Commit c7030d14 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Jakub Kicinski
Browse files

net: ethernet: enetc: do not always access skb_shared_info in the XDP path 



Move XDP skb_shared_info structure initialization in from
enetc_map_rx_buff_to_xdp() to enetc_add_rx_buff_to_xdp() and do not always
access skb_shared_info in the xdp_buff/xdp_frame since it is located in a
different cacheline with respect to hard_start and data xdp pointers.
Rely on XDP_FLAGS_HAS_FRAGS flag to check if it really necessary to access
non-linear part of the xdp_buff/xdp_frame.

Reviewed-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 59cc773a

drivers/net/ethernet/freescale/enetc/enetc.c

+8 −6
Original line number Diff line number Diff line
@@ -1305,6 +1305,10 @@ static int enetc_xdp_frame_to_xdp_tx_swbd(struct enetc_bdr *tx_ring, 
	xdp_tx_swbd->xdp_frame = NULL;



	n++;



	if (!xdp_frame_has_frags(xdp_frame))

		goto out;



	xdp_tx_swbd = &xdp_tx_arr[n];



	shinfo = xdp_get_shared_info_from_frame(xdp_frame);
@@ -1334,7 +1338,7 @@ static int enetc_xdp_frame_to_xdp_tx_swbd(struct enetc_bdr *tx_ring, 
		n++;

		xdp_tx_swbd = &xdp_tx_arr[n];

	}



out:

	xdp_tx_arr[n - 1].is_eof = true;

	xdp_tx_arr[n - 1].xdp_frame = xdp_frame;
@@ -1390,16 +1394,12 @@ static void enetc_map_rx_buff_to_xdp(struct enetc_bdr *rx_ring, int i, 
{

	struct enetc_rx_swbd *rx_swbd = enetc_get_rx_buff(rx_ring, i, size);

	void *hard_start = page_address(rx_swbd->page) + rx_swbd->page_offset;

	struct skb_shared_info *shinfo;



	/* To be used for XDP_TX */

	rx_swbd->len = size;



	xdp_prepare_buff(xdp_buff, hard_start - rx_ring->buffer_offset,

			 rx_ring->buffer_offset, size, false);



	shinfo = xdp_get_shared_info_from_buff(xdp_buff);

	shinfo->nr_frags = 0;

}



static void enetc_add_rx_buff_to_xdp(struct enetc_bdr *rx_ring, int i,
@@ -1407,7 +1407,7 @@ static void enetc_add_rx_buff_to_xdp(struct enetc_bdr *rx_ring, int i, 
{

	struct skb_shared_info *shinfo = xdp_get_shared_info_from_buff(xdp_buff);

	struct enetc_rx_swbd *rx_swbd = enetc_get_rx_buff(rx_ring, i, size);

	skb_frag_t *frag = &shinfo->frags[shinfo->nr_frags];

	skb_frag_t *frag;



	/* To be used for XDP_TX */

	rx_swbd->len = size;
@@ -1415,6 +1415,7 @@ static void enetc_add_rx_buff_to_xdp(struct enetc_bdr *rx_ring, int i, 
	if (!xdp_buff_has_frags(xdp_buff)) {

		xdp_buff_set_frags_flag(xdp_buff);

		shinfo->xdp_frags_size = size;

		shinfo->nr_frags = 0;

	} else {

		shinfo->xdp_frags_size += size;

	}
@@ -1422,6 +1423,7 @@ static void enetc_add_rx_buff_to_xdp(struct enetc_bdr *rx_ring, int i, 
	if (page_is_pfmemalloc(rx_swbd->page))

		xdp_buff_set_frag_pfmemalloc(xdp_buff);



	frag = &shinfo->frags[shinfo->nr_frags];

	skb_frag_off_set(frag, rx_swbd->page_offset);

	skb_frag_size_set(frag, size);

	__skb_frag_set_page(frag, rx_swbd->page);