drivers/watchdog/hpwdt.c - kernel/msm-4.19 - Gitiles

 /*
  *	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			"1.3.0"
 #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 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 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 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"
     "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)
 		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) {
 		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;
 	}
 }

 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) {

 		/*
 		* 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;
 	}

 	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);
	/*
	* 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 "1.3.0"
	#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 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 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 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"
	"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)
	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) {
	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;
	}
	}

	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) {

	/*
	* 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;
	}

	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);