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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
48#ifdef MODULE
49#define __exit __attribute__ ((__section__(".exit.text")))
50#else
51#define __exit __attribute_used__ __attribute__ ((__section__(".exit.text")))
52#endif
53
54/* For assembly routines */
55#define __INIT .section ".init.text","ax"
56#define __FINIT .previous
57#define __INITDATA .section ".init.data","aw"
58
59#ifndef __ASSEMBLY__
60/*
61 * Used for initialization calls..
62 */
63typedef int (*initcall_t)(void);
64typedef void (*exitcall_t)(void);
65
66extern initcall_t __con_initcall_start[], __con_initcall_end[];
67extern initcall_t __security_initcall_start[], __security_initcall_end[];
68
69/* Defined in init/main.c */
70extern char saved_command_line[];
Adrian Bunk77d47582006-03-25 03:07:39 -080071
72/* used by init/main.c */
73extern void setup_arch(char **);
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075#endif
76
77#ifndef MODULE
78
79#ifndef __ASSEMBLY__
80
81/* initcalls are now grouped by functionality into separate
82 * subsections. Ordering inside the subsections is determined
83 * by link order.
84 * For backwards compatibility, initcall() puts the call in
85 * the device init subsection.
86 */
87
88#define __define_initcall(level,fn) \
89 static initcall_t __initcall_##fn __attribute_used__ \
90 __attribute__((__section__(".initcall" level ".init"))) = fn
91
92#define core_initcall(fn) __define_initcall("1",fn)
93#define postcore_initcall(fn) __define_initcall("2",fn)
94#define arch_initcall(fn) __define_initcall("3",fn)
95#define subsys_initcall(fn) __define_initcall("4",fn)
96#define fs_initcall(fn) __define_initcall("5",fn)
97#define device_initcall(fn) __define_initcall("6",fn)
98#define late_initcall(fn) __define_initcall("7",fn)
99
100#define __initcall(fn) device_initcall(fn)
101
102#define __exitcall(fn) \
103 static exitcall_t __exitcall_##fn __exit_call = fn
104
105#define console_initcall(fn) \
106 static initcall_t __initcall_##fn \
107 __attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn
108
109#define security_initcall(fn) \
110 static initcall_t __initcall_##fn \
111 __attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn
112
113struct obs_kernel_param {
114 const char *str;
115 int (*setup_func)(char *);
116 int early;
117};
118
119/*
120 * Only for really core code. See moduleparam.h for the normal way.
121 *
122 * Force the alignment so the compiler doesn't space elements of the
123 * obs_kernel_param "array" too far apart in .init.setup.
124 */
125#define __setup_param(str, unique_id, fn, early) \
126 static char __setup_str_##unique_id[] __initdata = str; \
127 static struct obs_kernel_param __setup_##unique_id \
128 __attribute_used__ \
129 __attribute__((__section__(".init.setup"))) \
130 __attribute__((aligned((sizeof(long))))) \
131 = { __setup_str_##unique_id, fn, early }
132
133#define __setup_null_param(str, unique_id) \
134 __setup_param(str, unique_id, NULL, 0)
135
136#define __setup(str, fn) \
137 __setup_param(str, fn, fn, 0)
138
139#define __obsolete_setup(str) \
140 __setup_null_param(str, __LINE__)
141
142/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
143 * returns non-zero. */
144#define early_param(str, fn) \
145 __setup_param(str, fn, fn, 1)
146
147/* Relies on saved_command_line being set */
148void __init parse_early_param(void);
149#endif /* __ASSEMBLY__ */
150
151/**
152 * module_init() - driver initialization entry point
153 * @x: function to be run at kernel boot time or module insertion
154 *
155 * module_init() will either be called during do_initcalls (if
156 * builtin) or at module insertion time (if a module). There can only
157 * be one per module.
158 */
159#define module_init(x) __initcall(x);
160
161/**
162 * module_exit() - driver exit entry point
163 * @x: function to be run when driver is removed
164 *
165 * module_exit() will wrap the driver clean-up code
166 * with cleanup_module() when used with rmmod when
167 * the driver is a module. If the driver is statically
168 * compiled into the kernel, module_exit() has no effect.
169 * There can only be one per module.
170 */
171#define module_exit(x) __exitcall(x);
172
173#else /* MODULE */
174
175/* Don't use these in modules, but some people do... */
176#define core_initcall(fn) module_init(fn)
177#define postcore_initcall(fn) module_init(fn)
178#define arch_initcall(fn) module_init(fn)
179#define subsys_initcall(fn) module_init(fn)
180#define fs_initcall(fn) module_init(fn)
181#define device_initcall(fn) module_init(fn)
182#define late_initcall(fn) module_init(fn)
183
184#define security_initcall(fn) module_init(fn)
185
186/* These macros create a dummy inline: gcc 2.9x does not count alias
187 as usage, hence the `unused function' warning when __init functions
188 are declared static. We use the dummy __*_module_inline functions
189 both to kill the warning and check the type of the init/cleanup
190 function. */
191
192/* Each module must use one module_init(), or one no_module_init */
193#define module_init(initfn) \
194 static inline initcall_t __inittest(void) \
195 { return initfn; } \
196 int init_module(void) __attribute__((alias(#initfn)));
197
198/* This is only required if you want to be unloadable. */
199#define module_exit(exitfn) \
200 static inline exitcall_t __exittest(void) \
201 { return exitfn; } \
202 void cleanup_module(void) __attribute__((alias(#exitfn)));
203
204#define __setup_param(str, unique_id, fn) /* nothing */
205#define __setup_null_param(str, unique_id) /* nothing */
206#define __setup(str, func) /* nothing */
207#define __obsolete_setup(str) /* nothing */
208#endif
209
210/* Data marked not to be saved by software_suspend() */
211#define __nosavedata __attribute__ ((__section__ (".data.nosave")))
212
213/* This means "can be init if no module support, otherwise module load
214 may call it." */
215#ifdef CONFIG_MODULES
216#define __init_or_module
217#define __initdata_or_module
218#else
219#define __init_or_module __init
220#define __initdata_or_module __initdata
221#endif /*CONFIG_MODULES*/
222
223#ifdef CONFIG_HOTPLUG
224#define __devinit
225#define __devinitdata
226#define __devexit
227#define __devexitdata
228#else
229#define __devinit __init
230#define __devinitdata __initdata
231#define __devexit __exit
232#define __devexitdata __exitdata
233#endif
234
Ashok Raje6982c62005-06-25 14:54:58 -0700235#ifdef CONFIG_HOTPLUG_CPU
236#define __cpuinit
237#define __cpuinitdata
238#define __cpuexit
239#define __cpuexitdata
240#else
241#define __cpuinit __init
242#define __cpuinitdata __initdata
243#define __cpuexit __exit
244#define __cpuexitdata __exitdata
245#endif
246
Andi Kleen9d99aaa2006-04-07 19:49:15 +0200247#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_ACPI_HOTPLUG_MEMORY) \
248 || defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)
Matt Tolentinoc09b4242006-01-17 07:03:44 +0100249#define __meminit
250#define __meminitdata
251#define __memexit
252#define __memexitdata
253#else
254#define __meminit __init
255#define __meminitdata __initdata
256#define __memexit __exit
257#define __memexitdata __exitdata
258#endif
259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260/* Functions marked as __devexit may be discarded at kernel link time, depending
261 on config options. Newer versions of binutils detect references from
262 retained sections to discarded sections and flag an error. Pointers to
263 __devexit functions must use __devexit_p(function_name), the wrapper will
264 insert either the function_name or NULL, depending on the config options.
265 */
266#if defined(MODULE) || defined(CONFIG_HOTPLUG)
267#define __devexit_p(x) x
268#else
269#define __devexit_p(x) NULL
270#endif
271
272#ifdef MODULE
273#define __exit_p(x) x
274#else
275#define __exit_p(x) NULL
276#endif
277
278#endif /* _LINUX_INIT_H */