drivers/s390/cio/device.c

   1 /*
   2  *  bus driver for ccw devices
   3  *
   4  *    Copyright IBM Corp. 2002, 2008
   5  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   6  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8  */
   9
  10 #define KMSG_COMPONENT "cio"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/slab.h>
  19 #include <linux/list.h>
  20 #include <linux/device.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/delay.h>
  23 #include <linux/timer.h>
  24 #include <linux/kernel_stat.h>
  25
  26 #include <asm/ccwdev.h>
  27 #include <asm/cio.h>
  28 #include <asm/param.h>          /* HZ */
  29 #include <asm/cmb.h>
  30 #include <asm/isc.h>
  31
  32 #include "chp.h"
  33 #include "cio.h"
  34 #include "cio_debug.h"
  35 #include "css.h"
  36 #include "device.h"
  37 #include "ioasm.h"
  38 #include "io_sch.h"
  39 #include "blacklist.h"
  40 #include "chsc.h"
  41
  42 static struct timer_list recovery_timer;
  43 static DEFINE_SPINLOCK(recovery_lock);
  44 static int recovery_phase;
  45 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  46
  47 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
  48 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
  49 static struct bus_type ccw_bus_type;
  50
  51 /******************* bus type handling ***********************/
  52
  53 /* The Linux driver model distinguishes between a bus type and
  54  * the bus itself. Of course we only have one channel
  55  * subsystem driver and one channel system per machine, but
  56  * we still use the abstraction. T.R. says it's a good idea. */
  57 static int
  58 ccw_bus_match (struct device * dev, struct device_driver * drv)
  59 {
  60         struct ccw_device *cdev = to_ccwdev(dev);
  61         struct ccw_driver *cdrv = to_ccwdrv(drv);
  62         const struct ccw_device_id *ids = cdrv->ids, *found;
  63
  64         if (!ids)
  65                 return 0;
  66
  67         found = ccw_device_id_match(ids, &cdev->id);
  68         if (!found)
  69                 return 0;
  70
  71         cdev->id.driver_info = found->driver_info;
  72
  73         return 1;
  74 }
  75
  76 /* Store modalias string delimited by prefix/suffix string into buffer with
  77  * specified size. Return length of resulting string (excluding trailing '\0')
  78  * even if string doesn't fit buffer (snprintf semantics). */
  79 static int snprint_alias(char *buf, size_t size,
  80                          struct ccw_device_id *id, const char *suffix)
  81 {
  82         int len;
  83
  84         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  85         if (len > size)
  86                 return len;
  87         buf += len;
  88         size -= len;
  89
  90         if (id->dev_type != 0)
  91                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  92                                 id->dev_model, suffix);
  93         else
  94                 len += snprintf(buf, size, "dtdm%s", suffix);
  95
  96         return len;
  97 }
  98
  99 /* Set up environment variables for ccw device uevent. Return 0 on success,
 100  * non-zero otherwise. */
 101 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
 102 {
 103         struct ccw_device *cdev = to_ccwdev(dev);
 104         struct ccw_device_id *id = &(cdev->id);
 105         int ret;
 106         char modalias_buf[30];
 107
 108         /* CU_TYPE= */
 109         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 110         if (ret)
 111                 return ret;
 112
 113         /* CU_MODEL= */
 114         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 115         if (ret)
 116                 return ret;
 117
 118         /* The next two can be zero, that's ok for us */
 119         /* DEV_TYPE= */
 120         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 121         if (ret)
 122                 return ret;
 123
 124         /* DEV_MODEL= */
 125         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 126         if (ret)
 127                 return ret;
 128
 129         /* MODALIAS=  */
 130         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 131         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 132         return ret;
 133 }
 134
 135 static void io_subchannel_irq(struct subchannel *);
 136 static int io_subchannel_probe(struct subchannel *);
 137 static int io_subchannel_remove(struct subchannel *);
 138 static void io_subchannel_shutdown(struct subchannel *);
 139 static int io_subchannel_sch_event(struct subchannel *, int);
 140 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 141                                    int);
 142 static void recovery_func(unsigned long data);
 143
 144 static struct css_device_id io_subchannel_ids[] = {
 145         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 146         { /* end of list */ },
 147 };
 148 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 149
 150 static int io_subchannel_prepare(struct subchannel *sch)
 151 {
 152         struct ccw_device *cdev;
 153         /*
 154          * Don't allow suspend while a ccw device registration
 155          * is still outstanding.
 156          */
 157         cdev = sch_get_cdev(sch);
 158         if (cdev && !device_is_registered(&cdev->dev))
 159                 return -EAGAIN;
 160         return 0;
 161 }
 162
 163 static int io_subchannel_settle(void)
 164 {
 165         int ret;
 166
 167         ret = wait_event_interruptible(ccw_device_init_wq,
 168                                 atomic_read(&ccw_device_init_count) == 0);
 169         if (ret)
 170                 return -EINTR;
 171         flush_workqueue(cio_work_q);
 172         return 0;
 173 }
 174
 175 static struct css_driver io_subchannel_driver = {
 176         .drv = {
 177                 .owner = THIS_MODULE,
 178                 .name = "io_subchannel",
 179         },
 180         .subchannel_type = io_subchannel_ids,
 181         .irq = io_subchannel_irq,
 182         .sch_event = io_subchannel_sch_event,
 183         .chp_event = io_subchannel_chp_event,
 184         .probe = io_subchannel_probe,
 185         .remove = io_subchannel_remove,
 186         .shutdown = io_subchannel_shutdown,
 187         .prepare = io_subchannel_prepare,
 188         .settle = io_subchannel_settle,
 189 };
 190
 191 int __init io_subchannel_init(void)
 192 {
 193         int ret;
 194
 195         setup_timer(&recovery_timer, recovery_func, 0);
 196         ret = bus_register(&ccw_bus_type);
 197         if (ret)
 198                 return ret;
 199         ret = css_driver_register(&io_subchannel_driver);
 200         if (ret)
 201                 bus_unregister(&ccw_bus_type);
 202
 203         return ret;
 204 }
 205
 206
 207 /************************ device handling **************************/
 208
 209 /*
 210  * A ccw_device has some interfaces in sysfs in addition to the
 211  * standard ones.
 212  * The following entries are designed to export the information which
 213  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 214  * are obvious, so they don't have an entry :)
 215  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 216  */
 217 static ssize_t
 218 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 219 {
 220         struct subchannel *sch = to_subchannel(dev);
 221         struct chsc_ssd_info *ssd = &sch->ssd_info;
 222         ssize_t ret = 0;
 223         int chp;
 224         int mask;
 225
 226         for (chp = 0; chp < 8; chp++) {
 227                 mask = 0x80 >> chp;
 228                 if (ssd->path_mask & mask)
 229                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 230                 else
 231                         ret += sprintf(buf + ret, "00 ");
 232         }
 233         ret += sprintf (buf+ret, "\n");
 234         return min((ssize_t)PAGE_SIZE, ret);
 235 }
 236
 237 static ssize_t
 238 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 239 {
 240         struct subchannel *sch = to_subchannel(dev);
 241         struct pmcw *pmcw = &sch->schib.pmcw;
 242
 243         return sprintf (buf, "%02x %02x %02x\n",
 244                         pmcw->pim, pmcw->pam, pmcw->pom);
 245 }
 246
 247 static ssize_t
 248 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 249 {
 250         struct ccw_device *cdev = to_ccwdev(dev);
 251         struct ccw_device_id *id = &(cdev->id);
 252
 253         if (id->dev_type != 0)
 254                 return sprintf(buf, "%04x/%02x\n",
 255                                 id->dev_type, id->dev_model);
 256         else
 257                 return sprintf(buf, "n/a\n");
 258 }
 259
 260 static ssize_t
 261 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 262 {
 263         struct ccw_device *cdev = to_ccwdev(dev);
 264         struct ccw_device_id *id = &(cdev->id);
 265
 266         return sprintf(buf, "%04x/%02x\n",
 267                        id->cu_type, id->cu_model);
 268 }
 269
 270 static ssize_t
 271 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 272 {
 273         struct ccw_device *cdev = to_ccwdev(dev);
 274         struct ccw_device_id *id = &(cdev->id);
 275         int len;
 276
 277         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 278
 279         return len > PAGE_SIZE ? PAGE_SIZE : len;
 280 }
 281
 282 static ssize_t
 283 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 284 {
 285         struct ccw_device *cdev = to_ccwdev(dev);
 286
 287         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 288 }
 289
 290 int ccw_device_is_orphan(struct ccw_device *cdev)
 291 {
 292         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 293 }
 294
 295 static void ccw_device_unregister(struct ccw_device *cdev)
 296 {
 297         if (device_is_registered(&cdev->dev)) {
 298                 /* Undo device_add(). */
 299                 device_del(&cdev->dev);
 300         }
 301         if (cdev->private->flags.initialized) {
 302                 cdev->private->flags.initialized = 0;
 303                 /* Release reference from device_initialize(). */
 304                 put_device(&cdev->dev);
 305         }
 306 }
 307
 308 static void io_subchannel_quiesce(struct subchannel *);
 309
 310 /**
 311  * ccw_device_set_offline() - disable a ccw device for I/O
 312  * @cdev: target ccw device
 313  *
 314  * This function calls the driver's set_offline() function for @cdev, if
 315  * given, and then disables @cdev.
 316  * Returns:
 317  *   %0 on success and a negative error value on failure.
 318  * Context:
 319  *  enabled, ccw device lock not held
 320  */
 321 int ccw_device_set_offline(struct ccw_device *cdev)
 322 {
 323         struct subchannel *sch;
 324         int ret, state;
 325
 326         if (!cdev)
 327                 return -ENODEV;
 328         if (!cdev->online || !cdev->drv)
 329                 return -EINVAL;
 330
 331         if (cdev->drv->set_offline) {
 332                 ret = cdev->drv->set_offline(cdev);
 333                 if (ret != 0)
 334                         return ret;
 335         }
 336         spin_lock_irq(cdev->ccwlock);
 337         sch = to_subchannel(cdev->dev.parent);
 338         cdev->online = 0;
 339         /* Wait until a final state or DISCONNECTED is reached */
 340         while (!dev_fsm_final_state(cdev) &&
 341                cdev->private->state != DEV_STATE_DISCONNECTED) {
 342                 spin_unlock_irq(cdev->ccwlock);
 343                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 344                            cdev->private->state == DEV_STATE_DISCONNECTED));
 345                 spin_lock_irq(cdev->ccwlock);
 346         }
 347         do {
 348                 ret = ccw_device_offline(cdev);
 349                 if (!ret)
 350                         break;
 351                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 352                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 353                               cdev->private->dev_id.devno);
 354                 if (ret != -EBUSY)
 355                         goto error;
 356                 state = cdev->private->state;
 357                 spin_unlock_irq(cdev->ccwlock);
 358                 io_subchannel_quiesce(sch);
 359                 spin_lock_irq(cdev->ccwlock);
 360                 cdev->private->state = state;
 361         } while (ret == -EBUSY);
 362         spin_unlock_irq(cdev->ccwlock);
 363         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 364                    cdev->private->state == DEV_STATE_DISCONNECTED));
 365         /* Inform the user if set offline failed. */
 366         if (cdev->private->state == DEV_STATE_BOXED) {
 367                 pr_warning("%s: The device entered boxed state while "
 368                            "being set offline\n", dev_name(&cdev->dev));
 369         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 370                 pr_warning("%s: The device stopped operating while "
 371                            "being set offline\n", dev_name(&cdev->dev));
 372         }
 373         /* Give up reference from ccw_device_set_online(). */
 374         put_device(&cdev->dev);
 375         return 0;
 376
 377 error:
 378         cdev->private->state = DEV_STATE_OFFLINE;
 379         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 380         spin_unlock_irq(cdev->ccwlock);
 381         /* Give up reference from ccw_device_set_online(). */
 382         put_device(&cdev->dev);
 383         return -ENODEV;
 384 }
 385
 386 /**
 387  * ccw_device_set_online() - enable a ccw device for I/O
 388  * @cdev: target ccw device
 389  *
 390  * This function first enables @cdev and then calls the driver's set_online()
 391  * function for @cdev, if given. If set_online() returns an error, @cdev is
 392  * disabled again.
 393  * Returns:
 394  *   %0 on success and a negative error value on failure.
 395  * Context:
 396  *  enabled, ccw device lock not held
 397  */
 398 int ccw_device_set_online(struct ccw_device *cdev)
 399 {
 400         int ret;
 401         int ret2;
 402
 403         if (!cdev)
 404                 return -ENODEV;
 405         if (cdev->online || !cdev->drv)
 406                 return -EINVAL;
 407         /* Hold on to an extra reference while device is online. */
 408         if (!get_device(&cdev->dev))
 409                 return -ENODEV;
 410
 411         spin_lock_irq(cdev->ccwlock);
 412         ret = ccw_device_online(cdev);
 413         spin_unlock_irq(cdev->ccwlock);
 414         if (ret == 0)
 415                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 416         else {
 417                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 418                               "device 0.%x.%04x\n",
 419                               ret, cdev->private->dev_id.ssid,
 420                               cdev->private->dev_id.devno);
 421                 /* Give up online reference since onlining failed. */
 422                 put_device(&cdev->dev);
 423                 return ret;
 424         }
 425         spin_lock_irq(cdev->ccwlock);
 426         /* Check if online processing was successful */
 427         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 428             (cdev->private->state != DEV_STATE_W4SENSE)) {
 429                 spin_unlock_irq(cdev->ccwlock);
 430                 /* Inform the user that set online failed. */
 431                 if (cdev->private->state == DEV_STATE_BOXED) {
 432                         pr_warning("%s: Setting the device online failed "
 433                                    "because it is boxed\n",
 434                                    dev_name(&cdev->dev));
 435                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 436                         pr_warning("%s: Setting the device online failed "
 437                                    "because it is not operational\n",
 438                                    dev_name(&cdev->dev));
 439                 }
 440                 /* Give up online reference since onlining failed. */
 441                 put_device(&cdev->dev);
 442                 return -ENODEV;
 443         }
 444         spin_unlock_irq(cdev->ccwlock);
 445         if (cdev->drv->set_online)
 446                 ret = cdev->drv->set_online(cdev);
 447         if (ret)
 448                 goto rollback;
 449
 450         spin_lock_irq(cdev->ccwlock);
 451         cdev->online = 1;
 452         spin_unlock_irq(cdev->ccwlock);
 453         return 0;
 454
 455 rollback:
 456         spin_lock_irq(cdev->ccwlock);
 457         /* Wait until a final state or DISCONNECTED is reached */
 458         while (!dev_fsm_final_state(cdev) &&
 459                cdev->private->state != DEV_STATE_DISCONNECTED) {
 460                 spin_unlock_irq(cdev->ccwlock);
 461                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 462                            cdev->private->state == DEV_STATE_DISCONNECTED));
 463                 spin_lock_irq(cdev->ccwlock);
 464         }
 465         ret2 = ccw_device_offline(cdev);
 466         if (ret2)
 467                 goto error;
 468         spin_unlock_irq(cdev->ccwlock);
 469         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 470                    cdev->private->state == DEV_STATE_DISCONNECTED));
 471         /* Give up online reference since onlining failed. */
 472         put_device(&cdev->dev);
 473         return ret;
 474
 475 error:
 476         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 477                       "device 0.%x.%04x\n",
 478                       ret2, cdev->private->dev_id.ssid,
 479                       cdev->private->dev_id.devno);
 480         cdev->private->state = DEV_STATE_OFFLINE;
 481         spin_unlock_irq(cdev->ccwlock);
 482         /* Give up online reference since onlining failed. */
 483         put_device(&cdev->dev);
 484         return ret;
 485 }
 486
 487 static int online_store_handle_offline(struct ccw_device *cdev)
 488 {
 489         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 490                 spin_lock_irq(cdev->ccwlock);
 491                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 492                 spin_unlock_irq(cdev->ccwlock);
 493                 return 0;
 494         }
 495         if (cdev->drv && cdev->drv->set_offline)
 496                 return ccw_device_set_offline(cdev);
 497         return -EINVAL;
 498 }
 499
 500 static int online_store_recog_and_online(struct ccw_device *cdev)
 501 {
 502         /* Do device recognition, if needed. */
 503         if (cdev->private->state == DEV_STATE_BOXED) {
 504                 spin_lock_irq(cdev->ccwlock);
 505                 ccw_device_recognition(cdev);
 506                 spin_unlock_irq(cdev->ccwlock);
 507                 wait_event(cdev->private->wait_q,
 508                            cdev->private->flags.recog_done);
 509                 if (cdev->private->state != DEV_STATE_OFFLINE)
 510                         /* recognition failed */
 511                         return -EAGAIN;
 512         }
 513         if (cdev->drv && cdev->drv->set_online)
 514                 return ccw_device_set_online(cdev);
 515         return -EINVAL;
 516 }
 517
 518 static int online_store_handle_online(struct ccw_device *cdev, int force)
 519 {
 520         int ret;
 521
 522         ret = online_store_recog_and_online(cdev);
 523         if (ret && !force)
 524                 return ret;
 525         if (force && cdev->private->state == DEV_STATE_BOXED) {
 526                 ret = ccw_device_stlck(cdev);
 527                 if (ret)
 528                         return ret;
 529                 if (cdev->id.cu_type == 0)
 530                         cdev->private->state = DEV_STATE_NOT_OPER;
 531                 ret = online_store_recog_and_online(cdev);
 532                 if (ret)
 533                         return ret;
 534         }
 535         return 0;
 536 }
 537
 538 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 539                              const char *buf, size_t count)
 540 {
 541         struct ccw_device *cdev = to_ccwdev(dev);
 542         int force, ret;
 543         unsigned long i;
 544
 545         /* Prevent conflict between multiple on-/offline processing requests. */
 546         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 547                 return -EAGAIN;
 548         /* Prevent conflict between internal I/Os and on-/offline processing. */
 549         if (!dev_fsm_final_state(cdev) &&
 550             cdev->private->state != DEV_STATE_DISCONNECTED) {
 551                 ret = -EAGAIN;
 552                 goto out;
 553         }
 554         /* Prevent conflict between pending work and on-/offline processing.*/
 555         if (work_pending(&cdev->private->todo_work)) {
 556                 ret = -EAGAIN;
 557                 goto out;
 558         }
 559         if (!strncmp(buf, "force\n", count)) {
 560                 force = 1;
 561                 i = 1;
 562                 ret = 0;
 563         } else {
 564                 force = 0;
 565                 ret = kstrtoul(buf, 16, &i);
 566         }
 567         if (ret)
 568                 goto out;
 569
 570         device_lock(dev);
 571         switch (i) {
 572         case 0:
 573                 ret = online_store_handle_offline(cdev);
 574                 break;
 575         case 1:
 576                 ret = online_store_handle_online(cdev, force);
 577                 break;
 578         default:
 579                 ret = -EINVAL;
 580         }
 581         device_unlock(dev);
 582
 583 out:
 584         atomic_set(&cdev->private->onoff, 0);
 585         return (ret < 0) ? ret : count;
 586 }
 587
 588 static ssize_t
 589 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 590 {
 591         struct ccw_device *cdev = to_ccwdev(dev);
 592         struct subchannel *sch;
 593
 594         if (ccw_device_is_orphan(cdev))
 595                 return sprintf(buf, "no device\n");
 596         switch (cdev->private->state) {
 597         case DEV_STATE_BOXED:
 598                 return sprintf(buf, "boxed\n");
 599         case DEV_STATE_DISCONNECTED:
 600         case DEV_STATE_DISCONNECTED_SENSE_ID:
 601         case DEV_STATE_NOT_OPER:
 602                 sch = to_subchannel(dev->parent);
 603                 if (!sch->lpm)
 604                         return sprintf(buf, "no path\n");
 605                 else
 606                         return sprintf(buf, "no device\n");
 607         default:
 608                 /* All other states considered fine. */
 609                 return sprintf(buf, "good\n");
 610         }
 611 }
 612
 613 static ssize_t
 614 initiate_logging(struct device *dev, struct device_attribute *attr,
 615                  const char *buf, size_t count)
 616 {
 617         struct subchannel *sch = to_subchannel(dev);
 618         int rc;
 619
 620         rc = chsc_siosl(sch->schid);
 621         if (rc < 0) {
 622                 pr_warning("Logging for subchannel 0.%x.%04x failed with "
 623                            "errno=%d\n",
 624                            sch->schid.ssid, sch->schid.sch_no, rc);
 625                 return rc;
 626         }
 627         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 628                   sch->schid.ssid, sch->schid.sch_no);
 629         return count;
 630 }
 631
 632 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 633                         char *buf)
 634 {
 635         struct subchannel *sch = to_subchannel(dev);
 636
 637         return sprintf(buf, "%02x\n", sch->vpm);
 638 }
 639
 640 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 641 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 642 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 643 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 644 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 645 static DEVICE_ATTR(online, 0644, online_show, online_store);
 646 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 647 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 648 static DEVICE_ATTR(vpm, 0444, vpm_show, NULL);
 649
 650 static struct attribute *io_subchannel_attrs[] = {
 651         &dev_attr_chpids.attr,
 652         &dev_attr_pimpampom.attr,
 653         &dev_attr_logging.attr,
 654         &dev_attr_vpm.attr,
 655         NULL,
 656 };
 657
 658 static struct attribute_group io_subchannel_attr_group = {
 659         .attrs = io_subchannel_attrs,
 660 };
 661
 662 static struct attribute * ccwdev_attrs[] = {
 663         &dev_attr_devtype.attr,
 664         &dev_attr_cutype.attr,
 665         &dev_attr_modalias.attr,
 666         &dev_attr_online.attr,
 667         &dev_attr_cmb_enable.attr,
 668         &dev_attr_availability.attr,
 669         NULL,
 670 };
 671
 672 static struct attribute_group ccwdev_attr_group = {
 673         .attrs = ccwdev_attrs,
 674 };
 675
 676 static const struct attribute_group *ccwdev_attr_groups[] = {
 677         &ccwdev_attr_group,
 678         NULL,
 679 };
 680
 681 /* this is a simple abstraction for device_register that sets the
 682  * correct bus type and adds the bus specific files */
 683 static int ccw_device_register(struct ccw_device *cdev)
 684 {
 685         struct device *dev = &cdev->dev;
 686         int ret;
 687
 688         dev->bus = &ccw_bus_type;
 689         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 690                            cdev->private->dev_id.devno);
 691         if (ret)
 692                 return ret;
 693         return device_add(dev);
 694 }
 695
 696 static int match_dev_id(struct device *dev, void *data)
 697 {
 698         struct ccw_device *cdev = to_ccwdev(dev);
 699         struct ccw_dev_id *dev_id = data;
 700
 701         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 702 }
 703
 704 /**
 705  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 706  * @dev_id: id of the device to be searched
 707  *
 708  * This function searches all devices attached to the ccw bus for a device
 709  * matching @dev_id.
 710  * Returns:
 711  *  If a device is found its reference count is increased and returned;
 712  *  else %NULL is returned.
 713  */
 714 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 715 {
 716         struct device *dev;
 717
 718         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 719
 720         return dev ? to_ccwdev(dev) : NULL;
 721 }
 722 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 723
 724 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 725 {
 726         int ret;
 727
 728         if (device_is_registered(&cdev->dev)) {
 729                 device_release_driver(&cdev->dev);
 730                 ret = device_attach(&cdev->dev);
 731                 WARN_ON(ret == -ENODEV);
 732         }
 733 }
 734
 735 static void
 736 ccw_device_release(struct device *dev)
 737 {
 738         struct ccw_device *cdev;
 739
 740         cdev = to_ccwdev(dev);
 741         /* Release reference of parent subchannel. */
 742         put_device(cdev->dev.parent);
 743         kfree(cdev->private);
 744         kfree(cdev);
 745 }
 746
 747 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 748 {
 749         struct ccw_device *cdev;
 750
 751         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 752         if (cdev) {
 753                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 754                                         GFP_KERNEL | GFP_DMA);
 755                 if (cdev->private)
 756                         return cdev;
 757         }
 758         kfree(cdev);
 759         return ERR_PTR(-ENOMEM);
 760 }
 761
 762 static void ccw_device_todo(struct work_struct *work);
 763
 764 static int io_subchannel_initialize_dev(struct subchannel *sch,
 765                                         struct ccw_device *cdev)
 766 {
 767         cdev->private->cdev = cdev;
 768         cdev->private->int_class = IRQIO_CIO;
 769         atomic_set(&cdev->private->onoff, 0);
 770         cdev->dev.parent = &sch->dev;
 771         cdev->dev.release = ccw_device_release;
 772         INIT_WORK(&cdev->private->todo_work, ccw_device_todo);
 773         cdev->dev.groups = ccwdev_attr_groups;
 774         /* Do first half of device_register. */
 775         device_initialize(&cdev->dev);
 776         if (!get_device(&sch->dev)) {
 777                 /* Release reference from device_initialize(). */
 778                 put_device(&cdev->dev);
 779                 return -ENODEV;
 780         }
 781         cdev->private->flags.initialized = 1;
 782         return 0;
 783 }
 784
 785 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 786 {
 787         struct ccw_device *cdev;
 788         int ret;
 789
 790         cdev = io_subchannel_allocate_dev(sch);
 791         if (!IS_ERR(cdev)) {
 792                 ret = io_subchannel_initialize_dev(sch, cdev);
 793                 if (ret)
 794                         cdev = ERR_PTR(ret);
 795         }
 796         return cdev;
 797 }
 798
 799 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 800
 801 static void sch_create_and_recog_new_device(struct subchannel *sch)
 802 {
 803         struct ccw_device *cdev;
 804
 805         /* Need to allocate a new ccw device. */
 806         cdev = io_subchannel_create_ccwdev(sch);
 807         if (IS_ERR(cdev)) {
 808                 /* OK, we did everything we could... */
 809                 css_sch_device_unregister(sch);
 810                 return;
 811         }
 812         /* Start recognition for the new ccw device. */
 813         io_subchannel_recog(cdev, sch);
 814 }
 815
 816 /*
 817  * Register recognized device.
 818  */
 819 static void io_subchannel_register(struct ccw_device *cdev)
 820 {
 821         struct subchannel *sch;
 822         int ret, adjust_init_count = 1;
 823         unsigned long flags;
 824
 825         sch = to_subchannel(cdev->dev.parent);
 826         /*
 827          * Check if subchannel is still registered. It may have become
 828          * unregistered if a machine check hit us after finishing
 829          * device recognition but before the register work could be
 830          * queued.
 831          */
 832         if (!device_is_registered(&sch->dev))
 833                 goto out_err;
 834         css_update_ssd_info(sch);
 835         /*
 836          * io_subchannel_register() will also be called after device
 837          * recognition has been done for a boxed device (which will already
 838          * be registered). We need to reprobe since we may now have sense id
 839          * information.
 840          */
 841         if (device_is_registered(&cdev->dev)) {
 842                 if (!cdev->drv) {
 843                         ret = device_reprobe(&cdev->dev);
 844                         if (ret)
 845                                 /* We can't do much here. */
 846                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 847                                               " %d for 0.%x.%04x\n", ret,
 848                                               cdev->private->dev_id.ssid,
 849                                               cdev->private->dev_id.devno);
 850                 }
 851                 adjust_init_count = 0;
 852                 goto out;
 853         }
 854         /*
 855          * Now we know this subchannel will stay, we can throw
 856          * our delayed uevent.
 857          */
 858         dev_set_uevent_suppress(&sch->dev, 0);
 859         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 860         /* make it known to the system */
 861         ret = ccw_device_register(cdev);
 862         if (ret) {
 863                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 864                               cdev->private->dev_id.ssid,
 865                               cdev->private->dev_id.devno, ret);
 866                 spin_lock_irqsave(sch->lock, flags);
 867                 sch_set_cdev(sch, NULL);
 868                 spin_unlock_irqrestore(sch->lock, flags);
 869                 /* Release initial device reference. */
 870                 put_device(&cdev->dev);
 871                 goto out_err;
 872         }
 873 out:
 874         cdev->private->flags.recog_done = 1;
 875         wake_up(&cdev->private->wait_q);
 876 out_err:
 877         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 878                 wake_up(&ccw_device_init_wq);
 879 }
 880
 881 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 882 {
 883         struct subchannel *sch;
 884
 885         /* Get subchannel reference for local processing. */
 886         if (!get_device(cdev->dev.parent))
 887                 return;
 888         sch = to_subchannel(cdev->dev.parent);
 889         css_sch_device_unregister(sch);
 890         /* Release subchannel reference for local processing. */
 891         put_device(&sch->dev);
 892 }
 893
 894 /*
 895  * subchannel recognition done. Called from the state machine.
 896  */
 897 void
 898 io_subchannel_recog_done(struct ccw_device *cdev)
 899 {
 900         if (css_init_done == 0) {
 901                 cdev->private->flags.recog_done = 1;
 902                 return;
 903         }
 904         switch (cdev->private->state) {
 905         case DEV_STATE_BOXED:
 906                 /* Device did not respond in time. */
 907         case DEV_STATE_NOT_OPER:
 908                 cdev->private->flags.recog_done = 1;
 909                 /* Remove device found not operational. */
 910                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 911                 if (atomic_dec_and_test(&ccw_device_init_count))
 912                         wake_up(&ccw_device_init_wq);
 913                 break;
 914         case DEV_STATE_OFFLINE:
 915                 /*
 916                  * We can't register the device in interrupt context so
 917                  * we schedule a work item.
 918                  */
 919                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 920                 break;
 921         }
 922 }
 923
 924 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 925 {
 926         struct ccw_device_private *priv;
 927
 928         cdev->ccwlock = sch->lock;
 929
 930         /* Init private data. */
 931         priv = cdev->private;
 932         priv->dev_id.devno = sch->schib.pmcw.dev;
 933         priv->dev_id.ssid = sch->schid.ssid;
 934         priv->schid = sch->schid;
 935         priv->state = DEV_STATE_NOT_OPER;
 936         INIT_LIST_HEAD(&priv->cmb_list);
 937         init_waitqueue_head(&priv->wait_q);
 938         init_timer(&priv->timer);
 939
 940         /* Increase counter of devices currently in recognition. */
 941         atomic_inc(&ccw_device_init_count);
 942
 943         /* Start async. device sensing. */
 944         spin_lock_irq(sch->lock);
 945         sch_set_cdev(sch, cdev);
 946         ccw_device_recognition(cdev);
 947         spin_unlock_irq(sch->lock);
 948 }
 949
 950 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 951                                   struct subchannel *sch)
 952 {
 953         struct subchannel *old_sch;
 954         int rc, old_enabled = 0;
 955
 956         old_sch = to_subchannel(cdev->dev.parent);
 957         /* Obtain child reference for new parent. */
 958         if (!get_device(&sch->dev))
 959                 return -ENODEV;
 960
 961         if (!sch_is_pseudo_sch(old_sch)) {
 962                 spin_lock_irq(old_sch->lock);
 963                 old_enabled = old_sch->schib.pmcw.ena;
 964                 rc = 0;
 965                 if (old_enabled)
 966                         rc = cio_disable_subchannel(old_sch);
 967                 spin_unlock_irq(old_sch->lock);
 968                 if (rc == -EBUSY) {
 969                         /* Release child reference for new parent. */
 970                         put_device(&sch->dev);
 971                         return rc;
 972                 }
 973         }
 974
 975         mutex_lock(&sch->reg_mutex);
 976         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 977         mutex_unlock(&sch->reg_mutex);
 978         if (rc) {
 979                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 980                               cdev->private->dev_id.ssid,
 981                               cdev->private->dev_id.devno, sch->schid.ssid,
 982                               sch->schib.pmcw.dev, rc);
 983                 if (old_enabled) {
 984                         /* Try to reenable the old subchannel. */
 985                         spin_lock_irq(old_sch->lock);
 986                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 987                         spin_unlock_irq(old_sch->lock);
 988                 }
 989                 /* Release child reference for new parent. */
 990                 put_device(&sch->dev);
 991                 return rc;
 992         }
 993         /* Clean up old subchannel. */
 994         if (!sch_is_pseudo_sch(old_sch)) {
 995                 spin_lock_irq(old_sch->lock);
 996                 sch_set_cdev(old_sch, NULL);
 997                 spin_unlock_irq(old_sch->lock);
 998                 css_schedule_eval(old_sch->schid);
 999         }
1000         /* Release child reference for old parent. */
1001         put_device(&old_sch->dev);
1002         /* Initialize new subchannel. */
1003         spin_lock_irq(sch->lock);
1004         cdev->private->schid = sch->schid;
1005         cdev->ccwlock = sch->lock;
1006         if (!sch_is_pseudo_sch(sch))
1007                 sch_set_cdev(sch, cdev);
1008         spin_unlock_irq(sch->lock);
1009         if (!sch_is_pseudo_sch(sch))
1010                 css_update_ssd_info(sch);
1011         return 0;
1012 }
1013
1014 static int ccw_device_move_to_orph(struct ccw_device *cdev)
1015 {
1016         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1017         struct channel_subsystem *css = to_css(sch->dev.parent);
1018
1019         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
1020 }
1021
1022 static void io_subchannel_irq(struct subchannel *sch)
1023 {
1024         struct ccw_device *cdev;
1025
1026         cdev = sch_get_cdev(sch);
1027
1028         CIO_TRACE_EVENT(6, "IRQ");
1029         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1030         if (cdev)
1031                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1032         else
1033                 inc_irq_stat(IRQIO_CIO);
1034 }
1035
1036 void io_subchannel_init_config(struct subchannel *sch)
1037 {
1038         memset(&sch->config, 0, sizeof(sch->config));
1039         sch->config.csense = 1;
1040 }
1041
1042 static void io_subchannel_init_fields(struct subchannel *sch)
1043 {
1044         if (cio_is_console(sch->schid))
1045                 sch->opm = 0xff;
1046         else
1047                 sch->opm = chp_get_sch_opm(sch);
1048         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1049         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1050
1051         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1052                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1053                       sch->schib.pmcw.dev, sch->schid.ssid,
1054                       sch->schid.sch_no, sch->schib.pmcw.pim,
1055                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1056
1057         io_subchannel_init_config(sch);
1058 }
1059
1060 /*
1061  * Note: We always return 0 so that we bind to the device even on error.
1062  * This is needed so that our remove function is called on unregister.
1063  */
1064 static int io_subchannel_probe(struct subchannel *sch)
1065 {
1066         struct io_subchannel_private *io_priv;
1067         struct ccw_device *cdev;
1068         int rc;
1069
1070         if (cio_is_console(sch->schid)) {
1071                 rc = sysfs_create_group(&sch->dev.kobj,
1072                                         &io_subchannel_attr_group);
1073                 if (rc)
1074                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1075                                       "attributes for subchannel "
1076                                       "0.%x.%04x (rc=%d)\n",
1077                                       sch->schid.ssid, sch->schid.sch_no, rc);
1078                 /*
1079                  * The console subchannel already has an associated ccw_device.
1080                  * Throw the delayed uevent for the subchannel, register
1081                  * the ccw_device and exit.
1082                  */
1083                 dev_set_uevent_suppress(&sch->dev, 0);
1084                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1085                 cdev = sch_get_cdev(sch);
1086                 rc = ccw_device_register(cdev);
1087                 if (rc) {
1088                         /* Release online reference. */
1089                         put_device(&cdev->dev);
1090                         goto out_schedule;
1091                 }
1092                 if (atomic_dec_and_test(&ccw_device_init_count))
1093                         wake_up(&ccw_device_init_wq);
1094                 return 0;
1095         }
1096         io_subchannel_init_fields(sch);
1097         rc = cio_commit_config(sch);
1098         if (rc)
1099                 goto out_schedule;
1100         rc = sysfs_create_group(&sch->dev.kobj,
1101                                 &io_subchannel_attr_group);
1102         if (rc)
1103                 goto out_schedule;
1104         /* Allocate I/O subchannel private data. */
1105         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1106         if (!io_priv)
1107                 goto out_schedule;
1108
1109         set_io_private(sch, io_priv);
1110         css_schedule_eval(sch->schid);
1111         return 0;
1112
1113 out_schedule:
1114         spin_lock_irq(sch->lock);
1115         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1116         spin_unlock_irq(sch->lock);
1117         return 0;
1118 }
1119
1120 static int
1121 io_subchannel_remove (struct subchannel *sch)
1122 {
1123         struct io_subchannel_private *io_priv = to_io_private(sch);
1124         struct ccw_device *cdev;
1125
1126         cdev = sch_get_cdev(sch);
1127         if (!cdev)
1128                 goto out_free;
1129         io_subchannel_quiesce(sch);
1130         /* Set ccw device to not operational and drop reference. */
1131         spin_lock_irq(cdev->ccwlock);
1132         sch_set_cdev(sch, NULL);
1133         set_io_private(sch, NULL);
1134         cdev->private->state = DEV_STATE_NOT_OPER;
1135         spin_unlock_irq(cdev->ccwlock);
1136         ccw_device_unregister(cdev);
1137 out_free:
1138         kfree(io_priv);
1139         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1140         return 0;
1141 }
1142
1143 static void io_subchannel_verify(struct subchannel *sch)
1144 {
1145         struct ccw_device *cdev;
1146
1147         cdev = sch_get_cdev(sch);
1148         if (cdev)
1149                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1150 }
1151
1152 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1153 {
1154         struct ccw_device *cdev;
1155
1156         cdev = sch_get_cdev(sch);
1157         if (!cdev)
1158                 return;
1159         if (cio_update_schib(sch))
1160                 goto err;
1161         /* Check for I/O on path. */
1162         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1163                 goto out;
1164         if (cdev->private->state == DEV_STATE_ONLINE) {
1165                 ccw_device_kill_io(cdev);
1166                 goto out;
1167         }
1168         if (cio_clear(sch))
1169                 goto err;
1170 out:
1171         /* Trigger path verification. */
1172         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1173         return;
1174
1175 err:
1176         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1177 }
1178
1179 static int io_subchannel_chp_event(struct subchannel *sch,
1180                                    struct chp_link *link, int event)
1181 {
1182         struct ccw_device *cdev = sch_get_cdev(sch);
1183         int mask;
1184
1185         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1186         if (!mask)
1187                 return 0;
1188         switch (event) {
1189         case CHP_VARY_OFF:
1190                 sch->opm &= ~mask;
1191                 sch->lpm &= ~mask;
1192                 if (cdev)
1193                         cdev->private->path_gone_mask |= mask;
1194                 io_subchannel_terminate_path(sch, mask);
1195                 break;
1196         case CHP_VARY_ON:
1197                 sch->opm |= mask;
1198                 sch->lpm |= mask;
1199                 if (cdev)
1200                         cdev->private->path_new_mask |= mask;
1201                 io_subchannel_verify(sch);
1202                 break;
1203         case CHP_OFFLINE:
1204                 if (cio_update_schib(sch))
1205                         return -ENODEV;
1206                 if (cdev)
1207                         cdev->private->path_gone_mask |= mask;
1208                 io_subchannel_terminate_path(sch, mask);
1209                 break;
1210         case CHP_ONLINE:
1211                 if (cio_update_schib(sch))
1212                         return -ENODEV;
1213                 sch->lpm |= mask & sch->opm;
1214                 if (cdev)
1215                         cdev->private->path_new_mask |= mask;
1216                 io_subchannel_verify(sch);
1217                 break;
1218         }
1219         return 0;
1220 }
1221
1222 static void io_subchannel_quiesce(struct subchannel *sch)
1223 {
1224         struct ccw_device *cdev;
1225         int ret;
1226
1227         spin_lock_irq(sch->lock);
1228         cdev = sch_get_cdev(sch);
1229         if (cio_is_console(sch->schid))
1230                 goto out_unlock;
1231         if (!sch->schib.pmcw.ena)
1232                 goto out_unlock;
1233         ret = cio_disable_subchannel(sch);
1234         if (ret != -EBUSY)
1235                 goto out_unlock;
1236         if (cdev->handler)
1237                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1238         while (ret == -EBUSY) {
1239                 cdev->private->state = DEV_STATE_QUIESCE;
1240                 cdev->private->iretry = 255;
1241                 ret = ccw_device_cancel_halt_clear(cdev);
1242                 if (ret == -EBUSY) {
1243                         ccw_device_set_timeout(cdev, HZ/10);
1244                         spin_unlock_irq(sch->lock);
1245                         wait_event(cdev->private->wait_q,
1246                                    cdev->private->state != DEV_STATE_QUIESCE);
1247                         spin_lock_irq(sch->lock);
1248                 }
1249                 ret = cio_disable_subchannel(sch);
1250         }
1251 out_unlock:
1252         spin_unlock_irq(sch->lock);
1253 }
1254
1255 static void io_subchannel_shutdown(struct subchannel *sch)
1256 {
1257         io_subchannel_quiesce(sch);
1258 }
1259
1260 static int device_is_disconnected(struct ccw_device *cdev)
1261 {
1262         if (!cdev)
1263                 return 0;
1264         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1265                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1266 }
1267
1268 static int recovery_check(struct device *dev, void *data)
1269 {
1270         struct ccw_device *cdev = to_ccwdev(dev);
1271         int *redo = data;
1272
1273         spin_lock_irq(cdev->ccwlock);
1274         switch (cdev->private->state) {
1275         case DEV_STATE_DISCONNECTED:
1276                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1277                               cdev->private->dev_id.ssid,
1278                               cdev->private->dev_id.devno);
1279                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1280                 *redo = 1;
1281                 break;
1282         case DEV_STATE_DISCONNECTED_SENSE_ID:
1283                 *redo = 1;
1284                 break;
1285         }
1286         spin_unlock_irq(cdev->ccwlock);
1287
1288         return 0;
1289 }
1290
1291 static void recovery_work_func(struct work_struct *unused)
1292 {
1293         int redo = 0;
1294
1295         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1296         if (redo) {
1297                 spin_lock_irq(&recovery_lock);
1298                 if (!timer_pending(&recovery_timer)) {
1299                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1300                                 recovery_phase++;
1301                         mod_timer(&recovery_timer, jiffies +
1302                                   recovery_delay[recovery_phase] * HZ);
1303                 }
1304                 spin_unlock_irq(&recovery_lock);
1305         } else
1306                 CIO_MSG_EVENT(4, "recovery: end\n");
1307 }
1308
1309 static DECLARE_WORK(recovery_work, recovery_work_func);
1310
1311 static void recovery_func(unsigned long data)
1312 {
1313         /*
1314          * We can't do our recovery in softirq context and it's not
1315          * performance critical, so we schedule it.
1316          */
1317         schedule_work(&recovery_work);
1318 }
1319
1320 static void ccw_device_schedule_recovery(void)
1321 {
1322         unsigned long flags;
1323
1324         CIO_MSG_EVENT(4, "recovery: schedule\n");
1325         spin_lock_irqsave(&recovery_lock, flags);
1326         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1327                 recovery_phase = 0;
1328                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1329         }
1330         spin_unlock_irqrestore(&recovery_lock, flags);
1331 }
1332
1333 static int purge_fn(struct device *dev, void *data)
1334 {
1335         struct ccw_device *cdev = to_ccwdev(dev);
1336         struct ccw_dev_id *id = &cdev->private->dev_id;
1337
1338         spin_lock_irq(cdev->ccwlock);
1339         if (is_blacklisted(id->ssid, id->devno) &&
1340             (cdev->private->state == DEV_STATE_OFFLINE) &&
1341             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1342                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1343                               id->devno);
1344                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1345                 atomic_set(&cdev->private->onoff, 0);
1346         }
1347         spin_unlock_irq(cdev->ccwlock);
1348         /* Abort loop in case of pending signal. */
1349         if (signal_pending(current))
1350                 return -EINTR;
1351
1352         return 0;
1353 }
1354
1355 /**
1356  * ccw_purge_blacklisted - purge unused, blacklisted devices
1357  *
1358  * Unregister all ccw devices that are offline and on the blacklist.
1359  */
1360 int ccw_purge_blacklisted(void)
1361 {
1362         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1363         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1364         return 0;
1365 }
1366
1367 void ccw_device_set_disconnected(struct ccw_device *cdev)
1368 {
1369         if (!cdev)
1370                 return;
1371         ccw_device_set_timeout(cdev, 0);
1372         cdev->private->flags.fake_irb = 0;
1373         cdev->private->state = DEV_STATE_DISCONNECTED;
1374         if (cdev->online)
1375                 ccw_device_schedule_recovery();
1376 }
1377
1378 void ccw_device_set_notoper(struct ccw_device *cdev)
1379 {
1380         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1381
1382         CIO_TRACE_EVENT(2, "notoper");
1383         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1384         ccw_device_set_timeout(cdev, 0);
1385         cio_disable_subchannel(sch);
1386         cdev->private->state = DEV_STATE_NOT_OPER;
1387 }
1388
1389 enum io_sch_action {
1390         IO_SCH_UNREG,
1391         IO_SCH_ORPH_UNREG,
1392         IO_SCH_ATTACH,
1393         IO_SCH_UNREG_ATTACH,
1394         IO_SCH_ORPH_ATTACH,
1395         IO_SCH_REPROBE,
1396         IO_SCH_VERIFY,
1397         IO_SCH_DISC,
1398         IO_SCH_NOP,
1399 };
1400
1401 static enum io_sch_action sch_get_action(struct subchannel *sch)
1402 {
1403         struct ccw_device *cdev;
1404
1405         cdev = sch_get_cdev(sch);
1406         if (cio_update_schib(sch)) {
1407                 /* Not operational. */
1408                 if (!cdev)
1409                         return IO_SCH_UNREG;
1410                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1411                         return IO_SCH_UNREG;
1412                 return IO_SCH_ORPH_UNREG;
1413         }
1414         /* Operational. */
1415         if (!cdev)
1416                 return IO_SCH_ATTACH;
1417         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1418                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1419                         return IO_SCH_UNREG_ATTACH;
1420                 return IO_SCH_ORPH_ATTACH;
1421         }
1422         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1423                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1424                         return IO_SCH_UNREG;
1425                 return IO_SCH_DISC;
1426         }
1427         if (device_is_disconnected(cdev))
1428                 return IO_SCH_REPROBE;
1429         if (cdev->online && !cdev->private->flags.resuming)
1430                 return IO_SCH_VERIFY;
1431         if (cdev->private->state == DEV_STATE_NOT_OPER)
1432                 return IO_SCH_UNREG_ATTACH;
1433         return IO_SCH_NOP;
1434 }
1435
1436 /**
1437  * io_subchannel_sch_event - process subchannel event
1438  * @sch: subchannel
1439  * @process: non-zero if function is called in process context
1440  *
1441  * An unspecified event occurred for this subchannel. Adjust data according
1442  * to the current operational state of the subchannel and device. Return
1443  * zero when the event has been handled sufficiently or -EAGAIN when this
1444  * function should be called again in process context.
1445  */
1446 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1447 {
1448         unsigned long flags;
1449         struct ccw_device *cdev;
1450         struct ccw_dev_id dev_id;
1451         enum io_sch_action action;
1452         int rc = -EAGAIN;
1453
1454         spin_lock_irqsave(sch->lock, flags);
1455         if (!device_is_registered(&sch->dev))
1456                 goto out_unlock;
1457         if (work_pending(&sch->todo_work))
1458                 goto out_unlock;
1459         cdev = sch_get_cdev(sch);
1460         if (cdev && work_pending(&cdev->private->todo_work))
1461                 goto out_unlock;
1462         action = sch_get_action(sch);
1463         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1464                       sch->schid.ssid, sch->schid.sch_no, process,
1465                       action);
1466         /* Perform immediate actions while holding the lock. */
1467         switch (action) {
1468         case IO_SCH_REPROBE:
1469                 /* Trigger device recognition. */
1470                 ccw_device_trigger_reprobe(cdev);
1471                 rc = 0;
1472                 goto out_unlock;
1473         case IO_SCH_VERIFY:
1474                 /* Trigger path verification. */
1475                 io_subchannel_verify(sch);
1476                 rc = 0;
1477                 goto out_unlock;
1478         case IO_SCH_DISC:
1479                 ccw_device_set_disconnected(cdev);
1480                 rc = 0;
1481                 goto out_unlock;
1482         case IO_SCH_ORPH_UNREG:
1483         case IO_SCH_ORPH_ATTACH:
1484                 ccw_device_set_disconnected(cdev);
1485                 break;
1486         case IO_SCH_UNREG_ATTACH:
1487         case IO_SCH_UNREG:
1488                 if (!cdev)
1489                         break;
1490                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1491                         /*
1492                          * Note: delayed work triggered by this event
1493                          * and repeated calls to sch_event are synchronized
1494                          * by the above check for work_pending(cdev).
1495                          */
1496                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1497                 } else
1498                         ccw_device_set_notoper(cdev);
1499                 break;
1500         case IO_SCH_NOP:
1501                 rc = 0;
1502                 goto out_unlock;
1503         default:
1504                 break;
1505         }
1506         spin_unlock_irqrestore(sch->lock, flags);
1507         /* All other actions require process context. */
1508         if (!process)
1509                 goto out;
1510         /* Handle attached ccw device. */
1511         switch (action) {
1512         case IO_SCH_ORPH_UNREG:
1513         case IO_SCH_ORPH_ATTACH:
1514                 /* Move ccw device to orphanage. */
1515                 rc = ccw_device_move_to_orph(cdev);
1516                 if (rc)
1517                         goto out;
1518                 break;
1519         case IO_SCH_UNREG_ATTACH:
1520                 spin_lock_irqsave(sch->lock, flags);
1521                 if (cdev->private->flags.resuming) {
1522                         /* Device will be handled later. */
1523                         rc = 0;
1524                         goto out_unlock;
1525                 }
1526                 sch_set_cdev(sch, NULL);
1527                 spin_unlock_irqrestore(sch->lock, flags);
1528                 /* Unregister ccw device. */
1529                 ccw_device_unregister(cdev);
1530                 break;
1531         default:
1532                 break;
1533         }
1534         /* Handle subchannel. */
1535         switch (action) {
1536         case IO_SCH_ORPH_UNREG:
1537         case IO_SCH_UNREG:
1538                 if (!cdev || !cdev->private->flags.resuming)
1539                         css_sch_device_unregister(sch);
1540                 break;
1541         case IO_SCH_ORPH_ATTACH:
1542         case IO_SCH_UNREG_ATTACH:
1543         case IO_SCH_ATTACH:
1544                 dev_id.ssid = sch->schid.ssid;
1545                 dev_id.devno = sch->schib.pmcw.dev;
1546                 cdev = get_ccwdev_by_dev_id(&dev_id);
1547                 if (!cdev) {
1548                         sch_create_and_recog_new_device(sch);
1549                         break;
1550                 }
1551                 rc = ccw_device_move_to_sch(cdev, sch);
1552                 if (rc) {
1553                         /* Release reference from get_ccwdev_by_dev_id() */
1554                         put_device(&cdev->dev);
1555                         goto out;
1556                 }
1557                 spin_lock_irqsave(sch->lock, flags);
1558                 ccw_device_trigger_reprobe(cdev);
1559                 spin_unlock_irqrestore(sch->lock, flags);
1560                 /* Release reference from get_ccwdev_by_dev_id() */
1561                 put_device(&cdev->dev);
1562                 break;
1563         default:
1564                 break;
1565         }
1566         return 0;
1567
1568 out_unlock:
1569         spin_unlock_irqrestore(sch->lock, flags);
1570 out:
1571         return rc;
1572 }
1573
1574 #ifdef CONFIG_CCW_CONSOLE
1575 static int ccw_device_console_enable(struct ccw_device *cdev,
1576                                      struct subchannel *sch)
1577 {
1578         int rc;
1579
1580         io_subchannel_init_fields(sch);
1581         rc = cio_commit_config(sch);
1582         if (rc)
1583                 return rc;
1584         sch->driver = &io_subchannel_driver;
1585         sch_set_cdev(sch, cdev);
1586         io_subchannel_recog(cdev, sch);
1587         /* Now wait for the async. recognition to come to an end. */
1588         spin_lock_irq(cdev->ccwlock);
1589         while (!dev_fsm_final_state(cdev))
1590                 ccw_device_wait_idle(cdev);
1591
1592         /* Hold on to an extra reference while device is online. */
1593         get_device(&cdev->dev);
1594         rc = ccw_device_online(cdev);
1595         if (rc)
1596                 goto out_unlock;
1597
1598         while (!dev_fsm_final_state(cdev))
1599                 ccw_device_wait_idle(cdev);
1600
1601         if (cdev->private->state == DEV_STATE_ONLINE)
1602                 cdev->online = 1;
1603         else
1604                 rc = -EIO;
1605 out_unlock:
1606         spin_unlock_irq(cdev->ccwlock);
1607         if (rc) /* Give up online reference since onlining failed. */
1608                 put_device(&cdev->dev);
1609         return rc;
1610 }
1611
1612 struct ccw_device *ccw_device_probe_console(void)
1613 {
1614         struct io_subchannel_private *io_priv;
1615         struct ccw_device *cdev;
1616         struct subchannel *sch;
1617         int ret;
1618
1619         sch = cio_probe_console();
1620         if (IS_ERR(sch))
1621                 return ERR_CAST(sch);
1622
1623         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1624         if (!io_priv) {
1625                 put_device(&sch->dev);
1626                 return ERR_PTR(-ENOMEM);
1627         }
1628         cdev = io_subchannel_create_ccwdev(sch);
1629         if (IS_ERR(cdev)) {
1630                 put_device(&sch->dev);
1631                 kfree(io_priv);
1632                 return cdev;
1633         }
1634         set_io_private(sch, io_priv);
1635         ret = ccw_device_console_enable(cdev, sch);
1636         if (ret) {
1637                 set_io_private(sch, NULL);
1638                 put_device(&sch->dev);
1639                 put_device(&cdev->dev);
1640                 kfree(io_priv);
1641                 return ERR_PTR(ret);
1642         }
1643         return cdev;
1644 }
1645
1646 /**
1647  * ccw_device_wait_idle() - busy wait for device to become idle
1648  * @cdev: ccw device
1649  *
1650  * Poll until activity control is zero, that is, no function or data
1651  * transfer is pending/active.
1652  * Called with device lock being held.
1653  */
1654 void ccw_device_wait_idle(struct ccw_device *cdev)
1655 {
1656         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1657
1658         while (1) {
1659                 cio_tsch(sch);
1660                 if (sch->schib.scsw.cmd.actl == 0)
1661                         break;
1662                 udelay_simple(100);
1663         }
1664 }
1665
1666 static int ccw_device_pm_restore(struct device *dev);
1667
1668 int ccw_device_force_console(struct ccw_device *cdev)
1669 {
1670         return ccw_device_pm_restore(&cdev->dev);
1671 }
1672 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1673 #endif
1674
1675 /*
1676  * get ccw_device matching the busid, but only if owned by cdrv
1677  */
1678 static int
1679 __ccwdev_check_busid(struct device *dev, void *id)
1680 {
1681         char *bus_id;
1682
1683         bus_id = id;
1684
1685         return (strcmp(bus_id, dev_name(dev)) == 0);
1686 }
1687
1688
1689 /**
1690  * get_ccwdev_by_busid() - obtain device from a bus id
1691  * @cdrv: driver the device is owned by
1692  * @bus_id: bus id of the device to be searched
1693  *
1694  * This function searches all devices owned by @cdrv for a device with a bus
1695  * id matching @bus_id.
1696  * Returns:
1697  *  If a match is found, its reference count of the found device is increased
1698  *  and it is returned; else %NULL is returned.
1699  */
1700 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1701                                        const char *bus_id)
1702 {
1703         struct device *dev;
1704
1705         dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
1706                                  __ccwdev_check_busid);
1707
1708         return dev ? to_ccwdev(dev) : NULL;
1709 }
1710
1711 /************************** device driver handling ************************/
1712
1713 /* This is the implementation of the ccw_driver class. The probe, remove
1714  * and release methods are initially very similar to the device_driver
1715  * implementations, with the difference that they have ccw_device
1716  * arguments.
1717  *
1718  * A ccw driver also contains the information that is needed for
1719  * device matching.
1720  */
1721 static int
1722 ccw_device_probe (struct device *dev)
1723 {
1724         struct ccw_device *cdev = to_ccwdev(dev);
1725         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1726         int ret;
1727
1728         cdev->drv = cdrv; /* to let the driver call _set_online */
1729         /* Note: we interpret class 0 in this context as an uninitialized
1730          * field since it translates to a non-I/O interrupt class. */
1731         if (cdrv->int_class != 0)
1732                 cdev->private->int_class = cdrv->int_class;
1733         else
1734                 cdev->private->int_class = IRQIO_CIO;
1735
1736         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1737
1738         if (ret) {
1739                 cdev->drv = NULL;
1740                 cdev->private->int_class = IRQIO_CIO;
1741                 return ret;
1742         }
1743
1744         return 0;
1745 }
1746
1747 static int ccw_device_remove(struct device *dev)
1748 {
1749         struct ccw_device *cdev = to_ccwdev(dev);
1750         struct ccw_driver *cdrv = cdev->drv;
1751         int ret;
1752
1753         if (cdrv->remove)
1754                 cdrv->remove(cdev);
1755
1756         spin_lock_irq(cdev->ccwlock);
1757         if (cdev->online) {
1758                 cdev->online = 0;
1759                 ret = ccw_device_offline(cdev);
1760                 spin_unlock_irq(cdev->ccwlock);
1761                 if (ret == 0)
1762                         wait_event(cdev->private->wait_q,
1763                                    dev_fsm_final_state(cdev));
1764                 else
1765                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1766                                       "device 0.%x.%04x\n",
1767                                       ret, cdev->private->dev_id.ssid,
1768                                       cdev->private->dev_id.devno);
1769                 /* Give up reference obtained in ccw_device_set_online(). */
1770                 put_device(&cdev->dev);
1771                 spin_lock_irq(cdev->ccwlock);
1772         }
1773         ccw_device_set_timeout(cdev, 0);
1774         cdev->drv = NULL;
1775         cdev->private->int_class = IRQIO_CIO;
1776         spin_unlock_irq(cdev->ccwlock);
1777         return 0;
1778 }
1779
1780 static void ccw_device_shutdown(struct device *dev)
1781 {
1782         struct ccw_device *cdev;
1783
1784         cdev = to_ccwdev(dev);
1785         if (cdev->drv && cdev->drv->shutdown)
1786                 cdev->drv->shutdown(cdev);
1787         disable_cmf(cdev);
1788 }
1789
1790 static int ccw_device_pm_prepare(struct device *dev)
1791 {
1792         struct ccw_device *cdev = to_ccwdev(dev);
1793
1794         if (work_pending(&cdev->private->todo_work))
1795                 return -EAGAIN;
1796         /* Fail while device is being set online/offline. */
1797         if (atomic_read(&cdev->private->onoff))
1798                 return -EAGAIN;
1799
1800         if (cdev->online && cdev->drv && cdev->drv->prepare)
1801                 return cdev->drv->prepare(cdev);
1802
1803         return 0;
1804 }
1805
1806 static void ccw_device_pm_complete(struct device *dev)
1807 {
1808         struct ccw_device *cdev = to_ccwdev(dev);
1809
1810         if (cdev->online && cdev->drv && cdev->drv->complete)
1811                 cdev->drv->complete(cdev);
1812 }
1813
1814 static int ccw_device_pm_freeze(struct device *dev)
1815 {
1816         struct ccw_device *cdev = to_ccwdev(dev);
1817         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1818         int ret, cm_enabled;
1819
1820         /* Fail suspend while device is in transistional state. */
1821         if (!dev_fsm_final_state(cdev))
1822                 return -EAGAIN;
1823         if (!cdev->online)
1824                 return 0;
1825         if (cdev->drv && cdev->drv->freeze) {
1826                 ret = cdev->drv->freeze(cdev);
1827                 if (ret)
1828                         return ret;
1829         }
1830
1831         spin_lock_irq(sch->lock);
1832         cm_enabled = cdev->private->cmb != NULL;
1833         spin_unlock_irq(sch->lock);
1834         if (cm_enabled) {
1835                 /* Don't have the css write on memory. */
1836                 ret = ccw_set_cmf(cdev, 0);
1837                 if (ret)
1838                         return ret;
1839         }
1840         /* From here on, disallow device driver I/O. */
1841         spin_lock_irq(sch->lock);
1842         ret = cio_disable_subchannel(sch);
1843         spin_unlock_irq(sch->lock);
1844
1845         return ret;
1846 }
1847
1848 static int ccw_device_pm_thaw(struct device *dev)
1849 {
1850         struct ccw_device *cdev = to_ccwdev(dev);
1851         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1852         int ret, cm_enabled;
1853
1854         if (!cdev->online)
1855                 return 0;
1856
1857         spin_lock_irq(sch->lock);
1858         /* Allow device driver I/O again. */
1859         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1860         cm_enabled = cdev->private->cmb != NULL;
1861         spin_unlock_irq(sch->lock);
1862         if (ret)
1863                 return ret;
1864
1865         if (cm_enabled) {
1866                 ret = ccw_set_cmf(cdev, 1);
1867                 if (ret)
1868                         return ret;
1869         }
1870
1871         if (cdev->drv && cdev->drv->thaw)
1872                 ret = cdev->drv->thaw(cdev);
1873
1874         return ret;
1875 }
1876
1877 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1878 {
1879         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1880
1881         spin_lock_irq(sch->lock);
1882         if (cio_is_console(sch->schid)) {
1883                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1884                 goto out_unlock;
1885         }
1886         /*
1887          * While we were sleeping, devices may have gone or become
1888          * available again. Kick re-detection.
1889          */
1890         cdev->private->flags.resuming = 1;
1891         cdev->private->path_new_mask = LPM_ANYPATH;
1892         css_sched_sch_todo(sch, SCH_TODO_EVAL);
1893         spin_unlock_irq(sch->lock);
1894         css_wait_for_slow_path();
1895
1896         /* cdev may have been moved to a different subchannel. */
1897         sch = to_subchannel(cdev->dev.parent);
1898         spin_lock_irq(sch->lock);
1899         if (cdev->private->state != DEV_STATE_ONLINE &&
1900             cdev->private->state != DEV_STATE_OFFLINE)
1901                 goto out_unlock;
1902
1903         ccw_device_recognition(cdev);
1904         spin_unlock_irq(sch->lock);
1905         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1906                    cdev->private->state == DEV_STATE_DISCONNECTED);
1907         spin_lock_irq(sch->lock);
1908
1909 out_unlock:
1910         cdev->private->flags.resuming = 0;
1911         spin_unlock_irq(sch->lock);
1912 }
1913
1914 static int resume_handle_boxed(struct ccw_device *cdev)
1915 {
1916         cdev->private->state = DEV_STATE_BOXED;
1917         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1918                 return 0;
1919         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1920         return -ENODEV;
1921 }
1922
1923 static int resume_handle_disc(struct ccw_device *cdev)
1924 {
1925         cdev->private->state = DEV_STATE_DISCONNECTED;
1926         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1927                 return 0;
1928         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1929         return -ENODEV;
1930 }
1931
1932 static int ccw_device_pm_restore(struct device *dev)
1933 {
1934         struct ccw_device *cdev = to_ccwdev(dev);
1935         struct subchannel *sch;
1936         int ret = 0;
1937
1938         __ccw_device_pm_restore(cdev);
1939         sch = to_subchannel(cdev->dev.parent);
1940         spin_lock_irq(sch->lock);
1941         if (cio_is_console(sch->schid))
1942                 goto out_restore;
1943
1944         /* check recognition results */
1945         switch (cdev->private->state) {
1946         case DEV_STATE_OFFLINE:
1947         case DEV_STATE_ONLINE:
1948                 cdev->private->flags.donotify = 0;
1949                 break;
1950         case DEV_STATE_BOXED:
1951                 ret = resume_handle_boxed(cdev);
1952                 if (ret)
1953                         goto out_unlock;
1954                 goto out_restore;
1955         default:
1956                 ret = resume_handle_disc(cdev);
1957                 if (ret)
1958                         goto out_unlock;
1959                 goto out_restore;
1960         }
1961         /* check if the device type has changed */
1962         if (!ccw_device_test_sense_data(cdev)) {
1963                 ccw_device_update_sense_data(cdev);
1964                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1965                 ret = -ENODEV;
1966                 goto out_unlock;
1967         }
1968         if (!cdev->online)
1969                 goto out_unlock;
1970
1971         if (ccw_device_online(cdev)) {
1972                 ret = resume_handle_disc(cdev);
1973                 if (ret)
1974                         goto out_unlock;
1975                 goto out_restore;
1976         }
1977         spin_unlock_irq(sch->lock);
1978         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1979         spin_lock_irq(sch->lock);
1980
1981         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1982                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1983                 ret = -ENODEV;
1984                 goto out_unlock;
1985         }
1986
1987         /* reenable cmf, if needed */
1988         if (cdev->private->cmb) {
1989                 spin_unlock_irq(sch->lock);
1990                 ret = ccw_set_cmf(cdev, 1);
1991                 spin_lock_irq(sch->lock);
1992                 if (ret) {
1993                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1994                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1995                                       cdev->private->dev_id.devno, ret);
1996                         ret = 0;
1997                 }
1998         }
1999
2000 out_restore:
2001         spin_unlock_irq(sch->lock);
2002         if (cdev->online && cdev->drv && cdev->drv->restore)
2003                 ret = cdev->drv->restore(cdev);
2004         return ret;
2005
2006 out_unlock:
2007         spin_unlock_irq(sch->lock);
2008         return ret;
2009 }
2010
2011 static const struct dev_pm_ops ccw_pm_ops = {
2012         .prepare = ccw_device_pm_prepare,
2013         .complete = ccw_device_pm_complete,
2014         .freeze = ccw_device_pm_freeze,
2015         .thaw = ccw_device_pm_thaw,
2016         .restore = ccw_device_pm_restore,
2017 };
2018
2019 static struct bus_type ccw_bus_type = {
2020         .name   = "ccw",
2021         .match  = ccw_bus_match,
2022         .uevent = ccw_uevent,
2023         .probe  = ccw_device_probe,
2024         .remove = ccw_device_remove,
2025         .shutdown = ccw_device_shutdown,
2026         .pm = &ccw_pm_ops,
2027 };
2028
2029 /**
2030  * ccw_driver_register() - register a ccw driver
2031  * @cdriver: driver to be registered
2032  *
2033  * This function is mainly a wrapper around driver_register().
2034  * Returns:
2035  *   %0 on success and a negative error value on failure.
2036  */
2037 int ccw_driver_register(struct ccw_driver *cdriver)
2038 {
2039         struct device_driver *drv = &cdriver->driver;
2040
2041         drv->bus = &ccw_bus_type;
2042
2043         return driver_register(drv);
2044 }
2045
2046 /**
2047  * ccw_driver_unregister() - deregister a ccw driver
2048  * @cdriver: driver to be deregistered
2049  *
2050  * This function is mainly a wrapper around driver_unregister().
2051  */
2052 void ccw_driver_unregister(struct ccw_driver *cdriver)
2053 {
2054         driver_unregister(&cdriver->driver);
2055 }
2056
2057 static void ccw_device_todo(struct work_struct *work)
2058 {
2059         struct ccw_device_private *priv;
2060         struct ccw_device *cdev;
2061         struct subchannel *sch;
2062         enum cdev_todo todo;
2063
2064         priv = container_of(work, struct ccw_device_private, todo_work);
2065         cdev = priv->cdev;
2066         sch = to_subchannel(cdev->dev.parent);
2067         /* Find out todo. */
2068         spin_lock_irq(cdev->ccwlock);
2069         todo = priv->todo;
2070         priv->todo = CDEV_TODO_NOTHING;
2071         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2072                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2073         spin_unlock_irq(cdev->ccwlock);
2074         /* Perform todo. */
2075         switch (todo) {
2076         case CDEV_TODO_ENABLE_CMF:
2077                 cmf_reenable(cdev);
2078                 break;
2079         case CDEV_TODO_REBIND:
2080                 ccw_device_do_unbind_bind(cdev);
2081                 break;
2082         case CDEV_TODO_REGISTER:
2083                 io_subchannel_register(cdev);
2084                 break;
2085         case CDEV_TODO_UNREG_EVAL:
2086                 if (!sch_is_pseudo_sch(sch))
2087                         css_schedule_eval(sch->schid);
2088                 /* fall-through */
2089         case CDEV_TODO_UNREG:
2090                 if (sch_is_pseudo_sch(sch))
2091                         ccw_device_unregister(cdev);
2092                 else
2093                         ccw_device_call_sch_unregister(cdev);
2094                 break;
2095         default:
2096                 break;
2097         }
2098         /* Release workqueue ref. */
2099         put_device(&cdev->dev);
2100 }
2101
2102 /**
2103  * ccw_device_sched_todo - schedule ccw device operation
2104  * @cdev: ccw device
2105  * @todo: todo
2106  *
2107  * Schedule the operation identified by @todo to be performed on the slow path
2108  * workqueue. Do nothing if another operation with higher priority is already
2109  * scheduled. Needs to be called with ccwdev lock held.
2110  */
2111 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2112 {
2113         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2114                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2115                       todo);
2116         if (cdev->private->todo >= todo)
2117                 return;
2118         cdev->private->todo = todo;
2119         /* Get workqueue ref. */
2120         if (!get_device(&cdev->dev))
2121                 return;
2122         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2123                 /* Already queued, release workqueue ref. */
2124                 put_device(&cdev->dev);
2125         }
2126 }
2127
2128 /**
2129  * ccw_device_siosl() - initiate logging
2130  * @cdev: ccw device
2131  *
2132  * This function is used to invoke model-dependent logging within the channel
2133  * subsystem.
2134  */
2135 int ccw_device_siosl(struct ccw_device *cdev)
2136 {
2137         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2138
2139         return chsc_siosl(sch->schid);
2140 }
2141 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2142
2143 MODULE_LICENSE("GPL");
2144 EXPORT_SYMBOL(ccw_device_set_online);
2145 EXPORT_SYMBOL(ccw_device_set_offline);
2146 EXPORT_SYMBOL(ccw_driver_register);
2147 EXPORT_SYMBOL(ccw_driver_unregister);
2148 EXPORT_SYMBOL(get_ccwdev_by_busid);