init.h 4.2 KB

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