]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/commitdiff
[WATCHDOG] HP ProLiant WatchDog driver
authorThomas Mingarelli <thomas.mingarelli@hp.com>
Tue, 4 Dec 2007 17:41:54 +0000 (17:41 +0000)
committerWim Van Sebroeck <wim@iguana.be>
Mon, 18 Feb 2008 17:06:21 +0000 (17:06 +0000)
Hp is providing a Hardware WatchDog Timer driver that will only work with the
specific HW Timer located in the HP ProLiant iLO 2 ASIC. The iLO 2 HW Timer
will generate a Non-maskable Interrupt (NMI) 9 seconds before physically
resetting the server, by removing power, so that the event can be logged to
the HP Integrated Management Log (IML), a Non-Volatile Random Access Memory
(NVRAM). The logging of the event is performed using the HP ProLiant ROM via
an Industry Standard access known as a BIOS Service Directory Entry.

Signed-off-by: Thomas Mingarelli <thomas.mingarelli@hp.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/Kconfig
drivers/watchdog/Makefile
drivers/watchdog/hpwdt.c [new file with mode: 0644]

index 591e3f399114e1da3ff06a540949a9e58b03d251..254d115cafab0feeed787c778bb73e04f46dc19e 100644 (file)
@@ -402,6 +402,18 @@ config IT8712F_WDT
          To compile this driver as a module, choose M here: the
          module will be called it8712f_wdt.
 
+config HP_WATCHDOG
+       tristate "HP Proliant iLO 2 Hardware Watchdog Timer"
+       depends on X86
+       help
+         A software monitoring watchdog and NMI sourcing driver. This driver
+         will detect lockups and provide stack trace. Also, when an NMI
+         occurs this driver will make the necessary BIOS calls to log
+         the cause of the NMI. This is a driver that will only load on a
+         HP ProLiant system with a minimum of iLO2 support.
+         To compile this driver as a module, choose M here: the
+         module will be called hpwdt.
+
 config SC1200_WDT
        tristate "National Semiconductor PC87307/PC97307 (ala SC1200) Watchdog"
        depends on X86
index 90e4bbffbbfd254f0000c58cea9a10ca1b7ee0c7..f3fb170fe5c6383ef23d6017c09e6831e703bf5a 100644 (file)
@@ -67,6 +67,7 @@ obj-$(CONFIG_WAFER_WDT) += wafer5823wdt.o
 obj-$(CONFIG_I6300ESB_WDT) += i6300esb.o
 obj-$(CONFIG_ITCO_WDT) += iTCO_wdt.o iTCO_vendor_support.o
 obj-$(CONFIG_IT8712F_WDT) += it8712f_wdt.o
+obj-$(CONFIG_HP_WATCHDOG) += hpwdt.o
 obj-$(CONFIG_SC1200_WDT) += sc1200wdt.o
 obj-$(CONFIG_SCx200_WDT) += scx200_wdt.o
 obj-$(CONFIG_PC87413_WDT) += pc87413_wdt.o
diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
new file mode 100644 (file)
index 0000000..a2e174b
--- /dev/null
@@ -0,0 +1,926 @@
+/*
+ *     HP WatchDog Driver
+ *     based on
+ *
+ *     SoftDog 0.05:   A Software Watchdog Device
+ *
+ *     (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *     Thomas Mingarelli <thomas.mingarelli@hp.com>
+ *
+ *     This program is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License
+ *     version 2 as published by the Free Software Foundation
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/kdebug.h>
+#include <linux/moduleparam.h>
+#include <linux/notifier.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+#include <linux/dmi.h>
+#include <linux/efi.h>
+#include <linux/string.h>
+#include <linux/bootmem.h>
+#include <linux/slab.h>
+#include <asm/dmi.h>
+#include <asm/desc.h>
+#include <asm/kdebug.h>
+
+#define PCI_BIOS32_SD_VALUE            0x5F32335F      /* "_32_" */
+#define CRU_BIOS_SIGNATURE_VALUE       0x55524324
+#define PCI_BIOS32_PARAGRAPH_LEN       16
+#define PCI_ROM_BASE1                  0x000F0000
+#define ROM_SIZE                       0x10000
+
+struct bios32_service_dir {
+       u32 signature;
+       u32 entry_point;
+       u8 revision;
+       u8 length;
+       u8 checksum;
+       u8 reserved[5];
+};
+
+/*
+ * smbios_entry_point     - defines SMBIOS entry point structure
+ *
+ * anchor[4]              - anchor string (_SM_)
+ * checksum               - checksum of the entry point structure
+ * length                 - length of the entry point structure
+ * major_ver              - major version (02h for revision 2.1)
+ * minor_ver              - minor version (01h for revision 2.1)
+ * max_struct_size        - size of the largest SMBIOS structure
+ * revision               - entry point structure revision implemented
+ * formatted_area[5]      - reserved
+ * intermediate_anchor[5] - intermediate anchor string (_DMI_)
+ * intermediate_checksum  - intermediate checksum
+ * table_length           - structure table length
+ * table_address          - structure table address
+ * table_num_structs      - number of SMBIOS structures present
+ * bcd_revision           - BCD revision
+ */
+struct smbios_entry_point {
+       u8 anchor[4];
+       u8 checksum;
+       u8 length;
+       u8 major_ver;
+       u8 minor_ver;
+       u16 max_struct_size;
+       u8 revision;
+       u8 formatted_area[5];
+       u8 intermediate_anchor[5];
+       u8 intermediate_checksum;
+       u16 table_length;
+       u64 table_address;
+       u16 table_num_structs;
+       u8 bcd_revision;
+};
+
+/* type 212 */
+struct smbios_cru64_info {
+       u8 type;
+       u8 byte_length;
+       u16 handle;
+       u32 signature;
+       u64 physical_address;
+       u32 double_length;
+       u32 double_offset;
+};
+#define SMBIOS_CRU64_INFORMATION       212
+
+struct cmn_registers {
+       union {
+               struct {
+                       u8 ral;
+                       u8 rah;
+                       u16 rea2;
+               };
+               u32 reax;
+       } u1;
+       union {
+               struct {
+                       u8 rbl;
+                       u8 rbh;
+                       u8 reb2l;
+                       u8 reb2h;
+               };
+               u32 rebx;
+       } u2;
+       union {
+               struct {
+                       u8 rcl;
+                       u8 rch;
+                       u16 rec2;
+               };
+               u32 recx;
+       } u3;
+       union {
+               struct {
+                       u8 rdl;
+                       u8 rdh;
+                       u16 red2;
+               };
+               u32 redx;
+       } u4;
+
+       u32 resi;
+       u32 redi;
+       u16 rds;
+       u16 res;
+       u32 reflags;
+}  __attribute__((packed));
+
+#define DEFAULT_MARGIN 30
+static unsigned int soft_margin = DEFAULT_MARGIN;      /* in seconds */
+static unsigned int reload;                    /* the computed soft_margin */
+static int nowayout = WATCHDOG_NOWAYOUT;
+static char expect_release;
+static unsigned long hpwdt_is_open;
+
+static void __iomem *pci_mem_addr;             /* the PCI-memory address */
+static unsigned long __iomem *hpwdt_timer_reg;
+static unsigned long __iomem *hpwdt_timer_con;
+
+static DEFINE_SPINLOCK(rom_lock);
+
+static void *cru_rom_addr;
+
+static struct cmn_registers cmn_regs;
+
+static struct pci_device_id hpwdt_devices[] = {
+       {
+        .vendor = PCI_VENDOR_ID_COMPAQ,
+        .device = 0xB203,
+        .subvendor = PCI_ANY_ID,
+        .subdevice = PCI_ANY_ID,
+       },
+       {0},                    /* terminate list */
+};
+MODULE_DEVICE_TABLE(pci, hpwdt_devices);
+
+/*
+ *     bios_checksum
+ */
+static int __devinit bios_checksum(const char __iomem *ptr, int len)
+{
+       char sum = 0;
+       int i;
+
+       /*
+        * calculate checksum of size bytes. This should add up
+        * to zero if we have a valid header.
+        */
+       for (i = 0; i < len; i++)
+               sum += ptr[i];
+
+       return ((sum == 0) && (len > 0));
+}
+
+#ifndef CONFIG_X86_64
+/* --32 Bit Bios------------------------------------------------------------ */
+
+#define HPWDT_ARCH     32
+
+asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
+                              unsigned long *pRomEntry)
+{
+       asm("pushl       %ebp               \n\t"
+           "movl        %esp, %ebp         \n\t"
+           "pusha                          \n\t"
+           "pushf                          \n\t"
+           "push        %es                \n\t"
+           "push        %ds                \n\t"
+           "pop         %es                \n\t"
+           "movl        8(%ebp),%eax       \n\t"
+           "movl        4(%eax),%ebx       \n\t"
+           "movl        8(%eax),%ecx       \n\t"
+           "movl        12(%eax),%edx      \n\t"
+           "movl        16(%eax),%esi      \n\t"
+           "movl        20(%eax),%edi      \n\t"
+           "movl        (%eax),%eax        \n\t"
+           "push        %cs                \n\t"
+           "call        *12(%ebp)          \n\t"
+           "pushf                          \n\t"
+           "pushl       %eax               \n\t"
+           "movl        8(%ebp),%eax       \n\t"
+           "movl        %ebx,4(%eax)       \n\t"
+           "movl        %ecx,8(%eax)       \n\t"
+           "movl        %edx,12(%eax)      \n\t"
+           "movl        %esi,16(%eax)      \n\t"
+           "movl        %edi,20(%eax)      \n\t"
+           "movw        %ds,24(%eax)       \n\t"
+           "movw        %es,26(%eax)       \n\t"
+           "popl        %ebx               \n\t"
+           "movl        %ebx,(%eax)        \n\t"
+           "popl        %ebx               \n\t"
+           "movl        %ebx,28(%eax)      \n\t"
+           "pop         %es                \n\t"
+           "popf                           \n\t"
+           "popa                           \n\t"
+           "leave                          \n\t" "ret");
+}
+
+/*
+ *     cru_detect
+ *
+ *     Routine Description:
+ *     This function uses the 32-bit BIOS Service Directory record to
+ *     search for a $CRU record.
+ *
+ *     Return Value:
+ *     0        :  SUCCESS
+ *     <0       :  FAILURE
+ */
+static int __devinit cru_detect(unsigned long map_entry,
+       unsigned long map_offset)
+{
+       void *bios32_map;
+       unsigned long *bios32_entrypoint;
+       unsigned long cru_physical_address;
+       unsigned long cru_length;
+       unsigned long physical_bios_base = 0;
+       unsigned long physical_bios_offset = 0;
+       int retval = -ENODEV;
+
+       bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
+
+       if (bios32_map == NULL)
+               return -ENODEV;
+
+       bios32_entrypoint = bios32_map + map_offset;
+
+       cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
+
+       asminline_call(&cmn_regs, bios32_entrypoint);
+
+       if (cmn_regs.u1.ral != 0) {
+               printk(KERN_WARNING
+                      "hpwdt: Call succeeded but with an error: 0x%x\n",
+                      cmn_regs.u1.ral);
+       } else {
+               physical_bios_base = cmn_regs.u2.rebx;
+               physical_bios_offset = cmn_regs.u4.redx;
+               cru_length = cmn_regs.u3.recx;
+               cru_physical_address =
+                   physical_bios_base + physical_bios_offset;
+
+               /* If the values look OK, then map it in. */
+               if ((physical_bios_base + physical_bios_offset)) {
+                       cru_rom_addr =
+                           ioremap(cru_physical_address, cru_length);
+                       if (cru_rom_addr)
+                               retval = 0;
+               }
+
+               printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
+                       physical_bios_base);
+               printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
+                       physical_bios_offset);
+               printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
+                       cru_length);
+               printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
+                       (unsigned int)&cru_rom_addr);
+       }
+       iounmap(bios32_map);
+       return retval;
+}
+
+/*
+ *     bios32_present
+ *
+ *     Routine Description:
+ *     This function finds the 32-bit BIOS Service Directory
+ *
+ *     Return Value:
+ *     0        :  SUCCESS
+ *     <0       :  FAILURE
+ */
+static int __devinit bios32_present(const char __iomem *p)
+{
+       struct bios32_service_dir *bios_32_ptr;
+       int length;
+       unsigned long map_entry, map_offset;
+
+       bios_32_ptr = (struct bios32_service_dir *) p;
+
+       /*
+        * Search for signature by checking equal to the swizzled value
+        * instead of calling another routine to perform a strcmp.
+        */
+       if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
+               length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
+               if (bios_checksum(p, length)) {
+                       /*
+                        * According to the spec, we're looking for the
+                        * first 4KB-aligned address below the entrypoint
+                        * listed in the header. The Service Directory code
+                        * is guaranteed to occupy no more than 2 4KB pages.
+                        */
+                       map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
+                       map_offset = bios_32_ptr->entry_point - map_entry;
+
+                       return cru_detect(map_entry, map_offset);
+               }
+       }
+       return -ENODEV;
+}
+
+static int __devinit detect_cru_service(void)
+{
+       char __iomem *p, *q;
+       int rc = -1;
+
+       /*
+        * Search from 0x0f0000 through 0x0fffff, inclusive.
+        */
+       p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
+       if (p == NULL)
+               return -ENOMEM;
+
+       for (q = p; q < p + ROM_SIZE; q += 16) {
+               rc = bios32_present(q);
+               if (!rc)
+                       break;
+       }
+       iounmap(p);
+       return rc;
+}
+
+#else
+/* --64 Bit Bios------------------------------------------------------------ */
+
+#define HPWDT_ARCH     64
+
+asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
+                              unsigned long *pRomEntry)
+{
+       asm("pushq      %rbp            \n\t"
+           "movq       %rsp, %rbp      \n\t"
+           "pushq      %rax            \n\t"
+           "pushq      %rbx            \n\t"
+           "pushq      %rdx            \n\t"
+           "pushq      %r12            \n\t"
+           "pushq      %r9             \n\t"
+           "movq       %rsi, %r12      \n\t"
+           "movq       %rdi, %r9       \n\t"
+           "movl       4(%r9),%ebx     \n\t"
+           "movl       8(%r9),%ecx     \n\t"
+           "movl       12(%r9),%edx    \n\t"
+           "movl       16(%r9),%esi    \n\t"
+           "movl       20(%r9),%edi    \n\t"
+           "movl       (%r9),%eax      \n\t"
+           "call       *%r12           \n\t"
+           "pushfq                     \n\t"
+           "popq        %r12           \n\t"
+           "popfq                      \n\t"
+           "movl       %eax, (%r9)     \n\t"
+           "movl       %ebx, 4(%r9)    \n\t"
+           "movl       %ecx, 8(%r9)    \n\t"
+           "movl       %edx, 12(%r9)   \n\t"
+           "movl       %esi, 16(%r9)   \n\t"
+           "movl       %edi, 20(%r9)   \n\t"
+           "movq       %r12, %rax      \n\t"
+           "movl       %eax, 28(%r9)   \n\t"
+           "popq       %r9             \n\t"
+           "popq       %r12            \n\t"
+           "popq       %rdx            \n\t"
+           "popq       %rbx            \n\t"
+           "popq       %rax            \n\t"
+           "leave                      \n\t" "ret");
+}
+
+/*
+ *     dmi_find_cru
+ *
+ *     Routine Description:
+ *     This function checks wether or not a SMBIOS/DMI record is
+ *     the 64bit CRU info or not
+ *
+ *     Return Value:
+ *     0        :  SUCCESS - if record found
+ *     <0       :  FAILURE - if record not found
+ */
+static void __devinit dmi_find_cru(const struct dmi_header *dm)
+{
+       struct smbios_cru64_info *smbios_cru64_ptr;
+       unsigned long cru_physical_address;
+
+       if (dm->type == SMBIOS_CRU64_INFORMATION) {
+               smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
+               if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
+                       cru_physical_address =
+                           smbios_cru64_ptr->physical_address +
+                           smbios_cru64_ptr->double_offset;
+                       cru_rom_addr = ioremap(cru_physical_address,
+                                   smbios_cru64_ptr->double_length);
+               }
+       }
+}
+
+/*
+ *     dmi_table
+ *
+ *     Routine Description:
+ *     Decode the SMBIOS/DMI table and check if we have a 64bit CRU record
+ *     or not.
+ *
+ *     We have to be cautious here. We have seen BIOSes with DMI pointers
+ *     pointing to completely the wrong place for example
+ */
+static void __devinit dmi_table(u8 *buf, int len, int num,
+                     void (*decode)(const struct dmi_header *))
+{
+       u8 *data = buf;
+       int i = 0;
+
+       /*
+        *      Stop when we see all the items the table claimed to have
+        *      OR we run off the end of the table (also happens)
+        */
+       while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
+               const struct dmi_header *dm = (const struct dmi_header *)data;
+
+               /*
+                *  We want to know the total length (formated area and strings)
+                *  before decoding to make sure we won't run off the table in
+                *  dmi_decode or dmi_string
+                */
+               data += dm->length;
+               while ((data - buf < len - 1) && (data[0] || data[1]))
+                       data++;
+               if (data - buf < len - 1)
+                       decode(dm);
+               data += 2;
+               i++;
+       }
+}
+
+/*
+ *     smbios_present
+ *
+ *     Routine Description:
+ *     This function parses the SMBIOS entry point table to retrieve
+ *     the 64 bit CRU Service.
+ *
+ *     Return Value:
+ *     0        :  SUCCESS
+ *     <0       :  FAILURE
+ */
+static int __devinit smbios_present(const char __iomem *p)
+{
+       struct smbios_entry_point *eps =
+               (struct smbios_entry_point *) p;
+       int length;
+       u8 *buf;
+
+       /* check if we have indeed the SMBIOS table entry point */
+       if ((strncmp((char *)eps->anchor, "_SM_",
+                            sizeof(eps->anchor))) == 0) {
+               length = eps->length;
+
+               /* SMBIOS v2.1 implementation might use 0x1e */
+               if ((length == 0x1e) &&
+                   (eps->major_ver == 2) &&
+                   (eps->minor_ver == 1))
+                       length = 0x1f;
+
+               /*
+                * Now we will check:
+                * - SMBIOS checksum must be 0
+                * - intermediate anchor should be _DMI_
+                * - intermediate checksum should be 0
+                */
+               if ((bios_checksum(p, length)) &&
+                   (strncmp((char *)eps->intermediate_anchor, "_DMI_",
+                            sizeof(eps->intermediate_anchor)) == 0) &&
+                   (bios_checksum(p+0x10, 15))) {
+                       buf = ioremap(eps->table_address, eps->table_length);
+                       if (buf == NULL)
+                               return -ENODEV;
+
+
+                       /* Scan the DMI table for the 64 bit CRU service */
+                       dmi_table(buf, eps->table_length,
+                                 eps->table_num_structs, dmi_find_cru);
+
+                       iounmap(buf);
+                       return 0;
+               }
+       }
+
+       return -ENODEV;
+}
+
+static int __devinit smbios_scan_machine(void)
+{
+       char __iomem *p, *q;
+       int rc;
+
+       if (efi_enabled) {
+               if (efi.smbios == EFI_INVALID_TABLE_ADDR)
+                       return -ENODEV;
+
+               p = ioremap(efi.smbios, 32);
+               if (p == NULL)
+                       return -ENOMEM;
+
+               rc = smbios_present(p);
+               iounmap(p);
+       } else {
+               /*
+                * Search from 0x0f0000 through 0x0fffff, inclusive.
+                */
+               p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
+               if (p == NULL)
+                       return -ENOMEM;
+
+               for (q = p; q < p + ROM_SIZE; q += 16) {
+                       rc = smbios_present(q);
+                       if (!rc) {
+                               break;
+                       }
+               }
+               iounmap(p);
+       }
+}
+
+static int __devinit detect_cru_service(void)
+{
+       cru_rom_addr = NULL;
+
+       smbios_scan_machine();  /* will become dmi_walk(dmi_find_cru); */
+
+       /* if cru_rom_addr has been set then we found a CRU service */
+       return ((cru_rom_addr != NULL)? 0: -ENODEV);
+}
+
+/* ------------------------------------------------------------------------- */
+
+#endif
+
+/*
+ *     NMI Handler
+ */
+static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
+                           void *data)
+{
+       static unsigned long rom_pl;
+       static int die_nmi_called;
+
+       if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
+               return NOTIFY_OK;
+
+       spin_lock_irqsave(&rom_lock, rom_pl);
+       if (!die_nmi_called)
+               asminline_call(&cmn_regs, cru_rom_addr);
+       die_nmi_called = 1;
+       spin_unlock_irqrestore(&rom_lock, rom_pl);
+       if (cmn_regs.u1.ral == 0) {
+               printk(KERN_WARNING "hpwdt: An NMI occurred, "
+                      "but unable to determine source.\n");
+       } else {
+               panic("An NMI occurred, please see the Integrated "
+                       "Management Log for details.\n");
+       }
+
+       return NOTIFY_STOP;
+}
+
+/*
+ *     Watchdog operations
+ */
+static void hpwdt_start(void)
+{
+       reload = (soft_margin * 1000) / 128;
+       iowrite16(reload, hpwdt_timer_reg);
+       iowrite16(0x85, hpwdt_timer_con);
+}
+
+static void hpwdt_stop(void)
+{
+       unsigned long data;
+
+       data = ioread16(hpwdt_timer_con);
+       data &= 0xFE;
+       iowrite16(data, hpwdt_timer_con);
+}
+
+static void hpwdt_ping(void)
+{
+       iowrite16(reload, hpwdt_timer_reg);
+}
+
+static int hpwdt_change_timer(int new_margin)
+{
+       /* Arbitrary, can't find the card's limits */
+       if (new_margin < 30 || new_margin > 600) {
+               printk(KERN_WARNING
+                       "hpwdt: New value passed in is invalid: %d seconds.\n",
+                       new_margin);
+               return -EINVAL;
+       }
+
+       soft_margin = new_margin;
+       printk(KERN_DEBUG
+               "hpwdt: New timer passed in is %d seconds.\n",
+               new_margin);
+       reload = (soft_margin * 1000) / 128;
+
+       return 0;
+}
+
+/*
+ *     /dev/watchdog handling
+ */
+static int hpwdt_open(struct inode *inode, struct file *file)
+{
+       /* /dev/watchdog can only be opened once */
+       if (test_and_set_bit(0, &hpwdt_is_open))
+               return -EBUSY;
+
+       /* Start the watchdog */
+       hpwdt_start();
+       hpwdt_ping();
+
+       return nonseekable_open(inode, file);
+}
+
+static int hpwdt_release(struct inode *inode, struct file *file)
+{
+       /* Stop the watchdog */
+       if (expect_release == 42) {
+               hpwdt_stop();
+       } else {
+               printk(KERN_CRIT
+                       "hpwdt: Unexpected close, not stopping watchdog!\n");
+               hpwdt_ping();
+       }
+
+       expect_release = 0;
+
+       /* /dev/watchdog is being closed, make sure it can be re-opened */
+       clear_bit(0, &hpwdt_is_open);
+
+       return 0;
+}
+
+static ssize_t hpwdt_write(struct file *file, const char __user *data,
+       size_t len, loff_t *ppos)
+{
+       /* See if we got the magic character 'V' and reload the timer */
+       if (len) {
+               if (!nowayout) {
+                       size_t i;
+
+                       /* note: just in case someone wrote the magic character
+                        * five months ago... */
+                       expect_release = 0;
+
+                       /* scan to see whether or not we got the magic char. */
+                       for (i = 0; i != len; i++) {
+                               char c;
+                               if (get_user(c, data+i))
+                                       return -EFAULT;
+                               if (c == 'V')
+                                       expect_release = 42;
+                       }
+               }
+
+               /* someone wrote to us, we should reload the timer */
+               hpwdt_ping();
+       }
+
+       return len;
+}
+
+static struct watchdog_info ident = {
+       .options = WDIOF_SETTIMEOUT |
+                  WDIOF_KEEPALIVEPING |
+                  WDIOF_MAGICCLOSE,
+       .identity = "HP iLO2 HW Watchdog Timer",
+};
+
+static long hpwdt_ioctl(struct file *file, unsigned int cmd,
+       unsigned long arg)
+{
+       void __user *argp = (void __user *)arg;
+       int __user *p = argp;
+       int new_margin;
+       int ret = -ENOTTY;
+
+       switch (cmd) {
+       case WDIOC_GETSUPPORT:
+               ret = 0;
+               if (copy_to_user(argp, &ident, sizeof(ident)))
+                       ret = -EFAULT;
+               break;
+
+       case WDIOC_GETSTATUS:
+       case WDIOC_GETBOOTSTATUS:
+               ret = put_user(0, p);
+               break;
+
+       case WDIOC_KEEPALIVE:
+               hpwdt_ping();
+               ret = 0;
+               break;
+
+       case WDIOC_SETTIMEOUT:
+               ret = get_user(new_margin, p);
+               if (ret)
+                       break;
+
+               ret = hpwdt_change_timer(new_margin);
+               if (ret)
+                       break;
+
+               hpwdt_ping();
+               /* Fall */
+       case WDIOC_GETTIMEOUT:
+               ret = put_user(soft_margin, p);
+               break;
+       }
+       return ret;
+}
+
+/*
+ *     Kernel interfaces
+ */
+static struct file_operations hpwdt_fops = {
+       .owner = THIS_MODULE,
+       .llseek = no_llseek,
+       .write = hpwdt_write,
+       .unlocked_ioctl = hpwdt_ioctl,
+       .open = hpwdt_open,
+       .release = hpwdt_release,
+};
+
+static struct miscdevice hpwdt_miscdev = {
+       .minor = WATCHDOG_MINOR,
+       .name = "watchdog",
+       .fops = &hpwdt_fops,
+};
+
+static struct notifier_block die_notifier = {
+       .notifier_call = hpwdt_pretimeout,
+       .priority = 0x7FFFFFFF,
+};
+
+/*
+ *     Init & Exit
+ */
+
+static int __devinit hpwdt_init_one(struct pci_dev *dev,
+                                   const struct pci_device_id *ent)
+{
+       int retval;
+
+       /*
+        * First let's find out if we are on an iLO2 server. We will
+        * not run on a legacy ASM box.
+        */
+       if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
+               dev_warn(&dev->dev,
+                      "This server does not have an iLO2 ASIC.\n");
+               return -ENODEV;
+       }
+
+       if (pci_enable_device(dev)) {
+               dev_warn(&dev->dev,
+                       "Not possible to enable PCI Device: 0x%x:0x%x.\n",
+                       ent->vendor, ent->device);
+               return -ENODEV;
+       }
+
+       pci_mem_addr = pci_iomap(dev, 1, 0x80);
+       if (!pci_mem_addr) {
+               dev_warn(&dev->dev,
+                       "Unable to detect the iLO2 server memory.\n");
+               retval = -ENOMEM;
+               goto error_pci_iomap;
+       }
+       hpwdt_timer_reg = pci_mem_addr + 0x70;
+       hpwdt_timer_con = pci_mem_addr + 0x72;
+
+       /* Make sure that we have a valid soft_margin */
+       if (hpwdt_change_timer(soft_margin))
+               hpwdt_change_timer(DEFAULT_MARGIN);
+
+       /*
+        * We need to map the ROM to get the CRU service.
+        * For 32 bit Operating Systems we need to go through the 32 Bit
+        * BIOS Service Directory
+        * For 64 bit Operating Systems we get that service through SMBIOS.
+        */
+       retval = detect_cru_service();
+       if (retval < 0) {
+               dev_warn(&dev->dev,
+                      "Unable to detect the %d Bit CRU Service.\n",
+                       HPWDT_ARCH);
+               goto error_get_cru;
+       }
+
+       /*
+        * We know this is the only CRU call we need to make so lets keep as
+        * few instructions as possible once the NMI comes in.
+        */
+       cmn_regs.u1.rah = 0x0D;
+       cmn_regs.u1.ral = 0x02;
+
+       retval = register_die_notifier(&die_notifier);
+       if (retval != 0) {
+               dev_warn(&dev->dev,
+                      "Unable to register a die notifier (err=%d).\n",
+                       retval);
+               goto error_die_notifier;
+       }
+
+       retval = misc_register(&hpwdt_miscdev);
+       if (retval < 0) {
+               dev_warn(&dev->dev,
+                       "Unable to register miscdev on minor=%d (err=%d).\n",
+                       WATCHDOG_MINOR, retval);
+               goto error_misc_register;
+       }
+
+       printk(KERN_INFO
+               "hp Watchdog Timer Driver: 1.00"
+               ", timer margin: %d seconds( nowayout=%d).\n",
+               soft_margin, nowayout);
+
+       return 0;
+
+error_misc_register:
+       unregister_die_notifier(&die_notifier);
+error_die_notifier:
+       if (cru_rom_addr)
+               iounmap(cru_rom_addr);
+error_get_cru:
+       pci_iounmap(dev, pci_mem_addr);
+error_pci_iomap:
+       pci_disable_device(dev);
+       return retval;
+}
+
+static void __devexit hpwdt_exit(struct pci_dev *dev)
+{
+       if (!nowayout)
+               hpwdt_stop();
+
+       misc_deregister(&hpwdt_miscdev);
+       unregister_die_notifier(&die_notifier);
+
+       if (cru_rom_addr)
+               iounmap(cru_rom_addr);
+       pci_iounmap(dev, pci_mem_addr);
+       pci_disable_device(dev);
+}
+
+static struct pci_driver hpwdt_driver = {
+       .name = "hpwdt",
+       .id_table = hpwdt_devices,
+       .probe = hpwdt_init_one,
+       .remove = __devexit_p(hpwdt_exit),
+};
+
+static void __exit hpwdt_cleanup(void)
+{
+       pci_unregister_driver(&hpwdt_driver);
+}
+
+static int __init hpwdt_init(void)
+{
+       return pci_register_driver(&hpwdt_driver);
+}
+
+MODULE_AUTHOR("Tom Mingarelli");
+MODULE_DESCRIPTION("hp watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+
+module_param(soft_margin, int, 0);
+MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+               __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+module_init(hpwdt_init);
+module_exit(hpwdt_cleanup);