dthe_copy_sg
sg = dthe_copy_sg(src, req->src, req->cryptlen);
sg = dthe_copy_sg(dst, req->dst, req->cryptlen);
to_sg = dthe_copy_sg(aad_sg, sg, assoclen);
to_sg = dthe_copy_sg(crypt_sg, out_sg[0], cryptlen);
struct scatterlist *dthe_copy_sg(struct scatterlist *dst,