xref: /openbmc/linux/arch/arm/lib/io-writesw-armv4.S (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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.outsw_align:	movs	ip, r1, lsl #31
26		bne	.outsw_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	.outsw_align
37
38		stmfd	sp!, {r4, r5, lr}
39
40		subs	r2, r2, #8
41		bmi	.no_outsw_8
42
43.outsw_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	.outsw_8_lp
50
51.no_outsw_8:	tst	r2, #4
52		beq	.no_outsw_4
53
54		ldmia	r1!, {r3, ip}
55		outword	r3
56		outword	ip
57
58.no_outsw_4:	movs	r2, r2, lsl #31
59		bcc	.no_outsw_2
60
61		ldr	r3, [r1], #4
62		outword	r3
63
64.no_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.outsw_noalign:	ldr	r3, [r1, -r3]!
78		subcs	r2, r2, #1
79		bcs	2f
80		subs	r2, r2, #2
81		bmi	3f
82
831:		mov	ip, r3, lsr #8
84		strh	ip, [r0]
852:		mov	ip, r3, pull_hbyte0
86		ldr	r3, [r1, #4]!
87		subs	r2, r2, #2
88		orr	ip, ip, r3, push_hbyte1
89		strh	ip, [r0]
90		bpl	2b
91
923:		tst	r2, #1
932:		movne	ip, r3, lsr #8
94		strneh	ip, [r0]
95		mov	pc, lr
96