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                          const 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(const struct device *dev, struct kobj_uevent_env *env)
 105 {
 106         const struct ccw_device *cdev = to_ccwdev(dev);
 107         const 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 re-enable 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         else
1115                 css_schedule_eval(sch->schid);
1116 }
1117
1118 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1119 {
1120         struct ccw_device *cdev;
1121
1122         cdev = sch_get_cdev(sch);
1123         if (!cdev)
1124                 return;
1125         if (cio_update_schib(sch))
1126                 goto err;
1127         /* Check for I/O on path. */
1128         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1129                 goto out;
1130         if (cdev->private->state == DEV_STATE_ONLINE) {
1131                 ccw_device_kill_io(cdev);
1132                 goto out;
1133         }
1134         if (cio_clear(sch))
1135                 goto err;
1136 out:
1137         /* Trigger path verification. */
1138         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1139         return;
1140
1141 err:
1142         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1143 }
1144
1145 static int io_subchannel_chp_event(struct subchannel *sch,
1146                                    struct chp_link *link, int event)
1147 {
1148         struct ccw_device *cdev = sch_get_cdev(sch);
1149         int mask, chpid, valid_bit;
1150         int path_event[8];
1151
1152         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1153         if (!mask)
1154                 return 0;
1155         switch (event) {
1156         case CHP_VARY_OFF:
1157                 sch->opm &= ~mask;
1158                 sch->lpm &= ~mask;
1159                 if (cdev)
1160                         cdev->private->path_gone_mask |= mask;
1161                 io_subchannel_terminate_path(sch, mask);
1162                 break;
1163         case CHP_VARY_ON:
1164                 sch->opm |= mask;
1165                 sch->lpm |= mask;
1166                 if (cdev)
1167                         cdev->private->path_new_mask |= mask;
1168                 io_subchannel_verify(sch);
1169                 break;
1170         case CHP_OFFLINE:
1171                 if (cio_update_schib(sch))
1172                         return -ENODEV;
1173                 if (cdev)
1174                         cdev->private->path_gone_mask |= mask;
1175                 io_subchannel_terminate_path(sch, mask);
1176                 break;
1177         case CHP_ONLINE:
1178                 if (cio_update_schib(sch))
1179                         return -ENODEV;
1180                 sch->lpm |= mask & sch->opm;
1181                 if (cdev)
1182                         cdev->private->path_new_mask |= mask;
1183                 io_subchannel_verify(sch);
1184                 break;
1185         case CHP_FCES_EVENT:
1186                 /* Forward Endpoint Security event */
1187                 for (chpid = 0, valid_bit = 0x80; chpid < 8; chpid++,
1188                                 valid_bit >>= 1) {
1189                         if (mask & valid_bit)
1190                                 path_event[chpid] = PE_PATH_FCES_EVENT;
1191                         else
1192                                 path_event[chpid] = PE_NONE;
1193                 }
1194                 if (cdev && cdev->drv && cdev->drv->path_event)
1195                         cdev->drv->path_event(cdev, path_event);
1196                 break;
1197         }
1198         return 0;
1199 }
1200
1201 static void io_subchannel_quiesce(struct subchannel *sch)
1202 {
1203         struct ccw_device *cdev;
1204         int ret;
1205
1206         spin_lock_irq(sch->lock);
1207         cdev = sch_get_cdev(sch);
1208         if (cio_is_console(sch->schid))
1209                 goto out_unlock;
1210         if (!sch->schib.pmcw.ena)
1211                 goto out_unlock;
1212         ret = cio_disable_subchannel(sch);
1213         if (ret != -EBUSY)
1214                 goto out_unlock;
1215         if (cdev->handler)
1216                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1217         while (ret == -EBUSY) {
1218                 cdev->private->state = DEV_STATE_QUIESCE;
1219                 cdev->private->iretry = 255;
1220                 ret = ccw_device_cancel_halt_clear(cdev);
1221                 if (ret == -EBUSY) {
1222                         ccw_device_set_timeout(cdev, HZ/10);
1223                         spin_unlock_irq(sch->lock);
1224                         wait_event(cdev->private->wait_q,
1225                                    cdev->private->state != DEV_STATE_QUIESCE);
1226                         spin_lock_irq(sch->lock);
1227                 }
1228                 ret = cio_disable_subchannel(sch);
1229         }
1230 out_unlock:
1231         spin_unlock_irq(sch->lock);
1232 }
1233
1234 static void io_subchannel_shutdown(struct subchannel *sch)
1235 {
1236         io_subchannel_quiesce(sch);
1237 }
1238
1239 static int device_is_disconnected(struct ccw_device *cdev)
1240 {
1241         if (!cdev)
1242                 return 0;
1243         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1244                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1245 }
1246
1247 static int recovery_check(struct device *dev, void *data)
1248 {
1249         struct ccw_device *cdev = to_ccwdev(dev);
1250         struct subchannel *sch;
1251         int *redo = data;
1252
1253         spin_lock_irq(cdev->ccwlock);
1254         switch (cdev->private->state) {
1255         case DEV_STATE_ONLINE:
1256                 sch = to_subchannel(cdev->dev.parent);
1257                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1258                         break;
1259                 fallthrough;
1260         case DEV_STATE_DISCONNECTED:
1261                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1262                               cdev->private->dev_id.ssid,
1263                               cdev->private->dev_id.devno);
1264                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1265                 *redo = 1;
1266                 break;
1267         case DEV_STATE_DISCONNECTED_SENSE_ID:
1268                 *redo = 1;
1269                 break;
1270         }
1271         spin_unlock_irq(cdev->ccwlock);
1272
1273         return 0;
1274 }
1275
1276 static void recovery_work_func(struct work_struct *unused)
1277 {
1278         int redo = 0;
1279
1280         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1281         if (redo) {
1282                 spin_lock_irq(&recovery_lock);
1283                 if (!timer_pending(&recovery_timer)) {
1284                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1285                                 recovery_phase++;
1286                         mod_timer(&recovery_timer, jiffies +
1287                                   recovery_delay[recovery_phase] * HZ);
1288                 }
1289                 spin_unlock_irq(&recovery_lock);
1290         } else
1291                 CIO_MSG_EVENT(3, "recovery: end\n");
1292 }
1293
1294 static DECLARE_WORK(recovery_work, recovery_work_func);
1295
1296 static void recovery_func(struct timer_list *unused)
1297 {
1298         /*
1299          * We can't do our recovery in softirq context and it's not
1300          * performance critical, so we schedule it.
1301          */
1302         schedule_work(&recovery_work);
1303 }
1304
1305 void ccw_device_schedule_recovery(void)
1306 {
1307         unsigned long flags;
1308
1309         CIO_MSG_EVENT(3, "recovery: schedule\n");
1310         spin_lock_irqsave(&recovery_lock, flags);
1311         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1312                 recovery_phase = 0;
1313                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1314         }
1315         spin_unlock_irqrestore(&recovery_lock, flags);
1316 }
1317
1318 static int purge_fn(struct device *dev, void *data)
1319 {
1320         struct ccw_device *cdev = to_ccwdev(dev);
1321         struct ccw_dev_id *id = &cdev->private->dev_id;
1322         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1323
1324         spin_lock_irq(cdev->ccwlock);
1325         if (is_blacklisted(id->ssid, id->devno) &&
1326             (cdev->private->state == DEV_STATE_OFFLINE) &&
1327             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1328                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1329                               id->devno);
1330                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1331                 css_sched_sch_todo(sch, SCH_TODO_UNREG);
1332                 atomic_set(&cdev->private->onoff, 0);
1333         }
1334         spin_unlock_irq(cdev->ccwlock);
1335         /* Abort loop in case of pending signal. */
1336         if (signal_pending(current))
1337                 return -EINTR;
1338
1339         return 0;
1340 }
1341
1342 /**
1343  * ccw_purge_blacklisted - purge unused, blacklisted devices
1344  *
1345  * Unregister all ccw devices that are offline and on the blacklist.
1346  */
1347 int ccw_purge_blacklisted(void)
1348 {
1349         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1350         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1351         return 0;
1352 }
1353
1354 void ccw_device_set_disconnected(struct ccw_device *cdev)
1355 {
1356         if (!cdev)
1357                 return;
1358         ccw_device_set_timeout(cdev, 0);
1359         cdev->private->flags.fake_irb = 0;
1360         cdev->private->state = DEV_STATE_DISCONNECTED;
1361         if (cdev->online)
1362                 ccw_device_schedule_recovery();
1363 }
1364
1365 void ccw_device_set_notoper(struct ccw_device *cdev)
1366 {
1367         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1368
1369         CIO_TRACE_EVENT(2, "notoper");
1370         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1371         ccw_device_set_timeout(cdev, 0);
1372         cio_disable_subchannel(sch);
1373         cdev->private->state = DEV_STATE_NOT_OPER;
1374 }
1375
1376 enum io_sch_action {
1377         IO_SCH_UNREG,
1378         IO_SCH_ORPH_UNREG,
1379         IO_SCH_UNREG_CDEV,
1380         IO_SCH_ATTACH,
1381         IO_SCH_UNREG_ATTACH,
1382         IO_SCH_ORPH_ATTACH,
1383         IO_SCH_REPROBE,
1384         IO_SCH_VERIFY,
1385         IO_SCH_DISC,
1386         IO_SCH_NOP,
1387 };
1388
1389 static enum io_sch_action sch_get_action(struct subchannel *sch)
1390 {
1391         struct ccw_device *cdev;
1392
1393         cdev = sch_get_cdev(sch);
1394         if (cio_update_schib(sch)) {
1395                 /* Not operational. */
1396                 if (!cdev)
1397                         return IO_SCH_UNREG;
1398                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1399                         return IO_SCH_UNREG;
1400                 return IO_SCH_ORPH_UNREG;
1401         }
1402         /* Operational. */
1403         if (!cdev)
1404                 return IO_SCH_ATTACH;
1405         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1406                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1407                         return IO_SCH_UNREG_ATTACH;
1408                 return IO_SCH_ORPH_ATTACH;
1409         }
1410         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1411                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1412                         return IO_SCH_UNREG_CDEV;
1413                 return IO_SCH_DISC;
1414         }
1415         if (device_is_disconnected(cdev))
1416                 return IO_SCH_REPROBE;
1417         if (cdev->online)
1418                 return IO_SCH_VERIFY;
1419         if (cdev->private->state == DEV_STATE_NOT_OPER)
1420                 return IO_SCH_UNREG_ATTACH;
1421         return IO_SCH_NOP;
1422 }
1423
1424 /**
1425  * io_subchannel_sch_event - process subchannel event
1426  * @sch: subchannel
1427  * @process: non-zero if function is called in process context
1428  *
1429  * An unspecified event occurred for this subchannel. Adjust data according
1430  * to the current operational state of the subchannel and device. Return
1431  * zero when the event has been handled sufficiently or -EAGAIN when this
1432  * function should be called again in process context.
1433  */
1434 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1435 {
1436         unsigned long flags;
1437         struct ccw_device *cdev;
1438         struct ccw_dev_id dev_id;
1439         enum io_sch_action action;
1440         int rc = -EAGAIN;
1441
1442         spin_lock_irqsave(sch->lock, flags);
1443         if (!device_is_registered(&sch->dev))
1444                 goto out_unlock;
1445         if (work_pending(&sch->todo_work))
1446                 goto out_unlock;
1447         cdev = sch_get_cdev(sch);
1448         if (cdev && work_pending(&cdev->private->todo_work))
1449                 goto out_unlock;
1450         action = sch_get_action(sch);
1451         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1452                       sch->schid.ssid, sch->schid.sch_no, process,
1453                       action);
1454         /* Perform immediate actions while holding the lock. */
1455         switch (action) {
1456         case IO_SCH_REPROBE:
1457                 /* Trigger device recognition. */
1458                 ccw_device_trigger_reprobe(cdev);
1459                 rc = 0;
1460                 goto out_unlock;
1461         case IO_SCH_VERIFY:
1462                 /* Trigger path verification. */
1463                 io_subchannel_verify(sch);
1464                 rc = 0;
1465                 goto out_unlock;
1466         case IO_SCH_DISC:
1467                 ccw_device_set_disconnected(cdev);
1468                 rc = 0;
1469                 goto out_unlock;
1470         case IO_SCH_ORPH_UNREG:
1471         case IO_SCH_ORPH_ATTACH:
1472                 ccw_device_set_disconnected(cdev);
1473                 break;
1474         case IO_SCH_UNREG_CDEV:
1475         case IO_SCH_UNREG_ATTACH:
1476         case IO_SCH_UNREG:
1477                 if (!cdev)
1478                         break;
1479                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1480                         /*
1481                          * Note: delayed work triggered by this event
1482                          * and repeated calls to sch_event are synchronized
1483                          * by the above check for work_pending(cdev).
1484                          */
1485                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1486                 } else
1487                         ccw_device_set_notoper(cdev);
1488                 break;
1489         case IO_SCH_NOP:
1490                 rc = 0;
1491                 goto out_unlock;
1492         default:
1493                 break;
1494         }
1495         spin_unlock_irqrestore(sch->lock, flags);
1496         /* All other actions require process context. */
1497         if (!process)
1498                 goto out;
1499         /* Handle attached ccw device. */
1500         switch (action) {
1501         case IO_SCH_ORPH_UNREG:
1502         case IO_SCH_ORPH_ATTACH:
1503                 /* Move ccw device to orphanage. */
1504                 rc = ccw_device_move_to_orph(cdev);
1505                 if (rc)
1506                         goto out;
1507                 break;
1508         case IO_SCH_UNREG_CDEV:
1509         case IO_SCH_UNREG_ATTACH:
1510                 spin_lock_irqsave(sch->lock, flags);
1511                 sch_set_cdev(sch, NULL);
1512                 spin_unlock_irqrestore(sch->lock, flags);
1513                 /* Unregister ccw device. */
1514                 ccw_device_unregister(cdev);
1515                 break;
1516         default:
1517                 break;
1518         }
1519         /* Handle subchannel. */
1520         switch (action) {
1521         case IO_SCH_ORPH_UNREG:
1522         case IO_SCH_UNREG:
1523                 css_sch_device_unregister(sch);
1524                 break;
1525         case IO_SCH_ORPH_ATTACH:
1526         case IO_SCH_UNREG_ATTACH:
1527         case IO_SCH_ATTACH:
1528                 dev_id.ssid = sch->schid.ssid;
1529                 dev_id.devno = sch->schib.pmcw.dev;
1530                 cdev = get_ccwdev_by_dev_id(&dev_id);
1531                 if (!cdev) {
1532                         sch_create_and_recog_new_device(sch);
1533                         break;
1534                 }
1535                 rc = ccw_device_move_to_sch(cdev, sch);
1536                 if (rc) {
1537                         /* Release reference from get_ccwdev_by_dev_id() */
1538                         put_device(&cdev->dev);
1539                         goto out;
1540                 }
1541                 spin_lock_irqsave(sch->lock, flags);
1542                 ccw_device_trigger_reprobe(cdev);
1543                 spin_unlock_irqrestore(sch->lock, flags);
1544                 /* Release reference from get_ccwdev_by_dev_id() */
1545                 put_device(&cdev->dev);
1546                 break;
1547         default:
1548                 break;
1549         }
1550         return 0;
1551
1552 out_unlock:
1553         spin_unlock_irqrestore(sch->lock, flags);
1554 out:
1555         return rc;
1556 }
1557
1558 static void ccw_device_set_int_class(struct ccw_device *cdev)
1559 {
1560         struct ccw_driver *cdrv = cdev->drv;
1561
1562         /* Note: we interpret class 0 in this context as an uninitialized
1563          * field since it translates to a non-I/O interrupt class. */
1564         if (cdrv->int_class != 0)
1565                 cdev->private->int_class = cdrv->int_class;
1566         else
1567                 cdev->private->int_class = IRQIO_CIO;
1568 }
1569
1570 #ifdef CONFIG_CCW_CONSOLE
1571 int __init ccw_device_enable_console(struct ccw_device *cdev)
1572 {
1573         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1574         int rc;
1575
1576         if (!cdev->drv || !cdev->handler)
1577                 return -EINVAL;
1578
1579         io_subchannel_init_fields(sch);
1580         rc = cio_commit_config(sch);
1581         if (rc)
1582                 return rc;
1583         sch->driver = &io_subchannel_driver;
1584         io_subchannel_recog(cdev, sch);
1585         /* Now wait for the async. recognition to come to an end. */
1586         spin_lock_irq(cdev->ccwlock);
1587         while (!dev_fsm_final_state(cdev))
1588                 ccw_device_wait_idle(cdev);
1589
1590         /* Hold on to an extra reference while device is online. */
1591         get_device(&cdev->dev);
1592         rc = ccw_device_online(cdev);
1593         if (rc)
1594                 goto out_unlock;
1595
1596         while (!dev_fsm_final_state(cdev))
1597                 ccw_device_wait_idle(cdev);
1598
1599         if (cdev->private->state == DEV_STATE_ONLINE)
1600                 cdev->online = 1;
1601         else
1602                 rc = -EIO;
1603 out_unlock:
1604         spin_unlock_irq(cdev->ccwlock);
1605         if (rc) /* Give up online reference since onlining failed. */
1606                 put_device(&cdev->dev);
1607         return rc;
1608 }
1609
1610 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1611 {
1612         struct io_subchannel_private *io_priv;
1613         struct ccw_device *cdev;
1614         struct subchannel *sch;
1615
1616         sch = cio_probe_console();
1617         if (IS_ERR(sch))
1618                 return ERR_CAST(sch);
1619
1620         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1621         if (!io_priv)
1622                 goto err_priv;
1623         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1624                                 sizeof(*io_priv->dma_area),
1625                                 &io_priv->dma_area_dma, GFP_KERNEL);
1626         if (!io_priv->dma_area)
1627                 goto err_dma_area;
1628         set_io_private(sch, io_priv);
1629         cdev = io_subchannel_create_ccwdev(sch);
1630         if (IS_ERR(cdev)) {
1631                 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1632                                   io_priv->dma_area, io_priv->dma_area_dma);
1633                 set_io_private(sch, NULL);
1634                 put_device(&sch->dev);
1635                 kfree(io_priv);
1636                 return cdev;
1637         }
1638         cdev->drv = drv;
1639         ccw_device_set_int_class(cdev);
1640         return cdev;
1641
1642 err_dma_area:
1643         kfree(io_priv);
1644 err_priv:
1645         put_device(&sch->dev);
1646         return ERR_PTR(-ENOMEM);
1647 }
1648
1649 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1650 {
1651         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1652         struct io_subchannel_private *io_priv = to_io_private(sch);
1653
1654         set_io_private(sch, NULL);
1655         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1656                           io_priv->dma_area, io_priv->dma_area_dma);
1657         put_device(&sch->dev);
1658         put_device(&cdev->dev);
1659         kfree(io_priv);
1660 }
1661
1662 /**
1663  * ccw_device_wait_idle() - busy wait for device to become idle
1664  * @cdev: ccw device
1665  *
1666  * Poll until activity control is zero, that is, no function or data
1667  * transfer is pending/active.
1668  * Called with device lock being held.
1669  */
1670 void ccw_device_wait_idle(struct ccw_device *cdev)
1671 {
1672         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1673
1674         while (1) {
1675                 cio_tsch(sch);
1676                 if (sch->schib.scsw.cmd.actl == 0)
1677                         break;
1678                 udelay(100);
1679         }
1680 }
1681 #endif
1682
1683 /**
1684  * get_ccwdev_by_busid() - obtain device from a bus id
1685  * @cdrv: driver the device is owned by
1686  * @bus_id: bus id of the device to be searched
1687  *
1688  * This function searches all devices owned by @cdrv for a device with a bus
1689  * id matching @bus_id.
1690  * Returns:
1691  *  If a match is found, its reference count of the found device is increased
1692  *  and it is returned; else %NULL is returned.
1693  */
1694 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1695                                        const char *bus_id)
1696 {
1697         struct device *dev;
1698
1699         dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1700
1701         return dev ? to_ccwdev(dev) : NULL;
1702 }
1703
1704 /************************** device driver handling ************************/
1705
1706 /* This is the implementation of the ccw_driver class. The probe, remove
1707  * and release methods are initially very similar to the device_driver
1708  * implementations, with the difference that they have ccw_device
1709  * arguments.
1710  *
1711  * A ccw driver also contains the information that is needed for
1712  * device matching.
1713  */
1714 static int
1715 ccw_device_probe (struct device *dev)
1716 {
1717         struct ccw_device *cdev = to_ccwdev(dev);
1718         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1719         int ret;
1720
1721         cdev->drv = cdrv; /* to let the driver call _set_online */
1722         ccw_device_set_int_class(cdev);
1723         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1724         if (ret) {
1725                 cdev->drv = NULL;
1726                 cdev->private->int_class = IRQIO_CIO;
1727                 return ret;
1728         }
1729
1730         return 0;
1731 }
1732
1733 static void ccw_device_remove(struct device *dev)
1734 {
1735         struct ccw_device *cdev = to_ccwdev(dev);
1736         struct ccw_driver *cdrv = cdev->drv;
1737         struct subchannel *sch;
1738         int ret;
1739
1740         if (cdrv->remove)
1741                 cdrv->remove(cdev);
1742
1743         spin_lock_irq(cdev->ccwlock);
1744         if (cdev->online) {
1745                 cdev->online = 0;
1746                 ret = ccw_device_offline(cdev);
1747                 spin_unlock_irq(cdev->ccwlock);
1748                 if (ret == 0)
1749                         wait_event(cdev->private->wait_q,
1750                                    dev_fsm_final_state(cdev));
1751                 else
1752                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1753                                       "device 0.%x.%04x\n",
1754                                       ret, cdev->private->dev_id.ssid,
1755                                       cdev->private->dev_id.devno);
1756                 /* Give up reference obtained in ccw_device_set_online(). */
1757                 put_device(&cdev->dev);
1758                 spin_lock_irq(cdev->ccwlock);
1759         }
1760         ccw_device_set_timeout(cdev, 0);
1761         cdev->drv = NULL;
1762         cdev->private->int_class = IRQIO_CIO;
1763         sch = to_subchannel(cdev->dev.parent);
1764         spin_unlock_irq(cdev->ccwlock);
1765         io_subchannel_quiesce(sch);
1766         __disable_cmf(cdev);
1767 }
1768
1769 static void ccw_device_shutdown(struct device *dev)
1770 {
1771         struct ccw_device *cdev;
1772
1773         cdev = to_ccwdev(dev);
1774         if (cdev->drv && cdev->drv->shutdown)
1775                 cdev->drv->shutdown(cdev);
1776         __disable_cmf(cdev);
1777 }
1778
1779 static struct bus_type ccw_bus_type = {
1780         .name   = "ccw",
1781         .match  = ccw_bus_match,
1782         .uevent = ccw_uevent,
1783         .probe  = ccw_device_probe,
1784         .remove = ccw_device_remove,
1785         .shutdown = ccw_device_shutdown,
1786 };
1787
1788 /**
1789  * ccw_driver_register() - register a ccw driver
1790  * @cdriver: driver to be registered
1791  *
1792  * This function is mainly a wrapper around driver_register().
1793  * Returns:
1794  *   %0 on success and a negative error value on failure.
1795  */
1796 int ccw_driver_register(struct ccw_driver *cdriver)
1797 {
1798         struct device_driver *drv = &cdriver->driver;
1799
1800         drv->bus = &ccw_bus_type;
1801
1802         return driver_register(drv);
1803 }
1804
1805 /**
1806  * ccw_driver_unregister() - deregister a ccw driver
1807  * @cdriver: driver to be deregistered
1808  *
1809  * This function is mainly a wrapper around driver_unregister().
1810  */
1811 void ccw_driver_unregister(struct ccw_driver *cdriver)
1812 {
1813         driver_unregister(&cdriver->driver);
1814 }
1815
1816 static void ccw_device_todo(struct work_struct *work)
1817 {
1818         struct ccw_device_private *priv;
1819         struct ccw_device *cdev;
1820         struct subchannel *sch;
1821         enum cdev_todo todo;
1822
1823         priv = container_of(work, struct ccw_device_private, todo_work);
1824         cdev = priv->cdev;
1825         sch = to_subchannel(cdev->dev.parent);
1826         /* Find out todo. */
1827         spin_lock_irq(cdev->ccwlock);
1828         todo = priv->todo;
1829         priv->todo = CDEV_TODO_NOTHING;
1830         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1831                       priv->dev_id.ssid, priv->dev_id.devno, todo);
1832         spin_unlock_irq(cdev->ccwlock);
1833         /* Perform todo. */
1834         switch (todo) {
1835         case CDEV_TODO_ENABLE_CMF:
1836                 cmf_reenable(cdev);
1837                 break;
1838         case CDEV_TODO_REBIND:
1839                 ccw_device_do_unbind_bind(cdev);
1840                 break;
1841         case CDEV_TODO_REGISTER:
1842                 io_subchannel_register(cdev);
1843                 break;
1844         case CDEV_TODO_UNREG_EVAL:
1845                 if (!sch_is_pseudo_sch(sch))
1846                         css_schedule_eval(sch->schid);
1847                 fallthrough;
1848         case CDEV_TODO_UNREG:
1849                 spin_lock_irq(sch->lock);
1850                 sch_set_cdev(sch, NULL);
1851                 spin_unlock_irq(sch->lock);
1852                 ccw_device_unregister(cdev);
1853                 break;
1854         default:
1855                 break;
1856         }
1857         /* Release workqueue ref. */
1858         put_device(&cdev->dev);
1859 }
1860
1861 /**
1862  * ccw_device_sched_todo - schedule ccw device operation
1863  * @cdev: ccw device
1864  * @todo: todo
1865  *
1866  * Schedule the operation identified by @todo to be performed on the slow path
1867  * workqueue. Do nothing if another operation with higher priority is already
1868  * scheduled. Needs to be called with ccwdev lock held.
1869  */
1870 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
1871 {
1872         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
1873                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
1874                       todo);
1875         if (cdev->private->todo >= todo)
1876                 return;
1877         cdev->private->todo = todo;
1878         /* Get workqueue ref. */
1879         if (!get_device(&cdev->dev))
1880                 return;
1881         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
1882                 /* Already queued, release workqueue ref. */
1883                 put_device(&cdev->dev);
1884         }
1885 }
1886
1887 /**
1888  * ccw_device_siosl() - initiate logging
1889  * @cdev: ccw device
1890  *
1891  * This function is used to invoke model-dependent logging within the channel
1892  * subsystem.
1893  */
1894 int ccw_device_siosl(struct ccw_device *cdev)
1895 {
1896         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1897
1898         return chsc_siosl(sch->schid);
1899 }
1900 EXPORT_SYMBOL_GPL(ccw_device_siosl);
1901
1902 EXPORT_SYMBOL(ccw_device_set_online);
1903 EXPORT_SYMBOL(ccw_device_set_offline);
1904 EXPORT_SYMBOL(ccw_driver_register);
1905 EXPORT_SYMBOL(ccw_driver_unregister);
1906 EXPORT_SYMBOL(get_ccwdev_by_busid);