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author | Damien Riegel <damien.riegel@savoirfairelinux.com> | 2015-11-16 12:27:59 -0500 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2015-12-13 15:27:10 +0100 |
commit | 2165bf524da5f5e496d1cdb8c5afae1345ecce1e (patch) | |
tree | 75a24ea774d08021e1c45e201ffc9f7a164ca661 /drivers/watchdog/watchdog_core.c | |
parent | 1f32f83e5d81c1e99a1c16366e71d5867cd1e364 (diff) | |
download | op-kernel-dev-2165bf524da5f5e496d1cdb8c5afae1345ecce1e.zip op-kernel-dev-2165bf524da5f5e496d1cdb8c5afae1345ecce1e.tar.gz |
watchdog: core: add restart handler support
Many watchdog drivers implement the same code to register a restart
handler. This patch provides a generic way to set such a function.
The patch adds a new restart watchdog operation. If a restart priority
greater than 0 is needed, the driver can call
watchdog_set_restart_priority to set it.
Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/watchdog_core.c')
-rw-r--r-- | drivers/watchdog/watchdog_core.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index 873f139..88a34ef 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -32,6 +32,7 @@ #include <linux/types.h> /* For standard types */ #include <linux/errno.h> /* For the -ENODEV/... values */ #include <linux/kernel.h> /* For printk/panic/... */ +#include <linux/reboot.h> /* For restart handler */ #include <linux/watchdog.h> /* For watchdog specific items */ #include <linux/init.h> /* For __init/__exit/... */ #include <linux/idr.h> /* For ida_* macros */ @@ -137,6 +138,41 @@ int watchdog_init_timeout(struct watchdog_device *wdd, } EXPORT_SYMBOL_GPL(watchdog_init_timeout); +static int watchdog_restart_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct watchdog_device *wdd = container_of(nb, struct watchdog_device, + restart_nb); + + int ret; + + ret = wdd->ops->restart(wdd); + if (ret) + return NOTIFY_BAD; + + return NOTIFY_DONE; +} + +/** + * watchdog_set_restart_priority - Change priority of restart handler + * @wdd: watchdog device + * @priority: priority of the restart handler, should follow these guidelines: + * 0: use watchdog's restart function as last resort, has limited restart + * capabilies + * 128: default restart handler, use if no other handler is expected to be + * available and/or if restart is sufficient to restart the entire system + * 255: preempt all other handlers + * + * If a wdd->ops->restart function is provided when watchdog_register_device is + * called, it will be registered as a restart handler with the priority given + * here. + */ +void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority) +{ + wdd->restart_nb.priority = priority; +} +EXPORT_SYMBOL_GPL(watchdog_set_restart_priority); + static int __watchdog_register_device(struct watchdog_device *wdd) { int ret, id = -1, devno; @@ -202,6 +238,15 @@ static int __watchdog_register_device(struct watchdog_device *wdd) return ret; } + if (wdd->ops->restart) { + wdd->restart_nb.notifier_call = watchdog_restart_notifier; + + ret = register_restart_handler(&wdd->restart_nb); + if (ret) + dev_warn(wdd->dev, "Cannot register restart handler (%d)\n", + ret); + } + return 0; } @@ -238,6 +283,9 @@ static void __watchdog_unregister_device(struct watchdog_device *wdd) if (wdd == NULL) return; + if (wdd->ops->restart) + unregister_restart_handler(&wdd->restart_nb); + devno = wdd->cdev.dev; ret = watchdog_dev_unregister(wdd); if (ret) |