/* 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>

/*
 * 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.
 */

#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

#ifdef CONFIG_GENDWARFKSYMS
/*
 * With CONFIG_GENDWARFKSYMS, ensure the compiler emits debugging
 * information for all exported symbols, including those defined in
 * different TUs, by adding a __gendwarfksyms_ptr_<symbol> pointer
 * that's discarded during the final link.
 */
#define __GENDWARFKSYMS_EXPORT(sym)                             \
        static typeof(sym) *__gendwarfksyms_ptr_##sym __used    \
                __section(".discard.gendwarfksyms") = &sym;
#else
#define __GENDWARFKSYMS_EXPORT(sym)
#endif

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

#endif

#ifdef DEFAULT_SYMBOL_NAMESPACE
#define _EXPORT_SYMBOL(sym, license)    __EXPORT_SYMBOL(sym, license, 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, "", ns)
#define EXPORT_SYMBOL_NS_GPL(sym, ns)   __EXPORT_SYMBOL(sym, "GPL", ns)

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

#endif /* _LINUX_EXPORT_H */