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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;
Geert Uytterhoevenae52bb22009-06-16 15:34:19 -070032 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 *
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) */
Steven Rostedtfed19392008-08-14 22:47:19 -040043#define __init __section(.init.text) __cold notrace
Sam Ravnborgf3fe8662008-01-20 18:54:48 +010044#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
Sam Ravnborg312b1482008-01-28 20:21:15 +010063/* compatibility defines */
64#define __init_refok __ref
65#define __initdata_refok __refdata
66#define __exit_refok __ref
67
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020068
Linus Torvalds1da177e2005-04-16 15:20:36 -070069#ifdef MODULE
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010070#define __exitused
Linus Torvalds1da177e2005-04-16 15:20:36 -070071#else
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010072#define __exitused __used
Linus Torvalds1da177e2005-04-16 15:20:36 -070073#endif
74
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010075#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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101/* For assembly routines */
Sam Ravnborg7923f902009-06-14 22:10:41 +0200102#define __HEAD .section ".head.text","ax"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103#define __INIT .section ".init.text","ax"
Prarit Bhargava86c0baf2007-05-02 19:27:05 +0200104#define __FINIT .previous
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100105
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100106#define __INITDATA .section ".init.data","aw",%progbits
107#define __INITRODATA .section ".init.rodata","a",%progbits
Ingo Molnar9f9975a2008-02-06 22:39:45 +0100108#define __FINITDATA .previous
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100110#define __DEVINIT .section ".devinit.text", "ax"
111#define __DEVINITDATA .section ".devinit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700112#define __DEVINITRODATA .section ".devinit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100113
114#define __CPUINIT .section ".cpuinit.text", "ax"
115#define __CPUINITDATA .section ".cpuinit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700116#define __CPUINITRODATA .section ".cpuinit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100117
118#define __MEMINIT .section ".meminit.text", "ax"
119#define __MEMINITDATA .section ".meminit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700120#define __MEMINITRODATA .section ".meminit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100121
Sam Ravnborg312b1482008-01-28 20:21:15 +0100122/* silence warnings when references are OK */
123#define __REF .section ".ref.text", "ax"
124#define __REFDATA .section ".ref.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700125#define __REFCONST .section ".ref.rodata", "a"
Sam Ravnborg312b1482008-01-28 20:21:15 +0100126
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127#ifndef __ASSEMBLY__
128/*
129 * Used for initialization calls..
130 */
131typedef int (*initcall_t)(void);
132typedef void (*exitcall_t)(void);
133
134extern initcall_t __con_initcall_start[], __con_initcall_end[];
135extern initcall_t __security_initcall_start[], __security_initcall_end[];
136
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700137/* Used for contructor calls. */
138typedef void (*ctor_fn_t)(void);
139
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140/* Defined in init/main.c */
Arjan van de Ven59f94152008-07-30 12:49:02 -0700141extern int do_one_initcall(initcall_t fn);
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
Arjan van de Venf2511772009-12-13 20:29:01 +0100152extern int initcall_debug;
153
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154#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.
Andrew Morton735a7ff2006-10-27 11:42:37 -0700165 *
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.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 */
169
Andrew Morton735a7ff2006-10-27 11:42:37 -0700170#define __define_initcall(level,fn,id) \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100171 static initcall_t __initcall_##fn##id __used \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 __attribute__((__section__(".initcall" level ".init"))) = fn
173
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800174/*
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700175 * 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/*
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800182 * 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 */
Michael Buesch73dd1162007-07-31 00:38:54 -0700187#define pure_initcall(fn) __define_initcall("0",fn,0)
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800188
Andrew Morton735a7ff2006-10-27 11:42:37 -0700189#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)
Linus Torvalds8d610dd2006-12-11 12:12:04 -0800199#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
Andrew Morton735a7ff2006-10-27 11:42:37 -0700200#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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
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 \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100212 __used __section(.con_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214#define security_initcall(fn) \
215 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100216 __used __section(.security_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
218struct 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) \
Jan Beulichfd6c3a82009-03-12 10:58:33 +0000231 static const char __setup_str_##unique_id[] __initconst \
232 __aligned(1) = str; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 static struct obs_kernel_param __setup_##unique_id \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100234 __used __section(.init.setup) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 __attribute__((aligned((sizeof(long))))) \
236 = { __setup_str_##unique_id, fn, early }
237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238#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);
Magnus Damm13977092009-03-30 14:37:25 -0700248void __init parse_early_options(char *cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249#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 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800255 * module_init() will either be called during do_initcalls() (if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 * 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... */
Borislav Petkov329bd412009-10-02 15:23:21 +0200276#define early_initcall(fn) module_init(fn)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277#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
Robert P. J. Day4500d062008-07-25 01:45:49 -0700287/* Each module must use one module_init(). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288#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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300#define __setup(str, func) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301#endif
302
Johannes Bergab3bfca2007-05-06 14:50:49 -0700303/* Data marked not to be saved by software suspend */
Denys Vlasenko07b3bb12010-02-20 01:03:52 +0100304#define __nosavedata __section(.data..nosave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
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
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100311#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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315#else
316#define __init_or_module __init
317#define __initdata_or_module __initdata
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100318#define __initconst_or_module __initconst
319#define __INIT_OR_MODULE __INIT
320#define __INITDATA_OR_MODULE __INITDATA
321#define __INITRODATA_OR_MODULE __INITRODATA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322#endif /*CONFIG_MODULES*/
323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324/* 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 */