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 (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/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
  28 #include <asm/ccwdev.h>
  29 #include <asm/cio.h>
  30 #include <asm/param.h>          /* HZ */
  31 #include <asm/cmb.h>
  32 #include <asm/isc.h>
  33
  34 #include "chp.h"
  35 #include "cio.h"
  36 #include "cio_debug.h"
  37 #include "css.h"
  38 #include "device.h"
  39 #include "ioasm.h"
  40 #include "io_sch.h"
  41 #include "blacklist.h"
  42 #include "chsc.h"
  43
  44 static struct timer_list recovery_timer;
  45 static DEFINE_SPINLOCK(recovery_lock);
  46 static int recovery_phase;
  47 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  48
  49 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
  50 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
  51 static struct bus_type ccw_bus_type;
  52
  53 /******************* bus type handling ***********************/
  54
  55 /* The Linux driver model distinguishes between a bus type and
  56  * the bus itself. Of course we only have one channel
  57  * subsystem driver and one channel system per machine, but
  58  * we still use the abstraction. T.R. says it's a good idea. */
  59 static int
  60 ccw_bus_match (struct device * dev, struct device_driver * drv)
  61 {
  62         struct ccw_device *cdev = to_ccwdev(dev);
  63         struct ccw_driver *cdrv = to_ccwdrv(drv);
  64         const struct ccw_device_id *ids = cdrv->ids, *found;
  65
  66         if (!ids)
  67                 return 0;
  68
  69         found = ccw_device_id_match(ids, &cdev->id);
  70         if (!found)
  71                 return 0;
  72
  73         cdev->id.driver_info = found->driver_info;
  74
  75         return 1;
  76 }
  77
  78 /* Store modalias string delimited by prefix/suffix string into buffer with
  79  * specified size. Return length of resulting string (excluding trailing '\0')
  80  * even if string doesn't fit buffer (snprintf semantics). */
  81 static int snprint_alias(char *buf, size_t size,
  82                          struct ccw_device_id *id, const char *suffix)
  83 {
  84         int len;
  85
  86         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  87         if (len > size)
  88                 return len;
  89         buf += len;
  90         size -= len;
  91
  92         if (id->dev_type != 0)
  93                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  94                                 id->dev_model, suffix);
  95         else
  96                 len += snprintf(buf, size, "dtdm%s", suffix);
  97
  98         return len;
  99 }
 100
 101 /* Set up environment variables for ccw device uevent. Return 0 on success,
 102  * non-zero otherwise. */
 103 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
 104 {
 105         struct ccw_device *cdev = to_ccwdev(dev);
 106         struct ccw_device_id *id = &(cdev->id);
 107         int ret;
 108         char modalias_buf[30];
 109
 110         /* CU_TYPE= */
 111         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 112         if (ret)
 113                 return ret;
 114
 115         /* CU_MODEL= */
 116         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 117         if (ret)
 118                 return ret;
 119
 120         /* The next two can be zero, that's ok for us */
 121         /* DEV_TYPE= */
 122         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 123         if (ret)
 124                 return ret;
 125
 126         /* DEV_MODEL= */
 127         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 128         if (ret)
 129                 return ret;
 130
 131         /* MODALIAS=  */
 132         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 133         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 134         return ret;
 135 }
 136
 137 static void io_subchannel_irq(struct subchannel *);
 138 static int io_subchannel_probe(struct subchannel *);
 139 static int io_subchannel_remove(struct subchannel *);
 140 static void io_subchannel_shutdown(struct subchannel *);
 141 static int io_subchannel_sch_event(struct subchannel *, int);
 142 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 143                                    int);
 144 static void recovery_func(struct timer_list *unused);
 145
 146 static struct css_device_id io_subchannel_ids[] = {
 147         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 148         { /* end of list */ },
 149 };
 150
 151 static int io_subchannel_prepare(struct subchannel *sch)
 152 {
 153         struct ccw_device *cdev;
 154         /*
 155          * Don't allow suspend while a ccw device registration
 156          * is still outstanding.
 157          */
 158         cdev = sch_get_cdev(sch);
 159         if (cdev && !device_is_registered(&cdev->dev))
 160                 return -EAGAIN;
 161         return 0;
 162 }
 163
 164 static int io_subchannel_settle(void)
 165 {
 166         int ret;
 167
 168         ret = wait_event_interruptible(ccw_device_init_wq,
 169                                 atomic_read(&ccw_device_init_count) == 0);
 170         if (ret)
 171                 return -EINTR;
 172         flush_workqueue(cio_work_q);
 173         return 0;
 174 }
 175
 176 static struct css_driver io_subchannel_driver = {
 177         .drv = {
 178                 .owner = THIS_MODULE,
 179                 .name = "io_subchannel",
 180         },
 181         .subchannel_type = io_subchannel_ids,
 182         .irq = io_subchannel_irq,
 183         .sch_event = io_subchannel_sch_event,
 184         .chp_event = io_subchannel_chp_event,
 185         .probe = io_subchannel_probe,
 186         .remove = io_subchannel_remove,
 187         .shutdown = io_subchannel_shutdown,
 188         .prepare = io_subchannel_prepare,
 189         .settle = io_subchannel_settle,
 190 };
 191
 192 int __init io_subchannel_init(void)
 193 {
 194         int ret;
 195
 196         timer_setup(&recovery_timer, recovery_func, 0);
 197         ret = bus_register(&ccw_bus_type);
 198         if (ret)
 199                 return ret;
 200         ret = css_driver_register(&io_subchannel_driver);
 201         if (ret)
 202                 bus_unregister(&ccw_bus_type);
 203
 204         return ret;
 205 }
 206
 207
 208 /************************ device handling **************************/
 209
 210 static ssize_t
 211 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 212 {
 213         struct ccw_device *cdev = to_ccwdev(dev);
 214         struct ccw_device_id *id = &(cdev->id);
 215
 216         if (id->dev_type != 0)
 217                 return sprintf(buf, "%04x/%02x\n",
 218                                 id->dev_type, id->dev_model);
 219         else
 220                 return sprintf(buf, "n/a\n");
 221 }
 222
 223 static ssize_t
 224 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 225 {
 226         struct ccw_device *cdev = to_ccwdev(dev);
 227         struct ccw_device_id *id = &(cdev->id);
 228
 229         return sprintf(buf, "%04x/%02x\n",
 230                        id->cu_type, id->cu_model);
 231 }
 232
 233 static ssize_t
 234 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 235 {
 236         struct ccw_device *cdev = to_ccwdev(dev);
 237         struct ccw_device_id *id = &(cdev->id);
 238         int len;
 239
 240         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 241
 242         return len > PAGE_SIZE ? PAGE_SIZE : len;
 243 }
 244
 245 static ssize_t
 246 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 247 {
 248         struct ccw_device *cdev = to_ccwdev(dev);
 249
 250         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 251 }
 252
 253 int ccw_device_is_orphan(struct ccw_device *cdev)
 254 {
 255         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 256 }
 257
 258 static void ccw_device_unregister(struct ccw_device *cdev)
 259 {
 260         if (device_is_registered(&cdev->dev)) {
 261                 /* Undo device_add(). */
 262                 device_del(&cdev->dev);
 263         }
 264         if (cdev->private->flags.initialized) {
 265                 cdev->private->flags.initialized = 0;
 266                 /* Release reference from device_initialize(). */
 267                 put_device(&cdev->dev);
 268         }
 269 }
 270
 271 static void io_subchannel_quiesce(struct subchannel *);
 272
 273 /**
 274  * ccw_device_set_offline() - disable a ccw device for I/O
 275  * @cdev: target ccw device
 276  *
 277  * This function calls the driver's set_offline() function for @cdev, if
 278  * given, and then disables @cdev.
 279  * Returns:
 280  *   %0 on success and a negative error value on failure.
 281  * Context:
 282  *  enabled, ccw device lock not held
 283  */
 284 int ccw_device_set_offline(struct ccw_device *cdev)
 285 {
 286         struct subchannel *sch;
 287         int ret, state;
 288
 289         if (!cdev)
 290                 return -ENODEV;
 291         if (!cdev->online || !cdev->drv)
 292                 return -EINVAL;
 293
 294         if (cdev->drv->set_offline) {
 295                 ret = cdev->drv->set_offline(cdev);
 296                 if (ret != 0)
 297                         return ret;
 298         }
 299         spin_lock_irq(cdev->ccwlock);
 300         sch = to_subchannel(cdev->dev.parent);
 301         cdev->online = 0;
 302         /* Wait until a final state or DISCONNECTED is reached */
 303         while (!dev_fsm_final_state(cdev) &&
 304                cdev->private->state != DEV_STATE_DISCONNECTED) {
 305                 spin_unlock_irq(cdev->ccwlock);
 306                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 307                            cdev->private->state == DEV_STATE_DISCONNECTED));
 308                 spin_lock_irq(cdev->ccwlock);
 309         }
 310         do {
 311                 ret = ccw_device_offline(cdev);
 312                 if (!ret)
 313                         break;
 314                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 315                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 316                               cdev->private->dev_id.devno);
 317                 if (ret != -EBUSY)
 318                         goto error;
 319                 state = cdev->private->state;
 320                 spin_unlock_irq(cdev->ccwlock);
 321                 io_subchannel_quiesce(sch);
 322                 spin_lock_irq(cdev->ccwlock);
 323                 cdev->private->state = state;
 324         } while (ret == -EBUSY);
 325         spin_unlock_irq(cdev->ccwlock);
 326         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 327                    cdev->private->state == DEV_STATE_DISCONNECTED));
 328         /* Inform the user if set offline failed. */
 329         if (cdev->private->state == DEV_STATE_BOXED) {
 330                 pr_warn("%s: The device entered boxed state while being set offline\n",
 331                         dev_name(&cdev->dev));
 332         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 333                 pr_warn("%s: The device stopped operating while being set offline\n",
 334                         dev_name(&cdev->dev));
 335         }
 336         /* Give up reference from ccw_device_set_online(). */
 337         put_device(&cdev->dev);
 338         return 0;
 339
 340 error:
 341         cdev->private->state = DEV_STATE_OFFLINE;
 342         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 343         spin_unlock_irq(cdev->ccwlock);
 344         /* Give up reference from ccw_device_set_online(). */
 345         put_device(&cdev->dev);
 346         return -ENODEV;
 347 }
 348
 349 /**
 350  * ccw_device_set_online() - enable a ccw device for I/O
 351  * @cdev: target ccw device
 352  *
 353  * This function first enables @cdev and then calls the driver's set_online()
 354  * function for @cdev, if given. If set_online() returns an error, @cdev is
 355  * disabled again.
 356  * Returns:
 357  *   %0 on success and a negative error value on failure.
 358  * Context:
 359  *  enabled, ccw device lock not held
 360  */
 361 int ccw_device_set_online(struct ccw_device *cdev)
 362 {
 363         int ret;
 364         int ret2;
 365
 366         if (!cdev)
 367                 return -ENODEV;
 368         if (cdev->online || !cdev->drv)
 369                 return -EINVAL;
 370         /* Hold on to an extra reference while device is online. */
 371         if (!get_device(&cdev->dev))
 372                 return -ENODEV;
 373
 374         spin_lock_irq(cdev->ccwlock);
 375         ret = ccw_device_online(cdev);
 376         spin_unlock_irq(cdev->ccwlock);
 377         if (ret == 0)
 378                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 379         else {
 380                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 381                               "device 0.%x.%04x\n",
 382                               ret, cdev->private->dev_id.ssid,
 383                               cdev->private->dev_id.devno);
 384                 /* Give up online reference since onlining failed. */
 385                 put_device(&cdev->dev);
 386                 return ret;
 387         }
 388         spin_lock_irq(cdev->ccwlock);
 389         /* Check if online processing was successful */
 390         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 391             (cdev->private->state != DEV_STATE_W4SENSE)) {
 392                 spin_unlock_irq(cdev->ccwlock);
 393                 /* Inform the user that set online failed. */
 394                 if (cdev->private->state == DEV_STATE_BOXED) {
 395                         pr_warn("%s: Setting the device online failed because it is boxed\n",
 396                                 dev_name(&cdev->dev));
 397                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 398                         pr_warn("%s: Setting the device online failed because it is not operational\n",
 399                                 dev_name(&cdev->dev));
 400                 }
 401                 /* Give up online reference since onlining failed. */
 402                 put_device(&cdev->dev);
 403                 return -ENODEV;
 404         }
 405         spin_unlock_irq(cdev->ccwlock);
 406         if (cdev->drv->set_online)
 407                 ret = cdev->drv->set_online(cdev);
 408         if (ret)
 409                 goto rollback;
 410
 411         spin_lock_irq(cdev->ccwlock);
 412         cdev->online = 1;
 413         spin_unlock_irq(cdev->ccwlock);
 414         return 0;
 415
 416 rollback:
 417         spin_lock_irq(cdev->ccwlock);
 418         /* Wait until a final state or DISCONNECTED is reached */
 419         while (!dev_fsm_final_state(cdev) &&
 420                cdev->private->state != DEV_STATE_DISCONNECTED) {
 421                 spin_unlock_irq(cdev->ccwlock);
 422                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 423                            cdev->private->state == DEV_STATE_DISCONNECTED));
 424                 spin_lock_irq(cdev->ccwlock);
 425         }
 426         ret2 = ccw_device_offline(cdev);
 427         if (ret2)
 428                 goto error;
 429         spin_unlock_irq(cdev->ccwlock);
 430         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 431                    cdev->private->state == DEV_STATE_DISCONNECTED));
 432         /* Give up online reference since onlining failed. */
 433         put_device(&cdev->dev);
 434         return ret;
 435
 436 error:
 437         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 438                       "device 0.%x.%04x\n",
 439                       ret2, cdev->private->dev_id.ssid,
 440                       cdev->private->dev_id.devno);
 441         cdev->private->state = DEV_STATE_OFFLINE;
 442         spin_unlock_irq(cdev->ccwlock);
 443         /* Give up online reference since onlining failed. */
 444         put_device(&cdev->dev);
 445         return ret;
 446 }
 447
 448 static int online_store_handle_offline(struct ccw_device *cdev)
 449 {
 450         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 451                 spin_lock_irq(cdev->ccwlock);
 452                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 453                 spin_unlock_irq(cdev->ccwlock);
 454                 return 0;
 455         }
 456         if (cdev->drv && cdev->drv->set_offline)
 457                 return ccw_device_set_offline(cdev);
 458         return -EINVAL;
 459 }
 460
 461 static int online_store_recog_and_online(struct ccw_device *cdev)
 462 {
 463         /* Do device recognition, if needed. */
 464         if (cdev->private->state == DEV_STATE_BOXED) {
 465                 spin_lock_irq(cdev->ccwlock);
 466                 ccw_device_recognition(cdev);
 467                 spin_unlock_irq(cdev->ccwlock);
 468                 wait_event(cdev->private->wait_q,
 469                            cdev->private->flags.recog_done);
 470                 if (cdev->private->state != DEV_STATE_OFFLINE)
 471                         /* recognition failed */
 472                         return -EAGAIN;
 473         }
 474         if (cdev->drv && cdev->drv->set_online)
 475                 return ccw_device_set_online(cdev);
 476         return -EINVAL;
 477 }
 478
 479 static int online_store_handle_online(struct ccw_device *cdev, int force)
 480 {
 481         int ret;
 482
 483         ret = online_store_recog_and_online(cdev);
 484         if (ret && !force)
 485                 return ret;
 486         if (force && cdev->private->state == DEV_STATE_BOXED) {
 487                 ret = ccw_device_stlck(cdev);
 488                 if (ret)
 489                         return ret;
 490                 if (cdev->id.cu_type == 0)
 491                         cdev->private->state = DEV_STATE_NOT_OPER;
 492                 ret = online_store_recog_and_online(cdev);
 493                 if (ret)
 494                         return ret;
 495         }
 496         return 0;
 497 }
 498
 499 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 500                              const char *buf, size_t count)
 501 {
 502         struct ccw_device *cdev = to_ccwdev(dev);
 503         int force, ret;
 504         unsigned long i;
 505
 506         /* Prevent conflict between multiple on-/offline processing requests. */
 507         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 508                 return -EAGAIN;
 509         /* Prevent conflict between internal I/Os and on-/offline processing. */
 510         if (!dev_fsm_final_state(cdev) &&
 511             cdev->private->state != DEV_STATE_DISCONNECTED) {
 512                 ret = -EAGAIN;
 513                 goto out;
 514         }
 515         /* Prevent conflict between pending work and on-/offline processing.*/
 516         if (work_pending(&cdev->private->todo_work)) {
 517                 ret = -EAGAIN;
 518                 goto out;
 519         }
 520         if (!strncmp(buf, "force\n", count)) {
 521                 force = 1;
 522                 i = 1;
 523                 ret = 0;
 524         } else {
 525                 force = 0;
 526                 ret = kstrtoul(buf, 16, &i);
 527         }
 528         if (ret)
 529                 goto out;
 530
 531         device_lock(dev);
 532         switch (i) {
 533         case 0:
 534                 ret = online_store_handle_offline(cdev);
 535                 break;
 536         case 1:
 537                 ret = online_store_handle_online(cdev, force);
 538                 break;
 539         default:
 540                 ret = -EINVAL;
 541         }
 542         device_unlock(dev);
 543
 544 out:
 545         atomic_set(&cdev->private->onoff, 0);
 546         return (ret < 0) ? ret : count;
 547 }
 548
 549 static ssize_t
 550 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 551 {
 552         struct ccw_device *cdev = to_ccwdev(dev);
 553         struct subchannel *sch;
 554
 555         if (ccw_device_is_orphan(cdev))
 556                 return sprintf(buf, "no device\n");
 557         switch (cdev->private->state) {
 558         case DEV_STATE_BOXED:
 559                 return sprintf(buf, "boxed\n");
 560         case DEV_STATE_DISCONNECTED:
 561         case DEV_STATE_DISCONNECTED_SENSE_ID:
 562         case DEV_STATE_NOT_OPER:
 563                 sch = to_subchannel(dev->parent);
 564                 if (!sch->lpm)
 565                         return sprintf(buf, "no path\n");
 566                 else
 567                         return sprintf(buf, "no device\n");
 568         default:
 569                 /* All other states considered fine. */
 570                 return sprintf(buf, "good\n");
 571         }
 572 }
 573
 574 static ssize_t
 575 initiate_logging(struct device *dev, struct device_attribute *attr,
 576                  const char *buf, size_t count)
 577 {
 578         struct subchannel *sch = to_subchannel(dev);
 579         int rc;
 580
 581         rc = chsc_siosl(sch->schid);
 582         if (rc < 0) {
 583                 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
 584                         sch->schid.ssid, sch->schid.sch_no, rc);
 585                 return rc;
 586         }
 587         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 588                   sch->schid.ssid, sch->schid.sch_no);
 589         return count;
 590 }
 591
 592 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 593                         char *buf)
 594 {
 595         struct subchannel *sch = to_subchannel(dev);
 596
 597         return sprintf(buf, "%02x\n", sch->vpm);
 598 }
 599
 600 static DEVICE_ATTR_RO(devtype);
 601 static DEVICE_ATTR_RO(cutype);
 602 static DEVICE_ATTR_RO(modalias);
 603 static DEVICE_ATTR_RW(online);
 604 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 605 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 606 static DEVICE_ATTR_RO(vpm);
 607
 608 static struct attribute *io_subchannel_attrs[] = {
 609         &dev_attr_logging.attr,
 610         &dev_attr_vpm.attr,
 611         NULL,
 612 };
 613
 614 static const struct attribute_group io_subchannel_attr_group = {
 615         .attrs = io_subchannel_attrs,
 616 };
 617
 618 static struct attribute * ccwdev_attrs[] = {
 619         &dev_attr_devtype.attr,
 620         &dev_attr_cutype.attr,
 621         &dev_attr_modalias.attr,
 622         &dev_attr_online.attr,
 623         &dev_attr_cmb_enable.attr,
 624         &dev_attr_availability.attr,
 625         NULL,
 626 };
 627
 628 static const struct attribute_group ccwdev_attr_group = {
 629         .attrs = ccwdev_attrs,
 630 };
 631
 632 static const struct attribute_group *ccwdev_attr_groups[] = {
 633         &ccwdev_attr_group,
 634         NULL,
 635 };
 636
 637 static int ccw_device_add(struct ccw_device *cdev)
 638 {
 639         struct device *dev = &cdev->dev;
 640
 641         dev->bus = &ccw_bus_type;
 642         return device_add(dev);
 643 }
 644
 645 static int match_dev_id(struct device *dev, void *data)
 646 {
 647         struct ccw_device *cdev = to_ccwdev(dev);
 648         struct ccw_dev_id *dev_id = data;
 649
 650         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 651 }
 652
 653 /**
 654  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 655  * @dev_id: id of the device to be searched
 656  *
 657  * This function searches all devices attached to the ccw bus for a device
 658  * matching @dev_id.
 659  * Returns:
 660  *  If a device is found its reference count is increased and returned;
 661  *  else %NULL is returned.
 662  */
 663 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 664 {
 665         struct device *dev;
 666
 667         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 668
 669         return dev ? to_ccwdev(dev) : NULL;
 670 }
 671 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 672
 673 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 674 {
 675         int ret;
 676
 677         if (device_is_registered(&cdev->dev)) {
 678                 device_release_driver(&cdev->dev);
 679                 ret = device_attach(&cdev->dev);
 680                 WARN_ON(ret == -ENODEV);
 681         }
 682 }
 683
 684 static void
 685 ccw_device_release(struct device *dev)
 686 {
 687         struct ccw_device *cdev;
 688
 689         cdev = to_ccwdev(dev);
 690         /* Release reference of parent subchannel. */
 691         put_device(cdev->dev.parent);
 692         kfree(cdev->private);
 693         kfree(cdev);
 694 }
 695
 696 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 697 {
 698         struct ccw_device *cdev;
 699
 700         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 701         if (cdev) {
 702                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 703                                         GFP_KERNEL | GFP_DMA);
 704                 if (cdev->private)
 705                         return cdev;
 706         }
 707         kfree(cdev);
 708         return ERR_PTR(-ENOMEM);
 709 }
 710
 711 static void ccw_device_todo(struct work_struct *work);
 712
 713 static int io_subchannel_initialize_dev(struct subchannel *sch,
 714                                         struct ccw_device *cdev)
 715 {
 716         struct ccw_device_private *priv = cdev->private;
 717         int ret;
 718
 719         priv->cdev = cdev;
 720         priv->int_class = IRQIO_CIO;
 721         priv->state = DEV_STATE_NOT_OPER;
 722         priv->dev_id.devno = sch->schib.pmcw.dev;
 723         priv->dev_id.ssid = sch->schid.ssid;
 724
 725         INIT_WORK(&priv->todo_work, ccw_device_todo);
 726         INIT_LIST_HEAD(&priv->cmb_list);
 727         init_waitqueue_head(&priv->wait_q);
 728         timer_setup(&priv->timer, ccw_device_timeout, 0);
 729
 730         atomic_set(&priv->onoff, 0);
 731         cdev->ccwlock = sch->lock;
 732         cdev->dev.parent = &sch->dev;
 733         cdev->dev.release = ccw_device_release;
 734         cdev->dev.groups = ccwdev_attr_groups;
 735         /* Do first half of device_register. */
 736         device_initialize(&cdev->dev);
 737         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 738                            cdev->private->dev_id.devno);
 739         if (ret)
 740                 goto out_put;
 741         if (!get_device(&sch->dev)) {
 742                 ret = -ENODEV;
 743                 goto out_put;
 744         }
 745         priv->flags.initialized = 1;
 746         spin_lock_irq(sch->lock);
 747         sch_set_cdev(sch, cdev);
 748         spin_unlock_irq(sch->lock);
 749         return 0;
 750
 751 out_put:
 752         /* Release reference from device_initialize(). */
 753         put_device(&cdev->dev);
 754         return ret;
 755 }
 756
 757 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 758 {
 759         struct ccw_device *cdev;
 760         int ret;
 761
 762         cdev = io_subchannel_allocate_dev(sch);
 763         if (!IS_ERR(cdev)) {
 764                 ret = io_subchannel_initialize_dev(sch, cdev);
 765                 if (ret)
 766                         cdev = ERR_PTR(ret);
 767         }
 768         return cdev;
 769 }
 770
 771 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 772
 773 static void sch_create_and_recog_new_device(struct subchannel *sch)
 774 {
 775         struct ccw_device *cdev;
 776
 777         /* Need to allocate a new ccw device. */
 778         cdev = io_subchannel_create_ccwdev(sch);
 779         if (IS_ERR(cdev)) {
 780                 /* OK, we did everything we could... */
 781                 css_sch_device_unregister(sch);
 782                 return;
 783         }
 784         /* Start recognition for the new ccw device. */
 785         io_subchannel_recog(cdev, sch);
 786 }
 787
 788 /*
 789  * Register recognized device.
 790  */
 791 static void io_subchannel_register(struct ccw_device *cdev)
 792 {
 793         struct subchannel *sch;
 794         int ret, adjust_init_count = 1;
 795         unsigned long flags;
 796
 797         sch = to_subchannel(cdev->dev.parent);
 798         /*
 799          * Check if subchannel is still registered. It may have become
 800          * unregistered if a machine check hit us after finishing
 801          * device recognition but before the register work could be
 802          * queued.
 803          */
 804         if (!device_is_registered(&sch->dev))
 805                 goto out_err;
 806         css_update_ssd_info(sch);
 807         /*
 808          * io_subchannel_register() will also be called after device
 809          * recognition has been done for a boxed device (which will already
 810          * be registered). We need to reprobe since we may now have sense id
 811          * information.
 812          */
 813         if (device_is_registered(&cdev->dev)) {
 814                 if (!cdev->drv) {
 815                         ret = device_reprobe(&cdev->dev);
 816                         if (ret)
 817                                 /* We can't do much here. */
 818                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 819                                               " %d for 0.%x.%04x\n", ret,
 820                                               cdev->private->dev_id.ssid,
 821                                               cdev->private->dev_id.devno);
 822                 }
 823                 adjust_init_count = 0;
 824                 goto out;
 825         }
 826         /*
 827          * Now we know this subchannel will stay, we can throw
 828          * our delayed uevent.
 829          */
 830         if (dev_get_uevent_suppress(&sch->dev)) {
 831                 dev_set_uevent_suppress(&sch->dev, 0);
 832                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 833         }
 834         /* make it known to the system */
 835         ret = ccw_device_add(cdev);
 836         if (ret) {
 837                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 838                               cdev->private->dev_id.ssid,
 839                               cdev->private->dev_id.devno, ret);
 840                 spin_lock_irqsave(sch->lock, flags);
 841                 sch_set_cdev(sch, NULL);
 842                 spin_unlock_irqrestore(sch->lock, flags);
 843                 /* Release initial device reference. */
 844                 put_device(&cdev->dev);
 845                 goto out_err;
 846         }
 847 out:
 848         cdev->private->flags.recog_done = 1;
 849         wake_up(&cdev->private->wait_q);
 850 out_err:
 851         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 852                 wake_up(&ccw_device_init_wq);
 853 }
 854
 855 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 856 {
 857         struct subchannel *sch;
 858
 859         /* Get subchannel reference for local processing. */
 860         if (!get_device(cdev->dev.parent))
 861                 return;
 862         sch = to_subchannel(cdev->dev.parent);
 863         css_sch_device_unregister(sch);
 864         /* Release subchannel reference for local processing. */
 865         put_device(&sch->dev);
 866 }
 867
 868 /*
 869  * subchannel recognition done. Called from the state machine.
 870  */
 871 void
 872 io_subchannel_recog_done(struct ccw_device *cdev)
 873 {
 874         if (css_init_done == 0) {
 875                 cdev->private->flags.recog_done = 1;
 876                 return;
 877         }
 878         switch (cdev->private->state) {
 879         case DEV_STATE_BOXED:
 880                 /* Device did not respond in time. */
 881         case DEV_STATE_NOT_OPER:
 882                 cdev->private->flags.recog_done = 1;
 883                 /* Remove device found not operational. */
 884                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 885                 if (atomic_dec_and_test(&ccw_device_init_count))
 886                         wake_up(&ccw_device_init_wq);
 887                 break;
 888         case DEV_STATE_OFFLINE:
 889                 /*
 890                  * We can't register the device in interrupt context so
 891                  * we schedule a work item.
 892                  */
 893                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 894                 break;
 895         }
 896 }
 897
 898 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 899 {
 900         /* Increase counter of devices currently in recognition. */
 901         atomic_inc(&ccw_device_init_count);
 902
 903         /* Start async. device sensing. */
 904         spin_lock_irq(sch->lock);
 905         ccw_device_recognition(cdev);
 906         spin_unlock_irq(sch->lock);
 907 }
 908
 909 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 910                                   struct subchannel *sch)
 911 {
 912         struct subchannel *old_sch;
 913         int rc, old_enabled = 0;
 914
 915         old_sch = to_subchannel(cdev->dev.parent);
 916         /* Obtain child reference for new parent. */
 917         if (!get_device(&sch->dev))
 918                 return -ENODEV;
 919
 920         if (!sch_is_pseudo_sch(old_sch)) {
 921                 spin_lock_irq(old_sch->lock);
 922                 old_enabled = old_sch->schib.pmcw.ena;
 923                 rc = 0;
 924                 if (old_enabled)
 925                         rc = cio_disable_subchannel(old_sch);
 926                 spin_unlock_irq(old_sch->lock);
 927                 if (rc == -EBUSY) {
 928                         /* Release child reference for new parent. */
 929                         put_device(&sch->dev);
 930                         return rc;
 931                 }
 932         }
 933
 934         mutex_lock(&sch->reg_mutex);
 935         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 936         mutex_unlock(&sch->reg_mutex);
 937         if (rc) {
 938                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 939                               cdev->private->dev_id.ssid,
 940                               cdev->private->dev_id.devno, sch->schid.ssid,
 941                               sch->schib.pmcw.dev, rc);
 942                 if (old_enabled) {
 943                         /* Try to reenable the old subchannel. */
 944                         spin_lock_irq(old_sch->lock);
 945                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 946                         spin_unlock_irq(old_sch->lock);
 947                 }
 948                 /* Release child reference for new parent. */
 949                 put_device(&sch->dev);
 950                 return rc;
 951         }
 952         /* Clean up old subchannel. */
 953         if (!sch_is_pseudo_sch(old_sch)) {
 954                 spin_lock_irq(old_sch->lock);
 955                 sch_set_cdev(old_sch, NULL);
 956                 spin_unlock_irq(old_sch->lock);
 957                 css_schedule_eval(old_sch->schid);
 958         }
 959         /* Release child reference for old parent. */
 960         put_device(&old_sch->dev);
 961         /* Initialize new subchannel. */
 962         spin_lock_irq(sch->lock);
 963         cdev->ccwlock = sch->lock;
 964         if (!sch_is_pseudo_sch(sch))
 965                 sch_set_cdev(sch, cdev);
 966         spin_unlock_irq(sch->lock);
 967         if (!sch_is_pseudo_sch(sch))
 968                 css_update_ssd_info(sch);
 969         return 0;
 970 }
 971
 972 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 973 {
 974         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 975         struct channel_subsystem *css = to_css(sch->dev.parent);
 976
 977         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 978 }
 979
 980 static void io_subchannel_irq(struct subchannel *sch)
 981 {
 982         struct ccw_device *cdev;
 983
 984         cdev = sch_get_cdev(sch);
 985
 986         CIO_TRACE_EVENT(6, "IRQ");
 987         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
 988         if (cdev)
 989                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
 990         else
 991                 inc_irq_stat(IRQIO_CIO);
 992 }
 993
 994 void io_subchannel_init_config(struct subchannel *sch)
 995 {
 996         memset(&sch->config, 0, sizeof(sch->config));
 997         sch->config.csense = 1;
 998 }
 999
1000 static void io_subchannel_init_fields(struct subchannel *sch)
1001 {
1002         if (cio_is_console(sch->schid))
1003                 sch->opm = 0xff;
1004         else
1005                 sch->opm = chp_get_sch_opm(sch);
1006         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1007         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1008
1009         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1010                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1011                       sch->schib.pmcw.dev, sch->schid.ssid,
1012                       sch->schid.sch_no, sch->schib.pmcw.pim,
1013                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1014
1015         io_subchannel_init_config(sch);
1016 }
1017
1018 /*
1019  * Note: We always return 0 so that we bind to the device even on error.
1020  * This is needed so that our remove function is called on unregister.
1021  */
1022 static int io_subchannel_probe(struct subchannel *sch)
1023 {
1024         struct io_subchannel_private *io_priv;
1025         struct ccw_device *cdev;
1026         int rc;
1027
1028         if (cio_is_console(sch->schid)) {
1029                 rc = sysfs_create_group(&sch->dev.kobj,
1030                                         &io_subchannel_attr_group);
1031                 if (rc)
1032                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1033                                       "attributes for subchannel "
1034                                       "0.%x.%04x (rc=%d)\n",
1035                                       sch->schid.ssid, sch->schid.sch_no, rc);
1036                 /*
1037                  * The console subchannel already has an associated ccw_device.
1038                  * Throw the delayed uevent for the subchannel, register
1039                  * the ccw_device and exit.
1040                  */
1041                 if (dev_get_uevent_suppress(&sch->dev)) {
1042                         /* should always be the case for the console */
1043                         dev_set_uevent_suppress(&sch->dev, 0);
1044                         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1045                 }
1046                 cdev = sch_get_cdev(sch);
1047                 rc = ccw_device_add(cdev);
1048                 if (rc) {
1049                         /* Release online reference. */
1050                         put_device(&cdev->dev);
1051                         goto out_schedule;
1052                 }
1053                 if (atomic_dec_and_test(&ccw_device_init_count))
1054                         wake_up(&ccw_device_init_wq);
1055                 return 0;
1056         }
1057         io_subchannel_init_fields(sch);
1058         rc = cio_commit_config(sch);
1059         if (rc)
1060                 goto out_schedule;
1061         rc = sysfs_create_group(&sch->dev.kobj,
1062                                 &io_subchannel_attr_group);
1063         if (rc)
1064                 goto out_schedule;
1065         /* Allocate I/O subchannel private data. */
1066         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1067         if (!io_priv)
1068                 goto out_schedule;
1069
1070         set_io_private(sch, io_priv);
1071         css_schedule_eval(sch->schid);
1072         return 0;
1073
1074 out_schedule:
1075         spin_lock_irq(sch->lock);
1076         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1077         spin_unlock_irq(sch->lock);
1078         return 0;
1079 }
1080
1081 static int io_subchannel_remove(struct subchannel *sch)
1082 {
1083         struct io_subchannel_private *io_priv = to_io_private(sch);
1084         struct ccw_device *cdev;
1085
1086         cdev = sch_get_cdev(sch);
1087         if (!cdev)
1088                 goto out_free;
1089
1090         ccw_device_unregister(cdev);
1091         spin_lock_irq(sch->lock);
1092         sch_set_cdev(sch, NULL);
1093         set_io_private(sch, NULL);
1094         spin_unlock_irq(sch->lock);
1095 out_free:
1096         kfree(io_priv);
1097         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1098         return 0;
1099 }
1100
1101 static void io_subchannel_verify(struct subchannel *sch)
1102 {
1103         struct ccw_device *cdev;
1104
1105         cdev = sch_get_cdev(sch);
1106         if (cdev)
1107                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1108 }
1109
1110 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1111 {
1112         struct ccw_device *cdev;
1113
1114         cdev = sch_get_cdev(sch);
1115         if (!cdev)
1116                 return;
1117         if (cio_update_schib(sch))
1118                 goto err;
1119         /* Check for I/O on path. */
1120         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1121                 goto out;
1122         if (cdev->private->state == DEV_STATE_ONLINE) {
1123                 ccw_device_kill_io(cdev);
1124                 goto out;
1125         }
1126         if (cio_clear(sch))
1127                 goto err;
1128 out:
1129         /* Trigger path verification. */
1130         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1131         return;
1132
1133 err:
1134         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1135 }
1136
1137 static int io_subchannel_chp_event(struct subchannel *sch,
1138                                    struct chp_link *link, int event)
1139 {
1140         struct ccw_device *cdev = sch_get_cdev(sch);
1141         int mask;
1142
1143         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1144         if (!mask)
1145                 return 0;
1146         switch (event) {
1147         case CHP_VARY_OFF:
1148                 sch->opm &= ~mask;
1149                 sch->lpm &= ~mask;
1150                 if (cdev)
1151                         cdev->private->path_gone_mask |= mask;
1152                 io_subchannel_terminate_path(sch, mask);
1153                 break;
1154         case CHP_VARY_ON:
1155                 sch->opm |= mask;
1156                 sch->lpm |= mask;
1157                 if (cdev)
1158                         cdev->private->path_new_mask |= mask;
1159                 io_subchannel_verify(sch);
1160                 break;
1161         case CHP_OFFLINE:
1162                 if (cio_update_schib(sch))
1163                         return -ENODEV;
1164                 if (cdev)
1165                         cdev->private->path_gone_mask |= mask;
1166                 io_subchannel_terminate_path(sch, mask);
1167                 break;
1168         case CHP_ONLINE:
1169                 if (cio_update_schib(sch))
1170                         return -ENODEV;
1171                 sch->lpm |= mask & sch->opm;
1172                 if (cdev)
1173                         cdev->private->path_new_mask |= mask;
1174                 io_subchannel_verify(sch);
1175                 break;
1176         }
1177         return 0;
1178 }
1179
1180 static void io_subchannel_quiesce(struct subchannel *sch)
1181 {
1182         struct ccw_device *cdev;
1183         int ret;
1184
1185         spin_lock_irq(sch->lock);
1186         cdev = sch_get_cdev(sch);
1187         if (cio_is_console(sch->schid))
1188                 goto out_unlock;
1189         if (!sch->schib.pmcw.ena)
1190                 goto out_unlock;
1191         ret = cio_disable_subchannel(sch);
1192         if (ret != -EBUSY)
1193                 goto out_unlock;
1194         if (cdev->handler)
1195                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1196         while (ret == -EBUSY) {
1197                 cdev->private->state = DEV_STATE_QUIESCE;
1198                 cdev->private->iretry = 255;
1199                 ret = ccw_device_cancel_halt_clear(cdev);
1200                 if (ret == -EBUSY) {
1201                         ccw_device_set_timeout(cdev, HZ/10);
1202                         spin_unlock_irq(sch->lock);
1203                         wait_event(cdev->private->wait_q,
1204                                    cdev->private->state != DEV_STATE_QUIESCE);
1205                         spin_lock_irq(sch->lock);
1206                 }
1207                 ret = cio_disable_subchannel(sch);
1208         }
1209 out_unlock:
1210         spin_unlock_irq(sch->lock);
1211 }
1212
1213 static void io_subchannel_shutdown(struct subchannel *sch)
1214 {
1215         io_subchannel_quiesce(sch);
1216 }
1217
1218 static int device_is_disconnected(struct ccw_device *cdev)
1219 {
1220         if (!cdev)
1221                 return 0;
1222         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1223                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1224 }
1225
1226 static int recovery_check(struct device *dev, void *data)
1227 {
1228         struct ccw_device *cdev = to_ccwdev(dev);
1229         struct subchannel *sch;
1230         int *redo = data;
1231
1232         spin_lock_irq(cdev->ccwlock);
1233         switch (cdev->private->state) {
1234         case DEV_STATE_ONLINE:
1235                 sch = to_subchannel(cdev->dev.parent);
1236                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1237                         break;
1238                 /* fall through */
1239         case DEV_STATE_DISCONNECTED:
1240                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1241                               cdev->private->dev_id.ssid,
1242                               cdev->private->dev_id.devno);
1243                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1244                 *redo = 1;
1245                 break;
1246         case DEV_STATE_DISCONNECTED_SENSE_ID:
1247                 *redo = 1;
1248                 break;
1249         }
1250         spin_unlock_irq(cdev->ccwlock);
1251
1252         return 0;
1253 }
1254
1255 static void recovery_work_func(struct work_struct *unused)
1256 {
1257         int redo = 0;
1258
1259         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1260         if (redo) {
1261                 spin_lock_irq(&recovery_lock);
1262                 if (!timer_pending(&recovery_timer)) {
1263                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1264                                 recovery_phase++;
1265                         mod_timer(&recovery_timer, jiffies +
1266                                   recovery_delay[recovery_phase] * HZ);
1267                 }
1268                 spin_unlock_irq(&recovery_lock);
1269         } else
1270                 CIO_MSG_EVENT(3, "recovery: end\n");
1271 }
1272
1273 static DECLARE_WORK(recovery_work, recovery_work_func);
1274
1275 static void recovery_func(struct timer_list *unused)
1276 {
1277         /*
1278          * We can't do our recovery in softirq context and it's not
1279          * performance critical, so we schedule it.
1280          */
1281         schedule_work(&recovery_work);
1282 }
1283
1284 void ccw_device_schedule_recovery(void)
1285 {
1286         unsigned long flags;
1287
1288         CIO_MSG_EVENT(3, "recovery: schedule\n");
1289         spin_lock_irqsave(&recovery_lock, flags);
1290         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1291                 recovery_phase = 0;
1292                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1293         }
1294         spin_unlock_irqrestore(&recovery_lock, flags);
1295 }
1296
1297 static int purge_fn(struct device *dev, void *data)
1298 {
1299         struct ccw_device *cdev = to_ccwdev(dev);
1300         struct ccw_dev_id *id = &cdev->private->dev_id;
1301
1302         spin_lock_irq(cdev->ccwlock);
1303         if (is_blacklisted(id->ssid, id->devno) &&
1304             (cdev->private->state == DEV_STATE_OFFLINE) &&
1305             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1306                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1307                               id->devno);
1308                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1309                 atomic_set(&cdev->private->onoff, 0);
1310         }
1311         spin_unlock_irq(cdev->ccwlock);
1312         /* Abort loop in case of pending signal. */
1313         if (signal_pending(current))
1314                 return -EINTR;
1315
1316         return 0;
1317 }
1318
1319 /**
1320  * ccw_purge_blacklisted - purge unused, blacklisted devices
1321  *
1322  * Unregister all ccw devices that are offline and on the blacklist.
1323  */
1324 int ccw_purge_blacklisted(void)
1325 {
1326         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1327         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1328         return 0;
1329 }
1330
1331 void ccw_device_set_disconnected(struct ccw_device *cdev)
1332 {
1333         if (!cdev)
1334                 return;
1335         ccw_device_set_timeout(cdev, 0);
1336         cdev->private->flags.fake_irb = 0;
1337         cdev->private->state = DEV_STATE_DISCONNECTED;
1338         if (cdev->online)
1339                 ccw_device_schedule_recovery();
1340 }
1341
1342 void ccw_device_set_notoper(struct ccw_device *cdev)
1343 {
1344         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1345
1346         CIO_TRACE_EVENT(2, "notoper");
1347         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1348         ccw_device_set_timeout(cdev, 0);
1349         cio_disable_subchannel(sch);
1350         cdev->private->state = DEV_STATE_NOT_OPER;
1351 }
1352
1353 enum io_sch_action {
1354         IO_SCH_UNREG,
1355         IO_SCH_ORPH_UNREG,
1356         IO_SCH_ATTACH,
1357         IO_SCH_UNREG_ATTACH,
1358         IO_SCH_ORPH_ATTACH,
1359         IO_SCH_REPROBE,
1360         IO_SCH_VERIFY,
1361         IO_SCH_DISC,
1362         IO_SCH_NOP,
1363 };
1364
1365 static enum io_sch_action sch_get_action(struct subchannel *sch)
1366 {
1367         struct ccw_device *cdev;
1368
1369         cdev = sch_get_cdev(sch);
1370         if (cio_update_schib(sch)) {
1371                 /* Not operational. */
1372                 if (!cdev)
1373                         return IO_SCH_UNREG;
1374                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1375                         return IO_SCH_UNREG;
1376                 return IO_SCH_ORPH_UNREG;
1377         }
1378         /* Operational. */
1379         if (!cdev)
1380                 return IO_SCH_ATTACH;
1381         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1382                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1383                         return IO_SCH_UNREG_ATTACH;
1384                 return IO_SCH_ORPH_ATTACH;
1385         }
1386         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1387                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1388                         return IO_SCH_UNREG;
1389                 return IO_SCH_DISC;
1390         }
1391         if (device_is_disconnected(cdev))
1392                 return IO_SCH_REPROBE;
1393         if (cdev->online && !cdev->private->flags.resuming)
1394                 return IO_SCH_VERIFY;
1395         if (cdev->private->state == DEV_STATE_NOT_OPER)
1396                 return IO_SCH_UNREG_ATTACH;
1397         return IO_SCH_NOP;
1398 }
1399
1400 /**
1401  * io_subchannel_sch_event - process subchannel event
1402  * @sch: subchannel
1403  * @process: non-zero if function is called in process context
1404  *
1405  * An unspecified event occurred for this subchannel. Adjust data according
1406  * to the current operational state of the subchannel and device. Return
1407  * zero when the event has been handled sufficiently or -EAGAIN when this
1408  * function should be called again in process context.
1409  */
1410 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1411 {
1412         unsigned long flags;
1413         struct ccw_device *cdev;
1414         struct ccw_dev_id dev_id;
1415         enum io_sch_action action;
1416         int rc = -EAGAIN;
1417
1418         spin_lock_irqsave(sch->lock, flags);
1419         if (!device_is_registered(&sch->dev))
1420                 goto out_unlock;
1421         if (work_pending(&sch->todo_work))
1422                 goto out_unlock;
1423         cdev = sch_get_cdev(sch);
1424         if (cdev && work_pending(&cdev->private->todo_work))
1425                 goto out_unlock;
1426         action = sch_get_action(sch);
1427         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1428                       sch->schid.ssid, sch->schid.sch_no, process,
1429                       action);
1430         /* Perform immediate actions while holding the lock. */
1431         switch (action) {
1432         case IO_SCH_REPROBE:
1433                 /* Trigger device recognition. */
1434                 ccw_device_trigger_reprobe(cdev);
1435                 rc = 0;
1436                 goto out_unlock;
1437         case IO_SCH_VERIFY:
1438                 /* Trigger path verification. */
1439                 io_subchannel_verify(sch);
1440                 rc = 0;
1441                 goto out_unlock;
1442         case IO_SCH_DISC:
1443                 ccw_device_set_disconnected(cdev);
1444                 rc = 0;
1445                 goto out_unlock;
1446         case IO_SCH_ORPH_UNREG:
1447         case IO_SCH_ORPH_ATTACH:
1448                 ccw_device_set_disconnected(cdev);
1449                 break;
1450         case IO_SCH_UNREG_ATTACH:
1451         case IO_SCH_UNREG:
1452                 if (!cdev)
1453                         break;
1454                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1455                         /*
1456                          * Note: delayed work triggered by this event
1457                          * and repeated calls to sch_event are synchronized
1458                          * by the above check for work_pending(cdev).
1459                          */
1460                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1461                 } else
1462                         ccw_device_set_notoper(cdev);
1463                 break;
1464         case IO_SCH_NOP:
1465                 rc = 0;
1466                 goto out_unlock;
1467         default:
1468                 break;
1469         }
1470         spin_unlock_irqrestore(sch->lock, flags);
1471         /* All other actions require process context. */
1472         if (!process)
1473                 goto out;
1474         /* Handle attached ccw device. */
1475         switch (action) {
1476         case IO_SCH_ORPH_UNREG:
1477         case IO_SCH_ORPH_ATTACH:
1478                 /* Move ccw device to orphanage. */
1479                 rc = ccw_device_move_to_orph(cdev);
1480                 if (rc)
1481                         goto out;
1482                 break;
1483         case IO_SCH_UNREG_ATTACH:
1484                 spin_lock_irqsave(sch->lock, flags);
1485                 if (cdev->private->flags.resuming) {
1486                         /* Device will be handled later. */
1487                         rc = 0;
1488                         goto out_unlock;
1489                 }
1490                 sch_set_cdev(sch, NULL);
1491                 spin_unlock_irqrestore(sch->lock, flags);
1492                 /* Unregister ccw device. */
1493                 ccw_device_unregister(cdev);
1494                 break;
1495         default:
1496                 break;
1497         }
1498         /* Handle subchannel. */
1499         switch (action) {
1500         case IO_SCH_ORPH_UNREG:
1501         case IO_SCH_UNREG:
1502                 if (!cdev || !cdev->private->flags.resuming)
1503                         css_sch_device_unregister(sch);
1504                 break;
1505         case IO_SCH_ORPH_ATTACH:
1506         case IO_SCH_UNREG_ATTACH:
1507         case IO_SCH_ATTACH:
1508                 dev_id.ssid = sch->schid.ssid;
1509                 dev_id.devno = sch->schib.pmcw.dev;
1510                 cdev = get_ccwdev_by_dev_id(&dev_id);
1511                 if (!cdev) {
1512                         sch_create_and_recog_new_device(sch);
1513                         break;
1514                 }
1515                 rc = ccw_device_move_to_sch(cdev, sch);
1516                 if (rc) {
1517                         /* Release reference from get_ccwdev_by_dev_id() */
1518                         put_device(&cdev->dev);
1519                         goto out;
1520                 }
1521                 spin_lock_irqsave(sch->lock, flags);
1522                 ccw_device_trigger_reprobe(cdev);
1523                 spin_unlock_irqrestore(sch->lock, flags);
1524                 /* Release reference from get_ccwdev_by_dev_id() */
1525                 put_device(&cdev->dev);
1526                 break;
1527         default:
1528                 break;
1529         }
1530         return 0;
1531
1532 out_unlock:
1533         spin_unlock_irqrestore(sch->lock, flags);
1534 out:
1535         return rc;
1536 }
1537
1538 static void ccw_device_set_int_class(struct ccw_device *cdev)
1539 {
1540         struct ccw_driver *cdrv = cdev->drv;
1541
1542         /* Note: we interpret class 0 in this context as an uninitialized
1543          * field since it translates to a non-I/O interrupt class. */
1544         if (cdrv->int_class != 0)
1545                 cdev->private->int_class = cdrv->int_class;
1546         else
1547                 cdev->private->int_class = IRQIO_CIO;
1548 }
1549
1550 #ifdef CONFIG_CCW_CONSOLE
1551 int __init ccw_device_enable_console(struct ccw_device *cdev)
1552 {
1553         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1554         int rc;
1555
1556         if (!cdev->drv || !cdev->handler)
1557                 return -EINVAL;
1558
1559         io_subchannel_init_fields(sch);
1560         rc = cio_commit_config(sch);
1561         if (rc)
1562                 return rc;
1563         sch->driver = &io_subchannel_driver;
1564         io_subchannel_recog(cdev, sch);
1565         /* Now wait for the async. recognition to come to an end. */
1566         spin_lock_irq(cdev->ccwlock);
1567         while (!dev_fsm_final_state(cdev))
1568                 ccw_device_wait_idle(cdev);
1569
1570         /* Hold on to an extra reference while device is online. */
1571         get_device(&cdev->dev);
1572         rc = ccw_device_online(cdev);
1573         if (rc)
1574                 goto out_unlock;
1575
1576         while (!dev_fsm_final_state(cdev))
1577                 ccw_device_wait_idle(cdev);
1578
1579         if (cdev->private->state == DEV_STATE_ONLINE)
1580                 cdev->online = 1;
1581         else
1582                 rc = -EIO;
1583 out_unlock:
1584         spin_unlock_irq(cdev->ccwlock);
1585         if (rc) /* Give up online reference since onlining failed. */
1586                 put_device(&cdev->dev);
1587         return rc;
1588 }
1589
1590 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1591 {
1592         struct io_subchannel_private *io_priv;
1593         struct ccw_device *cdev;
1594         struct subchannel *sch;
1595
1596         sch = cio_probe_console();
1597         if (IS_ERR(sch))
1598                 return ERR_CAST(sch);
1599
1600         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1601         if (!io_priv) {
1602                 put_device(&sch->dev);
1603                 return ERR_PTR(-ENOMEM);
1604         }
1605         set_io_private(sch, io_priv);
1606         cdev = io_subchannel_create_ccwdev(sch);
1607         if (IS_ERR(cdev)) {
1608                 put_device(&sch->dev);
1609                 kfree(io_priv);
1610                 return cdev;
1611         }
1612         cdev->drv = drv;
1613         ccw_device_set_int_class(cdev);
1614         return cdev;
1615 }
1616
1617 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1618 {
1619         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1620         struct io_subchannel_private *io_priv = to_io_private(sch);
1621
1622         set_io_private(sch, NULL);
1623         put_device(&sch->dev);
1624         put_device(&cdev->dev);
1625         kfree(io_priv);
1626 }
1627
1628 /**
1629  * ccw_device_wait_idle() - busy wait for device to become idle
1630  * @cdev: ccw device
1631  *
1632  * Poll until activity control is zero, that is, no function or data
1633  * transfer is pending/active.
1634  * Called with device lock being held.
1635  */
1636 void ccw_device_wait_idle(struct ccw_device *cdev)
1637 {
1638         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1639
1640         while (1) {
1641                 cio_tsch(sch);
1642                 if (sch->schib.scsw.cmd.actl == 0)
1643                         break;
1644                 udelay_simple(100);
1645         }
1646 }
1647
1648 static int ccw_device_pm_restore(struct device *dev);
1649
1650 int ccw_device_force_console(struct ccw_device *cdev)
1651 {
1652         return ccw_device_pm_restore(&cdev->dev);
1653 }
1654 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1655 #endif
1656
1657 /*
1658  * get ccw_device matching the busid, but only if owned by cdrv
1659  */
1660 static int
1661 __ccwdev_check_busid(struct device *dev, void *id)
1662 {
1663         char *bus_id;
1664
1665         bus_id = id;
1666
1667         return (strcmp(bus_id, dev_name(dev)) == 0);
1668 }
1669
1670
1671 /**
1672  * get_ccwdev_by_busid() - obtain device from a bus id
1673  * @cdrv: driver the device is owned by
1674  * @bus_id: bus id of the device to be searched
1675  *
1676  * This function searches all devices owned by @cdrv for a device with a bus
1677  * id matching @bus_id.
1678  * Returns:
1679  *  If a match is found, its reference count of the found device is increased
1680  *  and it is returned; else %NULL is returned.
1681  */
1682 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1683                                        const char *bus_id)
1684 {
1685         struct device *dev;
1686
1687         dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
1688                                  __ccwdev_check_busid);
1689
1690         return dev ? to_ccwdev(dev) : NULL;
1691 }
1692
1693 /************************** device driver handling ************************/
1694
1695 /* This is the implementation of the ccw_driver class. The probe, remove
1696  * and release methods are initially very similar to the device_driver
1697  * implementations, with the difference that they have ccw_device
1698  * arguments.
1699  *
1700  * A ccw driver also contains the information that is needed for
1701  * device matching.
1702  */
1703 static int
1704 ccw_device_probe (struct device *dev)
1705 {
1706         struct ccw_device *cdev = to_ccwdev(dev);
1707         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1708         int ret;
1709
1710         cdev->drv = cdrv; /* to let the driver call _set_online */
1711         ccw_device_set_int_class(cdev);
1712         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1713         if (ret) {
1714                 cdev->drv = NULL;
1715                 cdev->private->int_class = IRQIO_CIO;
1716                 return ret;
1717         }
1718
1719         return 0;
1720 }
1721
1722 static int ccw_device_remove(struct device *dev)
1723 {
1724         struct ccw_device *cdev = to_ccwdev(dev);
1725         struct ccw_driver *cdrv = cdev->drv;
1726         struct subchannel *sch;
1727         int ret;
1728
1729         if (cdrv->remove)
1730                 cdrv->remove(cdev);
1731
1732         spin_lock_irq(cdev->ccwlock);
1733         if (cdev->online) {
1734                 cdev->online = 0;
1735                 ret = ccw_device_offline(cdev);
1736                 spin_unlock_irq(cdev->ccwlock);
1737                 if (ret == 0)
1738                         wait_event(cdev->private->wait_q,
1739                                    dev_fsm_final_state(cdev));
1740                 else
1741                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1742                                       "device 0.%x.%04x\n",
1743                                       ret, cdev->private->dev_id.ssid,
1744                                       cdev->private->dev_id.devno);
1745                 /* Give up reference obtained in ccw_device_set_online(). */
1746                 put_device(&cdev->dev);
1747                 spin_lock_irq(cdev->ccwlock);
1748         }
1749         ccw_device_set_timeout(cdev, 0);
1750         cdev->drv = NULL;
1751         cdev->private->int_class = IRQIO_CIO;
1752         sch = to_subchannel(cdev->dev.parent);
1753         spin_unlock_irq(cdev->ccwlock);
1754         io_subchannel_quiesce(sch);
1755         __disable_cmf(cdev);
1756
1757         return 0;
1758 }
1759
1760 static void ccw_device_shutdown(struct device *dev)
1761 {
1762         struct ccw_device *cdev;
1763
1764         cdev = to_ccwdev(dev);
1765         if (cdev->drv && cdev->drv->shutdown)
1766                 cdev->drv->shutdown(cdev);
1767         __disable_cmf(cdev);
1768 }
1769
1770 static int ccw_device_pm_prepare(struct device *dev)
1771 {
1772         struct ccw_device *cdev = to_ccwdev(dev);
1773
1774         if (work_pending(&cdev->private->todo_work))
1775                 return -EAGAIN;
1776         /* Fail while device is being set online/offline. */
1777         if (atomic_read(&cdev->private->onoff))
1778                 return -EAGAIN;
1779
1780         if (cdev->online && cdev->drv && cdev->drv->prepare)
1781                 return cdev->drv->prepare(cdev);
1782
1783         return 0;
1784 }
1785
1786 static void ccw_device_pm_complete(struct device *dev)
1787 {
1788         struct ccw_device *cdev = to_ccwdev(dev);
1789
1790         if (cdev->online && cdev->drv && cdev->drv->complete)
1791                 cdev->drv->complete(cdev);
1792 }
1793
1794 static int ccw_device_pm_freeze(struct device *dev)
1795 {
1796         struct ccw_device *cdev = to_ccwdev(dev);
1797         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1798         int ret, cm_enabled;
1799
1800         /* Fail suspend while device is in transistional state. */
1801         if (!dev_fsm_final_state(cdev))
1802                 return -EAGAIN;
1803         if (!cdev->online)
1804                 return 0;
1805         if (cdev->drv && cdev->drv->freeze) {
1806                 ret = cdev->drv->freeze(cdev);
1807                 if (ret)
1808                         return ret;
1809         }
1810
1811         spin_lock_irq(sch->lock);
1812         cm_enabled = cdev->private->cmb != NULL;
1813         spin_unlock_irq(sch->lock);
1814         if (cm_enabled) {
1815                 /* Don't have the css write on memory. */
1816                 ret = ccw_set_cmf(cdev, 0);
1817                 if (ret)
1818                         return ret;
1819         }
1820         /* From here on, disallow device driver I/O. */
1821         spin_lock_irq(sch->lock);
1822         ret = cio_disable_subchannel(sch);
1823         spin_unlock_irq(sch->lock);
1824
1825         return ret;
1826 }
1827
1828 static int ccw_device_pm_thaw(struct device *dev)
1829 {
1830         struct ccw_device *cdev = to_ccwdev(dev);
1831         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1832         int ret, cm_enabled;
1833
1834         if (!cdev->online)
1835                 return 0;
1836
1837         spin_lock_irq(sch->lock);
1838         /* Allow device driver I/O again. */
1839         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1840         cm_enabled = cdev->private->cmb != NULL;
1841         spin_unlock_irq(sch->lock);
1842         if (ret)
1843                 return ret;
1844
1845         if (cm_enabled) {
1846                 ret = ccw_set_cmf(cdev, 1);
1847                 if (ret)
1848                         return ret;
1849         }
1850
1851         if (cdev->drv && cdev->drv->thaw)
1852                 ret = cdev->drv->thaw(cdev);
1853
1854         return ret;
1855 }
1856
1857 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1858 {
1859         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1860
1861         spin_lock_irq(sch->lock);
1862         if (cio_is_console(sch->schid)) {
1863                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1864                 goto out_unlock;
1865         }
1866         /*
1867          * While we were sleeping, devices may have gone or become
1868          * available again. Kick re-detection.
1869          */
1870         cdev->private->flags.resuming = 1;
1871         cdev->private->path_new_mask = LPM_ANYPATH;
1872         css_sched_sch_todo(sch, SCH_TODO_EVAL);
1873         spin_unlock_irq(sch->lock);
1874         css_wait_for_slow_path();
1875
1876         /* cdev may have been moved to a different subchannel. */
1877         sch = to_subchannel(cdev->dev.parent);
1878         spin_lock_irq(sch->lock);
1879         if (cdev->private->state != DEV_STATE_ONLINE &&
1880             cdev->private->state != DEV_STATE_OFFLINE)
1881                 goto out_unlock;
1882
1883         ccw_device_recognition(cdev);
1884         spin_unlock_irq(sch->lock);
1885         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1886                    cdev->private->state == DEV_STATE_DISCONNECTED);
1887         spin_lock_irq(sch->lock);
1888
1889 out_unlock:
1890         cdev->private->flags.resuming = 0;
1891         spin_unlock_irq(sch->lock);
1892 }
1893
1894 static int resume_handle_boxed(struct ccw_device *cdev)
1895 {
1896         cdev->private->state = DEV_STATE_BOXED;
1897         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1898                 return 0;
1899         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1900         return -ENODEV;
1901 }
1902
1903 static int resume_handle_disc(struct ccw_device *cdev)
1904 {
1905         cdev->private->state = DEV_STATE_DISCONNECTED;
1906         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1907                 return 0;
1908         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1909         return -ENODEV;
1910 }
1911
1912 static int ccw_device_pm_restore(struct device *dev)
1913 {
1914         struct ccw_device *cdev = to_ccwdev(dev);
1915         struct subchannel *sch;
1916         int ret = 0;
1917
1918         __ccw_device_pm_restore(cdev);
1919         sch = to_subchannel(cdev->dev.parent);
1920         spin_lock_irq(sch->lock);
1921         if (cio_is_console(sch->schid))
1922                 goto out_restore;
1923
1924         /* check recognition results */
1925         switch (cdev->private->state) {
1926         case DEV_STATE_OFFLINE:
1927         case DEV_STATE_ONLINE:
1928                 cdev->private->flags.donotify = 0;
1929                 break;
1930         case DEV_STATE_BOXED:
1931                 ret = resume_handle_boxed(cdev);
1932                 if (ret)
1933                         goto out_unlock;
1934                 goto out_restore;
1935         default:
1936                 ret = resume_handle_disc(cdev);
1937                 if (ret)
1938                         goto out_unlock;
1939                 goto out_restore;
1940         }
1941         /* check if the device type has changed */
1942         if (!ccw_device_test_sense_data(cdev)) {
1943                 ccw_device_update_sense_data(cdev);
1944                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1945                 ret = -ENODEV;
1946                 goto out_unlock;
1947         }
1948         if (!cdev->online)
1949                 goto out_unlock;
1950
1951         if (ccw_device_online(cdev)) {
1952                 ret = resume_handle_disc(cdev);
1953                 if (ret)
1954                         goto out_unlock;
1955                 goto out_restore;
1956         }
1957         spin_unlock_irq(sch->lock);
1958         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1959         spin_lock_irq(sch->lock);
1960
1961         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1962                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1963                 ret = -ENODEV;
1964                 goto out_unlock;
1965         }
1966
1967         /* reenable cmf, if needed */
1968         if (cdev->private->cmb) {
1969                 spin_unlock_irq(sch->lock);
1970                 ret = ccw_set_cmf(cdev, 1);
1971                 spin_lock_irq(sch->lock);
1972                 if (ret) {
1973                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1974                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1975                                       cdev->private->dev_id.devno, ret);
1976                         ret = 0;
1977                 }
1978         }
1979
1980 out_restore:
1981         spin_unlock_irq(sch->lock);
1982         if (cdev->online && cdev->drv && cdev->drv->restore)
1983                 ret = cdev->drv->restore(cdev);
1984         return ret;
1985
1986 out_unlock:
1987         spin_unlock_irq(sch->lock);
1988         return ret;
1989 }
1990
1991 static const struct dev_pm_ops ccw_pm_ops = {
1992         .prepare = ccw_device_pm_prepare,
1993         .complete = ccw_device_pm_complete,
1994         .freeze = ccw_device_pm_freeze,
1995         .thaw = ccw_device_pm_thaw,
1996         .restore = ccw_device_pm_restore,
1997 };
1998
1999 static struct bus_type ccw_bus_type = {
2000         .name   = "ccw",
2001         .match  = ccw_bus_match,
2002         .uevent = ccw_uevent,
2003         .probe  = ccw_device_probe,
2004         .remove = ccw_device_remove,
2005         .shutdown = ccw_device_shutdown,
2006         .pm = &ccw_pm_ops,
2007 };
2008
2009 /**
2010  * ccw_driver_register() - register a ccw driver
2011  * @cdriver: driver to be registered
2012  *
2013  * This function is mainly a wrapper around driver_register().
2014  * Returns:
2015  *   %0 on success and a negative error value on failure.
2016  */
2017 int ccw_driver_register(struct ccw_driver *cdriver)
2018 {
2019         struct device_driver *drv = &cdriver->driver;
2020
2021         drv->bus = &ccw_bus_type;
2022
2023         return driver_register(drv);
2024 }
2025
2026 /**
2027  * ccw_driver_unregister() - deregister a ccw driver
2028  * @cdriver: driver to be deregistered
2029  *
2030  * This function is mainly a wrapper around driver_unregister().
2031  */
2032 void ccw_driver_unregister(struct ccw_driver *cdriver)
2033 {
2034         driver_unregister(&cdriver->driver);
2035 }
2036
2037 static void ccw_device_todo(struct work_struct *work)
2038 {
2039         struct ccw_device_private *priv;
2040         struct ccw_device *cdev;
2041         struct subchannel *sch;
2042         enum cdev_todo todo;
2043
2044         priv = container_of(work, struct ccw_device_private, todo_work);
2045         cdev = priv->cdev;
2046         sch = to_subchannel(cdev->dev.parent);
2047         /* Find out todo. */
2048         spin_lock_irq(cdev->ccwlock);
2049         todo = priv->todo;
2050         priv->todo = CDEV_TODO_NOTHING;
2051         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2052                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2053         spin_unlock_irq(cdev->ccwlock);
2054         /* Perform todo. */
2055         switch (todo) {
2056         case CDEV_TODO_ENABLE_CMF:
2057                 cmf_reenable(cdev);
2058                 break;
2059         case CDEV_TODO_REBIND:
2060                 ccw_device_do_unbind_bind(cdev);
2061                 break;
2062         case CDEV_TODO_REGISTER:
2063                 io_subchannel_register(cdev);
2064                 break;
2065         case CDEV_TODO_UNREG_EVAL:
2066                 if (!sch_is_pseudo_sch(sch))
2067                         css_schedule_eval(sch->schid);
2068                 /* fall-through */
2069         case CDEV_TODO_UNREG:
2070                 if (sch_is_pseudo_sch(sch))
2071                         ccw_device_unregister(cdev);
2072                 else
2073                         ccw_device_call_sch_unregister(cdev);
2074                 break;
2075         default:
2076                 break;
2077         }
2078         /* Release workqueue ref. */
2079         put_device(&cdev->dev);
2080 }
2081
2082 /**
2083  * ccw_device_sched_todo - schedule ccw device operation
2084  * @cdev: ccw device
2085  * @todo: todo
2086  *
2087  * Schedule the operation identified by @todo to be performed on the slow path
2088  * workqueue. Do nothing if another operation with higher priority is already
2089  * scheduled. Needs to be called with ccwdev lock held.
2090  */
2091 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2092 {
2093         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2094                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2095                       todo);
2096         if (cdev->private->todo >= todo)
2097                 return;
2098         cdev->private->todo = todo;
2099         /* Get workqueue ref. */
2100         if (!get_device(&cdev->dev))
2101                 return;
2102         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2103                 /* Already queued, release workqueue ref. */
2104                 put_device(&cdev->dev);
2105         }
2106 }
2107
2108 /**
2109  * ccw_device_siosl() - initiate logging
2110  * @cdev: ccw device
2111  *
2112  * This function is used to invoke model-dependent logging within the channel
2113  * subsystem.
2114  */
2115 int ccw_device_siosl(struct ccw_device *cdev)
2116 {
2117         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2118
2119         return chsc_siosl(sch->schid);
2120 }
2121 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2122
2123 EXPORT_SYMBOL(ccw_device_set_online);
2124 EXPORT_SYMBOL(ccw_device_set_offline);
2125 EXPORT_SYMBOL(ccw_driver_register);
2126 EXPORT_SYMBOL(ccw_driver_unregister);
2127 EXPORT_SYMBOL(get_ccwdev_by_busid);