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 static int vendorsupport; 43 module_param(vendorsupport, int, 0); 44 MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default=" 45 "0 (none), 1=SuperMicro Pent3, 911=Broken SMI BIOS"); 46 47 /* 48 * Vendor Specific Support 49 */ 50 51 /* 52 * Vendor Support: 1 53 * Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE 54 * iTCO chipset: ICH2 55 * 56 * Code contributed by: R. Seretny <lkpatches@paypc.com> 57 * Documentation obtained by R. Seretny from SuperMicro Technical Support 58 * 59 * To enable Watchdog function: 60 * BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes 61 * This setting enables SMI to clear the watchdog expired flag. 62 * If BIOS or CPU fail which may cause SMI hang, then system will 63 * reboot. When application starts to use watchdog function, 64 * application has to take over the control from SMI. 65 * 66 * For P3TSSE, J36 jumper needs to be removed to enable the Watchdog 67 * function. 68 * 69 * Note: The system will reboot when Expire Flag is set TWICE. 70 * So, if the watchdog timer is 20 seconds, then the maximum hang 71 * time is about 40 seconds, and the minimum hang time is about 72 * 20.6 seconds. 73 */ 74 75 static void supermicro_old_pre_start(struct resource *smires) 76 { 77 unsigned long val32; 78 79 /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */ 80 val32 = inl(smires->start); 81 val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */ 82 outl(val32, smires->start); /* Needed to activate watchdog */ 83 } 84 85 static void supermicro_old_pre_stop(struct resource *smires) 86 { 87 unsigned long val32; 88 89 /* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */ 90 val32 = inl(smires->start); 91 val32 |= 0x00002000; /* Turn on SMI clearing watchdog */ 92 outl(val32, smires->start); /* Needed to deactivate watchdog */ 93 } 94 95 /* 96 * Vendor Support: 911 97 * Board: Some Intel ICHx based motherboards 98 * iTCO chipset: ICH7+ 99 * 100 * Some Intel motherboards have a broken BIOS implementation: i.e. 101 * the SMI handler clear's the TIMEOUT bit in the TC01_STS register 102 * and does not reload the time. Thus the TCO watchdog does not reboot 103 * the system. 104 * 105 * These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after 106 * debugging: the SMI handler is quite simple - it tests value in 107 * TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set 108 * the handler goes into an infinite loop, apparently to allow the 109 * second timeout and reboot. Otherwise it simply clears TIMEOUT bit 110 * in TCO1_STS and that's it. 111 * So the logic seems to be reversed, because it is hard to see how 112 * TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set 113 * (other than a transitional effect). 114 * 115 * The only fix found to get the motherboard(s) to reboot is to put 116 * the glb_smi_en bit to 0. This is a dirty hack that bypasses the 117 * broken code by disabling Global SMI. 118 * 119 * WARNING: globally disabling SMI could possibly lead to dramatic 120 * problems, especially on laptops! I.e. various ACPI things where 121 * SMI is used for communication between OS and firmware. 122 * 123 * Don't use this fix if you don't need to!!! 124 */ 125 126 static void broken_bios_start(struct resource *smires) 127 { 128 unsigned long val32; 129 130 val32 = inl(smires->start); 131 /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# 132 Bit 0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */ 133 val32 &= 0xffffdffe; 134 outl(val32, smires->start); 135 } 136 137 static void broken_bios_stop(struct resource *smires) 138 { 139 unsigned long val32; 140 141 val32 = inl(smires->start); 142 /* Bit 13: TCO_EN -> 1 = Enables TCO logic generating an SMI# 143 Bit 0: GBL_SMI_EN -> 1 = Turn global SMI on again. */ 144 val32 |= 0x00002001; 145 outl(val32, smires->start); 146 } 147 148 /* 149 * Generic Support Functions 150 */ 151 152 void iTCO_vendor_pre_start(struct resource *smires, 153 unsigned int heartbeat) 154 { 155 switch (vendorsupport) { 156 case SUPERMICRO_OLD_BOARD: 157 supermicro_old_pre_start(smires); 158 break; 159 case BROKEN_BIOS: 160 broken_bios_start(smires); 161 break; 162 } 163 } 164 EXPORT_SYMBOL(iTCO_vendor_pre_start); 165 166 void iTCO_vendor_pre_stop(struct resource *smires) 167 { 168 switch (vendorsupport) { 169 case SUPERMICRO_OLD_BOARD: 170 supermicro_old_pre_stop(smires); 171 break; 172 case BROKEN_BIOS: 173 broken_bios_stop(smires); 174 break; 175 } 176 } 177 EXPORT_SYMBOL(iTCO_vendor_pre_stop); 178 179 int iTCO_vendor_check_noreboot_on(void) 180 { 181 switch (vendorsupport) { 182 case SUPERMICRO_OLD_BOARD: 183 return 0; 184 default: 185 return 1; 186 } 187 } 188 EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on); 189 190 static int __init iTCO_vendor_init_module(void) 191 { 192 if (vendorsupport == SUPERMICRO_NEW_BOARD) { 193 pr_warn("Option vendorsupport=%d is no longer supported, " 194 "please use the w83627hf_wdt driver instead\n", 195 SUPERMICRO_NEW_BOARD); 196 return -EINVAL; 197 } 198 pr_info("vendor-support=%d\n", vendorsupport); 199 return 0; 200 } 201 202 static void __exit iTCO_vendor_exit_module(void) 203 { 204 pr_info("Module Unloaded\n"); 205 } 206 207 module_init(iTCO_vendor_init_module); 208 module_exit(iTCO_vendor_exit_module); 209 210 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, " 211 "R. Seretny <lkpatches@paypc.com>"); 212 MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support"); 213 MODULE_VERSION(DRV_VERSION); 214 MODULE_LICENSE("GPL"); 215