[PATCH net-next v4 18/33] nfp: add XDP frame size to netronome driver

Jesper Dangaard Brouer
2020-05-14T10:50:47Z

The netronome nfp driver use PAGE_SIZE when xdp_prog is set, but
xdp.data_hard_start begins at offset NFP_NET_RX_BUF_HEADROOM.
Thus, adjust for this when setting xdp.frame_sz, as it counts
from data_hard_start.

When doing XDP_TX this driver is smart and instead of a full DMA-map
does a DMA-sync on with packet length. As xdp_adjust_tail can now
grow packet length, add checks to make sure that grow size is within
the DMA-mapped size.

Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
---
.../net/ethernet/netronome/nfp/nfp_net_common.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 9bfb3b077bc1..0e0cc3d58bdc 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1741,10 +1741,15 @@ nfp_net_tx_xdp_buf(struct nfp_net_dp *dp, struct nfp_net_rx_ring *rx_ring,
struct nfp_net_rx_buf *rxbuf, unsigned int dma_off,
unsigned int pkt_len, bool *completed)
{
+ unsigned int dma_map_sz = dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA;
struct nfp_net_tx_buf *txbuf;
struct nfp_net_tx_desc *txd;
int wr_idx;

+ /* Reject if xdp_adjust_tail grow packet beyond DMA area */
+ if (pkt_len + dma_off > dma_map_sz)
+ return false;
+
if (unlikely(nfp_net_tx_full(tx_ring, 1))) {
if (!*completed) {
nfp_net_xdp_complete(tx_ring);
@@ -1817,6 +1822,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
rcu_read_lock();
xdp_prog = READ_ONCE(dp->xdp_prog);
true_bufsz = xdp_prog ? PAGE_SIZE : dp->fl_bufsz;
+ xdp.frame_sz = PAGE_SIZE - NFP_NET_RX_BUF_HEADROOM;
xdp.rxq = &rx_ring->xdp_rxq;
tx_ring = r_vec->xdp_ring;