From b605a84a74170d2a07f53512cd57cd564db77249 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sun, 22 Jul 2018 13:07:29 +0200 Subject: [PATCH] ramips: ethernet: unify tx descriptor buffer splitting A buffer is split into multiple descriptors if it exceeds 16 KB. Apply the same split for the skb head as well (to deal with corner cases on fraglist support) Signed-off-by: Felix Fietkau --- .../net/ethernet/mediatek/mtk_eth_soc.c | 158 +++++++++--------- 1 file changed, 83 insertions(+), 75 deletions(-) diff --git a/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/mtk_eth_soc.c index 8bf17f629c..e0bc0ab818 100644 --- a/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -565,40 +565,82 @@ static inline u32 fe_empty_txd(struct fe_tx_ring *ring) (ring->tx_ring_size - 1))); } -static int fe_tx_dma_map_page(struct device *dev, struct fe_tx_buf *tx_buf, - struct fe_tx_dma *txd, int idx, - struct page *page, size_t offset, size_t size) +struct fe_map_state { + struct device *dev; + struct fe_tx_dma txd; + u32 def_txd4; + int ring_idx; + int i; +}; + +static void fe_tx_dma_write_desc(struct fe_tx_ring *ring, struct fe_map_state *st) { + fe_set_txd(&st->txd, &ring->tx_dma[st->ring_idx]); + memset(&st->txd, 0, sizeof(st->txd)); + st->txd.txd4 = st->def_txd4; + st->ring_idx = NEXT_TX_DESP_IDX(st->ring_idx); +} + +static int __fe_tx_dma_map_page(struct fe_tx_ring *ring, struct fe_map_state *st, + struct page *page, size_t offset, size_t size) +{ + struct device *dev = st->dev; + struct fe_tx_buf *tx_buf; dma_addr_t mapped_addr; mapped_addr = dma_map_page(dev, page, offset, size, DMA_TO_DEVICE); if (unlikely(dma_mapping_error(dev, mapped_addr))) return -EIO; - if (idx & 1) { - txd->txd3 = mapped_addr; - txd->txd2 |= TX_DMA_PLEN1(size); + if (st->i && !(st->i & 1)) + fe_tx_dma_write_desc(ring, st); + + tx_buf = &ring->tx_buf[st->ring_idx]; + if (st->i & 1) { + st->txd.txd3 = mapped_addr; + st->txd.txd2 |= TX_DMA_PLEN1(size); dma_unmap_addr_set(tx_buf, dma_addr1, mapped_addr); dma_unmap_len_set(tx_buf, dma_len1, size); } else { tx_buf->skb = (struct sk_buff *)DMA_DUMMY_DESC; - txd->txd1 = mapped_addr; - txd->txd2 = TX_DMA_PLEN0(size); + st->txd.txd1 = mapped_addr; + st->txd.txd2 = TX_DMA_PLEN0(size); dma_unmap_addr_set(tx_buf, dma_addr0, mapped_addr); dma_unmap_len_set(tx_buf, dma_len0, size); } + st->i++; + return 0; } -static int fe_tx_dma_map_skb(struct device *dev, struct fe_tx_buf *tx_buf, - struct fe_tx_dma *txd, int idx, +static int fe_tx_dma_map_page(struct fe_tx_ring *ring, struct fe_map_state *st, + struct page *page, size_t offset, size_t size) +{ + int cur_size; + int ret; + + while (size > 0) { + cur_size = min_t(size_t, size, TX_DMA_BUF_LEN); + + ret = __fe_tx_dma_map_page(ring, st, page, offset, cur_size); + if (ret) + return ret; + + size -= cur_size; + offset += cur_size; + } + + return 0; +} + +static int fe_tx_dma_map_skb(struct fe_tx_ring *ring, struct fe_map_state *st, struct sk_buff *skb) { struct page *page = virt_to_page(skb->data); size_t offset = offset_in_page(skb->data); size_t size = skb_headlen(skb); - return fe_tx_dma_map_page(dev, tx_buf, txd, idx, page, offset, size); + return fe_tx_dma_map_page(ring, st, page, offset, size); } static inline struct sk_buff * @@ -613,41 +655,39 @@ fe_next_frag(struct sk_buff *head, struct sk_buff *skb) return NULL; } + static int fe_tx_map_dma(struct sk_buff *skb, struct net_device *dev, int tx_num, struct fe_tx_ring *ring) { struct fe_priv *priv = netdev_priv(dev); - struct skb_frag_struct *frag; - struct fe_tx_dma txd, *ptxd; - struct fe_tx_buf *tx_buf; + struct fe_map_state st = { + .dev = &dev->dev, + .ring_idx = ring->tx_next_idx, + }; struct sk_buff *head = skb; + struct fe_tx_buf *tx_buf; unsigned int nr_frags; - u32 def_txd4; - int i, j, k, frag_size, frag_map_size, offset; - - tx_buf = &ring->tx_buf[ring->tx_next_idx]; - memset(tx_buf, 0, sizeof(*tx_buf)); - memset(&txd, 0, sizeof(txd)); + int i, j; /* init tx descriptor */ if (priv->soc->tx_dma) - priv->soc->tx_dma(&txd); + priv->soc->tx_dma(&st.txd); else - txd.txd4 = TX_DMA_DESP4_DEF; - def_txd4 = txd.txd4; + st.txd.txd4 = TX_DMA_DESP4_DEF; + st.def_txd4 = st.txd.txd4; /* TX Checksum offload */ if (skb->ip_summed == CHECKSUM_PARTIAL) - txd.txd4 |= TX_DMA_CHKSUM; + st.txd.txd4 |= TX_DMA_CHKSUM; /* VLAN header offload */ if (skb_vlan_tag_present(skb)) { u16 tag = skb_vlan_tag_get(skb); if (IS_ENABLED(CONFIG_SOC_MT7621)) - txd.txd4 |= TX_DMA_INS_VLAN_MT7621 | tag; + st.txd.txd4 |= TX_DMA_INS_VLAN_MT7621 | tag; else - txd.txd4 |= TX_DMA_INS_VLAN | + st.txd.txd4 |= TX_DMA_INS_VLAN | ((tag >> VLAN_PRIO_SHIFT) << 4) | (tag & 0xF); } @@ -661,75 +701,46 @@ static int fe_tx_map_dma(struct sk_buff *skb, struct net_device *dev, } if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) { - txd.txd4 |= TX_DMA_TSO; + st.txd.txd4 |= TX_DMA_TSO; tcp_hdr(skb)->check = htons(skb_shinfo(skb)->gso_size); } } - k = 0; - j = ring->tx_next_idx; - next_frag: - if (skb_headlen(skb)) { - if (fe_tx_dma_map_skb(&dev->dev, tx_buf, &txd, k++, skb)) - goto err_dma; - } + if (skb_headlen(skb) && fe_tx_dma_map_skb(ring, &st, skb)) + goto err_dma; /* TX SG offload */ nr_frags = skb_shinfo(skb)->nr_frags; for (i = 0; i < nr_frags; i++) { - struct page *page; + struct skb_frag_struct *frag; frag = &skb_shinfo(skb)->frags[i]; - frag_size = skb_frag_size(frag); - offset = frag->page_offset; - page = skb_frag_page(frag); - - while (frag_size > 0) { - frag_map_size = min(frag_size, TX_DMA_BUF_LEN); - if (!(k & 0x1)) { - fe_set_txd(&txd, &ring->tx_dma[j]); - memset(&txd, 0, sizeof(txd)); - txd.txd4 = def_txd4; - j = NEXT_TX_DESP_IDX(j); - tx_buf = &ring->tx_buf[j]; - } - - if (fe_tx_dma_map_page(&dev->dev, tx_buf, &txd, k++, - page, offset, frag_map_size)) - goto err_dma; - - frag_size -= frag_map_size; - offset += frag_map_size; - } + if (fe_tx_dma_map_page(ring, &st, skb_frag_page(frag), + frag->page_offset, skb_frag_size(frag))) + goto err_dma; } skb = fe_next_frag(head, skb); - if (skb) { - if (!(k & 0x1)) { - fe_set_txd(&txd, &ring->tx_dma[j]); - memset(&txd, 0, sizeof(txd)); - txd.txd4 = def_txd4; - j = NEXT_TX_DESP_IDX(j); - tx_buf = &ring->tx_buf[j]; - } + if (skb) goto next_frag; - } /* set last segment */ - if (k & 0x1) - txd.txd2 |= TX_DMA_LS0; + if (st.i & 0x1) + st.txd.txd2 |= TX_DMA_LS0; else - txd.txd2 |= TX_DMA_LS1; - fe_set_txd(&txd, &ring->tx_dma[j]); + st.txd.txd2 |= TX_DMA_LS1; /* store skb to cleanup */ + tx_buf = &ring->tx_buf[st.ring_idx]; tx_buf->skb = head; netdev_sent_queue(dev, head->len); skb_tx_timestamp(head); - ring->tx_next_idx = NEXT_TX_DESP_IDX(j); + fe_tx_dma_write_desc(ring, &st); + ring->tx_next_idx = st.ring_idx; + /* make sure that all changes to the dma ring are flushed before we * continue */ @@ -749,13 +760,10 @@ next_frag: err_dma: j = ring->tx_next_idx; for (i = 0; i < tx_num; i++) { - ptxd = &ring->tx_dma[j]; - tx_buf = &ring->tx_buf[j]; - /* unmap dma */ - fe_txd_unmap(&dev->dev, tx_buf); + fe_txd_unmap(&dev->dev, &ring->tx_buf[j]); + ring->tx_dma[j].txd2 = TX_DMA_DESP2_DEF; - ptxd->txd2 = TX_DMA_DESP2_DEF; j = NEXT_TX_DESP_IDX(j); } /* make sure that all changes to the dma ring are flushed before we -- 2.25.1