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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich , Jonathan Corbet , Jesper Dangaard Brouer , Ilias Apalodimas , Willem de Bruijn , Kuniyuki Iwashima , Joshua Washington , Harshitha Ramamurthy , Saeed Mahameed , Tariq Toukan , Tony Nguyen , Przemek Kitszel , Alexander Lobakin , Michael Chan , Pavan Chebbi , iommu@lists.linux.dev, netdev@vger.kernel.org, linux-mm@kvack.org, driver-core@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Luigi Rizzo Content-Type: text/plain; charset="UTF-8" When dev->dma_pmd_tx_hdrs is enabled, allocate a MAX_TCP_HEADER bounce buffer per TX ring slot out of the DMA_PMD arena. When the linear portion of a transmitted packet is at most MAX_TCP_HEADER bytes, copy it into the pre-mapped bounce buffer instead of calling dma_map_single()/dma_unmap_single() on every packet. Signed-off-by: Luigi Rizzo --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 45 ++++++++++++++++++----- drivers/net/ethernet/broadcom/bnxt/bnxt.h | 2 + 2 files changed, 37 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index d7728d0c5b6e6..b9c91eb3aaddd 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -680,13 +680,22 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) length = BNXT_MIN_PKT_SIZE; } - mapping = dma_map_single(&pdev->dev, skb->data, len, DMA_TO_DEVICE); - - if (unlikely(dma_mapping_error(&pdev->dev, mapping))) - goto tx_free; - - dma_unmap_addr_set(tx_buf, mapping, mapping); - dma_unmap_len_set(tx_buf, len, len); + if (txr->tx_hdr_bufs && len + pad <= MAX_TCP_HEADER) { + u32 off = RING_TX(bp, prod) * MAX_TCP_HEADER; + + memcpy(txr->tx_hdr_bufs + off, skb->data, len); + if (pad && !last_frag) + memset(txr->tx_hdr_bufs + off + len, 0, pad); + mapping = txr->tx_hdr_bufs_dma + off; + dma_unmap_len_set(tx_buf, len, 0); + } else { + mapping = dma_map_single(&pdev->dev, skb->data, len, + DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(&pdev->dev, mapping))) + goto tx_free; + dma_unmap_addr_set(tx_buf, mapping, mapping); + dma_unmap_len_set(tx_buf, len, len); + } flags = (len << TX_BD_LEN_SHIFT) | TX_BD_TYPE_LONG_TX_BD | TX_BD_CNT(last_frag + 2); @@ -800,8 +809,9 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) /* start back at beginning and unmap skb */ prod = txr->tx_prod; tx_buf = &txr->tx_buf_ring[RING_TX(bp, prod)]; - dma_unmap_single(&pdev->dev, dma_unmap_addr(tx_buf, mapping), - skb_headlen(skb), DMA_TO_DEVICE); + if (dma_unmap_len(tx_buf, len)) + dma_unmap_single(&pdev->dev, dma_unmap_addr(tx_buf, mapping), + skb_headlen(skb), DMA_TO_DEVICE); prod = NEXT_TX(prod); /* unmap remaining mapped pages */ @@ -885,7 +895,6 @@ static bool __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr, dma_unmap_single(&pdev->dev, dma_addr, dma_len, DMA_TO_DEVICE); } - last = tx_buf->nr_frags; for (j = 0; j < last; j++) { @@ -4111,6 +4120,15 @@ static void bnxt_free_tx_rings(struct bnxt *bp) ring = &txr->tx_ring_struct; + if (txr->tx_hdr_bufs) { + dma_free_coherent(&pdev->dev, + ring->ring_mem.nr_pages * + TX_DESC_CNT * MAX_TCP_HEADER, + txr->tx_hdr_bufs, + txr->tx_hdr_bufs_dma); + txr->tx_hdr_bufs = NULL; + } + bnxt_free_ring(bp, &ring->ring_mem); } } @@ -4181,6 +4199,13 @@ static int bnxt_alloc_tx_rings(struct bnxt *bp) if (rc) return rc; } + if (pdev->dev.dma_pmd_tx_hdrs && i >= bp->tx_nr_rings_xdp) + txr->tx_hdr_bufs = + dma_alloc_coherent(&pdev->dev, + ring->ring_mem.nr_pages * + TX_DESC_CNT * MAX_TCP_HEADER, + &txr->tx_hdr_bufs_dma, + GFP_KERNEL | __GFP_NOWARN); qidx = bp->tc_to_qidx[j]; ring->queue_id = bp->q_info[qidx].queue_id; spin_lock_init(&txr->xdp_tx_lock); diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index c673b2ce4a0d2..b42bbabc0eb98 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -1003,6 +1003,8 @@ struct bnxt_tx_ring_info { struct tx_push_buffer *tx_push; dma_addr_t tx_push_mapping; __le64 data_mapping; + void *tx_hdr_bufs; + dma_addr_t tx_hdr_bufs_dma; void *tx_inline_buf; dma_addr_t tx_inline_dma; -- 2.56.0.rc1.315.gc6ed9934b7-goog