Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
[linux-2.6] / drivers / watchdog / hpwdt.c
1 /*
2  *      HP WatchDog Driver
3  *      based on
4  *
5  *      SoftDog 0.05:   A Software Watchdog Device
6  *
7  *      (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
8  *      Thomas Mingarelli <thomas.mingarelli@hp.com>
9  *
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
13  *
14  */
15
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/kernel.h>
23 #include <linux/miscdevice.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/kdebug.h>
27 #include <linux/moduleparam.h>
28 #include <linux/notifier.h>
29 #include <linux/pci.h>
30 #include <linux/pci_ids.h>
31 #include <linux/reboot.h>
32 #include <linux/sched.h>
33 #include <linux/timer.h>
34 #include <linux/types.h>
35 #include <linux/uaccess.h>
36 #include <linux/watchdog.h>
37 #include <linux/dmi.h>
38 #include <linux/efi.h>
39 #include <linux/string.h>
40 #include <linux/bootmem.h>
41 #include <linux/slab.h>
42 #include <asm/desc.h>
43
44 #define PCI_BIOS32_SD_VALUE             0x5F32335F      /* "_32_" */
45 #define CRU_BIOS_SIGNATURE_VALUE        0x55524324
46 #define PCI_BIOS32_PARAGRAPH_LEN        16
47 #define PCI_ROM_BASE1                   0x000F0000
48 #define ROM_SIZE                        0x10000
49
50 struct bios32_service_dir {
51         u32 signature;
52         u32 entry_point;
53         u8 revision;
54         u8 length;
55         u8 checksum;
56         u8 reserved[5];
57 };
58
59 /* type 212 */
60 struct smbios_cru64_info {
61         u8 type;
62         u8 byte_length;
63         u16 handle;
64         u32 signature;
65         u64 physical_address;
66         u32 double_length;
67         u32 double_offset;
68 };
69 #define SMBIOS_CRU64_INFORMATION        212
70
71 struct cmn_registers {
72         union {
73                 struct {
74                         u8 ral;
75                         u8 rah;
76                         u16 rea2;
77                 };
78                 u32 reax;
79         } u1;
80         union {
81                 struct {
82                         u8 rbl;
83                         u8 rbh;
84                         u8 reb2l;
85                         u8 reb2h;
86                 };
87                 u32 rebx;
88         } u2;
89         union {
90                 struct {
91                         u8 rcl;
92                         u8 rch;
93                         u16 rec2;
94                 };
95                 u32 recx;
96         } u3;
97         union {
98                 struct {
99                         u8 rdl;
100                         u8 rdh;
101                         u16 red2;
102                 };
103                 u32 redx;
104         } u4;
105
106         u32 resi;
107         u32 redi;
108         u16 rds;
109         u16 res;
110         u32 reflags;
111 }  __attribute__((packed));
112
113 #define DEFAULT_MARGIN  30
114 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
115 static unsigned int reload;                     /* the computed soft_margin */
116 static int nowayout = WATCHDOG_NOWAYOUT;
117 static char expect_release;
118 static unsigned long hpwdt_is_open;
119
120 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
121 static unsigned long __iomem *hpwdt_timer_reg;
122 static unsigned long __iomem *hpwdt_timer_con;
123
124 static DEFINE_SPINLOCK(rom_lock);
125
126 static void *cru_rom_addr;
127
128 static struct cmn_registers cmn_regs;
129
130 static struct pci_device_id hpwdt_devices[] = {
131         {
132          .vendor = PCI_VENDOR_ID_COMPAQ,
133          .device = 0xB203,
134          .subvendor = PCI_ANY_ID,
135          .subdevice = PCI_ANY_ID,
136         },
137         {0},                    /* terminate list */
138 };
139 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
140
141 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs, unsigned long *pRomEntry);
142
143 #ifndef CONFIG_X86_64
144 /* --32 Bit Bios------------------------------------------------------------ */
145
146 #define HPWDT_ARCH      32
147
148 asm(".text                          \n\t"
149     ".align 4                       \n"
150     "asminline_call:                \n\t"
151     "pushl       %ebp               \n\t"
152     "movl        %esp, %ebp         \n\t"
153     "pusha                          \n\t"
154     "pushf                          \n\t"
155     "push        %es                \n\t"
156     "push        %ds                \n\t"
157     "pop         %es                \n\t"
158     "movl        8(%ebp),%eax       \n\t"
159     "movl        4(%eax),%ebx       \n\t"
160     "movl        8(%eax),%ecx       \n\t"
161     "movl        12(%eax),%edx      \n\t"
162     "movl        16(%eax),%esi      \n\t"
163     "movl        20(%eax),%edi      \n\t"
164     "movl        (%eax),%eax        \n\t"
165     "push        %cs                \n\t"
166     "call        *12(%ebp)          \n\t"
167     "pushf                          \n\t"
168     "pushl       %eax               \n\t"
169     "movl        8(%ebp),%eax       \n\t"
170     "movl        %ebx,4(%eax)       \n\t"
171     "movl        %ecx,8(%eax)       \n\t"
172     "movl        %edx,12(%eax)      \n\t"
173     "movl        %esi,16(%eax)      \n\t"
174     "movl        %edi,20(%eax)      \n\t"
175     "movw        %ds,24(%eax)       \n\t"
176     "movw        %es,26(%eax)       \n\t"
177     "popl        %ebx               \n\t"
178     "movl        %ebx,(%eax)        \n\t"
179     "popl        %ebx               \n\t"
180     "movl        %ebx,28(%eax)      \n\t"
181     "pop         %es                \n\t"
182     "popf                           \n\t"
183     "popa                           \n\t"
184     "leave                          \n\t"
185     "ret                            \n\t"
186     ".previous");
187
188
189 /*
190  *      cru_detect
191  *
192  *      Routine Description:
193  *      This function uses the 32-bit BIOS Service Directory record to
194  *      search for a $CRU record.
195  *
196  *      Return Value:
197  *      0        :  SUCCESS
198  *      <0       :  FAILURE
199  */
200 static int __devinit cru_detect(unsigned long map_entry,
201         unsigned long map_offset)
202 {
203         void *bios32_map;
204         unsigned long *bios32_entrypoint;
205         unsigned long cru_physical_address;
206         unsigned long cru_length;
207         unsigned long physical_bios_base = 0;
208         unsigned long physical_bios_offset = 0;
209         int retval = -ENODEV;
210
211         bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
212
213         if (bios32_map == NULL)
214                 return -ENODEV;
215
216         bios32_entrypoint = bios32_map + map_offset;
217
218         cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
219
220         asminline_call(&cmn_regs, bios32_entrypoint);
221
222         if (cmn_regs.u1.ral != 0) {
223                 printk(KERN_WARNING
224                        "hpwdt: Call succeeded but with an error: 0x%x\n",
225                        cmn_regs.u1.ral);
226         } else {
227                 physical_bios_base = cmn_regs.u2.rebx;
228                 physical_bios_offset = cmn_regs.u4.redx;
229                 cru_length = cmn_regs.u3.recx;
230                 cru_physical_address =
231                     physical_bios_base + physical_bios_offset;
232
233                 /* If the values look OK, then map it in. */
234                 if ((physical_bios_base + physical_bios_offset)) {
235                         cru_rom_addr =
236                             ioremap(cru_physical_address, cru_length);
237                         if (cru_rom_addr)
238                                 retval = 0;
239                 }
240
241                 printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
242                         physical_bios_base);
243                 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
244                         physical_bios_offset);
245                 printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
246                         cru_length);
247                 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
248                         (unsigned int)&cru_rom_addr);
249         }
250         iounmap(bios32_map);
251         return retval;
252 }
253
254 /*
255  *      bios_checksum
256  */
257 static int __devinit bios_checksum(const char __iomem *ptr, int len)
258 {
259         char sum = 0;
260         int i;
261
262         /*
263          * calculate checksum of size bytes. This should add up
264          * to zero if we have a valid header.
265          */
266         for (i = 0; i < len; i++)
267                 sum += ptr[i];
268
269         return ((sum == 0) && (len > 0));
270 }
271
272 /*
273  *      bios32_present
274  *
275  *      Routine Description:
276  *      This function finds the 32-bit BIOS Service Directory
277  *
278  *      Return Value:
279  *      0        :  SUCCESS
280  *      <0       :  FAILURE
281  */
282 static int __devinit bios32_present(const char __iomem *p)
283 {
284         struct bios32_service_dir *bios_32_ptr;
285         int length;
286         unsigned long map_entry, map_offset;
287
288         bios_32_ptr = (struct bios32_service_dir *) p;
289
290         /*
291          * Search for signature by checking equal to the swizzled value
292          * instead of calling another routine to perform a strcmp.
293          */
294         if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
295                 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
296                 if (bios_checksum(p, length)) {
297                         /*
298                          * According to the spec, we're looking for the
299                          * first 4KB-aligned address below the entrypoint
300                          * listed in the header. The Service Directory code
301                          * is guaranteed to occupy no more than 2 4KB pages.
302                          */
303                         map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
304                         map_offset = bios_32_ptr->entry_point - map_entry;
305
306                         return cru_detect(map_entry, map_offset);
307                 }
308         }
309         return -ENODEV;
310 }
311
312 static int __devinit detect_cru_service(void)
313 {
314         char __iomem *p, *q;
315         int rc = -1;
316
317         /*
318          * Search from 0x0f0000 through 0x0fffff, inclusive.
319          */
320         p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
321         if (p == NULL)
322                 return -ENOMEM;
323
324         for (q = p; q < p + ROM_SIZE; q += 16) {
325                 rc = bios32_present(q);
326                 if (!rc)
327                         break;
328         }
329         iounmap(p);
330         return rc;
331 }
332
333 #else
334 /* --64 Bit Bios------------------------------------------------------------ */
335
336 #define HPWDT_ARCH      64
337
338 asm(".text                      \n\t"
339     ".align 4                   \n"
340     "asminline_call:            \n\t"
341     "pushq      %rbp            \n\t"
342     "movq       %rsp, %rbp      \n\t"
343     "pushq      %rax            \n\t"
344     "pushq      %rbx            \n\t"
345     "pushq      %rdx            \n\t"
346     "pushq      %r12            \n\t"
347     "pushq      %r9             \n\t"
348     "movq       %rsi, %r12      \n\t"
349     "movq       %rdi, %r9       \n\t"
350     "movl       4(%r9),%ebx     \n\t"
351     "movl       8(%r9),%ecx     \n\t"
352     "movl       12(%r9),%edx    \n\t"
353     "movl       16(%r9),%esi    \n\t"
354     "movl       20(%r9),%edi    \n\t"
355     "movl       (%r9),%eax      \n\t"
356     "call       *%r12           \n\t"
357     "pushfq                     \n\t"
358     "popq        %r12           \n\t"
359     "popfq                      \n\t"
360     "movl       %eax, (%r9)     \n\t"
361     "movl       %ebx, 4(%r9)    \n\t"
362     "movl       %ecx, 8(%r9)    \n\t"
363     "movl       %edx, 12(%r9)   \n\t"
364     "movl       %esi, 16(%r9)   \n\t"
365     "movl       %edi, 20(%r9)   \n\t"
366     "movq       %r12, %rax      \n\t"
367     "movl       %eax, 28(%r9)   \n\t"
368     "popq       %r9             \n\t"
369     "popq       %r12            \n\t"
370     "popq       %rdx            \n\t"
371     "popq       %rbx            \n\t"
372     "popq       %rax            \n\t"
373     "leave                      \n\t"
374     "ret                        \n\t"
375     ".previous");
376
377 /*
378  *      dmi_find_cru
379  *
380  *      Routine Description:
381  *      This function checks whether or not a SMBIOS/DMI record is
382  *      the 64bit CRU info or not
383  */
384 static void __devinit dmi_find_cru(const struct dmi_header *dm)
385 {
386         struct smbios_cru64_info *smbios_cru64_ptr;
387         unsigned long cru_physical_address;
388
389         if (dm->type == SMBIOS_CRU64_INFORMATION) {
390                 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
391                 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
392                         cru_physical_address =
393                             smbios_cru64_ptr->physical_address +
394                             smbios_cru64_ptr->double_offset;
395                         cru_rom_addr = ioremap(cru_physical_address,
396                                     smbios_cru64_ptr->double_length);
397                 }
398         }
399 }
400
401 static int __devinit detect_cru_service(void)
402 {
403         cru_rom_addr = NULL;
404
405         dmi_walk(dmi_find_cru);
406
407         /* if cru_rom_addr has been set then we found a CRU service */
408         return ((cru_rom_addr != NULL) ? 0: -ENODEV);
409 }
410
411 /* ------------------------------------------------------------------------- */
412
413 #endif
414
415 /*
416  *      NMI Handler
417  */
418 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
419                             void *data)
420 {
421         unsigned long rom_pl;
422         static int die_nmi_called;
423
424         if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
425                 return NOTIFY_OK;
426
427         spin_lock_irqsave(&rom_lock, rom_pl);
428         if (!die_nmi_called)
429                 asminline_call(&cmn_regs, cru_rom_addr);
430         die_nmi_called = 1;
431         spin_unlock_irqrestore(&rom_lock, rom_pl);
432         if (cmn_regs.u1.ral == 0) {
433                 printk(KERN_WARNING "hpwdt: An NMI occurred, "
434                        "but unable to determine source.\n");
435         } else {
436                 panic("An NMI occurred, please see the Integrated "
437                         "Management Log for details.\n");
438         }
439
440         return NOTIFY_STOP;
441 }
442
443 /*
444  *      Watchdog operations
445  */
446 static void hpwdt_start(void)
447 {
448         reload = (soft_margin * 1000) / 128;
449         iowrite16(reload, hpwdt_timer_reg);
450         iowrite16(0x85, hpwdt_timer_con);
451 }
452
453 static void hpwdt_stop(void)
454 {
455         unsigned long data;
456
457         data = ioread16(hpwdt_timer_con);
458         data &= 0xFE;
459         iowrite16(data, hpwdt_timer_con);
460 }
461
462 static void hpwdt_ping(void)
463 {
464         iowrite16(reload, hpwdt_timer_reg);
465 }
466
467 static int hpwdt_change_timer(int new_margin)
468 {
469         /* Arbitrary, can't find the card's limits */
470         if (new_margin < 30 || new_margin > 600) {
471                 printk(KERN_WARNING
472                         "hpwdt: New value passed in is invalid: %d seconds.\n",
473                         new_margin);
474                 return -EINVAL;
475         }
476
477         soft_margin = new_margin;
478         printk(KERN_DEBUG
479                 "hpwdt: New timer passed in is %d seconds.\n",
480                 new_margin);
481         reload = (soft_margin * 1000) / 128;
482
483         return 0;
484 }
485
486 /*
487  *      /dev/watchdog handling
488  */
489 static int hpwdt_open(struct inode *inode, struct file *file)
490 {
491         /* /dev/watchdog can only be opened once */
492         if (test_and_set_bit(0, &hpwdt_is_open))
493                 return -EBUSY;
494
495         /* Start the watchdog */
496         hpwdt_start();
497         hpwdt_ping();
498
499         return nonseekable_open(inode, file);
500 }
501
502 static int hpwdt_release(struct inode *inode, struct file *file)
503 {
504         /* Stop the watchdog */
505         if (expect_release == 42) {
506                 hpwdt_stop();
507         } else {
508                 printk(KERN_CRIT
509                         "hpwdt: Unexpected close, not stopping watchdog!\n");
510                 hpwdt_ping();
511         }
512
513         expect_release = 0;
514
515         /* /dev/watchdog is being closed, make sure it can be re-opened */
516         clear_bit(0, &hpwdt_is_open);
517
518         return 0;
519 }
520
521 static ssize_t hpwdt_write(struct file *file, const char __user *data,
522         size_t len, loff_t *ppos)
523 {
524         /* See if we got the magic character 'V' and reload the timer */
525         if (len) {
526                 if (!nowayout) {
527                         size_t i;
528
529                         /* note: just in case someone wrote the magic character
530                          * five months ago... */
531                         expect_release = 0;
532
533                         /* scan to see whether or not we got the magic char. */
534                         for (i = 0; i != len; i++) {
535                                 char c;
536                                 if (get_user(c, data + i))
537                                         return -EFAULT;
538                                 if (c == 'V')
539                                         expect_release = 42;
540                         }
541                 }
542
543                 /* someone wrote to us, we should reload the timer */
544                 hpwdt_ping();
545         }
546
547         return len;
548 }
549
550 static struct watchdog_info ident = {
551         .options = WDIOF_SETTIMEOUT |
552                    WDIOF_KEEPALIVEPING |
553                    WDIOF_MAGICCLOSE,
554         .identity = "HP iLO2 HW Watchdog Timer",
555 };
556
557 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
558         unsigned long arg)
559 {
560         void __user *argp = (void __user *)arg;
561         int __user *p = argp;
562         int new_margin;
563         int ret = -ENOTTY;
564
565         switch (cmd) {
566         case WDIOC_GETSUPPORT:
567                 ret = 0;
568                 if (copy_to_user(argp, &ident, sizeof(ident)))
569                         ret = -EFAULT;
570                 break;
571
572         case WDIOC_GETSTATUS:
573         case WDIOC_GETBOOTSTATUS:
574                 ret = put_user(0, p);
575                 break;
576
577         case WDIOC_KEEPALIVE:
578                 hpwdt_ping();
579                 ret = 0;
580                 break;
581
582         case WDIOC_SETTIMEOUT:
583                 ret = get_user(new_margin, p);
584                 if (ret)
585                         break;
586
587                 ret = hpwdt_change_timer(new_margin);
588                 if (ret)
589                         break;
590
591                 hpwdt_ping();
592                 /* Fall */
593         case WDIOC_GETTIMEOUT:
594                 ret = put_user(soft_margin, p);
595                 break;
596         }
597         return ret;
598 }
599
600 /*
601  *      Kernel interfaces
602  */
603 static struct file_operations hpwdt_fops = {
604         .owner = THIS_MODULE,
605         .llseek = no_llseek,
606         .write = hpwdt_write,
607         .unlocked_ioctl = hpwdt_ioctl,
608         .open = hpwdt_open,
609         .release = hpwdt_release,
610 };
611
612 static struct miscdevice hpwdt_miscdev = {
613         .minor = WATCHDOG_MINOR,
614         .name = "watchdog",
615         .fops = &hpwdt_fops,
616 };
617
618 static struct notifier_block die_notifier = {
619         .notifier_call = hpwdt_pretimeout,
620         .priority = 0x7FFFFFFF,
621 };
622
623 /*
624  *      Init & Exit
625  */
626
627 static int __devinit hpwdt_init_one(struct pci_dev *dev,
628                                     const struct pci_device_id *ent)
629 {
630         int retval;
631
632         /*
633          * First let's find out if we are on an iLO2 server. We will
634          * not run on a legacy ASM box.
635          */
636         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
637                 dev_warn(&dev->dev,
638                        "This server does not have an iLO2 ASIC.\n");
639                 return -ENODEV;
640         }
641
642         if (pci_enable_device(dev)) {
643                 dev_warn(&dev->dev,
644                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
645                         ent->vendor, ent->device);
646                 return -ENODEV;
647         }
648
649         pci_mem_addr = pci_iomap(dev, 1, 0x80);
650         if (!pci_mem_addr) {
651                 dev_warn(&dev->dev,
652                         "Unable to detect the iLO2 server memory.\n");
653                 retval = -ENOMEM;
654                 goto error_pci_iomap;
655         }
656         hpwdt_timer_reg = pci_mem_addr + 0x70;
657         hpwdt_timer_con = pci_mem_addr + 0x72;
658
659         /* Make sure that we have a valid soft_margin */
660         if (hpwdt_change_timer(soft_margin))
661                 hpwdt_change_timer(DEFAULT_MARGIN);
662
663         /*
664          * We need to map the ROM to get the CRU service.
665          * For 32 bit Operating Systems we need to go through the 32 Bit
666          * BIOS Service Directory
667          * For 64 bit Operating Systems we get that service through SMBIOS.
668          */
669         retval = detect_cru_service();
670         if (retval < 0) {
671                 dev_warn(&dev->dev,
672                        "Unable to detect the %d Bit CRU Service.\n",
673                         HPWDT_ARCH);
674                 goto error_get_cru;
675         }
676
677         /*
678          * We know this is the only CRU call we need to make so lets keep as
679          * few instructions as possible once the NMI comes in.
680          */
681         cmn_regs.u1.rah = 0x0D;
682         cmn_regs.u1.ral = 0x02;
683
684         retval = register_die_notifier(&die_notifier);
685         if (retval != 0) {
686                 dev_warn(&dev->dev,
687                        "Unable to register a die notifier (err=%d).\n",
688                         retval);
689                 goto error_die_notifier;
690         }
691
692         retval = misc_register(&hpwdt_miscdev);
693         if (retval < 0) {
694                 dev_warn(&dev->dev,
695                         "Unable to register miscdev on minor=%d (err=%d).\n",
696                         WATCHDOG_MINOR, retval);
697                 goto error_misc_register;
698         }
699
700         printk(KERN_INFO
701                 "hp Watchdog Timer Driver: 1.00"
702                 ", timer margin: %d seconds( nowayout=%d).\n",
703                 soft_margin, nowayout);
704
705         return 0;
706
707 error_misc_register:
708         unregister_die_notifier(&die_notifier);
709 error_die_notifier:
710         if (cru_rom_addr)
711                 iounmap(cru_rom_addr);
712 error_get_cru:
713         pci_iounmap(dev, pci_mem_addr);
714 error_pci_iomap:
715         pci_disable_device(dev);
716         return retval;
717 }
718
719 static void __devexit hpwdt_exit(struct pci_dev *dev)
720 {
721         if (!nowayout)
722                 hpwdt_stop();
723
724         misc_deregister(&hpwdt_miscdev);
725         unregister_die_notifier(&die_notifier);
726
727         if (cru_rom_addr)
728                 iounmap(cru_rom_addr);
729         pci_iounmap(dev, pci_mem_addr);
730         pci_disable_device(dev);
731 }
732
733 static struct pci_driver hpwdt_driver = {
734         .name = "hpwdt",
735         .id_table = hpwdt_devices,
736         .probe = hpwdt_init_one,
737         .remove = __devexit_p(hpwdt_exit),
738 };
739
740 static void __exit hpwdt_cleanup(void)
741 {
742         pci_unregister_driver(&hpwdt_driver);
743 }
744
745 static int __init hpwdt_init(void)
746 {
747         return pci_register_driver(&hpwdt_driver);
748 }
749
750 MODULE_AUTHOR("Tom Mingarelli");
751 MODULE_DESCRIPTION("hp watchdog driver");
752 MODULE_LICENSE("GPL");
753 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
754
755 module_param(soft_margin, int, 0);
756 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
757
758 module_param(nowayout, int, 0);
759 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
760                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
761
762 module_init(hpwdt_init);
763 module_exit(hpwdt_cleanup);