diff --git a/src/drivers/analogix/anx7625/anx7625.c b/src/drivers/analogix/anx7625/anx7625.c
index e3a5111..8726ac0 100644
--- a/src/drivers/analogix/anx7625/anx7625.c
+++ b/src/drivers/analogix/anx7625/anx7625.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <console/console.h>
+#include <commonlib/bsd/gcd.h>
 #include <delay.h>
 #include <device/i2c_simple.h>
 #include <edid.h>
@@ -152,30 +153,14 @@
 	return 0;
 }
 
-static unsigned long gcd(unsigned long a, unsigned long b)
-{
-	if (a == 0)
-		return b;
-
-	while (b != 0) {
-		if (a > b)
-			a = a - b;
-		else
-			b = b - a;
-	}
-
-	return a;
-}
-
 /* Reduce fraction a/b */
-static void anx7625_reduction_of_a_fraction(unsigned long *_a,
-					    unsigned long *_b)
+static void anx7625_reduction_of_a_fraction(u32 *_a, u32 *_b)
 {
-	unsigned long gcd_num;
-	unsigned long a = *_a, b = *_b, old_a, old_b;
+	u32 gcd_num;
+	u32 a = *_a, b = *_b, old_a, old_b;
 	u32 denom = 1;
 
-	gcd_num = gcd(a, b);
+	gcd_num = gcd32(a, b);
 	a /= gcd_num;
 	b /= gcd_num;
 
@@ -198,9 +183,7 @@
 	*_b = b;
 }
 
-static int anx7625_calculate_m_n(u32 pixelclock,
-				 unsigned long *m, unsigned long *n,
-				 uint8_t *pd)
+static int anx7625_calculate_m_n(u32 pixelclock, u32 *m, u32 *n, uint8_t *pd)
 {
 	uint8_t post_divider = *pd;
 	if (pixelclock > PLL_OUT_FREQ_ABS_MAX / POST_DIVIDER_MIN) {
@@ -300,7 +283,7 @@
 
 static int anx7625_dsi_video_config(uint8_t bus, struct display_timing *dt)
 {
-	unsigned long m, n;
+	u32 m, n;
 	u16 htotal;
 	int ret;
 	uint8_t post_divider = 0;
@@ -311,7 +294,7 @@
 		return -1;
 	}
 
-	ANXINFO("compute M(%lu), N(%lu), divider(%d).\n", m, n, post_divider);
+	ANXINFO("compute M(%u), N(%u), divider(%d).\n", m, n, post_divider);
 
 	/* configure pixel clock */
 	ret = anx7625_reg_write(bus, RX_P0_ADDR, PIXEL_CLOCK_L,
diff --git a/src/northbridge/intel/ironlake/quickpath.c b/src/northbridge/intel/ironlake/quickpath.c
index 8a0e01c..eb79347 100644
--- a/src/northbridge/intel/ironlake/quickpath.c
+++ b/src/northbridge/intel/ironlake/quickpath.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <commonlib/bsd/gcd.h>
 #include <console/console.h>
 #include <cpu/intel/model_2065x/model_2065x.h>
 #include <cpu/x86/msr.h>
@@ -11,31 +12,14 @@
 
 #define NORTHBRIDGE PCI_DEV(0, 0, 0)
 
-static unsigned int gcd(unsigned int a, unsigned int b)
-{
-	unsigned int t;
-	if (a > b) {
-		t = a;
-		a = b;
-		b = t;
-	}
-	/* invariant a < b.  */
-	while (a) {
-		t = b % a;
-		b = a;
-		a = t;
-	}
-	return b;
-}
-
 static inline int div_roundup(int a, int b)
 {
 	return DIV_ROUND_UP(a, b);
 }
 
-static unsigned int lcm(unsigned int a, unsigned int b)
+static u32 lcm(u32 a, u32 b)
 {
-	return (a * b) / gcd(a, b);
+	return (a * b) / gcd32(a, b);
 }
 
 struct stru1 {
@@ -65,7 +49,7 @@
 	int freq_max_reduced;
 	int freq3, freq4;
 
-	g = gcd(freq1, freq2);
+	g = gcd32(freq1, freq2);
 	freq1_reduced = freq1 / g;
 	freq2_reduced = freq2 / g;
 	freq_min_reduced = MIN(freq1_reduced, freq2_reduced);
diff --git a/src/soc/rockchip/rk3288/clock.c b/src/soc/rockchip/rk3288/clock.c
index c2f93f5..d52fa2a 100644
--- a/src/soc/rockchip/rk3288/clock.c
+++ b/src/soc/rockchip/rk3288/clock.c
@@ -1,9 +1,10 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
-#include <device/mmio.h>
 #include <assert.h>
+#include <commonlib/bsd/gcd.h>
 #include <console/console.h>
 #include <delay.h>
+#include <device/mmio.h>
 #include <lib.h>
 #include <soc/addressmap.h>
 #include <soc/clock.h>
@@ -438,16 +439,6 @@
 	}
 }
 
-static u32 clk_gcd(u32 a, u32 b)
-{
-	while (b != 0) {
-		int r = b;
-		b = a % b;
-		a = r;
-	}
-	return a;
-}
-
 void rkclk_configure_i2s(unsigned int hz)
 {
 	int n, d;
@@ -462,7 +453,7 @@
 			      1 << 15 | 0 << 12 | 1 << 8 | 0 << 0));
 
 	/* set frac divider */
-	v = clk_gcd(GPLL_HZ, hz);
+	v = gcd32(GPLL_HZ, hz);
 	n = (GPLL_HZ / v) & (0xffff);
 	d = (hz / v) & (0xffff);
 	assert(hz == GPLL_HZ / n * d);
diff --git a/src/soc/rockchip/rk3399/clock.c b/src/soc/rockchip/rk3399/clock.c
index 75af695b..fbff5a7 100644
--- a/src/soc/rockchip/rk3399/clock.c
+++ b/src/soc/rockchip/rk3399/clock.c
@@ -1,9 +1,10 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <assert.h>
+#include <commonlib/bsd/gcd.h>
 #include <console/console.h>
-#include <device/mmio.h>
 #include <delay.h>
+#include <device/mmio.h>
 #include <soc/addressmap.h>
 #include <soc/clock.h>
 #include <soc/grf.h>
@@ -776,16 +777,6 @@
 	return freq;
 }
 
-static u32 clk_gcd(u32 a, u32 b)
-{
-	while (b != 0) {
-		int r = b;
-		b = a % b;
-		a = r;
-	}
-	return a;
-}
-
 void rkclk_configure_i2s(unsigned int hz)
 {
 	int n, d;
@@ -805,7 +796,7 @@
 		RK_CLRBITS(1 << 12 | 1 << 5 | 1 << 4 | 1 << 3));
 
 	/* set frac divider */
-	v = clk_gcd(CPLL_HZ, hz);
+	v = gcd32(CPLL_HZ, hz);
 	n = (CPLL_HZ / v) & (0xffff);
 	d = (hz / v) & (0xffff);
 	assert(hz == (u64)CPLL_HZ * d / n);