drivers/s390/cio/device.c

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