xref: /linux/arch/arm/lib/io-writesw-armv4.S (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1/*
2 *  linux/arch/arm/lib/io-writesw-armv4.S
3 *
4 *  Copyright (C) 1995-2000 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/linkage.h>
11#include <asm/assembler.h>
12
13		.macro	outword, rd
14#ifndef __ARMEB__
15		strh	\rd, [r0]
16		mov	\rd, \rd, lsr #16
17		strh	\rd, [r0]
18#else
19		mov	lr, \rd, lsr #16
20		strh	lr, [r0]
21		strh	\rd, [r0]
22#endif
23		.endm
24
25.Loutsw_align:	movs	ip, r1, lsl #31
26		bne	.Loutsw_noalign
27
28		ldrh	r3, [r1], #2
29		sub	r2, r2, #1
30		strh	r3, [r0]
31
32ENTRY(__raw_writesw)
33		teq	r2, #0
34		moveq	pc, lr
35		ands	r3, r1, #3
36		bne	.Loutsw_align
37
38		stmfd	sp!, {r4, r5, lr}
39
40		subs	r2, r2, #8
41		bmi	.Lno_outsw_8
42
43.Loutsw_8_lp:	ldmia	r1!, {r3, r4, r5, ip}
44		subs	r2, r2, #8
45		outword	r3
46		outword	r4
47		outword	r5
48		outword	ip
49		bpl	.Loutsw_8_lp
50
51.Lno_outsw_8:	tst	r2, #4
52		beq	.Lno_outsw_4
53
54		ldmia	r1!, {r3, ip}
55		outword	r3
56		outword	ip
57
58.Lno_outsw_4:	movs	r2, r2, lsl #31
59		bcc	.Lno_outsw_2
60
61		ldr	r3, [r1], #4
62		outword	r3
63
64.Lno_outsw_2:	ldrneh	r3, [r1]
65		strneh	r3, [r0]
66
67		ldmfd	sp!, {r4, r5, pc}
68
69#ifdef __ARMEB__
70#define pull_hbyte0	lsl #8
71#define push_hbyte1	lsr #24
72#else
73#define pull_hbyte0	lsr #24
74#define push_hbyte1	lsl #8
75#endif
76
77.Loutsw_noalign:
78 ARM(		ldr	r3, [r1, -r3]!	)
79 THUMB(		rsb	r3, r3, #0	)
80 THUMB(		ldr	r3, [r1, r3]	)
81 THUMB(		sub	r1, r3		)
82		subcs	r2, r2, #1
83		bcs	2f
84		subs	r2, r2, #2
85		bmi	3f
86
871:		mov	ip, r3, lsr #8
88		strh	ip, [r0]
892:		mov	ip, r3, pull_hbyte0
90		ldr	r3, [r1, #4]!
91		subs	r2, r2, #2
92		orr	ip, ip, r3, push_hbyte1
93		strh	ip, [r0]
94		bpl	1b
95
96		tst	r2, #1
973:		movne	ip, r3, lsr #8
98		strneh	ip, [r0]
99		mov	pc, lr
100ENDPROC(__raw_writesw)
101