net: dsa: qca8k: fix ethtool autocast mib for big-endian systems

The switch sends autocast mib in little-endian. This is problematic for
big-endian system as the values needs to be converted.

Fix this by converting each mib value to cpu byte order.

Fixes: 5c957c7 ("net: dsa: qca8k: add support for mib autocast in Ethernet packet")
Tested-by: Pawel Dembicki <[email protected]>
Tested-by: Lech Perczak <[email protected]>
Signed-off-by: Christian Marangi <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Ansuel

drivers/net/dsa/qca/qca8k-8xxx.c

@@ -1518,9 +1518,9 @@ static void qca8k_mib_autocast_handler(struct dsa_switch *ds, struct sk_buff *sk
 	struct qca8k_priv *priv = ds->priv;
 	const struct qca8k_mib_desc *mib;
 	struct mib_ethhdr *mib_ethhdr;
-	int i, mib_len, offset = 0;
-	u64 *data;
+	__le32 *data2;
 	u8 port;
+	int i;
 
 	mib_ethhdr = (struct mib_ethhdr *)skb_mac_header(skb);
 	mib_eth_data = &priv->mib_eth_data;
@@ -1532,28 +1532,24 @@ static void qca8k_mib_autocast_handler(struct dsa_switch *ds, struct sk_buff *sk
 	if (port != mib_eth_data->req_port)
 		goto exit;
 
-	data = mib_eth_data->data;
+	data2 = (__le32 *)skb->data;
 
 	for (i = 0; i < priv->info->mib_count; i++) {
 		mib = &ar8327_mib[i];
 
 		/* First 3 mib are present in the skb head */
 		if (i < 3) {
-			data[i] = mib_ethhdr->data[i];
+			mib_eth_data->data[i] = get_unaligned_le32(mib_ethhdr->data + i);
 			continue;
 		}
 
-		mib_len = sizeof(uint32_t);
-
 		/* Some mib are 64 bit wide */
 		if (mib->size == 2)
-			mib_len = sizeof(uint64_t);
-
-		/* Copy the mib value from packet to the */
-		memcpy(data + i, skb->data + offset, mib_len);
+			mib_eth_data->data[i] = get_unaligned_le64((__le64 *)data2);
+		else
+			mib_eth_data->data[i] = get_unaligned_le32(data2);
 
-		/* Set the offset for the next mib */
-		offset += mib_len;
+		data2 += mib->size;
 	}
 
 exit:

include/linux/dsa/tag_qca.h

@@ -73,7 +73,7 @@ enum mdio_cmd {
 };
 
 struct mib_ethhdr {
-	u32 data[3];		/* first 3 mib counter */
+	__le32 data[3];		/* first 3 mib counter */
 	__be16 hdr;		/* qca hdr */
 } __packed;