[Intel-wired-lan] [PATCH bpf-next v3 3/5] net: ice: Add xmo_rx_checksum callback

Lorenzo Bianconi
2026-02-17T08:34:47Z

Implement xmo_rx_checksum callback in ice driver to report RX checksum
result to the eBPF program bounded to the NIC.
Introduce ice_get_rx_csum utility routine in order to make the rx checksum
code reusable from ice_rx_csum()

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 118 +++++++++++++++++---------
1 file changed, 76 insertions(+), 42 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
index 956da38d63b0032db238325dcff818bbd99478e9..65b34b29f396560739fc58293496a5e9ddf09b53 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
@@ -81,69 +81,47 @@ ice_rx_hash_to_skb(const struct ice_rx_ring *rx_ring,
libeth_rx_pt_set_hash(skb, hash, decoded);
}

-/**
- * ice_rx_gcs - Set generic checksum in skb
- * @skb: skb currently being received and modified
- * @rx_desc: receive descriptor
- */
-static void ice_rx_gcs(struct sk_buff *skb,
- const union ice_32b_rx_flex_desc *rx_desc)
-{
- const struct ice_32b_rx_flex_desc_nic *desc;
- u16 csum;
-
- desc = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
- skb->ip_summed = CHECKSUM_COMPLETE;
- csum = (__force u16)desc->raw_csum;
- skb->csum = csum_unfold((__force __sum16)swab16(csum));
-}
-
-/**
- * ice_rx_csum - Indicate in skb if checksum is good
- * @ring: the ring we care about
- * @skb: skb currently being received and modified
- * @rx_desc: the receive descriptor
- * @ptype: the packet type decoded by hardware
- *
- * skb->protocol must be set before this function is called
- */
static void
-ice_rx_csum(struct ice_rx_ring *ring, struct sk_buff *skb,
- union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
+ice_get_rx_csum(const union ice_32b_rx_flex_desc *rx_desc, u16 ptype,
+ struct ice_rx_ring *ring, enum xdp_checksum *ip_summed,
+ u32 *cksum_meta)
{
- struct libeth_rx_pt decoded;
+ struct libeth_rx_pt decoded = libie_rx_pt_parse(ptype);
u16 rx_status0, rx_status1;
bool ipv4, ipv6;

- /* Start with CHECKSUM_NONE and by default csum_level = 0 */
- skb->ip_summed = CHECKSUM_NONE;
-
- decoded = libie_rx_pt_parse(ptype);
if (!libeth_rx_pt_has_checksum(ring->netdev, decoded))
- return;
+ goto checksum_none;

rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);
-
if ((ring->flags & ICE_RX_FLAGS_RING_GCS) &&
rx_desc->wb.rxdid == ICE_RXDID_FLEX_NIC &&
(decoded.inner_prot == LIBETH_RX_PT_INNER_TCP ||
decoded.inner_prot == LIBETH_RX_PT_INNER_UDP ||
decoded.inner_prot == LIBETH_RX_PT_INNER_ICMP)) {
- ice_rx_gcs(skb, rx_desc);
+ const struct ice_32b_rx_flex_desc_nic *desc;
+ __wsum wcsum;
+ u16 csum;
+
+ desc = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
+ *ip_summed = XDP_CHECKSUM_COMPLETE;
+ csum = (__force u16)desc->raw_csum;
+ wcsum = csum_unfold((__force __sum16)swab16(csum));
+ *cksum_meta = (__force u32)wcsum;
return;
}

/* check if HW has decoded the packet and checksum */
if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
- return;
+ goto checksum_none;

ipv4 = libeth_rx_pt_get_ip_ver(decoded) == LIBETH_RX_PT_OUTER_IPV4;
ipv6 = libeth_rx_pt_get_ip_ver(decoded) == LIBETH_RX_PT_OUTER_IPV6;

if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S)))) {
ring->vsi->back->hw_rx_eipe_error++;
- return;
+ goto checksum_none;
}

if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S))))
@@ -167,14 +145,45 @@ ice_rx_csum(struct ice_rx_ring *ring, struct sk_buff *skb,
* we need to bump the checksum level by 1 to reflect the fact that
* we are indicating we validated the inner checksum.
*/
- if (decoded.tunnel_type >= LIBETH_RX_PT_TUNNEL_IP_GRENAT)
- skb->csum_level = 1;
-
- skb->ip_summed = CHECKSUM_UNNECESSARY;
+ *cksum_meta = decoded.tunnel_type >= LIBETH_RX_PT_TUNNEL_IP_GRENAT;
+ *ip_summed = XDP_CHECKSUM_UNNECESSARY;
return;

checksum_fail:
ring->vsi->back->hw_csum_rx_error++;
+checksum_none:
+ *ip_summed = XDP_CHECKSUM_NONE;
+ *cksum_meta = 0;
+}
+
+/**
+ * ice_rx_csum - Indicate in skb if checksum is good
+ * @ring: the ring we care about
+ * @skb: skb currently being received and modified
+ * @rx_desc: the receive descriptor
+ * @ptype: the packet type decoded by hardware
+ *
+ * skb->protocol must be set before this function is called
+ */
+static void
+ice_rx_csum(struct ice_rx_ring *ring, struct sk_buff *skb,
+ union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
+{
+ enum xdp_checksum ip_summed;
+ u32 cksum_meta;
+
+ ice_get_rx_csum(rx_desc, ptype, ring, &ip_summed, &cksum_meta);
+ switch (ip_summed) {
+ case XDP_CHECKSUM_UNNECESSARY:
+ skb->csum_level = cksum_meta;
+ break;
+ case XDP_CHECKSUM_COMPLETE:
+ skb->csum = (__force __wsum)cksum_meta;
+ break;
+ default:
+ break;
+ }
+ skb->ip_summed = ip_summed;
}

/**
@@ -569,6 +578,30 @@ static int ice_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
return 0;
}

+/**
+ * ice_xdp_rx_checksum - RX checksum XDP hint handler
+ * @ctx: XDP buff pointer
+ * @ip_summed: RX checksum result destination address
+ * @cksum_meta: XDP RX checksum metadata destination address
+ *
+ * Copy RX checksum result (if available) and its metadata to the
+ * destination address.
+ */
+static int ice_xdp_rx_checksum(const struct xdp_md *ctx,
+ enum xdp_checksum *ip_summed,
+ u32 *cksum_meta)
+{
+ const struct libeth_xdp_buff *xdp_ext = (void *)ctx;
+ const union ice_32b_rx_flex_desc *rx_desc = xdp_ext->desc;
+ struct ice_rx_ring *ring;
+
+ ring = libeth_xdp_buff_to_rq(xdp_ext, typeof(*ring), xdp_rxq);
+ ice_get_rx_csum(rx_desc, ice_get_ptype(rx_desc), ring, ip_summed,
+ cksum_meta);
+
+ return 0;
+}
+
/**
* ice_xdp_rx_vlan_tag - VLAN tag XDP hint handler
* @ctx: XDP buff pointer
@@ -601,4 +634,5 @@ const struct xdp_metadata_ops ice_xdp_md_ops = {
.xmo_rx_timestamp = ice_xdp_rx_hw_ts,
.xmo_rx_hash = ice_xdp_rx_hash,
.xmo_rx_vlan_tag = ice_xdp_rx_vlan_tag,
+ .xmo_rx_checksum = ice_xdp_rx_checksum,
};

--
2.53.0