From: Peng Li <lipeng321@huawei.com>
Date: Tue, 16 Oct 2018 19:58:49 +0800
Subject: net: hns3: move DMA map into hns3_fill_desc
Patch-mainline: v4.20-rc1
Git-commit: 5188f218fc860da15755bfa5cc357baf2114d586
References: bsc#1104353 FATE#326415

To solve the L3 checksum error problem which happens when driver
does not clear L3 checksum, DMA map should be done after calling
skb_cow_head.

This patch moves DMA map into hns3_fill_desc to ensure that DMA
map is done after calling skb_cow_head.

Fixes: 76ad4f0ee747 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.c |   47 +++++++++++-------------
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.h |    3 -
 2 files changed, 24 insertions(+), 26 deletions(-)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -977,18 +977,20 @@ static int hns3_fill_desc_vtags(struct s
 }
 
 static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv,
-			  int size, dma_addr_t dma, int frag_end,
-			  enum hns_desc_type type)
+			  int size, int frag_end, enum hns_desc_type type)
 {
 	struct hns3_desc_cb *desc_cb = &ring->desc_cb[ring->next_to_use];
 	struct hns3_desc *desc = &ring->desc[ring->next_to_use];
+	struct device *dev = ring_to_dev(ring);
 	u32 ol_type_vlan_len_msec = 0;
 	u16 bdtp_fe_sc_vld_ra_ri = 0;
+	struct skb_frag_struct *frag;
 	u32 type_cs_vlan_tso = 0;
 	struct sk_buff *skb;
 	u16 inner_vtag = 0;
 	u16 out_vtag = 0;
 	u32 paylen = 0;
+	dma_addr_t dma;
 	u16 mss = 0;
 	u8 ol4_proto;
 	u8 il4_proto;
@@ -997,11 +999,9 @@ static int hns3_fill_desc(struct hns3_en
 	/* The txbd's baseinfo of DESC_TYPE_PAGE & DESC_TYPE_SKB */
 	desc_cb->priv = priv;
 	desc_cb->length = size;
-	desc_cb->dma = dma;
 	desc_cb->type = type;
 
 	/* now, fill the descriptor */
-	desc->addr = cpu_to_le64(dma);
 	desc->tx.send_size = cpu_to_le16((u16)size);
 	hns3_set_txbd_baseinfo(&bdtp_fe_sc_vld_ra_ri, frag_end);
 	desc->tx.bdtp_fe_sc_vld_ra_ri = cpu_to_le16(bdtp_fe_sc_vld_ra_ri);
@@ -1046,8 +1046,21 @@ static int hns3_fill_desc(struct hns3_en
 		desc->tx.mss = cpu_to_le16(mss);
 		desc->tx.vlan_tag = cpu_to_le16(inner_vtag);
 		desc->tx.outer_vlan_tag = cpu_to_le16(out_vtag);
+
+		dma = dma_map_single(dev, skb->data, size, DMA_TO_DEVICE);
+	} else {
+		frag = (struct skb_frag_struct *)priv;
+		dma = skb_frag_dma_map(dev, frag, 0, size, DMA_TO_DEVICE);
 	}
 
+	if (dma_mapping_error(ring->dev, dma)) {
+		ring->stats.sw_err_cnt++;
+		return -ENOMEM;
+	}
+
+	desc_cb->dma = dma;
+	desc->addr = cpu_to_le64(dma);
+
 	/* move ring pointer to next.*/
 	ring_ptr_move_fw(ring, next_to_use);
 
@@ -1137,12 +1150,10 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_
 	struct hns3_nic_ring_data *ring_data =
 		&tx_ring_data(priv, skb->queue_mapping);
 	struct hns3_enet_ring *ring = ring_data->ring;
-	struct device *dev = priv->dev;
 	struct netdev_queue *dev_queue;
 	struct skb_frag_struct *frag;
 	int next_to_use_head;
 	int next_to_use_frag;
-	dma_addr_t dma;
 	int buf_num;
 	int seg_num;
 	int size;
@@ -1177,15 +1188,8 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_
 
 	next_to_use_head = ring->next_to_use;
 
-	dma = dma_map_single(dev, skb->data, size, DMA_TO_DEVICE);
-	if (dma_mapping_error(dev, dma)) {
-		netdev_err(netdev, "TX head DMA map failed\n");
-		ring->stats.sw_err_cnt++;
-		goto out_err_tx_ok;
-	}
-
-	ret = priv->ops.fill_desc(ring, skb, size, dma, seg_num == 1 ? 1 : 0,
-			   DESC_TYPE_SKB);
+	ret = priv->ops.fill_desc(ring, skb, size, seg_num == 1 ? 1 : 0,
+				  DESC_TYPE_SKB);
 	if (ret)
 		goto head_dma_map_err;
 
@@ -1194,15 +1198,10 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_
 	for (i = 1; i < seg_num; i++) {
 		frag = &skb_shinfo(skb)->frags[i - 1];
 		size = skb_frag_size(frag);
-		dma = skb_frag_dma_map(dev, frag, 0, size, DMA_TO_DEVICE);
-		if (dma_mapping_error(dev, dma)) {
-			netdev_err(netdev, "TX frag(%d) DMA map failed\n", i);
-			ring->stats.sw_err_cnt++;
-			goto frag_dma_map_err;
-		}
-		ret = priv->ops.fill_desc(ring, skb_frag_page(frag), size, dma,
-				    seg_num - 1 == i ? 1 : 0,
-				    DESC_TYPE_PAGE);
+
+		ret = priv->ops.fill_desc(ring, frag, size,
+					  seg_num - 1 == i ? 1 : 0,
+					  DESC_TYPE_PAGE);
 
 		if (ret)
 			goto frag_dma_map_err;
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
@@ -419,8 +419,7 @@ struct hns3_nic_ring_data {
 
 struct hns3_nic_ops {
 	int (*fill_desc)(struct hns3_enet_ring *ring, void *priv,
-			 int size, dma_addr_t dma, int frag_end,
-			 enum hns_desc_type type);
+			 int size, int frag_end, enum hns_desc_type type);
 	int (*maybe_stop_tx)(struct sk_buff **out_skb,
 			     int *bnum, struct hns3_enet_ring *ring);
 	void (*get_rxd_bnum)(u32 bnum_flag, int *out_bnum);