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                 /* Release reference from device_initialize(). */
 313                 put_device(&cdev->dev);
 314         }
 315 }
 316
 317 static void ccw_device_remove_orphan_cb(struct work_struct *work)
 318 {
 319         struct ccw_device_private *priv;
 320         struct ccw_device *cdev;
 321
 322         priv = container_of(work, struct ccw_device_private, kick_work);
 323         cdev = priv->cdev;
 324         ccw_device_unregister(cdev);
 325         /* Release cdev reference for workqueue processing. */
 326         put_device(&cdev->dev);
 327 }
 328
 329 static void
 330 ccw_device_remove_disconnected(struct ccw_device *cdev)
 331 {
 332         unsigned long flags;
 333
 334         /*
 335          * Forced offline in disconnected state means
 336          * 'throw away device'.
 337          */
 338         if (ccw_device_is_orphan(cdev)) {
 339                 /*
 340                  * Deregister ccw device.
 341                  * Unfortunately, we cannot do this directly from the
 342                  * attribute method.
 343                  */
 344                 /* Get cdev reference for workqueue processing. */
 345                 if (!get_device(&cdev->dev))
 346                         return;
 347                 spin_lock_irqsave(cdev->ccwlock, flags);
 348                 cdev->private->state = DEV_STATE_NOT_OPER;
 349                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 350                 PREPARE_WORK(&cdev->private->kick_work,
 351                                 ccw_device_remove_orphan_cb);
 352                 queue_work(slow_path_wq, &cdev->private->kick_work);
 353         } else
 354                 /* Deregister subchannel, which will kill the ccw device. */
 355                 ccw_device_schedule_sch_unregister(cdev);
 356 }
 357
 358 /**
 359  * ccw_device_set_offline() - disable a ccw device for I/O
 360  * @cdev: target ccw device
 361  *
 362  * This function calls the driver's set_offline() function for @cdev, if
 363  * given, and then disables @cdev.
 364  * Returns:
 365  *   %0 on success and a negative error value on failure.
 366  * Context:
 367  *  enabled, ccw device lock not held
 368  */
 369 int ccw_device_set_offline(struct ccw_device *cdev)
 370 {
 371         int ret;
 372
 373         if (!cdev)
 374                 return -ENODEV;
 375         if (!cdev->online || !cdev->drv)
 376                 return -EINVAL;
 377
 378         if (cdev->drv->set_offline) {
 379                 ret = cdev->drv->set_offline(cdev);
 380                 if (ret != 0)
 381                         return ret;
 382         }
 383         cdev->online = 0;
 384         spin_lock_irq(cdev->ccwlock);
 385         /* Wait until a final state or DISCONNECTED is reached */
 386         while (!dev_fsm_final_state(cdev) &&
 387                cdev->private->state != DEV_STATE_DISCONNECTED) {
 388                 spin_unlock_irq(cdev->ccwlock);
 389                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 390                            cdev->private->state == DEV_STATE_DISCONNECTED));
 391                 spin_lock_irq(cdev->ccwlock);
 392         }
 393         ret = ccw_device_offline(cdev);
 394         if (ret)
 395                 goto error;
 396         spin_unlock_irq(cdev->ccwlock);
 397         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 398                    cdev->private->state == DEV_STATE_DISCONNECTED));
 399         /* Give up reference from ccw_device_set_online(). */
 400         put_device(&cdev->dev);
 401         return 0;
 402
 403 error:
 404         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device 0.%x.%04x\n",
 405                       ret, cdev->private->dev_id.ssid,
 406                       cdev->private->dev_id.devno);
 407         cdev->private->state = DEV_STATE_OFFLINE;
 408         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 409         spin_unlock_irq(cdev->ccwlock);
 410         /* Give up reference from ccw_device_set_online(). */
 411         put_device(&cdev->dev);
 412         return -ENODEV;
 413 }
 414
 415 /**
 416  * ccw_device_set_online() - enable a ccw device for I/O
 417  * @cdev: target ccw device
 418  *
 419  * This function first enables @cdev and then calls the driver's set_online()
 420  * function for @cdev, if given. If set_online() returns an error, @cdev is
 421  * disabled again.
 422  * Returns:
 423  *   %0 on success and a negative error value on failure.
 424  * Context:
 425  *  enabled, ccw device lock not held
 426  */
 427 int ccw_device_set_online(struct ccw_device *cdev)
 428 {
 429         int ret;
 430         int ret2;
 431
 432         if (!cdev)
 433                 return -ENODEV;
 434         if (cdev->online || !cdev->drv)
 435                 return -EINVAL;
 436         /* Hold on to an extra reference while device is online. */
 437         if (!get_device(&cdev->dev))
 438                 return -ENODEV;
 439
 440         spin_lock_irq(cdev->ccwlock);
 441         ret = ccw_device_online(cdev);
 442         spin_unlock_irq(cdev->ccwlock);
 443         if (ret == 0)
 444                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 445         else {
 446                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 447                               "device 0.%x.%04x\n",
 448                               ret, cdev->private->dev_id.ssid,
 449                               cdev->private->dev_id.devno);
 450                 /* Give up online reference since onlining failed. */
 451                 put_device(&cdev->dev);
 452                 return ret;
 453         }
 454         spin_lock_irq(cdev->ccwlock);
 455         /* Check if online processing was successful */
 456         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 457             (cdev->private->state != DEV_STATE_W4SENSE)) {
 458                 spin_unlock_irq(cdev->ccwlock);
 459                 /* Give up online reference since onlining failed. */
 460                 put_device(&cdev->dev);
 461                 return -ENODEV;
 462         }
 463         spin_unlock_irq(cdev->ccwlock);
 464         if (cdev->drv->set_online)
 465                 ret = cdev->drv->set_online(cdev);
 466         if (ret)
 467                 goto rollback;
 468         cdev->online = 1;
 469         return 0;
 470
 471 rollback:
 472         spin_lock_irq(cdev->ccwlock);
 473         /* Wait until a final state or DISCONNECTED is reached */
 474         while (!dev_fsm_final_state(cdev) &&
 475                cdev->private->state != DEV_STATE_DISCONNECTED) {
 476                 spin_unlock_irq(cdev->ccwlock);
 477                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 478                            cdev->private->state == DEV_STATE_DISCONNECTED));
 479                 spin_lock_irq(cdev->ccwlock);
 480         }
 481         ret2 = ccw_device_offline(cdev);
 482         if (ret2)
 483                 goto error;
 484         spin_unlock_irq(cdev->ccwlock);
 485         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 486                    cdev->private->state == DEV_STATE_DISCONNECTED));
 487         /* Give up online reference since onlining failed. */
 488         put_device(&cdev->dev);
 489         return ret;
 490
 491 error:
 492         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 493                       "device 0.%x.%04x\n",
 494                       ret2, cdev->private->dev_id.ssid,
 495                       cdev->private->dev_id.devno);
 496         cdev->private->state = DEV_STATE_OFFLINE;
 497         spin_unlock_irq(cdev->ccwlock);
 498         /* Give up online reference since onlining failed. */
 499         put_device(&cdev->dev);
 500         return ret;
 501 }
 502
 503 static int online_store_handle_offline(struct ccw_device *cdev)
 504 {
 505         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 506                 ccw_device_remove_disconnected(cdev);
 507         else if (cdev->online && cdev->drv && cdev->drv->set_offline)
 508                 return ccw_device_set_offline(cdev);
 509         return 0;
 510 }
 511
 512 static int online_store_recog_and_online(struct ccw_device *cdev)
 513 {
 514         int ret;
 515
 516         /* Do device recognition, if needed. */
 517         if (cdev->private->state == DEV_STATE_BOXED) {
 518                 ret = ccw_device_recognition(cdev);
 519                 if (ret) {
 520                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 521                                       "for device 0.%x.%04x (ret=%d)\n",
 522                                       cdev->private->dev_id.ssid,
 523                                       cdev->private->dev_id.devno, ret);
 524                         return ret;
 525                 }
 526                 wait_event(cdev->private->wait_q,
 527                            cdev->private->flags.recog_done);
 528                 if (cdev->private->state != DEV_STATE_OFFLINE)
 529                         /* recognition failed */
 530                         return -EAGAIN;
 531         }
 532         if (cdev->drv && cdev->drv->set_online)
 533                 ccw_device_set_online(cdev);
 534         return 0;
 535 }
 536
 537 static int online_store_handle_online(struct ccw_device *cdev, int force)
 538 {
 539         int ret;
 540
 541         ret = online_store_recog_and_online(cdev);
 542         if (ret && !force)
 543                 return ret;
 544         if (force && cdev->private->state == DEV_STATE_BOXED) {
 545                 ret = ccw_device_stlck(cdev);
 546                 if (ret)
 547                         return ret;
 548                 if (cdev->id.cu_type == 0)
 549                         cdev->private->state = DEV_STATE_NOT_OPER;
 550                 ret = online_store_recog_and_online(cdev);
 551                 if (ret)
 552                         return ret;
 553         }
 554         return 0;
 555 }
 556
 557 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 558                              const char *buf, size_t count)
 559 {
 560         struct ccw_device *cdev = to_ccwdev(dev);
 561         int force, ret;
 562         unsigned long i;
 563
 564         if ((cdev->private->state != DEV_STATE_OFFLINE &&
 565              cdev->private->state != DEV_STATE_ONLINE &&
 566              cdev->private->state != DEV_STATE_BOXED &&
 567              cdev->private->state != DEV_STATE_DISCONNECTED) ||
 568             atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 569                 return -EAGAIN;
 570
 571         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 572                 atomic_set(&cdev->private->onoff, 0);
 573                 return -EINVAL;
 574         }
 575         if (!strncmp(buf, "force\n", count)) {
 576                 force = 1;
 577                 i = 1;
 578                 ret = 0;
 579         } else {
 580                 force = 0;
 581                 ret = strict_strtoul(buf, 16, &i);
 582         }
 583         if (ret)
 584                 goto out;
 585         switch (i) {
 586         case 0:
 587                 ret = online_store_handle_offline(cdev);
 588                 break;
 589         case 1:
 590                 ret = online_store_handle_online(cdev, force);
 591                 break;
 592         default:
 593                 ret = -EINVAL;
 594         }
 595 out:
 596         if (cdev->drv)
 597                 module_put(cdev->drv->owner);
 598         atomic_set(&cdev->private->onoff, 0);
 599         return (ret < 0) ? ret : count;
 600 }
 601
 602 static ssize_t
 603 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 604 {
 605         struct ccw_device *cdev = to_ccwdev(dev);
 606         struct subchannel *sch;
 607
 608         if (ccw_device_is_orphan(cdev))
 609                 return sprintf(buf, "no device\n");
 610         switch (cdev->private->state) {
 611         case DEV_STATE_BOXED:
 612                 return sprintf(buf, "boxed\n");
 613         case DEV_STATE_DISCONNECTED:
 614         case DEV_STATE_DISCONNECTED_SENSE_ID:
 615         case DEV_STATE_NOT_OPER:
 616                 sch = to_subchannel(dev->parent);
 617                 if (!sch->lpm)
 618                         return sprintf(buf, "no path\n");
 619                 else
 620                         return sprintf(buf, "no device\n");
 621         default:
 622                 /* All other states considered fine. */
 623                 return sprintf(buf, "good\n");
 624         }
 625 }
 626
 627 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 628 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 629 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 630 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 631 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 632 static DEVICE_ATTR(online, 0644, online_show, online_store);
 633 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 634
 635 static struct attribute *io_subchannel_attrs[] = {
 636         &dev_attr_chpids.attr,
 637         &dev_attr_pimpampom.attr,
 638         NULL,
 639 };
 640
 641 static struct attribute_group io_subchannel_attr_group = {
 642         .attrs = io_subchannel_attrs,
 643 };
 644
 645 static struct attribute * ccwdev_attrs[] = {
 646         &dev_attr_devtype.attr,
 647         &dev_attr_cutype.attr,
 648         &dev_attr_modalias.attr,
 649         &dev_attr_online.attr,
 650         &dev_attr_cmb_enable.attr,
 651         &dev_attr_availability.attr,
 652         NULL,
 653 };
 654
 655 static struct attribute_group ccwdev_attr_group = {
 656         .attrs = ccwdev_attrs,
 657 };
 658
 659 static struct attribute_group *ccwdev_attr_groups[] = {
 660         &ccwdev_attr_group,
 661         NULL,
 662 };
 663
 664 /* this is a simple abstraction for device_register that sets the
 665  * correct bus type and adds the bus specific files */
 666 static int ccw_device_register(struct ccw_device *cdev)
 667 {
 668         struct device *dev = &cdev->dev;
 669         int ret;
 670
 671         dev->bus = &ccw_bus_type;
 672
 673         if ((ret = device_add(dev)))
 674                 return ret;
 675
 676         set_bit(1, &cdev->private->registered);
 677         return ret;
 678 }
 679
 680 struct match_data {
 681         struct ccw_dev_id dev_id;
 682         struct ccw_device * sibling;
 683 };
 684
 685 static int
 686 match_devno(struct device * dev, void * data)
 687 {
 688         struct match_data * d = data;
 689         struct ccw_device * cdev;
 690
 691         cdev = to_ccwdev(dev);
 692         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 693             !ccw_device_is_orphan(cdev) &&
 694             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 695             (cdev != d->sibling))
 696                 return 1;
 697         return 0;
 698 }
 699
 700 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 701                                                      struct ccw_device *sibling)
 702 {
 703         struct device *dev;
 704         struct match_data data;
 705
 706         data.dev_id = *dev_id;
 707         data.sibling = sibling;
 708         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 709
 710         return dev ? to_ccwdev(dev) : NULL;
 711 }
 712
 713 static int match_orphan(struct device *dev, void *data)
 714 {
 715         struct ccw_dev_id *dev_id;
 716         struct ccw_device *cdev;
 717
 718         dev_id = data;
 719         cdev = to_ccwdev(dev);
 720         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 721 }
 722
 723 static struct ccw_device *
 724 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 725                               struct ccw_dev_id *dev_id)
 726 {
 727         struct device *dev;
 728
 729         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 730                                 match_orphan);
 731
 732         return dev ? to_ccwdev(dev) : NULL;
 733 }
 734
 735 void ccw_device_do_unbind_bind(struct work_struct *work)
 736 {
 737         struct ccw_device_private *priv;
 738         struct ccw_device *cdev;
 739         struct subchannel *sch;
 740         int ret;
 741
 742         priv = container_of(work, struct ccw_device_private, kick_work);
 743         cdev = priv->cdev;
 744         sch = to_subchannel(cdev->dev.parent);
 745
 746         if (test_bit(1, &cdev->private->registered)) {
 747                 device_release_driver(&cdev->dev);
 748                 ret = device_attach(&cdev->dev);
 749                 WARN_ON(ret == -ENODEV);
 750         }
 751 }
 752
 753 static void
 754 ccw_device_release(struct device *dev)
 755 {
 756         struct ccw_device *cdev;
 757
 758         cdev = to_ccwdev(dev);
 759         /* Release reference of parent subchannel. */
 760         put_device(cdev->dev.parent);
 761         kfree(cdev->private);
 762         kfree(cdev);
 763 }
 764
 765 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 766 {
 767         struct ccw_device *cdev;
 768
 769         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 770         if (cdev) {
 771                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 772                                         GFP_KERNEL | GFP_DMA);
 773                 if (cdev->private)
 774                         return cdev;
 775         }
 776         kfree(cdev);
 777         return ERR_PTR(-ENOMEM);
 778 }
 779
 780 static int io_subchannel_initialize_dev(struct subchannel *sch,
 781                                         struct ccw_device *cdev)
 782 {
 783         cdev->private->cdev = cdev;
 784         atomic_set(&cdev->private->onoff, 0);
 785         cdev->dev.parent = &sch->dev;
 786         cdev->dev.release = ccw_device_release;
 787         INIT_WORK(&cdev->private->kick_work, NULL);
 788         cdev->dev.groups = ccwdev_attr_groups;
 789         /* Do first half of device_register. */
 790         device_initialize(&cdev->dev);
 791         if (!get_device(&sch->dev)) {
 792                 /* Release reference from device_initialize(). */
 793                 put_device(&cdev->dev);
 794                 return -ENODEV;
 795         }
 796         return 0;
 797 }
 798
 799 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 800 {
 801         struct ccw_device *cdev;
 802         int ret;
 803
 804         cdev = io_subchannel_allocate_dev(sch);
 805         if (!IS_ERR(cdev)) {
 806                 ret = io_subchannel_initialize_dev(sch, cdev);
 807                 if (ret)
 808                         cdev = ERR_PTR(ret);
 809         }
 810         return cdev;
 811 }
 812
 813 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 814
 815 static void sch_attach_device(struct subchannel *sch,
 816                               struct ccw_device *cdev)
 817 {
 818         css_update_ssd_info(sch);
 819         spin_lock_irq(sch->lock);
 820         sch_set_cdev(sch, cdev);
 821         cdev->private->schid = sch->schid;
 822         cdev->ccwlock = sch->lock;
 823         ccw_device_trigger_reprobe(cdev);
 824         spin_unlock_irq(sch->lock);
 825 }
 826
 827 static void sch_attach_disconnected_device(struct subchannel *sch,
 828                                            struct ccw_device *cdev)
 829 {
 830         struct subchannel *other_sch;
 831         int ret;
 832
 833         /* Get reference for new parent. */
 834         if (!get_device(&sch->dev))
 835                 return;
 836         other_sch = to_subchannel(cdev->dev.parent);
 837         /* Note: device_move() changes cdev->dev.parent */
 838         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 839         if (ret) {
 840                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 841                               "(ret=%d)!\n", 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_set_cdev(other_sch, NULL);
 848         /* No need to keep a subchannel without ccw device around. */
 849         css_sch_device_unregister(other_sch);
 850         sch_attach_device(sch, cdev);
 851         /* Put reference for old parent. */
 852         put_device(&other_sch->dev);
 853 }
 854
 855 static void sch_attach_orphaned_device(struct subchannel *sch,
 856                                        struct ccw_device *cdev)
 857 {
 858         int ret;
 859         struct subchannel *pseudo_sch;
 860
 861         /* Get reference for new parent. */
 862         if (!get_device(&sch->dev))
 863                 return;
 864         pseudo_sch = to_subchannel(cdev->dev.parent);
 865         /*
 866          * Try to move the ccw device to its new subchannel.
 867          * Note: device_move() changes cdev->dev.parent
 868          */
 869         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 870         if (ret) {
 871                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 872                               "failed (ret=%d)!\n",
 873                               cdev->private->dev_id.ssid,
 874                               cdev->private->dev_id.devno, ret);
 875                 /* Put reference for new parent. */
 876                 put_device(&sch->dev);
 877                 return;
 878         }
 879         sch_attach_device(sch, cdev);
 880         /* Put reference on pseudo subchannel. */
 881         put_device(&pseudo_sch->dev);
 882 }
 883
 884 static void sch_create_and_recog_new_device(struct subchannel *sch)
 885 {
 886         struct ccw_device *cdev;
 887
 888         /* Need to allocate a new ccw device. */
 889         cdev = io_subchannel_create_ccwdev(sch);
 890         if (IS_ERR(cdev)) {
 891                 /* OK, we did everything we could... */
 892                 css_sch_device_unregister(sch);
 893                 return;
 894         }
 895         spin_lock_irq(sch->lock);
 896         sch_set_cdev(sch, cdev);
 897         spin_unlock_irq(sch->lock);
 898         /* Start recognition for the new ccw device. */
 899         if (io_subchannel_recog(cdev, sch)) {
 900                 spin_lock_irq(sch->lock);
 901                 sch_set_cdev(sch, NULL);
 902                 spin_unlock_irq(sch->lock);
 903                 css_sch_device_unregister(sch);
 904                 /* Put reference from io_subchannel_create_ccwdev(). */
 905                 put_device(&sch->dev);
 906                 /* Give up initial reference. */
 907                 put_device(&cdev->dev);
 908         }
 909 }
 910
 911
 912 void ccw_device_move_to_orphanage(struct work_struct *work)
 913 {
 914         struct ccw_device_private *priv;
 915         struct ccw_device *cdev;
 916         struct ccw_device *replacing_cdev;
 917         struct subchannel *sch;
 918         int ret;
 919         struct channel_subsystem *css;
 920         struct ccw_dev_id dev_id;
 921
 922         priv = container_of(work, struct ccw_device_private, kick_work);
 923         cdev = priv->cdev;
 924         sch = to_subchannel(cdev->dev.parent);
 925         css = to_css(sch->dev.parent);
 926         dev_id.devno = sch->schib.pmcw.dev;
 927         dev_id.ssid = sch->schid.ssid;
 928
 929         /* Increase refcount for pseudo subchannel. */
 930         get_device(&css->pseudo_subchannel->dev);
 931         /*
 932          * Move the orphaned ccw device to the orphanage so the replacing
 933          * ccw device can take its place on the subchannel.
 934          * Note: device_move() changes cdev->dev.parent
 935          */
 936         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev,
 937                 DPM_ORDER_NONE);
 938         if (ret) {
 939                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 940                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 941                               cdev->private->dev_id.devno, ret);
 942                 /* Decrease refcount for pseudo subchannel again. */
 943                 put_device(&css->pseudo_subchannel->dev);
 944                 return;
 945         }
 946         cdev->ccwlock = css->pseudo_subchannel->lock;
 947         /*
 948          * Search for the replacing ccw device
 949          * - among the disconnected devices
 950          * - in the orphanage
 951          */
 952         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 953         if (replacing_cdev) {
 954                 sch_attach_disconnected_device(sch, replacing_cdev);
 955                 /* Release reference from get_disc_ccwdev_by_dev_id() */
 956                 put_device(&replacing_cdev->dev);
 957                 /* Release reference of subchannel from old cdev. */
 958                 put_device(&sch->dev);
 959                 return;
 960         }
 961         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 962         if (replacing_cdev) {
 963                 sch_attach_orphaned_device(sch, replacing_cdev);
 964                 /* Release reference from get_orphaned_ccwdev_by_dev_id() */
 965                 put_device(&replacing_cdev->dev);
 966                 /* Release reference of subchannel from old cdev. */
 967                 put_device(&sch->dev);
 968                 return;
 969         }
 970         sch_create_and_recog_new_device(sch);
 971         /* Release reference of subchannel from old cdev. */
 972         put_device(&sch->dev);
 973 }
 974
 975 /*
 976  * Register recognized device.
 977  */
 978 static void
 979 io_subchannel_register(struct work_struct *work)
 980 {
 981         struct ccw_device_private *priv;
 982         struct ccw_device *cdev;
 983         struct subchannel *sch;
 984         int ret;
 985         unsigned long flags;
 986
 987         priv = container_of(work, struct ccw_device_private, kick_work);
 988         cdev = priv->cdev;
 989         sch = to_subchannel(cdev->dev.parent);
 990         /*
 991          * Check if subchannel is still registered. It may have become
 992          * unregistered if a machine check hit us after finishing
 993          * device recognition but before the register work could be
 994          * queued.
 995          */
 996         if (!device_is_registered(&sch->dev))
 997                 goto out_err;
 998         css_update_ssd_info(sch);
 999         /*
1000          * io_subchannel_register() will also be called after device
1001          * recognition has been done for a boxed device (which will already
1002          * be registered). We need to reprobe since we may now have sense id
1003          * information.
1004          */
1005         if (device_is_registered(&cdev->dev)) {
1006                 if (!cdev->drv) {
1007                         ret = device_reprobe(&cdev->dev);
1008                         if (ret)
1009                                 /* We can't do much here. */
1010                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
1011                                               " %d for 0.%x.%04x\n", ret,
1012                                               cdev->private->dev_id.ssid,
1013                                               cdev->private->dev_id.devno);
1014                 }
1015                 goto out;
1016         }
1017         /*
1018          * Now we know this subchannel will stay, we can throw
1019          * our delayed uevent.
1020          */
1021         dev_set_uevent_suppress(&sch->dev, 0);
1022         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1023         /* make it known to the system */
1024         ret = ccw_device_register(cdev);
1025         if (ret) {
1026                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
1027                               cdev->private->dev_id.ssid,
1028                               cdev->private->dev_id.devno, ret);
1029                 spin_lock_irqsave(sch->lock, flags);
1030                 sch_set_cdev(sch, NULL);
1031                 spin_unlock_irqrestore(sch->lock, flags);
1032                 /* Release initial device reference. */
1033                 put_device(&cdev->dev);
1034                 goto out_err;
1035         }
1036 out:
1037         cdev->private->flags.recog_done = 1;
1038         wake_up(&cdev->private->wait_q);
1039 out_err:
1040         /* Release reference for workqueue processing. */
1041         put_device(&cdev->dev);
1042         if (atomic_dec_and_test(&ccw_device_init_count))
1043                 wake_up(&ccw_device_init_wq);
1044 }
1045
1046 static void ccw_device_call_sch_unregister(struct work_struct *work)
1047 {
1048         struct ccw_device_private *priv;
1049         struct ccw_device *cdev;
1050         struct subchannel *sch;
1051
1052         priv = container_of(work, struct ccw_device_private, kick_work);
1053         cdev = priv->cdev;
1054         /* Get subchannel reference for local processing. */
1055         if (!get_device(cdev->dev.parent))
1056                 return;
1057         sch = to_subchannel(cdev->dev.parent);
1058         css_sch_device_unregister(sch);
1059         /* Release cdev reference for workqueue processing.*/
1060         put_device(&cdev->dev);
1061         /* Release subchannel reference for local processing. */
1062         put_device(&sch->dev);
1063 }
1064
1065 void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
1066 {
1067         /* Get cdev reference for workqueue processing. */
1068         if (!get_device(&cdev->dev))
1069                 return;
1070         PREPARE_WORK(&cdev->private->kick_work,
1071                      ccw_device_call_sch_unregister);
1072         queue_work(slow_path_wq, &cdev->private->kick_work);
1073 }
1074
1075 /*
1076  * subchannel recognition done. Called from the state machine.
1077  */
1078 void
1079 io_subchannel_recog_done(struct ccw_device *cdev)
1080 {
1081         if (css_init_done == 0) {
1082                 cdev->private->flags.recog_done = 1;
1083                 return;
1084         }
1085         switch (cdev->private->state) {
1086         case DEV_STATE_BOXED:
1087                 /* Device did not respond in time. */
1088         case DEV_STATE_NOT_OPER:
1089                 cdev->private->flags.recog_done = 1;
1090                 ccw_device_schedule_sch_unregister(cdev);
1091                 if (atomic_dec_and_test(&ccw_device_init_count))
1092                         wake_up(&ccw_device_init_wq);
1093                 break;
1094         case DEV_STATE_OFFLINE:
1095                 /*
1096                  * We can't register the device in interrupt context so
1097                  * we schedule a work item.
1098                  */
1099                 if (!get_device(&cdev->dev))
1100                         break;
1101                 PREPARE_WORK(&cdev->private->kick_work,
1102                              io_subchannel_register);
1103                 queue_work(slow_path_wq, &cdev->private->kick_work);
1104                 break;
1105         }
1106 }
1107
1108 static int
1109 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1110 {
1111         int rc;
1112         struct ccw_device_private *priv;
1113
1114         sch_set_cdev(sch, cdev);
1115         cdev->ccwlock = sch->lock;
1116
1117         /* Init private data. */
1118         priv = cdev->private;
1119         priv->dev_id.devno = sch->schib.pmcw.dev;
1120         priv->dev_id.ssid = sch->schid.ssid;
1121         priv->schid = sch->schid;
1122         priv->state = DEV_STATE_NOT_OPER;
1123         INIT_LIST_HEAD(&priv->cmb_list);
1124         init_waitqueue_head(&priv->wait_q);
1125         init_timer(&priv->timer);
1126
1127         /* Set an initial name for the device. */
1128         if (cio_is_console(sch->schid))
1129                 cdev->dev.init_name = cio_get_console_cdev_name(sch);
1130         else
1131                 dev_set_name(&cdev->dev, "0.%x.%04x",
1132                              sch->schid.ssid, sch->schib.pmcw.dev);
1133
1134         /* Increase counter of devices currently in recognition. */
1135         atomic_inc(&ccw_device_init_count);
1136
1137         /* Start async. device sensing. */
1138         spin_lock_irq(sch->lock);
1139         rc = ccw_device_recognition(cdev);
1140         spin_unlock_irq(sch->lock);
1141         if (rc) {
1142                 if (atomic_dec_and_test(&ccw_device_init_count))
1143                         wake_up(&ccw_device_init_wq);
1144         }
1145         return rc;
1146 }
1147
1148 static void ccw_device_move_to_sch(struct work_struct *work)
1149 {
1150         struct ccw_device_private *priv;
1151         int rc;
1152         struct subchannel *sch;
1153         struct ccw_device *cdev;
1154         struct subchannel *former_parent;
1155
1156         priv = container_of(work, struct ccw_device_private, kick_work);
1157         sch = priv->sch;
1158         cdev = priv->cdev;
1159         former_parent = to_subchannel(cdev->dev.parent);
1160         /* Get reference for new parent. */
1161         if (!get_device(&sch->dev))
1162                 return;
1163         mutex_lock(&sch->reg_mutex);
1164         /*
1165          * Try to move the ccw device to its new subchannel.
1166          * Note: device_move() changes cdev->dev.parent
1167          */
1168         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
1169         mutex_unlock(&sch->reg_mutex);
1170         if (rc) {
1171                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1172                               "0.%x.%04x failed (ret=%d)!\n",
1173                               cdev->private->dev_id.ssid,
1174                               cdev->private->dev_id.devno, sch->schid.ssid,
1175                               sch->schid.sch_no, rc);
1176                 css_sch_device_unregister(sch);
1177                 /* Put reference for new parent again. */
1178                 put_device(&sch->dev);
1179                 goto out;
1180         }
1181         if (!sch_is_pseudo_sch(former_parent)) {
1182                 spin_lock_irq(former_parent->lock);
1183                 sch_set_cdev(former_parent, NULL);
1184                 spin_unlock_irq(former_parent->lock);
1185                 css_sch_device_unregister(former_parent);
1186                 /* Reset intparm to zeroes. */
1187                 former_parent->config.intparm = 0;
1188                 cio_commit_config(former_parent);
1189         }
1190         sch_attach_device(sch, cdev);
1191 out:
1192         /* Put reference for old parent. */
1193         put_device(&former_parent->dev);
1194         put_device(&cdev->dev);
1195 }
1196
1197 static void io_subchannel_irq(struct subchannel *sch)
1198 {
1199         struct ccw_device *cdev;
1200
1201         cdev = sch_get_cdev(sch);
1202
1203         CIO_TRACE_EVENT(6, "IRQ");
1204         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1205         if (cdev)
1206                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1207 }
1208
1209 void io_subchannel_init_config(struct subchannel *sch)
1210 {
1211         memset(&sch->config, 0, sizeof(sch->config));
1212         sch->config.csense = 1;
1213         /* Use subchannel mp mode when there is more than 1 installed CHPID. */
1214         if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
1215                 sch->config.mp = 1;
1216 }
1217
1218 static void io_subchannel_init_fields(struct subchannel *sch)
1219 {
1220         if (cio_is_console(sch->schid))
1221                 sch->opm = 0xff;
1222         else
1223                 sch->opm = chp_get_sch_opm(sch);
1224         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1225         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1226
1227         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1228                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1229                       sch->schib.pmcw.dev, sch->schid.ssid,
1230                       sch->schid.sch_no, sch->schib.pmcw.pim,
1231                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1232
1233         io_subchannel_init_config(sch);
1234 }
1235
1236 static void io_subchannel_do_unreg(struct work_struct *work)
1237 {
1238         struct subchannel *sch;
1239
1240         sch = container_of(work, struct subchannel, work);
1241         css_sch_device_unregister(sch);
1242         put_device(&sch->dev);
1243 }
1244
1245 /* Schedule unregister if we have no cdev. */
1246 static void io_subchannel_schedule_removal(struct subchannel *sch)
1247 {
1248         get_device(&sch->dev);
1249         INIT_WORK(&sch->work, io_subchannel_do_unreg);
1250         queue_work(slow_path_wq, &sch->work);
1251 }
1252
1253 /*
1254  * Note: We always return 0 so that we bind to the device even on error.
1255  * This is needed so that our remove function is called on unregister.
1256  */
1257 static int io_subchannel_probe(struct subchannel *sch)
1258 {
1259         struct ccw_device *cdev;
1260         int rc;
1261         unsigned long flags;
1262         struct ccw_dev_id dev_id;
1263
1264         cdev = sch_get_cdev(sch);
1265         if (cdev) {
1266                 rc = sysfs_create_group(&sch->dev.kobj,
1267                                         &io_subchannel_attr_group);
1268                 if (rc)
1269                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1270                                       "attributes for subchannel "
1271                                       "0.%x.%04x (rc=%d)\n",
1272                                       sch->schid.ssid, sch->schid.sch_no, rc);
1273                 /*
1274                  * This subchannel already has an associated ccw_device.
1275                  * Throw the delayed uevent for the subchannel, register
1276                  * the ccw_device and exit. This happens for all early
1277                  * devices, e.g. the console.
1278                  */
1279                 dev_set_uevent_suppress(&sch->dev, 0);
1280                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1281                 cdev->dev.groups = ccwdev_attr_groups;
1282                 device_initialize(&cdev->dev);
1283                 ccw_device_register(cdev);
1284                 /*
1285                  * Check if the device is already online. If it is
1286                  * the reference count needs to be corrected since we
1287                  * didn't obtain a reference in ccw_device_set_online.
1288                  */
1289                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1290                     cdev->private->state != DEV_STATE_OFFLINE &&
1291                     cdev->private->state != DEV_STATE_BOXED)
1292                         get_device(&cdev->dev);
1293                 return 0;
1294         }
1295         io_subchannel_init_fields(sch);
1296         rc = cio_commit_config(sch);
1297         if (rc)
1298                 goto out_schedule;
1299         rc = sysfs_create_group(&sch->dev.kobj,
1300                                 &io_subchannel_attr_group);
1301         if (rc)
1302                 goto out_schedule;
1303         /* Allocate I/O subchannel private data. */
1304         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1305                                GFP_KERNEL | GFP_DMA);
1306         if (!sch->private)
1307                 goto out_err;
1308         /*
1309          * First check if a fitting device may be found amongst the
1310          * disconnected devices or in the orphanage.
1311          */
1312         dev_id.devno = sch->schib.pmcw.dev;
1313         dev_id.ssid = sch->schid.ssid;
1314         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1315         if (!cdev)
1316                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1317                                                      &dev_id);
1318         if (cdev) {
1319                 /*
1320                  * Schedule moving the device until when we have a registered
1321                  * subchannel to move to and succeed the probe. We can
1322                  * unregister later again, when the probe is through.
1323                  */
1324                 cdev->private->sch = sch;
1325                 PREPARE_WORK(&cdev->private->kick_work,
1326                              ccw_device_move_to_sch);
1327                 queue_work(slow_path_wq, &cdev->private->kick_work);
1328                 return 0;
1329         }
1330         cdev = io_subchannel_create_ccwdev(sch);
1331         if (IS_ERR(cdev))
1332                 goto out_err;
1333         rc = io_subchannel_recog(cdev, sch);
1334         if (rc) {
1335                 spin_lock_irqsave(sch->lock, flags);
1336                 io_subchannel_recog_done(cdev);
1337                 spin_unlock_irqrestore(sch->lock, flags);
1338         }
1339         return 0;
1340 out_err:
1341         kfree(sch->private);
1342         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1343 out_schedule:
1344         io_subchannel_schedule_removal(sch);
1345         return 0;
1346 }
1347
1348 static int
1349 io_subchannel_remove (struct subchannel *sch)
1350 {
1351         struct ccw_device *cdev;
1352         unsigned long flags;
1353
1354         cdev = sch_get_cdev(sch);
1355         if (!cdev)
1356                 return 0;
1357         /* Set ccw device to not operational and drop reference. */
1358         spin_lock_irqsave(cdev->ccwlock, flags);
1359         sch_set_cdev(sch, NULL);
1360         cdev->private->state = DEV_STATE_NOT_OPER;
1361         spin_unlock_irqrestore(cdev->ccwlock, flags);
1362         ccw_device_unregister(cdev);
1363         kfree(sch->private);
1364         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1365         return 0;
1366 }
1367
1368 static int io_subchannel_notify(struct subchannel *sch, int event)
1369 {
1370         struct ccw_device *cdev;
1371
1372         cdev = sch_get_cdev(sch);
1373         if (!cdev)
1374                 return 0;
1375         return ccw_device_notify(cdev, event);
1376 }
1377
1378 static void io_subchannel_verify(struct subchannel *sch)
1379 {
1380         struct ccw_device *cdev;
1381
1382         cdev = sch_get_cdev(sch);
1383         if (cdev)
1384                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1385 }
1386
1387 static int check_for_io_on_path(struct subchannel *sch, int mask)
1388 {
1389         if (cio_update_schib(sch))
1390                 return 0;
1391         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1392                 return 1;
1393         return 0;
1394 }
1395
1396 static void terminate_internal_io(struct subchannel *sch,
1397                                   struct ccw_device *cdev)
1398 {
1399         if (cio_clear(sch)) {
1400                 /* Recheck device in case clear failed. */
1401                 sch->lpm = 0;
1402                 if (cdev->online)
1403                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1404                 else
1405                         css_schedule_eval(sch->schid);
1406                 return;
1407         }
1408         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1409         /* Request retry of internal operation. */
1410         cdev->private->flags.intretry = 1;
1411         /* Call handler. */
1412         if (cdev->handler)
1413                 cdev->handler(cdev, cdev->private->intparm,
1414                               ERR_PTR(-EIO));
1415 }
1416
1417 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1418 {
1419         struct ccw_device *cdev;
1420
1421         cdev = sch_get_cdev(sch);
1422         if (!cdev)
1423                 return;
1424         if (check_for_io_on_path(sch, mask)) {
1425                 if (cdev->private->state == DEV_STATE_ONLINE)
1426                         ccw_device_kill_io(cdev);
1427                 else {
1428                         terminate_internal_io(sch, cdev);
1429                         /* Re-start path verification. */
1430                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1431                 }
1432         } else
1433                 /* trigger path verification. */
1434                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1435
1436 }
1437
1438 static int io_subchannel_chp_event(struct subchannel *sch,
1439                                    struct chp_link *link, int event)
1440 {
1441         int mask;
1442
1443         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1444         if (!mask)
1445                 return 0;
1446         switch (event) {
1447         case CHP_VARY_OFF:
1448                 sch->opm &= ~mask;
1449                 sch->lpm &= ~mask;
1450                 io_subchannel_terminate_path(sch, mask);
1451                 break;
1452         case CHP_VARY_ON:
1453                 sch->opm |= mask;
1454                 sch->lpm |= mask;
1455                 io_subchannel_verify(sch);
1456                 break;
1457         case CHP_OFFLINE:
1458                 if (cio_update_schib(sch))
1459                         return -ENODEV;
1460                 io_subchannel_terminate_path(sch, mask);
1461                 break;
1462         case CHP_ONLINE:
1463                 if (cio_update_schib(sch))
1464                         return -ENODEV;
1465                 sch->lpm |= mask & sch->opm;
1466                 io_subchannel_verify(sch);
1467                 break;
1468         }
1469         return 0;
1470 }
1471
1472 static void
1473 io_subchannel_shutdown(struct subchannel *sch)
1474 {
1475         struct ccw_device *cdev;
1476         int ret;
1477
1478         cdev = sch_get_cdev(sch);
1479
1480         if (cio_is_console(sch->schid))
1481                 return;
1482         if (!sch->schib.pmcw.ena)
1483                 /* Nothing to do. */
1484                 return;
1485         ret = cio_disable_subchannel(sch);
1486         if (ret != -EBUSY)
1487                 /* Subchannel is disabled, we're done. */
1488                 return;
1489         cdev->private->state = DEV_STATE_QUIESCE;
1490         if (cdev->handler)
1491                 cdev->handler(cdev, cdev->private->intparm,
1492                               ERR_PTR(-EIO));
1493         ret = ccw_device_cancel_halt_clear(cdev);
1494         if (ret == -EBUSY) {
1495                 ccw_device_set_timeout(cdev, HZ/10);
1496                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1497         }
1498         cio_disable_subchannel(sch);
1499 }
1500
1501 static int io_subchannel_get_status(struct subchannel *sch)
1502 {
1503         struct schib schib;
1504
1505         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1506                 return CIO_GONE;
1507         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1508                 return CIO_REVALIDATE;
1509         if (!sch->lpm)
1510                 return CIO_NO_PATH;
1511         return CIO_OPER;
1512 }
1513
1514 static int device_is_disconnected(struct ccw_device *cdev)
1515 {
1516         if (!cdev)
1517                 return 0;
1518         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1519                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1520 }
1521
1522 static int recovery_check(struct device *dev, void *data)
1523 {
1524         struct ccw_device *cdev = to_ccwdev(dev);
1525         int *redo = data;
1526
1527         spin_lock_irq(cdev->ccwlock);
1528         switch (cdev->private->state) {
1529         case DEV_STATE_DISCONNECTED:
1530                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1531                               cdev->private->dev_id.ssid,
1532                               cdev->private->dev_id.devno);
1533                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1534                 *redo = 1;
1535                 break;
1536         case DEV_STATE_DISCONNECTED_SENSE_ID:
1537                 *redo = 1;
1538                 break;
1539         }
1540         spin_unlock_irq(cdev->ccwlock);
1541
1542         return 0;
1543 }
1544
1545 static void recovery_work_func(struct work_struct *unused)
1546 {
1547         int redo = 0;
1548
1549         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1550         if (redo) {
1551                 spin_lock_irq(&recovery_lock);
1552                 if (!timer_pending(&recovery_timer)) {
1553                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1554                                 recovery_phase++;
1555                         mod_timer(&recovery_timer, jiffies +
1556                                   recovery_delay[recovery_phase] * HZ);
1557                 }
1558                 spin_unlock_irq(&recovery_lock);
1559         } else
1560                 CIO_MSG_EVENT(4, "recovery: end\n");
1561 }
1562
1563 static DECLARE_WORK(recovery_work, recovery_work_func);
1564
1565 static void recovery_func(unsigned long data)
1566 {
1567         /*
1568          * We can't do our recovery in softirq context and it's not
1569          * performance critical, so we schedule it.
1570          */
1571         schedule_work(&recovery_work);
1572 }
1573
1574 static void ccw_device_schedule_recovery(void)
1575 {
1576         unsigned long flags;
1577
1578         CIO_MSG_EVENT(4, "recovery: schedule\n");
1579         spin_lock_irqsave(&recovery_lock, flags);
1580         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1581                 recovery_phase = 0;
1582                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1583         }
1584         spin_unlock_irqrestore(&recovery_lock, flags);
1585 }
1586
1587 static int purge_fn(struct device *dev, void *data)
1588 {
1589         struct ccw_device *cdev = to_ccwdev(dev);
1590         struct ccw_device_private *priv = cdev->private;
1591         int unreg;
1592
1593         spin_lock_irq(cdev->ccwlock);
1594         unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1595                 (priv->state == DEV_STATE_OFFLINE);
1596         spin_unlock_irq(cdev->ccwlock);
1597         if (!unreg)
1598                 goto out;
1599         CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1600                       priv->dev_id.devno);
1601         ccw_device_schedule_sch_unregister(cdev);
1602
1603 out:
1604         /* Abort loop in case of pending signal. */
1605         if (signal_pending(current))
1606                 return -EINTR;
1607
1608         return 0;
1609 }
1610
1611 /**
1612  * ccw_purge_blacklisted - purge unused, blacklisted devices
1613  *
1614  * Unregister all ccw devices that are offline and on the blacklist.
1615  */
1616 int ccw_purge_blacklisted(void)
1617 {
1618         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1619         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1620         return 0;
1621 }
1622
1623 static void device_set_disconnected(struct ccw_device *cdev)
1624 {
1625         if (!cdev)
1626                 return;
1627         ccw_device_set_timeout(cdev, 0);
1628         cdev->private->flags.fake_irb = 0;
1629         cdev->private->state = DEV_STATE_DISCONNECTED;
1630         if (cdev->online)
1631                 ccw_device_schedule_recovery();
1632 }
1633
1634 void ccw_device_set_notoper(struct ccw_device *cdev)
1635 {
1636         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1637
1638         CIO_TRACE_EVENT(2, "notoper");
1639         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1640         ccw_device_set_timeout(cdev, 0);
1641         cio_disable_subchannel(sch);
1642         cdev->private->state = DEV_STATE_NOT_OPER;
1643 }
1644
1645 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1646 {
1647         int event, ret, disc;
1648         unsigned long flags;
1649         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1650         struct ccw_device *cdev;
1651
1652         spin_lock_irqsave(sch->lock, flags);
1653         cdev = sch_get_cdev(sch);
1654         disc = device_is_disconnected(cdev);
1655         if (disc && slow) {
1656                 /* Disconnected devices are evaluated directly only.*/
1657                 spin_unlock_irqrestore(sch->lock, flags);
1658                 return 0;
1659         }
1660         /* No interrupt after machine check - kill pending timers. */
1661         if (cdev)
1662                 ccw_device_set_timeout(cdev, 0);
1663         if (!disc && !slow) {
1664                 /* Non-disconnected devices are evaluated on the slow path. */
1665                 spin_unlock_irqrestore(sch->lock, flags);
1666                 return -EAGAIN;
1667         }
1668         event = io_subchannel_get_status(sch);
1669         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1670                       sch->schid.ssid, sch->schid.sch_no, event,
1671                       disc ? "disconnected" : "normal",
1672                       slow ? "slow" : "fast");
1673         /* Analyze subchannel status. */
1674         action = NONE;
1675         switch (event) {
1676         case CIO_NO_PATH:
1677                 if (disc) {
1678                         /* Check if paths have become available. */
1679                         action = REPROBE;
1680                         break;
1681                 }
1682                 /* fall through */
1683         case CIO_GONE:
1684                 /* Ask driver what to do with device. */
1685                 if (io_subchannel_notify(sch, event))
1686                         action = DISC;
1687                 else
1688                         action = UNREGISTER;
1689                 break;
1690         case CIO_REVALIDATE:
1691                 /* Device will be removed, so no notify necessary. */
1692                 if (disc)
1693                         /* Reprobe because immediate unregister might block. */
1694                         action = REPROBE;
1695                 else
1696                         action = UNREGISTER_PROBE;
1697                 break;
1698         case CIO_OPER:
1699                 if (disc)
1700                         /* Get device operational again. */
1701                         action = REPROBE;
1702                 break;
1703         }
1704         /* Perform action. */
1705         ret = 0;
1706         switch (action) {
1707         case UNREGISTER:
1708         case UNREGISTER_PROBE:
1709                 ccw_device_set_notoper(cdev);
1710                 /* Unregister device (will use subchannel lock). */
1711                 spin_unlock_irqrestore(sch->lock, flags);
1712                 css_sch_device_unregister(sch);
1713                 spin_lock_irqsave(sch->lock, flags);
1714                 break;
1715         case REPROBE:
1716                 ccw_device_trigger_reprobe(cdev);
1717                 break;
1718         case DISC:
1719                 device_set_disconnected(cdev);
1720                 break;
1721         default:
1722                 break;
1723         }
1724         spin_unlock_irqrestore(sch->lock, flags);
1725         /* Probe if necessary. */
1726         if (action == UNREGISTER_PROBE)
1727                 ret = css_probe_device(sch->schid);
1728
1729         return ret;
1730 }
1731
1732 #ifdef CONFIG_CCW_CONSOLE
1733 static struct ccw_device console_cdev;
1734 static char console_cdev_name[10] = "0.x.xxxx";
1735 static struct ccw_device_private console_private;
1736 static int console_cdev_in_use;
1737
1738 static DEFINE_SPINLOCK(ccw_console_lock);
1739
1740 spinlock_t * cio_get_console_lock(void)
1741 {
1742         return &ccw_console_lock;
1743 }
1744
1745 static int ccw_device_console_enable(struct ccw_device *cdev,
1746                                      struct subchannel *sch)
1747 {
1748         int rc;
1749
1750         /* Attach subchannel private data. */
1751         sch->private = cio_get_console_priv();
1752         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1753         io_subchannel_init_fields(sch);
1754         rc = cio_commit_config(sch);
1755         if (rc)
1756                 return rc;
1757         sch->driver = &io_subchannel_driver;
1758         /* Initialize the ccw_device structure. */
1759         cdev->dev.parent= &sch->dev;
1760         rc = io_subchannel_recog(cdev, sch);
1761         if (rc)
1762                 return rc;
1763
1764         /* Now wait for the async. recognition to come to an end. */
1765         spin_lock_irq(cdev->ccwlock);
1766         while (!dev_fsm_final_state(cdev))
1767                 wait_cons_dev();
1768         rc = -EIO;
1769         if (cdev->private->state != DEV_STATE_OFFLINE)
1770                 goto out_unlock;
1771         ccw_device_online(cdev);
1772         while (!dev_fsm_final_state(cdev))
1773                 wait_cons_dev();
1774         if (cdev->private->state != DEV_STATE_ONLINE)
1775                 goto out_unlock;
1776         rc = 0;
1777 out_unlock:
1778         spin_unlock_irq(cdev->ccwlock);
1779         return 0;
1780 }
1781
1782 struct ccw_device *
1783 ccw_device_probe_console(void)
1784 {
1785         struct subchannel *sch;
1786         int ret;
1787
1788         if (xchg(&console_cdev_in_use, 1) != 0)
1789                 return ERR_PTR(-EBUSY);
1790         sch = cio_probe_console();
1791         if (IS_ERR(sch)) {
1792                 console_cdev_in_use = 0;
1793                 return (void *) sch;
1794         }
1795         memset(&console_cdev, 0, sizeof(struct ccw_device));
1796         memset(&console_private, 0, sizeof(struct ccw_device_private));
1797         console_cdev.private = &console_private;
1798         console_private.cdev = &console_cdev;
1799         ret = ccw_device_console_enable(&console_cdev, sch);
1800         if (ret) {
1801                 cio_release_console();
1802                 console_cdev_in_use = 0;
1803                 return ERR_PTR(ret);
1804         }
1805         console_cdev.online = 1;
1806         return &console_cdev;
1807 }
1808
1809 static int ccw_device_pm_restore(struct device *dev);
1810
1811 int ccw_device_force_console(void)
1812 {
1813         if (!console_cdev_in_use)
1814                 return -ENODEV;
1815         return ccw_device_pm_restore(&console_cdev.dev);
1816 }
1817 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1818
1819 const char *cio_get_console_cdev_name(struct subchannel *sch)
1820 {
1821         snprintf(console_cdev_name, 10, "0.%x.%04x",
1822                  sch->schid.ssid, sch->schib.pmcw.dev);
1823         return (const char *)console_cdev_name;
1824 }
1825 #endif
1826
1827 /*
1828  * get ccw_device matching the busid, but only if owned by cdrv
1829  */
1830 static int
1831 __ccwdev_check_busid(struct device *dev, void *id)
1832 {
1833         char *bus_id;
1834
1835         bus_id = id;
1836
1837         return (strcmp(bus_id, dev_name(dev)) == 0);
1838 }
1839
1840
1841 /**
1842  * get_ccwdev_by_busid() - obtain device from a bus id
1843  * @cdrv: driver the device is owned by
1844  * @bus_id: bus id of the device to be searched
1845  *
1846  * This function searches all devices owned by @cdrv for a device with a bus
1847  * id matching @bus_id.
1848  * Returns:
1849  *  If a match is found, its reference count of the found device is increased
1850  *  and it is returned; else %NULL is returned.
1851  */
1852 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1853                                        const char *bus_id)
1854 {
1855         struct device *dev;
1856         struct device_driver *drv;
1857
1858         drv = get_driver(&cdrv->driver);
1859         if (!drv)
1860                 return NULL;
1861
1862         dev = driver_find_device(drv, NULL, (void *)bus_id,
1863                                  __ccwdev_check_busid);
1864         put_driver(drv);
1865
1866         return dev ? to_ccwdev(dev) : NULL;
1867 }
1868
1869 /************************** device driver handling ************************/
1870
1871 /* This is the implementation of the ccw_driver class. The probe, remove
1872  * and release methods are initially very similar to the device_driver
1873  * implementations, with the difference that they have ccw_device
1874  * arguments.
1875  *
1876  * A ccw driver also contains the information that is needed for
1877  * device matching.
1878  */
1879 static int
1880 ccw_device_probe (struct device *dev)
1881 {
1882         struct ccw_device *cdev = to_ccwdev(dev);
1883         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1884         int ret;
1885
1886         cdev->drv = cdrv; /* to let the driver call _set_online */
1887
1888         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1889
1890         if (ret) {
1891                 cdev->drv = NULL;
1892                 return ret;
1893         }
1894
1895         return 0;
1896 }
1897
1898 static int
1899 ccw_device_remove (struct device *dev)
1900 {
1901         struct ccw_device *cdev = to_ccwdev(dev);
1902         struct ccw_driver *cdrv = cdev->drv;
1903         int ret;
1904
1905         if (cdrv->remove)
1906                 cdrv->remove(cdev);
1907         if (cdev->online) {
1908                 cdev->online = 0;
1909                 spin_lock_irq(cdev->ccwlock);
1910                 ret = ccw_device_offline(cdev);
1911                 spin_unlock_irq(cdev->ccwlock);
1912                 if (ret == 0)
1913                         wait_event(cdev->private->wait_q,
1914                                    dev_fsm_final_state(cdev));
1915                 else
1916                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1917                                       "device 0.%x.%04x\n",
1918                                       ret, cdev->private->dev_id.ssid,
1919                                       cdev->private->dev_id.devno);
1920                 /* Give up reference obtained in ccw_device_set_online(). */
1921                 put_device(&cdev->dev);
1922         }
1923         ccw_device_set_timeout(cdev, 0);
1924         cdev->drv = NULL;
1925         return 0;
1926 }
1927
1928 static void ccw_device_shutdown(struct device *dev)
1929 {
1930         struct ccw_device *cdev;
1931
1932         cdev = to_ccwdev(dev);
1933         if (cdev->drv && cdev->drv->shutdown)
1934                 cdev->drv->shutdown(cdev);
1935         disable_cmf(cdev);
1936 }
1937
1938 static int ccw_device_pm_prepare(struct device *dev)
1939 {
1940         struct ccw_device *cdev = to_ccwdev(dev);
1941
1942         if (work_pending(&cdev->private->kick_work))
1943                 return -EAGAIN;
1944         /* Fail while device is being set online/offline. */
1945         if (atomic_read(&cdev->private->onoff))
1946                 return -EAGAIN;
1947
1948         if (cdev->online && cdev->drv && cdev->drv->prepare)
1949                 return cdev->drv->prepare(cdev);
1950
1951         return 0;
1952 }
1953
1954 static void ccw_device_pm_complete(struct device *dev)
1955 {
1956         struct ccw_device *cdev = to_ccwdev(dev);
1957
1958         if (cdev->online && cdev->drv && cdev->drv->complete)
1959                 cdev->drv->complete(cdev);
1960 }
1961
1962 static int ccw_device_pm_freeze(struct device *dev)
1963 {
1964         struct ccw_device *cdev = to_ccwdev(dev);
1965         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1966         int ret, cm_enabled;
1967
1968         /* Fail suspend while device is in transistional state. */
1969         if (!dev_fsm_final_state(cdev))
1970                 return -EAGAIN;
1971         if (!cdev->online)
1972                 return 0;
1973         if (cdev->drv && cdev->drv->freeze) {
1974                 ret = cdev->drv->freeze(cdev);
1975                 if (ret)
1976                         return ret;
1977         }
1978
1979         spin_lock_irq(sch->lock);
1980         cm_enabled = cdev->private->cmb != NULL;
1981         spin_unlock_irq(sch->lock);
1982         if (cm_enabled) {
1983                 /* Don't have the css write on memory. */
1984                 ret = ccw_set_cmf(cdev, 0);
1985                 if (ret)
1986                         return ret;
1987         }
1988         /* From here on, disallow device driver I/O. */
1989         spin_lock_irq(sch->lock);
1990         ret = cio_disable_subchannel(sch);
1991         spin_unlock_irq(sch->lock);
1992
1993         return ret;
1994 }
1995
1996 static int ccw_device_pm_thaw(struct device *dev)
1997 {
1998         struct ccw_device *cdev = to_ccwdev(dev);
1999         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2000         int ret, cm_enabled;
2001
2002         if (!cdev->online)
2003                 return 0;
2004
2005         spin_lock_irq(sch->lock);
2006         /* Allow device driver I/O again. */
2007         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
2008         cm_enabled = cdev->private->cmb != NULL;
2009         spin_unlock_irq(sch->lock);
2010         if (ret)
2011                 return ret;
2012
2013         if (cm_enabled) {
2014                 ret = ccw_set_cmf(cdev, 1);
2015                 if (ret)
2016                         return ret;
2017         }
2018
2019         if (cdev->drv && cdev->drv->thaw)
2020                 ret = cdev->drv->thaw(cdev);
2021
2022         return ret;
2023 }
2024
2025 static void __ccw_device_pm_restore(struct ccw_device *cdev)
2026 {
2027         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2028         int ret;
2029
2030         if (cio_is_console(sch->schid))
2031                 goto out;
2032         /*
2033          * While we were sleeping, devices may have gone or become
2034          * available again. Kick re-detection.
2035          */
2036         spin_lock_irq(sch->lock);
2037         cdev->private->flags.resuming = 1;
2038         ret = ccw_device_recognition(cdev);
2039         spin_unlock_irq(sch->lock);
2040         if (ret) {
2041                 CIO_MSG_EVENT(0, "Couldn't start recognition for device "
2042                               "0.%x.%04x (ret=%d)\n",
2043                               cdev->private->dev_id.ssid,
2044                               cdev->private->dev_id.devno, ret);
2045                 spin_lock_irq(sch->lock);
2046                 cdev->private->state = DEV_STATE_DISCONNECTED;
2047                 spin_unlock_irq(sch->lock);
2048                 /* notify driver after the resume cb */
2049                 goto out;
2050         }
2051         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
2052                    cdev->private->state == DEV_STATE_DISCONNECTED);
2053
2054 out:
2055         cdev->private->flags.resuming = 0;
2056 }
2057
2058 static int resume_handle_boxed(struct ccw_device *cdev)
2059 {
2060         cdev->private->state = DEV_STATE_BOXED;
2061         if (ccw_device_notify(cdev, CIO_BOXED))
2062                 return 0;
2063         ccw_device_schedule_sch_unregister(cdev);
2064         return -ENODEV;
2065 }
2066
2067 static int resume_handle_disc(struct ccw_device *cdev)
2068 {
2069         cdev->private->state = DEV_STATE_DISCONNECTED;
2070         if (ccw_device_notify(cdev, CIO_GONE))
2071                 return 0;
2072         ccw_device_schedule_sch_unregister(cdev);
2073         return -ENODEV;
2074 }
2075
2076 static int ccw_device_pm_restore(struct device *dev)
2077 {
2078         struct ccw_device *cdev = to_ccwdev(dev);
2079         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2080         int ret = 0, cm_enabled;
2081
2082         __ccw_device_pm_restore(cdev);
2083         spin_lock_irq(sch->lock);
2084         if (cio_is_console(sch->schid)) {
2085                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
2086                 spin_unlock_irq(sch->lock);
2087                 goto out_restore;
2088         }
2089         cdev->private->flags.donotify = 0;
2090         /* check recognition results */
2091         switch (cdev->private->state) {
2092         case DEV_STATE_OFFLINE:
2093                 break;
2094         case DEV_STATE_BOXED:
2095                 ret = resume_handle_boxed(cdev);
2096                 spin_unlock_irq(sch->lock);
2097                 if (ret)
2098                         goto out;
2099                 goto out_restore;
2100         case DEV_STATE_DISCONNECTED:
2101                 goto out_disc_unlock;
2102         default:
2103                 goto out_unreg_unlock;
2104         }
2105         /* check if the device id has changed */
2106         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
2107                 CIO_MSG_EVENT(0, "resume: sch 0.%x.%04x: failed (devno "
2108                               "changed from %04x to %04x)\n",
2109                               sch->schid.ssid, sch->schid.sch_no,
2110                               cdev->private->dev_id.devno,
2111                               sch->schib.pmcw.dev);
2112                 goto out_unreg_unlock;
2113         }
2114         /* check if the device type has changed */
2115         if (!ccw_device_test_sense_data(cdev)) {
2116                 ccw_device_update_sense_data(cdev);
2117                 PREPARE_WORK(&cdev->private->kick_work,
2118                              ccw_device_do_unbind_bind);
2119                 queue_work(ccw_device_work, &cdev->private->kick_work);
2120                 ret = -ENODEV;
2121                 goto out_unlock;
2122         }
2123         if (!cdev->online) {
2124                 ret = 0;
2125                 goto out_unlock;
2126         }
2127         ret = ccw_device_online(cdev);
2128         if (ret)
2129                 goto out_disc_unlock;
2130
2131         cm_enabled = cdev->private->cmb != NULL;
2132         spin_unlock_irq(sch->lock);
2133
2134         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
2135         if (cdev->private->state != DEV_STATE_ONLINE) {
2136                 spin_lock_irq(sch->lock);
2137                 goto out_disc_unlock;
2138         }
2139         if (cm_enabled) {
2140                 ret = ccw_set_cmf(cdev, 1);
2141                 if (ret) {
2142                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
2143                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
2144                                       cdev->private->dev_id.devno, ret);
2145                         ret = 0;
2146                 }
2147         }
2148
2149 out_restore:
2150         if (cdev->online && cdev->drv && cdev->drv->restore)
2151                 ret = cdev->drv->restore(cdev);
2152 out:
2153         return ret;
2154
2155 out_disc_unlock:
2156         ret = resume_handle_disc(cdev);
2157         spin_unlock_irq(sch->lock);
2158         if (ret)
2159                 return ret;
2160         goto out_restore;
2161
2162 out_unreg_unlock:
2163         ccw_device_schedule_sch_unregister(cdev);
2164         ret = -ENODEV;
2165 out_unlock:
2166         spin_unlock_irq(sch->lock);
2167         return ret;
2168 }
2169
2170 static struct dev_pm_ops ccw_pm_ops = {
2171         .prepare = ccw_device_pm_prepare,
2172         .complete = ccw_device_pm_complete,
2173         .freeze = ccw_device_pm_freeze,
2174         .thaw = ccw_device_pm_thaw,
2175         .restore = ccw_device_pm_restore,
2176 };
2177
2178 struct bus_type ccw_bus_type = {
2179         .name   = "ccw",
2180         .match  = ccw_bus_match,
2181         .uevent = ccw_uevent,
2182         .probe  = ccw_device_probe,
2183         .remove = ccw_device_remove,
2184         .shutdown = ccw_device_shutdown,
2185         .pm = &ccw_pm_ops,
2186 };
2187
2188 /**
2189  * ccw_driver_register() - register a ccw driver
2190  * @cdriver: driver to be registered
2191  *
2192  * This function is mainly a wrapper around driver_register().
2193  * Returns:
2194  *   %0 on success and a negative error value on failure.
2195  */
2196 int ccw_driver_register(struct ccw_driver *cdriver)
2197 {
2198         struct device_driver *drv = &cdriver->driver;
2199
2200         drv->bus = &ccw_bus_type;
2201         drv->name = cdriver->name;
2202         drv->owner = cdriver->owner;
2203
2204         return driver_register(drv);
2205 }
2206
2207 /**
2208  * ccw_driver_unregister() - deregister a ccw driver
2209  * @cdriver: driver to be deregistered
2210  *
2211  * This function is mainly a wrapper around driver_unregister().
2212  */
2213 void ccw_driver_unregister(struct ccw_driver *cdriver)
2214 {
2215         driver_unregister(&cdriver->driver);
2216 }
2217
2218 /* Helper func for qdio. */
2219 struct subchannel_id
2220 ccw_device_get_subchannel_id(struct ccw_device *cdev)
2221 {
2222         struct subchannel *sch;
2223
2224         sch = to_subchannel(cdev->dev.parent);
2225         return sch->schid;
2226 }
2227
2228 MODULE_LICENSE("GPL");
2229 EXPORT_SYMBOL(ccw_device_set_online);
2230 EXPORT_SYMBOL(ccw_device_set_offline);
2231 EXPORT_SYMBOL(ccw_driver_register);
2232 EXPORT_SYMBOL(ccw_driver_unregister);
2233 EXPORT_SYMBOL(get_ccwdev_by_busid);
2234 EXPORT_SYMBOL(ccw_bus_type);
2235 EXPORT_SYMBOL(ccw_device_work);
2236 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);