net: marvell: rely on xdp_update_skb_shared_info utility routine

Rely on xdp_update_skb_shared_info routine in order to avoid
resetting frags array in skb_shared_info structure building
the skb in mvneta_swbm_build_skb(). Frags array is expected to
be initialized by the receiving driver building the xdp_buff
and here we just need to update memory metadata.

Acked-by: Toke Hoiland-Jorgensen <[email protected]>
Acked-by: John Fastabend <[email protected]>
Signed-off-by: Lorenzo Bianconi <[email protected]>
Link: https://lore.kernel.org/r/e0dad97f5d02b13f189f99f1e5bc8e61bef73412.1642758637.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <[email protected]>

Author: LorenzoBianconi

drivers/net/ethernet/marvell/mvneta.c

@@ -2332,8 +2332,12 @@ 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_has_frags(xdp))
+		if (!xdp_buff_has_frags(xdp)) {
+			sinfo->xdp_frags_size = *size;
 			xdp_buff_set_frags_flag(xdp);
+		}
+		if (page_is_pfmemalloc(page))
+			xdp_buff_set_frag_pfmemalloc(xdp);
 	} else {
 		page_pool_put_full_page(rxq->page_pool, page, true);
 	}
@@ -2347,7 +2351,6 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
 	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 	struct sk_buff *skb;
 	u8 num_frags;
-	int i;
 
 	if (unlikely(xdp_buff_has_frags(xdp)))
 		num_frags = sinfo->nr_frags;
@@ -2362,18 +2365,12 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
 	skb_put(skb, xdp->data_end - xdp->data);
 	skb->ip_summed = mvneta_rx_csum(pp, desc_status);
 
-	if (likely(!xdp_buff_has_frags(xdp)))
-		goto out;
-
-	for (i = 0; i < num_frags; i++) {
-		skb_frag_t *frag = &sinfo->frags[i];
-
-		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
-				skb_frag_page(frag), skb_frag_off(frag),
-				skb_frag_size(frag), PAGE_SIZE);
-	}
+	if (unlikely(xdp_buff_has_frags(xdp)))
+		xdp_update_skb_shared_info(skb, num_frags,
+					   sinfo->xdp_frags_size,
+					   num_frags * xdp->frame_sz,
+					   xdp_buff_is_frag_pfmemalloc(xdp));
 
-out:
 	return skb;
 }