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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>
Rusty Russell2329abf2012-01-13 09:32:18 +10305#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006
7/* These macros are used to mark some functions or
8 * initialized data (doesn't apply to uninitialized data)
9 * as `initialization' functions. The kernel can take this
10 * as hint that the function is used only during the initialization
11 * phase and free up used memory resources after
12 *
13 * Usage:
14 * For functions:
15 *
16 * You should add __init immediately before the function name, like:
17 *
18 * static void __init initme(int x, int y)
19 * {
20 * extern int z; z = x * y;
21 * }
22 *
23 * If the function has a prototype somewhere, you can also add
24 * __init between closing brace of the prototype and semicolon:
25 *
26 * extern int initialize_foobar_device(int, int, int) __init;
27 *
28 * For initialized data:
29 * You should insert __initdata between the variable name and equal
30 * sign followed by value, e.g.:
31 *
32 * static int init_variable __initdata = 0;
Geert Uytterhoevenae52bb22009-06-16 15:34:19 -070033 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 *
35 * Don't forget to initialize data not at file scope, i.e. within a function,
36 * as gcc otherwise puts the data into the bss section and not into the init
37 * section.
38 *
39 * Also note, that this data cannot be "const".
40 */
41
42/* These are for everybody (although not all archs will actually
43 discard it in modules) */
Steven Rostedtfed19392008-08-14 22:47:19 -040044#define __init __section(.init.text) __cold notrace
Sam Ravnborgf3fe8662008-01-20 18:54:48 +010045#define __initdata __section(.init.data)
Sam Ravnborg37c514e2008-02-19 21:00:18 +010046#define __initconst __section(.init.rodata)
Sam Ravnborgf3fe8662008-01-20 18:54:48 +010047#define __exitdata __section(.exit.data)
Adrian Bunk3ff6eec2008-01-24 22:16:20 +010048#define __exit_call __used __section(.exitcall.exit)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020050/*
51 * modpost check for section mismatches during the kernel build.
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020052 * A section mismatch happens when there are references from a
53 * code or data section to an init section (both code or data).
54 * The init sections are (for most archs) discarded by the kernel
55 * when early init has completed so all such references are potential bugs.
56 * For exit sections the same issue exists.
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020057 *
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020058 * The following markers are used for the cases where the reference to
Sam Ravnborg312b1482008-01-28 20:21:15 +010059 * the *init / *exit section (code or data) is valid and will teach
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020060 * modpost not to issue a warning. Intended semantics is that a code or
61 * data tagged __ref* can reference code or data from init section without
62 * producing a warning (of course, no warning does not mean code is
63 * correct, so optimally document why the __ref is needed and why it's OK).
64 *
65 * The markers follow same syntax rules as __init / __initdata.
66 */
Sam Ravnborg312b1482008-01-28 20:21:15 +010067#define __ref __section(.ref.text) noinline
68#define __refdata __section(.ref.data)
69#define __refconst __section(.ref.rodata)
70
Sam Ravnborg312b1482008-01-28 20:21:15 +010071/* 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
Steven Rostedtf0201732011-04-12 19:06:39 -040083#define __exit __section(.exit.text) __exitused __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010084
85/* Used for HOTPLUG */
Steven Rostedtf0201732011-04-12 19:06:39 -040086#define __devinit __section(.devinit.text) __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010087#define __devinitdata __section(.devinit.data)
88#define __devinitconst __section(.devinit.rodata)
Steven Rostedtf0201732011-04-12 19:06:39 -040089#define __devexit __section(.devexit.text) __exitused __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010090#define __devexitdata __section(.devexit.data)
91#define __devexitconst __section(.devexit.rodata)
92
93/* Used for HOTPLUG_CPU */
Steven Rostedtf0201732011-04-12 19:06:39 -040094#define __cpuinit __section(.cpuinit.text) __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010095#define __cpuinitdata __section(.cpuinit.data)
96#define __cpuinitconst __section(.cpuinit.rodata)
Steven Rostedtf0201732011-04-12 19:06:39 -040097#define __cpuexit __section(.cpuexit.text) __exitused __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010098#define __cpuexitdata __section(.cpuexit.data)
99#define __cpuexitconst __section(.cpuexit.rodata)
100
101/* Used for MEMORY_HOTPLUG */
Steven Rostedtf0201732011-04-12 19:06:39 -0400102#define __meminit __section(.meminit.text) __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100103#define __meminitdata __section(.meminit.data)
104#define __meminitconst __section(.meminit.rodata)
Steven Rostedtf0201732011-04-12 19:06:39 -0400105#define __memexit __section(.memexit.text) __exitused __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100106#define __memexitdata __section(.memexit.data)
107#define __memexitconst __section(.memexit.rodata)
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109/* For assembly routines */
Sam Ravnborg7923f902009-06-14 22:10:41 +0200110#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
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100114#define __INITDATA .section ".init.data","aw",%progbits
115#define __INITRODATA .section ".init.rodata","a",%progbits
Ingo Molnar9f9975a2008-02-06 22:39:45 +0100116#define __FINITDATA .previous
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100118#define __DEVINIT .section ".devinit.text", "ax"
119#define __DEVINITDATA .section ".devinit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700120#define __DEVINITRODATA .section ".devinit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100121
122#define __CPUINIT .section ".cpuinit.text", "ax"
123#define __CPUINITDATA .section ".cpuinit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700124#define __CPUINITRODATA .section ".cpuinit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100125
126#define __MEMINIT .section ".meminit.text", "ax"
127#define __MEMINITDATA .section ".meminit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700128#define __MEMINITRODATA .section ".meminit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100129
Sam Ravnborg312b1482008-01-28 20:21:15 +0100130/* silence warnings when references are OK */
131#define __REF .section ".ref.text", "ax"
132#define __REFDATA .section ".ref.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700133#define __REFCONST .section ".ref.rodata", "a"
Sam Ravnborg312b1482008-01-28 20:21:15 +0100134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135#ifndef __ASSEMBLY__
136/*
137 * Used for initialization calls..
138 */
139typedef int (*initcall_t)(void);
140typedef void (*exitcall_t)(void);
141
142extern initcall_t __con_initcall_start[], __con_initcall_end[];
143extern initcall_t __security_initcall_start[], __security_initcall_end[];
144
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700145/* Used for contructor calls. */
146typedef void (*ctor_fn_t)(void);
147
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148/* Defined in init/main.c */
Arjan van de Ven59f94152008-07-30 12:49:02 -0700149extern int do_one_initcall(initcall_t fn);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800150extern char __initdata boot_command_line[];
151extern char *saved_command_line;
Vivek Goyal7e962872006-09-27 01:50:44 -0700152extern unsigned int reset_devices;
Adrian Bunk77d47582006-03-25 03:07:39 -0800153
154/* used by init/main.c */
Adrian Bunk46595392007-05-08 00:24:47 -0700155void setup_arch(char **);
156void prepare_namespace(void);
Adrian Bunk77d47582006-03-25 03:07:39 -0800157
Adrian Bunk7d195a52008-04-29 00:59:18 -0700158extern void (*late_time_init)(void);
159
Rusty Russell2329abf2012-01-13 09:32:18 +1030160extern bool initcall_debug;
Arjan van de Venf2511772009-12-13 20:29:01 +0100161
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162#endif
163
164#ifndef MODULE
165
166#ifndef __ASSEMBLY__
167
168/* initcalls are now grouped by functionality into separate
169 * subsections. Ordering inside the subsections is determined
170 * by link order.
171 * For backwards compatibility, initcall() puts the call in
172 * the device init subsection.
Andrew Morton735a7ff2006-10-27 11:42:37 -0700173 *
174 * The `id' arg to __define_initcall() is needed so that multiple initcalls
175 * can point at the same handler without causing duplicate-symbol build errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 */
177
Andrew Morton735a7ff2006-10-27 11:42:37 -0700178#define __define_initcall(level,fn,id) \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100179 static initcall_t __initcall_##fn##id __used \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 __attribute__((__section__(".initcall" level ".init"))) = fn
181
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800182/*
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700183 * Early initcalls run before initializing SMP.
184 *
185 * Only for built-in code, not modules.
186 */
187#define early_initcall(fn) __define_initcall("early",fn,early)
188
189/*
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800190 * A "pure" initcall has no dependencies on anything else, and purely
191 * initializes variables that couldn't be statically initialized.
192 *
193 * This only exists for built-in code, not for modules.
194 */
Michael Buesch73dd1162007-07-31 00:38:54 -0700195#define pure_initcall(fn) __define_initcall("0",fn,0)
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800196
Andrew Morton735a7ff2006-10-27 11:42:37 -0700197#define core_initcall(fn) __define_initcall("1",fn,1)
198#define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
199#define postcore_initcall(fn) __define_initcall("2",fn,2)
200#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
201#define arch_initcall(fn) __define_initcall("3",fn,3)
202#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
203#define subsys_initcall(fn) __define_initcall("4",fn,4)
204#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
205#define fs_initcall(fn) __define_initcall("5",fn,5)
206#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
Linus Torvalds8d610dd2006-12-11 12:12:04 -0800207#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
Andrew Morton735a7ff2006-10-27 11:42:37 -0700208#define device_initcall(fn) __define_initcall("6",fn,6)
209#define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
210#define late_initcall(fn) __define_initcall("7",fn,7)
211#define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
213#define __initcall(fn) device_initcall(fn)
214
215#define __exitcall(fn) \
216 static exitcall_t __exitcall_##fn __exit_call = fn
217
218#define console_initcall(fn) \
219 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100220 __used __section(.con_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222#define security_initcall(fn) \
223 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100224 __used __section(.security_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
226struct obs_kernel_param {
227 const char *str;
228 int (*setup_func)(char *);
229 int early;
230};
231
232/*
233 * Only for really core code. See moduleparam.h for the normal way.
234 *
235 * Force the alignment so the compiler doesn't space elements of the
236 * obs_kernel_param "array" too far apart in .init.setup.
237 */
238#define __setup_param(str, unique_id, fn, early) \
Jan Beulichfd6c3a82009-03-12 10:58:33 +0000239 static const char __setup_str_##unique_id[] __initconst \
240 __aligned(1) = str; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 static struct obs_kernel_param __setup_##unique_id \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100242 __used __section(.init.setup) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 __attribute__((aligned((sizeof(long))))) \
244 = { __setup_str_##unique_id, fn, early }
245
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246#define __setup(str, fn) \
247 __setup_param(str, fn, fn, 0)
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
250 * returns non-zero. */
251#define early_param(str, fn) \
252 __setup_param(str, fn, fn, 1)
253
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800254/* Relies on boot_command_line being set */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255void __init parse_early_param(void);
Magnus Damm13977092009-03-30 14:37:25 -0700256void __init parse_early_options(char *cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257#endif /* __ASSEMBLY__ */
258
259/**
260 * module_init() - driver initialization entry point
261 * @x: function to be run at kernel boot time or module insertion
262 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800263 * module_init() will either be called during do_initcalls() (if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 * builtin) or at module insertion time (if a module). There can only
265 * be one per module.
266 */
267#define module_init(x) __initcall(x);
268
269/**
270 * module_exit() - driver exit entry point
271 * @x: function to be run when driver is removed
272 *
273 * module_exit() will wrap the driver clean-up code
274 * with cleanup_module() when used with rmmod when
275 * the driver is a module. If the driver is statically
276 * compiled into the kernel, module_exit() has no effect.
277 * There can only be one per module.
278 */
279#define module_exit(x) __exitcall(x);
280
281#else /* MODULE */
282
283/* Don't use these in modules, but some people do... */
Borislav Petkov329bd412009-10-02 15:23:21 +0200284#define early_initcall(fn) module_init(fn)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285#define core_initcall(fn) module_init(fn)
286#define postcore_initcall(fn) module_init(fn)
287#define arch_initcall(fn) module_init(fn)
288#define subsys_initcall(fn) module_init(fn)
289#define fs_initcall(fn) module_init(fn)
290#define device_initcall(fn) module_init(fn)
291#define late_initcall(fn) module_init(fn)
292
293#define security_initcall(fn) module_init(fn)
294
Robert P. J. Day4500d062008-07-25 01:45:49 -0700295/* Each module must use one module_init(). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296#define module_init(initfn) \
297 static inline initcall_t __inittest(void) \
298 { return initfn; } \
299 int init_module(void) __attribute__((alias(#initfn)));
300
301/* This is only required if you want to be unloadable. */
302#define module_exit(exitfn) \
303 static inline exitcall_t __exittest(void) \
304 { return exitfn; } \
305 void cleanup_module(void) __attribute__((alias(#exitfn)));
306
307#define __setup_param(str, unique_id, fn) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308#define __setup(str, func) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309#endif
310
Johannes Bergab3bfca2007-05-06 14:50:49 -0700311/* Data marked not to be saved by software suspend */
Denys Vlasenko07b3bb12010-02-20 01:03:52 +0100312#define __nosavedata __section(.data..nosave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313
314/* This means "can be init if no module support, otherwise module load
315 may call it." */
316#ifdef CONFIG_MODULES
317#define __init_or_module
318#define __initdata_or_module
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100319#define __initconst_or_module
320#define __INIT_OR_MODULE .text
321#define __INITDATA_OR_MODULE .data
322#define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323#else
324#define __init_or_module __init
325#define __initdata_or_module __initdata
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100326#define __initconst_or_module __initconst
327#define __INIT_OR_MODULE __INIT
328#define __INITDATA_OR_MODULE __INITDATA
329#define __INITRODATA_OR_MODULE __INITRODATA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330#endif /*CONFIG_MODULES*/
331
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332/* Functions marked as __devexit may be discarded at kernel link time, depending
333 on config options. Newer versions of binutils detect references from
334 retained sections to discarded sections and flag an error. Pointers to
335 __devexit functions must use __devexit_p(function_name), the wrapper will
336 insert either the function_name or NULL, depending on the config options.
337 */
338#if defined(MODULE) || defined(CONFIG_HOTPLUG)
339#define __devexit_p(x) x
340#else
341#define __devexit_p(x) NULL
342#endif
343
344#ifdef MODULE
345#define __exit_p(x) x
346#else
347#define __exit_p(x) NULL
348#endif
349
350#endif /* _LINUX_INIT_H */