net: enetc: add a dedicated is_eof bit in the TX software BD

In the transmit path, if we have a scatter/gather frame, it is put into
multiple software buffer descriptors, the last of which has the skb
pointer populated (which is necessary for rearming the TX MSI vector and
for collecting the two-step TX timestamp from the TX confirmation path).

At the moment, this is sufficient, but with XDP_TX, we'll need to
service TX software buffer descriptors that don't have an skb pointer,
however they might be final nonetheless. So add a dedicated bit for
final software BDs that we populate and check explicitly. Also, we keep
looking just for an skb when doing TX timestamping, because we don't
want/need that for XDP.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index b2071b8dc3168e0f3da8fef6159586a22b79e46c..37d2d142a744961f108e65900abe84d809763e4e 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -157,6 +157,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb,
        temp_bd.flags = flags;
        *txbd = temp_bd;
 
+       tx_ring->tx_swbd[i].is_eof = true;
        tx_ring->tx_swbd[i].skb = skb;
 
        enetc_bdr_idx_inc(tx_ring, &i);
@@ -316,8 +317,6 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
        do_tstamp = false;
 
        while (bds_to_clean && tx_frm_cnt < ENETC_DEFAULT_TX_WORK) {
-               bool is_eof = !!tx_swbd->skb;
-
                if (unlikely(tx_swbd->check_wb)) {
                        struct enetc_ndev_priv *priv = netdev_priv(ndev);
                        union enetc_tx_bd *txbd;
@@ -335,7 +334,7 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
                if (likely(tx_swbd->dma))
                        enetc_unmap_tx_buff(tx_ring, tx_swbd);
 
-               if (is_eof) {
+               if (tx_swbd->skb) {
                        if (unlikely(do_tstamp)) {
                                enetc_tstamp_tx(tx_swbd->skb, tstamp);
                                do_tstamp = false;
@@ -355,7 +354,7 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
                }
 
                /* BD iteration loop end */
-               if (is_eof) {
+               if (tx_swbd->is_eof) {
                        tx_frm_cnt++;
                        /* re-arm interrupt source */
                        enetc_wr_reg_hot(tx_ring->idr, BIT(tx_ring->index) |

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 773e412b9f4ea637a62d709e1049841d0134e487..d9e75644b89c2f2044e4adbff87ab3b9a26abe86 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -25,6 +25,7 @@ struct enetc_tx_swbd {
        u8 is_dma_page:1;
        u8 check_wb:1;
        u8 do_tstamp:1;
+       u8 is_eof:1;
 };
 
 #define ENETC_RX_MAXFRM_SIZE   ENETC_MAC_MAXFRM_SIZE