watchdog: add pretimeout support to the core

Since the watchdog framework centrializes the IOCTL interfaces of device
drivers now, SETPRETIMEOUT and GETPRETIMEOUT need to be added in the
common code.

Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[vzapolskiy: added conditional pretimeout sysfs attribute visibility]
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Wolfram Sang 2016-08-31 14:52:41 +03:00 committed by Wim Van Sebroeck
parent 68d4cb809e
commit df044e0220
3 changed files with 85 additions and 2 deletions

View File

@ -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.

View File

@ -335,16 +335,45 @@ 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);
return err;
}
/*
* 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
@ -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;

View File

@ -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)
{