xref: /linux/arch/arm/lib/io-readsw-armv3.S (revision 84d69848c97faab0c25aa2667b273404d2e2a64a)
1/*
2 *  linux/arch/arm/lib/io-readsw-armv3.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#include <asm/export.h>
13
14.Linsw_bad_alignment:
15		adr	r0, .Linsw_bad_align_msg
16		mov	r2, lr
17		b	panic
18.Linsw_bad_align_msg:
19		.asciz	"insw: bad buffer alignment (0x%p, lr=0x%08lX)\n"
20		.align
21
22.Linsw_align:	tst	r1, #1
23		bne	.Linsw_bad_alignment
24
25		ldr	r3, [r0]
26		strb	r3, [r1], #1
27		mov	r3, r3, lsr #8
28		strb	r3, [r1], #1
29
30		subs	r2, r2, #1
31		reteq	lr
32
33ENTRY(__raw_readsw)
34		teq	r2, #0		@ do we have to check for the zero len?
35		reteq	lr
36		tst	r1, #3
37		bne	.Linsw_align
38
39.Linsw_aligned:	mov	ip, #0xff
40		orr	ip, ip, ip, lsl #8
41		stmfd	sp!, {r4, r5, r6, lr}
42
43		subs	r2, r2, #8
44		bmi	.Lno_insw_8
45
46.Linsw_8_lp:	ldr	r3, [r0]
47		and	r3, r3, ip
48		ldr	r4, [r0]
49		orr	r3, r3, r4, lsl #16
50
51		ldr	r4, [r0]
52		and	r4, r4, ip
53		ldr	r5, [r0]
54		orr	r4, r4, r5, lsl #16
55
56		ldr	r5, [r0]
57		and	r5, r5, ip
58		ldr	r6, [r0]
59		orr	r5, r5, r6, lsl #16
60
61		ldr	r6, [r0]
62		and	r6, r6, ip
63		ldr	lr, [r0]
64		orr	r6, r6, lr, lsl #16
65
66		stmia	r1!, {r3 - r6}
67
68		subs	r2, r2, #8
69		bpl	.Linsw_8_lp
70
71		tst	r2, #7
72		ldmeqfd	sp!, {r4, r5, r6, pc}
73
74.Lno_insw_8:	tst	r2, #4
75		beq	.Lno_insw_4
76
77		ldr	r3, [r0]
78		and	r3, r3, ip
79		ldr	r4, [r0]
80		orr	r3, r3, r4, lsl #16
81
82		ldr	r4, [r0]
83		and	r4, r4, ip
84		ldr	r5, [r0]
85		orr	r4, r4, r5, lsl #16
86
87		stmia	r1!, {r3, r4}
88
89.Lno_insw_4:	tst	r2, #2
90		beq	.Lno_insw_2
91
92		ldr	r3, [r0]
93		and	r3, r3, ip
94		ldr	r4, [r0]
95		orr	r3, r3, r4, lsl #16
96
97		str	r3, [r1], #4
98
99.Lno_insw_2:	tst	r2, #1
100		ldrne	r3, [r0]
101		strneb	r3, [r1], #1
102		movne	r3, r3, lsr #8
103		strneb	r3, [r1]
104
105		ldmfd	sp!, {r4, r5, r6, pc}
106
107EXPORT_SYMBOL(__raw_readsw)
108