xref: /openbmc/linux/drivers/net/ethernet/sfc/ef100_rep.c (revision f50e8fcda6b8d39db9098f7e1146dc491696ab91)

// SPDX-License-Identifier: GPL-2.0-only
/****************************************************************************
 * Driver for Solarflare network controllers and boards
 * Copyright 2019 Solarflare Communications Inc.
 * Copyright 2020-2022 Xilinx Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation, incorporated herein by reference.
 */

#include "ef100_rep.h"
#include "ef100_netdev.h"
#include "ef100_nic.h"
#include "mae.h"
#include "rx_common.h"

#define EFX_EF100_REP_DRIVER	"efx_ef100_rep"

#define EFX_REP_DEFAULT_PSEUDO_RING_SIZE	64

static int efx_ef100_rep_poll(struct napi_struct *napi, int weight);

static int efx_ef100_rep_init_struct(struct efx_nic *efx, struct efx_rep *efv,
				     unsigned int i)
{
	efv->parent = efx;
	efv->idx = i;
	INIT_LIST_HEAD(&efv->list);
	INIT_LIST_HEAD(&efv->rx_list);
	spin_lock_init(&efv->rx_lock);
	efv->msg_enable = NETIF_MSG_DRV | NETIF_MSG_PROBE |
			  NETIF_MSG_LINK | NETIF_MSG_IFDOWN |
			  NETIF_MSG_IFUP | NETIF_MSG_RX_ERR |
			  NETIF_MSG_TX_ERR | NETIF_MSG_HW;
	return 0;
}

static int efx_ef100_rep_open(struct net_device *net_dev)
{
	struct efx_rep *efv = netdev_priv(net_dev);

	netif_napi_add(net_dev, &efv->napi, efx_ef100_rep_poll,
		       NAPI_POLL_WEIGHT);
	napi_enable(&efv->napi);
	return 0;
}

static int efx_ef100_rep_close(struct net_device *net_dev)
{
	struct efx_rep *efv = netdev_priv(net_dev);

	napi_disable(&efv->napi);
	netif_napi_del(&efv->napi);
	return 0;
}

static netdev_tx_t efx_ef100_rep_xmit(struct sk_buff *skb,
				      struct net_device *dev)
{
	struct efx_rep *efv = netdev_priv(dev);
	struct efx_nic *efx = efv->parent;
	netdev_tx_t rc;

	/* __ef100_hard_start_xmit() will always return success even in the
	 * case of TX drops, where it will increment efx's tx_dropped.  The
	 * efv stats really only count attempted TX, not success/failure.
	 */
	atomic64_inc(&efv->stats.tx_packets);
	atomic64_add(skb->len, &efv->stats.tx_bytes);
	netif_tx_lock(efx->net_dev);
	rc = __ef100_hard_start_xmit(skb, efx, dev, efv);
	netif_tx_unlock(efx->net_dev);
	return rc;
}

static int efx_ef100_rep_get_port_parent_id(struct net_device *dev,
					    struct netdev_phys_item_id *ppid)
{
	struct efx_rep *efv = netdev_priv(dev);
	struct efx_nic *efx = efv->parent;
	struct ef100_nic_data *nic_data;

	nic_data = efx->nic_data;
	/* nic_data->port_id is a u8[] */
	ppid->id_len = sizeof(nic_data->port_id);
	memcpy(ppid->id, nic_data->port_id, sizeof(nic_data->port_id));
	return 0;
}

static int efx_ef100_rep_get_phys_port_name(struct net_device *dev,
					    char *buf, size_t len)
{
	struct efx_rep *efv = netdev_priv(dev);
	struct efx_nic *efx = efv->parent;
	struct ef100_nic_data *nic_data;
	int ret;

	nic_data = efx->nic_data;
	ret = snprintf(buf, len, "p%upf%uvf%u", efx->port_num,
		       nic_data->pf_index, efv->idx);
	if (ret >= len)
		return -EOPNOTSUPP;

	return 0;
}

static void efx_ef100_rep_get_stats64(struct net_device *dev,
				      struct rtnl_link_stats64 *stats)
{
	struct efx_rep *efv = netdev_priv(dev);

	stats->rx_packets = atomic64_read(&efv->stats.rx_packets);
	stats->tx_packets = atomic64_read(&efv->stats.tx_packets);
	stats->rx_bytes = atomic64_read(&efv->stats.rx_bytes);
	stats->tx_bytes = atomic64_read(&efv->stats.tx_bytes);
	stats->rx_dropped = atomic64_read(&efv->stats.rx_dropped);
	stats->tx_errors = atomic64_read(&efv->stats.tx_errors);
}

static const struct net_device_ops efx_ef100_rep_netdev_ops = {
	.ndo_open		= efx_ef100_rep_open,
	.ndo_stop		= efx_ef100_rep_close,
	.ndo_start_xmit		= efx_ef100_rep_xmit,
	.ndo_get_port_parent_id	= efx_ef100_rep_get_port_parent_id,
	.ndo_get_phys_port_name	= efx_ef100_rep_get_phys_port_name,
	.ndo_get_stats64	= efx_ef100_rep_get_stats64,
};

static void efx_ef100_rep_get_drvinfo(struct net_device *dev,
				      struct ethtool_drvinfo *drvinfo)
{
	strscpy(drvinfo->driver, EFX_EF100_REP_DRIVER, sizeof(drvinfo->driver));
}

static u32 efx_ef100_rep_ethtool_get_msglevel(struct net_device *net_dev)
{
	struct efx_rep *efv = netdev_priv(net_dev);

	return efv->msg_enable;
}

static void efx_ef100_rep_ethtool_set_msglevel(struct net_device *net_dev,
					       u32 msg_enable)
{
	struct efx_rep *efv = netdev_priv(net_dev);

	efv->msg_enable = msg_enable;
}

static const struct ethtool_ops efx_ef100_rep_ethtool_ops = {
	.get_drvinfo		= efx_ef100_rep_get_drvinfo,
	.get_msglevel		= efx_ef100_rep_ethtool_get_msglevel,
	.set_msglevel		= efx_ef100_rep_ethtool_set_msglevel,
};

static struct efx_rep *efx_ef100_rep_create_netdev(struct efx_nic *efx,
						   unsigned int i)
{
	struct net_device *net_dev;
	struct efx_rep *efv;
	int rc;

	net_dev = alloc_etherdev_mq(sizeof(*efv), 1);
	if (!net_dev)
		return ERR_PTR(-ENOMEM);

	efv = netdev_priv(net_dev);
	rc = efx_ef100_rep_init_struct(efx, efv, i);
	if (rc)
		goto fail1;
	efv->net_dev = net_dev;
	rtnl_lock();
	spin_lock_bh(&efx->vf_reps_lock);
	list_add_tail(&efv->list, &efx->vf_reps);
	spin_unlock_bh(&efx->vf_reps_lock);
	if (netif_running(efx->net_dev) && efx->state == STATE_NET_UP) {
		netif_device_attach(net_dev);
		netif_carrier_on(net_dev);
	} else {
		netif_carrier_off(net_dev);
		netif_tx_stop_all_queues(net_dev);
	}
	rtnl_unlock();

	net_dev->netdev_ops = &efx_ef100_rep_netdev_ops;
	net_dev->ethtool_ops = &efx_ef100_rep_ethtool_ops;
	net_dev->min_mtu = EFX_MIN_MTU;
	net_dev->max_mtu = EFX_MAX_MTU;
	net_dev->features |= NETIF_F_LLTX;
	net_dev->hw_features |= NETIF_F_LLTX;
	return efv;
fail1:
	free_netdev(net_dev);
	return ERR_PTR(rc);
}

static int efx_ef100_configure_rep(struct efx_rep *efv)
{
	struct efx_nic *efx = efv->parent;
	u32 selector;
	int rc;

	efv->rx_pring_size = EFX_REP_DEFAULT_PSEUDO_RING_SIZE;
	/* Construct mport selector for corresponding VF */
	efx_mae_mport_vf(efx, efv->idx, &selector);
	/* Look up actual mport ID */
	rc = efx_mae_lookup_mport(efx, selector, &efv->mport);
	if (rc)
		return rc;
	pci_dbg(efx->pci_dev, "VF %u has mport ID %#x\n", efv->idx, efv->mport);
	/* mport label should fit in 16 bits */
	WARN_ON(efv->mport >> 16);

	return 0;
}

static void efx_ef100_rep_destroy_netdev(struct efx_rep *efv)
{
	struct efx_nic *efx = efv->parent;

	rtnl_lock();
	spin_lock_bh(&efx->vf_reps_lock);
	list_del(&efv->list);
	spin_unlock_bh(&efx->vf_reps_lock);
	rtnl_unlock();
	synchronize_rcu();
	free_netdev(efv->net_dev);
}

int efx_ef100_vfrep_create(struct efx_nic *efx, unsigned int i)
{
	struct efx_rep *efv;
	int rc;

	efv = efx_ef100_rep_create_netdev(efx, i);
	if (IS_ERR(efv)) {
		rc = PTR_ERR(efv);
		pci_err(efx->pci_dev,
			"Failed to create representor for VF %d, rc %d\n", i,
			rc);
		return rc;
	}
	rc = efx_ef100_configure_rep(efv);
	if (rc) {
		pci_err(efx->pci_dev,
			"Failed to configure representor for VF %d, rc %d\n",
			i, rc);
		goto fail;
	}
	rc = register_netdev(efv->net_dev);
	if (rc) {
		pci_err(efx->pci_dev,
			"Failed to register representor for VF %d, rc %d\n",
			i, rc);
		goto fail;
	}
	pci_dbg(efx->pci_dev, "Representor for VF %d is %s\n", i,
		efv->net_dev->name);
	return 0;
fail:
	efx_ef100_rep_destroy_netdev(efv);
	return rc;
}

void efx_ef100_vfrep_destroy(struct efx_nic *efx, struct efx_rep *efv)
{
	struct net_device *rep_dev;

	rep_dev = efv->net_dev;
	if (!rep_dev)
		return;
	netif_dbg(efx, drv, rep_dev, "Removing VF representor\n");
	unregister_netdev(rep_dev);
	efx_ef100_rep_destroy_netdev(efv);
}

void efx_ef100_fini_vfreps(struct efx_nic *efx)
{
	struct ef100_nic_data *nic_data = efx->nic_data;
	struct efx_rep *efv, *next;

	if (!nic_data->grp_mae)
		return;

	list_for_each_entry_safe(efv, next, &efx->vf_reps, list)
		efx_ef100_vfrep_destroy(efx, efv);
}

static int efx_ef100_rep_poll(struct napi_struct *napi, int weight)
{
	struct efx_rep *efv = container_of(napi, struct efx_rep, napi);
	unsigned int read_index;
	struct list_head head;
	struct sk_buff *skb;
	bool need_resched;
	int spent = 0;

	INIT_LIST_HEAD(&head);
	/* Grab up to 'weight' pending SKBs */
	spin_lock_bh(&efv->rx_lock);
	read_index = efv->write_index;
	while (spent < weight && !list_empty(&efv->rx_list)) {
		skb = list_first_entry(&efv->rx_list, struct sk_buff, list);
		list_del(&skb->list);
		list_add_tail(&skb->list, &head);
		spent++;
	}
	spin_unlock_bh(&efv->rx_lock);
	/* Receive them */
	netif_receive_skb_list(&head);
	if (spent < weight)
		if (napi_complete_done(napi, spent)) {
			spin_lock_bh(&efv->rx_lock);
			efv->read_index = read_index;
			/* If write_index advanced while we were doing the
			 * RX, then storing our read_index won't re-prime the
			 * fake-interrupt.  In that case, we need to schedule
			 * NAPI again to consume the additional packet(s).
			 */
			need_resched = efv->write_index != read_index;
			spin_unlock_bh(&efv->rx_lock);
			if (need_resched)
				napi_schedule(&efv->napi);
		}
	return spent;
}

void efx_ef100_rep_rx_packet(struct efx_rep *efv, struct efx_rx_buffer *rx_buf)
{
	u8 *eh = efx_rx_buf_va(rx_buf);
	struct sk_buff *skb;
	bool primed;

	/* Don't allow too many queued SKBs to build up, as they consume
	 * GFP_ATOMIC memory.  If we overrun, just start dropping.
	 */
	if (efv->write_index - READ_ONCE(efv->read_index) > efv->rx_pring_size) {
		atomic64_inc(&efv->stats.rx_dropped);
		if (net_ratelimit())
			netif_dbg(efv->parent, rx_err, efv->net_dev,
				  "nodesc-dropped packet of length %u\n",
				  rx_buf->len);
		return;
	}

	skb = netdev_alloc_skb(efv->net_dev, rx_buf->len);
	if (!skb) {
		atomic64_inc(&efv->stats.rx_dropped);
		if (net_ratelimit())
			netif_dbg(efv->parent, rx_err, efv->net_dev,
				  "noskb-dropped packet of length %u\n",
				  rx_buf->len);
		return;
	}
	memcpy(skb->data, eh, rx_buf->len);
	__skb_put(skb, rx_buf->len);

	skb_record_rx_queue(skb, 0); /* rep is single-queue */

	/* Move past the ethernet header */
	skb->protocol = eth_type_trans(skb, efv->net_dev);

	skb_checksum_none_assert(skb);

	atomic64_inc(&efv->stats.rx_packets);
	atomic64_add(rx_buf->len, &efv->stats.rx_bytes);

	/* Add it to the rx list */
	spin_lock_bh(&efv->rx_lock);
	primed = efv->read_index == efv->write_index;
	list_add_tail(&skb->list, &efv->rx_list);
	efv->write_index++;
	spin_unlock_bh(&efv->rx_lock);
	/* Trigger rx work */
	if (primed)
		napi_schedule(&efv->napi);
}

struct efx_rep *efx_ef100_find_rep_by_mport(struct efx_nic *efx, u16 mport)
{
	struct efx_rep *efv, *out = NULL;

	/* spinlock guards against list mutation while we're walking it;
	 * but caller must also hold rcu_read_lock() to ensure the netdev
	 * isn't freed after we drop the spinlock.
	 */
	spin_lock_bh(&efx->vf_reps_lock);
	list_for_each_entry(efv, &efx->vf_reps, list)
		if (efv->mport == mport) {
			out = efv;
			break;
		}
	spin_unlock_bh(&efx->vf_reps_lock);
	return out;
}