drivers/s390/cio/device.c

   1 /*
   2  *  bus driver for ccw devices
   3  *
   4  *    Copyright IBM Corp. 2002, 2008
   5  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   6  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8  *
   9  * License: GPL
  10  */
  11
  12 #define KMSG_COMPONENT "cio"
  13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  14
  15 #include <linux/export.h>
  16 #include <linux/init.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/errno.h>
  19 #include <linux/err.h>
  20 #include <linux/slab.h>
  21 #include <linux/list.h>
  22 #include <linux/device.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/delay.h>
  25 #include <linux/timer.h>
  26 #include <linux/kernel_stat.h>
  27 #include <linux/sched/signal.h>
  28
  29 #include <asm/ccwdev.h>
  30 #include <asm/cio.h>
  31 #include <asm/param.h>          /* HZ */
  32 #include <asm/cmb.h>
  33 #include <asm/isc.h>
  34
  35 #include "chp.h"
  36 #include "cio.h"
  37 #include "cio_debug.h"
  38 #include "css.h"
  39 #include "device.h"
  40 #include "ioasm.h"
  41 #include "io_sch.h"
  42 #include "blacklist.h"
  43 #include "chsc.h"
  44
  45 static struct timer_list recovery_timer;
  46 static DEFINE_SPINLOCK(recovery_lock);
  47 static int recovery_phase;
  48 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  49
  50 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
  51 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
  52 static struct bus_type ccw_bus_type;
  53
  54 /******************* bus type handling ***********************/
  55
  56 /* The Linux driver model distinguishes between a bus type and
  57  * the bus itself. Of course we only have one channel
  58  * subsystem driver and one channel system per machine, but
  59  * we still use the abstraction. T.R. says it's a good idea. */
  60 static int
  61 ccw_bus_match (struct device * dev, struct device_driver * drv)
  62 {
  63         struct ccw_device *cdev = to_ccwdev(dev);
  64         struct ccw_driver *cdrv = to_ccwdrv(drv);
  65         const struct ccw_device_id *ids = cdrv->ids, *found;
  66
  67         if (!ids)
  68                 return 0;
  69
  70         found = ccw_device_id_match(ids, &cdev->id);
  71         if (!found)
  72                 return 0;
  73
  74         cdev->id.driver_info = found->driver_info;
  75
  76         return 1;
  77 }
  78
  79 /* Store modalias string delimited by prefix/suffix string into buffer with
  80  * specified size. Return length of resulting string (excluding trailing '\0')
  81  * even if string doesn't fit buffer (snprintf semantics). */
  82 static int snprint_alias(char *buf, size_t size,
  83                          struct ccw_device_id *id, const char *suffix)
  84 {
  85         int len;
  86
  87         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  88         if (len > size)
  89                 return len;
  90         buf += len;
  91         size -= len;
  92
  93         if (id->dev_type != 0)
  94                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  95                                 id->dev_model, suffix);
  96         else
  97                 len += snprintf(buf, size, "dtdm%s", suffix);
  98
  99         return len;
 100 }
 101
 102 /* Set up environment variables for ccw device uevent. Return 0 on success,
 103  * non-zero otherwise. */
 104 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
 105 {
 106         struct ccw_device *cdev = to_ccwdev(dev);
 107         struct ccw_device_id *id = &(cdev->id);
 108         int ret;
 109         char modalias_buf[30];
 110
 111         /* CU_TYPE= */
 112         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 113         if (ret)
 114                 return ret;
 115
 116         /* CU_MODEL= */
 117         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 118         if (ret)
 119                 return ret;
 120
 121         /* The next two can be zero, that's ok for us */
 122         /* DEV_TYPE= */
 123         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 124         if (ret)
 125                 return ret;
 126
 127         /* DEV_MODEL= */
 128         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 129         if (ret)
 130                 return ret;
 131
 132         /* MODALIAS=  */
 133         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 134         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 135         return ret;
 136 }
 137
 138 static void io_subchannel_irq(struct subchannel *);
 139 static int io_subchannel_probe(struct subchannel *);
 140 static int io_subchannel_remove(struct subchannel *);
 141 static void io_subchannel_shutdown(struct subchannel *);
 142 static int io_subchannel_sch_event(struct subchannel *, int);
 143 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 144                                    int);
 145 static void recovery_func(unsigned long data);
 146
 147 static struct css_device_id io_subchannel_ids[] = {
 148         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 149         { /* end of list */ },
 150 };
 151
 152 static int io_subchannel_prepare(struct subchannel *sch)
 153 {
 154         struct ccw_device *cdev;
 155         /*
 156          * Don't allow suspend while a ccw device registration
 157          * is still outstanding.
 158          */
 159         cdev = sch_get_cdev(sch);
 160         if (cdev && !device_is_registered(&cdev->dev))
 161                 return -EAGAIN;
 162         return 0;
 163 }
 164
 165 static int io_subchannel_settle(void)
 166 {
 167         int ret;
 168
 169         ret = wait_event_interruptible(ccw_device_init_wq,
 170                                 atomic_read(&ccw_device_init_count) == 0);
 171         if (ret)
 172                 return -EINTR;
 173         flush_workqueue(cio_work_q);
 174         return 0;
 175 }
 176
 177 static struct css_driver io_subchannel_driver = {
 178         .drv = {
 179                 .owner = THIS_MODULE,
 180                 .name = "io_subchannel",
 181         },
 182         .subchannel_type = io_subchannel_ids,
 183         .irq = io_subchannel_irq,
 184         .sch_event = io_subchannel_sch_event,
 185         .chp_event = io_subchannel_chp_event,
 186         .probe = io_subchannel_probe,
 187         .remove = io_subchannel_remove,
 188         .shutdown = io_subchannel_shutdown,
 189         .prepare = io_subchannel_prepare,
 190         .settle = io_subchannel_settle,
 191 };
 192
 193 int __init io_subchannel_init(void)
 194 {
 195         int ret;
 196
 197         setup_timer(&recovery_timer, recovery_func, 0);
 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 static ssize_t
 212 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 213 {
 214         struct ccw_device *cdev = to_ccwdev(dev);
 215         struct ccw_device_id *id = &(cdev->id);
 216
 217         if (id->dev_type != 0)
 218                 return sprintf(buf, "%04x/%02x\n",
 219                                 id->dev_type, id->dev_model);
 220         else
 221                 return sprintf(buf, "n/a\n");
 222 }
 223
 224 static ssize_t
 225 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 226 {
 227         struct ccw_device *cdev = to_ccwdev(dev);
 228         struct ccw_device_id *id = &(cdev->id);
 229
 230         return sprintf(buf, "%04x/%02x\n",
 231                        id->cu_type, id->cu_model);
 232 }
 233
 234 static ssize_t
 235 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 236 {
 237         struct ccw_device *cdev = to_ccwdev(dev);
 238         struct ccw_device_id *id = &(cdev->id);
 239         int len;
 240
 241         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 242
 243         return len > PAGE_SIZE ? PAGE_SIZE : len;
 244 }
 245
 246 static ssize_t
 247 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 248 {
 249         struct ccw_device *cdev = to_ccwdev(dev);
 250
 251         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 252 }
 253
 254 int ccw_device_is_orphan(struct ccw_device *cdev)
 255 {
 256         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 257 }
 258
 259 static void ccw_device_unregister(struct ccw_device *cdev)
 260 {
 261         if (device_is_registered(&cdev->dev)) {
 262                 /* Undo device_add(). */
 263                 device_del(&cdev->dev);
 264         }
 265         if (cdev->private->flags.initialized) {
 266                 cdev->private->flags.initialized = 0;
 267                 /* Release reference from device_initialize(). */
 268                 put_device(&cdev->dev);
 269         }
 270 }
 271
 272 static void io_subchannel_quiesce(struct subchannel *);
 273
 274 /**
 275  * ccw_device_set_offline() - disable a ccw device for I/O
 276  * @cdev: target ccw device
 277  *
 278  * This function calls the driver's set_offline() function for @cdev, if
 279  * given, and then disables @cdev.
 280  * Returns:
 281  *   %0 on success and a negative error value on failure.
 282  * Context:
 283  *  enabled, ccw device lock not held
 284  */
 285 int ccw_device_set_offline(struct ccw_device *cdev)
 286 {
 287         struct subchannel *sch;
 288         int ret, state;
 289
 290         if (!cdev)
 291                 return -ENODEV;
 292         if (!cdev->online || !cdev->drv)
 293                 return -EINVAL;
 294
 295         if (cdev->drv->set_offline) {
 296                 ret = cdev->drv->set_offline(cdev);
 297                 if (ret != 0)
 298                         return ret;
 299         }
 300         spin_lock_irq(cdev->ccwlock);
 301         sch = to_subchannel(cdev->dev.parent);
 302         cdev->online = 0;
 303         /* Wait until a final state or DISCONNECTED is reached */
 304         while (!dev_fsm_final_state(cdev) &&
 305                cdev->private->state != DEV_STATE_DISCONNECTED) {
 306                 spin_unlock_irq(cdev->ccwlock);
 307                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 308                            cdev->private->state == DEV_STATE_DISCONNECTED));
 309                 spin_lock_irq(cdev->ccwlock);
 310         }
 311         do {
 312                 ret = ccw_device_offline(cdev);
 313                 if (!ret)
 314                         break;
 315                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 316                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 317                               cdev->private->dev_id.devno);
 318                 if (ret != -EBUSY)
 319                         goto error;
 320                 state = cdev->private->state;
 321                 spin_unlock_irq(cdev->ccwlock);
 322                 io_subchannel_quiesce(sch);
 323                 spin_lock_irq(cdev->ccwlock);
 324                 cdev->private->state = state;
 325         } while (ret == -EBUSY);
 326         spin_unlock_irq(cdev->ccwlock);
 327         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 328                    cdev->private->state == DEV_STATE_DISCONNECTED));
 329         /* Inform the user if set offline failed. */
 330         if (cdev->private->state == DEV_STATE_BOXED) {
 331                 pr_warn("%s: The device entered boxed state while being set offline\n",
 332                         dev_name(&cdev->dev));
 333         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 334                 pr_warn("%s: The device stopped operating while being set offline\n",
 335                         dev_name(&cdev->dev));
 336         }
 337         /* Give up reference from ccw_device_set_online(). */
 338         put_device(&cdev->dev);
 339         return 0;
 340
 341 error:
 342         cdev->private->state = DEV_STATE_OFFLINE;
 343         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 344         spin_unlock_irq(cdev->ccwlock);
 345         /* Give up reference from ccw_device_set_online(). */
 346         put_device(&cdev->dev);
 347         return -ENODEV;
 348 }
 349
 350 /**
 351  * ccw_device_set_online() - enable a ccw device for I/O
 352  * @cdev: target ccw device
 353  *
 354  * This function first enables @cdev and then calls the driver's set_online()
 355  * function for @cdev, if given. If set_online() returns an error, @cdev is
 356  * disabled again.
 357  * Returns:
 358  *   %0 on success and a negative error value on failure.
 359  * Context:
 360  *  enabled, ccw device lock not held
 361  */
 362 int ccw_device_set_online(struct ccw_device *cdev)
 363 {
 364         int ret;
 365         int ret2;
 366
 367         if (!cdev)
 368                 return -ENODEV;
 369         if (cdev->online || !cdev->drv)
 370                 return -EINVAL;
 371         /* Hold on to an extra reference while device is online. */
 372         if (!get_device(&cdev->dev))
 373                 return -ENODEV;
 374
 375         spin_lock_irq(cdev->ccwlock);
 376         ret = ccw_device_online(cdev);
 377         spin_unlock_irq(cdev->ccwlock);
 378         if (ret == 0)
 379                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 380         else {
 381                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 382                               "device 0.%x.%04x\n",
 383                               ret, cdev->private->dev_id.ssid,
 384                               cdev->private->dev_id.devno);
 385                 /* Give up online reference since onlining failed. */
 386                 put_device(&cdev->dev);
 387                 return ret;
 388         }
 389         spin_lock_irq(cdev->ccwlock);
 390         /* Check if online processing was successful */
 391         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 392             (cdev->private->state != DEV_STATE_W4SENSE)) {
 393                 spin_unlock_irq(cdev->ccwlock);
 394                 /* Inform the user that set online failed. */
 395                 if (cdev->private->state == DEV_STATE_BOXED) {
 396                         pr_warn("%s: Setting the device online failed because it is boxed\n",
 397                                 dev_name(&cdev->dev));
 398                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 399                         pr_warn("%s: Setting the device online failed because it is not operational\n",
 400                                 dev_name(&cdev->dev));
 401                 }
 402                 /* Give up online reference since onlining failed. */
 403                 put_device(&cdev->dev);
 404                 return -ENODEV;
 405         }
 406         spin_unlock_irq(cdev->ccwlock);
 407         if (cdev->drv->set_online)
 408                 ret = cdev->drv->set_online(cdev);
 409         if (ret)
 410                 goto rollback;
 411
 412         spin_lock_irq(cdev->ccwlock);
 413         cdev->online = 1;
 414         spin_unlock_irq(cdev->ccwlock);
 415         return 0;
 416
 417 rollback:
 418         spin_lock_irq(cdev->ccwlock);
 419         /* Wait until a final state or DISCONNECTED is reached */
 420         while (!dev_fsm_final_state(cdev) &&
 421                cdev->private->state != DEV_STATE_DISCONNECTED) {
 422                 spin_unlock_irq(cdev->ccwlock);
 423                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 424                            cdev->private->state == DEV_STATE_DISCONNECTED));
 425                 spin_lock_irq(cdev->ccwlock);
 426         }
 427         ret2 = ccw_device_offline(cdev);
 428         if (ret2)
 429                 goto error;
 430         spin_unlock_irq(cdev->ccwlock);
 431         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 432                    cdev->private->state == DEV_STATE_DISCONNECTED));
 433         /* Give up online reference since onlining failed. */
 434         put_device(&cdev->dev);
 435         return ret;
 436
 437 error:
 438         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 439                       "device 0.%x.%04x\n",
 440                       ret2, cdev->private->dev_id.ssid,
 441                       cdev->private->dev_id.devno);
 442         cdev->private->state = DEV_STATE_OFFLINE;
 443         spin_unlock_irq(cdev->ccwlock);
 444         /* Give up online reference since onlining failed. */
 445         put_device(&cdev->dev);
 446         return ret;
 447 }
 448
 449 static int online_store_handle_offline(struct ccw_device *cdev)
 450 {
 451         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 452                 spin_lock_irq(cdev->ccwlock);
 453                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 454                 spin_unlock_irq(cdev->ccwlock);
 455                 return 0;
 456         }
 457         if (cdev->drv && cdev->drv->set_offline)
 458                 return ccw_device_set_offline(cdev);
 459         return -EINVAL;
 460 }
 461
 462 static int online_store_recog_and_online(struct ccw_device *cdev)
 463 {
 464         /* Do device recognition, if needed. */
 465         if (cdev->private->state == DEV_STATE_BOXED) {
 466                 spin_lock_irq(cdev->ccwlock);
 467                 ccw_device_recognition(cdev);
 468                 spin_unlock_irq(cdev->ccwlock);
 469                 wait_event(cdev->private->wait_q,
 470                            cdev->private->flags.recog_done);
 471                 if (cdev->private->state != DEV_STATE_OFFLINE)
 472                         /* recognition failed */
 473                         return -EAGAIN;
 474         }
 475         if (cdev->drv && cdev->drv->set_online)
 476                 return ccw_device_set_online(cdev);
 477         return -EINVAL;
 478 }
 479
 480 static int online_store_handle_online(struct ccw_device *cdev, int force)
 481 {
 482         int ret;
 483
 484         ret = online_store_recog_and_online(cdev);
 485         if (ret && !force)
 486                 return ret;
 487         if (force && cdev->private->state == DEV_STATE_BOXED) {
 488                 ret = ccw_device_stlck(cdev);
 489                 if (ret)
 490                         return ret;
 491                 if (cdev->id.cu_type == 0)
 492                         cdev->private->state = DEV_STATE_NOT_OPER;
 493                 ret = online_store_recog_and_online(cdev);
 494                 if (ret)
 495                         return ret;
 496         }
 497         return 0;
 498 }
 499
 500 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 501                              const char *buf, size_t count)
 502 {
 503         struct ccw_device *cdev = to_ccwdev(dev);
 504         int force, ret;
 505         unsigned long i;
 506
 507         /* Prevent conflict between multiple on-/offline processing requests. */
 508         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 509                 return -EAGAIN;
 510         /* Prevent conflict between internal I/Os and on-/offline processing. */
 511         if (!dev_fsm_final_state(cdev) &&
 512             cdev->private->state != DEV_STATE_DISCONNECTED) {
 513                 ret = -EAGAIN;
 514                 goto out;
 515         }
 516         /* Prevent conflict between pending work and on-/offline processing.*/
 517         if (work_pending(&cdev->private->todo_work)) {
 518                 ret = -EAGAIN;
 519                 goto out;
 520         }
 521         if (!strncmp(buf, "force\n", count)) {
 522                 force = 1;
 523                 i = 1;
 524                 ret = 0;
 525         } else {
 526                 force = 0;
 527                 ret = kstrtoul(buf, 16, &i);
 528         }
 529         if (ret)
 530                 goto out;
 531
 532         device_lock(dev);
 533         switch (i) {
 534         case 0:
 535                 ret = online_store_handle_offline(cdev);
 536                 break;
 537         case 1:
 538                 ret = online_store_handle_online(cdev, force);
 539                 break;
 540         default:
 541                 ret = -EINVAL;
 542         }
 543         device_unlock(dev);
 544
 545 out:
 546         atomic_set(&cdev->private->onoff, 0);
 547         return (ret < 0) ? ret : count;
 548 }
 549
 550 static ssize_t
 551 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 552 {
 553         struct ccw_device *cdev = to_ccwdev(dev);
 554         struct subchannel *sch;
 555
 556         if (ccw_device_is_orphan(cdev))
 557                 return sprintf(buf, "no device\n");
 558         switch (cdev->private->state) {
 559         case DEV_STATE_BOXED:
 560                 return sprintf(buf, "boxed\n");
 561         case DEV_STATE_DISCONNECTED:
 562         case DEV_STATE_DISCONNECTED_SENSE_ID:
 563         case DEV_STATE_NOT_OPER:
 564                 sch = to_subchannel(dev->parent);
 565                 if (!sch->lpm)
 566                         return sprintf(buf, "no path\n");
 567                 else
 568                         return sprintf(buf, "no device\n");
 569         default:
 570                 /* All other states considered fine. */
 571                 return sprintf(buf, "good\n");
 572         }
 573 }
 574
 575 static ssize_t
 576 initiate_logging(struct device *dev, struct device_attribute *attr,
 577                  const char *buf, size_t count)
 578 {
 579         struct subchannel *sch = to_subchannel(dev);
 580         int rc;
 581
 582         rc = chsc_siosl(sch->schid);
 583         if (rc < 0) {
 584                 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
 585                         sch->schid.ssid, sch->schid.sch_no, rc);
 586                 return rc;
 587         }
 588         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 589                   sch->schid.ssid, sch->schid.sch_no);
 590         return count;
 591 }
 592
 593 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 594                         char *buf)
 595 {
 596         struct subchannel *sch = to_subchannel(dev);
 597
 598         return sprintf(buf, "%02x\n", sch->vpm);
 599 }
 600
 601 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 602 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 603 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 604 static DEVICE_ATTR(online, 0644, online_show, online_store);
 605 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 606 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 607 static DEVICE_ATTR(vpm, 0444, vpm_show, NULL);
 608
 609 static struct attribute *io_subchannel_attrs[] = {
 610         &dev_attr_logging.attr,
 611         &dev_attr_vpm.attr,
 612         NULL,
 613 };
 614
 615 static const struct attribute_group io_subchannel_attr_group = {
 616         .attrs = io_subchannel_attrs,
 617 };
 618
 619 static struct attribute * ccwdev_attrs[] = {
 620         &dev_attr_devtype.attr,
 621         &dev_attr_cutype.attr,
 622         &dev_attr_modalias.attr,
 623         &dev_attr_online.attr,
 624         &dev_attr_cmb_enable.attr,
 625         &dev_attr_availability.attr,
 626         NULL,
 627 };
 628
 629 static const struct attribute_group ccwdev_attr_group = {
 630         .attrs = ccwdev_attrs,
 631 };
 632
 633 static const struct attribute_group *ccwdev_attr_groups[] = {
 634         &ccwdev_attr_group,
 635         NULL,
 636 };
 637
 638 static int ccw_device_add(struct ccw_device *cdev)
 639 {
 640         struct device *dev = &cdev->dev;
 641
 642         dev->bus = &ccw_bus_type;
 643         return device_add(dev);
 644 }
 645
 646 static int match_dev_id(struct device *dev, void *data)
 647 {
 648         struct ccw_device *cdev = to_ccwdev(dev);
 649         struct ccw_dev_id *dev_id = data;
 650
 651         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 652 }
 653
 654 /**
 655  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 656  * @dev_id: id of the device to be searched
 657  *
 658  * This function searches all devices attached to the ccw bus for a device
 659  * matching @dev_id.
 660  * Returns:
 661  *  If a device is found its reference count is increased and returned;
 662  *  else %NULL is returned.
 663  */
 664 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 665 {
 666         struct device *dev;
 667
 668         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 669
 670         return dev ? to_ccwdev(dev) : NULL;
 671 }
 672 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 673
 674 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 675 {
 676         int ret;
 677
 678         if (device_is_registered(&cdev->dev)) {
 679                 device_release_driver(&cdev->dev);
 680                 ret = device_attach(&cdev->dev);
 681                 WARN_ON(ret == -ENODEV);
 682         }
 683 }
 684
 685 static void
 686 ccw_device_release(struct device *dev)
 687 {
 688         struct ccw_device *cdev;
 689
 690         cdev = to_ccwdev(dev);
 691         /* Release reference of parent subchannel. */
 692         put_device(cdev->dev.parent);
 693         kfree(cdev->private);
 694         kfree(cdev);
 695 }
 696
 697 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 698 {
 699         struct ccw_device *cdev;
 700
 701         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 702         if (cdev) {
 703                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 704                                         GFP_KERNEL | GFP_DMA);
 705                 if (cdev->private)
 706                         return cdev;
 707         }
 708         kfree(cdev);
 709         return ERR_PTR(-ENOMEM);
 710 }
 711
 712 static void ccw_device_todo(struct work_struct *work);
 713
 714 static int io_subchannel_initialize_dev(struct subchannel *sch,
 715                                         struct ccw_device *cdev)
 716 {
 717         struct ccw_device_private *priv = cdev->private;
 718         int ret;
 719
 720         priv->cdev = cdev;
 721         priv->int_class = IRQIO_CIO;
 722         priv->state = DEV_STATE_NOT_OPER;
 723         priv->dev_id.devno = sch->schib.pmcw.dev;
 724         priv->dev_id.ssid = sch->schid.ssid;
 725
 726         INIT_WORK(&priv->todo_work, ccw_device_todo);
 727         INIT_LIST_HEAD(&priv->cmb_list);
 728         init_waitqueue_head(&priv->wait_q);
 729         init_timer(&priv->timer);
 730
 731         atomic_set(&priv->onoff, 0);
 732         cdev->ccwlock = sch->lock;
 733         cdev->dev.parent = &sch->dev;
 734         cdev->dev.release = ccw_device_release;
 735         cdev->dev.groups = ccwdev_attr_groups;
 736         /* Do first half of device_register. */
 737         device_initialize(&cdev->dev);
 738         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 739                            cdev->private->dev_id.devno);
 740         if (ret)
 741                 goto out_put;
 742         if (!get_device(&sch->dev)) {
 743                 ret = -ENODEV;
 744                 goto out_put;
 745         }
 746         priv->flags.initialized = 1;
 747         spin_lock_irq(sch->lock);
 748         sch_set_cdev(sch, cdev);
 749         spin_unlock_irq(sch->lock);
 750         return 0;
 751
 752 out_put:
 753         /* Release reference from device_initialize(). */
 754         put_device(&cdev->dev);
 755         return ret;
 756 }
 757
 758 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 759 {
 760         struct ccw_device *cdev;
 761         int ret;
 762
 763         cdev = io_subchannel_allocate_dev(sch);
 764         if (!IS_ERR(cdev)) {
 765                 ret = io_subchannel_initialize_dev(sch, cdev);
 766                 if (ret)
 767                         cdev = ERR_PTR(ret);
 768         }
 769         return cdev;
 770 }
 771
 772 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 773
 774 static void sch_create_and_recog_new_device(struct subchannel *sch)
 775 {
 776         struct ccw_device *cdev;
 777
 778         /* Need to allocate a new ccw device. */
 779         cdev = io_subchannel_create_ccwdev(sch);
 780         if (IS_ERR(cdev)) {
 781                 /* OK, we did everything we could... */
 782                 css_sch_device_unregister(sch);
 783                 return;
 784         }
 785         /* Start recognition for the new ccw device. */
 786         io_subchannel_recog(cdev, sch);
 787 }
 788
 789 /*
 790  * Register recognized device.
 791  */
 792 static void io_subchannel_register(struct ccw_device *cdev)
 793 {
 794         struct subchannel *sch;
 795         int ret, adjust_init_count = 1;
 796         unsigned long flags;
 797
 798         sch = to_subchannel(cdev->dev.parent);
 799         /*
 800          * Check if subchannel is still registered. It may have become
 801          * unregistered if a machine check hit us after finishing
 802          * device recognition but before the register work could be
 803          * queued.
 804          */
 805         if (!device_is_registered(&sch->dev))
 806                 goto out_err;
 807         css_update_ssd_info(sch);
 808         /*
 809          * io_subchannel_register() will also be called after device
 810          * recognition has been done for a boxed device (which will already
 811          * be registered). We need to reprobe since we may now have sense id
 812          * information.
 813          */
 814         if (device_is_registered(&cdev->dev)) {
 815                 if (!cdev->drv) {
 816                         ret = device_reprobe(&cdev->dev);
 817                         if (ret)
 818                                 /* We can't do much here. */
 819                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 820                                               " %d for 0.%x.%04x\n", ret,
 821                                               cdev->private->dev_id.ssid,
 822                                               cdev->private->dev_id.devno);
 823                 }
 824                 adjust_init_count = 0;
 825                 goto out;
 826         }
 827         /*
 828          * Now we know this subchannel will stay, we can throw
 829          * our delayed uevent.
 830          */
 831         dev_set_uevent_suppress(&sch->dev, 0);
 832         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 833         /* make it known to the system */
 834         ret = ccw_device_add(cdev);
 835         if (ret) {
 836                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 837                               cdev->private->dev_id.ssid,
 838                               cdev->private->dev_id.devno, ret);
 839                 spin_lock_irqsave(sch->lock, flags);
 840                 sch_set_cdev(sch, NULL);
 841                 spin_unlock_irqrestore(sch->lock, flags);
 842                 /* Release initial device reference. */
 843                 put_device(&cdev->dev);
 844                 goto out_err;
 845         }
 846 out:
 847         cdev->private->flags.recog_done = 1;
 848         wake_up(&cdev->private->wait_q);
 849 out_err:
 850         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 851                 wake_up(&ccw_device_init_wq);
 852 }
 853
 854 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 855 {
 856         struct subchannel *sch;
 857
 858         /* Get subchannel reference for local processing. */
 859         if (!get_device(cdev->dev.parent))
 860                 return;
 861         sch = to_subchannel(cdev->dev.parent);
 862         css_sch_device_unregister(sch);
 863         /* Release subchannel reference for local processing. */
 864         put_device(&sch->dev);
 865 }
 866
 867 /*
 868  * subchannel recognition done. Called from the state machine.
 869  */
 870 void
 871 io_subchannel_recog_done(struct ccw_device *cdev)
 872 {
 873         if (css_init_done == 0) {
 874                 cdev->private->flags.recog_done = 1;
 875                 return;
 876         }
 877         switch (cdev->private->state) {
 878         case DEV_STATE_BOXED:
 879                 /* Device did not respond in time. */
 880         case DEV_STATE_NOT_OPER:
 881                 cdev->private->flags.recog_done = 1;
 882                 /* Remove device found not operational. */
 883                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 884                 if (atomic_dec_and_test(&ccw_device_init_count))
 885                         wake_up(&ccw_device_init_wq);
 886                 break;
 887         case DEV_STATE_OFFLINE:
 888                 /*
 889                  * We can't register the device in interrupt context so
 890                  * we schedule a work item.
 891                  */
 892                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 893                 break;
 894         }
 895 }
 896
 897 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 898 {
 899         /* Increase counter of devices currently in recognition. */
 900         atomic_inc(&ccw_device_init_count);
 901
 902         /* Start async. device sensing. */
 903         spin_lock_irq(sch->lock);
 904         ccw_device_recognition(cdev);
 905         spin_unlock_irq(sch->lock);
 906 }
 907
 908 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 909                                   struct subchannel *sch)
 910 {
 911         struct subchannel *old_sch;
 912         int rc, old_enabled = 0;
 913
 914         old_sch = to_subchannel(cdev->dev.parent);
 915         /* Obtain child reference for new parent. */
 916         if (!get_device(&sch->dev))
 917                 return -ENODEV;
 918
 919         if (!sch_is_pseudo_sch(old_sch)) {
 920                 spin_lock_irq(old_sch->lock);
 921                 old_enabled = old_sch->schib.pmcw.ena;
 922                 rc = 0;
 923                 if (old_enabled)
 924                         rc = cio_disable_subchannel(old_sch);
 925                 spin_unlock_irq(old_sch->lock);
 926                 if (rc == -EBUSY) {
 927                         /* Release child reference for new parent. */
 928                         put_device(&sch->dev);
 929                         return rc;
 930                 }
 931         }
 932
 933         mutex_lock(&sch->reg_mutex);
 934         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 935         mutex_unlock(&sch->reg_mutex);
 936         if (rc) {
 937                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 938                               cdev->private->dev_id.ssid,
 939                               cdev->private->dev_id.devno, sch->schid.ssid,
 940                               sch->schib.pmcw.dev, rc);
 941                 if (old_enabled) {
 942                         /* Try to reenable the old subchannel. */
 943                         spin_lock_irq(old_sch->lock);
 944                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 945                         spin_unlock_irq(old_sch->lock);
 946                 }
 947                 /* Release child reference for new parent. */
 948                 put_device(&sch->dev);
 949                 return rc;
 950         }
 951         /* Clean up old subchannel. */
 952         if (!sch_is_pseudo_sch(old_sch)) {
 953                 spin_lock_irq(old_sch->lock);
 954                 sch_set_cdev(old_sch, NULL);
 955                 spin_unlock_irq(old_sch->lock);
 956                 css_schedule_eval(old_sch->schid);
 957         }
 958         /* Release child reference for old parent. */
 959         put_device(&old_sch->dev);
 960         /* Initialize new subchannel. */
 961         spin_lock_irq(sch->lock);
 962         cdev->ccwlock = sch->lock;
 963         if (!sch_is_pseudo_sch(sch))
 964                 sch_set_cdev(sch, cdev);
 965         spin_unlock_irq(sch->lock);
 966         if (!sch_is_pseudo_sch(sch))
 967                 css_update_ssd_info(sch);
 968         return 0;
 969 }
 970
 971 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 972 {
 973         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 974         struct channel_subsystem *css = to_css(sch->dev.parent);
 975
 976         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 977 }
 978
 979 static void io_subchannel_irq(struct subchannel *sch)
 980 {
 981         struct ccw_device *cdev;
 982
 983         cdev = sch_get_cdev(sch);
 984
 985         CIO_TRACE_EVENT(6, "IRQ");
 986         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
 987         if (cdev)
 988                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
 989         else
 990                 inc_irq_stat(IRQIO_CIO);
 991 }
 992
 993 void io_subchannel_init_config(struct subchannel *sch)
 994 {
 995         memset(&sch->config, 0, sizeof(sch->config));
 996         sch->config.csense = 1;
 997 }
 998
 999 static void io_subchannel_init_fields(struct subchannel *sch)
1000 {
1001         if (cio_is_console(sch->schid))
1002                 sch->opm = 0xff;
1003         else
1004                 sch->opm = chp_get_sch_opm(sch);
1005         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1006         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1007
1008         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1009                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1010                       sch->schib.pmcw.dev, sch->schid.ssid,
1011                       sch->schid.sch_no, sch->schib.pmcw.pim,
1012                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1013
1014         io_subchannel_init_config(sch);
1015 }
1016
1017 /*
1018  * Note: We always return 0 so that we bind to the device even on error.
1019  * This is needed so that our remove function is called on unregister.
1020  */
1021 static int io_subchannel_probe(struct subchannel *sch)
1022 {
1023         struct io_subchannel_private *io_priv;
1024         struct ccw_device *cdev;
1025         int rc;
1026
1027         if (cio_is_console(sch->schid)) {
1028                 rc = sysfs_create_group(&sch->dev.kobj,
1029                                         &io_subchannel_attr_group);
1030                 if (rc)
1031                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1032                                       "attributes for subchannel "
1033                                       "0.%x.%04x (rc=%d)\n",
1034                                       sch->schid.ssid, sch->schid.sch_no, rc);
1035                 /*
1036                  * The console subchannel already has an associated ccw_device.
1037                  * Throw the delayed uevent for the subchannel, register
1038                  * the ccw_device and exit.
1039                  */
1040                 dev_set_uevent_suppress(&sch->dev, 0);
1041                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1042                 cdev = sch_get_cdev(sch);
1043                 rc = ccw_device_add(cdev);
1044                 if (rc) {
1045                         /* Release online reference. */
1046                         put_device(&cdev->dev);
1047                         goto out_schedule;
1048                 }
1049                 if (atomic_dec_and_test(&ccw_device_init_count))
1050                         wake_up(&ccw_device_init_wq);
1051                 return 0;
1052         }
1053         io_subchannel_init_fields(sch);
1054         rc = cio_commit_config(sch);
1055         if (rc)
1056                 goto out_schedule;
1057         rc = sysfs_create_group(&sch->dev.kobj,
1058                                 &io_subchannel_attr_group);
1059         if (rc)
1060                 goto out_schedule;
1061         /* Allocate I/O subchannel private data. */
1062         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1063         if (!io_priv)
1064                 goto out_schedule;
1065
1066         set_io_private(sch, io_priv);
1067         css_schedule_eval(sch->schid);
1068         return 0;
1069
1070 out_schedule:
1071         spin_lock_irq(sch->lock);
1072         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1073         spin_unlock_irq(sch->lock);
1074         return 0;
1075 }
1076
1077 static int
1078 io_subchannel_remove (struct subchannel *sch)
1079 {
1080         struct io_subchannel_private *io_priv = to_io_private(sch);
1081         struct ccw_device *cdev;
1082
1083         cdev = sch_get_cdev(sch);
1084         if (!cdev)
1085                 goto out_free;
1086         io_subchannel_quiesce(sch);
1087         /* Set ccw device to not operational and drop reference. */
1088         spin_lock_irq(cdev->ccwlock);
1089         sch_set_cdev(sch, NULL);
1090         set_io_private(sch, NULL);
1091         cdev->private->state = DEV_STATE_NOT_OPER;
1092         spin_unlock_irq(cdev->ccwlock);
1093         ccw_device_unregister(cdev);
1094 out_free:
1095         kfree(io_priv);
1096         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1097         return 0;
1098 }
1099
1100 static void io_subchannel_verify(struct subchannel *sch)
1101 {
1102         struct ccw_device *cdev;
1103
1104         cdev = sch_get_cdev(sch);
1105         if (cdev)
1106                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1107 }
1108
1109 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1110 {
1111         struct ccw_device *cdev;
1112
1113         cdev = sch_get_cdev(sch);
1114         if (!cdev)
1115                 return;
1116         if (cio_update_schib(sch))
1117                 goto err;
1118         /* Check for I/O on path. */
1119         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1120                 goto out;
1121         if (cdev->private->state == DEV_STATE_ONLINE) {
1122                 ccw_device_kill_io(cdev);
1123                 goto out;
1124         }
1125         if (cio_clear(sch))
1126                 goto err;
1127 out:
1128         /* Trigger path verification. */
1129         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1130         return;
1131
1132 err:
1133         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1134 }
1135
1136 static int io_subchannel_chp_event(struct subchannel *sch,
1137                                    struct chp_link *link, int event)
1138 {
1139         struct ccw_device *cdev = sch_get_cdev(sch);
1140         int mask;
1141
1142         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1143         if (!mask)
1144                 return 0;
1145         switch (event) {
1146         case CHP_VARY_OFF:
1147                 sch->opm &= ~mask;
1148                 sch->lpm &= ~mask;
1149                 if (cdev)
1150                         cdev->private->path_gone_mask |= mask;
1151                 io_subchannel_terminate_path(sch, mask);
1152                 break;
1153         case CHP_VARY_ON:
1154                 sch->opm |= mask;
1155                 sch->lpm |= mask;
1156                 if (cdev)
1157                         cdev->private->path_new_mask |= mask;
1158                 io_subchannel_verify(sch);
1159                 break;
1160         case CHP_OFFLINE:
1161                 if (cio_update_schib(sch))
1162                         return -ENODEV;
1163                 if (cdev)
1164                         cdev->private->path_gone_mask |= mask;
1165                 io_subchannel_terminate_path(sch, mask);
1166                 break;
1167         case CHP_ONLINE:
1168                 if (cio_update_schib(sch))
1169                         return -ENODEV;
1170                 sch->lpm |= mask & sch->opm;
1171                 if (cdev)
1172                         cdev->private->path_new_mask |= mask;
1173                 io_subchannel_verify(sch);
1174                 break;
1175         }
1176         return 0;
1177 }
1178
1179 static void io_subchannel_quiesce(struct subchannel *sch)
1180 {
1181         struct ccw_device *cdev;
1182         int ret;
1183
1184         spin_lock_irq(sch->lock);
1185         cdev = sch_get_cdev(sch);
1186         if (cio_is_console(sch->schid))
1187                 goto out_unlock;
1188         if (!sch->schib.pmcw.ena)
1189                 goto out_unlock;
1190         ret = cio_disable_subchannel(sch);
1191         if (ret != -EBUSY)
1192                 goto out_unlock;
1193         if (cdev->handler)
1194                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1195         while (ret == -EBUSY) {
1196                 cdev->private->state = DEV_STATE_QUIESCE;
1197                 cdev->private->iretry = 255;
1198                 ret = ccw_device_cancel_halt_clear(cdev);
1199                 if (ret == -EBUSY) {
1200                         ccw_device_set_timeout(cdev, HZ/10);
1201                         spin_unlock_irq(sch->lock);
1202                         wait_event(cdev->private->wait_q,
1203                                    cdev->private->state != DEV_STATE_QUIESCE);
1204                         spin_lock_irq(sch->lock);
1205                 }
1206                 ret = cio_disable_subchannel(sch);
1207         }
1208 out_unlock:
1209         spin_unlock_irq(sch->lock);
1210 }
1211
1212 static void io_subchannel_shutdown(struct subchannel *sch)
1213 {
1214         io_subchannel_quiesce(sch);
1215 }
1216
1217 static int device_is_disconnected(struct ccw_device *cdev)
1218 {
1219         if (!cdev)
1220                 return 0;
1221         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1222                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1223 }
1224
1225 static int recovery_check(struct device *dev, void *data)
1226 {
1227         struct ccw_device *cdev = to_ccwdev(dev);
1228         struct subchannel *sch;
1229         int *redo = data;
1230
1231         spin_lock_irq(cdev->ccwlock);
1232         switch (cdev->private->state) {
1233         case DEV_STATE_ONLINE:
1234                 sch = to_subchannel(cdev->dev.parent);
1235                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1236                         break;
1237                 /* fall through */
1238         case DEV_STATE_DISCONNECTED:
1239                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1240                               cdev->private->dev_id.ssid,
1241                               cdev->private->dev_id.devno);
1242                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1243                 *redo = 1;
1244                 break;
1245         case DEV_STATE_DISCONNECTED_SENSE_ID:
1246                 *redo = 1;
1247                 break;
1248         }
1249         spin_unlock_irq(cdev->ccwlock);
1250
1251         return 0;
1252 }
1253
1254 static void recovery_work_func(struct work_struct *unused)
1255 {
1256         int redo = 0;
1257
1258         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1259         if (redo) {
1260                 spin_lock_irq(&recovery_lock);
1261                 if (!timer_pending(&recovery_timer)) {
1262                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1263                                 recovery_phase++;
1264                         mod_timer(&recovery_timer, jiffies +
1265                                   recovery_delay[recovery_phase] * HZ);
1266                 }
1267                 spin_unlock_irq(&recovery_lock);
1268         } else
1269                 CIO_MSG_EVENT(3, "recovery: end\n");
1270 }
1271
1272 static DECLARE_WORK(recovery_work, recovery_work_func);
1273
1274 static void recovery_func(unsigned long data)
1275 {
1276         /*
1277          * We can't do our recovery in softirq context and it's not
1278          * performance critical, so we schedule it.
1279          */
1280         schedule_work(&recovery_work);
1281 }
1282
1283 void ccw_device_schedule_recovery(void)
1284 {
1285         unsigned long flags;
1286
1287         CIO_MSG_EVENT(3, "recovery: schedule\n");
1288         spin_lock_irqsave(&recovery_lock, flags);
1289         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1290                 recovery_phase = 0;
1291                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1292         }
1293         spin_unlock_irqrestore(&recovery_lock, flags);
1294 }
1295
1296 static int purge_fn(struct device *dev, void *data)
1297 {
1298         struct ccw_device *cdev = to_ccwdev(dev);
1299         struct ccw_dev_id *id = &cdev->private->dev_id;
1300
1301         spin_lock_irq(cdev->ccwlock);
1302         if (is_blacklisted(id->ssid, id->devno) &&
1303             (cdev->private->state == DEV_STATE_OFFLINE) &&
1304             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1305                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1306                               id->devno);
1307                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1308                 atomic_set(&cdev->private->onoff, 0);
1309         }
1310         spin_unlock_irq(cdev->ccwlock);
1311         /* Abort loop in case of pending signal. */
1312         if (signal_pending(current))
1313                 return -EINTR;
1314
1315         return 0;
1316 }
1317
1318 /**
1319  * ccw_purge_blacklisted - purge unused, blacklisted devices
1320  *
1321  * Unregister all ccw devices that are offline and on the blacklist.
1322  */
1323 int ccw_purge_blacklisted(void)
1324 {
1325         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1326         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1327         return 0;
1328 }
1329
1330 void ccw_device_set_disconnected(struct ccw_device *cdev)
1331 {
1332         if (!cdev)
1333                 return;
1334         ccw_device_set_timeout(cdev, 0);
1335         cdev->private->flags.fake_irb = 0;
1336         cdev->private->state = DEV_STATE_DISCONNECTED;
1337         if (cdev->online)
1338                 ccw_device_schedule_recovery();
1339 }
1340
1341 void ccw_device_set_notoper(struct ccw_device *cdev)
1342 {
1343         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1344
1345         CIO_TRACE_EVENT(2, "notoper");
1346         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1347         ccw_device_set_timeout(cdev, 0);
1348         cio_disable_subchannel(sch);
1349         cdev->private->state = DEV_STATE_NOT_OPER;
1350 }
1351
1352 enum io_sch_action {
1353         IO_SCH_UNREG,
1354         IO_SCH_ORPH_UNREG,
1355         IO_SCH_ATTACH,
1356         IO_SCH_UNREG_ATTACH,
1357         IO_SCH_ORPH_ATTACH,
1358         IO_SCH_REPROBE,
1359         IO_SCH_VERIFY,
1360         IO_SCH_DISC,
1361         IO_SCH_NOP,
1362 };
1363
1364 static enum io_sch_action sch_get_action(struct subchannel *sch)
1365 {
1366         struct ccw_device *cdev;
1367
1368         cdev = sch_get_cdev(sch);
1369         if (cio_update_schib(sch)) {
1370                 /* Not operational. */
1371                 if (!cdev)
1372                         return IO_SCH_UNREG;
1373                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1374                         return IO_SCH_UNREG;
1375                 return IO_SCH_ORPH_UNREG;
1376         }
1377         /* Operational. */
1378         if (!cdev)
1379                 return IO_SCH_ATTACH;
1380         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1381                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1382                         return IO_SCH_UNREG_ATTACH;
1383                 return IO_SCH_ORPH_ATTACH;
1384         }
1385         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1386                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1387                         return IO_SCH_UNREG;
1388                 return IO_SCH_DISC;
1389         }
1390         if (device_is_disconnected(cdev))
1391                 return IO_SCH_REPROBE;
1392         if (cdev->online && !cdev->private->flags.resuming)
1393                 return IO_SCH_VERIFY;
1394         if (cdev->private->state == DEV_STATE_NOT_OPER)
1395                 return IO_SCH_UNREG_ATTACH;
1396         return IO_SCH_NOP;
1397 }
1398
1399 /**
1400  * io_subchannel_sch_event - process subchannel event
1401  * @sch: subchannel
1402  * @process: non-zero if function is called in process context
1403  *
1404  * An unspecified event occurred for this subchannel. Adjust data according
1405  * to the current operational state of the subchannel and device. Return
1406  * zero when the event has been handled sufficiently or -EAGAIN when this
1407  * function should be called again in process context.
1408  */
1409 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1410 {
1411         unsigned long flags;
1412         struct ccw_device *cdev;
1413         struct ccw_dev_id dev_id;
1414         enum io_sch_action action;
1415         int rc = -EAGAIN;
1416
1417         spin_lock_irqsave(sch->lock, flags);
1418         if (!device_is_registered(&sch->dev))
1419                 goto out_unlock;
1420         if (work_pending(&sch->todo_work))
1421                 goto out_unlock;
1422         cdev = sch_get_cdev(sch);
1423         if (cdev && work_pending(&cdev->private->todo_work))
1424                 goto out_unlock;
1425         action = sch_get_action(sch);
1426         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1427                       sch->schid.ssid, sch->schid.sch_no, process,
1428                       action);
1429         /* Perform immediate actions while holding the lock. */
1430         switch (action) {
1431         case IO_SCH_REPROBE:
1432                 /* Trigger device recognition. */
1433                 ccw_device_trigger_reprobe(cdev);
1434                 rc = 0;
1435                 goto out_unlock;
1436         case IO_SCH_VERIFY:
1437                 /* Trigger path verification. */
1438                 io_subchannel_verify(sch);
1439                 rc = 0;
1440                 goto out_unlock;
1441         case IO_SCH_DISC:
1442                 ccw_device_set_disconnected(cdev);
1443                 rc = 0;
1444                 goto out_unlock;
1445         case IO_SCH_ORPH_UNREG:
1446         case IO_SCH_ORPH_ATTACH:
1447                 ccw_device_set_disconnected(cdev);
1448                 break;
1449         case IO_SCH_UNREG_ATTACH:
1450         case IO_SCH_UNREG:
1451                 if (!cdev)
1452                         break;
1453                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1454                         /*
1455                          * Note: delayed work triggered by this event
1456                          * and repeated calls to sch_event are synchronized
1457                          * by the above check for work_pending(cdev).
1458                          */
1459                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1460                 } else
1461                         ccw_device_set_notoper(cdev);
1462                 break;
1463         case IO_SCH_NOP:
1464                 rc = 0;
1465                 goto out_unlock;
1466         default:
1467                 break;
1468         }
1469         spin_unlock_irqrestore(sch->lock, flags);
1470         /* All other actions require process context. */
1471         if (!process)
1472                 goto out;
1473         /* Handle attached ccw device. */
1474         switch (action) {
1475         case IO_SCH_ORPH_UNREG:
1476         case IO_SCH_ORPH_ATTACH:
1477                 /* Move ccw device to orphanage. */
1478                 rc = ccw_device_move_to_orph(cdev);
1479                 if (rc)
1480                         goto out;
1481                 break;
1482         case IO_SCH_UNREG_ATTACH:
1483                 spin_lock_irqsave(sch->lock, flags);
1484                 if (cdev->private->flags.resuming) {
1485                         /* Device will be handled later. */
1486                         rc = 0;
1487                         goto out_unlock;
1488                 }
1489                 sch_set_cdev(sch, NULL);
1490                 spin_unlock_irqrestore(sch->lock, flags);
1491                 /* Unregister ccw device. */
1492                 ccw_device_unregister(cdev);
1493                 break;
1494         default:
1495                 break;
1496         }
1497         /* Handle subchannel. */
1498         switch (action) {
1499         case IO_SCH_ORPH_UNREG:
1500         case IO_SCH_UNREG:
1501                 if (!cdev || !cdev->private->flags.resuming)
1502                         css_sch_device_unregister(sch);
1503                 break;
1504         case IO_SCH_ORPH_ATTACH:
1505         case IO_SCH_UNREG_ATTACH:
1506         case IO_SCH_ATTACH:
1507                 dev_id.ssid = sch->schid.ssid;
1508                 dev_id.devno = sch->schib.pmcw.dev;
1509                 cdev = get_ccwdev_by_dev_id(&dev_id);
1510                 if (!cdev) {
1511                         sch_create_and_recog_new_device(sch);
1512                         break;
1513                 }
1514                 rc = ccw_device_move_to_sch(cdev, sch);
1515                 if (rc) {
1516                         /* Release reference from get_ccwdev_by_dev_id() */
1517                         put_device(&cdev->dev);
1518                         goto out;
1519                 }
1520                 spin_lock_irqsave(sch->lock, flags);
1521                 ccw_device_trigger_reprobe(cdev);
1522                 spin_unlock_irqrestore(sch->lock, flags);
1523                 /* Release reference from get_ccwdev_by_dev_id() */
1524                 put_device(&cdev->dev);
1525                 break;
1526         default:
1527                 break;
1528         }
1529         return 0;
1530
1531 out_unlock:
1532         spin_unlock_irqrestore(sch->lock, flags);
1533 out:
1534         return rc;
1535 }
1536
1537 static void ccw_device_set_int_class(struct ccw_device *cdev)
1538 {
1539         struct ccw_driver *cdrv = cdev->drv;
1540
1541         /* Note: we interpret class 0 in this context as an uninitialized
1542          * field since it translates to a non-I/O interrupt class. */
1543         if (cdrv->int_class != 0)
1544                 cdev->private->int_class = cdrv->int_class;
1545         else
1546                 cdev->private->int_class = IRQIO_CIO;
1547 }
1548
1549 #ifdef CONFIG_CCW_CONSOLE
1550 int __init ccw_device_enable_console(struct ccw_device *cdev)
1551 {
1552         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1553         int rc;
1554
1555         if (!cdev->drv || !cdev->handler)
1556                 return -EINVAL;
1557
1558         io_subchannel_init_fields(sch);
1559         rc = cio_commit_config(sch);
1560         if (rc)
1561                 return rc;
1562         sch->driver = &io_subchannel_driver;
1563         io_subchannel_recog(cdev, sch);
1564         /* Now wait for the async. recognition to come to an end. */
1565         spin_lock_irq(cdev->ccwlock);
1566         while (!dev_fsm_final_state(cdev))
1567                 ccw_device_wait_idle(cdev);
1568
1569         /* Hold on to an extra reference while device is online. */
1570         get_device(&cdev->dev);
1571         rc = ccw_device_online(cdev);
1572         if (rc)
1573                 goto out_unlock;
1574
1575         while (!dev_fsm_final_state(cdev))
1576                 ccw_device_wait_idle(cdev);
1577
1578         if (cdev->private->state == DEV_STATE_ONLINE)
1579                 cdev->online = 1;
1580         else
1581                 rc = -EIO;
1582 out_unlock:
1583         spin_unlock_irq(cdev->ccwlock);
1584         if (rc) /* Give up online reference since onlining failed. */
1585                 put_device(&cdev->dev);
1586         return rc;
1587 }
1588
1589 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1590 {
1591         struct io_subchannel_private *io_priv;
1592         struct ccw_device *cdev;
1593         struct subchannel *sch;
1594
1595         sch = cio_probe_console();
1596         if (IS_ERR(sch))
1597                 return ERR_CAST(sch);
1598
1599         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1600         if (!io_priv) {
1601                 put_device(&sch->dev);
1602                 return ERR_PTR(-ENOMEM);
1603         }
1604         set_io_private(sch, io_priv);
1605         cdev = io_subchannel_create_ccwdev(sch);
1606         if (IS_ERR(cdev)) {
1607                 put_device(&sch->dev);
1608                 kfree(io_priv);
1609                 return cdev;
1610         }
1611         cdev->drv = drv;
1612         ccw_device_set_int_class(cdev);
1613         return cdev;
1614 }
1615
1616 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1617 {
1618         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1619         struct io_subchannel_private *io_priv = to_io_private(sch);
1620
1621         set_io_private(sch, NULL);
1622         put_device(&sch->dev);
1623         put_device(&cdev->dev);
1624         kfree(io_priv);
1625 }
1626
1627 /**
1628  * ccw_device_wait_idle() - busy wait for device to become idle
1629  * @cdev: ccw device
1630  *
1631  * Poll until activity control is zero, that is, no function or data
1632  * transfer is pending/active.
1633  * Called with device lock being held.
1634  */
1635 void ccw_device_wait_idle(struct ccw_device *cdev)
1636 {
1637         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1638
1639         while (1) {
1640                 cio_tsch(sch);
1641                 if (sch->schib.scsw.cmd.actl == 0)
1642                         break;
1643                 udelay_simple(100);
1644         }
1645 }
1646
1647 static int ccw_device_pm_restore(struct device *dev);
1648
1649 int ccw_device_force_console(struct ccw_device *cdev)
1650 {
1651         return ccw_device_pm_restore(&cdev->dev);
1652 }
1653 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1654 #endif
1655
1656 /*
1657  * get ccw_device matching the busid, but only if owned by cdrv
1658  */
1659 static int
1660 __ccwdev_check_busid(struct device *dev, void *id)
1661 {
1662         char *bus_id;
1663
1664         bus_id = id;
1665
1666         return (strcmp(bus_id, dev_name(dev)) == 0);
1667 }
1668
1669
1670 /**
1671  * get_ccwdev_by_busid() - obtain device from a bus id
1672  * @cdrv: driver the device is owned by
1673  * @bus_id: bus id of the device to be searched
1674  *
1675  * This function searches all devices owned by @cdrv for a device with a bus
1676  * id matching @bus_id.
1677  * Returns:
1678  *  If a match is found, its reference count of the found device is increased
1679  *  and it is returned; else %NULL is returned.
1680  */
1681 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1682                                        const char *bus_id)
1683 {
1684         struct device *dev;
1685
1686         dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
1687                                  __ccwdev_check_busid);
1688
1689         return dev ? to_ccwdev(dev) : NULL;
1690 }
1691
1692 /************************** device driver handling ************************/
1693
1694 /* This is the implementation of the ccw_driver class. The probe, remove
1695  * and release methods are initially very similar to the device_driver
1696  * implementations, with the difference that they have ccw_device
1697  * arguments.
1698  *
1699  * A ccw driver also contains the information that is needed for
1700  * device matching.
1701  */
1702 static int
1703 ccw_device_probe (struct device *dev)
1704 {
1705         struct ccw_device *cdev = to_ccwdev(dev);
1706         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1707         int ret;
1708
1709         cdev->drv = cdrv; /* to let the driver call _set_online */
1710         ccw_device_set_int_class(cdev);
1711         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1712         if (ret) {
1713                 cdev->drv = NULL;
1714                 cdev->private->int_class = IRQIO_CIO;
1715                 return ret;
1716         }
1717
1718         return 0;
1719 }
1720
1721 static int ccw_device_remove(struct device *dev)
1722 {
1723         struct ccw_device *cdev = to_ccwdev(dev);
1724         struct ccw_driver *cdrv = cdev->drv;
1725         int ret;
1726
1727         if (cdrv->remove)
1728                 cdrv->remove(cdev);
1729
1730         spin_lock_irq(cdev->ccwlock);
1731         if (cdev->online) {
1732                 cdev->online = 0;
1733                 ret = ccw_device_offline(cdev);
1734                 spin_unlock_irq(cdev->ccwlock);
1735                 if (ret == 0)
1736                         wait_event(cdev->private->wait_q,
1737                                    dev_fsm_final_state(cdev));
1738                 else
1739                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1740                                       "device 0.%x.%04x\n",
1741                                       ret, cdev->private->dev_id.ssid,
1742                                       cdev->private->dev_id.devno);
1743                 /* Give up reference obtained in ccw_device_set_online(). */
1744                 put_device(&cdev->dev);
1745                 spin_lock_irq(cdev->ccwlock);
1746         }
1747         ccw_device_set_timeout(cdev, 0);
1748         cdev->drv = NULL;
1749         cdev->private->int_class = IRQIO_CIO;
1750         spin_unlock_irq(cdev->ccwlock);
1751         __disable_cmf(cdev);
1752
1753         return 0;
1754 }
1755
1756 static void ccw_device_shutdown(struct device *dev)
1757 {
1758         struct ccw_device *cdev;
1759
1760         cdev = to_ccwdev(dev);
1761         if (cdev->drv && cdev->drv->shutdown)
1762                 cdev->drv->shutdown(cdev);
1763         __disable_cmf(cdev);
1764 }
1765
1766 static int ccw_device_pm_prepare(struct device *dev)
1767 {
1768         struct ccw_device *cdev = to_ccwdev(dev);
1769
1770         if (work_pending(&cdev->private->todo_work))
1771                 return -EAGAIN;
1772         /* Fail while device is being set online/offline. */
1773         if (atomic_read(&cdev->private->onoff))
1774                 return -EAGAIN;
1775
1776         if (cdev->online && cdev->drv && cdev->drv->prepare)
1777                 return cdev->drv->prepare(cdev);
1778
1779         return 0;
1780 }
1781
1782 static void ccw_device_pm_complete(struct device *dev)
1783 {
1784         struct ccw_device *cdev = to_ccwdev(dev);
1785
1786         if (cdev->online && cdev->drv && cdev->drv->complete)
1787                 cdev->drv->complete(cdev);
1788 }
1789
1790 static int ccw_device_pm_freeze(struct device *dev)
1791 {
1792         struct ccw_device *cdev = to_ccwdev(dev);
1793         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1794         int ret, cm_enabled;
1795
1796         /* Fail suspend while device is in transistional state. */
1797         if (!dev_fsm_final_state(cdev))
1798                 return -EAGAIN;
1799         if (!cdev->online)
1800                 return 0;
1801         if (cdev->drv && cdev->drv->freeze) {
1802                 ret = cdev->drv->freeze(cdev);
1803                 if (ret)
1804                         return ret;
1805         }
1806
1807         spin_lock_irq(sch->lock);
1808         cm_enabled = cdev->private->cmb != NULL;
1809         spin_unlock_irq(sch->lock);
1810         if (cm_enabled) {
1811                 /* Don't have the css write on memory. */
1812                 ret = ccw_set_cmf(cdev, 0);
1813                 if (ret)
1814                         return ret;
1815         }
1816         /* From here on, disallow device driver I/O. */
1817         spin_lock_irq(sch->lock);
1818         ret = cio_disable_subchannel(sch);
1819         spin_unlock_irq(sch->lock);
1820
1821         return ret;
1822 }
1823
1824 static int ccw_device_pm_thaw(struct device *dev)
1825 {
1826         struct ccw_device *cdev = to_ccwdev(dev);
1827         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1828         int ret, cm_enabled;
1829
1830         if (!cdev->online)
1831                 return 0;
1832
1833         spin_lock_irq(sch->lock);
1834         /* Allow device driver I/O again. */
1835         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1836         cm_enabled = cdev->private->cmb != NULL;
1837         spin_unlock_irq(sch->lock);
1838         if (ret)
1839                 return ret;
1840
1841         if (cm_enabled) {
1842                 ret = ccw_set_cmf(cdev, 1);
1843                 if (ret)
1844                         return ret;
1845         }
1846
1847         if (cdev->drv && cdev->drv->thaw)
1848                 ret = cdev->drv->thaw(cdev);
1849
1850         return ret;
1851 }
1852
1853 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1854 {
1855         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1856
1857         spin_lock_irq(sch->lock);
1858         if (cio_is_console(sch->schid)) {
1859                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1860                 goto out_unlock;
1861         }
1862         /*
1863          * While we were sleeping, devices may have gone or become
1864          * available again. Kick re-detection.
1865          */
1866         cdev->private->flags.resuming = 1;
1867         cdev->private->path_new_mask = LPM_ANYPATH;
1868         css_sched_sch_todo(sch, SCH_TODO_EVAL);
1869         spin_unlock_irq(sch->lock);
1870         css_wait_for_slow_path();
1871
1872         /* cdev may have been moved to a different subchannel. */
1873         sch = to_subchannel(cdev->dev.parent);
1874         spin_lock_irq(sch->lock);
1875         if (cdev->private->state != DEV_STATE_ONLINE &&
1876             cdev->private->state != DEV_STATE_OFFLINE)
1877                 goto out_unlock;
1878
1879         ccw_device_recognition(cdev);
1880         spin_unlock_irq(sch->lock);
1881         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1882                    cdev->private->state == DEV_STATE_DISCONNECTED);
1883         spin_lock_irq(sch->lock);
1884
1885 out_unlock:
1886         cdev->private->flags.resuming = 0;
1887         spin_unlock_irq(sch->lock);
1888 }
1889
1890 static int resume_handle_boxed(struct ccw_device *cdev)
1891 {
1892         cdev->private->state = DEV_STATE_BOXED;
1893         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1894                 return 0;
1895         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1896         return -ENODEV;
1897 }
1898
1899 static int resume_handle_disc(struct ccw_device *cdev)
1900 {
1901         cdev->private->state = DEV_STATE_DISCONNECTED;
1902         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1903                 return 0;
1904         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1905         return -ENODEV;
1906 }
1907
1908 static int ccw_device_pm_restore(struct device *dev)
1909 {
1910         struct ccw_device *cdev = to_ccwdev(dev);
1911         struct subchannel *sch;
1912         int ret = 0;
1913
1914         __ccw_device_pm_restore(cdev);
1915         sch = to_subchannel(cdev->dev.parent);
1916         spin_lock_irq(sch->lock);
1917         if (cio_is_console(sch->schid))
1918                 goto out_restore;
1919
1920         /* check recognition results */
1921         switch (cdev->private->state) {
1922         case DEV_STATE_OFFLINE:
1923         case DEV_STATE_ONLINE:
1924                 cdev->private->flags.donotify = 0;
1925                 break;
1926         case DEV_STATE_BOXED:
1927                 ret = resume_handle_boxed(cdev);
1928                 if (ret)
1929                         goto out_unlock;
1930                 goto out_restore;
1931         default:
1932                 ret = resume_handle_disc(cdev);
1933                 if (ret)
1934                         goto out_unlock;
1935                 goto out_restore;
1936         }
1937         /* check if the device type has changed */
1938         if (!ccw_device_test_sense_data(cdev)) {
1939                 ccw_device_update_sense_data(cdev);
1940                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1941                 ret = -ENODEV;
1942                 goto out_unlock;
1943         }
1944         if (!cdev->online)
1945                 goto out_unlock;
1946
1947         if (ccw_device_online(cdev)) {
1948                 ret = resume_handle_disc(cdev);
1949                 if (ret)
1950                         goto out_unlock;
1951                 goto out_restore;
1952         }
1953         spin_unlock_irq(sch->lock);
1954         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1955         spin_lock_irq(sch->lock);
1956
1957         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1958                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1959                 ret = -ENODEV;
1960                 goto out_unlock;
1961         }
1962
1963         /* reenable cmf, if needed */
1964         if (cdev->private->cmb) {
1965                 spin_unlock_irq(sch->lock);
1966                 ret = ccw_set_cmf(cdev, 1);
1967                 spin_lock_irq(sch->lock);
1968                 if (ret) {
1969                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1970                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1971                                       cdev->private->dev_id.devno, ret);
1972                         ret = 0;
1973                 }
1974         }
1975
1976 out_restore:
1977         spin_unlock_irq(sch->lock);
1978         if (cdev->online && cdev->drv && cdev->drv->restore)
1979                 ret = cdev->drv->restore(cdev);
1980         return ret;
1981
1982 out_unlock:
1983         spin_unlock_irq(sch->lock);
1984         return ret;
1985 }
1986
1987 static const struct dev_pm_ops ccw_pm_ops = {
1988         .prepare = ccw_device_pm_prepare,
1989         .complete = ccw_device_pm_complete,
1990         .freeze = ccw_device_pm_freeze,
1991         .thaw = ccw_device_pm_thaw,
1992         .restore = ccw_device_pm_restore,
1993 };
1994
1995 static struct bus_type ccw_bus_type = {
1996         .name   = "ccw",
1997         .match  = ccw_bus_match,
1998         .uevent = ccw_uevent,
1999         .probe  = ccw_device_probe,
2000         .remove = ccw_device_remove,
2001         .shutdown = ccw_device_shutdown,
2002         .pm = &ccw_pm_ops,
2003 };
2004
2005 /**
2006  * ccw_driver_register() - register a ccw driver
2007  * @cdriver: driver to be registered
2008  *
2009  * This function is mainly a wrapper around driver_register().
2010  * Returns:
2011  *   %0 on success and a negative error value on failure.
2012  */
2013 int ccw_driver_register(struct ccw_driver *cdriver)
2014 {
2015         struct device_driver *drv = &cdriver->driver;
2016
2017         drv->bus = &ccw_bus_type;
2018
2019         return driver_register(drv);
2020 }
2021
2022 /**
2023  * ccw_driver_unregister() - deregister a ccw driver
2024  * @cdriver: driver to be deregistered
2025  *
2026  * This function is mainly a wrapper around driver_unregister().
2027  */
2028 void ccw_driver_unregister(struct ccw_driver *cdriver)
2029 {
2030         driver_unregister(&cdriver->driver);
2031 }
2032
2033 static void ccw_device_todo(struct work_struct *work)
2034 {
2035         struct ccw_device_private *priv;
2036         struct ccw_device *cdev;
2037         struct subchannel *sch;
2038         enum cdev_todo todo;
2039
2040         priv = container_of(work, struct ccw_device_private, todo_work);
2041         cdev = priv->cdev;
2042         sch = to_subchannel(cdev->dev.parent);
2043         /* Find out todo. */
2044         spin_lock_irq(cdev->ccwlock);
2045         todo = priv->todo;
2046         priv->todo = CDEV_TODO_NOTHING;
2047         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2048                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2049         spin_unlock_irq(cdev->ccwlock);
2050         /* Perform todo. */
2051         switch (todo) {
2052         case CDEV_TODO_ENABLE_CMF:
2053                 cmf_reenable(cdev);
2054                 break;
2055         case CDEV_TODO_REBIND:
2056                 ccw_device_do_unbind_bind(cdev);
2057                 break;
2058         case CDEV_TODO_REGISTER:
2059                 io_subchannel_register(cdev);
2060                 break;
2061         case CDEV_TODO_UNREG_EVAL:
2062                 if (!sch_is_pseudo_sch(sch))
2063                         css_schedule_eval(sch->schid);
2064                 /* fall-through */
2065         case CDEV_TODO_UNREG:
2066                 if (sch_is_pseudo_sch(sch))
2067                         ccw_device_unregister(cdev);
2068                 else
2069                         ccw_device_call_sch_unregister(cdev);
2070                 break;
2071         default:
2072                 break;
2073         }
2074         /* Release workqueue ref. */
2075         put_device(&cdev->dev);
2076 }
2077
2078 /**
2079  * ccw_device_sched_todo - schedule ccw device operation
2080  * @cdev: ccw device
2081  * @todo: todo
2082  *
2083  * Schedule the operation identified by @todo to be performed on the slow path
2084  * workqueue. Do nothing if another operation with higher priority is already
2085  * scheduled. Needs to be called with ccwdev lock held.
2086  */
2087 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2088 {
2089         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2090                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2091                       todo);
2092         if (cdev->private->todo >= todo)
2093                 return;
2094         cdev->private->todo = todo;
2095         /* Get workqueue ref. */
2096         if (!get_device(&cdev->dev))
2097                 return;
2098         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2099                 /* Already queued, release workqueue ref. */
2100                 put_device(&cdev->dev);
2101         }
2102 }
2103
2104 /**
2105  * ccw_device_siosl() - initiate logging
2106  * @cdev: ccw device
2107  *
2108  * This function is used to invoke model-dependent logging within the channel
2109  * subsystem.
2110  */
2111 int ccw_device_siosl(struct ccw_device *cdev)
2112 {
2113         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2114
2115         return chsc_siosl(sch->schid);
2116 }
2117 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2118
2119 EXPORT_SYMBOL(ccw_device_set_online);
2120 EXPORT_SYMBOL(ccw_device_set_offline);
2121 EXPORT_SYMBOL(ccw_driver_register);
2122 EXPORT_SYMBOL(ccw_driver_unregister);
2123 EXPORT_SYMBOL(get_ccwdev_by_busid);