1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Broadcom tag support 4 * 5 * Copyright (C) 2014 Broadcom Corporation 6 */ 7 8 #include <linux/dsa/brcm.h> 9 #include <linux/etherdevice.h> 10 #include <linux/if_vlan.h> 11 #include <linux/list.h> 12 #include <linux/slab.h> 13 14 #include "tag.h" 15 16 #define BRCM_NAME "brcm" 17 #define BRCM_LEGACY_NAME "brcm-legacy" 18 #define BRCM_PREPEND_NAME "brcm-prepend" 19 20 /* Legacy Broadcom tag (6 bytes) */ 21 #define BRCM_LEG_TAG_LEN 6 22 23 /* Type fields */ 24 /* 1st byte in the tag */ 25 #define BRCM_LEG_TYPE_HI 0x88 26 /* 2nd byte in the tag */ 27 #define BRCM_LEG_TYPE_LO 0x74 28 29 /* Tag fields */ 30 /* 3rd byte in the tag */ 31 #define BRCM_LEG_UNICAST (0 << 5) 32 #define BRCM_LEG_MULTICAST (1 << 5) 33 #define BRCM_LEG_EGRESS (2 << 5) 34 #define BRCM_LEG_INGRESS (3 << 5) 35 36 /* 6th byte in the tag */ 37 #define BRCM_LEG_PORT_ID (0xf) 38 39 /* Newer Broadcom tag (4 bytes) */ 40 #define BRCM_TAG_LEN 4 41 42 /* Tag is constructed and deconstructed using byte by byte access 43 * because the tag is placed after the MAC Source Address, which does 44 * not make it 4-bytes aligned, so this might cause unaligned accesses 45 * on most systems where this is used. 46 */ 47 48 /* Ingress and egress opcodes */ 49 #define BRCM_OPCODE_SHIFT 5 50 #define BRCM_OPCODE_MASK 0x7 51 52 /* Ingress fields */ 53 /* 1st byte in the tag */ 54 #define BRCM_IG_TC_SHIFT 2 55 #define BRCM_IG_TC_MASK 0x7 56 /* 2nd byte in the tag */ 57 #define BRCM_IG_TE_MASK 0x3 58 #define BRCM_IG_TS_SHIFT 7 59 /* 3rd byte in the tag */ 60 #define BRCM_IG_DSTMAP2_MASK 1 61 #define BRCM_IG_DSTMAP1_MASK 0xff 62 63 /* Egress fields */ 64 65 /* 2nd byte in the tag */ 66 #define BRCM_EG_CID_MASK 0xff 67 68 /* 3rd byte in the tag */ 69 #define BRCM_EG_RC_MASK 0xff 70 #define BRCM_EG_RC_RSVD (3 << 6) 71 #define BRCM_EG_RC_EXCEPTION (1 << 5) 72 #define BRCM_EG_RC_PROT_SNOOP (1 << 4) 73 #define BRCM_EG_RC_PROT_TERM (1 << 3) 74 #define BRCM_EG_RC_SWITCH (1 << 2) 75 #define BRCM_EG_RC_MAC_LEARN (1 << 1) 76 #define BRCM_EG_RC_MIRROR (1 << 0) 77 #define BRCM_EG_TC_SHIFT 5 78 #define BRCM_EG_TC_MASK 0x7 79 #define BRCM_EG_PID_MASK 0x1f 80 81 #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) || \ 82 IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) 83 84 static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, 85 struct net_device *dev, 86 unsigned int offset) 87 { 88 struct dsa_port *dp = dsa_slave_to_port(dev); 89 u16 queue = skb_get_queue_mapping(skb); 90 u8 *brcm_tag; 91 92 /* The Ethernet switch we are interfaced with needs packets to be at 93 * least 64 bytes (including FCS) otherwise they will be discarded when 94 * they enter the switch port logic. When Broadcom tags are enabled, we 95 * need to make sure that packets are at least 68 bytes 96 * (including FCS and tag) because the length verification is done after 97 * the Broadcom tag is stripped off the ingress packet. 98 * 99 * Let dsa_slave_xmit() free the SKB 100 */ 101 if (__skb_put_padto(skb, ETH_ZLEN + BRCM_TAG_LEN, false)) 102 return NULL; 103 104 skb_push(skb, BRCM_TAG_LEN); 105 106 if (offset) 107 dsa_alloc_etype_header(skb, BRCM_TAG_LEN); 108 109 brcm_tag = skb->data + offset; 110 111 /* Set the ingress opcode, traffic class, tag enforcement is 112 * deprecated 113 */ 114 brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) | 115 ((queue & BRCM_IG_TC_MASK) << BRCM_IG_TC_SHIFT); 116 brcm_tag[1] = 0; 117 brcm_tag[2] = 0; 118 if (dp->index == 8) 119 brcm_tag[2] = BRCM_IG_DSTMAP2_MASK; 120 brcm_tag[3] = (1 << dp->index) & BRCM_IG_DSTMAP1_MASK; 121 122 /* Now tell the master network device about the desired output queue 123 * as well 124 */ 125 skb_set_queue_mapping(skb, BRCM_TAG_SET_PORT_QUEUE(dp->index, queue)); 126 127 return skb; 128 } 129 130 /* Frames with this tag have one of these two layouts: 131 * ----------------------------------- 132 * | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM 133 * ----------------------------------- 134 * ----------------------------------- 135 * | 4b tag | MAC DA | MAC SA | Type | DSA_TAG_PROTO_BRCM_PREPEND 136 * ----------------------------------- 137 * In both cases, at receive time, skb->data points 2 bytes before the actual 138 * Ethernet type field and we have an offset of 4bytes between where skb->data 139 * and where the payload starts. So the same low-level receive function can be 140 * used. 141 */ 142 static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, 143 struct net_device *dev, 144 unsigned int offset) 145 { 146 int source_port; 147 u8 *brcm_tag; 148 149 if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN))) 150 return NULL; 151 152 brcm_tag = skb->data - offset; 153 154 /* The opcode should never be different than 0b000 */ 155 if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK)) 156 return NULL; 157 158 /* We should never see a reserved reason code without knowing how to 159 * handle it 160 */ 161 if (unlikely(brcm_tag[2] & BRCM_EG_RC_RSVD)) 162 return NULL; 163 164 /* Locate which port this is coming from */ 165 source_port = brcm_tag[3] & BRCM_EG_PID_MASK; 166 167 skb->dev = dsa_master_find_slave(dev, 0, source_port); 168 if (!skb->dev) 169 return NULL; 170 171 /* Remove Broadcom tag and update checksum */ 172 skb_pull_rcsum(skb, BRCM_TAG_LEN); 173 174 dsa_default_offload_fwd_mark(skb); 175 176 return skb; 177 } 178 #endif 179 180 #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) 181 static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, 182 struct net_device *dev) 183 { 184 /* Build the tag after the MAC Source Address */ 185 return brcm_tag_xmit_ll(skb, dev, 2 * ETH_ALEN); 186 } 187 188 189 static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev) 190 { 191 struct sk_buff *nskb; 192 193 /* skb->data points to the EtherType, the tag is right before it */ 194 nskb = brcm_tag_rcv_ll(skb, dev, 2); 195 if (!nskb) 196 return nskb; 197 198 dsa_strip_etype_header(skb, BRCM_TAG_LEN); 199 200 return nskb; 201 } 202 203 static const struct dsa_device_ops brcm_netdev_ops = { 204 .name = BRCM_NAME, 205 .proto = DSA_TAG_PROTO_BRCM, 206 .xmit = brcm_tag_xmit, 207 .rcv = brcm_tag_rcv, 208 .needed_headroom = BRCM_TAG_LEN, 209 }; 210 211 DSA_TAG_DRIVER(brcm_netdev_ops); 212 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM, BRCM_NAME); 213 #endif 214 215 #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY) 216 static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb, 217 struct net_device *dev) 218 { 219 struct dsa_port *dp = dsa_slave_to_port(dev); 220 u8 *brcm_tag; 221 222 /* The Ethernet switch we are interfaced with needs packets to be at 223 * least 64 bytes (including FCS) otherwise they will be discarded when 224 * they enter the switch port logic. When Broadcom tags are enabled, we 225 * need to make sure that packets are at least 70 bytes 226 * (including FCS and tag) because the length verification is done after 227 * the Broadcom tag is stripped off the ingress packet. 228 * 229 * Let dsa_slave_xmit() free the SKB 230 */ 231 if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false)) 232 return NULL; 233 234 skb_push(skb, BRCM_LEG_TAG_LEN); 235 236 dsa_alloc_etype_header(skb, BRCM_LEG_TAG_LEN); 237 238 brcm_tag = skb->data + 2 * ETH_ALEN; 239 240 /* Broadcom tag type */ 241 brcm_tag[0] = BRCM_LEG_TYPE_HI; 242 brcm_tag[1] = BRCM_LEG_TYPE_LO; 243 244 /* Broadcom tag value */ 245 brcm_tag[2] = BRCM_LEG_EGRESS; 246 brcm_tag[3] = 0; 247 brcm_tag[4] = 0; 248 brcm_tag[5] = dp->index & BRCM_LEG_PORT_ID; 249 250 return skb; 251 } 252 253 static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb, 254 struct net_device *dev) 255 { 256 int len = BRCM_LEG_TAG_LEN; 257 int source_port; 258 u8 *brcm_tag; 259 260 if (unlikely(!pskb_may_pull(skb, BRCM_LEG_PORT_ID))) 261 return NULL; 262 263 brcm_tag = dsa_etype_header_pos_rx(skb); 264 265 source_port = brcm_tag[5] & BRCM_LEG_PORT_ID; 266 267 skb->dev = dsa_master_find_slave(dev, 0, source_port); 268 if (!skb->dev) 269 return NULL; 270 271 /* VLAN tag is added by BCM63xx internal switch */ 272 if (netdev_uses_dsa(skb->dev)) 273 len += VLAN_HLEN; 274 275 /* Remove Broadcom tag and update checksum */ 276 skb_pull_rcsum(skb, len); 277 278 dsa_default_offload_fwd_mark(skb); 279 280 dsa_strip_etype_header(skb, len); 281 282 return skb; 283 } 284 285 static const struct dsa_device_ops brcm_legacy_netdev_ops = { 286 .name = BRCM_LEGACY_NAME, 287 .proto = DSA_TAG_PROTO_BRCM_LEGACY, 288 .xmit = brcm_leg_tag_xmit, 289 .rcv = brcm_leg_tag_rcv, 290 .needed_headroom = BRCM_LEG_TAG_LEN, 291 }; 292 293 DSA_TAG_DRIVER(brcm_legacy_netdev_ops); 294 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY, BRCM_LEGACY_NAME); 295 #endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */ 296 297 #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) 298 static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb, 299 struct net_device *dev) 300 { 301 /* tag is prepended to the packet */ 302 return brcm_tag_xmit_ll(skb, dev, 0); 303 } 304 305 static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb, 306 struct net_device *dev) 307 { 308 /* tag is prepended to the packet */ 309 return brcm_tag_rcv_ll(skb, dev, ETH_HLEN); 310 } 311 312 static const struct dsa_device_ops brcm_prepend_netdev_ops = { 313 .name = BRCM_PREPEND_NAME, 314 .proto = DSA_TAG_PROTO_BRCM_PREPEND, 315 .xmit = brcm_tag_xmit_prepend, 316 .rcv = brcm_tag_rcv_prepend, 317 .needed_headroom = BRCM_TAG_LEN, 318 }; 319 320 DSA_TAG_DRIVER(brcm_prepend_netdev_ops); 321 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_PREPEND, BRCM_PREPEND_NAME); 322 #endif 323 324 static struct dsa_tag_driver *dsa_tag_driver_array[] = { 325 #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) 326 &DSA_TAG_DRIVER_NAME(brcm_netdev_ops), 327 #endif 328 #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY) 329 &DSA_TAG_DRIVER_NAME(brcm_legacy_netdev_ops), 330 #endif 331 #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) 332 &DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops), 333 #endif 334 }; 335 336 module_dsa_tag_drivers(dsa_tag_driver_array); 337 338 MODULE_LICENSE("GPL"); 339