| 1 | #ifndef _LINUX_INIT_H |
| 2 | #define _LINUX_INIT_H |
| 3 | |
| 4 | #include <linux/compiler.h> |
| 5 | #include <linux/types.h> |
| 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: |
| 29 | * You should insert __initdata or __initconst between the variable name |
| 30 | * and equal sign followed by value, e.g.: |
| 31 | * |
| 32 | * static int init_variable __initdata = 0; |
| 33 | * static const char linux_logo[] __initconst = { 0x32, 0x36, ... }; |
| 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. |
| 38 | */ |
| 39 | |
| 40 | /* These are for everybody (although not all archs will actually |
| 41 | discard it in modules) */ |
| 42 | #define __init __section(.init.text) __cold notrace __latent_entropy |
| 43 | #define __initdata __section(.init.data) |
| 44 | #define __initconst __constsection(.init.rodata) |
| 45 | #define __exitdata __section(.exit.data) |
| 46 | #define __exit_call __used __section(.exitcall.exit) |
| 47 | |
| 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 | |
| 59 | /* |
| 60 | * modpost check for section mismatches during the kernel build. |
| 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. |
| 66 | * |
| 67 | * The following markers are used for the cases where the reference to |
| 68 | * the *init / *exit section (code or data) is valid and will teach |
| 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 | */ |
| 76 | #define __ref __section(.ref.text) noinline |
| 77 | #define __refdata __section(.ref.data) |
| 78 | #define __refconst __constsection(.ref.rodata) |
| 79 | |
| 80 | #ifdef MODULE |
| 81 | #define __exitused |
| 82 | #else |
| 83 | #define __exitused __used |
| 84 | #endif |
| 85 | |
| 86 | #define __exit __section(.exit.text) __exitused __cold notrace |
| 87 | |
| 88 | /* Used for MEMORY_HOTPLUG */ |
| 89 | #define __meminit __section(.meminit.text) __cold notrace \ |
| 90 | __latent_entropy |
| 91 | #define __meminitdata __section(.meminit.data) |
| 92 | #define __meminitconst __constsection(.meminit.rodata) |
| 93 | #define __memexit __section(.memexit.text) __exitused __cold notrace |
| 94 | #define __memexitdata __section(.memexit.data) |
| 95 | #define __memexitconst __constsection(.memexit.rodata) |
| 96 | |
| 97 | /* For assembly routines */ |
| 98 | #define __HEAD .section ".head.text","ax" |
| 99 | #define __INIT .section ".init.text","ax" |
| 100 | #define __FINIT .previous |
| 101 | |
| 102 | #define __INITDATA .section ".init.data","aw",%progbits |
| 103 | #define __INITRODATA .section ".init.rodata","a",%progbits |
| 104 | #define __FINITDATA .previous |
| 105 | |
| 106 | #define __MEMINIT .section ".meminit.text", "ax" |
| 107 | #define __MEMINITDATA .section ".meminit.data", "aw" |
| 108 | #define __MEMINITRODATA .section ".meminit.rodata", "a" |
| 109 | |
| 110 | /* silence warnings when references are OK */ |
| 111 | #define __REF .section ".ref.text", "ax" |
| 112 | #define __REFDATA .section ".ref.data", "aw" |
| 113 | #define __REFCONST .section ".ref.rodata", "a" |
| 114 | |
| 115 | #ifndef __ASSEMBLY__ |
| 116 | /* |
| 117 | * Used for initialization calls.. |
| 118 | */ |
| 119 | typedef int (*initcall_t)(void); |
| 120 | typedef void (*exitcall_t)(void); |
| 121 | |
| 122 | extern initcall_t __con_initcall_start[], __con_initcall_end[]; |
| 123 | extern initcall_t __security_initcall_start[], __security_initcall_end[]; |
| 124 | |
| 125 | /* Used for contructor calls. */ |
| 126 | typedef void (*ctor_fn_t)(void); |
| 127 | |
| 128 | /* Defined in init/main.c */ |
| 129 | extern int do_one_initcall(initcall_t fn); |
| 130 | extern char __initdata boot_command_line[]; |
| 131 | extern char *saved_command_line; |
| 132 | extern unsigned int reset_devices; |
| 133 | |
| 134 | /* used by init/main.c */ |
| 135 | void setup_arch(char **); |
| 136 | void prepare_namespace(void); |
| 137 | void __init load_default_modules(void); |
| 138 | int __init init_rootfs(void); |
| 139 | |
| 140 | #ifdef CONFIG_DEBUG_RODATA |
| 141 | void mark_rodata_ro(void); |
| 142 | #endif |
| 143 | |
| 144 | extern void (*late_time_init)(void); |
| 145 | |
| 146 | extern bool initcall_debug; |
| 147 | |
| 148 | #endif |
| 149 | |
| 150 | #ifndef MODULE |
| 151 | |
| 152 | #ifndef __ASSEMBLY__ |
| 153 | |
| 154 | /* |
| 155 | * initcalls are now grouped by functionality into separate |
| 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. |
| 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. |
| 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. |
| 168 | */ |
| 169 | |
| 170 | #define __define_initcall(fn, id) \ |
| 171 | static initcall_t __initcall_##fn##id __used \ |
| 172 | __attribute__((__section__(".initcall" #id ".init"))) = fn; |
| 173 | |
| 174 | /* |
| 175 | * Early initcalls run before initializing SMP. |
| 176 | * |
| 177 | * Only for built-in code, not modules. |
| 178 | */ |
| 179 | #define early_initcall(fn) __define_initcall(fn, early) |
| 180 | |
| 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. |
| 186 | * Keep main.c:initcall_level_names[] in sync. |
| 187 | */ |
| 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) |
| 205 | |
| 206 | #define __initcall(fn) device_initcall(fn) |
| 207 | |
| 208 | #define __exitcall(fn) \ |
| 209 | static exitcall_t __exitcall_##fn __exit_call = fn |
| 210 | |
| 211 | #define console_initcall(fn) \ |
| 212 | static initcall_t __initcall_##fn \ |
| 213 | __used __section(.con_initcall.init) = fn |
| 214 | |
| 215 | #define security_initcall(fn) \ |
| 216 | static initcall_t __initcall_##fn \ |
| 217 | __used __section(.security_initcall.init) = fn |
| 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) \ |
| 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))))) \ |
| 237 | = { __setup_str_##unique_id, fn, early } |
| 238 | |
| 239 | #define __setup(str, fn) \ |
| 240 | __setup_param(str, fn, fn, 0) |
| 241 | |
| 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) \ |
| 247 | __setup_param(str, fn, fn, 1) |
| 248 | |
| 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 | } \ |
| 265 | __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1) |
| 266 | |
| 267 | /* Relies on boot_command_line being set */ |
| 268 | void __init parse_early_param(void); |
| 269 | void __init parse_early_options(char *cmdline); |
| 270 | #endif /* __ASSEMBLY__ */ |
| 271 | |
| 272 | #else /* MODULE */ |
| 273 | |
| 274 | #define __setup_param(str, unique_id, fn) /* nothing */ |
| 275 | #define __setup(str, func) /* nothing */ |
| 276 | #endif |
| 277 | |
| 278 | /* Data marked not to be saved by software suspend */ |
| 279 | #define __nosavedata __section(.data..nosave) |
| 280 | |
| 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 */ |