drivers/s390/cio/device.c

   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, char **envp, int num_envp,
  83                       char *buffer, int buffer_size)
  84 {
  85         struct ccw_device *cdev = to_ccwdev(dev);
  86         struct ccw_device_id *id = &(cdev->id);
  87         int i = 0;
  88         int len = 0;
  89         int ret;
  90         char modalias_buf[30];
  91
  92         /* CU_TYPE= */
  93         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
  94                              "CU_TYPE=%04X", id->cu_type);
  95         if (ret)
  96                 return ret;
  97
  98         /* CU_MODEL= */
  99         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 100                              "CU_MODEL=%02X", id->cu_model);
 101         if (ret)
 102                 return ret;
 103
 104         /* The next two can be zero, that's ok for us */
 105         /* DEV_TYPE= */
 106         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 107                              "DEV_TYPE=%04X", id->dev_type);
 108         if (ret)
 109                 return ret;
 110
 111         /* DEV_MODEL= */
 112         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 113                              "DEV_MODEL=%02X", id->dev_model);
 114         if (ret)
 115                 return ret;
 116
 117         /* MODALIAS=  */
 118         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 119         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 120                              "MODALIAS=%s", modalias_buf);
 121         if (ret)
 122                 return ret;
 123         envp[i] = NULL;
 124         return 0;
 125 }
 126
 127 struct bus_type ccw_bus_type;
 128
 129 static int io_subchannel_probe (struct subchannel *);
 130 static int io_subchannel_remove (struct subchannel *);
 131 static int io_subchannel_notify(struct device *, int);
 132 static void io_subchannel_verify(struct device *);
 133 static void io_subchannel_ioterm(struct device *);
 134 static void io_subchannel_shutdown(struct subchannel *);
 135
 136 static struct css_driver io_subchannel_driver = {
 137         .subchannel_type = SUBCHANNEL_TYPE_IO,
 138         .drv = {
 139                 .name = "io_subchannel",
 140                 .bus  = &css_bus_type,
 141         },
 142         .irq = io_subchannel_irq,
 143         .notify = io_subchannel_notify,
 144         .verify = io_subchannel_verify,
 145         .termination = io_subchannel_ioterm,
 146         .probe = io_subchannel_probe,
 147         .remove = io_subchannel_remove,
 148         .shutdown = io_subchannel_shutdown,
 149 };
 150
 151 struct workqueue_struct *ccw_device_work;
 152 struct workqueue_struct *ccw_device_notify_work;
 153 wait_queue_head_t ccw_device_init_wq;
 154 atomic_t ccw_device_init_count;
 155
 156 static int __init
 157 init_ccw_bus_type (void)
 158 {
 159         int ret;
 160
 161         init_waitqueue_head(&ccw_device_init_wq);
 162         atomic_set(&ccw_device_init_count, 0);
 163
 164         ccw_device_work = create_singlethread_workqueue("cio");
 165         if (!ccw_device_work)
 166                 return -ENOMEM; /* FIXME: better errno ? */
 167         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 168         if (!ccw_device_notify_work) {
 169                 ret = -ENOMEM; /* FIXME: better errno ? */
 170                 goto out_err;
 171         }
 172         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 173         if (!slow_path_wq) {
 174                 ret = -ENOMEM; /* FIXME: better errno ? */
 175                 goto out_err;
 176         }
 177         if ((ret = bus_register (&ccw_bus_type)))
 178                 goto out_err;
 179
 180         if ((ret = driver_register(&io_subchannel_driver.drv)))
 181                 goto out_err;
 182
 183         wait_event(ccw_device_init_wq,
 184                    atomic_read(&ccw_device_init_count) == 0);
 185         flush_workqueue(ccw_device_work);
 186         return 0;
 187 out_err:
 188         if (ccw_device_work)
 189                 destroy_workqueue(ccw_device_work);
 190         if (ccw_device_notify_work)
 191                 destroy_workqueue(ccw_device_notify_work);
 192         if (slow_path_wq)
 193                 destroy_workqueue(slow_path_wq);
 194         return ret;
 195 }
 196
 197 static void __exit
 198 cleanup_ccw_bus_type (void)
 199 {
 200         driver_unregister(&io_subchannel_driver.drv);
 201         bus_unregister(&ccw_bus_type);
 202         destroy_workqueue(ccw_device_notify_work);
 203         destroy_workqueue(ccw_device_work);
 204 }
 205
 206 subsys_initcall(init_ccw_bus_type);
 207 module_exit(cleanup_ccw_bus_type);
 208
 209 /************************ device handling **************************/
 210
 211 /*
 212  * A ccw_device has some interfaces in sysfs in addition to the
 213  * standard ones.
 214  * The following entries are designed to export the information which
 215  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 216  * are obvious, so they don't have an entry :)
 217  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 218  */
 219 static ssize_t
 220 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 221 {
 222         struct subchannel *sch = to_subchannel(dev);
 223         struct chsc_ssd_info *ssd = &sch->ssd_info;
 224         ssize_t ret = 0;
 225         int chp;
 226         int mask;
 227
 228         for (chp = 0; chp < 8; chp++) {
 229                 mask = 0x80 >> chp;
 230                 if (ssd->path_mask & mask)
 231                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 232                 else
 233                         ret += sprintf(buf + ret, "00 ");
 234         }
 235         ret += sprintf (buf+ret, "\n");
 236         return min((ssize_t)PAGE_SIZE, ret);
 237 }
 238
 239 static ssize_t
 240 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 241 {
 242         struct subchannel *sch = to_subchannel(dev);
 243         struct pmcw *pmcw = &sch->schib.pmcw;
 244
 245         return sprintf (buf, "%02x %02x %02x\n",
 246                         pmcw->pim, pmcw->pam, pmcw->pom);
 247 }
 248
 249 static ssize_t
 250 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 251 {
 252         struct ccw_device *cdev = to_ccwdev(dev);
 253         struct ccw_device_id *id = &(cdev->id);
 254
 255         if (id->dev_type != 0)
 256                 return sprintf(buf, "%04x/%02x\n",
 257                                 id->dev_type, id->dev_model);
 258         else
 259                 return sprintf(buf, "n/a\n");
 260 }
 261
 262 static ssize_t
 263 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 264 {
 265         struct ccw_device *cdev = to_ccwdev(dev);
 266         struct ccw_device_id *id = &(cdev->id);
 267
 268         return sprintf(buf, "%04x/%02x\n",
 269                        id->cu_type, id->cu_model);
 270 }
 271
 272 static ssize_t
 273 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 274 {
 275         struct ccw_device *cdev = to_ccwdev(dev);
 276         struct ccw_device_id *id = &(cdev->id);
 277         int len;
 278
 279         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 280
 281         return len > PAGE_SIZE ? PAGE_SIZE : len;
 282 }
 283
 284 static ssize_t
 285 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 286 {
 287         struct ccw_device *cdev = to_ccwdev(dev);
 288
 289         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 290 }
 291
 292 int ccw_device_is_orphan(struct ccw_device *cdev)
 293 {
 294         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 295 }
 296
 297 static void ccw_device_unregister(struct ccw_device *cdev)
 298 {
 299         if (test_and_clear_bit(1, &cdev->private->registered))
 300                 device_del(&cdev->dev);
 301 }
 302
 303 static void ccw_device_remove_orphan_cb(struct device *dev)
 304 {
 305         struct ccw_device *cdev = to_ccwdev(dev);
 306
 307         ccw_device_unregister(cdev);
 308         put_device(&cdev->dev);
 309 }
 310
 311 static void ccw_device_remove_sch_cb(struct device *dev)
 312 {
 313         struct subchannel *sch;
 314
 315         sch = to_subchannel(dev);
 316         css_sch_device_unregister(sch);
 317         /* Reset intparm to zeroes. */
 318         sch->schib.pmcw.intparm = 0;
 319         cio_modify(sch);
 320         put_device(&sch->dev);
 321 }
 322
 323 static void
 324 ccw_device_remove_disconnected(struct ccw_device *cdev)
 325 {
 326         unsigned long flags;
 327         int rc;
 328
 329         /*
 330          * Forced offline in disconnected state means
 331          * 'throw away device'.
 332          */
 333         if (ccw_device_is_orphan(cdev)) {
 334                 /*
 335                  * Deregister ccw device.
 336                  * Unfortunately, we cannot do this directly from the
 337                  * attribute method.
 338                  */
 339                 spin_lock_irqsave(cdev->ccwlock, flags);
 340                 cdev->private->state = DEV_STATE_NOT_OPER;
 341                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 342                 rc = device_schedule_callback(&cdev->dev,
 343                                               ccw_device_remove_orphan_cb);
 344                 if (rc)
 345                         CIO_MSG_EVENT(2, "Couldn't unregister orphan "
 346                                       "0.%x.%04x\n",
 347                                       cdev->private->dev_id.ssid,
 348                                       cdev->private->dev_id.devno);
 349                 return;
 350         }
 351         /* Deregister subchannel, which will kill the ccw device. */
 352         rc = device_schedule_callback(cdev->dev.parent,
 353                                       ccw_device_remove_sch_cb);
 354         if (rc)
 355                 CIO_MSG_EVENT(2, "Couldn't unregister disconnected device "
 356                               "0.%x.%04x\n",
 357                               cdev->private->dev_id.ssid,
 358                               cdev->private->dev_id.devno);
 359 }
 360
 361 /**
 362  * ccw_device_set_offline() - disable a ccw device for I/O
 363  * @cdev: target ccw device
 364  *
 365  * This function calls the driver's set_offline() function for @cdev, if
 366  * given, and then disables @cdev.
 367  * Returns:
 368  *   %0 on success and a negative error value on failure.
 369  * Context:
 370  *  enabled, ccw device lock not held
 371  */
 372 int ccw_device_set_offline(struct ccw_device *cdev)
 373 {
 374         int ret;
 375
 376         if (!cdev)
 377                 return -ENODEV;
 378         if (!cdev->online || !cdev->drv)
 379                 return -EINVAL;
 380
 381         if (cdev->drv->set_offline) {
 382                 ret = cdev->drv->set_offline(cdev);
 383                 if (ret != 0)
 384                         return ret;
 385         }
 386         cdev->online = 0;
 387         spin_lock_irq(cdev->ccwlock);
 388         ret = ccw_device_offline(cdev);
 389         if (ret == -ENODEV) {
 390                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 391                         cdev->private->state = DEV_STATE_OFFLINE;
 392                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 393                 }
 394                 spin_unlock_irq(cdev->ccwlock);
 395                 return ret;
 396         }
 397         spin_unlock_irq(cdev->ccwlock);
 398         if (ret == 0)
 399                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 400         else {
 401                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
 402                               "device 0.%x.%04x\n",
 403                               ret, cdev->private->dev_id.ssid,
 404                               cdev->private->dev_id.devno);
 405                 cdev->online = 1;
 406         }
 407         return ret;
 408 }
 409
 410 /**
 411  * ccw_device_set_online() - enable a ccw device for I/O
 412  * @cdev: target ccw device
 413  *
 414  * This function first enables @cdev and then calls the driver's set_online()
 415  * function for @cdev, if given. If set_online() returns an error, @cdev is
 416  * disabled again.
 417  * Returns:
 418  *   %0 on success and a negative error value on failure.
 419  * Context:
 420  *  enabled, ccw device lock not held
 421  */
 422 int ccw_device_set_online(struct ccw_device *cdev)
 423 {
 424         int ret;
 425
 426         if (!cdev)
 427                 return -ENODEV;
 428         if (cdev->online || !cdev->drv)
 429                 return -EINVAL;
 430
 431         spin_lock_irq(cdev->ccwlock);
 432         ret = ccw_device_online(cdev);
 433         spin_unlock_irq(cdev->ccwlock);
 434         if (ret == 0)
 435                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 436         else {
 437                 CIO_MSG_EVENT(2, "ccw_device_online returned %d, "
 438                               "device 0.%x.%04x\n",
 439                               ret, cdev->private->dev_id.ssid,
 440                               cdev->private->dev_id.devno);
 441                 return ret;
 442         }
 443         if (cdev->private->state != DEV_STATE_ONLINE)
 444                 return -ENODEV;
 445         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 446                 cdev->online = 1;
 447                 return 0;
 448         }
 449         spin_lock_irq(cdev->ccwlock);
 450         ret = ccw_device_offline(cdev);
 451         spin_unlock_irq(cdev->ccwlock);
 452         if (ret == 0)
 453                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 454         else
 455                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
 456                               "device 0.%x.%04x\n",
 457                               ret, cdev->private->dev_id.ssid,
 458                               cdev->private->dev_id.devno);
 459         return (ret == 0) ? -ENODEV : ret;
 460 }
 461
 462 static void online_store_handle_offline(struct ccw_device *cdev)
 463 {
 464         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 465                 ccw_device_remove_disconnected(cdev);
 466         else if (cdev->drv && cdev->drv->set_offline)
 467                 ccw_device_set_offline(cdev);
 468 }
 469
 470 static int online_store_recog_and_online(struct ccw_device *cdev)
 471 {
 472         int ret;
 473
 474         /* Do device recognition, if needed. */
 475         if (cdev->id.cu_type == 0) {
 476                 ret = ccw_device_recognition(cdev);
 477                 if (ret) {
 478                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 479                                       "for device 0.%x.%04x (ret=%d)\n",
 480                                       cdev->private->dev_id.ssid,
 481                                       cdev->private->dev_id.devno, ret);
 482                         return ret;
 483                 }
 484                 wait_event(cdev->private->wait_q,
 485                            cdev->private->flags.recog_done);
 486         }
 487         if (cdev->drv && cdev->drv->set_online)
 488                 ccw_device_set_online(cdev);
 489         return 0;
 490 }
 491 static void online_store_handle_online(struct ccw_device *cdev, int force)
 492 {
 493         int ret;
 494
 495         ret = online_store_recog_and_online(cdev);
 496         if (ret)
 497                 return;
 498         if (force && cdev->private->state == DEV_STATE_BOXED) {
 499                 ret = ccw_device_stlck(cdev);
 500                 if (ret) {
 501                         dev_warn(&cdev->dev,
 502                                  "ccw_device_stlck returned %d!\n", ret);
 503                         return;
 504                 }
 505                 if (cdev->id.cu_type == 0)
 506                         cdev->private->state = DEV_STATE_NOT_OPER;
 507                 online_store_recog_and_online(cdev);
 508         }
 509
 510 }
 511
 512 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 513                              const char *buf, size_t count)
 514 {
 515         struct ccw_device *cdev = to_ccwdev(dev);
 516         int i, force;
 517         char *tmp;
 518
 519         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 520                 return -EAGAIN;
 521
 522         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 523                 atomic_set(&cdev->private->onoff, 0);
 524                 return -EINVAL;
 525         }
 526         if (!strncmp(buf, "force\n", count)) {
 527                 force = 1;
 528                 i = 1;
 529         } else {
 530                 force = 0;
 531                 i = simple_strtoul(buf, &tmp, 16);
 532         }
 533
 534         switch (i) {
 535         case 0:
 536                 online_store_handle_offline(cdev);
 537                 break;
 538         case 1:
 539                 online_store_handle_online(cdev, force);
 540                 break;
 541         default:
 542                 count = -EINVAL;
 543         }
 544         if (cdev->drv)
 545                 module_put(cdev->drv->owner);
 546         atomic_set(&cdev->private->onoff, 0);
 547         return count;
 548 }
 549
 550 static ssize_t
 551 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 552 {
 553         struct ccw_device *cdev = to_ccwdev(dev);
 554         struct subchannel *sch;
 555
 556         if (ccw_device_is_orphan(cdev))
 557                 return sprintf(buf, "no device\n");
 558         switch (cdev->private->state) {
 559         case DEV_STATE_BOXED:
 560                 return sprintf(buf, "boxed\n");
 561         case DEV_STATE_DISCONNECTED:
 562         case DEV_STATE_DISCONNECTED_SENSE_ID:
 563         case DEV_STATE_NOT_OPER:
 564                 sch = to_subchannel(dev->parent);
 565                 if (!sch->lpm)
 566                         return sprintf(buf, "no path\n");
 567                 else
 568                         return sprintf(buf, "no device\n");
 569         default:
 570                 /* All other states considered fine. */
 571                 return sprintf(buf, "good\n");
 572         }
 573 }
 574
 575 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 576 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 577 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 578 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 579 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 580 static DEVICE_ATTR(online, 0644, online_show, online_store);
 581 extern struct device_attribute dev_attr_cmb_enable;
 582 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 583
 584 static struct attribute * subch_attrs[] = {
 585         &dev_attr_chpids.attr,
 586         &dev_attr_pimpampom.attr,
 587         NULL,
 588 };
 589
 590 static struct attribute_group subch_attr_group = {
 591         .attrs = subch_attrs,
 592 };
 593
 594 struct attribute_group *subch_attr_groups[] = {
 595         &subch_attr_group,
 596         NULL,
 597 };
 598
 599 static struct attribute * ccwdev_attrs[] = {
 600         &dev_attr_devtype.attr,
 601         &dev_attr_cutype.attr,
 602         &dev_attr_modalias.attr,
 603         &dev_attr_online.attr,
 604         &dev_attr_cmb_enable.attr,
 605         &dev_attr_availability.attr,
 606         NULL,
 607 };
 608
 609 static struct attribute_group ccwdev_attr_group = {
 610         .attrs = ccwdev_attrs,
 611 };
 612
 613 static struct attribute_group *ccwdev_attr_groups[] = {
 614         &ccwdev_attr_group,
 615         NULL,
 616 };
 617
 618 /* this is a simple abstraction for device_register that sets the
 619  * correct bus type and adds the bus specific files */
 620 static int ccw_device_register(struct ccw_device *cdev)
 621 {
 622         struct device *dev = &cdev->dev;
 623         int ret;
 624
 625         dev->bus = &ccw_bus_type;
 626
 627         if ((ret = device_add(dev)))
 628                 return ret;
 629
 630         set_bit(1, &cdev->private->registered);
 631         return ret;
 632 }
 633
 634 struct match_data {
 635         struct ccw_dev_id dev_id;
 636         struct ccw_device * sibling;
 637 };
 638
 639 static int
 640 match_devno(struct device * dev, void * data)
 641 {
 642         struct match_data * d = data;
 643         struct ccw_device * cdev;
 644
 645         cdev = to_ccwdev(dev);
 646         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 647             !ccw_device_is_orphan(cdev) &&
 648             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 649             (cdev != d->sibling))
 650                 return 1;
 651         return 0;
 652 }
 653
 654 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 655                                                      struct ccw_device *sibling)
 656 {
 657         struct device *dev;
 658         struct match_data data;
 659
 660         data.dev_id = *dev_id;
 661         data.sibling = sibling;
 662         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 663
 664         return dev ? to_ccwdev(dev) : NULL;
 665 }
 666
 667 static int match_orphan(struct device *dev, void *data)
 668 {
 669         struct ccw_dev_id *dev_id;
 670         struct ccw_device *cdev;
 671
 672         dev_id = data;
 673         cdev = to_ccwdev(dev);
 674         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 675 }
 676
 677 static struct ccw_device *
 678 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 679                               struct ccw_dev_id *dev_id)
 680 {
 681         struct device *dev;
 682
 683         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 684                                 match_orphan);
 685
 686         return dev ? to_ccwdev(dev) : NULL;
 687 }
 688
 689 static void
 690 ccw_device_add_changed(struct work_struct *work)
 691 {
 692         struct ccw_device_private *priv;
 693         struct ccw_device *cdev;
 694
 695         priv = container_of(work, struct ccw_device_private, kick_work);
 696         cdev = priv->cdev;
 697         if (device_add(&cdev->dev)) {
 698                 put_device(&cdev->dev);
 699                 return;
 700         }
 701         set_bit(1, &cdev->private->registered);
 702 }
 703
 704 void ccw_device_do_unreg_rereg(struct work_struct *work)
 705 {
 706         struct ccw_device_private *priv;
 707         struct ccw_device *cdev;
 708         struct subchannel *sch;
 709
 710         priv = container_of(work, struct ccw_device_private, kick_work);
 711         cdev = priv->cdev;
 712         sch = to_subchannel(cdev->dev.parent);
 713
 714         ccw_device_unregister(cdev);
 715         PREPARE_WORK(&cdev->private->kick_work,
 716                      ccw_device_add_changed);
 717         queue_work(ccw_device_work, &cdev->private->kick_work);
 718 }
 719
 720 static void
 721 ccw_device_release(struct device *dev)
 722 {
 723         struct ccw_device *cdev;
 724
 725         cdev = to_ccwdev(dev);
 726         kfree(cdev->private);
 727         kfree(cdev);
 728 }
 729
 730 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 731 {
 732         struct ccw_device *cdev;
 733
 734         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 735         if (cdev) {
 736                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 737                                         GFP_KERNEL | GFP_DMA);
 738                 if (cdev->private)
 739                         return cdev;
 740         }
 741         kfree(cdev);
 742         return ERR_PTR(-ENOMEM);
 743 }
 744
 745 static int io_subchannel_initialize_dev(struct subchannel *sch,
 746                                         struct ccw_device *cdev)
 747 {
 748         cdev->private->cdev = cdev;
 749         atomic_set(&cdev->private->onoff, 0);
 750         cdev->dev.parent = &sch->dev;
 751         cdev->dev.release = ccw_device_release;
 752         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 753         cdev->dev.groups = ccwdev_attr_groups;
 754         /* Do first half of device_register. */
 755         device_initialize(&cdev->dev);
 756         if (!get_device(&sch->dev)) {
 757                 if (cdev->dev.release)
 758                         cdev->dev.release(&cdev->dev);
 759                 return -ENODEV;
 760         }
 761         return 0;
 762 }
 763
 764 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 765 {
 766         struct ccw_device *cdev;
 767         int ret;
 768
 769         cdev = io_subchannel_allocate_dev(sch);
 770         if (!IS_ERR(cdev)) {
 771                 ret = io_subchannel_initialize_dev(sch, cdev);
 772                 if (ret) {
 773                         kfree(cdev);
 774                         cdev = ERR_PTR(ret);
 775                 }
 776         }
 777         return cdev;
 778 }
 779
 780 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 781
 782 static void sch_attach_device(struct subchannel *sch,
 783                               struct ccw_device *cdev)
 784 {
 785         css_update_ssd_info(sch);
 786         spin_lock_irq(sch->lock);
 787         sch->dev.driver_data = cdev;
 788         cdev->private->schid = sch->schid;
 789         cdev->ccwlock = sch->lock;
 790         device_trigger_reprobe(sch);
 791         spin_unlock_irq(sch->lock);
 792 }
 793
 794 static void sch_attach_disconnected_device(struct subchannel *sch,
 795                                            struct ccw_device *cdev)
 796 {
 797         struct subchannel *other_sch;
 798         int ret;
 799
 800         other_sch = to_subchannel(get_device(cdev->dev.parent));
 801         ret = device_move(&cdev->dev, &sch->dev);
 802         if (ret) {
 803                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
 804                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 805                               cdev->private->dev_id.devno, ret);
 806                 put_device(&other_sch->dev);
 807                 return;
 808         }
 809         other_sch->dev.driver_data = NULL;
 810         /* No need to keep a subchannel without ccw device around. */
 811         css_sch_device_unregister(other_sch);
 812         put_device(&other_sch->dev);
 813         sch_attach_device(sch, cdev);
 814 }
 815
 816 static void sch_attach_orphaned_device(struct subchannel *sch,
 817                                        struct ccw_device *cdev)
 818 {
 819         int ret;
 820
 821         /* Try to move the ccw device to its new subchannel. */
 822         ret = device_move(&cdev->dev, &sch->dev);
 823         if (ret) {
 824                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 825                               "failed (ret=%d)!\n",
 826                               cdev->private->dev_id.ssid,
 827                               cdev->private->dev_id.devno, ret);
 828                 return;
 829         }
 830         sch_attach_device(sch, cdev);
 831 }
 832
 833 static void sch_create_and_recog_new_device(struct subchannel *sch)
 834 {
 835         struct ccw_device *cdev;
 836
 837         /* Need to allocate a new ccw device. */
 838         cdev = io_subchannel_create_ccwdev(sch);
 839         if (IS_ERR(cdev)) {
 840                 /* OK, we did everything we could... */
 841                 css_sch_device_unregister(sch);
 842                 return;
 843         }
 844         spin_lock_irq(sch->lock);
 845         sch->dev.driver_data = cdev;
 846         spin_unlock_irq(sch->lock);
 847         /* Start recognition for the new ccw device. */
 848         if (io_subchannel_recog(cdev, sch)) {
 849                 spin_lock_irq(sch->lock);
 850                 sch->dev.driver_data = NULL;
 851                 spin_unlock_irq(sch->lock);
 852                 if (cdev->dev.release)
 853                         cdev->dev.release(&cdev->dev);
 854                 css_sch_device_unregister(sch);
 855         }
 856 }
 857
 858
 859 void ccw_device_move_to_orphanage(struct work_struct *work)
 860 {
 861         struct ccw_device_private *priv;
 862         struct ccw_device *cdev;
 863         struct ccw_device *replacing_cdev;
 864         struct subchannel *sch;
 865         int ret;
 866         struct channel_subsystem *css;
 867         struct ccw_dev_id dev_id;
 868
 869         priv = container_of(work, struct ccw_device_private, kick_work);
 870         cdev = priv->cdev;
 871         sch = to_subchannel(cdev->dev.parent);
 872         css = to_css(sch->dev.parent);
 873         dev_id.devno = sch->schib.pmcw.dev;
 874         dev_id.ssid = sch->schid.ssid;
 875
 876         /*
 877          * Move the orphaned ccw device to the orphanage so the replacing
 878          * ccw device can take its place on the subchannel.
 879          */
 880         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 881         if (ret) {
 882                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 883                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 884                               cdev->private->dev_id.devno, ret);
 885                 return;
 886         }
 887         cdev->ccwlock = css->pseudo_subchannel->lock;
 888         /*
 889          * Search for the replacing ccw device
 890          * - among the disconnected devices
 891          * - in the orphanage
 892          */
 893         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 894         if (replacing_cdev) {
 895                 sch_attach_disconnected_device(sch, replacing_cdev);
 896                 return;
 897         }
 898         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 899         if (replacing_cdev) {
 900                 sch_attach_orphaned_device(sch, replacing_cdev);
 901                 return;
 902         }
 903         sch_create_and_recog_new_device(sch);
 904 }
 905
 906 /*
 907  * Register recognized device.
 908  */
 909 static void
 910 io_subchannel_register(struct work_struct *work)
 911 {
 912         struct ccw_device_private *priv;
 913         struct ccw_device *cdev;
 914         struct subchannel *sch;
 915         int ret;
 916         unsigned long flags;
 917
 918         priv = container_of(work, struct ccw_device_private, kick_work);
 919         cdev = priv->cdev;
 920         sch = to_subchannel(cdev->dev.parent);
 921         css_update_ssd_info(sch);
 922         /*
 923          * io_subchannel_register() will also be called after device
 924          * recognition has been done for a boxed device (which will already
 925          * be registered). We need to reprobe since we may now have sense id
 926          * information.
 927          */
 928         if (klist_node_attached(&cdev->dev.knode_parent)) {
 929                 if (!cdev->drv) {
 930                         ret = device_reprobe(&cdev->dev);
 931                         if (ret)
 932                                 /* We can't do much here. */
 933                                 CIO_MSG_EVENT(2, "device_reprobe() returned"
 934                                               " %d for 0.%x.%04x\n", ret,
 935                                               cdev->private->dev_id.ssid,
 936                                               cdev->private->dev_id.devno);
 937                 }
 938                 goto out;
 939         }
 940         /*
 941          * Now we know this subchannel will stay, we can throw
 942          * our delayed uevent.
 943          */
 944         sch->dev.uevent_suppress = 0;
 945         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 946         /* make it known to the system */
 947         ret = ccw_device_register(cdev);
 948         if (ret) {
 949                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 950                               cdev->private->dev_id.ssid,
 951                               cdev->private->dev_id.devno, ret);
 952                 put_device(&cdev->dev);
 953                 spin_lock_irqsave(sch->lock, flags);
 954                 sch->dev.driver_data = NULL;
 955                 spin_unlock_irqrestore(sch->lock, flags);
 956                 kfree (cdev->private);
 957                 kfree (cdev);
 958                 put_device(&sch->dev);
 959                 if (atomic_dec_and_test(&ccw_device_init_count))
 960                         wake_up(&ccw_device_init_wq);
 961                 return;
 962         }
 963         put_device(&cdev->dev);
 964 out:
 965         cdev->private->flags.recog_done = 1;
 966         put_device(&sch->dev);
 967         wake_up(&cdev->private->wait_q);
 968         if (atomic_dec_and_test(&ccw_device_init_count))
 969                 wake_up(&ccw_device_init_wq);
 970 }
 971
 972 void
 973 ccw_device_call_sch_unregister(struct work_struct *work)
 974 {
 975         struct ccw_device_private *priv;
 976         struct ccw_device *cdev;
 977         struct subchannel *sch;
 978
 979         priv = container_of(work, struct ccw_device_private, kick_work);
 980         cdev = priv->cdev;
 981         sch = to_subchannel(cdev->dev.parent);
 982         css_sch_device_unregister(sch);
 983         /* Reset intparm to zeroes. */
 984         sch->schib.pmcw.intparm = 0;
 985         cio_modify(sch);
 986         put_device(&cdev->dev);
 987         put_device(&sch->dev);
 988 }
 989
 990 /*
 991  * subchannel recognition done. Called from the state machine.
 992  */
 993 void
 994 io_subchannel_recog_done(struct ccw_device *cdev)
 995 {
 996         struct subchannel *sch;
 997
 998         if (css_init_done == 0) {
 999                 cdev->private->flags.recog_done = 1;
1000                 return;
1001         }
1002         switch (cdev->private->state) {
1003         case DEV_STATE_NOT_OPER:
1004                 cdev->private->flags.recog_done = 1;
1005                 /* Remove device found not operational. */
1006                 if (!get_device(&cdev->dev))
1007                         break;
1008                 sch = to_subchannel(cdev->dev.parent);
1009                 PREPARE_WORK(&cdev->private->kick_work,
1010                              ccw_device_call_sch_unregister);
1011                 queue_work(slow_path_wq, &cdev->private->kick_work);
1012                 if (atomic_dec_and_test(&ccw_device_init_count))
1013                         wake_up(&ccw_device_init_wq);
1014                 break;
1015         case DEV_STATE_BOXED:
1016                 /* Device did not respond in time. */
1017         case DEV_STATE_OFFLINE:
1018                 /*
1019                  * We can't register the device in interrupt context so
1020                  * we schedule a work item.
1021                  */
1022                 if (!get_device(&cdev->dev))
1023                         break;
1024                 PREPARE_WORK(&cdev->private->kick_work,
1025                              io_subchannel_register);
1026                 queue_work(slow_path_wq, &cdev->private->kick_work);
1027                 break;
1028         }
1029 }
1030
1031 static int
1032 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1033 {
1034         int rc;
1035         struct ccw_device_private *priv;
1036
1037         sch->dev.driver_data = cdev;
1038         sch->driver = &io_subchannel_driver;
1039         cdev->ccwlock = sch->lock;
1040
1041         /* Init private data. */
1042         priv = cdev->private;
1043         priv->dev_id.devno = sch->schib.pmcw.dev;
1044         priv->dev_id.ssid = sch->schid.ssid;
1045         priv->schid = sch->schid;
1046         priv->state = DEV_STATE_NOT_OPER;
1047         INIT_LIST_HEAD(&priv->cmb_list);
1048         init_waitqueue_head(&priv->wait_q);
1049         init_timer(&priv->timer);
1050
1051         /* Set an initial name for the device. */
1052         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1053                   sch->schid.ssid, sch->schib.pmcw.dev);
1054
1055         /* Increase counter of devices currently in recognition. */
1056         atomic_inc(&ccw_device_init_count);
1057
1058         /* Start async. device sensing. */
1059         spin_lock_irq(sch->lock);
1060         rc = ccw_device_recognition(cdev);
1061         spin_unlock_irq(sch->lock);
1062         if (rc) {
1063                 if (atomic_dec_and_test(&ccw_device_init_count))
1064                         wake_up(&ccw_device_init_wq);
1065         }
1066         return rc;
1067 }
1068
1069 static void ccw_device_move_to_sch(struct work_struct *work)
1070 {
1071         struct ccw_device_private *priv;
1072         int rc;
1073         struct subchannel *sch;
1074         struct ccw_device *cdev;
1075         struct subchannel *former_parent;
1076
1077         priv = container_of(work, struct ccw_device_private, kick_work);
1078         sch = priv->sch;
1079         cdev = priv->cdev;
1080         former_parent = ccw_device_is_orphan(cdev) ?
1081                 NULL : to_subchannel(get_device(cdev->dev.parent));
1082         mutex_lock(&sch->reg_mutex);
1083         /* Try to move the ccw device to its new subchannel. */
1084         rc = device_move(&cdev->dev, &sch->dev);
1085         mutex_unlock(&sch->reg_mutex);
1086         if (rc) {
1087                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1088                               "0.%x.%04x failed (ret=%d)!\n",
1089                               cdev->private->dev_id.ssid,
1090                               cdev->private->dev_id.devno, sch->schid.ssid,
1091                               sch->schid.sch_no, rc);
1092                 css_sch_device_unregister(sch);
1093                 goto out;
1094         }
1095         if (former_parent) {
1096                 spin_lock_irq(former_parent->lock);
1097                 former_parent->dev.driver_data = NULL;
1098                 spin_unlock_irq(former_parent->lock);
1099                 css_sch_device_unregister(former_parent);
1100                 /* Reset intparm to zeroes. */
1101                 former_parent->schib.pmcw.intparm = 0;
1102                 cio_modify(former_parent);
1103         }
1104         sch_attach_device(sch, cdev);
1105 out:
1106         if (former_parent)
1107                 put_device(&former_parent->dev);
1108         put_device(&cdev->dev);
1109 }
1110
1111 static int
1112 io_subchannel_probe (struct subchannel *sch)
1113 {
1114         struct ccw_device *cdev;
1115         int rc;
1116         unsigned long flags;
1117         struct ccw_dev_id dev_id;
1118
1119         if (sch->dev.driver_data) {
1120                 /*
1121                  * This subchannel already has an associated ccw_device.
1122                  * Register it and exit. This happens for all early
1123                  * device, e.g. the console.
1124                  */
1125                 cdev = sch->dev.driver_data;
1126                 cdev->dev.groups = ccwdev_attr_groups;
1127                 device_initialize(&cdev->dev);
1128                 ccw_device_register(cdev);
1129                 /*
1130                  * Check if the device is already online. If it is
1131                  * the reference count needs to be corrected
1132                  * (see ccw_device_online and css_init_done for the
1133                  * ugly details).
1134                  */
1135                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1136                     cdev->private->state != DEV_STATE_OFFLINE &&
1137                     cdev->private->state != DEV_STATE_BOXED)
1138                         get_device(&cdev->dev);
1139                 return 0;
1140         }
1141         /*
1142          * First check if a fitting device may be found amongst the
1143          * disconnected devices or in the orphanage.
1144          */
1145         dev_id.devno = sch->schib.pmcw.dev;
1146         dev_id.ssid = sch->schid.ssid;
1147         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1148         if (!cdev)
1149                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1150                                                      &dev_id);
1151         if (cdev) {
1152                 /*
1153                  * Schedule moving the device until when we have a registered
1154                  * subchannel to move to and succeed the probe. We can
1155                  * unregister later again, when the probe is through.
1156                  */
1157                 cdev->private->sch = sch;
1158                 PREPARE_WORK(&cdev->private->kick_work,
1159                              ccw_device_move_to_sch);
1160                 queue_work(slow_path_wq, &cdev->private->kick_work);
1161                 return 0;
1162         }
1163         cdev = io_subchannel_create_ccwdev(sch);
1164         if (IS_ERR(cdev))
1165                 return PTR_ERR(cdev);
1166
1167         rc = io_subchannel_recog(cdev, sch);
1168         if (rc) {
1169                 spin_lock_irqsave(sch->lock, flags);
1170                 sch->dev.driver_data = NULL;
1171                 spin_unlock_irqrestore(sch->lock, flags);
1172                 if (cdev->dev.release)
1173                         cdev->dev.release(&cdev->dev);
1174         }
1175
1176         return rc;
1177 }
1178
1179 static int
1180 io_subchannel_remove (struct subchannel *sch)
1181 {
1182         struct ccw_device *cdev;
1183         unsigned long flags;
1184
1185         if (!sch->dev.driver_data)
1186                 return 0;
1187         cdev = sch->dev.driver_data;
1188         /* Set ccw device to not operational and drop reference. */
1189         spin_lock_irqsave(cdev->ccwlock, flags);
1190         sch->dev.driver_data = NULL;
1191         cdev->private->state = DEV_STATE_NOT_OPER;
1192         spin_unlock_irqrestore(cdev->ccwlock, flags);
1193         ccw_device_unregister(cdev);
1194         put_device(&cdev->dev);
1195         return 0;
1196 }
1197
1198 static int
1199 io_subchannel_notify(struct device *dev, int event)
1200 {
1201         struct ccw_device *cdev;
1202
1203         cdev = dev->driver_data;
1204         if (!cdev)
1205                 return 0;
1206         if (!cdev->drv)
1207                 return 0;
1208         if (!cdev->online)
1209                 return 0;
1210         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1211 }
1212
1213 static void
1214 io_subchannel_verify(struct device *dev)
1215 {
1216         struct ccw_device *cdev;
1217
1218         cdev = dev->driver_data;
1219         if (cdev)
1220                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1221 }
1222
1223 static void
1224 io_subchannel_ioterm(struct device *dev)
1225 {
1226         struct ccw_device *cdev;
1227
1228         cdev = dev->driver_data;
1229         if (!cdev)
1230                 return;
1231         /* Internal I/O will be retried by the interrupt handler. */
1232         if (cdev->private->flags.intretry)
1233                 return;
1234         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1235         if (cdev->handler)
1236                 cdev->handler(cdev, cdev->private->intparm,
1237                               ERR_PTR(-EIO));
1238 }
1239
1240 static void
1241 io_subchannel_shutdown(struct subchannel *sch)
1242 {
1243         struct ccw_device *cdev;
1244         int ret;
1245
1246         cdev = sch->dev.driver_data;
1247
1248         if (cio_is_console(sch->schid))
1249                 return;
1250         if (!sch->schib.pmcw.ena)
1251                 /* Nothing to do. */
1252                 return;
1253         ret = cio_disable_subchannel(sch);
1254         if (ret != -EBUSY)
1255                 /* Subchannel is disabled, we're done. */
1256                 return;
1257         cdev->private->state = DEV_STATE_QUIESCE;
1258         if (cdev->handler)
1259                 cdev->handler(cdev, cdev->private->intparm,
1260                               ERR_PTR(-EIO));
1261         ret = ccw_device_cancel_halt_clear(cdev);
1262         if (ret == -EBUSY) {
1263                 ccw_device_set_timeout(cdev, HZ/10);
1264                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1265         }
1266         cio_disable_subchannel(sch);
1267 }
1268
1269 #ifdef CONFIG_CCW_CONSOLE
1270 static struct ccw_device console_cdev;
1271 static struct ccw_device_private console_private;
1272 static int console_cdev_in_use;
1273
1274 static DEFINE_SPINLOCK(ccw_console_lock);
1275
1276 spinlock_t * cio_get_console_lock(void)
1277 {
1278         return &ccw_console_lock;
1279 }
1280
1281 static int
1282 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1283 {
1284         int rc;
1285
1286         /* Initialize the ccw_device structure. */
1287         cdev->dev.parent= &sch->dev;
1288         rc = io_subchannel_recog(cdev, sch);
1289         if (rc)
1290                 return rc;
1291
1292         /* Now wait for the async. recognition to come to an end. */
1293         spin_lock_irq(cdev->ccwlock);
1294         while (!dev_fsm_final_state(cdev))
1295                 wait_cons_dev();
1296         rc = -EIO;
1297         if (cdev->private->state != DEV_STATE_OFFLINE)
1298                 goto out_unlock;
1299         ccw_device_online(cdev);
1300         while (!dev_fsm_final_state(cdev))
1301                 wait_cons_dev();
1302         if (cdev->private->state != DEV_STATE_ONLINE)
1303                 goto out_unlock;
1304         rc = 0;
1305 out_unlock:
1306         spin_unlock_irq(cdev->ccwlock);
1307         return 0;
1308 }
1309
1310 struct ccw_device *
1311 ccw_device_probe_console(void)
1312 {
1313         struct subchannel *sch;
1314         int ret;
1315
1316         if (xchg(&console_cdev_in_use, 1) != 0)
1317                 return ERR_PTR(-EBUSY);
1318         sch = cio_probe_console();
1319         if (IS_ERR(sch)) {
1320                 console_cdev_in_use = 0;
1321                 return (void *) sch;
1322         }
1323         memset(&console_cdev, 0, sizeof(struct ccw_device));
1324         memset(&console_private, 0, sizeof(struct ccw_device_private));
1325         console_cdev.private = &console_private;
1326         console_private.cdev = &console_cdev;
1327         ret = ccw_device_console_enable(&console_cdev, sch);
1328         if (ret) {
1329                 cio_release_console();
1330                 console_cdev_in_use = 0;
1331                 return ERR_PTR(ret);
1332         }
1333         console_cdev.online = 1;
1334         return &console_cdev;
1335 }
1336 #endif
1337
1338 /*
1339  * get ccw_device matching the busid, but only if owned by cdrv
1340  */
1341 static int
1342 __ccwdev_check_busid(struct device *dev, void *id)
1343 {
1344         char *bus_id;
1345
1346         bus_id = id;
1347
1348         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1349 }
1350
1351
1352 /**
1353  * get_ccwdev_by_busid() - obtain device from a bus id
1354  * @cdrv: driver the device is owned by
1355  * @bus_id: bus id of the device to be searched
1356  *
1357  * This function searches all devices owned by @cdrv for a device with a bus
1358  * id matching @bus_id.
1359  * Returns:
1360  *  If a match is found, its reference count of the found device is increased
1361  *  and it is returned; else %NULL is returned.
1362  */
1363 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1364                                        const char *bus_id)
1365 {
1366         struct device *dev;
1367         struct device_driver *drv;
1368
1369         drv = get_driver(&cdrv->driver);
1370         if (!drv)
1371                 return NULL;
1372
1373         dev = driver_find_device(drv, NULL, (void *)bus_id,
1374                                  __ccwdev_check_busid);
1375         put_driver(drv);
1376
1377         return dev ? to_ccwdev(dev) : NULL;
1378 }
1379
1380 /************************** device driver handling ************************/
1381
1382 /* This is the implementation of the ccw_driver class. The probe, remove
1383  * and release methods are initially very similar to the device_driver
1384  * implementations, with the difference that they have ccw_device
1385  * arguments.
1386  *
1387  * A ccw driver also contains the information that is needed for
1388  * device matching.
1389  */
1390 static int
1391 ccw_device_probe (struct device *dev)
1392 {
1393         struct ccw_device *cdev = to_ccwdev(dev);
1394         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1395         int ret;
1396
1397         cdev->drv = cdrv; /* to let the driver call _set_online */
1398
1399         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1400
1401         if (ret) {
1402                 cdev->drv = NULL;
1403                 return ret;
1404         }
1405
1406         return 0;
1407 }
1408
1409 static int
1410 ccw_device_remove (struct device *dev)
1411 {
1412         struct ccw_device *cdev = to_ccwdev(dev);
1413         struct ccw_driver *cdrv = cdev->drv;
1414         int ret;
1415
1416         if (cdrv->remove)
1417                 cdrv->remove(cdev);
1418         if (cdev->online) {
1419                 cdev->online = 0;
1420                 spin_lock_irq(cdev->ccwlock);
1421                 ret = ccw_device_offline(cdev);
1422                 spin_unlock_irq(cdev->ccwlock);
1423                 if (ret == 0)
1424                         wait_event(cdev->private->wait_q,
1425                                    dev_fsm_final_state(cdev));
1426                 else
1427                         //FIXME: we can't fail!
1428                         CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
1429                                       "device 0.%x.%04x\n",
1430                                       ret, cdev->private->dev_id.ssid,
1431                                       cdev->private->dev_id.devno);
1432         }
1433         ccw_device_set_timeout(cdev, 0);
1434         cdev->drv = NULL;
1435         return 0;
1436 }
1437
1438 static void ccw_device_shutdown(struct device *dev)
1439 {
1440         struct ccw_device *cdev;
1441
1442         cdev = to_ccwdev(dev);
1443         if (cdev->drv && cdev->drv->shutdown)
1444                 cdev->drv->shutdown(cdev);
1445         disable_cmf(cdev);
1446 }
1447
1448 struct bus_type ccw_bus_type = {
1449         .name   = "ccw",
1450         .match  = ccw_bus_match,
1451         .uevent = ccw_uevent,
1452         .probe  = ccw_device_probe,
1453         .remove = ccw_device_remove,
1454         .shutdown = ccw_device_shutdown,
1455 };
1456
1457 /**
1458  * ccw_driver_register() - register a ccw driver
1459  * @cdriver: driver to be registered
1460  *
1461  * This function is mainly a wrapper around driver_register().
1462  * Returns:
1463  *   %0 on success and a negative error value on failure.
1464  */
1465 int ccw_driver_register(struct ccw_driver *cdriver)
1466 {
1467         struct device_driver *drv = &cdriver->driver;
1468
1469         drv->bus = &ccw_bus_type;
1470         drv->name = cdriver->name;
1471
1472         return driver_register(drv);
1473 }
1474
1475 /**
1476  * ccw_driver_unregister() - deregister a ccw driver
1477  * @cdriver: driver to be deregistered
1478  *
1479  * This function is mainly a wrapper around driver_unregister().
1480  */
1481 void ccw_driver_unregister(struct ccw_driver *cdriver)
1482 {
1483         driver_unregister(&cdriver->driver);
1484 }
1485
1486 /* Helper func for qdio. */
1487 struct subchannel_id
1488 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1489 {
1490         struct subchannel *sch;
1491
1492         sch = to_subchannel(cdev->dev.parent);
1493         return sch->schid;
1494 }
1495
1496 MODULE_LICENSE("GPL");
1497 EXPORT_SYMBOL(ccw_device_set_online);
1498 EXPORT_SYMBOL(ccw_device_set_offline);
1499 EXPORT_SYMBOL(ccw_driver_register);
1500 EXPORT_SYMBOL(ccw_driver_unregister);
1501 EXPORT_SYMBOL(get_ccwdev_by_busid);
1502 EXPORT_SYMBOL(ccw_bus_type);
1503 EXPORT_SYMBOL(ccw_device_work);
1504 EXPORT_SYMBOL(ccw_device_notify_work);
1505 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);