[PATCH 6.0 122/157] net: microchip: sparx5: correctly free skb in xmit

Greg Kroah-Hartman
2022-12-12T13:46:17Z

From: Casper Andersson <casper.casan@gmail.com>

[ Upstream commit 121c6672b0191ffcebff4b88ec022c39e0a95789 ]

consume_skb on transmitted, kfree_skb on dropped, do not free on
TX_BUSY.

Previously the xmit function could return -EBUSY without freeing, which
supposedly is interpreted as a drop. And was using kfree on successfully
transmitted packets.

sparx5_fdma_xmit and sparx5_inject returns error code, where -EBUSY
indicates TX_BUSY and any other error code indicates dropped.

Fixes: f3cad2611a77 ("net: sparx5: add hostmode with phylink support")
Signed-off-by: Casper Andersson <casper.casan@gmail.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../ethernet/microchip/sparx5/sparx5_fdma.c | 2 +-
.../ethernet/microchip/sparx5/sparx5_packet.c | 41 +++++++++++--------
2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c b/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c
index 66360c8c5a38..141897dfe388 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c
@@ -317,7 +317,7 @@ int sparx5_fdma_xmit(struct sparx5 *sparx5, u32 *ifh, struct sk_buff *skb)
next_dcb_hw = sparx5_fdma_next_dcb(tx, tx->curr_entry);
db_hw = &next_dcb_hw->db[0];
if (!(db_hw->status & FDMA_DCB_STATUS_DONE))
- tx->dropped++;
+ return -EINVAL;
db = list_first_entry(&tx->db_list, struct sparx5_db, list);
list_move_tail(&db->list, &tx->db_list);
next_dcb_hw->nextptr = FDMA_DCB_INVALID_DATA;
diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
index 21844beba72d..0ce0fc985222 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
@@ -234,9 +234,8 @@ int sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev)
sparx5_set_port_ifh(ifh, port->portno);

if (sparx5->ptp && skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
- ret = sparx5_ptp_txtstamp_request(port, skb);
- if (ret)
- return ret;
+ if (sparx5_ptp_txtstamp_request(port, skb) < 0)
+ return NETDEV_TX_BUSY;

sparx5_set_port_ifh_rew_op(ifh, SPARX5_SKB_CB(skb)->rew_op);
sparx5_set_port_ifh_pdu_type(ifh, SPARX5_SKB_CB(skb)->pdu_type);
@@ -250,23 +249,31 @@ int sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev)
else
ret = sparx5_inject(sparx5, ifh, skb, dev);

- if (ret == NETDEV_TX_OK) {
- stats->tx_bytes += skb->len;
- stats->tx_packets++;
+ if (ret == -EBUSY)
+ goto busy;
+ if (ret < 0)
+ goto drop;

- if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
- SPARX5_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
- return ret;
+ stats->tx_bytes += skb->len;
+ stats->tx_packets++;
+ sparx5->tx.packets++;

- dev_kfree_skb_any(skb);
- } else {
- stats->tx_dropped++;
+ if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
+ SPARX5_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
+ return NETDEV_TX_OK;

- if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
- SPARX5_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
- sparx5_ptp_txtstamp_release(port, skb);
- }
- return ret;
+ dev_consume_skb_any(skb);
+ return NETDEV_TX_OK;
+drop:
+ stats->tx_dropped++;
+ sparx5->tx.dropped++;
+ dev_kfree_skb_any(skb);
+ return NETDEV_TX_OK;
+busy:
+ if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
+ SPARX5_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
+ sparx5_ptp_txtstamp_release(port, skb);
+ return NETDEV_TX_BUSY;
}

static enum hrtimer_restart sparx5_injection_timeout(struct hrtimer *tmr)
--
2.35.1