1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling 4 * Copyright (c) 2017 Microchip Technology 5 */ 6 7 #include <linux/etherdevice.h> 8 #include <linux/list.h> 9 #include <net/dsa.h> 10 #include "dsa_priv.h" 11 12 /* Typically only one byte is used for tail tag. */ 13 #define KSZ_EGRESS_TAG_LEN 1 14 #define KSZ_INGRESS_TAG_LEN 1 15 16 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb, 17 struct net_device *dev, 18 unsigned int port, unsigned int len) 19 { 20 skb->dev = dsa_master_find_slave(dev, 0, port); 21 if (!skb->dev) 22 return NULL; 23 24 pskb_trim_rcsum(skb, skb->len - len); 25 26 dsa_default_offload_fwd_mark(skb); 27 28 return skb; 29 } 30 31 /* 32 * For Ingress (Host -> KSZ8795), 1 byte is added before FCS. 33 * --------------------------------------------------------------------------- 34 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes) 35 * --------------------------------------------------------------------------- 36 * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5) 37 * 38 * For Egress (KSZ8795 -> Host), 1 byte is added before FCS. 39 * --------------------------------------------------------------------------- 40 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes) 41 * --------------------------------------------------------------------------- 42 * tag0 : zero-based value represents port 43 * (eg, 0x00=port1, 0x02=port3, 0x06=port7) 44 */ 45 46 #define KSZ8795_TAIL_TAG_OVERRIDE BIT(6) 47 #define KSZ8795_TAIL_TAG_LOOKUP BIT(7) 48 49 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev) 50 { 51 struct dsa_port *dp = dsa_slave_to_port(dev); 52 u8 *tag; 53 u8 *addr; 54 55 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) 56 return NULL; 57 58 /* Tag encoding */ 59 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN); 60 addr = skb_mac_header(skb); 61 62 *tag = 1 << dp->index; 63 if (is_link_local_ether_addr(addr)) 64 *tag |= KSZ8795_TAIL_TAG_OVERRIDE; 65 66 return skb; 67 } 68 69 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev) 70 { 71 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; 72 73 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN); 74 } 75 76 static const struct dsa_device_ops ksz8795_netdev_ops = { 77 .name = "ksz8795", 78 .proto = DSA_TAG_PROTO_KSZ8795, 79 .xmit = ksz8795_xmit, 80 .rcv = ksz8795_rcv, 81 .needed_tailroom = KSZ_INGRESS_TAG_LEN, 82 }; 83 84 DSA_TAG_DRIVER(ksz8795_netdev_ops); 85 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795); 86 87 /* 88 * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS. 89 * --------------------------------------------------------------------------- 90 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes) 91 * --------------------------------------------------------------------------- 92 * tag0 : Prioritization (not used now) 93 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5) 94 * 95 * For Egress (KSZ9477 -> Host), 1 byte is added before FCS. 96 * --------------------------------------------------------------------------- 97 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes) 98 * --------------------------------------------------------------------------- 99 * tag0 : zero-based value represents port 100 * (eg, 0x00=port1, 0x02=port3, 0x06=port7) 101 */ 102 103 #define KSZ9477_INGRESS_TAG_LEN 2 104 #define KSZ9477_PTP_TAG_LEN 4 105 #define KSZ9477_PTP_TAG_INDICATION 0x80 106 107 #define KSZ9477_TAIL_TAG_OVERRIDE BIT(9) 108 #define KSZ9477_TAIL_TAG_LOOKUP BIT(10) 109 110 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb, 111 struct net_device *dev) 112 { 113 struct dsa_port *dp = dsa_slave_to_port(dev); 114 __be16 *tag; 115 u8 *addr; 116 u16 val; 117 118 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) 119 return NULL; 120 121 /* Tag encoding */ 122 tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN); 123 addr = skb_mac_header(skb); 124 125 val = BIT(dp->index); 126 127 if (is_link_local_ether_addr(addr)) 128 val |= KSZ9477_TAIL_TAG_OVERRIDE; 129 130 *tag = cpu_to_be16(val); 131 132 return skb; 133 } 134 135 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev) 136 { 137 /* Tag decoding */ 138 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; 139 unsigned int port = tag[0] & 7; 140 unsigned int len = KSZ_EGRESS_TAG_LEN; 141 142 /* Extra 4-bytes PTP timestamp */ 143 if (tag[0] & KSZ9477_PTP_TAG_INDICATION) 144 len += KSZ9477_PTP_TAG_LEN; 145 146 return ksz_common_rcv(skb, dev, port, len); 147 } 148 149 static const struct dsa_device_ops ksz9477_netdev_ops = { 150 .name = "ksz9477", 151 .proto = DSA_TAG_PROTO_KSZ9477, 152 .xmit = ksz9477_xmit, 153 .rcv = ksz9477_rcv, 154 .needed_tailroom = KSZ9477_INGRESS_TAG_LEN, 155 }; 156 157 DSA_TAG_DRIVER(ksz9477_netdev_ops); 158 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477); 159 160 #define KSZ9893_TAIL_TAG_OVERRIDE BIT(5) 161 #define KSZ9893_TAIL_TAG_LOOKUP BIT(6) 162 163 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb, 164 struct net_device *dev) 165 { 166 struct dsa_port *dp = dsa_slave_to_port(dev); 167 u8 *addr; 168 u8 *tag; 169 170 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) 171 return NULL; 172 173 /* Tag encoding */ 174 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN); 175 addr = skb_mac_header(skb); 176 177 *tag = BIT(dp->index); 178 179 if (is_link_local_ether_addr(addr)) 180 *tag |= KSZ9893_TAIL_TAG_OVERRIDE; 181 182 return skb; 183 } 184 185 static const struct dsa_device_ops ksz9893_netdev_ops = { 186 .name = "ksz9893", 187 .proto = DSA_TAG_PROTO_KSZ9893, 188 .xmit = ksz9893_xmit, 189 .rcv = ksz9477_rcv, 190 .needed_tailroom = KSZ_INGRESS_TAG_LEN, 191 }; 192 193 DSA_TAG_DRIVER(ksz9893_netdev_ops); 194 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893); 195 196 static struct dsa_tag_driver *dsa_tag_driver_array[] = { 197 &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops), 198 &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops), 199 &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops), 200 }; 201 202 module_dsa_tag_drivers(dsa_tag_driver_array); 203 204 MODULE_LICENSE("GPL"); 205