net: hibmcge: Add support for checksum offload

This patch implements the rx checksum offload feature.

The tx checksum offload processing in .ndo_start_xmit()
has been accepted. This patch also adds the tx checksum
feature, including NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM

Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/hisilicon/hibmcge/hbg_main.c

@@ -14,6 +14,9 @@
 #include "hbg_txrx.h"
 #include "hbg_debugfs.h"
 
+#define HBG_SUPPORT_FEATURES (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | \
+			     NETIF_F_RXCSUM)
+
 static void hbg_all_irq_enable(struct hbg_priv *priv, bool enabled)
 {
 	struct hbg_irq_info *info;
@@ -419,6 +422,9 @@ static int hbg_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret)
 		return ret;
 
+	/* set default features */
+	netdev->features |= HBG_SUPPORT_FEATURES;
+	netdev->hw_features |= HBG_SUPPORT_FEATURES;
 	netdev->priv_flags |= IFF_UNICAST_FLT;
 
 	netdev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;

drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c

@@ -202,8 +202,14 @@ static int hbg_napi_tx_recycle(struct napi_struct *napi, int budget)
 }
 
 static bool hbg_rx_check_l3l4_error(struct hbg_priv *priv,
-				    struct hbg_rx_desc *desc)
+				    struct hbg_rx_desc *desc,
+				    struct sk_buff *skb)
 {
+	bool rx_checksum_offload = !!(priv->netdev->features & NETIF_F_RXCSUM);
+
+	skb->ip_summed = rx_checksum_offload ?
+			 CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
+
 	if (likely(!FIELD_GET(HBG_RX_DESC_W4_L3_ERR_CODE_M, desc->word4) &&
 		   !FIELD_GET(HBG_RX_DESC_W4_L4_ERR_CODE_M, desc->word4)))
 		return true;
@@ -215,8 +221,13 @@ static bool hbg_rx_check_l3l4_error(struct hbg_priv *priv,
 		priv->stats.rx_desc_l3_wrong_head_cnt++;
 		return false;
 	case HBG_L3_CSUM_ERR:
+		skb->ip_summed = CHECKSUM_NONE;
 		priv->stats.rx_desc_l3_csum_err_cnt++;
-		return false;
+
+		/* Don't drop packets on csum validation failure,
+		 * suggest by Jakub
+		 */
+		break;
 	case HBG_L3_LEN_ERR:
 		priv->stats.rx_desc_l3_len_err_cnt++;
 		return false;
@@ -238,8 +249,13 @@ static bool hbg_rx_check_l3l4_error(struct hbg_priv *priv,
 		priv->stats.rx_desc_l4_len_err_cnt++;
 		return false;
 	case HBG_L4_CSUM_ERR:
+		skb->ip_summed = CHECKSUM_NONE;
 		priv->stats.rx_desc_l4_csum_err_cnt++;
-		return false;
+
+		/* Don't drop packets on csum validation failure,
+		 * suggest by Jakub
+		 */
+		break;
 	case HBG_L4_ZERO_PORT_NUM:
 		priv->stats.rx_desc_l4_zero_port_num_cnt++;
 		return false;
@@ -322,7 +338,8 @@ static void hbg_update_rx_protocol_stats(struct hbg_priv *priv,
 	hbg_update_rx_ip_protocol_stats(priv, desc);
 }
 
-static bool hbg_rx_pkt_check(struct hbg_priv *priv, struct hbg_rx_desc *desc)
+static bool hbg_rx_pkt_check(struct hbg_priv *priv, struct hbg_rx_desc *desc,
+			     struct sk_buff *skb)
 {
 	if (unlikely(FIELD_GET(HBG_RX_DESC_W2_PKT_LEN_M, desc->word2) >
 		     priv->dev_specs.max_frame_len)) {
@@ -342,7 +359,7 @@ static bool hbg_rx_pkt_check(struct hbg_priv *priv, struct hbg_rx_desc *desc)
 		return false;
 	}
 
-	if (unlikely(!hbg_rx_check_l3l4_error(priv, desc))) {
+	if (unlikely(!hbg_rx_check_l3l4_error(priv, desc, skb))) {
 		priv->stats.rx_desc_l3l4_err_cnt++;
 		return false;
 	}
@@ -413,7 +430,7 @@ static int hbg_napi_rx_poll(struct napi_struct *napi, int budget)
 		rx_desc = (struct hbg_rx_desc *)buffer->skb->data;
 		pkt_len = FIELD_GET(HBG_RX_DESC_W2_PKT_LEN_M, rx_desc->word2);
 
-		if (unlikely(!hbg_rx_pkt_check(priv, rx_desc))) {
+		if (unlikely(!hbg_rx_pkt_check(priv, rx_desc, buffer->skb))) {
 			hbg_buffer_free(buffer);
 			goto next_buffer;
 		}