Re: [PATCH net-next v6 2/5] net: phy: microchip_rds_ptp : Add rds ptp library for Microchip phys

[Paolo Abeni <pabeni@redhat.com>]

On 12/9/24 16:17, Divya Koppera wrote:
> diff --git a/drivers/net/phy/microchip_rds_ptp.c b/drivers/net/phy/microchip_rds_ptp.c
> new file mode 100644
> index 000000000000..d1c91c0f5e03
> --- /dev/null
> +++ b/drivers/net/phy/microchip_rds_ptp.c
> @@ -0,0 +1,1009 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2024 Microchip Technology
> +
> +#include "microchip_rds_ptp.h"
> +
> +static int mchp_rds_ptp_flush_fifo(struct mchp_rds_ptp_clock *clock,
> +				   enum mchp_rds_ptp_fifo_dir dir)

If you pass as 2nd argument the relevant fifo to flush compute 'dir'
from such value and call skb_queue_purge(), you can avoid a bit of
duplicate code.

> +{
> +	struct phy_device *phydev = clock->phydev;
> +	int rc;
> +
> +	for (int i = 0; i < MCHP_RDS_PTP_FIFO_SIZE; ++i) {
> +		rc = phy_read_mmd(phydev, PTP_MMD(clock),
> +				  dir == MCHP_RDS_PTP_EGRESS_FIFO ?
> +				  MCHP_RDS_PTP_TX_MSG_HDR2(BASE_PORT(clock)) :
> +				  MCHP_RDS_PTP_RX_MSG_HDR2(BASE_PORT(clock)));
> +		if (rc < 0)
> +			return rc;
> +	}
> +	return phy_read_mmd(phydev, PTP_MMD(clock),
> +			    MCHP_RDS_PTP_INT_STS(BASE_PORT(clock)));
> +}
> +
> +static int mchp_rds_ptp_config_intr(struct mchp_rds_ptp_clock *clock,
> +				    bool enable)
> +{
> +	struct phy_device *phydev = clock->phydev;
> +
> +	/* Enable  or disable ptp interrupts */
> +	return phy_write_mmd(phydev, PTP_MMD(clock),
> +			     MCHP_RDS_PTP_INT_EN(BASE_PORT(clock)),
> +			     enable ? MCHP_RDS_PTP_INT_ALL_MSK : 0);
> +}
> +
> +static void mchp_rds_ptp_txtstamp(struct mii_timestamper *mii_ts,
> +				  struct sk_buff *skb, int type)
> +{
> +	struct mchp_rds_ptp_clock *clock = container_of(mii_ts,
> +						      struct mchp_rds_ptp_clock,
> +						      mii_ts);
> +
> +	switch (clock->hwts_tx_type) {
> +	case HWTSTAMP_TX_ONESTEP_SYNC:
> +		if (ptp_msg_is_sync(skb, type)) {
> +			kfree_skb(skb);
> +			return;
> +		}
> +		fallthrough;
> +	case HWTSTAMP_TX_ON:
> +		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
> +		skb_queue_tail(&clock->tx_queue, skb);
> +		break;
> +	case HWTSTAMP_TX_OFF:
> +	default:
> +		kfree_skb(skb);
> +		break;
> +	}
> +}
> +
> +static bool mchp_rds_ptp_get_sig_rx(struct sk_buff *skb, u16 *sig)
> +{
> +	struct ptp_header *ptp_header;
> +	int type;
> +
> +	skb_push(skb, ETH_HLEN);
> +	type = ptp_classify_raw(skb);
> +	if (type == PTP_CLASS_NONE)
> +		return false;
> +
> +	ptp_header = ptp_parse_header(skb, type);
> +	if (!ptp_header)
> +		return false;
> +
> +	skb_pull_inline(skb, ETH_HLEN);
> +
> +	*sig = (__force u16)(ntohs(ptp_header->sequence_id));
> +
> +	return true;
> +}
> +
> +static bool mchp_rds_ptp_match_skb(struct mchp_rds_ptp_clock *clock,
> +				   struct mchp_rds_ptp_rx_ts *rx_ts)
> +{
> +	struct skb_shared_hwtstamps *shhwtstamps;
> +	struct sk_buff *skb, *skb_tmp;
> +	unsigned long flags;
> +	bool rc = false;
> +	u16 skb_sig;
> +
> +	spin_lock_irqsave(&clock->rx_queue.lock, flags);
> +	skb_queue_walk_safe(&clock->rx_queue, skb, skb_tmp) {
> +		if (!mchp_rds_ptp_get_sig_rx(skb, &skb_sig))
> +			continue;
> +
> +		if (skb_sig != rx_ts->seq_id)
> +			continue;
> +
> +		__skb_unlink(skb, &clock->rx_queue);
> +
> +		rc = true;
> +		break;
> +	}
> +	spin_unlock_irqrestore(&clock->rx_queue.lock, flags);
> +
> +	if (rc) {
> +		shhwtstamps = skb_hwtstamps(skb);
> +		shhwtstamps->hwtstamp = ktime_set(rx_ts->seconds, rx_ts->nsec);
> +		netif_rx(skb);
> +	}
> +
> +	return rc;
> +}
> +
> +static void mchp_rds_ptp_match_rx_ts(struct mchp_rds_ptp_clock *clock,
> +				     struct mchp_rds_ptp_rx_ts *rx_ts)
> +{
> +	unsigned long flags;
> +
> +	/* If we failed to match the skb add it to the queue for when
> +	 * the frame will come
> +	 */
> +	if (!mchp_rds_ptp_match_skb(clock, rx_ts)) {
> +		spin_lock_irqsave(&clock->rx_ts_lock, flags);
> +		list_add(&rx_ts->list, &clock->rx_ts_list);
> +		spin_unlock_irqrestore(&clock->rx_ts_lock, flags);
> +	} else {
> +		kfree(rx_ts);
> +	}
> +}
> +
> +static void mchp_rds_ptp_match_rx_skb(struct mchp_rds_ptp_clock *clock,
> +				      struct sk_buff *skb)
> +{
> +	struct mchp_rds_ptp_rx_ts *rx_ts, *tmp, *rx_ts_var = NULL;
> +	struct skb_shared_hwtstamps *shhwtstamps;
> +	unsigned long flags;
> +	u16 skb_sig;
> +
> +	if (!mchp_rds_ptp_get_sig_rx(skb, &skb_sig))
> +		return;
> +
> +	/* Iterate over all RX timestamps and match it with the received skbs */
> +	spin_lock_irqsave(&clock->rx_ts_lock, flags);
> +	list_for_each_entry_safe(rx_ts, tmp, &clock->rx_ts_list, list) {
> +		/* Check if we found the signature we were looking for. */
> +		if (skb_sig != rx_ts->seq_id)
> +			continue;
> +
> +		shhwtstamps = skb_hwtstamps(skb);
> +		shhwtstamps->hwtstamp = ktime_set(rx_ts->seconds, rx_ts->nsec);
> +		netif_rx(skb);
> +
> +		rx_ts_var = rx_ts;
> +
> +		break;
> +	}
> +	spin_unlock_irqrestore(&clock->rx_ts_lock, flags);
> +
> +	if (rx_ts_var) {
> +		list_del(&rx_ts_var->list);
> +		kfree(rx_ts_var);
> +	} else {
> +		skb_queue_tail(&clock->rx_queue, skb);
> +	}
> +}
> +
> +static bool mchp_rds_ptp_rxtstamp(struct mii_timestamper *mii_ts,
> +				  struct sk_buff *skb, int type)
> +{
> +	struct mchp_rds_ptp_clock *clock = container_of(mii_ts,
> +						      struct mchp_rds_ptp_clock,
> +						      mii_ts);
> +
> +	if (clock->rx_filter == HWTSTAMP_FILTER_NONE ||
> +	    type == PTP_CLASS_NONE)
> +		return false;
> +
> +	if ((type & clock->version) == 0 || (type & clock->layer) == 0)
> +		return false;
> +
> +	/* Here if match occurs skb is sent to application, If not skb is added
> +	 * to queue and sending skb to application will get handled when
> +	 * interrupt occurs i.e., it get handles in interrupt handler. By
> +	 * any means skb will reach the application so we should not return
> +	 * false here if skb doesn't matches.
> +	 */
> +	mchp_rds_ptp_match_rx_skb(clock, skb);
> +
> +	return true;
> +}
> +
> +static int mchp_rds_ptp_hwtstamp(struct mii_timestamper *mii_ts,
> +				 struct kernel_hwtstamp_config *config,
> +				 struct netlink_ext_ack *extack)
> +{
> +	struct mchp_rds_ptp_clock *clock =
> +				container_of(mii_ts, struct mchp_rds_ptp_clock,
> +					     mii_ts);
> +	struct phy_device *phydev = clock->phydev;
> +	struct mchp_rds_ptp_rx_ts *rx_ts, *tmp;
> +	int txcfg = 0, rxcfg = 0;
> +	unsigned long flags;
> +	int rc;
> +
> +	clock->hwts_tx_type = config->tx_type;
> +	clock->rx_filter = config->rx_filter;
> +
> +	switch (config->rx_filter) {
> +	case HWTSTAMP_FILTER_NONE:
> +		clock->layer = 0;
> +		clock->version = 0;
> +		break;
> +	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
> +	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
> +	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
> +		clock->layer = PTP_CLASS_L4;
> +		clock->version = PTP_CLASS_V2;
> +		break;
> +	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
> +	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
> +	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
> +		clock->layer = PTP_CLASS_L2;
> +		clock->version = PTP_CLASS_V2;
> +		break;
> +	case HWTSTAMP_FILTER_PTP_V2_EVENT:
> +	case HWTSTAMP_FILTER_PTP_V2_SYNC:
> +	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
> +		clock->layer = PTP_CLASS_L4 | PTP_CLASS_L2;
> +		clock->version = PTP_CLASS_V2;
> +		break;
> +	default:
> +		return -ERANGE;
> +	}
> +
> +	/* Setup parsing of the frames and enable the timestamping for ptp
> +	 * frames
> +	 */
> +	if (clock->layer & PTP_CLASS_L2) {
> +		rxcfg = MCHP_RDS_PTP_PARSE_CONFIG_LAYER2_EN;
> +		txcfg = MCHP_RDS_PTP_PARSE_CONFIG_LAYER2_EN;
> +	}
> +	if (clock->layer & PTP_CLASS_L4) {
> +		rxcfg |= MCHP_RDS_PTP_PARSE_CONFIG_IPV4_EN |
> +			 MCHP_RDS_PTP_PARSE_CONFIG_IPV6_EN;
> +		txcfg |= MCHP_RDS_PTP_PARSE_CONFIG_IPV4_EN |
> +			 MCHP_RDS_PTP_PARSE_CONFIG_IPV6_EN;
> +	}
> +	rc = phy_write_mmd(phydev, PTP_MMD(clock),
> +			   MCHP_RDS_PTP_RX_PARSE_CONFIG(BASE_PORT(clock)),
> +			   rxcfg);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = phy_write_mmd(phydev, PTP_MMD(clock),
> +			   MCHP_RDS_PTP_TX_PARSE_CONFIG(BASE_PORT(clock)),
> +			   txcfg);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = phy_write_mmd(phydev, PTP_MMD(clock),
> +			   MCHP_RDS_PTP_RX_TIMESTAMP_EN(BASE_PORT(clock)),
> +			   MCHP_RDS_PTP_TIMESTAMP_EN_ALL);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = phy_write_mmd(phydev, PTP_MMD(clock),
> +			   MCHP_RDS_PTP_TX_TIMESTAMP_EN(BASE_PORT(clock)),
> +			   MCHP_RDS_PTP_TIMESTAMP_EN_ALL);
> +	if (rc < 0)
> +		return rc;
> +
> +	if (clock->hwts_tx_type == HWTSTAMP_TX_ONESTEP_SYNC)
> +		/* Enable / disable of the TX timestamp in the SYNC frames */
> +		rc = phy_modify_mmd(phydev, PTP_MMD(clock),
> +				    MCHP_RDS_PTP_TX_MOD(BASE_PORT(clock)),
> +				    MCHP_RDS_PTP_TX_MOD_PTP_SYNC_TS_INSERT,
> +				    MCHP_RDS_PTP_TX_MOD_PTP_SYNC_TS_INSERT);
> +	else
> +		rc = phy_modify_mmd(phydev, PTP_MMD(clock),
> +				    MCHP_RDS_PTP_TX_MOD(BASE_PORT(clock)),
> +				    MCHP_RDS_PTP_TX_MOD_PTP_SYNC_TS_INSERT,
> +				(u16)~MCHP_RDS_PTP_TX_MOD_PTP_SYNC_TS_INSERT);
> +
> +	if (rc < 0)
> +		return rc;
> +
> +	/* Now enable the timestamping interrupts */
> +	rc = mchp_rds_ptp_config_intr(clock,
> +				      config->rx_filter !=
> +				      HWTSTAMP_FILTER_NONE);
> +	if (rc < 0)
> +		return rc;

At this point the H/W can trigger ptp interruts and
mchp_rds_ptp_handle_interrupt() right?

> +
> +	/* In case of multiple starts and stops, these needs to be cleared */
> +	spin_lock_irqsave(&clock->rx_ts_lock, flags);
> +	list_for_each_entry_safe(rx_ts, tmp, &clock->rx_ts_list, list) {
> +		list_del(&rx_ts->list);
> +		kfree(rx_ts);
> +	}
> +	spin_unlock_irqrestore(&clock->rx_ts_lock, flags);
> +	skb_queue_purge(&clock->rx_queue);
> +	skb_queue_purge(&clock->tx_queue);
> +
> +	rc = mchp_rds_ptp_flush_fifo(clock, MCHP_RDS_PTP_INGRESS_FIFO);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = mchp_rds_ptp_flush_fifo(clock, MCHP_RDS_PTP_EGRESS_FIFO);
Should the above moved bedore enabling the irqs?

Thanks!

Paolo