arch/um/include/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 char linux_logo[] __initdata = { 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
  40 typedef int (*initcall_t)(void);
  41 typedef void (*exitcall_t)(void);
  42
  43 #define __init          __attribute__ ((__section__ (".text.init")))
  44 #define __exit          __attribute__ ((unused, __section__(".text.exit")))
  45 #define __initdata      __attribute__ ((__section__ (".data.init")))
  46
  47 #endif
  48
  49 #ifndef MODULE
  50 struct uml_param {
  51         const char *str;
  52         int (*setup_func)(char *, int *);
  53 };
  54
  55 extern initcall_t __uml_initcall_start, __uml_initcall_end;
  56 extern initcall_t __uml_postsetup_start, __uml_postsetup_end;
  57 extern const char *__uml_help_start, *__uml_help_end;
  58 #endif
  59
  60 #define __uml_initcall(fn)                                              \
  61         static initcall_t __uml_initcall_##fn __uml_init_call = fn
  62
  63 #define __uml_exitcall(fn)                                              \
  64         static exitcall_t __uml_exitcall_##fn __uml_exit_call = fn
  65
  66 extern struct uml_param __uml_setup_start, __uml_setup_end;
  67
  68 #define __uml_postsetup(fn)                                             \
  69         static initcall_t __uml_postsetup_##fn __uml_postsetup_call = fn
  70
  71 #define __non_empty_string(dummyname,string)                            \
  72         struct __uml_non_empty_string_struct_##dummyname                \
  73         {                                                               \
  74                 char _string[sizeof(string)-2];                         \
  75         }
  76
  77 #ifndef MODULE
  78 #define __uml_setup(str, fn, help...)                                   \
  79         __non_empty_string(fn ##_setup, str);                           \
  80         __uml_help(fn, help);                                           \
  81         static char __uml_setup_str_##fn[] __initdata = str;            \
  82         static struct uml_param __uml_setup_##fn __uml_init_setup = { __uml_setup_str_##fn, fn }
  83 #else
  84 #define __uml_setup(str, fn, help...)                                   \
  85
  86 #endif
  87
  88 #define __uml_help(fn, help...)                                         \
  89         __non_empty_string(fn ##__help, help);                          \
  90         static char __uml_help_str_##fn[] __initdata = help;            \
  91         static const char *__uml_help_##fn __uml_setup_help = __uml_help_str_##fn
  92
  93 /*
  94  * Mark functions and data as being only used at initialization
  95  * or exit time.
  96  */
  97 #define __uml_init_setup        __attribute__ ((unused,__section__ (".uml.setup.init")))
  98 #define __uml_setup_help        __attribute__ ((unused,__section__ (".uml.help.init")))
  99 #define __uml_init_call         __attribute__ ((unused,__section__ (".uml.initcall.init")))
 100 #define __uml_postsetup_call    __attribute__ ((unused,__section__ (".uml.postsetup.init")))
 101 #define __uml_exit_call         __attribute__ ((unused,__section__ (".uml.exitcall.exit")))
 102
 103 #endif /* _LINUX_UML_INIT_H */
 104
 105 /*
 106  * Overrides for Emacs so that we follow Linus's tabbing style.
 107  * Emacs will notice this stuff at the end of the file and automatically
 108  * adjust the settings for this buffer only.  This must remain at the end
 109  * of the file.
 110  * ---------------------------------------------------------------------------
 111  * Local variables:
 112  * c-file-style: "linux"
 113  * End:
 114  */