io-writesw-armv3.s

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

/*
 *  linux/arch/arm/lib/io-readsb.S
 *
 *  Copyright (C) 1995-2000 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.
 */
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/hardware.h>

.outsw_bad_alignment:
		adr	r0, .outsw_bad_align_msg
		mov	r2, lr
		b	SYMBOL_NAME(panic)
.outsw_bad_align_msg:
		.asciz	"outsw: bad buffer alignment (0x%p, lr=0x%08lX)\n"
		.align

.outsw_align:	tst	r1, #1
		bne	.outsw_bad_alignment

		add	r1, r1, #2

		ldr	r3, [r1, #-4]
		mov	r3, r3, lsr #16
		orr	r3, r3, r3, lsl #16
		str	r3, [r0]
		subs	r2, r2, #1
		RETINSTR(moveq, pc, lr)

ENTRY(__arch_writesw)
		tst	r1, #3
		bne	.outsw_align

.outsw_aligned:	stmfd	sp!, {r4, r5, r6, lr}

		subs	r2, r2, #8
		bmi	.no_outsw_8
.outsw_8_lp:	ldmia	r1!, {r3, r4, r5, r6}

		mov	ip, r3, lsl #16
		orr	ip, ip, ip, lsr #16
		str	ip, [r0]

		mov	ip, r3, lsr #16
		orr	ip, ip, ip, lsl #16
		str	ip, [r0]

		mov	ip, r4, lsl #16
		orr	ip, ip, ip, lsr #16
		str	ip, [r0]

		mov	ip, r4, lsr #16
		orr	ip, ip, ip, lsl #16
		str	ip, [r0]

		mov	ip, r5, lsl #16
		orr	ip, ip, ip, lsr #16
		str	ip, [r0]

		mov	ip, r5, lsr #16
		orr	ip, ip, ip, lsl #16
		str	ip, [r0]

		mov	ip, r6, lsl #16
		orr	ip, ip, ip, lsr #16
		str	ip, [r0]

		mov	ip, r6, lsr #16
		orr	ip, ip, ip, lsl #16
		str	ip, [r0]

		subs	r2, r2, #8
		bpl	.outsw_8_lp
		tst	r2, #7
		LOADREGS(eqfd, sp!, {r4, r5, r6, pc})

.no_outsw_8:	tst	r2, #4
		beq	.no_outsw_4

		ldmia	r1!, {r3, r4}

		mov	ip, r3, lsl #16
		orr	ip, ip, ip, lsr #16
		str	ip, [r0]

		mov	ip, r3, lsr #16
		orr	ip, ip, ip, lsl #16
		str	ip, [r0]

		mov	ip, r4, lsl #16
		orr	ip, ip, ip, lsr #16
		str	ip, [r0]

		mov	ip, r4, lsr #16
		orr	ip, ip, ip, lsl #16
		str	ip, [r0]

.no_outsw_4:	tst	r2, #2
		beq	.no_outsw_2

		ldr	r3, [r1], #4

		mov	ip, r3, lsl #16
		orr	ip, ip, ip, lsr #16
		str	ip, [r0]

		mov	ip, r3, lsr #16
		orr	ip, ip, ip, lsl #16
		str	ip, [r0]

.no_outsw_2:	tst	r2, #1

		ldrne	r3, [r1]

		movne	ip, r3, lsl #16
		orrne	ip, ip, ip, lsr #16
		strne	ip, [r0]

		LOADREGS(fd, sp!, {r4, r5, r6, pc})