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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)
Andi Kleen754b7b62012-10-04 17:11:27 -070046#define __initconst __constsection(.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/*
Andi Kleen754b7b62012-10-04 17:11:27 -070051 * Some architecture have tool chains which do not handle rodata attributes
52 * correctly. For those disable special sections for const, so that other
53 * architectures can annotate correctly.
54 */
55#ifdef CONFIG_BROKEN_RODATA
56#define __constsection(x)
57#else
58#define __constsection(x) __section(x)
59#endif
60
61/*
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020062 * modpost check for section mismatches during the kernel build.
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020063 * A section mismatch happens when there are references from a
64 * code or data section to an init section (both code or data).
65 * The init sections are (for most archs) discarded by the kernel
66 * when early init has completed so all such references are potential bugs.
67 * For exit sections the same issue exists.
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020068 *
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020069 * The following markers are used for the cases where the reference to
Sam Ravnborg312b1482008-01-28 20:21:15 +010070 * the *init / *exit section (code or data) is valid and will teach
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020071 * modpost not to issue a warning. Intended semantics is that a code or
72 * data tagged __ref* can reference code or data from init section without
73 * producing a warning (of course, no warning does not mean code is
74 * correct, so optimally document why the __ref is needed and why it's OK).
75 *
76 * The markers follow same syntax rules as __init / __initdata.
77 */
Sam Ravnborg312b1482008-01-28 20:21:15 +010078#define __ref __section(.ref.text) noinline
79#define __refdata __section(.ref.data)
Andi Kleen754b7b62012-10-04 17:11:27 -070080#define __refconst __constsection(.ref.rodata)
Sam Ravnborg312b1482008-01-28 20:21:15 +010081
Sam Ravnborg312b1482008-01-28 20:21:15 +010082/* compatibility defines */
83#define __init_refok __ref
84#define __initdata_refok __refdata
85#define __exit_refok __ref
86
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020087
Linus Torvalds1da177e2005-04-16 15:20:36 -070088#ifdef MODULE
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010089#define __exitused
Linus Torvalds1da177e2005-04-16 15:20:36 -070090#else
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010091#define __exitused __used
Linus Torvalds1da177e2005-04-16 15:20:36 -070092#endif
93
Steven Rostedtf0201732011-04-12 19:06:39 -040094#define __exit __section(.exit.text) __exitused __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010095
Greg Kroah-Hartman78d86c22012-11-29 10:43:28 -080096/* Used for HOTPLUG, but that is always enabled now, so just make them noops */
97#define __devinit
98#define __devinitdata
99#define __devinitconst
100#define __devexit
101#define __devexitdata
102#define __devexitconst
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100103
104/* Used for HOTPLUG_CPU */
Steven Rostedtf0201732011-04-12 19:06:39 -0400105#define __cpuinit __section(.cpuinit.text) __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100106#define __cpuinitdata __section(.cpuinit.data)
Andi Kleen754b7b62012-10-04 17:11:27 -0700107#define __cpuinitconst __constsection(.cpuinit.rodata)
Steven Rostedtf0201732011-04-12 19:06:39 -0400108#define __cpuexit __section(.cpuexit.text) __exitused __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100109#define __cpuexitdata __section(.cpuexit.data)
Andi Kleen754b7b62012-10-04 17:11:27 -0700110#define __cpuexitconst __constsection(.cpuexit.rodata)
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100111
112/* Used for MEMORY_HOTPLUG */
Steven Rostedtf0201732011-04-12 19:06:39 -0400113#define __meminit __section(.meminit.text) __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100114#define __meminitdata __section(.meminit.data)
Andi Kleen754b7b62012-10-04 17:11:27 -0700115#define __meminitconst __constsection(.meminit.rodata)
Steven Rostedtf0201732011-04-12 19:06:39 -0400116#define __memexit __section(.memexit.text) __exitused __cold notrace
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100117#define __memexitdata __section(.memexit.data)
Andi Kleen754b7b62012-10-04 17:11:27 -0700118#define __memexitconst __constsection(.memexit.rodata)
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100119
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120/* For assembly routines */
Sam Ravnborg7923f902009-06-14 22:10:41 +0200121#define __HEAD .section ".head.text","ax"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122#define __INIT .section ".init.text","ax"
Prarit Bhargava86c0baf2007-05-02 19:27:05 +0200123#define __FINIT .previous
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100124
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100125#define __INITDATA .section ".init.data","aw",%progbits
126#define __INITRODATA .section ".init.rodata","a",%progbits
Ingo Molnar9f9975a2008-02-06 22:39:45 +0100127#define __FINITDATA .previous
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100129#define __CPUINIT .section ".cpuinit.text", "ax"
130#define __CPUINITDATA .section ".cpuinit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700131#define __CPUINITRODATA .section ".cpuinit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100132
133#define __MEMINIT .section ".meminit.text", "ax"
134#define __MEMINITDATA .section ".meminit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700135#define __MEMINITRODATA .section ".meminit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100136
Sam Ravnborg312b1482008-01-28 20:21:15 +0100137/* silence warnings when references are OK */
138#define __REF .section ".ref.text", "ax"
139#define __REFDATA .section ".ref.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700140#define __REFCONST .section ".ref.rodata", "a"
Sam Ravnborg312b1482008-01-28 20:21:15 +0100141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142#ifndef __ASSEMBLY__
143/*
144 * Used for initialization calls..
145 */
146typedef int (*initcall_t)(void);
147typedef void (*exitcall_t)(void);
148
149extern initcall_t __con_initcall_start[], __con_initcall_end[];
150extern initcall_t __security_initcall_start[], __security_initcall_end[];
151
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700152/* Used for contructor calls. */
153typedef void (*ctor_fn_t)(void);
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155/* Defined in init/main.c */
Arjan van de Ven59f94152008-07-30 12:49:02 -0700156extern int do_one_initcall(initcall_t fn);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800157extern char __initdata boot_command_line[];
158extern char *saved_command_line;
Vivek Goyal7e962872006-09-27 01:50:44 -0700159extern unsigned int reset_devices;
Adrian Bunk77d47582006-03-25 03:07:39 -0800160
161/* used by init/main.c */
Adrian Bunk46595392007-05-08 00:24:47 -0700162void setup_arch(char **);
163void prepare_namespace(void);
Adrian Bunk77d47582006-03-25 03:07:39 -0800164
Adrian Bunk7d195a52008-04-29 00:59:18 -0700165extern void (*late_time_init)(void);
166
Rusty Russell2329abf2012-01-13 09:32:18 +1030167extern bool initcall_debug;
Arjan van de Venf2511772009-12-13 20:29:01 +0100168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169#endif
170
171#ifndef MODULE
172
173#ifndef __ASSEMBLY__
174
175/* initcalls are now grouped by functionality into separate
176 * subsections. Ordering inside the subsections is determined
177 * by link order.
178 * For backwards compatibility, initcall() puts the call in
179 * the device init subsection.
Andrew Morton735a7ff2006-10-27 11:42:37 -0700180 *
181 * The `id' arg to __define_initcall() is needed so that multiple initcalls
182 * can point at the same handler without causing duplicate-symbol build errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 */
184
Matthew Leach7929d402012-12-17 15:59:32 -0800185#define __define_initcall(fn, id) \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100186 static initcall_t __initcall_##fn##id __used \
Matthew Leach7929d402012-12-17 15:59:32 -0800187 __attribute__((__section__(".initcall" #id ".init"))) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800189/*
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700190 * Early initcalls run before initializing SMP.
191 *
192 * Only for built-in code, not modules.
193 */
Matthew Leach7929d402012-12-17 15:59:32 -0800194#define early_initcall(fn) __define_initcall(fn, early)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700195
196/*
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800197 * A "pure" initcall has no dependencies on anything else, and purely
198 * initializes variables that couldn't be statically initialized.
199 *
200 * This only exists for built-in code, not for modules.
Jim Cromie96263d22012-06-14 16:00:59 -0600201 * Keep main.c:initcall_level_names[] in sync.
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800202 */
Matthew Leach7929d402012-12-17 15:59:32 -0800203#define pure_initcall(fn) __define_initcall(fn, 0)
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800204
Matthew Leach7929d402012-12-17 15:59:32 -0800205#define core_initcall(fn) __define_initcall(fn, 1)
206#define core_initcall_sync(fn) __define_initcall(fn, 1s)
207#define postcore_initcall(fn) __define_initcall(fn, 2)
208#define postcore_initcall_sync(fn) __define_initcall(fn, 2s)
209#define arch_initcall(fn) __define_initcall(fn, 3)
210#define arch_initcall_sync(fn) __define_initcall(fn, 3s)
211#define subsys_initcall(fn) __define_initcall(fn, 4)
212#define subsys_initcall_sync(fn) __define_initcall(fn, 4s)
213#define fs_initcall(fn) __define_initcall(fn, 5)
214#define fs_initcall_sync(fn) __define_initcall(fn, 5s)
215#define rootfs_initcall(fn) __define_initcall(fn, rootfs)
216#define device_initcall(fn) __define_initcall(fn, 6)
217#define device_initcall_sync(fn) __define_initcall(fn, 6s)
218#define late_initcall(fn) __define_initcall(fn, 7)
219#define late_initcall_sync(fn) __define_initcall(fn, 7s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221#define __initcall(fn) device_initcall(fn)
222
223#define __exitcall(fn) \
224 static exitcall_t __exitcall_##fn __exit_call = fn
225
226#define console_initcall(fn) \
227 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100228 __used __section(.con_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230#define security_initcall(fn) \
231 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100232 __used __section(.security_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
234struct obs_kernel_param {
235 const char *str;
236 int (*setup_func)(char *);
237 int early;
238};
239
240/*
241 * Only for really core code. See moduleparam.h for the normal way.
242 *
243 * Force the alignment so the compiler doesn't space elements of the
244 * obs_kernel_param "array" too far apart in .init.setup.
245 */
246#define __setup_param(str, unique_id, fn, early) \
Jan Beulichfd6c3a82009-03-12 10:58:33 +0000247 static const char __setup_str_##unique_id[] __initconst \
248 __aligned(1) = str; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 static struct obs_kernel_param __setup_##unique_id \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100250 __used __section(.init.setup) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 __attribute__((aligned((sizeof(long))))) \
252 = { __setup_str_##unique_id, fn, early }
253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254#define __setup(str, fn) \
255 __setup_param(str, fn, fn, 0)
256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
258 * returns non-zero. */
259#define early_param(str, fn) \
260 __setup_param(str, fn, fn, 1)
261
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800262/* Relies on boot_command_line being set */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263void __init parse_early_param(void);
Magnus Damm13977092009-03-30 14:37:25 -0700264void __init parse_early_options(char *cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265#endif /* __ASSEMBLY__ */
266
267/**
268 * module_init() - driver initialization entry point
269 * @x: function to be run at kernel boot time or module insertion
270 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800271 * module_init() will either be called during do_initcalls() (if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 * builtin) or at module insertion time (if a module). There can only
273 * be one per module.
274 */
275#define module_init(x) __initcall(x);
276
277/**
278 * module_exit() - driver exit entry point
279 * @x: function to be run when driver is removed
280 *
281 * module_exit() will wrap the driver clean-up code
282 * with cleanup_module() when used with rmmod when
283 * the driver is a module. If the driver is statically
284 * compiled into the kernel, module_exit() has no effect.
285 * There can only be one per module.
286 */
287#define module_exit(x) __exitcall(x);
288
289#else /* MODULE */
290
Jim Cromie96263d22012-06-14 16:00:59 -0600291/* Don't use these in loadable modules, but some people do... */
Borislav Petkov329bd412009-10-02 15:23:21 +0200292#define early_initcall(fn) module_init(fn)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293#define core_initcall(fn) module_init(fn)
294#define postcore_initcall(fn) module_init(fn)
295#define arch_initcall(fn) module_init(fn)
296#define subsys_initcall(fn) module_init(fn)
297#define fs_initcall(fn) module_init(fn)
298#define device_initcall(fn) module_init(fn)
299#define late_initcall(fn) module_init(fn)
300
301#define security_initcall(fn) module_init(fn)
302
Robert P. J. Day4500d062008-07-25 01:45:49 -0700303/* Each module must use one module_init(). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304#define module_init(initfn) \
305 static inline initcall_t __inittest(void) \
306 { return initfn; } \
307 int init_module(void) __attribute__((alias(#initfn)));
308
309/* This is only required if you want to be unloadable. */
310#define module_exit(exitfn) \
311 static inline exitcall_t __exittest(void) \
312 { return exitfn; } \
313 void cleanup_module(void) __attribute__((alias(#exitfn)));
314
315#define __setup_param(str, unique_id, fn) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316#define __setup(str, func) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317#endif
318
Johannes Bergab3bfca2007-05-06 14:50:49 -0700319/* Data marked not to be saved by software suspend */
Denys Vlasenko07b3bb12010-02-20 01:03:52 +0100320#define __nosavedata __section(.data..nosave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321
322/* This means "can be init if no module support, otherwise module load
323 may call it." */
324#ifdef CONFIG_MODULES
325#define __init_or_module
326#define __initdata_or_module
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100327#define __initconst_or_module
328#define __INIT_OR_MODULE .text
329#define __INITDATA_OR_MODULE .data
330#define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331#else
332#define __init_or_module __init
333#define __initdata_or_module __initdata
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100334#define __initconst_or_module __initconst
335#define __INIT_OR_MODULE __INIT
336#define __INITDATA_OR_MODULE __INITDATA
337#define __INITRODATA_OR_MODULE __INITRODATA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338#endif /*CONFIG_MODULES*/
339
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340/* Functions marked as __devexit may be discarded at kernel link time, depending
341 on config options. Newer versions of binutils detect references from
342 retained sections to discarded sections and flag an error. Pointers to
343 __devexit functions must use __devexit_p(function_name), the wrapper will
344 insert either the function_name or NULL, depending on the config options.
345 */
346#if defined(MODULE) || defined(CONFIG_HOTPLUG)
347#define __devexit_p(x) x
348#else
349#define __devexit_p(x) NULL
350#endif
351
352#ifdef MODULE
353#define __exit_p(x) x
354#else
355#define __exit_p(x) NULL
356#endif
357
358#endif /* _LINUX_INIT_H */