1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * intel TCO vendor specific watchdog driver support 4 * 5 * (c) Copyright 2006-2009 Wim Van Sebroeck <wim@iguana.be>. 6 * 7 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor 8 * provide warranty for any of this software. This material is 9 * 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 ": " fmt 17 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 1 37 /* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems - no longer supported */ 38 #define SUPERMICRO_NEW_BOARD 2 39 /* Broken BIOS */ 40 #define BROKEN_BIOS 911 41 42 int iTCO_vendorsupport; 43 EXPORT_SYMBOL(iTCO_vendorsupport); 44 45 module_param_named(vendorsupport, iTCO_vendorsupport, int, 0); 46 MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default=" 47 "0 (none), 1=SuperMicro Pent3, 911=Broken SMI BIOS"); 48 49 /* 50 * Vendor Specific Support 51 */ 52 53 /* 54 * Vendor Support: 1 55 * Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE 56 * iTCO chipset: ICH2 57 * 58 * Code contributed by: R. Seretny <lkpatches@paypc.com> 59 * Documentation obtained by R. Seretny from SuperMicro Technical Support 60 * 61 * To enable Watchdog function: 62 * BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes 63 * This setting enables SMI to clear the watchdog expired flag. 64 * If BIOS or CPU fail which may cause SMI hang, then system will 65 * 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 Watchdog 69 * 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 hang 73 * time is about 40 seconds, and the minimum hang time is about 74 * 20.6 seconds. 75 */ 76 77 static 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 87 static 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: 911 99 * Board: Some Intel ICHx based motherboards 100 * 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 register 104 * and does not reload the time. Thus the TCO watchdog does not reboot 105 * the system. 106 * 107 * These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after 108 * debugging: the SMI handler is quite simple - it tests value in 109 * TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set 110 * the handler goes into an infinite loop, apparently to allow the 111 * second timeout and reboot. Otherwise it simply clears TIMEOUT bit 112 * in TCO1_STS and that's it. 113 * So the logic seems to be reversed, because it is hard to see how 114 * TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set 115 * (other than a transitional effect). 116 * 117 * The only fix found to get the motherboard(s) to reboot is to put 118 * the glb_smi_en bit to 0. This is a dirty hack that bypasses the 119 * broken code by disabling Global SMI. 120 * 121 * WARNING: globally disabling SMI could possibly lead to dramatic 122 * problems, especially on laptops! I.e. various ACPI things where 123 * SMI is used for communication between OS and firmware. 124 * 125 * Don't use this fix if you don't need to!!! 126 */ 127 128 static 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 } 138 139 static 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 Functions 152 */ 153 154 void 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 } 166 EXPORT_SYMBOL(iTCO_vendor_pre_start); 167 168 void 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 } 179 EXPORT_SYMBOL(iTCO_vendor_pre_stop); 180 181 int 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 } 190 EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on); 191 192 static 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 } 203 204 static void __exit iTCO_vendor_exit_module(void) 205 { 206 pr_info("Module Unloaded\n"); 207 } 208 209 module_init(iTCO_vendor_init_module); 210 module_exit(iTCO_vendor_exit_module); 211 212 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, " 213 "R. Seretny <lkpatches@paypc.com>"); 214 MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support"); 215 MODULE_VERSION(DRV_VERSION); 216 MODULE_LICENSE("GPL"); 217