drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.120 $
   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         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 163         if (!slow_path_wq) {
 164                 ret = -ENOMEM; /* FIXME: better errno ? */
 165                 goto out_err;
 166         }
 167         if ((ret = bus_register (&ccw_bus_type)))
 168                 goto out_err;
 169
 170         if ((ret = driver_register(&io_subchannel_driver.drv)))
 171                 goto out_err;
 172
 173         wait_event(ccw_device_init_wq,
 174                    atomic_read(&ccw_device_init_count) == 0);
 175         flush_workqueue(ccw_device_work);
 176         return 0;
 177 out_err:
 178         if (ccw_device_work)
 179                 destroy_workqueue(ccw_device_work);
 180         if (ccw_device_notify_work)
 181                 destroy_workqueue(ccw_device_notify_work);
 182         if (slow_path_wq)
 183                 destroy_workqueue(slow_path_wq);
 184         return ret;
 185 }
 186
 187 static void __exit
 188 cleanup_ccw_bus_type (void)
 189 {
 190         driver_unregister(&io_subchannel_driver.drv);
 191         bus_unregister(&ccw_bus_type);
 192         destroy_workqueue(ccw_device_notify_work);
 193         destroy_workqueue(ccw_device_work);
 194 }
 195
 196 subsys_initcall(init_ccw_bus_type);
 197 module_exit(cleanup_ccw_bus_type);
 198
 199 /************************ device handling **************************/
 200
 201 /*
 202  * A ccw_device has some interfaces in sysfs in addition to the
 203  * standard ones.
 204  * The following entries are designed to export the information which
 205  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 206  * are obvious, so they don't have an entry :)
 207  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 208  */
 209 static ssize_t
 210 chpids_show (struct device * dev, char * buf)
 211 {
 212         struct subchannel *sch = to_subchannel(dev);
 213         struct ssd_info *ssd = &sch->ssd_info;
 214         ssize_t ret = 0;
 215         int chp;
 216
 217         for (chp = 0; chp < 8; chp++)
 218                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 219
 220         ret += sprintf (buf+ret, "\n");
 221         return min((ssize_t)PAGE_SIZE, ret);
 222 }
 223
 224 static ssize_t
 225 pimpampom_show (struct device * dev, char * buf)
 226 {
 227         struct subchannel *sch = to_subchannel(dev);
 228         struct pmcw *pmcw = &sch->schib.pmcw;
 229
 230         return sprintf (buf, "%02x %02x %02x\n",
 231                         pmcw->pim, pmcw->pam, pmcw->pom);
 232 }
 233
 234 static ssize_t
 235 devtype_show (struct device *dev, char *buf)
 236 {
 237         struct ccw_device *cdev = to_ccwdev(dev);
 238         struct ccw_device_id *id = &(cdev->id);
 239
 240         if (id->dev_type != 0)
 241                 return sprintf(buf, "%04x/%02x\n",
 242                                 id->dev_type, id->dev_model);
 243         else
 244                 return sprintf(buf, "n/a\n");
 245 }
 246
 247 static ssize_t
 248 cutype_show (struct device *dev, char *buf)
 249 {
 250         struct ccw_device *cdev = to_ccwdev(dev);
 251         struct ccw_device_id *id = &(cdev->id);
 252
 253         return sprintf(buf, "%04x/%02x\n",
 254                        id->cu_type, id->cu_model);
 255 }
 256
 257 static ssize_t
 258 online_show (struct device *dev, char *buf)
 259 {
 260         struct ccw_device *cdev = to_ccwdev(dev);
 261
 262         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 263 }
 264
 265 static void
 266 ccw_device_remove_disconnected(struct ccw_device *cdev)
 267 {
 268         struct subchannel *sch;
 269         /*
 270          * Forced offline in disconnected state means
 271          * 'throw away device'.
 272          */
 273         sch = to_subchannel(cdev->dev.parent);
 274         device_unregister(&sch->dev);
 275         /* Reset intparm to zeroes. */
 276         sch->schib.pmcw.intparm = 0;
 277         cio_modify(sch);
 278         put_device(&sch->dev);
 279 }
 280
 281 int
 282 ccw_device_set_offline(struct ccw_device *cdev)
 283 {
 284         int ret;
 285
 286         if (!cdev)
 287                 return -ENODEV;
 288         if (!cdev->online || !cdev->drv)
 289                 return -EINVAL;
 290
 291         if (cdev->drv->set_offline) {
 292                 ret = cdev->drv->set_offline(cdev);
 293                 if (ret != 0)
 294                         return ret;
 295         }
 296         cdev->online = 0;
 297         spin_lock_irq(cdev->ccwlock);
 298         ret = ccw_device_offline(cdev);
 299         spin_unlock_irq(cdev->ccwlock);
 300         if (ret == 0)
 301                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 302         else {
 303                 pr_debug("ccw_device_offline returned %d, device %s\n",
 304                          ret, cdev->dev.bus_id);
 305                 cdev->online = 1;
 306         }
 307         return ret;
 308 }
 309
 310 int
 311 ccw_device_set_online(struct ccw_device *cdev)
 312 {
 313         int ret;
 314
 315         if (!cdev)
 316                 return -ENODEV;
 317         if (cdev->online || !cdev->drv)
 318                 return -EINVAL;
 319
 320         spin_lock_irq(cdev->ccwlock);
 321         ret = ccw_device_online(cdev);
 322         spin_unlock_irq(cdev->ccwlock);
 323         if (ret == 0)
 324                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 325         else {
 326                 pr_debug("ccw_device_online returned %d, device %s\n",
 327                          ret, cdev->dev.bus_id);
 328                 return ret;
 329         }
 330         if (cdev->private->state != DEV_STATE_ONLINE)
 331                 return -ENODEV;
 332         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 333                 cdev->online = 1;
 334                 return 0;
 335         }
 336         spin_lock_irq(cdev->ccwlock);
 337         ret = ccw_device_offline(cdev);
 338         spin_unlock_irq(cdev->ccwlock);
 339         if (ret == 0)
 340                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 341         else
 342                 pr_debug("ccw_device_offline returned %d, device %s\n",
 343                          ret, cdev->dev.bus_id);
 344         return (ret = 0) ? -ENODEV : ret;
 345 }
 346
 347 static ssize_t
 348 online_store (struct device *dev, const char *buf, size_t count)
 349 {
 350         struct ccw_device *cdev = to_ccwdev(dev);
 351         int i, force, ret;
 352         char *tmp;
 353
 354         if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
 355                 return -EAGAIN;
 356
 357         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 358                 atomic_set(&cdev->private->onoff, 0);
 359                 return -EINVAL;
 360         }
 361         if (!strncmp(buf, "force\n", count)) {
 362                 force = 1;
 363                 i = 1;
 364         } else {
 365                 force = 0;
 366                 i = simple_strtoul(buf, &tmp, 16);
 367         }
 368         if (i == 1) {
 369                 /* Do device recognition, if needed. */
 370                 if (cdev->id.cu_type == 0) {
 371                         ret = ccw_device_recognition(cdev);
 372                         if (ret) {
 373                                 printk(KERN_WARNING"Couldn't start recognition "
 374                                        "for device %s (ret=%d)\n",
 375                                        cdev->dev.bus_id, ret);
 376                                 goto out;
 377                         }
 378                         wait_event(cdev->private->wait_q,
 379                                    cdev->private->flags.recog_done);
 380                 }
 381                 if (cdev->drv && cdev->drv->set_online)
 382                         ccw_device_set_online(cdev);
 383         } else if (i == 0) {
 384                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 385                         ccw_device_remove_disconnected(cdev);
 386                 else if (cdev->drv && cdev->drv->set_offline)
 387                         ccw_device_set_offline(cdev);
 388         }
 389         if (force && cdev->private->state == DEV_STATE_BOXED) {
 390                 ret = ccw_device_stlck(cdev);
 391                 if (ret) {
 392                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 393                                "returned %d!\n", cdev->dev.bus_id, ret);
 394                         goto out;
 395                 }
 396                 /* Do device recognition, if needed. */
 397                 if (cdev->id.cu_type == 0) {
 398                         cdev->private->state = DEV_STATE_NOT_OPER;
 399                         ret = ccw_device_recognition(cdev);
 400                         if (ret) {
 401                                 printk(KERN_WARNING"Couldn't start recognition "
 402                                        "for device %s (ret=%d)\n",
 403                                        cdev->dev.bus_id, ret);
 404                                 goto out;
 405                         }
 406                         wait_event(cdev->private->wait_q,
 407                                    cdev->private->flags.recog_done);
 408                 }
 409                 if (cdev->drv && cdev->drv->set_online)
 410                         ccw_device_set_online(cdev);
 411         }
 412         out:
 413         if (cdev->drv)
 414                 module_put(cdev->drv->owner);
 415         atomic_set(&cdev->private->onoff, 0);
 416         return count;
 417 }
 418
 419 static ssize_t
 420 available_show (struct device *dev, char *buf)
 421 {
 422         struct ccw_device *cdev = to_ccwdev(dev);
 423         struct subchannel *sch;
 424
 425         switch (cdev->private->state) {
 426         case DEV_STATE_BOXED:
 427                 return sprintf(buf, "boxed\n");
 428         case DEV_STATE_DISCONNECTED:
 429         case DEV_STATE_DISCONNECTED_SENSE_ID:
 430         case DEV_STATE_NOT_OPER:
 431                 sch = to_subchannel(dev->parent);
 432                 if (!sch->lpm)
 433                         return sprintf(buf, "no path\n");
 434                 else
 435                         return sprintf(buf, "no device\n");
 436         default:
 437                 /* All other states considered fine. */
 438                 return sprintf(buf, "good\n");
 439         }
 440 }
 441
 442 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 443 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 444 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 445 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 446 static DEVICE_ATTR(online, 0644, online_show, online_store);
 447 extern struct device_attribute dev_attr_cmb_enable;
 448 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 449
 450 static struct attribute * subch_attrs[] = {
 451         &dev_attr_chpids.attr,
 452         &dev_attr_pimpampom.attr,
 453         NULL,
 454 };
 455
 456 static struct attribute_group subch_attr_group = {
 457         .attrs = subch_attrs,
 458 };
 459
 460 static inline int
 461 subchannel_add_files (struct device *dev)
 462 {
 463         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 464 }
 465
 466 static struct attribute * ccwdev_attrs[] = {
 467         &dev_attr_devtype.attr,
 468         &dev_attr_cutype.attr,
 469         &dev_attr_online.attr,
 470         &dev_attr_cmb_enable.attr,
 471         &dev_attr_availability.attr,
 472         NULL,
 473 };
 474
 475 static struct attribute_group ccwdev_attr_group = {
 476         .attrs = ccwdev_attrs,
 477 };
 478
 479 static inline int
 480 device_add_files (struct device *dev)
 481 {
 482         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 483 }
 484
 485 static inline void
 486 device_remove_files(struct device *dev)
 487 {
 488         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 489 }
 490
 491 /* this is a simple abstraction for device_register that sets the
 492  * correct bus type and adds the bus specific files */
 493 int
 494 ccw_device_register(struct ccw_device *cdev)
 495 {
 496         struct device *dev = &cdev->dev;
 497         int ret;
 498
 499         dev->bus = &ccw_bus_type;
 500
 501         if ((ret = device_add(dev)))
 502                 return ret;
 503
 504         if ((ret = device_add_files(dev)))
 505                 device_del(dev);
 506
 507         return ret;
 508 }
 509
 510 static struct ccw_device *
 511 get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
 512 {
 513         struct ccw_device *cdev;
 514         struct list_head *entry;
 515         struct device *dev;
 516
 517         if (!get_bus(&ccw_bus_type))
 518                 return NULL;
 519         down_read(&ccw_bus_type.subsys.rwsem);
 520         cdev = NULL;
 521         list_for_each(entry, &ccw_bus_type.devices.list) {
 522                 dev = get_device(container_of(entry,
 523                                               struct device, bus_list));
 524                 if (!dev)
 525                         continue;
 526                 cdev = to_ccwdev(dev);
 527                 if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 528                     (cdev->private->devno == devno) &&
 529                     (!strncmp(cdev->dev.bus_id, sibling->dev.bus_id,
 530                               BUS_ID_SIZE))) {
 531                         cdev->private->state = DEV_STATE_NOT_OPER;
 532                         break;
 533                 }
 534                 put_device(dev);
 535                 cdev = NULL;
 536         }
 537         up_read(&ccw_bus_type.subsys.rwsem);
 538         put_bus(&ccw_bus_type);
 539
 540         return cdev;
 541 }
 542
 543 void
 544 ccw_device_do_unreg_rereg(void *data)
 545 {
 546         struct ccw_device *cdev;
 547         struct subchannel *sch;
 548         int need_rename;
 549
 550         cdev = (struct ccw_device *)data;
 551         sch = to_subchannel(cdev->dev.parent);
 552         if (cdev->private->devno != sch->schib.pmcw.dev) {
 553                 /*
 554                  * The device number has changed. This is usually only when
 555                  * a device has been detached under VM and then re-appeared
 556                  * on another subchannel because of a different attachment
 557                  * order than before. Ideally, we should should just switch
 558                  * subchannels, but unfortunately, this is not possible with
 559                  * the current implementation.
 560                  * Instead, we search for the old subchannel for this device
 561                  * number and deregister so there are no collisions with the
 562                  * newly registered ccw_device.
 563                  * FIXME: Find another solution so the block layer doesn't
 564                  *        get possibly sick...
 565                  */
 566                 struct ccw_device *other_cdev;
 567
 568                 need_rename = 1;
 569                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 570                                                       cdev);
 571                 if (other_cdev) {
 572                         struct subchannel *other_sch;
 573
 574                         other_sch = to_subchannel(other_cdev->dev.parent);
 575                         if (get_device(&other_sch->dev)) {
 576                                 stsch(other_sch->irq, &other_sch->schib);
 577                                 if (other_sch->schib.pmcw.dnv) {
 578                                         other_sch->schib.pmcw.intparm = 0;
 579                                         cio_modify(other_sch);
 580                                 }
 581                                 device_unregister(&other_sch->dev);
 582                         }
 583                 }
 584                 cdev->private->devno = sch->schib.pmcw.dev;
 585         } else
 586                 need_rename = 0;
 587         device_remove_files(&cdev->dev);
 588         device_del(&cdev->dev);
 589         if (need_rename)
 590                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 591                           sch->schib.pmcw.dev);
 592         if (device_add(&cdev->dev)) {
 593                 put_device(&cdev->dev);
 594                 return;
 595         }
 596         if (device_add_files(&cdev->dev))
 597                 device_unregister(&cdev->dev);
 598 }
 599
 600 static void
 601 ccw_device_release(struct device *dev)
 602 {
 603         struct ccw_device *cdev;
 604
 605         cdev = to_ccwdev(dev);
 606         kfree(cdev->private);
 607         kfree(cdev);
 608 }
 609
 610 /*
 611  * Register recognized device.
 612  */
 613 static void
 614 io_subchannel_register(void *data)
 615 {
 616         struct ccw_device *cdev;
 617         struct subchannel *sch;
 618         int ret;
 619
 620         cdev = (struct ccw_device *) data;
 621         sch = to_subchannel(cdev->dev.parent);
 622
 623         if (!list_empty(&sch->dev.children)) {
 624                 bus_rescan_devices(&ccw_bus_type);
 625                 goto out;
 626         }
 627         /* make it known to the system */
 628         ret = ccw_device_register(cdev);
 629         if (ret) {
 630                 printk (KERN_WARNING "%s: could not register %s\n",
 631                         __func__, cdev->dev.bus_id);
 632                 put_device(&cdev->dev);
 633                 sch->dev.driver_data = 0;
 634                 kfree (cdev->private);
 635                 kfree (cdev);
 636                 goto out;
 637         }
 638
 639         ret = subchannel_add_files(cdev->dev.parent);
 640         if (ret)
 641                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 642                        __func__, sch->dev.bus_id);
 643         put_device(&cdev->dev);
 644 out:
 645         cdev->private->flags.recog_done = 1;
 646         put_device(&sch->dev);
 647         wake_up(&cdev->private->wait_q);
 648 }
 649
 650 void
 651 ccw_device_call_sch_unregister(void *data)
 652 {
 653         struct ccw_device *cdev = data;
 654         struct subchannel *sch;
 655
 656         sch = to_subchannel(cdev->dev.parent);
 657         device_unregister(&sch->dev);
 658         /* Reset intparm to zeroes. */
 659         sch->schib.pmcw.intparm = 0;
 660         cio_modify(sch);
 661         put_device(&cdev->dev);
 662         put_device(&sch->dev);
 663 }
 664
 665 /*
 666  * subchannel recognition done. Called from the state machine.
 667  */
 668 void
 669 io_subchannel_recog_done(struct ccw_device *cdev)
 670 {
 671         struct subchannel *sch;
 672
 673         if (css_init_done == 0) {
 674                 cdev->private->flags.recog_done = 1;
 675                 return;
 676         }
 677         switch (cdev->private->state) {
 678         case DEV_STATE_NOT_OPER:
 679                 cdev->private->flags.recog_done = 1;
 680                 /* Remove device found not operational. */
 681                 if (!get_device(&cdev->dev))
 682                         break;
 683                 sch = to_subchannel(cdev->dev.parent);
 684                 INIT_WORK(&cdev->private->kick_work,
 685                           ccw_device_call_sch_unregister, (void *) cdev);
 686                 queue_work(slow_path_wq, &cdev->private->kick_work);
 687                 break;
 688         case DEV_STATE_BOXED:
 689                 /* Device did not respond in time. */
 690         case DEV_STATE_OFFLINE:
 691                 /*
 692                  * We can't register the device in interrupt context so
 693                  * we schedule a work item.
 694                  */
 695                 if (!get_device(&cdev->dev))
 696                         break;
 697                 INIT_WORK(&cdev->private->kick_work,
 698                           io_subchannel_register, (void *) cdev);
 699                 queue_work(ccw_device_work, &cdev->private->kick_work);
 700                 break;
 701         }
 702         if (atomic_dec_and_test(&ccw_device_init_count))
 703                 wake_up(&ccw_device_init_wq);
 704 }
 705
 706 static int
 707 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 708 {
 709         int rc;
 710
 711         sch->dev.driver_data = cdev;
 712         sch->driver = &io_subchannel_driver;
 713         cdev->ccwlock = &sch->lock;
 714         *cdev->private = (struct ccw_device_private) {
 715                 .devno  = sch->schib.pmcw.dev,
 716                 .irq    = sch->irq,
 717                 .state  = DEV_STATE_NOT_OPER,
 718                 .cmb_list = LIST_HEAD_INIT(cdev->private->cmb_list),
 719         };
 720         init_waitqueue_head(&cdev->private->wait_q);
 721         init_timer(&cdev->private->timer);
 722
 723         /* Set an initial name for the device. */
 724         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 725                   sch->schib.pmcw.dev);
 726
 727         /* Increase counter of devices currently in recognition. */
 728         atomic_inc(&ccw_device_init_count);
 729
 730         /* Start async. device sensing. */
 731         spin_lock_irq(&sch->lock);
 732         rc = ccw_device_recognition(cdev);
 733         spin_unlock_irq(&sch->lock);
 734         if (rc) {
 735                 if (atomic_dec_and_test(&ccw_device_init_count))
 736                         wake_up(&ccw_device_init_wq);
 737         }
 738         return rc;
 739 }
 740
 741 static int
 742 io_subchannel_probe (struct device *pdev)
 743 {
 744         struct subchannel *sch;
 745         struct ccw_device *cdev;
 746         int rc;
 747
 748         sch = to_subchannel(pdev);
 749         if (sch->dev.driver_data) {
 750                 /*
 751                  * This subchannel already has an associated ccw_device.
 752                  * Register it and exit. This happens for all early
 753                  * device, e.g. the console.
 754                  */
 755                 cdev = sch->dev.driver_data;
 756                 device_initialize(&cdev->dev);
 757                 ccw_device_register(cdev);
 758                 subchannel_add_files(&sch->dev);
 759                 /*
 760                  * Check if the device is already online. If it is
 761                  * the reference count needs to be corrected
 762                  * (see ccw_device_online and css_init_done for the
 763                  * ugly details).
 764                  */
 765                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 766                     cdev->private->state != DEV_STATE_OFFLINE &&
 767                     cdev->private->state != DEV_STATE_BOXED)
 768                         get_device(&cdev->dev);
 769                 return 0;
 770         }
 771         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 772         if (!cdev)
 773                 return -ENOMEM;
 774         memset(cdev, 0, sizeof(struct ccw_device));
 775         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 776                                 GFP_KERNEL | GFP_DMA);
 777         if (!cdev->private) {
 778                 kfree(cdev);
 779                 return -ENOMEM;
 780         }
 781         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 782         atomic_set(&cdev->private->onoff, 0);
 783         cdev->dev = (struct device) {
 784                 .parent = pdev,
 785                 .release = ccw_device_release,
 786         };
 787         /* Do first half of device_register. */
 788         device_initialize(&cdev->dev);
 789
 790         if (!get_device(&sch->dev)) {
 791                 if (cdev->dev.release)
 792                         cdev->dev.release(&cdev->dev);
 793                 return -ENODEV;
 794         }
 795
 796         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 797         if (rc) {
 798                 sch->dev.driver_data = 0;
 799                 if (cdev->dev.release)
 800                         cdev->dev.release(&cdev->dev);
 801         }
 802
 803         return rc;
 804 }
 805
 806 static int
 807 io_subchannel_remove (struct device *dev)
 808 {
 809         struct ccw_device *cdev;
 810
 811         if (!dev->driver_data)
 812                 return 0;
 813         cdev = dev->driver_data;
 814         /* Set ccw device to not operational and drop reference. */
 815         cdev->private->state = DEV_STATE_NOT_OPER;
 816         /*
 817          * Careful here. Our ccw device might be yet unregistered when
 818          * de-registering its subchannel (machine check during device
 819          * recognition). Better look if the subchannel has children.
 820          */
 821         if (!list_empty(&dev->children))
 822                 device_unregister(&cdev->dev);
 823         dev->driver_data = NULL;
 824         return 0;
 825 }
 826
 827 static int
 828 io_subchannel_notify(struct device *dev, int event)
 829 {
 830         struct ccw_device *cdev;
 831
 832         cdev = dev->driver_data;
 833         if (!cdev)
 834                 return 0;
 835         if (!cdev->drv)
 836                 return 0;
 837         if (!cdev->online)
 838                 return 0;
 839         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 840 }
 841
 842 static void
 843 io_subchannel_verify(struct device *dev)
 844 {
 845         struct ccw_device *cdev;
 846
 847         cdev = dev->driver_data;
 848         if (cdev)
 849                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 850 }
 851
 852 static void
 853 io_subchannel_ioterm(struct device *dev)
 854 {
 855         struct ccw_device *cdev;
 856
 857         cdev = dev->driver_data;
 858         if (!cdev)
 859                 return;
 860         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 861         if (cdev->handler)
 862                 cdev->handler(cdev, cdev->private->intparm,
 863                               ERR_PTR(-EIO));
 864 }
 865
 866 static void
 867 io_subchannel_shutdown(struct device *dev)
 868 {
 869         struct subchannel *sch;
 870         struct ccw_device *cdev;
 871         int ret;
 872
 873         sch = to_subchannel(dev);
 874         cdev = dev->driver_data;
 875
 876         if (cio_is_console(sch->irq))
 877                 return;
 878         if (!sch->schib.pmcw.ena)
 879                 /* Nothing to do. */
 880                 return;
 881         ret = cio_disable_subchannel(sch);
 882         if (ret != -EBUSY)
 883                 /* Subchannel is disabled, we're done. */
 884                 return;
 885         cdev->private->state = DEV_STATE_QUIESCE;
 886         if (cdev->handler)
 887                 cdev->handler(cdev, cdev->private->intparm,
 888                               ERR_PTR(-EIO));
 889         ret = ccw_device_cancel_halt_clear(cdev);
 890         if (ret == -EBUSY) {
 891                 ccw_device_set_timeout(cdev, HZ/10);
 892                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 893         }
 894         cio_disable_subchannel(sch);
 895 }
 896
 897 #ifdef CONFIG_CCW_CONSOLE
 898 static struct ccw_device console_cdev;
 899 static struct ccw_device_private console_private;
 900 static int console_cdev_in_use;
 901
 902 static int
 903 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 904 {
 905         int rc;
 906
 907         /* Initialize the ccw_device structure. */
 908         cdev->dev = (struct device) {
 909                 .parent = &sch->dev,
 910         };
 911         /* Initialize the subchannel structure */
 912         sch->dev.parent = &css_bus_device;
 913         sch->dev.bus = &css_bus_type;
 914
 915         rc = io_subchannel_recog(cdev, sch);
 916         if (rc)
 917                 return rc;
 918
 919         /* Now wait for the async. recognition to come to an end. */
 920         spin_lock_irq(cdev->ccwlock);
 921         while (!dev_fsm_final_state(cdev))
 922                 wait_cons_dev();
 923         rc = -EIO;
 924         if (cdev->private->state != DEV_STATE_OFFLINE)
 925                 goto out_unlock;
 926         ccw_device_online(cdev);
 927         while (!dev_fsm_final_state(cdev))
 928                 wait_cons_dev();
 929         if (cdev->private->state != DEV_STATE_ONLINE)
 930                 goto out_unlock;
 931         rc = 0;
 932 out_unlock:
 933         spin_unlock_irq(cdev->ccwlock);
 934         return 0;
 935 }
 936
 937 struct ccw_device *
 938 ccw_device_probe_console(void)
 939 {
 940         struct subchannel *sch;
 941         int ret;
 942
 943         if (xchg(&console_cdev_in_use, 1) != 0)
 944                 return NULL;
 945         sch = cio_probe_console();
 946         if (IS_ERR(sch)) {
 947                 console_cdev_in_use = 0;
 948                 return (void *) sch;
 949         }
 950         memset(&console_cdev, 0, sizeof(struct ccw_device));
 951         memset(&console_private, 0, sizeof(struct ccw_device_private));
 952         console_cdev.private = &console_private;
 953         ret = ccw_device_console_enable(&console_cdev, sch);
 954         if (ret) {
 955                 cio_release_console();
 956                 console_cdev_in_use = 0;
 957                 return ERR_PTR(ret);
 958         }
 959         console_cdev.online = 1;
 960         return &console_cdev;
 961 }
 962 #endif
 963
 964 /*
 965  * get ccw_device matching the busid, but only if owned by cdrv
 966  */
 967 struct ccw_device *
 968 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
 969 {
 970         struct device *d, *dev;
 971         struct device_driver *drv;
 972
 973         drv = get_driver(&cdrv->driver);
 974         if (!drv)
 975                 return 0;
 976
 977         down_read(&drv->bus->subsys.rwsem);
 978
 979         dev = NULL;
 980         list_for_each_entry(d, &drv->devices, driver_list) {
 981                 dev = get_device(d);
 982
 983                 if (dev && !strncmp(bus_id, dev->bus_id, BUS_ID_SIZE))
 984                         break;
 985                 else if (dev) {
 986                         put_device(dev);
 987                         dev = NULL;
 988                 }
 989         }
 990         up_read(&drv->bus->subsys.rwsem);
 991         put_driver(drv);
 992
 993         return dev ? to_ccwdev(dev) : 0;
 994 }
 995
 996 /************************** device driver handling ************************/
 997
 998 /* This is the implementation of the ccw_driver class. The probe, remove
 999  * and release methods are initially very similar to the device_driver
1000  * implementations, with the difference that they have ccw_device
1001  * arguments.
1002  *
1003  * A ccw driver also contains the information that is needed for
1004  * device matching.
1005  */
1006 static int
1007 ccw_device_probe (struct device *dev)
1008 {
1009         struct ccw_device *cdev = to_ccwdev(dev);
1010         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1011         int ret;
1012
1013         cdev->drv = cdrv; /* to let the driver call _set_online */
1014
1015         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1016
1017         if (ret) {
1018                 cdev->drv = 0;
1019                 return ret;
1020         }
1021
1022         return 0;
1023 }
1024
1025 static int
1026 ccw_device_remove (struct device *dev)
1027 {
1028         struct ccw_device *cdev = to_ccwdev(dev);
1029         struct ccw_driver *cdrv = cdev->drv;
1030         int ret;
1031
1032         pr_debug("removing device %s\n", cdev->dev.bus_id);
1033         if (cdrv->remove)
1034                 cdrv->remove(cdev);
1035         if (cdev->online) {
1036                 cdev->online = 0;
1037                 spin_lock_irq(cdev->ccwlock);
1038                 ret = ccw_device_offline(cdev);
1039                 spin_unlock_irq(cdev->ccwlock);
1040                 if (ret == 0)
1041                         wait_event(cdev->private->wait_q,
1042                                    dev_fsm_final_state(cdev));
1043                 else
1044                         //FIXME: we can't fail!
1045                         pr_debug("ccw_device_offline returned %d, device %s\n",
1046                                  ret, cdev->dev.bus_id);
1047         }
1048         ccw_device_set_timeout(cdev, 0);
1049         cdev->drv = 0;
1050         return 0;
1051 }
1052
1053 int
1054 ccw_driver_register (struct ccw_driver *cdriver)
1055 {
1056         struct device_driver *drv = &cdriver->driver;
1057
1058         drv->bus = &ccw_bus_type;
1059         drv->name = cdriver->name;
1060         drv->probe = ccw_device_probe;
1061         drv->remove = ccw_device_remove;
1062
1063         return driver_register(drv);
1064 }
1065
1066 void
1067 ccw_driver_unregister (struct ccw_driver *cdriver)
1068 {
1069         driver_unregister(&cdriver->driver);
1070 }
1071
1072 MODULE_LICENSE("GPL");
1073 EXPORT_SYMBOL(ccw_device_set_online);
1074 EXPORT_SYMBOL(ccw_device_set_offline);
1075 EXPORT_SYMBOL(ccw_driver_register);
1076 EXPORT_SYMBOL(ccw_driver_unregister);
1077 EXPORT_SYMBOL(get_ccwdev_by_busid);
1078 EXPORT_SYMBOL(ccw_bus_type);
1079 EXPORT_SYMBOL(ccw_device_work);
1080 EXPORT_SYMBOL(ccw_device_notify_work);