Linux 3.12.39

[linux/fpc-iii.git] / drivers / watchdog / hpwdt.c

/*
 *      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
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#ifdef CONFIG_HPWDT_NMI_DECODING
#include <linux/dmi.h>
#include <linux/spinlock.h>
#include <linux/nmi.h>
#include <linux/kdebug.h>
#include <linux/notifier.h>
#include <asm/cacheflush.h>
#endif /* CONFIG_HPWDT_NMI_DECODING */
#include <asm/nmi.h>

#define HPWDT_VERSION                   "1.3.2"
#define SECS_TO_TICKS(secs)             ((secs) * 1000 / 128)
#define TICKS_TO_SECS(ticks)            ((ticks) * 128 / 1000)
#define HPWDT_MAX_TIMER                 TICKS_TO_SECS(65535)
#define DEFAULT_MARGIN                  30

static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
static unsigned int reload;                     /* the computed soft_margin */
static bool 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_PCI_DEVICE_TABLE(hpwdt_devices) = {
        { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },   /* iLO2 */
        { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },       /* iLO3 */
        {0},                    /* terminate list */
};
MODULE_DEVICE_TABLE(pci, hpwdt_devices);

#ifdef CONFIG_HPWDT_NMI_DECODING
#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];
};

/* 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

/* type 219 */
struct smbios_proliant_info {
        u8 type;
        u8 byte_length;
        u16 handle;
        u32 power_features;
        u32 omega_features;
        u32 reserved;
        u32 misc_features;
};
#define SMBIOS_ICRU_INFORMATION         219


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));

static unsigned int hpwdt_nmi_decoding;
static unsigned int allow_kdump = 1;
static unsigned int is_icru;
static unsigned int is_uefi;
static DEFINE_SPINLOCK(rom_lock);
static void *cru_rom_addr;
static struct cmn_registers cmn_regs;

extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
                                                unsigned long *pRomEntry);

#ifdef CONFIG_X86_32
/* --32 Bit Bios------------------------------------------------------------ */

#define HPWDT_ARCH      32

asm(".text                          \n\t"
    ".align 4                       \n\t"
    ".globl asminline_call          \n"
    "asminline_call:                \n\t"
    "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                            \n\t"
    ".previous");


/*
 *      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 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;

        set_memory_x((unsigned long)bios32_map, 2);
        asminline_call(&cmn_regs, bios32_entrypoint);

        if (cmn_regs.u1.ral != 0) {
                pr_warn("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) {
                                set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
                                        (cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
                                retval = 0;
                        }
                }

                pr_debug("CRU Base Address:   0x%lx\n", physical_bios_base);
                pr_debug("CRU Offset Address: 0x%lx\n", physical_bios_offset);
                pr_debug("CRU Length:         0x%lx\n", cru_length);
                pr_debug("CRU Mapped Address: %p\n", &cru_rom_addr);
        }
        iounmap(bios32_map);
        return retval;
}

/*
 *      bios_checksum
 */
static int 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));
}

/*
 *      bios32_present
 *
 *      Routine Description:
 *      This function finds the 32-bit BIOS Service Directory
 *
 *      Return Value:
 *      0        :  SUCCESS
 *      <0       :  FAILURE
 */
static int 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 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;
}
/* ------------------------------------------------------------------------- */
#endif /* CONFIG_X86_32 */
#ifdef CONFIG_X86_64
/* --64 Bit Bios------------------------------------------------------------ */

#define HPWDT_ARCH      64

asm(".text                      \n\t"
    ".align 4                   \n\t"
    ".globl asminline_call      \n"
    "asminline_call:            \n\t"
    "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"
    "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                        \n\t"
    ".previous");

/*
 *      dmi_find_cru
 *
 *      Routine Description:
 *      This function checks whether or not a SMBIOS/DMI record is
 *      the 64bit CRU info or not
 */
static void dmi_find_cru(const struct dmi_header *dm, void *dummy)
{
        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);
                        set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
                                smbios_cru64_ptr->double_length >> PAGE_SHIFT);
                }
        }
}

static int detect_cru_service(void)
{
        cru_rom_addr = NULL;

        dmi_walk(dmi_find_cru, NULL);

        /* if cru_rom_addr has been set then we found a CRU service */
        return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
}
/* ------------------------------------------------------------------------- */
#endif /* CONFIG_X86_64 */
#endif /* CONFIG_HPWDT_NMI_DECODING */

/*
 *      Watchdog operations
 */
static void hpwdt_start(void)
{
        reload = SECS_TO_TICKS(soft_margin);
        iowrite16(reload, hpwdt_timer_reg);
        iowrite8(0x85, hpwdt_timer_con);
}

static void hpwdt_stop(void)
{
        unsigned long data;

        data = ioread8(hpwdt_timer_con);
        data &= 0xFE;
        iowrite8(data, hpwdt_timer_con);
}

static void hpwdt_ping(void)
{
        iowrite16(reload, hpwdt_timer_reg);
}

static int hpwdt_change_timer(int new_margin)
{
        if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
                pr_warn("New value passed in is invalid: %d seconds\n",
                        new_margin);
                return -EINVAL;
        }

        soft_margin = new_margin;
        pr_debug("New timer passed in is %d seconds\n", new_margin);
        reload = SECS_TO_TICKS(soft_margin);

        return 0;
}

static int hpwdt_time_left(void)
{
        return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
}

#ifdef CONFIG_HPWDT_NMI_DECODING
/*
 *      NMI Handler
 */
static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
{
        unsigned long rom_pl;
        static int die_nmi_called;

        if (!hpwdt_nmi_decoding)
                goto out;

        spin_lock_irqsave(&rom_lock, rom_pl);
        if (!die_nmi_called && !is_icru && !is_uefi)
                asminline_call(&cmn_regs, cru_rom_addr);
        die_nmi_called = 1;
        spin_unlock_irqrestore(&rom_lock, rom_pl);

        if (allow_kdump)
                hpwdt_stop();

        if (!is_icru && !is_uefi) {
                if (cmn_regs.u1.ral == 0) {
                        panic("An NMI occurred, "
                                "but unable to determine source.\n");
                }
        }
        panic("An NMI occurred, please see the Integrated "
                "Management Log for details.\n");

out:
        return NMI_DONE;
}
#endif /* CONFIG_HPWDT_NMI_DECODING */

/*
 *      /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 {
                pr_crit("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 const 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;

        case WDIOC_GETTIMELEFT:
                ret = put_user(hpwdt_time_left(), p);
                break;
        }
        return ret;
}

/*
 *      Kernel interfaces
 */
static const 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,
};

/*
 *      Init & Exit
 */

#ifdef CONFIG_HPWDT_NMI_DECODING
#ifdef CONFIG_X86_LOCAL_APIC
static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
{
        /*
         * If nmi_watchdog is turned off then we can turn on
         * our nmi decoding capability.
         */
        hpwdt_nmi_decoding = 1;
}
#else
static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
{
        dev_warn(&dev->dev, "NMI decoding is disabled. "
                "Your kernel does not support a NMI Watchdog.\n");
}
#endif /* CONFIG_X86_LOCAL_APIC */

/*
 *      dmi_find_icru
 *
 *      Routine Description:
 *      This function checks whether or not we are on an iCRU-based server.
 *      This check is independent of architecture and needs to be made for
 *      any ProLiant system.
 */
static void dmi_find_icru(const struct dmi_header *dm, void *dummy)
{
        struct smbios_proliant_info *smbios_proliant_ptr;

        if (dm->type == SMBIOS_ICRU_INFORMATION) {
                smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
                if (smbios_proliant_ptr->misc_features & 0x01)
                        is_icru = 1;
                if (smbios_proliant_ptr->misc_features & 0x408)
                        is_uefi = 1;
        }
}

static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
{
        int retval;

        /*
         * On typical CRU-based systems we need to map that service in
         * the BIOS. 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.
         *
         * On systems that support the new iCRU service all we need to
         * do is call dmi_walk to get the supported flag value and skip
         * the old cru detect code.
         */
        dmi_walk(dmi_find_icru, NULL);
        if (!is_icru && !is_uefi) {

                /*
                * 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);
                        return retval;
                }

                /*
                * 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;
        }

        /*
         * Only one function can register for NMI_UNKNOWN
         */
        retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
        if (retval)
                goto error;
        retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
        if (retval)
                goto error1;
        retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
        if (retval)
                goto error2;

        dev_info(&dev->dev,
                        "HP Watchdog Timer Driver: NMI decoding initialized"
                        ", allow kernel dump: %s (default = 0/OFF)\n",
                        (allow_kdump == 0) ? "OFF" : "ON");
        return 0;

error2:
        unregister_nmi_handler(NMI_SERR, "hpwdt");
error1:
        unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
error:
        dev_warn(&dev->dev,
                "Unable to register a die notifier (err=%d).\n",
                retval);
        if (cru_rom_addr)
                iounmap(cru_rom_addr);
        return retval;
}

static void hpwdt_exit_nmi_decoding(void)
{
        unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
        unregister_nmi_handler(NMI_SERR, "hpwdt");
        unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
        if (cru_rom_addr)
                iounmap(cru_rom_addr);
}
#else /* !CONFIG_HPWDT_NMI_DECODING */
static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
{
}

static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
{
        return 0;
}

static void hpwdt_exit_nmi_decoding(void)
{
}
#endif /* CONFIG_HPWDT_NMI_DECODING */

static int hpwdt_init_one(struct pci_dev *dev,
                                        const struct pci_device_id *ent)
{
        int retval;

        /*
         * Check if we can do NMI decoding or not
         */
        hpwdt_check_nmi_decoding(dev);

        /*
         * First let's find out if we are on an iLO2+ server. We will
         * not run on a legacy ASM box.
         * So we only support the G5 ProLiant servers and higher.
         */
        if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
                dev_warn(&dev->dev,
                        "This server does not have an iLO2+ ASIC.\n");
                return -ENODEV;
        }

        /*
         * Ignore all auxilary iLO devices with the following PCI ID
         */
        if (dev->subsystem_device == 0x1979)
                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 timer is disabled until /dev/watchdog is opened */
        hpwdt_stop();

        /* Make sure that we have a valid soft_margin */
        if (hpwdt_change_timer(soft_margin))
                hpwdt_change_timer(DEFAULT_MARGIN);

        /* Initialize NMI Decoding functionality */
        retval = hpwdt_init_nmi_decoding(dev);
        if (retval != 0)
                goto error_init_nmi_decoding;

        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;
        }

        dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
                        ", timer margin: %d seconds (nowayout=%d).\n",
                        HPWDT_VERSION, soft_margin, nowayout);
        return 0;

error_misc_register:
        hpwdt_exit_nmi_decoding();
error_init_nmi_decoding:
        pci_iounmap(dev, pci_mem_addr);
error_pci_iomap:
        pci_disable_device(dev);
        return retval;
}

static void hpwdt_exit(struct pci_dev *dev)
{
        if (!nowayout)
                hpwdt_stop();

        misc_deregister(&hpwdt_miscdev);
        hpwdt_exit_nmi_decoding();
        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 = hpwdt_exit,
};

MODULE_AUTHOR("Tom Mingarelli");
MODULE_DESCRIPTION("hp watchdog driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(HPWDT_VERSION);
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

module_param(soft_margin, int, 0);
MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");

module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

#ifdef CONFIG_HPWDT_NMI_DECODING
module_param(allow_kdump, int, 0);
MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
#endif /* !CONFIG_HPWDT_NMI_DECODING */

module_pci_driver(hpwdt_driver);