net: dsa: felix: update base time of time-aware shaper when adjusting PTP time

When adjusting the PTP clock, the base time of the TAS configuration
will become unreliable. We need reset the TAS configuration by using a
new base time.

For example, if the driver gets a base time 0 of Qbv configuration from
user, and current time is 20000. The driver will set the TAS base time
to be 20000. After the PTP clock adjustment, the current time becomes
10000. If the TAS base time is still 20000, it will be a future time,
and TAS entry list will stop running. Another example, if the current
time becomes to be 10000000 after PTP clock adjust, a large time offset
can cause the hardware to hang.

This patch introduces a tas_clock_adjust() function to reset the TAS
module by using a new base time after the PTP clock adjustment. This can
avoid issues above.

Due to PTP clock adjustment can occur at any time, it may conflict with
the TAS configuration. We introduce a new TAS lock to serialize the
access to the TAS registers.

Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 5f88385a7748..3737570116c3 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -575,6 +575,7 @@ struct ocelot_ops {
 	int (*psfp_stats_get)(struct ocelot *ocelot, struct flow_cls_offload *f,
 			      struct flow_stats *stats);
 	void (*cut_through_fwd)(struct ocelot *ocelot);
+	void (*tas_clock_adjust)(struct ocelot *ocelot);
 };
 
 struct ocelot_vcap_policer {
@@ -691,6 +692,9 @@ struct ocelot_port {
 	int				bridge_num;
 
 	int				speed;
+
+	/* Store the AdminBaseTime of EST fetched from userspace. */
+	s64				base_time;
 };
 
 struct ocelot {
@@ -757,6 +761,9 @@ struct ocelot {
 	/* Lock for serializing forwarding domain changes */
 	struct mutex			fwd_domain_lock;
 
+	/* Lock for serializing Time-Aware Shaper changes */
+	struct mutex			tas_lock;
+
 	struct workqueue_struct		*owq;
 
 	u8				ptp:1;