+enum cmm_memorder {
+ CMM_RELAXED = 0,
+ CMM_CONSUME = 1,
+ CMM_ACQUIRE = 2,
+ CMM_RELEASE = 3,
+ CMM_ACQ_REL = 4,
+ CMM_SEQ_CST = 5,
+ CMM_SEQ_CST_FENCE = 6,
+};
+
+#ifdef CONFIG_RCU_USE_ATOMIC_BUILTINS
+
+/*
+ * Make sure that CMM_SEQ_CST_FENCE is not equivalent to other memory orders.
+ */
+urcu_static_assert(CMM_RELAXED == __ATOMIC_RELAXED, "CMM_RELAXED vs __ATOMIC_RELAXED values mismatch", cmm_relaxed_values_mismatch);
+urcu_static_assert(CMM_CONSUME == __ATOMIC_CONSUME, "CMM_CONSUME vs __ATOMIC_CONSUME values mismatch", cmm_consume_values_mismatch);
+urcu_static_assert(CMM_ACQUIRE == __ATOMIC_ACQUIRE, "CMM_ACQUIRE vs __ATOMIC_ACQUIRE values mismatch", cmm_acquire_values_mismatch);
+urcu_static_assert(CMM_RELEASE == __ATOMIC_RELEASE, "CMM_RELEASE vs __ATOMIC_RELEASE values mismatch", cmm_release_values_mismatch);
+urcu_static_assert(CMM_ACQ_REL == __ATOMIC_ACQ_REL, "CMM_ACQ_REL vs __ATOMIC_ACQ_REL values mismatch", cmm_acq_rel_values_mismatch);
+urcu_static_assert(CMM_SEQ_CST == __ATOMIC_SEQ_CST, "CMM_SEQ_CST vs __ATOMIC_SEQ_CST values mismatch", cmm_seq_cst_values_mismatch);
+
+/*
+ * This is not part of the public API. It it used internally to implement the
+ * CMM_SEQ_CST_FENCE memory order.
+ *
+ * NOTE: Using switch here instead of if statement to avoid -Wduplicated-cond
+ * warning when memory order is conditionally determined.
+ */
+static inline void cmm_seq_cst_fence_after_atomic(enum cmm_memorder mo)
+{
+ switch (mo) {
+ case CMM_SEQ_CST_FENCE:
+ cmm_smp_mb();
+ break;
+ default:
+ break;
+ }
+}
+
+#endif
+
+/*
+ * This is not part of the public API. It is used internally to convert from the
+ * CMM memory model to the C11 memory model.
+ */
+static inline int cmm_to_c11(int mo)
+{
+ if (mo == CMM_SEQ_CST_FENCE) {
+ return CMM_SEQ_CST;
+ }
+ return mo;
+}
+
+#if defined(CONFIG_RCU_USE_ATOMIC_BUILTINS)
+#include <urcu/uatomic/builtins.h>
+#elif defined(URCU_ARCH_X86)