// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2023 SiFive
 * Author: Andy Chiu <andy.chiu@sifive.com>
 */
#include <linux/linkage.h>
#include <asm/asm.h>

#include <asm/vector.h>
#include <asm/simd.h>

#ifdef CONFIG_MMU
#include <asm/asm-prototypes.h>
#endif

#ifdef CONFIG_MMU
size_t riscv_v_usercopy_threshold = CONFIG_RISCV_ISA_V_UCOPY_THRESHOLD;
int __asm_vector_usercopy(void *dst, void *src, size_t n);
int __asm_vector_usercopy_sum_enabled(void *dst, void *src, size_t n);
int fallback_scalar_usercopy(void *dst, void *src, size_t n);
int fallback_scalar_usercopy_sum_enabled(void *dst, void *src, size_t n);
asmlinkage int enter_vector_usercopy(void *dst, void *src, size_t n,
                                     bool enable_sum)
{
        size_t remain, copied;

        /* skip has_vector() check because it has been done by the asm  */
        if (!may_use_simd())
                goto fallback;

        kernel_vector_begin();
        remain = enable_sum ? __asm_vector_usercopy(dst, src, n) :
                              __asm_vector_usercopy_sum_enabled(dst, src, n);
        kernel_vector_end();

        if (remain) {
                copied = n - remain;
                dst += copied;
                src += copied;
                n = remain;
                goto fallback;
        }

        return remain;

fallback:
        return enable_sum ? fallback_scalar_usercopy(dst, src, n) :
                            fallback_scalar_usercopy_sum_enabled(dst, src, n);
}
#endif