[RFC PATCH 2/3] driver core: add device_links_barrier

[Michael Auchter <michael.auchter@ni.com>]

Add a barrier to wait for all device_links SRCU sections to complete.

Signed-off-by: Michael Auchter <michael.auchter@ni.com>
---
 drivers/base/core.c    | 10 ++++++++++
 include/linux/device.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index bb5806a2bd4c..ef4429c4b1f2 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -82,6 +82,11 @@ int device_links_read_lock_held(void)
 {
 	return srcu_read_lock_held(&device_links_srcu);
 }
+
+void device_links_barrier(void)
+{
+	srcu_barrier(&device_links_srcu);
+}
 #else /* !CONFIG_SRCU */
 static DECLARE_RWSEM(device_links_lock);
 
@@ -112,6 +117,11 @@ int device_links_read_lock_held(void)
 	return lockdep_is_held(&device_links_lock);
 }
 #endif
+
+void device_links_barrier(void)
+{
+}
 #endif /* !CONFIG_SRCU */
 
 /**
diff --git a/include/linux/device.h b/include/linux/device.h
index 9e6ea8931a52..8c47e0beb308 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -977,6 +977,7 @@ void device_link_del(struct device_link *link);
 void device_link_remove(void *consumer, struct device *supplier);
 void device_links_supplier_sync_state_pause(void);
 void device_links_supplier_sync_state_resume(void);
+void device_links_barrier(void);
 
 extern __printf(3, 4)
 int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
-- 
2.25.4