diff --git a/drivers/net/ethernet/intel/e1000e/ptp.c b/drivers/net/ethernet/intel/e1000e/ptp.c
index 0e488e4fa5c1..6e5a1720e6cd 100644
--- a/drivers/net/ethernet/intel/e1000e/ptp.c
+++ b/drivers/net/ethernet/intel/e1000e/ptp.c
@@ -29,17 +29,11 @@ static int e1000e_phc_adjfine(struct ptp_clock_info *ptp, long delta)
 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 						     ptp_clock_info);
 	struct e1000_hw *hw = &adapter->hw;
-	bool neg_adj = false;
 	unsigned long flags;
-	u64 adjustment;
-	u32 timinca, incvalue;
+	u64 incvalue;
+	u32 timinca;
 	s32 ret_val;
 
-	if (delta < 0) {
-		neg_adj = true;
-		delta = -delta;
-	}
-
 	/* Get the System Time Register SYSTIM base frequency */
 	ret_val = e1000e_get_base_timinca(adapter, &timinca);
 	if (ret_val)
@@ -48,11 +42,7 @@ static int e1000e_phc_adjfine(struct ptp_clock_info *ptp, long delta)
 	spin_lock_irqsave(&adapter->systim_lock, flags);
 
 	incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
-
-	adjustment = mul_u64_u64_div_u64(incvalue, (u64)delta,
-					 1000000ULL << 16);
-
-	incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
+	incvalue = adjust_by_scaled_ppm(incvalue, delta);
 
 	timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
 	timinca |= incvalue;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
index 2d3533f38d7b..33afa13b7812 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
@@ -347,23 +347,12 @@ static int i40e_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	struct i40e_pf *pf = container_of(ptp, struct i40e_pf, ptp_caps);
 	struct i40e_hw *hw = &pf->hw;
-	u64 adj, freq, diff;
-	int neg_adj = 0;
-
-	if (scaled_ppm < 0) {
-		neg_adj = 1;
-		scaled_ppm = -scaled_ppm;
-	}
+	u64 adj, base_adj;
 
 	smp_mb(); /* Force any pending update before accessing. */
-	freq = I40E_PTP_40GB_INCVAL * READ_ONCE(pf->ptp_adj_mult);
-	diff = mul_u64_u64_div_u64(freq, (u64)scaled_ppm,
-				   1000000ULL << 16);
+	base_adj = I40E_PTP_40GB_INCVAL * READ_ONCE(pf->ptp_adj_mult);
 
-	if (neg_adj)
-		adj = I40E_PTP_40GB_INCVAL - diff;
-	else
-		adj = I40E_PTP_40GB_INCVAL + diff;
+	adj = adjust_by_scaled_ppm(base_adj, scaled_ppm);
 
 	wr32(hw, I40E_PRTTSYN_INC_L, adj & 0xFFFFFFFF);
 	wr32(hw, I40E_PRTTSYN_INC_H, adj >> 32);
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 72b663108a4a..1c5bdc5394f4 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1103,24 +1103,10 @@ static int ice_ptp_adjfine(struct ptp_clock_info *info, long scaled_ppm)
 {
 	struct ice_pf *pf = ptp_info_to_pf(info);
 	struct ice_hw *hw = &pf->hw;
-	u64 incval, diff;
-	int neg_adj = 0;
+	u64 incval;
 	int err;
 
-	incval = ice_base_incval(pf);
-
-	if (scaled_ppm < 0) {
-		neg_adj = 1;
-		scaled_ppm = -scaled_ppm;
-	}
-
-	diff = mul_u64_u64_div_u64(incval, (u64)scaled_ppm,
-				   1000000ULL << 16);
-	if (neg_adj)
-		incval -= diff;
-	else
-		incval += diff;
-
+	incval = adjust_by_scaled_ppm(ice_base_incval(pf), scaled_ppm);
 	err = ice_ptp_write_incval_locked(hw, incval);
 	if (err) {
 		dev_err(ice_pf_to_dev(pf), "PTP failed to set incval, err %d\n",
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index 15e57460e19e..6f471b91f562 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -195,23 +195,9 @@ static int igb_ptp_adjfine_82576(struct ptp_clock_info *ptp, long scaled_ppm)
 	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
 					       ptp_caps);
 	struct e1000_hw *hw = &igb->hw;
-	int neg_adj = 0;
-	u64 rate;
-	u32 incvalue;
+	u64 incvalue;
 
-	if (scaled_ppm < 0) {
-		neg_adj = 1;
-		scaled_ppm = -scaled_ppm;
-	}
-
-	incvalue = INCVALUE_82576;
-	rate = mul_u64_u64_div_u64(incvalue, (u64)scaled_ppm,
-				   1000000ULL << 16);
-
-	if (neg_adj)
-		incvalue -= rate;
-	else
-		incvalue += rate;
+	incvalue = adjust_by_scaled_ppm(INCVALUE_82576, scaled_ppm);
 
 	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue & INCVALUE_82576_MASK));
 
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
index 9f06896a049b..a78ff4ed8c8b 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
@@ -451,21 +451,11 @@ static int ixgbe_ptp_adjfine_82599(struct ptp_clock_info *ptp, long scaled_ppm)
 	struct ixgbe_adapter *adapter =
 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
 	struct ixgbe_hw *hw = &adapter->hw;
-	u64 incval, diff;
-	int neg_adj = 0;
-
-	if (scaled_ppm < 0) {
-		neg_adj = 1;
-		scaled_ppm = -scaled_ppm;
-	}
+	u64 incval;
 
 	smp_mb();
 	incval = READ_ONCE(adapter->base_incval);
-
-	diff = mul_u64_u64_div_u64(incval, scaled_ppm,
-				   1000000ULL << 16);
-
-	incval = neg_adj ? (incval - diff) : (incval + diff);
+	incval = adjust_by_scaled_ppm(incval, scaled_ppm);
 
 	switch (hw->mac.type) {
 	case ixgbe_mac_X540:
@@ -502,17 +492,11 @@ static int ixgbe_ptp_adjfine_X550(struct ptp_clock_info *ptp, long scaled_ppm)
 	struct ixgbe_adapter *adapter =
 			container_of(ptp, struct ixgbe_adapter, ptp_caps);
 	struct ixgbe_hw *hw = &adapter->hw;
-	int neg_adj = 0;
+	bool neg_adj;
 	u64 rate;
 	u32 inca;
 
-	if (scaled_ppm < 0) {
-		neg_adj = 1;
-		scaled_ppm = -scaled_ppm;
-	}
-
-	rate = mul_u64_u64_div_u64(IXGBE_X550_BASE_PERIOD, scaled_ppm,
-				   1000000ULL << 16);
+	neg_adj = diff_by_scaled_ppm(IXGBE_X550_BASE_PERIOD, scaled_ppm, &rate);
 
 	/* warn if rate is too large */
 	if (rate >= INCVALUE_MASK)
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index ad4aaadc2f7a..f4781c5766d6 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -248,6 +248,52 @@ static inline long scaled_ppm_to_ppb(long ppm)
 	return (long)ppb;
 }
 
+/**
+ * diff_by_scaled_ppm - Calculate difference using scaled ppm
+ * @base: the base increment value to adjust
+ * @scaled_ppm: scaled parts per million to adjust by
+ * @diff: on return, the absolute value of calculated diff
+ *
+ * Calculate the difference to adjust the base increment using scaled parts
+ * per million.
+ *
+ * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid
+ * possible overflow.
+ *
+ * Returns: true if scaled_ppm is negative, false otherwise
+ */
+static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff)
+{
+	bool negative = false;
+
+	if (scaled_ppm < 0) {
+		negative = true;
+		scaled_ppm = -scaled_ppm;
+	}
+
+	*diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16);
+
+	return negative;
+}
+
+/**
+ * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million
+ * @base: the base increment value to adjust
+ * @scaled_ppm: scaled parts per million frequency adjustment
+ *
+ * Helper function which calculates a new increment value based on the
+ * requested scaled parts per million adjustment.
+ */
+static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm)
+{
+	u64 diff;
+
+	if (diff_by_scaled_ppm(base, scaled_ppm, &diff))
+		return base - diff;
+
+	return base + diff;
+}
+
 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
 
 /**
