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authorThomas Gleixner <tglx@linutronix.de>2006-01-09 20:52:20 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-10 08:01:35 -0800
commit5cca7619a562c9d98a3a0123dc878d79bf3c8fb3 (patch)
tree5efaebf38b6e546e8653f010209bbe3a29831810 /include/linux/calc64.h
parentaf4cd3fe4cfa75ca74f8d8622867371289043a8d (diff)
[PATCH] hrtimer: move div_long_long_rem out of jiffies.h
move div_long_long_rem() from jiffies.h into a new calc64.h include file, as it is a general math function useful for other things than the jiffy code. Convert it to an inline function Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/calc64.h')
-rw-r--r--include/linux/calc64.h49
1 files changed, 49 insertions, 0 deletions
diff --git a/include/linux/calc64.h b/include/linux/calc64.h
new file mode 100644
index 000000000000..ebf4b8f38d88
--- /dev/null
+++ b/include/linux/calc64.h
@@ -0,0 +1,49 @@
+#ifndef _LINUX_CALC64_H
+#define _LINUX_CALC64_H
+
+#include <linux/types.h>
+#include <asm/div64.h>
+
+/*
+ * This is a generic macro which is used when the architecture
+ * specific div64.h does not provide a optimized one.
+ *
+ * The 64bit dividend is divided by the divisor (data type long), the
+ * result is returned and the remainder stored in the variable
+ * referenced by remainder (data type long *). In contrast to the
+ * do_div macro the dividend is kept intact.
+ */
+#ifndef div_long_long_rem
+#define div_long_long_rem(dividend, divisor, remainder) \
+ do_div_llr((dividend), divisor, remainder)
+
+static inline unsigned long do_div_llr(const long long dividend,
+ const long divisor, long *remainder)
+{
+ u64 result = dividend;
+
+ *(remainder) = do_div(result, divisor);
+ return (unsigned long) result;
+}
+#endif
+
+/*
+ * Sign aware variation of the above. On some architectures a
+ * negative dividend leads to an divide overflow exception, which
+ * is avoided by the sign check.
+ */
+static inline long div_long_long_rem_signed(const long long dividend,
+ const long divisor, long *remainder)
+{
+ long res;
+
+ if (unlikely(dividend < 0)) {
+ res = -div_long_long_rem(-dividend, divisor, remainder);
+ *remainder = -(*remainder);
+ } else
+ res = div_long_long_rem(dividend, divisor, remainder);
+
+ return res;
+}
+
+#endif