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   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 static void recovery_func(unsigned long data);
 135 struct workqueue_struct *ccw_device_work;
 136 wait_queue_head_t ccw_device_init_wq;
 137 atomic_t ccw_device_init_count;
 138
 139 static struct css_device_id io_subchannel_ids[] = {
 140         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 141         { /* end of list */ },
 142 };
 143 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 144
 145 static int io_subchannel_prepare(struct subchannel *sch)
 146 {
 147         struct ccw_device *cdev;
 148         /*
 149          * Don't allow suspend while a ccw device registration
 150          * is still outstanding.
 151          */
 152         cdev = sch_get_cdev(sch);
 153         if (cdev && !device_is_registered(&cdev->dev))
 154                 return -EAGAIN;
 155         return 0;
 156 }
 157
 158 static void io_subchannel_settle(void)
 159 {
 160         wait_event(ccw_device_init_wq,
 161                    atomic_read(&ccw_device_init_count) == 0);
 162         flush_workqueue(ccw_device_work);
 163 }
 164
 165 static struct css_driver io_subchannel_driver = {
 166         .owner = THIS_MODULE,
 167         .subchannel_type = io_subchannel_ids,
 168         .name = "io_subchannel",
 169         .irq = io_subchannel_irq,
 170         .sch_event = io_subchannel_sch_event,
 171         .chp_event = io_subchannel_chp_event,
 172         .probe = io_subchannel_probe,
 173         .remove = io_subchannel_remove,
 174         .shutdown = io_subchannel_shutdown,
 175         .prepare = io_subchannel_prepare,
 176         .settle = io_subchannel_settle,
 177 };
 178
 179 int __init io_subchannel_init(void)
 180 {
 181         int ret;
 182
 183         init_waitqueue_head(&ccw_device_init_wq);
 184         atomic_set(&ccw_device_init_count, 0);
 185         setup_timer(&recovery_timer, recovery_func, 0);
 186
 187         ccw_device_work = create_singlethread_workqueue("cio");
 188         if (!ccw_device_work)
 189                 return -ENOMEM;
 190         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 191         if (!slow_path_wq) {
 192                 ret = -ENOMEM;
 193                 goto out_err;
 194         }
 195         if ((ret = bus_register (&ccw_bus_type)))
 196                 goto out_err;
 197
 198         ret = css_driver_register(&io_subchannel_driver);
 199         if (ret)
 200                 goto out_err;
 201
 202         return 0;
 203 out_err:
 204         if (ccw_device_work)
 205                 destroy_workqueue(ccw_device_work);
 206         if (slow_path_wq)
 207                 destroy_workqueue(slow_path_wq);
 208         return ret;
 209 }
 210
 211
 212 /************************ device handling **************************/
 213
 214 /*
 215  * A ccw_device has some interfaces in sysfs in addition to the
 216  * standard ones.
 217  * The following entries are designed to export the information which
 218  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 219  * are obvious, so they don't have an entry :)
 220  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 221  */
 222 static ssize_t
 223 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 224 {
 225         struct subchannel *sch = to_subchannel(dev);
 226         struct chsc_ssd_info *ssd = &sch->ssd_info;
 227         ssize_t ret = 0;
 228         int chp;
 229         int mask;
 230
 231         for (chp = 0; chp < 8; chp++) {
 232                 mask = 0x80 >> chp;
 233                 if (ssd->path_mask & mask)
 234                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 235                 else
 236                         ret += sprintf(buf + ret, "00 ");
 237         }
 238         ret += sprintf (buf+ret, "\n");
 239         return min((ssize_t)PAGE_SIZE, ret);
 240 }
 241
 242 static ssize_t
 243 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 244 {
 245         struct subchannel *sch = to_subchannel(dev);
 246         struct pmcw *pmcw = &sch->schib.pmcw;
 247
 248         return sprintf (buf, "%02x %02x %02x\n",
 249                         pmcw->pim, pmcw->pam, pmcw->pom);
 250 }
 251
 252 static ssize_t
 253 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 254 {
 255         struct ccw_device *cdev = to_ccwdev(dev);
 256         struct ccw_device_id *id = &(cdev->id);
 257
 258         if (id->dev_type != 0)
 259                 return sprintf(buf, "%04x/%02x\n",
 260                                 id->dev_type, id->dev_model);
 261         else
 262                 return sprintf(buf, "n/a\n");
 263 }
 264
 265 static ssize_t
 266 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 267 {
 268         struct ccw_device *cdev = to_ccwdev(dev);
 269         struct ccw_device_id *id = &(cdev->id);
 270
 271         return sprintf(buf, "%04x/%02x\n",
 272                        id->cu_type, id->cu_model);
 273 }
 274
 275 static ssize_t
 276 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 277 {
 278         struct ccw_device *cdev = to_ccwdev(dev);
 279         struct ccw_device_id *id = &(cdev->id);
 280         int len;
 281
 282         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 283
 284         return len > PAGE_SIZE ? PAGE_SIZE : len;
 285 }
 286
 287 static ssize_t
 288 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 289 {
 290         struct ccw_device *cdev = to_ccwdev(dev);
 291
 292         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 293 }
 294
 295 int ccw_device_is_orphan(struct ccw_device *cdev)
 296 {
 297         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 298 }
 299
 300 static void ccw_device_unregister(struct ccw_device *cdev)
 301 {
 302         if (test_and_clear_bit(1, &cdev->private->registered)) {
 303                 device_del(&cdev->dev);
 304                 /* Release reference from device_initialize(). */
 305                 put_device(&cdev->dev);
 306         }
 307 }
 308
 309 static void ccw_device_remove_orphan_cb(struct work_struct *work)
 310 {
 311         struct ccw_device_private *priv;
 312         struct ccw_device *cdev;
 313
 314         priv = container_of(work, struct ccw_device_private, kick_work);
 315         cdev = priv->cdev;
 316         ccw_device_unregister(cdev);
 317         /* Release cdev reference for workqueue processing. */
 318         put_device(&cdev->dev);
 319 }
 320
 321 static void
 322 ccw_device_remove_disconnected(struct ccw_device *cdev)
 323 {
 324         unsigned long flags;
 325
 326         /*
 327          * Forced offline in disconnected state means
 328          * 'throw away device'.
 329          */
 330         if (ccw_device_is_orphan(cdev)) {
 331                 /*
 332                  * Deregister ccw device.
 333                  * Unfortunately, we cannot do this directly from the
 334                  * attribute method.
 335                  */
 336                 /* Get cdev reference for workqueue processing. */
 337                 if (!get_device(&cdev->dev))
 338                         return;
 339                 spin_lock_irqsave(cdev->ccwlock, flags);
 340                 cdev->private->state = DEV_STATE_NOT_OPER;
 341                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 342                 PREPARE_WORK(&cdev->private->kick_work,
 343                                 ccw_device_remove_orphan_cb);
 344                 queue_work(slow_path_wq, &cdev->private->kick_work);
 345         } else
 346                 /* Deregister subchannel, which will kill the ccw device. */
 347                 ccw_device_schedule_sch_unregister(cdev);
 348 }
 349
 350 /**
 351  * ccw_device_set_offline() - disable a ccw device for I/O
 352  * @cdev: target ccw device
 353  *
 354  * This function calls the driver's set_offline() function for @cdev, if
 355  * given, and then disables @cdev.
 356  * Returns:
 357  *   %0 on success and a negative error value on failure.
 358  * Context:
 359  *  enabled, ccw device lock not held
 360  */
 361 int ccw_device_set_offline(struct ccw_device *cdev)
 362 {
 363         int ret;
 364
 365         if (!cdev)
 366                 return -ENODEV;
 367         if (!cdev->online || !cdev->drv)
 368                 return -EINVAL;
 369
 370         if (cdev->drv->set_offline) {
 371                 ret = cdev->drv->set_offline(cdev);
 372                 if (ret != 0)
 373                         return ret;
 374         }
 375         cdev->online = 0;
 376         spin_lock_irq(cdev->ccwlock);
 377         /* Wait until a final state or DISCONNECTED is reached */
 378         while (!dev_fsm_final_state(cdev) &&
 379                cdev->private->state != DEV_STATE_DISCONNECTED) {
 380                 spin_unlock_irq(cdev->ccwlock);
 381                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 382                            cdev->private->state == DEV_STATE_DISCONNECTED));
 383                 spin_lock_irq(cdev->ccwlock);
 384         }
 385         ret = ccw_device_offline(cdev);
 386         if (ret)
 387                 goto error;
 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         /* Give up reference from ccw_device_set_online(). */
 392         put_device(&cdev->dev);
 393         return 0;
 394
 395 error:
 396         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device 0.%x.%04x\n",
 397                       ret, cdev->private->dev_id.ssid,
 398                       cdev->private->dev_id.devno);
 399         cdev->private->state = DEV_STATE_OFFLINE;
 400         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 401         spin_unlock_irq(cdev->ccwlock);
 402         /* Give up reference from ccw_device_set_online(). */
 403         put_device(&cdev->dev);
 404         return -ENODEV;
 405 }
 406
 407 /**
 408  * ccw_device_set_online() - enable a ccw device for I/O
 409  * @cdev: target ccw device
 410  *
 411  * This function first enables @cdev and then calls the driver's set_online()
 412  * function for @cdev, if given. If set_online() returns an error, @cdev is
 413  * disabled again.
 414  * Returns:
 415  *   %0 on success and a negative error value on failure.
 416  * Context:
 417  *  enabled, ccw device lock not held
 418  */
 419 int ccw_device_set_online(struct ccw_device *cdev)
 420 {
 421         int ret;
 422         int ret2;
 423
 424         if (!cdev)
 425                 return -ENODEV;
 426         if (cdev->online || !cdev->drv)
 427                 return -EINVAL;
 428         /* Hold on to an extra reference while device is online. */
 429         if (!get_device(&cdev->dev))
 430                 return -ENODEV;
 431
 432         spin_lock_irq(cdev->ccwlock);
 433         ret = ccw_device_online(cdev);
 434         spin_unlock_irq(cdev->ccwlock);
 435         if (ret == 0)
 436                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 437         else {
 438                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 439                               "device 0.%x.%04x\n",
 440                               ret, cdev->private->dev_id.ssid,
 441                               cdev->private->dev_id.devno);
 442                 /* Give up online reference since onlining failed. */
 443                 put_device(&cdev->dev);
 444                 return ret;
 445         }
 446         spin_lock_irq(cdev->ccwlock);
 447         /* Check if online processing was successful */
 448         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 449             (cdev->private->state != DEV_STATE_W4SENSE)) {
 450                 spin_unlock_irq(cdev->ccwlock);
 451                 /* Give up online reference since onlining failed. */
 452                 put_device(&cdev->dev);
 453                 return -ENODEV;
 454         }
 455         spin_unlock_irq(cdev->ccwlock);
 456         if (cdev->drv->set_online)
 457                 ret = cdev->drv->set_online(cdev);
 458         if (ret)
 459                 goto rollback;
 460         cdev->online = 1;
 461         return 0;
 462
 463 rollback:
 464         spin_lock_irq(cdev->ccwlock);
 465         /* Wait until a final state or DISCONNECTED is reached */
 466         while (!dev_fsm_final_state(cdev) &&
 467                cdev->private->state != DEV_STATE_DISCONNECTED) {
 468                 spin_unlock_irq(cdev->ccwlock);
 469                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 470                            cdev->private->state == DEV_STATE_DISCONNECTED));
 471                 spin_lock_irq(cdev->ccwlock);
 472         }
 473         ret2 = ccw_device_offline(cdev);
 474         if (ret2)
 475                 goto error;
 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         /* Give up online reference since onlining failed. */
 480         put_device(&cdev->dev);
 481         return ret;
 482
 483 error:
 484         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 485                       "device 0.%x.%04x\n",
 486                       ret2, cdev->private->dev_id.ssid,
 487                       cdev->private->dev_id.devno);
 488         cdev->private->state = DEV_STATE_OFFLINE;
 489         spin_unlock_irq(cdev->ccwlock);
 490         /* Give up online reference since onlining failed. */
 491         put_device(&cdev->dev);
 492         return ret;
 493 }
 494
 495 static int online_store_handle_offline(struct ccw_device *cdev)
 496 {
 497         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 498                 ccw_device_remove_disconnected(cdev);
 499         else if (cdev->online && cdev->drv && cdev->drv->set_offline)
 500                 return ccw_device_set_offline(cdev);
 501         return 0;
 502 }
 503
 504 static int online_store_recog_and_online(struct ccw_device *cdev)
 505 {
 506         int ret;
 507
 508         /* Do device recognition, if needed. */
 509         if (cdev->private->state == DEV_STATE_BOXED) {
 510                 ret = ccw_device_recognition(cdev);
 511                 if (ret) {
 512                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 513                                       "for device 0.%x.%04x (ret=%d)\n",
 514                                       cdev->private->dev_id.ssid,
 515                                       cdev->private->dev_id.devno, ret);
 516                         return ret;
 517                 }
 518                 wait_event(cdev->private->wait_q,
 519                            cdev->private->flags.recog_done);
 520                 if (cdev->private->state != DEV_STATE_OFFLINE)
 521                         /* recognition failed */
 522                         return -EAGAIN;
 523         }
 524         if (cdev->drv && cdev->drv->set_online)
 525                 ccw_device_set_online(cdev);
 526         return 0;
 527 }
 528
 529 static int online_store_handle_online(struct ccw_device *cdev, int force)
 530 {
 531         int ret;
 532
 533         ret = online_store_recog_and_online(cdev);
 534         if (ret && !force)
 535                 return ret;
 536         if (force && cdev->private->state == DEV_STATE_BOXED) {
 537                 ret = ccw_device_stlck(cdev);
 538                 if (ret)
 539                         return ret;
 540                 if (cdev->id.cu_type == 0)
 541                         cdev->private->state = DEV_STATE_NOT_OPER;
 542                 ret = online_store_recog_and_online(cdev);
 543                 if (ret)
 544                         return ret;
 545         }
 546         return 0;
 547 }
 548
 549 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 550                              const char *buf, size_t count)
 551 {
 552         struct ccw_device *cdev = to_ccwdev(dev);
 553         int force, ret;
 554         unsigned long i;
 555
 556         if ((cdev->private->state != DEV_STATE_OFFLINE &&
 557              cdev->private->state != DEV_STATE_ONLINE &&
 558              cdev->private->state != DEV_STATE_BOXED &&
 559              cdev->private->state != DEV_STATE_DISCONNECTED) ||
 560             atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 561                 return -EAGAIN;
 562
 563         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 564                 atomic_set(&cdev->private->onoff, 0);
 565                 return -EINVAL;
 566         }
 567         if (!strncmp(buf, "force\n", count)) {
 568                 force = 1;
 569                 i = 1;
 570                 ret = 0;
 571         } else {
 572                 force = 0;
 573                 ret = strict_strtoul(buf, 16, &i);
 574         }
 575         if (ret)
 576                 goto out;
 577         switch (i) {
 578         case 0:
 579                 ret = online_store_handle_offline(cdev);
 580                 break;
 581         case 1:
 582                 ret = online_store_handle_online(cdev, force);
 583                 break;
 584         default:
 585                 ret = -EINVAL;
 586         }
 587 out:
 588         if (cdev->drv)
 589                 module_put(cdev->drv->owner);
 590         atomic_set(&cdev->private->onoff, 0);
 591         return (ret < 0) ? ret : count;
 592 }
 593
 594 static ssize_t
 595 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 596 {
 597         struct ccw_device *cdev = to_ccwdev(dev);
 598         struct subchannel *sch;
 599
 600         if (ccw_device_is_orphan(cdev))
 601                 return sprintf(buf, "no device\n");
 602         switch (cdev->private->state) {
 603         case DEV_STATE_BOXED:
 604                 return sprintf(buf, "boxed\n");
 605         case DEV_STATE_DISCONNECTED:
 606         case DEV_STATE_DISCONNECTED_SENSE_ID:
 607         case DEV_STATE_NOT_OPER:
 608                 sch = to_subchannel(dev->parent);
 609                 if (!sch->lpm)
 610                         return sprintf(buf, "no path\n");
 611                 else
 612                         return sprintf(buf, "no device\n");
 613         default:
 614                 /* All other states considered fine. */
 615                 return sprintf(buf, "good\n");
 616         }
 617 }
 618
 619 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 620 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 621 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 622 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 623 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 624 static DEVICE_ATTR(online, 0644, online_show, online_store);
 625 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 626
 627 static struct attribute *io_subchannel_attrs[] = {
 628         &dev_attr_chpids.attr,
 629         &dev_attr_pimpampom.attr,
 630         NULL,
 631 };
 632
 633 static struct attribute_group io_subchannel_attr_group = {
 634         .attrs = io_subchannel_attrs,
 635 };
 636
 637 static struct attribute * ccwdev_attrs[] = {
 638         &dev_attr_devtype.attr,
 639         &dev_attr_cutype.attr,
 640         &dev_attr_modalias.attr,
 641         &dev_attr_online.attr,
 642         &dev_attr_cmb_enable.attr,
 643         &dev_attr_availability.attr,
 644         NULL,
 645 };
 646
 647 static struct attribute_group ccwdev_attr_group = {
 648         .attrs = ccwdev_attrs,
 649 };
 650
 651 static const struct attribute_group *ccwdev_attr_groups[] = {
 652         &ccwdev_attr_group,
 653         NULL,
 654 };
 655
 656 /* this is a simple abstraction for device_register that sets the
 657  * correct bus type and adds the bus specific files */
 658 static int ccw_device_register(struct ccw_device *cdev)
 659 {
 660         struct device *dev = &cdev->dev;
 661         int ret;
 662
 663         dev->bus = &ccw_bus_type;
 664         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 665                            cdev->private->dev_id.devno);
 666         if (ret)
 667                 return ret;
 668         ret = device_add(dev);
 669         if (ret)
 670                 return ret;
 671
 672         set_bit(1, &cdev->private->registered);
 673         return ret;
 674 }
 675
 676 struct match_data {
 677         struct ccw_dev_id dev_id;
 678         struct ccw_device * sibling;
 679 };
 680
 681 static int
 682 match_devno(struct device * dev, void * data)
 683 {
 684         struct match_data * d = data;
 685         struct ccw_device * cdev;
 686
 687         cdev = to_ccwdev(dev);
 688         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 689             !ccw_device_is_orphan(cdev) &&
 690             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 691             (cdev != d->sibling))
 692                 return 1;
 693         return 0;
 694 }
 695
 696 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 697                                                      struct ccw_device *sibling)
 698 {
 699         struct device *dev;
 700         struct match_data data;
 701
 702         data.dev_id = *dev_id;
 703         data.sibling = sibling;
 704         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 705
 706         return dev ? to_ccwdev(dev) : NULL;
 707 }
 708
 709 static int match_orphan(struct device *dev, void *data)
 710 {
 711         struct ccw_dev_id *dev_id;
 712         struct ccw_device *cdev;
 713
 714         dev_id = data;
 715         cdev = to_ccwdev(dev);
 716         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 717 }
 718
 719 static struct ccw_device *
 720 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 721                               struct ccw_dev_id *dev_id)
 722 {
 723         struct device *dev;
 724
 725         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 726                                 match_orphan);
 727
 728         return dev ? to_ccwdev(dev) : NULL;
 729 }
 730
 731 void ccw_device_do_unbind_bind(struct work_struct *work)
 732 {
 733         struct ccw_device_private *priv;
 734         struct ccw_device *cdev;
 735         struct subchannel *sch;
 736         int ret;
 737
 738         priv = container_of(work, struct ccw_device_private, kick_work);
 739         cdev = priv->cdev;
 740         sch = to_subchannel(cdev->dev.parent);
 741
 742         if (test_bit(1, &cdev->private->registered)) {
 743                 device_release_driver(&cdev->dev);
 744                 ret = device_attach(&cdev->dev);
 745                 WARN_ON(ret == -ENODEV);
 746         }
 747 }
 748
 749 static void
 750 ccw_device_release(struct device *dev)
 751 {
 752         struct ccw_device *cdev;
 753
 754         cdev = to_ccwdev(dev);
 755         /* Release reference of parent subchannel. */
 756         put_device(cdev->dev.parent);
 757         kfree(cdev->private);
 758         kfree(cdev);
 759 }
 760
 761 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 762 {
 763         struct ccw_device *cdev;
 764
 765         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 766         if (cdev) {
 767                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 768                                         GFP_KERNEL | GFP_DMA);
 769                 if (cdev->private)
 770                         return cdev;
 771         }
 772         kfree(cdev);
 773         return ERR_PTR(-ENOMEM);
 774 }
 775
 776 static int io_subchannel_initialize_dev(struct subchannel *sch,
 777                                         struct ccw_device *cdev)
 778 {
 779         cdev->private->cdev = cdev;
 780         atomic_set(&cdev->private->onoff, 0);
 781         cdev->dev.parent = &sch->dev;
 782         cdev->dev.release = ccw_device_release;
 783         INIT_WORK(&cdev->private->kick_work, NULL);
 784         cdev->dev.groups = ccwdev_attr_groups;
 785         /* Do first half of device_register. */
 786         device_initialize(&cdev->dev);
 787         if (!get_device(&sch->dev)) {
 788                 /* Release reference from device_initialize(). */
 789                 put_device(&cdev->dev);
 790                 return -ENODEV;
 791         }
 792         return 0;
 793 }
 794
 795 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 796 {
 797         struct ccw_device *cdev;
 798         int ret;
 799
 800         cdev = io_subchannel_allocate_dev(sch);
 801         if (!IS_ERR(cdev)) {
 802                 ret = io_subchannel_initialize_dev(sch, cdev);
 803                 if (ret)
 804                         cdev = ERR_PTR(ret);
 805         }
 806         return cdev;
 807 }
 808
 809 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 810
 811 static void sch_attach_device(struct subchannel *sch,
 812                               struct ccw_device *cdev)
 813 {
 814         css_update_ssd_info(sch);
 815         spin_lock_irq(sch->lock);
 816         sch_set_cdev(sch, cdev);
 817         cdev->private->schid = sch->schid;
 818         cdev->ccwlock = sch->lock;
 819         ccw_device_trigger_reprobe(cdev);
 820         spin_unlock_irq(sch->lock);
 821 }
 822
 823 static void sch_attach_disconnected_device(struct subchannel *sch,
 824                                            struct ccw_device *cdev)
 825 {
 826         struct subchannel *other_sch;
 827         int ret;
 828
 829         /* Get reference for new parent. */
 830         if (!get_device(&sch->dev))
 831                 return;
 832         other_sch = to_subchannel(cdev->dev.parent);
 833         /* Note: device_move() changes cdev->dev.parent */
 834         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 835         if (ret) {
 836                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 837                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 838                               cdev->private->dev_id.devno, ret);
 839                 /* Put reference for new parent. */
 840                 put_device(&sch->dev);
 841                 return;
 842         }
 843         sch_set_cdev(other_sch, NULL);
 844         /* No need to keep a subchannel without ccw device around. */
 845         css_sch_device_unregister(other_sch);
 846         sch_attach_device(sch, cdev);
 847         /* Put reference for old parent. */
 848         put_device(&other_sch->dev);
 849 }
 850
 851 static void sch_attach_orphaned_device(struct subchannel *sch,
 852                                        struct ccw_device *cdev)
 853 {
 854         int ret;
 855         struct subchannel *pseudo_sch;
 856
 857         /* Get reference for new parent. */
 858         if (!get_device(&sch->dev))
 859                 return;
 860         pseudo_sch = to_subchannel(cdev->dev.parent);
 861         /*
 862          * Try to move the ccw device to its new subchannel.
 863          * Note: device_move() changes cdev->dev.parent
 864          */
 865         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 866         if (ret) {
 867                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 868                               "failed (ret=%d)!\n",
 869                               cdev->private->dev_id.ssid,
 870                               cdev->private->dev_id.devno, ret);
 871                 /* Put reference for new parent. */
 872                 put_device(&sch->dev);
 873                 return;
 874         }
 875         sch_attach_device(sch, cdev);
 876         /* Put reference on pseudo subchannel. */
 877         put_device(&pseudo_sch->dev);
 878 }
 879
 880 static void sch_create_and_recog_new_device(struct subchannel *sch)
 881 {
 882         struct ccw_device *cdev;
 883
 884         /* Need to allocate a new ccw device. */
 885         cdev = io_subchannel_create_ccwdev(sch);
 886         if (IS_ERR(cdev)) {
 887                 /* OK, we did everything we could... */
 888                 css_sch_device_unregister(sch);
 889                 return;
 890         }
 891         /* Start recognition for the new ccw device. */
 892         if (io_subchannel_recog(cdev, sch)) {
 893                 spin_lock_irq(sch->lock);
 894                 sch_set_cdev(sch, NULL);
 895                 spin_unlock_irq(sch->lock);
 896                 css_sch_device_unregister(sch);
 897                 /* Put reference from io_subchannel_create_ccwdev(). */
 898                 put_device(&sch->dev);
 899                 /* Give up initial reference. */
 900                 put_device(&cdev->dev);
 901         }
 902 }
 903
 904
 905 void ccw_device_move_to_orphanage(struct work_struct *work)
 906 {
 907         struct ccw_device_private *priv;
 908         struct ccw_device *cdev;
 909         struct ccw_device *replacing_cdev;
 910         struct subchannel *sch;
 911         int ret;
 912         struct channel_subsystem *css;
 913         struct ccw_dev_id dev_id;
 914
 915         priv = container_of(work, struct ccw_device_private, kick_work);
 916         cdev = priv->cdev;
 917         sch = to_subchannel(cdev->dev.parent);
 918         css = to_css(sch->dev.parent);
 919         dev_id.devno = sch->schib.pmcw.dev;
 920         dev_id.ssid = sch->schid.ssid;
 921
 922         /* Increase refcount for pseudo subchannel. */
 923         get_device(&css->pseudo_subchannel->dev);
 924         /*
 925          * Move the orphaned ccw device to the orphanage so the replacing
 926          * ccw device can take its place on the subchannel.
 927          * Note: device_move() changes cdev->dev.parent
 928          */
 929         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev,
 930                 DPM_ORDER_NONE);
 931         if (ret) {
 932                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 933                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 934                               cdev->private->dev_id.devno, ret);
 935                 /* Decrease refcount for pseudo subchannel again. */
 936                 put_device(&css->pseudo_subchannel->dev);
 937                 return;
 938         }
 939         cdev->ccwlock = css->pseudo_subchannel->lock;
 940         /*
 941          * Search for the replacing ccw device
 942          * - among the disconnected devices
 943          * - in the orphanage
 944          */
 945         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 946         if (replacing_cdev) {
 947                 sch_attach_disconnected_device(sch, replacing_cdev);
 948                 /* Release reference from get_disc_ccwdev_by_dev_id() */
 949                 put_device(&replacing_cdev->dev);
 950                 /* Release reference of subchannel from old cdev. */
 951                 put_device(&sch->dev);
 952                 return;
 953         }
 954         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 955         if (replacing_cdev) {
 956                 sch_attach_orphaned_device(sch, replacing_cdev);
 957                 /* Release reference from get_orphaned_ccwdev_by_dev_id() */
 958                 put_device(&replacing_cdev->dev);
 959                 /* Release reference of subchannel from old cdev. */
 960                 put_device(&sch->dev);
 961                 return;
 962         }
 963         sch_create_and_recog_new_device(sch);
 964         /* Release reference of subchannel from old cdev. */
 965         put_device(&sch->dev);
 966 }
 967
 968 /*
 969  * Register recognized device.
 970  */
 971 static void
 972 io_subchannel_register(struct work_struct *work)
 973 {
 974         struct ccw_device_private *priv;
 975         struct ccw_device *cdev;
 976         struct subchannel *sch;
 977         int ret;
 978         unsigned long flags;
 979
 980         priv = container_of(work, struct ccw_device_private, kick_work);
 981         cdev = priv->cdev;
 982         sch = to_subchannel(cdev->dev.parent);
 983         /*
 984          * Check if subchannel is still registered. It may have become
 985          * unregistered if a machine check hit us after finishing
 986          * device recognition but before the register work could be
 987          * queued.
 988          */
 989         if (!device_is_registered(&sch->dev))
 990                 goto out_err;
 991         css_update_ssd_info(sch);
 992         /*
 993          * io_subchannel_register() will also be called after device
 994          * recognition has been done for a boxed device (which will already
 995          * be registered). We need to reprobe since we may now have sense id
 996          * information.
 997          */
 998         if (device_is_registered(&cdev->dev)) {
 999                 if (!cdev->drv) {
1000                         ret = device_reprobe(&cdev->dev);
1001                         if (ret)
1002                                 /* We can't do much here. */
1003                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
1004                                               " %d for 0.%x.%04x\n", ret,
1005                                               cdev->private->dev_id.ssid,
1006                                               cdev->private->dev_id.devno);
1007                 }
1008                 goto out;
1009         }
1010         /*
1011          * Now we know this subchannel will stay, we can throw
1012          * our delayed uevent.
1013          */
1014         dev_set_uevent_suppress(&sch->dev, 0);
1015         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1016         /* make it known to the system */
1017         ret = ccw_device_register(cdev);
1018         if (ret) {
1019                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
1020                               cdev->private->dev_id.ssid,
1021                               cdev->private->dev_id.devno, ret);
1022                 spin_lock_irqsave(sch->lock, flags);
1023                 sch_set_cdev(sch, NULL);
1024                 spin_unlock_irqrestore(sch->lock, flags);
1025                 /* Release initial device reference. */
1026                 put_device(&cdev->dev);
1027                 goto out_err;
1028         }
1029 out:
1030         cdev->private->flags.recog_done = 1;
1031         wake_up(&cdev->private->wait_q);
1032 out_err:
1033         /* Release reference for workqueue processing. */
1034         put_device(&cdev->dev);
1035         if (atomic_dec_and_test(&ccw_device_init_count))
1036                 wake_up(&ccw_device_init_wq);
1037 }
1038
1039 static void ccw_device_call_sch_unregister(struct work_struct *work)
1040 {
1041         struct ccw_device_private *priv;
1042         struct ccw_device *cdev;
1043         struct subchannel *sch;
1044
1045         priv = container_of(work, struct ccw_device_private, kick_work);
1046         cdev = priv->cdev;
1047         /* Get subchannel reference for local processing. */
1048         if (!get_device(cdev->dev.parent))
1049                 return;
1050         sch = to_subchannel(cdev->dev.parent);
1051         css_sch_device_unregister(sch);
1052         /* Release cdev reference for workqueue processing.*/
1053         put_device(&cdev->dev);
1054         /* Release subchannel reference for local processing. */
1055         put_device(&sch->dev);
1056 }
1057
1058 void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
1059 {
1060         /* Get cdev reference for workqueue processing. */
1061         if (!get_device(&cdev->dev))
1062                 return;
1063         PREPARE_WORK(&cdev->private->kick_work,
1064                      ccw_device_call_sch_unregister);
1065         queue_work(slow_path_wq, &cdev->private->kick_work);
1066 }
1067
1068 /*
1069  * subchannel recognition done. Called from the state machine.
1070  */
1071 void
1072 io_subchannel_recog_done(struct ccw_device *cdev)
1073 {
1074         if (css_init_done == 0) {
1075                 cdev->private->flags.recog_done = 1;
1076                 return;
1077         }
1078         switch (cdev->private->state) {
1079         case DEV_STATE_BOXED:
1080                 /* Device did not respond in time. */
1081         case DEV_STATE_NOT_OPER:
1082                 cdev->private->flags.recog_done = 1;
1083                 ccw_device_schedule_sch_unregister(cdev);
1084                 if (atomic_dec_and_test(&ccw_device_init_count))
1085                         wake_up(&ccw_device_init_wq);
1086                 break;
1087         case DEV_STATE_OFFLINE:
1088                 /*
1089                  * We can't register the device in interrupt context so
1090                  * we schedule a work item.
1091                  */
1092                 if (!get_device(&cdev->dev))
1093                         break;
1094                 PREPARE_WORK(&cdev->private->kick_work,
1095                              io_subchannel_register);
1096                 queue_work(slow_path_wq, &cdev->private->kick_work);
1097                 break;
1098         }
1099 }
1100
1101 static int
1102 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1103 {
1104         int rc;
1105         struct ccw_device_private *priv;
1106
1107         cdev->ccwlock = sch->lock;
1108
1109         /* Init private data. */
1110         priv = cdev->private;
1111         priv->dev_id.devno = sch->schib.pmcw.dev;
1112         priv->dev_id.ssid = sch->schid.ssid;
1113         priv->schid = sch->schid;
1114         priv->state = DEV_STATE_NOT_OPER;
1115         INIT_LIST_HEAD(&priv->cmb_list);
1116         init_waitqueue_head(&priv->wait_q);
1117         init_timer(&priv->timer);
1118
1119         /* Increase counter of devices currently in recognition. */
1120         atomic_inc(&ccw_device_init_count);
1121
1122         /* Start async. device sensing. */
1123         spin_lock_irq(sch->lock);
1124         sch_set_cdev(sch, cdev);
1125         rc = ccw_device_recognition(cdev);
1126         spin_unlock_irq(sch->lock);
1127         if (rc) {
1128                 if (atomic_dec_and_test(&ccw_device_init_count))
1129                         wake_up(&ccw_device_init_wq);
1130         }
1131         return rc;
1132 }
1133
1134 static void ccw_device_move_to_sch(struct work_struct *work)
1135 {
1136         struct ccw_device_private *priv;
1137         int rc;
1138         struct subchannel *sch;
1139         struct ccw_device *cdev;
1140         struct subchannel *former_parent;
1141
1142         priv = container_of(work, struct ccw_device_private, kick_work);
1143         sch = priv->sch;
1144         cdev = priv->cdev;
1145         former_parent = to_subchannel(cdev->dev.parent);
1146         /* Get reference for new parent. */
1147         if (!get_device(&sch->dev))
1148                 return;
1149         mutex_lock(&sch->reg_mutex);
1150         /*
1151          * Try to move the ccw device to its new subchannel.
1152          * Note: device_move() changes cdev->dev.parent
1153          */
1154         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
1155         mutex_unlock(&sch->reg_mutex);
1156         if (rc) {
1157                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1158                               "0.%x.%04x failed (ret=%d)!\n",
1159                               cdev->private->dev_id.ssid,
1160                               cdev->private->dev_id.devno, sch->schid.ssid,
1161                               sch->schid.sch_no, rc);
1162                 css_sch_device_unregister(sch);
1163                 /* Put reference for new parent again. */
1164                 put_device(&sch->dev);
1165                 goto out;
1166         }
1167         if (!sch_is_pseudo_sch(former_parent)) {
1168                 spin_lock_irq(former_parent->lock);
1169                 sch_set_cdev(former_parent, NULL);
1170                 spin_unlock_irq(former_parent->lock);
1171                 css_sch_device_unregister(former_parent);
1172                 /* Reset intparm to zeroes. */
1173                 former_parent->config.intparm = 0;
1174                 cio_commit_config(former_parent);
1175         }
1176         sch_attach_device(sch, cdev);
1177 out:
1178         /* Put reference for old parent. */
1179         put_device(&former_parent->dev);
1180         put_device(&cdev->dev);
1181 }
1182
1183 static void io_subchannel_irq(struct subchannel *sch)
1184 {
1185         struct ccw_device *cdev;
1186
1187         cdev = sch_get_cdev(sch);
1188
1189         CIO_TRACE_EVENT(6, "IRQ");
1190         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1191         if (cdev)
1192                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1193 }
1194
1195 void io_subchannel_init_config(struct subchannel *sch)
1196 {
1197         memset(&sch->config, 0, sizeof(sch->config));
1198         sch->config.csense = 1;
1199         /* Use subchannel mp mode when there is more than 1 installed CHPID. */
1200         if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
1201                 sch->config.mp = 1;
1202 }
1203
1204 static void io_subchannel_init_fields(struct subchannel *sch)
1205 {
1206         if (cio_is_console(sch->schid))
1207                 sch->opm = 0xff;
1208         else
1209                 sch->opm = chp_get_sch_opm(sch);
1210         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1211         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1212
1213         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1214                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1215                       sch->schib.pmcw.dev, sch->schid.ssid,
1216                       sch->schid.sch_no, sch->schib.pmcw.pim,
1217                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1218
1219         io_subchannel_init_config(sch);
1220 }
1221
1222 static void io_subchannel_do_unreg(struct work_struct *work)
1223 {
1224         struct subchannel *sch;
1225
1226         sch = container_of(work, struct subchannel, work);
1227         css_sch_device_unregister(sch);
1228         put_device(&sch->dev);
1229 }
1230
1231 /* Schedule unregister if we have no cdev. */
1232 static void io_subchannel_schedule_removal(struct subchannel *sch)
1233 {
1234         get_device(&sch->dev);
1235         INIT_WORK(&sch->work, io_subchannel_do_unreg);
1236         queue_work(slow_path_wq, &sch->work);
1237 }
1238
1239 /*
1240  * Note: We always return 0 so that we bind to the device even on error.
1241  * This is needed so that our remove function is called on unregister.
1242  */
1243 static int io_subchannel_probe(struct subchannel *sch)
1244 {
1245         struct ccw_device *cdev;
1246         int rc;
1247         unsigned long flags;
1248         struct ccw_dev_id dev_id;
1249
1250         if (cio_is_console(sch->schid)) {
1251                 rc = sysfs_create_group(&sch->dev.kobj,
1252                                         &io_subchannel_attr_group);
1253                 if (rc)
1254                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1255                                       "attributes for subchannel "
1256                                       "0.%x.%04x (rc=%d)\n",
1257                                       sch->schid.ssid, sch->schid.sch_no, rc);
1258                 /*
1259                  * The console subchannel already has an associated ccw_device.
1260                  * Throw the delayed uevent for the subchannel, register
1261                  * the ccw_device and exit.
1262                  */
1263                 dev_set_uevent_suppress(&sch->dev, 0);
1264                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1265                 cdev = sch_get_cdev(sch);
1266                 cdev->dev.groups = ccwdev_attr_groups;
1267                 device_initialize(&cdev->dev);
1268                 ccw_device_register(cdev);
1269                 /*
1270                  * Check if the device is already online. If it is
1271                  * the reference count needs to be corrected since we
1272                  * didn't obtain a reference in ccw_device_set_online.
1273                  */
1274                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1275                     cdev->private->state != DEV_STATE_OFFLINE &&
1276                     cdev->private->state != DEV_STATE_BOXED)
1277                         get_device(&cdev->dev);
1278                 return 0;
1279         }
1280         io_subchannel_init_fields(sch);
1281         rc = cio_commit_config(sch);
1282         if (rc)
1283                 goto out_schedule;
1284         rc = sysfs_create_group(&sch->dev.kobj,
1285                                 &io_subchannel_attr_group);
1286         if (rc)
1287                 goto out_schedule;
1288         /* Allocate I/O subchannel private data. */
1289         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1290                                GFP_KERNEL | GFP_DMA);
1291         if (!sch->private)
1292                 goto out_schedule;
1293         /*
1294          * First check if a fitting device may be found amongst the
1295          * disconnected devices or in the orphanage.
1296          */
1297         dev_id.devno = sch->schib.pmcw.dev;
1298         dev_id.ssid = sch->schid.ssid;
1299         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1300         if (!cdev)
1301                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1302                                                      &dev_id);
1303         if (cdev) {
1304                 /*
1305                  * Schedule moving the device until when we have a registered
1306                  * subchannel to move to and succeed the probe. We can
1307                  * unregister later again, when the probe is through.
1308                  */
1309                 cdev->private->sch = sch;
1310                 PREPARE_WORK(&cdev->private->kick_work,
1311                              ccw_device_move_to_sch);
1312                 queue_work(slow_path_wq, &cdev->private->kick_work);
1313                 return 0;
1314         }
1315         cdev = io_subchannel_create_ccwdev(sch);
1316         if (IS_ERR(cdev))
1317                 goto out_schedule;
1318         rc = io_subchannel_recog(cdev, sch);
1319         if (rc) {
1320                 spin_lock_irqsave(sch->lock, flags);
1321                 io_subchannel_recog_done(cdev);
1322                 spin_unlock_irqrestore(sch->lock, flags);
1323         }
1324         return 0;
1325
1326 out_schedule:
1327         io_subchannel_schedule_removal(sch);
1328         return 0;
1329 }
1330
1331 static int
1332 io_subchannel_remove (struct subchannel *sch)
1333 {
1334         struct ccw_device *cdev;
1335         unsigned long flags;
1336
1337         cdev = sch_get_cdev(sch);
1338         if (!cdev)
1339                 goto out_free;
1340         /* Set ccw device to not operational and drop reference. */
1341         spin_lock_irqsave(cdev->ccwlock, flags);
1342         sch_set_cdev(sch, NULL);
1343         cdev->private->state = DEV_STATE_NOT_OPER;
1344         spin_unlock_irqrestore(cdev->ccwlock, flags);
1345         ccw_device_unregister(cdev);
1346 out_free:
1347         kfree(sch->private);
1348         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1349         return 0;
1350 }
1351
1352 static int io_subchannel_notify(struct subchannel *sch, int event)
1353 {
1354         struct ccw_device *cdev;
1355
1356         cdev = sch_get_cdev(sch);
1357         if (!cdev)
1358                 return 0;
1359         return ccw_device_notify(cdev, event);
1360 }
1361
1362 static void io_subchannel_verify(struct subchannel *sch)
1363 {
1364         struct ccw_device *cdev;
1365
1366         cdev = sch_get_cdev(sch);
1367         if (cdev)
1368                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1369 }
1370
1371 static int check_for_io_on_path(struct subchannel *sch, int mask)
1372 {
1373         if (cio_update_schib(sch))
1374                 return 0;
1375         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1376                 return 1;
1377         return 0;
1378 }
1379
1380 static void terminate_internal_io(struct subchannel *sch,
1381                                   struct ccw_device *cdev)
1382 {
1383         if (cio_clear(sch)) {
1384                 /* Recheck device in case clear failed. */
1385                 sch->lpm = 0;
1386                 if (cdev->online)
1387                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1388                 else
1389                         css_schedule_eval(sch->schid);
1390                 return;
1391         }
1392         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1393         /* Request retry of internal operation. */
1394         cdev->private->flags.intretry = 1;
1395         /* Call handler. */
1396         if (cdev->handler)
1397                 cdev->handler(cdev, cdev->private->intparm,
1398                               ERR_PTR(-EIO));
1399 }
1400
1401 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1402 {
1403         struct ccw_device *cdev;
1404
1405         cdev = sch_get_cdev(sch);
1406         if (!cdev)
1407                 return;
1408         if (check_for_io_on_path(sch, mask)) {
1409                 if (cdev->private->state == DEV_STATE_ONLINE)
1410                         ccw_device_kill_io(cdev);
1411                 else {
1412                         terminate_internal_io(sch, cdev);
1413                         /* Re-start path verification. */
1414                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1415                 }
1416         } else
1417                 /* trigger path verification. */
1418                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1419
1420 }
1421
1422 static int io_subchannel_chp_event(struct subchannel *sch,
1423                                    struct chp_link *link, int event)
1424 {
1425         int mask;
1426
1427         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1428         if (!mask)
1429                 return 0;
1430         switch (event) {
1431         case CHP_VARY_OFF:
1432                 sch->opm &= ~mask;
1433                 sch->lpm &= ~mask;
1434                 io_subchannel_terminate_path(sch, mask);
1435                 break;
1436         case CHP_VARY_ON:
1437                 sch->opm |= mask;
1438                 sch->lpm |= mask;
1439                 io_subchannel_verify(sch);
1440                 break;
1441         case CHP_OFFLINE:
1442                 if (cio_update_schib(sch))
1443                         return -ENODEV;
1444                 io_subchannel_terminate_path(sch, mask);
1445                 break;
1446         case CHP_ONLINE:
1447                 if (cio_update_schib(sch))
1448                         return -ENODEV;
1449                 sch->lpm |= mask & sch->opm;
1450                 io_subchannel_verify(sch);
1451                 break;
1452         }
1453         return 0;
1454 }
1455
1456 static void
1457 io_subchannel_shutdown(struct subchannel *sch)
1458 {
1459         struct ccw_device *cdev;
1460         int ret;
1461
1462         cdev = sch_get_cdev(sch);
1463
1464         if (cio_is_console(sch->schid))
1465                 return;
1466         if (!sch->schib.pmcw.ena)
1467                 /* Nothing to do. */
1468                 return;
1469         ret = cio_disable_subchannel(sch);
1470         if (ret != -EBUSY)
1471                 /* Subchannel is disabled, we're done. */
1472                 return;
1473         cdev->private->state = DEV_STATE_QUIESCE;
1474         if (cdev->handler)
1475                 cdev->handler(cdev, cdev->private->intparm,
1476                               ERR_PTR(-EIO));
1477         ret = ccw_device_cancel_halt_clear(cdev);
1478         if (ret == -EBUSY) {
1479                 ccw_device_set_timeout(cdev, HZ/10);
1480                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1481         }
1482         cio_disable_subchannel(sch);
1483 }
1484
1485 static int io_subchannel_get_status(struct subchannel *sch)
1486 {
1487         struct schib schib;
1488
1489         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1490                 return CIO_GONE;
1491         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1492                 return CIO_REVALIDATE;
1493         if (!sch->lpm)
1494                 return CIO_NO_PATH;
1495         return CIO_OPER;
1496 }
1497
1498 static int device_is_disconnected(struct ccw_device *cdev)
1499 {
1500         if (!cdev)
1501                 return 0;
1502         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1503                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1504 }
1505
1506 static int recovery_check(struct device *dev, void *data)
1507 {
1508         struct ccw_device *cdev = to_ccwdev(dev);
1509         int *redo = data;
1510
1511         spin_lock_irq(cdev->ccwlock);
1512         switch (cdev->private->state) {
1513         case DEV_STATE_DISCONNECTED:
1514                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1515                               cdev->private->dev_id.ssid,
1516                               cdev->private->dev_id.devno);
1517                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1518                 *redo = 1;
1519                 break;
1520         case DEV_STATE_DISCONNECTED_SENSE_ID:
1521                 *redo = 1;
1522                 break;
1523         }
1524         spin_unlock_irq(cdev->ccwlock);
1525
1526         return 0;
1527 }
1528
1529 static void recovery_work_func(struct work_struct *unused)
1530 {
1531         int redo = 0;
1532
1533         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1534         if (redo) {
1535                 spin_lock_irq(&recovery_lock);
1536                 if (!timer_pending(&recovery_timer)) {
1537                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1538                                 recovery_phase++;
1539                         mod_timer(&recovery_timer, jiffies +
1540                                   recovery_delay[recovery_phase] * HZ);
1541                 }
1542                 spin_unlock_irq(&recovery_lock);
1543         } else
1544                 CIO_MSG_EVENT(4, "recovery: end\n");
1545 }
1546
1547 static DECLARE_WORK(recovery_work, recovery_work_func);
1548
1549 static void recovery_func(unsigned long data)
1550 {
1551         /*
1552          * We can't do our recovery in softirq context and it's not
1553          * performance critical, so we schedule it.
1554          */
1555         schedule_work(&recovery_work);
1556 }
1557
1558 static void ccw_device_schedule_recovery(void)
1559 {
1560         unsigned long flags;
1561
1562         CIO_MSG_EVENT(4, "recovery: schedule\n");
1563         spin_lock_irqsave(&recovery_lock, flags);
1564         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1565                 recovery_phase = 0;
1566                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1567         }
1568         spin_unlock_irqrestore(&recovery_lock, flags);
1569 }
1570
1571 static int purge_fn(struct device *dev, void *data)
1572 {
1573         struct ccw_device *cdev = to_ccwdev(dev);
1574         struct ccw_device_private *priv = cdev->private;
1575         int unreg;
1576
1577         spin_lock_irq(cdev->ccwlock);
1578         unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1579                 (priv->state == DEV_STATE_OFFLINE);
1580         spin_unlock_irq(cdev->ccwlock);
1581         if (!unreg)
1582                 goto out;
1583         CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1584                       priv->dev_id.devno);
1585         ccw_device_schedule_sch_unregister(cdev);
1586
1587 out:
1588         /* Abort loop in case of pending signal. */
1589         if (signal_pending(current))
1590                 return -EINTR;
1591
1592         return 0;
1593 }
1594
1595 /**
1596  * ccw_purge_blacklisted - purge unused, blacklisted devices
1597  *
1598  * Unregister all ccw devices that are offline and on the blacklist.
1599  */
1600 int ccw_purge_blacklisted(void)
1601 {
1602         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1603         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1604         return 0;
1605 }
1606
1607 void ccw_device_set_disconnected(struct ccw_device *cdev)
1608 {
1609         if (!cdev)
1610                 return;
1611         ccw_device_set_timeout(cdev, 0);
1612         cdev->private->flags.fake_irb = 0;
1613         cdev->private->state = DEV_STATE_DISCONNECTED;
1614         if (cdev->online)
1615                 ccw_device_schedule_recovery();
1616 }
1617
1618 void ccw_device_set_notoper(struct ccw_device *cdev)
1619 {
1620         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1621
1622         CIO_TRACE_EVENT(2, "notoper");
1623         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1624         ccw_device_set_timeout(cdev, 0);
1625         cio_disable_subchannel(sch);
1626         cdev->private->state = DEV_STATE_NOT_OPER;
1627 }
1628
1629 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1630 {
1631         int event, ret, disc;
1632         unsigned long flags;
1633         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1634         struct ccw_device *cdev;
1635
1636         spin_lock_irqsave(sch->lock, flags);
1637         cdev = sch_get_cdev(sch);
1638         disc = device_is_disconnected(cdev);
1639         if (disc && slow) {
1640                 /* Disconnected devices are evaluated directly only.*/
1641                 spin_unlock_irqrestore(sch->lock, flags);
1642                 return 0;
1643         }
1644         /* No interrupt after machine check - kill pending timers. */
1645         if (cdev)
1646                 ccw_device_set_timeout(cdev, 0);
1647         if (!disc && !slow) {
1648                 /* Non-disconnected devices are evaluated on the slow path. */
1649                 spin_unlock_irqrestore(sch->lock, flags);
1650                 return -EAGAIN;
1651         }
1652         event = io_subchannel_get_status(sch);
1653         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1654                       sch->schid.ssid, sch->schid.sch_no, event,
1655                       disc ? "disconnected" : "normal",
1656                       slow ? "slow" : "fast");
1657         /* Analyze subchannel status. */
1658         action = NONE;
1659         switch (event) {
1660         case CIO_NO_PATH:
1661                 if (disc) {
1662                         /* Check if paths have become available. */
1663                         action = REPROBE;
1664                         break;
1665                 }
1666                 /* fall through */
1667         case CIO_GONE:
1668                 /* Ask driver what to do with device. */
1669                 if (io_subchannel_notify(sch, event))
1670                         action = DISC;
1671                 else
1672                         action = UNREGISTER;
1673                 break;
1674         case CIO_REVALIDATE:
1675                 /* Device will be removed, so no notify necessary. */
1676                 if (disc)
1677                         /* Reprobe because immediate unregister might block. */
1678                         action = REPROBE;
1679                 else
1680                         action = UNREGISTER_PROBE;
1681                 break;
1682         case CIO_OPER:
1683                 if (disc)
1684                         /* Get device operational again. */
1685                         action = REPROBE;
1686                 break;
1687         }
1688         /* Perform action. */
1689         ret = 0;
1690         switch (action) {
1691         case UNREGISTER:
1692         case UNREGISTER_PROBE:
1693                 ccw_device_set_notoper(cdev);
1694                 /* Unregister device (will use subchannel lock). */
1695                 spin_unlock_irqrestore(sch->lock, flags);
1696                 css_sch_device_unregister(sch);
1697                 spin_lock_irqsave(sch->lock, flags);
1698                 break;
1699         case REPROBE:
1700                 ccw_device_trigger_reprobe(cdev);
1701                 break;
1702         case DISC:
1703                 ccw_device_set_disconnected(cdev);
1704                 break;
1705         default:
1706                 break;
1707         }
1708         spin_unlock_irqrestore(sch->lock, flags);
1709         /* Probe if necessary. */
1710         if (action == UNREGISTER_PROBE)
1711                 ret = css_probe_device(sch->schid);
1712
1713         return ret;
1714 }
1715
1716 #ifdef CONFIG_CCW_CONSOLE
1717 static struct ccw_device console_cdev;
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 #endif
1802
1803 /*
1804  * get ccw_device matching the busid, but only if owned by cdrv
1805  */
1806 static int
1807 __ccwdev_check_busid(struct device *dev, void *id)
1808 {
1809         char *bus_id;
1810
1811         bus_id = id;
1812
1813         return (strcmp(bus_id, dev_name(dev)) == 0);
1814 }
1815
1816
1817 /**
1818  * get_ccwdev_by_busid() - obtain device from a bus id
1819  * @cdrv: driver the device is owned by
1820  * @bus_id: bus id of the device to be searched
1821  *
1822  * This function searches all devices owned by @cdrv for a device with a bus
1823  * id matching @bus_id.
1824  * Returns:
1825  *  If a match is found, its reference count of the found device is increased
1826  *  and it is returned; else %NULL is returned.
1827  */
1828 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1829                                        const char *bus_id)
1830 {
1831         struct device *dev;
1832         struct device_driver *drv;
1833
1834         drv = get_driver(&cdrv->driver);
1835         if (!drv)
1836                 return NULL;
1837
1838         dev = driver_find_device(drv, NULL, (void *)bus_id,
1839                                  __ccwdev_check_busid);
1840         put_driver(drv);
1841
1842         return dev ? to_ccwdev(dev) : NULL;
1843 }
1844
1845 /************************** device driver handling ************************/
1846
1847 /* This is the implementation of the ccw_driver class. The probe, remove
1848  * and release methods are initially very similar to the device_driver
1849  * implementations, with the difference that they have ccw_device
1850  * arguments.
1851  *
1852  * A ccw driver also contains the information that is needed for
1853  * device matching.
1854  */
1855 static int
1856 ccw_device_probe (struct device *dev)
1857 {
1858         struct ccw_device *cdev = to_ccwdev(dev);
1859         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1860         int ret;
1861
1862         cdev->drv = cdrv; /* to let the driver call _set_online */
1863
1864         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1865
1866         if (ret) {
1867                 cdev->drv = NULL;
1868                 return ret;
1869         }
1870
1871         return 0;
1872 }
1873
1874 static int
1875 ccw_device_remove (struct device *dev)
1876 {
1877         struct ccw_device *cdev = to_ccwdev(dev);
1878         struct ccw_driver *cdrv = cdev->drv;
1879         int ret;
1880
1881         if (cdrv->remove)
1882                 cdrv->remove(cdev);
1883         if (cdev->online) {
1884                 cdev->online = 0;
1885                 spin_lock_irq(cdev->ccwlock);
1886                 ret = ccw_device_offline(cdev);
1887                 spin_unlock_irq(cdev->ccwlock);
1888                 if (ret == 0)
1889                         wait_event(cdev->private->wait_q,
1890                                    dev_fsm_final_state(cdev));
1891                 else
1892                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1893                                       "device 0.%x.%04x\n",
1894                                       ret, cdev->private->dev_id.ssid,
1895                                       cdev->private->dev_id.devno);
1896                 /* Give up reference obtained in ccw_device_set_online(). */
1897                 put_device(&cdev->dev);
1898         }
1899         ccw_device_set_timeout(cdev, 0);
1900         cdev->drv = NULL;
1901         return 0;
1902 }
1903
1904 static void ccw_device_shutdown(struct device *dev)
1905 {
1906         struct ccw_device *cdev;
1907
1908         cdev = to_ccwdev(dev);
1909         if (cdev->drv && cdev->drv->shutdown)
1910                 cdev->drv->shutdown(cdev);
1911         disable_cmf(cdev);
1912 }
1913
1914 static int ccw_device_pm_prepare(struct device *dev)
1915 {
1916         struct ccw_device *cdev = to_ccwdev(dev);
1917
1918         if (work_pending(&cdev->private->kick_work))
1919                 return -EAGAIN;
1920         /* Fail while device is being set online/offline. */
1921         if (atomic_read(&cdev->private->onoff))
1922                 return -EAGAIN;
1923
1924         if (cdev->online && cdev->drv && cdev->drv->prepare)
1925                 return cdev->drv->prepare(cdev);
1926
1927         return 0;
1928 }
1929
1930 static void ccw_device_pm_complete(struct device *dev)
1931 {
1932         struct ccw_device *cdev = to_ccwdev(dev);
1933
1934         if (cdev->online && cdev->drv && cdev->drv->complete)
1935                 cdev->drv->complete(cdev);
1936 }
1937
1938 static int ccw_device_pm_freeze(struct device *dev)
1939 {
1940         struct ccw_device *cdev = to_ccwdev(dev);
1941         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1942         int ret, cm_enabled;
1943
1944         /* Fail suspend while device is in transistional state. */
1945         if (!dev_fsm_final_state(cdev))
1946                 return -EAGAIN;
1947         if (!cdev->online)
1948                 return 0;
1949         if (cdev->drv && cdev->drv->freeze) {
1950                 ret = cdev->drv->freeze(cdev);
1951                 if (ret)
1952                         return ret;
1953         }
1954
1955         spin_lock_irq(sch->lock);
1956         cm_enabled = cdev->private->cmb != NULL;
1957         spin_unlock_irq(sch->lock);
1958         if (cm_enabled) {
1959                 /* Don't have the css write on memory. */
1960                 ret = ccw_set_cmf(cdev, 0);
1961                 if (ret)
1962                         return ret;
1963         }
1964         /* From here on, disallow device driver I/O. */
1965         spin_lock_irq(sch->lock);
1966         ret = cio_disable_subchannel(sch);
1967         spin_unlock_irq(sch->lock);
1968
1969         return ret;
1970 }
1971
1972 static int ccw_device_pm_thaw(struct device *dev)
1973 {
1974         struct ccw_device *cdev = to_ccwdev(dev);
1975         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1976         int ret, cm_enabled;
1977
1978         if (!cdev->online)
1979                 return 0;
1980
1981         spin_lock_irq(sch->lock);
1982         /* Allow device driver I/O again. */
1983         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1984         cm_enabled = cdev->private->cmb != NULL;
1985         spin_unlock_irq(sch->lock);
1986         if (ret)
1987                 return ret;
1988
1989         if (cm_enabled) {
1990                 ret = ccw_set_cmf(cdev, 1);
1991                 if (ret)
1992                         return ret;
1993         }
1994
1995         if (cdev->drv && cdev->drv->thaw)
1996                 ret = cdev->drv->thaw(cdev);
1997
1998         return ret;
1999 }
2000
2001 static void __ccw_device_pm_restore(struct ccw_device *cdev)
2002 {
2003         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2004         int ret;
2005
2006         if (cio_is_console(sch->schid))
2007                 goto out;
2008         /*
2009          * While we were sleeping, devices may have gone or become
2010          * available again. Kick re-detection.
2011          */
2012         spin_lock_irq(sch->lock);
2013         cdev->private->flags.resuming = 1;
2014         ret = ccw_device_recognition(cdev);
2015         spin_unlock_irq(sch->lock);
2016         if (ret) {
2017                 CIO_MSG_EVENT(0, "Couldn't start recognition for device "
2018                               "0.%x.%04x (ret=%d)\n",
2019                               cdev->private->dev_id.ssid,
2020                               cdev->private->dev_id.devno, ret);
2021                 spin_lock_irq(sch->lock);
2022                 cdev->private->state = DEV_STATE_DISCONNECTED;
2023                 spin_unlock_irq(sch->lock);
2024                 /* notify driver after the resume cb */
2025                 goto out;
2026         }
2027         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
2028                    cdev->private->state == DEV_STATE_DISCONNECTED);
2029
2030 out:
2031         cdev->private->flags.resuming = 0;
2032 }
2033
2034 static int resume_handle_boxed(struct ccw_device *cdev)
2035 {
2036         cdev->private->state = DEV_STATE_BOXED;
2037         if (ccw_device_notify(cdev, CIO_BOXED))
2038                 return 0;
2039         ccw_device_schedule_sch_unregister(cdev);
2040         return -ENODEV;
2041 }
2042
2043 static int resume_handle_disc(struct ccw_device *cdev)
2044 {
2045         cdev->private->state = DEV_STATE_DISCONNECTED;
2046         if (ccw_device_notify(cdev, CIO_GONE))
2047                 return 0;
2048         ccw_device_schedule_sch_unregister(cdev);
2049         return -ENODEV;
2050 }
2051
2052 static int ccw_device_pm_restore(struct device *dev)
2053 {
2054         struct ccw_device *cdev = to_ccwdev(dev);
2055         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2056         int ret = 0, cm_enabled;
2057
2058         __ccw_device_pm_restore(cdev);
2059         spin_lock_irq(sch->lock);
2060         if (cio_is_console(sch->schid)) {
2061                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
2062                 spin_unlock_irq(sch->lock);
2063                 goto out_restore;
2064         }
2065         cdev->private->flags.donotify = 0;
2066         /* check recognition results */
2067         switch (cdev->private->state) {
2068         case DEV_STATE_OFFLINE:
2069                 break;
2070         case DEV_STATE_BOXED:
2071                 ret = resume_handle_boxed(cdev);
2072                 spin_unlock_irq(sch->lock);
2073                 if (ret)
2074                         goto out;
2075                 goto out_restore;
2076         case DEV_STATE_DISCONNECTED:
2077                 goto out_disc_unlock;
2078         default:
2079                 goto out_unreg_unlock;
2080         }
2081         /* check if the device id has changed */
2082         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
2083                 CIO_MSG_EVENT(0, "resume: sch 0.%x.%04x: failed (devno "
2084                               "changed from %04x to %04x)\n",
2085                               sch->schid.ssid, sch->schid.sch_no,
2086                               cdev->private->dev_id.devno,
2087                               sch->schib.pmcw.dev);
2088                 goto out_unreg_unlock;
2089         }
2090         /* check if the device type has changed */
2091         if (!ccw_device_test_sense_data(cdev)) {
2092                 ccw_device_update_sense_data(cdev);
2093                 PREPARE_WORK(&cdev->private->kick_work,
2094                              ccw_device_do_unbind_bind);
2095                 queue_work(ccw_device_work, &cdev->private->kick_work);
2096                 ret = -ENODEV;
2097                 goto out_unlock;
2098         }
2099         if (!cdev->online) {
2100                 ret = 0;
2101                 goto out_unlock;
2102         }
2103         ret = ccw_device_online(cdev);
2104         if (ret)
2105                 goto out_disc_unlock;
2106
2107         cm_enabled = cdev->private->cmb != NULL;
2108         spin_unlock_irq(sch->lock);
2109
2110         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
2111         if (cdev->private->state != DEV_STATE_ONLINE) {
2112                 spin_lock_irq(sch->lock);
2113                 goto out_disc_unlock;
2114         }
2115         if (cm_enabled) {
2116                 ret = ccw_set_cmf(cdev, 1);
2117                 if (ret) {
2118                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
2119                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
2120                                       cdev->private->dev_id.devno, ret);
2121                         ret = 0;
2122                 }
2123         }
2124
2125 out_restore:
2126         if (cdev->online && cdev->drv && cdev->drv->restore)
2127                 ret = cdev->drv->restore(cdev);
2128 out:
2129         return ret;
2130
2131 out_disc_unlock:
2132         ret = resume_handle_disc(cdev);
2133         spin_unlock_irq(sch->lock);
2134         if (ret)
2135                 return ret;
2136         goto out_restore;
2137
2138 out_unreg_unlock:
2139         ccw_device_schedule_sch_unregister(cdev);
2140         ret = -ENODEV;
2141 out_unlock:
2142         spin_unlock_irq(sch->lock);
2143         return ret;
2144 }
2145
2146 static struct dev_pm_ops ccw_pm_ops = {
2147         .prepare = ccw_device_pm_prepare,
2148         .complete = ccw_device_pm_complete,
2149         .freeze = ccw_device_pm_freeze,
2150         .thaw = ccw_device_pm_thaw,
2151         .restore = ccw_device_pm_restore,
2152 };
2153
2154 struct bus_type ccw_bus_type = {
2155         .name   = "ccw",
2156         .match  = ccw_bus_match,
2157         .uevent = ccw_uevent,
2158         .probe  = ccw_device_probe,
2159         .remove = ccw_device_remove,
2160         .shutdown = ccw_device_shutdown,
2161         .pm = &ccw_pm_ops,
2162 };
2163
2164 /**
2165  * ccw_driver_register() - register a ccw driver
2166  * @cdriver: driver to be registered
2167  *
2168  * This function is mainly a wrapper around driver_register().
2169  * Returns:
2170  *   %0 on success and a negative error value on failure.
2171  */
2172 int ccw_driver_register(struct ccw_driver *cdriver)
2173 {
2174         struct device_driver *drv = &cdriver->driver;
2175
2176         drv->bus = &ccw_bus_type;
2177         drv->name = cdriver->name;
2178         drv->owner = cdriver->owner;
2179
2180         return driver_register(drv);
2181 }
2182
2183 /**
2184  * ccw_driver_unregister() - deregister a ccw driver
2185  * @cdriver: driver to be deregistered
2186  *
2187  * This function is mainly a wrapper around driver_unregister().
2188  */
2189 void ccw_driver_unregister(struct ccw_driver *cdriver)
2190 {
2191         driver_unregister(&cdriver->driver);
2192 }
2193
2194 /* Helper func for qdio. */
2195 struct subchannel_id
2196 ccw_device_get_subchannel_id(struct ccw_device *cdev)
2197 {
2198         struct subchannel *sch;
2199
2200         sch = to_subchannel(cdev->dev.parent);
2201         return sch->schid;
2202 }
2203
2204 MODULE_LICENSE("GPL");
2205 EXPORT_SYMBOL(ccw_device_set_online);
2206 EXPORT_SYMBOL(ccw_device_set_offline);
2207 EXPORT_SYMBOL(ccw_driver_register);
2208 EXPORT_SYMBOL(ccw_driver_unregister);
2209 EXPORT_SYMBOL(get_ccwdev_by_busid);
2210 EXPORT_SYMBOL(ccw_bus_type);
2211 EXPORT_SYMBOL(ccw_device_work);
2212 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);