[net-next 3/3] net: mscc: ocelot: support PTP Sync one-step timestamping

From: Yangbo Lu
Date: Fri Apr 16 2021 - 08:31:01 EST


Although HWTSTAMP_TX_ONESTEP_SYNC existed in ioctl for hardware timestamp
configuration, the PTP Sync one-step timestamping had never been supported.

This patch is to truely support it. The hardware timestamp request type is
stored in DSA_SKB_CB_PRIV first byte per skb, so that corresponding
configuration could be done during transmitting. Non-onestep-Sync packet
with one-step timestamp request should fall back to use two-step timestamp.

Signed-off-by: Yangbo Lu <yangbo.lu@xxxxxxx>
---
drivers/net/ethernet/mscc/ocelot.c | 57 ++++++++++++++++++++++++++
drivers/net/ethernet/mscc/ocelot_net.c | 5 +--
include/soc/mscc/ocelot.h | 1 +
net/dsa/tag_ocelot.c | 25 ++---------
net/dsa/tag_ocelot_8021q.c | 39 +++++-------------
5 files changed, 72 insertions(+), 55 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 541d3b4076be..69d36b6241ff 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -6,6 +6,7 @@
*/
#include <linux/dsa/ocelot.h>
#include <linux/if_bridge.h>
+#include <linux/ptp_classify.h>
#include <soc/mscc/ocelot_vcap.h>
#include "ocelot.h"
#include "ocelot_vcap.h"
@@ -546,6 +547,50 @@ static void ocelot_port_add_txtstamp_skb(struct ocelot *ocelot, int port,
spin_unlock(&ocelot_port->ts_id_lock);
}

+bool ocelot_ptp_rew_op(struct sk_buff *skb, struct sk_buff *clone, u32 *rew_op)
+{
+ /* For two-step timestamp, retrieve ptp_cmd in DSA_SKB_CB_PRIV
+ * and timestamp ID in clone->cb[0].
+ * For one-step timestamp, retrieve ptp_cmd in DSA_SKB_CB_PRIV.
+ */
+ u8 *ptp_cmd = DSA_SKB_CB_PRIV(skb);
+
+ if (clone) {
+ *rew_op = *ptp_cmd;
+ *rew_op |= clone->cb[0] << 3;
+ } else if (*ptp_cmd) {
+ *rew_op = *ptp_cmd;
+ } else {
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(ocelot_ptp_rew_op);
+
+static bool ocelot_ptp_is_onestep_sync(struct sk_buff *skb)
+{
+ struct ptp_header *hdr;
+ unsigned int ptp_class;
+ u8 msgtype, twostep;
+
+ ptp_class = ptp_classify_raw(skb);
+ if (ptp_class == PTP_CLASS_NONE)
+ return false;
+
+ hdr = ptp_parse_header(skb, ptp_class);
+ if (!hdr)
+ return false;
+
+ msgtype = ptp_get_msgtype(hdr, ptp_class);
+ twostep = hdr->flag_field[0] & 0x2;
+
+ if (msgtype == PTP_MSGTYPE_SYNC && twostep == 0)
+ return true;
+
+ return false;
+}
+
int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
struct sk_buff *skb,
struct sk_buff **clone)
@@ -553,12 +598,24 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
struct ocelot_port *ocelot_port = ocelot->ports[port];
u8 ptp_cmd = ocelot_port->ptp_cmd;

+ /* Store ptp_cmd in first byte of DSA_SKB_CB_PRIV per skb */
+ if (ptp_cmd == IFH_REW_OP_ORIGIN_PTP) {
+ if (ocelot_ptp_is_onestep_sync(skb)) {
+ *(u8 *)DSA_SKB_CB_PRIV(skb) = ptp_cmd;
+ return 0;
+ }
+
+ /* Fall back to two-step timestamping */
+ ptp_cmd = IFH_REW_OP_TWO_STEP_PTP;
+ }
+
if (ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
*clone = skb_clone_sk(skb);
if (!(*clone))
return -ENOMEM;

ocelot_port_add_txtstamp_skb(ocelot, port, *clone);
+ *(u8 *)DSA_SKB_CB_PRIV(skb) = ptp_cmd;
}

return 0;
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 8293152a6dc1..eb3d525731da 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -514,10 +514,7 @@ static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_OK;
}

- if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
- rew_op = ocelot_port->ptp_cmd;
- rew_op |= clone->cb[0] << 3;
- }
+ ocelot_ptp_rew_op(skb, clone, &rew_op);
}

ocelot_port_inject_frame(ocelot, port, 0, rew_op, skb);
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 9cdaf1d9199f..19413532db0b 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -820,6 +820,7 @@ int ocelot_vlan_add(struct ocelot *ocelot, int port, u16 vid, bool pvid,
int ocelot_vlan_del(struct ocelot *ocelot, int port, u16 vid);
int ocelot_hwstamp_get(struct ocelot *ocelot, int port, struct ifreq *ifr);
int ocelot_hwstamp_set(struct ocelot *ocelot, int port, struct ifreq *ifr);
+bool ocelot_ptp_rew_op(struct sk_buff *skb, struct sk_buff *clone, u32 *rew_op);
int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
struct sk_buff *skb,
struct sk_buff **clone);
diff --git a/net/dsa/tag_ocelot.c b/net/dsa/tag_ocelot.c
index f9df9cac81c5..d5c73b36f0c1 100644
--- a/net/dsa/tag_ocelot.c
+++ b/net/dsa/tag_ocelot.c
@@ -5,25 +5,6 @@
#include <soc/mscc/ocelot.h>
#include "dsa_priv.h"

-static void ocelot_xmit_ptp(struct dsa_port *dp, void *injection,
- struct sk_buff *clone)
-{
- struct ocelot *ocelot = dp->ds->priv;
- struct ocelot_port *ocelot_port;
- u64 rew_op;
-
- ocelot_port = ocelot->ports[dp->index];
- rew_op = ocelot_port->ptp_cmd;
-
- /* Retrieve timestamp ID populated inside skb->cb[0] of the
- * clone by ocelot_port_add_txtstamp_skb
- */
- if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)
- rew_op |= clone->cb[0] << 3;
-
- ocelot_ifh_set_rew_op(injection, rew_op);
-}
-
static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
__be32 ifh_prefix, void **ifh)
{
@@ -32,6 +13,7 @@ static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
struct dsa_switch *ds = dp->ds;
void *injection;
__be32 *prefix;
+ u32 rew_op = 0;

injection = skb_push(skb, OCELOT_TAG_LEN);
prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
@@ -42,9 +24,8 @@ static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
ocelot_ifh_set_src(injection, ds->num_ports);
ocelot_ifh_set_qos_class(injection, skb->priority);

- /* TX timestamping was requested */
- if (clone)
- ocelot_xmit_ptp(dp, injection, clone);
+ if (ocelot_ptp_rew_op(skb, clone, &rew_op))
+ ocelot_ifh_set_rew_op(injection, rew_op);

*ifh = injection;
}
diff --git a/net/dsa/tag_ocelot_8021q.c b/net/dsa/tag_ocelot_8021q.c
index 5f3e8e124a82..bf32649a5a7b 100644
--- a/net/dsa/tag_ocelot_8021q.c
+++ b/net/dsa/tag_ocelot_8021q.c
@@ -13,32 +13,6 @@
#include <soc/mscc/ocelot_ptp.h>
#include "dsa_priv.h"

-static struct sk_buff *ocelot_xmit_ptp(struct dsa_port *dp,
- struct sk_buff *skb,
- struct sk_buff *clone)
-{
- struct ocelot *ocelot = dp->ds->priv;
- struct ocelot_port *ocelot_port;
- int port = dp->index;
- u32 rew_op;
-
- if (!ocelot_can_inject(ocelot, 0))
- return NULL;
-
- ocelot_port = ocelot->ports[port];
- rew_op = ocelot_port->ptp_cmd;
-
- /* Retrieve timestamp ID populated inside skb->cb[0] of the
- * clone by ocelot_port_add_txtstamp_skb
- */
- if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)
- rew_op |= clone->cb[0] << 3;
-
- ocelot_port_inject_frame(ocelot, port, 0, rew_op, skb);
-
- return NULL;
-}
-
static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
@@ -47,10 +21,17 @@ static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
u16 queue_mapping = skb_get_queue_mapping(skb);
u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
struct sk_buff *clone = DSA_SKB_CB(skb)->clone;
+ struct ocelot *ocelot = dp->ds->priv;
+ int port = dp->index;
+ u32 rew_op = 0;
+
+ if (ocelot_ptp_rew_op(skb, clone, &rew_op)) {
+ if (!ocelot_can_inject(ocelot, 0))
+ return NULL;

- /* TX timestamping was requested, so inject through MMIO */
- if (clone)
- return ocelot_xmit_ptp(dp, skb, clone);
+ ocelot_port_inject_frame(ocelot, port, 0, rew_op, skb);
+ return NULL;
+ }

return dsa_8021q_xmit(skb, netdev, ETH_P_8021Q,
((pcp << VLAN_PRIO_SHIFT) | tx_vid));
--
2.25.1