diff options
Diffstat (limited to 'net/dsa/tag_ksz.c')
-rw-r--r-- | net/dsa/tag_ksz.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c new file mode 100644 index 000000000000..b94a334a1d02 --- /dev/null +++ b/net/dsa/tag_ksz.c @@ -0,0 +1,100 @@ +/* + * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling + * Copyright (c) 2017 Microchip Technology + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/etherdevice.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <net/dsa.h> +#include "dsa_priv.h" + +/* For Ingress (Host -> KSZ), 2 bytes are added before FCS. + * --------------------------------------------------------------------------- + * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes) + * --------------------------------------------------------------------------- + * tag0 : Prioritization (not used now) + * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5) + * + * For Egress (KSZ -> Host), 1 byte is added before FCS. + * --------------------------------------------------------------------------- + * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes) + * --------------------------------------------------------------------------- + * tag0 : zero-based value represents port + * (eg, 0x00=port1, 0x02=port3, 0x06=port7) + */ + +#define KSZ_INGRESS_TAG_LEN 2 +#define KSZ_EGRESS_TAG_LEN 1 + +static struct sk_buff *ksz_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct dsa_slave_priv *p = netdev_priv(dev); + struct sk_buff *nskb; + int padlen; + u8 *tag; + + padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len; + + if (skb_tailroom(skb) >= padlen + KSZ_INGRESS_TAG_LEN) { + nskb = skb; + } else { + nskb = alloc_skb(NET_IP_ALIGN + skb->len + + padlen + KSZ_INGRESS_TAG_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)); + kfree_skb(skb); + } + + /* skb is freed when it fails */ + if (skb_put_padto(nskb, nskb->len + padlen)) + return NULL; + + tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN); + tag[0] = 0; + tag[1] = 1 << p->dp->index; /* destination port */ + + return nskb; +} + +static struct sk_buff *ksz_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, + struct net_device *orig_dev) +{ + struct dsa_switch_tree *dst = dev->dsa_ptr; + struct dsa_switch *ds; + u8 *tag; + int source_port; + + ds = dst->cpu_dp->ds; + + tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; + + source_port = tag[0] & 7; + if (source_port >= ds->num_ports || !ds->ports[source_port].netdev) + return NULL; + + pskb_trim_rcsum(skb, skb->len - KSZ_EGRESS_TAG_LEN); + + skb->dev = ds->ports[source_port].netdev; + + return skb; +} + +const struct dsa_device_ops ksz_netdev_ops = { + .xmit = ksz_xmit, + .rcv = ksz_rcv, +}; |