release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/kernel/nvram_64.c

   1 /*
   2  *  c 2001 PPC 64 Team, IBM Corp
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  *
   9  * /dev/nvram driver for PPC64
  10  *
  11  * This perhaps should live in drivers/char
  12  *
  13  * TODO: Split the /dev/nvram part (that one can use
  14  *       drivers/char/generic_nvram.c) from the arch & partition
  15  *       parsing code.
  16  */
  17
  18 #include <linux/module.h>
  19
  20 #include <linux/types.h>
  21 #include <linux/errno.h>
  22 #include <linux/fs.h>
  23 #include <linux/miscdevice.h>
  24 #include <linux/fcntl.h>
  25 #include <linux/nvram.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/nvram.h>
  31 #include <asm/rtas.h>
  32 #include <asm/prom.h>
  33 #include <asm/machdep.h>
  34
  35 #undef DEBUG_NVRAM
  36
  37 static struct nvram_partition * nvram_part;
  38 static long nvram_error_log_index = -1;
  39 static long nvram_error_log_size = 0;
  40
  41 struct err_log_info {
  42         int error_type;
  43         unsigned int seq_num;
  44 };
  45
  46 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
  47 {
  48         int size;
  49
  50         if (ppc_md.nvram_size == NULL)
  51                 return -ENODEV;
  52         size = ppc_md.nvram_size();
  53
  54         switch (origin) {
  55         case 1:
  56                 offset += file->f_pos;
  57                 break;
  58         case 2:
  59                 offset += size;
  60                 break;
  61         }
  62         if (offset < 0)
  63                 return -EINVAL;
  64         file->f_pos = offset;
  65         return file->f_pos;
  66 }
  67
  68
  69 static ssize_t dev_nvram_read(struct file *file, char __user *buf,
  70                           size_t count, loff_t *ppos)
  71 {
  72         ssize_t ret;
  73         char *tmp = NULL;
  74         ssize_t size;
  75
  76         ret = -ENODEV;
  77         if (!ppc_md.nvram_size)
  78                 goto out;
  79
  80         ret = 0;
  81         size = ppc_md.nvram_size();
  82         if (*ppos >= size || size < 0)
  83                 goto out;
  84
  85         count = min_t(size_t, count, size - *ppos);
  86         count = min(count, PAGE_SIZE);
  87
  88         ret = -ENOMEM;
  89         tmp = kmalloc(count, GFP_KERNEL);
  90         if (!tmp)
  91                 goto out;
  92
  93         ret = ppc_md.nvram_read(tmp, count, ppos);
  94         if (ret <= 0)
  95                 goto out;
  96
  97         if (copy_to_user(buf, tmp, ret))
  98                 ret = -EFAULT;
  99
 100 out:
 101         kfree(tmp);
 102         return ret;
 103
 104 }
 105
 106 static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
 107                           size_t count, loff_t *ppos)
 108 {
 109         ssize_t ret;
 110         char *tmp = NULL;
 111         ssize_t size;
 112
 113         ret = -ENODEV;
 114         if (!ppc_md.nvram_size)
 115                 goto out;
 116
 117         ret = 0;
 118         size = ppc_md.nvram_size();
 119         if (*ppos >= size || size < 0)
 120                 goto out;
 121
 122         count = min_t(size_t, count, size - *ppos);
 123         count = min(count, PAGE_SIZE);
 124
 125         ret = -ENOMEM;
 126         tmp = kmalloc(count, GFP_KERNEL);
 127         if (!tmp)
 128                 goto out;
 129
 130         ret = -EFAULT;
 131         if (copy_from_user(tmp, buf, count))
 132                 goto out;
 133
 134         ret = ppc_md.nvram_write(tmp, count, ppos);
 135
 136 out:
 137         kfree(tmp);
 138         return ret;
 139
 140 }
 141
 142 static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
 143                             unsigned long arg)
 144 {
 145         switch(cmd) {
 146 #ifdef CONFIG_PPC_PMAC
 147         case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
 148                 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
 149         case IOC_NVRAM_GET_OFFSET: {
 150                 int part, offset;
 151
 152                 if (!machine_is(powermac))
 153                         return -EINVAL;
 154                 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
 155                         return -EFAULT;
 156                 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
 157                         return -EINVAL;
 158                 offset = pmac_get_partition(part);
 159                 if (offset < 0)
 160                         return offset;
 161                 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
 162                         return -EFAULT;
 163                 return 0;
 164         }
 165 #endif /* CONFIG_PPC_PMAC */
 166         default:
 167                 return -EINVAL;
 168         }
 169 }
 170
 171 const struct file_operations nvram_fops = {
 172         .owner          = THIS_MODULE,
 173         .llseek         = dev_nvram_llseek,
 174         .read           = dev_nvram_read,
 175         .write          = dev_nvram_write,
 176         .unlocked_ioctl = dev_nvram_ioctl,
 177 };
 178
 179 static struct miscdevice nvram_dev = {
 180         NVRAM_MINOR,
 181         "nvram",
 182         &nvram_fops
 183 };
 184
 185
 186 #ifdef DEBUG_NVRAM
 187 static void __init nvram_print_partitions(char * label)
 188 {
 189         struct list_head * p;
 190         struct nvram_partition * tmp_part;
 191
 192         printk(KERN_WARNING "--------%s---------\n", label);
 193         printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
 194         list_for_each(p, &nvram_part->partition) {
 195                 tmp_part = list_entry(p, struct nvram_partition, partition);
 196                 printk(KERN_WARNING "%4d    \t%02x\t%02x\t%d\t%s\n",
 197                        tmp_part->index, tmp_part->header.signature,
 198                        tmp_part->header.checksum, tmp_part->header.length,
 199                        tmp_part->header.name);
 200         }
 201 }
 202 #endif
 203
 204
 205 static int __init nvram_write_header(struct nvram_partition * part)
 206 {
 207         loff_t tmp_index;
 208         int rc;
 209
 210         tmp_index = part->index;
 211         rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
 212
 213         return rc;
 214 }
 215
 216
 217 static unsigned char __init nvram_checksum(struct nvram_header *p)
 218 {
 219         unsigned int c_sum, c_sum2;
 220         unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
 221         c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
 222
 223         /* The sum may have spilled into the 3rd byte.  Fold it back. */
 224         c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
 225         /* The sum cannot exceed 2 bytes.  Fold it into a checksum */
 226         c_sum2 = (c_sum >> 8) + (c_sum << 8);
 227         c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
 228         return c_sum;
 229 }
 230
 231 static int __init nvram_remove_os_partition(void)
 232 {
 233         struct list_head *i;
 234         struct list_head *j;
 235         struct nvram_partition * part;
 236         struct nvram_partition * cur_part;
 237         int rc;
 238
 239         list_for_each(i, &nvram_part->partition) {
 240                 part = list_entry(i, struct nvram_partition, partition);
 241                 if (part->header.signature != NVRAM_SIG_OS)
 242                         continue;
 243
 244                 /* Make os partition a free partition */
 245                 part->header.signature = NVRAM_SIG_FREE;
 246                 sprintf(part->header.name, "wwwwwwwwwwww");
 247                 part->header.checksum = nvram_checksum(&part->header);
 248
 249                 /* Merge contiguous free partitions backwards */
 250                 list_for_each_prev(j, &part->partition) {
 251                         cur_part = list_entry(j, struct nvram_partition, partition);
 252                         if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
 253                                 break;
 254                         }
 255
 256                         part->header.length += cur_part->header.length;
 257                         part->header.checksum = nvram_checksum(&part->header);
 258                         part->index = cur_part->index;
 259
 260                         list_del(&cur_part->partition);
 261                         kfree(cur_part);
 262                         j = &part->partition; /* fixup our loop */
 263                 }
 264
 265                 /* Merge contiguous free partitions forwards */
 266                 list_for_each(j, &part->partition) {
 267                         cur_part = list_entry(j, struct nvram_partition, partition);
 268                         if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
 269                                 break;
 270                         }
 271
 272                         part->header.length += cur_part->header.length;
 273                         part->header.checksum = nvram_checksum(&part->header);
 274
 275                         list_del(&cur_part->partition);
 276                         kfree(cur_part);
 277                         j = &part->partition; /* fixup our loop */
 278                 }
 279
 280                 rc = nvram_write_header(part);
 281                 if (rc <= 0) {
 282                         printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc);
 283                         return rc;
 284                 }
 285
 286         }
 287
 288         return 0;
 289 }
 290
 291 /* nvram_create_os_partition
 292  *
 293  * Create a OS linux partition to buffer error logs.
 294  * Will create a partition starting at the first free
 295  * space found if space has enough room.
 296  */
 297 static int __init nvram_create_os_partition(void)
 298 {
 299         struct nvram_partition *part;
 300         struct nvram_partition *new_part;
 301         struct nvram_partition *free_part = NULL;
 302         int seq_init[2] = { 0, 0 };
 303         loff_t tmp_index;
 304         long size = 0;
 305         int rc;
 306
 307         /* Find a free partition that will give us the maximum needed size
 308            If can't find one that will give us the minimum size needed */
 309         list_for_each_entry(part, &nvram_part->partition, partition) {
 310                 if (part->header.signature != NVRAM_SIG_FREE)
 311                         continue;
 312
 313                 if (part->header.length >= NVRAM_MAX_REQ) {
 314                         size = NVRAM_MAX_REQ;
 315                         free_part = part;
 316                         break;
 317                 }
 318                 if (!size && part->header.length >= NVRAM_MIN_REQ) {
 319                         size = NVRAM_MIN_REQ;
 320                         free_part = part;
 321                 }
 322         }
 323         if (!size)
 324                 return -ENOSPC;
 325
 326         /* Create our OS partition */
 327         new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
 328         if (!new_part) {
 329                 printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n");
 330                 return -ENOMEM;
 331         }
 332
 333         new_part->index = free_part->index;
 334         new_part->header.signature = NVRAM_SIG_OS;
 335         new_part->header.length = size;
 336         strcpy(new_part->header.name, "ppc64,linux");
 337         new_part->header.checksum = nvram_checksum(&new_part->header);
 338
 339         rc = nvram_write_header(new_part);
 340         if (rc <= 0) {
 341                 printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
 342                                 "failed (%d)\n", rc);
 343                 return rc;
 344         }
 345
 346         /* make sure and initialize to zero the sequence number and the error
 347            type logged */
 348         tmp_index = new_part->index + NVRAM_HEADER_LEN;
 349         rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index);
 350         if (rc <= 0) {
 351                 printk(KERN_ERR "nvram_create_os_partition: nvram_write "
 352                        "failed (%d)\n", rc);
 353                 return rc;
 354         }
 355
 356         nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN;
 357         nvram_error_log_size = ((part->header.length - 1) *
 358                                 NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
 359
 360         list_add_tail(&new_part->partition, &free_part->partition);
 361
 362         if (free_part->header.length <= size) {
 363                 list_del(&free_part->partition);
 364                 kfree(free_part);
 365                 return 0;
 366         }
 367
 368         /* Adjust the partition we stole the space from */
 369         free_part->index += size * NVRAM_BLOCK_LEN;
 370         free_part->header.length -= size;
 371         free_part->header.checksum = nvram_checksum(&free_part->header);
 372
 373         rc = nvram_write_header(free_part);
 374         if (rc <= 0) {
 375                 printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
 376                        "failed (%d)\n", rc);
 377                 return rc;
 378         }
 379
 380         return 0;
 381 }
 382
 383
 384 /* nvram_setup_partition
 385  *
 386  * This will setup the partition we need for buffering the
 387  * error logs and cleanup partitions if needed.
 388  *
 389  * The general strategy is the following:
 390  * 1.) If there is ppc64,linux partition large enough then use it.
 391  * 2.) If there is not a ppc64,linux partition large enough, search
 392  * for a free partition that is large enough.
 393  * 3.) If there is not a free partition large enough remove
 394  * _all_ OS partitions and consolidate the space.
 395  * 4.) Will first try getting a chunk that will satisfy the maximum
 396  * error log size (NVRAM_MAX_REQ).
 397  * 5.) If the max chunk cannot be allocated then try finding a chunk
 398  * that will satisfy the minum needed (NVRAM_MIN_REQ).
 399  */
 400 static int __init nvram_setup_partition(void)
 401 {
 402         struct list_head * p;
 403         struct nvram_partition * part;
 404         int rc;
 405
 406         /* For now, we don't do any of this on pmac, until I
 407          * have figured out if it's worth killing some unused stuffs
 408          * in our nvram, as Apple defined partitions use pretty much
 409          * all of the space
 410          */
 411         if (machine_is(powermac))
 412                 return -ENOSPC;
 413
 414         /* see if we have an OS partition that meets our needs.
 415            will try getting the max we need.  If not we'll delete
 416            partitions and try again. */
 417         list_for_each(p, &nvram_part->partition) {
 418                 part = list_entry(p, struct nvram_partition, partition);
 419                 if (part->header.signature != NVRAM_SIG_OS)
 420                         continue;
 421
 422                 if (strcmp(part->header.name, "ppc64,linux"))
 423                         continue;
 424
 425                 if (part->header.length >= NVRAM_MIN_REQ) {
 426                         /* found our partition */
 427                         nvram_error_log_index = part->index + NVRAM_HEADER_LEN;
 428                         nvram_error_log_size = ((part->header.length - 1) *
 429                                                 NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
 430                         return 0;
 431                 }
 432         }
 433
 434         /* try creating a partition with the free space we have */
 435         rc = nvram_create_os_partition();
 436         if (!rc) {
 437                 return 0;
 438         }
 439
 440         /* need to free up some space */
 441         rc = nvram_remove_os_partition();
 442         if (rc) {
 443                 return rc;
 444         }
 445
 446         /* create a partition in this new space */
 447         rc = nvram_create_os_partition();
 448         if (rc) {
 449                 printk(KERN_ERR "nvram_create_os_partition: Could not find a "
 450                        "NVRAM partition large enough\n");
 451                 return rc;
 452         }
 453
 454         return 0;
 455 }
 456
 457
 458 static int __init nvram_scan_partitions(void)
 459 {
 460         loff_t cur_index = 0;
 461         struct nvram_header phead;
 462         struct nvram_partition * tmp_part;
 463         unsigned char c_sum;
 464         char * header;
 465         int total_size;
 466         int err;
 467
 468         if (ppc_md.nvram_size == NULL)
 469                 return -ENODEV;
 470         total_size = ppc_md.nvram_size();
 471
 472         header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
 473         if (!header) {
 474                 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
 475                 return -ENOMEM;
 476         }
 477
 478         while (cur_index < total_size) {
 479
 480                 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
 481                 if (err != NVRAM_HEADER_LEN) {
 482                         printk(KERN_ERR "nvram_scan_partitions: Error parsing "
 483                                "nvram partitions\n");
 484                         goto out;
 485                 }
 486
 487                 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
 488
 489                 memcpy(&phead, header, NVRAM_HEADER_LEN);
 490
 491                 err = 0;
 492                 c_sum = nvram_checksum(&phead);
 493                 if (c_sum != phead.checksum) {
 494                         printk(KERN_WARNING "WARNING: nvram partition checksum"
 495                                " was %02x, should be %02x!\n",
 496                                phead.checksum, c_sum);
 497                         printk(KERN_WARNING "Terminating nvram partition scan\n");
 498                         goto out;
 499                 }
 500                 if (!phead.length) {
 501                         printk(KERN_WARNING "WARNING: nvram corruption "
 502                                "detected: 0-length partition\n");
 503                         goto out;
 504                 }
 505                 tmp_part = (struct nvram_partition *)
 506                         kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
 507                 err = -ENOMEM;
 508                 if (!tmp_part) {
 509                         printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
 510                         goto out;
 511                 }
 512
 513                 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
 514                 tmp_part->index = cur_index;
 515                 list_add_tail(&tmp_part->partition, &nvram_part->partition);
 516
 517                 cur_index += phead.length * NVRAM_BLOCK_LEN;
 518         }
 519         err = 0;
 520
 521  out:
 522         kfree(header);
 523         return err;
 524 }
 525
 526 static int __init nvram_init(void)
 527 {
 528         int error;
 529         int rc;
 530
 531         if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
 532                 return  -ENODEV;
 533
 534         rc = misc_register(&nvram_dev);
 535         if (rc != 0) {
 536                 printk(KERN_ERR "nvram_init: failed to register device\n");
 537                 return rc;
 538         }
 539
 540         /* initialize our anchor for the nvram partition list */
 541         nvram_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
 542         if (!nvram_part) {
 543                 printk(KERN_ERR "nvram_init: Failed kmalloc\n");
 544                 return -ENOMEM;
 545         }
 546         INIT_LIST_HEAD(&nvram_part->partition);
 547
 548         /* Get all the NVRAM partitions */
 549         error = nvram_scan_partitions();
 550         if (error) {
 551                 printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
 552                 return error;
 553         }
 554
 555         if(nvram_setup_partition())
 556                 printk(KERN_WARNING "nvram_init: Could not find nvram partition"
 557                        " for nvram buffered error logging.\n");
 558
 559 #ifdef DEBUG_NVRAM
 560         nvram_print_partitions("NVRAM Partitions");
 561 #endif
 562
 563         return rc;
 564 }
 565
 566 void __exit nvram_cleanup(void)
 567 {
 568         misc_deregister( &nvram_dev );
 569 }
 570
 571
 572 #ifdef CONFIG_PPC_PSERIES
 573
 574 /* nvram_write_error_log
 575  *
 576  * We need to buffer the error logs into nvram to ensure that we have
 577  * the failure information to decode.  If we have a severe error there
 578  * is no way to guarantee that the OS or the machine is in a state to
 579  * get back to user land and write the error to disk.  For example if
 580  * the SCSI device driver causes a Machine Check by writing to a bad
 581  * IO address, there is no way of guaranteeing that the device driver
 582  * is in any state that is would also be able to write the error data
 583  * captured to disk, thus we buffer it in NVRAM for analysis on the
 584  * next boot.
 585  *
 586  * In NVRAM the partition containing the error log buffer will looks like:
 587  * Header (in bytes):
 588  * +-----------+----------+--------+------------+------------------+
 589  * | signature | checksum | length | name       | data             |
 590  * |0          |1         |2      3|4         15|16        length-1|
 591  * +-----------+----------+--------+------------+------------------+
 592  *
 593  * The 'data' section would look like (in bytes):
 594  * +--------------+------------+-----------------------------------+
 595  * | event_logged | sequence # | error log                         |
 596  * |0            3|4          7|8            nvram_error_log_size-1|
 597  * +--------------+------------+-----------------------------------+
 598  *
 599  * event_logged: 0 if event has not been logged to syslog, 1 if it has
 600  * sequence #: The unique sequence # for each event. (until it wraps)
 601  * error log: The error log from event_scan
 602  */
 603 int nvram_write_error_log(char * buff, int length,
 604                           unsigned int err_type, unsigned int error_log_cnt)
 605 {
 606         int rc;
 607         loff_t tmp_index;
 608         struct err_log_info info;
 609
 610         if (nvram_error_log_index == -1) {
 611                 return -ESPIPE;
 612         }
 613
 614         if (length > nvram_error_log_size) {
 615                 length = nvram_error_log_size;
 616         }
 617
 618         info.error_type = err_type;
 619         info.seq_num = error_log_cnt;
 620
 621         tmp_index = nvram_error_log_index;
 622
 623         rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
 624         if (rc <= 0) {
 625                 printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
 626                 return rc;
 627         }
 628
 629         rc = ppc_md.nvram_write(buff, length, &tmp_index);
 630         if (rc <= 0) {
 631                 printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
 632                 return rc;
 633         }
 634
 635         return 0;
 636 }
 637
 638 /* nvram_read_error_log
 639  *
 640  * Reads nvram for error log for at most 'length'
 641  */
 642 int nvram_read_error_log(char * buff, int length,
 643                          unsigned int * err_type, unsigned int * error_log_cnt)
 644 {
 645         int rc;
 646         loff_t tmp_index;
 647         struct err_log_info info;
 648
 649         if (nvram_error_log_index == -1)
 650                 return -1;
 651
 652         if (length > nvram_error_log_size)
 653                 length = nvram_error_log_size;
 654
 655         tmp_index = nvram_error_log_index;
 656
 657         rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
 658         if (rc <= 0) {
 659                 printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
 660                 return rc;
 661         }
 662
 663         rc = ppc_md.nvram_read(buff, length, &tmp_index);
 664         if (rc <= 0) {
 665                 printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
 666                 return rc;
 667         }
 668
 669         *error_log_cnt = info.seq_num;
 670         *err_type = info.error_type;
 671
 672         return 0;
 673 }
 674
 675 /* This doesn't actually zero anything, but it sets the event_logged
 676  * word to tell that this event is safely in syslog.
 677  */
 678 int nvram_clear_error_log(void)
 679 {
 680         loff_t tmp_index;
 681         int clear_word = ERR_FLAG_ALREADY_LOGGED;
 682         int rc;
 683
 684         if (nvram_error_log_index == -1)
 685                 return -1;
 686
 687         tmp_index = nvram_error_log_index;
 688
 689         rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
 690         if (rc <= 0) {
 691                 printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
 692                 return rc;
 693         }
 694
 695         return 0;
 696 }
 697
 698 #endif /* CONFIG_PPC_PSERIES */
 699
 700 module_init(nvram_init);
 701 module_exit(nvram_cleanup);
 702 MODULE_LICENSE("GPL");