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 struct smbios_cru64_info {
71 #define SMBIOS_CRU64_INFORMATION 212
73 struct cmn_registers {
113 } __attribute__((packed));
115 #define DEFAULT_MARGIN 30
116 static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
117 static unsigned int reload; /* the computed soft_margin */
118 static int nowayout = WATCHDOG_NOWAYOUT;
119 static char expect_release;
120 static unsigned long hpwdt_is_open;
122 static void __iomem *pci_mem_addr; /* the PCI-memory address */
123 static unsigned long __iomem *hpwdt_timer_reg;
124 static unsigned long __iomem *hpwdt_timer_con;
126 static DEFINE_SPINLOCK(rom_lock);
128 static void *cru_rom_addr;
130 static struct cmn_registers cmn_regs;
132 static struct pci_device_id hpwdt_devices[] = {
134 .vendor = PCI_VENDOR_ID_COMPAQ,
136 .subvendor = PCI_ANY_ID,
137 .subdevice = PCI_ANY_ID,
139 {0}, /* terminate list */
141 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
143 extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs, unsigned long *pRomEntry);
145 #ifndef CONFIG_X86_64
146 /* --32 Bit Bios------------------------------------------------------------ */
148 #define HPWDT_ARCH 32
152 "asminline_call: \n\t"
154 "movl %esp, %ebp \n\t"
160 "movl 8(%ebp),%eax \n\t"
161 "movl 4(%eax),%ebx \n\t"
162 "movl 8(%eax),%ecx \n\t"
163 "movl 12(%eax),%edx \n\t"
164 "movl 16(%eax),%esi \n\t"
165 "movl 20(%eax),%edi \n\t"
166 "movl (%eax),%eax \n\t"
168 "call *12(%ebp) \n\t"
171 "movl 8(%ebp),%eax \n\t"
172 "movl %ebx,4(%eax) \n\t"
173 "movl %ecx,8(%eax) \n\t"
174 "movl %edx,12(%eax) \n\t"
175 "movl %esi,16(%eax) \n\t"
176 "movl %edi,20(%eax) \n\t"
177 "movw %ds,24(%eax) \n\t"
178 "movw %es,26(%eax) \n\t"
180 "movl %ebx,(%eax) \n\t"
182 "movl %ebx,28(%eax) \n\t"
194 * Routine Description:
195 * This function uses the 32-bit BIOS Service Directory record to
196 * search for a $CRU record.
202 static int __devinit cru_detect(unsigned long map_entry,
203 unsigned long map_offset)
206 unsigned long *bios32_entrypoint;
207 unsigned long cru_physical_address;
208 unsigned long cru_length;
209 unsigned long physical_bios_base = 0;
210 unsigned long physical_bios_offset = 0;
211 int retval = -ENODEV;
213 bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
215 if (bios32_map == NULL)
218 bios32_entrypoint = bios32_map + map_offset;
220 cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
222 asminline_call(&cmn_regs, bios32_entrypoint);
224 if (cmn_regs.u1.ral != 0) {
226 "hpwdt: Call succeeded but with an error: 0x%x\n",
229 physical_bios_base = cmn_regs.u2.rebx;
230 physical_bios_offset = cmn_regs.u4.redx;
231 cru_length = cmn_regs.u3.recx;
232 cru_physical_address =
233 physical_bios_base + physical_bios_offset;
235 /* If the values look OK, then map it in. */
236 if ((physical_bios_base + physical_bios_offset)) {
238 ioremap(cru_physical_address, cru_length);
243 printk(KERN_DEBUG "hpwdt: CRU Base Address: 0x%lx\n",
245 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
246 physical_bios_offset);
247 printk(KERN_DEBUG "hpwdt: CRU Length: 0x%lx\n",
249 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
250 (unsigned int)&cru_rom_addr);
259 static int __devinit bios_checksum(const char __iomem *ptr, int len)
265 * calculate checksum of size bytes. This should add up
266 * to zero if we have a valid header.
268 for (i = 0; i < len; i++)
271 return ((sum == 0) && (len > 0));
277 * Routine Description:
278 * This function finds the 32-bit BIOS Service Directory
284 static int __devinit bios32_present(const char __iomem *p)
286 struct bios32_service_dir *bios_32_ptr;
288 unsigned long map_entry, map_offset;
290 bios_32_ptr = (struct bios32_service_dir *) p;
293 * Search for signature by checking equal to the swizzled value
294 * instead of calling another routine to perform a strcmp.
296 if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
297 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
298 if (bios_checksum(p, length)) {
300 * According to the spec, we're looking for the
301 * first 4KB-aligned address below the entrypoint
302 * listed in the header. The Service Directory code
303 * is guaranteed to occupy no more than 2 4KB pages.
305 map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
306 map_offset = bios_32_ptr->entry_point - map_entry;
308 return cru_detect(map_entry, map_offset);
314 static int __devinit detect_cru_service(void)
320 * Search from 0x0f0000 through 0x0fffff, inclusive.
322 p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
326 for (q = p; q < p + ROM_SIZE; q += 16) {
327 rc = bios32_present(q);
336 /* --64 Bit Bios------------------------------------------------------------ */
338 #define HPWDT_ARCH 64
342 "asminline_call: \n\t"
344 "movq %rsp, %rbp \n\t"
350 "movq %rsi, %r12 \n\t"
351 "movq %rdi, %r9 \n\t"
352 "movl 4(%r9),%ebx \n\t"
353 "movl 8(%r9),%ecx \n\t"
354 "movl 12(%r9),%edx \n\t"
355 "movl 16(%r9),%esi \n\t"
356 "movl 20(%r9),%edi \n\t"
357 "movl (%r9),%eax \n\t"
362 "movl %eax, (%r9) \n\t"
363 "movl %ebx, 4(%r9) \n\t"
364 "movl %ecx, 8(%r9) \n\t"
365 "movl %edx, 12(%r9) \n\t"
366 "movl %esi, 16(%r9) \n\t"
367 "movl %edi, 20(%r9) \n\t"
368 "movq %r12, %rax \n\t"
369 "movl %eax, 28(%r9) \n\t"
382 * Routine Description:
383 * This function checks whether or not a SMBIOS/DMI record is
384 * the 64bit CRU info or not
386 static void __devinit dmi_find_cru(const struct dmi_header *dm)
388 struct smbios_cru64_info *smbios_cru64_ptr;
389 unsigned long cru_physical_address;
391 if (dm->type == SMBIOS_CRU64_INFORMATION) {
392 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
393 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
394 cru_physical_address =
395 smbios_cru64_ptr->physical_address +
396 smbios_cru64_ptr->double_offset;
397 cru_rom_addr = ioremap(cru_physical_address,
398 smbios_cru64_ptr->double_length);
403 static int __devinit detect_cru_service(void)
407 dmi_walk(dmi_find_cru);
409 /* if cru_rom_addr has been set then we found a CRU service */
410 return ((cru_rom_addr != NULL)? 0: -ENODEV);
413 /* ------------------------------------------------------------------------- */
420 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
423 static unsigned long rom_pl;
424 static int die_nmi_called;
426 if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
429 spin_lock_irqsave(&rom_lock, rom_pl);
431 asminline_call(&cmn_regs, cru_rom_addr);
433 spin_unlock_irqrestore(&rom_lock, rom_pl);
434 if (cmn_regs.u1.ral == 0) {
435 printk(KERN_WARNING "hpwdt: An NMI occurred, "
436 "but unable to determine source.\n");
438 panic("An NMI occurred, please see the Integrated "
439 "Management Log for details.\n");
446 * Watchdog operations
448 static void hpwdt_start(void)
450 reload = (soft_margin * 1000) / 128;
451 iowrite16(reload, hpwdt_timer_reg);
452 iowrite16(0x85, hpwdt_timer_con);
455 static void hpwdt_stop(void)
459 data = ioread16(hpwdt_timer_con);
461 iowrite16(data, hpwdt_timer_con);
464 static void hpwdt_ping(void)
466 iowrite16(reload, hpwdt_timer_reg);
469 static int hpwdt_change_timer(int new_margin)
471 /* Arbitrary, can't find the card's limits */
472 if (new_margin < 30 || new_margin > 600) {
474 "hpwdt: New value passed in is invalid: %d seconds.\n",
479 soft_margin = new_margin;
481 "hpwdt: New timer passed in is %d seconds.\n",
483 reload = (soft_margin * 1000) / 128;
489 * /dev/watchdog handling
491 static int hpwdt_open(struct inode *inode, struct file *file)
493 /* /dev/watchdog can only be opened once */
494 if (test_and_set_bit(0, &hpwdt_is_open))
497 /* Start the watchdog */
501 return nonseekable_open(inode, file);
504 static int hpwdt_release(struct inode *inode, struct file *file)
506 /* Stop the watchdog */
507 if (expect_release == 42) {
511 "hpwdt: Unexpected close, not stopping watchdog!\n");
517 /* /dev/watchdog is being closed, make sure it can be re-opened */
518 clear_bit(0, &hpwdt_is_open);
523 static ssize_t hpwdt_write(struct file *file, const char __user *data,
524 size_t len, loff_t *ppos)
526 /* See if we got the magic character 'V' and reload the timer */
531 /* note: just in case someone wrote the magic character
532 * five months ago... */
535 /* scan to see whether or not we got the magic char. */
536 for (i = 0; i != len; i++) {
538 if (get_user(c, data+i))
545 /* someone wrote to us, we should reload the timer */
552 static struct watchdog_info ident = {
553 .options = WDIOF_SETTIMEOUT |
554 WDIOF_KEEPALIVEPING |
556 .identity = "HP iLO2 HW Watchdog Timer",
559 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
562 void __user *argp = (void __user *)arg;
563 int __user *p = argp;
568 case WDIOC_GETSUPPORT:
570 if (copy_to_user(argp, &ident, sizeof(ident)))
574 case WDIOC_GETSTATUS:
575 case WDIOC_GETBOOTSTATUS:
576 ret = put_user(0, p);
579 case WDIOC_KEEPALIVE:
584 case WDIOC_SETTIMEOUT:
585 ret = get_user(new_margin, p);
589 ret = hpwdt_change_timer(new_margin);
595 case WDIOC_GETTIMEOUT:
596 ret = put_user(soft_margin, p);
605 static struct file_operations hpwdt_fops = {
606 .owner = THIS_MODULE,
608 .write = hpwdt_write,
609 .unlocked_ioctl = hpwdt_ioctl,
611 .release = hpwdt_release,
614 static struct miscdevice hpwdt_miscdev = {
615 .minor = WATCHDOG_MINOR,
620 static struct notifier_block die_notifier = {
621 .notifier_call = hpwdt_pretimeout,
622 .priority = 0x7FFFFFFF,
629 static int __devinit hpwdt_init_one(struct pci_dev *dev,
630 const struct pci_device_id *ent)
635 * First let's find out if we are on an iLO2 server. We will
636 * not run on a legacy ASM box.
638 if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
640 "This server does not have an iLO2 ASIC.\n");
644 if (pci_enable_device(dev)) {
646 "Not possible to enable PCI Device: 0x%x:0x%x.\n",
647 ent->vendor, ent->device);
651 pci_mem_addr = pci_iomap(dev, 1, 0x80);
654 "Unable to detect the iLO2 server memory.\n");
656 goto error_pci_iomap;
658 hpwdt_timer_reg = pci_mem_addr + 0x70;
659 hpwdt_timer_con = pci_mem_addr + 0x72;
661 /* Make sure that we have a valid soft_margin */
662 if (hpwdt_change_timer(soft_margin))
663 hpwdt_change_timer(DEFAULT_MARGIN);
666 * We need to map the ROM to get the CRU service.
667 * For 32 bit Operating Systems we need to go through the 32 Bit
668 * BIOS Service Directory
669 * For 64 bit Operating Systems we get that service through SMBIOS.
671 retval = detect_cru_service();
674 "Unable to detect the %d Bit CRU Service.\n",
680 * We know this is the only CRU call we need to make so lets keep as
681 * few instructions as possible once the NMI comes in.
683 cmn_regs.u1.rah = 0x0D;
684 cmn_regs.u1.ral = 0x02;
686 retval = register_die_notifier(&die_notifier);
689 "Unable to register a die notifier (err=%d).\n",
691 goto error_die_notifier;
694 retval = misc_register(&hpwdt_miscdev);
697 "Unable to register miscdev on minor=%d (err=%d).\n",
698 WATCHDOG_MINOR, retval);
699 goto error_misc_register;
703 "hp Watchdog Timer Driver: 1.00"
704 ", timer margin: %d seconds( nowayout=%d).\n",
705 soft_margin, nowayout);
710 unregister_die_notifier(&die_notifier);
713 iounmap(cru_rom_addr);
715 pci_iounmap(dev, pci_mem_addr);
717 pci_disable_device(dev);
721 static void __devexit hpwdt_exit(struct pci_dev *dev)
726 misc_deregister(&hpwdt_miscdev);
727 unregister_die_notifier(&die_notifier);
730 iounmap(cru_rom_addr);
731 pci_iounmap(dev, pci_mem_addr);
732 pci_disable_device(dev);
735 static struct pci_driver hpwdt_driver = {
737 .id_table = hpwdt_devices,
738 .probe = hpwdt_init_one,
739 .remove = __devexit_p(hpwdt_exit),
742 static void __exit hpwdt_cleanup(void)
744 pci_unregister_driver(&hpwdt_driver);
747 static int __init hpwdt_init(void)
749 return pci_register_driver(&hpwdt_driver);
752 MODULE_AUTHOR("Tom Mingarelli");
753 MODULE_DESCRIPTION("hp watchdog driver");
754 MODULE_LICENSE("GPL");
755 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
757 module_param(soft_margin, int, 0);
758 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
760 module_param(nowayout, int, 0);
761 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
762 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
764 module_init(hpwdt_init);
765 module_exit(hpwdt_cleanup);