- 根目录:
- 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
*
*/
#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 */
#define HPWDT_VERSION "1.2.0"
#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 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_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
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;
static unsigned int priority; /* hpwdt at end of die_notify list */
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"
"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 __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;
set_memory_x((unsigned long)bios32_map, 2);
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) {
set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
(cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
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: %p\n",
&cru_rom_addr);
}
iounmap(bios32_map);
return retval;
}
/*
* 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));
}
/*
* 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;
}
/* ------------------------------------------------------------------------- */
#endif /* CONFIG_X86_32 */
#ifdef CONFIG_X86_64
/* --64 Bit Bios------------------------------------------------------------ */
#define HPWDT_ARCH 64
asm(".text \n\t"
".align 4 \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 __devinit 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 __devinit 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);
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)
{
if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
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 = 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(struct notifier_block *nb, unsigned long ulReason,
void *data)
{
unsigned long rom_pl;
static int die_nmi_called;
if (ulReason != DIE_NMIUNKNOWN)
goto out;
if (!hpwdt_nmi_decoding)
goto out;
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 {
if (allow_kdump)
hpwdt_stop();
panic("An NMI occurred, please see the Integrated "
"Management Log for details.\n");
}
out:
return NOTIFY_OK;
}
#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 {
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 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,
};
#ifdef CONFIG_HPWDT_NMI_DECODING
static struct notifier_block die_notifier = {
.notifier_call = hpwdt_pretimeout,
.priority = 0,
};
#endif /* CONFIG_HPWDT_NMI_DECODING */
/*
* Init & Exit
*/
#ifdef CONFIG_HPWDT_NMI_DECODING
#ifdef CONFIG_X86_LOCAL_APIC
static void __devinit 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 __devinit 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 */
static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
{
int retval;
/*
* 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;
/*
* If the priority is set to 1, then we will be put first on the
* die notify list to handle a critical NMI. The default is to
* be last so other users of the NMI signal can function.
*/
if (priority)
die_notifier.priority = 0x7FFFFFFF;
retval = register_die_notifier(&die_notifier);
if (retval != 0) {
dev_warn(&dev->dev,
"Unable to register a die notifier (err=%d).\n",
retval);
if (cru_rom_addr)
iounmap(cru_rom_addr);
}
dev_info(&dev->dev,
"HP Watchdog Timer Driver: NMI decoding initialized"
", allow kernel dump: %s (default = 0/OFF)"
", priority: %s (default = 0/LAST).\n",
(allow_kdump == 0) ? "OFF" : "ON",
(priority == 0) ? "LAST" : "FIRST");
return 0;
}
static void hpwdt_exit_nmi_decoding(void)
{
unregister_die_notifier(&die_notifier);
if (cru_rom_addr)
iounmap(cru_rom_addr);
}
#else /* !CONFIG_HPWDT_NMI_DECODING */
static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
{
}
static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
{
return 0;
}
static void hpwdt_exit_nmi_decoding(void)
{
}
#endif /* CONFIG_HPWDT_NMI_DECODING */
static int __devinit 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;
}
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 __devexit 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 = __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_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, int, 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");
module_param(priority, int, 0);
MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
" (default = 0/Last)\n");
#endif /* !CONFIG_HPWDT_NMI_DECODING */
module_init(hpwdt_init);
module_exit(hpwdt_cleanup);