microblaze: Add muldi3.c which contains routines for _muldi3

Referenced arch/blackfin/lib/muldi3.c and the linux kernel.
Resolves issue seen when building u-boot for HW_MUL=0;

PLATFORM_CPPFLAGS += -mxl-soft-mul
PLATFORM_CPPFLAGS += -mno-xl-multiply-high

which resulted in error while linking to libgcc.a without mul hw (bs / m);

libgcc.a(_muldi3.o): In function `__muldi3':
.... src/gcc-4.6.2/libgcc/libgcc2.c:550: undefined reference to `_GLOBAL_OFFSET_TABLE_'

This link failure would not occur if we used gcc instead of ld directly, as
gcc will correctly use the crt's to resolve this link.

Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/lib/Makefile

@@ -29,6 +29,7 @@ SOBJS-y	+=
 
 COBJS-y	+= board.o
 COBJS-y	+= bootm.o
+COBJS-y	+= muldi3.o
 
 SRCS	:= $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))

arch/microblaze/lib/muldi3.c

@@ -0,0 +1,91 @@
+/*
+ * U-boot - muldi3.c contains routines for mult and div
+ *
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+/* Generic function got from GNU gcc package, libgcc2.c */
+#ifndef SI_TYPE_SIZE
+#define SI_TYPE_SIZE 32
+#endif
+#define __ll_B (1L << (SI_TYPE_SIZE / 2))
+#define __ll_lowpart(t) ((USItype) (t) % __ll_B)
+#define __ll_highpart(t) ((USItype) (t) / __ll_B)
+#define BITS_PER_UNIT 8
+
+#if !defined(umul_ppmm)
+#define umul_ppmm(w1, w0, u, v)						\
+	do {								\
+	USItype __x0, __x1, __x2, __x3;					\
+	USItype __ul, __vl, __uh, __vh;					\
+									\
+		__ul = __ll_lowpart(u);					\
+		__uh = __ll_highpart(u);				\
+		__vl = __ll_lowpart(v);					\
+		__vh = __ll_highpart(v);				\
+									\
+	__x0 = (USItype) __ul * __vl;					\
+	__x1 = (USItype) __ul * __vh;					\
+	__x2 = (USItype) __uh * __vl;					\
+	__x3 = (USItype) __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)						\
+	({DIunion __w;							\
+	umul_ppmm(__w.s.high, __w.s.low, u, v);		\
+	__w.ll; })
+#endif
+
+typedef unsigned int USItype __attribute__ ((mode(SI)));
+typedef int SItype __attribute__ ((mode(SI)));
+typedef int DItype __attribute__ ((mode(DI)));
+typedef int word_type __attribute__ ((mode(__word__)));
+
+struct DIstruct {
+	SItype low, high;
+};
+typedef union {
+	struct DIstruct s;
+	DItype ll;
+} DIunion;
+
+DItype __muldi3(DItype u, DItype v)
+{
+	DIunion w;
+	DIunion uu, vv;
+
+	uu.ll = u, vv.ll = v;
+	/*  panic("kernel panic for __muldi3"); */
+	w.ll = __umulsidi3(uu.s.low, vv.s.low);
+	w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
+		     + (USItype) uu.s.high * (USItype) vv.s.low);
+
+	return w.ll;
+}