linux/drivers/watchdog/hpwdt.c
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   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#ifdef CONFIG_HPWDT_NMI_DECODING
  31#include <linux/dmi.h>
  32#include <linux/spinlock.h>
  33#include <linux/nmi.h>
  34#include <linux/kdebug.h>
  35#include <linux/notifier.h>
  36#include <asm/cacheflush.h>
  37#endif /* CONFIG_HPWDT_NMI_DECODING */
  38
  39#define HPWDT_VERSION                   "1.2.0"
  40#define SECS_TO_TICKS(secs)             ((secs) * 1000 / 128)
  41#define TICKS_TO_SECS(ticks)            ((ticks) * 128 / 1000)
  42#define HPWDT_MAX_TIMER                 TICKS_TO_SECS(65535)
  43#define DEFAULT_MARGIN                  30
  44
  45static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
  46static unsigned int reload;                     /* the computed soft_margin */
  47static int nowayout = WATCHDOG_NOWAYOUT;
  48static char expect_release;
  49static unsigned long hpwdt_is_open;
  50
  51static void __iomem *pci_mem_addr;              /* the PCI-memory address */
  52static unsigned long __iomem *hpwdt_timer_reg;
  53static unsigned long __iomem *hpwdt_timer_con;
  54
  55static struct pci_device_id hpwdt_devices[] = {
  56        { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },   /* iLO2 */
  57        { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },       /* iLO3 */
  58        {0},                    /* terminate list */
  59};
  60MODULE_DEVICE_TABLE(pci, hpwdt_devices);
  61
  62#ifdef CONFIG_HPWDT_NMI_DECODING
  63#define PCI_BIOS32_SD_VALUE             0x5F32335F      /* "_32_" */
  64#define CRU_BIOS_SIGNATURE_VALUE        0x55524324
  65#define PCI_BIOS32_PARAGRAPH_LEN        16
  66#define PCI_ROM_BASE1                   0x000F0000
  67#define ROM_SIZE                        0x10000
  68
  69struct bios32_service_dir {
  70        u32 signature;
  71        u32 entry_point;
  72        u8 revision;
  73        u8 length;
  74        u8 checksum;
  75        u8 reserved[5];
  76};
  77
  78/* type 212 */
  79struct smbios_cru64_info {
  80        u8 type;
  81        u8 byte_length;
  82        u16 handle;
  83        u32 signature;
  84        u64 physical_address;
  85        u32 double_length;
  86        u32 double_offset;
  87};
  88#define SMBIOS_CRU64_INFORMATION        212
  89
  90struct cmn_registers {
  91        union {
  92                struct {
  93                        u8 ral;
  94                        u8 rah;
  95                        u16 rea2;
  96                };
  97                u32 reax;
  98        } u1;
  99        union {
 100                struct {
 101                        u8 rbl;
 102                        u8 rbh;
 103                        u8 reb2l;
 104                        u8 reb2h;
 105                };
 106                u32 rebx;
 107        } u2;
 108        union {
 109                struct {
 110                        u8 rcl;
 111                        u8 rch;
 112                        u16 rec2;
 113                };
 114                u32 recx;
 115        } u3;
 116        union {
 117                struct {
 118                        u8 rdl;
 119                        u8 rdh;
 120                        u16 red2;
 121                };
 122                u32 redx;
 123        } u4;
 124
 125        u32 resi;
 126        u32 redi;
 127        u16 rds;
 128        u16 res;
 129        u32 reflags;
 130}  __attribute__((packed));
 131
 132static unsigned int hpwdt_nmi_decoding;
 133static unsigned int allow_kdump;
 134static unsigned int priority;           /* hpwdt at end of die_notify list */
 135static DEFINE_SPINLOCK(rom_lock);
 136static void *cru_rom_addr;
 137static struct cmn_registers cmn_regs;
 138
 139extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
 140                                                unsigned long *pRomEntry);
 141
 142#ifdef CONFIG_X86_32
 143/* --32 Bit Bios------------------------------------------------------------ */
 144
 145#define HPWDT_ARCH      32
 146
 147asm(".text                          \n\t"
 148    ".align 4                       \n"
 149    "asminline_call:                \n\t"
 150    "pushl       %ebp               \n\t"
 151    "movl        %esp, %ebp         \n\t"
 152    "pusha                          \n\t"
 153    "pushf                          \n\t"
 154    "push        %es                \n\t"
 155    "push        %ds                \n\t"
 156    "pop         %es                \n\t"
 157    "movl        8(%ebp),%eax       \n\t"
 158    "movl        4(%eax),%ebx       \n\t"
 159    "movl        8(%eax),%ecx       \n\t"
 160    "movl        12(%eax),%edx      \n\t"
 161    "movl        16(%eax),%esi      \n\t"
 162    "movl        20(%eax),%edi      \n\t"
 163    "movl        (%eax),%eax        \n\t"
 164    "push        %cs                \n\t"
 165    "call        *12(%ebp)          \n\t"
 166    "pushf                          \n\t"
 167    "pushl       %eax               \n\t"
 168    "movl        8(%ebp),%eax       \n\t"
 169    "movl        %ebx,4(%eax)       \n\t"
 170    "movl        %ecx,8(%eax)       \n\t"
 171    "movl        %edx,12(%eax)      \n\t"
 172    "movl        %esi,16(%eax)      \n\t"
 173    "movl        %edi,20(%eax)      \n\t"
 174    "movw        %ds,24(%eax)       \n\t"
 175    "movw        %es,26(%eax)       \n\t"
 176    "popl        %ebx               \n\t"
 177    "movl        %ebx,(%eax)        \n\t"
 178    "popl        %ebx               \n\t"
 179    "movl        %ebx,28(%eax)      \n\t"
 180    "pop         %es                \n\t"
 181    "popf                           \n\t"
 182    "popa                           \n\t"
 183    "leave                          \n\t"
 184    "ret                            \n\t"
 185    ".previous");
 186
 187
 188/*
 189 *      cru_detect
 190 *
 191 *      Routine Description:
 192 *      This function uses the 32-bit BIOS Service Directory record to
 193 *      search for a $CRU record.
 194 *
 195 *      Return Value:
 196 *      0        :  SUCCESS
 197 *      <0       :  FAILURE
 198 */
 199static int __devinit cru_detect(unsigned long map_entry,
 200        unsigned long map_offset)
 201{
 202        void *bios32_map;
 203        unsigned long *bios32_entrypoint;
 204        unsigned long cru_physical_address;
 205        unsigned long cru_length;
 206        unsigned long physical_bios_base = 0;
 207        unsigned long physical_bios_offset = 0;
 208        int retval = -ENODEV;
 209
 210        bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
 211
 212        if (bios32_map == NULL)
 213                return -ENODEV;
 214
 215        bios32_entrypoint = bios32_map + map_offset;
 216
 217        cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 218
 219        asminline_call(&cmn_regs, bios32_entrypoint);
 220
 221        if (cmn_regs.u1.ral != 0) {
 222                printk(KERN_WARNING
 223                        "hpwdt: Call succeeded but with an error: 0x%x\n",
 224                        cmn_regs.u1.ral);
 225        } else {
 226                physical_bios_base = cmn_regs.u2.rebx;
 227                physical_bios_offset = cmn_regs.u4.redx;
 228                cru_length = cmn_regs.u3.recx;
 229                cru_physical_address =
 230                        physical_bios_base + physical_bios_offset;
 231
 232                /* If the values look OK, then map it in. */
 233                if ((physical_bios_base + physical_bios_offset)) {
 234                        cru_rom_addr =
 235                                ioremap(cru_physical_address, cru_length);
 236                        if (cru_rom_addr)
 237                                retval = 0;
 238                }
 239
 240                printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
 241                        physical_bios_base);
 242                printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
 243                        physical_bios_offset);
 244                printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
 245                        cru_length);
 246                printk(KERN_DEBUG "hpwdt: CRU Mapped Address: %p\n",
 247                        &cru_rom_addr);
 248        }
 249        iounmap(bios32_map);
 250        return retval;
 251}
 252
 253/*
 254 *      bios_checksum
 255 */
 256static int __devinit bios_checksum(const char __iomem *ptr, int len)
 257{
 258        char sum = 0;
 259        int i;
 260
 261        /*
 262         * calculate checksum of size bytes. This should add up
 263         * to zero if we have a valid header.
 264         */
 265        for (i = 0; i < len; i++)
 266                sum += ptr[i];
 267
 268        return ((sum == 0) && (len > 0));
 269}
 270
 271/*
 272 *      bios32_present
 273 *
 274 *      Routine Description:
 275 *      This function finds the 32-bit BIOS Service Directory
 276 *
 277 *      Return Value:
 278 *      0        :  SUCCESS
 279 *      <0       :  FAILURE
 280 */
 281static int __devinit bios32_present(const char __iomem *p)
 282{
 283        struct bios32_service_dir *bios_32_ptr;
 284        int length;
 285        unsigned long map_entry, map_offset;
 286
 287        bios_32_ptr = (struct bios32_service_dir *) p;
 288
 289        /*
 290         * Search for signature by checking equal to the swizzled value
 291         * instead of calling another routine to perform a strcmp.
 292         */
 293        if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
 294                length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
 295                if (bios_checksum(p, length)) {
 296                        /*
 297                         * According to the spec, we're looking for the
 298                         * first 4KB-aligned address below the entrypoint
 299                         * listed in the header. The Service Directory code
 300                         * is guaranteed to occupy no more than 2 4KB pages.
 301                         */
 302                        map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
 303                        map_offset = bios_32_ptr->entry_point - map_entry;
 304
 305                        return cru_detect(map_entry, map_offset);
 306                }
 307        }
 308        return -ENODEV;
 309}
 310
 311static int __devinit detect_cru_service(void)
 312{
 313        char __iomem *p, *q;
 314        int rc = -1;
 315
 316        /*
 317         * Search from 0x0f0000 through 0x0fffff, inclusive.
 318         */
 319        p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
 320        if (p == NULL)
 321                return -ENOMEM;
 322
 323        for (q = p; q < p + ROM_SIZE; q += 16) {
 324                rc = bios32_present(q);
 325                if (!rc)
 326                        break;
 327        }
 328        iounmap(p);
 329        return rc;
 330}
 331/* ------------------------------------------------------------------------- */
 332#endif /* CONFIG_X86_32 */
 333#ifdef CONFIG_X86_64
 334/* --64 Bit Bios------------------------------------------------------------ */
 335
 336#define HPWDT_ARCH      64
 337
 338asm(".text                      \n\t"
 339    ".align 4                   \n"
 340    "asminline_call:            \n\t"
 341    "pushq      %rbp            \n\t"
 342    "movq       %rsp, %rbp      \n\t"
 343    "pushq      %rax            \n\t"
 344    "pushq      %rbx            \n\t"
 345    "pushq      %rdx            \n\t"
 346    "pushq      %r12            \n\t"
 347    "pushq      %r9             \n\t"
 348    "movq       %rsi, %r12      \n\t"
 349    "movq       %rdi, %r9       \n\t"
 350    "movl       4(%r9),%ebx     \n\t"
 351    "movl       8(%r9),%ecx     \n\t"
 352    "movl       12(%r9),%edx    \n\t"
 353    "movl       16(%r9),%esi    \n\t"
 354    "movl       20(%r9),%edi    \n\t"
 355    "movl       (%r9),%eax      \n\t"
 356    "call       *%r12           \n\t"
 357    "pushfq                     \n\t"
 358    "popq        %r12           \n\t"
 359    "movl       %eax, (%r9)     \n\t"
 360    "movl       %ebx, 4(%r9)    \n\t"
 361    "movl       %ecx, 8(%r9)    \n\t"
 362    "movl       %edx, 12(%r9)   \n\t"
 363    "movl       %esi, 16(%r9)   \n\t"
 364    "movl       %edi, 20(%r9)   \n\t"
 365    "movq       %r12, %rax      \n\t"
 366    "movl       %eax, 28(%r9)   \n\t"
 367    "popq       %r9             \n\t"
 368    "popq       %r12            \n\t"
 369    "popq       %rdx            \n\t"
 370    "popq       %rbx            \n\t"
 371    "popq       %rax            \n\t"
 372    "leave                      \n\t"
 373    "ret                        \n\t"
 374    ".previous");
 375
 376/*
 377 *      dmi_find_cru
 378 *
 379 *      Routine Description:
 380 *      This function checks whether or not a SMBIOS/DMI record is
 381 *      the 64bit CRU info or not
 382 */
 383static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
 384{
 385        struct smbios_cru64_info *smbios_cru64_ptr;
 386        unsigned long cru_physical_address;
 387
 388        if (dm->type == SMBIOS_CRU64_INFORMATION) {
 389                smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
 390                if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
 391                        cru_physical_address =
 392                                smbios_cru64_ptr->physical_address +
 393                                smbios_cru64_ptr->double_offset;
 394                        cru_rom_addr = ioremap(cru_physical_address,
 395                                smbios_cru64_ptr->double_length);
 396                        set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
 397                                smbios_cru64_ptr->double_length >> PAGE_SHIFT);
 398                }
 399        }
 400}
 401
 402static int __devinit detect_cru_service(void)
 403{
 404        cru_rom_addr = NULL;
 405
 406        dmi_walk(dmi_find_cru, NULL);
 407
 408        /* if cru_rom_addr has been set then we found a CRU service */
 409        return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
 410}
 411/* ------------------------------------------------------------------------- */
 412#endif /* CONFIG_X86_64 */
 413#endif /* CONFIG_HPWDT_NMI_DECODING */
 414
 415/*
 416 *      Watchdog operations
 417 */
 418static void hpwdt_start(void)
 419{
 420        reload = SECS_TO_TICKS(soft_margin);
 421        iowrite16(reload, hpwdt_timer_reg);
 422        iowrite16(0x85, hpwdt_timer_con);
 423}
 424
 425static void hpwdt_stop(void)
 426{
 427        unsigned long data;
 428
 429        data = ioread16(hpwdt_timer_con);
 430        data &= 0xFE;
 431        iowrite16(data, hpwdt_timer_con);
 432}
 433
 434static void hpwdt_ping(void)
 435{
 436        iowrite16(reload, hpwdt_timer_reg);
 437}
 438
 439static int hpwdt_change_timer(int new_margin)
 440{
 441        if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
 442                printk(KERN_WARNING
 443                        "hpwdt: New value passed in is invalid: %d seconds.\n",
 444                        new_margin);
 445                return -EINVAL;
 446        }
 447
 448        soft_margin = new_margin;
 449        printk(KERN_DEBUG
 450                "hpwdt: New timer passed in is %d seconds.\n",
 451                new_margin);
 452        reload = SECS_TO_TICKS(soft_margin);
 453
 454        return 0;
 455}
 456
 457static int hpwdt_time_left(void)
 458{
 459        return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
 460}
 461
 462#ifdef CONFIG_HPWDT_NMI_DECODING
 463/*
 464 *      NMI Handler
 465 */
 466static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
 467                                void *data)
 468{
 469        unsigned long rom_pl;
 470        static int die_nmi_called;
 471
 472        if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
 473                goto out;
 474
 475        if (!hpwdt_nmi_decoding)
 476                goto out;
 477
 478        spin_lock_irqsave(&rom_lock, rom_pl);
 479        if (!die_nmi_called)
 480                asminline_call(&cmn_regs, cru_rom_addr);
 481        die_nmi_called = 1;
 482        spin_unlock_irqrestore(&rom_lock, rom_pl);
 483        if (cmn_regs.u1.ral == 0) {
 484                printk(KERN_WARNING "hpwdt: An NMI occurred, "
 485                        "but unable to determine source.\n");
 486        } else {
 487                if (allow_kdump)
 488                        hpwdt_stop();
 489                panic("An NMI occurred, please see the Integrated "
 490                        "Management Log for details.\n");
 491        }
 492out:
 493        return NOTIFY_OK;
 494}
 495#endif /* CONFIG_HPWDT_NMI_DECODING */
 496
 497/*
 498 *      /dev/watchdog handling
 499 */
 500static int hpwdt_open(struct inode *inode, struct file *file)
 501{
 502        /* /dev/watchdog can only be opened once */
 503        if (test_and_set_bit(0, &hpwdt_is_open))
 504                return -EBUSY;
 505
 506        /* Start the watchdog */
 507        hpwdt_start();
 508        hpwdt_ping();
 509
 510        return nonseekable_open(inode, file);
 511}
 512
 513static int hpwdt_release(struct inode *inode, struct file *file)
 514{
 515        /* Stop the watchdog */
 516        if (expect_release == 42) {
 517                hpwdt_stop();
 518        } else {
 519                printk(KERN_CRIT
 520                        "hpwdt: Unexpected close, not stopping watchdog!\n");
 521                hpwdt_ping();
 522        }
 523
 524        expect_release = 0;
 525
 526        /* /dev/watchdog is being closed, make sure it can be re-opened */
 527        clear_bit(0, &hpwdt_is_open);
 528
 529        return 0;
 530}
 531
 532static ssize_t hpwdt_write(struct file *file, const char __user *data,
 533        size_t len, loff_t *ppos)
 534{
 535        /* See if we got the magic character 'V' and reload the timer */
 536        if (len) {
 537                if (!nowayout) {
 538                        size_t i;
 539
 540                        /* note: just in case someone wrote the magic character
 541                         * five months ago... */
 542                        expect_release = 0;
 543
 544                        /* scan to see whether or not we got the magic char. */
 545                        for (i = 0; i != len; i++) {
 546                                char c;
 547                                if (get_user(c, data + i))
 548                                        return -EFAULT;
 549                                if (c == 'V')
 550                                        expect_release = 42;
 551                        }
 552                }
 553
 554                /* someone wrote to us, we should reload the timer */
 555                hpwdt_ping();
 556        }
 557
 558        return len;
 559}
 560
 561static const struct watchdog_info ident = {
 562        .options = WDIOF_SETTIMEOUT |
 563                   WDIOF_KEEPALIVEPING |
 564                   WDIOF_MAGICCLOSE,
 565        .identity = "HP iLO2+ HW Watchdog Timer",
 566};
 567
 568static long hpwdt_ioctl(struct file *file, unsigned int cmd,
 569        unsigned long arg)
 570{
 571        void __user *argp = (void __user *)arg;
 572        int __user *p = argp;
 573        int new_margin;
 574        int ret = -ENOTTY;
 575
 576        switch (cmd) {
 577        case WDIOC_GETSUPPORT:
 578                ret = 0;
 579                if (copy_to_user(argp, &ident, sizeof(ident)))
 580                        ret = -EFAULT;
 581                break;
 582
 583        case WDIOC_GETSTATUS:
 584        case WDIOC_GETBOOTSTATUS:
 585                ret = put_user(0, p);
 586                break;
 587
 588        case WDIOC_KEEPALIVE:
 589                hpwdt_ping();
 590                ret = 0;
 591                break;
 592
 593        case WDIOC_SETTIMEOUT:
 594                ret = get_user(new_margin, p);
 595                if (ret)
 596                        break;
 597
 598                ret = hpwdt_change_timer(new_margin);
 599                if (ret)
 600                        break;
 601
 602                hpwdt_ping();
 603                /* Fall */
 604        case WDIOC_GETTIMEOUT:
 605                ret = put_user(soft_margin, p);
 606                break;
 607
 608        case WDIOC_GETTIMELEFT:
 609                ret = put_user(hpwdt_time_left(), p);
 610                break;
 611        }
 612        return ret;
 613}
 614
 615/*
 616 *      Kernel interfaces
 617 */
 618static const struct file_operations hpwdt_fops = {
 619        .owner = THIS_MODULE,
 620        .llseek = no_llseek,
 621        .write = hpwdt_write,
 622        .unlocked_ioctl = hpwdt_ioctl,
 623        .open = hpwdt_open,
 624        .release = hpwdt_release,
 625};
 626
 627static struct miscdevice hpwdt_miscdev = {
 628        .minor = WATCHDOG_MINOR,
 629        .name = "watchdog",
 630        .fops = &hpwdt_fops,
 631};
 632
 633#ifdef CONFIG_HPWDT_NMI_DECODING
 634static struct notifier_block die_notifier = {
 635        .notifier_call = hpwdt_pretimeout,
 636        .priority = 0,
 637};
 638#endif /* CONFIG_HPWDT_NMI_DECODING */
 639
 640/*
 641 *      Init & Exit
 642 */
 643
 644#ifdef CONFIG_HPWDT_NMI_DECODING
 645#ifdef ARCH_HAS_NMI_WATCHDOG
 646static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
 647{
 648        /*
 649         * If nmi_watchdog is turned off then we can turn on
 650         * our nmi decoding capability.
 651         */
 652        if (!nmi_watchdog_active())
 653                hpwdt_nmi_decoding = 1;
 654        else
 655                dev_warn(&dev->dev, "NMI decoding is disabled. To enable this "
 656                        "functionality you must reboot with nmi_watchdog=0 "
 657                        "and load the hpwdt driver with priority=1.\n");
 658}
 659#else
 660static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
 661{
 662        dev_warn(&dev->dev, "NMI decoding is disabled. "
 663                "Your kernel does not support a NMI Watchdog.\n");
 664}
 665#endif /* ARCH_HAS_NMI_WATCHDOG */
 666
 667static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
 668{
 669        int retval;
 670
 671        /*
 672         * We need to map the ROM to get the CRU service.
 673         * For 32 bit Operating Systems we need to go through the 32 Bit
 674         * BIOS Service Directory
 675         * For 64 bit Operating Systems we get that service through SMBIOS.
 676         */
 677        retval = detect_cru_service();
 678        if (retval < 0) {
 679                dev_warn(&dev->dev,
 680                        "Unable to detect the %d Bit CRU Service.\n",
 681                        HPWDT_ARCH);
 682                return retval;
 683        }
 684
 685        /*
 686         * We know this is the only CRU call we need to make so lets keep as
 687         * few instructions as possible once the NMI comes in.
 688         */
 689        cmn_regs.u1.rah = 0x0D;
 690        cmn_regs.u1.ral = 0x02;
 691
 692        /*
 693         * If the priority is set to 1, then we will be put first on the
 694         * die notify list to handle a critical NMI. The default is to
 695         * be last so other users of the NMI signal can function.
 696         */
 697        if (priority)
 698                die_notifier.priority = 0x7FFFFFFF;
 699
 700        retval = register_die_notifier(&die_notifier);
 701        if (retval != 0) {
 702                dev_warn(&dev->dev,
 703                        "Unable to register a die notifier (err=%d).\n",
 704                        retval);
 705                if (cru_rom_addr)
 706                        iounmap(cru_rom_addr);
 707        }
 708
 709        dev_info(&dev->dev,
 710                        "HP Watchdog Timer Driver: NMI decoding initialized"
 711                        ", allow kernel dump: %s (default = 0/OFF)"
 712                        ", priority: %s (default = 0/LAST).\n",
 713                        (allow_kdump == 0) ? "OFF" : "ON",
 714                        (priority == 0) ? "LAST" : "FIRST");
 715        return 0;
 716}
 717
 718static void __devexit hpwdt_exit_nmi_decoding(void)
 719{
 720        unregister_die_notifier(&die_notifier);
 721        if (cru_rom_addr)
 722                iounmap(cru_rom_addr);
 723}
 724#else /* !CONFIG_HPWDT_NMI_DECODING */
 725static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
 726{
 727}
 728
 729static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
 730{
 731        return 0;
 732}
 733
 734static void __devexit hpwdt_exit_nmi_decoding(void)
 735{
 736}
 737#endif /* CONFIG_HPWDT_NMI_DECODING */
 738
 739static int __devinit hpwdt_init_one(struct pci_dev *dev,
 740                                        const struct pci_device_id *ent)
 741{
 742        int retval;
 743
 744        /*
 745         * Check if we can do NMI decoding or not
 746         */
 747        hpwdt_check_nmi_decoding(dev);
 748
 749        /*
 750         * First let's find out if we are on an iLO2+ server. We will
 751         * not run on a legacy ASM box.
 752         * So we only support the G5 ProLiant servers and higher.
 753         */
 754        if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
 755                dev_warn(&dev->dev,
 756                        "This server does not have an iLO2+ ASIC.\n");
 757                return -ENODEV;
 758        }
 759
 760        if (pci_enable_device(dev)) {
 761                dev_warn(&dev->dev,
 762                        "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 763                        ent->vendor, ent->device);
 764                return -ENODEV;
 765        }
 766
 767        pci_mem_addr = pci_iomap(dev, 1, 0x80);
 768        if (!pci_mem_addr) {
 769                dev_warn(&dev->dev,
 770                        "Unable to detect the iLO2+ server memory.\n");
 771                retval = -ENOMEM;
 772                goto error_pci_iomap;
 773        }
 774        hpwdt_timer_reg = pci_mem_addr + 0x70;
 775        hpwdt_timer_con = pci_mem_addr + 0x72;
 776
 777        /* Make sure that we have a valid soft_margin */
 778        if (hpwdt_change_timer(soft_margin))
 779                hpwdt_change_timer(DEFAULT_MARGIN);
 780
 781        /* Initialize NMI Decoding functionality */
 782        retval = hpwdt_init_nmi_decoding(dev);
 783        if (retval != 0)
 784                goto error_init_nmi_decoding;
 785
 786        retval = misc_register(&hpwdt_miscdev);
 787        if (retval < 0) {
 788                dev_warn(&dev->dev,
 789                        "Unable to register miscdev on minor=%d (err=%d).\n",
 790                        WATCHDOG_MINOR, retval);
 791                goto error_misc_register;
 792        }
 793
 794        dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
 795                        ", timer margin: %d seconds (nowayout=%d).\n",
 796                        HPWDT_VERSION, soft_margin, nowayout);
 797        return 0;
 798
 799error_misc_register:
 800        hpwdt_exit_nmi_decoding();
 801error_init_nmi_decoding:
 802        pci_iounmap(dev, pci_mem_addr);
 803error_pci_iomap:
 804        pci_disable_device(dev);
 805        return retval;
 806}
 807
 808static void __devexit hpwdt_exit(struct pci_dev *dev)
 809{
 810        if (!nowayout)
 811                hpwdt_stop();
 812
 813        misc_deregister(&hpwdt_miscdev);
 814        hpwdt_exit_nmi_decoding();
 815        pci_iounmap(dev, pci_mem_addr);
 816        pci_disable_device(dev);
 817}
 818
 819static struct pci_driver hpwdt_driver = {
 820        .name = "hpwdt",
 821        .id_table = hpwdt_devices,
 822        .probe = hpwdt_init_one,
 823        .remove = __devexit_p(hpwdt_exit),
 824};
 825
 826static void __exit hpwdt_cleanup(void)
 827{
 828        pci_unregister_driver(&hpwdt_driver);
 829}
 830
 831static int __init hpwdt_init(void)
 832{
 833        return pci_register_driver(&hpwdt_driver);
 834}
 835
 836MODULE_AUTHOR("Tom Mingarelli");
 837MODULE_DESCRIPTION("hp watchdog driver");
 838MODULE_LICENSE("GPL");
 839MODULE_VERSION(HPWDT_VERSION);
 840MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 841
 842module_param(soft_margin, int, 0);
 843MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 844
 845module_param(nowayout, int, 0);
 846MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 847                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 848
 849#ifdef CONFIG_HPWDT_NMI_DECODING
 850module_param(allow_kdump, int, 0);
 851MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
 852
 853module_param(priority, int, 0);
 854MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
 855                " (default = 0/Last)\n");
 856#endif /* !CONFIG_HPWDT_NMI_DECODING */
 857
 858module_init(hpwdt_init);
 859module_exit(hpwdt_cleanup);
 860