err.no Git - linux-2.6/blob - 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
  35 static struct timer_list recovery_timer;
  36 static DEFINE_SPINLOCK(recovery_lock);
  37 static int recovery_phase;
  38 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  39
  40 /******************* bus type handling ***********************/
  41
  42 /* The Linux driver model distinguishes between a bus type and
  43  * the bus itself. Of course we only have one channel
  44  * subsystem driver and one channel system per machine, but
  45  * we still use the abstraction. T.R. says it's a good idea. */
  46 static int
  47 ccw_bus_match (struct device * dev, struct device_driver * drv)
  48 {
  49         struct ccw_device *cdev = to_ccwdev(dev);
  50         struct ccw_driver *cdrv = to_ccwdrv(drv);
  51         const struct ccw_device_id *ids = cdrv->ids, *found;
  52
  53         if (!ids)
  54                 return 0;
  55
  56         found = ccw_device_id_match(ids, &cdev->id);
  57         if (!found)
  58                 return 0;
  59
  60         cdev->id.driver_info = found->driver_info;
  61
  62         return 1;
  63 }
  64
  65 /* Store modalias string delimited by prefix/suffix string into buffer with
  66  * specified size. Return length of resulting string (excluding trailing '\0')
  67  * even if string doesn't fit buffer (snprintf semantics). */
  68 static int snprint_alias(char *buf, size_t size,
  69                          struct ccw_device_id *id, const char *suffix)
  70 {
  71         int len;
  72
  73         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  74         if (len > size)
  75                 return len;
  76         buf += len;
  77         size -= len;
  78
  79         if (id->dev_type != 0)
  80                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  81                                 id->dev_model, suffix);
  82         else
  83                 len += snprintf(buf, size, "dtdm%s", suffix);
  84
  85         return len;
  86 }
  87
  88 /* Set up environment variables for ccw device uevent. Return 0 on success,
  89  * non-zero otherwise. */
  90 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  91 {
  92         struct ccw_device *cdev = to_ccwdev(dev);
  93         struct ccw_device_id *id = &(cdev->id);
  94         int ret;
  95         char modalias_buf[30];
  96
  97         /* CU_TYPE= */
  98         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
  99         if (ret)
 100                 return ret;
 101
 102         /* CU_MODEL= */
 103         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 104         if (ret)
 105                 return ret;
 106
 107         /* The next two can be zero, that's ok for us */
 108         /* DEV_TYPE= */
 109         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 110         if (ret)
 111                 return ret;
 112
 113         /* DEV_MODEL= */
 114         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 115         if (ret)
 116                 return ret;
 117
 118         /* MODALIAS=  */
 119         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 120         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 121         return ret;
 122 }
 123
 124 struct bus_type ccw_bus_type;
 125
 126 static void io_subchannel_irq(struct subchannel *);
 127 static int io_subchannel_probe(struct subchannel *);
 128 static int io_subchannel_remove(struct subchannel *);
 129 static void io_subchannel_shutdown(struct subchannel *);
 130 static int io_subchannel_sch_event(struct subchannel *, int);
 131 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 132                                    int);
 133
 134 static struct css_device_id io_subchannel_ids[] = {
 135         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 136         { /* end of list */ },
 137 };
 138 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 139
 140 static struct css_driver io_subchannel_driver = {
 141         .owner = THIS_MODULE,
 142         .subchannel_type = io_subchannel_ids,
 143         .name = "io_subchannel",
 144         .irq = io_subchannel_irq,
 145         .sch_event = io_subchannel_sch_event,
 146         .chp_event = io_subchannel_chp_event,
 147         .probe = io_subchannel_probe,
 148         .remove = io_subchannel_remove,
 149         .shutdown = io_subchannel_shutdown,
 150 };
 151
 152 struct workqueue_struct *ccw_device_work;
 153 struct workqueue_struct *ccw_device_notify_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         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 172         if (!ccw_device_notify_work) {
 173                 ret = -ENOMEM; /* FIXME: better errno ? */
 174                 goto out_err;
 175         }
 176         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 177         if (!slow_path_wq) {
 178                 ret = -ENOMEM; /* FIXME: better errno ? */
 179                 goto out_err;
 180         }
 181         if ((ret = bus_register (&ccw_bus_type)))
 182                 goto out_err;
 183
 184         ret = css_driver_register(&io_subchannel_driver);
 185         if (ret)
 186                 goto out_err;
 187
 188         wait_event(ccw_device_init_wq,
 189                    atomic_read(&ccw_device_init_count) == 0);
 190         flush_workqueue(ccw_device_work);
 191         return 0;
 192 out_err:
 193         if (ccw_device_work)
 194                 destroy_workqueue(ccw_device_work);
 195         if (ccw_device_notify_work)
 196                 destroy_workqueue(ccw_device_notify_work);
 197         if (slow_path_wq)
 198                 destroy_workqueue(slow_path_wq);
 199         return ret;
 200 }
 201
 202 static void __exit
 203 cleanup_ccw_bus_type (void)
 204 {
 205         css_driver_unregister(&io_subchannel_driver);
 206         bus_unregister(&ccw_bus_type);
 207         destroy_workqueue(ccw_device_notify_work);
 208         destroy_workqueue(ccw_device_work);
 209 }
 210
 211 subsys_initcall(init_ccw_bus_type);
 212 module_exit(cleanup_ccw_bus_type);
 213
 214 /************************ device handling **************************/
 215
 216 /*
 217  * A ccw_device has some interfaces in sysfs in addition to the
 218  * standard ones.
 219  * The following entries are designed to export the information which
 220  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 221  * are obvious, so they don't have an entry :)
 222  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 223  */
 224 static ssize_t
 225 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 226 {
 227         struct subchannel *sch = to_subchannel(dev);
 228         struct chsc_ssd_info *ssd = &sch->ssd_info;
 229         ssize_t ret = 0;
 230         int chp;
 231         int mask;
 232
 233         for (chp = 0; chp < 8; chp++) {
 234                 mask = 0x80 >> chp;
 235                 if (ssd->path_mask & mask)
 236                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 237                 else
 238                         ret += sprintf(buf + ret, "00 ");
 239         }
 240         ret += sprintf (buf+ret, "\n");
 241         return min((ssize_t)PAGE_SIZE, ret);
 242 }
 243
 244 static ssize_t
 245 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 246 {
 247         struct subchannel *sch = to_subchannel(dev);
 248         struct pmcw *pmcw = &sch->schib.pmcw;
 249
 250         return sprintf (buf, "%02x %02x %02x\n",
 251                         pmcw->pim, pmcw->pam, pmcw->pom);
 252 }
 253
 254 static ssize_t
 255 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 256 {
 257         struct ccw_device *cdev = to_ccwdev(dev);
 258         struct ccw_device_id *id = &(cdev->id);
 259
 260         if (id->dev_type != 0)
 261                 return sprintf(buf, "%04x/%02x\n",
 262                                 id->dev_type, id->dev_model);
 263         else
 264                 return sprintf(buf, "n/a\n");
 265 }
 266
 267 static ssize_t
 268 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 269 {
 270         struct ccw_device *cdev = to_ccwdev(dev);
 271         struct ccw_device_id *id = &(cdev->id);
 272
 273         return sprintf(buf, "%04x/%02x\n",
 274                        id->cu_type, id->cu_model);
 275 }
 276
 277 static ssize_t
 278 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 279 {
 280         struct ccw_device *cdev = to_ccwdev(dev);
 281         struct ccw_device_id *id = &(cdev->id);
 282         int len;
 283
 284         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 285
 286         return len > PAGE_SIZE ? PAGE_SIZE : len;
 287 }
 288
 289 static ssize_t
 290 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 291 {
 292         struct ccw_device *cdev = to_ccwdev(dev);
 293
 294         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 295 }
 296
 297 int ccw_device_is_orphan(struct ccw_device *cdev)
 298 {
 299         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 300 }
 301
 302 static void ccw_device_unregister(struct ccw_device *cdev)
 303 {
 304         if (test_and_clear_bit(1, &cdev->private->registered))
 305                 device_del(&cdev->dev);
 306 }
 307
 308 static void ccw_device_remove_orphan_cb(struct device *dev)
 309 {
 310         struct ccw_device *cdev = to_ccwdev(dev);
 311
 312         ccw_device_unregister(cdev);
 313         put_device(&cdev->dev);
 314 }
 315
 316 static void ccw_device_remove_sch_cb(struct device *dev)
 317 {
 318         struct subchannel *sch;
 319
 320         sch = to_subchannel(dev);
 321         css_sch_device_unregister(sch);
 322         /* Reset intparm to zeroes. */
 323         sch->schib.pmcw.intparm = 0;
 324         cio_modify(sch);
 325         put_device(&sch->dev);
 326 }
 327
 328 static void
 329 ccw_device_remove_disconnected(struct ccw_device *cdev)
 330 {
 331         unsigned long flags;
 332         int rc;
 333
 334         /*
 335          * Forced offline in disconnected state means
 336          * 'throw away device'.
 337          */
 338         if (ccw_device_is_orphan(cdev)) {
 339                 /*
 340                  * Deregister ccw device.
 341                  * Unfortunately, we cannot do this directly from the
 342                  * attribute method.
 343                  */
 344                 spin_lock_irqsave(cdev->ccwlock, flags);
 345                 cdev->private->state = DEV_STATE_NOT_OPER;
 346                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 347                 rc = device_schedule_callback(&cdev->dev,
 348                                               ccw_device_remove_orphan_cb);
 349                 if (rc)
 350                         CIO_MSG_EVENT(0, "Couldn't unregister orphan "
 351                                       "0.%x.%04x\n",
 352                                       cdev->private->dev_id.ssid,
 353                                       cdev->private->dev_id.devno);
 354                 return;
 355         }
 356         /* Deregister subchannel, which will kill the ccw device. */
 357         rc = device_schedule_callback(cdev->dev.parent,
 358                                       ccw_device_remove_sch_cb);
 359         if (rc)
 360                 CIO_MSG_EVENT(0, "Couldn't unregister disconnected device "
 361                               "0.%x.%04x\n",
 362                               cdev->private->dev_id.ssid,
 363                               cdev->private->dev_id.devno);
 364 }
 365
 366 /**
 367  * ccw_device_set_offline() - disable a ccw device for I/O
 368  * @cdev: target ccw device
 369  *
 370  * This function calls the driver's set_offline() function for @cdev, if
 371  * given, and then disables @cdev.
 372  * Returns:
 373  *   %0 on success and a negative error value on failure.
 374  * Context:
 375  *  enabled, ccw device lock not held
 376  */
 377 int ccw_device_set_offline(struct ccw_device *cdev)
 378 {
 379         int ret;
 380
 381         if (!cdev)
 382                 return -ENODEV;
 383         if (!cdev->online || !cdev->drv)
 384                 return -EINVAL;
 385
 386         if (cdev->drv->set_offline) {
 387                 ret = cdev->drv->set_offline(cdev);
 388                 if (ret != 0)
 389                         return ret;
 390         }
 391         cdev->online = 0;
 392         spin_lock_irq(cdev->ccwlock);
 393         ret = ccw_device_offline(cdev);
 394         if (ret == -ENODEV) {
 395                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 396                         cdev->private->state = DEV_STATE_OFFLINE;
 397                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 398                 }
 399                 spin_unlock_irq(cdev->ccwlock);
 400                 return ret;
 401         }
 402         spin_unlock_irq(cdev->ccwlock);
 403         if (ret == 0)
 404                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 405         else {
 406                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 407                               "device 0.%x.%04x\n",
 408                               ret, cdev->private->dev_id.ssid,
 409                               cdev->private->dev_id.devno);
 410                 cdev->online = 1;
 411         }
 412         return ret;
 413 }
 414
 415 /**
 416  * ccw_device_set_online() - enable a ccw device for I/O
 417  * @cdev: target ccw device
 418  *
 419  * This function first enables @cdev and then calls the driver's set_online()
 420  * function for @cdev, if given. If set_online() returns an error, @cdev is
 421  * disabled again.
 422  * Returns:
 423  *   %0 on success and a negative error value on failure.
 424  * Context:
 425  *  enabled, ccw device lock not held
 426  */
 427 int ccw_device_set_online(struct ccw_device *cdev)
 428 {
 429         int ret;
 430
 431         if (!cdev)
 432                 return -ENODEV;
 433         if (cdev->online || !cdev->drv)
 434                 return -EINVAL;
 435
 436         spin_lock_irq(cdev->ccwlock);
 437         ret = ccw_device_online(cdev);
 438         spin_unlock_irq(cdev->ccwlock);
 439         if (ret == 0)
 440                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 441         else {
 442                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 443                               "device 0.%x.%04x\n",
 444                               ret, cdev->private->dev_id.ssid,
 445                               cdev->private->dev_id.devno);
 446                 return ret;
 447         }
 448         if (cdev->private->state != DEV_STATE_ONLINE)
 449                 return -ENODEV;
 450         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 451                 cdev->online = 1;
 452                 return 0;
 453         }
 454         spin_lock_irq(cdev->ccwlock);
 455         ret = ccw_device_offline(cdev);
 456         spin_unlock_irq(cdev->ccwlock);
 457         if (ret == 0)
 458                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 459         else
 460                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 461                               "device 0.%x.%04x\n",
 462                               ret, cdev->private->dev_id.ssid,
 463                               cdev->private->dev_id.devno);
 464         return (ret == 0) ? -ENODEV : ret;
 465 }
 466
 467 static void online_store_handle_offline(struct ccw_device *cdev)
 468 {
 469         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 470                 ccw_device_remove_disconnected(cdev);
 471         else if (cdev->drv && cdev->drv->set_offline)
 472                 ccw_device_set_offline(cdev);
 473 }
 474
 475 static int online_store_recog_and_online(struct ccw_device *cdev)
 476 {
 477         int ret;
 478
 479         /* Do device recognition, if needed. */
 480         if (cdev->id.cu_type == 0) {
 481                 ret = ccw_device_recognition(cdev);
 482                 if (ret) {
 483                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 484                                       "for device 0.%x.%04x (ret=%d)\n",
 485                                       cdev->private->dev_id.ssid,
 486                                       cdev->private->dev_id.devno, ret);
 487                         return ret;
 488                 }
 489                 wait_event(cdev->private->wait_q,
 490                            cdev->private->flags.recog_done);
 491         }
 492         if (cdev->drv && cdev->drv->set_online)
 493                 ccw_device_set_online(cdev);
 494         return 0;
 495 }
 496 static void online_store_handle_online(struct ccw_device *cdev, int force)
 497 {
 498         int ret;
 499
 500         ret = online_store_recog_and_online(cdev);
 501         if (ret)
 502                 return;
 503         if (force && cdev->private->state == DEV_STATE_BOXED) {
 504                 ret = ccw_device_stlck(cdev);
 505                 if (ret) {
 506                         dev_warn(&cdev->dev,
 507                                  "ccw_device_stlck returned %d!\n", ret);
 508                         return;
 509                 }
 510                 if (cdev->id.cu_type == 0)
 511                         cdev->private->state = DEV_STATE_NOT_OPER;
 512                 online_store_recog_and_online(cdev);
 513         }
 514
 515 }
 516
 517 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 518                              const char *buf, size_t count)
 519 {
 520         struct ccw_device *cdev = to_ccwdev(dev);
 521         int force, ret;
 522         unsigned long i;
 523
 524         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 525                 return -EAGAIN;
 526
 527         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 528                 atomic_set(&cdev->private->onoff, 0);
 529                 return -EINVAL;
 530         }
 531         if (!strncmp(buf, "force\n", count)) {
 532                 force = 1;
 533                 i = 1;
 534                 ret = 0;
 535         } else {
 536                 force = 0;
 537                 ret = strict_strtoul(buf, 16, &i);
 538         }
 539         if (ret)
 540                 goto out;
 541         switch (i) {
 542         case 0:
 543                 online_store_handle_offline(cdev);
 544                 ret = count;
 545                 break;
 546         case 1:
 547                 online_store_handle_online(cdev, force);
 548                 ret = count;
 549                 break;
 550         default:
 551                 ret = -EINVAL;
 552         }
 553 out:
 554         if (cdev->drv)
 555                 module_put(cdev->drv->owner);
 556         atomic_set(&cdev->private->onoff, 0);
 557         return ret;
 558 }
 559
 560 static ssize_t
 561 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 562 {
 563         struct ccw_device *cdev = to_ccwdev(dev);
 564         struct subchannel *sch;
 565
 566         if (ccw_device_is_orphan(cdev))
 567                 return sprintf(buf, "no device\n");
 568         switch (cdev->private->state) {
 569         case DEV_STATE_BOXED:
 570                 return sprintf(buf, "boxed\n");
 571         case DEV_STATE_DISCONNECTED:
 572         case DEV_STATE_DISCONNECTED_SENSE_ID:
 573         case DEV_STATE_NOT_OPER:
 574                 sch = to_subchannel(dev->parent);
 575                 if (!sch->lpm)
 576                         return sprintf(buf, "no path\n");
 577                 else
 578                         return sprintf(buf, "no device\n");
 579         default:
 580                 /* All other states considered fine. */
 581                 return sprintf(buf, "good\n");
 582         }
 583 }
 584
 585 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 586 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 587 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 588 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 589 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 590 static DEVICE_ATTR(online, 0644, online_show, online_store);
 591 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 592
 593 static struct attribute *io_subchannel_attrs[] = {
 594         &dev_attr_chpids.attr,
 595         &dev_attr_pimpampom.attr,
 596         NULL,
 597 };
 598
 599 static struct attribute_group io_subchannel_attr_group = {
 600         .attrs = io_subchannel_attrs,
 601 };
 602
 603 static struct attribute * ccwdev_attrs[] = {
 604         &dev_attr_devtype.attr,
 605         &dev_attr_cutype.attr,
 606         &dev_attr_modalias.attr,
 607         &dev_attr_online.attr,
 608         &dev_attr_cmb_enable.attr,
 609         &dev_attr_availability.attr,
 610         NULL,
 611 };
 612
 613 static struct attribute_group ccwdev_attr_group = {
 614         .attrs = ccwdev_attrs,
 615 };
 616
 617 static struct attribute_group *ccwdev_attr_groups[] = {
 618         &ccwdev_attr_group,
 619         NULL,
 620 };
 621
 622 /* this is a simple abstraction for device_register that sets the
 623  * correct bus type and adds the bus specific files */
 624 static int ccw_device_register(struct ccw_device *cdev)
 625 {
 626         struct device *dev = &cdev->dev;
 627         int ret;
 628
 629         dev->bus = &ccw_bus_type;
 630
 631         if ((ret = device_add(dev)))
 632                 return ret;
 633
 634         set_bit(1, &cdev->private->registered);
 635         return ret;
 636 }
 637
 638 struct match_data {
 639         struct ccw_dev_id dev_id;
 640         struct ccw_device * sibling;
 641 };
 642
 643 static int
 644 match_devno(struct device * dev, void * data)
 645 {
 646         struct match_data * d = data;
 647         struct ccw_device * cdev;
 648
 649         cdev = to_ccwdev(dev);
 650         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 651             !ccw_device_is_orphan(cdev) &&
 652             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 653             (cdev != d->sibling))
 654                 return 1;
 655         return 0;
 656 }
 657
 658 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 659                                                      struct ccw_device *sibling)
 660 {
 661         struct device *dev;
 662         struct match_data data;
 663
 664         data.dev_id = *dev_id;
 665         data.sibling = sibling;
 666         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 667
 668         return dev ? to_ccwdev(dev) : NULL;
 669 }
 670
 671 static int match_orphan(struct device *dev, void *data)
 672 {
 673         struct ccw_dev_id *dev_id;
 674         struct ccw_device *cdev;
 675
 676         dev_id = data;
 677         cdev = to_ccwdev(dev);
 678         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 679 }
 680
 681 static struct ccw_device *
 682 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 683                               struct ccw_dev_id *dev_id)
 684 {
 685         struct device *dev;
 686
 687         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 688                                 match_orphan);
 689
 690         return dev ? to_ccwdev(dev) : NULL;
 691 }
 692
 693 static void
 694 ccw_device_add_changed(struct work_struct *work)
 695 {
 696         struct ccw_device_private *priv;
 697         struct ccw_device *cdev;
 698
 699         priv = container_of(work, struct ccw_device_private, kick_work);
 700         cdev = priv->cdev;
 701         if (device_add(&cdev->dev)) {
 702                 put_device(&cdev->dev);
 703                 return;
 704         }
 705         set_bit(1, &cdev->private->registered);
 706 }
 707
 708 void ccw_device_do_unreg_rereg(struct work_struct *work)
 709 {
 710         struct ccw_device_private *priv;
 711         struct ccw_device *cdev;
 712         struct subchannel *sch;
 713
 714         priv = container_of(work, struct ccw_device_private, kick_work);
 715         cdev = priv->cdev;
 716         sch = to_subchannel(cdev->dev.parent);
 717
 718         ccw_device_unregister(cdev);
 719         PREPARE_WORK(&cdev->private->kick_work,
 720                      ccw_device_add_changed);
 721         queue_work(ccw_device_work, &cdev->private->kick_work);
 722 }
 723
 724 static void
 725 ccw_device_release(struct device *dev)
 726 {
 727         struct ccw_device *cdev;
 728
 729         cdev = to_ccwdev(dev);
 730         kfree(cdev->private);
 731         kfree(cdev);
 732 }
 733
 734 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 735 {
 736         struct ccw_device *cdev;
 737
 738         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 739         if (cdev) {
 740                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 741                                         GFP_KERNEL | GFP_DMA);
 742                 if (cdev->private)
 743                         return cdev;
 744         }
 745         kfree(cdev);
 746         return ERR_PTR(-ENOMEM);
 747 }
 748
 749 static int io_subchannel_initialize_dev(struct subchannel *sch,
 750                                         struct ccw_device *cdev)
 751 {
 752         cdev->private->cdev = cdev;
 753         atomic_set(&cdev->private->onoff, 0);
 754         cdev->dev.parent = &sch->dev;
 755         cdev->dev.release = ccw_device_release;
 756         INIT_WORK(&cdev->private->kick_work, NULL);
 757         cdev->dev.groups = ccwdev_attr_groups;
 758         /* Do first half of device_register. */
 759         device_initialize(&cdev->dev);
 760         if (!get_device(&sch->dev)) {
 761                 if (cdev->dev.release)
 762                         cdev->dev.release(&cdev->dev);
 763                 return -ENODEV;
 764         }
 765         return 0;
 766 }
 767
 768 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 769 {
 770         struct ccw_device *cdev;
 771         int ret;
 772
 773         cdev = io_subchannel_allocate_dev(sch);
 774         if (!IS_ERR(cdev)) {
 775                 ret = io_subchannel_initialize_dev(sch, cdev);
 776                 if (ret) {
 777                         kfree(cdev);
 778                         cdev = ERR_PTR(ret);
 779                 }
 780         }
 781         return cdev;
 782 }
 783
 784 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 785
 786 static void sch_attach_device(struct subchannel *sch,
 787                               struct ccw_device *cdev)
 788 {
 789         css_update_ssd_info(sch);
 790         spin_lock_irq(sch->lock);
 791         sch_set_cdev(sch, cdev);
 792         cdev->private->schid = sch->schid;
 793         cdev->ccwlock = sch->lock;
 794         ccw_device_trigger_reprobe(cdev);
 795         spin_unlock_irq(sch->lock);
 796 }
 797
 798 static void sch_attach_disconnected_device(struct subchannel *sch,
 799                                            struct ccw_device *cdev)
 800 {
 801         struct subchannel *other_sch;
 802         int ret;
 803
 804         other_sch = to_subchannel(get_device(cdev->dev.parent));
 805         ret = device_move(&cdev->dev, &sch->dev);
 806         if (ret) {
 807                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 808                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 809                               cdev->private->dev_id.devno, ret);
 810                 put_device(&other_sch->dev);
 811                 return;
 812         }
 813         sch_set_cdev(other_sch, NULL);
 814         /* No need to keep a subchannel without ccw device around. */
 815         css_sch_device_unregister(other_sch);
 816         put_device(&other_sch->dev);
 817         sch_attach_device(sch, cdev);
 818 }
 819
 820 static void sch_attach_orphaned_device(struct subchannel *sch,
 821                                        struct ccw_device *cdev)
 822 {
 823         int ret;
 824
 825         /* Try to move the ccw device to its new subchannel. */
 826         ret = device_move(&cdev->dev, &sch->dev);
 827         if (ret) {
 828                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 829                               "failed (ret=%d)!\n",
 830                               cdev->private->dev_id.ssid,
 831                               cdev->private->dev_id.devno, ret);
 832                 return;
 833         }
 834         sch_attach_device(sch, cdev);
 835 }
 836
 837 static void sch_create_and_recog_new_device(struct subchannel *sch)
 838 {
 839         struct ccw_device *cdev;
 840
 841         /* Need to allocate a new ccw device. */
 842         cdev = io_subchannel_create_ccwdev(sch);
 843         if (IS_ERR(cdev)) {
 844                 /* OK, we did everything we could... */
 845                 css_sch_device_unregister(sch);
 846                 return;
 847         }
 848         spin_lock_irq(sch->lock);
 849         sch_set_cdev(sch, cdev);
 850         spin_unlock_irq(sch->lock);
 851         /* Start recognition for the new ccw device. */
 852         if (io_subchannel_recog(cdev, sch)) {
 853                 spin_lock_irq(sch->lock);
 854                 sch_set_cdev(sch, NULL);
 855                 spin_unlock_irq(sch->lock);
 856                 if (cdev->dev.release)
 857                         cdev->dev.release(&cdev->dev);
 858                 css_sch_device_unregister(sch);
 859         }
 860 }
 861
 862
 863 void ccw_device_move_to_orphanage(struct work_struct *work)
 864 {
 865         struct ccw_device_private *priv;
 866         struct ccw_device *cdev;
 867         struct ccw_device *replacing_cdev;
 868         struct subchannel *sch;
 869         int ret;
 870         struct channel_subsystem *css;
 871         struct ccw_dev_id dev_id;
 872
 873         priv = container_of(work, struct ccw_device_private, kick_work);
 874         cdev = priv->cdev;
 875         sch = to_subchannel(cdev->dev.parent);
 876         css = to_css(sch->dev.parent);
 877         dev_id.devno = sch->schib.pmcw.dev;
 878         dev_id.ssid = sch->schid.ssid;
 879
 880         /*
 881          * Move the orphaned ccw device to the orphanage so the replacing
 882          * ccw device can take its place on the subchannel.
 883          */
 884         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 885         if (ret) {
 886                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 887                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 888                               cdev->private->dev_id.devno, ret);
 889                 return;
 890         }
 891         cdev->ccwlock = css->pseudo_subchannel->lock;
 892         /*
 893          * Search for the replacing ccw device
 894          * - among the disconnected devices
 895          * - in the orphanage
 896          */
 897         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 898         if (replacing_cdev) {
 899                 sch_attach_disconnected_device(sch, replacing_cdev);
 900                 return;
 901         }
 902         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 903         if (replacing_cdev) {
 904                 sch_attach_orphaned_device(sch, replacing_cdev);
 905                 return;
 906         }
 907         sch_create_and_recog_new_device(sch);
 908 }
 909
 910 /*
 911  * Register recognized device.
 912  */
 913 static void
 914 io_subchannel_register(struct work_struct *work)
 915 {
 916         struct ccw_device_private *priv;
 917         struct ccw_device *cdev;
 918         struct subchannel *sch;
 919         int ret;
 920         unsigned long flags;
 921
 922         priv = container_of(work, struct ccw_device_private, kick_work);
 923         cdev = priv->cdev;
 924         sch = to_subchannel(cdev->dev.parent);
 925         css_update_ssd_info(sch);
 926         /*
 927          * io_subchannel_register() will also be called after device
 928          * recognition has been done for a boxed device (which will already
 929          * be registered). We need to reprobe since we may now have sense id
 930          * information.
 931          */
 932         if (klist_node_attached(&cdev->dev.knode_parent)) {
 933                 if (!cdev->drv) {
 934                         ret = device_reprobe(&cdev->dev);
 935                         if (ret)
 936                                 /* We can't do much here. */
 937                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 938                                               " %d for 0.%x.%04x\n", ret,
 939                                               cdev->private->dev_id.ssid,
 940                                               cdev->private->dev_id.devno);
 941                 }
 942                 goto out;
 943         }
 944         /*
 945          * Now we know this subchannel will stay, we can throw
 946          * our delayed uevent.
 947          */
 948         sch->dev.uevent_suppress = 0;
 949         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 950         /* make it known to the system */
 951         ret = ccw_device_register(cdev);
 952         if (ret) {
 953                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 954                               cdev->private->dev_id.ssid,
 955                               cdev->private->dev_id.devno, ret);
 956                 put_device(&cdev->dev);
 957                 spin_lock_irqsave(sch->lock, flags);
 958                 sch_set_cdev(sch, NULL);
 959                 spin_unlock_irqrestore(sch->lock, flags);
 960                 kfree (cdev->private);
 961                 kfree (cdev);
 962                 put_device(&sch->dev);
 963                 if (atomic_dec_and_test(&ccw_device_init_count))
 964                         wake_up(&ccw_device_init_wq);
 965                 return;
 966         }
 967         put_device(&cdev->dev);
 968 out:
 969         cdev->private->flags.recog_done = 1;
 970         put_device(&sch->dev);
 971         wake_up(&cdev->private->wait_q);
 972         if (atomic_dec_and_test(&ccw_device_init_count))
 973                 wake_up(&ccw_device_init_wq);
 974 }
 975
 976 static void ccw_device_call_sch_unregister(struct work_struct *work)
 977 {
 978         struct ccw_device_private *priv;
 979         struct ccw_device *cdev;
 980         struct subchannel *sch;
 981
 982         priv = container_of(work, struct ccw_device_private, kick_work);
 983         cdev = priv->cdev;
 984         sch = to_subchannel(cdev->dev.parent);
 985         css_sch_device_unregister(sch);
 986         /* Reset intparm to zeroes. */
 987         sch->schib.pmcw.intparm = 0;
 988         cio_modify(sch);
 989         put_device(&cdev->dev);
 990         put_device(&sch->dev);
 991 }
 992
 993 /*
 994  * subchannel recognition done. Called from the state machine.
 995  */
 996 void
 997 io_subchannel_recog_done(struct ccw_device *cdev)
 998 {
 999         struct subchannel *sch;
1000
1001         if (css_init_done == 0) {
1002                 cdev->private->flags.recog_done = 1;
1003                 return;
1004         }
1005         switch (cdev->private->state) {
1006         case DEV_STATE_NOT_OPER:
1007                 cdev->private->flags.recog_done = 1;
1008                 /* Remove device found not operational. */
1009                 if (!get_device(&cdev->dev))
1010                         break;
1011                 sch = to_subchannel(cdev->dev.parent);
1012                 PREPARE_WORK(&cdev->private->kick_work,
1013                              ccw_device_call_sch_unregister);
1014                 queue_work(slow_path_wq, &cdev->private->kick_work);
1015                 if (atomic_dec_and_test(&ccw_device_init_count))
1016                         wake_up(&ccw_device_init_wq);
1017                 break;
1018         case DEV_STATE_BOXED:
1019                 /* Device did not respond in time. */
1020         case DEV_STATE_OFFLINE:
1021                 /*
1022                  * We can't register the device in interrupt context so
1023                  * we schedule a work item.
1024                  */
1025                 if (!get_device(&cdev->dev))
1026                         break;
1027                 PREPARE_WORK(&cdev->private->kick_work,
1028                              io_subchannel_register);
1029                 queue_work(slow_path_wq, &cdev->private->kick_work);
1030                 break;
1031         }
1032 }
1033
1034 static int
1035 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1036 {
1037         int rc;
1038         struct ccw_device_private *priv;
1039
1040         sch_set_cdev(sch, cdev);
1041         cdev->ccwlock = sch->lock;
1042
1043         /* Init private data. */
1044         priv = cdev->private;
1045         priv->dev_id.devno = sch->schib.pmcw.dev;
1046         priv->dev_id.ssid = sch->schid.ssid;
1047         priv->schid = sch->schid;
1048         priv->state = DEV_STATE_NOT_OPER;
1049         INIT_LIST_HEAD(&priv->cmb_list);
1050         init_waitqueue_head(&priv->wait_q);
1051         init_timer(&priv->timer);
1052
1053         /* Set an initial name for the device. */
1054         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1055                   sch->schid.ssid, sch->schib.pmcw.dev);
1056
1057         /* Increase counter of devices currently in recognition. */
1058         atomic_inc(&ccw_device_init_count);
1059
1060         /* Start async. device sensing. */
1061         spin_lock_irq(sch->lock);
1062         rc = ccw_device_recognition(cdev);
1063         spin_unlock_irq(sch->lock);
1064         if (rc) {
1065                 if (atomic_dec_and_test(&ccw_device_init_count))
1066                         wake_up(&ccw_device_init_wq);
1067         }
1068         return rc;
1069 }
1070
1071 static void ccw_device_move_to_sch(struct work_struct *work)
1072 {
1073         struct ccw_device_private *priv;
1074         int rc;
1075         struct subchannel *sch;
1076         struct ccw_device *cdev;
1077         struct subchannel *former_parent;
1078
1079         priv = container_of(work, struct ccw_device_private, kick_work);
1080         sch = priv->sch;
1081         cdev = priv->cdev;
1082         former_parent = ccw_device_is_orphan(cdev) ?
1083                 NULL : to_subchannel(get_device(cdev->dev.parent));
1084         mutex_lock(&sch->reg_mutex);
1085         /* Try to move the ccw device to its new subchannel. */
1086         rc = device_move(&cdev->dev, &sch->dev);
1087         mutex_unlock(&sch->reg_mutex);
1088         if (rc) {
1089                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1090                               "0.%x.%04x failed (ret=%d)!\n",
1091                               cdev->private->dev_id.ssid,
1092                               cdev->private->dev_id.devno, sch->schid.ssid,
1093                               sch->schid.sch_no, rc);
1094                 css_sch_device_unregister(sch);
1095                 goto out;
1096         }
1097         if (former_parent) {
1098                 spin_lock_irq(former_parent->lock);
1099                 sch_set_cdev(former_parent, NULL);
1100                 spin_unlock_irq(former_parent->lock);
1101                 css_sch_device_unregister(former_parent);
1102                 /* Reset intparm to zeroes. */
1103                 former_parent->schib.pmcw.intparm = 0;
1104                 cio_modify(former_parent);
1105         }
1106         sch_attach_device(sch, cdev);
1107 out:
1108         if (former_parent)
1109                 put_device(&former_parent->dev);
1110         put_device(&cdev->dev);
1111 }
1112
1113 static void io_subchannel_irq(struct subchannel *sch)
1114 {
1115         struct ccw_device *cdev;
1116
1117         cdev = sch_get_cdev(sch);
1118
1119         CIO_TRACE_EVENT(3, "IRQ");
1120         CIO_TRACE_EVENT(3, sch->dev.bus_id);
1121         if (cdev)
1122                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1123 }
1124
1125 static void io_subchannel_init_fields(struct subchannel *sch)
1126 {
1127         if (cio_is_console(sch->schid))
1128                 sch->opm = 0xff;
1129         else
1130                 sch->opm = chp_get_sch_opm(sch);
1131         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1132         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1133
1134         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1135                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1136                       sch->schib.pmcw.dev, sch->schid.ssid,
1137                       sch->schid.sch_no, sch->schib.pmcw.pim,
1138                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1139         /* Initially set up some fields in the pmcw. */
1140         sch->schib.pmcw.ena = 0;
1141         sch->schib.pmcw.csense = 1;     /* concurrent sense */
1142         if ((sch->lpm & (sch->lpm - 1)) != 0)
1143                 sch->schib.pmcw.mp = 1; /* multipath mode */
1144         /* clean up possible residual cmf stuff */
1145         sch->schib.pmcw.mme = 0;
1146         sch->schib.pmcw.mbfc = 0;
1147         sch->schib.pmcw.mbi = 0;
1148         sch->schib.mba = 0;
1149 }
1150
1151 static int io_subchannel_probe(struct subchannel *sch)
1152 {
1153         struct ccw_device *cdev;
1154         int rc;
1155         unsigned long flags;
1156         struct ccw_dev_id dev_id;
1157
1158         cdev = sch_get_cdev(sch);
1159         if (cdev) {
1160                 rc = sysfs_create_group(&sch->dev.kobj,
1161                                         &io_subchannel_attr_group);
1162                 if (rc)
1163                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1164                                       "attributes for subchannel "
1165                                       "0.%x.%04x (rc=%d)\n",
1166                                       sch->schid.ssid, sch->schid.sch_no, rc);
1167                 /*
1168                  * This subchannel already has an associated ccw_device.
1169                  * Throw the delayed uevent for the subchannel, register
1170                  * the ccw_device and exit. This happens for all early
1171                  * devices, e.g. the console.
1172                  */
1173                 sch->dev.uevent_suppress = 0;
1174                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1175                 cdev->dev.groups = ccwdev_attr_groups;
1176                 device_initialize(&cdev->dev);
1177                 ccw_device_register(cdev);
1178                 /*
1179                  * Check if the device is already online. If it is
1180                  * the reference count needs to be corrected
1181                  * (see ccw_device_online and css_init_done for the
1182                  * ugly details).
1183                  */
1184                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1185                     cdev->private->state != DEV_STATE_OFFLINE &&
1186                     cdev->private->state != DEV_STATE_BOXED)
1187                         get_device(&cdev->dev);
1188                 return 0;
1189         }
1190         io_subchannel_init_fields(sch);
1191         /*
1192          * First check if a fitting device may be found amongst the
1193          * disconnected devices or in the orphanage.
1194          */
1195         dev_id.devno = sch->schib.pmcw.dev;
1196         dev_id.ssid = sch->schid.ssid;
1197         rc = sysfs_create_group(&sch->dev.kobj,
1198                                 &io_subchannel_attr_group);
1199         if (rc)
1200                 return rc;
1201         /* Allocate I/O subchannel private data. */
1202         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1203                                GFP_KERNEL | GFP_DMA);
1204         if (!sch->private) {
1205                 rc = -ENOMEM;
1206                 goto out_err;
1207         }
1208         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1209         if (!cdev)
1210                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1211                                                      &dev_id);
1212         if (cdev) {
1213                 /*
1214                  * Schedule moving the device until when we have a registered
1215                  * subchannel to move to and succeed the probe. We can
1216                  * unregister later again, when the probe is through.
1217                  */
1218                 cdev->private->sch = sch;
1219                 PREPARE_WORK(&cdev->private->kick_work,
1220                              ccw_device_move_to_sch);
1221                 queue_work(slow_path_wq, &cdev->private->kick_work);
1222                 return 0;
1223         }
1224         cdev = io_subchannel_create_ccwdev(sch);
1225         if (IS_ERR(cdev)) {
1226                 rc = PTR_ERR(cdev);
1227                 goto out_err;
1228         }
1229         rc = io_subchannel_recog(cdev, sch);
1230         if (rc) {
1231                 spin_lock_irqsave(sch->lock, flags);
1232                 sch_set_cdev(sch, NULL);
1233                 spin_unlock_irqrestore(sch->lock, flags);
1234                 if (cdev->dev.release)
1235                         cdev->dev.release(&cdev->dev);
1236                 goto out_err;
1237         }
1238         return 0;
1239 out_err:
1240         kfree(sch->private);
1241         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1242         return rc;
1243 }
1244
1245 static int
1246 io_subchannel_remove (struct subchannel *sch)
1247 {
1248         struct ccw_device *cdev;
1249         unsigned long flags;
1250
1251         cdev = sch_get_cdev(sch);
1252         if (!cdev)
1253                 return 0;
1254         /* Set ccw device to not operational and drop reference. */
1255         spin_lock_irqsave(cdev->ccwlock, flags);
1256         sch_set_cdev(sch, NULL);
1257         cdev->private->state = DEV_STATE_NOT_OPER;
1258         spin_unlock_irqrestore(cdev->ccwlock, flags);
1259         ccw_device_unregister(cdev);
1260         put_device(&cdev->dev);
1261         kfree(sch->private);
1262         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1263         return 0;
1264 }
1265
1266 static int io_subchannel_notify(struct subchannel *sch, int event)
1267 {
1268         struct ccw_device *cdev;
1269
1270         cdev = sch_get_cdev(sch);
1271         if (!cdev)
1272                 return 0;
1273         return ccw_device_notify(cdev, event);
1274 }
1275
1276 static void io_subchannel_verify(struct subchannel *sch)
1277 {
1278         struct ccw_device *cdev;
1279
1280         cdev = sch_get_cdev(sch);
1281         if (cdev)
1282                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1283 }
1284
1285 static int check_for_io_on_path(struct subchannel *sch, int mask)
1286 {
1287         int cc;
1288
1289         cc = stsch(sch->schid, &sch->schib);
1290         if (cc)
1291                 return 0;
1292         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1293                 return 1;
1294         return 0;
1295 }
1296
1297 static void terminate_internal_io(struct subchannel *sch,
1298                                   struct ccw_device *cdev)
1299 {
1300         if (cio_clear(sch)) {
1301                 /* Recheck device in case clear failed. */
1302                 sch->lpm = 0;
1303                 if (cdev->online)
1304                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1305                 else
1306                         css_schedule_eval(sch->schid);
1307                 return;
1308         }
1309         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1310         /* Request retry of internal operation. */
1311         cdev->private->flags.intretry = 1;
1312         /* Call handler. */
1313         if (cdev->handler)
1314                 cdev->handler(cdev, cdev->private->intparm,
1315                               ERR_PTR(-EIO));
1316 }
1317
1318 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1319 {
1320         struct ccw_device *cdev;
1321
1322         cdev = sch_get_cdev(sch);
1323         if (!cdev)
1324                 return;
1325         if (check_for_io_on_path(sch, mask)) {
1326                 if (cdev->private->state == DEV_STATE_ONLINE)
1327                         ccw_device_kill_io(cdev);
1328                 else {
1329                         terminate_internal_io(sch, cdev);
1330                         /* Re-start path verification. */
1331                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1332                 }
1333         } else
1334                 /* trigger path verification. */
1335                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1336
1337 }
1338
1339 static int io_subchannel_chp_event(struct subchannel *sch,
1340                                    struct chp_link *link, int event)
1341 {
1342         int mask;
1343
1344         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1345         if (!mask)
1346                 return 0;
1347         switch (event) {
1348         case CHP_VARY_OFF:
1349                 sch->opm &= ~mask;
1350                 sch->lpm &= ~mask;
1351                 io_subchannel_terminate_path(sch, mask);
1352                 break;
1353         case CHP_VARY_ON:
1354                 sch->opm |= mask;
1355                 sch->lpm |= mask;
1356                 io_subchannel_verify(sch);
1357                 break;
1358         case CHP_OFFLINE:
1359                 if (stsch(sch->schid, &sch->schib))
1360                         return -ENXIO;
1361                 if (!css_sch_is_valid(&sch->schib))
1362                         return -ENODEV;
1363                 io_subchannel_terminate_path(sch, mask);
1364                 break;
1365         case CHP_ONLINE:
1366                 if (stsch(sch->schid, &sch->schib))
1367                         return -ENXIO;
1368                 sch->lpm |= mask & sch->opm;
1369                 io_subchannel_verify(sch);
1370                 break;
1371         }
1372         return 0;
1373 }
1374
1375 static void
1376 io_subchannel_shutdown(struct subchannel *sch)
1377 {
1378         struct ccw_device *cdev;
1379         int ret;
1380
1381         cdev = sch_get_cdev(sch);
1382
1383         if (cio_is_console(sch->schid))
1384                 return;
1385         if (!sch->schib.pmcw.ena)
1386                 /* Nothing to do. */
1387                 return;
1388         ret = cio_disable_subchannel(sch);
1389         if (ret != -EBUSY)
1390                 /* Subchannel is disabled, we're done. */
1391                 return;
1392         cdev->private->state = DEV_STATE_QUIESCE;
1393         if (cdev->handler)
1394                 cdev->handler(cdev, cdev->private->intparm,
1395                               ERR_PTR(-EIO));
1396         ret = ccw_device_cancel_halt_clear(cdev);
1397         if (ret == -EBUSY) {
1398                 ccw_device_set_timeout(cdev, HZ/10);
1399                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1400         }
1401         cio_disable_subchannel(sch);
1402 }
1403
1404 static int io_subchannel_get_status(struct subchannel *sch)
1405 {
1406         struct schib schib;
1407
1408         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1409                 return CIO_GONE;
1410         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1411                 return CIO_REVALIDATE;
1412         if (!sch->lpm)
1413                 return CIO_NO_PATH;
1414         return CIO_OPER;
1415 }
1416
1417 static int device_is_disconnected(struct ccw_device *cdev)
1418 {
1419         if (!cdev)
1420                 return 0;
1421         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1422                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1423 }
1424
1425 static int recovery_check(struct device *dev, void *data)
1426 {
1427         struct ccw_device *cdev = to_ccwdev(dev);
1428         int *redo = data;
1429
1430         spin_lock_irq(cdev->ccwlock);
1431         switch (cdev->private->state) {
1432         case DEV_STATE_DISCONNECTED:
1433                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1434                               cdev->private->dev_id.ssid,
1435                               cdev->private->dev_id.devno);
1436                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1437                 *redo = 1;
1438                 break;
1439         case DEV_STATE_DISCONNECTED_SENSE_ID:
1440                 *redo = 1;
1441                 break;
1442         }
1443         spin_unlock_irq(cdev->ccwlock);
1444
1445         return 0;
1446 }
1447
1448 static void recovery_work_func(struct work_struct *unused)
1449 {
1450         int redo = 0;
1451
1452         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1453         if (redo) {
1454                 spin_lock_irq(&recovery_lock);
1455                 if (!timer_pending(&recovery_timer)) {
1456                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1457                                 recovery_phase++;
1458                         mod_timer(&recovery_timer, jiffies +
1459                                   recovery_delay[recovery_phase] * HZ);
1460                 }
1461                 spin_unlock_irq(&recovery_lock);
1462         } else
1463                 CIO_MSG_EVENT(4, "recovery: end\n");
1464 }
1465
1466 static DECLARE_WORK(recovery_work, recovery_work_func);
1467
1468 static void recovery_func(unsigned long data)
1469 {
1470         /*
1471          * We can't do our recovery in softirq context and it's not
1472          * performance critical, so we schedule it.
1473          */
1474         schedule_work(&recovery_work);
1475 }
1476
1477 static void ccw_device_schedule_recovery(void)
1478 {
1479         unsigned long flags;
1480
1481         CIO_MSG_EVENT(4, "recovery: schedule\n");
1482         spin_lock_irqsave(&recovery_lock, flags);
1483         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1484                 recovery_phase = 0;
1485                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1486         }
1487         spin_unlock_irqrestore(&recovery_lock, flags);
1488 }
1489
1490 static void device_set_disconnected(struct ccw_device *cdev)
1491 {
1492         if (!cdev)
1493                 return;
1494         ccw_device_set_timeout(cdev, 0);
1495         cdev->private->flags.fake_irb = 0;
1496         cdev->private->state = DEV_STATE_DISCONNECTED;
1497         if (cdev->online)
1498                 ccw_device_schedule_recovery();
1499 }
1500
1501 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1502 {
1503         int event, ret, disc;
1504         unsigned long flags;
1505         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE } action;
1506         struct ccw_device *cdev;
1507
1508         spin_lock_irqsave(sch->lock, flags);
1509         cdev = sch_get_cdev(sch);
1510         disc = device_is_disconnected(cdev);
1511         if (disc && slow) {
1512                 /* Disconnected devices are evaluated directly only.*/
1513                 spin_unlock_irqrestore(sch->lock, flags);
1514                 return 0;
1515         }
1516         /* No interrupt after machine check - kill pending timers. */
1517         if (cdev)
1518                 ccw_device_set_timeout(cdev, 0);
1519         if (!disc && !slow) {
1520                 /* Non-disconnected devices are evaluated on the slow path. */
1521                 spin_unlock_irqrestore(sch->lock, flags);
1522                 return -EAGAIN;
1523         }
1524         event = io_subchannel_get_status(sch);
1525         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1526                       sch->schid.ssid, sch->schid.sch_no, event,
1527                       disc ? "disconnected" : "normal",
1528                       slow ? "slow" : "fast");
1529         /* Analyze subchannel status. */
1530         action = NONE;
1531         switch (event) {
1532         case CIO_NO_PATH:
1533                 if (disc) {
1534                         /* Check if paths have become available. */
1535                         action = REPROBE;
1536                         break;
1537                 }
1538                 /* fall through */
1539         case CIO_GONE:
1540                 /* Prevent unwanted effects when opening lock. */
1541                 cio_disable_subchannel(sch);
1542                 device_set_disconnected(cdev);
1543                 /* Ask driver what to do with device. */
1544                 action = UNREGISTER;
1545                 spin_unlock_irqrestore(sch->lock, flags);
1546                 ret = io_subchannel_notify(sch, event);
1547                 spin_lock_irqsave(sch->lock, flags);
1548                 if (ret)
1549                         action = NONE;
1550                 break;
1551         case CIO_REVALIDATE:
1552                 /* Device will be removed, so no notify necessary. */
1553                 if (disc)
1554                         /* Reprobe because immediate unregister might block. */
1555                         action = REPROBE;
1556                 else
1557                         action = UNREGISTER_PROBE;
1558                 break;
1559         case CIO_OPER:
1560                 if (disc)
1561                         /* Get device operational again. */
1562                         action = REPROBE;
1563                 break;
1564         }
1565         /* Perform action. */
1566         ret = 0;
1567         switch (action) {
1568         case UNREGISTER:
1569         case UNREGISTER_PROBE:
1570                 /* Unregister device (will use subchannel lock). */
1571                 spin_unlock_irqrestore(sch->lock, flags);
1572                 css_sch_device_unregister(sch);
1573                 spin_lock_irqsave(sch->lock, flags);
1574
1575                 /* Reset intparm to zeroes. */
1576                 sch->schib.pmcw.intparm = 0;
1577                 cio_modify(sch);
1578                 break;
1579         case REPROBE:
1580                 ccw_device_trigger_reprobe(cdev);
1581                 break;
1582         default:
1583                 break;
1584         }
1585         spin_unlock_irqrestore(sch->lock, flags);
1586         /* Probe if necessary. */
1587         if (action == UNREGISTER_PROBE)
1588                 ret = css_probe_device(sch->schid);
1589
1590         return ret;
1591 }
1592
1593 #ifdef CONFIG_CCW_CONSOLE
1594 static struct ccw_device console_cdev;
1595 static struct ccw_device_private console_private;
1596 static int console_cdev_in_use;
1597
1598 static DEFINE_SPINLOCK(ccw_console_lock);
1599
1600 spinlock_t * cio_get_console_lock(void)
1601 {
1602         return &ccw_console_lock;
1603 }
1604
1605 static int ccw_device_console_enable(struct ccw_device *cdev,
1606                                      struct subchannel *sch)
1607 {
1608         int rc;
1609
1610         /* Attach subchannel private data. */
1611         sch->private = cio_get_console_priv();
1612         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1613         io_subchannel_init_fields(sch);
1614         sch->driver = &io_subchannel_driver;
1615         /* Initialize the ccw_device structure. */
1616         cdev->dev.parent= &sch->dev;
1617         rc = io_subchannel_recog(cdev, sch);
1618         if (rc)
1619                 return rc;
1620
1621         /* Now wait for the async. recognition to come to an end. */
1622         spin_lock_irq(cdev->ccwlock);
1623         while (!dev_fsm_final_state(cdev))
1624                 wait_cons_dev();
1625         rc = -EIO;
1626         if (cdev->private->state != DEV_STATE_OFFLINE)
1627                 goto out_unlock;
1628         ccw_device_online(cdev);
1629         while (!dev_fsm_final_state(cdev))
1630                 wait_cons_dev();
1631         if (cdev->private->state != DEV_STATE_ONLINE)
1632                 goto out_unlock;
1633         rc = 0;
1634 out_unlock:
1635         spin_unlock_irq(cdev->ccwlock);
1636         return 0;
1637 }
1638
1639 struct ccw_device *
1640 ccw_device_probe_console(void)
1641 {
1642         struct subchannel *sch;
1643         int ret;
1644
1645         if (xchg(&console_cdev_in_use, 1) != 0)
1646                 return ERR_PTR(-EBUSY);
1647         sch = cio_probe_console();
1648         if (IS_ERR(sch)) {
1649                 console_cdev_in_use = 0;
1650                 return (void *) sch;
1651         }
1652         memset(&console_cdev, 0, sizeof(struct ccw_device));
1653         memset(&console_private, 0, sizeof(struct ccw_device_private));
1654         console_cdev.private = &console_private;
1655         console_private.cdev = &console_cdev;
1656         ret = ccw_device_console_enable(&console_cdev, sch);
1657         if (ret) {
1658                 cio_release_console();
1659                 console_cdev_in_use = 0;
1660                 return ERR_PTR(ret);
1661         }
1662         console_cdev.online = 1;
1663         return &console_cdev;
1664 }
1665 #endif
1666
1667 /*
1668  * get ccw_device matching the busid, but only if owned by cdrv
1669  */
1670 static int
1671 __ccwdev_check_busid(struct device *dev, void *id)
1672 {
1673         char *bus_id;
1674
1675         bus_id = id;
1676
1677         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1678 }
1679
1680
1681 /**
1682  * get_ccwdev_by_busid() - obtain device from a bus id
1683  * @cdrv: driver the device is owned by
1684  * @bus_id: bus id of the device to be searched
1685  *
1686  * This function searches all devices owned by @cdrv for a device with a bus
1687  * id matching @bus_id.
1688  * Returns:
1689  *  If a match is found, its reference count of the found device is increased
1690  *  and it is returned; else %NULL is returned.
1691  */
1692 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1693                                        const char *bus_id)
1694 {
1695         struct device *dev;
1696         struct device_driver *drv;
1697
1698         drv = get_driver(&cdrv->driver);
1699         if (!drv)
1700                 return NULL;
1701
1702         dev = driver_find_device(drv, NULL, (void *)bus_id,
1703                                  __ccwdev_check_busid);
1704         put_driver(drv);
1705
1706         return dev ? to_ccwdev(dev) : NULL;
1707 }
1708
1709 /************************** device driver handling ************************/
1710
1711 /* This is the implementation of the ccw_driver class. The probe, remove
1712  * and release methods are initially very similar to the device_driver
1713  * implementations, with the difference that they have ccw_device
1714  * arguments.
1715  *
1716  * A ccw driver also contains the information that is needed for
1717  * device matching.
1718  */
1719 static int
1720 ccw_device_probe (struct device *dev)
1721 {
1722         struct ccw_device *cdev = to_ccwdev(dev);
1723         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1724         int ret;
1725
1726         cdev->drv = cdrv; /* to let the driver call _set_online */
1727
1728         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1729
1730         if (ret) {
1731                 cdev->drv = NULL;
1732                 return ret;
1733         }
1734
1735         return 0;
1736 }
1737
1738 static int
1739 ccw_device_remove (struct device *dev)
1740 {
1741         struct ccw_device *cdev = to_ccwdev(dev);
1742         struct ccw_driver *cdrv = cdev->drv;
1743         int ret;
1744
1745         if (cdrv->remove)
1746                 cdrv->remove(cdev);
1747         if (cdev->online) {
1748                 cdev->online = 0;
1749                 spin_lock_irq(cdev->ccwlock);
1750                 ret = ccw_device_offline(cdev);
1751                 spin_unlock_irq(cdev->ccwlock);
1752                 if (ret == 0)
1753                         wait_event(cdev->private->wait_q,
1754                                    dev_fsm_final_state(cdev));
1755                 else
1756                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1757                                       "device 0.%x.%04x\n",
1758                                       ret, cdev->private->dev_id.ssid,
1759                                       cdev->private->dev_id.devno);
1760         }
1761         ccw_device_set_timeout(cdev, 0);
1762         cdev->drv = NULL;
1763         return 0;
1764 }
1765
1766 static void ccw_device_shutdown(struct device *dev)
1767 {
1768         struct ccw_device *cdev;
1769
1770         cdev = to_ccwdev(dev);
1771         if (cdev->drv && cdev->drv->shutdown)
1772                 cdev->drv->shutdown(cdev);
1773         disable_cmf(cdev);
1774 }
1775
1776 struct bus_type ccw_bus_type = {
1777         .name   = "ccw",
1778         .match  = ccw_bus_match,
1779         .uevent = ccw_uevent,
1780         .probe  = ccw_device_probe,
1781         .remove = ccw_device_remove,
1782         .shutdown = ccw_device_shutdown,
1783 };
1784
1785 /**
1786  * ccw_driver_register() - register a ccw driver
1787  * @cdriver: driver to be registered
1788  *
1789  * This function is mainly a wrapper around driver_register().
1790  * Returns:
1791  *   %0 on success and a negative error value on failure.
1792  */
1793 int ccw_driver_register(struct ccw_driver *cdriver)
1794 {
1795         struct device_driver *drv = &cdriver->driver;
1796
1797         drv->bus = &ccw_bus_type;
1798         drv->name = cdriver->name;
1799         drv->owner = cdriver->owner;
1800
1801         return driver_register(drv);
1802 }
1803
1804 /**
1805  * ccw_driver_unregister() - deregister a ccw driver
1806  * @cdriver: driver to be deregistered
1807  *
1808  * This function is mainly a wrapper around driver_unregister().
1809  */
1810 void ccw_driver_unregister(struct ccw_driver *cdriver)
1811 {
1812         driver_unregister(&cdriver->driver);
1813 }
1814
1815 /* Helper func for qdio. */
1816 struct subchannel_id
1817 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1818 {
1819         struct subchannel *sch;
1820
1821         sch = to_subchannel(cdev->dev.parent);
1822         return sch->schid;
1823 }
1824
1825 MODULE_LICENSE("GPL");
1826 EXPORT_SYMBOL(ccw_device_set_online);
1827 EXPORT_SYMBOL(ccw_device_set_offline);
1828 EXPORT_SYMBOL(ccw_driver_register);
1829 EXPORT_SYMBOL(ccw_driver_unregister);
1830 EXPORT_SYMBOL(get_ccwdev_by_busid);
1831 EXPORT_SYMBOL(ccw_bus_type);
1832 EXPORT_SYMBOL(ccw_device_work);
1833 EXPORT_SYMBOL(ccw_device_notify_work);
1834 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);