[mirror_ubuntu-artful-kernel.git] / include / linux / export.h

#ifndef _LINUX_EXPORT_H
#define _LINUX_EXPORT_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.
 */

/* Some toolchains use a `_' prefix for all user symbols. */
#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
#define __VMLINUX_SYMBOL(x) _##x
#define __VMLINUX_SYMBOL_STR(x) "_" #x
#else
#define __VMLINUX_SYMBOL(x) x
#define __VMLINUX_SYMBOL_STR(x) #x
#endif

/* Indirect, so macros are expanded before pasting. */
#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)

#ifndef __ASSEMBLY__
struct kernel_symbol
{
	unsigned long value;
	const char *name;
};

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

#ifdef CONFIG_MODULES

#ifndef __GENKSYMS__
#ifdef CONFIG_MODVERSIONS
/* Mark the CRC weak since genksyms apparently decides not to
 * generate a checksums for some symbols */
#define __CRC_SYMBOL(sym, sec)					\
	extern __visible void *__crc_##sym __attribute__((weak));		\
	static const unsigned long __kcrctab_##sym		\
	__used							\
	__attribute__((section("___kcrctab" sec "+" #sym), unused))	\
	= (unsigned long) &__crc_##sym;
#else
#define __CRC_SYMBOL(sym, sec)
#endif

/* For every exported symbol, place a struct in the __ksymtab section */
#define __EXPORT_SYMBOL(sym, sec)				\
	extern typeof(sym) sym;					\
	__CRC_SYMBOL(sym, sec)					\
	static const char __kstrtab_##sym[]			\
	__attribute__((section("__ksymtab_strings"), aligned(1))) \
	= VMLINUX_SYMBOL_STR(sym);				\
	__visible const struct kernel_symbol __ksymtab_##sym	\
	__used							\
	__attribute__((section("___ksymtab" sec "+" #sym), unused))	\
	= { (unsigned long)&sym, __kstrtab_##sym }

#define EXPORT_SYMBOL(sym)					\
	__EXPORT_SYMBOL(sym, "")

#define EXPORT_SYMBOL_GPL(sym)					\
	__EXPORT_SYMBOL(sym, "_gpl")

#define EXPORT_SYMBOL_GPL_FUTURE(sym)				\
	__EXPORT_SYMBOL(sym, "_gpl_future")

#ifdef CONFIG_UNUSED_SYMBOLS
#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
#else
#define EXPORT_UNUSED_SYMBOL(sym)
#define EXPORT_UNUSED_SYMBOL_GPL(sym)
#endif

#endif	/* __GENKSYMS__ */

#else /* !CONFIG_MODULES... */

#define EXPORT_SYMBOL(sym)
#define EXPORT_SYMBOL_GPL(sym)
#define EXPORT_SYMBOL_GPL_FUTURE(sym)
#define EXPORT_UNUSED_SYMBOL(sym)
#define EXPORT_UNUSED_SYMBOL_GPL(sym)

#endif /* CONFIG_MODULES */
#endif /* !__ASSEMBLY__ */

#endif /* _LINUX_EXPORT_H */
Commit	Line	Data
f5016932 PG	1	#ifndef _LINUX_EXPORT_H
	2	#define _LINUX_EXPORT_H
	3	/*
	4	* Export symbols from the kernel to modules. Forked from module.h
	5	* to reduce the amount of pointless cruft we feed to gcc when only
	6	* exporting a simple symbol or two.
	7	*
b92021b0 RR	8	* Try not to add #includes here. It slows compilation and makes kernel
b92021b0 RR	9	* hackers place grumpy comments in header files.
f5016932 PG	10	*/
	11
	12	/* Some toolchains use a `_' prefix for all user symbols. */
b92021b0 RR	13	#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
	14	#define __VMLINUX_SYMBOL(x) _##x
	15	#define __VMLINUX_SYMBOL_STR(x) "_" #x
f5016932	16	#else
b92021b0 RR	17	#define __VMLINUX_SYMBOL(x) x
b92021b0 RR	18	#define __VMLINUX_SYMBOL_STR(x) #x
f5016932 PG	19	#endif
f5016932 PG	20
b92021b0 RR	21	/* Indirect, so macros are expanded before pasting. */
	22	#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
	23	#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
	24
	25	#ifndef __ASSEMBLY__
f5016932 PG	26	struct kernel_symbol
	27	{
	28	unsigned long value;
	29	const char *name;
	30	};
	31
	32	#ifdef MODULE
	33	extern struct module __this_module;
	34	#define THIS_MODULE (&__this_module)
	35	#else
	36	#define THIS_MODULE ((struct module *)0)
	37	#endif
	38
	39	#ifdef CONFIG_MODULES
	40
	41	#ifndef __GENKSYMS__
	42	#ifdef CONFIG_MODVERSIONS
	43	/* Mark the CRC weak since genksyms apparently decides not to
	44	* generate a checksums for some symbols */
	45	#define __CRC_SYMBOL(sym, sec) \
e0f244c6	46	extern __visible void *__crc_##sym __attribute__((weak)); \
f5016932 PG	47	static const unsigned long __kcrctab_##sym \
	48	__used \
	49	__attribute__((section("___kcrctab" sec "+" #sym), unused)) \
	50	= (unsigned long) &__crc_##sym;
	51	#else
	52	#define __CRC_SYMBOL(sym, sec)
	53	#endif
	54
	55	/* For every exported symbol, place a struct in the __ksymtab section */
	56	#define __EXPORT_SYMBOL(sym, sec) \
	57	extern typeof(sym) sym; \
	58	__CRC_SYMBOL(sym, sec) \
	59	static const char __kstrtab_##sym[] \
	60	__attribute__((section("__ksymtab_strings"), aligned(1))) \
b92021b0	61	= VMLINUX_SYMBOL_STR(sym); \
e0f244c6	62	__visible const struct kernel_symbol __ksymtab_##sym \
f5016932 PG	63	__used \
	64	__attribute__((section("___ksymtab" sec "+" #sym), unused)) \
	65	= { (unsigned long)&sym, __kstrtab_##sym }
	66
	67	#define EXPORT_SYMBOL(sym) \
	68	__EXPORT_SYMBOL(sym, "")
	69
	70	#define EXPORT_SYMBOL_GPL(sym) \
	71	__EXPORT_SYMBOL(sym, "_gpl")
	72
	73	#define EXPORT_SYMBOL_GPL_FUTURE(sym) \
	74	__EXPORT_SYMBOL(sym, "_gpl_future")
	75
	76	#ifdef CONFIG_UNUSED_SYMBOLS
	77	#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
	78	#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
	79	#else
	80	#define EXPORT_UNUSED_SYMBOL(sym)
	81	#define EXPORT_UNUSED_SYMBOL_GPL(sym)
	82	#endif
	83
	84	#endif /* __GENKSYMS__ */
	85
	86	#else /* !CONFIG_MODULES... */
	87
	88	#define EXPORT_SYMBOL(sym)
	89	#define EXPORT_SYMBOL_GPL(sym)
	90	#define EXPORT_SYMBOL_GPL_FUTURE(sym)
	91	#define EXPORT_UNUSED_SYMBOL(sym)
	92	#define EXPORT_UNUSED_SYMBOL_GPL(sym)
	93
	94	#endif /* CONFIG_MODULES */
b92021b0	95	#endif /* !__ASSEMBLY__ */
f5016932 PG	96
f5016932 PG	97	#endif /* _LINUX_EXPORT_H */