--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2019 NXP Semiconductors
+ */
+#include <soc/mscc/ocelot.h>
+#include <linux/packing.h>
+#include "dsa_priv.h"
+
+/* The CPU injection header and the CPU extraction header can have 3 types of
+ * prefixes: long, short and no prefix. The format of the header itself is the
+ * same in all 3 cases.
+ *
+ * Extraction with long prefix:
+ *
+ * +-------------------+-------------------+------+------+------------+-------+
+ * | ff:ff:ff:ff:ff:ff | ff:ff:ff:ff:ff:ff | 8880 | 000a | extraction | frame |
+ * | | | | | header | |
+ * +-------------------+-------------------+------+------+------------+-------+
+ * 48 bits 48 bits 16 bits 16 bits 128 bits
+ *
+ * Extraction with short prefix:
+ *
+ * +------+------+------------+-------+
+ * | 8880 | 000a | extraction | frame |
+ * | | | header | |
+ * +------+------+------------+-------+
+ * 16 bits 16 bits 128 bits
+ *
+ * Extraction with no prefix:
+ *
+ * +------------+-------+
+ * | extraction | frame |
+ * | header | |
+ * +------------+-------+
+ * 128 bits
+ *
+ *
+ * Injection with long prefix:
+ *
+ * +-------------------+-------------------+------+------+------------+-------+
+ * | any dmac | any smac | 8880 | 000a | injection | frame |
+ * | | | | | header | |
+ * +-------------------+-------------------+------+------+------------+-------+
+ * 48 bits 48 bits 16 bits 16 bits 128 bits
+ *
+ * Injection with short prefix:
+ *
+ * +------+------+------------+-------+
+ * | 8880 | 000a | injection | frame |
+ * | | | header | |
+ * +------+------+------------+-------+
+ * 16 bits 16 bits 128 bits
+ *
+ * Injection with no prefix:
+ *
+ * +------------+-------+
+ * | injection | frame |
+ * | header | |
+ * +------------+-------+
+ * 128 bits
+ *
+ * The injection header looks like this (network byte order, bit 127
+ * is part of lowest address byte in memory, bit 0 is part of highest
+ * address byte):
+ *
+ * +------+------+------+------+------+------+------+------+
+ * 127:120 |BYPASS| MASQ | MASQ_PORT |REW_OP|REW_OP|
+ * +------+------+------+------+------+------+------+------+
+ * 119:112 | REW_OP |
+ * +------+------+------+------+------+------+------+------+
+ * 111:104 | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 103: 96 | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 95: 88 | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 87: 80 | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 79: 72 | RSV |
+ * +------+------+------+------+------+------+------+------+
+ * 71: 64 | RSV | DEST |
+ * +------+------+------+------+------+------+------+------+
+ * 63: 56 | DEST |
+ * +------+------+------+------+------+------+------+------+
+ * 55: 48 | RSV |
+ * +------+------+------+------+------+------+------+------+
+ * 47: 40 | RSV | SRC_PORT | RSV |TFRM_TIMER|
+ * +------+------+------+------+------+------+------+------+
+ * 39: 32 | TFRM_TIMER | RSV |
+ * +------+------+------+------+------+------+------+------+
+ * 31: 24 | RSV | DP | POP_CNT | CPUQ |
+ * +------+------+------+------+------+------+------+------+
+ * 23: 16 | CPUQ | QOS_CLASS |TAG_TYPE|
+ * +------+------+------+------+------+------+------+------+
+ * 15: 8 | PCP | DEI | VID |
+ * +------+------+------+------+------+------+------+------+
+ * 7: 0 | VID |
+ * +------+------+------+------+------+------+------+------+
+ *
+ * And the extraction header looks like this:
+ *
+ * +------+------+------+------+------+------+------+------+
+ * 127:120 | RSV | REW_OP |
+ * +------+------+------+------+------+------+------+------+
+ * 119:112 | REW_OP | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 111:104 | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 103: 96 | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 95: 88 | REW_VAL |
+ * +------+------+------+------+------+------+------+------+
+ * 87: 80 | REW_VAL | LLEN |
+ * +------+------+------+------+------+------+------+------+
+ * 79: 72 | LLEN | WLEN |
+ * +------+------+------+------+------+------+------+------+
+ * 71: 64 | WLEN | RSV |
+ * +------+------+------+------+------+------+------+------+
+ * 63: 56 | RSV |
+ * +------+------+------+------+------+------+------+------+
+ * 55: 48 | RSV |
+ * +------+------+------+------+------+------+------+------+
+ * 47: 40 | RSV | SRC_PORT | ACL_ID |
+ * +------+------+------+------+------+------+------+------+
+ * 39: 32 | ACL_ID | RSV | SFLOW_ID |
+ * +------+------+------+------+------+------+------+------+
+ * 31: 24 |ACL_HIT| DP | LRN_FLAGS | CPUQ |
+ * +------+------+------+------+------+------+------+------+
+ * 23: 16 | CPUQ | QOS_CLASS |TAG_TYPE|
+ * +------+------+------+------+------+------+------+------+
+ * 15: 8 | PCP | DEI | VID |
+ * +------+------+------+------+------+------+------+------+
+ * 7: 0 | VID |
+ * +------+------+------+------+------+------+------+------+
+ */
+
+static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
+ struct net_device *netdev)
+{
+ struct dsa_port *dp = dsa_slave_to_port(netdev);
+ u64 bypass, dest, src, qos_class;
+ struct dsa_switch *ds = dp->ds;
+ int port = dp->index;
+ u8 *injection;
+
+ if (unlikely(skb_cow_head(skb, OCELOT_TAG_LEN) < 0)) {
+ netdev_err(netdev, "Cannot make room for tag.\n");
+ return NULL;
+ }
+
+ injection = skb_push(skb, OCELOT_TAG_LEN);
+
+ memset(injection, 0, OCELOT_TAG_LEN);
+
+ src = dsa_upstream_port(ds, port);
+ dest = BIT(port);
+ bypass = true;
+ qos_class = skb->priority;
+
+ packing(injection, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0);
+ packing(injection, &dest, 68, 56, OCELOT_TAG_LEN, PACK, 0);
+ packing(injection, &src, 46, 43, OCELOT_TAG_LEN, PACK, 0);
+ packing(injection, &qos_class, 19, 17, OCELOT_TAG_LEN, PACK, 0);
+
+ return skb;
+}
+
+static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
+ struct net_device *netdev,
+ struct packet_type *pt)
+{
+ u64 src_port, qos_class;
+ u8 *start = skb->data;
+ u8 *extraction;
+
+ /* Revert skb->data by the amount consumed by the DSA master,
+ * so it points to the beginning of the frame.
+ */
+ skb_push(skb, ETH_HLEN);
+ /* We don't care about the long prefix, it is just for easy entrance
+ * into the DSA master's RX filter. Discard it now by moving it into
+ * the headroom.
+ */
+ skb_pull(skb, OCELOT_LONG_PREFIX_LEN);
+ /* And skb->data now points to the extraction frame header.
+ * Keep a pointer to it.
+ */
+ extraction = skb->data;
+ /* Now the EFH is part of the headroom as well */
+ skb_pull(skb, OCELOT_TAG_LEN);
+ /* Reset the pointer to the real MAC header */
+ skb_reset_mac_header(skb);
+ skb_reset_mac_len(skb);
+ /* And move skb->data to the correct location again */
+ skb_pull(skb, ETH_HLEN);
+
+ /* Remove from inet csum the extraction header */
+ skb_postpull_rcsum(skb, start, OCELOT_LONG_PREFIX_LEN + OCELOT_TAG_LEN);
+
+ packing(extraction, &src_port, 46, 43, OCELOT_TAG_LEN, UNPACK, 0);
+ packing(extraction, &qos_class, 19, 17, OCELOT_TAG_LEN, UNPACK, 0);
+
+ skb->dev = dsa_master_find_slave(netdev, 0, src_port);
+ if (!skb->dev)
+ /* The switch will reflect back some frames sent through
+ * sockets opened on the bare DSA master. These will come back
+ * with src_port equal to the index of the CPU port, for which
+ * there is no slave registered. So don't print any error
+ * message here (ignore and drop those frames).
+ */
+ return NULL;
+
+ skb->offload_fwd_mark = 1;
+ skb->priority = qos_class;
+
+ return skb;
+}
+
+static struct dsa_device_ops ocelot_netdev_ops = {
+ .name = "ocelot",
+ .proto = DSA_TAG_PROTO_OCELOT,
+ .xmit = ocelot_xmit,
+ .rcv = ocelot_rcv,
+ .overhead = OCELOT_TAG_LEN + OCELOT_LONG_PREFIX_LEN,
+};
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT);
+
+module_dsa_tag_driver(ocelot_netdev_ops);