// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
// Copyright (c) 2019 Mellanox Technologies.

#include "en_accel/tls.h"
#include "en_accel/ktls_txrx.h"
#include "en_accel/ktls_utils.h"

struct mlx5e_dump_wqe {
        struct mlx5_wqe_ctrl_seg ctrl;
        struct mlx5_wqe_data_seg data;
};

#define MLX5E_KTLS_DUMP_WQEBBS \
        (DIV_ROUND_UP(sizeof(struct mlx5e_dump_wqe), MLX5_SEND_WQE_BB))

static u8
mlx5e_ktls_dumps_num_wqes(struct mlx5e_params *params, unsigned int nfrags,
                          unsigned int sync_len)
{
        /* Given the MTU and sync_len, calculates an upper bound for the
         * number of DUMP WQEs needed for the TX resync of a record.
         */
        return nfrags + DIV_ROUND_UP(sync_len, MLX5E_SW2HW_MTU(params, params->sw_mtu));
}

u16 mlx5e_ktls_get_stop_room(struct mlx5_core_dev *mdev, struct mlx5e_params *params)
{
        u16 num_dumps, stop_room = 0;

        if (!mlx5e_accel_is_ktls_tx(mdev))
                return 0;

        num_dumps = mlx5e_ktls_dumps_num_wqes(params, MAX_SKB_FRAGS, TLS_MAX_PAYLOAD_SIZE);

        stop_room += mlx5e_stop_room_for_wqe(MLX5E_TLS_SET_STATIC_PARAMS_WQEBBS);
        stop_room += mlx5e_stop_room_for_wqe(MLX5E_TLS_SET_PROGRESS_PARAMS_WQEBBS);
        stop_room += num_dumps * mlx5e_stop_room_for_wqe(MLX5E_KTLS_DUMP_WQEBBS);

        return stop_room;
}

static int mlx5e_ktls_create_tis(struct mlx5_core_dev *mdev, u32 *tisn)
{
        u32 in[MLX5_ST_SZ_DW(create_tis_in)] = {};
        void *tisc;

        tisc = MLX5_ADDR_OF(create_tis_in, in, ctx);

        MLX5_SET(tisc, tisc, tls_en, 1);

        return mlx5e_create_tis(mdev, in, tisn);
}

struct mlx5e_ktls_offload_context_tx {
        struct tls_offload_context_tx *tx_ctx;
        struct tls12_crypto_info_aes_gcm_128 crypto_info;
        struct mlx5e_tls_sw_stats *sw_stats;
        u32 expected_seq;
        u32 tisn;
        u32 key_id;
        bool ctx_post_pending;
};

static void
mlx5e_set_ktls_tx_priv_ctx(struct tls_context *tls_ctx,
                           struct mlx5e_ktls_offload_context_tx *priv_tx)
{
        struct mlx5e_ktls_offload_context_tx **ctx =
                __tls_driver_ctx(tls_ctx, TLS_OFFLOAD_CTX_DIR_TX);

        BUILD_BUG_ON(sizeof(struct mlx5e_ktls_offload_context_tx *) >
                     TLS_OFFLOAD_CONTEXT_SIZE_TX);

        *ctx = priv_tx;
}

static struct mlx5e_ktls_offload_context_tx *
mlx5e_get_ktls_tx_priv_ctx(struct tls_context *tls_ctx)
{
        struct mlx5e_ktls_offload_context_tx **ctx =
                __tls_driver_ctx(tls_ctx, TLS_OFFLOAD_CTX_DIR_TX);

        return *ctx;
}

int mlx5e_ktls_add_tx(struct net_device *netdev, struct sock *sk,
                      struct tls_crypto_info *crypto_info, u32 start_offload_tcp_sn)
{
        struct mlx5e_ktls_offload_context_tx *priv_tx;
        struct tls_context *tls_ctx;
        struct mlx5_core_dev *mdev;
        struct mlx5e_priv *priv;
        int err;

        tls_ctx = tls_get_ctx(sk);
        priv = netdev_priv(netdev);
        mdev = priv->mdev;

        priv_tx = kzalloc(sizeof(*priv_tx), GFP_KERNEL);
        if (!priv_tx)
                return -ENOMEM;

        err = mlx5_ktls_create_key(mdev, crypto_info, &priv_tx->key_id);
        if (err)
                goto err_create_key;

        priv_tx->sw_stats = &priv->tls->sw_stats;
        priv_tx->expected_seq = start_offload_tcp_sn;
        priv_tx->crypto_info  =
                *(struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
        priv_tx->tx_ctx = tls_offload_ctx_tx(tls_ctx);

        mlx5e_set_ktls_tx_priv_ctx(tls_ctx, priv_tx);

        err = mlx5e_ktls_create_tis(mdev, &priv_tx->tisn);
        if (err)
                goto err_create_tis;

        priv_tx->ctx_post_pending = true;
        atomic64_inc(&priv_tx->sw_stats->tx_tls_ctx);

        return 0;

err_create_tis:
        mlx5_ktls_destroy_key(mdev, priv_tx->key_id);
err_create_key:
        kfree(priv_tx);
        return err;
}

void mlx5e_ktls_del_tx(struct net_device *netdev, struct tls_context *tls_ctx)
{
        struct mlx5e_ktls_offload_context_tx *priv_tx;
        struct mlx5_core_dev *mdev;
        struct mlx5e_priv *priv;

        priv_tx = mlx5e_get_ktls_tx_priv_ctx(tls_ctx);
        priv = netdev_priv(netdev);
        mdev = priv->mdev;

        atomic64_inc(&priv_tx->sw_stats->tx_tls_del);
        mlx5e_destroy_tis(mdev, priv_tx->tisn);
        mlx5_ktls_destroy_key(mdev, priv_tx->key_id);
        kfree(priv_tx);
}

static void tx_fill_wi(struct mlx5e_txqsq *sq,
                       u16 pi, u8 num_wqebbs, u32 num_bytes,
                       struct page *page)
{
        struct mlx5e_tx_wqe_info *wi = &sq->db.wqe_info[pi];

        *wi = (struct mlx5e_tx_wqe_info) {
                .num_wqebbs = num_wqebbs,
                .num_bytes  = num_bytes,
                .resync_dump_frag_page = page,
        };
}

static bool
mlx5e_ktls_tx_offload_test_and_clear_pending(struct mlx5e_ktls_offload_context_tx *priv_tx)
{
        bool ret = priv_tx->ctx_post_pending;

        priv_tx->ctx_post_pending = false;

        return ret;
}

static void
post_static_params(struct mlx5e_txqsq *sq,
                   struct mlx5e_ktls_offload_context_tx *priv_tx,
                   bool fence)
{
        struct mlx5e_set_tls_static_params_wqe *wqe;
        u16 pi, num_wqebbs;

        num_wqebbs = MLX5E_TLS_SET_STATIC_PARAMS_WQEBBS;
        pi = mlx5e_txqsq_get_next_pi(sq, num_wqebbs);
        wqe = MLX5E_TLS_FETCH_SET_STATIC_PARAMS_WQE(sq, pi);
        mlx5e_ktls_build_static_params(wqe, sq->pc, sq->sqn, &priv_tx->crypto_info,
                                       priv_tx->tisn, priv_tx->key_id, 0, fence,
                                       TLS_OFFLOAD_CTX_DIR_TX);
        tx_fill_wi(sq, pi, num_wqebbs, 0, NULL);
        sq->pc += num_wqebbs;
}

static void
post_progress_params(struct mlx5e_txqsq *sq,
                     struct mlx5e_ktls_offload_context_tx *priv_tx,
                     bool fence)
{
        struct mlx5e_set_tls_progress_params_wqe *wqe;
        u16 pi, num_wqebbs;

        num_wqebbs = MLX5E_TLS_SET_PROGRESS_PARAMS_WQEBBS;
        pi = mlx5e_txqsq_get_next_pi(sq, num_wqebbs);
        wqe = MLX5E_TLS_FETCH_SET_PROGRESS_PARAMS_WQE(sq, pi);
        mlx5e_ktls_build_progress_params(wqe, sq->pc, sq->sqn, priv_tx->tisn, fence, 0,
                                         TLS_OFFLOAD_CTX_DIR_TX);
        tx_fill_wi(sq, pi, num_wqebbs, 0, NULL);
        sq->pc += num_wqebbs;
}

static void
mlx5e_ktls_tx_post_param_wqes(struct mlx5e_txqsq *sq,
                              struct mlx5e_ktls_offload_context_tx *priv_tx,
                              bool skip_static_post, bool fence_first_post)
{
        bool progress_fence = skip_static_post || !fence_first_post;

        if (!skip_static_post)
                post_static_params(sq, priv_tx, fence_first_post);

        post_progress_params(sq, priv_tx, progress_fence);
}

struct tx_sync_info {
        u64 rcd_sn;
        u32 sync_len;
        int nr_frags;
        skb_frag_t frags[MAX_SKB_FRAGS];
};

enum mlx5e_ktls_sync_retval {
        MLX5E_KTLS_SYNC_DONE,
        MLX5E_KTLS_SYNC_FAIL,
        MLX5E_KTLS_SYNC_SKIP_NO_DATA,
};

static enum mlx5e_ktls_sync_retval
tx_sync_info_get(struct mlx5e_ktls_offload_context_tx *priv_tx,
                 u32 tcp_seq, int datalen, struct tx_sync_info *info)
{
        struct tls_offload_context_tx *tx_ctx = priv_tx->tx_ctx;
        enum mlx5e_ktls_sync_retval ret = MLX5E_KTLS_SYNC_DONE;
        struct tls_record_info *record;
        int remaining, i = 0;
        unsigned long flags;
        bool ends_before;

        spin_lock_irqsave(&tx_ctx->lock, flags);
        record = tls_get_record(tx_ctx, tcp_seq, &info->rcd_sn);

        if (unlikely(!record)) {
                ret = MLX5E_KTLS_SYNC_FAIL;
                goto out;
        }

        /* There are the following cases:
         * 1. packet ends before start marker: bypass offload.
         * 2. packet starts before start marker and ends after it: drop,
         *    not supported, breaks contract with kernel.
         * 3. packet ends before tls record info starts: drop,
         *    this packet was already acknowledged and its record info
         *    was released.
         */
        ends_before = before(tcp_seq + datalen - 1, tls_record_start_seq(record));

        if (unlikely(tls_record_is_start_marker(record))) {
                ret = ends_before ? MLX5E_KTLS_SYNC_SKIP_NO_DATA : MLX5E_KTLS_SYNC_FAIL;
                goto out;
        } else if (ends_before) {
                ret = MLX5E_KTLS_SYNC_FAIL;
                goto out;
        }

        info->sync_len = tcp_seq - tls_record_start_seq(record);
        remaining = info->sync_len;
        while (remaining > 0) {
                skb_frag_t *frag = &record->frags[i];

                get_page(skb_frag_page(frag));
                remaining -= skb_frag_size(frag);
                info->frags[i++] = *frag;
        }
        /* reduce the part which will be sent with the original SKB */
        if (remaining < 0)
                skb_frag_size_add(&info->frags[i - 1], remaining);
        info->nr_frags = i;
out:
        spin_unlock_irqrestore(&tx_ctx->lock, flags);
        return ret;
}

static void
tx_post_resync_params(struct mlx5e_txqsq *sq,
                      struct mlx5e_ktls_offload_context_tx *priv_tx,
                      u64 rcd_sn)
{
        struct tls12_crypto_info_aes_gcm_128 *info = &priv_tx->crypto_info;
        __be64 rn_be = cpu_to_be64(rcd_sn);
        bool skip_static_post;
        u16 rec_seq_sz;
        char *rec_seq;

        rec_seq = info->rec_seq;
        rec_seq_sz = sizeof(info->rec_seq);

        skip_static_post = !memcmp(rec_seq, &rn_be, rec_seq_sz);
        if (!skip_static_post)
                memcpy(rec_seq, &rn_be, rec_seq_sz);

        mlx5e_ktls_tx_post_param_wqes(sq, priv_tx, skip_static_post, true);
}

static int
tx_post_resync_dump(struct mlx5e_txqsq *sq, skb_frag_t *frag, u32 tisn, bool first)
{
        struct mlx5_wqe_ctrl_seg *cseg;
        struct mlx5_wqe_data_seg *dseg;
        struct mlx5e_dump_wqe *wqe;
        dma_addr_t dma_addr = 0;
        u16 ds_cnt;
        int fsz;
        u16 pi;

        BUILD_BUG_ON(MLX5E_KTLS_DUMP_WQEBBS != 1);
        pi = mlx5_wq_cyc_ctr2ix(&sq->wq, sq->pc);
        wqe = MLX5E_TLS_FETCH_DUMP_WQE(sq, pi);

        ds_cnt = sizeof(*wqe) / MLX5_SEND_WQE_DS;

        cseg = &wqe->ctrl;
        dseg = &wqe->data;

        cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8)  | MLX5_OPCODE_DUMP);
        cseg->qpn_ds           = cpu_to_be32((sq->sqn << 8) | ds_cnt);
        cseg->tis_tir_num      = cpu_to_be32(tisn << 8);
        cseg->fm_ce_se         = first ? MLX5_FENCE_MODE_INITIATOR_SMALL : 0;

        fsz = skb_frag_size(frag);
        dma_addr = skb_frag_dma_map(sq->pdev, frag, 0, fsz,
                                    DMA_TO_DEVICE);
        if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
                return -ENOMEM;

        dseg->addr       = cpu_to_be64(dma_addr);
        dseg->lkey       = sq->mkey_be;
        dseg->byte_count = cpu_to_be32(fsz);
        mlx5e_dma_push(sq, dma_addr, fsz, MLX5E_DMA_MAP_PAGE);

        tx_fill_wi(sq, pi, MLX5E_KTLS_DUMP_WQEBBS, fsz, skb_frag_page(frag));
        sq->pc += MLX5E_KTLS_DUMP_WQEBBS;

        return 0;
}

void mlx5e_ktls_tx_handle_resync_dump_comp(struct mlx5e_txqsq *sq,
                                           struct mlx5e_tx_wqe_info *wi,
                                           u32 *dma_fifo_cc)
{
        struct mlx5e_sq_stats *stats;
        struct mlx5e_sq_dma *dma;

        dma = mlx5e_dma_get(sq, (*dma_fifo_cc)++);
        stats = sq->stats;

        mlx5e_tx_dma_unmap(sq->pdev, dma);
        put_page(wi->resync_dump_frag_page);
        stats->tls_dump_packets++;
        stats->tls_dump_bytes += wi->num_bytes;
}

static void tx_post_fence_nop(struct mlx5e_txqsq *sq)
{
        struct mlx5_wq_cyc *wq = &sq->wq;
        u16 pi = mlx5_wq_cyc_ctr2ix(wq, sq->pc);

        tx_fill_wi(sq, pi, 1, 0, NULL);

        mlx5e_post_nop_fence(wq, sq->sqn, &sq->pc);
}

static enum mlx5e_ktls_sync_retval
mlx5e_ktls_tx_handle_ooo(struct mlx5e_ktls_offload_context_tx *priv_tx,
                         struct mlx5e_txqsq *sq,
                         int datalen,
                         u32 seq)
{
        struct mlx5e_sq_stats *stats = sq->stats;
        enum mlx5e_ktls_sync_retval ret;
        struct tx_sync_info info = {};
        int i = 0;

        ret = tx_sync_info_get(priv_tx, seq, datalen, &info);
        if (unlikely(ret != MLX5E_KTLS_SYNC_DONE)) {
                if (ret == MLX5E_KTLS_SYNC_SKIP_NO_DATA) {
                        stats->tls_skip_no_sync_data++;
                        return MLX5E_KTLS_SYNC_SKIP_NO_DATA;
                }
                /* We might get here if a retransmission reaches the driver
                 * after the relevant record is acked.
                 * It should be safe to drop the packet in this case
                 */
                stats->tls_drop_no_sync_data++;
                goto err_out;
        }

        stats->tls_ooo++;

        tx_post_resync_params(sq, priv_tx, info.rcd_sn);

        /* If no dump WQE was sent, we need to have a fence NOP WQE before the
         * actual data xmit.
         */
        if (!info.nr_frags) {
                tx_post_fence_nop(sq);
                return MLX5E_KTLS_SYNC_DONE;
        }

        for (; i < info.nr_frags; i++) {
                unsigned int orig_fsz, frag_offset = 0, n = 0;
                skb_frag_t *f = &info.frags[i];

                orig_fsz = skb_frag_size(f);

                do {
                        bool fence = !(i || frag_offset);
                        unsigned int fsz;

                        n++;
                        fsz = min_t(unsigned int, sq->hw_mtu, orig_fsz - frag_offset);
                        skb_frag_size_set(f, fsz);
                        if (tx_post_resync_dump(sq, f, priv_tx->tisn, fence)) {
                                page_ref_add(skb_frag_page(f), n - 1);
                                goto err_out;
                        }

                        skb_frag_off_add(f, fsz);
                        frag_offset += fsz;
                } while (frag_offset < orig_fsz);

                page_ref_add(skb_frag_page(f), n - 1);
        }

        return MLX5E_KTLS_SYNC_DONE;

err_out:
        for (; i < info.nr_frags; i++)
                /* The put_page() here undoes the page ref obtained in tx_sync_info_get().
                 * Page refs obtained for the DUMP WQEs above (by page_ref_add) will be
                 * released only upon their completions (or in mlx5e_free_txqsq_descs,
                 * if channel closes).
                 */
                put_page(skb_frag_page(&info.frags[i]));

        return MLX5E_KTLS_SYNC_FAIL;
}

bool mlx5e_ktls_handle_tx_skb(struct tls_context *tls_ctx, struct mlx5e_txqsq *sq,
                              struct sk_buff *skb, int datalen,
                              struct mlx5e_accel_tx_tls_state *state)
{
        struct mlx5e_ktls_offload_context_tx *priv_tx;
        struct mlx5e_sq_stats *stats = sq->stats;
        u32 seq;

        priv_tx = mlx5e_get_ktls_tx_priv_ctx(tls_ctx);

        if (unlikely(mlx5e_ktls_tx_offload_test_and_clear_pending(priv_tx))) {
                mlx5e_ktls_tx_post_param_wqes(sq, priv_tx, false, false);
        }

        seq = ntohl(tcp_hdr(skb)->seq);
        if (unlikely(priv_tx->expected_seq != seq)) {
                enum mlx5e_ktls_sync_retval ret =
                        mlx5e_ktls_tx_handle_ooo(priv_tx, sq, datalen, seq);

                switch (ret) {
                case MLX5E_KTLS_SYNC_DONE:
                        break;
                case MLX5E_KTLS_SYNC_SKIP_NO_DATA:
                        if (likely(!skb->decrypted))
                                goto out;
                        WARN_ON_ONCE(1);
                        fallthrough;
                case MLX5E_KTLS_SYNC_FAIL:
                        goto err_out;
                }
        }

        priv_tx->expected_seq = seq + datalen;

        state->tls_tisn = priv_tx->tisn;

        stats->tls_encrypted_packets += skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1;
        stats->tls_encrypted_bytes   += datalen;

out:
        return true;

err_out:
        dev_kfree_skb_any(skb);
        return false;
}