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