2005-04-17 06:20:36 +08:00
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/*
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* Generic watchdog defines. Derived from..
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*
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* Berkshire PC Watchdog Defines
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* by Ken Hollis <khollis@bitgate.com>
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*
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*/
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#ifndef _LINUX_WATCHDOG_H
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#define _LINUX_WATCHDOG_H
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2005-07-28 02:43:58 +08:00
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2011-11-29 23:24:16 +08:00
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#include <linux/bitops.h>
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2012-05-11 03:48:59 +08:00
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#include <linux/cdev.h>
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2016-02-29 05:12:15 +08:00
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#include <linux/device.h>
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#include <linux/kernel.h>
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2015-11-17 01:27:59 +08:00
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#include <linux/notifier.h>
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2012-10-13 17:46:48 +08:00
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#include <uapi/linux/watchdog.h>
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2005-07-28 02:43:58 +08:00
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2011-07-23 02:55:18 +08:00
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struct watchdog_ops;
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struct watchdog_device;
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watchdog: Separate and maintain variables based on variable lifetime
All variables required by the watchdog core to manage a watchdog are
currently stored in struct watchdog_device. The lifetime of those
variables is determined by the watchdog driver. However, the lifetime
of variables used by the watchdog core differs from the lifetime of
struct watchdog_device. To remedy this situation, watchdog drivers
can implement ref and unref callbacks, to be used by the watchdog
core to lock struct watchdog_device in memory.
While this solves the immediate problem, it depends on watchdog drivers
to actually implement the ref/unref callbacks. This is error prone,
often not implemented in the first place, or not implemented correctly.
To solve the problem without requiring driver support, split the variables
in struct watchdog_device into two data structures - one for variables
associated with the watchdog driver, one for variables associated with
the watchdog core. With this approach, the watchdog core can keep track
of its variable lifetime and no longer depends on ref/unref callbacks
in the driver. As a side effect, some of the variables originally in
struct watchdog_driver are now private to the watchdog core and no longer
visible in watchdog drivers.
As a side effect of the changes made, an ioctl will now always fail
with -ENODEV after a watchdog device was unregistered with the character
device still open. Previously, it would only fail with -ENODEV in some
situations. Also, ioctl operations are now atomic from driver perspective.
With this change, it is now guaranteed that the driver will not unregister
a watchdog between a timeout change and the subsequent ping.
The 'ref' and 'unref' callbacks in struct watchdog_driver are no longer
used and marked as deprecated.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-26 08:01:42 +08:00
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struct watchdog_core_data;
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2011-07-23 02:55:18 +08:00
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/** struct watchdog_ops - The watchdog-devices operations
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*
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* @owner: The module owner.
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* @start: The routine for starting the watchdog device.
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* @stop: The routine for stopping the watchdog device.
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* @ping: The routine that sends a keepalive ping to the watchdog device.
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2011-07-23 02:56:38 +08:00
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* @status: The routine that shows the status of the watchdog device.
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2015-11-03 16:00:16 +08:00
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* @set_timeout:The routine for setting the watchdog devices timeout value (in seconds).
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* @get_timeleft:The routine that gets the time left before a reset (in seconds).
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2015-11-17 01:27:59 +08:00
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* @restart: The routine for restarting the machine.
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2011-07-23 02:59:49 +08:00
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* @ioctl: The routines that handles extra ioctl calls.
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2011-07-23 02:55:18 +08:00
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*
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* The watchdog_ops structure contains a list of low-level operations
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* that control a watchdog device. It also contains the module that owns
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* these operations. The start and stop function are mandatory, all other
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2015-11-03 16:00:15 +08:00
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* functions are optional.
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2011-07-23 02:55:18 +08:00
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*/
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struct watchdog_ops {
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struct module *owner;
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/* mandatory operations */
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int (*start)(struct watchdog_device *);
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int (*stop)(struct watchdog_device *);
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/* optional operations */
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int (*ping)(struct watchdog_device *);
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2011-07-23 02:56:38 +08:00
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unsigned int (*status)(struct watchdog_device *);
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2011-07-23 02:58:21 +08:00
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int (*set_timeout)(struct watchdog_device *, unsigned int);
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2012-03-16 16:14:00 +08:00
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unsigned int (*get_timeleft)(struct watchdog_device *);
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2016-02-27 09:32:49 +08:00
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int (*restart)(struct watchdog_device *, unsigned long, void *);
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2011-07-23 02:59:49 +08:00
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long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
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2011-07-23 02:55:18 +08:00
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};
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/** struct watchdog_device - The structure that defines a watchdog device
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*
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2012-05-11 03:48:59 +08:00
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* @id: The watchdog's ID. (Allocated by watchdog_register_device)
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2012-05-11 18:00:20 +08:00
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* @parent: The parent bus device
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2016-01-04 07:11:56 +08:00
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* @groups: List of sysfs attribute groups to create when creating the
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* watchdog device.
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2011-07-23 02:55:18 +08:00
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* @info: Pointer to a watchdog_info structure.
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* @ops: Pointer to the list of watchdog operations.
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2011-07-23 02:56:38 +08:00
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* @bootstatus: Status of the watchdog device at boot.
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2015-11-03 16:00:16 +08:00
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* @timeout: The watchdog devices timeout value (in seconds).
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* @min_timeout:The watchdog devices minimum timeout value (in seconds).
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2016-02-29 05:12:15 +08:00
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* @max_timeout:The watchdog devices maximum timeout value (in seconds)
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* as configurable from user space. Only relevant if
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* max_hw_heartbeat_ms is not provided.
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2016-02-29 05:12:18 +08:00
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* @min_hw_heartbeat_ms:
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2016-05-28 05:19:06 +08:00
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* Hardware limit for minimum time between heartbeats,
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* in milli-seconds.
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2016-02-29 05:12:15 +08:00
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* @max_hw_heartbeat_ms:
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* Hardware limit for maximum timeout, in milli-seconds.
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* Replaces max_timeout if specified.
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2015-11-21 05:54:51 +08:00
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* @reboot_nb: The notifier block to stop watchdog on reboot.
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2015-11-17 01:27:59 +08:00
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* @restart_nb: The notifier block to register a restart function.
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watchdog: Separate and maintain variables based on variable lifetime
All variables required by the watchdog core to manage a watchdog are
currently stored in struct watchdog_device. The lifetime of those
variables is determined by the watchdog driver. However, the lifetime
of variables used by the watchdog core differs from the lifetime of
struct watchdog_device. To remedy this situation, watchdog drivers
can implement ref and unref callbacks, to be used by the watchdog
core to lock struct watchdog_device in memory.
While this solves the immediate problem, it depends on watchdog drivers
to actually implement the ref/unref callbacks. This is error prone,
often not implemented in the first place, or not implemented correctly.
To solve the problem without requiring driver support, split the variables
in struct watchdog_device into two data structures - one for variables
associated with the watchdog driver, one for variables associated with
the watchdog core. With this approach, the watchdog core can keep track
of its variable lifetime and no longer depends on ref/unref callbacks
in the driver. As a side effect, some of the variables originally in
struct watchdog_driver are now private to the watchdog core and no longer
visible in watchdog drivers.
As a side effect of the changes made, an ioctl will now always fail
with -ENODEV after a watchdog device was unregistered with the character
device still open. Previously, it would only fail with -ENODEV in some
situations. Also, ioctl operations are now atomic from driver perspective.
With this change, it is now guaranteed that the driver will not unregister
a watchdog between a timeout change and the subsequent ping.
The 'ref' and 'unref' callbacks in struct watchdog_driver are no longer
used and marked as deprecated.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-26 08:01:42 +08:00
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* @driver_data:Pointer to the drivers private data.
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* @wd_data: Pointer to watchdog core internal data.
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2011-07-23 02:55:18 +08:00
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* @status: Field that contains the devices internal status bits.
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2016-02-29 05:12:15 +08:00
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* @deferred: Entry in wtd_deferred_reg_list which is used to
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* register early initialized watchdogs.
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2011-07-23 02:55:18 +08:00
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*
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* The watchdog_device structure contains all information about a
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* watchdog timer device.
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*
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* The driver-data field may not be accessed directly. It must be accessed
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* via the watchdog_set_drvdata and watchdog_get_drvdata helpers.
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2012-05-22 17:40:26 +08:00
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*
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* The lock field is for watchdog core internal use only and should not be
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* touched.
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2011-07-23 02:55:18 +08:00
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*/
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struct watchdog_device {
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2012-05-11 03:48:59 +08:00
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int id;
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2012-05-11 18:00:20 +08:00
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struct device *parent;
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2016-01-04 07:11:56 +08:00
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const struct attribute_group **groups;
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2011-07-23 02:55:18 +08:00
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const struct watchdog_info *info;
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const struct watchdog_ops *ops;
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2011-07-23 02:56:38 +08:00
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unsigned int bootstatus;
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2011-07-23 02:58:21 +08:00
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unsigned int timeout;
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2011-07-23 03:00:16 +08:00
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unsigned int min_timeout;
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unsigned int max_timeout;
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2016-02-29 05:12:18 +08:00
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unsigned int min_hw_heartbeat_ms;
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2016-02-29 05:12:15 +08:00
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unsigned int max_hw_heartbeat_ms;
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2015-11-21 05:54:51 +08:00
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struct notifier_block reboot_nb;
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2015-11-17 01:27:59 +08:00
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struct notifier_block restart_nb;
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2011-07-23 02:55:18 +08:00
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void *driver_data;
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watchdog: Separate and maintain variables based on variable lifetime
All variables required by the watchdog core to manage a watchdog are
currently stored in struct watchdog_device. The lifetime of those
variables is determined by the watchdog driver. However, the lifetime
of variables used by the watchdog core differs from the lifetime of
struct watchdog_device. To remedy this situation, watchdog drivers
can implement ref and unref callbacks, to be used by the watchdog
core to lock struct watchdog_device in memory.
While this solves the immediate problem, it depends on watchdog drivers
to actually implement the ref/unref callbacks. This is error prone,
often not implemented in the first place, or not implemented correctly.
To solve the problem without requiring driver support, split the variables
in struct watchdog_device into two data structures - one for variables
associated with the watchdog driver, one for variables associated with
the watchdog core. With this approach, the watchdog core can keep track
of its variable lifetime and no longer depends on ref/unref callbacks
in the driver. As a side effect, some of the variables originally in
struct watchdog_driver are now private to the watchdog core and no longer
visible in watchdog drivers.
As a side effect of the changes made, an ioctl will now always fail
with -ENODEV after a watchdog device was unregistered with the character
device still open. Previously, it would only fail with -ENODEV in some
situations. Also, ioctl operations are now atomic from driver perspective.
With this change, it is now guaranteed that the driver will not unregister
a watchdog between a timeout change and the subsequent ping.
The 'ref' and 'unref' callbacks in struct watchdog_driver are no longer
used and marked as deprecated.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-26 08:01:42 +08:00
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struct watchdog_core_data *wd_data;
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2011-07-23 02:55:18 +08:00
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unsigned long status;
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/* Bit numbers for status flags */
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2011-07-23 02:57:55 +08:00
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#define WDOG_ACTIVE 0 /* Is the watchdog running/active */
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watchdog: Separate and maintain variables based on variable lifetime
All variables required by the watchdog core to manage a watchdog are
currently stored in struct watchdog_device. The lifetime of those
variables is determined by the watchdog driver. However, the lifetime
of variables used by the watchdog core differs from the lifetime of
struct watchdog_device. To remedy this situation, watchdog drivers
can implement ref and unref callbacks, to be used by the watchdog
core to lock struct watchdog_device in memory.
While this solves the immediate problem, it depends on watchdog drivers
to actually implement the ref/unref callbacks. This is error prone,
often not implemented in the first place, or not implemented correctly.
To solve the problem without requiring driver support, split the variables
in struct watchdog_device into two data structures - one for variables
associated with the watchdog driver, one for variables associated with
the watchdog core. With this approach, the watchdog core can keep track
of its variable lifetime and no longer depends on ref/unref callbacks
in the driver. As a side effect, some of the variables originally in
struct watchdog_driver are now private to the watchdog core and no longer
visible in watchdog drivers.
As a side effect of the changes made, an ioctl will now always fail
with -ENODEV after a watchdog device was unregistered with the character
device still open. Previously, it would only fail with -ENODEV in some
situations. Also, ioctl operations are now atomic from driver perspective.
With this change, it is now guaranteed that the driver will not unregister
a watchdog between a timeout change and the subsequent ping.
The 'ref' and 'unref' callbacks in struct watchdog_driver are no longer
used and marked as deprecated.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-26 08:01:42 +08:00
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#define WDOG_NO_WAY_OUT 1 /* Is 'nowayout' feature set ? */
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#define WDOG_STOP_ON_REBOOT 2 /* Should be stopped on reboot */
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2016-02-29 05:12:16 +08:00
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#define WDOG_HW_RUNNING 3 /* True if HW watchdog running */
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2015-06-10 00:55:02 +08:00
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struct list_head deferred;
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2011-07-23 02:55:18 +08:00
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};
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2014-09-10 04:18:31 +08:00
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#define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT)
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#define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT)
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2011-11-29 23:24:16 +08:00
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2012-09-20 09:48:00 +08:00
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/* Use the following function to check whether or not the watchdog is active */
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2012-03-12 12:21:56 +08:00
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static inline bool watchdog_active(struct watchdog_device *wdd)
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{
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return test_bit(WDOG_ACTIVE, &wdd->status);
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}
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2016-02-29 05:12:16 +08:00
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/*
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* Use the following function to check whether or not the hardware watchdog
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* is running
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*/
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static inline bool watchdog_hw_running(struct watchdog_device *wdd)
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{
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return test_bit(WDOG_HW_RUNNING, &wdd->status);
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}
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2011-11-29 23:24:16 +08:00
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/* Use the following function to set the nowayout feature */
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2012-03-05 23:51:11 +08:00
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static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
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2011-11-29 23:24:16 +08:00
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{
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if (nowayout)
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set_bit(WDOG_NO_WAY_OUT, &wdd->status);
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}
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2015-11-21 05:54:51 +08:00
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/* Use the following function to stop the watchdog on reboot */
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static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd)
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{
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set_bit(WDOG_STOP_ON_REBOOT, &wdd->status);
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}
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2013-01-08 18:04:10 +08:00
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/* Use the following function to check if a timeout value is invalid */
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static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t)
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{
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2015-09-29 16:27:24 +08:00
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/*
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* The timeout is invalid if
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2016-02-29 05:12:15 +08:00
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* - the requested value is larger than UINT_MAX / 1000
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* (since internal calculations are done in milli-seconds),
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* or
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2015-09-29 16:27:24 +08:00
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* - the requested value is smaller than the configured minimum timeout,
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* or
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2016-02-29 05:12:15 +08:00
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* - a maximum hardware timeout is not configured, a maximum timeout
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* is configured, and the requested value is larger than the
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* configured maximum timeout.
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2015-09-29 16:27:24 +08:00
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*/
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2016-02-29 05:12:15 +08:00
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return t > UINT_MAX / 1000 || t < wdd->min_timeout ||
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(!wdd->max_hw_heartbeat_ms && wdd->max_timeout &&
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t > wdd->max_timeout);
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2013-01-08 18:04:10 +08:00
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}
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2011-07-23 02:55:18 +08:00
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/* Use the following functions to manipulate watchdog driver specific data */
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static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
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{
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wdd->driver_data = data;
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}
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static inline void *watchdog_get_drvdata(struct watchdog_device *wdd)
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{
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return wdd->driver_data;
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}
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2012-10-05 18:16:09 +08:00
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/* drivers/watchdog/watchdog_core.c */
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2015-11-17 01:27:59 +08:00
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void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority);
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2013-01-08 18:04:10 +08:00
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extern int watchdog_init_timeout(struct watchdog_device *wdd,
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unsigned int timeout_parm, struct device *dev);
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2011-07-23 02:55:18 +08:00
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extern int watchdog_register_device(struct watchdog_device *);
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extern void watchdog_unregister_device(struct watchdog_device *);
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2016-05-27 23:33:54 +08:00
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/* devres register variant */
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int devm_watchdog_register_device(struct device *dev, struct watchdog_device *);
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2005-04-17 06:20:36 +08:00
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#endif /* ifndef _LINUX_WATCHDOG_H */
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