1 files changed, 14 insertions, 0 deletions

diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 5cdd8065a3ce..4b082b5cac9e 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -34,6 +34,20 @@
 #else
 #define raw_read_can_lock(l)    read_can_lock(l)
 #define raw_write_can_lock(l)   write_can_lock(l)
+
+/*
+ * Some architectures can relax in favour of the CPU owning the lock.
+ */
+#ifndef arch_read_relax
+# define arch_read_relax(l)     cpu_relax()
+#endif
+#ifndef arch_write_relax
+# define arch_write_relax(l)    cpu_relax()
+#endif
+#ifndef arch_spin_relax
+# define arch_spin_relax(l)     cpu_relax()
+#endif
+
 /*
  * We build the __lock_function inlines here. They are too large for
  * inlining all over the place, but here is only one user per function