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