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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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/device.h>
19 #include <linux/fs.h>
20 #include <linux/init.h>
21 #include <linux/io.h>
22 #include <linux/bitops.h>
23 #include <linux/kernel.h>
24 #include <linux/miscdevice.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/pci.h>
28 #include <linux/pci_ids.h>
29 #include <linux/types.h>
30 #include <linux/uaccess.h>
31 #include <linux/watchdog.h>
32 #ifdef CONFIG_HPWDT_NMI_DECODING
33 #include <linux/dmi.h>
34 #include <linux/spinlock.h>
35 #include <linux/nmi.h>
36 #include <linux/kdebug.h>
37 #include <linux/notifier.h>
38 #include <asm/cacheflush.h>
39 #endif /* CONFIG_HPWDT_NMI_DECODING */
40 #include <asm/nmi.h>
41 
42 #define HPWDT_VERSION			"1.3.1"
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_timer_reg;
56 static unsigned long __iomem *hpwdt_timer_con;
57 
58 static DEFINE_PCI_DEVICE_TABLE(hpwdt_devices) = {
59 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
60 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
61 	{0},			/* terminate list */
62 };
63 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
64 
65 #ifdef CONFIG_HPWDT_NMI_DECODING
66 #define PCI_BIOS32_SD_VALUE		0x5F32335F	/* "_32_" */
67 #define CRU_BIOS_SIGNATURE_VALUE	0x55524324
68 #define PCI_BIOS32_PARAGRAPH_LEN	16
69 #define PCI_ROM_BASE1			0x000F0000
70 #define ROM_SIZE			0x10000
71 
72 struct bios32_service_dir {
73 	u32 signature;
74 	u32 entry_point;
75 	u8 revision;
76 	u8 length;
77 	u8 checksum;
78 	u8 reserved[5];
79 };
80 
81 /* type 212 */
82 struct smbios_cru64_info {
83 	u8 type;
84 	u8 byte_length;
85 	u16 handle;
86 	u32 signature;
87 	u64 physical_address;
88 	u32 double_length;
89 	u32 double_offset;
90 };
91 #define SMBIOS_CRU64_INFORMATION	212
92 
93 /* type 219 */
94 struct smbios_proliant_info {
95 	u8 type;
96 	u8 byte_length;
97 	u16 handle;
98 	u32 power_features;
99 	u32 omega_features;
100 	u32 reserved;
101 	u32 misc_features;
102 };
103 #define SMBIOS_ICRU_INFORMATION		219
104 
105 
106 struct cmn_registers {
107 	union {
108 		struct {
109 			u8 ral;
110 			u8 rah;
111 			u16 rea2;
112 		};
113 		u32 reax;
114 	} u1;
115 	union {
116 		struct {
117 			u8 rbl;
118 			u8 rbh;
119 			u8 reb2l;
120 			u8 reb2h;
121 		};
122 		u32 rebx;
123 	} u2;
124 	union {
125 		struct {
126 			u8 rcl;
127 			u8 rch;
128 			u16 rec2;
129 		};
130 		u32 recx;
131 	} u3;
132 	union {
133 		struct {
134 			u8 rdl;
135 			u8 rdh;
136 			u16 red2;
137 		};
138 		u32 redx;
139 	} u4;
140 
141 	u32 resi;
142 	u32 redi;
143 	u16 rds;
144 	u16 res;
145 	u32 reflags;
146 }  __attribute__((packed));
147 
148 static unsigned int hpwdt_nmi_decoding;
149 static unsigned int allow_kdump = 1;
150 static unsigned int is_icru;
151 static DEFINE_SPINLOCK(rom_lock);
152 static void *cru_rom_addr;
153 static struct cmn_registers cmn_regs;
154 
155 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
156 						unsigned long *pRomEntry);
157 
158 #ifdef CONFIG_X86_32
159 /* --32 Bit Bios------------------------------------------------------------ */
160 
161 #define HPWDT_ARCH	32
162 
163 asm(".text                          \n\t"
164     ".align 4                       \n"
165     "asminline_call:                \n\t"
166     "pushl       %ebp               \n\t"
167     "movl        %esp, %ebp         \n\t"
168     "pusha                          \n\t"
169     "pushf                          \n\t"
170     "push        %es                \n\t"
171     "push        %ds                \n\t"
172     "pop         %es                \n\t"
173     "movl        8(%ebp),%eax       \n\t"
174     "movl        4(%eax),%ebx       \n\t"
175     "movl        8(%eax),%ecx       \n\t"
176     "movl        12(%eax),%edx      \n\t"
177     "movl        16(%eax),%esi      \n\t"
178     "movl        20(%eax),%edi      \n\t"
179     "movl        (%eax),%eax        \n\t"
180     "push        %cs                \n\t"
181     "call        *12(%ebp)          \n\t"
182     "pushf                          \n\t"
183     "pushl       %eax               \n\t"
184     "movl        8(%ebp),%eax       \n\t"
185     "movl        %ebx,4(%eax)       \n\t"
186     "movl        %ecx,8(%eax)       \n\t"
187     "movl        %edx,12(%eax)      \n\t"
188     "movl        %esi,16(%eax)      \n\t"
189     "movl        %edi,20(%eax)      \n\t"
190     "movw        %ds,24(%eax)       \n\t"
191     "movw        %es,26(%eax)       \n\t"
192     "popl        %ebx               \n\t"
193     "movl        %ebx,(%eax)        \n\t"
194     "popl        %ebx               \n\t"
195     "movl        %ebx,28(%eax)      \n\t"
196     "pop         %es                \n\t"
197     "popf                           \n\t"
198     "popa                           \n\t"
199     "leave                          \n\t"
200     "ret                            \n\t"
201     ".previous");
202 
203 
204 /*
205  *	cru_detect
206  *
207  *	Routine Description:
208  *	This function uses the 32-bit BIOS Service Directory record to
209  *	search for a $CRU record.
210  *
211  *	Return Value:
212  *	0        :  SUCCESS
213  *	<0       :  FAILURE
214  */
cru_detect(unsigned long map_entry,unsigned long map_offset)215 static int cru_detect(unsigned long map_entry,
216 	unsigned long map_offset)
217 {
218 	void *bios32_map;
219 	unsigned long *bios32_entrypoint;
220 	unsigned long cru_physical_address;
221 	unsigned long cru_length;
222 	unsigned long physical_bios_base = 0;
223 	unsigned long physical_bios_offset = 0;
224 	int retval = -ENODEV;
225 
226 	bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
227 
228 	if (bios32_map == NULL)
229 		return -ENODEV;
230 
231 	bios32_entrypoint = bios32_map + map_offset;
232 
233 	cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
234 
235 	set_memory_x((unsigned long)bios32_map, 2);
236 	asminline_call(&cmn_regs, bios32_entrypoint);
237 
238 	if (cmn_regs.u1.ral != 0) {
239 		pr_warn("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 & PAGE_MASK,
254 					(cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
255 				retval = 0;
256 			}
257 		}
258 
259 		pr_debug("CRU Base Address:   0x%lx\n", physical_bios_base);
260 		pr_debug("CRU Offset Address: 0x%lx\n", physical_bios_offset);
261 		pr_debug("CRU Length:         0x%lx\n", cru_length);
262 		pr_debug("CRU Mapped Address: %p\n", &cru_rom_addr);
263 	}
264 	iounmap(bios32_map);
265 	return retval;
266 }
267 
268 /*
269  *	bios_checksum
270  */
bios_checksum(const char __iomem * ptr,int len)271 static int bios_checksum(const char __iomem *ptr, int len)
272 {
273 	char sum = 0;
274 	int i;
275 
276 	/*
277 	 * calculate checksum of size bytes. This should add up
278 	 * to zero if we have a valid header.
279 	 */
280 	for (i = 0; i < len; i++)
281 		sum += ptr[i];
282 
283 	return ((sum == 0) && (len > 0));
284 }
285 
286 /*
287  *	bios32_present
288  *
289  *	Routine Description:
290  *	This function finds the 32-bit BIOS Service Directory
291  *
292  *	Return Value:
293  *	0        :  SUCCESS
294  *	<0       :  FAILURE
295  */
bios32_present(const char __iomem * p)296 static int bios32_present(const char __iomem *p)
297 {
298 	struct bios32_service_dir *bios_32_ptr;
299 	int length;
300 	unsigned long map_entry, map_offset;
301 
302 	bios_32_ptr = (struct bios32_service_dir *) p;
303 
304 	/*
305 	 * Search for signature by checking equal to the swizzled value
306 	 * instead of calling another routine to perform a strcmp.
307 	 */
308 	if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
309 		length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
310 		if (bios_checksum(p, length)) {
311 			/*
312 			 * According to the spec, we're looking for the
313 			 * first 4KB-aligned address below the entrypoint
314 			 * listed in the header. The Service Directory code
315 			 * is guaranteed to occupy no more than 2 4KB pages.
316 			 */
317 			map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
318 			map_offset = bios_32_ptr->entry_point - map_entry;
319 
320 			return cru_detect(map_entry, map_offset);
321 		}
322 	}
323 	return -ENODEV;
324 }
325 
detect_cru_service(void)326 static int detect_cru_service(void)
327 {
328 	char __iomem *p, *q;
329 	int rc = -1;
330 
331 	/*
332 	 * Search from 0x0f0000 through 0x0fffff, inclusive.
333 	 */
334 	p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
335 	if (p == NULL)
336 		return -ENOMEM;
337 
338 	for (q = p; q < p + ROM_SIZE; q += 16) {
339 		rc = bios32_present(q);
340 		if (!rc)
341 			break;
342 	}
343 	iounmap(p);
344 	return rc;
345 }
346 /* ------------------------------------------------------------------------- */
347 #endif /* CONFIG_X86_32 */
348 #ifdef CONFIG_X86_64
349 /* --64 Bit Bios------------------------------------------------------------ */
350 
351 #define HPWDT_ARCH	64
352 
353 asm(".text                      \n\t"
354     ".align 4                   \n"
355     "asminline_call:            \n\t"
356     "pushq      %rbp            \n\t"
357     "movq       %rsp, %rbp      \n\t"
358     "pushq      %rax            \n\t"
359     "pushq      %rbx            \n\t"
360     "pushq      %rdx            \n\t"
361     "pushq      %r12            \n\t"
362     "pushq      %r9             \n\t"
363     "movq       %rsi, %r12      \n\t"
364     "movq       %rdi, %r9       \n\t"
365     "movl       4(%r9),%ebx     \n\t"
366     "movl       8(%r9),%ecx     \n\t"
367     "movl       12(%r9),%edx    \n\t"
368     "movl       16(%r9),%esi    \n\t"
369     "movl       20(%r9),%edi    \n\t"
370     "movl       (%r9),%eax      \n\t"
371     "call       *%r12           \n\t"
372     "pushfq                     \n\t"
373     "popq        %r12           \n\t"
374     "movl       %eax, (%r9)     \n\t"
375     "movl       %ebx, 4(%r9)    \n\t"
376     "movl       %ecx, 8(%r9)    \n\t"
377     "movl       %edx, 12(%r9)   \n\t"
378     "movl       %esi, 16(%r9)   \n\t"
379     "movl       %edi, 20(%r9)   \n\t"
380     "movq       %r12, %rax      \n\t"
381     "movl       %eax, 28(%r9)   \n\t"
382     "popq       %r9             \n\t"
383     "popq       %r12            \n\t"
384     "popq       %rdx            \n\t"
385     "popq       %rbx            \n\t"
386     "popq       %rax            \n\t"
387     "leave                      \n\t"
388     "ret                        \n\t"
389     ".previous");
390 
391 /*
392  *	dmi_find_cru
393  *
394  *	Routine Description:
395  *	This function checks whether or not a SMBIOS/DMI record is
396  *	the 64bit CRU info or not
397  */
dmi_find_cru(const struct dmi_header * dm,void * dummy)398 static void dmi_find_cru(const struct dmi_header *dm, void *dummy)
399 {
400 	struct smbios_cru64_info *smbios_cru64_ptr;
401 	unsigned long cru_physical_address;
402 
403 	if (dm->type == SMBIOS_CRU64_INFORMATION) {
404 		smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
405 		if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
406 			cru_physical_address =
407 				smbios_cru64_ptr->physical_address +
408 				smbios_cru64_ptr->double_offset;
409 			cru_rom_addr = ioremap(cru_physical_address,
410 				smbios_cru64_ptr->double_length);
411 			set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
412 				smbios_cru64_ptr->double_length >> PAGE_SHIFT);
413 		}
414 	}
415 }
416 
detect_cru_service(void)417 static int detect_cru_service(void)
418 {
419 	cru_rom_addr = NULL;
420 
421 	dmi_walk(dmi_find_cru, NULL);
422 
423 	/* if cru_rom_addr has been set then we found a CRU service */
424 	return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
425 }
426 /* ------------------------------------------------------------------------- */
427 #endif /* CONFIG_X86_64 */
428 #endif /* CONFIG_HPWDT_NMI_DECODING */
429 
430 /*
431  *	Watchdog operations
432  */
hpwdt_start(void)433 static void hpwdt_start(void)
434 {
435 	reload = SECS_TO_TICKS(soft_margin);
436 	iowrite16(reload, hpwdt_timer_reg);
437 	iowrite8(0x85, hpwdt_timer_con);
438 }
439 
hpwdt_stop(void)440 static void hpwdt_stop(void)
441 {
442 	unsigned long data;
443 
444 	data = ioread8(hpwdt_timer_con);
445 	data &= 0xFE;
446 	iowrite8(data, hpwdt_timer_con);
447 }
448 
hpwdt_ping(void)449 static void hpwdt_ping(void)
450 {
451 	iowrite16(reload, hpwdt_timer_reg);
452 }
453 
hpwdt_change_timer(int new_margin)454 static int hpwdt_change_timer(int new_margin)
455 {
456 	if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
457 		pr_warn("New value passed in is invalid: %d seconds\n",
458 			new_margin);
459 		return -EINVAL;
460 	}
461 
462 	soft_margin = new_margin;
463 	pr_debug("New timer passed in is %d seconds\n", new_margin);
464 	reload = SECS_TO_TICKS(soft_margin);
465 
466 	return 0;
467 }
468 
hpwdt_time_left(void)469 static int hpwdt_time_left(void)
470 {
471 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
472 }
473 
474 #ifdef CONFIG_HPWDT_NMI_DECODING
475 /*
476  *	NMI Handler
477  */
hpwdt_pretimeout(unsigned int ulReason,struct pt_regs * regs)478 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
479 {
480 	unsigned long rom_pl;
481 	static int die_nmi_called;
482 
483 	if (!hpwdt_nmi_decoding)
484 		goto out;
485 
486 	spin_lock_irqsave(&rom_lock, rom_pl);
487 	if (!die_nmi_called && !is_icru)
488 		asminline_call(&cmn_regs, cru_rom_addr);
489 	die_nmi_called = 1;
490 	spin_unlock_irqrestore(&rom_lock, rom_pl);
491 
492 	if (allow_kdump)
493 		hpwdt_stop();
494 
495 	if (!is_icru) {
496 		if (cmn_regs.u1.ral == 0) {
497 			panic("An NMI occurred, "
498 				"but unable to determine source.\n");
499 		}
500 	}
501 	panic("An NMI occurred, please see the Integrated "
502 		"Management Log for details.\n");
503 
504 out:
505 	return NMI_DONE;
506 }
507 #endif /* CONFIG_HPWDT_NMI_DECODING */
508 
509 /*
510  *	/dev/watchdog handling
511  */
hpwdt_open(struct inode * inode,struct file * file)512 static int hpwdt_open(struct inode *inode, struct file *file)
513 {
514 	/* /dev/watchdog can only be opened once */
515 	if (test_and_set_bit(0, &hpwdt_is_open))
516 		return -EBUSY;
517 
518 	/* Start the watchdog */
519 	hpwdt_start();
520 	hpwdt_ping();
521 
522 	return nonseekable_open(inode, file);
523 }
524 
hpwdt_release(struct inode * inode,struct file * file)525 static int hpwdt_release(struct inode *inode, struct file *file)
526 {
527 	/* Stop the watchdog */
528 	if (expect_release == 42) {
529 		hpwdt_stop();
530 	} else {
531 		pr_crit("Unexpected close, not stopping watchdog!\n");
532 		hpwdt_ping();
533 	}
534 
535 	expect_release = 0;
536 
537 	/* /dev/watchdog is being closed, make sure it can be re-opened */
538 	clear_bit(0, &hpwdt_is_open);
539 
540 	return 0;
541 }
542 
hpwdt_write(struct file * file,const char __user * data,size_t len,loff_t * ppos)543 static ssize_t hpwdt_write(struct file *file, const char __user *data,
544 	size_t len, loff_t *ppos)
545 {
546 	/* See if we got the magic character 'V' and reload the timer */
547 	if (len) {
548 		if (!nowayout) {
549 			size_t i;
550 
551 			/* note: just in case someone wrote the magic character
552 			 * five months ago... */
553 			expect_release = 0;
554 
555 			/* scan to see whether or not we got the magic char. */
556 			for (i = 0; i != len; i++) {
557 				char c;
558 				if (get_user(c, data + i))
559 					return -EFAULT;
560 				if (c == 'V')
561 					expect_release = 42;
562 			}
563 		}
564 
565 		/* someone wrote to us, we should reload the timer */
566 		hpwdt_ping();
567 	}
568 
569 	return len;
570 }
571 
572 static const struct watchdog_info ident = {
573 	.options = WDIOF_SETTIMEOUT |
574 		   WDIOF_KEEPALIVEPING |
575 		   WDIOF_MAGICCLOSE,
576 	.identity = "HP iLO2+ HW Watchdog Timer",
577 };
578 
hpwdt_ioctl(struct file * file,unsigned int cmd,unsigned long arg)579 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
580 	unsigned long arg)
581 {
582 	void __user *argp = (void __user *)arg;
583 	int __user *p = argp;
584 	int new_margin;
585 	int ret = -ENOTTY;
586 
587 	switch (cmd) {
588 	case WDIOC_GETSUPPORT:
589 		ret = 0;
590 		if (copy_to_user(argp, &ident, sizeof(ident)))
591 			ret = -EFAULT;
592 		break;
593 
594 	case WDIOC_GETSTATUS:
595 	case WDIOC_GETBOOTSTATUS:
596 		ret = put_user(0, p);
597 		break;
598 
599 	case WDIOC_KEEPALIVE:
600 		hpwdt_ping();
601 		ret = 0;
602 		break;
603 
604 	case WDIOC_SETTIMEOUT:
605 		ret = get_user(new_margin, p);
606 		if (ret)
607 			break;
608 
609 		ret = hpwdt_change_timer(new_margin);
610 		if (ret)
611 			break;
612 
613 		hpwdt_ping();
614 		/* Fall */
615 	case WDIOC_GETTIMEOUT:
616 		ret = put_user(soft_margin, p);
617 		break;
618 
619 	case WDIOC_GETTIMELEFT:
620 		ret = put_user(hpwdt_time_left(), p);
621 		break;
622 	}
623 	return ret;
624 }
625 
626 /*
627  *	Kernel interfaces
628  */
629 static const struct file_operations hpwdt_fops = {
630 	.owner = THIS_MODULE,
631 	.llseek = no_llseek,
632 	.write = hpwdt_write,
633 	.unlocked_ioctl = hpwdt_ioctl,
634 	.open = hpwdt_open,
635 	.release = hpwdt_release,
636 };
637 
638 static struct miscdevice hpwdt_miscdev = {
639 	.minor = WATCHDOG_MINOR,
640 	.name = "watchdog",
641 	.fops = &hpwdt_fops,
642 };
643 
644 /*
645  *	Init & Exit
646  */
647 
648 #ifdef CONFIG_HPWDT_NMI_DECODING
649 #ifdef CONFIG_X86_LOCAL_APIC
hpwdt_check_nmi_decoding(struct pci_dev * dev)650 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
651 {
652 	/*
653 	 * If nmi_watchdog is turned off then we can turn on
654 	 * our nmi decoding capability.
655 	 */
656 	hpwdt_nmi_decoding = 1;
657 }
658 #else
hpwdt_check_nmi_decoding(struct pci_dev * dev)659 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
660 {
661 	dev_warn(&dev->dev, "NMI decoding is disabled. "
662 		"Your kernel does not support a NMI Watchdog.\n");
663 }
664 #endif /* CONFIG_X86_LOCAL_APIC */
665 
666 /*
667  *	dmi_find_icru
668  *
669  *	Routine Description:
670  *	This function checks whether or not we are on an iCRU-based server.
671  *	This check is independent of architecture and needs to be made for
672  *	any ProLiant system.
673  */
dmi_find_icru(const struct dmi_header * dm,void * dummy)674 static void dmi_find_icru(const struct dmi_header *dm, void *dummy)
675 {
676 	struct smbios_proliant_info *smbios_proliant_ptr;
677 
678 	if (dm->type == SMBIOS_ICRU_INFORMATION) {
679 		smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
680 		if (smbios_proliant_ptr->misc_features & 0x01)
681 			is_icru = 1;
682 	}
683 }
684 
hpwdt_init_nmi_decoding(struct pci_dev * dev)685 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
686 {
687 	int retval;
688 
689 	/*
690 	 * On typical CRU-based systems we need to map that service in
691 	 * the BIOS. For 32 bit Operating Systems we need to go through
692 	 * the 32 Bit BIOS Service Directory. For 64 bit Operating
693 	 * Systems we get that service through SMBIOS.
694 	 *
695 	 * On systems that support the new iCRU service all we need to
696 	 * do is call dmi_walk to get the supported flag value and skip
697 	 * the old cru detect code.
698 	 */
699 	dmi_walk(dmi_find_icru, NULL);
700 	if (!is_icru) {
701 
702 		/*
703 		* We need to map the ROM to get the CRU service.
704 		* For 32 bit Operating Systems we need to go through the 32 Bit
705 		* BIOS Service Directory
706 		* For 64 bit Operating Systems we get that service through SMBIOS.
707 		*/
708 		retval = detect_cru_service();
709 		if (retval < 0) {
710 			dev_warn(&dev->dev,
711 				"Unable to detect the %d Bit CRU Service.\n",
712 				HPWDT_ARCH);
713 			return retval;
714 		}
715 
716 		/*
717 		* We know this is the only CRU call we need to make so lets keep as
718 		* few instructions as possible once the NMI comes in.
719 		*/
720 		cmn_regs.u1.rah = 0x0D;
721 		cmn_regs.u1.ral = 0x02;
722 	}
723 
724 	/*
725 	 * Only one function can register for NMI_UNKNOWN
726 	 */
727 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
728 	if (retval)
729 		goto error;
730 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
731 	if (retval)
732 		goto error1;
733 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
734 	if (retval)
735 		goto error2;
736 
737 	dev_info(&dev->dev,
738 			"HP Watchdog Timer Driver: NMI decoding initialized"
739 			", allow kernel dump: %s (default = 0/OFF)\n",
740 			(allow_kdump == 0) ? "OFF" : "ON");
741 	return 0;
742 
743 error2:
744 	unregister_nmi_handler(NMI_SERR, "hpwdt");
745 error1:
746 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
747 error:
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 	return retval;
754 }
755 
hpwdt_exit_nmi_decoding(void)756 static void hpwdt_exit_nmi_decoding(void)
757 {
758 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
759 	unregister_nmi_handler(NMI_SERR, "hpwdt");
760 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
761 	if (cru_rom_addr)
762 		iounmap(cru_rom_addr);
763 }
764 #else /* !CONFIG_HPWDT_NMI_DECODING */
hpwdt_check_nmi_decoding(struct pci_dev * dev)765 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
766 {
767 }
768 
hpwdt_init_nmi_decoding(struct pci_dev * dev)769 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
770 {
771 	return 0;
772 }
773 
hpwdt_exit_nmi_decoding(void)774 static void hpwdt_exit_nmi_decoding(void)
775 {
776 }
777 #endif /* CONFIG_HPWDT_NMI_DECODING */
778 
hpwdt_init_one(struct pci_dev * dev,const struct pci_device_id * ent)779 static int hpwdt_init_one(struct pci_dev *dev,
780 					const struct pci_device_id *ent)
781 {
782 	int retval;
783 
784 	/*
785 	 * Check if we can do NMI decoding or not
786 	 */
787 	hpwdt_check_nmi_decoding(dev);
788 
789 	/*
790 	 * First let's find out if we are on an iLO2+ server. We will
791 	 * not run on a legacy ASM box.
792 	 * So we only support the G5 ProLiant servers and higher.
793 	 */
794 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
795 		dev_warn(&dev->dev,
796 			"This server does not have an iLO2+ ASIC.\n");
797 		return -ENODEV;
798 	}
799 
800 	if (pci_enable_device(dev)) {
801 		dev_warn(&dev->dev,
802 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
803 			ent->vendor, ent->device);
804 		return -ENODEV;
805 	}
806 
807 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
808 	if (!pci_mem_addr) {
809 		dev_warn(&dev->dev,
810 			"Unable to detect the iLO2+ server memory.\n");
811 		retval = -ENOMEM;
812 		goto error_pci_iomap;
813 	}
814 	hpwdt_timer_reg = pci_mem_addr + 0x70;
815 	hpwdt_timer_con = pci_mem_addr + 0x72;
816 
817 	/* Make sure that timer is disabled until /dev/watchdog is opened */
818 	hpwdt_stop();
819 
820 	/* Make sure that we have a valid soft_margin */
821 	if (hpwdt_change_timer(soft_margin))
822 		hpwdt_change_timer(DEFAULT_MARGIN);
823 
824 	/* Initialize NMI Decoding functionality */
825 	retval = hpwdt_init_nmi_decoding(dev);
826 	if (retval != 0)
827 		goto error_init_nmi_decoding;
828 
829 	retval = misc_register(&hpwdt_miscdev);
830 	if (retval < 0) {
831 		dev_warn(&dev->dev,
832 			"Unable to register miscdev on minor=%d (err=%d).\n",
833 			WATCHDOG_MINOR, retval);
834 		goto error_misc_register;
835 	}
836 
837 	dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
838 			", timer margin: %d seconds (nowayout=%d).\n",
839 			HPWDT_VERSION, soft_margin, nowayout);
840 	return 0;
841 
842 error_misc_register:
843 	hpwdt_exit_nmi_decoding();
844 error_init_nmi_decoding:
845 	pci_iounmap(dev, pci_mem_addr);
846 error_pci_iomap:
847 	pci_disable_device(dev);
848 	return retval;
849 }
850 
hpwdt_exit(struct pci_dev * dev)851 static void hpwdt_exit(struct pci_dev *dev)
852 {
853 	if (!nowayout)
854 		hpwdt_stop();
855 
856 	misc_deregister(&hpwdt_miscdev);
857 	hpwdt_exit_nmi_decoding();
858 	pci_iounmap(dev, pci_mem_addr);
859 	pci_disable_device(dev);
860 }
861 
862 static struct pci_driver hpwdt_driver = {
863 	.name = "hpwdt",
864 	.id_table = hpwdt_devices,
865 	.probe = hpwdt_init_one,
866 	.remove = hpwdt_exit,
867 };
868 
869 MODULE_AUTHOR("Tom Mingarelli");
870 MODULE_DESCRIPTION("hp watchdog driver");
871 MODULE_LICENSE("GPL");
872 MODULE_VERSION(HPWDT_VERSION);
873 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
874 
875 module_param(soft_margin, int, 0);
876 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
877 
878 module_param(nowayout, bool, 0);
879 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
880 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
881 
882 #ifdef CONFIG_HPWDT_NMI_DECODING
883 module_param(allow_kdump, int, 0);
884 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
885 #endif /* !CONFIG_HPWDT_NMI_DECODING */
886 
887 module_pci_driver(hpwdt_driver);
888