can: dev: can_free_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
even if the transmission failed for some reason.

To avoid to calculate this length twice, extend can_free_echo_skb() to
return that value. Convert all users of this function, too.

This patch is the natural extension of commit:

| 9420e1d4 ("can: dev: can_get_echo_skb(): extend to return can
|                frame length")

Link: https://lore.kernel.org/r/20210319142700.305648-3-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/dev/skb.c

@@ -153,7 +153,8 @@ EXPORT_SYMBOL_GPL(can_get_echo_skb);
  *
  * The function is typically called when TX failed.
  */
-void can_free_echo_skb(struct net_device *dev, unsigned int idx)
+void can_free_echo_skb(struct net_device *dev, unsigned int idx,
+		       unsigned int *frame_len_ptr)
 {
 	struct can_priv *priv = netdev_priv(dev);
 
@@ -164,7 +165,13 @@ void can_free_echo_skb(struct net_device *dev, unsigned int idx)
 	}
 
 	if (priv->echo_skb[idx]) {
-		dev_kfree_skb_any(priv->echo_skb[idx]);
+		struct sk_buff *skb = priv->echo_skb[idx];
+		struct can_skb_priv *can_skb_priv = can_skb_prv(skb);
+
+		if (frame_len_ptr)
+			*frame_len_ptr = can_skb_priv->frame_len;
+
+		dev_kfree_skb_any(skb);
 		priv->echo_skb[idx] = NULL;
 	}
 }

drivers/net/can/grcan.c

@@ -520,7 +520,7 @@ static int catch_up_echo_skb(struct net_device *dev, int budget, bool echo)
 			can_get_echo_skb(dev, i, NULL);
 		} else {
 			/* For cleanup of untransmitted messages */
-			can_free_echo_skb(dev, i);
+			can_free_echo_skb(dev, i, NULL);
 		}
 
 		priv->eskbp = grcan_ring_add(priv->eskbp, GRCAN_MSG_SIZE,

drivers/net/can/m_can/m_can.c

@@ -425,7 +425,7 @@ static void m_can_clean(struct net_device *net)
 			putidx = ((m_can_read(cdev, M_CAN_TXFQS) &
 				   TXFQS_TFQPI_MASK) >> TXFQS_TFQPI_SHIFT);
 
-		can_free_echo_skb(cdev->net, putidx);
+		can_free_echo_skb(cdev->net, putidx, NULL);
 		cdev->tx_skb = NULL;
 	}
 }

drivers/net/can/rcar/rcar_can.c

@@ -217,7 +217,7 @@ static void tx_failure_cleanup(struct net_device *ndev)
 	int i;
 
 	for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++)
-		can_free_echo_skb(ndev, i);
+		can_free_echo_skb(ndev, i, NULL);
 }
 
 static void rcar_can_error(struct net_device *ndev)

drivers/net/can/rcar/rcar_canfd.c

@@ -617,7 +617,7 @@ static void rcar_canfd_tx_failure_cleanup(struct net_device *ndev)
 	u32 i;
 
 	for (i = 0; i < RCANFD_FIFO_DEPTH; i++)
-		can_free_echo_skb(ndev, i);
+		can_free_echo_skb(ndev, i, NULL);
 }
 
 static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)

drivers/net/can/sja1000/sja1000.c

@@ -525,7 +525,7 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
 			if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
 			    !(status & SR_TCS)) {
 				stats->tx_errors++;
-				can_free_echo_skb(dev, 0);
+				can_free_echo_skb(dev, 0, NULL);
 			} else {
 				/* transmission complete */
 				stats->tx_bytes +=

drivers/net/can/spi/hi311x.c

@@ -179,7 +179,7 @@ static void hi3110_clean(struct net_device *net)
 		net->stats.tx_errors++;
 	dev_kfree_skb(priv->tx_skb);
 	if (priv->tx_len)
-		can_free_echo_skb(priv->net, 0);
+		can_free_echo_skb(priv->net, 0, NULL);
 	priv->tx_skb = NULL;
 	priv->tx_len = 0;
 }

drivers/net/can/spi/mcp251x.c

@@ -276,7 +276,7 @@ static void mcp251x_clean(struct net_device *net)
 		net->stats.tx_errors++;
 	dev_kfree_skb(priv->tx_skb);
 	if (priv->tx_len)
-		can_free_echo_skb(priv->net, 0);
+		can_free_echo_skb(priv->net, 0, NULL);
 	priv->tx_skb = NULL;
 	priv->tx_len = 0;
 }

drivers/net/can/usb/ems_usb.c

@@ -807,7 +807,7 @@ static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *ne
 
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (unlikely(err)) {
-		can_free_echo_skb(netdev, context->echo_index);
+		can_free_echo_skb(netdev, context->echo_index, NULL);
 
 		usb_unanchor_urb(urb);
 		usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);

drivers/net/can/usb/esd_usb2.c

@@ -360,7 +360,7 @@ static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
 		can_get_echo_skb(netdev, context->echo_index, NULL);
 	} else {
 		stats->tx_errors++;
-		can_free_echo_skb(netdev, context->echo_index);
+		can_free_echo_skb(netdev, context->echo_index, NULL);
 	}
 
 	/* Release context */
@@ -793,7 +793,7 @@ static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
 
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err) {
-		can_free_echo_skb(netdev, context->echo_index);
+		can_free_echo_skb(netdev, context->echo_index, NULL);
 
 		atomic_dec(&priv->active_tx_jobs);
 		usb_unanchor_urb(urb);

drivers/net/can/usb/gs_usb.c

@@ -533,7 +533,7 @@ static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 	if (unlikely(rc)) {			/* usb send failed */
 		atomic_dec(&dev->active_tx_urbs);
 
-		can_free_echo_skb(netdev, idx);
+		can_free_echo_skb(netdev, idx, NULL);
 		gs_free_tx_context(txc);
 
 		usb_unanchor_urb(urb);

drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c

@@ -593,7 +593,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
 	if (unlikely(err)) {
 		spin_lock_irqsave(&priv->tx_contexts_lock, flags);
 
-		can_free_echo_skb(netdev, context->echo_index);
+		can_free_echo_skb(netdev, context->echo_index, NULL);
 		context->echo_index = dev->max_tx_urbs;
 		--priv->active_tx_contexts;
 		netif_wake_queue(netdev);

drivers/net/can/usb/mcba_usb.c

@@ -364,7 +364,7 @@ static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 
 xmit_failed:
-	can_free_echo_skb(priv->netdev, ctx->ndx);
+	can_free_echo_skb(priv->netdev, ctx->ndx, NULL);
 	mcba_usb_free_ctx(ctx);
 	dev_kfree_skb(skb);
 	stats->tx_dropped++;

drivers/net/can/usb/peak_usb/pcan_usb_core.c

@@ -371,7 +371,7 @@ static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err) {
-		can_free_echo_skb(netdev, context->echo_index);
+		can_free_echo_skb(netdev, context->echo_index, NULL);
 
 		usb_unanchor_urb(urb);
 

drivers/net/can/usb/ucan.c

@@ -675,7 +675,7 @@ static void ucan_tx_complete_msg(struct ucan_priv *up,
 			can_get_echo_skb(up->netdev, echo_index, NULL);
 		} else {
 			up->netdev->stats.tx_dropped++;
-			can_free_echo_skb(up->netdev, echo_index);
+			can_free_echo_skb(up->netdev, echo_index, NULL);
 		}
 		spin_unlock_irqrestore(&up->echo_skb_lock, flags);
 	}
@@ -843,7 +843,7 @@ static void ucan_write_bulk_callback(struct urb *urb)
 
 		/* update counters an cleanup */
 		spin_lock_irqsave(&up->echo_skb_lock, flags);
-		can_free_echo_skb(up->netdev, context - up->context_array);
+		can_free_echo_skb(up->netdev, context - up->context_array, NULL);
 		spin_unlock_irqrestore(&up->echo_skb_lock, flags);
 
 		up->netdev->stats.tx_dropped++;
@@ -1157,7 +1157,7 @@ static netdev_tx_t ucan_start_xmit(struct sk_buff *skb,
 		 * frees the skb
 		 */
 		spin_lock_irqsave(&up->echo_skb_lock, flags);
-		can_free_echo_skb(up->netdev, echo_index);
+		can_free_echo_skb(up->netdev, echo_index, NULL);
 		spin_unlock_irqrestore(&up->echo_skb_lock, flags);
 
 		if (ret == -ENODEV) {

drivers/net/can/usb/usb_8dev.c

@@ -691,7 +691,7 @@ static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 	return NETDEV_TX_BUSY;
 
 failed:
-	can_free_echo_skb(netdev, context->echo_index);
+	can_free_echo_skb(netdev, context->echo_index, NULL);
 
 	usb_unanchor_urb(urb);
 	usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);

include/linux/can/skb.h

@@ -23,7 +23,8 @@ struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
 				   u8 *len_ptr, unsigned int *frame_len_ptr);
 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx,
 			      unsigned int *frame_len_ptr);
-void can_free_echo_skb(struct net_device *dev, unsigned int idx);
+void can_free_echo_skb(struct net_device *dev, unsigned int idx,
+		       unsigned int *frame_len_ptr);
 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 				struct canfd_frame **cfd);