drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.117 $
   5  *
   6  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   7  *                       IBM Corporation
   8  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   9  *               Cornelia Huck (cohuck@de.ibm.com)
  10  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  11  */
  12 #include <linux/config.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/slab.h>
  19 #include <linux/list.h>
  20 #include <linux/device.h>
  21 #include <linux/workqueue.h>
  22
  23 #include <asm/ccwdev.h>
  24 #include <asm/cio.h>
  25
  26 #include "cio.h"
  27 #include "css.h"
  28 #include "device.h"
  29 #include "ioasm.h"
  30
  31 /******************* bus type handling ***********************/
  32
  33 /* The Linux driver model distinguishes between a bus type and
  34  * the bus itself. Of course we only have one channel
  35  * subsystem driver and one channel system per machine, but
  36  * we still use the abstraction. T.R. says it's a good idea. */
  37 static int
  38 ccw_bus_match (struct device * dev, struct device_driver * drv)
  39 {
  40         struct ccw_device *cdev = to_ccwdev(dev);
  41         struct ccw_driver *cdrv = to_ccwdrv(drv);
  42         const struct ccw_device_id *ids = cdrv->ids, *found;
  43
  44         if (!ids)
  45                 return 0;
  46
  47         found = ccw_device_id_match(ids, &cdev->id);
  48         if (!found)
  49                 return 0;
  50
  51         cdev->id.driver_info = found->driver_info;
  52
  53         return 1;
  54 }
  55
  56 /*
  57  * Hotplugging interface for ccw devices.
  58  * Heavily modeled on pci and usb hotplug.
  59  */
  60 static int
  61 ccw_hotplug (struct device *dev, char **envp, int num_envp,
  62              char *buffer, int buffer_size)
  63 {
  64         struct ccw_device *cdev = to_ccwdev(dev);
  65         int i = 0;
  66         int length = 0;
  67
  68         if (!cdev)
  69                 return -ENODEV;
  70
  71         if (cdev->private->state == DEV_STATE_NOT_OPER)
  72                 return -ENODEV;
  73
  74         /* what we want to pass to /sbin/hotplug */
  75
  76         envp[i++] = buffer;
  77         length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
  78                            cdev->id.cu_type);
  79         if ((buffer_size - length <= 0) || (i >= num_envp))
  80                 return -ENOMEM;
  81         ++length;
  82         buffer += length;
  83
  84         envp[i++] = buffer;
  85         length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
  86                            cdev->id.cu_model);
  87         if ((buffer_size - length <= 0) || (i >= num_envp))
  88                 return -ENOMEM;
  89         ++length;
  90         buffer += length;
  91
  92         /* The next two can be zero, that's ok for us */
  93         envp[i++] = buffer;
  94         length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
  95                            cdev->id.dev_type);
  96         if ((buffer_size - length <= 0) || (i >= num_envp))
  97                 return -ENOMEM;
  98         ++length;
  99         buffer += length;
 100
 101         envp[i++] = buffer;
 102         length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
 103                            cdev->id.dev_model);
 104         if ((buffer_size - length <= 0) || (i >= num_envp))
 105                 return -ENOMEM;
 106
 107         envp[i] = 0;
 108
 109         return 0;
 110 }
 111
 112 struct bus_type ccw_bus_type = {
 113         .name  = "ccw",
 114         .match = &ccw_bus_match,
 115         .hotplug = &ccw_hotplug,
 116 };
 117
 118 static int io_subchannel_probe (struct device *);
 119 static int io_subchannel_remove (struct device *);
 120 void io_subchannel_irq (struct device *);
 121 static int io_subchannel_notify(struct device *, int);
 122 static void io_subchannel_verify(struct device *);
 123 static void io_subchannel_ioterm(struct device *);
 124 static void io_subchannel_shutdown(struct device *);
 125
 126 struct css_driver io_subchannel_driver = {
 127         .subchannel_type = SUBCHANNEL_TYPE_IO,
 128         .drv = {
 129                 .name = "io_subchannel",
 130                 .bus  = &css_bus_type,
 131                 .probe = &io_subchannel_probe,
 132                 .remove = &io_subchannel_remove,
 133                 .shutdown = &io_subchannel_shutdown,
 134         },
 135         .irq = io_subchannel_irq,
 136         .notify = io_subchannel_notify,
 137         .verify = io_subchannel_verify,
 138         .termination = io_subchannel_ioterm,
 139 };
 140
 141 struct workqueue_struct *ccw_device_work;
 142 struct workqueue_struct *ccw_device_notify_work;
 143 static wait_queue_head_t ccw_device_init_wq;
 144 static atomic_t ccw_device_init_count;
 145
 146 static int __init
 147 init_ccw_bus_type (void)
 148 {
 149         int ret;
 150
 151         init_waitqueue_head(&ccw_device_init_wq);
 152         atomic_set(&ccw_device_init_count, 0);
 153
 154         ccw_device_work = create_singlethread_workqueue("cio");
 155         if (!ccw_device_work)
 156                 return -ENOMEM; /* FIXME: better errno ? */
 157         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 158         if (!ccw_device_notify_work) {
 159                 ret = -ENOMEM; /* FIXME: better errno ? */
 160                 goto out_err;
 161         }
 162         if ((ret = bus_register (&ccw_bus_type)))
 163                 goto out_err;
 164
 165         if ((ret = driver_register(&io_subchannel_driver.drv)))
 166                 goto out_err;
 167
 168         wait_event(ccw_device_init_wq,
 169                    atomic_read(&ccw_device_init_count) == 0);
 170         flush_workqueue(ccw_device_work);
 171         return 0;
 172 out_err:
 173         if (ccw_device_work)
 174                 destroy_workqueue(ccw_device_work);
 175         if (ccw_device_notify_work)
 176                 destroy_workqueue(ccw_device_notify_work);
 177         return ret;
 178 }
 179
 180 static void __exit
 181 cleanup_ccw_bus_type (void)
 182 {
 183         driver_unregister(&io_subchannel_driver.drv);
 184         bus_unregister(&ccw_bus_type);
 185         destroy_workqueue(ccw_device_notify_work);
 186         destroy_workqueue(ccw_device_work);
 187 }
 188
 189 subsys_initcall(init_ccw_bus_type);
 190 module_exit(cleanup_ccw_bus_type);
 191
 192 /************************ device handling **************************/
 193
 194 /*
 195  * A ccw_device has some interfaces in sysfs in addition to the
 196  * standard ones.
 197  * The following entries are designed to export the information which
 198  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 199  * are obvious, so they don't have an entry :)
 200  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 201  */
 202 static ssize_t
 203 chpids_show (struct device * dev, char * buf)
 204 {
 205         struct subchannel *sch = to_subchannel(dev);
 206         struct ssd_info *ssd = &sch->ssd_info;
 207         ssize_t ret = 0;
 208         int chp;
 209
 210         for (chp = 0; chp < 8; chp++)
 211                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 212
 213         ret += sprintf (buf+ret, "\n");
 214         return min((ssize_t)PAGE_SIZE, ret);
 215 }
 216
 217 static ssize_t
 218 pimpampom_show (struct device * dev, char * buf)
 219 {
 220         struct subchannel *sch = to_subchannel(dev);
 221         struct pmcw *pmcw = &sch->schib.pmcw;
 222
 223         return sprintf (buf, "%02x %02x %02x\n",
 224                         pmcw->pim, pmcw->pam, pmcw->pom);
 225 }
 226
 227 static ssize_t
 228 devtype_show (struct device *dev, char *buf)
 229 {
 230         struct ccw_device *cdev = to_ccwdev(dev);
 231         struct ccw_device_id *id = &(cdev->id);
 232
 233         if (id->dev_type != 0)
 234                 return sprintf(buf, "%04x/%02x\n",
 235                                 id->dev_type, id->dev_model);
 236         else
 237                 return sprintf(buf, "n/a\n");
 238 }
 239
 240 static ssize_t
 241 cutype_show (struct device *dev, char *buf)
 242 {
 243         struct ccw_device *cdev = to_ccwdev(dev);
 244         struct ccw_device_id *id = &(cdev->id);
 245
 246         return sprintf(buf, "%04x/%02x\n",
 247                        id->cu_type, id->cu_model);
 248 }
 249
 250 static ssize_t
 251 online_show (struct device *dev, char *buf)
 252 {
 253         struct ccw_device *cdev = to_ccwdev(dev);
 254
 255         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 256 }
 257
 258 static void
 259 ccw_device_remove_disconnected(struct ccw_device *cdev)
 260 {
 261         struct subchannel *sch;
 262         /*
 263          * Forced offline in disconnected state means
 264          * 'throw away device'.
 265          */
 266         sch = to_subchannel(cdev->dev.parent);
 267         device_unregister(&sch->dev);
 268         /* Reset intparm to zeroes. */
 269         sch->schib.pmcw.intparm = 0;
 270         cio_modify(sch);
 271         put_device(&sch->dev);
 272 }
 273
 274 int
 275 ccw_device_set_offline(struct ccw_device *cdev)
 276 {
 277         int ret;
 278
 279         if (!cdev)
 280                 return -ENODEV;
 281         if (!cdev->online || !cdev->drv)
 282                 return -EINVAL;
 283
 284         if (cdev->drv->set_offline) {
 285                 ret = cdev->drv->set_offline(cdev);
 286                 if (ret != 0)
 287                         return ret;
 288         }
 289         cdev->online = 0;
 290         spin_lock_irq(cdev->ccwlock);
 291         ret = ccw_device_offline(cdev);
 292         spin_unlock_irq(cdev->ccwlock);
 293         if (ret == 0)
 294                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 295         else {
 296                 pr_debug("ccw_device_offline returned %d, device %s\n",
 297                          ret, cdev->dev.bus_id);
 298                 cdev->online = 1;
 299         }
 300         return ret;
 301 }
 302
 303 int
 304 ccw_device_set_online(struct ccw_device *cdev)
 305 {
 306         int ret;
 307
 308         if (!cdev)
 309                 return -ENODEV;
 310         if (cdev->online || !cdev->drv)
 311                 return -EINVAL;
 312
 313         spin_lock_irq(cdev->ccwlock);
 314         ret = ccw_device_online(cdev);
 315         spin_unlock_irq(cdev->ccwlock);
 316         if (ret == 0)
 317                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 318         else {
 319                 pr_debug("ccw_device_online returned %d, device %s\n",
 320                          ret, cdev->dev.bus_id);
 321                 return ret;
 322         }
 323         if (cdev->private->state != DEV_STATE_ONLINE)
 324                 return -ENODEV;
 325         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 326                 cdev->online = 1;
 327                 return 0;
 328         }
 329         spin_lock_irq(cdev->ccwlock);
 330         ret = ccw_device_offline(cdev);
 331         spin_unlock_irq(cdev->ccwlock);
 332         if (ret == 0)
 333                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 334         else
 335                 pr_debug("ccw_device_offline returned %d, device %s\n",
 336                          ret, cdev->dev.bus_id);
 337         return (ret = 0) ? -ENODEV : ret;
 338 }
 339
 340 static ssize_t
 341 online_store (struct device *dev, const char *buf, size_t count)
 342 {
 343         struct ccw_device *cdev = to_ccwdev(dev);
 344         int i, force, ret;
 345         char *tmp;
 346
 347         if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
 348                 return -EAGAIN;
 349
 350         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 351                 atomic_set(&cdev->private->onoff, 0);
 352                 return -EINVAL;
 353         }
 354         if (!strncmp(buf, "force\n", count)) {
 355                 force = 1;
 356                 i = 1;
 357         } else {
 358                 force = 0;
 359                 i = simple_strtoul(buf, &tmp, 16);
 360         }
 361         if (i == 1) {
 362                 /* Do device recognition, if needed. */
 363                 if (cdev->id.cu_type == 0) {
 364                         ret = ccw_device_recognition(cdev);
 365                         if (ret) {
 366                                 printk(KERN_WARNING"Couldn't start recognition "
 367                                        "for device %s (ret=%d)\n",
 368                                        cdev->dev.bus_id, ret);
 369                                 goto out;
 370                         }
 371                         wait_event(cdev->private->wait_q,
 372                                    cdev->private->flags.recog_done);
 373                 }
 374                 if (cdev->drv && cdev->drv->set_online)
 375                         ccw_device_set_online(cdev);
 376         } else if (i == 0) {
 377                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 378                         ccw_device_remove_disconnected(cdev);
 379                 else if (cdev->drv && cdev->drv->set_offline)
 380                         ccw_device_set_offline(cdev);
 381         }
 382         if (force && cdev->private->state == DEV_STATE_BOXED) {
 383                 ret = ccw_device_stlck(cdev);
 384                 if (ret) {
 385                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 386                                "returned %d!\n", cdev->dev.bus_id, ret);
 387                         goto out;
 388                 }
 389                 /* Do device recognition, if needed. */
 390                 if (cdev->id.cu_type == 0) {
 391                         cdev->private->state = DEV_STATE_NOT_OPER;
 392                         ret = ccw_device_recognition(cdev);
 393                         if (ret) {
 394                                 printk(KERN_WARNING"Couldn't start recognition "
 395                                        "for device %s (ret=%d)\n",
 396                                        cdev->dev.bus_id, ret);
 397                                 goto out;
 398                         }
 399                         wait_event(cdev->private->wait_q,
 400                                    cdev->private->flags.recog_done);
 401                 }
 402                 if (cdev->drv && cdev->drv->set_online)
 403                         ccw_device_set_online(cdev);
 404         }
 405         out:
 406         if (cdev->drv)
 407                 module_put(cdev->drv->owner);
 408         atomic_set(&cdev->private->onoff, 0);
 409         return count;
 410 }
 411
 412 static ssize_t
 413 available_show (struct device *dev, char *buf)
 414 {
 415         struct ccw_device *cdev = to_ccwdev(dev);
 416         struct subchannel *sch;
 417
 418         switch (cdev->private->state) {
 419         case DEV_STATE_BOXED:
 420                 return sprintf(buf, "boxed\n");
 421         case DEV_STATE_DISCONNECTED:
 422         case DEV_STATE_DISCONNECTED_SENSE_ID:
 423         case DEV_STATE_NOT_OPER:
 424                 sch = to_subchannel(dev->parent);
 425                 if (!sch->lpm)
 426                         return sprintf(buf, "no path\n");
 427                 else
 428                         return sprintf(buf, "no device\n");
 429         default:
 430                 /* All other states considered fine. */
 431                 return sprintf(buf, "good\n");
 432         }
 433 }
 434
 435 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 436 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 437 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 438 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 439 static DEVICE_ATTR(online, 0644, online_show, online_store);
 440 extern struct device_attribute dev_attr_cmb_enable;
 441 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 442
 443 static struct attribute * subch_attrs[] = {
 444         &dev_attr_chpids.attr,
 445         &dev_attr_pimpampom.attr,
 446         NULL,
 447 };
 448
 449 static struct attribute_group subch_attr_group = {
 450         .attrs = subch_attrs,
 451 };
 452
 453 static inline int
 454 subchannel_add_files (struct device *dev)
 455 {
 456         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 457 }
 458
 459 static struct attribute * ccwdev_attrs[] = {
 460         &dev_attr_devtype.attr,
 461         &dev_attr_cutype.attr,
 462         &dev_attr_online.attr,
 463         &dev_attr_cmb_enable.attr,
 464         &dev_attr_availability.attr,
 465         NULL,
 466 };
 467
 468 static struct attribute_group ccwdev_attr_group = {
 469         .attrs = ccwdev_attrs,
 470 };
 471
 472 static inline int
 473 device_add_files (struct device *dev)
 474 {
 475         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 476 }
 477
 478 static inline void
 479 device_remove_files(struct device *dev)
 480 {
 481         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 482 }
 483
 484 /* this is a simple abstraction for device_register that sets the
 485  * correct bus type and adds the bus specific files */
 486 int
 487 ccw_device_register(struct ccw_device *cdev)
 488 {
 489         struct device *dev = &cdev->dev;
 490         int ret;
 491
 492         dev->bus = &ccw_bus_type;
 493
 494         if ((ret = device_add(dev)))
 495                 return ret;
 496
 497         if ((ret = device_add_files(dev)))
 498                 device_del(dev);
 499
 500         return ret;
 501 }
 502
 503 static struct ccw_device *
 504 get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
 505 {
 506         struct ccw_device *cdev;
 507         struct list_head *entry;
 508         struct device *dev;
 509
 510         if (!get_bus(&ccw_bus_type))
 511                 return NULL;
 512         down_read(&ccw_bus_type.subsys.rwsem);
 513         cdev = NULL;
 514         list_for_each(entry, &ccw_bus_type.devices.list) {
 515                 dev = get_device(container_of(entry,
 516                                               struct device, bus_list));
 517                 if (!dev)
 518                         continue;
 519                 cdev = to_ccwdev(dev);
 520                 if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 521                     (cdev->private->devno == devno) &&
 522                     (!strncmp(cdev->dev.bus_id, sibling->dev.bus_id, 4))) {
 523                         cdev->private->state = DEV_STATE_NOT_OPER;
 524                         break;
 525                 }
 526                 put_device(dev);
 527                 cdev = NULL;
 528         }
 529         up_read(&ccw_bus_type.subsys.rwsem);
 530         put_bus(&ccw_bus_type);
 531
 532         return cdev;
 533 }
 534
 535 void
 536 ccw_device_do_unreg_rereg(void *data)
 537 {
 538         struct ccw_device *cdev;
 539         struct subchannel *sch;
 540         int need_rename;
 541
 542         cdev = (struct ccw_device *)data;
 543         sch = to_subchannel(cdev->dev.parent);
 544         if (cdev->private->devno != sch->schib.pmcw.dev) {
 545                 /*
 546                  * The device number has changed. This is usually only when
 547                  * a device has been detached under VM and then re-appeared
 548                  * on another subchannel because of a different attachment
 549                  * order than before. Ideally, we should should just switch
 550                  * subchannels, but unfortunately, this is not possible with
 551                  * the current implementation.
 552                  * Instead, we search for the old subchannel for this device
 553                  * number and deregister so there are no collisions with the
 554                  * newly registered ccw_device.
 555                  * FIXME: Find another solution so the block layer doesn't
 556                  *        get possibly sick...
 557                  */
 558                 struct ccw_device *other_cdev;
 559
 560                 need_rename = 1;
 561                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 562                                                       cdev);
 563                 if (other_cdev) {
 564                         struct subchannel *other_sch;
 565
 566                         other_sch = to_subchannel(other_cdev->dev.parent);
 567                         if (get_device(&other_sch->dev)) {
 568                                 stsch(other_sch->irq, &other_sch->schib);
 569                                 if (other_sch->schib.pmcw.dnv) {
 570                                         other_sch->schib.pmcw.intparm = 0;
 571                                         cio_modify(other_sch);
 572                                 }
 573                                 device_unregister(&other_sch->dev);
 574                         }
 575                 }
 576                 cdev->private->devno = sch->schib.pmcw.dev;
 577         } else
 578                 need_rename = 0;
 579         device_remove_files(&cdev->dev);
 580         device_del(&cdev->dev);
 581         if (need_rename)
 582                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 583                           sch->schib.pmcw.dev);
 584         if (device_add(&cdev->dev)) {
 585                 put_device(&cdev->dev);
 586                 return;
 587         }
 588         if (device_add_files(&cdev->dev))
 589                 device_unregister(&cdev->dev);
 590 }
 591
 592 static void
 593 ccw_device_release(struct device *dev)
 594 {
 595         struct ccw_device *cdev;
 596
 597         cdev = to_ccwdev(dev);
 598         kfree(cdev->private);
 599         kfree(cdev);
 600 }
 601
 602 /*
 603  * Register recognized device.
 604  */
 605 static void
 606 io_subchannel_register(void *data)
 607 {
 608         struct ccw_device *cdev;
 609         struct subchannel *sch;
 610         int ret;
 611
 612         cdev = (struct ccw_device *) data;
 613         sch = to_subchannel(cdev->dev.parent);
 614
 615         if (!list_empty(&sch->dev.children)) {
 616                 bus_rescan_devices(&ccw_bus_type);
 617                 goto out;
 618         }
 619         /* make it known to the system */
 620         ret = ccw_device_register(cdev);
 621         if (ret) {
 622                 printk (KERN_WARNING "%s: could not register %s\n",
 623                         __func__, cdev->dev.bus_id);
 624                 put_device(&cdev->dev);
 625                 sch->dev.driver_data = 0;
 626                 kfree (cdev->private);
 627                 kfree (cdev);
 628                 goto out;
 629         }
 630
 631         ret = subchannel_add_files(cdev->dev.parent);
 632         if (ret)
 633                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 634                        __func__, sch->dev.bus_id);
 635         put_device(&cdev->dev);
 636 out:
 637         cdev->private->flags.recog_done = 1;
 638         put_device(&sch->dev);
 639         wake_up(&cdev->private->wait_q);
 640 }
 641
 642 void
 643 ccw_device_call_sch_unregister(void *data)
 644 {
 645         struct ccw_device *cdev = data;
 646         struct subchannel *sch;
 647
 648         sch = to_subchannel(cdev->dev.parent);
 649         /* Check if device is registered. */
 650         if (!list_empty(&sch->dev.node))
 651                 device_unregister(&sch->dev);
 652         /* Reset intparm to zeroes. */
 653         sch->schib.pmcw.intparm = 0;
 654         cio_modify(sch);
 655         put_device(&cdev->dev);
 656         put_device(&sch->dev);
 657 }
 658
 659 /*
 660  * subchannel recognition done. Called from the state machine.
 661  */
 662 void
 663 io_subchannel_recog_done(struct ccw_device *cdev)
 664 {
 665         struct subchannel *sch;
 666
 667         if (css_init_done == 0) {
 668                 cdev->private->flags.recog_done = 1;
 669                 return;
 670         }
 671         switch (cdev->private->state) {
 672         case DEV_STATE_NOT_OPER:
 673                 cdev->private->flags.recog_done = 1;
 674                 /* Remove device found not operational. */
 675                 if (!get_device(&cdev->dev))
 676                         break;
 677                 sch = to_subchannel(cdev->dev.parent);
 678                 INIT_WORK(&cdev->private->kick_work,
 679                           ccw_device_call_sch_unregister, (void *) cdev);
 680                 queue_work(ccw_device_work, &cdev->private->kick_work);
 681                 break;
 682         case DEV_STATE_BOXED:
 683                 /* Device did not respond in time. */
 684         case DEV_STATE_OFFLINE:
 685                 /*
 686                  * We can't register the device in interrupt context so
 687                  * we schedule a work item.
 688                  */
 689                 if (!get_device(&cdev->dev))
 690                         break;
 691                 INIT_WORK(&cdev->private->kick_work,
 692                           io_subchannel_register, (void *) cdev);
 693                 queue_work(ccw_device_work, &cdev->private->kick_work);
 694                 break;
 695         }
 696         if (atomic_dec_and_test(&ccw_device_init_count))
 697                 wake_up(&ccw_device_init_wq);
 698 }
 699
 700 static int
 701 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 702 {
 703         int rc;
 704
 705         sch->dev.driver_data = cdev;
 706         sch->driver = &io_subchannel_driver;
 707         cdev->ccwlock = &sch->lock;
 708         *cdev->private = (struct ccw_device_private) {
 709                 .devno  = sch->schib.pmcw.dev,
 710                 .irq    = sch->irq,
 711                 .state  = DEV_STATE_NOT_OPER,
 712                 .cmb_list = LIST_HEAD_INIT(cdev->private->cmb_list),
 713         };
 714         init_waitqueue_head(&cdev->private->wait_q);
 715         init_timer(&cdev->private->timer);
 716
 717         /* Set an initial name for the device. */
 718         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 719                   sch->schib.pmcw.dev);
 720
 721         /* Increase counter of devices currently in recognition. */
 722         atomic_inc(&ccw_device_init_count);
 723
 724         /* Start async. device sensing. */
 725         spin_lock_irq(&sch->lock);
 726         rc = ccw_device_recognition(cdev);
 727         spin_unlock_irq(&sch->lock);
 728         if (rc) {
 729                 if (atomic_dec_and_test(&ccw_device_init_count))
 730                         wake_up(&ccw_device_init_wq);
 731         }
 732         return rc;
 733 }
 734
 735 static int
 736 io_subchannel_probe (struct device *pdev)
 737 {
 738         struct subchannel *sch;
 739         struct ccw_device *cdev;
 740         int rc;
 741
 742         sch = to_subchannel(pdev);
 743         if (sch->dev.driver_data) {
 744                 /*
 745                  * This subchannel already has an associated ccw_device.
 746                  * Register it and exit. This happens for all early
 747                  * device, e.g. the console.
 748                  */
 749                 cdev = sch->dev.driver_data;
 750                 device_initialize(&cdev->dev);
 751                 ccw_device_register(cdev);
 752                 subchannel_add_files(&sch->dev);
 753                 /*
 754                  * Check if the device is already online. If it is
 755                  * the reference count needs to be corrected
 756                  * (see ccw_device_online and css_init_done for the
 757                  * ugly details).
 758                  */
 759                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 760                     cdev->private->state != DEV_STATE_OFFLINE &&
 761                     cdev->private->state != DEV_STATE_BOXED)
 762                         get_device(&cdev->dev);
 763                 return 0;
 764         }
 765         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 766         if (!cdev)
 767                 return -ENOMEM;
 768         memset(cdev, 0, sizeof(struct ccw_device));
 769         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 770                                 GFP_KERNEL | GFP_DMA);
 771         if (!cdev->private) {
 772                 kfree(cdev);
 773                 return -ENOMEM;
 774         }
 775         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 776         atomic_set(&cdev->private->onoff, 0);
 777         cdev->dev = (struct device) {
 778                 .parent = pdev,
 779                 .release = ccw_device_release,
 780         };
 781         /* Do first half of device_register. */
 782         device_initialize(&cdev->dev);
 783
 784         if (!get_device(&sch->dev)) {
 785                 if (cdev->dev.release)
 786                         cdev->dev.release(&cdev->dev);
 787                 return -ENODEV;
 788         }
 789
 790         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 791         if (rc) {
 792                 sch->dev.driver_data = 0;
 793                 if (cdev->dev.release)
 794                         cdev->dev.release(&cdev->dev);
 795         }
 796
 797         return rc;
 798 }
 799
 800 static int
 801 io_subchannel_remove (struct device *dev)
 802 {
 803         struct ccw_device *cdev;
 804
 805         if (!dev->driver_data)
 806                 return 0;
 807         cdev = dev->driver_data;
 808         /* Set ccw device to not operational and drop reference. */
 809         cdev->private->state = DEV_STATE_NOT_OPER;
 810         /*
 811          * Careful here. Our ccw device might be yet unregistered when
 812          * de-registering its subchannel (machine check during device
 813          * recognition). Better look if the subchannel has children.
 814          */
 815         if (!list_empty(&dev->children))
 816                 device_unregister(&cdev->dev);
 817         dev->driver_data = NULL;
 818         return 0;
 819 }
 820
 821 static int
 822 io_subchannel_notify(struct device *dev, int event)
 823 {
 824         struct ccw_device *cdev;
 825
 826         cdev = dev->driver_data;
 827         if (!cdev)
 828                 return 0;
 829         if (!cdev->drv)
 830                 return 0;
 831         if (!cdev->online)
 832                 return 0;
 833         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 834 }
 835
 836 static void
 837 io_subchannel_verify(struct device *dev)
 838 {
 839         struct ccw_device *cdev;
 840
 841         cdev = dev->driver_data;
 842         if (cdev)
 843                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 844 }
 845
 846 static void
 847 io_subchannel_ioterm(struct device *dev)
 848 {
 849         struct ccw_device *cdev;
 850
 851         cdev = dev->driver_data;
 852         if (!cdev)
 853                 return;
 854         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 855         if (cdev->handler)
 856                 cdev->handler(cdev, cdev->private->intparm,
 857                               ERR_PTR(-EIO));
 858 }
 859
 860 static void
 861 io_subchannel_shutdown(struct device *dev)
 862 {
 863         struct subchannel *sch;
 864         struct ccw_device *cdev;
 865         int ret;
 866
 867         sch = to_subchannel(dev);
 868         cdev = dev->driver_data;
 869
 870         if (cio_is_console(sch->irq))
 871                 return;
 872         if (!sch->schib.pmcw.ena)
 873                 /* Nothing to do. */
 874                 return;
 875         ret = cio_disable_subchannel(sch);
 876         if (ret != -EBUSY)
 877                 /* Subchannel is disabled, we're done. */
 878                 return;
 879         cdev->private->state = DEV_STATE_QUIESCE;
 880         if (cdev->handler)
 881                 cdev->handler(cdev, cdev->private->intparm,
 882                               ERR_PTR(-EIO));
 883         ret = ccw_device_cancel_halt_clear(cdev);
 884         if (ret == -EBUSY) {
 885                 ccw_device_set_timeout(cdev, HZ/10);
 886                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 887         }
 888         cio_disable_subchannel(sch);
 889 }
 890
 891 #ifdef CONFIG_CCW_CONSOLE
 892 static struct ccw_device console_cdev;
 893 static struct ccw_device_private console_private;
 894 static int console_cdev_in_use;
 895
 896 static int
 897 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 898 {
 899         int rc;
 900
 901         /* Initialize the ccw_device structure. */
 902         cdev->dev = (struct device) {
 903                 .parent = &sch->dev,
 904         };
 905         /* Initialize the subchannel structure */
 906         sch->dev.parent = &css_bus_device;
 907         sch->dev.bus = &css_bus_type;
 908
 909         rc = io_subchannel_recog(cdev, sch);
 910         if (rc)
 911                 return rc;
 912
 913         /* Now wait for the async. recognition to come to an end. */
 914         spin_lock_irq(cdev->ccwlock);
 915         while (!dev_fsm_final_state(cdev))
 916                 wait_cons_dev();
 917         rc = -EIO;
 918         if (cdev->private->state != DEV_STATE_OFFLINE)
 919                 goto out_unlock;
 920         ccw_device_online(cdev);
 921         while (!dev_fsm_final_state(cdev))
 922                 wait_cons_dev();
 923         if (cdev->private->state != DEV_STATE_ONLINE)
 924                 goto out_unlock;
 925         rc = 0;
 926 out_unlock:
 927         spin_unlock_irq(cdev->ccwlock);
 928         return 0;
 929 }
 930
 931 struct ccw_device *
 932 ccw_device_probe_console(void)
 933 {
 934         struct subchannel *sch;
 935         int ret;
 936
 937         if (xchg(&console_cdev_in_use, 1) != 0)
 938                 return NULL;
 939         sch = cio_probe_console();
 940         if (IS_ERR(sch)) {
 941                 console_cdev_in_use = 0;
 942                 return (void *) sch;
 943         }
 944         memset(&console_cdev, 0, sizeof(struct ccw_device));
 945         memset(&console_private, 0, sizeof(struct ccw_device_private));
 946         console_cdev.private = &console_private;
 947         ret = ccw_device_console_enable(&console_cdev, sch);
 948         if (ret) {
 949                 cio_release_console();
 950                 console_cdev_in_use = 0;
 951                 return ERR_PTR(ret);
 952         }
 953         console_cdev.online = 1;
 954         return &console_cdev;
 955 }
 956 #endif
 957
 958 /*
 959  * get ccw_device matching the busid, but only if owned by cdrv
 960  */
 961 struct ccw_device *
 962 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
 963 {
 964         struct device *d, *dev;
 965         struct device_driver *drv;
 966
 967         drv = get_driver(&cdrv->driver);
 968         if (!drv)
 969                 return 0;
 970
 971         down_read(&drv->bus->subsys.rwsem);
 972
 973         dev = NULL;
 974         list_for_each_entry(d, &drv->devices, driver_list) {
 975                 dev = get_device(d);
 976
 977                 if (dev && !strncmp(bus_id, dev->bus_id, BUS_ID_SIZE))
 978                         break;
 979                 else if (dev) {
 980                         put_device(dev);
 981                         dev = NULL;
 982                 }
 983         }
 984         up_read(&drv->bus->subsys.rwsem);
 985         put_driver(drv);
 986
 987         return dev ? to_ccwdev(dev) : 0;
 988 }
 989
 990 /************************** device driver handling ************************/
 991
 992 /* This is the implementation of the ccw_driver class. The probe, remove
 993  * and release methods are initially very similar to the device_driver
 994  * implementations, with the difference that they have ccw_device
 995  * arguments.
 996  *
 997  * A ccw driver also contains the information that is needed for
 998  * device matching.
 999  */
1000 static int
1001 ccw_device_probe (struct device *dev)
1002 {
1003         struct ccw_device *cdev = to_ccwdev(dev);
1004         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1005         int ret;
1006
1007         cdev->drv = cdrv; /* to let the driver call _set_online */
1008
1009         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1010
1011         if (ret) {
1012                 cdev->drv = 0;
1013                 return ret;
1014         }
1015
1016         return 0;
1017 }
1018
1019 static int
1020 ccw_device_remove (struct device *dev)
1021 {
1022         struct ccw_device *cdev = to_ccwdev(dev);
1023         struct ccw_driver *cdrv = cdev->drv;
1024         int ret;
1025
1026         pr_debug("removing device %s\n", cdev->dev.bus_id);
1027         if (cdrv->remove)
1028                 cdrv->remove(cdev);
1029         if (cdev->online) {
1030                 cdev->online = 0;
1031                 spin_lock_irq(cdev->ccwlock);
1032                 ret = ccw_device_offline(cdev);
1033                 spin_unlock_irq(cdev->ccwlock);
1034                 if (ret == 0)
1035                         wait_event(cdev->private->wait_q,
1036                                    dev_fsm_final_state(cdev));
1037                 else
1038                         //FIXME: we can't fail!
1039                         pr_debug("ccw_device_offline returned %d, device %s\n",
1040                                  ret, cdev->dev.bus_id);
1041         }
1042         ccw_device_set_timeout(cdev, 0);
1043         cdev->drv = 0;
1044         return 0;
1045 }
1046
1047 int
1048 ccw_driver_register (struct ccw_driver *cdriver)
1049 {
1050         struct device_driver *drv = &cdriver->driver;
1051
1052         drv->bus = &ccw_bus_type;
1053         drv->name = cdriver->name;
1054         drv->probe = ccw_device_probe;
1055         drv->remove = ccw_device_remove;
1056
1057         return driver_register(drv);
1058 }
1059
1060 void
1061 ccw_driver_unregister (struct ccw_driver *cdriver)
1062 {
1063         driver_unregister(&cdriver->driver);
1064 }
1065
1066 MODULE_LICENSE("GPL");
1067 EXPORT_SYMBOL(ccw_device_set_online);
1068 EXPORT_SYMBOL(ccw_device_set_offline);
1069 EXPORT_SYMBOL(ccw_driver_register);
1070 EXPORT_SYMBOL(ccw_driver_unregister);
1071 EXPORT_SYMBOL(get_ccwdev_by_busid);
1072 EXPORT_SYMBOL(ccw_bus_type);
1073 EXPORT_SYMBOL(ccw_device_work);
1074 EXPORT_SYMBOL(ccw_device_notify_work);