| /* |
| * 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); |
| u16 queue = skb_get_queue_mapping(skb); |
| u8 *brcm_tag; |
| |
| if (skb_cow_head(skb, BRCM_TAG_LEN) < 0) |
| return NULL; |
| |
| 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) | |
| ((queue & BRCM_IG_TC_MASK) << BRCM_IG_TC_SHIFT); |
| 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; |
| } |
| |
| static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev, |
| struct packet_type *pt) |
| { |
| struct dsa_switch_tree *dst = dev->dsa_ptr; |
| struct dsa_port *cpu_dp = dsa_get_cpu_port(dst); |
| struct dsa_switch *ds = cpu_dp->ds; |
| int source_port; |
| u8 *brcm_tag; |
| |
| if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN))) |
| return NULL; |
| |
| /* 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)) |
| return NULL; |
| |
| /* We should never see a reserved reason code without knowing how to |
| * handle it |
| */ |
| if (unlikely(brcm_tag[2] & BRCM_EG_RC_RSVD)) |
| return NULL; |
| |
| /* 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) |
| return NULL; |
| |
| if (unlikely(ds->cpu_port_mask & BIT(source_port))) |
| return NULL; |
| |
| /* 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; |
| } |
| |
| const struct dsa_device_ops brcm_netdev_ops = { |
| .xmit = brcm_tag_xmit, |
| .rcv = brcm_tag_rcv, |
| }; |