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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
40 typedef int (*initcall_t)(void);
41 typedef 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
61 struct uml_param {
62         const char *str;
63         int (*setup_func)(char *, int *);
64 };
65 
66 extern initcall_t __uml_initcall_start, __uml_initcall_end;
67 extern initcall_t __uml_postsetup_start, __uml_postsetup_end;
68 extern 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 
77 extern 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