#error libdrm requires atomic operations, please define them for your CPU/compiler.
#endif
+static inline int atomic_add_unless(atomic_t *v, int add, int unless)
+{
+ int c, old;
+ c = atomic_read(v);
+ while (c != unless && (old = atomic_cmpxchg(v, c, c + add)) != c)
+ c = old;
+ return c == unless;
+}
+
#endif