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>
20 #include <linux/bitops.h>
21 #include <linux/kernel.h>
22 #include <linux/miscdevice.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/pci.h>
26 #include <linux/pci_ids.h>
27 #include <linux/types.h>
28 #include <linux/uaccess.h>
29 #include <linux/watchdog.h>
30 #ifdef CONFIG_HPWDT_NMI_DECODING
31 #include <linux/dmi.h>
32 #include <linux/spinlock.h>
33 #include <linux/nmi.h>
34 #include <linux/kdebug.h>
35 #include <linux/notifier.h>
36 #include <asm/cacheflush.h>
37 #endif /* CONFIG_HPWDT_NMI_DECODING */
39 #define HPWDT_VERSION "1.2.0"
40 #define SECS_TO_TICKS(secs) ((secs) * 1000 / 128)
41 #define TICKS_TO_SECS(ticks) ((ticks) * 128 / 1000)
42 #define HPWDT_MAX_TIMER TICKS_TO_SECS(65535)
43 #define DEFAULT_MARGIN 30
45 static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
46 static unsigned int reload; /* the computed soft_margin */
47 static int nowayout = WATCHDOG_NOWAYOUT;
48 static char expect_release;
49 static unsigned long hpwdt_is_open;
51 static void __iomem *pci_mem_addr; /* the PCI-memory address */
52 static unsigned long __iomem *hpwdt_timer_reg;
53 static unsigned long __iomem *hpwdt_timer_con;
55 static DEFINE_PCI_DEVICE_TABLE(hpwdt_devices) = {
56 { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) }, /* iLO2 */
57 { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) }, /* iLO3 */
58 {0}, /* terminate list */
60 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
62 #ifdef CONFIG_HPWDT_NMI_DECODING
63 #define PCI_BIOS32_SD_VALUE 0x5F32335F /* "_32_" */
64 #define CRU_BIOS_SIGNATURE_VALUE 0x55524324
65 #define PCI_BIOS32_PARAGRAPH_LEN 16
66 #define PCI_ROM_BASE1 0x000F0000
67 #define ROM_SIZE 0x10000
69 struct bios32_service_dir {
79 struct smbios_cru64_info {
88 #define SMBIOS_CRU64_INFORMATION 212
90 struct cmn_registers {
130 } __attribute__((packed));
132 static unsigned int hpwdt_nmi_decoding;
133 static unsigned int allow_kdump;
134 static unsigned int priority; /* hpwdt at end of die_notify list */
135 static DEFINE_SPINLOCK(rom_lock);
136 static void *cru_rom_addr;
137 static struct cmn_registers cmn_regs;
139 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
140 unsigned long *pRomEntry);
143 /* --32 Bit Bios------------------------------------------------------------ */
145 #define HPWDT_ARCH 32
149 "asminline_call: \n\t"
151 "movl %esp, %ebp \n\t"
157 "movl 8(%ebp),%eax \n\t"
158 "movl 4(%eax),%ebx \n\t"
159 "movl 8(%eax),%ecx \n\t"
160 "movl 12(%eax),%edx \n\t"
161 "movl 16(%eax),%esi \n\t"
162 "movl 20(%eax),%edi \n\t"
163 "movl (%eax),%eax \n\t"
165 "call *12(%ebp) \n\t"
168 "movl 8(%ebp),%eax \n\t"
169 "movl %ebx,4(%eax) \n\t"
170 "movl %ecx,8(%eax) \n\t"
171 "movl %edx,12(%eax) \n\t"
172 "movl %esi,16(%eax) \n\t"
173 "movl %edi,20(%eax) \n\t"
174 "movw %ds,24(%eax) \n\t"
175 "movw %es,26(%eax) \n\t"
177 "movl %ebx,(%eax) \n\t"
179 "movl %ebx,28(%eax) \n\t"
191 * Routine Description:
192 * This function uses the 32-bit BIOS Service Directory record to
193 * search for a $CRU record.
199 static int __devinit cru_detect(unsigned long map_entry,
200 unsigned long map_offset)
203 unsigned long *bios32_entrypoint;
204 unsigned long cru_physical_address;
205 unsigned long cru_length;
206 unsigned long physical_bios_base = 0;
207 unsigned long physical_bios_offset = 0;
208 int retval = -ENODEV;
210 bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
212 if (bios32_map == NULL)
215 bios32_entrypoint = bios32_map + map_offset;
217 cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
219 set_memory_x((unsigned long)bios32_map, 2);
220 asminline_call(&cmn_regs, bios32_entrypoint);
222 if (cmn_regs.u1.ral != 0) {
224 "hpwdt: Call succeeded but with an error: 0x%x\n",
227 physical_bios_base = cmn_regs.u2.rebx;
228 physical_bios_offset = cmn_regs.u4.redx;
229 cru_length = cmn_regs.u3.recx;
230 cru_physical_address =
231 physical_bios_base + physical_bios_offset;
233 /* If the values look OK, then map it in. */
234 if ((physical_bios_base + physical_bios_offset)) {
236 ioremap(cru_physical_address, cru_length);
238 set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
239 (cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
244 printk(KERN_DEBUG "hpwdt: CRU Base Address: 0x%lx\n",
246 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
247 physical_bios_offset);
248 printk(KERN_DEBUG "hpwdt: CRU Length: 0x%lx\n",
250 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: %p\n",
260 static int __devinit bios_checksum(const char __iomem *ptr, int len)
266 * calculate checksum of size bytes. This should add up
267 * to zero if we have a valid header.
269 for (i = 0; i < len; i++)
272 return ((sum == 0) && (len > 0));
278 * Routine Description:
279 * This function finds the 32-bit BIOS Service Directory
285 static int __devinit bios32_present(const char __iomem *p)
287 struct bios32_service_dir *bios_32_ptr;
289 unsigned long map_entry, map_offset;
291 bios_32_ptr = (struct bios32_service_dir *) p;
294 * Search for signature by checking equal to the swizzled value
295 * instead of calling another routine to perform a strcmp.
297 if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
298 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
299 if (bios_checksum(p, length)) {
301 * According to the spec, we're looking for the
302 * first 4KB-aligned address below the entrypoint
303 * listed in the header. The Service Directory code
304 * is guaranteed to occupy no more than 2 4KB pages.
306 map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
307 map_offset = bios_32_ptr->entry_point - map_entry;
309 return cru_detect(map_entry, map_offset);
315 static int __devinit detect_cru_service(void)
321 * Search from 0x0f0000 through 0x0fffff, inclusive.
323 p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
327 for (q = p; q < p + ROM_SIZE; q += 16) {
328 rc = bios32_present(q);
335 /* ------------------------------------------------------------------------- */
336 #endif /* CONFIG_X86_32 */
338 /* --64 Bit Bios------------------------------------------------------------ */
340 #define HPWDT_ARCH 64
344 "asminline_call: \n\t"
346 "movq %rsp, %rbp \n\t"
352 "movq %rsi, %r12 \n\t"
353 "movq %rdi, %r9 \n\t"
354 "movl 4(%r9),%ebx \n\t"
355 "movl 8(%r9),%ecx \n\t"
356 "movl 12(%r9),%edx \n\t"
357 "movl 16(%r9),%esi \n\t"
358 "movl 20(%r9),%edi \n\t"
359 "movl (%r9),%eax \n\t"
363 "movl %eax, (%r9) \n\t"
364 "movl %ebx, 4(%r9) \n\t"
365 "movl %ecx, 8(%r9) \n\t"
366 "movl %edx, 12(%r9) \n\t"
367 "movl %esi, 16(%r9) \n\t"
368 "movl %edi, 20(%r9) \n\t"
369 "movq %r12, %rax \n\t"
370 "movl %eax, 28(%r9) \n\t"
383 * Routine Description:
384 * This function checks whether or not a SMBIOS/DMI record is
385 * the 64bit CRU info or not
387 static void __devinit dmi_find_cru(const struct dmi_header *dm, void *dummy)
389 struct smbios_cru64_info *smbios_cru64_ptr;
390 unsigned long cru_physical_address;
392 if (dm->type == SMBIOS_CRU64_INFORMATION) {
393 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
394 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
395 cru_physical_address =
396 smbios_cru64_ptr->physical_address +
397 smbios_cru64_ptr->double_offset;
398 cru_rom_addr = ioremap(cru_physical_address,
399 smbios_cru64_ptr->double_length);
400 set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
401 smbios_cru64_ptr->double_length >> PAGE_SHIFT);
406 static int __devinit detect_cru_service(void)
410 dmi_walk(dmi_find_cru, NULL);
412 /* if cru_rom_addr has been set then we found a CRU service */
413 return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
415 /* ------------------------------------------------------------------------- */
416 #endif /* CONFIG_X86_64 */
417 #endif /* CONFIG_HPWDT_NMI_DECODING */
420 * Watchdog operations
422 static void hpwdt_start(void)
424 reload = SECS_TO_TICKS(soft_margin);
425 iowrite16(reload, hpwdt_timer_reg);
426 iowrite16(0x85, hpwdt_timer_con);
429 static void hpwdt_stop(void)
433 data = ioread16(hpwdt_timer_con);
435 iowrite16(data, hpwdt_timer_con);
438 static void hpwdt_ping(void)
440 iowrite16(reload, hpwdt_timer_reg);
443 static int hpwdt_change_timer(int new_margin)
445 if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
447 "hpwdt: New value passed in is invalid: %d seconds.\n",
452 soft_margin = new_margin;
454 "hpwdt: New timer passed in is %d seconds.\n",
456 reload = SECS_TO_TICKS(soft_margin);
461 static int hpwdt_time_left(void)
463 return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
466 #ifdef CONFIG_HPWDT_NMI_DECODING
470 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
473 unsigned long rom_pl;
474 static int die_nmi_called;
476 if (ulReason != DIE_NMIUNKNOWN)
479 if (!hpwdt_nmi_decoding)
482 spin_lock_irqsave(&rom_lock, rom_pl);
484 asminline_call(&cmn_regs, cru_rom_addr);
486 spin_unlock_irqrestore(&rom_lock, rom_pl);
487 if (cmn_regs.u1.ral == 0) {
488 printk(KERN_WARNING "hpwdt: An NMI occurred, "
489 "but unable to determine source.\n");
493 panic("An NMI occurred, please see the Integrated "
494 "Management Log for details.\n");
499 #endif /* CONFIG_HPWDT_NMI_DECODING */
502 * /dev/watchdog handling
504 static int hpwdt_open(struct inode *inode, struct file *file)
506 /* /dev/watchdog can only be opened once */
507 if (test_and_set_bit(0, &hpwdt_is_open))
510 /* Start the watchdog */
514 return nonseekable_open(inode, file);
517 static int hpwdt_release(struct inode *inode, struct file *file)
519 /* Stop the watchdog */
520 if (expect_release == 42) {
524 "hpwdt: Unexpected close, not stopping watchdog!\n");
530 /* /dev/watchdog is being closed, make sure it can be re-opened */
531 clear_bit(0, &hpwdt_is_open);
536 static ssize_t hpwdt_write(struct file *file, const char __user *data,
537 size_t len, loff_t *ppos)
539 /* See if we got the magic character 'V' and reload the timer */
544 /* note: just in case someone wrote the magic character
545 * five months ago... */
548 /* scan to see whether or not we got the magic char. */
549 for (i = 0; i != len; i++) {
551 if (get_user(c, data + i))
558 /* someone wrote to us, we should reload the timer */
565 static const struct watchdog_info ident = {
566 .options = WDIOF_SETTIMEOUT |
567 WDIOF_KEEPALIVEPING |
569 .identity = "HP iLO2+ HW Watchdog Timer",
572 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
575 void __user *argp = (void __user *)arg;
576 int __user *p = argp;
581 case WDIOC_GETSUPPORT:
583 if (copy_to_user(argp, &ident, sizeof(ident)))
587 case WDIOC_GETSTATUS:
588 case WDIOC_GETBOOTSTATUS:
589 ret = put_user(0, p);
592 case WDIOC_KEEPALIVE:
597 case WDIOC_SETTIMEOUT:
598 ret = get_user(new_margin, p);
602 ret = hpwdt_change_timer(new_margin);
608 case WDIOC_GETTIMEOUT:
609 ret = put_user(soft_margin, p);
612 case WDIOC_GETTIMELEFT:
613 ret = put_user(hpwdt_time_left(), p);
622 static const struct file_operations hpwdt_fops = {
623 .owner = THIS_MODULE,
625 .write = hpwdt_write,
626 .unlocked_ioctl = hpwdt_ioctl,
628 .release = hpwdt_release,
631 static struct miscdevice hpwdt_miscdev = {
632 .minor = WATCHDOG_MINOR,
637 #ifdef CONFIG_HPWDT_NMI_DECODING
638 static struct notifier_block die_notifier = {
639 .notifier_call = hpwdt_pretimeout,
642 #endif /* CONFIG_HPWDT_NMI_DECODING */
648 #ifdef CONFIG_HPWDT_NMI_DECODING
649 #ifdef CONFIG_X86_LOCAL_APIC
650 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
653 * If nmi_watchdog is turned off then we can turn on
654 * our nmi decoding capability.
656 hpwdt_nmi_decoding = 1;
659 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
661 dev_warn(&dev->dev, "NMI decoding is disabled. "
662 "Your kernel does not support a NMI Watchdog.\n");
664 #endif /* CONFIG_X86_LOCAL_APIC */
666 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
671 * We need to map the ROM to get the CRU service.
672 * For 32 bit Operating Systems we need to go through the 32 Bit
673 * BIOS Service Directory
674 * For 64 bit Operating Systems we get that service through SMBIOS.
676 retval = detect_cru_service();
679 "Unable to detect the %d Bit CRU Service.\n",
685 * We know this is the only CRU call we need to make so lets keep as
686 * few instructions as possible once the NMI comes in.
688 cmn_regs.u1.rah = 0x0D;
689 cmn_regs.u1.ral = 0x02;
692 * If the priority is set to 1, then we will be put first on the
693 * die notify list to handle a critical NMI. The default is to
694 * be last so other users of the NMI signal can function.
697 die_notifier.priority = 0x7FFFFFFF;
699 retval = register_die_notifier(&die_notifier);
702 "Unable to register a die notifier (err=%d).\n",
705 iounmap(cru_rom_addr);
709 "HP Watchdog Timer Driver: NMI decoding initialized"
710 ", allow kernel dump: %s (default = 0/OFF)"
711 ", priority: %s (default = 0/LAST).\n",
712 (allow_kdump == 0) ? "OFF" : "ON",
713 (priority == 0) ? "LAST" : "FIRST");
717 static void hpwdt_exit_nmi_decoding(void)
719 unregister_die_notifier(&die_notifier);
721 iounmap(cru_rom_addr);
723 #else /* !CONFIG_HPWDT_NMI_DECODING */
724 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
728 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
733 static void hpwdt_exit_nmi_decoding(void)
736 #endif /* CONFIG_HPWDT_NMI_DECODING */
738 static int __devinit hpwdt_init_one(struct pci_dev *dev,
739 const struct pci_device_id *ent)
744 * Check if we can do NMI decoding or not
746 hpwdt_check_nmi_decoding(dev);
749 * First let's find out if we are on an iLO2+ server. We will
750 * not run on a legacy ASM box.
751 * So we only support the G5 ProLiant servers and higher.
753 if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
755 "This server does not have an iLO2+ ASIC.\n");
759 if (pci_enable_device(dev)) {
761 "Not possible to enable PCI Device: 0x%x:0x%x.\n",
762 ent->vendor, ent->device);
766 pci_mem_addr = pci_iomap(dev, 1, 0x80);
769 "Unable to detect the iLO2+ server memory.\n");
771 goto error_pci_iomap;
773 hpwdt_timer_reg = pci_mem_addr + 0x70;
774 hpwdt_timer_con = pci_mem_addr + 0x72;
776 /* Make sure that we have a valid soft_margin */
777 if (hpwdt_change_timer(soft_margin))
778 hpwdt_change_timer(DEFAULT_MARGIN);
780 /* Initialize NMI Decoding functionality */
781 retval = hpwdt_init_nmi_decoding(dev);
783 goto error_init_nmi_decoding;
785 retval = misc_register(&hpwdt_miscdev);
788 "Unable to register miscdev on minor=%d (err=%d).\n",
789 WATCHDOG_MINOR, retval);
790 goto error_misc_register;
793 dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
794 ", timer margin: %d seconds (nowayout=%d).\n",
795 HPWDT_VERSION, soft_margin, nowayout);
799 hpwdt_exit_nmi_decoding();
800 error_init_nmi_decoding:
801 pci_iounmap(dev, pci_mem_addr);
803 pci_disable_device(dev);
807 static void __devexit hpwdt_exit(struct pci_dev *dev)
812 misc_deregister(&hpwdt_miscdev);
813 hpwdt_exit_nmi_decoding();
814 pci_iounmap(dev, pci_mem_addr);
815 pci_disable_device(dev);
818 static struct pci_driver hpwdt_driver = {
820 .id_table = hpwdt_devices,
821 .probe = hpwdt_init_one,
822 .remove = __devexit_p(hpwdt_exit),
825 static void __exit hpwdt_cleanup(void)
827 pci_unregister_driver(&hpwdt_driver);
830 static int __init hpwdt_init(void)
832 return pci_register_driver(&hpwdt_driver);
835 MODULE_AUTHOR("Tom Mingarelli");
836 MODULE_DESCRIPTION("hp watchdog driver");
837 MODULE_LICENSE("GPL");
838 MODULE_VERSION(HPWDT_VERSION);
839 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
841 module_param(soft_margin, int, 0);
842 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
844 module_param(nowayout, int, 0);
845 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
846 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
848 #ifdef CONFIG_HPWDT_NMI_DECODING
849 module_param(allow_kdump, int, 0);
850 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
852 module_param(priority, int, 0);
853 MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
854 " (default = 0/Last)\n");
855 #endif /* !CONFIG_HPWDT_NMI_DECODING */
857 module_init(hpwdt_init);
858 module_exit(hpwdt_cleanup);