Merge branch 'dsa-microchip-ptp'

Arun Ramadoss says:

====================
net: dsa: microchip: add PTP support for KSZ9563/KSZ8563 and LAN937x

KSZ9563/KSZ8563 and  LAN937x switch are capable for supporting IEEE 1588 PTP
protocol.  LAN937x has the same PTP register set similar to KSZ9563, hence the
implementation has been made common for the KSZ switches.  KSZ9563 does not
support two step timestamping but LAN937x supports both.  Tested the 1step &
2step p2p timestamping in LAN937x and p2p1step timestamping in KSZ9563.

This patch series is based on the Christian Eggers PTP support for KSZ9563.
Applied the Christian patch and updated as per the latest refactoring of KSZ
series code. The features added on top are PTP packet Interrupt
implementation based on nested handler, LAN937x two step timestamping and
programmable per_out pins.

Link: https://www.spinics.net/lists/netdev/msg705531.html

Patch v7 -> v8
- set skb->ip_summed = CHECKSUM_NONE after updating the checksum

Patch v6 -> v7
- Corrected the misplaced spaces and tabs
- Added mutex lock in do_aux_work
- Replaced 0/1 with false/true for ts_en
- SKB_TX_INPROGRESS flag is set before dsa_enqueue_skb
- Removed the fallthrough keyword
- pdelay_resp header correction is performed based on
  KSZ_SKB_CB(skb)->update_correction instead of clone

Patch v5 -> v6
- Rebased to latest net-next and renamed from RFC to patch net-next.

Patch v4 -> v5
- Replaced irq_domain_add_simple with irq_doamin_add_linear
- Used the helper diff_by_scaled_ppm() for adjfine.

Patch v3 -> v4
- removed IRQF_TRIGGER_FALLING from the request_threaded_irq of ptp msg
- addressed review comments on patch 10 periodic output
- added sign off in patch 6 & 9
- reverted to set PTP_1STEP bit for lan937x which is missed during v3 regression

Patch v2-> v3
- used port_rxtstamp for reconstructing the absolute timestamp instead of
tagger function pointer.
- Reverted to setting of 802.1As bit.

Patch v1 -> v2
- GPIO perout enable bit is different for LAN937x and KSZ9x. Added new patch
for configuring LAN937x programmable pins.
- PTP enabled in hardware based on both tx and rx timestamping of all the user
ports.
- Replaced setting of 802.1AS bit with P2P bit in PTP_MSG_CONF1 register.

RFC v2 -> Patch v1
- Changed the patch author based on past patch submission
- Changed the commit message prefix as net: dsa: microchip: ptp
Individual patch changes are listed in correspondig commits.

RFC v1 -> v2
- Added the p2p1step timestamping and conditional execution of 2 step for
  LAN937x only.
- Added the periodic output support
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 185 insertions, 16 deletions

diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 080e5c369f5b..694478fe07d6 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -4,8 +4,10 @@
  * 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"
@@ -16,9 +18,71 @@
 #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)
@@ -92,17 +156,20 @@ DSA_TAG_DRIVER(ksz8795_netdev_ops);
 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
 
 /*
- * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS.
+ * For Ingress (Host -> KSZ9477), 2/6 bytes are added before FCS.
  * ---------------------------------------------------------------------------
- * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
+ * 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 byte is added before FCS.
+ * For Egress (KSZ9477 -> Host), 1/5 bytes is added before FCS.
  * ---------------------------------------------------------------------------
- * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
+ * 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)
  */
@@ -114,6 +181,91 @@ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
 #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_slave_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)
 {
@@ -126,6 +278,8 @@ static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
 		return NULL;
 
 	/* Tag encoding */
+	ksz_xmit_timestamp(dp, skb);
+
 	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
 	addr = skb_mac_header(skb);
 
@@ -136,7 +290,7 @@ static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
 
 	*tag = cpu_to_be16(val);
 
-	return skb;
+	return ksz_defer_xmit(dp, skb);
 }
 
 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
@@ -147,8 +301,10 @@ static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
 	unsigned int len = KSZ_EGRESS_TAG_LEN;
 
 	/* Extra 4-bytes PTP timestamp */
-	if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
-		len += KSZ9477_PTP_TAG_LEN;
+	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);
 }
@@ -158,7 +314,9 @@ static const struct dsa_device_ops ksz9477_netdev_ops = {
 	.proto	= DSA_TAG_PROTO_KSZ9477,
 	.xmit	= ksz9477_xmit,
 	.rcv	= ksz9477_rcv,
-	.needed_tailroom = KSZ9477_INGRESS_TAG_LEN,
+	.connect = ksz_connect,
+	.disconnect = ksz_disconnect,
+	.needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 };
 
 DSA_TAG_DRIVER(ksz9477_netdev_ops);
@@ -178,6 +336,8 @@ static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
 		return NULL;
 
 	/* Tag encoding */
+	ksz_xmit_timestamp(dp, skb);
+
 	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 	addr = skb_mac_header(skb);
 
@@ -186,7 +346,7 @@ static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
 	if (is_link_local_ether_addr(addr))
 		*tag |= KSZ9893_TAIL_TAG_OVERRIDE;
 
-	return skb;
+	return ksz_defer_xmit(dp, skb);
 }
 
 static const struct dsa_device_ops ksz9893_netdev_ops = {
@@ -194,23 +354,28 @@ static const struct dsa_device_ops ksz9893_netdev_ops = {
 	.proto	= DSA_TAG_PROTO_KSZ9893,
 	.xmit	= ksz9893_xmit,
 	.rcv	= ksz9477_rcv,
-	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
+	.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 bytes are added before FCS.
+/* For xmit, 2/6 bytes are added before FCS.
  * ---------------------------------------------------------------------------
- * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
+ * 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 byte is added before FCS.
+ * For rcv, 1/5 bytes is added before FCS.
  * ---------------------------------------------------------------------------
- * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
+ * 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)
  */
@@ -232,6 +397,8 @@ static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
 	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);
@@ -244,7 +411,7 @@ static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
 
 	put_unaligned_be16(val, tag);
 
-	return skb;
+	return ksz_defer_xmit(dp, skb);
 }
 
 static const struct dsa_device_ops lan937x_netdev_ops = {
@@ -252,7 +419,9 @@ static const struct dsa_device_ops lan937x_netdev_ops = {
 	.proto	= DSA_TAG_PROTO_LAN937X,
 	.xmit	= lan937x_xmit,
 	.rcv	= ksz9477_rcv,
-	.needed_tailroom = LAN937X_EGRESS_TAG_LEN,
+	.connect = ksz_connect,
+	.disconnect = ksz_disconnect,
+	.needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 };
 
 DSA_TAG_DRIVER(lan937x_netdev_ops);