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iTCO_vendor_support.c
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1 /*
2  * intel TCO vendor specific watchdog driver support
3  *
4  * (c) Copyright 2006-2009 Wim Van Sebroeck <[email protected]>.
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 */
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, 2=SuperMicro Pent4+, "
50  "911=Broken SMI BIOS");
51 
52 /*
53  * Vendor Specific Support
54  */
55 
56 /*
57  * Vendor Support: 1
58  * Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE
59  * iTCO chipset: ICH2
60  *
61  * Code contributed by: R. Seretny <[email protected]>
62  * Documentation obtained by R. Seretny from SuperMicro Technical Support
63  *
64  * To enable Watchdog function:
65  * BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes
66  * This setting enables SMI to clear the watchdog expired flag.
67  * If BIOS or CPU fail which may cause SMI hang, then system will
68  * reboot. When application starts to use watchdog function,
69  * application has to take over the control from SMI.
70  *
71  * For P3TSSE, J36 jumper needs to be removed to enable the Watchdog
72  * function.
73  *
74  * Note: The system will reboot when Expire Flag is set TWICE.
75  * So, if the watchdog timer is 20 seconds, then the maximum hang
76  * time is about 40 seconds, and the minimum hang time is about
77  * 20.6 seconds.
78  */
79 
80 static void supermicro_old_pre_start(struct resource *smires)
81 {
82  unsigned long val32;
83 
84  /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */
85  val32 = inl(smires->start);
86  val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */
87  outl(val32, smires->start); /* Needed to activate watchdog */
88 }
89 
90 static void supermicro_old_pre_stop(struct resource *smires)
91 {
92  unsigned long val32;
93 
94  /* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */
95  val32 = inl(smires->start);
96  val32 |= 0x00002000; /* Turn on SMI clearing watchdog */
97  outl(val32, smires->start); /* Needed to deactivate watchdog */
98 }
99 
100 /*
101  * Vendor Support: 2
102  * Board: Super Micro Computer Inc. P4SBx, P4DPx
103  * iTCO chipset: ICH4
104  *
105  * Code contributed by: R. Seretny <[email protected]>
106  * Documentation obtained by R. Seretny from SuperMicro Technical Support
107  *
108  * To enable Watchdog function:
109  * 1. BIOS
110  * For P4SBx:
111  * BIOS setup -> Advanced -> Integrated Peripherals -> Watch Dog Feature
112  * For P4DPx:
113  * BIOS setup -> Advanced -> I/O Device Configuration -> Watch Dog
114  * This setting enables or disables Watchdog function. When enabled, the
115  * default watchdog timer is set to be 5 minutes (about 4m35s). It is
116  * enough to load and run the OS. The application (service or driver) has
117  * to take over the control once OS is running up and before watchdog
118  * expires.
119  *
120  * 2. JUMPER
121  * For P4SBx: JP39
122  * For P4DPx: JP37
123  * This jumper is used for safety. Closed is enabled. This jumper
124  * prevents user enables watchdog in BIOS by accident.
125  *
126  * To enable Watch Dog function, both BIOS and JUMPER must be enabled.
127  *
128  * The documentation lists motherboards P4SBx and P4DPx series as of
129  * 20-March-2002. However, this code works flawlessly with much newer
130  * motherboards, such as my X6DHR-8G2 (SuperServer 6014H-82).
131  *
132  * The original iTCO driver as written does not actually reset the
133  * watchdog timer on these machines, as a result they reboot after five
134  * minutes.
135  *
136  * NOTE: You may leave the Watchdog function disabled in the SuperMicro
137  * BIOS to avoid a "boot-race"... This driver will enable watchdog
138  * functionality even if it's disabled in the BIOS once the /dev/watchdog
139  * file is opened.
140  */
141 
142 /* I/O Port's */
143 #define SM_REGINDEX 0x2e /* SuperMicro ICH4+ Register Index */
144 #define SM_DATAIO 0x2f /* SuperMicro ICH4+ Register Data I/O */
145 
146 /* Control Register's */
147 #define SM_CTLPAGESW 0x07 /* SuperMicro ICH4+ Control Page Switch */
148 #define SM_CTLPAGE 0x08 /* SuperMicro ICH4+ Control Page Num */
149 
150 #define SM_WATCHENABLE 0x30 /* Watchdog enable: Bit 0: 0=off, 1=on */
151 
152 #define SM_WATCHPAGE 0x87 /* Watchdog unlock control page */
153 
154 #define SM_ENDWATCH 0xAA /* Watchdog lock control page */
155 
156 #define SM_COUNTMODE 0xf5 /* Watchdog count mode select */
157  /* (Bit 3: 0 = seconds, 1 = minutes */
158 
159 #define SM_WATCHTIMER 0xf6 /* 8-bits, Watchdog timer counter (RW) */
160 
161 #define SM_RESETCONTROL 0xf7 /* Watchdog reset control */
162  /* Bit 6: timer is reset by kbd interrupt */
163  /* Bit 7: timer is reset by mouse interrupt */
164 
165 static void supermicro_new_unlock_watchdog(void)
166 {
167  /* Write 0x87 to port 0x2e twice */
170  /* Switch to watchdog control page */
173 }
174 
175 static void supermicro_new_lock_watchdog(void)
176 {
178 }
179 
180 static void supermicro_new_pre_start(unsigned int heartbeat)
181 {
182  unsigned int val;
183 
184  supermicro_new_unlock_watchdog();
185 
186  /* Watchdog timer setting needs to be in seconds*/
188  val = inb(SM_DATAIO);
189  val &= 0xF7;
190  outb(val, SM_DATAIO);
191 
192  /* Write heartbeat interval to WDOG */
194  outb((heartbeat & 255), SM_DATAIO);
195 
196  /* Make sure keyboard/mouse interrupts don't interfere */
198  val = inb(SM_DATAIO);
199  val &= 0x3f;
200  outb(val, SM_DATAIO);
201 
202  /* enable watchdog by setting bit 0 of Watchdog Enable to 1 */
204  val = inb(SM_DATAIO);
205  val |= 0x01;
206  outb(val, SM_DATAIO);
207 
208  supermicro_new_lock_watchdog();
209 }
210 
211 static void supermicro_new_pre_stop(void)
212 {
213  unsigned int val;
214 
215  supermicro_new_unlock_watchdog();
216 
217  /* disable watchdog by setting bit 0 of Watchdog Enable to 0 */
219  val = inb(SM_DATAIO);
220  val &= 0xFE;
221  outb(val, SM_DATAIO);
222 
223  supermicro_new_lock_watchdog();
224 }
225 
226 static void supermicro_new_pre_set_heartbeat(unsigned int heartbeat)
227 {
228  supermicro_new_unlock_watchdog();
229 
230  /* reset watchdog timeout to heartveat value */
232  outb((heartbeat & 255), SM_DATAIO);
233 
234  supermicro_new_lock_watchdog();
235 }
236 
237 /*
238  * Vendor Support: 911
239  * Board: Some Intel ICHx based motherboards
240  * iTCO chipset: ICH7+
241  *
242  * Some Intel motherboards have a broken BIOS implementation: i.e.
243  * the SMI handler clear's the TIMEOUT bit in the TC01_STS register
244  * and does not reload the time. Thus the TCO watchdog does not reboot
245  * the system.
246  *
247  * These are the conclusions of Andriy Gapon <[email protected]> after
248  * debugging: the SMI handler is quite simple - it tests value in
249  * TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set
250  * the handler goes into an infinite loop, apparently to allow the
251  * second timeout and reboot. Otherwise it simply clears TIMEOUT bit
252  * in TCO1_STS and that's it.
253  * So the logic seems to be reversed, because it is hard to see how
254  * TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set
255  * (other than a transitional effect).
256  *
257  * The only fix found to get the motherboard(s) to reboot is to put
258  * the glb_smi_en bit to 0. This is a dirty hack that bypasses the
259  * broken code by disabling Global SMI.
260  *
261  * WARNING: globally disabling SMI could possibly lead to dramatic
262  * problems, especially on laptops! I.e. various ACPI things where
263  * SMI is used for communication between OS and firmware.
264  *
265  * Don't use this fix if you don't need to!!!
266  */
267 
268 static void broken_bios_start(struct resource *smires)
269 {
270  unsigned long val32;
271 
272  val32 = inl(smires->start);
273  /* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI#
274  Bit 0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */
275  val32 &= 0xffffdffe;
276  outl(val32, smires->start);
277 }
278 
279 static void broken_bios_stop(struct resource *smires)
280 {
281  unsigned long val32;
282 
283  val32 = inl(smires->start);
284  /* Bit 13: TCO_EN -> 1 = Enables TCO logic generating an SMI#
285  Bit 0: GBL_SMI_EN -> 1 = Turn global SMI on again. */
286  val32 |= 0x00002001;
287  outl(val32, smires->start);
288 }
289 
290 /*
291  * Generic Support Functions
292  */
293 
294 void iTCO_vendor_pre_start(struct resource *smires,
295  unsigned int heartbeat)
296 {
297  switch (vendorsupport) {
299  supermicro_old_pre_start(smires);
300  break;
302  supermicro_new_pre_start(heartbeat);
303  break;
304  case BROKEN_BIOS:
305  broken_bios_start(smires);
306  break;
307  }
308 }
310 
311 void iTCO_vendor_pre_stop(struct resource *smires)
312 {
313  switch (vendorsupport) {
315  supermicro_old_pre_stop(smires);
316  break;
318  supermicro_new_pre_stop();
319  break;
320  case BROKEN_BIOS:
321  broken_bios_stop(smires);
322  break;
323  }
324 }
326 
327 void iTCO_vendor_pre_keepalive(struct resource *smires, unsigned int heartbeat)
328 {
329  if (vendorsupport == SUPERMICRO_NEW_BOARD)
330  supermicro_new_pre_set_heartbeat(heartbeat);
331 }
333 
334 void iTCO_vendor_pre_set_heartbeat(unsigned int heartbeat)
335 {
336  if (vendorsupport == SUPERMICRO_NEW_BOARD)
337  supermicro_new_pre_set_heartbeat(heartbeat);
338 }
340 
342 {
343  switch (vendorsupport) {
345  return 0;
346  default:
347  return 1;
348  }
349 }
351 
352 static int __init iTCO_vendor_init_module(void)
353 {
354  pr_info("vendor-support=%d\n", vendorsupport);
355  return 0;
356 }
357 
358 static void __exit iTCO_vendor_exit_module(void)
359 {
360  pr_info("Module Unloaded\n");
361 }
362 
363 module_init(iTCO_vendor_init_module);
364 module_exit(iTCO_vendor_exit_module);
365 
366 MODULE_AUTHOR("Wim Van Sebroeck <[email protected]>, "
367  "R. Seretny <[email protected]>");
368 MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
370 MODULE_LICENSE("GPL");
371