From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 1d587faa5be7e9785b682cc5f58ba8f4100c13ea ]
This small snippet of code ensures that we do something with the array of RX software buffer descriptor elements after passing the skb to the stack. In this case, we see if the other half of the page is reusable, and if so, we "turn around" the buffers, making them directly usable by enetc_refill_rx_ring() without going to enetc_new_page().
We will need to perform this kind of buffer flipping from a new code path, i.e. from XDP_PASS. Currently, enetc_build_skb() does it there buffer by buffer, but in a subsequent change we will stop using enetc_build_skb() for XDP_PASS.
Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Wei Fang wei.fang@nxp.com Link: https://patch.msgid.link/20250417120005.3288549-3-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/freescale/enetc/enetc.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 2106861463e40..15f510d0913d3 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -1850,6 +1850,16 @@ static void enetc_xdp_drop(struct enetc_bdr *rx_ring, int rx_ring_first, } }
+static void enetc_bulk_flip_buff(struct enetc_bdr *rx_ring, int rx_ring_first, + int rx_ring_last) +{ + while (rx_ring_first != rx_ring_last) { + enetc_flip_rx_buff(rx_ring, + &rx_ring->rx_swbd[rx_ring_first]); + enetc_bdr_idx_inc(rx_ring, &rx_ring_first); + } +} + static int enetc_clean_rx_ring_xdp(struct enetc_bdr *rx_ring, struct napi_struct *napi, int work_limit, struct bpf_prog *prog) @@ -1965,11 +1975,7 @@ static int enetc_clean_rx_ring_xdp(struct enetc_bdr *rx_ring, enetc_xdp_drop(rx_ring, orig_i, i); rx_ring->stats.xdp_redirect_failures++; } else { - while (orig_i != i) { - enetc_flip_rx_buff(rx_ring, - &rx_ring->rx_swbd[orig_i]); - enetc_bdr_idx_inc(rx_ring, &orig_i); - } + enetc_bulk_flip_buff(rx_ring, orig_i, i); xdp_redirect_frm_cnt++; rx_ring->stats.xdp_redirect++; }