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(port: smires->start); |
83 | val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */ |
84 | outl(value: val32, port: 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(port: smires->start); |
93 | val32 |= 0x00002000; /* Turn on SMI clearing watchdog */ |
94 | outl(value: val32, port: 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(port: 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(value: val32, port: smires->start); |
137 | } |
138 | |
139 | static void broken_bios_stop(struct resource *smires) |
140 | { |
141 | unsigned long val32; |
142 | |
143 | val32 = inl(port: 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(value: val32, port: 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 | |