Commit 90188fff authored by Christian Eggers's avatar Christian Eggers Committed by David S. Miller
Browse files

net: dsa: microchip: ptp: add packet reception timestamping 



Rx Timestamping is done through 4 additional bytes in tail tag.
Whenever the ptp packet is received, the 4 byte hardware time stamped
value is added before 1 byte tail tag. Also, bit 7 in tail tag indicates
it as PTP frame. This 4 byte value is extracted from the tail tag and
reconstructed to absolute time and assigned to skb hwtstamp.
If the packet received in PDelay_Resp, then partial ingress timestamp
is subtracted from the correction field. Since user space tools expects
to be done in hardware.

Signed-off-by: default avatarChristian Eggers <ceggers@arri.de>
Co-developed-by: default avatarArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: default avatarArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: default avatarVladimir Oltean <olteanv@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2955762b

drivers/net/dsa/microchip/ksz_common.c

+1 −0
Original line number Diff line number Diff line
@@ -2991,6 +2991,7 @@ static const struct dsa_switch_ops ksz_switch_ops = { 
	.get_ts_info		= ksz_get_ts_info,

	.port_hwtstamp_get	= ksz_hwtstamp_get,

	.port_hwtstamp_set	= ksz_hwtstamp_set,

	.port_rxtstamp		= ksz_port_rxtstamp,

};



struct ksz_device *ksz_switch_alloc(struct device *base, void *priv)

drivers/net/dsa/microchip/ksz_ptp.c

+63 −0
Original line number Diff line number Diff line
@@ -169,6 +169,69 @@ int ksz_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr) 
	return copy_to_user(ifr->ifr_data, &config, sizeof(config));

}



static ktime_t ksz_tstamp_reconstruct(struct ksz_device *dev, ktime_t tstamp)

{

	struct timespec64 ptp_clock_time;

	struct ksz_ptp_data *ptp_data;

	struct timespec64 diff;

	struct timespec64 ts;



	ptp_data = &dev->ptp_data;

	ts = ktime_to_timespec64(tstamp);



	spin_lock_bh(&ptp_data->clock_lock);

	ptp_clock_time = ptp_data->clock_time;

	spin_unlock_bh(&ptp_data->clock_lock);



	/* calculate full time from partial time stamp */

	ts.tv_sec = (ptp_clock_time.tv_sec & ~3) | ts.tv_sec;



	/* find nearest possible point in time */

	diff = timespec64_sub(ts, ptp_clock_time);

	if (diff.tv_sec > 2)

		ts.tv_sec -= 4;

	else if (diff.tv_sec < -2)

		ts.tv_sec += 4;



	return timespec64_to_ktime(ts);

}



bool ksz_port_rxtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb,

		       unsigned int type)

{

	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);

	struct ksz_device *dev = ds->priv;

	struct ptp_header *ptp_hdr;

	u8 ptp_msg_type;

	ktime_t tstamp;

	s64 correction;



	tstamp = KSZ_SKB_CB(skb)->tstamp;

	memset(hwtstamps, 0, sizeof(*hwtstamps));

	hwtstamps->hwtstamp = ksz_tstamp_reconstruct(dev, tstamp);



	ptp_hdr = ptp_parse_header(skb, type);

	if (!ptp_hdr)

		goto out;



	ptp_msg_type = ptp_get_msgtype(ptp_hdr, type);

	if (ptp_msg_type != PTP_MSGTYPE_PDELAY_REQ)

		goto out;



	/* Only subtract the partial time stamp from the correction field.  When

	 * the hardware adds the egress time stamp to the correction field of

	 * the PDelay_Resp message on tx, also only the partial time stamp will

	 * be added.

	 */

	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);

	correction -= ktime_to_ns(tstamp) << 16;



	ptp_header_update_correction(skb, type, ptp_hdr, correction);



out:

	return false;

}



static int _ksz_ptp_gettime(struct ksz_device *dev, struct timespec64 *ts)

{

	u32 nanoseconds;

drivers/net/dsa/microchip/ksz_ptp.h

+4 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 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);

int ksz_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr);

bool ksz_port_rxtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb,

		       unsigned int type);

int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p);

void ksz_ptp_irq_free(struct dsa_switch *ds, u8 p);
@@ -60,6 +62,8 @@ static inline void ksz_ptp_irq_free(struct dsa_switch *ds, u8 p) {} 


#define ksz_hwtstamp_set NULL



#define ksz_port_rxtstamp NULL



#endif	/* End of CONFIG_NET_DSA_MICROCHIP_KSZ_PTP */



#endif

include/linux/dsa/ksz_common.h

+21 −0
Original line number Diff line number Diff line
@@ -9,10 +9,31 @@ 


#include <net/dsa.h>



/* All time stamps from the KSZ consist of 2 bits for seconds and 30 bits for

 * nanoseconds. This is NOT the same as 32 bits for nanoseconds.

 */

#define KSZ_TSTAMP_SEC_MASK  GENMASK(31, 30)

#define KSZ_TSTAMP_NSEC_MASK GENMASK(29, 0)



static inline ktime_t ksz_decode_tstamp(u32 tstamp)

{

	u64 ns = FIELD_GET(KSZ_TSTAMP_SEC_MASK, tstamp) * NSEC_PER_SEC +

		 FIELD_GET(KSZ_TSTAMP_NSEC_MASK, tstamp);



	return ns_to_ktime(ns);

}



struct ksz_tagger_data {

	void (*hwtstamp_set_state)(struct dsa_switch *ds, bool on);

};



struct ksz_skb_cb {

	u32 tstamp;

};



#define KSZ_SKB_CB(skb) \

	((struct ksz_skb_cb *)((skb)->cb))



static inline struct ksz_tagger_data *

ksz_tagger_data(struct dsa_switch *ds)

{

net/dsa/tag_ksz.c

+19 −6
Original line number Diff line number Diff line
@@ -151,10 +151,11 @@ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME); 
 * 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)

 */
@@ -166,6 +167,15 @@ 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.

 */
@@ -216,8 +226,10 @@ 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);

}
@@ -284,10 +296,11 @@ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME); 
 * 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)

 */