Re: [PATCH net-next 3/3] net/mlx5: Support getcyclesx and getcrosscycles

[Carolina Jubran]

On 17/07/2025 13:55, Paolo Abeni wrote:
> On 7/15/25 7:15 AM, Tariq Toukan wrote:
> > From: Carolina Jubran <cjubran@xxxxxxxxxx>
> >
> > Implement the getcyclesx64 and getcrosscycles callbacks in ptp_info to
> > expose the device’s raw free-running counter.
> >
> > Signed-off-by: Carolina Jubran <cjubran@xxxxxxxxxx>
> > Reviewed-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
> > Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
> > ---
> >   .../ethernet/mellanox/mlx5/core/lib/clock.c   | 74 ++++++++++++++++++-
> >   1 file changed, 73 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
> > index b1e2deeefc0c..2f75726674a9 100644
> > --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
> > +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
> > @@ -306,6 +306,23 @@ static int mlx5_mtctr_syncdevicetime(ktime_t *device_time,
> >   	return 0;
> >   }
> >   
> > +static int
> > +mlx5_mtctr_syncdevicecyclestime(ktime_t *device_time,
> > +				struct system_counterval_t *sys_counterval,
> > +				void *ctx)
> > +{
> > +	struct mlx5_core_dev *mdev = ctx;
> > +	u64 device;
> > +	int err;
> > +
> > +	err = mlx5_mtctr_read(mdev, false, sys_counterval, &device);
> > +	if (err)
> > +		return err;
> > +	*device_time = ns_to_ktime(device);
>
> If the goal is providing a raw cycle counter, why still using a timespec
> to the user space? A plain u64 would possibly be less ambiguous.
>
> /P

getcycles64 and getcrosscycles already return the cycle counter in a 
timespec64/ktime format, so I kept the new ioctls consistent with them.