[patch 01/43] Move div_long_long_rem out of jiffies.h

[Thomas Gleixner <tglx@linutronix.de>]

plain text document attachment
(move-div-long-long-rem-out-of-jiffiesh.patch)

- 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.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

 include/linux/calc64.h  |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/jiffies.h |   11 +----------
 2 files changed, 47 insertions(+), 10 deletions(-)

Index: linux-2.6.15-rc2-rework/include/linux/calc64.h
===================================================================
--- /dev/null
+++ linux-2.6.15-rc2-rework/include/linux/calc64.h
@@ -0,0 +1,46 @@
+#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)	\
+({							\
+	u64 result = (dividend);			\
+							\
+	*(remainder) = do_div(result, divisor);		\
+	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
Index: linux-2.6.15-rc2-rework/include/linux/jiffies.h
===================================================================
--- linux-2.6.15-rc2-rework.orig/include/linux/jiffies.h
+++ linux-2.6.15-rc2-rework/include/linux/jiffies.h
@@ -1,21 +1,12 @@
 #ifndef _LINUX_JIFFIES_H
 #define _LINUX_JIFFIES_H
 
+#include <linux/calc64.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/time.h>
 #include <linux/timex.h>
 #include <asm/param.h>			/* for HZ */
-#include <asm/div64.h>
-
-#ifndef div_long_long_rem
-#define div_long_long_rem(dividend,divisor,remainder) \
-({							\
-	u64 result = dividend;				\
-	*remainder = do_div(result,divisor);		\
-	result;						\
-})
-#endif
 
 /*
  * The following defines establish the engineering parameters of the PLL

--