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                         kfree(cdev);
 777                         cdev = ERR_PTR(ret);
 778                 }
 779         }
 780         return cdev;
 781 }
 782
 783 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 784
 785 static void sch_attach_device(struct subchannel *sch,
 786                               struct ccw_device *cdev)
 787 {
 788         css_update_ssd_info(sch);
 789         spin_lock_irq(sch->lock);
 790         sch_set_cdev(sch, cdev);
 791         cdev->private->schid = sch->schid;
 792         cdev->ccwlock = sch->lock;
 793         ccw_device_trigger_reprobe(cdev);
 794         spin_unlock_irq(sch->lock);
 795 }
 796
 797 static void sch_attach_disconnected_device(struct subchannel *sch,
 798                                            struct ccw_device *cdev)
 799 {
 800         struct subchannel *other_sch;
 801         int ret;
 802
 803         /* Get reference for new parent. */
 804         if (!get_device(&sch->dev))
 805                 return;
 806         other_sch = to_subchannel(cdev->dev.parent);
 807         /* Note: device_move() changes cdev->dev.parent */
 808         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 809         if (ret) {
 810                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 811                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 812                               cdev->private->dev_id.devno, ret);
 813                 /* Put reference for new parent. */
 814                 put_device(&sch->dev);
 815                 return;
 816         }
 817         sch_set_cdev(other_sch, NULL);
 818         /* No need to keep a subchannel without ccw device around. */
 819         css_sch_device_unregister(other_sch);
 820         sch_attach_device(sch, cdev);
 821         /* Put reference for old parent. */
 822         put_device(&other_sch->dev);
 823 }
 824
 825 static void sch_attach_orphaned_device(struct subchannel *sch,
 826                                        struct ccw_device *cdev)
 827 {
 828         int ret;
 829         struct subchannel *pseudo_sch;
 830
 831         /* Get reference for new parent. */
 832         if (!get_device(&sch->dev))
 833                 return;
 834         pseudo_sch = to_subchannel(cdev->dev.parent);
 835         /*
 836          * Try to move the ccw device to its new subchannel.
 837          * Note: device_move() changes cdev->dev.parent
 838          */
 839         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 840         if (ret) {
 841                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 842                               "failed (ret=%d)!\n",
 843                               cdev->private->dev_id.ssid,
 844                               cdev->private->dev_id.devno, ret);
 845                 /* Put reference for new parent. */
 846                 put_device(&sch->dev);
 847                 return;
 848         }
 849         sch_attach_device(sch, cdev);
 850         /* Put reference on pseudo subchannel. */
 851         put_device(&pseudo_sch->dev);
 852 }
 853
 854 static void sch_create_and_recog_new_device(struct subchannel *sch)
 855 {
 856         struct ccw_device *cdev;
 857
 858         /* Need to allocate a new ccw device. */
 859         cdev = io_subchannel_create_ccwdev(sch);
 860         if (IS_ERR(cdev)) {
 861                 /* OK, we did everything we could... */
 862                 css_sch_device_unregister(sch);
 863                 return;
 864         }
 865         spin_lock_irq(sch->lock);
 866         sch_set_cdev(sch, cdev);
 867         spin_unlock_irq(sch->lock);
 868         /* Start recognition for the new ccw device. */
 869         if (io_subchannel_recog(cdev, sch)) {
 870                 spin_lock_irq(sch->lock);
 871                 sch_set_cdev(sch, NULL);
 872                 spin_unlock_irq(sch->lock);
 873                 css_sch_device_unregister(sch);
 874                 /* Put reference from io_subchannel_create_ccwdev(). */
 875                 put_device(&sch->dev);
 876                 /* Give up initial reference. */
 877                 put_device(&cdev->dev);
 878         }
 879 }
 880
 881
 882 void ccw_device_move_to_orphanage(struct work_struct *work)
 883 {
 884         struct ccw_device_private *priv;
 885         struct ccw_device *cdev;
 886         struct ccw_device *replacing_cdev;
 887         struct subchannel *sch;
 888         int ret;
 889         struct channel_subsystem *css;
 890         struct ccw_dev_id dev_id;
 891
 892         priv = container_of(work, struct ccw_device_private, kick_work);
 893         cdev = priv->cdev;
 894         sch = to_subchannel(cdev->dev.parent);
 895         css = to_css(sch->dev.parent);
 896         dev_id.devno = sch->schib.pmcw.dev;
 897         dev_id.ssid = sch->schid.ssid;
 898
 899         /* Increase refcount for pseudo subchannel. */
 900         get_device(&css->pseudo_subchannel->dev);
 901         /*
 902          * Move the orphaned ccw device to the orphanage so the replacing
 903          * ccw device can take its place on the subchannel.
 904          * Note: device_move() changes cdev->dev.parent
 905          */
 906         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev,
 907                 DPM_ORDER_NONE);
 908         if (ret) {
 909                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 910                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 911                               cdev->private->dev_id.devno, ret);
 912                 /* Decrease refcount for pseudo subchannel again. */
 913                 put_device(&css->pseudo_subchannel->dev);
 914                 return;
 915         }
 916         cdev->ccwlock = css->pseudo_subchannel->lock;
 917         /*
 918          * Search for the replacing ccw device
 919          * - among the disconnected devices
 920          * - in the orphanage
 921          */
 922         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 923         if (replacing_cdev) {
 924                 sch_attach_disconnected_device(sch, replacing_cdev);
 925                 /* Release reference from get_disc_ccwdev_by_dev_id() */
 926                 put_device(&replacing_cdev->dev);
 927                 /* Release reference of subchannel from old cdev. */
 928                 put_device(&sch->dev);
 929                 return;
 930         }
 931         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 932         if (replacing_cdev) {
 933                 sch_attach_orphaned_device(sch, replacing_cdev);
 934                 /* Release reference from get_orphaned_ccwdev_by_dev_id() */
 935                 put_device(&replacing_cdev->dev);
 936                 /* Release reference of subchannel from old cdev. */
 937                 put_device(&sch->dev);
 938                 return;
 939         }
 940         sch_create_and_recog_new_device(sch);
 941         /* Release reference of subchannel from old cdev. */
 942         put_device(&sch->dev);
 943 }
 944
 945 /*
 946  * Register recognized device.
 947  */
 948 static void
 949 io_subchannel_register(struct work_struct *work)
 950 {
 951         struct ccw_device_private *priv;
 952         struct ccw_device *cdev;
 953         struct subchannel *sch;
 954         int ret;
 955         unsigned long flags;
 956
 957         priv = container_of(work, struct ccw_device_private, kick_work);
 958         cdev = priv->cdev;
 959         sch = to_subchannel(cdev->dev.parent);
 960         /*
 961          * Check if subchannel is still registered. It may have become
 962          * unregistered if a machine check hit us after finishing
 963          * device recognition but before the register work could be
 964          * queued.
 965          */
 966         if (!device_is_registered(&sch->dev))
 967                 goto out_err;
 968         css_update_ssd_info(sch);
 969         /*
 970          * io_subchannel_register() will also be called after device
 971          * recognition has been done for a boxed device (which will already
 972          * be registered). We need to reprobe since we may now have sense id
 973          * information.
 974          */
 975         if (device_is_registered(&cdev->dev)) {
 976                 if (!cdev->drv) {
 977                         ret = device_reprobe(&cdev->dev);
 978                         if (ret)
 979                                 /* We can't do much here. */
 980                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 981                                               " %d for 0.%x.%04x\n", ret,
 982                                               cdev->private->dev_id.ssid,
 983                                               cdev->private->dev_id.devno);
 984                 }
 985                 goto out;
 986         }
 987         /*
 988          * Now we know this subchannel will stay, we can throw
 989          * our delayed uevent.
 990          */
 991         dev_set_uevent_suppress(&sch->dev, 0);
 992         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 993         /* make it known to the system */
 994         ret = ccw_device_register(cdev);
 995         if (ret) {
 996                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 997                               cdev->private->dev_id.ssid,
 998                               cdev->private->dev_id.devno, ret);
 999                 spin_lock_irqsave(sch->lock, flags);
1000                 sch_set_cdev(sch, NULL);
1001                 spin_unlock_irqrestore(sch->lock, flags);
1002                 /* Release initial device reference. */
1003                 put_device(&cdev->dev);
1004                 goto out_err;
1005         }
1006 out:
1007         cdev->private->flags.recog_done = 1;
1008         wake_up(&cdev->private->wait_q);
1009 out_err:
1010         /* Release reference for workqueue processing. */
1011         put_device(&cdev->dev);
1012         if (atomic_dec_and_test(&ccw_device_init_count))
1013                 wake_up(&ccw_device_init_wq);
1014 }
1015
1016 static void ccw_device_call_sch_unregister(struct work_struct *work)
1017 {
1018         struct ccw_device_private *priv;
1019         struct ccw_device *cdev;
1020         struct subchannel *sch;
1021
1022         priv = container_of(work, struct ccw_device_private, kick_work);
1023         cdev = priv->cdev;
1024         /* Get subchannel reference for local processing. */
1025         if (!get_device(cdev->dev.parent))
1026                 return;
1027         sch = to_subchannel(cdev->dev.parent);
1028         css_sch_device_unregister(sch);
1029         /* Reset intparm to zeroes. */
1030         sch->config.intparm = 0;
1031         cio_commit_config(sch);
1032         /* Release cdev reference for workqueue processing.*/
1033         put_device(&cdev->dev);
1034         /* Release subchannel reference for local processing. */
1035         put_device(&sch->dev);
1036 }
1037
1038 void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
1039 {
1040         PREPARE_WORK(&cdev->private->kick_work,
1041                      ccw_device_call_sch_unregister);
1042         queue_work(slow_path_wq, &cdev->private->kick_work);
1043 }
1044
1045 /*
1046  * subchannel recognition done. Called from the state machine.
1047  */
1048 void
1049 io_subchannel_recog_done(struct ccw_device *cdev)
1050 {
1051         if (css_init_done == 0) {
1052                 cdev->private->flags.recog_done = 1;
1053                 return;
1054         }
1055         switch (cdev->private->state) {
1056         case DEV_STATE_BOXED:
1057                 /* Device did not respond in time. */
1058         case DEV_STATE_NOT_OPER:
1059                 cdev->private->flags.recog_done = 1;
1060                 /* Remove device found not operational. */
1061                 if (!get_device(&cdev->dev))
1062                         break;
1063                 ccw_device_schedule_sch_unregister(cdev);
1064                 if (atomic_dec_and_test(&ccw_device_init_count))
1065                         wake_up(&ccw_device_init_wq);
1066                 break;
1067         case DEV_STATE_OFFLINE:
1068                 /*
1069                  * We can't register the device in interrupt context so
1070                  * we schedule a work item.
1071                  */
1072                 if (!get_device(&cdev->dev))
1073                         break;
1074                 PREPARE_WORK(&cdev->private->kick_work,
1075                              io_subchannel_register);
1076                 queue_work(slow_path_wq, &cdev->private->kick_work);
1077                 break;
1078         }
1079 }
1080
1081 static int
1082 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1083 {
1084         int rc;
1085         struct ccw_device_private *priv;
1086
1087         sch_set_cdev(sch, cdev);
1088         cdev->ccwlock = sch->lock;
1089
1090         /* Init private data. */
1091         priv = cdev->private;
1092         priv->dev_id.devno = sch->schib.pmcw.dev;
1093         priv->dev_id.ssid = sch->schid.ssid;
1094         priv->schid = sch->schid;
1095         priv->state = DEV_STATE_NOT_OPER;
1096         INIT_LIST_HEAD(&priv->cmb_list);
1097         init_waitqueue_head(&priv->wait_q);
1098         init_timer(&priv->timer);
1099
1100         /* Set an initial name for the device. */
1101         if (cio_is_console(sch->schid))
1102                 cdev->dev.init_name = cio_get_console_cdev_name(sch);
1103         else
1104                 dev_set_name(&cdev->dev, "0.%x.%04x",
1105                              sch->schid.ssid, sch->schib.pmcw.dev);
1106
1107         /* Increase counter of devices currently in recognition. */
1108         atomic_inc(&ccw_device_init_count);
1109
1110         /* Start async. device sensing. */
1111         spin_lock_irq(sch->lock);
1112         rc = ccw_device_recognition(cdev);
1113         spin_unlock_irq(sch->lock);
1114         if (rc) {
1115                 if (atomic_dec_and_test(&ccw_device_init_count))
1116                         wake_up(&ccw_device_init_wq);
1117         }
1118         return rc;
1119 }
1120
1121 static void ccw_device_move_to_sch(struct work_struct *work)
1122 {
1123         struct ccw_device_private *priv;
1124         int rc;
1125         struct subchannel *sch;
1126         struct ccw_device *cdev;
1127         struct subchannel *former_parent;
1128
1129         priv = container_of(work, struct ccw_device_private, kick_work);
1130         sch = priv->sch;
1131         cdev = priv->cdev;
1132         former_parent = to_subchannel(cdev->dev.parent);
1133         /* Get reference for new parent. */
1134         if (!get_device(&sch->dev))
1135                 return;
1136         mutex_lock(&sch->reg_mutex);
1137         /*
1138          * Try to move the ccw device to its new subchannel.
1139          * Note: device_move() changes cdev->dev.parent
1140          */
1141         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
1142         mutex_unlock(&sch->reg_mutex);
1143         if (rc) {
1144                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1145                               "0.%x.%04x failed (ret=%d)!\n",
1146                               cdev->private->dev_id.ssid,
1147                               cdev->private->dev_id.devno, sch->schid.ssid,
1148                               sch->schid.sch_no, rc);
1149                 css_sch_device_unregister(sch);
1150                 /* Put reference for new parent again. */
1151                 put_device(&sch->dev);
1152                 goto out;
1153         }
1154         if (!sch_is_pseudo_sch(former_parent)) {
1155                 spin_lock_irq(former_parent->lock);
1156                 sch_set_cdev(former_parent, NULL);
1157                 spin_unlock_irq(former_parent->lock);
1158                 css_sch_device_unregister(former_parent);
1159                 /* Reset intparm to zeroes. */
1160                 former_parent->config.intparm = 0;
1161                 cio_commit_config(former_parent);
1162         }
1163         sch_attach_device(sch, cdev);
1164 out:
1165         /* Put reference for old parent. */
1166         put_device(&former_parent->dev);
1167         put_device(&cdev->dev);
1168 }
1169
1170 static void io_subchannel_irq(struct subchannel *sch)
1171 {
1172         struct ccw_device *cdev;
1173
1174         cdev = sch_get_cdev(sch);
1175
1176         CIO_TRACE_EVENT(3, "IRQ");
1177         CIO_TRACE_EVENT(3, dev_name(&sch->dev));
1178         if (cdev)
1179                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1180 }
1181
1182 void io_subchannel_init_config(struct subchannel *sch)
1183 {
1184         memset(&sch->config, 0, sizeof(sch->config));
1185         sch->config.csense = 1;
1186         /* Use subchannel mp mode when there is more than 1 installed CHPID. */
1187         if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
1188                 sch->config.mp = 1;
1189 }
1190
1191 static void io_subchannel_init_fields(struct subchannel *sch)
1192 {
1193         if (cio_is_console(sch->schid))
1194                 sch->opm = 0xff;
1195         else
1196                 sch->opm = chp_get_sch_opm(sch);
1197         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1198         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1199
1200         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1201                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1202                       sch->schib.pmcw.dev, sch->schid.ssid,
1203                       sch->schid.sch_no, sch->schib.pmcw.pim,
1204                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1205
1206         io_subchannel_init_config(sch);
1207 }
1208
1209 static void io_subchannel_do_unreg(struct work_struct *work)
1210 {
1211         struct subchannel *sch;
1212
1213         sch = container_of(work, struct subchannel, work);
1214         css_sch_device_unregister(sch);
1215         /* Reset intparm to zeroes. */
1216         sch->config.intparm = 0;
1217         cio_commit_config(sch);
1218         put_device(&sch->dev);
1219 }
1220
1221 /* Schedule unregister if we have no cdev. */
1222 static void io_subchannel_schedule_removal(struct subchannel *sch)
1223 {
1224         get_device(&sch->dev);
1225         INIT_WORK(&sch->work, io_subchannel_do_unreg);
1226         queue_work(slow_path_wq, &sch->work);
1227 }
1228
1229 /*
1230  * Note: We always return 0 so that we bind to the device even on error.
1231  * This is needed so that our remove function is called on unregister.
1232  */
1233 static int io_subchannel_probe(struct subchannel *sch)
1234 {
1235         struct ccw_device *cdev;
1236         int rc;
1237         unsigned long flags;
1238         struct ccw_dev_id dev_id;
1239
1240         cdev = sch_get_cdev(sch);
1241         if (cdev) {
1242                 rc = sysfs_create_group(&sch->dev.kobj,
1243                                         &io_subchannel_attr_group);
1244                 if (rc)
1245                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1246                                       "attributes for subchannel "
1247                                       "0.%x.%04x (rc=%d)\n",
1248                                       sch->schid.ssid, sch->schid.sch_no, rc);
1249                 /*
1250                  * This subchannel already has an associated ccw_device.
1251                  * Throw the delayed uevent for the subchannel, register
1252                  * the ccw_device and exit. This happens for all early
1253                  * devices, e.g. the console.
1254                  */
1255                 dev_set_uevent_suppress(&sch->dev, 0);
1256                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1257                 cdev->dev.groups = ccwdev_attr_groups;
1258                 device_initialize(&cdev->dev);
1259                 ccw_device_register(cdev);
1260                 /*
1261                  * Check if the device is already online. If it is
1262                  * the reference count needs to be corrected since we
1263                  * didn't obtain a reference in ccw_device_set_online.
1264                  */
1265                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1266                     cdev->private->state != DEV_STATE_OFFLINE &&
1267                     cdev->private->state != DEV_STATE_BOXED)
1268                         get_device(&cdev->dev);
1269                 return 0;
1270         }
1271         io_subchannel_init_fields(sch);
1272         rc = cio_commit_config(sch);
1273         if (rc)
1274                 goto out_schedule;
1275         rc = sysfs_create_group(&sch->dev.kobj,
1276                                 &io_subchannel_attr_group);
1277         if (rc)
1278                 goto out_schedule;
1279         /* Allocate I/O subchannel private data. */
1280         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1281                                GFP_KERNEL | GFP_DMA);
1282         if (!sch->private)
1283                 goto out_err;
1284         /*
1285          * First check if a fitting device may be found amongst the
1286          * disconnected devices or in the orphanage.
1287          */
1288         dev_id.devno = sch->schib.pmcw.dev;
1289         dev_id.ssid = sch->schid.ssid;
1290         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1291         if (!cdev)
1292                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1293                                                      &dev_id);
1294         if (cdev) {
1295                 /*
1296                  * Schedule moving the device until when we have a registered
1297                  * subchannel to move to and succeed the probe. We can
1298                  * unregister later again, when the probe is through.
1299                  */
1300                 cdev->private->sch = sch;
1301                 PREPARE_WORK(&cdev->private->kick_work,
1302                              ccw_device_move_to_sch);
1303                 queue_work(slow_path_wq, &cdev->private->kick_work);
1304                 return 0;
1305         }
1306         cdev = io_subchannel_create_ccwdev(sch);
1307         if (IS_ERR(cdev))
1308                 goto out_err;
1309         rc = io_subchannel_recog(cdev, sch);
1310         if (rc) {
1311                 spin_lock_irqsave(sch->lock, flags);
1312                 io_subchannel_recog_done(cdev);
1313                 spin_unlock_irqrestore(sch->lock, flags);
1314         }
1315         return 0;
1316 out_err:
1317         kfree(sch->private);
1318         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1319 out_schedule:
1320         io_subchannel_schedule_removal(sch);
1321         return 0;
1322 }
1323
1324 static int
1325 io_subchannel_remove (struct subchannel *sch)
1326 {
1327         struct ccw_device *cdev;
1328         unsigned long flags;
1329
1330         cdev = sch_get_cdev(sch);
1331         if (!cdev)
1332                 return 0;
1333         /* Set ccw device to not operational and drop reference. */
1334         spin_lock_irqsave(cdev->ccwlock, flags);
1335         sch_set_cdev(sch, NULL);
1336         cdev->private->state = DEV_STATE_NOT_OPER;
1337         spin_unlock_irqrestore(cdev->ccwlock, flags);
1338         ccw_device_unregister(cdev);
1339         put_device(&cdev->dev);
1340         kfree(sch->private);
1341         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1342         return 0;
1343 }
1344
1345 static int io_subchannel_notify(struct subchannel *sch, int event)
1346 {
1347         struct ccw_device *cdev;
1348
1349         cdev = sch_get_cdev(sch);
1350         if (!cdev)
1351                 return 0;
1352         return ccw_device_notify(cdev, event);
1353 }
1354
1355 static void io_subchannel_verify(struct subchannel *sch)
1356 {
1357         struct ccw_device *cdev;
1358
1359         cdev = sch_get_cdev(sch);
1360         if (cdev)
1361                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1362 }
1363
1364 static int check_for_io_on_path(struct subchannel *sch, int mask)
1365 {
1366         if (cio_update_schib(sch))
1367                 return 0;
1368         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1369                 return 1;
1370         return 0;
1371 }
1372
1373 static void terminate_internal_io(struct subchannel *sch,
1374                                   struct ccw_device *cdev)
1375 {
1376         if (cio_clear(sch)) {
1377                 /* Recheck device in case clear failed. */
1378                 sch->lpm = 0;
1379                 if (cdev->online)
1380                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1381                 else
1382                         css_schedule_eval(sch->schid);
1383                 return;
1384         }
1385         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1386         /* Request retry of internal operation. */
1387         cdev->private->flags.intretry = 1;
1388         /* Call handler. */
1389         if (cdev->handler)
1390                 cdev->handler(cdev, cdev->private->intparm,
1391                               ERR_PTR(-EIO));
1392 }
1393
1394 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1395 {
1396         struct ccw_device *cdev;
1397
1398         cdev = sch_get_cdev(sch);
1399         if (!cdev)
1400                 return;
1401         if (check_for_io_on_path(sch, mask)) {
1402                 if (cdev->private->state == DEV_STATE_ONLINE)
1403                         ccw_device_kill_io(cdev);
1404                 else {
1405                         terminate_internal_io(sch, cdev);
1406                         /* Re-start path verification. */
1407                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1408                 }
1409         } else
1410                 /* trigger path verification. */
1411                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1412
1413 }
1414
1415 static int io_subchannel_chp_event(struct subchannel *sch,
1416                                    struct chp_link *link, int event)
1417 {
1418         int mask;
1419
1420         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1421         if (!mask)
1422                 return 0;
1423         switch (event) {
1424         case CHP_VARY_OFF:
1425                 sch->opm &= ~mask;
1426                 sch->lpm &= ~mask;
1427                 io_subchannel_terminate_path(sch, mask);
1428                 break;
1429         case CHP_VARY_ON:
1430                 sch->opm |= mask;
1431                 sch->lpm |= mask;
1432                 io_subchannel_verify(sch);
1433                 break;
1434         case CHP_OFFLINE:
1435                 if (cio_update_schib(sch))
1436                         return -ENODEV;
1437                 io_subchannel_terminate_path(sch, mask);
1438                 break;
1439         case CHP_ONLINE:
1440                 if (cio_update_schib(sch))
1441                         return -ENODEV;
1442                 sch->lpm |= mask & sch->opm;
1443                 io_subchannel_verify(sch);
1444                 break;
1445         }
1446         return 0;
1447 }
1448
1449 static void
1450 io_subchannel_shutdown(struct subchannel *sch)
1451 {
1452         struct ccw_device *cdev;
1453         int ret;
1454
1455         cdev = sch_get_cdev(sch);
1456
1457         if (cio_is_console(sch->schid))
1458                 return;
1459         if (!sch->schib.pmcw.ena)
1460                 /* Nothing to do. */
1461                 return;
1462         ret = cio_disable_subchannel(sch);
1463         if (ret != -EBUSY)
1464                 /* Subchannel is disabled, we're done. */
1465                 return;
1466         cdev->private->state = DEV_STATE_QUIESCE;
1467         if (cdev->handler)
1468                 cdev->handler(cdev, cdev->private->intparm,
1469                               ERR_PTR(-EIO));
1470         ret = ccw_device_cancel_halt_clear(cdev);
1471         if (ret == -EBUSY) {
1472                 ccw_device_set_timeout(cdev, HZ/10);
1473                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1474         }
1475         cio_disable_subchannel(sch);
1476 }
1477
1478 static int io_subchannel_get_status(struct subchannel *sch)
1479 {
1480         struct schib schib;
1481
1482         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1483                 return CIO_GONE;
1484         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1485                 return CIO_REVALIDATE;
1486         if (!sch->lpm)
1487                 return CIO_NO_PATH;
1488         return CIO_OPER;
1489 }
1490
1491 static int device_is_disconnected(struct ccw_device *cdev)
1492 {
1493         if (!cdev)
1494                 return 0;
1495         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1496                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1497 }
1498
1499 static int recovery_check(struct device *dev, void *data)
1500 {
1501         struct ccw_device *cdev = to_ccwdev(dev);
1502         int *redo = data;
1503
1504         spin_lock_irq(cdev->ccwlock);
1505         switch (cdev->private->state) {
1506         case DEV_STATE_DISCONNECTED:
1507                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1508                               cdev->private->dev_id.ssid,
1509                               cdev->private->dev_id.devno);
1510                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1511                 *redo = 1;
1512                 break;
1513         case DEV_STATE_DISCONNECTED_SENSE_ID:
1514                 *redo = 1;
1515                 break;
1516         }
1517         spin_unlock_irq(cdev->ccwlock);
1518
1519         return 0;
1520 }
1521
1522 static void recovery_work_func(struct work_struct *unused)
1523 {
1524         int redo = 0;
1525
1526         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1527         if (redo) {
1528                 spin_lock_irq(&recovery_lock);
1529                 if (!timer_pending(&recovery_timer)) {
1530                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1531                                 recovery_phase++;
1532                         mod_timer(&recovery_timer, jiffies +
1533                                   recovery_delay[recovery_phase] * HZ);
1534                 }
1535                 spin_unlock_irq(&recovery_lock);
1536         } else
1537                 CIO_MSG_EVENT(4, "recovery: end\n");
1538 }
1539
1540 static DECLARE_WORK(recovery_work, recovery_work_func);
1541
1542 static void recovery_func(unsigned long data)
1543 {
1544         /*
1545          * We can't do our recovery in softirq context and it's not
1546          * performance critical, so we schedule it.
1547          */
1548         schedule_work(&recovery_work);
1549 }
1550
1551 static void ccw_device_schedule_recovery(void)
1552 {
1553         unsigned long flags;
1554
1555         CIO_MSG_EVENT(4, "recovery: schedule\n");
1556         spin_lock_irqsave(&recovery_lock, flags);
1557         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1558                 recovery_phase = 0;
1559                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1560         }
1561         spin_unlock_irqrestore(&recovery_lock, flags);
1562 }
1563
1564 static int purge_fn(struct device *dev, void *data)
1565 {
1566         struct ccw_device *cdev = to_ccwdev(dev);
1567         struct ccw_device_private *priv = cdev->private;
1568         int unreg;
1569
1570         spin_lock_irq(cdev->ccwlock);
1571         unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1572                 (priv->state == DEV_STATE_OFFLINE);
1573         spin_unlock_irq(cdev->ccwlock);
1574         if (!unreg)
1575                 goto out;
1576         if (!get_device(&cdev->dev))
1577                 goto out;
1578         CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1579                       priv->dev_id.devno);
1580         ccw_device_schedule_sch_unregister(cdev);
1581
1582 out:
1583         /* Abort loop in case of pending signal. */
1584         if (signal_pending(current))
1585                 return -EINTR;
1586
1587         return 0;
1588 }
1589
1590 /**
1591  * ccw_purge_blacklisted - purge unused, blacklisted devices
1592  *
1593  * Unregister all ccw devices that are offline and on the blacklist.
1594  */
1595 int ccw_purge_blacklisted(void)
1596 {
1597         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1598         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1599         return 0;
1600 }
1601
1602 static void device_set_disconnected(struct ccw_device *cdev)
1603 {
1604         if (!cdev)
1605                 return;
1606         ccw_device_set_timeout(cdev, 0);
1607         cdev->private->flags.fake_irb = 0;
1608         cdev->private->state = DEV_STATE_DISCONNECTED;
1609         if (cdev->online)
1610                 ccw_device_schedule_recovery();
1611 }
1612
1613 void ccw_device_set_notoper(struct ccw_device *cdev)
1614 {
1615         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1616
1617         CIO_TRACE_EVENT(2, "notoper");
1618         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1619         ccw_device_set_timeout(cdev, 0);
1620         cio_disable_subchannel(sch);
1621         cdev->private->state = DEV_STATE_NOT_OPER;
1622 }
1623
1624 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1625 {
1626         int event, ret, disc;
1627         unsigned long flags;
1628         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1629         struct ccw_device *cdev;
1630
1631         spin_lock_irqsave(sch->lock, flags);
1632         cdev = sch_get_cdev(sch);
1633         disc = device_is_disconnected(cdev);
1634         if (disc && slow) {
1635                 /* Disconnected devices are evaluated directly only.*/
1636                 spin_unlock_irqrestore(sch->lock, flags);
1637                 return 0;
1638         }
1639         /* No interrupt after machine check - kill pending timers. */
1640         if (cdev)
1641                 ccw_device_set_timeout(cdev, 0);
1642         if (!disc && !slow) {
1643                 /* Non-disconnected devices are evaluated on the slow path. */
1644                 spin_unlock_irqrestore(sch->lock, flags);
1645                 return -EAGAIN;
1646         }
1647         event = io_subchannel_get_status(sch);
1648         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1649                       sch->schid.ssid, sch->schid.sch_no, event,
1650                       disc ? "disconnected" : "normal",
1651                       slow ? "slow" : "fast");
1652         /* Analyze subchannel status. */
1653         action = NONE;
1654         switch (event) {
1655         case CIO_NO_PATH:
1656                 if (disc) {
1657                         /* Check if paths have become available. */
1658                         action = REPROBE;
1659                         break;
1660                 }
1661                 /* fall through */
1662         case CIO_GONE:
1663                 /* Ask driver what to do with device. */
1664                 if (io_subchannel_notify(sch, event))
1665                         action = DISC;
1666                 else
1667                         action = UNREGISTER;
1668                 break;
1669         case CIO_REVALIDATE:
1670                 /* Device will be removed, so no notify necessary. */
1671                 if (disc)
1672                         /* Reprobe because immediate unregister might block. */
1673                         action = REPROBE;
1674                 else
1675                         action = UNREGISTER_PROBE;
1676                 break;
1677         case CIO_OPER:
1678                 if (disc)
1679                         /* Get device operational again. */
1680                         action = REPROBE;
1681                 break;
1682         }
1683         /* Perform action. */
1684         ret = 0;
1685         switch (action) {
1686         case UNREGISTER:
1687         case UNREGISTER_PROBE:
1688                 ccw_device_set_notoper(cdev);
1689                 /* Unregister device (will use subchannel lock). */
1690                 spin_unlock_irqrestore(sch->lock, flags);
1691                 css_sch_device_unregister(sch);
1692                 spin_lock_irqsave(sch->lock, flags);
1693
1694                 /* Reset intparm to zeroes. */
1695                 sch->config.intparm = 0;
1696                 cio_commit_config(sch);
1697                 break;
1698         case REPROBE:
1699                 ccw_device_trigger_reprobe(cdev);
1700                 break;
1701         case DISC:
1702                 device_set_disconnected(cdev);
1703                 break;
1704         default:
1705                 break;
1706         }
1707         spin_unlock_irqrestore(sch->lock, flags);
1708         /* Probe if necessary. */
1709         if (action == UNREGISTER_PROBE)
1710                 ret = css_probe_device(sch->schid);
1711
1712         return ret;
1713 }
1714
1715 #ifdef CONFIG_CCW_CONSOLE
1716 static struct ccw_device console_cdev;
1717 static char console_cdev_name[10] = "0.x.xxxx";
1718 static struct ccw_device_private console_private;
1719 static int console_cdev_in_use;
1720
1721 static DEFINE_SPINLOCK(ccw_console_lock);
1722
1723 spinlock_t * cio_get_console_lock(void)
1724 {
1725         return &ccw_console_lock;
1726 }
1727
1728 static int ccw_device_console_enable(struct ccw_device *cdev,
1729                                      struct subchannel *sch)
1730 {
1731         int rc;
1732
1733         /* Attach subchannel private data. */
1734         sch->private = cio_get_console_priv();
1735         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1736         io_subchannel_init_fields(sch);
1737         rc = cio_commit_config(sch);
1738         if (rc)
1739                 return rc;
1740         sch->driver = &io_subchannel_driver;
1741         /* Initialize the ccw_device structure. */
1742         cdev->dev.parent= &sch->dev;
1743         rc = io_subchannel_recog(cdev, sch);
1744         if (rc)
1745                 return rc;
1746
1747         /* Now wait for the async. recognition to come to an end. */
1748         spin_lock_irq(cdev->ccwlock);
1749         while (!dev_fsm_final_state(cdev))
1750                 wait_cons_dev();
1751         rc = -EIO;
1752         if (cdev->private->state != DEV_STATE_OFFLINE)
1753                 goto out_unlock;
1754         ccw_device_online(cdev);
1755         while (!dev_fsm_final_state(cdev))
1756                 wait_cons_dev();
1757         if (cdev->private->state != DEV_STATE_ONLINE)
1758                 goto out_unlock;
1759         rc = 0;
1760 out_unlock:
1761         spin_unlock_irq(cdev->ccwlock);
1762         return 0;
1763 }
1764
1765 struct ccw_device *
1766 ccw_device_probe_console(void)
1767 {
1768         struct subchannel *sch;
1769         int ret;
1770
1771         if (xchg(&console_cdev_in_use, 1) != 0)
1772                 return ERR_PTR(-EBUSY);
1773         sch = cio_probe_console();
1774         if (IS_ERR(sch)) {
1775                 console_cdev_in_use = 0;
1776                 return (void *) sch;
1777         }
1778         memset(&console_cdev, 0, sizeof(struct ccw_device));
1779         memset(&console_private, 0, sizeof(struct ccw_device_private));
1780         console_cdev.private = &console_private;
1781         console_private.cdev = &console_cdev;
1782         ret = ccw_device_console_enable(&console_cdev, sch);
1783         if (ret) {
1784                 cio_release_console();
1785                 console_cdev_in_use = 0;
1786                 return ERR_PTR(ret);
1787         }
1788         console_cdev.online = 1;
1789         return &console_cdev;
1790 }
1791
1792 static int ccw_device_pm_restore(struct device *dev);
1793
1794 int ccw_device_force_console(void)
1795 {
1796         if (!console_cdev_in_use)
1797                 return -ENODEV;
1798         return ccw_device_pm_restore(&console_cdev.dev);
1799 }
1800 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1801
1802 const char *cio_get_console_cdev_name(struct subchannel *sch)
1803 {
1804         snprintf(console_cdev_name, 10, "0.%x.%04x",
1805                  sch->schid.ssid, sch->schib.pmcw.dev);
1806         return (const char *)console_cdev_name;
1807 }
1808 #endif
1809
1810 /*
1811  * get ccw_device matching the busid, but only if owned by cdrv
1812  */
1813 static int
1814 __ccwdev_check_busid(struct device *dev, void *id)
1815 {
1816         char *bus_id;
1817
1818         bus_id = id;
1819
1820         return (strcmp(bus_id, dev_name(dev)) == 0);
1821 }
1822
1823
1824 /**
1825  * get_ccwdev_by_busid() - obtain device from a bus id
1826  * @cdrv: driver the device is owned by
1827  * @bus_id: bus id of the device to be searched
1828  *
1829  * This function searches all devices owned by @cdrv for a device with a bus
1830  * id matching @bus_id.
1831  * Returns:
1832  *  If a match is found, its reference count of the found device is increased
1833  *  and it is returned; else %NULL is returned.
1834  */
1835 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1836                                        const char *bus_id)
1837 {
1838         struct device *dev;
1839         struct device_driver *drv;
1840
1841         drv = get_driver(&cdrv->driver);
1842         if (!drv)
1843                 return NULL;
1844
1845         dev = driver_find_device(drv, NULL, (void *)bus_id,
1846                                  __ccwdev_check_busid);
1847         put_driver(drv);
1848
1849         return dev ? to_ccwdev(dev) : NULL;
1850 }
1851
1852 /************************** device driver handling ************************/
1853
1854 /* This is the implementation of the ccw_driver class. The probe, remove
1855  * and release methods are initially very similar to the device_driver
1856  * implementations, with the difference that they have ccw_device
1857  * arguments.
1858  *
1859  * A ccw driver also contains the information that is needed for
1860  * device matching.
1861  */
1862 static int
1863 ccw_device_probe (struct device *dev)
1864 {
1865         struct ccw_device *cdev = to_ccwdev(dev);
1866         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1867         int ret;
1868
1869         cdev->drv = cdrv; /* to let the driver call _set_online */
1870
1871         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1872
1873         if (ret) {
1874                 cdev->drv = NULL;
1875                 return ret;
1876         }
1877
1878         return 0;
1879 }
1880
1881 static int
1882 ccw_device_remove (struct device *dev)
1883 {
1884         struct ccw_device *cdev = to_ccwdev(dev);
1885         struct ccw_driver *cdrv = cdev->drv;
1886         int ret;
1887
1888         if (cdrv->remove)
1889                 cdrv->remove(cdev);
1890         if (cdev->online) {
1891                 cdev->online = 0;
1892                 spin_lock_irq(cdev->ccwlock);
1893                 ret = ccw_device_offline(cdev);
1894                 spin_unlock_irq(cdev->ccwlock);
1895                 if (ret == 0)
1896                         wait_event(cdev->private->wait_q,
1897                                    dev_fsm_final_state(cdev));
1898                 else
1899                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1900                                       "device 0.%x.%04x\n",
1901                                       ret, cdev->private->dev_id.ssid,
1902                                       cdev->private->dev_id.devno);
1903                 /* Give up reference obtained in ccw_device_set_online(). */
1904                 put_device(&cdev->dev);
1905         }
1906         ccw_device_set_timeout(cdev, 0);
1907         cdev->drv = NULL;
1908         return 0;
1909 }
1910
1911 static void ccw_device_shutdown(struct device *dev)
1912 {
1913         struct ccw_device *cdev;
1914
1915         cdev = to_ccwdev(dev);
1916         if (cdev->drv && cdev->drv->shutdown)
1917                 cdev->drv->shutdown(cdev);
1918         disable_cmf(cdev);
1919 }
1920
1921 static int ccw_device_pm_prepare(struct device *dev)
1922 {
1923         struct ccw_device *cdev = to_ccwdev(dev);
1924
1925         if (work_pending(&cdev->private->kick_work))
1926                 return -EAGAIN;
1927         /* Fail while device is being set online/offline. */
1928         if (atomic_read(&cdev->private->onoff))
1929                 return -EAGAIN;
1930
1931         if (cdev->online && cdev->drv && cdev->drv->prepare)
1932                 return cdev->drv->prepare(cdev);
1933
1934         return 0;
1935 }
1936
1937 static void ccw_device_pm_complete(struct device *dev)
1938 {
1939         struct ccw_device *cdev = to_ccwdev(dev);
1940
1941         if (cdev->online && cdev->drv && cdev->drv->complete)
1942                 cdev->drv->complete(cdev);
1943 }
1944
1945 static int ccw_device_pm_freeze(struct device *dev)
1946 {
1947         struct ccw_device *cdev = to_ccwdev(dev);
1948         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1949         int ret, cm_enabled;
1950
1951         /* Fail suspend while device is in transistional state. */
1952         if (!dev_fsm_final_state(cdev))
1953                 return -EAGAIN;
1954         if (!cdev->online)
1955                 return 0;
1956         if (cdev->drv && cdev->drv->freeze) {
1957                 ret = cdev->drv->freeze(cdev);
1958                 if (ret)
1959                         return ret;
1960         }
1961
1962         spin_lock_irq(sch->lock);
1963         cm_enabled = cdev->private->cmb != NULL;
1964         spin_unlock_irq(sch->lock);
1965         if (cm_enabled) {
1966                 /* Don't have the css write on memory. */
1967                 ret = ccw_set_cmf(cdev, 0);
1968                 if (ret)
1969                         return ret;
1970         }
1971         /* From here on, disallow device driver I/O. */
1972         spin_lock_irq(sch->lock);
1973         ret = cio_disable_subchannel(sch);
1974         spin_unlock_irq(sch->lock);
1975
1976         return ret;
1977 }
1978
1979 static int ccw_device_pm_thaw(struct device *dev)
1980 {
1981         struct ccw_device *cdev = to_ccwdev(dev);
1982         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1983         int ret, cm_enabled;
1984
1985         if (!cdev->online)
1986                 return 0;
1987
1988         spin_lock_irq(sch->lock);
1989         /* Allow device driver I/O again. */
1990         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1991         cm_enabled = cdev->private->cmb != NULL;
1992         spin_unlock_irq(sch->lock);
1993         if (ret)
1994                 return ret;
1995
1996         if (cm_enabled) {
1997                 ret = ccw_set_cmf(cdev, 1);
1998                 if (ret)
1999                         return ret;
2000         }
2001
2002         if (cdev->drv && cdev->drv->thaw)
2003                 ret = cdev->drv->thaw(cdev);
2004
2005         return ret;
2006 }
2007
2008 static void __ccw_device_pm_restore(struct ccw_device *cdev)
2009 {
2010         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2011         int ret;
2012
2013         if (cio_is_console(sch->schid))
2014                 goto out;
2015         /*
2016          * While we were sleeping, devices may have gone or become
2017          * available again. Kick re-detection.
2018          */
2019         spin_lock_irq(sch->lock);
2020         cdev->private->flags.resuming = 1;
2021         ret = ccw_device_recognition(cdev);
2022         spin_unlock_irq(sch->lock);
2023         if (ret) {
2024                 CIO_MSG_EVENT(0, "Couldn't start recognition for device "
2025                               "%s (ret=%d)\n", dev_name(&cdev->dev), ret);
2026                 spin_lock_irq(sch->lock);
2027                 cdev->private->state = DEV_STATE_DISCONNECTED;
2028                 spin_unlock_irq(sch->lock);
2029                 /* notify driver after the resume cb */
2030                 goto out;
2031         }
2032         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
2033                    cdev->private->state == DEV_STATE_DISCONNECTED);
2034
2035 out:
2036         cdev->private->flags.resuming = 0;
2037 }
2038
2039 static int resume_handle_boxed(struct ccw_device *cdev)
2040 {
2041         cdev->private->state = DEV_STATE_BOXED;
2042         if (ccw_device_notify(cdev, CIO_BOXED))
2043                 return 0;
2044         ccw_device_schedule_sch_unregister(cdev);
2045         return -ENODEV;
2046 }
2047
2048 static int resume_handle_disc(struct ccw_device *cdev)
2049 {
2050         cdev->private->state = DEV_STATE_DISCONNECTED;
2051         if (ccw_device_notify(cdev, CIO_GONE))
2052                 return 0;
2053         ccw_device_schedule_sch_unregister(cdev);
2054         return -ENODEV;
2055 }
2056
2057 static int ccw_device_pm_restore(struct device *dev)
2058 {
2059         struct ccw_device *cdev = to_ccwdev(dev);
2060         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2061         int ret = 0, cm_enabled;
2062
2063         __ccw_device_pm_restore(cdev);
2064         spin_lock_irq(sch->lock);
2065         if (cio_is_console(sch->schid)) {
2066                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
2067                 spin_unlock_irq(sch->lock);
2068                 goto out_restore;
2069         }
2070         cdev->private->flags.donotify = 0;
2071         /* check recognition results */
2072         switch (cdev->private->state) {
2073         case DEV_STATE_OFFLINE:
2074                 break;
2075         case DEV_STATE_BOXED:
2076                 ret = resume_handle_boxed(cdev);
2077                 spin_unlock_irq(sch->lock);
2078                 if (ret)
2079                         goto out;
2080                 goto out_restore;
2081         case DEV_STATE_DISCONNECTED:
2082                 goto out_disc_unlock;
2083         default:
2084                 goto out_unreg_unlock;
2085         }
2086         /* check if the device id has changed */
2087         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
2088                 CIO_MSG_EVENT(0, "resume: sch %s: failed (devno changed from "
2089                               "%04x to %04x)\n", dev_name(&sch->dev),
2090                               cdev->private->dev_id.devno,
2091                               sch->schib.pmcw.dev);
2092                 goto out_unreg_unlock;
2093         }
2094         /* check if the device type has changed */
2095         if (!ccw_device_test_sense_data(cdev)) {
2096                 ccw_device_update_sense_data(cdev);
2097                 PREPARE_WORK(&cdev->private->kick_work,
2098                              ccw_device_do_unbind_bind);
2099                 queue_work(ccw_device_work, &cdev->private->kick_work);
2100                 ret = -ENODEV;
2101                 goto out_unlock;
2102         }
2103         if (!cdev->online) {
2104                 ret = 0;
2105                 goto out_unlock;
2106         }
2107         ret = ccw_device_online(cdev);
2108         if (ret)
2109                 goto out_disc_unlock;
2110
2111         cm_enabled = cdev->private->cmb != NULL;
2112         spin_unlock_irq(sch->lock);
2113
2114         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
2115         if (cdev->private->state != DEV_STATE_ONLINE) {
2116                 spin_lock_irq(sch->lock);
2117                 goto out_disc_unlock;
2118         }
2119         if (cm_enabled) {
2120                 ret = ccw_set_cmf(cdev, 1);
2121                 if (ret) {
2122                         CIO_MSG_EVENT(2, "resume: cdev %s: cmf failed "
2123                                       "(rc=%d)\n", dev_name(&cdev->dev), ret);
2124                         ret = 0;
2125                 }
2126         }
2127
2128 out_restore:
2129         if (cdev->online && cdev->drv && cdev->drv->restore)
2130                 ret = cdev->drv->restore(cdev);
2131 out:
2132         return ret;
2133
2134 out_disc_unlock:
2135         ret = resume_handle_disc(cdev);
2136         spin_unlock_irq(sch->lock);
2137         if (ret)
2138                 return ret;
2139         goto out_restore;
2140
2141 out_unreg_unlock:
2142         ccw_device_schedule_sch_unregister(cdev);
2143         ret = -ENODEV;
2144 out_unlock:
2145         spin_unlock_irq(sch->lock);
2146         return ret;
2147 }
2148
2149 static struct dev_pm_ops ccw_pm_ops = {
2150         .prepare = ccw_device_pm_prepare,
2151         .complete = ccw_device_pm_complete,
2152         .freeze = ccw_device_pm_freeze,
2153         .thaw = ccw_device_pm_thaw,
2154         .restore = ccw_device_pm_restore,
2155 };
2156
2157 struct bus_type ccw_bus_type = {
2158         .name   = "ccw",
2159         .match  = ccw_bus_match,
2160         .uevent = ccw_uevent,
2161         .probe  = ccw_device_probe,
2162         .remove = ccw_device_remove,
2163         .shutdown = ccw_device_shutdown,
2164         .pm = &ccw_pm_ops,
2165 };
2166
2167 /**
2168  * ccw_driver_register() - register a ccw driver
2169  * @cdriver: driver to be registered
2170  *
2171  * This function is mainly a wrapper around driver_register().
2172  * Returns:
2173  *   %0 on success and a negative error value on failure.
2174  */
2175 int ccw_driver_register(struct ccw_driver *cdriver)
2176 {
2177         struct device_driver *drv = &cdriver->driver;
2178
2179         drv->bus = &ccw_bus_type;
2180         drv->name = cdriver->name;
2181         drv->owner = cdriver->owner;
2182
2183         return driver_register(drv);
2184 }
2185
2186 /**
2187  * ccw_driver_unregister() - deregister a ccw driver
2188  * @cdriver: driver to be deregistered
2189  *
2190  * This function is mainly a wrapper around driver_unregister().
2191  */
2192 void ccw_driver_unregister(struct ccw_driver *cdriver)
2193 {
2194         driver_unregister(&cdriver->driver);
2195 }
2196
2197 /* Helper func for qdio. */
2198 struct subchannel_id
2199 ccw_device_get_subchannel_id(struct ccw_device *cdev)
2200 {
2201         struct subchannel *sch;
2202
2203         sch = to_subchannel(cdev->dev.parent);
2204         return sch->schid;
2205 }
2206
2207 MODULE_LICENSE("GPL");
2208 EXPORT_SYMBOL(ccw_device_set_online);
2209 EXPORT_SYMBOL(ccw_device_set_offline);
2210 EXPORT_SYMBOL(ccw_driver_register);
2211 EXPORT_SYMBOL(ccw_driver_unregister);
2212 EXPORT_SYMBOL(get_ccwdev_by_busid);
2213 EXPORT_SYMBOL(ccw_bus_type);
2214 EXPORT_SYMBOL(ccw_device_work);
2215 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);