// SPDX-License-Identifier: GPL-2.0+
/*
* intel TCO vendor specific watchdog driver support
*
* (c) Copyright 2006-2009 Wim Van Sebroeck <wim@iguana.be>.
*
* Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
* provide warranty for any of this software. This material is
* provided "AS-IS" and at no charge.
*/
/*
* Includes, defines, variables, module parameters, ...
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
/* Module and version information */
#define DRV_NAME "iTCO_vendor_support"
#define DRV_VERSION "1.04"
/* Includes */
#include <linux/module.h> /* For module specific items */
#include <linux/moduleparam.h> /* For new moduleparam's */
#include <linux/types.h> /* For standard types (like size_t) */
#include <linux/errno.h> /* For the -ENODEV/... values */
#include <linux/kernel.h> /* For printk/panic/... */
#include <linux/init.h> /* For __init/__exit/... */
#include <linux/ioport.h> /* For io-port access */
#include <linux/io.h> /* For inb/outb/... */
#include "iTCO_vendor.h"
/* List of vendor support modes */
/* SuperMicro Pentium 3 Era 370SSE+-OEM1/P3TSSE */
#define SUPERMICRO_OLD_BOARD 1
/* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems - no longer supported */
#define SUPERMICRO_NEW_BOARD 2
/* Broken BIOS */
#define BROKEN_BIOS 911
int iTCO_vendorsupport;
EXPORT_SYMBOL(iTCO_vendorsupport);
module_param_named(vendorsupport, iTCO_vendorsupport, int, 0);
MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default="
"0 (none), 1=SuperMicro Pent3, 911=Broken SMI BIOS");
/*
* Vendor Specific Support
*/
/*
* Vendor Support: 1
* Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE
* iTCO chipset: ICH2
*
* Code contributed by: R. Seretny <lkpatches@paypc.com>
* Documentation obtained by R. Seretny from SuperMicro Technical Support
*
* To enable Watchdog function:
* BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes
* This setting enables SMI to clear the watchdog expired flag.
* If BIOS or CPU fail which may cause SMI hang, then system will
* reboot. When application starts to use watchdog function,
* application has to take over the control from SMI.
*
* For P3TSSE, J36 jumper needs to be removed to enable the Watchdog
* function.
*
* Note: The system will reboot when Expire Flag is set TWICE.
* So, if the watchdog timer is 20 seconds, then the maximum hang
* time is about 40 seconds, and the minimum hang time is about
* 20.6 seconds.
*/
static void supermicro_old_pre_start(struct resource *smires)
{
unsigned long val32;
/* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */
val32 = inl(smires->start);
val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */
outl(val32, smires->start); /* Needed to activate watchdog */
}
static void supermicro_old_pre_stop(struct resource *smires)
{
unsigned long val32;
/* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */
val32 = inl(smires->start);
val32 |= 0x00002000; /* Turn on SMI clearing watchdog */
outl(val32, smires->start); /* Needed to deactivate watchdog */
}
/*
* Vendor Support: 911
* Board: Some Intel ICHx based motherboards
* iTCO chipset: ICH7+
*
* Some Intel motherboards have a broken BIOS implementation: i.e.
* the SMI handler clear's the TIMEOUT bit in the TC01_STS register
* and does not reload the time. Thus the TCO watchdog does not reboot
* the system.
*
* These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after
* debugging: the SMI handler is quite simple - it tests value in
* TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set
* the handler goes into an infinite loop, apparently to allow the
* second timeout and reboot. Otherwise it simply clears TIMEOUT bit
* in TCO1_STS and that's it.
* So the logic seems to be reversed, because it is hard to see how
* TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set
* (other than a transitional effect).
*
* The only fix found to get the motherboard(s) to reboot is to put
* the glb_smi_en bit to 0. This is a dirty hack that bypasses the
* broken code by disabling Global SMI.
*
* WARNING: globally disabling SMI could possibly lead to dramatic
* problems, especially on laptops! I.e. various ACPI things where
* SMI is used for communication between OS and firmware.
*
* Don't use this fix if you don't need to!!!
*/
static void broken_bios_start(struct resource *smires)
{
unsigned long val32;
val32 = inl(smires->start);
/* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI#
Bit 0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */
val32 &= 0xffffdffe;
outl(val32, smires->start);
}
static void broken_bios_stop(struct resource *smires)
{
unsigned long val32;
val32 = inl(smires->start);
/* Bit 13: TCO_EN -> 1 = Enables TCO logic generating an SMI#
Bit 0: GBL_SMI_EN -> 1 = Turn global SMI on again. */
val32 |= 0x00002001;
outl(val32, smires->start);
}
/*
* Generic Support Functions
*/
void iTCO_vendor_pre_start(struct resource *smires,
unsigned int heartbeat)
{
switch (iTCO_vendorsupport) {
case SUPERMICRO_OLD_BOARD:
supermicro_old_pre_start(smires);
break;
case BROKEN_BIOS:
broken_bios_start(smires);
break;
}
}
EXPORT_SYMBOL(iTCO_vendor_pre_start);
void iTCO_vendor_pre_stop(struct resource *smires)
{
switch (iTCO_vendorsupport) {
case SUPERMICRO_OLD_BOARD:
supermicro_old_pre_stop(smires);
break;
case BROKEN_BIOS:
broken_bios_stop(smires);
break;
}
}
EXPORT_SYMBOL(iTCO_vendor_pre_stop);
int iTCO_vendor_check_noreboot_on(void)
{
switch (iTCO_vendorsupport) {
case SUPERMICRO_OLD_BOARD:
return 0;
default:
return 1;
}
}
EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on);
static int __init iTCO_vendor_init_module(void)
{
if (iTCO_vendorsupport == SUPERMICRO_NEW_BOARD) {
pr_warn("Option vendorsupport=%d is no longer supported, "
"please use the w83627hf_wdt driver instead\n",
SUPERMICRO_NEW_BOARD);
return -EINVAL;
}
pr_info("vendor-support=%d\n", iTCO_vendorsupport);
return 0;
}
static void __exit iTCO_vendor_exit_module(void)
{
pr_info("Module Unloaded\n");
}
module_init(iTCO_vendor_init_module);
module_exit(iTCO_vendor_exit_module);
MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, "
"R. Seretny <lkpatches@paypc.com>");
MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE("GPL");
