drivers/watchdog/hpwdt.c

   1 /*
   2  *      HP WatchDog Driver
   3  *      based on
   4  *
   5  *      SoftDog 0.05:   A Software Watchdog Device
   6  *
   7  *      (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
   8  *      Thomas Mingarelli <thomas.mingarelli@hp.com>
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      version 2 as published by the Free Software Foundation
  13  *
  14  */
  15
  16 #include <linux/device.h>
  17 #include <linux/fs.h>
  18 #include <linux/init.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/io.h>
  21 #include <linux/irq.h>
  22 #include <linux/nmi.h>
  23 #include <linux/kernel.h>
  24 #include <linux/miscdevice.h>
  25 #include <linux/mm.h>
  26 #include <linux/module.h>
  27 #include <linux/kdebug.h>
  28 #include <linux/moduleparam.h>
  29 #include <linux/notifier.h>
  30 #include <linux/pci.h>
  31 #include <linux/pci_ids.h>
  32 #include <linux/reboot.h>
  33 #include <linux/sched.h>
  34 #include <linux/timer.h>
  35 #include <linux/types.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/watchdog.h>
  38 #include <linux/dmi.h>
  39 #include <linux/efi.h>
  40 #include <linux/string.h>
  41 #include <linux/bootmem.h>
  42 #include <linux/slab.h>
  43 #include <asm/desc.h>
  44 #include <asm/cacheflush.h>
  45
  46 #define PCI_BIOS32_SD_VALUE             0x5F32335F      /* "_32_" */
  47 #define CRU_BIOS_SIGNATURE_VALUE        0x55524324
  48 #define PCI_BIOS32_PARAGRAPH_LEN        16
  49 #define PCI_ROM_BASE1                   0x000F0000
  50 #define ROM_SIZE                        0x10000
  51 #define HPWDT_VERSION                   "1.1.1"
  52
  53 struct bios32_service_dir {
  54         u32 signature;
  55         u32 entry_point;
  56         u8 revision;
  57         u8 length;
  58         u8 checksum;
  59         u8 reserved[5];
  60 };
  61
  62 /* type 212 */
  63 struct smbios_cru64_info {
  64         u8 type;
  65         u8 byte_length;
  66         u16 handle;
  67         u32 signature;
  68         u64 physical_address;
  69         u32 double_length;
  70         u32 double_offset;
  71 };
  72 #define SMBIOS_CRU64_INFORMATION        212
  73
  74 struct cmn_registers {
  75         union {
  76                 struct {
  77                         u8 ral;
  78                         u8 rah;
  79                         u16 rea2;
  80                 };
  81                 u32 reax;
  82         } u1;
  83         union {
  84                 struct {
  85                         u8 rbl;
  86                         u8 rbh;
  87                         u8 reb2l;
  88                         u8 reb2h;
  89                 };
  90                 u32 rebx;
  91         } u2;
  92         union {
  93                 struct {
  94                         u8 rcl;
  95                         u8 rch;
  96                         u16 rec2;
  97                 };
  98                 u32 recx;
  99         } u3;
 100         union {
 101                 struct {
 102                         u8 rdl;
 103                         u8 rdh;
 104                         u16 red2;
 105                 };
 106                 u32 redx;
 107         } u4;
 108
 109         u32 resi;
 110         u32 redi;
 111         u16 rds;
 112         u16 res;
 113         u32 reflags;
 114 }  __attribute__((packed));
 115
 116 #define DEFAULT_MARGIN  30
 117 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
 118 static unsigned int reload;                     /* the computed soft_margin */
 119 static int nowayout = WATCHDOG_NOWAYOUT;
 120 static char expect_release;
 121 static unsigned long hpwdt_is_open;
 122 static unsigned int allow_kdump;
 123 static unsigned int hpwdt_nmi_sourcing;
 124 static unsigned int priority;           /* hpwdt at end of die_notify list */
 125
 126 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
 127 static unsigned long __iomem *hpwdt_timer_reg;
 128 static unsigned long __iomem *hpwdt_timer_con;
 129
 130 static DEFINE_SPINLOCK(rom_lock);
 131
 132 static void *cru_rom_addr;
 133
 134 static struct cmn_registers cmn_regs;
 135
 136 static struct pci_device_id hpwdt_devices[] = {
 137         { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },
 138         { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },
 139         {0},                    /* terminate list */
 140 };
 141 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
 142
 143 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
 144                                                 unsigned long *pRomEntry);
 145
 146 #ifndef CONFIG_X86_64
 147 /* --32 Bit Bios------------------------------------------------------------ */
 148
 149 #define HPWDT_ARCH      32
 150
 151 asm(".text                          \n\t"
 152     ".align 4                       \n"
 153     "asminline_call:                \n\t"
 154     "pushl       %ebp               \n\t"
 155     "movl        %esp, %ebp         \n\t"
 156     "pusha                          \n\t"
 157     "pushf                          \n\t"
 158     "push        %es                \n\t"
 159     "push        %ds                \n\t"
 160     "pop         %es                \n\t"
 161     "movl        8(%ebp),%eax       \n\t"
 162     "movl        4(%eax),%ebx       \n\t"
 163     "movl        8(%eax),%ecx       \n\t"
 164     "movl        12(%eax),%edx      \n\t"
 165     "movl        16(%eax),%esi      \n\t"
 166     "movl        20(%eax),%edi      \n\t"
 167     "movl        (%eax),%eax        \n\t"
 168     "push        %cs                \n\t"
 169     "call        *12(%ebp)          \n\t"
 170     "pushf                          \n\t"
 171     "pushl       %eax               \n\t"
 172     "movl        8(%ebp),%eax       \n\t"
 173     "movl        %ebx,4(%eax)       \n\t"
 174     "movl        %ecx,8(%eax)       \n\t"
 175     "movl        %edx,12(%eax)      \n\t"
 176     "movl        %esi,16(%eax)      \n\t"
 177     "movl        %edi,20(%eax)      \n\t"
 178     "movw        %ds,24(%eax)       \n\t"
 179     "movw        %es,26(%eax)       \n\t"
 180     "popl        %ebx               \n\t"
 181     "movl        %ebx,(%eax)        \n\t"
 182     "popl        %ebx               \n\t"
 183     "movl        %ebx,28(%eax)      \n\t"
 184     "pop         %es                \n\t"
 185     "popf                           \n\t"
 186     "popa                           \n\t"
 187     "leave                          \n\t"
 188     "ret                            \n\t"
 189     ".previous");
 190
 191
 192 /*
 193  *      cru_detect
 194  *
 195  *      Routine Description:
 196  *      This function uses the 32-bit BIOS Service Directory record to
 197  *      search for a $CRU record.
 198  *
 199  *      Return Value:
 200  *      0        :  SUCCESS
 201  *      <0       :  FAILURE
 202  */
 203 static int __devinit cru_detect(unsigned long map_entry,
 204         unsigned long map_offset)
 205 {
 206         void *bios32_map;
 207         unsigned long *bios32_entrypoint;
 208         unsigned long cru_physical_address;
 209         unsigned long cru_length;
 210         unsigned long physical_bios_base = 0;
 211         unsigned long physical_bios_offset = 0;
 212         int retval = -ENODEV;
 213
 214         bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
 215
 216         if (bios32_map == NULL)
 217                 return -ENODEV;
 218
 219         bios32_entrypoint = bios32_map + map_offset;
 220
 221         cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 222
 223         asminline_call(&cmn_regs, bios32_entrypoint);
 224
 225         if (cmn_regs.u1.ral != 0) {
 226                 printk(KERN_WARNING
 227                         "hpwdt: Call succeeded but with an error: 0x%x\n",
 228                         cmn_regs.u1.ral);
 229         } else {
 230                 physical_bios_base = cmn_regs.u2.rebx;
 231                 physical_bios_offset = cmn_regs.u4.redx;
 232                 cru_length = cmn_regs.u3.recx;
 233                 cru_physical_address =
 234                         physical_bios_base + physical_bios_offset;
 235
 236                 /* If the values look OK, then map it in. */
 237                 if ((physical_bios_base + physical_bios_offset)) {
 238                         cru_rom_addr =
 239                                 ioremap(cru_physical_address, cru_length);
 240                         if (cru_rom_addr)
 241                                 retval = 0;
 242                 }
 243
 244                 printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
 245                         physical_bios_base);
 246                 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
 247                         physical_bios_offset);
 248                 printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
 249                         cru_length);
 250                 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
 251                         (unsigned int)&cru_rom_addr);
 252         }
 253         iounmap(bios32_map);
 254         return retval;
 255 }
 256
 257 /*
 258  *      bios_checksum
 259  */
 260 static int __devinit bios_checksum(const char __iomem *ptr, int len)
 261 {
 262         char sum = 0;
 263         int i;
 264
 265         /*
 266          * calculate checksum of size bytes. This should add up
 267          * to zero if we have a valid header.
 268          */
 269         for (i = 0; i < len; i++)
 270                 sum += ptr[i];
 271
 272         return ((sum == 0) && (len > 0));
 273 }
 274
 275 /*
 276  *      bios32_present
 277  *
 278  *      Routine Description:
 279  *      This function finds the 32-bit BIOS Service Directory
 280  *
 281  *      Return Value:
 282  *      0        :  SUCCESS
 283  *      <0       :  FAILURE
 284  */
 285 static int __devinit bios32_present(const char __iomem *p)
 286 {
 287         struct bios32_service_dir *bios_32_ptr;
 288         int length;
 289         unsigned long map_entry, map_offset;
 290
 291         bios_32_ptr = (struct bios32_service_dir *) p;
 292
 293         /*
 294          * Search for signature by checking equal to the swizzled value
 295          * instead of calling another routine to perform a strcmp.
 296          */
 297         if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
 298                 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
 299                 if (bios_checksum(p, length)) {
 300                         /*
 301                          * According to the spec, we're looking for the
 302                          * first 4KB-aligned address below the entrypoint
 303                          * listed in the header. The Service Directory code
 304                          * is guaranteed to occupy no more than 2 4KB pages.
 305                          */
 306                         map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
 307                         map_offset = bios_32_ptr->entry_point - map_entry;
 308
 309                         return cru_detect(map_entry, map_offset);
 310                 }
 311         }
 312         return -ENODEV;
 313 }
 314
 315 static int __devinit detect_cru_service(void)
 316 {
 317         char __iomem *p, *q;
 318         int rc = -1;
 319
 320         /*
 321          * Search from 0x0f0000 through 0x0fffff, inclusive.
 322          */
 323         p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
 324         if (p == NULL)
 325                 return -ENOMEM;
 326
 327         for (q = p; q < p + ROM_SIZE; q += 16) {
 328                 rc = bios32_present(q);
 329                 if (!rc)
 330                         break;
 331         }
 332         iounmap(p);
 333         return rc;
 334 }
 335
 336 #else
 337 /* --64 Bit Bios------------------------------------------------------------ */
 338
 339 #define HPWDT_ARCH      64
 340
 341 asm(".text                      \n\t"
 342     ".align 4                   \n"
 343     "asminline_call:            \n\t"
 344     "pushq      %rbp            \n\t"
 345     "movq       %rsp, %rbp      \n\t"
 346     "pushq      %rax            \n\t"
 347     "pushq      %rbx            \n\t"
 348     "pushq      %rdx            \n\t"
 349     "pushq      %r12            \n\t"
 350     "pushq      %r9             \n\t"
 351     "movq       %rsi, %r12      \n\t"
 352     "movq       %rdi, %r9       \n\t"
 353     "movl       4(%r9),%ebx     \n\t"
 354     "movl       8(%r9),%ecx     \n\t"
 355     "movl       12(%r9),%edx    \n\t"
 356     "movl       16(%r9),%esi    \n\t"
 357     "movl       20(%r9),%edi    \n\t"
 358     "movl       (%r9),%eax      \n\t"
 359     "call       *%r12           \n\t"
 360     "pushfq                     \n\t"
 361     "popq        %r12           \n\t"
 362     "movl       %eax, (%r9)     \n\t"
 363     "movl       %ebx, 4(%r9)    \n\t"
 364     "movl       %ecx, 8(%r9)    \n\t"
 365     "movl       %edx, 12(%r9)   \n\t"
 366     "movl       %esi, 16(%r9)   \n\t"
 367     "movl       %edi, 20(%r9)   \n\t"
 368     "movq       %r12, %rax      \n\t"
 369     "movl       %eax, 28(%r9)   \n\t"
 370     "popq       %r9             \n\t"
 371     "popq       %r12            \n\t"
 372     "popq       %rdx            \n\t"
 373     "popq       %rbx            \n\t"
 374     "popq       %rax            \n\t"
 375     "leave                      \n\t"
 376     "ret                        \n\t"
 377     ".previous");
 378
 379 /*
 380  *      dmi_find_cru
 381  *
 382  *      Routine Description:
 383  *      This function checks whether or not a SMBIOS/DMI record is
 384  *      the 64bit CRU info or not
 385  */
 386 static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
 387 {
 388         struct smbios_cru64_info *smbios_cru64_ptr;
 389         unsigned long cru_physical_address;
 390
 391         if (dm->type == SMBIOS_CRU64_INFORMATION) {
 392                 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
 393                 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
 394                         cru_physical_address =
 395                                 smbios_cru64_ptr->physical_address +
 396                                 smbios_cru64_ptr->double_offset;
 397                         cru_rom_addr = ioremap(cru_physical_address,
 398                                 smbios_cru64_ptr->double_length);
 399                         set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
 400                                 smbios_cru64_ptr->double_length >> PAGE_SHIFT);
 401                 }
 402         }
 403 }
 404
 405 static int __devinit detect_cru_service(void)
 406 {
 407         cru_rom_addr = NULL;
 408
 409         dmi_walk(dmi_find_cru, NULL);
 410
 411         /* if cru_rom_addr has been set then we found a CRU service */
 412         return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
 413 }
 414
 415 /* ------------------------------------------------------------------------- */
 416
 417 #endif
 418
 419 /*
 420  *      Watchdog operations
 421  */
 422 static void hpwdt_start(void)
 423 {
 424         reload = (soft_margin * 1000) / 128;
 425         iowrite16(reload, hpwdt_timer_reg);
 426         iowrite16(0x85, hpwdt_timer_con);
 427 }
 428
 429 static void hpwdt_stop(void)
 430 {
 431         unsigned long data;
 432
 433         data = ioread16(hpwdt_timer_con);
 434         data &= 0xFE;
 435         iowrite16(data, hpwdt_timer_con);
 436 }
 437
 438 static void hpwdt_ping(void)
 439 {
 440         iowrite16(reload, hpwdt_timer_reg);
 441 }
 442
 443 static int hpwdt_change_timer(int new_margin)
 444 {
 445         /* Arbitrary, can't find the card's limits */
 446         if (new_margin < 30 || new_margin > 600) {
 447                 printk(KERN_WARNING
 448                         "hpwdt: New value passed in is invalid: %d seconds.\n",
 449                         new_margin);
 450                 return -EINVAL;
 451         }
 452
 453         soft_margin = new_margin;
 454         printk(KERN_DEBUG
 455                 "hpwdt: New timer passed in is %d seconds.\n",
 456                 new_margin);
 457         reload = (soft_margin * 1000) / 128;
 458
 459         return 0;
 460 }
 461
 462 /*
 463  *      NMI Handler
 464  */
 465 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
 466                                 void *data)
 467 {
 468         unsigned long rom_pl;
 469         static int die_nmi_called;
 470
 471         if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
 472                 return NOTIFY_OK;
 473
 474         if (hpwdt_nmi_sourcing) {
 475                 spin_lock_irqsave(&rom_lock, rom_pl);
 476                 if (!die_nmi_called)
 477                         asminline_call(&cmn_regs, cru_rom_addr);
 478                 die_nmi_called = 1;
 479                 spin_unlock_irqrestore(&rom_lock, rom_pl);
 480                 if (cmn_regs.u1.ral == 0) {
 481                         printk(KERN_WARNING "hpwdt: An NMI occurred, "
 482                                 "but unable to determine source.\n");
 483                 } else {
 484                         if (allow_kdump)
 485                                 hpwdt_stop();
 486                         panic("An NMI occurred, please see the Integrated "
 487                                 "Management Log for details.\n");
 488                 }
 489         }
 490         return NOTIFY_OK;
 491 }
 492
 493 /*
 494  *      /dev/watchdog handling
 495  */
 496 static int hpwdt_open(struct inode *inode, struct file *file)
 497 {
 498         /* /dev/watchdog can only be opened once */
 499         if (test_and_set_bit(0, &hpwdt_is_open))
 500                 return -EBUSY;
 501
 502         /* Start the watchdog */
 503         hpwdt_start();
 504         hpwdt_ping();
 505
 506         return nonseekable_open(inode, file);
 507 }
 508
 509 static int hpwdt_release(struct inode *inode, struct file *file)
 510 {
 511         /* Stop the watchdog */
 512         if (expect_release == 42) {
 513                 hpwdt_stop();
 514         } else {
 515                 printk(KERN_CRIT
 516                         "hpwdt: Unexpected close, not stopping watchdog!\n");
 517                 hpwdt_ping();
 518         }
 519
 520         expect_release = 0;
 521
 522         /* /dev/watchdog is being closed, make sure it can be re-opened */
 523         clear_bit(0, &hpwdt_is_open);
 524
 525         return 0;
 526 }
 527
 528 static ssize_t hpwdt_write(struct file *file, const char __user *data,
 529         size_t len, loff_t *ppos)
 530 {
 531         /* See if we got the magic character 'V' and reload the timer */
 532         if (len) {
 533                 if (!nowayout) {
 534                         size_t i;
 535
 536                         /* note: just in case someone wrote the magic character
 537                          * five months ago... */
 538                         expect_release = 0;
 539
 540                         /* scan to see whether or not we got the magic char. */
 541                         for (i = 0; i != len; i++) {
 542                                 char c;
 543                                 if (get_user(c, data + i))
 544                                         return -EFAULT;
 545                                 if (c == 'V')
 546                                         expect_release = 42;
 547                         }
 548                 }
 549
 550                 /* someone wrote to us, we should reload the timer */
 551                 hpwdt_ping();
 552         }
 553
 554         return len;
 555 }
 556
 557 static struct watchdog_info ident = {
 558         .options = WDIOF_SETTIMEOUT |
 559                    WDIOF_KEEPALIVEPING |
 560                    WDIOF_MAGICCLOSE,
 561         .identity = "HP iLO2 HW Watchdog Timer",
 562 };
 563
 564 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
 565         unsigned long arg)
 566 {
 567         void __user *argp = (void __user *)arg;
 568         int __user *p = argp;
 569         int new_margin;
 570         int ret = -ENOTTY;
 571
 572         switch (cmd) {
 573         case WDIOC_GETSUPPORT:
 574                 ret = 0;
 575                 if (copy_to_user(argp, &ident, sizeof(ident)))
 576                         ret = -EFAULT;
 577                 break;
 578
 579         case WDIOC_GETSTATUS:
 580         case WDIOC_GETBOOTSTATUS:
 581                 ret = put_user(0, p);
 582                 break;
 583
 584         case WDIOC_KEEPALIVE:
 585                 hpwdt_ping();
 586                 ret = 0;
 587                 break;
 588
 589         case WDIOC_SETTIMEOUT:
 590                 ret = get_user(new_margin, p);
 591                 if (ret)
 592                         break;
 593
 594                 ret = hpwdt_change_timer(new_margin);
 595                 if (ret)
 596                         break;
 597
 598                 hpwdt_ping();
 599                 /* Fall */
 600         case WDIOC_GETTIMEOUT:
 601                 ret = put_user(soft_margin, p);
 602                 break;
 603         }
 604         return ret;
 605 }
 606
 607 /*
 608  *      Kernel interfaces
 609  */
 610 static const struct file_operations hpwdt_fops = {
 611         .owner = THIS_MODULE,
 612         .llseek = no_llseek,
 613         .write = hpwdt_write,
 614         .unlocked_ioctl = hpwdt_ioctl,
 615         .open = hpwdt_open,
 616         .release = hpwdt_release,
 617 };
 618
 619 static struct miscdevice hpwdt_miscdev = {
 620         .minor = WATCHDOG_MINOR,
 621         .name = "watchdog",
 622         .fops = &hpwdt_fops,
 623 };
 624
 625 static struct notifier_block die_notifier = {
 626         .notifier_call = hpwdt_pretimeout,
 627         .priority = 0,
 628 };
 629
 630 /*
 631  *      Init & Exit
 632  */
 633
 634 #ifdef ARCH_HAS_NMI_WATCHDOG
 635 static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
 636 {
 637         /*
 638          * If nmi_watchdog is turned off then we can turn on
 639          * our nmi sourcing capability.
 640          */
 641         if (!nmi_watchdog_active())
 642                 hpwdt_nmi_sourcing = 1;
 643         else
 644                 dev_warn(&dev->dev, "NMI sourcing is disabled. To enable this "
 645                         "functionality you must reboot with nmi_watchdog=0 "
 646                         "and load the hpwdt driver with priority=1.\n");
 647 }
 648 #else
 649 static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
 650 {
 651         dev_warn(&dev->dev, "NMI sourcing is disabled. "
 652                 "Your kernel does not support a NMI Watchdog.\n");
 653 }
 654 #endif
 655
 656 static int __devinit hpwdt_init_one(struct pci_dev *dev,
 657                                         const struct pci_device_id *ent)
 658 {
 659         int retval;
 660
 661         /*
 662          * Check if we can do NMI sourcing or not
 663          */
 664         hpwdt_check_nmi_sourcing(dev);
 665
 666         /*
 667          * First let's find out if we are on an iLO2 server. We will
 668          * not run on a legacy ASM box.
 669          * So we only support the G5 ProLiant servers and higher.
 670          */
 671         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
 672                 dev_warn(&dev->dev,
 673                         "This server does not have an iLO2 ASIC.\n");
 674                 return -ENODEV;
 675         }
 676
 677         if (pci_enable_device(dev)) {
 678                 dev_warn(&dev->dev,
 679                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 680                         ent->vendor, ent->device);
 681                 return -ENODEV;
 682         }
 683
 684         pci_mem_addr = pci_iomap(dev, 1, 0x80);
 685         if (!pci_mem_addr) {
 686                 dev_warn(&dev->dev,
 687                         "Unable to detect the iLO2 server memory.\n");
 688                 retval = -ENOMEM;
 689                 goto error_pci_iomap;
 690         }
 691         hpwdt_timer_reg = pci_mem_addr + 0x70;
 692         hpwdt_timer_con = pci_mem_addr + 0x72;
 693
 694         /* Make sure that we have a valid soft_margin */
 695         if (hpwdt_change_timer(soft_margin))
 696                 hpwdt_change_timer(DEFAULT_MARGIN);
 697
 698         /*
 699          * We need to map the ROM to get the CRU service.
 700          * For 32 bit Operating Systems we need to go through the 32 Bit
 701          * BIOS Service Directory
 702          * For 64 bit Operating Systems we get that service through SMBIOS.
 703          */
 704         retval = detect_cru_service();
 705         if (retval < 0) {
 706                 dev_warn(&dev->dev,
 707                         "Unable to detect the %d Bit CRU Service.\n",
 708                         HPWDT_ARCH);
 709                 goto error_get_cru;
 710         }
 711
 712         /*
 713          * We know this is the only CRU call we need to make so lets keep as
 714          * few instructions as possible once the NMI comes in.
 715          */
 716         cmn_regs.u1.rah = 0x0D;
 717         cmn_regs.u1.ral = 0x02;
 718
 719         /*
 720          * If the priority is set to 1, then we will be put first on the
 721          * die notify list to handle a critical NMI. The default is to
 722          * be last so other users of the NMI signal can function.
 723          */
 724         if (priority)
 725                 die_notifier.priority = 0x7FFFFFFF;
 726
 727         retval = register_die_notifier(&die_notifier);
 728         if (retval != 0) {
 729                 dev_warn(&dev->dev,
 730                         "Unable to register a die notifier (err=%d).\n",
 731                         retval);
 732                 goto error_die_notifier;
 733         }
 734
 735         retval = misc_register(&hpwdt_miscdev);
 736         if (retval < 0) {
 737                 dev_warn(&dev->dev,
 738                         "Unable to register miscdev on minor=%d (err=%d).\n",
 739                         WATCHDOG_MINOR, retval);
 740                 goto error_misc_register;
 741         }
 742
 743         printk(KERN_INFO
 744                 "hp Watchdog Timer Driver: %s"
 745                 ", timer margin: %d seconds (nowayout=%d)"
 746                 ", allow kernel dump: %s (default = 0/OFF)"
 747                 ", priority: %s (default = 0/LAST).\n",
 748                 HPWDT_VERSION, soft_margin, nowayout,
 749                 (allow_kdump == 0) ? "OFF" : "ON",
 750                 (priority == 0) ? "LAST" : "FIRST");
 751
 752         return 0;
 753
 754 error_misc_register:
 755         unregister_die_notifier(&die_notifier);
 756 error_die_notifier:
 757         if (cru_rom_addr)
 758                 iounmap(cru_rom_addr);
 759 error_get_cru:
 760         pci_iounmap(dev, pci_mem_addr);
 761 error_pci_iomap:
 762         pci_disable_device(dev);
 763         return retval;
 764 }
 765
 766 static void __devexit hpwdt_exit(struct pci_dev *dev)
 767 {
 768         if (!nowayout)
 769                 hpwdt_stop();
 770
 771         misc_deregister(&hpwdt_miscdev);
 772         unregister_die_notifier(&die_notifier);
 773
 774         if (cru_rom_addr)
 775                 iounmap(cru_rom_addr);
 776         pci_iounmap(dev, pci_mem_addr);
 777         pci_disable_device(dev);
 778 }
 779
 780 static struct pci_driver hpwdt_driver = {
 781         .name = "hpwdt",
 782         .id_table = hpwdt_devices,
 783         .probe = hpwdt_init_one,
 784         .remove = __devexit_p(hpwdt_exit),
 785 };
 786
 787 static void __exit hpwdt_cleanup(void)
 788 {
 789         pci_unregister_driver(&hpwdt_driver);
 790 }
 791
 792 static int __init hpwdt_init(void)
 793 {
 794         return pci_register_driver(&hpwdt_driver);
 795 }
 796
 797 MODULE_AUTHOR("Tom Mingarelli");
 798 MODULE_DESCRIPTION("hp watchdog driver");
 799 MODULE_LICENSE("GPL");
 800 MODULE_VERSION(HPWDT_VERSION);
 801 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 802
 803 module_param(soft_margin, int, 0);
 804 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 805
 806 module_param(allow_kdump, int, 0);
 807 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
 808
 809 module_param(nowayout, int, 0);
 810 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 811                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 812
 813 module_param(priority, int, 0);
 814 MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
 815                 " (default = 0/Last)\n");
 816
 817 module_init(hpwdt_init);
 818 module_exit(hpwdt_cleanup);