drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.129 $
   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         /* what we want to pass to /sbin/hotplug */
  72
  73         envp[i++] = buffer;
  74         length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
  75                            cdev->id.cu_type);
  76         if ((buffer_size - length <= 0) || (i >= num_envp))
  77                 return -ENOMEM;
  78         ++length;
  79         buffer += length;
  80
  81         envp[i++] = buffer;
  82         length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
  83                            cdev->id.cu_model);
  84         if ((buffer_size - length <= 0) || (i >= num_envp))
  85                 return -ENOMEM;
  86         ++length;
  87         buffer += length;
  88
  89         /* The next two can be zero, that's ok for us */
  90         envp[i++] = buffer;
  91         length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
  92                            cdev->id.dev_type);
  93         if ((buffer_size - length <= 0) || (i >= num_envp))
  94                 return -ENOMEM;
  95         ++length;
  96         buffer += length;
  97
  98         envp[i++] = buffer;
  99         length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
 100                            cdev->id.dev_model);
 101         if ((buffer_size - length <= 0) || (i >= num_envp))
 102                 return -ENOMEM;
 103
 104         envp[i] = 0;
 105
 106         return 0;
 107 }
 108
 109 struct bus_type ccw_bus_type = {
 110         .name  = "ccw",
 111         .match = &ccw_bus_match,
 112         .hotplug = &ccw_hotplug,
 113 };
 114
 115 static int io_subchannel_probe (struct device *);
 116 static int io_subchannel_remove (struct device *);
 117 void io_subchannel_irq (struct device *);
 118 static int io_subchannel_notify(struct device *, int);
 119 static void io_subchannel_verify(struct device *);
 120 static void io_subchannel_ioterm(struct device *);
 121 static void io_subchannel_shutdown(struct device *);
 122
 123 struct css_driver io_subchannel_driver = {
 124         .subchannel_type = SUBCHANNEL_TYPE_IO,
 125         .drv = {
 126                 .name = "io_subchannel",
 127                 .bus  = &css_bus_type,
 128                 .probe = &io_subchannel_probe,
 129                 .remove = &io_subchannel_remove,
 130                 .shutdown = &io_subchannel_shutdown,
 131         },
 132         .irq = io_subchannel_irq,
 133         .notify = io_subchannel_notify,
 134         .verify = io_subchannel_verify,
 135         .termination = io_subchannel_ioterm,
 136 };
 137
 138 struct workqueue_struct *ccw_device_work;
 139 struct workqueue_struct *ccw_device_notify_work;
 140 static wait_queue_head_t ccw_device_init_wq;
 141 static atomic_t ccw_device_init_count;
 142
 143 static int __init
 144 init_ccw_bus_type (void)
 145 {
 146         int ret;
 147
 148         init_waitqueue_head(&ccw_device_init_wq);
 149         atomic_set(&ccw_device_init_count, 0);
 150
 151         ccw_device_work = create_singlethread_workqueue("cio");
 152         if (!ccw_device_work)
 153                 return -ENOMEM; /* FIXME: better errno ? */
 154         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 155         if (!ccw_device_notify_work) {
 156                 ret = -ENOMEM; /* FIXME: better errno ? */
 157                 goto out_err;
 158         }
 159         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 160         if (!slow_path_wq) {
 161                 ret = -ENOMEM; /* FIXME: better errno ? */
 162                 goto out_err;
 163         }
 164         if ((ret = bus_register (&ccw_bus_type)))
 165                 goto out_err;
 166
 167         if ((ret = driver_register(&io_subchannel_driver.drv)))
 168                 goto out_err;
 169
 170         wait_event(ccw_device_init_wq,
 171                    atomic_read(&ccw_device_init_count) == 0);
 172         flush_workqueue(ccw_device_work);
 173         return 0;
 174 out_err:
 175         if (ccw_device_work)
 176                 destroy_workqueue(ccw_device_work);
 177         if (ccw_device_notify_work)
 178                 destroy_workqueue(ccw_device_notify_work);
 179         if (slow_path_wq)
 180                 destroy_workqueue(slow_path_wq);
 181         return ret;
 182 }
 183
 184 static void __exit
 185 cleanup_ccw_bus_type (void)
 186 {
 187         driver_unregister(&io_subchannel_driver.drv);
 188         bus_unregister(&ccw_bus_type);
 189         destroy_workqueue(ccw_device_notify_work);
 190         destroy_workqueue(ccw_device_work);
 191 }
 192
 193 subsys_initcall(init_ccw_bus_type);
 194 module_exit(cleanup_ccw_bus_type);
 195
 196 /************************ device handling **************************/
 197
 198 /*
 199  * A ccw_device has some interfaces in sysfs in addition to the
 200  * standard ones.
 201  * The following entries are designed to export the information which
 202  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 203  * are obvious, so they don't have an entry :)
 204  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 205  */
 206 static ssize_t
 207 chpids_show (struct device * dev, char * buf)
 208 {
 209         struct subchannel *sch = to_subchannel(dev);
 210         struct ssd_info *ssd = &sch->ssd_info;
 211         ssize_t ret = 0;
 212         int chp;
 213
 214         for (chp = 0; chp < 8; chp++)
 215                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 216
 217         ret += sprintf (buf+ret, "\n");
 218         return min((ssize_t)PAGE_SIZE, ret);
 219 }
 220
 221 static ssize_t
 222 pimpampom_show (struct device * dev, char * buf)
 223 {
 224         struct subchannel *sch = to_subchannel(dev);
 225         struct pmcw *pmcw = &sch->schib.pmcw;
 226
 227         return sprintf (buf, "%02x %02x %02x\n",
 228                         pmcw->pim, pmcw->pam, pmcw->pom);
 229 }
 230
 231 static ssize_t
 232 devtype_show (struct device *dev, char *buf)
 233 {
 234         struct ccw_device *cdev = to_ccwdev(dev);
 235         struct ccw_device_id *id = &(cdev->id);
 236
 237         if (id->dev_type != 0)
 238                 return sprintf(buf, "%04x/%02x\n",
 239                                 id->dev_type, id->dev_model);
 240         else
 241                 return sprintf(buf, "n/a\n");
 242 }
 243
 244 static ssize_t
 245 cutype_show (struct device *dev, char *buf)
 246 {
 247         struct ccw_device *cdev = to_ccwdev(dev);
 248         struct ccw_device_id *id = &(cdev->id);
 249
 250         return sprintf(buf, "%04x/%02x\n",
 251                        id->cu_type, id->cu_model);
 252 }
 253
 254 static ssize_t
 255 online_show (struct device *dev, char *buf)
 256 {
 257         struct ccw_device *cdev = to_ccwdev(dev);
 258
 259         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 260 }
 261
 262 static void
 263 ccw_device_remove_disconnected(struct ccw_device *cdev)
 264 {
 265         struct subchannel *sch;
 266         /*
 267          * Forced offline in disconnected state means
 268          * 'throw away device'.
 269          */
 270         sch = to_subchannel(cdev->dev.parent);
 271         device_unregister(&sch->dev);
 272         /* Reset intparm to zeroes. */
 273         sch->schib.pmcw.intparm = 0;
 274         cio_modify(sch);
 275         put_device(&sch->dev);
 276 }
 277
 278 int
 279 ccw_device_set_offline(struct ccw_device *cdev)
 280 {
 281         int ret;
 282
 283         if (!cdev)
 284                 return -ENODEV;
 285         if (!cdev->online || !cdev->drv)
 286                 return -EINVAL;
 287
 288         if (cdev->drv->set_offline) {
 289                 ret = cdev->drv->set_offline(cdev);
 290                 if (ret != 0)
 291                         return ret;
 292         }
 293         cdev->online = 0;
 294         spin_lock_irq(cdev->ccwlock);
 295         ret = ccw_device_offline(cdev);
 296         spin_unlock_irq(cdev->ccwlock);
 297         if (ret == 0)
 298                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 299         else {
 300                 pr_debug("ccw_device_offline returned %d, device %s\n",
 301                          ret, cdev->dev.bus_id);
 302                 cdev->online = 1;
 303         }
 304         return ret;
 305 }
 306
 307 int
 308 ccw_device_set_online(struct ccw_device *cdev)
 309 {
 310         int ret;
 311
 312         if (!cdev)
 313                 return -ENODEV;
 314         if (cdev->online || !cdev->drv)
 315                 return -EINVAL;
 316
 317         spin_lock_irq(cdev->ccwlock);
 318         ret = ccw_device_online(cdev);
 319         spin_unlock_irq(cdev->ccwlock);
 320         if (ret == 0)
 321                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 322         else {
 323                 pr_debug("ccw_device_online returned %d, device %s\n",
 324                          ret, cdev->dev.bus_id);
 325                 return ret;
 326         }
 327         if (cdev->private->state != DEV_STATE_ONLINE)
 328                 return -ENODEV;
 329         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 330                 cdev->online = 1;
 331                 return 0;
 332         }
 333         spin_lock_irq(cdev->ccwlock);
 334         ret = ccw_device_offline(cdev);
 335         spin_unlock_irq(cdev->ccwlock);
 336         if (ret == 0)
 337                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 338         else
 339                 pr_debug("ccw_device_offline returned %d, device %s\n",
 340                          ret, cdev->dev.bus_id);
 341         return (ret = 0) ? -ENODEV : ret;
 342 }
 343
 344 static ssize_t
 345 online_store (struct device *dev, const char *buf, size_t count)
 346 {
 347         struct ccw_device *cdev = to_ccwdev(dev);
 348         int i, force, ret;
 349         char *tmp;
 350
 351         if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
 352                 return -EAGAIN;
 353
 354         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 355                 atomic_set(&cdev->private->onoff, 0);
 356                 return -EINVAL;
 357         }
 358         if (!strncmp(buf, "force\n", count)) {
 359                 force = 1;
 360                 i = 1;
 361         } else {
 362                 force = 0;
 363                 i = simple_strtoul(buf, &tmp, 16);
 364         }
 365         if (i == 1) {
 366                 /* Do device recognition, if needed. */
 367                 if (cdev->id.cu_type == 0) {
 368                         ret = ccw_device_recognition(cdev);
 369                         if (ret) {
 370                                 printk(KERN_WARNING"Couldn't start recognition "
 371                                        "for device %s (ret=%d)\n",
 372                                        cdev->dev.bus_id, ret);
 373                                 goto out;
 374                         }
 375                         wait_event(cdev->private->wait_q,
 376                                    cdev->private->flags.recog_done);
 377                 }
 378                 if (cdev->drv && cdev->drv->set_online)
 379                         ccw_device_set_online(cdev);
 380         } else if (i == 0) {
 381                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 382                         ccw_device_remove_disconnected(cdev);
 383                 else if (cdev->drv && cdev->drv->set_offline)
 384                         ccw_device_set_offline(cdev);
 385         }
 386         if (force && cdev->private->state == DEV_STATE_BOXED) {
 387                 ret = ccw_device_stlck(cdev);
 388                 if (ret) {
 389                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 390                                "returned %d!\n", cdev->dev.bus_id, ret);
 391                         goto out;
 392                 }
 393                 /* Do device recognition, if needed. */
 394                 if (cdev->id.cu_type == 0) {
 395                         cdev->private->state = DEV_STATE_NOT_OPER;
 396                         ret = ccw_device_recognition(cdev);
 397                         if (ret) {
 398                                 printk(KERN_WARNING"Couldn't start recognition "
 399                                        "for device %s (ret=%d)\n",
 400                                        cdev->dev.bus_id, ret);
 401                                 goto out;
 402                         }
 403                         wait_event(cdev->private->wait_q,
 404                                    cdev->private->flags.recog_done);
 405                 }
 406                 if (cdev->drv && cdev->drv->set_online)
 407                         ccw_device_set_online(cdev);
 408         }
 409         out:
 410         if (cdev->drv)
 411                 module_put(cdev->drv->owner);
 412         atomic_set(&cdev->private->onoff, 0);
 413         return count;
 414 }
 415
 416 static ssize_t
 417 available_show (struct device *dev, char *buf)
 418 {
 419         struct ccw_device *cdev = to_ccwdev(dev);
 420         struct subchannel *sch;
 421
 422         switch (cdev->private->state) {
 423         case DEV_STATE_BOXED:
 424                 return sprintf(buf, "boxed\n");
 425         case DEV_STATE_DISCONNECTED:
 426         case DEV_STATE_DISCONNECTED_SENSE_ID:
 427         case DEV_STATE_NOT_OPER:
 428                 sch = to_subchannel(dev->parent);
 429                 if (!sch->lpm)
 430                         return sprintf(buf, "no path\n");
 431                 else
 432                         return sprintf(buf, "no device\n");
 433         default:
 434                 /* All other states considered fine. */
 435                 return sprintf(buf, "good\n");
 436         }
 437 }
 438
 439 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 440 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 441 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 442 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 443 static DEVICE_ATTR(online, 0644, online_show, online_store);
 444 extern struct device_attribute dev_attr_cmb_enable;
 445 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 446
 447 static struct attribute * subch_attrs[] = {
 448         &dev_attr_chpids.attr,
 449         &dev_attr_pimpampom.attr,
 450         NULL,
 451 };
 452
 453 static struct attribute_group subch_attr_group = {
 454         .attrs = subch_attrs,
 455 };
 456
 457 static inline int
 458 subchannel_add_files (struct device *dev)
 459 {
 460         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 461 }
 462
 463 static struct attribute * ccwdev_attrs[] = {
 464         &dev_attr_devtype.attr,
 465         &dev_attr_cutype.attr,
 466         &dev_attr_online.attr,
 467         &dev_attr_cmb_enable.attr,
 468         &dev_attr_availability.attr,
 469         NULL,
 470 };
 471
 472 static struct attribute_group ccwdev_attr_group = {
 473         .attrs = ccwdev_attrs,
 474 };
 475
 476 static inline int
 477 device_add_files (struct device *dev)
 478 {
 479         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 480 }
 481
 482 static inline void
 483 device_remove_files(struct device *dev)
 484 {
 485         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 486 }
 487
 488 /* this is a simple abstraction for device_register that sets the
 489  * correct bus type and adds the bus specific files */
 490 int
 491 ccw_device_register(struct ccw_device *cdev)
 492 {
 493         struct device *dev = &cdev->dev;
 494         int ret;
 495
 496         dev->bus = &ccw_bus_type;
 497
 498         if ((ret = device_add(dev)))
 499                 return ret;
 500
 501         set_bit(1, &cdev->private->registered);
 502         if ((ret = device_add_files(dev))) {
 503                 if (test_and_clear_bit(1, &cdev->private->registered))
 504                         device_del(dev);
 505         }
 506         return ret;
 507 }
 508
 509 static struct ccw_device *
 510 get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
 511 {
 512         struct ccw_device *cdev;
 513         struct list_head *entry;
 514         struct device *dev;
 515
 516         if (!get_bus(&ccw_bus_type))
 517                 return NULL;
 518         down_read(&ccw_bus_type.subsys.rwsem);
 519         cdev = NULL;
 520         list_for_each(entry, &ccw_bus_type.devices.list) {
 521                 dev = get_device(container_of(entry,
 522                                               struct device, bus_list));
 523                 if (!dev)
 524                         continue;
 525                 cdev = to_ccwdev(dev);
 526                 if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 527                     (cdev->private->devno == devno) &&
 528                     (cdev != sibling)) {
 529                         cdev->private->state = DEV_STATE_NOT_OPER;
 530                         break;
 531                 }
 532                 put_device(dev);
 533                 cdev = NULL;
 534         }
 535         up_read(&ccw_bus_type.subsys.rwsem);
 536         put_bus(&ccw_bus_type);
 537
 538         return cdev;
 539 }
 540
 541 static void
 542 ccw_device_add_changed(void *data)
 543 {
 544
 545         struct ccw_device *cdev;
 546
 547         cdev = (struct ccw_device *)data;
 548         if (device_add(&cdev->dev)) {
 549                 put_device(&cdev->dev);
 550                 return;
 551         }
 552         set_bit(1, &cdev->private->registered);
 553         if (device_add_files(&cdev->dev)) {
 554                 if (test_and_clear_bit(1, &cdev->private->registered))
 555                         device_unregister(&cdev->dev);
 556         }
 557 }
 558
 559 extern int css_get_ssd_info(struct subchannel *sch);
 560
 561 void
 562 ccw_device_do_unreg_rereg(void *data)
 563 {
 564         struct ccw_device *cdev;
 565         struct subchannel *sch;
 566         int need_rename;
 567
 568         cdev = (struct ccw_device *)data;
 569         sch = to_subchannel(cdev->dev.parent);
 570         if (cdev->private->devno != sch->schib.pmcw.dev) {
 571                 /*
 572                  * The device number has changed. This is usually only when
 573                  * a device has been detached under VM and then re-appeared
 574                  * on another subchannel because of a different attachment
 575                  * order than before. Ideally, we should should just switch
 576                  * subchannels, but unfortunately, this is not possible with
 577                  * the current implementation.
 578                  * Instead, we search for the old subchannel for this device
 579                  * number and deregister so there are no collisions with the
 580                  * newly registered ccw_device.
 581                  * FIXME: Find another solution so the block layer doesn't
 582                  *        get possibly sick...
 583                  */
 584                 struct ccw_device *other_cdev;
 585
 586                 need_rename = 1;
 587                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 588                                                       cdev);
 589                 if (other_cdev) {
 590                         struct subchannel *other_sch;
 591
 592                         other_sch = to_subchannel(other_cdev->dev.parent);
 593                         if (get_device(&other_sch->dev)) {
 594                                 stsch(other_sch->irq, &other_sch->schib);
 595                                 if (other_sch->schib.pmcw.dnv) {
 596                                         other_sch->schib.pmcw.intparm = 0;
 597                                         cio_modify(other_sch);
 598                                 }
 599                                 device_unregister(&other_sch->dev);
 600                         }
 601                 }
 602                 /* Update ssd info here. */
 603                 css_get_ssd_info(sch);
 604                 cdev->private->devno = sch->schib.pmcw.dev;
 605         } else
 606                 need_rename = 0;
 607         device_remove_files(&cdev->dev);
 608         if (test_and_clear_bit(1, &cdev->private->registered))
 609                 device_del(&cdev->dev);
 610         if (need_rename)
 611                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 612                           sch->schib.pmcw.dev);
 613         PREPARE_WORK(&cdev->private->kick_work,
 614                      ccw_device_add_changed, (void *)cdev);
 615         queue_work(ccw_device_work, &cdev->private->kick_work);
 616 }
 617
 618 static void
 619 ccw_device_release(struct device *dev)
 620 {
 621         struct ccw_device *cdev;
 622
 623         cdev = to_ccwdev(dev);
 624         kfree(cdev->private);
 625         kfree(cdev);
 626 }
 627
 628 /*
 629  * Register recognized device.
 630  */
 631 static void
 632 io_subchannel_register(void *data)
 633 {
 634         struct ccw_device *cdev;
 635         struct subchannel *sch;
 636         int ret;
 637         unsigned long flags;
 638
 639         cdev = (struct ccw_device *) data;
 640         sch = to_subchannel(cdev->dev.parent);
 641
 642         if (!list_empty(&sch->dev.children)) {
 643                 bus_rescan_devices(&ccw_bus_type);
 644                 goto out;
 645         }
 646         /* make it known to the system */
 647         ret = ccw_device_register(cdev);
 648         if (ret) {
 649                 printk (KERN_WARNING "%s: could not register %s\n",
 650                         __func__, cdev->dev.bus_id);
 651                 put_device(&cdev->dev);
 652                 spin_lock_irqsave(&sch->lock, flags);
 653                 sch->dev.driver_data = NULL;
 654                 spin_unlock_irqrestore(&sch->lock, flags);
 655                 kfree (cdev->private);
 656                 kfree (cdev);
 657                 put_device(&sch->dev);
 658                 if (atomic_dec_and_test(&ccw_device_init_count))
 659                         wake_up(&ccw_device_init_wq);
 660                 return;
 661         }
 662
 663         ret = subchannel_add_files(cdev->dev.parent);
 664         if (ret)
 665                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 666                        __func__, sch->dev.bus_id);
 667         put_device(&cdev->dev);
 668 out:
 669         cdev->private->flags.recog_done = 1;
 670         put_device(&sch->dev);
 671         wake_up(&cdev->private->wait_q);
 672         if (atomic_dec_and_test(&ccw_device_init_count))
 673                 wake_up(&ccw_device_init_wq);
 674 }
 675
 676 void
 677 ccw_device_call_sch_unregister(void *data)
 678 {
 679         struct ccw_device *cdev = data;
 680         struct subchannel *sch;
 681
 682         sch = to_subchannel(cdev->dev.parent);
 683         device_unregister(&sch->dev);
 684         /* Reset intparm to zeroes. */
 685         sch->schib.pmcw.intparm = 0;
 686         cio_modify(sch);
 687         put_device(&cdev->dev);
 688         put_device(&sch->dev);
 689 }
 690
 691 /*
 692  * subchannel recognition done. Called from the state machine.
 693  */
 694 void
 695 io_subchannel_recog_done(struct ccw_device *cdev)
 696 {
 697         struct subchannel *sch;
 698
 699         if (css_init_done == 0) {
 700                 cdev->private->flags.recog_done = 1;
 701                 return;
 702         }
 703         switch (cdev->private->state) {
 704         case DEV_STATE_NOT_OPER:
 705                 cdev->private->flags.recog_done = 1;
 706                 /* Remove device found not operational. */
 707                 if (!get_device(&cdev->dev))
 708                         break;
 709                 sch = to_subchannel(cdev->dev.parent);
 710                 PREPARE_WORK(&cdev->private->kick_work,
 711                              ccw_device_call_sch_unregister, (void *) cdev);
 712                 queue_work(slow_path_wq, &cdev->private->kick_work);
 713                 if (atomic_dec_and_test(&ccw_device_init_count))
 714                         wake_up(&ccw_device_init_wq);
 715                 break;
 716         case DEV_STATE_BOXED:
 717                 /* Device did not respond in time. */
 718         case DEV_STATE_OFFLINE:
 719                 /*
 720                  * We can't register the device in interrupt context so
 721                  * we schedule a work item.
 722                  */
 723                 if (!get_device(&cdev->dev))
 724                         break;
 725                 PREPARE_WORK(&cdev->private->kick_work,
 726                              io_subchannel_register, (void *) cdev);
 727                 queue_work(slow_path_wq, &cdev->private->kick_work);
 728                 break;
 729         }
 730 }
 731
 732 static int
 733 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 734 {
 735         int rc;
 736         struct ccw_device_private *priv;
 737
 738         sch->dev.driver_data = cdev;
 739         sch->driver = &io_subchannel_driver;
 740         cdev->ccwlock = &sch->lock;
 741         /* Init private data. */
 742         priv = cdev->private;
 743         priv->devno = sch->schib.pmcw.dev;
 744         priv->irq = sch->irq;
 745         priv->state = DEV_STATE_NOT_OPER;
 746         INIT_LIST_HEAD(&priv->cmb_list);
 747         init_waitqueue_head(&priv->wait_q);
 748         init_timer(&priv->timer);
 749
 750         /* Set an initial name for the device. */
 751         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 752                   sch->schib.pmcw.dev);
 753
 754         /* Increase counter of devices currently in recognition. */
 755         atomic_inc(&ccw_device_init_count);
 756
 757         /* Start async. device sensing. */
 758         spin_lock_irq(&sch->lock);
 759         rc = ccw_device_recognition(cdev);
 760         spin_unlock_irq(&sch->lock);
 761         if (rc) {
 762                 if (atomic_dec_and_test(&ccw_device_init_count))
 763                         wake_up(&ccw_device_init_wq);
 764         }
 765         return rc;
 766 }
 767
 768 static int
 769 io_subchannel_probe (struct device *pdev)
 770 {
 771         struct subchannel *sch;
 772         struct ccw_device *cdev;
 773         int rc;
 774         unsigned long flags;
 775
 776         sch = to_subchannel(pdev);
 777         if (sch->dev.driver_data) {
 778                 /*
 779                  * This subchannel already has an associated ccw_device.
 780                  * Register it and exit. This happens for all early
 781                  * device, e.g. the console.
 782                  */
 783                 cdev = sch->dev.driver_data;
 784                 device_initialize(&cdev->dev);
 785                 ccw_device_register(cdev);
 786                 subchannel_add_files(&sch->dev);
 787                 /*
 788                  * Check if the device is already online. If it is
 789                  * the reference count needs to be corrected
 790                  * (see ccw_device_online and css_init_done for the
 791                  * ugly details).
 792                  */
 793                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 794                     cdev->private->state != DEV_STATE_OFFLINE &&
 795                     cdev->private->state != DEV_STATE_BOXED)
 796                         get_device(&cdev->dev);
 797                 return 0;
 798         }
 799         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 800         if (!cdev)
 801                 return -ENOMEM;
 802         memset(cdev, 0, sizeof(struct ccw_device));
 803         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 804                                 GFP_KERNEL | GFP_DMA);
 805         if (!cdev->private) {
 806                 kfree(cdev);
 807                 return -ENOMEM;
 808         }
 809         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 810         atomic_set(&cdev->private->onoff, 0);
 811         cdev->dev = (struct device) {
 812                 .parent = pdev,
 813                 .release = ccw_device_release,
 814         };
 815         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 816         /* Do first half of device_register. */
 817         device_initialize(&cdev->dev);
 818
 819         if (!get_device(&sch->dev)) {
 820                 if (cdev->dev.release)
 821                         cdev->dev.release(&cdev->dev);
 822                 return -ENODEV;
 823         }
 824
 825         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 826         if (rc) {
 827                 spin_lock_irqsave(&sch->lock, flags);
 828                 sch->dev.driver_data = NULL;
 829                 spin_unlock_irqrestore(&sch->lock, flags);
 830                 if (cdev->dev.release)
 831                         cdev->dev.release(&cdev->dev);
 832         }
 833
 834         return rc;
 835 }
 836
 837 static void
 838 ccw_device_unregister(void *data)
 839 {
 840         struct ccw_device *cdev;
 841
 842         cdev = (struct ccw_device *)data;
 843         if (test_and_clear_bit(1, &cdev->private->registered))
 844                 device_unregister(&cdev->dev);
 845         put_device(&cdev->dev);
 846 }
 847
 848 static int
 849 io_subchannel_remove (struct device *dev)
 850 {
 851         struct ccw_device *cdev;
 852         unsigned long flags;
 853
 854         if (!dev->driver_data)
 855                 return 0;
 856         cdev = dev->driver_data;
 857         /* Set ccw device to not operational and drop reference. */
 858         spin_lock_irqsave(cdev->ccwlock, flags);
 859         dev->driver_data = NULL;
 860         cdev->private->state = DEV_STATE_NOT_OPER;
 861         spin_unlock_irqrestore(cdev->ccwlock, flags);
 862         /*
 863          * Put unregistration on workqueue to avoid livelocks on the css bus
 864          * semaphore.
 865          */
 866         if (get_device(&cdev->dev)) {
 867                 PREPARE_WORK(&cdev->private->kick_work,
 868                              ccw_device_unregister, (void *) cdev);
 869                 queue_work(ccw_device_work, &cdev->private->kick_work);
 870         }
 871         return 0;
 872 }
 873
 874 static int
 875 io_subchannel_notify(struct device *dev, int event)
 876 {
 877         struct ccw_device *cdev;
 878
 879         cdev = dev->driver_data;
 880         if (!cdev)
 881                 return 0;
 882         if (!cdev->drv)
 883                 return 0;
 884         if (!cdev->online)
 885                 return 0;
 886         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 887 }
 888
 889 static void
 890 io_subchannel_verify(struct device *dev)
 891 {
 892         struct ccw_device *cdev;
 893
 894         cdev = dev->driver_data;
 895         if (cdev)
 896                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 897 }
 898
 899 static void
 900 io_subchannel_ioterm(struct device *dev)
 901 {
 902         struct ccw_device *cdev;
 903
 904         cdev = dev->driver_data;
 905         if (!cdev)
 906                 return;
 907         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 908         if (cdev->handler)
 909                 cdev->handler(cdev, cdev->private->intparm,
 910                               ERR_PTR(-EIO));
 911 }
 912
 913 static void
 914 io_subchannel_shutdown(struct device *dev)
 915 {
 916         struct subchannel *sch;
 917         struct ccw_device *cdev;
 918         int ret;
 919
 920         sch = to_subchannel(dev);
 921         cdev = dev->driver_data;
 922
 923         if (cio_is_console(sch->irq))
 924                 return;
 925         if (!sch->schib.pmcw.ena)
 926                 /* Nothing to do. */
 927                 return;
 928         ret = cio_disable_subchannel(sch);
 929         if (ret != -EBUSY)
 930                 /* Subchannel is disabled, we're done. */
 931                 return;
 932         cdev->private->state = DEV_STATE_QUIESCE;
 933         if (cdev->handler)
 934                 cdev->handler(cdev, cdev->private->intparm,
 935                               ERR_PTR(-EIO));
 936         ret = ccw_device_cancel_halt_clear(cdev);
 937         if (ret == -EBUSY) {
 938                 ccw_device_set_timeout(cdev, HZ/10);
 939                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 940         }
 941         cio_disable_subchannel(sch);
 942 }
 943
 944 #ifdef CONFIG_CCW_CONSOLE
 945 static struct ccw_device console_cdev;
 946 static struct ccw_device_private console_private;
 947 static int console_cdev_in_use;
 948
 949 static int
 950 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 951 {
 952         int rc;
 953
 954         /* Initialize the ccw_device structure. */
 955         cdev->dev = (struct device) {
 956                 .parent = &sch->dev,
 957         };
 958         /* Initialize the subchannel structure */
 959         sch->dev.parent = &css_bus_device;
 960         sch->dev.bus = &css_bus_type;
 961
 962         rc = io_subchannel_recog(cdev, sch);
 963         if (rc)
 964                 return rc;
 965
 966         /* Now wait for the async. recognition to come to an end. */
 967         spin_lock_irq(cdev->ccwlock);
 968         while (!dev_fsm_final_state(cdev))
 969                 wait_cons_dev();
 970         rc = -EIO;
 971         if (cdev->private->state != DEV_STATE_OFFLINE)
 972                 goto out_unlock;
 973         ccw_device_online(cdev);
 974         while (!dev_fsm_final_state(cdev))
 975                 wait_cons_dev();
 976         if (cdev->private->state != DEV_STATE_ONLINE)
 977                 goto out_unlock;
 978         rc = 0;
 979 out_unlock:
 980         spin_unlock_irq(cdev->ccwlock);
 981         return 0;
 982 }
 983
 984 struct ccw_device *
 985 ccw_device_probe_console(void)
 986 {
 987         struct subchannel *sch;
 988         int ret;
 989
 990         if (xchg(&console_cdev_in_use, 1) != 0)
 991                 return NULL;
 992         sch = cio_probe_console();
 993         if (IS_ERR(sch)) {
 994                 console_cdev_in_use = 0;
 995                 return (void *) sch;
 996         }
 997         memset(&console_cdev, 0, sizeof(struct ccw_device));
 998         memset(&console_private, 0, sizeof(struct ccw_device_private));
 999         console_cdev.private = &console_private;
1000         ret = ccw_device_console_enable(&console_cdev, sch);
1001         if (ret) {
1002                 cio_release_console();
1003                 console_cdev_in_use = 0;
1004                 return ERR_PTR(ret);
1005         }
1006         console_cdev.online = 1;
1007         return &console_cdev;
1008 }
1009 #endif
1010
1011 /*
1012  * get ccw_device matching the busid, but only if owned by cdrv
1013  */
1014 struct ccw_device *
1015 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1016 {
1017         struct device *d, *dev;
1018         struct device_driver *drv;
1019
1020         drv = get_driver(&cdrv->driver);
1021         if (!drv)
1022                 return 0;
1023
1024         down_read(&drv->bus->subsys.rwsem);
1025
1026         dev = NULL;
1027         list_for_each_entry(d, &drv->devices, driver_list) {
1028                 dev = get_device(d);
1029
1030                 if (dev && !strncmp(bus_id, dev->bus_id, BUS_ID_SIZE))
1031                         break;
1032                 else if (dev) {
1033                         put_device(dev);
1034                         dev = NULL;
1035                 }
1036         }
1037         up_read(&drv->bus->subsys.rwsem);
1038         put_driver(drv);
1039
1040         return dev ? to_ccwdev(dev) : 0;
1041 }
1042
1043 /************************** device driver handling ************************/
1044
1045 /* This is the implementation of the ccw_driver class. The probe, remove
1046  * and release methods are initially very similar to the device_driver
1047  * implementations, with the difference that they have ccw_device
1048  * arguments.
1049  *
1050  * A ccw driver also contains the information that is needed for
1051  * device matching.
1052  */
1053 static int
1054 ccw_device_probe (struct device *dev)
1055 {
1056         struct ccw_device *cdev = to_ccwdev(dev);
1057         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1058         int ret;
1059
1060         cdev->drv = cdrv; /* to let the driver call _set_online */
1061
1062         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1063
1064         if (ret) {
1065                 cdev->drv = 0;
1066                 return ret;
1067         }
1068
1069         return 0;
1070 }
1071
1072 static int
1073 ccw_device_remove (struct device *dev)
1074 {
1075         struct ccw_device *cdev = to_ccwdev(dev);
1076         struct ccw_driver *cdrv = cdev->drv;
1077         int ret;
1078
1079         pr_debug("removing device %s\n", cdev->dev.bus_id);
1080         if (cdrv->remove)
1081                 cdrv->remove(cdev);
1082         if (cdev->online) {
1083                 cdev->online = 0;
1084                 spin_lock_irq(cdev->ccwlock);
1085                 ret = ccw_device_offline(cdev);
1086                 spin_unlock_irq(cdev->ccwlock);
1087                 if (ret == 0)
1088                         wait_event(cdev->private->wait_q,
1089                                    dev_fsm_final_state(cdev));
1090                 else
1091                         //FIXME: we can't fail!
1092                         pr_debug("ccw_device_offline returned %d, device %s\n",
1093                                  ret, cdev->dev.bus_id);
1094         }
1095         ccw_device_set_timeout(cdev, 0);
1096         cdev->drv = 0;
1097         return 0;
1098 }
1099
1100 int
1101 ccw_driver_register (struct ccw_driver *cdriver)
1102 {
1103         struct device_driver *drv = &cdriver->driver;
1104
1105         drv->bus = &ccw_bus_type;
1106         drv->name = cdriver->name;
1107         drv->probe = ccw_device_probe;
1108         drv->remove = ccw_device_remove;
1109
1110         return driver_register(drv);
1111 }
1112
1113 void
1114 ccw_driver_unregister (struct ccw_driver *cdriver)
1115 {
1116         driver_unregister(&cdriver->driver);
1117 }
1118
1119 MODULE_LICENSE("GPL");
1120 EXPORT_SYMBOL(ccw_device_set_online);
1121 EXPORT_SYMBOL(ccw_device_set_offline);
1122 EXPORT_SYMBOL(ccw_driver_register);
1123 EXPORT_SYMBOL(ccw_driver_unregister);
1124 EXPORT_SYMBOL(get_ccwdev_by_busid);
1125 EXPORT_SYMBOL(ccw_bus_type);
1126 EXPORT_SYMBOL(ccw_device_work);
1127 EXPORT_SYMBOL(ccw_device_notify_work);