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 if (skb_cow_head(skb, 0) < 0) 37 return NULL; 38 39 skb_push(skb, QCA_HDR_LEN); 40 41 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN); 42 phdr = (u16 *)(skb->data + 2 * ETH_ALEN); 43 44 /* Set the version field, and set destination port information */ 45 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S | 46 QCA_HDR_XMIT_FROM_CPU | BIT(dp->index); 47 48 *phdr = htons(hdr); 49 50 return skb; 51 } 52 53 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev, 54 struct packet_type *pt) 55 { 56 u8 ver; 57 int port; 58 __be16 *phdr, hdr; 59 60 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN))) 61 return NULL; 62 63 /* The QCA header is added by the switch between src addr and Ethertype 64 * At this point, skb->data points to ethertype so header should be 65 * right before 66 */ 67 phdr = (__be16 *)(skb->data - 2); 68 hdr = ntohs(*phdr); 69 70 /* Make sure the version is correct */ 71 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S; 72 if (unlikely(ver != QCA_HDR_VERSION)) 73 return NULL; 74 75 /* Remove QCA tag and recalculate checksum */ 76 skb_pull_rcsum(skb, QCA_HDR_LEN); 77 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN, 78 ETH_HLEN - QCA_HDR_LEN); 79 80 /* Get source port information */ 81 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK); 82 83 skb->dev = dsa_master_find_slave(dev, 0, port); 84 if (!skb->dev) 85 return NULL; 86 87 return skb; 88 } 89 90 static int qca_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto, 91 int *offset) 92 { 93 *offset = QCA_HDR_LEN; 94 *proto = ((__be16 *)skb->data)[0]; 95 96 return 0; 97 } 98 99 static const struct dsa_device_ops qca_netdev_ops = { 100 .name = "qca", 101 .proto = DSA_TAG_PROTO_QCA, 102 .xmit = qca_tag_xmit, 103 .rcv = qca_tag_rcv, 104 .flow_dissect = qca_tag_flow_dissect, 105 .overhead = QCA_HDR_LEN, 106 }; 107 108 MODULE_LICENSE("GPL"); 109 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA); 110 111 module_dsa_tag_driver(qca_netdev_ops); 112