// SPDX-License-Identifier: GPL-2.0+ /* * Broadcom tag support * * Copyright (C) 2014 Broadcom Corporation */ #include #include #include #include #include "dsa_priv.h" /* Legacy Broadcom tag (6 bytes) */ #define BRCM_LEG_TAG_LEN 6 /* Type fields */ /* 1st byte in the tag */ #define BRCM_LEG_TYPE_HI 0x88 /* 2nd byte in the tag */ #define BRCM_LEG_TYPE_LO 0x74 /* Tag fields */ /* 3rd byte in the tag */ #define BRCM_LEG_UNICAST (0 << 5) #define BRCM_LEG_MULTICAST (1 << 5) #define BRCM_LEG_EGRESS (2 << 5) #define BRCM_LEG_INGRESS (3 << 5) /* 6th byte in the tag */ #define BRCM_LEG_PORT_ID (0xf) /* Newer Broadcom tag (4 bytes) */ #define BRCM_TAG_LEN 4 /* Tag is constructed and deconstructed using byte by byte access * because the tag is placed after the MAC Source Address, which does * not make it 4-bytes aligned, so this might cause unaligned accesses * on most systems where this is used. */ /* Ingress and egress opcodes */ #define BRCM_OPCODE_SHIFT 5 #define BRCM_OPCODE_MASK 0x7 /* Ingress fields */ /* 1st byte in the tag */ #define BRCM_IG_TC_SHIFT 2 #define BRCM_IG_TC_MASK 0x7 /* 2nd byte in the tag */ #define BRCM_IG_TE_MASK 0x3 #define BRCM_IG_TS_SHIFT 7 /* 3rd byte in the tag */ #define BRCM_IG_DSTMAP2_MASK 1 #define BRCM_IG_DSTMAP1_MASK 0xff /* Egress fields */ /* 2nd byte in the tag */ #define BRCM_EG_CID_MASK 0xff /* 3rd byte in the tag */ #define BRCM_EG_RC_MASK 0xff #define BRCM_EG_RC_RSVD (3 << 6) #define BRCM_EG_RC_EXCEPTION (1 << 5) #define BRCM_EG_RC_PROT_SNOOP (1 << 4) #define BRCM_EG_RC_PROT_TERM (1 << 3) #define BRCM_EG_RC_SWITCH (1 << 2) #define BRCM_EG_RC_MAC_LEARN (1 << 1) #define BRCM_EG_RC_MIRROR (1 << 0) #define BRCM_EG_TC_SHIFT 5 #define BRCM_EG_TC_MASK 0x7 #define BRCM_EG_PID_MASK 0x1f #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) || \ IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, struct net_device *dev, unsigned int offset) { struct dsa_port *dp = dsa_slave_to_port(dev); u16 queue = skb_get_queue_mapping(skb); u8 *brcm_tag; /* The Ethernet switch we are interfaced with needs packets to be at * least 64 bytes (including FCS) otherwise they will be discarded when * they enter the switch port logic. When Broadcom tags are enabled, we * need to make sure that packets are at least 68 bytes * (including FCS and tag) because the length verification is done after * the Broadcom tag is stripped off the ingress packet. * * Let dsa_slave_xmit() free the SKB */ if (__skb_put_padto(skb, ETH_ZLEN + BRCM_TAG_LEN, false)) return NULL; skb_push(skb, BRCM_TAG_LEN); if (offset) dsa_alloc_etype_header(skb, BRCM_TAG_LEN); brcm_tag = skb->data + offset; /* Set the ingress opcode, traffic class, tag enforcement is * deprecated */ brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) | ((queue & BRCM_IG_TC_MASK) << BRCM_IG_TC_SHIFT); brcm_tag[1] = 0; brcm_tag[2] = 0; if (dp->index == 8) brcm_tag[2] = BRCM_IG_DSTMAP2_MASK; brcm_tag[3] = (1 << dp->index) & BRCM_IG_DSTMAP1_MASK; /* Now tell the master network device about the desired output queue * as well */ skb_set_queue_mapping(skb, BRCM_TAG_SET_PORT_QUEUE(dp->index, queue)); return skb; } /* Frames with this tag have one of these two layouts: * ----------------------------------- * | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM * ----------------------------------- * ----------------------------------- * | 4b tag | MAC DA | MAC SA | Type | DSA_TAG_PROTO_BRCM_PREPEND * ----------------------------------- * In both cases, at receive time, skb->data points 2 bytes before the actual * Ethernet type field and we have an offset of 4bytes between where skb->data * and where the payload starts. So the same low-level receive function can be * used. */ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, struct net_device *dev, unsigned int offset) { int source_port; u8 *brcm_tag; if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN))) return NULL; brcm_tag = skb->data - offset; /* The opcode should never be different than 0b000 */ if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK)) return NULL; /* We should never see a reserved reason code without knowing how to * handle it */ if (unlikely(brcm_tag[2] & BRCM_EG_RC_RSVD)) return NULL; /* Locate which port this is coming from */ source_port = brcm_tag[3] & BRCM_EG_PID_MASK; skb->dev = dsa_master_find_slave(dev, 0, source_port); if (!skb->dev) return NULL; /* Remove Broadcom tag and update checksum */ skb_pull_rcsum(skb, BRCM_TAG_LEN); dsa_default_offload_fwd_mark(skb); return skb; } #endif #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev) { /* Build the tag after the MAC Source Address */ return brcm_tag_xmit_ll(skb, dev, 2 * ETH_ALEN); } static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev) { struct sk_buff *nskb; /* skb->data points to the EtherType, the tag is right before it */ nskb = brcm_tag_rcv_ll(skb, dev, 2); if (!nskb) return nskb; dsa_strip_etype_header(skb, BRCM_TAG_LEN); return nskb; } static const struct dsa_device_ops brcm_netdev_ops = { .name = "brcm", .proto = DSA_TAG_PROTO_BRCM, .xmit = brcm_tag_xmit, .rcv = brcm_tag_rcv, .needed_headroom = BRCM_TAG_LEN, }; DSA_TAG_DRIVER(brcm_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM); #endif #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY) static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); u8 *brcm_tag; /* The Ethernet switch we are interfaced with needs packets to be at * least 64 bytes (including FCS) otherwise they will be discarded when * they enter the switch port logic. When Broadcom tags are enabled, we * need to make sure that packets are at least 70 bytes * (including FCS and tag) because the length verification is done after * the Broadcom tag is stripped off the ingress packet. * * Let dsa_slave_xmit() free the SKB */ if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false)) return NULL; skb_push(skb, BRCM_LEG_TAG_LEN); dsa_alloc_etype_header(skb, BRCM_LEG_TAG_LEN); brcm_tag = skb->data + 2 * ETH_ALEN; /* Broadcom tag type */ brcm_tag[0] = BRCM_LEG_TYPE_HI; brcm_tag[1] = BRCM_LEG_TYPE_LO; /* Broadcom tag value */ brcm_tag[2] = BRCM_LEG_EGRESS; brcm_tag[3] = 0; brcm_tag[4] = 0; brcm_tag[5] = dp->index & BRCM_LEG_PORT_ID; return skb; } static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb, struct net_device *dev) { int source_port; u8 *brcm_tag; if (unlikely(!pskb_may_pull(skb, BRCM_LEG_PORT_ID))) return NULL; brcm_tag = dsa_etype_header_pos_rx(skb); source_port = brcm_tag[5] & BRCM_LEG_PORT_ID; skb->dev = dsa_master_find_slave(dev, 0, source_port); if (!skb->dev) return NULL; /* Remove Broadcom tag and update checksum */ skb_pull_rcsum(skb, BRCM_LEG_TAG_LEN); dsa_default_offload_fwd_mark(skb); dsa_strip_etype_header(skb, BRCM_LEG_TAG_LEN); return skb; } static const struct dsa_device_ops brcm_legacy_netdev_ops = { .name = "brcm-legacy", .proto = DSA_TAG_PROTO_BRCM_LEGACY, .xmit = brcm_leg_tag_xmit, .rcv = brcm_leg_tag_rcv, .needed_headroom = BRCM_LEG_TAG_LEN, }; DSA_TAG_DRIVER(brcm_legacy_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY); #endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */ #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb, struct net_device *dev) { /* tag is prepended to the packet */ return brcm_tag_xmit_ll(skb, dev, 0); } static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb, struct net_device *dev) { /* tag is prepended to the packet */ return brcm_tag_rcv_ll(skb, dev, ETH_HLEN); } static const struct dsa_device_ops brcm_prepend_netdev_ops = { .name = "brcm-prepend", .proto = DSA_TAG_PROTO_BRCM_PREPEND, .xmit = brcm_tag_xmit_prepend, .rcv = brcm_tag_rcv_prepend, .needed_headroom = BRCM_TAG_LEN, }; DSA_TAG_DRIVER(brcm_prepend_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_PREPEND); #endif static struct dsa_tag_driver *dsa_tag_driver_array[] = { #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) &DSA_TAG_DRIVER_NAME(brcm_netdev_ops), #endif #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY) &DSA_TAG_DRIVER_NAME(brcm_legacy_netdev_ops), #endif #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) &DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops), #endif }; module_dsa_tag_drivers(dsa_tag_driver_array); MODULE_LICENSE("GPL");