2021-10-08 15:28:38

by Guenter Roeck

[permalink] [raw]
Subject: [PATCH] watchdog: iTCO: Drop vendor support

iTCO vendor support was introduced in 2006 to support SuperMicro boards
with Pentium 3 CPUs. It was extended in 2009 to support motherbords
with broken BIOS (specifically Intel DG33TL). The code is long since
obsolete, so let's drop support for it.

Signed-off-by: Guenter Roeck <[email protected]>
---
.../watchdog/watchdog-parameters.rst | 7 -
drivers/watchdog/Kconfig | 8 -
drivers/watchdog/Makefile | 3 -
drivers/watchdog/iTCO_vendor.h | 14 --
drivers/watchdog/iTCO_vendor_support.c | 216 ------------------
drivers/watchdog/iTCO_wdt.c | 17 --
6 files changed, 265 deletions(-)
delete mode 100644 drivers/watchdog/iTCO_vendor.h
delete mode 100644 drivers/watchdog/iTCO_vendor_support.c

diff --git a/Documentation/watchdog/watchdog-parameters.rst b/Documentation/watchdog/watchdog-parameters.rst
index 223c99361a30..60ecbd53e6aa 100644
--- a/Documentation/watchdog/watchdog-parameters.rst
+++ b/Documentation/watchdog/watchdog-parameters.rst
@@ -219,13 +219,6 @@ iTCO_wdt:

-------------------------------------------------

-iTCO_vendor_support:
- vendorsupport:
- iTCO vendor specific support mode, default=0 (none),
- 1=SuperMicro Pent3, 2=SuperMicro Pent4+, 911=Broken SMI BIOS
-
--------------------------------------------------
-
ib700wdt:
timeout:
Watchdog timeout in seconds. 0<= timeout <=30, default=30.
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bf59faeb3de1..3fae89be0e27 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1233,14 +1233,6 @@ config ITCO_WDT
To compile this driver as a module, choose M here: the
module will be called iTCO_wdt.

-config ITCO_VENDOR_SUPPORT
- bool "Intel TCO Timer/Watchdog Specific Vendor Support"
- depends on ITCO_WDT
- help
- Add vendor specific support to the intel TCO timer based watchdog
- devices. At this moment we only have additional support for some
- SuperMicro Inc. motherboards.
-
config IT8712F_WDT
tristate "IT8712F (Smart Guardian) Watchdog Timer"
depends on X86
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 1bd2d6f37c53..b05a7e611308 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -113,9 +113,6 @@ obj-$(CONFIG_WAFER_WDT) += wafer5823wdt.o
obj-$(CONFIG_I6300ESB_WDT) += i6300esb.o
obj-$(CONFIG_IE6XX_WDT) += ie6xx_wdt.o
obj-$(CONFIG_ITCO_WDT) += iTCO_wdt.o
-ifeq ($(CONFIG_ITCO_VENDOR_SUPPORT),y)
-obj-$(CONFIG_ITCO_WDT) += iTCO_vendor_support.o
-endif
obj-$(CONFIG_IT8712F_WDT) += it8712f_wdt.o
obj-$(CONFIG_IT87_WDT) += it87_wdt.o
obj-$(CONFIG_HP_WATCHDOG) += hpwdt.o
diff --git a/drivers/watchdog/iTCO_vendor.h b/drivers/watchdog/iTCO_vendor.h
deleted file mode 100644
index 69e92e692ae0..000000000000
--- a/drivers/watchdog/iTCO_vendor.h
+++ /dev/null
@@ -1,14 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/* iTCO Vendor Specific Support hooks */
-#ifdef CONFIG_ITCO_VENDOR_SUPPORT
-extern int iTCO_vendorsupport;
-extern void iTCO_vendor_pre_start(struct resource *, unsigned int);
-extern void iTCO_vendor_pre_stop(struct resource *);
-extern int iTCO_vendor_check_noreboot_on(void);
-#else
-#define iTCO_vendorsupport 0
-#define iTCO_vendor_pre_start(acpibase, heartbeat) {}
-#define iTCO_vendor_pre_stop(acpibase) {}
-#define iTCO_vendor_check_noreboot_on() 1
- /* 1=check noreboot; 0=don't check */
-#endif
diff --git a/drivers/watchdog/iTCO_vendor_support.c b/drivers/watchdog/iTCO_vendor_support.c
deleted file mode 100644
index cf0eaa04b064..000000000000
--- a/drivers/watchdog/iTCO_vendor_support.c
+++ /dev/null
@@ -1,216 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * intel TCO vendor specific watchdog driver support
- *
- * (c) Copyright 2006-2009 Wim Van Sebroeck <[email protected]>.
- *
- * 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
-
-int iTCO_vendorsupport;
-EXPORT_SYMBOL(iTCO_vendorsupport);
-
-module_param_named(vendorsupport, iTCO_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 <[email protected]>
- * 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 <[email protected]> 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 (iTCO_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 (iTCO_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 (iTCO_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 (iTCO_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", iTCO_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 <[email protected]>, "
- "R. Seretny <[email protected]>");
-MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
-MODULE_VERSION(DRV_VERSION);
-MODULE_LICENSE("GPL");
diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index ced2fc0deb8c..fc0ed665f7db 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -64,8 +64,6 @@
#include <linux/platform_data/itco_wdt.h>
#include <linux/mfd/intel_pmc_bxt.h>

-#include "iTCO_vendor.h"
-
/* Address definitions for the TCO */
/* TCO base address */
#define TCOBASE(p) ((p)->tco_res->start)
@@ -272,8 +270,6 @@ static int iTCO_wdt_start(struct watchdog_device *wd_dev)

spin_lock(&p->io_lock);

- iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
-
/* disable chipset's NO_REBOOT bit */
if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
spin_unlock(&p->io_lock);
@@ -307,8 +303,6 @@ static int iTCO_wdt_stop(struct watchdog_device *wd_dev)

spin_lock(&p->io_lock);

- iTCO_vendor_pre_stop(p->smi_res);
-
/* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
val = inw(TCO1_CNT(p));
val |= 0x0800;
@@ -483,10 +477,6 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
(u64)SMI_EN(p));
return -EBUSY;
}
- } else if (iTCO_vendorsupport ||
- turn_SMI_watchdog_clear_off >= p->iTCO_version) {
- dev_err(dev, "SMI I/O resource is missing\n");
- return -ENODEV;
}

iTCO_wdt_no_reboot_bit_setup(p, pdev, pdata);
@@ -505,13 +495,6 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
return PTR_ERR(p->gcs_pmc);
}

- /* Check chipset's NO_REBOOT bit */
- if (p->update_no_reboot_bit(p->no_reboot_priv, false) &&
- iTCO_vendor_check_noreboot_on()) {
- dev_info(dev, "unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
- return -ENODEV; /* Cannot reset NO_REBOOT bit */
- }
-
/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
p->update_no_reboot_bit(p->no_reboot_priv, true);

--
2.33.0


2021-10-27 00:15:06

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH] watchdog: iTCO: Drop vendor support

On 10/8/21 8:26 AM, Guenter Roeck wrote:
> iTCO vendor support was introduced in 2006 to support SuperMicro boards
> with Pentium 3 CPUs. It was extended in 2009 to support motherbords
> with broken BIOS (specifically Intel DG33TL). The code is long since
> obsolete, so let's drop support for it.
>
> Signed-off-by: Guenter Roeck <[email protected]>

Wim - this patch is buggy. Please don't apply it.

Guenter

> ---
> .../watchdog/watchdog-parameters.rst | 7 -
> drivers/watchdog/Kconfig | 8 -
> drivers/watchdog/Makefile | 3 -
> drivers/watchdog/iTCO_vendor.h | 14 --
> drivers/watchdog/iTCO_vendor_support.c | 216 ------------------
> drivers/watchdog/iTCO_wdt.c | 17 --
> 6 files changed, 265 deletions(-)
> delete mode 100644 drivers/watchdog/iTCO_vendor.h
> delete mode 100644 drivers/watchdog/iTCO_vendor_support.c
>
> diff --git a/Documentation/watchdog/watchdog-parameters.rst b/Documentation/watchdog/watchdog-parameters.rst
> index 223c99361a30..60ecbd53e6aa 100644
> --- a/Documentation/watchdog/watchdog-parameters.rst
> +++ b/Documentation/watchdog/watchdog-parameters.rst
> @@ -219,13 +219,6 @@ iTCO_wdt:
>
> -------------------------------------------------
>
> -iTCO_vendor_support:
> - vendorsupport:
> - iTCO vendor specific support mode, default=0 (none),
> - 1=SuperMicro Pent3, 2=SuperMicro Pent4+, 911=Broken SMI BIOS
> -
> --------------------------------------------------
> -
> ib700wdt:
> timeout:
> Watchdog timeout in seconds. 0<= timeout <=30, default=30.
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index bf59faeb3de1..3fae89be0e27 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1233,14 +1233,6 @@ config ITCO_WDT
> To compile this driver as a module, choose M here: the
> module will be called iTCO_wdt.
>
> -config ITCO_VENDOR_SUPPORT
> - bool "Intel TCO Timer/Watchdog Specific Vendor Support"
> - depends on ITCO_WDT
> - help
> - Add vendor specific support to the intel TCO timer based watchdog
> - devices. At this moment we only have additional support for some
> - SuperMicro Inc. motherboards.
> -
> config IT8712F_WDT
> tristate "IT8712F (Smart Guardian) Watchdog Timer"
> depends on X86
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 1bd2d6f37c53..b05a7e611308 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -113,9 +113,6 @@ obj-$(CONFIG_WAFER_WDT) += wafer5823wdt.o
> obj-$(CONFIG_I6300ESB_WDT) += i6300esb.o
> obj-$(CONFIG_IE6XX_WDT) += ie6xx_wdt.o
> obj-$(CONFIG_ITCO_WDT) += iTCO_wdt.o
> -ifeq ($(CONFIG_ITCO_VENDOR_SUPPORT),y)
> -obj-$(CONFIG_ITCO_WDT) += iTCO_vendor_support.o
> -endif
> obj-$(CONFIG_IT8712F_WDT) += it8712f_wdt.o
> obj-$(CONFIG_IT87_WDT) += it87_wdt.o
> obj-$(CONFIG_HP_WATCHDOG) += hpwdt.o
> diff --git a/drivers/watchdog/iTCO_vendor.h b/drivers/watchdog/iTCO_vendor.h
> deleted file mode 100644
> index 69e92e692ae0..000000000000
> --- a/drivers/watchdog/iTCO_vendor.h
> +++ /dev/null
> @@ -1,14 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/* iTCO Vendor Specific Support hooks */
> -#ifdef CONFIG_ITCO_VENDOR_SUPPORT
> -extern int iTCO_vendorsupport;
> -extern void iTCO_vendor_pre_start(struct resource *, unsigned int);
> -extern void iTCO_vendor_pre_stop(struct resource *);
> -extern int iTCO_vendor_check_noreboot_on(void);
> -#else
> -#define iTCO_vendorsupport 0
> -#define iTCO_vendor_pre_start(acpibase, heartbeat) {}
> -#define iTCO_vendor_pre_stop(acpibase) {}
> -#define iTCO_vendor_check_noreboot_on() 1
> - /* 1=check noreboot; 0=don't check */
> -#endif
> diff --git a/drivers/watchdog/iTCO_vendor_support.c b/drivers/watchdog/iTCO_vendor_support.c
> deleted file mode 100644
> index cf0eaa04b064..000000000000
> --- a/drivers/watchdog/iTCO_vendor_support.c
> +++ /dev/null
> @@ -1,216 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0+
> -/*
> - * intel TCO vendor specific watchdog driver support
> - *
> - * (c) Copyright 2006-2009 Wim Van Sebroeck <[email protected]>.
> - *
> - * 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
> -
> -int iTCO_vendorsupport;
> -EXPORT_SYMBOL(iTCO_vendorsupport);
> -
> -module_param_named(vendorsupport, iTCO_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 <[email protected]>
> - * 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 <[email protected]> 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 (iTCO_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 (iTCO_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 (iTCO_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 (iTCO_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", iTCO_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 <[email protected]>, "
> - "R. Seretny <[email protected]>");
> -MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
> -MODULE_VERSION(DRV_VERSION);
> -MODULE_LICENSE("GPL");
> diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
> index ced2fc0deb8c..fc0ed665f7db 100644
> --- a/drivers/watchdog/iTCO_wdt.c
> +++ b/drivers/watchdog/iTCO_wdt.c
> @@ -64,8 +64,6 @@
> #include <linux/platform_data/itco_wdt.h>
> #include <linux/mfd/intel_pmc_bxt.h>
>
> -#include "iTCO_vendor.h"
> -
> /* Address definitions for the TCO */
> /* TCO base address */
> #define TCOBASE(p) ((p)->tco_res->start)
> @@ -272,8 +270,6 @@ static int iTCO_wdt_start(struct watchdog_device *wd_dev)
>
> spin_lock(&p->io_lock);
>
> - iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
> -
> /* disable chipset's NO_REBOOT bit */
> if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
> spin_unlock(&p->io_lock);
> @@ -307,8 +303,6 @@ static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
>
> spin_lock(&p->io_lock);
>
> - iTCO_vendor_pre_stop(p->smi_res);
> -
> /* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
> val = inw(TCO1_CNT(p));
> val |= 0x0800;
> @@ -483,10 +477,6 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
> (u64)SMI_EN(p));
> return -EBUSY;
> }
> - } else if (iTCO_vendorsupport ||
> - turn_SMI_watchdog_clear_off >= p->iTCO_version) {
> - dev_err(dev, "SMI I/O resource is missing\n");
> - return -ENODEV;
> }
>
> iTCO_wdt_no_reboot_bit_setup(p, pdev, pdata);
> @@ -505,13 +495,6 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
> return PTR_ERR(p->gcs_pmc);
> }
>
> - /* Check chipset's NO_REBOOT bit */
> - if (p->update_no_reboot_bit(p->no_reboot_priv, false) &&
> - iTCO_vendor_check_noreboot_on()) {
> - dev_info(dev, "unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
> - return -ENODEV; /* Cannot reset NO_REBOOT bit */
> - }
> -
> /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
> p->update_no_reboot_bit(p->no_reboot_priv, true);
>
>

2021-10-27 09:27:05

by Wim Van Sebroeck

[permalink] [raw]
Subject: Re: [PATCH] watchdog: iTCO: Drop vendor support

Hi Guenter,

> On 10/8/21 8:26 AM, Guenter Roeck wrote:
> >iTCO vendor support was introduced in 2006 to support SuperMicro boards
> >with Pentium 3 CPUs. It was extended in 2009 to support motherbords
> >with broken BIOS (specifically Intel DG33TL). The code is long since
> >obsolete, so let's drop support for it.
> >
> >Signed-off-by: Guenter Roeck <[email protected]>
>
> Wim - this patch is buggy. Please don't apply it.

Noted.

Kind regards,
Wim.