1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_UML_INIT_H 3 #define _LINUX_UML_INIT_H 4 5 /* These macros are used to mark some functions or 6 * initialized data (doesn't apply to uninitialized data) 7 * as `initialization' functions. The kernel can take this 8 * as hint that the function is used only during the initialization 9 * phase and free up used memory resources after 10 * 11 * Usage: 12 * For functions: 13 * 14 * You should add __init immediately before the function name, like: 15 * 16 * static void __init initme(int x, int y) 17 * { 18 * extern int z; z = x * y; 19 * } 20 * 21 * If the function has a prototype somewhere, you can also add 22 * __init between closing brace of the prototype and semicolon: 23 * 24 * extern int initialize_foobar_device(int, int, int) __init; 25 * 26 * For initialized data: 27 * You should insert __initdata between the variable name and equal 28 * sign followed by value, e.g.: 29 * 30 * static int init_variable __initdata = 0; 31 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... }; 32 * 33 * Don't forget to initialize data not at file scope, i.e. within a function, 34 * as gcc otherwise puts the data into the bss section and not into the init 35 * section. 36 * 37 * Also note, that this data cannot be "const". 38 */ 39 40 #ifndef _LINUX_INIT_H 41 typedef int (*initcall_t)(void); 42 typedef void (*exitcall_t)(void); 43 44 #include <linux/compiler_types.h> 45 46 /* These are for everybody (although not all archs will actually 47 discard it in modules) */ 48 #define __init __section(.init.text) 49 #define __initdata __section(.init.data) 50 #define __exitdata __section(.exit.data) 51 #define __exit_call __used __section(.exitcall.exit) 52 53 #ifdef MODULE 54 #define __exit __section(.exit.text) 55 #else 56 #define __exit __used __section(.exit.text) 57 #endif 58 59 #endif 60 61 #ifndef MODULE 62 struct uml_param { 63 const char *str; 64 int (*setup_func)(char *, int *); 65 }; 66 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_exitcall(fn) \ 72 static exitcall_t __uml_exitcall_##fn __uml_exit_call = fn 73 74 extern struct uml_param __uml_setup_start, __uml_setup_end; 75 76 #define __uml_postsetup(fn) \ 77 static initcall_t __uml_postsetup_##fn __uml_postsetup_call = fn 78 79 #define __non_empty_string(dummyname,string) \ 80 struct __uml_non_empty_string_struct_##dummyname \ 81 { \ 82 char _string[sizeof(string)-2]; \ 83 } 84 85 #ifndef MODULE 86 #define __uml_setup(str, fn, help...) \ 87 __non_empty_string(fn ##_setup, str); \ 88 __uml_help(fn, help); \ 89 static char __uml_setup_str_##fn[] __initdata = str; \ 90 static struct uml_param __uml_setup_##fn __uml_init_setup = { __uml_setup_str_##fn, fn } 91 #else 92 #define __uml_setup(str, fn, help...) \ 93 94 #endif 95 96 #define __uml_help(fn, help...) \ 97 __non_empty_string(fn ##__help, help); \ 98 static char __uml_help_str_##fn[] __initdata = help; \ 99 static const char *__uml_help_##fn __uml_setup_help = __uml_help_str_##fn 100 101 /* 102 * Mark functions and data as being only used at initialization 103 * or exit time. 104 */ 105 #define __uml_init_setup __used __section(.uml.setup.init) 106 #define __uml_setup_help __used __section(.uml.help.init) 107 #define __uml_postsetup_call __used __section(.uml.postsetup.init) 108 #define __uml_exit_call __used __section(.uml.exitcall.exit) 109 110 #ifdef __UM_HOST__ 111 112 #define __define_initcall(level,fn) \ 113 static initcall_t __initcall_##fn __used \ 114 __attribute__((__section__(".initcall" level ".init"))) = fn 115 116 /* Userspace initcalls shouldn't depend on anything in the kernel, so we'll 117 * make them run first. 118 */ 119 #define __initcall(fn) __define_initcall("1", fn) 120 121 #define __exitcall(fn) static exitcall_t __exitcall_##fn __exit_call = fn 122 123 #define __init_call __used __section(.initcall.init) 124 125 #endif 126 127 #endif /* _LINUX_UML_INIT_H */ 128