[WATCHDOG] HP ProLiant WatchDog driver

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>

3 files changed, 939 insertions, 0 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 591e3f39911..254d115cafa 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -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
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 90e4bbffbbf..f3fb170fe5c 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -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
index 00000000000..a2e174b09fe
--- /dev/null
+++ b/drivers/watchdog/hpwdt.c
@@ -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);