diff options
Diffstat (limited to 'drivers/watchdog/iTCO_vendor_support.c')
| -rw-r--r-- | drivers/watchdog/iTCO_vendor_support.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/watchdog/iTCO_vendor_support.c b/drivers/watchdog/iTCO_vendor_support.c new file mode 100644 index 000000000..cf0eaa04b --- /dev/null +++ b/drivers/watchdog/iTCO_vendor_support.c @@ -0,0 +1,216 @@ +// 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"); |