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