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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 LT |
7 | |
8 | /* These macros are used to mark some functions or | |
9 | * initialized data (doesn't apply to uninitialized data) | |
10 | * as `initialization' functions. The kernel can take this | |
11 | * as hint that the function is used only during the initialization | |
12 | * phase and free up used memory resources after | |
13 | * | |
14 | * Usage: | |
15 | * For functions: | |
16 | * | |
17 | * You should add __init immediately before the function name, like: | |
18 | * | |
19 | * static void __init initme(int x, int y) | |
20 | * { | |
21 | * extern int z; z = x * y; | |
22 | * } | |
23 | * | |
24 | * If the function has a prototype somewhere, you can also add | |
25 | * __init between closing brace of the prototype and semicolon: | |
26 | * | |
27 | * extern int initialize_foobar_device(int, int, int) __init; | |
28 | * | |
29 | * For initialized data: | |
65321547 GU |
30 | * You should insert __initdata or __initconst between the variable name |
31 | * and equal sign followed by value, e.g.: | |
1da177e4 LT |
32 | * |
33 | * static int init_variable __initdata = 0; | |
ae52bb23 | 34 | * static const char linux_logo[] __initconst = { 0x32, 0x36, ... }; |
1da177e4 LT |
35 | * |
36 | * Don't forget to initialize data not at file scope, i.e. within a function, | |
37 | * as gcc otherwise puts the data into the bss section and not into the init | |
38 | * section. | |
1da177e4 LT |
39 | */ |
40 | ||
41 | /* These are for everybody (although not all archs will actually | |
42 | discard it in modules) */ | |
42c269c8 | 43 | #define __init __section(.init.text) __cold __inittrace __latent_entropy |
f3fe866d | 44 | #define __initdata __section(.init.data) |
b5d5cf2b | 45 | #define __initconst __section(.init.rodata) |
f3fe866d | 46 | #define __exitdata __section(.exit.data) |
3ff6eecc | 47 | #define __exit_call __used __section(.exitcall.exit) |
1da177e4 | 48 | |
5ea08178 MN |
49 | /* |
50 | * modpost check for section mismatches during the kernel build. | |
0e0d314e SR |
51 | * A section mismatch happens when there are references from a |
52 | * code or data section to an init section (both code or data). | |
53 | * The init sections are (for most archs) discarded by the kernel | |
54 | * when early init has completed so all such references are potential bugs. | |
55 | * For exit sections the same issue exists. | |
5ea08178 | 56 | * |
0e0d314e | 57 | * The following markers are used for the cases where the reference to |
312b1485 | 58 | * the *init / *exit section (code or data) is valid and will teach |
5ea08178 MN |
59 | * modpost not to issue a warning. Intended semantics is that a code or |
60 | * data tagged __ref* can reference code or data from init section without | |
61 | * producing a warning (of course, no warning does not mean code is | |
62 | * correct, so optimally document why the __ref is needed and why it's OK). | |
63 | * | |
64 | * The markers follow same syntax rules as __init / __initdata. | |
65 | */ | |
312b1485 SR |
66 | #define __ref __section(.ref.text) noinline |
67 | #define __refdata __section(.ref.data) | |
b5d5cf2b | 68 | #define __refconst __section(.ref.rodata) |
312b1485 | 69 | |
1da177e4 | 70 | #ifdef MODULE |
eb8f6890 | 71 | #define __exitused |
42c269c8 | 72 | #define __inittrace notrace |
1da177e4 | 73 | #else |
eb8f6890 | 74 | #define __exitused __used |
42c269c8 | 75 | #define __inittrace |
1da177e4 LT |
76 | #endif |
77 | ||
f0201738 | 78 | #define __exit __section(.exit.text) __exitused __cold notrace |
eb8f6890 | 79 | |
eb8f6890 | 80 | /* Used for MEMORY_HOTPLUG */ |
0766f788 ER |
81 | #define __meminit __section(.meminit.text) __cold notrace \ |
82 | __latent_entropy | |
eb8f6890 | 83 | #define __meminitdata __section(.meminit.data) |
b5d5cf2b | 84 | #define __meminitconst __section(.meminit.rodata) |
f0201738 | 85 | #define __memexit __section(.memexit.text) __exitused __cold notrace |
eb8f6890 | 86 | #define __memexitdata __section(.memexit.data) |
b5d5cf2b | 87 | #define __memexitconst __section(.memexit.rodata) |
eb8f6890 | 88 | |
1da177e4 | 89 | /* For assembly routines */ |
7923f90f | 90 | #define __HEAD .section ".head.text","ax" |
1da177e4 | 91 | #define __INIT .section ".init.text","ax" |
86c0baf1 | 92 | #define __FINIT .previous |
eb8f6890 | 93 | |
8b5a10fc JB |
94 | #define __INITDATA .section ".init.data","aw",%progbits |
95 | #define __INITRODATA .section ".init.rodata","a",%progbits | |
9f9975a5 | 96 | #define __FINITDATA .previous |
1da177e4 | 97 | |
eb8f6890 SR |
98 | #define __MEMINIT .section ".meminit.text", "ax" |
99 | #define __MEMINITDATA .section ".meminit.data", "aw" | |
3f5e26ce | 100 | #define __MEMINITRODATA .section ".meminit.rodata", "a" |
eb8f6890 | 101 | |
312b1485 SR |
102 | /* silence warnings when references are OK */ |
103 | #define __REF .section ".ref.text", "ax" | |
104 | #define __REFDATA .section ".ref.data", "aw" | |
3f5e26ce | 105 | #define __REFCONST .section ".ref.rodata", "a" |
312b1485 | 106 | |
1da177e4 LT |
107 | #ifndef __ASSEMBLY__ |
108 | /* | |
109 | * Used for initialization calls.. | |
110 | */ | |
111 | typedef int (*initcall_t)(void); | |
112 | typedef void (*exitcall_t)(void); | |
113 | ||
114 | extern initcall_t __con_initcall_start[], __con_initcall_end[]; | |
115 | extern initcall_t __security_initcall_start[], __security_initcall_end[]; | |
116 | ||
b99b87f7 PO |
117 | /* Used for contructor calls. */ |
118 | typedef void (*ctor_fn_t)(void); | |
119 | ||
1da177e4 | 120 | /* Defined in init/main.c */ |
59f9415f | 121 | extern int do_one_initcall(initcall_t fn); |
30d7e0d4 ABL |
122 | extern char __initdata boot_command_line[]; |
123 | extern char *saved_command_line; | |
7e96287d | 124 | extern unsigned int reset_devices; |
77d47582 AB |
125 | |
126 | /* used by init/main.c */ | |
46595390 AB |
127 | void setup_arch(char **); |
128 | void prepare_namespace(void); | |
bb813f4c | 129 | void __init load_default_modules(void); |
57f150a5 | 130 | int __init init_rootfs(void); |
77d47582 | 131 | |
0f5bf6d0 | 132 | #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) |
39290b38 AT |
133 | extern bool rodata_enabled; |
134 | #endif | |
0f5bf6d0 | 135 | #ifdef CONFIG_STRICT_KERNEL_RWX |
e267d97b KC |
136 | void mark_rodata_ro(void); |
137 | #endif | |
138 | ||
7d195a54 AB |
139 | extern void (*late_time_init)(void); |
140 | ||
2329abfa | 141 | extern bool initcall_debug; |
f2511774 | 142 | |
1da177e4 LT |
143 | #endif |
144 | ||
145 | #ifndef MODULE | |
146 | ||
147 | #ifndef __ASSEMBLY__ | |
148 | ||
b67067f1 NP |
149 | /* |
150 | * initcalls are now grouped by functionality into separate | |
1da177e4 LT |
151 | * subsections. Ordering inside the subsections is determined |
152 | * by link order. | |
153 | * For backwards compatibility, initcall() puts the call in | |
154 | * the device init subsection. | |
735a7ffb AM |
155 | * |
156 | * The `id' arg to __define_initcall() is needed so that multiple initcalls | |
157 | * can point at the same handler without causing duplicate-symbol build errors. | |
b67067f1 NP |
158 | * |
159 | * Initcalls are run by placing pointers in initcall sections that the | |
160 | * kernel iterates at runtime. The linker can do dead code / data elimination | |
161 | * and remove that completely, so the initcall sections have to be marked | |
162 | * as KEEP() in the linker script. | |
1da177e4 LT |
163 | */ |
164 | ||
7929d407 | 165 | #define __define_initcall(fn, id) \ |
3ff6eecc | 166 | static initcall_t __initcall_##fn##id __used \ |
b67067f1 | 167 | __attribute__((__section__(".initcall" #id ".init"))) = fn; |
1da177e4 | 168 | |
c2147a50 EGM |
169 | /* |
170 | * Early initcalls run before initializing SMP. | |
171 | * | |
172 | * Only for built-in code, not modules. | |
173 | */ | |
7929d407 | 174 | #define early_initcall(fn) __define_initcall(fn, early) |
c2147a50 | 175 | |
b3438f82 LT |
176 | /* |
177 | * A "pure" initcall has no dependencies on anything else, and purely | |
178 | * initializes variables that couldn't be statically initialized. | |
179 | * | |
180 | * This only exists for built-in code, not for modules. | |
96263d28 | 181 | * Keep main.c:initcall_level_names[] in sync. |
b3438f82 | 182 | */ |
7929d407 ML |
183 | #define pure_initcall(fn) __define_initcall(fn, 0) |
184 | ||
185 | #define core_initcall(fn) __define_initcall(fn, 1) | |
186 | #define core_initcall_sync(fn) __define_initcall(fn, 1s) | |
187 | #define postcore_initcall(fn) __define_initcall(fn, 2) | |
188 | #define postcore_initcall_sync(fn) __define_initcall(fn, 2s) | |
189 | #define arch_initcall(fn) __define_initcall(fn, 3) | |
190 | #define arch_initcall_sync(fn) __define_initcall(fn, 3s) | |
191 | #define subsys_initcall(fn) __define_initcall(fn, 4) | |
192 | #define subsys_initcall_sync(fn) __define_initcall(fn, 4s) | |
193 | #define fs_initcall(fn) __define_initcall(fn, 5) | |
194 | #define fs_initcall_sync(fn) __define_initcall(fn, 5s) | |
195 | #define rootfs_initcall(fn) __define_initcall(fn, rootfs) | |
196 | #define device_initcall(fn) __define_initcall(fn, 6) | |
197 | #define device_initcall_sync(fn) __define_initcall(fn, 6s) | |
198 | #define late_initcall(fn) __define_initcall(fn, 7) | |
199 | #define late_initcall_sync(fn) __define_initcall(fn, 7s) | |
1da177e4 LT |
200 | |
201 | #define __initcall(fn) device_initcall(fn) | |
202 | ||
b67067f1 | 203 | #define __exitcall(fn) \ |
1da177e4 LT |
204 | static exitcall_t __exitcall_##fn __exit_call = fn |
205 | ||
b67067f1 NP |
206 | #define console_initcall(fn) \ |
207 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 208 | __used __section(.con_initcall.init) = fn |
1da177e4 | 209 | |
b67067f1 NP |
210 | #define security_initcall(fn) \ |
211 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 212 | __used __section(.security_initcall.init) = fn |
1da177e4 LT |
213 | |
214 | struct obs_kernel_param { | |
215 | const char *str; | |
216 | int (*setup_func)(char *); | |
217 | int early; | |
218 | }; | |
219 | ||
220 | /* | |
221 | * Only for really core code. See moduleparam.h for the normal way. | |
222 | * | |
223 | * Force the alignment so the compiler doesn't space elements of the | |
224 | * obs_kernel_param "array" too far apart in .init.setup. | |
225 | */ | |
226 | #define __setup_param(str, unique_id, fn, early) \ | |
c281b945 IM |
227 | static const char __setup_str_##unique_id[] __initconst \ |
228 | __aligned(1) = str; \ | |
229 | static struct obs_kernel_param __setup_##unique_id \ | |
230 | __used __section(.init.setup) \ | |
231 | __attribute__((aligned((sizeof(long))))) \ | |
1da177e4 LT |
232 | = { __setup_str_##unique_id, fn, early } |
233 | ||
c281b945 | 234 | #define __setup(str, fn) \ |
1da177e4 LT |
235 | __setup_param(str, fn, fn, 0) |
236 | ||
c281b945 IM |
237 | /* |
238 | * NOTE: fn is as per module_param, not __setup! | |
239 | * Emits warning if fn returns non-zero. | |
240 | */ | |
241 | #define early_param(str, fn) \ | |
1da177e4 LT |
242 | __setup_param(str, fn, fn, 1) |
243 | ||
c281b945 IM |
244 | #define early_param_on_off(str_on, str_off, var, config) \ |
245 | \ | |
246 | int var = IS_ENABLED(config); \ | |
247 | \ | |
248 | static int __init parse_##var##_on(char *arg) \ | |
249 | { \ | |
250 | var = 1; \ | |
251 | return 0; \ | |
252 | } \ | |
253 | __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \ | |
254 | \ | |
255 | static int __init parse_##var##_off(char *arg) \ | |
256 | { \ | |
257 | var = 0; \ | |
258 | return 0; \ | |
259 | } \ | |
bfb33bad LR |
260 | __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1) |
261 | ||
30d7e0d4 | 262 | /* Relies on boot_command_line being set */ |
1da177e4 | 263 | void __init parse_early_param(void); |
13977091 | 264 | void __init parse_early_options(char *cmdline); |
1da177e4 LT |
265 | #endif /* __ASSEMBLY__ */ |
266 | ||
1da177e4 LT |
267 | #else /* MODULE */ |
268 | ||
1da177e4 | 269 | #define __setup_param(str, unique_id, fn) /* nothing */ |
1da177e4 | 270 | #define __setup(str, func) /* nothing */ |
1da177e4 LT |
271 | #endif |
272 | ||
ab3bfca7 | 273 | /* Data marked not to be saved by software suspend */ |
07b3bb1e | 274 | #define __nosavedata __section(.data..nosave) |
1da177e4 | 275 | |
1da177e4 LT |
276 | #ifdef MODULE |
277 | #define __exit_p(x) x | |
278 | #else | |
279 | #define __exit_p(x) NULL | |
280 | #endif | |
281 | ||
282 | #endif /* _LINUX_INIT_H */ |