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   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002,2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/errno.h>
  14 #include <linux/err.h>
  15 #include <linux/slab.h>
  16 #include <linux/list.h>
  17 #include <linux/device.h>
  18 #include <linux/workqueue.h>
  19 #include <linux/timer.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24 #include <asm/cmb.h>
  25 #include <asm/isc.h>
  26
  27 #include "chp.h"
  28 #include "cio.h"
  29 #include "cio_debug.h"
  30 #include "css.h"
  31 #include "device.h"
  32 #include "ioasm.h"
  33 #include "io_sch.h"
  34 #include "blacklist.h"
  35
  36 static struct timer_list recovery_timer;
  37 static DEFINE_SPINLOCK(recovery_lock);
  38 static int recovery_phase;
  39 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  40
  41 /******************* bus type handling ***********************/
  42
  43 /* The Linux driver model distinguishes between a bus type and
  44  * the bus itself. Of course we only have one channel
  45  * subsystem driver and one channel system per machine, but
  46  * we still use the abstraction. T.R. says it's a good idea. */
  47 static int
  48 ccw_bus_match (struct device * dev, struct device_driver * drv)
  49 {
  50         struct ccw_device *cdev = to_ccwdev(dev);
  51         struct ccw_driver *cdrv = to_ccwdrv(drv);
  52         const struct ccw_device_id *ids = cdrv->ids, *found;
  53
  54         if (!ids)
  55                 return 0;
  56
  57         found = ccw_device_id_match(ids, &cdev->id);
  58         if (!found)
  59                 return 0;
  60
  61         cdev->id.driver_info = found->driver_info;
  62
  63         return 1;
  64 }
  65
  66 /* Store modalias string delimited by prefix/suffix string into buffer with
  67  * specified size. Return length of resulting string (excluding trailing '\0')
  68  * even if string doesn't fit buffer (snprintf semantics). */
  69 static int snprint_alias(char *buf, size_t size,
  70                          struct ccw_device_id *id, const char *suffix)
  71 {
  72         int len;
  73
  74         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  75         if (len > size)
  76                 return len;
  77         buf += len;
  78         size -= len;
  79
  80         if (id->dev_type != 0)
  81                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  82                                 id->dev_model, suffix);
  83         else
  84                 len += snprintf(buf, size, "dtdm%s", suffix);
  85
  86         return len;
  87 }
  88
  89 /* Set up environment variables for ccw device uevent. Return 0 on success,
  90  * non-zero otherwise. */
  91 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  92 {
  93         struct ccw_device *cdev = to_ccwdev(dev);
  94         struct ccw_device_id *id = &(cdev->id);
  95         int ret;
  96         char modalias_buf[30];
  97
  98         /* CU_TYPE= */
  99         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 100         if (ret)
 101                 return ret;
 102
 103         /* CU_MODEL= */
 104         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 105         if (ret)
 106                 return ret;
 107
 108         /* The next two can be zero, that's ok for us */
 109         /* DEV_TYPE= */
 110         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 111         if (ret)
 112                 return ret;
 113
 114         /* DEV_MODEL= */
 115         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 116         if (ret)
 117                 return ret;
 118
 119         /* MODALIAS=  */
 120         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 121         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 122         return ret;
 123 }
 124
 125 struct bus_type ccw_bus_type;
 126
 127 static void io_subchannel_irq(struct subchannel *);
 128 static int io_subchannel_probe(struct subchannel *);
 129 static int io_subchannel_remove(struct subchannel *);
 130 static void io_subchannel_shutdown(struct subchannel *);
 131 static int io_subchannel_sch_event(struct subchannel *, int);
 132 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 133                                    int);
 134 static void recovery_func(unsigned long data);
 135 struct workqueue_struct *ccw_device_work;
 136 wait_queue_head_t ccw_device_init_wq;
 137 atomic_t ccw_device_init_count;
 138
 139 static struct css_device_id io_subchannel_ids[] = {
 140         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 141         { /* end of list */ },
 142 };
 143 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 144
 145 static int io_subchannel_prepare(struct subchannel *sch)
 146 {
 147         struct ccw_device *cdev;
 148         /*
 149          * Don't allow suspend while a ccw device registration
 150          * is still outstanding.
 151          */
 152         cdev = sch_get_cdev(sch);
 153         if (cdev && !device_is_registered(&cdev->dev))
 154                 return -EAGAIN;
 155         return 0;
 156 }
 157
 158 static void io_subchannel_settle(void)
 159 {
 160         wait_event(ccw_device_init_wq,
 161                    atomic_read(&ccw_device_init_count) == 0);
 162         flush_workqueue(ccw_device_work);
 163 }
 164
 165 static struct css_driver io_subchannel_driver = {
 166         .owner = THIS_MODULE,
 167         .subchannel_type = io_subchannel_ids,
 168         .name = "io_subchannel",
 169         .irq = io_subchannel_irq,
 170         .sch_event = io_subchannel_sch_event,
 171         .chp_event = io_subchannel_chp_event,
 172         .probe = io_subchannel_probe,
 173         .remove = io_subchannel_remove,
 174         .shutdown = io_subchannel_shutdown,
 175         .prepare = io_subchannel_prepare,
 176         .settle = io_subchannel_settle,
 177 };
 178
 179 int __init io_subchannel_init(void)
 180 {
 181         int ret;
 182
 183         init_waitqueue_head(&ccw_device_init_wq);
 184         atomic_set(&ccw_device_init_count, 0);
 185         setup_timer(&recovery_timer, recovery_func, 0);
 186
 187         ccw_device_work = create_singlethread_workqueue("cio");
 188         if (!ccw_device_work)
 189                 return -ENOMEM;
 190         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 191         if (!slow_path_wq) {
 192                 ret = -ENOMEM;
 193                 goto out_err;
 194         }
 195         if ((ret = bus_register (&ccw_bus_type)))
 196                 goto out_err;
 197
 198         ret = css_driver_register(&io_subchannel_driver);
 199         if (ret)
 200                 goto out_err;
 201
 202         return 0;
 203 out_err:
 204         if (ccw_device_work)
 205                 destroy_workqueue(ccw_device_work);
 206         if (slow_path_wq)
 207                 destroy_workqueue(slow_path_wq);
 208         return ret;
 209 }
 210
 211
 212 /************************ device handling **************************/
 213
 214 /*
 215  * A ccw_device has some interfaces in sysfs in addition to the
 216  * standard ones.
 217  * The following entries are designed to export the information which
 218  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 219  * are obvious, so they don't have an entry :)
 220  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 221  */
 222 static ssize_t
 223 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 224 {
 225         struct subchannel *sch = to_subchannel(dev);
 226         struct chsc_ssd_info *ssd = &sch->ssd_info;
 227         ssize_t ret = 0;
 228         int chp;
 229         int mask;
 230
 231         for (chp = 0; chp < 8; chp++) {
 232                 mask = 0x80 >> chp;
 233                 if (ssd->path_mask & mask)
 234                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 235                 else
 236                         ret += sprintf(buf + ret, "00 ");
 237         }
 238         ret += sprintf (buf+ret, "\n");
 239         return min((ssize_t)PAGE_SIZE, ret);
 240 }
 241
 242 static ssize_t
 243 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 244 {
 245         struct subchannel *sch = to_subchannel(dev);
 246         struct pmcw *pmcw = &sch->schib.pmcw;
 247
 248         return sprintf (buf, "%02x %02x %02x\n",
 249                         pmcw->pim, pmcw->pam, pmcw->pom);
 250 }
 251
 252 static ssize_t
 253 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 254 {
 255         struct ccw_device *cdev = to_ccwdev(dev);
 256         struct ccw_device_id *id = &(cdev->id);
 257
 258         if (id->dev_type != 0)
 259                 return sprintf(buf, "%04x/%02x\n",
 260                                 id->dev_type, id->dev_model);
 261         else
 262                 return sprintf(buf, "n/a\n");
 263 }
 264
 265 static ssize_t
 266 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 267 {
 268         struct ccw_device *cdev = to_ccwdev(dev);
 269         struct ccw_device_id *id = &(cdev->id);
 270
 271         return sprintf(buf, "%04x/%02x\n",
 272                        id->cu_type, id->cu_model);
 273 }
 274
 275 static ssize_t
 276 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 277 {
 278         struct ccw_device *cdev = to_ccwdev(dev);
 279         struct ccw_device_id *id = &(cdev->id);
 280         int len;
 281
 282         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 283
 284         return len > PAGE_SIZE ? PAGE_SIZE : len;
 285 }
 286
 287 static ssize_t
 288 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 289 {
 290         struct ccw_device *cdev = to_ccwdev(dev);
 291
 292         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 293 }
 294
 295 int ccw_device_is_orphan(struct ccw_device *cdev)
 296 {
 297         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 298 }
 299
 300 static void ccw_device_unregister(struct ccw_device *cdev)
 301 {
 302         if (test_and_clear_bit(1, &cdev->private->registered)) {
 303                 device_del(&cdev->dev);
 304                 /* Release reference from device_initialize(). */
 305                 put_device(&cdev->dev);
 306         }
 307 }
 308
 309 static void ccw_device_remove_orphan_cb(struct work_struct *work)
 310 {
 311         struct ccw_device_private *priv;
 312         struct ccw_device *cdev;
 313
 314         priv = container_of(work, struct ccw_device_private, kick_work);
 315         cdev = priv->cdev;
 316         ccw_device_unregister(cdev);
 317         /* Release cdev reference for workqueue processing. */
 318         put_device(&cdev->dev);
 319 }
 320
 321 static void
 322 ccw_device_remove_disconnected(struct ccw_device *cdev)
 323 {
 324         unsigned long flags;
 325
 326         /*
 327          * Forced offline in disconnected state means
 328          * 'throw away device'.
 329          */
 330         if (ccw_device_is_orphan(cdev)) {
 331                 /*
 332                  * Deregister ccw device.
 333                  * Unfortunately, we cannot do this directly from the
 334                  * attribute method.
 335                  */
 336                 /* Get cdev reference for workqueue processing. */
 337                 if (!get_device(&cdev->dev))
 338                         return;
 339                 spin_lock_irqsave(cdev->ccwlock, flags);
 340                 cdev->private->state = DEV_STATE_NOT_OPER;
 341                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 342                 PREPARE_WORK(&cdev->private->kick_work,
 343                                 ccw_device_remove_orphan_cb);
 344                 queue_work(slow_path_wq, &cdev->private->kick_work);
 345         } else
 346                 /* Deregister subchannel, which will kill the ccw device. */
 347                 ccw_device_schedule_sch_unregister(cdev);
 348 }
 349
 350 /**
 351  * ccw_device_set_offline() - disable a ccw device for I/O
 352  * @cdev: target ccw device
 353  *
 354  * This function calls the driver's set_offline() function for @cdev, if
 355  * given, and then disables @cdev.
 356  * Returns:
 357  *   %0 on success and a negative error value on failure.
 358  * Context:
 359  *  enabled, ccw device lock not held
 360  */
 361 int ccw_device_set_offline(struct ccw_device *cdev)
 362 {
 363         int ret;
 364
 365         if (!cdev)
 366                 return -ENODEV;
 367         if (!cdev->online || !cdev->drv)
 368                 return -EINVAL;
 369
 370         if (cdev->drv->set_offline) {
 371                 ret = cdev->drv->set_offline(cdev);
 372                 if (ret != 0)
 373                         return ret;
 374         }
 375         cdev->online = 0;
 376         spin_lock_irq(cdev->ccwlock);
 377         /* Wait until a final state or DISCONNECTED is reached */
 378         while (!dev_fsm_final_state(cdev) &&
 379                cdev->private->state != DEV_STATE_DISCONNECTED) {
 380                 spin_unlock_irq(cdev->ccwlock);
 381                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 382                            cdev->private->state == DEV_STATE_DISCONNECTED));
 383                 spin_lock_irq(cdev->ccwlock);
 384         }
 385         ret = ccw_device_offline(cdev);
 386         if (ret)
 387                 goto error;
 388         spin_unlock_irq(cdev->ccwlock);
 389         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 390                    cdev->private->state == DEV_STATE_DISCONNECTED));
 391         /* Give up reference from ccw_device_set_online(). */
 392         put_device(&cdev->dev);
 393         return 0;
 394
 395 error:
 396         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device 0.%x.%04x\n",
 397                       ret, cdev->private->dev_id.ssid,
 398                       cdev->private->dev_id.devno);
 399         cdev->private->state = DEV_STATE_OFFLINE;
 400         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 401         spin_unlock_irq(cdev->ccwlock);
 402         /* Give up reference from ccw_device_set_online(). */
 403         put_device(&cdev->dev);
 404         return -ENODEV;
 405 }
 406
 407 /**
 408  * ccw_device_set_online() - enable a ccw device for I/O
 409  * @cdev: target ccw device
 410  *
 411  * This function first enables @cdev and then calls the driver's set_online()
 412  * function for @cdev, if given. If set_online() returns an error, @cdev is
 413  * disabled again.
 414  * Returns:
 415  *   %0 on success and a negative error value on failure.
 416  * Context:
 417  *  enabled, ccw device lock not held
 418  */
 419 int ccw_device_set_online(struct ccw_device *cdev)
 420 {
 421         int ret;
 422         int ret2;
 423
 424         if (!cdev)
 425                 return -ENODEV;
 426         if (cdev->online || !cdev->drv)
 427                 return -EINVAL;
 428         /* Hold on to an extra reference while device is online. */
 429         if (!get_device(&cdev->dev))
 430                 return -ENODEV;
 431
 432         spin_lock_irq(cdev->ccwlock);
 433         ret = ccw_device_online(cdev);
 434         spin_unlock_irq(cdev->ccwlock);
 435         if (ret == 0)
 436                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 437         else {
 438                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 439                               "device 0.%x.%04x\n",
 440                               ret, cdev->private->dev_id.ssid,
 441                               cdev->private->dev_id.devno);
 442                 /* Give up online reference since onlining failed. */
 443                 put_device(&cdev->dev);
 444                 return ret;
 445         }
 446         spin_lock_irq(cdev->ccwlock);
 447         /* Check if online processing was successful */
 448         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 449             (cdev->private->state != DEV_STATE_W4SENSE)) {
 450                 spin_unlock_irq(cdev->ccwlock);
 451                 /* Give up online reference since onlining failed. */
 452                 put_device(&cdev->dev);
 453                 return -ENODEV;
 454         }
 455         spin_unlock_irq(cdev->ccwlock);
 456         if (cdev->drv->set_online)
 457                 ret = cdev->drv->set_online(cdev);
 458         if (ret)
 459                 goto rollback;
 460         cdev->online = 1;
 461         return 0;
 462
 463 rollback:
 464         spin_lock_irq(cdev->ccwlock);
 465         /* Wait until a final state or DISCONNECTED is reached */
 466         while (!dev_fsm_final_state(cdev) &&
 467                cdev->private->state != DEV_STATE_DISCONNECTED) {
 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                 spin_lock_irq(cdev->ccwlock);
 472         }
 473         ret2 = ccw_device_offline(cdev);
 474         if (ret2)
 475                 goto error;
 476         spin_unlock_irq(cdev->ccwlock);
 477         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 478                    cdev->private->state == DEV_STATE_DISCONNECTED));
 479         /* Give up online reference since onlining failed. */
 480         put_device(&cdev->dev);
 481         return ret;
 482
 483 error:
 484         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 485                       "device 0.%x.%04x\n",
 486                       ret2, cdev->private->dev_id.ssid,
 487                       cdev->private->dev_id.devno);
 488         cdev->private->state = DEV_STATE_OFFLINE;
 489         spin_unlock_irq(cdev->ccwlock);
 490         /* Give up online reference since onlining failed. */
 491         put_device(&cdev->dev);
 492         return ret;
 493 }
 494
 495 static int online_store_handle_offline(struct ccw_device *cdev)
 496 {
 497         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 498                 ccw_device_remove_disconnected(cdev);
 499         else if (cdev->online && cdev->drv && cdev->drv->set_offline)
 500                 return ccw_device_set_offline(cdev);
 501         return 0;
 502 }
 503
 504 static int online_store_recog_and_online(struct ccw_device *cdev)
 505 {
 506         int ret;
 507
 508         /* Do device recognition, if needed. */
 509         if (cdev->private->state == DEV_STATE_BOXED) {
 510                 ret = ccw_device_recognition(cdev);
 511                 if (ret) {
 512                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 513                                       "for device 0.%x.%04x (ret=%d)\n",
 514                                       cdev->private->dev_id.ssid,
 515                                       cdev->private->dev_id.devno, ret);
 516                         return ret;
 517                 }
 518                 wait_event(cdev->private->wait_q,
 519                            cdev->private->flags.recog_done);
 520                 if (cdev->private->state != DEV_STATE_OFFLINE)
 521                         /* recognition failed */
 522                         return -EAGAIN;
 523         }
 524         if (cdev->drv && cdev->drv->set_online)
 525                 ccw_device_set_online(cdev);
 526         return 0;
 527 }
 528
 529 static int online_store_handle_online(struct ccw_device *cdev, int force)
 530 {
 531         int ret;
 532
 533         ret = online_store_recog_and_online(cdev);
 534         if (ret && !force)
 535                 return ret;
 536         if (force && cdev->private->state == DEV_STATE_BOXED) {
 537                 ret = ccw_device_stlck(cdev);
 538                 if (ret)
 539                         return ret;
 540                 if (cdev->id.cu_type == 0)
 541                         cdev->private->state = DEV_STATE_NOT_OPER;
 542                 ret = online_store_recog_and_online(cdev);
 543                 if (ret)
 544                         return ret;
 545         }
 546         return 0;
 547 }
 548
 549 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 550                              const char *buf, size_t count)
 551 {
 552         struct ccw_device *cdev = to_ccwdev(dev);
 553         int force, ret;
 554         unsigned long i;
 555
 556         if ((cdev->private->state != DEV_STATE_OFFLINE &&
 557              cdev->private->state != DEV_STATE_ONLINE &&
 558              cdev->private->state != DEV_STATE_BOXED &&
 559              cdev->private->state != DEV_STATE_DISCONNECTED) ||
 560             atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 561                 return -EAGAIN;
 562
 563         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 564                 atomic_set(&cdev->private->onoff, 0);
 565                 return -EINVAL;
 566         }
 567         if (!strncmp(buf, "force\n", count)) {
 568                 force = 1;
 569                 i = 1;
 570                 ret = 0;
 571         } else {
 572                 force = 0;
 573                 ret = strict_strtoul(buf, 16, &i);
 574         }
 575         if (ret)
 576                 goto out;
 577         switch (i) {
 578         case 0:
 579                 ret = online_store_handle_offline(cdev);
 580                 break;
 581         case 1:
 582                 ret = online_store_handle_online(cdev, force);
 583                 break;
 584         default:
 585                 ret = -EINVAL;
 586         }
 587 out:
 588         if (cdev->drv)
 589                 module_put(cdev->drv->owner);
 590         atomic_set(&cdev->private->onoff, 0);
 591         return (ret < 0) ? ret : count;
 592 }
 593
 594 static ssize_t
 595 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 596 {
 597         struct ccw_device *cdev = to_ccwdev(dev);
 598         struct subchannel *sch;
 599
 600         if (ccw_device_is_orphan(cdev))
 601                 return sprintf(buf, "no device\n");
 602         switch (cdev->private->state) {
 603         case DEV_STATE_BOXED:
 604                 return sprintf(buf, "boxed\n");
 605         case DEV_STATE_DISCONNECTED:
 606         case DEV_STATE_DISCONNECTED_SENSE_ID:
 607         case DEV_STATE_NOT_OPER:
 608                 sch = to_subchannel(dev->parent);
 609                 if (!sch->lpm)
 610                         return sprintf(buf, "no path\n");
 611                 else
 612                         return sprintf(buf, "no device\n");
 613         default:
 614                 /* All other states considered fine. */
 615                 return sprintf(buf, "good\n");
 616         }
 617 }
 618
 619 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 620 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 621 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 622 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 623 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 624 static DEVICE_ATTR(online, 0644, online_show, online_store);
 625 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 626
 627 static struct attribute *io_subchannel_attrs[] = {
 628         &dev_attr_chpids.attr,
 629         &dev_attr_pimpampom.attr,
 630         NULL,
 631 };
 632
 633 static struct attribute_group io_subchannel_attr_group = {
 634         .attrs = io_subchannel_attrs,
 635 };
 636
 637 static struct attribute * ccwdev_attrs[] = {
 638         &dev_attr_devtype.attr,
 639         &dev_attr_cutype.attr,
 640         &dev_attr_modalias.attr,
 641         &dev_attr_online.attr,
 642         &dev_attr_cmb_enable.attr,
 643         &dev_attr_availability.attr,
 644         NULL,
 645 };
 646
 647 static struct attribute_group ccwdev_attr_group = {
 648         .attrs = ccwdev_attrs,
 649 };
 650
 651 static const struct attribute_group *ccwdev_attr_groups[] = {
 652         &ccwdev_attr_group,
 653         NULL,
 654 };
 655
 656 /* this is a simple abstraction for device_register that sets the
 657  * correct bus type and adds the bus specific files */
 658 static int ccw_device_register(struct ccw_device *cdev)
 659 {
 660         struct device *dev = &cdev->dev;
 661         int ret;
 662
 663         dev->bus = &ccw_bus_type;
 664         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 665                            cdev->private->dev_id.devno);
 666         if (ret)
 667                 return ret;
 668         ret = device_add(dev);
 669         if (ret)
 670                 return ret;
 671
 672         set_bit(1, &cdev->private->registered);
 673         return ret;
 674 }
 675
 676 struct match_data {
 677         struct ccw_dev_id dev_id;
 678         struct ccw_device * sibling;
 679 };
 680
 681 static int
 682 match_devno(struct device * dev, void * data)
 683 {
 684         struct match_data * d = data;
 685         struct ccw_device * cdev;
 686
 687         cdev = to_ccwdev(dev);
 688         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 689             !ccw_device_is_orphan(cdev) &&
 690             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 691             (cdev != d->sibling))
 692                 return 1;
 693         return 0;
 694 }
 695
 696 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 697                                                      struct ccw_device *sibling)
 698 {
 699         struct device *dev;
 700         struct match_data data;
 701
 702         data.dev_id = *dev_id;
 703         data.sibling = sibling;
 704         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 705
 706         return dev ? to_ccwdev(dev) : NULL;
 707 }
 708
 709 static int match_orphan(struct device *dev, void *data)
 710 {
 711         struct ccw_dev_id *dev_id;
 712         struct ccw_device *cdev;
 713
 714         dev_id = data;
 715         cdev = to_ccwdev(dev);
 716         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 717 }
 718
 719 static struct ccw_device *
 720 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 721                               struct ccw_dev_id *dev_id)
 722 {
 723         struct device *dev;
 724
 725         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 726                                 match_orphan);
 727
 728         return dev ? to_ccwdev(dev) : NULL;
 729 }
 730
 731 void ccw_device_do_unbind_bind(struct work_struct *work)
 732 {
 733         struct ccw_device_private *priv;
 734         struct ccw_device *cdev;
 735         struct subchannel *sch;
 736         int ret;
 737
 738         priv = container_of(work, struct ccw_device_private, kick_work);
 739         cdev = priv->cdev;
 740         sch = to_subchannel(cdev->dev.parent);
 741
 742         if (test_bit(1, &cdev->private->registered)) {
 743                 device_release_driver(&cdev->dev);
 744                 ret = device_attach(&cdev->dev);
 745                 WARN_ON(ret == -ENODEV);
 746         }
 747 }
 748
 749 static void
 750 ccw_device_release(struct device *dev)
 751 {
 752         struct ccw_device *cdev;
 753
 754         cdev = to_ccwdev(dev);
 755         /* Release reference of parent subchannel. */
 756         put_device(cdev->dev.parent);
 757         kfree(cdev->private);
 758         kfree(cdev);
 759 }
 760
 761 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 762 {
 763         struct ccw_device *cdev;
 764
 765         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 766         if (cdev) {
 767                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 768                                         GFP_KERNEL | GFP_DMA);
 769                 if (cdev->private)
 770                         return cdev;
 771         }
 772         kfree(cdev);
 773         return ERR_PTR(-ENOMEM);
 774 }
 775
 776 static int io_subchannel_initialize_dev(struct subchannel *sch,
 777                                         struct ccw_device *cdev)
 778 {
 779         cdev->private->cdev = cdev;
 780         atomic_set(&cdev->private->onoff, 0);
 781         cdev->dev.parent = &sch->dev;
 782         cdev->dev.release = ccw_device_release;
 783         INIT_WORK(&cdev->private->kick_work, NULL);
 784         cdev->dev.groups = ccwdev_attr_groups;
 785         /* Do first half of device_register. */
 786         device_initialize(&cdev->dev);
 787         if (!get_device(&sch->dev)) {
 788                 /* Release reference from device_initialize(). */
 789                 put_device(&cdev->dev);
 790                 return -ENODEV;
 791         }
 792         return 0;
 793 }
 794
 795 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 796 {
 797         struct ccw_device *cdev;
 798         int ret;
 799
 800         cdev = io_subchannel_allocate_dev(sch);
 801         if (!IS_ERR(cdev)) {
 802                 ret = io_subchannel_initialize_dev(sch, cdev);
 803                 if (ret)
 804                         cdev = ERR_PTR(ret);
 805         }
 806         return cdev;
 807 }
 808
 809 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 810
 811 static void sch_attach_device(struct subchannel *sch,
 812                               struct ccw_device *cdev)
 813 {
 814         css_update_ssd_info(sch);
 815         spin_lock_irq(sch->lock);
 816         sch_set_cdev(sch, cdev);
 817         cdev->private->schid = sch->schid;
 818         cdev->ccwlock = sch->lock;
 819         ccw_device_trigger_reprobe(cdev);
 820         spin_unlock_irq(sch->lock);
 821 }
 822
 823 static void sch_attach_disconnected_device(struct subchannel *sch,
 824                                            struct ccw_device *cdev)
 825 {
 826         struct subchannel *other_sch;
 827         int ret;
 828
 829         /* Get reference for new parent. */
 830         if (!get_device(&sch->dev))
 831                 return;
 832         other_sch = to_subchannel(cdev->dev.parent);
 833         /* Note: device_move() changes cdev->dev.parent */
 834         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 835         if (ret) {
 836                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 837                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 838                               cdev->private->dev_id.devno, ret);
 839                 /* Put reference for new parent. */
 840                 put_device(&sch->dev);
 841                 return;
 842         }
 843         sch_set_cdev(other_sch, NULL);
 844         /* No need to keep a subchannel without ccw device around. */
 845         css_sch_device_unregister(other_sch);
 846         sch_attach_device(sch, cdev);
 847         /* Put reference for old parent. */
 848         put_device(&other_sch->dev);
 849 }
 850
 851 static void sch_attach_orphaned_device(struct subchannel *sch,
 852                                        struct ccw_device *cdev)
 853 {
 854         int ret;
 855         struct subchannel *pseudo_sch;
 856
 857         /* Get reference for new parent. */
 858         if (!get_device(&sch->dev))
 859                 return;
 860         pseudo_sch = to_subchannel(cdev->dev.parent);
 861         /*
 862          * Try to move the ccw device to its new subchannel.
 863          * Note: device_move() changes cdev->dev.parent
 864          */
 865         ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 866         if (ret) {
 867                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 868                               "failed (ret=%d)!\n",
 869                               cdev->private->dev_id.ssid,
 870                               cdev->private->dev_id.devno, ret);
 871                 /* Put reference for new parent. */
 872                 put_device(&sch->dev);
 873                 return;
 874         }
 875         sch_attach_device(sch, cdev);
 876         /* Put reference on pseudo subchannel. */
 877         put_device(&pseudo_sch->dev);
 878 }
 879
 880 static void sch_create_and_recog_new_device(struct subchannel *sch)
 881 {
 882         struct ccw_device *cdev;
 883
 884         /* Need to allocate a new ccw device. */
 885         cdev = io_subchannel_create_ccwdev(sch);
 886         if (IS_ERR(cdev)) {
 887                 /* OK, we did everything we could... */
 888                 css_sch_device_unregister(sch);
 889                 return;
 890         }
 891         spin_lock_irq(sch->lock);
 892         sch_set_cdev(sch, cdev);
 893         spin_unlock_irq(sch->lock);
 894         /* Start recognition for the new ccw device. */
 895         if (io_subchannel_recog(cdev, sch)) {
 896                 spin_lock_irq(sch->lock);
 897                 sch_set_cdev(sch, NULL);
 898                 spin_unlock_irq(sch->lock);
 899                 css_sch_device_unregister(sch);
 900                 /* Put reference from io_subchannel_create_ccwdev(). */
 901                 put_device(&sch->dev);
 902                 /* Give up initial reference. */
 903                 put_device(&cdev->dev);
 904         }
 905 }
 906
 907
 908 void ccw_device_move_to_orphanage(struct work_struct *work)
 909 {
 910         struct ccw_device_private *priv;
 911         struct ccw_device *cdev;
 912         struct ccw_device *replacing_cdev;
 913         struct subchannel *sch;
 914         int ret;
 915         struct channel_subsystem *css;
 916         struct ccw_dev_id dev_id;
 917
 918         priv = container_of(work, struct ccw_device_private, kick_work);
 919         cdev = priv->cdev;
 920         sch = to_subchannel(cdev->dev.parent);
 921         css = to_css(sch->dev.parent);
 922         dev_id.devno = sch->schib.pmcw.dev;
 923         dev_id.ssid = sch->schid.ssid;
 924
 925         /* Increase refcount for pseudo subchannel. */
 926         get_device(&css->pseudo_subchannel->dev);
 927         /*
 928          * Move the orphaned ccw device to the orphanage so the replacing
 929          * ccw device can take its place on the subchannel.
 930          * Note: device_move() changes cdev->dev.parent
 931          */
 932         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev,
 933                 DPM_ORDER_NONE);
 934         if (ret) {
 935                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 936                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 937                               cdev->private->dev_id.devno, ret);
 938                 /* Decrease refcount for pseudo subchannel again. */
 939                 put_device(&css->pseudo_subchannel->dev);
 940                 return;
 941         }
 942         cdev->ccwlock = css->pseudo_subchannel->lock;
 943         /*
 944          * Search for the replacing ccw device
 945          * - among the disconnected devices
 946          * - in the orphanage
 947          */
 948         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 949         if (replacing_cdev) {
 950                 sch_attach_disconnected_device(sch, replacing_cdev);
 951                 /* Release reference from get_disc_ccwdev_by_dev_id() */
 952                 put_device(&replacing_cdev->dev);
 953                 /* Release reference of subchannel from old cdev. */
 954                 put_device(&sch->dev);
 955                 return;
 956         }
 957         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 958         if (replacing_cdev) {
 959                 sch_attach_orphaned_device(sch, replacing_cdev);
 960                 /* Release reference from get_orphaned_ccwdev_by_dev_id() */
 961                 put_device(&replacing_cdev->dev);
 962                 /* Release reference of subchannel from old cdev. */
 963                 put_device(&sch->dev);
 964                 return;
 965         }
 966         sch_create_and_recog_new_device(sch);
 967         /* Release reference of subchannel from old cdev. */
 968         put_device(&sch->dev);
 969 }
 970
 971 /*
 972  * Register recognized device.
 973  */
 974 static void
 975 io_subchannel_register(struct work_struct *work)
 976 {
 977         struct ccw_device_private *priv;
 978         struct ccw_device *cdev;
 979         struct subchannel *sch;
 980         int ret;
 981         unsigned long flags;
 982
 983         priv = container_of(work, struct ccw_device_private, kick_work);
 984         cdev = priv->cdev;
 985         sch = to_subchannel(cdev->dev.parent);
 986         /*
 987          * Check if subchannel is still registered. It may have become
 988          * unregistered if a machine check hit us after finishing
 989          * device recognition but before the register work could be
 990          * queued.
 991          */
 992         if (!device_is_registered(&sch->dev))
 993                 goto out_err;
 994         css_update_ssd_info(sch);
 995         /*
 996          * io_subchannel_register() will also be called after device
 997          * recognition has been done for a boxed device (which will already
 998          * be registered). We need to reprobe since we may now have sense id
 999          * information.
1000          */
1001         if (device_is_registered(&cdev->dev)) {
1002                 if (!cdev->drv) {
1003                         ret = device_reprobe(&cdev->dev);
1004                         if (ret)
1005                                 /* We can't do much here. */
1006                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
1007                                               " %d for 0.%x.%04x\n", ret,
1008                                               cdev->private->dev_id.ssid,
1009                                               cdev->private->dev_id.devno);
1010                 }
1011                 goto out;
1012         }
1013         /*
1014          * Now we know this subchannel will stay, we can throw
1015          * our delayed uevent.
1016          */
1017         dev_set_uevent_suppress(&sch->dev, 0);
1018         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1019         /* make it known to the system */
1020         ret = ccw_device_register(cdev);
1021         if (ret) {
1022                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
1023                               cdev->private->dev_id.ssid,
1024                               cdev->private->dev_id.devno, ret);
1025                 spin_lock_irqsave(sch->lock, flags);
1026                 sch_set_cdev(sch, NULL);
1027                 spin_unlock_irqrestore(sch->lock, flags);
1028                 /* Release initial device reference. */
1029                 put_device(&cdev->dev);
1030                 goto out_err;
1031         }
1032 out:
1033         cdev->private->flags.recog_done = 1;
1034         wake_up(&cdev->private->wait_q);
1035 out_err:
1036         /* Release reference for workqueue processing. */
1037         put_device(&cdev->dev);
1038         if (atomic_dec_and_test(&ccw_device_init_count))
1039                 wake_up(&ccw_device_init_wq);
1040 }
1041
1042 static void ccw_device_call_sch_unregister(struct work_struct *work)
1043 {
1044         struct ccw_device_private *priv;
1045         struct ccw_device *cdev;
1046         struct subchannel *sch;
1047
1048         priv = container_of(work, struct ccw_device_private, kick_work);
1049         cdev = priv->cdev;
1050         /* Get subchannel reference for local processing. */
1051         if (!get_device(cdev->dev.parent))
1052                 return;
1053         sch = to_subchannel(cdev->dev.parent);
1054         css_sch_device_unregister(sch);
1055         /* Release cdev reference for workqueue processing.*/
1056         put_device(&cdev->dev);
1057         /* Release subchannel reference for local processing. */
1058         put_device(&sch->dev);
1059 }
1060
1061 void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
1062 {
1063         /* Get cdev reference for workqueue processing. */
1064         if (!get_device(&cdev->dev))
1065                 return;
1066         PREPARE_WORK(&cdev->private->kick_work,
1067                      ccw_device_call_sch_unregister);
1068         queue_work(slow_path_wq, &cdev->private->kick_work);
1069 }
1070
1071 /*
1072  * subchannel recognition done. Called from the state machine.
1073  */
1074 void
1075 io_subchannel_recog_done(struct ccw_device *cdev)
1076 {
1077         if (css_init_done == 0) {
1078                 cdev->private->flags.recog_done = 1;
1079                 return;
1080         }
1081         switch (cdev->private->state) {
1082         case DEV_STATE_BOXED:
1083                 /* Device did not respond in time. */
1084         case DEV_STATE_NOT_OPER:
1085                 cdev->private->flags.recog_done = 1;
1086                 ccw_device_schedule_sch_unregister(cdev);
1087                 if (atomic_dec_and_test(&ccw_device_init_count))
1088                         wake_up(&ccw_device_init_wq);
1089                 break;
1090         case DEV_STATE_OFFLINE:
1091                 /*
1092                  * We can't register the device in interrupt context so
1093                  * we schedule a work item.
1094                  */
1095                 if (!get_device(&cdev->dev))
1096                         break;
1097                 PREPARE_WORK(&cdev->private->kick_work,
1098                              io_subchannel_register);
1099                 queue_work(slow_path_wq, &cdev->private->kick_work);
1100                 break;
1101         }
1102 }
1103
1104 static int
1105 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1106 {
1107         int rc;
1108         struct ccw_device_private *priv;
1109
1110         sch_set_cdev(sch, cdev);
1111         cdev->ccwlock = sch->lock;
1112
1113         /* Init private data. */
1114         priv = cdev->private;
1115         priv->dev_id.devno = sch->schib.pmcw.dev;
1116         priv->dev_id.ssid = sch->schid.ssid;
1117         priv->schid = sch->schid;
1118         priv->state = DEV_STATE_NOT_OPER;
1119         INIT_LIST_HEAD(&priv->cmb_list);
1120         init_waitqueue_head(&priv->wait_q);
1121         init_timer(&priv->timer);
1122
1123         /* Increase counter of devices currently in recognition. */
1124         atomic_inc(&ccw_device_init_count);
1125
1126         /* Start async. device sensing. */
1127         spin_lock_irq(sch->lock);
1128         rc = ccw_device_recognition(cdev);
1129         spin_unlock_irq(sch->lock);
1130         if (rc) {
1131                 if (atomic_dec_and_test(&ccw_device_init_count))
1132                         wake_up(&ccw_device_init_wq);
1133         }
1134         return rc;
1135 }
1136
1137 static void ccw_device_move_to_sch(struct work_struct *work)
1138 {
1139         struct ccw_device_private *priv;
1140         int rc;
1141         struct subchannel *sch;
1142         struct ccw_device *cdev;
1143         struct subchannel *former_parent;
1144
1145         priv = container_of(work, struct ccw_device_private, kick_work);
1146         sch = priv->sch;
1147         cdev = priv->cdev;
1148         former_parent = to_subchannel(cdev->dev.parent);
1149         /* Get reference for new parent. */
1150         if (!get_device(&sch->dev))
1151                 return;
1152         mutex_lock(&sch->reg_mutex);
1153         /*
1154          * Try to move the ccw device to its new subchannel.
1155          * Note: device_move() changes cdev->dev.parent
1156          */
1157         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
1158         mutex_unlock(&sch->reg_mutex);
1159         if (rc) {
1160                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1161                               "0.%x.%04x failed (ret=%d)!\n",
1162                               cdev->private->dev_id.ssid,
1163                               cdev->private->dev_id.devno, sch->schid.ssid,
1164                               sch->schid.sch_no, rc);
1165                 css_sch_device_unregister(sch);
1166                 /* Put reference for new parent again. */
1167                 put_device(&sch->dev);
1168                 goto out;
1169         }
1170         if (!sch_is_pseudo_sch(former_parent)) {
1171                 spin_lock_irq(former_parent->lock);
1172                 sch_set_cdev(former_parent, NULL);
1173                 spin_unlock_irq(former_parent->lock);
1174                 css_sch_device_unregister(former_parent);
1175                 /* Reset intparm to zeroes. */
1176                 former_parent->config.intparm = 0;
1177                 cio_commit_config(former_parent);
1178         }
1179         sch_attach_device(sch, cdev);
1180 out:
1181         /* Put reference for old parent. */
1182         put_device(&former_parent->dev);
1183         put_device(&cdev->dev);
1184 }
1185
1186 static void io_subchannel_irq(struct subchannel *sch)
1187 {
1188         struct ccw_device *cdev;
1189
1190         cdev = sch_get_cdev(sch);
1191
1192         CIO_TRACE_EVENT(6, "IRQ");
1193         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1194         if (cdev)
1195                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1196 }
1197
1198 void io_subchannel_init_config(struct subchannel *sch)
1199 {
1200         memset(&sch->config, 0, sizeof(sch->config));
1201         sch->config.csense = 1;
1202         /* Use subchannel mp mode when there is more than 1 installed CHPID. */
1203         if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
1204                 sch->config.mp = 1;
1205 }
1206
1207 static void io_subchannel_init_fields(struct subchannel *sch)
1208 {
1209         if (cio_is_console(sch->schid))
1210                 sch->opm = 0xff;
1211         else
1212                 sch->opm = chp_get_sch_opm(sch);
1213         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1214         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1215
1216         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1217                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1218                       sch->schib.pmcw.dev, sch->schid.ssid,
1219                       sch->schid.sch_no, sch->schib.pmcw.pim,
1220                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1221
1222         io_subchannel_init_config(sch);
1223 }
1224
1225 static void io_subchannel_do_unreg(struct work_struct *work)
1226 {
1227         struct subchannel *sch;
1228
1229         sch = container_of(work, struct subchannel, work);
1230         css_sch_device_unregister(sch);
1231         put_device(&sch->dev);
1232 }
1233
1234 /* Schedule unregister if we have no cdev. */
1235 static void io_subchannel_schedule_removal(struct subchannel *sch)
1236 {
1237         get_device(&sch->dev);
1238         INIT_WORK(&sch->work, io_subchannel_do_unreg);
1239         queue_work(slow_path_wq, &sch->work);
1240 }
1241
1242 /*
1243  * Note: We always return 0 so that we bind to the device even on error.
1244  * This is needed so that our remove function is called on unregister.
1245  */
1246 static int io_subchannel_probe(struct subchannel *sch)
1247 {
1248         struct ccw_device *cdev;
1249         int rc;
1250         unsigned long flags;
1251         struct ccw_dev_id dev_id;
1252
1253         if (cio_is_console(sch->schid)) {
1254                 rc = sysfs_create_group(&sch->dev.kobj,
1255                                         &io_subchannel_attr_group);
1256                 if (rc)
1257                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1258                                       "attributes for subchannel "
1259                                       "0.%x.%04x (rc=%d)\n",
1260                                       sch->schid.ssid, sch->schid.sch_no, rc);
1261                 /*
1262                  * The console subchannel already has an associated ccw_device.
1263                  * Throw the delayed uevent for the subchannel, register
1264                  * the ccw_device and exit.
1265                  */
1266                 dev_set_uevent_suppress(&sch->dev, 0);
1267                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1268                 cdev = sch_get_cdev(sch);
1269                 cdev->dev.groups = ccwdev_attr_groups;
1270                 device_initialize(&cdev->dev);
1271                 ccw_device_register(cdev);
1272                 /*
1273                  * Check if the device is already online. If it is
1274                  * the reference count needs to be corrected since we
1275                  * didn't obtain a reference in ccw_device_set_online.
1276                  */
1277                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1278                     cdev->private->state != DEV_STATE_OFFLINE &&
1279                     cdev->private->state != DEV_STATE_BOXED)
1280                         get_device(&cdev->dev);
1281                 return 0;
1282         }
1283         io_subchannel_init_fields(sch);
1284         rc = cio_commit_config(sch);
1285         if (rc)
1286                 goto out_schedule;
1287         rc = sysfs_create_group(&sch->dev.kobj,
1288                                 &io_subchannel_attr_group);
1289         if (rc)
1290                 goto out_schedule;
1291         /* Allocate I/O subchannel private data. */
1292         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1293                                GFP_KERNEL | GFP_DMA);
1294         if (!sch->private)
1295                 goto out_err;
1296         /*
1297          * First check if a fitting device may be found amongst the
1298          * disconnected devices or in the orphanage.
1299          */
1300         dev_id.devno = sch->schib.pmcw.dev;
1301         dev_id.ssid = sch->schid.ssid;
1302         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1303         if (!cdev)
1304                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1305                                                      &dev_id);
1306         if (cdev) {
1307                 /*
1308                  * Schedule moving the device until when we have a registered
1309                  * subchannel to move to and succeed the probe. We can
1310                  * unregister later again, when the probe is through.
1311                  */
1312                 cdev->private->sch = sch;
1313                 PREPARE_WORK(&cdev->private->kick_work,
1314                              ccw_device_move_to_sch);
1315                 queue_work(slow_path_wq, &cdev->private->kick_work);
1316                 return 0;
1317         }
1318         cdev = io_subchannel_create_ccwdev(sch);
1319         if (IS_ERR(cdev))
1320                 goto out_err;
1321         rc = io_subchannel_recog(cdev, sch);
1322         if (rc) {
1323                 spin_lock_irqsave(sch->lock, flags);
1324                 io_subchannel_recog_done(cdev);
1325                 spin_unlock_irqrestore(sch->lock, flags);
1326         }
1327         return 0;
1328 out_err:
1329         kfree(sch->private);
1330         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1331 out_schedule:
1332         io_subchannel_schedule_removal(sch);
1333         return 0;
1334 }
1335
1336 static int
1337 io_subchannel_remove (struct subchannel *sch)
1338 {
1339         struct ccw_device *cdev;
1340         unsigned long flags;
1341
1342         cdev = sch_get_cdev(sch);
1343         if (!cdev)
1344                 return 0;
1345         /* Set ccw device to not operational and drop reference. */
1346         spin_lock_irqsave(cdev->ccwlock, flags);
1347         sch_set_cdev(sch, NULL);
1348         cdev->private->state = DEV_STATE_NOT_OPER;
1349         spin_unlock_irqrestore(cdev->ccwlock, flags);
1350         ccw_device_unregister(cdev);
1351         kfree(sch->private);
1352         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1353         return 0;
1354 }
1355
1356 static int io_subchannel_notify(struct subchannel *sch, int event)
1357 {
1358         struct ccw_device *cdev;
1359
1360         cdev = sch_get_cdev(sch);
1361         if (!cdev)
1362                 return 0;
1363         return ccw_device_notify(cdev, event);
1364 }
1365
1366 static void io_subchannel_verify(struct subchannel *sch)
1367 {
1368         struct ccw_device *cdev;
1369
1370         cdev = sch_get_cdev(sch);
1371         if (cdev)
1372                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1373 }
1374
1375 static int check_for_io_on_path(struct subchannel *sch, int mask)
1376 {
1377         if (cio_update_schib(sch))
1378                 return 0;
1379         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1380                 return 1;
1381         return 0;
1382 }
1383
1384 static void terminate_internal_io(struct subchannel *sch,
1385                                   struct ccw_device *cdev)
1386 {
1387         if (cio_clear(sch)) {
1388                 /* Recheck device in case clear failed. */
1389                 sch->lpm = 0;
1390                 if (cdev->online)
1391                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1392                 else
1393                         css_schedule_eval(sch->schid);
1394                 return;
1395         }
1396         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1397         /* Request retry of internal operation. */
1398         cdev->private->flags.intretry = 1;
1399         /* Call handler. */
1400         if (cdev->handler)
1401                 cdev->handler(cdev, cdev->private->intparm,
1402                               ERR_PTR(-EIO));
1403 }
1404
1405 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1406 {
1407         struct ccw_device *cdev;
1408
1409         cdev = sch_get_cdev(sch);
1410         if (!cdev)
1411                 return;
1412         if (check_for_io_on_path(sch, mask)) {
1413                 if (cdev->private->state == DEV_STATE_ONLINE)
1414                         ccw_device_kill_io(cdev);
1415                 else {
1416                         terminate_internal_io(sch, cdev);
1417                         /* Re-start path verification. */
1418                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1419                 }
1420         } else
1421                 /* trigger path verification. */
1422                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1423
1424 }
1425
1426 static int io_subchannel_chp_event(struct subchannel *sch,
1427                                    struct chp_link *link, int event)
1428 {
1429         int mask;
1430
1431         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1432         if (!mask)
1433                 return 0;
1434         switch (event) {
1435         case CHP_VARY_OFF:
1436                 sch->opm &= ~mask;
1437                 sch->lpm &= ~mask;
1438                 io_subchannel_terminate_path(sch, mask);
1439                 break;
1440         case CHP_VARY_ON:
1441                 sch->opm |= mask;
1442                 sch->lpm |= mask;
1443                 io_subchannel_verify(sch);
1444                 break;
1445         case CHP_OFFLINE:
1446                 if (cio_update_schib(sch))
1447                         return -ENODEV;
1448                 io_subchannel_terminate_path(sch, mask);
1449                 break;
1450         case CHP_ONLINE:
1451                 if (cio_update_schib(sch))
1452                         return -ENODEV;
1453                 sch->lpm |= mask & sch->opm;
1454                 io_subchannel_verify(sch);
1455                 break;
1456         }
1457         return 0;
1458 }
1459
1460 static void
1461 io_subchannel_shutdown(struct subchannel *sch)
1462 {
1463         struct ccw_device *cdev;
1464         int ret;
1465
1466         cdev = sch_get_cdev(sch);
1467
1468         if (cio_is_console(sch->schid))
1469                 return;
1470         if (!sch->schib.pmcw.ena)
1471                 /* Nothing to do. */
1472                 return;
1473         ret = cio_disable_subchannel(sch);
1474         if (ret != -EBUSY)
1475                 /* Subchannel is disabled, we're done. */
1476                 return;
1477         cdev->private->state = DEV_STATE_QUIESCE;
1478         if (cdev->handler)
1479                 cdev->handler(cdev, cdev->private->intparm,
1480                               ERR_PTR(-EIO));
1481         ret = ccw_device_cancel_halt_clear(cdev);
1482         if (ret == -EBUSY) {
1483                 ccw_device_set_timeout(cdev, HZ/10);
1484                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1485         }
1486         cio_disable_subchannel(sch);
1487 }
1488
1489 static int io_subchannel_get_status(struct subchannel *sch)
1490 {
1491         struct schib schib;
1492
1493         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1494                 return CIO_GONE;
1495         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1496                 return CIO_REVALIDATE;
1497         if (!sch->lpm)
1498                 return CIO_NO_PATH;
1499         return CIO_OPER;
1500 }
1501
1502 static int device_is_disconnected(struct ccw_device *cdev)
1503 {
1504         if (!cdev)
1505                 return 0;
1506         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1507                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1508 }
1509
1510 static int recovery_check(struct device *dev, void *data)
1511 {
1512         struct ccw_device *cdev = to_ccwdev(dev);
1513         int *redo = data;
1514
1515         spin_lock_irq(cdev->ccwlock);
1516         switch (cdev->private->state) {
1517         case DEV_STATE_DISCONNECTED:
1518                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1519                               cdev->private->dev_id.ssid,
1520                               cdev->private->dev_id.devno);
1521                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1522                 *redo = 1;
1523                 break;
1524         case DEV_STATE_DISCONNECTED_SENSE_ID:
1525                 *redo = 1;
1526                 break;
1527         }
1528         spin_unlock_irq(cdev->ccwlock);
1529
1530         return 0;
1531 }
1532
1533 static void recovery_work_func(struct work_struct *unused)
1534 {
1535         int redo = 0;
1536
1537         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1538         if (redo) {
1539                 spin_lock_irq(&recovery_lock);
1540                 if (!timer_pending(&recovery_timer)) {
1541                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1542                                 recovery_phase++;
1543                         mod_timer(&recovery_timer, jiffies +
1544                                   recovery_delay[recovery_phase] * HZ);
1545                 }
1546                 spin_unlock_irq(&recovery_lock);
1547         } else
1548                 CIO_MSG_EVENT(4, "recovery: end\n");
1549 }
1550
1551 static DECLARE_WORK(recovery_work, recovery_work_func);
1552
1553 static void recovery_func(unsigned long data)
1554 {
1555         /*
1556          * We can't do our recovery in softirq context and it's not
1557          * performance critical, so we schedule it.
1558          */
1559         schedule_work(&recovery_work);
1560 }
1561
1562 static void ccw_device_schedule_recovery(void)
1563 {
1564         unsigned long flags;
1565
1566         CIO_MSG_EVENT(4, "recovery: schedule\n");
1567         spin_lock_irqsave(&recovery_lock, flags);
1568         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1569                 recovery_phase = 0;
1570                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1571         }
1572         spin_unlock_irqrestore(&recovery_lock, flags);
1573 }
1574
1575 static int purge_fn(struct device *dev, void *data)
1576 {
1577         struct ccw_device *cdev = to_ccwdev(dev);
1578         struct ccw_device_private *priv = cdev->private;
1579         int unreg;
1580
1581         spin_lock_irq(cdev->ccwlock);
1582         unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1583                 (priv->state == DEV_STATE_OFFLINE);
1584         spin_unlock_irq(cdev->ccwlock);
1585         if (!unreg)
1586                 goto out;
1587         CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1588                       priv->dev_id.devno);
1589         ccw_device_schedule_sch_unregister(cdev);
1590
1591 out:
1592         /* Abort loop in case of pending signal. */
1593         if (signal_pending(current))
1594                 return -EINTR;
1595
1596         return 0;
1597 }
1598
1599 /**
1600  * ccw_purge_blacklisted - purge unused, blacklisted devices
1601  *
1602  * Unregister all ccw devices that are offline and on the blacklist.
1603  */
1604 int ccw_purge_blacklisted(void)
1605 {
1606         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1607         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1608         return 0;
1609 }
1610
1611 void ccw_device_set_disconnected(struct ccw_device *cdev)
1612 {
1613         if (!cdev)
1614                 return;
1615         ccw_device_set_timeout(cdev, 0);
1616         cdev->private->flags.fake_irb = 0;
1617         cdev->private->state = DEV_STATE_DISCONNECTED;
1618         if (cdev->online)
1619                 ccw_device_schedule_recovery();
1620 }
1621
1622 void ccw_device_set_notoper(struct ccw_device *cdev)
1623 {
1624         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1625
1626         CIO_TRACE_EVENT(2, "notoper");
1627         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1628         ccw_device_set_timeout(cdev, 0);
1629         cio_disable_subchannel(sch);
1630         cdev->private->state = DEV_STATE_NOT_OPER;
1631 }
1632
1633 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1634 {
1635         int event, ret, disc;
1636         unsigned long flags;
1637         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1638         struct ccw_device *cdev;
1639
1640         spin_lock_irqsave(sch->lock, flags);
1641         cdev = sch_get_cdev(sch);
1642         disc = device_is_disconnected(cdev);
1643         if (disc && slow) {
1644                 /* Disconnected devices are evaluated directly only.*/
1645                 spin_unlock_irqrestore(sch->lock, flags);
1646                 return 0;
1647         }
1648         /* No interrupt after machine check - kill pending timers. */
1649         if (cdev)
1650                 ccw_device_set_timeout(cdev, 0);
1651         if (!disc && !slow) {
1652                 /* Non-disconnected devices are evaluated on the slow path. */
1653                 spin_unlock_irqrestore(sch->lock, flags);
1654                 return -EAGAIN;
1655         }
1656         event = io_subchannel_get_status(sch);
1657         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1658                       sch->schid.ssid, sch->schid.sch_no, event,
1659                       disc ? "disconnected" : "normal",
1660                       slow ? "slow" : "fast");
1661         /* Analyze subchannel status. */
1662         action = NONE;
1663         switch (event) {
1664         case CIO_NO_PATH:
1665                 if (disc) {
1666                         /* Check if paths have become available. */
1667                         action = REPROBE;
1668                         break;
1669                 }
1670                 /* fall through */
1671         case CIO_GONE:
1672                 /* Ask driver what to do with device. */
1673                 if (io_subchannel_notify(sch, event))
1674                         action = DISC;
1675                 else
1676                         action = UNREGISTER;
1677                 break;
1678         case CIO_REVALIDATE:
1679                 /* Device will be removed, so no notify necessary. */
1680                 if (disc)
1681                         /* Reprobe because immediate unregister might block. */
1682                         action = REPROBE;
1683                 else
1684                         action = UNREGISTER_PROBE;
1685                 break;
1686         case CIO_OPER:
1687                 if (disc)
1688                         /* Get device operational again. */
1689                         action = REPROBE;
1690                 break;
1691         }
1692         /* Perform action. */
1693         ret = 0;
1694         switch (action) {
1695         case UNREGISTER:
1696         case UNREGISTER_PROBE:
1697                 ccw_device_set_notoper(cdev);
1698                 /* Unregister device (will use subchannel lock). */
1699                 spin_unlock_irqrestore(sch->lock, flags);
1700                 css_sch_device_unregister(sch);
1701                 spin_lock_irqsave(sch->lock, flags);
1702                 break;
1703         case REPROBE:
1704                 ccw_device_trigger_reprobe(cdev);
1705                 break;
1706         case DISC:
1707                 ccw_device_set_disconnected(cdev);
1708                 break;
1709         default:
1710                 break;
1711         }
1712         spin_unlock_irqrestore(sch->lock, flags);
1713         /* Probe if necessary. */
1714         if (action == UNREGISTER_PROBE)
1715                 ret = css_probe_device(sch->schid);
1716
1717         return ret;
1718 }
1719
1720 #ifdef CONFIG_CCW_CONSOLE
1721 static struct ccw_device console_cdev;
1722 static struct ccw_device_private console_private;
1723 static int console_cdev_in_use;
1724
1725 static DEFINE_SPINLOCK(ccw_console_lock);
1726
1727 spinlock_t * cio_get_console_lock(void)
1728 {
1729         return &ccw_console_lock;
1730 }
1731
1732 static int ccw_device_console_enable(struct ccw_device *cdev,
1733                                      struct subchannel *sch)
1734 {
1735         int rc;
1736
1737         /* Attach subchannel private data. */
1738         sch->private = cio_get_console_priv();
1739         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1740         io_subchannel_init_fields(sch);
1741         rc = cio_commit_config(sch);
1742         if (rc)
1743                 return rc;
1744         sch->driver = &io_subchannel_driver;
1745         /* Initialize the ccw_device structure. */
1746         cdev->dev.parent= &sch->dev;
1747         rc = io_subchannel_recog(cdev, sch);
1748         if (rc)
1749                 return rc;
1750
1751         /* Now wait for the async. recognition to come to an end. */
1752         spin_lock_irq(cdev->ccwlock);
1753         while (!dev_fsm_final_state(cdev))
1754                 wait_cons_dev();
1755         rc = -EIO;
1756         if (cdev->private->state != DEV_STATE_OFFLINE)
1757                 goto out_unlock;
1758         ccw_device_online(cdev);
1759         while (!dev_fsm_final_state(cdev))
1760                 wait_cons_dev();
1761         if (cdev->private->state != DEV_STATE_ONLINE)
1762                 goto out_unlock;
1763         rc = 0;
1764 out_unlock:
1765         spin_unlock_irq(cdev->ccwlock);
1766         return 0;
1767 }
1768
1769 struct ccw_device *
1770 ccw_device_probe_console(void)
1771 {
1772         struct subchannel *sch;
1773         int ret;
1774
1775         if (xchg(&console_cdev_in_use, 1) != 0)
1776                 return ERR_PTR(-EBUSY);
1777         sch = cio_probe_console();
1778         if (IS_ERR(sch)) {
1779                 console_cdev_in_use = 0;
1780                 return (void *) sch;
1781         }
1782         memset(&console_cdev, 0, sizeof(struct ccw_device));
1783         memset(&console_private, 0, sizeof(struct ccw_device_private));
1784         console_cdev.private = &console_private;
1785         console_private.cdev = &console_cdev;
1786         ret = ccw_device_console_enable(&console_cdev, sch);
1787         if (ret) {
1788                 cio_release_console();
1789                 console_cdev_in_use = 0;
1790                 return ERR_PTR(ret);
1791         }
1792         console_cdev.online = 1;
1793         return &console_cdev;
1794 }
1795
1796 static int ccw_device_pm_restore(struct device *dev);
1797
1798 int ccw_device_force_console(void)
1799 {
1800         if (!console_cdev_in_use)
1801                 return -ENODEV;
1802         return ccw_device_pm_restore(&console_cdev.dev);
1803 }
1804 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1805 #endif
1806
1807 /*
1808  * get ccw_device matching the busid, but only if owned by cdrv
1809  */
1810 static int
1811 __ccwdev_check_busid(struct device *dev, void *id)
1812 {
1813         char *bus_id;
1814
1815         bus_id = id;
1816
1817         return (strcmp(bus_id, dev_name(dev)) == 0);
1818 }
1819
1820
1821 /**
1822  * get_ccwdev_by_busid() - obtain device from a bus id
1823  * @cdrv: driver the device is owned by
1824  * @bus_id: bus id of the device to be searched
1825  *
1826  * This function searches all devices owned by @cdrv for a device with a bus
1827  * id matching @bus_id.
1828  * Returns:
1829  *  If a match is found, its reference count of the found device is increased
1830  *  and it is returned; else %NULL is returned.
1831  */
1832 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1833                                        const char *bus_id)
1834 {
1835         struct device *dev;
1836         struct device_driver *drv;
1837
1838         drv = get_driver(&cdrv->driver);
1839         if (!drv)
1840                 return NULL;
1841
1842         dev = driver_find_device(drv, NULL, (void *)bus_id,
1843                                  __ccwdev_check_busid);
1844         put_driver(drv);
1845
1846         return dev ? to_ccwdev(dev) : NULL;
1847 }
1848
1849 /************************** device driver handling ************************/
1850
1851 /* This is the implementation of the ccw_driver class. The probe, remove
1852  * and release methods are initially very similar to the device_driver
1853  * implementations, with the difference that they have ccw_device
1854  * arguments.
1855  *
1856  * A ccw driver also contains the information that is needed for
1857  * device matching.
1858  */
1859 static int
1860 ccw_device_probe (struct device *dev)
1861 {
1862         struct ccw_device *cdev = to_ccwdev(dev);
1863         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1864         int ret;
1865
1866         cdev->drv = cdrv; /* to let the driver call _set_online */
1867
1868         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1869
1870         if (ret) {
1871                 cdev->drv = NULL;
1872                 return ret;
1873         }
1874
1875         return 0;
1876 }
1877
1878 static int
1879 ccw_device_remove (struct device *dev)
1880 {
1881         struct ccw_device *cdev = to_ccwdev(dev);
1882         struct ccw_driver *cdrv = cdev->drv;
1883         int ret;
1884
1885         if (cdrv->remove)
1886                 cdrv->remove(cdev);
1887         if (cdev->online) {
1888                 cdev->online = 0;
1889                 spin_lock_irq(cdev->ccwlock);
1890                 ret = ccw_device_offline(cdev);
1891                 spin_unlock_irq(cdev->ccwlock);
1892                 if (ret == 0)
1893                         wait_event(cdev->private->wait_q,
1894                                    dev_fsm_final_state(cdev));
1895                 else
1896                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1897                                       "device 0.%x.%04x\n",
1898                                       ret, cdev->private->dev_id.ssid,
1899                                       cdev->private->dev_id.devno);
1900                 /* Give up reference obtained in ccw_device_set_online(). */
1901                 put_device(&cdev->dev);
1902         }
1903         ccw_device_set_timeout(cdev, 0);
1904         cdev->drv = NULL;
1905         return 0;
1906 }
1907
1908 static void ccw_device_shutdown(struct device *dev)
1909 {
1910         struct ccw_device *cdev;
1911
1912         cdev = to_ccwdev(dev);
1913         if (cdev->drv && cdev->drv->shutdown)
1914                 cdev->drv->shutdown(cdev);
1915         disable_cmf(cdev);
1916 }
1917
1918 static int ccw_device_pm_prepare(struct device *dev)
1919 {
1920         struct ccw_device *cdev = to_ccwdev(dev);
1921
1922         if (work_pending(&cdev->private->kick_work))
1923                 return -EAGAIN;
1924         /* Fail while device is being set online/offline. */
1925         if (atomic_read(&cdev->private->onoff))
1926                 return -EAGAIN;
1927
1928         if (cdev->online && cdev->drv && cdev->drv->prepare)
1929                 return cdev->drv->prepare(cdev);
1930
1931         return 0;
1932 }
1933
1934 static void ccw_device_pm_complete(struct device *dev)
1935 {
1936         struct ccw_device *cdev = to_ccwdev(dev);
1937
1938         if (cdev->online && cdev->drv && cdev->drv->complete)
1939                 cdev->drv->complete(cdev);
1940 }
1941
1942 static int ccw_device_pm_freeze(struct device *dev)
1943 {
1944         struct ccw_device *cdev = to_ccwdev(dev);
1945         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1946         int ret, cm_enabled;
1947
1948         /* Fail suspend while device is in transistional state. */
1949         if (!dev_fsm_final_state(cdev))
1950                 return -EAGAIN;
1951         if (!cdev->online)
1952                 return 0;
1953         if (cdev->drv && cdev->drv->freeze) {
1954                 ret = cdev->drv->freeze(cdev);
1955                 if (ret)
1956                         return ret;
1957         }
1958
1959         spin_lock_irq(sch->lock);
1960         cm_enabled = cdev->private->cmb != NULL;
1961         spin_unlock_irq(sch->lock);
1962         if (cm_enabled) {
1963                 /* Don't have the css write on memory. */
1964                 ret = ccw_set_cmf(cdev, 0);
1965                 if (ret)
1966                         return ret;
1967         }
1968         /* From here on, disallow device driver I/O. */
1969         spin_lock_irq(sch->lock);
1970         ret = cio_disable_subchannel(sch);
1971         spin_unlock_irq(sch->lock);
1972
1973         return ret;
1974 }
1975
1976 static int ccw_device_pm_thaw(struct device *dev)
1977 {
1978         struct ccw_device *cdev = to_ccwdev(dev);
1979         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1980         int ret, cm_enabled;
1981
1982         if (!cdev->online)
1983                 return 0;
1984
1985         spin_lock_irq(sch->lock);
1986         /* Allow device driver I/O again. */
1987         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1988         cm_enabled = cdev->private->cmb != NULL;
1989         spin_unlock_irq(sch->lock);
1990         if (ret)
1991                 return ret;
1992
1993         if (cm_enabled) {
1994                 ret = ccw_set_cmf(cdev, 1);
1995                 if (ret)
1996                         return ret;
1997         }
1998
1999         if (cdev->drv && cdev->drv->thaw)
2000                 ret = cdev->drv->thaw(cdev);
2001
2002         return ret;
2003 }
2004
2005 static void __ccw_device_pm_restore(struct ccw_device *cdev)
2006 {
2007         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2008         int ret;
2009
2010         if (cio_is_console(sch->schid))
2011                 goto out;
2012         /*
2013          * While we were sleeping, devices may have gone or become
2014          * available again. Kick re-detection.
2015          */
2016         spin_lock_irq(sch->lock);
2017         cdev->private->flags.resuming = 1;
2018         ret = ccw_device_recognition(cdev);
2019         spin_unlock_irq(sch->lock);
2020         if (ret) {
2021                 CIO_MSG_EVENT(0, "Couldn't start recognition for device "
2022                               "0.%x.%04x (ret=%d)\n",
2023                               cdev->private->dev_id.ssid,
2024                               cdev->private->dev_id.devno, ret);
2025                 spin_lock_irq(sch->lock);
2026                 cdev->private->state = DEV_STATE_DISCONNECTED;
2027                 spin_unlock_irq(sch->lock);
2028                 /* notify driver after the resume cb */
2029                 goto out;
2030         }
2031         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
2032                    cdev->private->state == DEV_STATE_DISCONNECTED);
2033
2034 out:
2035         cdev->private->flags.resuming = 0;
2036 }
2037
2038 static int resume_handle_boxed(struct ccw_device *cdev)
2039 {
2040         cdev->private->state = DEV_STATE_BOXED;
2041         if (ccw_device_notify(cdev, CIO_BOXED))
2042                 return 0;
2043         ccw_device_schedule_sch_unregister(cdev);
2044         return -ENODEV;
2045 }
2046
2047 static int resume_handle_disc(struct ccw_device *cdev)
2048 {
2049         cdev->private->state = DEV_STATE_DISCONNECTED;
2050         if (ccw_device_notify(cdev, CIO_GONE))
2051                 return 0;
2052         ccw_device_schedule_sch_unregister(cdev);
2053         return -ENODEV;
2054 }
2055
2056 static int ccw_device_pm_restore(struct device *dev)
2057 {
2058         struct ccw_device *cdev = to_ccwdev(dev);
2059         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2060         int ret = 0, cm_enabled;
2061
2062         __ccw_device_pm_restore(cdev);
2063         spin_lock_irq(sch->lock);
2064         if (cio_is_console(sch->schid)) {
2065                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
2066                 spin_unlock_irq(sch->lock);
2067                 goto out_restore;
2068         }
2069         cdev->private->flags.donotify = 0;
2070         /* check recognition results */
2071         switch (cdev->private->state) {
2072         case DEV_STATE_OFFLINE:
2073                 break;
2074         case DEV_STATE_BOXED:
2075                 ret = resume_handle_boxed(cdev);
2076                 spin_unlock_irq(sch->lock);
2077                 if (ret)
2078                         goto out;
2079                 goto out_restore;
2080         case DEV_STATE_DISCONNECTED:
2081                 goto out_disc_unlock;
2082         default:
2083                 goto out_unreg_unlock;
2084         }
2085         /* check if the device id has changed */
2086         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
2087                 CIO_MSG_EVENT(0, "resume: sch 0.%x.%04x: failed (devno "
2088                               "changed from %04x to %04x)\n",
2089                               sch->schid.ssid, sch->schid.sch_no,
2090                               cdev->private->dev_id.devno,
2091                               sch->schib.pmcw.dev);
2092                 goto out_unreg_unlock;
2093         }
2094         /* check if the device type has changed */
2095         if (!ccw_device_test_sense_data(cdev)) {
2096                 ccw_device_update_sense_data(cdev);
2097                 PREPARE_WORK(&cdev->private->kick_work,
2098                              ccw_device_do_unbind_bind);
2099                 queue_work(ccw_device_work, &cdev->private->kick_work);
2100                 ret = -ENODEV;
2101                 goto out_unlock;
2102         }
2103         if (!cdev->online) {
2104                 ret = 0;
2105                 goto out_unlock;
2106         }
2107         ret = ccw_device_online(cdev);
2108         if (ret)
2109                 goto out_disc_unlock;
2110
2111         cm_enabled = cdev->private->cmb != NULL;
2112         spin_unlock_irq(sch->lock);
2113
2114         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
2115         if (cdev->private->state != DEV_STATE_ONLINE) {
2116                 spin_lock_irq(sch->lock);
2117                 goto out_disc_unlock;
2118         }
2119         if (cm_enabled) {
2120                 ret = ccw_set_cmf(cdev, 1);
2121                 if (ret) {
2122                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
2123                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
2124                                       cdev->private->dev_id.devno, ret);
2125                         ret = 0;
2126                 }
2127         }
2128
2129 out_restore:
2130         if (cdev->online && cdev->drv && cdev->drv->restore)
2131                 ret = cdev->drv->restore(cdev);
2132 out:
2133         return ret;
2134
2135 out_disc_unlock:
2136         ret = resume_handle_disc(cdev);
2137         spin_unlock_irq(sch->lock);
2138         if (ret)
2139                 return ret;
2140         goto out_restore;
2141
2142 out_unreg_unlock:
2143         ccw_device_schedule_sch_unregister(cdev);
2144         ret = -ENODEV;
2145 out_unlock:
2146         spin_unlock_irq(sch->lock);
2147         return ret;
2148 }
2149
2150 static struct dev_pm_ops ccw_pm_ops = {
2151         .prepare = ccw_device_pm_prepare,
2152         .complete = ccw_device_pm_complete,
2153         .freeze = ccw_device_pm_freeze,
2154         .thaw = ccw_device_pm_thaw,
2155         .restore = ccw_device_pm_restore,
2156 };
2157
2158 struct bus_type ccw_bus_type = {
2159         .name   = "ccw",
2160         .match  = ccw_bus_match,
2161         .uevent = ccw_uevent,
2162         .probe  = ccw_device_probe,
2163         .remove = ccw_device_remove,
2164         .shutdown = ccw_device_shutdown,
2165         .pm = &ccw_pm_ops,
2166 };
2167
2168 /**
2169  * ccw_driver_register() - register a ccw driver
2170  * @cdriver: driver to be registered
2171  *
2172  * This function is mainly a wrapper around driver_register().
2173  * Returns:
2174  *   %0 on success and a negative error value on failure.
2175  */
2176 int ccw_driver_register(struct ccw_driver *cdriver)
2177 {
2178         struct device_driver *drv = &cdriver->driver;
2179
2180         drv->bus = &ccw_bus_type;
2181         drv->name = cdriver->name;
2182         drv->owner = cdriver->owner;
2183
2184         return driver_register(drv);
2185 }
2186
2187 /**
2188  * ccw_driver_unregister() - deregister a ccw driver
2189  * @cdriver: driver to be deregistered
2190  *
2191  * This function is mainly a wrapper around driver_unregister().
2192  */
2193 void ccw_driver_unregister(struct ccw_driver *cdriver)
2194 {
2195         driver_unregister(&cdriver->driver);
2196 }
2197
2198 /* Helper func for qdio. */
2199 struct subchannel_id
2200 ccw_device_get_subchannel_id(struct ccw_device *cdev)
2201 {
2202         struct subchannel *sch;
2203
2204         sch = to_subchannel(cdev->dev.parent);
2205         return sch->schid;
2206 }
2207
2208 MODULE_LICENSE("GPL");
2209 EXPORT_SYMBOL(ccw_device_set_online);
2210 EXPORT_SYMBOL(ccw_device_set_offline);
2211 EXPORT_SYMBOL(ccw_driver_register);
2212 EXPORT_SYMBOL(ccw_driver_unregister);
2213 EXPORT_SYMBOL(get_ccwdev_by_busid);
2214 EXPORT_SYMBOL(ccw_bus_type);
2215 EXPORT_SYMBOL(ccw_device_work);
2216 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);