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 #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_hotplug (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         .hotplug = &ccw_hotplug,
 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_compare_and_swap(0, 1, &cdev->private->onoff))
 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         struct ccw_device * sibling;
 540 };
 541
 542 static int
 543 match_devno(struct device * dev, void * data)
 544 {
 545         struct match_data * d = (struct match_data *)data;
 546         struct ccw_device * cdev;
 547
 548         cdev = to_ccwdev(dev);
 549         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 550             (cdev->private->devno == d->devno) &&
 551             (cdev != d->sibling)) {
 552                 cdev->private->state = DEV_STATE_NOT_OPER;
 553                 return 1;
 554         }
 555         return 0;
 556 }
 557
 558 static struct ccw_device *
 559 get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
 560 {
 561         struct device *dev;
 562         struct match_data data = {
 563                 .devno  = devno,
 564                 .sibling = sibling,
 565         };
 566
 567         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 568
 569         return dev ? to_ccwdev(dev) : NULL;
 570 }
 571
 572 static void
 573 ccw_device_add_changed(void *data)
 574 {
 575
 576         struct ccw_device *cdev;
 577
 578         cdev = (struct ccw_device *)data;
 579         if (device_add(&cdev->dev)) {
 580                 put_device(&cdev->dev);
 581                 return;
 582         }
 583         set_bit(1, &cdev->private->registered);
 584         if (device_add_files(&cdev->dev)) {
 585                 if (test_and_clear_bit(1, &cdev->private->registered))
 586                         device_unregister(&cdev->dev);
 587         }
 588 }
 589
 590 extern int css_get_ssd_info(struct subchannel *sch);
 591
 592 void
 593 ccw_device_do_unreg_rereg(void *data)
 594 {
 595         struct ccw_device *cdev;
 596         struct subchannel *sch;
 597         int need_rename;
 598
 599         cdev = (struct ccw_device *)data;
 600         sch = to_subchannel(cdev->dev.parent);
 601         if (cdev->private->devno != sch->schib.pmcw.dev) {
 602                 /*
 603                  * The device number has changed. This is usually only when
 604                  * a device has been detached under VM and then re-appeared
 605                  * on another subchannel because of a different attachment
 606                  * order than before. Ideally, we should should just switch
 607                  * subchannels, but unfortunately, this is not possible with
 608                  * the current implementation.
 609                  * Instead, we search for the old subchannel for this device
 610                  * number and deregister so there are no collisions with the
 611                  * newly registered ccw_device.
 612                  * FIXME: Find another solution so the block layer doesn't
 613                  *        get possibly sick...
 614                  */
 615                 struct ccw_device *other_cdev;
 616
 617                 need_rename = 1;
 618                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 619                                                       cdev);
 620                 if (other_cdev) {
 621                         struct subchannel *other_sch;
 622
 623                         other_sch = to_subchannel(other_cdev->dev.parent);
 624                         if (get_device(&other_sch->dev)) {
 625                                 stsch(other_sch->irq, &other_sch->schib);
 626                                 if (other_sch->schib.pmcw.dnv) {
 627                                         other_sch->schib.pmcw.intparm = 0;
 628                                         cio_modify(other_sch);
 629                                 }
 630                                 device_unregister(&other_sch->dev);
 631                         }
 632                 }
 633                 /* Update ssd info here. */
 634                 css_get_ssd_info(sch);
 635                 cdev->private->devno = sch->schib.pmcw.dev;
 636         } else
 637                 need_rename = 0;
 638         device_remove_files(&cdev->dev);
 639         if (test_and_clear_bit(1, &cdev->private->registered))
 640                 device_del(&cdev->dev);
 641         if (need_rename)
 642                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 643                           sch->schib.pmcw.dev);
 644         PREPARE_WORK(&cdev->private->kick_work,
 645                      ccw_device_add_changed, (void *)cdev);
 646         queue_work(ccw_device_work, &cdev->private->kick_work);
 647 }
 648
 649 static void
 650 ccw_device_release(struct device *dev)
 651 {
 652         struct ccw_device *cdev;
 653
 654         cdev = to_ccwdev(dev);
 655         kfree(cdev->private);
 656         kfree(cdev);
 657 }
 658
 659 /*
 660  * Register recognized device.
 661  */
 662 static void
 663 io_subchannel_register(void *data)
 664 {
 665         struct ccw_device *cdev;
 666         struct subchannel *sch;
 667         int ret;
 668         unsigned long flags;
 669
 670         cdev = (struct ccw_device *) data;
 671         sch = to_subchannel(cdev->dev.parent);
 672
 673         if (klist_node_attached(&cdev->dev.knode_parent)) {
 674                 bus_rescan_devices(&ccw_bus_type);
 675                 goto out;
 676         }
 677         /* make it known to the system */
 678         ret = ccw_device_register(cdev);
 679         if (ret) {
 680                 printk (KERN_WARNING "%s: could not register %s\n",
 681                         __func__, cdev->dev.bus_id);
 682                 put_device(&cdev->dev);
 683                 spin_lock_irqsave(&sch->lock, flags);
 684                 sch->dev.driver_data = NULL;
 685                 spin_unlock_irqrestore(&sch->lock, flags);
 686                 kfree (cdev->private);
 687                 kfree (cdev);
 688                 put_device(&sch->dev);
 689                 if (atomic_dec_and_test(&ccw_device_init_count))
 690                         wake_up(&ccw_device_init_wq);
 691                 return;
 692         }
 693
 694         ret = subchannel_add_files(cdev->dev.parent);
 695         if (ret)
 696                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 697                        __func__, sch->dev.bus_id);
 698         put_device(&cdev->dev);
 699 out:
 700         cdev->private->flags.recog_done = 1;
 701         put_device(&sch->dev);
 702         wake_up(&cdev->private->wait_q);
 703         if (atomic_dec_and_test(&ccw_device_init_count))
 704                 wake_up(&ccw_device_init_wq);
 705 }
 706
 707 void
 708 ccw_device_call_sch_unregister(void *data)
 709 {
 710         struct ccw_device *cdev = data;
 711         struct subchannel *sch;
 712
 713         sch = to_subchannel(cdev->dev.parent);
 714         device_unregister(&sch->dev);
 715         /* Reset intparm to zeroes. */
 716         sch->schib.pmcw.intparm = 0;
 717         cio_modify(sch);
 718         put_device(&cdev->dev);
 719         put_device(&sch->dev);
 720 }
 721
 722 /*
 723  * subchannel recognition done. Called from the state machine.
 724  */
 725 void
 726 io_subchannel_recog_done(struct ccw_device *cdev)
 727 {
 728         struct subchannel *sch;
 729
 730         if (css_init_done == 0) {
 731                 cdev->private->flags.recog_done = 1;
 732                 return;
 733         }
 734         switch (cdev->private->state) {
 735         case DEV_STATE_NOT_OPER:
 736                 cdev->private->flags.recog_done = 1;
 737                 /* Remove device found not operational. */
 738                 if (!get_device(&cdev->dev))
 739                         break;
 740                 sch = to_subchannel(cdev->dev.parent);
 741                 PREPARE_WORK(&cdev->private->kick_work,
 742                              ccw_device_call_sch_unregister, (void *) cdev);
 743                 queue_work(slow_path_wq, &cdev->private->kick_work);
 744                 if (atomic_dec_and_test(&ccw_device_init_count))
 745                         wake_up(&ccw_device_init_wq);
 746                 break;
 747         case DEV_STATE_BOXED:
 748                 /* Device did not respond in time. */
 749         case DEV_STATE_OFFLINE:
 750                 /*
 751                  * We can't register the device in interrupt context so
 752                  * we schedule a work item.
 753                  */
 754                 if (!get_device(&cdev->dev))
 755                         break;
 756                 PREPARE_WORK(&cdev->private->kick_work,
 757                              io_subchannel_register, (void *) cdev);
 758                 queue_work(slow_path_wq, &cdev->private->kick_work);
 759                 break;
 760         }
 761 }
 762
 763 static int
 764 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 765 {
 766         int rc;
 767         struct ccw_device_private *priv;
 768
 769         sch->dev.driver_data = cdev;
 770         sch->driver = &io_subchannel_driver;
 771         cdev->ccwlock = &sch->lock;
 772         /* Init private data. */
 773         priv = cdev->private;
 774         priv->devno = sch->schib.pmcw.dev;
 775         priv->irq = sch->irq;
 776         priv->state = DEV_STATE_NOT_OPER;
 777         INIT_LIST_HEAD(&priv->cmb_list);
 778         init_waitqueue_head(&priv->wait_q);
 779         init_timer(&priv->timer);
 780
 781         /* Set an initial name for the device. */
 782         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
 783                   sch->schib.pmcw.dev);
 784
 785         /* Increase counter of devices currently in recognition. */
 786         atomic_inc(&ccw_device_init_count);
 787
 788         /* Start async. device sensing. */
 789         spin_lock_irq(&sch->lock);
 790         rc = ccw_device_recognition(cdev);
 791         spin_unlock_irq(&sch->lock);
 792         if (rc) {
 793                 if (atomic_dec_and_test(&ccw_device_init_count))
 794                         wake_up(&ccw_device_init_wq);
 795         }
 796         return rc;
 797 }
 798
 799 static int
 800 io_subchannel_probe (struct device *pdev)
 801 {
 802         struct subchannel *sch;
 803         struct ccw_device *cdev;
 804         int rc;
 805         unsigned long flags;
 806
 807         sch = to_subchannel(pdev);
 808         if (sch->dev.driver_data) {
 809                 /*
 810                  * This subchannel already has an associated ccw_device.
 811                  * Register it and exit. This happens for all early
 812                  * device, e.g. the console.
 813                  */
 814                 cdev = sch->dev.driver_data;
 815                 device_initialize(&cdev->dev);
 816                 ccw_device_register(cdev);
 817                 subchannel_add_files(&sch->dev);
 818                 /*
 819                  * Check if the device is already online. If it is
 820                  * the reference count needs to be corrected
 821                  * (see ccw_device_online and css_init_done for the
 822                  * ugly details).
 823                  */
 824                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 825                     cdev->private->state != DEV_STATE_OFFLINE &&
 826                     cdev->private->state != DEV_STATE_BOXED)
 827                         get_device(&cdev->dev);
 828                 return 0;
 829         }
 830         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
 831         if (!cdev)
 832                 return -ENOMEM;
 833         memset(cdev, 0, sizeof(struct ccw_device));
 834         cdev->private = kmalloc(sizeof(struct ccw_device_private),
 835                                 GFP_KERNEL | GFP_DMA);
 836         if (!cdev->private) {
 837                 kfree(cdev);
 838                 return -ENOMEM;
 839         }
 840         memset(cdev->private, 0, sizeof(struct ccw_device_private));
 841         atomic_set(&cdev->private->onoff, 0);
 842         cdev->dev = (struct device) {
 843                 .parent = pdev,
 844                 .release = ccw_device_release,
 845         };
 846         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 847         /* Do first half of device_register. */
 848         device_initialize(&cdev->dev);
 849
 850         if (!get_device(&sch->dev)) {
 851                 if (cdev->dev.release)
 852                         cdev->dev.release(&cdev->dev);
 853                 return -ENODEV;
 854         }
 855
 856         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
 857         if (rc) {
 858                 spin_lock_irqsave(&sch->lock, flags);
 859                 sch->dev.driver_data = NULL;
 860                 spin_unlock_irqrestore(&sch->lock, flags);
 861                 if (cdev->dev.release)
 862                         cdev->dev.release(&cdev->dev);
 863         }
 864
 865         return rc;
 866 }
 867
 868 static void
 869 ccw_device_unregister(void *data)
 870 {
 871         struct ccw_device *cdev;
 872
 873         cdev = (struct ccw_device *)data;
 874         if (test_and_clear_bit(1, &cdev->private->registered))
 875                 device_unregister(&cdev->dev);
 876         put_device(&cdev->dev);
 877 }
 878
 879 static int
 880 io_subchannel_remove (struct device *dev)
 881 {
 882         struct ccw_device *cdev;
 883         unsigned long flags;
 884
 885         if (!dev->driver_data)
 886                 return 0;
 887         cdev = dev->driver_data;
 888         /* Set ccw device to not operational and drop reference. */
 889         spin_lock_irqsave(cdev->ccwlock, flags);
 890         dev->driver_data = NULL;
 891         cdev->private->state = DEV_STATE_NOT_OPER;
 892         spin_unlock_irqrestore(cdev->ccwlock, flags);
 893         /*
 894          * Put unregistration on workqueue to avoid livelocks on the css bus
 895          * semaphore.
 896          */
 897         if (get_device(&cdev->dev)) {
 898                 PREPARE_WORK(&cdev->private->kick_work,
 899                              ccw_device_unregister, (void *) cdev);
 900                 queue_work(ccw_device_work, &cdev->private->kick_work);
 901         }
 902         return 0;
 903 }
 904
 905 static int
 906 io_subchannel_notify(struct device *dev, int event)
 907 {
 908         struct ccw_device *cdev;
 909
 910         cdev = dev->driver_data;
 911         if (!cdev)
 912                 return 0;
 913         if (!cdev->drv)
 914                 return 0;
 915         if (!cdev->online)
 916                 return 0;
 917         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 918 }
 919
 920 static void
 921 io_subchannel_verify(struct device *dev)
 922 {
 923         struct ccw_device *cdev;
 924
 925         cdev = dev->driver_data;
 926         if (cdev)
 927                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 928 }
 929
 930 static void
 931 io_subchannel_ioterm(struct device *dev)
 932 {
 933         struct ccw_device *cdev;
 934
 935         cdev = dev->driver_data;
 936         if (!cdev)
 937                 return;
 938         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 939         if (cdev->handler)
 940                 cdev->handler(cdev, cdev->private->intparm,
 941                               ERR_PTR(-EIO));
 942 }
 943
 944 static void
 945 io_subchannel_shutdown(struct device *dev)
 946 {
 947         struct subchannel *sch;
 948         struct ccw_device *cdev;
 949         int ret;
 950
 951         sch = to_subchannel(dev);
 952         cdev = dev->driver_data;
 953
 954         if (cio_is_console(sch->irq))
 955                 return;
 956         if (!sch->schib.pmcw.ena)
 957                 /* Nothing to do. */
 958                 return;
 959         ret = cio_disable_subchannel(sch);
 960         if (ret != -EBUSY)
 961                 /* Subchannel is disabled, we're done. */
 962                 return;
 963         cdev->private->state = DEV_STATE_QUIESCE;
 964         if (cdev->handler)
 965                 cdev->handler(cdev, cdev->private->intparm,
 966                               ERR_PTR(-EIO));
 967         ret = ccw_device_cancel_halt_clear(cdev);
 968         if (ret == -EBUSY) {
 969                 ccw_device_set_timeout(cdev, HZ/10);
 970                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 971         }
 972         cio_disable_subchannel(sch);
 973 }
 974
 975 #ifdef CONFIG_CCW_CONSOLE
 976 static struct ccw_device console_cdev;
 977 static struct ccw_device_private console_private;
 978 static int console_cdev_in_use;
 979
 980 static int
 981 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 982 {
 983         int rc;
 984
 985         /* Initialize the ccw_device structure. */
 986         cdev->dev = (struct device) {
 987                 .parent = &sch->dev,
 988         };
 989         /* Initialize the subchannel structure */
 990         sch->dev.parent = &css_bus_device;
 991         sch->dev.bus = &css_bus_type;
 992
 993         rc = io_subchannel_recog(cdev, sch);
 994         if (rc)
 995                 return rc;
 996
 997         /* Now wait for the async. recognition to come to an end. */
 998         spin_lock_irq(cdev->ccwlock);
 999         while (!dev_fsm_final_state(cdev))
1000                 wait_cons_dev();
1001         rc = -EIO;
1002         if (cdev->private->state != DEV_STATE_OFFLINE)
1003                 goto out_unlock;
1004         ccw_device_online(cdev);
1005         while (!dev_fsm_final_state(cdev))
1006                 wait_cons_dev();
1007         if (cdev->private->state != DEV_STATE_ONLINE)
1008                 goto out_unlock;
1009         rc = 0;
1010 out_unlock:
1011         spin_unlock_irq(cdev->ccwlock);
1012         return 0;
1013 }
1014
1015 struct ccw_device *
1016 ccw_device_probe_console(void)
1017 {
1018         struct subchannel *sch;
1019         int ret;
1020
1021         if (xchg(&console_cdev_in_use, 1) != 0)
1022                 return NULL;
1023         sch = cio_probe_console();
1024         if (IS_ERR(sch)) {
1025                 console_cdev_in_use = 0;
1026                 return (void *) sch;
1027         }
1028         memset(&console_cdev, 0, sizeof(struct ccw_device));
1029         memset(&console_private, 0, sizeof(struct ccw_device_private));
1030         console_cdev.private = &console_private;
1031         ret = ccw_device_console_enable(&console_cdev, sch);
1032         if (ret) {
1033                 cio_release_console();
1034                 console_cdev_in_use = 0;
1035                 return ERR_PTR(ret);
1036         }
1037         console_cdev.online = 1;
1038         return &console_cdev;
1039 }
1040 #endif
1041
1042 /*
1043  * get ccw_device matching the busid, but only if owned by cdrv
1044  */
1045 static int
1046 __ccwdev_check_busid(struct device *dev, void *id)
1047 {
1048         char *bus_id;
1049
1050         bus_id = (char *)id;
1051
1052         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1053 }
1054
1055
1056 struct ccw_device *
1057 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1058 {
1059         struct device *dev;
1060         struct device_driver *drv;
1061
1062         drv = get_driver(&cdrv->driver);
1063         if (!drv)
1064                 return NULL;
1065
1066         dev = driver_find_device(drv, NULL, (void *)bus_id,
1067                                  __ccwdev_check_busid);
1068         put_driver(drv);
1069
1070         return dev ? to_ccwdev(dev) : 0;
1071 }
1072
1073 /************************** device driver handling ************************/
1074
1075 /* This is the implementation of the ccw_driver class. The probe, remove
1076  * and release methods are initially very similar to the device_driver
1077  * implementations, with the difference that they have ccw_device
1078  * arguments.
1079  *
1080  * A ccw driver also contains the information that is needed for
1081  * device matching.
1082  */
1083 static int
1084 ccw_device_probe (struct device *dev)
1085 {
1086         struct ccw_device *cdev = to_ccwdev(dev);
1087         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1088         int ret;
1089
1090         cdev->drv = cdrv; /* to let the driver call _set_online */
1091
1092         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1093
1094         if (ret) {
1095                 cdev->drv = 0;
1096                 return ret;
1097         }
1098
1099         return 0;
1100 }
1101
1102 static int
1103 ccw_device_remove (struct device *dev)
1104 {
1105         struct ccw_device *cdev = to_ccwdev(dev);
1106         struct ccw_driver *cdrv = cdev->drv;
1107         int ret;
1108
1109         pr_debug("removing device %s\n", cdev->dev.bus_id);
1110         if (cdrv->remove)
1111                 cdrv->remove(cdev);
1112         if (cdev->online) {
1113                 cdev->online = 0;
1114                 spin_lock_irq(cdev->ccwlock);
1115                 ret = ccw_device_offline(cdev);
1116                 spin_unlock_irq(cdev->ccwlock);
1117                 if (ret == 0)
1118                         wait_event(cdev->private->wait_q,
1119                                    dev_fsm_final_state(cdev));
1120                 else
1121                         //FIXME: we can't fail!
1122                         pr_debug("ccw_device_offline returned %d, device %s\n",
1123                                  ret, cdev->dev.bus_id);
1124         }
1125         ccw_device_set_timeout(cdev, 0);
1126         cdev->drv = 0;
1127         return 0;
1128 }
1129
1130 int
1131 ccw_driver_register (struct ccw_driver *cdriver)
1132 {
1133         struct device_driver *drv = &cdriver->driver;
1134
1135         drv->bus = &ccw_bus_type;
1136         drv->name = cdriver->name;
1137         drv->probe = ccw_device_probe;
1138         drv->remove = ccw_device_remove;
1139
1140         return driver_register(drv);
1141 }
1142
1143 void
1144 ccw_driver_unregister (struct ccw_driver *cdriver)
1145 {
1146         driver_unregister(&cdriver->driver);
1147 }
1148
1149 MODULE_LICENSE("GPL");
1150 EXPORT_SYMBOL(ccw_device_set_online);
1151 EXPORT_SYMBOL(ccw_device_set_offline);
1152 EXPORT_SYMBOL(ccw_driver_register);
1153 EXPORT_SYMBOL(ccw_driver_unregister);
1154 EXPORT_SYMBOL(get_ccwdev_by_busid);
1155 EXPORT_SYMBOL(ccw_bus_type);
1156 EXPORT_SYMBOL(ccw_device_work);
1157 EXPORT_SYMBOL(ccw_device_notify_work);