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