eth: fbnic: support ring channel get and set while down

Trivial implementation of ethtool channel get and set. Set is only
supported when device is closed, next patch will add code for
live reconfig.

Asymmetric configurations are supported (combined + extra Tx or Rx),
so are configurations with independent IRQs for Rx and Tx.
Having all 3 NAPI types (combined, Tx, Rx) is not supported.

We used to only call fbnic_reset_indir_tbl() during init.
Now that we call it after device had been register must
be careful not to override user config.

Link: https://patch.msgid.link/20241220025241.1522781-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index d1be8fc304046500c8e47285951dc00cdd6aa618..d2fe97ae6a7161cd410065e9e9c08cd67aa34b62 100644 (file)
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -304,6 +304,68 @@ fbnic_set_rxfh(struct net_device *netdev, struct ethtool_rxfh_param *rxfh,
        return 0;
 }
 
+static void fbnic_get_channels(struct net_device *netdev,
+                              struct ethtool_channels *ch)
+{
+       struct fbnic_net *fbn = netdev_priv(netdev);
+       struct fbnic_dev *fbd = fbn->fbd;
+
+       ch->max_rx = fbd->max_num_queues;
+       ch->max_tx = fbd->max_num_queues;
+       ch->max_combined = min(ch->max_rx, ch->max_tx);
+       ch->max_other = FBNIC_NON_NAPI_VECTORS;
+
+       if (fbn->num_rx_queues > fbn->num_napi ||
+           fbn->num_tx_queues > fbn->num_napi)
+               ch->combined_count = min(fbn->num_rx_queues,
+                                        fbn->num_tx_queues);
+       else
+               ch->combined_count =
+                       fbn->num_rx_queues + fbn->num_tx_queues - fbn->num_napi;
+       ch->rx_count = fbn->num_rx_queues - ch->combined_count;
+       ch->tx_count = fbn->num_tx_queues - ch->combined_count;
+       ch->other_count = FBNIC_NON_NAPI_VECTORS;
+}
+
+static void fbnic_set_queues(struct fbnic_net *fbn, struct ethtool_channels *ch,
+                            unsigned int max_napis)
+{
+       fbn->num_rx_queues = ch->rx_count + ch->combined_count;
+       fbn->num_tx_queues = ch->tx_count + ch->combined_count;
+       fbn->num_napi = min(ch->rx_count + ch->tx_count + ch->combined_count,
+                           max_napis);
+}
+
+static int fbnic_set_channels(struct net_device *netdev,
+                             struct ethtool_channels *ch)
+{
+       struct fbnic_net *fbn = netdev_priv(netdev);
+       unsigned int max_napis, standalone;
+       struct fbnic_dev *fbd = fbn->fbd;
+
+       max_napis = fbd->num_irqs - FBNIC_NON_NAPI_VECTORS;
+       standalone = ch->rx_count + ch->tx_count;
+
+       /* Limits for standalone queues:
+        *  - each queue has it's own NAPI (num_napi >= rx + tx + combined)
+        *  - combining queues (combined not 0, rx or tx must be 0)
+        */
+       if ((ch->rx_count && ch->tx_count && ch->combined_count) ||
+           (standalone && standalone + ch->combined_count > max_napis) ||
+           ch->rx_count + ch->combined_count > fbd->max_num_queues ||
+           ch->tx_count + ch->combined_count > fbd->max_num_queues ||
+           ch->other_count != FBNIC_NON_NAPI_VECTORS)
+               return -EINVAL;
+
+       if (!netif_running(netdev)) {
+               fbnic_set_queues(fbn, ch, max_napis);
+               fbnic_reset_indir_tbl(fbn);
+               return 0;
+       }
+
+       return -EBUSY;
+}
+
 static int
 fbnic_get_ts_info(struct net_device *netdev,
                  struct kernel_ethtool_ts_info *tsinfo)
@@ -417,6 +479,8 @@ static const struct ethtool_ops fbnic_ethtool_ops = {
        .get_rxfh_indir_size    = fbnic_get_rxfh_indir_size,
        .get_rxfh               = fbnic_get_rxfh,
        .set_rxfh               = fbnic_set_rxfh,
+       .get_channels           = fbnic_get_channels,
+       .set_channels           = fbnic_set_channels,
        .get_ts_info            = fbnic_get_ts_info,
        .get_ts_stats           = fbnic_get_ts_stats,
        .get_eth_mac_stats      = fbnic_get_eth_mac_stats,

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c b/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c
index b99c890ac43f6ebc7b7b074a63f17d5a76379b8e..c25bd300b9024792132c466926d7677adb63561c 100644 (file)
--- a/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c
@@ -13,6 +13,9 @@ void fbnic_reset_indir_tbl(struct fbnic_net *fbn)
        unsigned int num_rx = fbn->num_rx_queues;
        unsigned int i;
 
+       if (netif_is_rxfh_configured(fbn->netdev))
+               return;
+
        for (i = 0; i < FBNIC_RPC_RSS_TBL_SIZE; i++)
                fbn->indir_tbl[0][i] = ethtool_rxfh_indir_default(i, num_rx);
 }