/* * 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 #include #include #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; } static struct sk_buff *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; ds = dst->cpu_dp->ds; 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->dev = ds->ports[source_port].netdev; return skb; out_drop: return NULL; } const struct dsa_device_ops brcm_netdev_ops = { .xmit = brcm_tag_xmit, .rcv = brcm_tag_rcv, };