acrn-kernel/arch/arm26/lib/io-readsl.S

79 lines
1.5 KiB
ArmAsm

/*
* linux/arch/arm26/lib/io-readsl.S
*
* Copyright (C) 1995-2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/hardware.h>
/*
* Note that some reads can be aligned on half-word boundaries.
*/
ENTRY(__raw_readsl)
teq r2, #0 @ do we have to check for the zero len?
moveq pc, lr
ands ip, r1, #3
bne 2f
1: ldr r3, [r0]
str r3, [r1], #4
subs r2, r2, #1
bne 1b
mov pc, lr
2: cmp ip, #2
ldr ip, [r0]
blt 4f
bgt 6f
strb ip, [r1], #1
mov ip, ip, lsr #8
strb ip, [r1], #1
mov ip, ip, lsr #8
3: subs r2, r2, #1
ldrne r3, [r0]
orrne ip, ip, r3, lsl #16
strne ip, [r1], #4
movne ip, r3, lsr #16
bne 3b
strb ip, [r1], #1
mov ip, ip, lsr #8
strb ip, [r1], #1
mov pc, lr
4: strb ip, [r1], #1
mov ip, ip, lsr #8
strb ip, [r1], #1
mov ip, ip, lsr #8
strb ip, [r1], #1
mov ip, ip, lsr #8
5: subs r2, r2, #1
ldrne r3, [r0]
orrne ip, ip, r3, lsl #8
strne ip, [r1], #4
movne ip, r3, lsr #24
bne 5b
strb ip, [r1], #1
mov pc, lr
6: strb ip, [r1], #1
mov ip, ip, lsr #8
7: subs r2, r2, #1
ldrne r3, [r0]
orrne ip, ip, r3, lsl #24
strne ip, [r1], #4
movne ip, r3, lsr #8
bne 7b
strb ip, [r1], #1
mov ip, ip, lsr #8
strb ip, [r1], #1
mov ip, ip, lsr #8
strb ip, [r1], #1
mov pc, lr