SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/s390/cio/device.c

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