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 const char linux_logo[] __initconst = { 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 __section(.init.text) __cold notrace
44 #define __initdata __section(.init.data)
45 #define __initconst __section(.init.rodata)
46 #define __exitdata __section(.exit.data)
47 #define __exit_call __used __section(.exitcall.exit)
48
49 /* modpost check for section mismatches during the kernel build.
50 * A section mismatch happens when there are references from a
51 * code or data section to an init section (both code or data).
52 * The init sections are (for most archs) discarded by the kernel
53 * when early init has completed so all such references are potential bugs.
54 * For exit sections the same issue exists.
55 * The following markers are used for the cases where the reference to
56 * the *init / *exit section (code or data) is valid and will teach
57 * modpost not to issue a warning.
58 * The markers follow same syntax rules as __init / __initdata. */
59 #define __ref __section(.ref.text) noinline
60 #define __refdata __section(.ref.data)
61 #define __refconst __section(.ref.rodata)
62
63 /* compatibility defines */
64 #define __init_refok __ref
65 #define __initdata_refok __refdata
66 #define __exit_refok __ref
67
68
69 #ifdef MODULE
70 #define __exitused
71 #else
72 #define __exitused __used
73 #endif
74
75 #define __exit __section(.exit.text) __exitused __cold
76
77 /* Used for HOTPLUG */
78 #define __devinit __section(.devinit.text) __cold
79 #define __devinitdata __section(.devinit.data)
80 #define __devinitconst __section(.devinit.rodata)
81 #define __devexit __section(.devexit.text) __exitused __cold
82 #define __devexitdata __section(.devexit.data)
83 #define __devexitconst __section(.devexit.rodata)
84
85 /* Used for HOTPLUG_CPU */
86 #define __cpuinit __section(.cpuinit.text) __cold
87 #define __cpuinitdata __section(.cpuinit.data)
88 #define __cpuinitconst __section(.cpuinit.rodata)
89 #define __cpuexit __section(.cpuexit.text) __exitused __cold
90 #define __cpuexitdata __section(.cpuexit.data)
91 #define __cpuexitconst __section(.cpuexit.rodata)
92
93 /* Used for MEMORY_HOTPLUG */
94 #define __meminit __section(.meminit.text) __cold
95 #define __meminitdata __section(.meminit.data)
96 #define __meminitconst __section(.meminit.rodata)
97 #define __memexit __section(.memexit.text) __exitused __cold
98 #define __memexitdata __section(.memexit.data)
99 #define __memexitconst __section(.memexit.rodata)
100
101 /* For assembly routines */
102 #define __HEAD .section ".head.text","ax"
103 #define __INIT .section ".init.text","ax"
104 #define __FINIT .previous
105
106 #define __INITDATA .section ".init.data","aw",%progbits
107 #define __INITRODATA .section ".init.rodata","a",%progbits
108 #define __FINITDATA .previous
109
110 #define __DEVINIT .section ".devinit.text", "ax"
111 #define __DEVINITDATA .section ".devinit.data", "aw"
112 #define __DEVINITRODATA .section ".devinit.rodata", "a"
113
114 #define __CPUINIT .section ".cpuinit.text", "ax"
115 #define __CPUINITDATA .section ".cpuinit.data", "aw"
116 #define __CPUINITRODATA .section ".cpuinit.rodata", "a"
117
118 #define __MEMINIT .section ".meminit.text", "ax"
119 #define __MEMINITDATA .section ".meminit.data", "aw"
120 #define __MEMINITRODATA .section ".meminit.rodata", "a"
121
122 /* silence warnings when references are OK */
123 #define __REF .section ".ref.text", "ax"
124 #define __REFDATA .section ".ref.data", "aw"
125 #define __REFCONST .section ".ref.rodata", "a"
126
127 #ifndef __ASSEMBLY__
128 /*
129 * Used for initialization calls..
130 */
131 typedef int (*initcall_t)(void);
132 typedef void (*exitcall_t)(void);
133
134 extern initcall_t __con_initcall_start[], __con_initcall_end[];
135 extern initcall_t __security_initcall_start[], __security_initcall_end[];
136
137 /* Used for contructor calls. */
138 typedef void (*ctor_fn_t)(void);
139
140 /* Defined in init/main.c */
141 extern int do_one_initcall(initcall_t fn);
142 extern char __initdata boot_command_line[];
143 extern char *saved_command_line;
144 extern unsigned int reset_devices;
145
146 /* used by init/main.c */
147 void setup_arch(char **);
148 void prepare_namespace(void);
149
150 extern void (*late_time_init)(void);
151
152 extern int initcall_debug;
153
154 #endif
155
156 #ifndef MODULE
157
158 #ifndef __ASSEMBLY__
159
160 /* initcalls are now grouped by functionality into separate
161 * subsections. Ordering inside the subsections is determined
162 * by link order.
163 * For backwards compatibility, initcall() puts the call in
164 * the device init subsection.
165 *
166 * The `id' arg to __define_initcall() is needed so that multiple initcalls
167 * can point at the same handler without causing duplicate-symbol build errors.
168 */
169
170 #define __define_initcall(level,fn,id) \
171 static initcall_t __initcall_##fn##id __used \
172 __attribute__((__section__(".initcall" level ".init"))) = fn
173
174 /*
175 * Early initcalls run before initializing SMP.
176 *
177 * Only for built-in code, not modules.
178 */
179 #define early_initcall(fn) __define_initcall("early",fn,early)
180
181 /*
182 * A "pure" initcall has no dependencies on anything else, and purely
183 * initializes variables that couldn't be statically initialized.
184 *
185 * This only exists for built-in code, not for modules.
186 */
187 #define pure_initcall(fn) __define_initcall("",fn,0)
188
189 #define core_initcall(fn) __define_initcall("1",fn,1)
190 #define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
191 #define postcore_initcall(fn) __define_initcall("2",fn,2)
192 #define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
193 #define arch_initcall(fn) __define_initcall("3",fn,3)
194 #define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
195 #define subsys_initcall(fn) __define_initcall("4",fn,4)
196 #define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
197 #define fs_initcall(fn) __define_initcall("5",fn,5)
198 #define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
199 #define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
200 #define device_initcall(fn) __define_initcall("6",fn,6)
201 #define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
202 #define late_initcall(fn) __define_initcall("7",fn,7)
203 #define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
204
205 #define __initcall(fn) device_initcall(fn)
206
207 #define __exitcall(fn) \
208 static exitcall_t __exitcall_##fn __exit_call = fn
209
210 #define console_initcall(fn) \
211 static initcall_t __initcall_##fn \
212 __used __section(.con_initcall.init) = fn
213
214 #define security_initcall(fn) \
215 static initcall_t __initcall_##fn \
216 __used __section(.security_initcall.init) = fn
217
218 struct obs_kernel_param {
219 const char *str;
220 int (*setup_func)(char *);
221 int early;
222 };
223
224 /*
225 * Only for really core code. See moduleparam.h for the normal way.
226 *
227 * Force the alignment so the compiler doesn't space elements of the
228 * obs_kernel_param "array" too far apart in .init.setup.
229 */
230 #define __setup_param(str, unique_id, fn, early) \
231 static const char __setup_str_##unique_id[] __initconst \
232 __aligned(1) = str; \
233 static struct obs_kernel_param __setup_##unique_id \
234 __used __section(.init.setup) \
235 __attribute__((aligned((sizeof(long))))) \
236 = { __setup_str_##unique_id, fn, early }
237
238 #define __setup(str, fn) \
239 __setup_param(str, fn, fn, 0)
240
241 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn
242 * returns non-zero. */
243 #define early_param(str, fn) \
244 __setup_param(str, fn, fn, 1)
245
246 /* Relies on boot_command_line being set */
247 void __init parse_early_param(void);
248 void __init parse_early_options(char *cmdline);
249 #endif /* __ASSEMBLY__ */
250
251 /**
252 * module_init() - driver initialization entry point
253 * @x: function to be run at kernel boot time or module insertion
254 *
255 * module_init() will either be called during do_initcalls() (if
256 * builtin) or at module insertion time (if a module). There can only
257 * be one per module.
258 */
259 #define module_init(x) __initcall(x);
260
261 /**
262 * module_exit() - driver exit entry point
263 * @x: function to be run when driver is removed
264 *
265 * module_exit() will wrap the driver clean-up code
266 * with cleanup_module() when used with rmmod when
267 * the driver is a module. If the driver is statically
268 * compiled into the kernel, module_exit() has no effect.
269 * There can only be one per module.
270 */
271 #define module_exit(x) __exitcall(x);
272
273 #else /* MODULE */
274
275 /* Don't use these in modules, but some people do... */
276 #define early_initcall(fn) module_init(fn)
277 #define core_initcall(fn) module_init(fn)
278 #define postcore_initcall(fn) module_init(fn)
279 #define arch_initcall(fn) module_init(fn)
280 #define subsys_initcall(fn) module_init(fn)
281 #define fs_initcall(fn) module_init(fn)
282 #define device_initcall(fn) module_init(fn)
283 #define late_initcall(fn) module_init(fn)
284
285 #define security_initcall(fn) module_init(fn)
286
287 /* Each module must use one module_init(). */
288 #define module_init(initfn) \
289 static inline initcall_t __inittest(void) \
290 { return initfn; } \
291 int init_module(void) __attribute__((alias(#initfn)));
292
293 /* This is only required if you want to be unloadable. */
294 #define module_exit(exitfn) \
295 static inline exitcall_t __exittest(void) \
296 { return exitfn; } \
297 void cleanup_module(void) __attribute__((alias(#exitfn)));
298
299 #define __setup_param(str, unique_id, fn) /* nothing */
300 #define __setup(str, func) /* nothing */
301 #endif
302
303 /* Data marked not to be saved by software suspend */
304 #define __nosavedata __section(.data.nosave)
305
306 /* This means "can be init if no module support, otherwise module load
307 may call it." */
308 #ifdef CONFIG_MODULES
309 #define __init_or_module
310 #define __initdata_or_module
311 #define __initconst_or_module
312 #define __INIT_OR_MODULE .text
313 #define __INITDATA_OR_MODULE .data
314 #define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits
315 #else
316 #define __init_or_module __init
317 #define __initdata_or_module __initdata
318 #define __initconst_or_module __initconst
319 #define __INIT_OR_MODULE __INIT
320 #define __INITDATA_OR_MODULE __INITDATA
321 #define __INITRODATA_OR_MODULE __INITRODATA
322 #endif /*CONFIG_MODULES*/
323
324 /* Functions marked as __devexit may be discarded at kernel link time, depending
325 on config options. Newer versions of binutils detect references from
326 retained sections to discarded sections and flag an error. Pointers to
327 __devexit functions must use __devexit_p(function_name), the wrapper will
328 insert either the function_name or NULL, depending on the config options.
329 */
330 #if defined(MODULE) || defined(CONFIG_HOTPLUG)
331 #define __devexit_p(x) x
332 #else
333 #define __devexit_p(x) NULL
334 #endif
335
336 #ifdef MODULE
337 #define __exit_p(x) x
338 #else
339 #define __exit_p(x) NULL
340 #endif
341
342 #endif /* _LINUX_INIT_H */
343
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