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v5.14.15
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2017 Pengutronix, Juergen Borleis <jbe@pengutronix.de>
  4 */
  5#include <linux/dsa/lan9303.h>
  6#include <linux/etherdevice.h>
  7#include <linux/list.h>
  8#include <linux/slab.h>
  9
 10#include "dsa_priv.h"
 11
 12/* To define the outgoing port and to discover the incoming port a regular
 13 * VLAN tag is used by the LAN9303. But its VID meaning is 'special':
 14 *
 15 *       Dest MAC       Src MAC        TAG    Type
 16 * ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 | 1 2 |...
 17 *                                |<------->|
 18 * TAG:
 19 *    |<------------->|
 20 *    |  1  2 | 3  4  |
 21 *      TPID    VID
 22 *     0x8100
 23 *
 24 * VID bit 3 indicates a request for an ALR lookup.
 25 *
 26 * If VID bit 3 is zero, then bits 0 and 1 specify the destination port
 27 * (0, 1, 2) or broadcast (3) or the source port (1, 2).
 28 *
 29 * VID bit 4 is used to specify if the STP port state should be overridden.
 30 * Required when no forwarding between the external ports should happen.
 31 */
 32
 
 
 33#define LAN9303_TAG_LEN 4
 34# define LAN9303_TAG_TX_USE_ALR BIT(3)
 35# define LAN9303_TAG_TX_STP_OVERRIDE BIT(4)
 36# define LAN9303_TAG_RX_IGMP BIT(3)
 37# define LAN9303_TAG_RX_STP BIT(4)
 38# define LAN9303_TAG_RX_TRAPPED_TO_CPU (LAN9303_TAG_RX_IGMP | \
 39					LAN9303_TAG_RX_STP)
 40
 41/* Decide whether to transmit using ALR lookup, or transmit directly to
 42 * port using tag. ALR learning is performed only when using ALR lookup.
 43 * If the two external ports are bridged and the frame is unicast,
 44 * then use ALR lookup to allow ALR learning on CPU port.
 45 * Otherwise transmit directly to port with STP state override.
 46 * See also: lan9303_separate_ports() and lan9303.pdf 6.4.10.1
 47 */
 48static int lan9303_xmit_use_arl(struct dsa_port *dp, u8 *dest_addr)
 49{
 50	struct lan9303 *chip = dp->ds->priv;
 51
 52	return chip->is_bridged && !is_multicast_ether_addr(dest_addr);
 53}
 54
 55static struct sk_buff *lan9303_xmit(struct sk_buff *skb, struct net_device *dev)
 56{
 57	struct dsa_port *dp = dsa_slave_to_port(dev);
 58	__be16 *lan9303_tag;
 59	u16 tag;
 60
 61	/* provide 'LAN9303_TAG_LEN' bytes additional space */
 62	skb_push(skb, LAN9303_TAG_LEN);
 63
 64	/* make room between MACs and Ether-Type */
 65	memmove(skb->data, skb->data + LAN9303_TAG_LEN, 2 * ETH_ALEN);
 
 
 66
 67	lan9303_tag = (__be16 *)(skb->data + 2 * ETH_ALEN);
 68	tag = lan9303_xmit_use_arl(dp, skb->data) ?
 69		LAN9303_TAG_TX_USE_ALR :
 70		dp->index | LAN9303_TAG_TX_STP_OVERRIDE;
 71	lan9303_tag[0] = htons(ETH_P_8021Q);
 72	lan9303_tag[1] = htons(tag);
 73
 74	return skb;
 75}
 76
 77static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev,
 78				   struct packet_type *pt)
 79{
 80	__be16 *lan9303_tag;
 81	u16 lan9303_tag1;
 82	unsigned int source_port;
 83
 84	if (unlikely(!pskb_may_pull(skb, LAN9303_TAG_LEN))) {
 85		dev_warn_ratelimited(&dev->dev,
 86				     "Dropping packet, cannot pull\n");
 87		return NULL;
 88	}
 89
 90	/* '->data' points into the middle of our special VLAN tag information:
 91	 *
 92	 * ~ MAC src   | 0x81 | 0x00 | 0xyy | 0xzz | ether type
 93	 *                           ^
 94	 *                        ->data
 95	 */
 96	lan9303_tag = (__be16 *)(skb->data - 2);
 97
 98	if (lan9303_tag[0] != htons(ETH_P_8021Q)) {
 99		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid VLAN marker\n");
100		return NULL;
101	}
102
103	lan9303_tag1 = ntohs(lan9303_tag[1]);
104	source_port = lan9303_tag1 & 0x3;
105
106	skb->dev = dsa_master_find_slave(dev, 0, source_port);
107	if (!skb->dev) {
108		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n");
109		return NULL;
110	}
111
112	/* remove the special VLAN tag between the MAC addresses
113	 * and the current ethertype field.
114	 */
115	skb_pull_rcsum(skb, 2 + 2);
116	memmove(skb->data - ETH_HLEN, skb->data - (ETH_HLEN + LAN9303_TAG_LEN),
117		2 * ETH_ALEN);
118	skb->offload_fwd_mark = !(lan9303_tag1 & LAN9303_TAG_RX_TRAPPED_TO_CPU);
119
120	return skb;
121}
122
123static const struct dsa_device_ops lan9303_netdev_ops = {
124	.name = "lan9303",
125	.proto	= DSA_TAG_PROTO_LAN9303,
126	.xmit = lan9303_xmit,
127	.rcv = lan9303_rcv,
128	.needed_headroom = LAN9303_TAG_LEN,
129};
130
 
131MODULE_LICENSE("GPL");
132MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN9303);
133
134module_dsa_tag_driver(lan9303_netdev_ops);
v6.9.4
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2017 Pengutronix, Juergen Borleis <jbe@pengutronix.de>
  4 */
  5#include <linux/dsa/lan9303.h>
  6#include <linux/etherdevice.h>
  7#include <linux/list.h>
  8#include <linux/slab.h>
  9
 10#include "tag.h"
 11
 12/* To define the outgoing port and to discover the incoming port a regular
 13 * VLAN tag is used by the LAN9303. But its VID meaning is 'special':
 14 *
 15 *       Dest MAC       Src MAC        TAG    Type
 16 * ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 | 1 2 |...
 17 *                                |<------->|
 18 * TAG:
 19 *    |<------------->|
 20 *    |  1  2 | 3  4  |
 21 *      TPID    VID
 22 *     0x8100
 23 *
 24 * VID bit 3 indicates a request for an ALR lookup.
 25 *
 26 * If VID bit 3 is zero, then bits 0 and 1 specify the destination port
 27 * (0, 1, 2) or broadcast (3) or the source port (1, 2).
 28 *
 29 * VID bit 4 is used to specify if the STP port state should be overridden.
 30 * Required when no forwarding between the external ports should happen.
 31 */
 32
 33#define LAN9303_NAME "lan9303"
 34
 35#define LAN9303_TAG_LEN 4
 36# define LAN9303_TAG_TX_USE_ALR BIT(3)
 37# define LAN9303_TAG_TX_STP_OVERRIDE BIT(4)
 38# define LAN9303_TAG_RX_IGMP BIT(3)
 39# define LAN9303_TAG_RX_STP BIT(4)
 40# define LAN9303_TAG_RX_TRAPPED_TO_CPU (LAN9303_TAG_RX_IGMP | \
 41					LAN9303_TAG_RX_STP)
 42
 43/* Decide whether to transmit using ALR lookup, or transmit directly to
 44 * port using tag. ALR learning is performed only when using ALR lookup.
 45 * If the two external ports are bridged and the frame is unicast,
 46 * then use ALR lookup to allow ALR learning on CPU port.
 47 * Otherwise transmit directly to port with STP state override.
 48 * See also: lan9303_separate_ports() and lan9303.pdf 6.4.10.1
 49 */
 50static int lan9303_xmit_use_arl(struct dsa_port *dp, u8 *dest_addr)
 51{
 52	struct lan9303 *chip = dp->ds->priv;
 53
 54	return chip->is_bridged && !is_multicast_ether_addr(dest_addr);
 55}
 56
 57static struct sk_buff *lan9303_xmit(struct sk_buff *skb, struct net_device *dev)
 58{
 59	struct dsa_port *dp = dsa_user_to_port(dev);
 60	__be16 *lan9303_tag;
 61	u16 tag;
 62
 63	/* provide 'LAN9303_TAG_LEN' bytes additional space */
 64	skb_push(skb, LAN9303_TAG_LEN);
 65
 66	/* make room between MACs and Ether-Type */
 67	dsa_alloc_etype_header(skb, LAN9303_TAG_LEN);
 68
 69	lan9303_tag = dsa_etype_header_pos_tx(skb);
 70
 
 71	tag = lan9303_xmit_use_arl(dp, skb->data) ?
 72		LAN9303_TAG_TX_USE_ALR :
 73		dp->index | LAN9303_TAG_TX_STP_OVERRIDE;
 74	lan9303_tag[0] = htons(ETH_P_8021Q);
 75	lan9303_tag[1] = htons(tag);
 76
 77	return skb;
 78}
 79
 80static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev)
 
 81{
 
 82	u16 lan9303_tag1;
 83	unsigned int source_port;
 84
 85	if (unlikely(!pskb_may_pull(skb, LAN9303_TAG_LEN))) {
 86		dev_warn_ratelimited(&dev->dev,
 87				     "Dropping packet, cannot pull\n");
 88		return NULL;
 89	}
 90
 91	if (skb_vlan_tag_present(skb)) {
 92		lan9303_tag1 = skb_vlan_tag_get(skb);
 93		__vlan_hwaccel_clear_tag(skb);
 94	} else {
 95		skb_push_rcsum(skb, ETH_HLEN);
 96		__skb_vlan_pop(skb, &lan9303_tag1);
 97		skb_pull_rcsum(skb, ETH_HLEN);
 
 
 
 
 98	}
 99
 
100	source_port = lan9303_tag1 & 0x3;
101
102	skb->dev = dsa_conduit_find_user(dev, 0, source_port);
103	if (!skb->dev) {
104		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n");
105		return NULL;
106	}
107
108	if (!(lan9303_tag1 & LAN9303_TAG_RX_TRAPPED_TO_CPU))
109		dsa_default_offload_fwd_mark(skb);
 
 
 
 
 
110
111	return skb;
112}
113
114static const struct dsa_device_ops lan9303_netdev_ops = {
115	.name = LAN9303_NAME,
116	.proto	= DSA_TAG_PROTO_LAN9303,
117	.xmit = lan9303_xmit,
118	.rcv = lan9303_rcv,
119	.needed_headroom = LAN9303_TAG_LEN,
120};
121
122MODULE_DESCRIPTION("DSA tag driver for SMSC/Microchip LAN9303 family of switches");
123MODULE_LICENSE("GPL");
124MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN9303, LAN9303_NAME);
125
126module_dsa_tag_driver(lan9303_netdev_ops);