can: c_can: rename IF_RX -> IF_NAPI

The C_CAN/D_CAN cores implement 2 interfaces to manage the message
objects. To avoid concurrency and the need for locking one interface
is used in the TX path (IF_TX). While the other one, named IF_RX is
used from NAPI context only. As this interface is not only used to
manage RX, but also TX message objects, this patch renames IF_RX to
IF_NAPI.

Link: https://lore.kernel.org/r/20210809080608.171545-1-mkl@pengutronix.de
Cc: Dario Binacchi <dariobin@libero.it>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/c_can/c_can_main.c

@@ -160,8 +160,8 @@
 
 #define IF_MCONT_TX		(IF_MCONT_TXIE | IF_MCONT_EOB)
 
-/* Use IF1 for RX and IF2 for TX */
-#define IF_RX			0
+/* Use IF1 in NAPI path and IF2 in TX path */
+#define IF_NAPI			0
 #define IF_TX			1
 
 /* minimum timeout for checking BUSY status */
@@ -529,13 +529,13 @@ static void c_can_configure_msg_objects(struct net_device *dev)
 
 	/* first invalidate all message objects */
 	for (i = priv->msg_obj_rx_first; i <= priv->msg_obj_num; i++)
-		c_can_inval_msg_object(dev, IF_RX, i);
+		c_can_inval_msg_object(dev, IF_NAPI, i);
 
 	/* setup receive message objects */
 	for (i = priv->msg_obj_rx_first; i < priv->msg_obj_rx_last; i++)
-		c_can_setup_receive_object(dev, IF_RX, i, 0, 0, IF_MCONT_RCV);
+		c_can_setup_receive_object(dev, IF_NAPI, i, 0, 0, IF_MCONT_RCV);
 
-	c_can_setup_receive_object(dev, IF_RX, priv->msg_obj_rx_last, 0, 0,
+	c_can_setup_receive_object(dev, IF_NAPI, priv->msg_obj_rx_last, 0, 0,
 				   IF_MCONT_RCV_EOB);
 }
 
@@ -710,11 +710,11 @@ static void c_can_do_tx(struct net_device *dev)
 		pend &= ~BIT(idx);
 		obj = idx + priv->msg_obj_tx_first;
 
-		/* We use IF_RX interface instead of IF_TX because we
+		/* We use IF_NAPI interface instead of IF_TX because we
 		 * are called from c_can_poll(), which runs inside
 		 * NAPI. We are not transmitting.
 		 */
-		c_can_inval_tx_object(dev, IF_RX, obj);
+		c_can_inval_tx_object(dev, IF_NAPI, obj);
 		can_get_echo_skb(dev, idx, NULL);
 		bytes += priv->dlc[idx];
 		pkts++;
@@ -766,14 +766,14 @@ static u32 c_can_adjust_pending(u32 pend, u32 rx_mask)
 static inline void c_can_rx_object_get(struct net_device *dev,
 				       struct c_can_priv *priv, u32 obj)
 {
-	c_can_object_get(dev, IF_RX, obj, priv->comm_rcv_high);
+	c_can_object_get(dev, IF_NAPI, obj, priv->comm_rcv_high);
 }
 
 static inline void c_can_rx_finalize(struct net_device *dev,
 				     struct c_can_priv *priv, u32 obj)
 {
 	if (priv->type != BOSCH_D_CAN)
-		c_can_object_get(dev, IF_RX, obj, IF_COMM_CLR_NEWDAT);
+		c_can_object_get(dev, IF_NAPI, obj, IF_COMM_CLR_NEWDAT);
 }
 
 static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv,
@@ -785,10 +785,12 @@ static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv,
 		pend &= ~BIT(obj - 1);
 
 		c_can_rx_object_get(dev, priv, obj);
-		ctrl = priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, IF_RX));
+		ctrl = priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, IF_NAPI));
 
 		if (ctrl & IF_MCONT_MSGLST) {
-			int n = c_can_handle_lost_msg_obj(dev, IF_RX, obj, ctrl);
+			int n;
+
+			n = c_can_handle_lost_msg_obj(dev, IF_NAPI, obj, ctrl);
 
 			pkts += n;
 			quota -= n;
@@ -803,7 +805,7 @@ static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv,
 			continue;
 
 		/* read the data from the message object */
-		c_can_read_msg_object(dev, IF_RX, ctrl);
+		c_can_read_msg_object(dev, IF_NAPI, ctrl);
 
 		c_can_rx_finalize(dev, priv, obj);