drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002,2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/errno.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include <linux/list.h>
  21 #include <linux/device.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/timer.h>
  24
  25 #include <asm/ccwdev.h>
  26 #include <asm/cio.h>
  27 #include <asm/param.h>          /* HZ */
  28 #include <asm/cmb.h>
  29 #include <asm/isc.h>
  30
  31 #include "chp.h"
  32 #include "cio.h"
  33 #include "cio_debug.h"
  34 #include "css.h"
  35 #include "device.h"
  36 #include "ioasm.h"
  37 #include "io_sch.h"
  38 #include "blacklist.h"
  39 #include "chsc.h"
  40
  41 static struct timer_list recovery_timer;
  42 static DEFINE_SPINLOCK(recovery_lock);
  43 static int recovery_phase;
  44 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  45
  46 /******************* bus type handling ***********************/
  47
  48 /* The Linux driver model distinguishes between a bus type and
  49  * the bus itself. Of course we only have one channel
  50  * subsystem driver and one channel system per machine, but
  51  * we still use the abstraction. T.R. says it's a good idea. */
  52 static int
  53 ccw_bus_match (struct device * dev, struct device_driver * drv)
  54 {
  55         struct ccw_device *cdev = to_ccwdev(dev);
  56         struct ccw_driver *cdrv = to_ccwdrv(drv);
  57         const struct ccw_device_id *ids = cdrv->ids, *found;
  58
  59         if (!ids)
  60                 return 0;
  61
  62         found = ccw_device_id_match(ids, &cdev->id);
  63         if (!found)
  64                 return 0;
  65
  66         cdev->id.driver_info = found->driver_info;
  67
  68         return 1;
  69 }
  70
  71 /* Store modalias string delimited by prefix/suffix string into buffer with
  72  * specified size. Return length of resulting string (excluding trailing '\0')
  73  * even if string doesn't fit buffer (snprintf semantics). */
  74 static int snprint_alias(char *buf, size_t size,
  75                          struct ccw_device_id *id, const char *suffix)
  76 {
  77         int len;
  78
  79         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  80         if (len > size)
  81                 return len;
  82         buf += len;
  83         size -= len;
  84
  85         if (id->dev_type != 0)
  86                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  87                                 id->dev_model, suffix);
  88         else
  89                 len += snprintf(buf, size, "dtdm%s", suffix);
  90
  91         return len;
  92 }
  93
  94 /* Set up environment variables for ccw device uevent. Return 0 on success,
  95  * non-zero otherwise. */
  96 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  97 {
  98         struct ccw_device *cdev = to_ccwdev(dev);
  99         struct ccw_device_id *id = &(cdev->id);
 100         int ret;
 101         char modalias_buf[30];
 102
 103         /* CU_TYPE= */
 104         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 105         if (ret)
 106                 return ret;
 107
 108         /* CU_MODEL= */
 109         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 110         if (ret)
 111                 return ret;
 112
 113         /* The next two can be zero, that's ok for us */
 114         /* DEV_TYPE= */
 115         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 116         if (ret)
 117                 return ret;
 118
 119         /* DEV_MODEL= */
 120         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 121         if (ret)
 122                 return ret;
 123
 124         /* MODALIAS=  */
 125         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 126         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 127         return ret;
 128 }
 129
 130 struct bus_type ccw_bus_type;
 131
 132 static void io_subchannel_irq(struct subchannel *);
 133 static int io_subchannel_probe(struct subchannel *);
 134 static int io_subchannel_remove(struct subchannel *);
 135 static void io_subchannel_shutdown(struct subchannel *);
 136 static int io_subchannel_sch_event(struct subchannel *, int);
 137 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 138                                    int);
 139 static void recovery_func(unsigned long data);
 140 wait_queue_head_t ccw_device_init_wq;
 141 atomic_t ccw_device_init_count;
 142
 143 static struct css_device_id io_subchannel_ids[] = {
 144         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 145         { /* end of list */ },
 146 };
 147 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 148
 149 static int io_subchannel_prepare(struct subchannel *sch)
 150 {
 151         struct ccw_device *cdev;
 152         /*
 153          * Don't allow suspend while a ccw device registration
 154          * is still outstanding.
 155          */
 156         cdev = sch_get_cdev(sch);
 157         if (cdev && !device_is_registered(&cdev->dev))
 158                 return -EAGAIN;
 159         return 0;
 160 }
 161
 162 static int io_subchannel_settle(void)
 163 {
 164         int ret;
 165
 166         ret = wait_event_interruptible(ccw_device_init_wq,
 167                                 atomic_read(&ccw_device_init_count) == 0);
 168         if (ret)
 169                 return -EINTR;
 170         flush_workqueue(cio_work_q);
 171         return 0;
 172 }
 173
 174 static struct css_driver io_subchannel_driver = {
 175         .owner = THIS_MODULE,
 176         .subchannel_type = io_subchannel_ids,
 177         .name = "io_subchannel",
 178         .irq = io_subchannel_irq,
 179         .sch_event = io_subchannel_sch_event,
 180         .chp_event = io_subchannel_chp_event,
 181         .probe = io_subchannel_probe,
 182         .remove = io_subchannel_remove,
 183         .shutdown = io_subchannel_shutdown,
 184         .prepare = io_subchannel_prepare,
 185         .settle = io_subchannel_settle,
 186 };
 187
 188 int __init io_subchannel_init(void)
 189 {
 190         int ret;
 191
 192         init_waitqueue_head(&ccw_device_init_wq);
 193         atomic_set(&ccw_device_init_count, 0);
 194         setup_timer(&recovery_timer, recovery_func, 0);
 195
 196         ret = bus_register(&ccw_bus_type);
 197         if (ret)
 198                 return ret;
 199         ret = css_driver_register(&io_subchannel_driver);
 200         if (ret)
 201                 bus_unregister(&ccw_bus_type);
 202
 203         return ret;
 204 }
 205
 206
 207 /************************ device handling **************************/
 208
 209 /*
 210  * A ccw_device has some interfaces in sysfs in addition to the
 211  * standard ones.
 212  * The following entries are designed to export the information which
 213  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 214  * are obvious, so they don't have an entry :)
 215  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 216  */
 217 static ssize_t
 218 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 219 {
 220         struct subchannel *sch = to_subchannel(dev);
 221         struct chsc_ssd_info *ssd = &sch->ssd_info;
 222         ssize_t ret = 0;
 223         int chp;
 224         int mask;
 225
 226         for (chp = 0; chp < 8; chp++) {
 227                 mask = 0x80 >> chp;
 228                 if (ssd->path_mask & mask)
 229                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 230                 else
 231                         ret += sprintf(buf + ret, "00 ");
 232         }
 233         ret += sprintf (buf+ret, "\n");
 234         return min((ssize_t)PAGE_SIZE, ret);
 235 }
 236
 237 static ssize_t
 238 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 239 {
 240         struct subchannel *sch = to_subchannel(dev);
 241         struct pmcw *pmcw = &sch->schib.pmcw;
 242
 243         return sprintf (buf, "%02x %02x %02x\n",
 244                         pmcw->pim, pmcw->pam, pmcw->pom);
 245 }
 246
 247 static ssize_t
 248 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 249 {
 250         struct ccw_device *cdev = to_ccwdev(dev);
 251         struct ccw_device_id *id = &(cdev->id);
 252
 253         if (id->dev_type != 0)
 254                 return sprintf(buf, "%04x/%02x\n",
 255                                 id->dev_type, id->dev_model);
 256         else
 257                 return sprintf(buf, "n/a\n");
 258 }
 259
 260 static ssize_t
 261 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 262 {
 263         struct ccw_device *cdev = to_ccwdev(dev);
 264         struct ccw_device_id *id = &(cdev->id);
 265
 266         return sprintf(buf, "%04x/%02x\n",
 267                        id->cu_type, id->cu_model);
 268 }
 269
 270 static ssize_t
 271 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 272 {
 273         struct ccw_device *cdev = to_ccwdev(dev);
 274         struct ccw_device_id *id = &(cdev->id);
 275         int len;
 276
 277         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 278
 279         return len > PAGE_SIZE ? PAGE_SIZE : len;
 280 }
 281
 282 static ssize_t
 283 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 284 {
 285         struct ccw_device *cdev = to_ccwdev(dev);
 286
 287         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 288 }
 289
 290 int ccw_device_is_orphan(struct ccw_device *cdev)
 291 {
 292         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 293 }
 294
 295 static void ccw_device_unregister(struct ccw_device *cdev)
 296 {
 297         if (device_is_registered(&cdev->dev)) {
 298                 /* Undo device_add(). */
 299                 device_del(&cdev->dev);
 300         }
 301         if (cdev->private->flags.initialized) {
 302                 cdev->private->flags.initialized = 0;
 303                 /* Release reference from device_initialize(). */
 304                 put_device(&cdev->dev);
 305         }
 306 }
 307
 308 static void io_subchannel_quiesce(struct subchannel *);
 309
 310 /**
 311  * ccw_device_set_offline() - disable a ccw device for I/O
 312  * @cdev: target ccw device
 313  *
 314  * This function calls the driver's set_offline() function for @cdev, if
 315  * given, and then disables @cdev.
 316  * Returns:
 317  *   %0 on success and a negative error value on failure.
 318  * Context:
 319  *  enabled, ccw device lock not held
 320  */
 321 int ccw_device_set_offline(struct ccw_device *cdev)
 322 {
 323         struct subchannel *sch;
 324         int ret, state;
 325
 326         if (!cdev)
 327                 return -ENODEV;
 328         if (!cdev->online || !cdev->drv)
 329                 return -EINVAL;
 330
 331         if (cdev->drv->set_offline) {
 332                 ret = cdev->drv->set_offline(cdev);
 333                 if (ret != 0)
 334                         return ret;
 335         }
 336         cdev->online = 0;
 337         spin_lock_irq(cdev->ccwlock);
 338         sch = to_subchannel(cdev->dev.parent);
 339         /* Wait until a final state or DISCONNECTED is reached */
 340         while (!dev_fsm_final_state(cdev) &&
 341                cdev->private->state != DEV_STATE_DISCONNECTED) {
 342                 spin_unlock_irq(cdev->ccwlock);
 343                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 344                            cdev->private->state == DEV_STATE_DISCONNECTED));
 345                 spin_lock_irq(cdev->ccwlock);
 346         }
 347         do {
 348                 ret = ccw_device_offline(cdev);
 349                 if (!ret)
 350                         break;
 351                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 352                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 353                               cdev->private->dev_id.devno);
 354                 if (ret != -EBUSY)
 355                         goto error;
 356                 state = cdev->private->state;
 357                 spin_unlock_irq(cdev->ccwlock);
 358                 io_subchannel_quiesce(sch);
 359                 spin_lock_irq(cdev->ccwlock);
 360                 cdev->private->state = state;
 361         } while (ret == -EBUSY);
 362         spin_unlock_irq(cdev->ccwlock);
 363         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 364                    cdev->private->state == DEV_STATE_DISCONNECTED));
 365         /* Inform the user if set offline failed. */
 366         if (cdev->private->state == DEV_STATE_BOXED) {
 367                 pr_warning("%s: The device entered boxed state while "
 368                            "being set offline\n", dev_name(&cdev->dev));
 369         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 370                 pr_warning("%s: The device stopped operating while "
 371                            "being set offline\n", dev_name(&cdev->dev));
 372         }
 373         /* Give up reference from ccw_device_set_online(). */
 374         put_device(&cdev->dev);
 375         return 0;
 376
 377 error:
 378         cdev->private->state = DEV_STATE_OFFLINE;
 379         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 380         spin_unlock_irq(cdev->ccwlock);
 381         /* Give up reference from ccw_device_set_online(). */
 382         put_device(&cdev->dev);
 383         return -ENODEV;
 384 }
 385
 386 /**
 387  * ccw_device_set_online() - enable a ccw device for I/O
 388  * @cdev: target ccw device
 389  *
 390  * This function first enables @cdev and then calls the driver's set_online()
 391  * function for @cdev, if given. If set_online() returns an error, @cdev is
 392  * disabled again.
 393  * Returns:
 394  *   %0 on success and a negative error value on failure.
 395  * Context:
 396  *  enabled, ccw device lock not held
 397  */
 398 int ccw_device_set_online(struct ccw_device *cdev)
 399 {
 400         int ret;
 401         int ret2;
 402
 403         if (!cdev)
 404                 return -ENODEV;
 405         if (cdev->online || !cdev->drv)
 406                 return -EINVAL;
 407         /* Hold on to an extra reference while device is online. */
 408         if (!get_device(&cdev->dev))
 409                 return -ENODEV;
 410
 411         spin_lock_irq(cdev->ccwlock);
 412         ret = ccw_device_online(cdev);
 413         spin_unlock_irq(cdev->ccwlock);
 414         if (ret == 0)
 415                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 416         else {
 417                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 418                               "device 0.%x.%04x\n",
 419                               ret, cdev->private->dev_id.ssid,
 420                               cdev->private->dev_id.devno);
 421                 /* Give up online reference since onlining failed. */
 422                 put_device(&cdev->dev);
 423                 return ret;
 424         }
 425         spin_lock_irq(cdev->ccwlock);
 426         /* Check if online processing was successful */
 427         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 428             (cdev->private->state != DEV_STATE_W4SENSE)) {
 429                 spin_unlock_irq(cdev->ccwlock);
 430                 /* Inform the user that set online failed. */
 431                 if (cdev->private->state == DEV_STATE_BOXED) {
 432                         pr_warning("%s: Setting the device online failed "
 433                                    "because it is boxed\n",
 434                                    dev_name(&cdev->dev));
 435                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 436                         pr_warning("%s: Setting the device online failed "
 437                                    "because it is not operational\n",
 438                                    dev_name(&cdev->dev));
 439                 }
 440                 /* Give up online reference since onlining failed. */
 441                 put_device(&cdev->dev);
 442                 return -ENODEV;
 443         }
 444         spin_unlock_irq(cdev->ccwlock);
 445         if (cdev->drv->set_online)
 446                 ret = cdev->drv->set_online(cdev);
 447         if (ret)
 448                 goto rollback;
 449         cdev->online = 1;
 450         return 0;
 451
 452 rollback:
 453         spin_lock_irq(cdev->ccwlock);
 454         /* Wait until a final state or DISCONNECTED is reached */
 455         while (!dev_fsm_final_state(cdev) &&
 456                cdev->private->state != DEV_STATE_DISCONNECTED) {
 457                 spin_unlock_irq(cdev->ccwlock);
 458                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 459                            cdev->private->state == DEV_STATE_DISCONNECTED));
 460                 spin_lock_irq(cdev->ccwlock);
 461         }
 462         ret2 = ccw_device_offline(cdev);
 463         if (ret2)
 464                 goto error;
 465         spin_unlock_irq(cdev->ccwlock);
 466         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 467                    cdev->private->state == DEV_STATE_DISCONNECTED));
 468         /* Give up online reference since onlining failed. */
 469         put_device(&cdev->dev);
 470         return ret;
 471
 472 error:
 473         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 474                       "device 0.%x.%04x\n",
 475                       ret2, cdev->private->dev_id.ssid,
 476                       cdev->private->dev_id.devno);
 477         cdev->private->state = DEV_STATE_OFFLINE;
 478         spin_unlock_irq(cdev->ccwlock);
 479         /* Give up online reference since onlining failed. */
 480         put_device(&cdev->dev);
 481         return ret;
 482 }
 483
 484 static int online_store_handle_offline(struct ccw_device *cdev)
 485 {
 486         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 487                 spin_lock_irq(cdev->ccwlock);
 488                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 489                 spin_unlock_irq(cdev->ccwlock);
 490                 return 0;
 491         }
 492         if (cdev->drv && cdev->drv->set_offline)
 493                 return ccw_device_set_offline(cdev);
 494         return -EINVAL;
 495 }
 496
 497 static int online_store_recog_and_online(struct ccw_device *cdev)
 498 {
 499         /* Do device recognition, if needed. */
 500         if (cdev->private->state == DEV_STATE_BOXED) {
 501                 spin_lock_irq(cdev->ccwlock);
 502                 ccw_device_recognition(cdev);
 503                 spin_unlock_irq(cdev->ccwlock);
 504                 wait_event(cdev->private->wait_q,
 505                            cdev->private->flags.recog_done);
 506                 if (cdev->private->state != DEV_STATE_OFFLINE)
 507                         /* recognition failed */
 508                         return -EAGAIN;
 509         }
 510         if (cdev->drv && cdev->drv->set_online)
 511                 return ccw_device_set_online(cdev);
 512         return -EINVAL;
 513 }
 514
 515 static int online_store_handle_online(struct ccw_device *cdev, int force)
 516 {
 517         int ret;
 518
 519         ret = online_store_recog_and_online(cdev);
 520         if (ret && !force)
 521                 return ret;
 522         if (force && cdev->private->state == DEV_STATE_BOXED) {
 523                 ret = ccw_device_stlck(cdev);
 524                 if (ret)
 525                         return ret;
 526                 if (cdev->id.cu_type == 0)
 527                         cdev->private->state = DEV_STATE_NOT_OPER;
 528                 ret = online_store_recog_and_online(cdev);
 529                 if (ret)
 530                         return ret;
 531         }
 532         return 0;
 533 }
 534
 535 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 536                              const char *buf, size_t count)
 537 {
 538         struct ccw_device *cdev = to_ccwdev(dev);
 539         int force, ret;
 540         unsigned long i;
 541
 542         if (!dev_fsm_final_state(cdev) &&
 543             cdev->private->state != DEV_STATE_DISCONNECTED)
 544                 return -EAGAIN;
 545         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 546                 return -EAGAIN;
 547
 548         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 549                 atomic_set(&cdev->private->onoff, 0);
 550                 return -EINVAL;
 551         }
 552         if (!strncmp(buf, "force\n", count)) {
 553                 force = 1;
 554                 i = 1;
 555                 ret = 0;
 556         } else {
 557                 force = 0;
 558                 ret = strict_strtoul(buf, 16, &i);
 559         }
 560         if (ret)
 561                 goto out;
 562         switch (i) {
 563         case 0:
 564                 ret = online_store_handle_offline(cdev);
 565                 break;
 566         case 1:
 567                 ret = online_store_handle_online(cdev, force);
 568                 break;
 569         default:
 570                 ret = -EINVAL;
 571         }
 572 out:
 573         if (cdev->drv)
 574                 module_put(cdev->drv->owner);
 575         atomic_set(&cdev->private->onoff, 0);
 576         return (ret < 0) ? ret : count;
 577 }
 578
 579 static ssize_t
 580 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 581 {
 582         struct ccw_device *cdev = to_ccwdev(dev);
 583         struct subchannel *sch;
 584
 585         if (ccw_device_is_orphan(cdev))
 586                 return sprintf(buf, "no device\n");
 587         switch (cdev->private->state) {
 588         case DEV_STATE_BOXED:
 589                 return sprintf(buf, "boxed\n");
 590         case DEV_STATE_DISCONNECTED:
 591         case DEV_STATE_DISCONNECTED_SENSE_ID:
 592         case DEV_STATE_NOT_OPER:
 593                 sch = to_subchannel(dev->parent);
 594                 if (!sch->lpm)
 595                         return sprintf(buf, "no path\n");
 596                 else
 597                         return sprintf(buf, "no device\n");
 598         default:
 599                 /* All other states considered fine. */
 600                 return sprintf(buf, "good\n");
 601         }
 602 }
 603
 604 static ssize_t
 605 initiate_logging(struct device *dev, struct device_attribute *attr,
 606                  const char *buf, size_t count)
 607 {
 608         struct subchannel *sch = to_subchannel(dev);
 609         int rc;
 610
 611         rc = chsc_siosl(sch->schid);
 612         if (rc < 0) {
 613                 pr_warning("Logging for subchannel 0.%x.%04x failed with "
 614                            "errno=%d\n",
 615                            sch->schid.ssid, sch->schid.sch_no, rc);
 616                 return rc;
 617         }
 618         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 619                   sch->schid.ssid, sch->schid.sch_no);
 620         return count;
 621 }
 622
 623 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 624 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 625 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 626 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 627 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 628 static DEVICE_ATTR(online, 0644, online_show, online_store);
 629 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 630 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 631
 632 static struct attribute *io_subchannel_attrs[] = {
 633         &dev_attr_chpids.attr,
 634         &dev_attr_pimpampom.attr,
 635         &dev_attr_logging.attr,
 636         NULL,
 637 };
 638
 639 static struct attribute_group io_subchannel_attr_group = {
 640         .attrs = io_subchannel_attrs,
 641 };
 642
 643 static struct attribute * ccwdev_attrs[] = {
 644         &dev_attr_devtype.attr,
 645         &dev_attr_cutype.attr,
 646         &dev_attr_modalias.attr,
 647         &dev_attr_online.attr,
 648         &dev_attr_cmb_enable.attr,
 649         &dev_attr_availability.attr,
 650         NULL,
 651 };
 652
 653 static struct attribute_group ccwdev_attr_group = {
 654         .attrs = ccwdev_attrs,
 655 };
 656
 657 static const struct attribute_group *ccwdev_attr_groups[] = {
 658         &ccwdev_attr_group,
 659         NULL,
 660 };
 661
 662 /* this is a simple abstraction for device_register that sets the
 663  * correct bus type and adds the bus specific files */
 664 static int ccw_device_register(struct ccw_device *cdev)
 665 {
 666         struct device *dev = &cdev->dev;
 667         int ret;
 668
 669         dev->bus = &ccw_bus_type;
 670         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 671                            cdev->private->dev_id.devno);
 672         if (ret)
 673                 return ret;
 674         return device_add(dev);
 675 }
 676
 677 static int match_dev_id(struct device *dev, void *data)
 678 {
 679         struct ccw_device *cdev = to_ccwdev(dev);
 680         struct ccw_dev_id *dev_id = data;
 681
 682         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 683 }
 684
 685 static struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 686 {
 687         struct device *dev;
 688
 689         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 690
 691         return dev ? to_ccwdev(dev) : NULL;
 692 }
 693
 694 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 695 {
 696         int ret;
 697
 698         if (device_is_registered(&cdev->dev)) {
 699                 device_release_driver(&cdev->dev);
 700                 ret = device_attach(&cdev->dev);
 701                 WARN_ON(ret == -ENODEV);
 702         }
 703 }
 704
 705 static void
 706 ccw_device_release(struct device *dev)
 707 {
 708         struct ccw_device *cdev;
 709
 710         cdev = to_ccwdev(dev);
 711         /* Release reference of parent subchannel. */
 712         put_device(cdev->dev.parent);
 713         kfree(cdev->private);
 714         kfree(cdev);
 715 }
 716
 717 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 718 {
 719         struct ccw_device *cdev;
 720
 721         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 722         if (cdev) {
 723                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 724                                         GFP_KERNEL | GFP_DMA);
 725                 if (cdev->private)
 726                         return cdev;
 727         }
 728         kfree(cdev);
 729         return ERR_PTR(-ENOMEM);
 730 }
 731
 732 static void ccw_device_todo(struct work_struct *work);
 733
 734 static int io_subchannel_initialize_dev(struct subchannel *sch,
 735                                         struct ccw_device *cdev)
 736 {
 737         cdev->private->cdev = cdev;
 738         atomic_set(&cdev->private->onoff, 0);
 739         cdev->dev.parent = &sch->dev;
 740         cdev->dev.release = ccw_device_release;
 741         INIT_WORK(&cdev->private->todo_work, ccw_device_todo);
 742         cdev->dev.groups = ccwdev_attr_groups;
 743         /* Do first half of device_register. */
 744         device_initialize(&cdev->dev);
 745         if (!get_device(&sch->dev)) {
 746                 /* Release reference from device_initialize(). */
 747                 put_device(&cdev->dev);
 748                 return -ENODEV;
 749         }
 750         cdev->private->flags.initialized = 1;
 751         return 0;
 752 }
 753
 754 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 755 {
 756         struct ccw_device *cdev;
 757         int ret;
 758
 759         cdev = io_subchannel_allocate_dev(sch);
 760         if (!IS_ERR(cdev)) {
 761                 ret = io_subchannel_initialize_dev(sch, cdev);
 762                 if (ret)
 763                         cdev = ERR_PTR(ret);
 764         }
 765         return cdev;
 766 }
 767
 768 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 769
 770 static void sch_create_and_recog_new_device(struct subchannel *sch)
 771 {
 772         struct ccw_device *cdev;
 773
 774         /* Need to allocate a new ccw device. */
 775         cdev = io_subchannel_create_ccwdev(sch);
 776         if (IS_ERR(cdev)) {
 777                 /* OK, we did everything we could... */
 778                 css_sch_device_unregister(sch);
 779                 return;
 780         }
 781         /* Start recognition for the new ccw device. */
 782         io_subchannel_recog(cdev, sch);
 783 }
 784
 785 /*
 786  * Register recognized device.
 787  */
 788 static void io_subchannel_register(struct ccw_device *cdev)
 789 {
 790         struct subchannel *sch;
 791         int ret, adjust_init_count = 1;
 792         unsigned long flags;
 793
 794         sch = to_subchannel(cdev->dev.parent);
 795         /*
 796          * Check if subchannel is still registered. It may have become
 797          * unregistered if a machine check hit us after finishing
 798          * device recognition but before the register work could be
 799          * queued.
 800          */
 801         if (!device_is_registered(&sch->dev))
 802                 goto out_err;
 803         css_update_ssd_info(sch);
 804         /*
 805          * io_subchannel_register() will also be called after device
 806          * recognition has been done for a boxed device (which will already
 807          * be registered). We need to reprobe since we may now have sense id
 808          * information.
 809          */
 810         if (device_is_registered(&cdev->dev)) {
 811                 if (!cdev->drv) {
 812                         ret = device_reprobe(&cdev->dev);
 813                         if (ret)
 814                                 /* We can't do much here. */
 815                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 816                                               " %d for 0.%x.%04x\n", ret,
 817                                               cdev->private->dev_id.ssid,
 818                                               cdev->private->dev_id.devno);
 819                 }
 820                 adjust_init_count = 0;
 821                 goto out;
 822         }
 823         /*
 824          * Now we know this subchannel will stay, we can throw
 825          * our delayed uevent.
 826          */
 827         dev_set_uevent_suppress(&sch->dev, 0);
 828         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 829         /* make it known to the system */
 830         ret = ccw_device_register(cdev);
 831         if (ret) {
 832                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 833                               cdev->private->dev_id.ssid,
 834                               cdev->private->dev_id.devno, ret);
 835                 spin_lock_irqsave(sch->lock, flags);
 836                 sch_set_cdev(sch, NULL);
 837                 spin_unlock_irqrestore(sch->lock, flags);
 838                 /* Release initial device reference. */
 839                 put_device(&cdev->dev);
 840                 goto out_err;
 841         }
 842 out:
 843         cdev->private->flags.recog_done = 1;
 844         wake_up(&cdev->private->wait_q);
 845 out_err:
 846         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 847                 wake_up(&ccw_device_init_wq);
 848 }
 849
 850 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 851 {
 852         struct subchannel *sch;
 853
 854         /* Get subchannel reference for local processing. */
 855         if (!get_device(cdev->dev.parent))
 856                 return;
 857         sch = to_subchannel(cdev->dev.parent);
 858         css_sch_device_unregister(sch);
 859         /* Release subchannel reference for local processing. */
 860         put_device(&sch->dev);
 861 }
 862
 863 /*
 864  * subchannel recognition done. Called from the state machine.
 865  */
 866 void
 867 io_subchannel_recog_done(struct ccw_device *cdev)
 868 {
 869         if (css_init_done == 0) {
 870                 cdev->private->flags.recog_done = 1;
 871                 return;
 872         }
 873         switch (cdev->private->state) {
 874         case DEV_STATE_BOXED:
 875                 /* Device did not respond in time. */
 876         case DEV_STATE_NOT_OPER:
 877                 cdev->private->flags.recog_done = 1;
 878                 /* Remove device found not operational. */
 879                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 880                 if (atomic_dec_and_test(&ccw_device_init_count))
 881                         wake_up(&ccw_device_init_wq);
 882                 break;
 883         case DEV_STATE_OFFLINE:
 884                 /*
 885                  * We can't register the device in interrupt context so
 886                  * we schedule a work item.
 887                  */
 888                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 889                 break;
 890         }
 891 }
 892
 893 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 894 {
 895         struct ccw_device_private *priv;
 896
 897         cdev->ccwlock = sch->lock;
 898
 899         /* Init private data. */
 900         priv = cdev->private;
 901         priv->dev_id.devno = sch->schib.pmcw.dev;
 902         priv->dev_id.ssid = sch->schid.ssid;
 903         priv->schid = sch->schid;
 904         priv->state = DEV_STATE_NOT_OPER;
 905         INIT_LIST_HEAD(&priv->cmb_list);
 906         init_waitqueue_head(&priv->wait_q);
 907         init_timer(&priv->timer);
 908
 909         /* Increase counter of devices currently in recognition. */
 910         atomic_inc(&ccw_device_init_count);
 911
 912         /* Start async. device sensing. */
 913         spin_lock_irq(sch->lock);
 914         sch_set_cdev(sch, cdev);
 915         ccw_device_recognition(cdev);
 916         spin_unlock_irq(sch->lock);
 917 }
 918
 919 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 920                                   struct subchannel *sch)
 921 {
 922         struct subchannel *old_sch;
 923         int rc, old_enabled = 0;
 924
 925         old_sch = to_subchannel(cdev->dev.parent);
 926         /* Obtain child reference for new parent. */
 927         if (!get_device(&sch->dev))
 928                 return -ENODEV;
 929
 930         if (!sch_is_pseudo_sch(old_sch)) {
 931                 spin_lock_irq(old_sch->lock);
 932                 old_enabled = old_sch->schib.pmcw.ena;
 933                 rc = 0;
 934                 if (old_enabled)
 935                         rc = cio_disable_subchannel(old_sch);
 936                 spin_unlock_irq(old_sch->lock);
 937                 if (rc == -EBUSY) {
 938                         /* Release child reference for new parent. */
 939                         put_device(&sch->dev);
 940                         return rc;
 941                 }
 942         }
 943
 944         mutex_lock(&sch->reg_mutex);
 945         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 946         mutex_unlock(&sch->reg_mutex);
 947         if (rc) {
 948                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 949                               cdev->private->dev_id.ssid,
 950                               cdev->private->dev_id.devno, sch->schid.ssid,
 951                               sch->schib.pmcw.dev, rc);
 952                 if (old_enabled) {
 953                         /* Try to reenable the old subchannel. */
 954                         spin_lock_irq(old_sch->lock);
 955                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 956                         spin_unlock_irq(old_sch->lock);
 957                 }
 958                 /* Release child reference for new parent. */
 959                 put_device(&sch->dev);
 960                 return rc;
 961         }
 962         /* Clean up old subchannel. */
 963         if (!sch_is_pseudo_sch(old_sch)) {
 964                 spin_lock_irq(old_sch->lock);
 965                 sch_set_cdev(old_sch, NULL);
 966                 spin_unlock_irq(old_sch->lock);
 967                 css_schedule_eval(old_sch->schid);
 968         }
 969         /* Release child reference for old parent. */
 970         put_device(&old_sch->dev);
 971         /* Initialize new subchannel. */
 972         spin_lock_irq(sch->lock);
 973         cdev->private->schid = sch->schid;
 974         cdev->ccwlock = sch->lock;
 975         if (!sch_is_pseudo_sch(sch))
 976                 sch_set_cdev(sch, cdev);
 977         spin_unlock_irq(sch->lock);
 978         if (!sch_is_pseudo_sch(sch))
 979                 css_update_ssd_info(sch);
 980         return 0;
 981 }
 982
 983 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 984 {
 985         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 986         struct channel_subsystem *css = to_css(sch->dev.parent);
 987
 988         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 989 }
 990
 991 static void io_subchannel_irq(struct subchannel *sch)
 992 {
 993         struct ccw_device *cdev;
 994
 995         cdev = sch_get_cdev(sch);
 996
 997         CIO_TRACE_EVENT(6, "IRQ");
 998         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
 999         if (cdev)
1000                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1001 }
1002
1003 void io_subchannel_init_config(struct subchannel *sch)
1004 {
1005         memset(&sch->config, 0, sizeof(sch->config));
1006         sch->config.csense = 1;
1007 }
1008
1009 static void io_subchannel_init_fields(struct subchannel *sch)
1010 {
1011         if (cio_is_console(sch->schid))
1012                 sch->opm = 0xff;
1013         else
1014                 sch->opm = chp_get_sch_opm(sch);
1015         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1016         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1017
1018         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1019                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1020                       sch->schib.pmcw.dev, sch->schid.ssid,
1021                       sch->schid.sch_no, sch->schib.pmcw.pim,
1022                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1023
1024         io_subchannel_init_config(sch);
1025 }
1026
1027 /*
1028  * Note: We always return 0 so that we bind to the device even on error.
1029  * This is needed so that our remove function is called on unregister.
1030  */
1031 static int io_subchannel_probe(struct subchannel *sch)
1032 {
1033         struct ccw_device *cdev;
1034         int rc;
1035
1036         if (cio_is_console(sch->schid)) {
1037                 rc = sysfs_create_group(&sch->dev.kobj,
1038                                         &io_subchannel_attr_group);
1039                 if (rc)
1040                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1041                                       "attributes for subchannel "
1042                                       "0.%x.%04x (rc=%d)\n",
1043                                       sch->schid.ssid, sch->schid.sch_no, rc);
1044                 /*
1045                  * The console subchannel already has an associated ccw_device.
1046                  * Throw the delayed uevent for the subchannel, register
1047                  * the ccw_device and exit.
1048                  */
1049                 dev_set_uevent_suppress(&sch->dev, 0);
1050                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1051                 cdev = sch_get_cdev(sch);
1052                 cdev->dev.groups = ccwdev_attr_groups;
1053                 device_initialize(&cdev->dev);
1054                 cdev->private->flags.initialized = 1;
1055                 ccw_device_register(cdev);
1056                 /*
1057                  * Check if the device is already online. If it is
1058                  * the reference count needs to be corrected since we
1059                  * didn't obtain a reference in ccw_device_set_online.
1060                  */
1061                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1062                     cdev->private->state != DEV_STATE_OFFLINE &&
1063                     cdev->private->state != DEV_STATE_BOXED)
1064                         get_device(&cdev->dev);
1065                 return 0;
1066         }
1067         io_subchannel_init_fields(sch);
1068         rc = cio_commit_config(sch);
1069         if (rc)
1070                 goto out_schedule;
1071         rc = sysfs_create_group(&sch->dev.kobj,
1072                                 &io_subchannel_attr_group);
1073         if (rc)
1074                 goto out_schedule;
1075         /* Allocate I/O subchannel private data. */
1076         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1077                                GFP_KERNEL | GFP_DMA);
1078         if (!sch->private)
1079                 goto out_schedule;
1080         css_schedule_eval(sch->schid);
1081         return 0;
1082
1083 out_schedule:
1084         spin_lock_irq(sch->lock);
1085         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1086         spin_unlock_irq(sch->lock);
1087         return 0;
1088 }
1089
1090 static int
1091 io_subchannel_remove (struct subchannel *sch)
1092 {
1093         struct ccw_device *cdev;
1094
1095         cdev = sch_get_cdev(sch);
1096         if (!cdev)
1097                 goto out_free;
1098         io_subchannel_quiesce(sch);
1099         /* Set ccw device to not operational and drop reference. */
1100         spin_lock_irq(cdev->ccwlock);
1101         sch_set_cdev(sch, NULL);
1102         cdev->private->state = DEV_STATE_NOT_OPER;
1103         spin_unlock_irq(cdev->ccwlock);
1104         ccw_device_unregister(cdev);
1105 out_free:
1106         kfree(sch->private);
1107         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1108         return 0;
1109 }
1110
1111 static void io_subchannel_verify(struct subchannel *sch)
1112 {
1113         struct ccw_device *cdev;
1114
1115         cdev = sch_get_cdev(sch);
1116         if (cdev)
1117                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1118 }
1119
1120 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1121 {
1122         struct ccw_device *cdev;
1123
1124         cdev = sch_get_cdev(sch);
1125         if (!cdev)
1126                 return;
1127         if (cio_update_schib(sch))
1128                 goto err;
1129         /* Check for I/O on path. */
1130         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1131                 goto out;
1132         if (cdev->private->state == DEV_STATE_ONLINE) {
1133                 ccw_device_kill_io(cdev);
1134                 goto out;
1135         }
1136         if (cio_clear(sch))
1137                 goto err;
1138 out:
1139         /* Trigger path verification. */
1140         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1141         return;
1142
1143 err:
1144         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1145 }
1146
1147 static int io_subchannel_chp_event(struct subchannel *sch,
1148                                    struct chp_link *link, int event)
1149 {
1150         struct ccw_device *cdev = sch_get_cdev(sch);
1151         int mask;
1152
1153         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1154         if (!mask)
1155                 return 0;
1156         switch (event) {
1157         case CHP_VARY_OFF:
1158                 sch->opm &= ~mask;
1159                 sch->lpm &= ~mask;
1160                 if (cdev)
1161                         cdev->private->path_gone_mask |= mask;
1162                 io_subchannel_terminate_path(sch, mask);
1163                 break;
1164         case CHP_VARY_ON:
1165                 sch->opm |= mask;
1166                 sch->lpm |= mask;
1167                 if (cdev)
1168                         cdev->private->path_new_mask |= mask;
1169                 io_subchannel_verify(sch);
1170                 break;
1171         case CHP_OFFLINE:
1172                 if (cio_update_schib(sch))
1173                         return -ENODEV;
1174                 if (cdev)
1175                         cdev->private->path_gone_mask |= mask;
1176                 io_subchannel_terminate_path(sch, mask);
1177                 break;
1178         case CHP_ONLINE:
1179                 if (cio_update_schib(sch))
1180                         return -ENODEV;
1181                 sch->lpm |= mask & sch->opm;
1182                 if (cdev)
1183                         cdev->private->path_new_mask |= mask;
1184                 io_subchannel_verify(sch);
1185                 break;
1186         }
1187         return 0;
1188 }
1189
1190 static void io_subchannel_quiesce(struct subchannel *sch)
1191 {
1192         struct ccw_device *cdev;
1193         int ret;
1194
1195         spin_lock_irq(sch->lock);
1196         cdev = sch_get_cdev(sch);
1197         if (cio_is_console(sch->schid))
1198                 goto out_unlock;
1199         if (!sch->schib.pmcw.ena)
1200                 goto out_unlock;
1201         ret = cio_disable_subchannel(sch);
1202         if (ret != -EBUSY)
1203                 goto out_unlock;
1204         if (cdev->handler)
1205                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1206         while (ret == -EBUSY) {
1207                 cdev->private->state = DEV_STATE_QUIESCE;
1208                 cdev->private->iretry = 255;
1209                 ret = ccw_device_cancel_halt_clear(cdev);
1210                 if (ret == -EBUSY) {
1211                         ccw_device_set_timeout(cdev, HZ/10);
1212                         spin_unlock_irq(sch->lock);
1213                         wait_event(cdev->private->wait_q,
1214                                    cdev->private->state != DEV_STATE_QUIESCE);
1215                         spin_lock_irq(sch->lock);
1216                 }
1217                 ret = cio_disable_subchannel(sch);
1218         }
1219 out_unlock:
1220         spin_unlock_irq(sch->lock);
1221 }
1222
1223 static void io_subchannel_shutdown(struct subchannel *sch)
1224 {
1225         io_subchannel_quiesce(sch);
1226 }
1227
1228 static int device_is_disconnected(struct ccw_device *cdev)
1229 {
1230         if (!cdev)
1231                 return 0;
1232         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1233                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1234 }
1235
1236 static int recovery_check(struct device *dev, void *data)
1237 {
1238         struct ccw_device *cdev = to_ccwdev(dev);
1239         int *redo = data;
1240
1241         spin_lock_irq(cdev->ccwlock);
1242         switch (cdev->private->state) {
1243         case DEV_STATE_DISCONNECTED:
1244                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1245                               cdev->private->dev_id.ssid,
1246                               cdev->private->dev_id.devno);
1247                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1248                 *redo = 1;
1249                 break;
1250         case DEV_STATE_DISCONNECTED_SENSE_ID:
1251                 *redo = 1;
1252                 break;
1253         }
1254         spin_unlock_irq(cdev->ccwlock);
1255
1256         return 0;
1257 }
1258
1259 static void recovery_work_func(struct work_struct *unused)
1260 {
1261         int redo = 0;
1262
1263         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1264         if (redo) {
1265                 spin_lock_irq(&recovery_lock);
1266                 if (!timer_pending(&recovery_timer)) {
1267                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1268                                 recovery_phase++;
1269                         mod_timer(&recovery_timer, jiffies +
1270                                   recovery_delay[recovery_phase] * HZ);
1271                 }
1272                 spin_unlock_irq(&recovery_lock);
1273         } else
1274                 CIO_MSG_EVENT(4, "recovery: end\n");
1275 }
1276
1277 static DECLARE_WORK(recovery_work, recovery_work_func);
1278
1279 static void recovery_func(unsigned long data)
1280 {
1281         /*
1282          * We can't do our recovery in softirq context and it's not
1283          * performance critical, so we schedule it.
1284          */
1285         schedule_work(&recovery_work);
1286 }
1287
1288 static void ccw_device_schedule_recovery(void)
1289 {
1290         unsigned long flags;
1291
1292         CIO_MSG_EVENT(4, "recovery: schedule\n");
1293         spin_lock_irqsave(&recovery_lock, flags);
1294         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1295                 recovery_phase = 0;
1296                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1297         }
1298         spin_unlock_irqrestore(&recovery_lock, flags);
1299 }
1300
1301 static int purge_fn(struct device *dev, void *data)
1302 {
1303         struct ccw_device *cdev = to_ccwdev(dev);
1304         struct ccw_dev_id *id = &cdev->private->dev_id;
1305
1306         spin_lock_irq(cdev->ccwlock);
1307         if (is_blacklisted(id->ssid, id->devno) &&
1308             (cdev->private->state == DEV_STATE_OFFLINE)) {
1309                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1310                               id->devno);
1311                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1312         }
1313         spin_unlock_irq(cdev->ccwlock);
1314         /* Abort loop in case of pending signal. */
1315         if (signal_pending(current))
1316                 return -EINTR;
1317
1318         return 0;
1319 }
1320
1321 /**
1322  * ccw_purge_blacklisted - purge unused, blacklisted devices
1323  *
1324  * Unregister all ccw devices that are offline and on the blacklist.
1325  */
1326 int ccw_purge_blacklisted(void)
1327 {
1328         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1329         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1330         return 0;
1331 }
1332
1333 void ccw_device_set_disconnected(struct ccw_device *cdev)
1334 {
1335         if (!cdev)
1336                 return;
1337         ccw_device_set_timeout(cdev, 0);
1338         cdev->private->flags.fake_irb = 0;
1339         cdev->private->state = DEV_STATE_DISCONNECTED;
1340         if (cdev->online)
1341                 ccw_device_schedule_recovery();
1342 }
1343
1344 void ccw_device_set_notoper(struct ccw_device *cdev)
1345 {
1346         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1347
1348         CIO_TRACE_EVENT(2, "notoper");
1349         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1350         ccw_device_set_timeout(cdev, 0);
1351         cio_disable_subchannel(sch);
1352         cdev->private->state = DEV_STATE_NOT_OPER;
1353 }
1354
1355 enum io_sch_action {
1356         IO_SCH_UNREG,
1357         IO_SCH_ORPH_UNREG,
1358         IO_SCH_ATTACH,
1359         IO_SCH_UNREG_ATTACH,
1360         IO_SCH_ORPH_ATTACH,
1361         IO_SCH_REPROBE,
1362         IO_SCH_VERIFY,
1363         IO_SCH_DISC,
1364         IO_SCH_NOP,
1365 };
1366
1367 static enum io_sch_action sch_get_action(struct subchannel *sch)
1368 {
1369         struct ccw_device *cdev;
1370
1371         cdev = sch_get_cdev(sch);
1372         if (cio_update_schib(sch)) {
1373                 /* Not operational. */
1374                 if (!cdev)
1375                         return IO_SCH_UNREG;
1376                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1377                         return IO_SCH_UNREG;
1378                 return IO_SCH_ORPH_UNREG;
1379         }
1380         /* Operational. */
1381         if (!cdev)
1382                 return IO_SCH_ATTACH;
1383         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1384                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1385                         return IO_SCH_UNREG_ATTACH;
1386                 return IO_SCH_ORPH_ATTACH;
1387         }
1388         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1389                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1390                         return IO_SCH_UNREG;
1391                 return IO_SCH_DISC;
1392         }
1393         if (device_is_disconnected(cdev))
1394                 return IO_SCH_REPROBE;
1395         if (cdev->online)
1396                 return IO_SCH_VERIFY;
1397         return IO_SCH_NOP;
1398 }
1399
1400 /**
1401  * io_subchannel_sch_event - process subchannel event
1402  * @sch: subchannel
1403  * @process: non-zero if function is called in process context
1404  *
1405  * An unspecified event occurred for this subchannel. Adjust data according
1406  * to the current operational state of the subchannel and device. Return
1407  * zero when the event has been handled sufficiently or -EAGAIN when this
1408  * function should be called again in process context.
1409  */
1410 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1411 {
1412         unsigned long flags;
1413         struct ccw_device *cdev;
1414         struct ccw_dev_id dev_id;
1415         enum io_sch_action action;
1416         int rc = -EAGAIN;
1417
1418         spin_lock_irqsave(sch->lock, flags);
1419         if (!device_is_registered(&sch->dev))
1420                 goto out_unlock;
1421         if (work_pending(&sch->todo_work))
1422                 goto out_unlock;
1423         cdev = sch_get_cdev(sch);
1424         if (cdev && work_pending(&cdev->private->todo_work))
1425                 goto out_unlock;
1426         action = sch_get_action(sch);
1427         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1428                       sch->schid.ssid, sch->schid.sch_no, process,
1429                       action);
1430         /* Perform immediate actions while holding the lock. */
1431         switch (action) {
1432         case IO_SCH_REPROBE:
1433                 /* Trigger device recognition. */
1434                 ccw_device_trigger_reprobe(cdev);
1435                 rc = 0;
1436                 goto out_unlock;
1437         case IO_SCH_VERIFY:
1438                 if (cdev->private->flags.resuming == 1) {
1439                         if (cio_enable_subchannel(sch, (u32)(addr_t)sch)) {
1440                                 ccw_device_set_notoper(cdev);
1441                                 break;
1442                         }
1443                 }
1444                 /* Trigger path verification. */
1445                 io_subchannel_verify(sch);
1446                 rc = 0;
1447                 goto out_unlock;
1448         case IO_SCH_DISC:
1449                 ccw_device_set_disconnected(cdev);
1450                 rc = 0;
1451                 goto out_unlock;
1452         case IO_SCH_ORPH_UNREG:
1453         case IO_SCH_ORPH_ATTACH:
1454                 ccw_device_set_disconnected(cdev);
1455                 break;
1456         case IO_SCH_UNREG_ATTACH:
1457         case IO_SCH_UNREG:
1458                 if (!cdev)
1459                         break;
1460                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1461                         /*
1462                          * Note: delayed work triggered by this event
1463                          * and repeated calls to sch_event are synchronized
1464                          * by the above check for work_pending(cdev).
1465                          */
1466                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1467                 } else
1468                         ccw_device_set_notoper(cdev);
1469                 break;
1470         case IO_SCH_NOP:
1471                 rc = 0;
1472                 goto out_unlock;
1473         default:
1474                 break;
1475         }
1476         spin_unlock_irqrestore(sch->lock, flags);
1477         /* All other actions require process context. */
1478         if (!process)
1479                 goto out;
1480         /* Handle attached ccw device. */
1481         switch (action) {
1482         case IO_SCH_ORPH_UNREG:
1483         case IO_SCH_ORPH_ATTACH:
1484                 /* Move ccw device to orphanage. */
1485                 rc = ccw_device_move_to_orph(cdev);
1486                 if (rc)
1487                         goto out;
1488                 break;
1489         case IO_SCH_UNREG_ATTACH:
1490                 if (cdev->private->flags.resuming) {
1491                         /* Device will be handled later. */
1492                         rc = 0;
1493                         goto out;
1494                 }
1495                 /* Unregister ccw device. */
1496                 ccw_device_unregister(cdev);
1497                 break;
1498         default:
1499                 break;
1500         }
1501         /* Handle subchannel. */
1502         switch (action) {
1503         case IO_SCH_ORPH_UNREG:
1504         case IO_SCH_UNREG:
1505                 if (!cdev || !cdev->private->flags.resuming)
1506                         css_sch_device_unregister(sch);
1507                 break;
1508         case IO_SCH_ORPH_ATTACH:
1509         case IO_SCH_UNREG_ATTACH:
1510         case IO_SCH_ATTACH:
1511                 dev_id.ssid = sch->schid.ssid;
1512                 dev_id.devno = sch->schib.pmcw.dev;
1513                 cdev = get_ccwdev_by_dev_id(&dev_id);
1514                 if (!cdev) {
1515                         sch_create_and_recog_new_device(sch);
1516                         break;
1517                 }
1518                 rc = ccw_device_move_to_sch(cdev, sch);
1519                 if (rc) {
1520                         /* Release reference from get_ccwdev_by_dev_id() */
1521                         put_device(&cdev->dev);
1522                         goto out;
1523                 }
1524                 spin_lock_irqsave(sch->lock, flags);
1525                 ccw_device_trigger_reprobe(cdev);
1526                 spin_unlock_irqrestore(sch->lock, flags);
1527                 /* Release reference from get_ccwdev_by_dev_id() */
1528                 put_device(&cdev->dev);
1529                 break;
1530         default:
1531                 break;
1532         }
1533         return 0;
1534
1535 out_unlock:
1536         spin_unlock_irqrestore(sch->lock, flags);
1537 out:
1538         return rc;
1539 }
1540
1541 #ifdef CONFIG_CCW_CONSOLE
1542 static struct ccw_device console_cdev;
1543 static struct ccw_device_private console_private;
1544 static int console_cdev_in_use;
1545
1546 static DEFINE_SPINLOCK(ccw_console_lock);
1547
1548 spinlock_t * cio_get_console_lock(void)
1549 {
1550         return &ccw_console_lock;
1551 }
1552
1553 static int ccw_device_console_enable(struct ccw_device *cdev,
1554                                      struct subchannel *sch)
1555 {
1556         int rc;
1557
1558         /* Attach subchannel private data. */
1559         sch->private = cio_get_console_priv();
1560         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1561         io_subchannel_init_fields(sch);
1562         rc = cio_commit_config(sch);
1563         if (rc)
1564                 return rc;
1565         sch->driver = &io_subchannel_driver;
1566         /* Initialize the ccw_device structure. */
1567         cdev->dev.parent= &sch->dev;
1568         sch_set_cdev(sch, cdev);
1569         io_subchannel_recog(cdev, sch);
1570         /* Now wait for the async. recognition to come to an end. */
1571         spin_lock_irq(cdev->ccwlock);
1572         while (!dev_fsm_final_state(cdev))
1573                 wait_cons_dev();
1574         rc = -EIO;
1575         if (cdev->private->state != DEV_STATE_OFFLINE)
1576                 goto out_unlock;
1577         ccw_device_online(cdev);
1578         while (!dev_fsm_final_state(cdev))
1579                 wait_cons_dev();
1580         if (cdev->private->state != DEV_STATE_ONLINE)
1581                 goto out_unlock;
1582         rc = 0;
1583 out_unlock:
1584         spin_unlock_irq(cdev->ccwlock);
1585         return rc;
1586 }
1587
1588 struct ccw_device *
1589 ccw_device_probe_console(void)
1590 {
1591         struct subchannel *sch;
1592         int ret;
1593
1594         if (xchg(&console_cdev_in_use, 1) != 0)
1595                 return ERR_PTR(-EBUSY);
1596         sch = cio_probe_console();
1597         if (IS_ERR(sch)) {
1598                 console_cdev_in_use = 0;
1599                 return (void *) sch;
1600         }
1601         memset(&console_cdev, 0, sizeof(struct ccw_device));
1602         memset(&console_private, 0, sizeof(struct ccw_device_private));
1603         console_cdev.private = &console_private;
1604         console_private.cdev = &console_cdev;
1605         ret = ccw_device_console_enable(&console_cdev, sch);
1606         if (ret) {
1607                 cio_release_console();
1608                 console_cdev_in_use = 0;
1609                 return ERR_PTR(ret);
1610         }
1611         console_cdev.online = 1;
1612         return &console_cdev;
1613 }
1614
1615 static int ccw_device_pm_restore(struct device *dev);
1616
1617 int ccw_device_force_console(void)
1618 {
1619         if (!console_cdev_in_use)
1620                 return -ENODEV;
1621         return ccw_device_pm_restore(&console_cdev.dev);
1622 }
1623 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1624 #endif
1625
1626 /*
1627  * get ccw_device matching the busid, but only if owned by cdrv
1628  */
1629 static int
1630 __ccwdev_check_busid(struct device *dev, void *id)
1631 {
1632         char *bus_id;
1633
1634         bus_id = id;
1635
1636         return (strcmp(bus_id, dev_name(dev)) == 0);
1637 }
1638
1639
1640 /**
1641  * get_ccwdev_by_busid() - obtain device from a bus id
1642  * @cdrv: driver the device is owned by
1643  * @bus_id: bus id of the device to be searched
1644  *
1645  * This function searches all devices owned by @cdrv for a device with a bus
1646  * id matching @bus_id.
1647  * Returns:
1648  *  If a match is found, its reference count of the found device is increased
1649  *  and it is returned; else %NULL is returned.
1650  */
1651 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1652                                        const char *bus_id)
1653 {
1654         struct device *dev;
1655         struct device_driver *drv;
1656
1657         drv = get_driver(&cdrv->driver);
1658         if (!drv)
1659                 return NULL;
1660
1661         dev = driver_find_device(drv, NULL, (void *)bus_id,
1662                                  __ccwdev_check_busid);
1663         put_driver(drv);
1664
1665         return dev ? to_ccwdev(dev) : NULL;
1666 }
1667
1668 /************************** device driver handling ************************/
1669
1670 /* This is the implementation of the ccw_driver class. The probe, remove
1671  * and release methods are initially very similar to the device_driver
1672  * implementations, with the difference that they have ccw_device
1673  * arguments.
1674  *
1675  * A ccw driver also contains the information that is needed for
1676  * device matching.
1677  */
1678 static int
1679 ccw_device_probe (struct device *dev)
1680 {
1681         struct ccw_device *cdev = to_ccwdev(dev);
1682         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1683         int ret;
1684
1685         cdev->drv = cdrv; /* to let the driver call _set_online */
1686
1687         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1688
1689         if (ret) {
1690                 cdev->drv = NULL;
1691                 return ret;
1692         }
1693
1694         return 0;
1695 }
1696
1697 static int
1698 ccw_device_remove (struct device *dev)
1699 {
1700         struct ccw_device *cdev = to_ccwdev(dev);
1701         struct ccw_driver *cdrv = cdev->drv;
1702         int ret;
1703
1704         if (cdrv->remove)
1705                 cdrv->remove(cdev);
1706         if (cdev->online) {
1707                 cdev->online = 0;
1708                 spin_lock_irq(cdev->ccwlock);
1709                 ret = ccw_device_offline(cdev);
1710                 spin_unlock_irq(cdev->ccwlock);
1711                 if (ret == 0)
1712                         wait_event(cdev->private->wait_q,
1713                                    dev_fsm_final_state(cdev));
1714                 else
1715                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1716                                       "device 0.%x.%04x\n",
1717                                       ret, cdev->private->dev_id.ssid,
1718                                       cdev->private->dev_id.devno);
1719                 /* Give up reference obtained in ccw_device_set_online(). */
1720                 put_device(&cdev->dev);
1721         }
1722         ccw_device_set_timeout(cdev, 0);
1723         cdev->drv = NULL;
1724         return 0;
1725 }
1726
1727 static void ccw_device_shutdown(struct device *dev)
1728 {
1729         struct ccw_device *cdev;
1730
1731         cdev = to_ccwdev(dev);
1732         if (cdev->drv && cdev->drv->shutdown)
1733                 cdev->drv->shutdown(cdev);
1734         disable_cmf(cdev);
1735 }
1736
1737 static int ccw_device_pm_prepare(struct device *dev)
1738 {
1739         struct ccw_device *cdev = to_ccwdev(dev);
1740
1741         if (work_pending(&cdev->private->todo_work))
1742                 return -EAGAIN;
1743         /* Fail while device is being set online/offline. */
1744         if (atomic_read(&cdev->private->onoff))
1745                 return -EAGAIN;
1746
1747         if (cdev->online && cdev->drv && cdev->drv->prepare)
1748                 return cdev->drv->prepare(cdev);
1749
1750         return 0;
1751 }
1752
1753 static void ccw_device_pm_complete(struct device *dev)
1754 {
1755         struct ccw_device *cdev = to_ccwdev(dev);
1756
1757         if (cdev->online && cdev->drv && cdev->drv->complete)
1758                 cdev->drv->complete(cdev);
1759 }
1760
1761 static int ccw_device_pm_freeze(struct device *dev)
1762 {
1763         struct ccw_device *cdev = to_ccwdev(dev);
1764         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1765         int ret, cm_enabled;
1766
1767         /* Fail suspend while device is in transistional state. */
1768         if (!dev_fsm_final_state(cdev))
1769                 return -EAGAIN;
1770         if (!cdev->online)
1771                 return 0;
1772         if (cdev->drv && cdev->drv->freeze) {
1773                 ret = cdev->drv->freeze(cdev);
1774                 if (ret)
1775                         return ret;
1776         }
1777
1778         spin_lock_irq(sch->lock);
1779         cm_enabled = cdev->private->cmb != NULL;
1780         spin_unlock_irq(sch->lock);
1781         if (cm_enabled) {
1782                 /* Don't have the css write on memory. */
1783                 ret = ccw_set_cmf(cdev, 0);
1784                 if (ret)
1785                         return ret;
1786         }
1787         /* From here on, disallow device driver I/O. */
1788         spin_lock_irq(sch->lock);
1789         ret = cio_disable_subchannel(sch);
1790         spin_unlock_irq(sch->lock);
1791
1792         return ret;
1793 }
1794
1795 static int ccw_device_pm_thaw(struct device *dev)
1796 {
1797         struct ccw_device *cdev = to_ccwdev(dev);
1798         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1799         int ret, cm_enabled;
1800
1801         if (!cdev->online)
1802                 return 0;
1803
1804         spin_lock_irq(sch->lock);
1805         /* Allow device driver I/O again. */
1806         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1807         cm_enabled = cdev->private->cmb != NULL;
1808         spin_unlock_irq(sch->lock);
1809         if (ret)
1810                 return ret;
1811
1812         if (cm_enabled) {
1813                 ret = ccw_set_cmf(cdev, 1);
1814                 if (ret)
1815                         return ret;
1816         }
1817
1818         if (cdev->drv && cdev->drv->thaw)
1819                 ret = cdev->drv->thaw(cdev);
1820
1821         return ret;
1822 }
1823
1824 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1825 {
1826         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1827
1828         spin_lock_irq(sch->lock);
1829         if (cio_is_console(sch->schid)) {
1830                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1831                 goto out_unlock;
1832         }
1833         /*
1834          * While we were sleeping, devices may have gone or become
1835          * available again. Kick re-detection.
1836          */
1837         cdev->private->flags.resuming = 1;
1838         cdev->private->path_new_mask = LPM_ANYPATH;
1839         css_schedule_eval(sch->schid);
1840         spin_unlock_irq(sch->lock);
1841         css_complete_work();
1842
1843         /* cdev may have been moved to a different subchannel. */
1844         sch = to_subchannel(cdev->dev.parent);
1845         spin_lock_irq(sch->lock);
1846         if (cdev->private->state != DEV_STATE_ONLINE &&
1847             cdev->private->state != DEV_STATE_OFFLINE)
1848                 goto out_unlock;
1849
1850         ccw_device_recognition(cdev);
1851         spin_unlock_irq(sch->lock);
1852         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1853                    cdev->private->state == DEV_STATE_DISCONNECTED);
1854         spin_lock_irq(sch->lock);
1855
1856 out_unlock:
1857         cdev->private->flags.resuming = 0;
1858         spin_unlock_irq(sch->lock);
1859 }
1860
1861 static int resume_handle_boxed(struct ccw_device *cdev)
1862 {
1863         cdev->private->state = DEV_STATE_BOXED;
1864         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1865                 return 0;
1866         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1867         return -ENODEV;
1868 }
1869
1870 static int resume_handle_disc(struct ccw_device *cdev)
1871 {
1872         cdev->private->state = DEV_STATE_DISCONNECTED;
1873         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1874                 return 0;
1875         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1876         return -ENODEV;
1877 }
1878
1879 static int ccw_device_pm_restore(struct device *dev)
1880 {
1881         struct ccw_device *cdev = to_ccwdev(dev);
1882         struct subchannel *sch;
1883         int ret = 0;
1884
1885         __ccw_device_pm_restore(cdev);
1886         sch = to_subchannel(cdev->dev.parent);
1887         spin_lock_irq(sch->lock);
1888         if (cio_is_console(sch->schid))
1889                 goto out_restore;
1890
1891         /* check recognition results */
1892         switch (cdev->private->state) {
1893         case DEV_STATE_OFFLINE:
1894         case DEV_STATE_ONLINE:
1895                 cdev->private->flags.donotify = 0;
1896                 break;
1897         case DEV_STATE_BOXED:
1898                 ret = resume_handle_boxed(cdev);
1899                 if (ret)
1900                         goto out_unlock;
1901                 goto out_restore;
1902         default:
1903                 ret = resume_handle_disc(cdev);
1904                 if (ret)
1905                         goto out_unlock;
1906                 goto out_restore;
1907         }
1908         /* check if the device type has changed */
1909         if (!ccw_device_test_sense_data(cdev)) {
1910                 ccw_device_update_sense_data(cdev);
1911                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1912                 ret = -ENODEV;
1913                 goto out_unlock;
1914         }
1915         if (!cdev->online)
1916                 goto out_unlock;
1917
1918         if (ccw_device_online(cdev)) {
1919                 ret = resume_handle_disc(cdev);
1920                 if (ret)
1921                         goto out_unlock;
1922                 goto out_restore;
1923         }
1924         spin_unlock_irq(sch->lock);
1925         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1926         spin_lock_irq(sch->lock);
1927
1928         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1929                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1930                 ret = -ENODEV;
1931                 goto out_unlock;
1932         }
1933
1934         /* reenable cmf, if needed */
1935         if (cdev->private->cmb) {
1936                 spin_unlock_irq(sch->lock);
1937                 ret = ccw_set_cmf(cdev, 1);
1938                 spin_lock_irq(sch->lock);
1939                 if (ret) {
1940                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1941                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1942                                       cdev->private->dev_id.devno, ret);
1943                         ret = 0;
1944                 }
1945         }
1946
1947 out_restore:
1948         spin_unlock_irq(sch->lock);
1949         if (cdev->online && cdev->drv && cdev->drv->restore)
1950                 ret = cdev->drv->restore(cdev);
1951         return ret;
1952
1953 out_unlock:
1954         spin_unlock_irq(sch->lock);
1955         return ret;
1956 }
1957
1958 static const struct dev_pm_ops ccw_pm_ops = {
1959         .prepare = ccw_device_pm_prepare,
1960         .complete = ccw_device_pm_complete,
1961         .freeze = ccw_device_pm_freeze,
1962         .thaw = ccw_device_pm_thaw,
1963         .restore = ccw_device_pm_restore,
1964 };
1965
1966 struct bus_type ccw_bus_type = {
1967         .name   = "ccw",
1968         .match  = ccw_bus_match,
1969         .uevent = ccw_uevent,
1970         .probe  = ccw_device_probe,
1971         .remove = ccw_device_remove,
1972         .shutdown = ccw_device_shutdown,
1973         .pm = &ccw_pm_ops,
1974 };
1975
1976 /**
1977  * ccw_driver_register() - register a ccw driver
1978  * @cdriver: driver to be registered
1979  *
1980  * This function is mainly a wrapper around driver_register().
1981  * Returns:
1982  *   %0 on success and a negative error value on failure.
1983  */
1984 int ccw_driver_register(struct ccw_driver *cdriver)
1985 {
1986         struct device_driver *drv = &cdriver->driver;
1987
1988         drv->bus = &ccw_bus_type;
1989         drv->name = cdriver->name;
1990         drv->owner = cdriver->owner;
1991
1992         return driver_register(drv);
1993 }
1994
1995 /**
1996  * ccw_driver_unregister() - deregister a ccw driver
1997  * @cdriver: driver to be deregistered
1998  *
1999  * This function is mainly a wrapper around driver_unregister().
2000  */
2001 void ccw_driver_unregister(struct ccw_driver *cdriver)
2002 {
2003         driver_unregister(&cdriver->driver);
2004 }
2005
2006 /* Helper func for qdio. */
2007 struct subchannel_id
2008 ccw_device_get_subchannel_id(struct ccw_device *cdev)
2009 {
2010         struct subchannel *sch;
2011
2012         sch = to_subchannel(cdev->dev.parent);
2013         return sch->schid;
2014 }
2015
2016 static void ccw_device_todo(struct work_struct *work)
2017 {
2018         struct ccw_device_private *priv;
2019         struct ccw_device *cdev;
2020         struct subchannel *sch;
2021         enum cdev_todo todo;
2022
2023         priv = container_of(work, struct ccw_device_private, todo_work);
2024         cdev = priv->cdev;
2025         sch = to_subchannel(cdev->dev.parent);
2026         /* Find out todo. */
2027         spin_lock_irq(cdev->ccwlock);
2028         todo = priv->todo;
2029         priv->todo = CDEV_TODO_NOTHING;
2030         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2031                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2032         spin_unlock_irq(cdev->ccwlock);
2033         /* Perform todo. */
2034         switch (todo) {
2035         case CDEV_TODO_ENABLE_CMF:
2036                 cmf_reenable(cdev);
2037                 break;
2038         case CDEV_TODO_REBIND:
2039                 ccw_device_do_unbind_bind(cdev);
2040                 break;
2041         case CDEV_TODO_REGISTER:
2042                 io_subchannel_register(cdev);
2043                 break;
2044         case CDEV_TODO_UNREG_EVAL:
2045                 if (!sch_is_pseudo_sch(sch))
2046                         css_schedule_eval(sch->schid);
2047                 /* fall-through */
2048         case CDEV_TODO_UNREG:
2049                 if (sch_is_pseudo_sch(sch))
2050                         ccw_device_unregister(cdev);
2051                 else
2052                         ccw_device_call_sch_unregister(cdev);
2053                 break;
2054         default:
2055                 break;
2056         }
2057         /* Release workqueue ref. */
2058         put_device(&cdev->dev);
2059 }
2060
2061 /**
2062  * ccw_device_sched_todo - schedule ccw device operation
2063  * @cdev: ccw device
2064  * @todo: todo
2065  *
2066  * Schedule the operation identified by @todo to be performed on the slow path
2067  * workqueue. Do nothing if another operation with higher priority is already
2068  * scheduled. Needs to be called with ccwdev lock held.
2069  */
2070 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2071 {
2072         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2073                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2074                       todo);
2075         if (cdev->private->todo >= todo)
2076                 return;
2077         cdev->private->todo = todo;
2078         /* Get workqueue ref. */
2079         if (!get_device(&cdev->dev))
2080                 return;
2081         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2082                 /* Already queued, release workqueue ref. */
2083                 put_device(&cdev->dev);
2084         }
2085 }
2086
2087 /**
2088  * ccw_device_siosl() - initiate logging
2089  * @cdev: ccw device
2090  *
2091  * This function is used to invoke model-dependent logging within the channel
2092  * subsystem.
2093  */
2094 int ccw_device_siosl(struct ccw_device *cdev)
2095 {
2096         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2097
2098         return chsc_siosl(sch->schid);
2099 }
2100 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2101
2102 MODULE_LICENSE("GPL");
2103 EXPORT_SYMBOL(ccw_device_set_online);
2104 EXPORT_SYMBOL(ccw_device_set_offline);
2105 EXPORT_SYMBOL(ccw_driver_register);
2106 EXPORT_SYMBOL(ccw_driver_unregister);
2107 EXPORT_SYMBOL(get_ccwdev_by_busid);
2108 EXPORT_SYMBOL(ccw_bus_type);
2109 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);