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
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/errno.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include <linux/list.h>
  21 #include <linux/device.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/timer.h>
  24
  25 #include <asm/ccwdev.h>
  26 #include <asm/cio.h>
  27 #include <asm/param.h>          /* HZ */
  28 #include <asm/cmb.h>
  29 #include <asm/isc.h>
  30
  31 #include "chp.h"
  32 #include "cio.h"
  33 #include "cio_debug.h"
  34 #include "css.h"
  35 #include "device.h"
  36 #include "ioasm.h"
  37 #include "io_sch.h"
  38 #include "blacklist.h"
  39 #include "chsc.h"
  40
  41 static struct timer_list recovery_timer;
  42 static DEFINE_SPINLOCK(recovery_lock);
  43 static int recovery_phase;
  44 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  45
  46 /******************* bus type handling ***********************/
  47
  48 /* The Linux driver model distinguishes between a bus type and
  49  * the bus itself. Of course we only have one channel
  50  * subsystem driver and one channel system per machine, but
  51  * we still use the abstraction. T.R. says it's a good idea. */
  52 static int
  53 ccw_bus_match (struct device * dev, struct device_driver * drv)
  54 {
  55         struct ccw_device *cdev = to_ccwdev(dev);
  56         struct ccw_driver *cdrv = to_ccwdrv(drv);
  57         const struct ccw_device_id *ids = cdrv->ids, *found;
  58
  59         if (!ids)
  60                 return 0;
  61
  62         found = ccw_device_id_match(ids, &cdev->id);
  63         if (!found)
  64                 return 0;
  65
  66         cdev->id.driver_info = found->driver_info;
  67
  68         return 1;
  69 }
  70
  71 /* Store modalias string delimited by prefix/suffix string into buffer with
  72  * specified size. Return length of resulting string (excluding trailing '\0')
  73  * even if string doesn't fit buffer (snprintf semantics). */
  74 static int snprint_alias(char *buf, size_t size,
  75                          struct ccw_device_id *id, const char *suffix)
  76 {
  77         int len;
  78
  79         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  80         if (len > size)
  81                 return len;
  82         buf += len;
  83         size -= len;
  84
  85         if (id->dev_type != 0)
  86                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  87                                 id->dev_model, suffix);
  88         else
  89                 len += snprintf(buf, size, "dtdm%s", suffix);
  90
  91         return len;
  92 }
  93
  94 /* Set up environment variables for ccw device uevent. Return 0 on success,
  95  * non-zero otherwise. */
  96 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  97 {
  98         struct ccw_device *cdev = to_ccwdev(dev);
  99         struct ccw_device_id *id = &(cdev->id);
 100         int ret;
 101         char modalias_buf[30];
 102
 103         /* CU_TYPE= */
 104         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 105         if (ret)
 106                 return ret;
 107
 108         /* CU_MODEL= */
 109         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 110         if (ret)
 111                 return ret;
 112
 113         /* The next two can be zero, that's ok for us */
 114         /* DEV_TYPE= */
 115         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 116         if (ret)
 117                 return ret;
 118
 119         /* DEV_MODEL= */
 120         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 121         if (ret)
 122                 return ret;
 123
 124         /* MODALIAS=  */
 125         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 126         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 127         return ret;
 128 }
 129
 130 static struct bus_type ccw_bus_type;
 131
 132 static void io_subchannel_irq(struct subchannel *);
 133 static int io_subchannel_probe(struct subchannel *);
 134 static int io_subchannel_remove(struct subchannel *);
 135 static void io_subchannel_shutdown(struct subchannel *);
 136 static int io_subchannel_sch_event(struct subchannel *, int);
 137 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 138                                    int);
 139 static void recovery_func(unsigned long data);
 140 wait_queue_head_t ccw_device_init_wq;
 141 atomic_t ccw_device_init_count;
 142
 143 static struct css_device_id io_subchannel_ids[] = {
 144         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 145         { /* end of list */ },
 146 };
 147 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 148
 149 static int io_subchannel_prepare(struct subchannel *sch)
 150 {
 151         struct ccw_device *cdev;
 152         /*
 153          * Don't allow suspend while a ccw device registration
 154          * is still outstanding.
 155          */
 156         cdev = sch_get_cdev(sch);
 157         if (cdev && !device_is_registered(&cdev->dev))
 158                 return -EAGAIN;
 159         return 0;
 160 }
 161
 162 static int io_subchannel_settle(void)
 163 {
 164         int ret;
 165
 166         ret = wait_event_interruptible(ccw_device_init_wq,
 167                                 atomic_read(&ccw_device_init_count) == 0);
 168         if (ret)
 169                 return -EINTR;
 170         flush_workqueue(cio_work_q);
 171         return 0;
 172 }
 173
 174 static struct css_driver io_subchannel_driver = {
 175         .drv = {
 176                 .owner = THIS_MODULE,
 177                 .name = "io_subchannel",
 178         },
 179         .subchannel_type = io_subchannel_ids,
 180         .irq = io_subchannel_irq,
 181         .sch_event = io_subchannel_sch_event,
 182         .chp_event = io_subchannel_chp_event,
 183         .probe = io_subchannel_probe,
 184         .remove = io_subchannel_remove,
 185         .shutdown = io_subchannel_shutdown,
 186         .prepare = io_subchannel_prepare,
 187         .settle = io_subchannel_settle,
 188 };
 189
 190 int __init io_subchannel_init(void)
 191 {
 192         int ret;
 193
 194         init_waitqueue_head(&ccw_device_init_wq);
 195         atomic_set(&ccw_device_init_count, 0);
 196         setup_timer(&recovery_timer, recovery_func, 0);
 197
 198         ret = bus_register(&ccw_bus_type);
 199         if (ret)
 200                 return ret;
 201         ret = css_driver_register(&io_subchannel_driver);
 202         if (ret)
 203                 bus_unregister(&ccw_bus_type);
 204
 205         return ret;
 206 }
 207
 208
 209 /************************ device handling **************************/
 210
 211 /*
 212  * A ccw_device has some interfaces in sysfs in addition to the
 213  * standard ones.
 214  * The following entries are designed to export the information which
 215  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 216  * are obvious, so they don't have an entry :)
 217  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 218  */
 219 static ssize_t
 220 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 221 {
 222         struct subchannel *sch = to_subchannel(dev);
 223         struct chsc_ssd_info *ssd = &sch->ssd_info;
 224         ssize_t ret = 0;
 225         int chp;
 226         int mask;
 227
 228         for (chp = 0; chp < 8; chp++) {
 229                 mask = 0x80 >> chp;
 230                 if (ssd->path_mask & mask)
 231                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 232                 else
 233                         ret += sprintf(buf + ret, "00 ");
 234         }
 235         ret += sprintf (buf+ret, "\n");
 236         return min((ssize_t)PAGE_SIZE, ret);
 237 }
 238
 239 static ssize_t
 240 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 241 {
 242         struct subchannel *sch = to_subchannel(dev);
 243         struct pmcw *pmcw = &sch->schib.pmcw;
 244
 245         return sprintf (buf, "%02x %02x %02x\n",
 246                         pmcw->pim, pmcw->pam, pmcw->pom);
 247 }
 248
 249 static ssize_t
 250 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 251 {
 252         struct ccw_device *cdev = to_ccwdev(dev);
 253         struct ccw_device_id *id = &(cdev->id);
 254
 255         if (id->dev_type != 0)
 256                 return sprintf(buf, "%04x/%02x\n",
 257                                 id->dev_type, id->dev_model);
 258         else
 259                 return sprintf(buf, "n/a\n");
 260 }
 261
 262 static ssize_t
 263 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 264 {
 265         struct ccw_device *cdev = to_ccwdev(dev);
 266         struct ccw_device_id *id = &(cdev->id);
 267
 268         return sprintf(buf, "%04x/%02x\n",
 269                        id->cu_type, id->cu_model);
 270 }
 271
 272 static ssize_t
 273 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 274 {
 275         struct ccw_device *cdev = to_ccwdev(dev);
 276         struct ccw_device_id *id = &(cdev->id);
 277         int len;
 278
 279         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 280
 281         return len > PAGE_SIZE ? PAGE_SIZE : len;
 282 }
 283
 284 static ssize_t
 285 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 286 {
 287         struct ccw_device *cdev = to_ccwdev(dev);
 288
 289         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 290 }
 291
 292 int ccw_device_is_orphan(struct ccw_device *cdev)
 293 {
 294         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 295 }
 296
 297 static void ccw_device_unregister(struct ccw_device *cdev)
 298 {
 299         if (device_is_registered(&cdev->dev)) {
 300                 /* Undo device_add(). */
 301                 device_del(&cdev->dev);
 302         }
 303         if (cdev->private->flags.initialized) {
 304                 cdev->private->flags.initialized = 0;
 305                 /* Release reference from device_initialize(). */
 306                 put_device(&cdev->dev);
 307         }
 308 }
 309
 310 static void io_subchannel_quiesce(struct subchannel *);
 311
 312 /**
 313  * ccw_device_set_offline() - disable a ccw device for I/O
 314  * @cdev: target ccw device
 315  *
 316  * This function calls the driver's set_offline() function for @cdev, if
 317  * given, and then disables @cdev.
 318  * Returns:
 319  *   %0 on success and a negative error value on failure.
 320  * Context:
 321  *  enabled, ccw device lock not held
 322  */
 323 int ccw_device_set_offline(struct ccw_device *cdev)
 324 {
 325         struct subchannel *sch;
 326         int ret, state;
 327
 328         if (!cdev)
 329                 return -ENODEV;
 330         if (!cdev->online || !cdev->drv)
 331                 return -EINVAL;
 332
 333         if (cdev->drv->set_offline) {
 334                 ret = cdev->drv->set_offline(cdev);
 335                 if (ret != 0)
 336                         return ret;
 337         }
 338         cdev->online = 0;
 339         spin_lock_irq(cdev->ccwlock);
 340         sch = to_subchannel(cdev->dev.parent);
 341         /* Wait until a final state or DISCONNECTED is reached */
 342         while (!dev_fsm_final_state(cdev) &&
 343                cdev->private->state != DEV_STATE_DISCONNECTED) {
 344                 spin_unlock_irq(cdev->ccwlock);
 345                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 346                            cdev->private->state == DEV_STATE_DISCONNECTED));
 347                 spin_lock_irq(cdev->ccwlock);
 348         }
 349         do {
 350                 ret = ccw_device_offline(cdev);
 351                 if (!ret)
 352                         break;
 353                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 354                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 355                               cdev->private->dev_id.devno);
 356                 if (ret != -EBUSY)
 357                         goto error;
 358                 state = cdev->private->state;
 359                 spin_unlock_irq(cdev->ccwlock);
 360                 io_subchannel_quiesce(sch);
 361                 spin_lock_irq(cdev->ccwlock);
 362                 cdev->private->state = state;
 363         } while (ret == -EBUSY);
 364         spin_unlock_irq(cdev->ccwlock);
 365         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 366                    cdev->private->state == DEV_STATE_DISCONNECTED));
 367         /* Inform the user if set offline failed. */
 368         if (cdev->private->state == DEV_STATE_BOXED) {
 369                 pr_warning("%s: The device entered boxed state while "
 370                            "being set offline\n", dev_name(&cdev->dev));
 371         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 372                 pr_warning("%s: The device stopped operating while "
 373                            "being set offline\n", dev_name(&cdev->dev));
 374         }
 375         /* Give up reference from ccw_device_set_online(). */
 376         put_device(&cdev->dev);
 377         return 0;
 378
 379 error:
 380         cdev->private->state = DEV_STATE_OFFLINE;
 381         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 382         spin_unlock_irq(cdev->ccwlock);
 383         /* Give up reference from ccw_device_set_online(). */
 384         put_device(&cdev->dev);
 385         return -ENODEV;
 386 }
 387
 388 /**
 389  * ccw_device_set_online() - enable a ccw device for I/O
 390  * @cdev: target ccw device
 391  *
 392  * This function first enables @cdev and then calls the driver's set_online()
 393  * function for @cdev, if given. If set_online() returns an error, @cdev is
 394  * disabled again.
 395  * Returns:
 396  *   %0 on success and a negative error value on failure.
 397  * Context:
 398  *  enabled, ccw device lock not held
 399  */
 400 int ccw_device_set_online(struct ccw_device *cdev)
 401 {
 402         int ret;
 403         int ret2;
 404
 405         if (!cdev)
 406                 return -ENODEV;
 407         if (cdev->online || !cdev->drv)
 408                 return -EINVAL;
 409         /* Hold on to an extra reference while device is online. */
 410         if (!get_device(&cdev->dev))
 411                 return -ENODEV;
 412
 413         spin_lock_irq(cdev->ccwlock);
 414         ret = ccw_device_online(cdev);
 415         spin_unlock_irq(cdev->ccwlock);
 416         if (ret == 0)
 417                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 418         else {
 419                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 420                               "device 0.%x.%04x\n",
 421                               ret, cdev->private->dev_id.ssid,
 422                               cdev->private->dev_id.devno);
 423                 /* Give up online reference since onlining failed. */
 424                 put_device(&cdev->dev);
 425                 return ret;
 426         }
 427         spin_lock_irq(cdev->ccwlock);
 428         /* Check if online processing was successful */
 429         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 430             (cdev->private->state != DEV_STATE_W4SENSE)) {
 431                 spin_unlock_irq(cdev->ccwlock);
 432                 /* Inform the user that set online failed. */
 433                 if (cdev->private->state == DEV_STATE_BOXED) {
 434                         pr_warning("%s: Setting the device online failed "
 435                                    "because it is boxed\n",
 436                                    dev_name(&cdev->dev));
 437                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 438                         pr_warning("%s: Setting the device online failed "
 439                                    "because it is not operational\n",
 440                                    dev_name(&cdev->dev));
 441                 }
 442                 /* Give up online reference since onlining failed. */
 443                 put_device(&cdev->dev);
 444                 return -ENODEV;
 445         }
 446         spin_unlock_irq(cdev->ccwlock);
 447         if (cdev->drv->set_online)
 448                 ret = cdev->drv->set_online(cdev);
 449         if (ret)
 450                 goto rollback;
 451         cdev->online = 1;
 452         return 0;
 453
 454 rollback:
 455         spin_lock_irq(cdev->ccwlock);
 456         /* Wait until a final state or DISCONNECTED is reached */
 457         while (!dev_fsm_final_state(cdev) &&
 458                cdev->private->state != DEV_STATE_DISCONNECTED) {
 459                 spin_unlock_irq(cdev->ccwlock);
 460                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 461                            cdev->private->state == DEV_STATE_DISCONNECTED));
 462                 spin_lock_irq(cdev->ccwlock);
 463         }
 464         ret2 = ccw_device_offline(cdev);
 465         if (ret2)
 466                 goto error;
 467         spin_unlock_irq(cdev->ccwlock);
 468         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 469                    cdev->private->state == DEV_STATE_DISCONNECTED));
 470         /* Give up online reference since onlining failed. */
 471         put_device(&cdev->dev);
 472         return ret;
 473
 474 error:
 475         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 476                       "device 0.%x.%04x\n",
 477                       ret2, cdev->private->dev_id.ssid,
 478                       cdev->private->dev_id.devno);
 479         cdev->private->state = DEV_STATE_OFFLINE;
 480         spin_unlock_irq(cdev->ccwlock);
 481         /* Give up online reference since onlining failed. */
 482         put_device(&cdev->dev);
 483         return ret;
 484 }
 485
 486 static int online_store_handle_offline(struct ccw_device *cdev)
 487 {
 488         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 489                 spin_lock_irq(cdev->ccwlock);
 490                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 491                 spin_unlock_irq(cdev->ccwlock);
 492                 return 0;
 493         }
 494         if (cdev->drv && cdev->drv->set_offline)
 495                 return ccw_device_set_offline(cdev);
 496         return -EINVAL;
 497 }
 498
 499 static int online_store_recog_and_online(struct ccw_device *cdev)
 500 {
 501         /* Do device recognition, if needed. */
 502         if (cdev->private->state == DEV_STATE_BOXED) {
 503                 spin_lock_irq(cdev->ccwlock);
 504                 ccw_device_recognition(cdev);
 505                 spin_unlock_irq(cdev->ccwlock);
 506                 wait_event(cdev->private->wait_q,
 507                            cdev->private->flags.recog_done);
 508                 if (cdev->private->state != DEV_STATE_OFFLINE)
 509                         /* recognition failed */
 510                         return -EAGAIN;
 511         }
 512         if (cdev->drv && cdev->drv->set_online)
 513                 return ccw_device_set_online(cdev);
 514         return -EINVAL;
 515 }
 516
 517 static int online_store_handle_online(struct ccw_device *cdev, int force)
 518 {
 519         int ret;
 520
 521         ret = online_store_recog_and_online(cdev);
 522         if (ret && !force)
 523                 return ret;
 524         if (force && cdev->private->state == DEV_STATE_BOXED) {
 525                 ret = ccw_device_stlck(cdev);
 526                 if (ret)
 527                         return ret;
 528                 if (cdev->id.cu_type == 0)
 529                         cdev->private->state = DEV_STATE_NOT_OPER;
 530                 ret = online_store_recog_and_online(cdev);
 531                 if (ret)
 532                         return ret;
 533         }
 534         return 0;
 535 }
 536
 537 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 538                              const char *buf, size_t count)
 539 {
 540         struct ccw_device *cdev = to_ccwdev(dev);
 541         int force, ret;
 542         unsigned long i;
 543
 544         if (!dev_fsm_final_state(cdev) &&
 545             cdev->private->state != DEV_STATE_DISCONNECTED)
 546                 return -EAGAIN;
 547         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 548                 return -EAGAIN;
 549
 550         if (cdev->drv && !try_module_get(cdev->drv->driver.owner)) {
 551                 atomic_set(&cdev->private->onoff, 0);
 552                 return -EINVAL;
 553         }
 554         if (!strncmp(buf, "force\n", count)) {
 555                 force = 1;
 556                 i = 1;
 557                 ret = 0;
 558         } else {
 559                 force = 0;
 560                 ret = strict_strtoul(buf, 16, &i);
 561         }
 562         if (ret)
 563                 goto out;
 564         switch (i) {
 565         case 0:
 566                 ret = online_store_handle_offline(cdev);
 567                 break;
 568         case 1:
 569                 ret = online_store_handle_online(cdev, force);
 570                 break;
 571         default:
 572                 ret = -EINVAL;
 573         }
 574 out:
 575         if (cdev->drv)
 576                 module_put(cdev->drv->driver.owner);
 577         atomic_set(&cdev->private->onoff, 0);
 578         return (ret < 0) ? ret : count;
 579 }
 580
 581 static ssize_t
 582 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 583 {
 584         struct ccw_device *cdev = to_ccwdev(dev);
 585         struct subchannel *sch;
 586
 587         if (ccw_device_is_orphan(cdev))
 588                 return sprintf(buf, "no device\n");
 589         switch (cdev->private->state) {
 590         case DEV_STATE_BOXED:
 591                 return sprintf(buf, "boxed\n");
 592         case DEV_STATE_DISCONNECTED:
 593         case DEV_STATE_DISCONNECTED_SENSE_ID:
 594         case DEV_STATE_NOT_OPER:
 595                 sch = to_subchannel(dev->parent);
 596                 if (!sch->lpm)
 597                         return sprintf(buf, "no path\n");
 598                 else
 599                         return sprintf(buf, "no device\n");
 600         default:
 601                 /* All other states considered fine. */
 602                 return sprintf(buf, "good\n");
 603         }
 604 }
 605
 606 static ssize_t
 607 initiate_logging(struct device *dev, struct device_attribute *attr,
 608                  const char *buf, size_t count)
 609 {
 610         struct subchannel *sch = to_subchannel(dev);
 611         int rc;
 612
 613         rc = chsc_siosl(sch->schid);
 614         if (rc < 0) {
 615                 pr_warning("Logging for subchannel 0.%x.%04x failed with "
 616                            "errno=%d\n",
 617                            sch->schid.ssid, sch->schid.sch_no, rc);
 618                 return rc;
 619         }
 620         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 621                   sch->schid.ssid, sch->schid.sch_no);
 622         return count;
 623 }
 624
 625 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 626 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 627 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 628 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 629 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 630 static DEVICE_ATTR(online, 0644, online_show, online_store);
 631 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 632 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 633
 634 static struct attribute *io_subchannel_attrs[] = {
 635         &dev_attr_chpids.attr,
 636         &dev_attr_pimpampom.attr,
 637         &dev_attr_logging.attr,
 638         NULL,
 639 };
 640
 641 static struct attribute_group io_subchannel_attr_group = {
 642         .attrs = io_subchannel_attrs,
 643 };
 644
 645 static struct attribute * ccwdev_attrs[] = {
 646         &dev_attr_devtype.attr,
 647         &dev_attr_cutype.attr,
 648         &dev_attr_modalias.attr,
 649         &dev_attr_online.attr,
 650         &dev_attr_cmb_enable.attr,
 651         &dev_attr_availability.attr,
 652         NULL,
 653 };
 654
 655 static struct attribute_group ccwdev_attr_group = {
 656         .attrs = ccwdev_attrs,
 657 };
 658
 659 static const struct attribute_group *ccwdev_attr_groups[] = {
 660         &ccwdev_attr_group,
 661         NULL,
 662 };
 663
 664 /* this is a simple abstraction for device_register that sets the
 665  * correct bus type and adds the bus specific files */
 666 static int ccw_device_register(struct ccw_device *cdev)
 667 {
 668         struct device *dev = &cdev->dev;
 669         int ret;
 670
 671         dev->bus = &ccw_bus_type;
 672         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 673                            cdev->private->dev_id.devno);
 674         if (ret)
 675                 return ret;
 676         return device_add(dev);
 677 }
 678
 679 static int match_dev_id(struct device *dev, void *data)
 680 {
 681         struct ccw_device *cdev = to_ccwdev(dev);
 682         struct ccw_dev_id *dev_id = data;
 683
 684         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 685 }
 686
 687 static struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 688 {
 689         struct device *dev;
 690
 691         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 692
 693         return dev ? to_ccwdev(dev) : NULL;
 694 }
 695
 696 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 697 {
 698         int ret;
 699
 700         if (device_is_registered(&cdev->dev)) {
 701                 device_release_driver(&cdev->dev);
 702                 ret = device_attach(&cdev->dev);
 703                 WARN_ON(ret == -ENODEV);
 704         }
 705 }
 706
 707 static void
 708 ccw_device_release(struct device *dev)
 709 {
 710         struct ccw_device *cdev;
 711
 712         cdev = to_ccwdev(dev);
 713         /* Release reference of parent subchannel. */
 714         put_device(cdev->dev.parent);
 715         kfree(cdev->private);
 716         kfree(cdev);
 717 }
 718
 719 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 720 {
 721         struct ccw_device *cdev;
 722
 723         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 724         if (cdev) {
 725                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 726                                         GFP_KERNEL | GFP_DMA);
 727                 if (cdev->private)
 728                         return cdev;
 729         }
 730         kfree(cdev);
 731         return ERR_PTR(-ENOMEM);
 732 }
 733
 734 static void ccw_device_todo(struct work_struct *work);
 735
 736 static int io_subchannel_initialize_dev(struct subchannel *sch,
 737                                         struct ccw_device *cdev)
 738 {
 739         cdev->private->cdev = cdev;
 740         atomic_set(&cdev->private->onoff, 0);
 741         cdev->dev.parent = &sch->dev;
 742         cdev->dev.release = ccw_device_release;
 743         INIT_WORK(&cdev->private->todo_work, ccw_device_todo);
 744         cdev->dev.groups = ccwdev_attr_groups;
 745         /* Do first half of device_register. */
 746         device_initialize(&cdev->dev);
 747         if (!get_device(&sch->dev)) {
 748                 /* Release reference from device_initialize(). */
 749                 put_device(&cdev->dev);
 750                 return -ENODEV;
 751         }
 752         cdev->private->flags.initialized = 1;
 753         return 0;
 754 }
 755
 756 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 757 {
 758         struct ccw_device *cdev;
 759         int ret;
 760
 761         cdev = io_subchannel_allocate_dev(sch);
 762         if (!IS_ERR(cdev)) {
 763                 ret = io_subchannel_initialize_dev(sch, cdev);
 764                 if (ret)
 765                         cdev = ERR_PTR(ret);
 766         }
 767         return cdev;
 768 }
 769
 770 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 771
 772 static void sch_create_and_recog_new_device(struct subchannel *sch)
 773 {
 774         struct ccw_device *cdev;
 775
 776         /* Need to allocate a new ccw device. */
 777         cdev = io_subchannel_create_ccwdev(sch);
 778         if (IS_ERR(cdev)) {
 779                 /* OK, we did everything we could... */
 780                 css_sch_device_unregister(sch);
 781                 return;
 782         }
 783         /* Start recognition for the new ccw device. */
 784         io_subchannel_recog(cdev, sch);
 785 }
 786
 787 /*
 788  * Register recognized device.
 789  */
 790 static void io_subchannel_register(struct ccw_device *cdev)
 791 {
 792         struct subchannel *sch;
 793         int ret, adjust_init_count = 1;
 794         unsigned long flags;
 795
 796         sch = to_subchannel(cdev->dev.parent);
 797         /*
 798          * Check if subchannel is still registered. It may have become
 799          * unregistered if a machine check hit us after finishing
 800          * device recognition but before the register work could be
 801          * queued.
 802          */
 803         if (!device_is_registered(&sch->dev))
 804                 goto out_err;
 805         css_update_ssd_info(sch);
 806         /*
 807          * io_subchannel_register() will also be called after device
 808          * recognition has been done for a boxed device (which will already
 809          * be registered). We need to reprobe since we may now have sense id
 810          * information.
 811          */
 812         if (device_is_registered(&cdev->dev)) {
 813                 if (!cdev->drv) {
 814                         ret = device_reprobe(&cdev->dev);
 815                         if (ret)
 816                                 /* We can't do much here. */
 817                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 818                                               " %d for 0.%x.%04x\n", ret,
 819                                               cdev->private->dev_id.ssid,
 820                                               cdev->private->dev_id.devno);
 821                 }
 822                 adjust_init_count = 0;
 823                 goto out;
 824         }
 825         /*
 826          * Now we know this subchannel will stay, we can throw
 827          * our delayed uevent.
 828          */
 829         dev_set_uevent_suppress(&sch->dev, 0);
 830         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 831         /* make it known to the system */
 832         ret = ccw_device_register(cdev);
 833         if (ret) {
 834                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 835                               cdev->private->dev_id.ssid,
 836                               cdev->private->dev_id.devno, ret);
 837                 spin_lock_irqsave(sch->lock, flags);
 838                 sch_set_cdev(sch, NULL);
 839                 spin_unlock_irqrestore(sch->lock, flags);
 840                 /* Release initial device reference. */
 841                 put_device(&cdev->dev);
 842                 goto out_err;
 843         }
 844 out:
 845         cdev->private->flags.recog_done = 1;
 846         wake_up(&cdev->private->wait_q);
 847 out_err:
 848         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 849                 wake_up(&ccw_device_init_wq);
 850 }
 851
 852 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 853 {
 854         struct subchannel *sch;
 855
 856         /* Get subchannel reference for local processing. */
 857         if (!get_device(cdev->dev.parent))
 858                 return;
 859         sch = to_subchannel(cdev->dev.parent);
 860         css_sch_device_unregister(sch);
 861         /* Release subchannel reference for local processing. */
 862         put_device(&sch->dev);
 863 }
 864
 865 /*
 866  * subchannel recognition done. Called from the state machine.
 867  */
 868 void
 869 io_subchannel_recog_done(struct ccw_device *cdev)
 870 {
 871         if (css_init_done == 0) {
 872                 cdev->private->flags.recog_done = 1;
 873                 return;
 874         }
 875         switch (cdev->private->state) {
 876         case DEV_STATE_BOXED:
 877                 /* Device did not respond in time. */
 878         case DEV_STATE_NOT_OPER:
 879                 cdev->private->flags.recog_done = 1;
 880                 /* Remove device found not operational. */
 881                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 882                 if (atomic_dec_and_test(&ccw_device_init_count))
 883                         wake_up(&ccw_device_init_wq);
 884                 break;
 885         case DEV_STATE_OFFLINE:
 886                 /*
 887                  * We can't register the device in interrupt context so
 888                  * we schedule a work item.
 889                  */
 890                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 891                 break;
 892         }
 893 }
 894
 895 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 896 {
 897         struct ccw_device_private *priv;
 898
 899         cdev->ccwlock = sch->lock;
 900
 901         /* Init private data. */
 902         priv = cdev->private;
 903         priv->dev_id.devno = sch->schib.pmcw.dev;
 904         priv->dev_id.ssid = sch->schid.ssid;
 905         priv->schid = sch->schid;
 906         priv->state = DEV_STATE_NOT_OPER;
 907         INIT_LIST_HEAD(&priv->cmb_list);
 908         init_waitqueue_head(&priv->wait_q);
 909         init_timer(&priv->timer);
 910
 911         /* Increase counter of devices currently in recognition. */
 912         atomic_inc(&ccw_device_init_count);
 913
 914         /* Start async. device sensing. */
 915         spin_lock_irq(sch->lock);
 916         sch_set_cdev(sch, cdev);
 917         ccw_device_recognition(cdev);
 918         spin_unlock_irq(sch->lock);
 919 }
 920
 921 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 922                                   struct subchannel *sch)
 923 {
 924         struct subchannel *old_sch;
 925         int rc, old_enabled = 0;
 926
 927         old_sch = to_subchannel(cdev->dev.parent);
 928         /* Obtain child reference for new parent. */
 929         if (!get_device(&sch->dev))
 930                 return -ENODEV;
 931
 932         if (!sch_is_pseudo_sch(old_sch)) {
 933                 spin_lock_irq(old_sch->lock);
 934                 old_enabled = old_sch->schib.pmcw.ena;
 935                 rc = 0;
 936                 if (old_enabled)
 937                         rc = cio_disable_subchannel(old_sch);
 938                 spin_unlock_irq(old_sch->lock);
 939                 if (rc == -EBUSY) {
 940                         /* Release child reference for new parent. */
 941                         put_device(&sch->dev);
 942                         return rc;
 943                 }
 944         }
 945
 946         mutex_lock(&sch->reg_mutex);
 947         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 948         mutex_unlock(&sch->reg_mutex);
 949         if (rc) {
 950                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 951                               cdev->private->dev_id.ssid,
 952                               cdev->private->dev_id.devno, sch->schid.ssid,
 953                               sch->schib.pmcw.dev, rc);
 954                 if (old_enabled) {
 955                         /* Try to reenable the old subchannel. */
 956                         spin_lock_irq(old_sch->lock);
 957                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 958                         spin_unlock_irq(old_sch->lock);
 959                 }
 960                 /* Release child reference for new parent. */
 961                 put_device(&sch->dev);
 962                 return rc;
 963         }
 964         /* Clean up old subchannel. */
 965         if (!sch_is_pseudo_sch(old_sch)) {
 966                 spin_lock_irq(old_sch->lock);
 967                 sch_set_cdev(old_sch, NULL);
 968                 spin_unlock_irq(old_sch->lock);
 969                 css_schedule_eval(old_sch->schid);
 970         }
 971         /* Release child reference for old parent. */
 972         put_device(&old_sch->dev);
 973         /* Initialize new subchannel. */
 974         spin_lock_irq(sch->lock);
 975         cdev->private->schid = sch->schid;
 976         cdev->ccwlock = sch->lock;
 977         if (!sch_is_pseudo_sch(sch))
 978                 sch_set_cdev(sch, cdev);
 979         spin_unlock_irq(sch->lock);
 980         if (!sch_is_pseudo_sch(sch))
 981                 css_update_ssd_info(sch);
 982         return 0;
 983 }
 984
 985 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 986 {
 987         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 988         struct channel_subsystem *css = to_css(sch->dev.parent);
 989
 990         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 991 }
 992
 993 static void io_subchannel_irq(struct subchannel *sch)
 994 {
 995         struct ccw_device *cdev;
 996
 997         cdev = sch_get_cdev(sch);
 998
 999         CIO_TRACE_EVENT(6, "IRQ");
1000         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1001         if (cdev)
1002                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1003 }
1004
1005 void io_subchannel_init_config(struct subchannel *sch)
1006 {
1007         memset(&sch->config, 0, sizeof(sch->config));
1008         sch->config.csense = 1;
1009 }
1010
1011 static void io_subchannel_init_fields(struct subchannel *sch)
1012 {
1013         if (cio_is_console(sch->schid))
1014                 sch->opm = 0xff;
1015         else
1016                 sch->opm = chp_get_sch_opm(sch);
1017         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1018         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1019
1020         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1021                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1022                       sch->schib.pmcw.dev, sch->schid.ssid,
1023                       sch->schid.sch_no, sch->schib.pmcw.pim,
1024                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1025
1026         io_subchannel_init_config(sch);
1027 }
1028
1029 /*
1030  * Note: We always return 0 so that we bind to the device even on error.
1031  * This is needed so that our remove function is called on unregister.
1032  */
1033 static int io_subchannel_probe(struct subchannel *sch)
1034 {
1035         struct io_subchannel_private *io_priv;
1036         struct ccw_device *cdev;
1037         int rc;
1038
1039         if (cio_is_console(sch->schid)) {
1040                 rc = sysfs_create_group(&sch->dev.kobj,
1041                                         &io_subchannel_attr_group);
1042                 if (rc)
1043                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1044                                       "attributes for subchannel "
1045                                       "0.%x.%04x (rc=%d)\n",
1046                                       sch->schid.ssid, sch->schid.sch_no, rc);
1047                 /*
1048                  * The console subchannel already has an associated ccw_device.
1049                  * Throw the delayed uevent for the subchannel, register
1050                  * the ccw_device and exit.
1051                  */
1052                 dev_set_uevent_suppress(&sch->dev, 0);
1053                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1054                 cdev = sch_get_cdev(sch);
1055                 cdev->dev.groups = ccwdev_attr_groups;
1056                 device_initialize(&cdev->dev);
1057                 cdev->private->flags.initialized = 1;
1058                 ccw_device_register(cdev);
1059                 /*
1060                  * Check if the device is already online. If it is
1061                  * the reference count needs to be corrected since we
1062                  * didn't obtain a reference in ccw_device_set_online.
1063                  */
1064                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1065                     cdev->private->state != DEV_STATE_OFFLINE &&
1066                     cdev->private->state != DEV_STATE_BOXED)
1067                         get_device(&cdev->dev);
1068                 return 0;
1069         }
1070         io_subchannel_init_fields(sch);
1071         rc = cio_commit_config(sch);
1072         if (rc)
1073                 goto out_schedule;
1074         rc = sysfs_create_group(&sch->dev.kobj,
1075                                 &io_subchannel_attr_group);
1076         if (rc)
1077                 goto out_schedule;
1078         /* Allocate I/O subchannel private data. */
1079         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1080         if (!io_priv)
1081                 goto out_schedule;
1082
1083         set_io_private(sch, io_priv);
1084         css_schedule_eval(sch->schid);
1085         return 0;
1086
1087 out_schedule:
1088         spin_lock_irq(sch->lock);
1089         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1090         spin_unlock_irq(sch->lock);
1091         return 0;
1092 }
1093
1094 static int
1095 io_subchannel_remove (struct subchannel *sch)
1096 {
1097         struct io_subchannel_private *io_priv = to_io_private(sch);
1098         struct ccw_device *cdev;
1099
1100         cdev = sch_get_cdev(sch);
1101         if (!cdev)
1102                 goto out_free;
1103         io_subchannel_quiesce(sch);
1104         /* Set ccw device to not operational and drop reference. */
1105         spin_lock_irq(cdev->ccwlock);
1106         sch_set_cdev(sch, NULL);
1107         set_io_private(sch, NULL);
1108         cdev->private->state = DEV_STATE_NOT_OPER;
1109         spin_unlock_irq(cdev->ccwlock);
1110         ccw_device_unregister(cdev);
1111 out_free:
1112         kfree(io_priv);
1113         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1114         return 0;
1115 }
1116
1117 static void io_subchannel_verify(struct subchannel *sch)
1118 {
1119         struct ccw_device *cdev;
1120
1121         cdev = sch_get_cdev(sch);
1122         if (cdev)
1123                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1124 }
1125
1126 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1127 {
1128         struct ccw_device *cdev;
1129
1130         cdev = sch_get_cdev(sch);
1131         if (!cdev)
1132                 return;
1133         if (cio_update_schib(sch))
1134                 goto err;
1135         /* Check for I/O on path. */
1136         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1137                 goto out;
1138         if (cdev->private->state == DEV_STATE_ONLINE) {
1139                 ccw_device_kill_io(cdev);
1140                 goto out;
1141         }
1142         if (cio_clear(sch))
1143                 goto err;
1144 out:
1145         /* Trigger path verification. */
1146         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1147         return;
1148
1149 err:
1150         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1151 }
1152
1153 static int io_subchannel_chp_event(struct subchannel *sch,
1154                                    struct chp_link *link, int event)
1155 {
1156         struct ccw_device *cdev = sch_get_cdev(sch);
1157         int mask;
1158
1159         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1160         if (!mask)
1161                 return 0;
1162         switch (event) {
1163         case CHP_VARY_OFF:
1164                 sch->opm &= ~mask;
1165                 sch->lpm &= ~mask;
1166                 if (cdev)
1167                         cdev->private->path_gone_mask |= mask;
1168                 io_subchannel_terminate_path(sch, mask);
1169                 break;
1170         case CHP_VARY_ON:
1171                 sch->opm |= mask;
1172                 sch->lpm |= mask;
1173                 if (cdev)
1174                         cdev->private->path_new_mask |= mask;
1175                 io_subchannel_verify(sch);
1176                 break;
1177         case CHP_OFFLINE:
1178                 if (cio_update_schib(sch))
1179                         return -ENODEV;
1180                 if (cdev)
1181                         cdev->private->path_gone_mask |= mask;
1182                 io_subchannel_terminate_path(sch, mask);
1183                 break;
1184         case CHP_ONLINE:
1185                 if (cio_update_schib(sch))
1186                         return -ENODEV;
1187                 sch->lpm |= mask & sch->opm;
1188                 if (cdev)
1189                         cdev->private->path_new_mask |= mask;
1190                 io_subchannel_verify(sch);
1191                 break;
1192         }
1193         return 0;
1194 }
1195
1196 static void io_subchannel_quiesce(struct subchannel *sch)
1197 {
1198         struct ccw_device *cdev;
1199         int ret;
1200
1201         spin_lock_irq(sch->lock);
1202         cdev = sch_get_cdev(sch);
1203         if (cio_is_console(sch->schid))
1204                 goto out_unlock;
1205         if (!sch->schib.pmcw.ena)
1206                 goto out_unlock;
1207         ret = cio_disable_subchannel(sch);
1208         if (ret != -EBUSY)
1209                 goto out_unlock;
1210         if (cdev->handler)
1211                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1212         while (ret == -EBUSY) {
1213                 cdev->private->state = DEV_STATE_QUIESCE;
1214                 cdev->private->iretry = 255;
1215                 ret = ccw_device_cancel_halt_clear(cdev);
1216                 if (ret == -EBUSY) {
1217                         ccw_device_set_timeout(cdev, HZ/10);
1218                         spin_unlock_irq(sch->lock);
1219                         wait_event(cdev->private->wait_q,
1220                                    cdev->private->state != DEV_STATE_QUIESCE);
1221                         spin_lock_irq(sch->lock);
1222                 }
1223                 ret = cio_disable_subchannel(sch);
1224         }
1225 out_unlock:
1226         spin_unlock_irq(sch->lock);
1227 }
1228
1229 static void io_subchannel_shutdown(struct subchannel *sch)
1230 {
1231         io_subchannel_quiesce(sch);
1232 }
1233
1234 static int device_is_disconnected(struct ccw_device *cdev)
1235 {
1236         if (!cdev)
1237                 return 0;
1238         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1239                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1240 }
1241
1242 static int recovery_check(struct device *dev, void *data)
1243 {
1244         struct ccw_device *cdev = to_ccwdev(dev);
1245         int *redo = data;
1246
1247         spin_lock_irq(cdev->ccwlock);
1248         switch (cdev->private->state) {
1249         case DEV_STATE_DISCONNECTED:
1250                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1251                               cdev->private->dev_id.ssid,
1252                               cdev->private->dev_id.devno);
1253                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1254                 *redo = 1;
1255                 break;
1256         case DEV_STATE_DISCONNECTED_SENSE_ID:
1257                 *redo = 1;
1258                 break;
1259         }
1260         spin_unlock_irq(cdev->ccwlock);
1261
1262         return 0;
1263 }
1264
1265 static void recovery_work_func(struct work_struct *unused)
1266 {
1267         int redo = 0;
1268
1269         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1270         if (redo) {
1271                 spin_lock_irq(&recovery_lock);
1272                 if (!timer_pending(&recovery_timer)) {
1273                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1274                                 recovery_phase++;
1275                         mod_timer(&recovery_timer, jiffies +
1276                                   recovery_delay[recovery_phase] * HZ);
1277                 }
1278                 spin_unlock_irq(&recovery_lock);
1279         } else
1280                 CIO_MSG_EVENT(4, "recovery: end\n");
1281 }
1282
1283 static DECLARE_WORK(recovery_work, recovery_work_func);
1284
1285 static void recovery_func(unsigned long data)
1286 {
1287         /*
1288          * We can't do our recovery in softirq context and it's not
1289          * performance critical, so we schedule it.
1290          */
1291         schedule_work(&recovery_work);
1292 }
1293
1294 static void ccw_device_schedule_recovery(void)
1295 {
1296         unsigned long flags;
1297
1298         CIO_MSG_EVENT(4, "recovery: schedule\n");
1299         spin_lock_irqsave(&recovery_lock, flags);
1300         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1301                 recovery_phase = 0;
1302                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1303         }
1304         spin_unlock_irqrestore(&recovery_lock, flags);
1305 }
1306
1307 static int purge_fn(struct device *dev, void *data)
1308 {
1309         struct ccw_device *cdev = to_ccwdev(dev);
1310         struct ccw_dev_id *id = &cdev->private->dev_id;
1311
1312         spin_lock_irq(cdev->ccwlock);
1313         if (is_blacklisted(id->ssid, id->devno) &&
1314             (cdev->private->state == DEV_STATE_OFFLINE)) {
1315                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1316                               id->devno);
1317                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1318         }
1319         spin_unlock_irq(cdev->ccwlock);
1320         /* Abort loop in case of pending signal. */
1321         if (signal_pending(current))
1322                 return -EINTR;
1323
1324         return 0;
1325 }
1326
1327 /**
1328  * ccw_purge_blacklisted - purge unused, blacklisted devices
1329  *
1330  * Unregister all ccw devices that are offline and on the blacklist.
1331  */
1332 int ccw_purge_blacklisted(void)
1333 {
1334         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1335         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1336         return 0;
1337 }
1338
1339 void ccw_device_set_disconnected(struct ccw_device *cdev)
1340 {
1341         if (!cdev)
1342                 return;
1343         ccw_device_set_timeout(cdev, 0);
1344         cdev->private->flags.fake_irb = 0;
1345         cdev->private->state = DEV_STATE_DISCONNECTED;
1346         if (cdev->online)
1347                 ccw_device_schedule_recovery();
1348 }
1349
1350 void ccw_device_set_notoper(struct ccw_device *cdev)
1351 {
1352         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1353
1354         CIO_TRACE_EVENT(2, "notoper");
1355         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1356         ccw_device_set_timeout(cdev, 0);
1357         cio_disable_subchannel(sch);
1358         cdev->private->state = DEV_STATE_NOT_OPER;
1359 }
1360
1361 enum io_sch_action {
1362         IO_SCH_UNREG,
1363         IO_SCH_ORPH_UNREG,
1364         IO_SCH_ATTACH,
1365         IO_SCH_UNREG_ATTACH,
1366         IO_SCH_ORPH_ATTACH,
1367         IO_SCH_REPROBE,
1368         IO_SCH_VERIFY,
1369         IO_SCH_DISC,
1370         IO_SCH_NOP,
1371 };
1372
1373 static enum io_sch_action sch_get_action(struct subchannel *sch)
1374 {
1375         struct ccw_device *cdev;
1376
1377         cdev = sch_get_cdev(sch);
1378         if (cio_update_schib(sch)) {
1379                 /* Not operational. */
1380                 if (!cdev)
1381                         return IO_SCH_UNREG;
1382                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1383                         return IO_SCH_UNREG;
1384                 return IO_SCH_ORPH_UNREG;
1385         }
1386         /* Operational. */
1387         if (!cdev)
1388                 return IO_SCH_ATTACH;
1389         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1390                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1391                         return IO_SCH_UNREG_ATTACH;
1392                 return IO_SCH_ORPH_ATTACH;
1393         }
1394         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1395                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1396                         return IO_SCH_UNREG;
1397                 return IO_SCH_DISC;
1398         }
1399         if (device_is_disconnected(cdev))
1400                 return IO_SCH_REPROBE;
1401         if (cdev->online)
1402                 return IO_SCH_VERIFY;
1403         return IO_SCH_NOP;
1404 }
1405
1406 /**
1407  * io_subchannel_sch_event - process subchannel event
1408  * @sch: subchannel
1409  * @process: non-zero if function is called in process context
1410  *
1411  * An unspecified event occurred for this subchannel. Adjust data according
1412  * to the current operational state of the subchannel and device. Return
1413  * zero when the event has been handled sufficiently or -EAGAIN when this
1414  * function should be called again in process context.
1415  */
1416 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1417 {
1418         unsigned long flags;
1419         struct ccw_device *cdev;
1420         struct ccw_dev_id dev_id;
1421         enum io_sch_action action;
1422         int rc = -EAGAIN;
1423
1424         spin_lock_irqsave(sch->lock, flags);
1425         if (!device_is_registered(&sch->dev))
1426                 goto out_unlock;
1427         if (work_pending(&sch->todo_work))
1428                 goto out_unlock;
1429         cdev = sch_get_cdev(sch);
1430         if (cdev && work_pending(&cdev->private->todo_work))
1431                 goto out_unlock;
1432         action = sch_get_action(sch);
1433         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1434                       sch->schid.ssid, sch->schid.sch_no, process,
1435                       action);
1436         /* Perform immediate actions while holding the lock. */
1437         switch (action) {
1438         case IO_SCH_REPROBE:
1439                 /* Trigger device recognition. */
1440                 ccw_device_trigger_reprobe(cdev);
1441                 rc = 0;
1442                 goto out_unlock;
1443         case IO_SCH_VERIFY:
1444                 if (cdev->private->flags.resuming == 1) {
1445                         if (cio_enable_subchannel(sch, (u32)(addr_t)sch)) {
1446                                 ccw_device_set_notoper(cdev);
1447                                 break;
1448                         }
1449                 }
1450                 /* Trigger path verification. */
1451                 io_subchannel_verify(sch);
1452                 rc = 0;
1453                 goto out_unlock;
1454         case IO_SCH_DISC:
1455                 ccw_device_set_disconnected(cdev);
1456                 rc = 0;
1457                 goto out_unlock;
1458         case IO_SCH_ORPH_UNREG:
1459         case IO_SCH_ORPH_ATTACH:
1460                 ccw_device_set_disconnected(cdev);
1461                 break;
1462         case IO_SCH_UNREG_ATTACH:
1463         case IO_SCH_UNREG:
1464                 if (!cdev)
1465                         break;
1466                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1467                         /*
1468                          * Note: delayed work triggered by this event
1469                          * and repeated calls to sch_event are synchronized
1470                          * by the above check for work_pending(cdev).
1471                          */
1472                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1473                 } else
1474                         ccw_device_set_notoper(cdev);
1475                 break;
1476         case IO_SCH_NOP:
1477                 rc = 0;
1478                 goto out_unlock;
1479         default:
1480                 break;
1481         }
1482         spin_unlock_irqrestore(sch->lock, flags);
1483         /* All other actions require process context. */
1484         if (!process)
1485                 goto out;
1486         /* Handle attached ccw device. */
1487         switch (action) {
1488         case IO_SCH_ORPH_UNREG:
1489         case IO_SCH_ORPH_ATTACH:
1490                 /* Move ccw device to orphanage. */
1491                 rc = ccw_device_move_to_orph(cdev);
1492                 if (rc)
1493                         goto out;
1494                 break;
1495         case IO_SCH_UNREG_ATTACH:
1496                 if (cdev->private->flags.resuming) {
1497                         /* Device will be handled later. */
1498                         rc = 0;
1499                         goto out;
1500                 }
1501                 /* Unregister ccw device. */
1502                 ccw_device_unregister(cdev);
1503                 break;
1504         default:
1505                 break;
1506         }
1507         /* Handle subchannel. */
1508         switch (action) {
1509         case IO_SCH_ORPH_UNREG:
1510         case IO_SCH_UNREG:
1511                 if (!cdev || !cdev->private->flags.resuming)
1512                         css_sch_device_unregister(sch);
1513                 break;
1514         case IO_SCH_ORPH_ATTACH:
1515         case IO_SCH_UNREG_ATTACH:
1516         case IO_SCH_ATTACH:
1517                 dev_id.ssid = sch->schid.ssid;
1518                 dev_id.devno = sch->schib.pmcw.dev;
1519                 cdev = get_ccwdev_by_dev_id(&dev_id);
1520                 if (!cdev) {
1521                         sch_create_and_recog_new_device(sch);
1522                         break;
1523                 }
1524                 rc = ccw_device_move_to_sch(cdev, sch);
1525                 if (rc) {
1526                         /* Release reference from get_ccwdev_by_dev_id() */
1527                         put_device(&cdev->dev);
1528                         goto out;
1529                 }
1530                 spin_lock_irqsave(sch->lock, flags);
1531                 ccw_device_trigger_reprobe(cdev);
1532                 spin_unlock_irqrestore(sch->lock, flags);
1533                 /* Release reference from get_ccwdev_by_dev_id() */
1534                 put_device(&cdev->dev);
1535                 break;
1536         default:
1537                 break;
1538         }
1539         return 0;
1540
1541 out_unlock:
1542         spin_unlock_irqrestore(sch->lock, flags);
1543 out:
1544         return rc;
1545 }
1546
1547 #ifdef CONFIG_CCW_CONSOLE
1548 static struct ccw_device console_cdev;
1549 static struct ccw_device_private console_private;
1550 static int console_cdev_in_use;
1551
1552 static DEFINE_SPINLOCK(ccw_console_lock);
1553
1554 spinlock_t * cio_get_console_lock(void)
1555 {
1556         return &ccw_console_lock;
1557 }
1558
1559 static int ccw_device_console_enable(struct ccw_device *cdev,
1560                                      struct subchannel *sch)
1561 {
1562         struct io_subchannel_private *io_priv = cio_get_console_priv();
1563         int rc;
1564
1565         /* Attach subchannel private data. */
1566         memset(io_priv, 0, sizeof(*io_priv));
1567         set_io_private(sch, io_priv);
1568         io_subchannel_init_fields(sch);
1569         rc = cio_commit_config(sch);
1570         if (rc)
1571                 return rc;
1572         sch->driver = &io_subchannel_driver;
1573         /* Initialize the ccw_device structure. */
1574         cdev->dev.parent= &sch->dev;
1575         sch_set_cdev(sch, cdev);
1576         io_subchannel_recog(cdev, sch);
1577         /* Now wait for the async. recognition to come to an end. */
1578         spin_lock_irq(cdev->ccwlock);
1579         while (!dev_fsm_final_state(cdev))
1580                 wait_cons_dev();
1581         rc = -EIO;
1582         if (cdev->private->state != DEV_STATE_OFFLINE)
1583                 goto out_unlock;
1584         ccw_device_online(cdev);
1585         while (!dev_fsm_final_state(cdev))
1586                 wait_cons_dev();
1587         if (cdev->private->state != DEV_STATE_ONLINE)
1588                 goto out_unlock;
1589         rc = 0;
1590 out_unlock:
1591         spin_unlock_irq(cdev->ccwlock);
1592         return rc;
1593 }
1594
1595 struct ccw_device *
1596 ccw_device_probe_console(void)
1597 {
1598         struct subchannel *sch;
1599         int ret;
1600
1601         if (xchg(&console_cdev_in_use, 1) != 0)
1602                 return ERR_PTR(-EBUSY);
1603         sch = cio_probe_console();
1604         if (IS_ERR(sch)) {
1605                 console_cdev_in_use = 0;
1606                 return (void *) sch;
1607         }
1608         memset(&console_cdev, 0, sizeof(struct ccw_device));
1609         memset(&console_private, 0, sizeof(struct ccw_device_private));
1610         console_cdev.private = &console_private;
1611         console_private.cdev = &console_cdev;
1612         ret = ccw_device_console_enable(&console_cdev, sch);
1613         if (ret) {
1614                 cio_release_console();
1615                 console_cdev_in_use = 0;
1616                 return ERR_PTR(ret);
1617         }
1618         console_cdev.online = 1;
1619         return &console_cdev;
1620 }
1621
1622 static int ccw_device_pm_restore(struct device *dev);
1623
1624 int ccw_device_force_console(void)
1625 {
1626         if (!console_cdev_in_use)
1627                 return -ENODEV;
1628         return ccw_device_pm_restore(&console_cdev.dev);
1629 }
1630 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1631 #endif
1632
1633 /*
1634  * get ccw_device matching the busid, but only if owned by cdrv
1635  */
1636 static int
1637 __ccwdev_check_busid(struct device *dev, void *id)
1638 {
1639         char *bus_id;
1640
1641         bus_id = id;
1642
1643         return (strcmp(bus_id, dev_name(dev)) == 0);
1644 }
1645
1646
1647 /**
1648  * get_ccwdev_by_busid() - obtain device from a bus id
1649  * @cdrv: driver the device is owned by
1650  * @bus_id: bus id of the device to be searched
1651  *
1652  * This function searches all devices owned by @cdrv for a device with a bus
1653  * id matching @bus_id.
1654  * Returns:
1655  *  If a match is found, its reference count of the found device is increased
1656  *  and it is returned; else %NULL is returned.
1657  */
1658 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1659                                        const char *bus_id)
1660 {
1661         struct device *dev;
1662         struct device_driver *drv;
1663
1664         drv = get_driver(&cdrv->driver);
1665         if (!drv)
1666                 return NULL;
1667
1668         dev = driver_find_device(drv, NULL, (void *)bus_id,
1669                                  __ccwdev_check_busid);
1670         put_driver(drv);
1671
1672         return dev ? to_ccwdev(dev) : NULL;
1673 }
1674
1675 /************************** device driver handling ************************/
1676
1677 /* This is the implementation of the ccw_driver class. The probe, remove
1678  * and release methods are initially very similar to the device_driver
1679  * implementations, with the difference that they have ccw_device
1680  * arguments.
1681  *
1682  * A ccw driver also contains the information that is needed for
1683  * device matching.
1684  */
1685 static int
1686 ccw_device_probe (struct device *dev)
1687 {
1688         struct ccw_device *cdev = to_ccwdev(dev);
1689         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1690         int ret;
1691
1692         cdev->drv = cdrv; /* to let the driver call _set_online */
1693
1694         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1695
1696         if (ret) {
1697                 cdev->drv = NULL;
1698                 return ret;
1699         }
1700
1701         return 0;
1702 }
1703
1704 static int
1705 ccw_device_remove (struct device *dev)
1706 {
1707         struct ccw_device *cdev = to_ccwdev(dev);
1708         struct ccw_driver *cdrv = cdev->drv;
1709         int ret;
1710
1711         if (cdrv->remove)
1712                 cdrv->remove(cdev);
1713         if (cdev->online) {
1714                 cdev->online = 0;
1715                 spin_lock_irq(cdev->ccwlock);
1716                 ret = ccw_device_offline(cdev);
1717                 spin_unlock_irq(cdev->ccwlock);
1718                 if (ret == 0)
1719                         wait_event(cdev->private->wait_q,
1720                                    dev_fsm_final_state(cdev));
1721                 else
1722                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1723                                       "device 0.%x.%04x\n",
1724                                       ret, cdev->private->dev_id.ssid,
1725                                       cdev->private->dev_id.devno);
1726                 /* Give up reference obtained in ccw_device_set_online(). */
1727                 put_device(&cdev->dev);
1728         }
1729         ccw_device_set_timeout(cdev, 0);
1730         cdev->drv = NULL;
1731         return 0;
1732 }
1733
1734 static void ccw_device_shutdown(struct device *dev)
1735 {
1736         struct ccw_device *cdev;
1737
1738         cdev = to_ccwdev(dev);
1739         if (cdev->drv && cdev->drv->shutdown)
1740                 cdev->drv->shutdown(cdev);
1741         disable_cmf(cdev);
1742 }
1743
1744 static int ccw_device_pm_prepare(struct device *dev)
1745 {
1746         struct ccw_device *cdev = to_ccwdev(dev);
1747
1748         if (work_pending(&cdev->private->todo_work))
1749                 return -EAGAIN;
1750         /* Fail while device is being set online/offline. */
1751         if (atomic_read(&cdev->private->onoff))
1752                 return -EAGAIN;
1753
1754         if (cdev->online && cdev->drv && cdev->drv->prepare)
1755                 return cdev->drv->prepare(cdev);
1756
1757         return 0;
1758 }
1759
1760 static void ccw_device_pm_complete(struct device *dev)
1761 {
1762         struct ccw_device *cdev = to_ccwdev(dev);
1763
1764         if (cdev->online && cdev->drv && cdev->drv->complete)
1765                 cdev->drv->complete(cdev);
1766 }
1767
1768 static int ccw_device_pm_freeze(struct device *dev)
1769 {
1770         struct ccw_device *cdev = to_ccwdev(dev);
1771         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1772         int ret, cm_enabled;
1773
1774         /* Fail suspend while device is in transistional state. */
1775         if (!dev_fsm_final_state(cdev))
1776                 return -EAGAIN;
1777         if (!cdev->online)
1778                 return 0;
1779         if (cdev->drv && cdev->drv->freeze) {
1780                 ret = cdev->drv->freeze(cdev);
1781                 if (ret)
1782                         return ret;
1783         }
1784
1785         spin_lock_irq(sch->lock);
1786         cm_enabled = cdev->private->cmb != NULL;
1787         spin_unlock_irq(sch->lock);
1788         if (cm_enabled) {
1789                 /* Don't have the css write on memory. */
1790                 ret = ccw_set_cmf(cdev, 0);
1791                 if (ret)
1792                         return ret;
1793         }
1794         /* From here on, disallow device driver I/O. */
1795         spin_lock_irq(sch->lock);
1796         ret = cio_disable_subchannel(sch);
1797         spin_unlock_irq(sch->lock);
1798
1799         return ret;
1800 }
1801
1802 static int ccw_device_pm_thaw(struct device *dev)
1803 {
1804         struct ccw_device *cdev = to_ccwdev(dev);
1805         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1806         int ret, cm_enabled;
1807
1808         if (!cdev->online)
1809                 return 0;
1810
1811         spin_lock_irq(sch->lock);
1812         /* Allow device driver I/O again. */
1813         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1814         cm_enabled = cdev->private->cmb != NULL;
1815         spin_unlock_irq(sch->lock);
1816         if (ret)
1817                 return ret;
1818
1819         if (cm_enabled) {
1820                 ret = ccw_set_cmf(cdev, 1);
1821                 if (ret)
1822                         return ret;
1823         }
1824
1825         if (cdev->drv && cdev->drv->thaw)
1826                 ret = cdev->drv->thaw(cdev);
1827
1828         return ret;
1829 }
1830
1831 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1832 {
1833         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1834
1835         spin_lock_irq(sch->lock);
1836         if (cio_is_console(sch->schid)) {
1837                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1838                 goto out_unlock;
1839         }
1840         /*
1841          * While we were sleeping, devices may have gone or become
1842          * available again. Kick re-detection.
1843          */
1844         cdev->private->flags.resuming = 1;
1845         cdev->private->path_new_mask = LPM_ANYPATH;
1846         css_schedule_eval(sch->schid);
1847         spin_unlock_irq(sch->lock);
1848         css_complete_work();
1849
1850         /* cdev may have been moved to a different subchannel. */
1851         sch = to_subchannel(cdev->dev.parent);
1852         spin_lock_irq(sch->lock);
1853         if (cdev->private->state != DEV_STATE_ONLINE &&
1854             cdev->private->state != DEV_STATE_OFFLINE)
1855                 goto out_unlock;
1856
1857         ccw_device_recognition(cdev);
1858         spin_unlock_irq(sch->lock);
1859         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1860                    cdev->private->state == DEV_STATE_DISCONNECTED);
1861         spin_lock_irq(sch->lock);
1862
1863 out_unlock:
1864         cdev->private->flags.resuming = 0;
1865         spin_unlock_irq(sch->lock);
1866 }
1867
1868 static int resume_handle_boxed(struct ccw_device *cdev)
1869 {
1870         cdev->private->state = DEV_STATE_BOXED;
1871         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1872                 return 0;
1873         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1874         return -ENODEV;
1875 }
1876
1877 static int resume_handle_disc(struct ccw_device *cdev)
1878 {
1879         cdev->private->state = DEV_STATE_DISCONNECTED;
1880         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1881                 return 0;
1882         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1883         return -ENODEV;
1884 }
1885
1886 static int ccw_device_pm_restore(struct device *dev)
1887 {
1888         struct ccw_device *cdev = to_ccwdev(dev);
1889         struct subchannel *sch;
1890         int ret = 0;
1891
1892         __ccw_device_pm_restore(cdev);
1893         sch = to_subchannel(cdev->dev.parent);
1894         spin_lock_irq(sch->lock);
1895         if (cio_is_console(sch->schid))
1896                 goto out_restore;
1897
1898         /* check recognition results */
1899         switch (cdev->private->state) {
1900         case DEV_STATE_OFFLINE:
1901         case DEV_STATE_ONLINE:
1902                 cdev->private->flags.donotify = 0;
1903                 break;
1904         case DEV_STATE_BOXED:
1905                 ret = resume_handle_boxed(cdev);
1906                 if (ret)
1907                         goto out_unlock;
1908                 goto out_restore;
1909         default:
1910                 ret = resume_handle_disc(cdev);
1911                 if (ret)
1912                         goto out_unlock;
1913                 goto out_restore;
1914         }
1915         /* check if the device type has changed */
1916         if (!ccw_device_test_sense_data(cdev)) {
1917                 ccw_device_update_sense_data(cdev);
1918                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1919                 ret = -ENODEV;
1920                 goto out_unlock;
1921         }
1922         if (!cdev->online)
1923                 goto out_unlock;
1924
1925         if (ccw_device_online(cdev)) {
1926                 ret = resume_handle_disc(cdev);
1927                 if (ret)
1928                         goto out_unlock;
1929                 goto out_restore;
1930         }
1931         spin_unlock_irq(sch->lock);
1932         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1933         spin_lock_irq(sch->lock);
1934
1935         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1936                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1937                 ret = -ENODEV;
1938                 goto out_unlock;
1939         }
1940
1941         /* reenable cmf, if needed */
1942         if (cdev->private->cmb) {
1943                 spin_unlock_irq(sch->lock);
1944                 ret = ccw_set_cmf(cdev, 1);
1945                 spin_lock_irq(sch->lock);
1946                 if (ret) {
1947                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1948                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1949                                       cdev->private->dev_id.devno, ret);
1950                         ret = 0;
1951                 }
1952         }
1953
1954 out_restore:
1955         spin_unlock_irq(sch->lock);
1956         if (cdev->online && cdev->drv && cdev->drv->restore)
1957                 ret = cdev->drv->restore(cdev);
1958         return ret;
1959
1960 out_unlock:
1961         spin_unlock_irq(sch->lock);
1962         return ret;
1963 }
1964
1965 static const struct dev_pm_ops ccw_pm_ops = {
1966         .prepare = ccw_device_pm_prepare,
1967         .complete = ccw_device_pm_complete,
1968         .freeze = ccw_device_pm_freeze,
1969         .thaw = ccw_device_pm_thaw,
1970         .restore = ccw_device_pm_restore,
1971 };
1972
1973 static struct bus_type ccw_bus_type = {
1974         .name   = "ccw",
1975         .match  = ccw_bus_match,
1976         .uevent = ccw_uevent,
1977         .probe  = ccw_device_probe,
1978         .remove = ccw_device_remove,
1979         .shutdown = ccw_device_shutdown,
1980         .pm = &ccw_pm_ops,
1981 };
1982
1983 /**
1984  * ccw_driver_register() - register a ccw driver
1985  * @cdriver: driver to be registered
1986  *
1987  * This function is mainly a wrapper around driver_register().
1988  * Returns:
1989  *   %0 on success and a negative error value on failure.
1990  */
1991 int ccw_driver_register(struct ccw_driver *cdriver)
1992 {
1993         struct device_driver *drv = &cdriver->driver;
1994
1995         drv->bus = &ccw_bus_type;
1996
1997         return driver_register(drv);
1998 }
1999
2000 /**
2001  * ccw_driver_unregister() - deregister a ccw driver
2002  * @cdriver: driver to be deregistered
2003  *
2004  * This function is mainly a wrapper around driver_unregister().
2005  */
2006 void ccw_driver_unregister(struct ccw_driver *cdriver)
2007 {
2008         driver_unregister(&cdriver->driver);
2009 }
2010
2011 /* Helper func for qdio. */
2012 struct subchannel_id
2013 ccw_device_get_subchannel_id(struct ccw_device *cdev)
2014 {
2015         struct subchannel *sch;
2016
2017         sch = to_subchannel(cdev->dev.parent);
2018         return sch->schid;
2019 }
2020
2021 static void ccw_device_todo(struct work_struct *work)
2022 {
2023         struct ccw_device_private *priv;
2024         struct ccw_device *cdev;
2025         struct subchannel *sch;
2026         enum cdev_todo todo;
2027
2028         priv = container_of(work, struct ccw_device_private, todo_work);
2029         cdev = priv->cdev;
2030         sch = to_subchannel(cdev->dev.parent);
2031         /* Find out todo. */
2032         spin_lock_irq(cdev->ccwlock);
2033         todo = priv->todo;
2034         priv->todo = CDEV_TODO_NOTHING;
2035         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2036                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2037         spin_unlock_irq(cdev->ccwlock);
2038         /* Perform todo. */
2039         switch (todo) {
2040         case CDEV_TODO_ENABLE_CMF:
2041                 cmf_reenable(cdev);
2042                 break;
2043         case CDEV_TODO_REBIND:
2044                 ccw_device_do_unbind_bind(cdev);
2045                 break;
2046         case CDEV_TODO_REGISTER:
2047                 io_subchannel_register(cdev);
2048                 break;
2049         case CDEV_TODO_UNREG_EVAL:
2050                 if (!sch_is_pseudo_sch(sch))
2051                         css_schedule_eval(sch->schid);
2052                 /* fall-through */
2053         case CDEV_TODO_UNREG:
2054                 if (sch_is_pseudo_sch(sch))
2055                         ccw_device_unregister(cdev);
2056                 else
2057                         ccw_device_call_sch_unregister(cdev);
2058                 break;
2059         default:
2060                 break;
2061         }
2062         /* Release workqueue ref. */
2063         put_device(&cdev->dev);
2064 }
2065
2066 /**
2067  * ccw_device_sched_todo - schedule ccw device operation
2068  * @cdev: ccw device
2069  * @todo: todo
2070  *
2071  * Schedule the operation identified by @todo to be performed on the slow path
2072  * workqueue. Do nothing if another operation with higher priority is already
2073  * scheduled. Needs to be called with ccwdev lock held.
2074  */
2075 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2076 {
2077         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2078                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2079                       todo);
2080         if (cdev->private->todo >= todo)
2081                 return;
2082         cdev->private->todo = todo;
2083         /* Get workqueue ref. */
2084         if (!get_device(&cdev->dev))
2085                 return;
2086         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2087                 /* Already queued, release workqueue ref. */
2088                 put_device(&cdev->dev);
2089         }
2090 }
2091
2092 /**
2093  * ccw_device_siosl() - initiate logging
2094  * @cdev: ccw device
2095  *
2096  * This function is used to invoke model-dependent logging within the channel
2097  * subsystem.
2098  */
2099 int ccw_device_siosl(struct ccw_device *cdev)
2100 {
2101         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2102
2103         return chsc_siosl(sch->schid);
2104 }
2105 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2106
2107 MODULE_LICENSE("GPL");
2108 EXPORT_SYMBOL(ccw_device_set_online);
2109 EXPORT_SYMBOL(ccw_device_set_offline);
2110 EXPORT_SYMBOL(ccw_driver_register);
2111 EXPORT_SYMBOL(ccw_driver_unregister);
2112 EXPORT_SYMBOL(get_ccwdev_by_busid);
2113 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);