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

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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: Christian Eggers <ceggers@arri.de>
Co-developed-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Christian Eggers 2023-01-10 14:19:24 +05:30 committed by David S. Miller
parent 2955762b37
commit 90188fff65
5 changed files with 108 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/net/dsa/microchip/ksz_common.c
View File

@ -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)

63
drivers/net/dsa/microchip/ksz_ptp.c
View File

@ -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;

4
drivers/net/dsa/microchip/ksz_ptp.h
View File

@ -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

21
include/linux/dsa/ksz_common.h
View File

@ -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)
{

25
net/dsa/tag_ksz.c
View File

@ -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)
*/