can: dev: move skb related into seperate file

This patch moves the skb related code of the CAN device infrastructure into a
separate file.

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

3 files changed, 221 insertions, 213 deletions

diff --git a/drivers/net/can/dev/Makefile b/drivers/net/can/dev/Makefile
index 5c647951e06d..188bd53b113c 100644
--- a/drivers/net/can/dev/Makefile
+++ b/drivers/net/can/dev/Makefile
@@ -5,5 +5,6 @@ can-dev-y			+= bittiming.o
 can-dev-y			+= dev.o
 can-dev-y			+= length.o
 can-dev-y			+= rx-offload.o
+can-dev-y                       += skb.o
 
 can-dev-$(CONFIG_CAN_LEDS)	+= led.o
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index 3372e99d5db7..fe71ff9ef8c9 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -132,149 +132,6 @@ void can_change_state(struct net_device *dev, struct can_frame *cf,
 }
 EXPORT_SYMBOL_GPL(can_change_state);
 
-/* Local echo of CAN messages
- *
- * CAN network devices *should* support a local echo functionality
- * (see Documentation/networking/can.rst). To test the handling of CAN
- * interfaces that do not support the local echo both driver types are
- * implemented. In the case that the driver does not support the echo
- * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
- * to perform the echo as a fallback solution.
- */
-static void can_flush_echo_skb(struct net_device *dev)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	struct net_device_stats *stats = &dev->stats;
-	int i;
-
-	for (i = 0; i < priv->echo_skb_max; i++) {
-		if (priv->echo_skb[i]) {
-			kfree_skb(priv->echo_skb[i]);
-			priv->echo_skb[i] = NULL;
-			stats->tx_dropped++;
-			stats->tx_aborted_errors++;
-		}
-	}
-}
-
-/* Put the skb on the stack to be looped backed locally lateron
- *
- * The function is typically called in the start_xmit function
- * of the device driver. The driver must protect access to
- * priv->echo_skb, if necessary.
- */
-int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
-		     unsigned int idx)
-{
-	struct can_priv *priv = netdev_priv(dev);
-
-	BUG_ON(idx >= priv->echo_skb_max);
-
-	/* check flag whether this packet has to be looped back */
-	if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
-	    (skb->protocol != htons(ETH_P_CAN) &&
-	     skb->protocol != htons(ETH_P_CANFD))) {
-		kfree_skb(skb);
-		return 0;
-	}
-
-	if (!priv->echo_skb[idx]) {
-		skb = can_create_echo_skb(skb);
-		if (!skb)
-			return -ENOMEM;
-
-		/* make settings for echo to reduce code in irq context */
-		skb->pkt_type = PACKET_BROADCAST;
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		skb->dev = dev;
-
-		/* save this skb for tx interrupt echo handling */
-		priv->echo_skb[idx] = skb;
-	} else {
-		/* locking problem with netif_stop_queue() ?? */
-		netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx);
-		kfree_skb(skb);
-		return -EBUSY;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(can_put_echo_skb);
-
-struct sk_buff *
-__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
-{
-	struct can_priv *priv = netdev_priv(dev);
-
-	if (idx >= priv->echo_skb_max) {
-		netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
-			   __func__, idx, priv->echo_skb_max);
-		return NULL;
-	}
-
-	if (priv->echo_skb[idx]) {
-		/* Using "struct canfd_frame::len" for the frame
-		 * length is supported on both CAN and CANFD frames.
-		 */
-		struct sk_buff *skb = priv->echo_skb[idx];
-		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
-
-		/* get the real payload length for netdev statistics */
-		if (cf->can_id & CAN_RTR_FLAG)
-			*len_ptr = 0;
-		else
-			*len_ptr = cf->len;
-
-		priv->echo_skb[idx] = NULL;
-
-		return skb;
-	}
-
-	return NULL;
-}
-
-/* Get the skb from the stack and loop it back locally
- *
- * The function is typically called when the TX done interrupt
- * is handled in the device driver. The driver must protect
- * access to priv->echo_skb, if necessary.
- */
-unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
-{
-	struct sk_buff *skb;
-	u8 len;
-
-	skb = __can_get_echo_skb(dev, idx, &len);
-	if (!skb)
-		return 0;
-
-	skb_get(skb);
-	if (netif_rx(skb) == NET_RX_SUCCESS)
-		dev_consume_skb_any(skb);
-	else
-		dev_kfree_skb_any(skb);
-
-	return len;
-}
-EXPORT_SYMBOL_GPL(can_get_echo_skb);
-
-/* Remove the skb from the stack and free it.
- *
- * The function is typically called when TX failed.
- */
-void can_free_echo_skb(struct net_device *dev, unsigned int idx)
-{
-	struct can_priv *priv = netdev_priv(dev);
-
-	BUG_ON(idx >= priv->echo_skb_max);
-
-	if (priv->echo_skb[idx]) {
-		dev_kfree_skb_any(priv->echo_skb[idx]);
-		priv->echo_skb[idx] = NULL;
-	}
-}
-EXPORT_SYMBOL_GPL(can_free_echo_skb);
-
 /* CAN device restart for bus-off recovery */
 static void can_restart(struct net_device *dev)
 {
@@ -379,76 +236,6 @@ static void can_setup(struct net_device *dev)
 	dev->features = NETIF_F_HW_CSUM;
 }
 
-struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
-{
-	struct sk_buff *skb;
-
-	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
-			       sizeof(struct can_frame));
-	if (unlikely(!skb))
-		return NULL;
-
-	skb->protocol = htons(ETH_P_CAN);
-	skb->pkt_type = PACKET_BROADCAST;
-	skb->ip_summed = CHECKSUM_UNNECESSARY;
-
-	skb_reset_mac_header(skb);
-	skb_reset_network_header(skb);
-	skb_reset_transport_header(skb);
-
-	can_skb_reserve(skb);
-	can_skb_prv(skb)->ifindex = dev->ifindex;
-	can_skb_prv(skb)->skbcnt = 0;
-
-	*cf = skb_put_zero(skb, sizeof(struct can_frame));
-
-	return skb;
-}
-EXPORT_SYMBOL_GPL(alloc_can_skb);
-
-struct sk_buff *alloc_canfd_skb(struct net_device *dev,
-				struct canfd_frame **cfd)
-{
-	struct sk_buff *skb;
-
-	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
-			       sizeof(struct canfd_frame));
-	if (unlikely(!skb))
-		return NULL;
-
-	skb->protocol = htons(ETH_P_CANFD);
-	skb->pkt_type = PACKET_BROADCAST;
-	skb->ip_summed = CHECKSUM_UNNECESSARY;
-
-	skb_reset_mac_header(skb);
-	skb_reset_network_header(skb);
-	skb_reset_transport_header(skb);
-
-	can_skb_reserve(skb);
-	can_skb_prv(skb)->ifindex = dev->ifindex;
-	can_skb_prv(skb)->skbcnt = 0;
-
-	*cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
-
-	return skb;
-}
-EXPORT_SYMBOL_GPL(alloc_canfd_skb);
-
-struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
-{
-	struct sk_buff *skb;
-
-	skb = alloc_can_skb(dev, cf);
-	if (unlikely(!skb))
-		return NULL;
-
-	(*cf)->can_id = CAN_ERR_FLAG;
-	(*cf)->len = CAN_ERR_DLC;
-
-	return skb;
-}
-EXPORT_SYMBOL_GPL(alloc_can_err_skb);
-
 /* Allocate and setup space for the CAN network device */
 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 				    unsigned int txqs, unsigned int rxqs)
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
new file mode 100644
index 000000000000..26cd597ff771
--- /dev/null
+++ b/drivers/net/can/dev/skb.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
+ * Copyright (C) 2006 Andrey Volkov, Varma Electronics
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ */
+
+#include <linux/can/dev.h>
+
+/* Local echo of CAN messages
+ *
+ * CAN network devices *should* support a local echo functionality
+ * (see Documentation/networking/can.rst). To test the handling of CAN
+ * interfaces that do not support the local echo both driver types are
+ * implemented. In the case that the driver does not support the echo
+ * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
+ * to perform the echo as a fallback solution.
+ */
+void can_flush_echo_skb(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	struct net_device_stats *stats = &dev->stats;
+	int i;
+
+	for (i = 0; i < priv->echo_skb_max; i++) {
+		if (priv->echo_skb[i]) {
+			kfree_skb(priv->echo_skb[i]);
+			priv->echo_skb[i] = NULL;
+			stats->tx_dropped++;
+			stats->tx_aborted_errors++;
+		}
+	}
+}
+
+/* Put the skb on the stack to be looped backed locally lateron
+ *
+ * The function is typically called in the start_xmit function
+ * of the device driver. The driver must protect access to
+ * priv->echo_skb, if necessary.
+ */
+int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
+		     unsigned int idx)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	BUG_ON(idx >= priv->echo_skb_max);
+
+	/* check flag whether this packet has to be looped back */
+	if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
+	    (skb->protocol != htons(ETH_P_CAN) &&
+	     skb->protocol != htons(ETH_P_CANFD))) {
+		kfree_skb(skb);
+		return 0;
+	}
+
+	if (!priv->echo_skb[idx]) {
+		skb = can_create_echo_skb(skb);
+		if (!skb)
+			return -ENOMEM;
+
+		/* make settings for echo to reduce code in irq context */
+		skb->pkt_type = PACKET_BROADCAST;
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		skb->dev = dev;
+
+		/* save this skb for tx interrupt echo handling */
+		priv->echo_skb[idx] = skb;
+	} else {
+		/* locking problem with netif_stop_queue() ?? */
+		netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx);
+		kfree_skb(skb);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(can_put_echo_skb);
+
+struct sk_buff *
+__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (idx >= priv->echo_skb_max) {
+		netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
+			   __func__, idx, priv->echo_skb_max);
+		return NULL;
+	}
+
+	if (priv->echo_skb[idx]) {
+		/* Using "struct canfd_frame::len" for the frame
+		 * length is supported on both CAN and CANFD frames.
+		 */
+		struct sk_buff *skb = priv->echo_skb[idx];
+		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+
+		/* get the real payload length for netdev statistics */
+		if (cf->can_id & CAN_RTR_FLAG)
+			*len_ptr = 0;
+		else
+			*len_ptr = cf->len;
+
+		priv->echo_skb[idx] = NULL;
+
+		return skb;
+	}
+
+	return NULL;
+}
+
+/* Get the skb from the stack and loop it back locally
+ *
+ * The function is typically called when the TX done interrupt
+ * is handled in the device driver. The driver must protect
+ * access to priv->echo_skb, if necessary.
+ */
+unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
+{
+	struct sk_buff *skb;
+	u8 len;
+
+	skb = __can_get_echo_skb(dev, idx, &len);
+	if (!skb)
+		return 0;
+
+	skb_get(skb);
+	if (netif_rx(skb) == NET_RX_SUCCESS)
+		dev_consume_skb_any(skb);
+	else
+		dev_kfree_skb_any(skb);
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(can_get_echo_skb);
+
+/* Remove the skb from the stack and free it.
+ *
+ * The function is typically called when TX failed.
+ */
+void can_free_echo_skb(struct net_device *dev, unsigned int idx)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	BUG_ON(idx >= priv->echo_skb_max);
+
+	if (priv->echo_skb[idx]) {
+		dev_kfree_skb_any(priv->echo_skb[idx]);
+		priv->echo_skb[idx] = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(can_free_echo_skb);
+
+struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
+{
+	struct sk_buff *skb;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
+			       sizeof(struct can_frame));
+	if (unlikely(!skb))
+		return NULL;
+
+	skb->protocol = htons(ETH_P_CAN);
+	skb->pkt_type = PACKET_BROADCAST;
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+
+	*cf = skb_put_zero(skb, sizeof(struct can_frame));
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_can_skb);
+
+struct sk_buff *alloc_canfd_skb(struct net_device *dev,
+				struct canfd_frame **cfd)
+{
+	struct sk_buff *skb;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
+			       sizeof(struct canfd_frame));
+	if (unlikely(!skb))
+		return NULL;
+
+	skb->protocol = htons(ETH_P_CANFD);
+	skb->pkt_type = PACKET_BROADCAST;
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+
+	*cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_canfd_skb);
+
+struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_can_skb(dev, cf);
+	if (unlikely(!skb))
+		return NULL;
+
+	(*cf)->can_id = CAN_ERR_FLAG;
+	(*cf)->len = CAN_ERR_DLC;
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_can_err_skb);