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   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   6  *                       IBM Corporation
   7  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/errno.h>
  15 #include <linux/err.h>
  16 #include <linux/slab.h>
  17 #include <linux/list.h>
  18 #include <linux/device.h>
  19 #include <linux/workqueue.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24 #include <asm/cmb.h>
  25
  26 #include "cio.h"
  27 #include "cio_debug.h"
  28 #include "css.h"
  29 #include "device.h"
  30 #include "ioasm.h"
  31
  32 /******************* bus type handling ***********************/
  33
  34 /* The Linux driver model distinguishes between a bus type and
  35  * the bus itself. Of course we only have one channel
  36  * subsystem driver and one channel system per machine, but
  37  * we still use the abstraction. T.R. says it's a good idea. */
  38 static int
  39 ccw_bus_match (struct device * dev, struct device_driver * drv)
  40 {
  41         struct ccw_device *cdev = to_ccwdev(dev);
  42         struct ccw_driver *cdrv = to_ccwdrv(drv);
  43         const struct ccw_device_id *ids = cdrv->ids, *found;
  44
  45         if (!ids)
  46                 return 0;
  47
  48         found = ccw_device_id_match(ids, &cdev->id);
  49         if (!found)
  50                 return 0;
  51
  52         cdev->id.driver_info = found->driver_info;
  53
  54         return 1;
  55 }
  56
  57 /* Store modalias string delimited by prefix/suffix string into buffer with
  58  * specified size. Return length of resulting string (excluding trailing '\0')
  59  * even if string doesn't fit buffer (snprintf semantics). */
  60 static int snprint_alias(char *buf, size_t size,
  61                          struct ccw_device_id *id, const char *suffix)
  62 {
  63         int len;
  64
  65         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  66         if (len > size)
  67                 return len;
  68         buf += len;
  69         size -= len;
  70
  71         if (id->dev_type != 0)
  72                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  73                                 id->dev_model, suffix);
  74         else
  75                 len += snprintf(buf, size, "dtdm%s", suffix);
  76
  77         return len;
  78 }
  79
  80 /* Set up environment variables for ccw device uevent. Return 0 on success,
  81  * non-zero otherwise. */
  82 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  83 {
  84         struct ccw_device *cdev = to_ccwdev(dev);
  85         struct ccw_device_id *id = &(cdev->id);
  86         int ret;
  87         char modalias_buf[30];
  88
  89         /* CU_TYPE= */
  90         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
  91         if (ret)
  92                 return ret;
  93
  94         /* CU_MODEL= */
  95         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
  96         if (ret)
  97                 return ret;
  98
  99         /* The next two can be zero, that's ok for us */
 100         /* DEV_TYPE= */
 101         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 102         if (ret)
 103                 return ret;
 104
 105         /* DEV_MODEL= */
 106         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 107         if (ret)
 108                 return ret;
 109
 110         /* MODALIAS=  */
 111         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 112         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 113         return ret;
 114 }
 115
 116 struct bus_type ccw_bus_type;
 117
 118 static int io_subchannel_probe (struct subchannel *);
 119 static int io_subchannel_remove (struct subchannel *);
 120 static int io_subchannel_notify(struct device *, int);
 121 static void io_subchannel_verify(struct device *);
 122 static void io_subchannel_ioterm(struct device *);
 123 static void io_subchannel_shutdown(struct subchannel *);
 124
 125 static struct css_driver io_subchannel_driver = {
 126         .subchannel_type = SUBCHANNEL_TYPE_IO,
 127         .drv = {
 128                 .name = "io_subchannel",
 129                 .bus  = &css_bus_type,
 130         },
 131         .irq = io_subchannel_irq,
 132         .notify = io_subchannel_notify,
 133         .verify = io_subchannel_verify,
 134         .termination = io_subchannel_ioterm,
 135         .probe = io_subchannel_probe,
 136         .remove = io_subchannel_remove,
 137         .shutdown = io_subchannel_shutdown,
 138 };
 139
 140 struct workqueue_struct *ccw_device_work;
 141 struct workqueue_struct *ccw_device_notify_work;
 142 wait_queue_head_t ccw_device_init_wq;
 143 atomic_t ccw_device_init_count;
 144
 145 static int __init
 146 init_ccw_bus_type (void)
 147 {
 148         int ret;
 149
 150         init_waitqueue_head(&ccw_device_init_wq);
 151         atomic_set(&ccw_device_init_count, 0);
 152
 153         ccw_device_work = create_singlethread_workqueue("cio");
 154         if (!ccw_device_work)
 155                 return -ENOMEM; /* FIXME: better errno ? */
 156         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 157         if (!ccw_device_notify_work) {
 158                 ret = -ENOMEM; /* FIXME: better errno ? */
 159                 goto out_err;
 160         }
 161         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 162         if (!slow_path_wq) {
 163                 ret = -ENOMEM; /* FIXME: better errno ? */
 164                 goto out_err;
 165         }
 166         if ((ret = bus_register (&ccw_bus_type)))
 167                 goto out_err;
 168
 169         if ((ret = driver_register(&io_subchannel_driver.drv)))
 170                 goto out_err;
 171
 172         wait_event(ccw_device_init_wq,
 173                    atomic_read(&ccw_device_init_count) == 0);
 174         flush_workqueue(ccw_device_work);
 175         return 0;
 176 out_err:
 177         if (ccw_device_work)
 178                 destroy_workqueue(ccw_device_work);
 179         if (ccw_device_notify_work)
 180                 destroy_workqueue(ccw_device_notify_work);
 181         if (slow_path_wq)
 182                 destroy_workqueue(slow_path_wq);
 183         return ret;
 184 }
 185
 186 static void __exit
 187 cleanup_ccw_bus_type (void)
 188 {
 189         driver_unregister(&io_subchannel_driver.drv);
 190         bus_unregister(&ccw_bus_type);
 191         destroy_workqueue(ccw_device_notify_work);
 192         destroy_workqueue(ccw_device_work);
 193 }
 194
 195 subsys_initcall(init_ccw_bus_type);
 196 module_exit(cleanup_ccw_bus_type);
 197
 198 /************************ device handling **************************/
 199
 200 /*
 201  * A ccw_device has some interfaces in sysfs in addition to the
 202  * standard ones.
 203  * The following entries are designed to export the information which
 204  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 205  * are obvious, so they don't have an entry :)
 206  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 207  */
 208 static ssize_t
 209 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 210 {
 211         struct subchannel *sch = to_subchannel(dev);
 212         struct chsc_ssd_info *ssd = &sch->ssd_info;
 213         ssize_t ret = 0;
 214         int chp;
 215         int mask;
 216
 217         for (chp = 0; chp < 8; chp++) {
 218                 mask = 0x80 >> chp;
 219                 if (ssd->path_mask & mask)
 220                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 221                 else
 222                         ret += sprintf(buf + ret, "00 ");
 223         }
 224         ret += sprintf (buf+ret, "\n");
 225         return min((ssize_t)PAGE_SIZE, ret);
 226 }
 227
 228 static ssize_t
 229 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 230 {
 231         struct subchannel *sch = to_subchannel(dev);
 232         struct pmcw *pmcw = &sch->schib.pmcw;
 233
 234         return sprintf (buf, "%02x %02x %02x\n",
 235                         pmcw->pim, pmcw->pam, pmcw->pom);
 236 }
 237
 238 static ssize_t
 239 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 240 {
 241         struct ccw_device *cdev = to_ccwdev(dev);
 242         struct ccw_device_id *id = &(cdev->id);
 243
 244         if (id->dev_type != 0)
 245                 return sprintf(buf, "%04x/%02x\n",
 246                                 id->dev_type, id->dev_model);
 247         else
 248                 return sprintf(buf, "n/a\n");
 249 }
 250
 251 static ssize_t
 252 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 253 {
 254         struct ccw_device *cdev = to_ccwdev(dev);
 255         struct ccw_device_id *id = &(cdev->id);
 256
 257         return sprintf(buf, "%04x/%02x\n",
 258                        id->cu_type, id->cu_model);
 259 }
 260
 261 static ssize_t
 262 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 263 {
 264         struct ccw_device *cdev = to_ccwdev(dev);
 265         struct ccw_device_id *id = &(cdev->id);
 266         int len;
 267
 268         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 269
 270         return len > PAGE_SIZE ? PAGE_SIZE : len;
 271 }
 272
 273 static ssize_t
 274 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 275 {
 276         struct ccw_device *cdev = to_ccwdev(dev);
 277
 278         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 279 }
 280
 281 int ccw_device_is_orphan(struct ccw_device *cdev)
 282 {
 283         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 284 }
 285
 286 static void ccw_device_unregister(struct ccw_device *cdev)
 287 {
 288         if (test_and_clear_bit(1, &cdev->private->registered))
 289                 device_del(&cdev->dev);
 290 }
 291
 292 static void ccw_device_remove_orphan_cb(struct device *dev)
 293 {
 294         struct ccw_device *cdev = to_ccwdev(dev);
 295
 296         ccw_device_unregister(cdev);
 297         put_device(&cdev->dev);
 298 }
 299
 300 static void ccw_device_remove_sch_cb(struct device *dev)
 301 {
 302         struct subchannel *sch;
 303
 304         sch = to_subchannel(dev);
 305         css_sch_device_unregister(sch);
 306         /* Reset intparm to zeroes. */
 307         sch->schib.pmcw.intparm = 0;
 308         cio_modify(sch);
 309         put_device(&sch->dev);
 310 }
 311
 312 static void
 313 ccw_device_remove_disconnected(struct ccw_device *cdev)
 314 {
 315         unsigned long flags;
 316         int rc;
 317
 318         /*
 319          * Forced offline in disconnected state means
 320          * 'throw away device'.
 321          */
 322         if (ccw_device_is_orphan(cdev)) {
 323                 /*
 324                  * Deregister ccw device.
 325                  * Unfortunately, we cannot do this directly from the
 326                  * attribute method.
 327                  */
 328                 spin_lock_irqsave(cdev->ccwlock, flags);
 329                 cdev->private->state = DEV_STATE_NOT_OPER;
 330                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 331                 rc = device_schedule_callback(&cdev->dev,
 332                                               ccw_device_remove_orphan_cb);
 333                 if (rc)
 334                         CIO_MSG_EVENT(2, "Couldn't unregister orphan "
 335                                       "0.%x.%04x\n",
 336                                       cdev->private->dev_id.ssid,
 337                                       cdev->private->dev_id.devno);
 338                 return;
 339         }
 340         /* Deregister subchannel, which will kill the ccw device. */
 341         rc = device_schedule_callback(cdev->dev.parent,
 342                                       ccw_device_remove_sch_cb);
 343         if (rc)
 344                 CIO_MSG_EVENT(2, "Couldn't unregister disconnected device "
 345                               "0.%x.%04x\n",
 346                               cdev->private->dev_id.ssid,
 347                               cdev->private->dev_id.devno);
 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         ret = ccw_device_offline(cdev);
 378         if (ret == -ENODEV) {
 379                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 380                         cdev->private->state = DEV_STATE_OFFLINE;
 381                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 382                 }
 383                 spin_unlock_irq(cdev->ccwlock);
 384                 return ret;
 385         }
 386         spin_unlock_irq(cdev->ccwlock);
 387         if (ret == 0)
 388                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 389         else {
 390                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
 391                               "device 0.%x.%04x\n",
 392                               ret, cdev->private->dev_id.ssid,
 393                               cdev->private->dev_id.devno);
 394                 cdev->online = 1;
 395         }
 396         return ret;
 397 }
 398
 399 /**
 400  * ccw_device_set_online() - enable a ccw device for I/O
 401  * @cdev: target ccw device
 402  *
 403  * This function first enables @cdev and then calls the driver's set_online()
 404  * function for @cdev, if given. If set_online() returns an error, @cdev is
 405  * disabled again.
 406  * Returns:
 407  *   %0 on success and a negative error value on failure.
 408  * Context:
 409  *  enabled, ccw device lock not held
 410  */
 411 int ccw_device_set_online(struct ccw_device *cdev)
 412 {
 413         int ret;
 414
 415         if (!cdev)
 416                 return -ENODEV;
 417         if (cdev->online || !cdev->drv)
 418                 return -EINVAL;
 419
 420         spin_lock_irq(cdev->ccwlock);
 421         ret = ccw_device_online(cdev);
 422         spin_unlock_irq(cdev->ccwlock);
 423         if (ret == 0)
 424                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 425         else {
 426                 CIO_MSG_EVENT(2, "ccw_device_online returned %d, "
 427                               "device 0.%x.%04x\n",
 428                               ret, cdev->private->dev_id.ssid,
 429                               cdev->private->dev_id.devno);
 430                 return ret;
 431         }
 432         if (cdev->private->state != DEV_STATE_ONLINE)
 433                 return -ENODEV;
 434         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 435                 cdev->online = 1;
 436                 return 0;
 437         }
 438         spin_lock_irq(cdev->ccwlock);
 439         ret = ccw_device_offline(cdev);
 440         spin_unlock_irq(cdev->ccwlock);
 441         if (ret == 0)
 442                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 443         else
 444                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
 445                               "device 0.%x.%04x\n",
 446                               ret, cdev->private->dev_id.ssid,
 447                               cdev->private->dev_id.devno);
 448         return (ret == 0) ? -ENODEV : ret;
 449 }
 450
 451 static void online_store_handle_offline(struct ccw_device *cdev)
 452 {
 453         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 454                 ccw_device_remove_disconnected(cdev);
 455         else if (cdev->drv && cdev->drv->set_offline)
 456                 ccw_device_set_offline(cdev);
 457 }
 458
 459 static int online_store_recog_and_online(struct ccw_device *cdev)
 460 {
 461         int ret;
 462
 463         /* Do device recognition, if needed. */
 464         if (cdev->id.cu_type == 0) {
 465                 ret = ccw_device_recognition(cdev);
 466                 if (ret) {
 467                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 468                                       "for device 0.%x.%04x (ret=%d)\n",
 469                                       cdev->private->dev_id.ssid,
 470                                       cdev->private->dev_id.devno, ret);
 471                         return ret;
 472                 }
 473                 wait_event(cdev->private->wait_q,
 474                            cdev->private->flags.recog_done);
 475         }
 476         if (cdev->drv && cdev->drv->set_online)
 477                 ccw_device_set_online(cdev);
 478         return 0;
 479 }
 480 static void online_store_handle_online(struct ccw_device *cdev, int force)
 481 {
 482         int ret;
 483
 484         ret = online_store_recog_and_online(cdev);
 485         if (ret)
 486                 return;
 487         if (force && cdev->private->state == DEV_STATE_BOXED) {
 488                 ret = ccw_device_stlck(cdev);
 489                 if (ret) {
 490                         dev_warn(&cdev->dev,
 491                                  "ccw_device_stlck returned %d!\n", ret);
 492                         return;
 493                 }
 494                 if (cdev->id.cu_type == 0)
 495                         cdev->private->state = DEV_STATE_NOT_OPER;
 496                 online_store_recog_and_online(cdev);
 497         }
 498
 499 }
 500
 501 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 502                              const char *buf, size_t count)
 503 {
 504         struct ccw_device *cdev = to_ccwdev(dev);
 505         int i, force;
 506         char *tmp;
 507
 508         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 509                 return -EAGAIN;
 510
 511         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 512                 atomic_set(&cdev->private->onoff, 0);
 513                 return -EINVAL;
 514         }
 515         if (!strncmp(buf, "force\n", count)) {
 516                 force = 1;
 517                 i = 1;
 518         } else {
 519                 force = 0;
 520                 i = simple_strtoul(buf, &tmp, 16);
 521         }
 522
 523         switch (i) {
 524         case 0:
 525                 online_store_handle_offline(cdev);
 526                 break;
 527         case 1:
 528                 online_store_handle_online(cdev, force);
 529                 break;
 530         default:
 531                 count = -EINVAL;
 532         }
 533         if (cdev->drv)
 534                 module_put(cdev->drv->owner);
 535         atomic_set(&cdev->private->onoff, 0);
 536         return count;
 537 }
 538
 539 static ssize_t
 540 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 541 {
 542         struct ccw_device *cdev = to_ccwdev(dev);
 543         struct subchannel *sch;
 544
 545         if (ccw_device_is_orphan(cdev))
 546                 return sprintf(buf, "no device\n");
 547         switch (cdev->private->state) {
 548         case DEV_STATE_BOXED:
 549                 return sprintf(buf, "boxed\n");
 550         case DEV_STATE_DISCONNECTED:
 551         case DEV_STATE_DISCONNECTED_SENSE_ID:
 552         case DEV_STATE_NOT_OPER:
 553                 sch = to_subchannel(dev->parent);
 554                 if (!sch->lpm)
 555                         return sprintf(buf, "no path\n");
 556                 else
 557                         return sprintf(buf, "no device\n");
 558         default:
 559                 /* All other states considered fine. */
 560                 return sprintf(buf, "good\n");
 561         }
 562 }
 563
 564 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 565 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 566 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 567 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 568 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 569 static DEVICE_ATTR(online, 0644, online_show, online_store);
 570 extern struct device_attribute dev_attr_cmb_enable;
 571 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 572
 573 static struct attribute * subch_attrs[] = {
 574         &dev_attr_chpids.attr,
 575         &dev_attr_pimpampom.attr,
 576         NULL,
 577 };
 578
 579 static struct attribute_group subch_attr_group = {
 580         .attrs = subch_attrs,
 581 };
 582
 583 struct attribute_group *subch_attr_groups[] = {
 584         &subch_attr_group,
 585         NULL,
 586 };
 587
 588 static struct attribute * ccwdev_attrs[] = {
 589         &dev_attr_devtype.attr,
 590         &dev_attr_cutype.attr,
 591         &dev_attr_modalias.attr,
 592         &dev_attr_online.attr,
 593         &dev_attr_cmb_enable.attr,
 594         &dev_attr_availability.attr,
 595         NULL,
 596 };
 597
 598 static struct attribute_group ccwdev_attr_group = {
 599         .attrs = ccwdev_attrs,
 600 };
 601
 602 static struct attribute_group *ccwdev_attr_groups[] = {
 603         &ccwdev_attr_group,
 604         NULL,
 605 };
 606
 607 /* this is a simple abstraction for device_register that sets the
 608  * correct bus type and adds the bus specific files */
 609 static int ccw_device_register(struct ccw_device *cdev)
 610 {
 611         struct device *dev = &cdev->dev;
 612         int ret;
 613
 614         dev->bus = &ccw_bus_type;
 615
 616         if ((ret = device_add(dev)))
 617                 return ret;
 618
 619         set_bit(1, &cdev->private->registered);
 620         return ret;
 621 }
 622
 623 struct match_data {
 624         struct ccw_dev_id dev_id;
 625         struct ccw_device * sibling;
 626 };
 627
 628 static int
 629 match_devno(struct device * dev, void * data)
 630 {
 631         struct match_data * d = data;
 632         struct ccw_device * cdev;
 633
 634         cdev = to_ccwdev(dev);
 635         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 636             !ccw_device_is_orphan(cdev) &&
 637             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 638             (cdev != d->sibling))
 639                 return 1;
 640         return 0;
 641 }
 642
 643 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 644                                                      struct ccw_device *sibling)
 645 {
 646         struct device *dev;
 647         struct match_data data;
 648
 649         data.dev_id = *dev_id;
 650         data.sibling = sibling;
 651         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 652
 653         return dev ? to_ccwdev(dev) : NULL;
 654 }
 655
 656 static int match_orphan(struct device *dev, void *data)
 657 {
 658         struct ccw_dev_id *dev_id;
 659         struct ccw_device *cdev;
 660
 661         dev_id = data;
 662         cdev = to_ccwdev(dev);
 663         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 664 }
 665
 666 static struct ccw_device *
 667 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 668                               struct ccw_dev_id *dev_id)
 669 {
 670         struct device *dev;
 671
 672         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 673                                 match_orphan);
 674
 675         return dev ? to_ccwdev(dev) : NULL;
 676 }
 677
 678 static void
 679 ccw_device_add_changed(struct work_struct *work)
 680 {
 681         struct ccw_device_private *priv;
 682         struct ccw_device *cdev;
 683
 684         priv = container_of(work, struct ccw_device_private, kick_work);
 685         cdev = priv->cdev;
 686         if (device_add(&cdev->dev)) {
 687                 put_device(&cdev->dev);
 688                 return;
 689         }
 690         set_bit(1, &cdev->private->registered);
 691 }
 692
 693 void ccw_device_do_unreg_rereg(struct work_struct *work)
 694 {
 695         struct ccw_device_private *priv;
 696         struct ccw_device *cdev;
 697         struct subchannel *sch;
 698
 699         priv = container_of(work, struct ccw_device_private, kick_work);
 700         cdev = priv->cdev;
 701         sch = to_subchannel(cdev->dev.parent);
 702
 703         ccw_device_unregister(cdev);
 704         PREPARE_WORK(&cdev->private->kick_work,
 705                      ccw_device_add_changed);
 706         queue_work(ccw_device_work, &cdev->private->kick_work);
 707 }
 708
 709 static void
 710 ccw_device_release(struct device *dev)
 711 {
 712         struct ccw_device *cdev;
 713
 714         cdev = to_ccwdev(dev);
 715         kfree(cdev->private);
 716         kfree(cdev);
 717 }
 718
 719 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 720 {
 721         struct ccw_device *cdev;
 722
 723         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 724         if (cdev) {
 725                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 726                                         GFP_KERNEL | GFP_DMA);
 727                 if (cdev->private)
 728                         return cdev;
 729         }
 730         kfree(cdev);
 731         return ERR_PTR(-ENOMEM);
 732 }
 733
 734 static int io_subchannel_initialize_dev(struct subchannel *sch,
 735                                         struct ccw_device *cdev)
 736 {
 737         cdev->private->cdev = cdev;
 738         atomic_set(&cdev->private->onoff, 0);
 739         cdev->dev.parent = &sch->dev;
 740         cdev->dev.release = ccw_device_release;
 741         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 742         cdev->dev.groups = ccwdev_attr_groups;
 743         /* Do first half of device_register. */
 744         device_initialize(&cdev->dev);
 745         if (!get_device(&sch->dev)) {
 746                 if (cdev->dev.release)
 747                         cdev->dev.release(&cdev->dev);
 748                 return -ENODEV;
 749         }
 750         return 0;
 751 }
 752
 753 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 754 {
 755         struct ccw_device *cdev;
 756         int ret;
 757
 758         cdev = io_subchannel_allocate_dev(sch);
 759         if (!IS_ERR(cdev)) {
 760                 ret = io_subchannel_initialize_dev(sch, cdev);
 761                 if (ret) {
 762                         kfree(cdev);
 763                         cdev = ERR_PTR(ret);
 764                 }
 765         }
 766         return cdev;
 767 }
 768
 769 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 770
 771 static void sch_attach_device(struct subchannel *sch,
 772                               struct ccw_device *cdev)
 773 {
 774         css_update_ssd_info(sch);
 775         spin_lock_irq(sch->lock);
 776         sch->dev.driver_data = cdev;
 777         cdev->private->schid = sch->schid;
 778         cdev->ccwlock = sch->lock;
 779         device_trigger_reprobe(sch);
 780         spin_unlock_irq(sch->lock);
 781 }
 782
 783 static void sch_attach_disconnected_device(struct subchannel *sch,
 784                                            struct ccw_device *cdev)
 785 {
 786         struct subchannel *other_sch;
 787         int ret;
 788
 789         other_sch = to_subchannel(get_device(cdev->dev.parent));
 790         ret = device_move(&cdev->dev, &sch->dev);
 791         if (ret) {
 792                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
 793                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 794                               cdev->private->dev_id.devno, ret);
 795                 put_device(&other_sch->dev);
 796                 return;
 797         }
 798         other_sch->dev.driver_data = NULL;
 799         /* No need to keep a subchannel without ccw device around. */
 800         css_sch_device_unregister(other_sch);
 801         put_device(&other_sch->dev);
 802         sch_attach_device(sch, cdev);
 803 }
 804
 805 static void sch_attach_orphaned_device(struct subchannel *sch,
 806                                        struct ccw_device *cdev)
 807 {
 808         int ret;
 809
 810         /* Try to move the ccw device to its new subchannel. */
 811         ret = device_move(&cdev->dev, &sch->dev);
 812         if (ret) {
 813                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 814                               "failed (ret=%d)!\n",
 815                               cdev->private->dev_id.ssid,
 816                               cdev->private->dev_id.devno, ret);
 817                 return;
 818         }
 819         sch_attach_device(sch, cdev);
 820 }
 821
 822 static void sch_create_and_recog_new_device(struct subchannel *sch)
 823 {
 824         struct ccw_device *cdev;
 825
 826         /* Need to allocate a new ccw device. */
 827         cdev = io_subchannel_create_ccwdev(sch);
 828         if (IS_ERR(cdev)) {
 829                 /* OK, we did everything we could... */
 830                 css_sch_device_unregister(sch);
 831                 return;
 832         }
 833         spin_lock_irq(sch->lock);
 834         sch->dev.driver_data = cdev;
 835         spin_unlock_irq(sch->lock);
 836         /* Start recognition for the new ccw device. */
 837         if (io_subchannel_recog(cdev, sch)) {
 838                 spin_lock_irq(sch->lock);
 839                 sch->dev.driver_data = NULL;
 840                 spin_unlock_irq(sch->lock);
 841                 if (cdev->dev.release)
 842                         cdev->dev.release(&cdev->dev);
 843                 css_sch_device_unregister(sch);
 844         }
 845 }
 846
 847
 848 void ccw_device_move_to_orphanage(struct work_struct *work)
 849 {
 850         struct ccw_device_private *priv;
 851         struct ccw_device *cdev;
 852         struct ccw_device *replacing_cdev;
 853         struct subchannel *sch;
 854         int ret;
 855         struct channel_subsystem *css;
 856         struct ccw_dev_id dev_id;
 857
 858         priv = container_of(work, struct ccw_device_private, kick_work);
 859         cdev = priv->cdev;
 860         sch = to_subchannel(cdev->dev.parent);
 861         css = to_css(sch->dev.parent);
 862         dev_id.devno = sch->schib.pmcw.dev;
 863         dev_id.ssid = sch->schid.ssid;
 864
 865         /*
 866          * Move the orphaned ccw device to the orphanage so the replacing
 867          * ccw device can take its place on the subchannel.
 868          */
 869         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 870         if (ret) {
 871                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 872                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 873                               cdev->private->dev_id.devno, ret);
 874                 return;
 875         }
 876         cdev->ccwlock = css->pseudo_subchannel->lock;
 877         /*
 878          * Search for the replacing ccw device
 879          * - among the disconnected devices
 880          * - in the orphanage
 881          */
 882         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 883         if (replacing_cdev) {
 884                 sch_attach_disconnected_device(sch, replacing_cdev);
 885                 return;
 886         }
 887         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 888         if (replacing_cdev) {
 889                 sch_attach_orphaned_device(sch, replacing_cdev);
 890                 return;
 891         }
 892         sch_create_and_recog_new_device(sch);
 893 }
 894
 895 /*
 896  * Register recognized device.
 897  */
 898 static void
 899 io_subchannel_register(struct work_struct *work)
 900 {
 901         struct ccw_device_private *priv;
 902         struct ccw_device *cdev;
 903         struct subchannel *sch;
 904         int ret;
 905         unsigned long flags;
 906
 907         priv = container_of(work, struct ccw_device_private, kick_work);
 908         cdev = priv->cdev;
 909         sch = to_subchannel(cdev->dev.parent);
 910         css_update_ssd_info(sch);
 911         /*
 912          * io_subchannel_register() will also be called after device
 913          * recognition has been done for a boxed device (which will already
 914          * be registered). We need to reprobe since we may now have sense id
 915          * information.
 916          */
 917         if (klist_node_attached(&cdev->dev.knode_parent)) {
 918                 if (!cdev->drv) {
 919                         ret = device_reprobe(&cdev->dev);
 920                         if (ret)
 921                                 /* We can't do much here. */
 922                                 CIO_MSG_EVENT(2, "device_reprobe() returned"
 923                                               " %d for 0.%x.%04x\n", ret,
 924                                               cdev->private->dev_id.ssid,
 925                                               cdev->private->dev_id.devno);
 926                 }
 927                 goto out;
 928         }
 929         /*
 930          * Now we know this subchannel will stay, we can throw
 931          * our delayed uevent.
 932          */
 933         sch->dev.uevent_suppress = 0;
 934         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 935         /* make it known to the system */
 936         ret = ccw_device_register(cdev);
 937         if (ret) {
 938                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 939                               cdev->private->dev_id.ssid,
 940                               cdev->private->dev_id.devno, ret);
 941                 put_device(&cdev->dev);
 942                 spin_lock_irqsave(sch->lock, flags);
 943                 sch->dev.driver_data = NULL;
 944                 spin_unlock_irqrestore(sch->lock, flags);
 945                 kfree (cdev->private);
 946                 kfree (cdev);
 947                 put_device(&sch->dev);
 948                 if (atomic_dec_and_test(&ccw_device_init_count))
 949                         wake_up(&ccw_device_init_wq);
 950                 return;
 951         }
 952         put_device(&cdev->dev);
 953 out:
 954         cdev->private->flags.recog_done = 1;
 955         put_device(&sch->dev);
 956         wake_up(&cdev->private->wait_q);
 957         if (atomic_dec_and_test(&ccw_device_init_count))
 958                 wake_up(&ccw_device_init_wq);
 959 }
 960
 961 static void ccw_device_call_sch_unregister(struct work_struct *work)
 962 {
 963         struct ccw_device_private *priv;
 964         struct ccw_device *cdev;
 965         struct subchannel *sch;
 966
 967         priv = container_of(work, struct ccw_device_private, kick_work);
 968         cdev = priv->cdev;
 969         sch = to_subchannel(cdev->dev.parent);
 970         css_sch_device_unregister(sch);
 971         /* Reset intparm to zeroes. */
 972         sch->schib.pmcw.intparm = 0;
 973         cio_modify(sch);
 974         put_device(&cdev->dev);
 975         put_device(&sch->dev);
 976 }
 977
 978 /*
 979  * subchannel recognition done. Called from the state machine.
 980  */
 981 void
 982 io_subchannel_recog_done(struct ccw_device *cdev)
 983 {
 984         struct subchannel *sch;
 985
 986         if (css_init_done == 0) {
 987                 cdev->private->flags.recog_done = 1;
 988                 return;
 989         }
 990         switch (cdev->private->state) {
 991         case DEV_STATE_NOT_OPER:
 992                 cdev->private->flags.recog_done = 1;
 993                 /* Remove device found not operational. */
 994                 if (!get_device(&cdev->dev))
 995                         break;
 996                 sch = to_subchannel(cdev->dev.parent);
 997                 PREPARE_WORK(&cdev->private->kick_work,
 998                              ccw_device_call_sch_unregister);
 999                 queue_work(slow_path_wq, &cdev->private->kick_work);
1000                 if (atomic_dec_and_test(&ccw_device_init_count))
1001                         wake_up(&ccw_device_init_wq);
1002                 break;
1003         case DEV_STATE_BOXED:
1004                 /* Device did not respond in time. */
1005         case DEV_STATE_OFFLINE:
1006                 /*
1007                  * We can't register the device in interrupt context so
1008                  * we schedule a work item.
1009                  */
1010                 if (!get_device(&cdev->dev))
1011                         break;
1012                 PREPARE_WORK(&cdev->private->kick_work,
1013                              io_subchannel_register);
1014                 queue_work(slow_path_wq, &cdev->private->kick_work);
1015                 break;
1016         }
1017 }
1018
1019 static int
1020 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1021 {
1022         int rc;
1023         struct ccw_device_private *priv;
1024
1025         sch->dev.driver_data = cdev;
1026         sch->driver = &io_subchannel_driver;
1027         cdev->ccwlock = sch->lock;
1028
1029         /* Init private data. */
1030         priv = cdev->private;
1031         priv->dev_id.devno = sch->schib.pmcw.dev;
1032         priv->dev_id.ssid = sch->schid.ssid;
1033         priv->schid = sch->schid;
1034         priv->state = DEV_STATE_NOT_OPER;
1035         INIT_LIST_HEAD(&priv->cmb_list);
1036         init_waitqueue_head(&priv->wait_q);
1037         init_timer(&priv->timer);
1038
1039         /* Set an initial name for the device. */
1040         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1041                   sch->schid.ssid, sch->schib.pmcw.dev);
1042
1043         /* Increase counter of devices currently in recognition. */
1044         atomic_inc(&ccw_device_init_count);
1045
1046         /* Start async. device sensing. */
1047         spin_lock_irq(sch->lock);
1048         rc = ccw_device_recognition(cdev);
1049         spin_unlock_irq(sch->lock);
1050         if (rc) {
1051                 if (atomic_dec_and_test(&ccw_device_init_count))
1052                         wake_up(&ccw_device_init_wq);
1053         }
1054         return rc;
1055 }
1056
1057 static void ccw_device_move_to_sch(struct work_struct *work)
1058 {
1059         struct ccw_device_private *priv;
1060         int rc;
1061         struct subchannel *sch;
1062         struct ccw_device *cdev;
1063         struct subchannel *former_parent;
1064
1065         priv = container_of(work, struct ccw_device_private, kick_work);
1066         sch = priv->sch;
1067         cdev = priv->cdev;
1068         former_parent = ccw_device_is_orphan(cdev) ?
1069                 NULL : to_subchannel(get_device(cdev->dev.parent));
1070         mutex_lock(&sch->reg_mutex);
1071         /* Try to move the ccw device to its new subchannel. */
1072         rc = device_move(&cdev->dev, &sch->dev);
1073         mutex_unlock(&sch->reg_mutex);
1074         if (rc) {
1075                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1076                               "0.%x.%04x failed (ret=%d)!\n",
1077                               cdev->private->dev_id.ssid,
1078                               cdev->private->dev_id.devno, sch->schid.ssid,
1079                               sch->schid.sch_no, rc);
1080                 css_sch_device_unregister(sch);
1081                 goto out;
1082         }
1083         if (former_parent) {
1084                 spin_lock_irq(former_parent->lock);
1085                 former_parent->dev.driver_data = NULL;
1086                 spin_unlock_irq(former_parent->lock);
1087                 css_sch_device_unregister(former_parent);
1088                 /* Reset intparm to zeroes. */
1089                 former_parent->schib.pmcw.intparm = 0;
1090                 cio_modify(former_parent);
1091         }
1092         sch_attach_device(sch, cdev);
1093 out:
1094         if (former_parent)
1095                 put_device(&former_parent->dev);
1096         put_device(&cdev->dev);
1097 }
1098
1099 static int
1100 io_subchannel_probe (struct subchannel *sch)
1101 {
1102         struct ccw_device *cdev;
1103         int rc;
1104         unsigned long flags;
1105         struct ccw_dev_id dev_id;
1106
1107         if (sch->dev.driver_data) {
1108                 /*
1109                  * This subchannel already has an associated ccw_device.
1110                  * Register it and exit. This happens for all early
1111                  * device, e.g. the console.
1112                  */
1113                 cdev = sch->dev.driver_data;
1114                 cdev->dev.groups = ccwdev_attr_groups;
1115                 device_initialize(&cdev->dev);
1116                 ccw_device_register(cdev);
1117                 /*
1118                  * Check if the device is already online. If it is
1119                  * the reference count needs to be corrected
1120                  * (see ccw_device_online and css_init_done for the
1121                  * ugly details).
1122                  */
1123                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1124                     cdev->private->state != DEV_STATE_OFFLINE &&
1125                     cdev->private->state != DEV_STATE_BOXED)
1126                         get_device(&cdev->dev);
1127                 return 0;
1128         }
1129         /*
1130          * First check if a fitting device may be found amongst the
1131          * disconnected devices or in the orphanage.
1132          */
1133         dev_id.devno = sch->schib.pmcw.dev;
1134         dev_id.ssid = sch->schid.ssid;
1135         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1136         if (!cdev)
1137                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1138                                                      &dev_id);
1139         if (cdev) {
1140                 /*
1141                  * Schedule moving the device until when we have a registered
1142                  * subchannel to move to and succeed the probe. We can
1143                  * unregister later again, when the probe is through.
1144                  */
1145                 cdev->private->sch = sch;
1146                 PREPARE_WORK(&cdev->private->kick_work,
1147                              ccw_device_move_to_sch);
1148                 queue_work(slow_path_wq, &cdev->private->kick_work);
1149                 return 0;
1150         }
1151         cdev = io_subchannel_create_ccwdev(sch);
1152         if (IS_ERR(cdev))
1153                 return PTR_ERR(cdev);
1154
1155         rc = io_subchannel_recog(cdev, sch);
1156         if (rc) {
1157                 spin_lock_irqsave(sch->lock, flags);
1158                 sch->dev.driver_data = NULL;
1159                 spin_unlock_irqrestore(sch->lock, flags);
1160                 if (cdev->dev.release)
1161                         cdev->dev.release(&cdev->dev);
1162         }
1163
1164         return rc;
1165 }
1166
1167 static int
1168 io_subchannel_remove (struct subchannel *sch)
1169 {
1170         struct ccw_device *cdev;
1171         unsigned long flags;
1172
1173         if (!sch->dev.driver_data)
1174                 return 0;
1175         cdev = sch->dev.driver_data;
1176         /* Set ccw device to not operational and drop reference. */
1177         spin_lock_irqsave(cdev->ccwlock, flags);
1178         sch->dev.driver_data = NULL;
1179         cdev->private->state = DEV_STATE_NOT_OPER;
1180         spin_unlock_irqrestore(cdev->ccwlock, flags);
1181         ccw_device_unregister(cdev);
1182         put_device(&cdev->dev);
1183         return 0;
1184 }
1185
1186 static int
1187 io_subchannel_notify(struct device *dev, int event)
1188 {
1189         struct ccw_device *cdev;
1190
1191         cdev = dev->driver_data;
1192         if (!cdev)
1193                 return 0;
1194         if (!cdev->drv)
1195                 return 0;
1196         if (!cdev->online)
1197                 return 0;
1198         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1199 }
1200
1201 static void
1202 io_subchannel_verify(struct device *dev)
1203 {
1204         struct ccw_device *cdev;
1205
1206         cdev = dev->driver_data;
1207         if (cdev)
1208                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1209 }
1210
1211 static void
1212 io_subchannel_ioterm(struct device *dev)
1213 {
1214         struct ccw_device *cdev;
1215
1216         cdev = dev->driver_data;
1217         if (!cdev)
1218                 return;
1219         /* Internal I/O will be retried by the interrupt handler. */
1220         if (cdev->private->flags.intretry)
1221                 return;
1222         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1223         if (cdev->handler)
1224                 cdev->handler(cdev, cdev->private->intparm,
1225                               ERR_PTR(-EIO));
1226 }
1227
1228 static void
1229 io_subchannel_shutdown(struct subchannel *sch)
1230 {
1231         struct ccw_device *cdev;
1232         int ret;
1233
1234         cdev = sch->dev.driver_data;
1235
1236         if (cio_is_console(sch->schid))
1237                 return;
1238         if (!sch->schib.pmcw.ena)
1239                 /* Nothing to do. */
1240                 return;
1241         ret = cio_disable_subchannel(sch);
1242         if (ret != -EBUSY)
1243                 /* Subchannel is disabled, we're done. */
1244                 return;
1245         cdev->private->state = DEV_STATE_QUIESCE;
1246         if (cdev->handler)
1247                 cdev->handler(cdev, cdev->private->intparm,
1248                               ERR_PTR(-EIO));
1249         ret = ccw_device_cancel_halt_clear(cdev);
1250         if (ret == -EBUSY) {
1251                 ccw_device_set_timeout(cdev, HZ/10);
1252                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1253         }
1254         cio_disable_subchannel(sch);
1255 }
1256
1257 #ifdef CONFIG_CCW_CONSOLE
1258 static struct ccw_device console_cdev;
1259 static struct ccw_device_private console_private;
1260 static int console_cdev_in_use;
1261
1262 static DEFINE_SPINLOCK(ccw_console_lock);
1263
1264 spinlock_t * cio_get_console_lock(void)
1265 {
1266         return &ccw_console_lock;
1267 }
1268
1269 static int
1270 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1271 {
1272         int rc;
1273
1274         /* Initialize the ccw_device structure. */
1275         cdev->dev.parent= &sch->dev;
1276         rc = io_subchannel_recog(cdev, sch);
1277         if (rc)
1278                 return rc;
1279
1280         /* Now wait for the async. recognition to come to an end. */
1281         spin_lock_irq(cdev->ccwlock);
1282         while (!dev_fsm_final_state(cdev))
1283                 wait_cons_dev();
1284         rc = -EIO;
1285         if (cdev->private->state != DEV_STATE_OFFLINE)
1286                 goto out_unlock;
1287         ccw_device_online(cdev);
1288         while (!dev_fsm_final_state(cdev))
1289                 wait_cons_dev();
1290         if (cdev->private->state != DEV_STATE_ONLINE)
1291                 goto out_unlock;
1292         rc = 0;
1293 out_unlock:
1294         spin_unlock_irq(cdev->ccwlock);
1295         return 0;
1296 }
1297
1298 struct ccw_device *
1299 ccw_device_probe_console(void)
1300 {
1301         struct subchannel *sch;
1302         int ret;
1303
1304         if (xchg(&console_cdev_in_use, 1) != 0)
1305                 return ERR_PTR(-EBUSY);
1306         sch = cio_probe_console();
1307         if (IS_ERR(sch)) {
1308                 console_cdev_in_use = 0;
1309                 return (void *) sch;
1310         }
1311         memset(&console_cdev, 0, sizeof(struct ccw_device));
1312         memset(&console_private, 0, sizeof(struct ccw_device_private));
1313         console_cdev.private = &console_private;
1314         console_private.cdev = &console_cdev;
1315         ret = ccw_device_console_enable(&console_cdev, sch);
1316         if (ret) {
1317                 cio_release_console();
1318                 console_cdev_in_use = 0;
1319                 return ERR_PTR(ret);
1320         }
1321         console_cdev.online = 1;
1322         return &console_cdev;
1323 }
1324 #endif
1325
1326 /*
1327  * get ccw_device matching the busid, but only if owned by cdrv
1328  */
1329 static int
1330 __ccwdev_check_busid(struct device *dev, void *id)
1331 {
1332         char *bus_id;
1333
1334         bus_id = id;
1335
1336         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1337 }
1338
1339
1340 /**
1341  * get_ccwdev_by_busid() - obtain device from a bus id
1342  * @cdrv: driver the device is owned by
1343  * @bus_id: bus id of the device to be searched
1344  *
1345  * This function searches all devices owned by @cdrv for a device with a bus
1346  * id matching @bus_id.
1347  * Returns:
1348  *  If a match is found, its reference count of the found device is increased
1349  *  and it is returned; else %NULL is returned.
1350  */
1351 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1352                                        const char *bus_id)
1353 {
1354         struct device *dev;
1355         struct device_driver *drv;
1356
1357         drv = get_driver(&cdrv->driver);
1358         if (!drv)
1359                 return NULL;
1360
1361         dev = driver_find_device(drv, NULL, (void *)bus_id,
1362                                  __ccwdev_check_busid);
1363         put_driver(drv);
1364
1365         return dev ? to_ccwdev(dev) : NULL;
1366 }
1367
1368 /************************** device driver handling ************************/
1369
1370 /* This is the implementation of the ccw_driver class. The probe, remove
1371  * and release methods are initially very similar to the device_driver
1372  * implementations, with the difference that they have ccw_device
1373  * arguments.
1374  *
1375  * A ccw driver also contains the information that is needed for
1376  * device matching.
1377  */
1378 static int
1379 ccw_device_probe (struct device *dev)
1380 {
1381         struct ccw_device *cdev = to_ccwdev(dev);
1382         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1383         int ret;
1384
1385         cdev->drv = cdrv; /* to let the driver call _set_online */
1386
1387         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1388
1389         if (ret) {
1390                 cdev->drv = NULL;
1391                 return ret;
1392         }
1393
1394         return 0;
1395 }
1396
1397 static int
1398 ccw_device_remove (struct device *dev)
1399 {
1400         struct ccw_device *cdev = to_ccwdev(dev);
1401         struct ccw_driver *cdrv = cdev->drv;
1402         int ret;
1403
1404         if (cdrv->remove)
1405                 cdrv->remove(cdev);
1406         if (cdev->online) {
1407                 cdev->online = 0;
1408                 spin_lock_irq(cdev->ccwlock);
1409                 ret = ccw_device_offline(cdev);
1410                 spin_unlock_irq(cdev->ccwlock);
1411                 if (ret == 0)
1412                         wait_event(cdev->private->wait_q,
1413                                    dev_fsm_final_state(cdev));
1414                 else
1415                         //FIXME: we can't fail!
1416                         CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
1417                                       "device 0.%x.%04x\n",
1418                                       ret, cdev->private->dev_id.ssid,
1419                                       cdev->private->dev_id.devno);
1420         }
1421         ccw_device_set_timeout(cdev, 0);
1422         cdev->drv = NULL;
1423         return 0;
1424 }
1425
1426 static void ccw_device_shutdown(struct device *dev)
1427 {
1428         struct ccw_device *cdev;
1429
1430         cdev = to_ccwdev(dev);
1431         if (cdev->drv && cdev->drv->shutdown)
1432                 cdev->drv->shutdown(cdev);
1433         disable_cmf(cdev);
1434 }
1435
1436 struct bus_type ccw_bus_type = {
1437         .name   = "ccw",
1438         .match  = ccw_bus_match,
1439         .uevent = ccw_uevent,
1440         .probe  = ccw_device_probe,
1441         .remove = ccw_device_remove,
1442         .shutdown = ccw_device_shutdown,
1443 };
1444
1445 /**
1446  * ccw_driver_register() - register a ccw driver
1447  * @cdriver: driver to be registered
1448  *
1449  * This function is mainly a wrapper around driver_register().
1450  * Returns:
1451  *   %0 on success and a negative error value on failure.
1452  */
1453 int ccw_driver_register(struct ccw_driver *cdriver)
1454 {
1455         struct device_driver *drv = &cdriver->driver;
1456
1457         drv->bus = &ccw_bus_type;
1458         drv->name = cdriver->name;
1459
1460         return driver_register(drv);
1461 }
1462
1463 /**
1464  * ccw_driver_unregister() - deregister a ccw driver
1465  * @cdriver: driver to be deregistered
1466  *
1467  * This function is mainly a wrapper around driver_unregister().
1468  */
1469 void ccw_driver_unregister(struct ccw_driver *cdriver)
1470 {
1471         driver_unregister(&cdriver->driver);
1472 }
1473
1474 /* Helper func for qdio. */
1475 struct subchannel_id
1476 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1477 {
1478         struct subchannel *sch;
1479
1480         sch = to_subchannel(cdev->dev.parent);
1481         return sch->schid;
1482 }
1483
1484 MODULE_LICENSE("GPL");
1485 EXPORT_SYMBOL(ccw_device_set_online);
1486 EXPORT_SYMBOL(ccw_device_set_offline);
1487 EXPORT_SYMBOL(ccw_driver_register);
1488 EXPORT_SYMBOL(ccw_driver_unregister);
1489 EXPORT_SYMBOL(get_ccwdev_by_busid);
1490 EXPORT_SYMBOL(ccw_bus_type);
1491 EXPORT_SYMBOL(ccw_device_work);
1492 EXPORT_SYMBOL(ccw_device_notify_work);
1493 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);