drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c

/*
 * Copyright (c) 2015, Mellanox Technologies. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "en.h"

struct mlx5_cqe64 *mlx5e_get_cqe(struct mlx5e_cq *cq)
{
	struct mlx5_cqwq *wq = &cq->wq;
	u32 ci = mlx5_cqwq_get_ci(wq);
	struct mlx5_cqe64 *cqe = mlx5_cqwq_get_wqe(wq, ci);
	int cqe_ownership_bit = cqe->op_own & MLX5_CQE_OWNER_MASK;
	int sw_ownership_val = mlx5_cqwq_get_wrap_cnt(wq) & 1;

	if (cqe_ownership_bit != sw_ownership_val)
		return NULL;

	/* ensure cqe content is read after cqe ownership bit */
	rmb();

	return cqe;
}

int mlx5e_napi_poll(struct napi_struct *napi, int budget)
{
	struct mlx5e_channel *c = container_of(napi, struct mlx5e_channel,
					       napi);
	bool busy = false;
	int work_done;
	int i;

	clear_bit(MLX5E_CHANNEL_NAPI_SCHED, &c->flags);

	for (i = 0; i < c->num_tc; i++)
		busy |= mlx5e_poll_tx_cq(&c->sq[i].cq, budget);

	work_done = mlx5e_poll_rx_cq(&c->rq.cq, budget);
	busy |= work_done == budget;
	busy |= mlx5e_post_rx_wqes(&c->rq);

	if (busy)
		return budget;

	napi_complete_done(napi, work_done);

	/* avoid losing completion event during/after polling cqs */
	if (test_bit(MLX5E_CHANNEL_NAPI_SCHED, &c->flags)) {
		napi_schedule(napi);
		return work_done;
	}

	for (i = 0; i < c->num_tc; i++)
		mlx5e_cq_arm(&c->sq[i].cq);
	mlx5e_cq_arm(&c->rq.cq);

	return work_done;
}

void mlx5e_completion_event(struct mlx5_core_cq *mcq)
{
	struct mlx5e_cq *cq = container_of(mcq, struct mlx5e_cq, mcq);

	set_bit(MLX5E_CHANNEL_NAPI_SCHED, &cq->channel->flags);
	barrier();
	napi_schedule(cq->napi);
}

void mlx5e_cq_error_event(struct mlx5_core_cq *mcq, enum mlx5_event event)
{
	struct mlx5e_cq *cq = container_of(mcq, struct mlx5e_cq, mcq);
	struct mlx5e_channel *c = cq->channel;
	struct mlx5e_priv *priv = c->priv;
	struct net_device *netdev = priv->netdev;

	netdev_err(netdev, "%s: cqn=0x%.6x event=0x%.2x\n",
		   __func__, mcq->cqn, event);
}