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 <linux/slab.h> 10 #include <net/dsa.h> 11 #include "dsa_priv.h" 12 13 /* Typically only one byte is used for tail tag. */ 14 #define KSZ_EGRESS_TAG_LEN 1 15 #define KSZ_INGRESS_TAG_LEN 1 16 17 static struct sk_buff *ksz_common_xmit(struct sk_buff *skb, 18 struct net_device *dev, int len) 19 { 20 struct sk_buff *nskb; 21 int padlen; 22 23 padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len; 24 25 if (skb_tailroom(skb) >= padlen + len) { 26 /* Let dsa_slave_xmit() free skb */ 27 if (__skb_put_padto(skb, skb->len + padlen, false)) 28 return NULL; 29 30 nskb = skb; 31 } else { 32 nskb = alloc_skb(NET_IP_ALIGN + skb->len + 33 padlen + len, GFP_ATOMIC); 34 if (!nskb) 35 return NULL; 36 skb_reserve(nskb, NET_IP_ALIGN); 37 38 skb_reset_mac_header(nskb); 39 skb_set_network_header(nskb, 40 skb_network_header(skb) - skb->head); 41 skb_set_transport_header(nskb, 42 skb_transport_header(skb) - skb->head); 43 skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len)); 44 45 /* Let skb_put_padto() free nskb, and let dsa_slave_xmit() free 46 * skb 47 */ 48 if (skb_put_padto(nskb, nskb->len + padlen)) 49 return NULL; 50 51 consume_skb(skb); 52 } 53 54 return nskb; 55 } 56 57 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb, 58 struct net_device *dev, 59 unsigned int port, unsigned int len) 60 { 61 skb->dev = dsa_master_find_slave(dev, 0, port); 62 if (!skb->dev) 63 return NULL; 64 65 pskb_trim_rcsum(skb, skb->len - len); 66 67 skb->offload_fwd_mark = true; 68 69 return skb; 70 } 71 72 /* 73 * For Ingress (Host -> KSZ8795), 1 byte is added before FCS. 74 * --------------------------------------------------------------------------- 75 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes) 76 * --------------------------------------------------------------------------- 77 * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5) 78 * 79 * For Egress (KSZ8795 -> Host), 1 byte is added before FCS. 80 * --------------------------------------------------------------------------- 81 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes) 82 * --------------------------------------------------------------------------- 83 * tag0 : zero-based value represents port 84 * (eg, 0x00=port1, 0x02=port3, 0x06=port7) 85 */ 86 87 #define KSZ8795_TAIL_TAG_OVERRIDE BIT(6) 88 #define KSZ8795_TAIL_TAG_LOOKUP BIT(7) 89 90 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev) 91 { 92 struct dsa_port *dp = dsa_slave_to_port(dev); 93 struct sk_buff *nskb; 94 u8 *tag; 95 u8 *addr; 96 97 nskb = ksz_common_xmit(skb, dev, KSZ_INGRESS_TAG_LEN); 98 if (!nskb) 99 return NULL; 100 101 /* Tag encoding */ 102 tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN); 103 addr = skb_mac_header(nskb); 104 105 *tag = 1 << dp->index; 106 if (is_link_local_ether_addr(addr)) 107 *tag |= KSZ8795_TAIL_TAG_OVERRIDE; 108 109 return nskb; 110 } 111 112 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev, 113 struct packet_type *pt) 114 { 115 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; 116 117 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN); 118 } 119 120 static const struct dsa_device_ops ksz8795_netdev_ops = { 121 .name = "ksz8795", 122 .proto = DSA_TAG_PROTO_KSZ8795, 123 .xmit = ksz8795_xmit, 124 .rcv = ksz8795_rcv, 125 .overhead = KSZ_INGRESS_TAG_LEN, 126 .tail_tag = true, 127 }; 128 129 DSA_TAG_DRIVER(ksz8795_netdev_ops); 130 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795); 131 132 /* 133 * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS. 134 * --------------------------------------------------------------------------- 135 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes) 136 * --------------------------------------------------------------------------- 137 * tag0 : Prioritization (not used now) 138 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5) 139 * 140 * For Egress (KSZ9477 -> Host), 1 byte is added before FCS. 141 * --------------------------------------------------------------------------- 142 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes) 143 * --------------------------------------------------------------------------- 144 * tag0 : zero-based value represents port 145 * (eg, 0x00=port1, 0x02=port3, 0x06=port7) 146 */ 147 148 #define KSZ9477_INGRESS_TAG_LEN 2 149 #define KSZ9477_PTP_TAG_LEN 4 150 #define KSZ9477_PTP_TAG_INDICATION 0x80 151 152 #define KSZ9477_TAIL_TAG_OVERRIDE BIT(9) 153 #define KSZ9477_TAIL_TAG_LOOKUP BIT(10) 154 155 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb, 156 struct net_device *dev) 157 { 158 struct dsa_port *dp = dsa_slave_to_port(dev); 159 struct sk_buff *nskb; 160 __be16 *tag; 161 u8 *addr; 162 u16 val; 163 164 nskb = ksz_common_xmit(skb, dev, KSZ9477_INGRESS_TAG_LEN); 165 if (!nskb) 166 return NULL; 167 168 /* Tag encoding */ 169 tag = skb_put(nskb, KSZ9477_INGRESS_TAG_LEN); 170 addr = skb_mac_header(nskb); 171 172 val = BIT(dp->index); 173 174 if (is_link_local_ether_addr(addr)) 175 val |= KSZ9477_TAIL_TAG_OVERRIDE; 176 177 *tag = cpu_to_be16(val); 178 179 return nskb; 180 } 181 182 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev, 183 struct packet_type *pt) 184 { 185 /* Tag decoding */ 186 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; 187 unsigned int port = tag[0] & 7; 188 unsigned int len = KSZ_EGRESS_TAG_LEN; 189 190 /* Extra 4-bytes PTP timestamp */ 191 if (tag[0] & KSZ9477_PTP_TAG_INDICATION) 192 len += KSZ9477_PTP_TAG_LEN; 193 194 return ksz_common_rcv(skb, dev, port, len); 195 } 196 197 static const struct dsa_device_ops ksz9477_netdev_ops = { 198 .name = "ksz9477", 199 .proto = DSA_TAG_PROTO_KSZ9477, 200 .xmit = ksz9477_xmit, 201 .rcv = ksz9477_rcv, 202 .overhead = KSZ9477_INGRESS_TAG_LEN, 203 .tail_tag = true, 204 }; 205 206 DSA_TAG_DRIVER(ksz9477_netdev_ops); 207 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477); 208 209 #define KSZ9893_TAIL_TAG_OVERRIDE BIT(5) 210 #define KSZ9893_TAIL_TAG_LOOKUP BIT(6) 211 212 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb, 213 struct net_device *dev) 214 { 215 struct dsa_port *dp = dsa_slave_to_port(dev); 216 struct sk_buff *nskb; 217 u8 *addr; 218 u8 *tag; 219 220 nskb = ksz_common_xmit(skb, dev, KSZ_INGRESS_TAG_LEN); 221 if (!nskb) 222 return NULL; 223 224 /* Tag encoding */ 225 tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN); 226 addr = skb_mac_header(nskb); 227 228 *tag = BIT(dp->index); 229 230 if (is_link_local_ether_addr(addr)) 231 *tag |= KSZ9893_TAIL_TAG_OVERRIDE; 232 233 return nskb; 234 } 235 236 static const struct dsa_device_ops ksz9893_netdev_ops = { 237 .name = "ksz9893", 238 .proto = DSA_TAG_PROTO_KSZ9893, 239 .xmit = ksz9893_xmit, 240 .rcv = ksz9477_rcv, 241 .overhead = KSZ_INGRESS_TAG_LEN, 242 .tail_tag = true, 243 }; 244 245 DSA_TAG_DRIVER(ksz9893_netdev_ops); 246 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893); 247 248 static struct dsa_tag_driver *dsa_tag_driver_array[] = { 249 &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops), 250 &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops), 251 &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops), 252 }; 253 254 module_dsa_tag_drivers(dsa_tag_driver_array); 255 256 MODULE_LICENSE("GPL"); 257