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From:   Christian Marangi <ansuelsmth@gmail.com>
To:     Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Christian Marangi <ansuelsmth@gmail.com>,
        "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Pawel Dembicki <paweldembicki@gmail.com>,
        Lech Perczak <lech.perczak@gmail.com>
Subject: [net PATCH 2/2] net: dsa: qca8k: fix ethtool autocast mib for big-endian systems
Date:   Mon, 10 Oct 2022 13:14:59 +0200
Message-Id: <20221010111459.18958-2-ansuelsmth@gmail.com>
In-Reply-To: <20221010111459.18958-1-ansuelsmth@gmail.com>
References: <20221010111459.18958-1-ansuelsmth@gmail.com>
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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: 5c957c7ca78c ("net: dsa: qca8k: add support for mib autocast in Ethernet packet")
Tested-by: Pawel Dembicki <paweldembicki@gmail.com>
Tested-by: Lech Perczak <lech.perczak@gmail.com>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca/qca8k-8xxx.c | 20 ++++++++------------
 include/linux/dsa/tag_qca.h      |  2 +-
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c
index 4bb9b7eac68b..e3e89ce479c6 100644
--- a/drivers/net/dsa/qca/qca8k-8xxx.c
+++ b/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] = le32_to_cpu(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] = le64_to_cpu(*(__le64 *)data2);
+		else
+			mib_eth_data->data[i] = le32_to_cpu(*data2);
 
-		/* Set the offset for the next mib */
-		offset += mib_len;
+		data2 += mib->size;
 	}
 
 exit:
diff --git a/include/linux/dsa/tag_qca.h b/include/linux/dsa/tag_qca.h
index 0e176da1e43f..b1b5720d89a5 100644
--- a/include/linux/dsa/tag_qca.h
+++ b/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;
 
-- 
2.37.2