New upstream version 18.11-rc3

[deb_dpdk.git] / lib / librte_eal / common / include / rte_common.h

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 069c13e..87f0f63 100644 (file)
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -68,6 +68,11 @@ typedef uint16_t unaligned_uint16_t;
 /******* Macro to mark functions and fields scheduled for removal *****/
 #define __rte_deprecated       __attribute__((__deprecated__))
 
+/**
+ * Mark a function or variable to a weak reference.
+ */
+#define __rte_weak __attribute__((__weak__))
+
 /*********** Macros to eliminate unused variable warnings ********/
 
 /**
@@ -164,6 +169,12 @@ static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
  */
 #define RTE_PTR_DIFF(ptr1, ptr2) ((uintptr_t)(ptr1) - (uintptr_t)(ptr2))
 
+/**
+ * Workaround to cast a const field of a structure to non-const type.
+ */
+#define RTE_CAST_FIELD(var, field, type) \
+       (*(type *)((uintptr_t)(var) + offsetof(typeof(*(var)), field)))
+
 /*********** Macros/static functions for doing alignment ********/
 
 
@@ -462,6 +473,25 @@ rte_log2_u32(uint32_t v)
        return rte_bsf32(v);
 }
 
+
+/**
+ * Return the last (most-significant) bit set.
+ *
+ * @note The last (most significant) bit is at position 32.
+ * @note rte_fls_u32(0) = 0, rte_fls_u32(1) = 1, rte_fls_u32(0x80000000) = 32
+ *
+ * @param x
+ *     The input parameter.
+ * @return
+ *     The last (most-significant) bit set, or 0 if the input is 0.
+ */
+static inline int
+rte_fls_u32(uint32_t x)
+{
+       return (x == 0) ? 0 : 32 - __builtin_clz(x);
+}
+
+
 #ifndef offsetof
 /** Return the offset of a field in a structure. */
 #define offsetof(TYPE, MEMBER)  __builtin_offsetof (TYPE, MEMBER)