arm: lib: import muldi3.S from Linux
Import muldi3.S from Linux 4.4.6 , commit 0d1912303e54ed1b2a371be0bba51c384dd57326
on arm32. This file implements __aeabi_lmul and it's alias __muldi3, which
is needed when doing Thumb1 builds.
This patch also defines CONFIG_THUMB2_KERNEL and CONFIG_ARM_ASM_UNIFIED
which is necessary for correct build of these files both in ARM and
Thumb mode, just like Linux does.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/lib/muldi3.S b/arch/arm/lib/muldi3.S
new file mode 100644
index 0000000..daa5704
--- /dev/null
+++ b/arch/arm/lib/muldi3.S
@@ -0,0 +1,46 @@
+/*
+ * linux/arch/arm/lib/muldi3.S
+ *
+ * Author: Nicolas Pitre
+ * Created: Oct 19, 2005
+ * Copyright: Monta Vista Software, Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+#ifdef __ARMEB__
+#define xh r0
+#define xl r1
+#define yh r2
+#define yl r3
+#else
+#define xl r0
+#define xh r1
+#define yl r2
+#define yh r3
+#endif
+
+ENTRY(__muldi3)
+ENTRY(__aeabi_lmul)
+
+ mul xh, yl, xh
+ mla xh, xl, yh, xh
+ mov ip, xl, lsr #16
+ mov yh, yl, lsr #16
+ bic xl, xl, ip, lsl #16
+ bic yl, yl, yh, lsl #16
+ mla xh, yh, ip, xh
+ mul yh, xl, yh
+ mul xl, yl, xl
+ mul ip, yl, ip
+ adds xl, xl, yh, lsl #16
+ adc xh, xh, yh, lsr #16
+ adds xl, xl, ip, lsl #16
+ adc xh, xh, ip, lsr #16
+ ret lr
+
+ENDPROC(__muldi3)
+ENDPROC(__aeabi_lmul)