backports: Add smp_acquire__after_ctrl_dep()
smp_acquire__after_ctrl_dep() was introduced in kernel 4.8 in upstream
Linux commit 33ac279677d ("locking/barriers: Introduce
smp_acquire__after_ctrl_dep()") and is used by backports lib-refcount.c
implementation now.
This just adds the default implementation to backports.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
diff --git a/backport/backport-include/asm/barrier.h b/backport/backport-include/asm/barrier.h
index 9e1e1f1..bca0558 100644
--- a/backport/backport-include/asm/barrier.h
+++ b/backport/backport-include/asm/barrier.h
@@ -19,4 +19,8 @@
#define smp_mb__after_atomic smp_mb__after_clear_bit
#endif
+#ifndef smp_acquire__after_ctrl_dep
+#define smp_acquire__after_ctrl_dep() smp_rmb()
+#endif
+
#endif /* __BACKPORT_ASM_BARRIER_H */
