1 files changed, 58 insertions, 0 deletions
diff --git a/include/asm-generic/div64.h b/include/asm-generic/div64.h
new file mode 100644
index 00000000000..8f4e3193342
--- /dev/null
+++ b/include/asm-generic/div64.h
@@ -0,0 +1,58 @@
+#ifndef _ASM_GENERIC_DIV64_H
+#define _ASM_GENERIC_DIV64_H
+/*
+ * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
+ * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h
+ *
+ * The semantics of do_div() are:
+ *
+ * uint32_t do_div(uint64_t *n, uint32_t base)
+ * {
+ * 	uint32_t remainder = *n % base;
+ * 	*n = *n / base;
+ * 	return remainder;
+ * }
+ *
+ * NOTE: macro parameter n is evaluated multiple times,
+ *       beware of side effects!
+ */
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+
+#if BITS_PER_LONG == 64
+
+# define do_div(n,base) ({					\
+	uint32_t __base = (base);				\
+	uint32_t __rem;						\
+	__rem = ((uint64_t)(n)) % __base;			\
+	(n) = ((uint64_t)(n)) / __base;				\
+	__rem;							\
+ })
+
+#elif BITS_PER_LONG == 32
+
+extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
+
+/* The unnecessary pointer compare is there
+ * to check for type safety (n must be 64bit)
+ */
+# define do_div(n,base) ({				\
+	uint32_t __base = (base);			\
+	uint32_t __rem;					\
+	(void)(((typeof((n)) *)0) == ((uint64_t *)0));	\
+	if (likely(((n) >> 32) == 0)) {			\
+		__rem = (uint32_t)(n) % __base;		\
+		(n) = (uint32_t)(n) / __base;		\
+	} else 						\
+		__rem = __div64_32(&(n), __base);	\
+	__rem;						\
+ })
+
+#else /* BITS_PER_LONG == ?? */
+
+# error do_div() does not yet support the C64
+
+#endif /* BITS_PER_LONG */
+
+#endif /* _ASM_GENERIC_DIV64_H */