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Release 4.11 net/dsa/tag_brcm.c

Directory: net/dsa
/*
 * 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/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 struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_slave_priv *p = netdev_priv(dev); u8 *brcm_tag; 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->dp->index == 8) brcm_tag[2] = BRCM_IG_DSTMAP2_MASK; brcm_tag[3] = (1 << p->dp->index) & BRCM_IG_DSTMAP1_MASK; return skb; out_free: kfree_skb(skb); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli16096.39%266.67%
Vivien Didelot63.61%133.33%
Total166100.00%3100.00%


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->cpu_switch; 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 */ if (unlikely(brcm_tag[2] & BRCM_EG_RC_RSVD)) goto out_drop; /* 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 >= ds->num_ports || !ds->ports[source_port].netdev) 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].netdev; 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; }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli27796.85%240.00%
Andrew Lunn51.75%120.00%
Vivien Didelot41.40%240.00%
Total286100.00%5100.00%

const struct dsa_device_ops brcm_netdev_ops = { .xmit = brcm_tag_xmit, .rcv = brcm_tag_rcv, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli56197.40%342.86%
Vivien Didelot101.74%342.86%
Andrew Lunn50.87%114.29%
Total576100.00%7100.00%
Directory: net/dsa
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