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1da177e4 LT |
1 | #ifndef _LINUX_INIT_H |
2 | #define _LINUX_INIT_H | |
3 | ||
1da177e4 LT |
4 | #include <linux/compiler.h> |
5 | ||
6 | /* These macros are used to mark some functions or | |
7 | * initialized data (doesn't apply to uninitialized data) | |
8 | * as `initialization' functions. The kernel can take this | |
9 | * as hint that the function is used only during the initialization | |
10 | * phase and free up used memory resources after | |
11 | * | |
12 | * Usage: | |
13 | * For functions: | |
14 | * | |
15 | * You should add __init immediately before the function name, like: | |
16 | * | |
17 | * static void __init initme(int x, int y) | |
18 | * { | |
19 | * extern int z; z = x * y; | |
20 | * } | |
21 | * | |
22 | * If the function has a prototype somewhere, you can also add | |
23 | * __init between closing brace of the prototype and semicolon: | |
24 | * | |
25 | * extern int initialize_foobar_device(int, int, int) __init; | |
26 | * | |
27 | * For initialized data: | |
28 | * You should insert __initdata between the variable name and equal | |
29 | * sign followed by value, e.g.: | |
30 | * | |
31 | * static int init_variable __initdata = 0; | |
32 | * static char linux_logo[] __initdata = { 0x32, 0x36, ... }; | |
33 | * | |
34 | * Don't forget to initialize data not at file scope, i.e. within a function, | |
35 | * as gcc otherwise puts the data into the bss section and not into the init | |
36 | * section. | |
37 | * | |
38 | * Also note, that this data cannot be "const". | |
39 | */ | |
40 | ||
41 | /* These are for everybody (although not all archs will actually | |
42 | discard it in modules) */ | |
f3fe866d SR |
43 | #define __init __section(.init.text) __cold |
44 | #define __initdata __section(.init.data) | |
37c514e3 | 45 | #define __initconst __section(.init.rodata) |
f3fe866d | 46 | #define __exitdata __section(.exit.data) |
3ff6eecc | 47 | #define __exit_call __used __section(.exitcall.exit) |
1da177e4 | 48 | |
0e0d314e SR |
49 | /* modpost check for section mismatches during the kernel build. |
50 | * A section mismatch happens when there are references from a | |
51 | * code or data section to an init section (both code or data). | |
52 | * The init sections are (for most archs) discarded by the kernel | |
53 | * when early init has completed so all such references are potential bugs. | |
54 | * For exit sections the same issue exists. | |
55 | * The following markers are used for the cases where the reference to | |
312b1485 SR |
56 | * the *init / *exit section (code or data) is valid and will teach |
57 | * modpost not to issue a warning. | |
0e0d314e | 58 | * The markers follow same syntax rules as __init / __initdata. */ |
312b1485 SR |
59 | #define __ref __section(.ref.text) noinline |
60 | #define __refdata __section(.ref.data) | |
61 | #define __refconst __section(.ref.rodata) | |
62 | ||
63 | /* backward compatibility note | |
64 | * A few places hardcode the old section names: | |
65 | * .text.init.refok | |
66 | * .data.init.refok | |
67 | * .exit.text.refok | |
68 | * They should be converted to use the defines from this file | |
69 | */ | |
70 | ||
71 | /* compatibility defines */ | |
72 | #define __init_refok __ref | |
73 | #define __initdata_refok __refdata | |
74 | #define __exit_refok __ref | |
75 | ||
0e0d314e | 76 | |
1da177e4 | 77 | #ifdef MODULE |
eb8f6890 | 78 | #define __exitused |
1da177e4 | 79 | #else |
eb8f6890 | 80 | #define __exitused __used |
1da177e4 LT |
81 | #endif |
82 | ||
eb8f6890 SR |
83 | #define __exit __section(.exit.text) __exitused __cold |
84 | ||
85 | /* Used for HOTPLUG */ | |
86 | #define __devinit __section(.devinit.text) __cold | |
87 | #define __devinitdata __section(.devinit.data) | |
88 | #define __devinitconst __section(.devinit.rodata) | |
89 | #define __devexit __section(.devexit.text) __exitused __cold | |
90 | #define __devexitdata __section(.devexit.data) | |
91 | #define __devexitconst __section(.devexit.rodata) | |
92 | ||
93 | /* Used for HOTPLUG_CPU */ | |
94 | #define __cpuinit __section(.cpuinit.text) __cold | |
95 | #define __cpuinitdata __section(.cpuinit.data) | |
96 | #define __cpuinitconst __section(.cpuinit.rodata) | |
97 | #define __cpuexit __section(.cpuexit.text) __exitused __cold | |
98 | #define __cpuexitdata __section(.cpuexit.data) | |
99 | #define __cpuexitconst __section(.cpuexit.rodata) | |
100 | ||
101 | /* Used for MEMORY_HOTPLUG */ | |
102 | #define __meminit __section(.meminit.text) __cold | |
103 | #define __meminitdata __section(.meminit.data) | |
104 | #define __meminitconst __section(.meminit.rodata) | |
105 | #define __memexit __section(.memexit.text) __exitused __cold | |
106 | #define __memexitdata __section(.memexit.data) | |
107 | #define __memexitconst __section(.memexit.rodata) | |
108 | ||
1da177e4 | 109 | /* For assembly routines */ |
37c514e3 | 110 | #define __HEAD .section ".head.text","ax" |
1da177e4 | 111 | #define __INIT .section ".init.text","ax" |
86c0baf1 | 112 | #define __FINIT .previous |
eb8f6890 | 113 | |
838c4118 | 114 | #define __INITDATA .section ".init.data","aw" |
9f9975a5 | 115 | #define __FINITDATA .previous |
1da177e4 | 116 | |
eb8f6890 SR |
117 | #define __DEVINIT .section ".devinit.text", "ax" |
118 | #define __DEVINITDATA .section ".devinit.data", "aw" | |
119 | ||
120 | #define __CPUINIT .section ".cpuinit.text", "ax" | |
121 | #define __CPUINITDATA .section ".cpuinit.data", "aw" | |
122 | ||
123 | #define __MEMINIT .section ".meminit.text", "ax" | |
124 | #define __MEMINITDATA .section ".meminit.data", "aw" | |
125 | ||
312b1485 SR |
126 | /* silence warnings when references are OK */ |
127 | #define __REF .section ".ref.text", "ax" | |
128 | #define __REFDATA .section ".ref.data", "aw" | |
129 | #define __REFCONST .section ".ref.rodata", "aw" | |
312b1485 | 130 | |
1da177e4 LT |
131 | #ifndef __ASSEMBLY__ |
132 | /* | |
133 | * Used for initialization calls.. | |
134 | */ | |
135 | typedef int (*initcall_t)(void); | |
136 | typedef void (*exitcall_t)(void); | |
137 | ||
138 | extern initcall_t __con_initcall_start[], __con_initcall_end[]; | |
139 | extern initcall_t __security_initcall_start[], __security_initcall_end[]; | |
140 | ||
141 | /* Defined in init/main.c */ | |
59f9415f | 142 | extern int do_one_initcall(initcall_t fn); |
30d7e0d4 ABL |
143 | extern char __initdata boot_command_line[]; |
144 | extern char *saved_command_line; | |
7e96287d | 145 | extern unsigned int reset_devices; |
77d47582 AB |
146 | |
147 | /* used by init/main.c */ | |
46595390 AB |
148 | void setup_arch(char **); |
149 | void prepare_namespace(void); | |
77d47582 | 150 | |
7d195a54 AB |
151 | extern void (*late_time_init)(void); |
152 | ||
1da177e4 LT |
153 | #endif |
154 | ||
155 | #ifndef MODULE | |
156 | ||
157 | #ifndef __ASSEMBLY__ | |
158 | ||
159 | /* initcalls are now grouped by functionality into separate | |
160 | * subsections. Ordering inside the subsections is determined | |
161 | * by link order. | |
162 | * For backwards compatibility, initcall() puts the call in | |
163 | * the device init subsection. | |
735a7ffb AM |
164 | * |
165 | * The `id' arg to __define_initcall() is needed so that multiple initcalls | |
166 | * can point at the same handler without causing duplicate-symbol build errors. | |
1da177e4 LT |
167 | */ |
168 | ||
735a7ffb | 169 | #define __define_initcall(level,fn,id) \ |
3ff6eecc | 170 | static initcall_t __initcall_##fn##id __used \ |
1da177e4 LT |
171 | __attribute__((__section__(".initcall" level ".init"))) = fn |
172 | ||
c2147a50 EGM |
173 | /* |
174 | * Early initcalls run before initializing SMP. | |
175 | * | |
176 | * Only for built-in code, not modules. | |
177 | */ | |
178 | #define early_initcall(fn) __define_initcall("early",fn,early) | |
179 | ||
b3438f82 LT |
180 | /* |
181 | * A "pure" initcall has no dependencies on anything else, and purely | |
182 | * initializes variables that couldn't be statically initialized. | |
183 | * | |
184 | * This only exists for built-in code, not for modules. | |
185 | */ | |
73dd1166 | 186 | #define pure_initcall(fn) __define_initcall("0",fn,0) |
b3438f82 | 187 | |
735a7ffb AM |
188 | #define core_initcall(fn) __define_initcall("1",fn,1) |
189 | #define core_initcall_sync(fn) __define_initcall("1s",fn,1s) | |
190 | #define postcore_initcall(fn) __define_initcall("2",fn,2) | |
191 | #define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s) | |
192 | #define arch_initcall(fn) __define_initcall("3",fn,3) | |
193 | #define arch_initcall_sync(fn) __define_initcall("3s",fn,3s) | |
194 | #define subsys_initcall(fn) __define_initcall("4",fn,4) | |
195 | #define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s) | |
196 | #define fs_initcall(fn) __define_initcall("5",fn,5) | |
197 | #define fs_initcall_sync(fn) __define_initcall("5s",fn,5s) | |
8d610dd5 | 198 | #define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs) |
735a7ffb AM |
199 | #define device_initcall(fn) __define_initcall("6",fn,6) |
200 | #define device_initcall_sync(fn) __define_initcall("6s",fn,6s) | |
201 | #define late_initcall(fn) __define_initcall("7",fn,7) | |
202 | #define late_initcall_sync(fn) __define_initcall("7s",fn,7s) | |
1da177e4 LT |
203 | |
204 | #define __initcall(fn) device_initcall(fn) | |
205 | ||
206 | #define __exitcall(fn) \ | |
207 | static exitcall_t __exitcall_##fn __exit_call = fn | |
208 | ||
209 | #define console_initcall(fn) \ | |
210 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 211 | __used __section(.con_initcall.init) = fn |
1da177e4 LT |
212 | |
213 | #define security_initcall(fn) \ | |
214 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 215 | __used __section(.security_initcall.init) = fn |
1da177e4 LT |
216 | |
217 | struct obs_kernel_param { | |
218 | const char *str; | |
219 | int (*setup_func)(char *); | |
220 | int early; | |
221 | }; | |
222 | ||
223 | /* | |
224 | * Only for really core code. See moduleparam.h for the normal way. | |
225 | * | |
226 | * Force the alignment so the compiler doesn't space elements of the | |
227 | * obs_kernel_param "array" too far apart in .init.setup. | |
228 | */ | |
229 | #define __setup_param(str, unique_id, fn, early) \ | |
d5aa0daf | 230 | static char __setup_str_##unique_id[] __initdata __aligned(1) = str; \ |
1da177e4 | 231 | static struct obs_kernel_param __setup_##unique_id \ |
3ff6eecc | 232 | __used __section(.init.setup) \ |
1da177e4 LT |
233 | __attribute__((aligned((sizeof(long))))) \ |
234 | = { __setup_str_##unique_id, fn, early } | |
235 | ||
236 | #define __setup_null_param(str, unique_id) \ | |
237 | __setup_param(str, unique_id, NULL, 0) | |
238 | ||
239 | #define __setup(str, fn) \ | |
240 | __setup_param(str, fn, fn, 0) | |
241 | ||
1da177e4 LT |
242 | /* NOTE: fn is as per module_param, not __setup! Emits warning if fn |
243 | * returns non-zero. */ | |
244 | #define early_param(str, fn) \ | |
245 | __setup_param(str, fn, fn, 1) | |
246 | ||
30d7e0d4 | 247 | /* Relies on boot_command_line being set */ |
1da177e4 LT |
248 | void __init parse_early_param(void); |
249 | #endif /* __ASSEMBLY__ */ | |
250 | ||
251 | /** | |
252 | * module_init() - driver initialization entry point | |
253 | * @x: function to be run at kernel boot time or module insertion | |
254 | * | |
72fd4a35 | 255 | * module_init() will either be called during do_initcalls() (if |
1da177e4 LT |
256 | * builtin) or at module insertion time (if a module). There can only |
257 | * be one per module. | |
258 | */ | |
259 | #define module_init(x) __initcall(x); | |
260 | ||
261 | /** | |
262 | * module_exit() - driver exit entry point | |
263 | * @x: function to be run when driver is removed | |
264 | * | |
265 | * module_exit() will wrap the driver clean-up code | |
266 | * with cleanup_module() when used with rmmod when | |
267 | * the driver is a module. If the driver is statically | |
268 | * compiled into the kernel, module_exit() has no effect. | |
269 | * There can only be one per module. | |
270 | */ | |
271 | #define module_exit(x) __exitcall(x); | |
272 | ||
273 | #else /* MODULE */ | |
274 | ||
275 | /* Don't use these in modules, but some people do... */ | |
276 | #define core_initcall(fn) module_init(fn) | |
277 | #define postcore_initcall(fn) module_init(fn) | |
278 | #define arch_initcall(fn) module_init(fn) | |
279 | #define subsys_initcall(fn) module_init(fn) | |
280 | #define fs_initcall(fn) module_init(fn) | |
281 | #define device_initcall(fn) module_init(fn) | |
282 | #define late_initcall(fn) module_init(fn) | |
283 | ||
284 | #define security_initcall(fn) module_init(fn) | |
285 | ||
4500d067 | 286 | /* Each module must use one module_init(). */ |
1da177e4 LT |
287 | #define module_init(initfn) \ |
288 | static inline initcall_t __inittest(void) \ | |
289 | { return initfn; } \ | |
290 | int init_module(void) __attribute__((alias(#initfn))); | |
291 | ||
292 | /* This is only required if you want to be unloadable. */ | |
293 | #define module_exit(exitfn) \ | |
294 | static inline exitcall_t __exittest(void) \ | |
295 | { return exitfn; } \ | |
296 | void cleanup_module(void) __attribute__((alias(#exitfn))); | |
297 | ||
298 | #define __setup_param(str, unique_id, fn) /* nothing */ | |
299 | #define __setup_null_param(str, unique_id) /* nothing */ | |
300 | #define __setup(str, func) /* nothing */ | |
1da177e4 LT |
301 | #endif |
302 | ||
ab3bfca7 | 303 | /* Data marked not to be saved by software suspend */ |
f3fe866d | 304 | #define __nosavedata __section(.data.nosave) |
1da177e4 LT |
305 | |
306 | /* This means "can be init if no module support, otherwise module load | |
307 | may call it." */ | |
308 | #ifdef CONFIG_MODULES | |
309 | #define __init_or_module | |
310 | #define __initdata_or_module | |
311 | #else | |
312 | #define __init_or_module __init | |
313 | #define __initdata_or_module __initdata | |
314 | #endif /*CONFIG_MODULES*/ | |
315 | ||
1da177e4 LT |
316 | /* Functions marked as __devexit may be discarded at kernel link time, depending |
317 | on config options. Newer versions of binutils detect references from | |
318 | retained sections to discarded sections and flag an error. Pointers to | |
319 | __devexit functions must use __devexit_p(function_name), the wrapper will | |
320 | insert either the function_name or NULL, depending on the config options. | |
321 | */ | |
322 | #if defined(MODULE) || defined(CONFIG_HOTPLUG) | |
323 | #define __devexit_p(x) x | |
324 | #else | |
325 | #define __devexit_p(x) NULL | |
326 | #endif | |
327 | ||
328 | #ifdef MODULE | |
329 | #define __exit_p(x) x | |
330 | #else | |
331 | #define __exit_p(x) NULL | |
332 | #endif | |
333 | ||
334 | #endif /* _LINUX_INIT_H */ |