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 000000000000..8f4e3193342e
--- /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 */