git.oblomov.eu Git - linux-2.6/blob - 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/interrupt.h>
  20 #include <linux/io.h>
  21 #include <linux/irq.h>
  22 #include <linux/kernel.h>
  23 #include <linux/miscdevice.h>
  24 #include <linux/mm.h>
  25 #include <linux/module.h>
  26 #include <linux/kdebug.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/notifier.h>
  29 #include <linux/pci.h>
  30 #include <linux/pci_ids.h>
  31 #include <linux/reboot.h>
  32 #include <linux/sched.h>
  33 #include <linux/timer.h>
  34 #include <linux/types.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/watchdog.h>
  37 #include <linux/dmi.h>
  38 #include <linux/efi.h>
  39 #include <linux/string.h>
  40 #include <linux/bootmem.h>
  41 #include <linux/slab.h>
  42 #include <asm/dmi.h>
  43 #include <asm/desc.h>
  44 #include <asm/kdebug.h>
  45
  46 #define PCI_BIOS32_SD_VALUE             0x5F32335F      /* "_32_" */
  47 #define CRU_BIOS_SIGNATURE_VALUE        0x55524324
  48 #define PCI_BIOS32_PARAGRAPH_LEN        16
  49 #define PCI_ROM_BASE1                   0x000F0000
  50 #define ROM_SIZE                        0x10000
  51
  52 struct bios32_service_dir {
  53         u32 signature;
  54         u32 entry_point;
  55         u8 revision;
  56         u8 length;
  57         u8 checksum;
  58         u8 reserved[5];
  59 };
  60
  61 /*
  62  * smbios_entry_point     - defines SMBIOS entry point structure
  63  *
  64  * anchor[4]              - anchor string (_SM_)
  65  * checksum               - checksum of the entry point structure
  66  * length                 - length of the entry point structure
  67  * major_ver              - major version (02h for revision 2.1)
  68  * minor_ver              - minor version (01h for revision 2.1)
  69  * max_struct_size        - size of the largest SMBIOS structure
  70  * revision               - entry point structure revision implemented
  71  * formatted_area[5]      - reserved
  72  * intermediate_anchor[5] - intermediate anchor string (_DMI_)
  73  * intermediate_checksum  - intermediate checksum
  74  * table_length           - structure table length
  75  * table_address          - structure table address
  76  * table_num_structs      - number of SMBIOS structures present
  77  * bcd_revision           - BCD revision
  78  */
  79 struct smbios_entry_point {
  80         u8 anchor[4];
  81         u8 checksum;
  82         u8 length;
  83         u8 major_ver;
  84         u8 minor_ver;
  85         u16 max_struct_size;
  86         u8 revision;
  87         u8 formatted_area[5];
  88         u8 intermediate_anchor[5];
  89         u8 intermediate_checksum;
  90         u16 table_length;
  91         u32 table_address;
  92         u16 table_num_structs;
  93         u8 bcd_revision;
  94 };
  95
  96 /* type 212 */
  97 struct smbios_cru64_info {
  98         u8 type;
  99         u8 byte_length;
 100         u16 handle;
 101         u32 signature;
 102         u64 physical_address;
 103         u32 double_length;
 104         u32 double_offset;
 105 };
 106 #define SMBIOS_CRU64_INFORMATION        212
 107
 108 struct cmn_registers {
 109         union {
 110                 struct {
 111                         u8 ral;
 112                         u8 rah;
 113                         u16 rea2;
 114                 };
 115                 u32 reax;
 116         } u1;
 117         union {
 118                 struct {
 119                         u8 rbl;
 120                         u8 rbh;
 121                         u8 reb2l;
 122                         u8 reb2h;
 123                 };
 124                 u32 rebx;
 125         } u2;
 126         union {
 127                 struct {
 128                         u8 rcl;
 129                         u8 rch;
 130                         u16 rec2;
 131                 };
 132                 u32 recx;
 133         } u3;
 134         union {
 135                 struct {
 136                         u8 rdl;
 137                         u8 rdh;
 138                         u16 red2;
 139                 };
 140                 u32 redx;
 141         } u4;
 142
 143         u32 resi;
 144         u32 redi;
 145         u16 rds;
 146         u16 res;
 147         u32 reflags;
 148 }  __attribute__((packed));
 149
 150 #define DEFAULT_MARGIN  30
 151 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
 152 static unsigned int reload;                     /* the computed soft_margin */
 153 static int nowayout = WATCHDOG_NOWAYOUT;
 154 static char expect_release;
 155 static unsigned long hpwdt_is_open;
 156
 157 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
 158 static unsigned long __iomem *hpwdt_timer_reg;
 159 static unsigned long __iomem *hpwdt_timer_con;
 160
 161 static DEFINE_SPINLOCK(rom_lock);
 162
 163 static void *cru_rom_addr;
 164
 165 static struct cmn_registers cmn_regs;
 166
 167 static struct pci_device_id hpwdt_devices[] = {
 168         {
 169          .vendor = PCI_VENDOR_ID_COMPAQ,
 170          .device = 0xB203,
 171          .subvendor = PCI_ANY_ID,
 172          .subdevice = PCI_ANY_ID,
 173         },
 174         {0},                    /* terminate list */
 175 };
 176 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
 177
 178 /*
 179  *      bios_checksum
 180  */
 181 static int __devinit bios_checksum(const char __iomem *ptr, int len)
 182 {
 183         char sum = 0;
 184         int i;
 185
 186         /*
 187          * calculate checksum of size bytes. This should add up
 188          * to zero if we have a valid header.
 189          */
 190         for (i = 0; i < len; i++)
 191                 sum += ptr[i];
 192
 193         return ((sum == 0) && (len > 0));
 194 }
 195
 196 #ifndef CONFIG_X86_64
 197 /* --32 Bit Bios------------------------------------------------------------ */
 198
 199 #define HPWDT_ARCH      32
 200
 201 asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
 202                                unsigned long *pRomEntry)
 203 {
 204         asm("pushl       %ebp               \n\t"
 205             "movl        %esp, %ebp         \n\t"
 206             "pusha                          \n\t"
 207             "pushf                          \n\t"
 208             "push        %es                \n\t"
 209             "push        %ds                \n\t"
 210             "pop         %es                \n\t"
 211             "movl        8(%ebp),%eax       \n\t"
 212             "movl        4(%eax),%ebx       \n\t"
 213             "movl        8(%eax),%ecx       \n\t"
 214             "movl        12(%eax),%edx      \n\t"
 215             "movl        16(%eax),%esi      \n\t"
 216             "movl        20(%eax),%edi      \n\t"
 217             "movl        (%eax),%eax        \n\t"
 218             "push        %cs                \n\t"
 219             "call        *12(%ebp)          \n\t"
 220             "pushf                          \n\t"
 221             "pushl       %eax               \n\t"
 222             "movl        8(%ebp),%eax       \n\t"
 223             "movl        %ebx,4(%eax)       \n\t"
 224             "movl        %ecx,8(%eax)       \n\t"
 225             "movl        %edx,12(%eax)      \n\t"
 226             "movl        %esi,16(%eax)      \n\t"
 227             "movl        %edi,20(%eax)      \n\t"
 228             "movw        %ds,24(%eax)       \n\t"
 229             "movw        %es,26(%eax)       \n\t"
 230             "popl        %ebx               \n\t"
 231             "movl        %ebx,(%eax)        \n\t"
 232             "popl        %ebx               \n\t"
 233             "movl        %ebx,28(%eax)      \n\t"
 234             "pop         %es                \n\t"
 235             "popf                           \n\t"
 236             "popa                           \n\t"
 237             "leave                          \n\t" "ret");
 238 }
 239
 240 /*
 241  *      cru_detect
 242  *
 243  *      Routine Description:
 244  *      This function uses the 32-bit BIOS Service Directory record to
 245  *      search for a $CRU record.
 246  *
 247  *      Return Value:
 248  *      0        :  SUCCESS
 249  *      <0       :  FAILURE
 250  */
 251 static int __devinit cru_detect(unsigned long map_entry,
 252         unsigned long map_offset)
 253 {
 254         void *bios32_map;
 255         unsigned long *bios32_entrypoint;
 256         unsigned long cru_physical_address;
 257         unsigned long cru_length;
 258         unsigned long physical_bios_base = 0;
 259         unsigned long physical_bios_offset = 0;
 260         int retval = -ENODEV;
 261
 262         bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
 263
 264         if (bios32_map == NULL)
 265                 return -ENODEV;
 266
 267         bios32_entrypoint = bios32_map + map_offset;
 268
 269         cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 270
 271         asminline_call(&cmn_regs, bios32_entrypoint);
 272
 273         if (cmn_regs.u1.ral != 0) {
 274                 printk(KERN_WARNING
 275                        "hpwdt: Call succeeded but with an error: 0x%x\n",
 276                        cmn_regs.u1.ral);
 277         } else {
 278                 physical_bios_base = cmn_regs.u2.rebx;
 279                 physical_bios_offset = cmn_regs.u4.redx;
 280                 cru_length = cmn_regs.u3.recx;
 281                 cru_physical_address =
 282                     physical_bios_base + physical_bios_offset;
 283
 284                 /* If the values look OK, then map it in. */
 285                 if ((physical_bios_base + physical_bios_offset)) {
 286                         cru_rom_addr =
 287                             ioremap(cru_physical_address, cru_length);
 288                         if (cru_rom_addr)
 289                                 retval = 0;
 290                 }
 291
 292                 printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
 293                         physical_bios_base);
 294                 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
 295                         physical_bios_offset);
 296                 printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
 297                         cru_length);
 298                 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
 299                         (unsigned int)&cru_rom_addr);
 300         }
 301         iounmap(bios32_map);
 302         return retval;
 303 }
 304
 305 /*
 306  *      bios32_present
 307  *
 308  *      Routine Description:
 309  *      This function finds the 32-bit BIOS Service Directory
 310  *
 311  *      Return Value:
 312  *      0        :  SUCCESS
 313  *      <0       :  FAILURE
 314  */
 315 static int __devinit bios32_present(const char __iomem *p)
 316 {
 317         struct bios32_service_dir *bios_32_ptr;
 318         int length;
 319         unsigned long map_entry, map_offset;
 320
 321         bios_32_ptr = (struct bios32_service_dir *) p;
 322
 323         /*
 324          * Search for signature by checking equal to the swizzled value
 325          * instead of calling another routine to perform a strcmp.
 326          */
 327         if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
 328                 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
 329                 if (bios_checksum(p, length)) {
 330                         /*
 331                          * According to the spec, we're looking for the
 332                          * first 4KB-aligned address below the entrypoint
 333                          * listed in the header. The Service Directory code
 334                          * is guaranteed to occupy no more than 2 4KB pages.
 335                          */
 336                         map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
 337                         map_offset = bios_32_ptr->entry_point - map_entry;
 338
 339                         return cru_detect(map_entry, map_offset);
 340                 }
 341         }
 342         return -ENODEV;
 343 }
 344
 345 static int __devinit detect_cru_service(void)
 346 {
 347         char __iomem *p, *q;
 348         int rc = -1;
 349
 350         /*
 351          * Search from 0x0f0000 through 0x0fffff, inclusive.
 352          */
 353         p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
 354         if (p == NULL)
 355                 return -ENOMEM;
 356
 357         for (q = p; q < p + ROM_SIZE; q += 16) {
 358                 rc = bios32_present(q);
 359                 if (!rc)
 360                         break;
 361         }
 362         iounmap(p);
 363         return rc;
 364 }
 365
 366 #else
 367 /* --64 Bit Bios------------------------------------------------------------ */
 368
 369 #define HPWDT_ARCH      64
 370
 371 asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
 372                                unsigned long *pRomEntry)
 373 {
 374         asm("pushq      %rbp            \n\t"
 375             "movq       %rsp, %rbp      \n\t"
 376             "pushq      %rax            \n\t"
 377             "pushq      %rbx            \n\t"
 378             "pushq      %rdx            \n\t"
 379             "pushq      %r12            \n\t"
 380             "pushq      %r9             \n\t"
 381             "movq       %rsi, %r12      \n\t"
 382             "movq       %rdi, %r9       \n\t"
 383             "movl       4(%r9),%ebx     \n\t"
 384             "movl       8(%r9),%ecx     \n\t"
 385             "movl       12(%r9),%edx    \n\t"
 386             "movl       16(%r9),%esi    \n\t"
 387             "movl       20(%r9),%edi    \n\t"
 388             "movl       (%r9),%eax      \n\t"
 389             "call       *%r12           \n\t"
 390             "pushfq                     \n\t"
 391             "popq        %r12           \n\t"
 392             "popfq                      \n\t"
 393             "movl       %eax, (%r9)     \n\t"
 394             "movl       %ebx, 4(%r9)    \n\t"
 395             "movl       %ecx, 8(%r9)    \n\t"
 396             "movl       %edx, 12(%r9)   \n\t"
 397             "movl       %esi, 16(%r9)   \n\t"
 398             "movl       %edi, 20(%r9)   \n\t"
 399             "movq       %r12, %rax      \n\t"
 400             "movl       %eax, 28(%r9)   \n\t"
 401             "popq       %r9             \n\t"
 402             "popq       %r12            \n\t"
 403             "popq       %rdx            \n\t"
 404             "popq       %rbx            \n\t"
 405             "popq       %rax            \n\t"
 406             "leave                      \n\t" "ret");
 407 }
 408
 409 /*
 410  *      dmi_find_cru
 411  *
 412  *      Routine Description:
 413  *      This function checks wether or not a SMBIOS/DMI record is
 414  *      the 64bit CRU info or not
 415  *
 416  *      Return Value:
 417  *      0        :  SUCCESS - if record found
 418  *      <0       :  FAILURE - if record not found
 419  */
 420 static void __devinit dmi_find_cru(const struct dmi_header *dm)
 421 {
 422         struct smbios_cru64_info *smbios_cru64_ptr;
 423         unsigned long cru_physical_address;
 424
 425         if (dm->type == SMBIOS_CRU64_INFORMATION) {
 426                 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
 427                 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
 428                         cru_physical_address =
 429                             smbios_cru64_ptr->physical_address +
 430                             smbios_cru64_ptr->double_offset;
 431                         cru_rom_addr = ioremap(cru_physical_address,
 432                                     smbios_cru64_ptr->double_length);
 433                 }
 434         }
 435 }
 436
 437 /*
 438  *      dmi_table
 439  *
 440  *      Routine Description:
 441  *      Decode the SMBIOS/DMI table and check if we have a 64bit CRU record
 442  *      or not.
 443  *
 444  *      We have to be cautious here. We have seen BIOSes with DMI pointers
 445  *      pointing to completely the wrong place for example
 446  */
 447 static void __devinit dmi_table(u8 *buf, int len, int num,
 448                       void (*decode)(const struct dmi_header *))
 449 {
 450         u8 *data = buf;
 451         int i = 0;
 452
 453         /*
 454          *      Stop when we see all the items the table claimed to have
 455          *      OR we run off the end of the table (also happens)
 456          */
 457         while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
 458                 const struct dmi_header *dm = (const struct dmi_header *)data;
 459
 460                 /*
 461                  *  We want to know the total length (formated area and strings)
 462                  *  before decoding to make sure we won't run off the table in
 463                  *  dmi_decode or dmi_string
 464                  */
 465                 data += dm->length;
 466                 while ((data - buf < len - 1) && (data[0] || data[1]))
 467                         data++;
 468                 if (data - buf < len - 1)
 469                         decode(dm);
 470                 data += 2;
 471                 i++;
 472         }
 473 }
 474
 475 /*
 476  *      smbios_present
 477  *
 478  *      Routine Description:
 479  *      This function parses the SMBIOS entry point table to retrieve
 480  *      the 64 bit CRU Service.
 481  *
 482  *      Return Value:
 483  *      0        :  SUCCESS
 484  *      <0       :  FAILURE
 485  */
 486 static int __devinit smbios_present(const char __iomem *p)
 487 {
 488         struct smbios_entry_point *eps =
 489                 (struct smbios_entry_point *) p;
 490         int length;
 491         u8 *buf;
 492
 493         /* check if we have indeed the SMBIOS table entry point */
 494         if ((strncmp((char *)eps->anchor, "_SM_",
 495                              sizeof(eps->anchor))) == 0) {
 496                 length = eps->length;
 497
 498                 /* SMBIOS v2.1 implementation might use 0x1e */
 499                 if ((length == 0x1e) &&
 500                     (eps->major_ver == 2) &&
 501                     (eps->minor_ver == 1))
 502                         length = 0x1f;
 503
 504                 /*
 505                  * Now we will check:
 506                  * - SMBIOS checksum must be 0
 507                  * - intermediate anchor should be _DMI_
 508                  * - intermediate checksum should be 0
 509                  */
 510                 if ((bios_checksum(p, length)) &&
 511                     (strncmp((char *)eps->intermediate_anchor, "_DMI_",
 512                              sizeof(eps->intermediate_anchor)) == 0) &&
 513                     (bios_checksum(p+0x10, 15))) {
 514                         buf = ioremap(eps->table_address, eps->table_length);
 515                         if (buf == NULL)
 516                                 return -ENODEV;
 517
 518
 519                         /* Scan the DMI table for the 64 bit CRU service */
 520                         dmi_table(buf, eps->table_length,
 521                                   eps->table_num_structs, dmi_find_cru);
 522
 523                         iounmap(buf);
 524                         return 0;
 525                 }
 526         }
 527
 528         return -ENODEV;
 529 }
 530
 531 static int __devinit smbios_scan_machine(void)
 532 {
 533         char __iomem *p, *q;
 534         int rc;
 535
 536         if (efi_enabled) {
 537                 if (efi.smbios == EFI_INVALID_TABLE_ADDR)
 538                         return -ENODEV;
 539
 540                 p = ioremap(efi.smbios, 32);
 541                 if (p == NULL)
 542                         return -ENOMEM;
 543
 544                 rc = smbios_present(p);
 545                 iounmap(p);
 546         } else {
 547                 /*
 548                  * Search from 0x0f0000 through 0x0fffff, inclusive.
 549                  */
 550                 p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
 551                 if (p == NULL)
 552                         return -ENOMEM;
 553
 554                 for (q = p; q < p + ROM_SIZE; q += 16) {
 555                         rc = smbios_present(q);
 556                         if (!rc) {
 557                                 break;
 558                         }
 559                 }
 560                 iounmap(p);
 561         }
 562 }
 563
 564 static int __devinit detect_cru_service(void)
 565 {
 566         cru_rom_addr = NULL;
 567
 568         smbios_scan_machine();  /* will become dmi_walk(dmi_find_cru); */
 569
 570         /* if cru_rom_addr has been set then we found a CRU service */
 571         return ((cru_rom_addr != NULL)? 0: -ENODEV);
 572 }
 573
 574 /* ------------------------------------------------------------------------- */
 575
 576 #endif
 577
 578 /*
 579  *      NMI Handler
 580  */
 581 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
 582                             void *data)
 583 {
 584         static unsigned long rom_pl;
 585         static int die_nmi_called;
 586
 587         if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
 588                 return NOTIFY_OK;
 589
 590         spin_lock_irqsave(&rom_lock, rom_pl);
 591         if (!die_nmi_called)
 592                 asminline_call(&cmn_regs, cru_rom_addr);
 593         die_nmi_called = 1;
 594         spin_unlock_irqrestore(&rom_lock, rom_pl);
 595         if (cmn_regs.u1.ral == 0) {
 596                 printk(KERN_WARNING "hpwdt: An NMI occurred, "
 597                        "but unable to determine source.\n");
 598         } else {
 599                 panic("An NMI occurred, please see the Integrated "
 600                         "Management Log for details.\n");
 601         }
 602
 603         return NOTIFY_STOP;
 604 }
 605
 606 /*
 607  *      Watchdog operations
 608  */
 609 static void hpwdt_start(void)
 610 {
 611         reload = (soft_margin * 1000) / 128;
 612         iowrite16(reload, hpwdt_timer_reg);
 613         iowrite16(0x85, hpwdt_timer_con);
 614 }
 615
 616 static void hpwdt_stop(void)
 617 {
 618         unsigned long data;
 619
 620         data = ioread16(hpwdt_timer_con);
 621         data &= 0xFE;
 622         iowrite16(data, hpwdt_timer_con);
 623 }
 624
 625 static void hpwdt_ping(void)
 626 {
 627         iowrite16(reload, hpwdt_timer_reg);
 628 }
 629
 630 static int hpwdt_change_timer(int new_margin)
 631 {
 632         /* Arbitrary, can't find the card's limits */
 633         if (new_margin < 30 || new_margin > 600) {
 634                 printk(KERN_WARNING
 635                         "hpwdt: New value passed in is invalid: %d seconds.\n",
 636                         new_margin);
 637                 return -EINVAL;
 638         }
 639
 640         soft_margin = new_margin;
 641         printk(KERN_DEBUG
 642                 "hpwdt: New timer passed in is %d seconds.\n",
 643                 new_margin);
 644         reload = (soft_margin * 1000) / 128;
 645
 646         return 0;
 647 }
 648
 649 /*
 650  *      /dev/watchdog handling
 651  */
 652 static int hpwdt_open(struct inode *inode, struct file *file)
 653 {
 654         /* /dev/watchdog can only be opened once */
 655         if (test_and_set_bit(0, &hpwdt_is_open))
 656                 return -EBUSY;
 657
 658         /* Start the watchdog */
 659         hpwdt_start();
 660         hpwdt_ping();
 661
 662         return nonseekable_open(inode, file);
 663 }
 664
 665 static int hpwdt_release(struct inode *inode, struct file *file)
 666 {
 667         /* Stop the watchdog */
 668         if (expect_release == 42) {
 669                 hpwdt_stop();
 670         } else {
 671                 printk(KERN_CRIT
 672                         "hpwdt: Unexpected close, not stopping watchdog!\n");
 673                 hpwdt_ping();
 674         }
 675
 676         expect_release = 0;
 677
 678         /* /dev/watchdog is being closed, make sure it can be re-opened */
 679         clear_bit(0, &hpwdt_is_open);
 680
 681         return 0;
 682 }
 683
 684 static ssize_t hpwdt_write(struct file *file, const char __user *data,
 685         size_t len, loff_t *ppos)
 686 {
 687         /* See if we got the magic character 'V' and reload the timer */
 688         if (len) {
 689                 if (!nowayout) {
 690                         size_t i;
 691
 692                         /* note: just in case someone wrote the magic character
 693                          * five months ago... */
 694                         expect_release = 0;
 695
 696                         /* scan to see whether or not we got the magic char. */
 697                         for (i = 0; i != len; i++) {
 698                                 char c;
 699                                 if (get_user(c, data+i))
 700                                         return -EFAULT;
 701                                 if (c == 'V')
 702                                         expect_release = 42;
 703                         }
 704                 }
 705
 706                 /* someone wrote to us, we should reload the timer */
 707                 hpwdt_ping();
 708         }
 709
 710         return len;
 711 }
 712
 713 static struct watchdog_info ident = {
 714         .options = WDIOF_SETTIMEOUT |
 715                    WDIOF_KEEPALIVEPING |
 716                    WDIOF_MAGICCLOSE,
 717         .identity = "HP iLO2 HW Watchdog Timer",
 718 };
 719
 720 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
 721         unsigned long arg)
 722 {
 723         void __user *argp = (void __user *)arg;
 724         int __user *p = argp;
 725         int new_margin;
 726         int ret = -ENOTTY;
 727
 728         switch (cmd) {
 729         case WDIOC_GETSUPPORT:
 730                 ret = 0;
 731                 if (copy_to_user(argp, &ident, sizeof(ident)))
 732                         ret = -EFAULT;
 733                 break;
 734
 735         case WDIOC_GETSTATUS:
 736         case WDIOC_GETBOOTSTATUS:
 737                 ret = put_user(0, p);
 738                 break;
 739
 740         case WDIOC_KEEPALIVE:
 741                 hpwdt_ping();
 742                 ret = 0;
 743                 break;
 744
 745         case WDIOC_SETTIMEOUT:
 746                 ret = get_user(new_margin, p);
 747                 if (ret)
 748                         break;
 749
 750                 ret = hpwdt_change_timer(new_margin);
 751                 if (ret)
 752                         break;
 753
 754                 hpwdt_ping();
 755                 /* Fall */
 756         case WDIOC_GETTIMEOUT:
 757                 ret = put_user(soft_margin, p);
 758                 break;
 759         }
 760         return ret;
 761 }
 762
 763 /*
 764  *      Kernel interfaces
 765  */
 766 static struct file_operations hpwdt_fops = {
 767         .owner = THIS_MODULE,
 768         .llseek = no_llseek,
 769         .write = hpwdt_write,
 770         .unlocked_ioctl = hpwdt_ioctl,
 771         .open = hpwdt_open,
 772         .release = hpwdt_release,
 773 };
 774
 775 static struct miscdevice hpwdt_miscdev = {
 776         .minor = WATCHDOG_MINOR,
 777         .name = "watchdog",
 778         .fops = &hpwdt_fops,
 779 };
 780
 781 static struct notifier_block die_notifier = {
 782         .notifier_call = hpwdt_pretimeout,
 783         .priority = 0x7FFFFFFF,
 784 };
 785
 786 /*
 787  *      Init & Exit
 788  */
 789
 790 static int __devinit hpwdt_init_one(struct pci_dev *dev,
 791                                     const struct pci_device_id *ent)
 792 {
 793         int retval;
 794
 795         /*
 796          * First let's find out if we are on an iLO2 server. We will
 797          * not run on a legacy ASM box.
 798          */
 799         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
 800                 dev_warn(&dev->dev,
 801                        "This server does not have an iLO2 ASIC.\n");
 802                 return -ENODEV;
 803         }
 804
 805         if (pci_enable_device(dev)) {
 806                 dev_warn(&dev->dev,
 807                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 808                         ent->vendor, ent->device);
 809                 return -ENODEV;
 810         }
 811
 812         pci_mem_addr = pci_iomap(dev, 1, 0x80);
 813         if (!pci_mem_addr) {
 814                 dev_warn(&dev->dev,
 815                         "Unable to detect the iLO2 server memory.\n");
 816                 retval = -ENOMEM;
 817                 goto error_pci_iomap;
 818         }
 819         hpwdt_timer_reg = pci_mem_addr + 0x70;
 820         hpwdt_timer_con = pci_mem_addr + 0x72;
 821
 822         /* Make sure that we have a valid soft_margin */
 823         if (hpwdt_change_timer(soft_margin))
 824                 hpwdt_change_timer(DEFAULT_MARGIN);
 825
 826         /*
 827          * We need to map the ROM to get the CRU service.
 828          * For 32 bit Operating Systems we need to go through the 32 Bit
 829          * BIOS Service Directory
 830          * For 64 bit Operating Systems we get that service through SMBIOS.
 831          */
 832         retval = detect_cru_service();
 833         if (retval < 0) {
 834                 dev_warn(&dev->dev,
 835                        "Unable to detect the %d Bit CRU Service.\n",
 836                         HPWDT_ARCH);
 837                 goto error_get_cru;
 838         }
 839
 840         /*
 841          * We know this is the only CRU call we need to make so lets keep as
 842          * few instructions as possible once the NMI comes in.
 843          */
 844         cmn_regs.u1.rah = 0x0D;
 845         cmn_regs.u1.ral = 0x02;
 846
 847         retval = register_die_notifier(&die_notifier);
 848         if (retval != 0) {
 849                 dev_warn(&dev->dev,
 850                        "Unable to register a die notifier (err=%d).\n",
 851                         retval);
 852                 goto error_die_notifier;
 853         }
 854
 855         retval = misc_register(&hpwdt_miscdev);
 856         if (retval < 0) {
 857                 dev_warn(&dev->dev,
 858                         "Unable to register miscdev on minor=%d (err=%d).\n",
 859                         WATCHDOG_MINOR, retval);
 860                 goto error_misc_register;
 861         }
 862
 863         printk(KERN_INFO
 864                 "hp Watchdog Timer Driver: 1.00"
 865                 ", timer margin: %d seconds( nowayout=%d).\n",
 866                 soft_margin, nowayout);
 867
 868         return 0;
 869
 870 error_misc_register:
 871         unregister_die_notifier(&die_notifier);
 872 error_die_notifier:
 873         if (cru_rom_addr)
 874                 iounmap(cru_rom_addr);
 875 error_get_cru:
 876         pci_iounmap(dev, pci_mem_addr);
 877 error_pci_iomap:
 878         pci_disable_device(dev);
 879         return retval;
 880 }
 881
 882 static void __devexit hpwdt_exit(struct pci_dev *dev)
 883 {
 884         if (!nowayout)
 885                 hpwdt_stop();
 886
 887         misc_deregister(&hpwdt_miscdev);
 888         unregister_die_notifier(&die_notifier);
 889
 890         if (cru_rom_addr)
 891                 iounmap(cru_rom_addr);
 892         pci_iounmap(dev, pci_mem_addr);
 893         pci_disable_device(dev);
 894 }
 895
 896 static struct pci_driver hpwdt_driver = {
 897         .name = "hpwdt",
 898         .id_table = hpwdt_devices,
 899         .probe = hpwdt_init_one,
 900         .remove = __devexit_p(hpwdt_exit),
 901 };
 902
 903 static void __exit hpwdt_cleanup(void)
 904 {
 905         pci_unregister_driver(&hpwdt_driver);
 906 }
 907
 908 static int __init hpwdt_init(void)
 909 {
 910         return pci_register_driver(&hpwdt_driver);
 911 }
 912
 913 MODULE_AUTHOR("Tom Mingarelli");
 914 MODULE_DESCRIPTION("hp watchdog driver");
 915 MODULE_LICENSE("GPL");
 916 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 917
 918 module_param(soft_margin, int, 0);
 919 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 920
 921 module_param(nowayout, int, 0);
 922 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 923                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 924
 925 module_init(hpwdt_init);
 926 module_exit(hpwdt_cleanup);