diff options
Diffstat (limited to 'net/dsa/tag_brcm.c')
| -rw-r--r-- | net/dsa/tag_brcm.c | 147 |
1 files changed, 125 insertions, 22 deletions
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c index 9c3114179690..16889ea3e0a7 100644 --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -5,18 +5,36 @@ * Copyright (C) 2014 Broadcom Corporation */ +#include <linux/dsa/brcm.h> #include <linux/etherdevice.h> #include <linux/list.h> #include <linux/slab.h> #include "dsa_priv.h" -/* This tag length is 4 bytes, older ones were 6 bytes, we do not - * handle them - */ +/* 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 desconstructed using byte by byte access +/* 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. @@ -66,9 +84,6 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, u16 queue = skb_get_queue_mapping(skb); u8 *brcm_tag; - if (skb_cow_head(skb, BRCM_TAG_LEN) < 0) - return NULL; - /* 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 @@ -84,11 +99,11 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, skb_push(skb, BRCM_TAG_LEN); if (offset) - memmove(skb->data, skb->data + BRCM_TAG_LEN, offset); + dsa_alloc_etype_header(skb, BRCM_TAG_LEN); brcm_tag = skb->data + offset; - /* Set the ingress opcode, traffic class, tag enforcment is + /* Set the ingress opcode, traffic class, tag enforcement is * deprecated */ brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) | @@ -107,9 +122,20 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, 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, - struct packet_type *pt, unsigned int offset) { int source_port; @@ -140,6 +166,8 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, /* Remove Broadcom tag and update checksum */ skb_pull_rcsum(skb, BRCM_TAG_LEN); + dsa_default_offload_fwd_mark(skb); + return skb; } #endif @@ -153,20 +181,16 @@ static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, } -static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev, - struct packet_type *pt) +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, pt, 2); + nskb = brcm_tag_rcv_ll(skb, dev, 2); if (!nskb) return nskb; - /* Move the Ethernet DA and SA */ - memmove(nskb->data - ETH_HLEN, - nskb->data - ETH_HLEN - BRCM_TAG_LEN, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, BRCM_TAG_LEN); return nskb; } @@ -176,13 +200,90 @@ static const struct dsa_device_ops brcm_netdev_ops = { .proto = DSA_TAG_PROTO_BRCM, .xmit = brcm_tag_xmit, .rcv = brcm_tag_rcv, - .overhead = BRCM_TAG_LEN, + .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) @@ -192,11 +293,10 @@ static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb, } static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb, - struct net_device *dev, - struct packet_type *pt) + struct net_device *dev) { /* tag is prepended to the packet */ - return brcm_tag_rcv_ll(skb, dev, pt, ETH_HLEN); + return brcm_tag_rcv_ll(skb, dev, ETH_HLEN); } static const struct dsa_device_ops brcm_prepend_netdev_ops = { @@ -204,7 +304,7 @@ static const struct dsa_device_ops brcm_prepend_netdev_ops = { .proto = DSA_TAG_PROTO_BRCM_PREPEND, .xmit = brcm_tag_xmit_prepend, .rcv = brcm_tag_rcv_prepend, - .overhead = BRCM_TAG_LEN, + .needed_headroom = BRCM_TAG_LEN, }; DSA_TAG_DRIVER(brcm_prepend_netdev_ops); @@ -215,6 +315,9 @@ 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 |