assembler.h

linux 内核源代码

/*
 *  linux/include/asm-arm/assembler.h
 *
 *  Copyright (C) 1996-2000 Russell King
 *
 * 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 file contains arm architecture specific defines
 *  for the different processors.
 *
 *  Do not include any C declarations in this file - it is included by
 *  assembler source.
 */
#ifndef __ASSEMBLY__
#error "Only include this from assembly code"
#endif

#include <asm/ptrace.h>

/*
 * Endian independent macros for shifting bytes within registers.
 */
#ifndef __ARMEB__
#define pull            lsr
#define push            lsl
#define get_byte_0      lsl #0
#define get_byte_1	lsr #8
#define get_byte_2	lsr #16
#define get_byte_3	lsr #24
#define put_byte_0      lsl #0
#define put_byte_1	lsl #8
#define put_byte_2	lsl #16
#define put_byte_3	lsl #24
#else
#define pull            lsl
#define push            lsr
#define get_byte_0	lsr #24
#define get_byte_1	lsr #16
#define get_byte_2	lsr #8
#define get_byte_3      lsl #0
#define put_byte_0	lsl #24
#define put_byte_1	lsl #16
#define put_byte_2	lsl #8
#define put_byte_3      lsl #0
#endif

/*
 * Data preload for architectures that support it
 */
#if __LINUX_ARM_ARCH__ >= 5
#define PLD(code...)	code
#else
#define PLD(code...)
#endif

/*
 * Enable and disable interrupts
 */
#if __LINUX_ARM_ARCH__ >= 6
	.macro	disable_irq
	cpsid	i
	.endm

	.macro	enable_irq
	cpsie	i
	.endm
#else
	.macro	disable_irq
	msr	cpsr_c, #PSR_I_BIT | SVC_MODE
	.endm

	.macro	enable_irq
	msr	cpsr_c, #SVC_MODE
	.endm
#endif

/*
 * Save the current IRQ state and disable IRQs.  Note that this macro
 * assumes FIQs are enabled, and that the processor is in SVC mode.
 */
	.macro	save_and_disable_irqs, oldcpsr
	mrs	\oldcpsr, cpsr
	disable_irq
	.endm

/*
 * Restore interrupt state previously stored in a register.  We don't
 * guarantee that this will preserve the flags.
 */
	.macro	restore_irqs, oldcpsr
	msr	cpsr_c, \oldcpsr
	.endm

#define USER(x...)				\
9999:	x;					\
	.section __ex_table,"a";		\
	.align	3;				\
	.long	9999b,9001f;			\
	.previous