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Release 4.15 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_ll(struct sk_buff *skb, struct net_device *dev, unsigned int offset) { struct dsa_port *dp = dsa_slave_to_port(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); if (offset) memmove(skb->data, skb->data + BRCM_TAG_LEN, offset); brcm_tag = skb->data + offset; /* 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 (dp->index == 8) brcm_tag[2] = BRCM_IG_DSTMAP2_MASK; brcm_tag[3] = (1 << dp->index) & BRCM_IG_DSTMAP1_MASK; /* Now tell the master network device about the desired output queue * as well */ skb_set_queue_mapping(skb, BRCM_TAG_SET_PORT_QUEUE(dp->index, queue)); return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli16493.18%562.50%
Vivien Didelot126.82%337.50%
Total176100.00%8100.00%


static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, unsigned int offset) { int source_port; u8 *brcm_tag; if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN))) return NULL; brcm_tag = skb->data - offset; /* 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; skb->dev = dsa_master_find_slave(dev, 0, source_port); if (!skb->dev) return NULL; /* Remove Broadcom tag and update checksum */ skb_pull_rcsum(skb, BRCM_TAG_LEN); return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli11079.71%342.86%
Vivien Didelot2719.57%342.86%
Andrew Lunn10.72%114.29%
Total138100.00%7100.00%

#ifdef CONFIG_NET_DSA_TAG_BRCM
static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev) { /* Build the tag after the MAC Source Address */ return brcm_tag_xmit_ll(skb, dev, 2 * ETH_ALEN); }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli31100.00%1100.00%
Total31100.00%1100.00%


static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt) { struct sk_buff *nskb; /* skb->data points to the EtherType, the tag is right before it */ nskb = brcm_tag_rcv_ll(skb, dev, pt, 2); if (!nskb) return nskb; /* Move the Ethernet DA and SA */ memmove(nskb->data - ETH_HLEN, nskb->data - ETH_HLEN - BRCM_TAG_LEN, 2 * ETH_ALEN); return nskb; }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli75100.00%2100.00%
Total75100.00%2100.00%

const struct dsa_device_ops brcm_netdev_ops = { .xmit = brcm_tag_xmit, .rcv = brcm_tag_rcv, }; #endif #ifdef CONFIG_NET_DSA_TAG_BRCM_PREPEND
static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb, struct net_device *dev) { /* tag is prepended to the packet */ return brcm_tag_xmit_ll(skb, dev, 0); }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli29100.00%1100.00%
Total29100.00%1100.00%


static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt) { /* tag is prepended to the packet */ return brcm_tag_rcv_ll(skb, dev, pt, ETH_HLEN); }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli36100.00%1100.00%
Total36100.00%1100.00%

const struct dsa_device_ops brcm_prepend_netdev_ops = { .xmit = brcm_tag_xmit_prepend, .rcv = brcm_tag_rcv_prepend, }; #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli59693.71%750.00%
Vivien Didelot396.13%642.86%
Andrew Lunn10.16%17.14%
Total636100.00%14100.00%
Directory: net/dsa
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