drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.131 $
   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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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         if (ret == -ENODEV) {
 297                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 298                         cdev->private->state = DEV_STATE_OFFLINE;
 299                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 300                 }
 301                 spin_unlock_irq(cdev->ccwlock);
 302                 return ret;
 303         }
 304         spin_unlock_irq(cdev->ccwlock);
 305         if (ret == 0)
 306                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 307         else {
 308                 pr_debug("ccw_device_offline returned %d, device %s\n",
 309                          ret, cdev->dev.bus_id);
 310                 cdev->online = 1;
 311         }
 312         return ret;
 313 }
 314
 315 int
 316 ccw_device_set_online(struct ccw_device *cdev)
 317 {
 318         int ret;
 319
 320         if (!cdev)
 321                 return -ENODEV;
 322         if (cdev->online || !cdev->drv)
 323                 return -EINVAL;
 324
 325         spin_lock_irq(cdev->ccwlock);
 326         ret = ccw_device_online(cdev);
 327         spin_unlock_irq(cdev->ccwlock);
 328         if (ret == 0)
 329                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 330         else {
 331                 pr_debug("ccw_device_online returned %d, device %s\n",
 332                          ret, cdev->dev.bus_id);
 333                 return ret;
 334         }
 335         if (cdev->private->state != DEV_STATE_ONLINE)
 336                 return -ENODEV;
 337         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 338                 cdev->online = 1;
 339                 return 0;
 340         }
 341         spin_lock_irq(cdev->ccwlock);
 342         ret = ccw_device_offline(cdev);
 343         spin_unlock_irq(cdev->ccwlock);
 344         if (ret == 0)
 345                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 346         else
 347                 pr_debug("ccw_device_offline returned %d, device %s\n",
 348                          ret, cdev->dev.bus_id);
 349         return (ret = 0) ? -ENODEV : ret;
 350 }
 351
 352 static ssize_t
 353 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 354 {
 355         struct ccw_device *cdev = to_ccwdev(dev);
 356         int i, force, ret;
 357         char *tmp;
 358
 359         if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
 360                 return -EAGAIN;
 361
 362         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 363                 atomic_set(&cdev->private->onoff, 0);
 364                 return -EINVAL;
 365         }
 366         if (!strncmp(buf, "force\n", count)) {
 367                 force = 1;
 368                 i = 1;
 369         } else {
 370                 force = 0;
 371                 i = simple_strtoul(buf, &tmp, 16);
 372         }
 373         if (i == 1) {
 374                 /* Do device recognition, if needed. */
 375                 if (cdev->id.cu_type == 0) {
 376                         ret = ccw_device_recognition(cdev);
 377                         if (ret) {
 378                                 printk(KERN_WARNING"Couldn't start recognition "
 379                                        "for device %s (ret=%d)\n",
 380                                        cdev->dev.bus_id, ret);
 381                                 goto out;
 382                         }
 383                         wait_event(cdev->private->wait_q,
 384                                    cdev->private->flags.recog_done);
 385                 }
 386                 if (cdev->drv && cdev->drv->set_online)
 387                         ccw_device_set_online(cdev);
 388         } else if (i == 0) {
 389                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 390                         ccw_device_remove_disconnected(cdev);
 391                 else if (cdev->drv && cdev->drv->set_offline)
 392                         ccw_device_set_offline(cdev);
 393         }
 394         if (force && cdev->private->state == DEV_STATE_BOXED) {
 395                 ret = ccw_device_stlck(cdev);
 396                 if (ret) {
 397                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 398                                "returned %d!\n", cdev->dev.bus_id, ret);
 399                         goto out;
 400                 }
 401                 /* Do device recognition, if needed. */
 402                 if (cdev->id.cu_type == 0) {
 403                         cdev->private->state = DEV_STATE_NOT_OPER;
 404                         ret = ccw_device_recognition(cdev);
 405                         if (ret) {
 406                                 printk(KERN_WARNING"Couldn't start recognition "
 407                                        "for device %s (ret=%d)\n",
 408                                        cdev->dev.bus_id, ret);
 409                                 goto out;
 410                         }
 411                         wait_event(cdev->private->wait_q,
 412                                    cdev->private->flags.recog_done);
 413                 }
 414                 if (cdev->drv && cdev->drv->set_online)
 415                         ccw_device_set_online(cdev);
 416         }
 417         out:
 418         if (cdev->drv)
 419                 module_put(cdev->drv->owner);
 420         atomic_set(&cdev->private->onoff, 0);
 421         return count;
 422 }
 423
 424 static ssize_t
 425 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 426 {
 427         struct ccw_device *cdev = to_ccwdev(dev);
 428         struct subchannel *sch;
 429
 430         switch (cdev->private->state) {
 431         case DEV_STATE_BOXED:
 432                 return sprintf(buf, "boxed\n");
 433         case DEV_STATE_DISCONNECTED:
 434         case DEV_STATE_DISCONNECTED_SENSE_ID:
 435         case DEV_STATE_NOT_OPER:
 436                 sch = to_subchannel(dev->parent);
 437                 if (!sch->lpm)
 438                         return sprintf(buf, "no path\n");
 439                 else
 440                         return sprintf(buf, "no device\n");
 441         default:
 442                 /* All other states considered fine. */
 443                 return sprintf(buf, "good\n");
 444         }
 445 }
 446
 447 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 448 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 449 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 450 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 451 static DEVICE_ATTR(online, 0644, online_show, online_store);
 452 extern struct device_attribute dev_attr_cmb_enable;
 453 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 454
 455 static struct attribute * subch_attrs[] = {
 456         &dev_attr_chpids.attr,
 457         &dev_attr_pimpampom.attr,
 458         NULL,
 459 };
 460
 461 static struct attribute_group subch_attr_group = {
 462         .attrs = subch_attrs,
 463 };
 464
 465 static inline int
 466 subchannel_add_files (struct device *dev)
 467 {
 468         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 469 }
 470
 471 static struct attribute * ccwdev_attrs[] = {
 472         &dev_attr_devtype.attr,
 473         &dev_attr_cutype.attr,
 474         &dev_attr_online.attr,
 475         &dev_attr_cmb_enable.attr,
 476         &dev_attr_availability.attr,
 477         NULL,
 478 };
 479
 480 static struct attribute_group ccwdev_attr_group = {
 481         .attrs = ccwdev_attrs,
 482 };
 483
 484 static inline int
 485 device_add_files (struct device *dev)
 486 {
 487         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 488 }
 489
 490 static inline void
 491 device_remove_files(struct device *dev)
 492 {
 493         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 494 }
 495
 496 /* this is a simple abstraction for device_register that sets the
 497  * correct bus type and adds the bus specific files */
 498 int
 499 ccw_device_register(struct ccw_device *cdev)
 500 {
 501         struct device *dev = &cdev->dev;
 502         int ret;
 503
 504         dev->bus = &ccw_bus_type;
 505
 506         if ((ret = device_add(dev)))
 507                 return ret;
 508
 509         set_bit(1, &cdev->private->registered);
 510         if ((ret = device_add_files(dev))) {
 511                 if (test_and_clear_bit(1, &cdev->private->registered))
 512                         device_del(dev);
 513         }
 514         return ret;
 515 }
 516
 517 struct match_data {
 518         unsigned int  devno;
 519         struct ccw_device * sibling;
 520 };
 521
 522 static int
 523 match_devno(struct device * dev, void * data)
 524 {
 525         struct match_data * d = (struct match_data *)data;
 526         struct ccw_device * cdev;
 527
 528         cdev = to_ccwdev(dev);
 529         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 530             (cdev->private->devno == d->devno) &&
 531             (cdev != d->sibling)) {
 532                 cdev->private->state = DEV_STATE_NOT_OPER;
 533                 return 1;
 534         }
 535         return 0;
 536 }
 537
 538 static struct ccw_device *
 539 get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
 540 {
 541         struct device *dev;
 542         struct match_data data = {
 543                 .devno  = devno,
 544                 .sibling = sibling,
 545         };
 546
 547         dev = bus_find_device(&css_bus_type, NULL, &data, match_devno);
 548
 549         return dev ? to_ccwdev(dev) : NULL;
 550 }
 551
 552 static void
 553 ccw_device_add_changed(void *data)
 554 {
 555
 556         struct ccw_device *cdev;
 557
 558         cdev = (struct ccw_device *)data;
 559         if (device_add(&cdev->dev)) {
 560                 put_device(&cdev->dev);
 561                 return;
 562         }
 563         set_bit(1, &cdev->private->registered);
 564         if (device_add_files(&cdev->dev)) {
 565                 if (test_and_clear_bit(1, &cdev->private->registered))
 566                         device_unregister(&cdev->dev);
 567         }
 568 }
 569
 570 extern int css_get_ssd_info(struct subchannel *sch);
 571
 572 void
 573 ccw_device_do_unreg_rereg(void *data)
 574 {
 575         struct ccw_device *cdev;
 576         struct subchannel *sch;
 577         int need_rename;
 578
 579         cdev = (struct ccw_device *)data;
 580         sch = to_subchannel(cdev->dev.parent);
 581         if (cdev->private->devno != sch->schib.pmcw.dev) {
 582                 /*
 583                  * The device number has changed. This is usually only when
 584                  * a device has been detached under VM and then re-appeared
 585                  * on another subchannel because of a different attachment
 586                  * order than before. Ideally, we should should just switch
 587                  * subchannels, but unfortunately, this is not possible with
 588                  * the current implementation.
 589                  * Instead, we search for the old subchannel for this device
 590                  * number and deregister so there are no collisions with the
 591                  * newly registered ccw_device.
 592                  * FIXME: Find another solution so the block layer doesn't
 593                  *        get possibly sick...
 594                  */
 595                 struct ccw_device *other_cdev;
 596
 597                 need_rename = 1;
 598                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 599                                                       cdev);
 600                 if (other_cdev) {
 601                         struct subchannel *other_sch;
 602
 603                         other_sch = to_subchannel(other_cdev->dev.parent);
 604                         if (get_device(&other_sch->dev)) {
 605                                 stsch(other_sch->irq, &other_sch->schib);
 606                                 if (other_sch->schib.pmcw.dnv) {
 607                                         other_sch->schib.pmcw.intparm = 0;
 608                                         cio_modify(other_sch);
 609                                 }
 610                                 device_unregister(&other_sch->dev);
 611                         }
 612                 }
 613                 /* Update ssd info here. */
 614                 css_get_ssd_info(sch);
 615                 cdev->private->devno = sch->schib.pmcw.dev;
 616         } else
 617                 need_rename = 0;
 618         device_remove_files(&cdev->dev);
 619         if (test_and_clear_bit(1, &cdev->private->registered))
 620                 device_del(&cdev->dev);
 621         if (need_rename)
 622                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 623                           sch->schib.pmcw.dev);
 624         PREPARE_WORK(&cdev->private->kick_work,
 625                      ccw_device_add_changed, (void *)cdev);
 626         queue_work(ccw_device_work, &cdev->private->kick_work);
 627 }
 628
 629 static void
 630 ccw_device_release(struct device *dev)
 631 {
 632         struct ccw_device *cdev;
 633
 634         cdev = to_ccwdev(dev);
 635         kfree(cdev->private);
 636         kfree(cdev);
 637 }
 638
 639 /*
 640  * Register recognized device.
 641  */
 642 static void
 643 io_subchannel_register(void *data)
 644 {
 645         struct ccw_device *cdev;
 646         struct subchannel *sch;
 647         int ret;
 648         unsigned long flags;
 649
 650         cdev = (struct ccw_device *) data;
 651         sch = to_subchannel(cdev->dev.parent);
 652
 653         if (klist_node_attached(&cdev->dev.knode_parent)) {
 654                 bus_rescan_devices(&ccw_bus_type);
 655                 goto out;
 656         }
 657         /* make it known to the system */
 658         ret = ccw_device_register(cdev);
 659         if (ret) {
 660                 printk (KERN_WARNING "%s: could not register %s\n",
 661                         __func__, cdev->dev.bus_id);
 662                 put_device(&cdev->dev);
 663                 spin_lock_irqsave(&sch->lock, flags);
 664                 sch->dev.driver_data = NULL;
 665                 spin_unlock_irqrestore(&sch->lock, flags);
 666                 kfree (cdev->private);
 667                 kfree (cdev);
 668                 put_device(&sch->dev);
 669                 if (atomic_dec_and_test(&ccw_device_init_count))
 670                         wake_up(&ccw_device_init_wq);
 671                 return;
 672         }
 673
 674         ret = subchannel_add_files(cdev->dev.parent);
 675         if (ret)
 676                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 677                        __func__, sch->dev.bus_id);
 678         put_device(&cdev->dev);
 679 out:
 680         cdev->private->flags.recog_done = 1;
 681         put_device(&sch->dev);
 682         wake_up(&cdev->private->wait_q);
 683         if (atomic_dec_and_test(&ccw_device_init_count))
 684                 wake_up(&ccw_device_init_wq);
 685 }
 686
 687 void
 688 ccw_device_call_sch_unregister(void *data)
 689 {
 690         struct ccw_device *cdev = data;
 691         struct subchannel *sch;
 692
 693         sch = to_subchannel(cdev->dev.parent);
 694         device_unregister(&sch->dev);
 695         /* Reset intparm to zeroes. */
 696         sch->schib.pmcw.intparm = 0;
 697         cio_modify(sch);
 698         put_device(&cdev->dev);
 699         put_device(&sch->dev);
 700 }
 701
 702 /*
 703  * subchannel recognition done. Called from the state machine.
 704  */
 705 void
 706 io_subchannel_recog_done(struct ccw_device *cdev)
 707 {
 708         struct subchannel *sch;
 709
 710         if (css_init_done == 0) {
 711                 cdev->private->flags.recog_done = 1;
 712                 return;
 713         }
 714         switch (cdev->private->state) {
 715         case DEV_STATE_NOT_OPER:
 716                 cdev->private->flags.recog_done = 1;
 717                 /* Remove device found not operational. */
 718                 if (!get_device(&cdev->dev))
 719                         break;
 720                 sch = to_subchannel(cdev->dev.parent);
 721                 PREPARE_WORK(&cdev->private->kick_work,
 722                              ccw_device_call_sch_unregister, (void *) cdev);
 723                 queue_work(slow_path_wq, &cdev->private->kick_work);
 724                 if (atomic_dec_and_test(&ccw_device_init_count))
 725                         wake_up(&ccw_device_init_wq);
 726                 break;
 727         case DEV_STATE_BOXED:
 728                 /* Device did not respond in time. */
 729         case DEV_STATE_OFFLINE:
 730                 /*
 731                  * We can't register the device in interrupt context so
 732                  * we schedule a work item.
 733                  */
 734                 if (!get_device(&cdev->dev))
 735                         break;
 736                 PREPARE_WORK(&cdev->private->kick_work,
 737                              io_subchannel_register, (void *) cdev);
 738                 queue_work(slow_path_wq, &cdev->private->kick_work);
 739                 break;
 740         }
 741 }
 742
 743 static int
 744 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 745 {
 746         int rc;
 747         struct ccw_device_private *priv;
 748
 749         sch->dev.driver_data = cdev;
 750         sch->driver = &io_subchannel_driver;
 751         cdev->ccwlock = &sch->lock;
 752         /* Init private data. */
 753         priv = cdev->private;
 754         priv->devno = sch->schib.pmcw.dev;
 755         priv->irq = sch->irq;
 756         priv->state = DEV_STATE_NOT_OPER;
 757         INIT_LIST_HEAD(&priv->cmb_list);
 758         init_waitqueue_head(&priv->wait_q);
 759         init_timer(&priv->timer);
 760
 761         /* Set an initial name for the device. */
 762         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 763                   sch->schib.pmcw.dev);
 764
 765         /* Increase counter of devices currently in recognition. */
 766         atomic_inc(&ccw_device_init_count);
 767
 768         /* Start async. device sensing. */
 769         spin_lock_irq(&sch->lock);
 770         rc = ccw_device_recognition(cdev);
 771         spin_unlock_irq(&sch->lock);
 772         if (rc) {
 773                 if (atomic_dec_and_test(&ccw_device_init_count))
 774                         wake_up(&ccw_device_init_wq);
 775         }
 776         return rc;
 777 }
 778
 779 static int
 780 io_subchannel_probe (struct device *pdev)
 781 {
 782         struct subchannel *sch;
 783         struct ccw_device *cdev;
 784         int rc;
 785         unsigned long flags;
 786
 787         sch = to_subchannel(pdev);
 788         if (sch->dev.driver_data) {
 789                 /*
 790                  * This subchannel already has an associated ccw_device.
 791                  * Register it and exit. This happens for all early
 792                  * device, e.g. the console.
 793                  */
 794                 cdev = sch->dev.driver_data;
 795                 device_initialize(&cdev->dev);
 796                 ccw_device_register(cdev);
 797                 subchannel_add_files(&sch->dev);
 798                 /*
 799                  * Check if the device is already online. If it is
 800                  * the reference count needs to be corrected
 801                  * (see ccw_device_online and css_init_done for the
 802                  * ugly details).
 803                  */
 804                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 805                     cdev->private->state != DEV_STATE_OFFLINE &&
 806                     cdev->private->state != DEV_STATE_BOXED)
 807                         get_device(&cdev->dev);
 808                 return 0;
 809         }
 810         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 811         if (!cdev)
 812                 return -ENOMEM;
 813         memset(cdev, 0, sizeof(struct ccw_device));
 814         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 815                                 GFP_KERNEL | GFP_DMA);
 816         if (!cdev->private) {
 817                 kfree(cdev);
 818                 return -ENOMEM;
 819         }
 820         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 821         atomic_set(&cdev->private->onoff, 0);
 822         cdev->dev = (struct device) {
 823                 .parent = pdev,
 824                 .release = ccw_device_release,
 825         };
 826         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 827         /* Do first half of device_register. */
 828         device_initialize(&cdev->dev);
 829
 830         if (!get_device(&sch->dev)) {
 831                 if (cdev->dev.release)
 832                         cdev->dev.release(&cdev->dev);
 833                 return -ENODEV;
 834         }
 835
 836         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 837         if (rc) {
 838                 spin_lock_irqsave(&sch->lock, flags);
 839                 sch->dev.driver_data = NULL;
 840                 spin_unlock_irqrestore(&sch->lock, flags);
 841                 if (cdev->dev.release)
 842                         cdev->dev.release(&cdev->dev);
 843         }
 844
 845         return rc;
 846 }
 847
 848 static void
 849 ccw_device_unregister(void *data)
 850 {
 851         struct ccw_device *cdev;
 852
 853         cdev = (struct ccw_device *)data;
 854         if (test_and_clear_bit(1, &cdev->private->registered))
 855                 device_unregister(&cdev->dev);
 856         put_device(&cdev->dev);
 857 }
 858
 859 static int
 860 io_subchannel_remove (struct device *dev)
 861 {
 862         struct ccw_device *cdev;
 863         unsigned long flags;
 864
 865         if (!dev->driver_data)
 866                 return 0;
 867         cdev = dev->driver_data;
 868         /* Set ccw device to not operational and drop reference. */
 869         spin_lock_irqsave(cdev->ccwlock, flags);
 870         dev->driver_data = NULL;
 871         cdev->private->state = DEV_STATE_NOT_OPER;
 872         spin_unlock_irqrestore(cdev->ccwlock, flags);
 873         /*
 874          * Put unregistration on workqueue to avoid livelocks on the css bus
 875          * semaphore.
 876          */
 877         if (get_device(&cdev->dev)) {
 878                 PREPARE_WORK(&cdev->private->kick_work,
 879                              ccw_device_unregister, (void *) cdev);
 880                 queue_work(ccw_device_work, &cdev->private->kick_work);
 881         }
 882         return 0;
 883 }
 884
 885 static int
 886 io_subchannel_notify(struct device *dev, int event)
 887 {
 888         struct ccw_device *cdev;
 889
 890         cdev = dev->driver_data;
 891         if (!cdev)
 892                 return 0;
 893         if (!cdev->drv)
 894                 return 0;
 895         if (!cdev->online)
 896                 return 0;
 897         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 898 }
 899
 900 static void
 901 io_subchannel_verify(struct device *dev)
 902 {
 903         struct ccw_device *cdev;
 904
 905         cdev = dev->driver_data;
 906         if (cdev)
 907                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 908 }
 909
 910 static void
 911 io_subchannel_ioterm(struct device *dev)
 912 {
 913         struct ccw_device *cdev;
 914
 915         cdev = dev->driver_data;
 916         if (!cdev)
 917                 return;
 918         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 919         if (cdev->handler)
 920                 cdev->handler(cdev, cdev->private->intparm,
 921                               ERR_PTR(-EIO));
 922 }
 923
 924 static void
 925 io_subchannel_shutdown(struct device *dev)
 926 {
 927         struct subchannel *sch;
 928         struct ccw_device *cdev;
 929         int ret;
 930
 931         sch = to_subchannel(dev);
 932         cdev = dev->driver_data;
 933
 934         if (cio_is_console(sch->irq))
 935                 return;
 936         if (!sch->schib.pmcw.ena)
 937                 /* Nothing to do. */
 938                 return;
 939         ret = cio_disable_subchannel(sch);
 940         if (ret != -EBUSY)
 941                 /* Subchannel is disabled, we're done. */
 942                 return;
 943         cdev->private->state = DEV_STATE_QUIESCE;
 944         if (cdev->handler)
 945                 cdev->handler(cdev, cdev->private->intparm,
 946                               ERR_PTR(-EIO));
 947         ret = ccw_device_cancel_halt_clear(cdev);
 948         if (ret == -EBUSY) {
 949                 ccw_device_set_timeout(cdev, HZ/10);
 950                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 951         }
 952         cio_disable_subchannel(sch);
 953 }
 954
 955 #ifdef CONFIG_CCW_CONSOLE
 956 static struct ccw_device console_cdev;
 957 static struct ccw_device_private console_private;
 958 static int console_cdev_in_use;
 959
 960 static int
 961 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 962 {
 963         int rc;
 964
 965         /* Initialize the ccw_device structure. */
 966         cdev->dev = (struct device) {
 967                 .parent = &sch->dev,
 968         };
 969         /* Initialize the subchannel structure */
 970         sch->dev.parent = &css_bus_device;
 971         sch->dev.bus = &css_bus_type;
 972
 973         rc = io_subchannel_recog(cdev, sch);
 974         if (rc)
 975                 return rc;
 976
 977         /* Now wait for the async. recognition to come to an end. */
 978         spin_lock_irq(cdev->ccwlock);
 979         while (!dev_fsm_final_state(cdev))
 980                 wait_cons_dev();
 981         rc = -EIO;
 982         if (cdev->private->state != DEV_STATE_OFFLINE)
 983                 goto out_unlock;
 984         ccw_device_online(cdev);
 985         while (!dev_fsm_final_state(cdev))
 986                 wait_cons_dev();
 987         if (cdev->private->state != DEV_STATE_ONLINE)
 988                 goto out_unlock;
 989         rc = 0;
 990 out_unlock:
 991         spin_unlock_irq(cdev->ccwlock);
 992         return 0;
 993 }
 994
 995 struct ccw_device *
 996 ccw_device_probe_console(void)
 997 {
 998         struct subchannel *sch;
 999         int ret;
1000
1001         if (xchg(&console_cdev_in_use, 1) != 0)
1002                 return NULL;
1003         sch = cio_probe_console();
1004         if (IS_ERR(sch)) {
1005                 console_cdev_in_use = 0;
1006                 return (void *) sch;
1007         }
1008         memset(&console_cdev, 0, sizeof(struct ccw_device));
1009         memset(&console_private, 0, sizeof(struct ccw_device_private));
1010         console_cdev.private = &console_private;
1011         ret = ccw_device_console_enable(&console_cdev, sch);
1012         if (ret) {
1013                 cio_release_console();
1014                 console_cdev_in_use = 0;
1015                 return ERR_PTR(ret);
1016         }
1017         console_cdev.online = 1;
1018         return &console_cdev;
1019 }
1020 #endif
1021
1022 /*
1023  * get ccw_device matching the busid, but only if owned by cdrv
1024  */
1025 static int
1026 __ccwdev_check_busid(struct device *dev, void *id)
1027 {
1028         char *bus_id;
1029
1030         bus_id = (char *)id;
1031
1032         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1033 }
1034
1035
1036 struct ccw_device *
1037 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1038 {
1039         struct device *dev;
1040         struct device_driver *drv;
1041
1042         drv = get_driver(&cdrv->driver);
1043         if (!drv)
1044                 return NULL;
1045
1046         dev = driver_find_device(drv, NULL, (void *)bus_id,
1047                                  __ccwdev_check_busid);
1048         put_driver(drv);
1049
1050         return dev ? to_ccwdev(dev) : 0;
1051 }
1052
1053 /************************** device driver handling ************************/
1054
1055 /* This is the implementation of the ccw_driver class. The probe, remove
1056  * and release methods are initially very similar to the device_driver
1057  * implementations, with the difference that they have ccw_device
1058  * arguments.
1059  *
1060  * A ccw driver also contains the information that is needed for
1061  * device matching.
1062  */
1063 static int
1064 ccw_device_probe (struct device *dev)
1065 {
1066         struct ccw_device *cdev = to_ccwdev(dev);
1067         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1068         int ret;
1069
1070         cdev->drv = cdrv; /* to let the driver call _set_online */
1071
1072         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1073
1074         if (ret) {
1075                 cdev->drv = 0;
1076                 return ret;
1077         }
1078
1079         return 0;
1080 }
1081
1082 static int
1083 ccw_device_remove (struct device *dev)
1084 {
1085         struct ccw_device *cdev = to_ccwdev(dev);
1086         struct ccw_driver *cdrv = cdev->drv;
1087         int ret;
1088
1089         pr_debug("removing device %s\n", cdev->dev.bus_id);
1090         if (cdrv->remove)
1091                 cdrv->remove(cdev);
1092         if (cdev->online) {
1093                 cdev->online = 0;
1094                 spin_lock_irq(cdev->ccwlock);
1095                 ret = ccw_device_offline(cdev);
1096                 spin_unlock_irq(cdev->ccwlock);
1097                 if (ret == 0)
1098                         wait_event(cdev->private->wait_q,
1099                                    dev_fsm_final_state(cdev));
1100                 else
1101                         //FIXME: we can't fail!
1102                         pr_debug("ccw_device_offline returned %d, device %s\n",
1103                                  ret, cdev->dev.bus_id);
1104         }
1105         ccw_device_set_timeout(cdev, 0);
1106         cdev->drv = 0;
1107         return 0;
1108 }
1109
1110 int
1111 ccw_driver_register (struct ccw_driver *cdriver)
1112 {
1113         struct device_driver *drv = &cdriver->driver;
1114
1115         drv->bus = &ccw_bus_type;
1116         drv->name = cdriver->name;
1117         drv->probe = ccw_device_probe;
1118         drv->remove = ccw_device_remove;
1119
1120         return driver_register(drv);
1121 }
1122
1123 void
1124 ccw_driver_unregister (struct ccw_driver *cdriver)
1125 {
1126         driver_unregister(&cdriver->driver);
1127 }
1128
1129 MODULE_LICENSE("GPL");
1130 EXPORT_SYMBOL(ccw_device_set_online);
1131 EXPORT_SYMBOL(ccw_device_set_offline);
1132 EXPORT_SYMBOL(ccw_driver_register);
1133 EXPORT_SYMBOL(ccw_driver_unregister);
1134 EXPORT_SYMBOL(get_ccwdev_by_busid);
1135 EXPORT_SYMBOL(ccw_bus_type);
1136 EXPORT_SYMBOL(ccw_device_work);
1137 EXPORT_SYMBOL(ccw_device_notify_work);