Meaning of data_len and meta_len RX WB descriptor fields depend
slightly on whether rx_offset is dynamic or not. For dynamic
offsets data_len includes meta_len. This makes the code harder
to follow, in fact our RX buffer length check is incorrect -
we are comparing allocation length to data_len while we should
also account for meta_len.
Let's adjust the values of data_len and meta_len to their natural
meaning and simplify the logic.
Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Rolf Neugebauer <rolf.neugeba...@netronome.com>
---
drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 553ae64e2f7f..070645f9bc21 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1259,22 +1259,19 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring,
int budget)
meta_len = rxd->rxd.meta_len_dd & PCIE_DESC_RX_META_LEN_MASK;
data_len = le16_to_cpu(rxd->rxd.data_len);
+ /* For dynamic offset data_len includes meta_len, adjust */
+ if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
+ data_len -= meta_len;
+ else
+ meta_len = nn->rx_offset;
- if (WARN_ON_ONCE(data_len > nn->fl_bufsz)) {
+ if (WARN_ON_ONCE(meta_len + data_len > nn->fl_bufsz)) {
dev_kfree_skb_any(skb);
continue;
}
- if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC) {
- /* The packet data starts after the metadata */
- skb_reserve(skb, meta_len);
- } else {
- /* The packet data starts at a fixed offset */
- skb_reserve(skb, nn->rx_offset);
- }
-
- /* Adjust the SKB for the dynamic meta data pre-pended */
- skb_put(skb, data_len - meta_len);
+ skb_reserve(skb, meta_len);
+ skb_put(skb, data_len);
nfp_net_set_hash(nn->netdev, skb, rxd);
--
1.9.1
