xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision 7490ca1e)
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 #include <asm/nmi.h>
39 
40 #define HPWDT_VERSION			"1.3.0"
41 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
42 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
43 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(65535)
44 #define DEFAULT_MARGIN			30
45 
46 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
47 static unsigned int reload;			/* the computed soft_margin */
48 static int nowayout = WATCHDOG_NOWAYOUT;
49 static char expect_release;
50 static unsigned long hpwdt_is_open;
51 
52 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
53 static unsigned long __iomem *hpwdt_timer_reg;
54 static unsigned long __iomem *hpwdt_timer_con;
55 
56 static DEFINE_PCI_DEVICE_TABLE(hpwdt_devices) = {
57 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
58 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
59 	{0},			/* terminate list */
60 };
61 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
62 
63 #ifdef CONFIG_HPWDT_NMI_DECODING
64 #define PCI_BIOS32_SD_VALUE		0x5F32335F	/* "_32_" */
65 #define CRU_BIOS_SIGNATURE_VALUE	0x55524324
66 #define PCI_BIOS32_PARAGRAPH_LEN	16
67 #define PCI_ROM_BASE1			0x000F0000
68 #define ROM_SIZE			0x10000
69 
70 struct bios32_service_dir {
71 	u32 signature;
72 	u32 entry_point;
73 	u8 revision;
74 	u8 length;
75 	u8 checksum;
76 	u8 reserved[5];
77 };
78 
79 /* type 212 */
80 struct smbios_cru64_info {
81 	u8 type;
82 	u8 byte_length;
83 	u16 handle;
84 	u32 signature;
85 	u64 physical_address;
86 	u32 double_length;
87 	u32 double_offset;
88 };
89 #define SMBIOS_CRU64_INFORMATION	212
90 
91 /* type 219 */
92 struct smbios_proliant_info {
93 	u8 type;
94 	u8 byte_length;
95 	u16 handle;
96 	u32 power_features;
97 	u32 omega_features;
98 	u32 reserved;
99 	u32 misc_features;
100 };
101 #define SMBIOS_ICRU_INFORMATION		219
102 
103 
104 struct cmn_registers {
105 	union {
106 		struct {
107 			u8 ral;
108 			u8 rah;
109 			u16 rea2;
110 		};
111 		u32 reax;
112 	} u1;
113 	union {
114 		struct {
115 			u8 rbl;
116 			u8 rbh;
117 			u8 reb2l;
118 			u8 reb2h;
119 		};
120 		u32 rebx;
121 	} u2;
122 	union {
123 		struct {
124 			u8 rcl;
125 			u8 rch;
126 			u16 rec2;
127 		};
128 		u32 recx;
129 	} u3;
130 	union {
131 		struct {
132 			u8 rdl;
133 			u8 rdh;
134 			u16 red2;
135 		};
136 		u32 redx;
137 	} u4;
138 
139 	u32 resi;
140 	u32 redi;
141 	u16 rds;
142 	u16 res;
143 	u32 reflags;
144 }  __attribute__((packed));
145 
146 static unsigned int hpwdt_nmi_decoding;
147 static unsigned int allow_kdump;
148 static unsigned int priority;		/* hpwdt at end of die_notify list */
149 static unsigned int is_icru;
150 static DEFINE_SPINLOCK(rom_lock);
151 static void *cru_rom_addr;
152 static struct cmn_registers cmn_regs;
153 
154 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
155 						unsigned long *pRomEntry);
156 
157 #ifdef CONFIG_X86_32
158 /* --32 Bit Bios------------------------------------------------------------ */
159 
160 #define HPWDT_ARCH	32
161 
162 asm(".text                          \n\t"
163     ".align 4                       \n"
164     "asminline_call:                \n\t"
165     "pushl       %ebp               \n\t"
166     "movl        %esp, %ebp         \n\t"
167     "pusha                          \n\t"
168     "pushf                          \n\t"
169     "push        %es                \n\t"
170     "push        %ds                \n\t"
171     "pop         %es                \n\t"
172     "movl        8(%ebp),%eax       \n\t"
173     "movl        4(%eax),%ebx       \n\t"
174     "movl        8(%eax),%ecx       \n\t"
175     "movl        12(%eax),%edx      \n\t"
176     "movl        16(%eax),%esi      \n\t"
177     "movl        20(%eax),%edi      \n\t"
178     "movl        (%eax),%eax        \n\t"
179     "push        %cs                \n\t"
180     "call        *12(%ebp)          \n\t"
181     "pushf                          \n\t"
182     "pushl       %eax               \n\t"
183     "movl        8(%ebp),%eax       \n\t"
184     "movl        %ebx,4(%eax)       \n\t"
185     "movl        %ecx,8(%eax)       \n\t"
186     "movl        %edx,12(%eax)      \n\t"
187     "movl        %esi,16(%eax)      \n\t"
188     "movl        %edi,20(%eax)      \n\t"
189     "movw        %ds,24(%eax)       \n\t"
190     "movw        %es,26(%eax)       \n\t"
191     "popl        %ebx               \n\t"
192     "movl        %ebx,(%eax)        \n\t"
193     "popl        %ebx               \n\t"
194     "movl        %ebx,28(%eax)      \n\t"
195     "pop         %es                \n\t"
196     "popf                           \n\t"
197     "popa                           \n\t"
198     "leave                          \n\t"
199     "ret                            \n\t"
200     ".previous");
201 
202 
203 /*
204  *	cru_detect
205  *
206  *	Routine Description:
207  *	This function uses the 32-bit BIOS Service Directory record to
208  *	search for a $CRU record.
209  *
210  *	Return Value:
211  *	0        :  SUCCESS
212  *	<0       :  FAILURE
213  */
214 static int __devinit cru_detect(unsigned long map_entry,
215 	unsigned long map_offset)
216 {
217 	void *bios32_map;
218 	unsigned long *bios32_entrypoint;
219 	unsigned long cru_physical_address;
220 	unsigned long cru_length;
221 	unsigned long physical_bios_base = 0;
222 	unsigned long physical_bios_offset = 0;
223 	int retval = -ENODEV;
224 
225 	bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
226 
227 	if (bios32_map == NULL)
228 		return -ENODEV;
229 
230 	bios32_entrypoint = bios32_map + map_offset;
231 
232 	cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
233 
234 	set_memory_x((unsigned long)bios32_entrypoint, (2 * PAGE_SIZE));
235 	asminline_call(&cmn_regs, bios32_entrypoint);
236 
237 	if (cmn_regs.u1.ral != 0) {
238 		printk(KERN_WARNING
239 			"hpwdt: Call succeeded but with an error: 0x%x\n",
240 			cmn_regs.u1.ral);
241 	} else {
242 		physical_bios_base = cmn_regs.u2.rebx;
243 		physical_bios_offset = cmn_regs.u4.redx;
244 		cru_length = cmn_regs.u3.recx;
245 		cru_physical_address =
246 			physical_bios_base + physical_bios_offset;
247 
248 		/* If the values look OK, then map it in. */
249 		if ((physical_bios_base + physical_bios_offset)) {
250 			cru_rom_addr =
251 				ioremap(cru_physical_address, cru_length);
252 			if (cru_rom_addr) {
253 				set_memory_x((unsigned long)cru_rom_addr, cru_length);
254 				retval = 0;
255 			}
256 		}
257 
258 		printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",
259 			physical_bios_base);
260 		printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
261 			physical_bios_offset);
262 		printk(KERN_DEBUG "hpwdt: CRU Length:         0x%lx\n",
263 			cru_length);
264 		printk(KERN_DEBUG "hpwdt: CRU Mapped Address: %p\n",
265 			&cru_rom_addr);
266 	}
267 	iounmap(bios32_map);
268 	return retval;
269 }
270 
271 /*
272  *	bios_checksum
273  */
274 static int __devinit bios_checksum(const char __iomem *ptr, int len)
275 {
276 	char sum = 0;
277 	int i;
278 
279 	/*
280 	 * calculate checksum of size bytes. This should add up
281 	 * to zero if we have a valid header.
282 	 */
283 	for (i = 0; i < len; i++)
284 		sum += ptr[i];
285 
286 	return ((sum == 0) && (len > 0));
287 }
288 
289 /*
290  *	bios32_present
291  *
292  *	Routine Description:
293  *	This function finds the 32-bit BIOS Service Directory
294  *
295  *	Return Value:
296  *	0        :  SUCCESS
297  *	<0       :  FAILURE
298  */
299 static int __devinit bios32_present(const char __iomem *p)
300 {
301 	struct bios32_service_dir *bios_32_ptr;
302 	int length;
303 	unsigned long map_entry, map_offset;
304 
305 	bios_32_ptr = (struct bios32_service_dir *) p;
306 
307 	/*
308 	 * Search for signature by checking equal to the swizzled value
309 	 * instead of calling another routine to perform a strcmp.
310 	 */
311 	if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
312 		length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
313 		if (bios_checksum(p, length)) {
314 			/*
315 			 * According to the spec, we're looking for the
316 			 * first 4KB-aligned address below the entrypoint
317 			 * listed in the header. The Service Directory code
318 			 * is guaranteed to occupy no more than 2 4KB pages.
319 			 */
320 			map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
321 			map_offset = bios_32_ptr->entry_point - map_entry;
322 
323 			return cru_detect(map_entry, map_offset);
324 		}
325 	}
326 	return -ENODEV;
327 }
328 
329 static int __devinit detect_cru_service(void)
330 {
331 	char __iomem *p, *q;
332 	int rc = -1;
333 
334 	/*
335 	 * Search from 0x0f0000 through 0x0fffff, inclusive.
336 	 */
337 	p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
338 	if (p == NULL)
339 		return -ENOMEM;
340 
341 	for (q = p; q < p + ROM_SIZE; q += 16) {
342 		rc = bios32_present(q);
343 		if (!rc)
344 			break;
345 	}
346 	iounmap(p);
347 	return rc;
348 }
349 /* ------------------------------------------------------------------------- */
350 #endif /* CONFIG_X86_32 */
351 #ifdef CONFIG_X86_64
352 /* --64 Bit Bios------------------------------------------------------------ */
353 
354 #define HPWDT_ARCH	64
355 
356 asm(".text                      \n\t"
357     ".align 4                   \n"
358     "asminline_call:            \n\t"
359     "pushq      %rbp            \n\t"
360     "movq       %rsp, %rbp      \n\t"
361     "pushq      %rax            \n\t"
362     "pushq      %rbx            \n\t"
363     "pushq      %rdx            \n\t"
364     "pushq      %r12            \n\t"
365     "pushq      %r9             \n\t"
366     "movq       %rsi, %r12      \n\t"
367     "movq       %rdi, %r9       \n\t"
368     "movl       4(%r9),%ebx     \n\t"
369     "movl       8(%r9),%ecx     \n\t"
370     "movl       12(%r9),%edx    \n\t"
371     "movl       16(%r9),%esi    \n\t"
372     "movl       20(%r9),%edi    \n\t"
373     "movl       (%r9),%eax      \n\t"
374     "call       *%r12           \n\t"
375     "pushfq                     \n\t"
376     "popq        %r12           \n\t"
377     "movl       %eax, (%r9)     \n\t"
378     "movl       %ebx, 4(%r9)    \n\t"
379     "movl       %ecx, 8(%r9)    \n\t"
380     "movl       %edx, 12(%r9)   \n\t"
381     "movl       %esi, 16(%r9)   \n\t"
382     "movl       %edi, 20(%r9)   \n\t"
383     "movq       %r12, %rax      \n\t"
384     "movl       %eax, 28(%r9)   \n\t"
385     "popq       %r9             \n\t"
386     "popq       %r12            \n\t"
387     "popq       %rdx            \n\t"
388     "popq       %rbx            \n\t"
389     "popq       %rax            \n\t"
390     "leave                      \n\t"
391     "ret                        \n\t"
392     ".previous");
393 
394 /*
395  *	dmi_find_cru
396  *
397  *	Routine Description:
398  *	This function checks whether or not a SMBIOS/DMI record is
399  *	the 64bit CRU info or not
400  */
401 static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
402 {
403 	struct smbios_cru64_info *smbios_cru64_ptr;
404 	unsigned long cru_physical_address;
405 
406 	if (dm->type == SMBIOS_CRU64_INFORMATION) {
407 		smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
408 		if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
409 			cru_physical_address =
410 				smbios_cru64_ptr->physical_address +
411 				smbios_cru64_ptr->double_offset;
412 			cru_rom_addr = ioremap(cru_physical_address,
413 				smbios_cru64_ptr->double_length);
414 			set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
415 				smbios_cru64_ptr->double_length >> PAGE_SHIFT);
416 		}
417 	}
418 }
419 
420 static int __devinit detect_cru_service(void)
421 {
422 	cru_rom_addr = NULL;
423 
424 	dmi_walk(dmi_find_cru, NULL);
425 
426 	/* if cru_rom_addr has been set then we found a CRU service */
427 	return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
428 }
429 /* ------------------------------------------------------------------------- */
430 #endif /* CONFIG_X86_64 */
431 #endif /* CONFIG_HPWDT_NMI_DECODING */
432 
433 /*
434  *	Watchdog operations
435  */
436 static void hpwdt_start(void)
437 {
438 	reload = SECS_TO_TICKS(soft_margin);
439 	iowrite16(reload, hpwdt_timer_reg);
440 	iowrite16(0x85, hpwdt_timer_con);
441 }
442 
443 static void hpwdt_stop(void)
444 {
445 	unsigned long data;
446 
447 	data = ioread16(hpwdt_timer_con);
448 	data &= 0xFE;
449 	iowrite16(data, hpwdt_timer_con);
450 }
451 
452 static void hpwdt_ping(void)
453 {
454 	iowrite16(reload, hpwdt_timer_reg);
455 }
456 
457 static int hpwdt_change_timer(int new_margin)
458 {
459 	if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
460 		printk(KERN_WARNING
461 			"hpwdt: New value passed in is invalid: %d seconds.\n",
462 			new_margin);
463 		return -EINVAL;
464 	}
465 
466 	soft_margin = new_margin;
467 	printk(KERN_DEBUG
468 		"hpwdt: New timer passed in is %d seconds.\n",
469 		new_margin);
470 	reload = SECS_TO_TICKS(soft_margin);
471 
472 	return 0;
473 }
474 
475 static int hpwdt_time_left(void)
476 {
477 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
478 }
479 
480 #ifdef CONFIG_HPWDT_NMI_DECODING
481 /*
482  *	NMI Handler
483  */
484 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
485 {
486 	unsigned long rom_pl;
487 	static int die_nmi_called;
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 NMI_DONE;
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 /*
652  *	Init & Exit
653  */
654 
655 #ifdef CONFIG_HPWDT_NMI_DECODING
656 #ifdef CONFIG_X86_LOCAL_APIC
657 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
658 {
659 	/*
660 	 * If nmi_watchdog is turned off then we can turn on
661 	 * our nmi decoding capability.
662 	 */
663 	hpwdt_nmi_decoding = 1;
664 }
665 #else
666 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
667 {
668 	dev_warn(&dev->dev, "NMI decoding is disabled. "
669 		"Your kernel does not support a NMI Watchdog.\n");
670 }
671 #endif /* CONFIG_X86_LOCAL_APIC */
672 
673 /*
674  *	dmi_find_icru
675  *
676  *	Routine Description:
677  *	This function checks whether or not we are on an iCRU-based server.
678  *	This check is independent of architecture and needs to be made for
679  *	any ProLiant system.
680  */
681 static void __devinit dmi_find_icru(const struct dmi_header *dm, void *dummy)
682 {
683 	struct smbios_proliant_info *smbios_proliant_ptr;
684 
685 	if (dm->type == SMBIOS_ICRU_INFORMATION) {
686 		smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
687 		if (smbios_proliant_ptr->misc_features & 0x01)
688 			is_icru = 1;
689 	}
690 }
691 
692 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
693 {
694 	int retval;
695 
696 	/*
697 	 * On typical CRU-based systems we need to map that service in
698 	 * the BIOS. For 32 bit Operating Systems we need to go through
699 	 * the 32 Bit BIOS Service Directory. For 64 bit Operating
700 	 * Systems we get that service through SMBIOS.
701 	 *
702 	 * On systems that support the new iCRU service all we need to
703 	 * do is call dmi_walk to get the supported flag value and skip
704 	 * the old cru detect code.
705 	 */
706 	dmi_walk(dmi_find_icru, NULL);
707 	if (!is_icru) {
708 
709 		/*
710 		* We need to map the ROM to get the CRU service.
711 		* For 32 bit Operating Systems we need to go through the 32 Bit
712 		* BIOS Service Directory
713 		* For 64 bit Operating Systems we get that service through SMBIOS.
714 		*/
715 		retval = detect_cru_service();
716 		if (retval < 0) {
717 			dev_warn(&dev->dev,
718 				"Unable to detect the %d Bit CRU Service.\n",
719 				HPWDT_ARCH);
720 			return retval;
721 		}
722 
723 		/*
724 		* We know this is the only CRU call we need to make so lets keep as
725 		* few instructions as possible once the NMI comes in.
726 		*/
727 		cmn_regs.u1.rah = 0x0D;
728 		cmn_regs.u1.ral = 0x02;
729 	}
730 
731 	/*
732 	 * If the priority is set to 1, then we will be put first on the
733 	 * die notify list to handle a critical NMI. The default is to
734 	 * be last so other users of the NMI signal can function.
735 	 */
736 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout,
737 					(priority) ? NMI_FLAG_FIRST : 0,
738 					"hpwdt");
739 	if (retval != 0) {
740 		dev_warn(&dev->dev,
741 			"Unable to register a die notifier (err=%d).\n",
742 			retval);
743 		if (cru_rom_addr)
744 			iounmap(cru_rom_addr);
745 	}
746 
747 	dev_info(&dev->dev,
748 			"HP Watchdog Timer Driver: NMI decoding initialized"
749 			", allow kernel dump: %s (default = 0/OFF)"
750 			", priority: %s (default = 0/LAST).\n",
751 			(allow_kdump == 0) ? "OFF" : "ON",
752 			(priority == 0) ? "LAST" : "FIRST");
753 	return 0;
754 }
755 
756 static void hpwdt_exit_nmi_decoding(void)
757 {
758 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
759 	if (cru_rom_addr)
760 		iounmap(cru_rom_addr);
761 }
762 #else /* !CONFIG_HPWDT_NMI_DECODING */
763 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
764 {
765 }
766 
767 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
768 {
769 	return 0;
770 }
771 
772 static void hpwdt_exit_nmi_decoding(void)
773 {
774 }
775 #endif /* CONFIG_HPWDT_NMI_DECODING */
776 
777 static int __devinit hpwdt_init_one(struct pci_dev *dev,
778 					const struct pci_device_id *ent)
779 {
780 	int retval;
781 
782 	/*
783 	 * Check if we can do NMI decoding or not
784 	 */
785 	hpwdt_check_nmi_decoding(dev);
786 
787 	/*
788 	 * First let's find out if we are on an iLO2+ server. We will
789 	 * not run on a legacy ASM box.
790 	 * So we only support the G5 ProLiant servers and higher.
791 	 */
792 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
793 		dev_warn(&dev->dev,
794 			"This server does not have an iLO2+ ASIC.\n");
795 		return -ENODEV;
796 	}
797 
798 	if (pci_enable_device(dev)) {
799 		dev_warn(&dev->dev,
800 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
801 			ent->vendor, ent->device);
802 		return -ENODEV;
803 	}
804 
805 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
806 	if (!pci_mem_addr) {
807 		dev_warn(&dev->dev,
808 			"Unable to detect the iLO2+ server memory.\n");
809 		retval = -ENOMEM;
810 		goto error_pci_iomap;
811 	}
812 	hpwdt_timer_reg = pci_mem_addr + 0x70;
813 	hpwdt_timer_con = pci_mem_addr + 0x72;
814 
815 	/* Make sure that we have a valid soft_margin */
816 	if (hpwdt_change_timer(soft_margin))
817 		hpwdt_change_timer(DEFAULT_MARGIN);
818 
819 	/* Initialize NMI Decoding functionality */
820 	retval = hpwdt_init_nmi_decoding(dev);
821 	if (retval != 0)
822 		goto error_init_nmi_decoding;
823 
824 	retval = misc_register(&hpwdt_miscdev);
825 	if (retval < 0) {
826 		dev_warn(&dev->dev,
827 			"Unable to register miscdev on minor=%d (err=%d).\n",
828 			WATCHDOG_MINOR, retval);
829 		goto error_misc_register;
830 	}
831 
832 	dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
833 			", timer margin: %d seconds (nowayout=%d).\n",
834 			HPWDT_VERSION, soft_margin, nowayout);
835 	return 0;
836 
837 error_misc_register:
838 	hpwdt_exit_nmi_decoding();
839 error_init_nmi_decoding:
840 	pci_iounmap(dev, pci_mem_addr);
841 error_pci_iomap:
842 	pci_disable_device(dev);
843 	return retval;
844 }
845 
846 static void __devexit hpwdt_exit(struct pci_dev *dev)
847 {
848 	if (!nowayout)
849 		hpwdt_stop();
850 
851 	misc_deregister(&hpwdt_miscdev);
852 	hpwdt_exit_nmi_decoding();
853 	pci_iounmap(dev, pci_mem_addr);
854 	pci_disable_device(dev);
855 }
856 
857 static struct pci_driver hpwdt_driver = {
858 	.name = "hpwdt",
859 	.id_table = hpwdt_devices,
860 	.probe = hpwdt_init_one,
861 	.remove = __devexit_p(hpwdt_exit),
862 };
863 
864 static void __exit hpwdt_cleanup(void)
865 {
866 	pci_unregister_driver(&hpwdt_driver);
867 }
868 
869 static int __init hpwdt_init(void)
870 {
871 	return pci_register_driver(&hpwdt_driver);
872 }
873 
874 MODULE_AUTHOR("Tom Mingarelli");
875 MODULE_DESCRIPTION("hp watchdog driver");
876 MODULE_LICENSE("GPL");
877 MODULE_VERSION(HPWDT_VERSION);
878 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
879 
880 module_param(soft_margin, int, 0);
881 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
882 
883 module_param(nowayout, int, 0);
884 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
885 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
886 
887 #ifdef CONFIG_HPWDT_NMI_DECODING
888 module_param(allow_kdump, int, 0);
889 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
890 
891 module_param(priority, int, 0);
892 MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
893 		" (default = 0/Last)\n");
894 #endif /* !CONFIG_HPWDT_NMI_DECODING */
895 
896 module_init(hpwdt_init);
897 module_exit(hpwdt_cleanup);
898