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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 | |
366adff8 | 8 | /* Built-in __init functions needn't be compiled with retpoline */ |
79a1bd31 DW |
9 | #if defined(__noretpoline) && !defined(MODULE) |
10 | #define __noinitretpoline __noretpoline | |
366adff8 | 11 | #else |
79a1bd31 | 12 | #define __noinitretpoline |
366adff8 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) */ | |
79a1bd31 | 50 | #define __init __section(.init.text) __cold __latent_entropy __noinitretpoline |
f3fe866d | 51 | #define __initdata __section(.init.data) |
b5d5cf2b | 52 | #define __initconst __section(.init.rodata) |
f3fe866d | 53 | #define __exitdata __section(.exit.data) |
3ff6eecc | 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 | */ | |
312b1485 SR |
73 | #define __ref __section(.ref.text) noinline |
74 | #define __refdata __section(.ref.data) | |
b5d5cf2b | 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 | ||
f0201738 | 83 | #define __exit __section(.exit.text) __exitused __cold notrace |
eb8f6890 | 84 | |
eb8f6890 | 85 | /* Used for MEMORY_HOTPLUG */ |
0766f788 ER |
86 | #define __meminit __section(.meminit.text) __cold notrace \ |
87 | __latent_entropy | |
eb8f6890 | 88 | #define __meminitdata __section(.meminit.data) |
b5d5cf2b | 89 | #define __meminitconst __section(.meminit.rodata) |
f0201738 | 90 | #define __memexit __section(.memexit.text) __exitused __cold notrace |
eb8f6890 | 91 | #define __memexitdata __section(.memexit.data) |
b5d5cf2b | 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 | ||
119 | extern initcall_t __con_initcall_start[], __con_initcall_end[]; | |
120 | extern initcall_t __security_initcall_start[], __security_initcall_end[]; | |
121 | ||
b99b87f7 PO |
122 | /* Used for contructor calls. */ |
123 | typedef void (*ctor_fn_t)(void); | |
124 | ||
1da177e4 | 125 | /* Defined in init/main.c */ |
59f9415f | 126 | extern int do_one_initcall(initcall_t fn); |
30d7e0d4 ABL |
127 | extern char __initdata boot_command_line[]; |
128 | extern char *saved_command_line; | |
7e96287d | 129 | extern unsigned int reset_devices; |
77d47582 AB |
130 | |
131 | /* used by init/main.c */ | |
46595390 AB |
132 | void setup_arch(char **); |
133 | void prepare_namespace(void); | |
bb813f4c | 134 | void __init load_default_modules(void); |
57f150a5 | 135 | int __init init_rootfs(void); |
77d47582 | 136 | |
0f5bf6d0 | 137 | #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) |
39290b38 AT |
138 | extern bool rodata_enabled; |
139 | #endif | |
0f5bf6d0 | 140 | #ifdef CONFIG_STRICT_KERNEL_RWX |
e267d97b KC |
141 | void mark_rodata_ro(void); |
142 | #endif | |
143 | ||
7d195a54 AB |
144 | extern void (*late_time_init)(void); |
145 | ||
2329abfa | 146 | extern bool initcall_debug; |
f2511774 | 147 | |
1da177e4 LT |
148 | #endif |
149 | ||
150 | #ifndef MODULE | |
151 | ||
152 | #ifndef __ASSEMBLY__ | |
153 | ||
b67067f1 NP |
154 | /* |
155 | * initcalls are now grouped by functionality into separate | |
1da177e4 LT |
156 | * subsections. Ordering inside the subsections is determined |
157 | * by link order. | |
158 | * For backwards compatibility, initcall() puts the call in | |
159 | * the device init subsection. | |
735a7ffb AM |
160 | * |
161 | * The `id' arg to __define_initcall() is needed so that multiple initcalls | |
162 | * can point at the same handler without causing duplicate-symbol build errors. | |
b67067f1 NP |
163 | * |
164 | * Initcalls are run by placing pointers in initcall sections that the | |
165 | * kernel iterates at runtime. The linker can do dead code / data elimination | |
166 | * and remove that completely, so the initcall sections have to be marked | |
167 | * as KEEP() in the linker script. | |
1da177e4 LT |
168 | */ |
169 | ||
7929d407 | 170 | #define __define_initcall(fn, id) \ |
3ff6eecc | 171 | static initcall_t __initcall_##fn##id __used \ |
b67067f1 | 172 | __attribute__((__section__(".initcall" #id ".init"))) = fn; |
1da177e4 | 173 | |
c2147a50 EGM |
174 | /* |
175 | * Early initcalls run before initializing SMP. | |
176 | * | |
177 | * Only for built-in code, not modules. | |
178 | */ | |
7929d407 | 179 | #define early_initcall(fn) __define_initcall(fn, early) |
c2147a50 | 180 | |
b3438f82 LT |
181 | /* |
182 | * A "pure" initcall has no dependencies on anything else, and purely | |
183 | * initializes variables that couldn't be statically initialized. | |
184 | * | |
185 | * This only exists for built-in code, not for modules. | |
96263d28 | 186 | * Keep main.c:initcall_level_names[] in sync. |
b3438f82 | 187 | */ |
7929d407 ML |
188 | #define pure_initcall(fn) __define_initcall(fn, 0) |
189 | ||
190 | #define core_initcall(fn) __define_initcall(fn, 1) | |
191 | #define core_initcall_sync(fn) __define_initcall(fn, 1s) | |
192 | #define postcore_initcall(fn) __define_initcall(fn, 2) | |
193 | #define postcore_initcall_sync(fn) __define_initcall(fn, 2s) | |
194 | #define arch_initcall(fn) __define_initcall(fn, 3) | |
195 | #define arch_initcall_sync(fn) __define_initcall(fn, 3s) | |
196 | #define subsys_initcall(fn) __define_initcall(fn, 4) | |
197 | #define subsys_initcall_sync(fn) __define_initcall(fn, 4s) | |
198 | #define fs_initcall(fn) __define_initcall(fn, 5) | |
199 | #define fs_initcall_sync(fn) __define_initcall(fn, 5s) | |
200 | #define rootfs_initcall(fn) __define_initcall(fn, rootfs) | |
201 | #define device_initcall(fn) __define_initcall(fn, 6) | |
202 | #define device_initcall_sync(fn) __define_initcall(fn, 6s) | |
203 | #define late_initcall(fn) __define_initcall(fn, 7) | |
204 | #define late_initcall_sync(fn) __define_initcall(fn, 7s) | |
1da177e4 LT |
205 | |
206 | #define __initcall(fn) device_initcall(fn) | |
207 | ||
b67067f1 | 208 | #define __exitcall(fn) \ |
1da177e4 LT |
209 | static exitcall_t __exitcall_##fn __exit_call = fn |
210 | ||
b67067f1 NP |
211 | #define console_initcall(fn) \ |
212 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 213 | __used __section(.con_initcall.init) = fn |
1da177e4 | 214 | |
b67067f1 NP |
215 | #define security_initcall(fn) \ |
216 | static initcall_t __initcall_##fn \ | |
3ff6eecc | 217 | __used __section(.security_initcall.init) = fn |
1da177e4 LT |
218 | |
219 | struct obs_kernel_param { | |
220 | const char *str; | |
221 | int (*setup_func)(char *); | |
222 | int early; | |
223 | }; | |
224 | ||
225 | /* | |
226 | * Only for really core code. See moduleparam.h for the normal way. | |
227 | * | |
228 | * Force the alignment so the compiler doesn't space elements of the | |
229 | * obs_kernel_param "array" too far apart in .init.setup. | |
230 | */ | |
231 | #define __setup_param(str, unique_id, fn, early) \ | |
c281b945 IM |
232 | static const char __setup_str_##unique_id[] __initconst \ |
233 | __aligned(1) = str; \ | |
234 | static struct obs_kernel_param __setup_##unique_id \ | |
235 | __used __section(.init.setup) \ | |
236 | __attribute__((aligned((sizeof(long))))) \ | |
1da177e4 LT |
237 | = { __setup_str_##unique_id, fn, early } |
238 | ||
c281b945 | 239 | #define __setup(str, fn) \ |
1da177e4 LT |
240 | __setup_param(str, fn, fn, 0) |
241 | ||
c281b945 IM |
242 | /* |
243 | * NOTE: fn is as per module_param, not __setup! | |
244 | * Emits warning if fn returns non-zero. | |
245 | */ | |
246 | #define early_param(str, fn) \ | |
1da177e4 LT |
247 | __setup_param(str, fn, fn, 1) |
248 | ||
c281b945 IM |
249 | #define early_param_on_off(str_on, str_off, var, config) \ |
250 | \ | |
251 | int var = IS_ENABLED(config); \ | |
252 | \ | |
253 | static int __init parse_##var##_on(char *arg) \ | |
254 | { \ | |
255 | var = 1; \ | |
256 | return 0; \ | |
257 | } \ | |
258 | __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \ | |
259 | \ | |
260 | static int __init parse_##var##_off(char *arg) \ | |
261 | { \ | |
262 | var = 0; \ | |
263 | return 0; \ | |
264 | } \ | |
bfb33bad LR |
265 | __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1) |
266 | ||
30d7e0d4 | 267 | /* Relies on boot_command_line being set */ |
1da177e4 | 268 | void __init parse_early_param(void); |
13977091 | 269 | void __init parse_early_options(char *cmdline); |
1da177e4 LT |
270 | #endif /* __ASSEMBLY__ */ |
271 | ||
1da177e4 LT |
272 | #else /* MODULE */ |
273 | ||
1da177e4 | 274 | #define __setup_param(str, unique_id, fn) /* nothing */ |
1da177e4 | 275 | #define __setup(str, func) /* nothing */ |
1da177e4 LT |
276 | #endif |
277 | ||
ab3bfca7 | 278 | /* Data marked not to be saved by software suspend */ |
07b3bb1e | 279 | #define __nosavedata __section(.data..nosave) |
1da177e4 | 280 | |
1da177e4 LT |
281 | #ifdef MODULE |
282 | #define __exit_p(x) x | |
283 | #else | |
284 | #define __exit_p(x) NULL | |
285 | #endif | |
286 | ||
287 | #endif /* _LINUX_INIT_H */ |