[PATCH net-next 1/4] net: dsa: motorcomm: Split MIB module

@@ -2,4 +2,5 @@
 obj-$(CONFIG_NET_DSA_YT921X) += yt921x.o
 yt921x-objs := chip.o
 yt921x-$(CONFIG_NET_DSA_YT921X_LEDS) += leds.o
+yt921x-objs += mib.o
 yt921x-objs += smi.o

@@ -27,75 +27,9 @@
 
 #include "chip.h"
 #include "leds.h"
+#include "mib.h"
 #include "smi.h"
 
-struct yt921x_mib_desc {
-	unsigned int size;
-	unsigned int offset;
-	const char *name;
-};
-
-#define MIB_DESC(_size, _offset, _name) \
-	{_size, _offset, _name}
-
-/* Must agree with yt921x_mib
- *
- * Unstructured fields (name != NULL) will appear in get_ethtool_stats(),
- * structured go to their *_stats() methods, but we need their sizes and offsets
- * to perform 32bit MIB overflow wraparound.
- */
-static const struct yt921x_mib_desc yt921x_mib_descs[] = {
-	MIB_DESC(1, YT921X_MIB_DATA_RX_BROADCAST, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PAUSE, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_MULTICAST, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_CRC_ERR, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_RX_ALIGN_ERR, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_UNDERSIZE_ERR, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_FRAG_ERR, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_64, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_65_TO_127, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_128_TO_255, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_256_TO_511, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_512_TO_1023, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_1024_TO_1518, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_1519_TO_MAX, NULL),
-	MIB_DESC(2, YT921X_MIB_DATA_RX_GOOD_BYTES, NULL),
-
-	MIB_DESC(2, YT921X_MIB_DATA_RX_BAD_BYTES, "RxBadBytes"),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_OVERSIZE_ERR, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_RX_DROPPED, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_BROADCAST, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PAUSE, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_MULTICAST, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_TX_UNDERSIZE_ERR, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_64, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_65_TO_127, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_128_TO_255, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_256_TO_511, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_512_TO_1023, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_1024_TO_1518, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_1519_TO_MAX, NULL),
-
-	MIB_DESC(2, YT921X_MIB_DATA_TX_GOOD_BYTES, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_COLLISION, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_TX_EXCESSIVE_COLLISION, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_MULTIPLE_COLLISION, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_SINGLE_COLLISION, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT, NULL),
-
-	MIB_DESC(1, YT921X_MIB_DATA_TX_DEFERRED, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_LATE_COLLISION, NULL),
-	MIB_DESC(1, YT921X_MIB_DATA_RX_OAM, "RxOAM"),
-	MIB_DESC(1, YT921X_MIB_DATA_TX_OAM, "TxOAM"),
-};
-
 struct yt921x_info {
 	const char *name;
 	u16 major;

@@ -154,14 +88,6 @@ static const struct yt921x_info yt921x_infos[] = {
 
 #define YT921X_VID_UNWARE	4095
 
-/* The interval should be small enough to avoid overflow of 32bit MIBs.
- *
- * Until we can read MIBs from stats64 call directly (i.e. sleep
- * there), we have to poll stats more frequently then it is actually needed.
- * For overflow protection, normally, 100 sec interval should have been OK.
- */
-#define YT921X_STATS_INTERVAL_JIFFIES	(3 * HZ)
-
 struct yt921x_reg_mdio {
 	struct mii_bus *bus;
 	int addr;

@@ -544,294 +470,6 @@ yt921x_mbus_ext_init(struct yt921x_priv *priv, struct device_node *mnp)
 	return 0;
 }
 
-/* Read and handle overflow of 32bit MIBs. MIB buffer must be zeroed before. */
-static int yt921x_read_mib(struct yt921x_priv *priv, int port)
-{
-	struct yt921x_port *pp = &priv->ports[port];
-	struct device *dev = to_device(priv);
-	struct yt921x_mib *mib = &pp->mib;
-	int res = 0;
-
-	/* Reading of yt921x_port::mib is not protected by a lock and it's vain
-	 * to keep its consistency, since we have to read registers one by one
-	 * and there is no way to make a snapshot of MIB stats.
-	 *
-	 * Writing (by this function only) is and should be protected by
-	 * reg_lock.
-	 */
-
-	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
-		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
-		u32 reg = YT921X_MIBn_DATA0(port) + desc->offset;
-		u64 *valp = &((u64 *)mib)[i];
-		u32 val0;
-		u64 val;
-
-		res = yt921x_reg_read(priv, reg, &val0);
-		if (res)
-			break;
-
-		if (desc->size <= 1) {
-			u64 old_val = *valp;
-
-			val = (old_val & ~(u64)U32_MAX) | val0;
-			if (val < old_val)
-				val += 1ull << 32;
-		} else {
-			u32 val1;
-
-			res = yt921x_reg_read(priv, reg + 4, &val1);
-			if (res)
-				break;
-			val = ((u64)val1 << 32) | val0;
-		}
-
-		WRITE_ONCE(*valp, val);
-	}
-
-	pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte +
-			mib->rx_128_255byte + mib->rx_256_511byte +
-			mib->rx_512_1023byte + mib->rx_1024_1518byte +
-			mib->rx_jumbo;
-	pp->tx_frames = mib->tx_64byte + mib->tx_65_127byte +
-			mib->tx_128_255byte + mib->tx_256_511byte +
-			mib->tx_512_1023byte + mib->tx_1024_1518byte +
-			mib->tx_jumbo;
-
-	if (res)
-		dev_err(dev, "Failed to %s port %d: %i\n", "read stats for",
-			port, res);
-	return res;
-}
-
-static void yt921x_poll_mib(struct work_struct *work)
-{
-	struct yt921x_port *pp = container_of_const(work, struct yt921x_port,
-						    mib_read.work);
-	struct yt921x_priv *priv = (void *)(pp - pp->index) -
-				   offsetof(struct yt921x_priv, ports);
-	unsigned long delay = YT921X_STATS_INTERVAL_JIFFIES;
-	int port = pp->index;
-	int res;
-
-	mutex_lock(&priv->reg_lock);
-	res = yt921x_read_mib(priv, port);
-	mutex_unlock(&priv->reg_lock);
-	if (res)
-		delay *= 4;
-
-	schedule_delayed_work(&pp->mib_read, delay);
-}
-
-static void
-yt921x_dsa_get_strings(struct dsa_switch *ds, int port, u32 stringset,
-		       uint8_t *data)
-{
-	if (stringset != ETH_SS_STATS)
-		return;
-
-	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
-		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
-
-		if (desc->name)
-			ethtool_puts(&data, desc->name);
-	}
-}
-
-static void
-yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
-{
-	struct yt921x_priv *priv = to_yt921x_priv(ds);
-	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
-	size_t j;
-
-	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
-	mutex_unlock(&priv->reg_lock);
-
-	j = 0;
-	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
-		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
-
-		if (!desc->name)
-			continue;
-
-		data[j] = ((u64 *)mib)[i];
-		j++;
-	}
-}
-
-static int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset)
-{
-	int cnt = 0;
-
-	if (sset != ETH_SS_STATS)
-		return 0;
-
-	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
-		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
-
-		if (desc->name)
-			cnt++;
-	}
-
-	return cnt;
-}
-
-static void
-yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
-			     struct ethtool_eth_mac_stats *mac_stats)
-{
-	struct yt921x_priv *priv = to_yt921x_priv(ds);
-	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
-
-	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
-	mutex_unlock(&priv->reg_lock);
-
-	mac_stats->FramesTransmittedOK = pp->tx_frames;
-	mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
-	mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
-	mac_stats->FramesReceivedOK = pp->rx_frames;
-	mac_stats->FrameCheckSequenceErrors = mib->rx_crc_errors;
-	mac_stats->AlignmentErrors = mib->rx_alignment_errors;
-	mac_stats->OctetsTransmittedOK = mib->tx_good_bytes;
-	mac_stats->FramesWithDeferredXmissions = mib->tx_deferred;
-	mac_stats->LateCollisions = mib->tx_late_collisions;
-	mac_stats->FramesAbortedDueToXSColls = mib->tx_aborted_errors;
-	/* mac_stats->FramesLostDueToIntMACXmitError */
-	/* mac_stats->CarrierSenseErrors */
-	mac_stats->OctetsReceivedOK = mib->rx_good_bytes;
-	/* mac_stats->FramesLostDueToIntMACRcvError */
-	mac_stats->MulticastFramesXmittedOK = mib->tx_multicast;
-	mac_stats->BroadcastFramesXmittedOK = mib->tx_broadcast;
-	/* mac_stats->FramesWithExcessiveDeferral */
-	mac_stats->MulticastFramesReceivedOK = mib->rx_multicast;
-	mac_stats->BroadcastFramesReceivedOK = mib->rx_broadcast;
-	/* mac_stats->InRangeLengthErrors */
-	/* mac_stats->OutOfRangeLengthField */
-	mac_stats->FrameTooLongErrors = mib->rx_oversize_errors;
-}
-
-static void
-yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
-			      struct ethtool_eth_ctrl_stats *ctrl_stats)
-{
-	struct yt921x_priv *priv = to_yt921x_priv(ds);
-	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
-
-	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
-	mutex_unlock(&priv->reg_lock);
-
-	ctrl_stats->MACControlFramesTransmitted = mib->tx_pause;
-	ctrl_stats->MACControlFramesReceived = mib->rx_pause;
-	/* ctrl_stats->UnsupportedOpcodesReceived */
-}
-
-static const struct ethtool_rmon_hist_range yt921x_rmon_ranges[] = {
-	{ 0, 64 },
-	{ 65, 127 },
-	{ 128, 255 },
-	{ 256, 511 },
-	{ 512, 1023 },
-	{ 1024, 1518 },
-	{ 1519, YT921X_FRAME_SIZE_MAX },
-	{}
-};
-
-static void
-yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
-			  struct ethtool_rmon_stats *rmon_stats,
-			  const struct ethtool_rmon_hist_range **ranges)
-{
-	struct yt921x_priv *priv = to_yt921x_priv(ds);
-	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
-
-	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
-	mutex_unlock(&priv->reg_lock);
-
-	*ranges = yt921x_rmon_ranges;
-
-	rmon_stats->undersize_pkts = mib->rx_undersize_errors;
-	rmon_stats->oversize_pkts = mib->rx_oversize_errors;
-	rmon_stats->fragments = mib->rx_alignment_errors;
-	/* rmon_stats->jabbers */
-
-	rmon_stats->hist[0] = mib->rx_64byte;
-	rmon_stats->hist[1] = mib->rx_65_127byte;
-	rmon_stats->hist[2] = mib->rx_128_255byte;
-	rmon_stats->hist[3] = mib->rx_256_511byte;
-	rmon_stats->hist[4] = mib->rx_512_1023byte;
-	rmon_stats->hist[5] = mib->rx_1024_1518byte;
-	rmon_stats->hist[6] = mib->rx_jumbo;
-
-	rmon_stats->hist_tx[0] = mib->tx_64byte;
-	rmon_stats->hist_tx[1] = mib->tx_65_127byte;
-	rmon_stats->hist_tx[2] = mib->tx_128_255byte;
-	rmon_stats->hist_tx[3] = mib->tx_256_511byte;
-	rmon_stats->hist_tx[4] = mib->tx_512_1023byte;
-	rmon_stats->hist_tx[5] = mib->tx_1024_1518byte;
-	rmon_stats->hist_tx[6] = mib->tx_jumbo;
-}
-
-static void
-yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
-		       struct rtnl_link_stats64 *stats)
-{
-	struct yt921x_priv *priv = to_yt921x_priv(ds);
-	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
-
-	stats->rx_length_errors = mib->rx_undersize_errors +
-				  mib->rx_fragment_errors;
-	stats->rx_over_errors = mib->rx_oversize_errors;
-	stats->rx_crc_errors = mib->rx_crc_errors;
-	stats->rx_frame_errors = mib->rx_alignment_errors;
-	/* stats->rx_fifo_errors */
-	/* stats->rx_missed_errors */
-
-	stats->tx_aborted_errors = mib->tx_aborted_errors;
-	/* stats->tx_carrier_errors */
-	stats->tx_fifo_errors = mib->tx_undersize_errors;
-	/* stats->tx_heartbeat_errors */
-	stats->tx_window_errors = mib->tx_late_collisions;
-
-	stats->rx_packets = pp->rx_frames;
-	stats->tx_packets = pp->tx_frames;
-	stats->rx_bytes = mib->rx_good_bytes - ETH_FCS_LEN * stats->rx_packets;
-	stats->tx_bytes = mib->tx_good_bytes - ETH_FCS_LEN * stats->tx_packets;
-	stats->rx_errors = stats->rx_length_errors + stats->rx_over_errors +
-			   stats->rx_crc_errors + stats->rx_frame_errors;
-	stats->tx_errors = stats->tx_aborted_errors + stats->tx_fifo_errors +
-			   stats->tx_window_errors;
-	stats->rx_dropped = mib->rx_dropped;
-	/* stats->tx_dropped */
-	stats->multicast = mib->rx_multicast;
-	stats->collisions = mib->tx_collisions;
-}
-
-static void
-yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
-			   struct ethtool_pause_stats *pause_stats)
-{
-	struct yt921x_priv *priv = to_yt921x_priv(ds);
-	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
-
-	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
-	mutex_unlock(&priv->reg_lock);
-
-	pause_stats->tx_pause_frames = mib->tx_pause;
-	pause_stats->rx_pause_frames = mib->rx_pause;
-}
-
 static int
 yt921x_set_eee(struct yt921x_priv *priv, int port, struct ethtool_keee *e)
 {

@@ -4749,7 +4387,7 @@ static int yt921x_mdio_probe(struct mdio_device *mdiodev)
 		struct yt921x_port *pp = &priv->ports[i];
 
 		pp->index = i;
-		INIT_DELAYED_WORK(&pp->mib_read, yt921x_poll_mib);
+		INIT_DELAYED_WORK(&pp->mib_read, yt921x_mib_poll);
 	}
 
 	ds = &priv->ds;

@@ -167,69 +167,6 @@
 #define YT921X_EEE_CTRL			0xb0000
 #define  YT921X_EEE_CTRL_ENn(port)		BIT(port)
 
-#define YT921X_MIB_CTRL			0xc0004
-#define  YT921X_MIB_CTRL_CLEAN			BIT(30)
-#define  YT921X_MIB_CTRL_PORT_M			GENMASK(6, 3)
-#define   YT921X_MIB_CTRL_PORT(x)			FIELD_PREP(YT921X_MIB_CTRL_PORT_M, (x))
-#define  YT921X_MIB_CTRL_ONE_PORT		BIT(1)
-#define  YT921X_MIB_CTRL_ALL_PORT		BIT(0)
-#define YT921X_MIBn_DATA0(port)		(0xc0100 + 0x100 * (port))
-#define YT921X_MIBn_DATAm(port, x)	(YT921X_MIBn_DATA0(port) + 4 * (x))
-#define  YT921X_MIB_DATA_RX_BROADCAST		0x00
-#define  YT921X_MIB_DATA_RX_PAUSE		0x04
-#define  YT921X_MIB_DATA_RX_MULTICAST		0x08
-#define  YT921X_MIB_DATA_RX_CRC_ERR		0x0c
-
-#define  YT921X_MIB_DATA_RX_ALIGN_ERR		0x10
-#define  YT921X_MIB_DATA_RX_UNDERSIZE_ERR	0x14
-#define  YT921X_MIB_DATA_RX_FRAG_ERR		0x18
-#define  YT921X_MIB_DATA_RX_PKT_SZ_64		0x1c
-
-#define  YT921X_MIB_DATA_RX_PKT_SZ_65_TO_127	0x20
-#define  YT921X_MIB_DATA_RX_PKT_SZ_128_TO_255	0x24
-#define  YT921X_MIB_DATA_RX_PKT_SZ_256_TO_511	0x28
-#define  YT921X_MIB_DATA_RX_PKT_SZ_512_TO_1023	0x2c
-
-#define  YT921X_MIB_DATA_RX_PKT_SZ_1024_TO_1518	0x30
-#define  YT921X_MIB_DATA_RX_PKT_SZ_1519_TO_MAX	0x34
-/* 0x38: unused */
-#define  YT921X_MIB_DATA_RX_GOOD_BYTES		0x3c
-
-/* 0x40: 64 bytes */
-#define  YT921X_MIB_DATA_RX_BAD_BYTES		0x44
-/* 0x48: 64 bytes */
-#define  YT921X_MIB_DATA_RX_OVERSIZE_ERR	0x4c
-
-#define  YT921X_MIB_DATA_RX_DROPPED		0x50
-#define  YT921X_MIB_DATA_TX_BROADCAST		0x54
-#define  YT921X_MIB_DATA_TX_PAUSE		0x58
-#define  YT921X_MIB_DATA_TX_MULTICAST		0x5c
-
-#define  YT921X_MIB_DATA_TX_UNDERSIZE_ERR	0x60
-#define  YT921X_MIB_DATA_TX_PKT_SZ_64		0x64
-#define  YT921X_MIB_DATA_TX_PKT_SZ_65_TO_127	0x68
-#define  YT921X_MIB_DATA_TX_PKT_SZ_128_TO_255	0x6c
-
-#define  YT921X_MIB_DATA_TX_PKT_SZ_256_TO_511	0x70
-#define  YT921X_MIB_DATA_TX_PKT_SZ_512_TO_1023	0x74
-#define  YT921X_MIB_DATA_TX_PKT_SZ_1024_TO_1518	0x78
-#define  YT921X_MIB_DATA_TX_PKT_SZ_1519_TO_MAX	0x7c
-
-/* 0x80: unused */
-#define  YT921X_MIB_DATA_TX_GOOD_BYTES		0x84
-/* 0x88: 64 bytes */
-#define  YT921X_MIB_DATA_TX_COLLISION		0x8c
-
-#define  YT921X_MIB_DATA_TX_EXCESSIVE_COLLISION	0x90
-#define  YT921X_MIB_DATA_TX_MULTIPLE_COLLISION	0x94
-#define  YT921X_MIB_DATA_TX_SINGLE_COLLISION	0x98
-#define  YT921X_MIB_DATA_TX_PKT			0x9c
-
-#define  YT921X_MIB_DATA_TX_DEFERRED		0xa0
-#define  YT921X_MIB_DATA_TX_LATE_COLLISION	0xa4
-#define  YT921X_MIB_DATA_RX_OAM			0xa8
-#define  YT921X_MIB_DATA_TX_OAM			0xac
-
 #define YT921X_EDATA_CTRL		0xe0000
 #define  YT921X_EDATA_CTRL_ADDR_M		GENMASK(15, 8)
 #define   YT921X_EDATA_CTRL_ADDR(x)			FIELD_PREP(YT921X_EDATA_CTRL_ADDR_M, (x))

@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#include "chip.h"
+#include "mib.h"
+#include "smi.h"
+
+struct yt921x_mib_desc {
+	unsigned char size;
+	unsigned char offset;
+	const char *name;
+};
+
+#define MIB_DESC(_size, _offset, _name) {_size, _offset, _name}
+
+/* Must agree with yt921x_mib
+ *
+ * Unstructured fields (name != NULL) will appear in get_ethtool_stats(),
+ * structured go to their *_stats() methods, but we need their sizes and offsets
+ * to perform 32bit MIB overflow wraparound.
+ */
+static const struct yt921x_mib_desc yt921x_mib_descs[] = {
+	MIB_DESC(1, YT921X_MIB_DATA_RX_BROADCAST, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PAUSE, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_MULTICAST, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_CRC_ERR, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_RX_ALIGN_ERR, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_UNDERSIZE_ERR, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_FRAG_ERR, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_64, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_65_TO_127, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_128_TO_255, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_256_TO_511, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_512_TO_1023, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_1024_TO_1518, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_PKT_SZ_1519_TO_MAX, NULL),
+	MIB_DESC(2, YT921X_MIB_DATA_RX_GOOD_BYTES, NULL),
+
+	MIB_DESC(2, YT921X_MIB_DATA_RX_BAD_BYTES, "RxBadBytes"),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_OVERSIZE_ERR, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_RX_DROPPED, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_BROADCAST, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PAUSE, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_MULTICAST, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_TX_UNDERSIZE_ERR, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_64, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_65_TO_127, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_128_TO_255, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_256_TO_511, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_512_TO_1023, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_1024_TO_1518, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT_SZ_1519_TO_MAX, NULL),
+
+	MIB_DESC(2, YT921X_MIB_DATA_TX_GOOD_BYTES, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_COLLISION, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_TX_EXCESSIVE_COLLISION, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_MULTIPLE_COLLISION, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_SINGLE_COLLISION, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_PKT, NULL),
+
+	MIB_DESC(1, YT921X_MIB_DATA_TX_DEFERRED, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_LATE_COLLISION, NULL),
+	MIB_DESC(1, YT921X_MIB_DATA_RX_OAM, "RxOAM"),
+	MIB_DESC(1, YT921X_MIB_DATA_TX_OAM, "TxOAM"),
+};
+
+/* The interval should be small enough to avoid overflow of 32bit MIBs.
+ *
+ * Until we can read MIBs from stats64 call directly (i.e. sleep
+ * there), we have to poll stats more frequently then it is actually needed.
+ * For overflow protection, normally, 100 sec interval should have been OK.
+ */
+#define YT921X_STATS_INTERVAL_JIFFIES	(3 * HZ)
+
+#define to_yt921x_priv(_ds) container_of_const(_ds, struct yt921x_priv, ds)
+#define to_device(priv) ((priv)->ds.dev)
+
+/* Read and handle overflow of 32bit MIBs. MIB buffer must be zeroed before. */
+static int yt921x_mib_read(struct yt921x_priv *priv, int port)
+{
+	struct yt921x_port *pp = &priv->ports[port];
+	struct device *dev = to_device(priv);
+	struct yt921x_mib *mib = &pp->mib;
+	int res = 0;
+
+	/* Reading of yt921x_port::mib is not protected by a lock and it's vain
+	 * to keep its consistency, since we have to read registers one by one
+	 * and there is no way to make a snapshot of MIB stats.
+	 *
+	 * Writing (by this function only) is and should be protected by
+	 * reg_lock.
+	 */
+
+	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
+		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
+		u32 reg = YT921X_MIBn_DATA0(port) + desc->offset;
+		u64 *valp = &((u64 *)mib)[i];
+		u32 val0;
+		u64 val;
+
+		res = yt921x_reg_read(priv, reg, &val0);
+		if (res)
+			break;
+
+		if (desc->size <= 1) {
+			u64 old_val = *valp;
+
+			val = (old_val & ~(u64)U32_MAX) | val0;
+			if (val < old_val)
+				val += 1ull << 32;
+		} else {
+			u32 val1;
+
+			res = yt921x_reg_read(priv, reg + 4, &val1);
+			if (res)
+				break;
+			val = ((u64)val1 << 32) | val0;
+		}
+
+		WRITE_ONCE(*valp, val);
+	}
+
+	pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte +
+			mib->rx_128_255byte + mib->rx_256_511byte +
+			mib->rx_512_1023byte + mib->rx_1024_1518byte +
+			mib->rx_jumbo;
+	pp->tx_frames = mib->tx_64byte + mib->tx_65_127byte +
+			mib->tx_128_255byte + mib->tx_256_511byte +
+			mib->tx_512_1023byte + mib->tx_1024_1518byte +
+			mib->tx_jumbo;
+
+	if (res)
+		dev_err(dev, "Failed to %s port %d: %i\n", "read stats for",
+			port, res);
+	return res;
+}
+
+void yt921x_mib_poll(struct work_struct *work)
+{
+	struct yt921x_port *pp = container_of_const(work, struct yt921x_port,
+						    mib_read.work);
+	struct yt921x_priv *priv = (void *)(pp - pp->index) -
+				   offsetof(struct yt921x_priv, ports);
+	unsigned long delay = YT921X_STATS_INTERVAL_JIFFIES;
+	int port = pp->index;
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_mib_read(priv, port);
+	mutex_unlock(&priv->reg_lock);
+	if (res)
+		delay *= 4;
+
+	schedule_delayed_work(&pp->mib_read, delay);
+}
+
+void
+yt921x_dsa_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+		       uint8_t *data)
+{
+	if (stringset != ETH_SS_STATS)
+		return;
+
+	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
+		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
+
+		if (desc->name)
+			ethtool_puts(&data, desc->name);
+	}
+}
+
+void
+yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_mib *mib = &pp->mib;
+	size_t j;
+
+	mutex_lock(&priv->reg_lock);
+	yt921x_mib_read(priv, port);
+	mutex_unlock(&priv->reg_lock);
+
+	j = 0;
+	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
+		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
+
+		if (!desc->name)
+			continue;
+
+		data[j] = ((u64 *)mib)[i];
+		j++;
+	}
+}
+
+int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset)
+{
+	int cnt = 0;
+
+	if (sset != ETH_SS_STATS)
+		return 0;
+
+	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
+		const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
+
+		if (desc->name)
+			cnt++;
+	}
+
+	return cnt;
+}
+
+void
+yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
+			     struct ethtool_eth_mac_stats *mac_stats)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_mib *mib = &pp->mib;
+
+	mutex_lock(&priv->reg_lock);
+	yt921x_mib_read(priv, port);
+	mutex_unlock(&priv->reg_lock);
+
+	mac_stats->FramesTransmittedOK = pp->tx_frames;
+	mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
+	mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
+	mac_stats->FramesReceivedOK = pp->rx_frames;
+	mac_stats->FrameCheckSequenceErrors = mib->rx_crc_errors;
+	mac_stats->AlignmentErrors = mib->rx_alignment_errors;
+	mac_stats->OctetsTransmittedOK = mib->tx_good_bytes;
+	mac_stats->FramesWithDeferredXmissions = mib->tx_deferred;
+	mac_stats->LateCollisions = mib->tx_late_collisions;
+	mac_stats->FramesAbortedDueToXSColls = mib->tx_aborted_errors;
+	/* mac_stats->FramesLostDueToIntMACXmitError */
+	/* mac_stats->CarrierSenseErrors */
+	mac_stats->OctetsReceivedOK = mib->rx_good_bytes;
+	/* mac_stats->FramesLostDueToIntMACRcvError */
+	mac_stats->MulticastFramesXmittedOK = mib->tx_multicast;
+	mac_stats->BroadcastFramesXmittedOK = mib->tx_broadcast;
+	/* mac_stats->FramesWithExcessiveDeferral */
+	mac_stats->MulticastFramesReceivedOK = mib->rx_multicast;
+	mac_stats->BroadcastFramesReceivedOK = mib->rx_broadcast;
+	/* mac_stats->InRangeLengthErrors */
+	/* mac_stats->OutOfRangeLengthField */
+	mac_stats->FrameTooLongErrors = mib->rx_oversize_errors;
+}
+
+void
+yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
+			      struct ethtool_eth_ctrl_stats *ctrl_stats)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_mib *mib = &pp->mib;
+
+	mutex_lock(&priv->reg_lock);
+	yt921x_mib_read(priv, port);
+	mutex_unlock(&priv->reg_lock);
+
+	ctrl_stats->MACControlFramesTransmitted = mib->tx_pause;
+	ctrl_stats->MACControlFramesReceived = mib->rx_pause;
+	/* ctrl_stats->UnsupportedOpcodesReceived */
+}
+
+static const struct ethtool_rmon_hist_range yt921x_rmon_ranges[] = {
+	{ 0, 64 },
+	{ 65, 127 },
+	{ 128, 255 },
+	{ 256, 511 },
+	{ 512, 1023 },
+	{ 1024, 1518 },
+	{ 1519, YT921X_FRAME_SIZE_MAX },
+	{}
+};
+
+void
+yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
+			  struct ethtool_rmon_stats *rmon_stats,
+			  const struct ethtool_rmon_hist_range **ranges)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_mib *mib = &pp->mib;
+
+	mutex_lock(&priv->reg_lock);
+	yt921x_mib_read(priv, port);
+	mutex_unlock(&priv->reg_lock);
+
+	*ranges = yt921x_rmon_ranges;
+
+	rmon_stats->undersize_pkts = mib->rx_undersize_errors;
+	rmon_stats->oversize_pkts = mib->rx_oversize_errors;
+	rmon_stats->fragments = mib->rx_alignment_errors;
+	/* rmon_stats->jabbers */
+
+	rmon_stats->hist[0] = mib->rx_64byte;
+	rmon_stats->hist[1] = mib->rx_65_127byte;
+	rmon_stats->hist[2] = mib->rx_128_255byte;
+	rmon_stats->hist[3] = mib->rx_256_511byte;
+	rmon_stats->hist[4] = mib->rx_512_1023byte;
+	rmon_stats->hist[5] = mib->rx_1024_1518byte;
+	rmon_stats->hist[6] = mib->rx_jumbo;
+
+	rmon_stats->hist_tx[0] = mib->tx_64byte;
+	rmon_stats->hist_tx[1] = mib->tx_65_127byte;
+	rmon_stats->hist_tx[2] = mib->tx_128_255byte;
+	rmon_stats->hist_tx[3] = mib->tx_256_511byte;
+	rmon_stats->hist_tx[4] = mib->tx_512_1023byte;
+	rmon_stats->hist_tx[5] = mib->tx_1024_1518byte;
+	rmon_stats->hist_tx[6] = mib->tx_jumbo;
+}
+
+void
+yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
+		       struct rtnl_link_stats64 *stats)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_mib *mib = &pp->mib;
+
+	stats->rx_length_errors = mib->rx_undersize_errors +
+				  mib->rx_fragment_errors;
+	stats->rx_over_errors = mib->rx_oversize_errors;
+	stats->rx_crc_errors = mib->rx_crc_errors;
+	stats->rx_frame_errors = mib->rx_alignment_errors;
+	/* stats->rx_fifo_errors */
+	/* stats->rx_missed_errors */
+
+	stats->tx_aborted_errors = mib->tx_aborted_errors;
+	/* stats->tx_carrier_errors */
+	stats->tx_fifo_errors = mib->tx_undersize_errors;
+	/* stats->tx_heartbeat_errors */
+	stats->tx_window_errors = mib->tx_late_collisions;
+
+	stats->rx_packets = pp->rx_frames;
+	stats->tx_packets = pp->tx_frames;
+	stats->rx_bytes = mib->rx_good_bytes - ETH_FCS_LEN * stats->rx_packets;
+	stats->tx_bytes = mib->tx_good_bytes - ETH_FCS_LEN * stats->tx_packets;
+	stats->rx_errors = stats->rx_length_errors + stats->rx_over_errors +
+			   stats->rx_crc_errors + stats->rx_frame_errors;
+	stats->tx_errors = stats->tx_aborted_errors + stats->tx_fifo_errors +
+			   stats->tx_window_errors;
+	stats->rx_dropped = mib->rx_dropped;
+	/* stats->tx_dropped */
+	stats->multicast = mib->rx_multicast;
+	stats->collisions = mib->tx_collisions;
+}
+
+void
+yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
+			   struct ethtool_pause_stats *pause_stats)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_mib *mib = &pp->mib;
+
+	mutex_lock(&priv->reg_lock);
+	yt921x_mib_read(priv, port);
+	mutex_unlock(&priv->reg_lock);
+
+	pause_stats->tx_pause_frames = mib->tx_pause;
+	pause_stats->rx_pause_frames = mib->rx_pause;
+}