[linux-2.6-block.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.
 */

#define __VMLINUX_SYMBOL(x) x
#define __VMLINUX_SYMBOL_STR(x) #x

/* 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

#if defined(__KERNEL__) && !defined(__GENKSYMS__)
#ifdef CONFIG_MODVERSIONS
/* Mark the CRC weak since genksyms apparently decides not to
 * generate a checksums for some symbols */
#if defined(CONFIG_MODULE_REL_CRCS)
#define __CRC_SYMBOL(sym, sec)						\
	asm("	.section \"___kcrctab" sec "+" #sym "\", \"a\"	\n"	\
	    "	.weak	__crc_" #sym "				\n"	\
	    "	.long	__crc_" #sym " - .			\n"	\
	    "	.previous					\n");
#else
#define __CRC_SYMBOL(sym, sec)						\
	asm("	.section \"___kcrctab" sec "+" #sym "\", \"a\"	\n"	\
	    "	.weak	__crc_" #sym "				\n"	\
	    "	.long	__crc_" #sym "				\n"	\
	    "	.previous					\n");
#endif
#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)))	\
	= #sym;								\
	static const struct kernel_symbol __ksymtab_##sym		\
	__used								\
	__attribute__((section("___ksymtab" sec "+" #sym), used))	\
	= { (unsigned long)&sym, __kstrtab_##sym }

#if defined(__KSYM_DEPS__)

/*
 * For fine grained build dependencies, we want to tell the build system
 * about each possible exported symbol even if they're not actually exported.
 * We use a string pattern that is unlikely to be valid code that the build
 * system filters out from the preprocessor output (see ksym_dep_filter
 * in scripts/Kbuild.include).
 */
#define __EXPORT_SYMBOL(sym, sec)	=== __KSYM_##sym ===

#elif defined(CONFIG_TRIM_UNUSED_KSYMS)

#include <generated/autoksyms.h>

#define __EXPORT_SYMBOL(sym, sec)				\
	__cond_export_sym(sym, sec, __is_defined(__KSYM_##sym))
#define __cond_export_sym(sym, sec, conf)			\
	___cond_export_sym(sym, sec, conf)
#define ___cond_export_sym(sym, sec, enabled)			\
	__cond_export_sym_##enabled(sym, sec)
#define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec)
#define __cond_export_sym_0(sym, sec) /* nothing */

#else
#define __EXPORT_SYMBOL ___EXPORT_SYMBOL
#endif

#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
f5016932 PG	2	#define _LINUX_EXPORT_H
b67067f1	3
f5016932 PG	4	/*
	5	* Export symbols from the kernel to modules. Forked from module.h
	6	* to reduce the amount of pointless cruft we feed to gcc when only
	7	* exporting a simple symbol or two.
	8	*
b92021b0 RR	9	* Try not to add #includes here. It slows compilation and makes kernel
b92021b0 RR	10	* hackers place grumpy comments in header files.
f5016932 PG	11	*/
f5016932 PG	12
b92021b0 RR	13	#define __VMLINUX_SYMBOL(x) x
b92021b0 RR	14	#define __VMLINUX_SYMBOL_STR(x) #x
f5016932	15
b92021b0 RR	16	/* Indirect, so macros are expanded before pasting. */
	17	#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
	18	#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
	19
	20	#ifndef __ASSEMBLY__
f5016932 PG	21	struct kernel_symbol
	22	{
	23	unsigned long value;
	24	const char *name;
	25	};
	26
	27	#ifdef MODULE
	28	extern struct module __this_module;
	29	#define THIS_MODULE (&__this_module)
	30	#else
	31	#define THIS_MODULE ((struct module *)0)
	32	#endif
	33
	34	#ifdef CONFIG_MODULES
	35
f2355416	36	#if defined(__KERNEL__) && !defined(__GENKSYMS__)
f5016932 PG	37	#ifdef CONFIG_MODVERSIONS
	38	/* Mark the CRC weak since genksyms apparently decides not to
	39	* generate a checksums for some symbols */
71810db2 AB	40	#if defined(CONFIG_MODULE_REL_CRCS)
	41	#define __CRC_SYMBOL(sym, sec) \
	42	asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \
94e58e0a MY	43	" .weak __crc_" #sym " \n" \
94e58e0a MY	44	" .long __crc_" #sym " - . \n" \
71810db2	45	" .previous \n");
f5016932	46	#else
71810db2 AB	47	#define __CRC_SYMBOL(sym, sec) \
71810db2 AB	48	asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \
94e58e0a MY	49	" .weak __crc_" #sym " \n" \
94e58e0a MY	50	" .long __crc_" #sym " \n" \
71810db2 AB	51	" .previous \n");
	52	#endif
	53	#else
f5016932 PG	54	#define __CRC_SYMBOL(sym, sec)
	55	#endif
	56
	57	/* For every exported symbol, place a struct in the __ksymtab section */
b67067f1 NP	58	#define ___EXPORT_SYMBOL(sym, sec) \
	59	extern typeof(sym) sym; \
	60	__CRC_SYMBOL(sym, sec) \
	61	static const char __kstrtab_##sym[] \
	62	__attribute__((section("__ksymtab_strings"), aligned(1))) \
94e58e0a	63	= #sym; \
b67067f1 NP	64	static const struct kernel_symbol __ksymtab_##sym \
	65	__used \
	66	__attribute__((section("___ksymtab" sec "+" #sym), used)) \
f5016932 PG	67	= { (unsigned long)&sym, __kstrtab_##sym }
f5016932 PG	68
c1a95fda NP	69	#if defined(__KSYM_DEPS__)
	70
	71	/*
	72	* For fine grained build dependencies, we want to tell the build system
	73	* about each possible exported symbol even if they're not actually exported.
	74	* We use a string pattern that is unlikely to be valid code that the build
	75	* system filters out from the preprocessor output (see ksym_dep_filter
	76	* in scripts/Kbuild.include).
	77	*/
	78	#define __EXPORT_SYMBOL(sym, sec) === __KSYM_##sym ===
	79
	80	#elif defined(CONFIG_TRIM_UNUSED_KSYMS)
f2355416	81
f2355416 NP	82	#include <generated/autoksyms.h>
	83
	84	#define __EXPORT_SYMBOL(sym, sec) \
6023d236	85	__cond_export_sym(sym, sec, __is_defined(__KSYM_##sym))
f2355416 NP	86	#define __cond_export_sym(sym, sec, conf) \
	87	___cond_export_sym(sym, sec, conf)
	88	#define ___cond_export_sym(sym, sec, enabled) \
	89	__cond_export_sym_##enabled(sym, sec)
	90	#define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec)
	91	#define __cond_export_sym_0(sym, sec) /* nothing */
	92
	93	#else
	94	#define __EXPORT_SYMBOL ___EXPORT_SYMBOL
	95	#endif
	96
f5016932 PG	97	#define EXPORT_SYMBOL(sym) \
	98	__EXPORT_SYMBOL(sym, "")
	99
	100	#define EXPORT_SYMBOL_GPL(sym) \
	101	__EXPORT_SYMBOL(sym, "_gpl")
	102
	103	#define EXPORT_SYMBOL_GPL_FUTURE(sym) \
	104	__EXPORT_SYMBOL(sym, "_gpl_future")
	105
	106	#ifdef CONFIG_UNUSED_SYMBOLS
	107	#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
	108	#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
	109	#else
	110	#define EXPORT_UNUSED_SYMBOL(sym)
	111	#define EXPORT_UNUSED_SYMBOL_GPL(sym)
	112	#endif
	113
	114	#endif /* __GENKSYMS__ */
	115
	116	#else /* !CONFIG_MODULES... */
	117
	118	#define EXPORT_SYMBOL(sym)
	119	#define EXPORT_SYMBOL_GPL(sym)
	120	#define EXPORT_SYMBOL_GPL_FUTURE(sym)
	121	#define EXPORT_UNUSED_SYMBOL(sym)
	122	#define EXPORT_UNUSED_SYMBOL_GPL(sym)
	123
	124	#endif /* CONFIG_MODULES */
b92021b0	125	#endif /* !__ASSEMBLY__ */
f5016932 PG	126
f5016932 PG	127	#endif /* _LINUX_EXPORT_H */