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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) */
43#define __init __attribute__ ((__section__ (".init.text")))
44#define __initdata __attribute__ ((__section__ (".init.data")))
45#define __exitdata __attribute__ ((__section__(".exit.data")))
46#define __exit_call __attribute_used__ __attribute__ ((__section__ (".exitcall.exit")))
47
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020048/* modpost check for section mismatches during the kernel build.
49 * A section mismatch happens when there are references from a
50 * code or data section to an init section (both code or data).
51 * The init sections are (for most archs) discarded by the kernel
52 * when early init has completed so all such references are potential bugs.
53 * For exit sections the same issue exists.
54 * The following markers are used for the cases where the reference to
55 * the init/exit section (code or data) is valid and will teach modpost
56 * not to issue a warning.
57 * The markers follow same syntax rules as __init / __initdata. */
58#define __init_refok noinline __attribute__ ((__section__ (".text.init.refok")))
59#define __initdata_refok __attribute__ ((__section__ (".data.init.refok")))
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#ifdef MODULE
62#define __exit __attribute__ ((__section__(".exit.text")))
63#else
64#define __exit __attribute_used__ __attribute__ ((__section__(".exit.text")))
65#endif
66
67/* For assembly routines */
68#define __INIT .section ".init.text","ax"
Prarit Bhargava86c0baf2007-05-02 19:27:05 +020069#define __FINIT .previous
Prarit Bhargava838c4112007-05-15 01:41:43 -070070#define __INITDATA .section ".init.data","aw"
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72#ifndef __ASSEMBLY__
73/*
74 * Used for initialization calls..
75 */
76typedef int (*initcall_t)(void);
77typedef void (*exitcall_t)(void);
78
79extern initcall_t __con_initcall_start[], __con_initcall_end[];
80extern initcall_t __security_initcall_start[], __security_initcall_end[];
81
82/* Defined in init/main.c */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -080083extern char __initdata boot_command_line[];
84extern char *saved_command_line;
Vivek Goyal7e962872006-09-27 01:50:44 -070085extern unsigned int reset_devices;
Adrian Bunk77d47582006-03-25 03:07:39 -080086
87/* used by init/main.c */
Adrian Bunk46595392007-05-08 00:24:47 -070088void setup_arch(char **);
89void prepare_namespace(void);
Adrian Bunk77d47582006-03-25 03:07:39 -080090
Linus Torvalds1da177e2005-04-16 15:20:36 -070091#endif
92
93#ifndef MODULE
94
95#ifndef __ASSEMBLY__
96
97/* initcalls are now grouped by functionality into separate
98 * subsections. Ordering inside the subsections is determined
99 * by link order.
100 * For backwards compatibility, initcall() puts the call in
101 * the device init subsection.
Andrew Morton735a7ff2006-10-27 11:42:37 -0700102 *
103 * The `id' arg to __define_initcall() is needed so that multiple initcalls
104 * can point at the same handler without causing duplicate-symbol build errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 */
106
Andrew Morton735a7ff2006-10-27 11:42:37 -0700107#define __define_initcall(level,fn,id) \
108 static initcall_t __initcall_##fn##id __attribute_used__ \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 __attribute__((__section__(".initcall" level ".init"))) = fn
110
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800111/*
112 * A "pure" initcall has no dependencies on anything else, and purely
113 * initializes variables that couldn't be statically initialized.
114 *
115 * This only exists for built-in code, not for modules.
116 */
117#define pure_initcall(fn) __define_initcall("0",fn,1)
118
Andrew Morton735a7ff2006-10-27 11:42:37 -0700119#define core_initcall(fn) __define_initcall("1",fn,1)
120#define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
121#define postcore_initcall(fn) __define_initcall("2",fn,2)
122#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
123#define arch_initcall(fn) __define_initcall("3",fn,3)
124#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
125#define subsys_initcall(fn) __define_initcall("4",fn,4)
126#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
127#define fs_initcall(fn) __define_initcall("5",fn,5)
128#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
Linus Torvalds8d610dd2006-12-11 12:12:04 -0800129#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
Andrew Morton735a7ff2006-10-27 11:42:37 -0700130#define device_initcall(fn) __define_initcall("6",fn,6)
131#define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
132#define late_initcall(fn) __define_initcall("7",fn,7)
133#define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135#define __initcall(fn) device_initcall(fn)
136
137#define __exitcall(fn) \
138 static exitcall_t __exitcall_##fn __exit_call = fn
139
140#define console_initcall(fn) \
141 static initcall_t __initcall_##fn \
142 __attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn
143
144#define security_initcall(fn) \
145 static initcall_t __initcall_##fn \
146 __attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn
147
148struct obs_kernel_param {
149 const char *str;
150 int (*setup_func)(char *);
151 int early;
152};
153
154/*
155 * Only for really core code. See moduleparam.h for the normal way.
156 *
157 * Force the alignment so the compiler doesn't space elements of the
158 * obs_kernel_param "array" too far apart in .init.setup.
159 */
160#define __setup_param(str, unique_id, fn, early) \
161 static char __setup_str_##unique_id[] __initdata = str; \
162 static struct obs_kernel_param __setup_##unique_id \
163 __attribute_used__ \
164 __attribute__((__section__(".init.setup"))) \
165 __attribute__((aligned((sizeof(long))))) \
166 = { __setup_str_##unique_id, fn, early }
167
168#define __setup_null_param(str, unique_id) \
169 __setup_param(str, unique_id, NULL, 0)
170
171#define __setup(str, fn) \
172 __setup_param(str, fn, fn, 0)
173
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
175 * returns non-zero. */
176#define early_param(str, fn) \
177 __setup_param(str, fn, fn, 1)
178
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800179/* Relies on boot_command_line being set */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180void __init parse_early_param(void);
181#endif /* __ASSEMBLY__ */
182
183/**
184 * module_init() - driver initialization entry point
185 * @x: function to be run at kernel boot time or module insertion
186 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800187 * module_init() will either be called during do_initcalls() (if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 * builtin) or at module insertion time (if a module). There can only
189 * be one per module.
190 */
191#define module_init(x) __initcall(x);
192
193/**
194 * module_exit() - driver exit entry point
195 * @x: function to be run when driver is removed
196 *
197 * module_exit() will wrap the driver clean-up code
198 * with cleanup_module() when used with rmmod when
199 * the driver is a module. If the driver is statically
200 * compiled into the kernel, module_exit() has no effect.
201 * There can only be one per module.
202 */
203#define module_exit(x) __exitcall(x);
204
205#else /* MODULE */
206
207/* Don't use these in modules, but some people do... */
208#define core_initcall(fn) module_init(fn)
209#define postcore_initcall(fn) module_init(fn)
210#define arch_initcall(fn) module_init(fn)
211#define subsys_initcall(fn) module_init(fn)
212#define fs_initcall(fn) module_init(fn)
213#define device_initcall(fn) module_init(fn)
214#define late_initcall(fn) module_init(fn)
215
216#define security_initcall(fn) module_init(fn)
217
218/* These macros create a dummy inline: gcc 2.9x does not count alias
219 as usage, hence the `unused function' warning when __init functions
220 are declared static. We use the dummy __*_module_inline functions
221 both to kill the warning and check the type of the init/cleanup
222 function. */
223
224/* Each module must use one module_init(), or one no_module_init */
225#define module_init(initfn) \
226 static inline initcall_t __inittest(void) \
227 { return initfn; } \
228 int init_module(void) __attribute__((alias(#initfn)));
229
230/* This is only required if you want to be unloadable. */
231#define module_exit(exitfn) \
232 static inline exitcall_t __exittest(void) \
233 { return exitfn; } \
234 void cleanup_module(void) __attribute__((alias(#exitfn)));
235
236#define __setup_param(str, unique_id, fn) /* nothing */
237#define __setup_null_param(str, unique_id) /* nothing */
238#define __setup(str, func) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239#endif
240
Johannes Bergab3bfca2007-05-06 14:50:49 -0700241/* Data marked not to be saved by software suspend */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242#define __nosavedata __attribute__ ((__section__ (".data.nosave")))
243
244/* This means "can be init if no module support, otherwise module load
245 may call it." */
246#ifdef CONFIG_MODULES
247#define __init_or_module
248#define __initdata_or_module
249#else
250#define __init_or_module __init
251#define __initdata_or_module __initdata
252#endif /*CONFIG_MODULES*/
253
254#ifdef CONFIG_HOTPLUG
255#define __devinit
256#define __devinitdata
257#define __devexit
258#define __devexitdata
259#else
260#define __devinit __init
261#define __devinitdata __initdata
262#define __devexit __exit
263#define __devexitdata __exitdata
264#endif
265
Ashok Raje6982c62005-06-25 14:54:58 -0700266#ifdef CONFIG_HOTPLUG_CPU
267#define __cpuinit
268#define __cpuinitdata
269#define __cpuexit
270#define __cpuexitdata
271#else
272#define __cpuinit __init
273#define __cpuinitdata __initdata
274#define __cpuexit __exit
275#define __cpuexitdata __exitdata
276#endif
277
Andi Kleen9d99aaa2006-04-07 19:49:15 +0200278#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_ACPI_HOTPLUG_MEMORY) \
279 || defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)
Matt Tolentinoc09b4242006-01-17 07:03:44 +0100280#define __meminit
281#define __meminitdata
282#define __memexit
283#define __memexitdata
284#else
285#define __meminit __init
286#define __meminitdata __initdata
287#define __memexit __exit
288#define __memexitdata __exitdata
289#endif
290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291/* Functions marked as __devexit may be discarded at kernel link time, depending
292 on config options. Newer versions of binutils detect references from
293 retained sections to discarded sections and flag an error. Pointers to
294 __devexit functions must use __devexit_p(function_name), the wrapper will
295 insert either the function_name or NULL, depending on the config options.
296 */
297#if defined(MODULE) || defined(CONFIG_HOTPLUG)
298#define __devexit_p(x) x
299#else
300#define __devexit_p(x) NULL
301#endif
302
303#ifdef MODULE
304#define __exit_p(x) x
305#else
306#define __exit_p(x) NULL
307#endif
308
309#endif /* _LINUX_INIT_H */