xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision 9c1f8594)
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/io.h>
20 #include <linux/bitops.h>
21 #include <linux/kernel.h>
22 #include <linux/miscdevice.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/pci.h>
26 #include <linux/pci_ids.h>
27 #include <linux/types.h>
28 #include <linux/uaccess.h>
29 #include <linux/watchdog.h>
30 #ifdef CONFIG_HPWDT_NMI_DECODING
31 #include <linux/dmi.h>
32 #include <linux/spinlock.h>
33 #include <linux/nmi.h>
34 #include <linux/kdebug.h>
35 #include <linux/notifier.h>
36 #include <asm/cacheflush.h>
37 #endif /* CONFIG_HPWDT_NMI_DECODING */
38 
39 #define HPWDT_VERSION			"1.3.0"
40 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
41 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
42 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(65535)
43 #define DEFAULT_MARGIN			30
44 
45 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
46 static unsigned int reload;			/* the computed soft_margin */
47 static int nowayout = WATCHDOG_NOWAYOUT;
48 static char expect_release;
49 static unsigned long hpwdt_is_open;
50 
51 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
52 static unsigned long __iomem *hpwdt_timer_reg;
53 static unsigned long __iomem *hpwdt_timer_con;
54 
55 static DEFINE_PCI_DEVICE_TABLE(hpwdt_devices) = {
56 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
57 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
58 	{0},			/* terminate list */
59 };
60 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
61 
62 #ifdef CONFIG_HPWDT_NMI_DECODING
63 #define PCI_BIOS32_SD_VALUE		0x5F32335F	/* "_32_" */
64 #define CRU_BIOS_SIGNATURE_VALUE	0x55524324
65 #define PCI_BIOS32_PARAGRAPH_LEN	16
66 #define PCI_ROM_BASE1			0x000F0000
67 #define ROM_SIZE			0x10000
68 
69 struct bios32_service_dir {
70 	u32 signature;
71 	u32 entry_point;
72 	u8 revision;
73 	u8 length;
74 	u8 checksum;
75 	u8 reserved[5];
76 };
77 
78 /* type 212 */
79 struct smbios_cru64_info {
80 	u8 type;
81 	u8 byte_length;
82 	u16 handle;
83 	u32 signature;
84 	u64 physical_address;
85 	u32 double_length;
86 	u32 double_offset;
87 };
88 #define SMBIOS_CRU64_INFORMATION	212
89 
90 /* type 219 */
91 struct smbios_proliant_info {
92 	u8 type;
93 	u8 byte_length;
94 	u16 handle;
95 	u32 power_features;
96 	u32 omega_features;
97 	u32 reserved;
98 	u32 misc_features;
99 };
100 #define SMBIOS_ICRU_INFORMATION		219
101 
102 
103 struct cmn_registers {
104 	union {
105 		struct {
106 			u8 ral;
107 			u8 rah;
108 			u16 rea2;
109 		};
110 		u32 reax;
111 	} u1;
112 	union {
113 		struct {
114 			u8 rbl;
115 			u8 rbh;
116 			u8 reb2l;
117 			u8 reb2h;
118 		};
119 		u32 rebx;
120 	} u2;
121 	union {
122 		struct {
123 			u8 rcl;
124 			u8 rch;
125 			u16 rec2;
126 		};
127 		u32 recx;
128 	} u3;
129 	union {
130 		struct {
131 			u8 rdl;
132 			u8 rdh;
133 			u16 red2;
134 		};
135 		u32 redx;
136 	} u4;
137 
138 	u32 resi;
139 	u32 redi;
140 	u16 rds;
141 	u16 res;
142 	u32 reflags;
143 }  __attribute__((packed));
144 
145 static unsigned int hpwdt_nmi_decoding;
146 static unsigned int allow_kdump;
147 static unsigned int priority;		/* hpwdt at end of die_notify list */
148 static unsigned int is_icru;
149 static DEFINE_SPINLOCK(rom_lock);
150 static void *cru_rom_addr;
151 static struct cmn_registers cmn_regs;
152 
153 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
154 						unsigned long *pRomEntry);
155 
156 #ifdef CONFIG_X86_32
157 /* --32 Bit Bios------------------------------------------------------------ */
158 
159 #define HPWDT_ARCH	32
160 
161 asm(".text                          \n\t"
162     ".align 4                       \n"
163     "asminline_call:                \n\t"
164     "pushl       %ebp               \n\t"
165     "movl        %esp, %ebp         \n\t"
166     "pusha                          \n\t"
167     "pushf                          \n\t"
168     "push        %es                \n\t"
169     "push        %ds                \n\t"
170     "pop         %es                \n\t"
171     "movl        8(%ebp),%eax       \n\t"
172     "movl        4(%eax),%ebx       \n\t"
173     "movl        8(%eax),%ecx       \n\t"
174     "movl        12(%eax),%edx      \n\t"
175     "movl        16(%eax),%esi      \n\t"
176     "movl        20(%eax),%edi      \n\t"
177     "movl        (%eax),%eax        \n\t"
178     "push        %cs                \n\t"
179     "call        *12(%ebp)          \n\t"
180     "pushf                          \n\t"
181     "pushl       %eax               \n\t"
182     "movl        8(%ebp),%eax       \n\t"
183     "movl        %ebx,4(%eax)       \n\t"
184     "movl        %ecx,8(%eax)       \n\t"
185     "movl        %edx,12(%eax)      \n\t"
186     "movl        %esi,16(%eax)      \n\t"
187     "movl        %edi,20(%eax)      \n\t"
188     "movw        %ds,24(%eax)       \n\t"
189     "movw        %es,26(%eax)       \n\t"
190     "popl        %ebx               \n\t"
191     "movl        %ebx,(%eax)        \n\t"
192     "popl        %ebx               \n\t"
193     "movl        %ebx,28(%eax)      \n\t"
194     "pop         %es                \n\t"
195     "popf                           \n\t"
196     "popa                           \n\t"
197     "leave                          \n\t"
198     "ret                            \n\t"
199     ".previous");
200 
201 
202 /*
203  *	cru_detect
204  *
205  *	Routine Description:
206  *	This function uses the 32-bit BIOS Service Directory record to
207  *	search for a $CRU record.
208  *
209  *	Return Value:
210  *	0        :  SUCCESS
211  *	<0       :  FAILURE
212  */
213 static int __devinit cru_detect(unsigned long map_entry,
214 	unsigned long map_offset)
215 {
216 	void *bios32_map;
217 	unsigned long *bios32_entrypoint;
218 	unsigned long cru_physical_address;
219 	unsigned long cru_length;
220 	unsigned long physical_bios_base = 0;
221 	unsigned long physical_bios_offset = 0;
222 	int retval = -ENODEV;
223 
224 	bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
225 
226 	if (bios32_map == NULL)
227 		return -ENODEV;
228 
229 	bios32_entrypoint = bios32_map + map_offset;
230 
231 	cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
232 
233 	asminline_call(&cmn_regs, bios32_entrypoint);
234 
235 	if (cmn_regs.u1.ral != 0) {
236 		printk(KERN_WARNING
237 			"hpwdt: Call succeeded but with an error: 0x%x\n",
238 			cmn_regs.u1.ral);
239 	} else {
240 		physical_bios_base = cmn_regs.u2.rebx;
241 		physical_bios_offset = cmn_regs.u4.redx;
242 		cru_length = cmn_regs.u3.recx;
243 		cru_physical_address =
244 			physical_bios_base + physical_bios_offset;
245 
246 		/* If the values look OK, then map it in. */
247 		if ((physical_bios_base + physical_bios_offset)) {
248 			cru_rom_addr =
249 				ioremap(cru_physical_address, cru_length);
250 			if (cru_rom_addr)
251 				retval = 0;
252 		}
253 
254 		printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
255 			physical_bios_base);
256 		printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
257 			physical_bios_offset);
258 		printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
259 			cru_length);
260 		printk(KERN_DEBUG "hpwdt: CRU Mapped Address: %p\n",
261 			&cru_rom_addr);
262 	}
263 	iounmap(bios32_map);
264 	return retval;
265 }
266 
267 /*
268  *	bios_checksum
269  */
270 static int __devinit bios_checksum(const char __iomem *ptr, int len)
271 {
272 	char sum = 0;
273 	int i;
274 
275 	/*
276 	 * calculate checksum of size bytes. This should add up
277 	 * to zero if we have a valid header.
278 	 */
279 	for (i = 0; i < len; i++)
280 		sum += ptr[i];
281 
282 	return ((sum == 0) && (len > 0));
283 }
284 
285 /*
286  *	bios32_present
287  *
288  *	Routine Description:
289  *	This function finds the 32-bit BIOS Service Directory
290  *
291  *	Return Value:
292  *	0        :  SUCCESS
293  *	<0       :  FAILURE
294  */
295 static int __devinit bios32_present(const char __iomem *p)
296 {
297 	struct bios32_service_dir *bios_32_ptr;
298 	int length;
299 	unsigned long map_entry, map_offset;
300 
301 	bios_32_ptr = (struct bios32_service_dir *) p;
302 
303 	/*
304 	 * Search for signature by checking equal to the swizzled value
305 	 * instead of calling another routine to perform a strcmp.
306 	 */
307 	if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
308 		length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
309 		if (bios_checksum(p, length)) {
310 			/*
311 			 * According to the spec, we're looking for the
312 			 * first 4KB-aligned address below the entrypoint
313 			 * listed in the header. The Service Directory code
314 			 * is guaranteed to occupy no more than 2 4KB pages.
315 			 */
316 			map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
317 			map_offset = bios_32_ptr->entry_point - map_entry;
318 
319 			return cru_detect(map_entry, map_offset);
320 		}
321 	}
322 	return -ENODEV;
323 }
324 
325 static int __devinit detect_cru_service(void)
326 {
327 	char __iomem *p, *q;
328 	int rc = -1;
329 
330 	/*
331 	 * Search from 0x0f0000 through 0x0fffff, inclusive.
332 	 */
333 	p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
334 	if (p == NULL)
335 		return -ENOMEM;
336 
337 	for (q = p; q < p + ROM_SIZE; q += 16) {
338 		rc = bios32_present(q);
339 		if (!rc)
340 			break;
341 	}
342 	iounmap(p);
343 	return rc;
344 }
345 /* ------------------------------------------------------------------------- */
346 #endif /* CONFIG_X86_32 */
347 #ifdef CONFIG_X86_64
348 /* --64 Bit Bios------------------------------------------------------------ */
349 
350 #define HPWDT_ARCH	64
351 
352 asm(".text                      \n\t"
353     ".align 4                   \n"
354     "asminline_call:            \n\t"
355     "pushq      %rbp            \n\t"
356     "movq       %rsp, %rbp      \n\t"
357     "pushq      %rax            \n\t"
358     "pushq      %rbx            \n\t"
359     "pushq      %rdx            \n\t"
360     "pushq      %r12            \n\t"
361     "pushq      %r9             \n\t"
362     "movq       %rsi, %r12      \n\t"
363     "movq       %rdi, %r9       \n\t"
364     "movl       4(%r9),%ebx     \n\t"
365     "movl       8(%r9),%ecx     \n\t"
366     "movl       12(%r9),%edx    \n\t"
367     "movl       16(%r9),%esi    \n\t"
368     "movl       20(%r9),%edi    \n\t"
369     "movl       (%r9),%eax      \n\t"
370     "call       *%r12           \n\t"
371     "pushfq                     \n\t"
372     "popq        %r12           \n\t"
373     "movl       %eax, (%r9)     \n\t"
374     "movl       %ebx, 4(%r9)    \n\t"
375     "movl       %ecx, 8(%r9)    \n\t"
376     "movl       %edx, 12(%r9)   \n\t"
377     "movl       %esi, 16(%r9)   \n\t"
378     "movl       %edi, 20(%r9)   \n\t"
379     "movq       %r12, %rax      \n\t"
380     "movl       %eax, 28(%r9)   \n\t"
381     "popq       %r9             \n\t"
382     "popq       %r12            \n\t"
383     "popq       %rdx            \n\t"
384     "popq       %rbx            \n\t"
385     "popq       %rax            \n\t"
386     "leave                      \n\t"
387     "ret                        \n\t"
388     ".previous");
389 
390 /*
391  *	dmi_find_cru
392  *
393  *	Routine Description:
394  *	This function checks whether or not a SMBIOS/DMI record is
395  *	the 64bit CRU info or not
396  */
397 static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
398 {
399 	struct smbios_cru64_info *smbios_cru64_ptr;
400 	unsigned long cru_physical_address;
401 
402 	if (dm->type == SMBIOS_CRU64_INFORMATION) {
403 		smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
404 		if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
405 			cru_physical_address =
406 				smbios_cru64_ptr->physical_address +
407 				smbios_cru64_ptr->double_offset;
408 			cru_rom_addr = ioremap(cru_physical_address,
409 				smbios_cru64_ptr->double_length);
410 			set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
411 				smbios_cru64_ptr->double_length >> PAGE_SHIFT);
412 		}
413 	}
414 }
415 
416 static int __devinit detect_cru_service(void)
417 {
418 	cru_rom_addr = NULL;
419 
420 	dmi_walk(dmi_find_cru, NULL);
421 
422 	/* if cru_rom_addr has been set then we found a CRU service */
423 	return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
424 }
425 /* ------------------------------------------------------------------------- */
426 #endif /* CONFIG_X86_64 */
427 #endif /* CONFIG_HPWDT_NMI_DECODING */
428 
429 /*
430  *	Watchdog operations
431  */
432 static void hpwdt_start(void)
433 {
434 	reload = SECS_TO_TICKS(soft_margin);
435 	iowrite16(reload, hpwdt_timer_reg);
436 	iowrite16(0x85, hpwdt_timer_con);
437 }
438 
439 static void hpwdt_stop(void)
440 {
441 	unsigned long data;
442 
443 	data = ioread16(hpwdt_timer_con);
444 	data &= 0xFE;
445 	iowrite16(data, hpwdt_timer_con);
446 }
447 
448 static void hpwdt_ping(void)
449 {
450 	iowrite16(reload, hpwdt_timer_reg);
451 }
452 
453 static int hpwdt_change_timer(int new_margin)
454 {
455 	if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
456 		printk(KERN_WARNING
457 			"hpwdt: New value passed in is invalid: %d seconds.\n",
458 			new_margin);
459 		return -EINVAL;
460 	}
461 
462 	soft_margin = new_margin;
463 	printk(KERN_DEBUG
464 		"hpwdt: New timer passed in is %d seconds.\n",
465 		new_margin);
466 	reload = SECS_TO_TICKS(soft_margin);
467 
468 	return 0;
469 }
470 
471 static int hpwdt_time_left(void)
472 {
473 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
474 }
475 
476 #ifdef CONFIG_HPWDT_NMI_DECODING
477 /*
478  *	NMI Handler
479  */
480 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
481 				void *data)
482 {
483 	unsigned long rom_pl;
484 	static int die_nmi_called;
485 
486 	if (ulReason != DIE_NMIUNKNOWN)
487 		goto out;
488 
489 	if (!hpwdt_nmi_decoding)
490 		goto out;
491 
492 	spin_lock_irqsave(&rom_lock, rom_pl);
493 	if (!die_nmi_called && !is_icru)
494 		asminline_call(&cmn_regs, cru_rom_addr);
495 	die_nmi_called = 1;
496 	spin_unlock_irqrestore(&rom_lock, rom_pl);
497 
498 	if (allow_kdump)
499 		hpwdt_stop();
500 
501 	if (!is_icru) {
502 		if (cmn_regs.u1.ral == 0) {
503 			panic("An NMI occurred, "
504 				"but unable to determine source.\n");
505 		}
506 	}
507 	panic("An NMI occurred, please see the Integrated "
508 		"Management Log for details.\n");
509 
510 out:
511 	return NOTIFY_OK;
512 }
513 #endif /* CONFIG_HPWDT_NMI_DECODING */
514 
515 /*
516  *	/dev/watchdog handling
517  */
518 static int hpwdt_open(struct inode *inode, struct file *file)
519 {
520 	/* /dev/watchdog can only be opened once */
521 	if (test_and_set_bit(0, &hpwdt_is_open))
522 		return -EBUSY;
523 
524 	/* Start the watchdog */
525 	hpwdt_start();
526 	hpwdt_ping();
527 
528 	return nonseekable_open(inode, file);
529 }
530 
531 static int hpwdt_release(struct inode *inode, struct file *file)
532 {
533 	/* Stop the watchdog */
534 	if (expect_release == 42) {
535 		hpwdt_stop();
536 	} else {
537 		printk(KERN_CRIT
538 			"hpwdt: Unexpected close, not stopping watchdog!\n");
539 		hpwdt_ping();
540 	}
541 
542 	expect_release = 0;
543 
544 	/* /dev/watchdog is being closed, make sure it can be re-opened */
545 	clear_bit(0, &hpwdt_is_open);
546 
547 	return 0;
548 }
549 
550 static ssize_t hpwdt_write(struct file *file, const char __user *data,
551 	size_t len, loff_t *ppos)
552 {
553 	/* See if we got the magic character 'V' and reload the timer */
554 	if (len) {
555 		if (!nowayout) {
556 			size_t i;
557 
558 			/* note: just in case someone wrote the magic character
559 			 * five months ago... */
560 			expect_release = 0;
561 
562 			/* scan to see whether or not we got the magic char. */
563 			for (i = 0; i != len; i++) {
564 				char c;
565 				if (get_user(c, data + i))
566 					return -EFAULT;
567 				if (c == 'V')
568 					expect_release = 42;
569 			}
570 		}
571 
572 		/* someone wrote to us, we should reload the timer */
573 		hpwdt_ping();
574 	}
575 
576 	return len;
577 }
578 
579 static const struct watchdog_info ident = {
580 	.options = WDIOF_SETTIMEOUT |
581 		   WDIOF_KEEPALIVEPING |
582 		   WDIOF_MAGICCLOSE,
583 	.identity = "HP iLO2+ HW Watchdog Timer",
584 };
585 
586 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
587 	unsigned long arg)
588 {
589 	void __user *argp = (void __user *)arg;
590 	int __user *p = argp;
591 	int new_margin;
592 	int ret = -ENOTTY;
593 
594 	switch (cmd) {
595 	case WDIOC_GETSUPPORT:
596 		ret = 0;
597 		if (copy_to_user(argp, &ident, sizeof(ident)))
598 			ret = -EFAULT;
599 		break;
600 
601 	case WDIOC_GETSTATUS:
602 	case WDIOC_GETBOOTSTATUS:
603 		ret = put_user(0, p);
604 		break;
605 
606 	case WDIOC_KEEPALIVE:
607 		hpwdt_ping();
608 		ret = 0;
609 		break;
610 
611 	case WDIOC_SETTIMEOUT:
612 		ret = get_user(new_margin, p);
613 		if (ret)
614 			break;
615 
616 		ret = hpwdt_change_timer(new_margin);
617 		if (ret)
618 			break;
619 
620 		hpwdt_ping();
621 		/* Fall */
622 	case WDIOC_GETTIMEOUT:
623 		ret = put_user(soft_margin, p);
624 		break;
625 
626 	case WDIOC_GETTIMELEFT:
627 		ret = put_user(hpwdt_time_left(), p);
628 		break;
629 	}
630 	return ret;
631 }
632 
633 /*
634  *	Kernel interfaces
635  */
636 static const struct file_operations hpwdt_fops = {
637 	.owner = THIS_MODULE,
638 	.llseek = no_llseek,
639 	.write = hpwdt_write,
640 	.unlocked_ioctl = hpwdt_ioctl,
641 	.open = hpwdt_open,
642 	.release = hpwdt_release,
643 };
644 
645 static struct miscdevice hpwdt_miscdev = {
646 	.minor = WATCHDOG_MINOR,
647 	.name = "watchdog",
648 	.fops = &hpwdt_fops,
649 };
650 
651 #ifdef CONFIG_HPWDT_NMI_DECODING
652 static struct notifier_block die_notifier = {
653 	.notifier_call = hpwdt_pretimeout,
654 	.priority = 0,
655 };
656 #endif /* CONFIG_HPWDT_NMI_DECODING */
657 
658 /*
659  *	Init & Exit
660  */
661 
662 #ifdef CONFIG_HPWDT_NMI_DECODING
663 #ifdef CONFIG_X86_LOCAL_APIC
664 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
665 {
666 	/*
667 	 * If nmi_watchdog is turned off then we can turn on
668 	 * our nmi decoding capability.
669 	 */
670 	hpwdt_nmi_decoding = 1;
671 }
672 #else
673 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
674 {
675 	dev_warn(&dev->dev, "NMI decoding is disabled. "
676 		"Your kernel does not support a NMI Watchdog.\n");
677 }
678 #endif /* CONFIG_X86_LOCAL_APIC */
679 
680 /*
681  *	dmi_find_icru
682  *
683  *	Routine Description:
684  *	This function checks whether or not we are on an iCRU-based server.
685  *	This check is independent of architecture and needs to be made for
686  *	any ProLiant system.
687  */
688 static void __devinit dmi_find_icru(const struct dmi_header *dm, void *dummy)
689 {
690 	struct smbios_proliant_info *smbios_proliant_ptr;
691 
692 	if (dm->type == SMBIOS_ICRU_INFORMATION) {
693 		smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
694 		if (smbios_proliant_ptr->misc_features & 0x01)
695 			is_icru = 1;
696 	}
697 }
698 
699 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
700 {
701 	int retval;
702 
703 	/*
704 	 * On typical CRU-based systems we need to map that service in
705 	 * the BIOS. For 32 bit Operating Systems we need to go through
706 	 * the 32 Bit BIOS Service Directory. For 64 bit Operating
707 	 * Systems we get that service through SMBIOS.
708 	 *
709 	 * On systems that support the new iCRU service all we need to
710 	 * do is call dmi_walk to get the supported flag value and skip
711 	 * the old cru detect code.
712 	 */
713 	dmi_walk(dmi_find_icru, NULL);
714 	if (!is_icru) {
715 
716 		/*
717 		* We need to map the ROM to get the CRU service.
718 		* For 32 bit Operating Systems we need to go through the 32 Bit
719 		* BIOS Service Directory
720 		* For 64 bit Operating Systems we get that service through SMBIOS.
721 		*/
722 		retval = detect_cru_service();
723 		if (retval < 0) {
724 			dev_warn(&dev->dev,
725 				"Unable to detect the %d Bit CRU Service.\n",
726 				HPWDT_ARCH);
727 			return retval;
728 		}
729 
730 		/*
731 		* We know this is the only CRU call we need to make so lets keep as
732 		* few instructions as possible once the NMI comes in.
733 		*/
734 		cmn_regs.u1.rah = 0x0D;
735 		cmn_regs.u1.ral = 0x02;
736 	}
737 
738 	/*
739 	 * If the priority is set to 1, then we will be put first on the
740 	 * die notify list to handle a critical NMI. The default is to
741 	 * be last so other users of the NMI signal can function.
742 	 */
743 	if (priority)
744 		die_notifier.priority = 0x7FFFFFFF;
745 
746 	retval = register_die_notifier(&die_notifier);
747 	if (retval != 0) {
748 		dev_warn(&dev->dev,
749 			"Unable to register a die notifier (err=%d).\n",
750 			retval);
751 		if (cru_rom_addr)
752 			iounmap(cru_rom_addr);
753 	}
754 
755 	dev_info(&dev->dev,
756 			"HP Watchdog Timer Driver: NMI decoding initialized"
757 			", allow kernel dump: %s (default = 0/OFF)"
758 			", priority: %s (default = 0/LAST).\n",
759 			(allow_kdump == 0) ? "OFF" : "ON",
760 			(priority == 0) ? "LAST" : "FIRST");
761 	return 0;
762 }
763 
764 static void hpwdt_exit_nmi_decoding(void)
765 {
766 	unregister_die_notifier(&die_notifier);
767 	if (cru_rom_addr)
768 		iounmap(cru_rom_addr);
769 }
770 #else /* !CONFIG_HPWDT_NMI_DECODING */
771 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
772 {
773 }
774 
775 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
776 {
777 	return 0;
778 }
779 
780 static void hpwdt_exit_nmi_decoding(void)
781 {
782 }
783 #endif /* CONFIG_HPWDT_NMI_DECODING */
784 
785 static int __devinit hpwdt_init_one(struct pci_dev *dev,
786 					const struct pci_device_id *ent)
787 {
788 	int retval;
789 
790 	/*
791 	 * Check if we can do NMI decoding or not
792 	 */
793 	hpwdt_check_nmi_decoding(dev);
794 
795 	/*
796 	 * First let's find out if we are on an iLO2+ server. We will
797 	 * not run on a legacy ASM box.
798 	 * So we only support the G5 ProLiant servers and higher.
799 	 */
800 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
801 		dev_warn(&dev->dev,
802 			"This server does not have an iLO2+ ASIC.\n");
803 		return -ENODEV;
804 	}
805 
806 	if (pci_enable_device(dev)) {
807 		dev_warn(&dev->dev,
808 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
809 			ent->vendor, ent->device);
810 		return -ENODEV;
811 	}
812 
813 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
814 	if (!pci_mem_addr) {
815 		dev_warn(&dev->dev,
816 			"Unable to detect the iLO2+ server memory.\n");
817 		retval = -ENOMEM;
818 		goto error_pci_iomap;
819 	}
820 	hpwdt_timer_reg = pci_mem_addr + 0x70;
821 	hpwdt_timer_con = pci_mem_addr + 0x72;
822 
823 	/* Make sure that we have a valid soft_margin */
824 	if (hpwdt_change_timer(soft_margin))
825 		hpwdt_change_timer(DEFAULT_MARGIN);
826 
827 	/* Initialize NMI Decoding functionality */
828 	retval = hpwdt_init_nmi_decoding(dev);
829 	if (retval != 0)
830 		goto error_init_nmi_decoding;
831 
832 	retval = misc_register(&hpwdt_miscdev);
833 	if (retval < 0) {
834 		dev_warn(&dev->dev,
835 			"Unable to register miscdev on minor=%d (err=%d).\n",
836 			WATCHDOG_MINOR, retval);
837 		goto error_misc_register;
838 	}
839 
840 	dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
841 			", timer margin: %d seconds (nowayout=%d).\n",
842 			HPWDT_VERSION, soft_margin, nowayout);
843 	return 0;
844 
845 error_misc_register:
846 	hpwdt_exit_nmi_decoding();
847 error_init_nmi_decoding:
848 	pci_iounmap(dev, pci_mem_addr);
849 error_pci_iomap:
850 	pci_disable_device(dev);
851 	return retval;
852 }
853 
854 static void __devexit hpwdt_exit(struct pci_dev *dev)
855 {
856 	if (!nowayout)
857 		hpwdt_stop();
858 
859 	misc_deregister(&hpwdt_miscdev);
860 	hpwdt_exit_nmi_decoding();
861 	pci_iounmap(dev, pci_mem_addr);
862 	pci_disable_device(dev);
863 }
864 
865 static struct pci_driver hpwdt_driver = {
866 	.name = "hpwdt",
867 	.id_table = hpwdt_devices,
868 	.probe = hpwdt_init_one,
869 	.remove = __devexit_p(hpwdt_exit),
870 };
871 
872 static void __exit hpwdt_cleanup(void)
873 {
874 	pci_unregister_driver(&hpwdt_driver);
875 }
876 
877 static int __init hpwdt_init(void)
878 {
879 	return pci_register_driver(&hpwdt_driver);
880 }
881 
882 MODULE_AUTHOR("Tom Mingarelli");
883 MODULE_DESCRIPTION("hp watchdog driver");
884 MODULE_LICENSE("GPL");
885 MODULE_VERSION(HPWDT_VERSION);
886 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
887 
888 module_param(soft_margin, int, 0);
889 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
890 
891 module_param(nowayout, int, 0);
892 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
893 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
894 
895 #ifdef CONFIG_HPWDT_NMI_DECODING
896 module_param(allow_kdump, int, 0);
897 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
898 
899 module_param(priority, int, 0);
900 MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
901 		" (default = 0/Last)\n");
902 #endif /* !CONFIG_HPWDT_NMI_DECODING */
903 
904 module_init(hpwdt_init);
905 module_exit(hpwdt_cleanup);
906