/*-
 *   BSD LICENSE
 * 
 *   Copyright(c) 2010-2013 Intel Corporation. All rights reserved.
 *   All rights reserved.
 * 
 *   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.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 * 
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "rte_eth_ring.h"
#include <rte_mbuf.h>
#include <rte_ethdev.h>
#include <rte_malloc.h>
#include <rte_memcpy.h>
#include <rte_string_fns.h>

struct ring_queue {
	struct rte_ring *rng;
	volatile unsigned long rx_pkts;
	volatile unsigned long tx_pkts;
	volatile unsigned long err_pkts;
};

struct pmd_internals {
	unsigned nb_rx_queues;
	unsigned nb_tx_queues;

	struct ring_queue rx_ring_queues[RTE_PMD_RING_MAX_RX_RINGS];
	struct ring_queue tx_ring_queues[RTE_PMD_RING_MAX_TX_RINGS];
};


static struct ether_addr eth_addr = { .addr_bytes = {0} };
static const char *drivername = "Rings PMD";
static struct rte_eth_link pmd_link = {
		.link_speed = 10000,
		.link_duplex = ETH_LINK_FULL_DUPLEX,
		.link_status = 0
};

static uint16_t
eth_ring_rx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
{
	void **ptrs = (void *)&bufs[0];
	struct ring_queue *r = q;
	const uint16_t nb_rx = (uint16_t)rte_ring_dequeue_burst(r->rng, 
			ptrs, nb_bufs);
	if (r->rng->flags & RING_F_SC_DEQ)
		r->rx_pkts += nb_rx;
	else
		__sync_fetch_and_add(&r->rx_pkts, nb_rx);
	return nb_rx;
}

static uint16_t
eth_ring_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
{
	void **ptrs = (void *)&bufs[0];
	struct ring_queue *r = q;
	const uint16_t nb_tx = (uint16_t)rte_ring_enqueue_burst(r->rng, 
			ptrs, nb_bufs);
	if (r->rng->flags & RING_F_SP_ENQ) {
		r->tx_pkts += nb_tx;
		r->err_pkts += nb_bufs - nb_tx;
	} else {
		__sync_fetch_and_add(&r->tx_pkts, nb_tx);
		__sync_fetch_and_add(&r->err_pkts, nb_bufs - nb_tx);
	}
	return nb_tx;
}

static int
eth_dev_configure(struct rte_eth_dev *dev __rte_unused) { return 0; }

static int
eth_dev_start(struct rte_eth_dev *dev)
{
	dev->data->dev_link.link_status = 1;
	return 0;
}

static void
eth_dev_stop(struct rte_eth_dev *dev)
{
	dev->data->dev_link.link_status = 0;
}

static int
eth_rx_queue_setup(struct rte_eth_dev *dev,uint16_t rx_queue_id,
				    uint16_t nb_rx_desc __rte_unused,
				    unsigned int socket_id __rte_unused,
				    const struct rte_eth_rxconf *rx_conf __rte_unused,
				    struct rte_mempool *mb_pool __rte_unused)
{
	struct pmd_internals *internals = dev->data->dev_private;
	dev->data->rx_queues[rx_queue_id] = &internals->rx_ring_queues[rx_queue_id];
	return 0;
}

static int
eth_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
				    uint16_t nb_tx_desc __rte_unused,
				    unsigned int socket_id __rte_unused,
				    const struct rte_eth_txconf *tx_conf __rte_unused)
{
	struct pmd_internals *internals = dev->data->dev_private;
	dev->data->tx_queues[tx_queue_id] = &internals->tx_ring_queues[tx_queue_id];
	return 0;
}


static void
eth_dev_info(struct rte_eth_dev *dev,
		struct rte_eth_dev_info *dev_info)
{
	struct pmd_internals *internals = dev->data->dev_private;
	dev_info->driver_name = drivername;
	dev_info->max_mac_addrs = 1;
	dev_info->max_rx_pktlen = (uint32_t)-1;
	dev_info->max_rx_queues = (uint16_t)internals->nb_rx_queues;
	dev_info->max_tx_queues = (uint16_t)internals->nb_tx_queues;
	dev_info->min_rx_bufsize = 0;
	dev_info->pci_dev = NULL;
}

static void
eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *igb_stats)
{
	unsigned i;
	unsigned long rx_total = 0, tx_total = 0, tx_err_total = 0;
	const struct pmd_internals *internal = dev->data->dev_private;

	memset(igb_stats, 0, sizeof(*igb_stats));
	for (i = 0; i < RTE_ETHDEV_QUEUE_STAT_CNTRS &&
			i < internal->nb_rx_queues; i++) {
		igb_stats->q_ipackets[i] = internal->rx_ring_queues[i].rx_pkts;
		rx_total += igb_stats->q_ipackets[i];
	}

	for (i = 0; i < RTE_ETHDEV_QUEUE_STAT_CNTRS &&
			i < internal->nb_tx_queues; i++) {
		igb_stats->q_opackets[i] = internal->tx_ring_queues[i].tx_pkts;
		igb_stats->q_errors[i] = internal->tx_ring_queues[i].err_pkts;
		tx_total += igb_stats->q_opackets[i];
		tx_err_total += igb_stats->q_errors[i];
	}

	igb_stats->ipackets = rx_total;
	igb_stats->opackets = tx_total;
	igb_stats->oerrors = tx_err_total;
}

static void
eth_stats_reset(struct rte_eth_dev *dev)
{
	unsigned i;
	struct pmd_internals *internal = dev->data->dev_private;
	for (i = 0; i < internal->nb_rx_queues; i++)
		internal->rx_ring_queues[i].rx_pkts = 0;
	for (i = 0; i < internal->nb_tx_queues; i++) {
		internal->tx_ring_queues[i].tx_pkts = 0;
		internal->tx_ring_queues[i].err_pkts = 0;
	}
}

static void
eth_queue_release(void *q __rte_unused) { ; }
static int
eth_link_update(struct rte_eth_dev *dev __rte_unused,
		int wait_to_complete __rte_unused) { return 0; }

static struct eth_dev_ops ops = {
		.dev_start = eth_dev_start,
		.dev_stop = eth_dev_stop,
		.dev_configure = eth_dev_configure,
		.dev_infos_get = eth_dev_info,
		.rx_queue_setup = eth_rx_queue_setup,
		.tx_queue_setup = eth_tx_queue_setup,
		.rx_queue_release = eth_queue_release,
		.tx_queue_release = eth_queue_release,
		.link_update = eth_link_update,
		.stats_get = eth_stats_get,
		.stats_reset = eth_stats_reset,
};

int
rte_eth_from_rings(struct rte_ring *const rx_queues[],
		const unsigned nb_rx_queues,
		struct rte_ring *const tx_queues[],
		const unsigned nb_tx_queues,
		const unsigned numa_node)
{
	struct rte_eth_dev_data *data = NULL;
	struct rte_pci_device *pci_dev = NULL;
	struct pmd_internals *internals = NULL;
	struct rte_eth_dev *eth_dev = NULL;
	unsigned i;

	RTE_LOG(INFO, PMD, "Creating rings-backed ethdev on numa socket %u\n",
			numa_node);

	/* do some paramter checking */
	if (rx_queues == NULL && nb_rx_queues > 0)
		goto error;
	if (tx_queues == NULL && nb_tx_queues > 0)
		goto error;

	/* now do all data allocation - for eth_dev structure, dummy pci driver
	 * and internal (private) data
	 */
	data = rte_zmalloc_socket(NULL, sizeof(*data), 0, numa_node);
	if (data == NULL)
		goto error;

	pci_dev = rte_zmalloc_socket(NULL, sizeof(*pci_dev), 0, numa_node);
	if (pci_dev == NULL)
		goto error;

	internals = rte_zmalloc_socket(NULL, sizeof(*internals), 0, numa_node);
	if (internals == NULL)
		goto error;

	/* reserve an ethdev entry */
	eth_dev = rte_eth_dev_allocate();
	if (eth_dev == NULL)
		goto error;

	/* now put it all together
	 * - store queue data in internals,
	 * - store numa_node info in pci_driver
	 * - point eth_dev_data to internals and pci_driver
	 * - and point eth_dev structure to new eth_dev_data structure
	 */
	/* NOTE: we'll replace the data element, of originally allocated eth_dev
	 * so the rings are local per-process */

	internals->nb_rx_queues = nb_rx_queues;
	internals->nb_tx_queues = nb_tx_queues;
	for (i = 0; i < nb_rx_queues; i++) {
		internals->rx_ring_queues[i].rng = rx_queues[i];
	}
	for (i = 0; i < nb_tx_queues; i++) {
		internals->tx_ring_queues[i].rng = tx_queues[i];
	}

	pci_dev->numa_node = numa_node;

	data->dev_private = internals;
	data->port_id = eth_dev->data->port_id;
	data->nb_rx_queues = (uint16_t)nb_rx_queues;
	data->nb_tx_queues = (uint16_t)nb_tx_queues;
	data->dev_link = pmd_link;
	data->mac_addrs = &eth_addr;

	eth_dev ->data = data;
	eth_dev ->dev_ops = &ops;
	eth_dev ->pci_dev = pci_dev;

	/* finally assign rx and tx ops */
	eth_dev->rx_pkt_burst = eth_ring_rx;
	eth_dev->tx_pkt_burst = eth_ring_tx;

	return 0;

error:
	if (data)
		rte_free(data);
	if (pci_dev)
		rte_free(pci_dev);
	if (internals)
		rte_free(internals);
	return -1;
}

enum dev_action{
	DEV_CREATE,
	DEV_ATTACH
};

static int
eth_dev_ring_create(const char *name, const unsigned numa_node,
		enum dev_action action)
{
	/* rx and tx are so-called from point of view of first port.
	 * They are inverted from the point of view of second port
	 */
	struct rte_ring *rxtx[RTE_PMD_RING_MAX_RX_RINGS];
	unsigned i;
	char rng_name[RTE_RING_NAMESIZE];
	unsigned num_rings = RTE_MIN(RTE_PMD_RING_MAX_RX_RINGS,
			RTE_PMD_RING_MAX_TX_RINGS);

	for (i = 0; i < num_rings; i++) {
		rte_snprintf(rng_name, sizeof(rng_name), "ETH_RXTX%u_%s", i, name);
		rxtx[i] = (action == DEV_CREATE) ?
				rte_ring_create(rng_name, 1024, numa_node,
						RING_F_SP_ENQ|RING_F_SC_DEQ) :
				rte_ring_lookup(rng_name);
		if (rxtx[i] == NULL)
			return -1;
	}

	if (rte_eth_from_rings(rxtx, num_rings, rxtx, num_rings, numa_node))
		return -1;

	return 0;
}


static int
eth_dev_ring_pair_create(const char *name, const unsigned numa_node,
		enum dev_action action)
{
	/* rx and tx are so-called from point of view of first port.
	 * They are inverted from the point of view of second port
	 */
	struct rte_ring *rx[RTE_PMD_RING_MAX_RX_RINGS];
	struct rte_ring *tx[RTE_PMD_RING_MAX_TX_RINGS];
	unsigned i;
	char rng_name[RTE_RING_NAMESIZE];
	unsigned num_rings = RTE_MIN(RTE_PMD_RING_MAX_RX_RINGS,
			RTE_PMD_RING_MAX_TX_RINGS);

	for (i = 0; i < num_rings; i++) {
		rte_snprintf(rng_name, sizeof(rng_name), "ETH_RX%u_%s", i, name);
		rx[i] = (action == DEV_CREATE) ?
				rte_ring_create(rng_name, 1024, numa_node,
						RING_F_SP_ENQ|RING_F_SC_DEQ) :
				rte_ring_lookup(rng_name);
		if (rx[i] == NULL)
			return -1;
		rte_snprintf(rng_name, sizeof(rng_name), "ETH_TX%u_%s", i, name);
		tx[i] = (action == DEV_CREATE) ?
				rte_ring_create(rng_name, 1024, numa_node,
						RING_F_SP_ENQ|RING_F_SC_DEQ):
				rte_ring_lookup(rng_name);
		if (tx[i] == NULL)
			return -1;
	}

	if (rte_eth_from_rings(rx, num_rings, tx, num_rings, numa_node) ||
			rte_eth_from_rings(tx, num_rings, rx, num_rings, numa_node) )
		return -1;

	return 0;
}

int
rte_eth_ring_pair_create(const char *name, const unsigned numa_node)
{
	return eth_dev_ring_pair_create(name, numa_node, DEV_CREATE);
}

int
rte_eth_ring_pair_attach(const char *name, const unsigned numa_node)
{
	return eth_dev_ring_pair_create(name, numa_node, DEV_ATTACH);
}

int
rte_pmd_ring_init(const char *name, const char *params)
{
	if (params == NULL)
		eth_dev_ring_create(name, rte_socket_id(), DEV_CREATE);
	else {
		RTE_LOG(INFO, PMD, "Ignoring unsupported parameters when creating"
				" rings-backed ethernet device\n");
		eth_dev_ring_create(name, rte_socket_id(), DEV_CREATE);
	}
	return 0;
}