eal/x86: add 128-bit atomic compare exchange

[dpdk.git] / lib / librte_eal / common / include / arch / x86 / rte_atomic_64.h

diff --git a/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h b/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
index fd2ec9c..4b83159 100644 (file)
--- a/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
@@ -34,6 +34,7 @@
 /*
  * Inspired from FreeBSD src/sys/amd64/include/atomic.h
  * Copyright (c) 1998 Doug Rabson
+ * Copyright (c) 2019 Intel Corporation
  * All rights reserved.
  */
 
@@ -46,6 +47,7 @@
 
 #include <stdint.h>
 #include <rte_common.h>
+#include <rte_compat.h>
 #include <rte_atomic.h>
 
 /*------------------------- 64 bit atomic operations -------------------------*/
@@ -208,4 +210,49 @@ static inline void rte_atomic64_clear(rte_atomic64_t *v)
 }
 #endif
 
+/*------------------------ 128 bit atomic operations -------------------------*/
+
+/**
+ * 128-bit integer structure.
+ */
+RTE_STD_C11
+typedef struct {
+       RTE_STD_C11
+       union {
+               uint64_t val[2];
+               __int128 int128;
+       };
+} __rte_aligned(16) rte_int128_t;
+
+static inline int __rte_experimental
+rte_atomic128_cmp_exchange(rte_int128_t *dst,
+                          rte_int128_t *exp,
+                          const rte_int128_t *src,
+                          unsigned int weak,
+                          int success,
+                          int failure)
+{
+       RTE_SET_USED(weak);
+       RTE_SET_USED(success);
+       RTE_SET_USED(failure);
+       uint8_t res;
+
+       asm volatile (
+                     MPLOCKED
+                     "cmpxchg16b %[dst];"
+                     " sete %[res]"
+                     : [dst] "=m" (dst->val[0]),
+                       "=a" (exp->val[0]),
+                       "=d" (exp->val[1]),
+                       [res] "=r" (res)
+                     : "b" (src->val[0]),
+                       "c" (src->val[1]),
+                       "a" (exp->val[0]),
+                       "d" (exp->val[1]),
+                       "m" (dst->val[0])
+                     : "memory");
+
+       return res;
+}
+
 #endif /* _RTE_ATOMIC_X86_64_H_ */