[Patch net-next v1 03/12] net: dsa: microchip: ptp: add 4 bytes in tail tag when ptp enabled

Arun Ramadoss
2022-11-28T10:33:58Z

If PTP is enabled in the hardware, then 4 bytes are added in the tail
tag. When PTP is enabled and 4 bytes are not added then messages are
corrupted.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
---
Patch v1
- Patch is new
---
MAINTAINERS | 1 +
drivers/net/dsa/microchip/ksz_common.h | 1 -
drivers/net/dsa/microchip/ksz_ptp.c | 24 +++++--
include/linux/dsa/ksz_common.h | 23 ++++++
net/dsa/tag_ksz.c | 99 ++++++++++++++++++++++++--
5 files changed, 136 insertions(+), 12 deletions(-)
create mode 100644 include/linux/dsa/ksz_common.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 61fe86968111..721d2c5dfa46 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13515,6 +13515,7 @@ S: Maintained
F: Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
F: Documentation/devicetree/bindings/net/dsa/microchip,lan937x.yaml
F: drivers/net/dsa/microchip/*
+F: include/linux/dsa/ksz_common.h
F: include/linux/platform_data/microchip-ksz.h
F: net/dsa/tag_ksz.c

diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index cd20f39a565f..4c5b35a7883c 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -105,7 +105,6 @@ struct ksz_port {
u8 num;
#if IS_ENABLED(CONFIG_NET_DSA_MICROCHIP_KSZ_PTP)
u8 hwts_tx_en;
- bool hwts_rx_en;
#endif
};

diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index a41418c6adf6..184aa57a8489 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -3,6 +3,7 @@
* Copyright (C) 2022 Microchip Technology Inc.
*/

+#include <linux/dsa/ksz_common.h>
#include <linux/kernel.h>
#include <linux/ptp_classify.h>
#include <linux/ptp_clock_kernel.h>
@@ -19,6 +20,16 @@
#define KSZ_PTP_INC_NS 40 /* HW clock is incremented every 40 ns (by 40) */
#define KSZ_PTP_SUBNS_BITS 32

+static int ksz_ptp_enable_mode(struct ksz_device *dev, bool enable)
+{
+ u16 data = 0;
+
+ if (enable)
+ data = PTP_ENABLE;
+
+ return ksz_rmw16(dev, REG_PTP_MSG_CONF1, PTP_ENABLE, data);
+}
+
/* The function is return back the capability of timestamping feature when
* requested through ethtool -T <interface> utility
*/
@@ -47,6 +58,7 @@ int ksz_get_ts_info(struct dsa_switch *ds, int port, struct ethtool_ts_info *ts)

int ksz_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr)
{
+ struct ksz_tagger_data *tagger_data = ksz_tagger_data(ds);
struct ksz_device *dev = ds->priv;
struct hwtstamp_config config;

@@ -54,7 +66,7 @@ int ksz_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr)

config.tx_type = dev->ports[port].hwts_tx_en;

- if (dev->ports[port].hwts_rx_en)
+ if (tagger_data->hwtstamp_get_state(ds))
config.rx_filter = HWTSTAMP_FILTER_ALL;
else
config.rx_filter = HWTSTAMP_FILTER_NONE;
@@ -66,7 +78,9 @@ int ksz_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr)
static int ksz_set_hwtstamp_config(struct ksz_device *dev, int port,
struct hwtstamp_config *config)
{
+ struct ksz_tagger_data *tagger_data = ksz_tagger_data(dev->ds);
struct ksz_port *prt = &dev->ports[port];
+ bool rx_on;

if (config->flags)
return -EINVAL;
@@ -82,14 +96,16 @@ static int ksz_set_hwtstamp_config(struct ksz_device *dev, int port,

switch (config->rx_filter) {
case HWTSTAMP_FILTER_NONE:
- prt->hwts_rx_en = false;
+ rx_on = false;
break;
default:
- prt->hwts_rx_en = true;
+ rx_on = true;
break;
}

- return 0;
+ tagger_data->hwtstamp_set_state(dev->ds, rx_on);
+
+ return ksz_ptp_enable_mode(dev, rx_on);
}

int ksz_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr)
diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h
new file mode 100644
index 000000000000..62996860b887
--- /dev/null
+++ b/include/linux/dsa/ksz_common.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip switch tag common header
+ *
+ * Copyright (C) 2022 Microchip Technology Inc.
+ */
+
+#ifndef _NET_DSA_KSZ_COMMON_H_
+#define _NET_DSA_KSZ_COMMON_H_
+
+#include <net/dsa.h>
+
+struct ksz_tagger_data {
+ bool (*hwtstamp_get_state)(struct dsa_switch *ds);
+ void (*hwtstamp_set_state)(struct dsa_switch *ds, bool on);
+};
+
+static inline struct ksz_tagger_data *
+ksz_tagger_data(struct dsa_switch *ds)
+{
+ return ds->tagger_data;
+}
+
+#endif /* _NET_DSA_KSZ_COMMON_H_ */
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 0f6ae143afc9..828af38f0598 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -4,6 +4,7 @@
* Copyright (c) 2017 Microchip Technology
*/

+#include <linux/dsa/ksz_common.h>
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <net/dsa.h>
@@ -16,9 +17,66 @@
#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;
+};
+
+static struct ksz_tagger_private *
+ksz_tagger_private(struct dsa_switch *ds)
+{
+ return ds->tagger_data;
+}
+
+static bool ksz_hwtstamp_get_state(struct dsa_switch *ds)
+{
+ struct ksz_tagger_private *priv = ksz_tagger_private(ds);
+
+ return test_bit(KSZ_HWTS_EN, &priv->state);
+}
+
+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;
+
+ kfree(priv);
+ ds->tagger_data = NULL;
+}
+
+static int ksz_connect(struct dsa_switch *ds)
+{
+ struct ksz_tagger_data *tagger_data;
+ struct ksz_tagger_private *priv;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ /* Export functions for switch driver use */
+ tagger_data = &priv->data;
+ tagger_data->hwtstamp_get_state = ksz_hwtstamp_get_state;
+ 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)
@@ -91,10 +149,11 @@ 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)
*
@@ -113,6 +172,19 @@ 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)

+/* Time stamp tag is only inserted if PTP is enabled in hardware. */
+static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
+{
+ struct ksz_tagger_private *priv;
+
+ priv = ksz_tagger_private(dp->ds);
+
+ if (!test_bit(KSZ_HWTS_EN, &priv->state))
+ return;
+
+ put_unaligned_be32(0, skb_put(skb, KSZ_PTP_TAG_LEN));
+}
+
static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
struct net_device *dev)
{
@@ -125,6 +197,8 @@ 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);

@@ -157,7 +231,9 @@ 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);
@@ -177,6 +253,8 @@ 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);

@@ -193,16 +271,19 @@ 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)
*
@@ -231,6 +312,8 @@ 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);
@@ -251,7 +334,9 @@ 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);
--
2.36.1