1 files changed, 90 insertions, 0 deletions
diff --git a/lib/librte_eal/common/include/generic/rte_atomic.h b/lib/librte_eal/common/include/generic/rte_atomic.h
index 50e1b8a4..b99ba468 100644
--- a/lib/librte_eal/common/include/generic/rte_atomic.h
+++ b/lib/librte_eal/common/include/generic/rte_atomic.h
@@ -191,6 +191,36 @@ rte_atomic16_cmpset(volatile uint16_t *dst, uint16_t exp, uint16_t src)
 #endif
 
 /**
+ * Atomic exchange.
+ *
+ * (atomic) equivalent to:
+ *   ret = *dst
+ *   *dst = val;
+ *   return ret;
+ *
+ * @param dst
+ *   The destination location into which the value will be written.
+ * @param val
+ *   The new value.
+ * @return
+ *   The original value at that location
+ */
+static inline uint16_t
+rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline uint16_t
+rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val)
+{
+#if defined(RTE_ARCH_ARM64) && defined(RTE_TOOLCHAIN_CLANG)
+	return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);
+#else
+	return __atomic_exchange_2(dst, val, __ATOMIC_SEQ_CST);
+#endif
+}
+#endif
+
+/**
  * The atomic counter structure.
  */
 typedef struct {
@@ -444,6 +474,36 @@ rte_atomic32_cmpset(volatile uint32_t *dst, uint32_t exp, uint32_t src)
 #endif
 
 /**
+ * Atomic exchange.
+ *
+ * (atomic) equivalent to:
+ *   ret = *dst
+ *   *dst = val;
+ *   return ret;
+ *
+ * @param dst
+ *   The destination location into which the value will be written.
+ * @param val
+ *   The new value.
+ * @return
+ *   The original value at that location
+ */
+static inline uint32_t
+rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline uint32_t
+rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val)
+{
+#if defined(RTE_ARCH_ARM64) && defined(RTE_TOOLCHAIN_CLANG)
+	return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);
+#else
+	return __atomic_exchange_4(dst, val, __ATOMIC_SEQ_CST);
+#endif
+}
+#endif
+
+/**
  * The atomic counter structure.
  */
 typedef struct {
@@ -696,6 +756,36 @@ rte_atomic64_cmpset(volatile uint64_t *dst, uint64_t exp, uint64_t src)
 #endif
 
 /**
+ * Atomic exchange.
+ *
+ * (atomic) equivalent to:
+ *   ret = *dst
+ *   *dst = val;
+ *   return ret;
+ *
+ * @param dst
+ *   The destination location into which the value will be written.
+ * @param val
+ *   The new value.
+ * @return
+ *   The original value at that location
+ */
+static inline uint64_t
+rte_atomic64_exchange(volatile uint64_t *dst, uint64_t val);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline uint64_t
+rte_atomic64_exchange(volatile uint64_t *dst, uint64_t val)
+{
+#if defined(RTE_ARCH_ARM64) && defined(RTE_TOOLCHAIN_CLANG)
+	return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);
+#else
+	return __atomic_exchange_8(dst, val, __ATOMIC_SEQ_CST);
+#endif
+}
+#endif
+
+/**
  * The atomic counter structure.
  */
 typedef struct {