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1// SPDX-License-Identifier: GPL-2.0+2/*3 * intel TCO vendor specific watchdog driver support4 *5 * (c) Copyright 2006-2009 Wim Van Sebroeck <wim@iguana.be>.6 *7 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor8 * provide warranty for any of this software. This material is9 * provided "AS-IS" and at no charge.10 */11 12/*13 * Includes, defines, variables, module parameters, ...14 */15 16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt17 18/* Module and version information */19#define DRV_NAME "iTCO_vendor_support"20#define DRV_VERSION "1.04"21 22/* Includes */23#include <linux/module.h> /* For module specific items */24#include <linux/moduleparam.h> /* For new moduleparam's */25#include <linux/types.h> /* For standard types (like size_t) */26#include <linux/errno.h> /* For the -ENODEV/... values */27#include <linux/kernel.h> /* For printk/panic/... */28#include <linux/init.h> /* For __init/__exit/... */29#include <linux/ioport.h> /* For io-port access */30#include <linux/io.h> /* For inb/outb/... */31 32#include "iTCO_vendor.h"33 34/* List of vendor support modes */35/* SuperMicro Pentium 3 Era 370SSE+-OEM1/P3TSSE */36#define SUPERMICRO_OLD_BOARD 137/* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems - no longer supported */38#define SUPERMICRO_NEW_BOARD 239/* Broken BIOS */40#define BROKEN_BIOS 91141 42int iTCO_vendorsupport;43EXPORT_SYMBOL(iTCO_vendorsupport);44 45module_param_named(vendorsupport, iTCO_vendorsupport, int, 0);46MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default="47 "0 (none), 1=SuperMicro Pent3, 911=Broken SMI BIOS");48 49/*50 * Vendor Specific Support51 */52 53/*54 * Vendor Support: 155 * Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE56 * iTCO chipset: ICH257 *58 * Code contributed by: R. Seretny <lkpatches@paypc.com>59 * Documentation obtained by R. Seretny from SuperMicro Technical Support60 *61 * To enable Watchdog function:62 * BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes63 * This setting enables SMI to clear the watchdog expired flag.64 * If BIOS or CPU fail which may cause SMI hang, then system will65 * reboot. When application starts to use watchdog function,66 * application has to take over the control from SMI.67 *68 * For P3TSSE, J36 jumper needs to be removed to enable the Watchdog69 * function.70 *71 * Note: The system will reboot when Expire Flag is set TWICE.72 * So, if the watchdog timer is 20 seconds, then the maximum hang73 * time is about 40 seconds, and the minimum hang time is about74 * 20.6 seconds.75 */76 77static void supermicro_old_pre_start(struct resource *smires)78{79 unsigned long val32;80 81 /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */82 val32 = inl(smires->start);83 val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */84 outl(val32, smires->start); /* Needed to activate watchdog */85}86 87static void supermicro_old_pre_stop(struct resource *smires)88{89 unsigned long val32;90 91 /* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */92 val32 = inl(smires->start);93 val32 |= 0x00002000; /* Turn on SMI clearing watchdog */94 outl(val32, smires->start); /* Needed to deactivate watchdog */95}96 97/*98 * Vendor Support: 91199 * Board: Some Intel ICHx based motherboards100 * iTCO chipset: ICH7+101 *102 * Some Intel motherboards have a broken BIOS implementation: i.e.103 * the SMI handler clear's the TIMEOUT bit in the TC01_STS register104 * and does not reload the time. Thus the TCO watchdog does not reboot105 * the system.106 *107 * These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after108 * debugging: the SMI handler is quite simple - it tests value in109 * TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set110 * the handler goes into an infinite loop, apparently to allow the111 * second timeout and reboot. Otherwise it simply clears TIMEOUT bit112 * in TCO1_STS and that's it.113 * So the logic seems to be reversed, because it is hard to see how114 * TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set115 * (other than a transitional effect).116 *117 * The only fix found to get the motherboard(s) to reboot is to put118 * the glb_smi_en bit to 0. This is a dirty hack that bypasses the119 * broken code by disabling Global SMI.120 *121 * WARNING: globally disabling SMI could possibly lead to dramatic122 * problems, especially on laptops! I.e. various ACPI things where123 * SMI is used for communication between OS and firmware.124 *125 * Don't use this fix if you don't need to!!!126 */127 128static void broken_bios_start(struct resource *smires)129{130 unsigned long val32;131 132 val32 = inl(smires->start);133 /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI#134 Bit 0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */135 val32 &= 0xffffdffe;136 outl(val32, smires->start);137}138 139static void broken_bios_stop(struct resource *smires)140{141 unsigned long val32;142 143 val32 = inl(smires->start);144 /* Bit 13: TCO_EN -> 1 = Enables TCO logic generating an SMI#145 Bit 0: GBL_SMI_EN -> 1 = Turn global SMI on again. */146 val32 |= 0x00002001;147 outl(val32, smires->start);148}149 150/*151 * Generic Support Functions152 */153 154void iTCO_vendor_pre_start(struct resource *smires,155 unsigned int heartbeat)156{157 switch (iTCO_vendorsupport) {158 case SUPERMICRO_OLD_BOARD:159 supermicro_old_pre_start(smires);160 break;161 case BROKEN_BIOS:162 broken_bios_start(smires);163 break;164 }165}166EXPORT_SYMBOL(iTCO_vendor_pre_start);167 168void iTCO_vendor_pre_stop(struct resource *smires)169{170 switch (iTCO_vendorsupport) {171 case SUPERMICRO_OLD_BOARD:172 supermicro_old_pre_stop(smires);173 break;174 case BROKEN_BIOS:175 broken_bios_stop(smires);176 break;177 }178}179EXPORT_SYMBOL(iTCO_vendor_pre_stop);180 181int iTCO_vendor_check_noreboot_on(void)182{183 switch (iTCO_vendorsupport) {184 case SUPERMICRO_OLD_BOARD:185 return 0;186 default:187 return 1;188 }189}190EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on);191 192static int __init iTCO_vendor_init_module(void)193{194 if (iTCO_vendorsupport == SUPERMICRO_NEW_BOARD) {195 pr_warn("Option vendorsupport=%d is no longer supported, "196 "please use the w83627hf_wdt driver instead\n",197 SUPERMICRO_NEW_BOARD);198 return -EINVAL;199 }200 pr_info("vendor-support=%d\n", iTCO_vendorsupport);201 return 0;202}203 204static void __exit iTCO_vendor_exit_module(void)205{206 pr_info("Module Unloaded\n");207}208 209module_init(iTCO_vendor_init_module);210module_exit(iTCO_vendor_exit_module);211 212MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, "213 "R. Seretny <lkpatches@paypc.com>");214MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");215MODULE_VERSION(DRV_VERSION);216MODULE_LICENSE("GPL");217