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 __be16 *phdr; 35 u16 hdr; 36 37 if (skb_cow_head(skb, QCA_HDR_LEN) < 0) 38 return NULL; 39 40 skb_push(skb, QCA_HDR_LEN); 41 42 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN); 43 phdr = (__be16 *)(skb->data + 2 * ETH_ALEN); 44 45 /* Set the version field, and set destination port information */ 46 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S | 47 QCA_HDR_XMIT_FROM_CPU | BIT(dp->index); 48 49 *phdr = htons(hdr); 50 51 return skb; 52 } 53 54 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev, 55 struct packet_type *pt) 56 { 57 u8 ver; 58 u16 hdr; 59 int port; 60 __be16 *phdr; 61 62 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN))) 63 return NULL; 64 65 /* The QCA header is added by the switch between src addr and Ethertype 66 * At this point, skb->data points to ethertype so header should be 67 * right before 68 */ 69 phdr = (__be16 *)(skb->data - 2); 70 hdr = ntohs(*phdr); 71 72 /* Make sure the version is correct */ 73 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S; 74 if (unlikely(ver != QCA_HDR_VERSION)) 75 return NULL; 76 77 /* Remove QCA tag and recalculate checksum */ 78 skb_pull_rcsum(skb, QCA_HDR_LEN); 79 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN, 80 ETH_HLEN - QCA_HDR_LEN); 81 82 /* Get source port information */ 83 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK); 84 85 skb->dev = dsa_master_find_slave(dev, 0, port); 86 if (!skb->dev) 87 return NULL; 88 89 return skb; 90 } 91 92 static const struct dsa_device_ops qca_netdev_ops = { 93 .name = "qca", 94 .proto = DSA_TAG_PROTO_QCA, 95 .xmit = qca_tag_xmit, 96 .rcv = qca_tag_rcv, 97 .overhead = QCA_HDR_LEN, 98 }; 99 100 MODULE_LICENSE("GPL"); 101 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA); 102 103 module_dsa_tag_driver(qca_netdev_ops); 104