diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c
index 5991434f62a3..ea5ff1827d08 100644
--- a/drivers/firmware/turris-mox-rwtm.c
+++ b/drivers/firmware/turris-mox-rwtm.c
@@ -189,6 +189,34 @@ static void mox_rwtm_rx_callback(struct mbox_client *cl, void *data)
 	complete(&rwtm->cmd_done);
 }
 
+static int mox_rwtm_exec(struct mox_rwtm *rwtm, enum mbox_cmd cmd,
+			 struct armada_37xx_rwtm_tx_msg *msg,
+			 bool interruptible)
+{
+	struct armada_37xx_rwtm_tx_msg _msg = {};
+	int ret;
+
+	if (!msg)
+		msg = &_msg;
+
+	msg->command = cmd;
+
+	ret = mbox_send_message(rwtm->mbox, msg);
+	if (ret < 0)
+		return ret;
+
+	if (interruptible) {
+		ret = wait_for_completion_interruptible(&rwtm->cmd_done);
+		if (ret < 0)
+			return ret;
+	} else {
+		if (!wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2))
+			return -ETIMEDOUT;
+	}
+
+	return mox_get_status(cmd, rwtm->reply.retval);
+}
+
 static void reply_to_mac_addr(u8 *mac, u32 t1, u32 t2)
 {
 	mac[0] = t1 >> 8;
@@ -202,19 +230,10 @@ static void reply_to_mac_addr(u8 *mac, u32 t1, u32 t2)
 static int mox_get_board_info(struct mox_rwtm *rwtm)
 {
 	struct device *dev = rwtm_dev(rwtm);
-	struct armada_37xx_rwtm_tx_msg msg;
 	struct armada_37xx_rwtm_rx_msg *reply = &rwtm->reply;
 	int ret;
 
-	msg.command = MBOX_CMD_BOARD_INFO;
-	ret = mbox_send_message(rwtm->mbox, &msg);
-	if (ret < 0)
-		return ret;
-
-	if (!wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2))
-		return -ETIMEDOUT;
-
-	ret = mox_get_status(MBOX_CMD_BOARD_INFO, reply->retval);
+	ret = mox_rwtm_exec(rwtm, MBOX_CMD_BOARD_INFO, NULL, false);
 	if (ret == -ENODATA) {
 		dev_warn(dev,
 			 "Board does not have manufacturing information burned!\n");
@@ -241,15 +260,7 @@ static int mox_get_board_info(struct mox_rwtm *rwtm)
 		pr_info("           burned RAM size %i MiB\n", rwtm->ram_size);
 	}
 
-	msg.command = MBOX_CMD_ECDSA_PUB_KEY;
-	ret = mbox_send_message(rwtm->mbox, &msg);
-	if (ret < 0)
-		return ret;
-
-	if (!wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2))
-		return -ETIMEDOUT;
-
-	ret = mox_get_status(MBOX_CMD_ECDSA_PUB_KEY, reply->retval);
+	ret = mox_rwtm_exec(rwtm, MBOX_CMD_ECDSA_PUB_KEY, NULL, false);
 	if (ret == -ENODATA) {
 		dev_warn(dev, "Board has no public key burned!\n");
 	} else if (ret == -ENOSYS) {
@@ -272,38 +283,24 @@ static int mox_get_board_info(struct mox_rwtm *rwtm)
 
 static int check_get_random_support(struct mox_rwtm *rwtm)
 {
-	struct armada_37xx_rwtm_tx_msg msg;
-	int ret;
-
-	msg.command = MBOX_CMD_GET_RANDOM;
-	msg.args[0] = 1;
-	msg.args[1] = rwtm->buf_phys;
-	msg.args[2] = 4;
-
-	ret = mbox_send_message(rwtm->mbox, &msg);
-	if (ret < 0)
-		return ret;
-
-	if (!wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2))
-		return -ETIMEDOUT;
+	struct armada_37xx_rwtm_tx_msg msg = {
+		.args = { 1, rwtm->buf_phys, 4 },
+	};
 
-	return mox_get_status(MBOX_CMD_GET_RANDOM, rwtm->reply.retval);
+	return mox_rwtm_exec(rwtm, MBOX_CMD_GET_RANDOM, &msg, false);
 }
 
 static int mox_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 {
 	struct mox_rwtm *rwtm = container_of(rng, struct mox_rwtm, hwrng);
-	struct armada_37xx_rwtm_tx_msg msg;
+	struct armada_37xx_rwtm_tx_msg msg = {
+		.args = { 1, rwtm->buf_phys, (max + 3) & ~3 },
+	};
 	int ret;
 
 	if (max > PAGE_SIZE)
 		max = PAGE_SIZE;
 
-	msg.command = MBOX_CMD_GET_RANDOM;
-	msg.args[0] = 1;
-	msg.args[1] = rwtm->buf_phys;
-	msg.args[2] = (max + 3) & ~3;
-
 	if (!wait) {
 		if (!mutex_trylock(&rwtm->busy))
 			return -EBUSY;
@@ -311,15 +308,7 @@ static int mox_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 		mutex_lock(&rwtm->busy);
 	}
 
-	ret = mbox_send_message(rwtm->mbox, &msg);
-	if (ret < 0)
-		goto unlock_mutex;
-
-	ret = wait_for_completion_interruptible(&rwtm->cmd_done);
-	if (ret < 0)
-		goto unlock_mutex;
-
-	ret = mox_get_status(MBOX_CMD_GET_RANDOM, rwtm->reply.retval);
+	ret = mox_rwtm_exec(rwtm, MBOX_CMD_GET_RANDOM, &msg, true);
 	if (ret < 0)
 		goto unlock_mutex;
 
@@ -367,7 +356,6 @@ static ssize_t do_sign_write(struct file *file, const char __user *buf,
 			     size_t len, loff_t *ppos)
 {
 	struct mox_rwtm *rwtm = file->private_data;
-	struct armada_37xx_rwtm_rx_msg *reply = &rwtm->reply;
 	struct armada_37xx_rwtm_tx_msg msg;
 	loff_t dummy = 0;
 	ssize_t ret;
@@ -400,23 +388,15 @@ static ssize_t do_sign_write(struct file *file, const char __user *buf,
 		goto unlock_mutex;
 	be32_to_cpu_array(rwtm->buf, rwtm->buf, MOX_ECC_NUMBER_WORDS);
 
-	msg.command = MBOX_CMD_SIGN;
 	msg.args[0] = 1;
 	msg.args[1] = rwtm->buf_phys;
 	msg.args[2] = rwtm->buf_phys + MOX_ECC_NUMBER_LEN;
 	msg.args[3] = rwtm->buf_phys + 2 * MOX_ECC_NUMBER_LEN;
-	ret = mbox_send_message(rwtm->mbox, &msg);
-	if (ret < 0)
-		goto unlock_mutex;
 
-	ret = wait_for_completion_interruptible(&rwtm->cmd_done);
+	ret = mox_rwtm_exec(rwtm, MBOX_CMD_SIGN, &msg, true);
 	if (ret < 0)
 		goto unlock_mutex;
 
-	ret = MBOX_STS_VALUE(reply->retval);
-	if (MBOX_STS_ERROR(reply->retval) != MBOX_STS_SUCCESS)
-		goto unlock_mutex;
-
 	/*
 	 * Here we read the R and S values of the ECDSA signature
 	 * computed by the rWTM firmware and convert their words from
