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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18#include <linux/device.h>
  19#include <linux/fs.h>
  20#include <linux/io.h>
  21#include <linux/bitops.h>
  22#include <linux/kernel.h>
  23#include <linux/miscdevice.h>
  24#include <linux/module.h>
  25#include <linux/moduleparam.h>
  26#include <linux/pci.h>
  27#include <linux/pci_ids.h>
  28#include <linux/types.h>
  29#include <linux/uaccess.h>
  30#include <linux/watchdog.h>
  31#ifdef CONFIG_HPWDT_NMI_DECODING
  32#include <linux/dmi.h>
  33#include <linux/spinlock.h>
  34#include <linux/nmi.h>
  35#include <linux/kdebug.h>
  36#include <linux/notifier.h>
  37#include <asm/cacheflush.h>
  38#endif /* CONFIG_HPWDT_NMI_DECODING */
  39#include <asm/nmi.h>
  40
  41#define HPWDT_VERSION                   "1.3.3"
  42#define SECS_TO_TICKS(secs)             ((secs) * 1000 / 128)
  43#define TICKS_TO_SECS(ticks)            ((ticks) * 128 / 1000)
  44#define HPWDT_MAX_TIMER                 TICKS_TO_SECS(65535)
  45#define DEFAULT_MARGIN                  30
  46
  47static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
  48static unsigned int reload;                     /* the computed soft_margin */
  49static bool nowayout = WATCHDOG_NOWAYOUT;
  50static char expect_release;
  51static unsigned long hpwdt_is_open;
  52
  53static void __iomem *pci_mem_addr;              /* the PCI-memory address */
  54static unsigned long __iomem *hpwdt_timer_reg;
  55static unsigned long __iomem *hpwdt_timer_con;
  56
  57static const struct pci_device_id hpwdt_devices[] = {
  58        { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },   /* iLO2 */
  59        { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },       /* iLO3 */
  60        {0},                    /* terminate list */
  61};
  62MODULE_DEVICE_TABLE(pci, hpwdt_devices);
  63
  64#ifdef CONFIG_HPWDT_NMI_DECODING
  65#define PCI_BIOS32_SD_VALUE             0x5F32335F      /* "_32_" */
  66#define CRU_BIOS_SIGNATURE_VALUE        0x55524324
  67#define PCI_BIOS32_PARAGRAPH_LEN        16
  68#define PCI_ROM_BASE1                   0x000F0000
  69#define ROM_SIZE                        0x10000
  70
  71struct bios32_service_dir {
  72        u32 signature;
  73        u32 entry_point;
  74        u8 revision;
  75        u8 length;
  76        u8 checksum;
  77        u8 reserved[5];
  78};
  79
  80/* type 212 */
  81struct smbios_cru64_info {
  82        u8 type;
  83        u8 byte_length;
  84        u16 handle;
  85        u32 signature;
  86        u64 physical_address;
  87        u32 double_length;
  88        u32 double_offset;
  89};
  90#define SMBIOS_CRU64_INFORMATION        212
  91
  92/* type 219 */
  93struct smbios_proliant_info {
  94        u8 type;
  95        u8 byte_length;
  96        u16 handle;
  97        u32 power_features;
  98        u32 omega_features;
  99        u32 reserved;
 100        u32 misc_features;
 101};
 102#define SMBIOS_ICRU_INFORMATION         219
 103
 104
 105struct cmn_registers {
 106        union {
 107                struct {
 108                        u8 ral;
 109                        u8 rah;
 110                        u16 rea2;
 111                };
 112                u32 reax;
 113        } u1;
 114        union {
 115                struct {
 116                        u8 rbl;
 117                        u8 rbh;
 118                        u8 reb2l;
 119                        u8 reb2h;
 120                };
 121                u32 rebx;
 122        } u2;
 123        union {
 124                struct {
 125                        u8 rcl;
 126                        u8 rch;
 127                        u16 rec2;
 128                };
 129                u32 recx;
 130        } u3;
 131        union {
 132                struct {
 133                        u8 rdl;
 134                        u8 rdh;
 135                        u16 red2;
 136                };
 137                u32 redx;
 138        } u4;
 139
 140        u32 resi;
 141        u32 redi;
 142        u16 rds;
 143        u16 res;
 144        u32 reflags;
 145}  __attribute__((packed));
 146
 147static unsigned int hpwdt_nmi_decoding;
 148static unsigned int allow_kdump = 1;
 149static unsigned int is_icru;
 150static unsigned int is_uefi;
 151static DEFINE_SPINLOCK(rom_lock);
 152static void *cru_rom_addr;
 153static struct cmn_registers cmn_regs;
 154
 155extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
 156                                                unsigned long *pRomEntry);
 157
 158#ifdef CONFIG_X86_32
 159/* --32 Bit Bios------------------------------------------------------------ */
 160
 161#define HPWDT_ARCH      32
 162
 163asm(".text                          \n\t"
 164    ".align 4                       \n\t"
 165    ".globl asminline_call          \n"
 166    "asminline_call:                \n\t"
 167    "pushl       %ebp               \n\t"
 168    "movl        %esp, %ebp         \n\t"
 169    "pusha                          \n\t"
 170    "pushf                          \n\t"
 171    "push        %es                \n\t"
 172    "push        %ds                \n\t"
 173    "pop         %es                \n\t"
 174    "movl        8(%ebp),%eax       \n\t"
 175    "movl        4(%eax),%ebx       \n\t"
 176    "movl        8(%eax),%ecx       \n\t"
 177    "movl        12(%eax),%edx      \n\t"
 178    "movl        16(%eax),%esi      \n\t"
 179    "movl        20(%eax),%edi      \n\t"
 180    "movl        (%eax),%eax        \n\t"
 181    "push        %cs                \n\t"
 182    "call        *12(%ebp)          \n\t"
 183    "pushf                          \n\t"
 184    "pushl       %eax               \n\t"
 185    "movl        8(%ebp),%eax       \n\t"
 186    "movl        %ebx,4(%eax)       \n\t"
 187    "movl        %ecx,8(%eax)       \n\t"
 188    "movl        %edx,12(%eax)      \n\t"
 189    "movl        %esi,16(%eax)      \n\t"
 190    "movl        %edi,20(%eax)      \n\t"
 191    "movw        %ds,24(%eax)       \n\t"
 192    "movw        %es,26(%eax)       \n\t"
 193    "popl        %ebx               \n\t"
 194    "movl        %ebx,(%eax)        \n\t"
 195    "popl        %ebx               \n\t"
 196    "movl        %ebx,28(%eax)      \n\t"
 197    "pop         %es                \n\t"
 198    "popf                           \n\t"
 199    "popa                           \n\t"
 200    "leave                          \n\t"
 201    "ret                            \n\t"
 202    ".previous");
 203
 204
 205/*
 206 *      cru_detect
 207 *
 208 *      Routine Description:
 209 *      This function uses the 32-bit BIOS Service Directory record to
 210 *      search for a $CRU record.
 211 *
 212 *      Return Value:
 213 *      0        :  SUCCESS
 214 *      <0       :  FAILURE
 215 */
 216static int cru_detect(unsigned long map_entry,
 217        unsigned long map_offset)
 218{
 219        void *bios32_map;
 220        unsigned long *bios32_entrypoint;
 221        unsigned long cru_physical_address;
 222        unsigned long cru_length;
 223        unsigned long physical_bios_base = 0;
 224        unsigned long physical_bios_offset = 0;
 225        int retval = -ENODEV;
 226
 227        bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
 228
 229        if (bios32_map == NULL)
 230                return -ENODEV;
 231
 232        bios32_entrypoint = bios32_map + map_offset;
 233
 234        cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 235
 236        set_memory_x((unsigned long)bios32_map, 2);
 237        asminline_call(&cmn_regs, bios32_entrypoint);
 238
 239        if (cmn_regs.u1.ral != 0) {
 240                pr_warn("Call succeeded but with an error: 0x%x\n",
 241                        cmn_regs.u1.ral);
 242        } else {
 243                physical_bios_base = cmn_regs.u2.rebx;
 244                physical_bios_offset = cmn_regs.u4.redx;
 245                cru_length = cmn_regs.u3.recx;
 246                cru_physical_address =
 247                        physical_bios_base + physical_bios_offset;
 248
 249                /* If the values look OK, then map it in. */
 250                if ((physical_bios_base + physical_bios_offset)) {
 251                        cru_rom_addr =
 252                                ioremap(cru_physical_address, cru_length);
 253                        if (cru_rom_addr) {
 254                                set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
 255                                        (cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
 256                                retval = 0;
 257                        }
 258                }
 259
 260                pr_debug("CRU Base Address:   0x%lx\n", physical_bios_base);
 261                pr_debug("CRU Offset Address: 0x%lx\n", physical_bios_offset);
 262                pr_debug("CRU Length:         0x%lx\n", cru_length);
 263                pr_debug("CRU Mapped Address: %p\n", &cru_rom_addr);
 264        }
 265        iounmap(bios32_map);
 266        return retval;
 267}
 268
 269/*
 270 *      bios_checksum
 271 */
 272static int bios_checksum(const char __iomem *ptr, int len)
 273{
 274        char sum = 0;
 275        int i;
 276
 277        /*
 278         * calculate checksum of size bytes. This should add up
 279         * to zero if we have a valid header.
 280         */
 281        for (i = 0; i < len; i++)
 282                sum += ptr[i];
 283
 284        return ((sum == 0) && (len > 0));
 285}
 286
 287/*
 288 *      bios32_present
 289 *
 290 *      Routine Description:
 291 *      This function finds the 32-bit BIOS Service Directory
 292 *
 293 *      Return Value:
 294 *      0        :  SUCCESS
 295 *      <0       :  FAILURE
 296 */
 297static int bios32_present(const char __iomem *p)
 298{
 299        struct bios32_service_dir *bios_32_ptr;
 300        int length;
 301        unsigned long map_entry, map_offset;
 302
 303        bios_32_ptr = (struct bios32_service_dir *) p;
 304
 305        /*
 306         * Search for signature by checking equal to the swizzled value
 307         * instead of calling another routine to perform a strcmp.
 308         */
 309        if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
 310                length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
 311                if (bios_checksum(p, length)) {
 312                        /*
 313                         * According to the spec, we're looking for the
 314                         * first 4KB-aligned address below the entrypoint
 315                         * listed in the header. The Service Directory code
 316                         * is guaranteed to occupy no more than 2 4KB pages.
 317                         */
 318                        map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
 319                        map_offset = bios_32_ptr->entry_point - map_entry;
 320
 321                        return cru_detect(map_entry, map_offset);
 322                }
 323        }
 324        return -ENODEV;
 325}
 326
 327static int detect_cru_service(void)
 328{
 329        char __iomem *p, *q;
 330        int rc = -1;
 331
 332        /*
 333         * Search from 0x0f0000 through 0x0fffff, inclusive.
 334         */
 335        p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
 336        if (p == NULL)
 337                return -ENOMEM;
 338
 339        for (q = p; q < p + ROM_SIZE; q += 16) {
 340                rc = bios32_present(q);
 341                if (!rc)
 342                        break;
 343        }
 344        iounmap(p);
 345        return rc;
 346}
 347/* ------------------------------------------------------------------------- */
 348#endif /* CONFIG_X86_32 */
 349#ifdef CONFIG_X86_64
 350/* --64 Bit Bios------------------------------------------------------------ */
 351
 352#define HPWDT_ARCH      64
 353
 354asm(".text                      \n\t"
 355    ".align 4                   \n\t"
 356    ".globl asminline_call      \n"
 357    "asminline_call:            \n\t"
 358    "pushq      %rbp            \n\t"
 359    "movq       %rsp, %rbp      \n\t"
 360    "pushq      %rax            \n\t"
 361    "pushq      %rbx            \n\t"
 362    "pushq      %rdx            \n\t"
 363    "pushq      %r12            \n\t"
 364    "pushq      %r9             \n\t"
 365    "movq       %rsi, %r12      \n\t"
 366    "movq       %rdi, %r9       \n\t"
 367    "movl       4(%r9),%ebx     \n\t"
 368    "movl       8(%r9),%ecx     \n\t"
 369    "movl       12(%r9),%edx    \n\t"
 370    "movl       16(%r9),%esi    \n\t"
 371    "movl       20(%r9),%edi    \n\t"
 372    "movl       (%r9),%eax      \n\t"
 373    "call       *%r12           \n\t"
 374    "pushfq                     \n\t"
 375    "popq        %r12           \n\t"
 376    "movl       %eax, (%r9)     \n\t"
 377    "movl       %ebx, 4(%r9)    \n\t"
 378    "movl       %ecx, 8(%r9)    \n\t"
 379    "movl       %edx, 12(%r9)   \n\t"
 380    "movl       %esi, 16(%r9)   \n\t"
 381    "movl       %edi, 20(%r9)   \n\t"
 382    "movq       %r12, %rax      \n\t"
 383    "movl       %eax, 28(%r9)   \n\t"
 384    "popq       %r9             \n\t"
 385    "popq       %r12            \n\t"
 386    "popq       %rdx            \n\t"
 387    "popq       %rbx            \n\t"
 388    "popq       %rax            \n\t"
 389    "leave                      \n\t"
 390    "ret                        \n\t"
 391    ".previous");
 392
 393/*
 394 *      dmi_find_cru
 395 *
 396 *      Routine Description:
 397 *      This function checks whether or not a SMBIOS/DMI record is
 398 *      the 64bit CRU info or not
 399 */
 400static void dmi_find_cru(const struct dmi_header *dm, void *dummy)
 401{
 402        struct smbios_cru64_info *smbios_cru64_ptr;
 403        unsigned long cru_physical_address;
 404
 405        if (dm->type == SMBIOS_CRU64_INFORMATION) {
 406                smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
 407                if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
 408                        cru_physical_address =
 409                                smbios_cru64_ptr->physical_address +
 410                                smbios_cru64_ptr->double_offset;
 411                        cru_rom_addr = ioremap(cru_physical_address,
 412                                smbios_cru64_ptr->double_length);
 413                        set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
 414                                smbios_cru64_ptr->double_length >> PAGE_SHIFT);
 415                }
 416        }
 417}
 418
 419static int detect_cru_service(void)
 420{
 421        cru_rom_addr = NULL;
 422
 423        dmi_walk(dmi_find_cru, NULL);
 424
 425        /* if cru_rom_addr has been set then we found a CRU service */
 426        return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
 427}
 428/* ------------------------------------------------------------------------- */
 429#endif /* CONFIG_X86_64 */
 430#endif /* CONFIG_HPWDT_NMI_DECODING */
 431
 432/*
 433 *      Watchdog operations
 434 */
 435static void hpwdt_start(void)
 436{
 437        reload = SECS_TO_TICKS(soft_margin);
 438        iowrite16(reload, hpwdt_timer_reg);
 439        iowrite8(0x85, hpwdt_timer_con);
 440}
 441
 442static void hpwdt_stop(void)
 443{
 444        unsigned long data;
 445
 446        data = ioread8(hpwdt_timer_con);
 447        data &= 0xFE;
 448        iowrite8(data, hpwdt_timer_con);
 449}
 450
 451static void hpwdt_ping(void)
 452{
 453        iowrite16(reload, hpwdt_timer_reg);
 454}
 455
 456static int hpwdt_change_timer(int new_margin)
 457{
 458        if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
 459                pr_warn("New value passed in is invalid: %d seconds\n",
 460                        new_margin);
 461                return -EINVAL;
 462        }
 463
 464        soft_margin = new_margin;
 465        pr_debug("New timer passed in is %d seconds\n", new_margin);
 466        reload = SECS_TO_TICKS(soft_margin);
 467
 468        return 0;
 469}
 470
 471static int hpwdt_time_left(void)
 472{
 473        return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
 474}
 475
 476#ifdef CONFIG_HPWDT_NMI_DECODING
 477/*
 478 *      NMI Handler
 479 */
 480static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
 481{
 482        unsigned long rom_pl;
 483        static int die_nmi_called;
 484
 485        if (!hpwdt_nmi_decoding)
 486                goto out;
 487
 488        spin_lock_irqsave(&rom_lock, rom_pl);
 489        if (!die_nmi_called && !is_icru && !is_uefi)
 490                asminline_call(&cmn_regs, cru_rom_addr);
 491        die_nmi_called = 1;
 492        spin_unlock_irqrestore(&rom_lock, rom_pl);
 493
 494        if (allow_kdump)
 495                hpwdt_stop();
 496
 497        if (!is_icru && !is_uefi) {
 498                if (cmn_regs.u1.ral == 0) {
 499                        panic("An NMI occurred, "
 500                                "but unable to determine source.\n");
 501                }
 502        }
 503        panic("An NMI occurred. Depending on your system the reason "
 504                "for the NMI is logged in any one of the following "
 505                "resources:\n"
 506                "1. Integrated Management Log (IML)\n"
 507                "2. OA Syslog\n"
 508                "3. OA Forward Progress Log\n"
 509                "4. iLO Event Log");
 510
 511out:
 512        return NMI_DONE;
 513}
 514#endif /* CONFIG_HPWDT_NMI_DECODING */
 515
 516/*
 517 *      /dev/watchdog handling
 518 */
 519static int hpwdt_open(struct inode *inode, struct file *file)
 520{
 521        /* /dev/watchdog can only be opened once */
 522        if (test_and_set_bit(0, &hpwdt_is_open))
 523                return -EBUSY;
 524
 525        /* Start the watchdog */
 526        hpwdt_start();
 527        hpwdt_ping();
 528
 529        return nonseekable_open(inode, file);
 530}
 531
 532static int hpwdt_release(struct inode *inode, struct file *file)
 533{
 534        /* Stop the watchdog */
 535        if (expect_release == 42) {
 536                hpwdt_stop();
 537        } else {
 538                pr_crit("Unexpected close, not stopping watchdog!\n");
 539                hpwdt_ping();
 540        }
 541
 542        expect_release = 0;
 543
 544        /* /dev/watchdog is being closed, make sure it can be re-opened */
 545        clear_bit(0, &hpwdt_is_open);
 546
 547        return 0;
 548}
 549
 550static ssize_t hpwdt_write(struct file *file, const char __user *data,
 551        size_t len, loff_t *ppos)
 552{
 553        /* See if we got the magic character 'V' and reload the timer */
 554        if (len) {
 555                if (!nowayout) {
 556                        size_t i;
 557
 558                        /* note: just in case someone wrote the magic character
 559                         * five months ago... */
 560                        expect_release = 0;
 561
 562                        /* scan to see whether or not we got the magic char. */
 563                        for (i = 0; i != len; i++) {
 564                                char c;
 565                                if (get_user(c, data + i))
 566                                        return -EFAULT;
 567                                if (c == 'V')
 568                                        expect_release = 42;
 569                        }
 570                }
 571
 572                /* someone wrote to us, we should reload the timer */
 573                hpwdt_ping();
 574        }
 575
 576        return len;
 577}
 578
 579static const struct watchdog_info ident = {
 580        .options = WDIOF_SETTIMEOUT |
 581                   WDIOF_KEEPALIVEPING |
 582                   WDIOF_MAGICCLOSE,
 583        .identity = "HP iLO2+ HW Watchdog Timer",
 584};
 585
 586static long hpwdt_ioctl(struct file *file, unsigned int cmd,
 587        unsigned long arg)
 588{
 589        void __user *argp = (void __user *)arg;
 590        int __user *p = argp;
 591        int new_margin;
 592        int ret = -ENOTTY;
 593
 594        switch (cmd) {
 595        case WDIOC_GETSUPPORT:
 596                ret = 0;
 597                if (copy_to_user(argp, &ident, sizeof(ident)))
 598                        ret = -EFAULT;
 599                break;
 600
 601        case WDIOC_GETSTATUS:
 602        case WDIOC_GETBOOTSTATUS:
 603                ret = put_user(0, p);
 604                break;
 605
 606        case WDIOC_KEEPALIVE:
 607                hpwdt_ping();
 608                ret = 0;
 609                break;
 610
 611        case WDIOC_SETTIMEOUT:
 612                ret = get_user(new_margin, p);
 613                if (ret)
 614                        break;
 615
 616                ret = hpwdt_change_timer(new_margin);
 617                if (ret)
 618                        break;
 619
 620                hpwdt_ping();
 621                /* Fall */
 622        case WDIOC_GETTIMEOUT:
 623                ret = put_user(soft_margin, p);
 624                break;
 625
 626        case WDIOC_GETTIMELEFT:
 627                ret = put_user(hpwdt_time_left(), p);
 628                break;
 629        }
 630        return ret;
 631}
 632
 633/*
 634 *      Kernel interfaces
 635 */
 636static const struct file_operations hpwdt_fops = {
 637        .owner = THIS_MODULE,
 638        .llseek = no_llseek,
 639        .write = hpwdt_write,
 640        .unlocked_ioctl = hpwdt_ioctl,
 641        .open = hpwdt_open,
 642        .release = hpwdt_release,
 643};
 644
 645static struct miscdevice hpwdt_miscdev = {
 646        .minor = WATCHDOG_MINOR,
 647        .name = "watchdog",
 648        .fops = &hpwdt_fops,
 649};
 650
 651/*
 652 *      Init & Exit
 653 */
 654
 655#ifdef CONFIG_HPWDT_NMI_DECODING
 656#ifdef CONFIG_X86_LOCAL_APIC
 657static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
 658{
 659        /*
 660         * If nmi_watchdog is turned off then we can turn on
 661         * our nmi decoding capability.
 662         */
 663        hpwdt_nmi_decoding = 1;
 664}
 665#else
 666static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
 667{
 668        dev_warn(&dev->dev, "NMI decoding is disabled. "
 669                "Your kernel does not support a NMI Watchdog.\n");
 670}
 671#endif /* CONFIG_X86_LOCAL_APIC */
 672
 673/*
 674 *      dmi_find_icru
 675 *
 676 *      Routine Description:
 677 *      This function checks whether or not we are on an iCRU-based server.
 678 *      This check is independent of architecture and needs to be made for
 679 *      any ProLiant system.
 680 */
 681static void dmi_find_icru(const struct dmi_header *dm, void *dummy)
 682{
 683        struct smbios_proliant_info *smbios_proliant_ptr;
 684
 685        if (dm->type == SMBIOS_ICRU_INFORMATION) {
 686                smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
 687                if (smbios_proliant_ptr->misc_features & 0x01)
 688                        is_icru = 1;
 689                if (smbios_proliant_ptr->misc_features & 0x408)
 690                        is_uefi = 1;
 691        }
 692}
 693
 694static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 695{
 696        int retval;
 697
 698        /*
 699         * On typical CRU-based systems we need to map that service in
 700         * the BIOS. For 32 bit Operating Systems we need to go through
 701         * the 32 Bit BIOS Service Directory. For 64 bit Operating
 702         * Systems we get that service through SMBIOS.
 703         *
 704         * On systems that support the new iCRU service all we need to
 705         * do is call dmi_walk to get the supported flag value and skip
 706         * the old cru detect code.
 707         */
 708        dmi_walk(dmi_find_icru, NULL);
 709        if (!is_icru && !is_uefi) {
 710
 711                /*
 712                * We need to map the ROM to get the CRU service.
 713                * For 32 bit Operating Systems we need to go through the 32 Bit
 714                * BIOS Service Directory
 715                * For 64 bit Operating Systems we get that service through SMBIOS.
 716                */
 717                retval = detect_cru_service();
 718                if (retval < 0) {
 719                        dev_warn(&dev->dev,
 720                                "Unable to detect the %d Bit CRU Service.\n",
 721                                HPWDT_ARCH);
 722                        return retval;
 723                }
 724
 725                /*
 726                * We know this is the only CRU call we need to make so lets keep as
 727                * few instructions as possible once the NMI comes in.
 728                */
 729                cmn_regs.u1.rah = 0x0D;
 730                cmn_regs.u1.ral = 0x02;
 731        }
 732
 733        /*
 734         * Only one function can register for NMI_UNKNOWN
 735         */
 736        retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
 737        if (retval)
 738                goto error;
 739        retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
 740        if (retval)
 741                goto error1;
 742        retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
 743        if (retval)
 744                goto error2;
 745
 746        dev_info(&dev->dev,
 747                        "HP Watchdog Timer Driver: NMI decoding initialized"
 748                        ", allow kernel dump: %s (default = 0/OFF)\n",
 749                        (allow_kdump == 0) ? "OFF" : "ON");
 750        return 0;
 751
 752error2:
 753        unregister_nmi_handler(NMI_SERR, "hpwdt");
 754error1:
 755        unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
 756error:
 757        dev_warn(&dev->dev,
 758                "Unable to register a die notifier (err=%d).\n",
 759                retval);
 760        if (cru_rom_addr)
 761                iounmap(cru_rom_addr);
 762        return retval;
 763}
 764
 765static void hpwdt_exit_nmi_decoding(void)
 766{
 767        unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
 768        unregister_nmi_handler(NMI_SERR, "hpwdt");
 769        unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
 770        if (cru_rom_addr)
 771                iounmap(cru_rom_addr);
 772}
 773#else /* !CONFIG_HPWDT_NMI_DECODING */
 774static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
 775{
 776}
 777
 778static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 779{
 780        return 0;
 781}
 782
 783static void hpwdt_exit_nmi_decoding(void)
 784{
 785}
 786#endif /* CONFIG_HPWDT_NMI_DECODING */
 787
 788static int hpwdt_init_one(struct pci_dev *dev,
 789                                        const struct pci_device_id *ent)
 790{
 791        int retval;
 792
 793        /*
 794         * Check if we can do NMI decoding or not
 795         */
 796        hpwdt_check_nmi_decoding(dev);
 797
 798        /*
 799         * First let's find out if we are on an iLO2+ server. We will
 800         * not run on a legacy ASM box.
 801         * So we only support the G5 ProLiant servers and higher.
 802         */
 803        if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
 804                dev_warn(&dev->dev,
 805                        "This server does not have an iLO2+ ASIC.\n");
 806                return -ENODEV;
 807        }
 808
 809        /*
 810         * Ignore all auxilary iLO devices with the following PCI ID
 811         */
 812        if (dev->subsystem_device == 0x1979)
 813                return -ENODEV;
 814
 815        if (pci_enable_device(dev)) {
 816                dev_warn(&dev->dev,
 817                        "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 818                        ent->vendor, ent->device);
 819                return -ENODEV;
 820        }
 821
 822        pci_mem_addr = pci_iomap(dev, 1, 0x80);
 823        if (!pci_mem_addr) {
 824                dev_warn(&dev->dev,
 825                        "Unable to detect the iLO2+ server memory.\n");
 826                retval = -ENOMEM;
 827                goto error_pci_iomap;
 828        }
 829        hpwdt_timer_reg = pci_mem_addr + 0x70;
 830        hpwdt_timer_con = pci_mem_addr + 0x72;
 831
 832        /* Make sure that timer is disabled until /dev/watchdog is opened */
 833        hpwdt_stop();
 834
 835        /* Make sure that we have a valid soft_margin */
 836        if (hpwdt_change_timer(soft_margin))
 837                hpwdt_change_timer(DEFAULT_MARGIN);
 838
 839        /* Initialize NMI Decoding functionality */
 840        retval = hpwdt_init_nmi_decoding(dev);
 841        if (retval != 0)
 842                goto error_init_nmi_decoding;
 843
 844        retval = misc_register(&hpwdt_miscdev);
 845        if (retval < 0) {
 846                dev_warn(&dev->dev,
 847                        "Unable to register miscdev on minor=%d (err=%d).\n",
 848                        WATCHDOG_MINOR, retval);
 849                goto error_misc_register;
 850        }
 851
 852        dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
 853                        ", timer margin: %d seconds (nowayout=%d).\n",
 854                        HPWDT_VERSION, soft_margin, nowayout);
 855        return 0;
 856
 857error_misc_register:
 858        hpwdt_exit_nmi_decoding();
 859error_init_nmi_decoding:
 860        pci_iounmap(dev, pci_mem_addr);
 861error_pci_iomap:
 862        pci_disable_device(dev);
 863        return retval;
 864}
 865
 866static void hpwdt_exit(struct pci_dev *dev)
 867{
 868        if (!nowayout)
 869                hpwdt_stop();
 870
 871        misc_deregister(&hpwdt_miscdev);
 872        hpwdt_exit_nmi_decoding();
 873        pci_iounmap(dev, pci_mem_addr);
 874        pci_disable_device(dev);
 875}
 876
 877static struct pci_driver hpwdt_driver = {
 878        .name = "hpwdt",
 879        .id_table = hpwdt_devices,
 880        .probe = hpwdt_init_one,
 881        .remove = hpwdt_exit,
 882};
 883
 884MODULE_AUTHOR("Tom Mingarelli");
 885MODULE_DESCRIPTION("hp watchdog driver");
 886MODULE_LICENSE("GPL");
 887MODULE_VERSION(HPWDT_VERSION);
 888
 889module_param(soft_margin, int, 0);
 890MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 891
 892module_param(nowayout, bool, 0);
 893MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 894                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 895
 896#ifdef CONFIG_HPWDT_NMI_DECODING
 897module_param(allow_kdump, int, 0);
 898MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
 899#endif /* !CONFIG_HPWDT_NMI_DECODING */
 900
 901module_pci_driver(hpwdt_driver);
 902