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 "tag.h" 14 15 #define GSWIP_NAME "gswip" 16 17 #define GSWIP_TX_HEADER_LEN 4 18 19 /* special tag in TX path header */ 20 /* Byte 0 */ 21 #define GSWIP_TX_SLPID_SHIFT 0 /* source port ID */ 22 #define GSWIP_TX_SLPID_CPU 2 23 #define GSWIP_TX_SLPID_APP1 3 24 #define GSWIP_TX_SLPID_APP2 4 25 #define GSWIP_TX_SLPID_APP3 5 26 #define GSWIP_TX_SLPID_APP4 6 27 #define GSWIP_TX_SLPID_APP5 7 28 29 /* Byte 1 */ 30 #define GSWIP_TX_CRCGEN_DIS BIT(7) 31 #define GSWIP_TX_DPID_SHIFT 0 /* destination group ID */ 32 #define GSWIP_TX_DPID_ELAN 0 33 #define GSWIP_TX_DPID_EWAN 1 34 #define GSWIP_TX_DPID_CPU 2 35 #define GSWIP_TX_DPID_APP1 3 36 #define GSWIP_TX_DPID_APP2 4 37 #define GSWIP_TX_DPID_APP3 5 38 #define GSWIP_TX_DPID_APP4 6 39 #define GSWIP_TX_DPID_APP5 7 40 41 /* Byte 2 */ 42 #define GSWIP_TX_PORT_MAP_EN BIT(7) 43 #define GSWIP_TX_PORT_MAP_SEL BIT(6) 44 #define GSWIP_TX_LRN_DIS BIT(5) 45 #define GSWIP_TX_CLASS_EN BIT(4) 46 #define GSWIP_TX_CLASS_SHIFT 0 47 #define GSWIP_TX_CLASS_MASK GENMASK(3, 0) 48 49 /* Byte 3 */ 50 #define GSWIP_TX_DPID_EN BIT(0) 51 #define GSWIP_TX_PORT_MAP GENMASK(6, 1) 52 53 #define GSWIP_RX_HEADER_LEN 8 54 55 /* special tag in RX path header */ 56 /* Byte 7 */ 57 #define GSWIP_RX_SPPID_SHIFT 4 58 #define GSWIP_RX_SPPID_MASK GENMASK(6, 4) 59 60 static struct sk_buff *gswip_tag_xmit(struct sk_buff *skb, 61 struct net_device *dev) 62 { 63 u8 *gswip_tag; 64 65 skb_push(skb, GSWIP_TX_HEADER_LEN); 66 67 gswip_tag = skb->data; 68 gswip_tag[0] = GSWIP_TX_SLPID_CPU; 69 gswip_tag[1] = GSWIP_TX_DPID_ELAN; 70 gswip_tag[2] = GSWIP_TX_PORT_MAP_EN | GSWIP_TX_PORT_MAP_SEL; 71 gswip_tag[3] = FIELD_PREP(GSWIP_TX_PORT_MAP, dsa_xmit_port_mask(skb, dev)); 72 gswip_tag[3] |= GSWIP_TX_DPID_EN; 73 74 return skb; 75 } 76 77 static struct sk_buff *gswip_tag_rcv(struct sk_buff *skb, 78 struct net_device *dev) 79 { 80 int port; 81 u8 *gswip_tag; 82 83 if (unlikely(!pskb_may_pull(skb, GSWIP_RX_HEADER_LEN))) 84 return NULL; 85 86 gswip_tag = skb->data - ETH_HLEN; 87 88 /* Get source port information */ 89 port = (gswip_tag[7] & GSWIP_RX_SPPID_MASK) >> GSWIP_RX_SPPID_SHIFT; 90 skb->dev = dsa_conduit_find_user(dev, 0, port); 91 if (!skb->dev) 92 return NULL; 93 94 /* remove GSWIP tag */ 95 skb_pull_rcsum(skb, GSWIP_RX_HEADER_LEN); 96 97 return skb; 98 } 99 100 static const struct dsa_device_ops gswip_netdev_ops = { 101 .name = GSWIP_NAME, 102 .proto = DSA_TAG_PROTO_GSWIP, 103 .xmit = gswip_tag_xmit, 104 .rcv = gswip_tag_rcv, 105 .needed_headroom = GSWIP_RX_HEADER_LEN, 106 }; 107 108 MODULE_DESCRIPTION("DSA tag driver for Lantiq / Intel GSWIP switches"); 109 MODULE_LICENSE("GPL"); 110 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_GSWIP, GSWIP_NAME); 111 112 module_dsa_tag_driver(gswip_netdev_ops); 113