1 /* 2 * Copyright (c) 2015, The Linux Foundation. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 and 6 * only version 2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/etherdevice.h> 15 #include <net/dsa.h> 16 #include "dsa_priv.h" 17 18 #define QCA_HDR_LEN 2 19 #define QCA_HDR_VERSION 0x2 20 21 #define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14) 22 #define QCA_HDR_RECV_VERSION_S 14 23 #define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11) 24 #define QCA_HDR_RECV_PRIORITY_S 11 25 #define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6) 26 #define QCA_HDR_RECV_TYPE_S 6 27 #define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3) 28 #define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0) 29 30 #define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14) 31 #define QCA_HDR_XMIT_VERSION_S 14 32 #define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11) 33 #define QCA_HDR_XMIT_PRIORITY_S 11 34 #define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8) 35 #define QCA_HDR_XMIT_CONTROL_S 8 36 #define QCA_HDR_XMIT_FROM_CPU BIT(7) 37 #define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0) 38 39 static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev) 40 { 41 struct dsa_slave_priv *p = netdev_priv(dev); 42 u16 *phdr, hdr; 43 44 dev->stats.tx_packets++; 45 dev->stats.tx_bytes += skb->len; 46 47 if (skb_cow_head(skb, 0) < 0) 48 goto out_free; 49 50 skb_push(skb, QCA_HDR_LEN); 51 52 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN); 53 phdr = (u16 *)(skb->data + 2 * ETH_ALEN); 54 55 /* Set the version field, and set destination port information */ 56 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S | 57 QCA_HDR_XMIT_FROM_CPU | 58 BIT(p->dp->index); 59 60 *phdr = htons(hdr); 61 62 return skb; 63 64 out_free: 65 kfree_skb(skb); 66 return NULL; 67 } 68 69 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev, 70 struct packet_type *pt, 71 struct net_device *orig_dev) 72 { 73 struct dsa_switch_tree *dst = dev->dsa_ptr; 74 struct dsa_switch *ds; 75 u8 ver; 76 int port; 77 __be16 *phdr, hdr; 78 79 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN))) 80 goto out_drop; 81 82 /* The QCA header is added by the switch between src addr and Ethertype 83 * At this point, skb->data points to ethertype so header should be 84 * right before 85 */ 86 phdr = (__be16 *)(skb->data - 2); 87 hdr = ntohs(*phdr); 88 89 /* Make sure the version is correct */ 90 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S; 91 if (unlikely(ver != QCA_HDR_VERSION)) 92 goto out_drop; 93 94 /* Remove QCA tag and recalculate checksum */ 95 skb_pull_rcsum(skb, QCA_HDR_LEN); 96 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN, 97 ETH_HLEN - QCA_HDR_LEN); 98 99 /* This protocol doesn't support cascading multiple switches so it's 100 * safe to assume the switch is first in the tree 101 */ 102 ds = dst->cpu_switch; 103 if (!ds) 104 goto out_drop; 105 106 /* Get source port information */ 107 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK); 108 if (!ds->ports[port].netdev) 109 goto out_drop; 110 111 /* Update skb & forward the frame accordingly */ 112 skb->dev = ds->ports[port].netdev; 113 114 return skb; 115 116 out_drop: 117 return NULL; 118 } 119 120 const struct dsa_device_ops qca_netdev_ops = { 121 .xmit = qca_tag_xmit, 122 .rcv = qca_tag_rcv, 123 }; 124