ASYNC_HEADER_Q3_DATA_LENGTH_MASK
header[3] &= ~ASYNC_HEADER_Q3_DATA_LENGTH_MASK;
header[3] |= (((u32)data_length) << ASYNC_HEADER_Q3_DATA_LENGTH_SHIFT) & ASYNC_HEADER_Q3_DATA_LENGTH_MASK;
return (header[3] & ASYNC_HEADER_Q3_DATA_LENGTH_MASK) >> ASYNC_HEADER_Q3_DATA_LENGTH_SHIFT;