/* SPDX-License-Identifier: GPL-2.0 */
/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */

#include <linux/export.h>
#include <linux/linkage.h>
#include <linux/cfi_types.h>
#include <asm/cpufeatures.h>
#include <asm/alternative.h>

/*
 * Some CPUs run faster using the string copy instructions (sane microcode).
 * It is also a lot simpler. Use this when possible. But, don't use streaming
 * copy unless the CPU indicates X86_FEATURE_REP_GOOD. Could vary the
 * prefetch distance based on SMP/UP.
 */
        ALIGN
SYM_TYPED_FUNC_START(copy_page)
        ALTERNATIVE "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD
        movl    $4096/8, %ecx
        rep     movsq
        RET
SYM_FUNC_END(copy_page)
EXPORT_SYMBOL(copy_page)

SYM_FUNC_START_LOCAL(copy_page_regs)
        subq    $2*8,   %rsp
        movq    %rbx,   (%rsp)
        movq    %r12,   1*8(%rsp)

        movl    $(4096/64)-5,   %ecx
        .p2align 4
.Loop64:
        dec     %rcx
        movq    0x8*0(%rsi), %rax
        movq    0x8*1(%rsi), %rbx
        movq    0x8*2(%rsi), %rdx
        movq    0x8*3(%rsi), %r8
        movq    0x8*4(%rsi), %r9
        movq    0x8*5(%rsi), %r10
        movq    0x8*6(%rsi), %r11
        movq    0x8*7(%rsi), %r12

        prefetcht0 5*64(%rsi)

        movq    %rax, 0x8*0(%rdi)
        movq    %rbx, 0x8*1(%rdi)
        movq    %rdx, 0x8*2(%rdi)
        movq    %r8,  0x8*3(%rdi)
        movq    %r9,  0x8*4(%rdi)
        movq    %r10, 0x8*5(%rdi)
        movq    %r11, 0x8*6(%rdi)
        movq    %r12, 0x8*7(%rdi)

        leaq    64 (%rsi), %rsi
        leaq    64 (%rdi), %rdi

        jnz     .Loop64

        movl    $5, %ecx
        .p2align 4
.Loop2:
        decl    %ecx

        movq    0x8*0(%rsi), %rax
        movq    0x8*1(%rsi), %rbx
        movq    0x8*2(%rsi), %rdx
        movq    0x8*3(%rsi), %r8
        movq    0x8*4(%rsi), %r9
        movq    0x8*5(%rsi), %r10
        movq    0x8*6(%rsi), %r11
        movq    0x8*7(%rsi), %r12

        movq    %rax, 0x8*0(%rdi)
        movq    %rbx, 0x8*1(%rdi)
        movq    %rdx, 0x8*2(%rdi)
        movq    %r8,  0x8*3(%rdi)
        movq    %r9,  0x8*4(%rdi)
        movq    %r10, 0x8*5(%rdi)
        movq    %r11, 0x8*6(%rdi)
        movq    %r12, 0x8*7(%rdi)

        leaq    64(%rdi), %rdi
        leaq    64(%rsi), %rsi
        jnz     .Loop2

        movq    (%rsp), %rbx
        movq    1*8(%rsp), %r12
        addq    $2*8, %rsp
        RET
SYM_FUNC_END(copy_page_regs)