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   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.137 $
   5  *
   6  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   7  *                       IBM Corporation
   8  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   9  *               Cornelia Huck (cohuck@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         .name  = "ccw",
 112         .match = &ccw_bus_match,
 113         .uevent = &ccw_uevent,
 114 };
 115
 116 static int io_subchannel_probe (struct device *);
 117 static int io_subchannel_remove (struct device *);
 118 void io_subchannel_irq (struct device *);
 119 static int io_subchannel_notify(struct device *, int);
 120 static void io_subchannel_verify(struct device *);
 121 static void io_subchannel_ioterm(struct device *);
 122 static void io_subchannel_shutdown(struct device *);
 123
 124 struct css_driver io_subchannel_driver = {
 125         .subchannel_type = SUBCHANNEL_TYPE_IO,
 126         .drv = {
 127                 .name = "io_subchannel",
 128                 .bus  = &css_bus_type,
 129                 .probe = &io_subchannel_probe,
 130                 .remove = &io_subchannel_remove,
 131                 .shutdown = &io_subchannel_shutdown,
 132         },
 133         .irq = io_subchannel_irq,
 134         .notify = io_subchannel_notify,
 135         .verify = io_subchannel_verify,
 136         .termination = io_subchannel_ioterm,
 137 };
 138
 139 struct workqueue_struct *ccw_device_work;
 140 struct workqueue_struct *ccw_device_notify_work;
 141 static wait_queue_head_t ccw_device_init_wq;
 142 static atomic_t ccw_device_init_count;
 143
 144 static int __init
 145 init_ccw_bus_type (void)
 146 {
 147         int ret;
 148
 149         init_waitqueue_head(&ccw_device_init_wq);
 150         atomic_set(&ccw_device_init_count, 0);
 151
 152         ccw_device_work = create_singlethread_workqueue("cio");
 153         if (!ccw_device_work)
 154                 return -ENOMEM; /* FIXME: better errno ? */
 155         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 156         if (!ccw_device_notify_work) {
 157                 ret = -ENOMEM; /* FIXME: better errno ? */
 158                 goto out_err;
 159         }
 160         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 161         if (!slow_path_wq) {
 162                 ret = -ENOMEM; /* FIXME: better errno ? */
 163                 goto out_err;
 164         }
 165         if ((ret = bus_register (&ccw_bus_type)))
 166                 goto out_err;
 167
 168         if ((ret = driver_register(&io_subchannel_driver.drv)))
 169                 goto out_err;
 170
 171         wait_event(ccw_device_init_wq,
 172                    atomic_read(&ccw_device_init_count) == 0);
 173         flush_workqueue(ccw_device_work);
 174         return 0;
 175 out_err:
 176         if (ccw_device_work)
 177                 destroy_workqueue(ccw_device_work);
 178         if (ccw_device_notify_work)
 179                 destroy_workqueue(ccw_device_notify_work);
 180         if (slow_path_wq)
 181                 destroy_workqueue(slow_path_wq);
 182         return ret;
 183 }
 184
 185 static void __exit
 186 cleanup_ccw_bus_type (void)
 187 {
 188         driver_unregister(&io_subchannel_driver.drv);
 189         bus_unregister(&ccw_bus_type);
 190         destroy_workqueue(ccw_device_notify_work);
 191         destroy_workqueue(ccw_device_work);
 192 }
 193
 194 subsys_initcall(init_ccw_bus_type);
 195 module_exit(cleanup_ccw_bus_type);
 196
 197 /************************ device handling **************************/
 198
 199 /*
 200  * A ccw_device has some interfaces in sysfs in addition to the
 201  * standard ones.
 202  * The following entries are designed to export the information which
 203  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 204  * are obvious, so they don't have an entry :)
 205  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 206  */
 207 static ssize_t
 208 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 209 {
 210         struct subchannel *sch = to_subchannel(dev);
 211         struct ssd_info *ssd = &sch->ssd_info;
 212         ssize_t ret = 0;
 213         int chp;
 214
 215         for (chp = 0; chp < 8; chp++)
 216                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 217
 218         ret += sprintf (buf+ret, "\n");
 219         return min((ssize_t)PAGE_SIZE, ret);
 220 }
 221
 222 static ssize_t
 223 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 224 {
 225         struct subchannel *sch = to_subchannel(dev);
 226         struct pmcw *pmcw = &sch->schib.pmcw;
 227
 228         return sprintf (buf, "%02x %02x %02x\n",
 229                         pmcw->pim, pmcw->pam, pmcw->pom);
 230 }
 231
 232 static ssize_t
 233 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 234 {
 235         struct ccw_device *cdev = to_ccwdev(dev);
 236         struct ccw_device_id *id = &(cdev->id);
 237
 238         if (id->dev_type != 0)
 239                 return sprintf(buf, "%04x/%02x\n",
 240                                 id->dev_type, id->dev_model);
 241         else
 242                 return sprintf(buf, "n/a\n");
 243 }
 244
 245 static ssize_t
 246 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 247 {
 248         struct ccw_device *cdev = to_ccwdev(dev);
 249         struct ccw_device_id *id = &(cdev->id);
 250
 251         return sprintf(buf, "%04x/%02x\n",
 252                        id->cu_type, id->cu_model);
 253 }
 254
 255 static ssize_t
 256 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 257 {
 258         struct ccw_device *cdev = to_ccwdev(dev);
 259         struct ccw_device_id *id = &(cdev->id);
 260         int ret;
 261
 262         ret = sprintf(buf, "ccw:t%04Xm%02x",
 263                         id->cu_type, id->cu_model);
 264         if (id->dev_type != 0)
 265                 ret += sprintf(buf + ret, "dt%04Xdm%02X\n",
 266                                 id->dev_type, id->dev_model);
 267         else
 268                 ret += sprintf(buf + ret, "dtdm\n");
 269         return ret;
 270 }
 271
 272 static ssize_t
 273 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 274 {
 275         struct ccw_device *cdev = to_ccwdev(dev);
 276
 277         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 278 }
 279
 280 static void
 281 ccw_device_remove_disconnected(struct ccw_device *cdev)
 282 {
 283         struct subchannel *sch;
 284         /*
 285          * Forced offline in disconnected state means
 286          * 'throw away device'.
 287          */
 288         sch = to_subchannel(cdev->dev.parent);
 289         device_unregister(&sch->dev);
 290         /* Reset intparm to zeroes. */
 291         sch->schib.pmcw.intparm = 0;
 292         cio_modify(sch);
 293         put_device(&sch->dev);
 294 }
 295
 296 int
 297 ccw_device_set_offline(struct ccw_device *cdev)
 298 {
 299         int ret;
 300
 301         if (!cdev)
 302                 return -ENODEV;
 303         if (!cdev->online || !cdev->drv)
 304                 return -EINVAL;
 305
 306         if (cdev->drv->set_offline) {
 307                 ret = cdev->drv->set_offline(cdev);
 308                 if (ret != 0)
 309                         return ret;
 310         }
 311         cdev->online = 0;
 312         spin_lock_irq(cdev->ccwlock);
 313         ret = ccw_device_offline(cdev);
 314         if (ret == -ENODEV) {
 315                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 316                         cdev->private->state = DEV_STATE_OFFLINE;
 317                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 318                 }
 319                 spin_unlock_irq(cdev->ccwlock);
 320                 return ret;
 321         }
 322         spin_unlock_irq(cdev->ccwlock);
 323         if (ret == 0)
 324                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 325         else {
 326                 pr_debug("ccw_device_offline returned %d, device %s\n",
 327                          ret, cdev->dev.bus_id);
 328                 cdev->online = 1;
 329         }
 330         return ret;
 331 }
 332
 333 int
 334 ccw_device_set_online(struct ccw_device *cdev)
 335 {
 336         int ret;
 337
 338         if (!cdev)
 339                 return -ENODEV;
 340         if (cdev->online || !cdev->drv)
 341                 return -EINVAL;
 342
 343         spin_lock_irq(cdev->ccwlock);
 344         ret = ccw_device_online(cdev);
 345         spin_unlock_irq(cdev->ccwlock);
 346         if (ret == 0)
 347                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 348         else {
 349                 pr_debug("ccw_device_online returned %d, device %s\n",
 350                          ret, cdev->dev.bus_id);
 351                 return ret;
 352         }
 353         if (cdev->private->state != DEV_STATE_ONLINE)
 354                 return -ENODEV;
 355         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 356                 cdev->online = 1;
 357                 return 0;
 358         }
 359         spin_lock_irq(cdev->ccwlock);
 360         ret = ccw_device_offline(cdev);
 361         spin_unlock_irq(cdev->ccwlock);
 362         if (ret == 0)
 363                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 364         else
 365                 pr_debug("ccw_device_offline returned %d, device %s\n",
 366                          ret, cdev->dev.bus_id);
 367         return (ret = 0) ? -ENODEV : ret;
 368 }
 369
 370 static ssize_t
 371 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 372 {
 373         struct ccw_device *cdev = to_ccwdev(dev);
 374         int i, force, ret;
 375         char *tmp;
 376
 377         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 378                 return -EAGAIN;
 379
 380         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 381                 atomic_set(&cdev->private->onoff, 0);
 382                 return -EINVAL;
 383         }
 384         if (!strncmp(buf, "force\n", count)) {
 385                 force = 1;
 386                 i = 1;
 387         } else {
 388                 force = 0;
 389                 i = simple_strtoul(buf, &tmp, 16);
 390         }
 391         if (i == 1) {
 392                 /* Do device recognition, if needed. */
 393                 if (cdev->id.cu_type == 0) {
 394                         ret = ccw_device_recognition(cdev);
 395                         if (ret) {
 396                                 printk(KERN_WARNING"Couldn't start recognition "
 397                                        "for device %s (ret=%d)\n",
 398                                        cdev->dev.bus_id, ret);
 399                                 goto out;
 400                         }
 401                         wait_event(cdev->private->wait_q,
 402                                    cdev->private->flags.recog_done);
 403                 }
 404                 if (cdev->drv && cdev->drv->set_online)
 405                         ccw_device_set_online(cdev);
 406         } else if (i == 0) {
 407                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 408                         ccw_device_remove_disconnected(cdev);
 409                 else if (cdev->drv && cdev->drv->set_offline)
 410                         ccw_device_set_offline(cdev);
 411         }
 412         if (force && cdev->private->state == DEV_STATE_BOXED) {
 413                 ret = ccw_device_stlck(cdev);
 414                 if (ret) {
 415                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 416                                "returned %d!\n", cdev->dev.bus_id, ret);
 417                         goto out;
 418                 }
 419                 /* Do device recognition, if needed. */
 420                 if (cdev->id.cu_type == 0) {
 421                         cdev->private->state = DEV_STATE_NOT_OPER;
 422                         ret = ccw_device_recognition(cdev);
 423                         if (ret) {
 424                                 printk(KERN_WARNING"Couldn't start recognition "
 425                                        "for device %s (ret=%d)\n",
 426                                        cdev->dev.bus_id, ret);
 427                                 goto out;
 428                         }
 429                         wait_event(cdev->private->wait_q,
 430                                    cdev->private->flags.recog_done);
 431                 }
 432                 if (cdev->drv && cdev->drv->set_online)
 433                         ccw_device_set_online(cdev);
 434         }
 435         out:
 436         if (cdev->drv)
 437                 module_put(cdev->drv->owner);
 438         atomic_set(&cdev->private->onoff, 0);
 439         return count;
 440 }
 441
 442 static ssize_t
 443 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 444 {
 445         struct ccw_device *cdev = to_ccwdev(dev);
 446         struct subchannel *sch;
 447
 448         switch (cdev->private->state) {
 449         case DEV_STATE_BOXED:
 450                 return sprintf(buf, "boxed\n");
 451         case DEV_STATE_DISCONNECTED:
 452         case DEV_STATE_DISCONNECTED_SENSE_ID:
 453         case DEV_STATE_NOT_OPER:
 454                 sch = to_subchannel(dev->parent);
 455                 if (!sch->lpm)
 456                         return sprintf(buf, "no path\n");
 457                 else
 458                         return sprintf(buf, "no device\n");
 459         default:
 460                 /* All other states considered fine. */
 461                 return sprintf(buf, "good\n");
 462         }
 463 }
 464
 465 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 466 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 467 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 468 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 469 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 470 static DEVICE_ATTR(online, 0644, online_show, online_store);
 471 extern struct device_attribute dev_attr_cmb_enable;
 472 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 473
 474 static struct attribute * subch_attrs[] = {
 475         &dev_attr_chpids.attr,
 476         &dev_attr_pimpampom.attr,
 477         NULL,
 478 };
 479
 480 static struct attribute_group subch_attr_group = {
 481         .attrs = subch_attrs,
 482 };
 483
 484 static inline int
 485 subchannel_add_files (struct device *dev)
 486 {
 487         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 488 }
 489
 490 static struct attribute * ccwdev_attrs[] = {
 491         &dev_attr_devtype.attr,
 492         &dev_attr_cutype.attr,
 493         &dev_attr_modalias.attr,
 494         &dev_attr_online.attr,
 495         &dev_attr_cmb_enable.attr,
 496         &dev_attr_availability.attr,
 497         NULL,
 498 };
 499
 500 static struct attribute_group ccwdev_attr_group = {
 501         .attrs = ccwdev_attrs,
 502 };
 503
 504 static inline int
 505 device_add_files (struct device *dev)
 506 {
 507         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 508 }
 509
 510 static inline void
 511 device_remove_files(struct device *dev)
 512 {
 513         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 514 }
 515
 516 /* this is a simple abstraction for device_register that sets the
 517  * correct bus type and adds the bus specific files */
 518 int
 519 ccw_device_register(struct ccw_device *cdev)
 520 {
 521         struct device *dev = &cdev->dev;
 522         int ret;
 523
 524         dev->bus = &ccw_bus_type;
 525
 526         if ((ret = device_add(dev)))
 527                 return ret;
 528
 529         set_bit(1, &cdev->private->registered);
 530         if ((ret = device_add_files(dev))) {
 531                 if (test_and_clear_bit(1, &cdev->private->registered))
 532                         device_del(dev);
 533         }
 534         return ret;
 535 }
 536
 537 struct match_data {
 538         unsigned int devno;
 539         unsigned int ssid;
 540         struct ccw_device * sibling;
 541 };
 542
 543 static int
 544 match_devno(struct device * dev, void * data)
 545 {
 546         struct match_data * d = (struct match_data *)data;
 547         struct ccw_device * cdev;
 548
 549         cdev = to_ccwdev(dev);
 550         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 551             (cdev->private->devno == d->devno) &&
 552             (cdev->private->ssid == d->ssid) &&
 553             (cdev != d->sibling)) {
 554                 cdev->private->state = DEV_STATE_NOT_OPER;
 555                 return 1;
 556         }
 557         return 0;
 558 }
 559
 560 static struct ccw_device *
 561 get_disc_ccwdev_by_devno(unsigned int devno, unsigned int ssid,
 562                          struct ccw_device *sibling)
 563 {
 564         struct device *dev;
 565         struct match_data data = {
 566                 .devno   = devno,
 567                 .ssid    = ssid,
 568                 .sibling = sibling,
 569         };
 570
 571         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 572
 573         return dev ? to_ccwdev(dev) : NULL;
 574 }
 575
 576 static void
 577 ccw_device_add_changed(void *data)
 578 {
 579
 580         struct ccw_device *cdev;
 581
 582         cdev = (struct ccw_device *)data;
 583         if (device_add(&cdev->dev)) {
 584                 put_device(&cdev->dev);
 585                 return;
 586         }
 587         set_bit(1, &cdev->private->registered);
 588         if (device_add_files(&cdev->dev)) {
 589                 if (test_and_clear_bit(1, &cdev->private->registered))
 590                         device_unregister(&cdev->dev);
 591         }
 592 }
 593
 594 extern int css_get_ssd_info(struct subchannel *sch);
 595
 596 void
 597 ccw_device_do_unreg_rereg(void *data)
 598 {
 599         struct ccw_device *cdev;
 600         struct subchannel *sch;
 601         int need_rename;
 602
 603         cdev = (struct ccw_device *)data;
 604         sch = to_subchannel(cdev->dev.parent);
 605         if (cdev->private->devno != sch->schib.pmcw.dev) {
 606                 /*
 607                  * The device number has changed. This is usually only when
 608                  * a device has been detached under VM and then re-appeared
 609                  * on another subchannel because of a different attachment
 610                  * order than before. Ideally, we should should just switch
 611                  * subchannels, but unfortunately, this is not possible with
 612                  * the current implementation.
 613                  * Instead, we search for the old subchannel for this device
 614                  * number and deregister so there are no collisions with the
 615                  * newly registered ccw_device.
 616                  * FIXME: Find another solution so the block layer doesn't
 617                  *        get possibly sick...
 618                  */
 619                 struct ccw_device *other_cdev;
 620
 621                 need_rename = 1;
 622                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 623                                                       sch->schid.ssid, cdev);
 624                 if (other_cdev) {
 625                         struct subchannel *other_sch;
 626
 627                         other_sch = to_subchannel(other_cdev->dev.parent);
 628                         if (get_device(&other_sch->dev)) {
 629                                 stsch(other_sch->schid, &other_sch->schib);
 630                                 if (other_sch->schib.pmcw.dnv) {
 631                                         other_sch->schib.pmcw.intparm = 0;
 632                                         cio_modify(other_sch);
 633                                 }
 634                                 device_unregister(&other_sch->dev);
 635                         }
 636                 }
 637                 /* Update ssd info here. */
 638                 css_get_ssd_info(sch);
 639                 cdev->private->devno = sch->schib.pmcw.dev;
 640         } else
 641                 need_rename = 0;
 642         device_remove_files(&cdev->dev);
 643         if (test_and_clear_bit(1, &cdev->private->registered))
 644                 device_del(&cdev->dev);
 645         if (need_rename)
 646                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 647                           sch->schid.ssid, sch->schib.pmcw.dev);
 648         PREPARE_WORK(&cdev->private->kick_work,
 649                      ccw_device_add_changed, (void *)cdev);
 650         queue_work(ccw_device_work, &cdev->private->kick_work);
 651 }
 652
 653 static void
 654 ccw_device_release(struct device *dev)
 655 {
 656         struct ccw_device *cdev;
 657
 658         cdev = to_ccwdev(dev);
 659         kfree(cdev->private);
 660         kfree(cdev);
 661 }
 662
 663 /*
 664  * Register recognized device.
 665  */
 666 static void
 667 io_subchannel_register(void *data)
 668 {
 669         struct ccw_device *cdev;
 670         struct subchannel *sch;
 671         int ret;
 672         unsigned long flags;
 673
 674         cdev = (struct ccw_device *) data;
 675         sch = to_subchannel(cdev->dev.parent);
 676
 677         if (klist_node_attached(&cdev->dev.knode_parent)) {
 678                 bus_rescan_devices(&ccw_bus_type);
 679                 goto out;
 680         }
 681         /* make it known to the system */
 682         ret = ccw_device_register(cdev);
 683         if (ret) {
 684                 printk (KERN_WARNING "%s: could not register %s\n",
 685                         __func__, cdev->dev.bus_id);
 686                 put_device(&cdev->dev);
 687                 spin_lock_irqsave(&sch->lock, flags);
 688                 sch->dev.driver_data = NULL;
 689                 spin_unlock_irqrestore(&sch->lock, flags);
 690                 kfree (cdev->private);
 691                 kfree (cdev);
 692                 put_device(&sch->dev);
 693                 if (atomic_dec_and_test(&ccw_device_init_count))
 694                         wake_up(&ccw_device_init_wq);
 695                 return;
 696         }
 697
 698         ret = subchannel_add_files(cdev->dev.parent);
 699         if (ret)
 700                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 701                        __func__, sch->dev.bus_id);
 702         put_device(&cdev->dev);
 703 out:
 704         cdev->private->flags.recog_done = 1;
 705         put_device(&sch->dev);
 706         wake_up(&cdev->private->wait_q);
 707         if (atomic_dec_and_test(&ccw_device_init_count))
 708                 wake_up(&ccw_device_init_wq);
 709 }
 710
 711 void
 712 ccw_device_call_sch_unregister(void *data)
 713 {
 714         struct ccw_device *cdev = data;
 715         struct subchannel *sch;
 716
 717         sch = to_subchannel(cdev->dev.parent);
 718         device_unregister(&sch->dev);
 719         /* Reset intparm to zeroes. */
 720         sch->schib.pmcw.intparm = 0;
 721         cio_modify(sch);
 722         put_device(&cdev->dev);
 723         put_device(&sch->dev);
 724 }
 725
 726 /*
 727  * subchannel recognition done. Called from the state machine.
 728  */
 729 void
 730 io_subchannel_recog_done(struct ccw_device *cdev)
 731 {
 732         struct subchannel *sch;
 733
 734         if (css_init_done == 0) {
 735                 cdev->private->flags.recog_done = 1;
 736                 return;
 737         }
 738         switch (cdev->private->state) {
 739         case DEV_STATE_NOT_OPER:
 740                 cdev->private->flags.recog_done = 1;
 741                 /* Remove device found not operational. */
 742                 if (!get_device(&cdev->dev))
 743                         break;
 744                 sch = to_subchannel(cdev->dev.parent);
 745                 PREPARE_WORK(&cdev->private->kick_work,
 746                              ccw_device_call_sch_unregister, (void *) cdev);
 747                 queue_work(slow_path_wq, &cdev->private->kick_work);
 748                 if (atomic_dec_and_test(&ccw_device_init_count))
 749                         wake_up(&ccw_device_init_wq);
 750                 break;
 751         case DEV_STATE_BOXED:
 752                 /* Device did not respond in time. */
 753         case DEV_STATE_OFFLINE:
 754                 /*
 755                  * We can't register the device in interrupt context so
 756                  * we schedule a work item.
 757                  */
 758                 if (!get_device(&cdev->dev))
 759                         break;
 760                 PREPARE_WORK(&cdev->private->kick_work,
 761                              io_subchannel_register, (void *) cdev);
 762                 queue_work(slow_path_wq, &cdev->private->kick_work);
 763                 break;
 764         }
 765 }
 766
 767 static int
 768 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 769 {
 770         int rc;
 771         struct ccw_device_private *priv;
 772
 773         sch->dev.driver_data = cdev;
 774         sch->driver = &io_subchannel_driver;
 775         cdev->ccwlock = &sch->lock;
 776
 777         /* Init private data. */
 778         priv = cdev->private;
 779         priv->devno = sch->schib.pmcw.dev;
 780         priv->ssid = sch->schid.ssid;
 781         priv->sch_no = sch->schid.sch_no;
 782         priv->state = DEV_STATE_NOT_OPER;
 783         INIT_LIST_HEAD(&priv->cmb_list);
 784         init_waitqueue_head(&priv->wait_q);
 785         init_timer(&priv->timer);
 786
 787         /* Set an initial name for the device. */
 788         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 789                   sch->schid.ssid, sch->schib.pmcw.dev);
 790
 791         /* Increase counter of devices currently in recognition. */
 792         atomic_inc(&ccw_device_init_count);
 793
 794         /* Start async. device sensing. */
 795         spin_lock_irq(&sch->lock);
 796         rc = ccw_device_recognition(cdev);
 797         spin_unlock_irq(&sch->lock);
 798         if (rc) {
 799                 if (atomic_dec_and_test(&ccw_device_init_count))
 800                         wake_up(&ccw_device_init_wq);
 801         }
 802         return rc;
 803 }
 804
 805 static int
 806 io_subchannel_probe (struct device *pdev)
 807 {
 808         struct subchannel *sch;
 809         struct ccw_device *cdev;
 810         int rc;
 811         unsigned long flags;
 812
 813         sch = to_subchannel(pdev);
 814         if (sch->dev.driver_data) {
 815                 /*
 816                  * This subchannel already has an associated ccw_device.
 817                  * Register it and exit. This happens for all early
 818                  * device, e.g. the console.
 819                  */
 820                 cdev = sch->dev.driver_data;
 821                 device_initialize(&cdev->dev);
 822                 ccw_device_register(cdev);
 823                 subchannel_add_files(&sch->dev);
 824                 /*
 825                  * Check if the device is already online. If it is
 826                  * the reference count needs to be corrected
 827                  * (see ccw_device_online and css_init_done for the
 828                  * ugly details).
 829                  */
 830                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 831                     cdev->private->state != DEV_STATE_OFFLINE &&
 832                     cdev->private->state != DEV_STATE_BOXED)
 833                         get_device(&cdev->dev);
 834                 return 0;
 835         }
 836         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 837         if (!cdev)
 838                 return -ENOMEM;
 839         memset(cdev, 0, sizeof(struct ccw_device));
 840         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 841                                 GFP_KERNEL | GFP_DMA);
 842         if (!cdev->private) {
 843                 kfree(cdev);
 844                 return -ENOMEM;
 845         }
 846         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 847         atomic_set(&cdev->private->onoff, 0);
 848         cdev->dev = (struct device) {
 849                 .parent = pdev,
 850                 .release = ccw_device_release,
 851         };
 852         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 853         /* Do first half of device_register. */
 854         device_initialize(&cdev->dev);
 855
 856         if (!get_device(&sch->dev)) {
 857                 if (cdev->dev.release)
 858                         cdev->dev.release(&cdev->dev);
 859                 return -ENODEV;
 860         }
 861
 862         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 863         if (rc) {
 864                 spin_lock_irqsave(&sch->lock, flags);
 865                 sch->dev.driver_data = NULL;
 866                 spin_unlock_irqrestore(&sch->lock, flags);
 867                 if (cdev->dev.release)
 868                         cdev->dev.release(&cdev->dev);
 869         }
 870
 871         return rc;
 872 }
 873
 874 static void
 875 ccw_device_unregister(void *data)
 876 {
 877         struct ccw_device *cdev;
 878
 879         cdev = (struct ccw_device *)data;
 880         if (test_and_clear_bit(1, &cdev->private->registered))
 881                 device_unregister(&cdev->dev);
 882         put_device(&cdev->dev);
 883 }
 884
 885 static int
 886 io_subchannel_remove (struct device *dev)
 887 {
 888         struct ccw_device *cdev;
 889         unsigned long flags;
 890
 891         if (!dev->driver_data)
 892                 return 0;
 893         cdev = dev->driver_data;
 894         /* Set ccw device to not operational and drop reference. */
 895         spin_lock_irqsave(cdev->ccwlock, flags);
 896         dev->driver_data = NULL;
 897         cdev->private->state = DEV_STATE_NOT_OPER;
 898         spin_unlock_irqrestore(cdev->ccwlock, flags);
 899         /*
 900          * Put unregistration on workqueue to avoid livelocks on the css bus
 901          * semaphore.
 902          */
 903         if (get_device(&cdev->dev)) {
 904                 PREPARE_WORK(&cdev->private->kick_work,
 905                              ccw_device_unregister, (void *) cdev);
 906                 queue_work(ccw_device_work, &cdev->private->kick_work);
 907         }
 908         return 0;
 909 }
 910
 911 static int
 912 io_subchannel_notify(struct device *dev, int event)
 913 {
 914         struct ccw_device *cdev;
 915
 916         cdev = dev->driver_data;
 917         if (!cdev)
 918                 return 0;
 919         if (!cdev->drv)
 920                 return 0;
 921         if (!cdev->online)
 922                 return 0;
 923         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 924 }
 925
 926 static void
 927 io_subchannel_verify(struct device *dev)
 928 {
 929         struct ccw_device *cdev;
 930
 931         cdev = dev->driver_data;
 932         if (cdev)
 933                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 934 }
 935
 936 static void
 937 io_subchannel_ioterm(struct device *dev)
 938 {
 939         struct ccw_device *cdev;
 940
 941         cdev = dev->driver_data;
 942         if (!cdev)
 943                 return;
 944         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 945         if (cdev->handler)
 946                 cdev->handler(cdev, cdev->private->intparm,
 947                               ERR_PTR(-EIO));
 948 }
 949
 950 static void
 951 io_subchannel_shutdown(struct device *dev)
 952 {
 953         struct subchannel *sch;
 954         struct ccw_device *cdev;
 955         int ret;
 956
 957         sch = to_subchannel(dev);
 958         cdev = dev->driver_data;
 959
 960         if (cio_is_console(sch->schid))
 961                 return;
 962         if (!sch->schib.pmcw.ena)
 963                 /* Nothing to do. */
 964                 return;
 965         ret = cio_disable_subchannel(sch);
 966         if (ret != -EBUSY)
 967                 /* Subchannel is disabled, we're done. */
 968                 return;
 969         cdev->private->state = DEV_STATE_QUIESCE;
 970         if (cdev->handler)
 971                 cdev->handler(cdev, cdev->private->intparm,
 972                               ERR_PTR(-EIO));
 973         ret = ccw_device_cancel_halt_clear(cdev);
 974         if (ret == -EBUSY) {
 975                 ccw_device_set_timeout(cdev, HZ/10);
 976                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 977         }
 978         cio_disable_subchannel(sch);
 979 }
 980
 981 #ifdef CONFIG_CCW_CONSOLE
 982 static struct ccw_device console_cdev;
 983 static struct ccw_device_private console_private;
 984 static int console_cdev_in_use;
 985
 986 static int
 987 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 988 {
 989         int rc;
 990
 991         /* Initialize the ccw_device structure. */
 992         cdev->dev = (struct device) {
 993                 .parent = &sch->dev,
 994         };
 995         rc = io_subchannel_recog(cdev, sch);
 996         if (rc)
 997                 return rc;
 998
 999         /* Now wait for the async. recognition to come to an end. */
1000         spin_lock_irq(cdev->ccwlock);
1001         while (!dev_fsm_final_state(cdev))
1002                 wait_cons_dev();
1003         rc = -EIO;
1004         if (cdev->private->state != DEV_STATE_OFFLINE)
1005                 goto out_unlock;
1006         ccw_device_online(cdev);
1007         while (!dev_fsm_final_state(cdev))
1008                 wait_cons_dev();
1009         if (cdev->private->state != DEV_STATE_ONLINE)
1010                 goto out_unlock;
1011         rc = 0;
1012 out_unlock:
1013         spin_unlock_irq(cdev->ccwlock);
1014         return 0;
1015 }
1016
1017 struct ccw_device *
1018 ccw_device_probe_console(void)
1019 {
1020         struct subchannel *sch;
1021         int ret;
1022
1023         if (xchg(&console_cdev_in_use, 1) != 0)
1024                 return NULL;
1025         sch = cio_probe_console();
1026         if (IS_ERR(sch)) {
1027                 console_cdev_in_use = 0;
1028                 return (void *) sch;
1029         }
1030         memset(&console_cdev, 0, sizeof(struct ccw_device));
1031         memset(&console_private, 0, sizeof(struct ccw_device_private));
1032         console_cdev.private = &console_private;
1033         ret = ccw_device_console_enable(&console_cdev, sch);
1034         if (ret) {
1035                 cio_release_console();
1036                 console_cdev_in_use = 0;
1037                 return ERR_PTR(ret);
1038         }
1039         console_cdev.online = 1;
1040         return &console_cdev;
1041 }
1042 #endif
1043
1044 /*
1045  * get ccw_device matching the busid, but only if owned by cdrv
1046  */
1047 static int
1048 __ccwdev_check_busid(struct device *dev, void *id)
1049 {
1050         char *bus_id;
1051
1052         bus_id = (char *)id;
1053
1054         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1055 }
1056
1057
1058 struct ccw_device *
1059 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1060 {
1061         struct device *dev;
1062         struct device_driver *drv;
1063
1064         drv = get_driver(&cdrv->driver);
1065         if (!drv)
1066                 return NULL;
1067
1068         dev = driver_find_device(drv, NULL, (void *)bus_id,
1069                                  __ccwdev_check_busid);
1070         put_driver(drv);
1071
1072         return dev ? to_ccwdev(dev) : 0;
1073 }
1074
1075 /************************** device driver handling ************************/
1076
1077 /* This is the implementation of the ccw_driver class. The probe, remove
1078  * and release methods are initially very similar to the device_driver
1079  * implementations, with the difference that they have ccw_device
1080  * arguments.
1081  *
1082  * A ccw driver also contains the information that is needed for
1083  * device matching.
1084  */
1085 static int
1086 ccw_device_probe (struct device *dev)
1087 {
1088         struct ccw_device *cdev = to_ccwdev(dev);
1089         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1090         int ret;
1091
1092         cdev->drv = cdrv; /* to let the driver call _set_online */
1093
1094         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1095
1096         if (ret) {
1097                 cdev->drv = 0;
1098                 return ret;
1099         }
1100
1101         return 0;
1102 }
1103
1104 static int
1105 ccw_device_remove (struct device *dev)
1106 {
1107         struct ccw_device *cdev = to_ccwdev(dev);
1108         struct ccw_driver *cdrv = cdev->drv;
1109         int ret;
1110
1111         pr_debug("removing device %s\n", cdev->dev.bus_id);
1112         if (cdrv->remove)
1113                 cdrv->remove(cdev);
1114         if (cdev->online) {
1115                 cdev->online = 0;
1116                 spin_lock_irq(cdev->ccwlock);
1117                 ret = ccw_device_offline(cdev);
1118                 spin_unlock_irq(cdev->ccwlock);
1119                 if (ret == 0)
1120                         wait_event(cdev->private->wait_q,
1121                                    dev_fsm_final_state(cdev));
1122                 else
1123                         //FIXME: we can't fail!
1124                         pr_debug("ccw_device_offline returned %d, device %s\n",
1125                                  ret, cdev->dev.bus_id);
1126         }
1127         ccw_device_set_timeout(cdev, 0);
1128         cdev->drv = 0;
1129         return 0;
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         drv->probe = ccw_device_probe;
1140         drv->remove = ccw_device_remove;
1141
1142         return driver_register(drv);
1143 }
1144
1145 void
1146 ccw_driver_unregister (struct ccw_driver *cdriver)
1147 {
1148         driver_unregister(&cdriver->driver);
1149 }
1150
1151 /* Helper func for qdio. */
1152 struct subchannel_id
1153 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1154 {
1155         struct subchannel *sch;
1156
1157         sch = to_subchannel(cdev->dev.parent);
1158         return sch->schid;
1159 }
1160
1161 MODULE_LICENSE("GPL");
1162 EXPORT_SYMBOL(ccw_device_set_online);
1163 EXPORT_SYMBOL(ccw_device_set_offline);
1164 EXPORT_SYMBOL(ccw_driver_register);
1165 EXPORT_SYMBOL(ccw_driver_unregister);
1166 EXPORT_SYMBOL(get_ccwdev_by_busid);
1167 EXPORT_SYMBOL(ccw_bus_type);
1168 EXPORT_SYMBOL(ccw_device_work);
1169 EXPORT_SYMBOL(ccw_device_notify_work);
1170 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);