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mlxsw: update adjfine to use adjust_by_scaled_ppm

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The mlxsw adjfine implementation in the spectrum_ptp.c file converts
scaled_ppm into ppb before updating a cyclecounter multiplier using the
standard "base * ppb / 1billion" calculation.

This can be re-written to use adjust_by_scaled_ppm, directly using the
scaled parts per million and reducing the amount of code required to
express this calculation.

We still calculate the parts per billion for passing into
mlxsw_sp_ptp_phc_adjfreq because this function requires the input to be in
parts per billion.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: Amit Cohen <amcohen@nvidia.com>
Cc: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20221114213701.815132-1-jacob.e.keller@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jacob Keller 2022-11-14 13:37:01 -08:00 committed by Jakub Kicinski
parent bf36267e3a
commit d82303df06
1 changed files with 3 additions and 15 deletions
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18
drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
View File

@ -189,29 +189,17 @@ mlxsw_sp1_ptp_phc_settime(struct mlxsw_sp1_ptp_clock *clock, u64 nsec)
static int mlxsw_sp1_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
struct mlxsw_sp1_ptp_clock *clock = mlxsw_sp1_ptp_clock(ptp);
int neg_adj = 0;
u32 diff;
u64 adj;
s32 ppb;
ppb = scaled_ppm_to_ppb(scaled_ppm);
if (ppb < 0) {
neg_adj = 1;
ppb = -ppb;
}
adj = clock->nominal_c_mult;
adj *= ppb;
diff = div_u64(adj, NSEC_PER_SEC);
spin_lock_bh(&clock->lock);
timecounter_read(&clock->tc);
clock->cycles.mult = neg_adj ? clock->nominal_c_mult - diff :
clock->nominal_c_mult + diff;
clock->cycles.mult = adjust_by_scaled_ppm(clock->nominal_c_mult,
scaled_ppm);
spin_unlock_bh(&clock->lock);
return mlxsw_sp_ptp_phc_adjfreq(&clock->common, neg_adj ? -ppb : ppb);
return mlxsw_sp_ptp_phc_adjfreq(&clock->common, ppb);
}
static int mlxsw_sp1_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)