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