[PATCH v1 0/2] ptp: Add generic header parsing function

[PATCH v1 0/2] ptp: Add generic header parsing function

[Kurt Kanzenbach]

Hi,

in order to reduce code duplication in the ptp code of DSA drivers, move the
header parsing function to ptp_classify. This way the Marvell and the hellcreek
drivers can share the same implementation. And probably more drivers can benefit
from it. Implemented as discussed [1] [2].

@DSA maintainers: Please, have a look the Marvell code. I don't have hardware to
test it. I've tested this series only on the Hirschmann switch.

Thanks,
Kurt

[1] - https://lkml.kernel.org/netdev/20200713140112.GB27934@hoboy/
[2] - https://lkml.kernel.org/netdev/20200720142146.GB16001@hoboy/

Kurt Kanzenbach (2):
  ptp: Add generic ptp v2 header parsing function
  net: dsa: mv88e6xxx: Use generic ptp header parsing function

 drivers/net/dsa/mv88e6xxx/Kconfig    |  1 +
 drivers/net/dsa/mv88e6xxx/hwtstamp.c | 59 ++++++----------------------
 include/linux/ptp_classify.h         | 38 ++++++++++++++++++
 net/core/ptp_classifier.c            | 30 ++++++++++++++
 4 files changed, 82 insertions(+), 46 deletions(-)

-- 
2.20.1

[PATCH v1 1/2] ptp: Add generic ptp v2 header parsing function

[Kurt Kanzenbach]

Reason: A lot of the ptp drivers - which implement hardware time stamping - need
specific fields such as the sequence id from the ptp v2 header. Currently all
drivers implement that themselves.

Introduce a generic function to retrieve a pointer to the start of the ptp v2
header.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
---
 include/linux/ptp_classify.h | 38 ++++++++++++++++++++++++++++++++++++
 net/core/ptp_classifier.c    | 30 ++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h
index dd00fa41f7e7..3370f402a503 100644
--- a/include/linux/ptp_classify.h
+++ b/include/linux/ptp_classify.h
@@ -44,6 +44,30 @@
 #define OFF_IHL		14
 #define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2)
 
+struct clock_identity {
+	u8 id[8];
+} __packed;
+
+struct port_identity {
+	struct clock_identity	clock_identity;
+	__be16			port_number;
+} __packed;
+
+struct ptp_header {
+	u8			tsmt;  /* transportSpecific | messageType */
+	u8			ver;   /* reserved          | versionPTP  */
+	__be16			message_length;
+	u8			domain_number;
+	u8			reserved1;
+	u8			flag_field[2];
+	__be64			correction;
+	__be32			reserved2;
+	struct port_identity	source_port_identity;
+	__be16			sequence_id;
+	u8			control;
+	u8			log_message_interval;
+} __packed;
+
 #if defined(CONFIG_NET_PTP_CLASSIFY)
 /**
  * ptp_classify_raw - classify a PTP packet
@@ -57,6 +81,15 @@
  */
 unsigned int ptp_classify_raw(const struct sk_buff *skb);
 
+/**
+ * ptp_parse_header - Get pointer to the PTP v2 header
+ * @skb: packet buffer
+ * @type: type of the packet (see ptp_classify_raw())
+ *
+ * Return: Pointer to the ptp v2 header or NULL if not found
+ */
+struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type);
+
 void __init ptp_classifier_init(void);
 #else
 static inline void ptp_classifier_init(void)
@@ -66,5 +99,10 @@ static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
 {
 	return PTP_CLASS_NONE;
 }
+static struct ptp_header *ptp_parse_header(struct sk_buff *skb,
+					   unsigned int type)
+{
+	return NULL;
+}
 #endif
 #endif /* _PTP_CLASSIFY_H_ */
diff --git a/net/core/ptp_classifier.c b/net/core/ptp_classifier.c
index d964a5147f22..dc12338bf3cd 100644
--- a/net/core/ptp_classifier.c
+++ b/net/core/ptp_classifier.c
@@ -107,6 +107,36 @@ unsigned int ptp_classify_raw(const struct sk_buff *skb)
 }
 EXPORT_SYMBOL_GPL(ptp_classify_raw);
 
+struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type)
+{
+	u8 *data = skb_mac_header(skb);
+	unsigned int offset = 0;
+
+	if (type & PTP_CLASS_VLAN)
+		offset += VLAN_HLEN;
+
+	switch (type & PTP_CLASS_PMASK) {
+	case PTP_CLASS_IPV4:
+		offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
+		break;
+	case PTP_CLASS_IPV6:
+		offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
+		break;
+	case PTP_CLASS_L2:
+		offset += ETH_HLEN;
+		break;
+	default:
+		return NULL;
+	}
+
+	/* Ensure that the entire header is present in this packet. */
+	if (skb->len + ETH_HLEN < offset + sizeof(struct ptp_header))
+		return NULL;
+
+	return (struct ptp_header *)(data + offset);
+}
+EXPORT_SYMBOL_GPL(ptp_parse_header);
+
 void __init ptp_classifier_init(void)
 {
 	static struct sock_filter ptp_filter[] __initdata = {
-- 
2.20.1

Re: [PATCH v1 1/2] ptp: Add generic ptp v2 header parsing function

[Kurt Kanzenbach]

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On Thu Jul 23 2020, Kurt Kanzenbach wrote:
> +static struct ptp_header *ptp_parse_header(struct sk_buff *skb,
> +					   unsigned int type)
> +{
> +	return NULL;
> +}
>  #endif

That should be static inline ofc.

Thanks,
Kurt

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[PATCH v1 2/2] net: dsa: mv88e6xxx: Use generic ptp header parsing function

[Kurt Kanzenbach]

That function is now available within ptp classify. So use it.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
---
 drivers/net/dsa/mv88e6xxx/Kconfig    |  1 +
 drivers/net/dsa/mv88e6xxx/hwtstamp.c | 59 ++++++----------------------
 2 files changed, 14 insertions(+), 46 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/Kconfig b/drivers/net/dsa/mv88e6xxx/Kconfig
index 51185e4d7d15..349621fe71cf 100644
--- a/drivers/net/dsa/mv88e6xxx/Kconfig
+++ b/drivers/net/dsa/mv88e6xxx/Kconfig
@@ -26,6 +26,7 @@ config NET_DSA_MV88E6XXX_PTP
 	depends on NET_DSA_MV88E6XXX_GLOBAL2
 	depends on PTP_1588_CLOCK
 	imply NETWORK_PHY_TIMESTAMPING
+	select NET_PTP_CLASSIFY
 	help
 	  Say Y to enable PTP hardware timestamping on Marvell 88E6xxx switch
 	  chips that support it.
diff --git a/drivers/net/dsa/mv88e6xxx/hwtstamp.c b/drivers/net/dsa/mv88e6xxx/hwtstamp.c
index a4c488b12e8f..094d17a1d037 100644
--- a/drivers/net/dsa/mv88e6xxx/hwtstamp.c
+++ b/drivers/net/dsa/mv88e6xxx/hwtstamp.c
@@ -211,49 +211,20 @@ int mv88e6xxx_port_hwtstamp_get(struct dsa_switch *ds, int port,
 		-EFAULT : 0;
 }
 
-/* Get the start of the PTP header in this skb */
-static u8 *parse_ptp_header(struct sk_buff *skb, unsigned int type)
-{
-	u8 *data = skb_mac_header(skb);
-	unsigned int offset = 0;
-
-	if (type & PTP_CLASS_VLAN)
-		offset += VLAN_HLEN;
-
-	switch (type & PTP_CLASS_PMASK) {
-	case PTP_CLASS_IPV4:
-		offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
-		break;
-	case PTP_CLASS_IPV6:
-		offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
-		break;
-	case PTP_CLASS_L2:
-		offset += ETH_HLEN;
-		break;
-	default:
-		return NULL;
-	}
-
-	/* Ensure that the entire header is present in this packet. */
-	if (skb->len + ETH_HLEN < offset + 34)
-		return NULL;
-
-	return data + offset;
-}
-
 /* Returns a pointer to the PTP header if the caller should time stamp,
  * or NULL if the caller should not.
  */
-static u8 *mv88e6xxx_should_tstamp(struct mv88e6xxx_chip *chip, int port,
-				   struct sk_buff *skb, unsigned int type)
+static struct ptp_header *mv88e6xxx_should_tstamp(struct mv88e6xxx_chip *chip,
+						  int port, struct sk_buff *skb,
+						  unsigned int type)
 {
 	struct mv88e6xxx_port_hwtstamp *ps = &chip->port_hwtstamp[port];
-	u8 *hdr;
+	struct ptp_header *hdr;
 
 	if (!chip->info->ptp_support)
 		return NULL;
 
-	hdr = parse_ptp_header(skb, type);
+	hdr = ptp_parse_header(skb, type);
 	if (!hdr)
 		return NULL;
 
@@ -275,12 +246,11 @@ static int mv88e6xxx_ts_valid(u16 status)
 static int seq_match(struct sk_buff *skb, u16 ts_seqid)
 {
 	unsigned int type = SKB_PTP_TYPE(skb);
-	u8 *hdr = parse_ptp_header(skb, type);
-	__be16 *seqid;
+	struct ptp_header *hdr;
 
-	seqid = (__be16 *)(hdr + OFF_PTP_SEQUENCE_ID);
+	hdr = ptp_parse_header(skb, type);
 
-	return ts_seqid == ntohs(*seqid);
+	return ts_seqid == ntohs(hdr->sequence_id);
 }
 
 static void mv88e6xxx_get_rxts(struct mv88e6xxx_chip *chip,
@@ -357,9 +327,9 @@ static void mv88e6xxx_rxtstamp_work(struct mv88e6xxx_chip *chip,
 				   &ps->rx_queue2);
 }
 
-static int is_pdelay_resp(u8 *msgtype)
+static int is_pdelay_resp(const struct ptp_header *hdr)
 {
-	return (*msgtype & 0xf) == 3;
+	return (hdr->tsmt & 0xf) == 3;
 }
 
 bool mv88e6xxx_port_rxtstamp(struct dsa_switch *ds, int port,
@@ -367,7 +337,7 @@ bool mv88e6xxx_port_rxtstamp(struct dsa_switch *ds, int port,
 {
 	struct mv88e6xxx_port_hwtstamp *ps;
 	struct mv88e6xxx_chip *chip;
-	u8 *hdr;
+	struct ptp_header *hdr;
 
 	chip = ds->priv;
 	ps = &chip->port_hwtstamp[port];
@@ -503,8 +473,7 @@ bool mv88e6xxx_port_txtstamp(struct dsa_switch *ds, int port,
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	struct mv88e6xxx_port_hwtstamp *ps = &chip->port_hwtstamp[port];
-	__be16 *seq_ptr;
-	u8 *hdr;
+	struct ptp_header *hdr;
 
 	if (!(skb_shinfo(clone)->tx_flags & SKBTX_HW_TSTAMP))
 		return false;
@@ -513,15 +482,13 @@ bool mv88e6xxx_port_txtstamp(struct dsa_switch *ds, int port,
 	if (!hdr)
 		return false;
 
-	seq_ptr = (__be16 *)(hdr + OFF_PTP_SEQUENCE_ID);
-
 	if (test_and_set_bit_lock(MV88E6XXX_HWTSTAMP_TX_IN_PROGRESS,
 				  &ps->state))
 		return false;
 
 	ps->tx_skb = clone;
 	ps->tx_tstamp_start = jiffies;
-	ps->tx_seq_id = be16_to_cpup(seq_ptr);
+	ps->tx_seq_id = be16_to_cpu(hdr->sequence_id);
 
 	ptp_schedule_worker(chip->ptp_clock, 0);
 	return true;
-- 
2.20.1

Re: [PATCH v1 2/2] net: dsa: mv88e6xxx: Use generic ptp header parsing function

[Richard Cochran]

On Thu, Jul 23, 2020 at 09:49:46AM +0200, Kurt Kanzenbach wrote:
> @@ -26,6 +26,7 @@ config NET_DSA_MV88E6XXX_PTP
>  	depends on NET_DSA_MV88E6XXX_GLOBAL2
>  	depends on PTP_1588_CLOCK
>  	imply NETWORK_PHY_TIMESTAMPING
> +	select NET_PTP_CLASSIFY

Hm, PTP_1588_CLOCK already selects NET_PTP_CLASSIFY,

  config PTP_1588_CLOCK
	tristate "PTP clock support"
	depends on NET && POSIX_TIMERS
	select PPS
	select NET_PTP_CLASSIFY

and so I expect that the 'select' in NET_DSA_MV88E6XXX_PTP isn't
needed.  What am I missing?

Thanks,
Richard

Re: [PATCH v1 2/2] net: dsa: mv88e6xxx: Use generic ptp header parsing function

[Kurt Kanzenbach]

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On Thu Jul 23 2020, Richard Cochran wrote:
> On Thu, Jul 23, 2020 at 09:49:46AM +0200, Kurt Kanzenbach wrote:
>> @@ -26,6 +26,7 @@ config NET_DSA_MV88E6XXX_PTP
>>  	depends on NET_DSA_MV88E6XXX_GLOBAL2
>>  	depends on PTP_1588_CLOCK
>>  	imply NETWORK_PHY_TIMESTAMPING
>> +	select NET_PTP_CLASSIFY
>
> Hm, PTP_1588_CLOCK already selects NET_PTP_CLASSIFY,
>
>   config PTP_1588_CLOCK
> 	tristate "PTP clock support"
> 	depends on NET && POSIX_TIMERS
> 	select PPS
> 	select NET_PTP_CLASSIFY
>
> and so I expect that the 'select' in NET_DSA_MV88E6XXX_PTP isn't
> needed.  What am I missing?

OK, didn't noticed that.

Thanks,
Kurt

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Re: [PATCH v1 0/2] ptp: Add generic header parsing function

[Richard Cochran]

Kurt,

On Thu, Jul 23, 2020 at 09:49:44AM +0200, Kurt Kanzenbach wrote:
> in order to reduce code duplication in the ptp code of DSA drivers, move the
> header parsing function to ptp_classify. This way the Marvell and the hellcreek
> drivers can share the same implementation. And probably more drivers can benefit
> from it. Implemented as discussed [1] [2].

This looks good.  I made a list of drivers that can possibily use this helper.

Finding symbol: PTP_CLASS_PMASK

*** drivers/net/dsa/mv88e6xxx/hwtstamp.c:
parse_ptp_header[223]          switch (type & PTP_CLASS_PMASK) {

*** drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c:
mlxsw_sp_ptp_parse[335]        switch (ptp_class & PTP_CLASS_PMASK) {

*** drivers/net/ethernet/ti/am65-cpts.c:
am65_skb_get_mtype_seqid[761]  switch (ptp_class & PTP_CLASS_PMASK) {

*** drivers/net/ethernet/ti/cpts.c:
cpts_skb_get_mtype_seqid[459]  switch (ptp_class & PTP_CLASS_PMASK) {

*** drivers/net/phy/dp83640.c:
match[815]                     switch (type & PTP_CLASS_PMASK) {
is_sync[990]                   switch (type & PTP_CLASS_PMASK) {

*** drivers/ptp/ptp_ines.c:
ines_match[457]                switch (ptp_class & PTP_CLASS_PMASK) {
is_sync_pdelay_resp[703]       switch (type & PTP_CLASS_PMASK) {

> @DSA maintainers: Please, have a look the Marvell code. I don't have hardware to
> test it. I've tested this series only on the Hirschmann switch.

I'll test the marvell switch with your change and let you know...

Thanks,
Richard

Re: [PATCH v1 0/2] ptp: Add generic header parsing function

[Kurt Kanzenbach]

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On Thu Jul 23 2020, Richard Cochran wrote:
> Kurt,
>
> On Thu, Jul 23, 2020 at 09:49:44AM +0200, Kurt Kanzenbach wrote:
>> in order to reduce code duplication in the ptp code of DSA drivers, move the
>> header parsing function to ptp_classify. This way the Marvell and the hellcreek
>> drivers can share the same implementation. And probably more drivers can benefit
>> from it. Implemented as discussed [1] [2].
>
> This looks good.  I made a list of drivers that can possibily use this helper.
>
> Finding symbol: PTP_CLASS_PMASK
>
> *** drivers/net/dsa/mv88e6xxx/hwtstamp.c:
> parse_ptp_header[223]          switch (type & PTP_CLASS_PMASK) {

Sure, done already (see patch 2).

>
> *** drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c:
> mlxsw_sp_ptp_parse[335]        switch (ptp_class & PTP_CLASS_PMASK) {

Works ootb.

>
> *** drivers/net/ethernet/ti/am65-cpts.c:
> am65_skb_get_mtype_seqid[761]  switch (ptp_class & PTP_CLASS_PMASK) {
>
> *** drivers/net/ethernet/ti/cpts.c:
> cpts_skb_get_mtype_seqid[459]  switch (ptp_class & PTP_CLASS_PMASK) {
>
> *** drivers/net/phy/dp83640.c:
> match[815]                     switch (type & PTP_CLASS_PMASK) {
> is_sync[990]                   switch (type & PTP_CLASS_PMASK) {

These three drivers also deal with ptp v1 and they need access to the
message type. However, the message type is located at a different offset
depending on the ptp version. They all do:

|if (unlikely(ptp_class & PTP_CLASS_V1))
|	msgtype = data + offset + OFF_PTP_CONTROL;
|else
|	msgtype = data + offset;

Maybe we can put that in a helper function, too?

|static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, unsigned int type)
|{
|	u8 msg;
|
|	if (unlikely(type & PTP_CLASS_V1))
|		/* msg type is located @ offset 20 for ptp v1 */ 
|		msg = hdr->source_port_identity.clock_identity.id[0];
|	else
|		msg = hdr->tsmt & 0x0f;
|
|	return msg;
|}

What do you think about it?

>
> *** drivers/ptp/ptp_ines.c:
> ines_match[457]                switch (ptp_class & PTP_CLASS_PMASK) {
> is_sync_pdelay_resp[703]       switch (type & PTP_CLASS_PMASK) {

Works ootb.

>
>> @DSA maintainers: Please, have a look the Marvell code. I don't have hardware to
>> test it. I've tested this series only on the Hirschmann switch.
>
> I'll test the marvell switch with your change and let you know...

Great.

Thanks,
Kurt

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Re: [PATCH v1 0/2] ptp: Add generic header parsing function

[Richard Cochran]

On Fri, Jul 24, 2020 at 08:25:59AM +0200, Kurt Kanzenbach wrote:
> These three drivers also deal with ptp v1 and they need access to the
> message type. However, the message type is located at a different offset
> depending on the ptp version. They all do:
> 
> |if (unlikely(ptp_class & PTP_CLASS_V1))
> |	msgtype = data + offset + OFF_PTP_CONTROL;
> |else
> |	msgtype = data + offset;
> 
> Maybe we can put that in a helper function, too?

Yes, please.

> |static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, unsigned int type)
> |{
> |	u8 msg;
> |
> |	if (unlikely(type & PTP_CLASS_V1))
> |		/* msg type is located @ offset 20 for ptp v1 */ 
> |		msg = hdr->source_port_identity.clock_identity.id[0];
> |	else
> |		msg = hdr->tsmt & 0x0f;
> |
> |	return msg;
> |}
> 
> What do you think about it?

Looks good.

I can also test the dp83640.  Maybe you could test the cpts on a bbb?


Thanks,
Richard

Re: [PATCH v1 0/2] ptp: Add generic header parsing function

[Kurt Kanzenbach]

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On Fri Jul 24 2020, Richard Cochran wrote:
> On Fri, Jul 24, 2020 at 08:25:59AM +0200, Kurt Kanzenbach wrote:
>> |static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, unsigned int type)
>> |{
>> |	u8 msg;
>> |
>> |	if (unlikely(type & PTP_CLASS_V1))
>> |		/* msg type is located @ offset 20 for ptp v1 */ 
>> |		msg = hdr->source_port_identity.clock_identity.id[0];
>> |	else
>> |		msg = hdr->tsmt & 0x0f;
>> |
>> |	return msg;
>> |}
>> 
>> What do you think about it?
>
> Looks good.

OK, I'll add it.

>
> I can also test the dp83640.  Maybe you could test the cpts on a bbb?

Most likely, yes.

Thanks,
Kurt

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