// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/* Copyright (c) 2019-2020, Mellanox Technologies inc. All rights reserved. */

#include <net/xdp_sock_drv.h>
#include "pool.h"
#include "setup.h"
#include "en/params.h"

static int mlx5e_xsk_map_pool(struct mlx5e_priv *priv,
                              struct xsk_buff_pool *pool)
{
        struct device *dev = mlx5_core_dma_dev(priv->mdev);

        return xsk_pool_dma_map(pool, dev, 0);
}

static void mlx5e_xsk_unmap_pool(struct mlx5e_priv *priv,
                                 struct xsk_buff_pool *pool)
{
        return xsk_pool_dma_unmap(pool, 0);
}

static int mlx5e_xsk_get_pools(struct mlx5e_xsk *xsk)
{
        if (!xsk->pools) {
                xsk->pools = kcalloc(MLX5E_MAX_NUM_CHANNELS,
                                     sizeof(*xsk->pools), GFP_KERNEL);
                if (unlikely(!xsk->pools))
                        return -ENOMEM;
        }

        xsk->refcnt++;
        xsk->ever_used = true;

        return 0;
}

static void mlx5e_xsk_put_pools(struct mlx5e_xsk *xsk)
{
        if (!--xsk->refcnt) {
                kfree(xsk->pools);
                xsk->pools = NULL;
        }
}

static int mlx5e_xsk_add_pool(struct mlx5e_xsk *xsk, struct xsk_buff_pool *pool, u16 ix)
{
        int err;

        err = mlx5e_xsk_get_pools(xsk);
        if (unlikely(err))
                return err;

        xsk->pools[ix] = pool;
        return 0;
}

static void mlx5e_xsk_remove_pool(struct mlx5e_xsk *xsk, u16 ix)
{
        xsk->pools[ix] = NULL;

        mlx5e_xsk_put_pools(xsk);
}

static bool mlx5e_xsk_is_pool_sane(struct xsk_buff_pool *pool)
{
        return xsk_pool_get_headroom(pool) <= 0xffff &&
                xsk_pool_get_chunk_size(pool) <= 0xffff;
}

void mlx5e_build_xsk_param(struct xsk_buff_pool *pool, struct mlx5e_xsk_param *xsk)
{
        xsk->headroom = xsk_pool_get_headroom(pool);
        xsk->chunk_size = xsk_pool_get_chunk_size(pool);
}

static int mlx5e_xsk_enable_locked(struct mlx5e_priv *priv,
                                   struct xsk_buff_pool *pool, u16 ix)
{
        struct mlx5e_params *params = &priv->channels.params;
        struct mlx5e_xsk_param xsk;
        struct mlx5e_channel *c;
        int err;

        if (unlikely(mlx5e_xsk_get_pool(&priv->channels.params, &priv->xsk, ix)))
                return -EBUSY;

        if (unlikely(!mlx5e_xsk_is_pool_sane(pool)))
                return -EINVAL;

        err = mlx5e_xsk_map_pool(priv, pool);
        if (unlikely(err))
                return err;

        err = mlx5e_xsk_add_pool(&priv->xsk, pool, ix);
        if (unlikely(err))
                goto err_unmap_pool;

        mlx5e_build_xsk_param(pool, &xsk);

        if (!test_bit(MLX5E_STATE_OPENED, &priv->state)) {
                /* XSK objects will be created on open. */
                goto validate_closed;
        }

        if (!params->xdp_prog) {
                /* XSK objects will be created when an XDP program is set,
                 * and the channels are reopened.
                 */
                goto validate_closed;
        }

        c = priv->channels.c[ix];

        err = mlx5e_open_xsk(priv, params, &xsk, pool, c);
        if (unlikely(err))
                goto err_remove_pool;

        mlx5e_activate_xsk(c);

        /* Don't wait for WQEs, because the newer xdpsock sample doesn't provide
         * any Fill Ring entries at the setup stage.
         */

        err = mlx5e_xsk_redirect_rqt_to_channel(priv, priv->channels.c[ix]);
        if (unlikely(err))
                goto err_deactivate;

        return 0;

err_deactivate:
        mlx5e_deactivate_xsk(c);
        mlx5e_close_xsk(c);

err_remove_pool:
        mlx5e_xsk_remove_pool(&priv->xsk, ix);

err_unmap_pool:
        mlx5e_xsk_unmap_pool(priv, pool);

        return err;

validate_closed:
        /* Check the configuration in advance, rather than fail at a later stage
         * (in mlx5e_xdp_set or on open) and end up with no channels.
         */
        if (!mlx5e_validate_xsk_param(params, &xsk, priv->mdev)) {
                err = -EINVAL;
                goto err_remove_pool;
        }

        return 0;
}

static int mlx5e_xsk_disable_locked(struct mlx5e_priv *priv, u16 ix)
{
        struct xsk_buff_pool *pool = mlx5e_xsk_get_pool(&priv->channels.params,
                                                   &priv->xsk, ix);
        struct mlx5e_channel *c;

        if (unlikely(!pool))
                return -EINVAL;

        if (!test_bit(MLX5E_STATE_OPENED, &priv->state))
                goto remove_pool;

        /* XSK RQ and SQ are only created if XDP program is set. */
        if (!priv->channels.params.xdp_prog)
                goto remove_pool;

        c = priv->channels.c[ix];
        mlx5e_xsk_redirect_rqt_to_drop(priv, ix);
        mlx5e_deactivate_xsk(c);
        mlx5e_close_xsk(c);

remove_pool:
        mlx5e_xsk_remove_pool(&priv->xsk, ix);
        mlx5e_xsk_unmap_pool(priv, pool);

        return 0;
}

static int mlx5e_xsk_enable_pool(struct mlx5e_priv *priv, struct xsk_buff_pool *pool,
                                 u16 ix)
{
        int err;

        mutex_lock(&priv->state_lock);
        err = mlx5e_xsk_enable_locked(priv, pool, ix);
        mutex_unlock(&priv->state_lock);

        return err;
}

static int mlx5e_xsk_disable_pool(struct mlx5e_priv *priv, u16 ix)
{
        int err;

        mutex_lock(&priv->state_lock);
        err = mlx5e_xsk_disable_locked(priv, ix);
        mutex_unlock(&priv->state_lock);

        return err;
}

int mlx5e_xsk_setup_pool(struct net_device *dev, struct xsk_buff_pool *pool, u16 qid)
{
        struct mlx5e_priv *priv = netdev_priv(dev);
        struct mlx5e_params *params = &priv->channels.params;
        u16 ix;

        if (unlikely(!mlx5e_qid_get_ch_if_in_group(params, qid, MLX5E_RQ_GROUP_XSK, &ix)))
                return -EINVAL;

        return pool ? mlx5e_xsk_enable_pool(priv, pool, ix) :
                      mlx5e_xsk_disable_pool(priv, ix);
}