Fix 64-bit division in fpmath.h

Commit e6f51fb826ce98d436f445aae4eb9e9dba1f30e8 added some floating
point support for LITMUS^RT, but it used 64-bit division that ARM does
not support. Therefore, use the division functions from math64.h.

Signed-off-by: Christopher Kenna <cjk@cs.unc.edu>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/litmus/fpmath.h b/include/litmus/fpmath.h
index 04d4bcaeae96..642de98542c8 100644
--- a/include/litmus/fpmath.h
+++ b/include/litmus/fpmath.h
@@ -1,6 +1,8 @@
 #ifndef __FP_MATH_H__
 #define __FP_MATH_H__
 
+#include <linux/math64.h>
+
 #ifndef __KERNEL__
 #include <stdint.h>
 #define abs(x) (((x) < 0) ? -(x) : x)
@@ -32,7 +34,7 @@ static inline fp_t FP(fpbuf_t x)
 /* divide two integers to obtain a fixed point value  */
 static inline fp_t _frac(fpbuf_t a, fpbuf_t b)
 {
-        return _fp(FP(a).val / (b));
+        return _fp(div64_s64(FP(a).val, (b)));
 }
 
 static inline fpbuf_t _point(fp_t x)