While going thro’ run time power management code in K39 power/runtime.c file, am seeing a function definition as given below. Any idea, what “__releases” & “__acquires” are doing in this function definition?

 

static int rpm_callback(int (*cb)(struct device *), struct device *dev)

                __releases(&dev->power.lock) __acquires(&dev->power.lock)

{

                int retval;

                ….

                return retval;

}