/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef _LINUX_EXPORT_H
#define _LINUX_EXPORT_H

#include <linux/compiler.h>
#include <linux/linkage.h>
#include <linux/stringify.h>

/*
 * Export symbols from the kernel to modules.  Forked from module.h
 * to reduce the amount of pointless cruft we feed to gcc when only
 * exporting a simple symbol or two.
 *
 * Try not to add #includes here.  It slows compilation and makes kernel
 * hackers place grumpy comments in header files.
 */

/*
 * This comment block is used by fixdep. Please do not remove.
 *
 * When CONFIG_MODVERSIONS is changed from n to y, all source files having
 * EXPORT_SYMBOL variants must be re-compiled because genksyms is run as a
 * side effect of the *.o build rule.
 */

#ifndef __ASSEMBLY__
#ifdef MODULE
extern struct module __this_module;
#define THIS_MODULE (&__this_module)
#else
#define THIS_MODULE ((struct module *)0)
#endif
#endif /* __ASSEMBLY__ */

#ifdef CONFIG_64BIT
#define __EXPORT_SYMBOL_REF(sym)            \
    .balign 8                ASM_NL    \
    .quad sym
#else
#define __EXPORT_SYMBOL_REF(sym)            \
    .balign 4                ASM_NL    \
    .long sym
#endif

/*
 * LLVM integrated assembler cam merge adjacent string literals (like
 * C and GNU-as) passed to '.ascii', but not to '.asciz' and chokes on:
 *
 *   .asciz "MODULE_" "kvm" ;
 */
#define ___EXPORT_SYMBOL(sym, license, ns...)        \
    .section ".export_symbol","a"        ASM_NL    \
    __export_symbol_##sym:            ASM_NL    \
        .asciz license            ASM_NL    \
        .ascii ns "\0"            ASM_NL    \
        __EXPORT_SYMBOL_REF(sym)    ASM_NL    \
    .previous

#if defined(__DISABLE_EXPORTS)

/*
 * Allow symbol exports to be disabled completely so that C code may
 * be reused in other execution contexts such as the UEFI stub or the
 * decompressor.
 */
#define __EXPORT_SYMBOL(sym, license, ns)

#elif defined(__GENKSYMS__)

#define __EXPORT_SYMBOL(sym, license, ns)    __GENKSYMS_EXPORT_SYMBOL(sym)

#elif defined(__ASSEMBLY__)

#define __EXPORT_SYMBOL(sym, license, ns) \
    ___EXPORT_SYMBOL(sym, license, ns)

#else

#define __EXPORT_SYMBOL(sym, license, ns)            \
/*    extern typeof(sym) sym;                    */\
    __ADDRESSABLE(sym)                    \
    asm(__stringify(___EXPORT_SYMBOL(sym, license, ns)))

#endif

#ifdef DEFAULT_SYMBOL_NAMESPACE
#define _EXPORT_SYMBOL(sym, license)    __EXPORT_SYMBOL(sym, license, __stringify(DEFAULT_SYMBOL_NAMESPACE))
#else
#define _EXPORT_SYMBOL(sym, license)    __EXPORT_SYMBOL(sym, license, "")
#endif

#define EXPORT_SYMBOL(sym)        _EXPORT_SYMBOL(sym, "")
#define EXPORT_SYMBOL_GPL(sym)        _EXPORT_SYMBOL(sym, "GPL")
#define EXPORT_SYMBOL_NS(sym, ns)    __EXPORT_SYMBOL(sym, "", __stringify(ns))
#define EXPORT_SYMBOL_NS_GPL(sym, ns)    __EXPORT_SYMBOL(sym, "GPL", __stringify(ns))

#define EXPORT_SYMBOL_GPL_FOR_MODULES(sym, mods) __EXPORT_SYMBOL(sym, "GPL", "module:" mods)

#endif /* _LINUX_EXPORT_H */