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 #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
  45 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
  46 static unsigned int reload;                     /* the computed soft_margin */
  47 static int nowayout = WATCHDOG_NOWAYOUT;
  48 static char expect_release;
  49 static unsigned long hpwdt_is_open;
  50
  51 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
  52 static unsigned long __iomem *hpwdt_timer_reg;
  53 static unsigned long __iomem *hpwdt_timer_con;
  54
  55 static 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 };
  60 MODULE_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
  69 struct 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 */
  79 struct 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
  90 struct 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
 132 static unsigned int hpwdt_nmi_decoding;
 133 static unsigned int allow_kdump;
 134 static unsigned int priority;           /* hpwdt at end of die_notify list */
 135 static DEFINE_SPINLOCK(rom_lock);
 136 static void *cru_rom_addr;
 137 static struct cmn_registers cmn_regs;
 138
 139 extern 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
 147 asm(".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  */
 199 static 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  */
 256 static 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  */
 281 static 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
 311 static 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
 338 asm(".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  */
 383 static 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
 402 static 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  */
 418 static 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
 425 static 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
 434 static void hpwdt_ping(void)
 435 {
 436         iowrite16(reload, hpwdt_timer_reg);
 437 }
 438
 439 static 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
 457 static 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  */
 466 static 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_NMIUNKNOWN)
 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         }
 492 out:
 493         return NOTIFY_OK;
 494 }
 495 #endif /* CONFIG_HPWDT_NMI_DECODING */
 496
 497 /*
 498  *      /dev/watchdog handling
 499  */
 500 static 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
 513 static 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
 532 static 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
 561 static const struct watchdog_info ident = {
 562         .options = WDIOF_SETTIMEOUT |
 563                    WDIOF_KEEPALIVEPING |
 564                    WDIOF_MAGICCLOSE,
 565         .identity = "HP iLO2+ HW Watchdog Timer",
 566 };
 567
 568 static 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  */
 618 static 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
 627 static struct miscdevice hpwdt_miscdev = {
 628         .minor = WATCHDOG_MINOR,
 629         .name = "watchdog",
 630         .fops = &hpwdt_fops,
 631 };
 632
 633 #ifdef CONFIG_HPWDT_NMI_DECODING
 634 static 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 CONFIG_X86_LOCAL_APIC
 646 static 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         hpwdt_nmi_decoding = 1;
 653 }
 654 #else
 655 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
 656 {
 657         dev_warn(&dev->dev, "NMI decoding is disabled. "
 658                 "Your kernel does not support a NMI Watchdog.\n");
 659 }
 660 #endif /* CONFIG_X86_LOCAL_APIC */
 661
 662 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
 663 {
 664         int retval;
 665
 666         /*
 667          * We need to map the ROM to get the CRU service.
 668          * For 32 bit Operating Systems we need to go through the 32 Bit
 669          * BIOS Service Directory
 670          * For 64 bit Operating Systems we get that service through SMBIOS.
 671          */
 672         retval = detect_cru_service();
 673         if (retval < 0) {
 674                 dev_warn(&dev->dev,
 675                         "Unable to detect the %d Bit CRU Service.\n",
 676                         HPWDT_ARCH);
 677                 return retval;
 678         }
 679
 680         /*
 681          * We know this is the only CRU call we need to make so lets keep as
 682          * few instructions as possible once the NMI comes in.
 683          */
 684         cmn_regs.u1.rah = 0x0D;
 685         cmn_regs.u1.ral = 0x02;
 686
 687         /*
 688          * If the priority is set to 1, then we will be put first on the
 689          * die notify list to handle a critical NMI. The default is to
 690          * be last so other users of the NMI signal can function.
 691          */
 692         if (priority)
 693                 die_notifier.priority = 0x7FFFFFFF;
 694
 695         retval = register_die_notifier(&die_notifier);
 696         if (retval != 0) {
 697                 dev_warn(&dev->dev,
 698                         "Unable to register a die notifier (err=%d).\n",
 699                         retval);
 700                 if (cru_rom_addr)
 701                         iounmap(cru_rom_addr);
 702         }
 703
 704         dev_info(&dev->dev,
 705                         "HP Watchdog Timer Driver: NMI decoding initialized"
 706                         ", allow kernel dump: %s (default = 0/OFF)"
 707                         ", priority: %s (default = 0/LAST).\n",
 708                         (allow_kdump == 0) ? "OFF" : "ON",
 709                         (priority == 0) ? "LAST" : "FIRST");
 710         return 0;
 711 }
 712
 713 static void __devexit hpwdt_exit_nmi_decoding(void)
 714 {
 715         unregister_die_notifier(&die_notifier);
 716         if (cru_rom_addr)
 717                 iounmap(cru_rom_addr);
 718 }
 719 #else /* !CONFIG_HPWDT_NMI_DECODING */
 720 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
 721 {
 722 }
 723
 724 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
 725 {
 726         return 0;
 727 }
 728
 729 static void __devexit hpwdt_exit_nmi_decoding(void)
 730 {
 731 }
 732 #endif /* CONFIG_HPWDT_NMI_DECODING */
 733
 734 static int __devinit hpwdt_init_one(struct pci_dev *dev,
 735                                         const struct pci_device_id *ent)
 736 {
 737         int retval;
 738
 739         /*
 740          * Check if we can do NMI decoding or not
 741          */
 742         hpwdt_check_nmi_decoding(dev);
 743
 744         /*
 745          * First let's find out if we are on an iLO2+ server. We will
 746          * not run on a legacy ASM box.
 747          * So we only support the G5 ProLiant servers and higher.
 748          */
 749         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
 750                 dev_warn(&dev->dev,
 751                         "This server does not have an iLO2+ ASIC.\n");
 752                 return -ENODEV;
 753         }
 754
 755         if (pci_enable_device(dev)) {
 756                 dev_warn(&dev->dev,
 757                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 758                         ent->vendor, ent->device);
 759                 return -ENODEV;
 760         }
 761
 762         pci_mem_addr = pci_iomap(dev, 1, 0x80);
 763         if (!pci_mem_addr) {
 764                 dev_warn(&dev->dev,
 765                         "Unable to detect the iLO2+ server memory.\n");
 766                 retval = -ENOMEM;
 767                 goto error_pci_iomap;
 768         }
 769         hpwdt_timer_reg = pci_mem_addr + 0x70;
 770         hpwdt_timer_con = pci_mem_addr + 0x72;
 771
 772         /* Make sure that we have a valid soft_margin */
 773         if (hpwdt_change_timer(soft_margin))
 774                 hpwdt_change_timer(DEFAULT_MARGIN);
 775
 776         /* Initialize NMI Decoding functionality */
 777         retval = hpwdt_init_nmi_decoding(dev);
 778         if (retval != 0)
 779                 goto error_init_nmi_decoding;
 780
 781         retval = misc_register(&hpwdt_miscdev);
 782         if (retval < 0) {
 783                 dev_warn(&dev->dev,
 784                         "Unable to register miscdev on minor=%d (err=%d).\n",
 785                         WATCHDOG_MINOR, retval);
 786                 goto error_misc_register;
 787         }
 788
 789         dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
 790                         ", timer margin: %d seconds (nowayout=%d).\n",
 791                         HPWDT_VERSION, soft_margin, nowayout);
 792         return 0;
 793
 794 error_misc_register:
 795         hpwdt_exit_nmi_decoding();
 796 error_init_nmi_decoding:
 797         pci_iounmap(dev, pci_mem_addr);
 798 error_pci_iomap:
 799         pci_disable_device(dev);
 800         return retval;
 801 }
 802
 803 static void __devexit hpwdt_exit(struct pci_dev *dev)
 804 {
 805         if (!nowayout)
 806                 hpwdt_stop();
 807
 808         misc_deregister(&hpwdt_miscdev);
 809         hpwdt_exit_nmi_decoding();
 810         pci_iounmap(dev, pci_mem_addr);
 811         pci_disable_device(dev);
 812 }
 813
 814 static struct pci_driver hpwdt_driver = {
 815         .name = "hpwdt",
 816         .id_table = hpwdt_devices,
 817         .probe = hpwdt_init_one,
 818         .remove = __devexit_p(hpwdt_exit),
 819 };
 820
 821 static void __exit hpwdt_cleanup(void)
 822 {
 823         pci_unregister_driver(&hpwdt_driver);
 824 }
 825
 826 static int __init hpwdt_init(void)
 827 {
 828         return pci_register_driver(&hpwdt_driver);
 829 }
 830
 831 MODULE_AUTHOR("Tom Mingarelli");
 832 MODULE_DESCRIPTION("hp watchdog driver");
 833 MODULE_LICENSE("GPL");
 834 MODULE_VERSION(HPWDT_VERSION);
 835 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 836
 837 module_param(soft_margin, int, 0);
 838 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 839
 840 module_param(nowayout, int, 0);
 841 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 842                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 843
 844 #ifdef CONFIG_HPWDT_NMI_DECODING
 845 module_param(allow_kdump, int, 0);
 846 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
 847
 848 module_param(priority, int, 0);
 849 MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
 850                 " (default = 0/Last)\n");
 851 #endif /* !CONFIG_HPWDT_NMI_DECODING */
 852
 853 module_init(hpwdt_init);
 854 module_exit(hpwdt_cleanup);