/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  linux/arch/arm/lib/copy_from_user.S
 *
 *  Author:     Nicolas Pitre
 *  Created:    Sep 29, 2005
 *  Copyright:  MontaVista Software, Inc.
 */

#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/unwind.h>

/*
 * Prototype:
 *
 *      size_t arm_copy_from_user(void *to, const void *from, size_t n)
 *
 * Purpose:
 *
 *      copy a block to kernel memory from user memory
 *
 * Params:
 *
 *      to = kernel memory
 *      from = user memory
 *      n = number of bytes to copy
 *
 * Return value:
 *
 *      Number of bytes NOT copied.
 */

#ifdef CONFIG_CPU_USE_DOMAINS

#ifndef CONFIG_THUMB2_KERNEL
#define LDR1W_SHIFT     0
#else
#define LDR1W_SHIFT     1
#endif

        .macro ldr1w ptr reg abort
        ldrusr  \reg, \ptr, 4, abort=\abort
        .endm

        .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
        ldr1w \ptr, \reg1, \abort
        ldr1w \ptr, \reg2, \abort
        ldr1w \ptr, \reg3, \abort
        ldr1w \ptr, \reg4, \abort
        .endm

        .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
        ldr4w \ptr, \reg1, \reg2, \reg3, \reg4, \abort
        ldr4w \ptr, \reg5, \reg6, \reg7, \reg8, \abort
        .endm

#else

#define LDR1W_SHIFT     0

        .macro ldr1w ptr reg abort
        USERL(\abort, W(ldr) \reg, [\ptr], #4)
        .endm

        .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
        USERL(\abort, ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4})
        .endm

        .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
        USERL(\abort, ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8})
        .endm

#endif /* CONFIG_CPU_USE_DOMAINS */

        .macro ldr1b ptr reg cond=al abort
        ldrusr  \reg, \ptr, 1, \cond, abort=\abort
        .endm

#define STR1W_SHIFT     0

        .macro str1w ptr reg abort
        W(str) \reg, [\ptr], #4
        .endm

        .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
        stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
        .endm

        .macro str1b ptr reg cond=al abort
        strb\cond \reg, [\ptr], #1
        .endm

        .macro enter regs:vararg
        mov     r3, #0
UNWIND( .save   {r0, r2, r3, \regs}             )
        stmdb   sp!, {r0, r2, r3, \regs}
        .endm

        .macro exit regs:vararg
        add     sp, sp, #8
        ldmfd   sp!, {r0, \regs}
        .endm

        .text

ENTRY(arm_copy_from_user)
#ifdef CONFIG_CPU_SPECTRE
        ldr     r3, =TASK_SIZE
        uaccess_mask_range_ptr r1, r2, r3, ip
#endif

#include "copy_template.S"

ENDPROC(arm_copy_from_user)

        .pushsection .text.fixup,"ax"
        .align 0
        copy_abort_preamble
        ldmfd   sp!, {r1, r2, r3}
        sub     r0, r0, r1
        rsb     r0, r0, r2
        copy_abort_end
        .popsection