xref: /openbmc/linux/arch/arm/lib/io-readsw-armv4.S (revision d9fd5a71)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *  linux/arch/arm/lib/io-readsw-armv4.S
4 *
5 *  Copyright (C) 1995-2000 Russell King
6 */
7#include <linux/linkage.h>
8#include <asm/assembler.h>
9
10		.macro	pack, rd, hw1, hw2
11#ifndef __ARMEB__
12		orr	\rd, \hw1, \hw2, lsl #16
13#else
14		orr	\rd, \hw2, \hw1, lsl #16
15#endif
16		.endm
17
18.Linsw_align:	movs	ip, r1, lsl #31
19		bne	.Linsw_noalign
20		ldrh	ip, [r0]
21		sub	r2, r2, #1
22		strh	ip, [r1], #2
23
24ENTRY(__raw_readsw)
25		teq	r2, #0
26		reteq	lr
27		tst	r1, #3
28		bne	.Linsw_align
29
30		stmfd	sp!, {r4, r5, lr}
31
32		subs	r2, r2, #8
33		bmi	.Lno_insw_8
34
35.Linsw_8_lp:	ldrh	r3, [r0]
36		ldrh	r4, [r0]
37		pack	r3, r3, r4
38
39		ldrh	r4, [r0]
40		ldrh	r5, [r0]
41		pack	r4, r4, r5
42
43		ldrh	r5, [r0]
44		ldrh	ip, [r0]
45		pack	r5, r5, ip
46
47		ldrh	ip, [r0]
48		ldrh	lr, [r0]
49		pack	ip, ip, lr
50
51		subs	r2, r2, #8
52		stmia	r1!, {r3 - r5, ip}
53		bpl	.Linsw_8_lp
54
55.Lno_insw_8:	tst	r2, #4
56		beq	.Lno_insw_4
57
58		ldrh	r3, [r0]
59		ldrh	r4, [r0]
60		pack	r3, r3, r4
61
62		ldrh	r4, [r0]
63		ldrh	ip, [r0]
64		pack	r4, r4, ip
65
66		stmia	r1!, {r3, r4}
67
68.Lno_insw_4:	movs	r2, r2, lsl #31
69		bcc	.Lno_insw_2
70
71		ldrh	r3, [r0]
72		ldrh	ip, [r0]
73		pack	r3, r3, ip
74		str	r3, [r1], #4
75
76.Lno_insw_2:	ldrhne	r3, [r0]
77		strhne	r3, [r1]
78
79		ldmfd	sp!, {r4, r5, pc}
80
81#ifdef __ARMEB__
82#define _BE_ONLY_(code...)	code
83#define _LE_ONLY_(code...)
84#define push_hbyte0		lsr #8
85#define pull_hbyte1		lsl #24
86#else
87#define _BE_ONLY_(code...)
88#define _LE_ONLY_(code...) code
89#define push_hbyte0		lsl #24
90#define pull_hbyte1		lsr #8
91#endif
92
93.Linsw_noalign:	stmfd	sp!, {r4, lr}
94		ldrbcc	ip, [r1, #-1]!
95		bcc	1f
96
97		ldrh	ip, [r0]
98		sub	r2, r2, #1
99   _BE_ONLY_(	mov	ip, ip, ror #8		)
100		strb	ip, [r1], #1
101   _LE_ONLY_(	mov	ip, ip, lsr #8		)
102   _BE_ONLY_(	mov	ip, ip, lsr #24		)
103
1041:		subs	r2, r2, #2
105		bmi	3f
106   _BE_ONLY_(	mov	ip, ip, lsl #24		)
107
1082:		ldrh	r3, [r0]
109		ldrh	r4, [r0]
110		subs	r2, r2, #2
111		orr	ip, ip, r3, lsl #8
112		orr	ip, ip, r4, push_hbyte0
113		str	ip, [r1], #4
114		mov	ip, r4, pull_hbyte1
115		bpl	2b
116
117   _BE_ONLY_(	mov	ip, ip, lsr #24		)
118
1193:		tst	r2, #1
120		strb	ip, [r1], #1
121		ldrhne	ip, [r0]
122   _BE_ONLY_(	movne	ip, ip, ror #8		)
123		strbne	ip, [r1], #1
124   _LE_ONLY_(	movne	ip, ip, lsr #8		)
125   _BE_ONLY_(	movne	ip, ip, lsr #24		)
126		strbne	ip, [r1]
127		ldmfd	sp!, {r4, pc}
128ENDPROC(__raw_readsw)
129