drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.140 $
   5  *
   6  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   7  *                       IBM Corporation
   8  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   9  *               Cornelia Huck (cornelia.huck@de.ibm.com)
  10  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  11  */
  12 #include <linux/config.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/slab.h>
  19 #include <linux/list.h>
  20 #include <linux/device.h>
  21 #include <linux/workqueue.h>
  22
  23 #include <asm/ccwdev.h>
  24 #include <asm/cio.h>
  25 #include <asm/param.h>          /* HZ */
  26
  27 #include "cio.h"
  28 #include "css.h"
  29 #include "device.h"
  30 #include "ioasm.h"
  31
  32 /******************* bus type handling ***********************/
  33
  34 /* The Linux driver model distinguishes between a bus type and
  35  * the bus itself. Of course we only have one channel
  36  * subsystem driver and one channel system per machine, but
  37  * we still use the abstraction. T.R. says it's a good idea. */
  38 static int
  39 ccw_bus_match (struct device * dev, struct device_driver * drv)
  40 {
  41         struct ccw_device *cdev = to_ccwdev(dev);
  42         struct ccw_driver *cdrv = to_ccwdrv(drv);
  43         const struct ccw_device_id *ids = cdrv->ids, *found;
  44
  45         if (!ids)
  46                 return 0;
  47
  48         found = ccw_device_id_match(ids, &cdev->id);
  49         if (!found)
  50                 return 0;
  51
  52         cdev->id.driver_info = found->driver_info;
  53
  54         return 1;
  55 }
  56
  57 /*
  58  * Hotplugging interface for ccw devices.
  59  * Heavily modeled on pci and usb hotplug.
  60  */
  61 static int
  62 ccw_uevent (struct device *dev, char **envp, int num_envp,
  63              char *buffer, int buffer_size)
  64 {
  65         struct ccw_device *cdev = to_ccwdev(dev);
  66         int i = 0;
  67         int length = 0;
  68
  69         if (!cdev)
  70                 return -ENODEV;
  71
  72         /* what we want to pass to /sbin/hotplug */
  73
  74         envp[i++] = buffer;
  75         length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
  76                            cdev->id.cu_type);
  77         if ((buffer_size - length <= 0) || (i >= num_envp))
  78                 return -ENOMEM;
  79         ++length;
  80         buffer += length;
  81
  82         envp[i++] = buffer;
  83         length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
  84                            cdev->id.cu_model);
  85         if ((buffer_size - length <= 0) || (i >= num_envp))
  86                 return -ENOMEM;
  87         ++length;
  88         buffer += length;
  89
  90         /* The next two can be zero, that's ok for us */
  91         envp[i++] = buffer;
  92         length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
  93                            cdev->id.dev_type);
  94         if ((buffer_size - length <= 0) || (i >= num_envp))
  95                 return -ENOMEM;
  96         ++length;
  97         buffer += length;
  98
  99         envp[i++] = buffer;
 100         length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
 101                            cdev->id.dev_model);
 102         if ((buffer_size - length <= 0) || (i >= num_envp))
 103                 return -ENOMEM;
 104
 105         envp[i] = 0;
 106
 107         return 0;
 108 }
 109
 110 struct bus_type ccw_bus_type;
 111
 112 static int io_subchannel_probe (struct subchannel *);
 113 static int io_subchannel_remove (struct subchannel *);
 114 void io_subchannel_irq (struct device *);
 115 static int io_subchannel_notify(struct device *, int);
 116 static void io_subchannel_verify(struct device *);
 117 static void io_subchannel_ioterm(struct device *);
 118 static void io_subchannel_shutdown(struct subchannel *);
 119
 120 struct css_driver io_subchannel_driver = {
 121         .subchannel_type = SUBCHANNEL_TYPE_IO,
 122         .drv = {
 123                 .name = "io_subchannel",
 124                 .bus  = &css_bus_type,
 125         },
 126         .irq = io_subchannel_irq,
 127         .notify = io_subchannel_notify,
 128         .verify = io_subchannel_verify,
 129         .termination = io_subchannel_ioterm,
 130         .probe = io_subchannel_probe,
 131         .remove = io_subchannel_remove,
 132         .shutdown = io_subchannel_shutdown,
 133 };
 134
 135 struct workqueue_struct *ccw_device_work;
 136 struct workqueue_struct *ccw_device_notify_work;
 137 static wait_queue_head_t ccw_device_init_wq;
 138 static atomic_t ccw_device_init_count;
 139
 140 static int __init
 141 init_ccw_bus_type (void)
 142 {
 143         int ret;
 144
 145         init_waitqueue_head(&ccw_device_init_wq);
 146         atomic_set(&ccw_device_init_count, 0);
 147
 148         ccw_device_work = create_singlethread_workqueue("cio");
 149         if (!ccw_device_work)
 150                 return -ENOMEM; /* FIXME: better errno ? */
 151         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 152         if (!ccw_device_notify_work) {
 153                 ret = -ENOMEM; /* FIXME: better errno ? */
 154                 goto out_err;
 155         }
 156         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 157         if (!slow_path_wq) {
 158                 ret = -ENOMEM; /* FIXME: better errno ? */
 159                 goto out_err;
 160         }
 161         if ((ret = bus_register (&ccw_bus_type)))
 162                 goto out_err;
 163
 164         if ((ret = driver_register(&io_subchannel_driver.drv)))
 165                 goto out_err;
 166
 167         wait_event(ccw_device_init_wq,
 168                    atomic_read(&ccw_device_init_count) == 0);
 169         flush_workqueue(ccw_device_work);
 170         return 0;
 171 out_err:
 172         if (ccw_device_work)
 173                 destroy_workqueue(ccw_device_work);
 174         if (ccw_device_notify_work)
 175                 destroy_workqueue(ccw_device_notify_work);
 176         if (slow_path_wq)
 177                 destroy_workqueue(slow_path_wq);
 178         return ret;
 179 }
 180
 181 static void __exit
 182 cleanup_ccw_bus_type (void)
 183 {
 184         driver_unregister(&io_subchannel_driver.drv);
 185         bus_unregister(&ccw_bus_type);
 186         destroy_workqueue(ccw_device_notify_work);
 187         destroy_workqueue(ccw_device_work);
 188 }
 189
 190 subsys_initcall(init_ccw_bus_type);
 191 module_exit(cleanup_ccw_bus_type);
 192
 193 /************************ device handling **************************/
 194
 195 /*
 196  * A ccw_device has some interfaces in sysfs in addition to the
 197  * standard ones.
 198  * The following entries are designed to export the information which
 199  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 200  * are obvious, so they don't have an entry :)
 201  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 202  */
 203 static ssize_t
 204 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 205 {
 206         struct subchannel *sch = to_subchannel(dev);
 207         struct ssd_info *ssd = &sch->ssd_info;
 208         ssize_t ret = 0;
 209         int chp;
 210
 211         for (chp = 0; chp < 8; chp++)
 212                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 213
 214         ret += sprintf (buf+ret, "\n");
 215         return min((ssize_t)PAGE_SIZE, ret);
 216 }
 217
 218 static ssize_t
 219 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 220 {
 221         struct subchannel *sch = to_subchannel(dev);
 222         struct pmcw *pmcw = &sch->schib.pmcw;
 223
 224         return sprintf (buf, "%02x %02x %02x\n",
 225                         pmcw->pim, pmcw->pam, pmcw->pom);
 226 }
 227
 228 static ssize_t
 229 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 230 {
 231         struct ccw_device *cdev = to_ccwdev(dev);
 232         struct ccw_device_id *id = &(cdev->id);
 233
 234         if (id->dev_type != 0)
 235                 return sprintf(buf, "%04x/%02x\n",
 236                                 id->dev_type, id->dev_model);
 237         else
 238                 return sprintf(buf, "n/a\n");
 239 }
 240
 241 static ssize_t
 242 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 243 {
 244         struct ccw_device *cdev = to_ccwdev(dev);
 245         struct ccw_device_id *id = &(cdev->id);
 246
 247         return sprintf(buf, "%04x/%02x\n",
 248                        id->cu_type, id->cu_model);
 249 }
 250
 251 static ssize_t
 252 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 253 {
 254         struct ccw_device *cdev = to_ccwdev(dev);
 255         struct ccw_device_id *id = &(cdev->id);
 256         int ret;
 257
 258         ret = sprintf(buf, "ccw:t%04Xm%02x",
 259                         id->cu_type, id->cu_model);
 260         if (id->dev_type != 0)
 261                 ret += sprintf(buf + ret, "dt%04Xdm%02X\n",
 262                                 id->dev_type, id->dev_model);
 263         else
 264                 ret += sprintf(buf + ret, "dtdm\n");
 265         return ret;
 266 }
 267
 268 static ssize_t
 269 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 270 {
 271         struct ccw_device *cdev = to_ccwdev(dev);
 272
 273         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 274 }
 275
 276 static void
 277 ccw_device_remove_disconnected(struct ccw_device *cdev)
 278 {
 279         struct subchannel *sch;
 280         /*
 281          * Forced offline in disconnected state means
 282          * 'throw away device'.
 283          */
 284         sch = to_subchannel(cdev->dev.parent);
 285         device_unregister(&sch->dev);
 286         /* Reset intparm to zeroes. */
 287         sch->schib.pmcw.intparm = 0;
 288         cio_modify(sch);
 289         put_device(&sch->dev);
 290 }
 291
 292 int
 293 ccw_device_set_offline(struct ccw_device *cdev)
 294 {
 295         int ret;
 296
 297         if (!cdev)
 298                 return -ENODEV;
 299         if (!cdev->online || !cdev->drv)
 300                 return -EINVAL;
 301
 302         if (cdev->drv->set_offline) {
 303                 ret = cdev->drv->set_offline(cdev);
 304                 if (ret != 0)
 305                         return ret;
 306         }
 307         cdev->online = 0;
 308         spin_lock_irq(cdev->ccwlock);
 309         ret = ccw_device_offline(cdev);
 310         if (ret == -ENODEV) {
 311                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 312                         cdev->private->state = DEV_STATE_OFFLINE;
 313                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 314                 }
 315                 spin_unlock_irq(cdev->ccwlock);
 316                 return ret;
 317         }
 318         spin_unlock_irq(cdev->ccwlock);
 319         if (ret == 0)
 320                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 321         else {
 322                 pr_debug("ccw_device_offline returned %d, device %s\n",
 323                          ret, cdev->dev.bus_id);
 324                 cdev->online = 1;
 325         }
 326         return ret;
 327 }
 328
 329 int
 330 ccw_device_set_online(struct ccw_device *cdev)
 331 {
 332         int ret;
 333
 334         if (!cdev)
 335                 return -ENODEV;
 336         if (cdev->online || !cdev->drv)
 337                 return -EINVAL;
 338
 339         spin_lock_irq(cdev->ccwlock);
 340         ret = ccw_device_online(cdev);
 341         spin_unlock_irq(cdev->ccwlock);
 342         if (ret == 0)
 343                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 344         else {
 345                 pr_debug("ccw_device_online returned %d, device %s\n",
 346                          ret, cdev->dev.bus_id);
 347                 return ret;
 348         }
 349         if (cdev->private->state != DEV_STATE_ONLINE)
 350                 return -ENODEV;
 351         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 352                 cdev->online = 1;
 353                 return 0;
 354         }
 355         spin_lock_irq(cdev->ccwlock);
 356         ret = ccw_device_offline(cdev);
 357         spin_unlock_irq(cdev->ccwlock);
 358         if (ret == 0)
 359                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 360         else
 361                 pr_debug("ccw_device_offline returned %d, device %s\n",
 362                          ret, cdev->dev.bus_id);
 363         return (ret = 0) ? -ENODEV : ret;
 364 }
 365
 366 static ssize_t
 367 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 368 {
 369         struct ccw_device *cdev = to_ccwdev(dev);
 370         int i, force, ret;
 371         char *tmp;
 372
 373         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 374                 return -EAGAIN;
 375
 376         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 377                 atomic_set(&cdev->private->onoff, 0);
 378                 return -EINVAL;
 379         }
 380         if (!strncmp(buf, "force\n", count)) {
 381                 force = 1;
 382                 i = 1;
 383         } else {
 384                 force = 0;
 385                 i = simple_strtoul(buf, &tmp, 16);
 386         }
 387         if (i == 1) {
 388                 /* Do device recognition, if needed. */
 389                 if (cdev->id.cu_type == 0) {
 390                         ret = ccw_device_recognition(cdev);
 391                         if (ret) {
 392                                 printk(KERN_WARNING"Couldn't start recognition "
 393                                        "for device %s (ret=%d)\n",
 394                                        cdev->dev.bus_id, ret);
 395                                 goto out;
 396                         }
 397                         wait_event(cdev->private->wait_q,
 398                                    cdev->private->flags.recog_done);
 399                 }
 400                 if (cdev->drv && cdev->drv->set_online)
 401                         ccw_device_set_online(cdev);
 402         } else if (i == 0) {
 403                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 404                         ccw_device_remove_disconnected(cdev);
 405                 else if (cdev->drv && cdev->drv->set_offline)
 406                         ccw_device_set_offline(cdev);
 407         }
 408         if (force && cdev->private->state == DEV_STATE_BOXED) {
 409                 ret = ccw_device_stlck(cdev);
 410                 if (ret) {
 411                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 412                                "returned %d!\n", cdev->dev.bus_id, ret);
 413                         goto out;
 414                 }
 415                 /* Do device recognition, if needed. */
 416                 if (cdev->id.cu_type == 0) {
 417                         cdev->private->state = DEV_STATE_NOT_OPER;
 418                         ret = ccw_device_recognition(cdev);
 419                         if (ret) {
 420                                 printk(KERN_WARNING"Couldn't start recognition "
 421                                        "for device %s (ret=%d)\n",
 422                                        cdev->dev.bus_id, ret);
 423                                 goto out;
 424                         }
 425                         wait_event(cdev->private->wait_q,
 426                                    cdev->private->flags.recog_done);
 427                 }
 428                 if (cdev->drv && cdev->drv->set_online)
 429                         ccw_device_set_online(cdev);
 430         }
 431         out:
 432         if (cdev->drv)
 433                 module_put(cdev->drv->owner);
 434         atomic_set(&cdev->private->onoff, 0);
 435         return count;
 436 }
 437
 438 static ssize_t
 439 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 440 {
 441         struct ccw_device *cdev = to_ccwdev(dev);
 442         struct subchannel *sch;
 443
 444         switch (cdev->private->state) {
 445         case DEV_STATE_BOXED:
 446                 return sprintf(buf, "boxed\n");
 447         case DEV_STATE_DISCONNECTED:
 448         case DEV_STATE_DISCONNECTED_SENSE_ID:
 449         case DEV_STATE_NOT_OPER:
 450                 sch = to_subchannel(dev->parent);
 451                 if (!sch->lpm)
 452                         return sprintf(buf, "no path\n");
 453                 else
 454                         return sprintf(buf, "no device\n");
 455         default:
 456                 /* All other states considered fine. */
 457                 return sprintf(buf, "good\n");
 458         }
 459 }
 460
 461 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 462 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 463 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 464 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 465 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 466 static DEVICE_ATTR(online, 0644, online_show, online_store);
 467 extern struct device_attribute dev_attr_cmb_enable;
 468 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 469
 470 static struct attribute * subch_attrs[] = {
 471         &dev_attr_chpids.attr,
 472         &dev_attr_pimpampom.attr,
 473         NULL,
 474 };
 475
 476 static struct attribute_group subch_attr_group = {
 477         .attrs = subch_attrs,
 478 };
 479
 480 static inline int
 481 subchannel_add_files (struct device *dev)
 482 {
 483         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 484 }
 485
 486 static struct attribute * ccwdev_attrs[] = {
 487         &dev_attr_devtype.attr,
 488         &dev_attr_cutype.attr,
 489         &dev_attr_modalias.attr,
 490         &dev_attr_online.attr,
 491         &dev_attr_cmb_enable.attr,
 492         &dev_attr_availability.attr,
 493         NULL,
 494 };
 495
 496 static struct attribute_group ccwdev_attr_group = {
 497         .attrs = ccwdev_attrs,
 498 };
 499
 500 static inline int
 501 device_add_files (struct device *dev)
 502 {
 503         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 504 }
 505
 506 static inline void
 507 device_remove_files(struct device *dev)
 508 {
 509         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 510 }
 511
 512 /* this is a simple abstraction for device_register that sets the
 513  * correct bus type and adds the bus specific files */
 514 int
 515 ccw_device_register(struct ccw_device *cdev)
 516 {
 517         struct device *dev = &cdev->dev;
 518         int ret;
 519
 520         dev->bus = &ccw_bus_type;
 521
 522         if ((ret = device_add(dev)))
 523                 return ret;
 524
 525         set_bit(1, &cdev->private->registered);
 526         if ((ret = device_add_files(dev))) {
 527                 if (test_and_clear_bit(1, &cdev->private->registered))
 528                         device_del(dev);
 529         }
 530         return ret;
 531 }
 532
 533 struct match_data {
 534         unsigned int devno;
 535         unsigned int ssid;
 536         struct ccw_device * sibling;
 537 };
 538
 539 static int
 540 match_devno(struct device * dev, void * data)
 541 {
 542         struct match_data * d = (struct match_data *)data;
 543         struct ccw_device * cdev;
 544
 545         cdev = to_ccwdev(dev);
 546         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 547             (cdev->private->devno == d->devno) &&
 548             (cdev->private->ssid == d->ssid) &&
 549             (cdev != d->sibling)) {
 550                 cdev->private->state = DEV_STATE_NOT_OPER;
 551                 return 1;
 552         }
 553         return 0;
 554 }
 555
 556 static struct ccw_device *
 557 get_disc_ccwdev_by_devno(unsigned int devno, unsigned int ssid,
 558                          struct ccw_device *sibling)
 559 {
 560         struct device *dev;
 561         struct match_data data = {
 562                 .devno   = devno,
 563                 .ssid    = ssid,
 564                 .sibling = sibling,
 565         };
 566
 567         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 568
 569         return dev ? to_ccwdev(dev) : NULL;
 570 }
 571
 572 static void
 573 ccw_device_add_changed(void *data)
 574 {
 575
 576         struct ccw_device *cdev;
 577
 578         cdev = (struct ccw_device *)data;
 579         if (device_add(&cdev->dev)) {
 580                 put_device(&cdev->dev);
 581                 return;
 582         }
 583         set_bit(1, &cdev->private->registered);
 584         if (device_add_files(&cdev->dev)) {
 585                 if (test_and_clear_bit(1, &cdev->private->registered))
 586                         device_unregister(&cdev->dev);
 587         }
 588 }
 589
 590 extern int css_get_ssd_info(struct subchannel *sch);
 591
 592 void
 593 ccw_device_do_unreg_rereg(void *data)
 594 {
 595         struct ccw_device *cdev;
 596         struct subchannel *sch;
 597         int need_rename;
 598
 599         cdev = (struct ccw_device *)data;
 600         sch = to_subchannel(cdev->dev.parent);
 601         if (cdev->private->devno != sch->schib.pmcw.dev) {
 602                 /*
 603                  * The device number has changed. This is usually only when
 604                  * a device has been detached under VM and then re-appeared
 605                  * on another subchannel because of a different attachment
 606                  * order than before. Ideally, we should should just switch
 607                  * subchannels, but unfortunately, this is not possible with
 608                  * the current implementation.
 609                  * Instead, we search for the old subchannel for this device
 610                  * number and deregister so there are no collisions with the
 611                  * newly registered ccw_device.
 612                  * FIXME: Find another solution so the block layer doesn't
 613                  *        get possibly sick...
 614                  */
 615                 struct ccw_device *other_cdev;
 616
 617                 need_rename = 1;
 618                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 619                                                       sch->schid.ssid, cdev);
 620                 if (other_cdev) {
 621                         struct subchannel *other_sch;
 622
 623                         other_sch = to_subchannel(other_cdev->dev.parent);
 624                         if (get_device(&other_sch->dev)) {
 625                                 stsch(other_sch->schid, &other_sch->schib);
 626                                 if (other_sch->schib.pmcw.dnv) {
 627                                         other_sch->schib.pmcw.intparm = 0;
 628                                         cio_modify(other_sch);
 629                                 }
 630                                 device_unregister(&other_sch->dev);
 631                         }
 632                 }
 633                 /* Update ssd info here. */
 634                 css_get_ssd_info(sch);
 635                 cdev->private->devno = sch->schib.pmcw.dev;
 636         } else
 637                 need_rename = 0;
 638         device_remove_files(&cdev->dev);
 639         if (test_and_clear_bit(1, &cdev->private->registered))
 640                 device_del(&cdev->dev);
 641         if (need_rename)
 642                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 643                           sch->schid.ssid, sch->schib.pmcw.dev);
 644         PREPARE_WORK(&cdev->private->kick_work,
 645                      ccw_device_add_changed, (void *)cdev);
 646         queue_work(ccw_device_work, &cdev->private->kick_work);
 647 }
 648
 649 static void
 650 ccw_device_release(struct device *dev)
 651 {
 652         struct ccw_device *cdev;
 653
 654         cdev = to_ccwdev(dev);
 655         kfree(cdev->private);
 656         kfree(cdev);
 657 }
 658
 659 /*
 660  * Register recognized device.
 661  */
 662 static void
 663 io_subchannel_register(void *data)
 664 {
 665         struct ccw_device *cdev;
 666         struct subchannel *sch;
 667         int ret;
 668         unsigned long flags;
 669
 670         cdev = (struct ccw_device *) data;
 671         sch = to_subchannel(cdev->dev.parent);
 672
 673         if (klist_node_attached(&cdev->dev.knode_parent)) {
 674                 bus_rescan_devices(&ccw_bus_type);
 675                 goto out;
 676         }
 677         /* make it known to the system */
 678         ret = ccw_device_register(cdev);
 679         if (ret) {
 680                 printk (KERN_WARNING "%s: could not register %s\n",
 681                         __func__, cdev->dev.bus_id);
 682                 put_device(&cdev->dev);
 683                 spin_lock_irqsave(&sch->lock, flags);
 684                 sch->dev.driver_data = NULL;
 685                 spin_unlock_irqrestore(&sch->lock, flags);
 686                 kfree (cdev->private);
 687                 kfree (cdev);
 688                 put_device(&sch->dev);
 689                 if (atomic_dec_and_test(&ccw_device_init_count))
 690                         wake_up(&ccw_device_init_wq);
 691                 return;
 692         }
 693
 694         ret = subchannel_add_files(cdev->dev.parent);
 695         if (ret)
 696                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 697                        __func__, sch->dev.bus_id);
 698         put_device(&cdev->dev);
 699 out:
 700         cdev->private->flags.recog_done = 1;
 701         put_device(&sch->dev);
 702         wake_up(&cdev->private->wait_q);
 703         if (atomic_dec_and_test(&ccw_device_init_count))
 704                 wake_up(&ccw_device_init_wq);
 705 }
 706
 707 void
 708 ccw_device_call_sch_unregister(void *data)
 709 {
 710         struct ccw_device *cdev = data;
 711         struct subchannel *sch;
 712
 713         sch = to_subchannel(cdev->dev.parent);
 714         device_unregister(&sch->dev);
 715         /* Reset intparm to zeroes. */
 716         sch->schib.pmcw.intparm = 0;
 717         cio_modify(sch);
 718         put_device(&cdev->dev);
 719         put_device(&sch->dev);
 720 }
 721
 722 /*
 723  * subchannel recognition done. Called from the state machine.
 724  */
 725 void
 726 io_subchannel_recog_done(struct ccw_device *cdev)
 727 {
 728         struct subchannel *sch;
 729
 730         if (css_init_done == 0) {
 731                 cdev->private->flags.recog_done = 1;
 732                 return;
 733         }
 734         switch (cdev->private->state) {
 735         case DEV_STATE_NOT_OPER:
 736                 cdev->private->flags.recog_done = 1;
 737                 /* Remove device found not operational. */
 738                 if (!get_device(&cdev->dev))
 739                         break;
 740                 sch = to_subchannel(cdev->dev.parent);
 741                 PREPARE_WORK(&cdev->private->kick_work,
 742                              ccw_device_call_sch_unregister, (void *) cdev);
 743                 queue_work(slow_path_wq, &cdev->private->kick_work);
 744                 if (atomic_dec_and_test(&ccw_device_init_count))
 745                         wake_up(&ccw_device_init_wq);
 746                 break;
 747         case DEV_STATE_BOXED:
 748                 /* Device did not respond in time. */
 749         case DEV_STATE_OFFLINE:
 750                 /*
 751                  * We can't register the device in interrupt context so
 752                  * we schedule a work item.
 753                  */
 754                 if (!get_device(&cdev->dev))
 755                         break;
 756                 PREPARE_WORK(&cdev->private->kick_work,
 757                              io_subchannel_register, (void *) cdev);
 758                 queue_work(slow_path_wq, &cdev->private->kick_work);
 759                 break;
 760         }
 761 }
 762
 763 static int
 764 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 765 {
 766         int rc;
 767         struct ccw_device_private *priv;
 768
 769         sch->dev.driver_data = cdev;
 770         sch->driver = &io_subchannel_driver;
 771         cdev->ccwlock = &sch->lock;
 772
 773         /* Init private data. */
 774         priv = cdev->private;
 775         priv->devno = sch->schib.pmcw.dev;
 776         priv->ssid = sch->schid.ssid;
 777         priv->sch_no = sch->schid.sch_no;
 778         priv->state = DEV_STATE_NOT_OPER;
 779         INIT_LIST_HEAD(&priv->cmb_list);
 780         init_waitqueue_head(&priv->wait_q);
 781         init_timer(&priv->timer);
 782
 783         /* Set an initial name for the device. */
 784         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 785                   sch->schid.ssid, sch->schib.pmcw.dev);
 786
 787         /* Increase counter of devices currently in recognition. */
 788         atomic_inc(&ccw_device_init_count);
 789
 790         /* Start async. device sensing. */
 791         spin_lock_irq(&sch->lock);
 792         rc = ccw_device_recognition(cdev);
 793         spin_unlock_irq(&sch->lock);
 794         if (rc) {
 795                 if (atomic_dec_and_test(&ccw_device_init_count))
 796                         wake_up(&ccw_device_init_wq);
 797         }
 798         return rc;
 799 }
 800
 801 static int
 802 io_subchannel_probe (struct subchannel *sch)
 803 {
 804         struct ccw_device *cdev;
 805         int rc;
 806         unsigned long flags;
 807
 808         if (sch->dev.driver_data) {
 809                 /*
 810                  * This subchannel already has an associated ccw_device.
 811                  * Register it and exit. This happens for all early
 812                  * device, e.g. the console.
 813                  */
 814                 cdev = sch->dev.driver_data;
 815                 device_initialize(&cdev->dev);
 816                 ccw_device_register(cdev);
 817                 subchannel_add_files(&sch->dev);
 818                 /*
 819                  * Check if the device is already online. If it is
 820                  * the reference count needs to be corrected
 821                  * (see ccw_device_online and css_init_done for the
 822                  * ugly details).
 823                  */
 824                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 825                     cdev->private->state != DEV_STATE_OFFLINE &&
 826                     cdev->private->state != DEV_STATE_BOXED)
 827                         get_device(&cdev->dev);
 828                 return 0;
 829         }
 830         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 831         if (!cdev)
 832                 return -ENOMEM;
 833         memset(cdev, 0, sizeof(struct ccw_device));
 834         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 835                                 GFP_KERNEL | GFP_DMA);
 836         if (!cdev->private) {
 837                 kfree(cdev);
 838                 return -ENOMEM;
 839         }
 840         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 841         atomic_set(&cdev->private->onoff, 0);
 842         cdev->dev = (struct device) {
 843                 .parent = &sch->dev,
 844                 .release = ccw_device_release,
 845         };
 846         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 847         /* Do first half of device_register. */
 848         device_initialize(&cdev->dev);
 849
 850         if (!get_device(&sch->dev)) {
 851                 if (cdev->dev.release)
 852                         cdev->dev.release(&cdev->dev);
 853                 return -ENODEV;
 854         }
 855
 856         rc = io_subchannel_recog(cdev, sch);
 857         if (rc) {
 858                 spin_lock_irqsave(&sch->lock, flags);
 859                 sch->dev.driver_data = NULL;
 860                 spin_unlock_irqrestore(&sch->lock, flags);
 861                 if (cdev->dev.release)
 862                         cdev->dev.release(&cdev->dev);
 863         }
 864
 865         return rc;
 866 }
 867
 868 static void
 869 ccw_device_unregister(void *data)
 870 {
 871         struct ccw_device *cdev;
 872
 873         cdev = (struct ccw_device *)data;
 874         if (test_and_clear_bit(1, &cdev->private->registered))
 875                 device_unregister(&cdev->dev);
 876         put_device(&cdev->dev);
 877 }
 878
 879 static int
 880 io_subchannel_remove (struct subchannel *sch)
 881 {
 882         struct ccw_device *cdev;
 883         unsigned long flags;
 884
 885         if (!sch->dev.driver_data)
 886                 return 0;
 887         cdev = sch->dev.driver_data;
 888         /* Set ccw device to not operational and drop reference. */
 889         spin_lock_irqsave(cdev->ccwlock, flags);
 890         sch->dev.driver_data = NULL;
 891         cdev->private->state = DEV_STATE_NOT_OPER;
 892         spin_unlock_irqrestore(cdev->ccwlock, flags);
 893         /*
 894          * Put unregistration on workqueue to avoid livelocks on the css bus
 895          * semaphore.
 896          */
 897         if (get_device(&cdev->dev)) {
 898                 PREPARE_WORK(&cdev->private->kick_work,
 899                              ccw_device_unregister, (void *) cdev);
 900                 queue_work(ccw_device_work, &cdev->private->kick_work);
 901         }
 902         return 0;
 903 }
 904
 905 static int
 906 io_subchannel_notify(struct device *dev, int event)
 907 {
 908         struct ccw_device *cdev;
 909
 910         cdev = dev->driver_data;
 911         if (!cdev)
 912                 return 0;
 913         if (!cdev->drv)
 914                 return 0;
 915         if (!cdev->online)
 916                 return 0;
 917         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 918 }
 919
 920 static void
 921 io_subchannel_verify(struct device *dev)
 922 {
 923         struct ccw_device *cdev;
 924
 925         cdev = dev->driver_data;
 926         if (cdev)
 927                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 928 }
 929
 930 static void
 931 io_subchannel_ioterm(struct device *dev)
 932 {
 933         struct ccw_device *cdev;
 934
 935         cdev = dev->driver_data;
 936         if (!cdev)
 937                 return;
 938         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 939         if (cdev->handler)
 940                 cdev->handler(cdev, cdev->private->intparm,
 941                               ERR_PTR(-EIO));
 942 }
 943
 944 static void
 945 io_subchannel_shutdown(struct subchannel *sch)
 946 {
 947         struct ccw_device *cdev;
 948         int ret;
 949
 950         cdev = sch->dev.driver_data;
 951
 952         if (cio_is_console(sch->schid))
 953                 return;
 954         if (!sch->schib.pmcw.ena)
 955                 /* Nothing to do. */
 956                 return;
 957         ret = cio_disable_subchannel(sch);
 958         if (ret != -EBUSY)
 959                 /* Subchannel is disabled, we're done. */
 960                 return;
 961         cdev->private->state = DEV_STATE_QUIESCE;
 962         if (cdev->handler)
 963                 cdev->handler(cdev, cdev->private->intparm,
 964                               ERR_PTR(-EIO));
 965         ret = ccw_device_cancel_halt_clear(cdev);
 966         if (ret == -EBUSY) {
 967                 ccw_device_set_timeout(cdev, HZ/10);
 968                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 969         }
 970         cio_disable_subchannel(sch);
 971 }
 972
 973 #ifdef CONFIG_CCW_CONSOLE
 974 static struct ccw_device console_cdev;
 975 static struct ccw_device_private console_private;
 976 static int console_cdev_in_use;
 977
 978 static int
 979 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 980 {
 981         int rc;
 982
 983         /* Initialize the ccw_device structure. */
 984         cdev->dev = (struct device) {
 985                 .parent = &sch->dev,
 986         };
 987         rc = io_subchannel_recog(cdev, sch);
 988         if (rc)
 989                 return rc;
 990
 991         /* Now wait for the async. recognition to come to an end. */
 992         spin_lock_irq(cdev->ccwlock);
 993         while (!dev_fsm_final_state(cdev))
 994                 wait_cons_dev();
 995         rc = -EIO;
 996         if (cdev->private->state != DEV_STATE_OFFLINE)
 997                 goto out_unlock;
 998         ccw_device_online(cdev);
 999         while (!dev_fsm_final_state(cdev))
1000                 wait_cons_dev();
1001         if (cdev->private->state != DEV_STATE_ONLINE)
1002                 goto out_unlock;
1003         rc = 0;
1004 out_unlock:
1005         spin_unlock_irq(cdev->ccwlock);
1006         return 0;
1007 }
1008
1009 struct ccw_device *
1010 ccw_device_probe_console(void)
1011 {
1012         struct subchannel *sch;
1013         int ret;
1014
1015         if (xchg(&console_cdev_in_use, 1) != 0)
1016                 return NULL;
1017         sch = cio_probe_console();
1018         if (IS_ERR(sch)) {
1019                 console_cdev_in_use = 0;
1020                 return (void *) sch;
1021         }
1022         memset(&console_cdev, 0, sizeof(struct ccw_device));
1023         memset(&console_private, 0, sizeof(struct ccw_device_private));
1024         console_cdev.private = &console_private;
1025         ret = ccw_device_console_enable(&console_cdev, sch);
1026         if (ret) {
1027                 cio_release_console();
1028                 console_cdev_in_use = 0;
1029                 return ERR_PTR(ret);
1030         }
1031         console_cdev.online = 1;
1032         return &console_cdev;
1033 }
1034 #endif
1035
1036 /*
1037  * get ccw_device matching the busid, but only if owned by cdrv
1038  */
1039 static int
1040 __ccwdev_check_busid(struct device *dev, void *id)
1041 {
1042         char *bus_id;
1043
1044         bus_id = (char *)id;
1045
1046         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1047 }
1048
1049
1050 struct ccw_device *
1051 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1052 {
1053         struct device *dev;
1054         struct device_driver *drv;
1055
1056         drv = get_driver(&cdrv->driver);
1057         if (!drv)
1058                 return NULL;
1059
1060         dev = driver_find_device(drv, NULL, (void *)bus_id,
1061                                  __ccwdev_check_busid);
1062         put_driver(drv);
1063
1064         return dev ? to_ccwdev(dev) : 0;
1065 }
1066
1067 /************************** device driver handling ************************/
1068
1069 /* This is the implementation of the ccw_driver class. The probe, remove
1070  * and release methods are initially very similar to the device_driver
1071  * implementations, with the difference that they have ccw_device
1072  * arguments.
1073  *
1074  * A ccw driver also contains the information that is needed for
1075  * device matching.
1076  */
1077 static int
1078 ccw_device_probe (struct device *dev)
1079 {
1080         struct ccw_device *cdev = to_ccwdev(dev);
1081         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1082         int ret;
1083
1084         cdev->drv = cdrv; /* to let the driver call _set_online */
1085
1086         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1087
1088         if (ret) {
1089                 cdev->drv = 0;
1090                 return ret;
1091         }
1092
1093         return 0;
1094 }
1095
1096 static int
1097 ccw_device_remove (struct device *dev)
1098 {
1099         struct ccw_device *cdev = to_ccwdev(dev);
1100         struct ccw_driver *cdrv = cdev->drv;
1101         int ret;
1102
1103         pr_debug("removing device %s\n", cdev->dev.bus_id);
1104         if (cdrv->remove)
1105                 cdrv->remove(cdev);
1106         if (cdev->online) {
1107                 cdev->online = 0;
1108                 spin_lock_irq(cdev->ccwlock);
1109                 ret = ccw_device_offline(cdev);
1110                 spin_unlock_irq(cdev->ccwlock);
1111                 if (ret == 0)
1112                         wait_event(cdev->private->wait_q,
1113                                    dev_fsm_final_state(cdev));
1114                 else
1115                         //FIXME: we can't fail!
1116                         pr_debug("ccw_device_offline returned %d, device %s\n",
1117                                  ret, cdev->dev.bus_id);
1118         }
1119         ccw_device_set_timeout(cdev, 0);
1120         cdev->drv = 0;
1121         return 0;
1122 }
1123
1124 struct bus_type ccw_bus_type = {
1125         .name   = "ccw",
1126         .match  = ccw_bus_match,
1127         .uevent = ccw_uevent,
1128         .probe  = ccw_device_probe,
1129         .remove = ccw_device_remove,
1130 };
1131
1132 int
1133 ccw_driver_register (struct ccw_driver *cdriver)
1134 {
1135         struct device_driver *drv = &cdriver->driver;
1136
1137         drv->bus = &ccw_bus_type;
1138         drv->name = cdriver->name;
1139
1140         return driver_register(drv);
1141 }
1142
1143 void
1144 ccw_driver_unregister (struct ccw_driver *cdriver)
1145 {
1146         driver_unregister(&cdriver->driver);
1147 }
1148
1149 /* Helper func for qdio. */
1150 struct subchannel_id
1151 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1152 {
1153         struct subchannel *sch;
1154
1155         sch = to_subchannel(cdev->dev.parent);
1156         return sch->schid;
1157 }
1158
1159 MODULE_LICENSE("GPL");
1160 EXPORT_SYMBOL(ccw_device_set_online);
1161 EXPORT_SYMBOL(ccw_device_set_offline);
1162 EXPORT_SYMBOL(ccw_driver_register);
1163 EXPORT_SYMBOL(ccw_driver_unregister);
1164 EXPORT_SYMBOL(get_ccwdev_by_busid);
1165 EXPORT_SYMBOL(ccw_bus_type);
1166 EXPORT_SYMBOL(ccw_device_work);
1167 EXPORT_SYMBOL(ccw_device_notify_work);
1168 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);