diff --git a/sys/compat/linuxkpi/common/include/linux/kernel.h b/sys/compat/linuxkpi/common/include/linux/kernel.h
--- a/sys/compat/linuxkpi/common/include/linux/kernel.h
+++ b/sys/compat/linuxkpi/common/include/linux/kernel.h
@@ -45,6 +45,7 @@
 #include <linux/compiler.h>
 #include <linux/container_of.h>
 #include <linux/limits.h>
+#include <linux/math.h>
 #include <linux/minmax.h>
 #include <linux/stringify.h>
 #include <linux/errno.h>
@@ -124,10 +125,7 @@
 #undef PTR_ALIGN
 #define	PTR_ALIGN(p, a)		((__typeof(p))ALIGN((uintptr_t)(p), (a)))
 #define	IS_ALIGNED(x, a)	(((x) & ((__typeof(x))(a) - 1)) == 0)
-#define	DIV_ROUND_UP(x, n)	howmany(x, n)
 #define	__KERNEL_DIV_ROUND_UP(x, n)	howmany(x, n)
-#define	DIV_ROUND_UP_ULL(x, n)	DIV_ROUND_UP((unsigned long long)(x), (n))
-#define	DIV_ROUND_DOWN_ULL(x, n) (((unsigned long long)(x) / (n)) * (n))
 #define	FIELD_SIZEOF(t, f)	sizeof(((t *)0)->f)
 
 #define	printk(...)		printf(__VA_ARGS__)
@@ -521,16 +519,6 @@
 #define offsetofend(t, m)	\
         (offsetof(t, m) + sizeof((((t *)0)->m)))
 
-/*
- * This looks more complex than it should be. But we need to
- * get the type for the ~ right in round_down (it needs to be
- * as wide as the result!), and we want to evaluate the macro
- * arguments just once each.
- */
-#define __round_mask(x, y) ((__typeof__(x))((y)-1))
-#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
-#define round_down(x, y) ((x) & ~__round_mask(x, y))
-
 #define	smp_processor_id()	PCPU_GET(cpuid)
 #define	num_possible_cpus()	mp_ncpus
 #define	num_online_cpus()	mp_ncpus
@@ -540,24 +528,6 @@
 #define	cpu_has_clflush		linux_cpu_has_clflush
 #endif
 
-#define	DIV_ROUND_CLOSEST(x, divisor)	(((x) + ((divisor) / 2)) / (divisor))
-
-#define	DIV_ROUND_CLOSEST_ULL(x, divisor) ({		\
-	__typeof(divisor) __d = (divisor);		\
-	unsigned long long __ret = (x) + (__d) / 2;	\
-	__ret /= __d;					\
-	__ret;						\
-})
-
-static inline uintmax_t
-mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor)
-{
-	uintmax_t q = (x / divisor);
-	uintmax_t r = (x % divisor);
-
-	return ((q * multiplier) + ((r * multiplier) / divisor));
-}
-
 typedef struct linux_ratelimit {
 	struct timeval lasttime;
 	int counter;
diff --git a/sys/compat/linuxkpi/common/include/linux/math.h b/sys/compat/linuxkpi/common/include/linux/math.h
new file mode 100644
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/math.h
@@ -0,0 +1,67 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
+ * Copyright (c) 2014-2015 François Tigeot
+ * Copyright (c) 2016 Matt Macy <mmacy@FreeBSD.org>
+ * Copyright (c) 2019 Johannes Lundberg <johalun@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _LINUXKPI_LINUX_MATH_H_
+#define	_LINUXKPI_LINUX_MATH_H_
+
+#include <linux/types.h>
+
+/*
+ * This looks more complex than it should be. But we need to
+ * get the type for the ~ right in round_down (it needs to be
+ * as wide as the result!), and we want to evaluate the macro
+ * arguments just once each.
+ */
+#define	__round_mask(x, y)	((__typeof__(x))((y)-1))
+#define	round_up(x, y)		((((x)-1) | __round_mask(x, y))+1)
+#define	round_down(x, y)	((x) & ~__round_mask(x, y))
+
+#define	DIV_ROUND_UP(x, n)	howmany(x, n)
+#define	DIV_ROUND_UP_ULL(x, n)	DIV_ROUND_UP((unsigned long long)(x), (n))
+#define	DIV_ROUND_DOWN_ULL(x, n) (((unsigned long long)(x) / (n)) * (n))
+
+#define	DIV_ROUND_CLOSEST(x, divisor)	(((x) + ((divisor) / 2)) / (divisor))
+#define	DIV_ROUND_CLOSEST_ULL(x, divisor) ({		\
+	__typeof(divisor) __d = (divisor);		\
+	unsigned long long __ret = (x) + (__d) / 2;	\
+	__ret /= __d;					\
+	__ret;						\
+})
+
+static inline uintmax_t
+mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor)
+{
+	uintmax_t q = (x / divisor);
+	uintmax_t r = (x % divisor);
+
+	return ((q * multiplier) + ((r * multiplier) / divisor));
+}
+
+#endif /* _LINUXKPI_LINUX_MATH_H_ */