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 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/errno.h>
  14 #include <linux/err.h>
  15 #include <linux/slab.h>
  16 #include <linux/list.h>
  17 #include <linux/device.h>
  18 #include <linux/workqueue.h>
  19 #include <linux/timer.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24 #include <asm/cmb.h>
  25 #include <asm/isc.h>
  26
  27 #include "chp.h"
  28 #include "cio.h"
  29 #include "cio_debug.h"
  30 #include "css.h"
  31 #include "device.h"
  32 #include "ioasm.h"
  33 #include "io_sch.h"
  34 #include "blacklist.h"
  35
  36 static struct timer_list recovery_timer;
  37 static DEFINE_SPINLOCK(recovery_lock);
  38 static int recovery_phase;
  39 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  40
  41 /******************* bus type handling ***********************/
  42
  43 /* The Linux driver model distinguishes between a bus type and
  44  * the bus itself. Of course we only have one channel
  45  * subsystem driver and one channel system per machine, but
  46  * we still use the abstraction. T.R. says it's a good idea. */
  47 static int
  48 ccw_bus_match (struct device * dev, struct device_driver * drv)
  49 {
  50         struct ccw_device *cdev = to_ccwdev(dev);
  51         struct ccw_driver *cdrv = to_ccwdrv(drv);
  52         const struct ccw_device_id *ids = cdrv->ids, *found;
  53
  54         if (!ids)
  55                 return 0;
  56
  57         found = ccw_device_id_match(ids, &cdev->id);
  58         if (!found)
  59                 return 0;
  60
  61         cdev->id.driver_info = found->driver_info;
  62
  63         return 1;
  64 }
  65
  66 /* Store modalias string delimited by prefix/suffix string into buffer with
  67  * specified size. Return length of resulting string (excluding trailing '\0')
  68  * even if string doesn't fit buffer (snprintf semantics). */
  69 static int snprint_alias(char *buf, size_t size,
  70                          struct ccw_device_id *id, const char *suffix)
  71 {
  72         int len;
  73
  74         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  75         if (len > size)
  76                 return len;
  77         buf += len;
  78         size -= len;
  79
  80         if (id->dev_type != 0)
  81                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  82                                 id->dev_model, suffix);
  83         else
  84                 len += snprintf(buf, size, "dtdm%s", suffix);
  85
  86         return len;
  87 }
  88
  89 /* Set up environment variables for ccw device uevent. Return 0 on success,
  90  * non-zero otherwise. */
  91 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  92 {
  93         struct ccw_device *cdev = to_ccwdev(dev);
  94         struct ccw_device_id *id = &(cdev->id);
  95         int ret;
  96         char modalias_buf[30];
  97
  98         /* CU_TYPE= */
  99         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 100         if (ret)
 101                 return ret;
 102
 103         /* CU_MODEL= */
 104         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 105         if (ret)
 106                 return ret;
 107
 108         /* The next two can be zero, that's ok for us */
 109         /* DEV_TYPE= */
 110         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 111         if (ret)
 112                 return ret;
 113
 114         /* DEV_MODEL= */
 115         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 116         if (ret)
 117                 return ret;
 118
 119         /* MODALIAS=  */
 120         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 121         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 122         return ret;
 123 }
 124
 125 struct bus_type ccw_bus_type;
 126
 127 static void io_subchannel_irq(struct subchannel *);
 128 static int io_subchannel_probe(struct subchannel *);
 129 static int io_subchannel_remove(struct subchannel *);
 130 static void io_subchannel_shutdown(struct subchannel *);
 131 static int io_subchannel_sch_event(struct subchannel *, int);
 132 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 133                                    int);
 134
 135 static struct css_device_id io_subchannel_ids[] = {
 136         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 137         { /* end of list */ },
 138 };
 139 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 140
 141 static int io_subchannel_prepare(struct subchannel *sch)
 142 {
 143         struct ccw_device *cdev;
 144         /*
 145          * Don't allow suspend while a ccw device registration
 146          * is still outstanding.
 147          */
 148         cdev = sch_get_cdev(sch);
 149         if (cdev && !device_is_registered(&cdev->dev))
 150                 return -EAGAIN;
 151         return 0;
 152 }
 153
 154 static struct css_driver io_subchannel_driver = {
 155         .owner = THIS_MODULE,
 156         .subchannel_type = io_subchannel_ids,
 157         .name = "io_subchannel",
 158         .irq = io_subchannel_irq,
 159         .sch_event = io_subchannel_sch_event,
 160         .chp_event = io_subchannel_chp_event,
 161         .probe = io_subchannel_probe,
 162         .remove = io_subchannel_remove,
 163         .shutdown = io_subchannel_shutdown,
 164         .prepare = io_subchannel_prepare,
 165 };
 166
 167 struct workqueue_struct *ccw_device_work;
 168 wait_queue_head_t ccw_device_init_wq;
 169 atomic_t ccw_device_init_count;
 170
 171 static void recovery_func(unsigned long data);
 172
 173 static int __init
 174 init_ccw_bus_type (void)
 175 {
 176         int ret;
 177
 178         init_waitqueue_head(&ccw_device_init_wq);
 179         atomic_set(&ccw_device_init_count, 0);
 180         setup_timer(&recovery_timer, recovery_func, 0);
 181
 182         ccw_device_work = create_singlethread_workqueue("cio");
 183         if (!ccw_device_work)
 184                 return -ENOMEM; /* FIXME: better errno ? */
 185         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 186         if (!slow_path_wq) {
 187                 ret = -ENOMEM; /* FIXME: better errno ? */
 188                 goto out_err;
 189         }
 190         if ((ret = bus_register (&ccw_bus_type)))
 191                 goto out_err;
 192
 193         ret = css_driver_register(&io_subchannel_driver);
 194         if (ret)
 195                 goto out_err;
 196
 197         wait_event(ccw_device_init_wq,
 198                    atomic_read(&ccw_device_init_count) == 0);
 199         flush_workqueue(ccw_device_work);
 200         return 0;
 201 out_err:
 202         if (ccw_device_work)
 203                 destroy_workqueue(ccw_device_work);
 204         if (slow_path_wq)
 205                 destroy_workqueue(slow_path_wq);
 206         return ret;
 207 }
 208
 209 static void __exit
 210 cleanup_ccw_bus_type (void)
 211 {
 212         css_driver_unregister(&io_subchannel_driver);
 213         bus_unregister(&ccw_bus_type);
 214         destroy_workqueue(ccw_device_work);
 215 }
 216
 217 subsys_initcall(init_ccw_bus_type);
 218 module_exit(cleanup_ccw_bus_type);
 219
 220 /************************ device handling **************************/
 221
 222 /*
 223  * A ccw_device has some interfaces in sysfs in addition to the
 224  * standard ones.
 225  * The following entries are designed to export the information which
 226  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 227  * are obvious, so they don't have an entry :)
 228  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 229  */
 230 static ssize_t
 231 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 232 {
 233         struct subchannel *sch = to_subchannel(dev);
 234         struct chsc_ssd_info *ssd = &sch->ssd_info;
 235         ssize_t ret = 0;
 236         int chp;
 237         int mask;
 238
 239         for (chp = 0; chp < 8; chp++) {
 240                 mask = 0x80 >> chp;
 241                 if (ssd->path_mask & mask)
 242                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 243                 else
 244                         ret += sprintf(buf + ret, "00 ");
 245         }
 246         ret += sprintf (buf+ret, "\n");
 247         return min((ssize_t)PAGE_SIZE, ret);
 248 }
 249
 250 static ssize_t
 251 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 252 {
 253         struct subchannel *sch = to_subchannel(dev);
 254         struct pmcw *pmcw = &sch->schib.pmcw;
 255
 256         return sprintf (buf, "%02x %02x %02x\n",
 257                         pmcw->pim, pmcw->pam, pmcw->pom);
 258 }
 259
 260 static ssize_t
 261 devtype_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         if (id->dev_type != 0)
 267                 return sprintf(buf, "%04x/%02x\n",
 268                                 id->dev_type, id->dev_model);
 269         else
 270                 return sprintf(buf, "n/a\n");
 271 }
 272
 273 static ssize_t
 274 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 275 {
 276         struct ccw_device *cdev = to_ccwdev(dev);
 277         struct ccw_device_id *id = &(cdev->id);
 278
 279         return sprintf(buf, "%04x/%02x\n",
 280                        id->cu_type, id->cu_model);
 281 }
 282
 283 static ssize_t
 284 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 285 {
 286         struct ccw_device *cdev = to_ccwdev(dev);
 287         struct ccw_device_id *id = &(cdev->id);
 288         int len;
 289
 290         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 291
 292         return len > PAGE_SIZE ? PAGE_SIZE : len;
 293 }
 294
 295 static ssize_t
 296 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 297 {
 298         struct ccw_device *cdev = to_ccwdev(dev);
 299
 300         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 301 }
 302
 303 int ccw_device_is_orphan(struct ccw_device *cdev)
 304 {
 305         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 306 }
 307
 308 static void ccw_device_unregister(struct ccw_device *cdev)
 309 {
 310         if (test_and_clear_bit(1, &cdev->private->registered))
 311                 device_del(&cdev->dev);
 312 }
 313
 314 static void ccw_device_remove_orphan_cb(struct work_struct *work)
 315 {
 316         struct ccw_device_private *priv;
 317         struct ccw_device *cdev;
 318
 319         priv = container_of(work, struct ccw_device_private, kick_work);
 320         cdev = priv->cdev;
 321         ccw_device_unregister(cdev);
 322         put_device(&cdev->dev);
 323         /* Release cdev reference for workqueue processing. */
 324         put_device(&cdev->dev);
 325 }
 326
 327 static void
 328 ccw_device_remove_disconnected(struct ccw_device *cdev)
 329 {
 330         unsigned long flags;
 331
 332         /*
 333          * Forced offline in disconnected state means
 334          * 'throw away device'.
 335          */
 336         /* Get cdev reference for workqueue processing. */
 337         if (!get_device(&cdev->dev))
 338                 return;
 339         if (ccw_device_is_orphan(cdev)) {
 340                 /*
 341                  * Deregister ccw device.
 342                  * Unfortunately, we cannot do this directly from the
 343                  * attribute method.
 344                  */
 345                 spin_lock_irqsave(cdev->ccwlock, flags);
 346                 cdev->private->state = DEV_STATE_NOT_OPER;
 347                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 348                 PREPARE_WORK(&cdev->private->kick_work,
 349                                 ccw_device_remove_orphan_cb);
 350                 queue_work(slow_path_wq, &cdev->private->kick_work);
 351         } else
 352                 /* Deregister subchannel, which will kill the ccw device. */
 353                 ccw_device_schedule_sch_unregister(cdev);
 354 }
 355
 356 /**
 357  * ccw_device_set_offline() - disable a ccw device for I/O
 358  * @cdev: target ccw device
 359  *
 360  * This function calls the driver's set_offline() function for @cdev, if
 361  * given, and then disables @cdev.
 362  * Returns:
 363  *   %0 on success and a negative error value on failure.
 364  * Context:
 365  *  enabled, ccw device lock not held
 366  */
 367 int ccw_device_set_offline(struct ccw_device *cdev)
 368 {
 369         int ret;
 370
 371         if (!cdev)
 372                 return -ENODEV;
 373         if (!cdev->online || !cdev->drv)
 374                 return -EINVAL;
 375
 376         if (cdev->drv->set_offline) {
 377                 ret = cdev->drv->set_offline(cdev);
 378                 if (ret != 0)
 379                         return ret;
 380         }
 381         cdev->online = 0;
 382         spin_lock_irq(cdev->ccwlock);
 383         ret = ccw_device_offline(cdev);
 384         if (ret == -ENODEV) {
 385                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 386                         cdev->private->state = DEV_STATE_OFFLINE;
 387                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 388                 }
 389                 spin_unlock_irq(cdev->ccwlock);
 390                 /* Give up reference from ccw_device_set_online(). */
 391                 put_device(&cdev->dev);
 392                 return ret;
 393         }
 394         spin_unlock_irq(cdev->ccwlock);
 395         if (ret == 0) {
 396                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 397                 /* Give up reference from ccw_device_set_online(). */
 398                 put_device(&cdev->dev);
 399         } else {
 400                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 401                               "device 0.%x.%04x\n",
 402                               ret, cdev->private->dev_id.ssid,
 403                               cdev->private->dev_id.devno);
 404                 cdev->online = 1;
 405         }
 406         return ret;
 407 }
 408
 409 /**
 410  * ccw_device_set_online() - enable a ccw device for I/O
 411  * @cdev: target ccw device
 412  *
 413  * This function first enables @cdev and then calls the driver's set_online()
 414  * function for @cdev, if given. If set_online() returns an error, @cdev is
 415  * disabled again.
 416  * Returns:
 417  *   %0 on success and a negative error value on failure.
 418  * Context:
 419  *  enabled, ccw device lock not held
 420  */
 421 int ccw_device_set_online(struct ccw_device *cdev)
 422 {
 423         int ret;
 424
 425         if (!cdev)
 426                 return -ENODEV;
 427         if (cdev->online || !cdev->drv)
 428                 return -EINVAL;
 429         /* Hold on to an extra reference while device is online. */
 430         if (!get_device(&cdev->dev))
 431                 return -ENODEV;
 432
 433         spin_lock_irq(cdev->ccwlock);
 434         ret = ccw_device_online(cdev);
 435         spin_unlock_irq(cdev->ccwlock);
 436         if (ret == 0)
 437                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 438         else {
 439                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 440                               "device 0.%x.%04x\n",
 441                               ret, cdev->private->dev_id.ssid,
 442                               cdev->private->dev_id.devno);
 443                 /* Give up online reference since onlining failed. */
 444                 put_device(&cdev->dev);
 445                 return ret;
 446         }
 447         if (cdev->private->state != DEV_STATE_ONLINE) {
 448                 /* Give up online reference since onlining failed. */
 449                 put_device(&cdev->dev);
 450                 return -ENODEV;
 451         }
 452         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 453                 cdev->online = 1;
 454                 return 0;
 455         }
 456         spin_lock_irq(cdev->ccwlock);
 457         ret = ccw_device_offline(cdev);
 458         spin_unlock_irq(cdev->ccwlock);
 459         if (ret == 0)
 460                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 461         else
 462                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 463                               "device 0.%x.%04x\n",
 464                               ret, cdev->private->dev_id.ssid,
 465                               cdev->private->dev_id.devno);
 466         /* Give up online reference since onlining failed. */
 467         put_device(&cdev->dev);
 468         return (ret == 0) ? -ENODEV : ret;
 469 }
 470
 471 static int online_store_handle_offline(struct ccw_device *cdev)
 472 {
 473         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 474                 ccw_device_remove_disconnected(cdev);
 475         else if (cdev->online && cdev->drv && cdev->drv->set_offline)
 476                 return ccw_device_set_offline(cdev);
 477         return 0;
 478 }
 479
 480 static int online_store_recog_and_online(struct ccw_device *cdev)
 481 {
 482         int ret;
 483
 484         /* Do device recognition, if needed. */
 485         if (cdev->private->state == DEV_STATE_BOXED) {
 486                 ret = ccw_device_recognition(cdev);
 487                 if (ret) {
 488                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 489                                       "for device 0.%x.%04x (ret=%d)\n",
 490                                       cdev->private->dev_id.ssid,
 491                                       cdev->private->dev_id.devno, ret);
 492                         return ret;
 493                 }
 494                 wait_event(cdev->private->wait_q,
 495                            cdev->private->flags.recog_done);
 496                 if (cdev->private->state != DEV_STATE_OFFLINE)
 497                         /* recognition failed */
 498                         return -EAGAIN;
 499         }
 500         if (cdev->drv && cdev->drv->set_online)
 501                 ccw_device_set_online(cdev);
 502         return 0;
 503 }
 504
 505 static int online_store_handle_online(struct ccw_device *cdev, int force)
 506 {
 507         int ret;
 508
 509         ret = online_store_recog_and_online(cdev);
 510         if (ret && !force)
 511                 return ret;
 512         if (force && cdev->private->state == DEV_STATE_BOXED) {
 513                 ret = ccw_device_stlck(cdev);
 514                 if (ret)
 515                         return ret;
 516                 if (cdev->id.cu_type == 0)
 517                         cdev->private->state = DEV_STATE_NOT_OPER;
 518                 ret = online_store_recog_and_online(cdev);
 519                 if (ret)
 520                         return ret;
 521         }
 522         return 0;
 523 }
 524
 525 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 526                              const char *buf, size_t count)
 527 {
 528         struct ccw_device *cdev = to_ccwdev(dev);
 529         int force, ret;
 530         unsigned long i;
 531
 532         if ((cdev->private->state != DEV_STATE_OFFLINE &&
 533              cdev->private->state != DEV_STATE_ONLINE &&
 534              cdev->private->state != DEV_STATE_BOXED &&
 535              cdev->private->state != DEV_STATE_DISCONNECTED) ||
 536             atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 537                 return -EAGAIN;
 538
 539         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 540                 atomic_set(&cdev->private->onoff, 0);
 541                 return -EINVAL;
 542         }
 543         if (!strncmp(buf, "force\n", count)) {
 544                 force = 1;
 545                 i = 1;
 546                 ret = 0;
 547         } else {
 548                 force = 0;
 549                 ret = strict_strtoul(buf, 16, &i);
 550         }
 551         if (ret)
 552                 goto out;
 553         switch (i) {
 554         case 0:
 555                 ret = online_store_handle_offline(cdev);
 556                 break;
 557         case 1:
 558                 ret = online_store_handle_online(cdev, force);
 559                 break;
 560         default:
 561                 ret = -EINVAL;
 562         }
 563 out:
 564         if (cdev->drv)
 565                 module_put(cdev->drv->owner);
 566         atomic_set(&cdev->private->onoff, 0);
 567         return (ret < 0) ? ret : count;
 568 }
 569
 570 static ssize_t
 571 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 572 {
 573         struct ccw_device *cdev = to_ccwdev(dev);
 574         struct subchannel *sch;
 575
 576         if (ccw_device_is_orphan(cdev))
 577                 return sprintf(buf, "no device\n");
 578         switch (cdev->private->state) {
 579         case DEV_STATE_BOXED:
 580                 return sprintf(buf, "boxed\n");
 581         case DEV_STATE_DISCONNECTED:
 582         case DEV_STATE_DISCONNECTED_SENSE_ID:
 583         case DEV_STATE_NOT_OPER:
 584                 sch = to_subchannel(dev->parent);
 585                 if (!sch->lpm)
 586                         return sprintf(buf, "no path\n");
 587                 else
 588                         return sprintf(buf, "no device\n");
 589         default:
 590                 /* All other states considered fine. */
 591                 return sprintf(buf, "good\n");
 592         }
 593 }
 594
 595 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 596 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 597 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 598 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 599 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 600 static DEVICE_ATTR(online, 0644, online_show, online_store);
 601 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 602
 603 static struct attribute *io_subchannel_attrs[] = {
 604         &dev_attr_chpids.attr,
 605         &dev_attr_pimpampom.attr,
 606         NULL,
 607 };
 608
 609 static struct attribute_group io_subchannel_attr_group = {
 610         .attrs = io_subchannel_attrs,
 611 };
 612
 613 static struct attribute * ccwdev_attrs[] = {
 614         &dev_attr_devtype.attr,
 615         &dev_attr_cutype.attr,
 616         &dev_attr_modalias.attr,
 617         &dev_attr_online.attr,
 618         &dev_attr_cmb_enable.attr,
 619         &dev_attr_availability.attr,
 620         NULL,
 621 };
 622
 623 static struct attribute_group ccwdev_attr_group = {
 624         .attrs = ccwdev_attrs,
 625 };
 626
 627 static struct attribute_group *ccwdev_attr_groups[] = {
 628         &ccwdev_attr_group,
 629         NULL,
 630 };
 631
 632 /* this is a simple abstraction for device_register that sets the
 633  * correct bus type and adds the bus specific files */
 634 static int ccw_device_register(struct ccw_device *cdev)
 635 {
 636         struct device *dev = &cdev->dev;
 637         int ret;
 638
 639         dev->bus = &ccw_bus_type;
 640
 641         if ((ret = device_add(dev)))
 642                 return ret;
 643
 644         set_bit(1, &cdev->private->registered);
 645         return ret;
 646 }
 647
 648 struct match_data {
 649         struct ccw_dev_id dev_id;
 650         struct ccw_device * sibling;
 651 };
 652
 653 static int
 654 match_devno(struct device * dev, void * data)
 655 {
 656         struct match_data * d = data;
 657         struct ccw_device * cdev;
 658
 659         cdev = to_ccwdev(dev);
 660         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 661             !ccw_device_is_orphan(cdev) &&
 662             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 663             (cdev != d->sibling))
 664                 return 1;
 665         return 0;
 666 }
 667
 668 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 669                                                      struct ccw_device *sibling)
 670 {
 671         struct device *dev;
 672         struct match_data data;
 673
 674         data.dev_id = *dev_id;
 675         data.sibling = sibling;
 676         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 677
 678         return dev ? to_ccwdev(dev) : NULL;
 679 }
 680
 681 static int match_orphan(struct device *dev, void *data)
 682 {
 683         struct ccw_dev_id *dev_id;
 684         struct ccw_device *cdev;
 685
 686         dev_id = data;
 687         cdev = to_ccwdev(dev);
 688         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 689 }
 690
 691 static struct ccw_device *
 692 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 693                               struct ccw_dev_id *dev_id)
 694 {
 695         struct device *dev;
 696
 697         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 698                                 match_orphan);
 699
 700         return dev ? to_ccwdev(dev) : NULL;
 701 }
 702
 703 void ccw_device_do_unbind_bind(struct work_struct *work)
 704 {
 705         struct ccw_device_private *priv;
 706         struct ccw_device *cdev;
 707         struct subchannel *sch;
 708         int ret;
 709
 710         priv = container_of(work, struct ccw_device_private, kick_work);
 711         cdev = priv->cdev;
 712         sch = to_subchannel(cdev->dev.parent);
 713
 714         if (test_bit(1, &cdev->private->registered)) {
 715                 device_release_driver(&cdev->dev);
 716                 ret = device_attach(&cdev->dev);
 717                 WARN_ON(ret == -ENODEV);
 718         }
 719 }
 720
 721 static void
 722 ccw_device_release(struct device *dev)
 723 {
 724         struct ccw_device *cdev;
 725
 726         cdev = to_ccwdev(dev);
 727         /* Release reference of parent subchannel. */
 728         put_device(cdev->dev.parent);
 729         kfree(cdev->private);
 730         kfree(cdev);
 731 }
 732
 733 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 734 {
 735         struct ccw_device *cdev;
 736
 737         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 738         if (cdev) {
 739                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 740                                         GFP_KERNEL | GFP_DMA);
 741                 if (cdev->private)
 742                         return cdev;
 743         }
 744         kfree(cdev);
 745         return ERR_PTR(-ENOMEM);
 746 }
 747
 748 static int io_subchannel_initialize_dev(struct subchannel *sch,
 749                                         struct ccw_device *cdev)
 750 {
 751         cdev->private->cdev = cdev;
 752         atomic_set(&cdev->private->onoff, 0);
 753         cdev->dev.parent = &sch->dev;
 754         cdev->dev.release = ccw_device_release;
 755         INIT_WORK(&cdev->private->kick_work, NULL);
 756         cdev->dev.groups = ccwdev_attr_groups;
 757         /* Do first half of device_register. */
 758         device_initialize(&cdev->dev);
 759         if (!get_device(&sch->dev)) {
 760                 /* Release reference from device_initialize(). */
 761                 put_device(&cdev->dev);
 762                 return -ENODEV;
 763         }
 764         return 0;
 765 }
 766
 767 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 768 {
 769         struct ccw_device *cdev;
 770         int ret;
 771
 772         cdev = io_subchannel_allocate_dev(sch);
 773         if (!IS_ERR(cdev)) {
 774                 ret = io_subchannel_initialize_dev(sch, cdev);
 775                 if (ret)
 776                         cdev = ERR_PTR(ret);
 777         }
 778         return cdev;
 779 }
 780
 781 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 782
 783 static void sch_attach_device(struct subchannel *sch,
 784                               struct ccw_device *cdev)
 785 {
 786         css_update_ssd_info(sch);
 787         spin_lock_irq(sch->lock);
 788         sch_set_cdev(sch, cdev);
 789         cdev->private->schid = sch->schid;
 790         cdev->ccwlock = sch->lock;
 791         ccw_device_trigger_reprobe(cdev);
 792         spin_unlock_irq(sch->lock);
 793 }
 794
 795 static void sch_attach_disconnected_device(struct subchannel *sch,
 796                                            struct ccw_device *cdev)
 797 {
 798         struct subchannel *other_sch;
 799         int ret;
 800
 801         /* Get reference for new parent. */
 802         if (!get_device(&sch->dev))
 803                 return;
 804         other_sch = to_subchannel(cdev->dev.parent);
 805         /* Note: device_move() changes cdev->dev.parent */
 806         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 807         if (ret) {
 808                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 809                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 810                               cdev->private->dev_id.devno, ret);
 811                 /* Put reference for new parent. */
 812                 put_device(&sch->dev);
 813                 return;
 814         }
 815         sch_set_cdev(other_sch, NULL);
 816         /* No need to keep a subchannel without ccw device around. */
 817         css_sch_device_unregister(other_sch);
 818         sch_attach_device(sch, cdev);
 819         /* Put reference for old parent. */
 820         put_device(&other_sch->dev);
 821 }
 822
 823 static void sch_attach_orphaned_device(struct subchannel *sch,
 824                                        struct ccw_device *cdev)
 825 {
 826         int ret;
 827         struct subchannel *pseudo_sch;
 828
 829         /* Get reference for new parent. */
 830         if (!get_device(&sch->dev))
 831                 return;
 832         pseudo_sch = to_subchannel(cdev->dev.parent);
 833         /*
 834          * Try to move the ccw device to its new subchannel.
 835          * Note: device_move() changes cdev->dev.parent
 836          */
 837         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 838         if (ret) {
 839                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 840                               "failed (ret=%d)!\n",
 841                               cdev->private->dev_id.ssid,
 842                               cdev->private->dev_id.devno, ret);
 843                 /* Put reference for new parent. */
 844                 put_device(&sch->dev);
 845                 return;
 846         }
 847         sch_attach_device(sch, cdev);
 848         /* Put reference on pseudo subchannel. */
 849         put_device(&pseudo_sch->dev);
 850 }
 851
 852 static void sch_create_and_recog_new_device(struct subchannel *sch)
 853 {
 854         struct ccw_device *cdev;
 855
 856         /* Need to allocate a new ccw device. */
 857         cdev = io_subchannel_create_ccwdev(sch);
 858         if (IS_ERR(cdev)) {
 859                 /* OK, we did everything we could... */
 860                 css_sch_device_unregister(sch);
 861                 return;
 862         }
 863         spin_lock_irq(sch->lock);
 864         sch_set_cdev(sch, cdev);
 865         spin_unlock_irq(sch->lock);
 866         /* Start recognition for the new ccw device. */
 867         if (io_subchannel_recog(cdev, sch)) {
 868                 spin_lock_irq(sch->lock);
 869                 sch_set_cdev(sch, NULL);
 870                 spin_unlock_irq(sch->lock);
 871                 css_sch_device_unregister(sch);
 872                 /* Put reference from io_subchannel_create_ccwdev(). */
 873                 put_device(&sch->dev);
 874                 /* Give up initial reference. */
 875                 put_device(&cdev->dev);
 876         }
 877 }
 878
 879
 880 void ccw_device_move_to_orphanage(struct work_struct *work)
 881 {
 882         struct ccw_device_private *priv;
 883         struct ccw_device *cdev;
 884         struct ccw_device *replacing_cdev;
 885         struct subchannel *sch;
 886         int ret;
 887         struct channel_subsystem *css;
 888         struct ccw_dev_id dev_id;
 889
 890         priv = container_of(work, struct ccw_device_private, kick_work);
 891         cdev = priv->cdev;
 892         sch = to_subchannel(cdev->dev.parent);
 893         css = to_css(sch->dev.parent);
 894         dev_id.devno = sch->schib.pmcw.dev;
 895         dev_id.ssid = sch->schid.ssid;
 896
 897         /* Increase refcount for pseudo subchannel. */
 898         get_device(&css->pseudo_subchannel->dev);
 899         /*
 900          * Move the orphaned ccw device to the orphanage so the replacing
 901          * ccw device can take its place on the subchannel.
 902          * Note: device_move() changes cdev->dev.parent
 903          */
 904         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev,
 905                 DPM_ORDER_NONE);
 906         if (ret) {
 907                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 908                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 909                               cdev->private->dev_id.devno, ret);
 910                 /* Decrease refcount for pseudo subchannel again. */
 911                 put_device(&css->pseudo_subchannel->dev);
 912                 return;
 913         }
 914         cdev->ccwlock = css->pseudo_subchannel->lock;
 915         /*
 916          * Search for the replacing ccw device
 917          * - among the disconnected devices
 918          * - in the orphanage
 919          */
 920         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 921         if (replacing_cdev) {
 922                 sch_attach_disconnected_device(sch, replacing_cdev);
 923                 /* Release reference from get_disc_ccwdev_by_dev_id() */
 924                 put_device(&replacing_cdev->dev);
 925                 /* Release reference of subchannel from old cdev. */
 926                 put_device(&sch->dev);
 927                 return;
 928         }
 929         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 930         if (replacing_cdev) {
 931                 sch_attach_orphaned_device(sch, replacing_cdev);
 932                 /* Release reference from get_orphaned_ccwdev_by_dev_id() */
 933                 put_device(&replacing_cdev->dev);
 934                 /* Release reference of subchannel from old cdev. */
 935                 put_device(&sch->dev);
 936                 return;
 937         }
 938         sch_create_and_recog_new_device(sch);
 939         /* Release reference of subchannel from old cdev. */
 940         put_device(&sch->dev);
 941 }
 942
 943 /*
 944  * Register recognized device.
 945  */
 946 static void
 947 io_subchannel_register(struct work_struct *work)
 948 {
 949         struct ccw_device_private *priv;
 950         struct ccw_device *cdev;
 951         struct subchannel *sch;
 952         int ret;
 953         unsigned long flags;
 954
 955         priv = container_of(work, struct ccw_device_private, kick_work);
 956         cdev = priv->cdev;
 957         sch = to_subchannel(cdev->dev.parent);
 958         /*
 959          * Check if subchannel is still registered. It may have become
 960          * unregistered if a machine check hit us after finishing
 961          * device recognition but before the register work could be
 962          * queued.
 963          */
 964         if (!device_is_registered(&sch->dev))
 965                 goto out_err;
 966         css_update_ssd_info(sch);
 967         /*
 968          * io_subchannel_register() will also be called after device
 969          * recognition has been done for a boxed device (which will already
 970          * be registered). We need to reprobe since we may now have sense id
 971          * information.
 972          */
 973         if (device_is_registered(&cdev->dev)) {
 974                 if (!cdev->drv) {
 975                         ret = device_reprobe(&cdev->dev);
 976                         if (ret)
 977                                 /* We can't do much here. */
 978                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 979                                               " %d for 0.%x.%04x\n", ret,
 980                                               cdev->private->dev_id.ssid,
 981                                               cdev->private->dev_id.devno);
 982                 }
 983                 goto out;
 984         }
 985         /*
 986          * Now we know this subchannel will stay, we can throw
 987          * our delayed uevent.
 988          */
 989         dev_set_uevent_suppress(&sch->dev, 0);
 990         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 991         /* make it known to the system */
 992         ret = ccw_device_register(cdev);
 993         if (ret) {
 994                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 995                               cdev->private->dev_id.ssid,
 996                               cdev->private->dev_id.devno, ret);
 997                 spin_lock_irqsave(sch->lock, flags);
 998                 sch_set_cdev(sch, NULL);
 999                 spin_unlock_irqrestore(sch->lock, flags);
1000                 /* Release initial device reference. */
1001                 put_device(&cdev->dev);
1002                 goto out_err;
1003         }
1004 out:
1005         cdev->private->flags.recog_done = 1;
1006         wake_up(&cdev->private->wait_q);
1007 out_err:
1008         /* Release reference for workqueue processing. */
1009         put_device(&cdev->dev);
1010         if (atomic_dec_and_test(&ccw_device_init_count))
1011                 wake_up(&ccw_device_init_wq);
1012 }
1013
1014 static void ccw_device_call_sch_unregister(struct work_struct *work)
1015 {
1016         struct ccw_device_private *priv;
1017         struct ccw_device *cdev;
1018         struct subchannel *sch;
1019
1020         priv = container_of(work, struct ccw_device_private, kick_work);
1021         cdev = priv->cdev;
1022         /* Get subchannel reference for local processing. */
1023         if (!get_device(cdev->dev.parent))
1024                 return;
1025         sch = to_subchannel(cdev->dev.parent);
1026         css_sch_device_unregister(sch);
1027         /* Reset intparm to zeroes. */
1028         sch->config.intparm = 0;
1029         cio_commit_config(sch);
1030         /* Release cdev reference for workqueue processing.*/
1031         put_device(&cdev->dev);
1032         /* Release subchannel reference for local processing. */
1033         put_device(&sch->dev);
1034 }
1035
1036 void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
1037 {
1038         PREPARE_WORK(&cdev->private->kick_work,
1039                      ccw_device_call_sch_unregister);
1040         queue_work(slow_path_wq, &cdev->private->kick_work);
1041 }
1042
1043 /*
1044  * subchannel recognition done. Called from the state machine.
1045  */
1046 void
1047 io_subchannel_recog_done(struct ccw_device *cdev)
1048 {
1049         if (css_init_done == 0) {
1050                 cdev->private->flags.recog_done = 1;
1051                 return;
1052         }
1053         switch (cdev->private->state) {
1054         case DEV_STATE_BOXED:
1055                 /* Device did not respond in time. */
1056         case DEV_STATE_NOT_OPER:
1057                 cdev->private->flags.recog_done = 1;
1058                 /* Remove device found not operational. */
1059                 if (!get_device(&cdev->dev))
1060                         break;
1061                 ccw_device_schedule_sch_unregister(cdev);
1062                 if (atomic_dec_and_test(&ccw_device_init_count))
1063                         wake_up(&ccw_device_init_wq);
1064                 break;
1065         case DEV_STATE_OFFLINE:
1066                 /*
1067                  * We can't register the device in interrupt context so
1068                  * we schedule a work item.
1069                  */
1070                 if (!get_device(&cdev->dev))
1071                         break;
1072                 PREPARE_WORK(&cdev->private->kick_work,
1073                              io_subchannel_register);
1074                 queue_work(slow_path_wq, &cdev->private->kick_work);
1075                 break;
1076         }
1077 }
1078
1079 static int
1080 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1081 {
1082         int rc;
1083         struct ccw_device_private *priv;
1084
1085         sch_set_cdev(sch, cdev);
1086         cdev->ccwlock = sch->lock;
1087
1088         /* Init private data. */
1089         priv = cdev->private;
1090         priv->dev_id.devno = sch->schib.pmcw.dev;
1091         priv->dev_id.ssid = sch->schid.ssid;
1092         priv->schid = sch->schid;
1093         priv->state = DEV_STATE_NOT_OPER;
1094         INIT_LIST_HEAD(&priv->cmb_list);
1095         init_waitqueue_head(&priv->wait_q);
1096         init_timer(&priv->timer);
1097
1098         /* Set an initial name for the device. */
1099         if (cio_is_console(sch->schid))
1100                 cdev->dev.init_name = cio_get_console_cdev_name(sch);
1101         else
1102                 dev_set_name(&cdev->dev, "0.%x.%04x",
1103                              sch->schid.ssid, sch->schib.pmcw.dev);
1104
1105         /* Increase counter of devices currently in recognition. */
1106         atomic_inc(&ccw_device_init_count);
1107
1108         /* Start async. device sensing. */
1109         spin_lock_irq(sch->lock);
1110         rc = ccw_device_recognition(cdev);
1111         spin_unlock_irq(sch->lock);
1112         if (rc) {
1113                 if (atomic_dec_and_test(&ccw_device_init_count))
1114                         wake_up(&ccw_device_init_wq);
1115         }
1116         return rc;
1117 }
1118
1119 static void ccw_device_move_to_sch(struct work_struct *work)
1120 {
1121         struct ccw_device_private *priv;
1122         int rc;
1123         struct subchannel *sch;
1124         struct ccw_device *cdev;
1125         struct subchannel *former_parent;
1126
1127         priv = container_of(work, struct ccw_device_private, kick_work);
1128         sch = priv->sch;
1129         cdev = priv->cdev;
1130         former_parent = to_subchannel(cdev->dev.parent);
1131         /* Get reference for new parent. */
1132         if (!get_device(&sch->dev))
1133                 return;
1134         mutex_lock(&sch->reg_mutex);
1135         /*
1136          * Try to move the ccw device to its new subchannel.
1137          * Note: device_move() changes cdev->dev.parent
1138          */
1139         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
1140         mutex_unlock(&sch->reg_mutex);
1141         if (rc) {
1142                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1143                               "0.%x.%04x failed (ret=%d)!\n",
1144                               cdev->private->dev_id.ssid,
1145                               cdev->private->dev_id.devno, sch->schid.ssid,
1146                               sch->schid.sch_no, rc);
1147                 css_sch_device_unregister(sch);
1148                 /* Put reference for new parent again. */
1149                 put_device(&sch->dev);
1150                 goto out;
1151         }
1152         if (!sch_is_pseudo_sch(former_parent)) {
1153                 spin_lock_irq(former_parent->lock);
1154                 sch_set_cdev(former_parent, NULL);
1155                 spin_unlock_irq(former_parent->lock);
1156                 css_sch_device_unregister(former_parent);
1157                 /* Reset intparm to zeroes. */
1158                 former_parent->config.intparm = 0;
1159                 cio_commit_config(former_parent);
1160         }
1161         sch_attach_device(sch, cdev);
1162 out:
1163         /* Put reference for old parent. */
1164         put_device(&former_parent->dev);
1165         put_device(&cdev->dev);
1166 }
1167
1168 static void io_subchannel_irq(struct subchannel *sch)
1169 {
1170         struct ccw_device *cdev;
1171
1172         cdev = sch_get_cdev(sch);
1173
1174         CIO_TRACE_EVENT(3, "IRQ");
1175         CIO_TRACE_EVENT(3, dev_name(&sch->dev));
1176         if (cdev)
1177                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1178 }
1179
1180 void io_subchannel_init_config(struct subchannel *sch)
1181 {
1182         memset(&sch->config, 0, sizeof(sch->config));
1183         sch->config.csense = 1;
1184         /* Use subchannel mp mode when there is more than 1 installed CHPID. */
1185         if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
1186                 sch->config.mp = 1;
1187 }
1188
1189 static void io_subchannel_init_fields(struct subchannel *sch)
1190 {
1191         if (cio_is_console(sch->schid))
1192                 sch->opm = 0xff;
1193         else
1194                 sch->opm = chp_get_sch_opm(sch);
1195         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1196         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1197
1198         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1199                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1200                       sch->schib.pmcw.dev, sch->schid.ssid,
1201                       sch->schid.sch_no, sch->schib.pmcw.pim,
1202                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1203
1204         io_subchannel_init_config(sch);
1205 }
1206
1207 static void io_subchannel_do_unreg(struct work_struct *work)
1208 {
1209         struct subchannel *sch;
1210
1211         sch = container_of(work, struct subchannel, work);
1212         css_sch_device_unregister(sch);
1213         /* Reset intparm to zeroes. */
1214         sch->config.intparm = 0;
1215         cio_commit_config(sch);
1216         put_device(&sch->dev);
1217 }
1218
1219 /* Schedule unregister if we have no cdev. */
1220 static void io_subchannel_schedule_removal(struct subchannel *sch)
1221 {
1222         get_device(&sch->dev);
1223         INIT_WORK(&sch->work, io_subchannel_do_unreg);
1224         queue_work(slow_path_wq, &sch->work);
1225 }
1226
1227 /*
1228  * Note: We always return 0 so that we bind to the device even on error.
1229  * This is needed so that our remove function is called on unregister.
1230  */
1231 static int io_subchannel_probe(struct subchannel *sch)
1232 {
1233         struct ccw_device *cdev;
1234         int rc;
1235         unsigned long flags;
1236         struct ccw_dev_id dev_id;
1237
1238         cdev = sch_get_cdev(sch);
1239         if (cdev) {
1240                 rc = sysfs_create_group(&sch->dev.kobj,
1241                                         &io_subchannel_attr_group);
1242                 if (rc)
1243                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1244                                       "attributes for subchannel "
1245                                       "0.%x.%04x (rc=%d)\n",
1246                                       sch->schid.ssid, sch->schid.sch_no, rc);
1247                 /*
1248                  * This subchannel already has an associated ccw_device.
1249                  * Throw the delayed uevent for the subchannel, register
1250                  * the ccw_device and exit. This happens for all early
1251                  * devices, e.g. the console.
1252                  */
1253                 dev_set_uevent_suppress(&sch->dev, 0);
1254                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1255                 cdev->dev.groups = ccwdev_attr_groups;
1256                 device_initialize(&cdev->dev);
1257                 ccw_device_register(cdev);
1258                 /*
1259                  * Check if the device is already online. If it is
1260                  * the reference count needs to be corrected since we
1261                  * didn't obtain a reference in ccw_device_set_online.
1262                  */
1263                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1264                     cdev->private->state != DEV_STATE_OFFLINE &&
1265                     cdev->private->state != DEV_STATE_BOXED)
1266                         get_device(&cdev->dev);
1267                 return 0;
1268         }
1269         io_subchannel_init_fields(sch);
1270         rc = cio_commit_config(sch);
1271         if (rc)
1272                 goto out_schedule;
1273         rc = sysfs_create_group(&sch->dev.kobj,
1274                                 &io_subchannel_attr_group);
1275         if (rc)
1276                 goto out_schedule;
1277         /* Allocate I/O subchannel private data. */
1278         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1279                                GFP_KERNEL | GFP_DMA);
1280         if (!sch->private)
1281                 goto out_err;
1282         /*
1283          * First check if a fitting device may be found amongst the
1284          * disconnected devices or in the orphanage.
1285          */
1286         dev_id.devno = sch->schib.pmcw.dev;
1287         dev_id.ssid = sch->schid.ssid;
1288         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1289         if (!cdev)
1290                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1291                                                      &dev_id);
1292         if (cdev) {
1293                 /*
1294                  * Schedule moving the device until when we have a registered
1295                  * subchannel to move to and succeed the probe. We can
1296                  * unregister later again, when the probe is through.
1297                  */
1298                 cdev->private->sch = sch;
1299                 PREPARE_WORK(&cdev->private->kick_work,
1300                              ccw_device_move_to_sch);
1301                 queue_work(slow_path_wq, &cdev->private->kick_work);
1302                 return 0;
1303         }
1304         cdev = io_subchannel_create_ccwdev(sch);
1305         if (IS_ERR(cdev))
1306                 goto out_err;
1307         rc = io_subchannel_recog(cdev, sch);
1308         if (rc) {
1309                 spin_lock_irqsave(sch->lock, flags);
1310                 io_subchannel_recog_done(cdev);
1311                 spin_unlock_irqrestore(sch->lock, flags);
1312         }
1313         return 0;
1314 out_err:
1315         kfree(sch->private);
1316         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1317 out_schedule:
1318         io_subchannel_schedule_removal(sch);
1319         return 0;
1320 }
1321
1322 static int
1323 io_subchannel_remove (struct subchannel *sch)
1324 {
1325         struct ccw_device *cdev;
1326         unsigned long flags;
1327
1328         cdev = sch_get_cdev(sch);
1329         if (!cdev)
1330                 return 0;
1331         /* Set ccw device to not operational and drop reference. */
1332         spin_lock_irqsave(cdev->ccwlock, flags);
1333         sch_set_cdev(sch, NULL);
1334         cdev->private->state = DEV_STATE_NOT_OPER;
1335         spin_unlock_irqrestore(cdev->ccwlock, flags);
1336         ccw_device_unregister(cdev);
1337         put_device(&cdev->dev);
1338         kfree(sch->private);
1339         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1340         return 0;
1341 }
1342
1343 static int io_subchannel_notify(struct subchannel *sch, int event)
1344 {
1345         struct ccw_device *cdev;
1346
1347         cdev = sch_get_cdev(sch);
1348         if (!cdev)
1349                 return 0;
1350         return ccw_device_notify(cdev, event);
1351 }
1352
1353 static void io_subchannel_verify(struct subchannel *sch)
1354 {
1355         struct ccw_device *cdev;
1356
1357         cdev = sch_get_cdev(sch);
1358         if (cdev)
1359                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1360 }
1361
1362 static int check_for_io_on_path(struct subchannel *sch, int mask)
1363 {
1364         if (cio_update_schib(sch))
1365                 return 0;
1366         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1367                 return 1;
1368         return 0;
1369 }
1370
1371 static void terminate_internal_io(struct subchannel *sch,
1372                                   struct ccw_device *cdev)
1373 {
1374         if (cio_clear(sch)) {
1375                 /* Recheck device in case clear failed. */
1376                 sch->lpm = 0;
1377                 if (cdev->online)
1378                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1379                 else
1380                         css_schedule_eval(sch->schid);
1381                 return;
1382         }
1383         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1384         /* Request retry of internal operation. */
1385         cdev->private->flags.intretry = 1;
1386         /* Call handler. */
1387         if (cdev->handler)
1388                 cdev->handler(cdev, cdev->private->intparm,
1389                               ERR_PTR(-EIO));
1390 }
1391
1392 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1393 {
1394         struct ccw_device *cdev;
1395
1396         cdev = sch_get_cdev(sch);
1397         if (!cdev)
1398                 return;
1399         if (check_for_io_on_path(sch, mask)) {
1400                 if (cdev->private->state == DEV_STATE_ONLINE)
1401                         ccw_device_kill_io(cdev);
1402                 else {
1403                         terminate_internal_io(sch, cdev);
1404                         /* Re-start path verification. */
1405                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1406                 }
1407         } else
1408                 /* trigger path verification. */
1409                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1410
1411 }
1412
1413 static int io_subchannel_chp_event(struct subchannel *sch,
1414                                    struct chp_link *link, int event)
1415 {
1416         int mask;
1417
1418         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1419         if (!mask)
1420                 return 0;
1421         switch (event) {
1422         case CHP_VARY_OFF:
1423                 sch->opm &= ~mask;
1424                 sch->lpm &= ~mask;
1425                 io_subchannel_terminate_path(sch, mask);
1426                 break;
1427         case CHP_VARY_ON:
1428                 sch->opm |= mask;
1429                 sch->lpm |= mask;
1430                 io_subchannel_verify(sch);
1431                 break;
1432         case CHP_OFFLINE:
1433                 if (cio_update_schib(sch))
1434                         return -ENODEV;
1435                 io_subchannel_terminate_path(sch, mask);
1436                 break;
1437         case CHP_ONLINE:
1438                 if (cio_update_schib(sch))
1439                         return -ENODEV;
1440                 sch->lpm |= mask & sch->opm;
1441                 io_subchannel_verify(sch);
1442                 break;
1443         }
1444         return 0;
1445 }
1446
1447 static void
1448 io_subchannel_shutdown(struct subchannel *sch)
1449 {
1450         struct ccw_device *cdev;
1451         int ret;
1452
1453         cdev = sch_get_cdev(sch);
1454
1455         if (cio_is_console(sch->schid))
1456                 return;
1457         if (!sch->schib.pmcw.ena)
1458                 /* Nothing to do. */
1459                 return;
1460         ret = cio_disable_subchannel(sch);
1461         if (ret != -EBUSY)
1462                 /* Subchannel is disabled, we're done. */
1463                 return;
1464         cdev->private->state = DEV_STATE_QUIESCE;
1465         if (cdev->handler)
1466                 cdev->handler(cdev, cdev->private->intparm,
1467                               ERR_PTR(-EIO));
1468         ret = ccw_device_cancel_halt_clear(cdev);
1469         if (ret == -EBUSY) {
1470                 ccw_device_set_timeout(cdev, HZ/10);
1471                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1472         }
1473         cio_disable_subchannel(sch);
1474 }
1475
1476 static int io_subchannel_get_status(struct subchannel *sch)
1477 {
1478         struct schib schib;
1479
1480         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1481                 return CIO_GONE;
1482         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1483                 return CIO_REVALIDATE;
1484         if (!sch->lpm)
1485                 return CIO_NO_PATH;
1486         return CIO_OPER;
1487 }
1488
1489 static int device_is_disconnected(struct ccw_device *cdev)
1490 {
1491         if (!cdev)
1492                 return 0;
1493         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1494                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1495 }
1496
1497 static int recovery_check(struct device *dev, void *data)
1498 {
1499         struct ccw_device *cdev = to_ccwdev(dev);
1500         int *redo = data;
1501
1502         spin_lock_irq(cdev->ccwlock);
1503         switch (cdev->private->state) {
1504         case DEV_STATE_DISCONNECTED:
1505                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1506                               cdev->private->dev_id.ssid,
1507                               cdev->private->dev_id.devno);
1508                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1509                 *redo = 1;
1510                 break;
1511         case DEV_STATE_DISCONNECTED_SENSE_ID:
1512                 *redo = 1;
1513                 break;
1514         }
1515         spin_unlock_irq(cdev->ccwlock);
1516
1517         return 0;
1518 }
1519
1520 static void recovery_work_func(struct work_struct *unused)
1521 {
1522         int redo = 0;
1523
1524         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1525         if (redo) {
1526                 spin_lock_irq(&recovery_lock);
1527                 if (!timer_pending(&recovery_timer)) {
1528                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1529                                 recovery_phase++;
1530                         mod_timer(&recovery_timer, jiffies +
1531                                   recovery_delay[recovery_phase] * HZ);
1532                 }
1533                 spin_unlock_irq(&recovery_lock);
1534         } else
1535                 CIO_MSG_EVENT(4, "recovery: end\n");
1536 }
1537
1538 static DECLARE_WORK(recovery_work, recovery_work_func);
1539
1540 static void recovery_func(unsigned long data)
1541 {
1542         /*
1543          * We can't do our recovery in softirq context and it's not
1544          * performance critical, so we schedule it.
1545          */
1546         schedule_work(&recovery_work);
1547 }
1548
1549 static void ccw_device_schedule_recovery(void)
1550 {
1551         unsigned long flags;
1552
1553         CIO_MSG_EVENT(4, "recovery: schedule\n");
1554         spin_lock_irqsave(&recovery_lock, flags);
1555         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1556                 recovery_phase = 0;
1557                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1558         }
1559         spin_unlock_irqrestore(&recovery_lock, flags);
1560 }
1561
1562 static int purge_fn(struct device *dev, void *data)
1563 {
1564         struct ccw_device *cdev = to_ccwdev(dev);
1565         struct ccw_device_private *priv = cdev->private;
1566         int unreg;
1567
1568         spin_lock_irq(cdev->ccwlock);
1569         unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1570                 (priv->state == DEV_STATE_OFFLINE);
1571         spin_unlock_irq(cdev->ccwlock);
1572         if (!unreg)
1573                 goto out;
1574         if (!get_device(&cdev->dev))
1575                 goto out;
1576         CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1577                       priv->dev_id.devno);
1578         ccw_device_schedule_sch_unregister(cdev);
1579
1580 out:
1581         /* Abort loop in case of pending signal. */
1582         if (signal_pending(current))
1583                 return -EINTR;
1584
1585         return 0;
1586 }
1587
1588 /**
1589  * ccw_purge_blacklisted - purge unused, blacklisted devices
1590  *
1591  * Unregister all ccw devices that are offline and on the blacklist.
1592  */
1593 int ccw_purge_blacklisted(void)
1594 {
1595         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1596         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1597         return 0;
1598 }
1599
1600 static void device_set_disconnected(struct ccw_device *cdev)
1601 {
1602         if (!cdev)
1603                 return;
1604         ccw_device_set_timeout(cdev, 0);
1605         cdev->private->flags.fake_irb = 0;
1606         cdev->private->state = DEV_STATE_DISCONNECTED;
1607         if (cdev->online)
1608                 ccw_device_schedule_recovery();
1609 }
1610
1611 void ccw_device_set_notoper(struct ccw_device *cdev)
1612 {
1613         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1614
1615         CIO_TRACE_EVENT(2, "notoper");
1616         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1617         ccw_device_set_timeout(cdev, 0);
1618         cio_disable_subchannel(sch);
1619         cdev->private->state = DEV_STATE_NOT_OPER;
1620 }
1621
1622 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1623 {
1624         int event, ret, disc;
1625         unsigned long flags;
1626         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1627         struct ccw_device *cdev;
1628
1629         spin_lock_irqsave(sch->lock, flags);
1630         cdev = sch_get_cdev(sch);
1631         disc = device_is_disconnected(cdev);
1632         if (disc && slow) {
1633                 /* Disconnected devices are evaluated directly only.*/
1634                 spin_unlock_irqrestore(sch->lock, flags);
1635                 return 0;
1636         }
1637         /* No interrupt after machine check - kill pending timers. */
1638         if (cdev)
1639                 ccw_device_set_timeout(cdev, 0);
1640         if (!disc && !slow) {
1641                 /* Non-disconnected devices are evaluated on the slow path. */
1642                 spin_unlock_irqrestore(sch->lock, flags);
1643                 return -EAGAIN;
1644         }
1645         event = io_subchannel_get_status(sch);
1646         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1647                       sch->schid.ssid, sch->schid.sch_no, event,
1648                       disc ? "disconnected" : "normal",
1649                       slow ? "slow" : "fast");
1650         /* Analyze subchannel status. */
1651         action = NONE;
1652         switch (event) {
1653         case CIO_NO_PATH:
1654                 if (disc) {
1655                         /* Check if paths have become available. */
1656                         action = REPROBE;
1657                         break;
1658                 }
1659                 /* fall through */
1660         case CIO_GONE:
1661                 /* Ask driver what to do with device. */
1662                 if (io_subchannel_notify(sch, event))
1663                         action = DISC;
1664                 else
1665                         action = UNREGISTER;
1666                 break;
1667         case CIO_REVALIDATE:
1668                 /* Device will be removed, so no notify necessary. */
1669                 if (disc)
1670                         /* Reprobe because immediate unregister might block. */
1671                         action = REPROBE;
1672                 else
1673                         action = UNREGISTER_PROBE;
1674                 break;
1675         case CIO_OPER:
1676                 if (disc)
1677                         /* Get device operational again. */
1678                         action = REPROBE;
1679                 break;
1680         }
1681         /* Perform action. */
1682         ret = 0;
1683         switch (action) {
1684         case UNREGISTER:
1685         case UNREGISTER_PROBE:
1686                 ccw_device_set_notoper(cdev);
1687                 /* Unregister device (will use subchannel lock). */
1688                 spin_unlock_irqrestore(sch->lock, flags);
1689                 css_sch_device_unregister(sch);
1690                 spin_lock_irqsave(sch->lock, flags);
1691
1692                 /* Reset intparm to zeroes. */
1693                 sch->config.intparm = 0;
1694                 cio_commit_config(sch);
1695                 break;
1696         case REPROBE:
1697                 ccw_device_trigger_reprobe(cdev);
1698                 break;
1699         case DISC:
1700                 device_set_disconnected(cdev);
1701                 break;
1702         default:
1703                 break;
1704         }
1705         spin_unlock_irqrestore(sch->lock, flags);
1706         /* Probe if necessary. */
1707         if (action == UNREGISTER_PROBE)
1708                 ret = css_probe_device(sch->schid);
1709
1710         return ret;
1711 }
1712
1713 #ifdef CONFIG_CCW_CONSOLE
1714 static struct ccw_device console_cdev;
1715 static char console_cdev_name[10] = "0.x.xxxx";
1716 static struct ccw_device_private console_private;
1717 static int console_cdev_in_use;
1718
1719 static DEFINE_SPINLOCK(ccw_console_lock);
1720
1721 spinlock_t * cio_get_console_lock(void)
1722 {
1723         return &ccw_console_lock;
1724 }
1725
1726 static int ccw_device_console_enable(struct ccw_device *cdev,
1727                                      struct subchannel *sch)
1728 {
1729         int rc;
1730
1731         /* Attach subchannel private data. */
1732         sch->private = cio_get_console_priv();
1733         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1734         io_subchannel_init_fields(sch);
1735         rc = cio_commit_config(sch);
1736         if (rc)
1737                 return rc;
1738         sch->driver = &io_subchannel_driver;
1739         /* Initialize the ccw_device structure. */
1740         cdev->dev.parent= &sch->dev;
1741         rc = io_subchannel_recog(cdev, sch);
1742         if (rc)
1743                 return rc;
1744
1745         /* Now wait for the async. recognition to come to an end. */
1746         spin_lock_irq(cdev->ccwlock);
1747         while (!dev_fsm_final_state(cdev))
1748                 wait_cons_dev();
1749         rc = -EIO;
1750         if (cdev->private->state != DEV_STATE_OFFLINE)
1751                 goto out_unlock;
1752         ccw_device_online(cdev);
1753         while (!dev_fsm_final_state(cdev))
1754                 wait_cons_dev();
1755         if (cdev->private->state != DEV_STATE_ONLINE)
1756                 goto out_unlock;
1757         rc = 0;
1758 out_unlock:
1759         spin_unlock_irq(cdev->ccwlock);
1760         return 0;
1761 }
1762
1763 struct ccw_device *
1764 ccw_device_probe_console(void)
1765 {
1766         struct subchannel *sch;
1767         int ret;
1768
1769         if (xchg(&console_cdev_in_use, 1) != 0)
1770                 return ERR_PTR(-EBUSY);
1771         sch = cio_probe_console();
1772         if (IS_ERR(sch)) {
1773                 console_cdev_in_use = 0;
1774                 return (void *) sch;
1775         }
1776         memset(&console_cdev, 0, sizeof(struct ccw_device));
1777         memset(&console_private, 0, sizeof(struct ccw_device_private));
1778         console_cdev.private = &console_private;
1779         console_private.cdev = &console_cdev;
1780         ret = ccw_device_console_enable(&console_cdev, sch);
1781         if (ret) {
1782                 cio_release_console();
1783                 console_cdev_in_use = 0;
1784                 return ERR_PTR(ret);
1785         }
1786         console_cdev.online = 1;
1787         return &console_cdev;
1788 }
1789
1790 static int ccw_device_pm_restore(struct device *dev);
1791
1792 int ccw_device_force_console(void)
1793 {
1794         if (!console_cdev_in_use)
1795                 return -ENODEV;
1796         return ccw_device_pm_restore(&console_cdev.dev);
1797 }
1798 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1799
1800 const char *cio_get_console_cdev_name(struct subchannel *sch)
1801 {
1802         snprintf(console_cdev_name, 10, "0.%x.%04x",
1803                  sch->schid.ssid, sch->schib.pmcw.dev);
1804         return (const char *)console_cdev_name;
1805 }
1806 #endif
1807
1808 /*
1809  * get ccw_device matching the busid, but only if owned by cdrv
1810  */
1811 static int
1812 __ccwdev_check_busid(struct device *dev, void *id)
1813 {
1814         char *bus_id;
1815
1816         bus_id = id;
1817
1818         return (strcmp(bus_id, dev_name(dev)) == 0);
1819 }
1820
1821
1822 /**
1823  * get_ccwdev_by_busid() - obtain device from a bus id
1824  * @cdrv: driver the device is owned by
1825  * @bus_id: bus id of the device to be searched
1826  *
1827  * This function searches all devices owned by @cdrv for a device with a bus
1828  * id matching @bus_id.
1829  * Returns:
1830  *  If a match is found, its reference count of the found device is increased
1831  *  and it is returned; else %NULL is returned.
1832  */
1833 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1834                                        const char *bus_id)
1835 {
1836         struct device *dev;
1837         struct device_driver *drv;
1838
1839         drv = get_driver(&cdrv->driver);
1840         if (!drv)
1841                 return NULL;
1842
1843         dev = driver_find_device(drv, NULL, (void *)bus_id,
1844                                  __ccwdev_check_busid);
1845         put_driver(drv);
1846
1847         return dev ? to_ccwdev(dev) : NULL;
1848 }
1849
1850 /************************** device driver handling ************************/
1851
1852 /* This is the implementation of the ccw_driver class. The probe, remove
1853  * and release methods are initially very similar to the device_driver
1854  * implementations, with the difference that they have ccw_device
1855  * arguments.
1856  *
1857  * A ccw driver also contains the information that is needed for
1858  * device matching.
1859  */
1860 static int
1861 ccw_device_probe (struct device *dev)
1862 {
1863         struct ccw_device *cdev = to_ccwdev(dev);
1864         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1865         int ret;
1866
1867         cdev->drv = cdrv; /* to let the driver call _set_online */
1868
1869         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1870
1871         if (ret) {
1872                 cdev->drv = NULL;
1873                 return ret;
1874         }
1875
1876         return 0;
1877 }
1878
1879 static int
1880 ccw_device_remove (struct device *dev)
1881 {
1882         struct ccw_device *cdev = to_ccwdev(dev);
1883         struct ccw_driver *cdrv = cdev->drv;
1884         int ret;
1885
1886         if (cdrv->remove)
1887                 cdrv->remove(cdev);
1888         if (cdev->online) {
1889                 cdev->online = 0;
1890                 spin_lock_irq(cdev->ccwlock);
1891                 ret = ccw_device_offline(cdev);
1892                 spin_unlock_irq(cdev->ccwlock);
1893                 if (ret == 0)
1894                         wait_event(cdev->private->wait_q,
1895                                    dev_fsm_final_state(cdev));
1896                 else
1897                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1898                                       "device 0.%x.%04x\n",
1899                                       ret, cdev->private->dev_id.ssid,
1900                                       cdev->private->dev_id.devno);
1901                 /* Give up reference obtained in ccw_device_set_online(). */
1902                 put_device(&cdev->dev);
1903         }
1904         ccw_device_set_timeout(cdev, 0);
1905         cdev->drv = NULL;
1906         return 0;
1907 }
1908
1909 static void ccw_device_shutdown(struct device *dev)
1910 {
1911         struct ccw_device *cdev;
1912
1913         cdev = to_ccwdev(dev);
1914         if (cdev->drv && cdev->drv->shutdown)
1915                 cdev->drv->shutdown(cdev);
1916         disable_cmf(cdev);
1917 }
1918
1919 static int ccw_device_pm_prepare(struct device *dev)
1920 {
1921         struct ccw_device *cdev = to_ccwdev(dev);
1922
1923         if (work_pending(&cdev->private->kick_work))
1924                 return -EAGAIN;
1925         /* Fail while device is being set online/offline. */
1926         if (atomic_read(&cdev->private->onoff))
1927                 return -EAGAIN;
1928
1929         if (cdev->online && cdev->drv && cdev->drv->prepare)
1930                 return cdev->drv->prepare(cdev);
1931
1932         return 0;
1933 }
1934
1935 static void ccw_device_pm_complete(struct device *dev)
1936 {
1937         struct ccw_device *cdev = to_ccwdev(dev);
1938
1939         if (cdev->online && cdev->drv && cdev->drv->complete)
1940                 cdev->drv->complete(cdev);
1941 }
1942
1943 static int ccw_device_pm_freeze(struct device *dev)
1944 {
1945         struct ccw_device *cdev = to_ccwdev(dev);
1946         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1947         int ret, cm_enabled;
1948
1949         /* Fail suspend while device is in transistional state. */
1950         if (!dev_fsm_final_state(cdev))
1951                 return -EAGAIN;
1952         if (!cdev->online)
1953                 return 0;
1954         if (cdev->drv && cdev->drv->freeze) {
1955                 ret = cdev->drv->freeze(cdev);
1956                 if (ret)
1957                         return ret;
1958         }
1959
1960         spin_lock_irq(sch->lock);
1961         cm_enabled = cdev->private->cmb != NULL;
1962         spin_unlock_irq(sch->lock);
1963         if (cm_enabled) {
1964                 /* Don't have the css write on memory. */
1965                 ret = ccw_set_cmf(cdev, 0);
1966                 if (ret)
1967                         return ret;
1968         }
1969         /* From here on, disallow device driver I/O. */
1970         spin_lock_irq(sch->lock);
1971         ret = cio_disable_subchannel(sch);
1972         spin_unlock_irq(sch->lock);
1973
1974         return ret;
1975 }
1976
1977 static int ccw_device_pm_thaw(struct device *dev)
1978 {
1979         struct ccw_device *cdev = to_ccwdev(dev);
1980         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1981         int ret, cm_enabled;
1982
1983         if (!cdev->online)
1984                 return 0;
1985
1986         spin_lock_irq(sch->lock);
1987         /* Allow device driver I/O again. */
1988         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1989         cm_enabled = cdev->private->cmb != NULL;
1990         spin_unlock_irq(sch->lock);
1991         if (ret)
1992                 return ret;
1993
1994         if (cm_enabled) {
1995                 ret = ccw_set_cmf(cdev, 1);
1996                 if (ret)
1997                         return ret;
1998         }
1999
2000         if (cdev->drv && cdev->drv->thaw)
2001                 ret = cdev->drv->thaw(cdev);
2002
2003         return ret;
2004 }
2005
2006 static void __ccw_device_pm_restore(struct ccw_device *cdev)
2007 {
2008         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2009         int ret;
2010
2011         if (cio_is_console(sch->schid))
2012                 goto out;
2013         /*
2014          * While we were sleeping, devices may have gone or become
2015          * available again. Kick re-detection.
2016          */
2017         spin_lock_irq(sch->lock);
2018         cdev->private->flags.resuming = 1;
2019         ret = ccw_device_recognition(cdev);
2020         spin_unlock_irq(sch->lock);
2021         if (ret) {
2022                 CIO_MSG_EVENT(0, "Couldn't start recognition for device "
2023                               "%s (ret=%d)\n", dev_name(&cdev->dev), ret);
2024                 spin_lock_irq(sch->lock);
2025                 cdev->private->state = DEV_STATE_DISCONNECTED;
2026                 spin_unlock_irq(sch->lock);
2027                 /* notify driver after the resume cb */
2028                 goto out;
2029         }
2030         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
2031                    cdev->private->state == DEV_STATE_DISCONNECTED);
2032
2033 out:
2034         cdev->private->flags.resuming = 0;
2035 }
2036
2037 static int resume_handle_boxed(struct ccw_device *cdev)
2038 {
2039         cdev->private->state = DEV_STATE_BOXED;
2040         if (ccw_device_notify(cdev, CIO_BOXED))
2041                 return 0;
2042         ccw_device_schedule_sch_unregister(cdev);
2043         return -ENODEV;
2044 }
2045
2046 static int resume_handle_disc(struct ccw_device *cdev)
2047 {
2048         cdev->private->state = DEV_STATE_DISCONNECTED;
2049         if (ccw_device_notify(cdev, CIO_GONE))
2050                 return 0;
2051         ccw_device_schedule_sch_unregister(cdev);
2052         return -ENODEV;
2053 }
2054
2055 static int ccw_device_pm_restore(struct device *dev)
2056 {
2057         struct ccw_device *cdev = to_ccwdev(dev);
2058         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2059         int ret = 0, cm_enabled;
2060
2061         __ccw_device_pm_restore(cdev);
2062         spin_lock_irq(sch->lock);
2063         if (cio_is_console(sch->schid)) {
2064                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
2065                 spin_unlock_irq(sch->lock);
2066                 goto out_restore;
2067         }
2068         cdev->private->flags.donotify = 0;
2069         /* check recognition results */
2070         switch (cdev->private->state) {
2071         case DEV_STATE_OFFLINE:
2072                 break;
2073         case DEV_STATE_BOXED:
2074                 ret = resume_handle_boxed(cdev);
2075                 spin_unlock_irq(sch->lock);
2076                 if (ret)
2077                         goto out;
2078                 goto out_restore;
2079         case DEV_STATE_DISCONNECTED:
2080                 goto out_disc_unlock;
2081         default:
2082                 goto out_unreg_unlock;
2083         }
2084         /* check if the device id has changed */
2085         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
2086                 CIO_MSG_EVENT(0, "resume: sch %s: failed (devno changed from "
2087                               "%04x to %04x)\n", dev_name(&sch->dev),
2088                               cdev->private->dev_id.devno,
2089                               sch->schib.pmcw.dev);
2090                 goto out_unreg_unlock;
2091         }
2092         /* check if the device type has changed */
2093         if (!ccw_device_test_sense_data(cdev)) {
2094                 ccw_device_update_sense_data(cdev);
2095                 PREPARE_WORK(&cdev->private->kick_work,
2096                              ccw_device_do_unbind_bind);
2097                 queue_work(ccw_device_work, &cdev->private->kick_work);
2098                 ret = -ENODEV;
2099                 goto out_unlock;
2100         }
2101         if (!cdev->online) {
2102                 ret = 0;
2103                 goto out_unlock;
2104         }
2105         ret = ccw_device_online(cdev);
2106         if (ret)
2107                 goto out_disc_unlock;
2108
2109         cm_enabled = cdev->private->cmb != NULL;
2110         spin_unlock_irq(sch->lock);
2111
2112         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
2113         if (cdev->private->state != DEV_STATE_ONLINE) {
2114                 spin_lock_irq(sch->lock);
2115                 goto out_disc_unlock;
2116         }
2117         if (cm_enabled) {
2118                 ret = ccw_set_cmf(cdev, 1);
2119                 if (ret) {
2120                         CIO_MSG_EVENT(2, "resume: cdev %s: cmf failed "
2121                                       "(rc=%d)\n", dev_name(&cdev->dev), ret);
2122                         ret = 0;
2123                 }
2124         }
2125
2126 out_restore:
2127         if (cdev->online && cdev->drv && cdev->drv->restore)
2128                 ret = cdev->drv->restore(cdev);
2129 out:
2130         return ret;
2131
2132 out_disc_unlock:
2133         ret = resume_handle_disc(cdev);
2134         spin_unlock_irq(sch->lock);
2135         if (ret)
2136                 return ret;
2137         goto out_restore;
2138
2139 out_unreg_unlock:
2140         ccw_device_schedule_sch_unregister(cdev);
2141         ret = -ENODEV;
2142 out_unlock:
2143         spin_unlock_irq(sch->lock);
2144         return ret;
2145 }
2146
2147 static struct dev_pm_ops ccw_pm_ops = {
2148         .prepare = ccw_device_pm_prepare,
2149         .complete = ccw_device_pm_complete,
2150         .freeze = ccw_device_pm_freeze,
2151         .thaw = ccw_device_pm_thaw,
2152         .restore = ccw_device_pm_restore,
2153 };
2154
2155 struct bus_type ccw_bus_type = {
2156         .name   = "ccw",
2157         .match  = ccw_bus_match,
2158         .uevent = ccw_uevent,
2159         .probe  = ccw_device_probe,
2160         .remove = ccw_device_remove,
2161         .shutdown = ccw_device_shutdown,
2162         .pm = &ccw_pm_ops,
2163 };
2164
2165 /**
2166  * ccw_driver_register() - register a ccw driver
2167  * @cdriver: driver to be registered
2168  *
2169  * This function is mainly a wrapper around driver_register().
2170  * Returns:
2171  *   %0 on success and a negative error value on failure.
2172  */
2173 int ccw_driver_register(struct ccw_driver *cdriver)
2174 {
2175         struct device_driver *drv = &cdriver->driver;
2176
2177         drv->bus = &ccw_bus_type;
2178         drv->name = cdriver->name;
2179         drv->owner = cdriver->owner;
2180
2181         return driver_register(drv);
2182 }
2183
2184 /**
2185  * ccw_driver_unregister() - deregister a ccw driver
2186  * @cdriver: driver to be deregistered
2187  *
2188  * This function is mainly a wrapper around driver_unregister().
2189  */
2190 void ccw_driver_unregister(struct ccw_driver *cdriver)
2191 {
2192         driver_unregister(&cdriver->driver);
2193 }
2194
2195 /* Helper func for qdio. */
2196 struct subchannel_id
2197 ccw_device_get_subchannel_id(struct ccw_device *cdev)
2198 {
2199         struct subchannel *sch;
2200
2201         sch = to_subchannel(cdev->dev.parent);
2202         return sch->schid;
2203 }
2204
2205 MODULE_LICENSE("GPL");
2206 EXPORT_SYMBOL(ccw_device_set_online);
2207 EXPORT_SYMBOL(ccw_device_set_offline);
2208 EXPORT_SYMBOL(ccw_driver_register);
2209 EXPORT_SYMBOL(ccw_driver_unregister);
2210 EXPORT_SYMBOL(get_ccwdev_by_busid);
2211 EXPORT_SYMBOL(ccw_bus_type);
2212 EXPORT_SYMBOL(ccw_device_work);
2213 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);