Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
/*
 *	HP WatchDog Driver
 *	based on
 *
 *	SoftDog	0.05:	A Software Watchdog Device
 *
 *	(c) Copyright 2007 Hewlett-Packard Development Company, L.P.
 *	Thomas Mingarelli <thomas.mingarelli@hp.com>
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	version 2 as published by the Free Software Foundation
 *
 */

#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/nmi.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/kdebug.h>
#include <linux/moduleparam.h>
#include <linux/notifier.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/string.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <asm/desc.h>
#include <asm/cacheflush.h>

#define PCI_BIOS32_SD_VALUE		0x5F32335F	/* "_32_" */
#define CRU_BIOS_SIGNATURE_VALUE	0x55524324
#define PCI_BIOS32_PARAGRAPH_LEN	16
#define PCI_ROM_BASE1			0x000F0000
#define ROM_SIZE			0x10000
#define HPWDT_VERSION			"1.1.1"

struct bios32_service_dir {
	u32 signature;
	u32 entry_point;
	u8 revision;
	u8 length;
	u8 checksum;
	u8 reserved[5];
};

/* type 212 */
struct smbios_cru64_info {
	u8 type;
	u8 byte_length;
	u16 handle;
	u32 signature;
	u64 physical_address;
	u32 double_length;
	u32 double_offset;
};
#define SMBIOS_CRU64_INFORMATION	212

struct cmn_registers {
	union {
		struct {
			u8 ral;
			u8 rah;
			u16 rea2;
		};
		u32 reax;
	} u1;
	union {
		struct {
			u8 rbl;
			u8 rbh;
			u8 reb2l;
			u8 reb2h;
		};
		u32 rebx;
	} u2;
	union {
		struct {
			u8 rcl;
			u8 rch;
			u16 rec2;
		};
		u32 recx;
	} u3;
	union {
		struct {
			u8 rdl;
			u8 rdh;
			u16 red2;
		};
		u32 redx;
	} u4;

	u32 resi;
	u32 redi;
	u16 rds;
	u16 res;
	u32 reflags;
}  __attribute__((packed));

#define DEFAULT_MARGIN	30
static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
static unsigned int reload;			/* the computed soft_margin */
static int nowayout = WATCHDOG_NOWAYOUT;
static char expect_release;
static unsigned long hpwdt_is_open;
static unsigned int allow_kdump;
static unsigned int hpwdt_nmi_sourcing;
static unsigned int priority;		/* hpwdt at end of die_notify list */

static void __iomem *pci_mem_addr;		/* the PCI-memory address */
static unsigned long __iomem *hpwdt_timer_reg;
static unsigned long __iomem *hpwdt_timer_con;

static DEFINE_SPINLOCK(rom_lock);

static void *cru_rom_addr;

static struct cmn_registers cmn_regs;

static struct pci_device_id hpwdt_devices[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },
	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },
	{0},			/* terminate list */
};
MODULE_DEVICE_TABLE(pci, hpwdt_devices);

extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
						unsigned long *pRomEntry);

#ifndef CONFIG_X86_64
/* --32 Bit Bios------------------------------------------------------------ */

#define HPWDT_ARCH	32

asm(".text                          \n\t"
    ".align 4                       \n"
    "asminline_call:                \n\t"
    "pushl       %ebp               \n\t"
    "movl        %esp, %ebp         \n\t"
    "pusha                          \n\t"
    "pushf                          \n\t"
    "push        %es                \n\t"
    "push        %ds                \n\t"
    "pop         %es                \n\t"
    "movl        8(%ebp),%eax       \n\t"
    "movl        4(%eax),%ebx       \n\t"
    "movl        8(%eax),%ecx       \n\t"
    "movl        12(%eax),%edx      \n\t"
    "movl        16(%eax),%esi      \n\t"
    "movl        20(%eax),%edi      \n\t"
    "movl        (%eax),%eax        \n\t"
    "push        %cs                \n\t"
    "call        *12(%ebp)          \n\t"
    "pushf                          \n\t"
    "pushl       %eax               \n\t"
    "movl        8(%ebp),%eax       \n\t"
    "movl        %ebx,4(%eax)       \n\t"
    "movl        %ecx,8(%eax)       \n\t"
    "movl        %edx,12(%eax)      \n\t"
    "movl        %esi,16(%eax)      \n\t"
    "movl        %edi,20(%eax)      \n\t"
    "movw        %ds,24(%eax)       \n\t"
    "movw        %es,26(%eax)       \n\t"
    "popl        %ebx               \n\t"
    "movl        %ebx,(%eax)        \n\t"
    "popl        %ebx               \n\t"
    "movl        %ebx,28(%eax)      \n\t"
    "pop         %es                \n\t"
    "popf                           \n\t"
    "popa                           \n\t"
    "leave                          \n\t"
    "ret                            \n\t"
    ".previous");


/*
 *	cru_detect
 *
 *	Routine Description:
 *	This function uses the 32-bit BIOS Service Directory record to
 *	search for a $CRU record.
 *
 *	Return Value:
 *	0        :  SUCCESS
 *	<0       :  FAILURE
 */
static int __devinit cru_detect(unsigned long map_entry,
	unsigned long map_offset)
{
	void *bios32_map;
	unsigned long *bios32_entrypoint;
	unsigned long cru_physical_address;
	unsigned long cru_length;
	unsigned long physical_bios_base = 0;
	unsigned long physical_bios_offset = 0;
	int retval = -ENODEV;

	bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));

	if (bios32_map == NULL)
		return -ENODEV;

	bios32_entrypoint = bios32_map + map_offset;

	cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;

	asminline_call(&cmn_regs, bios32_entrypoint);

	if (cmn_regs.u1.ral != 0) {
		printk(KERN_WARNING
			"hpwdt: Call succeeded but with an error: 0x%x\n",
			cmn_regs.u1.ral);
	} else {
		physical_bios_base = cmn_regs.u2.rebx;
		physical_bios_offset = cmn_regs.u4.redx;
		cru_length = cmn_regs.u3.recx;
		cru_physical_address =
			physical_bios_base + physical_bios_offset;

		/* If the values look OK, then map it in. */
		if ((physical_bios_base + physical_bios_offset)) {
			cru_rom_addr =
				ioremap(cru_physical_address, cru_length);
			if (cru_rom_addr)
				retval = 0;
		}

		printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
			physical_bios_base);
		printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
			physical_bios_offset);
		printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
			cru_length);
		printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
			(unsigned int)&cru_rom_addr);
	}
	iounmap(bios32_map);
	return retval;
}

/*
 *	bios_checksum
 */
static int __devinit bios_checksum(const char __iomem *ptr, int len)
{
	char sum = 0;
	int i;

	/*
	 * calculate checksum of size bytes. This should add up
	 * to zero if we have a valid header.
	 */
	for (i = 0; i < len; i++)
		sum += ptr[i];

	return ((sum == 0) && (len > 0));
}

/*
 *	bios32_present
 *
 *	Routine Description:
 *	This function finds the 32-bit BIOS Service Directory
 *
 *	Return Value:
 *	0        :  SUCCESS
 *	<0       :  FAILURE
 */
static int __devinit bios32_present(const char __iomem *p)
{
	struct bios32_service_dir *bios_32_ptr;
	int length;
	unsigned long map_entry, map_offset;

	bios_32_ptr = (struct bios32_service_dir *) p;

	/*
	 * Search for signature by checking equal to the swizzled value
	 * instead of calling another routine to perform a strcmp.
	 */
	if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
		length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
		if (bios_checksum(p, length)) {
			/*
			 * According to the spec, we're looking for the
			 * first 4KB-aligned address below the entrypoint
			 * listed in the header. The Service Directory code
			 * is guaranteed to occupy no more than 2 4KB pages.
			 */
			map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
			map_offset = bios_32_ptr->entry_point - map_entry;

			return cru_detect(map_entry, map_offset);
		}
	}
	return -ENODEV;
}

static int __devinit detect_cru_service(void)
{
	char __iomem *p, *q;
	int rc = -1;

	/*
	 * Search from 0x0f0000 through 0x0fffff, inclusive.
	 */
	p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
	if (p == NULL)
		return -ENOMEM;

	for (q = p; q < p + ROM_SIZE; q += 16) {
		rc = bios32_present(q);
		if (!rc)
			break;
	}
	iounmap(p);
	return rc;
}

#else
/* --64 Bit Bios------------------------------------------------------------ */

#define HPWDT_ARCH	64

asm(".text                      \n\t"
    ".align 4                   \n"
    "asminline_call:            \n\t"
    "pushq      %rbp            \n\t"
    "movq       %rsp, %rbp      \n\t"
    "pushq      %rax            \n\t"
    "pushq      %rbx            \n\t"
    "pushq      %rdx            \n\t"
    "pushq      %r12            \n\t"
    "pushq      %r9             \n\t"
    "movq       %rsi, %r12      \n\t"
    "movq       %rdi, %r9       \n\t"
    "movl       4(%r9),%ebx     \n\t"
    "movl       8(%r9),%ecx     \n\t"
    "movl       12(%r9),%edx    \n\t"
    "movl       16(%r9),%esi    \n\t"
    "movl       20(%r9),%edi    \n\t"
    "movl       (%r9),%eax      \n\t"
    "call       *%r12           \n\t"
    "pushfq                     \n\t"
    "popq        %r12           \n\t"
    "movl       %eax, (%r9)     \n\t"
    "movl       %ebx, 4(%r9)    \n\t"
    "movl       %ecx, 8(%r9)    \n\t"
    "movl       %edx, 12(%r9)   \n\t"
    "movl       %esi, 16(%r9)   \n\t"
    "movl       %edi, 20(%r9)   \n\t"
    "movq       %r12, %rax      \n\t"
    "movl       %eax, 28(%r9)   \n\t"
    "popq       %r9             \n\t"
    "popq       %r12            \n\t"
    "popq       %rdx            \n\t"
    "popq       %rbx            \n\t"
    "popq       %rax            \n\t"
    "leave                      \n\t"
    "ret                        \n\t"
    ".previous");

/*
 *	dmi_find_cru
 *
 *	Routine Description:
 *	This function checks whether or not a SMBIOS/DMI record is
 *	the 64bit CRU info or not
 */
static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
{
	struct smbios_cru64_info *smbios_cru64_ptr;
	unsigned long cru_physical_address;

	if (dm->type == SMBIOS_CRU64_INFORMATION) {
		smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
		if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
			cru_physical_address =
				smbios_cru64_ptr->physical_address +
				smbios_cru64_ptr->double_offset;
			cru_rom_addr = ioremap(cru_physical_address,
				smbios_cru64_ptr->double_length);
			set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
				smbios_cru64_ptr->double_length >> PAGE_SHIFT);
		}
	}
}

static int __devinit detect_cru_service(void)
{
	cru_rom_addr = NULL;

	dmi_walk(dmi_find_cru, NULL);

	/* if cru_rom_addr has been set then we found a CRU service */
	return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
}

/* ------------------------------------------------------------------------- */

#endif

/*
 *	Watchdog operations
 */
static void hpwdt_start(void)
{
	reload = (soft_margin * 1000) / 128;
	iowrite16(reload, hpwdt_timer_reg);
	iowrite16(0x85, hpwdt_timer_con);
}

static void hpwdt_stop(void)
{
	unsigned long data;

	data = ioread16(hpwdt_timer_con);
	data &= 0xFE;
	iowrite16(data, hpwdt_timer_con);
}

static void hpwdt_ping(void)
{
	iowrite16(reload, hpwdt_timer_reg);
}

static int hpwdt_change_timer(int new_margin)
{
	/* Arbitrary, can't find the card's limits */
	if (new_margin < 30 || new_margin > 600) {
		printk(KERN_WARNING
			"hpwdt: New value passed in is invalid: %d seconds.\n",
			new_margin);
		return -EINVAL;
	}

	soft_margin = new_margin;
	printk(KERN_DEBUG
		"hpwdt: New timer passed in is %d seconds.\n",
		new_margin);
	reload = (soft_margin * 1000) / 128;

	return 0;
}

/*
 *	NMI Handler
 */
static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
				void *data)
{
	unsigned long rom_pl;
	static int die_nmi_called;

	if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
		return NOTIFY_OK;

	if (hpwdt_nmi_sourcing) {
		spin_lock_irqsave(&rom_lock, rom_pl);
		if (!die_nmi_called)
			asminline_call(&cmn_regs, cru_rom_addr);
		die_nmi_called = 1;
		spin_unlock_irqrestore(&rom_lock, rom_pl);
		if (cmn_regs.u1.ral == 0) {
			printk(KERN_WARNING "hpwdt: An NMI occurred, "
				"but unable to determine source.\n");
		} else {
			if (allow_kdump)
				hpwdt_stop();
			panic("An NMI occurred, please see the Integrated "
				"Management Log for details.\n");
		}
	}
	return NOTIFY_OK;
}

/*
 *	/dev/watchdog handling
 */
static int hpwdt_open(struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */
	if (test_and_set_bit(0, &hpwdt_is_open))
		return -EBUSY;

	/* Start the watchdog */
	hpwdt_start();
	hpwdt_ping();

	return nonseekable_open(inode, file);
}

static int hpwdt_release(struct inode *inode, struct file *file)
{
	/* Stop the watchdog */
	if (expect_release == 42) {
		hpwdt_stop();
	} else {
		printk(KERN_CRIT
			"hpwdt: Unexpected close, not stopping watchdog!\n");
		hpwdt_ping();
	}

	expect_release = 0;

	/* /dev/watchdog is being closed, make sure it can be re-opened */
	clear_bit(0, &hpwdt_is_open);

	return 0;
}

static ssize_t hpwdt_write(struct file *file, const char __user *data,
	size_t len, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* note: just in case someone wrote the magic character
			 * five months ago... */
			expect_release = 0;

			/* scan to see whether or not we got the magic char. */
			for (i = 0; i != len; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					expect_release = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		hpwdt_ping();
	}

	return len;
}

static struct watchdog_info ident = {
	.options = WDIOF_SETTIMEOUT |
		   WDIOF_KEEPALIVEPING |
		   WDIOF_MAGICCLOSE,
	.identity = "HP iLO2 HW Watchdog Timer",
};

static long hpwdt_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_margin;
	int ret = -ENOTTY;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		ret = 0;
		if (copy_to_user(argp, &ident, sizeof(ident)))
			ret = -EFAULT;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		ret = put_user(0, p);
		break;

	case WDIOC_KEEPALIVE:
		hpwdt_ping();
		ret = 0;
		break;

	case WDIOC_SETTIMEOUT:
		ret = get_user(new_margin, p);
		if (ret)
			break;

		ret = hpwdt_change_timer(new_margin);
		if (ret)
			break;

		hpwdt_ping();
		/* Fall */
	case WDIOC_GETTIMEOUT:
		ret = put_user(soft_margin, p);
		break;
	}
	return ret;
}

/*
 *	Kernel interfaces
 */
static const struct file_operations hpwdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = hpwdt_write,
	.unlocked_ioctl = hpwdt_ioctl,
	.open = hpwdt_open,
	.release = hpwdt_release,
};

static struct miscdevice hpwdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &hpwdt_fops,
};

static struct notifier_block die_notifier = {
	.notifier_call = hpwdt_pretimeout,
	.priority = 0,
};

/*
 *	Init & Exit
 */

#ifdef ARCH_HAS_NMI_WATCHDOG
static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
{
	/*
	 * If nmi_watchdog is turned off then we can turn on
	 * our nmi sourcing capability.
	 */
	if (!nmi_watchdog_active())
		hpwdt_nmi_sourcing = 1;
	else
		dev_warn(&dev->dev, "NMI sourcing is disabled. To enable this "
			"functionality you must reboot with nmi_watchdog=0 "
			"and load the hpwdt driver with priority=1.\n");
}
#else
static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)
{
	dev_warn(&dev->dev, "NMI sourcing is disabled. "
		"Your kernel does not support a NMI Watchdog.\n");
}
#endif

static int __devinit hpwdt_init_one(struct pci_dev *dev,
					const struct pci_device_id *ent)
{
	int retval;

	/*
	 * Check if we can do NMI sourcing or not
	 */
	hpwdt_check_nmi_sourcing(dev);

	/*
	 * First let's find out if we are on an iLO2 server. We will
	 * not run on a legacy ASM box.
	 * So we only support the G5 ProLiant servers and higher.
	 */
	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
		dev_warn(&dev->dev,
			"This server does not have an iLO2 ASIC.\n");
		return -ENODEV;
	}

	if (pci_enable_device(dev)) {
		dev_warn(&dev->dev,
			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
			ent->vendor, ent->device);
		return -ENODEV;
	}

	pci_mem_addr = pci_iomap(dev, 1, 0x80);
	if (!pci_mem_addr) {
		dev_warn(&dev->dev,
			"Unable to detect the iLO2 server memory.\n");
		retval = -ENOMEM;
		goto error_pci_iomap;
	}
	hpwdt_timer_reg = pci_mem_addr + 0x70;
	hpwdt_timer_con = pci_mem_addr + 0x72;

	/* Make sure that we have a valid soft_margin */
	if (hpwdt_change_timer(soft_margin))
		hpwdt_change_timer(DEFAULT_MARGIN);

	/*
	 * We need to map the ROM to get the CRU service.
	 * For 32 bit Operating Systems we need to go through the 32 Bit
	 * BIOS Service Directory
	 * For 64 bit Operating Systems we get that service through SMBIOS.
	 */
	retval = detect_cru_service();
	if (retval < 0) {
		dev_warn(&dev->dev,
			"Unable to detect the %d Bit CRU Service.\n",
			HPWDT_ARCH);
		goto error_get_cru;
	}

	/*
	 * We know this is the only CRU call we need to make so lets keep as
	 * few instructions as possible once the NMI comes in.
	 */
	cmn_regs.u1.rah = 0x0D;
	cmn_regs.u1.ral = 0x02;

	/*
	 * If the priority is set to 1, then we will be put first on the
	 * die notify list to handle a critical NMI. The default is to
	 * be last so other users of the NMI signal can function.
	 */
	if (priority)
		die_notifier.priority = 0x7FFFFFFF;

	retval = register_die_notifier(&die_notifier);
	if (retval != 0) {
		dev_warn(&dev->dev,
			"Unable to register a die notifier (err=%d).\n",
			retval);
		goto error_die_notifier;
	}

	retval = misc_register(&hpwdt_miscdev);
	if (retval < 0) {
		dev_warn(&dev->dev,
			"Unable to register miscdev on minor=%d (err=%d).\n",
			WATCHDOG_MINOR, retval);
		goto error_misc_register;
	}

	printk(KERN_INFO
		"hp Watchdog Timer Driver: %s"
		", timer margin: %d seconds (nowayout=%d)"
		", allow kernel dump: %s (default = 0/OFF)"
		", priority: %s (default = 0/LAST).\n",
		HPWDT_VERSION, soft_margin, nowayout,
		(allow_kdump == 0) ? "OFF" : "ON",
		(priority == 0) ? "LAST" : "FIRST");

	return 0;

error_misc_register:
	unregister_die_notifier(&die_notifier);
error_die_notifier:
	if (cru_rom_addr)
		iounmap(cru_rom_addr);
error_get_cru:
	pci_iounmap(dev, pci_mem_addr);
error_pci_iomap:
	pci_disable_device(dev);
	return retval;
}

static void __devexit hpwdt_exit(struct pci_dev *dev)
{
	if (!nowayout)
		hpwdt_stop();

	misc_deregister(&hpwdt_miscdev);
	unregister_die_notifier(&die_notifier);

	if (cru_rom_addr)
		iounmap(cru_rom_addr);
	pci_iounmap(dev, pci_mem_addr);
	pci_disable_device(dev);
}

static struct pci_driver hpwdt_driver = {
	.name = "hpwdt",
	.id_table = hpwdt_devices,
	.probe = hpwdt_init_one,
	.remove = __devexit_p(hpwdt_exit),
};

static void __exit hpwdt_cleanup(void)
{
	pci_unregister_driver(&hpwdt_driver);
}

static int __init hpwdt_init(void)
{
	return pci_register_driver(&hpwdt_driver);
}

MODULE_AUTHOR("Tom Mingarelli");
MODULE_DESCRIPTION("hp watchdog driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(HPWDT_VERSION);
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

module_param(soft_margin, int, 0);
MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");

module_param(allow_kdump, int, 0);
MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

module_param(priority, int, 0);
MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
		" (default = 0/Last)\n");

module_init(hpwdt_init);
module_exit(hpwdt_cleanup);