[PATCH net-next v4 2/3] net: stmmac: add Rx HWTS metadata to XDP receive pkt

From: Song Yoong Siang
Date: Wed Apr 12 2023 - 23:27:02 EST


Add receive hardware timestamp metadata support via kfunc to XDP receive
packets.

Suggested-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Signed-off-by: Song Yoong Siang <yoong.siang.song@xxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 3 ++
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 40 ++++++++++++++++++-
2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index ac8ccf851708..826ac0ec88c6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -94,6 +94,9 @@ struct stmmac_rx_buffer {

struct stmmac_xdp_buff {
struct xdp_buff xdp;
+ struct stmmac_priv *priv;
+ struct dma_desc *p;
+ struct dma_desc *np;
};

struct stmmac_rx_queue {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 6ffce52ca837..831a3e22e0d8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -5313,10 +5313,15 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)

xdp_init_buff(&ctx.xdp, buf_sz, &rx_q->xdp_rxq);
xdp_prepare_buff(&ctx.xdp, page_address(buf->page),
- buf->page_offset, buf1_len, false);
+ buf->page_offset, buf1_len, true);

pre_len = ctx.xdp.data_end - ctx.xdp.data_hard_start -
buf->page_offset;
+
+ ctx.priv = priv;
+ ctx.p = p;
+ ctx.np = np;
+
skb = stmmac_xdp_run_prog(priv, &ctx.xdp);
/* Due xdp_adjust_tail: DMA sync for_device
* cover max len CPU touch
@@ -7060,6 +7065,37 @@ void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable)
}
}

+static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64 *timestamp)
+{
+ const struct stmmac_xdp_buff *ctx = (void *)_ctx;
+ struct stmmac_priv *priv = ctx->priv;
+ struct dma_desc *desc = ctx->p;
+ struct dma_desc *np = ctx->np;
+ struct dma_desc *p = ctx->p;
+ u64 ns = 0;
+
+ if (!priv->hwts_rx_en)
+ return -ENODATA;
+
+ /* For GMAC4, the valid timestamp is from CTX next desc. */
+ if (priv->plat->has_gmac4 || priv->plat->has_xgmac)
+ desc = np;
+
+ /* Check if timestamp is available */
+ if (stmmac_get_rx_timestamp_status(priv, p, np, priv->adv_ts)) {
+ stmmac_get_timestamp(priv, desc, priv->adv_ts, &ns);
+ ns -= priv->plat->cdc_error_adj;
+ *timestamp = ns_to_ktime(ns);
+ return 0;
+ }
+
+ return -ENODATA;
+}
+
+static const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
+ .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
+};
+
/**
* stmmac_dvr_probe
* @device: device pointer
@@ -7167,6 +7203,8 @@ int stmmac_dvr_probe(struct device *device,

ndev->netdev_ops = &stmmac_netdev_ops;

+ ndev->xdp_metadata_ops = &stmmac_xdp_metadata_ops;
+
ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
NETIF_F_RXCSUM;
ndev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
--
2.34.1