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