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

From: Michael Auchter
Date: Wed Oct 14 2020 - 15:36:50 EST


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

Signed-off-by: Michael Auchter <michael.auchter@xxxxxx>
---
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