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