X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=lib%2Flibrte_eal%2Fcommon%2Finclude%2Frte_common.h;h=e057f6e2135575b9ebe1785d33f0137ed74c0d54;hb=refs%2Fchanges%2F26%2F6726%2F1;hp=db5ac91c6100fb02ec35145e2cf1cf01ec75dc4d;hpb=ce3d555e43e3795b5d9507fcfc76b7a0a92fd0d6;p=deb_dpdk.git

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index db5ac91c..e057f6e2 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -331,6 +331,29 @@ rte_bsf32(uint32_t v)
 #define offsetof(TYPE, MEMBER)  __builtin_offsetof (TYPE, MEMBER)
 #endif
 
+/**
+ * Return pointer to the wrapping struct instance.
+ *
+ * Example:
+ *
+ *  struct wrapper {
+ *      ...
+ *      struct child c;
+ *      ...
+ *  };
+ *
+ *  struct child *x = obtain(...);
+ *  struct wrapper *w = container_of(x, struct wrapper, c);
+ */
+#ifndef container_of
+#define container_of(ptr, type, member)	__extension__ ({		\
+			const typeof(((type *)0)->member) *_ptr = (ptr); \
+			__attribute__((unused)) type *_target_ptr =	\
+				(type *)(ptr);				\
+			(type *)(((uintptr_t)_ptr) - offsetof(type, member)); \
+		})
+#endif
+
 #define _RTE_STR(x) #x
 /** Take a macro value and get a string version of it */
 #define RTE_STR(x) _RTE_STR(x)