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 */
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 <lkpatches@paypc.com>
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 <lkpatches@paypc.com>
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 */
168 	outb(SM_WATCHPAGE, SM_REGINDEX);
169 	outb(SM_WATCHPAGE, SM_REGINDEX);
170 	/* Switch to watchdog control page */
171 	outb(SM_CTLPAGESW, SM_REGINDEX);
172 	outb(SM_CTLPAGE, SM_DATAIO);
173 }
174 
175 static void supermicro_new_lock_watchdog(void)
176 {
177 	outb(SM_ENDWATCH, SM_REGINDEX);
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*/
187 	outb(SM_COUNTMODE, SM_REGINDEX);
188 	val = inb(SM_DATAIO);
189 	val &= 0xF7;
190 	outb(val, SM_DATAIO);
191 
192 	/* Write heartbeat interval to WDOG */
193 	outb(SM_WATCHTIMER, SM_REGINDEX);
194 	outb((heartbeat & 255), SM_DATAIO);
195 
196 	/* Make sure keyboard/mouse interrupts don't interfere */
197 	outb(SM_RESETCONTROL, SM_REGINDEX);
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 */
203 	outb(SM_WATCHENABLE, SM_REGINDEX);
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 */
218 	outb(SM_WATCHENABLE, SM_REGINDEX);
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 */
231 	outb(SM_WATCHTIMER, SM_REGINDEX);
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 <avg@icyb.net.ua> 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) {
298 	case SUPERMICRO_OLD_BOARD:
299 		supermicro_old_pre_start(smires);
300 		break;
301 	case SUPERMICRO_NEW_BOARD:
302 		supermicro_new_pre_start(heartbeat);
303 		break;
304 	case BROKEN_BIOS:
305 		broken_bios_start(smires);
306 		break;
307 	}
308 }
309 EXPORT_SYMBOL(iTCO_vendor_pre_start);
310 
311 void iTCO_vendor_pre_stop(struct resource *smires)
312 {
313 	switch (vendorsupport) {
314 	case SUPERMICRO_OLD_BOARD:
315 		supermicro_old_pre_stop(smires);
316 		break;
317 	case SUPERMICRO_NEW_BOARD:
318 		supermicro_new_pre_stop();
319 		break;
320 	case BROKEN_BIOS:
321 		broken_bios_stop(smires);
322 		break;
323 	}
324 }
325 EXPORT_SYMBOL(iTCO_vendor_pre_stop);
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 }
332 EXPORT_SYMBOL(iTCO_vendor_pre_keepalive);
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 }
339 EXPORT_SYMBOL(iTCO_vendor_pre_set_heartbeat);
340 
341 int iTCO_vendor_check_noreboot_on(void)
342 {
343 	switch (vendorsupport) {
344 	case SUPERMICRO_OLD_BOARD:
345 		return 0;
346 	default:
347 		return 1;
348 	}
349 }
350 EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on);
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 <wim@iguana.be>, "
367 		"R. Seretny <lkpatches@paypc.com>");
368 MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
369 MODULE_VERSION(DRV_VERSION);
370 MODULE_LICENSE("GPL");
371 
372