Exposes device_is_ancestor() API which can be used
for check the device is the target device's ancestor or not.
Signed-off-by: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/base/core.c | 3 ++-
include/linux/device.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index a3e14143ec0c..597192b38198 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -262,7 +262,7 @@ static void device_link_remove_from_lists(struct device_link *link)
}
#endif /* !CONFIG_SRCU */
-static bool device_is_ancestor(struct device *dev, struct device *target)
+bool device_is_ancestor(struct device *dev, struct device *target)
{
while (target->parent) {
target = target->parent;
@@ -271,6 +271,7 @@ static bool device_is_ancestor(struct device *dev, struct device *target)
}
return false;
}
+EXPORT_SYMBOL_GPL(device_is_ancestor);
/**
* device_is_dependent - Check if one device depends on another one
diff --git a/include/linux/device.h b/include/linux/device.h
index 44e3acae7b36..35e35982d9a5 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -909,6 +909,7 @@ int device_move(struct device *dev, struct device *new_parent,
int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
const char *device_get_devnode(struct device *dev, umode_t *mode, kuid_t *uid,
kgid_t *gid, const char **tmp);
+bool device_is_ancestor(struct device *dev, struct device *target);
int device_is_dependent(struct device *dev, void *target);
static inline bool device_supports_offline(struct device *dev)
--
2.38.1
