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

From 691af799ae6652911df0e2a2989b351c57b30632 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 to little-endian,
and convert to cpu byte order the mgmt header sent by the swich.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca/qca8k-8xxx.c | 89 ++++++++++++++++++++++----------
 include/linux/dsa/tag_qca.h      |  6 +--
 2 files changed, 65 insertions(+), 30 deletions(-)

diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c
index 5669c92c93f7..46ad13541dc3 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 *data, *data2;
+	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;
+		data = mgmt_eth_data->data;
+
+		*data = 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) {
+			data2 = (u32 *) skb->data;
+			data++;
+
+			for (i = sizeof(u32);
+			     i < QCA_HDR_MGMT_DATA2_LEN &&
+			     i < (len - QCA_HDR_MGMT_DATA1_LEN);
+			     i += sizeof(u32)) {
+				*data = le32_to_cpu(*data2);
+				data++;
+				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 command;
 	u32 *data2;
 	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 +1518,10 @@ 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;
+	u32 *data2;
 	u64 *data;
 	u8 port;
+	int i;
 
 	mib_ethhdr = (struct mib_ethhdr *)skb_mac_header(skb);
 	mib_eth_data = &priv->mib_eth_data;
@@ -1502,27 +1534,30 @@ static void qca8k_mib_autocast_handler(struct dsa_switch *ds, struct sk_buff *sk
 		goto exit;
 
 	data = mib_eth_data->data;
+	data2 = (u32 *) 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];
-			continue;
+			*data = le32_to_cpu(mib_ethhdr->data[i]);
+			goto increase;
 		}
 
-		mib_len = sizeof(uint32_t);
+		/* Copy the mib value from packet to the mib */
+		*data = le32_to_cpu(*data2);
+		data2++;
 
 		/* 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);
-
-		/* Set the offset for the next mib */
-		offset += mib_len;
+		if (mib->size == 2) {
+			/* Write the second part of the 64 bit mib */
+			*((u32 *) data + 1) = le32_to_cpu(*data2);
+			data2++;
+		}
+increase:
+		/* Move the ptr to the next mib */
+		data++;
 	}
 
 exit:
diff --git a/include/linux/dsa/tag_qca.h b/include/linux/dsa/tag_qca.h
index 50be7cbd93a5..0e176da1e43f 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;
 
-- 
2.37.2