5 * SoftDog 0.05: A Software Watchdog Device
7 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
8 * Thomas Mingarelli <thomas.mingarelli@hp.com>
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
16 #include <linux/device.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
21 #include <linux/irq.h>
22 #include <linux/kernel.h>
23 #include <linux/miscdevice.h>
25 #include <linux/module.h>
26 #include <linux/kdebug.h>
27 #include <linux/moduleparam.h>
28 #include <linux/notifier.h>
29 #include <linux/pci.h>
30 #include <linux/pci_ids.h>
31 #include <linux/reboot.h>
32 #include <linux/sched.h>
33 #include <linux/timer.h>
34 #include <linux/types.h>
35 #include <linux/uaccess.h>
36 #include <linux/watchdog.h>
37 #include <linux/dmi.h>
38 #include <linux/efi.h>
39 #include <linux/string.h>
40 #include <linux/bootmem.h>
41 #include <linux/slab.h>
44 #include <asm/kdebug.h>
46 #define PCI_BIOS32_SD_VALUE 0x5F32335F /* "_32_" */
47 #define CRU_BIOS_SIGNATURE_VALUE 0x55524324
48 #define PCI_BIOS32_PARAGRAPH_LEN 16
49 #define PCI_ROM_BASE1 0x000F0000
50 #define ROM_SIZE 0x10000
52 struct bios32_service_dir {
62 * smbios_entry_point - defines SMBIOS entry point structure
64 * anchor[4] - anchor string (_SM_)
65 * checksum - checksum of the entry point structure
66 * length - length of the entry point structure
67 * major_ver - major version (02h for revision 2.1)
68 * minor_ver - minor version (01h for revision 2.1)
69 * max_struct_size - size of the largest SMBIOS structure
70 * revision - entry point structure revision implemented
71 * formatted_area[5] - reserved
72 * intermediate_anchor[5] - intermediate anchor string (_DMI_)
73 * intermediate_checksum - intermediate checksum
74 * table_length - structure table length
75 * table_address - structure table address
76 * table_num_structs - number of SMBIOS structures present
77 * bcd_revision - BCD revision
79 struct smbios_entry_point {
88 u8 intermediate_anchor[5];
89 u8 intermediate_checksum;
92 u16 table_num_structs;
97 struct smbios_cru64_info {
102 u64 physical_address;
106 #define SMBIOS_CRU64_INFORMATION 212
108 struct cmn_registers {
148 } __attribute__((packed));
150 #define DEFAULT_MARGIN 30
151 static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
152 static unsigned int reload; /* the computed soft_margin */
153 static int nowayout = WATCHDOG_NOWAYOUT;
154 static char expect_release;
155 static unsigned long hpwdt_is_open;
157 static void __iomem *pci_mem_addr; /* the PCI-memory address */
158 static unsigned long __iomem *hpwdt_timer_reg;
159 static unsigned long __iomem *hpwdt_timer_con;
161 static DEFINE_SPINLOCK(rom_lock);
163 static void *cru_rom_addr;
165 static struct cmn_registers cmn_regs;
167 static struct pci_device_id hpwdt_devices[] = {
169 .vendor = PCI_VENDOR_ID_COMPAQ,
171 .subvendor = PCI_ANY_ID,
172 .subdevice = PCI_ANY_ID,
174 {0}, /* terminate list */
176 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
181 static int __devinit bios_checksum(const char __iomem *ptr, int len)
187 * calculate checksum of size bytes. This should add up
188 * to zero if we have a valid header.
190 for (i = 0; i < len; i++)
193 return ((sum == 0) && (len > 0));
196 #ifndef CONFIG_X86_64
197 /* --32 Bit Bios------------------------------------------------------------ */
199 #define HPWDT_ARCH 32
201 asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
202 unsigned long *pRomEntry)
204 asm("pushl %ebp \n\t"
205 "movl %esp, %ebp \n\t"
211 "movl 8(%ebp),%eax \n\t"
212 "movl 4(%eax),%ebx \n\t"
213 "movl 8(%eax),%ecx \n\t"
214 "movl 12(%eax),%edx \n\t"
215 "movl 16(%eax),%esi \n\t"
216 "movl 20(%eax),%edi \n\t"
217 "movl (%eax),%eax \n\t"
219 "call *12(%ebp) \n\t"
222 "movl 8(%ebp),%eax \n\t"
223 "movl %ebx,4(%eax) \n\t"
224 "movl %ecx,8(%eax) \n\t"
225 "movl %edx,12(%eax) \n\t"
226 "movl %esi,16(%eax) \n\t"
227 "movl %edi,20(%eax) \n\t"
228 "movw %ds,24(%eax) \n\t"
229 "movw %es,26(%eax) \n\t"
231 "movl %ebx,(%eax) \n\t"
233 "movl %ebx,28(%eax) \n\t"
243 * Routine Description:
244 * This function uses the 32-bit BIOS Service Directory record to
245 * search for a $CRU record.
251 static int __devinit cru_detect(unsigned long map_entry,
252 unsigned long map_offset)
255 unsigned long *bios32_entrypoint;
256 unsigned long cru_physical_address;
257 unsigned long cru_length;
258 unsigned long physical_bios_base = 0;
259 unsigned long physical_bios_offset = 0;
260 int retval = -ENODEV;
262 bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
264 if (bios32_map == NULL)
267 bios32_entrypoint = bios32_map + map_offset;
269 cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
271 asminline_call(&cmn_regs, bios32_entrypoint);
273 if (cmn_regs.u1.ral != 0) {
275 "hpwdt: Call succeeded but with an error: 0x%x\n",
278 physical_bios_base = cmn_regs.u2.rebx;
279 physical_bios_offset = cmn_regs.u4.redx;
280 cru_length = cmn_regs.u3.recx;
281 cru_physical_address =
282 physical_bios_base + physical_bios_offset;
284 /* If the values look OK, then map it in. */
285 if ((physical_bios_base + physical_bios_offset)) {
287 ioremap(cru_physical_address, cru_length);
292 printk(KERN_DEBUG "hpwdt: CRU Base Address: 0x%lx\n",
294 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
295 physical_bios_offset);
296 printk(KERN_DEBUG "hpwdt: CRU Length: 0x%lx\n",
298 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
299 (unsigned int)&cru_rom_addr);
308 * Routine Description:
309 * This function finds the 32-bit BIOS Service Directory
315 static int __devinit bios32_present(const char __iomem *p)
317 struct bios32_service_dir *bios_32_ptr;
319 unsigned long map_entry, map_offset;
321 bios_32_ptr = (struct bios32_service_dir *) p;
324 * Search for signature by checking equal to the swizzled value
325 * instead of calling another routine to perform a strcmp.
327 if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
328 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
329 if (bios_checksum(p, length)) {
331 * According to the spec, we're looking for the
332 * first 4KB-aligned address below the entrypoint
333 * listed in the header. The Service Directory code
334 * is guaranteed to occupy no more than 2 4KB pages.
336 map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
337 map_offset = bios_32_ptr->entry_point - map_entry;
339 return cru_detect(map_entry, map_offset);
345 static int __devinit detect_cru_service(void)
351 * Search from 0x0f0000 through 0x0fffff, inclusive.
353 p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
357 for (q = p; q < p + ROM_SIZE; q += 16) {
358 rc = bios32_present(q);
367 /* --64 Bit Bios------------------------------------------------------------ */
369 #define HPWDT_ARCH 64
371 asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
372 unsigned long *pRomEntry)
374 asm("pushq %rbp \n\t"
375 "movq %rsp, %rbp \n\t"
381 "movq %rsi, %r12 \n\t"
382 "movq %rdi, %r9 \n\t"
383 "movl 4(%r9),%ebx \n\t"
384 "movl 8(%r9),%ecx \n\t"
385 "movl 12(%r9),%edx \n\t"
386 "movl 16(%r9),%esi \n\t"
387 "movl 20(%r9),%edi \n\t"
388 "movl (%r9),%eax \n\t"
393 "movl %eax, (%r9) \n\t"
394 "movl %ebx, 4(%r9) \n\t"
395 "movl %ecx, 8(%r9) \n\t"
396 "movl %edx, 12(%r9) \n\t"
397 "movl %esi, 16(%r9) \n\t"
398 "movl %edi, 20(%r9) \n\t"
399 "movq %r12, %rax \n\t"
400 "movl %eax, 28(%r9) \n\t"
412 * Routine Description:
413 * This function checks wether or not a SMBIOS/DMI record is
414 * the 64bit CRU info or not
417 * 0 : SUCCESS - if record found
418 * <0 : FAILURE - if record not found
420 static void __devinit dmi_find_cru(const struct dmi_header *dm)
422 struct smbios_cru64_info *smbios_cru64_ptr;
423 unsigned long cru_physical_address;
425 if (dm->type == SMBIOS_CRU64_INFORMATION) {
426 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
427 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
428 cru_physical_address =
429 smbios_cru64_ptr->physical_address +
430 smbios_cru64_ptr->double_offset;
431 cru_rom_addr = ioremap(cru_physical_address,
432 smbios_cru64_ptr->double_length);
440 * Routine Description:
441 * Decode the SMBIOS/DMI table and check if we have a 64bit CRU record
444 * We have to be cautious here. We have seen BIOSes with DMI pointers
445 * pointing to completely the wrong place for example
447 static void __devinit dmi_table(u8 *buf, int len, int num,
448 void (*decode)(const struct dmi_header *))
454 * Stop when we see all the items the table claimed to have
455 * OR we run off the end of the table (also happens)
457 while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
458 const struct dmi_header *dm = (const struct dmi_header *)data;
461 * We want to know the total length (formated area and strings)
462 * before decoding to make sure we won't run off the table in
463 * dmi_decode or dmi_string
466 while ((data - buf < len - 1) && (data[0] || data[1]))
468 if (data - buf < len - 1)
478 * Routine Description:
479 * This function parses the SMBIOS entry point table to retrieve
480 * the 64 bit CRU Service.
486 static int __devinit smbios_present(const char __iomem *p)
488 struct smbios_entry_point *eps =
489 (struct smbios_entry_point *) p;
493 /* check if we have indeed the SMBIOS table entry point */
494 if ((strncmp((char *)eps->anchor, "_SM_",
495 sizeof(eps->anchor))) == 0) {
496 length = eps->length;
498 /* SMBIOS v2.1 implementation might use 0x1e */
499 if ((length == 0x1e) &&
500 (eps->major_ver == 2) &&
501 (eps->minor_ver == 1))
506 * - SMBIOS checksum must be 0
507 * - intermediate anchor should be _DMI_
508 * - intermediate checksum should be 0
510 if ((bios_checksum(p, length)) &&
511 (strncmp((char *)eps->intermediate_anchor, "_DMI_",
512 sizeof(eps->intermediate_anchor)) == 0) &&
513 (bios_checksum(p+0x10, 15))) {
514 buf = ioremap(eps->table_address, eps->table_length);
519 /* Scan the DMI table for the 64 bit CRU service */
520 dmi_table(buf, eps->table_length,
521 eps->table_num_structs, dmi_find_cru);
531 static void __devinit smbios_scan_machine(void)
536 if (efi.smbios == EFI_INVALID_TABLE_ADDR)
539 p = ioremap(efi.smbios, 32);
547 * Search from 0x0f0000 through 0x0fffff, inclusive.
549 p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
553 for (q = p; q < p + ROM_SIZE; q += 16)
554 if (!smbios_present(q))
561 static int __devinit detect_cru_service(void)
565 smbios_scan_machine(); /* will become dmi_walk(dmi_find_cru); */
567 /* if cru_rom_addr has been set then we found a CRU service */
568 return ((cru_rom_addr != NULL)? 0: -ENODEV);
571 /* ------------------------------------------------------------------------- */
578 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
581 static unsigned long rom_pl;
582 static int die_nmi_called;
584 if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
587 spin_lock_irqsave(&rom_lock, rom_pl);
589 asminline_call(&cmn_regs, cru_rom_addr);
591 spin_unlock_irqrestore(&rom_lock, rom_pl);
592 if (cmn_regs.u1.ral == 0) {
593 printk(KERN_WARNING "hpwdt: An NMI occurred, "
594 "but unable to determine source.\n");
596 panic("An NMI occurred, please see the Integrated "
597 "Management Log for details.\n");
604 * Watchdog operations
606 static void hpwdt_start(void)
608 reload = (soft_margin * 1000) / 128;
609 iowrite16(reload, hpwdt_timer_reg);
610 iowrite16(0x85, hpwdt_timer_con);
613 static void hpwdt_stop(void)
617 data = ioread16(hpwdt_timer_con);
619 iowrite16(data, hpwdt_timer_con);
622 static void hpwdt_ping(void)
624 iowrite16(reload, hpwdt_timer_reg);
627 static int hpwdt_change_timer(int new_margin)
629 /* Arbitrary, can't find the card's limits */
630 if (new_margin < 30 || new_margin > 600) {
632 "hpwdt: New value passed in is invalid: %d seconds.\n",
637 soft_margin = new_margin;
639 "hpwdt: New timer passed in is %d seconds.\n",
641 reload = (soft_margin * 1000) / 128;
647 * /dev/watchdog handling
649 static int hpwdt_open(struct inode *inode, struct file *file)
651 /* /dev/watchdog can only be opened once */
652 if (test_and_set_bit(0, &hpwdt_is_open))
655 /* Start the watchdog */
659 return nonseekable_open(inode, file);
662 static int hpwdt_release(struct inode *inode, struct file *file)
664 /* Stop the watchdog */
665 if (expect_release == 42) {
669 "hpwdt: Unexpected close, not stopping watchdog!\n");
675 /* /dev/watchdog is being closed, make sure it can be re-opened */
676 clear_bit(0, &hpwdt_is_open);
681 static ssize_t hpwdt_write(struct file *file, const char __user *data,
682 size_t len, loff_t *ppos)
684 /* See if we got the magic character 'V' and reload the timer */
689 /* note: just in case someone wrote the magic character
690 * five months ago... */
693 /* scan to see whether or not we got the magic char. */
694 for (i = 0; i != len; i++) {
696 if (get_user(c, data+i))
703 /* someone wrote to us, we should reload the timer */
710 static struct watchdog_info ident = {
711 .options = WDIOF_SETTIMEOUT |
712 WDIOF_KEEPALIVEPING |
714 .identity = "HP iLO2 HW Watchdog Timer",
717 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
720 void __user *argp = (void __user *)arg;
721 int __user *p = argp;
726 case WDIOC_GETSUPPORT:
728 if (copy_to_user(argp, &ident, sizeof(ident)))
732 case WDIOC_GETSTATUS:
733 case WDIOC_GETBOOTSTATUS:
734 ret = put_user(0, p);
737 case WDIOC_KEEPALIVE:
742 case WDIOC_SETTIMEOUT:
743 ret = get_user(new_margin, p);
747 ret = hpwdt_change_timer(new_margin);
753 case WDIOC_GETTIMEOUT:
754 ret = put_user(soft_margin, p);
763 static struct file_operations hpwdt_fops = {
764 .owner = THIS_MODULE,
766 .write = hpwdt_write,
767 .unlocked_ioctl = hpwdt_ioctl,
769 .release = hpwdt_release,
772 static struct miscdevice hpwdt_miscdev = {
773 .minor = WATCHDOG_MINOR,
778 static struct notifier_block die_notifier = {
779 .notifier_call = hpwdt_pretimeout,
780 .priority = 0x7FFFFFFF,
787 static int __devinit hpwdt_init_one(struct pci_dev *dev,
788 const struct pci_device_id *ent)
793 * First let's find out if we are on an iLO2 server. We will
794 * not run on a legacy ASM box.
796 if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
798 "This server does not have an iLO2 ASIC.\n");
802 if (pci_enable_device(dev)) {
804 "Not possible to enable PCI Device: 0x%x:0x%x.\n",
805 ent->vendor, ent->device);
809 pci_mem_addr = pci_iomap(dev, 1, 0x80);
812 "Unable to detect the iLO2 server memory.\n");
814 goto error_pci_iomap;
816 hpwdt_timer_reg = pci_mem_addr + 0x70;
817 hpwdt_timer_con = pci_mem_addr + 0x72;
819 /* Make sure that we have a valid soft_margin */
820 if (hpwdt_change_timer(soft_margin))
821 hpwdt_change_timer(DEFAULT_MARGIN);
824 * We need to map the ROM to get the CRU service.
825 * For 32 bit Operating Systems we need to go through the 32 Bit
826 * BIOS Service Directory
827 * For 64 bit Operating Systems we get that service through SMBIOS.
829 retval = detect_cru_service();
832 "Unable to detect the %d Bit CRU Service.\n",
838 * We know this is the only CRU call we need to make so lets keep as
839 * few instructions as possible once the NMI comes in.
841 cmn_regs.u1.rah = 0x0D;
842 cmn_regs.u1.ral = 0x02;
844 retval = register_die_notifier(&die_notifier);
847 "Unable to register a die notifier (err=%d).\n",
849 goto error_die_notifier;
852 retval = misc_register(&hpwdt_miscdev);
855 "Unable to register miscdev on minor=%d (err=%d).\n",
856 WATCHDOG_MINOR, retval);
857 goto error_misc_register;
861 "hp Watchdog Timer Driver: 1.00"
862 ", timer margin: %d seconds( nowayout=%d).\n",
863 soft_margin, nowayout);
868 unregister_die_notifier(&die_notifier);
871 iounmap(cru_rom_addr);
873 pci_iounmap(dev, pci_mem_addr);
875 pci_disable_device(dev);
879 static void __devexit hpwdt_exit(struct pci_dev *dev)
884 misc_deregister(&hpwdt_miscdev);
885 unregister_die_notifier(&die_notifier);
888 iounmap(cru_rom_addr);
889 pci_iounmap(dev, pci_mem_addr);
890 pci_disable_device(dev);
893 static struct pci_driver hpwdt_driver = {
895 .id_table = hpwdt_devices,
896 .probe = hpwdt_init_one,
897 .remove = __devexit_p(hpwdt_exit),
900 static void __exit hpwdt_cleanup(void)
902 pci_unregister_driver(&hpwdt_driver);
905 static int __init hpwdt_init(void)
907 return pci_register_driver(&hpwdt_driver);
910 MODULE_AUTHOR("Tom Mingarelli");
911 MODULE_DESCRIPTION("hp watchdog driver");
912 MODULE_LICENSE("GPL");
913 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
915 module_param(soft_margin, int, 0);
916 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
918 module_param(nowayout, int, 0);
919 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
920 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
922 module_init(hpwdt_init);
923 module_exit(hpwdt_cleanup);