Merge git://www.linux-watchdog.org/linux-watchdog
[cascardo/linux.git] / drivers / watchdog / hpwdt.c
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/cacheflush.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_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\t"
358     ".type asminline_call, @function \n\t"
359     "asminline_call:            \n\t"
360     FRAME_BEGIN
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     FRAME_END
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 /*
479  *      NMI Handler
480  */
481 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
482 {
483         unsigned long rom_pl;
484         static int die_nmi_called;
485
486         if (!hpwdt_nmi_decoding)
487                 return NMI_DONE;
488
489         spin_lock_irqsave(&rom_lock, rom_pl);
490         if (!die_nmi_called && !is_icru && !is_uefi)
491                 asminline_call(&cmn_regs, cru_rom_addr);
492         die_nmi_called = 1;
493         spin_unlock_irqrestore(&rom_lock, rom_pl);
494
495         if (allow_kdump)
496                 hpwdt_stop();
497
498         if (!is_icru && !is_uefi) {
499                 if (cmn_regs.u1.ral == 0) {
500                         nmi_panic(regs, "An NMI occurred, but unable to determine source.\n");
501                         return NMI_HANDLED;
502                 }
503         }
504         nmi_panic(regs, "An NMI occurred. Depending on your system the reason "
505                 "for the NMI is logged in any one of the following "
506                 "resources:\n"
507                 "1. Integrated Management Log (IML)\n"
508                 "2. OA Syslog\n"
509                 "3. OA Forward Progress Log\n"
510                 "4. iLO Event Log");
511
512         return NMI_HANDLED;
513 }
514 #endif /* CONFIG_HPWDT_NMI_DECODING */
515
516 /*
517  *      /dev/watchdog handling
518  */
519 static int hpwdt_open(struct inode *inode, struct file *file)
520 {
521         /* /dev/watchdog can only be opened once */
522         if (test_and_set_bit(0, &hpwdt_is_open))
523                 return -EBUSY;
524
525         /* Start the watchdog */
526         hpwdt_start();
527         hpwdt_ping();
528
529         return nonseekable_open(inode, file);
530 }
531
532 static int hpwdt_release(struct inode *inode, struct file *file)
533 {
534         /* Stop the watchdog */
535         if (expect_release == 42) {
536                 hpwdt_stop();
537         } else {
538                 pr_crit("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 = "HPE 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, options;
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_SETOPTIONS:
612                 ret = get_user(options, p);
613                 if (ret)
614                         break;
615
616                 if (options & WDIOS_DISABLECARD)
617                         hpwdt_stop();
618
619                 if (options & WDIOS_ENABLECARD) {
620                         hpwdt_start();
621                         hpwdt_ping();
622                 }
623                 break;
624
625         case WDIOC_SETTIMEOUT:
626                 ret = get_user(new_margin, p);
627                 if (ret)
628                         break;
629
630                 ret = hpwdt_change_timer(new_margin);
631                 if (ret)
632                         break;
633
634                 hpwdt_ping();
635                 /* Fall */
636         case WDIOC_GETTIMEOUT:
637                 ret = put_user(soft_margin, p);
638                 break;
639
640         case WDIOC_GETTIMELEFT:
641                 ret = put_user(hpwdt_time_left(), p);
642                 break;
643         }
644         return ret;
645 }
646
647 /*
648  *      Kernel interfaces
649  */
650 static const struct file_operations hpwdt_fops = {
651         .owner = THIS_MODULE,
652         .llseek = no_llseek,
653         .write = hpwdt_write,
654         .unlocked_ioctl = hpwdt_ioctl,
655         .open = hpwdt_open,
656         .release = hpwdt_release,
657 };
658
659 static struct miscdevice hpwdt_miscdev = {
660         .minor = WATCHDOG_MINOR,
661         .name = "watchdog",
662         .fops = &hpwdt_fops,
663 };
664
665 /*
666  *      Init & Exit
667  */
668
669 #ifdef CONFIG_HPWDT_NMI_DECODING
670 #ifdef CONFIG_X86_LOCAL_APIC
671 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
672 {
673         /*
674          * If nmi_watchdog is turned off then we can turn on
675          * our nmi decoding capability.
676          */
677         hpwdt_nmi_decoding = 1;
678 }
679 #else
680 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
681 {
682         dev_warn(&dev->dev, "NMI decoding is disabled. "
683                 "Your kernel does not support a NMI Watchdog.\n");
684 }
685 #endif /* CONFIG_X86_LOCAL_APIC */
686
687 /*
688  *      dmi_find_icru
689  *
690  *      Routine Description:
691  *      This function checks whether or not we are on an iCRU-based server.
692  *      This check is independent of architecture and needs to be made for
693  *      any ProLiant system.
694  */
695 static void dmi_find_icru(const struct dmi_header *dm, void *dummy)
696 {
697         struct smbios_proliant_info *smbios_proliant_ptr;
698
699         if (dm->type == SMBIOS_ICRU_INFORMATION) {
700                 smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
701                 if (smbios_proliant_ptr->misc_features & 0x01)
702                         is_icru = 1;
703                 if (smbios_proliant_ptr->misc_features & 0x408)
704                         is_uefi = 1;
705         }
706 }
707
708 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
709 {
710         int retval;
711
712         /*
713          * On typical CRU-based systems we need to map that service in
714          * the BIOS. For 32 bit Operating Systems we need to go through
715          * the 32 Bit BIOS Service Directory. For 64 bit Operating
716          * Systems we get that service through SMBIOS.
717          *
718          * On systems that support the new iCRU service all we need to
719          * do is call dmi_walk to get the supported flag value and skip
720          * the old cru detect code.
721          */
722         dmi_walk(dmi_find_icru, NULL);
723         if (!is_icru && !is_uefi) {
724
725                 /*
726                 * We need to map the ROM to get the CRU service.
727                 * For 32 bit Operating Systems we need to go through the 32 Bit
728                 * BIOS Service Directory
729                 * For 64 bit Operating Systems we get that service through SMBIOS.
730                 */
731                 retval = detect_cru_service();
732                 if (retval < 0) {
733                         dev_warn(&dev->dev,
734                                 "Unable to detect the %d Bit CRU Service.\n",
735                                 HPWDT_ARCH);
736                         return retval;
737                 }
738
739                 /*
740                 * We know this is the only CRU call we need to make so lets keep as
741                 * few instructions as possible once the NMI comes in.
742                 */
743                 cmn_regs.u1.rah = 0x0D;
744                 cmn_regs.u1.ral = 0x02;
745         }
746
747         /*
748          * Only one function can register for NMI_UNKNOWN
749          */
750         retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
751         if (retval)
752                 goto error;
753         retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
754         if (retval)
755                 goto error1;
756         retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
757         if (retval)
758                 goto error2;
759
760         dev_info(&dev->dev,
761                         "HPE Watchdog Timer Driver: NMI decoding initialized"
762                         ", allow kernel dump: %s (default = 1/ON)\n",
763                         (allow_kdump == 0) ? "OFF" : "ON");
764         return 0;
765
766 error2:
767         unregister_nmi_handler(NMI_SERR, "hpwdt");
768 error1:
769         unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
770 error:
771         dev_warn(&dev->dev,
772                 "Unable to register a die notifier (err=%d).\n",
773                 retval);
774         if (cru_rom_addr)
775                 iounmap(cru_rom_addr);
776         return retval;
777 }
778
779 static void hpwdt_exit_nmi_decoding(void)
780 {
781         unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
782         unregister_nmi_handler(NMI_SERR, "hpwdt");
783         unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
784         if (cru_rom_addr)
785                 iounmap(cru_rom_addr);
786 }
787 #else /* !CONFIG_HPWDT_NMI_DECODING */
788 static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
789 {
790 }
791
792 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
793 {
794         return 0;
795 }
796
797 static void hpwdt_exit_nmi_decoding(void)
798 {
799 }
800 #endif /* CONFIG_HPWDT_NMI_DECODING */
801
802 static int hpwdt_init_one(struct pci_dev *dev,
803                                         const struct pci_device_id *ent)
804 {
805         int retval;
806
807         /*
808          * Check if we can do NMI decoding or not
809          */
810         hpwdt_check_nmi_decoding(dev);
811
812         /*
813          * First let's find out if we are on an iLO2+ server. We will
814          * not run on a legacy ASM box.
815          * So we only support the G5 ProLiant servers and higher.
816          */
817         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
818             dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
819                 dev_warn(&dev->dev,
820                         "This server does not have an iLO2+ ASIC.\n");
821                 return -ENODEV;
822         }
823
824         /*
825          * Ignore all auxilary iLO devices with the following PCI ID
826          */
827         if (dev->subsystem_vendor == PCI_VENDOR_ID_HP &&
828             dev->subsystem_device == 0x1979)
829                 return -ENODEV;
830
831         if (pci_enable_device(dev)) {
832                 dev_warn(&dev->dev,
833                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
834                         ent->vendor, ent->device);
835                 return -ENODEV;
836         }
837
838         pci_mem_addr = pci_iomap(dev, 1, 0x80);
839         if (!pci_mem_addr) {
840                 dev_warn(&dev->dev,
841                         "Unable to detect the iLO2+ server memory.\n");
842                 retval = -ENOMEM;
843                 goto error_pci_iomap;
844         }
845         hpwdt_timer_reg = pci_mem_addr + 0x70;
846         hpwdt_timer_con = pci_mem_addr + 0x72;
847
848         /* Make sure that timer is disabled until /dev/watchdog is opened */
849         hpwdt_stop();
850
851         /* Make sure that we have a valid soft_margin */
852         if (hpwdt_change_timer(soft_margin))
853                 hpwdt_change_timer(DEFAULT_MARGIN);
854
855         /* Initialize NMI Decoding functionality */
856         retval = hpwdt_init_nmi_decoding(dev);
857         if (retval != 0)
858                 goto error_init_nmi_decoding;
859
860         retval = misc_register(&hpwdt_miscdev);
861         if (retval < 0) {
862                 dev_warn(&dev->dev,
863                         "Unable to register miscdev on minor=%d (err=%d).\n",
864                         WATCHDOG_MINOR, retval);
865                 goto error_misc_register;
866         }
867
868         dev_info(&dev->dev, "HPE Watchdog Timer Driver: %s"
869                         ", timer margin: %d seconds (nowayout=%d).\n",
870                         HPWDT_VERSION, soft_margin, nowayout);
871         return 0;
872
873 error_misc_register:
874         hpwdt_exit_nmi_decoding();
875 error_init_nmi_decoding:
876         pci_iounmap(dev, pci_mem_addr);
877 error_pci_iomap:
878         pci_disable_device(dev);
879         return retval;
880 }
881
882 static void hpwdt_exit(struct pci_dev *dev)
883 {
884         if (!nowayout)
885                 hpwdt_stop();
886
887         misc_deregister(&hpwdt_miscdev);
888         hpwdt_exit_nmi_decoding();
889         pci_iounmap(dev, pci_mem_addr);
890         pci_disable_device(dev);
891 }
892
893 static struct pci_driver hpwdt_driver = {
894         .name = "hpwdt",
895         .id_table = hpwdt_devices,
896         .probe = hpwdt_init_one,
897         .remove = hpwdt_exit,
898 };
899
900 MODULE_AUTHOR("Tom Mingarelli");
901 MODULE_DESCRIPTION("hp watchdog driver");
902 MODULE_LICENSE("GPL");
903 MODULE_VERSION(HPWDT_VERSION);
904
905 module_param(soft_margin, int, 0);
906 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
907
908 module_param(nowayout, bool, 0);
909 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
910                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
911
912 #ifdef CONFIG_HPWDT_NMI_DECODING
913 module_param(allow_kdump, int, 0);
914 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
915 #endif /* !CONFIG_HPWDT_NMI_DECODING */
916
917 module_pci_driver(hpwdt_driver);