diff options
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 20 | ||||
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 56 | ||||
| -rw-r--r-- | include/linux/watchdog.h | 11 |
3 files changed, 85 insertions, 2 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index 7f31125c123e..3402dcad5b03 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -50,6 +50,7 @@ struct watchdog_device { const struct watchdog_ops *ops; unsigned int bootstatus; unsigned int timeout; + unsigned int pretimeout; unsigned int min_timeout; unsigned int max_timeout; unsigned int min_hw_heartbeat_ms; @@ -77,6 +78,7 @@ It contains following fields: * timeout: the watchdog timer's timeout value (in seconds). This is the time after which the system will reboot if user space does not send a heartbeat request if WDOG_ACTIVE is set. +* pretimeout: the watchdog timer's pretimeout value (in seconds). * min_timeout: the watchdog timer's minimum timeout value (in seconds). If set, the minimum configurable value for 'timeout'. * max_timeout: the watchdog timer's maximum timeout value (in seconds), @@ -121,6 +123,7 @@ struct watchdog_ops { int (*ping)(struct watchdog_device *); unsigned int (*status)(struct watchdog_device *); int (*set_timeout)(struct watchdog_device *, unsigned int); + int (*set_pretimeout)(struct watchdog_device *, unsigned int); unsigned int (*get_timeleft)(struct watchdog_device *); int (*restart)(struct watchdog_device *); void (*ref)(struct watchdog_device *) __deprecated; @@ -188,6 +191,23 @@ they are supported. These optional routines/operations are: If set_timeout is not provided but, WDIOF_SETTIMEOUT is set, the watchdog infrastructure updates the timeout value of the watchdog_device internally to the requested value. + If the pretimeout feature is used (WDIOF_PRETIMEOUT), then set_timeout must + also take care of checking if pretimeout is still valid and set up the timer + accordingly. This can't be done in the core without races, so it is the + duty of the driver. +* set_pretimeout: this routine checks and changes the pretimeout value of + the watchdog. It is optional because not all watchdogs support pretimeout + notification. The timeout value is not an absolute time, but the number of + seconds before the actual timeout would happen. It returns 0 on success, + -EINVAL for "parameter out of range" and -EIO for "could not write value to + the watchdog". A value of 0 disables pretimeout notification. + (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the + watchdog's info structure). + If the watchdog driver does not have to perform any action but setting the + watchdog_device.pretimeout, this callback can be omitted. That means if + set_pretimeout is not provided but WDIOF_PRETIMEOUT is set, the watchdog + infrastructure updates the pretimeout value of the watchdog_device internally + to the requested value. * get_timeleft: this routines returns the time that's left before a reset. * restart: this routine restarts the machine. It returns 0 on success or a negative errno code for failure. diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 040bf8382f46..4b381a6be2ff 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -335,10 +335,14 @@ static int watchdog_set_timeout(struct watchdog_device *wdd, if (watchdog_timeout_invalid(wdd, timeout)) return -EINVAL; - if (wdd->ops->set_timeout) + if (wdd->ops->set_timeout) { err = wdd->ops->set_timeout(wdd, timeout); - else + } else { wdd->timeout = timeout; + /* Disable pretimeout if it doesn't fit the new timeout */ + if (wdd->pretimeout >= wdd->timeout) + wdd->pretimeout = 0; + } watchdog_update_worker(wdd); @@ -346,6 +350,31 @@ static int watchdog_set_timeout(struct watchdog_device *wdd, } /* + * watchdog_set_pretimeout: set the watchdog timer pretimeout + * @wdd: the watchdog device to set the timeout for + * @timeout: pretimeout to set in seconds + */ + +static int watchdog_set_pretimeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + int err = 0; + + if (!(wdd->info->options & WDIOF_PRETIMEOUT)) + return -EOPNOTSUPP; + + if (watchdog_pretimeout_invalid(wdd, timeout)) + return -EINVAL; + + if (wdd->ops->set_pretimeout) + err = wdd->ops->set_pretimeout(wdd, timeout); + else + wdd->pretimeout = timeout; + + return err; +} + +/* * watchdog_get_timeleft: wrapper to get the time left before a reboot * @wdd: the watchdog device to get the remaining time from * @timeleft: the time that's left @@ -429,6 +458,15 @@ static ssize_t timeout_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(timeout); +static ssize_t pretimeout_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", wdd->pretimeout); +} +static DEVICE_ATTR_RO(pretimeout); + static ssize_t identity_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -459,6 +497,9 @@ static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr, if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft) mode = 0; + else if (attr == &dev_attr_pretimeout.attr && + !(wdd->info->options & WDIOF_PRETIMEOUT)) + mode = 0; return mode; } @@ -466,6 +507,7 @@ static struct attribute *wdt_attrs[] = { &dev_attr_state.attr, &dev_attr_identity.attr, &dev_attr_timeout.attr, + &dev_attr_pretimeout.attr, &dev_attr_timeleft.attr, &dev_attr_bootstatus.attr, &dev_attr_status.attr, @@ -646,6 +688,16 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, break; err = put_user(val, p); break; + case WDIOC_SETPRETIMEOUT: + if (get_user(val, p)) { + err = -EFAULT; + break; + } + err = watchdog_set_pretimeout(wdd, val); + break; + case WDIOC_GETPRETIMEOUT: + err = put_user(wdd->pretimeout, p); + break; default: err = -ENOTTY; break; diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h index 7047bc7f8106..4035df7ec023 100644 --- a/include/linux/watchdog.h +++ b/include/linux/watchdog.h @@ -28,6 +28,7 @@ struct watchdog_core_data; * @ping: The routine that sends a keepalive ping to the watchdog device. * @status: The routine that shows the status of the watchdog device. * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds). + * @set_pretimeout:The routine for setting the watchdog devices pretimeout. * @get_timeleft:The routine that gets the time left before a reset (in seconds). * @restart: The routine for restarting the machine. * @ioctl: The routines that handles extra ioctl calls. @@ -46,6 +47,7 @@ struct watchdog_ops { int (*ping)(struct watchdog_device *); unsigned int (*status)(struct watchdog_device *); int (*set_timeout)(struct watchdog_device *, unsigned int); + int (*set_pretimeout)(struct watchdog_device *, unsigned int); unsigned int (*get_timeleft)(struct watchdog_device *); int (*restart)(struct watchdog_device *, unsigned long, void *); long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long); @@ -61,6 +63,7 @@ struct watchdog_ops { * @ops: Pointer to the list of watchdog operations. * @bootstatus: Status of the watchdog device at boot. * @timeout: The watchdog devices timeout value (in seconds). + * @pretimeout: The watchdog devices pre_timeout value. * @min_timeout:The watchdog devices minimum timeout value (in seconds). * @max_timeout:The watchdog devices maximum timeout value (in seconds) * as configurable from user space. Only relevant if @@ -96,6 +99,7 @@ struct watchdog_device { const struct watchdog_ops *ops; unsigned int bootstatus; unsigned int timeout; + unsigned int pretimeout; unsigned int min_timeout; unsigned int max_timeout; unsigned int min_hw_heartbeat_ms; @@ -163,6 +167,13 @@ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigne t > wdd->max_timeout); } +/* Use the following function to check if a pretimeout value is invalid */ +static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd, + unsigned int t) +{ + return t && wdd->timeout && t >= wdd->timeout; +} + /* Use the following functions to manipulate watchdog driver specific data */ static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data) { |