drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   6  *                       IBM Corporation
   7  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/errno.h>
  15 #include <linux/err.h>
  16 #include <linux/slab.h>
  17 #include <linux/list.h>
  18 #include <linux/device.h>
  19 #include <linux/workqueue.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24
  25 #include "cio.h"
  26 #include "css.h"
  27 #include "device.h"
  28 #include "ioasm.h"
  29
  30 /******************* bus type handling ***********************/
  31
  32 /* The Linux driver model distinguishes between a bus type and
  33  * the bus itself. Of course we only have one channel
  34  * subsystem driver and one channel system per machine, but
  35  * we still use the abstraction. T.R. says it's a good idea. */
  36 static int
  37 ccw_bus_match (struct device * dev, struct device_driver * drv)
  38 {
  39         struct ccw_device *cdev = to_ccwdev(dev);
  40         struct ccw_driver *cdrv = to_ccwdrv(drv);
  41         const struct ccw_device_id *ids = cdrv->ids, *found;
  42
  43         if (!ids)
  44                 return 0;
  45
  46         found = ccw_device_id_match(ids, &cdev->id);
  47         if (!found)
  48                 return 0;
  49
  50         cdev->id.driver_info = found->driver_info;
  51
  52         return 1;
  53 }
  54
  55 /* Store modalias string delimited by prefix/suffix string into buffer with
  56  * specified size. Return length of resulting string (excluding trailing '\0')
  57  * even if string doesn't fit buffer (snprintf semantics). */
  58 static int snprint_alias(char *buf, size_t size, const char *prefix,
  59                          struct ccw_device_id *id, const char *suffix)
  60 {
  61         int len;
  62
  63         len = snprintf(buf, size, "%sccw:t%04Xm%02X", prefix, id->cu_type,
  64                        id->cu_model);
  65         if (len > size)
  66                 return len;
  67         buf += len;
  68         size -= len;
  69
  70         if (id->dev_type != 0)
  71                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  72                                 id->dev_model, suffix);
  73         else
  74                 len += snprintf(buf, size, "dtdm%s", suffix);
  75
  76         return len;
  77 }
  78
  79 /* Set up environment variables for ccw device uevent. Return 0 on success,
  80  * non-zero otherwise. */
  81 static int ccw_uevent(struct device *dev, char **envp, int num_envp,
  82                       char *buffer, int buffer_size)
  83 {
  84         struct ccw_device *cdev = to_ccwdev(dev);
  85         struct ccw_device_id *id = &(cdev->id);
  86         int i = 0;
  87         int len;
  88
  89         /* CU_TYPE= */
  90         len = snprintf(buffer, buffer_size, "CU_TYPE=%04X", id->cu_type) + 1;
  91         if (len > buffer_size || i >= num_envp)
  92                 return -ENOMEM;
  93         envp[i++] = buffer;
  94         buffer += len;
  95         buffer_size -= len;
  96
  97         /* CU_MODEL= */
  98         len = snprintf(buffer, buffer_size, "CU_MODEL=%02X", id->cu_model) + 1;
  99         if (len > buffer_size || i >= num_envp)
 100                 return -ENOMEM;
 101         envp[i++] = buffer;
 102         buffer += len;
 103         buffer_size -= len;
 104
 105         /* The next two can be zero, that's ok for us */
 106         /* DEV_TYPE= */
 107         len = snprintf(buffer, buffer_size, "DEV_TYPE=%04X", id->dev_type) + 1;
 108         if (len > buffer_size || i >= num_envp)
 109                 return -ENOMEM;
 110         envp[i++] = buffer;
 111         buffer += len;
 112         buffer_size -= len;
 113
 114         /* DEV_MODEL= */
 115         len = snprintf(buffer, buffer_size, "DEV_MODEL=%02X",
 116                         (unsigned char) id->dev_model) + 1;
 117         if (len > buffer_size || i >= num_envp)
 118                 return -ENOMEM;
 119         envp[i++] = buffer;
 120         buffer += len;
 121         buffer_size -= len;
 122
 123         /* MODALIAS=  */
 124         len = snprint_alias(buffer, buffer_size, "MODALIAS=", id, "") + 1;
 125         if (len > buffer_size || i >= num_envp)
 126                 return -ENOMEM;
 127         envp[i++] = buffer;
 128         buffer += len;
 129         buffer_size -= len;
 130
 131         envp[i] = NULL;
 132
 133         return 0;
 134 }
 135
 136 struct bus_type ccw_bus_type;
 137
 138 static int io_subchannel_probe (struct subchannel *);
 139 static int io_subchannel_remove (struct subchannel *);
 140 void io_subchannel_irq (struct device *);
 141 static int io_subchannel_notify(struct device *, int);
 142 static void io_subchannel_verify(struct device *);
 143 static void io_subchannel_ioterm(struct device *);
 144 static void io_subchannel_shutdown(struct subchannel *);
 145
 146 struct css_driver io_subchannel_driver = {
 147         .subchannel_type = SUBCHANNEL_TYPE_IO,
 148         .drv = {
 149                 .name = "io_subchannel",
 150                 .bus  = &css_bus_type,
 151         },
 152         .irq = io_subchannel_irq,
 153         .notify = io_subchannel_notify,
 154         .verify = io_subchannel_verify,
 155         .termination = io_subchannel_ioterm,
 156         .probe = io_subchannel_probe,
 157         .remove = io_subchannel_remove,
 158         .shutdown = io_subchannel_shutdown,
 159 };
 160
 161 struct workqueue_struct *ccw_device_work;
 162 struct workqueue_struct *ccw_device_notify_work;
 163 wait_queue_head_t ccw_device_init_wq;
 164 atomic_t ccw_device_init_count;
 165
 166 static int __init
 167 init_ccw_bus_type (void)
 168 {
 169         int ret;
 170
 171         init_waitqueue_head(&ccw_device_init_wq);
 172         atomic_set(&ccw_device_init_count, 0);
 173
 174         ccw_device_work = create_singlethread_workqueue("cio");
 175         if (!ccw_device_work)
 176                 return -ENOMEM; /* FIXME: better errno ? */
 177         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 178         if (!ccw_device_notify_work) {
 179                 ret = -ENOMEM; /* FIXME: better errno ? */
 180                 goto out_err;
 181         }
 182         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 183         if (!slow_path_wq) {
 184                 ret = -ENOMEM; /* FIXME: better errno ? */
 185                 goto out_err;
 186         }
 187         if ((ret = bus_register (&ccw_bus_type)))
 188                 goto out_err;
 189
 190         if ((ret = driver_register(&io_subchannel_driver.drv)))
 191                 goto out_err;
 192
 193         wait_event(ccw_device_init_wq,
 194                    atomic_read(&ccw_device_init_count) == 0);
 195         flush_workqueue(ccw_device_work);
 196         return 0;
 197 out_err:
 198         if (ccw_device_work)
 199                 destroy_workqueue(ccw_device_work);
 200         if (ccw_device_notify_work)
 201                 destroy_workqueue(ccw_device_notify_work);
 202         if (slow_path_wq)
 203                 destroy_workqueue(slow_path_wq);
 204         return ret;
 205 }
 206
 207 static void __exit
 208 cleanup_ccw_bus_type (void)
 209 {
 210         driver_unregister(&io_subchannel_driver.drv);
 211         bus_unregister(&ccw_bus_type);
 212         destroy_workqueue(ccw_device_notify_work);
 213         destroy_workqueue(ccw_device_work);
 214 }
 215
 216 subsys_initcall(init_ccw_bus_type);
 217 module_exit(cleanup_ccw_bus_type);
 218
 219 /************************ device handling **************************/
 220
 221 /*
 222  * A ccw_device has some interfaces in sysfs in addition to the
 223  * standard ones.
 224  * The following entries are designed to export the information which
 225  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 226  * are obvious, so they don't have an entry :)
 227  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 228  */
 229 static ssize_t
 230 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 231 {
 232         struct subchannel *sch = to_subchannel(dev);
 233         struct ssd_info *ssd = &sch->ssd_info;
 234         ssize_t ret = 0;
 235         int chp;
 236
 237         for (chp = 0; chp < 8; chp++)
 238                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 239
 240         ret += sprintf (buf+ret, "\n");
 241         return min((ssize_t)PAGE_SIZE, ret);
 242 }
 243
 244 static ssize_t
 245 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 246 {
 247         struct subchannel *sch = to_subchannel(dev);
 248         struct pmcw *pmcw = &sch->schib.pmcw;
 249
 250         return sprintf (buf, "%02x %02x %02x\n",
 251                         pmcw->pim, pmcw->pam, pmcw->pom);
 252 }
 253
 254 static ssize_t
 255 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 256 {
 257         struct ccw_device *cdev = to_ccwdev(dev);
 258         struct ccw_device_id *id = &(cdev->id);
 259
 260         if (id->dev_type != 0)
 261                 return sprintf(buf, "%04x/%02x\n",
 262                                 id->dev_type, id->dev_model);
 263         else
 264                 return sprintf(buf, "n/a\n");
 265 }
 266
 267 static ssize_t
 268 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 269 {
 270         struct ccw_device *cdev = to_ccwdev(dev);
 271         struct ccw_device_id *id = &(cdev->id);
 272
 273         return sprintf(buf, "%04x/%02x\n",
 274                        id->cu_type, id->cu_model);
 275 }
 276
 277 static ssize_t
 278 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 279 {
 280         struct ccw_device *cdev = to_ccwdev(dev);
 281         struct ccw_device_id *id = &(cdev->id);
 282         int len;
 283
 284         len = snprint_alias(buf, PAGE_SIZE, "", id, "\n") + 1;
 285
 286         return len > PAGE_SIZE ? PAGE_SIZE : len;
 287 }
 288
 289 static ssize_t
 290 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 291 {
 292         struct ccw_device *cdev = to_ccwdev(dev);
 293
 294         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 295 }
 296
 297 static void
 298 ccw_device_remove_disconnected(struct ccw_device *cdev)
 299 {
 300         struct subchannel *sch;
 301         /*
 302          * Forced offline in disconnected state means
 303          * 'throw away device'.
 304          */
 305         sch = to_subchannel(cdev->dev.parent);
 306         css_sch_device_unregister(sch);
 307         /* Reset intparm to zeroes. */
 308         sch->schib.pmcw.intparm = 0;
 309         cio_modify(sch);
 310         put_device(&sch->dev);
 311 }
 312
 313 int
 314 ccw_device_set_offline(struct ccw_device *cdev)
 315 {
 316         int ret;
 317
 318         if (!cdev)
 319                 return -ENODEV;
 320         if (!cdev->online || !cdev->drv)
 321                 return -EINVAL;
 322
 323         if (cdev->drv->set_offline) {
 324                 ret = cdev->drv->set_offline(cdev);
 325                 if (ret != 0)
 326                         return ret;
 327         }
 328         cdev->online = 0;
 329         spin_lock_irq(cdev->ccwlock);
 330         ret = ccw_device_offline(cdev);
 331         if (ret == -ENODEV) {
 332                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 333                         cdev->private->state = DEV_STATE_OFFLINE;
 334                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 335                 }
 336                 spin_unlock_irq(cdev->ccwlock);
 337                 return ret;
 338         }
 339         spin_unlock_irq(cdev->ccwlock);
 340         if (ret == 0)
 341                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 342         else {
 343                 pr_debug("ccw_device_offline returned %d, device %s\n",
 344                          ret, cdev->dev.bus_id);
 345                 cdev->online = 1;
 346         }
 347         return ret;
 348 }
 349
 350 int
 351 ccw_device_set_online(struct ccw_device *cdev)
 352 {
 353         int ret;
 354
 355         if (!cdev)
 356                 return -ENODEV;
 357         if (cdev->online || !cdev->drv)
 358                 return -EINVAL;
 359
 360         spin_lock_irq(cdev->ccwlock);
 361         ret = ccw_device_online(cdev);
 362         spin_unlock_irq(cdev->ccwlock);
 363         if (ret == 0)
 364                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 365         else {
 366                 pr_debug("ccw_device_online returned %d, device %s\n",
 367                          ret, cdev->dev.bus_id);
 368                 return ret;
 369         }
 370         if (cdev->private->state != DEV_STATE_ONLINE)
 371                 return -ENODEV;
 372         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 373                 cdev->online = 1;
 374                 return 0;
 375         }
 376         spin_lock_irq(cdev->ccwlock);
 377         ret = ccw_device_offline(cdev);
 378         spin_unlock_irq(cdev->ccwlock);
 379         if (ret == 0)
 380                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 381         else
 382                 pr_debug("ccw_device_offline returned %d, device %s\n",
 383                          ret, cdev->dev.bus_id);
 384         return (ret == 0) ? -ENODEV : ret;
 385 }
 386
 387 static ssize_t
 388 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 389 {
 390         struct ccw_device *cdev = to_ccwdev(dev);
 391         int i, force, ret;
 392         char *tmp;
 393
 394         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 395                 return -EAGAIN;
 396
 397         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 398                 atomic_set(&cdev->private->onoff, 0);
 399                 return -EINVAL;
 400         }
 401         if (!strncmp(buf, "force\n", count)) {
 402                 force = 1;
 403                 i = 1;
 404         } else {
 405                 force = 0;
 406                 i = simple_strtoul(buf, &tmp, 16);
 407         }
 408         if (i == 1) {
 409                 /* Do device recognition, if needed. */
 410                 if (cdev->id.cu_type == 0) {
 411                         ret = ccw_device_recognition(cdev);
 412                         if (ret) {
 413                                 printk(KERN_WARNING"Couldn't start recognition "
 414                                        "for device %s (ret=%d)\n",
 415                                        cdev->dev.bus_id, ret);
 416                                 goto out;
 417                         }
 418                         wait_event(cdev->private->wait_q,
 419                                    cdev->private->flags.recog_done);
 420                 }
 421                 if (cdev->drv && cdev->drv->set_online)
 422                         ccw_device_set_online(cdev);
 423         } else if (i == 0) {
 424                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 425                         ccw_device_remove_disconnected(cdev);
 426                 else if (cdev->drv && cdev->drv->set_offline)
 427                         ccw_device_set_offline(cdev);
 428         }
 429         if (force && cdev->private->state == DEV_STATE_BOXED) {
 430                 ret = ccw_device_stlck(cdev);
 431                 if (ret) {
 432                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 433                                "returned %d!\n", cdev->dev.bus_id, ret);
 434                         goto out;
 435                 }
 436                 /* Do device recognition, if needed. */
 437                 if (cdev->id.cu_type == 0) {
 438                         cdev->private->state = DEV_STATE_NOT_OPER;
 439                         ret = ccw_device_recognition(cdev);
 440                         if (ret) {
 441                                 printk(KERN_WARNING"Couldn't start recognition "
 442                                        "for device %s (ret=%d)\n",
 443                                        cdev->dev.bus_id, ret);
 444                                 goto out;
 445                         }
 446                         wait_event(cdev->private->wait_q,
 447                                    cdev->private->flags.recog_done);
 448                 }
 449                 if (cdev->drv && cdev->drv->set_online)
 450                         ccw_device_set_online(cdev);
 451         }
 452         out:
 453         if (cdev->drv)
 454                 module_put(cdev->drv->owner);
 455         atomic_set(&cdev->private->onoff, 0);
 456         return count;
 457 }
 458
 459 static ssize_t
 460 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 461 {
 462         struct ccw_device *cdev = to_ccwdev(dev);
 463         struct subchannel *sch;
 464
 465         switch (cdev->private->state) {
 466         case DEV_STATE_BOXED:
 467                 return sprintf(buf, "boxed\n");
 468         case DEV_STATE_DISCONNECTED:
 469         case DEV_STATE_DISCONNECTED_SENSE_ID:
 470         case DEV_STATE_NOT_OPER:
 471                 sch = to_subchannel(dev->parent);
 472                 if (!sch->lpm)
 473                         return sprintf(buf, "no path\n");
 474                 else
 475                         return sprintf(buf, "no device\n");
 476         default:
 477                 /* All other states considered fine. */
 478                 return sprintf(buf, "good\n");
 479         }
 480 }
 481
 482 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 483 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 484 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 485 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 486 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 487 static DEVICE_ATTR(online, 0644, online_show, online_store);
 488 extern struct device_attribute dev_attr_cmb_enable;
 489 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 490
 491 static struct attribute * subch_attrs[] = {
 492         &dev_attr_chpids.attr,
 493         &dev_attr_pimpampom.attr,
 494         NULL,
 495 };
 496
 497 static struct attribute_group subch_attr_group = {
 498         .attrs = subch_attrs,
 499 };
 500
 501 static inline int
 502 subchannel_add_files (struct device *dev)
 503 {
 504         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 505 }
 506
 507 static struct attribute * ccwdev_attrs[] = {
 508         &dev_attr_devtype.attr,
 509         &dev_attr_cutype.attr,
 510         &dev_attr_modalias.attr,
 511         &dev_attr_online.attr,
 512         &dev_attr_cmb_enable.attr,
 513         &dev_attr_availability.attr,
 514         NULL,
 515 };
 516
 517 static struct attribute_group ccwdev_attr_group = {
 518         .attrs = ccwdev_attrs,
 519 };
 520
 521 static inline int
 522 device_add_files (struct device *dev)
 523 {
 524         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 525 }
 526
 527 static inline void
 528 device_remove_files(struct device *dev)
 529 {
 530         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 531 }
 532
 533 /* this is a simple abstraction for device_register that sets the
 534  * correct bus type and adds the bus specific files */
 535 int
 536 ccw_device_register(struct ccw_device *cdev)
 537 {
 538         struct device *dev = &cdev->dev;
 539         int ret;
 540
 541         dev->bus = &ccw_bus_type;
 542
 543         if ((ret = device_add(dev)))
 544                 return ret;
 545
 546         set_bit(1, &cdev->private->registered);
 547         if ((ret = device_add_files(dev))) {
 548                 if (test_and_clear_bit(1, &cdev->private->registered))
 549                         device_del(dev);
 550         }
 551         return ret;
 552 }
 553
 554 struct match_data {
 555         struct ccw_dev_id dev_id;
 556         struct ccw_device * sibling;
 557 };
 558
 559 static int
 560 match_devno(struct device * dev, void * data)
 561 {
 562         struct match_data * d = data;
 563         struct ccw_device * cdev;
 564
 565         cdev = to_ccwdev(dev);
 566         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 567             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 568             (cdev != d->sibling)) {
 569                 cdev->private->state = DEV_STATE_NOT_OPER;
 570                 return 1;
 571         }
 572         return 0;
 573 }
 574
 575 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 576                                                      struct ccw_device *sibling)
 577 {
 578         struct device *dev;
 579         struct match_data data;
 580
 581         data.dev_id = *dev_id;
 582         data.sibling = sibling;
 583         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 584
 585         return dev ? to_ccwdev(dev) : NULL;
 586 }
 587
 588 static void
 589 ccw_device_add_changed(void *data)
 590 {
 591
 592         struct ccw_device *cdev;
 593
 594         cdev = data;
 595         if (device_add(&cdev->dev)) {
 596                 put_device(&cdev->dev);
 597                 return;
 598         }
 599         set_bit(1, &cdev->private->registered);
 600         if (device_add_files(&cdev->dev)) {
 601                 if (test_and_clear_bit(1, &cdev->private->registered))
 602                         device_unregister(&cdev->dev);
 603         }
 604 }
 605
 606 extern int css_get_ssd_info(struct subchannel *sch);
 607
 608 void
 609 ccw_device_do_unreg_rereg(void *data)
 610 {
 611         struct ccw_device *cdev;
 612         struct subchannel *sch;
 613         int need_rename;
 614
 615         cdev = data;
 616         sch = to_subchannel(cdev->dev.parent);
 617         if (cdev->private->dev_id.devno != sch->schib.pmcw.dev) {
 618                 /*
 619                  * The device number has changed. This is usually only when
 620                  * a device has been detached under VM and then re-appeared
 621                  * on another subchannel because of a different attachment
 622                  * order than before. Ideally, we should should just switch
 623                  * subchannels, but unfortunately, this is not possible with
 624                  * the current implementation.
 625                  * Instead, we search for the old subchannel for this device
 626                  * number and deregister so there are no collisions with the
 627                  * newly registered ccw_device.
 628                  * FIXME: Find another solution so the block layer doesn't
 629                  *        get possibly sick...
 630                  */
 631                 struct ccw_device *other_cdev;
 632                 struct ccw_dev_id dev_id;
 633
 634                 need_rename = 1;
 635                 dev_id.devno = sch->schib.pmcw.dev;
 636                 dev_id.ssid = sch->schid.ssid;
 637                 other_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 638                 if (other_cdev) {
 639                         struct subchannel *other_sch;
 640
 641                         other_sch = to_subchannel(other_cdev->dev.parent);
 642                         if (get_device(&other_sch->dev)) {
 643                                 stsch(other_sch->schid, &other_sch->schib);
 644                                 if (other_sch->schib.pmcw.dnv) {
 645                                         other_sch->schib.pmcw.intparm = 0;
 646                                         cio_modify(other_sch);
 647                                 }
 648                                 css_sch_device_unregister(other_sch);
 649                         }
 650                 }
 651                 /* Update ssd info here. */
 652                 css_get_ssd_info(sch);
 653                 cdev->private->dev_id.devno = sch->schib.pmcw.dev;
 654         } else
 655                 need_rename = 0;
 656         device_remove_files(&cdev->dev);
 657         if (test_and_clear_bit(1, &cdev->private->registered))
 658                 device_del(&cdev->dev);
 659         if (need_rename)
 660                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 661                           sch->schid.ssid, sch->schib.pmcw.dev);
 662         PREPARE_WORK(&cdev->private->kick_work,
 663                      ccw_device_add_changed, cdev);
 664         queue_work(ccw_device_work, &cdev->private->kick_work);
 665 }
 666
 667 static void
 668 ccw_device_release(struct device *dev)
 669 {
 670         struct ccw_device *cdev;
 671
 672         cdev = to_ccwdev(dev);
 673         kfree(cdev->private);
 674         kfree(cdev);
 675 }
 676
 677 /*
 678  * Register recognized device.
 679  */
 680 static void
 681 io_subchannel_register(void *data)
 682 {
 683         struct ccw_device *cdev;
 684         struct subchannel *sch;
 685         int ret;
 686         unsigned long flags;
 687
 688         cdev = data;
 689         sch = to_subchannel(cdev->dev.parent);
 690
 691         if (klist_node_attached(&cdev->dev.knode_parent)) {
 692                 bus_rescan_devices(&ccw_bus_type);
 693                 goto out;
 694         }
 695         /* make it known to the system */
 696         ret = ccw_device_register(cdev);
 697         if (ret) {
 698                 printk (KERN_WARNING "%s: could not register %s\n",
 699                         __func__, cdev->dev.bus_id);
 700                 put_device(&cdev->dev);
 701                 spin_lock_irqsave(&sch->lock, flags);
 702                 sch->dev.driver_data = NULL;
 703                 spin_unlock_irqrestore(&sch->lock, flags);
 704                 kfree (cdev->private);
 705                 kfree (cdev);
 706                 put_device(&sch->dev);
 707                 if (atomic_dec_and_test(&ccw_device_init_count))
 708                         wake_up(&ccw_device_init_wq);
 709                 return;
 710         }
 711
 712         ret = subchannel_add_files(cdev->dev.parent);
 713         if (ret)
 714                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 715                        __func__, sch->dev.bus_id);
 716         put_device(&cdev->dev);
 717 out:
 718         cdev->private->flags.recog_done = 1;
 719         put_device(&sch->dev);
 720         wake_up(&cdev->private->wait_q);
 721         if (atomic_dec_and_test(&ccw_device_init_count))
 722                 wake_up(&ccw_device_init_wq);
 723 }
 724
 725 void
 726 ccw_device_call_sch_unregister(void *data)
 727 {
 728         struct ccw_device *cdev = data;
 729         struct subchannel *sch;
 730
 731         sch = to_subchannel(cdev->dev.parent);
 732         css_sch_device_unregister(sch);
 733         /* Reset intparm to zeroes. */
 734         sch->schib.pmcw.intparm = 0;
 735         cio_modify(sch);
 736         put_device(&cdev->dev);
 737         put_device(&sch->dev);
 738 }
 739
 740 /*
 741  * subchannel recognition done. Called from the state machine.
 742  */
 743 void
 744 io_subchannel_recog_done(struct ccw_device *cdev)
 745 {
 746         struct subchannel *sch;
 747
 748         if (css_init_done == 0) {
 749                 cdev->private->flags.recog_done = 1;
 750                 return;
 751         }
 752         switch (cdev->private->state) {
 753         case DEV_STATE_NOT_OPER:
 754                 cdev->private->flags.recog_done = 1;
 755                 /* Remove device found not operational. */
 756                 if (!get_device(&cdev->dev))
 757                         break;
 758                 sch = to_subchannel(cdev->dev.parent);
 759                 PREPARE_WORK(&cdev->private->kick_work,
 760                              ccw_device_call_sch_unregister, cdev);
 761                 queue_work(slow_path_wq, &cdev->private->kick_work);
 762                 if (atomic_dec_and_test(&ccw_device_init_count))
 763                         wake_up(&ccw_device_init_wq);
 764                 break;
 765         case DEV_STATE_BOXED:
 766                 /* Device did not respond in time. */
 767         case DEV_STATE_OFFLINE:
 768                 /*
 769                  * We can't register the device in interrupt context so
 770                  * we schedule a work item.
 771                  */
 772                 if (!get_device(&cdev->dev))
 773                         break;
 774                 PREPARE_WORK(&cdev->private->kick_work,
 775                              io_subchannel_register, cdev);
 776                 queue_work(slow_path_wq, &cdev->private->kick_work);
 777                 break;
 778         }
 779 }
 780
 781 static int
 782 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 783 {
 784         int rc;
 785         struct ccw_device_private *priv;
 786
 787         sch->dev.driver_data = cdev;
 788         sch->driver = &io_subchannel_driver;
 789         cdev->ccwlock = &sch->lock;
 790
 791         /* Init private data. */
 792         priv = cdev->private;
 793         priv->dev_id.devno = sch->schib.pmcw.dev;
 794         priv->dev_id.ssid = sch->schid.ssid;
 795         priv->schid = sch->schid;
 796         priv->state = DEV_STATE_NOT_OPER;
 797         INIT_LIST_HEAD(&priv->cmb_list);
 798         init_waitqueue_head(&priv->wait_q);
 799         init_timer(&priv->timer);
 800
 801         /* Set an initial name for the device. */
 802         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 803                   sch->schid.ssid, sch->schib.pmcw.dev);
 804
 805         /* Increase counter of devices currently in recognition. */
 806         atomic_inc(&ccw_device_init_count);
 807
 808         /* Start async. device sensing. */
 809         spin_lock_irq(&sch->lock);
 810         rc = ccw_device_recognition(cdev);
 811         spin_unlock_irq(&sch->lock);
 812         if (rc) {
 813                 if (atomic_dec_and_test(&ccw_device_init_count))
 814                         wake_up(&ccw_device_init_wq);
 815         }
 816         return rc;
 817 }
 818
 819 static int
 820 io_subchannel_probe (struct subchannel *sch)
 821 {
 822         struct ccw_device *cdev;
 823         int rc;
 824         unsigned long flags;
 825
 826         if (sch->dev.driver_data) {
 827                 /*
 828                  * This subchannel already has an associated ccw_device.
 829                  * Register it and exit. This happens for all early
 830                  * device, e.g. the console.
 831                  */
 832                 cdev = sch->dev.driver_data;
 833                 device_initialize(&cdev->dev);
 834                 ccw_device_register(cdev);
 835                 subchannel_add_files(&sch->dev);
 836                 /*
 837                  * Check if the device is already online. If it is
 838                  * the reference count needs to be corrected
 839                  * (see ccw_device_online and css_init_done for the
 840                  * ugly details).
 841                  */
 842                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 843                     cdev->private->state != DEV_STATE_OFFLINE &&
 844                     cdev->private->state != DEV_STATE_BOXED)
 845                         get_device(&cdev->dev);
 846                 return 0;
 847         }
 848         cdev = kzalloc (sizeof(*cdev), GFP_KERNEL);
 849         if (!cdev)
 850                 return -ENOMEM;
 851         cdev->private = kzalloc(sizeof(struct ccw_device_private),
 852                                 GFP_KERNEL | GFP_DMA);
 853         if (!cdev->private) {
 854                 kfree(cdev);
 855                 return -ENOMEM;
 856         }
 857         atomic_set(&cdev->private->onoff, 0);
 858         cdev->dev.parent = &sch->dev;
 859         cdev->dev.release = ccw_device_release;
 860         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 861         /* Do first half of device_register. */
 862         device_initialize(&cdev->dev);
 863
 864         if (!get_device(&sch->dev)) {
 865                 if (cdev->dev.release)
 866                         cdev->dev.release(&cdev->dev);
 867                 return -ENODEV;
 868         }
 869
 870         rc = io_subchannel_recog(cdev, sch);
 871         if (rc) {
 872                 spin_lock_irqsave(&sch->lock, flags);
 873                 sch->dev.driver_data = NULL;
 874                 spin_unlock_irqrestore(&sch->lock, flags);
 875                 if (cdev->dev.release)
 876                         cdev->dev.release(&cdev->dev);
 877         }
 878
 879         return rc;
 880 }
 881
 882 static void
 883 ccw_device_unregister(void *data)
 884 {
 885         struct ccw_device *cdev;
 886
 887         cdev = (struct ccw_device *)data;
 888         if (test_and_clear_bit(1, &cdev->private->registered))
 889                 device_unregister(&cdev->dev);
 890         put_device(&cdev->dev);
 891 }
 892
 893 static int
 894 io_subchannel_remove (struct subchannel *sch)
 895 {
 896         struct ccw_device *cdev;
 897         unsigned long flags;
 898
 899         if (!sch->dev.driver_data)
 900                 return 0;
 901         cdev = sch->dev.driver_data;
 902         /* Set ccw device to not operational and drop reference. */
 903         spin_lock_irqsave(cdev->ccwlock, flags);
 904         sch->dev.driver_data = NULL;
 905         cdev->private->state = DEV_STATE_NOT_OPER;
 906         spin_unlock_irqrestore(cdev->ccwlock, flags);
 907         /*
 908          * Put unregistration on workqueue to avoid livelocks on the css bus
 909          * semaphore.
 910          */
 911         if (get_device(&cdev->dev)) {
 912                 PREPARE_WORK(&cdev->private->kick_work,
 913                              ccw_device_unregister, cdev);
 914                 queue_work(ccw_device_work, &cdev->private->kick_work);
 915         }
 916         return 0;
 917 }
 918
 919 static int
 920 io_subchannel_notify(struct device *dev, int event)
 921 {
 922         struct ccw_device *cdev;
 923
 924         cdev = dev->driver_data;
 925         if (!cdev)
 926                 return 0;
 927         if (!cdev->drv)
 928                 return 0;
 929         if (!cdev->online)
 930                 return 0;
 931         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 932 }
 933
 934 static void
 935 io_subchannel_verify(struct device *dev)
 936 {
 937         struct ccw_device *cdev;
 938
 939         cdev = dev->driver_data;
 940         if (cdev)
 941                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 942 }
 943
 944 static void
 945 io_subchannel_ioterm(struct device *dev)
 946 {
 947         struct ccw_device *cdev;
 948
 949         cdev = dev->driver_data;
 950         if (!cdev)
 951                 return;
 952         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 953         if (cdev->handler)
 954                 cdev->handler(cdev, cdev->private->intparm,
 955                               ERR_PTR(-EIO));
 956 }
 957
 958 static void
 959 io_subchannel_shutdown(struct subchannel *sch)
 960 {
 961         struct ccw_device *cdev;
 962         int ret;
 963
 964         cdev = sch->dev.driver_data;
 965
 966         if (cio_is_console(sch->schid))
 967                 return;
 968         if (!sch->schib.pmcw.ena)
 969                 /* Nothing to do. */
 970                 return;
 971         ret = cio_disable_subchannel(sch);
 972         if (ret != -EBUSY)
 973                 /* Subchannel is disabled, we're done. */
 974                 return;
 975         cdev->private->state = DEV_STATE_QUIESCE;
 976         if (cdev->handler)
 977                 cdev->handler(cdev, cdev->private->intparm,
 978                               ERR_PTR(-EIO));
 979         ret = ccw_device_cancel_halt_clear(cdev);
 980         if (ret == -EBUSY) {
 981                 ccw_device_set_timeout(cdev, HZ/10);
 982                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 983         }
 984         cio_disable_subchannel(sch);
 985 }
 986
 987 #ifdef CONFIG_CCW_CONSOLE
 988 static struct ccw_device console_cdev;
 989 static struct ccw_device_private console_private;
 990 static int console_cdev_in_use;
 991
 992 static int
 993 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 994 {
 995         int rc;
 996
 997         /* Initialize the ccw_device structure. */
 998         cdev->dev.parent= &sch->dev;
 999         rc = io_subchannel_recog(cdev, sch);
1000         if (rc)
1001                 return rc;
1002
1003         /* Now wait for the async. recognition to come to an end. */
1004         spin_lock_irq(cdev->ccwlock);
1005         while (!dev_fsm_final_state(cdev))
1006                 wait_cons_dev();
1007         rc = -EIO;
1008         if (cdev->private->state != DEV_STATE_OFFLINE)
1009                 goto out_unlock;
1010         ccw_device_online(cdev);
1011         while (!dev_fsm_final_state(cdev))
1012                 wait_cons_dev();
1013         if (cdev->private->state != DEV_STATE_ONLINE)
1014                 goto out_unlock;
1015         rc = 0;
1016 out_unlock:
1017         spin_unlock_irq(cdev->ccwlock);
1018         return 0;
1019 }
1020
1021 struct ccw_device *
1022 ccw_device_probe_console(void)
1023 {
1024         struct subchannel *sch;
1025         int ret;
1026
1027         if (xchg(&console_cdev_in_use, 1) != 0)
1028                 return ERR_PTR(-EBUSY);
1029         sch = cio_probe_console();
1030         if (IS_ERR(sch)) {
1031                 console_cdev_in_use = 0;
1032                 return (void *) sch;
1033         }
1034         memset(&console_cdev, 0, sizeof(struct ccw_device));
1035         memset(&console_private, 0, sizeof(struct ccw_device_private));
1036         console_cdev.private = &console_private;
1037         ret = ccw_device_console_enable(&console_cdev, sch);
1038         if (ret) {
1039                 cio_release_console();
1040                 console_cdev_in_use = 0;
1041                 return ERR_PTR(ret);
1042         }
1043         console_cdev.online = 1;
1044         return &console_cdev;
1045 }
1046 #endif
1047
1048 /*
1049  * get ccw_device matching the busid, but only if owned by cdrv
1050  */
1051 static int
1052 __ccwdev_check_busid(struct device *dev, void *id)
1053 {
1054         char *bus_id;
1055
1056         bus_id = id;
1057
1058         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1059 }
1060
1061
1062 struct ccw_device *
1063 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1064 {
1065         struct device *dev;
1066         struct device_driver *drv;
1067
1068         drv = get_driver(&cdrv->driver);
1069         if (!drv)
1070                 return NULL;
1071
1072         dev = driver_find_device(drv, NULL, (void *)bus_id,
1073                                  __ccwdev_check_busid);
1074         put_driver(drv);
1075
1076         return dev ? to_ccwdev(dev) : NULL;
1077 }
1078
1079 /************************** device driver handling ************************/
1080
1081 /* This is the implementation of the ccw_driver class. The probe, remove
1082  * and release methods are initially very similar to the device_driver
1083  * implementations, with the difference that they have ccw_device
1084  * arguments.
1085  *
1086  * A ccw driver also contains the information that is needed for
1087  * device matching.
1088  */
1089 static int
1090 ccw_device_probe (struct device *dev)
1091 {
1092         struct ccw_device *cdev = to_ccwdev(dev);
1093         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1094         int ret;
1095
1096         cdev->drv = cdrv; /* to let the driver call _set_online */
1097
1098         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1099
1100         if (ret) {
1101                 cdev->drv = NULL;
1102                 return ret;
1103         }
1104
1105         return 0;
1106 }
1107
1108 static int
1109 ccw_device_remove (struct device *dev)
1110 {
1111         struct ccw_device *cdev = to_ccwdev(dev);
1112         struct ccw_driver *cdrv = cdev->drv;
1113         int ret;
1114
1115         pr_debug("removing device %s\n", cdev->dev.bus_id);
1116         if (cdrv->remove)
1117                 cdrv->remove(cdev);
1118         if (cdev->online) {
1119                 cdev->online = 0;
1120                 spin_lock_irq(cdev->ccwlock);
1121                 ret = ccw_device_offline(cdev);
1122                 spin_unlock_irq(cdev->ccwlock);
1123                 if (ret == 0)
1124                         wait_event(cdev->private->wait_q,
1125                                    dev_fsm_final_state(cdev));
1126                 else
1127                         //FIXME: we can't fail!
1128                         pr_debug("ccw_device_offline returned %d, device %s\n",
1129                                  ret, cdev->dev.bus_id);
1130         }
1131         ccw_device_set_timeout(cdev, 0);
1132         cdev->drv = NULL;
1133         return 0;
1134 }
1135
1136 struct bus_type ccw_bus_type = {
1137         .name   = "ccw",
1138         .match  = ccw_bus_match,
1139         .uevent = ccw_uevent,
1140         .probe  = ccw_device_probe,
1141         .remove = ccw_device_remove,
1142 };
1143
1144 int
1145 ccw_driver_register (struct ccw_driver *cdriver)
1146 {
1147         struct device_driver *drv = &cdriver->driver;
1148
1149         drv->bus = &ccw_bus_type;
1150         drv->name = cdriver->name;
1151
1152         return driver_register(drv);
1153 }
1154
1155 void
1156 ccw_driver_unregister (struct ccw_driver *cdriver)
1157 {
1158         driver_unregister(&cdriver->driver);
1159 }
1160
1161 /* Helper func for qdio. */
1162 struct subchannel_id
1163 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1164 {
1165         struct subchannel *sch;
1166
1167         sch = to_subchannel(cdev->dev.parent);
1168         return sch->schid;
1169 }
1170
1171 MODULE_LICENSE("GPL");
1172 EXPORT_SYMBOL(ccw_device_set_online);
1173 EXPORT_SYMBOL(ccw_device_set_offline);
1174 EXPORT_SYMBOL(ccw_driver_register);
1175 EXPORT_SYMBOL(ccw_driver_unregister);
1176 EXPORT_SYMBOL(get_ccwdev_by_busid);
1177 EXPORT_SYMBOL(ccw_bus_type);
1178 EXPORT_SYMBOL(ccw_device_work);
1179 EXPORT_SYMBOL(ccw_device_notify_work);
1180 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);