1 #ifndef _LINUX_INIT_H 2 #define _LINUX_INIT_H 3 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) */ 43 #define __init __attribute__ ((__section__ (".init.text"))) 44 #define __initdata __attribute__ ((__section__ (".init.data"))) 45 #define __exitdata __attribute__ ((__section__(".exit.data"))) 46 #define __exit_call __attribute_used__ __attribute__ ((__section__ (".exitcall.exit"))) 47 48 #ifdef MODULE 49 #define __exit __attribute__ ((__section__(".exit.text"))) 50 #else 51 #define __exit __attribute_used__ __attribute__ ((__section__(".exit.text"))) 52 #endif 53 54 /* For assembly routines */ 55 #ifdef CONFIG_HOTPLUG_CPU 56 #define __INIT .section ".text","ax" 57 #define __INITDATA .section ".data","aw" 58 #else 59 #define __INIT .section ".init.text","ax" 60 #define __INITDATA .section ".init.data","aw" 61 #endif 62 #define __FINIT .previous 63 64 #ifndef __ASSEMBLY__ 65 /* 66 * Used for initialization calls.. 67 */ 68 typedef int (*initcall_t)(void); 69 typedef void (*exitcall_t)(void); 70 71 extern initcall_t __con_initcall_start[], __con_initcall_end[]; 72 extern initcall_t __security_initcall_start[], __security_initcall_end[]; 73 74 /* Defined in init/main.c */ 75 extern char __initdata boot_command_line[]; 76 extern char *saved_command_line; 77 extern unsigned int reset_devices; 78 79 /* used by init/main.c */ 80 void setup_arch(char **); 81 void prepare_namespace(void); 82 83 #endif 84 85 #ifndef MODULE 86 87 #ifndef __ASSEMBLY__ 88 89 /* initcalls are now grouped by functionality into separate 90 * subsections. Ordering inside the subsections is determined 91 * by link order. 92 * For backwards compatibility, initcall() puts the call in 93 * the device init subsection. 94 * 95 * The `id' arg to __define_initcall() is needed so that multiple initcalls 96 * can point at the same handler without causing duplicate-symbol build errors. 97 */ 98 99 #define __define_initcall(level,fn,id) \ 100 static initcall_t __initcall_##fn##id __attribute_used__ \ 101 __attribute__((__section__(".initcall" level ".init"))) = fn 102 103 /* 104 * A "pure" initcall has no dependencies on anything else, and purely 105 * initializes variables that couldn't be statically initialized. 106 * 107 * This only exists for built-in code, not for modules. 108 */ 109 #define pure_initcall(fn) __define_initcall("0",fn,1) 110 111 #define core_initcall(fn) __define_initcall("1",fn,1) 112 #define core_initcall_sync(fn) __define_initcall("1s",fn,1s) 113 #define postcore_initcall(fn) __define_initcall("2",fn,2) 114 #define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s) 115 #define arch_initcall(fn) __define_initcall("3",fn,3) 116 #define arch_initcall_sync(fn) __define_initcall("3s",fn,3s) 117 #define subsys_initcall(fn) __define_initcall("4",fn,4) 118 #define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s) 119 #define fs_initcall(fn) __define_initcall("5",fn,5) 120 #define fs_initcall_sync(fn) __define_initcall("5s",fn,5s) 121 #define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs) 122 #define device_initcall(fn) __define_initcall("6",fn,6) 123 #define device_initcall_sync(fn) __define_initcall("6s",fn,6s) 124 #define late_initcall(fn) __define_initcall("7",fn,7) 125 #define late_initcall_sync(fn) __define_initcall("7s",fn,7s) 126 127 #define __initcall(fn) device_initcall(fn) 128 129 #define __exitcall(fn) \ 130 static exitcall_t __exitcall_##fn __exit_call = fn 131 132 #define console_initcall(fn) \ 133 static initcall_t __initcall_##fn \ 134 __attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn 135 136 #define security_initcall(fn) \ 137 static initcall_t __initcall_##fn \ 138 __attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn 139 140 struct obs_kernel_param { 141 const char *str; 142 int (*setup_func)(char *); 143 int early; 144 }; 145 146 /* 147 * Only for really core code. See moduleparam.h for the normal way. 148 * 149 * Force the alignment so the compiler doesn't space elements of the 150 * obs_kernel_param "array" too far apart in .init.setup. 151 */ 152 #define __setup_param(str, unique_id, fn, early) \ 153 static char __setup_str_##unique_id[] __initdata = str; \ 154 static struct obs_kernel_param __setup_##unique_id \ 155 __attribute_used__ \ 156 __attribute__((__section__(".init.setup"))) \ 157 __attribute__((aligned((sizeof(long))))) \ 158 = { __setup_str_##unique_id, fn, early } 159 160 #define __setup_null_param(str, unique_id) \ 161 __setup_param(str, unique_id, NULL, 0) 162 163 #define __setup(str, fn) \ 164 __setup_param(str, fn, fn, 0) 165 166 #define __obsolete_setup(str) \ 167 __setup_null_param(str, __LINE__) 168 169 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn 170 * returns non-zero. */ 171 #define early_param(str, fn) \ 172 __setup_param(str, fn, fn, 1) 173 174 /* Relies on boot_command_line being set */ 175 void __init parse_early_param(void); 176 #endif /* __ASSEMBLY__ */ 177 178 /** 179 * module_init() - driver initialization entry point 180 * @x: function to be run at kernel boot time or module insertion 181 * 182 * module_init() will either be called during do_initcalls() (if 183 * builtin) or at module insertion time (if a module). There can only 184 * be one per module. 185 */ 186 #define module_init(x) __initcall(x); 187 188 /** 189 * module_exit() - driver exit entry point 190 * @x: function to be run when driver is removed 191 * 192 * module_exit() will wrap the driver clean-up code 193 * with cleanup_module() when used with rmmod when 194 * the driver is a module. If the driver is statically 195 * compiled into the kernel, module_exit() has no effect. 196 * There can only be one per module. 197 */ 198 #define module_exit(x) __exitcall(x); 199 200 #else /* MODULE */ 201 202 /* Don't use these in modules, but some people do... */ 203 #define core_initcall(fn) module_init(fn) 204 #define postcore_initcall(fn) module_init(fn) 205 #define arch_initcall(fn) module_init(fn) 206 #define subsys_initcall(fn) module_init(fn) 207 #define fs_initcall(fn) module_init(fn) 208 #define device_initcall(fn) module_init(fn) 209 #define late_initcall(fn) module_init(fn) 210 211 #define security_initcall(fn) module_init(fn) 212 213 /* These macros create a dummy inline: gcc 2.9x does not count alias 214 as usage, hence the `unused function' warning when __init functions 215 are declared static. We use the dummy __*_module_inline functions 216 both to kill the warning and check the type of the init/cleanup 217 function. */ 218 219 /* Each module must use one module_init(), or one no_module_init */ 220 #define module_init(initfn) \ 221 static inline initcall_t __inittest(void) \ 222 { return initfn; } \ 223 int init_module(void) __attribute__((alias(#initfn))); 224 225 /* This is only required if you want to be unloadable. */ 226 #define module_exit(exitfn) \ 227 static inline exitcall_t __exittest(void) \ 228 { return exitfn; } \ 229 void cleanup_module(void) __attribute__((alias(#exitfn))); 230 231 #define __setup_param(str, unique_id, fn) /* nothing */ 232 #define __setup_null_param(str, unique_id) /* nothing */ 233 #define __setup(str, func) /* nothing */ 234 #define __obsolete_setup(str) /* nothing */ 235 #endif 236 237 /* Data marked not to be saved by software suspend */ 238 #define __nosavedata __attribute__ ((__section__ (".data.nosave"))) 239 240 /* This means "can be init if no module support, otherwise module load 241 may call it." */ 242 #ifdef CONFIG_MODULES 243 #define __init_or_module 244 #define __initdata_or_module 245 #else 246 #define __init_or_module __init 247 #define __initdata_or_module __initdata 248 #endif /*CONFIG_MODULES*/ 249 250 #ifdef CONFIG_HOTPLUG 251 #define __devinit 252 #define __devinitdata 253 #define __devexit 254 #define __devexitdata 255 #else 256 #define __devinit __init 257 #define __devinitdata __initdata 258 #define __devexit __exit 259 #define __devexitdata __exitdata 260 #endif 261 262 #ifdef CONFIG_HOTPLUG_CPU 263 #define __cpuinit 264 #define __cpuinitdata 265 #define __cpuexit 266 #define __cpuexitdata 267 #else 268 #define __cpuinit __init 269 #define __cpuinitdata __initdata 270 #define __cpuexit __exit 271 #define __cpuexitdata __exitdata 272 #endif 273 274 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_ACPI_HOTPLUG_MEMORY) \ 275 || defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE) 276 #define __meminit 277 #define __meminitdata 278 #define __memexit 279 #define __memexitdata 280 #else 281 #define __meminit __init 282 #define __meminitdata __initdata 283 #define __memexit __exit 284 #define __memexitdata __exitdata 285 #endif 286 287 /* Functions marked as __devexit may be discarded at kernel link time, depending 288 on config options. Newer versions of binutils detect references from 289 retained sections to discarded sections and flag an error. Pointers to 290 __devexit functions must use __devexit_p(function_name), the wrapper will 291 insert either the function_name or NULL, depending on the config options. 292 */ 293 #if defined(MODULE) || defined(CONFIG_HOTPLUG) 294 #define __devexit_p(x) x 295 #else 296 #define __devexit_p(x) NULL 297 #endif 298 299 #ifdef MODULE 300 #define __exit_p(x) x 301 #else 302 #define __exit_p(x) NULL 303 #endif 304 305 #endif /* _LINUX_INIT_H */ 306