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authorJiri Kosina <jkosina@suse.cz>2008-05-06 16:57:55 +0200
committerJiri Kosina <jkosina@suse.cz>2008-05-06 16:57:55 +0200
commit7022b15e2a9f878fd5184586064c63352c3dd225 (patch)
tree5365c2f5bc82ae1946636ee8d5cd5d3b7e804f1b /include/linux/math64.h
parentaaad2b0c757f3e6e02552cb0bdcd91a5ec0d6305 (diff)
parenta15306365a16380f3bafee9e181ba01231d4acd7 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'include/linux/math64.h')
-rw-r--r--include/linux/math64.h84
1 files changed, 84 insertions, 0 deletions
diff --git a/include/linux/math64.h b/include/linux/math64.h
new file mode 100644
index 00000000000..c1a5f81501f
--- /dev/null
+++ b/include/linux/math64.h
@@ -0,0 +1,84 @@
+#ifndef _LINUX_MATH64_H
+#define _LINUX_MATH64_H
+
+#include <linux/types.h>
+#include <asm/div64.h>
+
+#if BITS_PER_LONG == 64
+
+/**
+ * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
+ *
+ * This is commonly provided by 32bit archs to provide an optimized 64bit
+ * divide.
+ */
+static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+ *remainder = dividend % divisor;
+ return dividend / divisor;
+}
+
+/**
+ * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
+ */
+static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
+{
+ *remainder = dividend % divisor;
+ return dividend / divisor;
+}
+
+/**
+ * div64_u64 - unsigned 64bit divide with 64bit divisor
+ */
+static inline u64 div64_u64(u64 dividend, u64 divisor)
+{
+ return dividend / divisor;
+}
+
+#elif BITS_PER_LONG == 32
+
+#ifndef div_u64_rem
+static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+ *remainder = do_div(dividend, divisor);
+ return dividend;
+}
+#endif
+
+#ifndef div_s64_rem
+extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
+#endif
+
+#ifndef div64_u64
+extern u64 div64_u64(u64 dividend, u64 divisor);
+#endif
+
+#endif /* BITS_PER_LONG */
+
+/**
+ * div_u64 - unsigned 64bit divide with 32bit divisor
+ *
+ * This is the most common 64bit divide and should be used if possible,
+ * as many 32bit archs can optimize this variant better than a full 64bit
+ * divide.
+ */
+#ifndef div_u64
+static inline u64 div_u64(u64 dividend, u32 divisor)
+{
+ u32 remainder;
+ return div_u64_rem(dividend, divisor, &remainder);
+}
+#endif
+
+/**
+ * div_s64 - signed 64bit divide with 32bit divisor
+ */
+#ifndef div_s64
+static inline s64 div_s64(s64 dividend, s32 divisor)
+{
+ s32 remainder;
+ return div_s64_rem(dividend, divisor, &remainder);
+}
+#endif
+
+#endif /* _LINUX_MATH64_H */