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#include <linux/compiler.h>
  44
  45/* These are for everybody (although not all archs will actually
  46   discard it in modules) */
  47#define __init          __section(.init.text)
  48#define __initdata      __section(.init.data)
  49#define __exitdata      __section(.exit.data)
  50#define __exit_call     __used __section(.exitcall.exit)
  51
  52#ifdef MODULE
  53#define __exit          __section(.exit.text)
  54#else
  55#define __exit          __used __section(.exit.text)
  56#endif
  57
  58#endif
  59
  60#ifndef MODULE
  61struct uml_param {
  62        const char *str;
  63        int (*setup_func)(char *, int *);
  64};
  65
  66extern initcall_t __uml_initcall_start, __uml_initcall_end;
  67extern initcall_t __uml_postsetup_start, __uml_postsetup_end;
  68extern const char *__uml_help_start, *__uml_help_end;
  69#endif
  70
  71#define __uml_initcall(fn)                                              \
  72        static initcall_t __uml_initcall_##fn __uml_init_call = fn
  73
  74#define __uml_exitcall(fn)                                              \
  75        static exitcall_t __uml_exitcall_##fn __uml_exit_call = fn
  76
  77extern struct uml_param __uml_setup_start, __uml_setup_end;
  78
  79#define __uml_postsetup(fn)                                             \
  80        static initcall_t __uml_postsetup_##fn __uml_postsetup_call = fn
  81
  82#define __non_empty_string(dummyname,string)                            \
  83        struct __uml_non_empty_string_struct_##dummyname                \
  84        {                                                               \
  85                char _string[sizeof(string)-2];                         \
  86        }
  87
  88#ifndef MODULE
  89#define __uml_setup(str, fn, help...)                                   \
  90        __non_empty_string(fn ##_setup, str);                           \
  91        __uml_help(fn, help);                                           \
  92        static char __uml_setup_str_##fn[] __initdata = str;            \
  93        static struct uml_param __uml_setup_##fn __uml_init_setup = { __uml_setup_str_##fn, fn }
  94#else
  95#define __uml_setup(str, fn, help...)                                   \
  96
  97#endif
  98
  99#define __uml_help(fn, help...)                                         \
 100        __non_empty_string(fn ##__help, help);                          \
 101        static char __uml_help_str_##fn[] __initdata = help;            \
 102        static const char *__uml_help_##fn __uml_setup_help = __uml_help_str_##fn
 103
 104/*
 105 * Mark functions and data as being only used at initialization
 106 * or exit time.
 107 */
 108#define __uml_init_setup        __used __section(.uml.setup.init)
 109#define __uml_setup_help        __used __section(.uml.help.init)
 110#define __uml_init_call         __used __section(.uml.initcall.init)
 111#define __uml_postsetup_call    __used __section(.uml.postsetup.init)
 112#define __uml_exit_call         __used __section(.uml.exitcall.exit)
 113
 114#ifdef __UM_HOST__
 115
 116#define __define_initcall(level,fn) \
 117        static initcall_t __initcall_##fn __used \
 118        __attribute__((__section__(".initcall" level ".init"))) = fn
 119
 120/* Userspace initcalls shouldn't depend on anything in the kernel, so we'll
 121 * make them run first.
 122 */
 123#define __initcall(fn) __define_initcall("1", fn)
 124
 125#define __exitcall(fn) static exitcall_t __exitcall_##fn __exit_call = fn
 126
 127#define __init_call     __used __section(.initcall.init)
 128
 129#endif
 130
 131#endif /* _LINUX_UML_INIT_H */
 132