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Commit d92e4e6e authored by Petr Machata's avatar Petr Machata Committed by David S. Miller
Browse files

mlxsw: spectrum: PTP: Support timestamping on Spectrum-1 



On Spectrum-1, timestamps arrive through a pair of dedicated events:
MLXSW_TRAP_ID_PTP_ING_FIFO and _EGR_FIFO. The payload delivered with
those traps is contents of the timestamp FIFO at a given port in a given
direction. Add a Spectrum-1-specific handler for these two events which
decodes the timestamps and forwards them to the PTP module.

Add a function that parses a packet, dispatching to ptp_classify_raw(),
and decodes PTP message type, domain number, and sequence ID. Add a new
mlxsw dependency on the PTP classifier.

Add helpers that can store and retrieve unmatched timestamps and SKBs to
the hash table added in a preceding patch.

Add the matching code itself: upon arrival of a timestamp or a packet,
look up the corresponding unmatched entry, and match it up. If there is
none, add a new unmatched entry. This logic is the same on ingress as on
egress.

Packets and timestamps that never matched need to be eventually disposed
of. A garbage collector added in a follow-up patch will take care of
that. Since currently all this code is turned off, no crud will
accumulate in the hash table.

Signed-off-by: default avatarPetr Machata <petrm@mellanox.com>
Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 89e602ee

drivers/net/ethernet/mellanox/mlxsw/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ config MLXSW_SPECTRUM 
	select OBJAGG

	select MLXFW

	imply PTP_1588_CLOCK

	select NET_PTP_CLASSIFY if PTP_1588_CLOCK

	default m

	---help---

	  This driver supports Mellanox Technologies Spectrum Ethernet

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

+43 −0
Original line number Diff line number Diff line
@@ -3970,6 +3970,46 @@ static void mlxsw_sp_pude_event_func(const struct mlxsw_reg_info *reg, 
	}

}



static void mlxsw_sp1_ptp_fifo_event_func(struct mlxsw_sp *mlxsw_sp,

					  char *mtpptr_pl, bool ingress)

{

	u8 local_port;

	u8 num_rec;

	int i;



	local_port = mlxsw_reg_mtpptr_local_port_get(mtpptr_pl);

	num_rec = mlxsw_reg_mtpptr_num_rec_get(mtpptr_pl);

	for (i = 0; i < num_rec; i++) {

		u8 domain_number;

		u8 message_type;

		u16 sequence_id;

		u64 timestamp;



		mlxsw_reg_mtpptr_unpack(mtpptr_pl, i, &message_type,

					&domain_number, &sequence_id,

					&timestamp);

		mlxsw_sp1_ptp_got_timestamp(mlxsw_sp, ingress, local_port,

					    message_type, domain_number,

					    sequence_id, timestamp);

	}

}



static void mlxsw_sp1_ptp_ing_fifo_event_func(const struct mlxsw_reg_info *reg,

					      char *mtpptr_pl, void *priv)

{

	struct mlxsw_sp *mlxsw_sp = priv;



	mlxsw_sp1_ptp_fifo_event_func(mlxsw_sp, mtpptr_pl, true);

}



static void mlxsw_sp1_ptp_egr_fifo_event_func(const struct mlxsw_reg_info *reg,

					      char *mtpptr_pl, void *priv)

{

	struct mlxsw_sp *mlxsw_sp = priv;



	mlxsw_sp1_ptp_fifo_event_func(mlxsw_sp, mtpptr_pl, false);

}



void mlxsw_sp_rx_listener_no_mark_func(struct sk_buff *skb,

				       u8 local_port, void *priv)

{
@@ -4151,6 +4191,9 @@ static const struct mlxsw_listener mlxsw_sp_listener[] = { 
};



static const struct mlxsw_listener mlxsw_sp1_listener[] = {

	/* Events */

	MLXSW_EVENTL(mlxsw_sp1_ptp_egr_fifo_event_func, PTP_EGR_FIFO, SP_PTP0),

	MLXSW_EVENTL(mlxsw_sp1_ptp_ing_fifo_event_func, PTP_ING_FIFO, SP_PTP0),

};



static int mlxsw_sp_cpu_policers_set(struct mlxsw_core *mlxsw_core)

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

+5 −0
Original line number Diff line number Diff line
@@ -266,6 +266,11 @@ struct mlxsw_sp_port { 
	unsigned acl_rule_count;

	struct mlxsw_sp_acl_block *ing_acl_block;

	struct mlxsw_sp_acl_block *eg_acl_block;

	struct {

		struct hwtstamp_config hwtstamp_config;

		u16 ing_types;

		u16 egr_types;

	} ptp;

};



struct mlxsw_sp_port_type_speed_ops {

drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c

+322 −2
Original line number Diff line number Diff line
@@ -6,6 +6,10 @@ 
#include <linux/timecounter.h>

#include <linux/spinlock.h>

#include <linux/device.h>

#include <linux/rhashtable.h>

#include <linux/ptp_classify.h>

#include <linux/if_ether.h>

#include <linux/if_vlan.h>



#include "spectrum.h"

#include "spectrum_ptp.h"
@@ -293,6 +297,166 @@ void mlxsw_sp1_ptp_clock_fini(struct mlxsw_sp_ptp_clock *clock) 
	kfree(clock);

}



static int mlxsw_sp_ptp_parse(struct sk_buff *skb,

			      u8 *p_domain_number,

			      u8 *p_message_type,

			      u16 *p_sequence_id)

{

	unsigned int offset = 0;

	unsigned int ptp_class;

	u8 *data;



	data = skb_mac_header(skb);

	ptp_class = ptp_classify_raw(skb);



	switch (ptp_class & PTP_CLASS_VMASK) {

	case PTP_CLASS_V1:

	case PTP_CLASS_V2:

		break;

	default:

		return -ERANGE;

	}



	if (ptp_class & PTP_CLASS_VLAN)

		offset += VLAN_HLEN;



	switch (ptp_class & 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 -ERANGE;

	}



	/* PTP header is 34 bytes. */

	if (skb->len < offset + 34)

		return -EINVAL;



	*p_message_type = data[offset] & 0x0f;

	*p_domain_number = data[offset + 4];

	*p_sequence_id = (u16)(data[offset + 30]) << 8 | data[offset + 31];

	return 0;

}



/* Returns NULL on successful insertion, a pointer on conflict, or an ERR_PTR on

 * error.

 */

static struct mlxsw_sp1_ptp_unmatched *

mlxsw_sp1_ptp_unmatched_save(struct mlxsw_sp *mlxsw_sp,

			     struct mlxsw_sp1_ptp_key key,

			     struct sk_buff *skb,

			     u64 timestamp)

{

	struct mlxsw_sp_ptp_state *ptp_state = mlxsw_sp->ptp_state;

	struct mlxsw_sp1_ptp_unmatched *unmatched;

	struct mlxsw_sp1_ptp_unmatched *conflict;



	unmatched = kzalloc(sizeof(*unmatched), GFP_ATOMIC);

	if (!unmatched)

		return ERR_PTR(-ENOMEM);



	unmatched->key = key;

	unmatched->skb = skb;

	unmatched->timestamp = timestamp;



	conflict = rhashtable_lookup_get_insert_fast(&ptp_state->unmatched_ht,

					    &unmatched->ht_node,

					    mlxsw_sp1_ptp_unmatched_ht_params);

	if (conflict)

		kfree(unmatched);



	return conflict;

}



static struct mlxsw_sp1_ptp_unmatched *

mlxsw_sp1_ptp_unmatched_lookup(struct mlxsw_sp *mlxsw_sp,

			       struct mlxsw_sp1_ptp_key key)

{

	return rhashtable_lookup(&mlxsw_sp->ptp_state->unmatched_ht, &key,

				 mlxsw_sp1_ptp_unmatched_ht_params);

}



static int

mlxsw_sp1_ptp_unmatched_remove(struct mlxsw_sp *mlxsw_sp,

			       struct mlxsw_sp1_ptp_unmatched *unmatched)

{

	return rhashtable_remove_fast(&mlxsw_sp->ptp_state->unmatched_ht,

				      &unmatched->ht_node,

				      mlxsw_sp1_ptp_unmatched_ht_params);

}



/* This function is called in the following scenarios:

 *

 * 1) When a packet is matched with its timestamp.

 * 2) In several situation when it is necessary to immediately pass on

 *    an SKB without a timestamp.

 */

static void mlxsw_sp1_ptp_packet_finish(struct mlxsw_sp *mlxsw_sp,

					struct sk_buff *skb, u8 local_port,

					bool ingress,

					struct skb_shared_hwtstamps *hwtstamps)

{

	struct mlxsw_sp_port *mlxsw_sp_port;



	/* Between capturing the packet and finishing it, there is a window of

	 * opportunity for the originating port to go away (e.g. due to a

	 * split). Also make sure the SKB device reference is still valid.

	 */

	mlxsw_sp_port = mlxsw_sp->ports[local_port];

	if (!mlxsw_sp_port && (!skb->dev || skb->dev == mlxsw_sp_port->dev)) {

		dev_kfree_skb_any(skb);

		return;

	}



	if (ingress) {

		if (hwtstamps)

			*skb_hwtstamps(skb) = *hwtstamps;

		mlxsw_sp_rx_listener_no_mark_func(skb, local_port, mlxsw_sp);

	} else {

		/* skb_tstamp_tx() allows hwtstamps to be NULL. */

		skb_tstamp_tx(skb, hwtstamps);

		dev_kfree_skb_any(skb);

	}

}



static void mlxsw_sp1_packet_timestamp(struct mlxsw_sp *mlxsw_sp,

				       struct mlxsw_sp1_ptp_key key,

				       struct sk_buff *skb,

				       u64 timestamp)

{

	struct skb_shared_hwtstamps hwtstamps;

	u64 nsec;



	spin_lock_bh(&mlxsw_sp->clock->lock);

	nsec = timecounter_cyc2time(&mlxsw_sp->clock->tc, timestamp);

	spin_unlock_bh(&mlxsw_sp->clock->lock);



	hwtstamps.hwtstamp = ns_to_ktime(nsec);

	mlxsw_sp1_ptp_packet_finish(mlxsw_sp, skb,

				    key.local_port, key.ingress, &hwtstamps);

}



static void

mlxsw_sp1_ptp_unmatched_finish(struct mlxsw_sp *mlxsw_sp,

			       struct mlxsw_sp1_ptp_unmatched *unmatched)

{

	if (unmatched->skb && unmatched->timestamp)

		mlxsw_sp1_packet_timestamp(mlxsw_sp, unmatched->key,

					   unmatched->skb,

					   unmatched->timestamp);

	else if (unmatched->skb)

		mlxsw_sp1_ptp_packet_finish(mlxsw_sp, unmatched->skb,

					    unmatched->key.local_port,

					    unmatched->key.ingress, NULL);

	kfree_rcu(unmatched, rcu);

}



static void mlxsw_sp1_ptp_unmatched_free_fn(void *ptr, void *arg)

{

	struct mlxsw_sp1_ptp_unmatched *unmatched = ptr;
@@ -305,16 +469,172 @@ static void mlxsw_sp1_ptp_unmatched_free_fn(void *ptr, void *arg) 
	kfree_rcu(unmatched, rcu);

}



static void mlxsw_sp1_ptp_got_piece(struct mlxsw_sp *mlxsw_sp,

				    struct mlxsw_sp1_ptp_key key,

				    struct sk_buff *skb, u64 timestamp)

{

	struct mlxsw_sp1_ptp_unmatched *unmatched, *conflict;

	int err;



	rcu_read_lock();



	unmatched = mlxsw_sp1_ptp_unmatched_lookup(mlxsw_sp, key);



	spin_lock(&mlxsw_sp->ptp_state->unmatched_lock);



	if (unmatched) {

		/* There was an unmatched entry when we looked, but it may have

		 * been removed before we took the lock.

		 */

		err = mlxsw_sp1_ptp_unmatched_remove(mlxsw_sp, unmatched);

		if (err)

			unmatched = NULL;

	}



	if (!unmatched) {

		/* We have no unmatched entry, but one may have been added after

		 * we looked, but before we took the lock.

		 */

		unmatched = mlxsw_sp1_ptp_unmatched_save(mlxsw_sp, key,

							 skb, timestamp);

		if (IS_ERR(unmatched)) {

			if (skb)

				mlxsw_sp1_ptp_packet_finish(mlxsw_sp, skb,

							    key.local_port,

							    key.ingress, NULL);

			unmatched = NULL;

		} else if (unmatched) {

			/* Save just told us, under lock, that the entry is

			 * there, so this has to work.

			 */

			err = mlxsw_sp1_ptp_unmatched_remove(mlxsw_sp,

							     unmatched);

			WARN_ON_ONCE(err);

		}

	}



	/* If unmatched is non-NULL here, it comes either from the lookup, or

	 * from the save attempt above. In either case the entry was removed

	 * from the hash table. If unmatched is NULL, a new unmatched entry was

	 * added to the hash table, and there was no conflict.

	 */



	if (skb && unmatched && unmatched->timestamp) {

		unmatched->skb = skb;

	} else if (timestamp && unmatched && unmatched->skb) {

		unmatched->timestamp = timestamp;

	} else if (unmatched) {

		/* unmatched holds an older entry of the same type: either an

		 * skb if we are handling skb, or a timestamp if we are handling

		 * timestamp. We can't match that up, so save what we have.

		 */

		conflict = mlxsw_sp1_ptp_unmatched_save(mlxsw_sp, key,

							skb, timestamp);

		if (IS_ERR(conflict)) {

			if (skb)

				mlxsw_sp1_ptp_packet_finish(mlxsw_sp, skb,

							    key.local_port,

							    key.ingress, NULL);

		} else {

			/* Above, we removed an object with this key from the

			 * hash table, under lock, so conflict can not be a

			 * valid pointer.

			 */

			WARN_ON_ONCE(conflict);

		}

	}



	spin_unlock(&mlxsw_sp->ptp_state->unmatched_lock);



	if (unmatched)

		mlxsw_sp1_ptp_unmatched_finish(mlxsw_sp, unmatched);



	rcu_read_unlock();

}



static void mlxsw_sp1_ptp_got_packet(struct mlxsw_sp *mlxsw_sp,

				     struct sk_buff *skb, u8 local_port,

				     bool ingress)

{

	struct mlxsw_sp_port *mlxsw_sp_port;

	struct mlxsw_sp1_ptp_key key;

	u8 types;

	int err;



	mlxsw_sp_port = mlxsw_sp->ports[local_port];

	if (!mlxsw_sp_port)

		goto immediate;



	types = ingress ? mlxsw_sp_port->ptp.ing_types :

			  mlxsw_sp_port->ptp.egr_types;

	if (!types)

		goto immediate;



	memset(&key, 0, sizeof(key));

	key.local_port = local_port;

	key.ingress = ingress;



	err = mlxsw_sp_ptp_parse(skb, &key.domain_number, &key.message_type,

				 &key.sequence_id);

	if (err)

		goto immediate;



	/* For packets whose timestamping was not enabled on this port, don't

	 * bother trying to match the timestamp.

	 */

	if (!((1 << key.message_type) & types))

		goto immediate;



	mlxsw_sp1_ptp_got_piece(mlxsw_sp, key, skb, 0);

	return;



immediate:

	mlxsw_sp1_ptp_packet_finish(mlxsw_sp, skb, local_port, ingress, NULL);

}



void mlxsw_sp1_ptp_got_timestamp(struct mlxsw_sp *mlxsw_sp, bool ingress,

				 u8 local_port, u8 message_type,

				 u8 domain_number, u16 sequence_id,

				 u64 timestamp)

{

	struct mlxsw_sp_port *mlxsw_sp_port;

	struct mlxsw_sp1_ptp_key key;

	u8 types;



	mlxsw_sp_port = mlxsw_sp->ports[local_port];

	if (!mlxsw_sp_port)

		return;



	types = ingress ? mlxsw_sp_port->ptp.ing_types :

			  mlxsw_sp_port->ptp.egr_types;



	/* For message types whose timestamping was not enabled on this port,

	 * don't bother with the timestamp.

	 */

	if (!((1 << message_type) & types))

		return;



	memset(&key, 0, sizeof(key));

	key.local_port = local_port;

	key.domain_number = domain_number;

	key.message_type = message_type;

	key.sequence_id = sequence_id;

	key.ingress = ingress;



	mlxsw_sp1_ptp_got_piece(mlxsw_sp, key, NULL, timestamp);

}



void mlxsw_sp1_ptp_receive(struct mlxsw_sp *mlxsw_sp, struct sk_buff *skb,

			   u8 local_port)

{

	mlxsw_sp_rx_listener_no_mark_func(skb, local_port, mlxsw_sp);

	skb_reset_mac_header(skb);

	mlxsw_sp1_ptp_got_packet(mlxsw_sp, skb, local_port, true);

}



void mlxsw_sp1_ptp_transmitted(struct mlxsw_sp *mlxsw_sp,

			       struct sk_buff *skb, u8 local_port)

{

	dev_kfree_skb_any(skb);

	mlxsw_sp1_ptp_got_packet(mlxsw_sp, skb, local_port, false);

}



struct mlxsw_sp_ptp_state *mlxsw_sp1_ptp_init(struct mlxsw_sp *mlxsw_sp)

drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.h

+13 −0
Original line number Diff line number Diff line
@@ -28,6 +28,11 @@ void mlxsw_sp1_ptp_receive(struct mlxsw_sp *mlxsw_sp, struct sk_buff *skb, 
void mlxsw_sp1_ptp_transmitted(struct mlxsw_sp *mlxsw_sp,

			       struct sk_buff *skb, u8 local_port);



void mlxsw_sp1_ptp_got_timestamp(struct mlxsw_sp *mlxsw_sp, bool ingress,

				 u8 local_port, u8 message_type,

				 u8 domain_number, u16 sequence_id,

				 u64 timestamp);



#else



static inline struct mlxsw_sp_ptp_clock *
@@ -62,6 +67,14 @@ static inline void mlxsw_sp1_ptp_transmitted(struct mlxsw_sp *mlxsw_sp, 
	dev_kfree_skb_any(skb);

}



static inline void

mlxsw_sp1_ptp_got_timestamp(struct mlxsw_sp *mlxsw_sp, bool ingress,

			    u8 local_port, u8 message_type,

			    u8 domain_number,

			    u16 sequence_id, u64 timestamp)

{

}



#endif



static inline struct mlxsw_sp_ptp_clock *