net: hns3: refactor hns3_nic_reuse_page()

mainline inclusion
from mainline-master
commit e74a726d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4M1HB
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e74a726da2c4

----------------------------------------------------------------------

Split rx copybreak handle into a separate function from function
hns3_nic_reuse_page() to improve code simplicity.
Signed-off-by: NHao Chen <chenhao288@hisilicon.com>
Signed-off-by: NGuangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NYongxin Li <liyongxin1@huawei.com>
Signed-off-by: NJunxin Chen <chenjunxin1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

@@ -3545,6 +3545,38 @@ static bool hns3_can_reuse_page(struct hns3_desc_cb *cb)
 	return page_count(cb->priv) == cb->pagecnt_bias;
 }
 
+static int hns3_handle_rx_copybreak(struct sk_buff *skb, int i,
+				    struct hns3_enet_ring *ring,
+				    int pull_len,
+				    struct hns3_desc_cb *desc_cb)
+{
+	struct hns3_desc *desc = &ring->desc[ring->next_to_clean];
+	u32 frag_offset = desc_cb->page_offset + pull_len;
+	int size = le16_to_cpu(desc->rx.size);
+	u32 frag_size = size - pull_len;
+	void *frag = napi_alloc_frag(frag_size);
+
+	if (unlikely(!frag)) {
+		u64_stats_update_begin(&ring->syncp);
+		ring->stats.frag_alloc_err++;
+		u64_stats_update_end(&ring->syncp);
+
+		hns3_rl_err(ring_to_netdev(ring),
+			    "failed to allocate rx frag\n");
+		return -ENOMEM;
+	}
+
+	desc_cb->reuse_flag = 1;
+	memcpy(frag, desc_cb->buf + frag_offset, frag_size);
+	skb_add_rx_frag(skb, i, virt_to_page(frag),
+			offset_in_page(frag), frag_size, frag_size);
+
+	u64_stats_update_begin(&ring->syncp);
+	ring->stats.frag_alloc++;
+	u64_stats_update_end(&ring->syncp);
+	return 0;
+}
+
 static void hns3_nic_reuse_page(struct sk_buff *skb, int i,
 				struct hns3_enet_ring *ring, int pull_len,
 				struct hns3_desc_cb *desc_cb)
@@ -3554,6 +3586,7 @@ static void hns3_nic_reuse_page(struct sk_buff *skb, int i,
 	int size = le16_to_cpu(desc->rx.size);
 	u32 truesize = hns3_buf_size(ring);
 	u32 frag_size = size - pull_len;
+	int ret = 0;
 	bool reused;
 
 	if (ring->page_pool) {
@@ -3588,29 +3621,11 @@ static void hns3_nic_reuse_page(struct sk_buff *skb, int i,
 		desc_cb->page_offset = 0;
 		desc_cb->reuse_flag = 1;
 	} else if (frag_size <= ring->rx_copybreak) {
-		void *frag = napi_alloc_frag(frag_size);
-
-		if (unlikely(!frag)) {
-			u64_stats_update_begin(&ring->syncp);
-			ring->stats.frag_alloc_err++;
-			u64_stats_update_end(&ring->syncp);
-
-			hns3_rl_err(ring_to_netdev(ring),
-				    "failed to allocate rx frag\n");
+		ret = hns3_handle_rx_copybreak(skb, i, ring, pull_len, desc_cb);
+		if (ret)
 			goto out;
 	}
 
-		desc_cb->reuse_flag = 1;
-		memcpy(frag, desc_cb->buf + frag_offset, frag_size);
-		skb_add_rx_frag(skb, i, virt_to_page(frag),
-				offset_in_page(frag), frag_size, frag_size);
-
-		u64_stats_update_begin(&ring->syncp);
-		ring->stats.frag_alloc++;
-		u64_stats_update_end(&ring->syncp);
-		return;
-	}
-
 out:
 	desc_cb->pagecnt_bias--;