Commit 1396d314 authored by Shay Agroskin's avatar Shay Agroskin Committed by Jakub Kicinski
Browse files

net: ena: fix packet's addresses for rx_offset feature 



This patch fixes two lines in which the rx_offset received by the device
wasn't taken into account:

- prefetch function:
	In our driver the copied data would reside in
	rx_info->page + rx_headroom + rx_offset

	so the prefetch function is changed accordingly.

- setting page_offset to zero for descriptors > 1:
	for every descriptor but the first, the rx_offset is zero. Hence
	the page_offset value should be set to rx_headroom.

	The previous implementation changed the value of rx_info after
	the descriptor was added to the SKB (essentially providing wrong
	page offset).

Fixes: 68f236df ("net: ena: add support for the rx offset feature")
Signed-off-by: default avatarShay Agroskin <shayagr@amazon.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 09323b3b

drivers/net/ethernet/amazon/ena/ena_netdev.c

+11 −9
Original line number Diff line number Diff line
@@ -908,10 +908,14 @@ static void ena_free_all_io_rx_resources(struct ena_adapter *adapter) 
static int ena_alloc_rx_page(struct ena_ring *rx_ring,

				    struct ena_rx_buffer *rx_info, gfp_t gfp)

{

	int headroom = rx_ring->rx_headroom;

	struct ena_com_buf *ena_buf;

	struct page *page;

	dma_addr_t dma;



	/* restore page offset value in case it has been changed by device */

	rx_info->page_offset = headroom;



	/* if previous allocated page is not used */

	if (unlikely(rx_info->page))

		return 0;
@@ -941,10 +945,9 @@ static int ena_alloc_rx_page(struct ena_ring *rx_ring, 
		  "Allocate page %p, rx_info %p\n", page, rx_info);



	rx_info->page = page;

	rx_info->page_offset = 0;

	ena_buf = &rx_info->ena_buf;

	ena_buf->paddr = dma + rx_ring->rx_headroom;

	ena_buf->len = ENA_PAGE_SIZE - rx_ring->rx_headroom;

	ena_buf->paddr = dma + headroom;

	ena_buf->len = ENA_PAGE_SIZE - headroom;



	return 0;

}
@@ -1356,7 +1359,8 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, 


	/* save virt address of first buffer */

	va = page_address(rx_info->page) + rx_info->page_offset;

	prefetch(va + NET_IP_ALIGN);



	prefetch(va);



	if (len <= rx_ring->rx_copybreak) {

		skb = ena_alloc_skb(rx_ring, false);
@@ -1397,8 +1401,6 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, 


		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page,

				rx_info->page_offset, len, ENA_PAGE_SIZE);

		/* The offset is non zero only for the first buffer */

		rx_info->page_offset = 0;



		netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,

			  "RX skb updated. len %d. data_len %d\n",
@@ -1517,8 +1519,7 @@ static int ena_xdp_handle_buff(struct ena_ring *rx_ring, struct xdp_buff *xdp) 
	int ret;



	rx_info = &rx_ring->rx_buffer_info[rx_ring->ena_bufs[0].req_id];

	xdp->data = page_address(rx_info->page) +

		rx_info->page_offset + rx_ring->rx_headroom;

	xdp->data = page_address(rx_info->page) + rx_info->page_offset;

	xdp_set_data_meta_invalid(xdp);

	xdp->data_hard_start = page_address(rx_info->page);

	xdp->data_end = xdp->data + rx_ring->ena_bufs[0].len;
@@ -1585,8 +1586,9 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, 
		if (unlikely(ena_rx_ctx.descs == 0))

			break;



		/* First descriptor might have an offset set by the device */

		rx_info = &rx_ring->rx_buffer_info[rx_ring->ena_bufs[0].req_id];

		rx_info->page_offset = ena_rx_ctx.pkt_offset;

		rx_info->page_offset += ena_rx_ctx.pkt_offset;



		netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,

			  "rx_poll: q %d got packet from ena. descs #: %d l3 proto %d l4 proto %d hash: %x\n",

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