drivers/s390/cio/device.c

   1 // SPDX-License-Identifier: GPL-1.0+
   2 /*
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002, 2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/export.h>
  15 #include <linux/init.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/errno.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include <linux/list.h>
  21 #include <linux/device.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/delay.h>
  24 #include <linux/timer.h>
  25 #include <linux/kernel_stat.h>
  26 #include <linux/sched/signal.h>
  27
  28 #include <asm/ccwdev.h>
  29 #include <asm/cio.h>
  30 #include <asm/param.h>          /* HZ */
  31 #include <asm/cmb.h>
  32 #include <asm/isc.h>
  33
  34 #include "chp.h"
  35 #include "cio.h"
  36 #include "cio_debug.h"
  37 #include "css.h"
  38 #include "device.h"
  39 #include "ioasm.h"
  40 #include "io_sch.h"
  41 #include "blacklist.h"
  42 #include "chsc.h"
  43
  44 static struct timer_list recovery_timer;
  45 static DEFINE_SPINLOCK(recovery_lock);
  46 static int recovery_phase;
  47 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  48
  49 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
  50 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
  51 static struct bus_type ccw_bus_type;
  52
  53 /******************* bus type handling ***********************/
  54
  55 /* The Linux driver model distinguishes between a bus type and
  56  * the bus itself. Of course we only have one channel
  57  * subsystem driver and one channel system per machine, but
  58  * we still use the abstraction. T.R. says it's a good idea. */
  59 static int
  60 ccw_bus_match (struct device * dev, struct device_driver * drv)
  61 {
  62         struct ccw_device *cdev = to_ccwdev(dev);
  63         struct ccw_driver *cdrv = to_ccwdrv(drv);
  64         const struct ccw_device_id *ids = cdrv->ids, *found;
  65
  66         if (!ids)
  67                 return 0;
  68
  69         found = ccw_device_id_match(ids, &cdev->id);
  70         if (!found)
  71                 return 0;
  72
  73         cdev->id.driver_info = found->driver_info;
  74
  75         return 1;
  76 }
  77
  78 /* Store modalias string delimited by prefix/suffix string into buffer with
  79  * specified size. Return length of resulting string (excluding trailing '\0')
  80  * even if string doesn't fit buffer (snprintf semantics). */
  81 static int snprint_alias(char *buf, size_t size,
  82                          struct ccw_device_id *id, const char *suffix)
  83 {
  84         int len;
  85
  86         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  87         if (len > size)
  88                 return len;
  89         buf += len;
  90         size -= len;
  91
  92         if (id->dev_type != 0)
  93                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  94                                 id->dev_model, suffix);
  95         else
  96                 len += snprintf(buf, size, "dtdm%s", suffix);
  97
  98         return len;
  99 }
 100
 101 /* Set up environment variables for ccw device uevent. Return 0 on success,
 102  * non-zero otherwise. */
 103 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
 104 {
 105         struct ccw_device *cdev = to_ccwdev(dev);
 106         struct ccw_device_id *id = &(cdev->id);
 107         int ret;
 108         char modalias_buf[30];
 109
 110         /* CU_TYPE= */
 111         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 112         if (ret)
 113                 return ret;
 114
 115         /* CU_MODEL= */
 116         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 117         if (ret)
 118                 return ret;
 119
 120         /* The next two can be zero, that's ok for us */
 121         /* DEV_TYPE= */
 122         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 123         if (ret)
 124                 return ret;
 125
 126         /* DEV_MODEL= */
 127         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 128         if (ret)
 129                 return ret;
 130
 131         /* MODALIAS=  */
 132         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 133         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 134         return ret;
 135 }
 136
 137 static void io_subchannel_irq(struct subchannel *);
 138 static int io_subchannel_probe(struct subchannel *);
 139 static int io_subchannel_remove(struct subchannel *);
 140 static void io_subchannel_shutdown(struct subchannel *);
 141 static int io_subchannel_sch_event(struct subchannel *, int);
 142 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 143                                    int);
 144 static void recovery_func(struct timer_list *unused);
 145
 146 static struct css_device_id io_subchannel_ids[] = {
 147         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 148         { /* end of list */ },
 149 };
 150
 151 static int io_subchannel_prepare(struct subchannel *sch)
 152 {
 153         struct ccw_device *cdev;
 154         /*
 155          * Don't allow suspend while a ccw device registration
 156          * is still outstanding.
 157          */
 158         cdev = sch_get_cdev(sch);
 159         if (cdev && !device_is_registered(&cdev->dev))
 160                 return -EAGAIN;
 161         return 0;
 162 }
 163
 164 static int io_subchannel_settle(void)
 165 {
 166         int ret;
 167
 168         ret = wait_event_interruptible(ccw_device_init_wq,
 169                                 atomic_read(&ccw_device_init_count) == 0);
 170         if (ret)
 171                 return -EINTR;
 172         flush_workqueue(cio_work_q);
 173         return 0;
 174 }
 175
 176 static struct css_driver io_subchannel_driver = {
 177         .drv = {
 178                 .owner = THIS_MODULE,
 179                 .name = "io_subchannel",
 180         },
 181         .subchannel_type = io_subchannel_ids,
 182         .irq = io_subchannel_irq,
 183         .sch_event = io_subchannel_sch_event,
 184         .chp_event = io_subchannel_chp_event,
 185         .probe = io_subchannel_probe,
 186         .remove = io_subchannel_remove,
 187         .shutdown = io_subchannel_shutdown,
 188         .prepare = io_subchannel_prepare,
 189         .settle = io_subchannel_settle,
 190 };
 191
 192 int __init io_subchannel_init(void)
 193 {
 194         int ret;
 195
 196         timer_setup(&recovery_timer, recovery_func, 0);
 197         ret = bus_register(&ccw_bus_type);
 198         if (ret)
 199                 return ret;
 200         ret = css_driver_register(&io_subchannel_driver);
 201         if (ret)
 202                 bus_unregister(&ccw_bus_type);
 203
 204         return ret;
 205 }
 206
 207
 208 /************************ device handling **************************/
 209
 210 static ssize_t
 211 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 212 {
 213         struct ccw_device *cdev = to_ccwdev(dev);
 214         struct ccw_device_id *id = &(cdev->id);
 215
 216         if (id->dev_type != 0)
 217                 return sprintf(buf, "%04x/%02x\n",
 218                                 id->dev_type, id->dev_model);
 219         else
 220                 return sprintf(buf, "n/a\n");
 221 }
 222
 223 static ssize_t
 224 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 225 {
 226         struct ccw_device *cdev = to_ccwdev(dev);
 227         struct ccw_device_id *id = &(cdev->id);
 228
 229         return sprintf(buf, "%04x/%02x\n",
 230                        id->cu_type, id->cu_model);
 231 }
 232
 233 static ssize_t
 234 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 235 {
 236         struct ccw_device *cdev = to_ccwdev(dev);
 237         struct ccw_device_id *id = &(cdev->id);
 238         int len;
 239
 240         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 241
 242         return len > PAGE_SIZE ? PAGE_SIZE : len;
 243 }
 244
 245 static ssize_t
 246 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 247 {
 248         struct ccw_device *cdev = to_ccwdev(dev);
 249
 250         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 251 }
 252
 253 int ccw_device_is_orphan(struct ccw_device *cdev)
 254 {
 255         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 256 }
 257
 258 static void ccw_device_unregister(struct ccw_device *cdev)
 259 {
 260         if (device_is_registered(&cdev->dev)) {
 261                 /* Undo device_add(). */
 262                 device_del(&cdev->dev);
 263         }
 264         if (cdev->private->flags.initialized) {
 265                 cdev->private->flags.initialized = 0;
 266                 /* Release reference from device_initialize(). */
 267                 put_device(&cdev->dev);
 268         }
 269 }
 270
 271 static void io_subchannel_quiesce(struct subchannel *);
 272
 273 /**
 274  * ccw_device_set_offline() - disable a ccw device for I/O
 275  * @cdev: target ccw device
 276  *
 277  * This function calls the driver's set_offline() function for @cdev, if
 278  * given, and then disables @cdev.
 279  * Returns:
 280  *   %0 on success and a negative error value on failure.
 281  * Context:
 282  *  enabled, ccw device lock not held
 283  */
 284 int ccw_device_set_offline(struct ccw_device *cdev)
 285 {
 286         struct subchannel *sch;
 287         int ret, state;
 288
 289         if (!cdev)
 290                 return -ENODEV;
 291         if (!cdev->online || !cdev->drv)
 292                 return -EINVAL;
 293
 294         if (cdev->drv->set_offline) {
 295                 ret = cdev->drv->set_offline(cdev);
 296                 if (ret != 0)
 297                         return ret;
 298         }
 299         spin_lock_irq(cdev->ccwlock);
 300         sch = to_subchannel(cdev->dev.parent);
 301         cdev->online = 0;
 302         /* Wait until a final state or DISCONNECTED is reached */
 303         while (!dev_fsm_final_state(cdev) &&
 304                cdev->private->state != DEV_STATE_DISCONNECTED) {
 305                 spin_unlock_irq(cdev->ccwlock);
 306                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 307                            cdev->private->state == DEV_STATE_DISCONNECTED));
 308                 spin_lock_irq(cdev->ccwlock);
 309         }
 310         do {
 311                 ret = ccw_device_offline(cdev);
 312                 if (!ret)
 313                         break;
 314                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 315                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 316                               cdev->private->dev_id.devno);
 317                 if (ret != -EBUSY)
 318                         goto error;
 319                 state = cdev->private->state;
 320                 spin_unlock_irq(cdev->ccwlock);
 321                 io_subchannel_quiesce(sch);
 322                 spin_lock_irq(cdev->ccwlock);
 323                 cdev->private->state = state;
 324         } while (ret == -EBUSY);
 325         spin_unlock_irq(cdev->ccwlock);
 326         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 327                    cdev->private->state == DEV_STATE_DISCONNECTED));
 328         /* Inform the user if set offline failed. */
 329         if (cdev->private->state == DEV_STATE_BOXED) {
 330                 pr_warn("%s: The device entered boxed state while being set offline\n",
 331                         dev_name(&cdev->dev));
 332         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 333                 pr_warn("%s: The device stopped operating while being set offline\n",
 334                         dev_name(&cdev->dev));
 335         }
 336         /* Give up reference from ccw_device_set_online(). */
 337         put_device(&cdev->dev);
 338         return 0;
 339
 340 error:
 341         cdev->private->state = DEV_STATE_OFFLINE;
 342         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 343         spin_unlock_irq(cdev->ccwlock);
 344         /* Give up reference from ccw_device_set_online(). */
 345         put_device(&cdev->dev);
 346         return -ENODEV;
 347 }
 348
 349 /**
 350  * ccw_device_set_online() - enable a ccw device for I/O
 351  * @cdev: target ccw device
 352  *
 353  * This function first enables @cdev and then calls the driver's set_online()
 354  * function for @cdev, if given. If set_online() returns an error, @cdev is
 355  * disabled again.
 356  * Returns:
 357  *   %0 on success and a negative error value on failure.
 358  * Context:
 359  *  enabled, ccw device lock not held
 360  */
 361 int ccw_device_set_online(struct ccw_device *cdev)
 362 {
 363         int ret;
 364         int ret2;
 365
 366         if (!cdev)
 367                 return -ENODEV;
 368         if (cdev->online || !cdev->drv)
 369                 return -EINVAL;
 370         /* Hold on to an extra reference while device is online. */
 371         if (!get_device(&cdev->dev))
 372                 return -ENODEV;
 373
 374         spin_lock_irq(cdev->ccwlock);
 375         ret = ccw_device_online(cdev);
 376         spin_unlock_irq(cdev->ccwlock);
 377         if (ret == 0)
 378                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 379         else {
 380                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 381                               "device 0.%x.%04x\n",
 382                               ret, cdev->private->dev_id.ssid,
 383                               cdev->private->dev_id.devno);
 384                 /* Give up online reference since onlining failed. */
 385                 put_device(&cdev->dev);
 386                 return ret;
 387         }
 388         spin_lock_irq(cdev->ccwlock);
 389         /* Check if online processing was successful */
 390         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 391             (cdev->private->state != DEV_STATE_W4SENSE)) {
 392                 spin_unlock_irq(cdev->ccwlock);
 393                 /* Inform the user that set online failed. */
 394                 if (cdev->private->state == DEV_STATE_BOXED) {
 395                         pr_warn("%s: Setting the device online failed because it is boxed\n",
 396                                 dev_name(&cdev->dev));
 397                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 398                         pr_warn("%s: Setting the device online failed because it is not operational\n",
 399                                 dev_name(&cdev->dev));
 400                 }
 401                 /* Give up online reference since onlining failed. */
 402                 put_device(&cdev->dev);
 403                 return -ENODEV;
 404         }
 405         spin_unlock_irq(cdev->ccwlock);
 406         if (cdev->drv->set_online)
 407                 ret = cdev->drv->set_online(cdev);
 408         if (ret)
 409                 goto rollback;
 410
 411         spin_lock_irq(cdev->ccwlock);
 412         cdev->online = 1;
 413         spin_unlock_irq(cdev->ccwlock);
 414         return 0;
 415
 416 rollback:
 417         spin_lock_irq(cdev->ccwlock);
 418         /* Wait until a final state or DISCONNECTED is reached */
 419         while (!dev_fsm_final_state(cdev) &&
 420                cdev->private->state != DEV_STATE_DISCONNECTED) {
 421                 spin_unlock_irq(cdev->ccwlock);
 422                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 423                            cdev->private->state == DEV_STATE_DISCONNECTED));
 424                 spin_lock_irq(cdev->ccwlock);
 425         }
 426         ret2 = ccw_device_offline(cdev);
 427         if (ret2)
 428                 goto error;
 429         spin_unlock_irq(cdev->ccwlock);
 430         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 431                    cdev->private->state == DEV_STATE_DISCONNECTED));
 432         /* Give up online reference since onlining failed. */
 433         put_device(&cdev->dev);
 434         return ret;
 435
 436 error:
 437         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 438                       "device 0.%x.%04x\n",
 439                       ret2, cdev->private->dev_id.ssid,
 440                       cdev->private->dev_id.devno);
 441         cdev->private->state = DEV_STATE_OFFLINE;
 442         spin_unlock_irq(cdev->ccwlock);
 443         /* Give up online reference since onlining failed. */
 444         put_device(&cdev->dev);
 445         return ret;
 446 }
 447
 448 static int online_store_handle_offline(struct ccw_device *cdev)
 449 {
 450         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 451                 spin_lock_irq(cdev->ccwlock);
 452                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 453                 spin_unlock_irq(cdev->ccwlock);
 454                 return 0;
 455         }
 456         if (cdev->drv && cdev->drv->set_offline)
 457                 return ccw_device_set_offline(cdev);
 458         return -EINVAL;
 459 }
 460
 461 static int online_store_recog_and_online(struct ccw_device *cdev)
 462 {
 463         /* Do device recognition, if needed. */
 464         if (cdev->private->state == DEV_STATE_BOXED) {
 465                 spin_lock_irq(cdev->ccwlock);
 466                 ccw_device_recognition(cdev);
 467                 spin_unlock_irq(cdev->ccwlock);
 468                 wait_event(cdev->private->wait_q,
 469                            cdev->private->flags.recog_done);
 470                 if (cdev->private->state != DEV_STATE_OFFLINE)
 471                         /* recognition failed */
 472                         return -EAGAIN;
 473         }
 474         if (cdev->drv && cdev->drv->set_online)
 475                 return ccw_device_set_online(cdev);
 476         return -EINVAL;
 477 }
 478
 479 static int online_store_handle_online(struct ccw_device *cdev, int force)
 480 {
 481         int ret;
 482
 483         ret = online_store_recog_and_online(cdev);
 484         if (ret && !force)
 485                 return ret;
 486         if (force && cdev->private->state == DEV_STATE_BOXED) {
 487                 ret = ccw_device_stlck(cdev);
 488                 if (ret)
 489                         return ret;
 490                 if (cdev->id.cu_type == 0)
 491                         cdev->private->state = DEV_STATE_NOT_OPER;
 492                 ret = online_store_recog_and_online(cdev);
 493                 if (ret)
 494                         return ret;
 495         }
 496         return 0;
 497 }
 498
 499 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 500                              const char *buf, size_t count)
 501 {
 502         struct ccw_device *cdev = to_ccwdev(dev);
 503         int force, ret;
 504         unsigned long i;
 505
 506         /* Prevent conflict between multiple on-/offline processing requests. */
 507         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 508                 return -EAGAIN;
 509         /* Prevent conflict between internal I/Os and on-/offline processing. */
 510         if (!dev_fsm_final_state(cdev) &&
 511             cdev->private->state != DEV_STATE_DISCONNECTED) {
 512                 ret = -EAGAIN;
 513                 goto out;
 514         }
 515         /* Prevent conflict between pending work and on-/offline processing.*/
 516         if (work_pending(&cdev->private->todo_work)) {
 517                 ret = -EAGAIN;
 518                 goto out;
 519         }
 520         if (!strncmp(buf, "force\n", count)) {
 521                 force = 1;
 522                 i = 1;
 523                 ret = 0;
 524         } else {
 525                 force = 0;
 526                 ret = kstrtoul(buf, 16, &i);
 527         }
 528         if (ret)
 529                 goto out;
 530
 531         device_lock(dev);
 532         switch (i) {
 533         case 0:
 534                 ret = online_store_handle_offline(cdev);
 535                 break;
 536         case 1:
 537                 ret = online_store_handle_online(cdev, force);
 538                 break;
 539         default:
 540                 ret = -EINVAL;
 541         }
 542         device_unlock(dev);
 543
 544 out:
 545         atomic_set(&cdev->private->onoff, 0);
 546         return (ret < 0) ? ret : count;
 547 }
 548
 549 static ssize_t
 550 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 551 {
 552         struct ccw_device *cdev = to_ccwdev(dev);
 553         struct subchannel *sch;
 554
 555         if (ccw_device_is_orphan(cdev))
 556                 return sprintf(buf, "no device\n");
 557         switch (cdev->private->state) {
 558         case DEV_STATE_BOXED:
 559                 return sprintf(buf, "boxed\n");
 560         case DEV_STATE_DISCONNECTED:
 561         case DEV_STATE_DISCONNECTED_SENSE_ID:
 562         case DEV_STATE_NOT_OPER:
 563                 sch = to_subchannel(dev->parent);
 564                 if (!sch->lpm)
 565                         return sprintf(buf, "no path\n");
 566                 else
 567                         return sprintf(buf, "no device\n");
 568         default:
 569                 /* All other states considered fine. */
 570                 return sprintf(buf, "good\n");
 571         }
 572 }
 573
 574 static ssize_t
 575 initiate_logging(struct device *dev, struct device_attribute *attr,
 576                  const char *buf, size_t count)
 577 {
 578         struct subchannel *sch = to_subchannel(dev);
 579         int rc;
 580
 581         rc = chsc_siosl(sch->schid);
 582         if (rc < 0) {
 583                 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
 584                         sch->schid.ssid, sch->schid.sch_no, rc);
 585                 return rc;
 586         }
 587         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 588                   sch->schid.ssid, sch->schid.sch_no);
 589         return count;
 590 }
 591
 592 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 593                         char *buf)
 594 {
 595         struct subchannel *sch = to_subchannel(dev);
 596
 597         return sprintf(buf, "%02x\n", sch->vpm);
 598 }
 599
 600 static DEVICE_ATTR_RO(devtype);
 601 static DEVICE_ATTR_RO(cutype);
 602 static DEVICE_ATTR_RO(modalias);
 603 static DEVICE_ATTR_RW(online);
 604 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 605 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 606 static DEVICE_ATTR_RO(vpm);
 607
 608 static struct attribute *io_subchannel_attrs[] = {
 609         &dev_attr_logging.attr,
 610         &dev_attr_vpm.attr,
 611         NULL,
 612 };
 613
 614 static const struct attribute_group io_subchannel_attr_group = {
 615         .attrs = io_subchannel_attrs,
 616 };
 617
 618 static struct attribute * ccwdev_attrs[] = {
 619         &dev_attr_devtype.attr,
 620         &dev_attr_cutype.attr,
 621         &dev_attr_modalias.attr,
 622         &dev_attr_online.attr,
 623         &dev_attr_cmb_enable.attr,
 624         &dev_attr_availability.attr,
 625         NULL,
 626 };
 627
 628 static const struct attribute_group ccwdev_attr_group = {
 629         .attrs = ccwdev_attrs,
 630 };
 631
 632 static const struct attribute_group *ccwdev_attr_groups[] = {
 633         &ccwdev_attr_group,
 634         NULL,
 635 };
 636
 637 static int ccw_device_add(struct ccw_device *cdev)
 638 {
 639         struct device *dev = &cdev->dev;
 640
 641         dev->bus = &ccw_bus_type;
 642         return device_add(dev);
 643 }
 644
 645 static int match_dev_id(struct device *dev, void *data)
 646 {
 647         struct ccw_device *cdev = to_ccwdev(dev);
 648         struct ccw_dev_id *dev_id = data;
 649
 650         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 651 }
 652
 653 /**
 654  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 655  * @dev_id: id of the device to be searched
 656  *
 657  * This function searches all devices attached to the ccw bus for a device
 658  * matching @dev_id.
 659  * Returns:
 660  *  If a device is found its reference count is increased and returned;
 661  *  else %NULL is returned.
 662  */
 663 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 664 {
 665         struct device *dev;
 666
 667         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 668
 669         return dev ? to_ccwdev(dev) : NULL;
 670 }
 671 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 672
 673 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 674 {
 675         int ret;
 676
 677         if (device_is_registered(&cdev->dev)) {
 678                 device_release_driver(&cdev->dev);
 679                 ret = device_attach(&cdev->dev);
 680                 WARN_ON(ret == -ENODEV);
 681         }
 682 }
 683
 684 static void
 685 ccw_device_release(struct device *dev)
 686 {
 687         struct ccw_device *cdev;
 688
 689         cdev = to_ccwdev(dev);
 690         /* Release reference of parent subchannel. */
 691         put_device(cdev->dev.parent);
 692         kfree(cdev->private);
 693         kfree(cdev);
 694 }
 695
 696 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 697 {
 698         struct ccw_device *cdev;
 699
 700         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 701         if (cdev) {
 702                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 703                                         GFP_KERNEL | GFP_DMA);
 704                 if (cdev->private)
 705                         return cdev;
 706         }
 707         kfree(cdev);
 708         return ERR_PTR(-ENOMEM);
 709 }
 710
 711 static void ccw_device_todo(struct work_struct *work);
 712
 713 static int io_subchannel_initialize_dev(struct subchannel *sch,
 714                                         struct ccw_device *cdev)
 715 {
 716         struct ccw_device_private *priv = cdev->private;
 717         int ret;
 718
 719         priv->cdev = cdev;
 720         priv->int_class = IRQIO_CIO;
 721         priv->state = DEV_STATE_NOT_OPER;
 722         priv->dev_id.devno = sch->schib.pmcw.dev;
 723         priv->dev_id.ssid = sch->schid.ssid;
 724
 725         INIT_WORK(&priv->todo_work, ccw_device_todo);
 726         INIT_LIST_HEAD(&priv->cmb_list);
 727         init_waitqueue_head(&priv->wait_q);
 728         timer_setup(&priv->timer, ccw_device_timeout, 0);
 729
 730         atomic_set(&priv->onoff, 0);
 731         cdev->ccwlock = sch->lock;
 732         cdev->dev.parent = &sch->dev;
 733         cdev->dev.release = ccw_device_release;
 734         cdev->dev.groups = ccwdev_attr_groups;
 735         /* Do first half of device_register. */
 736         device_initialize(&cdev->dev);
 737         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 738                            cdev->private->dev_id.devno);
 739         if (ret)
 740                 goto out_put;
 741         if (!get_device(&sch->dev)) {
 742                 ret = -ENODEV;
 743                 goto out_put;
 744         }
 745         priv->flags.initialized = 1;
 746         spin_lock_irq(sch->lock);
 747         sch_set_cdev(sch, cdev);
 748         spin_unlock_irq(sch->lock);
 749         return 0;
 750
 751 out_put:
 752         /* Release reference from device_initialize(). */
 753         put_device(&cdev->dev);
 754         return ret;
 755 }
 756
 757 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 758 {
 759         struct ccw_device *cdev;
 760         int ret;
 761
 762         cdev = io_subchannel_allocate_dev(sch);
 763         if (!IS_ERR(cdev)) {
 764                 ret = io_subchannel_initialize_dev(sch, cdev);
 765                 if (ret)
 766                         cdev = ERR_PTR(ret);
 767         }
 768         return cdev;
 769 }
 770
 771 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 772
 773 static void sch_create_and_recog_new_device(struct subchannel *sch)
 774 {
 775         struct ccw_device *cdev;
 776
 777         /* Need to allocate a new ccw device. */
 778         cdev = io_subchannel_create_ccwdev(sch);
 779         if (IS_ERR(cdev)) {
 780                 /* OK, we did everything we could... */
 781                 css_sch_device_unregister(sch);
 782                 return;
 783         }
 784         /* Start recognition for the new ccw device. */
 785         io_subchannel_recog(cdev, sch);
 786 }
 787
 788 /*
 789  * Register recognized device.
 790  */
 791 static void io_subchannel_register(struct ccw_device *cdev)
 792 {
 793         struct subchannel *sch;
 794         int ret, adjust_init_count = 1;
 795         unsigned long flags;
 796
 797         sch = to_subchannel(cdev->dev.parent);
 798         /*
 799          * Check if subchannel is still registered. It may have become
 800          * unregistered if a machine check hit us after finishing
 801          * device recognition but before the register work could be
 802          * queued.
 803          */
 804         if (!device_is_registered(&sch->dev))
 805                 goto out_err;
 806         css_update_ssd_info(sch);
 807         /*
 808          * io_subchannel_register() will also be called after device
 809          * recognition has been done for a boxed device (which will already
 810          * be registered). We need to reprobe since we may now have sense id
 811          * information.
 812          */
 813         if (device_is_registered(&cdev->dev)) {
 814                 if (!cdev->drv) {
 815                         ret = device_reprobe(&cdev->dev);
 816                         if (ret)
 817                                 /* We can't do much here. */
 818                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 819                                               " %d for 0.%x.%04x\n", ret,
 820                                               cdev->private->dev_id.ssid,
 821                                               cdev->private->dev_id.devno);
 822                 }
 823                 adjust_init_count = 0;
 824                 goto out;
 825         }
 826         /*
 827          * Now we know this subchannel will stay, we can throw
 828          * our delayed uevent.
 829          */
 830         dev_set_uevent_suppress(&sch->dev, 0);
 831         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 832         /* make it known to the system */
 833         ret = ccw_device_add(cdev);
 834         if (ret) {
 835                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 836                               cdev->private->dev_id.ssid,
 837                               cdev->private->dev_id.devno, ret);
 838                 spin_lock_irqsave(sch->lock, flags);
 839                 sch_set_cdev(sch, NULL);
 840                 spin_unlock_irqrestore(sch->lock, flags);
 841                 /* Release initial device reference. */
 842                 put_device(&cdev->dev);
 843                 goto out_err;
 844         }
 845 out:
 846         cdev->private->flags.recog_done = 1;
 847         wake_up(&cdev->private->wait_q);
 848 out_err:
 849         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 850                 wake_up(&ccw_device_init_wq);
 851 }
 852
 853 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 854 {
 855         struct subchannel *sch;
 856
 857         /* Get subchannel reference for local processing. */
 858         if (!get_device(cdev->dev.parent))
 859                 return;
 860         sch = to_subchannel(cdev->dev.parent);
 861         css_sch_device_unregister(sch);
 862         /* Release subchannel reference for local processing. */
 863         put_device(&sch->dev);
 864 }
 865
 866 /*
 867  * subchannel recognition done. Called from the state machine.
 868  */
 869 void
 870 io_subchannel_recog_done(struct ccw_device *cdev)
 871 {
 872         if (css_init_done == 0) {
 873                 cdev->private->flags.recog_done = 1;
 874                 return;
 875         }
 876         switch (cdev->private->state) {
 877         case DEV_STATE_BOXED:
 878                 /* Device did not respond in time. */
 879         case DEV_STATE_NOT_OPER:
 880                 cdev->private->flags.recog_done = 1;
 881                 /* Remove device found not operational. */
 882                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 883                 if (atomic_dec_and_test(&ccw_device_init_count))
 884                         wake_up(&ccw_device_init_wq);
 885                 break;
 886         case DEV_STATE_OFFLINE:
 887                 /*
 888                  * We can't register the device in interrupt context so
 889                  * we schedule a work item.
 890                  */
 891                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 892                 break;
 893         }
 894 }
 895
 896 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 897 {
 898         /* Increase counter of devices currently in recognition. */
 899         atomic_inc(&ccw_device_init_count);
 900
 901         /* Start async. device sensing. */
 902         spin_lock_irq(sch->lock);
 903         ccw_device_recognition(cdev);
 904         spin_unlock_irq(sch->lock);
 905 }
 906
 907 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 908                                   struct subchannel *sch)
 909 {
 910         struct subchannel *old_sch;
 911         int rc, old_enabled = 0;
 912
 913         old_sch = to_subchannel(cdev->dev.parent);
 914         /* Obtain child reference for new parent. */
 915         if (!get_device(&sch->dev))
 916                 return -ENODEV;
 917
 918         if (!sch_is_pseudo_sch(old_sch)) {
 919                 spin_lock_irq(old_sch->lock);
 920                 old_enabled = old_sch->schib.pmcw.ena;
 921                 rc = 0;
 922                 if (old_enabled)
 923                         rc = cio_disable_subchannel(old_sch);
 924                 spin_unlock_irq(old_sch->lock);
 925                 if (rc == -EBUSY) {
 926                         /* Release child reference for new parent. */
 927                         put_device(&sch->dev);
 928                         return rc;
 929                 }
 930         }
 931
 932         mutex_lock(&sch->reg_mutex);
 933         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 934         mutex_unlock(&sch->reg_mutex);
 935         if (rc) {
 936                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 937                               cdev->private->dev_id.ssid,
 938                               cdev->private->dev_id.devno, sch->schid.ssid,
 939                               sch->schib.pmcw.dev, rc);
 940                 if (old_enabled) {
 941                         /* Try to reenable the old subchannel. */
 942                         spin_lock_irq(old_sch->lock);
 943                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 944                         spin_unlock_irq(old_sch->lock);
 945                 }
 946                 /* Release child reference for new parent. */
 947                 put_device(&sch->dev);
 948                 return rc;
 949         }
 950         /* Clean up old subchannel. */
 951         if (!sch_is_pseudo_sch(old_sch)) {
 952                 spin_lock_irq(old_sch->lock);
 953                 sch_set_cdev(old_sch, NULL);
 954                 spin_unlock_irq(old_sch->lock);
 955                 css_schedule_eval(old_sch->schid);
 956         }
 957         /* Release child reference for old parent. */
 958         put_device(&old_sch->dev);
 959         /* Initialize new subchannel. */
 960         spin_lock_irq(sch->lock);
 961         cdev->ccwlock = sch->lock;
 962         if (!sch_is_pseudo_sch(sch))
 963                 sch_set_cdev(sch, cdev);
 964         spin_unlock_irq(sch->lock);
 965         if (!sch_is_pseudo_sch(sch))
 966                 css_update_ssd_info(sch);
 967         return 0;
 968 }
 969
 970 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 971 {
 972         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 973         struct channel_subsystem *css = to_css(sch->dev.parent);
 974
 975         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 976 }
 977
 978 static void io_subchannel_irq(struct subchannel *sch)
 979 {
 980         struct ccw_device *cdev;
 981
 982         cdev = sch_get_cdev(sch);
 983
 984         CIO_TRACE_EVENT(6, "IRQ");
 985         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
 986         if (cdev)
 987                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
 988         else
 989                 inc_irq_stat(IRQIO_CIO);
 990 }
 991
 992 void io_subchannel_init_config(struct subchannel *sch)
 993 {
 994         memset(&sch->config, 0, sizeof(sch->config));
 995         sch->config.csense = 1;
 996 }
 997
 998 static void io_subchannel_init_fields(struct subchannel *sch)
 999 {
1000         if (cio_is_console(sch->schid))
1001                 sch->opm = 0xff;
1002         else
1003                 sch->opm = chp_get_sch_opm(sch);
1004         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1005         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1006
1007         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1008                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1009                       sch->schib.pmcw.dev, sch->schid.ssid,
1010                       sch->schid.sch_no, sch->schib.pmcw.pim,
1011                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1012
1013         io_subchannel_init_config(sch);
1014 }
1015
1016 /*
1017  * Note: We always return 0 so that we bind to the device even on error.
1018  * This is needed so that our remove function is called on unregister.
1019  */
1020 static int io_subchannel_probe(struct subchannel *sch)
1021 {
1022         struct io_subchannel_private *io_priv;
1023         struct ccw_device *cdev;
1024         int rc;
1025
1026         if (cio_is_console(sch->schid)) {
1027                 rc = sysfs_create_group(&sch->dev.kobj,
1028                                         &io_subchannel_attr_group);
1029                 if (rc)
1030                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1031                                       "attributes for subchannel "
1032                                       "0.%x.%04x (rc=%d)\n",
1033                                       sch->schid.ssid, sch->schid.sch_no, rc);
1034                 /*
1035                  * The console subchannel already has an associated ccw_device.
1036                  * Throw the delayed uevent for the subchannel, register
1037                  * the ccw_device and exit.
1038                  */
1039                 dev_set_uevent_suppress(&sch->dev, 0);
1040                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1041                 cdev = sch_get_cdev(sch);
1042                 rc = ccw_device_add(cdev);
1043                 if (rc) {
1044                         /* Release online reference. */
1045                         put_device(&cdev->dev);
1046                         goto out_schedule;
1047                 }
1048                 if (atomic_dec_and_test(&ccw_device_init_count))
1049                         wake_up(&ccw_device_init_wq);
1050                 return 0;
1051         }
1052         io_subchannel_init_fields(sch);
1053         rc = cio_commit_config(sch);
1054         if (rc)
1055                 goto out_schedule;
1056         rc = sysfs_create_group(&sch->dev.kobj,
1057                                 &io_subchannel_attr_group);
1058         if (rc)
1059                 goto out_schedule;
1060         /* Allocate I/O subchannel private data. */
1061         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1062         if (!io_priv)
1063                 goto out_schedule;
1064
1065         set_io_private(sch, io_priv);
1066         css_schedule_eval(sch->schid);
1067         return 0;
1068
1069 out_schedule:
1070         spin_lock_irq(sch->lock);
1071         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1072         spin_unlock_irq(sch->lock);
1073         return 0;
1074 }
1075
1076 static int io_subchannel_remove(struct subchannel *sch)
1077 {
1078         struct io_subchannel_private *io_priv = to_io_private(sch);
1079         struct ccw_device *cdev;
1080
1081         cdev = sch_get_cdev(sch);
1082         if (!cdev)
1083                 goto out_free;
1084
1085         ccw_device_unregister(cdev);
1086         spin_lock_irq(sch->lock);
1087         sch_set_cdev(sch, NULL);
1088         set_io_private(sch, NULL);
1089         spin_unlock_irq(sch->lock);
1090 out_free:
1091         kfree(io_priv);
1092         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1093         return 0;
1094 }
1095
1096 static void io_subchannel_verify(struct subchannel *sch)
1097 {
1098         struct ccw_device *cdev;
1099
1100         cdev = sch_get_cdev(sch);
1101         if (cdev)
1102                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1103 }
1104
1105 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1106 {
1107         struct ccw_device *cdev;
1108
1109         cdev = sch_get_cdev(sch);
1110         if (!cdev)
1111                 return;
1112         if (cio_update_schib(sch))
1113                 goto err;
1114         /* Check for I/O on path. */
1115         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1116                 goto out;
1117         if (cdev->private->state == DEV_STATE_ONLINE) {
1118                 ccw_device_kill_io(cdev);
1119                 goto out;
1120         }
1121         if (cio_clear(sch))
1122                 goto err;
1123 out:
1124         /* Trigger path verification. */
1125         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1126         return;
1127
1128 err:
1129         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1130 }
1131
1132 static int io_subchannel_chp_event(struct subchannel *sch,
1133                                    struct chp_link *link, int event)
1134 {
1135         struct ccw_device *cdev = sch_get_cdev(sch);
1136         int mask;
1137
1138         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1139         if (!mask)
1140                 return 0;
1141         switch (event) {
1142         case CHP_VARY_OFF:
1143                 sch->opm &= ~mask;
1144                 sch->lpm &= ~mask;
1145                 if (cdev)
1146                         cdev->private->path_gone_mask |= mask;
1147                 io_subchannel_terminate_path(sch, mask);
1148                 break;
1149         case CHP_VARY_ON:
1150                 sch->opm |= mask;
1151                 sch->lpm |= mask;
1152                 if (cdev)
1153                         cdev->private->path_new_mask |= mask;
1154                 io_subchannel_verify(sch);
1155                 break;
1156         case CHP_OFFLINE:
1157                 if (cio_update_schib(sch))
1158                         return -ENODEV;
1159                 if (cdev)
1160                         cdev->private->path_gone_mask |= mask;
1161                 io_subchannel_terminate_path(sch, mask);
1162                 break;
1163         case CHP_ONLINE:
1164                 if (cio_update_schib(sch))
1165                         return -ENODEV;
1166                 sch->lpm |= mask & sch->opm;
1167                 if (cdev)
1168                         cdev->private->path_new_mask |= mask;
1169                 io_subchannel_verify(sch);
1170                 break;
1171         }
1172         return 0;
1173 }
1174
1175 static void io_subchannel_quiesce(struct subchannel *sch)
1176 {
1177         struct ccw_device *cdev;
1178         int ret;
1179
1180         spin_lock_irq(sch->lock);
1181         cdev = sch_get_cdev(sch);
1182         if (cio_is_console(sch->schid))
1183                 goto out_unlock;
1184         if (!sch->schib.pmcw.ena)
1185                 goto out_unlock;
1186         ret = cio_disable_subchannel(sch);
1187         if (ret != -EBUSY)
1188                 goto out_unlock;
1189         if (cdev->handler)
1190                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1191         while (ret == -EBUSY) {
1192                 cdev->private->state = DEV_STATE_QUIESCE;
1193                 cdev->private->iretry = 255;
1194                 ret = ccw_device_cancel_halt_clear(cdev);
1195                 if (ret == -EBUSY) {
1196                         ccw_device_set_timeout(cdev, HZ/10);
1197                         spin_unlock_irq(sch->lock);
1198                         wait_event(cdev->private->wait_q,
1199                                    cdev->private->state != DEV_STATE_QUIESCE);
1200                         spin_lock_irq(sch->lock);
1201                 }
1202                 ret = cio_disable_subchannel(sch);
1203         }
1204 out_unlock:
1205         spin_unlock_irq(sch->lock);
1206 }
1207
1208 static void io_subchannel_shutdown(struct subchannel *sch)
1209 {
1210         io_subchannel_quiesce(sch);
1211 }
1212
1213 static int device_is_disconnected(struct ccw_device *cdev)
1214 {
1215         if (!cdev)
1216                 return 0;
1217         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1218                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1219 }
1220
1221 static int recovery_check(struct device *dev, void *data)
1222 {
1223         struct ccw_device *cdev = to_ccwdev(dev);
1224         struct subchannel *sch;
1225         int *redo = data;
1226
1227         spin_lock_irq(cdev->ccwlock);
1228         switch (cdev->private->state) {
1229         case DEV_STATE_ONLINE:
1230                 sch = to_subchannel(cdev->dev.parent);
1231                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1232                         break;
1233                 /* fall through */
1234         case DEV_STATE_DISCONNECTED:
1235                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1236                               cdev->private->dev_id.ssid,
1237                               cdev->private->dev_id.devno);
1238                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1239                 *redo = 1;
1240                 break;
1241         case DEV_STATE_DISCONNECTED_SENSE_ID:
1242                 *redo = 1;
1243                 break;
1244         }
1245         spin_unlock_irq(cdev->ccwlock);
1246
1247         return 0;
1248 }
1249
1250 static void recovery_work_func(struct work_struct *unused)
1251 {
1252         int redo = 0;
1253
1254         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1255         if (redo) {
1256                 spin_lock_irq(&recovery_lock);
1257                 if (!timer_pending(&recovery_timer)) {
1258                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1259                                 recovery_phase++;
1260                         mod_timer(&recovery_timer, jiffies +
1261                                   recovery_delay[recovery_phase] * HZ);
1262                 }
1263                 spin_unlock_irq(&recovery_lock);
1264         } else
1265                 CIO_MSG_EVENT(3, "recovery: end\n");
1266 }
1267
1268 static DECLARE_WORK(recovery_work, recovery_work_func);
1269
1270 static void recovery_func(struct timer_list *unused)
1271 {
1272         /*
1273          * We can't do our recovery in softirq context and it's not
1274          * performance critical, so we schedule it.
1275          */
1276         schedule_work(&recovery_work);
1277 }
1278
1279 void ccw_device_schedule_recovery(void)
1280 {
1281         unsigned long flags;
1282
1283         CIO_MSG_EVENT(3, "recovery: schedule\n");
1284         spin_lock_irqsave(&recovery_lock, flags);
1285         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1286                 recovery_phase = 0;
1287                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1288         }
1289         spin_unlock_irqrestore(&recovery_lock, flags);
1290 }
1291
1292 static int purge_fn(struct device *dev, void *data)
1293 {
1294         struct ccw_device *cdev = to_ccwdev(dev);
1295         struct ccw_dev_id *id = &cdev->private->dev_id;
1296
1297         spin_lock_irq(cdev->ccwlock);
1298         if (is_blacklisted(id->ssid, id->devno) &&
1299             (cdev->private->state == DEV_STATE_OFFLINE) &&
1300             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1301                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1302                               id->devno);
1303                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1304                 atomic_set(&cdev->private->onoff, 0);
1305         }
1306         spin_unlock_irq(cdev->ccwlock);
1307         /* Abort loop in case of pending signal. */
1308         if (signal_pending(current))
1309                 return -EINTR;
1310
1311         return 0;
1312 }
1313
1314 /**
1315  * ccw_purge_blacklisted - purge unused, blacklisted devices
1316  *
1317  * Unregister all ccw devices that are offline and on the blacklist.
1318  */
1319 int ccw_purge_blacklisted(void)
1320 {
1321         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1322         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1323         return 0;
1324 }
1325
1326 void ccw_device_set_disconnected(struct ccw_device *cdev)
1327 {
1328         if (!cdev)
1329                 return;
1330         ccw_device_set_timeout(cdev, 0);
1331         cdev->private->flags.fake_irb = 0;
1332         cdev->private->state = DEV_STATE_DISCONNECTED;
1333         if (cdev->online)
1334                 ccw_device_schedule_recovery();
1335 }
1336
1337 void ccw_device_set_notoper(struct ccw_device *cdev)
1338 {
1339         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1340
1341         CIO_TRACE_EVENT(2, "notoper");
1342         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1343         ccw_device_set_timeout(cdev, 0);
1344         cio_disable_subchannel(sch);
1345         cdev->private->state = DEV_STATE_NOT_OPER;
1346 }
1347
1348 enum io_sch_action {
1349         IO_SCH_UNREG,
1350         IO_SCH_ORPH_UNREG,
1351         IO_SCH_ATTACH,
1352         IO_SCH_UNREG_ATTACH,
1353         IO_SCH_ORPH_ATTACH,
1354         IO_SCH_REPROBE,
1355         IO_SCH_VERIFY,
1356         IO_SCH_DISC,
1357         IO_SCH_NOP,
1358 };
1359
1360 static enum io_sch_action sch_get_action(struct subchannel *sch)
1361 {
1362         struct ccw_device *cdev;
1363
1364         cdev = sch_get_cdev(sch);
1365         if (cio_update_schib(sch)) {
1366                 /* Not operational. */
1367                 if (!cdev)
1368                         return IO_SCH_UNREG;
1369                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1370                         return IO_SCH_UNREG;
1371                 return IO_SCH_ORPH_UNREG;
1372         }
1373         /* Operational. */
1374         if (!cdev)
1375                 return IO_SCH_ATTACH;
1376         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1377                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1378                         return IO_SCH_UNREG_ATTACH;
1379                 return IO_SCH_ORPH_ATTACH;
1380         }
1381         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1382                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1383                         return IO_SCH_UNREG;
1384                 return IO_SCH_DISC;
1385         }
1386         if (device_is_disconnected(cdev))
1387                 return IO_SCH_REPROBE;
1388         if (cdev->online && !cdev->private->flags.resuming)
1389                 return IO_SCH_VERIFY;
1390         if (cdev->private->state == DEV_STATE_NOT_OPER)
1391                 return IO_SCH_UNREG_ATTACH;
1392         return IO_SCH_NOP;
1393 }
1394
1395 /**
1396  * io_subchannel_sch_event - process subchannel event
1397  * @sch: subchannel
1398  * @process: non-zero if function is called in process context
1399  *
1400  * An unspecified event occurred for this subchannel. Adjust data according
1401  * to the current operational state of the subchannel and device. Return
1402  * zero when the event has been handled sufficiently or -EAGAIN when this
1403  * function should be called again in process context.
1404  */
1405 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1406 {
1407         unsigned long flags;
1408         struct ccw_device *cdev;
1409         struct ccw_dev_id dev_id;
1410         enum io_sch_action action;
1411         int rc = -EAGAIN;
1412
1413         spin_lock_irqsave(sch->lock, flags);
1414         if (!device_is_registered(&sch->dev))
1415                 goto out_unlock;
1416         if (work_pending(&sch->todo_work))
1417                 goto out_unlock;
1418         cdev = sch_get_cdev(sch);
1419         if (cdev && work_pending(&cdev->private->todo_work))
1420                 goto out_unlock;
1421         action = sch_get_action(sch);
1422         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1423                       sch->schid.ssid, sch->schid.sch_no, process,
1424                       action);
1425         /* Perform immediate actions while holding the lock. */
1426         switch (action) {
1427         case IO_SCH_REPROBE:
1428                 /* Trigger device recognition. */
1429                 ccw_device_trigger_reprobe(cdev);
1430                 rc = 0;
1431                 goto out_unlock;
1432         case IO_SCH_VERIFY:
1433                 /* Trigger path verification. */
1434                 io_subchannel_verify(sch);
1435                 rc = 0;
1436                 goto out_unlock;
1437         case IO_SCH_DISC:
1438                 ccw_device_set_disconnected(cdev);
1439                 rc = 0;
1440                 goto out_unlock;
1441         case IO_SCH_ORPH_UNREG:
1442         case IO_SCH_ORPH_ATTACH:
1443                 ccw_device_set_disconnected(cdev);
1444                 break;
1445         case IO_SCH_UNREG_ATTACH:
1446         case IO_SCH_UNREG:
1447                 if (!cdev)
1448                         break;
1449                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1450                         /*
1451                          * Note: delayed work triggered by this event
1452                          * and repeated calls to sch_event are synchronized
1453                          * by the above check for work_pending(cdev).
1454                          */
1455                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1456                 } else
1457                         ccw_device_set_notoper(cdev);
1458                 break;
1459         case IO_SCH_NOP:
1460                 rc = 0;
1461                 goto out_unlock;
1462         default:
1463                 break;
1464         }
1465         spin_unlock_irqrestore(sch->lock, flags);
1466         /* All other actions require process context. */
1467         if (!process)
1468                 goto out;
1469         /* Handle attached ccw device. */
1470         switch (action) {
1471         case IO_SCH_ORPH_UNREG:
1472         case IO_SCH_ORPH_ATTACH:
1473                 /* Move ccw device to orphanage. */
1474                 rc = ccw_device_move_to_orph(cdev);
1475                 if (rc)
1476                         goto out;
1477                 break;
1478         case IO_SCH_UNREG_ATTACH:
1479                 spin_lock_irqsave(sch->lock, flags);
1480                 if (cdev->private->flags.resuming) {
1481                         /* Device will be handled later. */
1482                         rc = 0;
1483                         goto out_unlock;
1484                 }
1485                 sch_set_cdev(sch, NULL);
1486                 spin_unlock_irqrestore(sch->lock, flags);
1487                 /* Unregister ccw device. */
1488                 ccw_device_unregister(cdev);
1489                 break;
1490         default:
1491                 break;
1492         }
1493         /* Handle subchannel. */
1494         switch (action) {
1495         case IO_SCH_ORPH_UNREG:
1496         case IO_SCH_UNREG:
1497                 if (!cdev || !cdev->private->flags.resuming)
1498                         css_sch_device_unregister(sch);
1499                 break;
1500         case IO_SCH_ORPH_ATTACH:
1501         case IO_SCH_UNREG_ATTACH:
1502         case IO_SCH_ATTACH:
1503                 dev_id.ssid = sch->schid.ssid;
1504                 dev_id.devno = sch->schib.pmcw.dev;
1505                 cdev = get_ccwdev_by_dev_id(&dev_id);
1506                 if (!cdev) {
1507                         sch_create_and_recog_new_device(sch);
1508                         break;
1509                 }
1510                 rc = ccw_device_move_to_sch(cdev, sch);
1511                 if (rc) {
1512                         /* Release reference from get_ccwdev_by_dev_id() */
1513                         put_device(&cdev->dev);
1514                         goto out;
1515                 }
1516                 spin_lock_irqsave(sch->lock, flags);
1517                 ccw_device_trigger_reprobe(cdev);
1518                 spin_unlock_irqrestore(sch->lock, flags);
1519                 /* Release reference from get_ccwdev_by_dev_id() */
1520                 put_device(&cdev->dev);
1521                 break;
1522         default:
1523                 break;
1524         }
1525         return 0;
1526
1527 out_unlock:
1528         spin_unlock_irqrestore(sch->lock, flags);
1529 out:
1530         return rc;
1531 }
1532
1533 static void ccw_device_set_int_class(struct ccw_device *cdev)
1534 {
1535         struct ccw_driver *cdrv = cdev->drv;
1536
1537         /* Note: we interpret class 0 in this context as an uninitialized
1538          * field since it translates to a non-I/O interrupt class. */
1539         if (cdrv->int_class != 0)
1540                 cdev->private->int_class = cdrv->int_class;
1541         else
1542                 cdev->private->int_class = IRQIO_CIO;
1543 }
1544
1545 #ifdef CONFIG_CCW_CONSOLE
1546 int __init ccw_device_enable_console(struct ccw_device *cdev)
1547 {
1548         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1549         int rc;
1550
1551         if (!cdev->drv || !cdev->handler)
1552                 return -EINVAL;
1553
1554         io_subchannel_init_fields(sch);
1555         rc = cio_commit_config(sch);
1556         if (rc)
1557                 return rc;
1558         sch->driver = &io_subchannel_driver;
1559         io_subchannel_recog(cdev, sch);
1560         /* Now wait for the async. recognition to come to an end. */
1561         spin_lock_irq(cdev->ccwlock);
1562         while (!dev_fsm_final_state(cdev))
1563                 ccw_device_wait_idle(cdev);
1564
1565         /* Hold on to an extra reference while device is online. */
1566         get_device(&cdev->dev);
1567         rc = ccw_device_online(cdev);
1568         if (rc)
1569                 goto out_unlock;
1570
1571         while (!dev_fsm_final_state(cdev))
1572                 ccw_device_wait_idle(cdev);
1573
1574         if (cdev->private->state == DEV_STATE_ONLINE)
1575                 cdev->online = 1;
1576         else
1577                 rc = -EIO;
1578 out_unlock:
1579         spin_unlock_irq(cdev->ccwlock);
1580         if (rc) /* Give up online reference since onlining failed. */
1581                 put_device(&cdev->dev);
1582         return rc;
1583 }
1584
1585 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1586 {
1587         struct io_subchannel_private *io_priv;
1588         struct ccw_device *cdev;
1589         struct subchannel *sch;
1590
1591         sch = cio_probe_console();
1592         if (IS_ERR(sch))
1593                 return ERR_CAST(sch);
1594
1595         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1596         if (!io_priv) {
1597                 put_device(&sch->dev);
1598                 return ERR_PTR(-ENOMEM);
1599         }
1600         set_io_private(sch, io_priv);
1601         cdev = io_subchannel_create_ccwdev(sch);
1602         if (IS_ERR(cdev)) {
1603                 put_device(&sch->dev);
1604                 kfree(io_priv);
1605                 return cdev;
1606         }
1607         cdev->drv = drv;
1608         ccw_device_set_int_class(cdev);
1609         return cdev;
1610 }
1611
1612 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1613 {
1614         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1615         struct io_subchannel_private *io_priv = to_io_private(sch);
1616
1617         set_io_private(sch, NULL);
1618         put_device(&sch->dev);
1619         put_device(&cdev->dev);
1620         kfree(io_priv);
1621 }
1622
1623 /**
1624  * ccw_device_wait_idle() - busy wait for device to become idle
1625  * @cdev: ccw device
1626  *
1627  * Poll until activity control is zero, that is, no function or data
1628  * transfer is pending/active.
1629  * Called with device lock being held.
1630  */
1631 void ccw_device_wait_idle(struct ccw_device *cdev)
1632 {
1633         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1634
1635         while (1) {
1636                 cio_tsch(sch);
1637                 if (sch->schib.scsw.cmd.actl == 0)
1638                         break;
1639                 udelay_simple(100);
1640         }
1641 }
1642
1643 static int ccw_device_pm_restore(struct device *dev);
1644
1645 int ccw_device_force_console(struct ccw_device *cdev)
1646 {
1647         return ccw_device_pm_restore(&cdev->dev);
1648 }
1649 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1650 #endif
1651
1652 /*
1653  * get ccw_device matching the busid, but only if owned by cdrv
1654  */
1655 static int
1656 __ccwdev_check_busid(struct device *dev, void *id)
1657 {
1658         char *bus_id;
1659
1660         bus_id = id;
1661
1662         return (strcmp(bus_id, dev_name(dev)) == 0);
1663 }
1664
1665
1666 /**
1667  * get_ccwdev_by_busid() - obtain device from a bus id
1668  * @cdrv: driver the device is owned by
1669  * @bus_id: bus id of the device to be searched
1670  *
1671  * This function searches all devices owned by @cdrv for a device with a bus
1672  * id matching @bus_id.
1673  * Returns:
1674  *  If a match is found, its reference count of the found device is increased
1675  *  and it is returned; else %NULL is returned.
1676  */
1677 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1678                                        const char *bus_id)
1679 {
1680         struct device *dev;
1681
1682         dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
1683                                  __ccwdev_check_busid);
1684
1685         return dev ? to_ccwdev(dev) : NULL;
1686 }
1687
1688 /************************** device driver handling ************************/
1689
1690 /* This is the implementation of the ccw_driver class. The probe, remove
1691  * and release methods are initially very similar to the device_driver
1692  * implementations, with the difference that they have ccw_device
1693  * arguments.
1694  *
1695  * A ccw driver also contains the information that is needed for
1696  * device matching.
1697  */
1698 static int
1699 ccw_device_probe (struct device *dev)
1700 {
1701         struct ccw_device *cdev = to_ccwdev(dev);
1702         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1703         int ret;
1704
1705         cdev->drv = cdrv; /* to let the driver call _set_online */
1706         ccw_device_set_int_class(cdev);
1707         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1708         if (ret) {
1709                 cdev->drv = NULL;
1710                 cdev->private->int_class = IRQIO_CIO;
1711                 return ret;
1712         }
1713
1714         return 0;
1715 }
1716
1717 static int ccw_device_remove(struct device *dev)
1718 {
1719         struct ccw_device *cdev = to_ccwdev(dev);
1720         struct ccw_driver *cdrv = cdev->drv;
1721         struct subchannel *sch;
1722         int ret;
1723
1724         if (cdrv->remove)
1725                 cdrv->remove(cdev);
1726
1727         spin_lock_irq(cdev->ccwlock);
1728         if (cdev->online) {
1729                 cdev->online = 0;
1730                 ret = ccw_device_offline(cdev);
1731                 spin_unlock_irq(cdev->ccwlock);
1732                 if (ret == 0)
1733                         wait_event(cdev->private->wait_q,
1734                                    dev_fsm_final_state(cdev));
1735                 else
1736                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1737                                       "device 0.%x.%04x\n",
1738                                       ret, cdev->private->dev_id.ssid,
1739                                       cdev->private->dev_id.devno);
1740                 /* Give up reference obtained in ccw_device_set_online(). */
1741                 put_device(&cdev->dev);
1742                 spin_lock_irq(cdev->ccwlock);
1743         }
1744         ccw_device_set_timeout(cdev, 0);
1745         cdev->drv = NULL;
1746         cdev->private->int_class = IRQIO_CIO;
1747         sch = to_subchannel(cdev->dev.parent);
1748         spin_unlock_irq(cdev->ccwlock);
1749         io_subchannel_quiesce(sch);
1750         __disable_cmf(cdev);
1751
1752         return 0;
1753 }
1754
1755 static void ccw_device_shutdown(struct device *dev)
1756 {
1757         struct ccw_device *cdev;
1758
1759         cdev = to_ccwdev(dev);
1760         if (cdev->drv && cdev->drv->shutdown)
1761                 cdev->drv->shutdown(cdev);
1762         __disable_cmf(cdev);
1763 }
1764
1765 static int ccw_device_pm_prepare(struct device *dev)
1766 {
1767         struct ccw_device *cdev = to_ccwdev(dev);
1768
1769         if (work_pending(&cdev->private->todo_work))
1770                 return -EAGAIN;
1771         /* Fail while device is being set online/offline. */
1772         if (atomic_read(&cdev->private->onoff))
1773                 return -EAGAIN;
1774
1775         if (cdev->online && cdev->drv && cdev->drv->prepare)
1776                 return cdev->drv->prepare(cdev);
1777
1778         return 0;
1779 }
1780
1781 static void ccw_device_pm_complete(struct device *dev)
1782 {
1783         struct ccw_device *cdev = to_ccwdev(dev);
1784
1785         if (cdev->online && cdev->drv && cdev->drv->complete)
1786                 cdev->drv->complete(cdev);
1787 }
1788
1789 static int ccw_device_pm_freeze(struct device *dev)
1790 {
1791         struct ccw_device *cdev = to_ccwdev(dev);
1792         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1793         int ret, cm_enabled;
1794
1795         /* Fail suspend while device is in transistional state. */
1796         if (!dev_fsm_final_state(cdev))
1797                 return -EAGAIN;
1798         if (!cdev->online)
1799                 return 0;
1800         if (cdev->drv && cdev->drv->freeze) {
1801                 ret = cdev->drv->freeze(cdev);
1802                 if (ret)
1803                         return ret;
1804         }
1805
1806         spin_lock_irq(sch->lock);
1807         cm_enabled = cdev->private->cmb != NULL;
1808         spin_unlock_irq(sch->lock);
1809         if (cm_enabled) {
1810                 /* Don't have the css write on memory. */
1811                 ret = ccw_set_cmf(cdev, 0);
1812                 if (ret)
1813                         return ret;
1814         }
1815         /* From here on, disallow device driver I/O. */
1816         spin_lock_irq(sch->lock);
1817         ret = cio_disable_subchannel(sch);
1818         spin_unlock_irq(sch->lock);
1819
1820         return ret;
1821 }
1822
1823 static int ccw_device_pm_thaw(struct device *dev)
1824 {
1825         struct ccw_device *cdev = to_ccwdev(dev);
1826         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1827         int ret, cm_enabled;
1828
1829         if (!cdev->online)
1830                 return 0;
1831
1832         spin_lock_irq(sch->lock);
1833         /* Allow device driver I/O again. */
1834         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1835         cm_enabled = cdev->private->cmb != NULL;
1836         spin_unlock_irq(sch->lock);
1837         if (ret)
1838                 return ret;
1839
1840         if (cm_enabled) {
1841                 ret = ccw_set_cmf(cdev, 1);
1842                 if (ret)
1843                         return ret;
1844         }
1845
1846         if (cdev->drv && cdev->drv->thaw)
1847                 ret = cdev->drv->thaw(cdev);
1848
1849         return ret;
1850 }
1851
1852 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1853 {
1854         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1855
1856         spin_lock_irq(sch->lock);
1857         if (cio_is_console(sch->schid)) {
1858                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1859                 goto out_unlock;
1860         }
1861         /*
1862          * While we were sleeping, devices may have gone or become
1863          * available again. Kick re-detection.
1864          */
1865         cdev->private->flags.resuming = 1;
1866         cdev->private->path_new_mask = LPM_ANYPATH;
1867         css_sched_sch_todo(sch, SCH_TODO_EVAL);
1868         spin_unlock_irq(sch->lock);
1869         css_wait_for_slow_path();
1870
1871         /* cdev may have been moved to a different subchannel. */
1872         sch = to_subchannel(cdev->dev.parent);
1873         spin_lock_irq(sch->lock);
1874         if (cdev->private->state != DEV_STATE_ONLINE &&
1875             cdev->private->state != DEV_STATE_OFFLINE)
1876                 goto out_unlock;
1877
1878         ccw_device_recognition(cdev);
1879         spin_unlock_irq(sch->lock);
1880         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1881                    cdev->private->state == DEV_STATE_DISCONNECTED);
1882         spin_lock_irq(sch->lock);
1883
1884 out_unlock:
1885         cdev->private->flags.resuming = 0;
1886         spin_unlock_irq(sch->lock);
1887 }
1888
1889 static int resume_handle_boxed(struct ccw_device *cdev)
1890 {
1891         cdev->private->state = DEV_STATE_BOXED;
1892         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1893                 return 0;
1894         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1895         return -ENODEV;
1896 }
1897
1898 static int resume_handle_disc(struct ccw_device *cdev)
1899 {
1900         cdev->private->state = DEV_STATE_DISCONNECTED;
1901         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1902                 return 0;
1903         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1904         return -ENODEV;
1905 }
1906
1907 static int ccw_device_pm_restore(struct device *dev)
1908 {
1909         struct ccw_device *cdev = to_ccwdev(dev);
1910         struct subchannel *sch;
1911         int ret = 0;
1912
1913         __ccw_device_pm_restore(cdev);
1914         sch = to_subchannel(cdev->dev.parent);
1915         spin_lock_irq(sch->lock);
1916         if (cio_is_console(sch->schid))
1917                 goto out_restore;
1918
1919         /* check recognition results */
1920         switch (cdev->private->state) {
1921         case DEV_STATE_OFFLINE:
1922         case DEV_STATE_ONLINE:
1923                 cdev->private->flags.donotify = 0;
1924                 break;
1925         case DEV_STATE_BOXED:
1926                 ret = resume_handle_boxed(cdev);
1927                 if (ret)
1928                         goto out_unlock;
1929                 goto out_restore;
1930         default:
1931                 ret = resume_handle_disc(cdev);
1932                 if (ret)
1933                         goto out_unlock;
1934                 goto out_restore;
1935         }
1936         /* check if the device type has changed */
1937         if (!ccw_device_test_sense_data(cdev)) {
1938                 ccw_device_update_sense_data(cdev);
1939                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1940                 ret = -ENODEV;
1941                 goto out_unlock;
1942         }
1943         if (!cdev->online)
1944                 goto out_unlock;
1945
1946         if (ccw_device_online(cdev)) {
1947                 ret = resume_handle_disc(cdev);
1948                 if (ret)
1949                         goto out_unlock;
1950                 goto out_restore;
1951         }
1952         spin_unlock_irq(sch->lock);
1953         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1954         spin_lock_irq(sch->lock);
1955
1956         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1957                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1958                 ret = -ENODEV;
1959                 goto out_unlock;
1960         }
1961
1962         /* reenable cmf, if needed */
1963         if (cdev->private->cmb) {
1964                 spin_unlock_irq(sch->lock);
1965                 ret = ccw_set_cmf(cdev, 1);
1966                 spin_lock_irq(sch->lock);
1967                 if (ret) {
1968                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1969                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1970                                       cdev->private->dev_id.devno, ret);
1971                         ret = 0;
1972                 }
1973         }
1974
1975 out_restore:
1976         spin_unlock_irq(sch->lock);
1977         if (cdev->online && cdev->drv && cdev->drv->restore)
1978                 ret = cdev->drv->restore(cdev);
1979         return ret;
1980
1981 out_unlock:
1982         spin_unlock_irq(sch->lock);
1983         return ret;
1984 }
1985
1986 static const struct dev_pm_ops ccw_pm_ops = {
1987         .prepare = ccw_device_pm_prepare,
1988         .complete = ccw_device_pm_complete,
1989         .freeze = ccw_device_pm_freeze,
1990         .thaw = ccw_device_pm_thaw,
1991         .restore = ccw_device_pm_restore,
1992 };
1993
1994 static struct bus_type ccw_bus_type = {
1995         .name   = "ccw",
1996         .match  = ccw_bus_match,
1997         .uevent = ccw_uevent,
1998         .probe  = ccw_device_probe,
1999         .remove = ccw_device_remove,
2000         .shutdown = ccw_device_shutdown,
2001         .pm = &ccw_pm_ops,
2002 };
2003
2004 /**
2005  * ccw_driver_register() - register a ccw driver
2006  * @cdriver: driver to be registered
2007  *
2008  * This function is mainly a wrapper around driver_register().
2009  * Returns:
2010  *   %0 on success and a negative error value on failure.
2011  */
2012 int ccw_driver_register(struct ccw_driver *cdriver)
2013 {
2014         struct device_driver *drv = &cdriver->driver;
2015
2016         drv->bus = &ccw_bus_type;
2017
2018         return driver_register(drv);
2019 }
2020
2021 /**
2022  * ccw_driver_unregister() - deregister a ccw driver
2023  * @cdriver: driver to be deregistered
2024  *
2025  * This function is mainly a wrapper around driver_unregister().
2026  */
2027 void ccw_driver_unregister(struct ccw_driver *cdriver)
2028 {
2029         driver_unregister(&cdriver->driver);
2030 }
2031
2032 static void ccw_device_todo(struct work_struct *work)
2033 {
2034         struct ccw_device_private *priv;
2035         struct ccw_device *cdev;
2036         struct subchannel *sch;
2037         enum cdev_todo todo;
2038
2039         priv = container_of(work, struct ccw_device_private, todo_work);
2040         cdev = priv->cdev;
2041         sch = to_subchannel(cdev->dev.parent);
2042         /* Find out todo. */
2043         spin_lock_irq(cdev->ccwlock);
2044         todo = priv->todo;
2045         priv->todo = CDEV_TODO_NOTHING;
2046         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2047                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2048         spin_unlock_irq(cdev->ccwlock);
2049         /* Perform todo. */
2050         switch (todo) {
2051         case CDEV_TODO_ENABLE_CMF:
2052                 cmf_reenable(cdev);
2053                 break;
2054         case CDEV_TODO_REBIND:
2055                 ccw_device_do_unbind_bind(cdev);
2056                 break;
2057         case CDEV_TODO_REGISTER:
2058                 io_subchannel_register(cdev);
2059                 break;
2060         case CDEV_TODO_UNREG_EVAL:
2061                 if (!sch_is_pseudo_sch(sch))
2062                         css_schedule_eval(sch->schid);
2063                 /* fall-through */
2064         case CDEV_TODO_UNREG:
2065                 if (sch_is_pseudo_sch(sch))
2066                         ccw_device_unregister(cdev);
2067                 else
2068                         ccw_device_call_sch_unregister(cdev);
2069                 break;
2070         default:
2071                 break;
2072         }
2073         /* Release workqueue ref. */
2074         put_device(&cdev->dev);
2075 }
2076
2077 /**
2078  * ccw_device_sched_todo - schedule ccw device operation
2079  * @cdev: ccw device
2080  * @todo: todo
2081  *
2082  * Schedule the operation identified by @todo to be performed on the slow path
2083  * workqueue. Do nothing if another operation with higher priority is already
2084  * scheduled. Needs to be called with ccwdev lock held.
2085  */
2086 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2087 {
2088         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2089                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2090                       todo);
2091         if (cdev->private->todo >= todo)
2092                 return;
2093         cdev->private->todo = todo;
2094         /* Get workqueue ref. */
2095         if (!get_device(&cdev->dev))
2096                 return;
2097         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2098                 /* Already queued, release workqueue ref. */
2099                 put_device(&cdev->dev);
2100         }
2101 }
2102
2103 /**
2104  * ccw_device_siosl() - initiate logging
2105  * @cdev: ccw device
2106  *
2107  * This function is used to invoke model-dependent logging within the channel
2108  * subsystem.
2109  */
2110 int ccw_device_siosl(struct ccw_device *cdev)
2111 {
2112         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2113
2114         return chsc_siosl(sch->schid);
2115 }
2116 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2117
2118 EXPORT_SYMBOL(ccw_device_set_online);
2119 EXPORT_SYMBOL(ccw_device_set_offline);
2120 EXPORT_SYMBOL(ccw_driver_register);
2121 EXPORT_SYMBOL(ccw_driver_unregister);
2122 EXPORT_SYMBOL(get_ccwdev_by_busid);