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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/device.h>
  19 #include <linux/fs.h>
  20 #include <linux/init.h>
  21 #include <linux/io.h>
  22 #include <linux/bitops.h>
  23 #include <linux/kernel.h>
  24 #include <linux/miscdevice.h>
  25 #include <linux/module.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/pci.h>
  28 #include <linux/pci_ids.h>
  29 #include <linux/types.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/watchdog.h>
  32 #ifdef CONFIG_HPWDT_NMI_DECODING
  33 #include <linux/dmi.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/nmi.h>
  36 #include <linux/kdebug.h>
  37 #include <linux/notifier.h>
  38 #include <asm/cacheflush.h>
  39 #endif /* CONFIG_HPWDT_NMI_DECODING */
  40 #include <asm/nmi.h>
  41
  42 #define HPWDT_VERSION                   "1.3.1"
  43 #define SECS_TO_TICKS(secs)             ((secs) * 1000 / 128)
  44 #define TICKS_TO_SECS(ticks)            ((ticks) * 128 / 1000)
  45 #define HPWDT_MAX_TIMER                 TICKS_TO_SECS(65535)
  46 #define DEFAULT_MARGIN                  30
  47
  48 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
  49 static unsigned int reload;                     /* the computed soft_margin */
  50 static bool nowayout = WATCHDOG_NOWAYOUT;
  51 static char expect_release;
  52 static unsigned long hpwdt_is_open;
  53
  54 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
  55 static unsigned long __iomem *hpwdt_timer_reg;
  56 static unsigned long __iomem *hpwdt_timer_con;
  57
  58 static DEFINE_PCI_DEVICE_TABLE(hpwdt_devices) = {
  59         { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },   /* iLO2 */
  60         { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },       /* iLO3 */
  61         {0},                    /* terminate list */
  62 };
  63 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
  64
  65 #ifdef CONFIG_HPWDT_NMI_DECODING
  66 #define PCI_BIOS32_SD_VALUE             0x5F32335F      /* "_32_" */
  67 #define CRU_BIOS_SIGNATURE_VALUE        0x55524324
  68 #define PCI_BIOS32_PARAGRAPH_LEN        16
  69 #define PCI_ROM_BASE1                   0x000F0000
  70 #define ROM_SIZE                        0x10000
  71
  72 struct bios32_service_dir {
  73         u32 signature;
  74         u32 entry_point;
  75         u8 revision;
  76         u8 length;
  77         u8 checksum;
  78         u8 reserved[5];
  79 };
  80
  81 /* type 212 */
  82 struct smbios_cru64_info {
  83         u8 type;
  84         u8 byte_length;
  85         u16 handle;
  86         u32 signature;
  87         u64 physical_address;
  88         u32 double_length;
  89         u32 double_offset;
  90 };
  91 #define SMBIOS_CRU64_INFORMATION        212
  92
  93 /* type 219 */
  94 struct smbios_proliant_info {
  95         u8 type;
  96         u8 byte_length;
  97         u16 handle;
  98         u32 power_features;
  99         u32 omega_features;
 100         u32 reserved;
 101         u32 misc_features;
 102 };
 103 #define SMBIOS_ICRU_INFORMATION         219
 104
 105
 106 struct cmn_registers {
 107         union {
 108                 struct {
 109                         u8 ral;
 110                         u8 rah;
 111                         u16 rea2;
 112                 };
 113                 u32 reax;
 114         } u1;
 115         union {
 116                 struct {
 117                         u8 rbl;
 118                         u8 rbh;
 119                         u8 reb2l;
 120                         u8 reb2h;
 121                 };
 122                 u32 rebx;
 123         } u2;
 124         union {
 125                 struct {
 126                         u8 rcl;
 127                         u8 rch;
 128                         u16 rec2;
 129                 };
 130                 u32 recx;
 131         } u3;
 132         union {
 133                 struct {
 134                         u8 rdl;
 135                         u8 rdh;
 136                         u16 red2;
 137                 };
 138                 u32 redx;
 139         } u4;
 140
 141         u32 resi;
 142         u32 redi;
 143         u16 rds;
 144         u16 res;
 145         u32 reflags;
 146 }  __attribute__((packed));
 147
 148 static unsigned int hpwdt_nmi_decoding;
 149 static unsigned int allow_kdump = 1;
 150 static unsigned int is_icru;
 151 static DEFINE_SPINLOCK(rom_lock);
 152 static void *cru_rom_addr;
 153 static struct cmn_registers cmn_regs;
 154
 155 extern 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
 163 asm(".text                          \n\t"
 164     ".align 4                       \n"
 165     "asminline_call:                \n\t"
 166     "pushl       %ebp               \n\t"
 167     "movl        %esp, %ebp         \n\t"
 168     "pusha                          \n\t"
 169     "pushf                          \n\t"
 170     "push        %es                \n\t"
 171     "push        %ds                \n\t"
 172     "pop         %es                \n\t"
 173     "movl        8(%ebp),%eax       \n\t"
 174     "movl        4(%eax),%ebx       \n\t"
 175     "movl        8(%eax),%ecx       \n\t"
 176     "movl        12(%eax),%edx      \n\t"
 177     "movl        16(%eax),%esi      \n\t"
 178     "movl        20(%eax),%edi      \n\t"
 179     "movl        (%eax),%eax        \n\t"
 180     "push        %cs                \n\t"
 181     "call        *12(%ebp)          \n\t"
 182     "pushf                          \n\t"
 183     "pushl       %eax               \n\t"
 184     "movl        8(%ebp),%eax       \n\t"
 185     "movl        %ebx,4(%eax)       \n\t"
 186     "movl        %ecx,8(%eax)       \n\t"
 187     "movl        %edx,12(%eax)      \n\t"
 188     "movl        %esi,16(%eax)      \n\t"
 189     "movl        %edi,20(%eax)      \n\t"
 190     "movw        %ds,24(%eax)       \n\t"
 191     "movw        %es,26(%eax)       \n\t"
 192     "popl        %ebx               \n\t"
 193     "movl        %ebx,(%eax)        \n\t"
 194     "popl        %ebx               \n\t"
 195     "movl        %ebx,28(%eax)      \n\t"
 196     "pop         %es                \n\t"
 197     "popf                           \n\t"
 198     "popa                           \n\t"
 199     "leave                          \n\t"
 200     "ret                            \n\t"
 201     ".previous");
 202
 203
 204 /*
 205  *      cru_detect
 206  *
 207  *      Routine Description:
 208  *      This function uses the 32-bit BIOS Service Directory record to
 209  *      search for a $CRU record.
 210  *
 211  *      Return Value:
 212  *      0        :  SUCCESS
 213  *      <0       :  FAILURE
 214  */
 215 static int cru_detect(unsigned long map_entry,
 216         unsigned long map_offset)
 217 {
 218         void *bios32_map;
 219         unsigned long *bios32_entrypoint;
 220         unsigned long cru_physical_address;
 221         unsigned long cru_length;
 222         unsigned long physical_bios_base = 0;
 223         unsigned long physical_bios_offset = 0;
 224         int retval = -ENODEV;
 225
 226         bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
 227
 228         if (bios32_map == NULL)
 229                 return -ENODEV;
 230
 231         bios32_entrypoint = bios32_map + map_offset;
 232
 233         cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 234
 235         set_memory_x((unsigned long)bios32_map, 2);
 236         asminline_call(&cmn_regs, bios32_entrypoint);
 237
 238         if (cmn_regs.u1.ral != 0) {
 239                 pr_warn("Call succeeded but with an error: 0x%x\n",
 240                         cmn_regs.u1.ral);
 241         } else {
 242                 physical_bios_base = cmn_regs.u2.rebx;
 243                 physical_bios_offset = cmn_regs.u4.redx;
 244                 cru_length = cmn_regs.u3.recx;
 245                 cru_physical_address =
 246                         physical_bios_base + physical_bios_offset;
 247
 248                 /* If the values look OK, then map it in. */
 249                 if ((physical_bios_base + physical_bios_offset)) {
 250                         cru_rom_addr =
 251                                 ioremap(cru_physical_address, cru_length);
 252                         if (cru_rom_addr) {
 253                                 set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
 254                                         (cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
 255                                 retval = 0;
 256                         }
 257                 }
 258
 259                 pr_debug("CRU Base Address:   0x%lx\n", physical_bios_base);
 260                 pr_debug("CRU Offset Address: 0x%lx\n", physical_bios_offset);
 261                 pr_debug("CRU Length:         0x%lx\n", cru_length);
 262                 pr_debug("CRU Mapped Address: %p\n", &cru_rom_addr);
 263         }
 264         iounmap(bios32_map);
 265         return retval;
 266 }
 267
 268 /*
 269  *      bios_checksum
 270  */
 271 static int bios_checksum(const char __iomem *ptr, int len)
 272 {
 273         char sum = 0;
 274         int i;
 275
 276         /*
 277          * calculate checksum of size bytes. This should add up
 278          * to zero if we have a valid header.
 279          */
 280         for (i = 0; i < len; i++)
 281                 sum += ptr[i];
 282
 283         return ((sum == 0) && (len > 0));
 284 }
 285
 286 /*
 287  *      bios32_present
 288  *
 289  *      Routine Description:
 290  *      This function finds the 32-bit BIOS Service Directory
 291  *
 292  *      Return Value:
 293  *      0        :  SUCCESS
 294  *      <0       :  FAILURE
 295  */
 296 static int bios32_present(const char __iomem *p)
 297 {
 298         struct bios32_service_dir *bios_32_ptr;
 299         int length;
 300         unsigned long map_entry, map_offset;
 301
 302         bios_32_ptr = (struct bios32_service_dir *) p;
 303
 304         /*
 305          * Search for signature by checking equal to the swizzled value
 306          * instead of calling another routine to perform a strcmp.
 307          */
 308         if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
 309                 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
 310                 if (bios_checksum(p, length)) {
 311                         /*
 312                          * According to the spec, we're looking for the
 313                          * first 4KB-aligned address below the entrypoint
 314                          * listed in the header. The Service Directory code
 315                          * is guaranteed to occupy no more than 2 4KB pages.
 316                          */
 317                         map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
 318                         map_offset = bios_32_ptr->entry_point - map_entry;
 319
 320                         return cru_detect(map_entry, map_offset);
 321                 }
 322         }
 323         return -ENODEV;
 324 }
 325
 326 static int detect_cru_service(void)
 327 {
 328         char __iomem *p, *q;
 329         int rc = -1;
 330
 331         /*
 332          * Search from 0x0f0000 through 0x0fffff, inclusive.
 333          */
 334         p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
 335         if (p == NULL)
 336                 return -ENOMEM;
 337
 338         for (q = p; q < p + ROM_SIZE; q += 16) {
 339                 rc = bios32_present(q);
 340                 if (!rc)
 341                         break;
 342         }
 343         iounmap(p);
 344         return rc;
 345 }
 346 /* ------------------------------------------------------------------------- */
 347 #endif /* CONFIG_X86_32 */
 348 #ifdef CONFIG_X86_64
 349 /* --64 Bit Bios------------------------------------------------------------ */
 350
 351 #define HPWDT_ARCH      64
 352
 353 asm(".text                      \n\t"
 354     ".align 4                   \n"
 355     "asminline_call:            \n\t"
 356     "pushq      %rbp            \n\t"
 357     "movq       %rsp, %rbp      \n\t"
 358     "pushq      %rax            \n\t"
 359     "pushq      %rbx            \n\t"
 360     "pushq      %rdx            \n\t"
 361     "pushq      %r12            \n\t"
 362     "pushq      %r9             \n\t"
 363     "movq       %rsi, %r12      \n\t"
 364     "movq       %rdi, %r9       \n\t"
 365     "movl       4(%r9),%ebx     \n\t"
 366     "movl       8(%r9),%ecx     \n\t"
 367     "movl       12(%r9),%edx    \n\t"
 368     "movl       16(%r9),%esi    \n\t"
 369     "movl       20(%r9),%edi    \n\t"
 370     "movl       (%r9),%eax      \n\t"
 371     "call       *%r12           \n\t"
 372     "pushfq                     \n\t"
 373     "popq        %r12           \n\t"
 374     "movl       %eax, (%r9)     \n\t"
 375     "movl       %ebx, 4(%r9)    \n\t"
 376     "movl       %ecx, 8(%r9)    \n\t"
 377     "movl       %edx, 12(%r9)   \n\t"
 378     "movl       %esi, 16(%r9)   \n\t"
 379     "movl       %edi, 20(%r9)   \n\t"
 380     "movq       %r12, %rax      \n\t"
 381     "movl       %eax, 28(%r9)   \n\t"
 382     "popq       %r9             \n\t"
 383     "popq       %r12            \n\t"
 384     "popq       %rdx            \n\t"
 385     "popq       %rbx            \n\t"
 386     "popq       %rax            \n\t"
 387     "leave                      \n\t"
 388     "ret                        \n\t"
 389     ".previous");
 390
 391 /*
 392  *      dmi_find_cru
 393  *
 394  *      Routine Description:
 395  *      This function checks whether or not a SMBIOS/DMI record is
 396  *      the 64bit CRU info or not
 397  */
 398 static void dmi_find_cru(const struct dmi_header *dm, void *dummy)
 399 {
 400         struct smbios_cru64_info *smbios_cru64_ptr;
 401         unsigned long cru_physical_address;
 402
 403         if (dm->type == SMBIOS_CRU64_INFORMATION) {
 404                 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
 405                 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
 406                         cru_physical_address =
 407                                 smbios_cru64_ptr->physical_address +
 408                                 smbios_cru64_ptr->double_offset;
 409                         cru_rom_addr = ioremap(cru_physical_address,
 410                                 smbios_cru64_ptr->double_length);
 411                         set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
 412                                 smbios_cru64_ptr->double_length >> PAGE_SHIFT);
 413                 }
 414         }
 415 }
 416
 417 static int detect_cru_service(void)
 418 {
 419         cru_rom_addr = NULL;
 420
 421         dmi_walk(dmi_find_cru, NULL);
 422
 423         /* if cru_rom_addr has been set then we found a CRU service */
 424         return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
 425 }
 426 /* ------------------------------------------------------------------------- */
 427 #endif /* CONFIG_X86_64 */
 428 #endif /* CONFIG_HPWDT_NMI_DECODING */
 429
 430 /*
 431  *      Watchdog operations
 432  */
 433 static void hpwdt_start(void)
 434 {
 435         reload = SECS_TO_TICKS(soft_margin);
 436         iowrite16(reload, hpwdt_timer_reg);
 437         iowrite8(0x85, hpwdt_timer_con);
 438 }
 439
 440 static void hpwdt_stop(void)
 441 {
 442         unsigned long data;
 443
 444         data = ioread8(hpwdt_timer_con);
 445         data &= 0xFE;
 446         iowrite8(data, hpwdt_timer_con);
 447 }
 448
 449 static void hpwdt_ping(void)
 450 {
 451         iowrite16(reload, hpwdt_timer_reg);
 452 }
 453
 454 static int hpwdt_change_timer(int new_margin)
 455 {
 456         if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
 457                 pr_warn("New value passed in is invalid: %d seconds\n",
 458                         new_margin);
 459                 return -EINVAL;
 460         }
 461
 462         soft_margin = new_margin;
 463         pr_debug("New timer passed in is %d seconds\n", new_margin);
 464         reload = SECS_TO_TICKS(soft_margin);
 465
 466         return 0;
 467 }
 468
 469 static int hpwdt_time_left(void)
 470 {
 471         return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
 472 }
 473
 474 #ifdef CONFIG_HPWDT_NMI_DECODING
 475 /*
 476  *      NMI Handler
 477  */
 478 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
 479 {
 480         unsigned long rom_pl;
 481         static int die_nmi_called;
 482
 483         if (!hpwdt_nmi_decoding)
 484                 goto out;
 485
 486         spin_lock_irqsave(&rom_lock, rom_pl);
 487         if (!die_nmi_called && !is_icru)
 488                 asminline_call(&cmn_regs, cru_rom_addr);
 489         die_nmi_called = 1;
 490         spin_unlock_irqrestore(&rom_lock, rom_pl);
 491
 492         if (allow_kdump)
 493                 hpwdt_stop();
 494
 495         if (!is_icru) {
 496                 if (cmn_regs.u1.ral == 0) {
 497                         panic("An NMI occurred, "
 498                                 "but unable to determine source.\n");
 499                 }
 500         }
 501         panic("An NMI occurred, please see the Integrated "
 502                 "Management Log for details.\n");
 503
 504 out:
 505         return NMI_DONE;
 506 }
 507 #endif /* CONFIG_HPWDT_NMI_DECODING */
 508
 509 /*
 510  *      /dev/watchdog handling
 511  */
 512 static int hpwdt_open(struct inode *inode, struct file *file)
 513 {
 514         /* /dev/watchdog can only be opened once */
 515         if (test_and_set_bit(0, &hpwdt_is_open))
 516                 return -EBUSY;
 517
 518         /* Start the watchdog */
 519         hpwdt_start();
 520         hpwdt_ping();
 521
 522         return nonseekable_open(inode, file);
 523 }
 524
 525 static int hpwdt_release(struct inode *inode, struct file *file)
 526 {
 527         /* Stop the watchdog */
 528         if (expect_release == 42) {
 529                 hpwdt_stop();
 530         } else {
 531                 pr_crit("Unexpected close, not stopping watchdog!\n");
 532                 hpwdt_ping();
 533         }
 534
 535         expect_release = 0;
 536
 537         /* /dev/watchdog is being closed, make sure it can be re-opened */
 538         clear_bit(0, &hpwdt_is_open);
 539
 540         return 0;
 541 }
 542
 543 static ssize_t hpwdt_write(struct file *file, const char __user *data,
 544         size_t len, loff_t *ppos)
 545 {
 546         /* See if we got the magic character 'V' and reload the timer */
 547         if (len) {
 548                 if (!nowayout) {
 549                         size_t i;
 550
 551                         /* note: just in case someone wrote the magic character
 552                          * five months ago... */
 553                         expect_release = 0;
 554
 555                         /* scan to see whether or not we got the magic char. */
 556                         for (i = 0; i != len; i++) {
 557                                 char c;
 558                                 if (get_user(c, data + i))
 559                                         return -EFAULT;
 560                                 if (c == 'V')
 561                                         expect_release = 42;
 562                         }
 563                 }
 564
 565                 /* someone wrote to us, we should reload the timer */
 566                 hpwdt_ping();
 567         }
 568
 569         return len;
 570 }
 571
 572 static const struct watchdog_info ident = {
 573         .options = WDIOF_SETTIMEOUT |
 574                    WDIOF_KEEPALIVEPING |
 575                    WDIOF_MAGICCLOSE,
 576         .identity = "HP iLO2+ HW Watchdog Timer",
 577 };
 578
 579 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
 580         unsigned long arg)
 581 {
 582         void __user *argp = (void __user *)arg;
 583         int __user *p = argp;
 584         int new_margin;
 585         int ret = -ENOTTY;
 586
 587         switch (cmd) {
 588         case WDIOC_GETSUPPORT:
 589                 ret = 0;
 590                 if (copy_to_user(argp, &ident, sizeof(ident)))
 591                         ret = -EFAULT;
 592                 break;
 593
 594         case WDIOC_GETSTATUS:
 595         case WDIOC_GETBOOTSTATUS:
 596                 ret = put_user(0, p);
 597                 break;
 598
 599         case WDIOC_KEEPALIVE:
 600                 hpwdt_ping();
 601                 ret = 0;
 602                 break;
 603
 604         case WDIOC_SETTIMEOUT:
 605                 ret = get_user(new_margin, p);
 606                 if (ret)
 607                         break;
 608
 609                 ret = hpwdt_change_timer(new_margin);
 610                 if (ret)
 611                         break;
 612
 613                 hpwdt_ping();
 614                 /* Fall */
 615         case WDIOC_GETTIMEOUT:
 616                 ret = put_user(soft_margin, p);
 617                 break;
 618
 619         case WDIOC_GETTIMELEFT:
 620                 ret = put_user(hpwdt_time_left(), p);
 621                 break;
 622         }
 623         return ret;
 624 }
 625
 626 /*
 627  *      Kernel interfaces
 628  */
 629 static const struct file_operations hpwdt_fops = {
 630         .owner = THIS_MODULE,
 631         .llseek = no_llseek,
 632         .write = hpwdt_write,
 633         .unlocked_ioctl = hpwdt_ioctl,
 634         .open = hpwdt_open,
 635         .release = hpwdt_release,
 636 };
 637
 638 static struct miscdevice hpwdt_miscdev = {
 639         .minor = WATCHDOG_MINOR,
 640         .name = "watchdog",
 641         .fops = &hpwdt_fops,
 642 };
 643
 644 /*
 645  *      Init & Exit
 646  */
 647
 648 #ifdef CONFIG_HPWDT_NMI_DECODING
 649 #ifdef CONFIG_X86_LOCAL_APIC
 650 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
 651 {
 652         /*
 653          * If nmi_watchdog is turned off then we can turn on
 654          * our nmi decoding capability.
 655          */
 656         hpwdt_nmi_decoding = 1;
 657 }
 658 #else
 659 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
 660 {
 661         dev_warn(&dev->dev, "NMI decoding is disabled. "
 662                 "Your kernel does not support a NMI Watchdog.\n");
 663 }
 664 #endif /* CONFIG_X86_LOCAL_APIC */
 665
 666 /*
 667  *      dmi_find_icru
 668  *
 669  *      Routine Description:
 670  *      This function checks whether or not we are on an iCRU-based server.
 671  *      This check is independent of architecture and needs to be made for
 672  *      any ProLiant system.
 673  */
 674 static void dmi_find_icru(const struct dmi_header *dm, void *dummy)
 675 {
 676         struct smbios_proliant_info *smbios_proliant_ptr;
 677
 678         if (dm->type == SMBIOS_ICRU_INFORMATION) {
 679                 smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
 680                 if (smbios_proliant_ptr->misc_features & 0x01)
 681                         is_icru = 1;
 682         }
 683 }
 684
 685 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 686 {
 687         int retval;
 688
 689         /*
 690          * On typical CRU-based systems we need to map that service in
 691          * the BIOS. For 32 bit Operating Systems we need to go through
 692          * the 32 Bit BIOS Service Directory. For 64 bit Operating
 693          * Systems we get that service through SMBIOS.
 694          *
 695          * On systems that support the new iCRU service all we need to
 696          * do is call dmi_walk to get the supported flag value and skip
 697          * the old cru detect code.
 698          */
 699         dmi_walk(dmi_find_icru, NULL);
 700         if (!is_icru) {
 701
 702                 /*
 703                 * We need to map the ROM to get the CRU service.
 704                 * For 32 bit Operating Systems we need to go through the 32 Bit
 705                 * BIOS Service Directory
 706                 * For 64 bit Operating Systems we get that service through SMBIOS.
 707                 */
 708                 retval = detect_cru_service();
 709                 if (retval < 0) {
 710                         dev_warn(&dev->dev,
 711                                 "Unable to detect the %d Bit CRU Service.\n",
 712                                 HPWDT_ARCH);
 713                         return retval;
 714                 }
 715
 716                 /*
 717                 * We know this is the only CRU call we need to make so lets keep as
 718                 * few instructions as possible once the NMI comes in.
 719                 */
 720                 cmn_regs.u1.rah = 0x0D;
 721                 cmn_regs.u1.ral = 0x02;
 722         }
 723
 724         /*
 725          * Only one function can register for NMI_UNKNOWN
 726          */
 727         retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
 728         if (retval)
 729                 goto error;
 730         retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
 731         if (retval)
 732                 goto error1;
 733         retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
 734         if (retval)
 735                 goto error2;
 736
 737         dev_info(&dev->dev,
 738                         "HP Watchdog Timer Driver: NMI decoding initialized"
 739                         ", allow kernel dump: %s (default = 0/OFF)\n",
 740                         (allow_kdump == 0) ? "OFF" : "ON");
 741         return 0;
 742
 743 error2:
 744         unregister_nmi_handler(NMI_SERR, "hpwdt");
 745 error1:
 746         unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
 747 error:
 748         dev_warn(&dev->dev,
 749                 "Unable to register a die notifier (err=%d).\n",
 750                 retval);
 751         if (cru_rom_addr)
 752                 iounmap(cru_rom_addr);
 753         return retval;
 754 }
 755
 756 static void hpwdt_exit_nmi_decoding(void)
 757 {
 758         unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
 759         unregister_nmi_handler(NMI_SERR, "hpwdt");
 760         unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
 761         if (cru_rom_addr)
 762                 iounmap(cru_rom_addr);
 763 }
 764 #else /* !CONFIG_HPWDT_NMI_DECODING */
 765 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
 766 {
 767 }
 768
 769 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 770 {
 771         return 0;
 772 }
 773
 774 static void hpwdt_exit_nmi_decoding(void)
 775 {
 776 }
 777 #endif /* CONFIG_HPWDT_NMI_DECODING */
 778
 779 static int hpwdt_init_one(struct pci_dev *dev,
 780                                         const struct pci_device_id *ent)
 781 {
 782         int retval;
 783
 784         /*
 785          * Check if we can do NMI decoding or not
 786          */
 787         hpwdt_check_nmi_decoding(dev);
 788
 789         /*
 790          * First let's find out if we are on an iLO2+ server. We will
 791          * not run on a legacy ASM box.
 792          * So we only support the G5 ProLiant servers and higher.
 793          */
 794         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
 795                 dev_warn(&dev->dev,
 796                         "This server does not have an iLO2+ ASIC.\n");
 797                 return -ENODEV;
 798         }
 799
 800         if (pci_enable_device(dev)) {
 801                 dev_warn(&dev->dev,
 802                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 803                         ent->vendor, ent->device);
 804                 return -ENODEV;
 805         }
 806
 807         pci_mem_addr = pci_iomap(dev, 1, 0x80);
 808         if (!pci_mem_addr) {
 809                 dev_warn(&dev->dev,
 810                         "Unable to detect the iLO2+ server memory.\n");
 811                 retval = -ENOMEM;
 812                 goto error_pci_iomap;
 813         }
 814         hpwdt_timer_reg = pci_mem_addr + 0x70;
 815         hpwdt_timer_con = pci_mem_addr + 0x72;
 816
 817         /* Make sure that timer is disabled until /dev/watchdog is opened */
 818         hpwdt_stop();
 819
 820         /* Make sure that we have a valid soft_margin */
 821         if (hpwdt_change_timer(soft_margin))
 822                 hpwdt_change_timer(DEFAULT_MARGIN);
 823
 824         /* Initialize NMI Decoding functionality */
 825         retval = hpwdt_init_nmi_decoding(dev);
 826         if (retval != 0)
 827                 goto error_init_nmi_decoding;
 828
 829         retval = misc_register(&hpwdt_miscdev);
 830         if (retval < 0) {
 831                 dev_warn(&dev->dev,
 832                         "Unable to register miscdev on minor=%d (err=%d).\n",
 833                         WATCHDOG_MINOR, retval);
 834                 goto error_misc_register;
 835         }
 836
 837         dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
 838                         ", timer margin: %d seconds (nowayout=%d).\n",
 839                         HPWDT_VERSION, soft_margin, nowayout);
 840         return 0;
 841
 842 error_misc_register:
 843         hpwdt_exit_nmi_decoding();
 844 error_init_nmi_decoding:
 845         pci_iounmap(dev, pci_mem_addr);
 846 error_pci_iomap:
 847         pci_disable_device(dev);
 848         return retval;
 849 }
 850
 851 static void hpwdt_exit(struct pci_dev *dev)
 852 {
 853         if (!nowayout)
 854                 hpwdt_stop();
 855
 856         misc_deregister(&hpwdt_miscdev);
 857         hpwdt_exit_nmi_decoding();
 858         pci_iounmap(dev, pci_mem_addr);
 859         pci_disable_device(dev);
 860 }
 861
 862 static struct pci_driver hpwdt_driver = {
 863         .name = "hpwdt",
 864         .id_table = hpwdt_devices,
 865         .probe = hpwdt_init_one,
 866         .remove = hpwdt_exit,
 867 };
 868
 869 MODULE_AUTHOR("Tom Mingarelli");
 870 MODULE_DESCRIPTION("hp watchdog driver");
 871 MODULE_LICENSE("GPL");
 872 MODULE_VERSION(HPWDT_VERSION);
 873 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 874
 875 module_param(soft_margin, int, 0);
 876 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 877
 878 module_param(nowayout, bool, 0);
 879 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 880                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 881
 882 #ifdef CONFIG_HPWDT_NMI_DECODING
 883 module_param(allow_kdump, int, 0);
 884 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
 885 #endif /* !CONFIG_HPWDT_NMI_DECODING */
 886
 887 module_pci_driver(hpwdt_driver);