drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002,2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/errno.h>
  14 #include <linux/err.h>
  15 #include <linux/slab.h>
  16 #include <linux/list.h>
  17 #include <linux/device.h>
  18 #include <linux/workqueue.h>
  19 #include <linux/timer.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24 #include <asm/cmb.h>
  25 #include <asm/isc.h>
  26
  27 #include "chp.h"
  28 #include "cio.h"
  29 #include "cio_debug.h"
  30 #include "css.h"
  31 #include "device.h"
  32 #include "ioasm.h"
  33 #include "io_sch.h"
  34 #include "blacklist.h"
  35
  36 static struct timer_list recovery_timer;
  37 static DEFINE_SPINLOCK(recovery_lock);
  38 static int recovery_phase;
  39 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  40
  41 /******************* bus type handling ***********************/
  42
  43 /* The Linux driver model distinguishes between a bus type and
  44  * the bus itself. Of course we only have one channel
  45  * subsystem driver and one channel system per machine, but
  46  * we still use the abstraction. T.R. says it's a good idea. */
  47 static int
  48 ccw_bus_match (struct device * dev, struct device_driver * drv)
  49 {
  50         struct ccw_device *cdev = to_ccwdev(dev);
  51         struct ccw_driver *cdrv = to_ccwdrv(drv);
  52         const struct ccw_device_id *ids = cdrv->ids, *found;
  53
  54         if (!ids)
  55                 return 0;
  56
  57         found = ccw_device_id_match(ids, &cdev->id);
  58         if (!found)
  59                 return 0;
  60
  61         cdev->id.driver_info = found->driver_info;
  62
  63         return 1;
  64 }
  65
  66 /* Store modalias string delimited by prefix/suffix string into buffer with
  67  * specified size. Return length of resulting string (excluding trailing '\0')
  68  * even if string doesn't fit buffer (snprintf semantics). */
  69 static int snprint_alias(char *buf, size_t size,
  70                          struct ccw_device_id *id, const char *suffix)
  71 {
  72         int len;
  73
  74         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  75         if (len > size)
  76                 return len;
  77         buf += len;
  78         size -= len;
  79
  80         if (id->dev_type != 0)
  81                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  82                                 id->dev_model, suffix);
  83         else
  84                 len += snprintf(buf, size, "dtdm%s", suffix);
  85
  86         return len;
  87 }
  88
  89 /* Set up environment variables for ccw device uevent. Return 0 on success,
  90  * non-zero otherwise. */
  91 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  92 {
  93         struct ccw_device *cdev = to_ccwdev(dev);
  94         struct ccw_device_id *id = &(cdev->id);
  95         int ret;
  96         char modalias_buf[30];
  97
  98         /* CU_TYPE= */
  99         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 100         if (ret)
 101                 return ret;
 102
 103         /* CU_MODEL= */
 104         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 105         if (ret)
 106                 return ret;
 107
 108         /* The next two can be zero, that's ok for us */
 109         /* DEV_TYPE= */
 110         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 111         if (ret)
 112                 return ret;
 113
 114         /* DEV_MODEL= */
 115         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 116         if (ret)
 117                 return ret;
 118
 119         /* MODALIAS=  */
 120         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 121         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 122         return ret;
 123 }
 124
 125 struct bus_type ccw_bus_type;
 126
 127 static void io_subchannel_irq(struct subchannel *);
 128 static int io_subchannel_probe(struct subchannel *);
 129 static int io_subchannel_remove(struct subchannel *);
 130 static void io_subchannel_shutdown(struct subchannel *);
 131 static int io_subchannel_sch_event(struct subchannel *, int);
 132 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 133                                    int);
 134
 135 static struct css_device_id io_subchannel_ids[] = {
 136         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 137         { /* end of list */ },
 138 };
 139 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 140
 141 static struct css_driver io_subchannel_driver = {
 142         .owner = THIS_MODULE,
 143         .subchannel_type = io_subchannel_ids,
 144         .name = "io_subchannel",
 145         .irq = io_subchannel_irq,
 146         .sch_event = io_subchannel_sch_event,
 147         .chp_event = io_subchannel_chp_event,
 148         .probe = io_subchannel_probe,
 149         .remove = io_subchannel_remove,
 150         .shutdown = io_subchannel_shutdown,
 151 };
 152
 153 struct workqueue_struct *ccw_device_work;
 154 wait_queue_head_t ccw_device_init_wq;
 155 atomic_t ccw_device_init_count;
 156
 157 static void recovery_func(unsigned long data);
 158
 159 static int __init
 160 init_ccw_bus_type (void)
 161 {
 162         int ret;
 163
 164         init_waitqueue_head(&ccw_device_init_wq);
 165         atomic_set(&ccw_device_init_count, 0);
 166         setup_timer(&recovery_timer, recovery_func, 0);
 167
 168         ccw_device_work = create_singlethread_workqueue("cio");
 169         if (!ccw_device_work)
 170                 return -ENOMEM; /* FIXME: better errno ? */
 171         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 172         if (!slow_path_wq) {
 173                 ret = -ENOMEM; /* FIXME: better errno ? */
 174                 goto out_err;
 175         }
 176         if ((ret = bus_register (&ccw_bus_type)))
 177                 goto out_err;
 178
 179         ret = css_driver_register(&io_subchannel_driver);
 180         if (ret)
 181                 goto out_err;
 182
 183         wait_event(ccw_device_init_wq,
 184                    atomic_read(&ccw_device_init_count) == 0);
 185         flush_workqueue(ccw_device_work);
 186         return 0;
 187 out_err:
 188         if (ccw_device_work)
 189                 destroy_workqueue(ccw_device_work);
 190         if (slow_path_wq)
 191                 destroy_workqueue(slow_path_wq);
 192         return ret;
 193 }
 194
 195 static void __exit
 196 cleanup_ccw_bus_type (void)
 197 {
 198         css_driver_unregister(&io_subchannel_driver);
 199         bus_unregister(&ccw_bus_type);
 200         destroy_workqueue(ccw_device_work);
 201 }
 202
 203 subsys_initcall(init_ccw_bus_type);
 204 module_exit(cleanup_ccw_bus_type);
 205
 206 /************************ device handling **************************/
 207
 208 /*
 209  * A ccw_device has some interfaces in sysfs in addition to the
 210  * standard ones.
 211  * The following entries are designed to export the information which
 212  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 213  * are obvious, so they don't have an entry :)
 214  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 215  */
 216 static ssize_t
 217 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 218 {
 219         struct subchannel *sch = to_subchannel(dev);
 220         struct chsc_ssd_info *ssd = &sch->ssd_info;
 221         ssize_t ret = 0;
 222         int chp;
 223         int mask;
 224
 225         for (chp = 0; chp < 8; chp++) {
 226                 mask = 0x80 >> chp;
 227                 if (ssd->path_mask & mask)
 228                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 229                 else
 230                         ret += sprintf(buf + ret, "00 ");
 231         }
 232         ret += sprintf (buf+ret, "\n");
 233         return min((ssize_t)PAGE_SIZE, ret);
 234 }
 235
 236 static ssize_t
 237 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 238 {
 239         struct subchannel *sch = to_subchannel(dev);
 240         struct pmcw *pmcw = &sch->schib.pmcw;
 241
 242         return sprintf (buf, "%02x %02x %02x\n",
 243                         pmcw->pim, pmcw->pam, pmcw->pom);
 244 }
 245
 246 static ssize_t
 247 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 248 {
 249         struct ccw_device *cdev = to_ccwdev(dev);
 250         struct ccw_device_id *id = &(cdev->id);
 251
 252         if (id->dev_type != 0)
 253                 return sprintf(buf, "%04x/%02x\n",
 254                                 id->dev_type, id->dev_model);
 255         else
 256                 return sprintf(buf, "n/a\n");
 257 }
 258
 259 static ssize_t
 260 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 261 {
 262         struct ccw_device *cdev = to_ccwdev(dev);
 263         struct ccw_device_id *id = &(cdev->id);
 264
 265         return sprintf(buf, "%04x/%02x\n",
 266                        id->cu_type, id->cu_model);
 267 }
 268
 269 static ssize_t
 270 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 271 {
 272         struct ccw_device *cdev = to_ccwdev(dev);
 273         struct ccw_device_id *id = &(cdev->id);
 274         int len;
 275
 276         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 277
 278         return len > PAGE_SIZE ? PAGE_SIZE : len;
 279 }
 280
 281 static ssize_t
 282 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 283 {
 284         struct ccw_device *cdev = to_ccwdev(dev);
 285
 286         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 287 }
 288
 289 int ccw_device_is_orphan(struct ccw_device *cdev)
 290 {
 291         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 292 }
 293
 294 static void ccw_device_unregister(struct ccw_device *cdev)
 295 {
 296         if (test_and_clear_bit(1, &cdev->private->registered))
 297                 device_del(&cdev->dev);
 298 }
 299
 300 static void ccw_device_remove_orphan_cb(struct work_struct *work)
 301 {
 302         struct ccw_device_private *priv;
 303         struct ccw_device *cdev;
 304
 305         priv = container_of(work, struct ccw_device_private, kick_work);
 306         cdev = priv->cdev;
 307         ccw_device_unregister(cdev);
 308         put_device(&cdev->dev);
 309         /* Release cdev reference for workqueue processing. */
 310         put_device(&cdev->dev);
 311 }
 312
 313 static void
 314 ccw_device_remove_disconnected(struct ccw_device *cdev)
 315 {
 316         unsigned long flags;
 317
 318         /*
 319          * Forced offline in disconnected state means
 320          * 'throw away device'.
 321          */
 322         /* Get cdev reference for workqueue processing. */
 323         if (!get_device(&cdev->dev))
 324                 return;
 325         if (ccw_device_is_orphan(cdev)) {
 326                 /*
 327                  * Deregister ccw device.
 328                  * Unfortunately, we cannot do this directly from the
 329                  * attribute method.
 330                  */
 331                 spin_lock_irqsave(cdev->ccwlock, flags);
 332                 cdev->private->state = DEV_STATE_NOT_OPER;
 333                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 334                 PREPARE_WORK(&cdev->private->kick_work,
 335                                 ccw_device_remove_orphan_cb);
 336                 queue_work(slow_path_wq, &cdev->private->kick_work);
 337         } else
 338                 /* Deregister subchannel, which will kill the ccw device. */
 339                 ccw_device_schedule_sch_unregister(cdev);
 340 }
 341
 342 /**
 343  * ccw_device_set_offline() - disable a ccw device for I/O
 344  * @cdev: target ccw device
 345  *
 346  * This function calls the driver's set_offline() function for @cdev, if
 347  * given, and then disables @cdev.
 348  * Returns:
 349  *   %0 on success and a negative error value on failure.
 350  * Context:
 351  *  enabled, ccw device lock not held
 352  */
 353 int ccw_device_set_offline(struct ccw_device *cdev)
 354 {
 355         int ret;
 356
 357         if (!cdev)
 358                 return -ENODEV;
 359         if (!cdev->online || !cdev->drv)
 360                 return -EINVAL;
 361
 362         if (cdev->drv->set_offline) {
 363                 ret = cdev->drv->set_offline(cdev);
 364                 if (ret != 0)
 365                         return ret;
 366         }
 367         cdev->online = 0;
 368         spin_lock_irq(cdev->ccwlock);
 369         ret = ccw_device_offline(cdev);
 370         if (ret == -ENODEV) {
 371                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 372                         cdev->private->state = DEV_STATE_OFFLINE;
 373                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 374                 }
 375                 spin_unlock_irq(cdev->ccwlock);
 376                 /* Give up reference from ccw_device_set_online(). */
 377                 put_device(&cdev->dev);
 378                 return ret;
 379         }
 380         spin_unlock_irq(cdev->ccwlock);
 381         if (ret == 0) {
 382                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 383                 /* Give up reference from ccw_device_set_online(). */
 384                 put_device(&cdev->dev);
 385         } else {
 386                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 387                               "device 0.%x.%04x\n",
 388                               ret, cdev->private->dev_id.ssid,
 389                               cdev->private->dev_id.devno);
 390                 cdev->online = 1;
 391         }
 392         return ret;
 393 }
 394
 395 /**
 396  * ccw_device_set_online() - enable a ccw device for I/O
 397  * @cdev: target ccw device
 398  *
 399  * This function first enables @cdev and then calls the driver's set_online()
 400  * function for @cdev, if given. If set_online() returns an error, @cdev is
 401  * disabled again.
 402  * Returns:
 403  *   %0 on success and a negative error value on failure.
 404  * Context:
 405  *  enabled, ccw device lock not held
 406  */
 407 int ccw_device_set_online(struct ccw_device *cdev)
 408 {
 409         int ret;
 410
 411         if (!cdev)
 412                 return -ENODEV;
 413         if (cdev->online || !cdev->drv)
 414                 return -EINVAL;
 415         /* Hold on to an extra reference while device is online. */
 416         if (!get_device(&cdev->dev))
 417                 return -ENODEV;
 418
 419         spin_lock_irq(cdev->ccwlock);
 420         ret = ccw_device_online(cdev);
 421         spin_unlock_irq(cdev->ccwlock);
 422         if (ret == 0)
 423                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 424         else {
 425                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 426                               "device 0.%x.%04x\n",
 427                               ret, cdev->private->dev_id.ssid,
 428                               cdev->private->dev_id.devno);
 429                 /* Give up online reference since onlining failed. */
 430                 put_device(&cdev->dev);
 431                 return ret;
 432         }
 433         if (cdev->private->state != DEV_STATE_ONLINE) {
 434                 /* Give up online reference since onlining failed. */
 435                 put_device(&cdev->dev);
 436                 return -ENODEV;
 437         }
 438         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 439                 cdev->online = 1;
 440                 return 0;
 441         }
 442         spin_lock_irq(cdev->ccwlock);
 443         ret = ccw_device_offline(cdev);
 444         spin_unlock_irq(cdev->ccwlock);
 445         if (ret == 0)
 446                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 447         else
 448                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 449                               "device 0.%x.%04x\n",
 450                               ret, cdev->private->dev_id.ssid,
 451                               cdev->private->dev_id.devno);
 452         /* Give up online reference since onlining failed. */
 453         put_device(&cdev->dev);
 454         return (ret == 0) ? -ENODEV : ret;
 455 }
 456
 457 static int online_store_handle_offline(struct ccw_device *cdev)
 458 {
 459         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 460                 ccw_device_remove_disconnected(cdev);
 461         else if (cdev->online && cdev->drv && cdev->drv->set_offline)
 462                 return ccw_device_set_offline(cdev);
 463         return 0;
 464 }
 465
 466 static int online_store_recog_and_online(struct ccw_device *cdev)
 467 {
 468         int ret;
 469
 470         /* Do device recognition, if needed. */
 471         if (cdev->private->state == DEV_STATE_BOXED) {
 472                 ret = ccw_device_recognition(cdev);
 473                 if (ret) {
 474                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 475                                       "for device 0.%x.%04x (ret=%d)\n",
 476                                       cdev->private->dev_id.ssid,
 477                                       cdev->private->dev_id.devno, ret);
 478                         return ret;
 479                 }
 480                 wait_event(cdev->private->wait_q,
 481                            cdev->private->flags.recog_done);
 482                 if (cdev->private->state != DEV_STATE_OFFLINE)
 483                         /* recognition failed */
 484                         return -EAGAIN;
 485         }
 486         if (cdev->drv && cdev->drv->set_online)
 487                 ccw_device_set_online(cdev);
 488         return 0;
 489 }
 490
 491 static int online_store_handle_online(struct ccw_device *cdev, int force)
 492 {
 493         int ret;
 494
 495         ret = online_store_recog_and_online(cdev);
 496         if (ret && !force)
 497                 return ret;
 498         if (force && cdev->private->state == DEV_STATE_BOXED) {
 499                 ret = ccw_device_stlck(cdev);
 500                 if (ret)
 501                         return ret;
 502                 if (cdev->id.cu_type == 0)
 503                         cdev->private->state = DEV_STATE_NOT_OPER;
 504                 ret = online_store_recog_and_online(cdev);
 505                 if (ret)
 506                         return ret;
 507         }
 508         return 0;
 509 }
 510
 511 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 512                              const char *buf, size_t count)
 513 {
 514         struct ccw_device *cdev = to_ccwdev(dev);
 515         int force, ret;
 516         unsigned long i;
 517
 518         if ((cdev->private->state != DEV_STATE_OFFLINE &&
 519              cdev->private->state != DEV_STATE_ONLINE &&
 520              cdev->private->state != DEV_STATE_BOXED &&
 521              cdev->private->state != DEV_STATE_DISCONNECTED) ||
 522             atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 523                 return -EAGAIN;
 524
 525         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 526                 atomic_set(&cdev->private->onoff, 0);
 527                 return -EINVAL;
 528         }
 529         if (!strncmp(buf, "force\n", count)) {
 530                 force = 1;
 531                 i = 1;
 532                 ret = 0;
 533         } else {
 534                 force = 0;
 535                 ret = strict_strtoul(buf, 16, &i);
 536         }
 537         if (ret)
 538                 goto out;
 539         switch (i) {
 540         case 0:
 541                 ret = online_store_handle_offline(cdev);
 542                 break;
 543         case 1:
 544                 ret = online_store_handle_online(cdev, force);
 545                 break;
 546         default:
 547                 ret = -EINVAL;
 548         }
 549 out:
 550         if (cdev->drv)
 551                 module_put(cdev->drv->owner);
 552         atomic_set(&cdev->private->onoff, 0);
 553         return (ret < 0) ? ret : count;
 554 }
 555
 556 static ssize_t
 557 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 558 {
 559         struct ccw_device *cdev = to_ccwdev(dev);
 560         struct subchannel *sch;
 561
 562         if (ccw_device_is_orphan(cdev))
 563                 return sprintf(buf, "no device\n");
 564         switch (cdev->private->state) {
 565         case DEV_STATE_BOXED:
 566                 return sprintf(buf, "boxed\n");
 567         case DEV_STATE_DISCONNECTED:
 568         case DEV_STATE_DISCONNECTED_SENSE_ID:
 569         case DEV_STATE_NOT_OPER:
 570                 sch = to_subchannel(dev->parent);
 571                 if (!sch->lpm)
 572                         return sprintf(buf, "no path\n");
 573                 else
 574                         return sprintf(buf, "no device\n");
 575         default:
 576                 /* All other states considered fine. */
 577                 return sprintf(buf, "good\n");
 578         }
 579 }
 580
 581 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 582 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 583 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 584 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 585 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 586 static DEVICE_ATTR(online, 0644, online_show, online_store);
 587 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 588
 589 static struct attribute *io_subchannel_attrs[] = {
 590         &dev_attr_chpids.attr,
 591         &dev_attr_pimpampom.attr,
 592         NULL,
 593 };
 594
 595 static struct attribute_group io_subchannel_attr_group = {
 596         .attrs = io_subchannel_attrs,
 597 };
 598
 599 static struct attribute * ccwdev_attrs[] = {
 600         &dev_attr_devtype.attr,
 601         &dev_attr_cutype.attr,
 602         &dev_attr_modalias.attr,
 603         &dev_attr_online.attr,
 604         &dev_attr_cmb_enable.attr,
 605         &dev_attr_availability.attr,
 606         NULL,
 607 };
 608
 609 static struct attribute_group ccwdev_attr_group = {
 610         .attrs = ccwdev_attrs,
 611 };
 612
 613 static struct attribute_group *ccwdev_attr_groups[] = {
 614         &ccwdev_attr_group,
 615         NULL,
 616 };
 617
 618 /* this is a simple abstraction for device_register that sets the
 619  * correct bus type and adds the bus specific files */
 620 static int ccw_device_register(struct ccw_device *cdev)
 621 {
 622         struct device *dev = &cdev->dev;
 623         int ret;
 624
 625         dev->bus = &ccw_bus_type;
 626
 627         if ((ret = device_add(dev)))
 628                 return ret;
 629
 630         set_bit(1, &cdev->private->registered);
 631         return ret;
 632 }
 633
 634 struct match_data {
 635         struct ccw_dev_id dev_id;
 636         struct ccw_device * sibling;
 637 };
 638
 639 static int
 640 match_devno(struct device * dev, void * data)
 641 {
 642         struct match_data * d = data;
 643         struct ccw_device * cdev;
 644
 645         cdev = to_ccwdev(dev);
 646         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 647             !ccw_device_is_orphan(cdev) &&
 648             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 649             (cdev != d->sibling))
 650                 return 1;
 651         return 0;
 652 }
 653
 654 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 655                                                      struct ccw_device *sibling)
 656 {
 657         struct device *dev;
 658         struct match_data data;
 659
 660         data.dev_id = *dev_id;
 661         data.sibling = sibling;
 662         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 663
 664         return dev ? to_ccwdev(dev) : NULL;
 665 }
 666
 667 static int match_orphan(struct device *dev, void *data)
 668 {
 669         struct ccw_dev_id *dev_id;
 670         struct ccw_device *cdev;
 671
 672         dev_id = data;
 673         cdev = to_ccwdev(dev);
 674         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 675 }
 676
 677 static struct ccw_device *
 678 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 679                               struct ccw_dev_id *dev_id)
 680 {
 681         struct device *dev;
 682
 683         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 684                                 match_orphan);
 685
 686         return dev ? to_ccwdev(dev) : NULL;
 687 }
 688
 689 void ccw_device_do_unbind_bind(struct work_struct *work)
 690 {
 691         struct ccw_device_private *priv;
 692         struct ccw_device *cdev;
 693         struct subchannel *sch;
 694         int ret;
 695
 696         priv = container_of(work, struct ccw_device_private, kick_work);
 697         cdev = priv->cdev;
 698         sch = to_subchannel(cdev->dev.parent);
 699
 700         if (test_bit(1, &cdev->private->registered)) {
 701                 device_release_driver(&cdev->dev);
 702                 ret = device_attach(&cdev->dev);
 703                 WARN_ON(ret == -ENODEV);
 704         }
 705 }
 706
 707 static void
 708 ccw_device_release(struct device *dev)
 709 {
 710         struct ccw_device *cdev;
 711
 712         cdev = to_ccwdev(dev);
 713         /* Release reference of parent subchannel. */
 714         put_device(cdev->dev.parent);
 715         kfree(cdev->private);
 716         kfree(cdev);
 717 }
 718
 719 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 720 {
 721         struct ccw_device *cdev;
 722
 723         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 724         if (cdev) {
 725                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 726                                         GFP_KERNEL | GFP_DMA);
 727                 if (cdev->private)
 728                         return cdev;
 729         }
 730         kfree(cdev);
 731         return ERR_PTR(-ENOMEM);
 732 }
 733
 734 static int io_subchannel_initialize_dev(struct subchannel *sch,
 735                                         struct ccw_device *cdev)
 736 {
 737         cdev->private->cdev = cdev;
 738         atomic_set(&cdev->private->onoff, 0);
 739         cdev->dev.parent = &sch->dev;
 740         cdev->dev.release = ccw_device_release;
 741         INIT_WORK(&cdev->private->kick_work, NULL);
 742         cdev->dev.groups = ccwdev_attr_groups;
 743         /* Do first half of device_register. */
 744         device_initialize(&cdev->dev);
 745         if (!get_device(&sch->dev)) {
 746                 /* Release reference from device_initialize(). */
 747                 put_device(&cdev->dev);
 748                 return -ENODEV;
 749         }
 750         return 0;
 751 }
 752
 753 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 754 {
 755         struct ccw_device *cdev;
 756         int ret;
 757
 758         cdev = io_subchannel_allocate_dev(sch);
 759         if (!IS_ERR(cdev)) {
 760                 ret = io_subchannel_initialize_dev(sch, cdev);
 761                 if (ret) {
 762                         kfree(cdev);
 763                         cdev = ERR_PTR(ret);
 764                 }
 765         }
 766         return cdev;
 767 }
 768
 769 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 770
 771 static void sch_attach_device(struct subchannel *sch,
 772                               struct ccw_device *cdev)
 773 {
 774         css_update_ssd_info(sch);
 775         spin_lock_irq(sch->lock);
 776         sch_set_cdev(sch, cdev);
 777         cdev->private->schid = sch->schid;
 778         cdev->ccwlock = sch->lock;
 779         ccw_device_trigger_reprobe(cdev);
 780         spin_unlock_irq(sch->lock);
 781 }
 782
 783 static void sch_attach_disconnected_device(struct subchannel *sch,
 784                                            struct ccw_device *cdev)
 785 {
 786         struct subchannel *other_sch;
 787         int ret;
 788
 789         /* Get reference for new parent. */
 790         if (!get_device(&sch->dev))
 791                 return;
 792         other_sch = to_subchannel(cdev->dev.parent);
 793         /* Note: device_move() changes cdev->dev.parent */
 794         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 795         if (ret) {
 796                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 797                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 798                               cdev->private->dev_id.devno, ret);
 799                 /* Put reference for new parent. */
 800                 put_device(&sch->dev);
 801                 return;
 802         }
 803         sch_set_cdev(other_sch, NULL);
 804         /* No need to keep a subchannel without ccw device around. */
 805         css_sch_device_unregister(other_sch);
 806         sch_attach_device(sch, cdev);
 807         /* Put reference for old parent. */
 808         put_device(&other_sch->dev);
 809 }
 810
 811 static void sch_attach_orphaned_device(struct subchannel *sch,
 812                                        struct ccw_device *cdev)
 813 {
 814         int ret;
 815         struct subchannel *pseudo_sch;
 816
 817         /* Get reference for new parent. */
 818         if (!get_device(&sch->dev))
 819                 return;
 820         pseudo_sch = to_subchannel(cdev->dev.parent);
 821         /*
 822          * Try to move the ccw device to its new subchannel.
 823          * Note: device_move() changes cdev->dev.parent
 824          */
 825         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 826         if (ret) {
 827                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 828                               "failed (ret=%d)!\n",
 829                               cdev->private->dev_id.ssid,
 830                               cdev->private->dev_id.devno, ret);
 831                 /* Put reference for new parent. */
 832                 put_device(&sch->dev);
 833                 return;
 834         }
 835         sch_attach_device(sch, cdev);
 836         /* Put reference on pseudo subchannel. */
 837         put_device(&pseudo_sch->dev);
 838 }
 839
 840 static void sch_create_and_recog_new_device(struct subchannel *sch)
 841 {
 842         struct ccw_device *cdev;
 843
 844         /* Need to allocate a new ccw device. */
 845         cdev = io_subchannel_create_ccwdev(sch);
 846         if (IS_ERR(cdev)) {
 847                 /* OK, we did everything we could... */
 848                 css_sch_device_unregister(sch);
 849                 return;
 850         }
 851         spin_lock_irq(sch->lock);
 852         sch_set_cdev(sch, cdev);
 853         spin_unlock_irq(sch->lock);
 854         /* Start recognition for the new ccw device. */
 855         if (io_subchannel_recog(cdev, sch)) {
 856                 spin_lock_irq(sch->lock);
 857                 sch_set_cdev(sch, NULL);
 858                 spin_unlock_irq(sch->lock);
 859                 css_sch_device_unregister(sch);
 860                 /* Put reference from io_subchannel_create_ccwdev(). */
 861                 put_device(&sch->dev);
 862                 /* Give up initial reference. */
 863                 put_device(&cdev->dev);
 864         }
 865 }
 866
 867
 868 void ccw_device_move_to_orphanage(struct work_struct *work)
 869 {
 870         struct ccw_device_private *priv;
 871         struct ccw_device *cdev;
 872         struct ccw_device *replacing_cdev;
 873         struct subchannel *sch;
 874         int ret;
 875         struct channel_subsystem *css;
 876         struct ccw_dev_id dev_id;
 877
 878         priv = container_of(work, struct ccw_device_private, kick_work);
 879         cdev = priv->cdev;
 880         sch = to_subchannel(cdev->dev.parent);
 881         css = to_css(sch->dev.parent);
 882         dev_id.devno = sch->schib.pmcw.dev;
 883         dev_id.ssid = sch->schid.ssid;
 884
 885         /* Increase refcount for pseudo subchannel. */
 886         get_device(&css->pseudo_subchannel->dev);
 887         /*
 888          * Move the orphaned ccw device to the orphanage so the replacing
 889          * ccw device can take its place on the subchannel.
 890          * Note: device_move() changes cdev->dev.parent
 891          */
 892         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev,
 893                 DPM_ORDER_NONE);
 894         if (ret) {
 895                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 896                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 897                               cdev->private->dev_id.devno, ret);
 898                 /* Decrease refcount for pseudo subchannel again. */
 899                 put_device(&css->pseudo_subchannel->dev);
 900                 return;
 901         }
 902         cdev->ccwlock = css->pseudo_subchannel->lock;
 903         /*
 904          * Search for the replacing ccw device
 905          * - among the disconnected devices
 906          * - in the orphanage
 907          */
 908         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 909         if (replacing_cdev) {
 910                 sch_attach_disconnected_device(sch, replacing_cdev);
 911                 /* Release reference from get_disc_ccwdev_by_dev_id() */
 912                 put_device(&replacing_cdev->dev);
 913                 /* Release reference of subchannel from old cdev. */
 914                 put_device(&sch->dev);
 915                 return;
 916         }
 917         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 918         if (replacing_cdev) {
 919                 sch_attach_orphaned_device(sch, replacing_cdev);
 920                 /* Release reference from get_orphaned_ccwdev_by_dev_id() */
 921                 put_device(&replacing_cdev->dev);
 922                 /* Release reference of subchannel from old cdev. */
 923                 put_device(&sch->dev);
 924                 return;
 925         }
 926         sch_create_and_recog_new_device(sch);
 927         /* Release reference of subchannel from old cdev. */
 928         put_device(&sch->dev);
 929 }
 930
 931 /*
 932  * Register recognized device.
 933  */
 934 static void
 935 io_subchannel_register(struct work_struct *work)
 936 {
 937         struct ccw_device_private *priv;
 938         struct ccw_device *cdev;
 939         struct subchannel *sch;
 940         int ret;
 941         unsigned long flags;
 942
 943         priv = container_of(work, struct ccw_device_private, kick_work);
 944         cdev = priv->cdev;
 945         sch = to_subchannel(cdev->dev.parent);
 946         /*
 947          * Check if subchannel is still registered. It may have become
 948          * unregistered if a machine check hit us after finishing
 949          * device recognition but before the register work could be
 950          * queued.
 951          */
 952         if (!device_is_registered(&sch->dev))
 953                 goto out_err;
 954         css_update_ssd_info(sch);
 955         /*
 956          * io_subchannel_register() will also be called after device
 957          * recognition has been done for a boxed device (which will already
 958          * be registered). We need to reprobe since we may now have sense id
 959          * information.
 960          */
 961         if (device_is_registered(&cdev->dev)) {
 962                 if (!cdev->drv) {
 963                         ret = device_reprobe(&cdev->dev);
 964                         if (ret)
 965                                 /* We can't do much here. */
 966                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 967                                               " %d for 0.%x.%04x\n", ret,
 968                                               cdev->private->dev_id.ssid,
 969                                               cdev->private->dev_id.devno);
 970                 }
 971                 goto out;
 972         }
 973         /*
 974          * Now we know this subchannel will stay, we can throw
 975          * our delayed uevent.
 976          */
 977         dev_set_uevent_suppress(&sch->dev, 0);
 978         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 979         /* make it known to the system */
 980         ret = ccw_device_register(cdev);
 981         if (ret) {
 982                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 983                               cdev->private->dev_id.ssid,
 984                               cdev->private->dev_id.devno, ret);
 985                 spin_lock_irqsave(sch->lock, flags);
 986                 sch_set_cdev(sch, NULL);
 987                 spin_unlock_irqrestore(sch->lock, flags);
 988                 /* Release initial device reference. */
 989                 put_device(&cdev->dev);
 990                 goto out_err;
 991         }
 992 out:
 993         cdev->private->flags.recog_done = 1;
 994         wake_up(&cdev->private->wait_q);
 995 out_err:
 996         /* Release reference for workqueue processing. */
 997         put_device(&cdev->dev);
 998         if (atomic_dec_and_test(&ccw_device_init_count))
 999                 wake_up(&ccw_device_init_wq);
1000 }
1001
1002 static void ccw_device_call_sch_unregister(struct work_struct *work)
1003 {
1004         struct ccw_device_private *priv;
1005         struct ccw_device *cdev;
1006         struct subchannel *sch;
1007
1008         priv = container_of(work, struct ccw_device_private, kick_work);
1009         cdev = priv->cdev;
1010         /* Get subchannel reference for local processing. */
1011         if (!get_device(cdev->dev.parent))
1012                 return;
1013         sch = to_subchannel(cdev->dev.parent);
1014         css_sch_device_unregister(sch);
1015         /* Reset intparm to zeroes. */
1016         sch->config.intparm = 0;
1017         cio_commit_config(sch);
1018         /* Release cdev reference for workqueue processing.*/
1019         put_device(&cdev->dev);
1020         /* Release subchannel reference for local processing. */
1021         put_device(&sch->dev);
1022 }
1023
1024 void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
1025 {
1026         PREPARE_WORK(&cdev->private->kick_work,
1027                      ccw_device_call_sch_unregister);
1028         queue_work(slow_path_wq, &cdev->private->kick_work);
1029 }
1030
1031 /*
1032  * subchannel recognition done. Called from the state machine.
1033  */
1034 void
1035 io_subchannel_recog_done(struct ccw_device *cdev)
1036 {
1037         if (css_init_done == 0) {
1038                 cdev->private->flags.recog_done = 1;
1039                 return;
1040         }
1041         switch (cdev->private->state) {
1042         case DEV_STATE_BOXED:
1043                 /* Device did not respond in time. */
1044         case DEV_STATE_NOT_OPER:
1045                 cdev->private->flags.recog_done = 1;
1046                 /* Remove device found not operational. */
1047                 if (!get_device(&cdev->dev))
1048                         break;
1049                 ccw_device_schedule_sch_unregister(cdev);
1050                 if (atomic_dec_and_test(&ccw_device_init_count))
1051                         wake_up(&ccw_device_init_wq);
1052                 break;
1053         case DEV_STATE_OFFLINE:
1054                 /*
1055                  * We can't register the device in interrupt context so
1056                  * we schedule a work item.
1057                  */
1058                 if (!get_device(&cdev->dev))
1059                         break;
1060                 PREPARE_WORK(&cdev->private->kick_work,
1061                              io_subchannel_register);
1062                 queue_work(slow_path_wq, &cdev->private->kick_work);
1063                 break;
1064         }
1065 }
1066
1067 static int
1068 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1069 {
1070         int rc;
1071         struct ccw_device_private *priv;
1072
1073         sch_set_cdev(sch, cdev);
1074         cdev->ccwlock = sch->lock;
1075
1076         /* Init private data. */
1077         priv = cdev->private;
1078         priv->dev_id.devno = sch->schib.pmcw.dev;
1079         priv->dev_id.ssid = sch->schid.ssid;
1080         priv->schid = sch->schid;
1081         priv->state = DEV_STATE_NOT_OPER;
1082         INIT_LIST_HEAD(&priv->cmb_list);
1083         init_waitqueue_head(&priv->wait_q);
1084         init_timer(&priv->timer);
1085
1086         /* Set an initial name for the device. */
1087         if (cio_is_console(sch->schid))
1088                 cdev->dev.init_name = cio_get_console_cdev_name(sch);
1089         else
1090                 dev_set_name(&cdev->dev, "0.%x.%04x",
1091                              sch->schid.ssid, sch->schib.pmcw.dev);
1092
1093         /* Increase counter of devices currently in recognition. */
1094         atomic_inc(&ccw_device_init_count);
1095
1096         /* Start async. device sensing. */
1097         spin_lock_irq(sch->lock);
1098         rc = ccw_device_recognition(cdev);
1099         spin_unlock_irq(sch->lock);
1100         if (rc) {
1101                 if (atomic_dec_and_test(&ccw_device_init_count))
1102                         wake_up(&ccw_device_init_wq);
1103         }
1104         return rc;
1105 }
1106
1107 static void ccw_device_move_to_sch(struct work_struct *work)
1108 {
1109         struct ccw_device_private *priv;
1110         int rc;
1111         struct subchannel *sch;
1112         struct ccw_device *cdev;
1113         struct subchannel *former_parent;
1114
1115         priv = container_of(work, struct ccw_device_private, kick_work);
1116         sch = priv->sch;
1117         cdev = priv->cdev;
1118         former_parent = to_subchannel(cdev->dev.parent);
1119         /* Get reference for new parent. */
1120         if (!get_device(&sch->dev))
1121                 return;
1122         mutex_lock(&sch->reg_mutex);
1123         /*
1124          * Try to move the ccw device to its new subchannel.
1125          * Note: device_move() changes cdev->dev.parent
1126          */
1127         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
1128         mutex_unlock(&sch->reg_mutex);
1129         if (rc) {
1130                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1131                               "0.%x.%04x failed (ret=%d)!\n",
1132                               cdev->private->dev_id.ssid,
1133                               cdev->private->dev_id.devno, sch->schid.ssid,
1134                               sch->schid.sch_no, rc);
1135                 css_sch_device_unregister(sch);
1136                 /* Put reference for new parent again. */
1137                 put_device(&sch->dev);
1138                 goto out;
1139         }
1140         if (!sch_is_pseudo_sch(former_parent)) {
1141                 spin_lock_irq(former_parent->lock);
1142                 sch_set_cdev(former_parent, NULL);
1143                 spin_unlock_irq(former_parent->lock);
1144                 css_sch_device_unregister(former_parent);
1145                 /* Reset intparm to zeroes. */
1146                 former_parent->config.intparm = 0;
1147                 cio_commit_config(former_parent);
1148         }
1149         sch_attach_device(sch, cdev);
1150 out:
1151         /* Put reference for old parent. */
1152         put_device(&former_parent->dev);
1153         put_device(&cdev->dev);
1154 }
1155
1156 static void io_subchannel_irq(struct subchannel *sch)
1157 {
1158         struct ccw_device *cdev;
1159
1160         cdev = sch_get_cdev(sch);
1161
1162         CIO_TRACE_EVENT(3, "IRQ");
1163         CIO_TRACE_EVENT(3, dev_name(&sch->dev));
1164         if (cdev)
1165                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1166 }
1167
1168 void io_subchannel_init_config(struct subchannel *sch)
1169 {
1170         memset(&sch->config, 0, sizeof(sch->config));
1171         sch->config.csense = 1;
1172         /* Use subchannel mp mode when there is more than 1 installed CHPID. */
1173         if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
1174                 sch->config.mp = 1;
1175 }
1176
1177 static void io_subchannel_init_fields(struct subchannel *sch)
1178 {
1179         if (cio_is_console(sch->schid))
1180                 sch->opm = 0xff;
1181         else
1182                 sch->opm = chp_get_sch_opm(sch);
1183         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1184         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1185
1186         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1187                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1188                       sch->schib.pmcw.dev, sch->schid.ssid,
1189                       sch->schid.sch_no, sch->schib.pmcw.pim,
1190                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1191
1192         io_subchannel_init_config(sch);
1193 }
1194
1195 static void io_subchannel_do_unreg(struct work_struct *work)
1196 {
1197         struct subchannel *sch;
1198
1199         sch = container_of(work, struct subchannel, work);
1200         css_sch_device_unregister(sch);
1201         /* Reset intparm to zeroes. */
1202         sch->config.intparm = 0;
1203         cio_commit_config(sch);
1204         put_device(&sch->dev);
1205 }
1206
1207 /* Schedule unregister if we have no cdev. */
1208 static void io_subchannel_schedule_removal(struct subchannel *sch)
1209 {
1210         get_device(&sch->dev);
1211         INIT_WORK(&sch->work, io_subchannel_do_unreg);
1212         queue_work(slow_path_wq, &sch->work);
1213 }
1214
1215 /*
1216  * Note: We always return 0 so that we bind to the device even on error.
1217  * This is needed so that our remove function is called on unregister.
1218  */
1219 static int io_subchannel_probe(struct subchannel *sch)
1220 {
1221         struct ccw_device *cdev;
1222         int rc;
1223         unsigned long flags;
1224         struct ccw_dev_id dev_id;
1225
1226         cdev = sch_get_cdev(sch);
1227         if (cdev) {
1228                 rc = sysfs_create_group(&sch->dev.kobj,
1229                                         &io_subchannel_attr_group);
1230                 if (rc)
1231                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1232                                       "attributes for subchannel "
1233                                       "0.%x.%04x (rc=%d)\n",
1234                                       sch->schid.ssid, sch->schid.sch_no, rc);
1235                 /*
1236                  * This subchannel already has an associated ccw_device.
1237                  * Throw the delayed uevent for the subchannel, register
1238                  * the ccw_device and exit. This happens for all early
1239                  * devices, e.g. the console.
1240                  */
1241                 dev_set_uevent_suppress(&sch->dev, 0);
1242                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1243                 cdev->dev.groups = ccwdev_attr_groups;
1244                 device_initialize(&cdev->dev);
1245                 ccw_device_register(cdev);
1246                 /*
1247                  * Check if the device is already online. If it is
1248                  * the reference count needs to be corrected since we
1249                  * didn't obtain a reference in ccw_device_set_online.
1250                  */
1251                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1252                     cdev->private->state != DEV_STATE_OFFLINE &&
1253                     cdev->private->state != DEV_STATE_BOXED)
1254                         get_device(&cdev->dev);
1255                 return 0;
1256         }
1257         io_subchannel_init_fields(sch);
1258         rc = cio_commit_config(sch);
1259         if (rc)
1260                 goto out_schedule;
1261         rc = sysfs_create_group(&sch->dev.kobj,
1262                                 &io_subchannel_attr_group);
1263         if (rc)
1264                 goto out_schedule;
1265         /* Allocate I/O subchannel private data. */
1266         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1267                                GFP_KERNEL | GFP_DMA);
1268         if (!sch->private)
1269                 goto out_err;
1270         /*
1271          * First check if a fitting device may be found amongst the
1272          * disconnected devices or in the orphanage.
1273          */
1274         dev_id.devno = sch->schib.pmcw.dev;
1275         dev_id.ssid = sch->schid.ssid;
1276         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1277         if (!cdev)
1278                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1279                                                      &dev_id);
1280         if (cdev) {
1281                 /*
1282                  * Schedule moving the device until when we have a registered
1283                  * subchannel to move to and succeed the probe. We can
1284                  * unregister later again, when the probe is through.
1285                  */
1286                 cdev->private->sch = sch;
1287                 PREPARE_WORK(&cdev->private->kick_work,
1288                              ccw_device_move_to_sch);
1289                 queue_work(slow_path_wq, &cdev->private->kick_work);
1290                 return 0;
1291         }
1292         cdev = io_subchannel_create_ccwdev(sch);
1293         if (IS_ERR(cdev))
1294                 goto out_err;
1295         rc = io_subchannel_recog(cdev, sch);
1296         if (rc) {
1297                 spin_lock_irqsave(sch->lock, flags);
1298                 io_subchannel_recog_done(cdev);
1299                 spin_unlock_irqrestore(sch->lock, flags);
1300         }
1301         return 0;
1302 out_err:
1303         kfree(sch->private);
1304         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1305 out_schedule:
1306         io_subchannel_schedule_removal(sch);
1307         return 0;
1308 }
1309
1310 static int
1311 io_subchannel_remove (struct subchannel *sch)
1312 {
1313         struct ccw_device *cdev;
1314         unsigned long flags;
1315
1316         cdev = sch_get_cdev(sch);
1317         if (!cdev)
1318                 return 0;
1319         /* Set ccw device to not operational and drop reference. */
1320         spin_lock_irqsave(cdev->ccwlock, flags);
1321         sch_set_cdev(sch, NULL);
1322         cdev->private->state = DEV_STATE_NOT_OPER;
1323         spin_unlock_irqrestore(cdev->ccwlock, flags);
1324         ccw_device_unregister(cdev);
1325         put_device(&cdev->dev);
1326         kfree(sch->private);
1327         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1328         return 0;
1329 }
1330
1331 static int io_subchannel_notify(struct subchannel *sch, int event)
1332 {
1333         struct ccw_device *cdev;
1334
1335         cdev = sch_get_cdev(sch);
1336         if (!cdev)
1337                 return 0;
1338         return ccw_device_notify(cdev, event);
1339 }
1340
1341 static void io_subchannel_verify(struct subchannel *sch)
1342 {
1343         struct ccw_device *cdev;
1344
1345         cdev = sch_get_cdev(sch);
1346         if (cdev)
1347                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1348 }
1349
1350 static int check_for_io_on_path(struct subchannel *sch, int mask)
1351 {
1352         if (cio_update_schib(sch))
1353                 return 0;
1354         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1355                 return 1;
1356         return 0;
1357 }
1358
1359 static void terminate_internal_io(struct subchannel *sch,
1360                                   struct ccw_device *cdev)
1361 {
1362         if (cio_clear(sch)) {
1363                 /* Recheck device in case clear failed. */
1364                 sch->lpm = 0;
1365                 if (cdev->online)
1366                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1367                 else
1368                         css_schedule_eval(sch->schid);
1369                 return;
1370         }
1371         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1372         /* Request retry of internal operation. */
1373         cdev->private->flags.intretry = 1;
1374         /* Call handler. */
1375         if (cdev->handler)
1376                 cdev->handler(cdev, cdev->private->intparm,
1377                               ERR_PTR(-EIO));
1378 }
1379
1380 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1381 {
1382         struct ccw_device *cdev;
1383
1384         cdev = sch_get_cdev(sch);
1385         if (!cdev)
1386                 return;
1387         if (check_for_io_on_path(sch, mask)) {
1388                 if (cdev->private->state == DEV_STATE_ONLINE)
1389                         ccw_device_kill_io(cdev);
1390                 else {
1391                         terminate_internal_io(sch, cdev);
1392                         /* Re-start path verification. */
1393                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1394                 }
1395         } else
1396                 /* trigger path verification. */
1397                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1398
1399 }
1400
1401 static int io_subchannel_chp_event(struct subchannel *sch,
1402                                    struct chp_link *link, int event)
1403 {
1404         int mask;
1405
1406         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1407         if (!mask)
1408                 return 0;
1409         switch (event) {
1410         case CHP_VARY_OFF:
1411                 sch->opm &= ~mask;
1412                 sch->lpm &= ~mask;
1413                 io_subchannel_terminate_path(sch, mask);
1414                 break;
1415         case CHP_VARY_ON:
1416                 sch->opm |= mask;
1417                 sch->lpm |= mask;
1418                 io_subchannel_verify(sch);
1419                 break;
1420         case CHP_OFFLINE:
1421                 if (cio_update_schib(sch))
1422                         return -ENODEV;
1423                 io_subchannel_terminate_path(sch, mask);
1424                 break;
1425         case CHP_ONLINE:
1426                 if (cio_update_schib(sch))
1427                         return -ENODEV;
1428                 sch->lpm |= mask & sch->opm;
1429                 io_subchannel_verify(sch);
1430                 break;
1431         }
1432         return 0;
1433 }
1434
1435 static void
1436 io_subchannel_shutdown(struct subchannel *sch)
1437 {
1438         struct ccw_device *cdev;
1439         int ret;
1440
1441         cdev = sch_get_cdev(sch);
1442
1443         if (cio_is_console(sch->schid))
1444                 return;
1445         if (!sch->schib.pmcw.ena)
1446                 /* Nothing to do. */
1447                 return;
1448         ret = cio_disable_subchannel(sch);
1449         if (ret != -EBUSY)
1450                 /* Subchannel is disabled, we're done. */
1451                 return;
1452         cdev->private->state = DEV_STATE_QUIESCE;
1453         if (cdev->handler)
1454                 cdev->handler(cdev, cdev->private->intparm,
1455                               ERR_PTR(-EIO));
1456         ret = ccw_device_cancel_halt_clear(cdev);
1457         if (ret == -EBUSY) {
1458                 ccw_device_set_timeout(cdev, HZ/10);
1459                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1460         }
1461         cio_disable_subchannel(sch);
1462 }
1463
1464 static int io_subchannel_get_status(struct subchannel *sch)
1465 {
1466         struct schib schib;
1467
1468         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1469                 return CIO_GONE;
1470         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1471                 return CIO_REVALIDATE;
1472         if (!sch->lpm)
1473                 return CIO_NO_PATH;
1474         return CIO_OPER;
1475 }
1476
1477 static int device_is_disconnected(struct ccw_device *cdev)
1478 {
1479         if (!cdev)
1480                 return 0;
1481         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1482                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1483 }
1484
1485 static int recovery_check(struct device *dev, void *data)
1486 {
1487         struct ccw_device *cdev = to_ccwdev(dev);
1488         int *redo = data;
1489
1490         spin_lock_irq(cdev->ccwlock);
1491         switch (cdev->private->state) {
1492         case DEV_STATE_DISCONNECTED:
1493                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1494                               cdev->private->dev_id.ssid,
1495                               cdev->private->dev_id.devno);
1496                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1497                 *redo = 1;
1498                 break;
1499         case DEV_STATE_DISCONNECTED_SENSE_ID:
1500                 *redo = 1;
1501                 break;
1502         }
1503         spin_unlock_irq(cdev->ccwlock);
1504
1505         return 0;
1506 }
1507
1508 static void recovery_work_func(struct work_struct *unused)
1509 {
1510         int redo = 0;
1511
1512         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1513         if (redo) {
1514                 spin_lock_irq(&recovery_lock);
1515                 if (!timer_pending(&recovery_timer)) {
1516                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1517                                 recovery_phase++;
1518                         mod_timer(&recovery_timer, jiffies +
1519                                   recovery_delay[recovery_phase] * HZ);
1520                 }
1521                 spin_unlock_irq(&recovery_lock);
1522         } else
1523                 CIO_MSG_EVENT(4, "recovery: end\n");
1524 }
1525
1526 static DECLARE_WORK(recovery_work, recovery_work_func);
1527
1528 static void recovery_func(unsigned long data)
1529 {
1530         /*
1531          * We can't do our recovery in softirq context and it's not
1532          * performance critical, so we schedule it.
1533          */
1534         schedule_work(&recovery_work);
1535 }
1536
1537 static void ccw_device_schedule_recovery(void)
1538 {
1539         unsigned long flags;
1540
1541         CIO_MSG_EVENT(4, "recovery: schedule\n");
1542         spin_lock_irqsave(&recovery_lock, flags);
1543         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1544                 recovery_phase = 0;
1545                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1546         }
1547         spin_unlock_irqrestore(&recovery_lock, flags);
1548 }
1549
1550 static int purge_fn(struct device *dev, void *data)
1551 {
1552         struct ccw_device *cdev = to_ccwdev(dev);
1553         struct ccw_device_private *priv = cdev->private;
1554         int unreg;
1555
1556         spin_lock_irq(cdev->ccwlock);
1557         unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1558                 (priv->state == DEV_STATE_OFFLINE);
1559         spin_unlock_irq(cdev->ccwlock);
1560         if (!unreg)
1561                 goto out;
1562         if (!get_device(&cdev->dev))
1563                 goto out;
1564         CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1565                       priv->dev_id.devno);
1566         ccw_device_schedule_sch_unregister(cdev);
1567
1568 out:
1569         /* Abort loop in case of pending signal. */
1570         if (signal_pending(current))
1571                 return -EINTR;
1572
1573         return 0;
1574 }
1575
1576 /**
1577  * ccw_purge_blacklisted - purge unused, blacklisted devices
1578  *
1579  * Unregister all ccw devices that are offline and on the blacklist.
1580  */
1581 int ccw_purge_blacklisted(void)
1582 {
1583         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1584         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1585         return 0;
1586 }
1587
1588 static void device_set_disconnected(struct ccw_device *cdev)
1589 {
1590         if (!cdev)
1591                 return;
1592         ccw_device_set_timeout(cdev, 0);
1593         cdev->private->flags.fake_irb = 0;
1594         cdev->private->state = DEV_STATE_DISCONNECTED;
1595         if (cdev->online)
1596                 ccw_device_schedule_recovery();
1597 }
1598
1599 void ccw_device_set_notoper(struct ccw_device *cdev)
1600 {
1601         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1602
1603         CIO_TRACE_EVENT(2, "notoper");
1604         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1605         ccw_device_set_timeout(cdev, 0);
1606         cio_disable_subchannel(sch);
1607         cdev->private->state = DEV_STATE_NOT_OPER;
1608 }
1609
1610 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1611 {
1612         int event, ret, disc;
1613         unsigned long flags;
1614         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1615         struct ccw_device *cdev;
1616
1617         spin_lock_irqsave(sch->lock, flags);
1618         cdev = sch_get_cdev(sch);
1619         disc = device_is_disconnected(cdev);
1620         if (disc && slow) {
1621                 /* Disconnected devices are evaluated directly only.*/
1622                 spin_unlock_irqrestore(sch->lock, flags);
1623                 return 0;
1624         }
1625         /* No interrupt after machine check - kill pending timers. */
1626         if (cdev)
1627                 ccw_device_set_timeout(cdev, 0);
1628         if (!disc && !slow) {
1629                 /* Non-disconnected devices are evaluated on the slow path. */
1630                 spin_unlock_irqrestore(sch->lock, flags);
1631                 return -EAGAIN;
1632         }
1633         event = io_subchannel_get_status(sch);
1634         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1635                       sch->schid.ssid, sch->schid.sch_no, event,
1636                       disc ? "disconnected" : "normal",
1637                       slow ? "slow" : "fast");
1638         /* Analyze subchannel status. */
1639         action = NONE;
1640         switch (event) {
1641         case CIO_NO_PATH:
1642                 if (disc) {
1643                         /* Check if paths have become available. */
1644                         action = REPROBE;
1645                         break;
1646                 }
1647                 /* fall through */
1648         case CIO_GONE:
1649                 /* Ask driver what to do with device. */
1650                 if (io_subchannel_notify(sch, event))
1651                         action = DISC;
1652                 else
1653                         action = UNREGISTER;
1654                 break;
1655         case CIO_REVALIDATE:
1656                 /* Device will be removed, so no notify necessary. */
1657                 if (disc)
1658                         /* Reprobe because immediate unregister might block. */
1659                         action = REPROBE;
1660                 else
1661                         action = UNREGISTER_PROBE;
1662                 break;
1663         case CIO_OPER:
1664                 if (disc)
1665                         /* Get device operational again. */
1666                         action = REPROBE;
1667                 break;
1668         }
1669         /* Perform action. */
1670         ret = 0;
1671         switch (action) {
1672         case UNREGISTER:
1673         case UNREGISTER_PROBE:
1674                 ccw_device_set_notoper(cdev);
1675                 /* Unregister device (will use subchannel lock). */
1676                 spin_unlock_irqrestore(sch->lock, flags);
1677                 css_sch_device_unregister(sch);
1678                 spin_lock_irqsave(sch->lock, flags);
1679
1680                 /* Reset intparm to zeroes. */
1681                 sch->config.intparm = 0;
1682                 cio_commit_config(sch);
1683                 break;
1684         case REPROBE:
1685                 ccw_device_trigger_reprobe(cdev);
1686                 break;
1687         case DISC:
1688                 device_set_disconnected(cdev);
1689                 break;
1690         default:
1691                 break;
1692         }
1693         spin_unlock_irqrestore(sch->lock, flags);
1694         /* Probe if necessary. */
1695         if (action == UNREGISTER_PROBE)
1696                 ret = css_probe_device(sch->schid);
1697
1698         return ret;
1699 }
1700
1701 #ifdef CONFIG_CCW_CONSOLE
1702 static struct ccw_device console_cdev;
1703 static char console_cdev_name[10] = "0.x.xxxx";
1704 static struct ccw_device_private console_private;
1705 static int console_cdev_in_use;
1706
1707 static DEFINE_SPINLOCK(ccw_console_lock);
1708
1709 spinlock_t * cio_get_console_lock(void)
1710 {
1711         return &ccw_console_lock;
1712 }
1713
1714 static int ccw_device_console_enable(struct ccw_device *cdev,
1715                                      struct subchannel *sch)
1716 {
1717         int rc;
1718
1719         /* Attach subchannel private data. */
1720         sch->private = cio_get_console_priv();
1721         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1722         io_subchannel_init_fields(sch);
1723         rc = cio_commit_config(sch);
1724         if (rc)
1725                 return rc;
1726         sch->driver = &io_subchannel_driver;
1727         /* Initialize the ccw_device structure. */
1728         cdev->dev.parent= &sch->dev;
1729         rc = io_subchannel_recog(cdev, sch);
1730         if (rc)
1731                 return rc;
1732
1733         /* Now wait for the async. recognition to come to an end. */
1734         spin_lock_irq(cdev->ccwlock);
1735         while (!dev_fsm_final_state(cdev))
1736                 wait_cons_dev();
1737         rc = -EIO;
1738         if (cdev->private->state != DEV_STATE_OFFLINE)
1739                 goto out_unlock;
1740         ccw_device_online(cdev);
1741         while (!dev_fsm_final_state(cdev))
1742                 wait_cons_dev();
1743         if (cdev->private->state != DEV_STATE_ONLINE)
1744                 goto out_unlock;
1745         rc = 0;
1746 out_unlock:
1747         spin_unlock_irq(cdev->ccwlock);
1748         return 0;
1749 }
1750
1751 struct ccw_device *
1752 ccw_device_probe_console(void)
1753 {
1754         struct subchannel *sch;
1755         int ret;
1756
1757         if (xchg(&console_cdev_in_use, 1) != 0)
1758                 return ERR_PTR(-EBUSY);
1759         sch = cio_probe_console();
1760         if (IS_ERR(sch)) {
1761                 console_cdev_in_use = 0;
1762                 return (void *) sch;
1763         }
1764         memset(&console_cdev, 0, sizeof(struct ccw_device));
1765         memset(&console_private, 0, sizeof(struct ccw_device_private));
1766         console_cdev.private = &console_private;
1767         console_private.cdev = &console_cdev;
1768         ret = ccw_device_console_enable(&console_cdev, sch);
1769         if (ret) {
1770                 cio_release_console();
1771                 console_cdev_in_use = 0;
1772                 return ERR_PTR(ret);
1773         }
1774         console_cdev.online = 1;
1775         return &console_cdev;
1776 }
1777
1778
1779 const char *cio_get_console_cdev_name(struct subchannel *sch)
1780 {
1781         snprintf(console_cdev_name, 10, "0.%x.%04x",
1782                  sch->schid.ssid, sch->schib.pmcw.dev);
1783         return (const char *)console_cdev_name;
1784 }
1785 #endif
1786
1787 /*
1788  * get ccw_device matching the busid, but only if owned by cdrv
1789  */
1790 static int
1791 __ccwdev_check_busid(struct device *dev, void *id)
1792 {
1793         char *bus_id;
1794
1795         bus_id = id;
1796
1797         return (strcmp(bus_id, dev_name(dev)) == 0);
1798 }
1799
1800
1801 /**
1802  * get_ccwdev_by_busid() - obtain device from a bus id
1803  * @cdrv: driver the device is owned by
1804  * @bus_id: bus id of the device to be searched
1805  *
1806  * This function searches all devices owned by @cdrv for a device with a bus
1807  * id matching @bus_id.
1808  * Returns:
1809  *  If a match is found, its reference count of the found device is increased
1810  *  and it is returned; else %NULL is returned.
1811  */
1812 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1813                                        const char *bus_id)
1814 {
1815         struct device *dev;
1816         struct device_driver *drv;
1817
1818         drv = get_driver(&cdrv->driver);
1819         if (!drv)
1820                 return NULL;
1821
1822         dev = driver_find_device(drv, NULL, (void *)bus_id,
1823                                  __ccwdev_check_busid);
1824         put_driver(drv);
1825
1826         return dev ? to_ccwdev(dev) : NULL;
1827 }
1828
1829 /************************** device driver handling ************************/
1830
1831 /* This is the implementation of the ccw_driver class. The probe, remove
1832  * and release methods are initially very similar to the device_driver
1833  * implementations, with the difference that they have ccw_device
1834  * arguments.
1835  *
1836  * A ccw driver also contains the information that is needed for
1837  * device matching.
1838  */
1839 static int
1840 ccw_device_probe (struct device *dev)
1841 {
1842         struct ccw_device *cdev = to_ccwdev(dev);
1843         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1844         int ret;
1845
1846         cdev->drv = cdrv; /* to let the driver call _set_online */
1847
1848         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1849
1850         if (ret) {
1851                 cdev->drv = NULL;
1852                 return ret;
1853         }
1854
1855         return 0;
1856 }
1857
1858 static int
1859 ccw_device_remove (struct device *dev)
1860 {
1861         struct ccw_device *cdev = to_ccwdev(dev);
1862         struct ccw_driver *cdrv = cdev->drv;
1863         int ret;
1864
1865         if (cdrv->remove)
1866                 cdrv->remove(cdev);
1867         if (cdev->online) {
1868                 cdev->online = 0;
1869                 spin_lock_irq(cdev->ccwlock);
1870                 ret = ccw_device_offline(cdev);
1871                 spin_unlock_irq(cdev->ccwlock);
1872                 if (ret == 0)
1873                         wait_event(cdev->private->wait_q,
1874                                    dev_fsm_final_state(cdev));
1875                 else
1876                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1877                                       "device 0.%x.%04x\n",
1878                                       ret, cdev->private->dev_id.ssid,
1879                                       cdev->private->dev_id.devno);
1880                 /* Give up reference obtained in ccw_device_set_online(). */
1881                 put_device(&cdev->dev);
1882         }
1883         ccw_device_set_timeout(cdev, 0);
1884         cdev->drv = NULL;
1885         return 0;
1886 }
1887
1888 static void ccw_device_shutdown(struct device *dev)
1889 {
1890         struct ccw_device *cdev;
1891
1892         cdev = to_ccwdev(dev);
1893         if (cdev->drv && cdev->drv->shutdown)
1894                 cdev->drv->shutdown(cdev);
1895         disable_cmf(cdev);
1896 }
1897
1898 struct bus_type ccw_bus_type = {
1899         .name   = "ccw",
1900         .match  = ccw_bus_match,
1901         .uevent = ccw_uevent,
1902         .probe  = ccw_device_probe,
1903         .remove = ccw_device_remove,
1904         .shutdown = ccw_device_shutdown,
1905 };
1906
1907 /**
1908  * ccw_driver_register() - register a ccw driver
1909  * @cdriver: driver to be registered
1910  *
1911  * This function is mainly a wrapper around driver_register().
1912  * Returns:
1913  *   %0 on success and a negative error value on failure.
1914  */
1915 int ccw_driver_register(struct ccw_driver *cdriver)
1916 {
1917         struct device_driver *drv = &cdriver->driver;
1918
1919         drv->bus = &ccw_bus_type;
1920         drv->name = cdriver->name;
1921         drv->owner = cdriver->owner;
1922
1923         return driver_register(drv);
1924 }
1925
1926 /**
1927  * ccw_driver_unregister() - deregister a ccw driver
1928  * @cdriver: driver to be deregistered
1929  *
1930  * This function is mainly a wrapper around driver_unregister().
1931  */
1932 void ccw_driver_unregister(struct ccw_driver *cdriver)
1933 {
1934         driver_unregister(&cdriver->driver);
1935 }
1936
1937 /* Helper func for qdio. */
1938 struct subchannel_id
1939 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1940 {
1941         struct subchannel *sch;
1942
1943         sch = to_subchannel(cdev->dev.parent);
1944         return sch->schid;
1945 }
1946
1947 MODULE_LICENSE("GPL");
1948 EXPORT_SYMBOL(ccw_device_set_online);
1949 EXPORT_SYMBOL(ccw_device_set_offline);
1950 EXPORT_SYMBOL(ccw_driver_register);
1951 EXPORT_SYMBOL(ccw_driver_unregister);
1952 EXPORT_SYMBOL(get_ccwdev_by_busid);
1953 EXPORT_SYMBOL(ccw_bus_type);
1954 EXPORT_SYMBOL(ccw_device_work);
1955 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);