can: dev: can_rx_offload_get_echo_skb(): extend to return can frame length

In order to implement byte queue limits (bql) in CAN drivers, the length of the
CAN frame needs to be passed into the networking stack after queueing and after
transmission completion.

To avoid to calculate this length twice, extend can_rx_offload_get_echo_skb()
to return that value. Convert all users of this function, too.
Reviewed-by: NVincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-15-mkl@pengutronix.deSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/dev/rx-offload.c

@@ -263,7 +263,8 @@ int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
 EXPORT_SYMBOL_GPL(can_rx_offload_queue_sorted);
 
 unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
-					 unsigned int idx, u32 timestamp)
+					 unsigned int idx, u32 timestamp,
+					 unsigned int *frame_len_ptr)
 {
 	struct net_device *dev = offload->dev;
 	struct net_device_stats *stats = &dev->stats;
@@ -271,7 +272,7 @@ unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
 	u8 len;
 	int err;
 
-	skb = __can_get_echo_skb(dev, idx, &len, NULL);
+	skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
 	if (!skb)
 		return 0;
 

drivers/net/can/flexcan.c

@@ -1122,8 +1122,9 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 		u32 reg_ctrl = priv->read(&priv->tx_mb->can_ctrl);
 
 		handled = IRQ_HANDLED;
-		stats->tx_bytes += can_rx_offload_get_echo_skb(&priv->offload,
-							       0, reg_ctrl << 16);
+		stats->tx_bytes +=
+			can_rx_offload_get_echo_skb(&priv->offload, 0,
+						    reg_ctrl << 16, NULL);
 		stats->tx_packets++;
 		can_led_event(dev, CAN_LED_EVENT_TX);
 

drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c

@@ -1271,7 +1271,7 @@ mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
 	stats->tx_bytes +=
 		can_rx_offload_get_echo_skb(&priv->offload,
 					    mcp251xfd_get_tef_tail(priv),
-					    hw_tef_obj->ts);
+					    hw_tef_obj->ts, NULL);
 	stats->tx_packets++;
 	priv->tef->tail++;
 

drivers/net/can/ti_hecc.c

@@ -757,7 +757,7 @@ static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
 			stamp = hecc_read_stamp(priv, mbxno);
 			stats->tx_bytes +=
 				can_rx_offload_get_echo_skb(&priv->offload,
-							    mbxno, stamp);
+							    mbxno, stamp, NULL);
 			stats->tx_packets++;
 			can_led_event(ndev, CAN_LED_EVENT_TX);
 			--priv->tx_tail;

include/linux/can/rx-offload.h

@@ -44,7 +44,8 @@ int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload);
 int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
 				struct sk_buff *skb, u32 timestamp);
 unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
-					 unsigned int idx, u32 timestamp);
+					 unsigned int idx, u32 timestamp,
+					 unsigned int *frame_len_ptr);
 int can_rx_offload_queue_tail(struct can_rx_offload *offload,
 			      struct sk_buff *skb);
 void can_rx_offload_del(struct can_rx_offload *offload);