1 #ifndef _LINUX_INIT_H 2 #define _LINUX_INIT_H 3 4 #include <linux/config.h> 5 #include <linux/compiler.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 between the variable name and equal 30 * sign followed by value, e.g.: 31 * 32 * static int init_variable __initdata = 0; 33 * static char linux_logo[] __initdata = { 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 * Also note, that this data cannot be "const". 40 */ 41 42 /* These are for everybody (although not all archs will actually 43 discard it in modules) */ 44 #define __init __attribute__ ((__section__ (".init.text"))) 45 #define __initdata __attribute__ ((__section__ (".init.data"))) 46 #define __exitdata __attribute__ ((__section__(".exit.data"))) 47 #define __exit_call __attribute_used__ __attribute__ ((__section__ (".exitcall.exit"))) 48 49 #ifdef MODULE 50 #define __exit __attribute__ ((__section__(".exit.text"))) 51 #else 52 #define __exit __attribute_used__ __attribute__ ((__section__(".exit.text"))) 53 #endif 54 55 /* For assembly routines */ 56 #define __INIT .section ".init.text","ax" 57 #define __FINIT .previous 58 #define __INITDATA .section ".init.data","aw" 59 60 #ifndef __ASSEMBLY__ 61 /* 62 * Used for initialization calls.. 63 */ 64 typedef int (*initcall_t)(void); 65 typedef void (*exitcall_t)(void); 66 67 extern initcall_t __con_initcall_start[], __con_initcall_end[]; 68 extern initcall_t __security_initcall_start[], __security_initcall_end[]; 69 70 /* Defined in init/main.c */ 71 extern char saved_command_line[]; 72 #endif 73 74 #ifndef MODULE 75 76 #ifndef __ASSEMBLY__ 77 78 /* initcalls are now grouped by functionality into separate 79 * subsections. Ordering inside the subsections is determined 80 * by link order. 81 * For backwards compatibility, initcall() puts the call in 82 * the device init subsection. 83 */ 84 85 #define __define_initcall(level,fn) \ 86 static initcall_t __initcall_##fn __attribute_used__ \ 87 __attribute__((__section__(".initcall" level ".init"))) = fn 88 89 #define core_initcall(fn) __define_initcall("1",fn) 90 #define postcore_initcall(fn) __define_initcall("2",fn) 91 #define arch_initcall(fn) __define_initcall("3",fn) 92 #define subsys_initcall(fn) __define_initcall("4",fn) 93 #define fs_initcall(fn) __define_initcall("5",fn) 94 #define device_initcall(fn) __define_initcall("6",fn) 95 #define late_initcall(fn) __define_initcall("7",fn) 96 97 #define __initcall(fn) device_initcall(fn) 98 99 #define __exitcall(fn) \ 100 static exitcall_t __exitcall_##fn __exit_call = fn 101 102 #define console_initcall(fn) \ 103 static initcall_t __initcall_##fn \ 104 __attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn 105 106 #define security_initcall(fn) \ 107 static initcall_t __initcall_##fn \ 108 __attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn 109 110 struct obs_kernel_param { 111 const char *str; 112 int (*setup_func)(char *); 113 int early; 114 }; 115 116 /* 117 * Only for really core code. See moduleparam.h for the normal way. 118 * 119 * Force the alignment so the compiler doesn't space elements of the 120 * obs_kernel_param "array" too far apart in .init.setup. 121 */ 122 #define __setup_param(str, unique_id, fn, early) \ 123 static char __setup_str_##unique_id[] __initdata = str; \ 124 static struct obs_kernel_param __setup_##unique_id \ 125 __attribute_used__ \ 126 __attribute__((__section__(".init.setup"))) \ 127 __attribute__((aligned((sizeof(long))))) \ 128 = { __setup_str_##unique_id, fn, early } 129 130 #define __setup_null_param(str, unique_id) \ 131 __setup_param(str, unique_id, NULL, 0) 132 133 #define __setup(str, fn) \ 134 __setup_param(str, fn, fn, 0) 135 136 #define __obsolete_setup(str) \ 137 __setup_null_param(str, __LINE__) 138 139 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn 140 * returns non-zero. */ 141 #define early_param(str, fn) \ 142 __setup_param(str, fn, fn, 1) 143 144 /* Relies on saved_command_line being set */ 145 void __init parse_early_param(void); 146 #endif /* __ASSEMBLY__ */ 147 148 /** 149 * module_init() - driver initialization entry point 150 * @x: function to be run at kernel boot time or module insertion 151 * 152 * module_init() will either be called during do_initcalls (if 153 * builtin) or at module insertion time (if a module). There can only 154 * be one per module. 155 */ 156 #define module_init(x) __initcall(x); 157 158 /** 159 * module_exit() - driver exit entry point 160 * @x: function to be run when driver is removed 161 * 162 * module_exit() will wrap the driver clean-up code 163 * with cleanup_module() when used with rmmod when 164 * the driver is a module. If the driver is statically 165 * compiled into the kernel, module_exit() has no effect. 166 * There can only be one per module. 167 */ 168 #define module_exit(x) __exitcall(x); 169 170 #else /* MODULE */ 171 172 /* Don't use these in modules, but some people do... */ 173 #define core_initcall(fn) module_init(fn) 174 #define postcore_initcall(fn) module_init(fn) 175 #define arch_initcall(fn) module_init(fn) 176 #define subsys_initcall(fn) module_init(fn) 177 #define fs_initcall(fn) module_init(fn) 178 #define device_initcall(fn) module_init(fn) 179 #define late_initcall(fn) module_init(fn) 180 181 #define security_initcall(fn) module_init(fn) 182 183 /* These macros create a dummy inline: gcc 2.9x does not count alias 184 as usage, hence the `unused function' warning when __init functions 185 are declared static. We use the dummy __*_module_inline functions 186 both to kill the warning and check the type of the init/cleanup 187 function. */ 188 189 /* Each module must use one module_init(), or one no_module_init */ 190 #define module_init(initfn) \ 191 static inline initcall_t __inittest(void) \ 192 { return initfn; } \ 193 int init_module(void) __attribute__((alias(#initfn))); 194 195 /* This is only required if you want to be unloadable. */ 196 #define module_exit(exitfn) \ 197 static inline exitcall_t __exittest(void) \ 198 { return exitfn; } \ 199 void cleanup_module(void) __attribute__((alias(#exitfn))); 200 201 #define __setup_param(str, unique_id, fn) /* nothing */ 202 #define __setup_null_param(str, unique_id) /* nothing */ 203 #define __setup(str, func) /* nothing */ 204 #define __obsolete_setup(str) /* nothing */ 205 #endif 206 207 /* Data marked not to be saved by software_suspend() */ 208 #define __nosavedata __attribute__ ((__section__ (".data.nosave"))) 209 210 /* This means "can be init if no module support, otherwise module load 211 may call it." */ 212 #ifdef CONFIG_MODULES 213 #define __init_or_module 214 #define __initdata_or_module 215 #else 216 #define __init_or_module __init 217 #define __initdata_or_module __initdata 218 #endif /*CONFIG_MODULES*/ 219 220 #ifdef CONFIG_HOTPLUG 221 #define __devinit 222 #define __devinitdata 223 #define __devexit 224 #define __devexitdata 225 #else 226 #define __devinit __init 227 #define __devinitdata __initdata 228 #define __devexit __exit 229 #define __devexitdata __exitdata 230 #endif 231 232 #ifdef CONFIG_HOTPLUG_CPU 233 #define __cpuinit 234 #define __cpuinitdata 235 #define __cpuexit 236 #define __cpuexitdata 237 #else 238 #define __cpuinit __init 239 #define __cpuinitdata __initdata 240 #define __cpuexit __exit 241 #define __cpuexitdata __exitdata 242 #endif 243 244 /* Functions marked as __devexit may be discarded at kernel link time, depending 245 on config options. Newer versions of binutils detect references from 246 retained sections to discarded sections and flag an error. Pointers to 247 __devexit functions must use __devexit_p(function_name), the wrapper will 248 insert either the function_name or NULL, depending on the config options. 249 */ 250 #if defined(MODULE) || defined(CONFIG_HOTPLUG) 251 #define __devexit_p(x) x 252 #else 253 #define __devexit_p(x) NULL 254 #endif 255 256 #ifdef MODULE 257 #define __exit_p(x) x 258 #else 259 #define __exit_p(x) NULL 260 #endif 261 262 #endif /* _LINUX_INIT_H */ 263