0001-net-dsa-qca8k-fix-inband-mgmt-for-big-endian-systems.patch

From 4e6bd00b2ffcc00d3654e817235b540871a4ba50 Mon Sep 17 00:00:00 2001
From: Christian Marangi <ansuelsmth@gmail.com>
Date: Sun, 2 Oct 2022 12:19:22 +0200
Subject: [PATCH] net: dsa: qca8k: fix inband mgmt for big-endian systems

The header and the data of the skb for the inband mgmt requires
to be in little-endian. This is problematic for big endian system
as the mgmt header is written in the cpu byte order.

Fix this by converting each value for the mgmt header and data to
little-endian, and convert to cpu byte order the mgmt header and
data sent by the swich.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca/qca8k-8xxx.c | 83 +++++++++++++++++++++-----------
 include/linux/dsa/tag_qca.h      |  8 +--
 2 files changed, 59 insertions(+), 32 deletions(-)

diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c
index 5669c92c93f7..b75c29538d00 100644
--- a/drivers/net/dsa/qca/qca8k-8xxx.c
+++ b/drivers/net/dsa/qca/qca8k-8xxx.c
@@ -137,27 +137,43 @@ static void qca8k_rw_reg_ack_handler(struct dsa_switch *ds, struct sk_buff *skb)
 	struct qca8k_mgmt_eth_data *mgmt_eth_data;
 	struct qca8k_priv *priv = ds->priv;
 	struct qca_mgmt_ethhdr *mgmt_ethhdr;
+	u32 command;
 	u8 len, cmd;
+	int i;
 
 	mgmt_ethhdr = (struct qca_mgmt_ethhdr *)skb_mac_header(skb);
 	mgmt_eth_data = &priv->mgmt_eth_data;
 
-	cmd = FIELD_GET(QCA_HDR_MGMT_CMD, mgmt_ethhdr->command);
-	len = FIELD_GET(QCA_HDR_MGMT_LENGTH, mgmt_ethhdr->command);
+	command = le32_to_cpu(mgmt_ethhdr->command);
+	cmd = FIELD_GET(QCA_HDR_MGMT_CMD, command);
+	len = FIELD_GET(QCA_HDR_MGMT_LENGTH, command);
 
 	/* Make sure the seq match the requested packet */
-	if (mgmt_ethhdr->seq == mgmt_eth_data->seq)
+	if (le32_to_cpu(mgmt_ethhdr->seq) == mgmt_eth_data->seq)
 		mgmt_eth_data->ack = true;
 
 	if (cmd == MDIO_READ) {
-		mgmt_eth_data->data[0] = mgmt_ethhdr->mdio_data;
+		u32 *val = mgmt_eth_data->data;
+
+		*val = le32_to_cpu(mgmt_ethhdr->mdio_data);
 
 		/* Get the rest of the 12 byte of data.
 		 * The read/write function will extract the requested data.
 		 */
-		if (len > QCA_HDR_MGMT_DATA1_LEN)
-			memcpy(mgmt_eth_data->data + 1, skb->data,
-			       QCA_HDR_MGMT_DATA2_LEN);
+		if (len > QCA_HDR_MGMT_DATA1_LEN) {
+			__le32 *data2 = (__le32 *)skb->data;
+
+			val++;
+
+			for (i = sizeof(u32);
+			     i <= QCA_HDR_MGMT_DATA2_LEN &&
+			     i <= (len - QCA_HDR_MGMT_DATA1_LEN);
+			     i += sizeof(u32)) {
+				*val = le32_to_cpu(*data2);
+				val++;
+				data2++;
+			}
+		}
 	}
 
 	complete(&mgmt_eth_data->rw_done);
@@ -169,8 +185,10 @@ static struct sk_buff *qca8k_alloc_mdio_header(enum mdio_cmd cmd, u32 reg, u32 *
 	struct qca_mgmt_ethhdr *mgmt_ethhdr;
 	unsigned int real_len;
 	struct sk_buff *skb;
-	u32 *data2;
+	__le32 *data2;
+	u32 command;
 	u16 hdr;
+	int i;
 
 	skb = dev_alloc_skb(QCA_HDR_MGMT_PKT_LEN);
 	if (!skb)
@@ -199,20 +217,31 @@ static struct sk_buff *qca8k_alloc_mdio_header(enum mdio_cmd cmd, u32 reg, u32 *
 	hdr |= FIELD_PREP(QCA_HDR_XMIT_DP_BIT, BIT(0));
 	hdr |= FIELD_PREP(QCA_HDR_XMIT_CONTROL, QCA_HDR_XMIT_TYPE_RW_REG);
 
-	mgmt_ethhdr->command = FIELD_PREP(QCA_HDR_MGMT_ADDR, reg);
-	mgmt_ethhdr->command |= FIELD_PREP(QCA_HDR_MGMT_LENGTH, real_len);
-	mgmt_ethhdr->command |= FIELD_PREP(QCA_HDR_MGMT_CMD, cmd);
-	mgmt_ethhdr->command |= FIELD_PREP(QCA_HDR_MGMT_CHECK_CODE,
+	command = FIELD_PREP(QCA_HDR_MGMT_ADDR, reg);
+	command |= FIELD_PREP(QCA_HDR_MGMT_LENGTH, real_len);
+	command |= FIELD_PREP(QCA_HDR_MGMT_CMD, cmd);
+	command |= FIELD_PREP(QCA_HDR_MGMT_CHECK_CODE,
 					   QCA_HDR_MGMT_CHECK_CODE_VAL);
 
+	mgmt_ethhdr->command = cpu_to_le32(command);
+
 	if (cmd == MDIO_WRITE)
-		mgmt_ethhdr->mdio_data = *val;
+		mgmt_ethhdr->mdio_data = cpu_to_le32(*val);
 
 	mgmt_ethhdr->hdr = htons(hdr);
 
 	data2 = skb_put_zero(skb, QCA_HDR_MGMT_DATA2_LEN + QCA_HDR_MGMT_PADDING_LEN);
-	if (cmd == MDIO_WRITE && len > QCA_HDR_MGMT_DATA1_LEN)
-		memcpy(data2, val + 1, len - QCA_HDR_MGMT_DATA1_LEN);
+	if (cmd == MDIO_WRITE && len > QCA_HDR_MGMT_DATA1_LEN) {
+		val++;
+		for (i = sizeof(u32);
+		     i <= QCA_HDR_MGMT_DATA2_LEN &&
+		     i <= (len - QCA_HDR_MGMT_DATA1_LEN);
+		     i += sizeof(u32)) {
+			*data2 = cpu_to_le32(*val);
+			data2++;
+			val++;
+		}
+	}
 
 	return skb;
 }
@@ -220,9 +249,11 @@ static struct sk_buff *qca8k_alloc_mdio_header(enum mdio_cmd cmd, u32 reg, u32 *
 static void qca8k_mdio_header_fill_seq_num(struct sk_buff *skb, u32 seq_num)
 {
 	struct qca_mgmt_ethhdr *mgmt_ethhdr;
+	u32 seq;
 
+	seq = FIELD_PREP(QCA_HDR_MGMT_SEQ_NUM, seq_num);
 	mgmt_ethhdr = (struct qca_mgmt_ethhdr *)skb->data;
-	mgmt_ethhdr->seq = FIELD_PREP(QCA_HDR_MGMT_SEQ_NUM, seq_num);
+	mgmt_ethhdr->seq = cpu_to_le32(seq);
 }
 
 static int qca8k_read_eth(struct qca8k_priv *priv, u32 reg, u32 *val, int len)
@@ -1487,9 +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;
@@ -1501,28 +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 50be7cbd93a5..b1b5720d89a5 100644
--- a/include/linux/dsa/tag_qca.h
+++ b/include/linux/dsa/tag_qca.h
@@ -61,9 +61,9 @@ struct sk_buff;
 
 /* Special struct emulating a Ethernet header */
 struct qca_mgmt_ethhdr {
-	u32 command;		/* command bit 31:0 */
-	u32 seq;		/* seq 63:32 */
-	u32 mdio_data;		/* first 4byte mdio */
+	__le32 command;		/* command bit 31:0 */
+	__le32 seq;		/* seq 63:32 */
+	__le32 mdio_data;		/* first 4byte mdio */
 	__be16 hdr;		/* qca hdr */
 } __packed;
 
@@ -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