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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_INIT_H
2#define _LINUX_INIT_H
3
Linus Torvalds1da177e2005-04-16 15:20:36 -07004#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) */
Sam Ravnborgf3fe8662008-01-20 18:54:48 +010043#define __init __section(.init.text) __cold
44#define __initdata __section(.init.data)
Sam Ravnborg37c514e2008-02-19 21:00:18 +010045#define __initconst __section(.init.rodata)
Sam Ravnborgf3fe8662008-01-20 18:54:48 +010046#define __exitdata __section(.exit.data)
Adrian Bunk3ff6eec2008-01-24 22:16:20 +010047#define __exit_call __used __section(.exitcall.exit)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020049/* 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
Sam Ravnborg312b1482008-01-28 20:21:15 +010056 * the *init / *exit section (code or data) is valid and will teach
57 * modpost not to issue a warning.
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020058 * The markers follow same syntax rules as __init / __initdata. */
Sam Ravnborg312b1482008-01-28 20:21:15 +010059#define __ref __section(.ref.text) noinline
60#define __refdata __section(.ref.data)
61#define __refconst __section(.ref.rodata)
62
63/* backward compatibility note
64 * A few places hardcode the old section names:
65 * .text.init.refok
66 * .data.init.refok
67 * .exit.text.refok
68 * They should be converted to use the defines from this file
69 */
70
71/* compatibility defines */
72#define __init_refok __ref
73#define __initdata_refok __refdata
74#define __exit_refok __ref
75
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020076
Linus Torvalds1da177e2005-04-16 15:20:36 -070077#ifdef MODULE
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010078#define __exitused
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#else
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010080#define __exitused __used
Linus Torvalds1da177e2005-04-16 15:20:36 -070081#endif
82
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010083#define __exit __section(.exit.text) __exitused __cold
84
85/* Used for HOTPLUG */
86#define __devinit __section(.devinit.text) __cold
87#define __devinitdata __section(.devinit.data)
88#define __devinitconst __section(.devinit.rodata)
89#define __devexit __section(.devexit.text) __exitused __cold
90#define __devexitdata __section(.devexit.data)
91#define __devexitconst __section(.devexit.rodata)
92
93/* Used for HOTPLUG_CPU */
94#define __cpuinit __section(.cpuinit.text) __cold
95#define __cpuinitdata __section(.cpuinit.data)
96#define __cpuinitconst __section(.cpuinit.rodata)
97#define __cpuexit __section(.cpuexit.text) __exitused __cold
98#define __cpuexitdata __section(.cpuexit.data)
99#define __cpuexitconst __section(.cpuexit.rodata)
100
101/* Used for MEMORY_HOTPLUG */
102#define __meminit __section(.meminit.text) __cold
103#define __meminitdata __section(.meminit.data)
104#define __meminitconst __section(.meminit.rodata)
105#define __memexit __section(.memexit.text) __exitused __cold
106#define __memexitdata __section(.memexit.data)
107#define __memexitconst __section(.memexit.rodata)
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109/* For assembly routines */
Sam Ravnborg37c514e2008-02-19 21:00:18 +0100110#define __HEAD .section ".head.text","ax"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111#define __INIT .section ".init.text","ax"
Prarit Bhargava86c0baf2007-05-02 19:27:05 +0200112#define __FINIT .previous
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100113
Prarit Bhargava838c4112007-05-15 01:41:43 -0700114#define __INITDATA .section ".init.data","aw"
Ingo Molnar9f9975a2008-02-06 22:39:45 +0100115#define __FINITDATA .previous
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100117#define __DEVINIT .section ".devinit.text", "ax"
118#define __DEVINITDATA .section ".devinit.data", "aw"
119
120#define __CPUINIT .section ".cpuinit.text", "ax"
121#define __CPUINITDATA .section ".cpuinit.data", "aw"
122
123#define __MEMINIT .section ".meminit.text", "ax"
124#define __MEMINITDATA .section ".meminit.data", "aw"
125
Sam Ravnborg312b1482008-01-28 20:21:15 +0100126/* silence warnings when references are OK */
127#define __REF .section ".ref.text", "ax"
128#define __REFDATA .section ".ref.data", "aw"
129#define __REFCONST .section ".ref.rodata", "aw"
Sam Ravnborg312b1482008-01-28 20:21:15 +0100130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131#ifndef __ASSEMBLY__
132/*
133 * Used for initialization calls..
134 */
135typedef int (*initcall_t)(void);
136typedef void (*exitcall_t)(void);
137
138extern initcall_t __con_initcall_start[], __con_initcall_end[];
139extern initcall_t __security_initcall_start[], __security_initcall_end[];
140
141/* Defined in init/main.c */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800142extern char __initdata boot_command_line[];
143extern char *saved_command_line;
Vivek Goyal7e962872006-09-27 01:50:44 -0700144extern unsigned int reset_devices;
Adrian Bunk77d47582006-03-25 03:07:39 -0800145
146/* used by init/main.c */
Adrian Bunk46595392007-05-08 00:24:47 -0700147void setup_arch(char **);
148void prepare_namespace(void);
Adrian Bunk77d47582006-03-25 03:07:39 -0800149
Adrian Bunk7d195a52008-04-29 00:59:18 -0700150extern void (*late_time_init)(void);
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152#endif
153
154#ifndef MODULE
155
156#ifndef __ASSEMBLY__
157
158/* initcalls are now grouped by functionality into separate
159 * subsections. Ordering inside the subsections is determined
160 * by link order.
161 * For backwards compatibility, initcall() puts the call in
162 * the device init subsection.
Andrew Morton735a7ff2006-10-27 11:42:37 -0700163 *
164 * The `id' arg to __define_initcall() is needed so that multiple initcalls
165 * can point at the same handler without causing duplicate-symbol build errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 */
167
Andrew Morton735a7ff2006-10-27 11:42:37 -0700168#define __define_initcall(level,fn,id) \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100169 static initcall_t __initcall_##fn##id __used \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 __attribute__((__section__(".initcall" level ".init"))) = fn
171
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800172/*
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700173 * Early initcalls run before initializing SMP.
174 *
175 * Only for built-in code, not modules.
176 */
177#define early_initcall(fn) __define_initcall("early",fn,early)
178
179/*
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800180 * A "pure" initcall has no dependencies on anything else, and purely
181 * initializes variables that couldn't be statically initialized.
182 *
183 * This only exists for built-in code, not for modules.
184 */
Michael Buesch73dd1162007-07-31 00:38:54 -0700185#define pure_initcall(fn) __define_initcall("0",fn,0)
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800186
Andrew Morton735a7ff2006-10-27 11:42:37 -0700187#define core_initcall(fn) __define_initcall("1",fn,1)
188#define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
189#define postcore_initcall(fn) __define_initcall("2",fn,2)
190#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
191#define arch_initcall(fn) __define_initcall("3",fn,3)
192#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
193#define subsys_initcall(fn) __define_initcall("4",fn,4)
194#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
195#define fs_initcall(fn) __define_initcall("5",fn,5)
196#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
Linus Torvalds8d610dd2006-12-11 12:12:04 -0800197#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
Andrew Morton735a7ff2006-10-27 11:42:37 -0700198#define device_initcall(fn) __define_initcall("6",fn,6)
199#define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
200#define late_initcall(fn) __define_initcall("7",fn,7)
201#define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203#define __initcall(fn) device_initcall(fn)
204
205#define __exitcall(fn) \
206 static exitcall_t __exitcall_##fn __exit_call = fn
207
208#define console_initcall(fn) \
209 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100210 __used __section(.con_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212#define security_initcall(fn) \
213 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100214 __used __section(.security_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216struct obs_kernel_param {
217 const char *str;
218 int (*setup_func)(char *);
219 int early;
220};
221
222/*
223 * Only for really core code. See moduleparam.h for the normal way.
224 *
225 * Force the alignment so the compiler doesn't space elements of the
226 * obs_kernel_param "array" too far apart in .init.setup.
227 */
228#define __setup_param(str, unique_id, fn, early) \
Jan Beulichd5aa0da2007-10-16 23:29:34 -0700229 static char __setup_str_##unique_id[] __initdata __aligned(1) = str; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 static struct obs_kernel_param __setup_##unique_id \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100231 __used __section(.init.setup) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 __attribute__((aligned((sizeof(long))))) \
233 = { __setup_str_##unique_id, fn, early }
234
235#define __setup_null_param(str, unique_id) \
236 __setup_param(str, unique_id, NULL, 0)
237
238#define __setup(str, fn) \
239 __setup_param(str, fn, fn, 0)
240
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241/* 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
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800246/* Relies on boot_command_line being set */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247void __init parse_early_param(void);
248#endif /* __ASSEMBLY__ */
249
250/**
251 * module_init() - driver initialization entry point
252 * @x: function to be run at kernel boot time or module insertion
253 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800254 * module_init() will either be called during do_initcalls() (if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 * builtin) or at module insertion time (if a module). There can only
256 * be one per module.
257 */
258#define module_init(x) __initcall(x);
259
260/**
261 * module_exit() - driver exit entry point
262 * @x: function to be run when driver is removed
263 *
264 * module_exit() will wrap the driver clean-up code
265 * with cleanup_module() when used with rmmod when
266 * the driver is a module. If the driver is statically
267 * compiled into the kernel, module_exit() has no effect.
268 * There can only be one per module.
269 */
270#define module_exit(x) __exitcall(x);
271
272#else /* MODULE */
273
274/* Don't use these in modules, but some people do... */
275#define core_initcall(fn) module_init(fn)
276#define postcore_initcall(fn) module_init(fn)
277#define arch_initcall(fn) module_init(fn)
278#define subsys_initcall(fn) module_init(fn)
279#define fs_initcall(fn) module_init(fn)
280#define device_initcall(fn) module_init(fn)
281#define late_initcall(fn) module_init(fn)
282
283#define security_initcall(fn) module_init(fn)
284
Robert P. J. Day4500d062008-07-25 01:45:49 -0700285/* Each module must use one module_init(). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286#define module_init(initfn) \
287 static inline initcall_t __inittest(void) \
288 { return initfn; } \
289 int init_module(void) __attribute__((alias(#initfn)));
290
291/* This is only required if you want to be unloadable. */
292#define module_exit(exitfn) \
293 static inline exitcall_t __exittest(void) \
294 { return exitfn; } \
295 void cleanup_module(void) __attribute__((alias(#exitfn)));
296
297#define __setup_param(str, unique_id, fn) /* nothing */
298#define __setup_null_param(str, unique_id) /* nothing */
299#define __setup(str, func) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300#endif
301
Johannes Bergab3bfca2007-05-06 14:50:49 -0700302/* Data marked not to be saved by software suspend */
Sam Ravnborgf3fe8662008-01-20 18:54:48 +0100303#define __nosavedata __section(.data.nosave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
305/* This means "can be init if no module support, otherwise module load
306 may call it." */
307#ifdef CONFIG_MODULES
308#define __init_or_module
309#define __initdata_or_module
310#else
311#define __init_or_module __init
312#define __initdata_or_module __initdata
313#endif /*CONFIG_MODULES*/
314
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315/* Functions marked as __devexit may be discarded at kernel link time, depending
316 on config options. Newer versions of binutils detect references from
317 retained sections to discarded sections and flag an error. Pointers to
318 __devexit functions must use __devexit_p(function_name), the wrapper will
319 insert either the function_name or NULL, depending on the config options.
320 */
321#if defined(MODULE) || defined(CONFIG_HOTPLUG)
322#define __devexit_p(x) x
323#else
324#define __devexit_p(x) NULL
325#endif
326
327#ifdef MODULE
328#define __exit_p(x) x
329#else
330#define __exit_p(x) NULL
331#endif
332
333#endif /* _LINUX_INIT_H */