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 ([email protected])
   7  *               Cornelia Huck ([email protected])
   8  *               Martin Schwidefsky ([email protected])
   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_settle(void)
 153 {
 154         int ret;
 155
 156         ret = wait_event_interruptible(ccw_device_init_wq,
 157                                 atomic_read(&ccw_device_init_count) == 0);
 158         if (ret)
 159                 return -EINTR;
 160         flush_workqueue(cio_work_q);
 161         return 0;
 162 }
 163
 164 static struct css_driver io_subchannel_driver = {
 165         .drv = {
 166                 .owner = THIS_MODULE,
 167                 .name = "io_subchannel",
 168         },
 169         .subchannel_type = io_subchannel_ids,
 170         .irq = io_subchannel_irq,
 171         .sch_event = io_subchannel_sch_event,
 172         .chp_event = io_subchannel_chp_event,
 173         .probe = io_subchannel_probe,
 174         .remove = io_subchannel_remove,
 175         .shutdown = io_subchannel_shutdown,
 176         .settle = io_subchannel_settle,
 177 };
 178
 179 int __init io_subchannel_init(void)
 180 {
 181         int ret;
 182
 183         timer_setup(&recovery_timer, recovery_func, 0);
 184         ret = bus_register(&ccw_bus_type);
 185         if (ret)
 186                 return ret;
 187         ret = css_driver_register(&io_subchannel_driver);
 188         if (ret)
 189                 bus_unregister(&ccw_bus_type);
 190
 191         return ret;
 192 }
 193
 194
 195 /************************ device handling **************************/
 196
 197 static ssize_t
 198 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 199 {
 200         struct ccw_device *cdev = to_ccwdev(dev);
 201         struct ccw_device_id *id = &(cdev->id);
 202
 203         if (id->dev_type != 0)
 204                 return sprintf(buf, "%04x/%02x\n",
 205                                 id->dev_type, id->dev_model);
 206         else
 207                 return sprintf(buf, "n/a\n");
 208 }
 209
 210 static ssize_t
 211 cutype_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         return sprintf(buf, "%04x/%02x\n",
 217                        id->cu_type, id->cu_model);
 218 }
 219
 220 static ssize_t
 221 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 222 {
 223         struct ccw_device *cdev = to_ccwdev(dev);
 224         struct ccw_device_id *id = &(cdev->id);
 225         int len;
 226
 227         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 228
 229         return len > PAGE_SIZE ? PAGE_SIZE : len;
 230 }
 231
 232 static ssize_t
 233 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 234 {
 235         struct ccw_device *cdev = to_ccwdev(dev);
 236
 237         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 238 }
 239
 240 int ccw_device_is_orphan(struct ccw_device *cdev)
 241 {
 242         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 243 }
 244
 245 static void ccw_device_unregister(struct ccw_device *cdev)
 246 {
 247         if (device_is_registered(&cdev->dev)) {
 248                 /* Undo device_add(). */
 249                 device_del(&cdev->dev);
 250         }
 251         if (cdev->private->flags.initialized) {
 252                 cdev->private->flags.initialized = 0;
 253                 /* Release reference from device_initialize(). */
 254                 put_device(&cdev->dev);
 255         }
 256 }
 257
 258 static void io_subchannel_quiesce(struct subchannel *);
 259
 260 /**
 261  * ccw_device_set_offline() - disable a ccw device for I/O
 262  * @cdev: target ccw device
 263  *
 264  * This function calls the driver's set_offline() function for @cdev, if
 265  * given, and then disables @cdev.
 266  * Returns:
 267  *   %0 on success and a negative error value on failure.
 268  * Context:
 269  *  enabled, ccw device lock not held
 270  */
 271 int ccw_device_set_offline(struct ccw_device *cdev)
 272 {
 273         struct subchannel *sch;
 274         int ret, state;
 275
 276         if (!cdev)
 277                 return -ENODEV;
 278         if (!cdev->online || !cdev->drv)
 279                 return -EINVAL;
 280
 281         if (cdev->drv->set_offline) {
 282                 ret = cdev->drv->set_offline(cdev);
 283                 if (ret != 0)
 284                         return ret;
 285         }
 286         spin_lock_irq(cdev->ccwlock);
 287         sch = to_subchannel(cdev->dev.parent);
 288         cdev->online = 0;
 289         /* Wait until a final state or DISCONNECTED is reached */
 290         while (!dev_fsm_final_state(cdev) &&
 291                cdev->private->state != DEV_STATE_DISCONNECTED) {
 292                 spin_unlock_irq(cdev->ccwlock);
 293                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 294                            cdev->private->state == DEV_STATE_DISCONNECTED));
 295                 spin_lock_irq(cdev->ccwlock);
 296         }
 297         do {
 298                 ret = ccw_device_offline(cdev);
 299                 if (!ret)
 300                         break;
 301                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 302                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 303                               cdev->private->dev_id.devno);
 304                 if (ret != -EBUSY)
 305                         goto error;
 306                 state = cdev->private->state;
 307                 spin_unlock_irq(cdev->ccwlock);
 308                 io_subchannel_quiesce(sch);
 309                 spin_lock_irq(cdev->ccwlock);
 310                 cdev->private->state = state;
 311         } while (ret == -EBUSY);
 312         spin_unlock_irq(cdev->ccwlock);
 313         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 314                    cdev->private->state == DEV_STATE_DISCONNECTED));
 315         /* Inform the user if set offline failed. */
 316         if (cdev->private->state == DEV_STATE_BOXED) {
 317                 pr_warn("%s: The device entered boxed state while being set offline\n",
 318                         dev_name(&cdev->dev));
 319         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 320                 pr_warn("%s: The device stopped operating while being set offline\n",
 321                         dev_name(&cdev->dev));
 322         }
 323         /* Give up reference from ccw_device_set_online(). */
 324         put_device(&cdev->dev);
 325         return 0;
 326
 327 error:
 328         cdev->private->state = DEV_STATE_OFFLINE;
 329         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 330         spin_unlock_irq(cdev->ccwlock);
 331         /* Give up reference from ccw_device_set_online(). */
 332         put_device(&cdev->dev);
 333         return -ENODEV;
 334 }
 335
 336 /**
 337  * ccw_device_set_online() - enable a ccw device for I/O
 338  * @cdev: target ccw device
 339  *
 340  * This function first enables @cdev and then calls the driver's set_online()
 341  * function for @cdev, if given. If set_online() returns an error, @cdev is
 342  * disabled again.
 343  * Returns:
 344  *   %0 on success and a negative error value on failure.
 345  * Context:
 346  *  enabled, ccw device lock not held
 347  */
 348 int ccw_device_set_online(struct ccw_device *cdev)
 349 {
 350         int ret;
 351         int ret2;
 352
 353         if (!cdev)
 354                 return -ENODEV;
 355         if (cdev->online || !cdev->drv)
 356                 return -EINVAL;
 357         /* Hold on to an extra reference while device is online. */
 358         if (!get_device(&cdev->dev))
 359                 return -ENODEV;
 360
 361         spin_lock_irq(cdev->ccwlock);
 362         ret = ccw_device_online(cdev);
 363         spin_unlock_irq(cdev->ccwlock);
 364         if (ret == 0)
 365                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 366         else {
 367                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 368                               "device 0.%x.%04x\n",
 369                               ret, cdev->private->dev_id.ssid,
 370                               cdev->private->dev_id.devno);
 371                 /* Give up online reference since onlining failed. */
 372                 put_device(&cdev->dev);
 373                 return ret;
 374         }
 375         spin_lock_irq(cdev->ccwlock);
 376         /* Check if online processing was successful */
 377         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 378             (cdev->private->state != DEV_STATE_W4SENSE)) {
 379                 spin_unlock_irq(cdev->ccwlock);
 380                 /* Inform the user that set online failed. */
 381                 if (cdev->private->state == DEV_STATE_BOXED) {
 382                         pr_warn("%s: Setting the device online failed because it is boxed\n",
 383                                 dev_name(&cdev->dev));
 384                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 385                         pr_warn("%s: Setting the device online failed because it is not operational\n",
 386                                 dev_name(&cdev->dev));
 387                 }
 388                 /* Give up online reference since onlining failed. */
 389                 put_device(&cdev->dev);
 390                 return -ENODEV;
 391         }
 392         spin_unlock_irq(cdev->ccwlock);
 393         if (cdev->drv->set_online)
 394                 ret = cdev->drv->set_online(cdev);
 395         if (ret)
 396                 goto rollback;
 397
 398         spin_lock_irq(cdev->ccwlock);
 399         cdev->online = 1;
 400         spin_unlock_irq(cdev->ccwlock);
 401         return 0;
 402
 403 rollback:
 404         spin_lock_irq(cdev->ccwlock);
 405         /* Wait until a final state or DISCONNECTED is reached */
 406         while (!dev_fsm_final_state(cdev) &&
 407                cdev->private->state != DEV_STATE_DISCONNECTED) {
 408                 spin_unlock_irq(cdev->ccwlock);
 409                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 410                            cdev->private->state == DEV_STATE_DISCONNECTED));
 411                 spin_lock_irq(cdev->ccwlock);
 412         }
 413         ret2 = ccw_device_offline(cdev);
 414         if (ret2)
 415                 goto error;
 416         spin_unlock_irq(cdev->ccwlock);
 417         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 418                    cdev->private->state == DEV_STATE_DISCONNECTED));
 419         /* Give up online reference since onlining failed. */
 420         put_device(&cdev->dev);
 421         return ret;
 422
 423 error:
 424         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 425                       "device 0.%x.%04x\n",
 426                       ret2, cdev->private->dev_id.ssid,
 427                       cdev->private->dev_id.devno);
 428         cdev->private->state = DEV_STATE_OFFLINE;
 429         spin_unlock_irq(cdev->ccwlock);
 430         /* Give up online reference since onlining failed. */
 431         put_device(&cdev->dev);
 432         return ret;
 433 }
 434
 435 static int online_store_handle_offline(struct ccw_device *cdev)
 436 {
 437         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 438                 spin_lock_irq(cdev->ccwlock);
 439                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 440                 spin_unlock_irq(cdev->ccwlock);
 441                 return 0;
 442         }
 443         if (cdev->drv && cdev->drv->set_offline)
 444                 return ccw_device_set_offline(cdev);
 445         return -EINVAL;
 446 }
 447
 448 static int online_store_recog_and_online(struct ccw_device *cdev)
 449 {
 450         /* Do device recognition, if needed. */
 451         if (cdev->private->state == DEV_STATE_BOXED) {
 452                 spin_lock_irq(cdev->ccwlock);
 453                 ccw_device_recognition(cdev);
 454                 spin_unlock_irq(cdev->ccwlock);
 455                 wait_event(cdev->private->wait_q,
 456                            cdev->private->flags.recog_done);
 457                 if (cdev->private->state != DEV_STATE_OFFLINE)
 458                         /* recognition failed */
 459                         return -EAGAIN;
 460         }
 461         if (cdev->drv && cdev->drv->set_online)
 462                 return ccw_device_set_online(cdev);
 463         return -EINVAL;
 464 }
 465
 466 static int online_store_handle_online(struct ccw_device *cdev, int force)
 467 {
 468         int ret;
 469
 470         ret = online_store_recog_and_online(cdev);
 471         if (ret && !force)
 472                 return ret;
 473         if (force && cdev->private->state == DEV_STATE_BOXED) {
 474                 ret = ccw_device_stlck(cdev);
 475                 if (ret)
 476                         return ret;
 477                 if (cdev->id.cu_type == 0)
 478                         cdev->private->state = DEV_STATE_NOT_OPER;
 479                 ret = online_store_recog_and_online(cdev);
 480                 if (ret)
 481                         return ret;
 482         }
 483         return 0;
 484 }
 485
 486 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 487                              const char *buf, size_t count)
 488 {
 489         struct ccw_device *cdev = to_ccwdev(dev);
 490         int force, ret;
 491         unsigned long i;
 492
 493         /* Prevent conflict between multiple on-/offline processing requests. */
 494         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 495                 return -EAGAIN;
 496         /* Prevent conflict between internal I/Os and on-/offline processing. */
 497         if (!dev_fsm_final_state(cdev) &&
 498             cdev->private->state != DEV_STATE_DISCONNECTED) {
 499                 ret = -EAGAIN;
 500                 goto out;
 501         }
 502         /* Prevent conflict between pending work and on-/offline processing.*/
 503         if (work_pending(&cdev->private->todo_work)) {
 504                 ret = -EAGAIN;
 505                 goto out;
 506         }
 507         if (!strncmp(buf, "force\n", count)) {
 508                 force = 1;
 509                 i = 1;
 510                 ret = 0;
 511         } else {
 512                 force = 0;
 513                 ret = kstrtoul(buf, 16, &i);
 514         }
 515         if (ret)
 516                 goto out;
 517
 518         device_lock(dev);
 519         switch (i) {
 520         case 0:
 521                 ret = online_store_handle_offline(cdev);
 522                 break;
 523         case 1:
 524                 ret = online_store_handle_online(cdev, force);
 525                 break;
 526         default:
 527                 ret = -EINVAL;
 528         }
 529         device_unlock(dev);
 530
 531 out:
 532         atomic_set(&cdev->private->onoff, 0);
 533         return (ret < 0) ? ret : count;
 534 }
 535
 536 static ssize_t
 537 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 538 {
 539         struct ccw_device *cdev = to_ccwdev(dev);
 540         struct subchannel *sch;
 541
 542         if (ccw_device_is_orphan(cdev))
 543                 return sprintf(buf, "no device\n");
 544         switch (cdev->private->state) {
 545         case DEV_STATE_BOXED:
 546                 return sprintf(buf, "boxed\n");
 547         case DEV_STATE_DISCONNECTED:
 548         case DEV_STATE_DISCONNECTED_SENSE_ID:
 549         case DEV_STATE_NOT_OPER:
 550                 sch = to_subchannel(dev->parent);
 551                 if (!sch->lpm)
 552                         return sprintf(buf, "no path\n");
 553                 else
 554                         return sprintf(buf, "no device\n");
 555         default:
 556                 /* All other states considered fine. */
 557                 return sprintf(buf, "good\n");
 558         }
 559 }
 560
 561 static ssize_t
 562 initiate_logging(struct device *dev, struct device_attribute *attr,
 563                  const char *buf, size_t count)
 564 {
 565         struct subchannel *sch = to_subchannel(dev);
 566         int rc;
 567
 568         rc = chsc_siosl(sch->schid);
 569         if (rc < 0) {
 570                 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
 571                         sch->schid.ssid, sch->schid.sch_no, rc);
 572                 return rc;
 573         }
 574         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
 575                   sch->schid.ssid, sch->schid.sch_no);
 576         return count;
 577 }
 578
 579 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
 580                         char *buf)
 581 {
 582         struct subchannel *sch = to_subchannel(dev);
 583
 584         return sprintf(buf, "%02x\n", sch->vpm);
 585 }
 586
 587 static DEVICE_ATTR_RO(devtype);
 588 static DEVICE_ATTR_RO(cutype);
 589 static DEVICE_ATTR_RO(modalias);
 590 static DEVICE_ATTR_RW(online);
 591 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 592 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 593 static DEVICE_ATTR_RO(vpm);
 594
 595 static struct attribute *io_subchannel_attrs[] = {
 596         &dev_attr_logging.attr,
 597         &dev_attr_vpm.attr,
 598         NULL,
 599 };
 600
 601 static const struct attribute_group io_subchannel_attr_group = {
 602         .attrs = io_subchannel_attrs,
 603 };
 604
 605 static struct attribute * ccwdev_attrs[] = {
 606         &dev_attr_devtype.attr,
 607         &dev_attr_cutype.attr,
 608         &dev_attr_modalias.attr,
 609         &dev_attr_online.attr,
 610         &dev_attr_cmb_enable.attr,
 611         &dev_attr_availability.attr,
 612         NULL,
 613 };
 614
 615 static const struct attribute_group ccwdev_attr_group = {
 616         .attrs = ccwdev_attrs,
 617 };
 618
 619 static const struct attribute_group *ccwdev_attr_groups[] = {
 620         &ccwdev_attr_group,
 621         NULL,
 622 };
 623
 624 static int ccw_device_add(struct ccw_device *cdev)
 625 {
 626         struct device *dev = &cdev->dev;
 627
 628         dev->bus = &ccw_bus_type;
 629         return device_add(dev);
 630 }
 631
 632 static int match_dev_id(struct device *dev, const void *data)
 633 {
 634         struct ccw_device *cdev = to_ccwdev(dev);
 635         struct ccw_dev_id *dev_id = (void *)data;
 636
 637         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 638 }
 639
 640 /**
 641  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
 642  * @dev_id: id of the device to be searched
 643  *
 644  * This function searches all devices attached to the ccw bus for a device
 645  * matching @dev_id.
 646  * Returns:
 647  *  If a device is found its reference count is increased and returned;
 648  *  else %NULL is returned.
 649  */
 650 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 651 {
 652         struct device *dev;
 653
 654         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 655
 656         return dev ? to_ccwdev(dev) : NULL;
 657 }
 658 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
 659
 660 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 661 {
 662         int ret;
 663
 664         if (device_is_registered(&cdev->dev)) {
 665                 device_release_driver(&cdev->dev);
 666                 ret = device_attach(&cdev->dev);
 667                 WARN_ON(ret == -ENODEV);
 668         }
 669 }
 670
 671 static void
 672 ccw_device_release(struct device *dev)
 673 {
 674         struct ccw_device *cdev;
 675
 676         cdev = to_ccwdev(dev);
 677         cio_gp_dma_free(cdev->private->dma_pool, cdev->private->dma_area,
 678                         sizeof(*cdev->private->dma_area));
 679         cio_gp_dma_destroy(cdev->private->dma_pool, &cdev->dev);
 680         /* Release reference of parent subchannel. */
 681         put_device(cdev->dev.parent);
 682         kfree(cdev->private);
 683         kfree(cdev);
 684 }
 685
 686 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 687 {
 688         struct ccw_device *cdev;
 689         struct gen_pool *dma_pool;
 690
 691         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 692         if (!cdev)
 693                 goto err_cdev;
 694         cdev->private = kzalloc(sizeof(struct ccw_device_private),
 695                                 GFP_KERNEL | GFP_DMA);
 696         if (!cdev->private)
 697                 goto err_priv;
 698         cdev->dev.coherent_dma_mask = sch->dev.coherent_dma_mask;
 699         cdev->dev.dma_mask = sch->dev.dma_mask;
 700         dma_pool = cio_gp_dma_create(&cdev->dev, 1);
 701         if (!dma_pool)
 702                 goto err_dma_pool;
 703         cdev->private->dma_pool = dma_pool;
 704         cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
 705                                         sizeof(*cdev->private->dma_area));
 706         if (!cdev->private->dma_area)
 707                 goto err_dma_area;
 708         return cdev;
 709 err_dma_area:
 710         cio_gp_dma_destroy(dma_pool, &cdev->dev);
 711 err_dma_pool:
 712         kfree(cdev->private);
 713 err_priv:
 714         kfree(cdev);
 715 err_cdev:
 716         return ERR_PTR(-ENOMEM);
 717 }
 718
 719 static void ccw_device_todo(struct work_struct *work);
 720
 721 static int io_subchannel_initialize_dev(struct subchannel *sch,
 722                                         struct ccw_device *cdev)
 723 {
 724         struct ccw_device_private *priv = cdev->private;
 725         int ret;
 726
 727         priv->cdev = cdev;
 728         priv->int_class = IRQIO_CIO;
 729         priv->state = DEV_STATE_NOT_OPER;
 730         priv->dev_id.devno = sch->schib.pmcw.dev;
 731         priv->dev_id.ssid = sch->schid.ssid;
 732
 733         INIT_WORK(&priv->todo_work, ccw_device_todo);
 734         INIT_LIST_HEAD(&priv->cmb_list);
 735         init_waitqueue_head(&priv->wait_q);
 736         timer_setup(&priv->timer, ccw_device_timeout, 0);
 737
 738         atomic_set(&priv->onoff, 0);
 739         cdev->ccwlock = sch->lock;
 740         cdev->dev.parent = &sch->dev;
 741         cdev->dev.release = ccw_device_release;
 742         cdev->dev.groups = ccwdev_attr_groups;
 743         /* Do first half of device_register. */
 744         device_initialize(&cdev->dev);
 745         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 746                            cdev->private->dev_id.devno);
 747         if (ret)
 748                 goto out_put;
 749         if (!get_device(&sch->dev)) {
 750                 ret = -ENODEV;
 751                 goto out_put;
 752         }
 753         priv->flags.initialized = 1;
 754         spin_lock_irq(sch->lock);
 755         sch_set_cdev(sch, cdev);
 756         spin_unlock_irq(sch->lock);
 757         return 0;
 758
 759 out_put:
 760         /* Release reference from device_initialize(). */
 761         put_device(&cdev->dev);
 762         return ret;
 763 }
 764
 765 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 766 {
 767         struct ccw_device *cdev;
 768         int ret;
 769
 770         cdev = io_subchannel_allocate_dev(sch);
 771         if (!IS_ERR(cdev)) {
 772                 ret = io_subchannel_initialize_dev(sch, cdev);
 773                 if (ret)
 774                         cdev = ERR_PTR(ret);
 775         }
 776         return cdev;
 777 }
 778
 779 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 780
 781 static void sch_create_and_recog_new_device(struct subchannel *sch)
 782 {
 783         struct ccw_device *cdev;
 784
 785         /* Need to allocate a new ccw device. */
 786         cdev = io_subchannel_create_ccwdev(sch);
 787         if (IS_ERR(cdev)) {
 788                 /* OK, we did everything we could... */
 789                 css_sch_device_unregister(sch);
 790                 return;
 791         }
 792         /* Start recognition for the new ccw device. */
 793         io_subchannel_recog(cdev, sch);
 794 }
 795
 796 /*
 797  * Register recognized device.
 798  */
 799 static void io_subchannel_register(struct ccw_device *cdev)
 800 {
 801         struct subchannel *sch;
 802         int ret, adjust_init_count = 1;
 803         unsigned long flags;
 804
 805         sch = to_subchannel(cdev->dev.parent);
 806         /*
 807          * Check if subchannel is still registered. It may have become
 808          * unregistered if a machine check hit us after finishing
 809          * device recognition but before the register work could be
 810          * queued.
 811          */
 812         if (!device_is_registered(&sch->dev))
 813                 goto out_err;
 814         css_update_ssd_info(sch);
 815         /*
 816          * io_subchannel_register() will also be called after device
 817          * recognition has been done for a boxed device (which will already
 818          * be registered). We need to reprobe since we may now have sense id
 819          * information.
 820          */
 821         if (device_is_registered(&cdev->dev)) {
 822                 if (!cdev->drv) {
 823                         ret = device_reprobe(&cdev->dev);
 824                         if (ret)
 825                                 /* We can't do much here. */
 826                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 827                                               " %d for 0.%x.%04x\n", ret,
 828                                               cdev->private->dev_id.ssid,
 829                                               cdev->private->dev_id.devno);
 830                 }
 831                 adjust_init_count = 0;
 832                 goto out;
 833         }
 834         /*
 835          * Now we know this subchannel will stay, we can throw
 836          * our delayed uevent.
 837          */
 838         if (dev_get_uevent_suppress(&sch->dev)) {
 839                 dev_set_uevent_suppress(&sch->dev, 0);
 840                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 841         }
 842         /* make it known to the system */
 843         ret = ccw_device_add(cdev);
 844         if (ret) {
 845                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 846                               cdev->private->dev_id.ssid,
 847                               cdev->private->dev_id.devno, ret);
 848                 spin_lock_irqsave(sch->lock, flags);
 849                 sch_set_cdev(sch, NULL);
 850                 spin_unlock_irqrestore(sch->lock, flags);
 851                 /* Release initial device reference. */
 852                 put_device(&cdev->dev);
 853                 goto out_err;
 854         }
 855 out:
 856         cdev->private->flags.recog_done = 1;
 857         wake_up(&cdev->private->wait_q);
 858 out_err:
 859         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 860                 wake_up(&ccw_device_init_wq);
 861 }
 862
 863 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 864 {
 865         struct subchannel *sch;
 866
 867         /* Get subchannel reference for local processing. */
 868         if (!get_device(cdev->dev.parent))
 869                 return;
 870         sch = to_subchannel(cdev->dev.parent);
 871         css_sch_device_unregister(sch);
 872         /* Release subchannel reference for local processing. */
 873         put_device(&sch->dev);
 874 }
 875
 876 /*
 877  * subchannel recognition done. Called from the state machine.
 878  */
 879 void
 880 io_subchannel_recog_done(struct ccw_device *cdev)
 881 {
 882         if (css_init_done == 0) {
 883                 cdev->private->flags.recog_done = 1;
 884                 return;
 885         }
 886         switch (cdev->private->state) {
 887         case DEV_STATE_BOXED:
 888                 /* Device did not respond in time. */
 889         case DEV_STATE_NOT_OPER:
 890                 cdev->private->flags.recog_done = 1;
 891                 /* Remove device found not operational. */
 892                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 893                 if (atomic_dec_and_test(&ccw_device_init_count))
 894                         wake_up(&ccw_device_init_wq);
 895                 break;
 896         case DEV_STATE_OFFLINE:
 897                 /*
 898                  * We can't register the device in interrupt context so
 899                  * we schedule a work item.
 900                  */
 901                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 902                 break;
 903         }
 904 }
 905
 906 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 907 {
 908         /* Increase counter of devices currently in recognition. */
 909         atomic_inc(&ccw_device_init_count);
 910
 911         /* Start async. device sensing. */
 912         spin_lock_irq(sch->lock);
 913         ccw_device_recognition(cdev);
 914         spin_unlock_irq(sch->lock);
 915 }
 916
 917 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 918                                   struct subchannel *sch)
 919 {
 920         struct subchannel *old_sch;
 921         int rc, old_enabled = 0;
 922
 923         old_sch = to_subchannel(cdev->dev.parent);
 924         /* Obtain child reference for new parent. */
 925         if (!get_device(&sch->dev))
 926                 return -ENODEV;
 927
 928         if (!sch_is_pseudo_sch(old_sch)) {
 929                 spin_lock_irq(old_sch->lock);
 930                 old_enabled = old_sch->schib.pmcw.ena;
 931                 rc = 0;
 932                 if (old_enabled)
 933                         rc = cio_disable_subchannel(old_sch);
 934                 spin_unlock_irq(old_sch->lock);
 935                 if (rc == -EBUSY) {
 936                         /* Release child reference for new parent. */
 937                         put_device(&sch->dev);
 938                         return rc;
 939                 }
 940         }
 941
 942         mutex_lock(&sch->reg_mutex);
 943         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 944         mutex_unlock(&sch->reg_mutex);
 945         if (rc) {
 946                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 947                               cdev->private->dev_id.ssid,
 948                               cdev->private->dev_id.devno, sch->schid.ssid,
 949                               sch->schib.pmcw.dev, rc);
 950                 if (old_enabled) {
 951                         /* Try to reenable the old subchannel. */
 952                         spin_lock_irq(old_sch->lock);
 953                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 954                         spin_unlock_irq(old_sch->lock);
 955                 }
 956                 /* Release child reference for new parent. */
 957                 put_device(&sch->dev);
 958                 return rc;
 959         }
 960         /* Clean up old subchannel. */
 961         if (!sch_is_pseudo_sch(old_sch)) {
 962                 spin_lock_irq(old_sch->lock);
 963                 sch_set_cdev(old_sch, NULL);
 964                 spin_unlock_irq(old_sch->lock);
 965                 css_schedule_eval(old_sch->schid);
 966         }
 967         /* Release child reference for old parent. */
 968         put_device(&old_sch->dev);
 969         /* Initialize new subchannel. */
 970         spin_lock_irq(sch->lock);
 971         cdev->ccwlock = sch->lock;
 972         if (!sch_is_pseudo_sch(sch))
 973                 sch_set_cdev(sch, cdev);
 974         spin_unlock_irq(sch->lock);
 975         if (!sch_is_pseudo_sch(sch))
 976                 css_update_ssd_info(sch);
 977         return 0;
 978 }
 979
 980 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 981 {
 982         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 983         struct channel_subsystem *css = to_css(sch->dev.parent);
 984
 985         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 986 }
 987
 988 static void io_subchannel_irq(struct subchannel *sch)
 989 {
 990         struct ccw_device *cdev;
 991
 992         cdev = sch_get_cdev(sch);
 993
 994         CIO_TRACE_EVENT(6, "IRQ");
 995         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
 996         if (cdev)
 997                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
 998         else
 999                 inc_irq_stat(IRQIO_CIO);
1000 }
1001
1002 void io_subchannel_init_config(struct subchannel *sch)
1003 {
1004         memset(&sch->config, 0, sizeof(sch->config));
1005         sch->config.csense = 1;
1006 }
1007
1008 static void io_subchannel_init_fields(struct subchannel *sch)
1009 {
1010         if (cio_is_console(sch->schid))
1011                 sch->opm = 0xff;
1012         else
1013                 sch->opm = chp_get_sch_opm(sch);
1014         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1015         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1016
1017         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1018                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1019                       sch->schib.pmcw.dev, sch->schid.ssid,
1020                       sch->schid.sch_no, sch->schib.pmcw.pim,
1021                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1022
1023         io_subchannel_init_config(sch);
1024 }
1025
1026 /*
1027  * Note: We always return 0 so that we bind to the device even on error.
1028  * This is needed so that our remove function is called on unregister.
1029  */
1030 static int io_subchannel_probe(struct subchannel *sch)
1031 {
1032         struct io_subchannel_private *io_priv;
1033         struct ccw_device *cdev;
1034         int rc;
1035
1036         if (cio_is_console(sch->schid)) {
1037                 rc = sysfs_create_group(&sch->dev.kobj,
1038                                         &io_subchannel_attr_group);
1039                 if (rc)
1040                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1041                                       "attributes for subchannel "
1042                                       "0.%x.%04x (rc=%d)\n",
1043                                       sch->schid.ssid, sch->schid.sch_no, rc);
1044                 /*
1045                  * The console subchannel already has an associated ccw_device.
1046                  * Throw the delayed uevent for the subchannel, register
1047                  * the ccw_device and exit.
1048                  */
1049                 if (dev_get_uevent_suppress(&sch->dev)) {
1050                         /* should always be the case for the console */
1051                         dev_set_uevent_suppress(&sch->dev, 0);
1052                         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1053                 }
1054                 cdev = sch_get_cdev(sch);
1055                 rc = ccw_device_add(cdev);
1056                 if (rc) {
1057                         /* Release online reference. */
1058                         put_device(&cdev->dev);
1059                         goto out_schedule;
1060                 }
1061                 if (atomic_dec_and_test(&ccw_device_init_count))
1062                         wake_up(&ccw_device_init_wq);
1063                 return 0;
1064         }
1065         io_subchannel_init_fields(sch);
1066         rc = cio_commit_config(sch);
1067         if (rc)
1068                 goto out_schedule;
1069         rc = sysfs_create_group(&sch->dev.kobj,
1070                                 &io_subchannel_attr_group);
1071         if (rc)
1072                 goto out_schedule;
1073         /* Allocate I/O subchannel private data. */
1074         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1075         if (!io_priv)
1076                 goto out_schedule;
1077
1078         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1079                                 sizeof(*io_priv->dma_area),
1080                                 &io_priv->dma_area_dma, GFP_KERNEL);
1081         if (!io_priv->dma_area) {
1082                 kfree(io_priv);
1083                 goto out_schedule;
1084         }
1085
1086         set_io_private(sch, io_priv);
1087         css_schedule_eval(sch->schid);
1088         return 0;
1089
1090 out_schedule:
1091         spin_lock_irq(sch->lock);
1092         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1093         spin_unlock_irq(sch->lock);
1094         return 0;
1095 }
1096
1097 static int io_subchannel_remove(struct subchannel *sch)
1098 {
1099         struct io_subchannel_private *io_priv = to_io_private(sch);
1100         struct ccw_device *cdev;
1101
1102         cdev = sch_get_cdev(sch);
1103         if (!cdev)
1104                 goto out_free;
1105
1106         ccw_device_unregister(cdev);
1107         spin_lock_irq(sch->lock);
1108         sch_set_cdev(sch, NULL);
1109         set_io_private(sch, NULL);
1110         spin_unlock_irq(sch->lock);
1111 out_free:
1112         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1113                           io_priv->dma_area, io_priv->dma_area_dma);
1114         kfree(io_priv);
1115         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1116         return 0;
1117 }
1118
1119 static void io_subchannel_verify(struct subchannel *sch)
1120 {
1121         struct ccw_device *cdev;
1122
1123         cdev = sch_get_cdev(sch);
1124         if (cdev)
1125                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1126 }
1127
1128 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1129 {
1130         struct ccw_device *cdev;
1131
1132         cdev = sch_get_cdev(sch);
1133         if (!cdev)
1134                 return;
1135         if (cio_update_schib(sch))
1136                 goto err;
1137         /* Check for I/O on path. */
1138         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1139                 goto out;
1140         if (cdev->private->state == DEV_STATE_ONLINE) {
1141                 ccw_device_kill_io(cdev);
1142                 goto out;
1143         }
1144         if (cio_clear(sch))
1145                 goto err;
1146 out:
1147         /* Trigger path verification. */
1148         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1149         return;
1150
1151 err:
1152         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1153 }
1154
1155 static int io_subchannel_chp_event(struct subchannel *sch,
1156                                    struct chp_link *link, int event)
1157 {
1158         struct ccw_device *cdev = sch_get_cdev(sch);
1159         int mask, chpid, valid_bit;
1160         int path_event[8];
1161
1162         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1163         if (!mask)
1164                 return 0;
1165         switch (event) {
1166         case CHP_VARY_OFF:
1167                 sch->opm &= ~mask;
1168                 sch->lpm &= ~mask;
1169                 if (cdev)
1170                         cdev->private->path_gone_mask |= mask;
1171                 io_subchannel_terminate_path(sch, mask);
1172                 break;
1173         case CHP_VARY_ON:
1174                 sch->opm |= mask;
1175                 sch->lpm |= mask;
1176                 if (cdev)
1177                         cdev->private->path_new_mask |= mask;
1178                 io_subchannel_verify(sch);
1179                 break;
1180         case CHP_OFFLINE:
1181                 if (cio_update_schib(sch))
1182                         return -ENODEV;
1183                 if (cdev)
1184                         cdev->private->path_gone_mask |= mask;
1185                 io_subchannel_terminate_path(sch, mask);
1186                 break;
1187         case CHP_ONLINE:
1188                 if (cio_update_schib(sch))
1189                         return -ENODEV;
1190                 sch->lpm |= mask & sch->opm;
1191                 if (cdev)
1192                         cdev->private->path_new_mask |= mask;
1193                 io_subchannel_verify(sch);
1194                 break;
1195         case CHP_FCES_EVENT:
1196                 /* Forward Endpoint Security event */
1197                 for (chpid = 0, valid_bit = 0x80; chpid < 8; chpid++,
1198                                 valid_bit >>= 1) {
1199                         if (mask & valid_bit)
1200                                 path_event[chpid] = PE_PATH_FCES_EVENT;
1201                         else
1202                                 path_event[chpid] = PE_NONE;
1203                 }
1204                 if (cdev)
1205                         cdev->drv->path_event(cdev, path_event);
1206                 break;
1207         }
1208         return 0;
1209 }
1210
1211 static void io_subchannel_quiesce(struct subchannel *sch)
1212 {
1213         struct ccw_device *cdev;
1214         int ret;
1215
1216         spin_lock_irq(sch->lock);
1217         cdev = sch_get_cdev(sch);
1218         if (cio_is_console(sch->schid))
1219                 goto out_unlock;
1220         if (!sch->schib.pmcw.ena)
1221                 goto out_unlock;
1222         ret = cio_disable_subchannel(sch);
1223         if (ret != -EBUSY)
1224                 goto out_unlock;
1225         if (cdev->handler)
1226                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1227         while (ret == -EBUSY) {
1228                 cdev->private->state = DEV_STATE_QUIESCE;
1229                 cdev->private->iretry = 255;
1230                 ret = ccw_device_cancel_halt_clear(cdev);
1231                 if (ret == -EBUSY) {
1232                         ccw_device_set_timeout(cdev, HZ/10);
1233                         spin_unlock_irq(sch->lock);
1234                         wait_event(cdev->private->wait_q,
1235                                    cdev->private->state != DEV_STATE_QUIESCE);
1236                         spin_lock_irq(sch->lock);
1237                 }
1238                 ret = cio_disable_subchannel(sch);
1239         }
1240 out_unlock:
1241         spin_unlock_irq(sch->lock);
1242 }
1243
1244 static void io_subchannel_shutdown(struct subchannel *sch)
1245 {
1246         io_subchannel_quiesce(sch);
1247 }
1248
1249 static int device_is_disconnected(struct ccw_device *cdev)
1250 {
1251         if (!cdev)
1252                 return 0;
1253         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1254                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1255 }
1256
1257 static int recovery_check(struct device *dev, void *data)
1258 {
1259         struct ccw_device *cdev = to_ccwdev(dev);
1260         struct subchannel *sch;
1261         int *redo = data;
1262
1263         spin_lock_irq(cdev->ccwlock);
1264         switch (cdev->private->state) {
1265         case DEV_STATE_ONLINE:
1266                 sch = to_subchannel(cdev->dev.parent);
1267                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1268                         break;
1269                 fallthrough;
1270         case DEV_STATE_DISCONNECTED:
1271                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1272                               cdev->private->dev_id.ssid,
1273                               cdev->private->dev_id.devno);
1274                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1275                 *redo = 1;
1276                 break;
1277         case DEV_STATE_DISCONNECTED_SENSE_ID:
1278                 *redo = 1;
1279                 break;
1280         }
1281         spin_unlock_irq(cdev->ccwlock);
1282
1283         return 0;
1284 }
1285
1286 static void recovery_work_func(struct work_struct *unused)
1287 {
1288         int redo = 0;
1289
1290         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1291         if (redo) {
1292                 spin_lock_irq(&recovery_lock);
1293                 if (!timer_pending(&recovery_timer)) {
1294                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1295                                 recovery_phase++;
1296                         mod_timer(&recovery_timer, jiffies +
1297                                   recovery_delay[recovery_phase] * HZ);
1298                 }
1299                 spin_unlock_irq(&recovery_lock);
1300         } else
1301                 CIO_MSG_EVENT(3, "recovery: end\n");
1302 }
1303
1304 static DECLARE_WORK(recovery_work, recovery_work_func);
1305
1306 static void recovery_func(struct timer_list *unused)
1307 {
1308         /*
1309          * We can't do our recovery in softirq context and it's not
1310          * performance critical, so we schedule it.
1311          */
1312         schedule_work(&recovery_work);
1313 }
1314
1315 void ccw_device_schedule_recovery(void)
1316 {
1317         unsigned long flags;
1318
1319         CIO_MSG_EVENT(3, "recovery: schedule\n");
1320         spin_lock_irqsave(&recovery_lock, flags);
1321         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1322                 recovery_phase = 0;
1323                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1324         }
1325         spin_unlock_irqrestore(&recovery_lock, flags);
1326 }
1327
1328 static int purge_fn(struct device *dev, void *data)
1329 {
1330         struct ccw_device *cdev = to_ccwdev(dev);
1331         struct ccw_dev_id *id = &cdev->private->dev_id;
1332
1333         spin_lock_irq(cdev->ccwlock);
1334         if (is_blacklisted(id->ssid, id->devno) &&
1335             (cdev->private->state == DEV_STATE_OFFLINE) &&
1336             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1337                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1338                               id->devno);
1339                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1340                 atomic_set(&cdev->private->onoff, 0);
1341         }
1342         spin_unlock_irq(cdev->ccwlock);
1343         /* Abort loop in case of pending signal. */
1344         if (signal_pending(current))
1345                 return -EINTR;
1346
1347         return 0;
1348 }
1349
1350 /**
1351  * ccw_purge_blacklisted - purge unused, blacklisted devices
1352  *
1353  * Unregister all ccw devices that are offline and on the blacklist.
1354  */
1355 int ccw_purge_blacklisted(void)
1356 {
1357         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1358         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1359         return 0;
1360 }
1361
1362 void ccw_device_set_disconnected(struct ccw_device *cdev)
1363 {
1364         if (!cdev)
1365                 return;
1366         ccw_device_set_timeout(cdev, 0);
1367         cdev->private->flags.fake_irb = 0;
1368         cdev->private->state = DEV_STATE_DISCONNECTED;
1369         if (cdev->online)
1370                 ccw_device_schedule_recovery();
1371 }
1372
1373 void ccw_device_set_notoper(struct ccw_device *cdev)
1374 {
1375         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1376
1377         CIO_TRACE_EVENT(2, "notoper");
1378         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1379         ccw_device_set_timeout(cdev, 0);
1380         cio_disable_subchannel(sch);
1381         cdev->private->state = DEV_STATE_NOT_OPER;
1382 }
1383
1384 enum io_sch_action {
1385         IO_SCH_UNREG,
1386         IO_SCH_ORPH_UNREG,
1387         IO_SCH_ATTACH,
1388         IO_SCH_UNREG_ATTACH,
1389         IO_SCH_ORPH_ATTACH,
1390         IO_SCH_REPROBE,
1391         IO_SCH_VERIFY,
1392         IO_SCH_DISC,
1393         IO_SCH_NOP,
1394 };
1395
1396 static enum io_sch_action sch_get_action(struct subchannel *sch)
1397 {
1398         struct ccw_device *cdev;
1399
1400         cdev = sch_get_cdev(sch);
1401         if (cio_update_schib(sch)) {
1402                 /* Not operational. */
1403                 if (!cdev)
1404                         return IO_SCH_UNREG;
1405                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1406                         return IO_SCH_UNREG;
1407                 return IO_SCH_ORPH_UNREG;
1408         }
1409         /* Operational. */
1410         if (!cdev)
1411                 return IO_SCH_ATTACH;
1412         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1413                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1414                         return IO_SCH_UNREG_ATTACH;
1415                 return IO_SCH_ORPH_ATTACH;
1416         }
1417         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1418                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1419                         return IO_SCH_UNREG;
1420                 return IO_SCH_DISC;
1421         }
1422         if (device_is_disconnected(cdev))
1423                 return IO_SCH_REPROBE;
1424         if (cdev->online)
1425                 return IO_SCH_VERIFY;
1426         if (cdev->private->state == DEV_STATE_NOT_OPER)
1427                 return IO_SCH_UNREG_ATTACH;
1428         return IO_SCH_NOP;
1429 }
1430
1431 /**
1432  * io_subchannel_sch_event - process subchannel event
1433  * @sch: subchannel
1434  * @process: non-zero if function is called in process context
1435  *
1436  * An unspecified event occurred for this subchannel. Adjust data according
1437  * to the current operational state of the subchannel and device. Return
1438  * zero when the event has been handled sufficiently or -EAGAIN when this
1439  * function should be called again in process context.
1440  */
1441 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1442 {
1443         unsigned long flags;
1444         struct ccw_device *cdev;
1445         struct ccw_dev_id dev_id;
1446         enum io_sch_action action;
1447         int rc = -EAGAIN;
1448
1449         spin_lock_irqsave(sch->lock, flags);
1450         if (!device_is_registered(&sch->dev))
1451                 goto out_unlock;
1452         if (work_pending(&sch->todo_work))
1453                 goto out_unlock;
1454         cdev = sch_get_cdev(sch);
1455         if (cdev && work_pending(&cdev->private->todo_work))
1456                 goto out_unlock;
1457         action = sch_get_action(sch);
1458         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1459                       sch->schid.ssid, sch->schid.sch_no, process,
1460                       action);
1461         /* Perform immediate actions while holding the lock. */
1462         switch (action) {
1463         case IO_SCH_REPROBE:
1464                 /* Trigger device recognition. */
1465                 ccw_device_trigger_reprobe(cdev);
1466                 rc = 0;
1467                 goto out_unlock;
1468         case IO_SCH_VERIFY:
1469                 /* Trigger path verification. */
1470                 io_subchannel_verify(sch);
1471                 rc = 0;
1472                 goto out_unlock;
1473         case IO_SCH_DISC:
1474                 ccw_device_set_disconnected(cdev);
1475                 rc = 0;
1476                 goto out_unlock;
1477         case IO_SCH_ORPH_UNREG:
1478         case IO_SCH_ORPH_ATTACH:
1479                 ccw_device_set_disconnected(cdev);
1480                 break;
1481         case IO_SCH_UNREG_ATTACH:
1482         case IO_SCH_UNREG:
1483                 if (!cdev)
1484                         break;
1485                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1486                         /*
1487                          * Note: delayed work triggered by this event
1488                          * and repeated calls to sch_event are synchronized
1489                          * by the above check for work_pending(cdev).
1490                          */
1491                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1492                 } else
1493                         ccw_device_set_notoper(cdev);
1494                 break;
1495         case IO_SCH_NOP:
1496                 rc = 0;
1497                 goto out_unlock;
1498         default:
1499                 break;
1500         }
1501         spin_unlock_irqrestore(sch->lock, flags);
1502         /* All other actions require process context. */
1503         if (!process)
1504                 goto out;
1505         /* Handle attached ccw device. */
1506         switch (action) {
1507         case IO_SCH_ORPH_UNREG:
1508         case IO_SCH_ORPH_ATTACH:
1509                 /* Move ccw device to orphanage. */
1510                 rc = ccw_device_move_to_orph(cdev);
1511                 if (rc)
1512                         goto out;
1513                 break;
1514         case IO_SCH_UNREG_ATTACH:
1515                 spin_lock_irqsave(sch->lock, flags);
1516                 sch_set_cdev(sch, NULL);
1517                 spin_unlock_irqrestore(sch->lock, flags);
1518                 /* Unregister ccw device. */
1519                 ccw_device_unregister(cdev);
1520                 break;
1521         default:
1522                 break;
1523         }
1524         /* Handle subchannel. */
1525         switch (action) {
1526         case IO_SCH_ORPH_UNREG:
1527         case IO_SCH_UNREG:
1528                 if (!cdev)
1529                         css_sch_device_unregister(sch);
1530                 break;
1531         case IO_SCH_ORPH_ATTACH:
1532         case IO_SCH_UNREG_ATTACH:
1533         case IO_SCH_ATTACH:
1534                 dev_id.ssid = sch->schid.ssid;
1535                 dev_id.devno = sch->schib.pmcw.dev;
1536                 cdev = get_ccwdev_by_dev_id(&dev_id);
1537                 if (!cdev) {
1538                         sch_create_and_recog_new_device(sch);
1539                         break;
1540                 }
1541                 rc = ccw_device_move_to_sch(cdev, sch);
1542                 if (rc) {
1543                         /* Release reference from get_ccwdev_by_dev_id() */
1544                         put_device(&cdev->dev);
1545                         goto out;
1546                 }
1547                 spin_lock_irqsave(sch->lock, flags);
1548                 ccw_device_trigger_reprobe(cdev);
1549                 spin_unlock_irqrestore(sch->lock, flags);
1550                 /* Release reference from get_ccwdev_by_dev_id() */
1551                 put_device(&cdev->dev);
1552                 break;
1553         default:
1554                 break;
1555         }
1556         return 0;
1557
1558 out_unlock:
1559         spin_unlock_irqrestore(sch->lock, flags);
1560 out:
1561         return rc;
1562 }
1563
1564 static void ccw_device_set_int_class(struct ccw_device *cdev)
1565 {
1566         struct ccw_driver *cdrv = cdev->drv;
1567
1568         /* Note: we interpret class 0 in this context as an uninitialized
1569          * field since it translates to a non-I/O interrupt class. */
1570         if (cdrv->int_class != 0)
1571                 cdev->private->int_class = cdrv->int_class;
1572         else
1573                 cdev->private->int_class = IRQIO_CIO;
1574 }
1575
1576 #ifdef CONFIG_CCW_CONSOLE
1577 int __init ccw_device_enable_console(struct ccw_device *cdev)
1578 {
1579         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1580         int rc;
1581
1582         if (!cdev->drv || !cdev->handler)
1583                 return -EINVAL;
1584
1585         io_subchannel_init_fields(sch);
1586         rc = cio_commit_config(sch);
1587         if (rc)
1588                 return rc;
1589         sch->driver = &io_subchannel_driver;
1590         io_subchannel_recog(cdev, sch);
1591         /* Now wait for the async. recognition to come to an end. */
1592         spin_lock_irq(cdev->ccwlock);
1593         while (!dev_fsm_final_state(cdev))
1594                 ccw_device_wait_idle(cdev);
1595
1596         /* Hold on to an extra reference while device is online. */
1597         get_device(&cdev->dev);
1598         rc = ccw_device_online(cdev);
1599         if (rc)
1600                 goto out_unlock;
1601
1602         while (!dev_fsm_final_state(cdev))
1603                 ccw_device_wait_idle(cdev);
1604
1605         if (cdev->private->state == DEV_STATE_ONLINE)
1606                 cdev->online = 1;
1607         else
1608                 rc = -EIO;
1609 out_unlock:
1610         spin_unlock_irq(cdev->ccwlock);
1611         if (rc) /* Give up online reference since onlining failed. */
1612                 put_device(&cdev->dev);
1613         return rc;
1614 }
1615
1616 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1617 {
1618         struct io_subchannel_private *io_priv;
1619         struct ccw_device *cdev;
1620         struct subchannel *sch;
1621
1622         sch = cio_probe_console();
1623         if (IS_ERR(sch))
1624                 return ERR_CAST(sch);
1625
1626         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1627         if (!io_priv)
1628                 goto err_priv;
1629         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1630                                 sizeof(*io_priv->dma_area),
1631                                 &io_priv->dma_area_dma, GFP_KERNEL);
1632         if (!io_priv->dma_area)
1633                 goto err_dma_area;
1634         set_io_private(sch, io_priv);
1635         cdev = io_subchannel_create_ccwdev(sch);
1636         if (IS_ERR(cdev)) {
1637                 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1638                                   io_priv->dma_area, io_priv->dma_area_dma);
1639                 set_io_private(sch, NULL);
1640                 put_device(&sch->dev);
1641                 kfree(io_priv);
1642                 return cdev;
1643         }
1644         cdev->drv = drv;
1645         ccw_device_set_int_class(cdev);
1646         return cdev;
1647
1648 err_dma_area:
1649         kfree(io_priv);
1650 err_priv:
1651         put_device(&sch->dev);
1652         return ERR_PTR(-ENOMEM);
1653 }
1654
1655 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1656 {
1657         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1658         struct io_subchannel_private *io_priv = to_io_private(sch);
1659
1660         set_io_private(sch, NULL);
1661         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1662                           io_priv->dma_area, io_priv->dma_area_dma);
1663         put_device(&sch->dev);
1664         put_device(&cdev->dev);
1665         kfree(io_priv);
1666 }
1667
1668 /**
1669  * ccw_device_wait_idle() - busy wait for device to become idle
1670  * @cdev: ccw device
1671  *
1672  * Poll until activity control is zero, that is, no function or data
1673  * transfer is pending/active.
1674  * Called with device lock being held.
1675  */
1676 void ccw_device_wait_idle(struct ccw_device *cdev)
1677 {
1678         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1679
1680         while (1) {
1681                 cio_tsch(sch);
1682                 if (sch->schib.scsw.cmd.actl == 0)
1683                         break;
1684                 udelay(100);
1685         }
1686 }
1687 #endif
1688
1689 /**
1690  * get_ccwdev_by_busid() - obtain device from a bus id
1691  * @cdrv: driver the device is owned by
1692  * @bus_id: bus id of the device to be searched
1693  *
1694  * This function searches all devices owned by @cdrv for a device with a bus
1695  * id matching @bus_id.
1696  * Returns:
1697  *  If a match is found, its reference count of the found device is increased
1698  *  and it is returned; else %NULL is returned.
1699  */
1700 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1701                                        const char *bus_id)
1702 {
1703         struct device *dev;
1704
1705         dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1706
1707         return dev ? to_ccwdev(dev) : NULL;
1708 }
1709
1710 /************************** device driver handling ************************/
1711
1712 /* This is the implementation of the ccw_driver class. The probe, remove
1713  * and release methods are initially very similar to the device_driver
1714  * implementations, with the difference that they have ccw_device
1715  * arguments.
1716  *
1717  * A ccw driver also contains the information that is needed for
1718  * device matching.
1719  */
1720 static int
1721 ccw_device_probe (struct device *dev)
1722 {
1723         struct ccw_device *cdev = to_ccwdev(dev);
1724         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1725         int ret;
1726
1727         cdev->drv = cdrv; /* to let the driver call _set_online */
1728         ccw_device_set_int_class(cdev);
1729         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1730         if (ret) {
1731                 cdev->drv = NULL;
1732                 cdev->private->int_class = IRQIO_CIO;
1733                 return ret;
1734         }
1735
1736         return 0;
1737 }
1738
1739 static int ccw_device_remove(struct device *dev)
1740 {
1741         struct ccw_device *cdev = to_ccwdev(dev);
1742         struct ccw_driver *cdrv = cdev->drv;
1743         struct subchannel *sch;
1744         int ret;
1745
1746         if (cdrv->remove)
1747                 cdrv->remove(cdev);
1748
1749         spin_lock_irq(cdev->ccwlock);
1750         if (cdev->online) {
1751                 cdev->online = 0;
1752                 ret = ccw_device_offline(cdev);
1753                 spin_unlock_irq(cdev->ccwlock);
1754                 if (ret == 0)
1755                         wait_event(cdev->private->wait_q,
1756                                    dev_fsm_final_state(cdev));
1757                 else
1758                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1759                                       "device 0.%x.%04x\n",
1760                                       ret, cdev->private->dev_id.ssid,
1761                                       cdev->private->dev_id.devno);
1762                 /* Give up reference obtained in ccw_device_set_online(). */
1763                 put_device(&cdev->dev);
1764                 spin_lock_irq(cdev->ccwlock);
1765         }
1766         ccw_device_set_timeout(cdev, 0);
1767         cdev->drv = NULL;
1768         cdev->private->int_class = IRQIO_CIO;
1769         sch = to_subchannel(cdev->dev.parent);
1770         spin_unlock_irq(cdev->ccwlock);
1771         io_subchannel_quiesce(sch);
1772         __disable_cmf(cdev);
1773
1774         return 0;
1775 }
1776
1777 static void ccw_device_shutdown(struct device *dev)
1778 {
1779         struct ccw_device *cdev;
1780
1781         cdev = to_ccwdev(dev);
1782         if (cdev->drv && cdev->drv->shutdown)
1783                 cdev->drv->shutdown(cdev);
1784         __disable_cmf(cdev);
1785 }
1786
1787 static struct bus_type ccw_bus_type = {
1788         .name   = "ccw",
1789         .match  = ccw_bus_match,
1790         .uevent = ccw_uevent,
1791         .probe  = ccw_device_probe,
1792         .remove = ccw_device_remove,
1793         .shutdown = ccw_device_shutdown,
1794 };
1795
1796 /**
1797  * ccw_driver_register() - register a ccw driver
1798  * @cdriver: driver to be registered
1799  *
1800  * This function is mainly a wrapper around driver_register().
1801  * Returns:
1802  *   %0 on success and a negative error value on failure.
1803  */
1804 int ccw_driver_register(struct ccw_driver *cdriver)
1805 {
1806         struct device_driver *drv = &cdriver->driver;
1807
1808         drv->bus = &ccw_bus_type;
1809
1810         return driver_register(drv);
1811 }
1812
1813 /**
1814  * ccw_driver_unregister() - deregister a ccw driver
1815  * @cdriver: driver to be deregistered
1816  *
1817  * This function is mainly a wrapper around driver_unregister().
1818  */
1819 void ccw_driver_unregister(struct ccw_driver *cdriver)
1820 {
1821         driver_unregister(&cdriver->driver);
1822 }
1823
1824 static void ccw_device_todo(struct work_struct *work)
1825 {
1826         struct ccw_device_private *priv;
1827         struct ccw_device *cdev;
1828         struct subchannel *sch;
1829         enum cdev_todo todo;
1830
1831         priv = container_of(work, struct ccw_device_private, todo_work);
1832         cdev = priv->cdev;
1833         sch = to_subchannel(cdev->dev.parent);
1834         /* Find out todo. */
1835         spin_lock_irq(cdev->ccwlock);
1836         todo = priv->todo;
1837         priv->todo = CDEV_TODO_NOTHING;
1838         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1839                       priv->dev_id.ssid, priv->dev_id.devno, todo);
1840         spin_unlock_irq(cdev->ccwlock);
1841         /* Perform todo. */
1842         switch (todo) {
1843         case CDEV_TODO_ENABLE_CMF:
1844                 cmf_reenable(cdev);
1845                 break;
1846         case CDEV_TODO_REBIND:
1847                 ccw_device_do_unbind_bind(cdev);
1848                 break;
1849         case CDEV_TODO_REGISTER:
1850                 io_subchannel_register(cdev);
1851                 break;
1852         case CDEV_TODO_UNREG_EVAL:
1853                 if (!sch_is_pseudo_sch(sch))
1854                         css_schedule_eval(sch->schid);
1855                 fallthrough;
1856         case CDEV_TODO_UNREG:
1857                 if (sch_is_pseudo_sch(sch))
1858                         ccw_device_unregister(cdev);
1859                 else
1860                         ccw_device_call_sch_unregister(cdev);
1861                 break;
1862         default:
1863                 break;
1864         }
1865         /* Release workqueue ref. */
1866         put_device(&cdev->dev);
1867 }
1868
1869 /**
1870  * ccw_device_sched_todo - schedule ccw device operation
1871  * @cdev: ccw device
1872  * @todo: todo
1873  *
1874  * Schedule the operation identified by @todo to be performed on the slow path
1875  * workqueue. Do nothing if another operation with higher priority is already
1876  * scheduled. Needs to be called with ccwdev lock held.
1877  */
1878 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
1879 {
1880         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
1881                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
1882                       todo);
1883         if (cdev->private->todo >= todo)
1884                 return;
1885         cdev->private->todo = todo;
1886         /* Get workqueue ref. */
1887         if (!get_device(&cdev->dev))
1888                 return;
1889         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
1890                 /* Already queued, release workqueue ref. */
1891                 put_device(&cdev->dev);
1892         }
1893 }
1894
1895 /**
1896  * ccw_device_siosl() - initiate logging
1897  * @cdev: ccw device
1898  *
1899  * This function is used to invoke model-dependent logging within the channel
1900  * subsystem.
1901  */
1902 int ccw_device_siosl(struct ccw_device *cdev)
1903 {
1904         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1905
1906         return chsc_siosl(sch->schid);
1907 }
1908 EXPORT_SYMBOL_GPL(ccw_device_siosl);
1909
1910 EXPORT_SYMBOL(ccw_device_set_online);
1911 EXPORT_SYMBOL(ccw_device_set_offline);
1912 EXPORT_SYMBOL(ccw_driver_register);
1913 EXPORT_SYMBOL(ccw_driver_unregister);
1914 EXPORT_SYMBOL(get_ccwdev_by_busid);