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 #ifndef CONFIG_X86_64
144 /* --32 Bit Bios------------------------------------------------------------ */
146 #define HPWDT_ARCH 32
148 static void asminline_call(struct cmn_registers *pi86Regs,
149 unsigned long *pRomEntry)
151 asm("pushl %ebp \n\t"
152 "movl %esp, %ebp \n\t"
158 "movl 8(%ebp),%eax \n\t"
159 "movl 4(%eax),%ebx \n\t"
160 "movl 8(%eax),%ecx \n\t"
161 "movl 12(%eax),%edx \n\t"
162 "movl 16(%eax),%esi \n\t"
163 "movl 20(%eax),%edi \n\t"
164 "movl (%eax),%eax \n\t"
166 "call *12(%ebp) \n\t"
169 "movl 8(%ebp),%eax \n\t"
170 "movl %ebx,4(%eax) \n\t"
171 "movl %ecx,8(%eax) \n\t"
172 "movl %edx,12(%eax) \n\t"
173 "movl %esi,16(%eax) \n\t"
174 "movl %edi,20(%eax) \n\t"
175 "movw %ds,24(%eax) \n\t"
176 "movw %es,26(%eax) \n\t"
178 "movl %ebx,(%eax) \n\t"
180 "movl %ebx,28(%eax) \n\t"
190 * Routine Description:
191 * This function uses the 32-bit BIOS Service Directory record to
192 * search for a $CRU record.
198 static int __devinit cru_detect(unsigned long map_entry,
199 unsigned long map_offset)
202 unsigned long *bios32_entrypoint;
203 unsigned long cru_physical_address;
204 unsigned long cru_length;
205 unsigned long physical_bios_base = 0;
206 unsigned long physical_bios_offset = 0;
207 int retval = -ENODEV;
209 bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
211 if (bios32_map == NULL)
214 bios32_entrypoint = bios32_map + map_offset;
216 cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
218 asminline_call(&cmn_regs, bios32_entrypoint);
220 if (cmn_regs.u1.ral != 0) {
222 "hpwdt: Call succeeded but with an error: 0x%x\n",
225 physical_bios_base = cmn_regs.u2.rebx;
226 physical_bios_offset = cmn_regs.u4.redx;
227 cru_length = cmn_regs.u3.recx;
228 cru_physical_address =
229 physical_bios_base + physical_bios_offset;
231 /* If the values look OK, then map it in. */
232 if ((physical_bios_base + physical_bios_offset)) {
234 ioremap(cru_physical_address, cru_length);
239 printk(KERN_DEBUG "hpwdt: CRU Base Address: 0x%lx\n",
241 printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
242 physical_bios_offset);
243 printk(KERN_DEBUG "hpwdt: CRU Length: 0x%lx\n",
245 printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
246 (unsigned int)&cru_rom_addr);
255 static int __devinit bios_checksum(const char __iomem *ptr, int len)
261 * calculate checksum of size bytes. This should add up
262 * to zero if we have a valid header.
264 for (i = 0; i < len; i++)
267 return ((sum == 0) && (len > 0));
273 * Routine Description:
274 * This function finds the 32-bit BIOS Service Directory
280 static int __devinit bios32_present(const char __iomem *p)
282 struct bios32_service_dir *bios_32_ptr;
284 unsigned long map_entry, map_offset;
286 bios_32_ptr = (struct bios32_service_dir *) p;
289 * Search for signature by checking equal to the swizzled value
290 * instead of calling another routine to perform a strcmp.
292 if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
293 length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
294 if (bios_checksum(p, length)) {
296 * According to the spec, we're looking for the
297 * first 4KB-aligned address below the entrypoint
298 * listed in the header. The Service Directory code
299 * is guaranteed to occupy no more than 2 4KB pages.
301 map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
302 map_offset = bios_32_ptr->entry_point - map_entry;
304 return cru_detect(map_entry, map_offset);
310 static int __devinit detect_cru_service(void)
316 * Search from 0x0f0000 through 0x0fffff, inclusive.
318 p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
322 for (q = p; q < p + ROM_SIZE; q += 16) {
323 rc = bios32_present(q);
332 /* --64 Bit Bios------------------------------------------------------------ */
334 #define HPWDT_ARCH 64
336 static void asminline_call(struct cmn_registers *pi86Regs,
337 unsigned long *pRomEntry)
339 asm("pushq %rbp \n\t"
340 "movq %rsp, %rbp \n\t"
346 "movq %rsi, %r12 \n\t"
347 "movq %rdi, %r9 \n\t"
348 "movl 4(%r9),%ebx \n\t"
349 "movl 8(%r9),%ecx \n\t"
350 "movl 12(%r9),%edx \n\t"
351 "movl 16(%r9),%esi \n\t"
352 "movl 20(%r9),%edi \n\t"
353 "movl (%r9),%eax \n\t"
358 "movl %eax, (%r9) \n\t"
359 "movl %ebx, 4(%r9) \n\t"
360 "movl %ecx, 8(%r9) \n\t"
361 "movl %edx, 12(%r9) \n\t"
362 "movl %esi, 16(%r9) \n\t"
363 "movl %edi, 20(%r9) \n\t"
364 "movq %r12, %rax \n\t"
365 "movl %eax, 28(%r9) \n\t"
377 * Routine Description:
378 * This function checks whether or not a SMBIOS/DMI record is
379 * the 64bit CRU info or not
381 static void __devinit dmi_find_cru(const struct dmi_header *dm)
383 struct smbios_cru64_info *smbios_cru64_ptr;
384 unsigned long cru_physical_address;
386 if (dm->type == SMBIOS_CRU64_INFORMATION) {
387 smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
388 if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
389 cru_physical_address =
390 smbios_cru64_ptr->physical_address +
391 smbios_cru64_ptr->double_offset;
392 cru_rom_addr = ioremap(cru_physical_address,
393 smbios_cru64_ptr->double_length);
398 static int __devinit detect_cru_service(void)
402 dmi_walk(dmi_find_cru);
404 /* if cru_rom_addr has been set then we found a CRU service */
405 return ((cru_rom_addr != NULL)? 0: -ENODEV);
408 /* ------------------------------------------------------------------------- */
415 static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
418 static unsigned long rom_pl;
419 static int die_nmi_called;
421 if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
424 spin_lock_irqsave(&rom_lock, rom_pl);
426 asminline_call(&cmn_regs, cru_rom_addr);
428 spin_unlock_irqrestore(&rom_lock, rom_pl);
429 if (cmn_regs.u1.ral == 0) {
430 printk(KERN_WARNING "hpwdt: An NMI occurred, "
431 "but unable to determine source.\n");
433 panic("An NMI occurred, please see the Integrated "
434 "Management Log for details.\n");
441 * Watchdog operations
443 static void hpwdt_start(void)
445 reload = (soft_margin * 1000) / 128;
446 iowrite16(reload, hpwdt_timer_reg);
447 iowrite16(0x85, hpwdt_timer_con);
450 static void hpwdt_stop(void)
454 data = ioread16(hpwdt_timer_con);
456 iowrite16(data, hpwdt_timer_con);
459 static void hpwdt_ping(void)
461 iowrite16(reload, hpwdt_timer_reg);
464 static int hpwdt_change_timer(int new_margin)
466 /* Arbitrary, can't find the card's limits */
467 if (new_margin < 30 || new_margin > 600) {
469 "hpwdt: New value passed in is invalid: %d seconds.\n",
474 soft_margin = new_margin;
476 "hpwdt: New timer passed in is %d seconds.\n",
478 reload = (soft_margin * 1000) / 128;
484 * /dev/watchdog handling
486 static int hpwdt_open(struct inode *inode, struct file *file)
488 /* /dev/watchdog can only be opened once */
489 if (test_and_set_bit(0, &hpwdt_is_open))
492 /* Start the watchdog */
496 return nonseekable_open(inode, file);
499 static int hpwdt_release(struct inode *inode, struct file *file)
501 /* Stop the watchdog */
502 if (expect_release == 42) {
506 "hpwdt: Unexpected close, not stopping watchdog!\n");
512 /* /dev/watchdog is being closed, make sure it can be re-opened */
513 clear_bit(0, &hpwdt_is_open);
518 static ssize_t hpwdt_write(struct file *file, const char __user *data,
519 size_t len, loff_t *ppos)
521 /* See if we got the magic character 'V' and reload the timer */
526 /* note: just in case someone wrote the magic character
527 * five months ago... */
530 /* scan to see whether or not we got the magic char. */
531 for (i = 0; i != len; i++) {
533 if (get_user(c, data+i))
540 /* someone wrote to us, we should reload the timer */
547 static struct watchdog_info ident = {
548 .options = WDIOF_SETTIMEOUT |
549 WDIOF_KEEPALIVEPING |
551 .identity = "HP iLO2 HW Watchdog Timer",
554 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
557 void __user *argp = (void __user *)arg;
558 int __user *p = argp;
563 case WDIOC_GETSUPPORT:
565 if (copy_to_user(argp, &ident, sizeof(ident)))
569 case WDIOC_GETSTATUS:
570 case WDIOC_GETBOOTSTATUS:
571 ret = put_user(0, p);
574 case WDIOC_KEEPALIVE:
579 case WDIOC_SETTIMEOUT:
580 ret = get_user(new_margin, p);
584 ret = hpwdt_change_timer(new_margin);
590 case WDIOC_GETTIMEOUT:
591 ret = put_user(soft_margin, p);
600 static struct file_operations hpwdt_fops = {
601 .owner = THIS_MODULE,
603 .write = hpwdt_write,
604 .unlocked_ioctl = hpwdt_ioctl,
606 .release = hpwdt_release,
609 static struct miscdevice hpwdt_miscdev = {
610 .minor = WATCHDOG_MINOR,
615 static struct notifier_block die_notifier = {
616 .notifier_call = hpwdt_pretimeout,
617 .priority = 0x7FFFFFFF,
624 static int __devinit hpwdt_init_one(struct pci_dev *dev,
625 const struct pci_device_id *ent)
630 * First let's find out if we are on an iLO2 server. We will
631 * not run on a legacy ASM box.
633 if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
635 "This server does not have an iLO2 ASIC.\n");
639 if (pci_enable_device(dev)) {
641 "Not possible to enable PCI Device: 0x%x:0x%x.\n",
642 ent->vendor, ent->device);
646 pci_mem_addr = pci_iomap(dev, 1, 0x80);
649 "Unable to detect the iLO2 server memory.\n");
651 goto error_pci_iomap;
653 hpwdt_timer_reg = pci_mem_addr + 0x70;
654 hpwdt_timer_con = pci_mem_addr + 0x72;
656 /* Make sure that we have a valid soft_margin */
657 if (hpwdt_change_timer(soft_margin))
658 hpwdt_change_timer(DEFAULT_MARGIN);
661 * We need to map the ROM to get the CRU service.
662 * For 32 bit Operating Systems we need to go through the 32 Bit
663 * BIOS Service Directory
664 * For 64 bit Operating Systems we get that service through SMBIOS.
666 retval = detect_cru_service();
669 "Unable to detect the %d Bit CRU Service.\n",
675 * We know this is the only CRU call we need to make so lets keep as
676 * few instructions as possible once the NMI comes in.
678 cmn_regs.u1.rah = 0x0D;
679 cmn_regs.u1.ral = 0x02;
681 retval = register_die_notifier(&die_notifier);
684 "Unable to register a die notifier (err=%d).\n",
686 goto error_die_notifier;
689 retval = misc_register(&hpwdt_miscdev);
692 "Unable to register miscdev on minor=%d (err=%d).\n",
693 WATCHDOG_MINOR, retval);
694 goto error_misc_register;
698 "hp Watchdog Timer Driver: 1.00"
699 ", timer margin: %d seconds( nowayout=%d).\n",
700 soft_margin, nowayout);
705 unregister_die_notifier(&die_notifier);
708 iounmap(cru_rom_addr);
710 pci_iounmap(dev, pci_mem_addr);
712 pci_disable_device(dev);
716 static void __devexit hpwdt_exit(struct pci_dev *dev)
721 misc_deregister(&hpwdt_miscdev);
722 unregister_die_notifier(&die_notifier);
725 iounmap(cru_rom_addr);
726 pci_iounmap(dev, pci_mem_addr);
727 pci_disable_device(dev);
730 static struct pci_driver hpwdt_driver = {
732 .id_table = hpwdt_devices,
733 .probe = hpwdt_init_one,
734 .remove = __devexit_p(hpwdt_exit),
737 static void __exit hpwdt_cleanup(void)
739 pci_unregister_driver(&hpwdt_driver);
742 static int __init hpwdt_init(void)
744 return pci_register_driver(&hpwdt_driver);
747 MODULE_AUTHOR("Tom Mingarelli");
748 MODULE_DESCRIPTION("hp watchdog driver");
749 MODULE_LICENSE("GPL");
750 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
752 module_param(soft_margin, int, 0);
753 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
755 module_param(nowayout, int, 0);
756 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
757 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
759 module_init(hpwdt_init);
760 module_exit(hpwdt_cleanup);