1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2015, The Linux Foundation. All rights reserved. 4 */ 5 6 #include <linux/etherdevice.h> 7 8 #include "dsa_priv.h" 9 10 #define QCA_HDR_LEN 2 11 #define QCA_HDR_VERSION 0x2 12 13 #define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14) 14 #define QCA_HDR_RECV_VERSION_S 14 15 #define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11) 16 #define QCA_HDR_RECV_PRIORITY_S 11 17 #define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6) 18 #define QCA_HDR_RECV_TYPE_S 6 19 #define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3) 20 #define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0) 21 22 #define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14) 23 #define QCA_HDR_XMIT_VERSION_S 14 24 #define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11) 25 #define QCA_HDR_XMIT_PRIORITY_S 11 26 #define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8) 27 #define QCA_HDR_XMIT_CONTROL_S 8 28 #define QCA_HDR_XMIT_FROM_CPU BIT(7) 29 #define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0) 30 31 static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev) 32 { 33 struct dsa_port *dp = dsa_slave_to_port(dev); 34 u16 *phdr, hdr; 35 36 dev->stats.tx_packets++; 37 dev->stats.tx_bytes += skb->len; 38 39 if (skb_cow_head(skb, 0) < 0) 40 return NULL; 41 42 skb_push(skb, QCA_HDR_LEN); 43 44 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN); 45 phdr = (u16 *)(skb->data + 2 * ETH_ALEN); 46 47 /* Set the version field, and set destination port information */ 48 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S | 49 QCA_HDR_XMIT_FROM_CPU | BIT(dp->index); 50 51 *phdr = htons(hdr); 52 53 return skb; 54 } 55 56 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev, 57 struct packet_type *pt) 58 { 59 u8 ver; 60 int port; 61 __be16 *phdr, hdr; 62 63 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN))) 64 return NULL; 65 66 /* The QCA header is added by the switch between src addr and Ethertype 67 * At this point, skb->data points to ethertype so header should be 68 * right before 69 */ 70 phdr = (__be16 *)(skb->data - 2); 71 hdr = ntohs(*phdr); 72 73 /* Make sure the version is correct */ 74 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S; 75 if (unlikely(ver != QCA_HDR_VERSION)) 76 return NULL; 77 78 /* Remove QCA tag and recalculate checksum */ 79 skb_pull_rcsum(skb, QCA_HDR_LEN); 80 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN, 81 ETH_HLEN - QCA_HDR_LEN); 82 83 /* Get source port information */ 84 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK); 85 86 skb->dev = dsa_master_find_slave(dev, 0, port); 87 if (!skb->dev) 88 return NULL; 89 90 return skb; 91 } 92 93 static int qca_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto, 94 int *offset) 95 { 96 *offset = QCA_HDR_LEN; 97 *proto = ((__be16 *)skb->data)[0]; 98 99 return 0; 100 } 101 102 static const struct dsa_device_ops qca_netdev_ops = { 103 .name = "qca", 104 .proto = DSA_TAG_PROTO_QCA, 105 .xmit = qca_tag_xmit, 106 .rcv = qca_tag_rcv, 107 .flow_dissect = qca_tag_flow_dissect, 108 .overhead = QCA_HDR_LEN, 109 }; 110 111 MODULE_LICENSE("GPL"); 112 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA); 113 114 module_dsa_tag_driver(qca_netdev_ops); 115