[mirror_ubuntu-hirsute-kernel.git] / drivers / watchdog / iTCO_vendor_support.c

// SPDX-License-Identifier: GPL-2.0+
/*
 *	intel TCO vendor specific watchdog driver support
 *
 *	(c) Copyright 2006-2009 Wim Van Sebroeck <wim@iguana.be>.
 *
 *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
 *	provide warranty for any of this software. This material is
 *	provided "AS-IS" and at no charge.
 */

/*
 *	Includes, defines, variables, module parameters, ...
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

/* Module and version information */
#define DRV_NAME	"iTCO_vendor_support"
#define DRV_VERSION	"1.04"

/* Includes */
#include <linux/module.h>		/* For module specific items */
#include <linux/moduleparam.h>		/* For new moduleparam's */
#include <linux/types.h>		/* For standard types (like size_t) */
#include <linux/errno.h>		/* For the -ENODEV/... values */
#include <linux/kernel.h>		/* For printk/panic/... */
#include <linux/init.h>			/* For __init/__exit/... */
#include <linux/ioport.h>		/* For io-port access */
#include <linux/io.h>			/* For inb/outb/... */

#include "iTCO_vendor.h"

/* List of vendor support modes */
/* SuperMicro Pentium 3 Era 370SSE+-OEM1/P3TSSE */
#define SUPERMICRO_OLD_BOARD	1
/* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems - no longer supported */
#define SUPERMICRO_NEW_BOARD	2
/* Broken BIOS */
#define BROKEN_BIOS		911

static int vendorsupport;
module_param(vendorsupport, int, 0);
MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default="
			"0 (none), 1=SuperMicro Pent3, 911=Broken SMI BIOS");

/*
 *	Vendor Specific Support
 */

/*
 *	Vendor Support: 1
 *	Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE
 *	iTCO chipset: ICH2
 *
 *	Code contributed by: R. Seretny <lkpatches@paypc.com>
 *	Documentation obtained by R. Seretny from SuperMicro Technical Support
 *
 *	To enable Watchdog function:
 *	    BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes
 *	    This setting enables SMI to clear the watchdog expired flag.
 *	    If BIOS or CPU fail which may cause SMI hang, then system will
 *	    reboot. When application starts to use watchdog function,
 *	    application has to take over the control from SMI.
 *
 *	    For P3TSSE, J36 jumper needs to be removed to enable the Watchdog
 *	    function.
 *
 *	    Note: The system will reboot when Expire Flag is set TWICE.
 *	    So, if the watchdog timer is 20 seconds, then the maximum hang
 *	    time is about 40 seconds, and the minimum hang time is about
 *	    20.6 seconds.
 */

static void supermicro_old_pre_start(struct resource *smires)
{
	unsigned long val32;

	/* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */
	val32 = inl(smires->start);
	val32 &= 0xffffdfff;	/* Turn off SMI clearing watchdog */
	outl(val32, smires->start);	/* Needed to activate watchdog */
}

static void supermicro_old_pre_stop(struct resource *smires)
{
	unsigned long val32;

	/* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */
	val32 = inl(smires->start);
	val32 |= 0x00002000;	/* Turn on SMI clearing watchdog */
	outl(val32, smires->start);	/* Needed to deactivate watchdog */
}

/*
 *	Vendor Support: 911
 *	Board: Some Intel ICHx based motherboards
 *	iTCO chipset: ICH7+
 *
 *	Some Intel motherboards have a broken BIOS implementation: i.e.
 *	the SMI handler clear's the TIMEOUT bit in the TC01_STS register
 *	and does not reload the time. Thus the TCO watchdog does not reboot
 *	the system.
 *
 *	These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after
 *	debugging: the SMI handler is quite simple - it tests value in
 *	TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set
 *	the handler goes into an infinite loop, apparently to allow the
 *	second timeout and reboot. Otherwise it simply clears TIMEOUT bit
 *	in TCO1_STS and that's it.
 *	So the logic seems to be reversed, because it is hard to see how
 *	TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set
 *	(other than a transitional effect).
 *
 *	The only fix found to get the motherboard(s) to reboot is to put
 *	the glb_smi_en bit to 0. This is a dirty hack that bypasses the
 *	broken code by disabling Global SMI.
 *
 *	WARNING: globally disabling SMI could possibly lead to dramatic
 *	problems, especially on laptops! I.e. various ACPI things where
 *	SMI is used for communication between OS and firmware.
 *
 *	Don't use this fix if you don't need to!!!
 */

static void broken_bios_start(struct resource *smires)
{
	unsigned long val32;

	val32 = inl(smires->start);
	/* Bit 13: TCO_EN     -> 0 = Disables TCO logic generating an SMI#
	   Bit  0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */
	val32 &= 0xffffdffe;
	outl(val32, smires->start);
}

static void broken_bios_stop(struct resource *smires)
{
	unsigned long val32;

	val32 = inl(smires->start);
	/* Bit 13: TCO_EN     -> 1 = Enables TCO logic generating an SMI#
	   Bit  0: GBL_SMI_EN -> 1 = Turn global SMI on again. */
	val32 |= 0x00002001;
	outl(val32, smires->start);
}

/*
 *	Generic Support Functions
 */

void iTCO_vendor_pre_start(struct resource *smires,
			   unsigned int heartbeat)
{
	switch (vendorsupport) {
	case SUPERMICRO_OLD_BOARD:
		supermicro_old_pre_start(smires);
		break;
	case BROKEN_BIOS:
		broken_bios_start(smires);
		break;
	}
}
EXPORT_SYMBOL(iTCO_vendor_pre_start);

void iTCO_vendor_pre_stop(struct resource *smires)
{
	switch (vendorsupport) {
	case SUPERMICRO_OLD_BOARD:
		supermicro_old_pre_stop(smires);
		break;
	case BROKEN_BIOS:
		broken_bios_stop(smires);
		break;
	}
}
EXPORT_SYMBOL(iTCO_vendor_pre_stop);

int iTCO_vendor_check_noreboot_on(void)
{
	switch (vendorsupport) {
	case SUPERMICRO_OLD_BOARD:
		return 0;
	default:
		return 1;
	}
}
EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on);

static int __init iTCO_vendor_init_module(void)
{
	if (vendorsupport == SUPERMICRO_NEW_BOARD) {
		pr_warn("Option vendorsupport=%d is no longer supported, "
			"please use the w83627hf_wdt driver instead\n",
			SUPERMICRO_NEW_BOARD);
		return -EINVAL;
	}
	pr_info("vendor-support=%d\n", vendorsupport);
	return 0;
}

static void __exit iTCO_vendor_exit_module(void)
{
	pr_info("Module Unloaded\n");
}

module_init(iTCO_vendor_init_module);
module_exit(iTCO_vendor_exit_module);

MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, "
		"R. Seretny <lkpatches@paypc.com>");
MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE("GPL");
Commit	Line	Data
d0173278	1	// SPDX-License-Identifier: GPL-2.0+
e033351d WVS	2	/*
	3	* intel TCO vendor specific watchdog driver support
	4	*
12d60e28	5	* (c) Copyright 2006-2009 Wim Van Sebroeck <wim@iguana.be>.
e033351d	6	*
e033351d WVS	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
27c766aa JP	16	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	17
e033351d	18	/* Module and version information */
7944d3a5	19	#define DRV_NAME "iTCO_vendor_support"
55e8ddec	20	#define DRV_VERSION "1.04"
e033351d WVS	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 */
0e6fa3fb AC	30	#include <linux/io.h> /* For inb/outb/... */
	31
	32	#include "iTCO_vendor.h"
e033351d	33
e033351d	34	/* List of vendor support modes */
0e6fa3fb AC	35	/* SuperMicro Pentium 3 Era 370SSE+-OEM1/P3TSSE */
0e6fa3fb AC	36	#define SUPERMICRO_OLD_BOARD 1
2c05318a	37	/* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems - no longer supported */
0e6fa3fb	38	#define SUPERMICRO_NEW_BOARD 2
55e8ddec WVS	39	/* Broken BIOS */
55e8ddec WVS	40	#define BROKEN_BIOS 911
e033351d	41
0e6fa3fb	42	static int vendorsupport;
e033351d	43	module_param(vendorsupport, int, 0);
143a2e54	44	MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default="
2c05318a	45	"0 (none), 1=SuperMicro Pent3, 911=Broken SMI BIOS");
e033351d WVS	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
887c8ec7	75	static void supermicro_old_pre_start(struct resource *smires)
12d60e28 WVS	76	{
	77	unsigned long val32;
	78
	79	/* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */
887c8ec7	80	val32 = inl(smires->start);
12d60e28	81	val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */
887c8ec7	82	outl(val32, smires->start); /* Needed to activate watchdog */
12d60e28 WVS	83	}
12d60e28 WVS	84
887c8ec7	85	static void supermicro_old_pre_stop(struct resource *smires)
12d60e28 WVS	86	{
	87	unsigned long val32;
	88
	89	/* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */
887c8ec7	90	val32 = inl(smires->start);
12d60e28	91	val32 \|= 0x00002000; /* Turn on SMI clearing watchdog */
887c8ec7	92	outl(val32, smires->start); /* Needed to deactivate watchdog */
12d60e28 WVS	93	}
12d60e28 WVS	94
55e8ddec WVS	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
887c8ec7	126	static void broken_bios_start(struct resource *smires)
55e8ddec WVS	127	{
	128	unsigned long val32;
	129
887c8ec7	130	val32 = inl(smires->start);
55e8ddec WVS	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;
887c8ec7	134	outl(val32, smires->start);
55e8ddec WVS	135	}
55e8ddec WVS	136
887c8ec7	137	static void broken_bios_stop(struct resource *smires)
55e8ddec WVS	138	{
	139	unsigned long val32;
	140
887c8ec7	141	val32 = inl(smires->start);
55e8ddec WVS	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;
887c8ec7	145	outl(val32, smires->start);
55e8ddec WVS	146	}
55e8ddec WVS	147
e033351d WVS	148	/*
	149	* Generic Support Functions
	150	*/
	151
887c8ec7	152	void iTCO_vendor_pre_start(struct resource *smires,
e033351d WVS	153	unsigned int heartbeat)
e033351d WVS	154	{
55e8ddec WVS	155	switch (vendorsupport) {
55e8ddec WVS	156	case SUPERMICRO_OLD_BOARD:
887c8ec7	157	supermicro_old_pre_start(smires);
55e8ddec	158	break;
55e8ddec	159	case BROKEN_BIOS:
887c8ec7	160	broken_bios_start(smires);
55e8ddec WVS	161	break;
55e8ddec WVS	162	}
e033351d WVS	163	}
	164	EXPORT_SYMBOL(iTCO_vendor_pre_start);
	165
887c8ec7	166	void iTCO_vendor_pre_stop(struct resource *smires)
e033351d	167	{
55e8ddec WVS	168	switch (vendorsupport) {
55e8ddec WVS	169	case SUPERMICRO_OLD_BOARD:
887c8ec7	170	supermicro_old_pre_stop(smires);
55e8ddec	171	break;
55e8ddec	172	case BROKEN_BIOS:
887c8ec7	173	broken_bios_stop(smires);
55e8ddec WVS	174	break;
55e8ddec WVS	175	}
e033351d WVS	176	}
	177	EXPORT_SYMBOL(iTCO_vendor_pre_stop);
	178
e033351d WVS	179	int iTCO_vendor_check_noreboot_on(void)
e033351d WVS	180	{
0e6fa3fb	181	switch (vendorsupport) {
e033351d WVS	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	{
2c05318a JD	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	}
27c766aa	198	pr_info("vendor-support=%d\n", vendorsupport);
e033351d WVS	199	return 0;
	200	}
	201
	202	static void __exit iTCO_vendor_exit_module(void)
	203	{
27c766aa	204	pr_info("Module Unloaded\n");
e033351d WVS	205	}
	206
	207	module_init(iTCO_vendor_init_module);
	208	module_exit(iTCO_vendor_exit_module);
	209
143a2e54 WVS	210	MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, "
143a2e54 WVS	211	"R. Seretny <lkpatches@paypc.com>");
e033351d WVS	212	MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
	213	MODULE_VERSION(DRV_VERSION);
	214	MODULE_LICENSE("GPL");