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