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