drivers/s390/cio/device.c

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