crng
static DEFINE_PER_CPU(struct crng, crngs) = {
struct crng *crng;
crng = raw_cpu_ptr(&crngs);
if (unlikely(crng->generation != READ_ONCE(base_crng.generation))) {
crng->key, sizeof(crng->key));
crng->generation = base_crng.generation;
crng_fast_key_erasure(crng->key, chacha_state, random_data, random_data_len);