cregit-Linux how code gets into the kernel

Release 4.14 net/dsa/tag_ksz.c

Directory: net/dsa
/*
 * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
 * Copyright (c) 2017 Microchip Technology
 *
 * 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 <net/dsa.h>
#include "dsa_priv.h"

/* For Ingress (Host -> KSZ), 2 bytes are added before FCS.
 * ---------------------------------------------------------------------------
 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
 * ---------------------------------------------------------------------------
 * tag0 : Prioritization (not used now)
 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
 *
 * For Egress (KSZ -> Host), 1 byte is added before FCS.
 * ---------------------------------------------------------------------------
 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
 * ---------------------------------------------------------------------------
 * tag0 : zero-based value represents port
 *        (eg, 0x00=port1, 0x02=port3, 0x06=port7)
 */


#define	KSZ_INGRESS_TAG_LEN	2

#define	KSZ_EGRESS_TAG_LEN	1


static struct sk_buff *ksz_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_slave_priv *p = netdev_priv(dev); struct sk_buff *nskb; int padlen; u8 *tag; padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len; if (skb_tailroom(skb) >= padlen + KSZ_INGRESS_TAG_LEN) { /* Let dsa_slave_xmit() free skb */ if (__skb_put_padto(skb, skb->len + padlen, false)) return NULL; nskb = skb; } else { nskb = alloc_skb(NET_IP_ALIGN + skb->len + padlen + KSZ_INGRESS_TAG_LEN, GFP_ATOMIC); if (!nskb) return NULL; skb_reserve(nskb, NET_IP_ALIGN); skb_reset_mac_header(nskb); skb_set_network_header(nskb, skb_network_header(skb) - skb->head); skb_set_transport_header(nskb, skb_transport_header(skb) - skb->head); skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len)); /* Let skb_put_padto() free nskb, and let dsa_slave_xmit() free * skb */ if (skb_put_padto(nskb, nskb->len + padlen)) return NULL; consume_skb(skb); } tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN); tag[0] = 0; tag[1] = 1 << p->dp->index; /* destination port */ return nskb; }

Contributors

PersonTokensPropCommitsCommitProp
Woojung Huh20588.74%125.00%
Vivien Didelot208.66%125.00%
Florian Fainelli52.16%125.00%
Eric Dumazet10.43%125.00%
Total231100.00%4100.00%


static struct sk_buff *ksz_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; u8 *tag; int source_port; tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; source_port = tag[0] & 7; if (source_port >= ds->num_ports || !ds->ports[source_port].netdev) return NULL; pskb_trim_rcsum(skb, skb->len - KSZ_EGRESS_TAG_LEN); skb->dev = ds->ports[source_port].netdev; return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Woojung Huh10987.90%133.33%
Florian Fainelli1411.29%133.33%
Colin Ian King10.81%133.33%
Total124100.00%3100.00%

const struct dsa_device_ops ksz_netdev_ops = { .xmit = ksz_xmit, .rcv = ksz_rcv, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Woojung Huh35689.67%116.67%
Vivien Didelot205.04%116.67%
Florian Fainelli194.79%233.33%
Colin Ian King10.25%116.67%
Eric Dumazet10.25%116.67%
Total397100.00%6100.00%
Directory: net/dsa
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