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