Merge branch 'for-2.6.26' 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/dmi.h>
43 #include <asm/desc.h>
44 #include <asm/kdebug.h>
45
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
52 struct bios32_service_dir {
53         u32 signature;
54         u32 entry_point;
55         u8 revision;
56         u8 length;
57         u8 checksum;
58         u8 reserved[5];
59 };
60
61 /* type 212 */
62 struct smbios_cru64_info {
63         u8 type;
64         u8 byte_length;
65         u16 handle;
66         u32 signature;
67         u64 physical_address;
68         u32 double_length;
69         u32 double_offset;
70 };
71 #define SMBIOS_CRU64_INFORMATION        212
72
73 struct cmn_registers {
74         union {
75                 struct {
76                         u8 ral;
77                         u8 rah;
78                         u16 rea2;
79                 };
80                 u32 reax;
81         } u1;
82         union {
83                 struct {
84                         u8 rbl;
85                         u8 rbh;
86                         u8 reb2l;
87                         u8 reb2h;
88                 };
89                 u32 rebx;
90         } u2;
91         union {
92                 struct {
93                         u8 rcl;
94                         u8 rch;
95                         u16 rec2;
96                 };
97                 u32 recx;
98         } u3;
99         union {
100                 struct {
101                         u8 rdl;
102                         u8 rdh;
103                         u16 red2;
104                 };
105                 u32 redx;
106         } u4;
107
108         u32 resi;
109         u32 redi;
110         u16 rds;
111         u16 res;
112         u32 reflags;
113 }  __attribute__((packed));
114
115 #define DEFAULT_MARGIN  30
116 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
117 static unsigned int reload;                     /* the computed soft_margin */
118 static int nowayout = WATCHDOG_NOWAYOUT;
119 static char expect_release;
120 static unsigned long hpwdt_is_open;
121
122 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
123 static unsigned long __iomem *hpwdt_timer_reg;
124 static unsigned long __iomem *hpwdt_timer_con;
125
126 static DEFINE_SPINLOCK(rom_lock);
127
128 static void *cru_rom_addr;
129
130 static struct cmn_registers cmn_regs;
131
132 static struct pci_device_id hpwdt_devices[] = {
133         {
134          .vendor = PCI_VENDOR_ID_COMPAQ,
135          .device = 0xB203,
136          .subvendor = PCI_ANY_ID,
137          .subdevice = PCI_ANY_ID,
138         },
139         {0},                    /* terminate list */
140 };
141 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
142
143 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs, unsigned long *pRomEntry);
144
145 #ifndef CONFIG_X86_64
146 /* --32 Bit Bios------------------------------------------------------------ */
147
148 #define HPWDT_ARCH      32
149
150 asm(".text                          \n\t"
151     ".align 4                       \n"
152     "asminline_call:                \n\t"
153     "pushl       %ebp               \n\t"
154     "movl        %esp, %ebp         \n\t"
155     "pusha                          \n\t"
156     "pushf                          \n\t"
157     "push        %es                \n\t"
158     "push        %ds                \n\t"
159     "pop         %es                \n\t"
160     "movl        8(%ebp),%eax       \n\t"
161     "movl        4(%eax),%ebx       \n\t"
162     "movl        8(%eax),%ecx       \n\t"
163     "movl        12(%eax),%edx      \n\t"
164     "movl        16(%eax),%esi      \n\t"
165     "movl        20(%eax),%edi      \n\t"
166     "movl        (%eax),%eax        \n\t"
167     "push        %cs                \n\t"
168     "call        *12(%ebp)          \n\t"
169     "pushf                          \n\t"
170     "pushl       %eax               \n\t"
171     "movl        8(%ebp),%eax       \n\t"
172     "movl        %ebx,4(%eax)       \n\t"
173     "movl        %ecx,8(%eax)       \n\t"
174     "movl        %edx,12(%eax)      \n\t"
175     "movl        %esi,16(%eax)      \n\t"
176     "movl        %edi,20(%eax)      \n\t"
177     "movw        %ds,24(%eax)       \n\t"
178     "movw        %es,26(%eax)       \n\t"
179     "popl        %ebx               \n\t"
180     "movl        %ebx,(%eax)        \n\t"
181     "popl        %ebx               \n\t"
182     "movl        %ebx,28(%eax)      \n\t"
183     "pop         %es                \n\t"
184     "popf                           \n\t"
185     "popa                           \n\t"
186     "leave                          \n\t"
187     "ret                            \n\t"
188     ".previous");
189
190
191 /*
192  *      cru_detect
193  *
194  *      Routine Description:
195  *      This function uses the 32-bit BIOS Service Directory record to
196  *      search for a $CRU record.
197  *
198  *      Return Value:
199  *      0        :  SUCCESS
200  *      <0       :  FAILURE
201  */
202 static int __devinit cru_detect(unsigned long map_entry,
203         unsigned long map_offset)
204 {
205         void *bios32_map;
206         unsigned long *bios32_entrypoint;
207         unsigned long cru_physical_address;
208         unsigned long cru_length;
209         unsigned long physical_bios_base = 0;
210         unsigned long physical_bios_offset = 0;
211         int retval = -ENODEV;
212
213         bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
214
215         if (bios32_map == NULL)
216                 return -ENODEV;
217
218         bios32_entrypoint = bios32_map + map_offset;
219
220         cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
221
222         asminline_call(&cmn_regs, bios32_entrypoint);
223
224         if (cmn_regs.u1.ral != 0) {
225                 printk(KERN_WARNING
226                        "hpwdt: Call succeeded but with an error: 0x%x\n",
227                        cmn_regs.u1.ral);
228         } else {
229                 physical_bios_base = cmn_regs.u2.rebx;
230                 physical_bios_offset = cmn_regs.u4.redx;
231                 cru_length = cmn_regs.u3.recx;
232                 cru_physical_address =
233                     physical_bios_base + physical_bios_offset;
234
235                 /* If the values look OK, then map it in. */
236                 if ((physical_bios_base + physical_bios_offset)) {
237                         cru_rom_addr =
238                             ioremap(cru_physical_address, cru_length);
239                         if (cru_rom_addr)
240                                 retval = 0;
241                 }
242
243                 printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
244                         physical_bios_base);
245                 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
246                         physical_bios_offset);
247                 printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
248                         cru_length);
249                 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
250                         (unsigned int)&cru_rom_addr);
251         }
252         iounmap(bios32_map);
253         return retval;
254 }
255
256 /*
257  *      bios_checksum
258  */
259 static int __devinit bios_checksum(const char __iomem *ptr, int len)
260 {
261         char sum = 0;
262         int i;
263
264         /*
265          * calculate checksum of size bytes. This should add up
266          * to zero if we have a valid header.
267          */
268         for (i = 0; i < len; i++)
269                 sum += ptr[i];
270
271         return ((sum == 0) && (len > 0));
272 }
273
274 /*
275  *      bios32_present
276  *
277  *      Routine Description:
278  *      This function finds the 32-bit BIOS Service Directory
279  *
280  *      Return Value:
281  *      0        :  SUCCESS
282  *      <0       :  FAILURE
283  */
284 static int __devinit bios32_present(const char __iomem *p)
285 {
286         struct bios32_service_dir *bios_32_ptr;
287         int length;
288         unsigned long map_entry, map_offset;
289
290         bios_32_ptr = (struct bios32_service_dir *) p;
291
292         /*
293          * Search for signature by checking equal to the swizzled value
294          * instead of calling another routine to perform a strcmp.
295          */
296         if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
297                 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
298                 if (bios_checksum(p, length)) {
299                         /*
300                          * According to the spec, we're looking for the
301                          * first 4KB-aligned address below the entrypoint
302                          * listed in the header. The Service Directory code
303                          * is guaranteed to occupy no more than 2 4KB pages.
304                          */
305                         map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
306                         map_offset = bios_32_ptr->entry_point - map_entry;
307
308                         return cru_detect(map_entry, map_offset);
309                 }
310         }
311         return -ENODEV;
312 }
313
314 static int __devinit detect_cru_service(void)
315 {
316         char __iomem *p, *q;
317         int rc = -1;
318
319         /*
320          * Search from 0x0f0000 through 0x0fffff, inclusive.
321          */
322         p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
323         if (p == NULL)
324                 return -ENOMEM;
325
326         for (q = p; q < p + ROM_SIZE; q += 16) {
327                 rc = bios32_present(q);
328                 if (!rc)
329                         break;
330         }
331         iounmap(p);
332         return rc;
333 }
334
335 #else
336 /* --64 Bit Bios------------------------------------------------------------ */
337
338 #define HPWDT_ARCH      64
339
340 asm(".text                      \n\t"
341     ".align 4                   \n"
342     "asminline_call:            \n\t"
343     "pushq      %rbp            \n\t"
344     "movq       %rsp, %rbp      \n\t"
345     "pushq      %rax            \n\t"
346     "pushq      %rbx            \n\t"
347     "pushq      %rdx            \n\t"
348     "pushq      %r12            \n\t"
349     "pushq      %r9             \n\t"
350     "movq       %rsi, %r12      \n\t"
351     "movq       %rdi, %r9       \n\t"
352     "movl       4(%r9),%ebx     \n\t"
353     "movl       8(%r9),%ecx     \n\t"
354     "movl       12(%r9),%edx    \n\t"
355     "movl       16(%r9),%esi    \n\t"
356     "movl       20(%r9),%edi    \n\t"
357     "movl       (%r9),%eax      \n\t"
358     "call       *%r12           \n\t"
359     "pushfq                     \n\t"
360     "popq        %r12           \n\t"
361     "popfq                      \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");
378
379 /*
380  *      dmi_find_cru
381  *
382  *      Routine Description:
383  *      This function checks whether or not a SMBIOS/DMI record is
384  *      the 64bit CRU info or not
385  */
386 static void __devinit dmi_find_cru(const struct dmi_header *dm)
387 {
388         struct smbios_cru64_info *smbios_cru64_ptr;
389         unsigned long cru_physical_address;
390
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                 }
400         }
401 }
402
403 static int __devinit detect_cru_service(void)
404 {
405         cru_rom_addr = NULL;
406
407         dmi_walk(dmi_find_cru);
408
409         /* if cru_rom_addr has been set then we found a CRU service */
410         return ((cru_rom_addr != NULL)? 0: -ENODEV);
411 }
412
413 /* ------------------------------------------------------------------------- */
414
415 #endif
416
417 /*
418  *      NMI Handler
419  */
420 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
421                             void *data)
422 {
423         static unsigned long rom_pl;
424         static int die_nmi_called;
425
426         if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
427                 return NOTIFY_OK;
428
429         spin_lock_irqsave(&rom_lock, rom_pl);
430         if (!die_nmi_called)
431                 asminline_call(&cmn_regs, cru_rom_addr);
432         die_nmi_called = 1;
433         spin_unlock_irqrestore(&rom_lock, rom_pl);
434         if (cmn_regs.u1.ral == 0) {
435                 printk(KERN_WARNING "hpwdt: An NMI occurred, "
436                        "but unable to determine source.\n");
437         } else {
438                 panic("An NMI occurred, please see the Integrated "
439                         "Management Log for details.\n");
440         }
441
442         return NOTIFY_STOP;
443 }
444
445 /*
446  *      Watchdog operations
447  */
448 static void hpwdt_start(void)
449 {
450         reload = (soft_margin * 1000) / 128;
451         iowrite16(reload, hpwdt_timer_reg);
452         iowrite16(0x85, hpwdt_timer_con);
453 }
454
455 static void hpwdt_stop(void)
456 {
457         unsigned long data;
458
459         data = ioread16(hpwdt_timer_con);
460         data &= 0xFE;
461         iowrite16(data, hpwdt_timer_con);
462 }
463
464 static void hpwdt_ping(void)
465 {
466         iowrite16(reload, hpwdt_timer_reg);
467 }
468
469 static int hpwdt_change_timer(int new_margin)
470 {
471         /* Arbitrary, can't find the card's limits */
472         if (new_margin < 30 || new_margin > 600) {
473                 printk(KERN_WARNING
474                         "hpwdt: New value passed in is invalid: %d seconds.\n",
475                         new_margin);
476                 return -EINVAL;
477         }
478
479         soft_margin = new_margin;
480         printk(KERN_DEBUG
481                 "hpwdt: New timer passed in is %d seconds.\n",
482                 new_margin);
483         reload = (soft_margin * 1000) / 128;
484
485         return 0;
486 }
487
488 /*
489  *      /dev/watchdog handling
490  */
491 static int hpwdt_open(struct inode *inode, struct file *file)
492 {
493         /* /dev/watchdog can only be opened once */
494         if (test_and_set_bit(0, &hpwdt_is_open))
495                 return -EBUSY;
496
497         /* Start the watchdog */
498         hpwdt_start();
499         hpwdt_ping();
500
501         return nonseekable_open(inode, file);
502 }
503
504 static int hpwdt_release(struct inode *inode, struct file *file)
505 {
506         /* Stop the watchdog */
507         if (expect_release == 42) {
508                 hpwdt_stop();
509         } else {
510                 printk(KERN_CRIT
511                         "hpwdt: Unexpected close, not stopping watchdog!\n");
512                 hpwdt_ping();
513         }
514
515         expect_release = 0;
516
517         /* /dev/watchdog is being closed, make sure it can be re-opened */
518         clear_bit(0, &hpwdt_is_open);
519
520         return 0;
521 }
522
523 static ssize_t hpwdt_write(struct file *file, const char __user *data,
524         size_t len, loff_t *ppos)
525 {
526         /* See if we got the magic character 'V' and reload the timer */
527         if (len) {
528                 if (!nowayout) {
529                         size_t i;
530
531                         /* note: just in case someone wrote the magic character
532                          * five months ago... */
533                         expect_release = 0;
534
535                         /* scan to see whether or not we got the magic char. */
536                         for (i = 0; i != len; i++) {
537                                 char c;
538                                 if (get_user(c, data+i))
539                                         return -EFAULT;
540                                 if (c == 'V')
541                                         expect_release = 42;
542                         }
543                 }
544
545                 /* someone wrote to us, we should reload the timer */
546                 hpwdt_ping();
547         }
548
549         return len;
550 }
551
552 static struct watchdog_info ident = {
553         .options = WDIOF_SETTIMEOUT |
554                    WDIOF_KEEPALIVEPING |
555                    WDIOF_MAGICCLOSE,
556         .identity = "HP iLO2 HW Watchdog Timer",
557 };
558
559 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
560         unsigned long arg)
561 {
562         void __user *argp = (void __user *)arg;
563         int __user *p = argp;
564         int new_margin;
565         int ret = -ENOTTY;
566
567         switch (cmd) {
568         case WDIOC_GETSUPPORT:
569                 ret = 0;
570                 if (copy_to_user(argp, &ident, sizeof(ident)))
571                         ret = -EFAULT;
572                 break;
573
574         case WDIOC_GETSTATUS:
575         case WDIOC_GETBOOTSTATUS:
576                 ret = put_user(0, p);
577                 break;
578
579         case WDIOC_KEEPALIVE:
580                 hpwdt_ping();
581                 ret = 0;
582                 break;
583
584         case WDIOC_SETTIMEOUT:
585                 ret = get_user(new_margin, p);
586                 if (ret)
587                         break;
588
589                 ret = hpwdt_change_timer(new_margin);
590                 if (ret)
591                         break;
592
593                 hpwdt_ping();
594                 /* Fall */
595         case WDIOC_GETTIMEOUT:
596                 ret = put_user(soft_margin, p);
597                 break;
598         }
599         return ret;
600 }
601
602 /*
603  *      Kernel interfaces
604  */
605 static struct file_operations hpwdt_fops = {
606         .owner = THIS_MODULE,
607         .llseek = no_llseek,
608         .write = hpwdt_write,
609         .unlocked_ioctl = hpwdt_ioctl,
610         .open = hpwdt_open,
611         .release = hpwdt_release,
612 };
613
614 static struct miscdevice hpwdt_miscdev = {
615         .minor = WATCHDOG_MINOR,
616         .name = "watchdog",
617         .fops = &hpwdt_fops,
618 };
619
620 static struct notifier_block die_notifier = {
621         .notifier_call = hpwdt_pretimeout,
622         .priority = 0x7FFFFFFF,
623 };
624
625 /*
626  *      Init & Exit
627  */
628
629 static int __devinit hpwdt_init_one(struct pci_dev *dev,
630                                     const struct pci_device_id *ent)
631 {
632         int retval;
633
634         /*
635          * First let's find out if we are on an iLO2 server. We will
636          * not run on a legacy ASM box.
637          */
638         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
639                 dev_warn(&dev->dev,
640                        "This server does not have an iLO2 ASIC.\n");
641                 return -ENODEV;
642         }
643
644         if (pci_enable_device(dev)) {
645                 dev_warn(&dev->dev,
646                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
647                         ent->vendor, ent->device);
648                 return -ENODEV;
649         }
650
651         pci_mem_addr = pci_iomap(dev, 1, 0x80);
652         if (!pci_mem_addr) {
653                 dev_warn(&dev->dev,
654                         "Unable to detect the iLO2 server memory.\n");
655                 retval = -ENOMEM;
656                 goto error_pci_iomap;
657         }
658         hpwdt_timer_reg = pci_mem_addr + 0x70;
659         hpwdt_timer_con = pci_mem_addr + 0x72;
660
661         /* Make sure that we have a valid soft_margin */
662         if (hpwdt_change_timer(soft_margin))
663                 hpwdt_change_timer(DEFAULT_MARGIN);
664
665         /*
666          * We need to map the ROM to get the CRU service.
667          * For 32 bit Operating Systems we need to go through the 32 Bit
668          * BIOS Service Directory
669          * For 64 bit Operating Systems we get that service through SMBIOS.
670          */
671         retval = detect_cru_service();
672         if (retval < 0) {
673                 dev_warn(&dev->dev,
674                        "Unable to detect the %d Bit CRU Service.\n",
675                         HPWDT_ARCH);
676                 goto error_get_cru;
677         }
678
679         /*
680          * We know this is the only CRU call we need to make so lets keep as
681          * few instructions as possible once the NMI comes in.
682          */
683         cmn_regs.u1.rah = 0x0D;
684         cmn_regs.u1.ral = 0x02;
685
686         retval = register_die_notifier(&die_notifier);
687         if (retval != 0) {
688                 dev_warn(&dev->dev,
689                        "Unable to register a die notifier (err=%d).\n",
690                         retval);
691                 goto error_die_notifier;
692         }
693
694         retval = misc_register(&hpwdt_miscdev);
695         if (retval < 0) {
696                 dev_warn(&dev->dev,
697                         "Unable to register miscdev on minor=%d (err=%d).\n",
698                         WATCHDOG_MINOR, retval);
699                 goto error_misc_register;
700         }
701
702         printk(KERN_INFO
703                 "hp Watchdog Timer Driver: 1.00"
704                 ", timer margin: %d seconds( nowayout=%d).\n",
705                 soft_margin, nowayout);
706
707         return 0;
708
709 error_misc_register:
710         unregister_die_notifier(&die_notifier);
711 error_die_notifier:
712         if (cru_rom_addr)
713                 iounmap(cru_rom_addr);
714 error_get_cru:
715         pci_iounmap(dev, pci_mem_addr);
716 error_pci_iomap:
717         pci_disable_device(dev);
718         return retval;
719 }
720
721 static void __devexit hpwdt_exit(struct pci_dev *dev)
722 {
723         if (!nowayout)
724                 hpwdt_stop();
725
726         misc_deregister(&hpwdt_miscdev);
727         unregister_die_notifier(&die_notifier);
728
729         if (cru_rom_addr)
730                 iounmap(cru_rom_addr);
731         pci_iounmap(dev, pci_mem_addr);
732         pci_disable_device(dev);
733 }
734
735 static struct pci_driver hpwdt_driver = {
736         .name = "hpwdt",
737         .id_table = hpwdt_devices,
738         .probe = hpwdt_init_one,
739         .remove = __devexit_p(hpwdt_exit),
740 };
741
742 static void __exit hpwdt_cleanup(void)
743 {
744         pci_unregister_driver(&hpwdt_driver);
745 }
746
747 static int __init hpwdt_init(void)
748 {
749         return pci_register_driver(&hpwdt_driver);
750 }
751
752 MODULE_AUTHOR("Tom Mingarelli");
753 MODULE_DESCRIPTION("hp watchdog driver");
754 MODULE_LICENSE("GPL");
755 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
756
757 module_param(soft_margin, int, 0);
758 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
759
760 module_param(nowayout, int, 0);
761 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
762                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
763
764 module_init(hpwdt_init);
765 module_exit(hpwdt_cleanup);