From 9e5269a915a8e3d6f4bae5641451737e9cca70c0 Mon Sep 17 00:00:00 2001 From: Shay Agroskin Date: Tue, 8 Jun 2021 19:01:12 +0300 Subject: [PATCH] net: ena: use build_skb() in RX path This patch converts the RX path to use build_skb() for packets larger than copybreak (set to 256 by default). This function makes the first descriptor's page to be the linear part of the sk_buff struct buffer. Also remove the SKB description from the README since most of it no longer relevant and the parts that are left don't add information. Signed-off-by: Shay Agroskin Signed-off-by: David S. Miller --- drivers/net/ethernet/amazon/ena/ena_netdev.c | 66 +++++++++++++++++----------- 1 file changed, 41 insertions(+), 25 deletions(-) diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index b613067a06d8..d7bc4f45e5df 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -529,7 +529,7 @@ static void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter, rx_ring->rx_headroom = XDP_PACKET_HEADROOM; } else { ena_xdp_unregister_rxq_info(rx_ring); - rx_ring->rx_headroom = 0; + rx_ring->rx_headroom = NET_SKB_PAD; } } } @@ -720,6 +720,7 @@ static void ena_init_io_rings(struct ena_adapter *adapter, rxr->smoothed_interval = ena_com_get_nonadaptive_moderation_interval_rx(ena_dev); rxr->empty_rx_queue = 0; + rxr->rx_headroom = NET_SKB_PAD; adapter->ena_napi[i].dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE; rxr->xdp_ring = &adapter->tx_ring[i + adapter->num_io_queues]; } @@ -982,6 +983,7 @@ static int ena_alloc_rx_page(struct ena_ring *rx_ring, struct ena_com_buf *ena_buf; struct page *page; dma_addr_t dma; + int tailroom; /* restore page offset value in case it has been changed by device */ rx_info->page_offset = headroom; @@ -1012,10 +1014,12 @@ static int ena_alloc_rx_page(struct ena_ring *rx_ring, netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev, "Allocate page %p, rx_info %p\n", page, rx_info); + tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + rx_info->page = page; ena_buf = &rx_info->ena_buf; ena_buf->paddr = dma + headroom; - ena_buf->len = ENA_PAGE_SIZE - headroom; + ena_buf->len = ENA_PAGE_SIZE - headroom - tailroom; return 0; } @@ -1381,21 +1385,23 @@ static int ena_clean_tx_irq(struct ena_ring *tx_ring, u32 budget) return tx_pkts; } -static struct sk_buff *ena_alloc_skb(struct ena_ring *rx_ring, bool frags) +static struct sk_buff *ena_alloc_skb(struct ena_ring *rx_ring, void *first_frag) { struct sk_buff *skb; - if (frags) - skb = napi_get_frags(rx_ring->napi); - else + if (!first_frag) skb = netdev_alloc_skb_ip_align(rx_ring->netdev, rx_ring->rx_copybreak); + else + skb = build_skb(first_frag, ENA_PAGE_SIZE); if (unlikely(!skb)) { ena_increase_stat(&rx_ring->rx_stats.skb_alloc_fail, 1, &rx_ring->syncp); + netif_dbg(rx_ring->adapter, rx_err, rx_ring->netdev, - "Failed to allocate skb. frags: %d\n", frags); + "Failed to allocate skb. first_frag %s\n", + first_frag ? "provided" : "not provided"); return NULL; } @@ -1410,7 +1416,9 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, struct sk_buff *skb; struct ena_rx_buffer *rx_info; u16 len, req_id, buf = 0; - void *va; + void *page_addr; + u32 page_offset; + void *data_addr; len = ena_bufs[buf].len; req_id = ena_bufs[buf].req_id; @@ -1428,12 +1436,14 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, rx_info, rx_info->page); /* save virt address of first buffer */ - va = page_address(rx_info->page) + rx_info->page_offset; + page_addr = page_address(rx_info->page); + page_offset = rx_info->page_offset; + data_addr = page_addr + page_offset; - prefetch(va); + prefetch(data_addr); if (len <= rx_ring->rx_copybreak) { - skb = ena_alloc_skb(rx_ring, false); + skb = ena_alloc_skb(rx_ring, NULL); if (unlikely(!skb)) return NULL; @@ -1446,7 +1456,7 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, dma_unmap_addr(&rx_info->ena_buf, paddr), len, DMA_FROM_DEVICE); - skb_copy_to_linear_data(skb, va, len); + skb_copy_to_linear_data(skb, data_addr, len); dma_sync_single_for_device(rx_ring->dev, dma_unmap_addr(&rx_info->ena_buf, paddr), len, @@ -1460,16 +1470,18 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, return skb; } - skb = ena_alloc_skb(rx_ring, true); + ena_unmap_rx_buff(rx_ring, rx_info); + + skb = ena_alloc_skb(rx_ring, page_addr); if (unlikely(!skb)) return NULL; - do { - ena_unmap_rx_buff(rx_ring, rx_info); - - skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page, - rx_info->page_offset, len, ENA_PAGE_SIZE); + /* Populate skb's linear part */ + skb_reserve(skb, page_offset); + skb_put(skb, len); + skb->protocol = eth_type_trans(skb, rx_ring->netdev); + do { netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev, "RX skb updated. len %d. data_len %d\n", skb->len, skb->data_len); @@ -1488,6 +1500,12 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, req_id = ena_bufs[buf].req_id; rx_info = &rx_ring->rx_buffer_info[req_id]; + + ena_unmap_rx_buff(rx_ring, rx_info); + + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page, + rx_info->page_offset, len, ENA_PAGE_SIZE); + } while (1); return skb; @@ -1700,14 +1718,12 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, skb_record_rx_queue(skb, rx_ring->qid); - if (rx_ring->ena_bufs[0].len <= rx_ring->rx_copybreak) { - total_len += rx_ring->ena_bufs[0].len; + if (rx_ring->ena_bufs[0].len <= rx_ring->rx_copybreak) rx_copybreak_pkt++; - napi_gro_receive(napi, skb); - } else { - total_len += skb->len; - napi_gro_frags(napi); - } + + total_len += skb->len; + + napi_gro_receive(napi, skb); res_budget--; } while (likely(res_budget)); -- 2.11.0