1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Intel / Lantiq GSWIP V2.0 PMAC tag support 4 * 5 * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de> 6 */ 7 8 #include <linux/bitops.h> 9 #include <linux/etherdevice.h> 10 #include <linux/skbuff.h> 11 #include <net/dsa.h> 12 13 #include "dsa_priv.h" 14 15 #define GSWIP_TX_HEADER_LEN 4 16 17 /* special tag in TX path header */ 18 /* Byte 0 */ 19 #define GSWIP_TX_SLPID_SHIFT 0 /* source port ID */ 20 #define GSWIP_TX_SLPID_CPU 2 21 #define GSWIP_TX_SLPID_APP1 3 22 #define GSWIP_TX_SLPID_APP2 4 23 #define GSWIP_TX_SLPID_APP3 5 24 #define GSWIP_TX_SLPID_APP4 6 25 #define GSWIP_TX_SLPID_APP5 7 26 27 /* Byte 1 */ 28 #define GSWIP_TX_CRCGEN_DIS BIT(7) 29 #define GSWIP_TX_DPID_SHIFT 0 /* destination group ID */ 30 #define GSWIP_TX_DPID_ELAN 0 31 #define GSWIP_TX_DPID_EWAN 1 32 #define GSWIP_TX_DPID_CPU 2 33 #define GSWIP_TX_DPID_APP1 3 34 #define GSWIP_TX_DPID_APP2 4 35 #define GSWIP_TX_DPID_APP3 5 36 #define GSWIP_TX_DPID_APP4 6 37 #define GSWIP_TX_DPID_APP5 7 38 39 /* Byte 2 */ 40 #define GSWIP_TX_PORT_MAP_EN BIT(7) 41 #define GSWIP_TX_PORT_MAP_SEL BIT(6) 42 #define GSWIP_TX_LRN_DIS BIT(5) 43 #define GSWIP_TX_CLASS_EN BIT(4) 44 #define GSWIP_TX_CLASS_SHIFT 0 45 #define GSWIP_TX_CLASS_MASK GENMASK(3, 0) 46 47 /* Byte 3 */ 48 #define GSWIP_TX_DPID_EN BIT(0) 49 #define GSWIP_TX_PORT_MAP_SHIFT 1 50 #define GSWIP_TX_PORT_MAP_MASK GENMASK(6, 1) 51 52 #define GSWIP_RX_HEADER_LEN 8 53 54 /* special tag in RX path header */ 55 /* Byte 7 */ 56 #define GSWIP_RX_SPPID_SHIFT 4 57 #define GSWIP_RX_SPPID_MASK GENMASK(6, 4) 58 59 static struct sk_buff *gswip_tag_xmit(struct sk_buff *skb, 60 struct net_device *dev) 61 { 62 struct dsa_port *dp = dsa_slave_to_port(dev); 63 int err; 64 u8 *gswip_tag; 65 66 err = skb_cow_head(skb, GSWIP_TX_HEADER_LEN); 67 if (err) 68 return NULL; 69 70 skb_push(skb, GSWIP_TX_HEADER_LEN); 71 72 gswip_tag = skb->data; 73 gswip_tag[0] = GSWIP_TX_SLPID_CPU; 74 gswip_tag[1] = GSWIP_TX_DPID_ELAN; 75 gswip_tag[2] = GSWIP_TX_PORT_MAP_EN | GSWIP_TX_PORT_MAP_SEL; 76 gswip_tag[3] = BIT(dp->index + GSWIP_TX_PORT_MAP_SHIFT) & GSWIP_TX_PORT_MAP_MASK; 77 gswip_tag[3] |= GSWIP_TX_DPID_EN; 78 79 return skb; 80 } 81 82 static struct sk_buff *gswip_tag_rcv(struct sk_buff *skb, 83 struct net_device *dev, 84 struct packet_type *pt) 85 { 86 int port; 87 u8 *gswip_tag; 88 89 if (unlikely(!pskb_may_pull(skb, GSWIP_RX_HEADER_LEN))) 90 return NULL; 91 92 gswip_tag = skb->data - ETH_HLEN; 93 94 /* Get source port information */ 95 port = (gswip_tag[7] & GSWIP_RX_SPPID_MASK) >> GSWIP_RX_SPPID_SHIFT; 96 skb->dev = dsa_master_find_slave(dev, 0, port); 97 if (!skb->dev) 98 return NULL; 99 100 /* remove GSWIP tag */ 101 skb_pull_rcsum(skb, GSWIP_RX_HEADER_LEN); 102 103 return skb; 104 } 105 106 static const struct dsa_device_ops gswip_netdev_ops = { 107 .name = "gwsip", 108 .proto = DSA_TAG_PROTO_GSWIP, 109 .xmit = gswip_tag_xmit, 110 .rcv = gswip_tag_rcv, 111 .overhead = GSWIP_RX_HEADER_LEN, 112 }; 113 114 MODULE_LICENSE("GPL"); 115 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_GSWIP); 116 117 module_dsa_tag_driver(gswip_netdev_ops); 118