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         cdev->online = 0;
 337         spin_lock_irq(cdev->ccwlock);
 338         sch = to_subchannel(cdev->dev.parent);
 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         cdev->online = 1;
 450         return 0;
 451
 452 rollback:
 453         spin_lock_irq(cdev->ccwlock);
 454         /* Wait until a final state or DISCONNECTED is reached */
 455         while (!dev_fsm_final_state(cdev) &&
 456                cdev->private->state != DEV_STATE_DISCONNECTED) {
 457                 spin_unlock_irq(cdev->ccwlock);
 458                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 459                            cdev->private->state == DEV_STATE_DISCONNECTED));
 460                 spin_lock_irq(cdev->ccwlock);
 461         }
 462         ret2 = ccw_device_offline(cdev);
 463         if (ret2)
 464                 goto error;
 465         spin_unlock_irq(cdev->ccwlock);
 466         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 467                    cdev->private->state == DEV_STATE_DISCONNECTED));
 468         /* Give up online reference since onlining failed. */
 469         put_device(&cdev->dev);
 470         return ret;
 471
 472 error:
 473         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 474                       "device 0.%x.%04x\n",
 475                       ret2, cdev->private->dev_id.ssid,
 476                       cdev->private->dev_id.devno);
 477         cdev->private->state = DEV_STATE_OFFLINE;
 478         spin_unlock_irq(cdev->ccwlock);
 479         /* Give up online reference since onlining failed. */
 480         put_device(&cdev->dev);
 481         return ret;
 482 }
 483
 484 static int online_store_handle_offline(struct ccw_device *cdev)
 485 {
 486         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 487                 spin_lock_irq(cdev->ccwlock);
 488                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 489                 spin_unlock_irq(cdev->ccwlock);
 490                 return 0;
 491         }
 492         if (cdev->drv && cdev->drv->set_offline)
 493                 return ccw_device_set_offline(cdev);
 494         return -EINVAL;
 495 }
 496
 497 static int online_store_recog_and_online(struct ccw_device *cdev)
 498 {
 499         /* Do device recognition, if needed. */
 500         if (cdev->private->state == DEV_STATE_BOXED) {
 501                 spin_lock_irq(cdev->ccwlock);
 502                 ccw_device_recognition(cdev);
 503                 spin_unlock_irq(cdev->ccwlock);
 504                 wait_event(cdev->private->wait_q,
 505                            cdev->private->flags.recog_done);
 506                 if (cdev->private->state != DEV_STATE_OFFLINE)
 507                         /* recognition failed */
 508                         return -EAGAIN;
 509         }
 510         if (cdev->drv && cdev->drv->set_online)
 511                 return ccw_device_set_online(cdev);
 512         return -EINVAL;
 513 }
 514
 515 static int online_store_handle_online(struct ccw_device *cdev, int force)
 516 {
 517         int ret;
 518
 519         ret = online_store_recog_and_online(cdev);
 520         if (ret && !force)
 521                 return ret;
 522         if (force && cdev->private->state == DEV_STATE_BOXED) {
 523                 ret = ccw_device_stlck(cdev);
 524                 if (ret)
 525                         return ret;
 526                 if (cdev->id.cu_type == 0)
 527                         cdev->private->state = DEV_STATE_NOT_OPER;
 528                 ret = online_store_recog_and_online(cdev);
 529                 if (ret)
 530                         return ret;
 531         }
 532         return 0;
 533 }
 534
 535 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 536                              const char *buf, size_t count)
 537 {
 538         struct ccw_device *cdev = to_ccwdev(dev);
 539         int force, ret;
 540         unsigned long i;
 541
 542         /* Prevent conflict between multiple on-/offline processing requests. */
 543         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 544                 return -EAGAIN;
 545         /* Prevent conflict between internal I/Os and on-/offline processing. */
 546         if (!dev_fsm_final_state(cdev) &&
 547             cdev->private->state != DEV_STATE_DISCONNECTED) {
 548                 ret = -EAGAIN;
 549                 goto out_onoff;
 550         }
 551         /* Prevent conflict between pending work and on-/offline processing.*/
 552         if (work_pending(&cdev->private->todo_work)) {
 553                 ret = -EAGAIN;
 554                 goto out_onoff;
 555         }
 556
 557         if (cdev->drv && !try_module_get(cdev->drv->driver.owner)) {
 558                 ret = -EINVAL;
 559                 goto out_onoff;
 560         }
 561         if (!strncmp(buf, "force\n", count)) {
 562                 force = 1;
 563                 i = 1;
 564                 ret = 0;
 565         } else {
 566                 force = 0;
 567                 ret = kstrtoul(buf, 16, &i);
 568         }
 569         if (ret)
 570                 goto out;
 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 out:
 582         if (cdev->drv)
 583                 module_put(cdev->drv->driver.owner);
 584 out_onoff:
 585         atomic_set(&cdev->private->onoff, 0);
 586         return (ret < 0) ? ret : count;
 587 }
 588
 589 static ssize_t
 590 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 591 {
 592         struct ccw_device *cdev = to_ccwdev(dev);
 593         struct subchannel *sch;
 594
 595         if (ccw_device_is_orphan(cdev))
 596                 return sprintf(buf, "no device\n");
 597         switch (cdev->private->state) {
 598         case DEV_STATE_BOXED:
 599                 return sprintf(buf, "boxed\n");
 600         case DEV_STATE_DISCONNECTED:
 601         case DEV_STATE_DISCONNECTED_SENSE_ID:
 602         case DEV_STATE_NOT_OPER:
 603                 sch = to_subchannel(dev->parent);
 604                 if (!sch->lpm)
 605                         return sprintf(buf, "no path\n");
 606                 else
 607                         return sprintf(buf, "no device\n");
 608         default:
 609                 /* All other states considered fine. */
 610                 return sprintf(buf, "good\n");
 611         }
 612 }
 613
 614 static ssize_t
 615 initiate_logging(struct device *dev, struct device_attribute *attr,
 616                  const char *buf, size_t count)
 617 {
 618         struct subchannel *sch = to_subchannel(dev);
 619         int rc;
 620
 621         rc = chsc_siosl(sch->schid);
 622         if (rc < 0) {
 623                 pr_warning("Logging for subchannel 0.%x.%04x failed with "
 624                            "errno=%d\n",
 625                            sch->schid.ssid, sch->schid.sch_no, rc);
 626                 return rc;
 627         }
 628         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 629                   sch->schid.ssid, sch->schid.sch_no);
 630         return count;
 631 }
 632
 633 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 634                         char *buf)
 635 {
 636         struct subchannel *sch = to_subchannel(dev);
 637
 638         return sprintf(buf, "%02x\n", sch->vpm);
 639 }
 640
 641 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 642 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 643 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 644 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 645 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 646 static DEVICE_ATTR(online, 0644, online_show, online_store);
 647 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 648 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 649 static DEVICE_ATTR(vpm, 0444, vpm_show, NULL);
 650
 651 static struct attribute *io_subchannel_attrs[] = {
 652         &dev_attr_chpids.attr,
 653         &dev_attr_pimpampom.attr,
 654         &dev_attr_logging.attr,
 655         &dev_attr_vpm.attr,
 656         NULL,
 657 };
 658
 659 static struct attribute_group io_subchannel_attr_group = {
 660         .attrs = io_subchannel_attrs,
 661 };
 662
 663 static struct attribute * ccwdev_attrs[] = {
 664         &dev_attr_devtype.attr,
 665         &dev_attr_cutype.attr,
 666         &dev_attr_modalias.attr,
 667         &dev_attr_online.attr,
 668         &dev_attr_cmb_enable.attr,
 669         &dev_attr_availability.attr,
 670         NULL,
 671 };
 672
 673 static struct attribute_group ccwdev_attr_group = {
 674         .attrs = ccwdev_attrs,
 675 };
 676
 677 static const struct attribute_group *ccwdev_attr_groups[] = {
 678         &ccwdev_attr_group,
 679         NULL,
 680 };
 681
 682 /* this is a simple abstraction for device_register that sets the
 683  * correct bus type and adds the bus specific files */
 684 static int ccw_device_register(struct ccw_device *cdev)
 685 {
 686         struct device *dev = &cdev->dev;
 687         int ret;
 688
 689         dev->bus = &ccw_bus_type;
 690         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 691                            cdev->private->dev_id.devno);
 692         if (ret)
 693                 return ret;
 694         return device_add(dev);
 695 }
 696
 697 static int match_dev_id(struct device *dev, void *data)
 698 {
 699         struct ccw_device *cdev = to_ccwdev(dev);
 700         struct ccw_dev_id *dev_id = data;
 701
 702         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 703 }
 704
 705 /**
 706  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 707  * @dev_id: id of the device to be searched
 708  *
 709  * This function searches all devices attached to the ccw bus for a device
 710  * matching @dev_id.
 711  * Returns:
 712  *  If a device is found its reference count is increased and returned;
 713  *  else %NULL is returned.
 714  */
 715 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 716 {
 717         struct device *dev;
 718
 719         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 720
 721         return dev ? to_ccwdev(dev) : NULL;
 722 }
 723 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 724
 725 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 726 {
 727         int ret;
 728
 729         if (device_is_registered(&cdev->dev)) {
 730                 device_release_driver(&cdev->dev);
 731                 ret = device_attach(&cdev->dev);
 732                 WARN_ON(ret == -ENODEV);
 733         }
 734 }
 735
 736 static void
 737 ccw_device_release(struct device *dev)
 738 {
 739         struct ccw_device *cdev;
 740
 741         cdev = to_ccwdev(dev);
 742         /* Release reference of parent subchannel. */
 743         put_device(cdev->dev.parent);
 744         kfree(cdev->private);
 745         kfree(cdev);
 746 }
 747
 748 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 749 {
 750         struct ccw_device *cdev;
 751
 752         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 753         if (cdev) {
 754                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 755                                         GFP_KERNEL | GFP_DMA);
 756                 if (cdev->private)
 757                         return cdev;
 758         }
 759         kfree(cdev);
 760         return ERR_PTR(-ENOMEM);
 761 }
 762
 763 static void ccw_device_todo(struct work_struct *work);
 764
 765 static int io_subchannel_initialize_dev(struct subchannel *sch,
 766                                         struct ccw_device *cdev)
 767 {
 768         cdev->private->cdev = cdev;
 769         cdev->private->int_class = IRQIO_CIO;
 770         atomic_set(&cdev->private->onoff, 0);
 771         cdev->dev.parent = &sch->dev;
 772         cdev->dev.release = ccw_device_release;
 773         INIT_WORK(&cdev->private->todo_work, ccw_device_todo);
 774         cdev->dev.groups = ccwdev_attr_groups;
 775         /* Do first half of device_register. */
 776         device_initialize(&cdev->dev);
 777         if (!get_device(&sch->dev)) {
 778                 /* Release reference from device_initialize(). */
 779                 put_device(&cdev->dev);
 780                 return -ENODEV;
 781         }
 782         cdev->private->flags.initialized = 1;
 783         return 0;
 784 }
 785
 786 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 787 {
 788         struct ccw_device *cdev;
 789         int ret;
 790
 791         cdev = io_subchannel_allocate_dev(sch);
 792         if (!IS_ERR(cdev)) {
 793                 ret = io_subchannel_initialize_dev(sch, cdev);
 794                 if (ret)
 795                         cdev = ERR_PTR(ret);
 796         }
 797         return cdev;
 798 }
 799
 800 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 801
 802 static void sch_create_and_recog_new_device(struct subchannel *sch)
 803 {
 804         struct ccw_device *cdev;
 805
 806         /* Need to allocate a new ccw device. */
 807         cdev = io_subchannel_create_ccwdev(sch);
 808         if (IS_ERR(cdev)) {
 809                 /* OK, we did everything we could... */
 810                 css_sch_device_unregister(sch);
 811                 return;
 812         }
 813         /* Start recognition for the new ccw device. */
 814         io_subchannel_recog(cdev, sch);
 815 }
 816
 817 /*
 818  * Register recognized device.
 819  */
 820 static void io_subchannel_register(struct ccw_device *cdev)
 821 {
 822         struct subchannel *sch;
 823         int ret, adjust_init_count = 1;
 824         unsigned long flags;
 825
 826         sch = to_subchannel(cdev->dev.parent);
 827         /*
 828          * Check if subchannel is still registered. It may have become
 829          * unregistered if a machine check hit us after finishing
 830          * device recognition but before the register work could be
 831          * queued.
 832          */
 833         if (!device_is_registered(&sch->dev))
 834                 goto out_err;
 835         css_update_ssd_info(sch);
 836         /*
 837          * io_subchannel_register() will also be called after device
 838          * recognition has been done for a boxed device (which will already
 839          * be registered). We need to reprobe since we may now have sense id
 840          * information.
 841          */
 842         if (device_is_registered(&cdev->dev)) {
 843                 if (!cdev->drv) {
 844                         ret = device_reprobe(&cdev->dev);
 845                         if (ret)
 846                                 /* We can't do much here. */
 847                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 848                                               " %d for 0.%x.%04x\n", ret,
 849                                               cdev->private->dev_id.ssid,
 850                                               cdev->private->dev_id.devno);
 851                 }
 852                 adjust_init_count = 0;
 853                 goto out;
 854         }
 855         /*
 856          * Now we know this subchannel will stay, we can throw
 857          * our delayed uevent.
 858          */
 859         dev_set_uevent_suppress(&sch->dev, 0);
 860         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 861         /* make it known to the system */
 862         ret = ccw_device_register(cdev);
 863         if (ret) {
 864                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 865                               cdev->private->dev_id.ssid,
 866                               cdev->private->dev_id.devno, ret);
 867                 spin_lock_irqsave(sch->lock, flags);
 868                 sch_set_cdev(sch, NULL);
 869                 spin_unlock_irqrestore(sch->lock, flags);
 870                 /* Release initial device reference. */
 871                 put_device(&cdev->dev);
 872                 goto out_err;
 873         }
 874 out:
 875         cdev->private->flags.recog_done = 1;
 876         wake_up(&cdev->private->wait_q);
 877 out_err:
 878         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 879                 wake_up(&ccw_device_init_wq);
 880 }
 881
 882 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 883 {
 884         struct subchannel *sch;
 885
 886         /* Get subchannel reference for local processing. */
 887         if (!get_device(cdev->dev.parent))
 888                 return;
 889         sch = to_subchannel(cdev->dev.parent);
 890         css_sch_device_unregister(sch);
 891         /* Release subchannel reference for local processing. */
 892         put_device(&sch->dev);
 893 }
 894
 895 /*
 896  * subchannel recognition done. Called from the state machine.
 897  */
 898 void
 899 io_subchannel_recog_done(struct ccw_device *cdev)
 900 {
 901         if (css_init_done == 0) {
 902                 cdev->private->flags.recog_done = 1;
 903                 return;
 904         }
 905         switch (cdev->private->state) {
 906         case DEV_STATE_BOXED:
 907                 /* Device did not respond in time. */
 908         case DEV_STATE_NOT_OPER:
 909                 cdev->private->flags.recog_done = 1;
 910                 /* Remove device found not operational. */
 911                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 912                 if (atomic_dec_and_test(&ccw_device_init_count))
 913                         wake_up(&ccw_device_init_wq);
 914                 break;
 915         case DEV_STATE_OFFLINE:
 916                 /*
 917                  * We can't register the device in interrupt context so
 918                  * we schedule a work item.
 919                  */
 920                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 921                 break;
 922         }
 923 }
 924
 925 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 926 {
 927         struct ccw_device_private *priv;
 928
 929         cdev->ccwlock = sch->lock;
 930
 931         /* Init private data. */
 932         priv = cdev->private;
 933         priv->dev_id.devno = sch->schib.pmcw.dev;
 934         priv->dev_id.ssid = sch->schid.ssid;
 935         priv->schid = sch->schid;
 936         priv->state = DEV_STATE_NOT_OPER;
 937         INIT_LIST_HEAD(&priv->cmb_list);
 938         init_waitqueue_head(&priv->wait_q);
 939         init_timer(&priv->timer);
 940
 941         /* Increase counter of devices currently in recognition. */
 942         atomic_inc(&ccw_device_init_count);
 943
 944         /* Start async. device sensing. */
 945         spin_lock_irq(sch->lock);
 946         sch_set_cdev(sch, cdev);
 947         ccw_device_recognition(cdev);
 948         spin_unlock_irq(sch->lock);
 949 }
 950
 951 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 952                                   struct subchannel *sch)
 953 {
 954         struct subchannel *old_sch;
 955         int rc, old_enabled = 0;
 956
 957         old_sch = to_subchannel(cdev->dev.parent);
 958         /* Obtain child reference for new parent. */
 959         if (!get_device(&sch->dev))
 960                 return -ENODEV;
 961
 962         if (!sch_is_pseudo_sch(old_sch)) {
 963                 spin_lock_irq(old_sch->lock);
 964                 old_enabled = old_sch->schib.pmcw.ena;
 965                 rc = 0;
 966                 if (old_enabled)
 967                         rc = cio_disable_subchannel(old_sch);
 968                 spin_unlock_irq(old_sch->lock);
 969                 if (rc == -EBUSY) {
 970                         /* Release child reference for new parent. */
 971                         put_device(&sch->dev);
 972                         return rc;
 973                 }
 974         }
 975
 976         mutex_lock(&sch->reg_mutex);
 977         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 978         mutex_unlock(&sch->reg_mutex);
 979         if (rc) {
 980                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 981                               cdev->private->dev_id.ssid,
 982                               cdev->private->dev_id.devno, sch->schid.ssid,
 983                               sch->schib.pmcw.dev, rc);
 984                 if (old_enabled) {
 985                         /* Try to reenable the old subchannel. */
 986                         spin_lock_irq(old_sch->lock);
 987                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 988                         spin_unlock_irq(old_sch->lock);
 989                 }
 990                 /* Release child reference for new parent. */
 991                 put_device(&sch->dev);
 992                 return rc;
 993         }
 994         /* Clean up old subchannel. */
 995         if (!sch_is_pseudo_sch(old_sch)) {
 996                 spin_lock_irq(old_sch->lock);
 997                 sch_set_cdev(old_sch, NULL);
 998                 spin_unlock_irq(old_sch->lock);
 999                 css_schedule_eval(old_sch->schid);
1000         }
1001         /* Release child reference for old parent. */
1002         put_device(&old_sch->dev);
1003         /* Initialize new subchannel. */
1004         spin_lock_irq(sch->lock);
1005         cdev->private->schid = sch->schid;
1006         cdev->ccwlock = sch->lock;
1007         if (!sch_is_pseudo_sch(sch))
1008                 sch_set_cdev(sch, cdev);
1009         spin_unlock_irq(sch->lock);
1010         if (!sch_is_pseudo_sch(sch))
1011                 css_update_ssd_info(sch);
1012         return 0;
1013 }
1014
1015 static int ccw_device_move_to_orph(struct ccw_device *cdev)
1016 {
1017         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1018         struct channel_subsystem *css = to_css(sch->dev.parent);
1019
1020         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
1021 }
1022
1023 static void io_subchannel_irq(struct subchannel *sch)
1024 {
1025         struct ccw_device *cdev;
1026
1027         cdev = sch_get_cdev(sch);
1028
1029         CIO_TRACE_EVENT(6, "IRQ");
1030         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1031         if (cdev)
1032                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1033         else
1034                 inc_irq_stat(IRQIO_CIO);
1035 }
1036
1037 void io_subchannel_init_config(struct subchannel *sch)
1038 {
1039         memset(&sch->config, 0, sizeof(sch->config));
1040         sch->config.csense = 1;
1041 }
1042
1043 static void io_subchannel_init_fields(struct subchannel *sch)
1044 {
1045         if (cio_is_console(sch->schid))
1046                 sch->opm = 0xff;
1047         else
1048                 sch->opm = chp_get_sch_opm(sch);
1049         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1050         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1051
1052         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1053                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1054                       sch->schib.pmcw.dev, sch->schid.ssid,
1055                       sch->schid.sch_no, sch->schib.pmcw.pim,
1056                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1057
1058         io_subchannel_init_config(sch);
1059 }
1060
1061 /*
1062  * Note: We always return 0 so that we bind to the device even on error.
1063  * This is needed so that our remove function is called on unregister.
1064  */
1065 static int io_subchannel_probe(struct subchannel *sch)
1066 {
1067         struct io_subchannel_private *io_priv;
1068         struct ccw_device *cdev;
1069         int rc;
1070
1071         if (cio_is_console(sch->schid)) {
1072                 rc = sysfs_create_group(&sch->dev.kobj,
1073                                         &io_subchannel_attr_group);
1074                 if (rc)
1075                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1076                                       "attributes for subchannel "
1077                                       "0.%x.%04x (rc=%d)\n",
1078                                       sch->schid.ssid, sch->schid.sch_no, rc);
1079                 /*
1080                  * The console subchannel already has an associated ccw_device.
1081                  * Throw the delayed uevent for the subchannel, register
1082                  * the ccw_device and exit.
1083                  */
1084                 dev_set_uevent_suppress(&sch->dev, 0);
1085                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1086                 cdev = sch_get_cdev(sch);
1087                 rc = ccw_device_register(cdev);
1088                 if (rc) {
1089                         /* Release online reference. */
1090                         put_device(&cdev->dev);
1091                         goto out_schedule;
1092                 }
1093                 if (atomic_dec_and_test(&ccw_device_init_count))
1094                         wake_up(&ccw_device_init_wq);
1095                 return 0;
1096         }
1097         io_subchannel_init_fields(sch);
1098         rc = cio_commit_config(sch);
1099         if (rc)
1100                 goto out_schedule;
1101         rc = sysfs_create_group(&sch->dev.kobj,
1102                                 &io_subchannel_attr_group);
1103         if (rc)
1104                 goto out_schedule;
1105         /* Allocate I/O subchannel private data. */
1106         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1107         if (!io_priv)
1108                 goto out_schedule;
1109
1110         set_io_private(sch, io_priv);
1111         css_schedule_eval(sch->schid);
1112         return 0;
1113
1114 out_schedule:
1115         spin_lock_irq(sch->lock);
1116         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1117         spin_unlock_irq(sch->lock);
1118         return 0;
1119 }
1120
1121 static int
1122 io_subchannel_remove (struct subchannel *sch)
1123 {
1124         struct io_subchannel_private *io_priv = to_io_private(sch);
1125         struct ccw_device *cdev;
1126
1127         cdev = sch_get_cdev(sch);
1128         if (!cdev)
1129                 goto out_free;
1130         io_subchannel_quiesce(sch);
1131         /* Set ccw device to not operational and drop reference. */
1132         spin_lock_irq(cdev->ccwlock);
1133         sch_set_cdev(sch, NULL);
1134         set_io_private(sch, NULL);
1135         cdev->private->state = DEV_STATE_NOT_OPER;
1136         spin_unlock_irq(cdev->ccwlock);
1137         ccw_device_unregister(cdev);
1138 out_free:
1139         kfree(io_priv);
1140         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1141         return 0;
1142 }
1143
1144 static void io_subchannel_verify(struct subchannel *sch)
1145 {
1146         struct ccw_device *cdev;
1147
1148         cdev = sch_get_cdev(sch);
1149         if (cdev)
1150                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1151 }
1152
1153 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1154 {
1155         struct ccw_device *cdev;
1156
1157         cdev = sch_get_cdev(sch);
1158         if (!cdev)
1159                 return;
1160         if (cio_update_schib(sch))
1161                 goto err;
1162         /* Check for I/O on path. */
1163         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1164                 goto out;
1165         if (cdev->private->state == DEV_STATE_ONLINE) {
1166                 ccw_device_kill_io(cdev);
1167                 goto out;
1168         }
1169         if (cio_clear(sch))
1170                 goto err;
1171 out:
1172         /* Trigger path verification. */
1173         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1174         return;
1175
1176 err:
1177         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1178 }
1179
1180 static int io_subchannel_chp_event(struct subchannel *sch,
1181                                    struct chp_link *link, int event)
1182 {
1183         struct ccw_device *cdev = sch_get_cdev(sch);
1184         int mask;
1185
1186         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1187         if (!mask)
1188                 return 0;
1189         switch (event) {
1190         case CHP_VARY_OFF:
1191                 sch->opm &= ~mask;
1192                 sch->lpm &= ~mask;
1193                 if (cdev)
1194                         cdev->private->path_gone_mask |= mask;
1195                 io_subchannel_terminate_path(sch, mask);
1196                 break;
1197         case CHP_VARY_ON:
1198                 sch->opm |= mask;
1199                 sch->lpm |= mask;
1200                 if (cdev)
1201                         cdev->private->path_new_mask |= mask;
1202                 io_subchannel_verify(sch);
1203                 break;
1204         case CHP_OFFLINE:
1205                 if (cio_update_schib(sch))
1206                         return -ENODEV;
1207                 if (cdev)
1208                         cdev->private->path_gone_mask |= mask;
1209                 io_subchannel_terminate_path(sch, mask);
1210                 break;
1211         case CHP_ONLINE:
1212                 if (cio_update_schib(sch))
1213                         return -ENODEV;
1214                 sch->lpm |= mask & sch->opm;
1215                 if (cdev)
1216                         cdev->private->path_new_mask |= mask;
1217                 io_subchannel_verify(sch);
1218                 break;
1219         }
1220         return 0;
1221 }
1222
1223 static void io_subchannel_quiesce(struct subchannel *sch)
1224 {
1225         struct ccw_device *cdev;
1226         int ret;
1227
1228         spin_lock_irq(sch->lock);
1229         cdev = sch_get_cdev(sch);
1230         if (cio_is_console(sch->schid))
1231                 goto out_unlock;
1232         if (!sch->schib.pmcw.ena)
1233                 goto out_unlock;
1234         ret = cio_disable_subchannel(sch);
1235         if (ret != -EBUSY)
1236                 goto out_unlock;
1237         if (cdev->handler)
1238                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1239         while (ret == -EBUSY) {
1240                 cdev->private->state = DEV_STATE_QUIESCE;
1241                 cdev->private->iretry = 255;
1242                 ret = ccw_device_cancel_halt_clear(cdev);
1243                 if (ret == -EBUSY) {
1244                         ccw_device_set_timeout(cdev, HZ/10);
1245                         spin_unlock_irq(sch->lock);
1246                         wait_event(cdev->private->wait_q,
1247                                    cdev->private->state != DEV_STATE_QUIESCE);
1248                         spin_lock_irq(sch->lock);
1249                 }
1250                 ret = cio_disable_subchannel(sch);
1251         }
1252 out_unlock:
1253         spin_unlock_irq(sch->lock);
1254 }
1255
1256 static void io_subchannel_shutdown(struct subchannel *sch)
1257 {
1258         io_subchannel_quiesce(sch);
1259 }
1260
1261 static int device_is_disconnected(struct ccw_device *cdev)
1262 {
1263         if (!cdev)
1264                 return 0;
1265         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1266                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1267 }
1268
1269 static int recovery_check(struct device *dev, void *data)
1270 {
1271         struct ccw_device *cdev = to_ccwdev(dev);
1272         int *redo = data;
1273
1274         spin_lock_irq(cdev->ccwlock);
1275         switch (cdev->private->state) {
1276         case DEV_STATE_DISCONNECTED:
1277                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1278                               cdev->private->dev_id.ssid,
1279                               cdev->private->dev_id.devno);
1280                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1281                 *redo = 1;
1282                 break;
1283         case DEV_STATE_DISCONNECTED_SENSE_ID:
1284                 *redo = 1;
1285                 break;
1286         }
1287         spin_unlock_irq(cdev->ccwlock);
1288
1289         return 0;
1290 }
1291
1292 static void recovery_work_func(struct work_struct *unused)
1293 {
1294         int redo = 0;
1295
1296         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1297         if (redo) {
1298                 spin_lock_irq(&recovery_lock);
1299                 if (!timer_pending(&recovery_timer)) {
1300                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1301                                 recovery_phase++;
1302                         mod_timer(&recovery_timer, jiffies +
1303                                   recovery_delay[recovery_phase] * HZ);
1304                 }
1305                 spin_unlock_irq(&recovery_lock);
1306         } else
1307                 CIO_MSG_EVENT(4, "recovery: end\n");
1308 }
1309
1310 static DECLARE_WORK(recovery_work, recovery_work_func);
1311
1312 static void recovery_func(unsigned long data)
1313 {
1314         /*
1315          * We can't do our recovery in softirq context and it's not
1316          * performance critical, so we schedule it.
1317          */
1318         schedule_work(&recovery_work);
1319 }
1320
1321 static void ccw_device_schedule_recovery(void)
1322 {
1323         unsigned long flags;
1324
1325         CIO_MSG_EVENT(4, "recovery: schedule\n");
1326         spin_lock_irqsave(&recovery_lock, flags);
1327         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1328                 recovery_phase = 0;
1329                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1330         }
1331         spin_unlock_irqrestore(&recovery_lock, flags);
1332 }
1333
1334 static int purge_fn(struct device *dev, void *data)
1335 {
1336         struct ccw_device *cdev = to_ccwdev(dev);
1337         struct ccw_dev_id *id = &cdev->private->dev_id;
1338
1339         spin_lock_irq(cdev->ccwlock);
1340         if (is_blacklisted(id->ssid, id->devno) &&
1341             (cdev->private->state == DEV_STATE_OFFLINE) &&
1342             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1343                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1344                               id->devno);
1345                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1346                 atomic_set(&cdev->private->onoff, 0);
1347         }
1348         spin_unlock_irq(cdev->ccwlock);
1349         /* Abort loop in case of pending signal. */
1350         if (signal_pending(current))
1351                 return -EINTR;
1352
1353         return 0;
1354 }
1355
1356 /**
1357  * ccw_purge_blacklisted - purge unused, blacklisted devices
1358  *
1359  * Unregister all ccw devices that are offline and on the blacklist.
1360  */
1361 int ccw_purge_blacklisted(void)
1362 {
1363         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1364         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1365         return 0;
1366 }
1367
1368 void ccw_device_set_disconnected(struct ccw_device *cdev)
1369 {
1370         if (!cdev)
1371                 return;
1372         ccw_device_set_timeout(cdev, 0);
1373         cdev->private->flags.fake_irb = 0;
1374         cdev->private->state = DEV_STATE_DISCONNECTED;
1375         if (cdev->online)
1376                 ccw_device_schedule_recovery();
1377 }
1378
1379 void ccw_device_set_notoper(struct ccw_device *cdev)
1380 {
1381         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1382
1383         CIO_TRACE_EVENT(2, "notoper");
1384         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1385         ccw_device_set_timeout(cdev, 0);
1386         cio_disable_subchannel(sch);
1387         cdev->private->state = DEV_STATE_NOT_OPER;
1388 }
1389
1390 enum io_sch_action {
1391         IO_SCH_UNREG,
1392         IO_SCH_ORPH_UNREG,
1393         IO_SCH_ATTACH,
1394         IO_SCH_UNREG_ATTACH,
1395         IO_SCH_ORPH_ATTACH,
1396         IO_SCH_REPROBE,
1397         IO_SCH_VERIFY,
1398         IO_SCH_DISC,
1399         IO_SCH_NOP,
1400 };
1401
1402 static enum io_sch_action sch_get_action(struct subchannel *sch)
1403 {
1404         struct ccw_device *cdev;
1405
1406         cdev = sch_get_cdev(sch);
1407         if (cio_update_schib(sch)) {
1408                 /* Not operational. */
1409                 if (!cdev)
1410                         return IO_SCH_UNREG;
1411                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1412                         return IO_SCH_UNREG;
1413                 return IO_SCH_ORPH_UNREG;
1414         }
1415         /* Operational. */
1416         if (!cdev)
1417                 return IO_SCH_ATTACH;
1418         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1419                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1420                         return IO_SCH_UNREG_ATTACH;
1421                 return IO_SCH_ORPH_ATTACH;
1422         }
1423         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1424                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1425                         return IO_SCH_UNREG;
1426                 return IO_SCH_DISC;
1427         }
1428         if (device_is_disconnected(cdev))
1429                 return IO_SCH_REPROBE;
1430         if (cdev->online && !cdev->private->flags.resuming)
1431                 return IO_SCH_VERIFY;
1432         if (cdev->private->state == DEV_STATE_NOT_OPER)
1433                 return IO_SCH_UNREG_ATTACH;
1434         return IO_SCH_NOP;
1435 }
1436
1437 /**
1438  * io_subchannel_sch_event - process subchannel event
1439  * @sch: subchannel
1440  * @process: non-zero if function is called in process context
1441  *
1442  * An unspecified event occurred for this subchannel. Adjust data according
1443  * to the current operational state of the subchannel and device. Return
1444  * zero when the event has been handled sufficiently or -EAGAIN when this
1445  * function should be called again in process context.
1446  */
1447 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1448 {
1449         unsigned long flags;
1450         struct ccw_device *cdev;
1451         struct ccw_dev_id dev_id;
1452         enum io_sch_action action;
1453         int rc = -EAGAIN;
1454
1455         spin_lock_irqsave(sch->lock, flags);
1456         if (!device_is_registered(&sch->dev))
1457                 goto out_unlock;
1458         if (work_pending(&sch->todo_work))
1459                 goto out_unlock;
1460         cdev = sch_get_cdev(sch);
1461         if (cdev && work_pending(&cdev->private->todo_work))
1462                 goto out_unlock;
1463         action = sch_get_action(sch);
1464         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1465                       sch->schid.ssid, sch->schid.sch_no, process,
1466                       action);
1467         /* Perform immediate actions while holding the lock. */
1468         switch (action) {
1469         case IO_SCH_REPROBE:
1470                 /* Trigger device recognition. */
1471                 ccw_device_trigger_reprobe(cdev);
1472                 rc = 0;
1473                 goto out_unlock;
1474         case IO_SCH_VERIFY:
1475                 /* Trigger path verification. */
1476                 io_subchannel_verify(sch);
1477                 rc = 0;
1478                 goto out_unlock;
1479         case IO_SCH_DISC:
1480                 ccw_device_set_disconnected(cdev);
1481                 rc = 0;
1482                 goto out_unlock;
1483         case IO_SCH_ORPH_UNREG:
1484         case IO_SCH_ORPH_ATTACH:
1485                 ccw_device_set_disconnected(cdev);
1486                 break;
1487         case IO_SCH_UNREG_ATTACH:
1488         case IO_SCH_UNREG:
1489                 if (!cdev)
1490                         break;
1491                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1492                         /*
1493                          * Note: delayed work triggered by this event
1494                          * and repeated calls to sch_event are synchronized
1495                          * by the above check for work_pending(cdev).
1496                          */
1497                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1498                 } else
1499                         ccw_device_set_notoper(cdev);
1500                 break;
1501         case IO_SCH_NOP:
1502                 rc = 0;
1503                 goto out_unlock;
1504         default:
1505                 break;
1506         }
1507         spin_unlock_irqrestore(sch->lock, flags);
1508         /* All other actions require process context. */
1509         if (!process)
1510                 goto out;
1511         /* Handle attached ccw device. */
1512         switch (action) {
1513         case IO_SCH_ORPH_UNREG:
1514         case IO_SCH_ORPH_ATTACH:
1515                 /* Move ccw device to orphanage. */
1516                 rc = ccw_device_move_to_orph(cdev);
1517                 if (rc)
1518                         goto out;
1519                 break;
1520         case IO_SCH_UNREG_ATTACH:
1521                 spin_lock_irqsave(sch->lock, flags);
1522                 if (cdev->private->flags.resuming) {
1523                         /* Device will be handled later. */
1524                         rc = 0;
1525                         goto out_unlock;
1526                 }
1527                 sch_set_cdev(sch, NULL);
1528                 spin_unlock_irqrestore(sch->lock, flags);
1529                 /* Unregister ccw device. */
1530                 ccw_device_unregister(cdev);
1531                 break;
1532         default:
1533                 break;
1534         }
1535         /* Handle subchannel. */
1536         switch (action) {
1537         case IO_SCH_ORPH_UNREG:
1538         case IO_SCH_UNREG:
1539                 if (!cdev || !cdev->private->flags.resuming)
1540                         css_sch_device_unregister(sch);
1541                 break;
1542         case IO_SCH_ORPH_ATTACH:
1543         case IO_SCH_UNREG_ATTACH:
1544         case IO_SCH_ATTACH:
1545                 dev_id.ssid = sch->schid.ssid;
1546                 dev_id.devno = sch->schib.pmcw.dev;
1547                 cdev = get_ccwdev_by_dev_id(&dev_id);
1548                 if (!cdev) {
1549                         sch_create_and_recog_new_device(sch);
1550                         break;
1551                 }
1552                 rc = ccw_device_move_to_sch(cdev, sch);
1553                 if (rc) {
1554                         /* Release reference from get_ccwdev_by_dev_id() */
1555                         put_device(&cdev->dev);
1556                         goto out;
1557                 }
1558                 spin_lock_irqsave(sch->lock, flags);
1559                 ccw_device_trigger_reprobe(cdev);
1560                 spin_unlock_irqrestore(sch->lock, flags);
1561                 /* Release reference from get_ccwdev_by_dev_id() */
1562                 put_device(&cdev->dev);
1563                 break;
1564         default:
1565                 break;
1566         }
1567         return 0;
1568
1569 out_unlock:
1570         spin_unlock_irqrestore(sch->lock, flags);
1571 out:
1572         return rc;
1573 }
1574
1575 #ifdef CONFIG_CCW_CONSOLE
1576 static int ccw_device_console_enable(struct ccw_device *cdev,
1577                                      struct subchannel *sch)
1578 {
1579         int rc;
1580
1581         io_subchannel_init_fields(sch);
1582         rc = cio_commit_config(sch);
1583         if (rc)
1584                 return rc;
1585         sch->driver = &io_subchannel_driver;
1586         sch_set_cdev(sch, cdev);
1587         io_subchannel_recog(cdev, sch);
1588         /* Now wait for the async. recognition to come to an end. */
1589         spin_lock_irq(cdev->ccwlock);
1590         while (!dev_fsm_final_state(cdev))
1591                 ccw_device_wait_idle(cdev);
1592
1593         /* Hold on to an extra reference while device is online. */
1594         get_device(&cdev->dev);
1595         rc = ccw_device_online(cdev);
1596         if (rc)
1597                 goto out_unlock;
1598
1599         while (!dev_fsm_final_state(cdev))
1600                 ccw_device_wait_idle(cdev);
1601
1602         if (cdev->private->state == DEV_STATE_ONLINE)
1603                 cdev->online = 1;
1604         else
1605                 rc = -EIO;
1606 out_unlock:
1607         spin_unlock_irq(cdev->ccwlock);
1608         if (rc) /* Give up online reference since onlining failed. */
1609                 put_device(&cdev->dev);
1610         return rc;
1611 }
1612
1613 struct ccw_device *ccw_device_probe_console(void)
1614 {
1615         struct io_subchannel_private *io_priv;
1616         struct ccw_device *cdev;
1617         struct subchannel *sch;
1618         int ret;
1619
1620         sch = cio_probe_console();
1621         if (IS_ERR(sch))
1622                 return ERR_CAST(sch);
1623
1624         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1625         if (!io_priv) {
1626                 put_device(&sch->dev);
1627                 return ERR_PTR(-ENOMEM);
1628         }
1629         cdev = io_subchannel_create_ccwdev(sch);
1630         if (IS_ERR(cdev)) {
1631                 put_device(&sch->dev);
1632                 kfree(io_priv);
1633                 return cdev;
1634         }
1635         set_io_private(sch, io_priv);
1636         ret = ccw_device_console_enable(cdev, sch);
1637         if (ret) {
1638                 set_io_private(sch, NULL);
1639                 put_device(&sch->dev);
1640                 put_device(&cdev->dev);
1641                 kfree(io_priv);
1642                 return ERR_PTR(ret);
1643         }
1644         return cdev;
1645 }
1646
1647 /**
1648  * ccw_device_wait_idle() - busy wait for device to become idle
1649  * @cdev: ccw device
1650  *
1651  * Poll until activity control is zero, that is, no function or data
1652  * transfer is pending/active.
1653  * Called with device lock being held.
1654  */
1655 void ccw_device_wait_idle(struct ccw_device *cdev)
1656 {
1657         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1658
1659         while (1) {
1660                 cio_tsch(sch);
1661                 if (sch->schib.scsw.cmd.actl == 0)
1662                         break;
1663                 udelay_simple(100);
1664         }
1665 }
1666
1667 static int ccw_device_pm_restore(struct device *dev);
1668
1669 int ccw_device_force_console(struct ccw_device *cdev)
1670 {
1671         return ccw_device_pm_restore(&cdev->dev);
1672 }
1673 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1674 #endif
1675
1676 /*
1677  * get ccw_device matching the busid, but only if owned by cdrv
1678  */
1679 static int
1680 __ccwdev_check_busid(struct device *dev, void *id)
1681 {
1682         char *bus_id;
1683
1684         bus_id = id;
1685
1686         return (strcmp(bus_id, dev_name(dev)) == 0);
1687 }
1688
1689
1690 /**
1691  * get_ccwdev_by_busid() - obtain device from a bus id
1692  * @cdrv: driver the device is owned by
1693  * @bus_id: bus id of the device to be searched
1694  *
1695  * This function searches all devices owned by @cdrv for a device with a bus
1696  * id matching @bus_id.
1697  * Returns:
1698  *  If a match is found, its reference count of the found device is increased
1699  *  and it is returned; else %NULL is returned.
1700  */
1701 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1702                                        const char *bus_id)
1703 {
1704         struct device *dev;
1705
1706         dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
1707                                  __ccwdev_check_busid);
1708
1709         return dev ? to_ccwdev(dev) : NULL;
1710 }
1711
1712 /************************** device driver handling ************************/
1713
1714 /* This is the implementation of the ccw_driver class. The probe, remove
1715  * and release methods are initially very similar to the device_driver
1716  * implementations, with the difference that they have ccw_device
1717  * arguments.
1718  *
1719  * A ccw driver also contains the information that is needed for
1720  * device matching.
1721  */
1722 static int
1723 ccw_device_probe (struct device *dev)
1724 {
1725         struct ccw_device *cdev = to_ccwdev(dev);
1726         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1727         int ret;
1728
1729         cdev->drv = cdrv; /* to let the driver call _set_online */
1730         /* Note: we interpret class 0 in this context as an uninitialized
1731          * field since it translates to a non-I/O interrupt class. */
1732         if (cdrv->int_class != 0)
1733                 cdev->private->int_class = cdrv->int_class;
1734         else
1735                 cdev->private->int_class = IRQIO_CIO;
1736
1737         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1738
1739         if (ret) {
1740                 cdev->drv = NULL;
1741                 cdev->private->int_class = IRQIO_CIO;
1742                 return ret;
1743         }
1744
1745         return 0;
1746 }
1747
1748 static int
1749 ccw_device_remove (struct device *dev)
1750 {
1751         struct ccw_device *cdev = to_ccwdev(dev);
1752         struct ccw_driver *cdrv = cdev->drv;
1753         int ret;
1754
1755         if (cdrv->remove)
1756                 cdrv->remove(cdev);
1757         if (cdev->online) {
1758                 cdev->online = 0;
1759                 spin_lock_irq(cdev->ccwlock);
1760                 ret = ccw_device_offline(cdev);
1761                 spin_unlock_irq(cdev->ccwlock);
1762                 if (ret == 0)
1763                         wait_event(cdev->private->wait_q,
1764                                    dev_fsm_final_state(cdev));
1765                 else
1766                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1767                                       "device 0.%x.%04x\n",
1768                                       ret, cdev->private->dev_id.ssid,
1769                                       cdev->private->dev_id.devno);
1770                 /* Give up reference obtained in ccw_device_set_online(). */
1771                 put_device(&cdev->dev);
1772         }
1773         ccw_device_set_timeout(cdev, 0);
1774         cdev->drv = NULL;
1775         cdev->private->int_class = IRQIO_CIO;
1776         return 0;
1777 }
1778
1779 static void ccw_device_shutdown(struct device *dev)
1780 {
1781         struct ccw_device *cdev;
1782
1783         cdev = to_ccwdev(dev);
1784         if (cdev->drv && cdev->drv->shutdown)
1785                 cdev->drv->shutdown(cdev);
1786         disable_cmf(cdev);
1787 }
1788
1789 static int ccw_device_pm_prepare(struct device *dev)
1790 {
1791         struct ccw_device *cdev = to_ccwdev(dev);
1792
1793         if (work_pending(&cdev->private->todo_work))
1794                 return -EAGAIN;
1795         /* Fail while device is being set online/offline. */
1796         if (atomic_read(&cdev->private->onoff))
1797                 return -EAGAIN;
1798
1799         if (cdev->online && cdev->drv && cdev->drv->prepare)
1800                 return cdev->drv->prepare(cdev);
1801
1802         return 0;
1803 }
1804
1805 static void ccw_device_pm_complete(struct device *dev)
1806 {
1807         struct ccw_device *cdev = to_ccwdev(dev);
1808
1809         if (cdev->online && cdev->drv && cdev->drv->complete)
1810                 cdev->drv->complete(cdev);
1811 }
1812
1813 static int ccw_device_pm_freeze(struct device *dev)
1814 {
1815         struct ccw_device *cdev = to_ccwdev(dev);
1816         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1817         int ret, cm_enabled;
1818
1819         /* Fail suspend while device is in transistional state. */
1820         if (!dev_fsm_final_state(cdev))
1821                 return -EAGAIN;
1822         if (!cdev->online)
1823                 return 0;
1824         if (cdev->drv && cdev->drv->freeze) {
1825                 ret = cdev->drv->freeze(cdev);
1826                 if (ret)
1827                         return ret;
1828         }
1829
1830         spin_lock_irq(sch->lock);
1831         cm_enabled = cdev->private->cmb != NULL;
1832         spin_unlock_irq(sch->lock);
1833         if (cm_enabled) {
1834                 /* Don't have the css write on memory. */
1835                 ret = ccw_set_cmf(cdev, 0);
1836                 if (ret)
1837                         return ret;
1838         }
1839         /* From here on, disallow device driver I/O. */
1840         spin_lock_irq(sch->lock);
1841         ret = cio_disable_subchannel(sch);
1842         spin_unlock_irq(sch->lock);
1843
1844         return ret;
1845 }
1846
1847 static int ccw_device_pm_thaw(struct device *dev)
1848 {
1849         struct ccw_device *cdev = to_ccwdev(dev);
1850         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1851         int ret, cm_enabled;
1852
1853         if (!cdev->online)
1854                 return 0;
1855
1856         spin_lock_irq(sch->lock);
1857         /* Allow device driver I/O again. */
1858         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1859         cm_enabled = cdev->private->cmb != NULL;
1860         spin_unlock_irq(sch->lock);
1861         if (ret)
1862                 return ret;
1863
1864         if (cm_enabled) {
1865                 ret = ccw_set_cmf(cdev, 1);
1866                 if (ret)
1867                         return ret;
1868         }
1869
1870         if (cdev->drv && cdev->drv->thaw)
1871                 ret = cdev->drv->thaw(cdev);
1872
1873         return ret;
1874 }
1875
1876 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1877 {
1878         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1879
1880         spin_lock_irq(sch->lock);
1881         if (cio_is_console(sch->schid)) {
1882                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1883                 goto out_unlock;
1884         }
1885         /*
1886          * While we were sleeping, devices may have gone or become
1887          * available again. Kick re-detection.
1888          */
1889         cdev->private->flags.resuming = 1;
1890         cdev->private->path_new_mask = LPM_ANYPATH;
1891         css_sched_sch_todo(sch, SCH_TODO_EVAL);
1892         spin_unlock_irq(sch->lock);
1893         css_wait_for_slow_path();
1894
1895         /* cdev may have been moved to a different subchannel. */
1896         sch = to_subchannel(cdev->dev.parent);
1897         spin_lock_irq(sch->lock);
1898         if (cdev->private->state != DEV_STATE_ONLINE &&
1899             cdev->private->state != DEV_STATE_OFFLINE)
1900                 goto out_unlock;
1901
1902         ccw_device_recognition(cdev);
1903         spin_unlock_irq(sch->lock);
1904         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1905                    cdev->private->state == DEV_STATE_DISCONNECTED);
1906         spin_lock_irq(sch->lock);
1907
1908 out_unlock:
1909         cdev->private->flags.resuming = 0;
1910         spin_unlock_irq(sch->lock);
1911 }
1912
1913 static int resume_handle_boxed(struct ccw_device *cdev)
1914 {
1915         cdev->private->state = DEV_STATE_BOXED;
1916         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1917                 return 0;
1918         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1919         return -ENODEV;
1920 }
1921
1922 static int resume_handle_disc(struct ccw_device *cdev)
1923 {
1924         cdev->private->state = DEV_STATE_DISCONNECTED;
1925         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1926                 return 0;
1927         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1928         return -ENODEV;
1929 }
1930
1931 static int ccw_device_pm_restore(struct device *dev)
1932 {
1933         struct ccw_device *cdev = to_ccwdev(dev);
1934         struct subchannel *sch;
1935         int ret = 0;
1936
1937         __ccw_device_pm_restore(cdev);
1938         sch = to_subchannel(cdev->dev.parent);
1939         spin_lock_irq(sch->lock);
1940         if (cio_is_console(sch->schid))
1941                 goto out_restore;
1942
1943         /* check recognition results */
1944         switch (cdev->private->state) {
1945         case DEV_STATE_OFFLINE:
1946         case DEV_STATE_ONLINE:
1947                 cdev->private->flags.donotify = 0;
1948                 break;
1949         case DEV_STATE_BOXED:
1950                 ret = resume_handle_boxed(cdev);
1951                 if (ret)
1952                         goto out_unlock;
1953                 goto out_restore;
1954         default:
1955                 ret = resume_handle_disc(cdev);
1956                 if (ret)
1957                         goto out_unlock;
1958                 goto out_restore;
1959         }
1960         /* check if the device type has changed */
1961         if (!ccw_device_test_sense_data(cdev)) {
1962                 ccw_device_update_sense_data(cdev);
1963                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1964                 ret = -ENODEV;
1965                 goto out_unlock;
1966         }
1967         if (!cdev->online)
1968                 goto out_unlock;
1969
1970         if (ccw_device_online(cdev)) {
1971                 ret = resume_handle_disc(cdev);
1972                 if (ret)
1973                         goto out_unlock;
1974                 goto out_restore;
1975         }
1976         spin_unlock_irq(sch->lock);
1977         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1978         spin_lock_irq(sch->lock);
1979
1980         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1981                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1982                 ret = -ENODEV;
1983                 goto out_unlock;
1984         }
1985
1986         /* reenable cmf, if needed */
1987         if (cdev->private->cmb) {
1988                 spin_unlock_irq(sch->lock);
1989                 ret = ccw_set_cmf(cdev, 1);
1990                 spin_lock_irq(sch->lock);
1991                 if (ret) {
1992                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1993                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1994                                       cdev->private->dev_id.devno, ret);
1995                         ret = 0;
1996                 }
1997         }
1998
1999 out_restore:
2000         spin_unlock_irq(sch->lock);
2001         if (cdev->online && cdev->drv && cdev->drv->restore)
2002                 ret = cdev->drv->restore(cdev);
2003         return ret;
2004
2005 out_unlock:
2006         spin_unlock_irq(sch->lock);
2007         return ret;
2008 }
2009
2010 static const struct dev_pm_ops ccw_pm_ops = {
2011         .prepare = ccw_device_pm_prepare,
2012         .complete = ccw_device_pm_complete,
2013         .freeze = ccw_device_pm_freeze,
2014         .thaw = ccw_device_pm_thaw,
2015         .restore = ccw_device_pm_restore,
2016 };
2017
2018 static struct bus_type ccw_bus_type = {
2019         .name   = "ccw",
2020         .match  = ccw_bus_match,
2021         .uevent = ccw_uevent,
2022         .probe  = ccw_device_probe,
2023         .remove = ccw_device_remove,
2024         .shutdown = ccw_device_shutdown,
2025         .pm = &ccw_pm_ops,
2026 };
2027
2028 /**
2029  * ccw_driver_register() - register a ccw driver
2030  * @cdriver: driver to be registered
2031  *
2032  * This function is mainly a wrapper around driver_register().
2033  * Returns:
2034  *   %0 on success and a negative error value on failure.
2035  */
2036 int ccw_driver_register(struct ccw_driver *cdriver)
2037 {
2038         struct device_driver *drv = &cdriver->driver;
2039
2040         drv->bus = &ccw_bus_type;
2041
2042         return driver_register(drv);
2043 }
2044
2045 /**
2046  * ccw_driver_unregister() - deregister a ccw driver
2047  * @cdriver: driver to be deregistered
2048  *
2049  * This function is mainly a wrapper around driver_unregister().
2050  */
2051 void ccw_driver_unregister(struct ccw_driver *cdriver)
2052 {
2053         driver_unregister(&cdriver->driver);
2054 }
2055
2056 static void ccw_device_todo(struct work_struct *work)
2057 {
2058         struct ccw_device_private *priv;
2059         struct ccw_device *cdev;
2060         struct subchannel *sch;
2061         enum cdev_todo todo;
2062
2063         priv = container_of(work, struct ccw_device_private, todo_work);
2064         cdev = priv->cdev;
2065         sch = to_subchannel(cdev->dev.parent);
2066         /* Find out todo. */
2067         spin_lock_irq(cdev->ccwlock);
2068         todo = priv->todo;
2069         priv->todo = CDEV_TODO_NOTHING;
2070         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2071                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2072         spin_unlock_irq(cdev->ccwlock);
2073         /* Perform todo. */
2074         switch (todo) {
2075         case CDEV_TODO_ENABLE_CMF:
2076                 cmf_reenable(cdev);
2077                 break;
2078         case CDEV_TODO_REBIND:
2079                 ccw_device_do_unbind_bind(cdev);
2080                 break;
2081         case CDEV_TODO_REGISTER:
2082                 io_subchannel_register(cdev);
2083                 break;
2084         case CDEV_TODO_UNREG_EVAL:
2085                 if (!sch_is_pseudo_sch(sch))
2086                         css_schedule_eval(sch->schid);
2087                 /* fall-through */
2088         case CDEV_TODO_UNREG:
2089                 if (sch_is_pseudo_sch(sch))
2090                         ccw_device_unregister(cdev);
2091                 else
2092                         ccw_device_call_sch_unregister(cdev);
2093                 break;
2094         default:
2095                 break;
2096         }
2097         /* Release workqueue ref. */
2098         put_device(&cdev->dev);
2099 }
2100
2101 /**
2102  * ccw_device_sched_todo - schedule ccw device operation
2103  * @cdev: ccw device
2104  * @todo: todo
2105  *
2106  * Schedule the operation identified by @todo to be performed on the slow path
2107  * workqueue. Do nothing if another operation with higher priority is already
2108  * scheduled. Needs to be called with ccwdev lock held.
2109  */
2110 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2111 {
2112         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2113                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2114                       todo);
2115         if (cdev->private->todo >= todo)
2116                 return;
2117         cdev->private->todo = todo;
2118         /* Get workqueue ref. */
2119         if (!get_device(&cdev->dev))
2120                 return;
2121         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2122                 /* Already queued, release workqueue ref. */
2123                 put_device(&cdev->dev);
2124         }
2125 }
2126
2127 /**
2128  * ccw_device_siosl() - initiate logging
2129  * @cdev: ccw device
2130  *
2131  * This function is used to invoke model-dependent logging within the channel
2132  * subsystem.
2133  */
2134 int ccw_device_siosl(struct ccw_device *cdev)
2135 {
2136         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2137
2138         return chsc_siosl(sch->schid);
2139 }
2140 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2141
2142 MODULE_LICENSE("GPL");
2143 EXPORT_SYMBOL(ccw_device_set_online);
2144 EXPORT_SYMBOL(ccw_device_set_offline);
2145 EXPORT_SYMBOL(ccw_driver_register);
2146 EXPORT_SYMBOL(ccw_driver_unregister);
2147 EXPORT_SYMBOL(get_ccwdev_by_busid);