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Paul Gortmakerf5016932011-05-23 14:11:39 -04001#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 *
Rusty Russellb92021b2013-03-15 15:04:17 +10308 * Try not to add #includes here. It slows compilation and makes kernel
9 * hackers place grumpy comments in header files.
Paul Gortmakerf5016932011-05-23 14:11:39 -040010 */
11
12/* Some toolchains use a `_' prefix for all user symbols. */
Rusty Russellb92021b2013-03-15 15:04:17 +103013#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
14#define __VMLINUX_SYMBOL(x) _##x
15#define __VMLINUX_SYMBOL_STR(x) "_" #x
Paul Gortmakerf5016932011-05-23 14:11:39 -040016#else
Rusty Russellb92021b2013-03-15 15:04:17 +103017#define __VMLINUX_SYMBOL(x) x
18#define __VMLINUX_SYMBOL_STR(x) #x
Paul Gortmakerf5016932011-05-23 14:11:39 -040019#endif
20
Rusty Russellb92021b2013-03-15 15:04:17 +103021/* 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__
Paul Gortmakerf5016932011-05-23 14:11:39 -040026struct kernel_symbol
27{
28 unsigned long value;
29 const char *name;
30};
31
32#ifdef MODULE
33extern 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) \
Andi Kleene0f244c2013-10-23 10:57:58 +103046 extern __visible void *__crc_##sym __attribute__((weak)); \
Paul Gortmakerf5016932011-05-23 14:11:39 -040047 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))) \
Rusty Russellb92021b2013-03-15 15:04:17 +103061 = VMLINUX_SYMBOL_STR(sym); \
Andi Kleene0f244c2013-10-23 10:57:58 +103062 __visible const struct kernel_symbol __ksymtab_##sym \
Paul Gortmakerf5016932011-05-23 14:11:39 -040063 __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 */
Rusty Russellb92021b2013-03-15 15:04:17 +103095#endif /* !__ASSEMBLY__ */
Paul Gortmakerf5016932011-05-23 14:11:39 -040096
97#endif /* _LINUX_EXPORT_H */