| Message ID | 1433217907-928-5-git-send-email-fu.wei@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi Guenter, Great thanks for your review, On 3 June 2015 at 00:12, Guenter Roeck <linux@roeck-us.net> wrote: > On 06/01/2015 09:05 PM, fu.wei@linaro.org wrote: >> >> From: Fu Wei <fu.wei@linaro.org> >> >> Also update Documentation/watchdog/watchdog-kernel-api.txt to >> introduce: >> (1)the new elements in the watchdog_device and watchdog_ops struct; >> (2)the new API "watchdog_init_timeouts" >> >> Reasons: >> (1)kernel already has two watchdog drivers are using "pretimeout": >> drivers/char/ipmi/ipmi_watchdog.c >> drivers/watchdog/kempld_wdt.c(but the definition is different) >> (2)some other drivers are going to use this: ARM SBSA Generic Watchdog >> >> Signed-off-by: Fu Wei <fu.wei@linaro.org> >> --- >> Documentation/watchdog/watchdog-kernel-api.txt | 47 ++++++++-- >> drivers/watchdog/watchdog_core.c | 115 >> +++++++++++++++++++------ >> drivers/watchdog/watchdog_dev.c | 53 ++++++++++++ >> include/linux/watchdog.h | 33 ++++++- >> 4 files changed, 212 insertions(+), 36 deletions(-) >> >> diff --git a/Documentation/watchdog/watchdog-kernel-api.txt >> b/Documentation/watchdog/watchdog-kernel-api.txt >> index a0438f3..95b355d 100644 >> --- a/Documentation/watchdog/watchdog-kernel-api.txt >> +++ b/Documentation/watchdog/watchdog-kernel-api.txt >> @@ -49,6 +49,9 @@ struct watchdog_device { >> unsigned int timeout; >> unsigned int min_timeout; >> unsigned int max_timeout; >> + unsigned int pretimeout; >> + unsigned int min_pretimeout; >> + unsigned int max_pretimeout; >> void *driver_data; >> struct mutex lock; >> unsigned long status; >> @@ -70,6 +73,9 @@ It contains following fields: >> * timeout: the watchdog timer's timeout value (in seconds). >> * min_timeout: the watchdog timer's minimum timeout value (in seconds). >> * max_timeout: the watchdog timer's maximum timeout value (in seconds). >> +* pretimeout: the watchdog timer's pretimeout value (in seconds). >> +* min_pretimeout: the watchdog timer's minimum pretimeout value (in >> seconds). >> +* max_pretimeout: the watchdog timer's maximum pretimeout value (in >> seconds). >> * bootstatus: status of the device after booting (reported with watchdog >> WDIOF_* status bits). >> * driver_data: a pointer to the drivers private data of a watchdog >> device. >> @@ -92,6 +98,7 @@ 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 *); >> void (*ref)(struct watchdog_device *); >> void (*unref)(struct watchdog_device *); >> @@ -153,9 +160,19 @@ they are supported. These optional >> routines/operations are: >> and -EIO for "could not write value to the watchdog". On success this >> routine should set the timeout value of the watchdog_device to the >> achieved timeout value (which may be different from the requested one >> - because the watchdog does not necessarily has a 1 second resolution). >> + because the watchdog does not necessarily has a 1 second resolution; >> + If the driver supports pretimeout, then the timeout value must be >> greater >> + than that). >> (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of >> the >> watchdog's info structure). >> +* set_pretimeout: this routine checks and changes the pretimeout of the >> + watchdog timer device. It returns 0 on success, -EINVAL for "parameter >> out of >> + range" and -EIO for "could not write value to the watchdog". On success >> this >> + routine should set the pretimeout value of the watchdog_device to the >> + achieved pretimeout value (which may be different from the requested >> one >> + because the watchdog does not necessarily has a 1 second resolution). >> + (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the >> + watchdog's info structure). >> * get_timeleft: this routines returns the time that's left before a >> reset. >> * ref: the operation that calls kref_get on the kref of a dynamically >> allocated watchdog_device struct. >> @@ -219,8 +236,28 @@ extern int watchdog_init_timeout(struct >> watchdog_device *wdd, >> unsigned int timeout_parm, struct >> device *dev); >> >> The watchdog_init_timeout function allows you to initialize the timeout >> field >> -using the module timeout parameter or by retrieving the timeout-sec >> property from >> -the device tree (if the module timeout parameter is invalid). Best >> practice is >> -to set the default timeout value as timeout value in the watchdog_device >> and >> -then use this function to set the user "preferred" timeout value. >> +using the module timeout parameter or by retrieving the first element of >> +the timeout-sec property from the device tree (if the module timeout >> parameter >> +is invalid). Best practice is to set the default timeout value as timeout >> value >> +in the watchdog_device and then use this function to set the user >> "preferred" >> +timeout value. >> +This routine returns zero on success and a negative errno code for >> failure. >> + >> +Some watchdog timers have two stage of timeouts(timeout and pretimeout), >> +to initialize the timeout and pretimeout fields at the same time, the >> following >> +function can be used: >> + >> +extern int watchdog_init_timeouts(struct watchdog_device *wdd, >> + unsigned int pretimeout_parm, >> + unsigned int timeout_parm, >> + struct device *dev); >> + >> +The watchdog_init_timeouts function allows you to initialize the >> pretimeout and >> +timeout fields using the module pretimeout and timeout parameter or by >> +retrieving the elements in the timeout-sec property(the first element is >> for >> +timeout, the second one is for pretimeout) from the device tree(if the >> module >> +pretimeout and timeout parameter are invalid). >> +Best practice is to set the default pretimeout and timeout value as >> pretimeout >> +and timeout value in the watchdog_device and then use this function to >> set the >> +user "preferred" pretimeout value. >> This routine returns zero on success and a negative errno code for >> failure. >> diff --git a/drivers/watchdog/watchdog_core.c >> b/drivers/watchdog/watchdog_core.c >> index cec9b55..ff18db3 100644 >> --- a/drivers/watchdog/watchdog_core.c >> +++ b/drivers/watchdog/watchdog_core.c >> @@ -43,60 +43,119 @@ >> static DEFINE_IDA(watchdog_ida); >> static struct class *watchdog_class; >> >> -static void watchdog_check_min_max_timeout(struct watchdog_device *wdd) >> +static void watchdog_check_min_max_timeouts(struct watchdog_device *wdd) >> { >> /* >> - * Check that we have valid min and max timeout values, if >> - * not reset them both to 0 (=not used or unknown) >> + * Check that we have valid min and max pretimeout and timeout >> values, >> + * if not reset them both to 0 (=not used or unknown) >> */ >> + if (wdd->min_pretimeout > wdd->max_pretimeout) { >> + pr_info("Invalid min and max pretimeout, resetting to >> 0\n"); >> + wdd->min_pretimeout = 0; >> + wdd->max_pretimeout = 0; >> + } >> if (wdd->min_timeout > wdd->max_timeout) { >> pr_info("Invalid min and max timeout values, resetting to >> 0!\n"); >> wdd->min_timeout = 0; >> wdd->max_timeout = 0; >> } >> + /* >> + * Check that we have valid min timeout and max pretimeout values, >> + * if not reset them. >> + */ >> + if (wdd->min_pretimeout && wdd->min_timeout < wdd->min_pretimeout) >> { >> + pr_info("Invalid min_timeout, resetting to >> min_pretimeout+1\n"); >> + wdd->min_timeout = wdd->min_pretimeout + 1; >> + } > > > min_timeout = 10 > max_timeout = 20 > min_pretimeout = 30 > max_pretimeout = 40 > > will result in min_timeout set to 31. > >> + if (wdd->max_pretimeout && wdd->max_timeout < wdd->max_pretimeout) >> { >> + pr_info("Invalid max_pretimeout, resetting to >> max_timeout-1\n"); >> + wdd->max_pretimeout = wdd->max_timeout - 1; > > > and then you set max_pretimeout to 19. > > So we'll end up with > > min_timeout = 31 > max_timeout = 20 > min_pretimeout = 30 > max_pretimeout = 19 > > Another example: max_pretimeout = 10, max_timeout = 0 -> max_pretimeout = > -1. > >> + } > > > You'll need to determine valid ranges and then enforce those. > Maybe something like > min_pretimeout < min_timeout < max_timeout > and > min_pretimeout < max_pretimeout < max_timeout > > Not sure if we should adjust anything to a value different to 0. > Seems to me this is just asking for trouble. yes, this is a new problem, but let me fix this in my new patchset: (1)these values is set by driver in the initialization procedure, according to hardware info. (2) I thinks there is not any driver should call this function after initialization. So if we find any incorrect value, I think the hardware info we got is wrong , maybe we can just give up any suggestion ? > >> } >> >> /** >> - * watchdog_init_timeout() - initialize the timeout field >> + * watchdog_init_timeouts() - initialize the pretimeout and timeout field >> + * @pretimeout_parm: pretimeout module parameter >> * @timeout_parm: timeout module parameter >> * @dev: Device that stores the timeout-sec property >> * >> - * Initialize the timeout field of the watchdog_device struct with either >> the >> - * timeout module parameter (if it is valid value) or the timeout-sec >> property >> - * (only if it is a valid value and the timeout_parm is out of bounds). >> - * If none of them are valid then we keep the old value (which should >> normally >> - * be the default timeout value. >> + * Initialize the pretimeout and timeout field of the watchdog_device >> struct >> + * with either the pretimeout and timeout module parameter (if it is >> valid >> + * value) or the timeout-sec property (only if it is a valid value and >> the > > > just 'if it is valid', or 'if it is a valid value' in both cases. OK. np,. Thanks > >> + * pretimeout_parm and timeout_parm is out of bounds). If none of them >> are > > > s/and/or/ Thanks , fixed > > >> + * valid, then we keep the old value (which should normally be the >> default >> + * timeout value). >> * >> * A zero is returned on success and -EINVAL for failure. >> */ >> -int watchdog_init_timeout(struct watchdog_device *wdd, >> - unsigned int timeout_parm, struct device >> *dev) >> +int watchdog_init_timeouts(struct watchdog_device *wdd, >> + unsigned int pretimeout_parm, >> + unsigned int timeout_parm, >> + struct device *dev) >> { >> - unsigned int t = 0; >> - int ret = 0; >> + int ret = 0, length = 0; >> + u32 timeouts[2] = {0}; >> >> - watchdog_check_min_max_timeout(wdd); >> + watchdog_check_min_max_timeouts(wdd); >> >> - /* try to get the timeout module parameter first */ >> - if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) >> { >> - wdd->timeout = timeout_parm; >> - return ret; >> + /* >> + * Try to get the pretimeout module parameter first, >> + * but it can be "0", that means we don't use pretimeout. >> + */ >> + if (pretimeout_parm) { >> + if (!watchdog_pretimeout_invalid(wdd, pretimeout_parm)) >> + timeouts[1] = pretimeout_parm; >> + ret = -EINVAL; /* pretimeout_parm is not "0", and invalid >> */ > > > pretimeout_parm is always invalid ? Why ? Sorry, I lost a "else" , this is a bug/typo > >> } >> - if (timeout_parm) >> + >> + /* >> + * Try to get the timeout module parameter, >> + * if it's valid and pretimeout is ont invalid(ret == 0), > > > s/ont/not/ Thanks , fixed > >> + * assignment and return zero. Otherwise, try dtb. >> + */ >> + if (timeout_parm) { >> + if (!watchdog_timeout_invalid(wdd, timeout_parm) && !ret) >> { > > > Unless I am missing something, you'll never get here if the pretimeout > module > parameter is set. yes, because of the bug above. Will fix it in my next patchset , thanks :-) > >> + wdd->timeout = timeout_parm; >> + wdd->pretimeout = timeouts[1]; >> + return 0; >> + } >> ret = -EINVAL; >> + } >> >> - /* try to get the timeout_sec property */ >> + /* >> + * We get here, the situation is one of them: >> + * (1)at least one of parameters is invalid(ret = -EINVAL); >> + * (2)both of them are 0.(ret = 0) >> + * So give up the module parameter(at least drop the invalid one), >> + * try to get the timeout_sec property from dtb. > > > Please simplify the comment. > > Either at least one of the module parameters is invalid, > or both of them are 0. Try to get the timeout_sec property. Thanks , will do. > >> + */ >> if (dev == NULL || dev->of_node == NULL) >> return ret; >> - of_property_read_u32(dev->of_node, "timeout-sec", &t); >> - if (!watchdog_timeout_invalid(wdd, t) && t) >> - wdd->timeout = t; >> - else >> - ret = -EINVAL; >> >> - return ret; >> + /* >> + * We get here, that means maybe we can get timeouts from dtb, >> + * if "timeout-sec" is available and the data is valid. >> + */ > > > That comment is not needed; it is obvious. OK, will remove it > >> + of_find_property(dev->of_node, "timeout-sec", &length); >> + if (length > 0 && length <= sizeof(u32) * 2) { > > > You need to check the return value of of_find_property() instead of assuming > that length will be 0 if it is not found. you are right, will do, thanks > >> + of_property_read_u32_array(dev->of_node, >> + "timeout-sec", timeouts, >> + length / sizeof(u32)); >> + if (length == sizeof(u32) * 2 && timeouts[1] && >> + watchdog_pretimeout_invalid(wdd, timeouts[1])) >> + return -EINVAL; /* pretimeout is invalid >> */ > > > Obvious comment. OK, will remove it > > >> + >> + if (!watchdog_timeout_invalid(wdd, timeouts[0]) && >> + timeouts[0]) { >> + wdd->timeout = timeouts[0]; >> + wdd->pretimeout = timeouts[1]; >> + return 0; >> + } >> + } >> + >> + return -EINVAL; >> } >> -EXPORT_SYMBOL_GPL(watchdog_init_timeout); >> +EXPORT_SYMBOL_GPL(watchdog_init_timeouts); >> >> /** >> * watchdog_register_device() - register a watchdog device >> @@ -119,7 +178,7 @@ int watchdog_register_device(struct watchdog_device >> *wdd) >> if (wdd->ops->start == NULL || wdd->ops->stop == NULL) >> return -EINVAL; >> >> - watchdog_check_min_max_timeout(wdd); >> + watchdog_check_min_max_timeouts(wdd); >> >> /* >> * Note: now that all watchdog_device data has been verified, we >> diff --git a/drivers/watchdog/watchdog_dev.c >> b/drivers/watchdog/watchdog_dev.c >> index 6aaefba..af0777e 100644 >> --- a/drivers/watchdog/watchdog_dev.c >> +++ b/drivers/watchdog/watchdog_dev.c >> @@ -218,6 +218,38 @@ out_timeout: >> } >> >> /* >> + * watchdog_set_pretimeout: set the watchdog timer pretimeout >> + * @wddev: the watchdog device to set the timeout for >> + * @pretimeout: pretimeout to set in seconds >> + */ >> + >> +static int watchdog_set_pretimeout(struct watchdog_device *wddev, >> + unsigned int pretimeout) >> +{ >> + int err; >> + >> + if (!wddev->ops->set_pretimeout || >> + !(wddev->info->options & WDIOF_PRETIMEOUT)) >> + return -EOPNOTSUPP; >> + >> + if (watchdog_pretimeout_invalid(wddev, pretimeout)) >> + return -EINVAL; >> + >> + mutex_lock(&wddev->lock); >> + >> + if (test_bit(WDOG_UNREGISTERED, &wddev->status)) { >> + err = -ENODEV; >> + goto out_pretimeout; >> + } >> + >> + err = wddev->ops->set_pretimeout(wddev, pretimeout); >> + >> +out_pretimeout: >> + mutex_unlock(&wddev->lock); >> + return err; >> +} >> + >> +/* >> * watchdog_get_timeleft: wrapper to get the time left before a >> reboot >> * @wddev: the watchdog device to get the remaining time from >> * @timeleft: the time that's left >> @@ -388,6 +420,27 @@ static long watchdog_ioctl(struct file *file, >> unsigned int cmd, >> if (wdd->timeout == 0) >> return -EOPNOTSUPP; >> return put_user(wdd->timeout, p); >> + case WDIOC_SETPRETIMEOUT: >> + /* check if we support the pretimeout */ >> + if (!(wdd->info->options & WDIOF_PRETIMEOUT)) >> + return -EOPNOTSUPP; >> + if (get_user(val, p)) >> + return -EFAULT; >> + err = watchdog_set_pretimeout(wdd, val); >> + if (err < 0) >> + return err; >> + /* >> + * If the watchdog is active then we send a keepalive ping >> + * to make sure that the watchdog keeps running (and if >> + * possible that it takes the new pretimeout) >> + */ >> + watchdog_ping(wdd); >> + /* Fall */ >> + case WDIOC_GETPRETIMEOUT: >> + /* check if we support the pretimeout */ >> + if (wdd->info->options & WDIOF_PRETIMEOUT) >> + return put_user(wdd->pretimeout, p); >> + return -EOPNOTSUPP; >> case WDIOC_GETTIMELEFT: >> err = watchdog_get_timeleft(wdd, &val); >> if (err) >> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h >> index a746bf5..b1e325d 100644 >> --- a/include/linux/watchdog.h >> +++ b/include/linux/watchdog.h >> @@ -25,6 +25,7 @@ struct watchdog_device; >> * @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. >> + * @set_pretimeout:The routine for setting the watchdog devices >> pretimeout value >> * @get_timeleft:The routine that get's the time that's left before a >> reset. >> * @ref: The ref operation for dyn. allocated watchdog_device >> structs >> * @unref: The unref operation for dyn. allocated watchdog_device >> structs >> @@ -44,6 +45,7 @@ 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 *); >> void (*ref)(struct watchdog_device *); >> void (*unref)(struct watchdog_device *); >> @@ -62,6 +64,9 @@ struct watchdog_ops { >> * @timeout: The watchdog devices timeout value. >> * @min_timeout:The watchdog devices minimum timeout value. >> * @max_timeout:The watchdog devices maximum timeout value. >> + * @pretimeout: The watchdog devices pretimeout value. >> + * @min_pretimeout:The watchdog devices minimum pretimeout value. >> + * @max_pretimeout:The watchdog devices maximum pretimeout value. >> * @driver-data:Pointer to the drivers private data. >> * @lock: Lock for watchdog core internal use only. >> * @status: Field that contains the devices internal status bits. >> @@ -86,6 +91,9 @@ struct watchdog_device { >> unsigned int timeout; >> unsigned int min_timeout; >> unsigned int max_timeout; >> + unsigned int pretimeout; >> + unsigned int min_pretimeout; >> + unsigned int max_pretimeout; >> void *driver_data; >> struct mutex lock; >> unsigned long status; >> @@ -117,7 +125,17 @@ static inline void watchdog_set_nowayout(struct >> watchdog_device *wdd, bool noway >> static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, >> unsigned int t) >> { >> return ((wdd->max_timeout != 0) && >> - (t < wdd->min_timeout || t > wdd->max_timeout)); >> + (t < wdd->min_timeout || t > wdd->max_timeout || >> + t <= wdd->pretimeout)); >> +} >> + >> +/* 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 (wdd->max_pretimeout != 0 && >> + (t < wdd->min_pretimeout || t > wdd->max_pretimeout || >> + (wdd->timeout != 0 && t >= wdd->timeout))); > > > This validates a pretimeout as valid if max_pretimeout == 0, > no matter what timeout is set to. > > Do we really need to check if timeout == 0 ? Can that ever happen ? (wdd->timeout != 0 && t >= wdd->timeout) if we have set timeout(wdd->timeout != 0), and t(pretimeout) > wdd->timeout, t is a invalid value. Am I correct? the reason of adding "wdd->timeout != 0": if driver calls this function before setting up wdd->timeout. > >> } >> >> /* Use the following functions to manipulate watchdog driver specific >> data */ >> @@ -132,11 +150,20 @@ static inline void *watchdog_get_drvdata(struct >> watchdog_device *wdd) >> } >> >> /* drivers/watchdog/watchdog_core.c */ >> -extern int watchdog_init_timeout(struct watchdog_device *wdd, >> - unsigned int timeout_parm, struct device >> *dev); >> +extern int watchdog_init_timeouts(struct watchdog_device *wdd, >> + unsigned int pretimeout_parm, >> + unsigned int timeout_parm, >> + struct device *dev); > > > No 'extern' here, please. Yes, we'll need to fix that for the other > function declarations, but that is not a reason to introduce new ones. OK, I do agree with you on this, have fixed it in my next patchset. > > Thanks, > Guenter >
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index a0438f3..95b355d 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -49,6 +49,9 @@ struct watchdog_device { unsigned int timeout; unsigned int min_timeout; unsigned int max_timeout; + unsigned int pretimeout; + unsigned int min_pretimeout; + unsigned int max_pretimeout; void *driver_data; struct mutex lock; unsigned long status; @@ -70,6 +73,9 @@ It contains following fields: * timeout: the watchdog timer's timeout value (in seconds). * min_timeout: the watchdog timer's minimum timeout value (in seconds). * max_timeout: the watchdog timer's maximum timeout value (in seconds). +* pretimeout: the watchdog timer's pretimeout value (in seconds). +* min_pretimeout: the watchdog timer's minimum pretimeout value (in seconds). +* max_pretimeout: the watchdog timer's maximum pretimeout value (in seconds). * bootstatus: status of the device after booting (reported with watchdog WDIOF_* status bits). * driver_data: a pointer to the drivers private data of a watchdog device. @@ -92,6 +98,7 @@ 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 *); void (*ref)(struct watchdog_device *); void (*unref)(struct watchdog_device *); @@ -153,9 +160,19 @@ they are supported. These optional routines/operations are: and -EIO for "could not write value to the watchdog". On success this routine should set the timeout value of the watchdog_device to the achieved timeout value (which may be different from the requested one - because the watchdog does not necessarily has a 1 second resolution). + because the watchdog does not necessarily has a 1 second resolution; + If the driver supports pretimeout, then the timeout value must be greater + than that). (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the watchdog's info structure). +* set_pretimeout: this routine checks and changes the pretimeout of the + watchdog timer device. It returns 0 on success, -EINVAL for "parameter out of + range" and -EIO for "could not write value to the watchdog". On success this + routine should set the pretimeout value of the watchdog_device to the + achieved pretimeout value (which may be different from the requested one + because the watchdog does not necessarily has a 1 second resolution). + (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the + watchdog's info structure). * get_timeleft: this routines returns the time that's left before a reset. * ref: the operation that calls kref_get on the kref of a dynamically allocated watchdog_device struct. @@ -219,8 +236,28 @@ extern int watchdog_init_timeout(struct watchdog_device *wdd, unsigned int timeout_parm, struct device *dev); The watchdog_init_timeout function allows you to initialize the timeout field -using the module timeout parameter or by retrieving the timeout-sec property from -the device tree (if the module timeout parameter is invalid). Best practice is -to set the default timeout value as timeout value in the watchdog_device and -then use this function to set the user "preferred" timeout value. +using the module timeout parameter or by retrieving the first element of +the timeout-sec property from the device tree (if the module timeout parameter +is invalid). Best practice is to set the default timeout value as timeout value +in the watchdog_device and then use this function to set the user "preferred" +timeout value. +This routine returns zero on success and a negative errno code for failure. + +Some watchdog timers have two stage of timeouts(timeout and pretimeout), +to initialize the timeout and pretimeout fields at the same time, the following +function can be used: + +extern int watchdog_init_timeouts(struct watchdog_device *wdd, + unsigned int pretimeout_parm, + unsigned int timeout_parm, + struct device *dev); + +The watchdog_init_timeouts function allows you to initialize the pretimeout and +timeout fields using the module pretimeout and timeout parameter or by +retrieving the elements in the timeout-sec property(the first element is for +timeout, the second one is for pretimeout) from the device tree(if the module +pretimeout and timeout parameter are invalid). +Best practice is to set the default pretimeout and timeout value as pretimeout +and timeout value in the watchdog_device and then use this function to set the +user "preferred" pretimeout value. This routine returns zero on success and a negative errno code for failure. diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index cec9b55..ff18db3 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -43,60 +43,119 @@ static DEFINE_IDA(watchdog_ida); static struct class *watchdog_class; -static void watchdog_check_min_max_timeout(struct watchdog_device *wdd) +static void watchdog_check_min_max_timeouts(struct watchdog_device *wdd) { /* - * Check that we have valid min and max timeout values, if - * not reset them both to 0 (=not used or unknown) + * Check that we have valid min and max pretimeout and timeout values, + * if not reset them both to 0 (=not used or unknown) */ + if (wdd->min_pretimeout > wdd->max_pretimeout) { + pr_info("Invalid min and max pretimeout, resetting to 0\n"); + wdd->min_pretimeout = 0; + wdd->max_pretimeout = 0; + } if (wdd->min_timeout > wdd->max_timeout) { pr_info("Invalid min and max timeout values, resetting to 0!\n"); wdd->min_timeout = 0; wdd->max_timeout = 0; } + /* + * Check that we have valid min timeout and max pretimeout values, + * if not reset them. + */ + if (wdd->min_pretimeout && wdd->min_timeout < wdd->min_pretimeout) { + pr_info("Invalid min_timeout, resetting to min_pretimeout+1\n"); + wdd->min_timeout = wdd->min_pretimeout + 1; + } + if (wdd->max_pretimeout && wdd->max_timeout < wdd->max_pretimeout) { + pr_info("Invalid max_pretimeout, resetting to max_timeout-1\n"); + wdd->max_pretimeout = wdd->max_timeout - 1; + } } /** - * watchdog_init_timeout() - initialize the timeout field + * watchdog_init_timeouts() - initialize the pretimeout and timeout field + * @pretimeout_parm: pretimeout module parameter * @timeout_parm: timeout module parameter * @dev: Device that stores the timeout-sec property * - * Initialize the timeout field of the watchdog_device struct with either the - * timeout module parameter (if it is valid value) or the timeout-sec property - * (only if it is a valid value and the timeout_parm is out of bounds). - * If none of them are valid then we keep the old value (which should normally - * be the default timeout value. + * Initialize the pretimeout and timeout field of the watchdog_device struct + * with either the pretimeout and timeout module parameter (if it is valid + * value) or the timeout-sec property (only if it is a valid value and the + * pretimeout_parm and timeout_parm is out of bounds). If none of them are + * valid, then we keep the old value (which should normally be the default + * timeout value). * * A zero is returned on success and -EINVAL for failure. */ -int watchdog_init_timeout(struct watchdog_device *wdd, - unsigned int timeout_parm, struct device *dev) +int watchdog_init_timeouts(struct watchdog_device *wdd, + unsigned int pretimeout_parm, + unsigned int timeout_parm, + struct device *dev) { - unsigned int t = 0; - int ret = 0; + int ret = 0, length = 0; + u32 timeouts[2] = {0}; - watchdog_check_min_max_timeout(wdd); + watchdog_check_min_max_timeouts(wdd); - /* try to get the timeout module parameter first */ - if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) { - wdd->timeout = timeout_parm; - return ret; + /* + * Try to get the pretimeout module parameter first, + * but it can be "0", that means we don't use pretimeout. + */ + if (pretimeout_parm) { + if (!watchdog_pretimeout_invalid(wdd, pretimeout_parm)) + timeouts[1] = pretimeout_parm; + ret = -EINVAL; /* pretimeout_parm is not "0", and invalid */ } - if (timeout_parm) + + /* + * Try to get the timeout module parameter, + * if it's valid and pretimeout is ont invalid(ret == 0), + * assignment and return zero. Otherwise, try dtb. + */ + if (timeout_parm) { + if (!watchdog_timeout_invalid(wdd, timeout_parm) && !ret) { + wdd->timeout = timeout_parm; + wdd->pretimeout = timeouts[1]; + return 0; + } ret = -EINVAL; + } - /* try to get the timeout_sec property */ + /* + * We get here, the situation is one of them: + * (1)at least one of parameters is invalid(ret = -EINVAL); + * (2)both of them are 0.(ret = 0) + * So give up the module parameter(at least drop the invalid one), + * try to get the timeout_sec property from dtb. + */ if (dev == NULL || dev->of_node == NULL) return ret; - of_property_read_u32(dev->of_node, "timeout-sec", &t); - if (!watchdog_timeout_invalid(wdd, t) && t) - wdd->timeout = t; - else - ret = -EINVAL; - return ret; + /* + * We get here, that means maybe we can get timeouts from dtb, + * if "timeout-sec" is available and the data is valid. + */ + of_find_property(dev->of_node, "timeout-sec", &length); + if (length > 0 && length <= sizeof(u32) * 2) { + of_property_read_u32_array(dev->of_node, + "timeout-sec", timeouts, + length / sizeof(u32)); + if (length == sizeof(u32) * 2 && timeouts[1] && + watchdog_pretimeout_invalid(wdd, timeouts[1])) + return -EINVAL; /* pretimeout is invalid */ + + if (!watchdog_timeout_invalid(wdd, timeouts[0]) && + timeouts[0]) { + wdd->timeout = timeouts[0]; + wdd->pretimeout = timeouts[1]; + return 0; + } + } + + return -EINVAL; } -EXPORT_SYMBOL_GPL(watchdog_init_timeout); +EXPORT_SYMBOL_GPL(watchdog_init_timeouts); /** * watchdog_register_device() - register a watchdog device @@ -119,7 +178,7 @@ int watchdog_register_device(struct watchdog_device *wdd) if (wdd->ops->start == NULL || wdd->ops->stop == NULL) return -EINVAL; - watchdog_check_min_max_timeout(wdd); + watchdog_check_min_max_timeouts(wdd); /* * Note: now that all watchdog_device data has been verified, we diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 6aaefba..af0777e 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -218,6 +218,38 @@ out_timeout: } /* + * watchdog_set_pretimeout: set the watchdog timer pretimeout + * @wddev: the watchdog device to set the timeout for + * @pretimeout: pretimeout to set in seconds + */ + +static int watchdog_set_pretimeout(struct watchdog_device *wddev, + unsigned int pretimeout) +{ + int err; + + if (!wddev->ops->set_pretimeout || + !(wddev->info->options & WDIOF_PRETIMEOUT)) + return -EOPNOTSUPP; + + if (watchdog_pretimeout_invalid(wddev, pretimeout)) + return -EINVAL; + + mutex_lock(&wddev->lock); + + if (test_bit(WDOG_UNREGISTERED, &wddev->status)) { + err = -ENODEV; + goto out_pretimeout; + } + + err = wddev->ops->set_pretimeout(wddev, pretimeout); + +out_pretimeout: + mutex_unlock(&wddev->lock); + return err; +} + +/* * watchdog_get_timeleft: wrapper to get the time left before a reboot * @wddev: the watchdog device to get the remaining time from * @timeleft: the time that's left @@ -388,6 +420,27 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, if (wdd->timeout == 0) return -EOPNOTSUPP; return put_user(wdd->timeout, p); + case WDIOC_SETPRETIMEOUT: + /* check if we support the pretimeout */ + if (!(wdd->info->options & WDIOF_PRETIMEOUT)) + return -EOPNOTSUPP; + if (get_user(val, p)) + return -EFAULT; + err = watchdog_set_pretimeout(wdd, val); + if (err < 0) + return err; + /* + * If the watchdog is active then we send a keepalive ping + * to make sure that the watchdog keeps running (and if + * possible that it takes the new pretimeout) + */ + watchdog_ping(wdd); + /* Fall */ + case WDIOC_GETPRETIMEOUT: + /* check if we support the pretimeout */ + if (wdd->info->options & WDIOF_PRETIMEOUT) + return put_user(wdd->pretimeout, p); + return -EOPNOTSUPP; case WDIOC_GETTIMELEFT: err = watchdog_get_timeleft(wdd, &val); if (err) diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h index a746bf5..b1e325d 100644 --- a/include/linux/watchdog.h +++ b/include/linux/watchdog.h @@ -25,6 +25,7 @@ struct watchdog_device; * @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. + * @set_pretimeout:The routine for setting the watchdog devices pretimeout value * @get_timeleft:The routine that get's the time that's left before a reset. * @ref: The ref operation for dyn. allocated watchdog_device structs * @unref: The unref operation for dyn. allocated watchdog_device structs @@ -44,6 +45,7 @@ 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 *); void (*ref)(struct watchdog_device *); void (*unref)(struct watchdog_device *); @@ -62,6 +64,9 @@ struct watchdog_ops { * @timeout: The watchdog devices timeout value. * @min_timeout:The watchdog devices minimum timeout value. * @max_timeout:The watchdog devices maximum timeout value. + * @pretimeout: The watchdog devices pretimeout value. + * @min_pretimeout:The watchdog devices minimum pretimeout value. + * @max_pretimeout:The watchdog devices maximum pretimeout value. * @driver-data:Pointer to the drivers private data. * @lock: Lock for watchdog core internal use only. * @status: Field that contains the devices internal status bits. @@ -86,6 +91,9 @@ struct watchdog_device { unsigned int timeout; unsigned int min_timeout; unsigned int max_timeout; + unsigned int pretimeout; + unsigned int min_pretimeout; + unsigned int max_pretimeout; void *driver_data; struct mutex lock; unsigned long status; @@ -117,7 +125,17 @@ static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool noway static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t) { return ((wdd->max_timeout != 0) && - (t < wdd->min_timeout || t > wdd->max_timeout)); + (t < wdd->min_timeout || t > wdd->max_timeout || + t <= wdd->pretimeout)); +} + +/* 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 (wdd->max_pretimeout != 0 && + (t < wdd->min_pretimeout || t > wdd->max_pretimeout || + (wdd->timeout != 0 && t >= wdd->timeout))); } /* Use the following functions to manipulate watchdog driver specific data */ @@ -132,11 +150,20 @@ static inline void *watchdog_get_drvdata(struct watchdog_device *wdd) } /* drivers/watchdog/watchdog_core.c */ -extern int watchdog_init_timeout(struct watchdog_device *wdd, - unsigned int timeout_parm, struct device *dev); +extern int watchdog_init_timeouts(struct watchdog_device *wdd, + unsigned int pretimeout_parm, + unsigned int timeout_parm, + struct device *dev); extern int watchdog_register_device(struct watchdog_device *); extern void watchdog_unregister_device(struct watchdog_device *); +static inline int watchdog_init_timeout(struct watchdog_device *wdd, + unsigned int timeout_parm, + struct device *dev) +{ + return watchdog_init_timeouts(wdd, 0, timeout_parm, dev); +} + #ifdef CONFIG_HARDLOCKUP_DETECTOR void watchdog_nmi_disable_all(void); void watchdog_nmi_enable_all(void);