drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *   $Revision: 1.131 $
   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
  26 #include "cio.h"
  27 #include "css.h"
  28 #include "device.h"
  29 #include "ioasm.h"
  30
  31 /******************* bus type handling ***********************/
  32
  33 /* The Linux driver model distinguishes between a bus type and
  34  * the bus itself. Of course we only have one channel
  35  * subsystem driver and one channel system per machine, but
  36  * we still use the abstraction. T.R. says it's a good idea. */
  37 static int
  38 ccw_bus_match (struct device * dev, struct device_driver * drv)
  39 {
  40         struct ccw_device *cdev = to_ccwdev(dev);
  41         struct ccw_driver *cdrv = to_ccwdrv(drv);
  42         const struct ccw_device_id *ids = cdrv->ids, *found;
  43
  44         if (!ids)
  45                 return 0;
  46
  47         found = ccw_device_id_match(ids, &cdev->id);
  48         if (!found)
  49                 return 0;
  50
  51         cdev->id.driver_info = found->driver_info;
  52
  53         return 1;
  54 }
  55
  56 /*
  57  * Hotplugging interface for ccw devices.
  58  * Heavily modeled on pci and usb hotplug.
  59  */
  60 static int
  61 ccw_hotplug (struct device *dev, char **envp, int num_envp,
  62              char *buffer, int buffer_size)
  63 {
  64         struct ccw_device *cdev = to_ccwdev(dev);
  65         int i = 0;
  66         int length = 0;
  67
  68         if (!cdev)
  69                 return -ENODEV;
  70
  71         /* what we want to pass to /sbin/hotplug */
  72
  73         envp[i++] = buffer;
  74         length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
  75                            cdev->id.cu_type);
  76         if ((buffer_size - length <= 0) || (i >= num_envp))
  77                 return -ENOMEM;
  78         ++length;
  79         buffer += length;
  80
  81         envp[i++] = buffer;
  82         length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
  83                            cdev->id.cu_model);
  84         if ((buffer_size - length <= 0) || (i >= num_envp))
  85                 return -ENOMEM;
  86         ++length;
  87         buffer += length;
  88
  89         /* The next two can be zero, that's ok for us */
  90         envp[i++] = buffer;
  91         length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
  92                            cdev->id.dev_type);
  93         if ((buffer_size - length <= 0) || (i >= num_envp))
  94                 return -ENOMEM;
  95         ++length;
  96         buffer += length;
  97
  98         envp[i++] = buffer;
  99         length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
 100                            cdev->id.dev_model);
 101         if ((buffer_size - length <= 0) || (i >= num_envp))
 102                 return -ENOMEM;
 103
 104         envp[i] = 0;
 105
 106         return 0;
 107 }
 108
 109 struct bus_type ccw_bus_type = {
 110         .name  = "ccw",
 111         .match = &ccw_bus_match,
 112         .hotplug = &ccw_hotplug,
 113 };
 114
 115 static int io_subchannel_probe (struct device *);
 116 static int io_subchannel_remove (struct device *);
 117 void io_subchannel_irq (struct device *);
 118 static int io_subchannel_notify(struct device *, int);
 119 static void io_subchannel_verify(struct device *);
 120 static void io_subchannel_ioterm(struct device *);
 121 static void io_subchannel_shutdown(struct device *);
 122
 123 struct css_driver io_subchannel_driver = {
 124         .subchannel_type = SUBCHANNEL_TYPE_IO,
 125         .drv = {
 126                 .name = "io_subchannel",
 127                 .bus  = &css_bus_type,
 128                 .probe = &io_subchannel_probe,
 129                 .remove = &io_subchannel_remove,
 130                 .shutdown = &io_subchannel_shutdown,
 131         },
 132         .irq = io_subchannel_irq,
 133         .notify = io_subchannel_notify,
 134         .verify = io_subchannel_verify,
 135         .termination = io_subchannel_ioterm,
 136 };
 137
 138 struct workqueue_struct *ccw_device_work;
 139 struct workqueue_struct *ccw_device_notify_work;
 140 static wait_queue_head_t ccw_device_init_wq;
 141 static atomic_t ccw_device_init_count;
 142
 143 static int __init
 144 init_ccw_bus_type (void)
 145 {
 146         int ret;
 147
 148         init_waitqueue_head(&ccw_device_init_wq);
 149         atomic_set(&ccw_device_init_count, 0);
 150
 151         ccw_device_work = create_singlethread_workqueue("cio");
 152         if (!ccw_device_work)
 153                 return -ENOMEM; /* FIXME: better errno ? */
 154         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 155         if (!ccw_device_notify_work) {
 156                 ret = -ENOMEM; /* FIXME: better errno ? */
 157                 goto out_err;
 158         }
 159         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 160         if (!slow_path_wq) {
 161                 ret = -ENOMEM; /* FIXME: better errno ? */
 162                 goto out_err;
 163         }
 164         if ((ret = bus_register (&ccw_bus_type)))
 165                 goto out_err;
 166
 167         if ((ret = driver_register(&io_subchannel_driver.drv)))
 168                 goto out_err;
 169
 170         wait_event(ccw_device_init_wq,
 171                    atomic_read(&ccw_device_init_count) == 0);
 172         flush_workqueue(ccw_device_work);
 173         return 0;
 174 out_err:
 175         if (ccw_device_work)
 176                 destroy_workqueue(ccw_device_work);
 177         if (ccw_device_notify_work)
 178                 destroy_workqueue(ccw_device_notify_work);
 179         if (slow_path_wq)
 180                 destroy_workqueue(slow_path_wq);
 181         return ret;
 182 }
 183
 184 static void __exit
 185 cleanup_ccw_bus_type (void)
 186 {
 187         driver_unregister(&io_subchannel_driver.drv);
 188         bus_unregister(&ccw_bus_type);
 189         destroy_workqueue(ccw_device_notify_work);
 190         destroy_workqueue(ccw_device_work);
 191 }
 192
 193 subsys_initcall(init_ccw_bus_type);
 194 module_exit(cleanup_ccw_bus_type);
 195
 196 /************************ device handling **************************/
 197
 198 /*
 199  * A ccw_device has some interfaces in sysfs in addition to the
 200  * standard ones.
 201  * The following entries are designed to export the information which
 202  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 203  * are obvious, so they don't have an entry :)
 204  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 205  */
 206 static ssize_t
 207 chpids_show (struct device * dev, char * buf)
 208 {
 209         struct subchannel *sch = to_subchannel(dev);
 210         struct ssd_info *ssd = &sch->ssd_info;
 211         ssize_t ret = 0;
 212         int chp;
 213
 214         for (chp = 0; chp < 8; chp++)
 215                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 216
 217         ret += sprintf (buf+ret, "\n");
 218         return min((ssize_t)PAGE_SIZE, ret);
 219 }
 220
 221 static ssize_t
 222 pimpampom_show (struct device * dev, char * buf)
 223 {
 224         struct subchannel *sch = to_subchannel(dev);
 225         struct pmcw *pmcw = &sch->schib.pmcw;
 226
 227         return sprintf (buf, "%02x %02x %02x\n",
 228                         pmcw->pim, pmcw->pam, pmcw->pom);
 229 }
 230
 231 static ssize_t
 232 devtype_show (struct device *dev, char *buf)
 233 {
 234         struct ccw_device *cdev = to_ccwdev(dev);
 235         struct ccw_device_id *id = &(cdev->id);
 236
 237         if (id->dev_type != 0)
 238                 return sprintf(buf, "%04x/%02x\n",
 239                                 id->dev_type, id->dev_model);
 240         else
 241                 return sprintf(buf, "n/a\n");
 242 }
 243
 244 static ssize_t
 245 cutype_show (struct device *dev, char *buf)
 246 {
 247         struct ccw_device *cdev = to_ccwdev(dev);
 248         struct ccw_device_id *id = &(cdev->id);
 249
 250         return sprintf(buf, "%04x/%02x\n",
 251                        id->cu_type, id->cu_model);
 252 }
 253
 254 static ssize_t
 255 online_show (struct device *dev, char *buf)
 256 {
 257         struct ccw_device *cdev = to_ccwdev(dev);
 258
 259         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 260 }
 261
 262 static void
 263 ccw_device_remove_disconnected(struct ccw_device *cdev)
 264 {
 265         struct subchannel *sch;
 266         /*
 267          * Forced offline in disconnected state means
 268          * 'throw away device'.
 269          */
 270         sch = to_subchannel(cdev->dev.parent);
 271         device_unregister(&sch->dev);
 272         /* Reset intparm to zeroes. */
 273         sch->schib.pmcw.intparm = 0;
 274         cio_modify(sch);
 275         put_device(&sch->dev);
 276 }
 277
 278 int
 279 ccw_device_set_offline(struct ccw_device *cdev)
 280 {
 281         int ret;
 282
 283         if (!cdev)
 284                 return -ENODEV;
 285         if (!cdev->online || !cdev->drv)
 286                 return -EINVAL;
 287
 288         if (cdev->drv->set_offline) {
 289                 ret = cdev->drv->set_offline(cdev);
 290                 if (ret != 0)
 291                         return ret;
 292         }
 293         cdev->online = 0;
 294         spin_lock_irq(cdev->ccwlock);
 295         ret = ccw_device_offline(cdev);
 296         if (ret == -ENODEV) {
 297                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 298                         cdev->private->state = DEV_STATE_OFFLINE;
 299                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 300                 }
 301                 spin_unlock_irq(cdev->ccwlock);
 302                 return ret;
 303         }
 304         spin_unlock_irq(cdev->ccwlock);
 305         if (ret == 0)
 306                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 307         else {
 308                 pr_debug("ccw_device_offline returned %d, device %s\n",
 309                          ret, cdev->dev.bus_id);
 310                 cdev->online = 1;
 311         }
 312         return ret;
 313 }
 314
 315 int
 316 ccw_device_set_online(struct ccw_device *cdev)
 317 {
 318         int ret;
 319
 320         if (!cdev)
 321                 return -ENODEV;
 322         if (cdev->online || !cdev->drv)
 323                 return -EINVAL;
 324
 325         spin_lock_irq(cdev->ccwlock);
 326         ret = ccw_device_online(cdev);
 327         spin_unlock_irq(cdev->ccwlock);
 328         if (ret == 0)
 329                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 330         else {
 331                 pr_debug("ccw_device_online returned %d, device %s\n",
 332                          ret, cdev->dev.bus_id);
 333                 return ret;
 334         }
 335         if (cdev->private->state != DEV_STATE_ONLINE)
 336                 return -ENODEV;
 337         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 338                 cdev->online = 1;
 339                 return 0;
 340         }
 341         spin_lock_irq(cdev->ccwlock);
 342         ret = ccw_device_offline(cdev);
 343         spin_unlock_irq(cdev->ccwlock);
 344         if (ret == 0)
 345                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 346         else
 347                 pr_debug("ccw_device_offline returned %d, device %s\n",
 348                          ret, cdev->dev.bus_id);
 349         return (ret = 0) ? -ENODEV : ret;
 350 }
 351
 352 static ssize_t
 353 online_store (struct device *dev, const char *buf, size_t count)
 354 {
 355         struct ccw_device *cdev = to_ccwdev(dev);
 356         int i, force, ret;
 357         char *tmp;
 358
 359         if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
 360                 return -EAGAIN;
 361
 362         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 363                 atomic_set(&cdev->private->onoff, 0);
 364                 return -EINVAL;
 365         }
 366         if (!strncmp(buf, "force\n", count)) {
 367                 force = 1;
 368                 i = 1;
 369         } else {
 370                 force = 0;
 371                 i = simple_strtoul(buf, &tmp, 16);
 372         }
 373         if (i == 1) {
 374                 /* Do device recognition, if needed. */
 375                 if (cdev->id.cu_type == 0) {
 376                         ret = ccw_device_recognition(cdev);
 377                         if (ret) {
 378                                 printk(KERN_WARNING"Couldn't start recognition "
 379                                        "for device %s (ret=%d)\n",
 380                                        cdev->dev.bus_id, ret);
 381                                 goto out;
 382                         }
 383                         wait_event(cdev->private->wait_q,
 384                                    cdev->private->flags.recog_done);
 385                 }
 386                 if (cdev->drv && cdev->drv->set_online)
 387                         ccw_device_set_online(cdev);
 388         } else if (i == 0) {
 389                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 390                         ccw_device_remove_disconnected(cdev);
 391                 else if (cdev->drv && cdev->drv->set_offline)
 392                         ccw_device_set_offline(cdev);
 393         }
 394         if (force && cdev->private->state == DEV_STATE_BOXED) {
 395                 ret = ccw_device_stlck(cdev);
 396                 if (ret) {
 397                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 398                                "returned %d!\n", cdev->dev.bus_id, ret);
 399                         goto out;
 400                 }
 401                 /* Do device recognition, if needed. */
 402                 if (cdev->id.cu_type == 0) {
 403                         cdev->private->state = DEV_STATE_NOT_OPER;
 404                         ret = ccw_device_recognition(cdev);
 405                         if (ret) {
 406                                 printk(KERN_WARNING"Couldn't start recognition "
 407                                        "for device %s (ret=%d)\n",
 408                                        cdev->dev.bus_id, ret);
 409                                 goto out;
 410                         }
 411                         wait_event(cdev->private->wait_q,
 412                                    cdev->private->flags.recog_done);
 413                 }
 414                 if (cdev->drv && cdev->drv->set_online)
 415                         ccw_device_set_online(cdev);
 416         }
 417         out:
 418         if (cdev->drv)
 419                 module_put(cdev->drv->owner);
 420         atomic_set(&cdev->private->onoff, 0);
 421         return count;
 422 }
 423
 424 static ssize_t
 425 available_show (struct device *dev, char *buf)
 426 {
 427         struct ccw_device *cdev = to_ccwdev(dev);
 428         struct subchannel *sch;
 429
 430         switch (cdev->private->state) {
 431         case DEV_STATE_BOXED:
 432                 return sprintf(buf, "boxed\n");
 433         case DEV_STATE_DISCONNECTED:
 434         case DEV_STATE_DISCONNECTED_SENSE_ID:
 435         case DEV_STATE_NOT_OPER:
 436                 sch = to_subchannel(dev->parent);
 437                 if (!sch->lpm)
 438                         return sprintf(buf, "no path\n");
 439                 else
 440                         return sprintf(buf, "no device\n");
 441         default:
 442                 /* All other states considered fine. */
 443                 return sprintf(buf, "good\n");
 444         }
 445 }
 446
 447 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 448 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 449 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 450 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 451 static DEVICE_ATTR(online, 0644, online_show, online_store);
 452 extern struct device_attribute dev_attr_cmb_enable;
 453 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 454
 455 static struct attribute * subch_attrs[] = {
 456         &dev_attr_chpids.attr,
 457         &dev_attr_pimpampom.attr,
 458         NULL,
 459 };
 460
 461 static struct attribute_group subch_attr_group = {
 462         .attrs = subch_attrs,
 463 };
 464
 465 static inline int
 466 subchannel_add_files (struct device *dev)
 467 {
 468         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 469 }
 470
 471 static struct attribute * ccwdev_attrs[] = {
 472         &dev_attr_devtype.attr,
 473         &dev_attr_cutype.attr,
 474         &dev_attr_online.attr,
 475         &dev_attr_cmb_enable.attr,
 476         &dev_attr_availability.attr,
 477         NULL,
 478 };
 479
 480 static struct attribute_group ccwdev_attr_group = {
 481         .attrs = ccwdev_attrs,
 482 };
 483
 484 static inline int
 485 device_add_files (struct device *dev)
 486 {
 487         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 488 }
 489
 490 static inline void
 491 device_remove_files(struct device *dev)
 492 {
 493         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 494 }
 495
 496 /* this is a simple abstraction for device_register that sets the
 497  * correct bus type and adds the bus specific files */
 498 int
 499 ccw_device_register(struct ccw_device *cdev)
 500 {
 501         struct device *dev = &cdev->dev;
 502         int ret;
 503
 504         dev->bus = &ccw_bus_type;
 505
 506         if ((ret = device_add(dev)))
 507                 return ret;
 508
 509         set_bit(1, &cdev->private->registered);
 510         if ((ret = device_add_files(dev))) {
 511                 if (test_and_clear_bit(1, &cdev->private->registered))
 512                         device_del(dev);
 513         }
 514         return ret;
 515 }
 516
 517 static struct ccw_device *
 518 get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
 519 {
 520         struct ccw_device *cdev;
 521         struct list_head *entry;
 522         struct device *dev;
 523
 524         if (!get_bus(&ccw_bus_type))
 525                 return NULL;
 526         down_read(&ccw_bus_type.subsys.rwsem);
 527         cdev = NULL;
 528         list_for_each(entry, &ccw_bus_type.devices.list) {
 529                 dev = get_device(container_of(entry,
 530                                               struct device, bus_list));
 531                 if (!dev)
 532                         continue;
 533                 cdev = to_ccwdev(dev);
 534                 if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 535                     (cdev->private->devno == devno) &&
 536                     (cdev != sibling)) {
 537                         cdev->private->state = DEV_STATE_NOT_OPER;
 538                         break;
 539                 }
 540                 put_device(dev);
 541                 cdev = NULL;
 542         }
 543         up_read(&ccw_bus_type.subsys.rwsem);
 544         put_bus(&ccw_bus_type);
 545
 546         return cdev;
 547 }
 548
 549 static void
 550 ccw_device_add_changed(void *data)
 551 {
 552
 553         struct ccw_device *cdev;
 554
 555         cdev = (struct ccw_device *)data;
 556         if (device_add(&cdev->dev)) {
 557                 put_device(&cdev->dev);
 558                 return;
 559         }
 560         set_bit(1, &cdev->private->registered);
 561         if (device_add_files(&cdev->dev)) {
 562                 if (test_and_clear_bit(1, &cdev->private->registered))
 563                         device_unregister(&cdev->dev);
 564         }
 565 }
 566
 567 extern int css_get_ssd_info(struct subchannel *sch);
 568
 569 void
 570 ccw_device_do_unreg_rereg(void *data)
 571 {
 572         struct ccw_device *cdev;
 573         struct subchannel *sch;
 574         int need_rename;
 575
 576         cdev = (struct ccw_device *)data;
 577         sch = to_subchannel(cdev->dev.parent);
 578         if (cdev->private->devno != sch->schib.pmcw.dev) {
 579                 /*
 580                  * The device number has changed. This is usually only when
 581                  * a device has been detached under VM and then re-appeared
 582                  * on another subchannel because of a different attachment
 583                  * order than before. Ideally, we should should just switch
 584                  * subchannels, but unfortunately, this is not possible with
 585                  * the current implementation.
 586                  * Instead, we search for the old subchannel for this device
 587                  * number and deregister so there are no collisions with the
 588                  * newly registered ccw_device.
 589                  * FIXME: Find another solution so the block layer doesn't
 590                  *        get possibly sick...
 591                  */
 592                 struct ccw_device *other_cdev;
 593
 594                 need_rename = 1;
 595                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 596                                                       cdev);
 597                 if (other_cdev) {
 598                         struct subchannel *other_sch;
 599
 600                         other_sch = to_subchannel(other_cdev->dev.parent);
 601                         if (get_device(&other_sch->dev)) {
 602                                 stsch(other_sch->irq, &other_sch->schib);
 603                                 if (other_sch->schib.pmcw.dnv) {
 604                                         other_sch->schib.pmcw.intparm = 0;
 605                                         cio_modify(other_sch);
 606                                 }
 607                                 device_unregister(&other_sch->dev);
 608                         }
 609                 }
 610                 /* Update ssd info here. */
 611                 css_get_ssd_info(sch);
 612                 cdev->private->devno = sch->schib.pmcw.dev;
 613         } else
 614                 need_rename = 0;
 615         device_remove_files(&cdev->dev);
 616         if (test_and_clear_bit(1, &cdev->private->registered))
 617                 device_del(&cdev->dev);
 618         if (need_rename)
 619                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 620                           sch->schib.pmcw.dev);
 621         PREPARE_WORK(&cdev->private->kick_work,
 622                      ccw_device_add_changed, (void *)cdev);
 623         queue_work(ccw_device_work, &cdev->private->kick_work);
 624 }
 625
 626 static void
 627 ccw_device_release(struct device *dev)
 628 {
 629         struct ccw_device *cdev;
 630
 631         cdev = to_ccwdev(dev);
 632         kfree(cdev->private);
 633         kfree(cdev);
 634 }
 635
 636 /*
 637  * Register recognized device.
 638  */
 639 static void
 640 io_subchannel_register(void *data)
 641 {
 642         struct ccw_device *cdev;
 643         struct subchannel *sch;
 644         int ret;
 645         unsigned long flags;
 646
 647         cdev = (struct ccw_device *) data;
 648         sch = to_subchannel(cdev->dev.parent);
 649
 650         if (!list_empty(&sch->dev.children)) {
 651                 bus_rescan_devices(&ccw_bus_type);
 652                 goto out;
 653         }
 654         /* make it known to the system */
 655         ret = ccw_device_register(cdev);
 656         if (ret) {
 657                 printk (KERN_WARNING "%s: could not register %s\n",
 658                         __func__, cdev->dev.bus_id);
 659                 put_device(&cdev->dev);
 660                 spin_lock_irqsave(&sch->lock, flags);
 661                 sch->dev.driver_data = NULL;
 662                 spin_unlock_irqrestore(&sch->lock, flags);
 663                 kfree (cdev->private);
 664                 kfree (cdev);
 665                 put_device(&sch->dev);
 666                 if (atomic_dec_and_test(&ccw_device_init_count))
 667                         wake_up(&ccw_device_init_wq);
 668                 return;
 669         }
 670
 671         ret = subchannel_add_files(cdev->dev.parent);
 672         if (ret)
 673                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 674                        __func__, sch->dev.bus_id);
 675         put_device(&cdev->dev);
 676 out:
 677         cdev->private->flags.recog_done = 1;
 678         put_device(&sch->dev);
 679         wake_up(&cdev->private->wait_q);
 680         if (atomic_dec_and_test(&ccw_device_init_count))
 681                 wake_up(&ccw_device_init_wq);
 682 }
 683
 684 void
 685 ccw_device_call_sch_unregister(void *data)
 686 {
 687         struct ccw_device *cdev = data;
 688         struct subchannel *sch;
 689
 690         sch = to_subchannel(cdev->dev.parent);
 691         device_unregister(&sch->dev);
 692         /* Reset intparm to zeroes. */
 693         sch->schib.pmcw.intparm = 0;
 694         cio_modify(sch);
 695         put_device(&cdev->dev);
 696         put_device(&sch->dev);
 697 }
 698
 699 /*
 700  * subchannel recognition done. Called from the state machine.
 701  */
 702 void
 703 io_subchannel_recog_done(struct ccw_device *cdev)
 704 {
 705         struct subchannel *sch;
 706
 707         if (css_init_done == 0) {
 708                 cdev->private->flags.recog_done = 1;
 709                 return;
 710         }
 711         switch (cdev->private->state) {
 712         case DEV_STATE_NOT_OPER:
 713                 cdev->private->flags.recog_done = 1;
 714                 /* Remove device found not operational. */
 715                 if (!get_device(&cdev->dev))
 716                         break;
 717                 sch = to_subchannel(cdev->dev.parent);
 718                 PREPARE_WORK(&cdev->private->kick_work,
 719                              ccw_device_call_sch_unregister, (void *) cdev);
 720                 queue_work(slow_path_wq, &cdev->private->kick_work);
 721                 if (atomic_dec_and_test(&ccw_device_init_count))
 722                         wake_up(&ccw_device_init_wq);
 723                 break;
 724         case DEV_STATE_BOXED:
 725                 /* Device did not respond in time. */
 726         case DEV_STATE_OFFLINE:
 727                 /*
 728                  * We can't register the device in interrupt context so
 729                  * we schedule a work item.
 730                  */
 731                 if (!get_device(&cdev->dev))
 732                         break;
 733                 PREPARE_WORK(&cdev->private->kick_work,
 734                              io_subchannel_register, (void *) cdev);
 735                 queue_work(slow_path_wq, &cdev->private->kick_work);
 736                 break;
 737         }
 738 }
 739
 740 static int
 741 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 742 {
 743         int rc;
 744         struct ccw_device_private *priv;
 745
 746         sch->dev.driver_data = cdev;
 747         sch->driver = &io_subchannel_driver;
 748         cdev->ccwlock = &sch->lock;
 749         /* Init private data. */
 750         priv = cdev->private;
 751         priv->devno = sch->schib.pmcw.dev;
 752         priv->irq = sch->irq;
 753         priv->state = DEV_STATE_NOT_OPER;
 754         INIT_LIST_HEAD(&priv->cmb_list);
 755         init_waitqueue_head(&priv->wait_q);
 756         init_timer(&priv->timer);
 757
 758         /* Set an initial name for the device. */
 759         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 760                   sch->schib.pmcw.dev);
 761
 762         /* Increase counter of devices currently in recognition. */
 763         atomic_inc(&ccw_device_init_count);
 764
 765         /* Start async. device sensing. */
 766         spin_lock_irq(&sch->lock);
 767         rc = ccw_device_recognition(cdev);
 768         spin_unlock_irq(&sch->lock);
 769         if (rc) {
 770                 if (atomic_dec_and_test(&ccw_device_init_count))
 771                         wake_up(&ccw_device_init_wq);
 772         }
 773         return rc;
 774 }
 775
 776 static int
 777 io_subchannel_probe (struct device *pdev)
 778 {
 779         struct subchannel *sch;
 780         struct ccw_device *cdev;
 781         int rc;
 782         unsigned long flags;
 783
 784         sch = to_subchannel(pdev);
 785         if (sch->dev.driver_data) {
 786                 /*
 787                  * This subchannel already has an associated ccw_device.
 788                  * Register it and exit. This happens for all early
 789                  * device, e.g. the console.
 790                  */
 791                 cdev = sch->dev.driver_data;
 792                 device_initialize(&cdev->dev);
 793                 ccw_device_register(cdev);
 794                 subchannel_add_files(&sch->dev);
 795                 /*
 796                  * Check if the device is already online. If it is
 797                  * the reference count needs to be corrected
 798                  * (see ccw_device_online and css_init_done for the
 799                  * ugly details).
 800                  */
 801                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 802                     cdev->private->state != DEV_STATE_OFFLINE &&
 803                     cdev->private->state != DEV_STATE_BOXED)
 804                         get_device(&cdev->dev);
 805                 return 0;
 806         }
 807         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 808         if (!cdev)
 809                 return -ENOMEM;
 810         memset(cdev, 0, sizeof(struct ccw_device));
 811         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 812                                 GFP_KERNEL | GFP_DMA);
 813         if (!cdev->private) {
 814                 kfree(cdev);
 815                 return -ENOMEM;
 816         }
 817         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 818         atomic_set(&cdev->private->onoff, 0);
 819         cdev->dev = (struct device) {
 820                 .parent = pdev,
 821                 .release = ccw_device_release,
 822         };
 823         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 824         /* Do first half of device_register. */
 825         device_initialize(&cdev->dev);
 826
 827         if (!get_device(&sch->dev)) {
 828                 if (cdev->dev.release)
 829                         cdev->dev.release(&cdev->dev);
 830                 return -ENODEV;
 831         }
 832
 833         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 834         if (rc) {
 835                 spin_lock_irqsave(&sch->lock, flags);
 836                 sch->dev.driver_data = NULL;
 837                 spin_unlock_irqrestore(&sch->lock, flags);
 838                 if (cdev->dev.release)
 839                         cdev->dev.release(&cdev->dev);
 840         }
 841
 842         return rc;
 843 }
 844
 845 static void
 846 ccw_device_unregister(void *data)
 847 {
 848         struct ccw_device *cdev;
 849
 850         cdev = (struct ccw_device *)data;
 851         if (test_and_clear_bit(1, &cdev->private->registered))
 852                 device_unregister(&cdev->dev);
 853         put_device(&cdev->dev);
 854 }
 855
 856 static int
 857 io_subchannel_remove (struct device *dev)
 858 {
 859         struct ccw_device *cdev;
 860         unsigned long flags;
 861
 862         if (!dev->driver_data)
 863                 return 0;
 864         cdev = dev->driver_data;
 865         /* Set ccw device to not operational and drop reference. */
 866         spin_lock_irqsave(cdev->ccwlock, flags);
 867         dev->driver_data = NULL;
 868         cdev->private->state = DEV_STATE_NOT_OPER;
 869         spin_unlock_irqrestore(cdev->ccwlock, flags);
 870         /*
 871          * Put unregistration on workqueue to avoid livelocks on the css bus
 872          * semaphore.
 873          */
 874         if (get_device(&cdev->dev)) {
 875                 PREPARE_WORK(&cdev->private->kick_work,
 876                              ccw_device_unregister, (void *) cdev);
 877                 queue_work(ccw_device_work, &cdev->private->kick_work);
 878         }
 879         return 0;
 880 }
 881
 882 static int
 883 io_subchannel_notify(struct device *dev, int event)
 884 {
 885         struct ccw_device *cdev;
 886
 887         cdev = dev->driver_data;
 888         if (!cdev)
 889                 return 0;
 890         if (!cdev->drv)
 891                 return 0;
 892         if (!cdev->online)
 893                 return 0;
 894         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 895 }
 896
 897 static void
 898 io_subchannel_verify(struct device *dev)
 899 {
 900         struct ccw_device *cdev;
 901
 902         cdev = dev->driver_data;
 903         if (cdev)
 904                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 905 }
 906
 907 static void
 908 io_subchannel_ioterm(struct device *dev)
 909 {
 910         struct ccw_device *cdev;
 911
 912         cdev = dev->driver_data;
 913         if (!cdev)
 914                 return;
 915         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 916         if (cdev->handler)
 917                 cdev->handler(cdev, cdev->private->intparm,
 918                               ERR_PTR(-EIO));
 919 }
 920
 921 static void
 922 io_subchannel_shutdown(struct device *dev)
 923 {
 924         struct subchannel *sch;
 925         struct ccw_device *cdev;
 926         int ret;
 927
 928         sch = to_subchannel(dev);
 929         cdev = dev->driver_data;
 930
 931         if (cio_is_console(sch->irq))
 932                 return;
 933         if (!sch->schib.pmcw.ena)
 934                 /* Nothing to do. */
 935                 return;
 936         ret = cio_disable_subchannel(sch);
 937         if (ret != -EBUSY)
 938                 /* Subchannel is disabled, we're done. */
 939                 return;
 940         cdev->private->state = DEV_STATE_QUIESCE;
 941         if (cdev->handler)
 942                 cdev->handler(cdev, cdev->private->intparm,
 943                               ERR_PTR(-EIO));
 944         ret = ccw_device_cancel_halt_clear(cdev);
 945         if (ret == -EBUSY) {
 946                 ccw_device_set_timeout(cdev, HZ/10);
 947                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 948         }
 949         cio_disable_subchannel(sch);
 950 }
 951
 952 #ifdef CONFIG_CCW_CONSOLE
 953 static struct ccw_device console_cdev;
 954 static struct ccw_device_private console_private;
 955 static int console_cdev_in_use;
 956
 957 static int
 958 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 959 {
 960         int rc;
 961
 962         /* Initialize the ccw_device structure. */
 963         cdev->dev = (struct device) {
 964                 .parent = &sch->dev,
 965         };
 966         /* Initialize the subchannel structure */
 967         sch->dev.parent = &css_bus_device;
 968         sch->dev.bus = &css_bus_type;
 969
 970         rc = io_subchannel_recog(cdev, sch);
 971         if (rc)
 972                 return rc;
 973
 974         /* Now wait for the async. recognition to come to an end. */
 975         spin_lock_irq(cdev->ccwlock);
 976         while (!dev_fsm_final_state(cdev))
 977                 wait_cons_dev();
 978         rc = -EIO;
 979         if (cdev->private->state != DEV_STATE_OFFLINE)
 980                 goto out_unlock;
 981         ccw_device_online(cdev);
 982         while (!dev_fsm_final_state(cdev))
 983                 wait_cons_dev();
 984         if (cdev->private->state != DEV_STATE_ONLINE)
 985                 goto out_unlock;
 986         rc = 0;
 987 out_unlock:
 988         spin_unlock_irq(cdev->ccwlock);
 989         return 0;
 990 }
 991
 992 struct ccw_device *
 993 ccw_device_probe_console(void)
 994 {
 995         struct subchannel *sch;
 996         int ret;
 997
 998         if (xchg(&console_cdev_in_use, 1) != 0)
 999                 return NULL;
1000         sch = cio_probe_console();
1001         if (IS_ERR(sch)) {
1002                 console_cdev_in_use = 0;
1003                 return (void *) sch;
1004         }
1005         memset(&console_cdev, 0, sizeof(struct ccw_device));
1006         memset(&console_private, 0, sizeof(struct ccw_device_private));
1007         console_cdev.private = &console_private;
1008         ret = ccw_device_console_enable(&console_cdev, sch);
1009         if (ret) {
1010                 cio_release_console();
1011                 console_cdev_in_use = 0;
1012                 return ERR_PTR(ret);
1013         }
1014         console_cdev.online = 1;
1015         return &console_cdev;
1016 }
1017 #endif
1018
1019 /*
1020  * get ccw_device matching the busid, but only if owned by cdrv
1021  */
1022 struct ccw_device *
1023 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1024 {
1025         struct device *d, *dev;
1026         struct device_driver *drv;
1027
1028         drv = get_driver(&cdrv->driver);
1029         if (!drv)
1030                 return 0;
1031
1032         down_read(&drv->bus->subsys.rwsem);
1033
1034         dev = NULL;
1035         list_for_each_entry(d, &drv->devices, driver_list) {
1036                 dev = get_device(d);
1037
1038                 if (dev && !strncmp(bus_id, dev->bus_id, BUS_ID_SIZE))
1039                         break;
1040                 else if (dev) {
1041                         put_device(dev);
1042                         dev = NULL;
1043                 }
1044         }
1045         up_read(&drv->bus->subsys.rwsem);
1046         put_driver(drv);
1047
1048         return dev ? to_ccwdev(dev) : 0;
1049 }
1050
1051 /************************** device driver handling ************************/
1052
1053 /* This is the implementation of the ccw_driver class. The probe, remove
1054  * and release methods are initially very similar to the device_driver
1055  * implementations, with the difference that they have ccw_device
1056  * arguments.
1057  *
1058  * A ccw driver also contains the information that is needed for
1059  * device matching.
1060  */
1061 static int
1062 ccw_device_probe (struct device *dev)
1063 {
1064         struct ccw_device *cdev = to_ccwdev(dev);
1065         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1066         int ret;
1067
1068         cdev->drv = cdrv; /* to let the driver call _set_online */
1069
1070         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1071
1072         if (ret) {
1073                 cdev->drv = 0;
1074                 return ret;
1075         }
1076
1077         return 0;
1078 }
1079
1080 static int
1081 ccw_device_remove (struct device *dev)
1082 {
1083         struct ccw_device *cdev = to_ccwdev(dev);
1084         struct ccw_driver *cdrv = cdev->drv;
1085         int ret;
1086
1087         pr_debug("removing device %s\n", cdev->dev.bus_id);
1088         if (cdrv->remove)
1089                 cdrv->remove(cdev);
1090         if (cdev->online) {
1091                 cdev->online = 0;
1092                 spin_lock_irq(cdev->ccwlock);
1093                 ret = ccw_device_offline(cdev);
1094                 spin_unlock_irq(cdev->ccwlock);
1095                 if (ret == 0)
1096                         wait_event(cdev->private->wait_q,
1097                                    dev_fsm_final_state(cdev));
1098                 else
1099                         //FIXME: we can't fail!
1100                         pr_debug("ccw_device_offline returned %d, device %s\n",
1101                                  ret, cdev->dev.bus_id);
1102         }
1103         ccw_device_set_timeout(cdev, 0);
1104         cdev->drv = 0;
1105         return 0;
1106 }
1107
1108 int
1109 ccw_driver_register (struct ccw_driver *cdriver)
1110 {
1111         struct device_driver *drv = &cdriver->driver;
1112
1113         drv->bus = &ccw_bus_type;
1114         drv->name = cdriver->name;
1115         drv->probe = ccw_device_probe;
1116         drv->remove = ccw_device_remove;
1117
1118         return driver_register(drv);
1119 }
1120
1121 void
1122 ccw_driver_unregister (struct ccw_driver *cdriver)
1123 {
1124         driver_unregister(&cdriver->driver);
1125 }
1126
1127 MODULE_LICENSE("GPL");
1128 EXPORT_SYMBOL(ccw_device_set_online);
1129 EXPORT_SYMBOL(ccw_device_set_offline);
1130 EXPORT_SYMBOL(ccw_driver_register);
1131 EXPORT_SYMBOL(ccw_driver_unregister);
1132 EXPORT_SYMBOL(get_ccwdev_by_busid);
1133 EXPORT_SYMBOL(ccw_bus_type);
1134 EXPORT_SYMBOL(ccw_device_work);
1135 EXPORT_SYMBOL(ccw_device_notify_work);