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 IBM Corp. 2004, 2009
   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
  14 #define KMSG_COMPONENT "vmlogrdr"
  15 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  16
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/spinlock.h>
  24 #include <asm/atomic.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/cpcmd.h>
  27 #include <asm/debug.h>
  28 #include <asm/ebcdic.h>
  29 #include <net/iucv/iucv.h>
  30 #include <linux/kmod.h>
  31 #include <linux/cdev.h>
  32 #include <linux/device.h>
  33 #include <linux/smp_lock.h>
  34 #include <linux/string.h>
  35
  36 MODULE_AUTHOR
  37         ("(C) 2004 IBM Corporation by Xenia Tkatschow (xenia@us.ibm.com)\n"
  38          "                            Stefan Weinhuber (wein@de.ibm.com)");
  39 MODULE_DESCRIPTION ("Character device driver for reading z/VM "
  40                     "system service records.");
  41 MODULE_LICENSE("GPL");
  42
  43
  44 /*
  45  * The size of the buffer for iucv data transfer is one page,
  46  * but in addition to the data we read from iucv we also
  47  * place an integer and some characters into that buffer,
  48  * so the maximum size for record data is a little less then
  49  * one page.
  50  */
  51 #define NET_BUFFER_SIZE (PAGE_SIZE - sizeof(int) - sizeof(FENCE))
  52
  53 /*
  54  * The elements that are concurrently accessed by bottom halves are
  55  * connection_established, iucv_path_severed, local_interrupt_buffer
  56  * and receive_ready. The first three can be protected by
  57  * priv_lock.  receive_ready is atomic, so it can be incremented and
  58  * decremented without holding a lock.
  59  * The variable dev_in_use needs to be protected by the lock, since
  60  * it's a flag used by open to make sure that the device is opened only
  61  * by one user at the same time.
  62  */
  63 struct vmlogrdr_priv_t {
  64         char system_service[8];
  65         char internal_name[8];
  66         char recording_name[8];
  67         struct iucv_path *path;
  68         int connection_established;
  69         int iucv_path_severed;
  70         struct iucv_message local_interrupt_buffer;
  71         atomic_t receive_ready;
  72         int minor_num;
  73         char * buffer;
  74         char * current_position;
  75         int remaining;
  76         ulong residual_length;
  77         int buffer_free;
  78         int dev_in_use; /* 1: already opened, 0: not opened*/
  79         spinlock_t priv_lock;
  80         struct device  *device;
  81         struct device  *class_device;
  82         int autorecording;
  83         int autopurge;
  84 };
  85
  86
  87 /*
  88  * File operation structure for vmlogrdr devices
  89  */
  90 static int vmlogrdr_open(struct inode *, struct file *);
  91 static int vmlogrdr_release(struct inode *, struct file *);
  92 static ssize_t vmlogrdr_read (struct file *filp, char __user *data,
  93                               size_t count, loff_t * ppos);
  94
  95 static const struct file_operations vmlogrdr_fops = {
  96         .owner   = THIS_MODULE,
  97         .open    = vmlogrdr_open,
  98         .release = vmlogrdr_release,
  99         .read    = vmlogrdr_read,
 100         .llseek  = no_llseek,
 101 };
 102
 103
 104 static void vmlogrdr_iucv_path_complete(struct iucv_path *, u8 ipuser[16]);
 105 static void vmlogrdr_iucv_path_severed(struct iucv_path *, u8 ipuser[16]);
 106 static void vmlogrdr_iucv_message_pending(struct iucv_path *,
 107                                           struct iucv_message *);
 108
 109
 110 static struct iucv_handler vmlogrdr_iucv_handler = {
 111         .path_complete   = vmlogrdr_iucv_path_complete,
 112         .path_severed    = vmlogrdr_iucv_path_severed,
 113         .message_pending = vmlogrdr_iucv_message_pending,
 114 };
 115
 116
 117 static DECLARE_WAIT_QUEUE_HEAD(conn_wait_queue);
 118 static DECLARE_WAIT_QUEUE_HEAD(read_wait_queue);
 119
 120 /*
 121  * pointer to system service private structure
 122  * minor number 0 --> logrec
 123  * minor number 1 --> account
 124  * minor number 2 --> symptom
 125  */
 126
 127 static struct vmlogrdr_priv_t sys_ser[] = {
 128         { .system_service = "*LOGREC ",
 129           .internal_name  = "logrec",
 130           .recording_name = "EREP",
 131           .minor_num      = 0,
 132           .buffer_free    = 1,
 133           .priv_lock      = __SPIN_LOCK_UNLOCKED(sys_ser[0].priv_lock),
 134           .autorecording  = 1,
 135           .autopurge      = 1,
 136         },
 137         { .system_service = "*ACCOUNT",
 138           .internal_name  = "account",
 139           .recording_name = "ACCOUNT",
 140           .minor_num      = 1,
 141           .buffer_free    = 1,
 142           .priv_lock      = __SPIN_LOCK_UNLOCKED(sys_ser[1].priv_lock),
 143           .autorecording  = 1,
 144           .autopurge      = 1,
 145         },
 146         { .system_service = "*SYMPTOM",
 147           .internal_name  = "symptom",
 148           .recording_name = "SYMPTOM",
 149           .minor_num      = 2,
 150           .buffer_free    = 1,
 151           .priv_lock      = __SPIN_LOCK_UNLOCKED(sys_ser[2].priv_lock),
 152           .autorecording  = 1,
 153           .autopurge      = 1,
 154         }
 155 };
 156
 157 #define MAXMINOR  (sizeof(sys_ser)/sizeof(struct vmlogrdr_priv_t))
 158
 159 static char FENCE[] = {"EOR"};
 160 static int vmlogrdr_major = 0;
 161 static struct cdev  *vmlogrdr_cdev = NULL;
 162 static int recording_class_AB;
 163
 164
 165 static void vmlogrdr_iucv_path_complete(struct iucv_path *path, u8 ipuser[16])
 166 {
 167         struct vmlogrdr_priv_t * logptr = path->private;
 168
 169         spin_lock(&logptr->priv_lock);
 170         logptr->connection_established = 1;
 171         spin_unlock(&logptr->priv_lock);
 172         wake_up(&conn_wait_queue);
 173 }
 174
 175
 176 static void vmlogrdr_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
 177 {
 178         struct vmlogrdr_priv_t * logptr = path->private;
 179         u8 reason = (u8) ipuser[8];
 180
 181         pr_err("vmlogrdr: connection severed with reason %i\n", reason);
 182
 183         iucv_path_sever(path, NULL);
 184         kfree(path);
 185         logptr->path = NULL;
 186
 187         spin_lock(&logptr->priv_lock);
 188         logptr->connection_established = 0;
 189         logptr->iucv_path_severed = 1;
 190         spin_unlock(&logptr->priv_lock);
 191
 192         wake_up(&conn_wait_queue);
 193         /* just in case we're sleeping waiting for a record */
 194         wake_up_interruptible(&read_wait_queue);
 195 }
 196
 197
 198 static void vmlogrdr_iucv_message_pending(struct iucv_path *path,
 199                                           struct iucv_message *msg)
 200 {
 201         struct vmlogrdr_priv_t * logptr = path->private;
 202
 203         /*
 204          * This function is the bottom half so it should be quick.
 205          * Copy the external interrupt data into our local eib and increment
 206          * the usage count
 207          */
 208         spin_lock(&logptr->priv_lock);
 209         memcpy(&logptr->local_interrupt_buffer, msg, sizeof(*msg));
 210         atomic_inc(&logptr->receive_ready);
 211         spin_unlock(&logptr->priv_lock);
 212         wake_up_interruptible(&read_wait_queue);
 213 }
 214
 215
 216 static int vmlogrdr_get_recording_class_AB(void)
 217 {
 218         static const char cp_command[] = "QUERY COMMAND RECORDING ";
 219         char cp_response[80];
 220         char *tail;
 221         int len,i;
 222
 223         cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 224         len = strnlen(cp_response,sizeof(cp_response));
 225         // now the parsing
 226         tail=strnchr(cp_response,len,'=');
 227         if (!tail)
 228                 return 0;
 229         tail++;
 230         if (!strncmp("ANY",tail,3))
 231                 return 1;
 232         if (!strncmp("NONE",tail,4))
 233                 return 0;
 234         /*
 235          * expect comma separated list of classes here, if one of them
 236          * is A or B return 1 otherwise 0
 237          */
 238         for (i=tail-cp_response; i<len; i++)
 239                 if ( cp_response[i]=='A' || cp_response[i]=='B' )
 240                         return 1;
 241         return 0;
 242 }
 243
 244
 245 static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr,
 246                               int action, int purge)
 247 {
 248
 249         char cp_command[80];
 250         char cp_response[160];
 251         char *onoff, *qid_string;
 252
 253         memset(cp_command, 0x00, sizeof(cp_command));
 254         memset(cp_response, 0x00, sizeof(cp_response));
 255
 256         onoff = ((action == 1) ? "ON" : "OFF");
 257         qid_string = ((recording_class_AB == 1) ? " QID * " : "");
 258
 259         /*
 260          * The recording commands needs to be called with option QID
 261          * for guests that have previlege classes A or B.
 262          * Purging has to be done as separate step, because recording
 263          * can't be switched on as long as records are on the queue.
 264          * Doing both at the same time doesn't work.
 265          */
 266
 267         if (purge) {
 268                 snprintf(cp_command, sizeof(cp_command),
 269                          "RECORDING %s PURGE %s",
 270                          logptr->recording_name,
 271                          qid_string);
 272
 273                 cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 274         }
 275
 276         memset(cp_command, 0x00, sizeof(cp_command));
 277         memset(cp_response, 0x00, sizeof(cp_response));
 278         snprintf(cp_command, sizeof(cp_command), "RECORDING %s %s %s",
 279                 logptr->recording_name,
 280                 onoff,
 281                 qid_string);
 282
 283         cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 284         /* The recording command will usually answer with 'Command complete'
 285          * on success, but when the specific service was never connected
 286          * before then there might be an additional informational message
 287          * 'HCPCRC8072I Recording entry not found' before the
 288          * 'Command complete'. So I use strstr rather then the strncmp.
 289          */
 290         if (strstr(cp_response,"Command complete"))
 291                 return 0;
 292         else
 293                 return -EIO;
 294
 295 }
 296
 297
 298 static int vmlogrdr_open (struct inode *inode, struct file *filp)
 299 {
 300         int dev_num = 0;
 301         struct vmlogrdr_priv_t * logptr = NULL;
 302         int connect_rc = 0;
 303         int ret;
 304
 305         dev_num = iminor(inode);
 306         if (dev_num > MAXMINOR)
 307                 return -ENODEV;
 308         logptr = &sys_ser[dev_num];
 309
 310         /*
 311          * only allow for blocking reads to be open
 312          */
 313         if (filp->f_flags & O_NONBLOCK)
 314                 return -ENOSYS;
 315
 316         /* Besure this device hasn't already been opened */
 317         spin_lock_bh(&logptr->priv_lock);
 318         if (logptr->dev_in_use) {
 319                 spin_unlock_bh(&logptr->priv_lock);
 320                 return -EBUSY;
 321         }
 322         logptr->dev_in_use = 1;
 323         logptr->connection_established = 0;
 324         logptr->iucv_path_severed = 0;
 325         atomic_set(&logptr->receive_ready, 0);
 326         logptr->buffer_free = 1;
 327         spin_unlock_bh(&logptr->priv_lock);
 328
 329         /* set the file options */
 330         filp->private_data = logptr;
 331         filp->f_op = &vmlogrdr_fops;
 332
 333         /* start recording for this service*/
 334         if (logptr->autorecording) {
 335                 ret = vmlogrdr_recording(logptr,1,logptr->autopurge);
 336                 if (ret)
 337                         pr_warning("vmlogrdr: failed to start "
 338                                    "recording automatically\n");
 339         }
 340
 341         /* create connection to the system service */
 342         logptr->path = iucv_path_alloc(10, 0, GFP_KERNEL);
 343         if (!logptr->path)
 344                 goto out_dev;
 345         connect_rc = iucv_path_connect(logptr->path, &vmlogrdr_iucv_handler,
 346                                        logptr->system_service, NULL, NULL,
 347                                        logptr);
 348         if (connect_rc) {
 349                 pr_err("vmlogrdr: iucv connection to %s "
 350                        "failed with rc %i \n",
 351                        logptr->system_service, connect_rc);
 352                 goto out_path;
 353         }
 354
 355         /* We've issued the connect and now we must wait for a
 356          * ConnectionComplete or ConnectinSevered Interrupt
 357          * before we can continue to process.
 358          */
 359         wait_event(conn_wait_queue, (logptr->connection_established)
 360                    || (logptr->iucv_path_severed));
 361         if (logptr->iucv_path_severed)
 362                 goto out_record;
 363         nonseekable_open(inode, filp);
 364         return 0;
 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         return -EIO;
 375 }
 376
 377
 378 static int vmlogrdr_release (struct inode *inode, struct file *filp)
 379 {
 380         int ret;
 381
 382         struct vmlogrdr_priv_t * logptr = filp->private_data;
 383
 384         iucv_path_sever(logptr->path, NULL);
 385         kfree(logptr->path);
 386         logptr->path = NULL;
 387         if (logptr->autorecording) {
 388                 ret = vmlogrdr_recording(logptr,0,logptr->autopurge);
 389                 if (ret)
 390                         pr_warning("vmlogrdr: failed to stop "
 391                                    "recording automatically\n");
 392         }
 393         logptr->dev_in_use = 0;
 394
 395         return 0;
 396 }
 397
 398
 399 static int vmlogrdr_receive_data(struct vmlogrdr_priv_t *priv)
 400 {
 401         int rc, *temp;
 402         /* we need to keep track of two data sizes here:
 403          * The number of bytes we need to receive from iucv and
 404          * the total number of bytes we actually write into the buffer.
 405          */
 406         int user_data_count, iucv_data_count;
 407         char * buffer;
 408
 409         if (atomic_read(&priv->receive_ready)) {
 410                 spin_lock_bh(&priv->priv_lock);
 411                 if (priv->residual_length){
 412                         /* receive second half of a record */
 413                         iucv_data_count = priv->residual_length;
 414                         user_data_count = 0;
 415                         buffer = priv->buffer;
 416                 } else {
 417                         /* receive a new record:
 418                          * We need to return the total length of the record
 419                          * + size of FENCE in the first 4 bytes of the buffer.
 420                          */
 421                         iucv_data_count = priv->local_interrupt_buffer.length;
 422                         user_data_count = sizeof(int);
 423                         temp = (int*)priv->buffer;
 424                         *temp= iucv_data_count + sizeof(FENCE);
 425                         buffer = priv->buffer + sizeof(int);
 426                 }
 427                 /*
 428                  * If the record is bigger than our buffer, we receive only
 429                  * a part of it. We can get the rest later.
 430                  */
 431                 if (iucv_data_count > NET_BUFFER_SIZE)
 432                         iucv_data_count = NET_BUFFER_SIZE;
 433                 rc = iucv_message_receive(priv->path,
 434                                           &priv->local_interrupt_buffer,
 435                                           0, buffer, iucv_data_count,
 436                                           &priv->residual_length);
 437                 spin_unlock_bh(&priv->priv_lock);
 438                 /* An rc of 5 indicates that the record was bigger than
 439                  * the buffer, which is OK for us. A 9 indicates that the
 440                  * record was purged befor we could receive it.
 441                  */
 442                 if (rc == 5)
 443                         rc = 0;
 444                 if (rc == 9)
 445                         atomic_set(&priv->receive_ready, 0);
 446         } else {
 447                 rc = 1;
 448         }
 449         if (!rc) {
 450                 priv->buffer_free = 0;
 451                 user_data_count += iucv_data_count;
 452                 priv->current_position = priv->buffer;
 453                 if (priv->residual_length == 0){
 454                         /* the whole record has been captured,
 455                          * now add the fence */
 456                         atomic_dec(&priv->receive_ready);
 457                         buffer = priv->buffer + user_data_count;
 458                         memcpy(buffer, FENCE, sizeof(FENCE));
 459                         user_data_count += sizeof(FENCE);
 460                 }
 461                 priv->remaining = user_data_count;
 462         }
 463
 464         return rc;
 465 }
 466
 467
 468 static ssize_t vmlogrdr_read(struct file *filp, char __user *data,
 469                              size_t count, loff_t * ppos)
 470 {
 471         int rc;
 472         struct vmlogrdr_priv_t * priv = filp->private_data;
 473
 474         while (priv->buffer_free) {
 475                 rc = vmlogrdr_receive_data(priv);
 476                 if (rc) {
 477                         rc = wait_event_interruptible(read_wait_queue,
 478                                         atomic_read(&priv->receive_ready));
 479                         if (rc)
 480                                 return rc;
 481                 }
 482         }
 483         /* copy only up to end of record */
 484         if (count > priv->remaining)
 485                 count = priv->remaining;
 486
 487         if (copy_to_user(data, priv->current_position, count))
 488                 return -EFAULT;
 489
 490         *ppos += count;
 491         priv->current_position += count;
 492         priv->remaining -= count;
 493
 494         /* if all data has been transferred, set buffer free */
 495         if (priv->remaining == 0)
 496                 priv->buffer_free = 1;
 497
 498         return count;
 499 }
 500
 501 static ssize_t vmlogrdr_autopurge_store(struct device * dev,
 502                                         struct device_attribute *attr,
 503                                         const char * buf, size_t count)
 504 {
 505         struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
 506         ssize_t ret = count;
 507
 508         switch (buf[0]) {
 509         case '0':
 510                 priv->autopurge=0;
 511                 break;
 512         case '1':
 513                 priv->autopurge=1;
 514                 break;
 515         default:
 516                 ret = -EINVAL;
 517         }
 518         return ret;
 519 }
 520
 521
 522 static ssize_t vmlogrdr_autopurge_show(struct device *dev,
 523                                        struct device_attribute *attr,
 524                                        char *buf)
 525 {
 526         struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
 527         return sprintf(buf, "%u\n", priv->autopurge);
 528 }
 529
 530
 531 static DEVICE_ATTR(autopurge, 0644, vmlogrdr_autopurge_show,
 532                    vmlogrdr_autopurge_store);
 533
 534
 535 static ssize_t vmlogrdr_purge_store(struct device * dev,
 536                                     struct device_attribute *attr,
 537                                     const char * buf, size_t count)
 538 {
 539
 540         char cp_command[80];
 541         char cp_response[80];
 542         struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
 543
 544         if (buf[0] != '1')
 545                 return -EINVAL;
 546
 547         memset(cp_command, 0x00, sizeof(cp_command));
 548         memset(cp_response, 0x00, sizeof(cp_response));
 549
 550         /*
 551          * The recording command needs to be called with option QID
 552          * for guests that have previlege classes A or B.
 553          * Other guests will not recognize the command and we have to
 554          * issue the same command without the QID parameter.
 555          */
 556
 557         if (recording_class_AB)
 558                 snprintf(cp_command, sizeof(cp_command),
 559                          "RECORDING %s PURGE QID * ",
 560                          priv->recording_name);
 561         else
 562                 snprintf(cp_command, sizeof(cp_command),
 563                          "RECORDING %s PURGE ",
 564                          priv->recording_name);
 565
 566         cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
 567
 568         return count;
 569 }
 570
 571
 572 static DEVICE_ATTR(purge, 0200, NULL, vmlogrdr_purge_store);
 573
 574
 575 static ssize_t vmlogrdr_autorecording_store(struct device *dev,
 576                                             struct device_attribute *attr,
 577                                             const char *buf, size_t count)
 578 {
 579         struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
 580         ssize_t ret = count;
 581
 582         switch (buf[0]) {
 583         case '0':
 584                 priv->autorecording=0;
 585                 break;
 586         case '1':
 587                 priv->autorecording=1;
 588                 break;
 589         default:
 590                 ret = -EINVAL;
 591         }
 592         return ret;
 593 }
 594
 595
 596 static ssize_t vmlogrdr_autorecording_show(struct device *dev,
 597                                            struct device_attribute *attr,
 598                                            char *buf)
 599 {
 600         struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
 601         return sprintf(buf, "%u\n", priv->autorecording);
 602 }
 603
 604
 605 static DEVICE_ATTR(autorecording, 0644, vmlogrdr_autorecording_show,
 606                    vmlogrdr_autorecording_store);
 607
 608
 609 static ssize_t vmlogrdr_recording_store(struct device * dev,
 610                                         struct device_attribute *attr,
 611                                         const char * buf, size_t count)
 612 {
 613         struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
 614         ssize_t ret;
 615
 616         switch (buf[0]) {
 617         case '0':
 618                 ret = vmlogrdr_recording(priv,0,0);
 619                 break;
 620         case '1':
 621                 ret = vmlogrdr_recording(priv,1,0);
 622                 break;
 623         default:
 624                 ret = -EINVAL;
 625         }
 626         if (ret)
 627                 return ret;
 628         else
 629                 return count;
 630
 631 }
 632
 633
 634 static DEVICE_ATTR(recording, 0200, NULL, vmlogrdr_recording_store);
 635
 636
 637 static ssize_t vmlogrdr_recording_status_show(struct device_driver *driver,
 638                                               char *buf)
 639 {
 640
 641         static const char cp_command[] = "QUERY RECORDING ";
 642         int len;
 643
 644         cpcmd(cp_command, buf, 4096, NULL);
 645         len = strlen(buf);
 646         return len;
 647 }
 648
 649
 650 static DRIVER_ATTR(recording_status, 0444, vmlogrdr_recording_status_show,
 651                    NULL);
 652
 653 static struct attribute *vmlogrdr_attrs[] = {
 654         &dev_attr_autopurge.attr,
 655         &dev_attr_purge.attr,
 656         &dev_attr_autorecording.attr,
 657         &dev_attr_recording.attr,
 658         NULL,
 659 };
 660
 661 static int vmlogrdr_pm_prepare(struct device *dev)
 662 {
 663         int rc;
 664         struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
 665
 666         rc = 0;
 667         if (priv) {
 668                 spin_lock_bh(&priv->priv_lock);
 669                 if (priv->dev_in_use)
 670                         rc = -EBUSY;
 671                 spin_unlock_bh(&priv->priv_lock);
 672         }
 673         if (rc)
 674                 pr_err("vmlogrdr: device %s is busy. Refuse to suspend.\n",
 675                        dev_name(dev));
 676         return rc;
 677 }
 678
 679
 680 static const struct dev_pm_ops vmlogrdr_pm_ops = {
 681         .prepare = vmlogrdr_pm_prepare,
 682 };
 683
 684 static struct attribute_group vmlogrdr_attr_group = {
 685         .attrs = vmlogrdr_attrs,
 686 };
 687
 688 static struct class *vmlogrdr_class;
 689 static struct device_driver vmlogrdr_driver = {
 690         .name = "vmlogrdr",
 691         .bus  = &iucv_bus,
 692         .pm = &vmlogrdr_pm_ops,
 693 };
 694
 695
 696 static int vmlogrdr_register_driver(void)
 697 {
 698         int ret;
 699
 700         /* Register with iucv driver */
 701         ret = iucv_register(&vmlogrdr_iucv_handler, 1);
 702         if (ret)
 703                 goto out;
 704
 705         ret = driver_register(&vmlogrdr_driver);
 706         if (ret)
 707                 goto out_iucv;
 708
 709         ret = driver_create_file(&vmlogrdr_driver,
 710                                  &driver_attr_recording_status);
 711         if (ret)
 712                 goto out_driver;
 713
 714         vmlogrdr_class = class_create(THIS_MODULE, "vmlogrdr");
 715         if (IS_ERR(vmlogrdr_class)) {
 716                 ret = PTR_ERR(vmlogrdr_class);
 717                 vmlogrdr_class = NULL;
 718                 goto out_attr;
 719         }
 720         return 0;
 721
 722 out_attr:
 723         driver_remove_file(&vmlogrdr_driver, &driver_attr_recording_status);
 724 out_driver:
 725         driver_unregister(&vmlogrdr_driver);
 726 out_iucv:
 727         iucv_unregister(&vmlogrdr_iucv_handler, 1);
 728 out:
 729         return ret;
 730 }
 731
 732
 733 static void vmlogrdr_unregister_driver(void)
 734 {
 735         class_destroy(vmlogrdr_class);
 736         vmlogrdr_class = NULL;
 737         driver_remove_file(&vmlogrdr_driver, &driver_attr_recording_status);
 738         driver_unregister(&vmlogrdr_driver);
 739         iucv_unregister(&vmlogrdr_iucv_handler, 1);
 740 }
 741
 742
 743 static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv)
 744 {
 745         struct device *dev;
 746         int ret;
 747
 748         dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 749         if (dev) {
 750                 dev_set_name(dev, priv->internal_name);
 751                 dev->bus = &iucv_bus;
 752                 dev->parent = iucv_root;
 753                 dev->driver = &vmlogrdr_driver;
 754                 dev_set_drvdata(dev, priv);
 755                 /*
 756                  * The release function could be called after the
 757                  * module has been unloaded. It's _only_ task is to
 758                  * free the struct. Therefore, we specify kfree()
 759                  * directly here. (Probably a little bit obfuscating
 760                  * but legitime ...).
 761                  */
 762                 dev->release = (void (*)(struct device *))kfree;
 763         } else
 764                 return -ENOMEM;
 765         ret = device_register(dev);
 766         if (ret) {
 767                 put_device(dev);
 768                 return ret;
 769         }
 770
 771         ret = sysfs_create_group(&dev->kobj, &vmlogrdr_attr_group);
 772         if (ret) {
 773                 device_unregister(dev);
 774                 return ret;
 775         }
 776         priv->class_device = device_create(vmlogrdr_class, dev,
 777                                            MKDEV(vmlogrdr_major,
 778                                                  priv->minor_num),
 779                                            priv, "%s", dev_name(dev));
 780         if (IS_ERR(priv->class_device)) {
 781                 ret = PTR_ERR(priv->class_device);
 782                 priv->class_device=NULL;
 783                 sysfs_remove_group(&dev->kobj, &vmlogrdr_attr_group);
 784                 device_unregister(dev);
 785                 return ret;
 786         }
 787         priv->device = dev;
 788         return 0;
 789 }
 790
 791
 792 static int vmlogrdr_unregister_device(struct vmlogrdr_priv_t *priv)
 793 {
 794         device_destroy(vmlogrdr_class, MKDEV(vmlogrdr_major, priv->minor_num));
 795         if (priv->device != NULL) {
 796                 sysfs_remove_group(&priv->device->kobj, &vmlogrdr_attr_group);
 797                 device_unregister(priv->device);
 798                 priv->device=NULL;
 799         }
 800         return 0;
 801 }
 802
 803
 804 static int vmlogrdr_register_cdev(dev_t dev)
 805 {
 806         int rc = 0;
 807         vmlogrdr_cdev = cdev_alloc();
 808         if (!vmlogrdr_cdev) {
 809                 return -ENOMEM;
 810         }
 811         vmlogrdr_cdev->owner = THIS_MODULE;
 812         vmlogrdr_cdev->ops = &vmlogrdr_fops;
 813         vmlogrdr_cdev->dev = dev;
 814         rc = cdev_add(vmlogrdr_cdev, vmlogrdr_cdev->dev, MAXMINOR);
 815         if (!rc)
 816                 return 0;
 817
 818         // cleanup: cdev is not fully registered, no cdev_del here!
 819         kobject_put(&vmlogrdr_cdev->kobj);
 820         vmlogrdr_cdev=NULL;
 821         return rc;
 822 }
 823
 824
 825 static void vmlogrdr_cleanup(void)
 826 {
 827         int i;
 828
 829         if (vmlogrdr_cdev) {
 830                 cdev_del(vmlogrdr_cdev);
 831                 vmlogrdr_cdev=NULL;
 832         }
 833         for (i=0; i < MAXMINOR; ++i ) {
 834                 vmlogrdr_unregister_device(&sys_ser[i]);
 835                 free_page((unsigned long)sys_ser[i].buffer);
 836         }
 837         vmlogrdr_unregister_driver();
 838         if (vmlogrdr_major) {
 839                 unregister_chrdev_region(MKDEV(vmlogrdr_major, 0), MAXMINOR);
 840                 vmlogrdr_major=0;
 841         }
 842 }
 843
 844
 845 static int __init vmlogrdr_init(void)
 846 {
 847         int rc;
 848         int i;
 849         dev_t dev;
 850
 851         if (! MACHINE_IS_VM) {
 852                 pr_err("not running under VM, driver not loaded.\n");
 853                 return -ENODEV;
 854         }
 855
 856         recording_class_AB = vmlogrdr_get_recording_class_AB();
 857
 858         rc = alloc_chrdev_region(&dev, 0, MAXMINOR, "vmlogrdr");
 859         if (rc)
 860                 return rc;
 861         vmlogrdr_major = MAJOR(dev);
 862
 863         rc=vmlogrdr_register_driver();
 864         if (rc)
 865                 goto cleanup;
 866
 867         for (i=0; i < MAXMINOR; ++i ) {
 868                 sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL);
 869                 if (!sys_ser[i].buffer) {
 870                         rc = -ENOMEM;
 871                         break;
 872                 }
 873                 sys_ser[i].current_position = sys_ser[i].buffer;
 874                 rc=vmlogrdr_register_device(&sys_ser[i]);
 875                 if (rc)
 876                         break;
 877         }
 878         if (rc)
 879                 goto cleanup;
 880
 881         rc = vmlogrdr_register_cdev(dev);
 882         if (rc)
 883                 goto cleanup;
 884         return 0;
 885
 886 cleanup:
 887         vmlogrdr_cleanup();
 888         return rc;
 889 }
 890
 891
 892 static void __exit vmlogrdr_exit(void)
 893 {
 894         vmlogrdr_cleanup();
 895         return;
 896 }
 897
 898
 899 module_init(vmlogrdr_init);
 900 module_exit(vmlogrdr_exit);