OSDN Git Service

mlxsw: spectrum: PTP: Support timestamping on Spectrum-1
authorPetr Machata <petrm@mellanox.com>
Sun, 30 Jun 2019 06:04:56 +0000 (09:04 +0300)
committerDavid S. Miller <davem@davemloft.net>
Tue, 2 Jul 2019 01:58:34 +0000 (18:58 -0700)
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: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/mellanox/mlxsw/Kconfig
drivers/net/ethernet/mellanox/mlxsw/spectrum.c
drivers/net/ethernet/mellanox/mlxsw/spectrum.h
drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.h
drivers/net/ethernet/mellanox/mlxsw/trap.h

index b5d64ae..06c8034 100644 (file)
@@ -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
index 6cb7aea..bd405c5 100644 (file)
@@ -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)
index 7e18081..7f8427c 100644 (file)
@@ -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 {
index 1eb6eef..e87066f 100644 (file)
@@ -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)
index 0f66e63..40c9e82 100644 (file)
@@ -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 *
index f05b7ff..19202bd 100644 (file)
@@ -78,6 +78,10 @@ enum {
 enum mlxsw_event_trap_id {
        /* Port Up/Down event generated by hardware */
        MLXSW_TRAP_ID_PUDE = 0x8,
+       /* PTP Ingress FIFO has a new entry */
+       MLXSW_TRAP_ID_PTP_ING_FIFO = 0x2D,
+       /* PTP Egress FIFO has a new entry */
+       MLXSW_TRAP_ID_PTP_EGR_FIFO = 0x2E,
 };
 
 #endif /* _MLXSW_TRAP_H */