+int nvme_auth_generate_key(struct nvme_ctrl *ctrl, u8 *secret, bool set_ctrl)

Maybe instead of set_ctrl introduct struct dhchap_key and pass a pointer
into that?

+{
+	u8 *key;
+	size_t key_len;
+	u8 key_hash;
+
+	if (!secret)
+		return 0;
+
+	if (sscanf(secret, "DHHC-1:%hhd:%*s:", &key_hash) != 1)
+		return -EINVAL;
+
+	/* Pass in the secret without the 'DHHC-1:XX:' prefix */
+	key = nvme_auth_extract_secret(secret + 10, key_hash,
+				       &key_len);
+	if (IS_ERR(key)) {
+		dev_dbg(ctrl->device, "failed to extract key, error %ld\n",
+			PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	if (set_ctrl) {
+		ctrl->dhchap_ctrl_key = key;
+		ctrl->dhchap_ctrl_key_len = key_len;
+		ctrl->dhchap_ctrl_key_hash = key_hash;
+	} else {
+		ctrl->dhchap_key = key;
+		ctrl->dhchap_key_len = key_len;
+		ctrl->dhchap_key_hash = key_hash;
+	}

Then it becomes:
	dhchap_key->key = key;
	dhchap_key->len = key_len;
	dhchap_key->hash = key_hash;