Yikes, ran git format-patch one patch too soon. There's also a hidden,
bonus patch "12/11" below. Doesn't affect first 11 patches in any way,
though. Here it is.
>From f7f10232622309d66a7a1ae1932d0c081936d546 Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Date: Tue, 25 Oct 2022 02:32:24 +0300
Subject: [RFC PATCH net-next 12/12] net: enetc: add support for XDP_TX
with zero-copy XDP sockets
Add support for the case when the BPF program attached to a ring with an
XSK pool returns the XDP_TX verdict. The frame needs to go back on the
interface it came from.
No dma_map or dma_sync_for_device is necessary, just a small impedance
matching logic with the XDP_TX procedure we have in place for non-XSK,
since the data structures are different (xdp_buff vs xdp_frame; cannot
have multi-buffer with XSK).
In the TX confirmation routine, just release the RX buffer (as opposed
to non-XSK XDP_TX). Recycling might be possible, but I haven't
experimented with it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
drivers/net/ethernet/freescale/enetc/enetc.c | 35 ++++++++++++++++++--
drivers/net/ethernet/freescale/enetc/enetc.h | 1 +
2 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index bc0db788afc7..06aaf0334dc3 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -855,7 +855,9 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget,
tx_win_drop++;
}
- if (tx_swbd->is_xsk)
+ if (tx_swbd->is_xsk && tx_swbd->is_xdp_tx)
+ xsk_buff_free(tx_swbd->xsk_buff);
+ else if (tx_swbd->is_xsk)
(*xsk_confirmed)++;
else if (tx_swbd->is_xdp_tx)
enetc_recycle_xdp_tx_buff(tx_ring, tx_swbd);
@@ -1661,6 +1663,21 @@ static int enetc_rx_swbd_to_xdp_tx_swbd(struct enetc_tx_swbd *xdp_tx_arr,
return n;
}
+static bool enetc_xsk_xdp_tx(struct enetc_bdr *tx_ring,
+ struct xdp_buff *xsk_buff)
+{
+ struct enetc_tx_swbd tx_swbd = {
+ .dma = xsk_buff_xdp_get_dma(xsk_buff),
+ .len = xdp_get_buff_len(xsk_buff),
+ .is_xdp_tx = true,
+ .is_xsk = true,
+ .is_eof = true,
+ .xsk_buff = xsk_buff,
+ };
+
+ return enetc_xdp_tx(tx_ring, &tx_swbd, 1);
+}
+
static void enetc_xdp_drop(struct enetc_bdr *rx_ring, int rx_ring_first,
int rx_ring_last)
{
@@ -1839,10 +1856,12 @@ static int enetc_clean_rx_ring_xsk(struct enetc_bdr *rx_ring,
struct bpf_prog *prog,
struct xsk_buff_pool *pool)
{
+ struct enetc_ndev_priv *priv = netdev_priv(rx_ring->ndev);
+ struct enetc_bdr *tx_ring = priv->xdp_tx_ring[rx_ring->index];
+ int xdp_redirect_frm_cnt = 0, xdp_tx_frm_cnt = 0;
struct net_device *ndev = rx_ring->ndev;
union enetc_rx_bd *rxbd, *orig_rxbd;
int rx_frm_cnt = 0, rx_byte_cnt = 0;
- int xdp_redirect_frm_cnt = 0;
struct xdp_buff *xsk_buff;
int buffs_missing, err, i;
bool wakeup_xsk = false;
@@ -1895,6 +1914,15 @@ static int enetc_clean_rx_ring_xsk(struct enetc_bdr *rx_ring,
enetc_xsk_buff_to_skb(xsk_buff, rx_ring, orig_rxbd,
napi);
break;
+ case XDP_TX:
+ if (enetc_xsk_xdp_tx(tx_ring, xsk_buff)) {
+ xdp_tx_frm_cnt++;
+ tx_ring->stats.xdp_tx++;
+ } else {
+ xsk_buff_free(xsk_buff);
+ tx_ring->stats.xdp_tx_drops++;
+ }
+ break;
case XDP_REDIRECT:
err = xdp_do_redirect(ndev, xsk_buff, prog);
if (unlikely(err)) {
@@ -1919,6 +1947,9 @@ static int enetc_clean_rx_ring_xsk(struct enetc_bdr *rx_ring,
if (xdp_redirect_frm_cnt)
xdp_do_flush_map();
+ if (xdp_tx_frm_cnt)
+ enetc_update_tx_ring_tail(tx_ring);
+
if (xsk_uses_need_wakeup(pool)) {
if (wakeup_xsk)
xsk_set_rx_need_wakeup(pool);
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 403f40473b52..58df6c32cfb3 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -24,6 +24,7 @@ struct enetc_tx_swbd {
union {
struct sk_buff *skb;
struct xdp_frame *xdp_frame;
+ struct xdp_buff *xsk_buff;
};
dma_addr_t dma;
struct page *page; /* valid only if is_xdp_tx */
--
2.34.1
