sfc: commonise ARFS handling

EF100 will use the same approach to ARFS as EF10.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 234 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c
index e10c23833515..9927e9ecbbb4 100644
--- a/drivers/net/ethernet/sfc/rx_common.c
+++ b/drivers/net/ethernet/sfc/rx_common.c
@@ -849,3 +849,237 @@ void efx_remove_filters(struct efx_nic *efx)
 	efx->type->filter_table_remove(efx);
 	up_write(&efx->filter_sem);
 }
+
+#ifdef CONFIG_RFS_ACCEL
+
+static void efx_filter_rfs_work(struct work_struct *data)
+{
+	struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
+							      work);
+	struct efx_nic *efx = netdev_priv(req->net_dev);
+	struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
+	int slot_idx = req - efx->rps_slot;
+	struct efx_arfs_rule *rule;
+	u16 arfs_id = 0;
+	int rc;
+
+	rc = efx->type->filter_insert(efx, &req->spec, true);
+	if (rc >= 0)
+		/* Discard 'priority' part of EF10+ filter ID (mcdi_filters) */
+		rc %= efx->type->max_rx_ip_filters;
+	if (efx->rps_hash_table) {
+		spin_lock_bh(&efx->rps_hash_lock);
+		rule = efx_rps_hash_find(efx, &req->spec);
+		/* The rule might have already gone, if someone else's request
+		 * for the same spec was already worked and then expired before
+		 * we got around to our work.  In that case we have nothing
+		 * tying us to an arfs_id, meaning that as soon as the filter
+		 * is considered for expiry it will be removed.
+		 */
+		if (rule) {
+			if (rc < 0)
+				rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
+			else
+				rule->filter_id = rc;
+			arfs_id = rule->arfs_id;
+		}
+		spin_unlock_bh(&efx->rps_hash_lock);
+	}
+	if (rc >= 0) {
+		/* Remember this so we can check whether to expire the filter
+		 * later.
+		 */
+		mutex_lock(&efx->rps_mutex);
+		if (channel->rps_flow_id[rc] == RPS_FLOW_ID_INVALID)
+			channel->rfs_filter_count++;
+		channel->rps_flow_id[rc] = req->flow_id;
+		mutex_unlock(&efx->rps_mutex);
+
+		if (req->spec.ether_type == htons(ETH_P_IP))
+			netif_info(efx, rx_status, efx->net_dev,
+				   "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
+				   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
+				   req->spec.rem_host, ntohs(req->spec.rem_port),
+				   req->spec.loc_host, ntohs(req->spec.loc_port),
+				   req->rxq_index, req->flow_id, rc, arfs_id);
+		else
+			netif_info(efx, rx_status, efx->net_dev,
+				   "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
+				   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
+				   req->spec.rem_host, ntohs(req->spec.rem_port),
+				   req->spec.loc_host, ntohs(req->spec.loc_port),
+				   req->rxq_index, req->flow_id, rc, arfs_id);
+		channel->n_rfs_succeeded++;
+	} else {
+		if (req->spec.ether_type == htons(ETH_P_IP))
+			netif_dbg(efx, rx_status, efx->net_dev,
+				  "failed to steer %s %pI4:%u:%pI4:%u to queue %u [flow %u rc %d id %u]\n",
+				  (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
+				  req->spec.rem_host, ntohs(req->spec.rem_port),
+				  req->spec.loc_host, ntohs(req->spec.loc_port),
+				  req->rxq_index, req->flow_id, rc, arfs_id);
+		else
+			netif_dbg(efx, rx_status, efx->net_dev,
+				  "failed to steer %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u rc %d id %u]\n",
+				  (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
+				  req->spec.rem_host, ntohs(req->spec.rem_port),
+				  req->spec.loc_host, ntohs(req->spec.loc_port),
+				  req->rxq_index, req->flow_id, rc, arfs_id);
+		channel->n_rfs_failed++;
+		/* We're overloading the NIC's filter tables, so let's do a
+		 * chunk of extra expiry work.
+		 */
+		__efx_filter_rfs_expire(channel, min(channel->rfs_filter_count,
+						     100u));
+	}
+
+	/* Release references */
+	clear_bit(slot_idx, &efx->rps_slot_map);
+	dev_put(req->net_dev);
+}
+
+int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
+		   u16 rxq_index, u32 flow_id)
+{
+	struct efx_nic *efx = netdev_priv(net_dev);
+	struct efx_async_filter_insertion *req;
+	struct efx_arfs_rule *rule;
+	struct flow_keys fk;
+	int slot_idx;
+	bool new;
+	int rc;
+
+	/* find a free slot */
+	for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
+		if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
+			break;
+	if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
+		return -EBUSY;
+
+	if (flow_id == RPS_FLOW_ID_INVALID) {
+		rc = -EINVAL;
+		goto out_clear;
+	}
+
+	if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
+		rc = -EPROTONOSUPPORT;
+		goto out_clear;
+	}
+
+	if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
+		rc = -EPROTONOSUPPORT;
+		goto out_clear;
+	}
+	if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
+		rc = -EPROTONOSUPPORT;
+		goto out_clear;
+	}
+
+	req = efx->rps_slot + slot_idx;
+	efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
+			   efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
+			   rxq_index);
+	req->spec.match_flags =
+		EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
+		EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
+		EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
+	req->spec.ether_type = fk.basic.n_proto;
+	req->spec.ip_proto = fk.basic.ip_proto;
+
+	if (fk.basic.n_proto == htons(ETH_P_IP)) {
+		req->spec.rem_host[0] = fk.addrs.v4addrs.src;
+		req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
+	} else {
+		memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
+		       sizeof(struct in6_addr));
+		memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
+		       sizeof(struct in6_addr));
+	}
+
+	req->spec.rem_port = fk.ports.src;
+	req->spec.loc_port = fk.ports.dst;
+
+	if (efx->rps_hash_table) {
+		/* Add it to ARFS hash table */
+		spin_lock(&efx->rps_hash_lock);
+		rule = efx_rps_hash_add(efx, &req->spec, &new);
+		if (!rule) {
+			rc = -ENOMEM;
+			goto out_unlock;
+		}
+		if (new)
+			rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
+		rc = rule->arfs_id;
+		/* Skip if existing or pending filter already does the right thing */
+		if (!new && rule->rxq_index == rxq_index &&
+		    rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
+			goto out_unlock;
+		rule->rxq_index = rxq_index;
+		rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
+		spin_unlock(&efx->rps_hash_lock);
+	} else {
+		/* Without an ARFS hash table, we just use arfs_id 0 for all
+		 * filters.  This means if multiple flows hash to the same
+		 * flow_id, all but the most recently touched will be eligible
+		 * for expiry.
+		 */
+		rc = 0;
+	}
+
+	/* Queue the request */
+	dev_hold(req->net_dev = net_dev);
+	INIT_WORK(&req->work, efx_filter_rfs_work);
+	req->rxq_index = rxq_index;
+	req->flow_id = flow_id;
+	schedule_work(&req->work);
+	return rc;
+out_unlock:
+	spin_unlock(&efx->rps_hash_lock);
+out_clear:
+	clear_bit(slot_idx, &efx->rps_slot_map);
+	return rc;
+}
+
+bool __efx_filter_rfs_expire(struct efx_channel *channel, unsigned int quota)
+{
+	bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
+	struct efx_nic *efx = channel->efx;
+	unsigned int index, size, start;
+	u32 flow_id;
+
+	if (!mutex_trylock(&efx->rps_mutex))
+		return false;
+	expire_one = efx->type->filter_rfs_expire_one;
+	index = channel->rfs_expire_index;
+	start = index;
+	size = efx->type->max_rx_ip_filters;
+	while (quota) {
+		flow_id = channel->rps_flow_id[index];
+
+		if (flow_id != RPS_FLOW_ID_INVALID) {
+			quota--;
+			if (expire_one(efx, flow_id, index)) {
+				netif_info(efx, rx_status, efx->net_dev,
+					   "expired filter %d [channel %u flow %u]\n",
+					   index, channel->channel, flow_id);
+				channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
+				channel->rfs_filter_count--;
+			}
+		}
+		if (++index == size)
+			index = 0;
+		/* If we were called with a quota that exceeds the total number
+		 * of filters in the table (which shouldn't happen, but could
+		 * if two callers race), ensure that we don't loop forever -
+		 * stop when we've examined every row of the table.
+		 */
+		if (index == start)
+			break;
+	}
+
+	channel->rfs_expire_index = index;
+	mutex_unlock(&efx->rps_mutex);
+	return true;
+}
+
+#endif /* CONFIG_RFS_ACCEL */