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1da177e4 LT |
1 | #ifndef _LINUX_INIT_H |
2 | #define _LINUX_INIT_H | |
3 | ||
1da177e4 | 4 | #include <linux/compiler.h> |
2329abfa | 5 | #include <linux/types.h> |
1da177e4 LT |
6 | |
7 | /* These macros are used to mark some functions or | |
8 | * initialized data (doesn't apply to uninitialized data) | |
9 | * as `initialization' functions. The kernel can take this | |
10 | * as hint that the function is used only during the initialization | |
11 | * phase and free up used memory resources after | |
12 | * | |
13 | * Usage: | |
14 | * For functions: | |
15 | * | |
16 | * You should add __init immediately before the function name, like: | |
17 | * | |
18 | * static void __init initme(int x, int y) | |
19 | * { | |
20 | * extern int z; z = x * y; | |
21 | * } | |
22 | * | |
23 | * If the function has a prototype somewhere, you can also add | |
24 | * __init between closing brace of the prototype and semicolon: | |
25 | * | |
26 | * extern int initialize_foobar_device(int, int, int) __init; | |
27 | * | |
28 | * For initialized data: | |
65321547 GU |
29 | * You should insert __initdata or __initconst between the variable name |
30 | * and equal sign followed by value, e.g.: | |
1da177e4 LT |
31 | * |
32 | * static int init_variable __initdata = 0; | |
ae52bb23 | 33 | * static const char linux_logo[] __initconst = { 0x32, 0x36, ... }; |
1da177e4 LT |
34 | * |
35 | * Don't forget to initialize data not at file scope, i.e. within a function, | |
36 | * as gcc otherwise puts the data into the bss section and not into the init | |
37 | * section. | |
1da177e4 LT |
38 | */ |
39 | ||
40 | /* These are for everybody (although not all archs will actually | |
41 | discard it in modules) */ | |
fed1939c | 42 | #define __init __section(.init.text) __cold notrace |
f3fe866d | 43 | #define __initdata __section(.init.data) |
754b7b63 | 44 | #define __initconst __constsection(.init.rodata) |
f3fe866d | 45 | #define __exitdata __section(.exit.data) |
3ff6eecc | 46 | #define __exit_call __used __section(.exitcall.exit) |
1da177e4 | 47 | |
754b7b63 AK |
48 | /* |
49 | * Some architecture have tool chains which do not handle rodata attributes | |
50 | * correctly. For those disable special sections for const, so that other | |
51 | * architectures can annotate correctly. | |
52 | */ | |
53 | #ifdef CONFIG_BROKEN_RODATA | |
54 | #define __constsection(x) | |
55 | #else | |
56 | #define __constsection(x) __section(x) | |
57 | #endif | |
58 | ||
5ea08178 MN |
59 | /* |
60 | * modpost check for section mismatches during the kernel build. | |
0e0d314e SR |
61 | * A section mismatch happens when there are references from a |
62 | * code or data section to an init section (both code or data). | |
63 | * The init sections are (for most archs) discarded by the kernel | |
64 | * when early init has completed so all such references are potential bugs. | |
65 | * For exit sections the same issue exists. | |
5ea08178 | 66 | * |
0e0d314e | 67 | * The following markers are used for the cases where the reference to |
312b1485 | 68 | * the *init / *exit section (code or data) is valid and will teach |
5ea08178 MN |
69 | * modpost not to issue a warning. Intended semantics is that a code or |
70 | * data tagged __ref* can reference code or data from init section without | |
71 | * producing a warning (of course, no warning does not mean code is | |
72 | * correct, so optimally document why the __ref is needed and why it's OK). | |
73 | * | |
74 | * The markers follow same syntax rules as __init / __initdata. | |
75 | */ | |
312b1485 SR |
76 | #define __ref __section(.ref.text) noinline |
77 | #define __refdata __section(.ref.data) | |
754b7b63 | 78 | #define __refconst __constsection(.ref.rodata) |
312b1485 | 79 | |
1da177e4 | 80 | #ifdef MODULE |
eb8f6890 | 81 | #define __exitused |
1da177e4 | 82 | #else |
eb8f6890 | 83 | #define __exitused __used |
1da177e4 LT |
84 | #endif |
85 | ||
f0201738 | 86 | #define __exit __section(.exit.text) __exitused __cold notrace |
eb8f6890 | 87 | |
eb8f6890 | 88 | /* Used for MEMORY_HOTPLUG */ |
f0201738 | 89 | #define __meminit __section(.meminit.text) __cold notrace |
eb8f6890 | 90 | #define __meminitdata __section(.meminit.data) |
754b7b63 | 91 | #define __meminitconst __constsection(.meminit.rodata) |
f0201738 | 92 | #define __memexit __section(.memexit.text) __exitused __cold notrace |
eb8f6890 | 93 | #define __memexitdata __section(.memexit.data) |
754b7b63 | 94 | #define __memexitconst __constsection(.memexit.rodata) |
eb8f6890 | 95 | |
1da177e4 | 96 | /* For assembly routines */ |
7923f90f | 97 | #define __HEAD .section ".head.text","ax" |
1da177e4 | 98 | #define __INIT .section ".init.text","ax" |
86c0baf1 | 99 | #define __FINIT .previous |
eb8f6890 | 100 | |
8b5a10fc JB |
101 | #define __INITDATA .section ".init.data","aw",%progbits |
102 | #define __INITRODATA .section ".init.rodata","a",%progbits | |
9f9975a5 | 103 | #define __FINITDATA .previous |
1da177e4 | 104 | |
eb8f6890 SR |
105 | #define __MEMINIT .section ".meminit.text", "ax" |
106 | #define __MEMINITDATA .section ".meminit.data", "aw" | |
3f5e26ce | 107 | #define __MEMINITRODATA .section ".meminit.rodata", "a" |
eb8f6890 | 108 | |
312b1485 SR |
109 | /* silence warnings when references are OK */ |
110 | #define __REF .section ".ref.text", "ax" | |
111 | #define __REFDATA .section ".ref.data", "aw" | |
3f5e26ce | 112 | #define __REFCONST .section ".ref.rodata", "a" |
312b1485 | 113 | |
1da177e4 LT |
114 | #ifndef __ASSEMBLY__ |
115 | /* | |
116 | * Used for initialization calls.. | |
117 | */ | |
118 | typedef int (*initcall_t)(void); | |
119 | typedef void (*exitcall_t)(void); | |
120 | ||
121 | extern initcall_t __con_initcall_start[], __con_initcall_end[]; | |
122 | extern initcall_t __security_initcall_start[], __security_initcall_end[]; | |
123 | ||
b99b87f7 PO |
124 | /* Used for contructor calls. */ |
125 | typedef void (*ctor_fn_t)(void); | |
126 | ||
1da177e4 | 127 | /* Defined in init/main.c */ |
59f9415f | 128 | extern int do_one_initcall(initcall_t fn); |
30d7e0d4 ABL |
129 | extern char __initdata boot_command_line[]; |
130 | extern char *saved_command_line; | |
7e96287d | 131 | extern unsigned int reset_devices; |
77d47582 AB |
132 | |
133 | /* used by init/main.c */ | |
46595390 AB |
134 | void setup_arch(char **); |
135 | void prepare_namespace(void); | |
bb813f4c | 136 | void __init load_default_modules(void); |
57f150a5 | 137 | int __init init_rootfs(void); |
77d47582 | 138 | |
e267d97b KC |
139 | #ifdef CONFIG_DEBUG_RODATA |
140 | void mark_rodata_ro(void); | |
141 | #endif | |
142 | ||
7d195a54 AB |
143 | extern void (*late_time_init)(void); |
144 | ||
2329abfa | 145 | extern bool initcall_debug; |
f2511774 | 146 | |
1da177e4 LT |
147 | #endif |
148 | ||
149 | #ifndef MODULE | |
150 | ||
151 | #ifndef __ASSEMBLY__ | |
152 | ||
ef1b893c AK |
153 | #ifdef CONFIG_LTO |
154 | /* Work around a LTO gcc problem: when there is no reference to a variable | |
155 | * in a module it will be moved to the end of the program. This causes | |
156 | * reordering of initcalls which the kernel does not like. | |
157 | * Add a dummy reference function to avoid this. The function is | |
158 | * deleted by the linker. | |
159 | */ | |
160 | #define LTO_REFERENCE_INITCALL(x) \ | |
161 | ; /* yes this is needed */ \ | |
162 | static __used __exit void *reference_##x(void) \ | |
163 | { \ | |
164 | return &x; \ | |
165 | } | |
166 | #else | |
167 | #define LTO_REFERENCE_INITCALL(x) | |
168 | #endif | |
169 | ||
1da177e4 LT |
170 | /* initcalls are now grouped by functionality into separate |
171 | * subsections. Ordering inside the subsections is determined | |
172 | * by link order. | |
173 | * For backwards compatibility, initcall() puts the call in | |
174 | * the device init subsection. | |
735a7ffb AM |
175 | * |
176 | * The `id' arg to __define_initcall() is needed so that multiple initcalls | |
177 | * can point at the same handler without causing duplicate-symbol build errors. | |
1da177e4 LT |
178 | */ |
179 | ||
7929d407 | 180 | #define __define_initcall(fn, id) \ |
3ff6eecc | 181 | static initcall_t __initcall_##fn##id __used \ |
ef1b893c AK |
182 | __attribute__((__section__(".initcall" #id ".init"))) = fn; \ |
183 | LTO_REFERENCE_INITCALL(__initcall_##fn##id) | |
1da177e4 | 184 | |
c2147a50 EGM |
185 | /* |
186 | * Early initcalls run before initializing SMP. | |
187 | * | |
188 | * Only for built-in code, not modules. | |
189 | */ | |
7929d407 | 190 | #define early_initcall(fn) __define_initcall(fn, early) |
c2147a50 | 191 | |
b3438f82 LT |
192 | /* |
193 | * A "pure" initcall has no dependencies on anything else, and purely | |
194 | * initializes variables that couldn't be statically initialized. | |
195 | * | |
196 | * This only exists for built-in code, not for modules. | |
96263d28 | 197 | * Keep main.c:initcall_level_names[] in sync. |
b3438f82 | 198 | */ |
7929d407 ML |
199 | #define pure_initcall(fn) __define_initcall(fn, 0) |
200 | ||
201 | #define core_initcall(fn) __define_initcall(fn, 1) | |
202 | #define core_initcall_sync(fn) __define_initcall(fn, 1s) | |
203 | #define postcore_initcall(fn) __define_initcall(fn, 2) | |
204 | #define postcore_initcall_sync(fn) __define_initcall(fn, 2s) | |
205 | #define arch_initcall(fn) __define_initcall(fn, 3) | |
206 | #define arch_initcall_sync(fn) __define_initcall(fn, 3s) | |
207 | #define subsys_initcall(fn) __define_initcall(fn, 4) | |
208 | #define subsys_initcall_sync(fn) __define_initcall(fn, 4s) | |
209 | #define fs_initcall(fn) __define_initcall(fn, 5) | |
210 | #define fs_initcall_sync(fn) __define_initcall(fn, 5s) | |
211 | #define rootfs_initcall(fn) __define_initcall(fn, rootfs) | |
212 | #define device_initcall(fn) __define_initcall(fn, 6) | |
213 | #define device_initcall_sync(fn) __define_initcall(fn, 6s) | |
214 | #define late_initcall(fn) __define_initcall(fn, 7) | |
215 | #define late_initcall_sync(fn) __define_initcall(fn, 7s) | |
1da177e4 LT |
216 | |
217 | #define __initcall(fn) device_initcall(fn) | |
218 | ||
219 | #define __exitcall(fn) \ | |
220 | static exitcall_t __exitcall_##fn __exit_call = fn | |
221 | ||
222 | #define console_initcall(fn) \ | |
223 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 224 | __used __section(.con_initcall.init) = fn |
1da177e4 LT |
225 | |
226 | #define security_initcall(fn) \ | |
227 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 228 | __used __section(.security_initcall.init) = fn |
1da177e4 LT |
229 | |
230 | struct obs_kernel_param { | |
231 | const char *str; | |
232 | int (*setup_func)(char *); | |
233 | int early; | |
234 | }; | |
235 | ||
236 | /* | |
237 | * Only for really core code. See moduleparam.h for the normal way. | |
238 | * | |
239 | * Force the alignment so the compiler doesn't space elements of the | |
240 | * obs_kernel_param "array" too far apart in .init.setup. | |
241 | */ | |
242 | #define __setup_param(str, unique_id, fn, early) \ | |
c281b945 IM |
243 | static const char __setup_str_##unique_id[] __initconst \ |
244 | __aligned(1) = str; \ | |
245 | static struct obs_kernel_param __setup_##unique_id \ | |
246 | __used __section(.init.setup) \ | |
247 | __attribute__((aligned((sizeof(long))))) \ | |
1da177e4 LT |
248 | = { __setup_str_##unique_id, fn, early } |
249 | ||
c281b945 | 250 | #define __setup(str, fn) \ |
1da177e4 LT |
251 | __setup_param(str, fn, fn, 0) |
252 | ||
c281b945 IM |
253 | /* |
254 | * NOTE: fn is as per module_param, not __setup! | |
255 | * Emits warning if fn returns non-zero. | |
256 | */ | |
257 | #define early_param(str, fn) \ | |
1da177e4 LT |
258 | __setup_param(str, fn, fn, 1) |
259 | ||
c281b945 IM |
260 | #define early_param_on_off(str_on, str_off, var, config) \ |
261 | \ | |
262 | int var = IS_ENABLED(config); \ | |
263 | \ | |
264 | static int __init parse_##var##_on(char *arg) \ | |
265 | { \ | |
266 | var = 1; \ | |
267 | return 0; \ | |
268 | } \ | |
269 | __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \ | |
270 | \ | |
271 | static int __init parse_##var##_off(char *arg) \ | |
272 | { \ | |
273 | var = 0; \ | |
274 | return 0; \ | |
275 | } \ | |
bfb33bad LR |
276 | __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1) |
277 | ||
30d7e0d4 | 278 | /* Relies on boot_command_line being set */ |
1da177e4 | 279 | void __init parse_early_param(void); |
13977091 | 280 | void __init parse_early_options(char *cmdline); |
1da177e4 LT |
281 | #endif /* __ASSEMBLY__ */ |
282 | ||
1da177e4 LT |
283 | #else /* MODULE */ |
284 | ||
1da177e4 | 285 | #define __setup_param(str, unique_id, fn) /* nothing */ |
1da177e4 | 286 | #define __setup(str, func) /* nothing */ |
1da177e4 LT |
287 | #endif |
288 | ||
ab3bfca7 | 289 | /* Data marked not to be saved by software suspend */ |
07b3bb1e | 290 | #define __nosavedata __section(.data..nosave) |
1da177e4 | 291 | |
1da177e4 LT |
292 | #ifdef MODULE |
293 | #define __exit_p(x) x | |
294 | #else | |
295 | #define __exit_p(x) NULL | |
296 | #endif | |
297 | ||
298 | #endif /* _LINUX_INIT_H */ |