drivers/watchdog/iTCO_vendor_support.c

   1 /*
   2  *      intel TCO vendor specific watchdog driver support
   3  *
   4  *      (c) Copyright 2006-2009 Wim Van Sebroeck <wim@iguana.be>.
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  *
  11  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  12  *      provide warranty for any of this software. This material is
  13  *      provided "AS-IS" and at no charge.
  14  */
  15
  16 /*
  17  *      Includes, defines, variables, module parameters, ...
  18  */
  19
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 /* Module and version information */
  23 #define DRV_NAME        "iTCO_vendor_support"
  24 #define DRV_VERSION     "1.04"
  25
  26 /* Includes */
  27 #include <linux/module.h>               /* For module specific items */
  28 #include <linux/moduleparam.h>          /* For new moduleparam's */
  29 #include <linux/types.h>                /* For standard types (like size_t) */
  30 #include <linux/errno.h>                /* For the -ENODEV/... values */
  31 #include <linux/kernel.h>               /* For printk/panic/... */
  32 #include <linux/init.h>                 /* For __init/__exit/... */
  33 #include <linux/ioport.h>               /* For io-port access */
  34 #include <linux/io.h>                   /* For inb/outb/... */
  35
  36 #include "iTCO_vendor.h"
  37
  38 /* List of vendor support modes */
  39 /* SuperMicro Pentium 3 Era 370SSE+-OEM1/P3TSSE */
  40 #define SUPERMICRO_OLD_BOARD    1
  41 /* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems - no longer supported */
  42 #define SUPERMICRO_NEW_BOARD    2
  43 /* Broken BIOS */
  44 #define BROKEN_BIOS             911
  45
  46 static int vendorsupport;
  47 module_param(vendorsupport, int, 0);
  48 MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default="
  49                         "0 (none), 1=SuperMicro Pent3, 911=Broken SMI BIOS");
  50
  51 /*
  52  *      Vendor Specific Support
  53  */
  54
  55 /*
  56  *      Vendor Support: 1
  57  *      Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE
  58  *      iTCO chipset: ICH2
  59  *
  60  *      Code contributed by: R. Seretny <lkpatches@paypc.com>
  61  *      Documentation obtained by R. Seretny from SuperMicro Technical Support
  62  *
  63  *      To enable Watchdog function:
  64  *          BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes
  65  *          This setting enables SMI to clear the watchdog expired flag.
  66  *          If BIOS or CPU fail which may cause SMI hang, then system will
  67  *          reboot. When application starts to use watchdog function,
  68  *          application has to take over the control from SMI.
  69  *
  70  *          For P3TSSE, J36 jumper needs to be removed to enable the Watchdog
  71  *          function.
  72  *
  73  *          Note: The system will reboot when Expire Flag is set TWICE.
  74  *          So, if the watchdog timer is 20 seconds, then the maximum hang
  75  *          time is about 40 seconds, and the minimum hang time is about
  76  *          20.6 seconds.
  77  */
  78
  79 static void supermicro_old_pre_start(struct resource *smires)
  80 {
  81         unsigned long val32;
  82
  83         /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */
  84         val32 = inl(smires->start);
  85         val32 &= 0xffffdfff;    /* Turn off SMI clearing watchdog */
  86         outl(val32, smires->start);     /* Needed to activate watchdog */
  87 }
  88
  89 static void supermicro_old_pre_stop(struct resource *smires)
  90 {
  91         unsigned long val32;
  92
  93         /* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */
  94         val32 = inl(smires->start);
  95         val32 |= 0x00002000;    /* Turn on SMI clearing watchdog */
  96         outl(val32, smires->start);     /* Needed to deactivate watchdog */
  97 }
  98
  99 /*
 100  *      Vendor Support: 911
 101  *      Board: Some Intel ICHx based motherboards
 102  *      iTCO chipset: ICH7+
 103  *
 104  *      Some Intel motherboards have a broken BIOS implementation: i.e.
 105  *      the SMI handler clear's the TIMEOUT bit in the TC01_STS register
 106  *      and does not reload the time. Thus the TCO watchdog does not reboot
 107  *      the system.
 108  *
 109  *      These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after
 110  *      debugging: the SMI handler is quite simple - it tests value in
 111  *      TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set
 112  *      the handler goes into an infinite loop, apparently to allow the
 113  *      second timeout and reboot. Otherwise it simply clears TIMEOUT bit
 114  *      in TCO1_STS and that's it.
 115  *      So the logic seems to be reversed, because it is hard to see how
 116  *      TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set
 117  *      (other than a transitional effect).
 118  *
 119  *      The only fix found to get the motherboard(s) to reboot is to put
 120  *      the glb_smi_en bit to 0. This is a dirty hack that bypasses the
 121  *      broken code by disabling Global SMI.
 122  *
 123  *      WARNING: globally disabling SMI could possibly lead to dramatic
 124  *      problems, especially on laptops! I.e. various ACPI things where
 125  *      SMI is used for communication between OS and firmware.
 126  *
 127  *      Don't use this fix if you don't need to!!!
 128  */
 129
 130 static void broken_bios_start(struct resource *smires)
 131 {
 132         unsigned long val32;
 133
 134         val32 = inl(smires->start);
 135         /* Bit 13: TCO_EN     -> 0 = Disables TCO logic generating an SMI#
 136            Bit  0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */
 137         val32 &= 0xffffdffe;
 138         outl(val32, smires->start);
 139 }
 140
 141 static void broken_bios_stop(struct resource *smires)
 142 {
 143         unsigned long val32;
 144
 145         val32 = inl(smires->start);
 146         /* Bit 13: TCO_EN     -> 1 = Enables TCO logic generating an SMI#
 147            Bit  0: GBL_SMI_EN -> 1 = Turn global SMI on again. */
 148         val32 |= 0x00002001;
 149         outl(val32, smires->start);
 150 }
 151
 152 /*
 153  *      Generic Support Functions
 154  */
 155
 156 void iTCO_vendor_pre_start(struct resource *smires,
 157                            unsigned int heartbeat)
 158 {
 159         switch (vendorsupport) {
 160         case SUPERMICRO_OLD_BOARD:
 161                 supermicro_old_pre_start(smires);
 162                 break;
 163         case BROKEN_BIOS:
 164                 broken_bios_start(smires);
 165                 break;
 166         }
 167 }
 168 EXPORT_SYMBOL(iTCO_vendor_pre_start);
 169
 170 void iTCO_vendor_pre_stop(struct resource *smires)
 171 {
 172         switch (vendorsupport) {
 173         case SUPERMICRO_OLD_BOARD:
 174                 supermicro_old_pre_stop(smires);
 175                 break;
 176         case BROKEN_BIOS:
 177                 broken_bios_stop(smires);
 178                 break;
 179         }
 180 }
 181 EXPORT_SYMBOL(iTCO_vendor_pre_stop);
 182
 183 int iTCO_vendor_check_noreboot_on(void)
 184 {
 185         switch (vendorsupport) {
 186         case SUPERMICRO_OLD_BOARD:
 187                 return 0;
 188         default:
 189                 return 1;
 190         }
 191 }
 192 EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on);
 193
 194 static int __init iTCO_vendor_init_module(void)
 195 {
 196         if (vendorsupport == SUPERMICRO_NEW_BOARD) {
 197                 pr_warn("Option vendorsupport=%d is no longer supported, "
 198                         "please use the w83627hf_wdt driver instead\n",
 199                         SUPERMICRO_NEW_BOARD);
 200                 return -EINVAL;
 201         }
 202         pr_info("vendor-support=%d\n", vendorsupport);
 203         return 0;
 204 }
 205
 206 static void __exit iTCO_vendor_exit_module(void)
 207 {
 208         pr_info("Module Unloaded\n");
 209 }
 210
 211 module_init(iTCO_vendor_init_module);
 212 module_exit(iTCO_vendor_exit_module);
 213
 214 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, "
 215                 "R. Seretny <lkpatches@paypc.com>");
 216 MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
 217 MODULE_VERSION(DRV_VERSION);
 218 MODULE_LICENSE("GPL");
 219