drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   6  *                       IBM Corporation
   7  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/errno.h>
  15 #include <linux/err.h>
  16 #include <linux/slab.h>
  17 #include <linux/list.h>
  18 #include <linux/device.h>
  19 #include <linux/workqueue.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24
  25 #include "cio.h"
  26 #include "css.h"
  27 #include "device.h"
  28 #include "ioasm.h"
  29
  30 /******************* bus type handling ***********************/
  31
  32 /* The Linux driver model distinguishes between a bus type and
  33  * the bus itself. Of course we only have one channel
  34  * subsystem driver and one channel system per machine, but
  35  * we still use the abstraction. T.R. says it's a good idea. */
  36 static int
  37 ccw_bus_match (struct device * dev, struct device_driver * drv)
  38 {
  39         struct ccw_device *cdev = to_ccwdev(dev);
  40         struct ccw_driver *cdrv = to_ccwdrv(drv);
  41         const struct ccw_device_id *ids = cdrv->ids, *found;
  42
  43         if (!ids)
  44                 return 0;
  45
  46         found = ccw_device_id_match(ids, &cdev->id);
  47         if (!found)
  48                 return 0;
  49
  50         cdev->id.driver_info = found->driver_info;
  51
  52         return 1;
  53 }
  54
  55 /* Store modalias string delimited by prefix/suffix string into buffer with
  56  * specified size. Return length of resulting string (excluding trailing '\0')
  57  * even if string doesn't fit buffer (snprintf semantics). */
  58 static int snprint_alias(char *buf, size_t size, const char *prefix,
  59                          struct ccw_device_id *id, const char *suffix)
  60 {
  61         int len;
  62
  63         len = snprintf(buf, size, "%sccw:t%04Xm%02X", prefix, id->cu_type,
  64                        id->cu_model);
  65         if (len > size)
  66                 return len;
  67         buf += len;
  68         size -= len;
  69
  70         if (id->dev_type != 0)
  71                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  72                                 id->dev_model, suffix);
  73         else
  74                 len += snprintf(buf, size, "dtdm%s", suffix);
  75
  76         return len;
  77 }
  78
  79 /* Set up environment variables for ccw device uevent. Return 0 on success,
  80  * non-zero otherwise. */
  81 static int ccw_uevent(struct device *dev, char **envp, int num_envp,
  82                       char *buffer, int buffer_size)
  83 {
  84         struct ccw_device *cdev = to_ccwdev(dev);
  85         struct ccw_device_id *id = &(cdev->id);
  86         int i = 0;
  87         int len;
  88
  89         /* CU_TYPE= */
  90         len = snprintf(buffer, buffer_size, "CU_TYPE=%04X", id->cu_type) + 1;
  91         if (len > buffer_size || i >= num_envp)
  92                 return -ENOMEM;
  93         envp[i++] = buffer;
  94         buffer += len;
  95         buffer_size -= len;
  96
  97         /* CU_MODEL= */
  98         len = snprintf(buffer, buffer_size, "CU_MODEL=%02X", id->cu_model) + 1;
  99         if (len > buffer_size || i >= num_envp)
 100                 return -ENOMEM;
 101         envp[i++] = buffer;
 102         buffer += len;
 103         buffer_size -= len;
 104
 105         /* The next two can be zero, that's ok for us */
 106         /* DEV_TYPE= */
 107         len = snprintf(buffer, buffer_size, "DEV_TYPE=%04X", id->dev_type) + 1;
 108         if (len > buffer_size || i >= num_envp)
 109                 return -ENOMEM;
 110         envp[i++] = buffer;
 111         buffer += len;
 112         buffer_size -= len;
 113
 114         /* DEV_MODEL= */
 115         len = snprintf(buffer, buffer_size, "DEV_MODEL=%02X",
 116                         (unsigned char) id->dev_model) + 1;
 117         if (len > buffer_size || i >= num_envp)
 118                 return -ENOMEM;
 119         envp[i++] = buffer;
 120         buffer += len;
 121         buffer_size -= len;
 122
 123         /* MODALIAS=  */
 124         len = snprint_alias(buffer, buffer_size, "MODALIAS=", id, "") + 1;
 125         if (len > buffer_size || i >= num_envp)
 126                 return -ENOMEM;
 127         envp[i++] = buffer;
 128         buffer += len;
 129         buffer_size -= len;
 130
 131         envp[i] = NULL;
 132
 133         return 0;
 134 }
 135
 136 struct bus_type ccw_bus_type;
 137
 138 static int io_subchannel_probe (struct subchannel *);
 139 static int io_subchannel_remove (struct subchannel *);
 140 void io_subchannel_irq (struct device *);
 141 static int io_subchannel_notify(struct device *, int);
 142 static void io_subchannel_verify(struct device *);
 143 static void io_subchannel_ioterm(struct device *);
 144 static void io_subchannel_shutdown(struct subchannel *);
 145
 146 struct css_driver io_subchannel_driver = {
 147         .subchannel_type = SUBCHANNEL_TYPE_IO,
 148         .drv = {
 149                 .name = "io_subchannel",
 150                 .bus  = &css_bus_type,
 151         },
 152         .irq = io_subchannel_irq,
 153         .notify = io_subchannel_notify,
 154         .verify = io_subchannel_verify,
 155         .termination = io_subchannel_ioterm,
 156         .probe = io_subchannel_probe,
 157         .remove = io_subchannel_remove,
 158         .shutdown = io_subchannel_shutdown,
 159 };
 160
 161 struct workqueue_struct *ccw_device_work;
 162 struct workqueue_struct *ccw_device_notify_work;
 163 wait_queue_head_t ccw_device_init_wq;
 164 atomic_t ccw_device_init_count;
 165
 166 static int __init
 167 init_ccw_bus_type (void)
 168 {
 169         int ret;
 170
 171         init_waitqueue_head(&ccw_device_init_wq);
 172         atomic_set(&ccw_device_init_count, 0);
 173
 174         ccw_device_work = create_singlethread_workqueue("cio");
 175         if (!ccw_device_work)
 176                 return -ENOMEM; /* FIXME: better errno ? */
 177         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 178         if (!ccw_device_notify_work) {
 179                 ret = -ENOMEM; /* FIXME: better errno ? */
 180                 goto out_err;
 181         }
 182         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 183         if (!slow_path_wq) {
 184                 ret = -ENOMEM; /* FIXME: better errno ? */
 185                 goto out_err;
 186         }
 187         if ((ret = bus_register (&ccw_bus_type)))
 188                 goto out_err;
 189
 190         if ((ret = driver_register(&io_subchannel_driver.drv)))
 191                 goto out_err;
 192
 193         wait_event(ccw_device_init_wq,
 194                    atomic_read(&ccw_device_init_count) == 0);
 195         flush_workqueue(ccw_device_work);
 196         return 0;
 197 out_err:
 198         if (ccw_device_work)
 199                 destroy_workqueue(ccw_device_work);
 200         if (ccw_device_notify_work)
 201                 destroy_workqueue(ccw_device_notify_work);
 202         if (slow_path_wq)
 203                 destroy_workqueue(slow_path_wq);
 204         return ret;
 205 }
 206
 207 static void __exit
 208 cleanup_ccw_bus_type (void)
 209 {
 210         driver_unregister(&io_subchannel_driver.drv);
 211         bus_unregister(&ccw_bus_type);
 212         destroy_workqueue(ccw_device_notify_work);
 213         destroy_workqueue(ccw_device_work);
 214 }
 215
 216 subsys_initcall(init_ccw_bus_type);
 217 module_exit(cleanup_ccw_bus_type);
 218
 219 /************************ device handling **************************/
 220
 221 /*
 222  * A ccw_device has some interfaces in sysfs in addition to the
 223  * standard ones.
 224  * The following entries are designed to export the information which
 225  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 226  * are obvious, so they don't have an entry :)
 227  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 228  */
 229 static ssize_t
 230 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 231 {
 232         struct subchannel *sch = to_subchannel(dev);
 233         struct ssd_info *ssd = &sch->ssd_info;
 234         ssize_t ret = 0;
 235         int chp;
 236
 237         for (chp = 0; chp < 8; chp++)
 238                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 239
 240         ret += sprintf (buf+ret, "\n");
 241         return min((ssize_t)PAGE_SIZE, ret);
 242 }
 243
 244 static ssize_t
 245 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 246 {
 247         struct subchannel *sch = to_subchannel(dev);
 248         struct pmcw *pmcw = &sch->schib.pmcw;
 249
 250         return sprintf (buf, "%02x %02x %02x\n",
 251                         pmcw->pim, pmcw->pam, pmcw->pom);
 252 }
 253
 254 static ssize_t
 255 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 256 {
 257         struct ccw_device *cdev = to_ccwdev(dev);
 258         struct ccw_device_id *id = &(cdev->id);
 259
 260         if (id->dev_type != 0)
 261                 return sprintf(buf, "%04x/%02x\n",
 262                                 id->dev_type, id->dev_model);
 263         else
 264                 return sprintf(buf, "n/a\n");
 265 }
 266
 267 static ssize_t
 268 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 269 {
 270         struct ccw_device *cdev = to_ccwdev(dev);
 271         struct ccw_device_id *id = &(cdev->id);
 272
 273         return sprintf(buf, "%04x/%02x\n",
 274                        id->cu_type, id->cu_model);
 275 }
 276
 277 static ssize_t
 278 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 279 {
 280         struct ccw_device *cdev = to_ccwdev(dev);
 281         struct ccw_device_id *id = &(cdev->id);
 282         int len;
 283
 284         len = snprint_alias(buf, PAGE_SIZE, "", id, "\n") + 1;
 285
 286         return len > PAGE_SIZE ? PAGE_SIZE : len;
 287 }
 288
 289 static ssize_t
 290 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 291 {
 292         struct ccw_device *cdev = to_ccwdev(dev);
 293
 294         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 295 }
 296
 297 static void
 298 ccw_device_remove_disconnected(struct ccw_device *cdev)
 299 {
 300         struct subchannel *sch;
 301         /*
 302          * Forced offline in disconnected state means
 303          * 'throw away device'.
 304          */
 305         sch = to_subchannel(cdev->dev.parent);
 306         css_sch_device_unregister(sch);
 307         /* Reset intparm to zeroes. */
 308         sch->schib.pmcw.intparm = 0;
 309         cio_modify(sch);
 310         put_device(&sch->dev);
 311 }
 312
 313 int
 314 ccw_device_set_offline(struct ccw_device *cdev)
 315 {
 316         int ret;
 317
 318         if (!cdev)
 319                 return -ENODEV;
 320         if (!cdev->online || !cdev->drv)
 321                 return -EINVAL;
 322
 323         if (cdev->drv->set_offline) {
 324                 ret = cdev->drv->set_offline(cdev);
 325                 if (ret != 0)
 326                         return ret;
 327         }
 328         cdev->online = 0;
 329         spin_lock_irq(cdev->ccwlock);
 330         ret = ccw_device_offline(cdev);
 331         if (ret == -ENODEV) {
 332                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 333                         cdev->private->state = DEV_STATE_OFFLINE;
 334                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 335                 }
 336                 spin_unlock_irq(cdev->ccwlock);
 337                 return ret;
 338         }
 339         spin_unlock_irq(cdev->ccwlock);
 340         if (ret == 0)
 341                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 342         else {
 343                 pr_debug("ccw_device_offline returned %d, device %s\n",
 344                          ret, cdev->dev.bus_id);
 345                 cdev->online = 1;
 346         }
 347         return ret;
 348 }
 349
 350 int
 351 ccw_device_set_online(struct ccw_device *cdev)
 352 {
 353         int ret;
 354
 355         if (!cdev)
 356                 return -ENODEV;
 357         if (cdev->online || !cdev->drv)
 358                 return -EINVAL;
 359
 360         spin_lock_irq(cdev->ccwlock);
 361         ret = ccw_device_online(cdev);
 362         spin_unlock_irq(cdev->ccwlock);
 363         if (ret == 0)
 364                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 365         else {
 366                 pr_debug("ccw_device_online returned %d, device %s\n",
 367                          ret, cdev->dev.bus_id);
 368                 return ret;
 369         }
 370         if (cdev->private->state != DEV_STATE_ONLINE)
 371                 return -ENODEV;
 372         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 373                 cdev->online = 1;
 374                 return 0;
 375         }
 376         spin_lock_irq(cdev->ccwlock);
 377         ret = ccw_device_offline(cdev);
 378         spin_unlock_irq(cdev->ccwlock);
 379         if (ret == 0)
 380                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 381         else
 382                 pr_debug("ccw_device_offline returned %d, device %s\n",
 383                          ret, cdev->dev.bus_id);
 384         return (ret == 0) ? -ENODEV : ret;
 385 }
 386
 387 static ssize_t
 388 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 389 {
 390         struct ccw_device *cdev = to_ccwdev(dev);
 391         int i, force, ret;
 392         char *tmp;
 393
 394         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 395                 return -EAGAIN;
 396
 397         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 398                 atomic_set(&cdev->private->onoff, 0);
 399                 return -EINVAL;
 400         }
 401         if (!strncmp(buf, "force\n", count)) {
 402                 force = 1;
 403                 i = 1;
 404         } else {
 405                 force = 0;
 406                 i = simple_strtoul(buf, &tmp, 16);
 407         }
 408         if (i == 1) {
 409                 /* Do device recognition, if needed. */
 410                 if (cdev->id.cu_type == 0) {
 411                         ret = ccw_device_recognition(cdev);
 412                         if (ret) {
 413                                 printk(KERN_WARNING"Couldn't start recognition "
 414                                        "for device %s (ret=%d)\n",
 415                                        cdev->dev.bus_id, ret);
 416                                 goto out;
 417                         }
 418                         wait_event(cdev->private->wait_q,
 419                                    cdev->private->flags.recog_done);
 420                 }
 421                 if (cdev->drv && cdev->drv->set_online)
 422                         ccw_device_set_online(cdev);
 423         } else if (i == 0) {
 424                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 425                         ccw_device_remove_disconnected(cdev);
 426                 else if (cdev->drv && cdev->drv->set_offline)
 427                         ccw_device_set_offline(cdev);
 428         }
 429         if (force && cdev->private->state == DEV_STATE_BOXED) {
 430                 ret = ccw_device_stlck(cdev);
 431                 if (ret) {
 432                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 433                                "returned %d!\n", cdev->dev.bus_id, ret);
 434                         goto out;
 435                 }
 436                 /* Do device recognition, if needed. */
 437                 if (cdev->id.cu_type == 0) {
 438                         cdev->private->state = DEV_STATE_NOT_OPER;
 439                         ret = ccw_device_recognition(cdev);
 440                         if (ret) {
 441                                 printk(KERN_WARNING"Couldn't start recognition "
 442                                        "for device %s (ret=%d)\n",
 443                                        cdev->dev.bus_id, ret);
 444                                 goto out;
 445                         }
 446                         wait_event(cdev->private->wait_q,
 447                                    cdev->private->flags.recog_done);
 448                 }
 449                 if (cdev->drv && cdev->drv->set_online)
 450                         ccw_device_set_online(cdev);
 451         }
 452         out:
 453         if (cdev->drv)
 454                 module_put(cdev->drv->owner);
 455         atomic_set(&cdev->private->onoff, 0);
 456         return count;
 457 }
 458
 459 static ssize_t
 460 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 461 {
 462         struct ccw_device *cdev = to_ccwdev(dev);
 463         struct subchannel *sch;
 464
 465         switch (cdev->private->state) {
 466         case DEV_STATE_BOXED:
 467                 return sprintf(buf, "boxed\n");
 468         case DEV_STATE_DISCONNECTED:
 469         case DEV_STATE_DISCONNECTED_SENSE_ID:
 470         case DEV_STATE_NOT_OPER:
 471                 sch = to_subchannel(dev->parent);
 472                 if (!sch->lpm)
 473                         return sprintf(buf, "no path\n");
 474                 else
 475                         return sprintf(buf, "no device\n");
 476         default:
 477                 /* All other states considered fine. */
 478                 return sprintf(buf, "good\n");
 479         }
 480 }
 481
 482 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 483 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 484 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 485 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 486 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 487 static DEVICE_ATTR(online, 0644, online_show, online_store);
 488 extern struct device_attribute dev_attr_cmb_enable;
 489 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 490
 491 static struct attribute * subch_attrs[] = {
 492         &dev_attr_chpids.attr,
 493         &dev_attr_pimpampom.attr,
 494         NULL,
 495 };
 496
 497 static struct attribute_group subch_attr_group = {
 498         .attrs = subch_attrs,
 499 };
 500
 501 static inline int
 502 subchannel_add_files (struct device *dev)
 503 {
 504         return sysfs_create_group(&dev->kobj, &subch_attr_group);
 505 }
 506
 507 static struct attribute * ccwdev_attrs[] = {
 508         &dev_attr_devtype.attr,
 509         &dev_attr_cutype.attr,
 510         &dev_attr_modalias.attr,
 511         &dev_attr_online.attr,
 512         &dev_attr_cmb_enable.attr,
 513         &dev_attr_availability.attr,
 514         NULL,
 515 };
 516
 517 static struct attribute_group ccwdev_attr_group = {
 518         .attrs = ccwdev_attrs,
 519 };
 520
 521 static inline int
 522 device_add_files (struct device *dev)
 523 {
 524         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 525 }
 526
 527 static inline void
 528 device_remove_files(struct device *dev)
 529 {
 530         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 531 }
 532
 533 /* this is a simple abstraction for device_register that sets the
 534  * correct bus type and adds the bus specific files */
 535 int
 536 ccw_device_register(struct ccw_device *cdev)
 537 {
 538         struct device *dev = &cdev->dev;
 539         int ret;
 540
 541         dev->bus = &ccw_bus_type;
 542
 543         if ((ret = device_add(dev)))
 544                 return ret;
 545
 546         set_bit(1, &cdev->private->registered);
 547         if ((ret = device_add_files(dev))) {
 548                 if (test_and_clear_bit(1, &cdev->private->registered))
 549                         device_del(dev);
 550         }
 551         return ret;
 552 }
 553
 554 struct match_data {
 555         unsigned int devno;
 556         unsigned int ssid;
 557         struct ccw_device * sibling;
 558 };
 559
 560 static int
 561 match_devno(struct device * dev, void * data)
 562 {
 563         struct match_data * d = (struct match_data *)data;
 564         struct ccw_device * cdev;
 565
 566         cdev = to_ccwdev(dev);
 567         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 568             (cdev->private->devno == d->devno) &&
 569             (cdev->private->ssid == d->ssid) &&
 570             (cdev != d->sibling)) {
 571                 cdev->private->state = DEV_STATE_NOT_OPER;
 572                 return 1;
 573         }
 574         return 0;
 575 }
 576
 577 static struct ccw_device *
 578 get_disc_ccwdev_by_devno(unsigned int devno, unsigned int ssid,
 579                          struct ccw_device *sibling)
 580 {
 581         struct device *dev;
 582         struct match_data data;
 583
 584         data.devno = devno;
 585         data.ssid = ssid;
 586         data.sibling = sibling;
 587         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 588
 589         return dev ? to_ccwdev(dev) : NULL;
 590 }
 591
 592 static void
 593 ccw_device_add_changed(void *data)
 594 {
 595
 596         struct ccw_device *cdev;
 597
 598         cdev = (struct ccw_device *)data;
 599         if (device_add(&cdev->dev)) {
 600                 put_device(&cdev->dev);
 601                 return;
 602         }
 603         set_bit(1, &cdev->private->registered);
 604         if (device_add_files(&cdev->dev)) {
 605                 if (test_and_clear_bit(1, &cdev->private->registered))
 606                         device_unregister(&cdev->dev);
 607         }
 608 }
 609
 610 extern int css_get_ssd_info(struct subchannel *sch);
 611
 612 void
 613 ccw_device_do_unreg_rereg(void *data)
 614 {
 615         struct ccw_device *cdev;
 616         struct subchannel *sch;
 617         int need_rename;
 618
 619         cdev = (struct ccw_device *)data;
 620         sch = to_subchannel(cdev->dev.parent);
 621         if (cdev->private->devno != sch->schib.pmcw.dev) {
 622                 /*
 623                  * The device number has changed. This is usually only when
 624                  * a device has been detached under VM and then re-appeared
 625                  * on another subchannel because of a different attachment
 626                  * order than before. Ideally, we should should just switch
 627                  * subchannels, but unfortunately, this is not possible with
 628                  * the current implementation.
 629                  * Instead, we search for the old subchannel for this device
 630                  * number and deregister so there are no collisions with the
 631                  * newly registered ccw_device.
 632                  * FIXME: Find another solution so the block layer doesn't
 633                  *        get possibly sick...
 634                  */
 635                 struct ccw_device *other_cdev;
 636
 637                 need_rename = 1;
 638                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
 639                                                       sch->schid.ssid, cdev);
 640                 if (other_cdev) {
 641                         struct subchannel *other_sch;
 642
 643                         other_sch = to_subchannel(other_cdev->dev.parent);
 644                         if (get_device(&other_sch->dev)) {
 645                                 stsch(other_sch->schid, &other_sch->schib);
 646                                 if (other_sch->schib.pmcw.dnv) {
 647                                         other_sch->schib.pmcw.intparm = 0;
 648                                         cio_modify(other_sch);
 649                                 }
 650                                 css_sch_device_unregister(other_sch);
 651                         }
 652                 }
 653                 /* Update ssd info here. */
 654                 css_get_ssd_info(sch);
 655                 cdev->private->devno = sch->schib.pmcw.dev;
 656         } else
 657                 need_rename = 0;
 658         device_remove_files(&cdev->dev);
 659         if (test_and_clear_bit(1, &cdev->private->registered))
 660                 device_del(&cdev->dev);
 661         if (need_rename)
 662                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 663                           sch->schid.ssid, sch->schib.pmcw.dev);
 664         PREPARE_WORK(&cdev->private->kick_work,
 665                      ccw_device_add_changed, (void *)cdev);
 666         queue_work(ccw_device_work, &cdev->private->kick_work);
 667 }
 668
 669 static void
 670 ccw_device_release(struct device *dev)
 671 {
 672         struct ccw_device *cdev;
 673
 674         cdev = to_ccwdev(dev);
 675         kfree(cdev->private);
 676         kfree(cdev);
 677 }
 678
 679 /*
 680  * Register recognized device.
 681  */
 682 static void
 683 io_subchannel_register(void *data)
 684 {
 685         struct ccw_device *cdev;
 686         struct subchannel *sch;
 687         int ret;
 688         unsigned long flags;
 689
 690         cdev = (struct ccw_device *) data;
 691         sch = to_subchannel(cdev->dev.parent);
 692
 693         if (klist_node_attached(&cdev->dev.knode_parent)) {
 694                 bus_rescan_devices(&ccw_bus_type);
 695                 goto out;
 696         }
 697         /* make it known to the system */
 698         ret = ccw_device_register(cdev);
 699         if (ret) {
 700                 printk (KERN_WARNING "%s: could not register %s\n",
 701                         __func__, cdev->dev.bus_id);
 702                 put_device(&cdev->dev);
 703                 spin_lock_irqsave(&sch->lock, flags);
 704                 sch->dev.driver_data = NULL;
 705                 spin_unlock_irqrestore(&sch->lock, flags);
 706                 kfree (cdev->private);
 707                 kfree (cdev);
 708                 put_device(&sch->dev);
 709                 if (atomic_dec_and_test(&ccw_device_init_count))
 710                         wake_up(&ccw_device_init_wq);
 711                 return;
 712         }
 713
 714         ret = subchannel_add_files(cdev->dev.parent);
 715         if (ret)
 716                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
 717                        __func__, sch->dev.bus_id);
 718         put_device(&cdev->dev);
 719 out:
 720         cdev->private->flags.recog_done = 1;
 721         put_device(&sch->dev);
 722         wake_up(&cdev->private->wait_q);
 723         if (atomic_dec_and_test(&ccw_device_init_count))
 724                 wake_up(&ccw_device_init_wq);
 725 }
 726
 727 void
 728 ccw_device_call_sch_unregister(void *data)
 729 {
 730         struct ccw_device *cdev = data;
 731         struct subchannel *sch;
 732
 733         sch = to_subchannel(cdev->dev.parent);
 734         css_sch_device_unregister(sch);
 735         /* Reset intparm to zeroes. */
 736         sch->schib.pmcw.intparm = 0;
 737         cio_modify(sch);
 738         put_device(&cdev->dev);
 739         put_device(&sch->dev);
 740 }
 741
 742 /*
 743  * subchannel recognition done. Called from the state machine.
 744  */
 745 void
 746 io_subchannel_recog_done(struct ccw_device *cdev)
 747 {
 748         struct subchannel *sch;
 749
 750         if (css_init_done == 0) {
 751                 cdev->private->flags.recog_done = 1;
 752                 return;
 753         }
 754         switch (cdev->private->state) {
 755         case DEV_STATE_NOT_OPER:
 756                 cdev->private->flags.recog_done = 1;
 757                 /* Remove device found not operational. */
 758                 if (!get_device(&cdev->dev))
 759                         break;
 760                 sch = to_subchannel(cdev->dev.parent);
 761                 PREPARE_WORK(&cdev->private->kick_work,
 762                              ccw_device_call_sch_unregister, (void *) cdev);
 763                 queue_work(slow_path_wq, &cdev->private->kick_work);
 764                 if (atomic_dec_and_test(&ccw_device_init_count))
 765                         wake_up(&ccw_device_init_wq);
 766                 break;
 767         case DEV_STATE_BOXED:
 768                 /* Device did not respond in time. */
 769         case DEV_STATE_OFFLINE:
 770                 /*
 771                  * We can't register the device in interrupt context so
 772                  * we schedule a work item.
 773                  */
 774                 if (!get_device(&cdev->dev))
 775                         break;
 776                 PREPARE_WORK(&cdev->private->kick_work,
 777                              io_subchannel_register, (void *) cdev);
 778                 queue_work(slow_path_wq, &cdev->private->kick_work);
 779                 break;
 780         }
 781 }
 782
 783 static int
 784 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 785 {
 786         int rc;
 787         struct ccw_device_private *priv;
 788
 789         sch->dev.driver_data = cdev;
 790         sch->driver = &io_subchannel_driver;
 791         cdev->ccwlock = &sch->lock;
 792
 793         /* Init private data. */
 794         priv = cdev->private;
 795         priv->devno = sch->schib.pmcw.dev;
 796         priv->ssid = sch->schid.ssid;
 797         priv->sch_no = sch->schid.sch_no;
 798         priv->state = DEV_STATE_NOT_OPER;
 799         INIT_LIST_HEAD(&priv->cmb_list);
 800         init_waitqueue_head(&priv->wait_q);
 801         init_timer(&priv->timer);
 802
 803         /* Set an initial name for the device. */
 804         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 805                   sch->schid.ssid, sch->schib.pmcw.dev);
 806
 807         /* Increase counter of devices currently in recognition. */
 808         atomic_inc(&ccw_device_init_count);
 809
 810         /* Start async. device sensing. */
 811         spin_lock_irq(&sch->lock);
 812         rc = ccw_device_recognition(cdev);
 813         spin_unlock_irq(&sch->lock);
 814         if (rc) {
 815                 if (atomic_dec_and_test(&ccw_device_init_count))
 816                         wake_up(&ccw_device_init_wq);
 817         }
 818         return rc;
 819 }
 820
 821 static int
 822 io_subchannel_probe (struct subchannel *sch)
 823 {
 824         struct ccw_device *cdev;
 825         int rc;
 826         unsigned long flags;
 827
 828         if (sch->dev.driver_data) {
 829                 /*
 830                  * This subchannel already has an associated ccw_device.
 831                  * Register it and exit. This happens for all early
 832                  * device, e.g. the console.
 833                  */
 834                 cdev = sch->dev.driver_data;
 835                 device_initialize(&cdev->dev);
 836                 ccw_device_register(cdev);
 837                 subchannel_add_files(&sch->dev);
 838                 /*
 839                  * Check if the device is already online. If it is
 840                  * the reference count needs to be corrected
 841                  * (see ccw_device_online and css_init_done for the
 842                  * ugly details).
 843                  */
 844                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
 845                     cdev->private->state != DEV_STATE_OFFLINE &&
 846                     cdev->private->state != DEV_STATE_BOXED)
 847                         get_device(&cdev->dev);
 848                 return 0;
 849         }
 850         cdev = kzalloc (sizeof(*cdev), GFP_KERNEL);
 851         if (!cdev)
 852                 return -ENOMEM;
 853         cdev->private = kzalloc(sizeof(struct ccw_device_private),
 854                                 GFP_KERNEL | GFP_DMA);
 855         if (!cdev->private) {
 856                 kfree(cdev);
 857                 return -ENOMEM;
 858         }
 859         atomic_set(&cdev->private->onoff, 0);
 860         cdev->dev.parent = &sch->dev;
 861         cdev->dev.release = ccw_device_release;
 862         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 863         /* Do first half of device_register. */
 864         device_initialize(&cdev->dev);
 865
 866         if (!get_device(&sch->dev)) {
 867                 if (cdev->dev.release)
 868                         cdev->dev.release(&cdev->dev);
 869                 return -ENODEV;
 870         }
 871
 872         rc = io_subchannel_recog(cdev, sch);
 873         if (rc) {
 874                 spin_lock_irqsave(&sch->lock, flags);
 875                 sch->dev.driver_data = NULL;
 876                 spin_unlock_irqrestore(&sch->lock, flags);
 877                 if (cdev->dev.release)
 878                         cdev->dev.release(&cdev->dev);
 879         }
 880
 881         return rc;
 882 }
 883
 884 static void
 885 ccw_device_unregister(void *data)
 886 {
 887         struct ccw_device *cdev;
 888
 889         cdev = (struct ccw_device *)data;
 890         if (test_and_clear_bit(1, &cdev->private->registered))
 891                 device_unregister(&cdev->dev);
 892         put_device(&cdev->dev);
 893 }
 894
 895 static int
 896 io_subchannel_remove (struct subchannel *sch)
 897 {
 898         struct ccw_device *cdev;
 899         unsigned long flags;
 900
 901         if (!sch->dev.driver_data)
 902                 return 0;
 903         cdev = sch->dev.driver_data;
 904         /* Set ccw device to not operational and drop reference. */
 905         spin_lock_irqsave(cdev->ccwlock, flags);
 906         sch->dev.driver_data = NULL;
 907         cdev->private->state = DEV_STATE_NOT_OPER;
 908         spin_unlock_irqrestore(cdev->ccwlock, flags);
 909         /*
 910          * Put unregistration on workqueue to avoid livelocks on the css bus
 911          * semaphore.
 912          */
 913         if (get_device(&cdev->dev)) {
 914                 PREPARE_WORK(&cdev->private->kick_work,
 915                              ccw_device_unregister, (void *) cdev);
 916                 queue_work(ccw_device_work, &cdev->private->kick_work);
 917         }
 918         return 0;
 919 }
 920
 921 static int
 922 io_subchannel_notify(struct device *dev, int event)
 923 {
 924         struct ccw_device *cdev;
 925
 926         cdev = dev->driver_data;
 927         if (!cdev)
 928                 return 0;
 929         if (!cdev->drv)
 930                 return 0;
 931         if (!cdev->online)
 932                 return 0;
 933         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 934 }
 935
 936 static void
 937 io_subchannel_verify(struct device *dev)
 938 {
 939         struct ccw_device *cdev;
 940
 941         cdev = dev->driver_data;
 942         if (cdev)
 943                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 944 }
 945
 946 static void
 947 io_subchannel_ioterm(struct device *dev)
 948 {
 949         struct ccw_device *cdev;
 950
 951         cdev = dev->driver_data;
 952         if (!cdev)
 953                 return;
 954         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
 955         if (cdev->handler)
 956                 cdev->handler(cdev, cdev->private->intparm,
 957                               ERR_PTR(-EIO));
 958 }
 959
 960 static void
 961 io_subchannel_shutdown(struct subchannel *sch)
 962 {
 963         struct ccw_device *cdev;
 964         int ret;
 965
 966         cdev = sch->dev.driver_data;
 967
 968         if (cio_is_console(sch->schid))
 969                 return;
 970         if (!sch->schib.pmcw.ena)
 971                 /* Nothing to do. */
 972                 return;
 973         ret = cio_disable_subchannel(sch);
 974         if (ret != -EBUSY)
 975                 /* Subchannel is disabled, we're done. */
 976                 return;
 977         cdev->private->state = DEV_STATE_QUIESCE;
 978         if (cdev->handler)
 979                 cdev->handler(cdev, cdev->private->intparm,
 980                               ERR_PTR(-EIO));
 981         ret = ccw_device_cancel_halt_clear(cdev);
 982         if (ret == -EBUSY) {
 983                 ccw_device_set_timeout(cdev, HZ/10);
 984                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 985         }
 986         cio_disable_subchannel(sch);
 987 }
 988
 989 #ifdef CONFIG_CCW_CONSOLE
 990 static struct ccw_device console_cdev;
 991 static struct ccw_device_private console_private;
 992 static int console_cdev_in_use;
 993
 994 static int
 995 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
 996 {
 997         int rc;
 998
 999         /* Initialize the ccw_device structure. */
1000         cdev->dev.parent= &sch->dev;
1001         rc = io_subchannel_recog(cdev, sch);
1002         if (rc)
1003                 return rc;
1004
1005         /* Now wait for the async. recognition to come to an end. */
1006         spin_lock_irq(cdev->ccwlock);
1007         while (!dev_fsm_final_state(cdev))
1008                 wait_cons_dev();
1009         rc = -EIO;
1010         if (cdev->private->state != DEV_STATE_OFFLINE)
1011                 goto out_unlock;
1012         ccw_device_online(cdev);
1013         while (!dev_fsm_final_state(cdev))
1014                 wait_cons_dev();
1015         if (cdev->private->state != DEV_STATE_ONLINE)
1016                 goto out_unlock;
1017         rc = 0;
1018 out_unlock:
1019         spin_unlock_irq(cdev->ccwlock);
1020         return 0;
1021 }
1022
1023 struct ccw_device *
1024 ccw_device_probe_console(void)
1025 {
1026         struct subchannel *sch;
1027         int ret;
1028
1029         if (xchg(&console_cdev_in_use, 1) != 0)
1030                 return ERR_PTR(-EBUSY);
1031         sch = cio_probe_console();
1032         if (IS_ERR(sch)) {
1033                 console_cdev_in_use = 0;
1034                 return (void *) sch;
1035         }
1036         memset(&console_cdev, 0, sizeof(struct ccw_device));
1037         memset(&console_private, 0, sizeof(struct ccw_device_private));
1038         console_cdev.private = &console_private;
1039         ret = ccw_device_console_enable(&console_cdev, sch);
1040         if (ret) {
1041                 cio_release_console();
1042                 console_cdev_in_use = 0;
1043                 return ERR_PTR(ret);
1044         }
1045         console_cdev.online = 1;
1046         return &console_cdev;
1047 }
1048 #endif
1049
1050 /*
1051  * get ccw_device matching the busid, but only if owned by cdrv
1052  */
1053 static int
1054 __ccwdev_check_busid(struct device *dev, void *id)
1055 {
1056         char *bus_id;
1057
1058         bus_id = (char *)id;
1059
1060         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1061 }
1062
1063
1064 struct ccw_device *
1065 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1066 {
1067         struct device *dev;
1068         struct device_driver *drv;
1069
1070         drv = get_driver(&cdrv->driver);
1071         if (!drv)
1072                 return NULL;
1073
1074         dev = driver_find_device(drv, NULL, (void *)bus_id,
1075                                  __ccwdev_check_busid);
1076         put_driver(drv);
1077
1078         return dev ? to_ccwdev(dev) : NULL;
1079 }
1080
1081 /************************** device driver handling ************************/
1082
1083 /* This is the implementation of the ccw_driver class. The probe, remove
1084  * and release methods are initially very similar to the device_driver
1085  * implementations, with the difference that they have ccw_device
1086  * arguments.
1087  *
1088  * A ccw driver also contains the information that is needed for
1089  * device matching.
1090  */
1091 static int
1092 ccw_device_probe (struct device *dev)
1093 {
1094         struct ccw_device *cdev = to_ccwdev(dev);
1095         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1096         int ret;
1097
1098         cdev->drv = cdrv; /* to let the driver call _set_online */
1099
1100         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1101
1102         if (ret) {
1103                 cdev->drv = NULL;
1104                 return ret;
1105         }
1106
1107         return 0;
1108 }
1109
1110 static int
1111 ccw_device_remove (struct device *dev)
1112 {
1113         struct ccw_device *cdev = to_ccwdev(dev);
1114         struct ccw_driver *cdrv = cdev->drv;
1115         int ret;
1116
1117         pr_debug("removing device %s\n", cdev->dev.bus_id);
1118         if (cdrv->remove)
1119                 cdrv->remove(cdev);
1120         if (cdev->online) {
1121                 cdev->online = 0;
1122                 spin_lock_irq(cdev->ccwlock);
1123                 ret = ccw_device_offline(cdev);
1124                 spin_unlock_irq(cdev->ccwlock);
1125                 if (ret == 0)
1126                         wait_event(cdev->private->wait_q,
1127                                    dev_fsm_final_state(cdev));
1128                 else
1129                         //FIXME: we can't fail!
1130                         pr_debug("ccw_device_offline returned %d, device %s\n",
1131                                  ret, cdev->dev.bus_id);
1132         }
1133         ccw_device_set_timeout(cdev, 0);
1134         cdev->drv = NULL;
1135         return 0;
1136 }
1137
1138 struct bus_type ccw_bus_type = {
1139         .name   = "ccw",
1140         .match  = ccw_bus_match,
1141         .uevent = ccw_uevent,
1142         .probe  = ccw_device_probe,
1143         .remove = ccw_device_remove,
1144 };
1145
1146 int
1147 ccw_driver_register (struct ccw_driver *cdriver)
1148 {
1149         struct device_driver *drv = &cdriver->driver;
1150
1151         drv->bus = &ccw_bus_type;
1152         drv->name = cdriver->name;
1153
1154         return driver_register(drv);
1155 }
1156
1157 void
1158 ccw_driver_unregister (struct ccw_driver *cdriver)
1159 {
1160         driver_unregister(&cdriver->driver);
1161 }
1162
1163 /* Helper func for qdio. */
1164 struct subchannel_id
1165 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1166 {
1167         struct subchannel *sch;
1168
1169         sch = to_subchannel(cdev->dev.parent);
1170         return sch->schid;
1171 }
1172
1173 MODULE_LICENSE("GPL");
1174 EXPORT_SYMBOL(ccw_device_set_online);
1175 EXPORT_SYMBOL(ccw_device_set_offline);
1176 EXPORT_SYMBOL(ccw_driver_register);
1177 EXPORT_SYMBOL(ccw_driver_unregister);
1178 EXPORT_SYMBOL(get_ccwdev_by_busid);
1179 EXPORT_SYMBOL(ccw_bus_type);
1180 EXPORT_SYMBOL(ccw_device_work);
1181 EXPORT_SYMBOL(ccw_device_notify_work);
1182 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);