hmac_sha512_preparekey
hmac_sha512_preparekey(HMAC_SHA512_KEY(tfm), raw_key, keylen);
hmac_sha512_preparekey(&k.sha512, raw_key, raw_key_len);
hmac_sha512_preparekey(&key, auth_key, auth_keylen);
hmac_sha512_preparekey(hkdf, prk, sizeof(prk));
void hmac_sha512_preparekey(struct hmac_sha512_key *key,
EXPORT_SYMBOL_GPL(hmac_sha512_preparekey);
#define HMAC_PREPAREKEY hmac_sha512_preparekey