Thumb-2: Add macros for the unified assembler syntax

This patch adds various C and assembler macros that help with using
the unified assembler syntax for compiling files to either ARM or
Thumb-2 modes.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm/Kconfig

@@ -983,6 +983,9 @@ config HZ
 	default AT91_TIMER_HZ if ARCH_AT91
 	default 100
 
+config ARM_ASM_UNIFIED
+	bool
+
 config AEABI
 	bool "Use the ARM EABI to compile the kernel"
 	help

arch/arm/Makefile

@@ -95,7 +95,7 @@ endif
 
 # Need -Uarm for gcc < 3.x
 KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
-KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float
+KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
 
 CHECKFLAGS	+= -D__arm__
 

arch/arm/include/asm/unified.h

+/*
+ * include/asm-arm/unified.h - Unified Assembler Syntax helper macros
+ *
+ * Copyright (C) 2008 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __ASM_UNIFIED_H
+#define __ASM_UNIFIED_H
+
+#if defined(__ASSEMBLY__) && defined(CONFIG_ARM_ASM_UNIFIED)
+	.syntax unified
+#endif
+
+#ifdef CONFIG_THUMB2_KERNEL
+
+#if __GNUC__ < 4
+#error Thumb-2 kernel requires gcc >= 4
+#endif
+
+/* The CPSR bit describing the instruction set (Thumb) */
+#define PSR_ISETSTATE	PSR_T_BIT
+
+#define ARM(x...)
+#define THUMB(x...)	x
+#define W(instr)	instr.w
+#define BSYM(sym)	sym + 1
+
+#else	/* !CONFIG_THUMB2_KERNEL */
+
+/* The CPSR bit describing the instruction set (ARM) */
+#define PSR_ISETSTATE	0
+
+#define ARM(x...)	x
+#define THUMB(x...)
+#define W(instr)	instr
+#define BSYM(sym)	sym
+
+#endif	/* CONFIG_THUMB2_KERNEL */
+
+#ifndef CONFIG_ARM_ASM_UNIFIED
+
+/*
+ * If the unified assembly syntax isn't used (in ARM mode), these
+ * macros expand to an empty string
+ */
+#ifdef __ASSEMBLY__
+	.macro	it, cond
+	.endm
+	.macro	itt, cond
+	.endm
+	.macro	ite, cond
+	.endm
+	.macro	ittt, cond
+	.endm
+	.macro	itte, cond
+	.endm
+	.macro	itet, cond
+	.endm
+	.macro	itee, cond
+	.endm
+	.macro	itttt, cond
+	.endm
+	.macro	ittte, cond
+	.endm
+	.macro	ittet, cond
+	.endm
+	.macro	ittee, cond
+	.endm
+	.macro	itett, cond
+	.endm
+	.macro	itete, cond
+	.endm
+	.macro	iteet, cond
+	.endm
+	.macro	iteee, cond
+	.endm
+#else	/* !__ASSEMBLY__ */
+__asm__(
+"	.macro	it, cond\n"
+"	.endm\n"
+"	.macro	itt, cond\n"
+"	.endm\n"
+"	.macro	ite, cond\n"
+"	.endm\n"
+"	.macro	ittt, cond\n"
+"	.endm\n"
+"	.macro	itte, cond\n"
+"	.endm\n"
+"	.macro	itet, cond\n"
+"	.endm\n"
+"	.macro	itee, cond\n"
+"	.endm\n"
+"	.macro	itttt, cond\n"
+"	.endm\n"
+"	.macro	ittte, cond\n"
+"	.endm\n"
+"	.macro	ittet, cond\n"
+"	.endm\n"
+"	.macro	ittee, cond\n"
+"	.endm\n"
+"	.macro	itett, cond\n"
+"	.endm\n"
+"	.macro	itete, cond\n"
+"	.endm\n"
+"	.macro	iteet, cond\n"
+"	.endm\n"
+"	.macro	iteee, cond\n"
+"	.endm\n");
+#endif	/* __ASSEMBLY__ */
+
+#endif	/* CONFIG_ARM_ASM_UNIFIED */
+
+#endif	/* !__ASM_UNIFIED_H */