/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */

#include <linux/linkage.h>

#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/asm-extable.h>
#include <asm/errno.h>
#include <asm/regdef.h>

.L_fixup_handle_unaligned:
        li.w    a0, -EFAULT
        jr      ra

/*
 * unsigned long unaligned_read(void *addr, void *value, unsigned long n, bool sign)
 *
 * a0: addr
 * a1: value
 * a2: n
 * a3: sign
 */
SYM_FUNC_START(unaligned_read)
        beqz            a2, 5f

        li.w            t2, 0
        LONG_ADDI       t0, a2, -1
        PTR_SLLI        t1, t0, LONGLOG
        PTR_ADD         a0, a0, t0

        beqz            a3, 2f
1:      ld.b            t3, a0, 0
        b               3f

2:      ld.bu           t3, a0, 0
3:      LONG_SLLV       t3, t3, t1
        or              t2, t2, t3
        LONG_ADDI       t1, t1, -8
        PTR_ADDI        a0, a0, -1
        PTR_ADDI        a2, a2, -1
        bgtz            a2, 2b
4:      LONG_S          t2, a1, 0

        move            a0, a2
        jr              ra

5:      li.w            a0, -EFAULT
        jr              ra

        _asm_extable    1b, .L_fixup_handle_unaligned
        _asm_extable    2b, .L_fixup_handle_unaligned
        _asm_extable    4b, .L_fixup_handle_unaligned
SYM_FUNC_END(unaligned_read)

/*
 * unsigned long unaligned_write(void *addr, unsigned long value, unsigned long n)
 *
 * a0: addr
 * a1: value
 * a2: n
 */
SYM_FUNC_START(unaligned_write)
        beqz            a2, 3f

        li.w            t0, 0
1:      LONG_SRLV       t1, a1, t0
2:      st.b            t1, a0, 0
        LONG_ADDI       t0, t0, 8
        PTR_ADDI        a2, a2, -1
        PTR_ADDI        a0, a0, 1
        bgtz            a2, 1b

        move            a0, a2
        jr              ra

3:      li.w            a0, -EFAULT
        jr              ra

        _asm_extable    2b, .L_fixup_handle_unaligned
SYM_FUNC_END(unaligned_write)