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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_INIT_H |
3 | #define _LINUX_INIT_H | |
4 | ||
1da177e4 | 5 | #include <linux/compiler.h> |
2329abfa | 6 | #include <linux/types.h> |
1da177e4 | 7 | |
66f79309 | 8 | /* Built-in __init functions needn't be compiled with retpoline */ |
87358710 DW |
9 | #if defined(__noretpoline) && !defined(MODULE) |
10 | #define __noinitretpoline __noretpoline | |
66f79309 | 11 | #else |
87358710 | 12 | #define __noinitretpoline |
66f79309 DW |
13 | #endif |
14 | ||
1da177e4 LT |
15 | /* These macros are used to mark some functions or |
16 | * initialized data (doesn't apply to uninitialized data) | |
17 | * as `initialization' functions. The kernel can take this | |
18 | * as hint that the function is used only during the initialization | |
19 | * phase and free up used memory resources after | |
20 | * | |
21 | * Usage: | |
22 | * For functions: | |
23 | * | |
24 | * You should add __init immediately before the function name, like: | |
25 | * | |
26 | * static void __init initme(int x, int y) | |
27 | * { | |
28 | * extern int z; z = x * y; | |
29 | * } | |
30 | * | |
31 | * If the function has a prototype somewhere, you can also add | |
32 | * __init between closing brace of the prototype and semicolon: | |
33 | * | |
34 | * extern int initialize_foobar_device(int, int, int) __init; | |
35 | * | |
36 | * For initialized data: | |
65321547 GU |
37 | * You should insert __initdata or __initconst between the variable name |
38 | * and equal sign followed by value, e.g.: | |
1da177e4 LT |
39 | * |
40 | * static int init_variable __initdata = 0; | |
ae52bb23 | 41 | * static const char linux_logo[] __initconst = { 0x32, 0x36, ... }; |
1da177e4 LT |
42 | * |
43 | * Don't forget to initialize data not at file scope, i.e. within a function, | |
44 | * as gcc otherwise puts the data into the bss section and not into the init | |
45 | * section. | |
1da177e4 LT |
46 | */ |
47 | ||
48 | /* These are for everybody (although not all archs will actually | |
49 | discard it in modules) */ | |
cf68fffb | 50 | #define __init __section(".init.text") __cold __latent_entropy __noinitretpoline __nocfi |
33def849 JP |
51 | #define __initdata __section(".init.data") |
52 | #define __initconst __section(".init.rodata") | |
53 | #define __exitdata __section(".exit.data") | |
54 | #define __exit_call __used __section(".exitcall.exit") | |
1da177e4 | 55 | |
5ea08178 MN |
56 | /* |
57 | * modpost check for section mismatches during the kernel build. | |
0e0d314e SR |
58 | * A section mismatch happens when there are references from a |
59 | * code or data section to an init section (both code or data). | |
60 | * The init sections are (for most archs) discarded by the kernel | |
61 | * when early init has completed so all such references are potential bugs. | |
62 | * For exit sections the same issue exists. | |
5ea08178 | 63 | * |
0e0d314e | 64 | * The following markers are used for the cases where the reference to |
312b1485 | 65 | * the *init / *exit section (code or data) is valid and will teach |
5ea08178 MN |
66 | * modpost not to issue a warning. Intended semantics is that a code or |
67 | * data tagged __ref* can reference code or data from init section without | |
68 | * producing a warning (of course, no warning does not mean code is | |
69 | * correct, so optimally document why the __ref is needed and why it's OK). | |
70 | * | |
71 | * The markers follow same syntax rules as __init / __initdata. | |
72 | */ | |
33def849 JP |
73 | #define __ref __section(".ref.text") noinline |
74 | #define __refdata __section(".ref.data") | |
75 | #define __refconst __section(".ref.rodata") | |
312b1485 | 76 | |
1da177e4 | 77 | #ifdef MODULE |
eb8f6890 | 78 | #define __exitused |
1da177e4 | 79 | #else |
eb8f6890 | 80 | #define __exitused __used |
1da177e4 LT |
81 | #endif |
82 | ||
33def849 | 83 | #define __exit __section(".exit.text") __exitused __cold notrace |
eb8f6890 | 84 | |
eb8f6890 | 85 | /* Used for MEMORY_HOTPLUG */ |
33def849 | 86 | #define __meminit __section(".meminit.text") __cold notrace \ |
0766f788 | 87 | __latent_entropy |
33def849 JP |
88 | #define __meminitdata __section(".meminit.data") |
89 | #define __meminitconst __section(".meminit.rodata") | |
90 | #define __memexit __section(".memexit.text") __exitused __cold notrace | |
91 | #define __memexitdata __section(".memexit.data") | |
92 | #define __memexitconst __section(".memexit.rodata") | |
eb8f6890 | 93 | |
1da177e4 | 94 | /* For assembly routines */ |
7923f90f | 95 | #define __HEAD .section ".head.text","ax" |
1da177e4 | 96 | #define __INIT .section ".init.text","ax" |
86c0baf1 | 97 | #define __FINIT .previous |
eb8f6890 | 98 | |
8b5a10fc JB |
99 | #define __INITDATA .section ".init.data","aw",%progbits |
100 | #define __INITRODATA .section ".init.rodata","a",%progbits | |
9f9975a5 | 101 | #define __FINITDATA .previous |
1da177e4 | 102 | |
eb8f6890 SR |
103 | #define __MEMINIT .section ".meminit.text", "ax" |
104 | #define __MEMINITDATA .section ".meminit.data", "aw" | |
3f5e26ce | 105 | #define __MEMINITRODATA .section ".meminit.rodata", "a" |
eb8f6890 | 106 | |
312b1485 SR |
107 | /* silence warnings when references are OK */ |
108 | #define __REF .section ".ref.text", "ax" | |
109 | #define __REFDATA .section ".ref.data", "aw" | |
3f5e26ce | 110 | #define __REFCONST .section ".ref.rodata", "a" |
312b1485 | 111 | |
1da177e4 LT |
112 | #ifndef __ASSEMBLY__ |
113 | /* | |
114 | * Used for initialization calls.. | |
115 | */ | |
116 | typedef int (*initcall_t)(void); | |
117 | typedef void (*exitcall_t)(void); | |
118 | ||
1b1eeca7 AB |
119 | #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
120 | typedef int initcall_entry_t; | |
121 | ||
122 | static inline initcall_t initcall_from_entry(initcall_entry_t *entry) | |
123 | { | |
124 | return offset_to_ptr(entry); | |
125 | } | |
126 | #else | |
127 | typedef initcall_t initcall_entry_t; | |
128 | ||
129 | static inline initcall_t initcall_from_entry(initcall_entry_t *entry) | |
130 | { | |
131 | return *entry; | |
132 | } | |
133 | #endif | |
134 | ||
135 | extern initcall_entry_t __con_initcall_start[], __con_initcall_end[]; | |
1da177e4 | 136 | |
b99b87f7 PO |
137 | /* Used for contructor calls. */ |
138 | typedef void (*ctor_fn_t)(void); | |
139 | ||
fd3e007f AV |
140 | struct file_system_type; |
141 | ||
1da177e4 | 142 | /* Defined in init/main.c */ |
59f9415f | 143 | extern int do_one_initcall(initcall_t fn); |
30d7e0d4 ABL |
144 | extern char __initdata boot_command_line[]; |
145 | extern char *saved_command_line; | |
7e96287d | 146 | extern unsigned int reset_devices; |
77d47582 AB |
147 | |
148 | /* used by init/main.c */ | |
46595390 AB |
149 | void setup_arch(char **); |
150 | void prepare_namespace(void); | |
037f11b4 | 151 | void __init init_rootfs(void); |
fd3e007f | 152 | extern struct file_system_type rootfs_fs_type; |
77d47582 | 153 | |
0f5bf6d0 | 154 | #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) |
39290b38 AT |
155 | extern bool rodata_enabled; |
156 | #endif | |
0f5bf6d0 | 157 | #ifdef CONFIG_STRICT_KERNEL_RWX |
e267d97b KC |
158 | void mark_rodata_ro(void); |
159 | #endif | |
160 | ||
7d195a54 AB |
161 | extern void (*late_time_init)(void); |
162 | ||
2329abfa | 163 | extern bool initcall_debug; |
f2511774 | 164 | |
1da177e4 LT |
165 | #endif |
166 | ||
167 | #ifndef MODULE | |
168 | ||
169 | #ifndef __ASSEMBLY__ | |
170 | ||
b67067f1 NP |
171 | /* |
172 | * initcalls are now grouped by functionality into separate | |
1da177e4 LT |
173 | * subsections. Ordering inside the subsections is determined |
174 | * by link order. | |
175 | * For backwards compatibility, initcall() puts the call in | |
176 | * the device init subsection. | |
735a7ffb AM |
177 | * |
178 | * The `id' arg to __define_initcall() is needed so that multiple initcalls | |
179 | * can point at the same handler without causing duplicate-symbol build errors. | |
b67067f1 NP |
180 | * |
181 | * Initcalls are run by placing pointers in initcall sections that the | |
182 | * kernel iterates at runtime. The linker can do dead code / data elimination | |
183 | * and remove that completely, so the initcall sections have to be marked | |
184 | * as KEEP() in the linker script. | |
1da177e4 LT |
185 | */ |
186 | ||
a8cccdd9 ST |
187 | /* Format: <modname>__<counter>_<line>_<fn> */ |
188 | #define __initcall_id(fn) \ | |
189 | __PASTE(__KBUILD_MODNAME, \ | |
190 | __PASTE(__, \ | |
191 | __PASTE(__COUNTER__, \ | |
192 | __PASTE(_, \ | |
193 | __PASTE(__LINE__, \ | |
194 | __PASTE(_, fn)))))) | |
195 | ||
196 | /* Format: __<prefix>__<iid><id> */ | |
197 | #define __initcall_name(prefix, __iid, id) \ | |
198 | __PASTE(__, \ | |
199 | __PASTE(prefix, \ | |
200 | __PASTE(__, \ | |
201 | __PASTE(__iid, id)))) | |
202 | ||
203 | #ifdef CONFIG_LTO_CLANG | |
204 | /* | |
205 | * With LTO, the compiler doesn't necessarily obey link order for | |
206 | * initcalls. In order to preserve the correct order, we add each | |
207 | * variable into its own section and generate a linker script (in | |
208 | * scripts/link-vmlinux.sh) to specify the order of the sections. | |
209 | */ | |
210 | #define __initcall_section(__sec, __iid) \ | |
211 | #__sec ".init.." #__iid | |
3578ad11 ST |
212 | |
213 | /* | |
214 | * With LTO, the compiler can rename static functions to avoid | |
215 | * global naming collisions. We use a global stub function for | |
216 | * initcalls to create a stable symbol name whose address can be | |
217 | * taken in inline assembly when PREL32 relocations are used. | |
218 | */ | |
219 | #define __initcall_stub(fn, __iid, id) \ | |
220 | __initcall_name(initstub, __iid, id) | |
221 | ||
222 | #define __define_initcall_stub(__stub, fn) \ | |
ff301ceb ST |
223 | int __init __cficanonical __stub(void); \ |
224 | int __init __cficanonical __stub(void) \ | |
3578ad11 ST |
225 | { \ |
226 | return fn(); \ | |
227 | } \ | |
228 | __ADDRESSABLE(__stub) | |
a8cccdd9 ST |
229 | #else |
230 | #define __initcall_section(__sec, __iid) \ | |
231 | #__sec ".init" | |
3578ad11 ST |
232 | |
233 | #define __initcall_stub(fn, __iid, id) fn | |
234 | ||
235 | #define __define_initcall_stub(__stub, fn) \ | |
236 | __ADDRESSABLE(fn) | |
a8cccdd9 ST |
237 | #endif |
238 | ||
1b1eeca7 | 239 | #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
3578ad11 ST |
240 | #define ____define_initcall(fn, __stub, __name, __sec) \ |
241 | __define_initcall_stub(__stub, fn) \ | |
a8cccdd9 ST |
242 | asm(".section \"" __sec "\", \"a\" \n" \ |
243 | __stringify(__name) ": \n" \ | |
3578ad11 | 244 | ".long " __stringify(__stub) " - . \n" \ |
1cb61759 ME |
245 | ".previous \n"); \ |
246 | static_assert(__same_type(initcall_t, &fn)); | |
1b1eeca7 | 247 | #else |
3578ad11 | 248 | #define ____define_initcall(fn, __unused, __name, __sec) \ |
a8cccdd9 ST |
249 | static initcall_t __name __used \ |
250 | __attribute__((__section__(__sec))) = fn; | |
1b1eeca7 AB |
251 | #endif |
252 | ||
a8cccdd9 ST |
253 | #define __unique_initcall(fn, id, __sec, __iid) \ |
254 | ____define_initcall(fn, \ | |
3578ad11 | 255 | __initcall_stub(fn, __iid, id), \ |
a8cccdd9 ST |
256 | __initcall_name(initcall, __iid, id), \ |
257 | __initcall_section(__sec, __iid)) | |
258 | ||
259 | #define ___define_initcall(fn, id, __sec) \ | |
260 | __unique_initcall(fn, id, __sec, __initcall_id(fn)) | |
261 | ||
1b1eeca7 | 262 | #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id) |
1da177e4 | 263 | |
c2147a50 EGM |
264 | /* |
265 | * Early initcalls run before initializing SMP. | |
266 | * | |
267 | * Only for built-in code, not modules. | |
268 | */ | |
7929d407 | 269 | #define early_initcall(fn) __define_initcall(fn, early) |
c2147a50 | 270 | |
b3438f82 LT |
271 | /* |
272 | * A "pure" initcall has no dependencies on anything else, and purely | |
273 | * initializes variables that couldn't be statically initialized. | |
274 | * | |
275 | * This only exists for built-in code, not for modules. | |
96263d28 | 276 | * Keep main.c:initcall_level_names[] in sync. |
b3438f82 | 277 | */ |
7929d407 ML |
278 | #define pure_initcall(fn) __define_initcall(fn, 0) |
279 | ||
280 | #define core_initcall(fn) __define_initcall(fn, 1) | |
281 | #define core_initcall_sync(fn) __define_initcall(fn, 1s) | |
282 | #define postcore_initcall(fn) __define_initcall(fn, 2) | |
283 | #define postcore_initcall_sync(fn) __define_initcall(fn, 2s) | |
284 | #define arch_initcall(fn) __define_initcall(fn, 3) | |
285 | #define arch_initcall_sync(fn) __define_initcall(fn, 3s) | |
286 | #define subsys_initcall(fn) __define_initcall(fn, 4) | |
287 | #define subsys_initcall_sync(fn) __define_initcall(fn, 4s) | |
288 | #define fs_initcall(fn) __define_initcall(fn, 5) | |
289 | #define fs_initcall_sync(fn) __define_initcall(fn, 5s) | |
290 | #define rootfs_initcall(fn) __define_initcall(fn, rootfs) | |
291 | #define device_initcall(fn) __define_initcall(fn, 6) | |
292 | #define device_initcall_sync(fn) __define_initcall(fn, 6s) | |
293 | #define late_initcall(fn) __define_initcall(fn, 7) | |
294 | #define late_initcall_sync(fn) __define_initcall(fn, 7s) | |
1da177e4 LT |
295 | |
296 | #define __initcall(fn) device_initcall(fn) | |
297 | ||
b67067f1 | 298 | #define __exitcall(fn) \ |
1da177e4 LT |
299 | static exitcall_t __exitcall_##fn __exit_call = fn |
300 | ||
a8cccdd9 | 301 | #define console_initcall(fn) ___define_initcall(fn, con, .con_initcall) |
1da177e4 LT |
302 | |
303 | struct obs_kernel_param { | |
304 | const char *str; | |
305 | int (*setup_func)(char *); | |
306 | int early; | |
307 | }; | |
308 | ||
309 | /* | |
310 | * Only for really core code. See moduleparam.h for the normal way. | |
311 | * | |
312 | * Force the alignment so the compiler doesn't space elements of the | |
313 | * obs_kernel_param "array" too far apart in .init.setup. | |
314 | */ | |
315 | #define __setup_param(str, unique_id, fn, early) \ | |
c281b945 IM |
316 | static const char __setup_str_##unique_id[] __initconst \ |
317 | __aligned(1) = str; \ | |
318 | static struct obs_kernel_param __setup_##unique_id \ | |
33def849 | 319 | __used __section(".init.setup") \ |
147ad605 | 320 | __aligned(__alignof__(struct obs_kernel_param)) \ |
1da177e4 LT |
321 | = { __setup_str_##unique_id, fn, early } |
322 | ||
c281b945 | 323 | #define __setup(str, fn) \ |
1da177e4 LT |
324 | __setup_param(str, fn, fn, 0) |
325 | ||
c281b945 IM |
326 | /* |
327 | * NOTE: fn is as per module_param, not __setup! | |
328 | * Emits warning if fn returns non-zero. | |
329 | */ | |
330 | #define early_param(str, fn) \ | |
1da177e4 LT |
331 | __setup_param(str, fn, fn, 1) |
332 | ||
c281b945 IM |
333 | #define early_param_on_off(str_on, str_off, var, config) \ |
334 | \ | |
335 | int var = IS_ENABLED(config); \ | |
336 | \ | |
337 | static int __init parse_##var##_on(char *arg) \ | |
338 | { \ | |
339 | var = 1; \ | |
340 | return 0; \ | |
341 | } \ | |
a5a673f7 | 342 | early_param(str_on, parse_##var##_on); \ |
c281b945 IM |
343 | \ |
344 | static int __init parse_##var##_off(char *arg) \ | |
345 | { \ | |
346 | var = 0; \ | |
347 | return 0; \ | |
348 | } \ | |
a5a673f7 | 349 | early_param(str_off, parse_##var##_off) |
bfb33bad | 350 | |
30d7e0d4 | 351 | /* Relies on boot_command_line being set */ |
1da177e4 | 352 | void __init parse_early_param(void); |
13977091 | 353 | void __init parse_early_options(char *cmdline); |
1da177e4 LT |
354 | #endif /* __ASSEMBLY__ */ |
355 | ||
1da177e4 LT |
356 | #else /* MODULE */ |
357 | ||
1da177e4 | 358 | #define __setup_param(str, unique_id, fn) /* nothing */ |
1da177e4 | 359 | #define __setup(str, func) /* nothing */ |
1da177e4 LT |
360 | #endif |
361 | ||
ab3bfca7 | 362 | /* Data marked not to be saved by software suspend */ |
33def849 | 363 | #define __nosavedata __section(".data..nosave") |
1da177e4 | 364 | |
1da177e4 LT |
365 | #ifdef MODULE |
366 | #define __exit_p(x) x | |
367 | #else | |
368 | #define __exit_p(x) NULL | |
369 | #endif | |
370 | ||
371 | #endif /* _LINUX_INIT_H */ |