net/hns3: fix FEC mode check

[ upstream commit 0cf0f931267ae751c503dba929307bb2a6acbbfa ]

The function is_fec_mode_one_bit_set() is used to check whether
the binary of the mode from user only contains one '1'. But it
uses the bytes number this mode variable occupied to calculate
the count. So this patch uses __builtin_popcount() to replace it.

This patch also extracts the code for verifying mode parameter into
a function.

Fixes: 9bf2ea8 ("net/hns3: support FEC")

Signed-off-by: Jie Hai <haijie1@huawei.com>
Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>

drivers/net/hns3/hns3_ethdev.c

@@ -6197,53 +6197,50 @@ get_current_speed_fec_cap(struct hns3_hw *hw, struct rte_eth_fec_capa *fec_capa)
 	return cur_capa;
 }
 
-static bool
-is_fec_mode_one_bit_set(uint32_t mode)
-{
-	int cnt = 0;
-	uint8_t i;
-
-	for (i = 0; i < sizeof(mode); i++)
-		if (mode >> i & 0x1)
-			cnt++;
-
-	return cnt == 1 ? true : false;
-}
-
 static int
-hns3_fec_set(struct rte_eth_dev *dev, uint32_t mode)
+hns3_fec_mode_valid(struct rte_eth_dev *dev, uint32_t mode)
 {
 #define FEC_CAPA_NUM 2
 	struct hns3_adapter *hns = dev->data->dev_private;
 	struct hns3_hw *hw = HNS3_DEV_PRIVATE_TO_HW(hns);
-	struct hns3_pf *pf = &hns->pf;
-
 	struct rte_eth_fec_capa fec_capa[FEC_CAPA_NUM];
-	uint32_t cur_capa;
 	uint32_t num = FEC_CAPA_NUM;
+	uint32_t cur_capa;
 	int ret;
 
-	ret = hns3_fec_get_capability(dev, fec_capa, num);
-	if (ret < 0)
-		return ret;
-
-	/* HNS3 PMD only support one bit set mode, e.g. 0x1, 0x4 */
-	if (!is_fec_mode_one_bit_set(mode)) {
-		hns3_err(hw, "FEC mode(0x%x) not supported in HNS3 PMD, "
-			     "FEC mode should be only one bit set", mode);
+	if (__builtin_popcount(mode) != 1) {
+		hns3_err(hw, "FEC mode(0x%x) should be only one bit set", mode);
 		return -EINVAL;
 	}
 
+	ret = hns3_fec_get_capability(dev, fec_capa, num);
+	if (ret < 0)
+		return ret;
 	/*
 	 * Check whether the configured mode is within the FEC capability.
 	 * If not, the configured mode will not be supported.
 	 */
 	cur_capa = get_current_speed_fec_cap(hw, fec_capa);
-	if (!(cur_capa & mode)) {
-		hns3_err(hw, "unsupported FEC mode = 0x%x", mode);
+	if ((cur_capa & mode) == 0) {
+		hns3_err(hw, "unsupported FEC mode(0x%x)", mode);
 		return -EINVAL;
 	}
 
+	return 0;
+}
+
+static int
+hns3_fec_set(struct rte_eth_dev *dev, uint32_t mode)
+{
+	struct hns3_adapter *hns = dev->data->dev_private;
+	struct hns3_hw *hw = HNS3_DEV_PRIVATE_TO_HW(hns);
+	struct hns3_pf *pf = &hns->pf;
+	int ret;
+
+	ret = hns3_fec_mode_valid(dev, mode);
+	if (ret != 0)
+		return ret;
+
 	rte_spinlock_lock(&hw->lock);
 	ret = hns3_set_fec_hw(hw, mode);
 	if (ret) {