From c2977c61f32e0d54319d158a04cad5fd82c2afcf Mon Sep 17 00:00:00 2001 From: Arun Ramadoss Date: Tue, 10 Jan 2023 14:19:20 +0530 Subject: net: dsa: microchip: ptp: add 4 bytes in tail tag when ptp enabled When the PTP is enabled in hardware bit 6 of PTP_MSG_CONF1 register, the transmit frame needs additional 4 bytes before the tail tag. It is needed for all the transmission packets irrespective of PTP packets or not. The 4-byte timestamp field is 0 for frames other than Pdelay_Resp. For the one-step Pdelay_Resp, the switch needs the receive timestamp of the Pdelay_Req message so that it can put the turnaround time in the correction field. Since PTP has to be enabled for both Transmission and reception timestamping, driver needs to track of the tx and rx setting of the all the user ports in the switch. Two flags hw_tx_en and hw_rx_en are added in ksz_port to track the timestampping setting of each port. When any one of ports has tx or rx timestampping enabled, bit 6 of PTP_MSG_CONF1 is set and it is indicated to tag_ksz.c through tagger bytes. This flag adds 4 additional bytes to the tail tag. When tx and rx timestamping of all the ports are disabled, then 4 bytes are not added. Tested using hwstamp -i Signed-off-by: Arun Ramadoss Reviewed-by: Vladimir Oltean # mostly api Signed-off-by: David S. Miller --- include/linux/dsa/ksz_common.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 include/linux/dsa/ksz_common.h (limited to 'include/linux') diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h new file mode 100644 index 000000000000..d2a54161be97 --- /dev/null +++ b/include/linux/dsa/ksz_common.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Microchip switch tag common header + * + * Copyright (C) 2022 Microchip Technology Inc. + */ + +#ifndef _NET_DSA_KSZ_COMMON_H_ +#define _NET_DSA_KSZ_COMMON_H_ + +#include + +struct ksz_tagger_data { + void (*hwtstamp_set_state)(struct dsa_switch *ds, bool on); +}; + +static inline struct ksz_tagger_data * +ksz_tagger_data(struct dsa_switch *ds) +{ + return ds->tagger_data; +} + +#endif /* _NET_DSA_KSZ_COMMON_H_ */ -- cgit v1.2.3 From 2955762b372b791a8f4cd862cf0b5fef9c456449 Mon Sep 17 00:00:00 2001 From: Christian Eggers Date: Tue, 10 Jan 2023 14:19:23 +0530 Subject: net: ptp: add helper for one-step P2P clocks For P2P delay measurement, the ingress time stamp of the PDelay_Req is required for the correction field of the PDelay_Resp. The application echoes back the correction field of the PDelay_Req when sending the PDelay_Resp. Some hardware (like the ZHAW InES PTP time stamping IP core) subtracts the ingress timestamp autonomously from the correction field, so that the hardware only needs to add the egress timestamp on tx. Other hardware (like the Microchip KSZ9563) reports the ingress time stamp via an interrupt and requires that the software provides this time stamp via tail-tag on tx. In order to avoid introducing a further application interface for this, the driver can simply emulate the behavior of the InES device and subtract the ingress time stamp in software from the correction field. On egress, the correction field can either be kept as it is (and the time stamp field in the tail-tag is set to zero) or move the value from the correction field back to the tail-tag. Changing the correction field requires updating the UDP checksum (if UDP is used as transport). Signed-off-by: Christian Eggers Co-developed-by: Arun Ramadoss Signed-off-by: Arun Ramadoss Signed-off-by: David S. Miller --- include/linux/ptp_classify.h | 73 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h index 2b6ea36ad162..1b5a953c6bbc 100644 --- a/include/linux/ptp_classify.h +++ b/include/linux/ptp_classify.h @@ -10,8 +10,12 @@ #ifndef _PTP_CLASSIFY_H_ #define _PTP_CLASSIFY_H_ +#include #include +#include #include +#include +#include #define PTP_CLASS_NONE 0x00 /* not a PTP event message */ #define PTP_CLASS_V1 0x01 /* protocol version 1 */ @@ -129,6 +133,69 @@ static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, return msgtype; } +/** + * ptp_check_diff8 - Computes new checksum (when altering a 64-bit field) + * @old: old field value + * @new: new field value + * @oldsum: previous checksum + * + * This function can be used to calculate a new checksum when only a single + * field is changed. Similar as ip_vs_check_diff*() in ip_vs.h. + * + * Return: Updated checksum + */ +static inline __wsum ptp_check_diff8(__be64 old, __be64 new, __wsum oldsum) +{ + __be64 diff[2] = { ~old, new }; + + return csum_partial(diff, sizeof(diff), oldsum); +} + +/** + * ptp_header_update_correction - Update PTP header's correction field + * @skb: packet buffer + * @type: type of the packet (see ptp_classify_raw()) + * @hdr: ptp header + * @correction: new correction value + * + * This updates the correction field of a PTP header and updates the UDP + * checksum (if UDP is used as transport). It is needed for hardware capable of + * one-step P2P that does not already modify the correction field of Pdelay_Req + * event messages on ingress. + */ +static inline +void ptp_header_update_correction(struct sk_buff *skb, unsigned int type, + struct ptp_header *hdr, s64 correction) +{ + __be64 correction_old; + struct udphdr *uhdr; + + /* previous correction value is required for checksum update. */ + memcpy(&correction_old, &hdr->correction, sizeof(correction_old)); + + /* write new correction value */ + put_unaligned_be64((u64)correction, &hdr->correction); + + switch (type & PTP_CLASS_PMASK) { + case PTP_CLASS_IPV4: + case PTP_CLASS_IPV6: + /* locate udp header */ + uhdr = (struct udphdr *)((char *)hdr - sizeof(struct udphdr)); + break; + default: + return; + } + + /* update checksum */ + uhdr->check = csum_fold(ptp_check_diff8(correction_old, + hdr->correction, + ~csum_unfold(uhdr->check))); + if (!uhdr->check) + uhdr->check = CSUM_MANGLED_0; + + skb->ip_summed = CHECKSUM_NONE; +} + /** * ptp_msg_is_sync - Evaluates whether the given skb is a PTP Sync message * @skb: packet buffer @@ -166,5 +233,11 @@ static inline bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type) { return false; } + +static inline +void ptp_header_update_correction(struct sk_buff *skb, unsigned int type, + struct ptp_header *hdr, s64 correction) +{ +} #endif #endif /* _PTP_CLASSIFY_H_ */ -- cgit v1.2.3 From 90188fff655d8efad79acdf60c3012ffcbbef716 Mon Sep 17 00:00:00 2001 From: Christian Eggers Date: Tue, 10 Jan 2023 14:19:24 +0530 Subject: 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: Christian Eggers Co-developed-by: Arun Ramadoss Signed-off-by: Arun Ramadoss Reviewed-by: Vladimir Oltean Signed-off-by: David S. Miller --- include/linux/dsa/ksz_common.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h index d2a54161be97..a256b08d837d 100644 --- a/include/linux/dsa/ksz_common.h +++ b/include/linux/dsa/ksz_common.h @@ -9,10 +9,31 @@ #include +/* 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) { -- cgit v1.2.3 From ab32f56a4100f879c5064b45c7657bb4be175ac3 Mon Sep 17 00:00:00 2001 From: Christian Eggers Date: Tue, 10 Jan 2023 14:19:25 +0530 Subject: net: dsa: microchip: ptp: add packet transmission timestamping This patch adds the routines for transmission of ptp packets. When the ptp pdelay_req packet to be transmitted, it uses the deferred xmit worker to schedule the packets. During irq_setup, interrupt for Sync, Pdelay_req and Pdelay_rsp are enabled. So interrupt is triggered for all three packets. But for p2p1step, we require only time stamp of Pdelay_req packet. Hence to avoid posting of the completion from ISR routine for Sync and Pdelay_resp packets, ts_en flag is introduced. This controls which packets need to processed for timestamp. After the packet is transmitted, ISR is triggered. The time at which packet transmitted is recorded to separate register. This value is reconstructed to absolute time and posted to the user application through socket error queue. Signed-off-by: Christian Eggers Co-developed-by: Arun Ramadoss Signed-off-by: Arun Ramadoss Reviewed-by: Vladimir Oltean Signed-off-by: David S. Miller --- include/linux/dsa/ksz_common.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h index a256b08d837d..b91beab5e138 100644 --- a/include/linux/dsa/ksz_common.h +++ b/include/linux/dsa/ksz_common.h @@ -23,11 +23,19 @@ static inline ktime_t ksz_decode_tstamp(u32 tstamp) return ns_to_ktime(ns); } +struct ksz_deferred_xmit_work { + struct dsa_port *dp; + struct sk_buff *skb; + struct kthread_work work; +}; + struct ksz_tagger_data { + void (*xmit_work_fn)(struct kthread_work *work); void (*hwtstamp_set_state)(struct dsa_switch *ds, bool on); }; struct ksz_skb_cb { + struct sk_buff *clone; u32 tstamp; }; -- cgit v1.2.3 From a32190b154bde4a3bf2fddb9367aec49be09b15d Mon Sep 17 00:00:00 2001 From: Christian Eggers Date: Tue, 10 Jan 2023 14:19:26 +0530 Subject: net: dsa: microchip: ptp: move pdelay_rsp correction field to tail tag For PDelay_Resp messages we will likely have a negative value in the correction field. The switch hardware cannot correctly update such values (produces an off by one error in the UDP checksum), so it must be moved to the time stamp field in the tail tag. Format of the correction field is 48 bit ns + 16 bit fractional ns. After updating the correction field, clone is no longer required hence it is freed. Signed-off-by: Christian Eggers Co-developed-by: Arun Ramadoss Signed-off-by: Arun Ramadoss Signed-off-by: David S. Miller --- include/linux/dsa/ksz_common.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h index b91beab5e138..576a99ca698d 100644 --- a/include/linux/dsa/ksz_common.h +++ b/include/linux/dsa/ksz_common.h @@ -36,6 +36,8 @@ struct ksz_tagger_data { struct ksz_skb_cb { struct sk_buff *clone; + unsigned int ptp_type; + bool update_correction; u32 tstamp; }; -- cgit v1.2.3