drivers/net/ethernet/amazon/ena/ena_eth_com.h

/*
 * Copyright 2015 Amazon.com, Inc. or its affiliates.
 *
 * 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
 * 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.
 */

#ifndef ENA_ETH_COM_H_
#define ENA_ETH_COM_H_

#include "ena_com.h"

/* head update threshold in units of (queue size / ENA_COMP_HEAD_THRESH) */
#define ENA_COMP_HEAD_THRESH 4

struct ena_com_tx_ctx {
	struct ena_com_tx_meta ena_meta;
	struct ena_com_buf *ena_bufs;
	/* For LLQ, header buffer - pushed to the device mem space */
	void *push_header;

	enum ena_eth_io_l3_proto_index l3_proto;
	enum ena_eth_io_l4_proto_index l4_proto;
	u16 num_bufs;
	u16 req_id;
	/* For regular queue, indicate the size of the header
	 * For LLQ, indicate the size of the pushed buffer
	 */
	u16 header_len;

	u8 meta_valid;
	u8 tso_enable;
	u8 l3_csum_enable;
	u8 l4_csum_enable;
	u8 l4_csum_partial;
	u8 df; /* Don't fragment */
};

struct ena_com_rx_ctx {
	struct ena_com_rx_buf_info *ena_bufs;
	enum ena_eth_io_l3_proto_index l3_proto;
	enum ena_eth_io_l4_proto_index l4_proto;
	bool l3_csum_err;
	bool l4_csum_err;
	/* fragmented packet */
	bool frag;
	u32 hash;
	u16 descs;
	int max_bufs;
};

int ena_com_prepare_tx(struct ena_com_io_sq *io_sq,
		       struct ena_com_tx_ctx *ena_tx_ctx,
		       int *nb_hw_desc);

int ena_com_rx_pkt(struct ena_com_io_cq *io_cq,
		   struct ena_com_io_sq *io_sq,
		   struct ena_com_rx_ctx *ena_rx_ctx);

int ena_com_add_single_rx_desc(struct ena_com_io_sq *io_sq,
			       struct ena_com_buf *ena_buf,
			       u16 req_id);

int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq, u16 *req_id);

static inline void ena_com_unmask_intr(struct ena_com_io_cq *io_cq,
				       struct ena_eth_io_intr_reg *intr_reg)
{
	writel(intr_reg->intr_control, io_cq->unmask_reg);
}

static inline int ena_com_sq_empty_space(struct ena_com_io_sq *io_sq)
{
	u16 tail, next_to_comp, cnt;

	next_to_comp = io_sq->next_to_comp;
	tail = io_sq->tail;
	cnt = tail - next_to_comp;

	return io_sq->q_depth - 1 - cnt;
}

static inline int ena_com_write_sq_doorbell(struct ena_com_io_sq *io_sq)
{
	u16 tail;

	tail = io_sq->tail;

	pr_debug("write submission queue doorbell for queue: %d tail: %d\n",
		 io_sq->qid, tail);

	writel(tail, io_sq->db_addr);

	return 0;
}

static inline int ena_com_update_dev_comp_head(struct ena_com_io_cq *io_cq)
{
	u16 unreported_comp, head;
	bool need_update;

	head = io_cq->head;
	unreported_comp = head - io_cq->last_head_update;
	need_update = unreported_comp > (io_cq->q_depth / ENA_COMP_HEAD_THRESH);

	if (io_cq->cq_head_db_reg && need_update) {
		pr_debug("Write completion queue doorbell for queue %d: head: %d\n",
			 io_cq->qid, head);
		writel(head, io_cq->cq_head_db_reg);
		io_cq->last_head_update = head;
	}

	return 0;
}

static inline void ena_com_update_numa_node(struct ena_com_io_cq *io_cq,
					    u8 numa_node)
{
	struct ena_eth_io_numa_node_cfg_reg numa_cfg;

	if (!io_cq->numa_node_cfg_reg)
		return;

	numa_cfg.numa_cfg = (numa_node & ENA_ETH_IO_NUMA_NODE_CFG_REG_NUMA_MASK)
		| ENA_ETH_IO_NUMA_NODE_CFG_REG_ENABLED_MASK;

	writel(numa_cfg.numa_cfg, io_cq->numa_node_cfg_reg);
}

static inline void ena_com_comp_ack(struct ena_com_io_sq *io_sq, u16 elem)
{
	io_sq->next_to_comp += elem;
}

#endif /* ENA_ETH_COM_H_ */