root/arch/arm/lib/io-writesw-armv3.S
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  linux/arch/arm/lib/io-writesw-armv3.S
 *
 *  Copyright (C) 1995-2000 Russell King
 */
#include <linux/linkage.h>
#include <asm/assembler.h>

.Loutsw_bad_alignment:
                adr     r0, .Loutsw_bad_align_msg
                mov     r2, lr
                b       panic
.Loutsw_bad_align_msg:
                .asciz  "outsw: bad buffer alignment (0x%p, lr=0x%08lX)\n"
                .align

.Loutsw_align:  tst     r1, #1
                bne     .Loutsw_bad_alignment

                add     r1, r1, #2

                ldr     r3, [r1, #-4]
                mov     r3, r3, lsr #16
                orr     r3, r3, r3, lsl #16
                str     r3, [r0]
                subs    r2, r2, #1
                reteq   lr

ENTRY(__raw_writesw)
                teq     r2, #0          @ do we have to check for the zero len?
                reteq   lr
                tst     r1, #3
                bne     .Loutsw_align

                stmfd   sp!, {r4, r5, r6, lr}

                subs    r2, r2, #8
                bmi     .Lno_outsw_8

.Loutsw_8_lp:   ldmia   r1!, {r3, r4, r5, r6}

                mov     ip, r3, lsl #16
                orr     ip, ip, ip, lsr #16
                str     ip, [r0]

                mov     ip, r3, lsr #16
                orr     ip, ip, ip, lsl #16
                str     ip, [r0]

                mov     ip, r4, lsl #16
                orr     ip, ip, ip, lsr #16
                str     ip, [r0]

                mov     ip, r4, lsr #16
                orr     ip, ip, ip, lsl #16
                str     ip, [r0]

                mov     ip, r5, lsl #16
                orr     ip, ip, ip, lsr #16
                str     ip, [r0]

                mov     ip, r5, lsr #16
                orr     ip, ip, ip, lsl #16
                str     ip, [r0]

                mov     ip, r6, lsl #16
                orr     ip, ip, ip, lsr #16
                str     ip, [r0]

                mov     ip, r6, lsr #16
                orr     ip, ip, ip, lsl #16
                str     ip, [r0]

                subs    r2, r2, #8
                bpl     .Loutsw_8_lp

                tst     r2, #7
                ldmfdeq sp!, {r4, r5, r6, pc}

.Lno_outsw_8:   tst     r2, #4
                beq     .Lno_outsw_4

                ldmia   r1!, {r3, r4}

                mov     ip, r3, lsl #16
                orr     ip, ip, ip, lsr #16
                str     ip, [r0]

                mov     ip, r3, lsr #16
                orr     ip, ip, ip, lsl #16
                str     ip, [r0]

                mov     ip, r4, lsl #16
                orr     ip, ip, ip, lsr #16
                str     ip, [r0]

                mov     ip, r4, lsr #16
                orr     ip, ip, ip, lsl #16
                str     ip, [r0]

.Lno_outsw_4:   tst     r2, #2
                beq     .Lno_outsw_2

                ldr     r3, [r1], #4

                mov     ip, r3, lsl #16
                orr     ip, ip, ip, lsr #16
                str     ip, [r0]

                mov     ip, r3, lsr #16
                orr     ip, ip, ip, lsl #16
                str     ip, [r0]

.Lno_outsw_2:   tst     r2, #1

                ldrne   r3, [r1]

                movne   ip, r3, lsl #16
                orrne   ip, ip, ip, lsr #16
                strne   ip, [r0]

                ldmfd   sp!, {r4, r5, r6, pc}