// SPDX-License-Identifier: GPL-2.0+ /* * intel TCO vendor specific watchdog driver support * * (c) Copyright 2006-2009 Wim Van Sebroeck . * * 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 /* For module specific items */ #include /* For new moduleparam's */ #include /* For standard types (like size_t) */ #include /* For the -ENODEV/... values */ #include /* For printk/panic/... */ #include /* For __init/__exit/... */ #include /* For io-port access */ #include /* 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 static int vendorsupport; module_param(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 * 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 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 (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 (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 (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 (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", 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 , " "R. Seretny "); MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support"); MODULE_VERSION(DRV_VERSION); MODULE_LICENSE("GPL");