net/mlx5e: Add PTP Hardware Clock (PHC) support
Add a PHC support to the mlx5_en driver. Use reader/writer spinlocks to
protect the timecounter since every packet received needs to call
timecounter_cycle2time() when timestamping is enabled. This can become
a performance bottleneck with RSS and multiple receive queues if normal
spinlocks are used.
The driver has been tested with both Documentation/ptp/testptp and the
linuxptp project (http://linuxptp.sourceforge.net/) on a Mellanox
ConnectX-4 card.
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c b/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
index 49a8238..be65435 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
@@ -130,6 +130,89 @@
return copy_to_user(ifr->ifr_data, cfg, sizeof(*cfg)) ? -EFAULT : 0;
}
+static int mlx5e_ptp_settime(struct ptp_clock_info *ptp,
+ const struct timespec64 *ts)
+{
+ struct mlx5e_tstamp *tstamp = container_of(ptp, struct mlx5e_tstamp,
+ ptp_info);
+ u64 ns = timespec64_to_ns(ts);
+
+ write_lock(&tstamp->lock);
+ timecounter_init(&tstamp->clock, &tstamp->cycles, ns);
+ write_unlock(&tstamp->lock);
+
+ return 0;
+}
+
+static int mlx5e_ptp_gettime(struct ptp_clock_info *ptp,
+ struct timespec64 *ts)
+{
+ struct mlx5e_tstamp *tstamp = container_of(ptp, struct mlx5e_tstamp,
+ ptp_info);
+ u64 ns;
+
+ write_lock(&tstamp->lock);
+ ns = timecounter_read(&tstamp->clock);
+ write_unlock(&tstamp->lock);
+
+ *ts = ns_to_timespec64(ns);
+
+ return 0;
+}
+
+static int mlx5e_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+ struct mlx5e_tstamp *tstamp = container_of(ptp, struct mlx5e_tstamp,
+ ptp_info);
+
+ write_lock(&tstamp->lock);
+ timecounter_adjtime(&tstamp->clock, delta);
+ write_unlock(&tstamp->lock);
+
+ return 0;
+}
+
+static int mlx5e_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
+{
+ u64 adj;
+ u32 diff;
+ int neg_adj = 0;
+ struct mlx5e_tstamp *tstamp = container_of(ptp, struct mlx5e_tstamp,
+ ptp_info);
+
+ if (delta < 0) {
+ neg_adj = 1;
+ delta = -delta;
+ }
+
+ adj = tstamp->nominal_c_mult;
+ adj *= delta;
+ diff = div_u64(adj, 1000000000ULL);
+
+ write_lock(&tstamp->lock);
+ timecounter_read(&tstamp->clock);
+ tstamp->cycles.mult = neg_adj ? tstamp->nominal_c_mult - diff :
+ tstamp->nominal_c_mult + diff;
+ write_unlock(&tstamp->lock);
+
+ return 0;
+}
+
+static const struct ptp_clock_info mlx5e_ptp_clock_info = {
+ .owner = THIS_MODULE,
+ .max_adj = 100000000,
+ .n_alarm = 0,
+ .n_ext_ts = 0,
+ .n_per_out = 0,
+ .n_pins = 0,
+ .pps = 0,
+ .adjfreq = mlx5e_ptp_adjfreq,
+ .adjtime = mlx5e_ptp_adjtime,
+ .gettime64 = mlx5e_ptp_gettime,
+ .settime64 = mlx5e_ptp_settime,
+ .enable = NULL,
+};
+
static void mlx5e_timestamp_init_config(struct mlx5e_tstamp *tstamp)
{
tstamp->hwtstamp_config.tx_type = HWTSTAMP_TX_OFF;
@@ -174,6 +257,18 @@
schedule_delayed_work(&tstamp->overflow_work, 0);
else
mlx5_core_warn(priv->mdev, "invalid overflow period, overflow_work is not scheduled\n");
+
+ /* Configure the PHC */
+ tstamp->ptp_info = mlx5e_ptp_clock_info;
+ snprintf(tstamp->ptp_info.name, 16, "mlx5 ptp");
+
+ tstamp->ptp = ptp_clock_register(&tstamp->ptp_info,
+ &priv->mdev->pdev->dev);
+ if (IS_ERR_OR_NULL(tstamp->ptp)) {
+ mlx5_core_warn(priv->mdev, "ptp_clock_register failed %ld\n",
+ PTR_ERR(tstamp->ptp));
+ tstamp->ptp = NULL;
+ }
}
void mlx5e_timestamp_cleanup(struct mlx5e_priv *priv)
@@ -183,5 +278,10 @@
if (!MLX5_CAP_GEN(priv->mdev, device_frequency_khz))
return;
+ if (priv->tstamp.ptp) {
+ ptp_clock_unregister(priv->tstamp.ptp);
+ priv->tstamp.ptp = NULL;
+ }
+
cancel_delayed_work_sync(&tstamp->overflow_work);
}