microblaze: Fix __muldi3 function for little-endian.

__muldi3 was written for big endian platforms.
Code contained half word read/write instructions which
are not compatible with little endian cpu.
Asm __muldi3 implementation is replaced by C version.

Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/lib/muldi3.c

@@ -0,0 +1,60 @@
+#include <linux/module.h>
+
+#include "libgcc.h"
+
+#define DWtype long long
+#define UWtype unsigned long
+#define UHWtype unsigned short
+
+#define W_TYPE_SIZE 32
+
+#define __ll_B ((UWtype) 1 << (W_TYPE_SIZE / 2))
+#define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1))
+#define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2))
+
+/* If we still don't have umul_ppmm, define it using plain C.  */
+#if !defined(umul_ppmm)
+#define umul_ppmm(w1, w0, u, v)						\
+	do {								\
+		UWtype __x0, __x1, __x2, __x3;				\
+		UHWtype __ul, __vl, __uh, __vh;				\
+									\
+		__ul = __ll_lowpart(u);					\
+		__uh = __ll_highpart(u);				\
+		__vl = __ll_lowpart(v);					\
+		__vh = __ll_highpart(v);				\
+									\
+		__x0 = (UWtype) __ul * __vl;				\
+		__x1 = (UWtype) __ul * __vh;				\
+		__x2 = (UWtype) __uh * __vl;				\
+		__x3 = (UWtype) __uh * __vh;				\
+									\
+		__x1 += __ll_highpart(__x0); /* this can't give carry */\
+		__x1 += __x2; /* but this indeed can */			\
+		if (__x1 < __x2) /* did we get it? */			\
+		__x3 += __ll_B; /* yes, add it in the proper pos */	\
+									\
+		(w1) = __x3 + __ll_highpart(__x1);			\
+		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
+	} while (0)
+#endif
+
+#if !defined(__umulsidi3)
+#define __umulsidi3(u, v) ({				\
+	DWunion __w;					\
+	umul_ppmm(__w.s.high, __w.s.low, u, v);		\
+	__w.ll;						\
+	})
+#endif
+
+DWtype __muldi3(DWtype u, DWtype v)
+{
+	const DWunion uu = {.ll = u};
+	const DWunion vv = {.ll = v};
+	DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
+
+	w.s.high += ((UWtype) uu.s.low * (UWtype) vv.s.high
+		+ (UWtype) uu.s.high * (UWtype) vv.s.low);
+
+	return w.ll;
+}