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-rw-r--r--include/linux/gcd.h8
-rw-r--r--lib/Makefile2
-rw-r--r--lib/gcd.c18
3 files changed, 27 insertions, 1 deletions
diff --git a/include/linux/gcd.h b/include/linux/gcd.h
new file mode 100644
index 0000000..69f5e8a
--- /dev/null
+++ b/include/linux/gcd.h
@@ -0,0 +1,8 @@
+#ifndef _GCD_H
+#define _GCD_H
+
+#include <linux/compiler.h>
+
+unsigned long gcd(unsigned long a, unsigned long b) __attribute_const__;
+
+#endif /* _GCD_H */
diff --git a/lib/Makefile b/lib/Makefile
index 8e9bcf9..b6d1857 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -21,7 +21,7 @@ lib-y += kobject.o kref.o klist.o
obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
- string_helpers.o
+ string_helpers.o gcd.o
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
diff --git a/lib/gcd.c b/lib/gcd.c
new file mode 100644
index 0000000..f879033
--- /dev/null
+++ b/lib/gcd.c
@@ -0,0 +1,18 @@
+#include <linux/kernel.h>
+#include <linux/gcd.h>
+#include <linux/module.h>
+
+/* Greatest common divisor */
+unsigned long gcd(unsigned long a, unsigned long b)
+{
+ unsigned long r;
+
+ if (a < b)
+ swap(a, b);
+ while ((r = a % b) != 0) {
+ a = b;
+ b = r;
+ }
+ return b;
+}
+EXPORT_SYMBOL_GPL(gcd);
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