LXR linux/arch/um/include/shared/init.h

   1#ifndef _LINUX_UML_INIT_H
   2#define _LINUX_UML_INIT_H
   3
   4/* These macros are used to mark some functions or
   5 * initialized data (doesn't apply to uninitialized data)
   6 * as `initialization' functions. The kernel can take this
   7 * as hint that the function is used only during the initialization
   8 * phase and free up used memory resources after
   9 *
  10 * Usage:
  11 * For functions:
  12 *
  13 * You should add __init immediately before the function name, like:
  14 *
  15 * static void __init initme(int x, int y)
  16 * {
  17 *    extern int z; z = x * y;
  18 * }
  19 *
  20 * If the function has a prototype somewhere, you can also add
  21 * __init between closing brace of the prototype and semicolon:
  22 *
  23 * extern int initialize_foobar_device(int, int, int) __init;
  24 *
  25 * For initialized data:
  26 * You should insert __initdata between the variable name and equal
  27 * sign followed by value, e.g.:
  28 *
  29 * static int init_variable __initdata = 0;
  30 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
  31 *
  32 * Don't forget to initialize data not at file scope, i.e. within a function,
  33 * as gcc otherwise puts the data into the bss section and not into the init
  34 * section.
  35 *
  36 * Also note, that this data cannot be "const".
  37 */
  38
  39#ifndef _LINUX_INIT_H
  40typedef int (*initcall_t)(void);
  41typedef void (*exitcall_t)(void);
  42
  43#ifndef __KERNEL__
  44#ifndef __section
  45# define __section(S) __attribute__ ((__section__(#S)))
  46#endif
  47
  48#if __GNUC__ == 3
  49
  50#if __GNUC_MINOR__ >= 3
  51# define __used                 __attribute__((__used__))
  52#else
  53# define __used                 __attribute__((__unused__))
  54#endif
  55
  56#else
  57#if __GNUC__ == 4
  58# define __used                 __attribute__((__used__))
  59#endif
  60#endif
  61
  62#else
  63#include <linux/compiler.h>
  64#endif
  65/* These are for everybody (although not all archs will actually
  66   discard it in modules) */
  67#define __init          __section(.init.text)
  68#define __initdata      __section(.init.data)
  69#define __exitdata      __section(.exit.data)
  70#define __exit_call     __used __section(.exitcall.exit)
  71
  72#ifdef MODULE
  73#define __exit          __section(.exit.text)
  74#else
  75#define __exit          __used __section(.exit.text)
  76#endif
  77
  78#endif
  79
  80#ifndef MODULE
  81struct uml_param {
  82        const char *str;
  83        int (*setup_func)(char *, int *);
  84};
  85
  86extern initcall_t __uml_initcall_start, __uml_initcall_end;
  87extern initcall_t __uml_postsetup_start, __uml_postsetup_end;
  88extern const char *__uml_help_start, *__uml_help_end;
  89#endif
  90
  91#define __uml_initcall(fn)                                              \
  92        static initcall_t __uml_initcall_##fn __uml_init_call = fn
  93
  94#define __uml_exitcall(fn)                                              \
  95        static exitcall_t __uml_exitcall_##fn __uml_exit_call = fn
  96
  97extern struct uml_param __uml_setup_start, __uml_setup_end;
  98
  99#define __uml_postsetup(fn)                                             \
 100        static initcall_t __uml_postsetup_##fn __uml_postsetup_call = fn
 101
 102#define __non_empty_string(dummyname,string)                            \
 103        struct __uml_non_empty_string_struct_##dummyname                \
 104        {                                                               \
 105                char _string[sizeof(string)-2];                         \
 106        }
 107
 108#ifndef MODULE
 109#define __uml_setup(str, fn, help...)                                   \
 110        __non_empty_string(fn ##_setup, str);                           \
 111        __uml_help(fn, help);                                           \
 112        static char __uml_setup_str_##fn[] __initdata = str;            \
 113        static struct uml_param __uml_setup_##fn __uml_init_setup = { __uml_setup_str_##fn, fn }
 114#else
 115#define __uml_setup(str, fn, help...)                                   \
 116
 117#endif
 118
 119#define __uml_help(fn, help...)                                         \
 120        __non_empty_string(fn ##__help, help);                          \
 121        static char __uml_help_str_##fn[] __initdata = help;            \
 122        static const char *__uml_help_##fn __uml_setup_help = __uml_help_str_##fn
 123
 124/*
 125 * Mark functions and data as being only used at initialization
 126 * or exit time.
 127 */
 128#define __uml_init_setup        __used __section(.uml.setup.init)
 129#define __uml_setup_help        __used __section(.uml.help.init)
 130#define __uml_init_call         __used __section(.uml.initcall.init)
 131#define __uml_postsetup_call    __used __section(.uml.postsetup.init)
 132#define __uml_exit_call         __used __section(.uml.exitcall.exit)
 133
 134#ifndef __KERNEL__
 135
 136#define __define_initcall(level,fn) \
 137        static initcall_t __initcall_##fn __used \
 138        __attribute__((__section__(".initcall" level ".init"))) = fn
 139
 140/* Userspace initcalls shouldn't depend on anything in the kernel, so we'll
 141 * make them run first.
 142 */
 143#define __initcall(fn) __define_initcall("1", fn)
 144
 145#define __exitcall(fn) static exitcall_t __exitcall_##fn __exit_call = fn
 146
 147#define __init_call     __used __section(.initcall.init)
 148
 149#endif
 150
 151#endif /* _LINUX_UML_INIT_H */
 152