Commit c1ece6b2 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by Alexei Starovoitov
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bpf/xdp: devmap can avoid calling ndo_xdp_flush 



The XDP_REDIRECT map devmap can avoid using ndo_xdp_flush, by instead
instructing ndo_xdp_xmit to flush via XDP_XMIT_FLUSH flag in
appropriate places.

Notice after this patch it is possible to remove ndo_xdp_flush
completely, as this is the last user of ndo_xdp_flush. This is left
for later patches, to keep driver changes separate.

Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 1e67575a

kernel/bpf/devmap.c

+6 −13
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ void __dev_map_insert_ctx(struct bpf_map *map, u32 bit) 
}



static int bq_xmit_all(struct bpf_dtab_netdev *obj,

			 struct xdp_bulk_queue *bq)

		       struct xdp_bulk_queue *bq, u32 flags)

{

	struct net_device *dev = obj->dev;

	int sent = 0, drops = 0, err = 0;
@@ -232,7 +232,7 @@ static int bq_xmit_all(struct bpf_dtab_netdev *obj, 
		prefetch(xdpf);

	}



	sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, 0);

	sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, flags);

	if (sent < 0) {

		err = sent;

		sent = 0;
@@ -276,7 +276,6 @@ void __dev_map_flush(struct bpf_map *map) 
	for_each_set_bit(bit, bitmap, map->max_entries) {

		struct bpf_dtab_netdev *dev = READ_ONCE(dtab->netdev_map[bit]);

		struct xdp_bulk_queue *bq;

		struct net_device *netdev;



		/* This is possible if the dev entry is removed by user space

		 * between xdp redirect and flush op.
@@ -287,10 +286,7 @@ void __dev_map_flush(struct bpf_map *map) 
		__clear_bit(bit, bitmap);



		bq = this_cpu_ptr(dev->bulkq);

		bq_xmit_all(dev, bq);

		netdev = dev->dev;

		if (likely(netdev->netdev_ops->ndo_xdp_flush))

			netdev->netdev_ops->ndo_xdp_flush(netdev);

		bq_xmit_all(dev, bq, XDP_XMIT_FLUSH);

	}

}
@@ -320,7 +316,7 @@ static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf, 
	struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq);



	if (unlikely(bq->count == DEV_MAP_BULK_SIZE))

		bq_xmit_all(obj, bq);

		bq_xmit_all(obj, bq, 0);



	/* Ingress dev_rx will be the same for all xdp_frame's in

	 * bulk_queue, because bq stored per-CPU and must be flushed
@@ -359,8 +355,7 @@ static void *dev_map_lookup_elem(struct bpf_map *map, void *key) 


static void dev_map_flush_old(struct bpf_dtab_netdev *dev)

{

	if (dev->dev->netdev_ops->ndo_xdp_flush) {

		struct net_device *fl = dev->dev;

	if (dev->dev->netdev_ops->ndo_xdp_xmit) {

		struct xdp_bulk_queue *bq;

		unsigned long *bitmap;
@@ -371,9 +366,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev) 
			__clear_bit(dev->bit, bitmap);



			bq = per_cpu_ptr(dev->bulkq, cpu);

			bq_xmit_all(dev, bq);



			fl->netdev_ops->ndo_xdp_flush(dev->dev);

			bq_xmit_all(dev, bq, XDP_XMIT_FLUSH);

		}

	}

}

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