Re: [PATCH v2 net-next 12/14] net: enetc: add PTP synchronization support for ENETC v4

[Frank Li]

On Thu, Jul 17, 2025 at 12:35:10PM +0000, Wei Fang wrote:
> > > +static void enetc_set_one_step_ts(struct enetc_si *si, bool udp, int
> > > +offset) {
> > > +	u32 val = ENETC_PM0_SINGLE_STEP_EN;
> > > +
> > > +	val |= ENETC_SET_SINGLE_STEP_OFFSET(offset);
> > > +	if (udp)
> > > +		val |= ENETC_PM0_SINGLE_STEP_CH;
> > > +
> > > +	/* the "Correction" field of a packet is updated based on the
> > > +	 * current time and the timestamp provided
> > > +	 */
> > > +	enetc_port_mac_wr(si, ENETC_PM0_SINGLE_STEP, val); }
> > > +
> > > +static void enetc4_set_one_step_ts(struct enetc_si *si, bool udp, int
> > > +offset) {
> > > +	u32 val = PM_SINGLE_STEP_EN;
> > > +
> > > +	val |= PM_SINGLE_STEP_OFFSET_SET(offset);
> > > +	if (udp)
> > > +		val |= PM_SINGLE_STEP_CH;
> > > +
> > > +	enetc_port_mac_wr(si, ENETC4_PM_SINGLE_STEP(0), val); }
> > > +
> > >  static u32 enetc_update_ptp_sync_msg(struct enetc_ndev_priv *priv,
> > >  				     struct sk_buff *skb)
> > >  {
> > > @@ -234,7 +259,6 @@ static u32 enetc_update_ptp_sync_msg(struct
> > enetc_ndev_priv *priv,
> > >  	u32 lo, hi, nsec;
> > >  	u8 *data;
> > >  	u64 sec;
> > > -	u32 val;
> > >
> > >  	lo = enetc_rd_hot(hw, ENETC_SICTR0);
> > >  	hi = enetc_rd_hot(hw, ENETC_SICTR1); @@ -279,12 +303,10 @@ static
> > > u32 enetc_update_ptp_sync_msg(struct enetc_ndev_priv *priv,
> > >  	*(__be32 *)(data + tstamp_off + 6) = new_nsec;
> > >
> > >  	/* Configure single-step register */
> > > -	val = ENETC_PM0_SINGLE_STEP_EN;
> > > -	val |= ENETC_SET_SINGLE_STEP_OFFSET(corr_off);
> > > -	if (enetc_cb->udp)
> > > -		val |= ENETC_PM0_SINGLE_STEP_CH;
> > > -
> > > -	enetc_port_mac_wr(priv->si, ENETC_PM0_SINGLE_STEP, val);
> > > +	if (is_enetc_rev1(si))
> > > +		enetc_set_one_step_ts(si, enetc_cb->udp, corr_off);
> > > +	else
> > > +		enetc4_set_one_step_ts(si, enetc_cb->udp, corr_off);
> >
> > Can you use callback function to avoid change this logic when new version
> > appear in future?
>
> According to Jakub's previous suggestion, there is no need to add callbacks
> for such trivial things.
> https://lore.kernel.org/imx/20250115140042.63b99c4f@xxxxxxxxxx/
>
> If the differences between the two versions result in a lot of different
> code, using a callback is more appropriate.
>
> >
> > >
> > >  	return lo & ENETC_TXBD_TSTAMP;
> > >  }
> > > @@ -303,6 +325,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr
> > *tx_ring, struct sk_buff *skb)
> > >  	unsigned int f;
> > >  	dma_addr_t dma;
> > >  	u8 flags = 0;
> > > +	u32 tstamp;
> > >
> > >  	enetc_clear_tx_bd(&temp_bd);
> > >  	if (skb->ip_summed == CHECKSUM_PARTIAL) { @@ -327,6 +350,13 @@
> > > static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
> > >  		}
> > >  	}
> > >
> > > +	if (enetc_cb->flag & ENETC_F_TX_ONESTEP_SYNC_TSTAMP) {
> > > +		do_onestep_tstamp = true;
> > > +		tstamp = enetc_update_ptp_sync_msg(priv, skb);
> > > +	} else if (enetc_cb->flag & ENETC_F_TX_TSTAMP) {
> > > +		do_twostep_tstamp = true;
> > > +	}
> > > +
> > >  	i = tx_ring->next_to_use;
> > >  	txbd = ENETC_TXBD(*tx_ring, i);
> > >  	prefetchw(txbd);
> > > @@ -346,11 +376,6 @@ static int enetc_map_tx_buffs(struct enetc_bdr
> > *tx_ring, struct sk_buff *skb)
> > >  	count++;
> > >
> > >  	do_vlan = skb_vlan_tag_present(skb);
> > > -	if (enetc_cb->flag & ENETC_F_TX_ONESTEP_SYNC_TSTAMP)
> > > -		do_onestep_tstamp = true;
> > > -	else if (enetc_cb->flag & ENETC_F_TX_TSTAMP)
> > > -		do_twostep_tstamp = true;
> > > -
> >
> > why need move this block up?
>
> Because we need check the flag to determine whether perform PTP
> one-step, if yes, we need to call enetc_update_ptp_sync_msg() to
> modify the sync packet before calling dma_map_single(). ENETCv4
> do not support dma-coherent, I have explained in the commit message.
>
> >
> > >  	tx_swbd->do_twostep_tstamp = do_twostep_tstamp;
> > >  	tx_swbd->qbv_en = !!(priv->active_offloads & ENETC_F_QBV);
> > >  	tx_swbd->check_wb = tx_swbd->do_twostep_tstamp ||
> > tx_swbd->qbv_en;
> > > @@ -393,8 +418,6 @@ static int enetc_map_tx_buffs(struct enetc_bdr
> > *tx_ring, struct sk_buff *skb)
> > >  		}
> > >
> > >  		if (do_onestep_tstamp) {
> > > -			u32 tstamp = enetc_update_ptp_sync_msg(priv, skb);
> > > -
> > >  			/* Configure extension BD */
> > >  			temp_bd.ext.tstamp = cpu_to_le32(tstamp);
> > >  			e_flags |= ENETC_TXBD_E_FLAGS_ONE_STEP_PTP; @@ -3314,7
> > +3337,7 @@
> > > int enetc_hwtstamp_set(struct net_device *ndev,
> > >  	struct enetc_ndev_priv *priv = netdev_priv(ndev);
> > >  	int err, new_offloads = priv->active_offloads;
> > >
> > > -	if (!IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK))
> > > +	if (!enetc_ptp_clock_is_enabled(priv->si))
> > >  		return -EOPNOTSUPP;
> > >
> > >  	switch (config->tx_type) {
> > > @@ -3364,7 +3387,7 @@ int enetc_hwtstamp_get(struct net_device *ndev,
> > > {
> > >  	struct enetc_ndev_priv *priv = netdev_priv(ndev);
> > >
> > > -	if (!IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK))
> > > +	if (!enetc_ptp_clock_is_enabled(priv->si))
> > >  		return -EOPNOTSUPP;
> > >
> > >  	if (priv->active_offloads & ENETC_F_TX_ONESTEP_SYNC_TSTAMP) diff
> > > --git a/drivers/net/ethernet/freescale/enetc/enetc.h
> > > b/drivers/net/ethernet/freescale/enetc/enetc.h
> > > index c65aa7b88122..6bacd851358c 100644
> > > --- a/drivers/net/ethernet/freescale/enetc/enetc.h
> > > +++ b/drivers/net/ethernet/freescale/enetc/enetc.h
> > > @@ -598,6 +598,14 @@ static inline void enetc_cbd_free_data_mem(struct
> > > enetc_si *si, int size,  void enetc_reset_ptcmsdur(struct enetc_hw
> > > *hw);  void enetc_set_ptcmsdur(struct enetc_hw *hw, u32
> > > *queue_max_sdu);
> > >
> > > +static inline bool enetc_ptp_clock_is_enabled(struct enetc_si *si) {
> > > +	if (is_enetc_rev1(si))
> > > +		return IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK);
> > > +
> > > +	return IS_ENABLED(CONFIG_PTP_1588_CLOCK_NETC);
> > > +}
> > > +
> >
> > why v1 check CONFIG_FSL_ENETC_PTP_CLOCK and other check
> > CONFIG_PTP_1588_CLOCK_NETC
>
> Because they use different PTP drivers, so the configs are different.

But name CONFIG_FSL_ENETC_PTP_CLOCK and CONFIG_PTP_1588_CLOCK_NETC is quite
similar, suppose CONFIG_PTP_1588_CLOCK_NETC should be
CONFIG_PTP_1588_CLOCK_NETC_V4

Frank

>