io-readsw-armv4.S

  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)