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                         idset_sch_del_subseq(slow_subchannel_set, schid);
 550                         break;
 551                 default:
 552                         rc = 0;
 553                 }
 554         }
 555         return rc;
 556 }
 557
 558 static void css_slow_path_func(struct work_struct *unused)
 559 {
 560         unsigned long flags;
 561
 562         CIO_TRACE_EVENT(4, "slowpath");
 563         for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
 564                                    NULL);
 565         spin_lock_irqsave(&slow_subchannel_lock, flags);
 566         if (idset_is_empty(slow_subchannel_set)) {
 567                 atomic_set(&css_eval_scheduled, 0);
 568                 wake_up(&css_eval_wq);
 569         }
 570         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 571 }
 572
 573 static DECLARE_WORK(slow_path_work, css_slow_path_func);
 574 struct workqueue_struct *cio_work_q;
 575
 576 void css_schedule_eval(struct subchannel_id schid)
 577 {
 578         unsigned long flags;
 579
 580         spin_lock_irqsave(&slow_subchannel_lock, flags);
 581         idset_sch_add(slow_subchannel_set, schid);
 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 void css_schedule_eval_all(void)
 588 {
 589         unsigned long flags;
 590
 591         spin_lock_irqsave(&slow_subchannel_lock, flags);
 592         idset_fill(slow_subchannel_set);
 593         atomic_set(&css_eval_scheduled, 1);
 594         queue_work(cio_work_q, &slow_path_work);
 595         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 596 }
 597
 598 static int __unset_registered(struct device *dev, void *data)
 599 {
 600         struct idset *set = data;
 601         struct subchannel *sch = to_subchannel(dev);
 602
 603         idset_sch_del(set, sch->schid);
 604         return 0;
 605 }
 606
 607 static void css_schedule_eval_all_unreg(void)
 608 {
 609         unsigned long flags;
 610         struct idset *unreg_set;
 611
 612         /* Find unregistered subchannels. */
 613         unreg_set = idset_sch_new();
 614         if (!unreg_set) {
 615                 /* Fallback. */
 616                 css_schedule_eval_all();
 617                 return;
 618         }
 619         idset_fill(unreg_set);
 620         bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
 621         /* Apply to slow_subchannel_set. */
 622         spin_lock_irqsave(&slow_subchannel_lock, flags);
 623         idset_add_set(slow_subchannel_set, unreg_set);
 624         atomic_set(&css_eval_scheduled, 1);
 625         queue_work(cio_work_q, &slow_path_work);
 626         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 627         idset_free(unreg_set);
 628 }
 629
 630 void css_wait_for_slow_path(void)
 631 {
 632         flush_workqueue(cio_work_q);
 633 }
 634
 635 /* Schedule reprobing of all unregistered subchannels. */
 636 void css_schedule_reprobe(void)
 637 {
 638         css_schedule_eval_all_unreg();
 639 }
 640 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 641
 642 /*
 643  * Called from the machine check handler for subchannel report words.
 644  */
 645 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 646 {
 647         struct subchannel_id mchk_schid;
 648         struct subchannel *sch;
 649
 650         if (overflow) {
 651                 css_schedule_eval_all();
 652                 return;
 653         }
 654         CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
 655                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 656                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
 657                       crw0->erc, crw0->rsid);
 658         if (crw1)
 659                 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
 660                               "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
 661                               crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
 662                               crw1->anc, crw1->erc, crw1->rsid);
 663         init_subchannel_id(&mchk_schid);
 664         mchk_schid.sch_no = crw0->rsid;
 665         if (crw1)
 666                 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
 667
 668         if (crw0->erc == CRW_ERC_PMOD) {
 669                 sch = get_subchannel_by_schid(mchk_schid);
 670                 if (sch) {
 671                         css_update_ssd_info(sch);
 672                         put_device(&sch->dev);
 673                 }
 674         }
 675         /*
 676          * Since we are always presented with IPI in the CRW, we have to
 677          * use stsch() to find out if the subchannel in question has come
 678          * or gone.
 679          */
 680         css_evaluate_subchannel(mchk_schid, 0);
 681 }
 682
 683 static void __init
 684 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
 685 {
 686         struct cpuid cpu_id;
 687
 688         if (css_general_characteristics.mcss) {
 689                 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
 690                 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
 691         } else {
 692 #ifdef CONFIG_SMP
 693                 css->global_pgid.pgid_high.cpu_addr = stap();
 694 #else
 695                 css->global_pgid.pgid_high.cpu_addr = 0;
 696 #endif
 697         }
 698         get_cpu_id(&cpu_id);
 699         css->global_pgid.cpu_id = cpu_id.ident;
 700         css->global_pgid.cpu_model = cpu_id.machine;
 701         css->global_pgid.tod_high = tod_high;
 702
 703 }
 704
 705 static void
 706 channel_subsystem_release(struct device *dev)
 707 {
 708         struct channel_subsystem *css;
 709
 710         css = to_css(dev);
 711         mutex_destroy(&css->mutex);
 712         if (css->pseudo_subchannel) {
 713                 /* Implies that it has been generated but never registered. */
 714                 css_subchannel_release(&css->pseudo_subchannel->dev);
 715                 css->pseudo_subchannel = NULL;
 716         }
 717         kfree(css);
 718 }
 719
 720 static ssize_t
 721 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
 722                    char *buf)
 723 {
 724         struct channel_subsystem *css = to_css(dev);
 725         int ret;
 726
 727         if (!css)
 728                 return 0;
 729         mutex_lock(&css->mutex);
 730         ret = sprintf(buf, "%x\n", css->cm_enabled);
 731         mutex_unlock(&css->mutex);
 732         return ret;
 733 }
 734
 735 static ssize_t
 736 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
 737                     const char *buf, size_t count)
 738 {
 739         struct channel_subsystem *css = to_css(dev);
 740         int ret;
 741         unsigned long val;
 742
 743         ret = strict_strtoul(buf, 16, &val);
 744         if (ret)
 745                 return ret;
 746         mutex_lock(&css->mutex);
 747         switch (val) {
 748         case 0:
 749                 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
 750                 break;
 751         case 1:
 752                 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
 753                 break;
 754         default:
 755                 ret = -EINVAL;
 756         }
 757         mutex_unlock(&css->mutex);
 758         return ret < 0 ? ret : count;
 759 }
 760
 761 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
 762
 763 static int __init setup_css(int nr)
 764 {
 765         u32 tod_high;
 766         int ret;
 767         struct channel_subsystem *css;
 768
 769         css = channel_subsystems[nr];
 770         memset(css, 0, sizeof(struct channel_subsystem));
 771         css->pseudo_subchannel =
 772                 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
 773         if (!css->pseudo_subchannel)
 774                 return -ENOMEM;
 775         css->pseudo_subchannel->dev.parent = &css->device;
 776         css->pseudo_subchannel->dev.release = css_subchannel_release;
 777         dev_set_name(&css->pseudo_subchannel->dev, "defunct");
 778         mutex_init(&css->pseudo_subchannel->reg_mutex);
 779         ret = css_sch_create_locks(css->pseudo_subchannel);
 780         if (ret) {
 781                 kfree(css->pseudo_subchannel);
 782                 return ret;
 783         }
 784         mutex_init(&css->mutex);
 785         css->valid = 1;
 786         css->cssid = nr;
 787         dev_set_name(&css->device, "css%x", nr);
 788         css->device.release = channel_subsystem_release;
 789         tod_high = (u32) (get_tod_clock() >> 32);
 790         css_generate_pgid(css, tod_high);
 791         return 0;
 792 }
 793
 794 static int css_reboot_event(struct notifier_block *this,
 795                             unsigned long event,
 796                             void *ptr)
 797 {
 798         int ret, i;
 799
 800         ret = NOTIFY_DONE;
 801         for (i = 0; i <= __MAX_CSSID; i++) {
 802                 struct channel_subsystem *css;
 803
 804                 css = channel_subsystems[i];
 805                 mutex_lock(&css->mutex);
 806                 if (css->cm_enabled)
 807                         if (chsc_secm(css, 0))
 808                                 ret = NOTIFY_BAD;
 809                 mutex_unlock(&css->mutex);
 810         }
 811
 812         return ret;
 813 }
 814
 815 static struct notifier_block css_reboot_notifier = {
 816         .notifier_call = css_reboot_event,
 817 };
 818
 819 /*
 820  * Since the css devices are neither on a bus nor have a class
 821  * nor have a special device type, we cannot stop/restart channel
 822  * path measurements via the normal suspend/resume callbacks, but have
 823  * to use notifiers.
 824  */
 825 static int css_power_event(struct notifier_block *this, unsigned long event,
 826                            void *ptr)
 827 {
 828         int ret, i;
 829
 830         switch (event) {
 831         case PM_HIBERNATION_PREPARE:
 832         case PM_SUSPEND_PREPARE:
 833                 ret = NOTIFY_DONE;
 834                 for (i = 0; i <= __MAX_CSSID; i++) {
 835                         struct channel_subsystem *css;
 836
 837                         css = channel_subsystems[i];
 838                         mutex_lock(&css->mutex);
 839                         if (!css->cm_enabled) {
 840                                 mutex_unlock(&css->mutex);
 841                                 continue;
 842                         }
 843                         ret = __chsc_do_secm(css, 0);
 844                         ret = notifier_from_errno(ret);
 845                         mutex_unlock(&css->mutex);
 846                 }
 847                 break;
 848         case PM_POST_HIBERNATION:
 849         case PM_POST_SUSPEND:
 850                 ret = NOTIFY_DONE;
 851                 for (i = 0; i <= __MAX_CSSID; i++) {
 852                         struct channel_subsystem *css;
 853
 854                         css = channel_subsystems[i];
 855                         mutex_lock(&css->mutex);
 856                         if (!css->cm_enabled) {
 857                                 mutex_unlock(&css->mutex);
 858                                 continue;
 859                         }
 860                         ret = __chsc_do_secm(css, 1);
 861                         ret = notifier_from_errno(ret);
 862                         mutex_unlock(&css->mutex);
 863                 }
 864                 /* search for subchannels, which appeared during hibernation */
 865                 css_schedule_reprobe();
 866                 break;
 867         default:
 868                 ret = NOTIFY_DONE;
 869         }
 870         return ret;
 871
 872 }
 873 static struct notifier_block css_power_notifier = {
 874         .notifier_call = css_power_event,
 875 };
 876
 877 /*
 878  * Now that the driver core is running, we can setup our channel subsystem.
 879  * The struct subchannel's are created during probing.
 880  */
 881 static int __init css_bus_init(void)
 882 {
 883         int ret, i;
 884
 885         ret = chsc_init();
 886         if (ret)
 887                 return ret;
 888
 889         chsc_determine_css_characteristics();
 890         /* Try to enable MSS. */
 891         ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
 892         if (ret)
 893                 max_ssid = 0;
 894         else /* Success. */
 895                 max_ssid = __MAX_SSID;
 896
 897         ret = slow_subchannel_init();
 898         if (ret)
 899                 goto out;
 900
 901         ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
 902         if (ret)
 903                 goto out;
 904
 905         if ((ret = bus_register(&css_bus_type)))
 906                 goto out;
 907
 908         /* Setup css structure. */
 909         for (i = 0; i <= __MAX_CSSID; i++) {
 910                 struct channel_subsystem *css;
 911
 912                 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
 913                 if (!css) {
 914                         ret = -ENOMEM;
 915                         goto out_unregister;
 916                 }
 917                 channel_subsystems[i] = css;
 918                 ret = setup_css(i);
 919                 if (ret) {
 920                         kfree(channel_subsystems[i]);
 921                         goto out_unregister;
 922                 }
 923                 ret = device_register(&css->device);
 924                 if (ret) {
 925                         put_device(&css->device);
 926                         goto out_unregister;
 927                 }
 928                 if (css_chsc_characteristics.secm) {
 929                         ret = device_create_file(&css->device,
 930                                                  &dev_attr_cm_enable);
 931                         if (ret)
 932                                 goto out_device;
 933                 }
 934                 ret = device_register(&css->pseudo_subchannel->dev);
 935                 if (ret) {
 936                         put_device(&css->pseudo_subchannel->dev);
 937                         goto out_file;
 938                 }
 939         }
 940         ret = register_reboot_notifier(&css_reboot_notifier);
 941         if (ret)
 942                 goto out_unregister;
 943         ret = register_pm_notifier(&css_power_notifier);
 944         if (ret) {
 945                 unregister_reboot_notifier(&css_reboot_notifier);
 946                 goto out_unregister;
 947         }
 948         css_init_done = 1;
 949
 950         /* Enable default isc for I/O subchannels. */
 951         isc_register(IO_SCH_ISC);
 952
 953         return 0;
 954 out_file:
 955         if (css_chsc_characteristics.secm)
 956                 device_remove_file(&channel_subsystems[i]->device,
 957                                    &dev_attr_cm_enable);
 958 out_device:
 959         device_unregister(&channel_subsystems[i]->device);
 960 out_unregister:
 961         while (i > 0) {
 962                 struct channel_subsystem *css;
 963
 964                 i--;
 965                 css = channel_subsystems[i];
 966                 device_unregister(&css->pseudo_subchannel->dev);
 967                 css->pseudo_subchannel = NULL;
 968                 if (css_chsc_characteristics.secm)
 969                         device_remove_file(&css->device,
 970                                            &dev_attr_cm_enable);
 971                 device_unregister(&css->device);
 972         }
 973         bus_unregister(&css_bus_type);
 974 out:
 975         crw_unregister_handler(CRW_RSC_SCH);
 976         idset_free(slow_subchannel_set);
 977         chsc_init_cleanup();
 978         pr_alert("The CSS device driver initialization failed with "
 979                  "errno=%d\n", ret);
 980         return ret;
 981 }
 982
 983 static void __init css_bus_cleanup(void)
 984 {
 985         struct channel_subsystem *css;
 986         int i;
 987
 988         for (i = 0; i <= __MAX_CSSID; i++) {
 989                 css = channel_subsystems[i];
 990                 device_unregister(&css->pseudo_subchannel->dev);
 991                 css->pseudo_subchannel = NULL;
 992                 if (css_chsc_characteristics.secm)
 993                         device_remove_file(&css->device, &dev_attr_cm_enable);
 994                 device_unregister(&css->device);
 995         }
 996         bus_unregister(&css_bus_type);
 997         crw_unregister_handler(CRW_RSC_SCH);
 998         idset_free(slow_subchannel_set);
 999         chsc_init_cleanup();
1000         isc_unregister(IO_SCH_ISC);
1001 }
1002
1003 static int __init channel_subsystem_init(void)
1004 {
1005         int ret;
1006
1007         ret = css_bus_init();
1008         if (ret)
1009                 return ret;
1010         cio_work_q = create_singlethread_workqueue("cio");
1011         if (!cio_work_q) {
1012                 ret = -ENOMEM;
1013                 goto out_bus;
1014         }
1015         ret = io_subchannel_init();
1016         if (ret)
1017                 goto out_wq;
1018
1019         return ret;
1020 out_wq:
1021         destroy_workqueue(cio_work_q);
1022 out_bus:
1023         css_bus_cleanup();
1024         return ret;
1025 }
1026 subsys_initcall(channel_subsystem_init);
1027
1028 static int css_settle(struct device_driver *drv, void *unused)
1029 {
1030         struct css_driver *cssdrv = to_cssdriver(drv);
1031
1032         if (cssdrv->settle)
1033                 return cssdrv->settle();
1034         return 0;
1035 }
1036
1037 int css_complete_work(void)
1038 {
1039         int ret;
1040
1041         /* Wait for the evaluation of subchannels to finish. */
1042         ret = wait_event_interruptible(css_eval_wq,
1043                                        atomic_read(&css_eval_scheduled) == 0);
1044         if (ret)
1045                 return -EINTR;
1046         flush_workqueue(cio_work_q);
1047         /* Wait for the subchannel type specific initialization to finish */
1048         return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1049 }
1050
1051
1052 /*
1053  * Wait for the initialization of devices to finish, to make sure we are
1054  * done with our setup if the search for the root device starts.
1055  */
1056 static int __init channel_subsystem_init_sync(void)
1057 {
1058         /* Register subchannels which are already in use. */
1059         cio_register_early_subchannels();
1060         /* Start initial subchannel evaluation. */
1061         css_schedule_eval_all();
1062         css_complete_work();
1063         return 0;
1064 }
1065 subsys_initcall_sync(channel_subsystem_init_sync);
1066
1067 void channel_subsystem_reinit(void)
1068 {
1069         struct channel_path *chp;
1070         struct chp_id chpid;
1071
1072         chsc_enable_facility(CHSC_SDA_OC_MSS);
1073         chp_id_for_each(&chpid) {
1074                 chp = chpid_to_chp(chpid);
1075                 if (chp)
1076                         chp_update_desc(chp);
1077         }
1078 }
1079
1080 #ifdef CONFIG_PROC_FS
1081 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1082                                 size_t count, loff_t *ppos)
1083 {
1084         int ret;
1085
1086         /* Handle pending CRW's. */
1087         crw_wait_for_channel_report();
1088         ret = css_complete_work();
1089
1090         return ret ? ret : count;
1091 }
1092
1093 static const struct file_operations cio_settle_proc_fops = {
1094         .open = nonseekable_open,
1095         .write = cio_settle_write,
1096         .llseek = no_llseek,
1097 };
1098
1099 static int __init cio_settle_init(void)
1100 {
1101         struct proc_dir_entry *entry;
1102
1103         entry = proc_create("cio_settle", S_IWUSR, NULL,
1104                             &cio_settle_proc_fops);
1105         if (!entry)
1106                 return -ENOMEM;
1107         return 0;
1108 }
1109 device_initcall(cio_settle_init);
1110 #endif /*CONFIG_PROC_FS*/
1111
1112 int sch_is_pseudo_sch(struct subchannel *sch)
1113 {
1114         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1115 }
1116
1117 static int css_bus_match(struct device *dev, struct device_driver *drv)
1118 {
1119         struct subchannel *sch = to_subchannel(dev);
1120         struct css_driver *driver = to_cssdriver(drv);
1121         struct css_device_id *id;
1122
1123         for (id = driver->subchannel_type; id->match_flags; id++) {
1124                 if (sch->st == id->type)
1125                         return 1;
1126         }
1127
1128         return 0;
1129 }
1130
1131 static int css_probe(struct device *dev)
1132 {
1133         struct subchannel *sch;
1134         int ret;
1135
1136         sch = to_subchannel(dev);
1137         sch->driver = to_cssdriver(dev->driver);
1138         ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1139         if (ret)
1140                 sch->driver = NULL;
1141         return ret;
1142 }
1143
1144 static int css_remove(struct device *dev)
1145 {
1146         struct subchannel *sch;
1147         int ret;
1148
1149         sch = to_subchannel(dev);
1150         ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1151         sch->driver = NULL;
1152         return ret;
1153 }
1154
1155 static void css_shutdown(struct device *dev)
1156 {
1157         struct subchannel *sch;
1158
1159         sch = to_subchannel(dev);
1160         if (sch->driver && sch->driver->shutdown)
1161                 sch->driver->shutdown(sch);
1162 }
1163
1164 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1165 {
1166         struct subchannel *sch = to_subchannel(dev);
1167         int ret;
1168
1169         ret = add_uevent_var(env, "ST=%01X", sch->st);
1170         if (ret)
1171                 return ret;
1172         ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1173         return ret;
1174 }
1175
1176 static int css_pm_prepare(struct device *dev)
1177 {
1178         struct subchannel *sch = to_subchannel(dev);
1179         struct css_driver *drv;
1180
1181         if (mutex_is_locked(&sch->reg_mutex))
1182                 return -EAGAIN;
1183         if (!sch->dev.driver)
1184                 return 0;
1185         drv = to_cssdriver(sch->dev.driver);
1186         /* Notify drivers that they may not register children. */
1187         return drv->prepare ? drv->prepare(sch) : 0;
1188 }
1189
1190 static void css_pm_complete(struct device *dev)
1191 {
1192         struct subchannel *sch = to_subchannel(dev);
1193         struct css_driver *drv;
1194
1195         if (!sch->dev.driver)
1196                 return;
1197         drv = to_cssdriver(sch->dev.driver);
1198         if (drv->complete)
1199                 drv->complete(sch);
1200 }
1201
1202 static int css_pm_freeze(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->freeze ? drv->freeze(sch) : 0;
1211 }
1212
1213 static int css_pm_thaw(struct device *dev)
1214 {
1215         struct subchannel *sch = to_subchannel(dev);
1216         struct css_driver *drv;
1217
1218         if (!sch->dev.driver)
1219                 return 0;
1220         drv = to_cssdriver(sch->dev.driver);
1221         return drv->thaw ? drv->thaw(sch) : 0;
1222 }
1223
1224 static int css_pm_restore(struct device *dev)
1225 {
1226         struct subchannel *sch = to_subchannel(dev);
1227         struct css_driver *drv;
1228
1229         css_update_ssd_info(sch);
1230         if (!sch->dev.driver)
1231                 return 0;
1232         drv = to_cssdriver(sch->dev.driver);
1233         return drv->restore ? drv->restore(sch) : 0;
1234 }
1235
1236 static const struct dev_pm_ops css_pm_ops = {
1237         .prepare = css_pm_prepare,
1238         .complete = css_pm_complete,
1239         .freeze = css_pm_freeze,
1240         .thaw = css_pm_thaw,
1241         .restore = css_pm_restore,
1242 };
1243
1244 static struct bus_type css_bus_type = {
1245         .name     = "css",
1246         .match    = css_bus_match,
1247         .probe    = css_probe,
1248         .remove   = css_remove,
1249         .shutdown = css_shutdown,
1250         .uevent   = css_uevent,
1251         .pm = &css_pm_ops,
1252 };
1253
1254 /**
1255  * css_driver_register - register a css driver
1256  * @cdrv: css driver to register
1257  *
1258  * This is mainly a wrapper around driver_register that sets name
1259  * and bus_type in the embedded struct device_driver correctly.
1260  */
1261 int css_driver_register(struct css_driver *cdrv)
1262 {
1263         cdrv->drv.bus = &css_bus_type;
1264         return driver_register(&cdrv->drv);
1265 }
1266 EXPORT_SYMBOL_GPL(css_driver_register);
1267
1268 /**
1269  * css_driver_unregister - unregister a css driver
1270  * @cdrv: css driver to unregister
1271  *
1272  * This is a wrapper around driver_unregister.
1273  */
1274 void css_driver_unregister(struct css_driver *cdrv)
1275 {
1276         driver_unregister(&cdrv->drv);
1277 }
1278 EXPORT_SYMBOL_GPL(css_driver_unregister);
1279
1280 MODULE_LICENSE("GPL");