blob: fb58c0493cf2f4524232ed95fd7b56371602ad28 [file] [log] [blame]
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150#endif
151
152#ifndef MODULE
153
154#ifndef __ASSEMBLY__
155
156/* initcalls are now grouped by functionality into separate
157 * subsections. Ordering inside the subsections is determined
158 * by link order.
159 * For backwards compatibility, initcall() puts the call in
160 * the device init subsection.
Andrew Morton735a7ff2006-10-27 11:42:37 -0700161 *
162 * The `id' arg to __define_initcall() is needed so that multiple initcalls
163 * can point at the same handler without causing duplicate-symbol build errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 */
165
Andrew Morton735a7ff2006-10-27 11:42:37 -0700166#define __define_initcall(level,fn,id) \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100167 static initcall_t __initcall_##fn##id __used \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 __attribute__((__section__(".initcall" level ".init"))) = fn
169
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800170/*
171 * A "pure" initcall has no dependencies on anything else, and purely
172 * initializes variables that couldn't be statically initialized.
173 *
174 * This only exists for built-in code, not for modules.
175 */
Michael Buesch73dd1162007-07-31 00:38:54 -0700176#define pure_initcall(fn) __define_initcall("0",fn,0)
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800177
Andrew Morton735a7ff2006-10-27 11:42:37 -0700178#define core_initcall(fn) __define_initcall("1",fn,1)
179#define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
180#define postcore_initcall(fn) __define_initcall("2",fn,2)
181#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
182#define arch_initcall(fn) __define_initcall("3",fn,3)
183#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
184#define subsys_initcall(fn) __define_initcall("4",fn,4)
185#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
186#define fs_initcall(fn) __define_initcall("5",fn,5)
187#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
Linus Torvalds8d610dd2006-12-11 12:12:04 -0800188#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
Andrew Morton735a7ff2006-10-27 11:42:37 -0700189#define device_initcall(fn) __define_initcall("6",fn,6)
190#define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
191#define late_initcall(fn) __define_initcall("7",fn,7)
192#define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194#define __initcall(fn) device_initcall(fn)
195
196#define __exitcall(fn) \
197 static exitcall_t __exitcall_##fn __exit_call = fn
198
199#define console_initcall(fn) \
200 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100201 __used __section(.con_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203#define security_initcall(fn) \
204 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100205 __used __section(.security_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
207struct obs_kernel_param {
208 const char *str;
209 int (*setup_func)(char *);
210 int early;
211};
212
213/*
214 * Only for really core code. See moduleparam.h for the normal way.
215 *
216 * Force the alignment so the compiler doesn't space elements of the
217 * obs_kernel_param "array" too far apart in .init.setup.
218 */
219#define __setup_param(str, unique_id, fn, early) \
Jan Beulichd5aa0da2007-10-16 23:29:34 -0700220 static char __setup_str_##unique_id[] __initdata __aligned(1) = str; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 static struct obs_kernel_param __setup_##unique_id \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100222 __used __section(.init.setup) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 __attribute__((aligned((sizeof(long))))) \
224 = { __setup_str_##unique_id, fn, early }
225
226#define __setup_null_param(str, unique_id) \
227 __setup_param(str, unique_id, NULL, 0)
228
229#define __setup(str, fn) \
230 __setup_param(str, fn, fn, 0)
231
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
233 * returns non-zero. */
234#define early_param(str, fn) \
235 __setup_param(str, fn, fn, 1)
236
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800237/* Relies on boot_command_line being set */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238void __init parse_early_param(void);
239#endif /* __ASSEMBLY__ */
240
241/**
242 * module_init() - driver initialization entry point
243 * @x: function to be run at kernel boot time or module insertion
244 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800245 * module_init() will either be called during do_initcalls() (if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 * builtin) or at module insertion time (if a module). There can only
247 * be one per module.
248 */
249#define module_init(x) __initcall(x);
250
251/**
252 * module_exit() - driver exit entry point
253 * @x: function to be run when driver is removed
254 *
255 * module_exit() will wrap the driver clean-up code
256 * with cleanup_module() when used with rmmod when
257 * the driver is a module. If the driver is statically
258 * compiled into the kernel, module_exit() has no effect.
259 * There can only be one per module.
260 */
261#define module_exit(x) __exitcall(x);
262
263#else /* MODULE */
264
265/* Don't use these in modules, but some people do... */
266#define core_initcall(fn) module_init(fn)
267#define postcore_initcall(fn) module_init(fn)
268#define arch_initcall(fn) module_init(fn)
269#define subsys_initcall(fn) module_init(fn)
270#define fs_initcall(fn) module_init(fn)
271#define device_initcall(fn) module_init(fn)
272#define late_initcall(fn) module_init(fn)
273
274#define security_initcall(fn) module_init(fn)
275
276/* These macros create a dummy inline: gcc 2.9x does not count alias
277 as usage, hence the `unused function' warning when __init functions
278 are declared static. We use the dummy __*_module_inline functions
279 both to kill the warning and check the type of the init/cleanup
280 function. */
281
282/* Each module must use one module_init(), or one no_module_init */
283#define module_init(initfn) \
284 static inline initcall_t __inittest(void) \
285 { return initfn; } \
286 int init_module(void) __attribute__((alias(#initfn)));
287
288/* This is only required if you want to be unloadable. */
289#define module_exit(exitfn) \
290 static inline exitcall_t __exittest(void) \
291 { return exitfn; } \
292 void cleanup_module(void) __attribute__((alias(#exitfn)));
293
294#define __setup_param(str, unique_id, fn) /* nothing */
295#define __setup_null_param(str, unique_id) /* nothing */
296#define __setup(str, func) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297#endif
298
Johannes Bergab3bfca2007-05-06 14:50:49 -0700299/* Data marked not to be saved by software suspend */
Sam Ravnborgf3fe8662008-01-20 18:54:48 +0100300#define __nosavedata __section(.data.nosave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
302/* This means "can be init if no module support, otherwise module load
303 may call it." */
304#ifdef CONFIG_MODULES
305#define __init_or_module
306#define __initdata_or_module
307#else
308#define __init_or_module __init
309#define __initdata_or_module __initdata
310#endif /*CONFIG_MODULES*/
311
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312/* Functions marked as __devexit may be discarded at kernel link time, depending
313 on config options. Newer versions of binutils detect references from
314 retained sections to discarded sections and flag an error. Pointers to
315 __devexit functions must use __devexit_p(function_name), the wrapper will
316 insert either the function_name or NULL, depending on the config options.
317 */
318#if defined(MODULE) || defined(CONFIG_HOTPLUG)
319#define __devexit_p(x) x
320#else
321#define __devexit_p(x) NULL
322#endif
323
324#ifdef MODULE
325#define __exit_p(x) x
326#else
327#define __exit_p(x) NULL
328#endif
329
330#endif /* _LINUX_INIT_H */