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 #include <linux/dma-mapping.h>
  28
  29 #include <asm/ccwdev.h>
  30 #include <asm/cio.h>
  31 #include <asm/param.h>          /* HZ */
  32 #include <asm/cmb.h>
  33 #include <asm/isc.h>
  34
  35 #include "chp.h"
  36 #include "cio.h"
  37 #include "cio_debug.h"
  38 #include "css.h"
  39 #include "device.h"
  40 #include "ioasm.h"
  41 #include "io_sch.h"
  42 #include "blacklist.h"
  43 #include "chsc.h"
  44
  45 static struct timer_list recovery_timer;
  46 static DEFINE_SPINLOCK(recovery_lock);
  47 static int recovery_phase;
  48 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  49
  50 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
  51 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
  52 static struct bus_type ccw_bus_type;
  53
  54 /******************* bus type handling ***********************/
  55
  56 /* The Linux driver model distinguishes between a bus type and
  57  * the bus itself. Of course we only have one channel
  58  * subsystem driver and one channel system per machine, but
  59  * we still use the abstraction. T.R. says it's a good idea. */
  60 static int
  61 ccw_bus_match (struct device * dev, struct device_driver * drv)
  62 {
  63         struct ccw_device *cdev = to_ccwdev(dev);
  64         struct ccw_driver *cdrv = to_ccwdrv(drv);
  65         const struct ccw_device_id *ids = cdrv->ids, *found;
  66
  67         if (!ids)
  68                 return 0;
  69
  70         found = ccw_device_id_match(ids, &cdev->id);
  71         if (!found)
  72                 return 0;
  73
  74         cdev->id.driver_info = found->driver_info;
  75
  76         return 1;
  77 }
  78
  79 /* Store modalias string delimited by prefix/suffix string into buffer with
  80  * specified size. Return length of resulting string (excluding trailing '\0')
  81  * even if string doesn't fit buffer (snprintf semantics). */
  82 static int snprint_alias(char *buf, size_t size,
  83                          struct ccw_device_id *id, const char *suffix)
  84 {
  85         int len;
  86
  87         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  88         if (len > size)
  89                 return len;
  90         buf += len;
  91         size -= len;
  92
  93         if (id->dev_type != 0)
  94                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  95                                 id->dev_model, suffix);
  96         else
  97                 len += snprintf(buf, size, "dtdm%s", suffix);
  98
  99         return len;
 100 }
 101
 102 /* Set up environment variables for ccw device uevent. Return 0 on success,
 103  * non-zero otherwise. */
 104 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
 105 {
 106         struct ccw_device *cdev = to_ccwdev(dev);
 107         struct ccw_device_id *id = &(cdev->id);
 108         int ret;
 109         char modalias_buf[30];
 110
 111         /* CU_TYPE= */
 112         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 113         if (ret)
 114                 return ret;
 115
 116         /* CU_MODEL= */
 117         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 118         if (ret)
 119                 return ret;
 120
 121         /* The next two can be zero, that's ok for us */
 122         /* DEV_TYPE= */
 123         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 124         if (ret)
 125                 return ret;
 126
 127         /* DEV_MODEL= */
 128         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 129         if (ret)
 130                 return ret;
 131
 132         /* MODALIAS=  */
 133         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 134         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 135         return ret;
 136 }
 137
 138 static void io_subchannel_irq(struct subchannel *);
 139 static int io_subchannel_probe(struct subchannel *);
 140 static int io_subchannel_remove(struct subchannel *);
 141 static void io_subchannel_shutdown(struct subchannel *);
 142 static int io_subchannel_sch_event(struct subchannel *, int);
 143 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 144                                    int);
 145 static void recovery_func(struct timer_list *unused);
 146
 147 static struct css_device_id io_subchannel_ids[] = {
 148         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 149         { /* end of list */ },
 150 };
 151
 152 static int io_subchannel_prepare(struct subchannel *sch)
 153 {
 154         struct ccw_device *cdev;
 155         /*
 156          * Don't allow suspend while a ccw device registration
 157          * is still outstanding.
 158          */
 159         cdev = sch_get_cdev(sch);
 160         if (cdev && !device_is_registered(&cdev->dev))
 161                 return -EAGAIN;
 162         return 0;
 163 }
 164
 165 static int io_subchannel_settle(void)
 166 {
 167         int ret;
 168
 169         ret = wait_event_interruptible(ccw_device_init_wq,
 170                                 atomic_read(&ccw_device_init_count) == 0);
 171         if (ret)
 172                 return -EINTR;
 173         flush_workqueue(cio_work_q);
 174         return 0;
 175 }
 176
 177 static struct css_driver io_subchannel_driver = {
 178         .drv = {
 179                 .owner = THIS_MODULE,
 180                 .name = "io_subchannel",
 181         },
 182         .subchannel_type = io_subchannel_ids,
 183         .irq = io_subchannel_irq,
 184         .sch_event = io_subchannel_sch_event,
 185         .chp_event = io_subchannel_chp_event,
 186         .probe = io_subchannel_probe,
 187         .remove = io_subchannel_remove,
 188         .shutdown = io_subchannel_shutdown,
 189         .prepare = io_subchannel_prepare,
 190         .settle = io_subchannel_settle,
 191 };
 192
 193 int __init io_subchannel_init(void)
 194 {
 195         int ret;
 196
 197         timer_setup(&recovery_timer, recovery_func, 0);
 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 static ssize_t
 212 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 213 {
 214         struct ccw_device *cdev = to_ccwdev(dev);
 215         struct ccw_device_id *id = &(cdev->id);
 216
 217         if (id->dev_type != 0)
 218                 return sprintf(buf, "%04x/%02x\n",
 219                                 id->dev_type, id->dev_model);
 220         else
 221                 return sprintf(buf, "n/a\n");
 222 }
 223
 224 static ssize_t
 225 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 226 {
 227         struct ccw_device *cdev = to_ccwdev(dev);
 228         struct ccw_device_id *id = &(cdev->id);
 229
 230         return sprintf(buf, "%04x/%02x\n",
 231                        id->cu_type, id->cu_model);
 232 }
 233
 234 static ssize_t
 235 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 236 {
 237         struct ccw_device *cdev = to_ccwdev(dev);
 238         struct ccw_device_id *id = &(cdev->id);
 239         int len;
 240
 241         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 242
 243         return len > PAGE_SIZE ? PAGE_SIZE : len;
 244 }
 245
 246 static ssize_t
 247 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 248 {
 249         struct ccw_device *cdev = to_ccwdev(dev);
 250
 251         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 252 }
 253
 254 int ccw_device_is_orphan(struct ccw_device *cdev)
 255 {
 256         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 257 }
 258
 259 static void ccw_device_unregister(struct ccw_device *cdev)
 260 {
 261         if (device_is_registered(&cdev->dev)) {
 262                 /* Undo device_add(). */
 263                 device_del(&cdev->dev);
 264         }
 265         if (cdev->private->flags.initialized) {
 266                 cdev->private->flags.initialized = 0;
 267                 /* Release reference from device_initialize(). */
 268                 put_device(&cdev->dev);
 269         }
 270 }
 271
 272 static void io_subchannel_quiesce(struct subchannel *);
 273
 274 /**
 275  * ccw_device_set_offline() - disable a ccw device for I/O
 276  * @cdev: target ccw device
 277  *
 278  * This function calls the driver's set_offline() function for @cdev, if
 279  * given, and then disables @cdev.
 280  * Returns:
 281  *   %0 on success and a negative error value on failure.
 282  * Context:
 283  *  enabled, ccw device lock not held
 284  */
 285 int ccw_device_set_offline(struct ccw_device *cdev)
 286 {
 287         struct subchannel *sch;
 288         int ret, state;
 289
 290         if (!cdev)
 291                 return -ENODEV;
 292         if (!cdev->online || !cdev->drv)
 293                 return -EINVAL;
 294
 295         if (cdev->drv->set_offline) {
 296                 ret = cdev->drv->set_offline(cdev);
 297                 if (ret != 0)
 298                         return ret;
 299         }
 300         spin_lock_irq(cdev->ccwlock);
 301         sch = to_subchannel(cdev->dev.parent);
 302         cdev->online = 0;
 303         /* Wait until a final state or DISCONNECTED is reached */
 304         while (!dev_fsm_final_state(cdev) &&
 305                cdev->private->state != DEV_STATE_DISCONNECTED) {
 306                 spin_unlock_irq(cdev->ccwlock);
 307                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 308                            cdev->private->state == DEV_STATE_DISCONNECTED));
 309                 spin_lock_irq(cdev->ccwlock);
 310         }
 311         do {
 312                 ret = ccw_device_offline(cdev);
 313                 if (!ret)
 314                         break;
 315                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 316                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 317                               cdev->private->dev_id.devno);
 318                 if (ret != -EBUSY)
 319                         goto error;
 320                 state = cdev->private->state;
 321                 spin_unlock_irq(cdev->ccwlock);
 322                 io_subchannel_quiesce(sch);
 323                 spin_lock_irq(cdev->ccwlock);
 324                 cdev->private->state = state;
 325         } while (ret == -EBUSY);
 326         spin_unlock_irq(cdev->ccwlock);
 327         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 328                    cdev->private->state == DEV_STATE_DISCONNECTED));
 329         /* Inform the user if set offline failed. */
 330         if (cdev->private->state == DEV_STATE_BOXED) {
 331                 pr_warn("%s: The device entered boxed state while being set offline\n",
 332                         dev_name(&cdev->dev));
 333         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 334                 pr_warn("%s: The device stopped operating while being set offline\n",
 335                         dev_name(&cdev->dev));
 336         }
 337         /* Give up reference from ccw_device_set_online(). */
 338         put_device(&cdev->dev);
 339         return 0;
 340
 341 error:
 342         cdev->private->state = DEV_STATE_OFFLINE;
 343         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 344         spin_unlock_irq(cdev->ccwlock);
 345         /* Give up reference from ccw_device_set_online(). */
 346         put_device(&cdev->dev);
 347         return -ENODEV;
 348 }
 349
 350 /**
 351  * ccw_device_set_online() - enable a ccw device for I/O
 352  * @cdev: target ccw device
 353  *
 354  * This function first enables @cdev and then calls the driver's set_online()
 355  * function for @cdev, if given. If set_online() returns an error, @cdev is
 356  * disabled again.
 357  * Returns:
 358  *   %0 on success and a negative error value on failure.
 359  * Context:
 360  *  enabled, ccw device lock not held
 361  */
 362 int ccw_device_set_online(struct ccw_device *cdev)
 363 {
 364         int ret;
 365         int ret2;
 366
 367         if (!cdev)
 368                 return -ENODEV;
 369         if (cdev->online || !cdev->drv)
 370                 return -EINVAL;
 371         /* Hold on to an extra reference while device is online. */
 372         if (!get_device(&cdev->dev))
 373                 return -ENODEV;
 374
 375         spin_lock_irq(cdev->ccwlock);
 376         ret = ccw_device_online(cdev);
 377         spin_unlock_irq(cdev->ccwlock);
 378         if (ret == 0)
 379                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 380         else {
 381                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 382                               "device 0.%x.%04x\n",
 383                               ret, cdev->private->dev_id.ssid,
 384                               cdev->private->dev_id.devno);
 385                 /* Give up online reference since onlining failed. */
 386                 put_device(&cdev->dev);
 387                 return ret;
 388         }
 389         spin_lock_irq(cdev->ccwlock);
 390         /* Check if online processing was successful */
 391         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 392             (cdev->private->state != DEV_STATE_W4SENSE)) {
 393                 spin_unlock_irq(cdev->ccwlock);
 394                 /* Inform the user that set online failed. */
 395                 if (cdev->private->state == DEV_STATE_BOXED) {
 396                         pr_warn("%s: Setting the device online failed because it is boxed\n",
 397                                 dev_name(&cdev->dev));
 398                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 399                         pr_warn("%s: Setting the device online failed because it is not operational\n",
 400                                 dev_name(&cdev->dev));
 401                 }
 402                 /* Give up online reference since onlining failed. */
 403                 put_device(&cdev->dev);
 404                 return -ENODEV;
 405         }
 406         spin_unlock_irq(cdev->ccwlock);
 407         if (cdev->drv->set_online)
 408                 ret = cdev->drv->set_online(cdev);
 409         if (ret)
 410                 goto rollback;
 411
 412         spin_lock_irq(cdev->ccwlock);
 413         cdev->online = 1;
 414         spin_unlock_irq(cdev->ccwlock);
 415         return 0;
 416
 417 rollback:
 418         spin_lock_irq(cdev->ccwlock);
 419         /* Wait until a final state or DISCONNECTED is reached */
 420         while (!dev_fsm_final_state(cdev) &&
 421                cdev->private->state != DEV_STATE_DISCONNECTED) {
 422                 spin_unlock_irq(cdev->ccwlock);
 423                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 424                            cdev->private->state == DEV_STATE_DISCONNECTED));
 425                 spin_lock_irq(cdev->ccwlock);
 426         }
 427         ret2 = ccw_device_offline(cdev);
 428         if (ret2)
 429                 goto error;
 430         spin_unlock_irq(cdev->ccwlock);
 431         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 432                    cdev->private->state == DEV_STATE_DISCONNECTED));
 433         /* Give up online reference since onlining failed. */
 434         put_device(&cdev->dev);
 435         return ret;
 436
 437 error:
 438         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 439                       "device 0.%x.%04x\n",
 440                       ret2, cdev->private->dev_id.ssid,
 441                       cdev->private->dev_id.devno);
 442         cdev->private->state = DEV_STATE_OFFLINE;
 443         spin_unlock_irq(cdev->ccwlock);
 444         /* Give up online reference since onlining failed. */
 445         put_device(&cdev->dev);
 446         return ret;
 447 }
 448
 449 static int online_store_handle_offline(struct ccw_device *cdev)
 450 {
 451         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 452                 spin_lock_irq(cdev->ccwlock);
 453                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 454                 spin_unlock_irq(cdev->ccwlock);
 455                 return 0;
 456         }
 457         if (cdev->drv && cdev->drv->set_offline)
 458                 return ccw_device_set_offline(cdev);
 459         return -EINVAL;
 460 }
 461
 462 static int online_store_recog_and_online(struct ccw_device *cdev)
 463 {
 464         /* Do device recognition, if needed. */
 465         if (cdev->private->state == DEV_STATE_BOXED) {
 466                 spin_lock_irq(cdev->ccwlock);
 467                 ccw_device_recognition(cdev);
 468                 spin_unlock_irq(cdev->ccwlock);
 469                 wait_event(cdev->private->wait_q,
 470                            cdev->private->flags.recog_done);
 471                 if (cdev->private->state != DEV_STATE_OFFLINE)
 472                         /* recognition failed */
 473                         return -EAGAIN;
 474         }
 475         if (cdev->drv && cdev->drv->set_online)
 476                 return ccw_device_set_online(cdev);
 477         return -EINVAL;
 478 }
 479
 480 static int online_store_handle_online(struct ccw_device *cdev, int force)
 481 {
 482         int ret;
 483
 484         ret = online_store_recog_and_online(cdev);
 485         if (ret && !force)
 486                 return ret;
 487         if (force && cdev->private->state == DEV_STATE_BOXED) {
 488                 ret = ccw_device_stlck(cdev);
 489                 if (ret)
 490                         return ret;
 491                 if (cdev->id.cu_type == 0)
 492                         cdev->private->state = DEV_STATE_NOT_OPER;
 493                 ret = online_store_recog_and_online(cdev);
 494                 if (ret)
 495                         return ret;
 496         }
 497         return 0;
 498 }
 499
 500 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 501                              const char *buf, size_t count)
 502 {
 503         struct ccw_device *cdev = to_ccwdev(dev);
 504         int force, ret;
 505         unsigned long i;
 506
 507         /* Prevent conflict between multiple on-/offline processing requests. */
 508         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 509                 return -EAGAIN;
 510         /* Prevent conflict between internal I/Os and on-/offline processing. */
 511         if (!dev_fsm_final_state(cdev) &&
 512             cdev->private->state != DEV_STATE_DISCONNECTED) {
 513                 ret = -EAGAIN;
 514                 goto out;
 515         }
 516         /* Prevent conflict between pending work and on-/offline processing.*/
 517         if (work_pending(&cdev->private->todo_work)) {
 518                 ret = -EAGAIN;
 519                 goto out;
 520         }
 521         if (!strncmp(buf, "force\n", count)) {
 522                 force = 1;
 523                 i = 1;
 524                 ret = 0;
 525         } else {
 526                 force = 0;
 527                 ret = kstrtoul(buf, 16, &i);
 528         }
 529         if (ret)
 530                 goto out;
 531
 532         device_lock(dev);
 533         switch (i) {
 534         case 0:
 535                 ret = online_store_handle_offline(cdev);
 536                 break;
 537         case 1:
 538                 ret = online_store_handle_online(cdev, force);
 539                 break;
 540         default:
 541                 ret = -EINVAL;
 542         }
 543         device_unlock(dev);
 544
 545 out:
 546         atomic_set(&cdev->private->onoff, 0);
 547         return (ret < 0) ? ret : count;
 548 }
 549
 550 static ssize_t
 551 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 552 {
 553         struct ccw_device *cdev = to_ccwdev(dev);
 554         struct subchannel *sch;
 555
 556         if (ccw_device_is_orphan(cdev))
 557                 return sprintf(buf, "no device\n");
 558         switch (cdev->private->state) {
 559         case DEV_STATE_BOXED:
 560                 return sprintf(buf, "boxed\n");
 561         case DEV_STATE_DISCONNECTED:
 562         case DEV_STATE_DISCONNECTED_SENSE_ID:
 563         case DEV_STATE_NOT_OPER:
 564                 sch = to_subchannel(dev->parent);
 565                 if (!sch->lpm)
 566                         return sprintf(buf, "no path\n");
 567                 else
 568                         return sprintf(buf, "no device\n");
 569         default:
 570                 /* All other states considered fine. */
 571                 return sprintf(buf, "good\n");
 572         }
 573 }
 574
 575 static ssize_t
 576 initiate_logging(struct device *dev, struct device_attribute *attr,
 577                  const char *buf, size_t count)
 578 {
 579         struct subchannel *sch = to_subchannel(dev);
 580         int rc;
 581
 582         rc = chsc_siosl(sch->schid);
 583         if (rc < 0) {
 584                 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
 585                         sch->schid.ssid, sch->schid.sch_no, rc);
 586                 return rc;
 587         }
 588         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 589                   sch->schid.ssid, sch->schid.sch_no);
 590         return count;
 591 }
 592
 593 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 594                         char *buf)
 595 {
 596         struct subchannel *sch = to_subchannel(dev);
 597
 598         return sprintf(buf, "%02x\n", sch->vpm);
 599 }
 600
 601 static DEVICE_ATTR_RO(devtype);
 602 static DEVICE_ATTR_RO(cutype);
 603 static DEVICE_ATTR_RO(modalias);
 604 static DEVICE_ATTR_RW(online);
 605 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 606 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 607 static DEVICE_ATTR_RO(vpm);
 608
 609 static struct attribute *io_subchannel_attrs[] = {
 610         &dev_attr_logging.attr,
 611         &dev_attr_vpm.attr,
 612         NULL,
 613 };
 614
 615 static const struct attribute_group io_subchannel_attr_group = {
 616         .attrs = io_subchannel_attrs,
 617 };
 618
 619 static struct attribute * ccwdev_attrs[] = {
 620         &dev_attr_devtype.attr,
 621         &dev_attr_cutype.attr,
 622         &dev_attr_modalias.attr,
 623         &dev_attr_online.attr,
 624         &dev_attr_cmb_enable.attr,
 625         &dev_attr_availability.attr,
 626         NULL,
 627 };
 628
 629 static const struct attribute_group ccwdev_attr_group = {
 630         .attrs = ccwdev_attrs,
 631 };
 632
 633 static const struct attribute_group *ccwdev_attr_groups[] = {
 634         &ccwdev_attr_group,
 635         NULL,
 636 };
 637
 638 static int ccw_device_add(struct ccw_device *cdev)
 639 {
 640         struct device *dev = &cdev->dev;
 641
 642         dev->bus = &ccw_bus_type;
 643         return device_add(dev);
 644 }
 645
 646 static int match_dev_id(struct device *dev, const void *data)
 647 {
 648         struct ccw_device *cdev = to_ccwdev(dev);
 649         struct ccw_dev_id *dev_id = (void *)data;
 650
 651         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 652 }
 653
 654 /**
 655  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 656  * @dev_id: id of the device to be searched
 657  *
 658  * This function searches all devices attached to the ccw bus for a device
 659  * matching @dev_id.
 660  * Returns:
 661  *  If a device is found its reference count is increased and returned;
 662  *  else %NULL is returned.
 663  */
 664 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 665 {
 666         struct device *dev;
 667
 668         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 669
 670         return dev ? to_ccwdev(dev) : NULL;
 671 }
 672 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 673
 674 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 675 {
 676         int ret;
 677
 678         if (device_is_registered(&cdev->dev)) {
 679                 device_release_driver(&cdev->dev);
 680                 ret = device_attach(&cdev->dev);
 681                 WARN_ON(ret == -ENODEV);
 682         }
 683 }
 684
 685 static void
 686 ccw_device_release(struct device *dev)
 687 {
 688         struct ccw_device *cdev;
 689
 690         cdev = to_ccwdev(dev);
 691         cio_gp_dma_free(cdev->private->dma_pool, cdev->private->dma_area,
 692                         sizeof(*cdev->private->dma_area));
 693         cio_gp_dma_destroy(cdev->private->dma_pool, &cdev->dev);
 694         /* Release reference of parent subchannel. */
 695         put_device(cdev->dev.parent);
 696         kfree(cdev->private);
 697         kfree(cdev);
 698 }
 699
 700 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 701 {
 702         struct ccw_device *cdev;
 703         struct gen_pool *dma_pool;
 704
 705         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 706         if (!cdev)
 707                 goto err_cdev;
 708         cdev->private = kzalloc(sizeof(struct ccw_device_private),
 709                                 GFP_KERNEL | GFP_DMA);
 710         if (!cdev->private)
 711                 goto err_priv;
 712         cdev->dev.coherent_dma_mask = sch->dev.coherent_dma_mask;
 713         cdev->dev.dma_mask = sch->dev.dma_mask;
 714         dma_pool = cio_gp_dma_create(&cdev->dev, 1);
 715         if (!dma_pool)
 716                 goto err_dma_pool;
 717         cdev->private->dma_pool = dma_pool;
 718         cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
 719                                         sizeof(*cdev->private->dma_area));
 720         if (!cdev->private->dma_area)
 721                 goto err_dma_area;
 722         return cdev;
 723 err_dma_area:
 724         cio_gp_dma_destroy(dma_pool, &cdev->dev);
 725 err_dma_pool:
 726         kfree(cdev->private);
 727 err_priv:
 728         kfree(cdev);
 729 err_cdev:
 730         return ERR_PTR(-ENOMEM);
 731 }
 732
 733 static void ccw_device_todo(struct work_struct *work);
 734
 735 static int io_subchannel_initialize_dev(struct subchannel *sch,
 736                                         struct ccw_device *cdev)
 737 {
 738         struct ccw_device_private *priv = cdev->private;
 739         int ret;
 740
 741         priv->cdev = cdev;
 742         priv->int_class = IRQIO_CIO;
 743         priv->state = DEV_STATE_NOT_OPER;
 744         priv->dev_id.devno = sch->schib.pmcw.dev;
 745         priv->dev_id.ssid = sch->schid.ssid;
 746
 747         INIT_WORK(&priv->todo_work, ccw_device_todo);
 748         INIT_LIST_HEAD(&priv->cmb_list);
 749         init_waitqueue_head(&priv->wait_q);
 750         timer_setup(&priv->timer, ccw_device_timeout, 0);
 751
 752         atomic_set(&priv->onoff, 0);
 753         cdev->ccwlock = sch->lock;
 754         cdev->dev.parent = &sch->dev;
 755         cdev->dev.release = ccw_device_release;
 756         cdev->dev.groups = ccwdev_attr_groups;
 757         /* Do first half of device_register. */
 758         device_initialize(&cdev->dev);
 759         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 760                            cdev->private->dev_id.devno);
 761         if (ret)
 762                 goto out_put;
 763         if (!get_device(&sch->dev)) {
 764                 ret = -ENODEV;
 765                 goto out_put;
 766         }
 767         priv->flags.initialized = 1;
 768         spin_lock_irq(sch->lock);
 769         sch_set_cdev(sch, cdev);
 770         spin_unlock_irq(sch->lock);
 771         return 0;
 772
 773 out_put:
 774         /* Release reference from device_initialize(). */
 775         put_device(&cdev->dev);
 776         return ret;
 777 }
 778
 779 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 780 {
 781         struct ccw_device *cdev;
 782         int ret;
 783
 784         cdev = io_subchannel_allocate_dev(sch);
 785         if (!IS_ERR(cdev)) {
 786                 ret = io_subchannel_initialize_dev(sch, cdev);
 787                 if (ret)
 788                         cdev = ERR_PTR(ret);
 789         }
 790         return cdev;
 791 }
 792
 793 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 794
 795 static void sch_create_and_recog_new_device(struct subchannel *sch)
 796 {
 797         struct ccw_device *cdev;
 798
 799         /* Need to allocate a new ccw device. */
 800         cdev = io_subchannel_create_ccwdev(sch);
 801         if (IS_ERR(cdev)) {
 802                 /* OK, we did everything we could... */
 803                 css_sch_device_unregister(sch);
 804                 return;
 805         }
 806         /* Start recognition for the new ccw device. */
 807         io_subchannel_recog(cdev, sch);
 808 }
 809
 810 /*
 811  * Register recognized device.
 812  */
 813 static void io_subchannel_register(struct ccw_device *cdev)
 814 {
 815         struct subchannel *sch;
 816         int ret, adjust_init_count = 1;
 817         unsigned long flags;
 818
 819         sch = to_subchannel(cdev->dev.parent);
 820         /*
 821          * Check if subchannel is still registered. It may have become
 822          * unregistered if a machine check hit us after finishing
 823          * device recognition but before the register work could be
 824          * queued.
 825          */
 826         if (!device_is_registered(&sch->dev))
 827                 goto out_err;
 828         css_update_ssd_info(sch);
 829         /*
 830          * io_subchannel_register() will also be called after device
 831          * recognition has been done for a boxed device (which will already
 832          * be registered). We need to reprobe since we may now have sense id
 833          * information.
 834          */
 835         if (device_is_registered(&cdev->dev)) {
 836                 if (!cdev->drv) {
 837                         ret = device_reprobe(&cdev->dev);
 838                         if (ret)
 839                                 /* We can't do much here. */
 840                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 841                                               " %d for 0.%x.%04x\n", ret,
 842                                               cdev->private->dev_id.ssid,
 843                                               cdev->private->dev_id.devno);
 844                 }
 845                 adjust_init_count = 0;
 846                 goto out;
 847         }
 848         /*
 849          * Now we know this subchannel will stay, we can throw
 850          * our delayed uevent.
 851          */
 852         if (dev_get_uevent_suppress(&sch->dev)) {
 853                 dev_set_uevent_suppress(&sch->dev, 0);
 854                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 855         }
 856         /* make it known to the system */
 857         ret = ccw_device_add(cdev);
 858         if (ret) {
 859                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 860                               cdev->private->dev_id.ssid,
 861                               cdev->private->dev_id.devno, ret);
 862                 spin_lock_irqsave(sch->lock, flags);
 863                 sch_set_cdev(sch, NULL);
 864                 spin_unlock_irqrestore(sch->lock, flags);
 865                 /* Release initial device reference. */
 866                 put_device(&cdev->dev);
 867                 goto out_err;
 868         }
 869 out:
 870         cdev->private->flags.recog_done = 1;
 871         wake_up(&cdev->private->wait_q);
 872 out_err:
 873         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 874                 wake_up(&ccw_device_init_wq);
 875 }
 876
 877 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 878 {
 879         struct subchannel *sch;
 880
 881         /* Get subchannel reference for local processing. */
 882         if (!get_device(cdev->dev.parent))
 883                 return;
 884         sch = to_subchannel(cdev->dev.parent);
 885         css_sch_device_unregister(sch);
 886         /* Release subchannel reference for local processing. */
 887         put_device(&sch->dev);
 888 }
 889
 890 /*
 891  * subchannel recognition done. Called from the state machine.
 892  */
 893 void
 894 io_subchannel_recog_done(struct ccw_device *cdev)
 895 {
 896         if (css_init_done == 0) {
 897                 cdev->private->flags.recog_done = 1;
 898                 return;
 899         }
 900         switch (cdev->private->state) {
 901         case DEV_STATE_BOXED:
 902                 /* Device did not respond in time. */
 903         case DEV_STATE_NOT_OPER:
 904                 cdev->private->flags.recog_done = 1;
 905                 /* Remove device found not operational. */
 906                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 907                 if (atomic_dec_and_test(&ccw_device_init_count))
 908                         wake_up(&ccw_device_init_wq);
 909                 break;
 910         case DEV_STATE_OFFLINE:
 911                 /*
 912                  * We can't register the device in interrupt context so
 913                  * we schedule a work item.
 914                  */
 915                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 916                 break;
 917         }
 918 }
 919
 920 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 921 {
 922         /* Increase counter of devices currently in recognition. */
 923         atomic_inc(&ccw_device_init_count);
 924
 925         /* Start async. device sensing. */
 926         spin_lock_irq(sch->lock);
 927         ccw_device_recognition(cdev);
 928         spin_unlock_irq(sch->lock);
 929 }
 930
 931 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 932                                   struct subchannel *sch)
 933 {
 934         struct subchannel *old_sch;
 935         int rc, old_enabled = 0;
 936
 937         old_sch = to_subchannel(cdev->dev.parent);
 938         /* Obtain child reference for new parent. */
 939         if (!get_device(&sch->dev))
 940                 return -ENODEV;
 941
 942         if (!sch_is_pseudo_sch(old_sch)) {
 943                 spin_lock_irq(old_sch->lock);
 944                 old_enabled = old_sch->schib.pmcw.ena;
 945                 rc = 0;
 946                 if (old_enabled)
 947                         rc = cio_disable_subchannel(old_sch);
 948                 spin_unlock_irq(old_sch->lock);
 949                 if (rc == -EBUSY) {
 950                         /* Release child reference for new parent. */
 951                         put_device(&sch->dev);
 952                         return rc;
 953                 }
 954         }
 955
 956         mutex_lock(&sch->reg_mutex);
 957         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 958         mutex_unlock(&sch->reg_mutex);
 959         if (rc) {
 960                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 961                               cdev->private->dev_id.ssid,
 962                               cdev->private->dev_id.devno, sch->schid.ssid,
 963                               sch->schib.pmcw.dev, rc);
 964                 if (old_enabled) {
 965                         /* Try to reenable the old subchannel. */
 966                         spin_lock_irq(old_sch->lock);
 967                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 968                         spin_unlock_irq(old_sch->lock);
 969                 }
 970                 /* Release child reference for new parent. */
 971                 put_device(&sch->dev);
 972                 return rc;
 973         }
 974         /* Clean up old subchannel. */
 975         if (!sch_is_pseudo_sch(old_sch)) {
 976                 spin_lock_irq(old_sch->lock);
 977                 sch_set_cdev(old_sch, NULL);
 978                 spin_unlock_irq(old_sch->lock);
 979                 css_schedule_eval(old_sch->schid);
 980         }
 981         /* Release child reference for old parent. */
 982         put_device(&old_sch->dev);
 983         /* Initialize new subchannel. */
 984         spin_lock_irq(sch->lock);
 985         cdev->ccwlock = sch->lock;
 986         if (!sch_is_pseudo_sch(sch))
 987                 sch_set_cdev(sch, cdev);
 988         spin_unlock_irq(sch->lock);
 989         if (!sch_is_pseudo_sch(sch))
 990                 css_update_ssd_info(sch);
 991         return 0;
 992 }
 993
 994 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 995 {
 996         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 997         struct channel_subsystem *css = to_css(sch->dev.parent);
 998
 999         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
1000 }
1001
1002 static void io_subchannel_irq(struct subchannel *sch)
1003 {
1004         struct ccw_device *cdev;
1005
1006         cdev = sch_get_cdev(sch);
1007
1008         CIO_TRACE_EVENT(6, "IRQ");
1009         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1010         if (cdev)
1011                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1012         else
1013                 inc_irq_stat(IRQIO_CIO);
1014 }
1015
1016 void io_subchannel_init_config(struct subchannel *sch)
1017 {
1018         memset(&sch->config, 0, sizeof(sch->config));
1019         sch->config.csense = 1;
1020 }
1021
1022 static void io_subchannel_init_fields(struct subchannel *sch)
1023 {
1024         if (cio_is_console(sch->schid))
1025                 sch->opm = 0xff;
1026         else
1027                 sch->opm = chp_get_sch_opm(sch);
1028         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1029         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1030
1031         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1032                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1033                       sch->schib.pmcw.dev, sch->schid.ssid,
1034                       sch->schid.sch_no, sch->schib.pmcw.pim,
1035                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1036
1037         io_subchannel_init_config(sch);
1038 }
1039
1040 /*
1041  * Note: We always return 0 so that we bind to the device even on error.
1042  * This is needed so that our remove function is called on unregister.
1043  */
1044 static int io_subchannel_probe(struct subchannel *sch)
1045 {
1046         struct io_subchannel_private *io_priv;
1047         struct ccw_device *cdev;
1048         int rc;
1049
1050         if (cio_is_console(sch->schid)) {
1051                 rc = sysfs_create_group(&sch->dev.kobj,
1052                                         &io_subchannel_attr_group);
1053                 if (rc)
1054                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1055                                       "attributes for subchannel "
1056                                       "0.%x.%04x (rc=%d)\n",
1057                                       sch->schid.ssid, sch->schid.sch_no, rc);
1058                 /*
1059                  * The console subchannel already has an associated ccw_device.
1060                  * Throw the delayed uevent for the subchannel, register
1061                  * the ccw_device and exit.
1062                  */
1063                 if (dev_get_uevent_suppress(&sch->dev)) {
1064                         /* should always be the case for the console */
1065                         dev_set_uevent_suppress(&sch->dev, 0);
1066                         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1067                 }
1068                 cdev = sch_get_cdev(sch);
1069                 rc = ccw_device_add(cdev);
1070                 if (rc) {
1071                         /* Release online reference. */
1072                         put_device(&cdev->dev);
1073                         goto out_schedule;
1074                 }
1075                 if (atomic_dec_and_test(&ccw_device_init_count))
1076                         wake_up(&ccw_device_init_wq);
1077                 return 0;
1078         }
1079         io_subchannel_init_fields(sch);
1080         rc = cio_commit_config(sch);
1081         if (rc)
1082                 goto out_schedule;
1083         rc = sysfs_create_group(&sch->dev.kobj,
1084                                 &io_subchannel_attr_group);
1085         if (rc)
1086                 goto out_schedule;
1087         /* Allocate I/O subchannel private data. */
1088         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1089         if (!io_priv)
1090                 goto out_schedule;
1091
1092         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1093                                 sizeof(*io_priv->dma_area),
1094                                 &io_priv->dma_area_dma, GFP_KERNEL);
1095         if (!io_priv->dma_area) {
1096                 kfree(io_priv);
1097                 goto out_schedule;
1098         }
1099
1100         set_io_private(sch, io_priv);
1101         css_schedule_eval(sch->schid);
1102         return 0;
1103
1104 out_schedule:
1105         spin_lock_irq(sch->lock);
1106         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1107         spin_unlock_irq(sch->lock);
1108         return 0;
1109 }
1110
1111 static int io_subchannel_remove(struct subchannel *sch)
1112 {
1113         struct io_subchannel_private *io_priv = to_io_private(sch);
1114         struct ccw_device *cdev;
1115
1116         cdev = sch_get_cdev(sch);
1117         if (!cdev)
1118                 goto out_free;
1119
1120         ccw_device_unregister(cdev);
1121         spin_lock_irq(sch->lock);
1122         sch_set_cdev(sch, NULL);
1123         set_io_private(sch, NULL);
1124         spin_unlock_irq(sch->lock);
1125 out_free:
1126         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1127                           io_priv->dma_area, io_priv->dma_area_dma);
1128         kfree(io_priv);
1129         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1130         return 0;
1131 }
1132
1133 static void io_subchannel_verify(struct subchannel *sch)
1134 {
1135         struct ccw_device *cdev;
1136
1137         cdev = sch_get_cdev(sch);
1138         if (cdev)
1139                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1140 }
1141
1142 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1143 {
1144         struct ccw_device *cdev;
1145
1146         cdev = sch_get_cdev(sch);
1147         if (!cdev)
1148                 return;
1149         if (cio_update_schib(sch))
1150                 goto err;
1151         /* Check for I/O on path. */
1152         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1153                 goto out;
1154         if (cdev->private->state == DEV_STATE_ONLINE) {
1155                 ccw_device_kill_io(cdev);
1156                 goto out;
1157         }
1158         if (cio_clear(sch))
1159                 goto err;
1160 out:
1161         /* Trigger path verification. */
1162         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1163         return;
1164
1165 err:
1166         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1167 }
1168
1169 static int io_subchannel_chp_event(struct subchannel *sch,
1170                                    struct chp_link *link, int event)
1171 {
1172         struct ccw_device *cdev = sch_get_cdev(sch);
1173         int mask;
1174
1175         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1176         if (!mask)
1177                 return 0;
1178         switch (event) {
1179         case CHP_VARY_OFF:
1180                 sch->opm &= ~mask;
1181                 sch->lpm &= ~mask;
1182                 if (cdev)
1183                         cdev->private->path_gone_mask |= mask;
1184                 io_subchannel_terminate_path(sch, mask);
1185                 break;
1186         case CHP_VARY_ON:
1187                 sch->opm |= mask;
1188                 sch->lpm |= mask;
1189                 if (cdev)
1190                         cdev->private->path_new_mask |= mask;
1191                 io_subchannel_verify(sch);
1192                 break;
1193         case CHP_OFFLINE:
1194                 if (cio_update_schib(sch))
1195                         return -ENODEV;
1196                 if (cdev)
1197                         cdev->private->path_gone_mask |= mask;
1198                 io_subchannel_terminate_path(sch, mask);
1199                 break;
1200         case CHP_ONLINE:
1201                 if (cio_update_schib(sch))
1202                         return -ENODEV;
1203                 sch->lpm |= mask & sch->opm;
1204                 if (cdev)
1205                         cdev->private->path_new_mask |= mask;
1206                 io_subchannel_verify(sch);
1207                 break;
1208         }
1209         return 0;
1210 }
1211
1212 static void io_subchannel_quiesce(struct subchannel *sch)
1213 {
1214         struct ccw_device *cdev;
1215         int ret;
1216
1217         spin_lock_irq(sch->lock);
1218         cdev = sch_get_cdev(sch);
1219         if (cio_is_console(sch->schid))
1220                 goto out_unlock;
1221         if (!sch->schib.pmcw.ena)
1222                 goto out_unlock;
1223         ret = cio_disable_subchannel(sch);
1224         if (ret != -EBUSY)
1225                 goto out_unlock;
1226         if (cdev->handler)
1227                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1228         while (ret == -EBUSY) {
1229                 cdev->private->state = DEV_STATE_QUIESCE;
1230                 cdev->private->iretry = 255;
1231                 ret = ccw_device_cancel_halt_clear(cdev);
1232                 if (ret == -EBUSY) {
1233                         ccw_device_set_timeout(cdev, HZ/10);
1234                         spin_unlock_irq(sch->lock);
1235                         wait_event(cdev->private->wait_q,
1236                                    cdev->private->state != DEV_STATE_QUIESCE);
1237                         spin_lock_irq(sch->lock);
1238                 }
1239                 ret = cio_disable_subchannel(sch);
1240         }
1241 out_unlock:
1242         spin_unlock_irq(sch->lock);
1243 }
1244
1245 static void io_subchannel_shutdown(struct subchannel *sch)
1246 {
1247         io_subchannel_quiesce(sch);
1248 }
1249
1250 static int device_is_disconnected(struct ccw_device *cdev)
1251 {
1252         if (!cdev)
1253                 return 0;
1254         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1255                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1256 }
1257
1258 static int recovery_check(struct device *dev, void *data)
1259 {
1260         struct ccw_device *cdev = to_ccwdev(dev);
1261         struct subchannel *sch;
1262         int *redo = data;
1263
1264         spin_lock_irq(cdev->ccwlock);
1265         switch (cdev->private->state) {
1266         case DEV_STATE_ONLINE:
1267                 sch = to_subchannel(cdev->dev.parent);
1268                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1269                         break;
1270                 fallthrough;
1271         case DEV_STATE_DISCONNECTED:
1272                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1273                               cdev->private->dev_id.ssid,
1274                               cdev->private->dev_id.devno);
1275                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1276                 *redo = 1;
1277                 break;
1278         case DEV_STATE_DISCONNECTED_SENSE_ID:
1279                 *redo = 1;
1280                 break;
1281         }
1282         spin_unlock_irq(cdev->ccwlock);
1283
1284         return 0;
1285 }
1286
1287 static void recovery_work_func(struct work_struct *unused)
1288 {
1289         int redo = 0;
1290
1291         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1292         if (redo) {
1293                 spin_lock_irq(&recovery_lock);
1294                 if (!timer_pending(&recovery_timer)) {
1295                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1296                                 recovery_phase++;
1297                         mod_timer(&recovery_timer, jiffies +
1298                                   recovery_delay[recovery_phase] * HZ);
1299                 }
1300                 spin_unlock_irq(&recovery_lock);
1301         } else
1302                 CIO_MSG_EVENT(3, "recovery: end\n");
1303 }
1304
1305 static DECLARE_WORK(recovery_work, recovery_work_func);
1306
1307 static void recovery_func(struct timer_list *unused)
1308 {
1309         /*
1310          * We can't do our recovery in softirq context and it's not
1311          * performance critical, so we schedule it.
1312          */
1313         schedule_work(&recovery_work);
1314 }
1315
1316 void ccw_device_schedule_recovery(void)
1317 {
1318         unsigned long flags;
1319
1320         CIO_MSG_EVENT(3, "recovery: schedule\n");
1321         spin_lock_irqsave(&recovery_lock, flags);
1322         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1323                 recovery_phase = 0;
1324                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1325         }
1326         spin_unlock_irqrestore(&recovery_lock, flags);
1327 }
1328
1329 static int purge_fn(struct device *dev, void *data)
1330 {
1331         struct ccw_device *cdev = to_ccwdev(dev);
1332         struct ccw_dev_id *id = &cdev->private->dev_id;
1333
1334         spin_lock_irq(cdev->ccwlock);
1335         if (is_blacklisted(id->ssid, id->devno) &&
1336             (cdev->private->state == DEV_STATE_OFFLINE) &&
1337             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1338                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1339                               id->devno);
1340                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1341                 atomic_set(&cdev->private->onoff, 0);
1342         }
1343         spin_unlock_irq(cdev->ccwlock);
1344         /* Abort loop in case of pending signal. */
1345         if (signal_pending(current))
1346                 return -EINTR;
1347
1348         return 0;
1349 }
1350
1351 /**
1352  * ccw_purge_blacklisted - purge unused, blacklisted devices
1353  *
1354  * Unregister all ccw devices that are offline and on the blacklist.
1355  */
1356 int ccw_purge_blacklisted(void)
1357 {
1358         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1359         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1360         return 0;
1361 }
1362
1363 void ccw_device_set_disconnected(struct ccw_device *cdev)
1364 {
1365         if (!cdev)
1366                 return;
1367         ccw_device_set_timeout(cdev, 0);
1368         cdev->private->flags.fake_irb = 0;
1369         cdev->private->state = DEV_STATE_DISCONNECTED;
1370         if (cdev->online)
1371                 ccw_device_schedule_recovery();
1372 }
1373
1374 void ccw_device_set_notoper(struct ccw_device *cdev)
1375 {
1376         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1377
1378         CIO_TRACE_EVENT(2, "notoper");
1379         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1380         ccw_device_set_timeout(cdev, 0);
1381         cio_disable_subchannel(sch);
1382         cdev->private->state = DEV_STATE_NOT_OPER;
1383 }
1384
1385 enum io_sch_action {
1386         IO_SCH_UNREG,
1387         IO_SCH_ORPH_UNREG,
1388         IO_SCH_ATTACH,
1389         IO_SCH_UNREG_ATTACH,
1390         IO_SCH_ORPH_ATTACH,
1391         IO_SCH_REPROBE,
1392         IO_SCH_VERIFY,
1393         IO_SCH_DISC,
1394         IO_SCH_NOP,
1395 };
1396
1397 static enum io_sch_action sch_get_action(struct subchannel *sch)
1398 {
1399         struct ccw_device *cdev;
1400
1401         cdev = sch_get_cdev(sch);
1402         if (cio_update_schib(sch)) {
1403                 /* Not operational. */
1404                 if (!cdev)
1405                         return IO_SCH_UNREG;
1406                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1407                         return IO_SCH_UNREG;
1408                 return IO_SCH_ORPH_UNREG;
1409         }
1410         /* Operational. */
1411         if (!cdev)
1412                 return IO_SCH_ATTACH;
1413         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1414                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1415                         return IO_SCH_UNREG_ATTACH;
1416                 return IO_SCH_ORPH_ATTACH;
1417         }
1418         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1419                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1420                         return IO_SCH_UNREG;
1421                 return IO_SCH_DISC;
1422         }
1423         if (device_is_disconnected(cdev))
1424                 return IO_SCH_REPROBE;
1425         if (cdev->online && !cdev->private->flags.resuming)
1426                 return IO_SCH_VERIFY;
1427         if (cdev->private->state == DEV_STATE_NOT_OPER)
1428                 return IO_SCH_UNREG_ATTACH;
1429         return IO_SCH_NOP;
1430 }
1431
1432 /**
1433  * io_subchannel_sch_event - process subchannel event
1434  * @sch: subchannel
1435  * @process: non-zero if function is called in process context
1436  *
1437  * An unspecified event occurred for this subchannel. Adjust data according
1438  * to the current operational state of the subchannel and device. Return
1439  * zero when the event has been handled sufficiently or -EAGAIN when this
1440  * function should be called again in process context.
1441  */
1442 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1443 {
1444         unsigned long flags;
1445         struct ccw_device *cdev;
1446         struct ccw_dev_id dev_id;
1447         enum io_sch_action action;
1448         int rc = -EAGAIN;
1449
1450         spin_lock_irqsave(sch->lock, flags);
1451         if (!device_is_registered(&sch->dev))
1452                 goto out_unlock;
1453         if (work_pending(&sch->todo_work))
1454                 goto out_unlock;
1455         cdev = sch_get_cdev(sch);
1456         if (cdev && work_pending(&cdev->private->todo_work))
1457                 goto out_unlock;
1458         action = sch_get_action(sch);
1459         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1460                       sch->schid.ssid, sch->schid.sch_no, process,
1461                       action);
1462         /* Perform immediate actions while holding the lock. */
1463         switch (action) {
1464         case IO_SCH_REPROBE:
1465                 /* Trigger device recognition. */
1466                 ccw_device_trigger_reprobe(cdev);
1467                 rc = 0;
1468                 goto out_unlock;
1469         case IO_SCH_VERIFY:
1470                 /* Trigger path verification. */
1471                 io_subchannel_verify(sch);
1472                 rc = 0;
1473                 goto out_unlock;
1474         case IO_SCH_DISC:
1475                 ccw_device_set_disconnected(cdev);
1476                 rc = 0;
1477                 goto out_unlock;
1478         case IO_SCH_ORPH_UNREG:
1479         case IO_SCH_ORPH_ATTACH:
1480                 ccw_device_set_disconnected(cdev);
1481                 break;
1482         case IO_SCH_UNREG_ATTACH:
1483         case IO_SCH_UNREG:
1484                 if (!cdev)
1485                         break;
1486                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1487                         /*
1488                          * Note: delayed work triggered by this event
1489                          * and repeated calls to sch_event are synchronized
1490                          * by the above check for work_pending(cdev).
1491                          */
1492                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1493                 } else
1494                         ccw_device_set_notoper(cdev);
1495                 break;
1496         case IO_SCH_NOP:
1497                 rc = 0;
1498                 goto out_unlock;
1499         default:
1500                 break;
1501         }
1502         spin_unlock_irqrestore(sch->lock, flags);
1503         /* All other actions require process context. */
1504         if (!process)
1505                 goto out;
1506         /* Handle attached ccw device. */
1507         switch (action) {
1508         case IO_SCH_ORPH_UNREG:
1509         case IO_SCH_ORPH_ATTACH:
1510                 /* Move ccw device to orphanage. */
1511                 rc = ccw_device_move_to_orph(cdev);
1512                 if (rc)
1513                         goto out;
1514                 break;
1515         case IO_SCH_UNREG_ATTACH:
1516                 spin_lock_irqsave(sch->lock, flags);
1517                 if (cdev->private->flags.resuming) {
1518                         /* Device will be handled later. */
1519                         rc = 0;
1520                         goto out_unlock;
1521                 }
1522                 sch_set_cdev(sch, NULL);
1523                 spin_unlock_irqrestore(sch->lock, flags);
1524                 /* Unregister ccw device. */
1525                 ccw_device_unregister(cdev);
1526                 break;
1527         default:
1528                 break;
1529         }
1530         /* Handle subchannel. */
1531         switch (action) {
1532         case IO_SCH_ORPH_UNREG:
1533         case IO_SCH_UNREG:
1534                 if (!cdev || !cdev->private->flags.resuming)
1535                         css_sch_device_unregister(sch);
1536                 break;
1537         case IO_SCH_ORPH_ATTACH:
1538         case IO_SCH_UNREG_ATTACH:
1539         case IO_SCH_ATTACH:
1540                 dev_id.ssid = sch->schid.ssid;
1541                 dev_id.devno = sch->schib.pmcw.dev;
1542                 cdev = get_ccwdev_by_dev_id(&dev_id);
1543                 if (!cdev) {
1544                         sch_create_and_recog_new_device(sch);
1545                         break;
1546                 }
1547                 rc = ccw_device_move_to_sch(cdev, sch);
1548                 if (rc) {
1549                         /* Release reference from get_ccwdev_by_dev_id() */
1550                         put_device(&cdev->dev);
1551                         goto out;
1552                 }
1553                 spin_lock_irqsave(sch->lock, flags);
1554                 ccw_device_trigger_reprobe(cdev);
1555                 spin_unlock_irqrestore(sch->lock, flags);
1556                 /* Release reference from get_ccwdev_by_dev_id() */
1557                 put_device(&cdev->dev);
1558                 break;
1559         default:
1560                 break;
1561         }
1562         return 0;
1563
1564 out_unlock:
1565         spin_unlock_irqrestore(sch->lock, flags);
1566 out:
1567         return rc;
1568 }
1569
1570 static void ccw_device_set_int_class(struct ccw_device *cdev)
1571 {
1572         struct ccw_driver *cdrv = cdev->drv;
1573
1574         /* Note: we interpret class 0 in this context as an uninitialized
1575          * field since it translates to a non-I/O interrupt class. */
1576         if (cdrv->int_class != 0)
1577                 cdev->private->int_class = cdrv->int_class;
1578         else
1579                 cdev->private->int_class = IRQIO_CIO;
1580 }
1581
1582 #ifdef CONFIG_CCW_CONSOLE
1583 int __init ccw_device_enable_console(struct ccw_device *cdev)
1584 {
1585         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1586         int rc;
1587
1588         if (!cdev->drv || !cdev->handler)
1589                 return -EINVAL;
1590
1591         io_subchannel_init_fields(sch);
1592         rc = cio_commit_config(sch);
1593         if (rc)
1594                 return rc;
1595         sch->driver = &io_subchannel_driver;
1596         io_subchannel_recog(cdev, sch);
1597         /* Now wait for the async. recognition to come to an end. */
1598         spin_lock_irq(cdev->ccwlock);
1599         while (!dev_fsm_final_state(cdev))
1600                 ccw_device_wait_idle(cdev);
1601
1602         /* Hold on to an extra reference while device is online. */
1603         get_device(&cdev->dev);
1604         rc = ccw_device_online(cdev);
1605         if (rc)
1606                 goto out_unlock;
1607
1608         while (!dev_fsm_final_state(cdev))
1609                 ccw_device_wait_idle(cdev);
1610
1611         if (cdev->private->state == DEV_STATE_ONLINE)
1612                 cdev->online = 1;
1613         else
1614                 rc = -EIO;
1615 out_unlock:
1616         spin_unlock_irq(cdev->ccwlock);
1617         if (rc) /* Give up online reference since onlining failed. */
1618                 put_device(&cdev->dev);
1619         return rc;
1620 }
1621
1622 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1623 {
1624         struct io_subchannel_private *io_priv;
1625         struct ccw_device *cdev;
1626         struct subchannel *sch;
1627
1628         sch = cio_probe_console();
1629         if (IS_ERR(sch))
1630                 return ERR_CAST(sch);
1631
1632         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1633         if (!io_priv)
1634                 goto err_priv;
1635         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1636                                 sizeof(*io_priv->dma_area),
1637                                 &io_priv->dma_area_dma, GFP_KERNEL);
1638         if (!io_priv->dma_area)
1639                 goto err_dma_area;
1640         set_io_private(sch, io_priv);
1641         cdev = io_subchannel_create_ccwdev(sch);
1642         if (IS_ERR(cdev)) {
1643                 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1644                                   io_priv->dma_area, io_priv->dma_area_dma);
1645                 set_io_private(sch, NULL);
1646                 put_device(&sch->dev);
1647                 kfree(io_priv);
1648                 return cdev;
1649         }
1650         cdev->drv = drv;
1651         ccw_device_set_int_class(cdev);
1652         return cdev;
1653
1654 err_dma_area:
1655         kfree(io_priv);
1656 err_priv:
1657         put_device(&sch->dev);
1658         return ERR_PTR(-ENOMEM);
1659 }
1660
1661 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1662 {
1663         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1664         struct io_subchannel_private *io_priv = to_io_private(sch);
1665
1666         set_io_private(sch, NULL);
1667         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1668                           io_priv->dma_area, io_priv->dma_area_dma);
1669         put_device(&sch->dev);
1670         put_device(&cdev->dev);
1671         kfree(io_priv);
1672 }
1673
1674 /**
1675  * ccw_device_wait_idle() - busy wait for device to become idle
1676  * @cdev: ccw device
1677  *
1678  * Poll until activity control is zero, that is, no function or data
1679  * transfer is pending/active.
1680  * Called with device lock being held.
1681  */
1682 void ccw_device_wait_idle(struct ccw_device *cdev)
1683 {
1684         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1685
1686         while (1) {
1687                 cio_tsch(sch);
1688                 if (sch->schib.scsw.cmd.actl == 0)
1689                         break;
1690                 udelay_simple(100);
1691         }
1692 }
1693
1694 static int ccw_device_pm_restore(struct device *dev);
1695
1696 int ccw_device_force_console(struct ccw_device *cdev)
1697 {
1698         return ccw_device_pm_restore(&cdev->dev);
1699 }
1700 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1701 #endif
1702
1703 /**
1704  * get_ccwdev_by_busid() - obtain device from a bus id
1705  * @cdrv: driver the device is owned by
1706  * @bus_id: bus id of the device to be searched
1707  *
1708  * This function searches all devices owned by @cdrv for a device with a bus
1709  * id matching @bus_id.
1710  * Returns:
1711  *  If a match is found, its reference count of the found device is increased
1712  *  and it is returned; else %NULL is returned.
1713  */
1714 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1715                                        const char *bus_id)
1716 {
1717         struct device *dev;
1718
1719         dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1720
1721         return dev ? to_ccwdev(dev) : NULL;
1722 }
1723
1724 /************************** device driver handling ************************/
1725
1726 /* This is the implementation of the ccw_driver class. The probe, remove
1727  * and release methods are initially very similar to the device_driver
1728  * implementations, with the difference that they have ccw_device
1729  * arguments.
1730  *
1731  * A ccw driver also contains the information that is needed for
1732  * device matching.
1733  */
1734 static int
1735 ccw_device_probe (struct device *dev)
1736 {
1737         struct ccw_device *cdev = to_ccwdev(dev);
1738         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1739         int ret;
1740
1741         cdev->drv = cdrv; /* to let the driver call _set_online */
1742         ccw_device_set_int_class(cdev);
1743         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1744         if (ret) {
1745                 cdev->drv = NULL;
1746                 cdev->private->int_class = IRQIO_CIO;
1747                 return ret;
1748         }
1749
1750         return 0;
1751 }
1752
1753 static int ccw_device_remove(struct device *dev)
1754 {
1755         struct ccw_device *cdev = to_ccwdev(dev);
1756         struct ccw_driver *cdrv = cdev->drv;
1757         struct subchannel *sch;
1758         int ret;
1759
1760         if (cdrv->remove)
1761                 cdrv->remove(cdev);
1762
1763         spin_lock_irq(cdev->ccwlock);
1764         if (cdev->online) {
1765                 cdev->online = 0;
1766                 ret = ccw_device_offline(cdev);
1767                 spin_unlock_irq(cdev->ccwlock);
1768                 if (ret == 0)
1769                         wait_event(cdev->private->wait_q,
1770                                    dev_fsm_final_state(cdev));
1771                 else
1772                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1773                                       "device 0.%x.%04x\n",
1774                                       ret, cdev->private->dev_id.ssid,
1775                                       cdev->private->dev_id.devno);
1776                 /* Give up reference obtained in ccw_device_set_online(). */
1777                 put_device(&cdev->dev);
1778                 spin_lock_irq(cdev->ccwlock);
1779         }
1780         ccw_device_set_timeout(cdev, 0);
1781         cdev->drv = NULL;
1782         cdev->private->int_class = IRQIO_CIO;
1783         sch = to_subchannel(cdev->dev.parent);
1784         spin_unlock_irq(cdev->ccwlock);
1785         io_subchannel_quiesce(sch);
1786         __disable_cmf(cdev);
1787
1788         return 0;
1789 }
1790
1791 static void ccw_device_shutdown(struct device *dev)
1792 {
1793         struct ccw_device *cdev;
1794
1795         cdev = to_ccwdev(dev);
1796         if (cdev->drv && cdev->drv->shutdown)
1797                 cdev->drv->shutdown(cdev);
1798         __disable_cmf(cdev);
1799 }
1800
1801 static int ccw_device_pm_prepare(struct device *dev)
1802 {
1803         struct ccw_device *cdev = to_ccwdev(dev);
1804
1805         if (work_pending(&cdev->private->todo_work))
1806                 return -EAGAIN;
1807         /* Fail while device is being set online/offline. */
1808         if (atomic_read(&cdev->private->onoff))
1809                 return -EAGAIN;
1810
1811         if (cdev->online && cdev->drv && cdev->drv->prepare)
1812                 return cdev->drv->prepare(cdev);
1813
1814         return 0;
1815 }
1816
1817 static void ccw_device_pm_complete(struct device *dev)
1818 {
1819         struct ccw_device *cdev = to_ccwdev(dev);
1820
1821         if (cdev->online && cdev->drv && cdev->drv->complete)
1822                 cdev->drv->complete(cdev);
1823 }
1824
1825 static int ccw_device_pm_freeze(struct device *dev)
1826 {
1827         struct ccw_device *cdev = to_ccwdev(dev);
1828         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1829         int ret, cm_enabled;
1830
1831         /* Fail suspend while device is in transistional state. */
1832         if (!dev_fsm_final_state(cdev))
1833                 return -EAGAIN;
1834         if (!cdev->online)
1835                 return 0;
1836         if (cdev->drv && cdev->drv->freeze) {
1837                 ret = cdev->drv->freeze(cdev);
1838                 if (ret)
1839                         return ret;
1840         }
1841
1842         spin_lock_irq(sch->lock);
1843         cm_enabled = cdev->private->cmb != NULL;
1844         spin_unlock_irq(sch->lock);
1845         if (cm_enabled) {
1846                 /* Don't have the css write on memory. */
1847                 ret = ccw_set_cmf(cdev, 0);
1848                 if (ret)
1849                         return ret;
1850         }
1851         /* From here on, disallow device driver I/O. */
1852         spin_lock_irq(sch->lock);
1853         ret = cio_disable_subchannel(sch);
1854         spin_unlock_irq(sch->lock);
1855
1856         return ret;
1857 }
1858
1859 static int ccw_device_pm_thaw(struct device *dev)
1860 {
1861         struct ccw_device *cdev = to_ccwdev(dev);
1862         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1863         int ret, cm_enabled;
1864
1865         if (!cdev->online)
1866                 return 0;
1867
1868         spin_lock_irq(sch->lock);
1869         /* Allow device driver I/O again. */
1870         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1871         cm_enabled = cdev->private->cmb != NULL;
1872         spin_unlock_irq(sch->lock);
1873         if (ret)
1874                 return ret;
1875
1876         if (cm_enabled) {
1877                 ret = ccw_set_cmf(cdev, 1);
1878                 if (ret)
1879                         return ret;
1880         }
1881
1882         if (cdev->drv && cdev->drv->thaw)
1883                 ret = cdev->drv->thaw(cdev);
1884
1885         return ret;
1886 }
1887
1888 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1889 {
1890         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1891
1892         spin_lock_irq(sch->lock);
1893         if (cio_is_console(sch->schid)) {
1894                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1895                 goto out_unlock;
1896         }
1897         /*
1898          * While we were sleeping, devices may have gone or become
1899          * available again. Kick re-detection.
1900          */
1901         cdev->private->flags.resuming = 1;
1902         cdev->private->path_new_mask = LPM_ANYPATH;
1903         css_sched_sch_todo(sch, SCH_TODO_EVAL);
1904         spin_unlock_irq(sch->lock);
1905         css_wait_for_slow_path();
1906
1907         /* cdev may have been moved to a different subchannel. */
1908         sch = to_subchannel(cdev->dev.parent);
1909         spin_lock_irq(sch->lock);
1910         if (cdev->private->state != DEV_STATE_ONLINE &&
1911             cdev->private->state != DEV_STATE_OFFLINE)
1912                 goto out_unlock;
1913
1914         ccw_device_recognition(cdev);
1915         spin_unlock_irq(sch->lock);
1916         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1917                    cdev->private->state == DEV_STATE_DISCONNECTED);
1918         spin_lock_irq(sch->lock);
1919
1920 out_unlock:
1921         cdev->private->flags.resuming = 0;
1922         spin_unlock_irq(sch->lock);
1923 }
1924
1925 static int resume_handle_boxed(struct ccw_device *cdev)
1926 {
1927         cdev->private->state = DEV_STATE_BOXED;
1928         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1929                 return 0;
1930         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1931         return -ENODEV;
1932 }
1933
1934 static int resume_handle_disc(struct ccw_device *cdev)
1935 {
1936         cdev->private->state = DEV_STATE_DISCONNECTED;
1937         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1938                 return 0;
1939         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1940         return -ENODEV;
1941 }
1942
1943 static int ccw_device_pm_restore(struct device *dev)
1944 {
1945         struct ccw_device *cdev = to_ccwdev(dev);
1946         struct subchannel *sch;
1947         int ret = 0;
1948
1949         __ccw_device_pm_restore(cdev);
1950         sch = to_subchannel(cdev->dev.parent);
1951         spin_lock_irq(sch->lock);
1952         if (cio_is_console(sch->schid))
1953                 goto out_restore;
1954
1955         /* check recognition results */
1956         switch (cdev->private->state) {
1957         case DEV_STATE_OFFLINE:
1958         case DEV_STATE_ONLINE:
1959                 cdev->private->flags.donotify = 0;
1960                 break;
1961         case DEV_STATE_BOXED:
1962                 ret = resume_handle_boxed(cdev);
1963                 if (ret)
1964                         goto out_unlock;
1965                 goto out_restore;
1966         default:
1967                 ret = resume_handle_disc(cdev);
1968                 if (ret)
1969                         goto out_unlock;
1970                 goto out_restore;
1971         }
1972         /* check if the device type has changed */
1973         if (!ccw_device_test_sense_data(cdev)) {
1974                 ccw_device_update_sense_data(cdev);
1975                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1976                 ret = -ENODEV;
1977                 goto out_unlock;
1978         }
1979         if (!cdev->online)
1980                 goto out_unlock;
1981
1982         if (ccw_device_online(cdev)) {
1983                 ret = resume_handle_disc(cdev);
1984                 if (ret)
1985                         goto out_unlock;
1986                 goto out_restore;
1987         }
1988         spin_unlock_irq(sch->lock);
1989         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1990         spin_lock_irq(sch->lock);
1991
1992         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1993                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1994                 ret = -ENODEV;
1995                 goto out_unlock;
1996         }
1997
1998         /* reenable cmf, if needed */
1999         if (cdev->private->cmb) {
2000                 spin_unlock_irq(sch->lock);
2001                 ret = ccw_set_cmf(cdev, 1);
2002                 spin_lock_irq(sch->lock);
2003                 if (ret) {
2004                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
2005                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
2006                                       cdev->private->dev_id.devno, ret);
2007                         ret = 0;
2008                 }
2009         }
2010
2011 out_restore:
2012         spin_unlock_irq(sch->lock);
2013         if (cdev->online && cdev->drv && cdev->drv->restore)
2014                 ret = cdev->drv->restore(cdev);
2015         return ret;
2016
2017 out_unlock:
2018         spin_unlock_irq(sch->lock);
2019         return ret;
2020 }
2021
2022 static const struct dev_pm_ops ccw_pm_ops = {
2023         .prepare = ccw_device_pm_prepare,
2024         .complete = ccw_device_pm_complete,
2025         .freeze = ccw_device_pm_freeze,
2026         .thaw = ccw_device_pm_thaw,
2027         .restore = ccw_device_pm_restore,
2028 };
2029
2030 static struct bus_type ccw_bus_type = {
2031         .name   = "ccw",
2032         .match  = ccw_bus_match,
2033         .uevent = ccw_uevent,
2034         .probe  = ccw_device_probe,
2035         .remove = ccw_device_remove,
2036         .shutdown = ccw_device_shutdown,
2037         .pm = &ccw_pm_ops,
2038 };
2039
2040 /**
2041  * ccw_driver_register() - register a ccw driver
2042  * @cdriver: driver to be registered
2043  *
2044  * This function is mainly a wrapper around driver_register().
2045  * Returns:
2046  *   %0 on success and a negative error value on failure.
2047  */
2048 int ccw_driver_register(struct ccw_driver *cdriver)
2049 {
2050         struct device_driver *drv = &cdriver->driver;
2051
2052         drv->bus = &ccw_bus_type;
2053
2054         return driver_register(drv);
2055 }
2056
2057 /**
2058  * ccw_driver_unregister() - deregister a ccw driver
2059  * @cdriver: driver to be deregistered
2060  *
2061  * This function is mainly a wrapper around driver_unregister().
2062  */
2063 void ccw_driver_unregister(struct ccw_driver *cdriver)
2064 {
2065         driver_unregister(&cdriver->driver);
2066 }
2067
2068 static void ccw_device_todo(struct work_struct *work)
2069 {
2070         struct ccw_device_private *priv;
2071         struct ccw_device *cdev;
2072         struct subchannel *sch;
2073         enum cdev_todo todo;
2074
2075         priv = container_of(work, struct ccw_device_private, todo_work);
2076         cdev = priv->cdev;
2077         sch = to_subchannel(cdev->dev.parent);
2078         /* Find out todo. */
2079         spin_lock_irq(cdev->ccwlock);
2080         todo = priv->todo;
2081         priv->todo = CDEV_TODO_NOTHING;
2082         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2083                       priv->dev_id.ssid, priv->dev_id.devno, todo);
2084         spin_unlock_irq(cdev->ccwlock);
2085         /* Perform todo. */
2086         switch (todo) {
2087         case CDEV_TODO_ENABLE_CMF:
2088                 cmf_reenable(cdev);
2089                 break;
2090         case CDEV_TODO_REBIND:
2091                 ccw_device_do_unbind_bind(cdev);
2092                 break;
2093         case CDEV_TODO_REGISTER:
2094                 io_subchannel_register(cdev);
2095                 break;
2096         case CDEV_TODO_UNREG_EVAL:
2097                 if (!sch_is_pseudo_sch(sch))
2098                         css_schedule_eval(sch->schid);
2099                 fallthrough;
2100         case CDEV_TODO_UNREG:
2101                 if (sch_is_pseudo_sch(sch))
2102                         ccw_device_unregister(cdev);
2103                 else
2104                         ccw_device_call_sch_unregister(cdev);
2105                 break;
2106         default:
2107                 break;
2108         }
2109         /* Release workqueue ref. */
2110         put_device(&cdev->dev);
2111 }
2112
2113 /**
2114  * ccw_device_sched_todo - schedule ccw device operation
2115  * @cdev: ccw device
2116  * @todo: todo
2117  *
2118  * Schedule the operation identified by @todo to be performed on the slow path
2119  * workqueue. Do nothing if another operation with higher priority is already
2120  * scheduled. Needs to be called with ccwdev lock held.
2121  */
2122 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2123 {
2124         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2125                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2126                       todo);
2127         if (cdev->private->todo >= todo)
2128                 return;
2129         cdev->private->todo = todo;
2130         /* Get workqueue ref. */
2131         if (!get_device(&cdev->dev))
2132                 return;
2133         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2134                 /* Already queued, release workqueue ref. */
2135                 put_device(&cdev->dev);
2136         }
2137 }
2138
2139 /**
2140  * ccw_device_siosl() - initiate logging
2141  * @cdev: ccw device
2142  *
2143  * This function is used to invoke model-dependent logging within the channel
2144  * subsystem.
2145  */
2146 int ccw_device_siosl(struct ccw_device *cdev)
2147 {
2148         struct subchannel *sch = to_subchannel(cdev->dev.parent);
2149
2150         return chsc_siosl(sch->schid);
2151 }
2152 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2153
2154 EXPORT_SYMBOL(ccw_device_set_online);
2155 EXPORT_SYMBOL(ccw_device_set_offline);
2156 EXPORT_SYMBOL(ccw_driver_register);
2157 EXPORT_SYMBOL(ccw_driver_unregister);
2158 EXPORT_SYMBOL(get_ccwdev_by_busid);