diff options
Diffstat (limited to 'net/dsa/tag_brcm.c')
-rw-r--r-- | net/dsa/tag_brcm.c | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c new file mode 100644 index 000000000..a65d62fb9 --- /dev/null +++ b/net/dsa/tag_brcm.c @@ -0,0 +1,334 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Broadcom tag support + * + * Copyright (C) 2014 Broadcom Corporation + */ + +#include <linux/dsa/brcm.h> +#include <linux/etherdevice.h> +#include <linux/if_vlan.h> +#include <linux/list.h> +#include <linux/slab.h> + +#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 len = BRCM_LEG_TAG_LEN; + 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; + + /* VLAN tag is added by BCM63xx internal switch */ + if (netdev_uses_dsa(skb->dev)) + len += VLAN_HLEN; + + /* Remove Broadcom tag and update checksum */ + skb_pull_rcsum(skb, len); + + dsa_default_offload_fwd_mark(skb); + + dsa_strip_etype_header(skb, 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"); |