xref: /openbmc/linux/arch/arm/lib/io-readsl.S (revision 9cfc5c90)
1/*
2 *  linux/arch/arm/lib/io-readsl.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
13ENTRY(__raw_readsl)
14		teq	r2, #0		@ do we have to check for the zero len?
15		reteq	lr
16		ands	ip, r1, #3
17		bne	3f
18
19		subs	r2, r2, #4
20		bmi	2f
21		stmfd	sp!, {r4, lr}
221:		ldr	r3, [r0, #0]
23		ldr	r4, [r0, #0]
24		ldr	ip, [r0, #0]
25		ldr	lr, [r0, #0]
26		subs	r2, r2, #4
27		stmia	r1!, {r3, r4, ip, lr}
28		bpl	1b
29		ldmfd	sp!, {r4, lr}
302:		movs	r2, r2, lsl #31
31		ldrcs	r3, [r0, #0]
32		ldrcs	ip, [r0, #0]
33		stmcsia	r1!, {r3, ip}
34		ldrne	r3, [r0, #0]
35		strne	r3, [r1, #0]
36		ret	lr
37
383:		ldr	r3, [r0]
39		cmp	ip, #2
40		mov	ip, r3, get_byte_0
41		strb	ip, [r1], #1
42		bgt	6f
43		mov	ip, r3, get_byte_1
44		strb	ip, [r1], #1
45		beq	5f
46		mov	ip, r3, get_byte_2
47		strb	ip, [r1], #1
48
494:		subs	r2, r2, #1
50		mov	ip, r3, lspull #24
51		ldrne	r3, [r0]
52		orrne	ip, ip, r3, lspush #8
53		strne	ip, [r1], #4
54		bne	4b
55		b	8f
56
575:		subs	r2, r2, #1
58		mov	ip, r3, lspull #16
59		ldrne	r3, [r0]
60		orrne	ip, ip, r3, lspush #16
61		strne	ip, [r1], #4
62		bne	5b
63		b	7f
64
656:		subs	r2, r2, #1
66		mov	ip, r3, lspull #8
67		ldrne	r3, [r0]
68		orrne	ip, ip, r3, lspush #24
69		strne	ip, [r1], #4
70		bne	6b
71
72		mov	r3, ip, get_byte_2
73		strb	r3, [r1, #2]
747:		mov	r3, ip, get_byte_1
75		strb	r3, [r1, #1]
768:		mov	r3, ip, get_byte_0
77		strb	r3, [r1, #0]
78		ret	lr
79ENDPROC(__raw_readsl)
80