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) || !css_sch_is_valid(&schib)) {
 381                 /* Unusable - ignore. */
 382                 return 0;
 383         }
 384         CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
 385                       schid.sch_no);
 386
 387         return css_probe_device(schid);
 388 }
 389
 390 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
 391 {
 392         int ret = 0;
 393
 394         if (sch->driver) {
 395                 if (sch->driver->sch_event)
 396                         ret = sch->driver->sch_event(sch, slow);
 397                 else
 398                         dev_dbg(&sch->dev,
 399                                 "Got subchannel machine check but "
 400                                 "no sch_event handler provided.\n");
 401         }
 402         if (ret != 0 && ret != -EAGAIN) {
 403                 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
 404                               sch->schid.ssid, sch->schid.sch_no, ret);
 405         }
 406         return ret;
 407 }
 408
 409 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
 410 {
 411         struct subchannel *sch;
 412         int ret;
 413
 414         sch = get_subchannel_by_schid(schid);
 415         if (sch) {
 416                 ret = css_evaluate_known_subchannel(sch, slow);
 417                 put_device(&sch->dev);
 418         } else
 419                 ret = css_evaluate_new_subchannel(schid, slow);
 420         if (ret == -EAGAIN)
 421                 css_schedule_eval(schid);
 422 }
 423
 424 /**
 425  * css_sched_sch_todo - schedule a subchannel operation
 426  * @sch: subchannel
 427  * @todo: todo
 428  *
 429  * Schedule the operation identified by @todo to be performed on the slow path
 430  * workqueue. Do nothing if another operation with higher priority is already
 431  * scheduled. Needs to be called with subchannel lock held.
 432  */
 433 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
 434 {
 435         CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
 436                       sch->schid.ssid, sch->schid.sch_no, todo);
 437         if (sch->todo >= todo)
 438                 return;
 439         /* Get workqueue ref. */
 440         if (!get_device(&sch->dev))
 441                 return;
 442         sch->todo = todo;
 443         if (!queue_work(cio_work_q, &sch->todo_work)) {
 444                 /* Already queued, release workqueue ref. */
 445                 put_device(&sch->dev);
 446         }
 447 }
 448 EXPORT_SYMBOL_GPL(css_sched_sch_todo);
 449
 450 static void css_sch_todo(struct work_struct *work)
 451 {
 452         struct subchannel *sch;
 453         enum sch_todo todo;
 454         int ret;
 455
 456         sch = container_of(work, struct subchannel, todo_work);
 457         /* Find out todo. */
 458         spin_lock_irq(sch->lock);
 459         todo = sch->todo;
 460         CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
 461                       sch->schid.sch_no, todo);
 462         sch->todo = SCH_TODO_NOTHING;
 463         spin_unlock_irq(sch->lock);
 464         /* Perform todo. */
 465         switch (todo) {
 466         case SCH_TODO_NOTHING:
 467                 break;
 468         case SCH_TODO_EVAL:
 469                 ret = css_evaluate_known_subchannel(sch, 1);
 470                 if (ret == -EAGAIN) {
 471                         spin_lock_irq(sch->lock);
 472                         css_sched_sch_todo(sch, todo);
 473                         spin_unlock_irq(sch->lock);
 474                 }
 475                 break;
 476         case SCH_TODO_UNREG:
 477                 css_sch_device_unregister(sch);
 478                 break;
 479         }
 480         /* Release workqueue ref. */
 481         put_device(&sch->dev);
 482 }
 483
 484 static struct idset *slow_subchannel_set;
 485 static spinlock_t slow_subchannel_lock;
 486 static wait_queue_head_t css_eval_wq;
 487 static atomic_t css_eval_scheduled;
 488
 489 static int __init slow_subchannel_init(void)
 490 {
 491         spin_lock_init(&slow_subchannel_lock);
 492         atomic_set(&css_eval_scheduled, 0);
 493         init_waitqueue_head(&css_eval_wq);
 494         slow_subchannel_set = idset_sch_new();
 495         if (!slow_subchannel_set) {
 496                 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
 497                 return -ENOMEM;
 498         }
 499         return 0;
 500 }
 501
 502 static int slow_eval_known_fn(struct subchannel *sch, void *data)
 503 {
 504         int eval;
 505         int rc;
 506
 507         spin_lock_irq(&slow_subchannel_lock);
 508         eval = idset_sch_contains(slow_subchannel_set, sch->schid);
 509         idset_sch_del(slow_subchannel_set, sch->schid);
 510         spin_unlock_irq(&slow_subchannel_lock);
 511         if (eval) {
 512                 rc = css_evaluate_known_subchannel(sch, 1);
 513                 if (rc == -EAGAIN)
 514                         css_schedule_eval(sch->schid);
 515         }
 516         return 0;
 517 }
 518
 519 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
 520 {
 521         int eval;
 522         int rc = 0;
 523
 524         spin_lock_irq(&slow_subchannel_lock);
 525         eval = idset_sch_contains(slow_subchannel_set, schid);
 526         idset_sch_del(slow_subchannel_set, schid);
 527         spin_unlock_irq(&slow_subchannel_lock);
 528         if (eval) {
 529                 rc = css_evaluate_new_subchannel(schid, 1);
 530                 switch (rc) {
 531                 case -EAGAIN:
 532                         css_schedule_eval(schid);
 533                         rc = 0;
 534                         break;
 535                 case -ENXIO:
 536                 case -ENOMEM:
 537                 case -EIO:
 538                         /* These should abort looping */
 539                         break;
 540                 default:
 541                         rc = 0;
 542                 }
 543         }
 544         return rc;
 545 }
 546
 547 static void css_slow_path_func(struct work_struct *unused)
 548 {
 549         unsigned long flags;
 550
 551         CIO_TRACE_EVENT(4, "slowpath");
 552         for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
 553                                    NULL);
 554         spin_lock_irqsave(&slow_subchannel_lock, flags);
 555         if (idset_is_empty(slow_subchannel_set)) {
 556                 atomic_set(&css_eval_scheduled, 0);
 557                 wake_up(&css_eval_wq);
 558         }
 559         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 560 }
 561
 562 static DECLARE_WORK(slow_path_work, css_slow_path_func);
 563 struct workqueue_struct *cio_work_q;
 564
 565 void css_schedule_eval(struct subchannel_id schid)
 566 {
 567         unsigned long flags;
 568
 569         spin_lock_irqsave(&slow_subchannel_lock, flags);
 570         idset_sch_add(slow_subchannel_set, schid);
 571         atomic_set(&css_eval_scheduled, 1);
 572         queue_work(cio_work_q, &slow_path_work);
 573         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 574 }
 575
 576 void css_schedule_eval_all(void)
 577 {
 578         unsigned long flags;
 579
 580         spin_lock_irqsave(&slow_subchannel_lock, flags);
 581         idset_fill(slow_subchannel_set);
 582         atomic_set(&css_eval_scheduled, 1);
 583         queue_work(cio_work_q, &slow_path_work);
 584         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 585 }
 586
 587 static int __unset_registered(struct device *dev, void *data)
 588 {
 589         struct idset *set = data;
 590         struct subchannel *sch = to_subchannel(dev);
 591
 592         idset_sch_del(set, sch->schid);
 593         return 0;
 594 }
 595
 596 static void css_schedule_eval_all_unreg(void)
 597 {
 598         unsigned long flags;
 599         struct idset *unreg_set;
 600
 601         /* Find unregistered subchannels. */
 602         unreg_set = idset_sch_new();
 603         if (!unreg_set) {
 604                 /* Fallback. */
 605                 css_schedule_eval_all();
 606                 return;
 607         }
 608         idset_fill(unreg_set);
 609         bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
 610         /* Apply to slow_subchannel_set. */
 611         spin_lock_irqsave(&slow_subchannel_lock, flags);
 612         idset_add_set(slow_subchannel_set, unreg_set);
 613         atomic_set(&css_eval_scheduled, 1);
 614         queue_work(cio_work_q, &slow_path_work);
 615         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 616         idset_free(unreg_set);
 617 }
 618
 619 void css_wait_for_slow_path(void)
 620 {
 621         flush_workqueue(cio_work_q);
 622 }
 623
 624 /* Schedule reprobing of all unregistered subchannels. */
 625 void css_schedule_reprobe(void)
 626 {
 627         css_schedule_eval_all_unreg();
 628 }
 629 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 630
 631 /*
 632  * Called from the machine check handler for subchannel report words.
 633  */
 634 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 635 {
 636         struct subchannel_id mchk_schid;
 637         struct subchannel *sch;
 638
 639         if (overflow) {
 640                 css_schedule_eval_all();
 641                 return;
 642         }
 643         CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
 644                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 645                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 646                       crw0->erc, crw0->rsid);
 647         if (crw1)
 648                 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
 649                               "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 650                               crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
 651                               crw1->anc, crw1->erc, crw1->rsid);
 652         init_subchannel_id(&mchk_schid);
 653         mchk_schid.sch_no = crw0->rsid;
 654         if (crw1)
 655                 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
 656
 657         if (crw0->erc == CRW_ERC_PMOD) {
 658                 sch = get_subchannel_by_schid(mchk_schid);
 659                 if (sch) {
 660                         css_update_ssd_info(sch);
 661                         put_device(&sch->dev);
 662                 }
 663         }
 664         /*
 665          * Since we are always presented with IPI in the CRW, we have to
 666          * use stsch() to find out if the subchannel in question has come
 667          * or gone.
 668          */
 669         css_evaluate_subchannel(mchk_schid, 0);
 670 }
 671
 672 static void __init
 673 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
 674 {
 675         struct cpuid cpu_id;
 676
 677         if (css_general_characteristics.mcss) {
 678                 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
 679                 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
 680         } else {
 681 #ifdef CONFIG_SMP
 682                 css->global_pgid.pgid_high.cpu_addr = stap();
 683 #else
 684                 css->global_pgid.pgid_high.cpu_addr = 0;
 685 #endif
 686         }
 687         get_cpu_id(&cpu_id);
 688         css->global_pgid.cpu_id = cpu_id.ident;
 689         css->global_pgid.cpu_model = cpu_id.machine;
 690         css->global_pgid.tod_high = tod_high;
 691
 692 }
 693
 694 static void
 695 channel_subsystem_release(struct device *dev)
 696 {
 697         struct channel_subsystem *css;
 698
 699         css = to_css(dev);
 700         mutex_destroy(&css->mutex);
 701         if (css->pseudo_subchannel) {
 702                 /* Implies that it has been generated but never registered. */
 703                 css_subchannel_release(&css->pseudo_subchannel->dev);
 704                 css->pseudo_subchannel = NULL;
 705         }
 706         kfree(css);
 707 }
 708
 709 static ssize_t
 710 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
 711                    char *buf)
 712 {
 713         struct channel_subsystem *css = to_css(dev);
 714         int ret;
 715
 716         if (!css)
 717                 return 0;
 718         mutex_lock(&css->mutex);
 719         ret = sprintf(buf, "%x\n", css->cm_enabled);
 720         mutex_unlock(&css->mutex);
 721         return ret;
 722 }
 723
 724 static ssize_t
 725 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
 726                     const char *buf, size_t count)
 727 {
 728         struct channel_subsystem *css = to_css(dev);
 729         int ret;
 730         unsigned long val;
 731
 732         ret = strict_strtoul(buf, 16, &val);
 733         if (ret)
 734                 return ret;
 735         mutex_lock(&css->mutex);
 736         switch (val) {
 737         case 0:
 738                 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
 739                 break;
 740         case 1:
 741                 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
 742                 break;
 743         default:
 744                 ret = -EINVAL;
 745         }
 746         mutex_unlock(&css->mutex);
 747         return ret < 0 ? ret : count;
 748 }
 749
 750 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
 751
 752 static int __init setup_css(int nr)
 753 {
 754         u32 tod_high;
 755         int ret;
 756         struct channel_subsystem *css;
 757
 758         css = channel_subsystems[nr];
 759         memset(css, 0, sizeof(struct channel_subsystem));
 760         css->pseudo_subchannel =
 761                 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
 762         if (!css->pseudo_subchannel)
 763                 return -ENOMEM;
 764         css->pseudo_subchannel->dev.parent = &css->device;
 765         css->pseudo_subchannel->dev.release = css_subchannel_release;
 766         dev_set_name(&css->pseudo_subchannel->dev, "defunct");
 767         mutex_init(&css->pseudo_subchannel->reg_mutex);
 768         ret = cio_create_sch_lock(css->pseudo_subchannel);
 769         if (ret) {
 770                 kfree(css->pseudo_subchannel);
 771                 return ret;
 772         }
 773         mutex_init(&css->mutex);
 774         css->valid = 1;
 775         css->cssid = nr;
 776         dev_set_name(&css->device, "css%x", nr);
 777         css->device.release = channel_subsystem_release;
 778         tod_high = (u32) (get_clock() >> 32);
 779         css_generate_pgid(css, tod_high);
 780         return 0;
 781 }
 782
 783 static int css_reboot_event(struct notifier_block *this,
 784                             unsigned long event,
 785                             void *ptr)
 786 {
 787         int ret, i;
 788
 789         ret = NOTIFY_DONE;
 790         for (i = 0; i <= __MAX_CSSID; i++) {
 791                 struct channel_subsystem *css;
 792
 793                 css = channel_subsystems[i];
 794                 mutex_lock(&css->mutex);
 795                 if (css->cm_enabled)
 796                         if (chsc_secm(css, 0))
 797                                 ret = NOTIFY_BAD;
 798                 mutex_unlock(&css->mutex);
 799         }
 800
 801         return ret;
 802 }
 803
 804 static struct notifier_block css_reboot_notifier = {
 805         .notifier_call = css_reboot_event,
 806 };
 807
 808 /*
 809  * Since the css devices are neither on a bus nor have a class
 810  * nor have a special device type, we cannot stop/restart channel
 811  * path measurements via the normal suspend/resume callbacks, but have
 812  * to use notifiers.
 813  */
 814 static int css_power_event(struct notifier_block *this, unsigned long event,
 815                            void *ptr)
 816 {
 817         int ret, i;
 818
 819         switch (event) {
 820         case PM_HIBERNATION_PREPARE:
 821         case PM_SUSPEND_PREPARE:
 822                 ret = NOTIFY_DONE;
 823                 for (i = 0; i <= __MAX_CSSID; i++) {
 824                         struct channel_subsystem *css;
 825
 826                         css = channel_subsystems[i];
 827                         mutex_lock(&css->mutex);
 828                         if (!css->cm_enabled) {
 829                                 mutex_unlock(&css->mutex);
 830                                 continue;
 831                         }
 832                         ret = __chsc_do_secm(css, 0);
 833                         ret = notifier_from_errno(ret);
 834                         mutex_unlock(&css->mutex);
 835                 }
 836                 break;
 837         case PM_POST_HIBERNATION:
 838         case PM_POST_SUSPEND:
 839                 ret = NOTIFY_DONE;
 840                 for (i = 0; i <= __MAX_CSSID; i++) {
 841                         struct channel_subsystem *css;
 842
 843                         css = channel_subsystems[i];
 844                         mutex_lock(&css->mutex);
 845                         if (!css->cm_enabled) {
 846                                 mutex_unlock(&css->mutex);
 847                                 continue;
 848                         }
 849                         ret = __chsc_do_secm(css, 1);
 850                         ret = notifier_from_errno(ret);
 851                         mutex_unlock(&css->mutex);
 852                 }
 853                 /* search for subchannels, which appeared during hibernation */
 854                 css_schedule_reprobe();
 855                 break;
 856         default:
 857                 ret = NOTIFY_DONE;
 858         }
 859         return ret;
 860
 861 }
 862 static struct notifier_block css_power_notifier = {
 863         .notifier_call = css_power_event,
 864 };
 865
 866 /*
 867  * Now that the driver core is running, we can setup our channel subsystem.
 868  * The struct subchannel's are created during probing (except for the
 869  * static console subchannel).
 870  */
 871 static int __init css_bus_init(void)
 872 {
 873         int ret, i;
 874
 875         ret = chsc_init();
 876         if (ret)
 877                 return ret;
 878
 879         chsc_determine_css_characteristics();
 880         /* Try to enable MSS. */
 881         ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
 882         if (ret)
 883                 max_ssid = 0;
 884         else /* Success. */
 885                 max_ssid = __MAX_SSID;
 886
 887         ret = slow_subchannel_init();
 888         if (ret)
 889                 goto out;
 890
 891         ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
 892         if (ret)
 893                 goto out;
 894
 895         if ((ret = bus_register(&css_bus_type)))
 896                 goto out;
 897
 898         /* Setup css structure. */
 899         for (i = 0; i <= __MAX_CSSID; i++) {
 900                 struct channel_subsystem *css;
 901
 902                 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
 903                 if (!css) {
 904                         ret = -ENOMEM;
 905                         goto out_unregister;
 906                 }
 907                 channel_subsystems[i] = css;
 908                 ret = setup_css(i);
 909                 if (ret) {
 910                         kfree(channel_subsystems[i]);
 911                         goto out_unregister;
 912                 }
 913                 ret = device_register(&css->device);
 914                 if (ret) {
 915                         put_device(&css->device);
 916                         goto out_unregister;
 917                 }
 918                 if (css_chsc_characteristics.secm) {
 919                         ret = device_create_file(&css->device,
 920                                                  &dev_attr_cm_enable);
 921                         if (ret)
 922                                 goto out_device;
 923                 }
 924                 ret = device_register(&css->pseudo_subchannel->dev);
 925                 if (ret) {
 926                         put_device(&css->pseudo_subchannel->dev);
 927                         goto out_file;
 928                 }
 929         }
 930         ret = register_reboot_notifier(&css_reboot_notifier);
 931         if (ret)
 932                 goto out_unregister;
 933         ret = register_pm_notifier(&css_power_notifier);
 934         if (ret) {
 935                 unregister_reboot_notifier(&css_reboot_notifier);
 936                 goto out_unregister;
 937         }
 938         css_init_done = 1;
 939
 940         /* Enable default isc for I/O subchannels. */
 941         isc_register(IO_SCH_ISC);
 942
 943         return 0;
 944 out_file:
 945         if (css_chsc_characteristics.secm)
 946                 device_remove_file(&channel_subsystems[i]->device,
 947                                    &dev_attr_cm_enable);
 948 out_device:
 949         device_unregister(&channel_subsystems[i]->device);
 950 out_unregister:
 951         while (i > 0) {
 952                 struct channel_subsystem *css;
 953
 954                 i--;
 955                 css = channel_subsystems[i];
 956                 device_unregister(&css->pseudo_subchannel->dev);
 957                 css->pseudo_subchannel = NULL;
 958                 if (css_chsc_characteristics.secm)
 959                         device_remove_file(&css->device,
 960                                            &dev_attr_cm_enable);
 961                 device_unregister(&css->device);
 962         }
 963         bus_unregister(&css_bus_type);
 964 out:
 965         crw_unregister_handler(CRW_RSC_SCH);
 966         idset_free(slow_subchannel_set);
 967         chsc_init_cleanup();
 968         pr_alert("The CSS device driver initialization failed with "
 969                  "errno=%d\n", ret);
 970         return ret;
 971 }
 972
 973 static void __init css_bus_cleanup(void)
 974 {
 975         struct channel_subsystem *css;
 976         int i;
 977
 978         for (i = 0; i <= __MAX_CSSID; i++) {
 979                 css = channel_subsystems[i];
 980                 device_unregister(&css->pseudo_subchannel->dev);
 981                 css->pseudo_subchannel = NULL;
 982                 if (css_chsc_characteristics.secm)
 983                         device_remove_file(&css->device, &dev_attr_cm_enable);
 984                 device_unregister(&css->device);
 985         }
 986         bus_unregister(&css_bus_type);
 987         crw_unregister_handler(CRW_RSC_SCH);
 988         idset_free(slow_subchannel_set);
 989         chsc_init_cleanup();
 990         isc_unregister(IO_SCH_ISC);
 991 }
 992
 993 static int __init channel_subsystem_init(void)
 994 {
 995         int ret;
 996
 997         ret = css_bus_init();
 998         if (ret)
 999                 return ret;
1000         cio_work_q = create_singlethread_workqueue("cio");
1001         if (!cio_work_q) {
1002                 ret = -ENOMEM;
1003                 goto out_bus;
1004         }
1005         ret = io_subchannel_init();
1006         if (ret)
1007                 goto out_wq;
1008
1009         return ret;
1010 out_wq:
1011         destroy_workqueue(cio_work_q);
1012 out_bus:
1013         css_bus_cleanup();
1014         return ret;
1015 }
1016 subsys_initcall(channel_subsystem_init);
1017
1018 static int css_settle(struct device_driver *drv, void *unused)
1019 {
1020         struct css_driver *cssdrv = to_cssdriver(drv);
1021
1022         if (cssdrv->settle)
1023                 return cssdrv->settle();
1024         return 0;
1025 }
1026
1027 int css_complete_work(void)
1028 {
1029         int ret;
1030
1031         /* Wait for the evaluation of subchannels to finish. */
1032         ret = wait_event_interruptible(css_eval_wq,
1033                                        atomic_read(&css_eval_scheduled) == 0);
1034         if (ret)
1035                 return -EINTR;
1036         flush_workqueue(cio_work_q);
1037         /* Wait for the subchannel type specific initialization to finish */
1038         return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1039 }
1040
1041
1042 /*
1043  * Wait for the initialization of devices to finish, to make sure we are
1044  * done with our setup if the search for the root device starts.
1045  */
1046 static int __init channel_subsystem_init_sync(void)
1047 {
1048         /* Start initial subchannel evaluation. */
1049         css_schedule_eval_all();
1050         css_complete_work();
1051         return 0;
1052 }
1053 subsys_initcall_sync(channel_subsystem_init_sync);
1054
1055 void channel_subsystem_reinit(void)
1056 {
1057         struct channel_path *chp;
1058         struct chp_id chpid;
1059
1060         chsc_enable_facility(CHSC_SDA_OC_MSS);
1061         chp_id_for_each(&chpid) {
1062                 chp = chpid_to_chp(chpid);
1063                 if (!chp)
1064                         continue;
1065                 chsc_determine_base_channel_path_desc(chpid, &chp->desc);
1066         }
1067 }
1068
1069 #ifdef CONFIG_PROC_FS
1070 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1071                                 size_t count, loff_t *ppos)
1072 {
1073         int ret;
1074
1075         /* Handle pending CRW's. */
1076         crw_wait_for_channel_report();
1077         ret = css_complete_work();
1078
1079         return ret ? ret : count;
1080 }
1081
1082 static const struct file_operations cio_settle_proc_fops = {
1083         .open = nonseekable_open,
1084         .write = cio_settle_write,
1085         .llseek = no_llseek,
1086 };
1087
1088 static int __init cio_settle_init(void)
1089 {
1090         struct proc_dir_entry *entry;
1091
1092         entry = proc_create("cio_settle", S_IWUSR, NULL,
1093                             &cio_settle_proc_fops);
1094         if (!entry)
1095                 return -ENOMEM;
1096         return 0;
1097 }
1098 device_initcall(cio_settle_init);
1099 #endif /*CONFIG_PROC_FS*/
1100
1101 int sch_is_pseudo_sch(struct subchannel *sch)
1102 {
1103         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1104 }
1105
1106 static int css_bus_match(struct device *dev, struct device_driver *drv)
1107 {
1108         struct subchannel *sch = to_subchannel(dev);
1109         struct css_driver *driver = to_cssdriver(drv);
1110         struct css_device_id *id;
1111
1112         for (id = driver->subchannel_type; id->match_flags; id++) {
1113                 if (sch->st == id->type)
1114                         return 1;
1115         }
1116
1117         return 0;
1118 }
1119
1120 static int css_probe(struct device *dev)
1121 {
1122         struct subchannel *sch;
1123         int ret;
1124
1125         sch = to_subchannel(dev);
1126         sch->driver = to_cssdriver(dev->driver);
1127         ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1128         if (ret)
1129                 sch->driver = NULL;
1130         return ret;
1131 }
1132
1133 static int css_remove(struct device *dev)
1134 {
1135         struct subchannel *sch;
1136         int ret;
1137
1138         sch = to_subchannel(dev);
1139         ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1140         sch->driver = NULL;
1141         return ret;
1142 }
1143
1144 static void css_shutdown(struct device *dev)
1145 {
1146         struct subchannel *sch;
1147
1148         sch = to_subchannel(dev);
1149         if (sch->driver && sch->driver->shutdown)
1150                 sch->driver->shutdown(sch);
1151 }
1152
1153 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1154 {
1155         struct subchannel *sch = to_subchannel(dev);
1156         int ret;
1157
1158         ret = add_uevent_var(env, "ST=%01X", sch->st);
1159         if (ret)
1160                 return ret;
1161         ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1162         return ret;
1163 }
1164
1165 static int css_pm_prepare(struct device *dev)
1166 {
1167         struct subchannel *sch = to_subchannel(dev);
1168         struct css_driver *drv;
1169
1170         if (mutex_is_locked(&sch->reg_mutex))
1171                 return -EAGAIN;
1172         if (!sch->dev.driver)
1173                 return 0;
1174         drv = to_cssdriver(sch->dev.driver);
1175         /* Notify drivers that they may not register children. */
1176         return drv->prepare ? drv->prepare(sch) : 0;
1177 }
1178
1179 static void css_pm_complete(struct device *dev)
1180 {
1181         struct subchannel *sch = to_subchannel(dev);
1182         struct css_driver *drv;
1183
1184         if (!sch->dev.driver)
1185                 return;
1186         drv = to_cssdriver(sch->dev.driver);
1187         if (drv->complete)
1188                 drv->complete(sch);
1189 }
1190
1191 static int css_pm_freeze(struct device *dev)
1192 {
1193         struct subchannel *sch = to_subchannel(dev);
1194         struct css_driver *drv;
1195
1196         if (!sch->dev.driver)
1197                 return 0;
1198         drv = to_cssdriver(sch->dev.driver);
1199         return drv->freeze ? drv->freeze(sch) : 0;
1200 }
1201
1202 static int css_pm_thaw(struct device *dev)
1203 {
1204         struct subchannel *sch = to_subchannel(dev);
1205         struct css_driver *drv;
1206
1207         if (!sch->dev.driver)
1208                 return 0;
1209         drv = to_cssdriver(sch->dev.driver);
1210         return drv->thaw ? drv->thaw(sch) : 0;
1211 }
1212
1213 static int css_pm_restore(struct device *dev)
1214 {
1215         struct subchannel *sch = to_subchannel(dev);
1216         struct css_driver *drv;
1217
1218         css_update_ssd_info(sch);
1219         if (!sch->dev.driver)
1220                 return 0;
1221         drv = to_cssdriver(sch->dev.driver);
1222         return drv->restore ? drv->restore(sch) : 0;
1223 }
1224
1225 static const struct dev_pm_ops css_pm_ops = {
1226         .prepare = css_pm_prepare,
1227         .complete = css_pm_complete,
1228         .freeze = css_pm_freeze,
1229         .thaw = css_pm_thaw,
1230         .restore = css_pm_restore,
1231 };
1232
1233 static struct bus_type css_bus_type = {
1234         .name     = "css",
1235         .match    = css_bus_match,
1236         .probe    = css_probe,
1237         .remove   = css_remove,
1238         .shutdown = css_shutdown,
1239         .uevent   = css_uevent,
1240         .pm = &css_pm_ops,
1241 };
1242
1243 /**
1244  * css_driver_register - register a css driver
1245  * @cdrv: css driver to register
1246  *
1247  * This is mainly a wrapper around driver_register that sets name
1248  * and bus_type in the embedded struct device_driver correctly.
1249  */
1250 int css_driver_register(struct css_driver *cdrv)
1251 {
1252         cdrv->drv.bus = &css_bus_type;
1253         return driver_register(&cdrv->drv);
1254 }
1255 EXPORT_SYMBOL_GPL(css_driver_register);
1256
1257 /**
1258  * css_driver_unregister - unregister a css driver
1259  * @cdrv: css driver to unregister
1260  *
1261  * This is a wrapper around driver_unregister.
1262  */
1263 void css_driver_unregister(struct css_driver *cdrv)
1264 {
1265         driver_unregister(&cdrv->drv);
1266 }
1267 EXPORT_SYMBOL_GPL(css_driver_unregister);
1268
1269 MODULE_LICENSE("GPL");