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 #define __INIT .section ".init.text","ax" 56 #define __FINIT .previous 57 #define __INITDATA .section ".init.data","aw" 58 59 #ifndef __ASSEMBLY__ 60 /* 61 * Used for initialization calls.. 62 */ 63 typedef int (*initcall_t)(void); 64 typedef void (*exitcall_t)(void); 65 66 extern initcall_t __con_initcall_start[], __con_initcall_end[]; 67 extern initcall_t __security_initcall_start[], __security_initcall_end[]; 68 69 /* Defined in init/main.c */ 70 extern char saved_command_line[]; 71 72 /* used by init/main.c */ 73 extern void setup_arch(char **); 74 75 #endif 76 77 #ifndef MODULE 78 79 #ifndef __ASSEMBLY__ 80 81 /* initcalls are now grouped by functionality into separate 82 * subsections. Ordering inside the subsections is determined 83 * by link order. 84 * For backwards compatibility, initcall() puts the call in 85 * the device init subsection. 86 */ 87 88 #define __define_initcall(level,fn) \ 89 static initcall_t __initcall_##fn __attribute_used__ \ 90 __attribute__((__section__(".initcall" level ".init"))) = fn 91 92 #define core_initcall(fn) __define_initcall("1",fn) 93 #define postcore_initcall(fn) __define_initcall("2",fn) 94 #define arch_initcall(fn) __define_initcall("3",fn) 95 #define subsys_initcall(fn) __define_initcall("4",fn) 96 #define fs_initcall(fn) __define_initcall("5",fn) 97 #define device_initcall(fn) __define_initcall("6",fn) 98 #define late_initcall(fn) __define_initcall("7",fn) 99 100 #define __initcall(fn) device_initcall(fn) 101 102 #define __exitcall(fn) \ 103 static exitcall_t __exitcall_##fn __exit_call = fn 104 105 #define console_initcall(fn) \ 106 static initcall_t __initcall_##fn \ 107 __attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn 108 109 #define security_initcall(fn) \ 110 static initcall_t __initcall_##fn \ 111 __attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn 112 113 struct obs_kernel_param { 114 const char *str; 115 int (*setup_func)(char *); 116 int early; 117 }; 118 119 /* 120 * Only for really core code. See moduleparam.h for the normal way. 121 * 122 * Force the alignment so the compiler doesn't space elements of the 123 * obs_kernel_param "array" too far apart in .init.setup. 124 */ 125 #define __setup_param(str, unique_id, fn, early) \ 126 static char __setup_str_##unique_id[] __initdata = str; \ 127 static struct obs_kernel_param __setup_##unique_id \ 128 __attribute_used__ \ 129 __attribute__((__section__(".init.setup"))) \ 130 __attribute__((aligned((sizeof(long))))) \ 131 = { __setup_str_##unique_id, fn, early } 132 133 #define __setup_null_param(str, unique_id) \ 134 __setup_param(str, unique_id, NULL, 0) 135 136 #define __setup(str, fn) \ 137 __setup_param(str, fn, fn, 0) 138 139 #define __obsolete_setup(str) \ 140 __setup_null_param(str, __LINE__) 141 142 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn 143 * returns non-zero. */ 144 #define early_param(str, fn) \ 145 __setup_param(str, fn, fn, 1) 146 147 /* Relies on saved_command_line being set */ 148 void __init parse_early_param(void); 149 #endif /* __ASSEMBLY__ */ 150 151 /** 152 * module_init() - driver initialization entry point 153 * @x: function to be run at kernel boot time or module insertion 154 * 155 * module_init() will either be called during do_initcalls (if 156 * builtin) or at module insertion time (if a module). There can only 157 * be one per module. 158 */ 159 #define module_init(x) __initcall(x); 160 161 /** 162 * module_exit() - driver exit entry point 163 * @x: function to be run when driver is removed 164 * 165 * module_exit() will wrap the driver clean-up code 166 * with cleanup_module() when used with rmmod when 167 * the driver is a module. If the driver is statically 168 * compiled into the kernel, module_exit() has no effect. 169 * There can only be one per module. 170 */ 171 #define module_exit(x) __exitcall(x); 172 173 #else /* MODULE */ 174 175 /* Don't use these in modules, but some people do... */ 176 #define core_initcall(fn) module_init(fn) 177 #define postcore_initcall(fn) module_init(fn) 178 #define arch_initcall(fn) module_init(fn) 179 #define subsys_initcall(fn) module_init(fn) 180 #define fs_initcall(fn) module_init(fn) 181 #define device_initcall(fn) module_init(fn) 182 #define late_initcall(fn) module_init(fn) 183 184 #define security_initcall(fn) module_init(fn) 185 186 /* These macros create a dummy inline: gcc 2.9x does not count alias 187 as usage, hence the `unused function' warning when __init functions 188 are declared static. We use the dummy __*_module_inline functions 189 both to kill the warning and check the type of the init/cleanup 190 function. */ 191 192 /* Each module must use one module_init(), or one no_module_init */ 193 #define module_init(initfn) \ 194 static inline initcall_t __inittest(void) \ 195 { return initfn; } \ 196 int init_module(void) __attribute__((alias(#initfn))); 197 198 /* This is only required if you want to be unloadable. */ 199 #define module_exit(exitfn) \ 200 static inline exitcall_t __exittest(void) \ 201 { return exitfn; } \ 202 void cleanup_module(void) __attribute__((alias(#exitfn))); 203 204 #define __setup_param(str, unique_id, fn) /* nothing */ 205 #define __setup_null_param(str, unique_id) /* nothing */ 206 #define __setup(str, func) /* nothing */ 207 #define __obsolete_setup(str) /* nothing */ 208 #endif 209 210 /* Data marked not to be saved by software_suspend() */ 211 #define __nosavedata __attribute__ ((__section__ (".data.nosave"))) 212 213 /* This means "can be init if no module support, otherwise module load 214 may call it." */ 215 #ifdef CONFIG_MODULES 216 #define __init_or_module 217 #define __initdata_or_module 218 #else 219 #define __init_or_module __init 220 #define __initdata_or_module __initdata 221 #endif /*CONFIG_MODULES*/ 222 223 #ifdef CONFIG_HOTPLUG 224 #define __devinit 225 #define __devinitdata 226 #define __devexit 227 #define __devexitdata 228 #else 229 #define __devinit __init 230 #define __devinitdata __initdata 231 #define __devexit __exit 232 #define __devexitdata __exitdata 233 #endif 234 235 #ifdef CONFIG_HOTPLUG_CPU 236 #define __cpuinit 237 #define __cpuinitdata 238 #define __cpuexit 239 #define __cpuexitdata 240 #else 241 #define __cpuinit __init 242 #define __cpuinitdata __initdata 243 #define __cpuexit __exit 244 #define __cpuexitdata __exitdata 245 #endif 246 247 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_ACPI_HOTPLUG_MEMORY) \ 248 || defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE) 249 #define __meminit 250 #define __meminitdata 251 #define __memexit 252 #define __memexitdata 253 #else 254 #define __meminit __init 255 #define __meminitdata __initdata 256 #define __memexit __exit 257 #define __memexitdata __exitdata 258 #endif 259 260 /* Functions marked as __devexit may be discarded at kernel link time, depending 261 on config options. Newer versions of binutils detect references from 262 retained sections to discarded sections and flag an error. Pointers to 263 __devexit functions must use __devexit_p(function_name), the wrapper will 264 insert either the function_name or NULL, depending on the config options. 265 */ 266 #if defined(MODULE) || defined(CONFIG_HOTPLUG) 267 #define __devexit_p(x) x 268 #else 269 #define __devexit_p(x) NULL 270 #endif 271 272 #ifdef MODULE 273 #define __exit_p(x) x 274 #else 275 #define __exit_p(x) NULL 276 #endif 277 278 #endif /* _LINUX_INIT_H */ 279
