git.oblomov.eu Git - linux-2.6/blob - drivers/s390/char/vmlogrdr.c

   1 /*
   2  * drivers/s390/char/vmlogrdr.c
   3  *      character device driver for reading z/VM system service records
   4  *
   5  *
   6  *      Copyright 2004 IBM Corporation
   7  *      character device driver for reading z/VM system service records,
   8  *      Version 1.0
   9  *      Author(s): Xenia Tkatschow <xenia@us.ibm.com>
  10  *                 Stefan Weinhuber <wein@de.ibm.com>
  11  *
  12  */
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/errno.h>
  16 #include <linux/types.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/spinlock.h>
  19 #include <asm/atomic.h>
  20 #include <asm/uaccess.h>
  21 #include <asm/cpcmd.h>
  22 #include <asm/debug.h>
  23 #include <asm/ebcdic.h>
  24 #include <net/iucv/iucv.h>
  25 #include <linux/kmod.h>
  26 #include <linux/cdev.h>
  27 #include <linux/device.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/string.h>
  30
  31
  32
  33 MODULE_AUTHOR
  34         ("(C) 2004 IBM Corporation by Xenia Tkatschow (xenia@us.ibm.com)\n"
  35          "                            Stefan Weinhuber (wein@de.ibm.com)");
  36 MODULE_DESCRIPTION ("Character device driver for reading z/VM "
  37                     "system service records.");
  38 MODULE_LICENSE("GPL");
  39
  40
  41 /*
  42  * The size of the buffer for iucv data transfer is one page,
  43  * but in addition to the data we read from iucv we also
  44  * place an integer and some characters into that buffer,
  45  * so the maximum size for record data is a little less then
  46  * one page.
  47  */
  48 #define NET_BUFFER_SIZE (PAGE_SIZE - sizeof(int) - sizeof(FENCE))
  49
  50 /*
  51  * The elements that are concurrently accessed by bottom halves are
  52  * connection_established, iucv_path_severed, local_interrupt_buffer
  53  * and receive_ready. The first three can be protected by
  54  * priv_lock.  receive_ready is atomic, so it can be incremented and
  55  * decremented without holding a lock.
  56  * The variable dev_in_use needs to be protected by the lock, since
  57  * it's a flag used by open to make sure that the device is opened only
  58  * by one user at the same time.
  59  */
  60 struct vmlogrdr_priv_t {
  61         char system_service[8];
  62         char internal_name[8];
  63         char recording_name[8];
  64         struct iucv_path *path;
  65         int connection_established;
  66         int iucv_path_severed;
  67         struct iucv_message local_interrupt_buffer;
  68         atomic_t receive_ready;
  69         int minor_num;
  70         char * buffer;
  71         char * current_position;
  72         int remaining;
  73         ulong residual_length;
  74         int buffer_free;
  75         int dev_in_use; /* 1: already opened, 0: not opened*/
  76         spinlock_t priv_lock;
  77         struct device  *device;
  78         struct device  *class_device;
  79         int autorecording;
  80         int autopurge;
  81 };
  82
  83
  84 /*
  85  * File operation structure for vmlogrdr devices
  86  */
  87 static int vmlogrdr_open(struct inode *, struct file *);
  88 static int vmlogrdr_release(struct inode *, struct file *);
  89 static ssize_t vmlogrdr_read (struct file *filp, char __user *data,
  90                               size_t count, loff_t * ppos);
  91
  92 static const struct file_operations vmlogrdr_fops = {
  93         .owner   = THIS_MODULE,
  94         .open    = vmlogrdr_open,
  95         .release = vmlogrdr_release,
  96         .read    = vmlogrdr_read,
  97 };
  98
  99
 100 static void vmlogrdr_iucv_path_complete(struct iucv_path *, u8 ipuser[16]);
 101 static void vmlogrdr_iucv_path_severed(struct iucv_path *, u8 ipuser[16]);
 102 static void vmlogrdr_iucv_message_pending(struct iucv_path *,
 103                                           struct iucv_message *);
 104
 105
 106 static struct iucv_handler vmlogrdr_iucv_handler = {
 107         .path_complete   = vmlogrdr_iucv_path_complete,
 108         .path_severed    = vmlogrdr_iucv_path_severed,
 109         .message_pending = vmlogrdr_iucv_message_pending,
 110 };
 111
 112
 113 static DECLARE_WAIT_QUEUE_HEAD(conn_wait_queue);
 114 static DECLARE_WAIT_QUEUE_HEAD(read_wait_queue);
 115
 116 /*
 117  * pointer to system service private structure
 118  * minor number 0 --> logrec
 119  * minor number 1 --> account
 120  * minor number 2 --> symptom
 121  */
 122
 123 static struct vmlogrdr_priv_t sys_ser[] = {
 124         { .system_service = "*LOGREC ",
 125           .internal_name  = "logrec",
 126           .recording_name = "EREP",
 127           .minor_num      = 0,
 128           .buffer_free    = 1,
 129           .priv_lock      = __SPIN_LOCK_UNLOCKED(sys_ser[0].priv_lock),
 130           .autorecording  = 1,
 131           .autopurge      = 1,
 132         },
 133         { .system_service = "*ACCOUNT",
 134           .internal_name  = "account",
 135           .recording_name = "ACCOUNT",
 136           .minor_num      = 1,
 137           .buffer_free    = 1,
 138           .priv_lock      = __SPIN_LOCK_UNLOCKED(sys_ser[1].priv_lock),
 139           .autorecording  = 1,
 140           .autopurge      = 1,
 141         },
 142         { .system_service = "*SYMPTOM",
 143           .internal_name  = "symptom",
 144           .recording_name = "SYMPTOM",
 145           .minor_num      = 2,
 146           .buffer_free    = 1,
 147           .priv_lock      = __SPIN_LOCK_UNLOCKED(sys_ser[2].priv_lock),
 148           .autorecording  = 1,
 149           .autopurge      = 1,
 150         }
 151 };
 152
 153 #define MAXMINOR  (sizeof(sys_ser)/sizeof(struct vmlogrdr_priv_t))
 154
 155 static char FENCE[] = {"EOR"};
 156 static int vmlogrdr_major = 0;
 157 static struct cdev  *vmlogrdr_cdev = NULL;
 158 static int recording_class_AB;
 159
 160
 161 static void vmlogrdr_iucv_path_complete(struct iucv_path *path, u8 ipuser[16])
 162 {
 163         struct vmlogrdr_priv_t * logptr = path->private;
 164
 165         spin_lock(&logptr->priv_lock);
 166         logptr->connection_established = 1;
 167         spin_unlock(&logptr->priv_lock);
 168         wake_up(&conn_wait_queue);
 169 }
 170
 171
 172 static void vmlogrdr_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
 173 {
 174         struct vmlogrdr_priv_t * logptr = path->private;
 175         u8 reason = (u8) ipuser[8];
 176
 177         printk (KERN_ERR "vmlogrdr: connection severed with"
 178                 " reason %i\n", reason);
 179
 180         iucv_path_sever(path, NULL);
 181         kfree(path);
 182         logptr->path = NULL;
 183
 184         spin_lock(&logptr->priv_lock);
 185         logptr->connection_established = 0;
 186         logptr->iucv_path_severed = 1;
 187         spin_unlock(&logptr->priv_lock);
 188
 189         wake_up(&conn_wait_queue);
 190         /* just in case we're sleeping waiting for a record */
 191         wake_up_interruptible(&read_wait_queue);
 192 }
 193
 194
 195 static void vmlogrdr_iucv_message_pending(struct iucv_path *path,
 196                                           struct iucv_message *msg)
 197 {
 198         struct vmlogrdr_priv_t * logptr = path->private;
 199
 200         /*
 201          * This function is the bottom half so it should be quick.
 202          * Copy the external interrupt data into our local eib and increment
 203          * the usage count
 204          */
 205         spin_lock(&logptr->priv_lock);
 206         memcpy(&logptr->local_interrupt_buffer, msg, sizeof(*msg));
 207         atomic_inc(&logptr->receive_ready);
 208         spin_unlock(&logptr->priv_lock);
 209         wake_up_interruptible(&read_wait_queue);
 210 }
 211
 212
 213 static int vmlogrdr_get_recording_class_AB(void)
 214 {
 215         char cp_command[]="QUERY COMMAND RECORDING ";
 216         char cp_response[80];
 217         char *tail;
 218         int len,i;
 219
 220         cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 221         len = strnlen(cp_response,sizeof(cp_response));
 222         // now the parsing
 223         tail=strnchr(cp_response,len,'=');
 224         if (!tail)
 225                 return 0;
 226         tail++;
 227         if (!strncmp("ANY",tail,3))
 228                 return 1;
 229         if (!strncmp("NONE",tail,4))
 230                 return 0;
 231         /*
 232          * expect comma separated list of classes here, if one of them
 233          * is A or B return 1 otherwise 0
 234          */
 235         for (i=tail-cp_response; i<len; i++)
 236                 if ( cp_response[i]=='A' || cp_response[i]=='B' )
 237                         return 1;
 238         return 0;
 239 }
 240
 241
 242 static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr,
 243                               int action, int purge)
 244 {
 245
 246         char cp_command[80];
 247         char cp_response[160];
 248         char *onoff, *qid_string;
 249
 250         memset(cp_command, 0x00, sizeof(cp_command));
 251         memset(cp_response, 0x00, sizeof(cp_response));
 252
 253         onoff = ((action == 1) ? "ON" : "OFF");
 254         qid_string = ((recording_class_AB == 1) ? " QID * " : "");
 255
 256         /*
 257          * The recording commands needs to be called with option QID
 258          * for guests that have previlege classes A or B.
 259          * Purging has to be done as separate step, because recording
 260          * can't be switched on as long as records are on the queue.
 261          * Doing both at the same time doesn't work.
 262          */
 263
 264         if (purge) {
 265                 snprintf(cp_command, sizeof(cp_command),
 266                          "RECORDING %s PURGE %s",
 267                          logptr->recording_name,
 268                          qid_string);
 269
 270                 cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 271         }
 272
 273         memset(cp_command, 0x00, sizeof(cp_command));
 274         memset(cp_response, 0x00, sizeof(cp_response));
 275         snprintf(cp_command, sizeof(cp_command), "RECORDING %s %s %s",
 276                 logptr->recording_name,
 277                 onoff,
 278                 qid_string);
 279
 280         cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 281         /* The recording command will usually answer with 'Command complete'
 282          * on success, but when the specific service was never connected
 283          * before then there might be an additional informational message
 284          * 'HCPCRC8072I Recording entry not found' before the
 285          * 'Command complete'. So I use strstr rather then the strncmp.
 286          */
 287         if (strstr(cp_response,"Command complete"))
 288                 return 0;
 289         else
 290                 return -EIO;
 291
 292 }
 293
 294
 295 static int vmlogrdr_open (struct inode *inode, struct file *filp)
 296 {
 297         int dev_num = 0;
 298         struct vmlogrdr_priv_t * logptr = NULL;
 299         int connect_rc = 0;
 300         int ret;
 301
 302         dev_num = iminor(inode);
 303         if (dev_num > MAXMINOR)
 304                 return -ENODEV;
 305         logptr = &sys_ser[dev_num];
 306
 307         /*
 308          * only allow for blocking reads to be open
 309          */
 310         if (filp->f_flags & O_NONBLOCK)
 311                 return -ENOSYS;
 312
 313         /* Besure this device hasn't already been opened */
 314         lock_kernel();
 315         spin_lock_bh(&logptr->priv_lock);
 316         if (logptr->dev_in_use) {
 317                 spin_unlock_bh(&logptr->priv_lock);
 318                 unlock_kernel();
 319                 return -EBUSY;
 320         }
 321         logptr->dev_in_use = 1;
 322         logptr->connection_established = 0;
 323         logptr->iucv_path_severed = 0;
 324         atomic_set(&logptr->receive_ready, 0);
 325         logptr->buffer_free = 1;
 326         spin_unlock_bh(&logptr->priv_lock);
 327
 328         /* set the file options */
 329         filp->private_data = logptr;
 330         filp->f_op = &vmlogrdr_fops;
 331
 332         /* start recording for this service*/
 333         if (logptr->autorecording) {
 334                 ret = vmlogrdr_recording(logptr,1,logptr->autopurge);
 335                 if (ret)
 336                         printk (KERN_WARNING "vmlogrdr: failed to start "
 337                                 "recording automatically\n");
 338         }
 339
 340         /* create connection to the system service */
 341         logptr->path = iucv_path_alloc(10, 0, GFP_KERNEL);
 342         if (!logptr->path)
 343                 goto out_dev;
 344         connect_rc = iucv_path_connect(logptr->path, &vmlogrdr_iucv_handler,
 345                                        logptr->system_service, NULL, NULL,
 346                                        logptr);
 347         if (connect_rc) {
 348                 printk (KERN_ERR "vmlogrdr: iucv connection to %s "
 349                         "failed with rc %i \n", logptr->system_service,
 350                         connect_rc);
 351                 goto out_path;
 352         }
 353
 354         /* We've issued the connect and now we must wait for a
 355          * ConnectionComplete or ConnectinSevered Interrupt
 356          * before we can continue to process.
 357          */
 358         wait_event(conn_wait_queue, (logptr->connection_established)
 359                    || (logptr->iucv_path_severed));
 360         if (logptr->iucv_path_severed)
 361                 goto out_record;
 362         ret = nonseekable_open(inode, filp);
 363         unlock_kernel();
 364         return ret;
 365
 366 out_record:
 367         if (logptr->autorecording)
 368                 vmlogrdr_recording(logptr,0,logptr->autopurge);
 369 out_path:
 370         kfree(logptr->path);    /* kfree(NULL) is ok. */
 371         logptr->path = NULL;
 372 out_dev:
 373         logptr->dev_in_use = 0;
 374         unlock_kernel();
 375         return -EIO;
 376 }
 377
 378
 379 static int vmlogrdr_release (struct inode *inode, struct file *filp)
 380 {
 381         int ret;
 382
 383         struct vmlogrdr_priv_t * logptr = filp->private_data;
 384
 385         iucv_path_sever(logptr->path, NULL);
 386         kfree(logptr->path);
 387         logptr->path = NULL;
 388         if (logptr->autorecording) {
 389                 ret = vmlogrdr_recording(logptr,0,logptr->autopurge);
 390                 if (ret)
 391                         printk (KERN_WARNING "vmlogrdr: failed to stop "
 392                                 "recording automatically\n");
 393         }
 394         logptr->dev_in_use = 0;
 395
 396         return 0;
 397 }
 398
 399
 400 static int vmlogrdr_receive_data(struct vmlogrdr_priv_t *priv)
 401 {
 402         int rc, *temp;
 403         /* we need to keep track of two data sizes here:
 404          * The number of bytes we need to receive from iucv and
 405          * the total number of bytes we actually write into the buffer.
 406          */
 407         int user_data_count, iucv_data_count;
 408         char * buffer;
 409
 410         if (atomic_read(&priv->receive_ready)) {
 411                 spin_lock_bh(&priv->priv_lock);
 412                 if (priv->residual_length){
 413                         /* receive second half of a record */
 414                         iucv_data_count = priv->residual_length;
 415                         user_data_count = 0;
 416                         buffer = priv->buffer;
 417                 } else {
 418                         /* receive a new record:
 419                          * We need to return the total length of the record
 420                          * + size of FENCE in the first 4 bytes of the buffer.
 421                          */
 422                         iucv_data_count = priv->local_interrupt_buffer.length;
 423                         user_data_count = sizeof(int);
 424                         temp = (int*)priv->buffer;
 425                         *temp= iucv_data_count + sizeof(FENCE);
 426                         buffer = priv->buffer + sizeof(int);
 427                 }
 428                 /*
 429                  * If the record is bigger then our buffer, we receive only
 430                  * a part of it. We can get the rest later.
 431                  */
 432                 if (iucv_data_count > NET_BUFFER_SIZE)
 433                         iucv_data_count = NET_BUFFER_SIZE;
 434                 rc = iucv_message_receive(priv->path,
 435                                           &priv->local_interrupt_buffer,
 436                                           0, buffer, iucv_data_count,
 437                                           &priv->residual_length);
 438                 spin_unlock_bh(&priv->priv_lock);
 439                 /* An rc of 5 indicates that the record was bigger then
 440                  * the buffer, which is OK for us. A 9 indicates that the
 441                  * record was purged befor we could receive it.
 442                  */
 443                 if (rc == 5)
 444                         rc = 0;
 445                 if (rc == 9)
 446                         atomic_set(&priv->receive_ready, 0);
 447         } else {
 448                 rc = 1;
 449         }
 450         if (!rc) {
 451                 priv->buffer_free = 0;
 452                 user_data_count += iucv_data_count;
 453                 priv->current_position = priv->buffer;
 454                 if (priv->residual_length == 0){
 455                         /* the whole record has been captured,
 456                          * now add the fence */
 457                         atomic_dec(&priv->receive_ready);
 458                         buffer = priv->buffer + user_data_count;
 459                         memcpy(buffer, FENCE, sizeof(FENCE));
 460                         user_data_count += sizeof(FENCE);
 461                 }
 462                 priv->remaining = user_data_count;
 463         }
 464
 465         return rc;
 466 }
 467
 468
 469 static ssize_t vmlogrdr_read(struct file *filp, char __user *data,
 470                              size_t count, loff_t * ppos)
 471 {
 472         int rc;
 473         struct vmlogrdr_priv_t * priv = filp->private_data;
 474
 475         while (priv->buffer_free) {
 476                 rc = vmlogrdr_receive_data(priv);
 477                 if (rc) {
 478                         rc = wait_event_interruptible(read_wait_queue,
 479                                         atomic_read(&priv->receive_ready));
 480                         if (rc)
 481                                 return rc;
 482                 }
 483         }
 484         /* copy only up to end of record */
 485         if (count > priv->remaining)
 486                 count = priv->remaining;
 487
 488         if (copy_to_user(data, priv->current_position, count))
 489                 return -EFAULT;
 490
 491         *ppos += count;
 492         priv->current_position += count;
 493         priv->remaining -= count;
 494
 495         /* if all data has been transferred, set buffer free */
 496         if (priv->remaining == 0)
 497                 priv->buffer_free = 1;
 498
 499         return count;
 500 }
 501
 502 static ssize_t vmlogrdr_autopurge_store(struct device * dev,
 503                                         struct device_attribute *attr,
 504                                         const char * buf, size_t count)
 505 {
 506         struct vmlogrdr_priv_t *priv = dev->driver_data;
 507         ssize_t ret = count;
 508
 509         switch (buf[0]) {
 510         case '0':
 511                 priv->autopurge=0;
 512                 break;
 513         case '1':
 514                 priv->autopurge=1;
 515                 break;
 516         default:
 517                 ret = -EINVAL;
 518         }
 519         return ret;
 520 }
 521
 522
 523 static ssize_t vmlogrdr_autopurge_show(struct device *dev,
 524                                        struct device_attribute *attr,
 525                                        char *buf)
 526 {
 527         struct vmlogrdr_priv_t *priv = dev->driver_data;
 528         return sprintf(buf, "%u\n", priv->autopurge);
 529 }
 530
 531
 532 static DEVICE_ATTR(autopurge, 0644, vmlogrdr_autopurge_show,
 533                    vmlogrdr_autopurge_store);
 534
 535
 536 static ssize_t vmlogrdr_purge_store(struct device * dev,
 537                                     struct device_attribute *attr,
 538                                     const char * buf, size_t count)
 539 {
 540
 541         char cp_command[80];
 542         char cp_response[80];
 543         struct vmlogrdr_priv_t *priv = dev->driver_data;
 544
 545         if (buf[0] != '1')
 546                 return -EINVAL;
 547
 548         memset(cp_command, 0x00, sizeof(cp_command));
 549         memset(cp_response, 0x00, sizeof(cp_response));
 550
 551         /*
 552          * The recording command needs to be called with option QID
 553          * for guests that have previlege classes A or B.
 554          * Other guests will not recognize the command and we have to
 555          * issue the same command without the QID parameter.
 556          */
 557
 558         if (recording_class_AB)
 559                 snprintf(cp_command, sizeof(cp_command),
 560                          "RECORDING %s PURGE QID * ",
 561                          priv->recording_name);
 562         else
 563                 snprintf(cp_command, sizeof(cp_command),
 564                          "RECORDING %s PURGE ",
 565                          priv->recording_name);
 566
 567         cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 568
 569         return count;
 570 }
 571
 572
 573 static DEVICE_ATTR(purge, 0200, NULL, vmlogrdr_purge_store);
 574
 575
 576 static ssize_t vmlogrdr_autorecording_store(struct device *dev,
 577                                             struct device_attribute *attr,
 578                                             const char *buf, size_t count)
 579 {
 580         struct vmlogrdr_priv_t *priv = dev->driver_data;
 581         ssize_t ret = count;
 582
 583         switch (buf[0]) {
 584         case '0':
 585                 priv->autorecording=0;
 586                 break;
 587         case '1':
 588                 priv->autorecording=1;
 589                 break;
 590         default:
 591                 ret = -EINVAL;
 592         }
 593         return ret;
 594 }
 595
 596
 597 static ssize_t vmlogrdr_autorecording_show(struct device *dev,
 598                                            struct device_attribute *attr,
 599                                            char *buf)
 600 {
 601         struct vmlogrdr_priv_t *priv = dev->driver_data;
 602         return sprintf(buf, "%u\n", priv->autorecording);
 603 }
 604
 605
 606 static DEVICE_ATTR(autorecording, 0644, vmlogrdr_autorecording_show,
 607                    vmlogrdr_autorecording_store);
 608
 609
 610 static ssize_t vmlogrdr_recording_store(struct device * dev,
 611                                         struct device_attribute *attr,
 612                                         const char * buf, size_t count)
 613 {
 614         struct vmlogrdr_priv_t *priv = dev->driver_data;
 615         ssize_t ret;
 616
 617         switch (buf[0]) {
 618         case '0':
 619                 ret = vmlogrdr_recording(priv,0,0);
 620                 break;
 621         case '1':
 622                 ret = vmlogrdr_recording(priv,1,0);
 623                 break;
 624         default:
 625                 ret = -EINVAL;
 626         }
 627         if (ret)
 628                 return ret;
 629         else
 630                 return count;
 631
 632 }
 633
 634
 635 static DEVICE_ATTR(recording, 0200, NULL, vmlogrdr_recording_store);
 636
 637
 638 static ssize_t vmlogrdr_recording_status_show(struct device_driver *driver,
 639                                               char *buf)
 640 {
 641
 642         char cp_command[] = "QUERY RECORDING ";
 643         int len;
 644
 645         cpcmd(cp_command, buf, 4096, NULL);
 646         len = strlen(buf);
 647         return len;
 648 }
 649
 650
 651 static DRIVER_ATTR(recording_status, 0444, vmlogrdr_recording_status_show,
 652                    NULL);
 653
 654 static struct attribute *vmlogrdr_attrs[] = {
 655         &dev_attr_autopurge.attr,
 656         &dev_attr_purge.attr,
 657         &dev_attr_autorecording.attr,
 658         &dev_attr_recording.attr,
 659         NULL,
 660 };
 661
 662 static struct attribute_group vmlogrdr_attr_group = {
 663         .attrs = vmlogrdr_attrs,
 664 };
 665
 666 static struct class *vmlogrdr_class;
 667 static struct device_driver vmlogrdr_driver = {
 668         .name = "vmlogrdr",
 669         .bus  = &iucv_bus,
 670 };
 671
 672
 673 static int vmlogrdr_register_driver(void)
 674 {
 675         int ret;
 676
 677         /* Register with iucv driver */
 678         ret = iucv_register(&vmlogrdr_iucv_handler, 1);
 679         if (ret)
 680                 goto out;
 681
 682         ret = driver_register(&vmlogrdr_driver);
 683         if (ret)
 684                 goto out_iucv;
 685
 686         ret = driver_create_file(&vmlogrdr_driver,
 687                                  &driver_attr_recording_status);
 688         if (ret)
 689                 goto out_driver;
 690
 691         vmlogrdr_class = class_create(THIS_MODULE, "vmlogrdr");
 692         if (IS_ERR(vmlogrdr_class)) {
 693                 ret = PTR_ERR(vmlogrdr_class);
 694                 vmlogrdr_class = NULL;
 695                 goto out_attr;
 696         }
 697         return 0;
 698
 699 out_attr:
 700         driver_remove_file(&vmlogrdr_driver, &driver_attr_recording_status);
 701 out_driver:
 702         driver_unregister(&vmlogrdr_driver);
 703 out_iucv:
 704         iucv_unregister(&vmlogrdr_iucv_handler, 1);
 705 out:
 706         return ret;
 707 }
 708
 709
 710 static void vmlogrdr_unregister_driver(void)
 711 {
 712         class_destroy(vmlogrdr_class);
 713         vmlogrdr_class = NULL;
 714         driver_remove_file(&vmlogrdr_driver, &driver_attr_recording_status);
 715         driver_unregister(&vmlogrdr_driver);
 716         iucv_unregister(&vmlogrdr_iucv_handler, 1);
 717 }
 718
 719
 720 static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv)
 721 {
 722         struct device *dev;
 723         int ret;
 724
 725         dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 726         if (dev) {
 727                 dev_set_name(dev, priv->internal_name);
 728                 dev->bus = &iucv_bus;
 729                 dev->parent = iucv_root;
 730                 dev->driver = &vmlogrdr_driver;
 731                 /*
 732                  * The release function could be called after the
 733                  * module has been unloaded. It's _only_ task is to
 734                  * free the struct. Therefore, we specify kfree()
 735                  * directly here. (Probably a little bit obfuscating
 736                  * but legitime ...).
 737                  */
 738                 dev->release = (void (*)(struct device *))kfree;
 739         } else
 740                 return -ENOMEM;
 741         ret = device_register(dev);
 742         if (ret)
 743                 return ret;
 744
 745         ret = sysfs_create_group(&dev->kobj, &vmlogrdr_attr_group);
 746         if (ret) {
 747                 device_unregister(dev);
 748                 return ret;
 749         }
 750         priv->class_device = device_create(vmlogrdr_class, dev,
 751                                            MKDEV(vmlogrdr_major,
 752                                                  priv->minor_num),
 753                                            priv, "%s", dev_name(dev));
 754         if (IS_ERR(priv->class_device)) {
 755                 ret = PTR_ERR(priv->class_device);
 756                 priv->class_device=NULL;
 757                 sysfs_remove_group(&dev->kobj, &vmlogrdr_attr_group);
 758                 device_unregister(dev);
 759                 return ret;
 760         }
 761         priv->device = dev;
 762         return 0;
 763 }
 764
 765
 766 static int vmlogrdr_unregister_device(struct vmlogrdr_priv_t *priv)
 767 {
 768         device_destroy(vmlogrdr_class, MKDEV(vmlogrdr_major, priv->minor_num));
 769         if (priv->device != NULL) {
 770                 sysfs_remove_group(&priv->device->kobj, &vmlogrdr_attr_group);
 771                 device_unregister(priv->device);
 772                 priv->device=NULL;
 773         }
 774         return 0;
 775 }
 776
 777
 778 static int vmlogrdr_register_cdev(dev_t dev)
 779 {
 780         int rc = 0;
 781         vmlogrdr_cdev = cdev_alloc();
 782         if (!vmlogrdr_cdev) {
 783                 return -ENOMEM;
 784         }
 785         vmlogrdr_cdev->owner = THIS_MODULE;
 786         vmlogrdr_cdev->ops = &vmlogrdr_fops;
 787         vmlogrdr_cdev->dev = dev;
 788         rc = cdev_add(vmlogrdr_cdev, vmlogrdr_cdev->dev, MAXMINOR);
 789         if (!rc)
 790                 return 0;
 791
 792         // cleanup: cdev is not fully registered, no cdev_del here!
 793         kobject_put(&vmlogrdr_cdev->kobj);
 794         vmlogrdr_cdev=NULL;
 795         return rc;
 796 }
 797
 798
 799 static void vmlogrdr_cleanup(void)
 800 {
 801         int i;
 802
 803         if (vmlogrdr_cdev) {
 804                 cdev_del(vmlogrdr_cdev);
 805                 vmlogrdr_cdev=NULL;
 806         }
 807         for (i=0; i < MAXMINOR; ++i ) {
 808                 vmlogrdr_unregister_device(&sys_ser[i]);
 809                 free_page((unsigned long)sys_ser[i].buffer);
 810         }
 811         vmlogrdr_unregister_driver();
 812         if (vmlogrdr_major) {
 813                 unregister_chrdev_region(MKDEV(vmlogrdr_major, 0), MAXMINOR);
 814                 vmlogrdr_major=0;
 815         }
 816 }
 817
 818
 819 static int __init vmlogrdr_init(void)
 820 {
 821         int rc;
 822         int i;
 823         dev_t dev;
 824
 825         if (! MACHINE_IS_VM) {
 826                 printk (KERN_ERR "vmlogrdr: not running under VM, "
 827                                 "driver not loaded.\n");
 828                 return -ENODEV;
 829         }
 830
 831         recording_class_AB = vmlogrdr_get_recording_class_AB();
 832
 833         rc = alloc_chrdev_region(&dev, 0, MAXMINOR, "vmlogrdr");
 834         if (rc)
 835                 return rc;
 836         vmlogrdr_major = MAJOR(dev);
 837
 838         rc=vmlogrdr_register_driver();
 839         if (rc)
 840                 goto cleanup;
 841
 842         for (i=0; i < MAXMINOR; ++i ) {
 843                 sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL);
 844                 if (!sys_ser[i].buffer) {
 845                         rc = -ENOMEM;
 846                         break;
 847                 }
 848                 sys_ser[i].current_position = sys_ser[i].buffer;
 849                 rc=vmlogrdr_register_device(&sys_ser[i]);
 850                 if (rc)
 851                         break;
 852         }
 853         if (rc)
 854                 goto cleanup;
 855
 856         rc = vmlogrdr_register_cdev(dev);
 857         if (rc)
 858                 goto cleanup;
 859         return 0;
 860
 861 cleanup:
 862         vmlogrdr_cleanup();
 863         return rc;
 864 }
 865
 866
 867 static void __exit vmlogrdr_exit(void)
 868 {
 869         vmlogrdr_cleanup();
 870         return;
 871 }
 872
 873
 874 module_init(vmlogrdr_init);
 875 module_exit(vmlogrdr_exit);