drivers/s390/cio/device.c

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