[PATCH v9 bpf-next 03/14] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer

Lorenzo Bianconi
2021-06-14T12:50:48Z

Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and
XDP remote drivers if this is a "non-linear" XDP buffer. Access
xdp_shared_info only if xdp_buff mb is set.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
drivers/net/ethernet/marvell/mvneta.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 7d5cd9bc6c99..f8993f7488b9 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2041,9 +2041,14 @@ mvneta_xdp_put_buff(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
{
int i;

+ if (likely(!xdp_buff_is_mb(xdp)))
+ goto out;
+
for (i = 0; i < sinfo->nr_frags; i++)
page_pool_put_full_page(rxq->page_pool,
skb_frag_page(&sinfo->frags[i]), true);
+
+out:
page_pool_put_page(rxq->page_pool, virt_to_head_page(xdp->data),
sync_len, true);
}
@@ -2245,7 +2250,6 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
int data_len = -MVNETA_MH_SIZE, len;
struct net_device *dev = pp->dev;
enum dma_data_direction dma_dir;
- struct skb_shared_info *sinfo;

if (*size > MVNETA_MAX_RX_BUF_SIZE) {
len = MVNETA_MAX_RX_BUF_SIZE;
@@ -2267,9 +2271,6 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
prefetch(data);
xdp_prepare_buff(xdp, data, pp->rx_offset_correction + MVNETA_MH_SIZE,
data_len, false);
-
- sinfo = xdp_get_shared_info_from_buff(xdp);
- sinfo->nr_frags = 0;
}

static void
@@ -2304,12 +2305,18 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
skb_frag_size_set(frag, data_len);
__skb_frag_set_page(frag, page);

+ if (!xdp_buff_is_mb(xdp)) {
+ xdp_sinfo->data_len = *size;
+ xdp_buff_set_mb(xdp);
+ }
/* last fragment */
if (len == *size) {
struct skb_shared_info *sinfo;

sinfo = xdp_get_shared_info_from_buff(xdp);
sinfo->nr_frags = xdp_sinfo->nr_frags;
+ sinfo->data_len = xdp_sinfo->data_len;
+
memcpy(sinfo->frags, xdp_sinfo->frags,
sinfo->nr_frags * sizeof(skb_frag_t));
}
@@ -2324,9 +2331,12 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
struct xdp_buff *xdp, u32 desc_status)
{
struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
- int i, num_frags = sinfo->nr_frags;
+ int i, num_frags = 0;
struct sk_buff *skb;

+ if (unlikely(xdp_buff_is_mb(xdp)))
+ num_frags = sinfo->nr_frags;
+
skb = build_skb(xdp->data_hard_start, PAGE_SIZE);
if (!skb)
return ERR_PTR(-ENOMEM);
@@ -2398,6 +2408,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
frame_sz = size - ETH_FCS_LEN;
desc_status = rx_status;

+ xdp_buff_clear_mb(&xdp_buf);
mvneta_swbm_rx_frame(pp, rx_desc, rxq, &xdp_buf,
&size, page);
} else {
--
2.31.1