net/dsa/tag_ksz.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
  * Copyright (c) 2017 Microchip Technology
  */

 #include <linux/dsa/ksz_common.h>
 #include <linux/etherdevice.h>
 #include <linux/list.h>
 #include <linux/ptp_classify.h>
 #include <net/dsa.h>

 #include "tag.h"

 #define KSZ8795_NAME "ksz8795"
 #define KSZ9477_NAME "ksz9477"
 #define KSZ9893_NAME "ksz9893"
 #define LAN937X_NAME "lan937x"

 /* Typically only one byte is used for tail tag. */
 #define KSZ_PTP_TAG_LEN			4
 #define KSZ_EGRESS_TAG_LEN		1
 #define KSZ_INGRESS_TAG_LEN		1

 #define KSZ_HWTS_EN  0

 struct ksz_tagger_private {
 	struct ksz_tagger_data data; /* Must be first */
 	unsigned long state;
 	struct kthread_worker *xmit_worker;
 };

 static struct ksz_tagger_private *
 ksz_tagger_private(struct dsa_switch *ds)
 {
 	return ds->tagger_data;
 }

 static void ksz_hwtstamp_set_state(struct dsa_switch *ds, bool on)
 {
 	struct ksz_tagger_private *priv = ksz_tagger_private(ds);

 	if (on)
 		set_bit(KSZ_HWTS_EN, &priv->state);
 	else
 		clear_bit(KSZ_HWTS_EN, &priv->state);
 }

 static void ksz_disconnect(struct dsa_switch *ds)
 {
 	struct ksz_tagger_private *priv = ds->tagger_data;

 	kthread_destroy_worker(priv->xmit_worker);
 	kfree(priv);
 	ds->tagger_data = NULL;
 }

 static int ksz_connect(struct dsa_switch *ds)
 {
 	struct ksz_tagger_data *tagger_data;
 	struct kthread_worker *xmit_worker;
 	struct ksz_tagger_private *priv;
 	int ret;

 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	xmit_worker = kthread_create_worker(0, "dsa%d:%d_xmit",
 					    ds->dst->index, ds->index);
 	if (IS_ERR(xmit_worker)) {
 		ret = PTR_ERR(xmit_worker);
 		kfree(priv);
 		return ret;
 	}

 	priv->xmit_worker = xmit_worker;
 	/* Export functions for switch driver use */
 	tagger_data = &priv->data;
 	tagger_data->hwtstamp_set_state = ksz_hwtstamp_set_state;
 	ds->tagger_data = priv;

 	return 0;
 }

 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
 				      struct net_device *dev,
 				      unsigned int port, unsigned int len)
 {
 	skb->dev = dsa_conduit_find_user(dev, 0, port);
 	if (!skb->dev)
 		return NULL;

 	if (pskb_trim_rcsum(skb, skb->len - len))
 		return NULL;

 	dsa_default_offload_fwd_mark(skb);

 	return skb;
 }

 /*
  * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
  * ---------------------------------------------------------------------------
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
  * ---------------------------------------------------------------------------
  * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
  *
  * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
  * ---------------------------------------------------------------------------
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
  * ---------------------------------------------------------------------------
  * tag0 : zero-based value represents port
  *	  (eg, 0x0=port1, 0x2=port3, 0x3=port4)
  */

 #define KSZ8795_TAIL_TAG_EG_PORT_M	GENMASK(1, 0)
 #define KSZ8795_TAIL_TAG_OVERRIDE	BIT(6)
 #define KSZ8795_TAIL_TAG_LOOKUP		BIT(7)

 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct dsa_port *dp = dsa_user_to_port(dev);
 	struct ethhdr *hdr;
 	u8 *tag;

 	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 		return NULL;

 	/* Tag encoding */
 	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 	hdr = skb_eth_hdr(skb);

 	*tag = 1 << dp->index;
 	if (is_link_local_ether_addr(hdr->h_dest))
 		*tag |= KSZ8795_TAIL_TAG_OVERRIDE;

 	return skb;
 }

 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
 {
 	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;

 	return ksz_common_rcv(skb, dev, tag[0] & KSZ8795_TAIL_TAG_EG_PORT_M,
 			      KSZ_EGRESS_TAG_LEN);
 }

 static const struct dsa_device_ops ksz8795_netdev_ops = {
 	.name	= KSZ8795_NAME,
 	.proto	= DSA_TAG_PROTO_KSZ8795,
 	.xmit	= ksz8795_xmit,
 	.rcv	= ksz8795_rcv,
 	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
 };

 DSA_TAG_DRIVER(ksz8795_netdev_ops);
 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);

 /*
  * For Ingress (Host -> KSZ9477), 2/6 bytes are added before FCS.
  * ---------------------------------------------------------------------------
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
  * FCS(4bytes)
  * ---------------------------------------------------------------------------
  * ts   : time stamp (Present only if PTP is enabled in the Hardware)
  * tag0 : Prioritization (not used now)
  * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
  *
  * For Egress (KSZ9477 -> Host), 1/5 bytes is added before FCS.
  * ---------------------------------------------------------------------------
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
  * ---------------------------------------------------------------------------
  * ts   : time stamp (Present only if bit 7 of tag0 is set)
  * tag0 : zero-based value represents port
  *	  (eg, 0x00=port1, 0x02=port3, 0x06=port7)
  */

 #define KSZ9477_INGRESS_TAG_LEN		2
 #define KSZ9477_PTP_TAG_LEN		4
 #define KSZ9477_PTP_TAG_INDICATION	BIT(7)

 #define KSZ9477_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
 #define KSZ9477_TAIL_TAG_PRIO		GENMASK(8, 7)
 #define KSZ9477_TAIL_TAG_OVERRIDE	BIT(9)
 #define KSZ9477_TAIL_TAG_LOOKUP		BIT(10)

 static void ksz_rcv_timestamp(struct sk_buff *skb, u8 *tag)
 {
 	u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN;
 	ktime_t tstamp;

 	tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw));
 	KSZ_SKB_CB(skb)->tstamp = tstamp;
 }

 /* Time stamp tag *needs* to be inserted if PTP is enabled in hardware.
  * Regardless of Whether it is a PTP frame or not.
  */
 static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
 {
 	struct ksz_tagger_private *priv;
 	struct ptp_header *ptp_hdr;
 	unsigned int ptp_type;
 	u32 tstamp_raw = 0;
 	s64 correction;

 	priv = ksz_tagger_private(dp->ds);

 	if (!test_bit(KSZ_HWTS_EN, &priv->state))
 		return;

 	if (!KSZ_SKB_CB(skb)->update_correction)
 		goto output_tag;

 	ptp_type = KSZ_SKB_CB(skb)->ptp_type;

 	ptp_hdr = ptp_parse_header(skb, ptp_type);
 	if (!ptp_hdr)
 		goto output_tag;

 	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);

 	if (correction < 0) {
 		struct timespec64 ts;

 		ts = ns_to_timespec64(-correction >> 16);
 		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;

 		/* Set correction field to 0 and update UDP checksum */
 		ptp_header_update_correction(skb, ptp_type, ptp_hdr, 0);
 	}

 output_tag:
 	put_unaligned_be32(tstamp_raw, skb_put(skb, KSZ_PTP_TAG_LEN));
 }

 /* Defer transmit if waiting for egress time stamp is required.  */
 static struct sk_buff *ksz_defer_xmit(struct dsa_port *dp, struct sk_buff *skb)
 {
 	struct ksz_tagger_data *tagger_data = ksz_tagger_data(dp->ds);
 	struct ksz_tagger_private *priv = ksz_tagger_private(dp->ds);
 	void (*xmit_work_fn)(struct kthread_work *work);
 	struct sk_buff *clone = KSZ_SKB_CB(skb)->clone;
 	struct ksz_deferred_xmit_work *xmit_work;
 	struct kthread_worker *xmit_worker;

 	if (!clone)
 		return skb;  /* no deferred xmit for this packet */

 	xmit_work_fn = tagger_data->xmit_work_fn;
 	xmit_worker = priv->xmit_worker;

 	if (!xmit_work_fn || !xmit_worker)
 		return NULL;

 	xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
 	if (!xmit_work)
 		return NULL;

 	kthread_init_work(&xmit_work->work, xmit_work_fn);
 	/* Increase refcount so the kfree_skb in dsa_user_xmit
 	 * won't really free the packet.
 	 */
 	xmit_work->dp = dp;
 	xmit_work->skb = skb_get(skb);

 	kthread_queue_work(xmit_worker, &xmit_work->work);

 	return NULL;
 }

 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
 				    struct net_device *dev)
 {
 	u16 queue_mapping = skb_get_queue_mapping(skb);
 	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
 	struct dsa_port *dp = dsa_user_to_port(dev);
 	struct ethhdr *hdr;
 	__be16 *tag;
 	u16 val;

 	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 		return NULL;

 	/* Tag encoding */
 	ksz_xmit_timestamp(dp, skb);

 	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
 	hdr = skb_eth_hdr(skb);

 	val = BIT(dp->index);

 	val |= FIELD_PREP(KSZ9477_TAIL_TAG_PRIO, prio);

 	if (is_link_local_ether_addr(hdr->h_dest))
 		val |= KSZ9477_TAIL_TAG_OVERRIDE;

 	if (dev->features & NETIF_F_HW_HSR_DUP) {
 		struct net_device *hsr_dev = dp->hsr_dev;
 		struct dsa_port *other_dp;

 		dsa_hsr_foreach_port(other_dp, dp->ds, hsr_dev)
 			val |= BIT(other_dp->index);
 	}

 	*tag = cpu_to_be16(val);

 	return ksz_defer_xmit(dp, skb);
 }

 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
 {
 	/* Tag decoding */
 	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
 	unsigned int port = tag[0] & KSZ9477_TAIL_TAG_EG_PORT_M;
 	unsigned int len = KSZ_EGRESS_TAG_LEN;

 	/* Extra 4-bytes PTP timestamp */
 	if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
 		ksz_rcv_timestamp(skb, tag);
 		len += KSZ_PTP_TAG_LEN;
 	}

 	return ksz_common_rcv(skb, dev, port, len);
 }

 static const struct dsa_device_ops ksz9477_netdev_ops = {
 	.name	= KSZ9477_NAME,
 	.proto	= DSA_TAG_PROTO_KSZ9477,
 	.xmit	= ksz9477_xmit,
 	.rcv	= ksz9477_rcv,
 	.connect = ksz_connect,
 	.disconnect = ksz_disconnect,
 	.needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 };

 DSA_TAG_DRIVER(ksz9477_netdev_ops);
 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477, KSZ9477_NAME);

 #define KSZ9893_TAIL_TAG_PRIO		GENMASK(4, 3)
 #define KSZ9893_TAIL_TAG_OVERRIDE	BIT(5)
 #define KSZ9893_TAIL_TAG_LOOKUP		BIT(6)

 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
 				    struct net_device *dev)
 {
 	u16 queue_mapping = skb_get_queue_mapping(skb);
 	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
 	struct dsa_port *dp = dsa_user_to_port(dev);
 	struct ethhdr *hdr;
 	u8 *tag;

 	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 		return NULL;

 	/* Tag encoding */
 	ksz_xmit_timestamp(dp, skb);

 	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 	hdr = skb_eth_hdr(skb);

 	*tag = BIT(dp->index);

 	*tag |= FIELD_PREP(KSZ9893_TAIL_TAG_PRIO, prio);

 	if (is_link_local_ether_addr(hdr->h_dest))
 		*tag |= KSZ9893_TAIL_TAG_OVERRIDE;

 	return ksz_defer_xmit(dp, skb);
 }

 static const struct dsa_device_ops ksz9893_netdev_ops = {
 	.name	= KSZ9893_NAME,
 	.proto	= DSA_TAG_PROTO_KSZ9893,
 	.xmit	= ksz9893_xmit,
 	.rcv	= ksz9477_rcv,
 	.connect = ksz_connect,
 	.disconnect = ksz_disconnect,
 	.needed_tailroom = KSZ_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 };

 DSA_TAG_DRIVER(ksz9893_netdev_ops);
 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);

 /* For xmit, 2/6 bytes are added before FCS.
  * ---------------------------------------------------------------------------
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
  * FCS(4bytes)
  * ---------------------------------------------------------------------------
  * ts   : time stamp (Present only if PTP is enabled in the Hardware)
  * tag0 : represents tag override, lookup and valid
  * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
  *
  * For rcv, 1/5 bytes is added before FCS.
  * ---------------------------------------------------------------------------
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
  * ---------------------------------------------------------------------------
  * ts   : time stamp (Present only if bit 7 of tag0 is set)
  * tag0 : zero-based value represents port
  *	  (eg, 0x00=port1, 0x02=port3, 0x07=port8)
  */
 #define LAN937X_EGRESS_TAG_LEN		2

 #define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE	BIT(11)
 #define LAN937X_TAIL_TAG_LOOKUP			BIT(12)
 #define LAN937X_TAIL_TAG_VALID			BIT(13)
 #define LAN937X_TAIL_TAG_PRIO			GENMASK(10, 8)
 #define LAN937X_TAIL_TAG_PORT_MASK		7

 static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
 				    struct net_device *dev)
 {
 	u16 queue_mapping = skb_get_queue_mapping(skb);
 	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
 	struct dsa_port *dp = dsa_user_to_port(dev);
 	const struct ethhdr *hdr = eth_hdr(skb);
 	__be16 *tag;
 	u16 val;

 	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 		return NULL;

 	ksz_xmit_timestamp(dp, skb);

 	tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);

 	val = BIT(dp->index);

 	val |= FIELD_PREP(LAN937X_TAIL_TAG_PRIO, prio);

 	if (is_link_local_ether_addr(hdr->h_dest))
 		val |= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;

 	/* Tail tag valid bit - This bit should always be set by the CPU */
 	val |= LAN937X_TAIL_TAG_VALID;

 	put_unaligned_be16(val, tag);

 	return ksz_defer_xmit(dp, skb);
 }

 static const struct dsa_device_ops lan937x_netdev_ops = {
 	.name	= LAN937X_NAME,
 	.proto	= DSA_TAG_PROTO_LAN937X,
 	.xmit	= lan937x_xmit,
 	.rcv	= ksz9477_rcv,
 	.connect = ksz_connect,
 	.disconnect = ksz_disconnect,
 	.needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 };

 DSA_TAG_DRIVER(lan937x_netdev_ops);
 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);

 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
 	&DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
 	&DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
 	&DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
 	&DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
 };

 module_dsa_tag_drivers(dsa_tag_driver_array);

 MODULE_DESCRIPTION("DSA tag driver for Microchip 8795/937x/9477/9893 families of switches");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
	* Copyright (c) 2017 Microchip Technology
	*/

	#include <linux/dsa/ksz_common.h>
	#include <linux/etherdevice.h>
	#include <linux/list.h>
	#include <linux/ptp_classify.h>
	#include <net/dsa.h>

	#include "tag.h"

	#define KSZ8795_NAME "ksz8795"
	#define KSZ9477_NAME "ksz9477"
	#define KSZ9893_NAME "ksz9893"
	#define LAN937X_NAME "lan937x"

	/* Typically only one byte is used for tail tag. */
	#define KSZ_PTP_TAG_LEN 4
	#define KSZ_EGRESS_TAG_LEN 1
	#define KSZ_INGRESS_TAG_LEN 1

	#define KSZ_HWTS_EN 0

	struct ksz_tagger_private {
	struct ksz_tagger_data data; /* Must be first */
	unsigned long state;
	struct kthread_worker *xmit_worker;
	};

	static struct ksz_tagger_private *
	ksz_tagger_private(struct dsa_switch *ds)
	{
	return ds->tagger_data;
	}

	static void ksz_hwtstamp_set_state(struct dsa_switch *ds, bool on)
	{
	struct ksz_tagger_private *priv = ksz_tagger_private(ds);

	if (on)
	set_bit(KSZ_HWTS_EN, &priv->state);
	else
	clear_bit(KSZ_HWTS_EN, &priv->state);
	}

	static void ksz_disconnect(struct dsa_switch *ds)
	{
	struct ksz_tagger_private *priv = ds->tagger_data;

	kthread_destroy_worker(priv->xmit_worker);
	kfree(priv);
	ds->tagger_data = NULL;
	}

	static int ksz_connect(struct dsa_switch *ds)
	{
	struct ksz_tagger_data *tagger_data;
	struct kthread_worker *xmit_worker;
	struct ksz_tagger_private *priv;
	int ret;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	xmit_worker = kthread_create_worker(0, "dsa%d:%d_xmit",
	ds->dst->index, ds->index);
	if (IS_ERR(xmit_worker)) {
	ret = PTR_ERR(xmit_worker);
	kfree(priv);
	return ret;
	}

	priv->xmit_worker = xmit_worker;
	/* Export functions for switch driver use */
	tagger_data = &priv->data;
	tagger_data->hwtstamp_set_state = ksz_hwtstamp_set_state;
	ds->tagger_data = priv;

	return 0;
	}

	static struct sk_buff ksz_common_rcv(struct sk_buff skb,
	struct net_device *dev,
	unsigned int port, unsigned int len)
	{
	skb->dev = dsa_conduit_find_user(dev, 0, port);
	if (!skb->dev)
	return NULL;

	if (pskb_trim_rcsum(skb, skb->len - len))
	return NULL;

	dsa_default_offload_fwd_mark(skb);

	return skb;
	}

	/*
	* For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
	* ---------------------------------------------------------------------------
	* DA(6bytes)\|SA(6bytes)\|....\|Data(nbytes)\|tag(1byte)\|FCS(4bytes)
	* ---------------------------------------------------------------------------
	* tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
	*
	* For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
	* ---------------------------------------------------------------------------
	* DA(6bytes)\|SA(6bytes)\|....\|Data(nbytes)\|tag0(1byte)\|FCS(4bytes)
	* ---------------------------------------------------------------------------
	* tag0 : zero-based value represents port
	* (eg, 0x0=port1, 0x2=port3, 0x3=port4)
	*/

	#define KSZ8795_TAIL_TAG_EG_PORT_M GENMASK(1, 0)
	#define KSZ8795_TAIL_TAG_OVERRIDE BIT(6)
	#define KSZ8795_TAIL_TAG_LOOKUP BIT(7)

	static struct sk_buff ksz8795_xmit(struct sk_buff skb, struct net_device *dev)
	{
	struct dsa_port *dp = dsa_user_to_port(dev);
	struct ethhdr *hdr;
	u8 *tag;

	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
	return NULL;

	/* Tag encoding */
	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
	hdr = skb_eth_hdr(skb);

	*tag = 1 << dp->index;
	if (is_link_local_ether_addr(hdr->h_dest))
	*tag \|= KSZ8795_TAIL_TAG_OVERRIDE;

	return skb;
	}

	static struct sk_buff ksz8795_rcv(struct sk_buff skb, struct net_device *dev)
	{
	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;

	return ksz_common_rcv(skb, dev, tag[0] & KSZ8795_TAIL_TAG_EG_PORT_M,
	KSZ_EGRESS_TAG_LEN);
	}

	static const struct dsa_device_ops ksz8795_netdev_ops = {
	.name = KSZ8795_NAME,
	.proto = DSA_TAG_PROTO_KSZ8795,
	.xmit = ksz8795_xmit,
	.rcv = ksz8795_rcv,
	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
	};

	DSA_TAG_DRIVER(ksz8795_netdev_ops);
	MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);

	/*
	* For Ingress (Host -> KSZ9477), 2/6 bytes are added before FCS.
	* ---------------------------------------------------------------------------
	* DA(6bytes)\|SA(6bytes)\|....\|Data(nbytes)\|ts(4bytes)\|tag0(1byte)\|tag1(1byte)\|
	* FCS(4bytes)
	* ---------------------------------------------------------------------------
	* ts : time stamp (Present only if PTP is enabled in the Hardware)
	* tag0 : Prioritization (not used now)
	* tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
	*
	* For Egress (KSZ9477 -> Host), 1/5 bytes is added before FCS.
	* ---------------------------------------------------------------------------
	* DA(6bytes)\|SA(6bytes)\|....\|Data(nbytes)\|ts(4bytes)\|tag0(1byte)\|FCS(4bytes)
	* ---------------------------------------------------------------------------
	* ts : time stamp (Present only if bit 7 of tag0 is set)
	* tag0 : zero-based value represents port
	* (eg, 0x00=port1, 0x02=port3, 0x06=port7)
	*/

	#define KSZ9477_INGRESS_TAG_LEN 2
	#define KSZ9477_PTP_TAG_LEN 4
	#define KSZ9477_PTP_TAG_INDICATION BIT(7)

	#define KSZ9477_TAIL_TAG_EG_PORT_M GENMASK(2, 0)
	#define KSZ9477_TAIL_TAG_PRIO GENMASK(8, 7)
	#define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
	#define KSZ9477_TAIL_TAG_LOOKUP BIT(10)

	static void ksz_rcv_timestamp(struct sk_buff skb, u8 tag)
	{
	u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN;
	ktime_t tstamp;

	tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw));
	KSZ_SKB_CB(skb)->tstamp = tstamp;
	}

	/* Time stamp tag needs to be inserted if PTP is enabled in hardware.
	* Regardless of Whether it is a PTP frame or not.
	*/
	static void ksz_xmit_timestamp(struct dsa_port dp, struct sk_buff skb)
	{
	struct ksz_tagger_private *priv;
	struct ptp_header *ptp_hdr;
	unsigned int ptp_type;
	u32 tstamp_raw = 0;
	s64 correction;

	priv = ksz_tagger_private(dp->ds);

	if (!test_bit(KSZ_HWTS_EN, &priv->state))
	return;

	if (!KSZ_SKB_CB(skb)->update_correction)
	goto output_tag;

	ptp_type = KSZ_SKB_CB(skb)->ptp_type;

	ptp_hdr = ptp_parse_header(skb, ptp_type);
	if (!ptp_hdr)
	goto output_tag;

	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);

	if (correction < 0) {
	struct timespec64 ts;

	ts = ns_to_timespec64(-correction >> 16);
	tstamp_raw = ((ts.tv_sec & 3) << 30) \| ts.tv_nsec;

	/* Set correction field to 0 and update UDP checksum */
	ptp_header_update_correction(skb, ptp_type, ptp_hdr, 0);
	}

	output_tag:
	put_unaligned_be32(tstamp_raw, skb_put(skb, KSZ_PTP_TAG_LEN));
	}

	/* Defer transmit if waiting for egress time stamp is required. */
	static struct sk_buff ksz_defer_xmit(struct dsa_port dp, struct sk_buff *skb)
	{
	struct ksz_tagger_data *tagger_data = ksz_tagger_data(dp->ds);
	struct ksz_tagger_private *priv = ksz_tagger_private(dp->ds);
	void (xmit_work_fn)(struct kthread_work work);
	struct sk_buff *clone = KSZ_SKB_CB(skb)->clone;
	struct ksz_deferred_xmit_work *xmit_work;
	struct kthread_worker *xmit_worker;

	if (!clone)
	return skb; /* no deferred xmit for this packet */

	xmit_work_fn = tagger_data->xmit_work_fn;
	xmit_worker = priv->xmit_worker;

	if (!xmit_work_fn \|\| !xmit_worker)
	return NULL;

	xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
	if (!xmit_work)
	return NULL;

	kthread_init_work(&xmit_work->work, xmit_work_fn);
	/* Increase refcount so the kfree_skb in dsa_user_xmit
	* won't really free the packet.
	*/
	xmit_work->dp = dp;
	xmit_work->skb = skb_get(skb);

	kthread_queue_work(xmit_worker, &xmit_work->work);

	return NULL;
	}

	static struct sk_buff ksz9477_xmit(struct sk_buff skb,
	struct net_device *dev)
	{
	u16 queue_mapping = skb_get_queue_mapping(skb);
	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
	struct dsa_port *dp = dsa_user_to_port(dev);
	struct ethhdr *hdr;
	__be16 *tag;
	u16 val;

	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
	return NULL;

	/* Tag encoding */
	ksz_xmit_timestamp(dp, skb);

	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
	hdr = skb_eth_hdr(skb);

	val = BIT(dp->index);

	val \|= FIELD_PREP(KSZ9477_TAIL_TAG_PRIO, prio);

	if (is_link_local_ether_addr(hdr->h_dest))
	val \|= KSZ9477_TAIL_TAG_OVERRIDE;

	if (dev->features & NETIF_F_HW_HSR_DUP) {
	struct net_device *hsr_dev = dp->hsr_dev;
	struct dsa_port *other_dp;

	dsa_hsr_foreach_port(other_dp, dp->ds, hsr_dev)
	val \|= BIT(other_dp->index);
	}

	*tag = cpu_to_be16(val);

	return ksz_defer_xmit(dp, skb);
	}

	static struct sk_buff ksz9477_rcv(struct sk_buff skb, struct net_device *dev)
	{
	/* Tag decoding */
	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
	unsigned int port = tag[0] & KSZ9477_TAIL_TAG_EG_PORT_M;
	unsigned int len = KSZ_EGRESS_TAG_LEN;

	/* Extra 4-bytes PTP timestamp */
	if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
	ksz_rcv_timestamp(skb, tag);
	len += KSZ_PTP_TAG_LEN;
	}

	return ksz_common_rcv(skb, dev, port, len);
	}

	static const struct dsa_device_ops ksz9477_netdev_ops = {
	.name = KSZ9477_NAME,
	.proto = DSA_TAG_PROTO_KSZ9477,
	.xmit = ksz9477_xmit,
	.rcv = ksz9477_rcv,
	.connect = ksz_connect,
	.disconnect = ksz_disconnect,
	.needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
	};

	DSA_TAG_DRIVER(ksz9477_netdev_ops);
	MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477, KSZ9477_NAME);

	#define KSZ9893_TAIL_TAG_PRIO GENMASK(4, 3)
	#define KSZ9893_TAIL_TAG_OVERRIDE BIT(5)
	#define KSZ9893_TAIL_TAG_LOOKUP BIT(6)

	static struct sk_buff ksz9893_xmit(struct sk_buff skb,
	struct net_device *dev)
	{
	u16 queue_mapping = skb_get_queue_mapping(skb);
	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
	struct dsa_port *dp = dsa_user_to_port(dev);
	struct ethhdr *hdr;
	u8 *tag;

	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
	return NULL;

	/* Tag encoding */
	ksz_xmit_timestamp(dp, skb);

	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
	hdr = skb_eth_hdr(skb);

	*tag = BIT(dp->index);

	*tag \|= FIELD_PREP(KSZ9893_TAIL_TAG_PRIO, prio);

	if (is_link_local_ether_addr(hdr->h_dest))
	*tag \|= KSZ9893_TAIL_TAG_OVERRIDE;

	return ksz_defer_xmit(dp, skb);
	}

	static const struct dsa_device_ops ksz9893_netdev_ops = {
	.name = KSZ9893_NAME,
	.proto = DSA_TAG_PROTO_KSZ9893,
	.xmit = ksz9893_xmit,
	.rcv = ksz9477_rcv,
	.connect = ksz_connect,
	.disconnect = ksz_disconnect,
	.needed_tailroom = KSZ_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
	};

	DSA_TAG_DRIVER(ksz9893_netdev_ops);
	MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);

	/* For xmit, 2/6 bytes are added before FCS.
	* ---------------------------------------------------------------------------
	* DA(6bytes)\|SA(6bytes)\|....\|Data(nbytes)\|ts(4bytes)\|tag0(1byte)\|tag1(1byte)\|
	* FCS(4bytes)
	* ---------------------------------------------------------------------------
	* ts : time stamp (Present only if PTP is enabled in the Hardware)
	* tag0 : represents tag override, lookup and valid
	* tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
	*
	* For rcv, 1/5 bytes is added before FCS.
	* ---------------------------------------------------------------------------
	* DA(6bytes)\|SA(6bytes)\|....\|Data(nbytes)\|ts(4bytes)\|tag0(1byte)\|FCS(4bytes)
	* ---------------------------------------------------------------------------
	* ts : time stamp (Present only if bit 7 of tag0 is set)
	* tag0 : zero-based value represents port
	* (eg, 0x00=port1, 0x02=port3, 0x07=port8)
	*/
	#define LAN937X_EGRESS_TAG_LEN 2

	#define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE BIT(11)
	#define LAN937X_TAIL_TAG_LOOKUP BIT(12)
	#define LAN937X_TAIL_TAG_VALID BIT(13)
	#define LAN937X_TAIL_TAG_PRIO GENMASK(10, 8)
	#define LAN937X_TAIL_TAG_PORT_MASK 7

	static struct sk_buff lan937x_xmit(struct sk_buff skb,
	struct net_device *dev)
	{
	u16 queue_mapping = skb_get_queue_mapping(skb);
	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
	struct dsa_port *dp = dsa_user_to_port(dev);
	const struct ethhdr *hdr = eth_hdr(skb);
	__be16 *tag;
	u16 val;

	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
	return NULL;

	ksz_xmit_timestamp(dp, skb);

	tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);

	val = BIT(dp->index);

	val \|= FIELD_PREP(LAN937X_TAIL_TAG_PRIO, prio);

	if (is_link_local_ether_addr(hdr->h_dest))
	val \|= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;

	/* Tail tag valid bit - This bit should always be set by the CPU */
	val \|= LAN937X_TAIL_TAG_VALID;

	put_unaligned_be16(val, tag);

	return ksz_defer_xmit(dp, skb);
	}

	static const struct dsa_device_ops lan937x_netdev_ops = {
	.name = LAN937X_NAME,
	.proto = DSA_TAG_PROTO_LAN937X,
	.xmit = lan937x_xmit,
	.rcv = ksz9477_rcv,
	.connect = ksz_connect,
	.disconnect = ksz_disconnect,
	.needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
	};

	DSA_TAG_DRIVER(lan937x_netdev_ops);
	MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);

	static struct dsa_tag_driver *dsa_tag_driver_array[] = {
	&DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
	&DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
	&DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
	&DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
	};

	module_dsa_tag_drivers(dsa_tag_driver_array);

	MODULE_DESCRIPTION("DSA tag driver for Microchip 8795/937x/9477/9893 families of switches");
	MODULE_LICENSE("GPL");