xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision e3b9f1e8)
1 /*
2  *	HPE WatchDog Driver
3  *	based on
4  *
5  *	SoftDog	0.05:	A Software Watchdog Device
6  *
7  *	(c) Copyright 2015 Hewlett Packard Enterprise Development LP
8  *	Thomas Mingarelli <thomas.mingarelli@hpe.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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/device.h>
19 #include <linux/fs.h>
20 #include <linux/io.h>
21 #include <linux/bitops.h>
22 #include <linux/kernel.h>
23 #include <linux/miscdevice.h>
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/pci.h>
27 #include <linux/pci_ids.h>
28 #include <linux/types.h>
29 #include <linux/uaccess.h>
30 #include <linux/watchdog.h>
31 #ifdef CONFIG_HPWDT_NMI_DECODING
32 #include <linux/dmi.h>
33 #include <linux/spinlock.h>
34 #include <linux/nmi.h>
35 #include <linux/kdebug.h>
36 #include <linux/notifier.h>
37 #include <asm/set_memory.h>
38 #endif /* CONFIG_HPWDT_NMI_DECODING */
39 #include <asm/nmi.h>
40 #include <asm/frame.h>
41 
42 #define HPWDT_VERSION			"1.4.0"
43 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
44 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
45 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(65535)
46 #define DEFAULT_MARGIN			30
47 
48 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
49 static unsigned int reload;			/* the computed soft_margin */
50 static bool nowayout = WATCHDOG_NOWAYOUT;
51 static char expect_release;
52 static unsigned long hpwdt_is_open;
53 
54 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
55 static unsigned long __iomem *hpwdt_nmistat;
56 static unsigned long __iomem *hpwdt_timer_reg;
57 static unsigned long __iomem *hpwdt_timer_con;
58 
59 static const struct pci_device_id hpwdt_devices[] = {
60 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
61 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
62 	{0},			/* terminate list */
63 };
64 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
65 
66 #ifdef CONFIG_HPWDT_NMI_DECODING
67 #define PCI_BIOS32_SD_VALUE		0x5F32335F	/* "_32_" */
68 #define CRU_BIOS_SIGNATURE_VALUE	0x55524324
69 #define PCI_BIOS32_PARAGRAPH_LEN	16
70 #define PCI_ROM_BASE1			0x000F0000
71 #define ROM_SIZE			0x10000
72 
73 struct bios32_service_dir {
74 	u32 signature;
75 	u32 entry_point;
76 	u8 revision;
77 	u8 length;
78 	u8 checksum;
79 	u8 reserved[5];
80 };
81 
82 /* type 212 */
83 struct smbios_cru64_info {
84 	u8 type;
85 	u8 byte_length;
86 	u16 handle;
87 	u32 signature;
88 	u64 physical_address;
89 	u32 double_length;
90 	u32 double_offset;
91 };
92 #define SMBIOS_CRU64_INFORMATION	212
93 
94 /* type 219 */
95 struct smbios_proliant_info {
96 	u8 type;
97 	u8 byte_length;
98 	u16 handle;
99 	u32 power_features;
100 	u32 omega_features;
101 	u32 reserved;
102 	u32 misc_features;
103 };
104 #define SMBIOS_ICRU_INFORMATION		219
105 
106 
107 struct cmn_registers {
108 	union {
109 		struct {
110 			u8 ral;
111 			u8 rah;
112 			u16 rea2;
113 		};
114 		u32 reax;
115 	} u1;
116 	union {
117 		struct {
118 			u8 rbl;
119 			u8 rbh;
120 			u8 reb2l;
121 			u8 reb2h;
122 		};
123 		u32 rebx;
124 	} u2;
125 	union {
126 		struct {
127 			u8 rcl;
128 			u8 rch;
129 			u16 rec2;
130 		};
131 		u32 recx;
132 	} u3;
133 	union {
134 		struct {
135 			u8 rdl;
136 			u8 rdh;
137 			u16 red2;
138 		};
139 		u32 redx;
140 	} u4;
141 
142 	u32 resi;
143 	u32 redi;
144 	u16 rds;
145 	u16 res;
146 	u32 reflags;
147 }  __attribute__((packed));
148 
149 static unsigned int hpwdt_nmi_decoding;
150 static unsigned int allow_kdump = 1;
151 static unsigned int is_icru;
152 static unsigned int is_uefi;
153 static DEFINE_SPINLOCK(rom_lock);
154 static void *cru_rom_addr;
155 static struct cmn_registers cmn_regs;
156 
157 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
158 						unsigned long *pRomEntry);
159 
160 #ifdef CONFIG_X86_32
161 /* --32 Bit Bios------------------------------------------------------------ */
162 
163 #define HPWDT_ARCH	32
164 
165 asm(".text                          \n\t"
166     ".align 4                       \n\t"
167     ".globl asminline_call	    \n"
168     "asminline_call:                \n\t"
169     "pushl       %ebp               \n\t"
170     "movl        %esp, %ebp         \n\t"
171     "pusha                          \n\t"
172     "pushf                          \n\t"
173     "push        %es                \n\t"
174     "push        %ds                \n\t"
175     "pop         %es                \n\t"
176     "movl        8(%ebp),%eax       \n\t"
177     "movl        4(%eax),%ebx       \n\t"
178     "movl        8(%eax),%ecx       \n\t"
179     "movl        12(%eax),%edx      \n\t"
180     "movl        16(%eax),%esi      \n\t"
181     "movl        20(%eax),%edi      \n\t"
182     "movl        (%eax),%eax        \n\t"
183     "push        %cs                \n\t"
184     "call        *12(%ebp)          \n\t"
185     "pushf                          \n\t"
186     "pushl       %eax               \n\t"
187     "movl        8(%ebp),%eax       \n\t"
188     "movl        %ebx,4(%eax)       \n\t"
189     "movl        %ecx,8(%eax)       \n\t"
190     "movl        %edx,12(%eax)      \n\t"
191     "movl        %esi,16(%eax)      \n\t"
192     "movl        %edi,20(%eax)      \n\t"
193     "movw        %ds,24(%eax)       \n\t"
194     "movw        %es,26(%eax)       \n\t"
195     "popl        %ebx               \n\t"
196     "movl        %ebx,(%eax)        \n\t"
197     "popl        %ebx               \n\t"
198     "movl        %ebx,28(%eax)      \n\t"
199     "pop         %es                \n\t"
200     "popf                           \n\t"
201     "popa                           \n\t"
202     "leave                          \n\t"
203     "ret                            \n\t"
204     ".previous");
205 
206 
207 /*
208  *	cru_detect
209  *
210  *	Routine Description:
211  *	This function uses the 32-bit BIOS Service Directory record to
212  *	search for a $CRU record.
213  *
214  *	Return Value:
215  *	0        :  SUCCESS
216  *	<0       :  FAILURE
217  */
218 static int cru_detect(unsigned long map_entry,
219 	unsigned long map_offset)
220 {
221 	void *bios32_map;
222 	unsigned long *bios32_entrypoint;
223 	unsigned long cru_physical_address;
224 	unsigned long cru_length;
225 	unsigned long physical_bios_base = 0;
226 	unsigned long physical_bios_offset = 0;
227 	int retval = -ENODEV;
228 
229 	bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
230 
231 	if (bios32_map == NULL)
232 		return -ENODEV;
233 
234 	bios32_entrypoint = bios32_map + map_offset;
235 
236 	cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
237 
238 	set_memory_x((unsigned long)bios32_map, 2);
239 	asminline_call(&cmn_regs, bios32_entrypoint);
240 
241 	if (cmn_regs.u1.ral != 0) {
242 		pr_warn("Call succeeded but with an error: 0x%x\n",
243 			cmn_regs.u1.ral);
244 	} else {
245 		physical_bios_base = cmn_regs.u2.rebx;
246 		physical_bios_offset = cmn_regs.u4.redx;
247 		cru_length = cmn_regs.u3.recx;
248 		cru_physical_address =
249 			physical_bios_base + physical_bios_offset;
250 
251 		/* If the values look OK, then map it in. */
252 		if ((physical_bios_base + physical_bios_offset)) {
253 			cru_rom_addr =
254 				ioremap(cru_physical_address, cru_length);
255 			if (cru_rom_addr) {
256 				set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
257 					(cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
258 				retval = 0;
259 			}
260 		}
261 
262 		pr_debug("CRU Base Address:   0x%lx\n", physical_bios_base);
263 		pr_debug("CRU Offset Address: 0x%lx\n", physical_bios_offset);
264 		pr_debug("CRU Length:         0x%lx\n", cru_length);
265 		pr_debug("CRU Mapped Address: %p\n", &cru_rom_addr);
266 	}
267 	iounmap(bios32_map);
268 	return retval;
269 }
270 
271 /*
272  *	bios_checksum
273  */
274 static int 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 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 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\t"
358     ".globl asminline_call	\n\t"
359     ".type asminline_call, @function \n\t"
360     "asminline_call:            \n\t"
361     FRAME_BEGIN
362     "pushq      %rax            \n\t"
363     "pushq      %rbx            \n\t"
364     "pushq      %rdx            \n\t"
365     "pushq      %r12            \n\t"
366     "pushq      %r9             \n\t"
367     "movq       %rsi, %r12      \n\t"
368     "movq       %rdi, %r9       \n\t"
369     "movl       4(%r9),%ebx     \n\t"
370     "movl       8(%r9),%ecx     \n\t"
371     "movl       12(%r9),%edx    \n\t"
372     "movl       16(%r9),%esi    \n\t"
373     "movl       20(%r9),%edi    \n\t"
374     "movl       (%r9),%eax      \n\t"
375     "call       *%r12           \n\t"
376     "pushfq                     \n\t"
377     "popq        %r12           \n\t"
378     "movl       %eax, (%r9)     \n\t"
379     "movl       %ebx, 4(%r9)    \n\t"
380     "movl       %ecx, 8(%r9)    \n\t"
381     "movl       %edx, 12(%r9)   \n\t"
382     "movl       %esi, 16(%r9)   \n\t"
383     "movl       %edi, 20(%r9)   \n\t"
384     "movq       %r12, %rax      \n\t"
385     "movl       %eax, 28(%r9)   \n\t"
386     "popq       %r9             \n\t"
387     "popq       %r12            \n\t"
388     "popq       %rdx            \n\t"
389     "popq       %rbx            \n\t"
390     "popq       %rax            \n\t"
391     FRAME_END
392     "ret                        \n\t"
393     ".previous");
394 
395 /*
396  *	dmi_find_cru
397  *
398  *	Routine Description:
399  *	This function checks whether or not a SMBIOS/DMI record is
400  *	the 64bit CRU info or not
401  */
402 static void dmi_find_cru(const struct dmi_header *dm, void *dummy)
403 {
404 	struct smbios_cru64_info *smbios_cru64_ptr;
405 	unsigned long cru_physical_address;
406 
407 	if (dm->type == SMBIOS_CRU64_INFORMATION) {
408 		smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
409 		if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
410 			cru_physical_address =
411 				smbios_cru64_ptr->physical_address +
412 				smbios_cru64_ptr->double_offset;
413 			cru_rom_addr = ioremap(cru_physical_address,
414 				smbios_cru64_ptr->double_length);
415 			set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
416 				smbios_cru64_ptr->double_length >> PAGE_SHIFT);
417 		}
418 	}
419 }
420 
421 static int detect_cru_service(void)
422 {
423 	cru_rom_addr = NULL;
424 
425 	dmi_walk(dmi_find_cru, NULL);
426 
427 	/* if cru_rom_addr has been set then we found a CRU service */
428 	return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
429 }
430 /* ------------------------------------------------------------------------- */
431 #endif /* CONFIG_X86_64 */
432 #endif /* CONFIG_HPWDT_NMI_DECODING */
433 
434 /*
435  *	Watchdog operations
436  */
437 static void hpwdt_start(void)
438 {
439 	reload = SECS_TO_TICKS(soft_margin);
440 	iowrite16(reload, hpwdt_timer_reg);
441 	iowrite8(0x85, hpwdt_timer_con);
442 }
443 
444 static void hpwdt_stop(void)
445 {
446 	unsigned long data;
447 
448 	data = ioread8(hpwdt_timer_con);
449 	data &= 0xFE;
450 	iowrite8(data, hpwdt_timer_con);
451 }
452 
453 static void hpwdt_ping(void)
454 {
455 	iowrite16(reload, hpwdt_timer_reg);
456 }
457 
458 static int hpwdt_change_timer(int new_margin)
459 {
460 	if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
461 		pr_warn("New value passed in is invalid: %d seconds\n",
462 			new_margin);
463 		return -EINVAL;
464 	}
465 
466 	soft_margin = new_margin;
467 	pr_debug("New timer passed in is %d seconds\n", new_margin);
468 	reload = SECS_TO_TICKS(soft_margin);
469 
470 	return 0;
471 }
472 
473 static int hpwdt_time_left(void)
474 {
475 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
476 }
477 
478 #ifdef CONFIG_HPWDT_NMI_DECODING
479 static int hpwdt_my_nmi(void)
480 {
481 	return ioread8(hpwdt_nmistat) & 0x6;
482 }
483 
484 /*
485  *	NMI Handler
486  */
487 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
488 {
489 	unsigned long rom_pl;
490 	static int die_nmi_called;
491 
492 	if (!hpwdt_nmi_decoding)
493 		return NMI_DONE;
494 
495 	if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi())
496 		return NMI_DONE;
497 
498 	spin_lock_irqsave(&rom_lock, rom_pl);
499 	if (!die_nmi_called && !is_icru && !is_uefi)
500 		asminline_call(&cmn_regs, cru_rom_addr);
501 	die_nmi_called = 1;
502 	spin_unlock_irqrestore(&rom_lock, rom_pl);
503 
504 	if (allow_kdump)
505 		hpwdt_stop();
506 
507 	if (!is_icru && !is_uefi) {
508 		if (cmn_regs.u1.ral == 0) {
509 			nmi_panic(regs, "An NMI occurred, but unable to determine source.\n");
510 			return NMI_HANDLED;
511 		}
512 	}
513 	nmi_panic(regs, "An NMI occurred. Depending on your system the reason "
514 		"for the NMI is logged in any one of the following "
515 		"resources:\n"
516 		"1. Integrated Management Log (IML)\n"
517 		"2. OA Syslog\n"
518 		"3. OA Forward Progress Log\n"
519 		"4. iLO Event Log");
520 
521 	return NMI_HANDLED;
522 }
523 #endif /* CONFIG_HPWDT_NMI_DECODING */
524 
525 /*
526  *	/dev/watchdog handling
527  */
528 static int hpwdt_open(struct inode *inode, struct file *file)
529 {
530 	/* /dev/watchdog can only be opened once */
531 	if (test_and_set_bit(0, &hpwdt_is_open))
532 		return -EBUSY;
533 
534 	/* Start the watchdog */
535 	hpwdt_start();
536 	hpwdt_ping();
537 
538 	return nonseekable_open(inode, file);
539 }
540 
541 static int hpwdt_release(struct inode *inode, struct file *file)
542 {
543 	/* Stop the watchdog */
544 	if (expect_release == 42) {
545 		hpwdt_stop();
546 	} else {
547 		pr_crit("Unexpected close, not stopping watchdog!\n");
548 		hpwdt_ping();
549 	}
550 
551 	expect_release = 0;
552 
553 	/* /dev/watchdog is being closed, make sure it can be re-opened */
554 	clear_bit(0, &hpwdt_is_open);
555 
556 	return 0;
557 }
558 
559 static ssize_t hpwdt_write(struct file *file, const char __user *data,
560 	size_t len, loff_t *ppos)
561 {
562 	/* See if we got the magic character 'V' and reload the timer */
563 	if (len) {
564 		if (!nowayout) {
565 			size_t i;
566 
567 			/* note: just in case someone wrote the magic character
568 			 * five months ago... */
569 			expect_release = 0;
570 
571 			/* scan to see whether or not we got the magic char. */
572 			for (i = 0; i != len; i++) {
573 				char c;
574 				if (get_user(c, data + i))
575 					return -EFAULT;
576 				if (c == 'V')
577 					expect_release = 42;
578 			}
579 		}
580 
581 		/* someone wrote to us, we should reload the timer */
582 		hpwdt_ping();
583 	}
584 
585 	return len;
586 }
587 
588 static const struct watchdog_info ident = {
589 	.options = WDIOF_SETTIMEOUT |
590 		   WDIOF_KEEPALIVEPING |
591 		   WDIOF_MAGICCLOSE,
592 	.identity = "HPE iLO2+ HW Watchdog Timer",
593 };
594 
595 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
596 	unsigned long arg)
597 {
598 	void __user *argp = (void __user *)arg;
599 	int __user *p = argp;
600 	int new_margin, options;
601 	int ret = -ENOTTY;
602 
603 	switch (cmd) {
604 	case WDIOC_GETSUPPORT:
605 		ret = 0;
606 		if (copy_to_user(argp, &ident, sizeof(ident)))
607 			ret = -EFAULT;
608 		break;
609 
610 	case WDIOC_GETSTATUS:
611 	case WDIOC_GETBOOTSTATUS:
612 		ret = put_user(0, p);
613 		break;
614 
615 	case WDIOC_KEEPALIVE:
616 		hpwdt_ping();
617 		ret = 0;
618 		break;
619 
620 	case WDIOC_SETOPTIONS:
621 		ret = get_user(options, p);
622 		if (ret)
623 			break;
624 
625 		if (options & WDIOS_DISABLECARD)
626 			hpwdt_stop();
627 
628 		if (options & WDIOS_ENABLECARD) {
629 			hpwdt_start();
630 			hpwdt_ping();
631 		}
632 		break;
633 
634 	case WDIOC_SETTIMEOUT:
635 		ret = get_user(new_margin, p);
636 		if (ret)
637 			break;
638 
639 		ret = hpwdt_change_timer(new_margin);
640 		if (ret)
641 			break;
642 
643 		hpwdt_ping();
644 		/* Fall */
645 	case WDIOC_GETTIMEOUT:
646 		ret = put_user(soft_margin, p);
647 		break;
648 
649 	case WDIOC_GETTIMELEFT:
650 		ret = put_user(hpwdt_time_left(), p);
651 		break;
652 	}
653 	return ret;
654 }
655 
656 /*
657  *	Kernel interfaces
658  */
659 static const struct file_operations hpwdt_fops = {
660 	.owner = THIS_MODULE,
661 	.llseek = no_llseek,
662 	.write = hpwdt_write,
663 	.unlocked_ioctl = hpwdt_ioctl,
664 	.open = hpwdt_open,
665 	.release = hpwdt_release,
666 };
667 
668 static struct miscdevice hpwdt_miscdev = {
669 	.minor = WATCHDOG_MINOR,
670 	.name = "watchdog",
671 	.fops = &hpwdt_fops,
672 };
673 
674 /*
675  *	Init & Exit
676  */
677 
678 #ifdef CONFIG_HPWDT_NMI_DECODING
679 #ifdef CONFIG_X86_LOCAL_APIC
680 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
681 {
682 	/*
683 	 * If nmi_watchdog is turned off then we can turn on
684 	 * our nmi decoding capability.
685 	 */
686 	hpwdt_nmi_decoding = 1;
687 }
688 #else
689 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
690 {
691 	dev_warn(&dev->dev, "NMI decoding is disabled. "
692 		"Your kernel does not support a NMI Watchdog.\n");
693 }
694 #endif /* CONFIG_X86_LOCAL_APIC */
695 
696 /*
697  *	dmi_find_icru
698  *
699  *	Routine Description:
700  *	This function checks whether or not we are on an iCRU-based server.
701  *	This check is independent of architecture and needs to be made for
702  *	any ProLiant system.
703  */
704 static void dmi_find_icru(const struct dmi_header *dm, void *dummy)
705 {
706 	struct smbios_proliant_info *smbios_proliant_ptr;
707 
708 	if (dm->type == SMBIOS_ICRU_INFORMATION) {
709 		smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
710 		if (smbios_proliant_ptr->misc_features & 0x01)
711 			is_icru = 1;
712 		if (smbios_proliant_ptr->misc_features & 0x1400)
713 			is_uefi = 1;
714 	}
715 }
716 
717 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
718 {
719 	int retval;
720 
721 	/*
722 	 * On typical CRU-based systems we need to map that service in
723 	 * the BIOS. For 32 bit Operating Systems we need to go through
724 	 * the 32 Bit BIOS Service Directory. For 64 bit Operating
725 	 * Systems we get that service through SMBIOS.
726 	 *
727 	 * On systems that support the new iCRU service all we need to
728 	 * do is call dmi_walk to get the supported flag value and skip
729 	 * the old cru detect code.
730 	 */
731 	dmi_walk(dmi_find_icru, NULL);
732 	if (!is_icru && !is_uefi) {
733 
734 		/*
735 		* We need to map the ROM to get the CRU service.
736 		* For 32 bit Operating Systems we need to go through the 32 Bit
737 		* BIOS Service Directory
738 		* For 64 bit Operating Systems we get that service through SMBIOS.
739 		*/
740 		retval = detect_cru_service();
741 		if (retval < 0) {
742 			dev_warn(&dev->dev,
743 				"Unable to detect the %d Bit CRU Service.\n",
744 				HPWDT_ARCH);
745 			return retval;
746 		}
747 
748 		/*
749 		* We know this is the only CRU call we need to make so lets keep as
750 		* few instructions as possible once the NMI comes in.
751 		*/
752 		cmn_regs.u1.rah = 0x0D;
753 		cmn_regs.u1.ral = 0x02;
754 	}
755 
756 	/*
757 	 * Only one function can register for NMI_UNKNOWN
758 	 */
759 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
760 	if (retval)
761 		goto error;
762 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
763 	if (retval)
764 		goto error1;
765 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
766 	if (retval)
767 		goto error2;
768 
769 	dev_info(&dev->dev,
770 			"HPE Watchdog Timer Driver: NMI decoding initialized"
771 			", allow kernel dump: %s (default = 1/ON)\n",
772 			(allow_kdump == 0) ? "OFF" : "ON");
773 	return 0;
774 
775 error2:
776 	unregister_nmi_handler(NMI_SERR, "hpwdt");
777 error1:
778 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
779 error:
780 	dev_warn(&dev->dev,
781 		"Unable to register a die notifier (err=%d).\n",
782 		retval);
783 	if (cru_rom_addr)
784 		iounmap(cru_rom_addr);
785 	return retval;
786 }
787 
788 static void hpwdt_exit_nmi_decoding(void)
789 {
790 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
791 	unregister_nmi_handler(NMI_SERR, "hpwdt");
792 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
793 	if (cru_rom_addr)
794 		iounmap(cru_rom_addr);
795 }
796 #else /* !CONFIG_HPWDT_NMI_DECODING */
797 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
798 {
799 }
800 
801 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
802 {
803 	return 0;
804 }
805 
806 static void hpwdt_exit_nmi_decoding(void)
807 {
808 }
809 #endif /* CONFIG_HPWDT_NMI_DECODING */
810 
811 static int hpwdt_init_one(struct pci_dev *dev,
812 					const struct pci_device_id *ent)
813 {
814 	int retval;
815 
816 	/*
817 	 * Check if we can do NMI decoding or not
818 	 */
819 	hpwdt_check_nmi_decoding(dev);
820 
821 	/*
822 	 * First let's find out if we are on an iLO2+ server. We will
823 	 * not run on a legacy ASM box.
824 	 * So we only support the G5 ProLiant servers and higher.
825 	 */
826 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
827 	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
828 		dev_warn(&dev->dev,
829 			"This server does not have an iLO2+ ASIC.\n");
830 		return -ENODEV;
831 	}
832 
833 	/*
834 	 * Ignore all auxilary iLO devices with the following PCI ID
835 	 */
836 	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP &&
837 	    dev->subsystem_device == 0x1979)
838 		return -ENODEV;
839 
840 	if (pci_enable_device(dev)) {
841 		dev_warn(&dev->dev,
842 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
843 			ent->vendor, ent->device);
844 		return -ENODEV;
845 	}
846 
847 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
848 	if (!pci_mem_addr) {
849 		dev_warn(&dev->dev,
850 			"Unable to detect the iLO2+ server memory.\n");
851 		retval = -ENOMEM;
852 		goto error_pci_iomap;
853 	}
854 	hpwdt_nmistat	= pci_mem_addr + 0x6e;
855 	hpwdt_timer_reg = pci_mem_addr + 0x70;
856 	hpwdt_timer_con = pci_mem_addr + 0x72;
857 
858 	/* Make sure that timer is disabled until /dev/watchdog is opened */
859 	hpwdt_stop();
860 
861 	/* Make sure that we have a valid soft_margin */
862 	if (hpwdt_change_timer(soft_margin))
863 		hpwdt_change_timer(DEFAULT_MARGIN);
864 
865 	/* Initialize NMI Decoding functionality */
866 	retval = hpwdt_init_nmi_decoding(dev);
867 	if (retval != 0)
868 		goto error_init_nmi_decoding;
869 
870 	retval = misc_register(&hpwdt_miscdev);
871 	if (retval < 0) {
872 		dev_warn(&dev->dev,
873 			"Unable to register miscdev on minor=%d (err=%d).\n",
874 			WATCHDOG_MINOR, retval);
875 		goto error_misc_register;
876 	}
877 
878 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: %s"
879 			", timer margin: %d seconds (nowayout=%d).\n",
880 			HPWDT_VERSION, soft_margin, nowayout);
881 	return 0;
882 
883 error_misc_register:
884 	hpwdt_exit_nmi_decoding();
885 error_init_nmi_decoding:
886 	pci_iounmap(dev, pci_mem_addr);
887 error_pci_iomap:
888 	pci_disable_device(dev);
889 	return retval;
890 }
891 
892 static void hpwdt_exit(struct pci_dev *dev)
893 {
894 	if (!nowayout)
895 		hpwdt_stop();
896 
897 	misc_deregister(&hpwdt_miscdev);
898 	hpwdt_exit_nmi_decoding();
899 	pci_iounmap(dev, pci_mem_addr);
900 	pci_disable_device(dev);
901 }
902 
903 static struct pci_driver hpwdt_driver = {
904 	.name = "hpwdt",
905 	.id_table = hpwdt_devices,
906 	.probe = hpwdt_init_one,
907 	.remove = hpwdt_exit,
908 };
909 
910 MODULE_AUTHOR("Tom Mingarelli");
911 MODULE_DESCRIPTION("hp watchdog driver");
912 MODULE_LICENSE("GPL");
913 MODULE_VERSION(HPWDT_VERSION);
914 
915 module_param(soft_margin, int, 0);
916 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
917 
918 module_param(nowayout, bool, 0);
919 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
920 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
921 
922 #ifdef CONFIG_HPWDT_NMI_DECODING
923 module_param(allow_kdump, int, 0);
924 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
925 #endif /* !CONFIG_HPWDT_NMI_DECODING */
926 
927 module_pci_driver(hpwdt_driver);
928