Save sram context after changing MPU, DSP or core clocks
[linux-ginger.git] / drivers / watchdog / hpwdt.c
bloba6c5674c78e689414d1967d8b07fb90a28e12d3f
1 /*
2 * HP WatchDog Driver
3 * based on
5 * SoftDog 0.05: A Software Watchdog Device
7 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
8 * Thomas Mingarelli <thomas.mingarelli@hp.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * version 2 as published by the Free Software Foundation
16 #include <linux/device.h>
17 #include <linux/fs.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/irq.h>
22 #include <linux/nmi.h>
23 #include <linux/kernel.h>
24 #include <linux/miscdevice.h>
25 #include <linux/mm.h>
26 #include <linux/module.h>
27 #include <linux/kdebug.h>
28 #include <linux/moduleparam.h>
29 #include <linux/notifier.h>
30 #include <linux/pci.h>
31 #include <linux/pci_ids.h>
32 #include <linux/reboot.h>
33 #include <linux/sched.h>
34 #include <linux/timer.h>
35 #include <linux/types.h>
36 #include <linux/uaccess.h>
37 #include <linux/watchdog.h>
38 #include <linux/dmi.h>
39 #include <linux/efi.h>
40 #include <linux/string.h>
41 #include <linux/bootmem.h>
42 #include <linux/slab.h>
43 #include <asm/desc.h>
44 #include <asm/cacheflush.h>
46 #define PCI_BIOS32_SD_VALUE 0x5F32335F /* "_32_" */
47 #define CRU_BIOS_SIGNATURE_VALUE 0x55524324
48 #define PCI_BIOS32_PARAGRAPH_LEN 16
49 #define PCI_ROM_BASE1 0x000F0000
50 #define ROM_SIZE 0x10000
51 #define HPWDT_VERSION "1.1.1"
53 struct bios32_service_dir {
54 u32 signature;
55 u32 entry_point;
56 u8 revision;
57 u8 length;
58 u8 checksum;
59 u8 reserved[5];
62 /* type 212 */
63 struct smbios_cru64_info {
64 u8 type;
65 u8 byte_length;
66 u16 handle;
67 u32 signature;
68 u64 physical_address;
69 u32 double_length;
70 u32 double_offset;
72 #define SMBIOS_CRU64_INFORMATION 212
74 struct cmn_registers {
75 union {
76 struct {
77 u8 ral;
78 u8 rah;
79 u16 rea2;
81 u32 reax;
82 } u1;
83 union {
84 struct {
85 u8 rbl;
86 u8 rbh;
87 u8 reb2l;
88 u8 reb2h;
90 u32 rebx;
91 } u2;
92 union {
93 struct {
94 u8 rcl;
95 u8 rch;
96 u16 rec2;
98 u32 recx;
99 } u3;
100 union {
101 struct {
102 u8 rdl;
103 u8 rdh;
104 u16 red2;
106 u32 redx;
107 } u4;
109 u32 resi;
110 u32 redi;
111 u16 rds;
112 u16 res;
113 u32 reflags;
114 } __attribute__((packed));
116 #define DEFAULT_MARGIN 30
117 static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
118 static unsigned int reload; /* the computed soft_margin */
119 static int nowayout = WATCHDOG_NOWAYOUT;
120 static char expect_release;
121 static unsigned long hpwdt_is_open;
122 static unsigned int allow_kdump;
123 static unsigned int hpwdt_nmi_sourcing;
124 static unsigned int priority; /* hpwdt at end of die_notify list */
126 static void __iomem *pci_mem_addr; /* the PCI-memory address */
127 static unsigned long __iomem *hpwdt_timer_reg;
128 static unsigned long __iomem *hpwdt_timer_con;
130 static DEFINE_SPINLOCK(rom_lock);
132 static void *cru_rom_addr;
134 static struct cmn_registers cmn_regs;
136 static struct pci_device_id hpwdt_devices[] = {
137 { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },
138 { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },
139 {0}, /* terminate list */
141 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
143 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
144 unsigned long *pRomEntry);
146 #ifndef CONFIG_X86_64
147 /* --32 Bit Bios------------------------------------------------------------ */
149 #define HPWDT_ARCH 32
151 asm(".text \n\t"
152 ".align 4 \n"
153 "asminline_call: \n\t"
154 "pushl %ebp \n\t"
155 "movl %esp, %ebp \n\t"
156 "pusha \n\t"
157 "pushf \n\t"
158 "push %es \n\t"
159 "push %ds \n\t"
160 "pop %es \n\t"
161 "movl 8(%ebp),%eax \n\t"
162 "movl 4(%eax),%ebx \n\t"
163 "movl 8(%eax),%ecx \n\t"
164 "movl 12(%eax),%edx \n\t"
165 "movl 16(%eax),%esi \n\t"
166 "movl 20(%eax),%edi \n\t"
167 "movl (%eax),%eax \n\t"
168 "push %cs \n\t"
169 "call *12(%ebp) \n\t"
170 "pushf \n\t"
171 "pushl %eax \n\t"
172 "movl 8(%ebp),%eax \n\t"
173 "movl %ebx,4(%eax) \n\t"
174 "movl %ecx,8(%eax) \n\t"
175 "movl %edx,12(%eax) \n\t"
176 "movl %esi,16(%eax) \n\t"
177 "movl %edi,20(%eax) \n\t"
178 "movw %ds,24(%eax) \n\t"
179 "movw %es,26(%eax) \n\t"
180 "popl %ebx \n\t"
181 "movl %ebx,(%eax) \n\t"
182 "popl %ebx \n\t"
183 "movl %ebx,28(%eax) \n\t"
184 "pop %es \n\t"
185 "popf \n\t"
186 "popa \n\t"
187 "leave \n\t"
188 "ret \n\t"
189 ".previous");
193 * cru_detect
195 * Routine Description:
196 * This function uses the 32-bit BIOS Service Directory record to
197 * search for a $CRU record.
199 * Return Value:
200 * 0 : SUCCESS
201 * <0 : FAILURE
203 static int __devinit cru_detect(unsigned long map_entry,
204 unsigned long map_offset)
206 void *bios32_map;
207 unsigned long *bios32_entrypoint;
208 unsigned long cru_physical_address;
209 unsigned long cru_length;
210 unsigned long physical_bios_base = 0;
211 unsigned long physical_bios_offset = 0;
212 int retval = -ENODEV;
214 bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
216 if (bios32_map == NULL)
217 return -ENODEV;
219 bios32_entrypoint = bios32_map + map_offset;
221 cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
223 asminline_call(&cmn_regs, bios32_entrypoint);
225 if (cmn_regs.u1.ral != 0) {
226 printk(KERN_WARNING
227 "hpwdt: Call succeeded but with an error: 0x%x\n",
228 cmn_regs.u1.ral);
229 } else {
230 physical_bios_base = cmn_regs.u2.rebx;
231 physical_bios_offset = cmn_regs.u4.redx;
232 cru_length = cmn_regs.u3.recx;
233 cru_physical_address =
234 physical_bios_base + physical_bios_offset;
236 /* If the values look OK, then map it in. */
237 if ((physical_bios_base + physical_bios_offset)) {
238 cru_rom_addr =
239 ioremap(cru_physical_address, cru_length);
240 if (cru_rom_addr)
241 retval = 0;
244 printk(KERN_DEBUG "hpwdt: CRU Base Address: 0x%lx\n",
245 physical_bios_base);
246 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
247 physical_bios_offset);
248 printk(KERN_DEBUG "hpwdt: CRU Length: 0x%lx\n",
249 cru_length);
250 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
251 (unsigned int)&cru_rom_addr);
253 iounmap(bios32_map);
254 return retval;
258 * bios_checksum
260 static int __devinit bios_checksum(const char __iomem *ptr, int len)
262 char sum = 0;
263 int i;
266 * calculate checksum of size bytes. This should add up
267 * to zero if we have a valid header.
269 for (i = 0; i < len; i++)
270 sum += ptr[i];
272 return ((sum == 0) && (len > 0));
276 * bios32_present
278 * Routine Description:
279 * This function finds the 32-bit BIOS Service Directory
281 * Return Value:
282 * 0 : SUCCESS
283 * <0 : FAILURE
285 static int __devinit bios32_present(const char __iomem *p)
287 struct bios32_service_dir *bios_32_ptr;
288 int length;
289 unsigned long map_entry, map_offset;
291 bios_32_ptr = (struct bios32_service_dir *) p;
294 * Search for signature by checking equal to the swizzled value
295 * instead of calling another routine to perform a strcmp.
297 if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
298 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
299 if (bios_checksum(p, length)) {
301 * According to the spec, we're looking for the
302 * first 4KB-aligned address below the entrypoint
303 * listed in the header. The Service Directory code
304 * is guaranteed to occupy no more than 2 4KB pages.
306 map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
307 map_offset = bios_32_ptr->entry_point - map_entry;
309 return cru_detect(map_entry, map_offset);
312 return -ENODEV;
315 static int __devinit detect_cru_service(void)
317 char __iomem *p, *q;
318 int rc = -1;
321 * Search from 0x0f0000 through 0x0fffff, inclusive.
323 p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
324 if (p == NULL)
325 return -ENOMEM;
327 for (q = p; q < p + ROM_SIZE; q += 16) {
328 rc = bios32_present(q);
329 if (!rc)
330 break;
332 iounmap(p);
333 return rc;
336 #else
337 /* --64 Bit Bios------------------------------------------------------------ */
339 #define HPWDT_ARCH 64
341 asm(".text \n\t"
342 ".align 4 \n"
343 "asminline_call: \n\t"
344 "pushq %rbp \n\t"
345 "movq %rsp, %rbp \n\t"
346 "pushq %rax \n\t"
347 "pushq %rbx \n\t"
348 "pushq %rdx \n\t"
349 "pushq %r12 \n\t"
350 "pushq %r9 \n\t"
351 "movq %rsi, %r12 \n\t"
352 "movq %rdi, %r9 \n\t"
353 "movl 4(%r9),%ebx \n\t"
354 "movl 8(%r9),%ecx \n\t"
355 "movl 12(%r9),%edx \n\t"
356 "movl 16(%r9),%esi \n\t"
357 "movl 20(%r9),%edi \n\t"
358 "movl (%r9),%eax \n\t"
359 "call *%r12 \n\t"
360 "pushfq \n\t"
361 "popq %r12 \n\t"
362 "movl %eax, (%r9) \n\t"
363 "movl %ebx, 4(%r9) \n\t"
364 "movl %ecx, 8(%r9) \n\t"
365 "movl %edx, 12(%r9) \n\t"
366 "movl %esi, 16(%r9) \n\t"
367 "movl %edi, 20(%r9) \n\t"
368 "movq %r12, %rax \n\t"
369 "movl %eax, 28(%r9) \n\t"
370 "popq %r9 \n\t"
371 "popq %r12 \n\t"
372 "popq %rdx \n\t"
373 "popq %rbx \n\t"
374 "popq %rax \n\t"
375 "leave \n\t"
376 "ret \n\t"
377 ".previous");
380 * dmi_find_cru
382 * Routine Description:
383 * This function checks whether or not a SMBIOS/DMI record is
384 * the 64bit CRU info or not
386 static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
388 struct smbios_cru64_info *smbios_cru64_ptr;
389 unsigned long cru_physical_address;
391 if (dm->type == SMBIOS_CRU64_INFORMATION) {
392 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
393 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
394 cru_physical_address =
395 smbios_cru64_ptr->physical_address +
396 smbios_cru64_ptr->double_offset;
397 cru_rom_addr = ioremap(cru_physical_address,
398 smbios_cru64_ptr->double_length);
399 set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
400 smbios_cru64_ptr->double_length >> PAGE_SHIFT);
405 static int __devinit detect_cru_service(void)
407 cru_rom_addr = NULL;
409 dmi_walk(dmi_find_cru, NULL);
411 /* if cru_rom_addr has been set then we found a CRU service */
412 return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
415 /* ------------------------------------------------------------------------- */
417 #endif
420 * Watchdog operations
422 static void hpwdt_start(void)
424 reload = (soft_margin * 1000) / 128;
425 iowrite16(reload, hpwdt_timer_reg);
426 iowrite16(0x85, hpwdt_timer_con);
429 static void hpwdt_stop(void)
431 unsigned long data;
433 data = ioread16(hpwdt_timer_con);
434 data &= 0xFE;
435 iowrite16(data, hpwdt_timer_con);
438 static void hpwdt_ping(void)
440 iowrite16(reload, hpwdt_timer_reg);
443 static int hpwdt_change_timer(int new_margin)
445 /* Arbitrary, can't find the card's limits */
446 if (new_margin < 30 || new_margin > 600) {
447 printk(KERN_WARNING
448 "hpwdt: New value passed in is invalid: %d seconds.\n",
449 new_margin);
450 return -EINVAL;
453 soft_margin = new_margin;
454 printk(KERN_DEBUG
455 "hpwdt: New timer passed in is %d seconds.\n",
456 new_margin);
457 reload = (soft_margin * 1000) / 128;
459 return 0;
463 * NMI Handler
465 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
466 void *data)
468 unsigned long rom_pl;
469 static int die_nmi_called;
471 if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
472 return NOTIFY_OK;
474 if (hpwdt_nmi_sourcing) {
475 spin_lock_irqsave(&rom_lock, rom_pl);
476 if (!die_nmi_called)
477 asminline_call(&cmn_regs, cru_rom_addr);
478 die_nmi_called = 1;
479 spin_unlock_irqrestore(&rom_lock, rom_pl);
480 if (cmn_regs.u1.ral == 0) {
481 printk(KERN_WARNING "hpwdt: An NMI occurred, "
482 "but unable to determine source.\n");
483 } else {
484 if (allow_kdump)
485 hpwdt_stop();
486 panic("An NMI occurred, please see the Integrated "
487 "Management Log for details.\n");
490 return NOTIFY_OK;
494 * /dev/watchdog handling
496 static int hpwdt_open(struct inode *inode, struct file *file)
498 /* /dev/watchdog can only be opened once */
499 if (test_and_set_bit(0, &hpwdt_is_open))
500 return -EBUSY;
502 /* Start the watchdog */
503 hpwdt_start();
504 hpwdt_ping();
506 return nonseekable_open(inode, file);
509 static int hpwdt_release(struct inode *inode, struct file *file)
511 /* Stop the watchdog */
512 if (expect_release == 42) {
513 hpwdt_stop();
514 } else {
515 printk(KERN_CRIT
516 "hpwdt: Unexpected close, not stopping watchdog!\n");
517 hpwdt_ping();
520 expect_release = 0;
522 /* /dev/watchdog is being closed, make sure it can be re-opened */
523 clear_bit(0, &hpwdt_is_open);
525 return 0;
528 static ssize_t hpwdt_write(struct file *file, const char __user *data,
529 size_t len, loff_t *ppos)
531 /* See if we got the magic character 'V' and reload the timer */
532 if (len) {
533 if (!nowayout) {
534 size_t i;
536 /* note: just in case someone wrote the magic character
537 * five months ago... */
538 expect_release = 0;
540 /* scan to see whether or not we got the magic char. */
541 for (i = 0; i != len; i++) {
542 char c;
543 if (get_user(c, data + i))
544 return -EFAULT;
545 if (c == 'V')
546 expect_release = 42;
550 /* someone wrote to us, we should reload the timer */
551 hpwdt_ping();
554 return len;
557 static struct watchdog_info ident = {
558 .options = WDIOF_SETTIMEOUT |
559 WDIOF_KEEPALIVEPING |
560 WDIOF_MAGICCLOSE,
561 .identity = "HP iLO2 HW Watchdog Timer",
564 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
565 unsigned long arg)
567 void __user *argp = (void __user *)arg;
568 int __user *p = argp;
569 int new_margin;
570 int ret = -ENOTTY;
572 switch (cmd) {
573 case WDIOC_GETSUPPORT:
574 ret = 0;
575 if (copy_to_user(argp, &ident, sizeof(ident)))
576 ret = -EFAULT;
577 break;
579 case WDIOC_GETSTATUS:
580 case WDIOC_GETBOOTSTATUS:
581 ret = put_user(0, p);
582 break;
584 case WDIOC_KEEPALIVE:
585 hpwdt_ping();
586 ret = 0;
587 break;
589 case WDIOC_SETTIMEOUT:
590 ret = get_user(new_margin, p);
591 if (ret)
592 break;
594 ret = hpwdt_change_timer(new_margin);
595 if (ret)
596 break;
598 hpwdt_ping();
599 /* Fall */
600 case WDIOC_GETTIMEOUT:
601 ret = put_user(soft_margin, p);
602 break;
604 return ret;
608 * Kernel interfaces
610 static const struct file_operations hpwdt_fops = {
611 .owner = THIS_MODULE,
612 .llseek = no_llseek,
613 .write = hpwdt_write,
614 .unlocked_ioctl = hpwdt_ioctl,
615 .open = hpwdt_open,
616 .release = hpwdt_release,
619 static struct miscdevice hpwdt_miscdev = {
620 .minor = WATCHDOG_MINOR,
621 .name = "watchdog",
622 .fops = &hpwdt_fops,
625 static struct notifier_block die_notifier = {
626 .notifier_call = hpwdt_pretimeout,
627 .priority = 0,
631 * Init & Exit
634 #ifdef ARCH_HAS_NMI_WATCHDOG
635 static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
638 * If nmi_watchdog is turned off then we can turn on
639 * our nmi sourcing capability.
641 if (!nmi_watchdog_active())
642 hpwdt_nmi_sourcing = 1;
643 else
644 dev_warn(&dev->dev, "NMI sourcing is disabled. To enable this "
645 "functionality you must reboot with nmi_watchdog=0 "
646 "and load the hpwdt driver with priority=1.\n");
648 #else
649 static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
651 dev_warn(&dev->dev, "NMI sourcing is disabled. "
652 "Your kernel does not support a NMI Watchdog.\n");
654 #endif
656 static int __devinit hpwdt_init_one(struct pci_dev *dev,
657 const struct pci_device_id *ent)
659 int retval;
662 * Check if we can do NMI sourcing or not
664 hpwdt_check_nmi_sourcing(dev);
667 * First let's find out if we are on an iLO2 server. We will
668 * not run on a legacy ASM box.
669 * So we only support the G5 ProLiant servers and higher.
671 if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
672 dev_warn(&dev->dev,
673 "This server does not have an iLO2 ASIC.\n");
674 return -ENODEV;
677 if (pci_enable_device(dev)) {
678 dev_warn(&dev->dev,
679 "Not possible to enable PCI Device: 0x%x:0x%x.\n",
680 ent->vendor, ent->device);
681 return -ENODEV;
684 pci_mem_addr = pci_iomap(dev, 1, 0x80);
685 if (!pci_mem_addr) {
686 dev_warn(&dev->dev,
687 "Unable to detect the iLO2 server memory.\n");
688 retval = -ENOMEM;
689 goto error_pci_iomap;
691 hpwdt_timer_reg = pci_mem_addr + 0x70;
692 hpwdt_timer_con = pci_mem_addr + 0x72;
694 /* Make sure that we have a valid soft_margin */
695 if (hpwdt_change_timer(soft_margin))
696 hpwdt_change_timer(DEFAULT_MARGIN);
699 * We need to map the ROM to get the CRU service.
700 * For 32 bit Operating Systems we need to go through the 32 Bit
701 * BIOS Service Directory
702 * For 64 bit Operating Systems we get that service through SMBIOS.
704 retval = detect_cru_service();
705 if (retval < 0) {
706 dev_warn(&dev->dev,
707 "Unable to detect the %d Bit CRU Service.\n",
708 HPWDT_ARCH);
709 goto error_get_cru;
713 * We know this is the only CRU call we need to make so lets keep as
714 * few instructions as possible once the NMI comes in.
716 cmn_regs.u1.rah = 0x0D;
717 cmn_regs.u1.ral = 0x02;
720 * If the priority is set to 1, then we will be put first on the
721 * die notify list to handle a critical NMI. The default is to
722 * be last so other users of the NMI signal can function.
724 if (priority)
725 die_notifier.priority = 0x7FFFFFFF;
727 retval = register_die_notifier(&die_notifier);
728 if (retval != 0) {
729 dev_warn(&dev->dev,
730 "Unable to register a die notifier (err=%d).\n",
731 retval);
732 goto error_die_notifier;
735 retval = misc_register(&hpwdt_miscdev);
736 if (retval < 0) {
737 dev_warn(&dev->dev,
738 "Unable to register miscdev on minor=%d (err=%d).\n",
739 WATCHDOG_MINOR, retval);
740 goto error_misc_register;
743 printk(KERN_INFO
744 "hp Watchdog Timer Driver: %s"
745 ", timer margin: %d seconds (nowayout=%d)"
746 ", allow kernel dump: %s (default = 0/OFF)"
747 ", priority: %s (default = 0/LAST).\n",
748 HPWDT_VERSION, soft_margin, nowayout,
749 (allow_kdump == 0) ? "OFF" : "ON",
750 (priority == 0) ? "LAST" : "FIRST");
752 return 0;
754 error_misc_register:
755 unregister_die_notifier(&die_notifier);
756 error_die_notifier:
757 if (cru_rom_addr)
758 iounmap(cru_rom_addr);
759 error_get_cru:
760 pci_iounmap(dev, pci_mem_addr);
761 error_pci_iomap:
762 pci_disable_device(dev);
763 return retval;
766 static void __devexit hpwdt_exit(struct pci_dev *dev)
768 if (!nowayout)
769 hpwdt_stop();
771 misc_deregister(&hpwdt_miscdev);
772 unregister_die_notifier(&die_notifier);
774 if (cru_rom_addr)
775 iounmap(cru_rom_addr);
776 pci_iounmap(dev, pci_mem_addr);
777 pci_disable_device(dev);
780 static struct pci_driver hpwdt_driver = {
781 .name = "hpwdt",
782 .id_table = hpwdt_devices,
783 .probe = hpwdt_init_one,
784 .remove = __devexit_p(hpwdt_exit),
787 static void __exit hpwdt_cleanup(void)
789 pci_unregister_driver(&hpwdt_driver);
792 static int __init hpwdt_init(void)
794 return pci_register_driver(&hpwdt_driver);
797 MODULE_AUTHOR("Tom Mingarelli");
798 MODULE_DESCRIPTION("hp watchdog driver");
799 MODULE_LICENSE("GPL");
800 MODULE_VERSION(HPWDT_VERSION);
801 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
803 module_param(soft_margin, int, 0);
804 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
806 module_param(allow_kdump, int, 0);
807 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
809 module_param(nowayout, int, 0);
810 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
811 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
813 module_param(priority, int, 0);
814 MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
815 " (default = 0/Last)\n");
817 module_init(hpwdt_init);
818 module_exit(hpwdt_cleanup);