include/linux/tables.h

#ifndef _LINUX_LINKER_TABLES_H
#define _LINUX_LINKER_TABLES_H

#include <linux/sections.h>

/*
 * Linux linker tables
 *
 * Copyright (C) 2005-2009 Michael Brown <mcb30@ipxe.org>
 * Copyright (C) 2015-2016 Luis R. Rodriguez <mcgrof@kernel.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Due to this file being licensed under the GPL there is controversy over
 * whether this permits you to write a module that #includes this file
 * without placing your module under the GPL.  Please consult a lawyer for
 * advice before doing this.
 */

/* This is a trimmed version with no documentation */

#define LINKTABLE_ALIGNMENT(name)	__alignof__(__typeof__(name[0]))
#define LINKTABLE_SIZE(name)	((name##__end) - (name))
#define LINKTABLE_EMPTY(name)	(LINKTABLE_SIZE(name) == 0)
#define LINKTABLE_START(tbl)	tbl
#define LINKTABLE_END(tbl)	tbl##__end

#define LINKTABLE_ADDR_WITHIN(tbl, addr)				\
	 (addr >= (unsigned long) LINKTABLE_START(tbl) &&		\
          addr < (unsigned long) LINKTABLE_END(tbl))

#define LINKTABLE_DATA_WEAK(name, level)				\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     weak,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_DATA, name, level))))

#define LINKTABLE_TEXT_WEAK(name, level)				\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     weak,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_TEXT, name, level))))


#define LINKTABLE_RO_WEAK(name, level)					\
	const __typeof__(name[0])					\
	      __attribute__((used,					\
			     weak,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_RODATA, name, level))))

#define LINKTABLE_INIT_WEAK(name, level)					\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     weak,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_INIT, name, level))))

#define LINKTABLE_INIT_DATA_WEAK(name, level)				\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     weak,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_INIT_DATA, name, level))))

#define LINKTABLE_TEXT(name, level)					\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_TEXT, name, level))))

#define LINKTABLE_DATA(name, level)					\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_DATA, name, level))))
#define LINKTABLE_RO(name, level)					\
	const __typeof__(name[0])					\
	      __attribute__((used,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_RODATA, name, level))))

#define LINKTABLE_INIT(name, level)					\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_INIT, name, level))))
#define LINKTABLE_INIT_DATA(name, level)					\
	      __typeof__(name[0])					\
	      __attribute__((used,					\
			     __aligned__(LINKTABLE_ALIGNMENT(name)),	\
			     section(SECTION_TBL(SECTION_INIT_DATA, name, level))))

#define DECLARE_LINKTABLE_TEXT(type, name)				\
	 extern type name[], name##__end[];

#define DECLARE_LINKTABLE_DATA(type, name)				\
	 extern type name[], name##__end[];

#define DECLARE_LINKTABLE_RO(type, name)				\
	 extern const type name[], name##__end[];

#define DECLARE_LINKTABLE_INIT(type, name)				\
	 extern type name[], name##__end[];

#define DECLARE_LINKTABLE_INIT_DATA(type, name)				\
	 extern type name[], name##__end[];


#define DEFINE_LINKTABLE_TEXT(type, name)				\
	DECLARE_LINKTABLE_TEXT(type, name);				\
	LINKTABLE_TEXT_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};	\
	LTO_REFERENCE_INITCALL(name);					\
	LINKTABLE_TEXT(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};\
	LTO_REFERENCE_INITCALL(name##__end);

#define DEFINE_LINKTABLE_DATA(type, name)				\
	DECLARE_LINKTABLE_DATA(type, name);				\
	LINKTABLE_DATA_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};	\
	LTO_REFERENCE_INITCALL(name);					\
	LINKTABLE_DATA(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};\
	LTO_REFERENCE_INITCALL(name##__end);

#define DEFINE_LINKTABLE_RO(type, name)					\
	DECLARE_LINKTABLE_RO(type, name);				\
	LINKTABLE_RO_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};		\
	LTO_REFERENCE_INITCALL(name);					\
	LINKTABLE_RO(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};	\
	LTO_REFERENCE_INITCALL(name##__end);

#define DEFINE_LINKTABLE_INIT(type, name)					\
	DECLARE_LINKTABLE_INIT(type, name);					\
	LINKTABLE_INIT_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};		\
	LTO_REFERENCE_INITCALL(name);						\
	LINKTABLE_INIT(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};	\
	LTO_REFERENCE_INITCALL(name##__end);

#define DEFINE_LINKTABLE_INIT_DATA(type, name)					\
	DECLARE_LINKTABLE_INIT_DATA(type, name);					\
	LINKTABLE_INIT_DATA_WEAK(name, ) VMLINUX_SYMBOL(name)[0] = {};		\
	LTO_REFERENCE_INITCALL(name);						\
	LINKTABLE_INIT_DATA(name, ~) VMLINUX_SYMBOL(name##__end)[0] = {};	\
	LTO_REFERENCE_INITCALL(name##__end);

#define LINKTABLE_FOR_EACH(pointer, tbl)				\
	for (pointer = LINKTABLE_START(tbl);				\
	     pointer < LINKTABLE_END(tbl);				\
	     pointer++)

#define LINKTABLE_RUN_ALL(tbl, func, args...)				\
do {									\
	size_t i;							\
	for (i = 0; i < LINKTABLE_SIZE(tbl); i++)			\
		(tbl[i]).func (args);					\
} while (0);

#define LINKTABLE_RUN_ERR(tbl, func, args...)				\
({									\
	size_t i;							\
	int err = 0;							\
	for (i = 0; !err && i < LINKTABLE_SIZE(tbl); i++)		\
		err = (tbl[i]).func (args);				\
		err; \
})

#endif /* _LINUX_LINKER_TABLES_H */