GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / watchdog / hpwdt.c
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/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/cacheflush.h>
38 #endif /* CONFIG_HPWDT_NMI_DECODING */
39 #include <asm/nmi.h>
40
41 #define HPWDT_VERSION                   "1.3.3"
42 #define SECS_TO_TICKS(secs)             ((secs) * 1000 / 128)
43 #define TICKS_TO_SECS(ticks)            ((ticks) * 128 / 1000)
44 #define HPWDT_MAX_TIMER                 TICKS_TO_SECS(65535)
45 #define DEFAULT_MARGIN                  30
46
47 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
48 static unsigned int reload;                     /* the computed soft_margin */
49 static bool nowayout = WATCHDOG_NOWAYOUT;
50 static char expect_release;
51 static unsigned long hpwdt_is_open;
52
53 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
54 static unsigned long __iomem *hpwdt_nmistat;
55 static unsigned long __iomem *hpwdt_timer_reg;
56 static unsigned long __iomem *hpwdt_timer_con;
57
58 static const struct pci_device_id 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 unsigned int is_uefi;
152 static DEFINE_SPINLOCK(rom_lock);
153 static void *cru_rom_addr;
154 static struct cmn_registers cmn_regs;
155
156 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
157                                                 unsigned long *pRomEntry);
158
159 #ifdef CONFIG_X86_32
160 /* --32 Bit Bios------------------------------------------------------------ */
161
162 #define HPWDT_ARCH      32
163
164 asm(".text                          \n\t"
165     ".align 4                       \n\t"
166     ".globl asminline_call          \n"
167     "asminline_call:                \n\t"
168     "pushl       %ebp               \n\t"
169     "movl        %esp, %ebp         \n\t"
170     "pusha                          \n\t"
171     "pushf                          \n\t"
172     "push        %es                \n\t"
173     "push        %ds                \n\t"
174     "pop         %es                \n\t"
175     "movl        8(%ebp),%eax       \n\t"
176     "movl        4(%eax),%ebx       \n\t"
177     "movl        8(%eax),%ecx       \n\t"
178     "movl        12(%eax),%edx      \n\t"
179     "movl        16(%eax),%esi      \n\t"
180     "movl        20(%eax),%edi      \n\t"
181     "movl        (%eax),%eax        \n\t"
182     "push        %cs                \n\t"
183     "call        *12(%ebp)          \n\t"
184     "pushf                          \n\t"
185     "pushl       %eax               \n\t"
186     "movl        8(%ebp),%eax       \n\t"
187     "movl        %ebx,4(%eax)       \n\t"
188     "movl        %ecx,8(%eax)       \n\t"
189     "movl        %edx,12(%eax)      \n\t"
190     "movl        %esi,16(%eax)      \n\t"
191     "movl        %edi,20(%eax)      \n\t"
192     "movw        %ds,24(%eax)       \n\t"
193     "movw        %es,26(%eax)       \n\t"
194     "popl        %ebx               \n\t"
195     "movl        %ebx,(%eax)        \n\t"
196     "popl        %ebx               \n\t"
197     "movl        %ebx,28(%eax)      \n\t"
198     "pop         %es                \n\t"
199     "popf                           \n\t"
200     "popa                           \n\t"
201     "leave                          \n\t"
202     "ret                            \n\t"
203     ".previous");
204
205
206 /*
207  *      cru_detect
208  *
209  *      Routine Description:
210  *      This function uses the 32-bit BIOS Service Directory record to
211  *      search for a $CRU record.
212  *
213  *      Return Value:
214  *      0        :  SUCCESS
215  *      <0       :  FAILURE
216  */
217 static int cru_detect(unsigned long map_entry,
218         unsigned long map_offset)
219 {
220         void *bios32_map;
221         unsigned long *bios32_entrypoint;
222         unsigned long cru_physical_address;
223         unsigned long cru_length;
224         unsigned long physical_bios_base = 0;
225         unsigned long physical_bios_offset = 0;
226         int retval = -ENODEV;
227
228         bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
229
230         if (bios32_map == NULL)
231                 return -ENODEV;
232
233         bios32_entrypoint = bios32_map + map_offset;
234
235         cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
236
237         set_memory_x((unsigned long)bios32_map, 2);
238         asminline_call(&cmn_regs, bios32_entrypoint);
239
240         if (cmn_regs.u1.ral != 0) {
241                 pr_warn("Call succeeded but with an error: 0x%x\n",
242                         cmn_regs.u1.ral);
243         } else {
244                 physical_bios_base = cmn_regs.u2.rebx;
245                 physical_bios_offset = cmn_regs.u4.redx;
246                 cru_length = cmn_regs.u3.recx;
247                 cru_physical_address =
248                         physical_bios_base + physical_bios_offset;
249
250                 /* If the values look OK, then map it in. */
251                 if ((physical_bios_base + physical_bios_offset)) {
252                         cru_rom_addr =
253                                 ioremap(cru_physical_address, cru_length);
254                         if (cru_rom_addr) {
255                                 set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
256                                         (cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
257                                 retval = 0;
258                         }
259                 }
260
261                 pr_debug("CRU Base Address:   0x%lx\n", physical_bios_base);
262                 pr_debug("CRU Offset Address: 0x%lx\n", physical_bios_offset);
263                 pr_debug("CRU Length:         0x%lx\n", cru_length);
264                 pr_debug("CRU Mapped Address: %p\n", &cru_rom_addr);
265         }
266         iounmap(bios32_map);
267         return retval;
268 }
269
270 /*
271  *      bios_checksum
272  */
273 static int bios_checksum(const char __iomem *ptr, int len)
274 {
275         char sum = 0;
276         int i;
277
278         /*
279          * calculate checksum of size bytes. This should add up
280          * to zero if we have a valid header.
281          */
282         for (i = 0; i < len; i++)
283                 sum += ptr[i];
284
285         return ((sum == 0) && (len > 0));
286 }
287
288 /*
289  *      bios32_present
290  *
291  *      Routine Description:
292  *      This function finds the 32-bit BIOS Service Directory
293  *
294  *      Return Value:
295  *      0        :  SUCCESS
296  *      <0       :  FAILURE
297  */
298 static int bios32_present(const char __iomem *p)
299 {
300         struct bios32_service_dir *bios_32_ptr;
301         int length;
302         unsigned long map_entry, map_offset;
303
304         bios_32_ptr = (struct bios32_service_dir *) p;
305
306         /*
307          * Search for signature by checking equal to the swizzled value
308          * instead of calling another routine to perform a strcmp.
309          */
310         if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
311                 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
312                 if (bios_checksum(p, length)) {
313                         /*
314                          * According to the spec, we're looking for the
315                          * first 4KB-aligned address below the entrypoint
316                          * listed in the header. The Service Directory code
317                          * is guaranteed to occupy no more than 2 4KB pages.
318                          */
319                         map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
320                         map_offset = bios_32_ptr->entry_point - map_entry;
321
322                         return cru_detect(map_entry, map_offset);
323                 }
324         }
325         return -ENODEV;
326 }
327
328 static int detect_cru_service(void)
329 {
330         char __iomem *p, *q;
331         int rc = -1;
332
333         /*
334          * Search from 0x0f0000 through 0x0fffff, inclusive.
335          */
336         p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
337         if (p == NULL)
338                 return -ENOMEM;
339
340         for (q = p; q < p + ROM_SIZE; q += 16) {
341                 rc = bios32_present(q);
342                 if (!rc)
343                         break;
344         }
345         iounmap(p);
346         return rc;
347 }
348 /* ------------------------------------------------------------------------- */
349 #endif /* CONFIG_X86_32 */
350 #ifdef CONFIG_X86_64
351 /* --64 Bit Bios------------------------------------------------------------ */
352
353 #define HPWDT_ARCH      64
354
355 asm(".text                      \n\t"
356     ".align 4                   \n\t"
357     ".globl asminline_call      \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 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 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         iowrite8(0x85, hpwdt_timer_con);
441 }
442
443 static void hpwdt_stop(void)
444 {
445         unsigned long data;
446
447         data = ioread8(hpwdt_timer_con);
448         data &= 0xFE;
449         iowrite8(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                 pr_warn("New value passed in is invalid: %d seconds\n",
461                         new_margin);
462                 return -EINVAL;
463         }
464
465         soft_margin = new_margin;
466         pr_debug("New timer passed in is %d seconds\n", new_margin);
467         reload = SECS_TO_TICKS(soft_margin);
468
469         return 0;
470 }
471
472 static int hpwdt_time_left(void)
473 {
474         return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
475 }
476
477 #ifdef CONFIG_HPWDT_NMI_DECODING
478 static int hpwdt_my_nmi(void)
479 {
480         return ioread8(hpwdt_nmistat) & 0x6;
481 }
482
483 /*
484  *      NMI Handler
485  */
486 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
487 {
488         unsigned long rom_pl;
489         static int die_nmi_called;
490
491         if (!hpwdt_nmi_decoding)
492                 goto out;
493
494         if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi())
495                 return NMI_DONE;
496
497         spin_lock_irqsave(&rom_lock, rom_pl);
498         if (!die_nmi_called && !is_icru && !is_uefi)
499                 asminline_call(&cmn_regs, cru_rom_addr);
500         die_nmi_called = 1;
501         spin_unlock_irqrestore(&rom_lock, rom_pl);
502
503         if (allow_kdump)
504                 hpwdt_stop();
505
506         if (!is_icru && !is_uefi) {
507                 if (cmn_regs.u1.ral == 0) {
508                         panic("An NMI occurred, "
509                                 "but unable to determine source.\n");
510                 }
511         }
512         panic("An NMI occurred. Depending on your system the reason "
513                 "for the NMI is logged in any one of the following "
514                 "resources:\n"
515                 "1. Integrated Management Log (IML)\n"
516                 "2. OA Syslog\n"
517                 "3. OA Forward Progress Log\n"
518                 "4. iLO Event Log");
519
520 out:
521         return NMI_DONE;
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 = "HP 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                         "HP 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_warn(&dev->dev,
828                         "This server does not have an iLO2+ ASIC.\n");
829                 return -ENODEV;
830         }
831
832         /*
833          * Ignore all auxilary iLO devices with the following PCI ID
834          */
835         if (dev->subsystem_device == 0x1979)
836                 return -ENODEV;
837
838         if (pci_enable_device(dev)) {
839                 dev_warn(&dev->dev,
840                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
841                         ent->vendor, ent->device);
842                 return -ENODEV;
843         }
844
845         pci_mem_addr = pci_iomap(dev, 1, 0x80);
846         if (!pci_mem_addr) {
847                 dev_warn(&dev->dev,
848                         "Unable to detect the iLO2+ server memory.\n");
849                 retval = -ENOMEM;
850                 goto error_pci_iomap;
851         }
852         hpwdt_nmistat   = pci_mem_addr + 0x6e;
853         hpwdt_timer_reg = pci_mem_addr + 0x70;
854         hpwdt_timer_con = pci_mem_addr + 0x72;
855
856         /* Make sure that timer is disabled until /dev/watchdog is opened */
857         hpwdt_stop();
858
859         /* Make sure that we have a valid soft_margin */
860         if (hpwdt_change_timer(soft_margin))
861                 hpwdt_change_timer(DEFAULT_MARGIN);
862
863         /* Initialize NMI Decoding functionality */
864         retval = hpwdt_init_nmi_decoding(dev);
865         if (retval != 0)
866                 goto error_init_nmi_decoding;
867
868         retval = misc_register(&hpwdt_miscdev);
869         if (retval < 0) {
870                 dev_warn(&dev->dev,
871                         "Unable to register miscdev on minor=%d (err=%d).\n",
872                         WATCHDOG_MINOR, retval);
873                 goto error_misc_register;
874         }
875
876         dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
877                         ", timer margin: %d seconds (nowayout=%d).\n",
878                         HPWDT_VERSION, soft_margin, nowayout);
879         return 0;
880
881 error_misc_register:
882         hpwdt_exit_nmi_decoding();
883 error_init_nmi_decoding:
884         pci_iounmap(dev, pci_mem_addr);
885 error_pci_iomap:
886         pci_disable_device(dev);
887         return retval;
888 }
889
890 static void hpwdt_exit(struct pci_dev *dev)
891 {
892         if (!nowayout)
893                 hpwdt_stop();
894
895         misc_deregister(&hpwdt_miscdev);
896         hpwdt_exit_nmi_decoding();
897         pci_iounmap(dev, pci_mem_addr);
898         pci_disable_device(dev);
899 }
900
901 static struct pci_driver hpwdt_driver = {
902         .name = "hpwdt",
903         .id_table = hpwdt_devices,
904         .probe = hpwdt_init_one,
905         .remove = hpwdt_exit,
906 };
907
908 MODULE_AUTHOR("Tom Mingarelli");
909 MODULE_DESCRIPTION("hp watchdog driver");
910 MODULE_LICENSE("GPL");
911 MODULE_VERSION(HPWDT_VERSION);
912
913 module_param(soft_margin, int, 0);
914 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
915
916 module_param(nowayout, bool, 0);
917 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
918                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
919
920 #ifdef CONFIG_HPWDT_NMI_DECODING
921 module_param(allow_kdump, int, 0);
922 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
923 #endif /* !CONFIG_HPWDT_NMI_DECODING */
924
925 module_pci_driver(hpwdt_driver);