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 int css_sch_create_locks(struct subchannel *sch)
 141 {
 142         sch->lock = kmalloc(sizeof(*sch->lock), GFP_KERNEL);
 143         if (!sch->lock)
 144                 return -ENOMEM;
 145
 146         spin_lock_init(sch->lock);
 147         mutex_init(&sch->reg_mutex);
 148
 149         return 0;
 150 }
 151
 152 static void css_subchannel_release(struct device *dev)
 153 {
 154         struct subchannel *sch = to_subchannel(dev);
 155
 156         sch->config.intparm = 0;
 157         cio_commit_config(sch);
 158         kfree(sch->lock);
 159         kfree(sch);
 160 }
 161
 162 struct subchannel *css_alloc_subchannel(struct subchannel_id schid)
 163 {
 164         struct subchannel *sch;
 165         int ret;
 166
 167         sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA);
 168         if (!sch)
 169                 return ERR_PTR(-ENOMEM);
 170
 171         ret = cio_validate_subchannel(sch, schid);
 172         if (ret < 0)
 173                 goto err;
 174
 175         ret = css_sch_create_locks(sch);
 176         if (ret)
 177                 goto err;
 178
 179         INIT_WORK(&sch->todo_work, css_sch_todo);
 180         sch->dev.release = &css_subchannel_release;
 181         device_initialize(&sch->dev);
 182         return sch;
 183
 184 err:
 185         kfree(sch);
 186         return ERR_PTR(ret);
 187 }
 188
 189 static int css_sch_device_register(struct subchannel *sch)
 190 {
 191         int ret;
 192
 193         mutex_lock(&sch->reg_mutex);
 194         dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
 195                      sch->schid.sch_no);
 196         ret = device_add(&sch->dev);
 197         mutex_unlock(&sch->reg_mutex);
 198         return ret;
 199 }
 200
 201 /**
 202  * css_sch_device_unregister - unregister a subchannel
 203  * @sch: subchannel to be unregistered
 204  */
 205 void css_sch_device_unregister(struct subchannel *sch)
 206 {
 207         mutex_lock(&sch->reg_mutex);
 208         if (device_is_registered(&sch->dev))
 209                 device_unregister(&sch->dev);
 210         mutex_unlock(&sch->reg_mutex);
 211 }
 212 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
 213
 214 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
 215 {
 216         int i;
 217         int mask;
 218
 219         memset(ssd, 0, sizeof(struct chsc_ssd_info));
 220         ssd->path_mask = pmcw->pim;
 221         for (i = 0; i < 8; i++) {
 222                 mask = 0x80 >> i;
 223                 if (pmcw->pim & mask) {
 224                         chp_id_init(&ssd->chpid[i]);
 225                         ssd->chpid[i].id = pmcw->chpid[i];
 226                 }
 227         }
 228 }
 229
 230 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
 231 {
 232         int i;
 233         int mask;
 234
 235         for (i = 0; i < 8; i++) {
 236                 mask = 0x80 >> i;
 237                 if (ssd->path_mask & mask)
 238                         if (!chp_is_registered(ssd->chpid[i]))
 239                                 chp_new(ssd->chpid[i]);
 240         }
 241 }
 242
 243 void css_update_ssd_info(struct subchannel *sch)
 244 {
 245         int ret;
 246
 247         ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
 248         if (ret)
 249                 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
 250
 251         ssd_register_chpids(&sch->ssd_info);
 252 }
 253
 254 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
 255                          char *buf)
 256 {
 257         struct subchannel *sch = to_subchannel(dev);
 258
 259         return sprintf(buf, "%01x\n", sch->st);
 260 }
 261
 262 static DEVICE_ATTR(type, 0444, type_show, NULL);
 263
 264 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 265                              char *buf)
 266 {
 267         struct subchannel *sch = to_subchannel(dev);
 268
 269         return sprintf(buf, "css:t%01X\n", sch->st);
 270 }
 271
 272 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 273
 274 static struct attribute *subch_attrs[] = {
 275         &dev_attr_type.attr,
 276         &dev_attr_modalias.attr,
 277         NULL,
 278 };
 279
 280 static struct attribute_group subch_attr_group = {
 281         .attrs = subch_attrs,
 282 };
 283
 284 static const struct attribute_group *default_subch_attr_groups[] = {
 285         &subch_attr_group,
 286         NULL,
 287 };
 288
 289 int css_register_subchannel(struct subchannel *sch)
 290 {
 291         int ret;
 292
 293         /* Initialize the subchannel structure */
 294         sch->dev.parent = &channel_subsystems[0]->device;
 295         sch->dev.bus = &css_bus_type;
 296         sch->dev.groups = default_subch_attr_groups;
 297         /*
 298          * We don't want to generate uevents for I/O subchannels that don't
 299          * have a working ccw device behind them since they will be
 300          * unregistered before they can be used anyway, so we delay the add
 301          * uevent until after device recognition was successful.
 302          * Note that we suppress the uevent for all subchannel types;
 303          * the subchannel driver can decide itself when it wants to inform
 304          * userspace of its existence.
 305          */
 306         dev_set_uevent_suppress(&sch->dev, 1);
 307         css_update_ssd_info(sch);
 308         /* make it known to the system */
 309         ret = css_sch_device_register(sch);
 310         if (ret) {
 311                 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
 312                               sch->schid.ssid, sch->schid.sch_no, ret);
 313                 return ret;
 314         }
 315         if (!sch->driver) {
 316                 /*
 317                  * No driver matched. Generate the uevent now so that
 318                  * a fitting driver module may be loaded based on the
 319                  * modalias.
 320                  */
 321                 dev_set_uevent_suppress(&sch->dev, 0);
 322                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 323         }
 324         return ret;
 325 }
 326
 327 static int css_probe_device(struct subchannel_id schid)
 328 {
 329         struct subchannel *sch;
 330         int ret;
 331
 332         sch = css_alloc_subchannel(schid);
 333         if (IS_ERR(sch))
 334                 return PTR_ERR(sch);
 335
 336         ret = css_register_subchannel(sch);
 337         if (ret)
 338                 put_device(&sch->dev);
 339
 340         return ret;
 341 }
 342
 343 static int
 344 check_subchannel(struct device * dev, void * data)
 345 {
 346         struct subchannel *sch;
 347         struct subchannel_id *schid = data;
 348
 349         sch = to_subchannel(dev);
 350         return schid_equal(&sch->schid, schid);
 351 }
 352
 353 struct subchannel *
 354 get_subchannel_by_schid(struct subchannel_id schid)
 355 {
 356         struct device *dev;
 357
 358         dev = bus_find_device(&css_bus_type, NULL,
 359                               &schid, check_subchannel);
 360
 361         return dev ? to_subchannel(dev) : NULL;
 362 }
 363
 364 /**
 365  * css_sch_is_valid() - check if a subchannel is valid
 366  * @schib: subchannel information block for the subchannel
 367  */
 368 int css_sch_is_valid(struct schib *schib)
 369 {
 370         if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
 371                 return 0;
 372         if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
 373                 return 0;
 374         return 1;
 375 }
 376 EXPORT_SYMBOL_GPL(css_sch_is_valid);
 377
 378 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
 379 {
 380         struct schib schib;
 381
 382         if (!slow) {
 383                 /* Will be done on the slow path. */
 384                 return -EAGAIN;
 385         }
 386         if (stsch_err(schid, &schib)) {
 387                 /* Subchannel is not provided. */
 388                 return -ENXIO;
 389         }
 390         if (!css_sch_is_valid(&schib)) {
 391                 /* Unusable - ignore. */
 392                 return 0;
 393         }
 394         CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
 395                       schid.sch_no);
 396
 397         return css_probe_device(schid);
 398 }
 399
 400 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
 401 {
 402         int ret = 0;
 403
 404         if (sch->driver) {
 405                 if (sch->driver->sch_event)
 406                         ret = sch->driver->sch_event(sch, slow);
 407                 else
 408                         dev_dbg(&sch->dev,
 409                                 "Got subchannel machine check but "
 410                                 "no sch_event handler provided.\n");
 411         }
 412         if (ret != 0 && ret != -EAGAIN) {
 413                 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
 414                               sch->schid.ssid, sch->schid.sch_no, ret);
 415         }
 416         return ret;
 417 }
 418
 419 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
 420 {
 421         struct subchannel *sch;
 422         int ret;
 423
 424         sch = get_subchannel_by_schid(schid);
 425         if (sch) {
 426                 ret = css_evaluate_known_subchannel(sch, slow);
 427                 put_device(&sch->dev);
 428         } else
 429                 ret = css_evaluate_new_subchannel(schid, slow);
 430         if (ret == -EAGAIN)
 431                 css_schedule_eval(schid);
 432 }
 433
 434 /**
 435  * css_sched_sch_todo - schedule a subchannel operation
 436  * @sch: subchannel
 437  * @todo: todo
 438  *
 439  * Schedule the operation identified by @todo to be performed on the slow path
 440  * workqueue. Do nothing if another operation with higher priority is already
 441  * scheduled. Needs to be called with subchannel lock held.
 442  */
 443 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
 444 {
 445         CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
 446                       sch->schid.ssid, sch->schid.sch_no, todo);
 447         if (sch->todo >= todo)
 448                 return;
 449         /* Get workqueue ref. */
 450         if (!get_device(&sch->dev))
 451                 return;
 452         sch->todo = todo;
 453         if (!queue_work(cio_work_q, &sch->todo_work)) {
 454                 /* Already queued, release workqueue ref. */
 455                 put_device(&sch->dev);
 456         }
 457 }
 458 EXPORT_SYMBOL_GPL(css_sched_sch_todo);
 459
 460 static void css_sch_todo(struct work_struct *work)
 461 {
 462         struct subchannel *sch;
 463         enum sch_todo todo;
 464         int ret;
 465
 466         sch = container_of(work, struct subchannel, todo_work);
 467         /* Find out todo. */
 468         spin_lock_irq(sch->lock);
 469         todo = sch->todo;
 470         CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
 471                       sch->schid.sch_no, todo);
 472         sch->todo = SCH_TODO_NOTHING;
 473         spin_unlock_irq(sch->lock);
 474         /* Perform todo. */
 475         switch (todo) {
 476         case SCH_TODO_NOTHING:
 477                 break;
 478         case SCH_TODO_EVAL:
 479                 ret = css_evaluate_known_subchannel(sch, 1);
 480                 if (ret == -EAGAIN) {
 481                         spin_lock_irq(sch->lock);
 482                         css_sched_sch_todo(sch, todo);
 483                         spin_unlock_irq(sch->lock);
 484                 }
 485                 break;
 486         case SCH_TODO_UNREG:
 487                 css_sch_device_unregister(sch);
 488                 break;
 489         }
 490         /* Release workqueue ref. */
 491         put_device(&sch->dev);
 492 }
 493
 494 static struct idset *slow_subchannel_set;
 495 static spinlock_t slow_subchannel_lock;
 496 static wait_queue_head_t css_eval_wq;
 497 static atomic_t css_eval_scheduled;
 498
 499 static int __init slow_subchannel_init(void)
 500 {
 501         spin_lock_init(&slow_subchannel_lock);
 502         atomic_set(&css_eval_scheduled, 0);
 503         init_waitqueue_head(&css_eval_wq);
 504         slow_subchannel_set = idset_sch_new();
 505         if (!slow_subchannel_set) {
 506                 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
 507                 return -ENOMEM;
 508         }
 509         return 0;
 510 }
 511
 512 static int slow_eval_known_fn(struct subchannel *sch, void *data)
 513 {
 514         int eval;
 515         int rc;
 516
 517         spin_lock_irq(&slow_subchannel_lock);
 518         eval = idset_sch_contains(slow_subchannel_set, sch->schid);
 519         idset_sch_del(slow_subchannel_set, sch->schid);
 520         spin_unlock_irq(&slow_subchannel_lock);
 521         if (eval) {
 522                 rc = css_evaluate_known_subchannel(sch, 1);
 523                 if (rc == -EAGAIN)
 524                         css_schedule_eval(sch->schid);
 525         }
 526         return 0;
 527 }
 528
 529 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
 530 {
 531         int eval;
 532         int rc = 0;
 533
 534         spin_lock_irq(&slow_subchannel_lock);
 535         eval = idset_sch_contains(slow_subchannel_set, schid);
 536         idset_sch_del(slow_subchannel_set, schid);
 537         spin_unlock_irq(&slow_subchannel_lock);
 538         if (eval) {
 539                 rc = css_evaluate_new_subchannel(schid, 1);
 540                 switch (rc) {
 541                 case -EAGAIN:
 542                         css_schedule_eval(schid);
 543                         rc = 0;
 544                         break;
 545                 case -ENXIO:
 546                 case -ENOMEM:
 547                 case -EIO:
 548                         /* These should abort looping */
 549                         spin_lock_irq(&slow_subchannel_lock);
 550                         idset_sch_del_subseq(slow_subchannel_set, schid);
 551                         spin_unlock_irq(&slow_subchannel_lock);
 552                         break;
 553                 default:
 554                         rc = 0;
 555                 }
 556         }
 557         return rc;
 558 }
 559
 560 static void css_slow_path_func(struct work_struct *unused)
 561 {
 562         unsigned long flags;
 563
 564         CIO_TRACE_EVENT(4, "slowpath");
 565         for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
 566                                    NULL);
 567         spin_lock_irqsave(&slow_subchannel_lock, flags);
 568         if (idset_is_empty(slow_subchannel_set)) {
 569                 atomic_set(&css_eval_scheduled, 0);
 570                 wake_up(&css_eval_wq);
 571         }
 572         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 573 }
 574
 575 static DECLARE_WORK(slow_path_work, css_slow_path_func);
 576 struct workqueue_struct *cio_work_q;
 577
 578 void css_schedule_eval(struct subchannel_id schid)
 579 {
 580         unsigned long flags;
 581
 582         spin_lock_irqsave(&slow_subchannel_lock, flags);
 583         idset_sch_add(slow_subchannel_set, schid);
 584         atomic_set(&css_eval_scheduled, 1);
 585         queue_work(cio_work_q, &slow_path_work);
 586         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 587 }
 588
 589 void css_schedule_eval_all(void)
 590 {
 591         unsigned long flags;
 592
 593         spin_lock_irqsave(&slow_subchannel_lock, flags);
 594         idset_fill(slow_subchannel_set);
 595         atomic_set(&css_eval_scheduled, 1);
 596         queue_work(cio_work_q, &slow_path_work);
 597         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 598 }
 599
 600 static int __unset_registered(struct device *dev, void *data)
 601 {
 602         struct idset *set = data;
 603         struct subchannel *sch = to_subchannel(dev);
 604
 605         idset_sch_del(set, sch->schid);
 606         return 0;
 607 }
 608
 609 static void css_schedule_eval_all_unreg(void)
 610 {
 611         unsigned long flags;
 612         struct idset *unreg_set;
 613
 614         /* Find unregistered subchannels. */
 615         unreg_set = idset_sch_new();
 616         if (!unreg_set) {
 617                 /* Fallback. */
 618                 css_schedule_eval_all();
 619                 return;
 620         }
 621         idset_fill(unreg_set);
 622         bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
 623         /* Apply to slow_subchannel_set. */
 624         spin_lock_irqsave(&slow_subchannel_lock, flags);
 625         idset_add_set(slow_subchannel_set, unreg_set);
 626         atomic_set(&css_eval_scheduled, 1);
 627         queue_work(cio_work_q, &slow_path_work);
 628         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 629         idset_free(unreg_set);
 630 }
 631
 632 void css_wait_for_slow_path(void)
 633 {
 634         flush_workqueue(cio_work_q);
 635 }
 636
 637 /* Schedule reprobing of all unregistered subchannels. */
 638 void css_schedule_reprobe(void)
 639 {
 640         css_schedule_eval_all_unreg();
 641 }
 642 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 643
 644 /*
 645  * Called from the machine check handler for subchannel report words.
 646  */
 647 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 648 {
 649         struct subchannel_id mchk_schid;
 650         struct subchannel *sch;
 651
 652         if (overflow) {
 653                 css_schedule_eval_all();
 654                 return;
 655         }
 656         CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
 657                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 658                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 659                       crw0->erc, crw0->rsid);
 660         if (crw1)
 661                 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
 662                               "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 663                               crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
 664                               crw1->anc, crw1->erc, crw1->rsid);
 665         init_subchannel_id(&mchk_schid);
 666         mchk_schid.sch_no = crw0->rsid;
 667         if (crw1)
 668                 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
 669
 670         if (crw0->erc == CRW_ERC_PMOD) {
 671                 sch = get_subchannel_by_schid(mchk_schid);
 672                 if (sch) {
 673                         css_update_ssd_info(sch);
 674                         put_device(&sch->dev);
 675                 }
 676         }
 677         /*
 678          * Since we are always presented with IPI in the CRW, we have to
 679          * use stsch() to find out if the subchannel in question has come
 680          * or gone.
 681          */
 682         css_evaluate_subchannel(mchk_schid, 0);
 683 }
 684
 685 static void __init
 686 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
 687 {
 688         struct cpuid cpu_id;
 689
 690         if (css_general_characteristics.mcss) {
 691                 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
 692                 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
 693         } else {
 694 #ifdef CONFIG_SMP
 695                 css->global_pgid.pgid_high.cpu_addr = stap();
 696 #else
 697                 css->global_pgid.pgid_high.cpu_addr = 0;
 698 #endif
 699         }
 700         get_cpu_id(&cpu_id);
 701         css->global_pgid.cpu_id = cpu_id.ident;
 702         css->global_pgid.cpu_model = cpu_id.machine;
 703         css->global_pgid.tod_high = tod_high;
 704
 705 }
 706
 707 static void
 708 channel_subsystem_release(struct device *dev)
 709 {
 710         struct channel_subsystem *css;
 711
 712         css = to_css(dev);
 713         mutex_destroy(&css->mutex);
 714         if (css->pseudo_subchannel) {
 715                 /* Implies that it has been generated but never registered. */
 716                 css_subchannel_release(&css->pseudo_subchannel->dev);
 717                 css->pseudo_subchannel = NULL;
 718         }
 719         kfree(css);
 720 }
 721
 722 static ssize_t
 723 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
 724                    char *buf)
 725 {
 726         struct channel_subsystem *css = to_css(dev);
 727         int ret;
 728
 729         if (!css)
 730                 return 0;
 731         mutex_lock(&css->mutex);
 732         ret = sprintf(buf, "%x\n", css->cm_enabled);
 733         mutex_unlock(&css->mutex);
 734         return ret;
 735 }
 736
 737 static ssize_t
 738 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
 739                     const char *buf, size_t count)
 740 {
 741         struct channel_subsystem *css = to_css(dev);
 742         int ret;
 743         unsigned long val;
 744
 745         ret = kstrtoul(buf, 16, &val);
 746         if (ret)
 747                 return ret;
 748         mutex_lock(&css->mutex);
 749         switch (val) {
 750         case 0:
 751                 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
 752                 break;
 753         case 1:
 754                 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
 755                 break;
 756         default:
 757                 ret = -EINVAL;
 758         }
 759         mutex_unlock(&css->mutex);
 760         return ret < 0 ? ret : count;
 761 }
 762
 763 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
 764
 765 static int __init setup_css(int nr)
 766 {
 767         u32 tod_high;
 768         int ret;
 769         struct channel_subsystem *css;
 770
 771         css = channel_subsystems[nr];
 772         memset(css, 0, sizeof(struct channel_subsystem));
 773         css->pseudo_subchannel =
 774                 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
 775         if (!css->pseudo_subchannel)
 776                 return -ENOMEM;
 777         css->pseudo_subchannel->dev.parent = &css->device;
 778         css->pseudo_subchannel->dev.release = css_subchannel_release;
 779         dev_set_name(&css->pseudo_subchannel->dev, "defunct");
 780         mutex_init(&css->pseudo_subchannel->reg_mutex);
 781         ret = css_sch_create_locks(css->pseudo_subchannel);
 782         if (ret) {
 783                 kfree(css->pseudo_subchannel);
 784                 return ret;
 785         }
 786         mutex_init(&css->mutex);
 787         css->valid = 1;
 788         css->cssid = nr;
 789         dev_set_name(&css->device, "css%x", nr);
 790         css->device.release = channel_subsystem_release;
 791         tod_high = (u32) (get_tod_clock() >> 32);
 792         css_generate_pgid(css, tod_high);
 793         return 0;
 794 }
 795
 796 static int css_reboot_event(struct notifier_block *this,
 797                             unsigned long event,
 798                             void *ptr)
 799 {
 800         int ret, i;
 801
 802         ret = NOTIFY_DONE;
 803         for (i = 0; i <= __MAX_CSSID; i++) {
 804                 struct channel_subsystem *css;
 805
 806                 css = channel_subsystems[i];
 807                 mutex_lock(&css->mutex);
 808                 if (css->cm_enabled)
 809                         if (chsc_secm(css, 0))
 810                                 ret = NOTIFY_BAD;
 811                 mutex_unlock(&css->mutex);
 812         }
 813
 814         return ret;
 815 }
 816
 817 static struct notifier_block css_reboot_notifier = {
 818         .notifier_call = css_reboot_event,
 819 };
 820
 821 /*
 822  * Since the css devices are neither on a bus nor have a class
 823  * nor have a special device type, we cannot stop/restart channel
 824  * path measurements via the normal suspend/resume callbacks, but have
 825  * to use notifiers.
 826  */
 827 static int css_power_event(struct notifier_block *this, unsigned long event,
 828                            void *ptr)
 829 {
 830         int ret, i;
 831
 832         switch (event) {
 833         case PM_HIBERNATION_PREPARE:
 834         case PM_SUSPEND_PREPARE:
 835                 ret = NOTIFY_DONE;
 836                 for (i = 0; i <= __MAX_CSSID; i++) {
 837                         struct channel_subsystem *css;
 838
 839                         css = channel_subsystems[i];
 840                         mutex_lock(&css->mutex);
 841                         if (!css->cm_enabled) {
 842                                 mutex_unlock(&css->mutex);
 843                                 continue;
 844                         }
 845                         ret = __chsc_do_secm(css, 0);
 846                         ret = notifier_from_errno(ret);
 847                         mutex_unlock(&css->mutex);
 848                 }
 849                 break;
 850         case PM_POST_HIBERNATION:
 851         case PM_POST_SUSPEND:
 852                 ret = NOTIFY_DONE;
 853                 for (i = 0; i <= __MAX_CSSID; i++) {
 854                         struct channel_subsystem *css;
 855
 856                         css = channel_subsystems[i];
 857                         mutex_lock(&css->mutex);
 858                         if (!css->cm_enabled) {
 859                                 mutex_unlock(&css->mutex);
 860                                 continue;
 861                         }
 862                         ret = __chsc_do_secm(css, 1);
 863                         ret = notifier_from_errno(ret);
 864                         mutex_unlock(&css->mutex);
 865                 }
 866                 /* search for subchannels, which appeared during hibernation */
 867                 css_schedule_reprobe();
 868                 break;
 869         default:
 870                 ret = NOTIFY_DONE;
 871         }
 872         return ret;
 873
 874 }
 875 static struct notifier_block css_power_notifier = {
 876         .notifier_call = css_power_event,
 877 };
 878
 879 /*
 880  * Now that the driver core is running, we can setup our channel subsystem.
 881  * The struct subchannel's are created during probing.
 882  */
 883 static int __init css_bus_init(void)
 884 {
 885         int ret, i;
 886
 887         ret = chsc_init();
 888         if (ret)
 889                 return ret;
 890
 891         chsc_determine_css_characteristics();
 892         /* Try to enable MSS. */
 893         ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
 894         if (ret)
 895                 max_ssid = 0;
 896         else /* Success. */
 897                 max_ssid = __MAX_SSID;
 898
 899         ret = slow_subchannel_init();
 900         if (ret)
 901                 goto out;
 902
 903         ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
 904         if (ret)
 905                 goto out;
 906
 907         if ((ret = bus_register(&css_bus_type)))
 908                 goto out;
 909
 910         /* Setup css structure. */
 911         for (i = 0; i <= __MAX_CSSID; i++) {
 912                 struct channel_subsystem *css;
 913
 914                 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
 915                 if (!css) {
 916                         ret = -ENOMEM;
 917                         goto out_unregister;
 918                 }
 919                 channel_subsystems[i] = css;
 920                 ret = setup_css(i);
 921                 if (ret) {
 922                         kfree(channel_subsystems[i]);
 923                         goto out_unregister;
 924                 }
 925                 ret = device_register(&css->device);
 926                 if (ret) {
 927                         put_device(&css->device);
 928                         goto out_unregister;
 929                 }
 930                 if (css_chsc_characteristics.secm) {
 931                         ret = device_create_file(&css->device,
 932                                                  &dev_attr_cm_enable);
 933                         if (ret)
 934                                 goto out_device;
 935                 }
 936                 ret = device_register(&css->pseudo_subchannel->dev);
 937                 if (ret) {
 938                         put_device(&css->pseudo_subchannel->dev);
 939                         goto out_file;
 940                 }
 941         }
 942         ret = register_reboot_notifier(&css_reboot_notifier);
 943         if (ret)
 944                 goto out_unregister;
 945         ret = register_pm_notifier(&css_power_notifier);
 946         if (ret) {
 947                 unregister_reboot_notifier(&css_reboot_notifier);
 948                 goto out_unregister;
 949         }
 950         css_init_done = 1;
 951
 952         /* Enable default isc for I/O subchannels. */
 953         isc_register(IO_SCH_ISC);
 954
 955         return 0;
 956 out_file:
 957         if (css_chsc_characteristics.secm)
 958                 device_remove_file(&channel_subsystems[i]->device,
 959                                    &dev_attr_cm_enable);
 960 out_device:
 961         device_unregister(&channel_subsystems[i]->device);
 962 out_unregister:
 963         while (i > 0) {
 964                 struct channel_subsystem *css;
 965
 966                 i--;
 967                 css = channel_subsystems[i];
 968                 device_unregister(&css->pseudo_subchannel->dev);
 969                 css->pseudo_subchannel = NULL;
 970                 if (css_chsc_characteristics.secm)
 971                         device_remove_file(&css->device,
 972                                            &dev_attr_cm_enable);
 973                 device_unregister(&css->device);
 974         }
 975         bus_unregister(&css_bus_type);
 976 out:
 977         crw_unregister_handler(CRW_RSC_SCH);
 978         idset_free(slow_subchannel_set);
 979         chsc_init_cleanup();
 980         pr_alert("The CSS device driver initialization failed with "
 981                  "errno=%d\n", ret);
 982         return ret;
 983 }
 984
 985 static void __init css_bus_cleanup(void)
 986 {
 987         struct channel_subsystem *css;
 988         int i;
 989
 990         for (i = 0; i <= __MAX_CSSID; i++) {
 991                 css = channel_subsystems[i];
 992                 device_unregister(&css->pseudo_subchannel->dev);
 993                 css->pseudo_subchannel = NULL;
 994                 if (css_chsc_characteristics.secm)
 995                         device_remove_file(&css->device, &dev_attr_cm_enable);
 996                 device_unregister(&css->device);
 997         }
 998         bus_unregister(&css_bus_type);
 999         crw_unregister_handler(CRW_RSC_SCH);
1000         idset_free(slow_subchannel_set);
1001         chsc_init_cleanup();
1002         isc_unregister(IO_SCH_ISC);
1003 }
1004
1005 static int __init channel_subsystem_init(void)
1006 {
1007         int ret;
1008
1009         ret = css_bus_init();
1010         if (ret)
1011                 return ret;
1012         cio_work_q = create_singlethread_workqueue("cio");
1013         if (!cio_work_q) {
1014                 ret = -ENOMEM;
1015                 goto out_bus;
1016         }
1017         ret = io_subchannel_init();
1018         if (ret)
1019                 goto out_wq;
1020
1021         return ret;
1022 out_wq:
1023         destroy_workqueue(cio_work_q);
1024 out_bus:
1025         css_bus_cleanup();
1026         return ret;
1027 }
1028 subsys_initcall(channel_subsystem_init);
1029
1030 static int css_settle(struct device_driver *drv, void *unused)
1031 {
1032         struct css_driver *cssdrv = to_cssdriver(drv);
1033
1034         if (cssdrv->settle)
1035                 return cssdrv->settle();
1036         return 0;
1037 }
1038
1039 int css_complete_work(void)
1040 {
1041         int ret;
1042
1043         /* Wait for the evaluation of subchannels to finish. */
1044         ret = wait_event_interruptible(css_eval_wq,
1045                                        atomic_read(&css_eval_scheduled) == 0);
1046         if (ret)
1047                 return -EINTR;
1048         flush_workqueue(cio_work_q);
1049         /* Wait for the subchannel type specific initialization to finish */
1050         return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1051 }
1052
1053
1054 /*
1055  * Wait for the initialization of devices to finish, to make sure we are
1056  * done with our setup if the search for the root device starts.
1057  */
1058 static int __init channel_subsystem_init_sync(void)
1059 {
1060         /* Register subchannels which are already in use. */
1061         cio_register_early_subchannels();
1062         /* Start initial subchannel evaluation. */
1063         css_schedule_eval_all();
1064         css_complete_work();
1065         return 0;
1066 }
1067 subsys_initcall_sync(channel_subsystem_init_sync);
1068
1069 void channel_subsystem_reinit(void)
1070 {
1071         struct channel_path *chp;
1072         struct chp_id chpid;
1073
1074         chsc_enable_facility(CHSC_SDA_OC_MSS);
1075         chp_id_for_each(&chpid) {
1076                 chp = chpid_to_chp(chpid);
1077                 if (chp)
1078                         chp_update_desc(chp);
1079         }
1080 }
1081
1082 #ifdef CONFIG_PROC_FS
1083 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1084                                 size_t count, loff_t *ppos)
1085 {
1086         int ret;
1087
1088         /* Handle pending CRW's. */
1089         crw_wait_for_channel_report();
1090         ret = css_complete_work();
1091
1092         return ret ? ret : count;
1093 }
1094
1095 static const struct file_operations cio_settle_proc_fops = {
1096         .open = nonseekable_open,
1097         .write = cio_settle_write,
1098         .llseek = no_llseek,
1099 };
1100
1101 static int __init cio_settle_init(void)
1102 {
1103         struct proc_dir_entry *entry;
1104
1105         entry = proc_create("cio_settle", S_IWUSR, NULL,
1106                             &cio_settle_proc_fops);
1107         if (!entry)
1108                 return -ENOMEM;
1109         return 0;
1110 }
1111 device_initcall(cio_settle_init);
1112 #endif /*CONFIG_PROC_FS*/
1113
1114 int sch_is_pseudo_sch(struct subchannel *sch)
1115 {
1116         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1117 }
1118
1119 static int css_bus_match(struct device *dev, struct device_driver *drv)
1120 {
1121         struct subchannel *sch = to_subchannel(dev);
1122         struct css_driver *driver = to_cssdriver(drv);
1123         struct css_device_id *id;
1124
1125         for (id = driver->subchannel_type; id->match_flags; id++) {
1126                 if (sch->st == id->type)
1127                         return 1;
1128         }
1129
1130         return 0;
1131 }
1132
1133 static int css_probe(struct device *dev)
1134 {
1135         struct subchannel *sch;
1136         int ret;
1137
1138         sch = to_subchannel(dev);
1139         sch->driver = to_cssdriver(dev->driver);
1140         ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1141         if (ret)
1142                 sch->driver = NULL;
1143         return ret;
1144 }
1145
1146 static int css_remove(struct device *dev)
1147 {
1148         struct subchannel *sch;
1149         int ret;
1150
1151         sch = to_subchannel(dev);
1152         ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1153         sch->driver = NULL;
1154         return ret;
1155 }
1156
1157 static void css_shutdown(struct device *dev)
1158 {
1159         struct subchannel *sch;
1160
1161         sch = to_subchannel(dev);
1162         if (sch->driver && sch->driver->shutdown)
1163                 sch->driver->shutdown(sch);
1164 }
1165
1166 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1167 {
1168         struct subchannel *sch = to_subchannel(dev);
1169         int ret;
1170
1171         ret = add_uevent_var(env, "ST=%01X", sch->st);
1172         if (ret)
1173                 return ret;
1174         ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1175         return ret;
1176 }
1177
1178 static int css_pm_prepare(struct device *dev)
1179 {
1180         struct subchannel *sch = to_subchannel(dev);
1181         struct css_driver *drv;
1182
1183         if (mutex_is_locked(&sch->reg_mutex))
1184                 return -EAGAIN;
1185         if (!sch->dev.driver)
1186                 return 0;
1187         drv = to_cssdriver(sch->dev.driver);
1188         /* Notify drivers that they may not register children. */
1189         return drv->prepare ? drv->prepare(sch) : 0;
1190 }
1191
1192 static void css_pm_complete(struct device *dev)
1193 {
1194         struct subchannel *sch = to_subchannel(dev);
1195         struct css_driver *drv;
1196
1197         if (!sch->dev.driver)
1198                 return;
1199         drv = to_cssdriver(sch->dev.driver);
1200         if (drv->complete)
1201                 drv->complete(sch);
1202 }
1203
1204 static int css_pm_freeze(struct device *dev)
1205 {
1206         struct subchannel *sch = to_subchannel(dev);
1207         struct css_driver *drv;
1208
1209         if (!sch->dev.driver)
1210                 return 0;
1211         drv = to_cssdriver(sch->dev.driver);
1212         return drv->freeze ? drv->freeze(sch) : 0;
1213 }
1214
1215 static int css_pm_thaw(struct device *dev)
1216 {
1217         struct subchannel *sch = to_subchannel(dev);
1218         struct css_driver *drv;
1219
1220         if (!sch->dev.driver)
1221                 return 0;
1222         drv = to_cssdriver(sch->dev.driver);
1223         return drv->thaw ? drv->thaw(sch) : 0;
1224 }
1225
1226 static int css_pm_restore(struct device *dev)
1227 {
1228         struct subchannel *sch = to_subchannel(dev);
1229         struct css_driver *drv;
1230
1231         css_update_ssd_info(sch);
1232         if (!sch->dev.driver)
1233                 return 0;
1234         drv = to_cssdriver(sch->dev.driver);
1235         return drv->restore ? drv->restore(sch) : 0;
1236 }
1237
1238 static const struct dev_pm_ops css_pm_ops = {
1239         .prepare = css_pm_prepare,
1240         .complete = css_pm_complete,
1241         .freeze = css_pm_freeze,
1242         .thaw = css_pm_thaw,
1243         .restore = css_pm_restore,
1244 };
1245
1246 static struct bus_type css_bus_type = {
1247         .name     = "css",
1248         .match    = css_bus_match,
1249         .probe    = css_probe,
1250         .remove   = css_remove,
1251         .shutdown = css_shutdown,
1252         .uevent   = css_uevent,
1253         .pm = &css_pm_ops,
1254 };
1255
1256 /**
1257  * css_driver_register - register a css driver
1258  * @cdrv: css driver to register
1259  *
1260  * This is mainly a wrapper around driver_register that sets name
1261  * and bus_type in the embedded struct device_driver correctly.
1262  */
1263 int css_driver_register(struct css_driver *cdrv)
1264 {
1265         cdrv->drv.bus = &css_bus_type;
1266         return driver_register(&cdrv->drv);
1267 }
1268 EXPORT_SYMBOL_GPL(css_driver_register);
1269
1270 /**
1271  * css_driver_unregister - unregister a css driver
1272  * @cdrv: css driver to unregister
1273  *
1274  * This is a wrapper around driver_unregister.
1275  */
1276 void css_driver_unregister(struct css_driver *cdrv)
1277 {
1278         driver_unregister(&cdrv->drv);
1279 }
1280 EXPORT_SYMBOL_GPL(css_driver_unregister);
1281
1282 MODULE_LICENSE("GPL");