_subsystem));
 765         css->pseudo_subchannel =
 766                 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
 767         if (!css->pseudo_subchannel)
 768                 return -ENOMEM;
 769         css->pseudo_subchannel->dev.parent = &css->device;
 770         css->pseudo_subchannel->dev.release = css_subchannel_release;
 771         dev_set_name(&css->pseudo_subchannel->dev, "defunct");
 772         mutex_init(&css->pseudo_subchannel->reg_mutex);
 773         ret = cio_create_sch_lock(css->pseudo_subchannel);
 774         if (ret) {
 775                 kfree(css->pseudo_subchannel);
 776                 return ret;
 777         }
 778         mutex_init(&css->mutex);
 779         css->valid = 1;
 780         css->cssid = nr;
 781         dev_set_name(&css->device, "css%x", nr);
 782         css->device.release = channel_subsystem_release;
 783         tod_high = (u32) (get_tod_clock() >> 32);
 784         css_generate_pgid(css, tod_high);
 785         return 0;
 786 }
 787
 788 static int css_reboot_event(struct notifier_block *this,
 789                             unsigned long event,
 790                             void *ptr)
 791 {
 792         int ret, i;
 793
 794         ret = NOTIFY_DONE;
 795         for (i = 0; i <= __MAX_CSSID; i++) {
 796                 struct channel_subsystem *css;
 797
 798                 css = channel_subsystems[i];
 799                 mutex_lock(&css->mutex);
 800                 if (css->cm_enabled)
 801                         if (chsc_secm(css, 0))
 802                                 ret = NOTIFY_BAD;
 803                 mutex_unlock(&css->mutex);
 804         }
 805
 806         return ret;
 807 }
 808
 809 static struct notifier_block css_reboot_notifier = {
 810         .notifier_call = css_reboot_event,
 811 };
 812
 813 /*
 814  * Since the css devices are neither on a bus nor have a class
 815  * nor have a special device type, we cannot stop/restart channel
 816  * path measurements via the normal suspend/resume callbacks, but have
 817  * to use notifiers.
 818  */
 819 static int css_power_event(struct notifier_block *this, unsigned long event,
 820                            void *ptr)
 821 {
 822         int ret, i;
 823
 824         switch (event) {
 825         case PM_HIBERNATION_PREPARE:
 826         case PM_SUSPEND_PREPARE:
 827                 ret = NOTIFY_DONE;
 828                 for (i = 0; i <= __MAX_CSSID; i++) {
 829                         struct channel_subsystem *css;
 830
 831                         css = channel_subsystems[i];
 832                         mutex_lock(&css->mutex);
 833                         if (!css->cm_enabled) {
 834                                 mutex_unlock(&css->mutex);
 835                                 continue;
 836                         }
 837                         ret = __chsc_do_secm(css, 0);
 838                         ret = notifier_from_errno(ret);
 839                         mutex_unlock(&css->mutex);
 840                 }
 841                 break;
 842         case PM_POST_HIBERNATION:
 843         case PM_POST_SUSPEND:
 844                 ret = NOTIFY_DONE;
 845                 for (i = 0; i <= __MAX_CSSID; i++) {
 846                         struct channel_subsystem *css;
 847
 848                         css = channel_subsystems[i];
 849                         mutex_lock(&css->mutex);
 850                         if (!css->cm_enabled) {
 851                                 mutex_unlock(&css->mutex);
 852                                 continue;
 853                         }
 854                         ret = __chsc_do_secm(css, 1);
 855                         ret = notifier_from_errno(ret);
 856                         mutex_unlock(&css->mutex);
 857                 }
 858                 /* search for subchannels, which appeared during hibernation */
 859                 css_schedule_reprobe();
 860                 break;
 861         default:
 862                 ret = NOTIFY_DONE;
 863         }
 864         return ret;
 865
 866 }
 867 static struct notifier_block css_power_notifier = {
 868         .notifier_call = css_power_event,
 869 };
 870
 871 /*
 872  * Now that the driver core is running, we can setup our channel subsystem.
 873  * The struct subchannel's are created during probing (except for the
 874  * static console subchannel).
 875  */
 876 static int __init css_bus_init(void)
 877 {
 878         int ret, i;
 879
 880         ret = chsc_init();
 881         if (ret)
 882                 return ret;
 883
 884         chsc_determine_css_characteristics();
 885         /* Try to enable MSS. */
 886         ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
 887         if (ret)
 888                 max_ssid = 0;
 889         else /* Success. */
 890                 max_ssid = __MAX_SSID;
 891
 892         ret = slow_subchannel_init();
 893         if (ret)
 894                 goto out;
 895
 896         ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
 897         if (ret)
 898                 goto out;
 899
 900         if ((ret = bus_register(&css_bus_type)))
 901                 goto out;
 902
 903         /* Setup css structure. */
 904         for (i = 0; i <= __MAX_CSSID; i++) {
 905                 struct channel_subsystem *css;
 906
 907                 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
 908                 if (!css) {
 909                         ret = -ENOMEM;
 910                         goto out_unregister;
 911                 }
 912                 channel_subsystems[i] = css;
 913                 ret = setup_css(i);
 914                 if (ret) {
 915                         kfree(channel_subsystems[i]);
 916                         goto out_unregister;
 917                 }
 918                 ret = device_register(&css->device);
 919                 if (ret) {
 920                         put_device(&css->device);
 921                         goto out_unregister;
 922                 }
 923                 if (css_chsc_characteristics.secm) {
 924                         ret = device_create_file(&css->device,
 925                                                  &dev_attr_cm_enable);
 926                         if (ret)
 927                                 goto out_device;
 928                 }
 929                 ret = device_register(&css->pseudo_subchannel->dev);
 930                 if (ret) {
 931                         put_device(&css->pseudo_subchannel->dev);
 932                         goto out_file;
 933                 }
 934         }
 935         ret = register_reboot_notifier(&css_reboot_notifier);
 936         if (ret)
 937                 goto out_unregister;
 938         ret = register_pm_notifier(&css_power_notifier);
 939         if (ret) {
 940                 unregister_reboot_notifier(&css_reboot_notifier);
 941                 goto out_unregister;
 942         }
 943         css_init_done = 1;
 944
 945         /* Enable default isc for I/O subchannels. */
 946         isc_register(IO_SCH_ISC);
 947
 948         return 0;
 949 out_file:
 950         if (css_chsc_characteristics.secm)
 951                 device_remove_file(&channel_subsystems[i]->device,
 952                                    &dev_attr_cm_enable);
 953 out_device:
 954         device_unregister(&channel_subsystems[i]->device);
 955 out_unregister:
 956         while (i > 0) {
 957                 struct channel_subsystem *css;
 958
 959                 i--;
 960                 css = channel_subsystems[i];
 961                 device_unregister(&css->pseudo_subchannel->dev);
 962                 css->pseudo_subchannel = NULL;
 963                 if (css_chsc_characteristics.secm)
 964                         device_remove_file(&css->device,
 965                                            &dev_attr_cm_enable);
 966                 device_unregister(&css->device);
 967         }
 968         bus_unregister(&css_bus_type);
 969 out:
 970         crw_unregister_handler(CRW_RSC_SCH);
 971         idset_free(slow_subchannel_set);
 972         chsc_init_cleanup();
 973         pr_alert("The CSS device driver initialization failed with "
 974                  "errno=%d\n", ret);
 975         return ret;
 976 }
 977
 978 static void __init css_bus_cleanup(void)
 979 {
 980         struct channel_subsystem *css;
 981         int i;
 982
 983         for (i = 0; i <= __MAX_CSSID; i++) {
 984                 css = channel_subsystems[i];
 985                 device_unregister(&css->pseudo_subchannel->dev);
 986                 css->pseudo_subchannel = NULL;
 987                 if (css_chsc_characteristics.secm)
 988                         device_remove_file(&css->device, &dev_attr_cm_enable);
 989                 device_unregister(&css->device);
 990         }
 991         bus_unregister(&css_bus_type);
 992         crw_unregister_handler(CRW_RSC_SCH);
 993         idset_free(slow_subchannel_set);
 994         chsc_init_cleanup();
 995         isc_unregister(IO_SCH_ISC);
 996 }
 997
 998 static int __init channel_subsystem_init(void)
 999 {
1000         int ret;
1001
1002         ret = css_bus_init();
1003         if (ret)
1004                 return ret;
1005         cio_work_q = create_singlethread_workqueue("cio");
1006         if (!cio_work_q) {
1007                 ret = -ENOMEM;
1008                 goto out_bus;
1009         }
1010         ret = io_subchannel_init();
1011         if (ret)
1012                 goto out_wq;
1013
1014         return ret;
1015 out_wq:
1016         destroy_workqueue(cio_work_q);
1017 out_bus:
1018         css_bus_cleanup();
1019         return ret;
1020 }
1021 subsys_initcall(channel_subsystem_init);
1022
1023 static int css_settle(struct device_driver *drv, void *unused)
1024 {
1025         struct css_driver *cssdrv = to_cssdriver(drv);
1026
1027         if (cssdrv->settle)
1028                 return cssdrv->settle();
1029         return 0;
1030 }
1031
1032 int css_complete_work(void)
1033 {
1034         int ret;
1035
1036         /* Wait for the evaluation of subchannels to finish. */
1037         ret = wait_event_interruptible(css_eval_wq,
1038                                        atomic_read(&css_eval_scheduled) == 0);
1039         if (ret)
1040                 return -EINTR;
1041         flush_workqueue(cio_work_q);
1042         /* Wait for the subchannel type specific initialization to finish */
1043         return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1044 }
1045
1046
1047 /*
1048  * Wait for the initialization of devices to finish, to make sure we are
1049  * done with our setup if the search for the root device starts.
1050  */
1051 static int __init channel_subsystem_init_sync(void)
1052 {
1053         /* Start initial subchannel evaluation. */
1054         css_schedule_eval_all();
1055         css_complete_work();
1056         return 0;
1057 }
1058 subsys_initcall_sync(channel_subsystem_init_sync);
1059
1060 void channel_subsystem_reinit(void)
1061 {
1062         struct channel_path *chp;
1063         struct chp_id chpid;
1064
1065         chsc_enable_facility(CHSC_SDA_OC_MSS);
1066         chp_id_for_each(&chpid) {
1067                 chp = chpid_to_chp(chpid);
1068                 if (!chp)
1069                         continue;
1070                 chsc_determine_base_channel_path_desc(chpid, &chp->desc);
1071         }
1072 }
1073
1074 #ifdef CONFIG_PROC_FS
1075 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1076                                 size_t count, loff_t *ppos)
1077 {
1078         int ret;
1079
1080         /* Handle pending CRW's. */
1081         crw_wait_for_channel_report();
1082         ret = css_complete_work();
1083
1084         return ret ? ret : count;
1085 }
1086
1087 static const struct file_operations cio_settle_proc_fops = {
1088         .open = nonseekable_open,
1089         .write = cio_settle_write,
1090         .llseek = no_llseek,
1091 };
1092
1093 static int __init cio_settle_init(void)
1094 {
1095         struct proc_dir_entry *entry;
1096
1097         entry = proc_create("cio_settle", S_IWUSR, NULL,
1098                             &cio_settle_proc_fops);
1099         if (!entry)
1100                 return -ENOMEM;
1101         return 0;
1102 }
1103 device_initcall(cio_settle_init);
1104 #endif /*CONFIG_PROC_FS*/
1105
1106 int sch_is_pseudo_sch(struct subchannel *sch)
1107 {
1108         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1109 }
1110
1111 static int css_bus_match(struct device *dev, struct device_driver *drv)
1112 {
1113         struct subchannel *sch = to_subchannel(dev);
1114         struct css_driver *driver = to_cssdriver(drv);
1115         struct css_device_id *id;
1116
1117         for (id = driver->subchannel_type; id->match_flags; id++) {
1118                 if (sch->st == id->type)
1119                         return 1;
1120         }
1121
1122         return 0;
1123 }
1124
1125 static int css_probe(struct device *dev)
1126 {
1127         struct subchannel *sch;
1128         int ret;
1129
1130         sch = to_subchannel(dev);
1131         sch->driver = to_cssdriver(dev->driver);
1132         ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1133         if (ret)
1134                 sch->driver = NULL;
1135         return ret;
1136 }
1137
1138 static int css_remove(struct device *dev)
1139 {
1140         struct subchannel *sch;
1141         int ret;
1142
1143         sch = to_subchannel(dev);
1144         ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1145         sch->driver = NULL;
1146         return ret;
1147 }
1148
1149 static void css_shutdown(struct device *dev)
1150 {
1151         struct subchannel *sch;
1152
1153         sch = to_subchannel(dev);
1154         if (sch->driver && sch->driver->shutdown)
1155                 sch->driver->shutdown(sch);
1156 }
1157
1158 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1159 {
1160         struct subchannel *sch = to_subchannel(dev);
1161         int ret;
1162
1163         ret = add_uevent_var(env, "ST=%01X", sch->st);
1164         if (ret)
1165                 return ret;
1166         ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1167         return ret;
1168 }
1169
1170 static int css_pm_prepare(struct device *dev)
1171 {
1172         struct subchannel *sch = to_subchannel(dev);
1173         struct css_driver *drv;
1174
1175         if (mutex_is_locked(&sch->reg_mutex))
1176                 return -EAGAIN;
1177         if (!sch->dev.driver)
1178                 return 0;
1179         drv = to_cssdriver(sch->dev.driver);
1180         /* Notify drivers that they may not register children. */
1181         return drv->prepare ? drv->prepare(sch) : 0;
1182 }
1183
1184 static void css_pm_complete(struct device *dev)
1185 {
1186         struct subchannel *sch = to_subchannel(dev);
1187         struct css_driver *drv;
1188
1189         if (!sch->dev.driver)
1190                 return;
1191         drv = to_cssdriver(sch->dev.driver);
1192         if (drv->complete)
1193                 drv->complete(sch);
1194 }
1195
1196 static int css_pm_freeze(struct device *dev)
1197 {
1198         struct subchannel *sch = to_subchannel(dev);
1199         struct css_driver *drv;
1200
1201         if (!sch->dev.driver)
1202                 return 0;
1203         drv = to_cssdriver(sch->dev.driver);
1204         return drv->freeze ? drv->freeze(sch) : 0;
1205 }
1206
1207 static int css_pm_thaw(struct device *dev)
1208 {
1209         struct subchannel *sch = to_subchannel(dev);
1210         struct css_driver *drv;
1211
1212         if (!sch->dev.driver)
1213                 return 0;
1214         drv = to_cssdriver(sch->dev.driver);
1215         return drv->thaw ? drv->thaw(sch) : 0;
1216 }
1217
1218 static int css_pm_restore(struct device *dev)
1219 {
1220         struct subchannel *sch = to_subchannel(dev);
1221         struct css_driver *drv;
1222
1223         css_update_ssd_info(sch);
1224         if (!sch->dev.driver)
1225                 return 0;
1226         drv = to_cssdriver(sch->dev.driver);
1227         return drv->restore ? drv->restore(sch) : 0;
1228 }
1229
1230 static const struct dev_pm_ops css_pm_ops = {
1231         .prepare = css_pm_prepare,
1232         .complete = css_pm_complete,
1233         .freeze = css_pm_freeze,
1234         .thaw = css_pm_thaw,
1235         .restore = css_pm_restore,
1236 };
1237
1238 static struct bus_type css_bus_type = {
1239         .name     = "css",
1240         .match    = css_bus_match,
1241         .probe    = css_probe,
1242         .remove   = css_remove,
1243         .shutdown = css_shutdown,
1244         .uevent   = css_uevent,
1245         .pm = &css_pm_ops,
1246 };
1247
1248 /**
1249  * css_driver_register - register a css driver
1250  * @cdrv: css driver to register
1251  *
1252  * This is mainly a wrapper around driver_register that sets name
1253  * and bus_type in the embedded struct device_driver correctly.
1254  */
1255 int css_driver_register(struct css_driver *cdrv)
1256 {
1257         cdrv->drv.bus = &css_bus_type;
1258         return driver_register(&cdrv->drv);
1259 }
1260 EXPORT_SYMBOL_GPL(css_driver_register);
1261
1262 /**
1263  * css_driver_unregister - unregister a css driver
1264  * @cdrv: css driver to unregister
1265  *
1266  * This is a wrapper around driver_unregister.
1267  */
1268 void css_driver_unregister(struct css_driver *cdrv)
1269 {
1270         driver_unregister(&cdrv->drv);
1271 }
1272 EXPORT_SYMBOL_GPL(css_driver_unregister);
1273
1274 MODULE_LICENSE("GPL");