diff options
Diffstat (limited to 'net/dsa/tag_brcm.c')
| -rw-r--r-- | net/dsa/tag_brcm.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c new file mode 100644 index 000000000000..e0b759ec209e --- /dev/null +++ b/net/dsa/tag_brcm.c @@ -0,0 +1,173 @@ +/* + * Broadcom tag support + * + * Copyright (C) 2014 Broadcom Corporation + * + * 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/netdevice.h> +#include <linux/slab.h> +#include "dsa_priv.h" + +/* This tag length is 4 bytes, older ones were 6 bytes, we do not + * handle them + */ +#define BRCM_TAG_LEN 4 + +/* Tag is constructed and desconstructed using byte by byte access + * because the tag is placed after the MAC Source Address, which does + * not make it 4-bytes aligned, so this might cause unaligned accesses + * on most systems where this is used. + */ + +/* Ingress and egress opcodes */ +#define BRCM_OPCODE_SHIFT 5 +#define BRCM_OPCODE_MASK 0x7 + +/* Ingress fields */ +/* 1st byte in the tag */ +#define BRCM_IG_TC_SHIFT 2 +#define BRCM_IG_TC_MASK 0x7 +/* 2nd byte in the tag */ +#define BRCM_IG_TE_MASK 0x3 +#define BRCM_IG_TS_SHIFT 7 +/* 3rd byte in the tag */ +#define BRCM_IG_DSTMAP2_MASK 1 +#define BRCM_IG_DSTMAP1_MASK 0xff + +/* Egress fields */ + +/* 2nd byte in the tag */ +#define BRCM_EG_CID_MASK 0xff + +/* 3rd byte in the tag */ +#define BRCM_EG_RC_MASK 0xff +#define BRCM_EG_RC_RSVD (3 << 6) +#define BRCM_EG_RC_EXCEPTION (1 << 5) +#define BRCM_EG_RC_PROT_SNOOP (1 << 4) +#define BRCM_EG_RC_PROT_TERM (1 << 3) +#define BRCM_EG_RC_SWITCH (1 << 2) +#define BRCM_EG_RC_MAC_LEARN (1 << 1) +#define BRCM_EG_RC_MIRROR (1 << 0) +#define BRCM_EG_TC_SHIFT 5 +#define BRCM_EG_TC_MASK 0x7 +#define BRCM_EG_PID_MASK 0x1f + +static netdev_tx_t brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct dsa_slave_priv *p = netdev_priv(dev); + u8 *brcm_tag; + + dev->stats.tx_packets++; + dev->stats.tx_bytes += skb->len; + + if (skb_cow_head(skb, BRCM_TAG_LEN) < 0) + goto out_free; + + skb_push(skb, BRCM_TAG_LEN); + + memmove(skb->data, skb->data + BRCM_TAG_LEN, 2 * ETH_ALEN); + + /* Build the tag after the MAC Source Address */ + brcm_tag = skb->data + 2 * ETH_ALEN; + + /* Set the ingress opcode, traffic class, tag enforcment is + * deprecated + */ + brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) | + ((skb->priority << BRCM_IG_TC_SHIFT) & BRCM_IG_TC_MASK); + brcm_tag[1] = 0; + brcm_tag[2] = 0; + if (p->port == 8) + brcm_tag[2] = BRCM_IG_DSTMAP2_MASK; + brcm_tag[3] = (1 << p->port) & BRCM_IG_DSTMAP1_MASK; + + /* Queue the SKB for transmission on the parent interface, but + * do not modify its EtherType + */ + skb->protocol = htons(ETH_P_BRCMTAG); + skb->dev = p->parent->dst->master_netdev; + dev_queue_xmit(skb); + + return NETDEV_TX_OK; + +out_free: + kfree_skb(skb); + return NETDEV_TX_OK; +} + +static int brcm_tag_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; + int source_port; + u8 *brcm_tag; + + if (unlikely(dst == NULL)) + goto out_drop; + + ds = dst->ds[0]; + + skb = skb_unshare(skb, GFP_ATOMIC); + if (skb == NULL) + goto out; + + if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN))) + goto out_drop; + + /* skb->data points to the EtherType, the tag is right before it */ + brcm_tag = skb->data - 2; + + /* The opcode should never be different than 0b000 */ + if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK)) + goto out_drop; + + /* We should never see a reserved reason code without knowing how to + * handle it + */ + WARN_ON(brcm_tag[2] & BRCM_EG_RC_RSVD); + + /* Locate which port this is coming from */ + source_port = brcm_tag[3] & BRCM_EG_PID_MASK; + + /* Validate port against switch setup, either the port is totally */ + if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL) + goto out_drop; + + /* Remove Broadcom tag and update checksum */ + skb_pull_rcsum(skb, BRCM_TAG_LEN); + + /* Move the Ethernet DA and SA */ + memmove(skb->data - ETH_HLEN, + skb->data - ETH_HLEN - BRCM_TAG_LEN, + 2 * ETH_ALEN); + + skb_push(skb, ETH_HLEN); + skb->pkt_type = PACKET_HOST; + skb->dev = ds->ports[source_port]; + skb->protocol = eth_type_trans(skb, skb->dev); + + skb->dev->stats.rx_packets++; + skb->dev->stats.rx_bytes += skb->len; + + netif_receive_skb(skb); + + return 0; + +out_drop: + kfree_skb(skb); +out: + return 0; +} + +const struct dsa_device_ops brcm_netdev_ops = { + .xmit = brcm_tag_xmit, + .rcv = brcm_tag_rcv, +}; |