[PATCH net-next v4 0/7] net: dsa: motorcomm: MIB fixup

[PATCH net-next v4 0/7] net: dsa: motorcomm: MIB fixup

[David Yang]

Fix (theoretical) MIB inconsistency and prepare for new devices. No new
features are introduced.

v4:
  - reuse port_to_priv helper
  - re-enable delayed_work on port_setup
  - disable preemption for u64_stats_set
v3: https://lore.kernel.org/r/20260906131414.2683362-1-mmyangfl@gmail.com
  - fix build errors
  - fix logic error on MIB buffer creation
v2: https://lore.kernel.org/r/20260904162952.709368-1-mmyangfl@gmail.com
  - split patches
v1: https://lore.kernel.org/r/20260903143514.532023-1-mmyangfl@gmail.com

David Yang (7):
  net: dsa: motorcomm: Hoist port_to_priv helper into chip.h
  net: dsa: motorcomm: Rename MIB stuff
  net: dsa: motorcomm: Split MIB buffers
  net: dsa: motorcomm: Split MIB module
  net: dsa: motorcomm: Use u64_stats_t for MIB stats
  net: dsa: motorcomm: Fix MIB synchronization
  net: dsa: motorcomm: Use safe 64-bit counter reader

 drivers/net/dsa/motorcomm/Makefile |   1 +
 drivers/net/dsa/motorcomm/chip.c   | 413 +++------------------------
 drivers/net/dsa/motorcomm/chip.h   | 125 +--------
 drivers/net/dsa/motorcomm/leds.c   |  14 +-
 drivers/net/dsa/motorcomm/mib.c    | 431 +++++++++++++++++++++++++++++
 drivers/net/dsa/motorcomm/mib.h    | 167 +++++++++++
 drivers/net/dsa/motorcomm/smi.c    |  30 ++
 drivers/net/dsa/motorcomm/smi.h    |   2 +
 8 files changed, 683 insertions(+), 500 deletions(-)
 create mode 100644 drivers/net/dsa/motorcomm/mib.c
 create mode 100644 drivers/net/dsa/motorcomm/mib.h

-- 
2.53.0

[PATCH net-next v4 1/7] net: dsa: motorcomm: Hoist port_to_priv helper into chip.h

[David Yang]

yt921x_poll_mib() open-codes the same container_of_const() expression
that leds.c defines as to_yt921x_priv(). Move the macro to chip.h as
yt921x_port_to_priv() so both files use one definition.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 drivers/net/dsa/motorcomm/chip.c |  3 +--
 drivers/net/dsa/motorcomm/chip.h |  3 +++
 drivers/net/dsa/motorcomm/leds.c | 14 ++++++--------
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index 8b0ac5fc8c8b..38e7879a9f1a 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -608,9 +608,8 @@ 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;
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 	int port = pp->index;
 	int res;
 
diff --git a/drivers/net/dsa/motorcomm/chip.h b/drivers/net/dsa/motorcomm/chip.h
index 83cd454955dd..9cd1010eb970 100644
--- a/drivers/net/dsa/motorcomm/chip.h
+++ b/drivers/net/dsa/motorcomm/chip.h
@@ -989,4 +989,7 @@ struct yt921x_priv {
 	struct yt921x_acl_blk *acl_blks[YT921X_ACL_BLK_NUM];
 };
 
+#define yt921x_port_to_priv(pp) \
+	container_of_const((pp), struct yt921x_priv, ports[(pp)->index])
+
 #endif
diff --git a/drivers/net/dsa/motorcomm/leds.c b/drivers/net/dsa/motorcomm/leds.c
index 87a6b9cf6068..dd5b3684250d 100644
--- a/drivers/net/dsa/motorcomm/leds.c
+++ b/drivers/net/dsa/motorcomm/leds.c
@@ -12,8 +12,6 @@
 #define to_yt921x_led(led_cdev) \
 	container_of_const((led_cdev), struct yt921x_led, cdev)
 #define to_yt921x_port(led) ((led)->port)
-#define to_yt921x_priv(pp) \
-	container_of_const((pp), struct yt921x_priv, ports[(pp)->index])
 #define to_device(priv) ((priv)->ds.dev)
 
 static u32 yt921x_led_regaddr(struct yt921x_priv *priv, int port, int group)
@@ -321,7 +319,7 @@ yt921x_cled_brightness_set_blocking(struct led_classdev *led_cdev,
 {
 	struct yt921x_led *led = to_yt921x_led(led_cdev);
 	struct yt921x_port *pp = to_yt921x_port(led);
-	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 	int res;
 
 	mutex_lock(&priv->reg_lock);
@@ -337,7 +335,7 @@ yt921x_cled_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
 {
 	struct yt921x_led *led = to_yt921x_led(led_cdev);
 	struct yt921x_port *pp = to_yt921x_port(led);
-	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 	int res;
 
 	mutex_lock(&priv->reg_lock);
@@ -353,7 +351,7 @@ yt921x_cled_hw_control_get_device(struct led_classdev *led_cdev)
 {
 	struct yt921x_led *led = to_yt921x_led(led_cdev);
 	struct yt921x_port *pp = to_yt921x_port(led);
-	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 	struct dsa_port *dp;
 
 	dp = dsa_to_port(&priv->ds, pp->index);
@@ -374,7 +372,7 @@ yt921x_cled_hw_control_is_supported(struct led_classdev *led_cdev,
 {
 	struct yt921x_led *led = to_yt921x_led(led_cdev);
 	struct yt921x_port *pp = to_yt921x_port(led);
-	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 
 	if (yt921x_led_trigger_is_supported(priv, pp->index, led->group, flags))
 		return 0;
@@ -386,7 +384,7 @@ yt921x_cled_hw_control_get(struct led_classdev *led_cdev, unsigned long *flagsp)
 {
 	struct yt921x_led *led = to_yt921x_led(led_cdev);
 	struct yt921x_port *pp = to_yt921x_port(led);
-	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 	int res;
 
 	mutex_lock(&priv->reg_lock);
@@ -401,7 +399,7 @@ yt921x_cled_hw_control_set(struct led_classdev *led_cdev, unsigned long flags)
 {
 	struct yt921x_led *led = to_yt921x_led(led_cdev);
 	struct yt921x_port *pp = to_yt921x_port(led);
-	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 	int res;
 
 	mutex_lock(&priv->reg_lock);
-- 
2.53.0

Re: [PATCH net-next v4 1/7] net: dsa: motorcomm: Hoist port_to_priv helper into chip.h

[Andrew Lunn]

On Tue, Sep 22, 2026 at 04:30:18AM +0800, David Yang wrote:
> yt921x_poll_mib() open-codes the same container_of_const() expression
> that leds.c defines as to_yt921x_priv(). Move the macro to chip.h as
> yt921x_port_to_priv() so both files use one definition.
> 
> Signed-off-by: David Yang <mmyangfl@gmail.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

[PATCH net-next v4 2/7] net: dsa: motorcomm: Rename MIB stuff

[David Yang]

Rename them in preparation of major MIB refactor.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/chip.c | 34 ++++++++++++++++----------------
 drivers/net/dsa/motorcomm/chip.h |  4 ++--
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index 38e7879a9f1a..d0b25ded2447 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -38,7 +38,7 @@ struct yt921x_mib_desc {
 #define MIB_DESC(_size, _offset, _name) \
 	{_size, _offset, _name}
 
-/* Must agree with yt921x_mib
+/* Must agree with yt921x_mib_stats
  *
  * Unstructured fields (name != NULL) will appear in get_ethtool_stats(),
  * structured go to their *_stats() methods, but we need their sizes and offsets
@@ -545,11 +545,11 @@ yt921x_mbus_ext_init(struct yt921x_priv *priv, struct device_node *mnp)
 }
 
 /* Read and handle overflow of 32bit MIBs. MIB buffer must be zeroed before. */
-static int yt921x_read_mib(struct yt921x_priv *priv, int port)
+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;
+	struct yt921x_mib_stats *mib = &pp->mib;
 	int res = 0;
 
 	/* Reading of yt921x_port::mib is not protected by a lock and it's vain
@@ -604,7 +604,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
 	return res;
 }
 
-static void yt921x_poll_mib(struct work_struct *work)
+static void yt921x_mib_poll(struct work_struct *work)
 {
 	struct yt921x_port *pp = container_of_const(work, struct yt921x_port,
 						    mib_read.work);
@@ -614,7 +614,7 @@ static void yt921x_poll_mib(struct work_struct *work)
 	int res;
 
 	mutex_lock(&priv->reg_lock);
-	res = yt921x_read_mib(priv, port);
+	res = yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 	if (res)
 		delay *= 4;
@@ -642,11 +642,11 @@ 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;
+	struct yt921x_mib_stats *mib = &pp->mib;
 	size_t j;
 
 	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
+	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
 	j = 0;
@@ -684,10 +684,10 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
+	struct yt921x_mib_stats *mib = &pp->mib;
 
 	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
+	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
 	mac_stats->FramesTransmittedOK = pp->tx_frames;
@@ -720,10 +720,10 @@ yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
+	struct yt921x_mib_stats *mib = &pp->mib;
 
 	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
+	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
 	ctrl_stats->MACControlFramesTransmitted = mib->tx_pause;
@@ -749,10 +749,10 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
+	struct yt921x_mib_stats *mib = &pp->mib;
 
 	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
+	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
 	*ranges = yt921x_rmon_ranges;
@@ -785,7 +785,7 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
+	struct yt921x_mib_stats *mib = &pp->mib;
 
 	stats->rx_length_errors = mib->rx_undersize_errors +
 				  mib->rx_fragment_errors;
@@ -821,10 +821,10 @@ yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib *mib = &pp->mib;
+	struct yt921x_mib_stats *mib = &pp->mib;
 
 	mutex_lock(&priv->reg_lock);
-	yt921x_read_mib(priv, port);
+	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
 	pause_stats->tx_pause_frames = mib->tx_pause;
@@ -4748,7 +4748,7 @@ 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;
diff --git a/drivers/net/dsa/motorcomm/chip.h b/drivers/net/dsa/motorcomm/chip.h
index 9cd1010eb970..9205be423e39 100644
--- a/drivers/net/dsa/motorcomm/chip.h
+++ b/drivers/net/dsa/motorcomm/chip.h
@@ -861,7 +861,7 @@ enum yt921x_fdb_entry_status {
 #define yt921x_port_is_internal(port) ((port) < 8)
 #define yt921x_port_is_external(port) ((port) == 8 || (port) == 9)
 
-struct yt921x_mib {
+struct yt921x_mib_stats {
 	u64 rx_broadcast;
 	u64 rx_pause;
 	u64 rx_multicast;
@@ -940,7 +940,7 @@ struct yt921x_port {
 	bool isolated;
 
 	struct delayed_work mib_read;
-	struct yt921x_mib mib;
+	struct yt921x_mib_stats mib;
 	u64 rx_frames;
 	u64 tx_frames;
 
-- 
2.53.0

[PATCH net-next v4 3/7] net: dsa: motorcomm: Split MIB buffers

[David Yang]

With MIB improvement introduced later, struct yt921x_priv will be over
20k which is not very good for a single kmalloc(). Dynamically allocate
the MIB structures to reduce the size of struct yt921x_priv, and do not
waste memory on dummy ports.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/chip.c | 115 ++++++++++++++++++++++++-------
 drivers/net/dsa/motorcomm/chip.h |  16 +++--
 2 files changed, 100 insertions(+), 31 deletions(-)

diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index d0b25ded2447..ad06d894b001 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -549,10 +549,13 @@ 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_stats *mib = &pp->mib;
+	struct yt921x_mib *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
 	int res = 0;
 
-	/* Reading of yt921x_port::mib is not protected by a lock and it's vain
+	mib = &pm->stats;
+
+	/* Reading of yt921x_mib_stats 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.
 	 *
@@ -589,11 +592,11 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 		WRITE_ONCE(*valp, val);
 	}
 
-	pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte +
+	pm->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 +
+	pm->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;
@@ -606,8 +609,9 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 
 static void yt921x_mib_poll(struct work_struct *work)
 {
-	struct yt921x_port *pp = container_of_const(work, struct yt921x_port,
-						    mib_read.work);
+	struct yt921x_mib *pm = container_of_const(work, struct yt921x_mib,
+						   work.work);
+	struct yt921x_port *pp = pm->port;
 	unsigned long delay = YT921X_STATS_INTERVAL_JIFFIES;
 	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
 	int port = pp->index;
@@ -619,7 +623,7 @@ static void yt921x_mib_poll(struct work_struct *work)
 	if (res)
 		delay *= 4;
 
-	schedule_delayed_work(&pp->mib_read, delay);
+	schedule_delayed_work(&pm->work, delay);
 }
 
 static void
@@ -642,9 +646,14 @@ 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_stats *mib = &pp->mib;
+	struct yt921x_mib *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
 	size_t j;
 
+	if (!pm)
+		return;
+	mib = &pm->stats;
+
 	mutex_lock(&priv->reg_lock);
 	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
@@ -684,16 +693,21 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib_stats *mib = &pp->mib;
+	struct yt921x_mib *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
 	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
-	mac_stats->FramesTransmittedOK = pp->tx_frames;
+	mac_stats->FramesTransmittedOK = pm->tx_frames;
 	mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
 	mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
-	mac_stats->FramesReceivedOK = pp->rx_frames;
+	mac_stats->FramesReceivedOK = pm->rx_frames;
 	mac_stats->FrameCheckSequenceErrors = mib->rx_crc_errors;
 	mac_stats->AlignmentErrors = mib->rx_alignment_errors;
 	mac_stats->OctetsTransmittedOK = mib->tx_good_bytes;
@@ -720,7 +734,12 @@ yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib_stats *mib = &pp->mib;
+	struct yt921x_mib *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
 	yt921x_mib_read(priv, port);
@@ -749,7 +768,12 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib_stats *mib = &pp->mib;
+	struct yt921x_mib *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
 	yt921x_mib_read(priv, port);
@@ -785,7 +809,12 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib_stats *mib = &pp->mib;
+	struct yt921x_mib *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
 
 	stats->rx_length_errors = mib->rx_undersize_errors +
 				  mib->rx_fragment_errors;
@@ -801,8 +830,8 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
 	/* 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_packets = pm->rx_frames;
+	stats->tx_packets = pm->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 +
@@ -821,7 +850,12 @@ yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
 	struct yt921x_port *pp = &priv->ports[port];
-	struct yt921x_mib_stats *mib = &pp->mib;
+	struct yt921x_mib *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
 	yt921x_mib_read(priv, port);
@@ -3952,11 +3986,14 @@ yt921x_phylink_mac_link_down(struct phylink_config *config, unsigned int mode,
 {
 	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct yt921x_priv *priv = to_yt921x_priv(dp->ds);
+	struct yt921x_mib *pm;
 	int port = dp->index;
 	int res;
 
 	/* No need to sync; port control block is hold until device remove */
-	cancel_delayed_work(&priv->ports[port].mib_read);
+	pm = priv->ports[port].mib;
+	if (pm)
+		cancel_delayed_work(&pm->work);
 
 	mutex_lock(&priv->reg_lock);
 	res = yt921x_port_down(priv, port);
@@ -3975,6 +4012,7 @@ yt921x_phylink_mac_link_up(struct phylink_config *config,
 {
 	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct yt921x_priv *priv = to_yt921x_priv(dp->ds);
+	struct yt921x_mib *pm;
 	int port = dp->index;
 	int res;
 
@@ -3987,7 +4025,9 @@ yt921x_phylink_mac_link_up(struct phylink_config *config,
 		dev_err(dp->ds->dev, "Failed to %s port %d: %i\n", "bring up",
 			port, res);
 
-	schedule_delayed_work(&priv->ports[port].mib_read, 0);
+	pm = priv->ports[port].mib;
+	if (pm)
+		schedule_delayed_work(&pm->work, 0);
 }
 
 static void
@@ -4107,11 +4147,40 @@ yt921x_dsa_get_tag_protocol(struct dsa_switch *ds, int port,
 	return DSA_TAG_PROTO_YT921X;
 }
 
+static void yt921x_dsa_port_teardown(struct dsa_switch *ds, int port)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_mib *pm = pp->mib;
+
+	/* get_stats64() might not be synchronized with port_teardown(), hold
+	 * the MIB block till the device teardown
+	 */
+	if (pm)
+		disable_delayed_work_sync(&pm->work);
+}
+
 static int yt921x_dsa_port_setup(struct dsa_switch *ds, int port)
 {
 	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	struct yt921x_port *pp = &priv->ports[port];
+	struct device *dev = to_device(priv);
+	struct yt921x_mib *pm = pp->mib;
 	int res;
 
+	if (pm) {
+		enable_delayed_work(&pm->work);
+	} else if (BIT(port) & (priv->info->internal_mask |
+				priv->info->external_mask)) {
+		pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
+		if (!pm)
+			return -ENOMEM;
+		pp->mib = pm;
+
+		pm->port = pp;
+		INIT_DELAYED_WORK(&pm->work, yt921x_mib_poll);
+	}
+
 	mutex_lock(&priv->reg_lock);
 	res = yt921x_port_setup(priv, port);
 	mutex_unlock(&priv->reg_lock);
@@ -4666,6 +4735,7 @@ static const struct dsa_switch_ops yt921x_dsa_switch_ops = {
 	/* port */
 	.get_tag_protocol	= yt921x_dsa_get_tag_protocol,
 	.phylink_get_caps	= yt921x_dsa_phylink_get_caps,
+	.port_teardown		= yt921x_dsa_port_teardown,
 	.port_setup		= yt921x_dsa_port_setup,
 #if IS_ENABLED(CONFIG_DCB)
 	/* dscp */
@@ -4695,12 +4765,6 @@ static void yt921x_mdio_remove(struct mdio_device *mdiodev)
 	if (!priv)
 		return;
 
-	for (size_t i = ARRAY_SIZE(priv->ports); i-- > 0; ) {
-		struct yt921x_port *pp = &priv->ports[i];
-
-		disable_delayed_work_sync(&pp->mib_read);
-	}
-
 	dsa_unregister_switch(&priv->ds);
 
 	for (unsigned int i = 0; i < ARRAY_SIZE(priv->acl_blks); i++) {
@@ -4748,7 +4812,6 @@ 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_mib_poll);
 	}
 
 	ds = &priv->ds;
diff --git a/drivers/net/dsa/motorcomm/chip.h b/drivers/net/dsa/motorcomm/chip.h
index 9205be423e39..9f3c8af4f638 100644
--- a/drivers/net/dsa/motorcomm/chip.h
+++ b/drivers/net/dsa/motorcomm/chip.h
@@ -913,6 +913,15 @@ struct yt921x_mib_stats {
 	u64 tx_oam;
 };
 
+struct yt921x_mib {
+	struct yt921x_port *port;
+
+	struct delayed_work work;
+	struct yt921x_mib_stats stats;
+	u64 rx_frames;
+	u64 tx_frames;
+};
+
 struct yt921x_acl_entry {
 	u32 key[2];
 	u32 mask[2];
@@ -939,11 +948,6 @@ struct yt921x_port {
 	bool hairpin;
 	bool isolated;
 
-	struct delayed_work mib_read;
-	struct yt921x_mib_stats mib;
-	u64 rx_frames;
-	u64 tx_frames;
-
 #if IS_ENABLED(CONFIG_NET_DSA_YT921X_LEDS)
 	unsigned char led_duty;
 	unsigned short led_cycle;
@@ -953,6 +957,8 @@ struct yt921x_port {
 
 	struct yt921x_led *leds[YT921X_LED_GROUP_NUM];
 #endif
+
+	struct yt921x_mib *mib;
 };
 
 struct yt921x_reg_ops {
-- 
2.53.0

[PATCH net-next v4 4/7] net: dsa: motorcomm: Split MIB module

[David Yang]

yt922x is going to use a different MIB scheme, split it to reduce the
length of chip.c.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/Makefile |   1 +
 drivers/net/dsa/motorcomm/chip.c   | 397 +---------------------------
 drivers/net/dsa/motorcomm/chip.h   | 124 ---------
 drivers/net/dsa/motorcomm/mib.c    | 407 +++++++++++++++++++++++++++++
 drivers/net/dsa/motorcomm/mib.h    | 159 +++++++++++
 5 files changed, 568 insertions(+), 520 deletions(-)
 create mode 100644 drivers/net/dsa/motorcomm/mib.c
 create mode 100644 drivers/net/dsa/motorcomm/mib.h

diff --git a/drivers/net/dsa/motorcomm/Makefile b/drivers/net/dsa/motorcomm/Makefile
index aeb12cb91f93..5c2d34ec05fc 100644
--- a/drivers/net/dsa/motorcomm/Makefile
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -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
diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index ad06d894b001..34dbbdcea135 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -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_stats
- *
- * 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;
@@ -544,327 +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_mib_read(struct yt921x_priv *priv, int port)
-{
-	struct yt921x_port *pp = &priv->ports[port];
-	struct device *dev = to_device(priv);
-	struct yt921x_mib *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
-	int res = 0;
-
-	mib = &pm->stats;
-
-	/* Reading of yt921x_mib_stats 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);
-	}
-
-	pm->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;
-	pm->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_mib_poll(struct work_struct *work)
-{
-	struct yt921x_mib *pm = container_of_const(work, struct yt921x_mib,
-						   work.work);
-	struct yt921x_port *pp = pm->port;
-	unsigned long delay = YT921X_STATS_INTERVAL_JIFFIES;
-	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
-	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(&pm->work, 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 *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
-	size_t j;
-
-	if (!pm)
-		return;
-	mib = &pm->stats;
-
-	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++;
-	}
-}
-
-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 *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
-
-	if (!pm)
-		return;
-	mib = &pm->stats;
-
-	mutex_lock(&priv->reg_lock);
-	yt921x_mib_read(priv, port);
-	mutex_unlock(&priv->reg_lock);
-
-	mac_stats->FramesTransmittedOK = pm->tx_frames;
-	mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
-	mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
-	mac_stats->FramesReceivedOK = pm->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 *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
-
-	if (!pm)
-		return;
-	mib = &pm->stats;
-
-	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 },
-	{}
-};
-
-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 *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
-
-	if (!pm)
-		return;
-	mib = &pm->stats;
-
-	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;
-}
-
-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 *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
-
-	if (!pm)
-		return;
-	mib = &pm->stats;
-
-	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 = pm->rx_frames;
-	stats->tx_packets = pm->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 *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
-
-	if (!pm)
-		return;
-	mib = &pm->stats;
-
-	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;
-}
-
 static int
 yt921x_set_eee(struct yt921x_priv *priv, int port, struct ethtool_keee *e)
 {
diff --git a/drivers/net/dsa/motorcomm/chip.h b/drivers/net/dsa/motorcomm/chip.h
index 9f3c8af4f638..b2e39b70bf61 100644
--- a/drivers/net/dsa/motorcomm/chip.h
+++ b/drivers/net/dsa/motorcomm/chip.h
@@ -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))
@@ -861,67 +798,6 @@ enum yt921x_fdb_entry_status {
 #define yt921x_port_is_internal(port) ((port) < 8)
 #define yt921x_port_is_external(port) ((port) == 8 || (port) == 9)
 
-struct yt921x_mib_stats {
-	u64 rx_broadcast;
-	u64 rx_pause;
-	u64 rx_multicast;
-	u64 rx_crc_errors;
-
-	u64 rx_alignment_errors;
-	u64 rx_undersize_errors;
-	u64 rx_fragment_errors;
-	u64 rx_64byte;
-
-	u64 rx_65_127byte;
-	u64 rx_128_255byte;
-	u64 rx_256_511byte;
-	u64 rx_512_1023byte;
-
-	u64 rx_1024_1518byte;
-	u64 rx_jumbo;
-	u64 rx_good_bytes;
-
-	u64 rx_bad_bytes;
-	u64 rx_oversize_errors;
-
-	u64 rx_dropped;
-	u64 tx_broadcast;
-	u64 tx_pause;
-	u64 tx_multicast;
-
-	u64 tx_undersize_errors;
-	u64 tx_64byte;
-	u64 tx_65_127byte;
-	u64 tx_128_255byte;
-
-	u64 tx_256_511byte;
-	u64 tx_512_1023byte;
-	u64 tx_1024_1518byte;
-	u64 tx_jumbo;
-
-	u64 tx_good_bytes;
-	u64 tx_collisions;
-
-	u64 tx_aborted_errors;
-	u64 tx_multiple_collisions;
-	u64 tx_single_collisions;
-	u64 tx_good;
-
-	u64 tx_deferred;
-	u64 tx_late_collisions;
-	u64 rx_oam;
-	u64 tx_oam;
-};
-
-struct yt921x_mib {
-	struct yt921x_port *port;
-
-	struct delayed_work work;
-	struct yt921x_mib_stats stats;
-	u64 rx_frames;
-	u64 tx_frames;
-};
-
 struct yt921x_acl_entry {
 	u32 key[2];
 	u32 mask[2];
diff --git a/drivers/net/dsa/motorcomm/mib.c b/drivers/net/dsa/motorcomm/mib.c
new file mode 100644
index 000000000000..c2f7d7f83cd9
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/mib.c
@@ -0,0 +1,407 @@
+// 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 int size;
+	unsigned int offset;
+	const char *name;
+};
+
+#define MIB_DESC(_size, _offset, _name) \
+	{_size, _offset, _name}
+
+/* Must agree with yt921x_mib_stats
+ *
+ * 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 *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+	int res = 0;
+
+	mib = &pm->stats;
+
+	/* Reading of yt921x_mib_stats 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);
+	}
+
+	pm->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;
+	pm->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_mib *pm = container_of_const(work, struct yt921x_mib,
+						   work.work);
+	struct yt921x_port *pp = pm->port;
+	unsigned long delay = YT921X_STATS_INTERVAL_JIFFIES;
+	struct yt921x_priv *priv = yt921x_port_to_priv(pp);
+	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(&pm->work, 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 *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+	size_t j;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
+
+	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 *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
+
+	mutex_lock(&priv->reg_lock);
+	yt921x_mib_read(priv, port);
+	mutex_unlock(&priv->reg_lock);
+
+	mac_stats->FramesTransmittedOK = pm->tx_frames;
+	mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
+	mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
+	mac_stats->FramesReceivedOK = pm->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 *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
+
+	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 *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
+
+	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 *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
+
+	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 = pm->rx_frames;
+	stats->tx_packets = pm->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 *pm = pp->mib;
+	struct yt921x_mib_stats *mib;
+
+	if (!pm)
+		return;
+	mib = &pm->stats;
+
+	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;
+}
diff --git a/drivers/net/dsa/motorcomm/mib.h b/drivers/net/dsa/motorcomm/mib.h
new file mode 100644
index 000000000000..cfad0665baae
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/mib.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#ifndef _YT_MIB_H
+#define _YT_MIB_H
+
+#include <net/dsa.h>
+
+#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
+
+struct yt921x_mib_stats {
+	u64 rx_broadcast;
+	u64 rx_pause;
+	u64 rx_multicast;
+	u64 rx_crc_errors;
+
+	u64 rx_alignment_errors;
+	u64 rx_undersize_errors;
+	u64 rx_fragment_errors;
+	u64 rx_64byte;
+
+	u64 rx_65_127byte;
+	u64 rx_128_255byte;
+	u64 rx_256_511byte;
+	u64 rx_512_1023byte;
+
+	u64 rx_1024_1518byte;
+	u64 rx_jumbo;
+	u64 rx_good_bytes;
+
+	u64 rx_bad_bytes;
+	u64 rx_oversize_errors;
+
+	u64 rx_dropped;
+	u64 tx_broadcast;
+	u64 tx_pause;
+	u64 tx_multicast;
+
+	u64 tx_undersize_errors;
+	u64 tx_64byte;
+	u64 tx_65_127byte;
+	u64 tx_128_255byte;
+
+	u64 tx_256_511byte;
+	u64 tx_512_1023byte;
+	u64 tx_1024_1518byte;
+	u64 tx_jumbo;
+
+	u64 tx_good_bytes;
+	u64 tx_collisions;
+
+	u64 tx_aborted_errors;
+	u64 tx_multiple_collisions;
+	u64 tx_single_collisions;
+	u64 tx_good;
+
+	u64 tx_deferred;
+	u64 tx_late_collisions;
+	u64 rx_oam;
+	u64 tx_oam;
+};
+
+struct yt921x_mib {
+	struct yt921x_port *port;
+
+	struct delayed_work work;
+	struct yt921x_mib_stats stats;
+	u64 rx_frames;
+	u64 tx_frames;
+};
+
+void yt921x_mib_poll(struct work_struct *work);
+void
+yt921x_dsa_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+		       uint8_t *data);
+void
+yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data);
+int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset);
+void
+yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
+			     struct ethtool_eth_mac_stats *mac_stats);
+void
+yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
+			      struct ethtool_eth_ctrl_stats *ctrl_stats);
+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);
+void
+yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
+		       struct rtnl_link_stats64 *stats);
+void
+yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
+			   struct ethtool_pause_stats *pause_stats);
+
+#endif
-- 
2.53.0

[PATCH net-next v4 5/7] net: dsa: motorcomm: Use u64_stats_t for MIB stats

[David Yang]

64-bit variables might not be atomic on 32-bit architectures, and could
lead to load/store tearing.

This is a verbatim change that replace every u64 statistics into
u64_stats_t. u64_stats_sync will be equipped in the next commit.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/mib.c | 152 ++++++++++++++++----------------
 drivers/net/dsa/motorcomm/mib.h | 104 +++++++++++-----------
 2 files changed, 131 insertions(+), 125 deletions(-)

diff --git a/drivers/net/dsa/motorcomm/mib.c b/drivers/net/dsa/motorcomm/mib.c
index c2f7d7f83cd9..69b9eb7e5208 100644
--- a/drivers/net/dsa/motorcomm/mib.c
+++ b/drivers/net/dsa/motorcomm/mib.c
@@ -92,22 +92,16 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 	struct device *dev = to_device(priv);
 	struct yt921x_mib *pm = pp->mib;
 	struct yt921x_mib_stats *mib;
+	u64 rx_frames;
+	u64 tx_frames;
 	int res = 0;
 
 	mib = &pm->stats;
 
-	/* Reading of yt921x_mib_stats 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];
+		u64_stats_t *valp = &((u64_stats_t *)mib)[i];
 		u32 val0;
 		u64 val;
 
@@ -116,7 +110,7 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 			break;
 
 		if (desc->size <= 1) {
-			u64 old_val = *valp;
+			u64 old_val = u64_stats_read(valp);
 
 			val = (old_val & ~(u64)U32_MAX) | val0;
 			if (val < old_val)
@@ -130,17 +124,25 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 			val = ((u64)val1 << 32) | val0;
 		}
 
-		WRITE_ONCE(*valp, val);
+		u64_stats_set(valp, val);
 	}
 
-	pm->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;
-	pm->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;
+	rx_frames = u64_stats_read(&mib->rx_64byte) +
+		    u64_stats_read(&mib->rx_65_127byte) +
+		    u64_stats_read(&mib->rx_128_255byte) +
+		    u64_stats_read(&mib->rx_256_511byte) +
+		    u64_stats_read(&mib->rx_512_1023byte) +
+		    u64_stats_read(&mib->rx_1024_1518byte) +
+		    u64_stats_read(&mib->rx_jumbo);
+	tx_frames = u64_stats_read(&mib->tx_64byte) +
+		    u64_stats_read(&mib->tx_65_127byte) +
+		    u64_stats_read(&mib->tx_128_255byte) +
+		    u64_stats_read(&mib->tx_256_511byte) +
+		    u64_stats_read(&mib->tx_512_1023byte) +
+		    u64_stats_read(&mib->tx_1024_1518byte) +
+		    u64_stats_read(&mib->tx_jumbo);
+	u64_stats_set(&pm->rx_frames, rx_frames);
+	u64_stats_set(&pm->tx_frames, tx_frames);
 
 	if (res)
 		dev_err(dev, "Failed to %s port %d: %i\n", "read stats for",
@@ -206,7 +208,7 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
 		if (!desc->name)
 			continue;
 
-		data[j] = ((u64 *)mib)[i];
+		data[j] = u64_stats_read(&((u64_stats_t *)mib)[i]);
 		j++;
 	}
 }
@@ -245,28 +247,28 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
 	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
-	mac_stats->FramesTransmittedOK = pm->tx_frames;
-	mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
-	mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
-	mac_stats->FramesReceivedOK = pm->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->FramesTransmittedOK = u64_stats_read(&pm->tx_frames);
+	mac_stats->SingleCollisionFrames = u64_stats_read(&mib->tx_single_collisions);
+	mac_stats->MultipleCollisionFrames = u64_stats_read(&mib->tx_multiple_collisions);
+	mac_stats->FramesReceivedOK = u64_stats_read(&pm->rx_frames);
+	mac_stats->FrameCheckSequenceErrors = u64_stats_read(&mib->rx_crc_errors);
+	mac_stats->AlignmentErrors = u64_stats_read(&mib->rx_alignment_errors);
+	mac_stats->OctetsTransmittedOK = u64_stats_read(&mib->tx_good_bytes);
+	mac_stats->FramesWithDeferredXmissions = u64_stats_read(&mib->tx_deferred);
+	mac_stats->LateCollisions = u64_stats_read(&mib->tx_late_collisions);
+	mac_stats->FramesAbortedDueToXSColls = u64_stats_read(&mib->tx_aborted_errors);
 	/* mac_stats->FramesLostDueToIntMACXmitError */
 	/* mac_stats->CarrierSenseErrors */
-	mac_stats->OctetsReceivedOK = mib->rx_good_bytes;
+	mac_stats->OctetsReceivedOK = u64_stats_read(&mib->rx_good_bytes);
 	/* mac_stats->FramesLostDueToIntMACRcvError */
-	mac_stats->MulticastFramesXmittedOK = mib->tx_multicast;
-	mac_stats->BroadcastFramesXmittedOK = mib->tx_broadcast;
+	mac_stats->MulticastFramesXmittedOK = u64_stats_read(&mib->tx_multicast);
+	mac_stats->BroadcastFramesXmittedOK = u64_stats_read(&mib->tx_broadcast);
 	/* mac_stats->FramesWithExcessiveDeferral */
-	mac_stats->MulticastFramesReceivedOK = mib->rx_multicast;
-	mac_stats->BroadcastFramesReceivedOK = mib->rx_broadcast;
+	mac_stats->MulticastFramesReceivedOK = u64_stats_read(&mib->rx_multicast);
+	mac_stats->BroadcastFramesReceivedOK = u64_stats_read(&mib->rx_broadcast);
 	/* mac_stats->InRangeLengthErrors */
 	/* mac_stats->OutOfRangeLengthField */
-	mac_stats->FrameTooLongErrors = mib->rx_oversize_errors;
+	mac_stats->FrameTooLongErrors = u64_stats_read(&mib->rx_oversize_errors);
 }
 
 void
@@ -286,8 +288,8 @@ yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
 	yt921x_mib_read(priv, port);
 	mutex_unlock(&priv->reg_lock);
 
-	ctrl_stats->MACControlFramesTransmitted = mib->tx_pause;
-	ctrl_stats->MACControlFramesReceived = mib->rx_pause;
+	ctrl_stats->MACControlFramesTransmitted = u64_stats_read(&mib->tx_pause);
+	ctrl_stats->MACControlFramesReceived = u64_stats_read(&mib->rx_pause);
 	/* ctrl_stats->UnsupportedOpcodesReceived */
 }
 
@@ -322,26 +324,26 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
 
 	*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->undersize_pkts = u64_stats_read(&mib->rx_undersize_errors);
+	rmon_stats->oversize_pkts = u64_stats_read(&mib->rx_oversize_errors);
+	rmon_stats->fragments = u64_stats_read(&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;
+	rmon_stats->hist[0] = u64_stats_read(&mib->rx_64byte);
+	rmon_stats->hist[1] = u64_stats_read(&mib->rx_65_127byte);
+	rmon_stats->hist[2] = u64_stats_read(&mib->rx_128_255byte);
+	rmon_stats->hist[3] = u64_stats_read(&mib->rx_256_511byte);
+	rmon_stats->hist[4] = u64_stats_read(&mib->rx_512_1023byte);
+	rmon_stats->hist[5] = u64_stats_read(&mib->rx_1024_1518byte);
+	rmon_stats->hist[6] = u64_stats_read(&mib->rx_jumbo);
+
+	rmon_stats->hist_tx[0] = u64_stats_read(&mib->tx_64byte);
+	rmon_stats->hist_tx[1] = u64_stats_read(&mib->tx_65_127byte);
+	rmon_stats->hist_tx[2] = u64_stats_read(&mib->tx_128_255byte);
+	rmon_stats->hist_tx[3] = u64_stats_read(&mib->tx_256_511byte);
+	rmon_stats->hist_tx[4] = u64_stats_read(&mib->tx_512_1023byte);
+	rmon_stats->hist_tx[5] = u64_stats_read(&mib->tx_1024_1518byte);
+	rmon_stats->hist_tx[6] = u64_stats_read(&mib->tx_jumbo);
 }
 
 void
@@ -357,32 +359,34 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
 		return;
 	mib = &pm->stats;
 
-	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_length_errors = u64_stats_read(&mib->rx_undersize_errors) +
+				  u64_stats_read(&mib->rx_fragment_errors);
+	stats->rx_over_errors = u64_stats_read(&mib->rx_oversize_errors);
+	stats->rx_crc_errors = u64_stats_read(&mib->rx_crc_errors);
+	stats->rx_frame_errors = u64_stats_read(&mib->rx_alignment_errors);
 	/* stats->rx_fifo_errors */
 	/* stats->rx_missed_errors */
 
-	stats->tx_aborted_errors = mib->tx_aborted_errors;
+	stats->tx_aborted_errors = u64_stats_read(&mib->tx_aborted_errors);
 	/* stats->tx_carrier_errors */
-	stats->tx_fifo_errors = mib->tx_undersize_errors;
+	stats->tx_fifo_errors = u64_stats_read(&mib->tx_undersize_errors);
 	/* stats->tx_heartbeat_errors */
-	stats->tx_window_errors = mib->tx_late_collisions;
-
-	stats->rx_packets = pm->rx_frames;
-	stats->tx_packets = pm->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->tx_window_errors = u64_stats_read(&mib->tx_late_collisions);
+
+	stats->rx_packets = u64_stats_read(&pm->rx_frames);
+	stats->tx_packets = u64_stats_read(&pm->tx_frames);
+	stats->rx_bytes = u64_stats_read(&mib->rx_good_bytes) -
+			  ETH_FCS_LEN * stats->rx_packets;
+	stats->tx_bytes = u64_stats_read(&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->rx_dropped = u64_stats_read(&mib->rx_dropped);
 	/* stats->tx_dropped */
-	stats->multicast = mib->rx_multicast;
-	stats->collisions = mib->tx_collisions;
+	stats->multicast = u64_stats_read(&mib->rx_multicast);
+	stats->collisions = u64_stats_read(&mib->tx_collisions);
 }
 
 void
@@ -402,6 +406,6 @@ yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
 	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;
+	pause_stats->tx_pause_frames = u64_stats_read(&mib->tx_pause);
+	pause_stats->rx_pause_frames = u64_stats_read(&mib->rx_pause);
 }
diff --git a/drivers/net/dsa/motorcomm/mib.h b/drivers/net/dsa/motorcomm/mib.h
index cfad0665baae..d84ae2f449ac 100644
--- a/drivers/net/dsa/motorcomm/mib.h
+++ b/drivers/net/dsa/motorcomm/mib.h
@@ -6,6 +6,8 @@
 #ifndef _YT_MIB_H
 #define _YT_MIB_H
 
+#include <linux/u64_stats_sync.h>
+
 #include <net/dsa.h>
 
 #define YT921X_MIB_CTRL			0xc0004
@@ -72,55 +74,55 @@
 #define  YT921X_MIB_DATA_TX_OAM			0xac
 
 struct yt921x_mib_stats {
-	u64 rx_broadcast;
-	u64 rx_pause;
-	u64 rx_multicast;
-	u64 rx_crc_errors;
-
-	u64 rx_alignment_errors;
-	u64 rx_undersize_errors;
-	u64 rx_fragment_errors;
-	u64 rx_64byte;
-
-	u64 rx_65_127byte;
-	u64 rx_128_255byte;
-	u64 rx_256_511byte;
-	u64 rx_512_1023byte;
-
-	u64 rx_1024_1518byte;
-	u64 rx_jumbo;
-	u64 rx_good_bytes;
-
-	u64 rx_bad_bytes;
-	u64 rx_oversize_errors;
-
-	u64 rx_dropped;
-	u64 tx_broadcast;
-	u64 tx_pause;
-	u64 tx_multicast;
-
-	u64 tx_undersize_errors;
-	u64 tx_64byte;
-	u64 tx_65_127byte;
-	u64 tx_128_255byte;
-
-	u64 tx_256_511byte;
-	u64 tx_512_1023byte;
-	u64 tx_1024_1518byte;
-	u64 tx_jumbo;
-
-	u64 tx_good_bytes;
-	u64 tx_collisions;
-
-	u64 tx_aborted_errors;
-	u64 tx_multiple_collisions;
-	u64 tx_single_collisions;
-	u64 tx_good;
-
-	u64 tx_deferred;
-	u64 tx_late_collisions;
-	u64 rx_oam;
-	u64 tx_oam;
+	u64_stats_t rx_broadcast;
+	u64_stats_t rx_pause;
+	u64_stats_t rx_multicast;
+	u64_stats_t rx_crc_errors;
+
+	u64_stats_t rx_alignment_errors;
+	u64_stats_t rx_undersize_errors;
+	u64_stats_t rx_fragment_errors;
+	u64_stats_t rx_64byte;
+
+	u64_stats_t rx_65_127byte;
+	u64_stats_t rx_128_255byte;
+	u64_stats_t rx_256_511byte;
+	u64_stats_t rx_512_1023byte;
+
+	u64_stats_t rx_1024_1518byte;
+	u64_stats_t rx_jumbo;
+	u64_stats_t rx_good_bytes;
+
+	u64_stats_t rx_bad_bytes;
+	u64_stats_t rx_oversize_errors;
+
+	u64_stats_t rx_dropped;
+	u64_stats_t tx_broadcast;
+	u64_stats_t tx_pause;
+	u64_stats_t tx_multicast;
+
+	u64_stats_t tx_undersize_errors;
+	u64_stats_t tx_64byte;
+	u64_stats_t tx_65_127byte;
+	u64_stats_t tx_128_255byte;
+
+	u64_stats_t tx_256_511byte;
+	u64_stats_t tx_512_1023byte;
+	u64_stats_t tx_1024_1518byte;
+	u64_stats_t tx_jumbo;
+
+	u64_stats_t tx_good_bytes;
+	u64_stats_t tx_collisions;
+
+	u64_stats_t tx_aborted_errors;
+	u64_stats_t tx_multiple_collisions;
+	u64_stats_t tx_single_collisions;
+	u64_stats_t tx_good;
+
+	u64_stats_t tx_deferred;
+	u64_stats_t tx_late_collisions;
+	u64_stats_t rx_oam;
+	u64_stats_t tx_oam;
 };
 
 struct yt921x_mib {
@@ -128,8 +130,8 @@ struct yt921x_mib {
 
 	struct delayed_work work;
 	struct yt921x_mib_stats stats;
-	u64 rx_frames;
-	u64 tx_frames;
+	u64_stats_t rx_frames;
+	u64_stats_t tx_frames;
 };
 
 void yt921x_mib_poll(struct work_struct *work);
-- 
2.53.0

[PATCH net-next v4 6/7] net: dsa: motorcomm: Fix MIB synchronization

[David Yang]

The previous MIB sync was based on the false assumption that 64-bit
variables are always atomic. To fix that:

  * .get_stats64() uses u64_stats_sync, together with u64_stats_t;
  * others take the free mutex lock if possible.

To minimize time of the write side of u64_stats_sync, a per-port buffer
is used so that all the stat can be written back altogether after IO
operations.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/chip.c |  2 +
 drivers/net/dsa/motorcomm/mib.c  | 93 ++++++++++++++++++++------------
 drivers/net/dsa/motorcomm/mib.h  |  6 +++
 3 files changed, 66 insertions(+), 35 deletions(-)

diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index 34dbbdcea135..292a43f5d442 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -19,6 +19,7 @@
 #include <linux/of_mdio.h>
 #include <linux/of_net.h>
 #include <linux/sort.h>
+#include <linux/u64_stats_sync.h>
 
 #include <net/dsa.h>
 #include <net/dscp.h>
@@ -3783,6 +3784,7 @@ static int yt921x_dsa_port_setup(struct dsa_switch *ds, int port)
 		pp->mib = pm;
 
 		pm->port = pp;
+		u64_stats_init(&pm->syncp);
 		INIT_DELAYED_WORK(&pm->work, yt921x_mib_poll);
 	}
 
diff --git a/drivers/net/dsa/motorcomm/mib.c b/drivers/net/dsa/motorcomm/mib.c
index 69b9eb7e5208..f5197c1d2d7f 100644
--- a/drivers/net/dsa/motorcomm/mib.c
+++ b/drivers/net/dsa/motorcomm/mib.c
@@ -74,6 +74,8 @@ static const struct yt921x_mib_desc yt921x_mib_descs[] = {
 	MIB_DESC(1, YT921X_MIB_DATA_TX_OAM, "TxOAM"),
 };
 
+static_assert(ARRAY_SIZE(yt921x_mib_descs) == YT921X_MIB_STAT_NUM);
+
 /* The interval should be small enough to avoid overflow of 32bit MIBs.
  *
  * Until we can read MIBs from stats64 call directly (i.e. sleep
@@ -92,6 +94,8 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 	struct device *dev = to_device(priv);
 	struct yt921x_mib *pm = pp->mib;
 	struct yt921x_mib_stats *mib;
+	u64 *buf = pm->data;
+	unsigned long flags;
 	u64 rx_frames;
 	u64 tx_frames;
 	int res = 0;
@@ -101,7 +105,6 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 	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_stats_t *valp = &((u64_stats_t *)mib)[i];
 		u32 val0;
 		u64 val;
 
@@ -110,7 +113,7 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 			break;
 
 		if (desc->size <= 1) {
-			u64 old_val = u64_stats_read(valp);
+			u64 old_val = buf[i];
 
 			val = (old_val & ~(u64)U32_MAX) | val0;
 			if (val < old_val)
@@ -124,9 +127,12 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 			val = ((u64)val1 << 32) | val0;
 		}
 
-		u64_stats_set(valp, val);
+		buf[i] = val;
 	}
 
+	flags = u64_stats_update_begin_irqsave(&pm->syncp);
+	for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++)
+		u64_stats_set(&((u64_stats_t *)mib)[i], buf[i]);
 	rx_frames = u64_stats_read(&mib->rx_64byte) +
 		    u64_stats_read(&mib->rx_65_127byte) +
 		    u64_stats_read(&mib->rx_128_255byte) +
@@ -143,6 +149,7 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 		    u64_stats_read(&mib->tx_jumbo);
 	u64_stats_set(&pm->rx_frames, rx_frames);
 	u64_stats_set(&pm->tx_frames, tx_frames);
+	u64_stats_update_end_irqrestore(&pm->syncp, flags);
 
 	if (res)
 		dev_err(dev, "Failed to %s port %d: %i\n", "read stats for",
@@ -190,16 +197,16 @@ 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 *pm = pp->mib;
-	struct yt921x_mib_stats *mib;
+	u64 *buf;
 	size_t j;
 
 	if (!pm)
 		return;
-	mib = &pm->stats;
+	buf = pm->data;
 
 	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++) {
@@ -208,9 +215,11 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
 		if (!desc->name)
 			continue;
 
-		data[j] = u64_stats_read(&((u64_stats_t *)mib)[i]);
+		data[j] = buf[i];
 		j++;
 	}
+
+	mutex_unlock(&priv->reg_lock);
 }
 
 int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset)
@@ -244,8 +253,8 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
 	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
+
 	yt921x_mib_read(priv, port);
-	mutex_unlock(&priv->reg_lock);
 
 	mac_stats->FramesTransmittedOK = u64_stats_read(&pm->tx_frames);
 	mac_stats->SingleCollisionFrames = u64_stats_read(&mib->tx_single_collisions);
@@ -269,6 +278,8 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
 	/* mac_stats->InRangeLengthErrors */
 	/* mac_stats->OutOfRangeLengthField */
 	mac_stats->FrameTooLongErrors = u64_stats_read(&mib->rx_oversize_errors);
+
+	mutex_unlock(&priv->reg_lock);
 }
 
 void
@@ -285,12 +296,14 @@ yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
 	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
+
 	yt921x_mib_read(priv, port);
-	mutex_unlock(&priv->reg_lock);
 
 	ctrl_stats->MACControlFramesTransmitted = u64_stats_read(&mib->tx_pause);
 	ctrl_stats->MACControlFramesReceived = u64_stats_read(&mib->rx_pause);
 	/* ctrl_stats->UnsupportedOpcodesReceived */
+
+	mutex_unlock(&priv->reg_lock);
 }
 
 static const struct ethtool_rmon_hist_range yt921x_rmon_ranges[] = {
@@ -319,8 +332,8 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
 	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
+
 	yt921x_mib_read(priv, port);
-	mutex_unlock(&priv->reg_lock);
 
 	*ranges = yt921x_rmon_ranges;
 
@@ -344,6 +357,8 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
 	rmon_stats->hist_tx[4] = u64_stats_read(&mib->tx_512_1023byte);
 	rmon_stats->hist_tx[5] = u64_stats_read(&mib->tx_1024_1518byte);
 	rmon_stats->hist_tx[6] = u64_stats_read(&mib->tx_jumbo);
+
+	mutex_unlock(&priv->reg_lock);
 }
 
 void
@@ -354,39 +369,45 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
 	struct yt921x_port *pp = &priv->ports[port];
 	struct yt921x_mib *pm = pp->mib;
 	struct yt921x_mib_stats *mib;
+	unsigned int start;
 
 	if (!pm)
 		return;
 	mib = &pm->stats;
 
-	stats->rx_length_errors = u64_stats_read(&mib->rx_undersize_errors) +
-				  u64_stats_read(&mib->rx_fragment_errors);
-	stats->rx_over_errors = u64_stats_read(&mib->rx_oversize_errors);
-	stats->rx_crc_errors = u64_stats_read(&mib->rx_crc_errors);
-	stats->rx_frame_errors = u64_stats_read(&mib->rx_alignment_errors);
-	/* stats->rx_fifo_errors */
-	/* stats->rx_missed_errors */
-
-	stats->tx_aborted_errors = u64_stats_read(&mib->tx_aborted_errors);
-	/* stats->tx_carrier_errors */
-	stats->tx_fifo_errors = u64_stats_read(&mib->tx_undersize_errors);
-	/* stats->tx_heartbeat_errors */
-	stats->tx_window_errors = u64_stats_read(&mib->tx_late_collisions);
-
-	stats->rx_packets = u64_stats_read(&pm->rx_frames);
-	stats->tx_packets = u64_stats_read(&pm->tx_frames);
-	stats->rx_bytes = u64_stats_read(&mib->rx_good_bytes) -
-			  ETH_FCS_LEN * stats->rx_packets;
-	stats->tx_bytes = u64_stats_read(&mib->tx_good_bytes) -
-			  ETH_FCS_LEN * stats->tx_packets;
+	do {
+		start = u64_stats_fetch_begin(&pm->syncp);
+
+		stats->rx_length_errors = u64_stats_read(&mib->rx_undersize_errors) +
+					  u64_stats_read(&mib->rx_fragment_errors);
+		stats->rx_over_errors = u64_stats_read(&mib->rx_oversize_errors);
+		stats->rx_crc_errors = u64_stats_read(&mib->rx_crc_errors);
+		stats->rx_frame_errors = u64_stats_read(&mib->rx_alignment_errors);
+		/* stats->rx_fifo_errors */
+		/* stats->rx_missed_errors */
+
+		stats->tx_aborted_errors = u64_stats_read(&mib->tx_aborted_errors);
+		/* stats->tx_carrier_errors */
+		stats->tx_fifo_errors = u64_stats_read(&mib->tx_undersize_errors);
+		/* stats->tx_heartbeat_errors */
+		stats->tx_window_errors = u64_stats_read(&mib->tx_late_collisions);
+
+		stats->rx_packets = u64_stats_read(&pm->rx_frames);
+		stats->tx_packets = u64_stats_read(&pm->tx_frames);
+		stats->rx_bytes = u64_stats_read(&mib->rx_good_bytes) -
+				  ETH_FCS_LEN * stats->rx_packets;
+		stats->tx_bytes = u64_stats_read(&mib->tx_good_bytes) -
+				  ETH_FCS_LEN * stats->tx_packets;
+		stats->rx_dropped = u64_stats_read(&mib->rx_dropped);
+		/* stats->tx_dropped */
+		stats->multicast = u64_stats_read(&mib->rx_multicast);
+		stats->collisions = u64_stats_read(&mib->tx_collisions);
+	} while (u64_stats_fetch_retry(&pm->syncp, start));
+
 	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 = u64_stats_read(&mib->rx_dropped);
-	/* stats->tx_dropped */
-	stats->multicast = u64_stats_read(&mib->rx_multicast);
-	stats->collisions = u64_stats_read(&mib->tx_collisions);
 }
 
 void
@@ -403,9 +424,11 @@ yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
 	mib = &pm->stats;
 
 	mutex_lock(&priv->reg_lock);
+
 	yt921x_mib_read(priv, port);
-	mutex_unlock(&priv->reg_lock);
 
 	pause_stats->tx_pause_frames = u64_stats_read(&mib->tx_pause);
 	pause_stats->rx_pause_frames = u64_stats_read(&mib->rx_pause);
+
+	mutex_unlock(&priv->reg_lock);
 }
diff --git a/drivers/net/dsa/motorcomm/mib.h b/drivers/net/dsa/motorcomm/mib.h
index d84ae2f449ac..55719c29992b 100644
--- a/drivers/net/dsa/motorcomm/mib.h
+++ b/drivers/net/dsa/motorcomm/mib.h
@@ -125,13 +125,19 @@ struct yt921x_mib_stats {
 	u64_stats_t tx_oam;
 };
 
+#define YT921X_MIB_STAT_NUM	(sizeof(struct yt921x_mib_stats) / sizeof(u64_stats_t))
+
 struct yt921x_mib {
 	struct yt921x_port *port;
 
 	struct delayed_work work;
+	struct u64_stats_sync syncp;
+	/* protected by syncp OR priv->reg_lock */
 	struct yt921x_mib_stats stats;
 	u64_stats_t rx_frames;
 	u64_stats_t tx_frames;
+	/* protected by priv->reg_lock */
+	u64 data[YT921X_MIB_STAT_NUM];
 };
 
 void yt921x_mib_poll(struct work_struct *work);
-- 
2.53.0

[PATCH net-next v4 7/7] net: dsa: motorcomm: Use safe 64-bit counter reader

[David Yang]

64-bit counter registers are read as two separate 32-bit transactions.
If the low word wraps from about 0xffffffff to a small value while the
high word increments between the two transactions, the recombined value
becomes ((new_high << 32) | old_low), producing a spurious ~4 GiB jump.

Use a safe counter reader for this.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/mib.c | 21 +++++++++------------
 drivers/net/dsa/motorcomm/smi.c | 30 ++++++++++++++++++++++++++++++
 drivers/net/dsa/motorcomm/smi.h |  2 ++
 3 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/net/dsa/motorcomm/mib.c b/drivers/net/dsa/motorcomm/mib.c
index f5197c1d2d7f..2786d9ec2932 100644
--- a/drivers/net/dsa/motorcomm/mib.c
+++ b/drivers/net/dsa/motorcomm/mib.c
@@ -105,29 +105,26 @@ static int yt921x_mib_read(struct yt921x_priv *priv, int port)
 	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;
-		u32 val0;
-		u64 val;
-
-		res = yt921x_reg_read(priv, reg, &val0);
-		if (res)
-			break;
 
 		if (desc->size <= 1) {
 			u64 old_val = buf[i];
+			u32 val0;
+			u64 val;
+
+			res = yt921x_reg_read(priv, reg, &val0);
+			if (res)
+				break;
 
 			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);
+			buf[i] = val;
+		} else {
+			res = yt921x_counter_read(priv, reg, &buf[i]);
 			if (res)
 				break;
-			val = ((u64)val1 << 32) | val0;
 		}
-
-		buf[i] = val;
 	}
 
 	flags = u64_stats_update_begin_irqsave(&pm->syncp);
diff --git a/drivers/net/dsa/motorcomm/smi.c b/drivers/net/dsa/motorcomm/smi.c
index bf3adfd64165..27086602997b 100644
--- a/drivers/net/dsa/motorcomm/smi.c
+++ b/drivers/net/dsa/motorcomm/smi.c
@@ -63,6 +63,36 @@ int yt921x_reg_update_bits(struct yt921x_priv *priv, u32 reg, u32 mask, u32 val)
 	return yt921x_reg_write(priv, reg, u);
 }
 
+/* Reliably read a 64bit counter */
+int yt921x_counter_read(struct yt921x_priv *priv, u32 reg, u64 *valp)
+{
+	u32 old_lo;
+	int res;
+	u32 hi;
+	u32 lo;
+
+	res = yt921x_reg_read(priv, reg, &old_lo);
+	if (res)
+		return res;
+
+	for (int i = 0; i < 16; i++) {
+		res = yt921x_reg_read(priv, reg + 4, &hi);
+		if (res)
+			return res;
+		res = yt921x_reg_read(priv, reg, &lo);
+		if (res)
+			return res;
+
+		if (lo >= old_lo) {
+			*valp = ((u64)hi << 32) | lo;
+			return 0;
+		}
+		old_lo = lo;
+	}
+
+	return -ETIMEDOUT;
+}
+
 static int
 yt921x_regs_read(struct yt921x_priv *priv, u32 reg, u32 *vals,
 		 unsigned int num_regs)
diff --git a/drivers/net/dsa/motorcomm/smi.h b/drivers/net/dsa/motorcomm/smi.h
index 212e20f71d80..d34240548af7 100644
--- a/drivers/net/dsa/motorcomm/smi.h
+++ b/drivers/net/dsa/motorcomm/smi.h
@@ -35,6 +35,8 @@ yt921x_reg_toggle_bits(struct yt921x_priv *priv, u32 reg, u32 mask, bool set)
 	return yt921x_reg_update_bits(priv, reg, mask, !set ? 0 : mask);
 }
 
+int yt921x_counter_read(struct yt921x_priv *priv, u32 reg, u64 *valp);
+
 /* Some multi-word registers, like VLANn_CTRL, should be treated as a single
  * long register. More specifically, writes to parts of its words won't become
  * visible, until the last word is written.
-- 
2.53.0