can: xilinx_can: Add ethtool stats interface for ECC errors

Add ethtool stats interface for reading FIFO 1bit/2bit ECC errors
information.
Signed-off-by: Srinivas Goud <srinivas.goud@amd.com>
Link: https://lore.kernel.org/all/20240213-xilinx_ecc-v8-3-8d75f8b80771@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/xilinx_can.c

@@ -228,6 +228,7 @@ struct xcan_devtype_data {
  * @transceiver:		Optional pointer to associated CAN transceiver
  * @rstc:			Pointer to reset control
  * @ecc_enable:			ECC enable flag
+ * @syncp:			synchronization for ECC error stats
  * @ecc_rx_2_bit_errors:	RXFIFO 2bit ECC count
  * @ecc_rx_1_bit_errors:	RXFIFO 1bit ECC count
  * @ecc_txol_2_bit_errors:	TXOLFIFO 2bit ECC count
@@ -254,6 +255,7 @@ struct xcan_priv {
 	struct phy *transceiver;
 	struct reset_control *rstc;
 	bool ecc_enable;
+	struct u64_stats_sync syncp;
 	u64_stats_t ecc_rx_2_bit_errors;
 	u64_stats_t ecc_rx_1_bit_errors;
 	u64_stats_t ecc_txol_2_bit_errors;
@@ -347,6 +349,24 @@ static const struct can_tdc_const xcan_tdc_const_canfd2 = {
 	.tdcf_max = 0,
 };
 
+enum xcan_stats_type {
+	XCAN_ECC_RX_2_BIT_ERRORS,
+	XCAN_ECC_RX_1_BIT_ERRORS,
+	XCAN_ECC_TXOL_2_BIT_ERRORS,
+	XCAN_ECC_TXOL_1_BIT_ERRORS,
+	XCAN_ECC_TXTL_2_BIT_ERRORS,
+	XCAN_ECC_TXTL_1_BIT_ERRORS,
+};
+
+static const char xcan_priv_flags_strings[][ETH_GSTRING_LEN] = {
+	[XCAN_ECC_RX_2_BIT_ERRORS] = "ecc_rx_2_bit_errors",
+	[XCAN_ECC_RX_1_BIT_ERRORS] = "ecc_rx_1_bit_errors",
+	[XCAN_ECC_TXOL_2_BIT_ERRORS] = "ecc_txol_2_bit_errors",
+	[XCAN_ECC_TXOL_1_BIT_ERRORS] = "ecc_txol_1_bit_errors",
+	[XCAN_ECC_TXTL_2_BIT_ERRORS] = "ecc_txtl_2_bit_errors",
+	[XCAN_ECC_TXTL_1_BIT_ERRORS] = "ecc_txtl_1_bit_errors",
+};
+
 /**
  * xcan_write_reg_le - Write a value to the device register little endian
  * @priv:	Driver private data structure
@@ -1182,6 +1202,8 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
 		priv->write_reg(priv, XCAN_ECC_CFG_OFFSET, XCAN_ECC_CFG_REECRX_MASK |
 				XCAN_ECC_CFG_REECTXOL_MASK | XCAN_ECC_CFG_REECTXTL_MASK);
 
+		u64_stats_update_begin(&priv->syncp);
+
 		if (isr & XCAN_IXR_E2BERX_MASK) {
 			u64_stats_add(&priv->ecc_rx_2_bit_errors,
 				      FIELD_GET(XCAN_ECC_2BIT_CNT_MASK, reg_rx_ecc));
@@ -1211,6 +1233,8 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
 			u64_stats_add(&priv->ecc_txtl_1_bit_errors,
 				      FIELD_GET(XCAN_ECC_1BIT_CNT_MASK, reg_txtl_ecc));
 		}
+
+		u64_stats_update_end(&priv->syncp);
 	}
 
 	if (cf.can_id) {
@@ -1637,6 +1661,43 @@ static int xcan_get_auto_tdcv(const struct net_device *ndev, u32 *tdcv)
 	return 0;
 }
 
+static void xcan_get_strings(struct net_device *ndev, u32 stringset, u8 *buf)
+{
+	switch (stringset) {
+	case ETH_SS_STATS:
+		memcpy(buf, &xcan_priv_flags_strings,
+		       sizeof(xcan_priv_flags_strings));
+	}
+}
+
+static int xcan_get_sset_count(struct net_device *netdev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(xcan_priv_flags_strings);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static void xcan_get_ethtool_stats(struct net_device *ndev,
+				   struct ethtool_stats *stats, u64 *data)
+{
+	struct xcan_priv *priv = netdev_priv(ndev);
+	unsigned int start;
+
+	do {
+		start = u64_stats_fetch_begin(&priv->syncp);
+
+		data[XCAN_ECC_RX_2_BIT_ERRORS] = u64_stats_read(&priv->ecc_rx_2_bit_errors);
+		data[XCAN_ECC_RX_1_BIT_ERRORS] = u64_stats_read(&priv->ecc_rx_1_bit_errors);
+		data[XCAN_ECC_TXOL_2_BIT_ERRORS] = u64_stats_read(&priv->ecc_txol_2_bit_errors);
+		data[XCAN_ECC_TXOL_1_BIT_ERRORS] = u64_stats_read(&priv->ecc_txol_1_bit_errors);
+		data[XCAN_ECC_TXTL_2_BIT_ERRORS] = u64_stats_read(&priv->ecc_txtl_2_bit_errors);
+		data[XCAN_ECC_TXTL_1_BIT_ERRORS] = u64_stats_read(&priv->ecc_txtl_1_bit_errors);
+	} while (u64_stats_fetch_retry(&priv->syncp, start));
+}
+
 static const struct net_device_ops xcan_netdev_ops = {
 	.ndo_open	= xcan_open,
 	.ndo_stop	= xcan_close,
@@ -1646,6 +1707,9 @@ static const struct net_device_ops xcan_netdev_ops = {
 
 static const struct ethtool_ops xcan_ethtool_ops = {
 	.get_ts_info = ethtool_op_get_ts_info,
+	.get_strings = xcan_get_strings,
+	.get_sset_count = xcan_get_sset_count,
+	.get_ethtool_stats = xcan_get_ethtool_stats,
 };
 
 /**