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/io.h>
  20 #include <linux/bitops.h>
  21 #include <linux/kernel.h>
  22 #include <linux/miscdevice.h>
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/pci.h>
  26 #include <linux/pci_ids.h>
  27 #include <linux/types.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/watchdog.h>
  30 #include <linux/dmi.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/nmi.h>
  33 #include <linux/kdebug.h>
  34 #include <linux/notifier.h>
  35 #include <asm/cacheflush.h>
  36
  37 #define HPWDT_VERSION                   "1.1.1"
  38 #define DEFAULT_MARGIN                  30
  39
  40 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
  41 static unsigned int reload;                     /* the computed soft_margin */
  42 static int nowayout = WATCHDOG_NOWAYOUT;
  43 static char expect_release;
  44 static unsigned long hpwdt_is_open;
  45
  46 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
  47 static unsigned long __iomem *hpwdt_timer_reg;
  48 static unsigned long __iomem *hpwdt_timer_con;
  49
  50 static struct pci_device_id hpwdt_devices[] = {
  51         { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },   /* iLO2 */
  52         { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },       /* iLO3 */
  53         {0},                    /* terminate list */
  54 };
  55 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
  56
  57 #define PCI_BIOS32_SD_VALUE             0x5F32335F      /* "_32_" */
  58 #define CRU_BIOS_SIGNATURE_VALUE        0x55524324
  59 #define PCI_BIOS32_PARAGRAPH_LEN        16
  60 #define PCI_ROM_BASE1                   0x000F0000
  61 #define ROM_SIZE                        0x10000
  62
  63 struct bios32_service_dir {
  64         u32 signature;
  65         u32 entry_point;
  66         u8 revision;
  67         u8 length;
  68         u8 checksum;
  69         u8 reserved[5];
  70 };
  71
  72 /* type 212 */
  73 struct smbios_cru64_info {
  74         u8 type;
  75         u8 byte_length;
  76         u16 handle;
  77         u32 signature;
  78         u64 physical_address;
  79         u32 double_length;
  80         u32 double_offset;
  81 };
  82 #define SMBIOS_CRU64_INFORMATION        212
  83
  84 struct cmn_registers {
  85         union {
  86                 struct {
  87                         u8 ral;
  88                         u8 rah;
  89                         u16 rea2;
  90                 };
  91                 u32 reax;
  92         } u1;
  93         union {
  94                 struct {
  95                         u8 rbl;
  96                         u8 rbh;
  97                         u8 reb2l;
  98                         u8 reb2h;
  99                 };
 100                 u32 rebx;
 101         } u2;
 102         union {
 103                 struct {
 104                         u8 rcl;
 105                         u8 rch;
 106                         u16 rec2;
 107                 };
 108                 u32 recx;
 109         } u3;
 110         union {
 111                 struct {
 112                         u8 rdl;
 113                         u8 rdh;
 114                         u16 red2;
 115                 };
 116                 u32 redx;
 117         } u4;
 118
 119         u32 resi;
 120         u32 redi;
 121         u16 rds;
 122         u16 res;
 123         u32 reflags;
 124 }  __attribute__((packed));
 125
 126 static unsigned int hpwdt_nmi_sourcing;
 127 static unsigned int allow_kdump;
 128 static unsigned int priority;           /* hpwdt at end of die_notify list */
 129 static DEFINE_SPINLOCK(rom_lock);
 130 static void *cru_rom_addr;
 131 static struct cmn_registers cmn_regs;
 132
 133 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
 134                                                 unsigned long *pRomEntry);
 135
 136 #ifdef CONFIG_X86_32
 137 /* --32 Bit Bios------------------------------------------------------------ */
 138
 139 #define HPWDT_ARCH      32
 140
 141 asm(".text                          \n\t"
 142     ".align 4                       \n"
 143     "asminline_call:                \n\t"
 144     "pushl       %ebp               \n\t"
 145     "movl        %esp, %ebp         \n\t"
 146     "pusha                          \n\t"
 147     "pushf                          \n\t"
 148     "push        %es                \n\t"
 149     "push        %ds                \n\t"
 150     "pop         %es                \n\t"
 151     "movl        8(%ebp),%eax       \n\t"
 152     "movl        4(%eax),%ebx       \n\t"
 153     "movl        8(%eax),%ecx       \n\t"
 154     "movl        12(%eax),%edx      \n\t"
 155     "movl        16(%eax),%esi      \n\t"
 156     "movl        20(%eax),%edi      \n\t"
 157     "movl        (%eax),%eax        \n\t"
 158     "push        %cs                \n\t"
 159     "call        *12(%ebp)          \n\t"
 160     "pushf                          \n\t"
 161     "pushl       %eax               \n\t"
 162     "movl        8(%ebp),%eax       \n\t"
 163     "movl        %ebx,4(%eax)       \n\t"
 164     "movl        %ecx,8(%eax)       \n\t"
 165     "movl        %edx,12(%eax)      \n\t"
 166     "movl        %esi,16(%eax)      \n\t"
 167     "movl        %edi,20(%eax)      \n\t"
 168     "movw        %ds,24(%eax)       \n\t"
 169     "movw        %es,26(%eax)       \n\t"
 170     "popl        %ebx               \n\t"
 171     "movl        %ebx,(%eax)        \n\t"
 172     "popl        %ebx               \n\t"
 173     "movl        %ebx,28(%eax)      \n\t"
 174     "pop         %es                \n\t"
 175     "popf                           \n\t"
 176     "popa                           \n\t"
 177     "leave                          \n\t"
 178     "ret                            \n\t"
 179     ".previous");
 180
 181
 182 /*
 183  *      cru_detect
 184  *
 185  *      Routine Description:
 186  *      This function uses the 32-bit BIOS Service Directory record to
 187  *      search for a $CRU record.
 188  *
 189  *      Return Value:
 190  *      0        :  SUCCESS
 191  *      <0       :  FAILURE
 192  */
 193 static int __devinit cru_detect(unsigned long map_entry,
 194         unsigned long map_offset)
 195 {
 196         void *bios32_map;
 197         unsigned long *bios32_entrypoint;
 198         unsigned long cru_physical_address;
 199         unsigned long cru_length;
 200         unsigned long physical_bios_base = 0;
 201         unsigned long physical_bios_offset = 0;
 202         int retval = -ENODEV;
 203
 204         bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
 205
 206         if (bios32_map == NULL)
 207                 return -ENODEV;
 208
 209         bios32_entrypoint = bios32_map + map_offset;
 210
 211         cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 212
 213         asminline_call(&cmn_regs, bios32_entrypoint);
 214
 215         if (cmn_regs.u1.ral != 0) {
 216                 printk(KERN_WARNING
 217                         "hpwdt: Call succeeded but with an error: 0x%x\n",
 218                         cmn_regs.u1.ral);
 219         } else {
 220                 physical_bios_base = cmn_regs.u2.rebx;
 221                 physical_bios_offset = cmn_regs.u4.redx;
 222                 cru_length = cmn_regs.u3.recx;
 223                 cru_physical_address =
 224                         physical_bios_base + physical_bios_offset;
 225
 226                 /* If the values look OK, then map it in. */
 227                 if ((physical_bios_base + physical_bios_offset)) {
 228                         cru_rom_addr =
 229                                 ioremap(cru_physical_address, cru_length);
 230                         if (cru_rom_addr)
 231                                 retval = 0;
 232                 }
 233
 234                 printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
 235                         physical_bios_base);
 236                 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
 237                         physical_bios_offset);
 238                 printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
 239                         cru_length);
 240                 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: %p\n",
 241                         &cru_rom_addr);
 242         }
 243         iounmap(bios32_map);
 244         return retval;
 245 }
 246
 247 /*
 248  *      bios_checksum
 249  */
 250 static int __devinit bios_checksum(const char __iomem *ptr, int len)
 251 {
 252         char sum = 0;
 253         int i;
 254
 255         /*
 256          * calculate checksum of size bytes. This should add up
 257          * to zero if we have a valid header.
 258          */
 259         for (i = 0; i < len; i++)
 260                 sum += ptr[i];
 261
 262         return ((sum == 0) && (len > 0));
 263 }
 264
 265 /*
 266  *      bios32_present
 267  *
 268  *      Routine Description:
 269  *      This function finds the 32-bit BIOS Service Directory
 270  *
 271  *      Return Value:
 272  *      0        :  SUCCESS
 273  *      <0       :  FAILURE
 274  */
 275 static int __devinit bios32_present(const char __iomem *p)
 276 {
 277         struct bios32_service_dir *bios_32_ptr;
 278         int length;
 279         unsigned long map_entry, map_offset;
 280
 281         bios_32_ptr = (struct bios32_service_dir *) p;
 282
 283         /*
 284          * Search for signature by checking equal to the swizzled value
 285          * instead of calling another routine to perform a strcmp.
 286          */
 287         if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
 288                 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
 289                 if (bios_checksum(p, length)) {
 290                         /*
 291                          * According to the spec, we're looking for the
 292                          * first 4KB-aligned address below the entrypoint
 293                          * listed in the header. The Service Directory code
 294                          * is guaranteed to occupy no more than 2 4KB pages.
 295                          */
 296                         map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
 297                         map_offset = bios_32_ptr->entry_point - map_entry;
 298
 299                         return cru_detect(map_entry, map_offset);
 300                 }
 301         }
 302         return -ENODEV;
 303 }
 304
 305 static int __devinit detect_cru_service(void)
 306 {
 307         char __iomem *p, *q;
 308         int rc = -1;
 309
 310         /*
 311          * Search from 0x0f0000 through 0x0fffff, inclusive.
 312          */
 313         p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
 314         if (p == NULL)
 315                 return -ENOMEM;
 316
 317         for (q = p; q < p + ROM_SIZE; q += 16) {
 318                 rc = bios32_present(q);
 319                 if (!rc)
 320                         break;
 321         }
 322         iounmap(p);
 323         return rc;
 324 }
 325 /* ------------------------------------------------------------------------- */
 326 #endif /* CONFIG_X86_32 */
 327 #ifdef CONFIG_X86_64
 328 /* --64 Bit Bios------------------------------------------------------------ */
 329
 330 #define HPWDT_ARCH      64
 331
 332 asm(".text                      \n\t"
 333     ".align 4                   \n"
 334     "asminline_call:            \n\t"
 335     "pushq      %rbp            \n\t"
 336     "movq       %rsp, %rbp      \n\t"
 337     "pushq      %rax            \n\t"
 338     "pushq      %rbx            \n\t"
 339     "pushq      %rdx            \n\t"
 340     "pushq      %r12            \n\t"
 341     "pushq      %r9             \n\t"
 342     "movq       %rsi, %r12      \n\t"
 343     "movq       %rdi, %r9       \n\t"
 344     "movl       4(%r9),%ebx     \n\t"
 345     "movl       8(%r9),%ecx     \n\t"
 346     "movl       12(%r9),%edx    \n\t"
 347     "movl       16(%r9),%esi    \n\t"
 348     "movl       20(%r9),%edi    \n\t"
 349     "movl       (%r9),%eax      \n\t"
 350     "call       *%r12           \n\t"
 351     "pushfq                     \n\t"
 352     "popq        %r12           \n\t"
 353     "movl       %eax, (%r9)     \n\t"
 354     "movl       %ebx, 4(%r9)    \n\t"
 355     "movl       %ecx, 8(%r9)    \n\t"
 356     "movl       %edx, 12(%r9)   \n\t"
 357     "movl       %esi, 16(%r9)   \n\t"
 358     "movl       %edi, 20(%r9)   \n\t"
 359     "movq       %r12, %rax      \n\t"
 360     "movl       %eax, 28(%r9)   \n\t"
 361     "popq       %r9             \n\t"
 362     "popq       %r12            \n\t"
 363     "popq       %rdx            \n\t"
 364     "popq       %rbx            \n\t"
 365     "popq       %rax            \n\t"
 366     "leave                      \n\t"
 367     "ret                        \n\t"
 368     ".previous");
 369
 370 /*
 371  *      dmi_find_cru
 372  *
 373  *      Routine Description:
 374  *      This function checks whether or not a SMBIOS/DMI record is
 375  *      the 64bit CRU info or not
 376  */
 377 static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
 378 {
 379         struct smbios_cru64_info *smbios_cru64_ptr;
 380         unsigned long cru_physical_address;
 381
 382         if (dm->type == SMBIOS_CRU64_INFORMATION) {
 383                 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
 384                 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
 385                         cru_physical_address =
 386                                 smbios_cru64_ptr->physical_address +
 387                                 smbios_cru64_ptr->double_offset;
 388                         cru_rom_addr = ioremap(cru_physical_address,
 389                                 smbios_cru64_ptr->double_length);
 390                         set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
 391                                 smbios_cru64_ptr->double_length >> PAGE_SHIFT);
 392                 }
 393         }
 394 }
 395
 396 static int __devinit detect_cru_service(void)
 397 {
 398         cru_rom_addr = NULL;
 399
 400         dmi_walk(dmi_find_cru, NULL);
 401
 402         /* if cru_rom_addr has been set then we found a CRU service */
 403         return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
 404 }
 405 /* ------------------------------------------------------------------------- */
 406 #endif /* CONFIG_X86_64 */
 407
 408 /*
 409  *      Watchdog operations
 410  */
 411 static void hpwdt_start(void)
 412 {
 413         reload = (soft_margin * 1000) / 128;
 414         iowrite16(reload, hpwdt_timer_reg);
 415         iowrite16(0x85, hpwdt_timer_con);
 416 }
 417
 418 static void hpwdt_stop(void)
 419 {
 420         unsigned long data;
 421
 422         data = ioread16(hpwdt_timer_con);
 423         data &= 0xFE;
 424         iowrite16(data, hpwdt_timer_con);
 425 }
 426
 427 static void hpwdt_ping(void)
 428 {
 429         iowrite16(reload, hpwdt_timer_reg);
 430 }
 431
 432 static int hpwdt_change_timer(int new_margin)
 433 {
 434         /* Arbitrary, can't find the card's limits */
 435         if (new_margin < 5 || new_margin > 600) {
 436                 printk(KERN_WARNING
 437                         "hpwdt: New value passed in is invalid: %d seconds.\n",
 438                         new_margin);
 439                 return -EINVAL;
 440         }
 441
 442         soft_margin = new_margin;
 443         printk(KERN_DEBUG
 444                 "hpwdt: New timer passed in is %d seconds.\n",
 445                 new_margin);
 446         reload = (soft_margin * 1000) / 128;
 447
 448         return 0;
 449 }
 450
 451 /*
 452  *      NMI Handler
 453  */
 454 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
 455                                 void *data)
 456 {
 457         unsigned long rom_pl;
 458         static int die_nmi_called;
 459
 460         if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
 461                 return NOTIFY_OK;
 462
 463         if (hpwdt_nmi_sourcing) {
 464                 spin_lock_irqsave(&rom_lock, rom_pl);
 465                 if (!die_nmi_called)
 466                         asminline_call(&cmn_regs, cru_rom_addr);
 467                 die_nmi_called = 1;
 468                 spin_unlock_irqrestore(&rom_lock, rom_pl);
 469                 if (cmn_regs.u1.ral == 0) {
 470                         printk(KERN_WARNING "hpwdt: An NMI occurred, "
 471                                 "but unable to determine source.\n");
 472                 } else {
 473                         if (allow_kdump)
 474                                 hpwdt_stop();
 475                         panic("An NMI occurred, please see the Integrated "
 476                                 "Management Log for details.\n");
 477                 }
 478         }
 479         return NOTIFY_OK;
 480 }
 481
 482 /*
 483  *      /dev/watchdog handling
 484  */
 485 static int hpwdt_open(struct inode *inode, struct file *file)
 486 {
 487         /* /dev/watchdog can only be opened once */
 488         if (test_and_set_bit(0, &hpwdt_is_open))
 489                 return -EBUSY;
 490
 491         /* Start the watchdog */
 492         hpwdt_start();
 493         hpwdt_ping();
 494
 495         return nonseekable_open(inode, file);
 496 }
 497
 498 static int hpwdt_release(struct inode *inode, struct file *file)
 499 {
 500         /* Stop the watchdog */
 501         if (expect_release == 42) {
 502                 hpwdt_stop();
 503         } else {
 504                 printk(KERN_CRIT
 505                         "hpwdt: Unexpected close, not stopping watchdog!\n");
 506                 hpwdt_ping();
 507         }
 508
 509         expect_release = 0;
 510
 511         /* /dev/watchdog is being closed, make sure it can be re-opened */
 512         clear_bit(0, &hpwdt_is_open);
 513
 514         return 0;
 515 }
 516
 517 static ssize_t hpwdt_write(struct file *file, const char __user *data,
 518         size_t len, loff_t *ppos)
 519 {
 520         /* See if we got the magic character 'V' and reload the timer */
 521         if (len) {
 522                 if (!nowayout) {
 523                         size_t i;
 524
 525                         /* note: just in case someone wrote the magic character
 526                          * five months ago... */
 527                         expect_release = 0;
 528
 529                         /* scan to see whether or not we got the magic char. */
 530                         for (i = 0; i != len; i++) {
 531                                 char c;
 532                                 if (get_user(c, data + i))
 533                                         return -EFAULT;
 534                                 if (c == 'V')
 535                                         expect_release = 42;
 536                         }
 537                 }
 538
 539                 /* someone wrote to us, we should reload the timer */
 540                 hpwdt_ping();
 541         }
 542
 543         return len;
 544 }
 545
 546 static const struct watchdog_info ident = {
 547         .options = WDIOF_SETTIMEOUT |
 548                    WDIOF_KEEPALIVEPING |
 549                    WDIOF_MAGICCLOSE,
 550         .identity = "HP iLO2+ HW Watchdog Timer",
 551 };
 552
 553 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
 554         unsigned long arg)
 555 {
 556         void __user *argp = (void __user *)arg;
 557         int __user *p = argp;
 558         int new_margin;
 559         int ret = -ENOTTY;
 560
 561         switch (cmd) {
 562         case WDIOC_GETSUPPORT:
 563                 ret = 0;
 564                 if (copy_to_user(argp, &ident, sizeof(ident)))
 565                         ret = -EFAULT;
 566                 break;
 567
 568         case WDIOC_GETSTATUS:
 569         case WDIOC_GETBOOTSTATUS:
 570                 ret = put_user(0, p);
 571                 break;
 572
 573         case WDIOC_KEEPALIVE:
 574                 hpwdt_ping();
 575                 ret = 0;
 576                 break;
 577
 578         case WDIOC_SETTIMEOUT:
 579                 ret = get_user(new_margin, p);
 580                 if (ret)
 581                         break;
 582
 583                 ret = hpwdt_change_timer(new_margin);
 584                 if (ret)
 585                         break;
 586
 587                 hpwdt_ping();
 588                 /* Fall */
 589         case WDIOC_GETTIMEOUT:
 590                 ret = put_user(soft_margin, p);
 591                 break;
 592         }
 593         return ret;
 594 }
 595
 596 /*
 597  *      Kernel interfaces
 598  */
 599 static const struct file_operations hpwdt_fops = {
 600         .owner = THIS_MODULE,
 601         .llseek = no_llseek,
 602         .write = hpwdt_write,
 603         .unlocked_ioctl = hpwdt_ioctl,
 604         .open = hpwdt_open,
 605         .release = hpwdt_release,
 606 };
 607
 608 static struct miscdevice hpwdt_miscdev = {
 609         .minor = WATCHDOG_MINOR,
 610         .name = "watchdog",
 611         .fops = &hpwdt_fops,
 612 };
 613
 614 static struct notifier_block die_notifier = {
 615         .notifier_call = hpwdt_pretimeout,
 616         .priority = 0,
 617 };
 618
 619 /*
 620  *      Init & Exit
 621  */
 622
 623 #ifdef ARCH_HAS_NMI_WATCHDOG
 624 static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
 625 {
 626         /*
 627          * If nmi_watchdog is turned off then we can turn on
 628          * our nmi sourcing capability.
 629          */
 630         if (!nmi_watchdog_active())
 631                 hpwdt_nmi_sourcing = 1;
 632         else
 633                 dev_warn(&dev->dev, "NMI sourcing is disabled. To enable this "
 634                         "functionality you must reboot with nmi_watchdog=0 "
 635                         "and load the hpwdt driver with priority=1.\n");
 636 }
 637 #else
 638 static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
 639 {
 640         dev_warn(&dev->dev, "NMI sourcing is disabled. "
 641                 "Your kernel does not support a NMI Watchdog.\n");
 642 }
 643 #endif
 644
 645 static int __devinit hpwdt_init_one(struct pci_dev *dev,
 646                                         const struct pci_device_id *ent)
 647 {
 648         int retval;
 649
 650         /*
 651          * Check if we can do NMI sourcing or not
 652          */
 653         hpwdt_check_nmi_sourcing(dev);
 654
 655         /*
 656          * First let's find out if we are on an iLO2+ server. We will
 657          * not run on a legacy ASM box.
 658          * So we only support the G5 ProLiant servers and higher.
 659          */
 660         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
 661                 dev_warn(&dev->dev,
 662                         "This server does not have an iLO2+ ASIC.\n");
 663                 return -ENODEV;
 664         }
 665
 666         if (pci_enable_device(dev)) {
 667                 dev_warn(&dev->dev,
 668                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 669                         ent->vendor, ent->device);
 670                 return -ENODEV;
 671         }
 672
 673         pci_mem_addr = pci_iomap(dev, 1, 0x80);
 674         if (!pci_mem_addr) {
 675                 dev_warn(&dev->dev,
 676                         "Unable to detect the iLO2+ server memory.\n");
 677                 retval = -ENOMEM;
 678                 goto error_pci_iomap;
 679         }
 680         hpwdt_timer_reg = pci_mem_addr + 0x70;
 681         hpwdt_timer_con = pci_mem_addr + 0x72;
 682
 683         /* Make sure that we have a valid soft_margin */
 684         if (hpwdt_change_timer(soft_margin))
 685                 hpwdt_change_timer(DEFAULT_MARGIN);
 686
 687         /*
 688          * We need to map the ROM to get the CRU service.
 689          * For 32 bit Operating Systems we need to go through the 32 Bit
 690          * BIOS Service Directory
 691          * For 64 bit Operating Systems we get that service through SMBIOS.
 692          */
 693         retval = detect_cru_service();
 694         if (retval < 0) {
 695                 dev_warn(&dev->dev,
 696                         "Unable to detect the %d Bit CRU Service.\n",
 697                         HPWDT_ARCH);
 698                 goto error_get_cru;
 699         }
 700
 701         /*
 702          * We know this is the only CRU call we need to make so lets keep as
 703          * few instructions as possible once the NMI comes in.
 704          */
 705         cmn_regs.u1.rah = 0x0D;
 706         cmn_regs.u1.ral = 0x02;
 707
 708         /*
 709          * If the priority is set to 1, then we will be put first on the
 710          * die notify list to handle a critical NMI. The default is to
 711          * be last so other users of the NMI signal can function.
 712          */
 713         if (priority)
 714                 die_notifier.priority = 0x7FFFFFFF;
 715
 716         retval = register_die_notifier(&die_notifier);
 717         if (retval != 0) {
 718                 dev_warn(&dev->dev,
 719                         "Unable to register a die notifier (err=%d).\n",
 720                         retval);
 721                 goto error_die_notifier;
 722         }
 723
 724         retval = misc_register(&hpwdt_miscdev);
 725         if (retval < 0) {
 726                 dev_warn(&dev->dev,
 727                         "Unable to register miscdev on minor=%d (err=%d).\n",
 728                         WATCHDOG_MINOR, retval);
 729                 goto error_misc_register;
 730         }
 731
 732         printk(KERN_INFO
 733                 "hp Watchdog Timer Driver: %s"
 734                 ", timer margin: %d seconds (nowayout=%d)"
 735                 ", allow kernel dump: %s (default = 0/OFF)"
 736                 ", priority: %s (default = 0/LAST).\n",
 737                 HPWDT_VERSION, soft_margin, nowayout,
 738                 (allow_kdump == 0) ? "OFF" : "ON",
 739                 (priority == 0) ? "LAST" : "FIRST");
 740
 741         return 0;
 742
 743 error_misc_register:
 744         unregister_die_notifier(&die_notifier);
 745 error_die_notifier:
 746         if (cru_rom_addr)
 747                 iounmap(cru_rom_addr);
 748 error_get_cru:
 749         pci_iounmap(dev, pci_mem_addr);
 750 error_pci_iomap:
 751         pci_disable_device(dev);
 752         return retval;
 753 }
 754
 755 static void __devexit hpwdt_exit(struct pci_dev *dev)
 756 {
 757         if (!nowayout)
 758                 hpwdt_stop();
 759
 760         misc_deregister(&hpwdt_miscdev);
 761         unregister_die_notifier(&die_notifier);
 762
 763         if (cru_rom_addr)
 764                 iounmap(cru_rom_addr);
 765         pci_iounmap(dev, pci_mem_addr);
 766         pci_disable_device(dev);
 767 }
 768
 769 static struct pci_driver hpwdt_driver = {
 770         .name = "hpwdt",
 771         .id_table = hpwdt_devices,
 772         .probe = hpwdt_init_one,
 773         .remove = __devexit_p(hpwdt_exit),
 774 };
 775
 776 static void __exit hpwdt_cleanup(void)
 777 {
 778         pci_unregister_driver(&hpwdt_driver);
 779 }
 780
 781 static int __init hpwdt_init(void)
 782 {
 783         return pci_register_driver(&hpwdt_driver);
 784 }
 785
 786 MODULE_AUTHOR("Tom Mingarelli");
 787 MODULE_DESCRIPTION("hp watchdog driver");
 788 MODULE_LICENSE("GPL");
 789 MODULE_VERSION(HPWDT_VERSION);
 790 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 791
 792 module_param(soft_margin, int, 0);
 793 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 794
 795 module_param(nowayout, int, 0);
 796 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 797                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 798
 799 module_param(allow_kdump, int, 0);
 800 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
 801
 802 module_param(priority, int, 0);
 803 MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
 804                 " (default = 0/Last)\n");
 805
 806 module_init(hpwdt_init);
 807 module_exit(hpwdt_cleanup);