io-readsb.S

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 *  linux/arch/arm/lib/io-readsb.S
  4 *
  5 *  Copyright (C) 1995-2000 Russell King
  6 */
  7#include <linux/linkage.h>
  8#include <asm/assembler.h>
  9
 10.Linsb_align:	rsb	ip, ip, #4
 11		cmp	ip, r2
 12		movgt	ip, r2
 13		cmp	ip, #2
 14		ldrb	r3, [r0]
 15		strb	r3, [r1], #1
 16		ldrbge	r3, [r0]
 17		strbge	r3, [r1], #1
 18		ldrbgt	r3, [r0]
 19		strbgt	r3, [r1], #1
 20		subs	r2, r2, ip
 21		bne	.Linsb_aligned
 22
 23ENTRY(__raw_readsb)
 24		teq	r2, #0		@ do we have to check for the zero len?
 25		reteq	lr
 26		ands	ip, r1, #3
 27		bne	.Linsb_align
 28
 29.Linsb_aligned:	stmfd	sp!, {r4 - r6, lr}
 30
 31		subs	r2, r2, #16
 32		bmi	.Linsb_no_16
 33
 34.Linsb_16_lp:	ldrb	r3, [r0]
 35		ldrb	r4, [r0]
 36		ldrb	r5, [r0]
 37		mov	r3, r3,     put_byte_0
 38		ldrb	r6, [r0]
 39		orr	r3, r3, r4, put_byte_1
 40		ldrb	r4, [r0]
 41		orr	r3, r3, r5, put_byte_2
 42		ldrb	r5, [r0]
 43		orr	r3, r3, r6, put_byte_3
 44		ldrb	r6, [r0]
 45		mov	r4, r4,     put_byte_0
 46		ldrb	ip, [r0]
 47		orr	r4, r4, r5, put_byte_1
 48		ldrb	r5, [r0]
 49		orr	r4, r4, r6, put_byte_2
 50		ldrb	r6, [r0]
 51		orr	r4, r4, ip, put_byte_3
 52		ldrb	ip, [r0]
 53		mov	r5, r5,     put_byte_0
 54		ldrb	lr, [r0]
 55		orr	r5, r5, r6, put_byte_1
 56		ldrb	r6, [r0]
 57		orr	r5, r5, ip, put_byte_2
 58		ldrb	ip, [r0]
 59		orr	r5, r5, lr, put_byte_3
 60		ldrb	lr, [r0]
 61		mov	r6, r6,     put_byte_0
 62		orr	r6, r6, ip, put_byte_1
 63		ldrb	ip, [r0]
 64		orr	r6, r6, lr, put_byte_2
 65		orr	r6, r6, ip, put_byte_3
 66		stmia	r1!, {r3 - r6}
 67
 68		subs	r2, r2, #16
 69		bpl	.Linsb_16_lp
 70
 71		tst	r2, #15
 72		ldmfdeq	sp!, {r4 - r6, pc}
 73
 74.Linsb_no_16:	tst	r2, #8
 75		beq	.Linsb_no_8
 76
 77		ldrb	r3, [r0]
 78		ldrb	r4, [r0]
 79		ldrb	r5, [r0]
 80		mov	r3, r3,     put_byte_0
 81		ldrb	r6, [r0]
 82		orr	r3, r3, r4, put_byte_1
 83		ldrb	r4, [r0]
 84		orr	r3, r3, r5, put_byte_2
 85		ldrb	r5, [r0]
 86		orr	r3, r3, r6, put_byte_3
 87		ldrb	r6, [r0]
 88		mov	r4, r4,     put_byte_0
 89		ldrb	ip, [r0]
 90		orr	r4, r4, r5, put_byte_1
 91		orr	r4, r4, r6, put_byte_2
 92		orr	r4, r4, ip, put_byte_3
 93		stmia	r1!, {r3, r4}
 94
 95.Linsb_no_8:	tst	r2, #4
 96		beq	.Linsb_no_4
 97
 98		ldrb	r3, [r0]
 99		ldrb	r4, [r0]
100		ldrb	r5, [r0]
101		ldrb	r6, [r0]
102		mov	r3, r3,     put_byte_0
103		orr	r3, r3, r4, put_byte_1
104		orr	r3, r3, r5, put_byte_2
105		orr	r3, r3, r6, put_byte_3
106		str	r3, [r1], #4
107
108.Linsb_no_4:	ands	r2, r2, #3
109		ldmfdeq	sp!, {r4 - r6, pc}
110
111		cmp	r2, #2
112		ldrb	r3, [r0]
113		strb	r3, [r1], #1
114		ldrbge	r3, [r0]
115		strbge	r3, [r1], #1
116		ldrbgt	r3, [r0]
117		strbgt	r3, [r1]
118
119		ldmfd	sp!, {r4 - r6, pc}
120ENDPROC(__raw_readsb)