Messages in this thread Patch in this message | | | From | Arun Ramadoss <> | Subject | [Patch net-next v1 07/12] net: dsa: microchip: ptp: add packet reception timestamping | Date | Mon, 28 Nov 2022 16:02:22 +0530 |
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From: Christian Eggers <ceggers@arri.de>
This patch adds the routines for timestamping received ptp packets. Whenever the ptp packet is received, the 4 byte hardware time stamped value is append to its packet. This 4 byte value is extracted from the tail tag and reconstructed to absolute time and assigned to skb hwtstamp.
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>
--- RFC v2 -> Patch v1 - Fixed compilation issue --- drivers/net/dsa/microchip/ksz_common.c | 13 +++++ drivers/net/dsa/microchip/ksz_ptp.c | 28 +++++++++++ drivers/net/dsa/microchip/ksz_ptp.h | 6 +++ include/linux/dsa/ksz_common.h | 15 ++++++ net/dsa/tag_ksz.c | 68 +++++++++++++++++++++++--- 5 files changed, 124 insertions(+), 6 deletions(-)
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 9bfd7dd5cd31..306bdc1469d2 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -5,6 +5,7 @@ * Copyright (C) 2017-2019 Microchip Technology Inc. */ +#include <linux/dsa/ksz_common.h> #include <linux/delay.h> #include <linux/export.h> #include <linux/gpio/consumer.h> @@ -2453,6 +2454,17 @@ static enum dsa_tag_protocol ksz_get_tag_protocol(struct dsa_switch *ds, return proto; } +static int ksz_connect_tag_protocol(struct dsa_switch *ds, + enum dsa_tag_protocol proto) +{ + struct ksz_tagger_data *tagger_data; + + tagger_data = ksz_tagger_data(ds); + tagger_data->meta_tstamp_handler = ksz_tstamp_reconstruct; + + return 0; +} + static int ksz_port_vlan_filtering(struct dsa_switch *ds, int port, bool flag, struct netlink_ext_ack *extack) { @@ -2849,6 +2861,7 @@ static int ksz_switch_detect(struct ksz_device *dev) static const struct dsa_switch_ops ksz_switch_ops = { .get_tag_protocol = ksz_get_tag_protocol, + .connect_tag_protocol = ksz_connect_tag_protocol, .get_phy_flags = ksz_get_phy_flags, .setup = ksz_setup, .teardown = ksz_teardown, diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c index 515a40c9f107..d878e922c275 100644 --- a/drivers/net/dsa/microchip/ksz_ptp.c +++ b/drivers/net/dsa/microchip/ksz_ptp.c @@ -353,6 +353,34 @@ static int ksz_ptp_start_clock(struct ksz_device *dev) return 0; } +ktime_t ksz_tstamp_reconstruct(struct dsa_switch *ds, ktime_t tstamp) +{ + struct ksz_device *dev = ds->priv; + 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); +} + static const struct ptp_clock_info ksz_ptp_caps = { .owner = THIS_MODULE, .name = "Microchip Clock", diff --git a/drivers/net/dsa/microchip/ksz_ptp.h b/drivers/net/dsa/microchip/ksz_ptp.h index 5cec8f2e8420..13c06c24b488 100644 --- a/drivers/net/dsa/microchip/ksz_ptp.h +++ b/drivers/net/dsa/microchip/ksz_ptp.h @@ -30,6 +30,7 @@ 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); int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p); void ksz_ptp_irq_free(struct dsa_switch *ds, u8 p); +ktime_t ksz_tstamp_reconstruct(struct dsa_switch *ds, ktime_t tstamp); #else @@ -66,6 +67,11 @@ static inline int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p) static inline void ksz_ptp_irq_free(struct dsa_switch *ds, u8 p) {} +static inline ktime_t ksz_tstamp_reconstruct(struct dsa_switch *ds, ktime_t tstamp) +{ + return 0; +} + #endif /* End of CONFIG_NET_DSA_MICROCHIP_KSZ_PTP */ #endif diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h index 62996860b887..0be0cd903727 100644 --- a/include/linux/dsa/ksz_common.h +++ b/include/linux/dsa/ksz_common.h @@ -9,9 +9,24 @@ #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 { bool (*hwtstamp_get_state)(struct dsa_switch *ds); void (*hwtstamp_set_state)(struct dsa_switch *ds, bool on); + ktime_t (*meta_tstamp_handler)(struct dsa_switch *ds, ktime_t tstamp); }; static inline struct ksz_tagger_data * diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c index 828af38f0598..41ce5ff5ed41 100644 --- a/net/dsa/tag_ksz.c +++ b/net/dsa/tag_ksz.c @@ -7,6 +7,7 @@ #include <linux/dsa/ksz_common.h> #include <linux/etherdevice.h> #include <linux/list.h> +#include <linux/ptp_classify.h> #include <net/dsa.h> #include "tag.h" @@ -157,10 +158,11 @@ 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) */ @@ -172,6 +174,57 @@ 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, + struct net_device *dev, unsigned int port) +{ + struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); + struct dsa_switch *ds = dev->dsa_ptr->ds; + u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN; + struct ksz_tagger_data *tagger_data; + struct ptp_header *ptp_hdr; + unsigned int ptp_type; + u8 ptp_msg_type; + ktime_t tstamp; + s64 correction; + + tagger_data = ksz_tagger_data(ds); + if (!tagger_data->meta_tstamp_handler) + return; + + /* convert time stamp and write to skb */ + tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw)); + memset(hwtstamps, 0, sizeof(*hwtstamps)); + hwtstamps->hwtstamp = tagger_data->meta_tstamp_handler(ds, tstamp); + + if (skb_headroom(skb) < ETH_HLEN) + return; + + __skb_push(skb, ETH_HLEN); + ptp_type = ptp_classify_raw(skb); + __skb_pull(skb, ETH_HLEN); + + if (ptp_type == PTP_CLASS_NONE) + return; + + ptp_hdr = ptp_parse_header(skb, ptp_type); + if (!ptp_hdr) + return; + + ptp_msg_type = ptp_get_msgtype(ptp_hdr, ptp_type); + if (ptp_msg_type != PTP_MSGTYPE_PDELAY_REQ) + return; + + /* 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, ptp_type, ptp_hdr, correction); +} + /* Time stamp tag is only inserted if PTP is enabled in hardware. */ static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb) { @@ -220,8 +273,10 @@ 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, dev, port); + len += KSZ_PTP_TAG_LEN; + } return ksz_common_rcv(skb, dev, port, len); } @@ -287,10 +342,11 @@ 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) */ -- 2.36.1
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