+/**
+ * atomic_add_return - add and return
+ * @v: pointer of type atomic_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static __inline__ int atomic_add_return(int i, atomic_t *v)
+{
+ int __i;
+#ifdef CONFIG_M386
+ unsigned long flags;
+ if(unlikely(boot_cpu_data.x86==3))
+ goto no_xadd;
+#endif
+ /* Modern 486+ processor */
+ __i = i;
+ __asm__ __volatile__(
+ LOCK_PREFIX "xaddl %0, %1"
+ :"+r" (i), "+m" (v->counter)
+ : : "memory");
+ return i + __i;
+
+#ifdef CONFIG_M386
+no_xadd: /* Legacy 386 processor */
+ local_irq_save(flags);
+ __i = atomic_read(v);
+ atomic_set(v, i + __i);
+ local_irq_restore(flags);
+ return i + __i;
+#endif
+}
+
+static __inline__ int atomic_sub_return(int i, atomic_t *v)
+{
+ return atomic_add_return(-i,v);
+}
+
+#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+/**
+ * atomic_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+#define atomic_add_unless(v, a, u) \
+({ \
+ int c, old; \
+ c = atomic_read(v); \
+ for (;;) { \
+ if (unlikely(c == (u))) \
+ break; \
+ old = atomic_cmpxchg((v), c, c + (a)); \
+ if (likely(old == c)) \
+ break; \
+ c = old; \
+ } \
+ c != (u); \
+})
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
+#define atomic_inc_return(v) (atomic_add_return(1,v))
+#define atomic_dec_return(v) (atomic_sub_return(1,v))
+