164 lines
4.0 KiB
C
164 lines
4.0 KiB
C
/*
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* Broadcom tag support
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*
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* Copyright (C) 2014 Broadcom Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/etherdevice.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include "dsa_priv.h"
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/* This tag length is 4 bytes, older ones were 6 bytes, we do not
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* handle them
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*/
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#define BRCM_TAG_LEN 4
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/* Tag is constructed and desconstructed using byte by byte access
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* because the tag is placed after the MAC Source Address, which does
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* not make it 4-bytes aligned, so this might cause unaligned accesses
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* on most systems where this is used.
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*/
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/* Ingress and egress opcodes */
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#define BRCM_OPCODE_SHIFT 5
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#define BRCM_OPCODE_MASK 0x7
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/* Ingress fields */
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/* 1st byte in the tag */
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#define BRCM_IG_TC_SHIFT 2
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#define BRCM_IG_TC_MASK 0x7
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/* 2nd byte in the tag */
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#define BRCM_IG_TE_MASK 0x3
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#define BRCM_IG_TS_SHIFT 7
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/* 3rd byte in the tag */
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#define BRCM_IG_DSTMAP2_MASK 1
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#define BRCM_IG_DSTMAP1_MASK 0xff
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/* Egress fields */
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/* 2nd byte in the tag */
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#define BRCM_EG_CID_MASK 0xff
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/* 3rd byte in the tag */
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#define BRCM_EG_RC_MASK 0xff
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#define BRCM_EG_RC_RSVD (3 << 6)
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#define BRCM_EG_RC_EXCEPTION (1 << 5)
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#define BRCM_EG_RC_PROT_SNOOP (1 << 4)
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#define BRCM_EG_RC_PROT_TERM (1 << 3)
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#define BRCM_EG_RC_SWITCH (1 << 2)
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#define BRCM_EG_RC_MAC_LEARN (1 << 1)
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#define BRCM_EG_RC_MIRROR (1 << 0)
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#define BRCM_EG_TC_SHIFT 5
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#define BRCM_EG_TC_MASK 0x7
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#define BRCM_EG_PID_MASK 0x1f
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static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct dsa_slave_priv *p = netdev_priv(dev);
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u8 *brcm_tag;
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if (skb_cow_head(skb, BRCM_TAG_LEN) < 0)
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goto out_free;
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skb_push(skb, BRCM_TAG_LEN);
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memmove(skb->data, skb->data + BRCM_TAG_LEN, 2 * ETH_ALEN);
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/* Build the tag after the MAC Source Address */
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brcm_tag = skb->data + 2 * ETH_ALEN;
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/* Set the ingress opcode, traffic class, tag enforcment is
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* deprecated
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*/
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brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |
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((skb->priority << BRCM_IG_TC_SHIFT) & BRCM_IG_TC_MASK);
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brcm_tag[1] = 0;
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brcm_tag[2] = 0;
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if (p->dp->index == 8)
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brcm_tag[2] = BRCM_IG_DSTMAP2_MASK;
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brcm_tag[3] = (1 << p->dp->index) & BRCM_IG_DSTMAP1_MASK;
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return skb;
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out_free:
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kfree_skb(skb);
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return NULL;
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}
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static int brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
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struct packet_type *pt, struct net_device *orig_dev)
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{
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struct dsa_switch_tree *dst = dev->dsa_ptr;
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struct dsa_switch *ds;
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int source_port;
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u8 *brcm_tag;
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if (unlikely(dst == NULL))
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goto out_drop;
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ds = dst->cpu_switch;
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skb = skb_unshare(skb, GFP_ATOMIC);
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if (skb == NULL)
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goto out;
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if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN)))
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goto out_drop;
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/* skb->data points to the EtherType, the tag is right before it */
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brcm_tag = skb->data - 2;
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/* The opcode should never be different than 0b000 */
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if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK))
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goto out_drop;
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/* We should never see a reserved reason code without knowing how to
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* handle it
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*/
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if (unlikely(brcm_tag[2] & BRCM_EG_RC_RSVD))
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goto out_drop;
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/* Locate which port this is coming from */
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source_port = brcm_tag[3] & BRCM_EG_PID_MASK;
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/* Validate port against switch setup, either the port is totally */
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if (source_port >= ds->num_ports || !ds->ports[source_port].netdev)
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goto out_drop;
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/* Remove Broadcom tag and update checksum */
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skb_pull_rcsum(skb, BRCM_TAG_LEN);
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/* Move the Ethernet DA and SA */
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memmove(skb->data - ETH_HLEN,
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skb->data - ETH_HLEN - BRCM_TAG_LEN,
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2 * ETH_ALEN);
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skb_push(skb, ETH_HLEN);
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skb->pkt_type = PACKET_HOST;
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skb->dev = ds->ports[source_port].netdev;
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skb->protocol = eth_type_trans(skb, skb->dev);
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skb->dev->stats.rx_packets++;
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skb->dev->stats.rx_bytes += skb->len;
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netif_receive_skb(skb);
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return 0;
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out_drop:
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kfree_skb(skb);
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out:
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return 0;
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}
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const struct dsa_device_ops brcm_netdev_ops = {
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.xmit = brcm_tag_xmit,
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.rcv = brcm_tag_rcv,
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};
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