// SPDX-License-Identifier: GPL-2.0
/* Copyright 2019 NXP
 */
#include <linux/dsa/ocelot.h>

#include "tag.h"

#define OCELOT_NAME     "ocelot"
#define SEVILLE_NAME    "seville"

static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
                               __be32 ifh_prefix, void **ifh)
{
        struct dsa_port *dp = dsa_user_to_port(netdev);
        struct dsa_switch *ds = dp->ds;
        u64 vlan_tci, tag_type;
        void *injection;
        __be32 *prefix;
        u32 rew_op = 0;
        u64 qos_class;

        ocelot_xmit_get_vlan_info(skb, dsa_port_bridge_dev_get(dp), &vlan_tci,
                                  &tag_type);

        qos_class = netdev_get_num_tc(netdev) ?
                    netdev_get_prio_tc_map(netdev, skb->priority) : skb->priority;

        injection = skb_push(skb, OCELOT_TAG_LEN);
        prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);

        *prefix = ifh_prefix;
        memset(injection, 0, OCELOT_TAG_LEN);
        ocelot_ifh_set_bypass(injection, 1);
        ocelot_ifh_set_src(injection, ds->num_ports);
        ocelot_ifh_set_qos_class(injection, qos_class);
        ocelot_ifh_set_vlan_tci(injection, vlan_tci);
        ocelot_ifh_set_tag_type(injection, tag_type);

        rew_op = ocelot_ptp_rew_op(skb);
        if (rew_op)
                ocelot_ifh_set_rew_op(injection, rew_op);

        *ifh = injection;
}

static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
                                   struct net_device *netdev)
{
        void *injection;

        ocelot_xmit_common(skb, netdev, cpu_to_be32(0x8880000a), &injection);
        ocelot_ifh_set_dest(injection, dsa_xmit_port_mask(skb, netdev));

        return skb;
}

static struct sk_buff *seville_xmit(struct sk_buff *skb,
                                    struct net_device *netdev)
{
        void *injection;

        ocelot_xmit_common(skb, netdev, cpu_to_be32(0x88800005), &injection);
        seville_ifh_set_dest(injection, dsa_xmit_port_mask(skb, netdev));

        return skb;
}

static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
                                  struct net_device *netdev)
{
        u64 src_port, qos_class;
        u64 vlan_tci, tag_type;
        u8 *start = skb->data;
        struct dsa_port *dp;
        u8 *extraction;
        u16 vlan_tpid;
        u64 rew_val;

        /* Revert skb->data by the amount consumed by the DSA conduit,
         * so it points to the beginning of the frame.
         */
        skb_push(skb, ETH_HLEN);
        /* We don't care about the short prefix, it is just for easy entrance
         * into the DSA conduit's RX filter. Discard it now by moving it into
         * the headroom.
         */
        skb_pull(skb, OCELOT_SHORT_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_TOTAL_TAG_LEN);

        ocelot_xfh_get_src_port(extraction, &src_port);
        ocelot_xfh_get_qos_class(extraction, &qos_class);
        ocelot_xfh_get_tag_type(extraction, &tag_type);
        ocelot_xfh_get_vlan_tci(extraction, &vlan_tci);
        ocelot_xfh_get_rew_val(extraction, &rew_val);

        skb->dev = dsa_conduit_find_user(netdev, 0, src_port);
        if (!skb->dev) {
                /* The switch will reflect back some frames sent through
                 * sockets opened on the bare DSA conduit. These will come back
                 * with src_port equal to the index of the CPU port, for which
                 * there is no user registered. So don't print any error
                 * message here (ignore and drop those frames).
                 */
                kfree_skb(skb);
                return NULL;
        }

        dsa_default_offload_fwd_mark(skb);
        skb->priority = qos_class;
        OCELOT_SKB_CB(skb)->tstamp_lo = rew_val;

        /* Ocelot switches copy frames unmodified to the CPU. However, it is
         * possible for the user to request a VLAN modification through
         * VCAP_IS1_ACT_VID_REPLACE_ENA. In this case, what will happen is that
         * the VLAN ID field from the Extraction Header gets updated, but the
         * 802.1Q header does not (the classified VLAN only becomes visible on
         * egress through the "port tag" of front-panel ports).
         * So, for traffic extracted by the CPU, we want to pick up the
         * classified VLAN and manually replace the existing 802.1Q header from
         * the packet with it, so that the operating system is always up to
         * date with the result of tc-vlan actions.
         * NOTE: In VLAN-unaware mode, we don't want to do that, we want the
         * frame to remain unmodified, because the classified VLAN is always
         * equal to the pvid of the ingress port and should not be used for
         * processing.
         */
        dp = dsa_user_to_port(skb->dev);
        vlan_tpid = tag_type ? ETH_P_8021AD : ETH_P_8021Q;

        if (dsa_port_is_vlan_filtering(dp) &&
            eth_hdr(skb)->h_proto == htons(vlan_tpid)) {
                u16 dummy_vlan_tci;

                skb_push_rcsum(skb, ETH_HLEN);
                __skb_vlan_pop(skb, &dummy_vlan_tci);
                skb_pull_rcsum(skb, ETH_HLEN);
                __vlan_hwaccel_put_tag(skb, htons(vlan_tpid), vlan_tci);
        }

        return skb;
}

static const struct dsa_device_ops ocelot_netdev_ops = {
        .name                   = OCELOT_NAME,
        .proto                  = DSA_TAG_PROTO_OCELOT,
        .xmit                   = ocelot_xmit,
        .rcv                    = ocelot_rcv,
        .needed_headroom        = OCELOT_TOTAL_TAG_LEN,
        .promisc_on_conduit     = true,
};

DSA_TAG_DRIVER(ocelot_netdev_ops);
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT, OCELOT_NAME);

static const struct dsa_device_ops seville_netdev_ops = {
        .name                   = SEVILLE_NAME,
        .proto                  = DSA_TAG_PROTO_SEVILLE,
        .xmit                   = seville_xmit,
        .rcv                    = ocelot_rcv,
        .needed_headroom        = OCELOT_TOTAL_TAG_LEN,
        .promisc_on_conduit     = true,
};

DSA_TAG_DRIVER(seville_netdev_ops);
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SEVILLE, SEVILLE_NAME);

static struct dsa_tag_driver *ocelot_tag_driver_array[] = {
        &DSA_TAG_DRIVER_NAME(ocelot_netdev_ops),
        &DSA_TAG_DRIVER_NAME(seville_netdev_ops),
};

module_dsa_tag_drivers(ocelot_tag_driver_array);

MODULE_DESCRIPTION("DSA tag driver for Ocelot family of switches, using NPI port");
MODULE_LICENSE("GPL v2");