drivers/s390/cio/device.c

   1 // SPDX-License-Identifier: GPL-1.0+
   2 /*
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002, 2008
   6  *    Author(s): Arnd Bergmann ([email protected])
   7  *               Cornelia Huck ([email protected])
   8  *               Martin Schwidefsky ([email protected])
   9  */
  10
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/export.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/delay.h>
  24 #include <linux/timer.h>
  25 #include <linux/kernel_stat.h>
  26 #include <linux/sched/signal.h>
  27 #include <linux/dma-mapping.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 const 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, const struct device_driver * drv)
  62 {
  63         struct ccw_device *cdev = to_ccwdev(dev);
  64         const 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                          const 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(const struct device *dev, struct kobj_uevent_env *env)
 105 {
 106         const struct ccw_device *cdev = to_ccwdev(dev);
 107         const 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 void 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(struct timer_list *unused);
 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_settle(void)
 153 {
 154         int ret;
 155
 156         ret = wait_event_interruptible(ccw_device_init_wq,
 157                                 atomic_read(&ccw_device_init_count) == 0);
 158         if (ret)
 159                 return -EINTR;
 160         flush_workqueue(cio_work_q);
 161         return 0;
 162 }
 163
 164 static struct css_driver io_subchannel_driver = {
 165         .drv = {
 166                 .owner = THIS_MODULE,
 167                 .name = "io_subchannel",
 168         },
 169         .subchannel_type = io_subchannel_ids,
 170         .irq = io_subchannel_irq,
 171         .sch_event = io_subchannel_sch_event,
 172         .chp_event = io_subchannel_chp_event,
 173         .probe = io_subchannel_probe,
 174         .remove = io_subchannel_remove,
 175         .shutdown = io_subchannel_shutdown,
 176         .settle = io_subchannel_settle,
 177 };
 178
 179 int __init io_subchannel_init(void)
 180 {
 181         int ret;
 182
 183         timer_setup(&recovery_timer, recovery_func, 0);
 184         ret = bus_register(&ccw_bus_type);
 185         if (ret)
 186                 return ret;
 187         ret = css_driver_register(&io_subchannel_driver);
 188         if (ret)
 189                 bus_unregister(&ccw_bus_type);
 190
 191         return ret;
 192 }
 193
 194
 195 /************************ device handling **************************/
 196
 197 static ssize_t
 198 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 199 {
 200         struct ccw_device *cdev = to_ccwdev(dev);
 201         struct ccw_device_id *id = &(cdev->id);
 202
 203         if (id->dev_type != 0)
 204                 return sysfs_emit(buf, "%04x/%02x\n", id->dev_type, id->dev_model);
 205         else
 206                 return sysfs_emit(buf, "n/a\n");
 207 }
 208
 209 static ssize_t
 210 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 211 {
 212         struct ccw_device *cdev = to_ccwdev(dev);
 213         struct ccw_device_id *id = &(cdev->id);
 214
 215         return sysfs_emit(buf, "%04x/%02x\n", id->cu_type, id->cu_model);
 216 }
 217
 218 static ssize_t
 219 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 220 {
 221         struct ccw_device *cdev = to_ccwdev(dev);
 222         struct ccw_device_id *id = &(cdev->id);
 223         int len;
 224
 225         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 226
 227         return len > PAGE_SIZE ? PAGE_SIZE : len;
 228 }
 229
 230 static ssize_t
 231 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 232 {
 233         struct ccw_device *cdev = to_ccwdev(dev);
 234
 235         return sysfs_emit(buf, cdev->online ? "1\n" : "0\n");
 236 }
 237
 238 int ccw_device_is_orphan(struct ccw_device *cdev)
 239 {
 240         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 241 }
 242
 243 static void ccw_device_unregister(struct ccw_device *cdev)
 244 {
 245         mutex_lock(&cdev->reg_mutex);
 246         if (device_is_registered(&cdev->dev)) {
 247                 /* Undo device_add(). */
 248                 device_del(&cdev->dev);
 249         }
 250         mutex_unlock(&cdev->reg_mutex);
 251
 252         if (cdev->private->flags.initialized) {
 253                 cdev->private->flags.initialized = 0;
 254                 /* Release reference from device_initialize(). */
 255                 put_device(&cdev->dev);
 256         }
 257 }
 258
 259 static void io_subchannel_quiesce(struct subchannel *);
 260
 261 /**
 262  * ccw_device_set_offline() - disable a ccw device for I/O
 263  * @cdev: target ccw device
 264  *
 265  * This function calls the driver's set_offline() function for @cdev, if
 266  * given, and then disables @cdev.
 267  * Returns:
 268  *   %0 on success and a negative error value on failure.
 269  * Context:
 270  *  enabled, ccw device lock not held
 271  */
 272 int ccw_device_set_offline(struct ccw_device *cdev)
 273 {
 274         struct subchannel *sch;
 275         int ret, state;
 276
 277         if (!cdev)
 278                 return -ENODEV;
 279         if (!cdev->online || !cdev->drv)
 280                 return -EINVAL;
 281
 282         if (cdev->drv->set_offline) {
 283                 ret = cdev->drv->set_offline(cdev);
 284                 if (ret != 0)
 285                         return ret;
 286         }
 287         spin_lock_irq(cdev->ccwlock);
 288         sch = to_subchannel(cdev->dev.parent);
 289         cdev->online = 0;
 290         /* Wait until a final state or DISCONNECTED is reached */
 291         while (!dev_fsm_final_state(cdev) &&
 292                cdev->private->state != DEV_STATE_DISCONNECTED) {
 293                 spin_unlock_irq(cdev->ccwlock);
 294                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 295                            cdev->private->state == DEV_STATE_DISCONNECTED));
 296                 spin_lock_irq(cdev->ccwlock);
 297         }
 298         do {
 299                 ret = ccw_device_offline(cdev);
 300                 if (!ret)
 301                         break;
 302                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 303                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 304                               cdev->private->dev_id.devno);
 305                 if (ret != -EBUSY)
 306                         goto error;
 307                 state = cdev->private->state;
 308                 spin_unlock_irq(cdev->ccwlock);
 309                 io_subchannel_quiesce(sch);
 310                 spin_lock_irq(cdev->ccwlock);
 311                 cdev->private->state = state;
 312         } while (ret == -EBUSY);
 313         spin_unlock_irq(cdev->ccwlock);
 314         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 315                    cdev->private->state == DEV_STATE_DISCONNECTED));
 316         /* Inform the user if set offline failed. */
 317         if (cdev->private->state == DEV_STATE_BOXED) {
 318                 pr_warn("%s: The device entered boxed state while being set offline\n",
 319                         dev_name(&cdev->dev));
 320         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 321                 pr_warn("%s: The device stopped operating while being set offline\n",
 322                         dev_name(&cdev->dev));
 323         }
 324         /* Give up reference from ccw_device_set_online(). */
 325         put_device(&cdev->dev);
 326         return 0;
 327
 328 error:
 329         cdev->private->state = DEV_STATE_OFFLINE;
 330         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 331         spin_unlock_irq(cdev->ccwlock);
 332         /* Give up reference from ccw_device_set_online(). */
 333         put_device(&cdev->dev);
 334         return -ENODEV;
 335 }
 336
 337 /**
 338  * ccw_device_set_online() - enable a ccw device for I/O
 339  * @cdev: target ccw device
 340  *
 341  * This function first enables @cdev and then calls the driver's set_online()
 342  * function for @cdev, if given. If set_online() returns an error, @cdev is
 343  * disabled again.
 344  * Returns:
 345  *   %0 on success and a negative error value on failure.
 346  * Context:
 347  *  enabled, ccw device lock not held
 348  */
 349 int ccw_device_set_online(struct ccw_device *cdev)
 350 {
 351         int ret;
 352         int ret2;
 353
 354         if (!cdev)
 355                 return -ENODEV;
 356         if (cdev->online || !cdev->drv)
 357                 return -EINVAL;
 358         /* Hold on to an extra reference while device is online. */
 359         if (!get_device(&cdev->dev))
 360                 return -ENODEV;
 361
 362         spin_lock_irq(cdev->ccwlock);
 363         ret = ccw_device_online(cdev);
 364         if (ret) {
 365                 spin_unlock_irq(cdev->ccwlock);
 366                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 367                               "device 0.%x.%04x\n",
 368                               ret, cdev->private->dev_id.ssid,
 369                               cdev->private->dev_id.devno);
 370                 /* Give up online reference since onlining failed. */
 371                 put_device(&cdev->dev);
 372                 return ret;
 373         }
 374         /* Wait until a final state is reached */
 375         while (!dev_fsm_final_state(cdev)) {
 376                 spin_unlock_irq(cdev->ccwlock);
 377                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 378                 spin_lock_irq(cdev->ccwlock);
 379         }
 380         /* Check if online processing was successful */
 381         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 382             (cdev->private->state != DEV_STATE_W4SENSE)) {
 383                 spin_unlock_irq(cdev->ccwlock);
 384                 /* Inform the user that set online failed. */
 385                 if (cdev->private->state == DEV_STATE_BOXED) {
 386                         pr_warn("%s: Setting the device online failed because it is boxed\n",
 387                                 dev_name(&cdev->dev));
 388                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 389                         pr_warn("%s: Setting the device online failed because it is not operational\n",
 390                                 dev_name(&cdev->dev));
 391                 }
 392                 /* Give up online reference since onlining failed. */
 393                 put_device(&cdev->dev);
 394                 return -ENODEV;
 395         }
 396         spin_unlock_irq(cdev->ccwlock);
 397         if (cdev->drv->set_online)
 398                 ret = cdev->drv->set_online(cdev);
 399         if (ret)
 400                 goto rollback;
 401
 402         spin_lock_irq(cdev->ccwlock);
 403         cdev->online = 1;
 404         spin_unlock_irq(cdev->ccwlock);
 405         return 0;
 406
 407 rollback:
 408         spin_lock_irq(cdev->ccwlock);
 409         /* Wait until a final state or DISCONNECTED is reached */
 410         while (!dev_fsm_final_state(cdev) &&
 411                cdev->private->state != DEV_STATE_DISCONNECTED) {
 412                 spin_unlock_irq(cdev->ccwlock);
 413                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 414                            cdev->private->state == DEV_STATE_DISCONNECTED));
 415                 spin_lock_irq(cdev->ccwlock);
 416         }
 417         ret2 = ccw_device_offline(cdev);
 418         if (ret2)
 419                 goto error;
 420         spin_unlock_irq(cdev->ccwlock);
 421         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 422                    cdev->private->state == DEV_STATE_DISCONNECTED));
 423         /* Give up online reference since onlining failed. */
 424         put_device(&cdev->dev);
 425         return ret;
 426
 427 error:
 428         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 429                       "device 0.%x.%04x\n",
 430                       ret2, cdev->private->dev_id.ssid,
 431                       cdev->private->dev_id.devno);
 432         cdev->private->state = DEV_STATE_OFFLINE;
 433         spin_unlock_irq(cdev->ccwlock);
 434         /* Give up online reference since onlining failed. */
 435         put_device(&cdev->dev);
 436         return ret;
 437 }
 438
 439 static int online_store_handle_offline(struct ccw_device *cdev)
 440 {
 441         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 442                 spin_lock_irq(cdev->ccwlock);
 443                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 444                 spin_unlock_irq(cdev->ccwlock);
 445                 return 0;
 446         }
 447         if (cdev->drv && cdev->drv->set_offline)
 448                 return ccw_device_set_offline(cdev);
 449         return -EINVAL;
 450 }
 451
 452 static int online_store_recog_and_online(struct ccw_device *cdev)
 453 {
 454         /* Do device recognition, if needed. */
 455         if (cdev->private->state == DEV_STATE_BOXED) {
 456                 spin_lock_irq(cdev->ccwlock);
 457                 ccw_device_recognition(cdev);
 458                 spin_unlock_irq(cdev->ccwlock);
 459                 wait_event(cdev->private->wait_q,
 460                            cdev->private->flags.recog_done);
 461                 if (cdev->private->state != DEV_STATE_OFFLINE)
 462                         /* recognition failed */
 463                         return -EAGAIN;
 464         }
 465         if (cdev->drv && cdev->drv->set_online)
 466                 return ccw_device_set_online(cdev);
 467         return -EINVAL;
 468 }
 469
 470 static int online_store_handle_online(struct ccw_device *cdev, int force)
 471 {
 472         int ret;
 473
 474         ret = online_store_recog_and_online(cdev);
 475         if (ret && !force)
 476                 return ret;
 477         if (force && cdev->private->state == DEV_STATE_BOXED) {
 478                 ret = ccw_device_stlck(cdev);
 479                 if (ret)
 480                         return ret;
 481                 if (cdev->id.cu_type == 0)
 482                         cdev->private->state = DEV_STATE_NOT_OPER;
 483                 ret = online_store_recog_and_online(cdev);
 484                 if (ret)
 485                         return ret;
 486         }
 487         return 0;
 488 }
 489
 490 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 491                              const char *buf, size_t count)
 492 {
 493         struct ccw_device *cdev = to_ccwdev(dev);
 494         int force, ret;
 495         unsigned long i;
 496
 497         /* Prevent conflict between multiple on-/offline processing requests. */
 498         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 499                 return -EAGAIN;
 500         /* Prevent conflict between internal I/Os and on-/offline processing. */
 501         if (!dev_fsm_final_state(cdev) &&
 502             cdev->private->state != DEV_STATE_DISCONNECTED) {
 503                 ret = -EAGAIN;
 504                 goto out;
 505         }
 506         /* Prevent conflict between pending work and on-/offline processing.*/
 507         if (work_pending(&cdev->private->todo_work)) {
 508                 ret = -EAGAIN;
 509                 goto out;
 510         }
 511         if (!strncmp(buf, "force\n", count)) {
 512                 force = 1;
 513                 i = 1;
 514                 ret = 0;
 515         } else {
 516                 force = 0;
 517                 ret = kstrtoul(buf, 16, &i);
 518         }
 519         if (ret)
 520                 goto out;
 521
 522         device_lock(dev);
 523         switch (i) {
 524         case 0:
 525                 ret = online_store_handle_offline(cdev);
 526                 break;
 527         case 1:
 528                 ret = online_store_handle_online(cdev, force);
 529                 break;
 530         default:
 531                 ret = -EINVAL;
 532         }
 533         device_unlock(dev);
 534
 535 out:
 536         atomic_set(&cdev->private->onoff, 0);
 537         return (ret < 0) ? ret : count;
 538 }
 539
 540 static ssize_t
 541 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 542 {
 543         struct ccw_device *cdev = to_ccwdev(dev);
 544         struct subchannel *sch;
 545
 546         if (ccw_device_is_orphan(cdev))
 547                 return sysfs_emit(buf, "no device\n");
 548         switch (cdev->private->state) {
 549         case DEV_STATE_BOXED:
 550                 return sysfs_emit(buf, "boxed\n");
 551         case DEV_STATE_DISCONNECTED:
 552         case DEV_STATE_DISCONNECTED_SENSE_ID:
 553         case DEV_STATE_NOT_OPER:
 554                 sch = to_subchannel(dev->parent);
 555                 if (!sch->lpm)
 556                         return sysfs_emit(buf, "no path\n");
 557                 else
 558                         return sysfs_emit(buf, "no device\n");
 559         default:
 560                 /* All other states considered fine. */
 561                 return sysfs_emit(buf, "good\n");
 562         }
 563 }
 564
 565 static ssize_t
 566 initiate_logging(struct device *dev, struct device_attribute *attr,
 567                  const char *buf, size_t count)
 568 {
 569         struct subchannel *sch = to_subchannel(dev);
 570         int rc;
 571
 572         rc = chsc_siosl(sch->schid);
 573         if (rc < 0) {
 574                 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
 575                         sch->schid.ssid, sch->schid.sch_no, rc);
 576                 return rc;
 577         }
 578         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 579                   sch->schid.ssid, sch->schid.sch_no);
 580         return count;
 581 }
 582
 583 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 584                         char *buf)
 585 {
 586         struct subchannel *sch = to_subchannel(dev);
 587
 588         return sysfs_emit(buf, "%02x\n", sch->vpm);
 589 }
 590
 591 static DEVICE_ATTR_RO(devtype);
 592 static DEVICE_ATTR_RO(cutype);
 593 static DEVICE_ATTR_RO(modalias);
 594 static DEVICE_ATTR_RW(online);
 595 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 596 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 597 static DEVICE_ATTR_RO(vpm);
 598
 599 static struct attribute *io_subchannel_attrs[] = {
 600         &dev_attr_logging.attr,
 601         &dev_attr_vpm.attr,
 602         NULL,
 603 };
 604
 605 static const struct attribute_group io_subchannel_attr_group = {
 606         .attrs = io_subchannel_attrs,
 607 };
 608
 609 static struct attribute * ccwdev_attrs[] = {
 610         &dev_attr_devtype.attr,
 611         &dev_attr_cutype.attr,
 612         &dev_attr_modalias.attr,
 613         &dev_attr_online.attr,
 614         &dev_attr_cmb_enable.attr,
 615         &dev_attr_availability.attr,
 616         NULL,
 617 };
 618
 619 static const struct attribute_group ccwdev_attr_group = {
 620         .attrs = ccwdev_attrs,
 621 };
 622
 623 static const struct attribute_group *ccwdev_attr_groups[] = {
 624         &ccwdev_attr_group,
 625         NULL,
 626 };
 627
 628 static int match_dev_id(struct device *dev, const void *data)
 629 {
 630         struct ccw_device *cdev = to_ccwdev(dev);
 631         struct ccw_dev_id *dev_id = (void *)data;
 632
 633         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 634 }
 635
 636 /**
 637  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 638  * @dev_id: id of the device to be searched
 639  *
 640  * This function searches all devices attached to the ccw bus for a device
 641  * matching @dev_id.
 642  * Returns:
 643  *  If a device is found its reference count is increased and returned;
 644  *  else %NULL is returned.
 645  */
 646 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 647 {
 648         struct device *dev;
 649
 650         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 651
 652         return dev ? to_ccwdev(dev) : NULL;
 653 }
 654 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 655
 656 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 657 {
 658         int ret;
 659
 660         mutex_lock(&cdev->reg_mutex);
 661         if (device_is_registered(&cdev->dev)) {
 662                 device_release_driver(&cdev->dev);
 663                 ret = device_attach(&cdev->dev);
 664                 WARN_ON(ret == -ENODEV);
 665         }
 666         mutex_unlock(&cdev->reg_mutex);
 667 }
 668
 669 static void
 670 ccw_device_release(struct device *dev)
 671 {
 672         struct ccw_device *cdev;
 673
 674         cdev = to_ccwdev(dev);
 675         cio_gp_dma_free(cdev->private->dma_pool, cdev->private->dma_area,
 676                         sizeof(*cdev->private->dma_area));
 677         cio_gp_dma_destroy(cdev->private->dma_pool, &cdev->dev);
 678         /* Release reference of parent subchannel. */
 679         put_device(cdev->dev.parent);
 680         kfree(cdev->private);
 681         kfree(cdev);
 682 }
 683
 684 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 685 {
 686         struct ccw_device *cdev;
 687         struct gen_pool *dma_pool;
 688         int ret;
 689
 690         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 691         if (!cdev) {
 692                 ret = -ENOMEM;
 693                 goto err_cdev;
 694         }
 695         cdev->private = kzalloc(sizeof(struct ccw_device_private),
 696                                 GFP_KERNEL | GFP_DMA);
 697         if (!cdev->private) {
 698                 ret = -ENOMEM;
 699                 goto err_priv;
 700         }
 701
 702         cdev->dev.dma_mask = sch->dev.dma_mask;
 703         ret = dma_set_coherent_mask(&cdev->dev, sch->dev.coherent_dma_mask);
 704         if (ret)
 705                 goto err_coherent_mask;
 706
 707         dma_pool = cio_gp_dma_create(&cdev->dev, 1);
 708         if (!dma_pool) {
 709                 ret = -ENOMEM;
 710                 goto err_dma_pool;
 711         }
 712         cdev->private->dma_pool = dma_pool;
 713         cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
 714                                         sizeof(*cdev->private->dma_area));
 715         if (!cdev->private->dma_area) {
 716                 ret = -ENOMEM;
 717                 goto err_dma_area;
 718         }
 719         return cdev;
 720 err_dma_area:
 721         cio_gp_dma_destroy(dma_pool, &cdev->dev);
 722 err_dma_pool:
 723 err_coherent_mask:
 724         kfree(cdev->private);
 725 err_priv:
 726         kfree(cdev);
 727 err_cdev:
 728         return ERR_PTR(ret);
 729 }
 730
 731 static void ccw_device_todo(struct work_struct *work);
 732
 733 static int io_subchannel_initialize_dev(struct subchannel *sch,
 734                                         struct ccw_device *cdev)
 735 {
 736         struct ccw_device_private *priv = cdev->private;
 737         int ret;
 738
 739         priv->cdev = cdev;
 740         priv->int_class = IRQIO_CIO;
 741         priv->state = DEV_STATE_NOT_OPER;
 742         priv->dev_id.devno = sch->schib.pmcw.dev;
 743         priv->dev_id.ssid = sch->schid.ssid;
 744
 745         INIT_WORK(&priv->todo_work, ccw_device_todo);
 746         INIT_LIST_HEAD(&priv->cmb_list);
 747         init_waitqueue_head(&priv->wait_q);
 748         timer_setup(&priv->timer, ccw_device_timeout, 0);
 749         mutex_init(&cdev->reg_mutex);
 750
 751         atomic_set(&priv->onoff, 0);
 752         cdev->ccwlock = &sch->lock;
 753         cdev->dev.parent = &sch->dev;
 754         cdev->dev.release = ccw_device_release;
 755         cdev->dev.bus = &ccw_bus_type;
 756         cdev->dev.groups = ccwdev_attr_groups;
 757         /* Do first half of device_register. */
 758         device_initialize(&cdev->dev);
 759         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 760                            cdev->private->dev_id.devno);
 761         if (ret)
 762                 goto out_put;
 763         if (!get_device(&sch->dev)) {
 764                 ret = -ENODEV;
 765                 goto out_put;
 766         }
 767         priv->flags.initialized = 1;
 768         spin_lock_irq(&sch->lock);
 769         sch_set_cdev(sch, cdev);
 770         spin_unlock_irq(&sch->lock);
 771         return 0;
 772
 773 out_put:
 774         /* Release reference from device_initialize(). */
 775         put_device(&cdev->dev);
 776         return ret;
 777 }
 778
 779 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 780 {
 781         struct ccw_device *cdev;
 782         int ret;
 783
 784         cdev = io_subchannel_allocate_dev(sch);
 785         if (!IS_ERR(cdev)) {
 786                 ret = io_subchannel_initialize_dev(sch, cdev);
 787                 if (ret)
 788                         cdev = ERR_PTR(ret);
 789         }
 790         return cdev;
 791 }
 792
 793 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 794
 795 static void sch_create_and_recog_new_device(struct subchannel *sch)
 796 {
 797         struct ccw_device *cdev;
 798
 799         /* Need to allocate a new ccw device. */
 800         cdev = io_subchannel_create_ccwdev(sch);
 801         if (IS_ERR(cdev)) {
 802                 /* OK, we did everything we could... */
 803                 css_sch_device_unregister(sch);
 804                 return;
 805         }
 806         /* Start recognition for the new ccw device. */
 807         io_subchannel_recog(cdev, sch);
 808 }
 809
 810 /*
 811  * Register recognized device.
 812  */
 813 static void io_subchannel_register(struct ccw_device *cdev)
 814 {
 815         struct subchannel *sch;
 816         int ret, adjust_init_count = 1;
 817         unsigned long flags;
 818
 819         sch = to_subchannel(cdev->dev.parent);
 820         /*
 821          * Check if subchannel is still registered. It may have become
 822          * unregistered if a machine check hit us after finishing
 823          * device recognition but before the register work could be
 824          * queued.
 825          */
 826         if (!device_is_registered(&sch->dev))
 827                 goto out_err;
 828         css_update_ssd_info(sch);
 829         /*
 830          * io_subchannel_register() will also be called after device
 831          * recognition has been done for a boxed device (which will already
 832          * be registered). We need to reprobe since we may now have sense id
 833          * information.
 834          */
 835         mutex_lock(&cdev->reg_mutex);
 836         if (device_is_registered(&cdev->dev)) {
 837                 if (!cdev->drv) {
 838                         ret = device_reprobe(&cdev->dev);
 839                         if (ret)
 840                                 /* We can't do much here. */
 841                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 842                                               " %d for 0.%x.%04x\n", ret,
 843                                               cdev->private->dev_id.ssid,
 844                                               cdev->private->dev_id.devno);
 845                 }
 846                 adjust_init_count = 0;
 847                 goto out;
 848         }
 849         /* make it known to the system */
 850         ret = device_add(&cdev->dev);
 851         if (ret) {
 852                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 853                               cdev->private->dev_id.ssid,
 854                               cdev->private->dev_id.devno, ret);
 855                 spin_lock_irqsave(&sch->lock, flags);
 856                 sch_set_cdev(sch, NULL);
 857                 spin_unlock_irqrestore(&sch->lock, flags);
 858                 mutex_unlock(&cdev->reg_mutex);
 859                 /* Release initial device reference. */
 860                 put_device(&cdev->dev);
 861                 goto out_err;
 862         }
 863 out:
 864         cdev->private->flags.recog_done = 1;
 865         mutex_unlock(&cdev->reg_mutex);
 866         wake_up(&cdev->private->wait_q);
 867 out_err:
 868         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 869                 wake_up(&ccw_device_init_wq);
 870 }
 871
 872 /*
 873  * subchannel recognition done. Called from the state machine.
 874  */
 875 void
 876 io_subchannel_recog_done(struct ccw_device *cdev)
 877 {
 878         if (css_init_done == 0) {
 879                 cdev->private->flags.recog_done = 1;
 880                 return;
 881         }
 882         switch (cdev->private->state) {
 883         case DEV_STATE_BOXED:
 884                 /* Device did not respond in time. */
 885         case DEV_STATE_NOT_OPER:
 886                 cdev->private->flags.recog_done = 1;
 887                 /* Remove device found not operational. */
 888                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 889                 if (atomic_dec_and_test(&ccw_device_init_count))
 890                         wake_up(&ccw_device_init_wq);
 891                 break;
 892         case DEV_STATE_OFFLINE:
 893                 /*
 894                  * We can't register the device in interrupt context so
 895                  * we schedule a work item.
 896                  */
 897                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 898                 break;
 899         }
 900 }
 901
 902 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 903 {
 904         /* Increase counter of devices currently in recognition. */
 905         atomic_inc(&ccw_device_init_count);
 906
 907         /* Start async. device sensing. */
 908         spin_lock_irq(&sch->lock);
 909         ccw_device_recognition(cdev);
 910         spin_unlock_irq(&sch->lock);
 911 }
 912
 913 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 914                                   struct subchannel *sch)
 915 {
 916         struct subchannel *old_sch;
 917         int rc, old_enabled = 0;
 918
 919         old_sch = to_subchannel(cdev->dev.parent);
 920         /* Obtain child reference for new parent. */
 921         if (!get_device(&sch->dev))
 922                 return -ENODEV;
 923
 924         if (!sch_is_pseudo_sch(old_sch)) {
 925                 spin_lock_irq(&old_sch->lock);
 926                 old_enabled = old_sch->schib.pmcw.ena;
 927                 rc = 0;
 928                 if (old_enabled)
 929                         rc = cio_disable_subchannel(old_sch);
 930                 spin_unlock_irq(&old_sch->lock);
 931                 if (rc == -EBUSY) {
 932                         /* Release child reference for new parent. */
 933                         put_device(&sch->dev);
 934                         return rc;
 935                 }
 936         }
 937
 938         mutex_lock(&sch->reg_mutex);
 939         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 940         mutex_unlock(&sch->reg_mutex);
 941         if (rc) {
 942                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 943                               cdev->private->dev_id.ssid,
 944                               cdev->private->dev_id.devno, sch->schid.ssid,
 945                               sch->schib.pmcw.dev, rc);
 946                 if (old_enabled) {
 947                         /* Try to re-enable the old subchannel. */
 948                         spin_lock_irq(&old_sch->lock);
 949                         cio_enable_subchannel(old_sch, (u32)virt_to_phys(old_sch));
 950                         spin_unlock_irq(&old_sch->lock);
 951                 }
 952                 /* Release child reference for new parent. */
 953                 put_device(&sch->dev);
 954                 return rc;
 955         }
 956         /* Clean up old subchannel. */
 957         if (!sch_is_pseudo_sch(old_sch)) {
 958                 spin_lock_irq(&old_sch->lock);
 959                 sch_set_cdev(old_sch, NULL);
 960                 spin_unlock_irq(&old_sch->lock);
 961                 css_schedule_eval(old_sch->schid);
 962         }
 963         /* Release child reference for old parent. */
 964         put_device(&old_sch->dev);
 965         /* Initialize new subchannel. */
 966         spin_lock_irq(&sch->lock);
 967         cdev->ccwlock = &sch->lock;
 968         if (!sch_is_pseudo_sch(sch))
 969                 sch_set_cdev(sch, cdev);
 970         spin_unlock_irq(&sch->lock);
 971         if (!sch_is_pseudo_sch(sch))
 972                 css_update_ssd_info(sch);
 973         return 0;
 974 }
 975
 976 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 977 {
 978         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 979         struct channel_subsystem *css = to_css(sch->dev.parent);
 980
 981         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 982 }
 983
 984 static void io_subchannel_irq(struct subchannel *sch)
 985 {
 986         struct ccw_device *cdev;
 987
 988         cdev = sch_get_cdev(sch);
 989
 990         CIO_TRACE_EVENT(6, "IRQ");
 991         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
 992         if (cdev)
 993                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
 994         else
 995                 inc_irq_stat(IRQIO_CIO);
 996 }
 997
 998 void io_subchannel_init_config(struct subchannel *sch)
 999 {
1000         memset(&sch->config, 0, sizeof(sch->config));
1001         sch->config.csense = 1;
1002 }
1003
1004 static void io_subchannel_init_fields(struct subchannel *sch)
1005 {
1006         if (cio_is_console(sch->schid))
1007                 sch->opm = 0xff;
1008         else
1009                 sch->opm = chp_get_sch_opm(sch);
1010         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1011         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1012
1013         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1014                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1015                       sch->schib.pmcw.dev, sch->schid.ssid,
1016                       sch->schid.sch_no, sch->schib.pmcw.pim,
1017                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1018
1019         io_subchannel_init_config(sch);
1020 }
1021
1022 /*
1023  * Note: We always return 0 so that we bind to the device even on error.
1024  * This is needed so that our remove function is called on unregister.
1025  */
1026 static int io_subchannel_probe(struct subchannel *sch)
1027 {
1028         struct io_subchannel_private *io_priv;
1029         struct ccw_device *cdev;
1030         int rc;
1031
1032         if (cio_is_console(sch->schid)) {
1033                 rc = sysfs_create_group(&sch->dev.kobj,
1034                                         &io_subchannel_attr_group);
1035                 if (rc)
1036                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1037                                       "attributes for subchannel "
1038                                       "0.%x.%04x (rc=%d)\n",
1039                                       sch->schid.ssid, sch->schid.sch_no, rc);
1040                 /*
1041                 * The console subchannel already has an associated ccw_device.
1042                 * Register it and exit.
1043                 */
1044                 cdev = sch_get_cdev(sch);
1045                 rc = device_add(&cdev->dev);
1046                 if (rc) {
1047                         /* Release online reference. */
1048                         put_device(&cdev->dev);
1049                         goto out_schedule;
1050                 }
1051                 if (atomic_dec_and_test(&ccw_device_init_count))
1052                         wake_up(&ccw_device_init_wq);
1053                 return 0;
1054         }
1055         io_subchannel_init_fields(sch);
1056         rc = cio_commit_config(sch);
1057         if (rc)
1058                 goto out_schedule;
1059         rc = sysfs_create_group(&sch->dev.kobj,
1060                                 &io_subchannel_attr_group);
1061         if (rc)
1062                 goto out_schedule;
1063         /* Allocate I/O subchannel private data. */
1064         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1065         if (!io_priv)
1066                 goto out_schedule;
1067
1068         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1069                                 sizeof(*io_priv->dma_area),
1070                                 &io_priv->dma_area_dma, GFP_KERNEL);
1071         if (!io_priv->dma_area) {
1072                 kfree(io_priv);
1073                 goto out_schedule;
1074         }
1075
1076         set_io_private(sch, io_priv);
1077         css_schedule_eval(sch->schid);
1078         return 0;
1079
1080 out_schedule:
1081         spin_lock_irq(&sch->lock);
1082         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1083         spin_unlock_irq(&sch->lock);
1084         return 0;
1085 }
1086
1087 static void io_subchannel_remove(struct subchannel *sch)
1088 {
1089         struct io_subchannel_private *io_priv = to_io_private(sch);
1090         struct ccw_device *cdev;
1091
1092         cdev = sch_get_cdev(sch);
1093         if (!cdev)
1094                 goto out_free;
1095
1096         ccw_device_unregister(cdev);
1097         spin_lock_irq(&sch->lock);
1098         sch_set_cdev(sch, NULL);
1099         set_io_private(sch, NULL);
1100         spin_unlock_irq(&sch->lock);
1101 out_free:
1102         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1103                           io_priv->dma_area, io_priv->dma_area_dma);
1104         kfree(io_priv);
1105         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1106 }
1107
1108 static void io_subchannel_verify(struct subchannel *sch)
1109 {
1110         struct ccw_device *cdev;
1111
1112         cdev = sch_get_cdev(sch);
1113         if (cdev)
1114                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1115         else
1116                 css_schedule_eval(sch->schid);
1117 }
1118
1119 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1120 {
1121         struct ccw_device *cdev;
1122
1123         cdev = sch_get_cdev(sch);
1124         if (!cdev)
1125                 return;
1126         if (cio_update_schib(sch))
1127                 goto err;
1128         /* Check for I/O on path. */
1129         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1130                 goto out;
1131         if (cdev->private->state == DEV_STATE_ONLINE) {
1132                 ccw_device_kill_io(cdev);
1133                 goto out;
1134         }
1135         if (cio_clear(sch))
1136                 goto err;
1137 out:
1138         /* Trigger path verification. */
1139         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1140         return;
1141
1142 err:
1143         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1144 }
1145
1146 static int io_subchannel_chp_event(struct subchannel *sch,
1147                                    struct chp_link *link, int event)
1148 {
1149         struct ccw_device *cdev = sch_get_cdev(sch);
1150         int mask, chpid, valid_bit;
1151         int path_event[8];
1152
1153         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1154         if (!mask)
1155                 return 0;
1156         switch (event) {
1157         case CHP_VARY_OFF:
1158                 sch->opm &= ~mask;
1159                 sch->lpm &= ~mask;
1160                 if (cdev)
1161                         cdev->private->path_gone_mask |= mask;
1162                 io_subchannel_terminate_path(sch, mask);
1163                 break;
1164         case CHP_VARY_ON:
1165                 sch->opm |= mask;
1166                 sch->lpm |= mask;
1167                 if (cdev)
1168                         cdev->private->path_new_mask |= mask;
1169                 io_subchannel_verify(sch);
1170                 break;
1171         case CHP_OFFLINE:
1172                 if (cio_update_schib(sch))
1173                         return -ENODEV;
1174                 if (cdev)
1175                         cdev->private->path_gone_mask |= mask;
1176                 io_subchannel_terminate_path(sch, mask);
1177                 break;
1178         case CHP_ONLINE:
1179                 if (cio_update_schib(sch))
1180                         return -ENODEV;
1181                 sch->lpm |= mask & sch->opm;
1182                 if (cdev)
1183                         cdev->private->path_new_mask |= mask;
1184                 io_subchannel_verify(sch);
1185                 break;
1186         case CHP_FCES_EVENT:
1187                 /* Forward Endpoint Security event */
1188                 for (chpid = 0, valid_bit = 0x80; chpid < 8; chpid++,
1189                                 valid_bit >>= 1) {
1190                         if (mask & valid_bit)
1191                                 path_event[chpid] = PE_PATH_FCES_EVENT;
1192                         else
1193                                 path_event[chpid] = PE_NONE;
1194                 }
1195                 if (cdev && cdev->drv && cdev->drv->path_event)
1196                         cdev->drv->path_event(cdev, path_event);
1197                 break;
1198         }
1199         return 0;
1200 }
1201
1202 static void io_subchannel_quiesce(struct subchannel *sch)
1203 {
1204         struct ccw_device *cdev;
1205         int ret;
1206
1207         spin_lock_irq(&sch->lock);
1208         cdev = sch_get_cdev(sch);
1209         if (cio_is_console(sch->schid))
1210                 goto out_unlock;
1211         if (!sch->schib.pmcw.ena)
1212                 goto out_unlock;
1213         ret = cio_disable_subchannel(sch);
1214         if (ret != -EBUSY)
1215                 goto out_unlock;
1216         if (cdev->handler)
1217                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1218         while (ret == -EBUSY) {
1219                 cdev->private->state = DEV_STATE_QUIESCE;
1220                 cdev->private->iretry = 255;
1221                 ret = ccw_device_cancel_halt_clear(cdev);
1222                 if (ret == -EBUSY) {
1223                         ccw_device_set_timeout(cdev, HZ/10);
1224                         spin_unlock_irq(&sch->lock);
1225                         wait_event(cdev->private->wait_q,
1226                                    cdev->private->state != DEV_STATE_QUIESCE);
1227                         spin_lock_irq(&sch->lock);
1228                 }
1229                 ret = cio_disable_subchannel(sch);
1230         }
1231 out_unlock:
1232         spin_unlock_irq(&sch->lock);
1233 }
1234
1235 static void io_subchannel_shutdown(struct subchannel *sch)
1236 {
1237         io_subchannel_quiesce(sch);
1238 }
1239
1240 static int device_is_disconnected(struct ccw_device *cdev)
1241 {
1242         if (!cdev)
1243                 return 0;
1244         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1245                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1246 }
1247
1248 static int recovery_check(struct device *dev, void *data)
1249 {
1250         struct ccw_device *cdev = to_ccwdev(dev);
1251         struct subchannel *sch;
1252         int *redo = data;
1253
1254         spin_lock_irq(cdev->ccwlock);
1255         switch (cdev->private->state) {
1256         case DEV_STATE_ONLINE:
1257                 sch = to_subchannel(cdev->dev.parent);
1258                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1259                         break;
1260                 fallthrough;
1261         case DEV_STATE_DISCONNECTED:
1262                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1263                               cdev->private->dev_id.ssid,
1264                               cdev->private->dev_id.devno);
1265                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1266                 *redo = 1;
1267                 break;
1268         case DEV_STATE_DISCONNECTED_SENSE_ID:
1269                 *redo = 1;
1270                 break;
1271         }
1272         spin_unlock_irq(cdev->ccwlock);
1273
1274         return 0;
1275 }
1276
1277 static void recovery_work_func(struct work_struct *unused)
1278 {
1279         int redo = 0;
1280
1281         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1282         if (redo) {
1283                 spin_lock_irq(&recovery_lock);
1284                 if (!timer_pending(&recovery_timer)) {
1285                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1286                                 recovery_phase++;
1287                         mod_timer(&recovery_timer, jiffies +
1288                                   recovery_delay[recovery_phase] * HZ);
1289                 }
1290                 spin_unlock_irq(&recovery_lock);
1291         } else
1292                 CIO_MSG_EVENT(3, "recovery: end\n");
1293 }
1294
1295 static DECLARE_WORK(recovery_work, recovery_work_func);
1296
1297 static void recovery_func(struct timer_list *unused)
1298 {
1299         /*
1300          * We can't do our recovery in softirq context and it's not
1301          * performance critical, so we schedule it.
1302          */
1303         schedule_work(&recovery_work);
1304 }
1305
1306 void ccw_device_schedule_recovery(void)
1307 {
1308         unsigned long flags;
1309
1310         CIO_MSG_EVENT(3, "recovery: schedule\n");
1311         spin_lock_irqsave(&recovery_lock, flags);
1312         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1313                 recovery_phase = 0;
1314                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1315         }
1316         spin_unlock_irqrestore(&recovery_lock, flags);
1317 }
1318
1319 static int purge_fn(struct device *dev, void *data)
1320 {
1321         struct ccw_device *cdev = to_ccwdev(dev);
1322         struct ccw_dev_id *id = &cdev->private->dev_id;
1323         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1324
1325         spin_lock_irq(cdev->ccwlock);
1326         if (is_blacklisted(id->ssid, id->devno) &&
1327             (cdev->private->state == DEV_STATE_OFFLINE) &&
1328             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1329                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1330                               id->devno);
1331                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1332                 css_sched_sch_todo(sch, SCH_TODO_UNREG);
1333                 atomic_set(&cdev->private->onoff, 0);
1334         }
1335         spin_unlock_irq(cdev->ccwlock);
1336         /* Abort loop in case of pending signal. */
1337         if (signal_pending(current))
1338                 return -EINTR;
1339
1340         return 0;
1341 }
1342
1343 /**
1344  * ccw_purge_blacklisted - purge unused, blacklisted devices
1345  *
1346  * Unregister all ccw devices that are offline and on the blacklist.
1347  */
1348 int ccw_purge_blacklisted(void)
1349 {
1350         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1351         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1352         return 0;
1353 }
1354
1355 void ccw_device_set_disconnected(struct ccw_device *cdev)
1356 {
1357         if (!cdev)
1358                 return;
1359         ccw_device_set_timeout(cdev, 0);
1360         cdev->private->flags.fake_irb = 0;
1361         cdev->private->state = DEV_STATE_DISCONNECTED;
1362         if (cdev->online)
1363                 ccw_device_schedule_recovery();
1364 }
1365
1366 void ccw_device_set_notoper(struct ccw_device *cdev)
1367 {
1368         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1369
1370         CIO_TRACE_EVENT(2, "notoper");
1371         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1372         ccw_device_set_timeout(cdev, 0);
1373         cio_disable_subchannel(sch);
1374         cdev->private->state = DEV_STATE_NOT_OPER;
1375 }
1376
1377 enum io_sch_action {
1378         IO_SCH_UNREG,
1379         IO_SCH_ORPH_UNREG,
1380         IO_SCH_UNREG_CDEV,
1381         IO_SCH_ATTACH,
1382         IO_SCH_UNREG_ATTACH,
1383         IO_SCH_ORPH_ATTACH,
1384         IO_SCH_REPROBE,
1385         IO_SCH_VERIFY,
1386         IO_SCH_DISC,
1387         IO_SCH_NOP,
1388         IO_SCH_ORPH_CDEV,
1389 };
1390
1391 static enum io_sch_action sch_get_action(struct subchannel *sch)
1392 {
1393         struct ccw_device *cdev;
1394         int rc;
1395
1396         cdev = sch_get_cdev(sch);
1397         rc = cio_update_schib(sch);
1398
1399         if (rc == -ENODEV) {
1400                 /* Not operational. */
1401                 if (!cdev)
1402                         return IO_SCH_UNREG;
1403                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1404                         return IO_SCH_UNREG;
1405                 return IO_SCH_ORPH_UNREG;
1406         }
1407
1408         /* Avoid unregistering subchannels without working device. */
1409         if (rc == -EACCES) {
1410                 if (!cdev)
1411                         return IO_SCH_NOP;
1412                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1413                         return IO_SCH_UNREG_CDEV;
1414                 return IO_SCH_ORPH_CDEV;
1415         }
1416
1417         /* Operational. */
1418         if (!cdev)
1419                 return IO_SCH_ATTACH;
1420         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1421                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1422                         return IO_SCH_UNREG_ATTACH;
1423                 return IO_SCH_ORPH_ATTACH;
1424         }
1425         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1426                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1427                         return IO_SCH_UNREG_CDEV;
1428                 return IO_SCH_DISC;
1429         }
1430         if (device_is_disconnected(cdev))
1431                 return IO_SCH_REPROBE;
1432         if (cdev->online)
1433                 return IO_SCH_VERIFY;
1434         if (cdev->private->state == DEV_STATE_NOT_OPER)
1435                 return IO_SCH_UNREG_ATTACH;
1436         return IO_SCH_NOP;
1437 }
1438
1439 /**
1440  * io_subchannel_sch_event - process subchannel event
1441  * @sch: subchannel
1442  * @process: non-zero if function is called in process context
1443  *
1444  * An unspecified event occurred for this subchannel. Adjust data according
1445  * to the current operational state of the subchannel and device. Return
1446  * zero when the event has been handled sufficiently or -EAGAIN when this
1447  * function should be called again in process context.
1448  */
1449 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1450 {
1451         unsigned long flags;
1452         struct ccw_device *cdev;
1453         struct ccw_dev_id dev_id;
1454         enum io_sch_action action;
1455         int rc = -EAGAIN;
1456
1457         spin_lock_irqsave(&sch->lock, flags);
1458         if (!device_is_registered(&sch->dev))
1459                 goto out_unlock;
1460         if (work_pending(&sch->todo_work))
1461                 goto out_unlock;
1462         cdev = sch_get_cdev(sch);
1463         if (cdev && work_pending(&cdev->private->todo_work))
1464                 goto out_unlock;
1465         action = sch_get_action(sch);
1466         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1467                       sch->schid.ssid, sch->schid.sch_no, process,
1468                       action);
1469         /* Perform immediate actions while holding the lock. */
1470         switch (action) {
1471         case IO_SCH_REPROBE:
1472                 /* Trigger device recognition. */
1473                 ccw_device_trigger_reprobe(cdev);
1474                 rc = 0;
1475                 goto out_unlock;
1476         case IO_SCH_VERIFY:
1477                 /* Trigger path verification. */
1478                 io_subchannel_verify(sch);
1479                 rc = 0;
1480                 goto out_unlock;
1481         case IO_SCH_DISC:
1482                 ccw_device_set_disconnected(cdev);
1483                 rc = 0;
1484                 goto out_unlock;
1485         case IO_SCH_ORPH_UNREG:
1486         case IO_SCH_ORPH_CDEV:
1487         case IO_SCH_ORPH_ATTACH:
1488                 ccw_device_set_disconnected(cdev);
1489                 break;
1490         case IO_SCH_UNREG_CDEV:
1491         case IO_SCH_UNREG_ATTACH:
1492         case IO_SCH_UNREG:
1493                 if (!cdev)
1494                         break;
1495                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1496                         /*
1497                          * Note: delayed work triggered by this event
1498                          * and repeated calls to sch_event are synchronized
1499                          * by the above check for work_pending(cdev).
1500                          */
1501                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1502                 } else
1503                         ccw_device_set_notoper(cdev);
1504                 break;
1505         case IO_SCH_NOP:
1506                 rc = 0;
1507                 goto out_unlock;
1508         default:
1509                 break;
1510         }
1511         spin_unlock_irqrestore(&sch->lock, flags);
1512         /* All other actions require process context. */
1513         if (!process)
1514                 goto out;
1515         /* Handle attached ccw device. */
1516         switch (action) {
1517         case IO_SCH_ORPH_UNREG:
1518         case IO_SCH_ORPH_CDEV:
1519         case IO_SCH_ORPH_ATTACH:
1520                 /* Move ccw device to orphanage. */
1521                 rc = ccw_device_move_to_orph(cdev);
1522                 if (rc)
1523                         goto out;
1524                 break;
1525         case IO_SCH_UNREG_CDEV:
1526         case IO_SCH_UNREG_ATTACH:
1527                 spin_lock_irqsave(&sch->lock, flags);
1528                 sch_set_cdev(sch, NULL);
1529                 spin_unlock_irqrestore(&sch->lock, flags);
1530                 /* Unregister ccw device. */
1531                 ccw_device_unregister(cdev);
1532                 break;
1533         default:
1534                 break;
1535         }
1536         /* Handle subchannel. */
1537         switch (action) {
1538         case IO_SCH_ORPH_UNREG:
1539         case IO_SCH_UNREG:
1540                 css_sch_device_unregister(sch);
1541                 break;
1542         case IO_SCH_ORPH_ATTACH:
1543         case IO_SCH_UNREG_ATTACH:
1544         case IO_SCH_ATTACH:
1545                 dev_id.ssid = sch->schid.ssid;
1546                 dev_id.devno = sch->schib.pmcw.dev;
1547                 cdev = get_ccwdev_by_dev_id(&dev_id);
1548                 if (!cdev) {
1549                         sch_create_and_recog_new_device(sch);
1550                         break;
1551                 }
1552                 rc = ccw_device_move_to_sch(cdev, sch);
1553                 if (rc) {
1554                         /* Release reference from get_ccwdev_by_dev_id() */
1555                         put_device(&cdev->dev);
1556                         goto out;
1557                 }
1558                 spin_lock_irqsave(&sch->lock, flags);
1559                 ccw_device_trigger_reprobe(cdev);
1560                 spin_unlock_irqrestore(&sch->lock, flags);
1561                 /* Release reference from get_ccwdev_by_dev_id() */
1562                 put_device(&cdev->dev);
1563                 break;
1564         default:
1565                 break;
1566         }
1567         return 0;
1568
1569 out_unlock:
1570         spin_unlock_irqrestore(&sch->lock, flags);
1571 out:
1572         return rc;
1573 }
1574
1575 static void ccw_device_set_int_class(struct ccw_device *cdev)
1576 {
1577         struct ccw_driver *cdrv = cdev->drv;
1578
1579         /* Note: we interpret class 0 in this context as an uninitialized
1580          * field since it translates to a non-I/O interrupt class. */
1581         if (cdrv->int_class != 0)
1582                 cdev->private->int_class = cdrv->int_class;
1583         else
1584                 cdev->private->int_class = IRQIO_CIO;
1585 }
1586
1587 #ifdef CONFIG_CCW_CONSOLE
1588 int __init ccw_device_enable_console(struct ccw_device *cdev)
1589 {
1590         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1591         int rc;
1592
1593         if (!cdev->drv || !cdev->handler)
1594                 return -EINVAL;
1595
1596         io_subchannel_init_fields(sch);
1597         rc = cio_commit_config(sch);
1598         if (rc)
1599                 return rc;
1600         sch->driver = &io_subchannel_driver;
1601         io_subchannel_recog(cdev, sch);
1602         /* Now wait for the async. recognition to come to an end. */
1603         spin_lock_irq(cdev->ccwlock);
1604         while (!dev_fsm_final_state(cdev))
1605                 ccw_device_wait_idle(cdev);
1606
1607         /* Hold on to an extra reference while device is online. */
1608         get_device(&cdev->dev);
1609         rc = ccw_device_online(cdev);
1610         if (rc)
1611                 goto out_unlock;
1612
1613         while (!dev_fsm_final_state(cdev))
1614                 ccw_device_wait_idle(cdev);
1615
1616         if (cdev->private->state == DEV_STATE_ONLINE)
1617                 cdev->online = 1;
1618         else
1619                 rc = -EIO;
1620 out_unlock:
1621         spin_unlock_irq(cdev->ccwlock);
1622         if (rc) /* Give up online reference since onlining failed. */
1623                 put_device(&cdev->dev);
1624         return rc;
1625 }
1626
1627 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1628 {
1629         struct io_subchannel_private *io_priv;
1630         struct ccw_device *cdev;
1631         struct subchannel *sch;
1632
1633         sch = cio_probe_console();
1634         if (IS_ERR(sch))
1635                 return ERR_CAST(sch);
1636
1637         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1638         if (!io_priv)
1639                 goto err_priv;
1640         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1641                                 sizeof(*io_priv->dma_area),
1642                                 &io_priv->dma_area_dma, GFP_KERNEL);
1643         if (!io_priv->dma_area)
1644                 goto err_dma_area;
1645         set_io_private(sch, io_priv);
1646         cdev = io_subchannel_create_ccwdev(sch);
1647         if (IS_ERR(cdev)) {
1648                 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1649                                   io_priv->dma_area, io_priv->dma_area_dma);
1650                 set_io_private(sch, NULL);
1651                 put_device(&sch->dev);
1652                 kfree(io_priv);
1653                 return cdev;
1654         }
1655         cdev->drv = drv;
1656         ccw_device_set_int_class(cdev);
1657         return cdev;
1658
1659 err_dma_area:
1660         kfree(io_priv);
1661 err_priv:
1662         put_device(&sch->dev);
1663         return ERR_PTR(-ENOMEM);
1664 }
1665
1666 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1667 {
1668         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1669         struct io_subchannel_private *io_priv = to_io_private(sch);
1670
1671         set_io_private(sch, NULL);
1672         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1673                           io_priv->dma_area, io_priv->dma_area_dma);
1674         put_device(&sch->dev);
1675         put_device(&cdev->dev);
1676         kfree(io_priv);
1677 }
1678
1679 /**
1680  * ccw_device_wait_idle() - busy wait for device to become idle
1681  * @cdev: ccw device
1682  *
1683  * Poll until activity control is zero, that is, no function or data
1684  * transfer is pending/active.
1685  * Called with device lock being held.
1686  */
1687 void ccw_device_wait_idle(struct ccw_device *cdev)
1688 {
1689         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1690
1691         while (1) {
1692                 cio_tsch(sch);
1693                 if (sch->schib.scsw.cmd.actl == 0)
1694                         break;
1695                 udelay(100);
1696         }
1697 }
1698 #endif
1699
1700 /**
1701  * get_ccwdev_by_busid() - obtain device from a bus id
1702  * @cdrv: driver the device is owned by
1703  * @bus_id: bus id of the device to be searched
1704  *
1705  * This function searches all devices owned by @cdrv for a device with a bus
1706  * id matching @bus_id.
1707  * Returns:
1708  *  If a match is found, its reference count of the found device is increased
1709  *  and it is returned; else %NULL is returned.
1710  */
1711 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1712                                        const char *bus_id)
1713 {
1714         struct device *dev;
1715
1716         dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1717
1718         return dev ? to_ccwdev(dev) : NULL;
1719 }
1720
1721 /************************** device driver handling ************************/
1722
1723 /* This is the implementation of the ccw_driver class. The probe, remove
1724  * and release methods are initially very similar to the device_driver
1725  * implementations, with the difference that they have ccw_device
1726  * arguments.
1727  *
1728  * A ccw driver also contains the information that is needed for
1729  * device matching.
1730  */
1731 static int
1732 ccw_device_probe (struct device *dev)
1733 {
1734         struct ccw_device *cdev = to_ccwdev(dev);
1735         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1736         int ret;
1737
1738         cdev->drv = cdrv; /* to let the driver call _set_online */
1739         ccw_device_set_int_class(cdev);
1740         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1741         if (ret) {
1742                 cdev->drv = NULL;
1743                 cdev->private->int_class = IRQIO_CIO;
1744                 return ret;
1745         }
1746
1747         return 0;
1748 }
1749
1750 static void ccw_device_remove(struct device *dev)
1751 {
1752         struct ccw_device *cdev = to_ccwdev(dev);
1753         struct ccw_driver *cdrv = cdev->drv;
1754         struct subchannel *sch;
1755         int ret;
1756
1757         if (cdrv->remove)
1758                 cdrv->remove(cdev);
1759
1760         spin_lock_irq(cdev->ccwlock);
1761         if (cdev->online) {
1762                 cdev->online = 0;
1763                 ret = ccw_device_offline(cdev);
1764                 spin_unlock_irq(cdev->ccwlock);
1765                 if (ret == 0)
1766                         wait_event(cdev->private->wait_q,
1767                                    dev_fsm_final_state(cdev));
1768                 else
1769                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1770                                       "device 0.%x.%04x\n",
1771                                       ret, cdev->private->dev_id.ssid,
1772                                       cdev->private->dev_id.devno);
1773                 /* Give up reference obtained in ccw_device_set_online(). */
1774                 put_device(&cdev->dev);
1775                 spin_lock_irq(cdev->ccwlock);
1776         }
1777         ccw_device_set_timeout(cdev, 0);
1778         cdev->drv = NULL;
1779         cdev->private->int_class = IRQIO_CIO;
1780         sch = to_subchannel(cdev->dev.parent);
1781         spin_unlock_irq(cdev->ccwlock);
1782         io_subchannel_quiesce(sch);
1783         __disable_cmf(cdev);
1784 }
1785
1786 static void ccw_device_shutdown(struct device *dev)
1787 {
1788         struct ccw_device *cdev;
1789
1790         cdev = to_ccwdev(dev);
1791         if (cdev->drv && cdev->drv->shutdown)
1792                 cdev->drv->shutdown(cdev);
1793         __disable_cmf(cdev);
1794 }
1795
1796 static const struct bus_type ccw_bus_type = {
1797         .name   = "ccw",
1798         .match  = ccw_bus_match,
1799         .uevent = ccw_uevent,
1800         .probe  = ccw_device_probe,
1801         .remove = ccw_device_remove,
1802         .shutdown = ccw_device_shutdown,
1803 };
1804
1805 /**
1806  * ccw_driver_register() - register a ccw driver
1807  * @cdriver: driver to be registered
1808  *
1809  * This function is mainly a wrapper around driver_register().
1810  * Returns:
1811  *   %0 on success and a negative error value on failure.
1812  */
1813 int ccw_driver_register(struct ccw_driver *cdriver)
1814 {
1815         struct device_driver *drv = &cdriver->driver;
1816
1817         drv->bus = &ccw_bus_type;
1818
1819         return driver_register(drv);
1820 }
1821
1822 /**
1823  * ccw_driver_unregister() - deregister a ccw driver
1824  * @cdriver: driver to be deregistered
1825  *
1826  * This function is mainly a wrapper around driver_unregister().
1827  */
1828 void ccw_driver_unregister(struct ccw_driver *cdriver)
1829 {
1830         driver_unregister(&cdriver->driver);
1831 }
1832
1833 static void ccw_device_todo(struct work_struct *work)
1834 {
1835         struct ccw_device_private *priv;
1836         struct ccw_device *cdev;
1837         struct subchannel *sch;
1838         enum cdev_todo todo;
1839
1840         priv = container_of(work, struct ccw_device_private, todo_work);
1841         cdev = priv->cdev;
1842         sch = to_subchannel(cdev->dev.parent);
1843         /* Find out todo. */
1844         spin_lock_irq(cdev->ccwlock);
1845         todo = priv->todo;
1846         priv->todo = CDEV_TODO_NOTHING;
1847         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1848                       priv->dev_id.ssid, priv->dev_id.devno, todo);
1849         spin_unlock_irq(cdev->ccwlock);
1850         /* Perform todo. */
1851         switch (todo) {
1852         case CDEV_TODO_ENABLE_CMF:
1853                 cmf_reenable(cdev);
1854                 break;
1855         case CDEV_TODO_REBIND:
1856                 ccw_device_do_unbind_bind(cdev);
1857                 break;
1858         case CDEV_TODO_REGISTER:
1859                 io_subchannel_register(cdev);
1860                 break;
1861         case CDEV_TODO_UNREG_EVAL:
1862                 if (!sch_is_pseudo_sch(sch))
1863                         css_schedule_eval(sch->schid);
1864                 fallthrough;
1865         case CDEV_TODO_UNREG:
1866                 spin_lock_irq(&sch->lock);
1867                 sch_set_cdev(sch, NULL);
1868                 spin_unlock_irq(&sch->lock);
1869                 ccw_device_unregister(cdev);
1870                 break;
1871         default:
1872                 break;
1873         }
1874         /* Release workqueue ref. */
1875         put_device(&cdev->dev);
1876 }
1877
1878 /**
1879  * ccw_device_sched_todo - schedule ccw device operation
1880  * @cdev: ccw device
1881  * @todo: todo
1882  *
1883  * Schedule the operation identified by @todo to be performed on the slow path
1884  * workqueue. Do nothing if another operation with higher priority is already
1885  * scheduled. Needs to be called with ccwdev lock held.
1886  */
1887 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
1888 {
1889         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
1890                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
1891                       todo);
1892         if (cdev->private->todo >= todo)
1893                 return;
1894         cdev->private->todo = todo;
1895         /* Get workqueue ref. */
1896         if (!get_device(&cdev->dev))
1897                 return;
1898         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
1899                 /* Already queued, release workqueue ref. */
1900                 put_device(&cdev->dev);
1901         }
1902 }
1903
1904 /**
1905  * ccw_device_siosl() - initiate logging
1906  * @cdev: ccw device
1907  *
1908  * This function is used to invoke model-dependent logging within the channel
1909  * subsystem.
1910  */
1911 int ccw_device_siosl(struct ccw_device *cdev)
1912 {
1913         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1914
1915         return chsc_siosl(sch->schid);
1916 }
1917 EXPORT_SYMBOL_GPL(ccw_device_siosl);
1918
1919 EXPORT_SYMBOL(ccw_device_set_online);
1920 EXPORT_SYMBOL(ccw_device_set_offline);
1921 EXPORT_SYMBOL(ccw_driver_register);
1922 EXPORT_SYMBOL(ccw_driver_unregister);
1923 EXPORT_SYMBOL(get_ccwdev_by_busid);