From f77710c4cda01ad9c3672fb2f97bdea9a94da92a Mon Sep 17 00:00:00 2001 From: Vladimir Zapolskiy Date: Fri, 7 Oct 2016 15:39:55 +0300 Subject: watchdog: pretimeout: add noop pretimeout governor The change adds noop watchdog pretimeout governor, only an informational message is printed to the kernel log buffer when a watchdog triggers a pretimeout event. While introducing the first pretimeout governor the selected design assumes that the default pretimeout governor is selected by its name and it is always built-in, thus the default pretimeout governor can not be unregistered and the correspondent check can be removed from the watchdog_unregister_governor() function. Signed-off-by: Vladimir Zapolskiy Reviewed-by: Guenter Roeck Reviewed-by: Wolfram Sang Tested-by: Wolfram Sang Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/Kconfig | 28 ++++++++++++++++++++ drivers/watchdog/Makefile | 2 ++ drivers/watchdog/pretimeout_noop.c | 47 ++++++++++++++++++++++++++++++++++ drivers/watchdog/watchdog_pretimeout.h | 4 +++ 4 files changed, 81 insertions(+) create mode 100644 drivers/watchdog/pretimeout_noop.c (limited to 'drivers') diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 04d535ae497d..4aeb8f95beb4 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1838,4 +1838,32 @@ config WATCHDOG_PRETIMEOUT_GOV help The option allows to select watchdog pretimeout governors. +if WATCHDOG_PRETIMEOUT_GOV + +choice + prompt "Default Watchdog Pretimeout Governor" + default WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC + help + This option selects a default watchdog pretimeout governor. + The governor takes its action, if a watchdog is capable + to report a pretimeout event. + +config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP + bool "noop" + select WATCHDOG_PRETIMEOUT_GOV_NOOP + help + Use noop watchdog pretimeout governor by default. If noop + governor is selected by a user, write a short message to + the kernel log buffer and don't do any system changes. + +endchoice + +config WATCHDOG_PRETIMEOUT_GOV_NOOP + tristate "Noop watchdog pretimeout governor" + help + Noop watchdog pretimeout governor, only an informational + message is added to kernel log buffer. + +endif # WATCHDOG_PRETIMEOUT_GOV + endif # WATCHDOG diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 990c36ed4716..0502a21db1db 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -9,6 +9,8 @@ watchdog-objs += watchdog_core.o watchdog_dev.o watchdog-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV) += watchdog_pretimeout.o +obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_NOOP) += pretimeout_noop.o + # Only one watchdog can succeed. We probe the ISA/PCI/USB based # watchdog-cards first, then the architecture specific watchdog # drivers and then the architecture independent "softdog" driver. diff --git a/drivers/watchdog/pretimeout_noop.c b/drivers/watchdog/pretimeout_noop.c new file mode 100644 index 000000000000..85f5299d197c --- /dev/null +++ b/drivers/watchdog/pretimeout_noop.c @@ -0,0 +1,47 @@ +/* + * Copyright (C) 2015-2016 Mentor Graphics + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include +#include +#include + +#include "watchdog_pretimeout.h" + +/** + * pretimeout_noop - No operation on watchdog pretimeout event + * @wdd - watchdog_device + * + * This function prints a message about pretimeout to kernel log. + */ +static void pretimeout_noop(struct watchdog_device *wdd) +{ + pr_alert("watchdog%d: pretimeout event\n", wdd->id); +} + +static struct watchdog_governor watchdog_gov_noop = { + .name = "noop", + .pretimeout = pretimeout_noop, +}; + +static int __init watchdog_gov_noop_register(void) +{ + return watchdog_register_governor(&watchdog_gov_noop); +} + +static void __exit watchdog_gov_noop_unregister(void) +{ + watchdog_unregister_governor(&watchdog_gov_noop); +} +module_init(watchdog_gov_noop_register); +module_exit(watchdog_gov_noop_unregister); + +MODULE_AUTHOR("Vladimir Zapolskiy "); +MODULE_DESCRIPTION("Panic watchdog pretimeout governor"); +MODULE_LICENSE("GPL"); diff --git a/drivers/watchdog/watchdog_pretimeout.h b/drivers/watchdog/watchdog_pretimeout.h index c6cd9f80adb2..c4b6f88dc9c9 100644 --- a/drivers/watchdog/watchdog_pretimeout.h +++ b/drivers/watchdog/watchdog_pretimeout.h @@ -20,6 +20,10 @@ int watchdog_register_pretimeout(struct watchdog_device *wdd); void watchdog_unregister_pretimeout(struct watchdog_device *wdd); int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf); +#if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP) +#define WATCHDOG_PRETIMEOUT_DEFAULT_GOV "noop" +#endif + #else static inline int watchdog_register_pretimeout(struct watchdog_device *wdd) { -- cgit v1.2.1