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