Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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[]; |
Adrian Bunk | 77d4758 | 2006-03-25 03:07:39 -0800 | [diff] [blame] | 72 | |
| 73 | /* used by init/main.c */ |
| 74 | extern void setup_arch(char **); |
| 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | #endif |
| 77 | |
| 78 | #ifndef MODULE |
| 79 | |
| 80 | #ifndef __ASSEMBLY__ |
| 81 | |
| 82 | /* initcalls are now grouped by functionality into separate |
| 83 | * subsections. Ordering inside the subsections is determined |
| 84 | * by link order. |
| 85 | * For backwards compatibility, initcall() puts the call in |
| 86 | * the device init subsection. |
| 87 | */ |
| 88 | |
| 89 | #define __define_initcall(level,fn) \ |
| 90 | static initcall_t __initcall_##fn __attribute_used__ \ |
| 91 | __attribute__((__section__(".initcall" level ".init"))) = fn |
| 92 | |
| 93 | #define core_initcall(fn) __define_initcall("1",fn) |
| 94 | #define postcore_initcall(fn) __define_initcall("2",fn) |
| 95 | #define arch_initcall(fn) __define_initcall("3",fn) |
| 96 | #define subsys_initcall(fn) __define_initcall("4",fn) |
| 97 | #define fs_initcall(fn) __define_initcall("5",fn) |
| 98 | #define device_initcall(fn) __define_initcall("6",fn) |
| 99 | #define late_initcall(fn) __define_initcall("7",fn) |
| 100 | |
| 101 | #define __initcall(fn) device_initcall(fn) |
| 102 | |
| 103 | #define __exitcall(fn) \ |
| 104 | static exitcall_t __exitcall_##fn __exit_call = fn |
| 105 | |
| 106 | #define console_initcall(fn) \ |
| 107 | static initcall_t __initcall_##fn \ |
| 108 | __attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn |
| 109 | |
| 110 | #define security_initcall(fn) \ |
| 111 | static initcall_t __initcall_##fn \ |
| 112 | __attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn |
| 113 | |
| 114 | struct obs_kernel_param { |
| 115 | const char *str; |
| 116 | int (*setup_func)(char *); |
| 117 | int early; |
| 118 | }; |
| 119 | |
| 120 | /* |
| 121 | * Only for really core code. See moduleparam.h for the normal way. |
| 122 | * |
| 123 | * Force the alignment so the compiler doesn't space elements of the |
| 124 | * obs_kernel_param "array" too far apart in .init.setup. |
| 125 | */ |
| 126 | #define __setup_param(str, unique_id, fn, early) \ |
| 127 | static char __setup_str_##unique_id[] __initdata = str; \ |
| 128 | static struct obs_kernel_param __setup_##unique_id \ |
| 129 | __attribute_used__ \ |
| 130 | __attribute__((__section__(".init.setup"))) \ |
| 131 | __attribute__((aligned((sizeof(long))))) \ |
| 132 | = { __setup_str_##unique_id, fn, early } |
| 133 | |
| 134 | #define __setup_null_param(str, unique_id) \ |
| 135 | __setup_param(str, unique_id, NULL, 0) |
| 136 | |
| 137 | #define __setup(str, fn) \ |
| 138 | __setup_param(str, fn, fn, 0) |
| 139 | |
| 140 | #define __obsolete_setup(str) \ |
| 141 | __setup_null_param(str, __LINE__) |
| 142 | |
| 143 | /* NOTE: fn is as per module_param, not __setup! Emits warning if fn |
| 144 | * returns non-zero. */ |
| 145 | #define early_param(str, fn) \ |
| 146 | __setup_param(str, fn, fn, 1) |
| 147 | |
| 148 | /* Relies on saved_command_line being set */ |
| 149 | void __init parse_early_param(void); |
| 150 | #endif /* __ASSEMBLY__ */ |
| 151 | |
| 152 | /** |
| 153 | * module_init() - driver initialization entry point |
| 154 | * @x: function to be run at kernel boot time or module insertion |
| 155 | * |
| 156 | * module_init() will either be called during do_initcalls (if |
| 157 | * builtin) or at module insertion time (if a module). There can only |
| 158 | * be one per module. |
| 159 | */ |
| 160 | #define module_init(x) __initcall(x); |
| 161 | |
| 162 | /** |
| 163 | * module_exit() - driver exit entry point |
| 164 | * @x: function to be run when driver is removed |
| 165 | * |
| 166 | * module_exit() will wrap the driver clean-up code |
| 167 | * with cleanup_module() when used with rmmod when |
| 168 | * the driver is a module. If the driver is statically |
| 169 | * compiled into the kernel, module_exit() has no effect. |
| 170 | * There can only be one per module. |
| 171 | */ |
| 172 | #define module_exit(x) __exitcall(x); |
| 173 | |
| 174 | #else /* MODULE */ |
| 175 | |
| 176 | /* Don't use these in modules, but some people do... */ |
| 177 | #define core_initcall(fn) module_init(fn) |
| 178 | #define postcore_initcall(fn) module_init(fn) |
| 179 | #define arch_initcall(fn) module_init(fn) |
| 180 | #define subsys_initcall(fn) module_init(fn) |
| 181 | #define fs_initcall(fn) module_init(fn) |
| 182 | #define device_initcall(fn) module_init(fn) |
| 183 | #define late_initcall(fn) module_init(fn) |
| 184 | |
| 185 | #define security_initcall(fn) module_init(fn) |
| 186 | |
| 187 | /* These macros create a dummy inline: gcc 2.9x does not count alias |
| 188 | as usage, hence the `unused function' warning when __init functions |
| 189 | are declared static. We use the dummy __*_module_inline functions |
| 190 | both to kill the warning and check the type of the init/cleanup |
| 191 | function. */ |
| 192 | |
| 193 | /* Each module must use one module_init(), or one no_module_init */ |
| 194 | #define module_init(initfn) \ |
| 195 | static inline initcall_t __inittest(void) \ |
| 196 | { return initfn; } \ |
| 197 | int init_module(void) __attribute__((alias(#initfn))); |
| 198 | |
| 199 | /* This is only required if you want to be unloadable. */ |
| 200 | #define module_exit(exitfn) \ |
| 201 | static inline exitcall_t __exittest(void) \ |
| 202 | { return exitfn; } \ |
| 203 | void cleanup_module(void) __attribute__((alias(#exitfn))); |
| 204 | |
| 205 | #define __setup_param(str, unique_id, fn) /* nothing */ |
| 206 | #define __setup_null_param(str, unique_id) /* nothing */ |
| 207 | #define __setup(str, func) /* nothing */ |
| 208 | #define __obsolete_setup(str) /* nothing */ |
| 209 | #endif |
| 210 | |
| 211 | /* Data marked not to be saved by software_suspend() */ |
| 212 | #define __nosavedata __attribute__ ((__section__ (".data.nosave"))) |
| 213 | |
| 214 | /* This means "can be init if no module support, otherwise module load |
| 215 | may call it." */ |
| 216 | #ifdef CONFIG_MODULES |
| 217 | #define __init_or_module |
| 218 | #define __initdata_or_module |
| 219 | #else |
| 220 | #define __init_or_module __init |
| 221 | #define __initdata_or_module __initdata |
| 222 | #endif /*CONFIG_MODULES*/ |
| 223 | |
| 224 | #ifdef CONFIG_HOTPLUG |
| 225 | #define __devinit |
| 226 | #define __devinitdata |
| 227 | #define __devexit |
| 228 | #define __devexitdata |
| 229 | #else |
| 230 | #define __devinit __init |
| 231 | #define __devinitdata __initdata |
| 232 | #define __devexit __exit |
| 233 | #define __devexitdata __exitdata |
| 234 | #endif |
| 235 | |
Ashok Raj | e6982c6 | 2005-06-25 14:54:58 -0700 | [diff] [blame] | 236 | #ifdef CONFIG_HOTPLUG_CPU |
| 237 | #define __cpuinit |
| 238 | #define __cpuinitdata |
| 239 | #define __cpuexit |
| 240 | #define __cpuexitdata |
| 241 | #else |
| 242 | #define __cpuinit __init |
| 243 | #define __cpuinitdata __initdata |
| 244 | #define __cpuexit __exit |
| 245 | #define __cpuexitdata __exitdata |
| 246 | #endif |
| 247 | |
Matt Tolentino | c09b424 | 2006-01-17 07:03:44 +0100 | [diff] [blame] | 248 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |