From 88fda8eefd9a7a7175bf4dad1d02cc0840581111 Mon Sep 17 00:00:00 2001 From: Christian Eggers Date: Sun, 1 Nov 2020 21:16:10 +0200 Subject: [PATCH] net: dsa: tag_ksz: don't allocate additional memory for padding/tagging The caller (dsa_slave_xmit) guarantees that the frame length is at least ETH_ZLEN and that enough memory for tail tagging is available. Signed-off-by: Christian Eggers Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski --- net/dsa/tag_ksz.c | 73 +++++++------------------------------------------------ 1 file changed, 9 insertions(+), 64 deletions(-) diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c index 0a5aa98..4820dbc 100644 --- a/net/dsa/tag_ksz.c +++ b/net/dsa/tag_ksz.c @@ -14,46 +14,6 @@ #define KSZ_EGRESS_TAG_LEN 1 #define KSZ_INGRESS_TAG_LEN 1 -static struct sk_buff *ksz_common_xmit(struct sk_buff *skb, - struct net_device *dev, int len) -{ - struct sk_buff *nskb; - int padlen; - - padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len; - - if (skb_tailroom(skb) >= padlen + len) { - /* Let dsa_slave_xmit() free skb */ - if (__skb_put_padto(skb, skb->len + padlen, false)) - return NULL; - - nskb = skb; - } else { - nskb = alloc_skb(NET_IP_ALIGN + skb->len + - padlen + len, GFP_ATOMIC); - if (!nskb) - return NULL; - skb_reserve(nskb, NET_IP_ALIGN); - - skb_reset_mac_header(nskb); - skb_set_network_header(nskb, - skb_network_header(skb) - skb->head); - skb_set_transport_header(nskb, - skb_transport_header(skb) - skb->head); - skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len)); - - /* Let skb_put_padto() free nskb, and let dsa_slave_xmit() free - * skb - */ - if (skb_put_padto(nskb, nskb->len + padlen)) - return NULL; - - consume_skb(skb); - } - - return nskb; -} - static struct sk_buff *ksz_common_rcv(struct sk_buff *skb, struct net_device *dev, unsigned int port, unsigned int len) @@ -90,23 +50,18 @@ static struct sk_buff *ksz_common_rcv(struct sk_buff *skb, static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); - struct sk_buff *nskb; u8 *tag; u8 *addr; - nskb = ksz_common_xmit(skb, dev, KSZ_INGRESS_TAG_LEN); - if (!nskb) - return NULL; - /* Tag encoding */ - tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN); - addr = skb_mac_header(nskb); + tag = skb_put(skb, KSZ_INGRESS_TAG_LEN); + addr = skb_mac_header(skb); *tag = 1 << dp->index; if (is_link_local_ether_addr(addr)) *tag |= KSZ8795_TAIL_TAG_OVERRIDE; - return nskb; + return skb; } static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev, @@ -156,18 +111,13 @@ static struct sk_buff *ksz9477_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); - struct sk_buff *nskb; __be16 *tag; u8 *addr; u16 val; - nskb = ksz_common_xmit(skb, dev, KSZ9477_INGRESS_TAG_LEN); - if (!nskb) - return NULL; - /* Tag encoding */ - tag = skb_put(nskb, KSZ9477_INGRESS_TAG_LEN); - addr = skb_mac_header(nskb); + tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN); + addr = skb_mac_header(skb); val = BIT(dp->index); @@ -176,7 +126,7 @@ static struct sk_buff *ksz9477_xmit(struct sk_buff *skb, *tag = cpu_to_be16(val); - return nskb; + return skb; } static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev, @@ -213,24 +163,19 @@ static struct sk_buff *ksz9893_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); - struct sk_buff *nskb; u8 *addr; u8 *tag; - nskb = ksz_common_xmit(skb, dev, KSZ_INGRESS_TAG_LEN); - if (!nskb) - return NULL; - /* Tag encoding */ - tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN); - addr = skb_mac_header(nskb); + tag = skb_put(skb, KSZ_INGRESS_TAG_LEN); + addr = skb_mac_header(skb); *tag = BIT(dp->index); if (is_link_local_ether_addr(addr)) *tag |= KSZ9893_TAIL_TAG_OVERRIDE; - return nskb; + return skb; } static const struct dsa_device_ops ksz9893_netdev_ops = { -- 2.7.4