drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.124 $
   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 extern int css_get_ssd_info(struct subchannel *sch);
 544
 545 void
 546 ccw_device_do_unreg_rereg(void *data)
 547 {
 548         struct ccw_device *cdev;
 549         struct subchannel *sch;
 550         int need_rename;
 551
 552         cdev = (struct ccw_device *)data;
 553         sch = to_subchannel(cdev->dev.parent);
 554         if (cdev->private->devno != sch->schib.pmcw.dev) {
 555                 /*
 556                  * The device number has changed. This is usually only when
 557                  * a device has been detached under VM and then re-appeared
 558                  * on another subchannel because of a different attachment
 559                  * order than before. Ideally, we should should just switch
 560                  * subchannels, but unfortunately, this is not possible with
 561                  * the current implementation.
 562                  * Instead, we search for the old subchannel for this device
 563                  * number and deregister so there are no collisions with the
 564                  * newly registered ccw_device.
 565                  * FIXME: Find another solution so the block layer doesn't
 566                  *        get possibly sick...
 567                  */
 568                 struct ccw_device *other_cdev;
 569
 570                 need_rename = 1;
 571                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 572                                                       cdev);
 573                 if (other_cdev) {
 574                         struct subchannel *other_sch;
 575
 576                         other_sch = to_subchannel(other_cdev->dev.parent);
 577                         if (get_device(&other_sch->dev)) {
 578                                 stsch(other_sch->irq, &other_sch->schib);
 579                                 if (other_sch->schib.pmcw.dnv) {
 580                                         other_sch->schib.pmcw.intparm = 0;
 581                                         cio_modify(other_sch);
 582                                 }
 583                                 device_unregister(&other_sch->dev);
 584                         }
 585                 }
 586                 /* Update ssd info here. */
 587                 css_get_ssd_info(sch);
 588                 cdev->private->devno = sch->schib.pmcw.dev;
 589         } else
 590                 need_rename = 0;
 591         device_remove_files(&cdev->dev);
 592         device_del(&cdev->dev);
 593         if (need_rename)
 594                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 595                           sch->schib.pmcw.dev);
 596         if (device_add(&cdev->dev)) {
 597                 put_device(&cdev->dev);
 598                 return;
 599         }
 600         if (device_add_files(&cdev->dev))
 601                 device_unregister(&cdev->dev);
 602 }
 603
 604 static void
 605 ccw_device_release(struct device *dev)
 606 {
 607         struct ccw_device *cdev;
 608
 609         cdev = to_ccwdev(dev);
 610         kfree(cdev->private);
 611         kfree(cdev);
 612 }
 613
 614 /*
 615  * Register recognized device.
 616  */
 617 static void
 618 io_subchannel_register(void *data)
 619 {
 620         struct ccw_device *cdev;
 621         struct subchannel *sch;
 622         int ret;
 623
 624         cdev = (struct ccw_device *) data;
 625         sch = to_subchannel(cdev->dev.parent);
 626
 627         if (!list_empty(&sch->dev.children)) {
 628                 bus_rescan_devices(&ccw_bus_type);
 629                 goto out;
 630         }
 631         /* make it known to the system */
 632         ret = ccw_device_register(cdev);
 633         if (ret) {
 634                 printk (KERN_WARNING "%s: could not register %s\n",
 635                         __func__, cdev->dev.bus_id);
 636                 put_device(&cdev->dev);
 637                 sch->dev.driver_data = 0;
 638                 kfree (cdev->private);
 639                 kfree (cdev);
 640                 put_device(&sch->dev);
 641                 return;
 642         }
 643
 644         ret = subchannel_add_files(cdev->dev.parent);
 645         if (ret)
 646                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 647                        __func__, sch->dev.bus_id);
 648         put_device(&cdev->dev);
 649 out:
 650         cdev->private->flags.recog_done = 1;
 651         put_device(&sch->dev);
 652         wake_up(&cdev->private->wait_q);
 653 }
 654
 655 void
 656 ccw_device_call_sch_unregister(void *data)
 657 {
 658         struct ccw_device *cdev = data;
 659         struct subchannel *sch;
 660
 661         sch = to_subchannel(cdev->dev.parent);
 662         device_unregister(&sch->dev);
 663         /* Reset intparm to zeroes. */
 664         sch->schib.pmcw.intparm = 0;
 665         cio_modify(sch);
 666         put_device(&cdev->dev);
 667         put_device(&sch->dev);
 668 }
 669
 670 /*
 671  * subchannel recognition done. Called from the state machine.
 672  */
 673 void
 674 io_subchannel_recog_done(struct ccw_device *cdev)
 675 {
 676         struct subchannel *sch;
 677
 678         if (css_init_done == 0) {
 679                 cdev->private->flags.recog_done = 1;
 680                 return;
 681         }
 682         switch (cdev->private->state) {
 683         case DEV_STATE_NOT_OPER:
 684                 cdev->private->flags.recog_done = 1;
 685                 /* Remove device found not operational. */
 686                 if (!get_device(&cdev->dev))
 687                         break;
 688                 sch = to_subchannel(cdev->dev.parent);
 689                 INIT_WORK(&cdev->private->kick_work,
 690                           ccw_device_call_sch_unregister, (void *) cdev);
 691                 queue_work(slow_path_wq, &cdev->private->kick_work);
 692                 break;
 693         case DEV_STATE_BOXED:
 694                 /* Device did not respond in time. */
 695         case DEV_STATE_OFFLINE:
 696                 /*
 697                  * We can't register the device in interrupt context so
 698                  * we schedule a work item.
 699                  */
 700                 if (!get_device(&cdev->dev))
 701                         break;
 702                 INIT_WORK(&cdev->private->kick_work,
 703                           io_subchannel_register, (void *) cdev);
 704                 queue_work(ccw_device_work, &cdev->private->kick_work);
 705                 break;
 706         }
 707         if (atomic_dec_and_test(&ccw_device_init_count))
 708                 wake_up(&ccw_device_init_wq);
 709 }
 710
 711 static int
 712 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 713 {
 714         int rc;
 715         struct ccw_device_private *priv;
 716
 717         sch->dev.driver_data = cdev;
 718         sch->driver = &io_subchannel_driver;
 719         cdev->ccwlock = &sch->lock;
 720         /* Init private data. */
 721         priv = cdev->private;
 722         priv->devno = sch->schib.pmcw.dev;
 723         priv->irq = sch->irq;
 724         priv->state = DEV_STATE_NOT_OPER;
 725         INIT_LIST_HEAD(&priv->cmb_list);
 726         init_waitqueue_head(&priv->wait_q);
 727         init_timer(&priv->timer);
 728
 729         /* Set an initial name for the device. */
 730         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 731                   sch->schib.pmcw.dev);
 732
 733         /* Increase counter of devices currently in recognition. */
 734         atomic_inc(&ccw_device_init_count);
 735
 736         /* Start async. device sensing. */
 737         spin_lock_irq(&sch->lock);
 738         rc = ccw_device_recognition(cdev);
 739         spin_unlock_irq(&sch->lock);
 740         if (rc) {
 741                 if (atomic_dec_and_test(&ccw_device_init_count))
 742                         wake_up(&ccw_device_init_wq);
 743         }
 744         return rc;
 745 }
 746
 747 static int
 748 io_subchannel_probe (struct device *pdev)
 749 {
 750         struct subchannel *sch;
 751         struct ccw_device *cdev;
 752         int rc;
 753
 754         sch = to_subchannel(pdev);
 755         if (sch->dev.driver_data) {
 756                 /*
 757                  * This subchannel already has an associated ccw_device.
 758                  * Register it and exit. This happens for all early
 759                  * device, e.g. the console.
 760                  */
 761                 cdev = sch->dev.driver_data;
 762                 device_initialize(&cdev->dev);
 763                 ccw_device_register(cdev);
 764                 subchannel_add_files(&sch->dev);
 765                 /*
 766                  * Check if the device is already online. If it is
 767                  * the reference count needs to be corrected
 768                  * (see ccw_device_online and css_init_done for the
 769                  * ugly details).
 770                  */
 771                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 772                     cdev->private->state != DEV_STATE_OFFLINE &&
 773                     cdev->private->state != DEV_STATE_BOXED)
 774                         get_device(&cdev->dev);
 775                 return 0;
 776         }
 777         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 778         if (!cdev)
 779                 return -ENOMEM;
 780         memset(cdev, 0, sizeof(struct ccw_device));
 781         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 782                                 GFP_KERNEL | GFP_DMA);
 783         if (!cdev->private) {
 784                 kfree(cdev);
 785                 return -ENOMEM;
 786         }
 787         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 788         atomic_set(&cdev->private->onoff, 0);
 789         cdev->dev = (struct device) {
 790                 .parent = pdev,
 791                 .release = ccw_device_release,
 792         };
 793         /* Do first half of device_register. */
 794         device_initialize(&cdev->dev);
 795
 796         if (!get_device(&sch->dev)) {
 797                 if (cdev->dev.release)
 798                         cdev->dev.release(&cdev->dev);
 799                 return -ENODEV;
 800         }
 801
 802         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 803         if (rc) {
 804                 sch->dev.driver_data = 0;
 805                 if (cdev->dev.release)
 806                         cdev->dev.release(&cdev->dev);
 807         }
 808
 809         return rc;
 810 }
 811
 812 static int
 813 io_subchannel_remove (struct device *dev)
 814 {
 815         struct ccw_device *cdev;
 816
 817         if (!dev->driver_data)
 818                 return 0;
 819         cdev = dev->driver_data;
 820         /* Set ccw device to not operational and drop reference. */
 821         cdev->private->state = DEV_STATE_NOT_OPER;
 822         /*
 823          * Careful here. Our ccw device might be yet unregistered when
 824          * de-registering its subchannel (machine check during device
 825          * recognition). Better look if the subchannel has children.
 826          */
 827         if (!list_empty(&dev->children))
 828                 device_unregister(&cdev->dev);
 829         dev->driver_data = NULL;
 830         return 0;
 831 }
 832
 833 static int
 834 io_subchannel_notify(struct device *dev, int event)
 835 {
 836         struct ccw_device *cdev;
 837
 838         cdev = dev->driver_data;
 839         if (!cdev)
 840                 return 0;
 841         if (!cdev->drv)
 842                 return 0;
 843         if (!cdev->online)
 844                 return 0;
 845         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 846 }
 847
 848 static void
 849 io_subchannel_verify(struct device *dev)
 850 {
 851         struct ccw_device *cdev;
 852
 853         cdev = dev->driver_data;
 854         if (cdev)
 855                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 856 }
 857
 858 static void
 859 io_subchannel_ioterm(struct device *dev)
 860 {
 861         struct ccw_device *cdev;
 862
 863         cdev = dev->driver_data;
 864         if (!cdev)
 865                 return;
 866         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 867         if (cdev->handler)
 868                 cdev->handler(cdev, cdev->private->intparm,
 869                               ERR_PTR(-EIO));
 870 }
 871
 872 static void
 873 io_subchannel_shutdown(struct device *dev)
 874 {
 875         struct subchannel *sch;
 876         struct ccw_device *cdev;
 877         int ret;
 878
 879         sch = to_subchannel(dev);
 880         cdev = dev->driver_data;
 881
 882         if (cio_is_console(sch->irq))
 883                 return;
 884         if (!sch->schib.pmcw.ena)
 885                 /* Nothing to do. */
 886                 return;
 887         ret = cio_disable_subchannel(sch);
 888         if (ret != -EBUSY)
 889                 /* Subchannel is disabled, we're done. */
 890                 return;
 891         cdev->private->state = DEV_STATE_QUIESCE;
 892         if (cdev->handler)
 893                 cdev->handler(cdev, cdev->private->intparm,
 894                               ERR_PTR(-EIO));
 895         ret = ccw_device_cancel_halt_clear(cdev);
 896         if (ret == -EBUSY) {
 897                 ccw_device_set_timeout(cdev, HZ/10);
 898                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 899         }
 900         cio_disable_subchannel(sch);
 901 }
 902
 903 #ifdef CONFIG_CCW_CONSOLE
 904 static struct ccw_device console_cdev;
 905 static struct ccw_device_private console_private;
 906 static int console_cdev_in_use;
 907
 908 static int
 909 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 910 {
 911         int rc;
 912
 913         /* Initialize the ccw_device structure. */
 914         cdev->dev = (struct device) {
 915                 .parent = &sch->dev,
 916         };
 917         /* Initialize the subchannel structure */
 918         sch->dev.parent = &css_bus_device;
 919         sch->dev.bus = &css_bus_type;
 920
 921         rc = io_subchannel_recog(cdev, sch);
 922         if (rc)
 923                 return rc;
 924
 925         /* Now wait for the async. recognition to come to an end. */
 926         spin_lock_irq(cdev->ccwlock);
 927         while (!dev_fsm_final_state(cdev))
 928                 wait_cons_dev();
 929         rc = -EIO;
 930         if (cdev->private->state != DEV_STATE_OFFLINE)
 931                 goto out_unlock;
 932         ccw_device_online(cdev);
 933         while (!dev_fsm_final_state(cdev))
 934                 wait_cons_dev();
 935         if (cdev->private->state != DEV_STATE_ONLINE)
 936                 goto out_unlock;
 937         rc = 0;
 938 out_unlock:
 939         spin_unlock_irq(cdev->ccwlock);
 940         return 0;
 941 }
 942
 943 struct ccw_device *
 944 ccw_device_probe_console(void)
 945 {
 946         struct subchannel *sch;
 947         int ret;
 948
 949         if (xchg(&console_cdev_in_use, 1) != 0)
 950                 return NULL;
 951         sch = cio_probe_console();
 952         if (IS_ERR(sch)) {
 953                 console_cdev_in_use = 0;
 954                 return (void *) sch;
 955         }
 956         memset(&console_cdev, 0, sizeof(struct ccw_device));
 957         memset(&console_private, 0, sizeof(struct ccw_device_private));
 958         console_cdev.private = &console_private;
 959         ret = ccw_device_console_enable(&console_cdev, sch);
 960         if (ret) {
 961                 cio_release_console();
 962                 console_cdev_in_use = 0;
 963                 return ERR_PTR(ret);
 964         }
 965         console_cdev.online = 1;
 966         return &console_cdev;
 967 }
 968 #endif
 969
 970 /*
 971  * get ccw_device matching the busid, but only if owned by cdrv
 972  */
 973 struct ccw_device *
 974 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
 975 {
 976         struct device *d, *dev;
 977         struct device_driver *drv;
 978
 979         drv = get_driver(&cdrv->driver);
 980         if (!drv)
 981                 return 0;
 982
 983         down_read(&drv->bus->subsys.rwsem);
 984
 985         dev = NULL;
 986         list_for_each_entry(d, &drv->devices, driver_list) {
 987                 dev = get_device(d);
 988
 989                 if (dev && !strncmp(bus_id, dev->bus_id, BUS_ID_SIZE))
 990                         break;
 991                 else if (dev) {
 992                         put_device(dev);
 993                         dev = NULL;
 994                 }
 995         }
 996         up_read(&drv->bus->subsys.rwsem);
 997         put_driver(drv);
 998
 999         return dev ? to_ccwdev(dev) : 0;
1000 }
1001
1002 /************************** device driver handling ************************/
1003
1004 /* This is the implementation of the ccw_driver class. The probe, remove
1005  * and release methods are initially very similar to the device_driver
1006  * implementations, with the difference that they have ccw_device
1007  * arguments.
1008  *
1009  * A ccw driver also contains the information that is needed for
1010  * device matching.
1011  */
1012 static int
1013 ccw_device_probe (struct device *dev)
1014 {
1015         struct ccw_device *cdev = to_ccwdev(dev);
1016         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1017         int ret;
1018
1019         cdev->drv = cdrv; /* to let the driver call _set_online */
1020
1021         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1022
1023         if (ret) {
1024                 cdev->drv = 0;
1025                 return ret;
1026         }
1027
1028         return 0;
1029 }
1030
1031 static int
1032 ccw_device_remove (struct device *dev)
1033 {
1034         struct ccw_device *cdev = to_ccwdev(dev);
1035         struct ccw_driver *cdrv = cdev->drv;
1036         int ret;
1037
1038         pr_debug("removing device %s\n", cdev->dev.bus_id);
1039         if (cdrv->remove)
1040                 cdrv->remove(cdev);
1041         if (cdev->online) {
1042                 cdev->online = 0;
1043                 spin_lock_irq(cdev->ccwlock);
1044                 ret = ccw_device_offline(cdev);
1045                 spin_unlock_irq(cdev->ccwlock);
1046                 if (ret == 0)
1047                         wait_event(cdev->private->wait_q,
1048                                    dev_fsm_final_state(cdev));
1049                 else
1050                         //FIXME: we can't fail!
1051                         pr_debug("ccw_device_offline returned %d, device %s\n",
1052                                  ret, cdev->dev.bus_id);
1053         }
1054         ccw_device_set_timeout(cdev, 0);
1055         cdev->drv = 0;
1056         return 0;
1057 }
1058
1059 int
1060 ccw_driver_register (struct ccw_driver *cdriver)
1061 {
1062         struct device_driver *drv = &cdriver->driver;
1063
1064         drv->bus = &ccw_bus_type;
1065         drv->name = cdriver->name;
1066         drv->probe = ccw_device_probe;
1067         drv->remove = ccw_device_remove;
1068
1069         return driver_register(drv);
1070 }
1071
1072 void
1073 ccw_driver_unregister (struct ccw_driver *cdriver)
1074 {
1075         driver_unregister(&cdriver->driver);
1076 }
1077
1078 MODULE_LICENSE("GPL");
1079 EXPORT_SYMBOL(ccw_device_set_online);
1080 EXPORT_SYMBOL(ccw_device_set_offline);
1081 EXPORT_SYMBOL(ccw_driver_register);
1082 EXPORT_SYMBOL(ccw_driver_unregister);
1083 EXPORT_SYMBOL(get_ccwdev_by_busid);
1084 EXPORT_SYMBOL(ccw_bus_type);
1085 EXPORT_SYMBOL(ccw_device_work);
1086 EXPORT_SYMBOL(ccw_device_notify_work);