4 #include <linux/compiler.h>
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
15 * You should add __init immediately before the function name, like:
17 * static void __init initme(int x, int y)
19 * extern int z; z = x * y;
22 * If the function has a prototype somewhere, you can also add
23 * __init between closing brace of the prototype and semicolon:
25 * extern int initialize_foobar_device(int, int, int) __init;
27 * For initialized data:
28 * You should insert __initdata between the variable name and equal
29 * sign followed by value, e.g.:
31 * static int init_variable __initdata = 0;
32 * static char linux_logo[] __initdata = { 0x32, 0x36, ... };
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
38 * Also note, that this data cannot be "const".
41 /* These are for everybody (although not all archs will actually
42 discard it in modules) */
43 #define __init __section(.init.text) __cold
44 #define __initdata __section(.init.data)
45 #define __exitdata __section(.exit.data)
46 #define __exit_call __used __section(.exitcall.exit)
48 /* modpost check for section mismatches during the kernel build.
49 * A section mismatch happens when there are references from a
50 * code or data section to an init section (both code or data).
51 * The init sections are (for most archs) discarded by the kernel
52 * when early init has completed so all such references are potential bugs.
53 * For exit sections the same issue exists.
54 * The following markers are used for the cases where the reference to
55 * the init/exit section (code or data) is valid and will teach modpost
56 * not to issue a warning.
57 * The markers follow same syntax rules as __init / __initdata. */
58 #define __init_refok noinline __section(.text.init.refok)
59 #define __initdata_refok __section(.data.init.refok)
60 #define __exit_refok noinline __section(.exit.text.refok)
65 #define __exitused __used
68 #define __exit __section(.exit.text) __exitused __cold
70 /* Used for HOTPLUG */
71 #define __devinit __section(.devinit.text) __cold
72 #define __devinitdata __section(.devinit.data)
73 #define __devinitconst __section(.devinit.rodata)
74 #define __devexit __section(.devexit.text) __exitused __cold
75 #define __devexitdata __section(.devexit.data)
76 #define __devexitconst __section(.devexit.rodata)
78 /* Used for HOTPLUG_CPU */
79 #define __cpuinit __section(.cpuinit.text) __cold
80 #define __cpuinitdata __section(.cpuinit.data)
81 #define __cpuinitconst __section(.cpuinit.rodata)
82 #define __cpuexit __section(.cpuexit.text) __exitused __cold
83 #define __cpuexitdata __section(.cpuexit.data)
84 #define __cpuexitconst __section(.cpuexit.rodata)
86 /* Used for MEMORY_HOTPLUG */
87 #define __meminit __section(.meminit.text) __cold
88 #define __meminitdata __section(.meminit.data)
89 #define __meminitconst __section(.meminit.rodata)
90 #define __memexit __section(.memexit.text) __exitused __cold
91 #define __memexitdata __section(.memexit.data)
92 #define __memexitconst __section(.memexit.rodata)
94 /* For assembly routines */
95 #define __INIT .section ".init.text","ax"
96 #define __INIT_REFOK .section ".text.init.refok","ax"
97 #define __FINIT .previous
99 #define __INITDATA .section ".init.data","aw"
100 #define __INITDATA_REFOK .section ".data.init.refok","aw"
102 #define __DEVINIT .section ".devinit.text", "ax"
103 #define __DEVINITDATA .section ".devinit.data", "aw"
105 #define __CPUINIT .section ".cpuinit.text", "ax"
106 #define __CPUINITDATA .section ".cpuinit.data", "aw"
108 #define __MEMINIT .section ".meminit.text", "ax"
109 #define __MEMINITDATA .section ".meminit.data", "aw"
113 * Used for initialization calls..
115 typedef int (*initcall_t)(void);
116 typedef void (*exitcall_t)(void);
118 extern initcall_t __con_initcall_start[], __con_initcall_end[];
119 extern initcall_t __security_initcall_start[], __security_initcall_end[];
121 /* Defined in init/main.c */
122 extern char __initdata boot_command_line[];
123 extern char *saved_command_line;
124 extern unsigned int reset_devices;
126 /* used by init/main.c */
127 void setup_arch(char **);
128 void prepare_namespace(void);
136 /* initcalls are now grouped by functionality into separate
137 * subsections. Ordering inside the subsections is determined
139 * For backwards compatibility, initcall() puts the call in
140 * the device init subsection.
142 * The `id' arg to __define_initcall() is needed so that multiple initcalls
143 * can point at the same handler without causing duplicate-symbol build errors.
146 #define __define_initcall(level,fn,id) \
147 static initcall_t __initcall_##fn##id __used \
148 __attribute__((__section__(".initcall" level ".init"))) = fn
151 * A "pure" initcall has no dependencies on anything else, and purely
152 * initializes variables that couldn't be statically initialized.
154 * This only exists for built-in code, not for modules.
156 #define pure_initcall(fn) __define_initcall("0",fn,0)
158 #define core_initcall(fn) __define_initcall("1",fn,1)
159 #define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
160 #define postcore_initcall(fn) __define_initcall("2",fn,2)
161 #define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
162 #define arch_initcall(fn) __define_initcall("3",fn,3)
163 #define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
164 #define subsys_initcall(fn) __define_initcall("4",fn,4)
165 #define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
166 #define fs_initcall(fn) __define_initcall("5",fn,5)
167 #define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
168 #define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
169 #define device_initcall(fn) __define_initcall("6",fn,6)
170 #define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
171 #define late_initcall(fn) __define_initcall("7",fn,7)
172 #define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
174 #define __initcall(fn) device_initcall(fn)
176 #define __exitcall(fn) \
177 static exitcall_t __exitcall_##fn __exit_call = fn
179 #define console_initcall(fn) \
180 static initcall_t __initcall_##fn \
181 __used __section(.con_initcall.init) = fn
183 #define security_initcall(fn) \
184 static initcall_t __initcall_##fn \
185 __used __section(.security_initcall.init) = fn
187 struct obs_kernel_param {
189 int (*setup_func)(char *);
194 * Only for really core code. See moduleparam.h for the normal way.
196 * Force the alignment so the compiler doesn't space elements of the
197 * obs_kernel_param "array" too far apart in .init.setup.
199 #define __setup_param(str, unique_id, fn, early) \
200 static char __setup_str_##unique_id[] __initdata __aligned(1) = str; \
201 static struct obs_kernel_param __setup_##unique_id \
202 __used __section(.init.setup) \
203 __attribute__((aligned((sizeof(long))))) \
204 = { __setup_str_##unique_id, fn, early }
206 #define __setup_null_param(str, unique_id) \
207 __setup_param(str, unique_id, NULL, 0)
209 #define __setup(str, fn) \
210 __setup_param(str, fn, fn, 0)
212 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn
213 * returns non-zero. */
214 #define early_param(str, fn) \
215 __setup_param(str, fn, fn, 1)
217 /* Relies on boot_command_line being set */
218 void __init parse_early_param(void);
219 #endif /* __ASSEMBLY__ */
222 * module_init() - driver initialization entry point
223 * @x: function to be run at kernel boot time or module insertion
225 * module_init() will either be called during do_initcalls() (if
226 * builtin) or at module insertion time (if a module). There can only
229 #define module_init(x) __initcall(x);
232 * module_exit() - driver exit entry point
233 * @x: function to be run when driver is removed
235 * module_exit() will wrap the driver clean-up code
236 * with cleanup_module() when used with rmmod when
237 * the driver is a module. If the driver is statically
238 * compiled into the kernel, module_exit() has no effect.
239 * There can only be one per module.
241 #define module_exit(x) __exitcall(x);
245 /* Don't use these in modules, but some people do... */
246 #define core_initcall(fn) module_init(fn)
247 #define postcore_initcall(fn) module_init(fn)
248 #define arch_initcall(fn) module_init(fn)
249 #define subsys_initcall(fn) module_init(fn)
250 #define fs_initcall(fn) module_init(fn)
251 #define device_initcall(fn) module_init(fn)
252 #define late_initcall(fn) module_init(fn)
254 #define security_initcall(fn) module_init(fn)
256 /* These macros create a dummy inline: gcc 2.9x does not count alias
257 as usage, hence the `unused function' warning when __init functions
258 are declared static. We use the dummy __*_module_inline functions
259 both to kill the warning and check the type of the init/cleanup
262 /* Each module must use one module_init(), or one no_module_init */
263 #define module_init(initfn) \
264 static inline initcall_t __inittest(void) \
266 int init_module(void) __attribute__((alias(#initfn)));
268 /* This is only required if you want to be unloadable. */
269 #define module_exit(exitfn) \
270 static inline exitcall_t __exittest(void) \
272 void cleanup_module(void) __attribute__((alias(#exitfn)));
274 #define __setup_param(str, unique_id, fn) /* nothing */
275 #define __setup_null_param(str, unique_id) /* nothing */
276 #define __setup(str, func) /* nothing */
279 /* Data marked not to be saved by software suspend */
280 #define __nosavedata __section(.data.nosave)
282 /* This means "can be init if no module support, otherwise module load
284 #ifdef CONFIG_MODULES
285 #define __init_or_module
286 #define __initdata_or_module
288 #define __init_or_module __init
289 #define __initdata_or_module __initdata
290 #endif /*CONFIG_MODULES*/
292 /* Functions marked as __devexit may be discarded at kernel link time, depending
293 on config options. Newer versions of binutils detect references from
294 retained sections to discarded sections and flag an error. Pointers to
295 __devexit functions must use __devexit_p(function_name), the wrapper will
296 insert either the function_name or NULL, depending on the config options.
298 #if defined(MODULE) || defined(CONFIG_HOTPLUG)
299 #define __devexit_p(x) x
301 #define __devexit_p(x) NULL
305 #define __exit_p(x) x
307 #define __exit_p(x) NULL
310 #endif /* _LINUX_INIT_H */