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